blob: f9c642b22efabb56f5ec3ae109bf2eaf75beee8a [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>
Theodore Ts'o9bffad12009-06-17 11:48:11 -040040
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040041#include "ext4_jbd2.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070042#include "xattr.h"
43#include "acl.h"
Mingming Caod2a17632008-07-14 17:52:37 -040044#include "ext4_extents.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070045
Theodore Ts'o9bffad12009-06-17 11:48:11 -040046#include <trace/events/ext4.h>
47
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -040048#define MPAGE_DA_EXTENT_TAIL 0x01
49
Jan Kara678aaf42008-07-11 19:27:31 -040050static inline int ext4_begin_ordered_truncate(struct inode *inode,
51 loff_t new_size)
52{
Jan Kara7f5aa212009-02-10 11:15:34 -050053 return jbd2_journal_begin_ordered_truncate(
54 EXT4_SB(inode->i_sb)->s_journal,
55 &EXT4_I(inode)->jinode,
56 new_size);
Jan Kara678aaf42008-07-11 19:27:31 -040057}
58
Alex Tomas64769242008-07-11 19:27:31 -040059static void ext4_invalidatepage(struct page *page, unsigned long offset);
60
Dave Kleikampac27a0e2006-10-11 01:20:50 -070061/*
62 * Test whether an inode is a fast symlink.
63 */
Mingming Cao617ba132006-10-11 01:20:53 -070064static int ext4_inode_is_fast_symlink(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070065{
Mingming Cao617ba132006-10-11 01:20:53 -070066 int ea_blocks = EXT4_I(inode)->i_file_acl ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -070067 (inode->i_sb->s_blocksize >> 9) : 0;
68
69 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
70}
71
72/*
Mingming Cao617ba132006-10-11 01:20:53 -070073 * The ext4 forget function must perform a revoke if we are freeing data
Dave Kleikampac27a0e2006-10-11 01:20:50 -070074 * which has been journaled. Metadata (eg. indirect blocks) must be
75 * revoked in all cases.
76 *
77 * "bh" may be NULL: a metadata block may have been freed from memory
78 * but there may still be a record of it in the journal, and that record
79 * still needs to be revoked.
Frank Mayhar03901312009-01-07 00:06:22 -050080 *
Curt Wohlgemuthe6b5d302009-07-13 09:07:20 -040081 * If the handle isn't valid we're not journaling, but we still need to
82 * call into ext4_journal_revoke() to put the buffer head.
Dave Kleikampac27a0e2006-10-11 01:20:50 -070083 */
Mingming Cao617ba132006-10-11 01:20:53 -070084int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -040085 struct buffer_head *bh, ext4_fsblk_t blocknr)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070086{
87 int err;
88
89 might_sleep();
90
91 BUFFER_TRACE(bh, "enter");
92
93 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
Theodore Ts'o7f4520c2009-06-13 10:09:41 -040094 "data mode %x\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070095 bh, is_metadata, inode->i_mode,
96 test_opt(inode->i_sb, DATA_FLAGS));
97
98 /* Never use the revoke function if we are doing full data
99 * journaling: there is no need to, and a V1 superblock won't
100 * support it. Otherwise, only skip the revoke on un-journaled
101 * data blocks. */
102
Mingming Cao617ba132006-10-11 01:20:53 -0700103 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
104 (!is_metadata && !ext4_should_journal_data(inode))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700105 if (bh) {
Mingming Caodab291a2006-10-11 01:21:01 -0700106 BUFFER_TRACE(bh, "call jbd2_journal_forget");
Mingming Cao617ba132006-10-11 01:20:53 -0700107 return ext4_journal_forget(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700108 }
109 return 0;
110 }
111
112 /*
113 * data!=journal && (is_metadata || should_journal_data(inode))
114 */
Mingming Cao617ba132006-10-11 01:20:53 -0700115 BUFFER_TRACE(bh, "call ext4_journal_revoke");
116 err = ext4_journal_revoke(handle, blocknr, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700117 if (err)
Harvey Harrison46e665e2008-04-17 10:38:59 -0400118 ext4_abort(inode->i_sb, __func__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700119 "error %d when attempting revoke", err);
120 BUFFER_TRACE(bh, "exit");
121 return err;
122}
123
124/*
125 * Work out how many blocks we need to proceed with the next chunk of a
126 * truncate transaction.
127 */
128static unsigned long blocks_for_truncate(struct inode *inode)
129{
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500130 ext4_lblk_t needed;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700131
132 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
133
134 /* Give ourselves just enough room to cope with inodes in which
135 * i_blocks is corrupt: we've seen disk corruptions in the past
136 * which resulted in random data in an inode which looked enough
Mingming Cao617ba132006-10-11 01:20:53 -0700137 * like a regular file for ext4 to try to delete it. Things
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700138 * will go a bit crazy if that happens, but at least we should
139 * try not to panic the whole kernel. */
140 if (needed < 2)
141 needed = 2;
142
143 /* But we need to bound the transaction so we don't overflow the
144 * journal. */
Mingming Cao617ba132006-10-11 01:20:53 -0700145 if (needed > EXT4_MAX_TRANS_DATA)
146 needed = EXT4_MAX_TRANS_DATA;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700147
Mingming Cao617ba132006-10-11 01:20:53 -0700148 return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700149}
150
151/*
152 * Truncate transactions can be complex and absolutely huge. So we need to
153 * be able to restart the transaction at a conventient checkpoint to make
154 * sure we don't overflow the journal.
155 *
156 * start_transaction gets us a new handle for a truncate transaction,
157 * and extend_transaction tries to extend the existing one a bit. If
158 * extend fails, we need to propagate the failure up and restart the
159 * transaction in the top-level truncate loop. --sct
160 */
161static handle_t *start_transaction(struct inode *inode)
162{
163 handle_t *result;
164
Mingming Cao617ba132006-10-11 01:20:53 -0700165 result = ext4_journal_start(inode, blocks_for_truncate(inode));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700166 if (!IS_ERR(result))
167 return result;
168
Mingming Cao617ba132006-10-11 01:20:53 -0700169 ext4_std_error(inode->i_sb, PTR_ERR(result));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700170 return result;
171}
172
173/*
174 * Try to extend this transaction for the purposes of truncation.
175 *
176 * Returns 0 if we managed to create more room. If we can't create more
177 * room, and the transaction must be restarted we return 1.
178 */
179static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
180{
Frank Mayhar03901312009-01-07 00:06:22 -0500181 if (!ext4_handle_valid(handle))
182 return 0;
183 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700184 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700185 if (!ext4_journal_extend(handle, blocks_for_truncate(inode)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700186 return 0;
187 return 1;
188}
189
190/*
191 * Restart the transaction associated with *handle. This does a commit,
192 * so before we call here everything must be consistently dirtied against
193 * this transaction.
194 */
Mingming Cao617ba132006-10-11 01:20:53 -0700195static int ext4_journal_test_restart(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700196{
Frank Mayhar03901312009-01-07 00:06:22 -0500197 BUG_ON(EXT4_JOURNAL(inode) == NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700198 jbd_debug(2, "restarting handle %p\n", handle);
Mingming Cao617ba132006-10-11 01:20:53 -0700199 return ext4_journal_restart(handle, blocks_for_truncate(inode));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700200}
201
202/*
203 * Called at the last iput() if i_nlink is zero.
204 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400205void ext4_delete_inode(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700206{
207 handle_t *handle;
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400208 int err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700209
Jan Kara678aaf42008-07-11 19:27:31 -0400210 if (ext4_should_order_data(inode))
211 ext4_begin_ordered_truncate(inode, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700212 truncate_inode_pages(&inode->i_data, 0);
213
214 if (is_bad_inode(inode))
215 goto no_delete;
216
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400217 handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700218 if (IS_ERR(handle)) {
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400219 ext4_std_error(inode->i_sb, PTR_ERR(handle));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700220 /*
221 * If we're going to skip the normal cleanup, we still need to
222 * make sure that the in-core orphan linked list is properly
223 * cleaned up.
