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Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/inode.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Goal-directed block allocation by Stephen Tweedie
16 * (sct@redhat.com), 1993, 1998
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 * 64-bit file support on 64-bit platforms by Jakub Jelinek
20 * (jj@sunsite.ms.mff.cuni.cz)
21 *
Mingming Cao617ba132006-10-11 01:20:53 -070022 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
Dave Kleikampac27a0e2006-10-11 01:20:50 -070023 */
24
25#include <linux/module.h>
26#include <linux/fs.h>
27#include <linux/time.h>
Mingming Caodab291a2006-10-11 01:21:01 -070028#include <linux/jbd2.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070029#include <linux/highuid.h>
30#include <linux/pagemap.h>
31#include <linux/quotaops.h>
32#include <linux/string.h>
33#include <linux/buffer_head.h>
34#include <linux/writeback.h>
Alex Tomas64769242008-07-11 19:27:31 -040035#include <linux/pagevec.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070036#include <linux/mpage.h>
Duane Griffine83c1392008-12-19 20:47:15 +000037#include <linux/namei.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070038#include <linux/uio.h>
39#include <linux/bio.h>
Mingming Cao4c0425f2009-09-28 15:48:41 -040040#include <linux/workqueue.h>
Jiaying Zhang744692d2010-03-04 16:14:02 -050041#include <linux/kernel.h>
Andrew Morton6db26ff2011-01-12 16:59:13 -080042#include <linux/printk.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090043#include <linux/slab.h>
Theodore Ts'oa8901d32010-12-17 10:40:47 -050044#include <linux/ratelimit.h>
Theodore Ts'o9bffad12009-06-17 11:48:11 -040045
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040046#include "ext4_jbd2.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070047#include "xattr.h"
48#include "acl.h"
Mingming Caod2a17632008-07-14 17:52:37 -040049#include "ext4_extents.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070050
Theodore Ts'o9bffad12009-06-17 11:48:11 -040051#include <trace/events/ext4.h>
52
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -040053#define MPAGE_DA_EXTENT_TAIL 0x01
54
Jan Kara678aaf42008-07-11 19:27:31 -040055static inline int ext4_begin_ordered_truncate(struct inode *inode,
56 loff_t new_size)
57{
Theodore Ts'o7ff9c072010-11-08 13:51:33 -050058 trace_ext4_begin_ordered_truncate(inode, new_size);
Theodore Ts'o8aefcd52011-01-10 12:29:43 -050059 /*
60 * If jinode is zero, then we never opened the file for
61 * writing, so there's no need to call
62 * jbd2_journal_begin_ordered_truncate() since there's no
63 * outstanding writes we need to flush.
64 */
65 if (!EXT4_I(inode)->jinode)
66 return 0;
67 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
68 EXT4_I(inode)->jinode,
69 new_size);
Jan Kara678aaf42008-07-11 19:27:31 -040070}
71
Alex Tomas64769242008-07-11 19:27:31 -040072static void ext4_invalidatepage(struct page *page, unsigned long offset);
Theodore Ts'ocb20d512010-10-27 21:30:09 -040073static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
74 struct buffer_head *bh_result, int create);
75static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
76static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
77static int __ext4_journalled_writepage(struct page *page, unsigned int len);
78static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
Alex Tomas64769242008-07-11 19:27:31 -040079
Dave Kleikampac27a0e2006-10-11 01:20:50 -070080/*
81 * Test whether an inode is a fast symlink.
82 */
Mingming Cao617ba132006-10-11 01:20:53 -070083static int ext4_inode_is_fast_symlink(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070084{
Mingming Cao617ba132006-10-11 01:20:53 -070085 int ea_blocks = EXT4_I(inode)->i_file_acl ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -070086 (inode->i_sb->s_blocksize >> 9) : 0;
87
88 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
89}
90
91/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -070092 * Work out how many blocks we need to proceed with the next chunk of a
93 * truncate transaction.
94 */
95static unsigned long blocks_for_truncate(struct inode *inode)
96{
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -050097 ext4_lblk_t needed;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070098
99 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
100
101 /* Give ourselves just enough room to cope with inodes in which
102 * i_blocks is corrupt: we've seen disk corruptions in the past
103 * which resulted in random data in an inode which looked enough
Mingming Cao617ba132006-10-11 01:20:53 -0700104 * like a regular file for ext4 to try to delete it. Things
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700105 * will go a bit crazy if that happens, but at least we should
106 * try not to panic the whole kernel. */
107 if (needed < 2)
108 needed = 2;
109
110 /* But we need to bound the transaction so we don't overflow the
111 * journal. */
Mingming Cao617ba132006-10-11 01:20:53 -0700112 if (needed > EXT4_MAX_TRANS_DATA)
113 needed = EXT4_MAX_TRANS_DATA;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700114
Mingming Cao617ba132006-10-11 01:20:53 -0700115 return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700116}
117
118/*
119 * Truncate transactions can be complex and absolutely huge. So we need to
120 * be able to restart the transaction at a conventient checkpoint to make
121 * sure we don't overflow the journal.
122 *
123 * start_transaction gets us a new handle for a truncate transaction,
124 * and extend_transaction tries to extend the existing one a bit. If
125 * extend fails, we need to propagate the failure up and restart the
126 * transaction in the top-level truncate loop. --sct
127 */
128static handle_t *start_transaction(struct inode *inode)
129{
130 handle_t *result;
131
Mingming Cao617ba132006-10-11 01:20:53 -0700132 result = ext4_journal_start(inode, blocks_for_truncate(inode));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700133 if (!IS_ERR(result))
134 return result;
135
Mingming Cao617ba132006-10-11 01:20:53 -0700136 ext4_std_error(inode->i_sb, PTR_ERR(result));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700137 return result;
138}
139
140/*
141 * Try to extend this transaction for the purposes of truncation.
142 *
143 * Returns 0 if we managed to create more room. If we can't create more
144 * room, and the transaction must be restarted we return 1.
145 */
146static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
147{
Frank Mayhar03901312009-01-07 00:06:22 -0500148 if (!ext4_handle_valid(handle))
149 return 0;
150 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700151 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700152 if (!ext4_journal_extend(handle, blocks_for_truncate(inode)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700153 return 0;
154 return 1;
155}
156
157/*
158 * Restart the transaction associated with *handle. This does a commit,
159 * so before we call here everything must be consistently dirtied against
160 * this transaction.
161 */
Aneesh Kumar K.Vfa5d1112009-11-02 18:50:49 -0500162int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
Jan Kara487caee2009-08-17 22:17:20 -0400163 int nblocks)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700164{
Jan Kara487caee2009-08-17 22:17:20 -0400165 int ret;
166
167 /*
Theodore Ts'oe35fd662010-05-16 19:00:00 -0400168 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
Jan Kara487caee2009-08-17 22:17:20 -0400169 * moment, get_block can be called only for blocks inside i_size since
170 * page cache has been already dropped and writes are blocked by
171 * i_mutex. So we can safely drop the i_data_sem here.
172 */
Frank Mayhar03901312009-01-07 00:06:22 -0500173 BUG_ON(EXT4_JOURNAL(inode) == NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700174 jbd_debug(2, "restarting handle %p\n", handle);
Jan Kara487caee2009-08-17 22:17:20 -0400175 up_write(&EXT4_I(inode)->i_data_sem);
Amir Goldstein8e8eaab2011-02-27 23:32:12 -0500176 ret = ext4_journal_restart(handle, nblocks);
Jan Kara487caee2009-08-17 22:17:20 -0400177 down_write(&EXT4_I(inode)->i_data_sem);
Aneesh Kumar K.Vfa5d1112009-11-02 18:50:49 -0500178 ext4_discard_preallocations(inode);
Jan Kara487caee2009-08-17 22:17:20 -0400179
180 return ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700181}
182
183/*
184 * Called at the last iput() if i_nlink is zero.
185 */
Al Viro0930fcc2010-06-07 13:16:22 -0400186void ext4_evict_inode(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700187{
188 handle_t *handle;
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400189 int err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700190
Theodore Ts'o7ff9c072010-11-08 13:51:33 -0500191 trace_ext4_evict_inode(inode);
Al Viro0930fcc2010-06-07 13:16:22 -0400192 if (inode->i_nlink) {
193 truncate_inode_pages(&inode->i_data, 0);
194 goto no_delete;
195 }
196
Christoph Hellwig907f4552010-03-03 09:05:06 -0500197 if (!is_bad_inode(inode))
Christoph Hellwig871a2932010-03-03 09:05:07 -0500198 dquot_initialize(inode);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500199
Jan Kara678aaf42008-07-11 19:27:31 -0400200 if (ext4_should_order_data(inode))
201 ext4_begin_ordered_truncate(inode, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700202 truncate_inode_pages(&inode->i_data, 0);
203
204 if (is_bad_inode(inode))
205 goto no_delete;
206
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400207 handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700208 if (IS_ERR(handle)) {
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400209 ext4_std_error(inode->i_sb, PTR_ERR(handle));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700210 /*
211 * If we're going to skip the normal cleanup, we still need to
212 * make sure that the in-core orphan linked list is properly
213 * cleaned up.
214 */
Mingming Cao617ba132006-10-11 01:20:53 -0700215 ext4_orphan_del(NULL, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700216 goto no_delete;
217 }
218
219 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -0500220 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700221 inode->i_size = 0;
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400222 err = ext4_mark_inode_dirty(handle, inode);
223 if (err) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500224 ext4_warning(inode->i_sb,
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400225 "couldn't mark inode dirty (err %d)", err);
226 goto stop_handle;
227 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700228 if (inode->i_blocks)
Mingming Cao617ba132006-10-11 01:20:53 -0700229 ext4_truncate(inode);
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400230
231 /*
232 * ext4_ext_truncate() doesn't reserve any slop when it
233 * restarts journal transactions; therefore there may not be
234 * enough credits left in the handle to remove the inode from
235 * the orphan list and set the dtime field.
236 */
Frank Mayhar03901312009-01-07 00:06:22 -0500237 if (!ext4_handle_has_enough_credits(handle, 3)) {
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400238 err = ext4_journal_extend(handle, 3);
239 if (err > 0)
240 err = ext4_journal_restart(handle, 3);
241 if (err != 0) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500242 ext4_warning(inode->i_sb,
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400243 "couldn't extend journal (err %d)", err);
244 stop_handle:
245 ext4_journal_stop(handle);
Theodore Ts'o45388212010-07-29 15:06:10 -0400246 ext4_orphan_del(NULL, inode);
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400247 goto no_delete;
248 }
249 }
250
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700251 /*
Mingming Cao617ba132006-10-11 01:20:53 -0700252 * Kill off the orphan record which ext4_truncate created.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700253 * AKPM: I think this can be inside the above `if'.
Mingming Cao617ba132006-10-11 01:20:53 -0700254 * Note that ext4_orphan_del() has to be able to cope with the
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700255 * deletion of a non-existent orphan - this is because we don't
Mingming Cao617ba132006-10-11 01:20:53 -0700256 * know if ext4_truncate() actually created an orphan record.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700257 * (Well, we could do this if we need to, but heck - it works)
258 */
Mingming Cao617ba132006-10-11 01:20:53 -0700259 ext4_orphan_del(handle, inode);
260 EXT4_I(inode)->i_dtime = get_seconds();
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700261
262 /*
263 * One subtle ordering requirement: if anything has gone wrong
264 * (transaction abort, IO errors, whatever), then we can still
265 * do these next steps (the fs will already have been marked as
266 * having errors), but we can't free the inode if the mark_dirty
267 * fails.
268 */
Mingming Cao617ba132006-10-11 01:20:53 -0700269 if (ext4_mark_inode_dirty(handle, inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700270 /* If that failed, just do the required in-core inode clear. */
Al Viro0930fcc2010-06-07 13:16:22 -0400271 ext4_clear_inode(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700272 else
Mingming Cao617ba132006-10-11 01:20:53 -0700273 ext4_free_inode(handle, inode);
274 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700275 return;
276no_delete:
Al Viro0930fcc2010-06-07 13:16:22 -0400277 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700278}
279
280typedef struct {
281 __le32 *p;
282 __le32 key;
283 struct buffer_head *bh;
284} Indirect;
285
286static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
287{
288 p->key = *(p->p = v);
289 p->bh = bh;
290}
291
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700292/**
Mingming Cao617ba132006-10-11 01:20:53 -0700293 * ext4_block_to_path - parse the block number into array of offsets
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700294 * @inode: inode in question (we are only interested in its superblock)
295 * @i_block: block number to be parsed
296 * @offsets: array to store the offsets in
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400297 * @boundary: set this non-zero if the referred-to block is likely to be
298 * followed (on disk) by an indirect block.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700299 *
Mingming Cao617ba132006-10-11 01:20:53 -0700300 * To store the locations of file's data ext4 uses a data structure common
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700301 * for UNIX filesystems - tree of pointers anchored in the inode, with
302 * data blocks at leaves and indirect blocks in intermediate nodes.
303 * This function translates the block number into path in that tree -
304 * return value is the path length and @offsets[n] is the offset of
305 * pointer to (n+1)th node in the nth one. If @block is out of range
306 * (negative or too large) warning is printed and zero returned.
307 *
308 * Note: function doesn't find node addresses, so no IO is needed. All
309 * we need to know is the capacity of indirect blocks (taken from the
310 * inode->i_sb).
311 */
312
313/*
314 * Portability note: the last comparison (check that we fit into triple
315 * indirect block) is spelled differently, because otherwise on an
316 * architecture with 32-bit longs and 8Kb pages we might get into trouble
317 * if our filesystem had 8Kb blocks. We might use long long, but that would
318 * kill us on x86. Oh, well, at least the sign propagation does not matter -
319 * i_block would have to be negative in the very beginning, so we would not
320 * get there at all.
321 */
322
Mingming Cao617ba132006-10-11 01:20:53 -0700323static int ext4_block_to_path(struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400324 ext4_lblk_t i_block,
325 ext4_lblk_t offsets[4], int *boundary)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700326{
Mingming Cao617ba132006-10-11 01:20:53 -0700327 int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
328 int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
329 const long direct_blocks = EXT4_NDIR_BLOCKS,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700330 indirect_blocks = ptrs,
331 double_blocks = (1 << (ptrs_bits * 2));
332 int n = 0;
333 int final = 0;
334
Roel Kluinc333e072009-08-10 22:47:22 -0400335 if (i_block < direct_blocks) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700336 offsets[n++] = i_block;
337 final = direct_blocks;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400338 } else if ((i_block -= direct_blocks) < indirect_blocks) {
Mingming Cao617ba132006-10-11 01:20:53 -0700339 offsets[n++] = EXT4_IND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700340 offsets[n++] = i_block;
341 final = ptrs;
342 } else if ((i_block -= indirect_blocks) < double_blocks) {
Mingming Cao617ba132006-10-11 01:20:53 -0700343 offsets[n++] = EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700344 offsets[n++] = i_block >> ptrs_bits;
345 offsets[n++] = i_block & (ptrs - 1);
346 final = ptrs;
347 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
Mingming Cao617ba132006-10-11 01:20:53 -0700348 offsets[n++] = EXT4_TIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700349 offsets[n++] = i_block >> (ptrs_bits * 2);
350 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
351 offsets[n++] = i_block & (ptrs - 1);
352 final = ptrs;
353 } else {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500354 ext4_warning(inode->i_sb, "block %lu > max in inode %lu",
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400355 i_block + direct_blocks +
356 indirect_blocks + double_blocks, inode->i_ino);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700357 }
358 if (boundary)
359 *boundary = final - 1 - (i_block & (ptrs - 1));
360 return n;
361}
362
Theodore Ts'oc398eda2010-07-27 11:56:40 -0400363static int __ext4_check_blockref(const char *function, unsigned int line,
364 struct inode *inode,
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400365 __le32 *p, unsigned int max)
366{
Theodore Ts'o1c13d5c2010-07-27 11:56:03 -0400367 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
Thiemo Nagelf73953c2009-04-07 18:46:47 -0400368 __le32 *bref = p;
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400369 unsigned int blk;
370
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400371 while (bref < p+max) {
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400372 blk = le32_to_cpu(*bref++);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400373 if (blk &&
374 unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb),
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400375 blk, 1))) {
Theodore Ts'o1c13d5c2010-07-27 11:56:03 -0400376 es->s_last_error_block = cpu_to_le64(blk);
Theodore Ts'oc398eda2010-07-27 11:56:40 -0400377 ext4_error_inode(inode, function, line, blk,
378 "invalid block");
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400379 return -EIO;
380 }
381 }
382 return 0;
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400383}
384
385
386#define ext4_check_indirect_blockref(inode, bh) \
Theodore Ts'oc398eda2010-07-27 11:56:40 -0400387 __ext4_check_blockref(__func__, __LINE__, inode, \
388 (__le32 *)(bh)->b_data, \
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400389 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
390
391#define ext4_check_inode_blockref(inode) \
Theodore Ts'oc398eda2010-07-27 11:56:40 -0400392 __ext4_check_blockref(__func__, __LINE__, inode, \
393 EXT4_I(inode)->i_data, \
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400394 EXT4_NDIR_BLOCKS)
395
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700396/**
Mingming Cao617ba132006-10-11 01:20:53 -0700397 * ext4_get_branch - read the chain of indirect blocks leading to data
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700398 * @inode: inode in question
399 * @depth: depth of the chain (1 - direct pointer, etc.)
400 * @offsets: offsets of pointers in inode/indirect blocks
401 * @chain: place to store the result
402 * @err: here we store the error value
403 *
404 * Function fills the array of triples <key, p, bh> and returns %NULL
405 * if everything went OK or the pointer to the last filled triple
406 * (incomplete one) otherwise. Upon the return chain[i].key contains
407 * the number of (i+1)-th block in the chain (as it is stored in memory,
408 * i.e. little-endian 32-bit), chain[i].p contains the address of that
409 * number (it points into struct inode for i==0 and into the bh->b_data
410 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
411 * block for i>0 and NULL for i==0. In other words, it holds the block
412 * numbers of the chain, addresses they were taken from (and where we can
413 * verify that chain did not change) and buffer_heads hosting these
414 * numbers.
415 *
416 * Function stops when it stumbles upon zero pointer (absent block)
417 * (pointer to last triple returned, *@err == 0)
418 * or when it gets an IO error reading an indirect block
419 * (ditto, *@err == -EIO)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700420 * or when it reads all @depth-1 indirect blocks successfully and finds
421 * the whole chain, all way to the data (returns %NULL, *err == 0).
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500422 *
423 * Need to be called with
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -0500424 * down_read(&EXT4_I(inode)->i_data_sem)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700425 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500426static Indirect *ext4_get_branch(struct inode *inode, int depth,
427 ext4_lblk_t *offsets,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700428 Indirect chain[4], int *err)
429{
430 struct super_block *sb = inode->i_sb;
431 Indirect *p = chain;
432 struct buffer_head *bh;
433
434 *err = 0;
435 /* i_data is not going away, no lock needed */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400436 add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700437 if (!p->key)
438 goto no_block;
439 while (--depth) {
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400440 bh = sb_getblk(sb, le32_to_cpu(p->key));
441 if (unlikely(!bh))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700442 goto failure;
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400443
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400444 if (!bh_uptodate_or_lock(bh)) {
445 if (bh_submit_read(bh) < 0) {
446 put_bh(bh);
447 goto failure;
448 }
449 /* validate block references */
450 if (ext4_check_indirect_blockref(inode, bh)) {
451 put_bh(bh);
452 goto failure;
453 }
454 }
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400455
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400456 add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700457 /* Reader: end */
458 if (!p->key)
459 goto no_block;
460 }
461 return NULL;
462
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700463failure:
464 *err = -EIO;
465no_block:
466 return p;
467}
468
469/**
Mingming Cao617ba132006-10-11 01:20:53 -0700470 * ext4_find_near - find a place for allocation with sufficient locality
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700471 * @inode: owner
472 * @ind: descriptor of indirect block.
473 *
Benoit Boissinot1cc8dcf52008-04-21 22:45:55 +0000474 * This function returns the preferred place for block allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700475 * It is used when heuristic for sequential allocation fails.
476 * Rules are:
477 * + if there is a block to the left of our position - allocate near it.
478 * + if pointer will live in indirect block - allocate near that block.
479 * + if pointer will live in inode - allocate in the same
480 * cylinder group.
481 *
482 * In the latter case we colour the starting block by the callers PID to
483 * prevent it from clashing with concurrent allocations for a different inode
484 * in the same block group. The PID is used here so that functionally related
485 * files will be close-by on-disk.
486 *
487 * Caller must make sure that @ind is valid and will stay that way.
488 */
Mingming Cao617ba132006-10-11 01:20:53 -0700489static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700490{
Mingming Cao617ba132006-10-11 01:20:53 -0700491 struct ext4_inode_info *ei = EXT4_I(inode);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400492 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700493 __le32 *p;
Mingming Cao617ba132006-10-11 01:20:53 -0700494 ext4_fsblk_t bg_start;
Valerie Clement74d34872008-02-15 13:43:07 -0500495 ext4_fsblk_t last_block;
Mingming Cao617ba132006-10-11 01:20:53 -0700496 ext4_grpblk_t colour;
Theodore Ts'oa4912122009-03-12 12:18:34 -0400497 ext4_group_t block_group;
498 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700499
500 /* Try to find previous block */
501 for (p = ind->p - 1; p >= start; p--) {
502 if (*p)
503 return le32_to_cpu(*p);
504 }
505
506 /* No such thing, so let's try location of indirect block */
507 if (ind->bh)
508 return ind->bh->b_blocknr;
509
510 /*
511 * It is going to be referred to from the inode itself? OK, just put it
512 * into the same cylinder group then.
513 */
Theodore Ts'oa4912122009-03-12 12:18:34 -0400514 block_group = ei->i_block_group;
515 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
516 block_group &= ~(flex_size-1);
517 if (S_ISREG(inode->i_mode))
518 block_group++;
519 }
520 bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
Valerie Clement74d34872008-02-15 13:43:07 -0500521 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
522
Theodore Ts'oa4912122009-03-12 12:18:34 -0400523 /*
524 * If we are doing delayed allocation, we don't need take
525 * colour into account.
526 */
527 if (test_opt(inode->i_sb, DELALLOC))
528 return bg_start;
529
Valerie Clement74d34872008-02-15 13:43:07 -0500530 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
531 colour = (current->pid % 16) *
Mingming Cao617ba132006-10-11 01:20:53 -0700532 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
Valerie Clement74d34872008-02-15 13:43:07 -0500533 else
534 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700535 return bg_start + colour;
536}
537
538/**
Benoit Boissinot1cc8dcf52008-04-21 22:45:55 +0000539 * ext4_find_goal - find a preferred place for allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700540 * @inode: owner
541 * @block: block we want
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700542 * @partial: pointer to the last triple within a chain
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700543 *
Benoit Boissinot1cc8dcf52008-04-21 22:45:55 +0000544 * Normally this function find the preferred place for block allocation,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800545 * returns it.
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400546 * Because this is only used for non-extent files, we limit the block nr
547 * to 32 bits.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700548 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500549static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400550 Indirect *partial)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700551{
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400552 ext4_fsblk_t goal;
553
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700554 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -0400555 * XXX need to get goal block from mballoc's data structures
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700556 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700557
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400558 goal = ext4_find_near(inode, partial);
559 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
560 return goal;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700561}
562
563/**
Theodore Ts'o225db7d2010-12-16 16:38:26 -0500564 * ext4_blks_to_allocate - Look up the block map and count the number
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700565 * of direct blocks need to be allocated for the given branch.
566 *
567 * @branch: chain of indirect blocks
568 * @k: number of blocks need for indirect blocks
569 * @blks: number of data blocks to be mapped.
570 * @blocks_to_boundary: the offset in the indirect block
571 *
572 * return the total number of blocks to be allocate, including the
573 * direct and indirect blocks.
574 */
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500575static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400576 int blocks_to_boundary)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700577{
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500578 unsigned int count = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700579
580 /*
581 * Simple case, [t,d]Indirect block(s) has not allocated yet
582 * then it's clear blocks on that path have not allocated
583 */
584 if (k > 0) {
585 /* right now we don't handle cross boundary allocation */
586 if (blks < blocks_to_boundary + 1)
587 count += blks;
588 else
589 count += blocks_to_boundary + 1;
590 return count;
591 }
592
593 count++;
594 while (count < blks && count <= blocks_to_boundary &&
595 le32_to_cpu(*(branch[0].p + count)) == 0) {
596 count++;
597 }
598 return count;
599}
600
601/**
Mingming Cao617ba132006-10-11 01:20:53 -0700602 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
Theodore Ts'o225db7d2010-12-16 16:38:26 -0500603 * @handle: handle for this transaction
604 * @inode: inode which needs allocated blocks
605 * @iblock: the logical block to start allocated at
606 * @goal: preferred physical block of allocation
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700607 * @indirect_blks: the number of blocks need to allocate for indirect
608 * blocks
Theodore Ts'o225db7d2010-12-16 16:38:26 -0500609 * @blks: number of desired blocks
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700610 * @new_blocks: on return it will store the new block numbers for
611 * the indirect blocks(if needed) and the first direct block,
Theodore Ts'o225db7d2010-12-16 16:38:26 -0500612 * @err: on return it will store the error code
613 *
614 * This function will return the number of blocks allocated as
615 * requested by the passed-in parameters.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700616 */
Mingming Cao617ba132006-10-11 01:20:53 -0700617static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400618 ext4_lblk_t iblock, ext4_fsblk_t goal,
619 int indirect_blks, int blks,
620 ext4_fsblk_t new_blocks[4], int *err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700621{
Theodore Ts'o815a1132009-01-01 23:59:43 -0500622 struct ext4_allocation_request ar;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700623 int target, i;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400624 unsigned long count = 0, blk_allocated = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700625 int index = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700626 ext4_fsblk_t current_block = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700627 int ret = 0;
628
629 /*
630 * Here we try to allocate the requested multiple blocks at once,
631 * on a best-effort basis.
632 * To build a branch, we should allocate blocks for
633 * the indirect blocks(if not allocated yet), and at least
634 * the first direct block of this branch. That's the
635 * minimum number of blocks need to allocate(required)
636 */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400637 /* first we try to allocate the indirect blocks */
638 target = indirect_blks;
639 while (target > 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700640 count = target;
641 /* allocating blocks for indirect blocks and direct blocks */
Allison Henderson55f020d2011-05-25 07:41:26 -0400642 current_block = ext4_new_meta_blocks(handle, inode, goal,
643 0, &count, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700644 if (*err)
645 goto failed_out;
646
Frank Mayhar273df552010-03-02 11:46:09 -0500647 if (unlikely(current_block + count > EXT4_MAX_BLOCK_FILE_PHYS)) {
648 EXT4_ERROR_INODE(inode,
649 "current_block %llu + count %lu > %d!",
650 current_block, count,
651 EXT4_MAX_BLOCK_FILE_PHYS);
652 *err = -EIO;
653 goto failed_out;
654 }
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400655
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700656 target -= count;
657 /* allocate blocks for indirect blocks */
658 while (index < indirect_blks && count) {
659 new_blocks[index++] = current_block++;
660 count--;
661 }
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400662 if (count > 0) {
663 /*
664 * save the new block number
665 * for the first direct block
666 */
667 new_blocks[index] = current_block;
668 printk(KERN_INFO "%s returned more blocks than "
669 "requested\n", __func__);
670 WARN_ON(1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700671 break;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400672 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700673 }
674
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400675 target = blks - count ;
676 blk_allocated = count;
677 if (!target)
678 goto allocated;
679 /* Now allocate data blocks */
Theodore Ts'o815a1132009-01-01 23:59:43 -0500680 memset(&ar, 0, sizeof(ar));
681 ar.inode = inode;
682 ar.goal = goal;
683 ar.len = target;
684 ar.logical = iblock;
685 if (S_ISREG(inode->i_mode))
686 /* enable in-core preallocation only for regular files */
687 ar.flags = EXT4_MB_HINT_DATA;
688
689 current_block = ext4_mb_new_blocks(handle, &ar, err);
Frank Mayhar273df552010-03-02 11:46:09 -0500690 if (unlikely(current_block + ar.len > EXT4_MAX_BLOCK_FILE_PHYS)) {
691 EXT4_ERROR_INODE(inode,
692 "current_block %llu + ar.len %d > %d!",
693 current_block, ar.len,
694 EXT4_MAX_BLOCK_FILE_PHYS);
695 *err = -EIO;
696 goto failed_out;
697 }
Theodore Ts'o815a1132009-01-01 23:59:43 -0500698
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400699 if (*err && (target == blks)) {
700 /*
701 * if the allocation failed and we didn't allocate
702 * any blocks before
703 */
704 goto failed_out;
705 }
706 if (!*err) {
707 if (target == blks) {
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400708 /*
709 * save the new block number
710 * for the first direct block
711 */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400712 new_blocks[index] = current_block;
713 }
Theodore Ts'o815a1132009-01-01 23:59:43 -0500714 blk_allocated += ar.len;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400715 }
716allocated:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700717 /* total number of blocks allocated for direct blocks */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400718 ret = blk_allocated;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700719 *err = 0;
720 return ret;
721failed_out:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400722 for (i = 0; i < index; i++)
Peter Huewe7dc57612011-02-21 21:01:42 -0500723 ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700724 return ret;
725}
726
727/**
Mingming Cao617ba132006-10-11 01:20:53 -0700728 * ext4_alloc_branch - allocate and set up a chain of blocks.
Theodore Ts'o225db7d2010-12-16 16:38:26 -0500729 * @handle: handle for this transaction
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700730 * @inode: owner
731 * @indirect_blks: number of allocated indirect blocks
732 * @blks: number of allocated direct blocks
Theodore Ts'o225db7d2010-12-16 16:38:26 -0500733 * @goal: preferred place for allocation
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700734 * @offsets: offsets (in the blocks) to store the pointers to next.
735 * @branch: place to store the chain in.
736 *
737 * This function allocates blocks, zeroes out all but the last one,
738 * links them into chain and (if we are synchronous) writes them to disk.
739 * In other words, it prepares a branch that can be spliced onto the
740 * inode. It stores the information about that chain in the branch[], in
Mingming Cao617ba132006-10-11 01:20:53 -0700741 * the same format as ext4_get_branch() would do. We are calling it after
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700742 * we had read the existing part of chain and partial points to the last
743 * triple of that (one with zero ->key). Upon the exit we have the same
Mingming Cao617ba132006-10-11 01:20:53 -0700744 * picture as after the successful ext4_get_block(), except that in one
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700745 * place chain is disconnected - *branch->p is still zero (we did not
746 * set the last link), but branch->key contains the number that should
747 * be placed into *branch->p to fill that gap.
748 *
749 * If allocation fails we free all blocks we've allocated (and forget
750 * their buffer_heads) and return the error value the from failed
Mingming Cao617ba132006-10-11 01:20:53 -0700751 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700752 * as described above and return 0.
753 */
Mingming Cao617ba132006-10-11 01:20:53 -0700754static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400755 ext4_lblk_t iblock, int indirect_blks,
756 int *blks, ext4_fsblk_t goal,
757 ext4_lblk_t *offsets, Indirect *branch)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700758{
759 int blocksize = inode->i_sb->s_blocksize;
760 int i, n = 0;
761 int err = 0;
762 struct buffer_head *bh;
763 int num;
Mingming Cao617ba132006-10-11 01:20:53 -0700764 ext4_fsblk_t new_blocks[4];
765 ext4_fsblk_t current_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700766
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400767 num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700768 *blks, new_blocks, &err);
769 if (err)
770 return err;
771
772 branch[0].key = cpu_to_le32(new_blocks[0]);
773 /*
774 * metadata blocks and data blocks are allocated.
775 */
776 for (n = 1; n <= indirect_blks; n++) {
777 /*
778 * Get buffer_head for parent block, zero it out
779 * and set the pointer to new one, then send
780 * parent to disk.
