blob: 875db944b22f19889727ed0fcc2b4c60dd4043e4 [file] [log] [blame]
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>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040040#include "ext4_jbd2.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070041#include "xattr.h"
42#include "acl.h"
Mingming Caod2a17632008-07-14 17:52:37 -040043#include "ext4_extents.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070044
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -040045#define MPAGE_DA_EXTENT_TAIL 0x01
46
Jan Kara678aaf42008-07-11 19:27:31 -040047static inline int ext4_begin_ordered_truncate(struct inode *inode,
48 loff_t new_size)
49{
Jan Kara7f5aa212009-02-10 11:15:34 -050050 return jbd2_journal_begin_ordered_truncate(
51 EXT4_SB(inode->i_sb)->s_journal,
52 &EXT4_I(inode)->jinode,
53 new_size);
Jan Kara678aaf42008-07-11 19:27:31 -040054}
55
Alex Tomas64769242008-07-11 19:27:31 -040056static void ext4_invalidatepage(struct page *page, unsigned long offset);
57
Dave Kleikampac27a0e2006-10-11 01:20:50 -070058/*
59 * Test whether an inode is a fast symlink.
60 */
Mingming Cao617ba132006-10-11 01:20:53 -070061static int ext4_inode_is_fast_symlink(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070062{
Mingming Cao617ba132006-10-11 01:20:53 -070063 int ea_blocks = EXT4_I(inode)->i_file_acl ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -070064 (inode->i_sb->s_blocksize >> 9) : 0;
65
66 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
67}
68
69/*
Mingming Cao617ba132006-10-11 01:20:53 -070070 * The ext4 forget function must perform a revoke if we are freeing data
Dave Kleikampac27a0e2006-10-11 01:20:50 -070071 * which has been journaled. Metadata (eg. indirect blocks) must be
72 * revoked in all cases.
73 *
74 * "bh" may be NULL: a metadata block may have been freed from memory
75 * but there may still be a record of it in the journal, and that record
76 * still needs to be revoked.
Frank Mayhar03901312009-01-07 00:06:22 -050077 *
78 * If the handle isn't valid we're not journaling so there's nothing to do.
Dave Kleikampac27a0e2006-10-11 01:20:50 -070079 */
Mingming Cao617ba132006-10-11 01:20:53 -070080int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
81 struct buffer_head *bh, ext4_fsblk_t blocknr)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070082{
83 int err;
84
Frank Mayhar03901312009-01-07 00:06:22 -050085 if (!ext4_handle_valid(handle))
86 return 0;
87
Dave Kleikampac27a0e2006-10-11 01:20:50 -070088 might_sleep();
89
90 BUFFER_TRACE(bh, "enter");
91
92 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
93 "data mode %lx\n",
94 bh, is_metadata, inode->i_mode,
95 test_opt(inode->i_sb, DATA_FLAGS));
96
97 /* Never use the revoke function if we are doing full data
98 * journaling: there is no need to, and a V1 superblock won't
99 * support it. Otherwise, only skip the revoke on un-journaled
100 * data blocks. */
101
Mingming Cao617ba132006-10-11 01:20:53 -0700102 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
103 (!is_metadata && !ext4_should_journal_data(inode))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700104 if (bh) {
Mingming Caodab291a2006-10-11 01:21:01 -0700105 BUFFER_TRACE(bh, "call jbd2_journal_forget");
Mingming Cao617ba132006-10-11 01:20:53 -0700106 return ext4_journal_forget(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700107 }
108 return 0;
109 }
110
111 /*
112 * data!=journal && (is_metadata || should_journal_data(inode))
113 */
Mingming Cao617ba132006-10-11 01:20:53 -0700114 BUFFER_TRACE(bh, "call ext4_journal_revoke");
115 err = ext4_journal_revoke(handle, blocknr, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700116 if (err)
Harvey Harrison46e665e2008-04-17 10:38:59 -0400117 ext4_abort(inode->i_sb, __func__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700118 "error %d when attempting revoke", err);
119 BUFFER_TRACE(bh, "exit");
120 return err;
121}
122
123/*
124 * Work out how many blocks we need to proceed with the next chunk of a
125 * truncate transaction.
126 */
127static unsigned long blocks_for_truncate(struct inode *inode)
128{
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500129 ext4_lblk_t needed;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700130
131 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
132
133 /* Give ourselves just enough room to cope with inodes in which
134 * i_blocks is corrupt: we've seen disk corruptions in the past
135 * which resulted in random data in an inode which looked enough
Mingming Cao617ba132006-10-11 01:20:53 -0700136 * like a regular file for ext4 to try to delete it. Things
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700137 * will go a bit crazy if that happens, but at least we should
138 * try not to panic the whole kernel. */
139 if (needed < 2)
140 needed = 2;
141
142 /* But we need to bound the transaction so we don't overflow the
143 * journal. */
Mingming Cao617ba132006-10-11 01:20:53 -0700144 if (needed > EXT4_MAX_TRANS_DATA)
145 needed = EXT4_MAX_TRANS_DATA;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700146
Mingming Cao617ba132006-10-11 01:20:53 -0700147 return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700148}
149
150/*
151 * Truncate transactions can be complex and absolutely huge. So we need to
152 * be able to restart the transaction at a conventient checkpoint to make
153 * sure we don't overflow the journal.
154 *
155 * start_transaction gets us a new handle for a truncate transaction,
156 * and extend_transaction tries to extend the existing one a bit. If
157 * extend fails, we need to propagate the failure up and restart the
158 * transaction in the top-level truncate loop. --sct
159 */
160static handle_t *start_transaction(struct inode *inode)
161{
162 handle_t *result;
163
Mingming Cao617ba132006-10-11 01:20:53 -0700164 result = ext4_journal_start(inode, blocks_for_truncate(inode));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700165 if (!IS_ERR(result))
166 return result;
167
Mingming Cao617ba132006-10-11 01:20:53 -0700168 ext4_std_error(inode->i_sb, PTR_ERR(result));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700169 return result;
170}
171
172/*
173 * Try to extend this transaction for the purposes of truncation.
174 *
175 * Returns 0 if we managed to create more room. If we can't create more
176 * room, and the transaction must be restarted we return 1.
177 */
178static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
179{
Frank Mayhar03901312009-01-07 00:06:22 -0500180 if (!ext4_handle_valid(handle))
181 return 0;
182 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700183 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700184 if (!ext4_journal_extend(handle, blocks_for_truncate(inode)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700185 return 0;
186 return 1;
187}
188
189/*
190 * Restart the transaction associated with *handle. This does a commit,
191 * so before we call here everything must be consistently dirtied against
192 * this transaction.
193 */
Mingming Cao617ba132006-10-11 01:20:53 -0700194static int ext4_journal_test_restart(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700195{
Frank Mayhar03901312009-01-07 00:06:22 -0500196 BUG_ON(EXT4_JOURNAL(inode) == NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700197 jbd_debug(2, "restarting handle %p\n", handle);
Mingming Cao617ba132006-10-11 01:20:53 -0700198 return ext4_journal_restart(handle, blocks_for_truncate(inode));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700199}
200
201/*
202 * Called at the last iput() if i_nlink is zero.
203 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400204void ext4_delete_inode(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700205{
206 handle_t *handle;
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400207 int err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700208
Jan Kara678aaf42008-07-11 19:27:31 -0400209 if (ext4_should_order_data(inode))
210 ext4_begin_ordered_truncate(inode, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700211 truncate_inode_pages(&inode->i_data, 0);
212
213 if (is_bad_inode(inode))
214 goto no_delete;
215
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400216 handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700217 if (IS_ERR(handle)) {
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400218 ext4_std_error(inode->i_sb, PTR_ERR(handle));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700219 /*
220 * If we're going to skip the normal cleanup, we still need to
221 * make sure that the in-core orphan linked list is properly
222 * cleaned up.
223 */
Mingming Cao617ba132006-10-11 01:20:53 -0700224 ext4_orphan_del(NULL, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700225 goto no_delete;
226 }
227
228 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -0500229 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700230 inode->i_size = 0;
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400231 err = ext4_mark_inode_dirty(handle, inode);
232 if (err) {
233 ext4_warning(inode->i_sb, __func__,
234 "couldn't mark inode dirty (err %d)", err);
235 goto stop_handle;
236 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700237 if (inode->i_blocks)
Mingming Cao617ba132006-10-11 01:20:53 -0700238 ext4_truncate(inode);
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400239
240 /*
241 * ext4_ext_truncate() doesn't reserve any slop when it
242 * restarts journal transactions; therefore there may not be
243 * enough credits left in the handle to remove the inode from
244 * the orphan list and set the dtime field.
245 */
Frank Mayhar03901312009-01-07 00:06:22 -0500246 if (!ext4_handle_has_enough_credits(handle, 3)) {
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400247 err = ext4_journal_extend(handle, 3);
248 if (err > 0)
249 err = ext4_journal_restart(handle, 3);
250 if (err != 0) {
251 ext4_warning(inode->i_sb, __func__,
252 "couldn't extend journal (err %d)", err);
253 stop_handle:
254 ext4_journal_stop(handle);
255 goto no_delete;
256 }
257 }
258
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700259 /*
Mingming Cao617ba132006-10-11 01:20:53 -0700260 * Kill off the orphan record which ext4_truncate created.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700261 * AKPM: I think this can be inside the above `if'.
Mingming Cao617ba132006-10-11 01:20:53 -0700262 * Note that ext4_orphan_del() has to be able to cope with the
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700263 * deletion of a non-existent orphan - this is because we don't
Mingming Cao617ba132006-10-11 01:20:53 -0700264 * know if ext4_truncate() actually created an orphan record.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700265 * (Well, we could do this if we need to, but heck - it works)
266 */
Mingming Cao617ba132006-10-11 01:20:53 -0700267 ext4_orphan_del(handle, inode);
268 EXT4_I(inode)->i_dtime = get_seconds();
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700269
270 /*
271 * One subtle ordering requirement: if anything has gone wrong
272 * (transaction abort, IO errors, whatever), then we can still
273 * do these next steps (the fs will already have been marked as
274 * having errors), but we can't free the inode if the mark_dirty
275 * fails.
276 */
Mingming Cao617ba132006-10-11 01:20:53 -0700277 if (ext4_mark_inode_dirty(handle, inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700278 /* If that failed, just do the required in-core inode clear. */
279 clear_inode(inode);
280 else
Mingming Cao617ba132006-10-11 01:20:53 -0700281 ext4_free_inode(handle, inode);
282 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700283 return;
284no_delete:
285 clear_inode(inode); /* We must guarantee clearing of inode... */
286}
287
288typedef struct {
289 __le32 *p;
290 __le32 key;
291 struct buffer_head *bh;
292} Indirect;
293
294static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
295{
296 p->key = *(p->p = v);
297 p->bh = bh;
298}
299
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700300/**
Mingming Cao617ba132006-10-11 01:20:53 -0700301 * ext4_block_to_path - parse the block number into array of offsets
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700302 * @inode: inode in question (we are only interested in its superblock)
303 * @i_block: block number to be parsed
304 * @offsets: array to store the offsets in
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400305 * @boundary: set this non-zero if the referred-to block is likely to be
306 * followed (on disk) by an indirect block.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700307 *
Mingming Cao617ba132006-10-11 01:20:53 -0700308 * To store the locations of file's data ext4 uses a data structure common
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700309 * for UNIX filesystems - tree of pointers anchored in the inode, with
310 * data blocks at leaves and indirect blocks in intermediate nodes.
311 * This function translates the block number into path in that tree -
312 * return value is the path length and @offsets[n] is the offset of
313 * pointer to (n+1)th node in the nth one. If @block is out of range
314 * (negative or too large) warning is printed and zero returned.
315 *
316 * Note: function doesn't find node addresses, so no IO is needed. All
317 * we need to know is the capacity of indirect blocks (taken from the
318 * inode->i_sb).
319 */
320
321/*
322 * Portability note: the last comparison (check that we fit into triple
323 * indirect block) is spelled differently, because otherwise on an
324 * architecture with 32-bit longs and 8Kb pages we might get into trouble
325 * if our filesystem had 8Kb blocks. We might use long long, but that would
326 * kill us on x86. Oh, well, at least the sign propagation does not matter -
327 * i_block would have to be negative in the very beginning, so we would not
328 * get there at all.
329 */
330
Mingming Cao617ba132006-10-11 01:20:53 -0700331static int ext4_block_to_path(struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500332 ext4_lblk_t i_block,
333 ext4_lblk_t offsets[4], int *boundary)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700334{
Mingming Cao617ba132006-10-11 01:20:53 -0700335 int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
336 int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
337 const long direct_blocks = EXT4_NDIR_BLOCKS,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700338 indirect_blocks = ptrs,
339 double_blocks = (1 << (ptrs_bits * 2));
340 int n = 0;
341 int final = 0;
342
343 if (i_block < 0) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400344 ext4_warning(inode->i_sb, "ext4_block_to_path", "block < 0");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700345 } else if (i_block < direct_blocks) {
346 offsets[n++] = i_block;
347 final = direct_blocks;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400348 } else if ((i_block -= direct_blocks) < indirect_blocks) {
Mingming Cao617ba132006-10-11 01:20:53 -0700349 offsets[n++] = EXT4_IND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700350 offsets[n++] = i_block;
351 final = ptrs;
352 } else if ((i_block -= indirect_blocks) < double_blocks) {
Mingming Cao617ba132006-10-11 01:20:53 -0700353 offsets[n++] = EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700354 offsets[n++] = i_block >> ptrs_bits;
355 offsets[n++] = i_block & (ptrs - 1);
356 final = ptrs;
357 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
Mingming Cao617ba132006-10-11 01:20:53 -0700358 offsets[n++] = EXT4_TIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700359 offsets[n++] = i_block >> (ptrs_bits * 2);
360 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
361 offsets[n++] = i_block & (ptrs - 1);
362 final = ptrs;
363 } else {
Eric Sandeene2b46572008-01-28 23:58:27 -0500364 ext4_warning(inode->i_sb, "ext4_block_to_path",
Theodore Ts'o06a279d2009-01-17 18:41:37 -0500365 "block %lu > max in inode %lu",
Eric Sandeene2b46572008-01-28 23:58:27 -0500366 i_block + direct_blocks +
Theodore Ts'o06a279d2009-01-17 18:41:37 -0500367 indirect_blocks + double_blocks, inode->i_ino);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700368 }
369 if (boundary)
370 *boundary = final - 1 - (i_block & (ptrs - 1));
371 return n;
372}
373
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400374static int __ext4_check_blockref(const char *function, struct inode *inode,
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400375 __le32 *p, unsigned int max)
376{
Thiemo Nagelf73953c2009-04-07 18:46:47 -0400377 __le32 *bref = p;
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400378 unsigned int blk;
379
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400380 while (bref < p+max) {
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400381 blk = le32_to_cpu(*bref++);
382 if (blk &&
383 unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb),
384 blk, 1))) {
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400385 ext4_error(inode->i_sb, function,
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400386 "invalid block reference %u "
387 "in inode #%lu", blk, inode->i_ino);
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400388 return -EIO;
389 }
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400390 }
391 return 0;
392}
393
394
395#define ext4_check_indirect_blockref(inode, bh) \
396 __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data, \
397 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
398
399#define ext4_check_inode_blockref(inode) \
400 __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data, \
401 EXT4_NDIR_BLOCKS)
402
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700403/**
Mingming Cao617ba132006-10-11 01:20:53 -0700404 * ext4_get_branch - read the chain of indirect blocks leading to data
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700405 * @inode: inode in question
406 * @depth: depth of the chain (1 - direct pointer, etc.)
407 * @offsets: offsets of pointers in inode/indirect blocks
408 * @chain: place to store the result
409 * @err: here we store the error value
410 *
411 * Function fills the array of triples <key, p, bh> and returns %NULL
412 * if everything went OK or the pointer to the last filled triple
413 * (incomplete one) otherwise. Upon the return chain[i].key contains
414 * the number of (i+1)-th block in the chain (as it is stored in memory,
415 * i.e. little-endian 32-bit), chain[i].p contains the address of that
416 * number (it points into struct inode for i==0 and into the bh->b_data
417 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
418 * block for i>0 and NULL for i==0. In other words, it holds the block
419 * numbers of the chain, addresses they were taken from (and where we can
420 * verify that chain did not change) and buffer_heads hosting these
421 * numbers.
422 *
423 * Function stops when it stumbles upon zero pointer (absent block)
424 * (pointer to last triple returned, *@err == 0)
425 * or when it gets an IO error reading an indirect block
426 * (ditto, *@err == -EIO)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700427 * or when it reads all @depth-1 indirect blocks successfully and finds
428 * the whole chain, all way to the data (returns %NULL, *err == 0).
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500429 *
430 * Need to be called with
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -0500431 * down_read(&EXT4_I(inode)->i_data_sem)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700432 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500433static Indirect *ext4_get_branch(struct inode *inode, int depth,
434 ext4_lblk_t *offsets,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700435 Indirect chain[4], int *err)
436{
437 struct super_block *sb = inode->i_sb;
438 Indirect *p = chain;
439 struct buffer_head *bh;
440
441 *err = 0;
442 /* i_data is not going away, no lock needed */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400443 add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700444 if (!p->key)
445 goto no_block;
446 while (--depth) {
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400447 bh = sb_getblk(sb, le32_to_cpu(p->key));
448 if (unlikely(!bh))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700449 goto failure;
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400450
451 if (!bh_uptodate_or_lock(bh)) {
452 if (bh_submit_read(bh) < 0) {
453 put_bh(bh);
454 goto failure;
455 }
456 /* validate block references */
457 if (ext4_check_indirect_blockref(inode, bh)) {
458 put_bh(bh);
459 goto failure;
460 }
461 }
462
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400463 add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700464 /* Reader: end */
465 if (!p->key)
466 goto no_block;
467 }
468 return NULL;
469
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700470failure:
471 *err = -EIO;
472no_block:
473 return p;
474}
475
476/**
Mingming Cao617ba132006-10-11 01:20:53 -0700477 * ext4_find_near - find a place for allocation with sufficient locality
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700478 * @inode: owner
479 * @ind: descriptor of indirect block.
480 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000481 * This function returns the preferred place for block allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700482 * It is used when heuristic for sequential allocation fails.
483 * Rules are:
484 * + if there is a block to the left of our position - allocate near it.
485 * + if pointer will live in indirect block - allocate near that block.
486 * + if pointer will live in inode - allocate in the same
487 * cylinder group.
488 *
489 * In the latter case we colour the starting block by the callers PID to
490 * prevent it from clashing with concurrent allocations for a different inode
491 * in the same block group. The PID is used here so that functionally related
492 * files will be close-by on-disk.
493 *
494 * Caller must make sure that @ind is valid and will stay that way.
495 */
Mingming Cao617ba132006-10-11 01:20:53 -0700496static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700497{
Mingming Cao617ba132006-10-11 01:20:53 -0700498 struct ext4_inode_info *ei = EXT4_I(inode);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400499 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700500 __le32 *p;
Mingming Cao617ba132006-10-11 01:20:53 -0700501 ext4_fsblk_t bg_start;
Valerie Clement74d34872008-02-15 13:43:07 -0500502 ext4_fsblk_t last_block;
Mingming Cao617ba132006-10-11 01:20:53 -0700503 ext4_grpblk_t colour;
Theodore Ts'oa4912122009-03-12 12:18:34 -0400504 ext4_group_t block_group;
505 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700506
507 /* Try to find previous block */
508 for (p = ind->p - 1; p >= start; p--) {
509 if (*p)
510 return le32_to_cpu(*p);
511 }
512
513 /* No such thing, so let's try location of indirect block */
514 if (ind->bh)
515 return ind->bh->b_blocknr;
516
517 /*
518 * It is going to be referred to from the inode itself? OK, just put it
519 * into the same cylinder group then.
520 */
Theodore Ts'oa4912122009-03-12 12:18:34 -0400521 block_group = ei->i_block_group;
522 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
523 block_group &= ~(flex_size-1);
524 if (S_ISREG(inode->i_mode))
525 block_group++;
526 }
527 bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
Valerie Clement74d34872008-02-15 13:43:07 -0500528 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
529
Theodore Ts'oa4912122009-03-12 12:18:34 -0400530 /*
531 * If we are doing delayed allocation, we don't need take
532 * colour into account.
533 */
534 if (test_opt(inode->i_sb, DELALLOC))
535 return bg_start;
536
Valerie Clement74d34872008-02-15 13:43:07 -0500537 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
538 colour = (current->pid % 16) *
Mingming Cao617ba132006-10-11 01:20:53 -0700539 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
Valerie Clement74d34872008-02-15 13:43:07 -0500540 else
541 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700542 return bg_start + colour;
543}
544
545/**
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000546 * ext4_find_goal - find a preferred place for allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700547 * @inode: owner
548 * @block: block we want
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700549 * @partial: pointer to the last triple within a chain
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700550 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000551 * Normally this function find the preferred place for block allocation,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800552 * returns it.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700553 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500554static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800555 Indirect *partial)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700556{
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700557 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -0400558 * XXX need to get goal block from mballoc's data structures
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700559 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700560
Mingming Cao617ba132006-10-11 01:20:53 -0700561 return ext4_find_near(inode, partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700562}
563
564/**
Mingming Cao617ba132006-10-11 01:20:53 -0700565 * ext4_blks_to_allocate: Look up the block map and count the number
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700566 * of direct blocks need to be allocated for the given branch.
567 *
568 * @branch: chain of indirect blocks
569 * @k: number of blocks need for indirect blocks
570 * @blks: number of data blocks to be mapped.
571 * @blocks_to_boundary: the offset in the indirect block
572 *
573 * return the total number of blocks to be allocate, including the
574 * direct and indirect blocks.
575 */
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500576static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700577 int blocks_to_boundary)
578{
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500579 unsigned int count = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700580
581 /*
582 * Simple case, [t,d]Indirect block(s) has not allocated yet
583 * then it's clear blocks on that path have not allocated
584 */
585 if (k > 0) {
586 /* right now we don't handle cross boundary allocation */
587 if (blks < blocks_to_boundary + 1)
588 count += blks;
589 else
590 count += blocks_to_boundary + 1;
591 return count;
592 }
593
594 count++;
595 while (count < blks && count <= blocks_to_boundary &&
596 le32_to_cpu(*(branch[0].p + count)) == 0) {
597 count++;
598 }
599 return count;
600}
601
602/**
Mingming Cao617ba132006-10-11 01:20:53 -0700603 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700604 * @indirect_blks: the number of blocks need to allocate for indirect
605 * blocks
606 *
607 * @new_blocks: on return it will store the new block numbers for
608 * the indirect blocks(if needed) and the first direct block,
609 * @blks: on return it will store the total number of allocated
610 * direct blocks
611 */
Mingming Cao617ba132006-10-11 01:20:53 -0700612static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400613 ext4_lblk_t iblock, ext4_fsblk_t goal,
614 int indirect_blks, int blks,
615 ext4_fsblk_t new_blocks[4], int *err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700616{
Theodore Ts'o815a1132009-01-01 23:59:43 -0500617 struct ext4_allocation_request ar;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700618 int target, i;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400619 unsigned long count = 0, blk_allocated = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700620 int index = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700621 ext4_fsblk_t current_block = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700622 int ret = 0;
623
624 /*
625 * Here we try to allocate the requested multiple blocks at once,
626 * on a best-effort basis.
627 * To build a branch, we should allocate blocks for
628 * the indirect blocks(if not allocated yet), and at least
629 * the first direct block of this branch. That's the
630 * minimum number of blocks need to allocate(required)
631 */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400632 /* first we try to allocate the indirect blocks */
633 target = indirect_blks;
634 while (target > 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700635 count = target;
636 /* allocating blocks for indirect blocks and direct blocks */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400637 current_block = ext4_new_meta_blocks(handle, inode,
638 goal, &count, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700639 if (*err)
640 goto failed_out;
641
642 target -= count;
643 /* allocate blocks for indirect blocks */
644 while (index < indirect_blks && count) {
645 new_blocks[index++] = current_block++;
646 count--;
647 }
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400648 if (count > 0) {
649 /*
650 * save the new block number
651 * for the first direct block
652 */
653 new_blocks[index] = current_block;
654 printk(KERN_INFO "%s returned more blocks than "
655 "requested\n", __func__);
656 WARN_ON(1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700657 break;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400658 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700659 }
660
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400661 target = blks - count ;
662 blk_allocated = count;
663 if (!target)
664 goto allocated;
665 /* Now allocate data blocks */
Theodore Ts'o815a1132009-01-01 23:59:43 -0500666 memset(&ar, 0, sizeof(ar));
667 ar.inode = inode;
668 ar.goal = goal;
669 ar.len = target;
670 ar.logical = iblock;
671 if (S_ISREG(inode->i_mode))
672 /* enable in-core preallocation only for regular files */
673 ar.flags = EXT4_MB_HINT_DATA;
674
675 current_block = ext4_mb_new_blocks(handle, &ar, err);
676
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400677 if (*err && (target == blks)) {
678 /*
679 * if the allocation failed and we didn't allocate
680 * any blocks before
681 */
682 goto failed_out;
683 }
684 if (!*err) {
685 if (target == blks) {
686 /*
687 * save the new block number
688 * for the first direct block
689 */
690 new_blocks[index] = current_block;
691 }
Theodore Ts'o815a1132009-01-01 23:59:43 -0500692 blk_allocated += ar.len;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400693 }
694allocated:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700695 /* total number of blocks allocated for direct blocks */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400696 ret = blk_allocated;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700697 *err = 0;
698 return ret;
699failed_out:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400700 for (i = 0; i < index; i++)
Alex Tomasc9de5602008-01-29 00:19:52 -0500701 ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700702 return ret;
703}
704
705/**
Mingming Cao617ba132006-10-11 01:20:53 -0700706 * ext4_alloc_branch - allocate and set up a chain of blocks.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700707 * @inode: owner
708 * @indirect_blks: number of allocated indirect blocks
709 * @blks: number of allocated direct blocks
710 * @offsets: offsets (in the blocks) to store the pointers to next.
711 * @branch: place to store the chain in.
712 *
713 * This function allocates blocks, zeroes out all but the last one,
714 * links them into chain and (if we are synchronous) writes them to disk.
715 * In other words, it prepares a branch that can be spliced onto the
716 * inode. It stores the information about that chain in the branch[], in
Mingming Cao617ba132006-10-11 01:20:53 -0700717 * the same format as ext4_get_branch() would do. We are calling it after
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700718 * we had read the existing part of chain and partial points to the last
719 * triple of that (one with zero ->key). Upon the exit we have the same
Mingming Cao617ba132006-10-11 01:20:53 -0700720 * picture as after the successful ext4_get_block(), except that in one
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700721 * place chain is disconnected - *branch->p is still zero (we did not
722 * set the last link), but branch->key contains the number that should
723 * be placed into *branch->p to fill that gap.
724 *
725 * If allocation fails we free all blocks we've allocated (and forget
726 * their buffer_heads) and return the error value the from failed
Mingming Cao617ba132006-10-11 01:20:53 -0700727 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700728 * as described above and return 0.
729 */
Mingming Cao617ba132006-10-11 01:20:53 -0700730static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400731 ext4_lblk_t iblock, int indirect_blks,
732 int *blks, ext4_fsblk_t goal,
733 ext4_lblk_t *offsets, Indirect *branch)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700734{
735 int blocksize = inode->i_sb->s_blocksize;
736 int i, n = 0;
737 int err = 0;
738 struct buffer_head *bh;
739 int num;
Mingming Cao617ba132006-10-11 01:20:53 -0700740 ext4_fsblk_t new_blocks[4];
741 ext4_fsblk_t current_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700742
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400743 num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700744 *blks, new_blocks, &err);
745 if (err)
746 return err;
747
748 branch[0].key = cpu_to_le32(new_blocks[0]);
749 /*
750 * metadata blocks and data blocks are allocated.
751 */
752 for (n = 1; n <= indirect_blks; n++) {
753 /*
754 * Get buffer_head for parent block, zero it out
755 * and set the pointer to new one, then send
756 * parent to disk.