224 */
Mingming Cao617ba132006-10-11 01:20:53 -0700225 ext4_orphan_del(NULL, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700226 goto no_delete;
227 }
228
229 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -0500230 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700231 inode->i_size = 0;
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400232 err = ext4_mark_inode_dirty(handle, inode);
233 if (err) {
234 ext4_warning(inode->i_sb, __func__,
235 "couldn't mark inode dirty (err %d)", err);
236 goto stop_handle;
237 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700238 if (inode->i_blocks)
Mingming Cao617ba132006-10-11 01:20:53 -0700239 ext4_truncate(inode);
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400240
241 /*
242 * ext4_ext_truncate() doesn't reserve any slop when it
243 * restarts journal transactions; therefore there may not be
244 * enough credits left in the handle to remove the inode from
245 * the orphan list and set the dtime field.
246 */
Frank Mayhar03901312009-01-07 00:06:22 -0500247 if (!ext4_handle_has_enough_credits(handle, 3)) {
Theodore Ts'obc965ab2008-08-02 21:10:38 -0400248 err = ext4_journal_extend(handle, 3);
249 if (err > 0)
250 err = ext4_journal_restart(handle, 3);
251 if (err != 0) {
252 ext4_warning(inode->i_sb, __func__,
253 "couldn't extend journal (err %d)", err);
254 stop_handle:
255 ext4_journal_stop(handle);
256 goto no_delete;
257 }
258 }
259
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700260 /*
Mingming Cao617ba132006-10-11 01:20:53 -0700261 * Kill off the orphan record which ext4_truncate created.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700262 * AKPM: I think this can be inside the above `if'.
Mingming Cao617ba132006-10-11 01:20:53 -0700263 * Note that ext4_orphan_del() has to be able to cope with the
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700264 * deletion of a non-existent orphan - this is because we don't
Mingming Cao617ba132006-10-11 01:20:53 -0700265 * know if ext4_truncate() actually created an orphan record.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700266 * (Well, we could do this if we need to, but heck - it works)
267 */
Mingming Cao617ba132006-10-11 01:20:53 -0700268 ext4_orphan_del(handle, inode);
269 EXT4_I(inode)->i_dtime = get_seconds();
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700270
271 /*
272 * One subtle ordering requirement: if anything has gone wrong
273 * (transaction abort, IO errors, whatever), then we can still
274 * do these next steps (the fs will already have been marked as
275 * having errors), but we can't free the inode if the mark_dirty
276 * fails.
277 */
Mingming Cao617ba132006-10-11 01:20:53 -0700278 if (ext4_mark_inode_dirty(handle, inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700279 /* If that failed, just do the required in-core inode clear. */
280 clear_inode(inode);
281 else
Mingming Cao617ba132006-10-11 01:20:53 -0700282 ext4_free_inode(handle, inode);
283 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700284 return;
285no_delete:
286 clear_inode(inode); /* We must guarantee clearing of inode... */
287}
288
289typedef struct {
290 __le32 *p;
291 __le32 key;
292 struct buffer_head *bh;
293} Indirect;
294
295static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
296{
297 p->key = *(p->p = v);
298 p->bh = bh;
299}
300
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700301/**
Mingming Cao617ba132006-10-11 01:20:53 -0700302 * ext4_block_to_path - parse the block number into array of offsets
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700303 * @inode: inode in question (we are only interested in its superblock)
304 * @i_block: block number to be parsed
305 * @offsets: array to store the offsets in
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400306 * @boundary: set this non-zero if the referred-to block is likely to be
307 * followed (on disk) by an indirect block.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700308 *
Mingming Cao617ba132006-10-11 01:20:53 -0700309 * To store the locations of file's data ext4 uses a data structure common
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700310 * for UNIX filesystems - tree of pointers anchored in the inode, with
311 * data blocks at leaves and indirect blocks in intermediate nodes.
312 * This function translates the block number into path in that tree -
313 * return value is the path length and @offsets[n] is the offset of
314 * pointer to (n+1)th node in the nth one. If @block is out of range
315 * (negative or too large) warning is printed and zero returned.
316 *
317 * Note: function doesn't find node addresses, so no IO is needed. All
318 * we need to know is the capacity of indirect blocks (taken from the
319 * inode->i_sb).
320 */
321
322/*
323 * Portability note: the last comparison (check that we fit into triple
324 * indirect block) is spelled differently, because otherwise on an
325 * architecture with 32-bit longs and 8Kb pages we might get into trouble
326 * if our filesystem had 8Kb blocks. We might use long long, but that would
327 * kill us on x86. Oh, well, at least the sign propagation does not matter -
328 * i_block would have to be negative in the very beginning, so we would not
329 * get there at all.
330 */
331
Mingming Cao617ba132006-10-11 01:20:53 -0700332static int ext4_block_to_path(struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400333 ext4_lblk_t i_block,
334 ext4_lblk_t offsets[4], int *boundary)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700335{
Mingming Cao617ba132006-10-11 01:20:53 -0700336 int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
337 int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
338 const long direct_blocks = EXT4_NDIR_BLOCKS,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700339 indirect_blocks = ptrs,
340 double_blocks = (1 << (ptrs_bits * 2));
341 int n = 0;
342 int final = 0;
343
344 if (i_block < 0) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400345 ext4_warning(inode->i_sb, "ext4_block_to_path", "block < 0");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700346 } else if (i_block < direct_blocks) {
347 offsets[n++] = i_block;
348 final = direct_blocks;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400349 } else if ((i_block -= direct_blocks) < indirect_blocks) {
Mingming Cao617ba132006-10-11 01:20:53 -0700350 offsets[n++] = EXT4_IND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700351 offsets[n++] = i_block;
352 final = ptrs;
353 } else if ((i_block -= indirect_blocks) < double_blocks) {
Mingming Cao617ba132006-10-11 01:20:53 -0700354 offsets[n++] = EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700355 offsets[n++] = i_block >> ptrs_bits;
356 offsets[n++] = i_block & (ptrs - 1);
357 final = ptrs;
358 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
Mingming Cao617ba132006-10-11 01:20:53 -0700359 offsets[n++] = EXT4_TIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700360 offsets[n++] = i_block >> (ptrs_bits * 2);
361 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
362 offsets[n++] = i_block & (ptrs - 1);
363 final = ptrs;
364 } else {
Eric Sandeene2b46572008-01-28 23:58:27 -0500365 ext4_warning(inode->i_sb, "ext4_block_to_path",
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400366 "block %lu > max in inode %lu",
367 i_block + direct_blocks +
368 indirect_blocks + double_blocks, inode->i_ino);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700369 }
370 if (boundary)
371 *boundary = final - 1 - (i_block & (ptrs - 1));
372 return n;
373}
374
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400375static int __ext4_check_blockref(const char *function, struct inode *inode,
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400376 __le32 *p, unsigned int max)
377{
Thiemo Nagelf73953c2009-04-07 18:46:47 -0400378 __le32 *bref = p;
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400379 unsigned int blk;
380
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400381 while (bref < p+max) {
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400382 blk = le32_to_cpu(*bref++);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400383 if (blk &&
384 unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb),
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400385 blk, 1))) {
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400386 ext4_error(inode->i_sb, function,
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400387 "invalid block reference %u "
388 "in inode #%lu", blk, inode->i_ino);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400389 return -EIO;
390 }
391 }
392 return 0;
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400393}
394
395
396#define ext4_check_indirect_blockref(inode, bh) \
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400397 __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data, \
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400398 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
399
400#define ext4_check_inode_blockref(inode) \
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400401 __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data, \
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400402 EXT4_NDIR_BLOCKS)
403
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700404/**
Mingming Cao617ba132006-10-11 01:20:53 -0700405 * ext4_get_branch - read the chain of indirect blocks leading to data
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700406 * @inode: inode in question
407 * @depth: depth of the chain (1 - direct pointer, etc.)
408 * @offsets: offsets of pointers in inode/indirect blocks
409 * @chain: place to store the result
410 * @err: here we store the error value
411 *
412 * Function fills the array of triples <key, p, bh> and returns %NULL
413 * if everything went OK or the pointer to the last filled triple
414 * (incomplete one) otherwise. Upon the return chain[i].key contains
415 * the number of (i+1)-th block in the chain (as it is stored in memory,
416 * i.e. little-endian 32-bit), chain[i].p contains the address of that
417 * number (it points into struct inode for i==0 and into the bh->b_data
418 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
419 * block for i>0 and NULL for i==0. In other words, it holds the block
420 * numbers of the chain, addresses they were taken from (and where we can
421 * verify that chain did not change) and buffer_heads hosting these
422 * numbers.