781 */
782 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
Namhyung Kim87783692010-10-27 21:30:11 -0400783 if (unlikely(!bh)) {
784 err = -EIO;
785 goto failed;
786 }
787
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700788 branch[n].bh = bh;
789 lock_buffer(bh);
790 BUFFER_TRACE(bh, "call get_create_access");
Mingming Cao617ba132006-10-11 01:20:53 -0700791 err = ext4_journal_get_create_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700792 if (err) {
Curt Wohlgemuth6487a9d2009-07-17 10:54:08 -0400793 /* Don't brelse(bh) here; it's done in
794 * ext4_journal_forget() below */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700795 unlock_buffer(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700796 goto failed;
797 }
798
799 memset(bh->b_data, 0, blocksize);
800 branch[n].p = (__le32 *) bh->b_data + offsets[n];
801 branch[n].key = cpu_to_le32(new_blocks[n]);
802 *branch[n].p = branch[n].key;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400803 if (n == indirect_blks) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700804 current_block = new_blocks[n];
805 /*
806 * End of chain, update the last new metablock of
807 * the chain to point to the new allocated
808 * data blocks numbers
809 */
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400810 for (i = 1; i < num; i++)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700811 *(branch[n].p + i) = cpu_to_le32(++current_block);
812 }
813 BUFFER_TRACE(bh, "marking uptodate");
814 set_buffer_uptodate(bh);
815 unlock_buffer(bh);
816
Frank Mayhar03901312009-01-07 00:06:22 -0500817 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
818 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700819 if (err)
820 goto failed;
821 }
822 *blks = num;
823 return err;
824failed:
825 /* Allocation failed, free what we already allocated */
Peter Huewe7dc57612011-02-21 21:01:42 -0500826 ext4_free_blocks(handle, inode, NULL, new_blocks[0], 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700827 for (i = 1; i <= n ; i++) {
Theodore Ts'o60e66792010-05-17 07:00:00 -0400828 /*
Theodore Ts'oe6362602009-11-23 07:17:05 -0500829 * branch[i].bh is newly allocated, so there is no
830 * need to revoke the block, which is why we don't
831 * need to set EXT4_FREE_BLOCKS_METADATA.
Theodore Ts'ob7e57e72009-11-22 21:00:13 -0500832 */
Peter Huewe7dc57612011-02-21 21:01:42 -0500833 ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1,
Theodore Ts'oe6362602009-11-23 07:17:05 -0500834 EXT4_FREE_BLOCKS_FORGET);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700835 }
Theodore Ts'oe6362602009-11-23 07:17:05 -0500836 for (i = n+1; i < indirect_blks; i++)
Peter Huewe7dc57612011-02-21 21:01:42 -0500837 ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700838
Peter Huewe7dc57612011-02-21 21:01:42 -0500839 ext4_free_blocks(handle, inode, NULL, new_blocks[i], num, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700840
841 return err;
842}
843
844/**
Mingming Cao617ba132006-10-11 01:20:53 -0700845 * ext4_splice_branch - splice the allocated branch onto inode.
Theodore Ts'o225db7d2010-12-16 16:38:26 -0500846 * @handle: handle for this transaction
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700847 * @inode: owner
848 * @block: (logical) number of block we are adding
849 * @chain: chain of indirect blocks (with a missing link - see
Mingming Cao617ba132006-10-11 01:20:53 -0700850 * ext4_alloc_branch)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700851 * @where: location of missing link
852 * @num: number of indirect blocks we are adding
853 * @blks: number of direct blocks we are adding
854 *
855 * This function fills the missing link and does all housekeeping needed in
856 * inode (->i_blocks, etc.). In case of success we end up with the full
857 * chain to new block and return 0.
858 */
Mingming Cao617ba132006-10-11 01:20:53 -0700859static int ext4_splice_branch(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400860 ext4_lblk_t block, Indirect *where, int num,
861 int blks)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700862{
863 int i;
864 int err = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700865 ext4_fsblk_t current_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700866
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700867 /*
868 * If we're splicing into a [td]indirect block (as opposed to the
869 * inode) then we need to get write access to the [td]indirect block
870 * before the splice.
871 */
872 if (where->bh) {
873 BUFFER_TRACE(where->bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -0700874 err = ext4_journal_get_write_access(handle, where->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700875 if (err)
876 goto err_out;
877 }
878 /* That's it */
879
880 *where->p = where->key;
881
882 /*
883 * Update the host buffer_head or inode to point to more just allocated
884 * direct blocks blocks
885 */
886 if (num == 0 && blks > 1) {
887 current_block = le32_to_cpu(where->key) + 1;
888 for (i = 1; i < blks; i++)
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400889 *(where->p + i) = cpu_to_le32(current_block++);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700890 }
891
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700892 /* We are done with atomic stuff, now do the rest of housekeeping */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700893 /* had we spliced it onto indirect block? */
894 if (where->bh) {
895 /*
896 * If we spliced it onto an indirect block, we haven't
897 * altered the inode. Note however that if it is being spliced
898 * onto an indirect block at the very end of the file (the
899 * file is growing) then we *will* alter the inode to reflect
900 * the new i_size. But that is not done here - it is done in
Mingming Cao617ba132006-10-11 01:20:53 -0700901 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700902 */
903 jbd_debug(5, "splicing indirect only\n");
Frank Mayhar03901312009-01-07 00:06:22 -0500904 BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
905 err = ext4_handle_dirty_metadata(handle, inode, where->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700906 if (err)
907 goto err_out;
908 } else {
909 /*
910 * OK, we spliced it into the inode itself on a direct block.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700911 */
Theodore Ts'o41591752009-06-15 03:41:23 -0400912 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700913 jbd_debug(5, "splicing direct\n");
914 }
915 return err;
916
917err_out:
918 for (i = 1; i <= num; i++) {
Theodore Ts'o60e66792010-05-17 07:00:00 -0400919 /*
Theodore Ts'oe6362602009-11-23 07:17:05 -0500920 * branch[i].bh is newly allocated, so there is no
921 * need to revoke the block, which is why we don't
922 * need to set EXT4_FREE_BLOCKS_METADATA.
Theodore Ts'ob7e57e72009-11-22 21:00:13 -0500923 */
Theodore Ts'oe6362602009-11-23 07:17:05 -0500924 ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
925 EXT4_FREE_BLOCKS_FORGET);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700926 }
Peter Huewe7dc57612011-02-21 21:01:42 -0500927 ext4_free_blocks(handle, inode, NULL, le32_to_cpu(where[num].key),
Theodore Ts'oe6362602009-11-23 07:17:05 -0500928 blks, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700929
930 return err;
931}
932
933/*
Theodore Ts'oe35fd662010-05-16 19:00:00 -0400934 * The ext4_ind_map_blocks() function handles non-extents inodes
Theodore Ts'ob920c752009-05-14 00:54:29 -0400935 * (i.e., using the traditional indirect/double-indirect i_blocks
Theodore Ts'oe35fd662010-05-16 19:00:00 -0400936 * scheme) for ext4_map_blocks().
Theodore Ts'ob920c752009-05-14 00:54:29 -0400937 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700938 * Allocation strategy is simple: if we have to allocate something, we will
939 * have to go the whole way to leaf. So let's do it before attaching anything
940 * to tree, set linkage between the newborn blocks, write them if sync is
941 * required, recheck the path, free and repeat if check fails, otherwise
942 * set the last missing link (that will protect us from any truncate-generated
943 * removals - all blocks on the path are immune now) and possibly force the
944 * write on the parent block.
945 * That has a nice additional property: no special recovery from the failed
946 * allocations is needed - we simply release blocks and do not touch anything
947 * reachable from inode.
948 *
949 * `handle' can be NULL if create == 0.
950 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700951 * return > 0, # of blocks mapped or allocated.
952 * return = 0, if plain lookup failed.
953 * return < 0, error case.
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500954 *
Theodore Ts'ob920c752009-05-14 00:54:29 -0400955 * The ext4_ind_get_blocks() function should be called with
956 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
957 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
958 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
959 * blocks.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700960 */
Theodore Ts'oe35fd662010-05-16 19:00:00 -0400961static int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
962 struct ext4_map_blocks *map,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400963 int flags)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700964{
965 int err = -EIO;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500966 ext4_lblk_t offsets[4];
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700967 Indirect chain[4];
968 Indirect *partial;
Mingming Cao617ba132006-10-11 01:20:53 -0700969 ext4_fsblk_t goal;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700970 int indirect_blks;
971 int blocks_to_boundary = 0;
972 int depth;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700973 int count = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700974 ext4_fsblk_t first_block = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700975
Jiaying Zhang0562e0b2011-03-21 21:38:05 -0400976 trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
Dmitry Monakhov12e9b892010-05-16 22:00:00 -0400977 J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
Theodore Ts'oc2177052009-05-14 00:58:52 -0400978 J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
Theodore Ts'oe35fd662010-05-16 19:00:00 -0400979 depth = ext4_block_to_path(inode, map->m_lblk, offsets,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400980 &blocks_to_boundary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700981
982 if (depth == 0)
983 goto out;
984
Mingming Cao617ba132006-10-11 01:20:53 -0700985 partial = ext4_get_branch(inode, depth, offsets, chain, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700986
987 /* Simplest case - block found, no allocation needed */
988 if (!partial) {
989 first_block = le32_to_cpu(chain[depth - 1].key);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700990 count++;
991 /*map more blocks*/
Theodore Ts'oe35fd662010-05-16 19:00:00 -0400992 while (count < map->m_len && count <= blocks_to_boundary) {
Mingming Cao617ba132006-10-11 01:20:53 -0700993 ext4_fsblk_t blk;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700994
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700995 blk = le32_to_cpu(*(chain[depth-1].p + count));
996
997 if (blk == first_block + count)
998 count++;
999 else
1000 break;
1001 }
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05001002 goto got_it;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001003 }
1004
1005 /* Next simple case - plain lookup or failed read of indirect block */
Theodore Ts'oc2177052009-05-14 00:58:52 -04001006 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001007 goto cleanup;
1008
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001009 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04001010 * Okay, we need to do block allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001011 */
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001012 goal = ext4_find_goal(inode, map->m_lblk, partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001013
1014 /* the number of blocks need to allocate for [d,t]indirect blocks */
1015 indirect_blks = (chain + depth) - partial - 1;
1016
1017 /*
1018 * Next look up the indirect map to count the totoal number of
1019 * direct blocks to allocate for this branch.
1020 */
Mingming Cao617ba132006-10-11 01:20:53 -07001021 count = ext4_blks_to_allocate(partial, indirect_blks,
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001022 map->m_len, blocks_to_boundary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001023 /*
Mingming Cao617ba132006-10-11 01:20:53 -07001024 * Block out ext4_truncate while we alter the tree
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001025 */
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001026 err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001027 &count, goal,
1028 offsets + (partial - chain), partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001029
1030 /*
Mingming Cao617ba132006-10-11 01:20:53 -07001031 * The ext4_splice_branch call will free and forget any buffers
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001032 * on the new chain if there is a failure, but that risks using
1033 * up transaction credits, especially for bitmaps where the
1034 * credits cannot be returned. Can we handle this somehow? We
1035 * may need to return -EAGAIN upwards in the worst case. --sct
1036 */
1037 if (!err)
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001038 err = ext4_splice_branch(handle, inode, map->m_lblk,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001039 partial, indirect_blks, count);
Jan Kara2bba7022009-11-23 07:24:48 -05001040 if (err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001041 goto cleanup;
1042
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001043 map->m_flags |= EXT4_MAP_NEW;
Jan Karab436b9b2009-12-08 23:51:10 -05001044
1045 ext4_update_inode_fsync_trans(handle, inode, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001046got_it:
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001047 map->m_flags |= EXT4_MAP_MAPPED;
1048 map->m_pblk = le32_to_cpu(chain[depth-1].key);
1049 map->m_len = count;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001050 if (count > blocks_to_boundary)
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001051 map->m_flags |= EXT4_MAP_BOUNDARY;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001052 err = count;
1053 /* Clean up and exit */
1054 partial = chain + depth - 1; /* the whole chain */
1055cleanup:
1056 while (partial > chain) {
1057 BUFFER_TRACE(partial->bh, "call brelse");
1058 brelse(partial->bh);
1059 partial--;
1060 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001061out:
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04001062 trace_ext4_ind_map_blocks_exit(inode, map->m_lblk,
1063 map->m_pblk, map->m_len, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001064 return err;
1065}
1066
Dmitry Monakhova9e7f442009-12-14 15:21:14 +03001067#ifdef CONFIG_QUOTA
1068qsize_t *ext4_get_reserved_space(struct inode *inode)
Mingming Cao60e58e02009-01-22 18:13:05 +01001069{
Dmitry Monakhova9e7f442009-12-14 15:21:14 +03001070 return &EXT4_I(inode)->i_reserved_quota;
Mingming Cao60e58e02009-01-22 18:13:05 +01001071}
Dmitry Monakhova9e7f442009-12-14 15:21:14 +03001072#endif
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001073
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001074/*
1075 * Calculate the number of metadata blocks need to reserve
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001076 * to allocate a new block at @lblocks for non extent file based file
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001077 */
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001078static int ext4_indirect_calc_metadata_amount(struct inode *inode,
1079 sector_t lblock)
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001080{
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001081 struct ext4_inode_info *ei = EXT4_I(inode);
Jan Karad330a5b2010-03-14 18:17:54 -04001082 sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1);
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001083 int blk_bits;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001084
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001085 if (lblock < EXT4_NDIR_BLOCKS)
1086 return 0;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001087
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001088 lblock -= EXT4_NDIR_BLOCKS;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001089
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001090 if (ei->i_da_metadata_calc_len &&
1091 (lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) {
1092 ei->i_da_metadata_calc_len++;
1093 return 0;
1094 }
1095 ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
1096 ei->i_da_metadata_calc_len = 1;
Jan Karad330a5b2010-03-14 18:17:54 -04001097 blk_bits = order_base_2(lblock);
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001098 return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001099}
1100
1101/*
1102 * Calculate the number of metadata blocks need to reserve
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001103 * to allocate a block located at @lblock
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001104 */
Theodore Ts'o01f49d02011-01-10 12:13:03 -05001105static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001106{
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04001107 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001108 return ext4_ext_calc_metadata_amount(inode, lblock);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001109
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001110 return ext4_indirect_calc_metadata_amount(inode, lblock);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001111}
1112
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001113/*
1114 * Called with i_data_sem down, which is important since we can call
1115 * ext4_discard_preallocations() from here.
1116 */
Aneesh Kumar K.V5f634d02010-01-25 04:00:31 -05001117void ext4_da_update_reserve_space(struct inode *inode,
1118 int used, int quota_claim)
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001119{
1120 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001121 struct ext4_inode_info *ei = EXT4_I(inode);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001122
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001123 spin_lock(&ei->i_block_reservation_lock);
Theodore Ts'of8ec9d62010-01-01 01:00:21 -05001124 trace_ext4_da_update_reserve_space(inode, used);
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001125 if (unlikely(used > ei->i_reserved_data_blocks)) {
1126 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d "
1127 "with only %d reserved data blocks\n",
1128 __func__, inode->i_ino, used,
1129 ei->i_reserved_data_blocks);
1130 WARN_ON(1);
1131 used = ei->i_reserved_data_blocks;
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04001132 }
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001133
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001134 /* Update per-inode reservations */
1135 ei->i_reserved_data_blocks -= used;
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001136 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001137 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1138 used + ei->i_allocated_meta_blocks);
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001139 ei->i_allocated_meta_blocks = 0;
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001140
1141 if (ei->i_reserved_data_blocks == 0) {
1142 /*
1143 * We can release all of the reserved metadata blocks
1144 * only when we have written all of the delayed
1145 * allocation blocks.
1146 */
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001147 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1148 ei->i_reserved_meta_blocks);
Theodore Ts'oee5f4d92010-01-01 02:36:15 -05001149 ei->i_reserved_meta_blocks = 0;
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001150 ei->i_da_metadata_calc_len = 0;
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001151 }
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001152 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Cao60e58e02009-01-22 18:13:05 +01001153
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001154 /* Update quota subsystem for data blocks */
1155 if (quota_claim)
Christoph Hellwig5dd40562010-03-03 09:05:00 -05001156 dquot_claim_block(inode, used);
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001157 else {
Aneesh Kumar K.V5f634d02010-01-25 04:00:31 -05001158 /*
1159 * We did fallocate with an offset that is already delayed
1160 * allocated. So on delayed allocated writeback we should
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001161 * not re-claim the quota for fallocated blocks.
Aneesh Kumar K.V5f634d02010-01-25 04:00:31 -05001162 */
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001163 dquot_release_reservation_block(inode, used);
Aneesh Kumar K.V5f634d02010-01-25 04:00:31 -05001164 }
Aneesh Kumar K.Vd6014302009-03-27 22:36:43 -04001165
1166 /*
1167 * If we have done all the pending block allocations and if
1168 * there aren't any writers on the inode, we can discard the
1169 * inode's preallocations.
1170 */
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001171 if ((ei->i_reserved_data_blocks == 0) &&
1172 (atomic_read(&inode->i_writecount) == 0))
Aneesh Kumar K.Vd6014302009-03-27 22:36:43 -04001173 ext4_discard_preallocations(inode);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001174}
1175
Theodore Ts'oe29136f2010-06-29 12:54:28 -04001176static int __check_block_validity(struct inode *inode, const char *func,
Theodore Ts'oc398eda2010-07-27 11:56:40 -04001177 unsigned int line,
1178 struct ext4_map_blocks *map)
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001179{
Theodore Ts'o24676da2010-05-16 21:00:00 -04001180 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
1181 map->m_len)) {
Theodore Ts'oc398eda2010-07-27 11:56:40 -04001182 ext4_error_inode(inode, func, line, map->m_pblk,
1183 "lblock %lu mapped to illegal pblock "
1184 "(length %d)", (unsigned long) map->m_lblk,
1185 map->m_len);
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001186 return -EIO;
1187 }
1188 return 0;
1189}
1190
Theodore Ts'oe29136f2010-06-29 12:54:28 -04001191#define check_block_validity(inode, map) \
Theodore Ts'oc398eda2010-07-27 11:56:40 -04001192 __check_block_validity((inode), __func__, __LINE__, (map))
Theodore Ts'oe29136f2010-06-29 12:54:28 -04001193
Mingming Caof5ab0d12008-02-25 15:29:55 -05001194/*
Theodore Ts'o1f945332009-09-30 22:57:41 -04001195 * Return the number of contiguous dirty pages in a given inode
1196 * starting at page frame idx.
Theodore Ts'o55138e02009-09-29 13:31:31 -04001197 */
1198static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
1199 unsigned int max_pages)
1200{
1201 struct address_space *mapping = inode->i_mapping;
1202 pgoff_t index;
1203 struct pagevec pvec;
1204 pgoff_t num = 0;
1205 int i, nr_pages, done = 0;
1206
1207 if (max_pages == 0)
1208 return 0;
1209 pagevec_init(&pvec, 0);
1210 while (!done) {
1211 index = idx;
1212 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1213 PAGECACHE_TAG_DIRTY,
1214 (pgoff_t)PAGEVEC_SIZE);
1215 if (nr_pages == 0)
1216 break;
1217 for (i = 0; i < nr_pages; i++) {
1218 struct page *page = pvec.pages[i];
1219 struct buffer_head *bh, *head;
1220
1221 lock_page(page);
1222 if (unlikely(page->mapping != mapping) ||
1223 !PageDirty(page) ||
1224 PageWriteback(page) ||
1225 page->index != idx) {
1226 done = 1;
1227 unlock_page(page);
1228 break;
1229 }
Theodore Ts'o1f945332009-09-30 22:57:41 -04001230 if (page_has_buffers(page)) {
1231 bh = head = page_buffers(page);
1232 do {
1233 if (!buffer_delay(bh) &&
1234 !buffer_unwritten(bh))
1235 done = 1;
1236 bh = bh->b_this_page;
1237 } while (!done && (bh != head));
1238 }
Theodore Ts'o55138e02009-09-29 13:31:31 -04001239 unlock_page(page);
1240 if (done)
1241 break;
1242 idx++;
1243 num++;
Eric Sandeen659c6002010-10-27 21:30:03 -04001244 if (num >= max_pages) {
1245 done = 1;
Theodore Ts'o55138e02009-09-29 13:31:31 -04001246 break;
Eric Sandeen659c6002010-10-27 21:30:03 -04001247 }
Theodore Ts'o55138e02009-09-29 13:31:31 -04001248 }
1249 pagevec_release(&pvec);
1250 }
1251 return num;
1252}
1253
1254/*
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001255 * The ext4_map_blocks() function tries to look up the requested blocks,
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001256 * and returns if the blocks are already mapped.
Mingming Caof5ab0d12008-02-25 15:29:55 -05001257 *
Mingming Caof5ab0d12008-02-25 15:29:55 -05001258 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1259 * and store the allocated blocks in the result buffer head and mark it
1260 * mapped.
1261 *
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001262 * If file type is extents based, it will call ext4_ext_map_blocks(),
1263 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
Mingming Caof5ab0d12008-02-25 15:29:55 -05001264 * based files
1265 *
1266 * On success, it returns the number of blocks being mapped or allocate.
1267 * if create==0 and the blocks are pre-allocated and uninitialized block,
1268 * the result buffer head is unmapped. If the create ==1, it will make sure
1269 * the buffer head is mapped.
1270 *
1271 * It returns 0 if plain look up failed (blocks have not been allocated), in
1272 * that casem, buffer head is unmapped
1273 *
1274 * It returns the error in case of allocation failure.
1275 */
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001276int ext4_map_blocks(handle_t *handle, struct inode *inode,
1277 struct ext4_map_blocks *map, int flags)
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001278{
1279 int retval;
Mingming Caof5ab0d12008-02-25 15:29:55 -05001280
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001281 map->m_flags = 0;
1282 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
1283 "logical block %lu\n", inode->i_ino, flags, map->m_len,
1284 (unsigned long) map->m_lblk);
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001285 /*
Theodore Ts'ob920c752009-05-14 00:54:29 -04001286 * Try to see if we can get the block without requesting a new
1287 * file system block.
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001288 */
1289 down_read((&EXT4_I(inode)->i_data_sem));
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04001290 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001291 retval = ext4_ext_map_blocks(handle, inode, map, 0);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001292 } else {
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001293 retval = ext4_ind_map_blocks(handle, inode, map, 0);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001294 }
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001295 up_read((&EXT4_I(inode)->i_data_sem));
Mingming Caof5ab0d12008-02-25 15:29:55 -05001296
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001297 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
Theodore Ts'oe29136f2010-06-29 12:54:28 -04001298 int ret = check_block_validity(inode, map);
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001299 if (ret != 0)
1300 return ret;
1301 }
1302
Mingming Caof5ab0d12008-02-25 15:29:55 -05001303 /* If it is only a block(s) look up */
Theodore Ts'oc2177052009-05-14 00:58:52 -04001304 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001305 return retval;
1306
1307 /*
Mingming Caof5ab0d12008-02-25 15:29:55 -05001308 * Returns if the blocks have already allocated
1309 *
1310 * Note that if blocks have been preallocated
1311 * ext4_ext_get_block() returns th create = 0
1312 * with buffer head unmapped.
1313 */
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001314 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
Mingming Caof5ab0d12008-02-25 15:29:55 -05001315 return retval;
1316
1317 /*
Aneesh Kumar K.V2a8964d2009-05-14 17:05:39 -04001318 * When we call get_blocks without the create flag, the
1319 * BH_Unwritten flag could have gotten set if the blocks
1320 * requested were part of a uninitialized extent. We need to
1321 * clear this flag now that we are committed to convert all or
1322 * part of the uninitialized extent to be an initialized
1323 * extent. This is because we need to avoid the combination
1324 * of BH_Unwritten and BH_Mapped flags being simultaneously
1325 * set on the buffer_head.
1326 */
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001327 map->m_flags &= ~EXT4_MAP_UNWRITTEN;
Aneesh Kumar K.V2a8964d2009-05-14 17:05:39 -04001328
1329 /*
Mingming Caof5ab0d12008-02-25 15:29:55 -05001330 * New blocks allocate and/or writing to uninitialized extent
1331 * will possibly result in updating i_data, so we take
1332 * the write lock of i_data_sem, and call get_blocks()
1333 * with create == 1 flag.
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001334 */
1335 down_write((&EXT4_I(inode)->i_data_sem));
Mingming Caod2a17632008-07-14 17:52:37 -04001336
1337 /*
1338 * if the caller is from delayed allocation writeout path
1339 * we have already reserved fs blocks for allocation
1340 * let the underlying get_block() function know to
1341 * avoid double accounting
1342 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04001343 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
Theodore Ts'of2321092011-01-10 12:12:36 -05001344 ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001345 /*
1346 * We need to check for EXT4 here because migrate
1347 * could have changed the inode type in between
1348 */
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04001349 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001350 retval = ext4_ext_map_blocks(handle, inode, map, flags);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001351 } else {
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001352 retval = ext4_ind_map_blocks(handle, inode, map, flags);
Aneesh Kumar K.V267e4db2008-04-29 08:11:12 -04001353
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001354 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
Aneesh Kumar K.V267e4db2008-04-29 08:11:12 -04001355 /*
1356 * We allocated new blocks which will result in
1357 * i_data's format changing. Force the migrate
1358 * to fail by clearing migrate flags
1359 */
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05001360 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
Aneesh Kumar K.V267e4db2008-04-29 08:11:12 -04001361 }
Mingming Caod2a17632008-07-14 17:52:37 -04001362
Aneesh Kumar K.V5f634d02010-01-25 04:00:31 -05001363 /*
1364 * Update reserved blocks/metadata blocks after successful
1365 * block allocation which had been deferred till now. We don't
1366 * support fallocate for non extent files. So we can update
1367 * reserve space here.
1368 */
1369 if ((retval > 0) &&
Aneesh Kumar K.V1296cc82010-01-15 01:27:59 -05001370 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
Aneesh Kumar K.V5f634d02010-01-25 04:00:31 -05001371 ext4_da_update_reserve_space(inode, retval, 1);
1372 }
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04001373 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
Theodore Ts'of2321092011-01-10 12:12:36 -05001374 ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04001375
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001376 up_write((&EXT4_I(inode)->i_data_sem));
Theodore Ts'oe35fd662010-05-16 19:00:00 -04001377 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
Theodore Ts'oe29136f2010-06-29 12:54:28 -04001378 int ret = check_block_validity(inode, map);
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001379 if (ret != 0)
1380 return ret;
1381 }
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001382 return retval;
1383}
1384
Mingming Caof3bd1f32008-08-19 22:16:03 -04001385/* Maximum number of blocks we map for direct IO at once. */
1386#define DIO_MAX_BLOCKS 4096
1387
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001388static int _ext4_get_block(struct inode *inode, sector_t iblock,
1389 struct buffer_head *bh, int flags)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001390{
Dmitriy Monakhov3e4fdaf2007-02-10 01:46:35 -08001391 handle_t *handle = ext4_journal_current_handle();
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001392 struct ext4_map_blocks map;
Jan Kara7fb54092008-02-10 01:08:38 -05001393 int ret = 0, started = 0;
Mingming Caof3bd1f32008-08-19 22:16:03 -04001394 int dio_credits;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001395
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001396 map.m_lblk = iblock;
1397 map.m_len = bh->b_size >> inode->i_blkbits;
1398
1399 if (flags && !handle) {
Jan Kara7fb54092008-02-10 01:08:38 -05001400 /* Direct IO write... */
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001401 if (map.m_len > DIO_MAX_BLOCKS)
1402 map.m_len = DIO_MAX_BLOCKS;
1403 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
Mingming Caof3bd1f32008-08-19 22:16:03 -04001404 handle = ext4_journal_start(inode, dio_credits);
Jan Kara7fb54092008-02-10 01:08:38 -05001405 if (IS_ERR(handle)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001406 ret = PTR_ERR(handle);
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001407 return ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001408 }
Jan Kara7fb54092008-02-10 01:08:38 -05001409 started = 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001410 }
1411
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001412 ret = ext4_map_blocks(handle, inode, &map, flags);
Jan Kara7fb54092008-02-10 01:08:38 -05001413 if (ret > 0) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001414 map_bh(bh, inode->i_sb, map.m_pblk);
1415 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1416 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
Jan Kara7fb54092008-02-10 01:08:38 -05001417 ret = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001418 }
Jan Kara7fb54092008-02-10 01:08:38 -05001419 if (started)
1420 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001421 return ret;
1422}
1423
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001424int ext4_get_block(struct inode *inode, sector_t iblock,
1425 struct buffer_head *bh, int create)
1426{
1427 return _ext4_get_block(inode, iblock, bh,
1428 create ? EXT4_GET_BLOCKS_CREATE : 0);
1429}
1430
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001431/*
1432 * `handle' can be NULL if create is zero
1433 */
Mingming Cao617ba132006-10-11 01:20:53 -07001434struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001435 ext4_lblk_t block, int create, int *errp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001436{
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001437 struct ext4_map_blocks map;
1438 struct buffer_head *bh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001439 int fatal = 0, err;
1440
1441 J_ASSERT(handle != NULL || create == 0);
1442
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001443 map.m_lblk = block;
1444 map.m_len = 1;
1445 err = ext4_map_blocks(handle, inode, &map,
1446 create ? EXT4_GET_BLOCKS_CREATE : 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001447
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001448 if (err < 0)
1449 *errp = err;
1450 if (err <= 0)
1451 return NULL;
1452 *errp = 0;
1453
1454 bh = sb_getblk(inode->i_sb, map.m_pblk);
1455 if (!bh) {
1456 *errp = -EIO;
1457 return NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001458 }
Theodore Ts'o2ed88682010-05-16 20:00:00 -04001459 if (map.m_flags & EXT4_MAP_NEW) {
1460 J_ASSERT(create != 0);
1461 J_ASSERT(handle != NULL);
1462
1463 /*
1464 * Now that we do not always journal data, we should
1465 * keep in mind whether this should always journal the
1466 * new buffer as metadata. For now, regular file
1467 * writes use ext4_get_block instead, so it's not a
1468 * problem.
1469 */
1470 lock_buffer(bh);
1471 BUFFER_TRACE(bh, "call get_create_access");
1472 fatal = ext4_journal_get_create_access(handle, bh);
1473 if (!fatal && !buffer_uptodate(bh)) {
1474 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
1475 set_buffer_uptodate(bh);
1476 }
1477 unlock_buffer(bh);
1478 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1479 err = ext4_handle_dirty_metadata(handle, inode, bh);
1480 if (!fatal)
1481 fatal = err;
1482 } else {
1483 BUFFER_TRACE(bh, "not a new buffer");
1484 }
1485 if (fatal) {
1486 *errp = fatal;
1487 brelse(bh);
1488 bh = NULL;
1489 }
1490 return bh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001491}
1492
Mingming Cao617ba132006-10-11 01:20:53 -07001493struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001494 ext4_lblk_t block, int create, int *err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001495{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001496 struct buffer_head *bh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001497
Mingming Cao617ba132006-10-11 01:20:53 -07001498 bh = ext4_getblk(handle, inode, block, create, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001499 if (!bh)
1500 return bh;
1501 if (buffer_uptodate(bh))
1502 return bh;
1503 ll_rw_block(READ_META, 1, &bh);
1504 wait_on_buffer(bh);
1505 if (buffer_uptodate(bh))
1506 return bh;
1507 put_bh(bh);
1508 *err = -EIO;
1509 return NULL;
1510}
1511
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001512static int walk_page_buffers(handle_t *handle,
1513 struct buffer_head *head,
1514 unsigned from,
1515 unsigned to,
1516 int *partial,
1517 int (*fn)(handle_t *handle,
1518 struct buffer_head *bh))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001519{
1520 struct buffer_head *bh;
1521 unsigned block_start, block_end;
1522 unsigned blocksize = head->b_size;
1523 int err, ret = 0;
1524 struct buffer_head *next;
1525
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001526 for (bh = head, block_start = 0;
1527 ret == 0 && (bh != head || !block_start);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001528 block_start = block_end, bh = next) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001529 next = bh->b_this_page;
1530 block_end = block_start + blocksize;
1531 if (block_end <= from || block_start >= to) {
1532 if (partial && !buffer_uptodate(bh))
1533 *partial = 1;
1534 continue;
1535 }
1536 err = (*fn)(handle, bh);
1537 if (!ret)
1538 ret = err;
1539 }
1540 return ret;
1541}
1542
1543/*
1544 * To preserve ordering, it is essential that the hole instantiation and
1545 * the data write be encapsulated in a single transaction. We cannot
Mingming Cao617ba132006-10-11 01:20:53 -07001546 * close off a transaction and start a new one between the ext4_get_block()
Mingming Caodab291a2006-10-11 01:21:01 -07001547 * and the commit_write(). So doing the jbd2_journal_start at the start of
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001548 * prepare_write() is the right place.
1549 *
Mingming Cao617ba132006-10-11 01:20:53 -07001550 * Also, this function can nest inside ext4_writepage() ->
1551 * block_write_full_page(). In that case, we *know* that ext4_writepage()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001552 * has generated enough buffer credits to do the whole page. So we won't
1553 * block on the journal in that case, which is good, because the caller may
1554 * be PF_MEMALLOC.