757 */
758 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
759 branch[n].bh = bh;
760 lock_buffer(bh);
761 BUFFER_TRACE(bh, "call get_create_access");
Mingming Cao617ba132006-10-11 01:20:53 -0700762 err = ext4_journal_get_create_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700763 if (err) {
764 unlock_buffer(bh);
765 brelse(bh);
766 goto failed;
767 }
768
769 memset(bh->b_data, 0, blocksize);
770 branch[n].p = (__le32 *) bh->b_data + offsets[n];
771 branch[n].key = cpu_to_le32(new_blocks[n]);
772 *branch[n].p = branch[n].key;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400773 if (n == indirect_blks) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700774 current_block = new_blocks[n];
775 /*
776 * End of chain, update the last new metablock of
777 * the chain to point to the new allocated
778 * data blocks numbers
779 */
780 for (i=1; i < num; i++)
781 *(branch[n].p + i) = cpu_to_le32(++current_block);
782 }
783 BUFFER_TRACE(bh, "marking uptodate");
784 set_buffer_uptodate(bh);
785 unlock_buffer(bh);
786
Frank Mayhar03901312009-01-07 00:06:22 -0500787 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
788 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700789 if (err)
790 goto failed;
791 }
792 *blks = num;
793 return err;
794failed:
795 /* Allocation failed, free what we already allocated */
796 for (i = 1; i <= n ; i++) {
Mingming Caodab291a2006-10-11 01:21:01 -0700797 BUFFER_TRACE(branch[i].bh, "call jbd2_journal_forget");
Mingming Cao617ba132006-10-11 01:20:53 -0700798 ext4_journal_forget(handle, branch[i].bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700799 }
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400800 for (i = 0; i < indirect_blks; i++)
Alex Tomasc9de5602008-01-29 00:19:52 -0500801 ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700802
Alex Tomasc9de5602008-01-29 00:19:52 -0500803 ext4_free_blocks(handle, inode, new_blocks[i], num, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700804
805 return err;
806}
807
808/**
Mingming Cao617ba132006-10-11 01:20:53 -0700809 * ext4_splice_branch - splice the allocated branch onto inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700810 * @inode: owner
811 * @block: (logical) number of block we are adding
812 * @chain: chain of indirect blocks (with a missing link - see
Mingming Cao617ba132006-10-11 01:20:53 -0700813 * ext4_alloc_branch)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700814 * @where: location of missing link
815 * @num: number of indirect blocks we are adding
816 * @blks: number of direct blocks we are adding
817 *
818 * This function fills the missing link and does all housekeeping needed in
819 * inode (->i_blocks, etc.). In case of success we end up with the full
820 * chain to new block and return 0.
821 */
Mingming Cao617ba132006-10-11 01:20:53 -0700822static int ext4_splice_branch(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500823 ext4_lblk_t block, Indirect *where, int num, int blks)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700824{
825 int i;
826 int err = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700827 ext4_fsblk_t current_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700828
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700829 /*
830 * If we're splicing into a [td]indirect block (as opposed to the
831 * inode) then we need to get write access to the [td]indirect block
832 * before the splice.
833 */
834 if (where->bh) {
835 BUFFER_TRACE(where->bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -0700836 err = ext4_journal_get_write_access(handle, where->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700837 if (err)
838 goto err_out;
839 }
840 /* That's it */
841
842 *where->p = where->key;
843
844 /*
845 * Update the host buffer_head or inode to point to more just allocated
846 * direct blocks blocks
847 */
848 if (num == 0 && blks > 1) {
849 current_block = le32_to_cpu(where->key) + 1;
850 for (i = 1; i < blks; i++)
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400851 *(where->p + i) = cpu_to_le32(current_block++);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700852 }
853
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700854 /* We are done with atomic stuff, now do the rest of housekeeping */
855
Kalpak Shahef7f3832007-07-18 09:15:20 -0400856 inode->i_ctime = ext4_current_time(inode);
Mingming Cao617ba132006-10-11 01:20:53 -0700857 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700858
859 /* had we spliced it onto indirect block? */
860 if (where->bh) {
861 /*
862 * If we spliced it onto an indirect block, we haven't
863 * altered the inode. Note however that if it is being spliced
864 * onto an indirect block at the very end of the file (the
865 * file is growing) then we *will* alter the inode to reflect
866 * the new i_size. But that is not done here - it is done in
Mingming Cao617ba132006-10-11 01:20:53 -0700867 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700868 */
869 jbd_debug(5, "splicing indirect only\n");
Frank Mayhar03901312009-01-07 00:06:22 -0500870 BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
871 err = ext4_handle_dirty_metadata(handle, inode, where->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700872 if (err)
873 goto err_out;
874 } else {
875 /*
876 * OK, we spliced it into the inode itself on a direct block.
877 * Inode was dirtied above.
878 */
879 jbd_debug(5, "splicing direct\n");
880 }
881 return err;
882
883err_out:
884 for (i = 1; i <= num; i++) {
Mingming Caodab291a2006-10-11 01:21:01 -0700885 BUFFER_TRACE(where[i].bh, "call jbd2_journal_forget");
Mingming Cao617ba132006-10-11 01:20:53 -0700886 ext4_journal_forget(handle, where[i].bh);
Alex Tomasc9de5602008-01-29 00:19:52 -0500887 ext4_free_blocks(handle, inode,
888 le32_to_cpu(where[i-1].key), 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700889 }
Alex Tomasc9de5602008-01-29 00:19:52 -0500890 ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700891
892 return err;
893}
894
895/*
Theodore Ts'ob920c752009-05-14 00:54:29 -0400896 * The ext4_ind_get_blocks() function handles non-extents inodes
897 * (i.e., using the traditional indirect/double-indirect i_blocks
898 * scheme) for ext4_get_blocks().
899 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700900 * Allocation strategy is simple: if we have to allocate something, we will
901 * have to go the whole way to leaf. So let's do it before attaching anything
902 * to tree, set linkage between the newborn blocks, write them if sync is
903 * required, recheck the path, free and repeat if check fails, otherwise
904 * set the last missing link (that will protect us from any truncate-generated
905 * removals - all blocks on the path are immune now) and possibly force the
906 * write on the parent block.
907 * That has a nice additional property: no special recovery from the failed
908 * allocations is needed - we simply release blocks and do not touch anything
909 * reachable from inode.
910 *
911 * `handle' can be NULL if create == 0.
912 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700913 * return > 0, # of blocks mapped or allocated.
914 * return = 0, if plain lookup failed.
915 * return < 0, error case.
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500916 *
Theodore Ts'ob920c752009-05-14 00:54:29 -0400917 * The ext4_ind_get_blocks() function should be called with
918 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
919 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
920 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
921 * blocks.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700922 */
Theodore Ts'oe4d996c2009-05-12 00:25:28 -0400923static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500924 ext4_lblk_t iblock, unsigned int maxblocks,
925 struct buffer_head *bh_result,
Theodore Ts'oc2177052009-05-14 00:58:52 -0400926 int flags)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700927{
928 int err = -EIO;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500929 ext4_lblk_t offsets[4];
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700930 Indirect chain[4];
931 Indirect *partial;
Mingming Cao617ba132006-10-11 01:20:53 -0700932 ext4_fsblk_t goal;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700933 int indirect_blks;
934 int blocks_to_boundary = 0;
935 int depth;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700936 int count = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700937 ext4_fsblk_t first_block = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700938
Alex Tomasa86c6182006-10-11 01:21:03 -0700939 J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
Theodore Ts'oc2177052009-05-14 00:58:52 -0400940 J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500941 depth = ext4_block_to_path(inode, iblock, offsets,
942 &blocks_to_boundary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700943
944 if (depth == 0)
945 goto out;
946
Mingming Cao617ba132006-10-11 01:20:53 -0700947 partial = ext4_get_branch(inode, depth, offsets, chain, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700948
949 /* Simplest case - block found, no allocation needed */
950 if (!partial) {
951 first_block = le32_to_cpu(chain[depth - 1].key);
952 clear_buffer_new(bh_result);
953 count++;
954 /*map more blocks*/
955 while (count < maxblocks && count <= blocks_to_boundary) {
Mingming Cao617ba132006-10-11 01:20:53 -0700956 ext4_fsblk_t blk;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700957
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700958 blk = le32_to_cpu(*(chain[depth-1].p + count));
959
960 if (blk == first_block + count)
961 count++;
962 else
963 break;
964 }
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500965 goto got_it;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700966 }
967
968 /* Next simple case - plain lookup or failed read of indirect block */
Theodore Ts'oc2177052009-05-14 00:58:52 -0400969 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700970 goto cleanup;
971
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700972 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -0400973 * Okay, we need to do block allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700974 */
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800975 goal = ext4_find_goal(inode, iblock, partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700976
977 /* the number of blocks need to allocate for [d,t]indirect blocks */
978 indirect_blks = (chain + depth) - partial - 1;
979
980 /*
981 * Next look up the indirect map to count the totoal number of
982 * direct blocks to allocate for this branch.
983 */
Mingming Cao617ba132006-10-11 01:20:53 -0700984 count = ext4_blks_to_allocate(partial, indirect_blks,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700985 maxblocks, blocks_to_boundary);
986 /*
Mingming Cao617ba132006-10-11 01:20:53 -0700987 * Block out ext4_truncate while we alter the tree
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700988 */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400989 err = ext4_alloc_branch(handle, inode, iblock, indirect_blks,
990 &count, goal,
991 offsets + (partial - chain), partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700992
993 /*
Mingming Cao617ba132006-10-11 01:20:53 -0700994 * The ext4_splice_branch call will free and forget any buffers
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700995 * on the new chain if there is a failure, but that risks using
996 * up transaction credits, especially for bitmaps where the
997 * credits cannot be returned. Can we handle this somehow? We
998 * may need to return -EAGAIN upwards in the worst case. --sct
999 */
1000 if (!err)
Mingming Cao617ba132006-10-11 01:20:53 -07001001 err = ext4_splice_branch(handle, inode, iblock,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001002 partial, indirect_blks, count);
Jan Kara03f5d8b2009-06-09 00:17:05 -04001003 else
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001004 goto cleanup;
1005
1006 set_buffer_new(bh_result);
1007got_it:
1008 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
1009 if (count > blocks_to_boundary)
1010 set_buffer_boundary(bh_result);
1011 err = count;
1012 /* Clean up and exit */
1013 partial = chain + depth - 1; /* the whole chain */
1014cleanup:
1015 while (partial > chain) {
1016 BUFFER_TRACE(partial->bh, "call brelse");
1017 brelse(partial->bh);
1018 partial--;
1019 }
1020 BUFFER_TRACE(bh_result, "returned");
1021out:
1022 return err;
1023}
1024
Mingming Cao60e58e02009-01-22 18:13:05 +01001025qsize_t ext4_get_reserved_space(struct inode *inode)
1026{
1027 unsigned long long total;
1028
1029 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1030 total = EXT4_I(inode)->i_reserved_data_blocks +
1031 EXT4_I(inode)->i_reserved_meta_blocks;
1032 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1033
1034 return total;
1035}
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001036/*
1037 * Calculate the number of metadata blocks need to reserve
1038 * to allocate @blocks for non extent file based file
1039 */
1040static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
1041{
1042 int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
1043 int ind_blks, dind_blks, tind_blks;
1044
1045 /* number of new indirect blocks needed */
1046 ind_blks = (blocks + icap - 1) / icap;
1047
1048 dind_blks = (ind_blks + icap - 1) / icap;
1049
1050 tind_blks = 1;
1051
1052 return ind_blks + dind_blks + tind_blks;
1053}
1054
1055/*
1056 * Calculate the number of metadata blocks need to reserve
1057 * to allocate given number of blocks
1058 */
1059static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
1060{
Mingming Caocd213222008-08-19 22:16:59 -04001061 if (!blocks)
1062 return 0;
1063
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001064 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
1065 return ext4_ext_calc_metadata_amount(inode, blocks);
1066
1067 return ext4_indirect_calc_metadata_amount(inode, blocks);
1068}
1069
1070static void ext4_da_update_reserve_space(struct inode *inode, int used)
1071{
1072 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1073 int total, mdb, mdb_free;
1074
1075 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1076 /* recalculate the number of metablocks still need to be reserved */
1077 total = EXT4_I(inode)->i_reserved_data_blocks - used;
1078 mdb = ext4_calc_metadata_amount(inode, total);
1079
1080 /* figure out how many metablocks to release */
1081 BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
1082 mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
1083
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04001084 if (mdb_free) {
1085 /* Account for allocated meta_blocks */
1086 mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001087
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04001088 /* update fs dirty blocks counter */
1089 percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free);
1090 EXT4_I(inode)->i_allocated_meta_blocks = 0;
1091 EXT4_I(inode)->i_reserved_meta_blocks = mdb;
1092 }
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001093
1094 /* update per-inode reservations */
1095 BUG_ON(used > EXT4_I(inode)->i_reserved_data_blocks);
1096 EXT4_I(inode)->i_reserved_data_blocks -= used;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001097 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Cao60e58e02009-01-22 18:13:05 +01001098
1099 /*
1100 * free those over-booking quota for metadata blocks
1101 */
Mingming Cao60e58e02009-01-22 18:13:05 +01001102 if (mdb_free)
1103 vfs_dq_release_reservation_block(inode, mdb_free);
Aneesh Kumar K.Vd6014302009-03-27 22:36:43 -04001104
1105 /*
1106 * If we have done all the pending block allocations and if
1107 * there aren't any writers on the inode, we can discard the
1108 * inode's preallocations.
1109 */
1110 if (!total && (atomic_read(&inode->i_writecount) == 0))
1111 ext4_discard_preallocations(inode);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001112}
1113
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001114static int check_block_validity(struct inode *inode, sector_t logical,
1115 sector_t phys, int len)
1116{
1117 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), phys, len)) {
1118 ext4_error(inode->i_sb, "check_block_validity",
1119 "inode #%lu logical block %llu mapped to %llu "
1120 "(size %d)", inode->i_ino,
1121 (unsigned long long) logical,
1122 (unsigned long long) phys, len);
1123 WARN_ON(1);
1124 return -EIO;
1125 }
1126 return 0;
1127}
1128
Mingming Caof5ab0d12008-02-25 15:29:55 -05001129/*
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04001130 * The ext4_get_blocks() function tries to look up the requested blocks,
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001131 * and returns if the blocks are already mapped.
Mingming Caof5ab0d12008-02-25 15:29:55 -05001132 *
Mingming Caof5ab0d12008-02-25 15:29:55 -05001133 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1134 * and store the allocated blocks in the result buffer head and mark it
1135 * mapped.
1136 *
1137 * If file type is extents based, it will call ext4_ext_get_blocks(),
Theodore Ts'oe4d996c2009-05-12 00:25:28 -04001138 * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
Mingming Caof5ab0d12008-02-25 15:29:55 -05001139 * based files
1140 *
1141 * On success, it returns the number of blocks being mapped or allocate.
1142 * if create==0 and the blocks are pre-allocated and uninitialized block,
1143 * the result buffer head is unmapped. If the create ==1, it will make sure
1144 * the buffer head is mapped.
1145 *
1146 * It returns 0 if plain look up failed (blocks have not been allocated), in
1147 * that casem, buffer head is unmapped
1148 *
1149 * It returns the error in case of allocation failure.
1150 */
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04001151int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
1152 unsigned int max_blocks, struct buffer_head *bh,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001153 int flags)
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001154{
1155 int retval;
Mingming Caof5ab0d12008-02-25 15:29:55 -05001156
1157 clear_buffer_mapped(bh);
Aneesh Kumar K.V2a8964d2009-05-14 17:05:39 -04001158 clear_buffer_unwritten(bh);
Mingming Caof5ab0d12008-02-25 15:29:55 -05001159
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001160 /*
Theodore Ts'ob920c752009-05-14 00:54:29 -04001161 * Try to see if we can get the block without requesting a new
1162 * file system block.
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001163 */
1164 down_read((&EXT4_I(inode)->i_data_sem));
1165 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
1166 retval = ext4_ext_get_blocks(handle, inode, block, max_blocks,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001167 bh, 0);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001168 } else {
Theodore Ts'oe4d996c2009-05-12 00:25:28 -04001169 retval = ext4_ind_get_blocks(handle, inode, block, max_blocks,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001170 bh, 0);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001171 }
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001172 up_read((&EXT4_I(inode)->i_data_sem));
Mingming Caof5ab0d12008-02-25 15:29:55 -05001173
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001174 if (retval > 0 && buffer_mapped(bh)) {
1175 int ret = check_block_validity(inode, block,
1176 bh->b_blocknr, retval);
1177 if (ret != 0)
1178 return ret;
1179 }
1180
Mingming Caof5ab0d12008-02-25 15:29:55 -05001181 /* If it is only a block(s) look up */
Theodore Ts'oc2177052009-05-14 00:58:52 -04001182 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001183 return retval;
1184
1185 /*
Mingming Caof5ab0d12008-02-25 15:29:55 -05001186 * Returns if the blocks have already allocated
1187 *
1188 * Note that if blocks have been preallocated
1189 * ext4_ext_get_block() returns th create = 0
1190 * with buffer head unmapped.
1191 */
1192 if (retval > 0 && buffer_mapped(bh))
1193 return retval;
1194
1195 /*
Aneesh Kumar K.V2a8964d2009-05-14 17:05:39 -04001196 * When we call get_blocks without the create flag, the
1197 * BH_Unwritten flag could have gotten set if the blocks
1198 * requested were part of a uninitialized extent. We need to
1199 * clear this flag now that we are committed to convert all or
1200 * part of the uninitialized extent to be an initialized
1201 * extent. This is because we need to avoid the combination
1202 * of BH_Unwritten and BH_Mapped flags being simultaneously
1203 * set on the buffer_head.
1204 */
1205 clear_buffer_unwritten(bh);
1206
1207 /*
Mingming Caof5ab0d12008-02-25 15:29:55 -05001208 * New blocks allocate and/or writing to uninitialized extent
1209 * will possibly result in updating i_data, so we take
1210 * the write lock of i_data_sem, and call get_blocks()
1211 * with create == 1 flag.
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001212 */
1213 down_write((&EXT4_I(inode)->i_data_sem));
Mingming Caod2a17632008-07-14 17:52:37 -04001214
1215 /*
1216 * if the caller is from delayed allocation writeout path
1217 * we have already reserved fs blocks for allocation
1218 * let the underlying get_block() function know to
1219 * avoid double accounting
1220 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04001221 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
Mingming Caod2a17632008-07-14 17:52:37 -04001222 EXT4_I(inode)->i_delalloc_reserved_flag = 1;
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001223 /*
1224 * We need to check for EXT4 here because migrate
1225 * could have changed the inode type in between
1226 */
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001227 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
1228 retval = ext4_ext_get_blocks(handle, inode, block, max_blocks,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001229 bh, flags);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001230 } else {
Theodore Ts'oe4d996c2009-05-12 00:25:28 -04001231 retval = ext4_ind_get_blocks(handle, inode, block,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001232 max_blocks, bh, flags);
Aneesh Kumar K.V267e4db2008-04-29 08:11:12 -04001233
1234 if (retval > 0 && buffer_new(bh)) {
1235 /*
1236 * We allocated new blocks which will result in
1237 * i_data's format changing. Force the migrate
1238 * to fail by clearing migrate flags
1239 */
1240 EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags &
1241 ~EXT4_EXT_MIGRATE;
1242 }
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001243 }
Mingming Caod2a17632008-07-14 17:52:37 -04001244
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04001245 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
Mingming Caod2a17632008-07-14 17:52:37 -04001246 EXT4_I(inode)->i_delalloc_reserved_flag = 0;
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04001247
1248 /*
1249 * Update reserved blocks/metadata blocks after successful
1250 * block allocation which had been deferred till now.
1251 */
1252 if ((retval > 0) && (flags & EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE))
1253 ext4_da_update_reserve_space(inode, retval);
Mingming Caod2a17632008-07-14 17:52:37 -04001254
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001255 up_write((&EXT4_I(inode)->i_data_sem));
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001256 if (retval > 0 && buffer_mapped(bh)) {
1257 int ret = check_block_validity(inode, block,
1258 bh->b_blocknr, retval);
1259 if (ret != 0)
1260 return ret;
1261 }
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001262 return retval;
1263}
1264
Mingming Caof3bd1f32008-08-19 22:16:03 -04001265/* Maximum number of blocks we map for direct IO at once. */
1266#define DIO_MAX_BLOCKS 4096
1267
Eric Sandeen6873fa02008-10-07 00:46:36 -04001268int ext4_get_block(struct inode *inode, sector_t iblock,
1269 struct buffer_head *bh_result, int create)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001270{
Dmitriy Monakhov3e4fdaf2007-02-10 01:46:35 -08001271 handle_t *handle = ext4_journal_current_handle();
Jan Kara7fb54092008-02-10 01:08:38 -05001272 int ret = 0, started = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001273 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
Mingming Caof3bd1f32008-08-19 22:16:03 -04001274 int dio_credits;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001275
Jan Kara7fb54092008-02-10 01:08:38 -05001276 if (create && !handle) {
1277 /* Direct IO write... */
1278 if (max_blocks > DIO_MAX_BLOCKS)
1279 max_blocks = DIO_MAX_BLOCKS;
Mingming Caof3bd1f32008-08-19 22:16:03 -04001280 dio_credits = ext4_chunk_trans_blocks(inode, max_blocks);
1281 handle = ext4_journal_start(inode, dio_credits);
Jan Kara7fb54092008-02-10 01:08:38 -05001282 if (IS_ERR(handle)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001283 ret = PTR_ERR(handle);
Jan Kara7fb54092008-02-10 01:08:38 -05001284 goto out;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001285 }
Jan Kara7fb54092008-02-10 01:08:38 -05001286 started = 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001287 }
1288
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04001289 ret = ext4_get_blocks(handle, inode, iblock, max_blocks, bh_result,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001290 create ? EXT4_GET_BLOCKS_CREATE : 0);
Jan Kara7fb54092008-02-10 01:08:38 -05001291 if (ret > 0) {
1292 bh_result->b_size = (ret << inode->i_blkbits);
1293 ret = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001294 }
Jan Kara7fb54092008-02-10 01:08:38 -05001295 if (started)
1296 ext4_journal_stop(handle);
1297out:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001298 return ret;
1299}
1300
1301/*
1302 * `handle' can be NULL if create is zero
1303 */
Mingming Cao617ba132006-10-11 01:20:53 -07001304struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001305 ext4_lblk_t block, int create, int *errp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001306{
1307 struct buffer_head dummy;
1308 int fatal = 0, err;
Jan Kara03f5d8b2009-06-09 00:17:05 -04001309 int flags = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001310
1311 J_ASSERT(handle != NULL || create == 0);
1312
1313 dummy.b_state = 0;
1314 dummy.b_blocknr = -1000;
1315 buffer_trace_init(&dummy.b_history);
Theodore Ts'oc2177052009-05-14 00:58:52 -04001316 if (create)
1317 flags |= EXT4_GET_BLOCKS_CREATE;
1318 err = ext4_get_blocks(handle, inode, block, 1, &dummy, flags);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001319 /*
Theodore Ts'oc2177052009-05-14 00:58:52 -04001320 * ext4_get_blocks() returns number of blocks mapped. 0 in
1321 * case of a HOLE.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001322 */
1323 if (err > 0) {
1324 if (err > 1)
1325 WARN_ON(1);
1326 err = 0;
1327 }
1328 *errp = err;
1329 if (!err && buffer_mapped(&dummy)) {
1330 struct buffer_head *bh;
1331 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
1332 if (!bh) {
1333 *errp = -EIO;
1334 goto err;
1335 }
1336 if (buffer_new(&dummy)) {
1337 J_ASSERT(create != 0);
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001338 J_ASSERT(handle != NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001339
1340 /*
1341 * Now that we do not always journal data, we should
1342 * keep in mind whether this should always journal the
1343 * new buffer as metadata. For now, regular file
Mingming Cao617ba132006-10-11 01:20:53 -07001344 * writes use ext4_get_block instead, so it's not a
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001345 * problem.
1346 */
1347 lock_buffer(bh);
1348 BUFFER_TRACE(bh, "call get_create_access");
Mingming Cao617ba132006-10-11 01:20:53 -07001349 fatal = ext4_journal_get_create_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001350 if (!fatal && !buffer_uptodate(bh)) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001351 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001352 set_buffer_uptodate(bh);
1353 }
1354 unlock_buffer(bh);
Frank Mayhar03901312009-01-07 00:06:22 -05001355 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1356 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001357 if (!fatal)
1358 fatal = err;
1359 } else {
1360 BUFFER_TRACE(bh, "not a new buffer");
1361 }
1362 if (fatal) {
1363 *errp = fatal;
1364 brelse(bh);
1365 bh = NULL;
1366 }
1367 return bh;
1368 }
1369err:
1370 return NULL;
1371}
1372
Mingming Cao617ba132006-10-11 01:20:53 -07001373struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001374 ext4_lblk_t block, int create, int *err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001375{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001376 struct buffer_head *bh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001377
Mingming Cao617ba132006-10-11 01:20:53 -07001378 bh = ext4_getblk(handle, inode, block, create, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001379 if (!bh)
1380 return bh;
1381 if (buffer_uptodate(bh))
1382 return bh;
1383 ll_rw_block(READ_META, 1, &bh);
1384 wait_on_buffer(bh);
1385 if (buffer_uptodate(bh))
1386 return bh;
1387 put_bh(bh);
1388 *err = -EIO;
1389 return NULL;
1390}
1391
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001392static int walk_page_buffers(handle_t *handle,
1393 struct buffer_head *head,
1394 unsigned from,
1395 unsigned to,
1396 int *partial,
1397 int (*fn)(handle_t *handle,
1398 struct buffer_head *bh))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001399{
1400 struct buffer_head *bh;
1401 unsigned block_start, block_end;
1402 unsigned blocksize = head->b_size;
1403 int err, ret = 0;
1404 struct buffer_head *next;
1405
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001406 for (bh = head, block_start = 0;
1407 ret == 0 && (bh != head || !block_start);
1408 block_start = block_end, bh = next)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001409 {
1410 next = bh->b_this_page;
1411 block_end = block_start + blocksize;
1412 if (block_end <= from || block_start >= to) {
1413 if (partial && !buffer_uptodate(bh))
1414 *partial = 1;
1415 continue;
1416 }
1417 err = (*fn)(handle, bh);
1418 if (!ret)
1419 ret = err;
1420 }
1421 return ret;
1422}
1423
1424/*
1425 * To preserve ordering, it is essential that the hole instantiation and
1426 * the data write be encapsulated in a single transaction. We cannot
Mingming Cao617ba132006-10-11 01:20:53 -07001427 * close off a transaction and start a new one between the ext4_get_block()
Mingming Caodab291a2006-10-11 01:21:01 -07001428 * and the commit_write(). So doing the jbd2_journal_start at the start of
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001429 * prepare_write() is the right place.
1430 *
Mingming Cao617ba132006-10-11 01:20:53 -07001431 * Also, this function can nest inside ext4_writepage() ->
1432 * block_write_full_page(). In that case, we *know* that ext4_writepage()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001433 * has generated enough buffer credits to do the whole page. So we won't
1434 * block on the journal in that case, which is good, because the caller may
1435 * be PF_MEMALLOC.
1436 *
Mingming Cao617ba132006-10-11 01:20:53 -07001437 * By accident, ext4 can be reentered when a transaction is open via
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001438 * quota file writes. If we were to commit the transaction while thus
1439 * reentered, there can be a deadlock - we would be holding a quota
1440 * lock, and the commit would never complete if another thread had a
1441 * transaction open and was blocking on the quota lock - a ranking
1442 * violation.
1443 *
Mingming Caodab291a2006-10-11 01:21:01 -07001444 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001445 * will _not_ run commit under these circumstances because handle->h_ref
1446 * is elevated. We'll still have enough credits for the tiny quotafile
1447 * write.