423 *
424 * Function stops when it stumbles upon zero pointer (absent block)
425 * (pointer to last triple returned, *@err == 0)
426 * or when it gets an IO error reading an indirect block
427 * (ditto, *@err == -EIO)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700428 * or when it reads all @depth-1 indirect blocks successfully and finds
429 * the whole chain, all way to the data (returns %NULL, *err == 0).
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500430 *
431 * Need to be called with
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -0500432 * down_read(&EXT4_I(inode)->i_data_sem)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700433 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500434static Indirect *ext4_get_branch(struct inode *inode, int depth,
435 ext4_lblk_t *offsets,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700436 Indirect chain[4], int *err)
437{
438 struct super_block *sb = inode->i_sb;
439 Indirect *p = chain;
440 struct buffer_head *bh;
441
442 *err = 0;
443 /* i_data is not going away, no lock needed */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400444 add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700445 if (!p->key)
446 goto no_block;
447 while (--depth) {
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400448 bh = sb_getblk(sb, le32_to_cpu(p->key));
449 if (unlikely(!bh))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700450 goto failure;
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400451
Thiemo Nagelfe2c8192009-03-31 08:36:10 -0400452 if (!bh_uptodate_or_lock(bh)) {
453 if (bh_submit_read(bh) < 0) {
454 put_bh(bh);
455 goto failure;
456 }
457 /* validate block references */
458 if (ext4_check_indirect_blockref(inode, bh)) {
459 put_bh(bh);
460 goto failure;
461 }
462 }
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400463
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400464 add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700465 /* Reader: end */
466 if (!p->key)
467 goto no_block;
468 }
469 return NULL;
470
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700471failure:
472 *err = -EIO;
473no_block:
474 return p;
475}
476
477/**
Mingming Cao617ba132006-10-11 01:20:53 -0700478 * ext4_find_near - find a place for allocation with sufficient locality
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700479 * @inode: owner
480 * @ind: descriptor of indirect block.
481 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000482 * This function returns the preferred place for block allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700483 * It is used when heuristic for sequential allocation fails.
484 * Rules are:
485 * + if there is a block to the left of our position - allocate near it.
486 * + if pointer will live in indirect block - allocate near that block.
487 * + if pointer will live in inode - allocate in the same
488 * cylinder group.
489 *
490 * In the latter case we colour the starting block by the callers PID to
491 * prevent it from clashing with concurrent allocations for a different inode
492 * in the same block group. The PID is used here so that functionally related
493 * files will be close-by on-disk.
494 *
495 * Caller must make sure that @ind is valid and will stay that way.
496 */
Mingming Cao617ba132006-10-11 01:20:53 -0700497static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700498{
Mingming Cao617ba132006-10-11 01:20:53 -0700499 struct ext4_inode_info *ei = EXT4_I(inode);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400500 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700501 __le32 *p;
Mingming Cao617ba132006-10-11 01:20:53 -0700502 ext4_fsblk_t bg_start;
Valerie Clement74d34872008-02-15 13:43:07 -0500503 ext4_fsblk_t last_block;
Mingming Cao617ba132006-10-11 01:20:53 -0700504 ext4_grpblk_t colour;
Theodore Ts'oa4912122009-03-12 12:18:34 -0400505 ext4_group_t block_group;
506 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700507
508 /* Try to find previous block */
509 for (p = ind->p - 1; p >= start; p--) {
510 if (*p)
511 return le32_to_cpu(*p);
512 }
513
514 /* No such thing, so let's try location of indirect block */
515 if (ind->bh)
516 return ind->bh->b_blocknr;
517
518 /*
519 * It is going to be referred to from the inode itself? OK, just put it
520 * into the same cylinder group then.
521 */
Theodore Ts'oa4912122009-03-12 12:18:34 -0400522 block_group = ei->i_block_group;
523 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
524 block_group &= ~(flex_size-1);
525 if (S_ISREG(inode->i_mode))
526 block_group++;
527 }
528 bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
Valerie Clement74d34872008-02-15 13:43:07 -0500529 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
530
Theodore Ts'oa4912122009-03-12 12:18:34 -0400531 /*
532 * If we are doing delayed allocation, we don't need take
533 * colour into account.
534 */
535 if (test_opt(inode->i_sb, DELALLOC))
536 return bg_start;
537
Valerie Clement74d34872008-02-15 13:43:07 -0500538 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
539 colour = (current->pid % 16) *
Mingming Cao617ba132006-10-11 01:20:53 -0700540 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
Valerie Clement74d34872008-02-15 13:43:07 -0500541 else
542 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700543 return bg_start + colour;
544}
545
546/**
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000547 * ext4_find_goal - find a preferred place for allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700548 * @inode: owner
549 * @block: block we want
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700550 * @partial: pointer to the last triple within a chain
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700551 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000552 * Normally this function find the preferred place for block allocation,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800553 * returns it.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700554 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500555static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400556 Indirect *partial)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700557{
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700558 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -0400559 * XXX need to get goal block from mballoc's data structures
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700560 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700561
Mingming Cao617ba132006-10-11 01:20:53 -0700562 return ext4_find_near(inode, partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700563}
564
565/**
Mingming Cao617ba132006-10-11 01:20:53 -0700566 * ext4_blks_to_allocate: Look up the block map and count the number
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700567 * of direct blocks need to be allocated for the given branch.
568 *
569 * @branch: chain of indirect blocks
570 * @k: number of blocks need for indirect blocks
571 * @blks: number of data blocks to be mapped.
572 * @blocks_to_boundary: the offset in the indirect block
573 *
574 * return the total number of blocks to be allocate, including the
575 * direct and indirect blocks.
576 */
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500577static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400578 int blocks_to_boundary)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700579{
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500580 unsigned int count = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700581
582 /*
583 * Simple case, [t,d]Indirect block(s) has not allocated yet
584 * then it's clear blocks on that path have not allocated
585 */
586 if (k > 0) {
587 /* right now we don't handle cross boundary allocation */
588 if (blks < blocks_to_boundary + 1)
589 count += blks;
590 else
591 count += blocks_to_boundary + 1;
592 return count;
593 }
594
595 count++;
596 while (count < blks && count <= blocks_to_boundary &&
597 le32_to_cpu(*(branch[0].p + count)) == 0) {
598 count++;
599 }
600 return count;
601}
602
603/**
Mingming Cao617ba132006-10-11 01:20:53 -0700604 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700605 * @indirect_blks: the number of blocks need to allocate for indirect
606 * blocks
607 *
608 * @new_blocks: on return it will store the new block numbers for
609 * the indirect blocks(if needed) and the first direct block,
610 * @blks: on return it will store the total number of allocated
611 * direct blocks
612 */
Mingming Cao617ba132006-10-11 01:20:53 -0700613static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400614 ext4_lblk_t iblock, ext4_fsblk_t goal,
615 int indirect_blks, int blks,
616 ext4_fsblk_t new_blocks[4], int *err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700617{
Theodore Ts'o815a1132009-01-01 23:59:43 -0500618 struct ext4_allocation_request ar;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700619 int target, i;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400620 unsigned long count = 0, blk_allocated = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700621 int index = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700622 ext4_fsblk_t current_block = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700623 int ret = 0;
624
625 /*
626 * Here we try to allocate the requested multiple blocks at once,
627 * on a best-effort basis.