1555 *
Mingming Cao617ba132006-10-11 01:20:53 -07001556 * By accident, ext4 can be reentered when a transaction is open via
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001557 * quota file writes. If we were to commit the transaction while thus
1558 * reentered, there can be a deadlock - we would be holding a quota
1559 * lock, and the commit would never complete if another thread had a
1560 * transaction open and was blocking on the quota lock - a ranking
1561 * violation.
1562 *
Mingming Caodab291a2006-10-11 01:21:01 -07001563 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001564 * will _not_ run commit under these circumstances because handle->h_ref
1565 * is elevated. We'll still have enough credits for the tiny quotafile
1566 * write.
1567 */
1568static int do_journal_get_write_access(handle_t *handle,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001569 struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001570{
Jan Kara56d35a42010-08-05 14:41:42 -04001571 int dirty = buffer_dirty(bh);
1572 int ret;
1573
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001574 if (!buffer_mapped(bh) || buffer_freed(bh))
1575 return 0;
Jan Kara56d35a42010-08-05 14:41:42 -04001576 /*
Christoph Hellwigebdec242010-10-06 10:47:23 +02001577 * __block_write_begin() could have dirtied some buffers. Clean
Jan Kara56d35a42010-08-05 14:41:42 -04001578 * the dirty bit as jbd2_journal_get_write_access() could complain
1579 * otherwise about fs integrity issues. Setting of the dirty bit
Christoph Hellwigebdec242010-10-06 10:47:23 +02001580 * by __block_write_begin() isn't a real problem here as we clear
Jan Kara56d35a42010-08-05 14:41:42 -04001581 * the bit before releasing a page lock and thus writeback cannot
1582 * ever write the buffer.
1583 */
1584 if (dirty)
1585 clear_buffer_dirty(bh);
1586 ret = ext4_journal_get_write_access(handle, bh);
1587 if (!ret && dirty)
1588 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1589 return ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001590}
1591
Jan Karab9a42072009-12-08 21:24:33 -05001592/*
1593 * Truncate blocks that were not used by write. We have to truncate the
1594 * pagecache as well so that corresponding buffers get properly unmapped.
1595 */
1596static void ext4_truncate_failed_write(struct inode *inode)
1597{
1598 truncate_inode_pages(inode->i_mapping, inode->i_size);
1599 ext4_truncate(inode);
1600}
1601
Jiaying Zhang744692d2010-03-04 16:14:02 -05001602static int ext4_get_block_write(struct inode *inode, sector_t iblock,
1603 struct buffer_head *bh_result, int create);
Nick Pigginbfc1af62007-10-16 01:25:05 -07001604static int ext4_write_begin(struct file *file, struct address_space *mapping,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001605 loff_t pos, unsigned len, unsigned flags,
1606 struct page **pagep, void **fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001607{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001608 struct inode *inode = mapping->host;
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001609 int ret, needed_blocks;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001610 handle_t *handle;
1611 int retries = 0;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001612 struct page *page;
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001613 pgoff_t index;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001614 unsigned from, to;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001615
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001616 trace_ext4_write_begin(inode, pos, len, flags);
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001617 /*
1618 * Reserve one block more for addition to orphan list in case
1619 * we allocate blocks but write fails for some reason
1620 */
1621 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001622 index = pos >> PAGE_CACHE_SHIFT;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001623 from = pos & (PAGE_CACHE_SIZE - 1);
1624 to = from + len;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001625
1626retry:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001627 handle = ext4_journal_start(inode, needed_blocks);
1628 if (IS_ERR(handle)) {
1629 ret = PTR_ERR(handle);
1630 goto out;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001631 }
1632
Jan Karaebd36102009-02-22 21:09:59 -05001633 /* We cannot recurse into the filesystem as the transaction is already
1634 * started */
1635 flags |= AOP_FLAG_NOFS;
1636
Nick Piggin54566b22009-01-04 12:00:53 -08001637 page = grab_cache_page_write_begin(mapping, index, flags);
Jan Karacf108bc2008-07-11 19:27:31 -04001638 if (!page) {
1639 ext4_journal_stop(handle);
1640 ret = -ENOMEM;
1641 goto out;
1642 }
1643 *pagep = page;
1644
Jiaying Zhang744692d2010-03-04 16:14:02 -05001645 if (ext4_should_dioread_nolock(inode))
Christoph Hellwig6e1db882010-06-04 11:29:57 +02001646 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
Jiaying Zhang744692d2010-03-04 16:14:02 -05001647 else
Christoph Hellwig6e1db882010-06-04 11:29:57 +02001648 ret = __block_write_begin(page, pos, len, ext4_get_block);
Nick Pigginbfc1af62007-10-16 01:25:05 -07001649
1650 if (!ret && ext4_should_journal_data(inode)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001651 ret = walk_page_buffers(handle, page_buffers(page),
1652 from, to, NULL, do_journal_get_write_access);
1653 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001654
1655 if (ret) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001656 unlock_page(page);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001657 page_cache_release(page);
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001658 /*
Christoph Hellwig6e1db882010-06-04 11:29:57 +02001659 * __block_write_begin may have instantiated a few blocks
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001660 * outside i_size. Trim these off again. Don't need
1661 * i_size_read because we hold i_mutex.
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001662 *
1663 * Add inode to orphan list in case we crash before
1664 * truncate finishes
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001665 */
Jan Karaffacfa72009-07-13 16:22:22 -04001666 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001667 ext4_orphan_add(handle, inode);
1668
1669 ext4_journal_stop(handle);
1670 if (pos + len > inode->i_size) {
Jan Karab9a42072009-12-08 21:24:33 -05001671 ext4_truncate_failed_write(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001672 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001673 * If truncate failed early the inode might
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001674 * still be on the orphan list; we need to
1675 * make sure the inode is removed from the
1676 * orphan list in that case.
1677 */
1678 if (inode->i_nlink)
1679 ext4_orphan_del(NULL, inode);
1680 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001681 }
1682
Mingming Cao617ba132006-10-11 01:20:53 -07001683 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001684 goto retry;
Andrew Morton7479d2b2007-04-01 23:49:44 -07001685out:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001686 return ret;
1687}
1688
Nick Pigginbfc1af62007-10-16 01:25:05 -07001689/* For write_end() in data=journal mode */
1690static int write_end_fn(handle_t *handle, struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001691{
1692 if (!buffer_mapped(bh) || buffer_freed(bh))
1693 return 0;
1694 set_buffer_uptodate(bh);
Frank Mayhar03901312009-01-07 00:06:22 -05001695 return ext4_handle_dirty_metadata(handle, NULL, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001696}
1697
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001698static int ext4_generic_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001699 struct address_space *mapping,
1700 loff_t pos, unsigned len, unsigned copied,
1701 struct page *page, void *fsdata)
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001702{
1703 int i_size_changed = 0;
1704 struct inode *inode = mapping->host;
1705 handle_t *handle = ext4_journal_current_handle();
1706
1707 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1708
1709 /*
1710 * No need to use i_size_read() here, the i_size
1711 * cannot change under us because we hold i_mutex.
1712 *
1713 * But it's important to update i_size while still holding page lock:
1714 * page writeout could otherwise come in and zero beyond i_size.
1715 */
1716 if (pos + copied > inode->i_size) {
1717 i_size_write(inode, pos + copied);
1718 i_size_changed = 1;
1719 }
1720
1721 if (pos + copied > EXT4_I(inode)->i_disksize) {
1722 /* We need to mark inode dirty even if
1723 * new_i_size is less that inode->i_size
1724 * bu greater than i_disksize.(hint delalloc)
1725 */
1726 ext4_update_i_disksize(inode, (pos + copied));
1727 i_size_changed = 1;
1728 }
1729 unlock_page(page);
1730 page_cache_release(page);
1731
1732 /*
1733 * Don't mark the inode dirty under page lock. First, it unnecessarily
1734 * makes the holding time of page lock longer. Second, it forces lock
1735 * ordering of page lock and transaction start for journaling
1736 * filesystems.
1737 */
1738 if (i_size_changed)
1739 ext4_mark_inode_dirty(handle, inode);
1740
1741 return copied;
1742}
1743
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001744/*
1745 * We need to pick up the new inode size which generic_commit_write gave us
1746 * `file' can be NULL - eg, when called from page_symlink().
1747 *
Mingming Cao617ba132006-10-11 01:20:53 -07001748 * ext4 never places buffers on inode->i_mapping->private_list. metadata
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001749 * buffers are managed internally.
1750 */
Nick Pigginbfc1af62007-10-16 01:25:05 -07001751static int ext4_ordered_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001752 struct address_space *mapping,
1753 loff_t pos, unsigned len, unsigned copied,
1754 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001755{
Mingming Cao617ba132006-10-11 01:20:53 -07001756 handle_t *handle = ext4_journal_current_handle();
Jan Karacf108bc2008-07-11 19:27:31 -04001757 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001758 int ret = 0, ret2;
1759
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001760 trace_ext4_ordered_write_end(inode, pos, len, copied);
Jan Kara678aaf42008-07-11 19:27:31 -04001761 ret = ext4_jbd2_file_inode(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001762
1763 if (ret == 0) {
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001764 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001765 page, fsdata);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001766 copied = ret2;
Jan Karaffacfa72009-07-13 16:22:22 -04001767 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001768 /* if we have allocated more blocks and copied
1769 * less. We will have blocks allocated outside
1770 * inode->i_size. So truncate them
1771 */
1772 ext4_orphan_add(handle, inode);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001773 if (ret2 < 0)
1774 ret = ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001775 }
Mingming Cao617ba132006-10-11 01:20:53 -07001776 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001777 if (!ret)
1778 ret = ret2;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001779
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001780 if (pos + len > inode->i_size) {
Jan Karab9a42072009-12-08 21:24:33 -05001781 ext4_truncate_failed_write(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001782 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001783 * If truncate failed early the inode might still be
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001784 * on the orphan list; we need to make sure the inode
1785 * is removed from the orphan list in that case.
1786 */
1787 if (inode->i_nlink)
1788 ext4_orphan_del(NULL, inode);
1789 }
1790
1791
Nick Pigginbfc1af62007-10-16 01:25:05 -07001792 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001793}
1794
Nick Pigginbfc1af62007-10-16 01:25:05 -07001795static int ext4_writeback_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001796 struct address_space *mapping,
1797 loff_t pos, unsigned len, unsigned copied,
1798 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001799{
Mingming Cao617ba132006-10-11 01:20:53 -07001800 handle_t *handle = ext4_journal_current_handle();
Jan Karacf108bc2008-07-11 19:27:31 -04001801 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001802 int ret = 0, ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001803
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001804 trace_ext4_writeback_write_end(inode, pos, len, copied);
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001805 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001806 page, fsdata);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001807 copied = ret2;
Jan Karaffacfa72009-07-13 16:22:22 -04001808 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001809 /* if we have allocated more blocks and copied
1810 * less. We will have blocks allocated outside
1811 * inode->i_size. So truncate them
1812 */
1813 ext4_orphan_add(handle, inode);
1814
Roel Kluinf8a87d82008-04-29 22:01:18 -04001815 if (ret2 < 0)
1816 ret = ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001817
Mingming Cao617ba132006-10-11 01:20:53 -07001818 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001819 if (!ret)
1820 ret = ret2;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001821
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001822 if (pos + len > inode->i_size) {
Jan Karab9a42072009-12-08 21:24:33 -05001823 ext4_truncate_failed_write(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001824 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001825 * If truncate failed early the inode might still be
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001826 * on the orphan list; we need to make sure the inode
1827 * is removed from the orphan list in that case.
1828 */
1829 if (inode->i_nlink)
1830 ext4_orphan_del(NULL, inode);
1831 }
1832
Nick Pigginbfc1af62007-10-16 01:25:05 -07001833 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001834}
1835
Nick Pigginbfc1af62007-10-16 01:25:05 -07001836static int ext4_journalled_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001837 struct address_space *mapping,
1838 loff_t pos, unsigned len, unsigned copied,
1839 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001840{
Mingming Cao617ba132006-10-11 01:20:53 -07001841 handle_t *handle = ext4_journal_current_handle();
Nick Pigginbfc1af62007-10-16 01:25:05 -07001842 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001843 int ret = 0, ret2;
1844 int partial = 0;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001845 unsigned from, to;
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001846 loff_t new_i_size;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001847
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001848 trace_ext4_journalled_write_end(inode, pos, len, copied);
Nick Pigginbfc1af62007-10-16 01:25:05 -07001849 from = pos & (PAGE_CACHE_SIZE - 1);
1850 to = from + len;
1851
1852 if (copied < len) {
1853 if (!PageUptodate(page))
1854 copied = 0;
1855 page_zero_new_buffers(page, from+copied, to);
1856 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001857
1858 ret = walk_page_buffers(handle, page_buffers(page), from,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001859 to, &partial, write_end_fn);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001860 if (!partial)
1861 SetPageUptodate(page);
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001862 new_i_size = pos + copied;
1863 if (new_i_size > inode->i_size)
Nick Pigginbfc1af62007-10-16 01:25:05 -07001864 i_size_write(inode, pos+copied);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05001865 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001866 if (new_i_size > EXT4_I(inode)->i_disksize) {
1867 ext4_update_i_disksize(inode, new_i_size);
Mingming Cao617ba132006-10-11 01:20:53 -07001868 ret2 = ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001869 if (!ret)
1870 ret = ret2;
1871 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001872
Jan Karacf108bc2008-07-11 19:27:31 -04001873 unlock_page(page);
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001874 page_cache_release(page);
Jan Karaffacfa72009-07-13 16:22:22 -04001875 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001876 /* if we have allocated more blocks and copied
1877 * less. We will have blocks allocated outside
1878 * inode->i_size. So truncate them
1879 */
1880 ext4_orphan_add(handle, inode);
1881
Mingming Cao617ba132006-10-11 01:20:53 -07001882 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001883 if (!ret)
1884 ret = ret2;
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001885 if (pos + len > inode->i_size) {
Jan Karab9a42072009-12-08 21:24:33 -05001886 ext4_truncate_failed_write(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001887 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001888 * If truncate failed early the inode might still be
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001889 * on the orphan list; we need to make sure the inode
1890 * is removed from the orphan list in that case.
1891 */
1892 if (inode->i_nlink)
1893 ext4_orphan_del(NULL, inode);
1894 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001895
1896 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001897}
Mingming Caod2a17632008-07-14 17:52:37 -04001898
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001899/*
1900 * Reserve a single block located at lblock
1901 */
Theodore Ts'o01f49d02011-01-10 12:13:03 -05001902static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
Mingming Caod2a17632008-07-14 17:52:37 -04001903{
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001904 int retries = 0;
Mingming Cao60e58e02009-01-22 18:13:05 +01001905 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001906 struct ext4_inode_info *ei = EXT4_I(inode);
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001907 unsigned long md_needed;
Christoph Hellwig5dd40562010-03-03 09:05:00 -05001908 int ret;
Mingming Caod2a17632008-07-14 17:52:37 -04001909
1910 /*
1911 * recalculate the amount of metadata blocks to reserve
1912 * in order to allocate nrblocks
1913 * worse case is one extent per block
1914 */
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001915repeat:
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001916 spin_lock(&ei->i_block_reservation_lock);
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001917 md_needed = ext4_calc_metadata_amount(inode, lblock);
Theodore Ts'of8ec9d62010-01-01 01:00:21 -05001918 trace_ext4_da_reserve_space(inode, md_needed);
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001919 spin_unlock(&ei->i_block_reservation_lock);
Mingming Caod2a17632008-07-14 17:52:37 -04001920
Mingming Cao60e58e02009-01-22 18:13:05 +01001921 /*
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001922 * We will charge metadata quota at writeout time; this saves
1923 * us from metadata over-estimation, though we may go over by
1924 * a small amount in the end. Here we just reserve for data.
Mingming Cao60e58e02009-01-22 18:13:05 +01001925 */
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001926 ret = dquot_reserve_block(inode, 1);
Christoph Hellwig5dd40562010-03-03 09:05:00 -05001927 if (ret)
1928 return ret;
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001929 /*
1930 * We do still charge estimated metadata to the sb though;
1931 * we cannot afford to run out of free blocks.
1932 */
Allison Henderson55f020d2011-05-25 07:41:26 -04001933 if (ext4_claim_free_blocks(sbi, md_needed + 1, 0)) {
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001934 dquot_release_reservation_block(inode, 1);
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001935 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1936 yield();
1937 goto repeat;
1938 }
Mingming Caod2a17632008-07-14 17:52:37 -04001939 return -ENOSPC;
1940 }
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001941 spin_lock(&ei->i_block_reservation_lock);
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001942 ei->i_reserved_data_blocks++;
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001943 ei->i_reserved_meta_blocks += md_needed;
1944 spin_unlock(&ei->i_block_reservation_lock);
Dmitry Monakhov39bc6802009-12-10 16:36:27 +00001945
Mingming Caod2a17632008-07-14 17:52:37 -04001946 return 0; /* success */
1947}
1948
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001949static void ext4_da_release_space(struct inode *inode, int to_free)
Mingming Caod2a17632008-07-14 17:52:37 -04001950{
1951 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001952 struct ext4_inode_info *ei = EXT4_I(inode);
Mingming Caod2a17632008-07-14 17:52:37 -04001953
Mingming Caocd213222008-08-19 22:16:59 -04001954 if (!to_free)
1955 return; /* Nothing to release, exit */
1956
Mingming Caod2a17632008-07-14 17:52:37 -04001957 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Caocd213222008-08-19 22:16:59 -04001958
Li Zefan5a58ec82010-05-17 02:00:00 -04001959 trace_ext4_da_release_space(inode, to_free);
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001960 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
Mingming Caocd213222008-08-19 22:16:59 -04001961 /*
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001962 * if there aren't enough reserved blocks, then the
1963 * counter is messed up somewhere. Since this
1964 * function is called from invalidate page, it's
1965 * harmless to return without any action.
Mingming Caocd213222008-08-19 22:16:59 -04001966 */
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001967 ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: "
1968 "ino %lu, to_free %d with only %d reserved "
1969 "data blocks\n", inode->i_ino, to_free,
1970 ei->i_reserved_data_blocks);
1971 WARN_ON(1);
1972 to_free = ei->i_reserved_data_blocks;
1973 }
1974 ei->i_reserved_data_blocks -= to_free;
1975
1976 if (ei->i_reserved_data_blocks == 0) {
1977 /*
1978 * We can release all of the reserved metadata blocks
1979 * only when we have written all of the delayed
1980 * allocation blocks.
1981 */
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001982 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1983 ei->i_reserved_meta_blocks);
Theodore Ts'oee5f4d92010-01-01 02:36:15 -05001984 ei->i_reserved_meta_blocks = 0;
Theodore Ts'o9d0be502010-01-01 02:41:30 -05001985 ei->i_da_metadata_calc_len = 0;
Mingming Caocd213222008-08-19 22:16:59 -04001986 }
1987
Eric Sandeen72b8ab92010-05-16 11:00:00 -04001988 /* update fs dirty data blocks counter */
Theodore Ts'o0637c6f2009-12-30 14:20:45 -05001989 percpu_counter_sub(&sbi->s_dirtyblocks_counter, to_free);
Mingming Caod2a17632008-07-14 17:52:37 -04001990
Mingming Caod2a17632008-07-14 17:52:37 -04001991 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Cao60e58e02009-01-22 18:13:05 +01001992
Christoph Hellwig5dd40562010-03-03 09:05:00 -05001993 dquot_release_reservation_block(inode, to_free);
Mingming Caod2a17632008-07-14 17:52:37 -04001994}
1995
1996static void ext4_da_page_release_reservation(struct page *page,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001997 unsigned long offset)
Mingming Caod2a17632008-07-14 17:52:37 -04001998{
1999 int to_release = 0;
2000 struct buffer_head *head, *bh;
2001 unsigned int curr_off = 0;
2002
2003 head = page_buffers(page);
2004 bh = head;
2005 do {
2006 unsigned int next_off = curr_off + bh->b_size;
2007
2008 if ((offset <= curr_off) && (buffer_delay(bh))) {
2009 to_release++;
2010 clear_buffer_delay(bh);
2011 }
2012 curr_off = next_off;
2013 } while ((bh = bh->b_this_page) != head);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04002014 ext4_da_release_space(page->mapping->host, to_release);
Mingming Caod2a17632008-07-14 17:52:37 -04002015}
Dave Kleikampac27a0e2006-10-11 01:20:50 -07002016
2017/*
Alex Tomas64769242008-07-11 19:27:31 -04002018 * Delayed allocation stuff
2019 */
2020
Alex Tomas64769242008-07-11 19:27:31 -04002021/*
2022 * mpage_da_submit_io - walks through extent of pages and try to write
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002023 * them with writepage() call back
Alex Tomas64769242008-07-11 19:27:31 -04002024 *
2025 * @mpd->inode: inode
2026 * @mpd->first_page: first page of the extent
2027 * @mpd->next_page: page after the last page of the extent
Alex Tomas64769242008-07-11 19:27:31 -04002028 *
2029 * By the time mpage_da_submit_io() is called we expect all blocks
2030 * to be allocated. this may be wrong if allocation failed.
2031 *
2032 * As pages are already locked by write_cache_pages(), we can't use it
2033 */
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002034static int mpage_da_submit_io(struct mpage_da_data *mpd,
2035 struct ext4_map_blocks *map)
Alex Tomas64769242008-07-11 19:27:31 -04002036{
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002037 struct pagevec pvec;
2038 unsigned long index, end;
2039 int ret = 0, err, nr_pages, i;
2040 struct inode *inode = mpd->inode;
2041 struct address_space *mapping = inode->i_mapping;
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002042 loff_t size = i_size_read(inode);
Theodore Ts'o3ecdb3a2010-10-27 21:30:10 -04002043 unsigned int len, block_start;
2044 struct buffer_head *bh, *page_bufs = NULL;
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002045 int journal_data = ext4_should_journal_data(inode);
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002046 sector_t pblock = 0, cur_logical = 0;
Theodore Ts'obd2d0212010-10-27 21:30:10 -04002047 struct ext4_io_submit io_submit;
Alex Tomas64769242008-07-11 19:27:31 -04002048
2049 BUG_ON(mpd->next_page <= mpd->first_page);
Theodore Ts'obd2d0212010-10-27 21:30:10 -04002050 memset(&io_submit, 0, sizeof(io_submit));
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002051 /*
2052 * We need to start from the first_page to the next_page - 1
2053 * to make sure we also write the mapped dirty buffer_heads.
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002054 * If we look at mpd->b_blocknr we would only be looking
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002055 * at the currently mapped buffer_heads.
2056 */
Alex Tomas64769242008-07-11 19:27:31 -04002057 index = mpd->first_page;
2058 end = mpd->next_page - 1;
2059
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002060 pagevec_init(&pvec, 0);
Alex Tomas64769242008-07-11 19:27:31 -04002061 while (index <= end) {
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002062 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
Alex Tomas64769242008-07-11 19:27:31 -04002063 if (nr_pages == 0)
2064 break;
2065 for (i = 0; i < nr_pages; i++) {
Theodore Ts'o97498952011-02-26 14:08:01 -05002066 int commit_write = 0, skip_page = 0;
Alex Tomas64769242008-07-11 19:27:31 -04002067 struct page *page = pvec.pages[i];
2068
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002069 index = page->index;
2070 if (index > end)
2071 break;
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002072
2073 if (index == size >> PAGE_CACHE_SHIFT)
2074 len = size & ~PAGE_CACHE_MASK;
2075 else
2076 len = PAGE_CACHE_SIZE;
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002077 if (map) {
2078 cur_logical = index << (PAGE_CACHE_SHIFT -
2079 inode->i_blkbits);
2080 pblock = map->m_pblk + (cur_logical -
2081 map->m_lblk);
2082 }
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002083 index++;
2084
2085 BUG_ON(!PageLocked(page));
2086 BUG_ON(PageWriteback(page));
2087
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002088 /*
2089 * If the page does not have buffers (for
2090 * whatever reason), try to create them using
Theodore Ts'oa107e5a2010-10-27 23:44:47 -04002091 * __block_write_begin. If this fails,
Theodore Ts'o97498952011-02-26 14:08:01 -05002092 * skip the page and move on.
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002093 */
2094 if (!page_has_buffers(page)) {
Theodore Ts'oa107e5a2010-10-27 23:44:47 -04002095 if (__block_write_begin(page, 0, len,
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002096 noalloc_get_block_write)) {
Theodore Ts'o97498952011-02-26 14:08:01 -05002097 skip_page:
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002098 unlock_page(page);
2099 continue;
2100 }
2101 commit_write = 1;
2102 }
Theodore Ts'o3ecdb3a2010-10-27 21:30:10 -04002103
2104 bh = page_bufs = page_buffers(page);
2105 block_start = 0;
2106 do {
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002107 if (!bh)
Theodore Ts'o97498952011-02-26 14:08:01 -05002108 goto skip_page;
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002109 if (map && (cur_logical >= map->m_lblk) &&
2110 (cur_logical <= (map->m_lblk +
2111 (map->m_len - 1)))) {
2112 if (buffer_delay(bh)) {
2113 clear_buffer_delay(bh);
2114 bh->b_blocknr = pblock;
2115 }
2116 if (buffer_unwritten(bh) ||
2117 buffer_mapped(bh))
2118 BUG_ON(bh->b_blocknr != pblock);
2119 if (map->m_flags & EXT4_MAP_UNINIT)
2120 set_buffer_uninit(bh);
2121 clear_buffer_unwritten(bh);
2122 }
2123
Theodore Ts'o97498952011-02-26 14:08:01 -05002124 /* skip page if block allocation undone */
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002125 if (buffer_delay(bh) || buffer_unwritten(bh))
Theodore Ts'o97498952011-02-26 14:08:01 -05002126 skip_page = 1;
Theodore Ts'o3ecdb3a2010-10-27 21:30:10 -04002127 bh = bh->b_this_page;
2128 block_start += bh->b_size;
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002129 cur_logical++;
2130 pblock++;
2131 } while (bh != page_bufs);
2132
Theodore Ts'o97498952011-02-26 14:08:01 -05002133 if (skip_page)
2134 goto skip_page;
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002135
2136 if (commit_write)
2137 /* mark the buffer_heads as dirty & uptodate */
2138 block_commit_write(page, 0, len);
2139
Theodore Ts'o97498952011-02-26 14:08:01 -05002140 clear_page_dirty_for_io(page);
Theodore Ts'obd2d0212010-10-27 21:30:10 -04002141 /*
2142 * Delalloc doesn't support data journalling,
2143 * but eventually maybe we'll lift this
2144 * restriction.
2145 */
2146 if (unlikely(journal_data && PageChecked(page)))
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002147 err = __ext4_journalled_writepage(page, len);
Theodore Ts'o14490322010-12-14 15:27:50 -05002148 else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT))
Theodore Ts'obd2d0212010-10-27 21:30:10 -04002149 err = ext4_bio_write_page(&io_submit, page,
2150 len, mpd->wbc);
Theodore Ts'o14490322010-12-14 15:27:50 -05002151 else
2152 err = block_write_full_page(page,
2153 noalloc_get_block_write, mpd->wbc);
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002154
2155 if (!err)
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002156 mpd->pages_written++;
Alex Tomas64769242008-07-11 19:27:31 -04002157 /*
2158 * In error case, we have to continue because
2159 * remaining pages are still locked
Alex Tomas64769242008-07-11 19:27:31 -04002160 */
2161 if (ret == 0)
2162 ret = err;
2163 }
2164 pagevec_release(&pvec);
2165 }
Theodore Ts'obd2d0212010-10-27 21:30:10 -04002166 ext4_io_submit(&io_submit);
Alex Tomas64769242008-07-11 19:27:31 -04002167 return ret;
2168}
2169
Curt Wohlgemuthc7f59382011-02-26 12:27:52 -05002170static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002171{
2172 int nr_pages, i;
2173 pgoff_t index, end;
2174 struct pagevec pvec;
2175 struct inode *inode = mpd->inode;
2176 struct address_space *mapping = inode->i_mapping;
2177
Curt Wohlgemuthc7f59382011-02-26 12:27:52 -05002178 index = mpd->first_page;
2179 end = mpd->next_page - 1;
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002180 while (index <= end) {
2181 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2182 if (nr_pages == 0)
2183 break;
2184 for (i = 0; i < nr_pages; i++) {
2185 struct page *page = pvec.pages[i];
Jan Kara9b1d09982010-03-03 16:19:32 -05002186 if (page->index > end)
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002187 break;
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002188 BUG_ON(!PageLocked(page));
2189 BUG_ON(PageWriteback(page));
2190 block_invalidatepage(page, 0);
2191 ClearPageUptodate(page);
2192 unlock_page(page);
2193 }
Jan Kara9b1d09982010-03-03 16:19:32 -05002194 index = pvec.pages[nr_pages - 1]->index + 1;
2195 pagevec_release(&pvec);
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002196 }
2197 return;
2198}
2199
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002200static void ext4_print_free_blocks(struct inode *inode)
2201{
2202 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Theodore Ts'o16939182009-09-26 17:43:59 -04002203 printk(KERN_CRIT "Total free blocks count %lld\n",
2204 ext4_count_free_blocks(inode->i_sb));
2205 printk(KERN_CRIT "Free/Dirty block details\n");
2206 printk(KERN_CRIT "free_blocks=%lld\n",
2207 (long long) percpu_counter_sum(&sbi->s_freeblocks_counter));
2208 printk(KERN_CRIT "dirty_blocks=%lld\n",
2209 (long long) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2210 printk(KERN_CRIT "Block reservation details\n");
2211 printk(KERN_CRIT "i_reserved_data_blocks=%u\n",
2212 EXT4_I(inode)->i_reserved_data_blocks);
2213 printk(KERN_CRIT "i_reserved_meta_blocks=%u\n",
2214 EXT4_I(inode)->i_reserved_meta_blocks);
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002215 return;
2216}
2217
Theodore Ts'ob920c752009-05-14 00:54:29 -04002218/*
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002219 * mpage_da_map_and_submit - go through given space, map them
2220 * if necessary, and then submit them for I/O
Alex Tomas64769242008-07-11 19:27:31 -04002221 *
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002222 * @mpd - bh describing space
Alex Tomas64769242008-07-11 19:27:31 -04002223 *
2224 * The function skips space we know is already mapped to disk blocks.
2225 *
Alex Tomas64769242008-07-11 19:27:31 -04002226 */
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002227static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
Alex Tomas64769242008-07-11 19:27:31 -04002228{
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002229 int err, blks, get_blocks_flags;
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002230 struct ext4_map_blocks map, *mapp = NULL;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002231 sector_t next = mpd->b_blocknr;
2232 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
2233 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
2234 handle_t *handle = NULL;
Alex Tomas64769242008-07-11 19:27:31 -04002235
2236 /*
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002237 * If the blocks are mapped already, or we couldn't accumulate
2238 * any blocks, then proceed immediately to the submission stage.
Alex Tomas64769242008-07-11 19:27:31 -04002239 */
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002240 if ((mpd->b_size == 0) ||
2241 ((mpd->b_state & (1 << BH_Mapped)) &&
2242 !(mpd->b_state & (1 << BH_Delay)) &&
2243 !(mpd->b_state & (1 << BH_Unwritten))))
2244 goto submit_io;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002245
2246 handle = ext4_journal_current_handle();
2247 BUG_ON(!handle);
2248
Aneesh Kumar K.V79ffab32009-05-13 15:13:42 -04002249 /*
Eric Sandeen79e83032010-07-27 11:56:07 -04002250 * Call ext4_map_blocks() to allocate any delayed allocation
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002251 * blocks, or to convert an uninitialized extent to be
2252 * initialized (in the case where we have written into
2253 * one or more preallocated blocks).
2254 *
2255 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2256 * indicate that we are on the delayed allocation path. This
2257 * affects functions in many different parts of the allocation
2258 * call path. This flag exists primarily because we don't
Eric Sandeen79e83032010-07-27 11:56:07 -04002259 * want to change *many* call functions, so ext4_map_blocks()
Theodore Ts'of2321092011-01-10 12:12:36 -05002260 * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002261 * inode's allocation semaphore is taken.
2262 *
2263 * If the blocks in questions were delalloc blocks, set
2264 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2265 * variables are updated after the blocks have been allocated.