1448 */
1449static int do_journal_get_write_access(handle_t *handle,
1450 struct buffer_head *bh)
1451{
1452 if (!buffer_mapped(bh) || buffer_freed(bh))
1453 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -07001454 return ext4_journal_get_write_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001455}
1456
Nick Pigginbfc1af62007-10-16 01:25:05 -07001457static int ext4_write_begin(struct file *file, struct address_space *mapping,
1458 loff_t pos, unsigned len, unsigned flags,
1459 struct page **pagep, void **fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001460{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001461 struct inode *inode = mapping->host;
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001462 int ret, needed_blocks;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001463 handle_t *handle;
1464 int retries = 0;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001465 struct page *page;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001466 pgoff_t index;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001467 unsigned from, to;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001468
Theodore Ts'oba80b102009-01-03 20:03:21 -05001469 trace_mark(ext4_write_begin,
1470 "dev %s ino %lu pos %llu len %u flags %u",
1471 inode->i_sb->s_id, inode->i_ino,
1472 (unsigned long long) pos, len, flags);
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001473 /*
1474 * Reserve one block more for addition to orphan list in case
1475 * we allocate blocks but write fails for some reason
1476 */
1477 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001478 index = pos >> PAGE_CACHE_SHIFT;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001479 from = pos & (PAGE_CACHE_SIZE - 1);
1480 to = from + len;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001481
1482retry:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001483 handle = ext4_journal_start(inode, needed_blocks);
1484 if (IS_ERR(handle)) {
1485 ret = PTR_ERR(handle);
1486 goto out;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001487 }
1488
Jan Karaebd36102009-02-22 21:09:59 -05001489 /* We cannot recurse into the filesystem as the transaction is already
1490 * started */
1491 flags |= AOP_FLAG_NOFS;
1492
Nick Piggin54566b22009-01-04 12:00:53 -08001493 page = grab_cache_page_write_begin(mapping, index, flags);
Jan Karacf108bc2008-07-11 19:27:31 -04001494 if (!page) {
1495 ext4_journal_stop(handle);
1496 ret = -ENOMEM;
1497 goto out;
1498 }
1499 *pagep = page;
1500
Nick Pigginbfc1af62007-10-16 01:25:05 -07001501 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
Jan Karaebd36102009-02-22 21:09:59 -05001502 ext4_get_block);
Nick Pigginbfc1af62007-10-16 01:25:05 -07001503
1504 if (!ret && ext4_should_journal_data(inode)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001505 ret = walk_page_buffers(handle, page_buffers(page),
1506 from, to, NULL, do_journal_get_write_access);
1507 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001508
1509 if (ret) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001510 unlock_page(page);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001511 page_cache_release(page);
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001512 /*
1513 * block_write_begin may have instantiated a few blocks
1514 * outside i_size. Trim these off again. Don't need
1515 * i_size_read because we hold i_mutex.
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001516 *
1517 * Add inode to orphan list in case we crash before
1518 * truncate finishes
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001519 */
1520 if (pos + len > inode->i_size)
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001521 ext4_orphan_add(handle, inode);
1522
1523 ext4_journal_stop(handle);
1524 if (pos + len > inode->i_size) {
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001525 vmtruncate(inode, inode->i_size);
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001526 /*
1527 * If vmtruncate failed early the inode might
1528 * still be on the orphan list; we need to
1529 * make sure the inode is removed from the
1530 * orphan list in that case.
1531 */
1532 if (inode->i_nlink)
1533 ext4_orphan_del(NULL, inode);
1534 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001535 }
1536
Mingming Cao617ba132006-10-11 01:20:53 -07001537 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001538 goto retry;
Andrew Morton7479d2b2007-04-01 23:49:44 -07001539out:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001540 return ret;
1541}
1542
Nick Pigginbfc1af62007-10-16 01:25:05 -07001543/* For write_end() in data=journal mode */
1544static int write_end_fn(handle_t *handle, struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001545{
1546 if (!buffer_mapped(bh) || buffer_freed(bh))
1547 return 0;
1548 set_buffer_uptodate(bh);
Frank Mayhar03901312009-01-07 00:06:22 -05001549 return ext4_handle_dirty_metadata(handle, NULL, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001550}
1551
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001552static int ext4_generic_write_end(struct file *file,
1553 struct address_space *mapping,
1554 loff_t pos, unsigned len, unsigned copied,
1555 struct page *page, void *fsdata)
1556{
1557 int i_size_changed = 0;
1558 struct inode *inode = mapping->host;
1559 handle_t *handle = ext4_journal_current_handle();
1560
1561 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1562
1563 /*
1564 * No need to use i_size_read() here, the i_size
1565 * cannot change under us because we hold i_mutex.
1566 *
1567 * But it's important to update i_size while still holding page lock:
1568 * page writeout could otherwise come in and zero beyond i_size.
1569 */
1570 if (pos + copied > inode->i_size) {
1571 i_size_write(inode, pos + copied);
1572 i_size_changed = 1;
1573 }
1574
1575 if (pos + copied > EXT4_I(inode)->i_disksize) {
1576 /* We need to mark inode dirty even if
1577 * new_i_size is less that inode->i_size
1578 * bu greater than i_disksize.(hint delalloc)
1579 */
1580 ext4_update_i_disksize(inode, (pos + copied));
1581 i_size_changed = 1;
1582 }
1583 unlock_page(page);
1584 page_cache_release(page);
1585
1586 /*
1587 * Don't mark the inode dirty under page lock. First, it unnecessarily
1588 * makes the holding time of page lock longer. Second, it forces lock
1589 * ordering of page lock and transaction start for journaling
1590 * filesystems.
1591 */
1592 if (i_size_changed)
1593 ext4_mark_inode_dirty(handle, inode);
1594
1595 return copied;
1596}
1597
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001598/*
1599 * We need to pick up the new inode size which generic_commit_write gave us
1600 * `file' can be NULL - eg, when called from page_symlink().
1601 *
Mingming Cao617ba132006-10-11 01:20:53 -07001602 * ext4 never places buffers on inode->i_mapping->private_list. metadata
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001603 * buffers are managed internally.
1604 */
Nick Pigginbfc1af62007-10-16 01:25:05 -07001605static int ext4_ordered_write_end(struct file *file,
1606 struct address_space *mapping,
1607 loff_t pos, unsigned len, unsigned copied,
1608 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001609{
Mingming Cao617ba132006-10-11 01:20:53 -07001610 handle_t *handle = ext4_journal_current_handle();
Jan Karacf108bc2008-07-11 19:27:31 -04001611 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001612 int ret = 0, ret2;
1613
Theodore Ts'oba80b102009-01-03 20:03:21 -05001614 trace_mark(ext4_ordered_write_end,
1615 "dev %s ino %lu pos %llu len %u copied %u",
1616 inode->i_sb->s_id, inode->i_ino,
1617 (unsigned long long) pos, len, copied);
Jan Kara678aaf42008-07-11 19:27:31 -04001618 ret = ext4_jbd2_file_inode(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001619
1620 if (ret == 0) {
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001621 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001622 page, fsdata);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001623 copied = ret2;
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001624 if (pos + len > inode->i_size)
1625 /* if we have allocated more blocks and copied
1626 * less. We will have blocks allocated outside
1627 * inode->i_size. So truncate them
1628 */
1629 ext4_orphan_add(handle, inode);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001630 if (ret2 < 0)
1631 ret = ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001632 }
Mingming Cao617ba132006-10-11 01:20:53 -07001633 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001634 if (!ret)
1635 ret = ret2;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001636
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001637 if (pos + len > inode->i_size) {
1638 vmtruncate(inode, inode->i_size);
1639 /*
1640 * If vmtruncate failed early the inode might still be
1641 * on the orphan list; we need to make sure the inode
1642 * is removed from the orphan list in that case.
1643 */
1644 if (inode->i_nlink)
1645 ext4_orphan_del(NULL, inode);
1646 }
1647
1648
Nick Pigginbfc1af62007-10-16 01:25:05 -07001649 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001650}
1651
Nick Pigginbfc1af62007-10-16 01:25:05 -07001652static int ext4_writeback_write_end(struct file *file,
1653 struct address_space *mapping,
1654 loff_t pos, unsigned len, unsigned copied,
1655 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001656{
Mingming Cao617ba132006-10-11 01:20:53 -07001657 handle_t *handle = ext4_journal_current_handle();
Jan Karacf108bc2008-07-11 19:27:31 -04001658 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001659 int ret = 0, ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001660
Theodore Ts'oba80b102009-01-03 20:03:21 -05001661 trace_mark(ext4_writeback_write_end,
1662 "dev %s ino %lu pos %llu len %u copied %u",
1663 inode->i_sb->s_id, inode->i_ino,
1664 (unsigned long long) pos, len, copied);
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001665 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001666 page, fsdata);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001667 copied = ret2;
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001668 if (pos + len > inode->i_size)
1669 /* if we have allocated more blocks and copied
1670 * less. We will have blocks allocated outside
1671 * inode->i_size. So truncate them
1672 */
1673 ext4_orphan_add(handle, inode);
1674
Roel Kluinf8a87d82008-04-29 22:01:18 -04001675 if (ret2 < 0)
1676 ret = ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001677
Mingming Cao617ba132006-10-11 01:20:53 -07001678 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001679 if (!ret)
1680 ret = ret2;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001681
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001682 if (pos + len > inode->i_size) {
1683 vmtruncate(inode, inode->i_size);
1684 /*
1685 * If vmtruncate failed early the inode might still be
1686 * on the orphan list; we need to make sure the inode
1687 * is removed from the orphan list in that case.
1688 */
1689 if (inode->i_nlink)
1690 ext4_orphan_del(NULL, inode);
1691 }
1692
Nick Pigginbfc1af62007-10-16 01:25:05 -07001693 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001694}
1695
Nick Pigginbfc1af62007-10-16 01:25:05 -07001696static int ext4_journalled_write_end(struct file *file,
1697 struct address_space *mapping,
1698 loff_t pos, unsigned len, unsigned copied,
1699 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001700{
Mingming Cao617ba132006-10-11 01:20:53 -07001701 handle_t *handle = ext4_journal_current_handle();
Nick Pigginbfc1af62007-10-16 01:25:05 -07001702 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001703 int ret = 0, ret2;
1704 int partial = 0;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001705 unsigned from, to;
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001706 loff_t new_i_size;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001707
Theodore Ts'oba80b102009-01-03 20:03:21 -05001708 trace_mark(ext4_journalled_write_end,
1709 "dev %s ino %lu pos %llu len %u copied %u",
1710 inode->i_sb->s_id, inode->i_ino,
1711 (unsigned long long) pos, len, copied);
Nick Pigginbfc1af62007-10-16 01:25:05 -07001712 from = pos & (PAGE_CACHE_SIZE - 1);
1713 to = from + len;
1714
1715 if (copied < len) {
1716 if (!PageUptodate(page))
1717 copied = 0;
1718 page_zero_new_buffers(page, from+copied, to);
1719 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001720
1721 ret = walk_page_buffers(handle, page_buffers(page), from,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001722 to, &partial, write_end_fn);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001723 if (!partial)
1724 SetPageUptodate(page);
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001725 new_i_size = pos + copied;
1726 if (new_i_size > inode->i_size)
Nick Pigginbfc1af62007-10-16 01:25:05 -07001727 i_size_write(inode, pos+copied);
Mingming Cao617ba132006-10-11 01:20:53 -07001728 EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001729 if (new_i_size > EXT4_I(inode)->i_disksize) {
1730 ext4_update_i_disksize(inode, new_i_size);
Mingming Cao617ba132006-10-11 01:20:53 -07001731 ret2 = ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001732 if (!ret)
1733 ret = ret2;
1734 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001735
Jan Karacf108bc2008-07-11 19:27:31 -04001736 unlock_page(page);
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001737 page_cache_release(page);
1738 if (pos + len > inode->i_size)
1739 /* if we have allocated more blocks and copied
1740 * less. We will have blocks allocated outside
1741 * inode->i_size. So truncate them
1742 */
1743 ext4_orphan_add(handle, inode);
1744
Mingming Cao617ba132006-10-11 01:20:53 -07001745 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001746 if (!ret)
1747 ret = ret2;
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001748 if (pos + len > inode->i_size) {
1749 vmtruncate(inode, inode->i_size);
1750 /*
1751 * If vmtruncate failed early the inode might still be
1752 * on the orphan list; we need to make sure the inode
1753 * is removed from the orphan list in that case.
1754 */
1755 if (inode->i_nlink)
1756 ext4_orphan_del(NULL, inode);
1757 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001758
1759 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001760}
Mingming Caod2a17632008-07-14 17:52:37 -04001761
1762static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
1763{
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001764 int retries = 0;
Mingming Cao60e58e02009-01-22 18:13:05 +01001765 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1766 unsigned long md_needed, mdblocks, total = 0;
Mingming Caod2a17632008-07-14 17:52:37 -04001767
1768 /*
1769 * recalculate the amount of metadata blocks to reserve
1770 * in order to allocate nrblocks
1771 * worse case is one extent per block
1772 */
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001773repeat:
Mingming Caod2a17632008-07-14 17:52:37 -04001774 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1775 total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks;
1776 mdblocks = ext4_calc_metadata_amount(inode, total);
1777 BUG_ON(mdblocks < EXT4_I(inode)->i_reserved_meta_blocks);
1778
1779 md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
1780 total = md_needed + nrblocks;
1781
Mingming Cao60e58e02009-01-22 18:13:05 +01001782 /*
1783 * Make quota reservation here to prevent quota overflow
1784 * later. Real quota accounting is done at pages writeout
1785 * time.
1786 */
1787 if (vfs_dq_reserve_block(inode, total)) {
1788 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1789 return -EDQUOT;
1790 }
1791
Aneesh Kumar K.Va30d542a2008-10-09 10:56:23 -04001792 if (ext4_claim_free_blocks(sbi, total)) {
Mingming Caod2a17632008-07-14 17:52:37 -04001793 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001794 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1795 yield();
1796 goto repeat;
1797 }
Mingming Cao60e58e02009-01-22 18:13:05 +01001798 vfs_dq_release_reservation_block(inode, total);
Mingming Caod2a17632008-07-14 17:52:37 -04001799 return -ENOSPC;
1800 }
Mingming Caod2a17632008-07-14 17:52:37 -04001801 EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
1802 EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
1803
1804 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1805 return 0; /* success */
1806}
1807
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001808static void ext4_da_release_space(struct inode *inode, int to_free)
Mingming Caod2a17632008-07-14 17:52:37 -04001809{
1810 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1811 int total, mdb, mdb_free, release;
1812
Mingming Caocd213222008-08-19 22:16:59 -04001813 if (!to_free)
1814 return; /* Nothing to release, exit */
1815
Mingming Caod2a17632008-07-14 17:52:37 -04001816 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Caocd213222008-08-19 22:16:59 -04001817
1818 if (!EXT4_I(inode)->i_reserved_data_blocks) {
1819 /*
1820 * if there is no reserved blocks, but we try to free some
1821 * then the counter is messed up somewhere.
1822 * but since this function is called from invalidate
1823 * page, it's harmless to return without any action
1824 */
1825 printk(KERN_INFO "ext4 delalloc try to release %d reserved "
1826 "blocks for inode %lu, but there is no reserved "
1827 "data blocks\n", to_free, inode->i_ino);
1828 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1829 return;
1830 }
1831
Mingming Caod2a17632008-07-14 17:52:37 -04001832 /* recalculate the number of metablocks still need to be reserved */
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001833 total = EXT4_I(inode)->i_reserved_data_blocks - to_free;
Mingming Caod2a17632008-07-14 17:52:37 -04001834 mdb = ext4_calc_metadata_amount(inode, total);
1835
1836 /* figure out how many metablocks to release */
1837 BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
1838 mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
1839
Mingming Caod2a17632008-07-14 17:52:37 -04001840 release = to_free + mdb_free;
1841
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04001842 /* update fs dirty blocks counter for truncate case */
1843 percpu_counter_sub(&sbi->s_dirtyblocks_counter, release);
Mingming Caod2a17632008-07-14 17:52:37 -04001844
1845 /* update per-inode reservations */
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001846 BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks);
1847 EXT4_I(inode)->i_reserved_data_blocks -= to_free;
Mingming Caod2a17632008-07-14 17:52:37 -04001848
1849 BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
1850 EXT4_I(inode)->i_reserved_meta_blocks = mdb;
Mingming Caod2a17632008-07-14 17:52:37 -04001851 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Cao60e58e02009-01-22 18:13:05 +01001852
1853 vfs_dq_release_reservation_block(inode, release);
Mingming Caod2a17632008-07-14 17:52:37 -04001854}
1855
1856static void ext4_da_page_release_reservation(struct page *page,
1857 unsigned long offset)
1858{
1859 int to_release = 0;
1860 struct buffer_head *head, *bh;
1861 unsigned int curr_off = 0;
1862
1863 head = page_buffers(page);
1864 bh = head;
1865 do {
1866 unsigned int next_off = curr_off + bh->b_size;
1867
1868 if ((offset <= curr_off) && (buffer_delay(bh))) {
1869 to_release++;
1870 clear_buffer_delay(bh);
1871 }
1872 curr_off = next_off;
1873 } while ((bh = bh->b_this_page) != head);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001874 ext4_da_release_space(page->mapping->host, to_release);
Mingming Caod2a17632008-07-14 17:52:37 -04001875}
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001876
1877/*
Alex Tomas64769242008-07-11 19:27:31 -04001878 * Delayed allocation stuff
1879 */
1880
1881struct mpage_da_data {
1882 struct inode *inode;
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05001883 sector_t b_blocknr; /* start block number of extent */
1884 size_t b_size; /* size of extent */
1885 unsigned long b_state; /* state of the extent */
Alex Tomas64769242008-07-11 19:27:31 -04001886 unsigned long first_page, next_page; /* extent of pages */
Alex Tomas64769242008-07-11 19:27:31 -04001887 struct writeback_control *wbc;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001888 int io_done;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05001889 int pages_written;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04001890 int retval;
Alex Tomas64769242008-07-11 19:27:31 -04001891};
1892
1893/*
1894 * mpage_da_submit_io - walks through extent of pages and try to write
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001895 * them with writepage() call back
Alex Tomas64769242008-07-11 19:27:31 -04001896 *
1897 * @mpd->inode: inode
1898 * @mpd->first_page: first page of the extent
1899 * @mpd->next_page: page after the last page of the extent
Alex Tomas64769242008-07-11 19:27:31 -04001900 *
1901 * By the time mpage_da_submit_io() is called we expect all blocks
1902 * to be allocated. this may be wrong if allocation failed.
1903 *
1904 * As pages are already locked by write_cache_pages(), we can't use it
1905 */
1906static int mpage_da_submit_io(struct mpage_da_data *mpd)
1907{
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04001908 long pages_skipped;
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001909 struct pagevec pvec;
1910 unsigned long index, end;
1911 int ret = 0, err, nr_pages, i;
1912 struct inode *inode = mpd->inode;
1913 struct address_space *mapping = inode->i_mapping;
Alex Tomas64769242008-07-11 19:27:31 -04001914
1915 BUG_ON(mpd->next_page <= mpd->first_page);
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001916 /*
1917 * We need to start from the first_page to the next_page - 1
1918 * to make sure we also write the mapped dirty buffer_heads.
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05001919 * If we look at mpd->b_blocknr we would only be looking
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001920 * at the currently mapped buffer_heads.
1921 */
Alex Tomas64769242008-07-11 19:27:31 -04001922 index = mpd->first_page;
1923 end = mpd->next_page - 1;
1924
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001925 pagevec_init(&pvec, 0);
Alex Tomas64769242008-07-11 19:27:31 -04001926 while (index <= end) {
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001927 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
Alex Tomas64769242008-07-11 19:27:31 -04001928 if (nr_pages == 0)
1929 break;
1930 for (i = 0; i < nr_pages; i++) {
1931 struct page *page = pvec.pages[i];
1932
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001933 index = page->index;
1934 if (index > end)
1935 break;
1936 index++;
1937
1938 BUG_ON(!PageLocked(page));
1939 BUG_ON(PageWriteback(page));
1940
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04001941 pages_skipped = mpd->wbc->pages_skipped;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001942 err = mapping->a_ops->writepage(page, mpd->wbc);
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04001943 if (!err && (pages_skipped == mpd->wbc->pages_skipped))
1944 /*
1945 * have successfully written the page
1946 * without skipping the same
1947 */
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001948 mpd->pages_written++;
Alex Tomas64769242008-07-11 19:27:31 -04001949 /*
1950 * In error case, we have to continue because
1951 * remaining pages are still locked
1952 * XXX: unlock and re-dirty them?
1953 */
1954 if (ret == 0)
1955 ret = err;
1956 }
1957 pagevec_release(&pvec);
1958 }
Alex Tomas64769242008-07-11 19:27:31 -04001959 return ret;
1960}
1961
1962/*
1963 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
1964 *
1965 * @mpd->inode - inode to walk through
1966 * @exbh->b_blocknr - first block on a disk
1967 * @exbh->b_size - amount of space in bytes
1968 * @logical - first logical block to start assignment with
1969 *
1970 * the function goes through all passed space and put actual disk
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04001971 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
Alex Tomas64769242008-07-11 19:27:31 -04001972 */
1973static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
1974 struct buffer_head *exbh)
1975{
1976 struct inode *inode = mpd->inode;
1977 struct address_space *mapping = inode->i_mapping;
1978 int blocks = exbh->b_size >> inode->i_blkbits;
1979 sector_t pblock = exbh->b_blocknr, cur_logical;
1980 struct buffer_head *head, *bh;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001981 pgoff_t index, end;
Alex Tomas64769242008-07-11 19:27:31 -04001982 struct pagevec pvec;
1983 int nr_pages, i;
1984
1985 index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
1986 end = (logical + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
1987 cur_logical = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1988
1989 pagevec_init(&pvec, 0);
1990
1991 while (index <= end) {
1992 /* XXX: optimize tail */
1993 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1994 if (nr_pages == 0)
1995 break;
1996 for (i = 0; i < nr_pages; i++) {
1997 struct page *page = pvec.pages[i];
1998
1999 index = page->index;
2000 if (index > end)
2001 break;
2002 index++;
2003
2004 BUG_ON(!PageLocked(page));
2005 BUG_ON(PageWriteback(page));
2006 BUG_ON(!page_has_buffers(page));
2007
2008 bh = page_buffers(page);
2009 head = bh;
2010
2011 /* skip blocks out of the range */
2012 do {
2013 if (cur_logical >= logical)
2014 break;
2015 cur_logical++;
2016 } while ((bh = bh->b_this_page) != head);
2017
2018 do {
2019 if (cur_logical >= logical + blocks)
2020 break;
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002021
2022 if (buffer_delay(bh) ||
2023 buffer_unwritten(bh)) {
2024
2025 BUG_ON(bh->b_bdev != inode->i_sb->s_bdev);
2026
2027 if (buffer_delay(bh)) {
2028 clear_buffer_delay(bh);
2029 bh->b_blocknr = pblock;
2030 } else {
2031 /*
2032 * unwritten already should have
2033 * blocknr assigned. Verify that
2034 */
2035 clear_buffer_unwritten(bh);
2036 BUG_ON(bh->b_blocknr != pblock);
2037 }
2038
Mingming Cao61628a32008-07-11 19:27:31 -04002039 } else if (buffer_mapped(bh))
Alex Tomas64769242008-07-11 19:27:31 -04002040 BUG_ON(bh->b_blocknr != pblock);
Alex Tomas64769242008-07-11 19:27:31 -04002041
2042 cur_logical++;
2043 pblock++;
2044 } while ((bh = bh->b_this_page) != head);
2045 }
2046 pagevec_release(&pvec);
2047 }
2048}
2049
2050
2051/*
2052 * __unmap_underlying_blocks - just a helper function to unmap
2053 * set of blocks described by @bh
2054 */
2055static inline void __unmap_underlying_blocks(struct inode *inode,
2056 struct buffer_head *bh)
2057{
2058 struct block_device *bdev = inode->i_sb->s_bdev;
2059 int blocks, i;
2060
2061 blocks = bh->b_size >> inode->i_blkbits;
2062 for (i = 0; i < blocks; i++)
2063 unmap_underlying_metadata(bdev, bh->b_blocknr + i);
2064}
2065
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002066static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
2067 sector_t logical, long blk_cnt)
2068{
2069 int nr_pages, i;
2070 pgoff_t index, end;
2071 struct pagevec pvec;
2072 struct inode *inode = mpd->inode;
2073 struct address_space *mapping = inode->i_mapping;
2074
2075 index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
2076 end = (logical + blk_cnt - 1) >>
2077 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2078 while (index <= end) {
2079 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2080 if (nr_pages == 0)
2081 break;
2082 for (i = 0; i < nr_pages; i++) {
2083 struct page *page = pvec.pages[i];
2084 index = page->index;
2085 if (index > end)
2086 break;
2087 index++;
2088
2089 BUG_ON(!PageLocked(page));
2090 BUG_ON(PageWriteback(page));
2091 block_invalidatepage(page, 0);
2092 ClearPageUptodate(page);
2093 unlock_page(page);
2094 }
2095 }
2096 return;
2097}
2098
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002099static void ext4_print_free_blocks(struct inode *inode)
2100{
2101 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2102 printk(KERN_EMERG "Total free blocks count %lld\n",
2103 ext4_count_free_blocks(inode->i_sb));
2104 printk(KERN_EMERG "Free/Dirty block details\n");
2105 printk(KERN_EMERG "free_blocks=%lld\n",
Alexander Beregalov8f72fbd2008-10-29 17:13:08 -04002106 (long long)percpu_counter_sum(&sbi->s_freeblocks_counter));
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002107 printk(KERN_EMERG "dirty_blocks=%lld\n",
Alexander Beregalov8f72fbd2008-10-29 17:13:08 -04002108 (long long)percpu_counter_sum(&sbi->s_dirtyblocks_counter));
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002109 printk(KERN_EMERG "Block reservation details\n");
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002110 printk(KERN_EMERG "i_reserved_data_blocks=%u\n",
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002111 EXT4_I(inode)->i_reserved_data_blocks);
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002112 printk(KERN_EMERG "i_reserved_meta_blocks=%u\n",
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002113 EXT4_I(inode)->i_reserved_meta_blocks);
2114 return;
2115}
2116
Theodore Ts'ob920c752009-05-14 00:54:29 -04002117/*
Alex Tomas64769242008-07-11 19:27:31 -04002118 * mpage_da_map_blocks - go through given space
2119 *
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002120 * @mpd - bh describing space
Alex Tomas64769242008-07-11 19:27:31 -04002121 *
2122 * The function skips space we know is already mapped to disk blocks.
2123 *
Alex Tomas64769242008-07-11 19:27:31 -04002124 */
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002125static int mpage_da_map_blocks(struct mpage_da_data *mpd)
Alex Tomas64769242008-07-11 19:27:31 -04002126{
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002127 int err, blks, get_blocks_flags;
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04002128 struct buffer_head new;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002129 sector_t next = mpd->b_blocknr;
2130 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
2131 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
2132 handle_t *handle = NULL;
Alex Tomas64769242008-07-11 19:27:31 -04002133
2134 /*
2135 * We consider only non-mapped and non-allocated blocks
2136 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002137 if ((mpd->b_state & (1 << BH_Mapped)) &&
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002138 !(mpd->b_state & (1 << BH_Delay)) &&
2139 !(mpd->b_state & (1 << BH_Unwritten)))
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002140 return 0;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002141
2142 /*
2143 * If we didn't accumulate anything to write simply return
2144 */
2145 if (!mpd->b_size)
2146 return 0;
2147
2148 handle = ext4_journal_current_handle();
2149 BUG_ON(!handle);
2150
Aneesh Kumar K.V79ffab32009-05-13 15:13:42 -04002151 /*
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002152 * Call ext4_get_blocks() to allocate any delayed allocation
2153 * blocks, or to convert an uninitialized extent to be
2154 * initialized (in the case where we have written into
2155 * one or more preallocated blocks).
2156 *
2157 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2158 * indicate that we are on the delayed allocation path. This
2159 * affects functions in many different parts of the allocation
2160 * call path. This flag exists primarily because we don't
2161 * want to change *many* call functions, so ext4_get_blocks()
2162 * will set the magic i_delalloc_reserved_flag once the
2163 * inode's allocation semaphore is taken.