628 * To build a branch, we should allocate blocks for
629 * the indirect blocks(if not allocated yet), and at least
630 * the first direct block of this branch. That's the
631 * minimum number of blocks need to allocate(required)
632 */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400633 /* first we try to allocate the indirect blocks */
634 target = indirect_blks;
635 while (target > 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700636 count = target;
637 /* allocating blocks for indirect blocks and direct blocks */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400638 current_block = ext4_new_meta_blocks(handle, inode,
639 goal, &count, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700640 if (*err)
641 goto failed_out;
642
643 target -= count;
644 /* allocate blocks for indirect blocks */
645 while (index < indirect_blks && count) {
646 new_blocks[index++] = current_block++;
647 count--;
648 }
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400649 if (count > 0) {
650 /*
651 * save the new block number
652 * for the first direct block
653 */
654 new_blocks[index] = current_block;
655 printk(KERN_INFO "%s returned more blocks than "
656 "requested\n", __func__);
657 WARN_ON(1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700658 break;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400659 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700660 }
661
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400662 target = blks - count ;
663 blk_allocated = count;
664 if (!target)
665 goto allocated;
666 /* Now allocate data blocks */
Theodore Ts'o815a1132009-01-01 23:59:43 -0500667 memset(&ar, 0, sizeof(ar));
668 ar.inode = inode;
669 ar.goal = goal;
670 ar.len = target;
671 ar.logical = iblock;
672 if (S_ISREG(inode->i_mode))
673 /* enable in-core preallocation only for regular files */
674 ar.flags = EXT4_MB_HINT_DATA;
675
676 current_block = ext4_mb_new_blocks(handle, &ar, err);
677
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400678 if (*err && (target == blks)) {
679 /*
680 * if the allocation failed and we didn't allocate
681 * any blocks before
682 */
683 goto failed_out;
684 }
685 if (!*err) {
686 if (target == blks) {
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400687 /*
688 * save the new block number
689 * for the first direct block
690 */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400691 new_blocks[index] = current_block;
692 }
Theodore Ts'o815a1132009-01-01 23:59:43 -0500693 blk_allocated += ar.len;
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400694 }
695allocated:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700696 /* total number of blocks allocated for direct blocks */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400697 ret = blk_allocated;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700698 *err = 0;
699 return ret;
700failed_out:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400701 for (i = 0; i < index; i++)
Alex Tomasc9de5602008-01-29 00:19:52 -0500702 ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700703 return ret;
704}
705
706/**
Mingming Cao617ba132006-10-11 01:20:53 -0700707 * ext4_alloc_branch - allocate and set up a chain of blocks.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700708 * @inode: owner
709 * @indirect_blks: number of allocated indirect blocks
710 * @blks: number of allocated direct blocks
711 * @offsets: offsets (in the blocks) to store the pointers to next.
712 * @branch: place to store the chain in.
713 *
714 * This function allocates blocks, zeroes out all but the last one,
715 * links them into chain and (if we are synchronous) writes them to disk.
716 * In other words, it prepares a branch that can be spliced onto the
717 * inode. It stores the information about that chain in the branch[], in
Mingming Cao617ba132006-10-11 01:20:53 -0700718 * the same format as ext4_get_branch() would do. We are calling it after
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700719 * we had read the existing part of chain and partial points to the last
720 * triple of that (one with zero ->key). Upon the exit we have the same
Mingming Cao617ba132006-10-11 01:20:53 -0700721 * picture as after the successful ext4_get_block(), except that in one
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700722 * place chain is disconnected - *branch->p is still zero (we did not
723 * set the last link), but branch->key contains the number that should
724 * be placed into *branch->p to fill that gap.
725 *
726 * If allocation fails we free all blocks we've allocated (and forget
727 * their buffer_heads) and return the error value the from failed
Mingming Cao617ba132006-10-11 01:20:53 -0700728 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700729 * as described above and return 0.
730 */
Mingming Cao617ba132006-10-11 01:20:53 -0700731static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400732 ext4_lblk_t iblock, int indirect_blks,
733 int *blks, ext4_fsblk_t goal,
734 ext4_lblk_t *offsets, Indirect *branch)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700735{
736 int blocksize = inode->i_sb->s_blocksize;
737 int i, n = 0;
738 int err = 0;
739 struct buffer_head *bh;
740 int num;
Mingming Cao617ba132006-10-11 01:20:53 -0700741 ext4_fsblk_t new_blocks[4];
742 ext4_fsblk_t current_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700743
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400744 num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700745 *blks, new_blocks, &err);
746 if (err)
747 return err;
748
749 branch[0].key = cpu_to_le32(new_blocks[0]);
750 /*
751 * metadata blocks and data blocks are allocated.
752 */
753 for (n = 1; n <= indirect_blks; n++) {
754 /*
755 * Get buffer_head for parent block, zero it out
756 * and set the pointer to new one, then send
757 * parent to disk.
758 */
759 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
760 branch[n].bh = bh;
761 lock_buffer(bh);
762 BUFFER_TRACE(bh, "call get_create_access");
Mingming Cao617ba132006-10-11 01:20:53 -0700763 err = ext4_journal_get_create_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700764 if (err) {
765 unlock_buffer(bh);
766 brelse(bh);
767 goto failed;
768 }
769
770 memset(bh->b_data, 0, blocksize);
771 branch[n].p = (__le32 *) bh->b_data + offsets[n];
772 branch[n].key = cpu_to_le32(new_blocks[n]);
773 *branch[n].p = branch[n].key;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400774 if (n == indirect_blks) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700775 current_block = new_blocks[n];
776 /*
777 * End of chain, update the last new metablock of
778 * the chain to point to the new allocated
779 * data blocks numbers
780 */
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400781 for (i = 1; i < num; i++)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700782 *(branch[n].p + i) = cpu_to_le32(++current_block);
783 }
784 BUFFER_TRACE(bh, "marking uptodate");
785 set_buffer_uptodate(bh);
786 unlock_buffer(bh);
787
Frank Mayhar03901312009-01-07 00:06:22 -0500788 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
789 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700790 if (err)
791 goto failed;
792 }
793 *blks = num;
794 return err;
795failed:
796 /* Allocation failed, free what we already allocated */
797 for (i = 1; i <= n ; i++) {
Mingming Caodab291a2006-10-11 01:21:01 -0700798 BUFFER_TRACE(branch[i].bh, "call jbd2_journal_forget");
Mingming Cao617ba132006-10-11 01:20:53 -0700799 ext4_journal_forget(handle, branch[i].bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700800 }
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400801 for (i = 0; i < indirect_blks; i++)
Alex Tomasc9de5602008-01-29 00:19:52 -0500802 ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700803
Alex Tomasc9de5602008-01-29 00:19:52 -0500804 ext4_free_blocks(handle, inode, new_blocks[i], num, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700805
806 return err;
807}
808
809/**
Mingming Cao617ba132006-10-11 01:20:53 -0700810 * ext4_splice_branch - splice the allocated branch onto inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700811 * @inode: owner
812 * @block: (logical) number of block we are adding
813 * @chain: chain of indirect blocks (with a missing link - see
Mingming Cao617ba132006-10-11 01:20:53 -0700814 * ext4_alloc_branch)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700815 * @where: location of missing link
816 * @num: number of indirect blocks we are adding
817 * @blks: number of direct blocks we are adding
818 *
819 * This function fills the missing link and does all housekeeping needed in
820 * inode (->i_blocks, etc.). In case of success we end up with the full
821 * chain to new block and return 0.
822 */
Mingming Cao617ba132006-10-11 01:20:53 -0700823static int ext4_splice_branch(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400824 ext4_lblk_t block, Indirect *where, int num,
825 int blks)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700826{
827 int i;
828 int err = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700829 ext4_fsblk_t current_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700830
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700831 /*
832 * If we're splicing into a [td]indirect block (as opposed to the
833 * inode) then we need to get write access to the [td]indirect block
834 * before the splice.