Aneesh Kumar K.V79ffab32009-05-13 15:13:42 -04002266 */
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002267 map.m_lblk = next;
2268 map.m_len = max_blocks;
Aneesh Kumar K.V1296cc82010-01-15 01:27:59 -05002269 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
Jiaying Zhang744692d2010-03-04 16:14:02 -05002270 if (ext4_should_dioread_nolock(mpd->inode))
2271 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002272 if (mpd->b_state & (1 << BH_Delay))
Aneesh Kumar K.V1296cc82010-01-15 01:27:59 -05002273 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
2274
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002275 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002276 if (blks < 0) {
Eric Sandeene3570632010-07-27 11:56:08 -04002277 struct super_block *sb = mpd->inode->i_sb;
2278
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002279 err = blks;
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002280 /*
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002281 * If get block returns EAGAIN or ENOSPC and there
Theodore Ts'o97498952011-02-26 14:08:01 -05002282 * appears to be free blocks we will just let
2283 * mpage_da_submit_io() unlock all of the pages.
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002284 */
2285 if (err == -EAGAIN)
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002286 goto submit_io;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002287
2288 if (err == -ENOSPC &&
Eric Sandeene3570632010-07-27 11:56:08 -04002289 ext4_count_free_blocks(sb)) {
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002290 mpd->retval = err;
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002291 goto submit_io;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002292 }
2293
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002294 /*
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002295 * get block failure will cause us to loop in
2296 * writepages, because a_ops->writepage won't be able
2297 * to make progress. The page will be redirtied by
2298 * writepage and writepages will again try to write
2299 * the same.
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002300 */
Eric Sandeene3570632010-07-27 11:56:08 -04002301 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
2302 ext4_msg(sb, KERN_CRIT,
2303 "delayed block allocation failed for inode %lu "
2304 "at logical offset %llu with max blocks %zd "
2305 "with error %d", mpd->inode->i_ino,
2306 (unsigned long long) next,
2307 mpd->b_size >> mpd->inode->i_blkbits, err);
2308 ext4_msg(sb, KERN_CRIT,
2309 "This should not happen!! Data will be lost\n");
2310 if (err == -ENOSPC)
2311 ext4_print_free_blocks(mpd->inode);
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04002312 }
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002313 /* invalidate all the pages */
Curt Wohlgemuthc7f59382011-02-26 12:27:52 -05002314 ext4_da_block_invalidatepages(mpd);
Curt Wohlgemuthe0fd9b92011-02-26 12:25:52 -05002315
2316 /* Mark this page range as having been completed */
2317 mpd->io_done = 1;
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002318 return;
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002319 }
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002320 BUG_ON(blks == 0);
2321
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002322 mapp = &map;
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002323 if (map.m_flags & EXT4_MAP_NEW) {
2324 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
2325 int i;
Alex Tomas64769242008-07-11 19:27:31 -04002326
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002327 for (i = 0; i < map.m_len; i++)
2328 unmap_underlying_metadata(bdev, map.m_pblk + i);
2329 }
Alex Tomas64769242008-07-11 19:27:31 -04002330
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002331 if (ext4_should_order_data(mpd->inode)) {
2332 err = ext4_jbd2_file_inode(handle, mpd->inode);
2333 if (err)
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002334 /* This only happens if the journal is aborted */
2335 return;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002336 }
2337
2338 /*
Jan Kara03f5d8b2009-06-09 00:17:05 -04002339 * Update on-disk size along with block allocation.
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002340 */
2341 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
2342 if (disksize > i_size_read(mpd->inode))
2343 disksize = i_size_read(mpd->inode);
2344 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
2345 ext4_update_i_disksize(mpd->inode, disksize);
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002346 err = ext4_mark_inode_dirty(handle, mpd->inode);
2347 if (err)
2348 ext4_error(mpd->inode->i_sb,
2349 "Failed to mark inode %lu dirty",
2350 mpd->inode->i_ino);
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002351 }
2352
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002353submit_io:
Theodore Ts'o1de3e3d2010-10-27 21:30:10 -04002354 mpage_da_submit_io(mpd, mapp);
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002355 mpd->io_done = 1;
Alex Tomas64769242008-07-11 19:27:31 -04002356}
2357
Aneesh Kumar K.Vbf068ee2008-08-19 22:16:43 -04002358#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2359 (1 << BH_Delay) | (1 << BH_Unwritten))
Alex Tomas64769242008-07-11 19:27:31 -04002360
2361/*
2362 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2363 *
2364 * @mpd->lbh - extent of blocks
2365 * @logical - logical number of the block in the file
2366 * @bh - bh of the block (used to access block's state)
2367 *
2368 * the function is used to collect contig. blocks in same state
2369 */
2370static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002371 sector_t logical, size_t b_size,
2372 unsigned long b_state)
Alex Tomas64769242008-07-11 19:27:31 -04002373{
Alex Tomas64769242008-07-11 19:27:31 -04002374 sector_t next;
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002375 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
Alex Tomas64769242008-07-11 19:27:31 -04002376
Eric Sandeenc445e3e2010-05-16 04:00:00 -04002377 /*
2378 * XXX Don't go larger than mballoc is willing to allocate
2379 * This is a stopgap solution. We eventually need to fold
2380 * mpage_da_submit_io() into this function and then call
Eric Sandeen79e83032010-07-27 11:56:07 -04002381 * ext4_map_blocks() multiple times in a loop
Eric Sandeenc445e3e2010-05-16 04:00:00 -04002382 */
2383 if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize)
2384 goto flush_it;
2385
Mingming Cao525f4ed2008-08-19 22:15:58 -04002386 /* check if thereserved journal credits might overflow */
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04002387 if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) {
Mingming Cao525f4ed2008-08-19 22:15:58 -04002388 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
2389 /*
2390 * With non-extent format we are limited by the journal
2391 * credit available. Total credit needed to insert
2392 * nrblocks contiguous blocks is dependent on the
2393 * nrblocks. So limit nrblocks.
2394 */
2395 goto flush_it;
2396 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
2397 EXT4_MAX_TRANS_DATA) {
2398 /*
2399 * Adding the new buffer_head would make it cross the
2400 * allowed limit for which we have journal credit
2401 * reserved. So limit the new bh->b_size
2402 */
2403 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
2404 mpd->inode->i_blkbits;
2405 /* we will do mpage_da_submit_io in the next loop */
2406 }
2407 }
Alex Tomas64769242008-07-11 19:27:31 -04002408 /*
2409 * First block in the extent
2410 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002411 if (mpd->b_size == 0) {
2412 mpd->b_blocknr = logical;
2413 mpd->b_size = b_size;
2414 mpd->b_state = b_state & BH_FLAGS;
Alex Tomas64769242008-07-11 19:27:31 -04002415 return;
2416 }
2417
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002418 next = mpd->b_blocknr + nrblocks;
Alex Tomas64769242008-07-11 19:27:31 -04002419 /*
2420 * Can we merge the block to our big extent?
2421 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002422 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
2423 mpd->b_size += b_size;
Alex Tomas64769242008-07-11 19:27:31 -04002424 return;
2425 }
2426
Mingming Cao525f4ed2008-08-19 22:15:58 -04002427flush_it:
Alex Tomas64769242008-07-11 19:27:31 -04002428 /*
2429 * We couldn't merge the block to our extent, so we
2430 * need to flush current extent and start new one
2431 */
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04002432 mpage_da_map_and_submit(mpd);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002433 return;
Alex Tomas64769242008-07-11 19:27:31 -04002434}
2435
Aneesh Kumar K.Vc364b222009-06-14 17:57:10 -04002436static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002437{
Aneesh Kumar K.Vc364b222009-06-14 17:57:10 -04002438 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002439}
2440
Alex Tomas64769242008-07-11 19:27:31 -04002441/*
Theodore Ts'ob920c752009-05-14 00:54:29 -04002442 * This is a special get_blocks_t callback which is used by
2443 * ext4_da_write_begin(). It will either return mapped block or
2444 * reserve space for a single block.
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002445 *
2446 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2447 * We also have b_blocknr = -1 and b_bdev initialized properly
2448 *
2449 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2450 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2451 * initialized properly.
Alex Tomas64769242008-07-11 19:27:31 -04002452 */
2453static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002454 struct buffer_head *bh, int create)
Alex Tomas64769242008-07-11 19:27:31 -04002455{
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002456 struct ext4_map_blocks map;
Alex Tomas64769242008-07-11 19:27:31 -04002457 int ret = 0;
Aneesh Kumar K.V33b98172009-05-12 14:40:37 -04002458 sector_t invalid_block = ~((sector_t) 0xffff);
2459
2460 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
2461 invalid_block = ~0;
Alex Tomas64769242008-07-11 19:27:31 -04002462
2463 BUG_ON(create == 0);
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002464 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
2465
2466 map.m_lblk = iblock;
2467 map.m_len = 1;
Alex Tomas64769242008-07-11 19:27:31 -04002468
2469 /*
2470 * first, we need to know whether the block is allocated already
2471 * preallocated blocks are unmapped but should treated
2472 * the same as allocated blocks.
2473 */
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002474 ret = ext4_map_blocks(NULL, inode, &map, 0);
2475 if (ret < 0)
2476 return ret;
2477 if (ret == 0) {
2478 if (buffer_delay(bh))
2479 return 0; /* Not sure this could or should happen */
Alex Tomas64769242008-07-11 19:27:31 -04002480 /*
Christoph Hellwigebdec242010-10-06 10:47:23 +02002481 * XXX: __block_write_begin() unmaps passed block, is it OK?
Alex Tomas64769242008-07-11 19:27:31 -04002482 */
Theodore Ts'o9d0be502010-01-01 02:41:30 -05002483 ret = ext4_da_reserve_space(inode, iblock);
Mingming Caod2a17632008-07-14 17:52:37 -04002484 if (ret)
2485 /* not enough space to reserve */
2486 return ret;
2487
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002488 map_bh(bh, inode->i_sb, invalid_block);
2489 set_buffer_new(bh);
2490 set_buffer_delay(bh);
2491 return 0;
Alex Tomas64769242008-07-11 19:27:31 -04002492 }
2493
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002494 map_bh(bh, inode->i_sb, map.m_pblk);
2495 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
2496
2497 if (buffer_unwritten(bh)) {
2498 /* A delayed write to unwritten bh should be marked
2499 * new and mapped. Mapped ensures that we don't do
2500 * get_block multiple times when we write to the same
2501 * offset and new ensures that we do proper zero out
2502 * for partial write.
2503 */
2504 set_buffer_new(bh);
Theodore Ts'oc8205632011-04-10 22:30:07 -04002505 set_buffer_mapped(bh);
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002506 }
2507 return 0;
Alex Tomas64769242008-07-11 19:27:31 -04002508}
Mingming Cao61628a32008-07-11 19:27:31 -04002509
Theodore Ts'ob920c752009-05-14 00:54:29 -04002510/*
2511 * This function is used as a standard get_block_t calback function
2512 * when there is no desire to allocate any blocks. It is used as a
Christoph Hellwigebdec242010-10-06 10:47:23 +02002513 * callback function for block_write_begin() and block_write_full_page().
Christoph Hellwig206f7ab2010-06-14 14:42:49 -04002514 * These functions should only try to map a single block at a time.
Theodore Ts'ob920c752009-05-14 00:54:29 -04002515 *
2516 * Since this function doesn't do block allocations even if the caller
2517 * requests it by passing in create=1, it is critically important that
2518 * any caller checks to make sure that any buffer heads are returned
2519 * by this function are either all already mapped or marked for
Christoph Hellwig206f7ab2010-06-14 14:42:49 -04002520 * delayed allocation before calling block_write_full_page(). Otherwise,
2521 * b_blocknr could be left unitialized, and the page write functions will
2522 * be taken by surprise.
Theodore Ts'ob920c752009-05-14 00:54:29 -04002523 */
2524static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002525 struct buffer_head *bh_result, int create)
2526{
Theodore Ts'oa2dc52b2009-05-12 13:51:29 -04002527 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
Theodore Ts'o2ed88682010-05-16 20:00:00 -04002528 return _ext4_get_block(inode, iblock, bh_result, 0);
Mingming Cao61628a32008-07-11 19:27:31 -04002529}
2530
Aneesh Kumar K.V62e086b2009-06-14 17:59:34 -04002531static int bget_one(handle_t *handle, struct buffer_head *bh)
2532{
2533 get_bh(bh);
2534 return 0;
2535}
2536
2537static int bput_one(handle_t *handle, struct buffer_head *bh)
2538{
2539 put_bh(bh);
2540 return 0;
2541}
2542
2543static int __ext4_journalled_writepage(struct page *page,
Aneesh Kumar K.V62e086b2009-06-14 17:59:34 -04002544 unsigned int len)
2545{
2546 struct address_space *mapping = page->mapping;
2547 struct inode *inode = mapping->host;
2548 struct buffer_head *page_bufs;
2549 handle_t *handle = NULL;
2550 int ret = 0;
2551 int err;
2552
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002553 ClearPageChecked(page);
Aneesh Kumar K.V62e086b2009-06-14 17:59:34 -04002554 page_bufs = page_buffers(page);
2555 BUG_ON(!page_bufs);
2556 walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
2557 /* As soon as we unlock the page, it can go away, but we have
2558 * references to buffers so we are safe */
2559 unlock_page(page);
2560
2561 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
2562 if (IS_ERR(handle)) {
2563 ret = PTR_ERR(handle);
2564 goto out;
2565 }
2566
2567 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2568 do_journal_get_write_access);
2569
2570 err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2571 write_end_fn);
2572 if (ret == 0)
2573 ret = err;
2574 err = ext4_journal_stop(handle);
2575 if (!ret)
2576 ret = err;
2577
2578 walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05002579 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
Aneesh Kumar K.V62e086b2009-06-14 17:59:34 -04002580out:
2581 return ret;
2582}
2583
Jiaying Zhang744692d2010-03-04 16:14:02 -05002584static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
2585static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
2586
Mingming Cao61628a32008-07-11 19:27:31 -04002587/*
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002588 * Note that we don't need to start a transaction unless we're journaling data
2589 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2590 * need to file the inode to the transaction's list in ordered mode because if
2591 * we are writing back data added by write(), the inode is already there and if
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002592 * we are writing back data modified via mmap(), no one guarantees in which
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002593 * transaction the data will hit the disk. In case we are journaling data, we
2594 * cannot start transaction directly because transaction start ranks above page
2595 * lock so we have to do some magic.
2596 *
Theodore Ts'ob920c752009-05-14 00:54:29 -04002597 * This function can get called via...
2598 * - ext4_da_writepages after taking page lock (have journal handle)
2599 * - journal_submit_inode_data_buffers (no journal handle)
2600 * - shrink_page_list via pdflush (no journal handle)
2601 * - grab_page_cache when doing write_begin (have journal handle)
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002602 *
2603 * We don't do any block allocation in this function. If we have page with
2604 * multiple blocks we need to write those buffer_heads that are mapped. This
2605 * is important for mmaped based write. So if we do with blocksize 1K
2606 * truncate(f, 1024);
2607 * a = mmap(f, 0, 4096);
2608 * a[0] = 'a';
2609 * truncate(f, 4096);
2610 * we have in the page first buffer_head mapped via page_mkwrite call back
2611 * but other bufer_heads would be unmapped but dirty(dirty done via the
2612 * do_wp_page). So writepage should write the first block. If we modify
2613 * the mmap area beyond 1024 we will again get a page_fault and the
2614 * page_mkwrite callback will do the block allocation and mark the
2615 * buffer_heads mapped.
2616 *
2617 * We redirty the page if we have any buffer_heads that is either delay or
2618 * unwritten in the page.
2619 *
2620 * We can get recursively called as show below.
2621 *
2622 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2623 * ext4_writepage()
2624 *
2625 * But since we don't do any block allocation we should not deadlock.
2626 * Page also have the dirty flag cleared so we don't get recurive page_lock.
Mingming Cao61628a32008-07-11 19:27:31 -04002627 */
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002628static int ext4_writepage(struct page *page,
Aneesh Kumar K.V62e086b2009-06-14 17:59:34 -04002629 struct writeback_control *wbc)
Alex Tomas64769242008-07-11 19:27:31 -04002630{
Theodore Ts'oa42afc52010-10-27 21:30:09 -04002631 int ret = 0, commit_write = 0;
Mingming Cao61628a32008-07-11 19:27:31 -04002632 loff_t size;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002633 unsigned int len;
Jiaying Zhang744692d2010-03-04 16:14:02 -05002634 struct buffer_head *page_bufs = NULL;
Mingming Cao61628a32008-07-11 19:27:31 -04002635 struct inode *inode = page->mapping->host;
Alex Tomas64769242008-07-11 19:27:31 -04002636
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002637 trace_ext4_writepage(inode, page);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002638 size = i_size_read(inode);
2639 if (page->index == size >> PAGE_CACHE_SHIFT)
2640 len = size & ~PAGE_CACHE_MASK;
2641 else
2642 len = PAGE_CACHE_SIZE;
Alex Tomas64769242008-07-11 19:27:31 -04002643
Theodore Ts'oa42afc52010-10-27 21:30:09 -04002644 /*
2645 * If the page does not have buffers (for whatever reason),
Theodore Ts'oa107e5a2010-10-27 23:44:47 -04002646 * try to create them using __block_write_begin. If this
Theodore Ts'oa42afc52010-10-27 21:30:09 -04002647 * fails, redirty the page and move on.
2648 */
Theodore Ts'ob1142e82010-10-28 17:33:57 -04002649 if (!page_has_buffers(page)) {
Theodore Ts'oa107e5a2010-10-27 23:44:47 -04002650 if (__block_write_begin(page, 0, len,
Theodore Ts'oa42afc52010-10-27 21:30:09 -04002651 noalloc_get_block_write)) {
2652 redirty_page:
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002653 redirty_page_for_writepage(wbc, page);
2654 unlock_page(page);
2655 return 0;
2656 }
Theodore Ts'oa42afc52010-10-27 21:30:09 -04002657 commit_write = 1;
2658 }
2659 page_bufs = page_buffers(page);
2660 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2661 ext4_bh_delay_or_unwritten)) {
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002662 /*
Theodore Ts'ob1142e82010-10-28 17:33:57 -04002663 * We don't want to do block allocation, so redirty
2664 * the page and return. We may reach here when we do
2665 * a journal commit via journal_submit_inode_data_buffers.
2666 * We can also reach here via shrink_page_list
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002667 */
Theodore Ts'oa42afc52010-10-27 21:30:09 -04002668 goto redirty_page;
2669 }
2670 if (commit_write)
Aneesh Kumar K.Ved9b3e32008-11-07 09:06:45 -05002671 /* now mark the buffer_heads as dirty and uptodate */
Aneesh Kumar K.Vb767e782009-06-04 08:06:06 -04002672 block_commit_write(page, 0, len);
Alex Tomas64769242008-07-11 19:27:31 -04002673
Theodore Ts'ocb20d512010-10-27 21:30:09 -04002674 if (PageChecked(page) && ext4_should_journal_data(inode))
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002675 /*
2676 * It's mmapped pagecache. Add buffers and journal it. There
2677 * doesn't seem much point in redirtying the page here.
2678 */
Wu Fengguang3f0ca302009-11-24 11:15:44 -05002679 return __ext4_journalled_writepage(page, len);
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002680
Theodore Ts'oa42afc52010-10-27 21:30:09 -04002681 if (buffer_uninit(page_bufs)) {
Jiaying Zhang744692d2010-03-04 16:14:02 -05002682 ext4_set_bh_endio(page_bufs, inode);
2683 ret = block_write_full_page_endio(page, noalloc_get_block_write,
2684 wbc, ext4_end_io_buffer_write);
2685 } else
Theodore Ts'ob920c752009-05-14 00:54:29 -04002686 ret = block_write_full_page(page, noalloc_get_block_write,
2687 wbc);
Alex Tomas64769242008-07-11 19:27:31 -04002688
Alex Tomas64769242008-07-11 19:27:31 -04002689 return ret;
2690}
2691
Mingming Cao61628a32008-07-11 19:27:31 -04002692/*
Mingming Cao525f4ed2008-08-19 22:15:58 -04002693 * This is called via ext4_da_writepages() to
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002694 * calculate the total number of credits to reserve to fit
Mingming Cao525f4ed2008-08-19 22:15:58 -04002695 * a single extent allocation into a single transaction,
2696 * ext4_da_writpeages() will loop calling this before
2697 * the block allocation.
Mingming Cao61628a32008-07-11 19:27:31 -04002698 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04002699
2700static int ext4_da_writepages_trans_blocks(struct inode *inode)
2701{
2702 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2703
2704 /*
2705 * With non-extent format the journal credit needed to
2706 * insert nrblocks contiguous block is dependent on
2707 * number of contiguous block. So we will limit
2708 * number of contiguous block to a sane value
2709 */
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04002710 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
Mingming Cao525f4ed2008-08-19 22:15:58 -04002711 (max_blocks > EXT4_MAX_TRANS_DATA))
2712 max_blocks = EXT4_MAX_TRANS_DATA;
2713
2714 return ext4_chunk_trans_blocks(inode, max_blocks);
2715}
Mingming Cao61628a32008-07-11 19:27:31 -04002716
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002717/*
2718 * write_cache_pages_da - walk the list of dirty pages of the given
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002719 * address space and accumulate pages that need writing, and call
Theodore Ts'o168fc022011-02-26 14:09:20 -05002720 * mpage_da_map_and_submit to map a single contiguous memory region
2721 * and then write them.
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002722 */
2723static int write_cache_pages_da(struct address_space *mapping,
2724 struct writeback_control *wbc,
Eric Sandeen72f84e62010-10-27 21:30:13 -04002725 struct mpage_da_data *mpd,
2726 pgoff_t *done_index)
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002727{
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002728 struct buffer_head *bh, *head;
Theodore Ts'o168fc022011-02-26 14:09:20 -05002729 struct inode *inode = mapping->host;
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002730 struct pagevec pvec;
2731 unsigned int nr_pages;
2732 sector_t logical;
2733 pgoff_t index, end;
2734 long nr_to_write = wbc->nr_to_write;
2735 int i, tag, ret = 0;
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002736
Theodore Ts'o168fc022011-02-26 14:09:20 -05002737 memset(mpd, 0, sizeof(struct mpage_da_data));
2738 mpd->wbc = wbc;
2739 mpd->inode = inode;
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002740 pagevec_init(&pvec, 0);
2741 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2742 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2743
Eric Sandeen5b41d922010-10-27 21:30:13 -04002744 if (wbc->sync_mode == WB_SYNC_ALL)
2745 tag = PAGECACHE_TAG_TOWRITE;
2746 else
2747 tag = PAGECACHE_TAG_DIRTY;
2748
Eric Sandeen72f84e62010-10-27 21:30:13 -04002749 *done_index = index;
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002750 while (index <= end) {
Eric Sandeen5b41d922010-10-27 21:30:13 -04002751 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002752 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2753 if (nr_pages == 0)
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002754 return 0;
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002755
2756 for (i = 0; i < nr_pages; i++) {
2757 struct page *page = pvec.pages[i];
2758
2759 /*
2760 * At this point, the page may be truncated or
2761 * invalidated (changing page->mapping to NULL), or
2762 * even swizzled back from swapper_space to tmpfs file
2763 * mapping. However, page->index will not change
2764 * because we have a reference on the page.
2765 */
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002766 if (page->index > end)
2767 goto out;
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002768
Eric Sandeen72f84e62010-10-27 21:30:13 -04002769 *done_index = page->index + 1;
2770
Theodore Ts'o78aaced2011-02-26 14:09:14 -05002771 /*
2772 * If we can't merge this page, and we have
2773 * accumulated an contiguous region, write it
2774 */
2775 if ((mpd->next_page != page->index) &&
2776 (mpd->next_page != mpd->first_page)) {
2777 mpage_da_map_and_submit(mpd);
2778 goto ret_extent_tail;
2779 }
2780
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002781 lock_page(page);
2782
2783 /*
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002784 * If the page is no longer dirty, or its
2785 * mapping no longer corresponds to inode we
2786 * are writing (which means it has been
2787 * truncated or invalidated), or the page is
2788 * already under writeback and we are not
2789 * doing a data integrity writeback, skip the page
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002790 */
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002791 if (!PageDirty(page) ||
2792 (PageWriteback(page) &&
2793 (wbc->sync_mode == WB_SYNC_NONE)) ||
2794 unlikely(page->mapping != mapping)) {
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002795 unlock_page(page);
2796 continue;
2797 }
2798
Darrick J. Wong7cb1a532011-05-18 13:53:20 -04002799 wait_on_page_writeback(page);
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002800 BUG_ON(PageWriteback(page));
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002801
Theodore Ts'o168fc022011-02-26 14:09:20 -05002802 if (mpd->next_page != page->index)
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002803 mpd->first_page = page->index;
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002804 mpd->next_page = page->index + 1;
2805 logical = (sector_t) page->index <<
2806 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2807
2808 if (!page_has_buffers(page)) {
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002809 mpage_add_bh_to_extent(mpd, logical,
2810 PAGE_CACHE_SIZE,
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002811 (1 << BH_Dirty) | (1 << BH_Uptodate));
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002812 if (mpd->io_done)
2813 goto ret_extent_tail;
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002814 } else {
2815 /*
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002816 * Page with regular buffer heads,
2817 * just add all dirty ones
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002818 */
2819 head = page_buffers(page);
2820 bh = head;
2821 do {
2822 BUG_ON(buffer_locked(bh));
2823 /*
2824 * We need to try to allocate
2825 * unmapped blocks in the same page.
2826 * Otherwise we won't make progress
2827 * with the page in ext4_writepage
2828 */
2829 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2830 mpage_add_bh_to_extent(mpd, logical,
2831 bh->b_size,
2832 bh->b_state);
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002833 if (mpd->io_done)
2834 goto ret_extent_tail;
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002835 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2836 /*
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002837 * mapped dirty buffer. We need
2838 * to update the b_state
2839 * because we look at b_state
2840 * in mpage_da_map_blocks. We
2841 * don't update b_size because
2842 * if we find an unmapped
2843 * buffer_head later we need to
2844 * use the b_state flag of that
2845 * buffer_head.
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002846 */
2847 if (mpd->b_size == 0)
2848 mpd->b_state = bh->b_state & BH_FLAGS;
2849 }
2850 logical++;
2851 } while ((bh = bh->b_this_page) != head);
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002852 }
2853
2854 if (nr_to_write > 0) {
2855 nr_to_write--;
2856 if (nr_to_write == 0 &&
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002857 wbc->sync_mode == WB_SYNC_NONE)
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002858 /*
2859 * We stop writing back only if we are
2860 * not doing integrity sync. In case of
2861 * integrity sync we have to keep going
2862 * because someone may be concurrently
2863 * dirtying pages, and we might have
2864 * synced a lot of newly appeared dirty
2865 * pages, but have not synced all of the
2866 * old dirty pages.
2867 */
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002868 goto out;
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002869 }
2870 }
2871 pagevec_release(&pvec);
2872 cond_resched();
2873 }
Theodore Ts'o4f01b022011-02-26 14:07:37 -05002874 return 0;
2875ret_extent_tail:
2876 ret = MPAGE_DA_EXTENT_TAIL;
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05002877out:
2878 pagevec_release(&pvec);
2879 cond_resched();
Theodore Ts'o8e48dcf2010-05-16 18:00:00 -04002880 return ret;
2881}
2882
2883
Alex Tomas64769242008-07-11 19:27:31 -04002884static int ext4_da_writepages(struct address_space *mapping,
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002885 struct writeback_control *wbc)
Alex Tomas64769242008-07-11 19:27:31 -04002886{
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002887 pgoff_t index;
2888 int range_whole = 0;
Mingming Cao61628a32008-07-11 19:27:31 -04002889 handle_t *handle = NULL;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002890 struct mpage_da_data mpd;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002891 struct inode *inode = mapping->host;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002892 int pages_written = 0;
Theodore Ts'o55138e02009-09-29 13:31:31 -04002893 unsigned int max_pages;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002894 int range_cyclic, cycled = 1, io_done = 0;
Theodore Ts'o55138e02009-09-29 13:31:31 -04002895 int needed_blocks, ret = 0;
2896 long desired_nr_to_write, nr_to_writebump = 0;
Theodore Ts'ode89de62009-08-31 17:00:59 -04002897 loff_t range_start = wbc->range_start;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002898 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
Eric Sandeen72f84e62010-10-27 21:30:13 -04002899 pgoff_t done_index = 0;
Eric Sandeen5b41d922010-10-27 21:30:13 -04002900 pgoff_t end;
Mingming Cao61628a32008-07-11 19:27:31 -04002901
Theodore Ts'o9bffad12009-06-17 11:48:11 -04002902 trace_ext4_da_writepages(inode, wbc);
Theodore Ts'oba80b102009-01-03 20:03:21 -05002903
Mingming Cao61628a32008-07-11 19:27:31 -04002904 /*
2905 * No pages to write? This is mainly a kludge to avoid starting
2906 * a transaction for special inodes like journal inode on last iput()
2907 * because that could violate lock ordering on umount
2908 */
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002909 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
Mingming Cao61628a32008-07-11 19:27:31 -04002910 return 0;
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002911
2912 /*
2913 * If the filesystem has aborted, it is read-only, so return
2914 * right away instead of dumping stack traces later on that
2915 * will obscure the real source of the problem. We test
Theodore Ts'o4ab2f152009-06-13 10:09:36 -04002916 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002917 * the latter could be true if the filesystem is mounted
2918 * read-only, and in that case, ext4_da_writepages should
2919 * *never* be called, so if that ever happens, we would want
2920 * the stack trace.
2921 */
Theodore Ts'o4ab2f152009-06-13 10:09:36 -04002922 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002923 return -EROFS;
2924
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002925 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2926 range_whole = 1;
Mingming Cao61628a32008-07-11 19:27:31 -04002927
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002928 range_cyclic = wbc->range_cyclic;
2929 if (wbc->range_cyclic) {
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002930 index = mapping->writeback_index;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002931 if (index)
2932 cycled = 0;
2933 wbc->range_start = index << PAGE_CACHE_SHIFT;
2934 wbc->range_end = LLONG_MAX;
2935 wbc->range_cyclic = 0;
Eric Sandeen5b41d922010-10-27 21:30:13 -04002936 end = -1;
2937 } else {
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002938 index = wbc->range_start >> PAGE_CACHE_SHIFT;
Eric Sandeen5b41d922010-10-27 21:30:13 -04002939 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2940 }
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002941
Theodore Ts'o55138e02009-09-29 13:31:31 -04002942 /*
2943 * This works around two forms of stupidity. The first is in
2944 * the writeback code, which caps the maximum number of pages
2945 * written to be 1024 pages. This is wrong on multiple
2946 * levels; different architectues have a different page size,
2947 * which changes the maximum amount of data which gets
2948 * written. Secondly, 4 megabytes is way too small. XFS
2949 * forces this value to be 16 megabytes by multiplying
2950 * nr_to_write parameter by four, and then relies on its
2951 * allocator to allocate larger extents to make them
2952 * contiguous. Unfortunately this brings us to the second
2953 * stupidity, which is that ext4's mballoc code only allocates
2954 * at most 2048 blocks. So we force contiguous writes up to
2955 * the number of dirty blocks in the inode, or
2956 * sbi->max_writeback_mb_bump whichever is smaller.
2957 */
2958 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
Eric Sandeenb443e732010-10-27 21:30:03 -04002959 if (!range_cyclic && range_whole) {
2960 if (wbc->nr_to_write == LONG_MAX)
2961 desired_nr_to_write = wbc->nr_to_write;
2962 else
2963 desired_nr_to_write = wbc->nr_to_write * 8;
2964 } else
Theodore Ts'o55138e02009-09-29 13:31:31 -04002965 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
2966 max_pages);
2967 if (desired_nr_to_write > max_pages)
2968 desired_nr_to_write = max_pages;
2969
2970 if (wbc->nr_to_write < desired_nr_to_write) {
2971 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
2972 wbc->nr_to_write = desired_nr_to_write;
2973 }
2974
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002975retry:
Eric Sandeen5b41d922010-10-27 21:30:13 -04002976 if (wbc->sync_mode == WB_SYNC_ALL)
2977 tag_pages_for_writeback(mapping, index, end);
2978
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002979 while (!ret && wbc->nr_to_write > 0) {
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002980
2981 /*
2982 * we insert one extent at a time. So we need
2983 * credit needed for single extent allocation.