2164 *
2165 * If the blocks in questions were delalloc blocks, set
2166 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2167 * variables are updated after the blocks have been allocated.
Aneesh Kumar K.V79ffab32009-05-13 15:13:42 -04002168 */
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002169 new.b_state = 0;
2170 get_blocks_flags = (EXT4_GET_BLOCKS_CREATE |
2171 EXT4_GET_BLOCKS_DELALLOC_RESERVE);
2172 if (mpd->b_state & (1 << BH_Delay))
2173 get_blocks_flags |= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002174 blks = ext4_get_blocks(handle, mpd->inode, next, max_blocks,
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002175 &new, get_blocks_flags);
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002176 if (blks < 0) {
2177 err = blks;
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002178 /*
2179 * If get block returns with error we simply
2180 * return. Later writepage will redirty the page and
2181 * writepages will find the dirty page again
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002182 */
2183 if (err == -EAGAIN)
2184 return 0;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002185
2186 if (err == -ENOSPC &&
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002187 ext4_count_free_blocks(mpd->inode->i_sb)) {
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002188 mpd->retval = err;
2189 return 0;
2190 }
2191
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002192 /*
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002193 * get block failure will cause us to loop in
2194 * writepages, because a_ops->writepage won't be able
2195 * to make progress. The page will be redirtied by
2196 * writepage and writepages will again try to write
2197 * the same.
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002198 */
2199 printk(KERN_EMERG "%s block allocation failed for inode %lu "
2200 "at logical offset %llu with max blocks "
2201 "%zd with error %d\n",
2202 __func__, mpd->inode->i_ino,
2203 (unsigned long long)next,
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002204 mpd->b_size >> mpd->inode->i_blkbits, err);
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002205 printk(KERN_EMERG "This should not happen.!! "
2206 "Data will be lost\n");
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04002207 if (err == -ENOSPC) {
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002208 ext4_print_free_blocks(mpd->inode);
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04002209 }
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002210 /* invalidate all the pages */
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002211 ext4_da_block_invalidatepages(mpd, next,
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002212 mpd->b_size >> mpd->inode->i_blkbits);
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002213 return err;
2214 }
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002215 BUG_ON(blks == 0);
2216
2217 new.b_size = (blks << mpd->inode->i_blkbits);
Alex Tomas64769242008-07-11 19:27:31 -04002218
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002219 if (buffer_new(&new))
2220 __unmap_underlying_blocks(mpd->inode, &new);
Alex Tomas64769242008-07-11 19:27:31 -04002221
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002222 /*
2223 * If blocks are delayed marked, we need to
2224 * put actual blocknr and drop delayed bit
2225 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002226 if ((mpd->b_state & (1 << BH_Delay)) ||
2227 (mpd->b_state & (1 << BH_Unwritten)))
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002228 mpage_put_bnr_to_bhs(mpd, next, &new);
2229
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002230 if (ext4_should_order_data(mpd->inode)) {
2231 err = ext4_jbd2_file_inode(handle, mpd->inode);
2232 if (err)
2233 return err;
2234 }
2235
2236 /*
Jan Kara03f5d8b2009-06-09 00:17:05 -04002237 * Update on-disk size along with block allocation.
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002238 */
2239 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
2240 if (disksize > i_size_read(mpd->inode))
2241 disksize = i_size_read(mpd->inode);
2242 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
2243 ext4_update_i_disksize(mpd->inode, disksize);
2244 return ext4_mark_inode_dirty(handle, mpd->inode);
2245 }
2246
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002247 return 0;
Alex Tomas64769242008-07-11 19:27:31 -04002248}
2249
Aneesh Kumar K.Vbf068ee2008-08-19 22:16:43 -04002250#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2251 (1 << BH_Delay) | (1 << BH_Unwritten))
Alex Tomas64769242008-07-11 19:27:31 -04002252
2253/*
2254 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2255 *
2256 * @mpd->lbh - extent of blocks
2257 * @logical - logical number of the block in the file
2258 * @bh - bh of the block (used to access block's state)
2259 *
2260 * the function is used to collect contig. blocks in same state
2261 */
2262static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002263 sector_t logical, size_t b_size,
2264 unsigned long b_state)
Alex Tomas64769242008-07-11 19:27:31 -04002265{
Alex Tomas64769242008-07-11 19:27:31 -04002266 sector_t next;
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002267 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
Alex Tomas64769242008-07-11 19:27:31 -04002268
Mingming Cao525f4ed2008-08-19 22:15:58 -04002269 /* check if thereserved journal credits might overflow */
2270 if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL)) {
2271 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
2272 /*
2273 * With non-extent format we are limited by the journal
2274 * credit available. Total credit needed to insert
2275 * nrblocks contiguous blocks is dependent on the
2276 * nrblocks. So limit nrblocks.
2277 */
2278 goto flush_it;
2279 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
2280 EXT4_MAX_TRANS_DATA) {
2281 /*
2282 * Adding the new buffer_head would make it cross the
2283 * allowed limit for which we have journal credit
2284 * reserved. So limit the new bh->b_size
2285 */
2286 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
2287 mpd->inode->i_blkbits;
2288 /* we will do mpage_da_submit_io in the next loop */
2289 }
2290 }
Alex Tomas64769242008-07-11 19:27:31 -04002291 /*
2292 * First block in the extent
2293 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002294 if (mpd->b_size == 0) {
2295 mpd->b_blocknr = logical;
2296 mpd->b_size = b_size;
2297 mpd->b_state = b_state & BH_FLAGS;
Alex Tomas64769242008-07-11 19:27:31 -04002298 return;
2299 }
2300
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002301 next = mpd->b_blocknr + nrblocks;
Alex Tomas64769242008-07-11 19:27:31 -04002302 /*
2303 * Can we merge the block to our big extent?
2304 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002305 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
2306 mpd->b_size += b_size;
Alex Tomas64769242008-07-11 19:27:31 -04002307 return;
2308 }
2309
Mingming Cao525f4ed2008-08-19 22:15:58 -04002310flush_it:
Alex Tomas64769242008-07-11 19:27:31 -04002311 /*
2312 * We couldn't merge the block to our extent, so we
2313 * need to flush current extent and start new one
2314 */
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002315 if (mpage_da_map_blocks(mpd) == 0)
2316 mpage_da_submit_io(mpd);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002317 mpd->io_done = 1;
2318 return;
Alex Tomas64769242008-07-11 19:27:31 -04002319}
2320
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002321static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
2322{
2323 /*
2324 * unmapped buffer is possible for holes.
2325 * delay buffer is possible with delayed allocation.
2326 * We also need to consider unwritten buffer as unmapped.
2327 */
2328 return (!buffer_mapped(bh) || buffer_delay(bh) ||
2329 buffer_unwritten(bh)) && buffer_dirty(bh);
2330}
2331
Alex Tomas64769242008-07-11 19:27:31 -04002332/*
2333 * __mpage_da_writepage - finds extent of pages and blocks
2334 *
2335 * @page: page to consider
2336 * @wbc: not used, we just follow rules
2337 * @data: context
2338 *
2339 * The function finds extents of pages and scan them for all blocks.
2340 */
2341static int __mpage_da_writepage(struct page *page,
2342 struct writeback_control *wbc, void *data)
2343{
2344 struct mpage_da_data *mpd = data;
2345 struct inode *inode = mpd->inode;
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002346 struct buffer_head *bh, *head;
Alex Tomas64769242008-07-11 19:27:31 -04002347 sector_t logical;
2348
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002349 if (mpd->io_done) {
2350 /*
2351 * Rest of the page in the page_vec
2352 * redirty then and skip then. We will
2353 * try to to write them again after
2354 * starting a new transaction
2355 */
2356 redirty_page_for_writepage(wbc, page);
2357 unlock_page(page);
2358 return MPAGE_DA_EXTENT_TAIL;
2359 }
Alex Tomas64769242008-07-11 19:27:31 -04002360 /*
2361 * Can we merge this page to current extent?
2362 */
2363 if (mpd->next_page != page->index) {
2364 /*
2365 * Nope, we can't. So, we map non-allocated blocks
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002366 * and start IO on them using writepage()
Alex Tomas64769242008-07-11 19:27:31 -04002367 */
2368 if (mpd->next_page != mpd->first_page) {
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002369 if (mpage_da_map_blocks(mpd) == 0)
2370 mpage_da_submit_io(mpd);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002371 /*
2372 * skip rest of the page in the page_vec
2373 */
2374 mpd->io_done = 1;
2375 redirty_page_for_writepage(wbc, page);
2376 unlock_page(page);
2377 return MPAGE_DA_EXTENT_TAIL;
Alex Tomas64769242008-07-11 19:27:31 -04002378 }
2379
2380 /*
2381 * Start next extent of pages ...
2382 */
2383 mpd->first_page = page->index;
2384
2385 /*
2386 * ... and blocks
2387 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002388 mpd->b_size = 0;
2389 mpd->b_state = 0;
2390 mpd->b_blocknr = 0;
Alex Tomas64769242008-07-11 19:27:31 -04002391 }
2392
2393 mpd->next_page = page->index + 1;
2394 logical = (sector_t) page->index <<
2395 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2396
2397 if (!page_has_buffers(page)) {
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002398 mpage_add_bh_to_extent(mpd, logical, PAGE_CACHE_SIZE,
2399 (1 << BH_Dirty) | (1 << BH_Uptodate));
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002400 if (mpd->io_done)
2401 return MPAGE_DA_EXTENT_TAIL;
Alex Tomas64769242008-07-11 19:27:31 -04002402 } else {
2403 /*
2404 * Page with regular buffer heads, just add all dirty ones
2405 */
2406 head = page_buffers(page);
2407 bh = head;
2408 do {
2409 BUG_ON(buffer_locked(bh));
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002410 /*
2411 * We need to try to allocate
2412 * unmapped blocks in the same page.
2413 * Otherwise we won't make progress
2414 * with the page in ext4_da_writepage
2415 */
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002416 if (ext4_bh_unmapped_or_delay(NULL, bh)) {
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002417 mpage_add_bh_to_extent(mpd, logical,
2418 bh->b_size,
2419 bh->b_state);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002420 if (mpd->io_done)
2421 return MPAGE_DA_EXTENT_TAIL;
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002422 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2423 /*
2424 * mapped dirty buffer. We need to update
2425 * the b_state because we look at
2426 * b_state in mpage_da_map_blocks. We don't
2427 * update b_size because if we find an
2428 * unmapped buffer_head later we need to
2429 * use the b_state flag of that buffer_head.
2430 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002431 if (mpd->b_size == 0)
2432 mpd->b_state = bh->b_state & BH_FLAGS;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002433 }
Alex Tomas64769242008-07-11 19:27:31 -04002434 logical++;
2435 } while ((bh = bh->b_this_page) != head);
2436 }
2437
2438 return 0;
2439}
2440
2441/*
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,
2454 struct buffer_head *bh_result, int create)
2455{
2456 int ret = 0;
Aneesh Kumar K.V33b98172009-05-12 14:40:37 -04002457 sector_t invalid_block = ~((sector_t) 0xffff);
2458
2459 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
2460 invalid_block = ~0;
Alex Tomas64769242008-07-11 19:27:31 -04002461
2462 BUG_ON(create == 0);
2463 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
2464
2465 /*
2466 * first, we need to know whether the block is allocated already
2467 * preallocated blocks are unmapped but should treated
2468 * the same as allocated blocks.
2469 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04002470 ret = ext4_get_blocks(NULL, inode, iblock, 1, bh_result, 0);
Mingming Caod2a17632008-07-14 17:52:37 -04002471 if ((ret == 0) && !buffer_delay(bh_result)) {
2472 /* the block isn't (pre)allocated yet, let's reserve space */
Alex Tomas64769242008-07-11 19:27:31 -04002473 /*
2474 * XXX: __block_prepare_write() unmaps passed block,
2475 * is it OK?
2476 */
Mingming Caod2a17632008-07-14 17:52:37 -04002477 ret = ext4_da_reserve_space(inode, 1);
2478 if (ret)
2479 /* not enough space to reserve */
2480 return ret;
2481
Aneesh Kumar K.V33b98172009-05-12 14:40:37 -04002482 map_bh(bh_result, inode->i_sb, invalid_block);
Alex Tomas64769242008-07-11 19:27:31 -04002483 set_buffer_new(bh_result);
2484 set_buffer_delay(bh_result);
2485 } else if (ret > 0) {
2486 bh_result->b_size = (ret << inode->i_blkbits);
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002487 if (buffer_unwritten(bh_result)) {
2488 /* A delayed write to unwritten bh should
2489 * be marked new and mapped. Mapped ensures
2490 * that we don't do get_block multiple times
2491 * when we write to the same offset and new
2492 * ensures that we do proper zero out for
2493 * partial write.
2494 */
Aneesh Kumar K.V9c1ee182009-05-13 18:36:58 -04002495 set_buffer_new(bh_result);
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002496 set_buffer_mapped(bh_result);
2497 }
Alex Tomas64769242008-07-11 19:27:31 -04002498 ret = 0;
2499 }
2500
2501 return ret;
2502}
Mingming Cao61628a32008-07-11 19:27:31 -04002503
Theodore Ts'ob920c752009-05-14 00:54:29 -04002504/*
2505 * This function is used as a standard get_block_t calback function
2506 * when there is no desire to allocate any blocks. It is used as a
2507 * callback function for block_prepare_write(), nobh_writepage(), and
2508 * block_write_full_page(). These functions should only try to map a
2509 * single block at a time.
2510 *
2511 * Since this function doesn't do block allocations even if the caller
2512 * requests it by passing in create=1, it is critically important that
2513 * any caller checks to make sure that any buffer heads are returned
2514 * by this function are either all already mapped or marked for
2515 * delayed allocation before calling nobh_writepage() or
2516 * block_write_full_page(). Otherwise, b_blocknr could be left
2517 * unitialized, and the page write functions will be taken by
2518 * surprise.
2519 */
2520static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002521 struct buffer_head *bh_result, int create)
2522{
2523 int ret = 0;
2524 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
2525
Theodore Ts'oa2dc52b2009-05-12 13:51:29 -04002526 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
2527
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002528 /*
2529 * we don't want to do block allocation in writepage
2530 * so call get_block_wrap with create = 0
2531 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04002532 ret = ext4_get_blocks(NULL, inode, iblock, max_blocks, bh_result, 0);
Theodore Ts'oa2dc52b2009-05-12 13:51:29 -04002533 BUG_ON(create && ret == 0);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002534 if (ret > 0) {
2535 bh_result->b_size = (ret << inode->i_blkbits);
2536 ret = 0;
2537 }
2538 return ret;
Mingming Cao61628a32008-07-11 19:27:31 -04002539}
2540
Mingming Cao61628a32008-07-11 19:27:31 -04002541/*
Theodore Ts'ob920c752009-05-14 00:54:29 -04002542 * This function can get called via...
2543 * - ext4_da_writepages after taking page lock (have journal handle)
2544 * - journal_submit_inode_data_buffers (no journal handle)
2545 * - shrink_page_list via pdflush (no journal handle)
2546 * - grab_page_cache when doing write_begin (have journal handle)
Mingming Cao61628a32008-07-11 19:27:31 -04002547 */
Alex Tomas64769242008-07-11 19:27:31 -04002548static int ext4_da_writepage(struct page *page,
2549 struct writeback_control *wbc)
2550{
Alex Tomas64769242008-07-11 19:27:31 -04002551 int ret = 0;
Mingming Cao61628a32008-07-11 19:27:31 -04002552 loff_t size;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002553 unsigned int len;
Mingming Cao61628a32008-07-11 19:27:31 -04002554 struct buffer_head *page_bufs;
2555 struct inode *inode = page->mapping->host;
Alex Tomas64769242008-07-11 19:27:31 -04002556
Theodore Ts'oba80b102009-01-03 20:03:21 -05002557 trace_mark(ext4_da_writepage,
2558 "dev %s ino %lu page_index %lu",
2559 inode->i_sb->s_id, inode->i_ino, page->index);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002560 size = i_size_read(inode);
2561 if (page->index == size >> PAGE_CACHE_SHIFT)
2562 len = size & ~PAGE_CACHE_MASK;
2563 else
2564 len = PAGE_CACHE_SIZE;
Alex Tomas64769242008-07-11 19:27:31 -04002565
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002566 if (page_has_buffers(page)) {
Mingming Cao61628a32008-07-11 19:27:31 -04002567 page_bufs = page_buffers(page);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002568 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2569 ext4_bh_unmapped_or_delay)) {
Mingming Cao61628a32008-07-11 19:27:31 -04002570 /*
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002571 * We don't want to do block allocation
2572 * So redirty the page and return
Aneesh Kumar K.Vcd1aac32008-07-11 19:27:31 -04002573 * We may reach here when we do a journal commit
2574 * via journal_submit_inode_data_buffers.
2575 * If we don't have mapping block we just ignore
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002576 * them. We can also reach here via shrink_page_list
2577 */
2578 redirty_page_for_writepage(wbc, page);
2579 unlock_page(page);
2580 return 0;
2581 }
2582 } else {
2583 /*
2584 * The test for page_has_buffers() is subtle:
2585 * We know the page is dirty but it lost buffers. That means
2586 * that at some moment in time after write_begin()/write_end()
2587 * has been called all buffers have been clean and thus they
2588 * must have been written at least once. So they are all
2589 * mapped and we can happily proceed with mapping them
2590 * and writing the page.
2591 *
2592 * Try to initialize the buffer_heads and check whether
2593 * all are mapped and non delay. We don't want to
2594 * do block allocation here.
2595 */
2596 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
Theodore Ts'ob920c752009-05-14 00:54:29 -04002597 noalloc_get_block_write);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002598 if (!ret) {
2599 page_bufs = page_buffers(page);
2600 /* check whether all are mapped and non delay */
2601 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2602 ext4_bh_unmapped_or_delay)) {
2603 redirty_page_for_writepage(wbc, page);
2604 unlock_page(page);
2605 return 0;
2606 }
2607 } else {
2608 /*
2609 * We can't do block allocation here
2610 * so just redity the page and unlock
2611 * and return
Mingming Cao61628a32008-07-11 19:27:31 -04002612 */
Mingming Cao61628a32008-07-11 19:27:31 -04002613 redirty_page_for_writepage(wbc, page);
2614 unlock_page(page);
2615 return 0;
2616 }
Aneesh Kumar K.Ved9b3e32008-11-07 09:06:45 -05002617 /* now mark the buffer_heads as dirty and uptodate */
2618 block_commit_write(page, 0, PAGE_CACHE_SIZE);
Alex Tomas64769242008-07-11 19:27:31 -04002619 }
2620
2621 if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
Theodore Ts'ob920c752009-05-14 00:54:29 -04002622 ret = nobh_writepage(page, noalloc_get_block_write, wbc);
Alex Tomas64769242008-07-11 19:27:31 -04002623 else
Theodore Ts'ob920c752009-05-14 00:54:29 -04002624 ret = block_write_full_page(page, noalloc_get_block_write,
2625 wbc);
Alex Tomas64769242008-07-11 19:27:31 -04002626
Alex Tomas64769242008-07-11 19:27:31 -04002627 return ret;
2628}
2629
Mingming Cao61628a32008-07-11 19:27:31 -04002630/*
Mingming Cao525f4ed2008-08-19 22:15:58 -04002631 * This is called via ext4_da_writepages() to
2632 * calulate the total number of credits to reserve to fit
2633 * a single extent allocation into a single transaction,
2634 * ext4_da_writpeages() will loop calling this before
2635 * the block allocation.
Mingming Cao61628a32008-07-11 19:27:31 -04002636 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04002637
2638static int ext4_da_writepages_trans_blocks(struct inode *inode)
2639{
2640 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2641
2642 /*
2643 * With non-extent format the journal credit needed to
2644 * insert nrblocks contiguous block is dependent on
2645 * number of contiguous block. So we will limit
2646 * number of contiguous block to a sane value
2647 */
2648 if (!(inode->i_flags & EXT4_EXTENTS_FL) &&
2649 (max_blocks > EXT4_MAX_TRANS_DATA))
2650 max_blocks = EXT4_MAX_TRANS_DATA;
2651
2652 return ext4_chunk_trans_blocks(inode, max_blocks);
2653}
Mingming Cao61628a32008-07-11 19:27:31 -04002654
Alex Tomas64769242008-07-11 19:27:31 -04002655static int ext4_da_writepages(struct address_space *mapping,
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002656 struct writeback_control *wbc)
Alex Tomas64769242008-07-11 19:27:31 -04002657{
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002658 pgoff_t index;
2659 int range_whole = 0;
Mingming Cao61628a32008-07-11 19:27:31 -04002660 handle_t *handle = NULL;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002661 struct mpage_da_data mpd;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002662 struct inode *inode = mapping->host;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002663 int no_nrwrite_index_update;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002664 int pages_written = 0;
2665 long pages_skipped;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002666 int range_cyclic, cycled = 1, io_done = 0;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002667 int needed_blocks, ret = 0, nr_to_writebump = 0;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002668 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
Mingming Cao61628a32008-07-11 19:27:31 -04002669
Theodore Ts'oba80b102009-01-03 20:03:21 -05002670 trace_mark(ext4_da_writepages,
2671 "dev %s ino %lu nr_t_write %ld "
2672 "pages_skipped %ld range_start %llu "
2673 "range_end %llu nonblocking %d "
2674 "for_kupdate %d for_reclaim %d "
2675 "for_writepages %d range_cyclic %d",
2676 inode->i_sb->s_id, inode->i_ino,
2677 wbc->nr_to_write, wbc->pages_skipped,
2678 (unsigned long long) wbc->range_start,
2679 (unsigned long long) wbc->range_end,
2680 wbc->nonblocking, wbc->for_kupdate,
2681 wbc->for_reclaim, wbc->for_writepages,
2682 wbc->range_cyclic);
2683
Mingming Cao61628a32008-07-11 19:27:31 -04002684 /*
2685 * No pages to write? This is mainly a kludge to avoid starting
2686 * a transaction for special inodes like journal inode on last iput()
2687 * because that could violate lock ordering on umount
2688 */
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002689 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
Mingming Cao61628a32008-07-11 19:27:31 -04002690 return 0;
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002691
2692 /*
2693 * If the filesystem has aborted, it is read-only, so return
2694 * right away instead of dumping stack traces later on that
2695 * will obscure the real source of the problem. We test
2696 * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because
2697 * the latter could be true if the filesystem is mounted
2698 * read-only, and in that case, ext4_da_writepages should
2699 * *never* be called, so if that ever happens, we would want
2700 * the stack trace.
2701 */
2702 if (unlikely(sbi->s_mount_opt & EXT4_MOUNT_ABORT))
2703 return -EROFS;
2704
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002705 /*
2706 * Make sure nr_to_write is >= sbi->s_mb_stream_request
2707 * This make sure small files blocks are allocated in
2708 * single attempt. This ensure that small files
2709 * get less fragmented.
2710 */
2711 if (wbc->nr_to_write < sbi->s_mb_stream_request) {
2712 nr_to_writebump = sbi->s_mb_stream_request - wbc->nr_to_write;
2713 wbc->nr_to_write = sbi->s_mb_stream_request;
2714 }
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002715 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2716 range_whole = 1;
Mingming Cao61628a32008-07-11 19:27:31 -04002717
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002718 range_cyclic = wbc->range_cyclic;
2719 if (wbc->range_cyclic) {
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002720 index = mapping->writeback_index;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002721 if (index)
2722 cycled = 0;
2723 wbc->range_start = index << PAGE_CACHE_SHIFT;
2724 wbc->range_end = LLONG_MAX;
2725 wbc->range_cyclic = 0;
2726 } else
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002727 index = wbc->range_start >> PAGE_CACHE_SHIFT;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002728
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002729 mpd.wbc = wbc;
2730 mpd.inode = mapping->host;
2731
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002732 /*
2733 * we don't want write_cache_pages to update
2734 * nr_to_write and writeback_index
2735 */
2736 no_nrwrite_index_update = wbc->no_nrwrite_index_update;
2737 wbc->no_nrwrite_index_update = 1;
2738 pages_skipped = wbc->pages_skipped;
2739
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002740retry:
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002741 while (!ret && wbc->nr_to_write > 0) {
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002742
2743 /*
2744 * we insert one extent at a time. So we need
2745 * credit needed for single extent allocation.
2746 * journalled mode is currently not supported
2747 * by delalloc
2748 */
2749 BUG_ON(ext4_should_journal_data(inode));
Mingming Cao525f4ed2008-08-19 22:15:58 -04002750 needed_blocks = ext4_da_writepages_trans_blocks(inode);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002751
Mingming Cao61628a32008-07-11 19:27:31 -04002752 /* start a new transaction*/
2753 handle = ext4_journal_start(inode, needed_blocks);
2754 if (IS_ERR(handle)) {
2755 ret = PTR_ERR(handle);
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002756 printk(KERN_CRIT "%s: jbd2_start: "
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002757 "%ld pages, ino %lu; err %d\n", __func__,
2758 wbc->nr_to_write, inode->i_ino, ret);
2759 dump_stack();
Mingming Cao61628a32008-07-11 19:27:31 -04002760 goto out_writepages;
2761 }
Theodore Ts'of63e6002009-02-23 16:42:39 -05002762
2763 /*
2764 * Now call __mpage_da_writepage to find the next
2765 * contiguous region of logical blocks that need
2766 * blocks to be allocated by ext4. We don't actually
2767 * submit the blocks for I/O here, even though
2768 * write_cache_pages thinks it will, and will set the
2769 * pages as clean for write before calling
2770 * __mpage_da_writepage().
2771 */
2772 mpd.b_size = 0;
2773 mpd.b_state = 0;
2774 mpd.b_blocknr = 0;
2775 mpd.first_page = 0;
2776 mpd.next_page = 0;
2777 mpd.io_done = 0;
2778 mpd.pages_written = 0;
2779 mpd.retval = 0;
2780 ret = write_cache_pages(mapping, wbc, __mpage_da_writepage,
2781 &mpd);
2782 /*
2783 * If we have a contigous extent of pages and we
2784 * haven't done the I/O yet, map the blocks and submit
2785 * them for I/O.
2786 */
2787 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
2788 if (mpage_da_map_blocks(&mpd) == 0)
2789 mpage_da_submit_io(&mpd);
2790 mpd.io_done = 1;
2791 ret = MPAGE_DA_EXTENT_TAIL;
2792 }
2793 wbc->nr_to_write -= mpd.pages_written;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002794
Mingming Cao61628a32008-07-11 19:27:31 -04002795 ext4_journal_stop(handle);
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002796
Eric Sandeen8f64b322009-02-26 00:57:35 -05002797 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002798 /* commit the transaction which would
2799 * free blocks released in the transaction
2800 * and try again
2801 */
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002802 jbd2_journal_force_commit_nested(sbi->s_journal);
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002803 wbc->pages_skipped = pages_skipped;
2804 ret = 0;
2805 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002806 /*
2807 * got one extent now try with
2808 * rest of the pages
2809 */
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002810 pages_written += mpd.pages_written;
2811 wbc->pages_skipped = pages_skipped;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002812 ret = 0;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002813 io_done = 1;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002814 } else if (wbc->nr_to_write)
Mingming Cao61628a32008-07-11 19:27:31 -04002815 /*
2816 * There is no more writeout needed
2817 * or we requested for a noblocking writeout
2818 * and we found the device congested
2819 */
Mingming Cao61628a32008-07-11 19:27:31 -04002820 break;
Mingming Cao61628a32008-07-11 19:27:31 -04002821 }
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002822 if (!io_done && !cycled) {
2823 cycled = 1;
2824 index = 0;
2825 wbc->range_start = index << PAGE_CACHE_SHIFT;
2826 wbc->range_end = mapping->writeback_index - 1;
2827 goto retry;
2828 }
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002829 if (pages_skipped != wbc->pages_skipped)
2830 printk(KERN_EMERG "This should not happen leaving %s "
2831 "with nr_to_write = %ld ret = %d\n",
2832 __func__, wbc->nr_to_write, ret);
Mingming Cao61628a32008-07-11 19:27:31 -04002833
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002834 /* Update index */
2835 index += pages_written;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002836 wbc->range_cyclic = range_cyclic;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002837 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2838 /*
2839 * set the writeback_index so that range_cyclic
2840 * mode will write it back later
2841 */
2842 mapping->writeback_index = index;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002843
Mingming Cao61628a32008-07-11 19:27:31 -04002844out_writepages:
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002845 if (!no_nrwrite_index_update)
2846 wbc->no_nrwrite_index_update = 0;
2847 wbc->nr_to_write -= nr_to_writebump;
Theodore Ts'oba80b102009-01-03 20:03:21 -05002848 trace_mark(ext4_da_writepage_result,
2849 "dev %s ino %lu ret %d pages_written %d "
2850 "pages_skipped %ld congestion %d "
2851 "more_io %d no_nrwrite_index_update %d",
2852 inode->i_sb->s_id, inode->i_ino, ret,
2853 pages_written, wbc->pages_skipped,
2854 wbc->encountered_congestion, wbc->more_io,
2855 wbc->no_nrwrite_index_update);
Mingming Cao61628a32008-07-11 19:27:31 -04002856 return ret;
Alex Tomas64769242008-07-11 19:27:31 -04002857}
2858
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04002859#define FALL_BACK_TO_NONDELALLOC 1
2860static int ext4_nonda_switch(struct super_block *sb)
2861{
2862 s64 free_blocks, dirty_blocks;
2863 struct ext4_sb_info *sbi = EXT4_SB(sb);
2864
2865 /*
2866 * switch to non delalloc mode if we are running low
2867 * on free block. The free block accounting via percpu
Eric Dumazet179f7eb2009-01-06 14:41:04 -08002868 * counters can get slightly wrong with percpu_counter_batch getting
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04002869 * accumulated on each CPU without updating global counters
2870 * Delalloc need an accurate free block accounting. So switch
2871 * to non delalloc when we are near to error range.