835 */
836 if (where->bh) {
837 BUFFER_TRACE(where->bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -0700838 err = ext4_journal_get_write_access(handle, where->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700839 if (err)
840 goto err_out;
841 }
842 /* That's it */
843
844 *where->p = where->key;
845
846 /*
847 * Update the host buffer_head or inode to point to more just allocated
848 * direct blocks blocks
849 */
850 if (num == 0 && blks > 1) {
851 current_block = le32_to_cpu(where->key) + 1;
852 for (i = 1; i < blks; i++)
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400853 *(where->p + i) = cpu_to_le32(current_block++);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700854 }
855
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700856 /* We are done with atomic stuff, now do the rest of housekeeping */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700857 /* had we spliced it onto indirect block? */
858 if (where->bh) {
859 /*
860 * If we spliced it onto an indirect block, we haven't
861 * altered the inode. Note however that if it is being spliced
862 * onto an indirect block at the very end of the file (the
863 * file is growing) then we *will* alter the inode to reflect
864 * the new i_size. But that is not done here - it is done in
Mingming Cao617ba132006-10-11 01:20:53 -0700865 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700866 */
867 jbd_debug(5, "splicing indirect only\n");
Frank Mayhar03901312009-01-07 00:06:22 -0500868 BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
869 err = ext4_handle_dirty_metadata(handle, inode, where->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700870 if (err)
871 goto err_out;
872 } else {
873 /*
874 * OK, we spliced it into the inode itself on a direct block.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700875 */
Theodore Ts'o41591752009-06-15 03:41:23 -0400876 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700877 jbd_debug(5, "splicing direct\n");
878 }
879 return err;
880
881err_out:
882 for (i = 1; i <= num; i++) {
Mingming Caodab291a2006-10-11 01:21:01 -0700883 BUFFER_TRACE(where[i].bh, "call jbd2_journal_forget");
Mingming Cao617ba132006-10-11 01:20:53 -0700884 ext4_journal_forget(handle, where[i].bh);
Alex Tomasc9de5602008-01-29 00:19:52 -0500885 ext4_free_blocks(handle, inode,
886 le32_to_cpu(where[i-1].key), 1, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700887 }
Alex Tomasc9de5602008-01-29 00:19:52 -0500888 ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700889
890 return err;
891}
892
893/*
Theodore Ts'ob920c752009-05-14 00:54:29 -0400894 * The ext4_ind_get_blocks() function handles non-extents inodes
895 * (i.e., using the traditional indirect/double-indirect i_blocks
896 * scheme) for ext4_get_blocks().
897 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700898 * Allocation strategy is simple: if we have to allocate something, we will
899 * have to go the whole way to leaf. So let's do it before attaching anything
900 * to tree, set linkage between the newborn blocks, write them if sync is
901 * required, recheck the path, free and repeat if check fails, otherwise
902 * set the last missing link (that will protect us from any truncate-generated
903 * removals - all blocks on the path are immune now) and possibly force the
904 * write on the parent block.
905 * That has a nice additional property: no special recovery from the failed
906 * allocations is needed - we simply release blocks and do not touch anything
907 * reachable from inode.
908 *
909 * `handle' can be NULL if create == 0.
910 *
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700911 * return > 0, # of blocks mapped or allocated.
912 * return = 0, if plain lookup failed.
913 * return < 0, error case.
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500914 *
Theodore Ts'ob920c752009-05-14 00:54:29 -0400915 * The ext4_ind_get_blocks() function should be called with
916 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
917 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
918 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
919 * blocks.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700920 */
Theodore Ts'oe4d996c2009-05-12 00:25:28 -0400921static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400922 ext4_lblk_t iblock, unsigned int maxblocks,
923 struct buffer_head *bh_result,
924 int flags)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700925{
926 int err = -EIO;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500927 ext4_lblk_t offsets[4];
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700928 Indirect chain[4];
929 Indirect *partial;
Mingming Cao617ba132006-10-11 01:20:53 -0700930 ext4_fsblk_t goal;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700931 int indirect_blks;
932 int blocks_to_boundary = 0;
933 int depth;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700934 int count = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700935 ext4_fsblk_t first_block = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700936
Alex Tomasa86c6182006-10-11 01:21:03 -0700937 J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
Theodore Ts'oc2177052009-05-14 00:58:52 -0400938 J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500939 depth = ext4_block_to_path(inode, iblock, offsets,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400940 &blocks_to_boundary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700941
942 if (depth == 0)
943 goto out;
944
Mingming Cao617ba132006-10-11 01:20:53 -0700945 partial = ext4_get_branch(inode, depth, offsets, chain, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700946
947 /* Simplest case - block found, no allocation needed */
948 if (!partial) {
949 first_block = le32_to_cpu(chain[depth - 1].key);
950 clear_buffer_new(bh_result);
951 count++;
952 /*map more blocks*/
953 while (count < maxblocks && count <= blocks_to_boundary) {
Mingming Cao617ba132006-10-11 01:20:53 -0700954 ext4_fsblk_t blk;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700955
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700956 blk = le32_to_cpu(*(chain[depth-1].p + count));
957
958 if (blk == first_block + count)
959 count++;
960 else
961 break;
962 }
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -0500963 goto got_it;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700964 }
965
966 /* Next simple case - plain lookup or failed read of indirect block */
Theodore Ts'oc2177052009-05-14 00:58:52 -0400967 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700968 goto cleanup;
969
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700970 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -0400971 * Okay, we need to do block allocation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700972 */
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800973 goal = ext4_find_goal(inode, iblock, partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700974
975 /* the number of blocks need to allocate for [d,t]indirect blocks */
976 indirect_blks = (chain + depth) - partial - 1;
977
978 /*
979 * Next look up the indirect map to count the totoal number of
980 * direct blocks to allocate for this branch.
981 */
Mingming Cao617ba132006-10-11 01:20:53 -0700982 count = ext4_blks_to_allocate(partial, indirect_blks,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700983 maxblocks, blocks_to_boundary);
984 /*
Mingming Cao617ba132006-10-11 01:20:53 -0700985 * Block out ext4_truncate while we alter the tree
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700986 */
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400987 err = ext4_alloc_branch(handle, inode, iblock, indirect_blks,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -0400988 &count, goal,
989 offsets + (partial - chain), partial);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700990
991 /*
Mingming Cao617ba132006-10-11 01:20:53 -0700992 * The ext4_splice_branch call will free and forget any buffers
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700993 * on the new chain if there is a failure, but that risks using
994 * up transaction credits, especially for bitmaps where the
995 * credits cannot be returned. Can we handle this somehow? We
996 * may need to return -EAGAIN upwards in the worst case. --sct
997 */
998 if (!err)
Mingming Cao617ba132006-10-11 01:20:53 -0700999 err = ext4_splice_branch(handle, inode, iblock,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001000 partial, indirect_blks, count);
1001 else
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001002 goto cleanup;
1003
1004 set_buffer_new(bh_result);
1005got_it:
1006 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
1007 if (count > blocks_to_boundary)
1008 set_buffer_boundary(bh_result);
1009 err = count;
1010 /* Clean up and exit */
1011 partial = chain + depth - 1; /* the whole chain */
1012cleanup:
1013 while (partial > chain) {
1014 BUFFER_TRACE(partial->bh, "call brelse");
1015 brelse(partial->bh);
1016 partial--;
1017 }
1018 BUFFER_TRACE(bh_result, "returned");
1019out:
1020 return err;
1021}
1022
Mingming Cao60e58e02009-01-22 18:13:05 +01001023qsize_t ext4_get_reserved_space(struct inode *inode)
1024{
1025 unsigned long long total;
1026
1027 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1028 total = EXT4_I(inode)->i_reserved_data_blocks +
1029 EXT4_I(inode)->i_reserved_meta_blocks;
1030 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1031
1032 return total;
1033}
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001034/*
1035 * Calculate the number of metadata blocks need to reserve
1036 * to allocate @blocks for non extent file based file
1037 */
1038static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
1039{
1040 int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
1041 int ind_blks, dind_blks, tind_blks;
1042
1043 /* number of new indirect blocks needed */
1044 ind_blks = (blocks + icap - 1) / icap;
1045
1046 dind_blks = (ind_blks + icap - 1) / icap;
1047
1048 tind_blks = 1;
1049
1050 return ind_blks + dind_blks + tind_blks;
1051}
1052
1053/*
1054 * Calculate the number of metadata blocks need to reserve
1055 * to allocate given number of blocks
1056 */
1057static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
1058{
Mingming Caocd213222008-08-19 22:16:59 -04001059 if (!blocks)
1060 return 0;
1061
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001062 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
1063 return ext4_ext_calc_metadata_amount(inode, blocks);
1064
1065 return ext4_indirect_calc_metadata_amount(inode, blocks);
1066}
1067
1068static void ext4_da_update_reserve_space(struct inode *inode, int used)
1069{
1070 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1071 int total, mdb, mdb_free;
1072
1073 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1074 /* recalculate the number of metablocks still need to be reserved */
1075 total = EXT4_I(inode)->i_reserved_data_blocks - used;
1076 mdb = ext4_calc_metadata_amount(inode, total);
1077
1078 /* figure out how many metablocks to release */
1079 BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
1080 mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
1081
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04001082 if (mdb_free) {
1083 /* Account for allocated meta_blocks */
1084 mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001085
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04001086 /* update fs dirty blocks counter */
1087 percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free);
1088 EXT4_I(inode)->i_allocated_meta_blocks = 0;
1089 EXT4_I(inode)->i_reserved_meta_blocks = mdb;
1090 }
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001091
1092 /* update per-inode reservations */
1093 BUG_ON(used > EXT4_I(inode)->i_reserved_data_blocks);
1094 EXT4_I(inode)->i_reserved_data_blocks -= used;
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001095 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Cao60e58e02009-01-22 18:13:05 +01001096
1097 /*
1098 * free those over-booking quota for metadata blocks
1099 */
Mingming Cao60e58e02009-01-22 18:13:05 +01001100 if (mdb_free)
1101 vfs_dq_release_reservation_block(inode, mdb_free);
Aneesh Kumar K.Vd6014302009-03-27 22:36:43 -04001102
1103 /*
1104 * If we have done all the pending block allocations and if
1105 * there aren't any writers on the inode, we can discard the
1106 * inode's preallocations.