2984 * journalled mode is currently not supported
2985 * by delalloc
2986 */
2987 BUG_ON(ext4_should_journal_data(inode));
Mingming Cao525f4ed2008-08-19 22:15:58 -04002988 needed_blocks = ext4_da_writepages_trans_blocks(inode);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002989
Mingming Cao61628a32008-07-11 19:27:31 -04002990 /* start a new transaction*/
2991 handle = ext4_journal_start(inode, needed_blocks);
2992 if (IS_ERR(handle)) {
2993 ret = PTR_ERR(handle);
Theodore Ts'o16939182009-09-26 17:43:59 -04002994 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
Curt Wohlgemuthfbe845d2010-05-16 13:00:00 -04002995 "%ld pages, ino %lu; err %d", __func__,
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002996 wbc->nr_to_write, inode->i_ino, ret);
Mingming Cao61628a32008-07-11 19:27:31 -04002997 goto out_writepages;
2998 }
Theodore Ts'of63e6002009-02-23 16:42:39 -05002999
3000 /*
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05003001 * Now call write_cache_pages_da() to find the next
Theodore Ts'of63e6002009-02-23 16:42:39 -05003002 * contiguous region of logical blocks that need
Theodore Ts'o8eb9e5c2011-02-26 14:07:31 -05003003 * blocks to be allocated by ext4 and submit them.
Theodore Ts'of63e6002009-02-23 16:42:39 -05003004 */
Eric Sandeen72f84e62010-10-27 21:30:13 -04003005 ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index);
Theodore Ts'of63e6002009-02-23 16:42:39 -05003006 /*
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02003007 * If we have a contiguous extent of pages and we
Theodore Ts'of63e6002009-02-23 16:42:39 -05003008 * haven't done the I/O yet, map the blocks and submit
3009 * them for I/O.
3010 */
3011 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
Theodore Ts'o5a87b7a2010-10-27 21:30:09 -04003012 mpage_da_map_and_submit(&mpd);
Theodore Ts'of63e6002009-02-23 16:42:39 -05003013 ret = MPAGE_DA_EXTENT_TAIL;
3014 }
Theodore Ts'ob3a3ca82009-08-31 23:13:11 -04003015 trace_ext4_da_write_pages(inode, &mpd);
Theodore Ts'of63e6002009-02-23 16:42:39 -05003016 wbc->nr_to_write -= mpd.pages_written;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04003017
Mingming Cao61628a32008-07-11 19:27:31 -04003018 ext4_journal_stop(handle);
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04003019
Eric Sandeen8f64b322009-02-26 00:57:35 -05003020 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04003021 /* commit the transaction which would
3022 * free blocks released in the transaction
3023 * and try again
3024 */
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04003025 jbd2_journal_force_commit_nested(sbi->s_journal);
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04003026 ret = 0;
3027 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04003028 /*
3029 * got one extent now try with
3030 * rest of the pages
3031 */
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04003032 pages_written += mpd.pages_written;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04003033 ret = 0;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05003034 io_done = 1;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04003035 } else if (wbc->nr_to_write)
Mingming Cao61628a32008-07-11 19:27:31 -04003036 /*
3037 * There is no more writeout needed
3038 * or we requested for a noblocking writeout
3039 * and we found the device congested
3040 */
Mingming Cao61628a32008-07-11 19:27:31 -04003041 break;
Mingming Cao61628a32008-07-11 19:27:31 -04003042 }
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05003043 if (!io_done && !cycled) {
3044 cycled = 1;
3045 index = 0;
3046 wbc->range_start = index << PAGE_CACHE_SHIFT;
3047 wbc->range_end = mapping->writeback_index - 1;
3048 goto retry;
3049 }
Mingming Cao61628a32008-07-11 19:27:31 -04003050
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04003051 /* Update index */
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05003052 wbc->range_cyclic = range_cyclic;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04003053 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
3054 /*
3055 * set the writeback_index so that range_cyclic
3056 * mode will write it back later
3057 */
Eric Sandeen72f84e62010-10-27 21:30:13 -04003058 mapping->writeback_index = done_index;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04003059
Mingming Cao61628a32008-07-11 19:27:31 -04003060out_writepages:
Richard Kennedy2faf2e12009-12-25 15:46:07 -05003061 wbc->nr_to_write -= nr_to_writebump;
Theodore Ts'ode89de62009-08-31 17:00:59 -04003062 wbc->range_start = range_start;
Theodore Ts'o9bffad12009-06-17 11:48:11 -04003063 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
Mingming Cao61628a32008-07-11 19:27:31 -04003064 return ret;
Alex Tomas64769242008-07-11 19:27:31 -04003065}
3066
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04003067#define FALL_BACK_TO_NONDELALLOC 1
3068static int ext4_nonda_switch(struct super_block *sb)
3069{
3070 s64 free_blocks, dirty_blocks;
3071 struct ext4_sb_info *sbi = EXT4_SB(sb);
3072
3073 /*
3074 * switch to non delalloc mode if we are running low
3075 * on free block. The free block accounting via percpu
Eric Dumazet179f7eb2009-01-06 14:41:04 -08003076 * counters can get slightly wrong with percpu_counter_batch getting
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04003077 * accumulated on each CPU without updating global counters
3078 * Delalloc need an accurate free block accounting. So switch
3079 * to non delalloc when we are near to error range.
3080 */
3081 free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
3082 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter);
3083 if (2 * free_blocks < 3 * dirty_blocks ||
3084 free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) {
3085 /*
Eric Sandeenc8afb442009-12-23 07:58:12 -05003086 * free block count is less than 150% of dirty blocks
3087 * or free blocks is less than watermark
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04003088 */
3089 return 1;
3090 }
Eric Sandeenc8afb442009-12-23 07:58:12 -05003091 /*
3092 * Even if we don't switch but are nearing capacity,
3093 * start pushing delalloc when 1/2 of free blocks are dirty.
3094 */
3095 if (free_blocks < 2 * dirty_blocks)
3096 writeback_inodes_sb_if_idle(sb);
3097
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04003098 return 0;
3099}
3100
Alex Tomas64769242008-07-11 19:27:31 -04003101static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003102 loff_t pos, unsigned len, unsigned flags,
3103 struct page **pagep, void **fsdata)
Alex Tomas64769242008-07-11 19:27:31 -04003104{
Eric Sandeen72b8ab92010-05-16 11:00:00 -04003105 int ret, retries = 0;
Alex Tomas64769242008-07-11 19:27:31 -04003106 struct page *page;
3107 pgoff_t index;
Alex Tomas64769242008-07-11 19:27:31 -04003108 struct inode *inode = mapping->host;
3109 handle_t *handle;
3110
3111 index = pos >> PAGE_CACHE_SHIFT;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04003112
3113 if (ext4_nonda_switch(inode->i_sb)) {
3114 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
3115 return ext4_write_begin(file, mapping, pos,
3116 len, flags, pagep, fsdata);
3117 }
3118 *fsdata = (void *)0;
Theodore Ts'o9bffad12009-06-17 11:48:11 -04003119 trace_ext4_da_write_begin(inode, pos, len, flags);
Mingming Caod2a17632008-07-14 17:52:37 -04003120retry:
Alex Tomas64769242008-07-11 19:27:31 -04003121 /*
3122 * With delayed allocation, we don't log the i_disksize update
3123 * if there is delayed block allocation. But we still need
3124 * to journalling the i_disksize update if writes to the end
3125 * of file which has an already mapped buffer.
3126 */
3127 handle = ext4_journal_start(inode, 1);
3128 if (IS_ERR(handle)) {
3129 ret = PTR_ERR(handle);
3130 goto out;
3131 }
Jan Karaebd36102009-02-22 21:09:59 -05003132 /* We cannot recurse into the filesystem as the transaction is already
3133 * started */
3134 flags |= AOP_FLAG_NOFS;
Alex Tomas64769242008-07-11 19:27:31 -04003135
Nick Piggin54566b22009-01-04 12:00:53 -08003136 page = grab_cache_page_write_begin(mapping, index, flags);
Eric Sandeend5a0d4f2008-08-02 18:51:06 -04003137 if (!page) {
3138 ext4_journal_stop(handle);
3139 ret = -ENOMEM;
3140 goto out;
3141 }
Alex Tomas64769242008-07-11 19:27:31 -04003142 *pagep = page;
3143
Christoph Hellwig6e1db882010-06-04 11:29:57 +02003144 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
Alex Tomas64769242008-07-11 19:27:31 -04003145 if (ret < 0) {
3146 unlock_page(page);
3147 ext4_journal_stop(handle);
3148 page_cache_release(page);
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04003149 /*
3150 * block_write_begin may have instantiated a few blocks
3151 * outside i_size. Trim these off again. Don't need
3152 * i_size_read because we hold i_mutex.
3153 */
3154 if (pos + len > inode->i_size)
Jan Karab9a42072009-12-08 21:24:33 -05003155 ext4_truncate_failed_write(inode);
Alex Tomas64769242008-07-11 19:27:31 -04003156 }
3157
Mingming Caod2a17632008-07-14 17:52:37 -04003158 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
3159 goto retry;
Alex Tomas64769242008-07-11 19:27:31 -04003160out:
3161 return ret;
3162}
3163
Mingming Cao632eaea2008-07-11 19:27:31 -04003164/*
3165 * Check if we should update i_disksize
3166 * when write to the end of file but not require block allocation
3167 */
3168static int ext4_da_should_update_i_disksize(struct page *page,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003169 unsigned long offset)
Mingming Cao632eaea2008-07-11 19:27:31 -04003170{
3171 struct buffer_head *bh;
3172 struct inode *inode = page->mapping->host;
3173 unsigned int idx;
3174 int i;
3175
3176 bh = page_buffers(page);
3177 idx = offset >> inode->i_blkbits;
3178
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003179 for (i = 0; i < idx; i++)
Mingming Cao632eaea2008-07-11 19:27:31 -04003180 bh = bh->b_this_page;
3181
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04003182 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
Mingming Cao632eaea2008-07-11 19:27:31 -04003183 return 0;
3184 return 1;
3185}
3186
Alex Tomas64769242008-07-11 19:27:31 -04003187static int ext4_da_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003188 struct address_space *mapping,
3189 loff_t pos, unsigned len, unsigned copied,
3190 struct page *page, void *fsdata)
Alex Tomas64769242008-07-11 19:27:31 -04003191{
3192 struct inode *inode = mapping->host;
3193 int ret = 0, ret2;
3194 handle_t *handle = ext4_journal_current_handle();
3195 loff_t new_i_size;
Mingming Cao632eaea2008-07-11 19:27:31 -04003196 unsigned long start, end;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04003197 int write_mode = (int)(unsigned long)fsdata;
3198
3199 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
3200 if (ext4_should_order_data(inode)) {
3201 return ext4_ordered_write_end(file, mapping, pos,
3202 len, copied, page, fsdata);
3203 } else if (ext4_should_writeback_data(inode)) {
3204 return ext4_writeback_write_end(file, mapping, pos,
3205 len, copied, page, fsdata);
3206 } else {
3207 BUG();
3208 }
3209 }
Mingming Cao632eaea2008-07-11 19:27:31 -04003210
Theodore Ts'o9bffad12009-06-17 11:48:11 -04003211 trace_ext4_da_write_end(inode, pos, len, copied);
Mingming Cao632eaea2008-07-11 19:27:31 -04003212 start = pos & (PAGE_CACHE_SIZE - 1);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003213 end = start + copied - 1;
Alex Tomas64769242008-07-11 19:27:31 -04003214
3215 /*
3216 * generic_write_end() will run mark_inode_dirty() if i_size
3217 * changes. So let's piggyback the i_disksize mark_inode_dirty
3218 * into that.
3219 */
3220
3221 new_i_size = pos + copied;
Mingming Cao632eaea2008-07-11 19:27:31 -04003222 if (new_i_size > EXT4_I(inode)->i_disksize) {
3223 if (ext4_da_should_update_i_disksize(page, end)) {
3224 down_write(&EXT4_I(inode)->i_data_sem);
3225 if (new_i_size > EXT4_I(inode)->i_disksize) {
3226 /*
3227 * Updating i_disksize when extending file
3228 * without needing block allocation
3229 */
3230 if (ext4_should_order_data(inode))
3231 ret = ext4_jbd2_file_inode(handle,
3232 inode);
Alex Tomas64769242008-07-11 19:27:31 -04003233
Mingming Cao632eaea2008-07-11 19:27:31 -04003234 EXT4_I(inode)->i_disksize = new_i_size;
3235 }
3236 up_write(&EXT4_I(inode)->i_data_sem);
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04003237 /* We need to mark inode dirty even if
3238 * new_i_size is less that inode->i_size
3239 * bu greater than i_disksize.(hint delalloc)
3240 */
3241 ext4_mark_inode_dirty(handle, inode);
Alex Tomas64769242008-07-11 19:27:31 -04003242 }
Mingming Cao632eaea2008-07-11 19:27:31 -04003243 }
Alex Tomas64769242008-07-11 19:27:31 -04003244 ret2 = generic_write_end(file, mapping, pos, len, copied,
3245 page, fsdata);
3246 copied = ret2;
3247 if (ret2 < 0)
3248 ret = ret2;
3249 ret2 = ext4_journal_stop(handle);
3250 if (!ret)
3251 ret = ret2;
3252
3253 return ret ? ret : copied;
3254}
3255
3256static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
3257{
Alex Tomas64769242008-07-11 19:27:31 -04003258 /*
3259 * Drop reserved blocks
3260 */
3261 BUG_ON(!PageLocked(page));
3262 if (!page_has_buffers(page))
3263 goto out;
3264
Mingming Caod2a17632008-07-14 17:52:37 -04003265 ext4_da_page_release_reservation(page, offset);
Alex Tomas64769242008-07-11 19:27:31 -04003266
3267out:
3268 ext4_invalidatepage(page, offset);
3269
3270 return;
3271}
3272
Theodore Ts'occd25062009-02-26 01:04:07 -05003273/*
3274 * Force all delayed allocation blocks to be allocated for a given inode.
3275 */
3276int ext4_alloc_da_blocks(struct inode *inode)
3277{
Theodore Ts'ofb40ba02009-09-16 19:30:40 -04003278 trace_ext4_alloc_da_blocks(inode);
3279
Theodore Ts'occd25062009-02-26 01:04:07 -05003280 if (!EXT4_I(inode)->i_reserved_data_blocks &&
3281 !EXT4_I(inode)->i_reserved_meta_blocks)
3282 return 0;
3283
3284 /*
3285 * We do something simple for now. The filemap_flush() will
3286 * also start triggering a write of the data blocks, which is
3287 * not strictly speaking necessary (and for users of
3288 * laptop_mode, not even desirable). However, to do otherwise
3289 * would require replicating code paths in:
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003290 *
Theodore Ts'occd25062009-02-26 01:04:07 -05003291 * ext4_da_writepages() ->
3292 * write_cache_pages() ---> (via passed in callback function)
3293 * __mpage_da_writepage() -->
3294 * mpage_add_bh_to_extent()
3295 * mpage_da_map_blocks()
3296 *
3297 * The problem is that write_cache_pages(), located in
3298 * mm/page-writeback.c, marks pages clean in preparation for
3299 * doing I/O, which is not desirable if we're not planning on
3300 * doing I/O at all.
3301 *
3302 * We could call write_cache_pages(), and then redirty all of
Wu Fengguang380cf092010-11-11 19:23:29 +08003303 * the pages by calling redirty_page_for_writepage() but that
Theodore Ts'occd25062009-02-26 01:04:07 -05003304 * would be ugly in the extreme. So instead we would need to
3305 * replicate parts of the code in the above functions,
Lucas De Marchi25985ed2011-03-30 22:57:33 -03003306 * simplifying them because we wouldn't actually intend to
Theodore Ts'occd25062009-02-26 01:04:07 -05003307 * write out the pages, but rather only collect contiguous
3308 * logical block extents, call the multi-block allocator, and
3309 * then update the buffer heads with the block allocations.
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003310 *
Theodore Ts'occd25062009-02-26 01:04:07 -05003311 * For now, though, we'll cheat by calling filemap_flush(),
3312 * which will map the blocks, and start the I/O, but not
3313 * actually wait for the I/O to complete.
3314 */
3315 return filemap_flush(inode->i_mapping);
3316}
Alex Tomas64769242008-07-11 19:27:31 -04003317
3318/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003319 * bmap() is special. It gets used by applications such as lilo and by
3320 * the swapper to find the on-disk block of a specific piece of data.
3321 *
3322 * Naturally, this is dangerous if the block concerned is still in the
Mingming Cao617ba132006-10-11 01:20:53 -07003323 * journal. If somebody makes a swapfile on an ext4 data-journaling
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003324 * filesystem and enables swap, then they may get a nasty shock when the
3325 * data getting swapped to that swapfile suddenly gets overwritten by
3326 * the original zero's written out previously to the journal and
3327 * awaiting writeback in the kernel's buffer cache.
3328 *
3329 * So, if we see any bmap calls here on a modified, data-journaled file,
3330 * take extra steps to flush any blocks which might be in the cache.
3331 */
Mingming Cao617ba132006-10-11 01:20:53 -07003332static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003333{
3334 struct inode *inode = mapping->host;
3335 journal_t *journal;
3336 int err;
3337
Alex Tomas64769242008-07-11 19:27:31 -04003338 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3339 test_opt(inode->i_sb, DELALLOC)) {
3340 /*
3341 * With delalloc we want to sync the file
3342 * so that we can make sure we allocate
3343 * blocks for file
3344 */
3345 filemap_write_and_wait(mapping);
3346 }
3347
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05003348 if (EXT4_JOURNAL(inode) &&
3349 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003350 /*
3351 * This is a REALLY heavyweight approach, but the use of
3352 * bmap on dirty files is expected to be extremely rare:
3353 * only if we run lilo or swapon on a freshly made file
3354 * do we expect this to happen.
3355 *
3356 * (bmap requires CAP_SYS_RAWIO so this does not
3357 * represent an unprivileged user DOS attack --- we'd be
3358 * in trouble if mortal users could trigger this path at
3359 * will.)
3360 *
Mingming Cao617ba132006-10-11 01:20:53 -07003361 * NB. EXT4_STATE_JDATA is not set on files other than
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003362 * regular files. If somebody wants to bmap a directory
3363 * or symlink and gets confused because the buffer
3364 * hasn't yet been flushed to disk, they deserve
3365 * everything they get.
3366 */
3367
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05003368 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
Mingming Cao617ba132006-10-11 01:20:53 -07003369 journal = EXT4_JOURNAL(inode);
Mingming Caodab291a2006-10-11 01:21:01 -07003370 jbd2_journal_lock_updates(journal);
3371 err = jbd2_journal_flush(journal);
3372 jbd2_journal_unlock_updates(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003373
3374 if (err)
3375 return 0;
3376 }
3377
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003378 return generic_block_bmap(mapping, block, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003379}
3380
Mingming Cao617ba132006-10-11 01:20:53 -07003381static int ext4_readpage(struct file *file, struct page *page)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003382{
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04003383 trace_ext4_readpage(page);
Mingming Cao617ba132006-10-11 01:20:53 -07003384 return mpage_readpage(page, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003385}
3386
3387static int
Mingming Cao617ba132006-10-11 01:20:53 -07003388ext4_readpages(struct file *file, struct address_space *mapping,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003389 struct list_head *pages, unsigned nr_pages)
3390{
Mingming Cao617ba132006-10-11 01:20:53 -07003391 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003392}
3393
Jiaying Zhang744692d2010-03-04 16:14:02 -05003394static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset)
3395{
3396 struct buffer_head *head, *bh;
3397 unsigned int curr_off = 0;
3398
3399 if (!page_has_buffers(page))
3400 return;
3401 head = bh = page_buffers(page);
3402 do {
3403 if (offset <= curr_off && test_clear_buffer_uninit(bh)
3404 && bh->b_private) {
3405 ext4_free_io_end(bh->b_private);
3406 bh->b_private = NULL;
3407 bh->b_end_io = NULL;
3408 }
3409 curr_off = curr_off + bh->b_size;
3410 bh = bh->b_this_page;
3411 } while (bh != head);
3412}
3413
Mingming Cao617ba132006-10-11 01:20:53 -07003414static void ext4_invalidatepage(struct page *page, unsigned long offset)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003415{
Mingming Cao617ba132006-10-11 01:20:53 -07003416 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003417
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04003418 trace_ext4_invalidatepage(page, offset);
3419
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003420 /*
Jiaying Zhang744692d2010-03-04 16:14:02 -05003421 * free any io_end structure allocated for buffers to be discarded
3422 */
3423 if (ext4_should_dioread_nolock(page->mapping->host))
3424 ext4_invalidatepage_free_endio(page, offset);
3425 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003426 * If it's a full truncate we just forget about the pending dirtying
3427 */
3428 if (offset == 0)
3429 ClearPageChecked(page);
3430
Frank Mayhar03901312009-01-07 00:06:22 -05003431 if (journal)
3432 jbd2_journal_invalidatepage(journal, page, offset);
3433 else
3434 block_invalidatepage(page, offset);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003435}
3436
Mingming Cao617ba132006-10-11 01:20:53 -07003437static int ext4_releasepage(struct page *page, gfp_t wait)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003438{
Mingming Cao617ba132006-10-11 01:20:53 -07003439 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003440
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04003441 trace_ext4_releasepage(page);
3442
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003443 WARN_ON(PageChecked(page));
3444 if (!page_has_buffers(page))
3445 return 0;
Frank Mayhar03901312009-01-07 00:06:22 -05003446 if (journal)
3447 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3448 else
3449 return try_to_free_buffers(page);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003450}
3451
3452/*
Mingming Cao4c0425f2009-09-28 15:48:41 -04003453 * O_DIRECT for ext3 (or indirect map) based files
3454 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003455 * If the O_DIRECT write will extend the file then add this inode to the
3456 * orphan list. So recovery will truncate it back to the original size
3457 * if the machine crashes during the write.
3458 *
3459 * If the O_DIRECT write is intantiating holes inside i_size and the machine
Jan Kara7fb54092008-02-10 01:08:38 -05003460 * crashes then stale disk data _may_ be exposed inside the file. But current
3461 * VFS code falls back into buffered path in that case so we are safe.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003462 */
Mingming Cao4c0425f2009-09-28 15:48:41 -04003463static ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003464 const struct iovec *iov, loff_t offset,
3465 unsigned long nr_segs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003466{
3467 struct file *file = iocb->ki_filp;
3468 struct inode *inode = file->f_mapping->host;
Mingming Cao617ba132006-10-11 01:20:53 -07003469 struct ext4_inode_info *ei = EXT4_I(inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003470 handle_t *handle;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003471 ssize_t ret;
3472 int orphan = 0;
3473 size_t count = iov_length(iov, nr_segs);
Eric Sandeenfbbf6942009-10-02 21:20:55 -04003474 int retries = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003475
3476 if (rw == WRITE) {
3477 loff_t final_size = offset + count;
3478
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003479 if (final_size > inode->i_size) {
Jan Kara7fb54092008-02-10 01:08:38 -05003480 /* Credits for sb + inode write */
3481 handle = ext4_journal_start(inode, 2);
3482 if (IS_ERR(handle)) {
3483 ret = PTR_ERR(handle);
3484 goto out;
3485 }
Mingming Cao617ba132006-10-11 01:20:53 -07003486 ret = ext4_orphan_add(handle, inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003487 if (ret) {
3488 ext4_journal_stop(handle);
3489 goto out;
3490 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003491 orphan = 1;
3492 ei->i_disksize = inode->i_size;
Jan Kara7fb54092008-02-10 01:08:38 -05003493 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003494 }
3495 }
3496
Eric Sandeenfbbf6942009-10-02 21:20:55 -04003497retry:
Jiaying Zhangb7adc1f2010-03-02 13:26:36 -05003498 if (rw == READ && ext4_should_dioread_nolock(inode))
Christoph Hellwigeafdc7d2010-06-04 11:29:53 +02003499 ret = __blockdev_direct_IO(rw, iocb, inode,
Jiaying Zhangb7adc1f2010-03-02 13:26:36 -05003500 inode->i_sb->s_bdev, iov,
3501 offset, nr_segs,
Christoph Hellwigeafdc7d2010-06-04 11:29:53 +02003502 ext4_get_block, NULL, NULL, 0);
3503 else {
Jiaying Zhangb7adc1f2010-03-02 13:26:36 -05003504 ret = blockdev_direct_IO(rw, iocb, inode,
3505 inode->i_sb->s_bdev, iov,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003506 offset, nr_segs,
Mingming Cao617ba132006-10-11 01:20:53 -07003507 ext4_get_block, NULL);
Christoph Hellwigeafdc7d2010-06-04 11:29:53 +02003508
3509 if (unlikely((rw & WRITE) && ret < 0)) {
3510 loff_t isize = i_size_read(inode);
3511 loff_t end = offset + iov_length(iov, nr_segs);
3512
3513 if (end > isize)
Jan Karaae24f282011-05-25 17:39:48 -04003514 ext4_truncate_failed_write(inode);
Christoph Hellwigeafdc7d2010-06-04 11:29:53 +02003515 }
3516 }
Eric Sandeenfbbf6942009-10-02 21:20:55 -04003517 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
3518 goto retry;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003519
Jan Kara7fb54092008-02-10 01:08:38 -05003520 if (orphan) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003521 int err;
3522
Jan Kara7fb54092008-02-10 01:08:38 -05003523 /* Credits for sb + inode write */
3524 handle = ext4_journal_start(inode, 2);
3525 if (IS_ERR(handle)) {
3526 /* This is really bad luck. We've written the data
3527 * but cannot extend i_size. Bail out and pretend
3528 * the write failed... */
3529 ret = PTR_ERR(handle);
Dmitry Monakhovda1dafc2010-03-01 23:15:02 -05003530 if (inode->i_nlink)
3531 ext4_orphan_del(NULL, inode);
3532
Jan Kara7fb54092008-02-10 01:08:38 -05003533 goto out;
3534 }
3535 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07003536 ext4_orphan_del(handle, inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003537 if (ret > 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003538 loff_t end = offset + ret;
3539 if (end > inode->i_size) {
3540 ei->i_disksize = end;
3541 i_size_write(inode, end);
3542 /*
3543 * We're going to return a positive `ret'
3544 * here due to non-zero-length I/O, so there's
3545 * no way of reporting error returns from
Mingming Cao617ba132006-10-11 01:20:53 -07003546 * ext4_mark_inode_dirty() to userspace. So
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003547 * ignore it.
3548 */
Mingming Cao617ba132006-10-11 01:20:53 -07003549 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003550 }
3551 }
Mingming Cao617ba132006-10-11 01:20:53 -07003552 err = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003553 if (ret == 0)
3554 ret = err;
3555 }
3556out:
3557 return ret;
3558}
3559
Theodore Ts'o2ed88682010-05-16 20:00:00 -04003560/*
3561 * ext4_get_block used when preparing for a DIO write or buffer write.
3562 * We allocate an uinitialized extent if blocks haven't been allocated.
3563 * The extent will be converted to initialized after the IO is complete.
3564 */
Jiaying Zhangc7064ef2010-03-02 13:28:44 -05003565static int ext4_get_block_write(struct inode *inode, sector_t iblock,
Mingming Cao4c0425f2009-09-28 15:48:41 -04003566 struct buffer_head *bh_result, int create)
3567{
Jiaying Zhangc7064ef2010-03-02 13:28:44 -05003568 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003569 inode->i_ino, create);
Theodore Ts'o2ed88682010-05-16 20:00:00 -04003570 return _ext4_get_block(inode, iblock, bh_result,
3571 EXT4_GET_BLOCKS_IO_CREATE_EXT);
Mingming Cao4c0425f2009-09-28 15:48:41 -04003572}
3573
Mingming Cao4c0425f2009-09-28 15:48:41 -04003574static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
Christoph Hellwig552ef8022010-07-27 11:56:06 -04003575 ssize_t size, void *private, int ret,
3576 bool is_async)
Mingming Cao4c0425f2009-09-28 15:48:41 -04003577{
3578 ext4_io_end_t *io_end = iocb->private;
3579 struct workqueue_struct *wq;
Jiaying Zhang744692d2010-03-04 16:14:02 -05003580 unsigned long flags;
3581 struct ext4_inode_info *ei;
Mingming Cao4c0425f2009-09-28 15:48:41 -04003582
Mingming4b70df12009-11-03 14:44:54 -05003583 /* if not async direct IO or dio with 0 bytes write, just return */
3584 if (!io_end || !size)
Christoph Hellwig552ef8022010-07-27 11:56:06 -04003585 goto out;
Mingming4b70df12009-11-03 14:44:54 -05003586
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003587 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3588 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3589 iocb->private, io_end->inode->i_ino, iocb, offset,
3590 size);
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003591
3592 /* if not aio dio with unwritten extents, just free io and return */
Theodore Ts'obd2d0212010-10-27 21:30:10 -04003593 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003594 ext4_free_io_end(io_end);
3595 iocb->private = NULL;
jiayingz@google.com (Jiaying Zhang)5b3ff232010-07-27 11:56:06 -04003596out:
3597 if (is_async)
3598 aio_complete(iocb, ret, 0);
3599 return;
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003600 }
3601
Mingming Cao4c0425f2009-09-28 15:48:41 -04003602 io_end->offset = offset;
3603 io_end->size = size;
jiayingz@google.com (Jiaying Zhang)5b3ff232010-07-27 11:56:06 -04003604 if (is_async) {
3605 io_end->iocb = iocb;
3606 io_end->result = ret;
3607 }
Mingming Cao4c0425f2009-09-28 15:48:41 -04003608 wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
3609
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003610 /* Add the io_end to per-inode completed aio dio list*/
Jiaying Zhang744692d2010-03-04 16:14:02 -05003611 ei = EXT4_I(io_end->inode);
3612 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
3613 list_add_tail(&io_end->list, &ei->i_completed_io_list);
3614 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
Eric Sandeenc999af22010-10-27 21:30:07 -04003615
3616 /* queue the work to convert unwritten extents to written */
3617 queue_work(wq, &io_end->work);
Mingming Cao4c0425f2009-09-28 15:48:41 -04003618 iocb->private = NULL;
3619}
Jiaying Zhangc7064ef2010-03-02 13:28:44 -05003620
Jiaying Zhang744692d2010-03-04 16:14:02 -05003621static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
3622{
3623 ext4_io_end_t *io_end = bh->b_private;
3624 struct workqueue_struct *wq;
3625 struct inode *inode;
3626 unsigned long flags;
3627
3628 if (!test_clear_buffer_uninit(bh) || !io_end)
3629 goto out;
3630
3631 if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
3632 printk("sb umounted, discard end_io request for inode %lu\n",
3633 io_end->inode->i_ino);
3634 ext4_free_io_end(io_end);
3635 goto out;
3636 }
3637
Theodore Ts'obd2d0212010-10-27 21:30:10 -04003638 io_end->flag = EXT4_IO_END_UNWRITTEN;
Jiaying Zhang744692d2010-03-04 16:14:02 -05003639 inode = io_end->inode;
3640
3641 /* Add the io_end to per-inode completed io list*/
3642 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
3643 list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
3644 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
3645
3646 wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
3647 /* queue the work to convert unwritten extents to written */
3648 queue_work(wq, &io_end->work);
3649out:
3650 bh->b_private = NULL;
3651 bh->b_end_io = NULL;
3652 clear_buffer_uninit(bh);
3653 end_buffer_async_write(bh, uptodate);
3654}
3655
3656static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
3657{
3658 ext4_io_end_t *io_end;
3659 struct page *page = bh->b_page;
3660 loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
3661 size_t size = bh->b_size;
3662
3663retry:
3664 io_end = ext4_init_io_end(inode, GFP_ATOMIC);
3665 if (!io_end) {
Andrew Morton6db26ff2011-01-12 16:59:13 -08003666 pr_warn_ratelimited("%s: allocation fail\n", __func__);
Jiaying Zhang744692d2010-03-04 16:14:02 -05003667 schedule();
3668 goto retry;
3669 }
3670 io_end->offset = offset;
3671 io_end->size = size;
3672 /*
3673 * We need to hold a reference to the page to make sure it
3674 * doesn't get evicted before ext4_end_io_work() has a chance
3675 * to convert the extent from written to unwritten.
3676 */
3677 io_end->page = page;
3678 get_page(io_end->page);
3679
3680 bh->b_private = io_end;
3681 bh->b_end_io = ext4_end_io_buffer_write;
3682 return 0;
3683}
3684
Mingming Cao4c0425f2009-09-28 15:48:41 -04003685/*
3686 * For ext4 extent files, ext4 will do direct-io write to holes,
3687 * preallocated extents, and those write extend the file, no need to
3688 * fall back to buffered IO.