2872 */
2873 free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
2874 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter);
2875 if (2 * free_blocks < 3 * dirty_blocks ||
2876 free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) {
2877 /*
2878 * free block count is less that 150% of dirty blocks
2879 * or free blocks is less that watermark
2880 */
2881 return 1;
2882 }
2883 return 0;
2884}
2885
Alex Tomas64769242008-07-11 19:27:31 -04002886static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2887 loff_t pos, unsigned len, unsigned flags,
2888 struct page **pagep, void **fsdata)
2889{
Mingming Caod2a17632008-07-14 17:52:37 -04002890 int ret, retries = 0;
Alex Tomas64769242008-07-11 19:27:31 -04002891 struct page *page;
2892 pgoff_t index;
2893 unsigned from, to;
2894 struct inode *inode = mapping->host;
2895 handle_t *handle;
2896
2897 index = pos >> PAGE_CACHE_SHIFT;
2898 from = pos & (PAGE_CACHE_SIZE - 1);
2899 to = from + len;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04002900
2901 if (ext4_nonda_switch(inode->i_sb)) {
2902 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2903 return ext4_write_begin(file, mapping, pos,
2904 len, flags, pagep, fsdata);
2905 }
2906 *fsdata = (void *)0;
Theodore Ts'oba80b102009-01-03 20:03:21 -05002907
2908 trace_mark(ext4_da_write_begin,
2909 "dev %s ino %lu pos %llu len %u flags %u",
2910 inode->i_sb->s_id, inode->i_ino,
2911 (unsigned long long) pos, len, flags);
Mingming Caod2a17632008-07-14 17:52:37 -04002912retry:
Alex Tomas64769242008-07-11 19:27:31 -04002913 /*
2914 * With delayed allocation, we don't log the i_disksize update
2915 * if there is delayed block allocation. But we still need
2916 * to journalling the i_disksize update if writes to the end
2917 * of file which has an already mapped buffer.
2918 */
2919 handle = ext4_journal_start(inode, 1);
2920 if (IS_ERR(handle)) {
2921 ret = PTR_ERR(handle);
2922 goto out;
2923 }
Jan Karaebd36102009-02-22 21:09:59 -05002924 /* We cannot recurse into the filesystem as the transaction is already
2925 * started */
2926 flags |= AOP_FLAG_NOFS;
Alex Tomas64769242008-07-11 19:27:31 -04002927
Nick Piggin54566b22009-01-04 12:00:53 -08002928 page = grab_cache_page_write_begin(mapping, index, flags);
Eric Sandeend5a0d4f2008-08-02 18:51:06 -04002929 if (!page) {
2930 ext4_journal_stop(handle);
2931 ret = -ENOMEM;
2932 goto out;
2933 }
Alex Tomas64769242008-07-11 19:27:31 -04002934 *pagep = page;
2935
2936 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
Theodore Ts'ob920c752009-05-14 00:54:29 -04002937 ext4_da_get_block_prep);
Alex Tomas64769242008-07-11 19:27:31 -04002938 if (ret < 0) {
2939 unlock_page(page);
2940 ext4_journal_stop(handle);
2941 page_cache_release(page);
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04002942 /*
2943 * block_write_begin may have instantiated a few blocks
2944 * outside i_size. Trim these off again. Don't need
2945 * i_size_read because we hold i_mutex.
2946 */
2947 if (pos + len > inode->i_size)
2948 vmtruncate(inode, inode->i_size);
Alex Tomas64769242008-07-11 19:27:31 -04002949 }
2950
Mingming Caod2a17632008-07-14 17:52:37 -04002951 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
2952 goto retry;
Alex Tomas64769242008-07-11 19:27:31 -04002953out:
2954 return ret;
2955}
2956
Mingming Cao632eaea2008-07-11 19:27:31 -04002957/*
2958 * Check if we should update i_disksize
2959 * when write to the end of file but not require block allocation
2960 */
2961static int ext4_da_should_update_i_disksize(struct page *page,
2962 unsigned long offset)
2963{
2964 struct buffer_head *bh;
2965 struct inode *inode = page->mapping->host;
2966 unsigned int idx;
2967 int i;
2968
2969 bh = page_buffers(page);
2970 idx = offset >> inode->i_blkbits;
2971
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04002972 for (i = 0; i < idx; i++)
Mingming Cao632eaea2008-07-11 19:27:31 -04002973 bh = bh->b_this_page;
2974
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002975 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
Mingming Cao632eaea2008-07-11 19:27:31 -04002976 return 0;
2977 return 1;
2978}
2979
Alex Tomas64769242008-07-11 19:27:31 -04002980static int ext4_da_write_end(struct file *file,
2981 struct address_space *mapping,
2982 loff_t pos, unsigned len, unsigned copied,
2983 struct page *page, void *fsdata)
2984{
2985 struct inode *inode = mapping->host;
2986 int ret = 0, ret2;
2987 handle_t *handle = ext4_journal_current_handle();
2988 loff_t new_i_size;
Mingming Cao632eaea2008-07-11 19:27:31 -04002989 unsigned long start, end;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04002990 int write_mode = (int)(unsigned long)fsdata;
2991
2992 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
2993 if (ext4_should_order_data(inode)) {
2994 return ext4_ordered_write_end(file, mapping, pos,
2995 len, copied, page, fsdata);
2996 } else if (ext4_should_writeback_data(inode)) {
2997 return ext4_writeback_write_end(file, mapping, pos,
2998 len, copied, page, fsdata);
2999 } else {
3000 BUG();
3001 }
3002 }
Mingming Cao632eaea2008-07-11 19:27:31 -04003003
Theodore Ts'oba80b102009-01-03 20:03:21 -05003004 trace_mark(ext4_da_write_end,
3005 "dev %s ino %lu pos %llu len %u copied %u",
3006 inode->i_sb->s_id, inode->i_ino,
3007 (unsigned long long) pos, len, copied);
Mingming Cao632eaea2008-07-11 19:27:31 -04003008 start = pos & (PAGE_CACHE_SIZE - 1);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003009 end = start + copied - 1;
Alex Tomas64769242008-07-11 19:27:31 -04003010
3011 /*
3012 * generic_write_end() will run mark_inode_dirty() if i_size
3013 * changes. So let's piggyback the i_disksize mark_inode_dirty
3014 * into that.
3015 */
3016
3017 new_i_size = pos + copied;
Mingming Cao632eaea2008-07-11 19:27:31 -04003018 if (new_i_size > EXT4_I(inode)->i_disksize) {
3019 if (ext4_da_should_update_i_disksize(page, end)) {
3020 down_write(&EXT4_I(inode)->i_data_sem);
3021 if (new_i_size > EXT4_I(inode)->i_disksize) {
3022 /*
3023 * Updating i_disksize when extending file
3024 * without needing block allocation
3025 */
3026 if (ext4_should_order_data(inode))
3027 ret = ext4_jbd2_file_inode(handle,
3028 inode);
Alex Tomas64769242008-07-11 19:27:31 -04003029
Mingming Cao632eaea2008-07-11 19:27:31 -04003030 EXT4_I(inode)->i_disksize = new_i_size;
3031 }
3032 up_write(&EXT4_I(inode)->i_data_sem);
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04003033 /* We need to mark inode dirty even if
3034 * new_i_size is less that inode->i_size
3035 * bu greater than i_disksize.(hint delalloc)
3036 */
3037 ext4_mark_inode_dirty(handle, inode);
Alex Tomas64769242008-07-11 19:27:31 -04003038 }
Mingming Cao632eaea2008-07-11 19:27:31 -04003039 }
Alex Tomas64769242008-07-11 19:27:31 -04003040 ret2 = generic_write_end(file, mapping, pos, len, copied,
3041 page, fsdata);
3042 copied = ret2;
3043 if (ret2 < 0)
3044 ret = ret2;
3045 ret2 = ext4_journal_stop(handle);
3046 if (!ret)
3047 ret = ret2;
3048
3049 return ret ? ret : copied;
3050}
3051
3052static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
3053{
Alex Tomas64769242008-07-11 19:27:31 -04003054 /*
3055 * Drop reserved blocks
3056 */
3057 BUG_ON(!PageLocked(page));
3058 if (!page_has_buffers(page))
3059 goto out;
3060
Mingming Caod2a17632008-07-14 17:52:37 -04003061 ext4_da_page_release_reservation(page, offset);
Alex Tomas64769242008-07-11 19:27:31 -04003062
3063out:
3064 ext4_invalidatepage(page, offset);
3065
3066 return;
3067}
3068
Theodore Ts'occd25062009-02-26 01:04:07 -05003069/*
3070 * Force all delayed allocation blocks to be allocated for a given inode.
3071 */
3072int ext4_alloc_da_blocks(struct inode *inode)
3073{
3074 if (!EXT4_I(inode)->i_reserved_data_blocks &&
3075 !EXT4_I(inode)->i_reserved_meta_blocks)
3076 return 0;
3077
3078 /*
3079 * We do something simple for now. The filemap_flush() will
3080 * also start triggering a write of the data blocks, which is
3081 * not strictly speaking necessary (and for users of
3082 * laptop_mode, not even desirable). However, to do otherwise
3083 * would require replicating code paths in:
3084 *
3085 * ext4_da_writepages() ->
3086 * write_cache_pages() ---> (via passed in callback function)
3087 * __mpage_da_writepage() -->
3088 * mpage_add_bh_to_extent()
3089 * mpage_da_map_blocks()
3090 *
3091 * The problem is that write_cache_pages(), located in
3092 * mm/page-writeback.c, marks pages clean in preparation for
3093 * doing I/O, which is not desirable if we're not planning on
3094 * doing I/O at all.
3095 *
3096 * We could call write_cache_pages(), and then redirty all of
3097 * the pages by calling redirty_page_for_writeback() but that
3098 * would be ugly in the extreme. So instead we would need to
3099 * replicate parts of the code in the above functions,
3100 * simplifying them becuase we wouldn't actually intend to
3101 * write out the pages, but rather only collect contiguous
3102 * logical block extents, call the multi-block allocator, and
3103 * then update the buffer heads with the block allocations.
3104 *
3105 * For now, though, we'll cheat by calling filemap_flush(),
3106 * which will map the blocks, and start the I/O, but not
3107 * actually wait for the I/O to complete.
3108 */
3109 return filemap_flush(inode->i_mapping);
3110}
Alex Tomas64769242008-07-11 19:27:31 -04003111
3112/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003113 * bmap() is special. It gets used by applications such as lilo and by
3114 * the swapper to find the on-disk block of a specific piece of data.
3115 *
3116 * Naturally, this is dangerous if the block concerned is still in the
Mingming Cao617ba132006-10-11 01:20:53 -07003117 * journal. If somebody makes a swapfile on an ext4 data-journaling
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003118 * filesystem and enables swap, then they may get a nasty shock when the
3119 * data getting swapped to that swapfile suddenly gets overwritten by
3120 * the original zero's written out previously to the journal and
3121 * awaiting writeback in the kernel's buffer cache.
3122 *
3123 * So, if we see any bmap calls here on a modified, data-journaled file,
3124 * take extra steps to flush any blocks which might be in the cache.
3125 */
Mingming Cao617ba132006-10-11 01:20:53 -07003126static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003127{
3128 struct inode *inode = mapping->host;
3129 journal_t *journal;
3130 int err;
3131
Alex Tomas64769242008-07-11 19:27:31 -04003132 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3133 test_opt(inode->i_sb, DELALLOC)) {
3134 /*
3135 * With delalloc we want to sync the file
3136 * so that we can make sure we allocate
3137 * blocks for file
3138 */
3139 filemap_write_and_wait(mapping);
3140 }
3141
Frank Mayhar03901312009-01-07 00:06:22 -05003142 if (EXT4_JOURNAL(inode) && EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003143 /*
3144 * This is a REALLY heavyweight approach, but the use of
3145 * bmap on dirty files is expected to be extremely rare:
3146 * only if we run lilo or swapon on a freshly made file
3147 * do we expect this to happen.
3148 *
3149 * (bmap requires CAP_SYS_RAWIO so this does not
3150 * represent an unprivileged user DOS attack --- we'd be
3151 * in trouble if mortal users could trigger this path at
3152 * will.)
3153 *
Mingming Cao617ba132006-10-11 01:20:53 -07003154 * NB. EXT4_STATE_JDATA is not set on files other than
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003155 * regular files. If somebody wants to bmap a directory
3156 * or symlink and gets confused because the buffer
3157 * hasn't yet been flushed to disk, they deserve
3158 * everything they get.
3159 */
3160
Mingming Cao617ba132006-10-11 01:20:53 -07003161 EXT4_I(inode)->i_state &= ~EXT4_STATE_JDATA;
3162 journal = EXT4_JOURNAL(inode);
Mingming Caodab291a2006-10-11 01:21:01 -07003163 jbd2_journal_lock_updates(journal);
3164 err = jbd2_journal_flush(journal);
3165 jbd2_journal_unlock_updates(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003166
3167 if (err)
3168 return 0;
3169 }
3170
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003171 return generic_block_bmap(mapping, block, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003172}
3173
3174static int bget_one(handle_t *handle, struct buffer_head *bh)
3175{
3176 get_bh(bh);
3177 return 0;
3178}
3179
3180static int bput_one(handle_t *handle, struct buffer_head *bh)
3181{
3182 put_bh(bh);
3183 return 0;
3184}
3185
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003186/*
Jan Kara678aaf42008-07-11 19:27:31 -04003187 * Note that we don't need to start a transaction unless we're journaling data
3188 * because we should have holes filled from ext4_page_mkwrite(). We even don't
3189 * need to file the inode to the transaction's list in ordered mode because if
3190 * we are writing back data added by write(), the inode is already there and if
3191 * we are writing back data modified via mmap(), noone guarantees in which
3192 * transaction the data will hit the disk. In case we are journaling data, we
3193 * cannot start transaction directly because transaction start ranks above page
3194 * lock so we have to do some magic.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003195 *
Jan Kara678aaf42008-07-11 19:27:31 -04003196 * In all journaling modes block_write_full_page() will start the I/O.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003197 *
3198 * Problem:
3199 *
Mingming Cao617ba132006-10-11 01:20:53 -07003200 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
3201 * ext4_writepage()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003202 *
3203 * Similar for:
3204 *
Mingming Cao617ba132006-10-11 01:20:53 -07003205 * ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ...
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003206 *
Mingming Cao617ba132006-10-11 01:20:53 -07003207 * Same applies to ext4_get_block(). We will deadlock on various things like
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05003208 * lock_journal and i_data_sem
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003209 *
3210 * Setting PF_MEMALLOC here doesn't work - too many internal memory
3211 * allocations fail.
3212 *
3213 * 16May01: If we're reentered then journal_current_handle() will be
3214 * non-zero. We simply *return*.
3215 *
3216 * 1 July 2001: @@@ FIXME:
3217 * In journalled data mode, a data buffer may be metadata against the
3218 * current transaction. But the same file is part of a shared mapping
3219 * and someone does a writepage() on it.
3220 *
3221 * We will move the buffer onto the async_data list, but *after* it has
3222 * been dirtied. So there's a small window where we have dirty data on
3223 * BJ_Metadata.
3224 *
3225 * Note that this only applies to the last partial page in the file. The
3226 * bit which block_write_full_page() uses prepare/commit for. (That's
3227 * broken code anyway: it's wrong for msync()).
3228 *
3229 * It's a rare case: affects the final partial page, for journalled data
3230 * where the file is subject to bith write() and writepage() in the same
3231 * transction. To fix it we'll need a custom block_write_full_page().
3232 * We'll probably need that anyway for journalling writepage() output.
3233 *
3234 * We don't honour synchronous mounts for writepage(). That would be
3235 * disastrous. Any write() or metadata operation will sync the fs for
3236 * us.
3237 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003238 */
Jan Kara678aaf42008-07-11 19:27:31 -04003239static int __ext4_normal_writepage(struct page *page,
Jan Karacf108bc2008-07-11 19:27:31 -04003240 struct writeback_control *wbc)
3241{
3242 struct inode *inode = page->mapping->host;
3243
3244 if (test_opt(inode->i_sb, NOBH))
Theodore Ts'ob920c752009-05-14 00:54:29 -04003245 return nobh_writepage(page, noalloc_get_block_write, wbc);
Jan Karacf108bc2008-07-11 19:27:31 -04003246 else
Theodore Ts'ob920c752009-05-14 00:54:29 -04003247 return block_write_full_page(page, noalloc_get_block_write,
3248 wbc);
Jan Karacf108bc2008-07-11 19:27:31 -04003249}
3250
Jan Kara678aaf42008-07-11 19:27:31 -04003251static int ext4_normal_writepage(struct page *page,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003252 struct writeback_control *wbc)
3253{
3254 struct inode *inode = page->mapping->host;
Jan Karacf108bc2008-07-11 19:27:31 -04003255 loff_t size = i_size_read(inode);
3256 loff_t len;
3257
Theodore Ts'oba80b102009-01-03 20:03:21 -05003258 trace_mark(ext4_normal_writepage,
3259 "dev %s ino %lu page_index %lu",
3260 inode->i_sb->s_id, inode->i_ino, page->index);
Jan Karacf108bc2008-07-11 19:27:31 -04003261 J_ASSERT(PageLocked(page));
Jan Karacf108bc2008-07-11 19:27:31 -04003262 if (page->index == size >> PAGE_CACHE_SHIFT)
3263 len = size & ~PAGE_CACHE_MASK;
3264 else
3265 len = PAGE_CACHE_SIZE;
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04003266
3267 if (page_has_buffers(page)) {
3268 /* if page has buffers it should all be mapped
3269 * and allocated. If there are not buffers attached
3270 * to the page we know the page is dirty but it lost
3271 * buffers. That means that at some moment in time
3272 * after write_begin() / write_end() has been called
3273 * all buffers have been clean and thus they must have been
3274 * written at least once. So they are all mapped and we can
3275 * happily proceed with mapping them and writing the page.
3276 */
3277 BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
3278 ext4_bh_unmapped_or_delay));
3279 }
Jan Karacf108bc2008-07-11 19:27:31 -04003280
3281 if (!ext4_journal_current_handle())
Jan Kara678aaf42008-07-11 19:27:31 -04003282 return __ext4_normal_writepage(page, wbc);
Jan Karacf108bc2008-07-11 19:27:31 -04003283
3284 redirty_page_for_writepage(wbc, page);
3285 unlock_page(page);
3286 return 0;
3287}
3288
3289static int __ext4_journalled_writepage(struct page *page,
3290 struct writeback_control *wbc)
3291{
3292 struct address_space *mapping = page->mapping;
3293 struct inode *inode = mapping->host;
3294 struct buffer_head *page_bufs;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003295 handle_t *handle = NULL;
3296 int ret = 0;
3297 int err;
3298
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04003299 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
Theodore Ts'ob920c752009-05-14 00:54:29 -04003300 noalloc_get_block_write);
Jan Karacf108bc2008-07-11 19:27:31 -04003301 if (ret != 0)
3302 goto out_unlock;
3303
3304 page_bufs = page_buffers(page);
3305 walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,
3306 bget_one);
3307 /* As soon as we unlock the page, it can go away, but we have
3308 * references to buffers so we are safe */
3309 unlock_page(page);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003310
Mingming Cao617ba132006-10-11 01:20:53 -07003311 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003312 if (IS_ERR(handle)) {
3313 ret = PTR_ERR(handle);
Jan Karacf108bc2008-07-11 19:27:31 -04003314 goto out;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003315 }
3316
Jan Karacf108bc2008-07-11 19:27:31 -04003317 ret = walk_page_buffers(handle, page_bufs, 0,
3318 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003319
Jan Karacf108bc2008-07-11 19:27:31 -04003320 err = walk_page_buffers(handle, page_bufs, 0,
3321 PAGE_CACHE_SIZE, NULL, write_end_fn);
3322 if (ret == 0)
3323 ret = err;
Mingming Cao617ba132006-10-11 01:20:53 -07003324 err = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003325 if (!ret)
3326 ret = err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003327
Jan Karacf108bc2008-07-11 19:27:31 -04003328 walk_page_buffers(handle, page_bufs, 0,
3329 PAGE_CACHE_SIZE, NULL, bput_one);
3330 EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
3331 goto out;
3332
3333out_unlock:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003334 unlock_page(page);
Jan Karacf108bc2008-07-11 19:27:31 -04003335out:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003336 return ret;
3337}
3338
Mingming Cao617ba132006-10-11 01:20:53 -07003339static int ext4_journalled_writepage(struct page *page,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003340 struct writeback_control *wbc)
3341{
3342 struct inode *inode = page->mapping->host;
Jan Karacf108bc2008-07-11 19:27:31 -04003343 loff_t size = i_size_read(inode);
3344 loff_t len;
3345
Theodore Ts'oba80b102009-01-03 20:03:21 -05003346 trace_mark(ext4_journalled_writepage,
3347 "dev %s ino %lu page_index %lu",
3348 inode->i_sb->s_id, inode->i_ino, page->index);
Jan Karacf108bc2008-07-11 19:27:31 -04003349 J_ASSERT(PageLocked(page));
Jan Karacf108bc2008-07-11 19:27:31 -04003350 if (page->index == size >> PAGE_CACHE_SHIFT)
3351 len = size & ~PAGE_CACHE_MASK;
3352 else
3353 len = PAGE_CACHE_SIZE;
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04003354
3355 if (page_has_buffers(page)) {
3356 /* if page has buffers it should all be mapped
3357 * and allocated. If there are not buffers attached
3358 * to the page we know the page is dirty but it lost
3359 * buffers. That means that at some moment in time
3360 * after write_begin() / write_end() has been called
3361 * all buffers have been clean and thus they must have been
3362 * written at least once. So they are all mapped and we can
3363 * happily proceed with mapping them and writing the page.
3364 */
3365 BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
3366 ext4_bh_unmapped_or_delay));
3367 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003368
Mingming Cao617ba132006-10-11 01:20:53 -07003369 if (ext4_journal_current_handle())
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003370 goto no_write;
3371
Jan Karacf108bc2008-07-11 19:27:31 -04003372 if (PageChecked(page)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003373 /*
3374 * It's mmapped pagecache. Add buffers and journal it. There
3375 * doesn't seem much point in redirtying the page here.
3376 */
3377 ClearPageChecked(page);
Jan Karacf108bc2008-07-11 19:27:31 -04003378 return __ext4_journalled_writepage(page, wbc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003379 } else {
3380 /*
3381 * It may be a page full of checkpoint-mode buffers. We don't
3382 * really know unless we go poke around in the buffer_heads.
3383 * But block_write_full_page will do the right thing.
3384 */
Theodore Ts'ob920c752009-05-14 00:54:29 -04003385 return block_write_full_page(page, noalloc_get_block_write,
3386 wbc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003387 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003388no_write:
3389 redirty_page_for_writepage(wbc, page);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003390 unlock_page(page);
Jan Karacf108bc2008-07-11 19:27:31 -04003391 return 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003392}
3393
Mingming Cao617ba132006-10-11 01:20:53 -07003394static int ext4_readpage(struct file *file, struct page *page)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003395{
Mingming Cao617ba132006-10-11 01:20:53 -07003396 return mpage_readpage(page, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003397}
3398
3399static int
Mingming Cao617ba132006-10-11 01:20:53 -07003400ext4_readpages(struct file *file, struct address_space *mapping,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003401 struct list_head *pages, unsigned nr_pages)
3402{
Mingming Cao617ba132006-10-11 01:20:53 -07003403 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003404}
3405
Mingming Cao617ba132006-10-11 01:20:53 -07003406static void ext4_invalidatepage(struct page *page, unsigned long offset)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003407{
Mingming Cao617ba132006-10-11 01:20:53 -07003408 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003409
3410 /*
3411 * If it's a full truncate we just forget about the pending dirtying
3412 */
3413 if (offset == 0)
3414 ClearPageChecked(page);
3415
Frank Mayhar03901312009-01-07 00:06:22 -05003416 if (journal)
3417 jbd2_journal_invalidatepage(journal, page, offset);
3418 else
3419 block_invalidatepage(page, offset);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003420}
3421
Mingming Cao617ba132006-10-11 01:20:53 -07003422static int ext4_releasepage(struct page *page, gfp_t wait)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003423{
Mingming Cao617ba132006-10-11 01:20:53 -07003424 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003425
3426 WARN_ON(PageChecked(page));
3427 if (!page_has_buffers(page))
3428 return 0;
Frank Mayhar03901312009-01-07 00:06:22 -05003429 if (journal)
3430 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3431 else
3432 return try_to_free_buffers(page);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003433}
3434
3435/*
3436 * If the O_DIRECT write will extend the file then add this inode to the
3437 * orphan list. So recovery will truncate it back to the original size
3438 * if the machine crashes during the write.
3439 *
3440 * If the O_DIRECT write is intantiating holes inside i_size and the machine
Jan Kara7fb54092008-02-10 01:08:38 -05003441 * crashes then stale disk data _may_ be exposed inside the file. But current
3442 * VFS code falls back into buffered path in that case so we are safe.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003443 */
Mingming Cao617ba132006-10-11 01:20:53 -07003444static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003445 const struct iovec *iov, loff_t offset,
3446 unsigned long nr_segs)
3447{
3448 struct file *file = iocb->ki_filp;
3449 struct inode *inode = file->f_mapping->host;
Mingming Cao617ba132006-10-11 01:20:53 -07003450 struct ext4_inode_info *ei = EXT4_I(inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003451 handle_t *handle;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003452 ssize_t ret;
3453 int orphan = 0;
3454 size_t count = iov_length(iov, nr_segs);
3455
3456 if (rw == WRITE) {
3457 loff_t final_size = offset + count;
3458
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003459 if (final_size > inode->i_size) {
Jan Kara7fb54092008-02-10 01:08:38 -05003460 /* Credits for sb + inode write */
3461 handle = ext4_journal_start(inode, 2);
3462 if (IS_ERR(handle)) {
3463 ret = PTR_ERR(handle);
3464 goto out;
3465 }
Mingming Cao617ba132006-10-11 01:20:53 -07003466 ret = ext4_orphan_add(handle, inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003467 if (ret) {
3468 ext4_journal_stop(handle);
3469 goto out;
3470 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003471 orphan = 1;
3472 ei->i_disksize = inode->i_size;
Jan Kara7fb54092008-02-10 01:08:38 -05003473 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003474 }
3475 }
3476
3477 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
3478 offset, nr_segs,
Mingming Cao617ba132006-10-11 01:20:53 -07003479 ext4_get_block, NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003480
Jan Kara7fb54092008-02-10 01:08:38 -05003481 if (orphan) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003482 int err;
3483
Jan Kara7fb54092008-02-10 01:08:38 -05003484 /* Credits for sb + inode write */
3485 handle = ext4_journal_start(inode, 2);
3486 if (IS_ERR(handle)) {
3487 /* This is really bad luck. We've written the data
3488 * but cannot extend i_size. Bail out and pretend
3489 * the write failed... */
3490 ret = PTR_ERR(handle);
3491 goto out;
3492 }
3493 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07003494 ext4_orphan_del(handle, inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003495 if (ret > 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003496 loff_t end = offset + ret;
3497 if (end > inode->i_size) {
3498 ei->i_disksize = end;
3499 i_size_write(inode, end);
3500 /*
3501 * We're going to return a positive `ret'
3502 * here due to non-zero-length I/O, so there's
3503 * no way of reporting error returns from
Mingming Cao617ba132006-10-11 01:20:53 -07003504 * ext4_mark_inode_dirty() to userspace. So
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003505 * ignore it.