1107 */
1108 if (!total && (atomic_read(&inode->i_writecount) == 0))
1109 ext4_discard_preallocations(inode);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001110}
1111
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001112static int check_block_validity(struct inode *inode, sector_t logical,
1113 sector_t phys, int len)
1114{
1115 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), phys, len)) {
1116 ext4_error(inode->i_sb, "check_block_validity",
1117 "inode #%lu logical block %llu mapped to %llu "
1118 "(size %d)", inode->i_ino,
1119 (unsigned long long) logical,
1120 (unsigned long long) phys, len);
1121 WARN_ON(1);
1122 return -EIO;
1123 }
1124 return 0;
1125}
1126
Mingming Caof5ab0d12008-02-25 15:29:55 -05001127/*
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04001128 * The ext4_get_blocks() function tries to look up the requested blocks,
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001129 * and returns if the blocks are already mapped.
Mingming Caof5ab0d12008-02-25 15:29:55 -05001130 *
Mingming Caof5ab0d12008-02-25 15:29:55 -05001131 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1132 * and store the allocated blocks in the result buffer head and mark it
1133 * mapped.
1134 *
1135 * If file type is extents based, it will call ext4_ext_get_blocks(),
Theodore Ts'oe4d996c2009-05-12 00:25:28 -04001136 * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
Mingming Caof5ab0d12008-02-25 15:29:55 -05001137 * based files
1138 *
1139 * On success, it returns the number of blocks being mapped or allocate.
1140 * if create==0 and the blocks are pre-allocated and uninitialized block,
1141 * the result buffer head is unmapped. If the create ==1, it will make sure
1142 * the buffer head is mapped.
1143 *
1144 * It returns 0 if plain look up failed (blocks have not been allocated), in
1145 * that casem, buffer head is unmapped
1146 *
1147 * It returns the error in case of allocation failure.
1148 */
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04001149int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
1150 unsigned int max_blocks, struct buffer_head *bh,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001151 int flags)
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001152{
1153 int retval;
Mingming Caof5ab0d12008-02-25 15:29:55 -05001154
1155 clear_buffer_mapped(bh);
Aneesh Kumar K.V2a8964d2009-05-14 17:05:39 -04001156 clear_buffer_unwritten(bh);
Mingming Caof5ab0d12008-02-25 15:29:55 -05001157
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001158 /*
Theodore Ts'ob920c752009-05-14 00:54:29 -04001159 * Try to see if we can get the block without requesting a new
1160 * file system block.
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001161 */
1162 down_read((&EXT4_I(inode)->i_data_sem));
1163 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
1164 retval = ext4_ext_get_blocks(handle, inode, block, max_blocks,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001165 bh, 0);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001166 } else {
Theodore Ts'oe4d996c2009-05-12 00:25:28 -04001167 retval = ext4_ind_get_blocks(handle, inode, block, max_blocks,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001168 bh, 0);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001169 }
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001170 up_read((&EXT4_I(inode)->i_data_sem));
Mingming Caof5ab0d12008-02-25 15:29:55 -05001171
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001172 if (retval > 0 && buffer_mapped(bh)) {
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001173 int ret = check_block_validity(inode, block,
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001174 bh->b_blocknr, retval);
1175 if (ret != 0)
1176 return ret;
1177 }
1178
Mingming Caof5ab0d12008-02-25 15:29:55 -05001179 /* If it is only a block(s) look up */
Theodore Ts'oc2177052009-05-14 00:58:52 -04001180 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001181 return retval;
1182
1183 /*
Mingming Caof5ab0d12008-02-25 15:29:55 -05001184 * Returns if the blocks have already allocated
1185 *
1186 * Note that if blocks have been preallocated
1187 * ext4_ext_get_block() returns th create = 0
1188 * with buffer head unmapped.
1189 */
1190 if (retval > 0 && buffer_mapped(bh))
1191 return retval;
1192
1193 /*
Aneesh Kumar K.V2a8964d2009-05-14 17:05:39 -04001194 * When we call get_blocks without the create flag, the
1195 * BH_Unwritten flag could have gotten set if the blocks
1196 * requested were part of a uninitialized extent. We need to
1197 * clear this flag now that we are committed to convert all or
1198 * part of the uninitialized extent to be an initialized
1199 * extent. This is because we need to avoid the combination
1200 * of BH_Unwritten and BH_Mapped flags being simultaneously
1201 * set on the buffer_head.
1202 */
1203 clear_buffer_unwritten(bh);
1204
1205 /*
Mingming Caof5ab0d12008-02-25 15:29:55 -05001206 * New blocks allocate and/or writing to uninitialized extent
1207 * will possibly result in updating i_data, so we take
1208 * the write lock of i_data_sem, and call get_blocks()
1209 * with create == 1 flag.
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001210 */
1211 down_write((&EXT4_I(inode)->i_data_sem));
Mingming Caod2a17632008-07-14 17:52:37 -04001212
1213 /*
1214 * if the caller is from delayed allocation writeout path
1215 * we have already reserved fs blocks for allocation
1216 * let the underlying get_block() function know to
1217 * avoid double accounting
1218 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04001219 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
Mingming Caod2a17632008-07-14 17:52:37 -04001220 EXT4_I(inode)->i_delalloc_reserved_flag = 1;
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001221 /*
1222 * We need to check for EXT4 here because migrate
1223 * could have changed the inode type in between
1224 */
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001225 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
1226 retval = ext4_ext_get_blocks(handle, inode, block, max_blocks,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001227 bh, flags);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001228 } else {
Theodore Ts'oe4d996c2009-05-12 00:25:28 -04001229 retval = ext4_ind_get_blocks(handle, inode, block,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001230 max_blocks, bh, flags);
Aneesh Kumar K.V267e4db2008-04-29 08:11:12 -04001231
1232 if (retval > 0 && buffer_new(bh)) {
1233 /*
1234 * We allocated new blocks which will result in
1235 * i_data's format changing. Force the migrate
1236 * to fail by clearing migrate flags
1237 */
1238 EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags &
1239 ~EXT4_EXT_MIGRATE;
1240 }
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001241 }
Mingming Caod2a17632008-07-14 17:52:37 -04001242
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04001243 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
Mingming Caod2a17632008-07-14 17:52:37 -04001244 EXT4_I(inode)->i_delalloc_reserved_flag = 0;
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04001245
1246 /*
1247 * Update reserved blocks/metadata blocks after successful
1248 * block allocation which had been deferred till now.