3689 *
Uwe Kleine-Königb5950762010-11-01 15:38:34 -04003690 * For holes, we fallocate those blocks, mark them as uninitialized
Mingming Cao4c0425f2009-09-28 15:48:41 -04003691 * If those blocks were preallocated, we mark sure they are splited, but
Uwe Kleine-Königb5950762010-11-01 15:38:34 -04003692 * still keep the range to write as uninitialized.
Mingming Cao4c0425f2009-09-28 15:48:41 -04003693 *
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003694 * The unwrritten extents will be converted to written when DIO is completed.
3695 * For async direct IO, since the IO may still pending when return, we
Lucas De Marchi25985ed2011-03-30 22:57:33 -03003696 * set up an end_io call back function, which will do the conversion
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003697 * when async direct IO completed.
Mingming Cao4c0425f2009-09-28 15:48:41 -04003698 *
3699 * If the O_DIRECT write will extend the file then add this inode to the
3700 * orphan list. So recovery will truncate it back to the original size
3701 * if the machine crashes during the write.
3702 *
3703 */
3704static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
3705 const struct iovec *iov, loff_t offset,
3706 unsigned long nr_segs)
3707{
3708 struct file *file = iocb->ki_filp;
3709 struct inode *inode = file->f_mapping->host;
3710 ssize_t ret;
3711 size_t count = iov_length(iov, nr_segs);
3712
3713 loff_t final_size = offset + count;
3714 if (rw == WRITE && final_size <= inode->i_size) {
3715 /*
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003716 * We could direct write to holes and fallocate.
3717 *
3718 * Allocated blocks to fill the hole are marked as uninitialized
Lucas De Marchi25985ed2011-03-30 22:57:33 -03003719 * to prevent parallel buffered read to expose the stale data
Mingming Cao4c0425f2009-09-28 15:48:41 -04003720 * before DIO complete the data IO.
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003721 *
3722 * As to previously fallocated extents, ext4 get_block
Mingming Cao4c0425f2009-09-28 15:48:41 -04003723 * will just simply mark the buffer mapped but still
3724 * keep the extents uninitialized.
3725 *
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003726 * for non AIO case, we will convert those unwritten extents
3727 * to written after return back from blockdev_direct_IO.
3728 *
3729 * for async DIO, the conversion needs to be defered when
3730 * the IO is completed. The ext4 end_io callback function
3731 * will be called to take care of the conversion work.
3732 * Here for async case, we allocate an io_end structure to
3733 * hook to the iocb.
Mingming Cao4c0425f2009-09-28 15:48:41 -04003734 */
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003735 iocb->private = NULL;
3736 EXT4_I(inode)->cur_aio_dio = NULL;
3737 if (!is_sync_kiocb(iocb)) {
Jiaying Zhang744692d2010-03-04 16:14:02 -05003738 iocb->private = ext4_init_io_end(inode, GFP_NOFS);
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003739 if (!iocb->private)
3740 return -ENOMEM;
3741 /*
3742 * we save the io structure for current async
Eric Sandeen79e83032010-07-27 11:56:07 -04003743 * direct IO, so that later ext4_map_blocks()
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003744 * could flag the io structure whether there
3745 * is a unwritten extents needs to be converted
3746 * when IO is completed.
3747 */
3748 EXT4_I(inode)->cur_aio_dio = iocb->private;
3749 }
3750
Mingming Cao4c0425f2009-09-28 15:48:41 -04003751 ret = blockdev_direct_IO(rw, iocb, inode,
3752 inode->i_sb->s_bdev, iov,
3753 offset, nr_segs,
Jiaying Zhangc7064ef2010-03-02 13:28:44 -05003754 ext4_get_block_write,
Mingming Cao4c0425f2009-09-28 15:48:41 -04003755 ext4_end_io_dio);
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003756 if (iocb->private)
3757 EXT4_I(inode)->cur_aio_dio = NULL;
3758 /*
3759 * The io_end structure takes a reference to the inode,
3760 * that structure needs to be destroyed and the
3761 * reference to the inode need to be dropped, when IO is
3762 * complete, even with 0 byte write, or failed.
3763 *
3764 * In the successful AIO DIO case, the io_end structure will be
3765 * desctroyed and the reference to the inode will be dropped
3766 * after the end_io call back function is called.
3767 *
3768 * In the case there is 0 byte write, or error case, since
3769 * VFS direct IO won't invoke the end_io call back function,
3770 * we need to free the end_io structure here.
3771 */
3772 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
3773 ext4_free_io_end(iocb->private);
3774 iocb->private = NULL;
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05003775 } else if (ret > 0 && ext4_test_inode_state(inode,
3776 EXT4_STATE_DIO_UNWRITTEN)) {
Mingming109f5562009-11-10 10:48:08 -05003777 int err;
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003778 /*
3779 * for non AIO case, since the IO is already
Lucas De Marchi25985ed2011-03-30 22:57:33 -03003780 * completed, we could do the conversion right here
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003781 */
Mingming109f5562009-11-10 10:48:08 -05003782 err = ext4_convert_unwritten_extents(inode,
3783 offset, ret);
3784 if (err < 0)
3785 ret = err;
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05003786 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
Mingming109f5562009-11-10 10:48:08 -05003787 }
Mingming Cao4c0425f2009-09-28 15:48:41 -04003788 return ret;
3789 }
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003790
3791 /* for write the the end of file case, we fall back to old way */
Mingming Cao4c0425f2009-09-28 15:48:41 -04003792 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3793}
3794
3795static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3796 const struct iovec *iov, loff_t offset,
3797 unsigned long nr_segs)
3798{
3799 struct file *file = iocb->ki_filp;
3800 struct inode *inode = file->f_mapping->host;
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04003801 ssize_t ret;
Mingming Cao4c0425f2009-09-28 15:48:41 -04003802
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04003803 trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04003804 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04003805 ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3806 else
3807 ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3808 trace_ext4_direct_IO_exit(inode, offset,
3809 iov_length(iov, nr_segs), rw, ret);
3810 return ret;
Mingming Cao4c0425f2009-09-28 15:48:41 -04003811}
3812
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003813/*
Mingming Cao617ba132006-10-11 01:20:53 -07003814 * Pages can be marked dirty completely asynchronously from ext4's journalling
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003815 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3816 * much here because ->set_page_dirty is called under VFS locks. The page is
3817 * not necessarily locked.
3818 *
3819 * We cannot just dirty the page and leave attached buffers clean, because the
3820 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3821 * or jbddirty because all the journalling code will explode.
3822 *
3823 * So what we do is to mark the page "pending dirty" and next time writepage
3824 * is called, propagate that into the buffers appropriately.
3825 */
Mingming Cao617ba132006-10-11 01:20:53 -07003826static int ext4_journalled_set_page_dirty(struct page *page)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003827{
3828 SetPageChecked(page);
3829 return __set_page_dirty_nobuffers(page);
3830}
3831
Mingming Cao617ba132006-10-11 01:20:53 -07003832static const struct address_space_operations ext4_ordered_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003833 .readpage = ext4_readpage,
3834 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003835 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003836 .write_begin = ext4_write_begin,
3837 .write_end = ext4_ordered_write_end,
3838 .bmap = ext4_bmap,
3839 .invalidatepage = ext4_invalidatepage,
3840 .releasepage = ext4_releasepage,
3841 .direct_IO = ext4_direct_IO,
3842 .migratepage = buffer_migrate_page,
3843 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02003844 .error_remove_page = generic_error_remove_page,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003845};
3846
Mingming Cao617ba132006-10-11 01:20:53 -07003847static const struct address_space_operations ext4_writeback_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003848 .readpage = ext4_readpage,
3849 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003850 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003851 .write_begin = ext4_write_begin,
3852 .write_end = ext4_writeback_write_end,
3853 .bmap = ext4_bmap,
3854 .invalidatepage = ext4_invalidatepage,
3855 .releasepage = ext4_releasepage,
3856 .direct_IO = ext4_direct_IO,
3857 .migratepage = buffer_migrate_page,
3858 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02003859 .error_remove_page = generic_error_remove_page,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003860};
3861
Mingming Cao617ba132006-10-11 01:20:53 -07003862static const struct address_space_operations ext4_journalled_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003863 .readpage = ext4_readpage,
3864 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003865 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003866 .write_begin = ext4_write_begin,
3867 .write_end = ext4_journalled_write_end,
3868 .set_page_dirty = ext4_journalled_set_page_dirty,
3869 .bmap = ext4_bmap,
3870 .invalidatepage = ext4_invalidatepage,
3871 .releasepage = ext4_releasepage,
3872 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02003873 .error_remove_page = generic_error_remove_page,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003874};
3875
Alex Tomas64769242008-07-11 19:27:31 -04003876static const struct address_space_operations ext4_da_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003877 .readpage = ext4_readpage,
3878 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003879 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003880 .writepages = ext4_da_writepages,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003881 .write_begin = ext4_da_write_begin,
3882 .write_end = ext4_da_write_end,
3883 .bmap = ext4_bmap,
3884 .invalidatepage = ext4_da_invalidatepage,
3885 .releasepage = ext4_releasepage,
3886 .direct_IO = ext4_direct_IO,
3887 .migratepage = buffer_migrate_page,
3888 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02003889 .error_remove_page = generic_error_remove_page,
Alex Tomas64769242008-07-11 19:27:31 -04003890};
3891
Mingming Cao617ba132006-10-11 01:20:53 -07003892void ext4_set_aops(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003893{
Aneesh Kumar K.Vcd1aac32008-07-11 19:27:31 -04003894 if (ext4_should_order_data(inode) &&
3895 test_opt(inode->i_sb, DELALLOC))
3896 inode->i_mapping->a_ops = &ext4_da_aops;
3897 else if (ext4_should_order_data(inode))
Mingming Cao617ba132006-10-11 01:20:53 -07003898 inode->i_mapping->a_ops = &ext4_ordered_aops;
Alex Tomas64769242008-07-11 19:27:31 -04003899 else if (ext4_should_writeback_data(inode) &&
3900 test_opt(inode->i_sb, DELALLOC))
3901 inode->i_mapping->a_ops = &ext4_da_aops;
Mingming Cao617ba132006-10-11 01:20:53 -07003902 else if (ext4_should_writeback_data(inode))
3903 inode->i_mapping->a_ops = &ext4_writeback_aops;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003904 else
Mingming Cao617ba132006-10-11 01:20:53 -07003905 inode->i_mapping->a_ops = &ext4_journalled_aops;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003906}
3907
3908/*
Mingming Cao617ba132006-10-11 01:20:53 -07003909 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003910 * up to the end of the block which corresponds to `from'.
3911 * This required during truncate. We need to physically zero the tail end
3912 * of that block so it doesn't yield old data if the file is later grown.
3913 */
Jan Karacf108bc2008-07-11 19:27:31 -04003914int ext4_block_truncate_page(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003915 struct address_space *mapping, loff_t from)
3916{
Allison Henderson30848852011-05-25 07:41:32 -04003917 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3918 unsigned length;
3919 unsigned blocksize;
3920 struct inode *inode = mapping->host;
3921
3922 blocksize = inode->i_sb->s_blocksize;
3923 length = blocksize - (offset & (blocksize - 1));
3924
3925 return ext4_block_zero_page_range(handle, mapping, from, length);
3926}
3927
3928/*
3929 * ext4_block_zero_page_range() zeros out a mapping of length 'length'
3930 * starting from file offset 'from'. The range to be zero'd must
3931 * be contained with in one block. If the specified range exceeds
3932 * the end of the block it will be shortened to end of the block
3933 * that cooresponds to 'from'
3934 */
3935int ext4_block_zero_page_range(handle_t *handle,
3936 struct address_space *mapping, loff_t from, loff_t length)
3937{
Mingming Cao617ba132006-10-11 01:20:53 -07003938 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003939 unsigned offset = from & (PAGE_CACHE_SIZE-1);
Allison Henderson30848852011-05-25 07:41:32 -04003940 unsigned blocksize, max, pos;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003941 ext4_lblk_t iblock;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003942 struct inode *inode = mapping->host;
3943 struct buffer_head *bh;
Jan Karacf108bc2008-07-11 19:27:31 -04003944 struct page *page;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003945 int err = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003946
Theodore Ts'of4a01012009-07-05 22:08:16 -04003947 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3948 mapping_gfp_mask(mapping) & ~__GFP_FS);
Jan Karacf108bc2008-07-11 19:27:31 -04003949 if (!page)
3950 return -EINVAL;
3951
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003952 blocksize = inode->i_sb->s_blocksize;
Allison Henderson30848852011-05-25 07:41:32 -04003953 max = blocksize - (offset & (blocksize - 1));
3954
3955 /*
3956 * correct length if it does not fall between
3957 * 'from' and the end of the block
3958 */
3959 if (length > max || length < 0)
3960 length = max;
3961
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003962 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3963
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003964 if (!page_has_buffers(page))
3965 create_empty_buffers(page, blocksize, 0);
3966
3967 /* Find the buffer that contains "offset" */
3968 bh = page_buffers(page);
3969 pos = blocksize;
3970 while (offset >= pos) {
3971 bh = bh->b_this_page;
3972 iblock++;
3973 pos += blocksize;
3974 }
3975
3976 err = 0;
3977 if (buffer_freed(bh)) {
3978 BUFFER_TRACE(bh, "freed: skip");
3979 goto unlock;
3980 }
3981
3982 if (!buffer_mapped(bh)) {
3983 BUFFER_TRACE(bh, "unmapped");
Mingming Cao617ba132006-10-11 01:20:53 -07003984 ext4_get_block(inode, iblock, bh, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003985 /* unmapped? It's a hole - nothing to do */
3986 if (!buffer_mapped(bh)) {
3987 BUFFER_TRACE(bh, "still unmapped");
3988 goto unlock;
3989 }
3990 }
3991
3992 /* Ok, it's mapped. Make sure it's up-to-date */
3993 if (PageUptodate(page))
3994 set_buffer_uptodate(bh);
3995
3996 if (!buffer_uptodate(bh)) {
3997 err = -EIO;
3998 ll_rw_block(READ, 1, &bh);
3999 wait_on_buffer(bh);
4000 /* Uhhuh. Read error. Complain and punt. */
4001 if (!buffer_uptodate(bh))
4002 goto unlock;
4003 }
4004
Mingming Cao617ba132006-10-11 01:20:53 -07004005 if (ext4_should_journal_data(inode)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004006 BUFFER_TRACE(bh, "get write access");
Mingming Cao617ba132006-10-11 01:20:53 -07004007 err = ext4_journal_get_write_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004008 if (err)
4009 goto unlock;
4010 }
4011
Christoph Lametereebd2aa2008-02-04 22:28:29 -08004012 zero_user(page, offset, length);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004013
4014 BUFFER_TRACE(bh, "zeroed end of block");
4015
4016 err = 0;
Mingming Cao617ba132006-10-11 01:20:53 -07004017 if (ext4_should_journal_data(inode)) {
Frank Mayhar03901312009-01-07 00:06:22 -05004018 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004019 } else {
Theodore Ts'o8aefcd52011-01-10 12:29:43 -05004020 if (ext4_should_order_data(inode) && EXT4_I(inode)->jinode)
Jan Kara678aaf42008-07-11 19:27:31 -04004021 err = ext4_jbd2_file_inode(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004022 mark_buffer_dirty(bh);
4023 }
4024
4025unlock:
4026 unlock_page(page);
4027 page_cache_release(page);
4028 return err;
4029}
4030
4031/*
4032 * Probably it should be a library function... search for first non-zero word
4033 * or memcmp with zero_page, whatever is better for particular architecture.
4034 * Linus?
4035 */
4036static inline int all_zeroes(__le32 *p, __le32 *q)
4037{
4038 while (p < q)
4039 if (*p++)
4040 return 0;
4041 return 1;
4042}
4043
4044/**
Mingming Cao617ba132006-10-11 01:20:53 -07004045 * ext4_find_shared - find the indirect blocks for partial truncation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004046 * @inode: inode in question
4047 * @depth: depth of the affected branch
Mingming Cao617ba132006-10-11 01:20:53 -07004048 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004049 * @chain: place to store the pointers to partial indirect blocks
4050 * @top: place to the (detached) top of branch
4051 *
Mingming Cao617ba132006-10-11 01:20:53 -07004052 * This is a helper function used by ext4_truncate().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004053 *
4054 * When we do truncate() we may have to clean the ends of several
4055 * indirect blocks but leave the blocks themselves alive. Block is
Lucas De Marchi25985ed2011-03-30 22:57:33 -03004056 * partially truncated if some data below the new i_size is referred
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004057 * from it (and it is on the path to the first completely truncated
4058 * data block, indeed). We have to free the top of that path along
4059 * with everything to the right of the path. Since no allocation
Mingming Cao617ba132006-10-11 01:20:53 -07004060 * past the truncation point is possible until ext4_truncate()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004061 * finishes, we may safely do the latter, but top of branch may
4062 * require special attention - pageout below the truncation point
4063 * might try to populate it.
4064 *
4065 * We atomically detach the top of branch from the tree, store the
4066 * block number of its root in *@top, pointers to buffer_heads of
4067 * partially truncated blocks - in @chain[].bh and pointers to
4068 * their last elements that should not be removed - in
4069 * @chain[].p. Return value is the pointer to last filled element
4070 * of @chain.
4071 *
4072 * The work left to caller to do the actual freeing of subtrees:
4073 * a) free the subtree starting from *@top
4074 * b) free the subtrees whose roots are stored in
4075 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4076 * c) free the subtrees growing from the inode past the @chain[0].
4077 * (no partially truncated stuff there). */
4078
Mingming Cao617ba132006-10-11 01:20:53 -07004079static Indirect *ext4_find_shared(struct inode *inode, int depth,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004080 ext4_lblk_t offsets[4], Indirect chain[4],
4081 __le32 *top)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004082{
4083 Indirect *partial, *p;
4084 int k, err;
4085
4086 *top = 0;
Uwe Kleine-Königbf48aab2009-10-28 20:11:03 +01004087 /* Make k index the deepest non-null offset + 1 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004088 for (k = depth; k > 1 && !offsets[k-1]; k--)
4089 ;
Mingming Cao617ba132006-10-11 01:20:53 -07004090 partial = ext4_get_branch(inode, k, offsets, chain, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004091 /* Writer: pointers */
4092 if (!partial)
4093 partial = chain + k-1;
4094 /*
4095 * If the branch acquired continuation since we've looked at it -
4096 * fine, it should all survive and (new) top doesn't belong to us.
4097 */
4098 if (!partial->key && *partial->p)
4099 /* Writer: end */
4100 goto no_top;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004101 for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004102 ;
4103 /*
4104 * OK, we've found the last block that must survive. The rest of our
4105 * branch should be detached before unlocking. However, if that rest
4106 * of branch is all ours and does not grow immediately from the inode
4107 * it's easier to cheat and just decrement partial->p.
4108 */
4109 if (p == chain + k - 1 && p > chain) {
4110 p->p--;
4111 } else {
4112 *top = *p->p;
Mingming Cao617ba132006-10-11 01:20:53 -07004113 /* Nope, don't do this in ext4. Must leave the tree intact */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004114#if 0
4115 *p->p = 0;
4116#endif
4117 }
4118 /* Writer: end */
4119
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004120 while (partial > p) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004121 brelse(partial->bh);
4122 partial--;
4123 }
4124no_top:
4125 return partial;
4126}
4127
4128/*
4129 * Zero a number of block pointers in either an inode or an indirect block.
4130 * If we restart the transaction we must again get write access to the
4131 * indirect block for further modification.
4132 *
4133 * We release `count' blocks on disk, but (last - first) may be greater
4134 * than `count' because there can be holes in there.
Amir Goldsteind67d1212011-03-20 22:59:02 -04004135 *
4136 * Return 0 on success, 1 on invalid block range
4137 * and < 0 on fatal error.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004138 */
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004139static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
4140 struct buffer_head *bh,
4141 ext4_fsblk_t block_to_free,
4142 unsigned long count, __le32 *first,
4143 __le32 *last)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004144{
4145 __le32 *p;
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004146 int flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED;
Theodore Ts'ob4097142011-01-10 12:46:59 -05004147 int err;
Theodore Ts'oe6362602009-11-23 07:17:05 -05004148
4149 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
4150 flags |= EXT4_FREE_BLOCKS_METADATA;
Theodore Ts'o50689692009-11-23 07:17:34 -05004151
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004152 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free,
4153 count)) {
Theodore Ts'o24676da2010-05-16 21:00:00 -04004154 EXT4_ERROR_INODE(inode, "attempt to clear invalid "
4155 "blocks %llu len %lu",
4156 (unsigned long long) block_to_free, count);
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004157 return 1;
4158 }
4159
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004160 if (try_to_extend_transaction(handle, inode)) {
4161 if (bh) {
Frank Mayhar03901312009-01-07 00:06:22 -05004162 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
Theodore Ts'ob4097142011-01-10 12:46:59 -05004163 err = ext4_handle_dirty_metadata(handle, inode, bh);
Amir Goldsteind67d1212011-03-20 22:59:02 -04004164 if (unlikely(err))
4165 goto out_err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004166 }
Theodore Ts'ob4097142011-01-10 12:46:59 -05004167 err = ext4_mark_inode_dirty(handle, inode);
Amir Goldsteind67d1212011-03-20 22:59:02 -04004168 if (unlikely(err))
4169 goto out_err;
Theodore Ts'ob4097142011-01-10 12:46:59 -05004170 err = ext4_truncate_restart_trans(handle, inode,
4171 blocks_for_truncate(inode));
Amir Goldsteind67d1212011-03-20 22:59:02 -04004172 if (unlikely(err))
4173 goto out_err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004174 if (bh) {
4175 BUFFER_TRACE(bh, "retaking write access");
Amir Goldsteind67d1212011-03-20 22:59:02 -04004176 err = ext4_journal_get_write_access(handle, bh);
4177 if (unlikely(err))
4178 goto out_err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004179 }
4180 }
4181
Theodore Ts'oe6362602009-11-23 07:17:05 -05004182 for (p = first; p < last; p++)
4183 *p = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004184
Peter Huewe7dc57612011-02-21 21:01:42 -05004185 ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004186 return 0;
Amir Goldsteind67d1212011-03-20 22:59:02 -04004187out_err:
4188 ext4_std_error(inode->i_sb, err);
4189 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004190}
4191
4192/**
Mingming Cao617ba132006-10-11 01:20:53 -07004193 * ext4_free_data - free a list of data blocks
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004194 * @handle: handle for this transaction
4195 * @inode: inode we are dealing with
4196 * @this_bh: indirect buffer_head which contains *@first and *@last
4197 * @first: array of block numbers
4198 * @last: points immediately past the end of array
4199 *
Lucas De Marchi25985ed2011-03-30 22:57:33 -03004200 * We are freeing all blocks referred from that array (numbers are stored as
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004201 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4202 *
4203 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4204 * blocks are contiguous then releasing them at one time will only affect one
4205 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4206 * actually use a lot of journal space.
4207 *
4208 * @this_bh will be %NULL if @first and @last point into the inode's direct
4209 * block pointers.
4210 */
Mingming Cao617ba132006-10-11 01:20:53 -07004211static void ext4_free_data(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004212 struct buffer_head *this_bh,
4213 __le32 *first, __le32 *last)
4214{
Mingming Cao617ba132006-10-11 01:20:53 -07004215 ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004216 unsigned long count = 0; /* Number of blocks in the run */
4217 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
4218 corresponding to
4219 block_to_free */
Mingming Cao617ba132006-10-11 01:20:53 -07004220 ext4_fsblk_t nr; /* Current block # */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004221 __le32 *p; /* Pointer into inode/ind
4222 for current block */
Amir Goldsteind67d1212011-03-20 22:59:02 -04004223 int err = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004224
4225 if (this_bh) { /* For indirect block */
4226 BUFFER_TRACE(this_bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07004227 err = ext4_journal_get_write_access(handle, this_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004228 /* Important: if we can't update the indirect pointers
4229 * to the blocks, we can't free them. */
4230 if (err)
4231 return;
4232 }
4233
4234 for (p = first; p < last; p++) {
4235 nr = le32_to_cpu(*p);
4236 if (nr) {
4237 /* accumulate blocks to free if they're contiguous */
4238 if (count == 0) {
4239 block_to_free = nr;
4240 block_to_free_p = p;
4241 count = 1;
4242 } else if (nr == block_to_free + count) {
4243 count++;
4244 } else {
Amir Goldsteind67d1212011-03-20 22:59:02 -04004245 err = ext4_clear_blocks(handle, inode, this_bh,
4246 block_to_free, count,
4247 block_to_free_p, p);
4248 if (err)
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004249 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004250 block_to_free = nr;
4251 block_to_free_p = p;
4252 count = 1;
4253 }
4254 }
4255 }
4256
Amir Goldsteind67d1212011-03-20 22:59:02 -04004257 if (!err && count > 0)
4258 err = ext4_clear_blocks(handle, inode, this_bh, block_to_free,
4259 count, block_to_free_p, p);
4260 if (err < 0)
4261 /* fatal error */
4262 return;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004263
4264 if (this_bh) {
Frank Mayhar03901312009-01-07 00:06:22 -05004265 BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
Duane Griffin71dc8fb2008-07-11 19:27:31 -04004266
4267 /*
4268 * The buffer head should have an attached journal head at this
4269 * point. However, if the data is corrupted and an indirect
4270 * block pointed to itself, it would have been detached when
4271 * the block was cleared. Check for this instead of OOPSing.
4272 */
Theodore Ts'oe7f07962009-01-20 09:50:19 -05004273 if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
Frank Mayhar03901312009-01-07 00:06:22 -05004274 ext4_handle_dirty_metadata(handle, inode, this_bh);
Duane Griffin71dc8fb2008-07-11 19:27:31 -04004275 else
Theodore Ts'o24676da2010-05-16 21:00:00 -04004276 EXT4_ERROR_INODE(inode,
4277 "circular indirect block detected at "
4278 "block %llu",
4279 (unsigned long long) this_bh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004280 }
4281}
4282
4283/**
Mingming Cao617ba132006-10-11 01:20:53 -07004284 * ext4_free_branches - free an array of branches
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004285 * @handle: JBD handle for this transaction
4286 * @inode: inode we are dealing with
4287 * @parent_bh: the buffer_head which contains *@first and *@last
4288 * @first: array of block numbers
4289 * @last: pointer immediately past the end of array
4290 * @depth: depth of the branches to free
4291 *
Lucas De Marchi25985ed2011-03-30 22:57:33 -03004292 * We are freeing all blocks referred from these branches (numbers are
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004293 * stored as little-endian 32-bit) and updating @inode->i_blocks
4294 * appropriately.
4295 */
Mingming Cao617ba132006-10-11 01:20:53 -07004296static void ext4_free_branches(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004297 struct buffer_head *parent_bh,
4298 __le32 *first, __le32 *last, int depth)
4299{
Mingming Cao617ba132006-10-11 01:20:53 -07004300 ext4_fsblk_t nr;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004301 __le32 *p;
4302
Frank Mayhar03901312009-01-07 00:06:22 -05004303 if (ext4_handle_is_aborted(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004304 return;
4305
4306 if (depth--) {
4307 struct buffer_head *bh;
Mingming Cao617ba132006-10-11 01:20:53 -07004308 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004309 p = last;
4310 while (--p >= first) {
4311 nr = le32_to_cpu(*p);
4312 if (!nr)
4313 continue; /* A hole */
4314
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004315 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb),
4316 nr, 1)) {
Theodore Ts'o24676da2010-05-16 21:00:00 -04004317 EXT4_ERROR_INODE(inode,
4318 "invalid indirect mapped "
4319 "block %lu (level %d)",
4320 (unsigned long) nr, depth);
Theodore Ts'o1f2acb62010-01-22 17:40:42 -05004321 break;
4322 }
4323
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004324 /* Go read the buffer for the next level down */
4325 bh = sb_bread(inode->i_sb, nr);
4326
4327 /*
4328 * A read failure? Report error and clear slot
4329 * (should be rare).
4330 */
4331 if (!bh) {
Theodore Ts'oc398eda2010-07-27 11:56:40 -04004332 EXT4_ERROR_INODE_BLOCK(inode, nr,
4333 "Read failure");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004334 continue;
4335 }
4336
4337 /* This zaps the entire block. Bottom up. */
4338 BUFFER_TRACE(bh, "free child branches");
Mingming Cao617ba132006-10-11 01:20:53 -07004339 ext4_free_branches(handle, inode, bh,
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004340 (__le32 *) bh->b_data,
4341 (__le32 *) bh->b_data + addr_per_block,
4342 depth);
Theodore Ts'o1c5b9e92011-01-10 12:51:28 -05004343 brelse(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004344
4345 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004346 * Everything below this this pointer has been
4347 * released. Now let this top-of-subtree go.
4348 *
4349 * We want the freeing of this indirect block to be
4350 * atomic in the journal with the updating of the
4351 * bitmap block which owns it. So make some room in
4352 * the journal.
4353 *
4354 * We zero the parent pointer *after* freeing its
4355 * pointee in the bitmaps, so if extend_transaction()
4356 * for some reason fails to put the bitmap changes and
4357 * the release into the same transaction, recovery
4358 * will merely complain about releasing a free block,
4359 * rather than leaking blocks.
4360 */
Frank Mayhar03901312009-01-07 00:06:22 -05004361 if (ext4_handle_is_aborted(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004362 return;
4363 if (try_to_extend_transaction(handle, inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004364 ext4_mark_inode_dirty(handle, inode);
Jan Kara487caee2009-08-17 22:17:20 -04004365 ext4_truncate_restart_trans(handle, inode,
4366 blocks_for_truncate(inode));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004367 }
4368
Amir G40389682010-07-27 11:56:05 -04004369 /*
4370 * The forget flag here is critical because if
4371 * we are journaling (and not doing data
4372 * journaling), we have to make sure a revoke
4373 * record is written to prevent the journal
4374 * replay from overwriting the (former)
4375 * indirect block if it gets reallocated as a
4376 * data block. This must happen in the same
4377 * transaction where the data blocks are
4378 * actually freed.
4379 */
Peter Huewe7dc57612011-02-21 21:01:42 -05004380 ext4_free_blocks(handle, inode, NULL, nr, 1,
Amir G40389682010-07-27 11:56:05 -04004381 EXT4_FREE_BLOCKS_METADATA|
4382 EXT4_FREE_BLOCKS_FORGET);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004383
4384 if (parent_bh) {
4385 /*
4386 * The block which we have just freed is
4387 * pointed to by an indirect block: journal it
4388 */
4389 BUFFER_TRACE(parent_bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07004390 if (!ext4_journal_get_write_access(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004391 parent_bh)){
4392 *p = 0;
4393 BUFFER_TRACE(parent_bh,
Frank Mayhar03901312009-01-07 00:06:22 -05004394 "call ext4_handle_dirty_metadata");
4395 ext4_handle_dirty_metadata(handle,
4396 inode,
4397 parent_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004398 }
4399 }
4400 }
4401 } else {
4402 /* We have reached the bottom of the tree. */
4403 BUFFER_TRACE(parent_bh, "free data blocks");
Mingming Cao617ba132006-10-11 01:20:53 -07004404 ext4_free_data(handle, inode, parent_bh, first, last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004405 }
4406}
4407
Duane Griffin91ef4ca2008-07-11 19:27:31 -04004408int ext4_can_truncate(struct inode *inode)
4409{
Duane Griffin91ef4ca2008-07-11 19:27:31 -04004410 if (S_ISREG(inode->i_mode))
4411 return 1;
4412 if (S_ISDIR(inode->i_mode))
4413 return 1;
4414 if (S_ISLNK(inode->i_mode))
4415 return !ext4_inode_is_fast_symlink(inode);
4416 return 0;
4417}
4418
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004419/*
Allison Hendersona4bb6b62011-05-25 07:41:50 -04004420 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
4421 * associated with the given offset and length
4422 *
4423 * @inode: File inode
4424 * @offset: The offset where the hole will begin
4425 * @len: The length of the hole
4426 *
4427 * Returns: 0 on sucess or negative on failure
4428 */
4429
4430int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
4431{
4432 struct inode *inode = file->f_path.dentry->d_inode;
4433 if (!S_ISREG(inode->i_mode))
4434 return -ENOTSUPP;
4435
4436 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
4437 /* TODO: Add support for non extent hole punching */
4438 return -ENOTSUPP;
4439 }
4440
4441 return ext4_ext_punch_hole(file, offset, length);
4442}
4443
4444/*
Mingming Cao617ba132006-10-11 01:20:53 -07004445 * ext4_truncate()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004446 *
Mingming Cao617ba132006-10-11 01:20:53 -07004447 * We block out ext4_get_block() block instantiations across the entire
4448 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004449 * simultaneously on behalf of the same inode.