3506 */
Mingming Cao617ba132006-10-11 01:20:53 -07003507 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003508 }
3509 }
Mingming Cao617ba132006-10-11 01:20:53 -07003510 err = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003511 if (ret == 0)
3512 ret = err;
3513 }
3514out:
3515 return ret;
3516}
3517
3518/*
Mingming Cao617ba132006-10-11 01:20:53 -07003519 * Pages can be marked dirty completely asynchronously from ext4's journalling
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003520 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3521 * much here because ->set_page_dirty is called under VFS locks. The page is
3522 * not necessarily locked.
3523 *
3524 * We cannot just dirty the page and leave attached buffers clean, because the
3525 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3526 * or jbddirty because all the journalling code will explode.
3527 *
3528 * So what we do is to mark the page "pending dirty" and next time writepage
3529 * is called, propagate that into the buffers appropriately.
3530 */
Mingming Cao617ba132006-10-11 01:20:53 -07003531static int ext4_journalled_set_page_dirty(struct page *page)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003532{
3533 SetPageChecked(page);
3534 return __set_page_dirty_nobuffers(page);
3535}
3536
Mingming Cao617ba132006-10-11 01:20:53 -07003537static const struct address_space_operations ext4_ordered_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003538 .readpage = ext4_readpage,
3539 .readpages = ext4_readpages,
3540 .writepage = ext4_normal_writepage,
3541 .sync_page = block_sync_page,
3542 .write_begin = ext4_write_begin,
3543 .write_end = ext4_ordered_write_end,
3544 .bmap = ext4_bmap,
3545 .invalidatepage = ext4_invalidatepage,
3546 .releasepage = ext4_releasepage,
3547 .direct_IO = ext4_direct_IO,
3548 .migratepage = buffer_migrate_page,
3549 .is_partially_uptodate = block_is_partially_uptodate,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003550};
3551
Mingming Cao617ba132006-10-11 01:20:53 -07003552static const struct address_space_operations ext4_writeback_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003553 .readpage = ext4_readpage,
3554 .readpages = ext4_readpages,
3555 .writepage = ext4_normal_writepage,
3556 .sync_page = block_sync_page,
3557 .write_begin = ext4_write_begin,
3558 .write_end = ext4_writeback_write_end,
3559 .bmap = ext4_bmap,
3560 .invalidatepage = ext4_invalidatepage,
3561 .releasepage = ext4_releasepage,
3562 .direct_IO = ext4_direct_IO,
3563 .migratepage = buffer_migrate_page,
3564 .is_partially_uptodate = block_is_partially_uptodate,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003565};
3566
Mingming Cao617ba132006-10-11 01:20:53 -07003567static const struct address_space_operations ext4_journalled_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003568 .readpage = ext4_readpage,
3569 .readpages = ext4_readpages,
3570 .writepage = ext4_journalled_writepage,
3571 .sync_page = block_sync_page,
3572 .write_begin = ext4_write_begin,
3573 .write_end = ext4_journalled_write_end,
3574 .set_page_dirty = ext4_journalled_set_page_dirty,
3575 .bmap = ext4_bmap,
3576 .invalidatepage = ext4_invalidatepage,
3577 .releasepage = ext4_releasepage,
3578 .is_partially_uptodate = block_is_partially_uptodate,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003579};
3580
Alex Tomas64769242008-07-11 19:27:31 -04003581static const struct address_space_operations ext4_da_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003582 .readpage = ext4_readpage,
3583 .readpages = ext4_readpages,
3584 .writepage = ext4_da_writepage,
3585 .writepages = ext4_da_writepages,
3586 .sync_page = block_sync_page,
3587 .write_begin = ext4_da_write_begin,
3588 .write_end = ext4_da_write_end,
3589 .bmap = ext4_bmap,
3590 .invalidatepage = ext4_da_invalidatepage,
3591 .releasepage = ext4_releasepage,
3592 .direct_IO = ext4_direct_IO,
3593 .migratepage = buffer_migrate_page,
3594 .is_partially_uptodate = block_is_partially_uptodate,
Alex Tomas64769242008-07-11 19:27:31 -04003595};
3596
Mingming Cao617ba132006-10-11 01:20:53 -07003597void ext4_set_aops(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003598{
Aneesh Kumar K.Vcd1aac32008-07-11 19:27:31 -04003599 if (ext4_should_order_data(inode) &&
3600 test_opt(inode->i_sb, DELALLOC))
3601 inode->i_mapping->a_ops = &ext4_da_aops;
3602 else if (ext4_should_order_data(inode))
Mingming Cao617ba132006-10-11 01:20:53 -07003603 inode->i_mapping->a_ops = &ext4_ordered_aops;
Alex Tomas64769242008-07-11 19:27:31 -04003604 else if (ext4_should_writeback_data(inode) &&
3605 test_opt(inode->i_sb, DELALLOC))
3606 inode->i_mapping->a_ops = &ext4_da_aops;
Mingming Cao617ba132006-10-11 01:20:53 -07003607 else if (ext4_should_writeback_data(inode))
3608 inode->i_mapping->a_ops = &ext4_writeback_aops;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003609 else
Mingming Cao617ba132006-10-11 01:20:53 -07003610 inode->i_mapping->a_ops = &ext4_journalled_aops;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003611}
3612
3613/*
Mingming Cao617ba132006-10-11 01:20:53 -07003614 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003615 * up to the end of the block which corresponds to `from'.
3616 * This required during truncate. We need to physically zero the tail end
3617 * of that block so it doesn't yield old data if the file is later grown.
3618 */
Jan Karacf108bc2008-07-11 19:27:31 -04003619int ext4_block_truncate_page(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003620 struct address_space *mapping, loff_t from)
3621{
Mingming Cao617ba132006-10-11 01:20:53 -07003622 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003623 unsigned offset = from & (PAGE_CACHE_SIZE-1);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003624 unsigned blocksize, length, pos;
3625 ext4_lblk_t iblock;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003626 struct inode *inode = mapping->host;
3627 struct buffer_head *bh;
Jan Karacf108bc2008-07-11 19:27:31 -04003628 struct page *page;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003629 int err = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003630
Jan Karacf108bc2008-07-11 19:27:31 -04003631 page = grab_cache_page(mapping, from >> PAGE_CACHE_SHIFT);
3632 if (!page)
3633 return -EINVAL;
3634
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003635 blocksize = inode->i_sb->s_blocksize;
3636 length = blocksize - (offset & (blocksize - 1));
3637 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3638
3639 /*
3640 * For "nobh" option, we can only work if we don't need to
3641 * read-in the page - otherwise we create buffers to do the IO.
3642 */
3643 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
Mingming Cao617ba132006-10-11 01:20:53 -07003644 ext4_should_writeback_data(inode) && PageUptodate(page)) {
Christoph Lametereebd2aa2008-02-04 22:28:29 -08003645 zero_user(page, offset, length);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003646 set_page_dirty(page);
3647 goto unlock;
3648 }
3649
3650 if (!page_has_buffers(page))
3651 create_empty_buffers(page, blocksize, 0);
3652
3653 /* Find the buffer that contains "offset" */
3654 bh = page_buffers(page);
3655 pos = blocksize;
3656 while (offset >= pos) {
3657 bh = bh->b_this_page;
3658 iblock++;
3659 pos += blocksize;
3660 }
3661
3662 err = 0;
3663 if (buffer_freed(bh)) {
3664 BUFFER_TRACE(bh, "freed: skip");
3665 goto unlock;
3666 }
3667
3668 if (!buffer_mapped(bh)) {
3669 BUFFER_TRACE(bh, "unmapped");
Mingming Cao617ba132006-10-11 01:20:53 -07003670 ext4_get_block(inode, iblock, bh, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003671 /* unmapped? It's a hole - nothing to do */
3672 if (!buffer_mapped(bh)) {
3673 BUFFER_TRACE(bh, "still unmapped");
3674 goto unlock;
3675 }
3676 }
3677
3678 /* Ok, it's mapped. Make sure it's up-to-date */
3679 if (PageUptodate(page))
3680 set_buffer_uptodate(bh);
3681
3682 if (!buffer_uptodate(bh)) {
3683 err = -EIO;
3684 ll_rw_block(READ, 1, &bh);
3685 wait_on_buffer(bh);
3686 /* Uhhuh. Read error. Complain and punt. */
3687 if (!buffer_uptodate(bh))
3688 goto unlock;
3689 }
3690
Mingming Cao617ba132006-10-11 01:20:53 -07003691 if (ext4_should_journal_data(inode)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003692 BUFFER_TRACE(bh, "get write access");
Mingming Cao617ba132006-10-11 01:20:53 -07003693 err = ext4_journal_get_write_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003694 if (err)
3695 goto unlock;
3696 }
3697
Christoph Lametereebd2aa2008-02-04 22:28:29 -08003698 zero_user(page, offset, length);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003699
3700 BUFFER_TRACE(bh, "zeroed end of block");
3701
3702 err = 0;
Mingming Cao617ba132006-10-11 01:20:53 -07003703 if (ext4_should_journal_data(inode)) {
Frank Mayhar03901312009-01-07 00:06:22 -05003704 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003705 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07003706 if (ext4_should_order_data(inode))
Jan Kara678aaf42008-07-11 19:27:31 -04003707 err = ext4_jbd2_file_inode(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003708 mark_buffer_dirty(bh);
3709 }
3710
3711unlock:
3712 unlock_page(page);
3713 page_cache_release(page);
3714 return err;
3715}
3716
3717/*
3718 * Probably it should be a library function... search for first non-zero word
3719 * or memcmp with zero_page, whatever is better for particular architecture.
3720 * Linus?
3721 */
3722static inline int all_zeroes(__le32 *p, __le32 *q)
3723{
3724 while (p < q)
3725 if (*p++)
3726 return 0;
3727 return 1;
3728}
3729
3730/**
Mingming Cao617ba132006-10-11 01:20:53 -07003731 * ext4_find_shared - find the indirect blocks for partial truncation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003732 * @inode: inode in question
3733 * @depth: depth of the affected branch
Mingming Cao617ba132006-10-11 01:20:53 -07003734 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003735 * @chain: place to store the pointers to partial indirect blocks
3736 * @top: place to the (detached) top of branch
3737 *
Mingming Cao617ba132006-10-11 01:20:53 -07003738 * This is a helper function used by ext4_truncate().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003739 *
3740 * When we do truncate() we may have to clean the ends of several
3741 * indirect blocks but leave the blocks themselves alive. Block is
3742 * partially truncated if some data below the new i_size is refered
3743 * from it (and it is on the path to the first completely truncated
3744 * data block, indeed). We have to free the top of that path along
3745 * with everything to the right of the path. Since no allocation
Mingming Cao617ba132006-10-11 01:20:53 -07003746 * past the truncation point is possible until ext4_truncate()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003747 * finishes, we may safely do the latter, but top of branch may
3748 * require special attention - pageout below the truncation point
3749 * might try to populate it.
3750 *
3751 * We atomically detach the top of branch from the tree, store the
3752 * block number of its root in *@top, pointers to buffer_heads of
3753 * partially truncated blocks - in @chain[].bh and pointers to
3754 * their last elements that should not be removed - in
3755 * @chain[].p. Return value is the pointer to last filled element
3756 * of @chain.
3757 *
3758 * The work left to caller to do the actual freeing of subtrees:
3759 * a) free the subtree starting from *@top
3760 * b) free the subtrees whose roots are stored in
3761 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
3762 * c) free the subtrees growing from the inode past the @chain[0].
3763 * (no partially truncated stuff there). */
3764
Mingming Cao617ba132006-10-11 01:20:53 -07003765static Indirect *ext4_find_shared(struct inode *inode, int depth,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003766 ext4_lblk_t offsets[4], Indirect chain[4], __le32 *top)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003767{
3768 Indirect *partial, *p;
3769 int k, err;
3770
3771 *top = 0;
3772 /* Make k index the deepest non-null offest + 1 */
3773 for (k = depth; k > 1 && !offsets[k-1]; k--)
3774 ;
Mingming Cao617ba132006-10-11 01:20:53 -07003775 partial = ext4_get_branch(inode, k, offsets, chain, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003776 /* Writer: pointers */
3777 if (!partial)
3778 partial = chain + k-1;
3779 /*
3780 * If the branch acquired continuation since we've looked at it -
3781 * fine, it should all survive and (new) top doesn't belong to us.
3782 */
3783 if (!partial->key && *partial->p)
3784 /* Writer: end */
3785 goto no_top;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003786 for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003787 ;
3788 /*
3789 * OK, we've found the last block that must survive. The rest of our
3790 * branch should be detached before unlocking. However, if that rest
3791 * of branch is all ours and does not grow immediately from the inode
3792 * it's easier to cheat and just decrement partial->p.
3793 */
3794 if (p == chain + k - 1 && p > chain) {
3795 p->p--;
3796 } else {
3797 *top = *p->p;
Mingming Cao617ba132006-10-11 01:20:53 -07003798 /* Nope, don't do this in ext4. Must leave the tree intact */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003799#if 0
3800 *p->p = 0;
3801#endif
3802 }
3803 /* Writer: end */
3804
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003805 while (partial > p) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003806 brelse(partial->bh);
3807 partial--;
3808 }
3809no_top:
3810 return partial;
3811}
3812
3813/*
3814 * Zero a number of block pointers in either an inode or an indirect block.
3815 * If we restart the transaction we must again get write access to the
3816 * indirect block for further modification.
3817 *
3818 * We release `count' blocks on disk, but (last - first) may be greater
3819 * than `count' because there can be holes in there.
3820 */
Mingming Cao617ba132006-10-11 01:20:53 -07003821static void ext4_clear_blocks(handle_t *handle, struct inode *inode,
3822 struct buffer_head *bh, ext4_fsblk_t block_to_free,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003823 unsigned long count, __le32 *first, __le32 *last)
3824{
3825 __le32 *p;
3826 if (try_to_extend_transaction(handle, inode)) {
3827 if (bh) {
Frank Mayhar03901312009-01-07 00:06:22 -05003828 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
3829 ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003830 }
Mingming Cao617ba132006-10-11 01:20:53 -07003831 ext4_mark_inode_dirty(handle, inode);
3832 ext4_journal_test_restart(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003833 if (bh) {
3834 BUFFER_TRACE(bh, "retaking write access");
Mingming Cao617ba132006-10-11 01:20:53 -07003835 ext4_journal_get_write_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003836 }
3837 }
3838
3839 /*
3840 * Any buffers which are on the journal will be in memory. We find
Mingming Caodab291a2006-10-11 01:21:01 -07003841 * them on the hash table so jbd2_journal_revoke() will run jbd2_journal_forget()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003842 * on them. We've already detached each block from the file, so
Mingming Caodab291a2006-10-11 01:21:01 -07003843 * bforget() in jbd2_journal_forget() should be safe.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003844 *
Mingming Caodab291a2006-10-11 01:21:01 -07003845 * AKPM: turn on bforget in jbd2_journal_forget()!!!
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003846 */
3847 for (p = first; p < last; p++) {
3848 u32 nr = le32_to_cpu(*p);
3849 if (nr) {
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05003850 struct buffer_head *tbh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003851
3852 *p = 0;
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05003853 tbh = sb_find_get_block(inode->i_sb, nr);
3854 ext4_forget(handle, 0, inode, tbh, nr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003855 }
3856 }
3857
Alex Tomasc9de5602008-01-29 00:19:52 -05003858 ext4_free_blocks(handle, inode, block_to_free, count, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003859}
3860
3861/**
Mingming Cao617ba132006-10-11 01:20:53 -07003862 * ext4_free_data - free a list of data blocks
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003863 * @handle: handle for this transaction
3864 * @inode: inode we are dealing with
3865 * @this_bh: indirect buffer_head which contains *@first and *@last
3866 * @first: array of block numbers
3867 * @last: points immediately past the end of array
3868 *
3869 * We are freeing all blocks refered from that array (numbers are stored as
3870 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
3871 *
3872 * We accumulate contiguous runs of blocks to free. Conveniently, if these
3873 * blocks are contiguous then releasing them at one time will only affect one
3874 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
3875 * actually use a lot of journal space.
3876 *
3877 * @this_bh will be %NULL if @first and @last point into the inode's direct
3878 * block pointers.
3879 */
Mingming Cao617ba132006-10-11 01:20:53 -07003880static void ext4_free_data(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003881 struct buffer_head *this_bh,
3882 __le32 *first, __le32 *last)
3883{
Mingming Cao617ba132006-10-11 01:20:53 -07003884 ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003885 unsigned long count = 0; /* Number of blocks in the run */
3886 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
3887 corresponding to
3888 block_to_free */
Mingming Cao617ba132006-10-11 01:20:53 -07003889 ext4_fsblk_t nr; /* Current block # */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003890 __le32 *p; /* Pointer into inode/ind
3891 for current block */
3892 int err;
3893
3894 if (this_bh) { /* For indirect block */
3895 BUFFER_TRACE(this_bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07003896 err = ext4_journal_get_write_access(handle, this_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003897 /* Important: if we can't update the indirect pointers
3898 * to the blocks, we can't free them. */
3899 if (err)
3900 return;
3901 }
3902
3903 for (p = first; p < last; p++) {
3904 nr = le32_to_cpu(*p);
3905 if (nr) {
3906 /* accumulate blocks to free if they're contiguous */
3907 if (count == 0) {
3908 block_to_free = nr;
3909 block_to_free_p = p;
3910 count = 1;
3911 } else if (nr == block_to_free + count) {
3912 count++;
3913 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07003914 ext4_clear_blocks(handle, inode, this_bh,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003915 block_to_free,
3916 count, block_to_free_p, p);
3917 block_to_free = nr;
3918 block_to_free_p = p;
3919 count = 1;
3920 }
3921 }
3922 }
3923
3924 if (count > 0)
Mingming Cao617ba132006-10-11 01:20:53 -07003925 ext4_clear_blocks(handle, inode, this_bh, block_to_free,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003926 count, block_to_free_p, p);
3927
3928 if (this_bh) {
Frank Mayhar03901312009-01-07 00:06:22 -05003929 BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
Duane Griffin71dc8fb2008-07-11 19:27:31 -04003930
3931 /*
3932 * The buffer head should have an attached journal head at this
3933 * point. However, if the data is corrupted and an indirect
3934 * block pointed to itself, it would have been detached when
3935 * the block was cleared. Check for this instead of OOPSing.
3936 */
Theodore Ts'oe7f07962009-01-20 09:50:19 -05003937 if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
Frank Mayhar03901312009-01-07 00:06:22 -05003938 ext4_handle_dirty_metadata(handle, inode, this_bh);
Duane Griffin71dc8fb2008-07-11 19:27:31 -04003939 else
3940 ext4_error(inode->i_sb, __func__,
3941 "circular indirect block detected, "
3942 "inode=%lu, block=%llu",
3943 inode->i_ino,
3944 (unsigned long long) this_bh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003945 }
3946}
3947
3948/**
Mingming Cao617ba132006-10-11 01:20:53 -07003949 * ext4_free_branches - free an array of branches
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003950 * @handle: JBD handle for this transaction
3951 * @inode: inode we are dealing with
3952 * @parent_bh: the buffer_head which contains *@first and *@last
3953 * @first: array of block numbers
3954 * @last: pointer immediately past the end of array
3955 * @depth: depth of the branches to free
3956 *
3957 * We are freeing all blocks refered from these branches (numbers are
3958 * stored as little-endian 32-bit) and updating @inode->i_blocks
3959 * appropriately.
3960 */
Mingming Cao617ba132006-10-11 01:20:53 -07003961static void ext4_free_branches(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003962 struct buffer_head *parent_bh,
3963 __le32 *first, __le32 *last, int depth)
3964{
Mingming Cao617ba132006-10-11 01:20:53 -07003965 ext4_fsblk_t nr;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003966 __le32 *p;
3967
Frank Mayhar03901312009-01-07 00:06:22 -05003968 if (ext4_handle_is_aborted(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003969 return;
3970
3971 if (depth--) {
3972 struct buffer_head *bh;
Mingming Cao617ba132006-10-11 01:20:53 -07003973 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003974 p = last;
3975 while (--p >= first) {
3976 nr = le32_to_cpu(*p);
3977 if (!nr)
3978 continue; /* A hole */
3979
3980 /* Go read the buffer for the next level down */
3981 bh = sb_bread(inode->i_sb, nr);
3982
3983 /*
3984 * A read failure? Report error and clear slot
3985 * (should be rare).
3986 */
3987 if (!bh) {
Mingming Cao617ba132006-10-11 01:20:53 -07003988 ext4_error(inode->i_sb, "ext4_free_branches",
Mingming Cao2ae02102006-10-11 01:21:11 -07003989 "Read failure, inode=%lu, block=%llu",
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003990 inode->i_ino, nr);
3991 continue;
3992 }
3993
3994 /* This zaps the entire block. Bottom up. */
3995 BUFFER_TRACE(bh, "free child branches");
Mingming Cao617ba132006-10-11 01:20:53 -07003996 ext4_free_branches(handle, inode, bh,
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003997 (__le32 *) bh->b_data,
3998 (__le32 *) bh->b_data + addr_per_block,
3999 depth);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004000
4001 /*
4002 * We've probably journalled the indirect block several
4003 * times during the truncate. But it's no longer
4004 * needed and we now drop it from the transaction via
Mingming Caodab291a2006-10-11 01:21:01 -07004005 * jbd2_journal_revoke().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004006 *
4007 * That's easy if it's exclusively part of this
4008 * transaction. But if it's part of the committing
Mingming Caodab291a2006-10-11 01:21:01 -07004009 * transaction then jbd2_journal_forget() will simply
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004010 * brelse() it. That means that if the underlying
Mingming Cao617ba132006-10-11 01:20:53 -07004011 * block is reallocated in ext4_get_block(),
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004012 * unmap_underlying_metadata() will find this block
4013 * and will try to get rid of it. damn, damn.
4014 *
4015 * If this block has already been committed to the
4016 * journal, a revoke record will be written. And
4017 * revoke records must be emitted *before* clearing
4018 * this block's bit in the bitmaps.
4019 */
Mingming Cao617ba132006-10-11 01:20:53 -07004020 ext4_forget(handle, 1, inode, bh, bh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004021
4022 /*
4023 * Everything below this this pointer has been
4024 * released. Now let this top-of-subtree go.
4025 *
4026 * We want the freeing of this indirect block to be
4027 * atomic in the journal with the updating of the
4028 * bitmap block which owns it. So make some room in
4029 * the journal.
4030 *
4031 * We zero the parent pointer *after* freeing its
4032 * pointee in the bitmaps, so if extend_transaction()
4033 * for some reason fails to put the bitmap changes and
4034 * the release into the same transaction, recovery
4035 * will merely complain about releasing a free block,
4036 * rather than leaking blocks.
4037 */
Frank Mayhar03901312009-01-07 00:06:22 -05004038 if (ext4_handle_is_aborted(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004039 return;
4040 if (try_to_extend_transaction(handle, inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004041 ext4_mark_inode_dirty(handle, inode);
4042 ext4_journal_test_restart(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004043 }
4044
Alex Tomasc9de5602008-01-29 00:19:52 -05004045 ext4_free_blocks(handle, inode, nr, 1, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004046
4047 if (parent_bh) {
4048 /*
4049 * The block which we have just freed is
4050 * pointed to by an indirect block: journal it
4051 */
4052 BUFFER_TRACE(parent_bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07004053 if (!ext4_journal_get_write_access(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004054 parent_bh)){
4055 *p = 0;
4056 BUFFER_TRACE(parent_bh,
Frank Mayhar03901312009-01-07 00:06:22 -05004057 "call ext4_handle_dirty_metadata");
4058 ext4_handle_dirty_metadata(handle,
4059 inode,
4060 parent_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004061 }
4062 }
4063 }
4064 } else {
4065 /* We have reached the bottom of the tree. */
4066 BUFFER_TRACE(parent_bh, "free data blocks");
Mingming Cao617ba132006-10-11 01:20:53 -07004067 ext4_free_data(handle, inode, parent_bh, first, last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004068 }
4069}
4070
Duane Griffin91ef4ca2008-07-11 19:27:31 -04004071int ext4_can_truncate(struct inode *inode)
4072{
4073 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4074 return 0;
4075 if (S_ISREG(inode->i_mode))
4076 return 1;
4077 if (S_ISDIR(inode->i_mode))
4078 return 1;
4079 if (S_ISLNK(inode->i_mode))
4080 return !ext4_inode_is_fast_symlink(inode);
4081 return 0;
4082}
4083
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004084/*
Mingming Cao617ba132006-10-11 01:20:53 -07004085 * ext4_truncate()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004086 *
Mingming Cao617ba132006-10-11 01:20:53 -07004087 * We block out ext4_get_block() block instantiations across the entire
4088 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004089 * simultaneously on behalf of the same inode.
4090 *
4091 * As we work through the truncate and commmit bits of it to the journal there
4092 * is one core, guiding principle: the file's tree must always be consistent on
4093 * disk. We must be able to restart the truncate after a crash.
4094 *
4095 * The file's tree may be transiently inconsistent in memory (although it
4096 * probably isn't), but whenever we close off and commit a journal transaction,
4097 * the contents of (the filesystem + the journal) must be consistent and
4098 * restartable. It's pretty simple, really: bottom up, right to left (although
4099 * left-to-right works OK too).
4100 *
4101 * Note that at recovery time, journal replay occurs *before* the restart of
4102 * truncate against the orphan inode list.
4103 *
4104 * The committed inode has the new, desired i_size (which is the same as
Mingming Cao617ba132006-10-11 01:20:53 -07004105 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004106 * that this inode's truncate did not complete and it will again call
Mingming Cao617ba132006-10-11 01:20:53 -07004107 * ext4_truncate() to have another go. So there will be instantiated blocks
4108 * to the right of the truncation point in a crashed ext4 filesystem. But
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004109 * that's fine - as long as they are linked from the inode, the post-crash
Mingming Cao617ba132006-10-11 01:20:53 -07004110 * ext4_truncate() run will find them and release them.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004111 */
Mingming Cao617ba132006-10-11 01:20:53 -07004112void ext4_truncate(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004113{
4114 handle_t *handle;
Mingming Cao617ba132006-10-11 01:20:53 -07004115 struct ext4_inode_info *ei = EXT4_I(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004116 __le32 *i_data = ei->i_data;
Mingming Cao617ba132006-10-11 01:20:53 -07004117 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004118 struct address_space *mapping = inode->i_mapping;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05004119 ext4_lblk_t offsets[4];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004120 Indirect chain[4];
4121 Indirect *partial;
4122 __le32 nr = 0;
4123 int n;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05004124 ext4_lblk_t last_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004125 unsigned blocksize = inode->i_sb->s_blocksize;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004126
Duane Griffin91ef4ca2008-07-11 19:27:31 -04004127 if (!ext4_can_truncate(inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004128 return;
4129
Theodore Ts'o0eab9282009-06-09 09:54:40 -04004130 if (ei->i_disksize && inode->i_size == 0 &&
4131 !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
Theodore Ts'o7d8f9f72009-02-24 08:21:14 -05004132 ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
4133
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05004134 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
Jan Karacf108bc2008-07-11 19:27:31 -04004135 ext4_ext_truncate(inode);
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05004136 return;
4137 }
Alex Tomasa86c6182006-10-11 01:21:03 -07004138
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004139 handle = start_transaction(inode);
Jan Karacf108bc2008-07-11 19:27:31 -04004140 if (IS_ERR(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004141 return; /* AKPM: return what? */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004142
4143 last_block = (inode->i_size + blocksize-1)
Mingming Cao617ba132006-10-11 01:20:53 -07004144 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004145
Jan Karacf108bc2008-07-11 19:27:31 -04004146 if (inode->i_size & (blocksize - 1))
4147 if (ext4_block_truncate_page(handle, mapping, inode->i_size))
4148 goto out_stop;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004149
Mingming Cao617ba132006-10-11 01:20:53 -07004150 n = ext4_block_to_path(inode, last_block, offsets, NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004151 if (n == 0)
4152 goto out_stop; /* error */
4153
4154 /*
4155 * OK. This truncate is going to happen. We add the inode to the
4156 * orphan list, so that if this truncate spans multiple transactions,
4157 * and we crash, we will resume the truncate when the filesystem
4158 * recovers. It also marks the inode dirty, to catch the new size.