1249 */
1250 if ((retval > 0) && (flags & EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE))
1251 ext4_da_update_reserve_space(inode, retval);
Mingming Caod2a17632008-07-14 17:52:37 -04001252
Aneesh Kumar K.V4df3d262008-01-28 23:58:29 -05001253 up_write((&EXT4_I(inode)->i_data_sem));
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001254 if (retval > 0 && buffer_mapped(bh)) {
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001255 int ret = check_block_validity(inode, block,
Theodore Ts'o6fd058f2009-05-17 15:38:01 -04001256 bh->b_blocknr, retval);
1257 if (ret != 0)
1258 return ret;
1259 }
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001260 return retval;
1261}
1262
Mingming Caof3bd1f32008-08-19 22:16:03 -04001263/* Maximum number of blocks we map for direct IO at once. */
1264#define DIO_MAX_BLOCKS 4096
1265
Eric Sandeen6873fa02008-10-07 00:46:36 -04001266int ext4_get_block(struct inode *inode, sector_t iblock,
1267 struct buffer_head *bh_result, int create)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001268{
Dmitriy Monakhov3e4fdaf2007-02-10 01:46:35 -08001269 handle_t *handle = ext4_journal_current_handle();
Jan Kara7fb54092008-02-10 01:08:38 -05001270 int ret = 0, started = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001271 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
Mingming Caof3bd1f32008-08-19 22:16:03 -04001272 int dio_credits;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001273
Jan Kara7fb54092008-02-10 01:08:38 -05001274 if (create && !handle) {
1275 /* Direct IO write... */
1276 if (max_blocks > DIO_MAX_BLOCKS)
1277 max_blocks = DIO_MAX_BLOCKS;
Mingming Caof3bd1f32008-08-19 22:16:03 -04001278 dio_credits = ext4_chunk_trans_blocks(inode, max_blocks);
1279 handle = ext4_journal_start(inode, dio_credits);
Jan Kara7fb54092008-02-10 01:08:38 -05001280 if (IS_ERR(handle)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001281 ret = PTR_ERR(handle);
Jan Kara7fb54092008-02-10 01:08:38 -05001282 goto out;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001283 }
Jan Kara7fb54092008-02-10 01:08:38 -05001284 started = 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001285 }
1286
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04001287 ret = ext4_get_blocks(handle, inode, iblock, max_blocks, bh_result,
Theodore Ts'oc2177052009-05-14 00:58:52 -04001288 create ? EXT4_GET_BLOCKS_CREATE : 0);
Jan Kara7fb54092008-02-10 01:08:38 -05001289 if (ret > 0) {
1290 bh_result->b_size = (ret << inode->i_blkbits);
1291 ret = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001292 }
Jan Kara7fb54092008-02-10 01:08:38 -05001293 if (started)
1294 ext4_journal_stop(handle);
1295out:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001296 return ret;
1297}
1298
1299/*
1300 * `handle' can be NULL if create is zero
1301 */
Mingming Cao617ba132006-10-11 01:20:53 -07001302struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001303 ext4_lblk_t block, int create, int *errp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001304{
1305 struct buffer_head dummy;
1306 int fatal = 0, err;
Jan Kara03f5d8b2009-06-09 00:17:05 -04001307 int flags = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001308
1309 J_ASSERT(handle != NULL || create == 0);
1310
1311 dummy.b_state = 0;
1312 dummy.b_blocknr = -1000;
1313 buffer_trace_init(&dummy.b_history);
Theodore Ts'oc2177052009-05-14 00:58:52 -04001314 if (create)
1315 flags |= EXT4_GET_BLOCKS_CREATE;
1316 err = ext4_get_blocks(handle, inode, block, 1, &dummy, flags);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001317 /*
Theodore Ts'oc2177052009-05-14 00:58:52 -04001318 * ext4_get_blocks() returns number of blocks mapped. 0 in
1319 * case of a HOLE.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001320 */
1321 if (err > 0) {
1322 if (err > 1)
1323 WARN_ON(1);
1324 err = 0;
1325 }
1326 *errp = err;
1327 if (!err && buffer_mapped(&dummy)) {
1328 struct buffer_head *bh;
1329 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
1330 if (!bh) {
1331 *errp = -EIO;
1332 goto err;
1333 }
1334 if (buffer_new(&dummy)) {
1335 J_ASSERT(create != 0);
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001336 J_ASSERT(handle != NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001337
1338 /*
1339 * Now that we do not always journal data, we should
1340 * keep in mind whether this should always journal the
1341 * new buffer as metadata. For now, regular file
Mingming Cao617ba132006-10-11 01:20:53 -07001342 * writes use ext4_get_block instead, so it's not a
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001343 * problem.
1344 */
1345 lock_buffer(bh);
1346 BUFFER_TRACE(bh, "call get_create_access");
Mingming Cao617ba132006-10-11 01:20:53 -07001347 fatal = ext4_journal_get_create_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001348 if (!fatal && !buffer_uptodate(bh)) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001349 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001350 set_buffer_uptodate(bh);
1351 }
1352 unlock_buffer(bh);
Frank Mayhar03901312009-01-07 00:06:22 -05001353 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1354 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001355 if (!fatal)
1356 fatal = err;
1357 } else {
1358 BUFFER_TRACE(bh, "not a new buffer");
1359 }
1360 if (fatal) {
1361 *errp = fatal;
1362 brelse(bh);
1363 bh = NULL;
1364 }
1365 return bh;
1366 }
1367err:
1368 return NULL;
1369}
1370
Mingming Cao617ba132006-10-11 01:20:53 -07001371struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001372 ext4_lblk_t block, int create, int *err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001373{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001374 struct buffer_head *bh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001375
Mingming Cao617ba132006-10-11 01:20:53 -07001376 bh = ext4_getblk(handle, inode, block, create, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001377 if (!bh)
1378 return bh;
1379 if (buffer_uptodate(bh))
1380 return bh;
1381 ll_rw_block(READ_META, 1, &bh);
1382 wait_on_buffer(bh);
1383 if (buffer_uptodate(bh))
1384 return bh;
1385 put_bh(bh);
1386 *err = -EIO;
1387 return NULL;
1388}
1389
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001390static int walk_page_buffers(handle_t *handle,
1391 struct buffer_head *head,
1392 unsigned from,
1393 unsigned to,
1394 int *partial,
1395 int (*fn)(handle_t *handle,
1396 struct buffer_head *bh))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001397{
1398 struct buffer_head *bh;
1399 unsigned block_start, block_end;
1400 unsigned blocksize = head->b_size;
1401 int err, ret = 0;
1402 struct buffer_head *next;
1403
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001404 for (bh = head, block_start = 0;
1405 ret == 0 && (bh != head || !block_start);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001406 block_start = block_end, bh = next) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001407 next = bh->b_this_page;
1408 block_end = block_start + blocksize;
1409 if (block_end <= from || block_start >= to) {
1410 if (partial && !buffer_uptodate(bh))
1411 *partial = 1;
1412 continue;
1413 }
1414 err = (*fn)(handle, bh);
1415 if (!ret)
1416 ret = err;
1417 }
1418 return ret;
1419}
1420
1421/*
1422 * To preserve ordering, it is essential that the hole instantiation and
1423 * the data write be encapsulated in a single transaction. We cannot
Mingming Cao617ba132006-10-11 01:20:53 -07001424 * close off a transaction and start a new one between the ext4_get_block()
Mingming Caodab291a2006-10-11 01:21:01 -07001425 * and the commit_write(). So doing the jbd2_journal_start at the start of
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001426 * prepare_write() is the right place.
1427 *
Mingming Cao617ba132006-10-11 01:20:53 -07001428 * Also, this function can nest inside ext4_writepage() ->
1429 * block_write_full_page(). In that case, we *know* that ext4_writepage()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001430 * has generated enough buffer credits to do the whole page. So we won't
1431 * block on the journal in that case, which is good, because the caller may
1432 * be PF_MEMALLOC.
1433 *
Mingming Cao617ba132006-10-11 01:20:53 -07001434 * By accident, ext4 can be reentered when a transaction is open via
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001435 * quota file writes. If we were to commit the transaction while thus
1436 * reentered, there can be a deadlock - we would be holding a quota
1437 * lock, and the commit would never complete if another thread had a
1438 * transaction open and was blocking on the quota lock - a ranking
1439 * violation.
1440 *
Mingming Caodab291a2006-10-11 01:21:01 -07001441 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001442 * will _not_ run commit under these circumstances because handle->h_ref
1443 * is elevated. We'll still have enough credits for the tiny quotafile
1444 * write.