4450 *
4451 * As we work through the truncate and commmit bits of it to the journal there
4452 * is one core, guiding principle: the file's tree must always be consistent on
4453 * disk. We must be able to restart the truncate after a crash.
4454 *
4455 * The file's tree may be transiently inconsistent in memory (although it
4456 * probably isn't), but whenever we close off and commit a journal transaction,
4457 * the contents of (the filesystem + the journal) must be consistent and
4458 * restartable. It's pretty simple, really: bottom up, right to left (although
4459 * left-to-right works OK too).
4460 *
4461 * Note that at recovery time, journal replay occurs *before* the restart of
4462 * truncate against the orphan inode list.
4463 *
4464 * The committed inode has the new, desired i_size (which is the same as
Mingming Cao617ba132006-10-11 01:20:53 -07004465 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004466 * that this inode's truncate did not complete and it will again call
Mingming Cao617ba132006-10-11 01:20:53 -07004467 * ext4_truncate() to have another go. So there will be instantiated blocks
4468 * to the right of the truncation point in a crashed ext4 filesystem. But
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004469 * that's fine - as long as they are linked from the inode, the post-crash
Mingming Cao617ba132006-10-11 01:20:53 -07004470 * ext4_truncate() run will find them and release them.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004471 */
Mingming Cao617ba132006-10-11 01:20:53 -07004472void ext4_truncate(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004473{
4474 handle_t *handle;
Mingming Cao617ba132006-10-11 01:20:53 -07004475 struct ext4_inode_info *ei = EXT4_I(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004476 __le32 *i_data = ei->i_data;
Mingming Cao617ba132006-10-11 01:20:53 -07004477 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004478 struct address_space *mapping = inode->i_mapping;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05004479 ext4_lblk_t offsets[4];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004480 Indirect chain[4];
4481 Indirect *partial;
4482 __le32 nr = 0;
Kazuya Miof80da1e2011-04-10 22:06:36 -04004483 int n = 0;
4484 ext4_lblk_t last_block, max_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004485 unsigned blocksize = inode->i_sb->s_blocksize;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004486
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04004487 trace_ext4_truncate_enter(inode);
4488
Duane Griffin91ef4ca2008-07-11 19:27:31 -04004489 if (!ext4_can_truncate(inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004490 return;
4491
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04004492 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
Jiaying Zhangc8d46e42010-02-24 09:52:53 -05004493
Theodore Ts'o5534fb52009-09-17 09:34:16 -04004494 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05004495 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
Theodore Ts'o7d8f9f72009-02-24 08:21:14 -05004496
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04004497 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
Jan Karacf108bc2008-07-11 19:27:31 -04004498 ext4_ext_truncate(inode);
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04004499 trace_ext4_truncate_exit(inode);
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05004500 return;
4501 }
Alex Tomasa86c6182006-10-11 01:21:03 -07004502
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004503 handle = start_transaction(inode);
Jan Karacf108bc2008-07-11 19:27:31 -04004504 if (IS_ERR(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004505 return; /* AKPM: return what? */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004506
4507 last_block = (inode->i_size + blocksize-1)
Mingming Cao617ba132006-10-11 01:20:53 -07004508 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
Kazuya Miof80da1e2011-04-10 22:06:36 -04004509 max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
4510 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004511
Jan Karacf108bc2008-07-11 19:27:31 -04004512 if (inode->i_size & (blocksize - 1))
4513 if (ext4_block_truncate_page(handle, mapping, inode->i_size))
4514 goto out_stop;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004515
Kazuya Miof80da1e2011-04-10 22:06:36 -04004516 if (last_block != max_block) {
4517 n = ext4_block_to_path(inode, last_block, offsets, NULL);
4518 if (n == 0)
4519 goto out_stop; /* error */
4520 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004521
4522 /*
4523 * OK. This truncate is going to happen. We add the inode to the
4524 * orphan list, so that if this truncate spans multiple transactions,
4525 * and we crash, we will resume the truncate when the filesystem
4526 * recovers. It also marks the inode dirty, to catch the new size.
4527 *
4528 * Implication: the file must always be in a sane, consistent
4529 * truncatable state while each transaction commits.
4530 */
Mingming Cao617ba132006-10-11 01:20:53 -07004531 if (ext4_orphan_add(handle, inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004532 goto out_stop;
4533
4534 /*
Mingming Cao632eaea2008-07-11 19:27:31 -04004535 * From here we block out all ext4_get_block() callers who want to
4536 * modify the block allocation tree.
4537 */
4538 down_write(&ei->i_data_sem);
Theodore Ts'ob4df2032008-08-13 21:44:34 -04004539
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04004540 ext4_discard_preallocations(inode);
Theodore Ts'ob4df2032008-08-13 21:44:34 -04004541
Mingming Cao632eaea2008-07-11 19:27:31 -04004542 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004543 * The orphan list entry will now protect us from any crash which
4544 * occurs before the truncate completes, so it is now safe to propagate
4545 * the new, shorter inode size (held for now in i_size) into the
4546 * on-disk inode. We do this via i_disksize, which is the value which
Mingming Cao617ba132006-10-11 01:20:53 -07004547 * ext4 *really* writes onto the disk inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004548 */
4549 ei->i_disksize = inode->i_size;
4550
Kazuya Miof80da1e2011-04-10 22:06:36 -04004551 if (last_block == max_block) {
4552 /*
4553 * It is unnecessary to free any data blocks if last_block is
4554 * equal to the indirect block limit.
4555 */
4556 goto out_unlock;
4557 } else if (n == 1) { /* direct blocks */
Mingming Cao617ba132006-10-11 01:20:53 -07004558 ext4_free_data(handle, inode, NULL, i_data+offsets[0],
4559 i_data + EXT4_NDIR_BLOCKS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004560 goto do_indirects;
4561 }
4562
Mingming Cao617ba132006-10-11 01:20:53 -07004563 partial = ext4_find_shared(inode, n, offsets, chain, &nr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004564 /* Kill the top of shared branch (not detached) */
4565 if (nr) {
4566 if (partial == chain) {
4567 /* Shared branch grows from the inode */
Mingming Cao617ba132006-10-11 01:20:53 -07004568 ext4_free_branches(handle, inode, NULL,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004569 &nr, &nr+1, (chain+n-1) - partial);
4570 *partial->p = 0;
4571 /*
4572 * We mark the inode dirty prior to restart,
4573 * and prior to stop. No need for it here.
4574 */
4575 } else {
4576 /* Shared branch grows from an indirect block */
4577 BUFFER_TRACE(partial->bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07004578 ext4_free_branches(handle, inode, partial->bh,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004579 partial->p,
4580 partial->p+1, (chain+n-1) - partial);
4581 }
4582 }
4583 /* Clear the ends of indirect blocks on the shared branch */
4584 while (partial > chain) {
Mingming Cao617ba132006-10-11 01:20:53 -07004585 ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004586 (__le32*)partial->bh->b_data+addr_per_block,
4587 (chain+n-1) - partial);
4588 BUFFER_TRACE(partial->bh, "call brelse");
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004589 brelse(partial->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004590 partial--;
4591 }
4592do_indirects:
4593 /* Kill the remaining (whole) subtrees */
4594 switch (offsets[0]) {
4595 default:
Mingming Cao617ba132006-10-11 01:20:53 -07004596 nr = i_data[EXT4_IND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004597 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004598 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
4599 i_data[EXT4_IND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004600 }
Mingming Cao617ba132006-10-11 01:20:53 -07004601 case EXT4_IND_BLOCK:
4602 nr = i_data[EXT4_DIND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004603 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004604 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
4605 i_data[EXT4_DIND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004606 }
Mingming Cao617ba132006-10-11 01:20:53 -07004607 case EXT4_DIND_BLOCK:
4608 nr = i_data[EXT4_TIND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004609 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004610 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
4611 i_data[EXT4_TIND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004612 }
Mingming Cao617ba132006-10-11 01:20:53 -07004613 case EXT4_TIND_BLOCK:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004614 ;
4615 }
4616
Kazuya Miof80da1e2011-04-10 22:06:36 -04004617out_unlock:
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05004618 up_write(&ei->i_data_sem);
Kalpak Shahef7f3832007-07-18 09:15:20 -04004619 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
Mingming Cao617ba132006-10-11 01:20:53 -07004620 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004621
4622 /*
4623 * In a multi-transaction truncate, we only make the final transaction
4624 * synchronous
4625 */
4626 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -05004627 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004628out_stop:
4629 /*
4630 * If this was a simple ftruncate(), and the file will remain alive
4631 * then we need to clear up the orphan record which we created above.
4632 * However, if this was a real unlink then we were called by
Mingming Cao617ba132006-10-11 01:20:53 -07004633 * ext4_delete_inode(), and we allow that function to clean up the
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004634 * orphan info for us.
4635 */
4636 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07004637 ext4_orphan_del(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004638
Mingming Cao617ba132006-10-11 01:20:53 -07004639 ext4_journal_stop(handle);
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04004640 trace_ext4_truncate_exit(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004641}
4642
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004643/*
Mingming Cao617ba132006-10-11 01:20:53 -07004644 * ext4_get_inode_loc returns with an extra refcount against the inode's
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004645 * underlying buffer_head on success. If 'in_mem' is true, we have all
4646 * data in memory that is needed to recreate the on-disk version of this
4647 * inode.
4648 */
Mingming Cao617ba132006-10-11 01:20:53 -07004649static int __ext4_get_inode_loc(struct inode *inode,
4650 struct ext4_iloc *iloc, int in_mem)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004651{
Theodore Ts'o240799c2008-10-09 23:53:47 -04004652 struct ext4_group_desc *gdp;
4653 struct buffer_head *bh;
4654 struct super_block *sb = inode->i_sb;
4655 ext4_fsblk_t block;
4656 int inodes_per_block, inode_offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004657
Aneesh Kumar K.V3a06d772008-11-22 15:04:59 -05004658 iloc->bh = NULL;
Theodore Ts'o240799c2008-10-09 23:53:47 -04004659 if (!ext4_valid_inum(sb, inode->i_ino))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004660 return -EIO;
4661
Theodore Ts'o240799c2008-10-09 23:53:47 -04004662 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
4663 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
4664 if (!gdp)
4665 return -EIO;
4666
4667 /*
4668 * Figure out the offset within the block group inode table
4669 */
Tao Ma00d09882011-05-09 10:26:41 -04004670 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
Theodore Ts'o240799c2008-10-09 23:53:47 -04004671 inode_offset = ((inode->i_ino - 1) %
4672 EXT4_INODES_PER_GROUP(sb));
4673 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
4674 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
4675
4676 bh = sb_getblk(sb, block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004677 if (!bh) {
Theodore Ts'oc398eda2010-07-27 11:56:40 -04004678 EXT4_ERROR_INODE_BLOCK(inode, block,
4679 "unable to read itable block");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004680 return -EIO;
4681 }
4682 if (!buffer_uptodate(bh)) {
4683 lock_buffer(bh);
Hidehiro Kawai9c83a922008-07-26 16:39:26 -04004684
4685 /*
4686 * If the buffer has the write error flag, we have failed
4687 * to write out another inode in the same block. In this
4688 * case, we don't have to read the block because we may
4689 * read the old inode data successfully.
4690 */
4691 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
4692 set_buffer_uptodate(bh);
4693
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004694 if (buffer_uptodate(bh)) {
4695 /* someone brought it uptodate while we waited */
4696 unlock_buffer(bh);
4697 goto has_buffer;
4698 }
4699
4700 /*
4701 * If we have all information of the inode in memory and this
4702 * is the only valid inode in the block, we need not read the
4703 * block.
4704 */
4705 if (in_mem) {
4706 struct buffer_head *bitmap_bh;
Theodore Ts'o240799c2008-10-09 23:53:47 -04004707 int i, start;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004708
Theodore Ts'o240799c2008-10-09 23:53:47 -04004709 start = inode_offset & ~(inodes_per_block - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004710
4711 /* Is the inode bitmap in cache? */
Theodore Ts'o240799c2008-10-09 23:53:47 -04004712 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004713 if (!bitmap_bh)
4714 goto make_io;
4715
4716 /*
4717 * If the inode bitmap isn't in cache then the
4718 * optimisation may end up performing two reads instead
4719 * of one, so skip it.
4720 */
4721 if (!buffer_uptodate(bitmap_bh)) {
4722 brelse(bitmap_bh);
4723 goto make_io;
4724 }
Theodore Ts'o240799c2008-10-09 23:53:47 -04004725 for (i = start; i < start + inodes_per_block; i++) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004726 if (i == inode_offset)
4727 continue;
Mingming Cao617ba132006-10-11 01:20:53 -07004728 if (ext4_test_bit(i, bitmap_bh->b_data))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004729 break;
4730 }
4731 brelse(bitmap_bh);
Theodore Ts'o240799c2008-10-09 23:53:47 -04004732 if (i == start + inodes_per_block) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004733 /* all other inodes are free, so skip I/O */
4734 memset(bh->b_data, 0, bh->b_size);
4735 set_buffer_uptodate(bh);
4736 unlock_buffer(bh);
4737 goto has_buffer;
4738 }
4739 }
4740
4741make_io:
4742 /*
Theodore Ts'o240799c2008-10-09 23:53:47 -04004743 * If we need to do any I/O, try to pre-readahead extra
4744 * blocks from the inode table.
4745 */
4746 if (EXT4_SB(sb)->s_inode_readahead_blks) {
4747 ext4_fsblk_t b, end, table;
4748 unsigned num;
4749
4750 table = ext4_inode_table(sb, gdp);
Theodore Ts'ob713a5e2009-03-31 09:11:14 -04004751 /* s_inode_readahead_blks is always a power of 2 */
Theodore Ts'o240799c2008-10-09 23:53:47 -04004752 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
4753 if (table > b)
4754 b = table;
4755 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
4756 num = EXT4_INODES_PER_GROUP(sb);
4757 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4758 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
Aneesh Kumar K.V560671a2009-01-05 22:20:24 -05004759 num -= ext4_itable_unused_count(sb, gdp);
Theodore Ts'o240799c2008-10-09 23:53:47 -04004760 table += num / inodes_per_block;
4761 if (end > table)
4762 end = table;
4763 while (b <= end)
4764 sb_breadahead(sb, b++);
4765 }
4766
4767 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004768 * There are other valid inodes in the buffer, this inode
4769 * has in-inode xattrs, or we don't have this inode in memory.
4770 * Read the block from disk.
4771 */
Jiaying Zhang0562e0b2011-03-21 21:38:05 -04004772 trace_ext4_load_inode(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004773 get_bh(bh);
4774 bh->b_end_io = end_buffer_read_sync;
4775 submit_bh(READ_META, bh);
4776 wait_on_buffer(bh);
4777 if (!buffer_uptodate(bh)) {
Theodore Ts'oc398eda2010-07-27 11:56:40 -04004778 EXT4_ERROR_INODE_BLOCK(inode, block,
4779 "unable to read itable block");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004780 brelse(bh);
4781 return -EIO;
4782 }
4783 }
4784has_buffer:
4785 iloc->bh = bh;
4786 return 0;
4787}
4788
Mingming Cao617ba132006-10-11 01:20:53 -07004789int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004790{
4791 /* We have all inode data except xattrs in memory here. */
Mingming Cao617ba132006-10-11 01:20:53 -07004792 return __ext4_get_inode_loc(inode, iloc,
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05004793 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004794}
4795
Mingming Cao617ba132006-10-11 01:20:53 -07004796void ext4_set_inode_flags(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004797{
Mingming Cao617ba132006-10-11 01:20:53 -07004798 unsigned int flags = EXT4_I(inode)->i_flags;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004799
4800 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
Mingming Cao617ba132006-10-11 01:20:53 -07004801 if (flags & EXT4_SYNC_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004802 inode->i_flags |= S_SYNC;
Mingming Cao617ba132006-10-11 01:20:53 -07004803 if (flags & EXT4_APPEND_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004804 inode->i_flags |= S_APPEND;
Mingming Cao617ba132006-10-11 01:20:53 -07004805 if (flags & EXT4_IMMUTABLE_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004806 inode->i_flags |= S_IMMUTABLE;
Mingming Cao617ba132006-10-11 01:20:53 -07004807 if (flags & EXT4_NOATIME_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004808 inode->i_flags |= S_NOATIME;
Mingming Cao617ba132006-10-11 01:20:53 -07004809 if (flags & EXT4_DIRSYNC_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004810 inode->i_flags |= S_DIRSYNC;
4811}
4812
Jan Karaff9ddf72007-07-18 09:24:20 -04004813/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4814void ext4_get_inode_flags(struct ext4_inode_info *ei)
4815{
Dmitry Monakhov84a8dce2010-06-05 11:51:27 -04004816 unsigned int vfs_fl;
4817 unsigned long old_fl, new_fl;
Jan Karaff9ddf72007-07-18 09:24:20 -04004818
Dmitry Monakhov84a8dce2010-06-05 11:51:27 -04004819 do {
4820 vfs_fl = ei->vfs_inode.i_flags;
4821 old_fl = ei->i_flags;
4822 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
4823 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
4824 EXT4_DIRSYNC_FL);
4825 if (vfs_fl & S_SYNC)
4826 new_fl |= EXT4_SYNC_FL;
4827 if (vfs_fl & S_APPEND)
4828 new_fl |= EXT4_APPEND_FL;
4829 if (vfs_fl & S_IMMUTABLE)
4830 new_fl |= EXT4_IMMUTABLE_FL;
4831 if (vfs_fl & S_NOATIME)
4832 new_fl |= EXT4_NOATIME_FL;
4833 if (vfs_fl & S_DIRSYNC)
4834 new_fl |= EXT4_DIRSYNC_FL;
4835 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
Jan Karaff9ddf72007-07-18 09:24:20 -04004836}
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004837
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004838static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004839 struct ext4_inode_info *ei)
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004840{
4841 blkcnt_t i_blocks ;
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004842 struct inode *inode = &(ei->vfs_inode);
4843 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004844
4845 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4846 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
4847 /* we are using combined 48 bit field */
4848 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
4849 le32_to_cpu(raw_inode->i_blocks_lo);
Theodore Ts'o07a03822010-06-14 09:54:48 -04004850 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004851 /* i_blocks represent file system block size */
4852 return i_blocks << (inode->i_blkbits - 9);
4853 } else {
4854 return i_blocks;
4855 }
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004856 } else {
4857 return le32_to_cpu(raw_inode->i_blocks_lo);
4858 }
4859}
Jan Karaff9ddf72007-07-18 09:24:20 -04004860
David Howells1d1fe1e2008-02-07 00:15:37 -08004861struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004862{
Mingming Cao617ba132006-10-11 01:20:53 -07004863 struct ext4_iloc iloc;
4864 struct ext4_inode *raw_inode;
David Howells1d1fe1e2008-02-07 00:15:37 -08004865 struct ext4_inode_info *ei;
David Howells1d1fe1e2008-02-07 00:15:37 -08004866 struct inode *inode;
Jan Karab436b9b2009-12-08 23:51:10 -05004867 journal_t *journal = EXT4_SB(sb)->s_journal;
David Howells1d1fe1e2008-02-07 00:15:37 -08004868 long ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004869 int block;
4870
David Howells1d1fe1e2008-02-07 00:15:37 -08004871 inode = iget_locked(sb, ino);
4872 if (!inode)
4873 return ERR_PTR(-ENOMEM);
4874 if (!(inode->i_state & I_NEW))
4875 return inode;
4876
4877 ei = EXT4_I(inode);
Peter Huewe7dc57612011-02-21 21:01:42 -05004878 iloc.bh = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004879
David Howells1d1fe1e2008-02-07 00:15:37 -08004880 ret = __ext4_get_inode_loc(inode, &iloc, 0);
4881 if (ret < 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004882 goto bad_inode;
Mingming Cao617ba132006-10-11 01:20:53 -07004883 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004884 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4885 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4886 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004887 if (!(test_opt(inode->i_sb, NO_UID32))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004888 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4889 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4890 }
4891 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004892
Theodore Ts'o353eb832011-01-10 12:18:25 -05004893 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004894 ei->i_dir_start_lookup = 0;
4895 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4896 /* We now have enough fields to check if the inode was active or not.
4897 * This is needed because nfsd might try to access dead inodes
4898 * the test is that same one that e2fsck uses
4899 * NeilBrown 1999oct15
4900 */
4901 if (inode->i_nlink == 0) {
4902 if (inode->i_mode == 0 ||
Mingming Cao617ba132006-10-11 01:20:53 -07004903 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004904 /* this inode is deleted */
David Howells1d1fe1e2008-02-07 00:15:37 -08004905 ret = -ESTALE;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004906 goto bad_inode;
4907 }
4908 /* The only unlinked inodes we let through here have
4909 * valid i_mode and are being read by the orphan
4910 * recovery code: that's fine, we're about to complete
4911 * the process of deleting those. */
4912 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004913 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004914 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
Aneesh Kumar K.V7973c0c2008-01-28 23:58:27 -05004915 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
Theodore Ts'oa9e81742009-04-24 16:11:18 -04004916 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
Badari Pulavartya1ddeb72006-10-11 01:21:09 -07004917 ei->i_file_acl |=
4918 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004919 inode->i_size = ext4_isize(raw_inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004920 ei->i_disksize = inode->i_size;
Dmitry Monakhova9e7f442009-12-14 15:21:14 +03004921#ifdef CONFIG_QUOTA
4922 ei->i_reserved_quota = 0;
4923#endif
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004924 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4925 ei->i_block_group = iloc.block_group;
Theodore Ts'oa4912122009-03-12 12:18:34 -04004926 ei->i_last_alloc_group = ~0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004927 /*
4928 * NOTE! The in-memory inode i_data array is in little-endian order
4929 * even on big-endian machines: we do NOT byteswap the block numbers!
4930 */
Mingming Cao617ba132006-10-11 01:20:53 -07004931 for (block = 0; block < EXT4_N_BLOCKS; block++)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004932 ei->i_data[block] = raw_inode->i_block[block];
4933 INIT_LIST_HEAD(&ei->i_orphan);
4934
Jan Karab436b9b2009-12-08 23:51:10 -05004935 /*
4936 * Set transaction id's of transactions that have to be committed
4937 * to finish f[data]sync. We set them to currently running transaction
4938 * as we cannot be sure that the inode or some of its metadata isn't
4939 * part of the transaction - the inode could have been reclaimed and
4940 * now it is reread from disk.
4941 */
4942 if (journal) {
4943 transaction_t *transaction;
4944 tid_t tid;
4945
Theodore Ts'oa931da62010-08-03 21:35:12 -04004946 read_lock(&journal->j_state_lock);
Jan Karab436b9b2009-12-08 23:51:10 -05004947 if (journal->j_running_transaction)
4948 transaction = journal->j_running_transaction;
4949 else
4950 transaction = journal->j_committing_transaction;
4951 if (transaction)
4952 tid = transaction->t_tid;
4953 else
4954 tid = journal->j_commit_sequence;
Theodore Ts'oa931da62010-08-03 21:35:12 -04004955 read_unlock(&journal->j_state_lock);
Jan Karab436b9b2009-12-08 23:51:10 -05004956 ei->i_sync_tid = tid;
4957 ei->i_datasync_tid = tid;
4958 }
4959
Eric Sandeen0040d982008-02-05 22:36:43 -05004960 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004961 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
Mingming Cao617ba132006-10-11 01:20:53 -07004962 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
Kirill Korotaeve5d28612007-06-23 17:16:51 -07004963 EXT4_INODE_SIZE(inode->i_sb)) {
David Howells1d1fe1e2008-02-07 00:15:37 -08004964 ret = -EIO;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004965 goto bad_inode;
Kirill Korotaeve5d28612007-06-23 17:16:51 -07004966 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004967 if (ei->i_extra_isize == 0) {
4968 /* The extra space is currently unused. Use it. */
Mingming Cao617ba132006-10-11 01:20:53 -07004969 ei->i_extra_isize = sizeof(struct ext4_inode) -
4970 EXT4_GOOD_OLD_INODE_SIZE;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004971 } else {
4972 __le32 *magic = (void *)raw_inode +
Mingming Cao617ba132006-10-11 01:20:53 -07004973 EXT4_GOOD_OLD_INODE_SIZE +
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004974 ei->i_extra_isize;
Mingming Cao617ba132006-10-11 01:20:53 -07004975 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05004976 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004977 }
4978 } else
4979 ei->i_extra_isize = 0;
4980
Kalpak Shahef7f3832007-07-18 09:15:20 -04004981 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
4982 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
4983 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
4984 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4985
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004986 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
4987 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4988 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4989 inode->i_version |=
4990 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4991 }
4992
Theodore Ts'oc4b5a612009-04-24 18:45:35 -04004993 ret = 0;
Theodore Ts'o485c26e2009-04-24 13:43:20 -04004994 if (ei->i_file_acl &&
Theodore Ts'o10329882009-11-15 15:29:56 -05004995 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
Theodore Ts'o24676da2010-05-16 21:00:00 -04004996 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
4997 ei->i_file_acl);
Theodore Ts'o485c26e2009-04-24 13:43:20 -04004998 ret = -EIO;
4999 goto bad_inode;
Theodore Ts'o07a03822010-06-14 09:54:48 -04005000 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
Theodore Ts'oc4b5a612009-04-24 18:45:35 -04005001 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
5002 (S_ISLNK(inode->i_mode) &&
5003 !ext4_inode_is_fast_symlink(inode)))
5004 /* Validate extent which is part of inode */
5005 ret = ext4_ext_check_inode(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04005006 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
Thiemo Nagelfe2c8192009-03-31 08:36:10 -04005007 (S_ISLNK(inode->i_mode) &&
5008 !ext4_inode_is_fast_symlink(inode))) {
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04005009 /* Validate block references which are part of inode */
Thiemo Nagelfe2c8192009-03-31 08:36:10 -04005010 ret = ext4_check_inode_blockref(inode);
5011 }
Theodore Ts'o567f3e92009-11-14 08:19:05 -05005012 if (ret)
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04005013 goto bad_inode;
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -04005014
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005015 if (S_ISREG(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07005016 inode->i_op = &ext4_file_inode_operations;
5017 inode->i_fop = &ext4_file_operations;
5018 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005019 } else if (S_ISDIR(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07005020 inode->i_op = &ext4_dir_inode_operations;
5021 inode->i_fop = &ext4_dir_operations;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005022 } else if (S_ISLNK(inode->i_mode)) {
Duane Griffine83c1392008-12-19 20:47:15 +00005023 if (ext4_inode_is_fast_symlink(inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07005024 inode->i_op = &ext4_fast_symlink_inode_operations;
Duane Griffine83c1392008-12-19 20:47:15 +00005025 nd_terminate_link(ei->i_data, inode->i_size,
5026 sizeof(ei->i_data) - 1);
5027 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07005028 inode->i_op = &ext4_symlink_inode_operations;
5029 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005030 }
Theodore Ts'o563bdd62009-03-26 00:06:19 -04005031 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
5032 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07005033 inode->i_op = &ext4_special_inode_operations;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005034 if (raw_inode->i_block[0])
5035 init_special_inode(inode, inode->i_mode,
5036 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
5037 else
5038 init_special_inode(inode, inode->i_mode,
5039 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
Theodore Ts'o563bdd62009-03-26 00:06:19 -04005040 } else {
Theodore Ts'o563bdd62009-03-26 00:06:19 -04005041 ret = -EIO;
Theodore Ts'o24676da2010-05-16 21:00:00 -04005042 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
Theodore Ts'o563bdd62009-03-26 00:06:19 -04005043 goto bad_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005044 }
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04005045 brelse(iloc.bh);
Mingming Cao617ba132006-10-11 01:20:53 -07005046 ext4_set_inode_flags(inode);
David Howells1d1fe1e2008-02-07 00:15:37 -08005047 unlock_new_inode(inode);
5048 return inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005049
5050bad_inode:
Theodore Ts'o567f3e92009-11-14 08:19:05 -05005051 brelse(iloc.bh);
David Howells1d1fe1e2008-02-07 00:15:37 -08005052 iget_failed(inode);
5053 return ERR_PTR(ret);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005054}
5055
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005056static int ext4_inode_blocks_set(handle_t *handle,
5057 struct ext4_inode *raw_inode,
5058 struct ext4_inode_info *ei)
5059{
5060 struct inode *inode = &(ei->vfs_inode);
5061 u64 i_blocks = inode->i_blocks;
5062 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005063
5064 if (i_blocks <= ~0U) {
5065 /*
5066 * i_blocks can be represnted in a 32 bit variable
5067 * as multiple of 512 bytes
5068 */
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05005069 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005070 raw_inode->i_blocks_high = 0;
Dmitry Monakhov84a8dce2010-06-05 11:51:27 -04005071 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
Theodore Ts'of287a1a2008-10-16 22:50:48 -04005072 return 0;
5073 }
5074 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
5075 return -EFBIG;
5076
5077 if (i_blocks <= 0xffffffffffffULL) {
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005078 /*
5079 * i_blocks can be represented in a 48 bit variable
5080 * as multiple of 512 bytes
5081 */
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05005082 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005083 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
Dmitry Monakhov84a8dce2010-06-05 11:51:27 -04005084 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005085 } else {
Dmitry Monakhov84a8dce2010-06-05 11:51:27 -04005086 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05005087 /* i_block is stored in file system block size */
5088 i_blocks = i_blocks >> (inode->i_blkbits - 9);
5089 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
5090 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005091 }
Theodore Ts'of287a1a2008-10-16 22:50:48 -04005092 return 0;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005093}
5094
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005095/*
5096 * Post the struct inode info into an on-disk inode location in the
5097 * buffer-cache. This gobbles the caller's reference to the
5098 * buffer_head in the inode location struct.
5099 *
5100 * The caller must have write access to iloc->bh.
5101 */
Mingming Cao617ba132006-10-11 01:20:53 -07005102static int ext4_do_update_inode(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005103 struct inode *inode,
Frank Mayhar830156c2009-09-29 10:07:47 -04005104 struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005105{
Mingming Cao617ba132006-10-11 01:20:53 -07005106 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
5107 struct ext4_inode_info *ei = EXT4_I(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005108 struct buffer_head *bh = iloc->bh;
5109 int err = 0, rc, block;
5110
5111 /* For fields not not tracking in the in-memory inode,
5112 * initialise them to zero for new inodes. */
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05005113 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
Mingming Cao617ba132006-10-11 01:20:53 -07005114 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005115
Jan Karaff9ddf72007-07-18 09:24:20 -04005116 ext4_get_inode_flags(ei);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005117 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04005118 if (!(test_opt(inode->i_sb, NO_UID32))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005119 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
5120 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
5121/*
5122 * Fix up interoperability with old kernels. Otherwise, old inodes get
5123 * re-used with the upper 16 bits of the uid/gid intact
5124 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04005125 if (!ei->i_dtime) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005126 raw_inode->i_uid_high =
5127 cpu_to_le16(high_16_bits(inode->i_uid));
5128 raw_inode->i_gid_high =
5129 cpu_to_le16(high_16_bits(inode->i_gid));
5130 } else {
5131 raw_inode->i_uid_high = 0;
5132 raw_inode->i_gid_high = 0;
5133 }
5134 } else {
5135 raw_inode->i_uid_low =
5136 cpu_to_le16(fs_high2lowuid(inode->i_uid));
5137 raw_inode->i_gid_low =
5138 cpu_to_le16(fs_high2lowgid(inode->i_gid));
5139 raw_inode->i_uid_high = 0;
5140 raw_inode->i_gid_high = 0;
5141 }
5142 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
Kalpak Shahef7f3832007-07-18 09:15:20 -04005143
5144 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
5145 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
5146 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
5147 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
5148
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05005149 if (ext4_inode_blocks_set(handle, raw_inode, ei))
5150 goto out_brelse;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005151 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
Theodore Ts'o353eb832011-01-10 12:18:25 -05005152 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
Mingming Cao9b8f1f02006-10-11 01:21:13 -07005153 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
5154 cpu_to_le32(EXT4_OS_HURD))
Badari Pulavartya1ddeb72006-10-11 01:21:09 -07005155 raw_inode->i_file_acl_high =
5156 cpu_to_le16(ei->i_file_acl >> 32);
Aneesh Kumar K.V7973c0c2008-01-28 23:58:27 -05005157 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05005158 ext4_isize_set(raw_inode, ei->i_disksize);
5159 if (ei->i_disksize > 0x7fffffffULL) {
5160 struct super_block *sb = inode->i_sb;
5161 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
5162 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
5163 EXT4_SB(sb)->s_es->s_rev_level ==
5164 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
5165 /* If this is the first large file
5166 * created, add a flag to the superblock.