4159 *
4160 * Implication: the file must always be in a sane, consistent
4161 * truncatable state while each transaction commits.
4162 */
Mingming Cao617ba132006-10-11 01:20:53 -07004163 if (ext4_orphan_add(handle, inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004164 goto out_stop;
4165
4166 /*
Mingming Cao632eaea2008-07-11 19:27:31 -04004167 * From here we block out all ext4_get_block() callers who want to
4168 * modify the block allocation tree.
4169 */
4170 down_write(&ei->i_data_sem);
Theodore Ts'ob4df2032008-08-13 21:44:34 -04004171
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04004172 ext4_discard_preallocations(inode);
Theodore Ts'ob4df2032008-08-13 21:44:34 -04004173
Mingming Cao632eaea2008-07-11 19:27:31 -04004174 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004175 * The orphan list entry will now protect us from any crash which
4176 * occurs before the truncate completes, so it is now safe to propagate
4177 * the new, shorter inode size (held for now in i_size) into the
4178 * on-disk inode. We do this via i_disksize, which is the value which
Mingming Cao617ba132006-10-11 01:20:53 -07004179 * ext4 *really* writes onto the disk inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004180 */
4181 ei->i_disksize = inode->i_size;
4182
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004183 if (n == 1) { /* direct blocks */
Mingming Cao617ba132006-10-11 01:20:53 -07004184 ext4_free_data(handle, inode, NULL, i_data+offsets[0],
4185 i_data + EXT4_NDIR_BLOCKS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004186 goto do_indirects;
4187 }
4188
Mingming Cao617ba132006-10-11 01:20:53 -07004189 partial = ext4_find_shared(inode, n, offsets, chain, &nr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004190 /* Kill the top of shared branch (not detached) */
4191 if (nr) {
4192 if (partial == chain) {
4193 /* Shared branch grows from the inode */
Mingming Cao617ba132006-10-11 01:20:53 -07004194 ext4_free_branches(handle, inode, NULL,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004195 &nr, &nr+1, (chain+n-1) - partial);
4196 *partial->p = 0;
4197 /*
4198 * We mark the inode dirty prior to restart,
4199 * and prior to stop. No need for it here.
4200 */
4201 } else {
4202 /* Shared branch grows from an indirect block */
4203 BUFFER_TRACE(partial->bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07004204 ext4_free_branches(handle, inode, partial->bh,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004205 partial->p,
4206 partial->p+1, (chain+n-1) - partial);
4207 }
4208 }
4209 /* Clear the ends of indirect blocks on the shared branch */
4210 while (partial > chain) {
Mingming Cao617ba132006-10-11 01:20:53 -07004211 ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004212 (__le32*)partial->bh->b_data+addr_per_block,
4213 (chain+n-1) - partial);
4214 BUFFER_TRACE(partial->bh, "call brelse");
4215 brelse (partial->bh);
4216 partial--;
4217 }
4218do_indirects:
4219 /* Kill the remaining (whole) subtrees */
4220 switch (offsets[0]) {
4221 default:
Mingming Cao617ba132006-10-11 01:20:53 -07004222 nr = i_data[EXT4_IND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004223 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004224 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
4225 i_data[EXT4_IND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004226 }
Mingming Cao617ba132006-10-11 01:20:53 -07004227 case EXT4_IND_BLOCK:
4228 nr = i_data[EXT4_DIND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004229 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004230 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
4231 i_data[EXT4_DIND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004232 }
Mingming Cao617ba132006-10-11 01:20:53 -07004233 case EXT4_DIND_BLOCK:
4234 nr = i_data[EXT4_TIND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004235 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004236 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
4237 i_data[EXT4_TIND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004238 }
Mingming Cao617ba132006-10-11 01:20:53 -07004239 case EXT4_TIND_BLOCK:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004240 ;
4241 }
4242
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05004243 up_write(&ei->i_data_sem);
Kalpak Shahef7f3832007-07-18 09:15:20 -04004244 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
Mingming Cao617ba132006-10-11 01:20:53 -07004245 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004246
4247 /*
4248 * In a multi-transaction truncate, we only make the final transaction
4249 * synchronous
4250 */
4251 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -05004252 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004253out_stop:
4254 /*
4255 * If this was a simple ftruncate(), and the file will remain alive
4256 * then we need to clear up the orphan record which we created above.
4257 * However, if this was a real unlink then we were called by
Mingming Cao617ba132006-10-11 01:20:53 -07004258 * ext4_delete_inode(), and we allow that function to clean up the
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004259 * orphan info for us.
4260 */
4261 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07004262 ext4_orphan_del(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004263
Mingming Cao617ba132006-10-11 01:20:53 -07004264 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004265}
4266
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004267/*
Mingming Cao617ba132006-10-11 01:20:53 -07004268 * ext4_get_inode_loc returns with an extra refcount against the inode's
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004269 * underlying buffer_head on success. If 'in_mem' is true, we have all
4270 * data in memory that is needed to recreate the on-disk version of this
4271 * inode.
4272 */
Mingming Cao617ba132006-10-11 01:20:53 -07004273static int __ext4_get_inode_loc(struct inode *inode,
4274 struct ext4_iloc *iloc, int in_mem)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004275{
Theodore Ts'o240799c2008-10-09 23:53:47 -04004276 struct ext4_group_desc *gdp;
4277 struct buffer_head *bh;
4278 struct super_block *sb = inode->i_sb;
4279 ext4_fsblk_t block;
4280 int inodes_per_block, inode_offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004281
Aneesh Kumar K.V3a06d772008-11-22 15:04:59 -05004282 iloc->bh = NULL;
Theodore Ts'o240799c2008-10-09 23:53:47 -04004283 if (!ext4_valid_inum(sb, inode->i_ino))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004284 return -EIO;
4285
Theodore Ts'o240799c2008-10-09 23:53:47 -04004286 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
4287 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
4288 if (!gdp)
4289 return -EIO;
4290
4291 /*
4292 * Figure out the offset within the block group inode table
4293 */
4294 inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb));
4295 inode_offset = ((inode->i_ino - 1) %
4296 EXT4_INODES_PER_GROUP(sb));
4297 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
4298 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
4299
4300 bh = sb_getblk(sb, block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004301 if (!bh) {
Theodore Ts'o240799c2008-10-09 23:53:47 -04004302 ext4_error(sb, "ext4_get_inode_loc", "unable to read "
4303 "inode block - inode=%lu, block=%llu",
4304 inode->i_ino, block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004305 return -EIO;
4306 }
4307 if (!buffer_uptodate(bh)) {
4308 lock_buffer(bh);
Hidehiro Kawai9c83a922008-07-26 16:39:26 -04004309
4310 /*
4311 * If the buffer has the write error flag, we have failed
4312 * to write out another inode in the same block. In this
4313 * case, we don't have to read the block because we may
4314 * read the old inode data successfully.
4315 */
4316 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
4317 set_buffer_uptodate(bh);
4318
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004319 if (buffer_uptodate(bh)) {
4320 /* someone brought it uptodate while we waited */
4321 unlock_buffer(bh);
4322 goto has_buffer;
4323 }
4324
4325 /*
4326 * If we have all information of the inode in memory and this
4327 * is the only valid inode in the block, we need not read the
4328 * block.
4329 */
4330 if (in_mem) {
4331 struct buffer_head *bitmap_bh;
Theodore Ts'o240799c2008-10-09 23:53:47 -04004332 int i, start;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004333
Theodore Ts'o240799c2008-10-09 23:53:47 -04004334 start = inode_offset & ~(inodes_per_block - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004335
4336 /* Is the inode bitmap in cache? */
Theodore Ts'o240799c2008-10-09 23:53:47 -04004337 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004338 if (!bitmap_bh)
4339 goto make_io;
4340
4341 /*
4342 * If the inode bitmap isn't in cache then the
4343 * optimisation may end up performing two reads instead
4344 * of one, so skip it.
4345 */
4346 if (!buffer_uptodate(bitmap_bh)) {
4347 brelse(bitmap_bh);
4348 goto make_io;
4349 }
Theodore Ts'o240799c2008-10-09 23:53:47 -04004350 for (i = start; i < start + inodes_per_block; i++) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004351 if (i == inode_offset)
4352 continue;
Mingming Cao617ba132006-10-11 01:20:53 -07004353 if (ext4_test_bit(i, bitmap_bh->b_data))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004354 break;
4355 }
4356 brelse(bitmap_bh);
Theodore Ts'o240799c2008-10-09 23:53:47 -04004357 if (i == start + inodes_per_block) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004358 /* all other inodes are free, so skip I/O */
4359 memset(bh->b_data, 0, bh->b_size);
4360 set_buffer_uptodate(bh);
4361 unlock_buffer(bh);
4362 goto has_buffer;
4363 }
4364 }
4365
4366make_io:
4367 /*
Theodore Ts'o240799c2008-10-09 23:53:47 -04004368 * If we need to do any I/O, try to pre-readahead extra
4369 * blocks from the inode table.
4370 */
4371 if (EXT4_SB(sb)->s_inode_readahead_blks) {
4372 ext4_fsblk_t b, end, table;
4373 unsigned num;
4374
4375 table = ext4_inode_table(sb, gdp);
Theodore Ts'ob713a5e2009-03-31 09:11:14 -04004376 /* s_inode_readahead_blks is always a power of 2 */
Theodore Ts'o240799c2008-10-09 23:53:47 -04004377 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
4378 if (table > b)
4379 b = table;
4380 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
4381 num = EXT4_INODES_PER_GROUP(sb);
4382 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4383 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
Aneesh Kumar K.V560671a2009-01-05 22:20:24 -05004384 num -= ext4_itable_unused_count(sb, gdp);
Theodore Ts'o240799c2008-10-09 23:53:47 -04004385 table += num / inodes_per_block;
4386 if (end > table)
4387 end = table;
4388 while (b <= end)
4389 sb_breadahead(sb, b++);
4390 }
4391
4392 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004393 * There are other valid inodes in the buffer, this inode
4394 * has in-inode xattrs, or we don't have this inode in memory.
4395 * Read the block from disk.
4396 */
4397 get_bh(bh);
4398 bh->b_end_io = end_buffer_read_sync;
4399 submit_bh(READ_META, bh);
4400 wait_on_buffer(bh);
4401 if (!buffer_uptodate(bh)) {
Theodore Ts'o240799c2008-10-09 23:53:47 -04004402 ext4_error(sb, __func__,
4403 "unable to read inode block - inode=%lu, "
4404 "block=%llu", inode->i_ino, block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004405 brelse(bh);
4406 return -EIO;
4407 }
4408 }
4409has_buffer:
4410 iloc->bh = bh;
4411 return 0;
4412}
4413
Mingming Cao617ba132006-10-11 01:20:53 -07004414int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004415{
4416 /* We have all inode data except xattrs in memory here. */
Mingming Cao617ba132006-10-11 01:20:53 -07004417 return __ext4_get_inode_loc(inode, iloc,
4418 !(EXT4_I(inode)->i_state & EXT4_STATE_XATTR));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004419}
4420
Mingming Cao617ba132006-10-11 01:20:53 -07004421void ext4_set_inode_flags(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004422{
Mingming Cao617ba132006-10-11 01:20:53 -07004423 unsigned int flags = EXT4_I(inode)->i_flags;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004424
4425 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
Mingming Cao617ba132006-10-11 01:20:53 -07004426 if (flags & EXT4_SYNC_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004427 inode->i_flags |= S_SYNC;
Mingming Cao617ba132006-10-11 01:20:53 -07004428 if (flags & EXT4_APPEND_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004429 inode->i_flags |= S_APPEND;
Mingming Cao617ba132006-10-11 01:20:53 -07004430 if (flags & EXT4_IMMUTABLE_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004431 inode->i_flags |= S_IMMUTABLE;
Mingming Cao617ba132006-10-11 01:20:53 -07004432 if (flags & EXT4_NOATIME_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004433 inode->i_flags |= S_NOATIME;
Mingming Cao617ba132006-10-11 01:20:53 -07004434 if (flags & EXT4_DIRSYNC_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004435 inode->i_flags |= S_DIRSYNC;
4436}
4437
Jan Karaff9ddf72007-07-18 09:24:20 -04004438/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4439void ext4_get_inode_flags(struct ext4_inode_info *ei)
4440{
4441 unsigned int flags = ei->vfs_inode.i_flags;
4442
4443 ei->i_flags &= ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
4444 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|EXT4_DIRSYNC_FL);
4445 if (flags & S_SYNC)
4446 ei->i_flags |= EXT4_SYNC_FL;
4447 if (flags & S_APPEND)
4448 ei->i_flags |= EXT4_APPEND_FL;
4449 if (flags & S_IMMUTABLE)
4450 ei->i_flags |= EXT4_IMMUTABLE_FL;
4451 if (flags & S_NOATIME)
4452 ei->i_flags |= EXT4_NOATIME_FL;
4453 if (flags & S_DIRSYNC)
4454 ei->i_flags |= EXT4_DIRSYNC_FL;
4455}
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004456static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
4457 struct ext4_inode_info *ei)
4458{
4459 blkcnt_t i_blocks ;
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004460 struct inode *inode = &(ei->vfs_inode);
4461 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004462
4463 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4464 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
4465 /* we are using combined 48 bit field */
4466 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
4467 le32_to_cpu(raw_inode->i_blocks_lo);
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004468 if (ei->i_flags & EXT4_HUGE_FILE_FL) {
4469 /* i_blocks represent file system block size */
4470 return i_blocks << (inode->i_blkbits - 9);
4471 } else {
4472 return i_blocks;
4473 }
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004474 } else {
4475 return le32_to_cpu(raw_inode->i_blocks_lo);
4476 }
4477}
Jan Karaff9ddf72007-07-18 09:24:20 -04004478
David Howells1d1fe1e2008-02-07 00:15:37 -08004479struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004480{
Mingming Cao617ba132006-10-11 01:20:53 -07004481 struct ext4_iloc iloc;
4482 struct ext4_inode *raw_inode;
David Howells1d1fe1e2008-02-07 00:15:37 -08004483 struct ext4_inode_info *ei;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004484 struct buffer_head *bh;
David Howells1d1fe1e2008-02-07 00:15:37 -08004485 struct inode *inode;
4486 long ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004487 int block;
4488
David Howells1d1fe1e2008-02-07 00:15:37 -08004489 inode = iget_locked(sb, ino);
4490 if (!inode)
4491 return ERR_PTR(-ENOMEM);
4492 if (!(inode->i_state & I_NEW))
4493 return inode;
4494
4495 ei = EXT4_I(inode);
Theodore Ts'o03010a32008-10-10 20:02:48 -04004496#ifdef CONFIG_EXT4_FS_POSIX_ACL
Mingming Cao617ba132006-10-11 01:20:53 -07004497 ei->i_acl = EXT4_ACL_NOT_CACHED;
4498 ei->i_default_acl = EXT4_ACL_NOT_CACHED;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004499#endif
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004500
David Howells1d1fe1e2008-02-07 00:15:37 -08004501 ret = __ext4_get_inode_loc(inode, &iloc, 0);
4502 if (ret < 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004503 goto bad_inode;
4504 bh = iloc.bh;
Mingming Cao617ba132006-10-11 01:20:53 -07004505 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004506 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4507 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4508 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004509 if (!(test_opt(inode->i_sb, NO_UID32))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004510 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4511 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4512 }
4513 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004514
4515 ei->i_state = 0;
4516 ei->i_dir_start_lookup = 0;
4517 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4518 /* We now have enough fields to check if the inode was active or not.
4519 * This is needed because nfsd might try to access dead inodes
4520 * the test is that same one that e2fsck uses
4521 * NeilBrown 1999oct15
4522 */
4523 if (inode->i_nlink == 0) {
4524 if (inode->i_mode == 0 ||
Mingming Cao617ba132006-10-11 01:20:53 -07004525 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004526 /* this inode is deleted */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004527 brelse(bh);
David Howells1d1fe1e2008-02-07 00:15:37 -08004528 ret = -ESTALE;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004529 goto bad_inode;
4530 }
4531 /* The only unlinked inodes we let through here have
4532 * valid i_mode and are being read by the orphan
4533 * recovery code: that's fine, we're about to complete
4534 * the process of deleting those. */
4535 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004536 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004537 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
Aneesh Kumar K.V7973c0c2008-01-28 23:58:27 -05004538 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
Theodore Ts'oa9e81742009-04-24 16:11:18 -04004539 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
Badari Pulavartya1ddeb72006-10-11 01:21:09 -07004540 ei->i_file_acl |=
4541 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004542 inode->i_size = ext4_isize(raw_inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004543 ei->i_disksize = inode->i_size;
4544 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4545 ei->i_block_group = iloc.block_group;
Theodore Ts'oa4912122009-03-12 12:18:34 -04004546 ei->i_last_alloc_group = ~0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004547 /*
4548 * NOTE! The in-memory inode i_data array is in little-endian order
4549 * even on big-endian machines: we do NOT byteswap the block numbers!
4550 */
Mingming Cao617ba132006-10-11 01:20:53 -07004551 for (block = 0; block < EXT4_N_BLOCKS; block++)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004552 ei->i_data[block] = raw_inode->i_block[block];
4553 INIT_LIST_HEAD(&ei->i_orphan);
4554
Eric Sandeen0040d982008-02-05 22:36:43 -05004555 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004556 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
Mingming Cao617ba132006-10-11 01:20:53 -07004557 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
Kirill Korotaeve5d28612007-06-23 17:16:51 -07004558 EXT4_INODE_SIZE(inode->i_sb)) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004559 brelse(bh);
David Howells1d1fe1e2008-02-07 00:15:37 -08004560 ret = -EIO;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004561 goto bad_inode;
Kirill Korotaeve5d28612007-06-23 17:16:51 -07004562 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004563 if (ei->i_extra_isize == 0) {
4564 /* The extra space is currently unused. Use it. */
Mingming Cao617ba132006-10-11 01:20:53 -07004565 ei->i_extra_isize = sizeof(struct ext4_inode) -
4566 EXT4_GOOD_OLD_INODE_SIZE;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004567 } else {
4568 __le32 *magic = (void *)raw_inode +
Mingming Cao617ba132006-10-11 01:20:53 -07004569 EXT4_GOOD_OLD_INODE_SIZE +
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004570 ei->i_extra_isize;
Mingming Cao617ba132006-10-11 01:20:53 -07004571 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
4572 ei->i_state |= EXT4_STATE_XATTR;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004573 }
4574 } else
4575 ei->i_extra_isize = 0;
4576
Kalpak Shahef7f3832007-07-18 09:15:20 -04004577 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
4578 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
4579 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
4580 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4581
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004582 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
4583 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4584 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4585 inode->i_version |=
4586 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4587 }
4588
Theodore Ts'oc4b5a612009-04-24 18:45:35 -04004589 ret = 0;
Theodore Ts'o485c26e2009-04-24 13:43:20 -04004590 if (ei->i_file_acl &&
4591 ((ei->i_file_acl <
4592 (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
4593 EXT4_SB(sb)->s_gdb_count)) ||
4594 (ei->i_file_acl >= ext4_blocks_count(EXT4_SB(sb)->s_es)))) {
4595 ext4_error(sb, __func__,
4596 "bad extended attribute block %llu in inode #%lu",
4597 ei->i_file_acl, inode->i_ino);
4598 ret = -EIO;
4599 goto bad_inode;
4600 } else if (ei->i_flags & EXT4_EXTENTS_FL) {
Theodore Ts'oc4b5a612009-04-24 18:45:35 -04004601 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4602 (S_ISLNK(inode->i_mode) &&
4603 !ext4_inode_is_fast_symlink(inode)))
4604 /* Validate extent which is part of inode */
4605 ret = ext4_ext_check_inode(inode);
Thiemo Nagelfe2c8192009-03-31 08:36:10 -04004606 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4607 (S_ISLNK(inode->i_mode) &&
4608 !ext4_inode_is_fast_symlink(inode))) {
4609 /* Validate block references which are part of inode */
4610 ret = ext4_check_inode_blockref(inode);
4611 }
4612 if (ret) {
4613 brelse(bh);
4614 goto bad_inode;
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -04004615 }
4616
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004617 if (S_ISREG(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004618 inode->i_op = &ext4_file_inode_operations;
4619 inode->i_fop = &ext4_file_operations;
4620 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004621 } else if (S_ISDIR(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004622 inode->i_op = &ext4_dir_inode_operations;
4623 inode->i_fop = &ext4_dir_operations;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004624 } else if (S_ISLNK(inode->i_mode)) {
Duane Griffine83c1392008-12-19 20:47:15 +00004625 if (ext4_inode_is_fast_symlink(inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004626 inode->i_op = &ext4_fast_symlink_inode_operations;
Duane Griffine83c1392008-12-19 20:47:15 +00004627 nd_terminate_link(ei->i_data, inode->i_size,
4628 sizeof(ei->i_data) - 1);
4629 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07004630 inode->i_op = &ext4_symlink_inode_operations;
4631 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004632 }
Theodore Ts'o563bdd62009-03-26 00:06:19 -04004633 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
4634 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004635 inode->i_op = &ext4_special_inode_operations;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004636 if (raw_inode->i_block[0])
4637 init_special_inode(inode, inode->i_mode,
4638 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
4639 else
4640 init_special_inode(inode, inode->i_mode,
4641 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
Theodore Ts'o563bdd62009-03-26 00:06:19 -04004642 } else {
4643 brelse(bh);
4644 ret = -EIO;
4645 ext4_error(inode->i_sb, __func__,
4646 "bogus i_mode (%o) for inode=%lu",
4647 inode->i_mode, inode->i_ino);
4648 goto bad_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004649 }
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004650 brelse(iloc.bh);
Mingming Cao617ba132006-10-11 01:20:53 -07004651 ext4_set_inode_flags(inode);
David Howells1d1fe1e2008-02-07 00:15:37 -08004652 unlock_new_inode(inode);
4653 return inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004654
4655bad_inode:
David Howells1d1fe1e2008-02-07 00:15:37 -08004656 iget_failed(inode);
4657 return ERR_PTR(ret);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004658}
4659
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004660static int ext4_inode_blocks_set(handle_t *handle,
4661 struct ext4_inode *raw_inode,
4662 struct ext4_inode_info *ei)
4663{
4664 struct inode *inode = &(ei->vfs_inode);
4665 u64 i_blocks = inode->i_blocks;
4666 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004667
4668 if (i_blocks <= ~0U) {
4669 /*
4670 * i_blocks can be represnted in a 32 bit variable
4671 * as multiple of 512 bytes
4672 */
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004673 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004674 raw_inode->i_blocks_high = 0;
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004675 ei->i_flags &= ~EXT4_HUGE_FILE_FL;
Theodore Ts'of287a1a2008-10-16 22:50:48 -04004676 return 0;
4677 }
4678 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
4679 return -EFBIG;
4680
4681 if (i_blocks <= 0xffffffffffffULL) {
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004682 /*
4683 * i_blocks can be represented in a 48 bit variable
4684 * as multiple of 512 bytes
4685 */
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004686 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004687 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004688 ei->i_flags &= ~EXT4_HUGE_FILE_FL;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004689 } else {
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004690 ei->i_flags |= EXT4_HUGE_FILE_FL;
4691 /* i_block is stored in file system block size */
4692 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4693 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4694 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004695 }
Theodore Ts'of287a1a2008-10-16 22:50:48 -04004696 return 0;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004697}
4698
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004699/*
4700 * Post the struct inode info into an on-disk inode location in the
4701 * buffer-cache. This gobbles the caller's reference to the
4702 * buffer_head in the inode location struct.
4703 *
4704 * The caller must have write access to iloc->bh.
4705 */
Mingming Cao617ba132006-10-11 01:20:53 -07004706static int ext4_do_update_inode(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004707 struct inode *inode,
Mingming Cao617ba132006-10-11 01:20:53 -07004708 struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004709{
Mingming Cao617ba132006-10-11 01:20:53 -07004710 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4711 struct ext4_inode_info *ei = EXT4_I(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004712 struct buffer_head *bh = iloc->bh;
4713 int err = 0, rc, block;
4714
4715 /* For fields not not tracking in the in-memory inode,
4716 * initialise them to zero for new inodes. */
Mingming Cao617ba132006-10-11 01:20:53 -07004717 if (ei->i_state & EXT4_STATE_NEW)
4718 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004719
Jan Karaff9ddf72007-07-18 09:24:20 -04004720 ext4_get_inode_flags(ei);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004721 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004722 if (!(test_opt(inode->i_sb, NO_UID32))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004723 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
4724 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
4725/*
4726 * Fix up interoperability with old kernels. Otherwise, old inodes get
4727 * re-used with the upper 16 bits of the uid/gid intact
4728 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004729 if (!ei->i_dtime) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004730 raw_inode->i_uid_high =
4731 cpu_to_le16(high_16_bits(inode->i_uid));
4732 raw_inode->i_gid_high =
4733 cpu_to_le16(high_16_bits(inode->i_gid));
4734 } else {
4735 raw_inode->i_uid_high = 0;
4736 raw_inode->i_gid_high = 0;
4737 }
4738 } else {
4739 raw_inode->i_uid_low =
4740 cpu_to_le16(fs_high2lowuid(inode->i_uid));
4741 raw_inode->i_gid_low =
4742 cpu_to_le16(fs_high2lowgid(inode->i_gid));
4743 raw_inode->i_uid_high = 0;
4744 raw_inode->i_gid_high = 0;
4745 }
4746 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
Kalpak Shahef7f3832007-07-18 09:15:20 -04004747
4748 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4749 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4750 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4751 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4752
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004753 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4754 goto out_brelse;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004755 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
Aneesh Kumar K.V267e4db2008-04-29 08:11:12 -04004756 /* clear the migrate flag in the raw_inode */
4757 raw_inode->i_flags = cpu_to_le32(ei->i_flags & ~EXT4_EXT_MIGRATE);
Mingming Cao9b8f1f02006-10-11 01:21:13 -07004758 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
4759 cpu_to_le32(EXT4_OS_HURD))
Badari Pulavartya1ddeb72006-10-11 01:21:09 -07004760 raw_inode->i_file_acl_high =
4761 cpu_to_le16(ei->i_file_acl >> 32);
Aneesh Kumar K.V7973c0c2008-01-28 23:58:27 -05004762 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004763 ext4_isize_set(raw_inode, ei->i_disksize);
4764 if (ei->i_disksize > 0x7fffffffULL) {
4765 struct super_block *sb = inode->i_sb;
4766 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4767 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4768 EXT4_SB(sb)->s_es->s_rev_level ==
4769 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4770 /* If this is the first large file
4771 * created, add a flag to the superblock.