5167 */
5168 err = ext4_journal_get_write_access(handle,
5169 EXT4_SB(sb)->s_sbh);
5170 if (err)
5171 goto out_brelse;
5172 ext4_update_dynamic_rev(sb);
5173 EXT4_SET_RO_COMPAT_FEATURE(sb,
Mingming Cao617ba132006-10-11 01:20:53 -07005174 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05005175 sb->s_dirt = 1;
Frank Mayhar03901312009-01-07 00:06:22 -05005176 ext4_handle_sync(handle);
Curt Wohlgemuth73b50c12010-02-16 15:06:29 -05005177 err = ext4_handle_dirty_metadata(handle, NULL,
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05005178 EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005179 }
5180 }
5181 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
5182 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
5183 if (old_valid_dev(inode->i_rdev)) {
5184 raw_inode->i_block[0] =
5185 cpu_to_le32(old_encode_dev(inode->i_rdev));
5186 raw_inode->i_block[1] = 0;
5187 } else {
5188 raw_inode->i_block[0] = 0;
5189 raw_inode->i_block[1] =
5190 cpu_to_le32(new_encode_dev(inode->i_rdev));
5191 raw_inode->i_block[2] = 0;
5192 }
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04005193 } else
5194 for (block = 0; block < EXT4_N_BLOCKS; block++)
5195 raw_inode->i_block[block] = ei->i_data[block];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005196
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05005197 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
5198 if (ei->i_extra_isize) {
5199 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
5200 raw_inode->i_version_hi =
5201 cpu_to_le32(inode->i_version >> 32);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005202 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05005203 }
5204
Frank Mayhar830156c2009-09-29 10:07:47 -04005205 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
Curt Wohlgemuth73b50c12010-02-16 15:06:29 -05005206 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
Frank Mayhar830156c2009-09-29 10:07:47 -04005207 if (!err)
5208 err = rc;
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05005209 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005210
Jan Karab436b9b2009-12-08 23:51:10 -05005211 ext4_update_inode_fsync_trans(handle, inode, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005212out_brelse:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04005213 brelse(bh);
Mingming Cao617ba132006-10-11 01:20:53 -07005214 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005215 return err;
5216}
5217
5218/*
Mingming Cao617ba132006-10-11 01:20:53 -07005219 * ext4_write_inode()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005220 *
5221 * We are called from a few places:
5222 *
5223 * - Within generic_file_write() for O_SYNC files.
5224 * Here, there will be no transaction running. We wait for any running
5225 * trasnaction to commit.
5226 *
5227 * - Within sys_sync(), kupdate and such.
5228 * We wait on commit, if tol to.
5229 *
5230 * - Within prune_icache() (PF_MEMALLOC == true)
5231 * Here we simply return. We can't afford to block kswapd on the
5232 * journal commit.
5233 *
5234 * In all cases it is actually safe for us to return without doing anything,
5235 * because the inode has been copied into a raw inode buffer in
Mingming Cao617ba132006-10-11 01:20:53 -07005236 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005237 * knfsd.
5238 *
5239 * Note that we are absolutely dependent upon all inode dirtiers doing the
5240 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5241 * which we are interested.
5242 *
5243 * It would be a bug for them to not do this. The code:
5244 *
5245 * mark_inode_dirty(inode)
5246 * stuff();
5247 * inode->i_size = expr;
5248 *
5249 * is in error because a kswapd-driven write_inode() could occur while
5250 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5251 * will no longer be on the superblock's dirty inode list.
5252 */
Christoph Hellwiga9185b42010-03-05 09:21:37 +01005253int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005254{
Frank Mayhar91ac6f42009-09-09 22:33:47 -04005255 int err;
5256
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005257 if (current->flags & PF_MEMALLOC)
5258 return 0;
5259
Frank Mayhar91ac6f42009-09-09 22:33:47 -04005260 if (EXT4_SB(inode->i_sb)->s_journal) {
5261 if (ext4_journal_current_handle()) {
5262 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5263 dump_stack();
5264 return -EIO;
5265 }
5266
Christoph Hellwiga9185b42010-03-05 09:21:37 +01005267 if (wbc->sync_mode != WB_SYNC_ALL)
Frank Mayhar91ac6f42009-09-09 22:33:47 -04005268 return 0;
5269
5270 err = ext4_force_commit(inode->i_sb);
5271 } else {
5272 struct ext4_iloc iloc;
5273
Curt Wohlgemuth8b472d72010-04-03 16:45:06 -04005274 err = __ext4_get_inode_loc(inode, &iloc, 0);
Frank Mayhar91ac6f42009-09-09 22:33:47 -04005275 if (err)
5276 return err;
Christoph Hellwiga9185b42010-03-05 09:21:37 +01005277 if (wbc->sync_mode == WB_SYNC_ALL)
Frank Mayhar830156c2009-09-29 10:07:47 -04005278 sync_dirty_buffer(iloc.bh);
5279 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
Theodore Ts'oc398eda2010-07-27 11:56:40 -04005280 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
5281 "IO error syncing inode");
Frank Mayhar830156c2009-09-29 10:07:47 -04005282 err = -EIO;
5283 }
Curt Wohlgemuthfd2dd9f2010-04-03 17:44:16 -04005284 brelse(iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005285 }
Frank Mayhar91ac6f42009-09-09 22:33:47 -04005286 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005287}
5288
5289/*
Mingming Cao617ba132006-10-11 01:20:53 -07005290 * ext4_setattr()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005291 *
5292 * Called from notify_change.
5293 *
5294 * We want to trap VFS attempts to truncate the file as soon as
5295 * possible. In particular, we want to make sure that when the VFS
5296 * shrinks i_size, we put the inode on the orphan list and modify
5297 * i_disksize immediately, so that during the subsequent flushing of
5298 * dirty pages and freeing of disk blocks, we can guarantee that any
5299 * commit will leave the blocks being flushed in an unused state on
5300 * disk. (On recovery, the inode will get truncated and the blocks will
5301 * be freed, so we have a strong guarantee that no future commit will
5302 * leave these blocks visible to the user.)
5303 *
Jan Kara678aaf42008-07-11 19:27:31 -04005304 * Another thing we have to assure is that if we are in ordered mode
5305 * and inode is still attached to the committing transaction, we must
5306 * we start writeout of all the dirty pages which are being truncated.
5307 * This way we are sure that all the data written in the previous
5308 * transaction are already on disk (truncate waits for pages under
5309 * writeback).
5310 *
5311 * Called with inode->i_mutex down.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005312 */
Mingming Cao617ba132006-10-11 01:20:53 -07005313int ext4_setattr(struct dentry *dentry, struct iattr *attr)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005314{
5315 struct inode *inode = dentry->d_inode;
5316 int error, rc = 0;
Dmitry Monakhov3d287de2010-10-27 22:08:46 -04005317 int orphan = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005318 const unsigned int ia_valid = attr->ia_valid;
5319
5320 error = inode_change_ok(inode, attr);
5321 if (error)
5322 return error;
5323
Dmitry Monakhov12755622010-04-08 22:04:20 +04005324 if (is_quota_modification(inode, attr))
Christoph Hellwig871a2932010-03-03 09:05:07 -05005325 dquot_initialize(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005326 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
5327 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
5328 handle_t *handle;
5329
5330 /* (user+group)*(old+new) structure, inode write (sb,
5331 * inode block, ? - but truncate inode update has it) */
Dmitry Monakhov5aca07e2009-12-08 22:42:15 -05005332 handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
Dmitry Monakhov194074a2009-12-08 22:42:28 -05005333 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005334 if (IS_ERR(handle)) {
5335 error = PTR_ERR(handle);
5336 goto err_out;
5337 }
Christoph Hellwigb43fa822010-03-03 09:05:03 -05005338 error = dquot_transfer(inode, attr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005339 if (error) {
Mingming Cao617ba132006-10-11 01:20:53 -07005340 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005341 return error;
5342 }
5343 /* Update corresponding info in inode so that everything is in
5344 * one transaction */
5345 if (attr->ia_valid & ATTR_UID)
5346 inode->i_uid = attr->ia_uid;
5347 if (attr->ia_valid & ATTR_GID)
5348 inode->i_gid = attr->ia_gid;
Mingming Cao617ba132006-10-11 01:20:53 -07005349 error = ext4_mark_inode_dirty(handle, inode);
5350 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005351 }
5352
Eric Sandeene2b46572008-01-28 23:58:27 -05005353 if (attr->ia_valid & ATTR_SIZE) {
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04005354 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
Eric Sandeene2b46572008-01-28 23:58:27 -05005355 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5356
Theodore Ts'o0c095c72010-07-27 11:56:06 -04005357 if (attr->ia_size > sbi->s_bitmap_maxbytes)
5358 return -EFBIG;
Eric Sandeene2b46572008-01-28 23:58:27 -05005359 }
5360 }
5361
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005362 if (S_ISREG(inode->i_mode) &&
Jiaying Zhangc8d46e42010-02-24 09:52:53 -05005363 attr->ia_valid & ATTR_SIZE &&
Theodore Ts'o072bd7e2011-05-23 15:13:02 -04005364 (attr->ia_size < inode->i_size)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005365 handle_t *handle;
5366
Mingming Cao617ba132006-10-11 01:20:53 -07005367 handle = ext4_journal_start(inode, 3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005368 if (IS_ERR(handle)) {
5369 error = PTR_ERR(handle);
5370 goto err_out;
5371 }
Dmitry Monakhov3d287de2010-10-27 22:08:46 -04005372 if (ext4_handle_valid(handle)) {
5373 error = ext4_orphan_add(handle, inode);
5374 orphan = 1;
5375 }
Mingming Cao617ba132006-10-11 01:20:53 -07005376 EXT4_I(inode)->i_disksize = attr->ia_size;
5377 rc = ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005378 if (!error)
5379 error = rc;
Mingming Cao617ba132006-10-11 01:20:53 -07005380 ext4_journal_stop(handle);
Jan Kara678aaf42008-07-11 19:27:31 -04005381
5382 if (ext4_should_order_data(inode)) {
5383 error = ext4_begin_ordered_truncate(inode,
5384 attr->ia_size);
5385 if (error) {
5386 /* Do as much error cleanup as possible */
5387 handle = ext4_journal_start(inode, 3);
5388 if (IS_ERR(handle)) {
5389 ext4_orphan_del(NULL, inode);
5390 goto err_out;
5391 }
5392 ext4_orphan_del(handle, inode);
Dmitry Monakhov3d287de2010-10-27 22:08:46 -04005393 orphan = 0;
Jan Kara678aaf42008-07-11 19:27:31 -04005394 ext4_journal_stop(handle);
5395 goto err_out;
5396 }
5397 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005398 }
5399
Theodore Ts'o072bd7e2011-05-23 15:13:02 -04005400 if (attr->ia_valid & ATTR_SIZE) {
5401 if (attr->ia_size != i_size_read(inode)) {
5402 truncate_setsize(inode, attr->ia_size);
5403 ext4_truncate(inode);
5404 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
5405 ext4_truncate(inode);
5406 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005407
Christoph Hellwig10257742010-06-04 11:30:02 +02005408 if (!rc) {
5409 setattr_copy(inode, attr);
5410 mark_inode_dirty(inode);
5411 }
5412
5413 /*
5414 * If the call to ext4_truncate failed to get a transaction handle at
5415 * all, we need to clean up the in-core orphan list manually.
5416 */
Dmitry Monakhov3d287de2010-10-27 22:08:46 -04005417 if (orphan && inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07005418 ext4_orphan_del(NULL, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005419
5420 if (!rc && (ia_valid & ATTR_MODE))
Mingming Cao617ba132006-10-11 01:20:53 -07005421 rc = ext4_acl_chmod(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005422
5423err_out:
Mingming Cao617ba132006-10-11 01:20:53 -07005424 ext4_std_error(inode->i_sb, error);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005425 if (!error)
5426 error = rc;
5427 return error;
5428}
5429
Mingming Cao3e3398a2008-07-11 19:27:31 -04005430int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
5431 struct kstat *stat)
5432{
5433 struct inode *inode;
5434 unsigned long delalloc_blocks;
5435
5436 inode = dentry->d_inode;
5437 generic_fillattr(inode, stat);
5438
5439 /*
5440 * We can't update i_blocks if the block allocation is delayed
5441 * otherwise in the case of system crash before the real block
5442 * allocation is done, we will have i_blocks inconsistent with
5443 * on-disk file blocks.
5444 * We always keep i_blocks updated together with real
5445 * allocation. But to not confuse with user, stat
5446 * will return the blocks that include the delayed allocation
5447 * blocks for this file.
5448 */
Mingming Cao3e3398a2008-07-11 19:27:31 -04005449 delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
Mingming Cao3e3398a2008-07-11 19:27:31 -04005450
5451 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
5452 return 0;
5453}
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005454
Mingming Caoa02908f2008-08-19 22:16:07 -04005455static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
5456 int chunk)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005457{
Mingming Caoa02908f2008-08-19 22:16:07 -04005458 int indirects;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005459
Mingming Caoa02908f2008-08-19 22:16:07 -04005460 /* if nrblocks are contiguous */
5461 if (chunk) {
5462 /*
Yongqiang Yang5b413952011-04-04 15:40:24 -04005463 * With N contiguous data blocks, we need at most
5464 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
5465 * 2 dindirect blocks, and 1 tindirect block
Mingming Caoa02908f2008-08-19 22:16:07 -04005466 */
Yongqiang Yang5b413952011-04-04 15:40:24 -04005467 return DIV_ROUND_UP(nrblocks,
5468 EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
Mingming Caoa02908f2008-08-19 22:16:07 -04005469 }
5470 /*
5471 * if nrblocks are not contiguous, worse case, each block touch
5472 * a indirect block, and each indirect block touch a double indirect
5473 * block, plus a triple indirect block
5474 */
5475 indirects = nrblocks * 2 + 1;
5476 return indirects;
5477}
Alex Tomasa86c6182006-10-11 01:21:03 -07005478
Mingming Caoa02908f2008-08-19 22:16:07 -04005479static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
5480{
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04005481 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
Theodore Ts'oac51d832008-11-06 16:49:36 -05005482 return ext4_indirect_trans_blocks(inode, nrblocks, chunk);
5483 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
Mingming Caoa02908f2008-08-19 22:16:07 -04005484}
Theodore Ts'oac51d832008-11-06 16:49:36 -05005485
Mingming Caoa02908f2008-08-19 22:16:07 -04005486/*
5487 * Account for index blocks, block groups bitmaps and block group
5488 * descriptor blocks if modify datablocks and index blocks
5489 * worse case, the indexs blocks spread over different block groups
5490 *
5491 * If datablocks are discontiguous, they are possible to spread over
André Goddard Rosaaf901ca2009-11-14 13:09:05 -02005492 * different block groups too. If they are contiuguous, with flexbg,
Mingming Caoa02908f2008-08-19 22:16:07 -04005493 * they could still across block group boundary.
5494 *
5495 * Also account for superblock, inode, quota and xattr blocks
5496 */
Theodore Ts'o1f109d52010-10-27 21:30:14 -04005497static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
Mingming Caoa02908f2008-08-19 22:16:07 -04005498{
Theodore Ts'o8df96752009-05-01 08:50:38 -04005499 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
5500 int gdpblocks;
Mingming Caoa02908f2008-08-19 22:16:07 -04005501 int idxblocks;
5502 int ret = 0;
5503
5504 /*
5505 * How many index blocks need to touch to modify nrblocks?
5506 * The "Chunk" flag indicating whether the nrblocks is
5507 * physically contiguous on disk
5508 *
5509 * For Direct IO and fallocate, they calls get_block to allocate
5510 * one single extent at a time, so they could set the "Chunk" flag
5511 */
5512 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
5513
5514 ret = idxblocks;
5515
5516 /*
5517 * Now let's see how many group bitmaps and group descriptors need
5518 * to account
5519 */
5520 groups = idxblocks;
5521 if (chunk)
5522 groups += 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005523 else
Mingming Caoa02908f2008-08-19 22:16:07 -04005524 groups += nrblocks;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005525
Mingming Caoa02908f2008-08-19 22:16:07 -04005526 gdpblocks = groups;
Theodore Ts'o8df96752009-05-01 08:50:38 -04005527 if (groups > ngroups)
5528 groups = ngroups;
Mingming Caoa02908f2008-08-19 22:16:07 -04005529 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
5530 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
5531
5532 /* bitmaps and block group descriptor blocks */
5533 ret += groups + gdpblocks;
5534
5535 /* Blocks for super block, inode, quota and xattr blocks */
5536 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005537
5538 return ret;
5539}
5540
5541/*
Lucas De Marchi25985ed2011-03-30 22:57:33 -03005542 * Calculate the total number of credits to reserve to fit
Mingming Caof3bd1f32008-08-19 22:16:03 -04005543 * the modification of a single pages into a single transaction,
5544 * which may include multiple chunks of block allocations.
Mingming Caoa02908f2008-08-19 22:16:07 -04005545 *
Mingming Cao525f4ed2008-08-19 22:15:58 -04005546 * This could be called via ext4_write_begin()
Mingming Caoa02908f2008-08-19 22:16:07 -04005547 *
Mingming Cao525f4ed2008-08-19 22:15:58 -04005548 * We need to consider the worse case, when
Mingming Caoa02908f2008-08-19 22:16:07 -04005549 * one new block per extent.
Mingming Caoa02908f2008-08-19 22:16:07 -04005550 */
5551int ext4_writepage_trans_blocks(struct inode *inode)
5552{
5553 int bpp = ext4_journal_blocks_per_page(inode);
5554 int ret;
5555
5556 ret = ext4_meta_trans_blocks(inode, bpp, 0);
5557
5558 /* Account for data blocks for journalled mode */
5559 if (ext4_should_journal_data(inode))
5560 ret += bpp;
5561 return ret;
5562}
Mingming Caof3bd1f32008-08-19 22:16:03 -04005563
5564/*
5565 * Calculate the journal credits for a chunk of data modification.
5566 *
5567 * This is called from DIO, fallocate or whoever calling
Eric Sandeen79e83032010-07-27 11:56:07 -04005568 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
Mingming Caof3bd1f32008-08-19 22:16:03 -04005569 *
5570 * journal buffers for data blocks are not included here, as DIO
5571 * and fallocate do no need to journal data buffers.
5572 */
5573int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
5574{
5575 return ext4_meta_trans_blocks(inode, nrblocks, 1);
5576}
5577
Mingming Caoa02908f2008-08-19 22:16:07 -04005578/*
Mingming Cao617ba132006-10-11 01:20:53 -07005579 * The caller must have previously called ext4_reserve_inode_write().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005580 * Give this, we know that the caller already has write access to iloc->bh.
5581 */
Mingming Cao617ba132006-10-11 01:20:53 -07005582int ext4_mark_iloc_dirty(handle_t *handle,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04005583 struct inode *inode, struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005584{
5585 int err = 0;
5586
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05005587 if (test_opt(inode->i_sb, I_VERSION))
5588 inode_inc_iversion(inode);
5589
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005590 /* the do_update_inode consumes one bh->b_count */
5591 get_bh(iloc->bh);
5592
Mingming Caodab291a2006-10-11 01:21:01 -07005593 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
Frank Mayhar830156c2009-09-29 10:07:47 -04005594 err = ext4_do_update_inode(handle, inode, iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005595 put_bh(iloc->bh);
5596 return err;
5597}
5598
5599/*
5600 * On success, We end up with an outstanding reference count against
5601 * iloc->bh. This _must_ be cleaned up later.
5602 */
5603
5604int
Mingming Cao617ba132006-10-11 01:20:53 -07005605ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
5606 struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005607{
Frank Mayhar03901312009-01-07 00:06:22 -05005608 int err;
5609
5610 err = ext4_get_inode_loc(inode, iloc);
5611 if (!err) {
5612 BUFFER_TRACE(iloc->bh, "get_write_access");
5613 err = ext4_journal_get_write_access(handle, iloc->bh);
5614 if (err) {
5615 brelse(iloc->bh);
5616 iloc->bh = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005617 }
5618 }
Mingming Cao617ba132006-10-11 01:20:53 -07005619 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005620 return err;
5621}
5622
5623/*
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005624 * Expand an inode by new_extra_isize bytes.
5625 * Returns 0 on success or negative error number on failure.
5626 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05005627static int ext4_expand_extra_isize(struct inode *inode,
5628 unsigned int new_extra_isize,
5629 struct ext4_iloc iloc,
5630 handle_t *handle)
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005631{
5632 struct ext4_inode *raw_inode;
5633 struct ext4_xattr_ibody_header *header;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005634
5635 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
5636 return 0;
5637
5638 raw_inode = ext4_raw_inode(&iloc);
5639
5640 header = IHDR(inode, raw_inode);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005641
5642 /* No extended attributes present */
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05005643 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
5644 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005645 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
5646 new_extra_isize);
5647 EXT4_I(inode)->i_extra_isize = new_extra_isize;
5648 return 0;
5649 }
5650
5651 /* try to expand with EAs present */
5652 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
5653 raw_inode, handle);
5654}
5655
5656/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005657 * What we do here is to mark the in-core inode as clean with respect to inode
5658 * dirtiness (it may still be data-dirty).
5659 * This means that the in-core inode may be reaped by prune_icache
5660 * without having to perform any I/O. This is a very good thing,
5661 * because *any* task may call prune_icache - even ones which
5662 * have a transaction open against a different journal.
5663 *
5664 * Is this cheating? Not really. Sure, we haven't written the
5665 * inode out, but prune_icache isn't a user-visible syncing function.
5666 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5667 * we start and wait on commits.
5668 *
5669 * Is this efficient/effective? Well, we're being nice to the system
5670 * by cleaning up our inodes proactively so they can be reaped
5671 * without I/O. But we are potentially leaving up to five seconds'
5672 * worth of inodes floating about which prune_icache wants us to
5673 * write out. One way to fix that would be to get prune_icache()
5674 * to do a write_super() to free up some memory. It has the desired
5675 * effect.
5676 */
Mingming Cao617ba132006-10-11 01:20:53 -07005677int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005678{
Mingming Cao617ba132006-10-11 01:20:53 -07005679 struct ext4_iloc iloc;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005680 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5681 static unsigned int mnt_count;
5682 int err, ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005683
5684 might_sleep();
Theodore Ts'o7ff9c072010-11-08 13:51:33 -05005685 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
Mingming Cao617ba132006-10-11 01:20:53 -07005686 err = ext4_reserve_inode_write(handle, inode, &iloc);
Frank Mayhar03901312009-01-07 00:06:22 -05005687 if (ext4_handle_valid(handle) &&
5688 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05005689 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005690 /*
5691 * We need extra buffer credits since we may write into EA block
5692 * with this same handle. If journal_extend fails, then it will
5693 * only result in a minor loss of functionality for that inode.
5694 * If this is felt to be critical, then e2fsck should be run to
5695 * force a large enough s_min_extra_isize.
5696 */
5697 if ((jbd2_journal_extend(handle,
5698 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
5699 ret = ext4_expand_extra_isize(inode,
5700 sbi->s_want_extra_isize,
5701 iloc, handle);
5702 if (ret) {
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05005703 ext4_set_inode_state(inode,
5704 EXT4_STATE_NO_EXPAND);
Aneesh Kumar K.Vc1bddad2007-10-16 18:38:25 -04005705 if (mnt_count !=
5706 le16_to_cpu(sbi->s_es->s_mnt_count)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05005707 ext4_warning(inode->i_sb,
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005708 "Unable to expand inode %lu. Delete"
5709 " some EAs or run e2fsck.",
5710 inode->i_ino);
Aneesh Kumar K.Vc1bddad2007-10-16 18:38:25 -04005711 mnt_count =
5712 le16_to_cpu(sbi->s_es->s_mnt_count);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005713 }
5714 }
5715 }
5716 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005717 if (!err)
Mingming Cao617ba132006-10-11 01:20:53 -07005718 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005719 return err;
5720}
5721
5722/*
Mingming Cao617ba132006-10-11 01:20:53 -07005723 * ext4_dirty_inode() is called from __mark_inode_dirty()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005724 *
5725 * We're really interested in the case where a file is being extended.
5726 * i_size has been changed by generic_commit_write() and we thus need
5727 * to include the updated inode in the current transaction.
5728 *
Christoph Hellwig5dd40562010-03-03 09:05:00 -05005729 * Also, dquot_alloc_block() will always dirty the inode when blocks
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005730 * are allocated to the file.
5731 *
5732 * If the inode is marked synchronous, we don't honour that here - doing
5733 * so would cause a commit on atime updates, which we don't bother doing.
5734 * We handle synchronous inodes at the highest possible level.
5735 */
Mingming Cao617ba132006-10-11 01:20:53 -07005736void ext4_dirty_inode(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005737{
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005738 handle_t *handle;
5739
Mingming Cao617ba132006-10-11 01:20:53 -07005740 handle = ext4_journal_start(inode, 2);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005741 if (IS_ERR(handle))
5742 goto out;
Curt Wohlgemuthf3dc2722009-09-29 16:06:01 -04005743
Curt Wohlgemuthf3dc2722009-09-29 16:06:01 -04005744 ext4_mark_inode_dirty(handle, inode);
5745
Mingming Cao617ba132006-10-11 01:20:53 -07005746 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005747out:
5748 return;
5749}
5750
5751#if 0
5752/*
5753 * Bind an inode's backing buffer_head into this transaction, to prevent
5754 * it from being flushed to disk early. Unlike
Mingming Cao617ba132006-10-11 01:20:53 -07005755 * ext4_reserve_inode_write, this leaves behind no bh reference and
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005756 * returns no iloc structure, so the caller needs to repeat the iloc
5757 * lookup to mark the inode dirty later.
5758 */
Mingming Cao617ba132006-10-11 01:20:53 -07005759static int ext4_pin_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005760{
Mingming Cao617ba132006-10-11 01:20:53 -07005761 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005762
5763 int err = 0;
5764 if (handle) {
Mingming Cao617ba132006-10-11 01:20:53 -07005765 err = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005766 if (!err) {
5767 BUFFER_TRACE(iloc.bh, "get_write_access");
Mingming Caodab291a2006-10-11 01:21:01 -07005768 err = jbd2_journal_get_write_access(handle, iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005769 if (!err)
Frank Mayhar03901312009-01-07 00:06:22 -05005770 err = ext4_handle_dirty_metadata(handle,
Curt Wohlgemuth73b50c12010-02-16 15:06:29 -05005771 NULL,
Frank Mayhar03901312009-01-07 00:06:22 -05005772 iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005773 brelse(iloc.bh);
5774 }
5775 }
Mingming Cao617ba132006-10-11 01:20:53 -07005776 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005777 return err;
5778}
5779#endif
5780
Mingming Cao617ba132006-10-11 01:20:53 -07005781int ext4_change_inode_journal_flag(struct inode *inode, int val)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005782{
5783 journal_t *journal;
5784 handle_t *handle;
5785 int err;
5786
5787 /*
5788 * We have to be very careful here: changing a data block's
5789 * journaling status dynamically is dangerous. If we write a
5790 * data block to the journal, change the status and then delete
5791 * that block, we risk forgetting to revoke the old log record
5792 * from the journal and so a subsequent replay can corrupt data.
5793 * So, first we make sure that the journal is empty and that
5794 * nobody is changing anything.
5795 */
5796
Mingming Cao617ba132006-10-11 01:20:53 -07005797 journal = EXT4_JOURNAL(inode);
Frank Mayhar03901312009-01-07 00:06:22 -05005798 if (!journal)
5799 return 0;
Dave Hansend6995942007-07-18 08:33:51 -04005800 if (is_journal_aborted(journal))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005801 return -EROFS;
5802
Mingming Caodab291a2006-10-11 01:21:01 -07005803 jbd2_journal_lock_updates(journal);
5804 jbd2_journal_flush(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005805
5806 /*
5807 * OK, there are no updates running now, and all cached data is
5808 * synced to disk. We are now in a completely consistent state
5809 * which doesn't have anything in the journal, and we know that
5810 * no filesystem updates are running, so it is safe to modify
5811 * the inode's in-core data-journaling state flag now.
5812 */
5813
5814 if (val)
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04005815 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005816 else
Dmitry Monakhov12e9b892010-05-16 22:00:00 -04005817 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
Mingming Cao617ba132006-10-11 01:20:53 -07005818 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005819
Mingming Caodab291a2006-10-11 01:21:01 -07005820 jbd2_journal_unlock_updates(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005821
5822 /* Finally we can mark the inode as dirty. */
5823
Mingming Cao617ba132006-10-11 01:20:53 -07005824 handle = ext4_journal_start(inode, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005825 if (IS_ERR(handle))
5826 return PTR_ERR(handle);
5827
Mingming Cao617ba132006-10-11 01:20:53 -07005828 err = ext4_mark_inode_dirty(handle, inode);
Frank Mayhar03901312009-01-07 00:06:22 -05005829 ext4_handle_sync(handle);
Mingming Cao617ba132006-10-11 01:20:53 -07005830 ext4_journal_stop(handle);
5831 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005832
5833 return err;
5834}
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005835
5836static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
5837{
5838 return !buffer_mapped(bh);
5839}
5840
Nick Pigginc2ec1752009-03-31 15:23:21 -07005841int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005842{
Nick Pigginc2ec1752009-03-31 15:23:21 -07005843 struct page *page = vmf->page;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005844 loff_t size;
5845 unsigned long len;
5846 int ret = -EINVAL;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005847 void *fsdata;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005848 struct file *file = vma->vm_file;
5849 struct inode *inode = file->f_path.dentry->d_inode;
5850 struct address_space *mapping = inode->i_mapping;
5851
5852 /*
5853 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5854 * get i_mutex because we are already holding mmap_sem.
5855 */
5856 down_read(&inode->i_alloc_sem);
5857 size = i_size_read(inode);
5858 if (page->mapping != mapping || size <= page_offset(page)
5859 || !PageUptodate(page)) {
5860 /* page got truncated from under us? */
5861 goto out_unlock;
5862 }
5863 ret = 0;
Darrick J. Wong0e499892011-05-18 13:55:20 -04005864
5865 lock_page(page);
5866 wait_on_page_writeback(page);
5867 if (PageMappedToDisk(page)) {
5868 up_read(&inode->i_alloc_sem);
5869 return VM_FAULT_LOCKED;
5870 }
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005871
5872 if (page->index == size >> PAGE_CACHE_SHIFT)
5873 len = size & ~PAGE_CACHE_MASK;
5874 else
5875 len = PAGE_CACHE_SIZE;
5876
Aneesh Kumar K.Va827eaf2009-09-09 22:36:03 -04005877 /*
5878 * return if we have all the buffers mapped. This avoid
5879 * the need to call write_begin/write_end which does a
5880 * journal_start/journal_stop which can block and take
5881 * long time
5882 */
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005883 if (page_has_buffers(page)) {
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005884 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
Aneesh Kumar K.Va827eaf2009-09-09 22:36:03 -04005885 ext4_bh_unmapped)) {
Darrick J. Wong0e499892011-05-18 13:55:20 -04005886 up_read(&inode->i_alloc_sem);
5887 return VM_FAULT_LOCKED;
Aneesh Kumar K.Va827eaf2009-09-09 22:36:03 -04005888 }
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005889 }
Aneesh Kumar K.Va827eaf2009-09-09 22:36:03 -04005890 unlock_page(page);
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005891 /*
5892 * OK, we need to fill the hole... Do write_begin write_end
5893 * to do block allocation/reservation.We are not holding
5894 * inode.i__mutex here. That allow * parallel write_begin,
5895 * write_end call. lock_page prevent this from happening
5896 * on the same page though
5897 */
5898 ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005899 len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005900 if (ret < 0)
5901 goto out_unlock;
5902 ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005903 len, len, page, fsdata);
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005904 if (ret < 0)
5905 goto out_unlock;
5906 ret = 0;
Darrick J. Wong0e499892011-05-18 13:55:20 -04005907
5908 /*
5909 * write_begin/end might have created a dirty page and someone
5910 * could wander in and start the IO. Make sure that hasn't
5911 * happened.
5912 */
5913 lock_page(page);
5914 wait_on_page_writeback(page);
5915 up_read(&inode->i_alloc_sem);
5916 return VM_FAULT_LOCKED;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005917out_unlock:
Nick Pigginc2ec1752009-03-31 15:23:21 -07005918 if (ret)
5919 ret = VM_FAULT_SIGBUS;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005920 up_read(&inode->i_alloc_sem);
5921 return ret;
5922}