4772 */
4773 err = ext4_journal_get_write_access(handle,
4774 EXT4_SB(sb)->s_sbh);
4775 if (err)
4776 goto out_brelse;
4777 ext4_update_dynamic_rev(sb);
4778 EXT4_SET_RO_COMPAT_FEATURE(sb,
Mingming Cao617ba132006-10-11 01:20:53 -07004779 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004780 sb->s_dirt = 1;
Frank Mayhar03901312009-01-07 00:06:22 -05004781 ext4_handle_sync(handle);
4782 err = ext4_handle_dirty_metadata(handle, inode,
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004783 EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004784 }
4785 }
4786 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4787 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4788 if (old_valid_dev(inode->i_rdev)) {
4789 raw_inode->i_block[0] =
4790 cpu_to_le32(old_encode_dev(inode->i_rdev));
4791 raw_inode->i_block[1] = 0;
4792 } else {
4793 raw_inode->i_block[0] = 0;
4794 raw_inode->i_block[1] =
4795 cpu_to_le32(new_encode_dev(inode->i_rdev));
4796 raw_inode->i_block[2] = 0;
4797 }
Mingming Cao617ba132006-10-11 01:20:53 -07004798 } else for (block = 0; block < EXT4_N_BLOCKS; block++)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004799 raw_inode->i_block[block] = ei->i_data[block];
4800
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004801 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4802 if (ei->i_extra_isize) {
4803 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4804 raw_inode->i_version_hi =
4805 cpu_to_le32(inode->i_version >> 32);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004806 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004807 }
4808
Frank Mayhar03901312009-01-07 00:06:22 -05004809 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4810 rc = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004811 if (!err)
4812 err = rc;
Mingming Cao617ba132006-10-11 01:20:53 -07004813 ei->i_state &= ~EXT4_STATE_NEW;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004814
4815out_brelse:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004816 brelse(bh);
Mingming Cao617ba132006-10-11 01:20:53 -07004817 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004818 return err;
4819}
4820
4821/*
Mingming Cao617ba132006-10-11 01:20:53 -07004822 * ext4_write_inode()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004823 *
4824 * We are called from a few places:
4825 *
4826 * - Within generic_file_write() for O_SYNC files.
4827 * Here, there will be no transaction running. We wait for any running
4828 * trasnaction to commit.
4829 *
4830 * - Within sys_sync(), kupdate and such.
4831 * We wait on commit, if tol to.
4832 *
4833 * - Within prune_icache() (PF_MEMALLOC == true)
4834 * Here we simply return. We can't afford to block kswapd on the
4835 * journal commit.
4836 *
4837 * In all cases it is actually safe for us to return without doing anything,
4838 * because the inode has been copied into a raw inode buffer in
Mingming Cao617ba132006-10-11 01:20:53 -07004839 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004840 * knfsd.
4841 *
4842 * Note that we are absolutely dependent upon all inode dirtiers doing the
4843 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4844 * which we are interested.
4845 *
4846 * It would be a bug for them to not do this. The code:
4847 *
4848 * mark_inode_dirty(inode)
4849 * stuff();
4850 * inode->i_size = expr;
4851 *
4852 * is in error because a kswapd-driven write_inode() could occur while
4853 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4854 * will no longer be on the superblock's dirty inode list.
4855 */
Mingming Cao617ba132006-10-11 01:20:53 -07004856int ext4_write_inode(struct inode *inode, int wait)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004857{
4858 if (current->flags & PF_MEMALLOC)
4859 return 0;
4860
Mingming Cao617ba132006-10-11 01:20:53 -07004861 if (ext4_journal_current_handle()) {
Mingming Caob38bd332007-07-19 01:48:35 -07004862 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004863 dump_stack();
4864 return -EIO;
4865 }
4866
4867 if (!wait)
4868 return 0;
4869
Mingming Cao617ba132006-10-11 01:20:53 -07004870 return ext4_force_commit(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004871}
4872
4873/*
Mingming Cao617ba132006-10-11 01:20:53 -07004874 * ext4_setattr()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004875 *
4876 * Called from notify_change.
4877 *
4878 * We want to trap VFS attempts to truncate the file as soon as
4879 * possible. In particular, we want to make sure that when the VFS
4880 * shrinks i_size, we put the inode on the orphan list and modify
4881 * i_disksize immediately, so that during the subsequent flushing of
4882 * dirty pages and freeing of disk blocks, we can guarantee that any
4883 * commit will leave the blocks being flushed in an unused state on
4884 * disk. (On recovery, the inode will get truncated and the blocks will
4885 * be freed, so we have a strong guarantee that no future commit will
4886 * leave these blocks visible to the user.)
4887 *
Jan Kara678aaf42008-07-11 19:27:31 -04004888 * Another thing we have to assure is that if we are in ordered mode
4889 * and inode is still attached to the committing transaction, we must
4890 * we start writeout of all the dirty pages which are being truncated.
4891 * This way we are sure that all the data written in the previous
4892 * transaction are already on disk (truncate waits for pages under
4893 * writeback).
4894 *
4895 * Called with inode->i_mutex down.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004896 */
Mingming Cao617ba132006-10-11 01:20:53 -07004897int ext4_setattr(struct dentry *dentry, struct iattr *attr)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004898{
4899 struct inode *inode = dentry->d_inode;
4900 int error, rc = 0;
4901 const unsigned int ia_valid = attr->ia_valid;
4902
4903 error = inode_change_ok(inode, attr);
4904 if (error)
4905 return error;
4906
4907 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
4908 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
4909 handle_t *handle;
4910
4911 /* (user+group)*(old+new) structure, inode write (sb,
4912 * inode block, ? - but truncate inode update has it) */
Mingming Cao617ba132006-10-11 01:20:53 -07004913 handle = ext4_journal_start(inode, 2*(EXT4_QUOTA_INIT_BLOCKS(inode->i_sb)+
4914 EXT4_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004915 if (IS_ERR(handle)) {
4916 error = PTR_ERR(handle);
4917 goto err_out;
4918 }
Jan Karaa269eb12009-01-26 17:04:39 +01004919 error = vfs_dq_transfer(inode, attr) ? -EDQUOT : 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004920 if (error) {
Mingming Cao617ba132006-10-11 01:20:53 -07004921 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004922 return error;
4923 }
4924 /* Update corresponding info in inode so that everything is in
4925 * one transaction */
4926 if (attr->ia_valid & ATTR_UID)
4927 inode->i_uid = attr->ia_uid;
4928 if (attr->ia_valid & ATTR_GID)
4929 inode->i_gid = attr->ia_gid;
Mingming Cao617ba132006-10-11 01:20:53 -07004930 error = ext4_mark_inode_dirty(handle, inode);
4931 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004932 }
4933
Eric Sandeene2b46572008-01-28 23:58:27 -05004934 if (attr->ia_valid & ATTR_SIZE) {
4935 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
4936 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4937
4938 if (attr->ia_size > sbi->s_bitmap_maxbytes) {
4939 error = -EFBIG;
4940 goto err_out;
4941 }
4942 }
4943 }
4944
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004945 if (S_ISREG(inode->i_mode) &&
4946 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
4947 handle_t *handle;
4948
Mingming Cao617ba132006-10-11 01:20:53 -07004949 handle = ext4_journal_start(inode, 3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004950 if (IS_ERR(handle)) {
4951 error = PTR_ERR(handle);
4952 goto err_out;
4953 }
4954
Mingming Cao617ba132006-10-11 01:20:53 -07004955 error = ext4_orphan_add(handle, inode);
4956 EXT4_I(inode)->i_disksize = attr->ia_size;
4957 rc = ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004958 if (!error)
4959 error = rc;
Mingming Cao617ba132006-10-11 01:20:53 -07004960 ext4_journal_stop(handle);
Jan Kara678aaf42008-07-11 19:27:31 -04004961
4962 if (ext4_should_order_data(inode)) {
4963 error = ext4_begin_ordered_truncate(inode,
4964 attr->ia_size);
4965 if (error) {
4966 /* Do as much error cleanup as possible */
4967 handle = ext4_journal_start(inode, 3);
4968 if (IS_ERR(handle)) {
4969 ext4_orphan_del(NULL, inode);
4970 goto err_out;
4971 }
4972 ext4_orphan_del(handle, inode);
4973 ext4_journal_stop(handle);
4974 goto err_out;
4975 }
4976 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004977 }
4978
4979 rc = inode_setattr(inode, attr);
4980
Mingming Cao617ba132006-10-11 01:20:53 -07004981 /* If inode_setattr's call to ext4_truncate failed to get a
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004982 * transaction handle at all, we need to clean up the in-core
4983 * orphan list manually. */
4984 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07004985 ext4_orphan_del(NULL, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004986
4987 if (!rc && (ia_valid & ATTR_MODE))
Mingming Cao617ba132006-10-11 01:20:53 -07004988 rc = ext4_acl_chmod(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004989
4990err_out:
Mingming Cao617ba132006-10-11 01:20:53 -07004991 ext4_std_error(inode->i_sb, error);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004992 if (!error)
4993 error = rc;
4994 return error;
4995}
4996
Mingming Cao3e3398a2008-07-11 19:27:31 -04004997int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4998 struct kstat *stat)
4999{
5000 struct inode *inode;
5001 unsigned long delalloc_blocks;
5002
5003 inode = dentry->d_inode;
5004 generic_fillattr(inode, stat);
5005
5006 /*
5007 * We can't update i_blocks if the block allocation is delayed
5008 * otherwise in the case of system crash before the real block
5009 * allocation is done, we will have i_blocks inconsistent with
5010 * on-disk file blocks.
5011 * We always keep i_blocks updated together with real
5012 * allocation. But to not confuse with user, stat
5013 * will return the blocks that include the delayed allocation
5014 * blocks for this file.
5015 */
5016 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
5017 delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
5018 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
5019
5020 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
5021 return 0;
5022}
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005023
Mingming Caoa02908f2008-08-19 22:16:07 -04005024static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
5025 int chunk)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005026{
Mingming Caoa02908f2008-08-19 22:16:07 -04005027 int indirects;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005028
Mingming Caoa02908f2008-08-19 22:16:07 -04005029 /* if nrblocks are contiguous */
5030 if (chunk) {
5031 /*
5032 * With N contiguous data blocks, it need at most
5033 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5034 * 2 dindirect blocks
5035 * 1 tindirect block
5036 */
5037 indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
5038 return indirects + 3;
5039 }
5040 /*
5041 * if nrblocks are not contiguous, worse case, each block touch
5042 * a indirect block, and each indirect block touch a double indirect
5043 * block, plus a triple indirect block
5044 */
5045 indirects = nrblocks * 2 + 1;
5046 return indirects;
5047}
Alex Tomasa86c6182006-10-11 01:21:03 -07005048
Mingming Caoa02908f2008-08-19 22:16:07 -04005049static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
5050{
5051 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
Theodore Ts'oac51d832008-11-06 16:49:36 -05005052 return ext4_indirect_trans_blocks(inode, nrblocks, chunk);
5053 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
Mingming Caoa02908f2008-08-19 22:16:07 -04005054}
Theodore Ts'oac51d832008-11-06 16:49:36 -05005055
Mingming Caoa02908f2008-08-19 22:16:07 -04005056/*
5057 * Account for index blocks, block groups bitmaps and block group
5058 * descriptor blocks if modify datablocks and index blocks
5059 * worse case, the indexs blocks spread over different block groups
5060 *
5061 * If datablocks are discontiguous, they are possible to spread over
5062 * different block groups too. If they are contiugous, with flexbg,
5063 * they could still across block group boundary.
5064 *
5065 * Also account for superblock, inode, quota and xattr blocks
5066 */
5067int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
5068{
Theodore Ts'o8df96752009-05-01 08:50:38 -04005069 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
5070 int gdpblocks;
Mingming Caoa02908f2008-08-19 22:16:07 -04005071 int idxblocks;
5072 int ret = 0;
5073
5074 /*
5075 * How many index blocks need to touch to modify nrblocks?
5076 * The "Chunk" flag indicating whether the nrblocks is
5077 * physically contiguous on disk
5078 *
5079 * For Direct IO and fallocate, they calls get_block to allocate
5080 * one single extent at a time, so they could set the "Chunk" flag
5081 */
5082 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
5083
5084 ret = idxblocks;
5085
5086 /*
5087 * Now let's see how many group bitmaps and group descriptors need
5088 * to account
5089 */
5090 groups = idxblocks;
5091 if (chunk)
5092 groups += 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005093 else
Mingming Caoa02908f2008-08-19 22:16:07 -04005094 groups += nrblocks;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005095
Mingming Caoa02908f2008-08-19 22:16:07 -04005096 gdpblocks = groups;
Theodore Ts'o8df96752009-05-01 08:50:38 -04005097 if (groups > ngroups)
5098 groups = ngroups;
Mingming Caoa02908f2008-08-19 22:16:07 -04005099 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
5100 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
5101
5102 /* bitmaps and block group descriptor blocks */
5103 ret += groups + gdpblocks;
5104
5105 /* Blocks for super block, inode, quota and xattr blocks */
5106 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005107
5108 return ret;
5109}
5110
5111/*
Mingming Caoa02908f2008-08-19 22:16:07 -04005112 * Calulate the total number of credits to reserve to fit
Mingming Caof3bd1f32008-08-19 22:16:03 -04005113 * the modification of a single pages into a single transaction,
5114 * which may include multiple chunks of block allocations.
Mingming Caoa02908f2008-08-19 22:16:07 -04005115 *
Mingming Cao525f4ed2008-08-19 22:15:58 -04005116 * This could be called via ext4_write_begin()
Mingming Caoa02908f2008-08-19 22:16:07 -04005117 *
Mingming Cao525f4ed2008-08-19 22:15:58 -04005118 * We need to consider the worse case, when
Mingming Caoa02908f2008-08-19 22:16:07 -04005119 * one new block per extent.
Mingming Caoa02908f2008-08-19 22:16:07 -04005120 */
5121int ext4_writepage_trans_blocks(struct inode *inode)
5122{
5123 int bpp = ext4_journal_blocks_per_page(inode);
5124 int ret;
5125
5126 ret = ext4_meta_trans_blocks(inode, bpp, 0);
5127
5128 /* Account for data blocks for journalled mode */
5129 if (ext4_should_journal_data(inode))
5130 ret += bpp;
5131 return ret;
5132}
Mingming Caof3bd1f32008-08-19 22:16:03 -04005133
5134/*
5135 * Calculate the journal credits for a chunk of data modification.
5136 *
5137 * This is called from DIO, fallocate or whoever calling
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04005138 * ext4_get_blocks() to map/allocate a chunk of contigous disk blocks.
Mingming Caof3bd1f32008-08-19 22:16:03 -04005139 *
5140 * journal buffers for data blocks are not included here, as DIO
5141 * and fallocate do no need to journal data buffers.
5142 */
5143int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
5144{
5145 return ext4_meta_trans_blocks(inode, nrblocks, 1);
5146}
5147
Mingming Caoa02908f2008-08-19 22:16:07 -04005148/*
Mingming Cao617ba132006-10-11 01:20:53 -07005149 * The caller must have previously called ext4_reserve_inode_write().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005150 * Give this, we know that the caller already has write access to iloc->bh.
5151 */
Mingming Cao617ba132006-10-11 01:20:53 -07005152int ext4_mark_iloc_dirty(handle_t *handle,
5153 struct inode *inode, struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005154{
5155 int err = 0;
5156
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05005157 if (test_opt(inode->i_sb, I_VERSION))
5158 inode_inc_iversion(inode);
5159
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005160 /* the do_update_inode consumes one bh->b_count */
5161 get_bh(iloc->bh);
5162
Mingming Caodab291a2006-10-11 01:21:01 -07005163 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
Mingming Cao617ba132006-10-11 01:20:53 -07005164 err = ext4_do_update_inode(handle, inode, iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005165 put_bh(iloc->bh);
5166 return err;
5167}
5168
5169/*
5170 * On success, We end up with an outstanding reference count against
5171 * iloc->bh. This _must_ be cleaned up later.
5172 */
5173
5174int
Mingming Cao617ba132006-10-11 01:20:53 -07005175ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
5176 struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005177{
Frank Mayhar03901312009-01-07 00:06:22 -05005178 int err;
5179
5180 err = ext4_get_inode_loc(inode, iloc);
5181 if (!err) {
5182 BUFFER_TRACE(iloc->bh, "get_write_access");
5183 err = ext4_journal_get_write_access(handle, iloc->bh);
5184 if (err) {
5185 brelse(iloc->bh);
5186 iloc->bh = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005187 }
5188 }
Mingming Cao617ba132006-10-11 01:20:53 -07005189 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005190 return err;
5191}
5192
5193/*
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005194 * Expand an inode by new_extra_isize bytes.
5195 * Returns 0 on success or negative error number on failure.
5196 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05005197static int ext4_expand_extra_isize(struct inode *inode,
5198 unsigned int new_extra_isize,
5199 struct ext4_iloc iloc,
5200 handle_t *handle)
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005201{
5202 struct ext4_inode *raw_inode;
5203 struct ext4_xattr_ibody_header *header;
5204 struct ext4_xattr_entry *entry;
5205
5206 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
5207 return 0;
5208
5209 raw_inode = ext4_raw_inode(&iloc);
5210
5211 header = IHDR(inode, raw_inode);
5212 entry = IFIRST(header);
5213
5214 /* No extended attributes present */
5215 if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) ||
5216 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
5217 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
5218 new_extra_isize);
5219 EXT4_I(inode)->i_extra_isize = new_extra_isize;
5220 return 0;
5221 }
5222
5223 /* try to expand with EAs present */
5224 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
5225 raw_inode, handle);
5226}
5227
5228/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005229 * What we do here is to mark the in-core inode as clean with respect to inode
5230 * dirtiness (it may still be data-dirty).
5231 * This means that the in-core inode may be reaped by prune_icache
5232 * without having to perform any I/O. This is a very good thing,
5233 * because *any* task may call prune_icache - even ones which
5234 * have a transaction open against a different journal.
5235 *
5236 * Is this cheating? Not really. Sure, we haven't written the
5237 * inode out, but prune_icache isn't a user-visible syncing function.
5238 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5239 * we start and wait on commits.
5240 *
5241 * Is this efficient/effective? Well, we're being nice to the system
5242 * by cleaning up our inodes proactively so they can be reaped
5243 * without I/O. But we are potentially leaving up to five seconds'
5244 * worth of inodes floating about which prune_icache wants us to
5245 * write out. One way to fix that would be to get prune_icache()
5246 * to do a write_super() to free up some memory. It has the desired
5247 * effect.
5248 */
Mingming Cao617ba132006-10-11 01:20:53 -07005249int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005250{
Mingming Cao617ba132006-10-11 01:20:53 -07005251 struct ext4_iloc iloc;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005252 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5253 static unsigned int mnt_count;
5254 int err, ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005255
5256 might_sleep();
Mingming Cao617ba132006-10-11 01:20:53 -07005257 err = ext4_reserve_inode_write(handle, inode, &iloc);
Frank Mayhar03901312009-01-07 00:06:22 -05005258 if (ext4_handle_valid(handle) &&
5259 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005260 !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {
5261 /*
5262 * We need extra buffer credits since we may write into EA block
5263 * with this same handle. If journal_extend fails, then it will
5264 * only result in a minor loss of functionality for that inode.
5265 * If this is felt to be critical, then e2fsck should be run to
5266 * force a large enough s_min_extra_isize.
5267 */
5268 if ((jbd2_journal_extend(handle,
5269 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
5270 ret = ext4_expand_extra_isize(inode,
5271 sbi->s_want_extra_isize,
5272 iloc, handle);
5273 if (ret) {
5274 EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
Aneesh Kumar K.Vc1bddad2007-10-16 18:38:25 -04005275 if (mnt_count !=
5276 le16_to_cpu(sbi->s_es->s_mnt_count)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04005277 ext4_warning(inode->i_sb, __func__,
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005278 "Unable to expand inode %lu. Delete"
5279 " some EAs or run e2fsck.",
5280 inode->i_ino);
Aneesh Kumar K.Vc1bddad2007-10-16 18:38:25 -04005281 mnt_count =
5282 le16_to_cpu(sbi->s_es->s_mnt_count);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005283 }
5284 }
5285 }
5286 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005287 if (!err)
Mingming Cao617ba132006-10-11 01:20:53 -07005288 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005289 return err;
5290}
5291
5292/*
Mingming Cao617ba132006-10-11 01:20:53 -07005293 * ext4_dirty_inode() is called from __mark_inode_dirty()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005294 *
5295 * We're really interested in the case where a file is being extended.
5296 * i_size has been changed by generic_commit_write() and we thus need
5297 * to include the updated inode in the current transaction.
5298 *
Jan Karaa269eb12009-01-26 17:04:39 +01005299 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005300 * are allocated to the file.
5301 *
5302 * If the inode is marked synchronous, we don't honour that here - doing
5303 * so would cause a commit on atime updates, which we don't bother doing.
5304 * We handle synchronous inodes at the highest possible level.
5305 */
Mingming Cao617ba132006-10-11 01:20:53 -07005306void ext4_dirty_inode(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005307{
Mingming Cao617ba132006-10-11 01:20:53 -07005308 handle_t *current_handle = ext4_journal_current_handle();
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005309 handle_t *handle;
5310
Frank Mayhar03901312009-01-07 00:06:22 -05005311 if (!ext4_handle_valid(current_handle)) {
5312 ext4_mark_inode_dirty(current_handle, inode);
5313 return;
5314 }
5315
Mingming Cao617ba132006-10-11 01:20:53 -07005316 handle = ext4_journal_start(inode, 2);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005317 if (IS_ERR(handle))
5318 goto out;
5319 if (current_handle &&
5320 current_handle->h_transaction != handle->h_transaction) {
5321 /* This task has a transaction open against a different fs */
5322 printk(KERN_EMERG "%s: transactions do not match!\n",
Harvey Harrison46e665e2008-04-17 10:38:59 -04005323 __func__);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005324 } else {
5325 jbd_debug(5, "marking dirty. outer handle=%p\n",
5326 current_handle);
Mingming Cao617ba132006-10-11 01:20:53 -07005327 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005328 }
Mingming Cao617ba132006-10-11 01:20:53 -07005329 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005330out:
5331 return;
5332}
5333
5334#if 0
5335/*
5336 * Bind an inode's backing buffer_head into this transaction, to prevent
5337 * it from being flushed to disk early. Unlike
Mingming Cao617ba132006-10-11 01:20:53 -07005338 * ext4_reserve_inode_write, this leaves behind no bh reference and
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005339 * returns no iloc structure, so the caller needs to repeat the iloc
5340 * lookup to mark the inode dirty later.
5341 */
Mingming Cao617ba132006-10-11 01:20:53 -07005342static int ext4_pin_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005343{
Mingming Cao617ba132006-10-11 01:20:53 -07005344 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005345
5346 int err = 0;
5347 if (handle) {
Mingming Cao617ba132006-10-11 01:20:53 -07005348 err = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005349 if (!err) {
5350 BUFFER_TRACE(iloc.bh, "get_write_access");
Mingming Caodab291a2006-10-11 01:21:01 -07005351 err = jbd2_journal_get_write_access(handle, iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005352 if (!err)
Frank Mayhar03901312009-01-07 00:06:22 -05005353 err = ext4_handle_dirty_metadata(handle,
5354 inode,
5355 iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005356 brelse(iloc.bh);
5357 }
5358 }
Mingming Cao617ba132006-10-11 01:20:53 -07005359 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005360 return err;
5361}
5362#endif
5363
Mingming Cao617ba132006-10-11 01:20:53 -07005364int ext4_change_inode_journal_flag(struct inode *inode, int val)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005365{
5366 journal_t *journal;
5367 handle_t *handle;
5368 int err;
5369
5370 /*
5371 * We have to be very careful here: changing a data block's
5372 * journaling status dynamically is dangerous. If we write a
5373 * data block to the journal, change the status and then delete
5374 * that block, we risk forgetting to revoke the old log record
5375 * from the journal and so a subsequent replay can corrupt data.
5376 * So, first we make sure that the journal is empty and that
5377 * nobody is changing anything.
5378 */
5379
Mingming Cao617ba132006-10-11 01:20:53 -07005380 journal = EXT4_JOURNAL(inode);
Frank Mayhar03901312009-01-07 00:06:22 -05005381 if (!journal)
5382 return 0;
Dave Hansend6995942007-07-18 08:33:51 -04005383 if (is_journal_aborted(journal))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005384 return -EROFS;
5385
Mingming Caodab291a2006-10-11 01:21:01 -07005386 jbd2_journal_lock_updates(journal);
5387 jbd2_journal_flush(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005388
5389 /*
5390 * OK, there are no updates running now, and all cached data is
5391 * synced to disk. We are now in a completely consistent state
5392 * which doesn't have anything in the journal, and we know that
5393 * no filesystem updates are running, so it is safe to modify
5394 * the inode's in-core data-journaling state flag now.
5395 */
5396
5397 if (val)
Mingming Cao617ba132006-10-11 01:20:53 -07005398 EXT4_I(inode)->i_flags |= EXT4_JOURNAL_DATA_FL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005399 else
Mingming Cao617ba132006-10-11 01:20:53 -07005400 EXT4_I(inode)->i_flags &= ~EXT4_JOURNAL_DATA_FL;
5401 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005402
Mingming Caodab291a2006-10-11 01:21:01 -07005403 jbd2_journal_unlock_updates(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005404
5405 /* Finally we can mark the inode as dirty. */
5406
Mingming Cao617ba132006-10-11 01:20:53 -07005407 handle = ext4_journal_start(inode, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005408 if (IS_ERR(handle))
5409 return PTR_ERR(handle);
5410
Mingming Cao617ba132006-10-11 01:20:53 -07005411 err = ext4_mark_inode_dirty(handle, inode);
Frank Mayhar03901312009-01-07 00:06:22 -05005412 ext4_handle_sync(handle);
Mingming Cao617ba132006-10-11 01:20:53 -07005413 ext4_journal_stop(handle);
5414 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005415
5416 return err;
5417}
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005418
5419static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
5420{
5421 return !buffer_mapped(bh);
5422}
5423
Nick Pigginc2ec1752009-03-31 15:23:21 -07005424int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005425{
Nick Pigginc2ec1752009-03-31 15:23:21 -07005426 struct page *page = vmf->page;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005427 loff_t size;
5428 unsigned long len;
5429 int ret = -EINVAL;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005430 void *fsdata;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005431 struct file *file = vma->vm_file;
5432 struct inode *inode = file->f_path.dentry->d_inode;
5433 struct address_space *mapping = inode->i_mapping;
5434
5435 /*
5436 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5437 * get i_mutex because we are already holding mmap_sem.
5438 */
5439 down_read(&inode->i_alloc_sem);
5440 size = i_size_read(inode);
5441 if (page->mapping != mapping || size <= page_offset(page)
5442 || !PageUptodate(page)) {
5443 /* page got truncated from under us? */
5444 goto out_unlock;
5445 }
5446 ret = 0;
5447 if (PageMappedToDisk(page))
5448 goto out_unlock;
5449
5450 if (page->index == size >> PAGE_CACHE_SHIFT)
5451 len = size & ~PAGE_CACHE_MASK;
5452 else
5453 len = PAGE_CACHE_SIZE;
5454
5455 if (page_has_buffers(page)) {
5456 /* return if we have all the buffers mapped */
5457 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
5458 ext4_bh_unmapped))
5459 goto out_unlock;
5460 }
5461 /*
5462 * OK, we need to fill the hole... Do write_begin write_end
5463 * to do block allocation/reservation.We are not holding
5464 * inode.i__mutex here. That allow * parallel write_begin,
5465 * write_end call. lock_page prevent this from happening
5466 * on the same page though
5467 */
5468 ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005469 len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005470 if (ret < 0)
5471 goto out_unlock;
5472 ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005473 len, len, page, fsdata);
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005474 if (ret < 0)
5475 goto out_unlock;
5476 ret = 0;
5477out_unlock:
Nick Pigginc2ec1752009-03-31 15:23:21 -07005478 if (ret)
5479 ret = VM_FAULT_SIGBUS;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005480 up_read(&inode->i_alloc_sem);
5481 return ret;
5482}