1445 */
1446static int do_journal_get_write_access(handle_t *handle,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001447 struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001448{
1449 if (!buffer_mapped(bh) || buffer_freed(bh))
1450 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -07001451 return ext4_journal_get_write_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001452}
1453
Nick Pigginbfc1af62007-10-16 01:25:05 -07001454static int ext4_write_begin(struct file *file, struct address_space *mapping,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001455 loff_t pos, unsigned len, unsigned flags,
1456 struct page **pagep, void **fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001457{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001458 struct inode *inode = mapping->host;
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001459 int ret, needed_blocks;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001460 handle_t *handle;
1461 int retries = 0;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001462 struct page *page;
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001463 pgoff_t index;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001464 unsigned from, to;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001465
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001466 trace_ext4_write_begin(inode, pos, len, flags);
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001467 /*
1468 * Reserve one block more for addition to orphan list in case
1469 * we allocate blocks but write fails for some reason
1470 */
1471 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001472 index = pos >> PAGE_CACHE_SHIFT;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001473 from = pos & (PAGE_CACHE_SIZE - 1);
1474 to = from + len;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001475
1476retry:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001477 handle = ext4_journal_start(inode, needed_blocks);
1478 if (IS_ERR(handle)) {
1479 ret = PTR_ERR(handle);
1480 goto out;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001481 }
1482
Jan Karaebd36102009-02-22 21:09:59 -05001483 /* We cannot recurse into the filesystem as the transaction is already
1484 * started */
1485 flags |= AOP_FLAG_NOFS;
1486
Nick Piggin54566b22009-01-04 12:00:53 -08001487 page = grab_cache_page_write_begin(mapping, index, flags);
Jan Karacf108bc2008-07-11 19:27:31 -04001488 if (!page) {
1489 ext4_journal_stop(handle);
1490 ret = -ENOMEM;
1491 goto out;
1492 }
1493 *pagep = page;
1494
Nick Pigginbfc1af62007-10-16 01:25:05 -07001495 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
Jan Karaebd36102009-02-22 21:09:59 -05001496 ext4_get_block);
Nick Pigginbfc1af62007-10-16 01:25:05 -07001497
1498 if (!ret && ext4_should_journal_data(inode)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001499 ret = walk_page_buffers(handle, page_buffers(page),
1500 from, to, NULL, do_journal_get_write_access);
1501 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001502
1503 if (ret) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001504 unlock_page(page);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001505 page_cache_release(page);
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001506 /*
1507 * block_write_begin may have instantiated a few blocks
1508 * outside i_size. Trim these off again. Don't need
1509 * i_size_read because we hold i_mutex.
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001510 *
1511 * Add inode to orphan list in case we crash before
1512 * truncate finishes
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04001513 */
Jan Karaffacfa72009-07-13 16:22:22 -04001514 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001515 ext4_orphan_add(handle, inode);
1516
1517 ext4_journal_stop(handle);
1518 if (pos + len > inode->i_size) {
Jan Karaffacfa72009-07-13 16:22:22 -04001519 ext4_truncate(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001520 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001521 * If truncate failed early the inode might
Aneesh Kumar K.V1938a152009-06-05 01:00:26 -04001522 * still be on the orphan list; we need to
1523 * make sure the inode is removed from the
1524 * orphan list in that case.
1525 */
1526 if (inode->i_nlink)
1527 ext4_orphan_del(NULL, inode);
1528 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001529 }
1530
Mingming Cao617ba132006-10-11 01:20:53 -07001531 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001532 goto retry;
Andrew Morton7479d2b2007-04-01 23:49:44 -07001533out:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001534 return ret;
1535}
1536
Nick Pigginbfc1af62007-10-16 01:25:05 -07001537/* For write_end() in data=journal mode */
1538static int write_end_fn(handle_t *handle, struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001539{
1540 if (!buffer_mapped(bh) || buffer_freed(bh))
1541 return 0;
1542 set_buffer_uptodate(bh);
Frank Mayhar03901312009-01-07 00:06:22 -05001543 return ext4_handle_dirty_metadata(handle, NULL, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001544}
1545
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001546static int ext4_generic_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001547 struct address_space *mapping,
1548 loff_t pos, unsigned len, unsigned copied,
1549 struct page *page, void *fsdata)
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001550{
1551 int i_size_changed = 0;
1552 struct inode *inode = mapping->host;
1553 handle_t *handle = ext4_journal_current_handle();
1554
1555 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1556
1557 /*
1558 * No need to use i_size_read() here, the i_size
1559 * cannot change under us because we hold i_mutex.
1560 *
1561 * But it's important to update i_size while still holding page lock:
1562 * page writeout could otherwise come in and zero beyond i_size.
1563 */
1564 if (pos + copied > inode->i_size) {
1565 i_size_write(inode, pos + copied);
1566 i_size_changed = 1;
1567 }
1568
1569 if (pos + copied > EXT4_I(inode)->i_disksize) {
1570 /* We need to mark inode dirty even if
1571 * new_i_size is less that inode->i_size
1572 * bu greater than i_disksize.(hint delalloc)
1573 */
1574 ext4_update_i_disksize(inode, (pos + copied));
1575 i_size_changed = 1;
1576 }
1577 unlock_page(page);
1578 page_cache_release(page);
1579
1580 /*
1581 * Don't mark the inode dirty under page lock. First, it unnecessarily
1582 * makes the holding time of page lock longer. Second, it forces lock
1583 * ordering of page lock and transaction start for journaling
1584 * filesystems.
1585 */
1586 if (i_size_changed)
1587 ext4_mark_inode_dirty(handle, inode);
1588
1589 return copied;
1590}
1591
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001592/*
1593 * We need to pick up the new inode size which generic_commit_write gave us
1594 * `file' can be NULL - eg, when called from page_symlink().
1595 *
Mingming Cao617ba132006-10-11 01:20:53 -07001596 * ext4 never places buffers on inode->i_mapping->private_list. metadata
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001597 * buffers are managed internally.
1598 */
Nick Pigginbfc1af62007-10-16 01:25:05 -07001599static int ext4_ordered_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001600 struct address_space *mapping,
1601 loff_t pos, unsigned len, unsigned copied,
1602 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001603{
Mingming Cao617ba132006-10-11 01:20:53 -07001604 handle_t *handle = ext4_journal_current_handle();
Jan Karacf108bc2008-07-11 19:27:31 -04001605 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001606 int ret = 0, ret2;
1607
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001608 trace_ext4_ordered_write_end(inode, pos, len, copied);
Jan Kara678aaf42008-07-11 19:27:31 -04001609 ret = ext4_jbd2_file_inode(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001610
1611 if (ret == 0) {
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001612 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001613 page, fsdata);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001614 copied = ret2;
Jan Karaffacfa72009-07-13 16:22:22 -04001615 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001616 /* if we have allocated more blocks and copied
1617 * less. We will have blocks allocated outside
1618 * inode->i_size. So truncate them
1619 */
1620 ext4_orphan_add(handle, inode);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001621 if (ret2 < 0)
1622 ret = ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001623 }
Mingming Cao617ba132006-10-11 01:20:53 -07001624 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001625 if (!ret)
1626 ret = ret2;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001627
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001628 if (pos + len > inode->i_size) {
Jan Karaffacfa72009-07-13 16:22:22 -04001629 ext4_truncate(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001630 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001631 * If truncate failed early the inode might still be
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001632 * on the orphan list; we need to make sure the inode
1633 * is removed from the orphan list in that case.
1634 */
1635 if (inode->i_nlink)
1636 ext4_orphan_del(NULL, inode);
1637 }
1638
1639
Nick Pigginbfc1af62007-10-16 01:25:05 -07001640 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001641}
1642
Nick Pigginbfc1af62007-10-16 01:25:05 -07001643static int ext4_writeback_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001644 struct address_space *mapping,
1645 loff_t pos, unsigned len, unsigned copied,
1646 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001647{
Mingming Cao617ba132006-10-11 01:20:53 -07001648 handle_t *handle = ext4_journal_current_handle();
Jan Karacf108bc2008-07-11 19:27:31 -04001649 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001650 int ret = 0, ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001651
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001652 trace_ext4_writeback_write_end(inode, pos, len, copied);
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001653 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001654 page, fsdata);
Roel Kluinf8a87d82008-04-29 22:01:18 -04001655 copied = ret2;
Jan Karaffacfa72009-07-13 16:22:22 -04001656 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001657 /* if we have allocated more blocks and copied
1658 * less. We will have blocks allocated outside
1659 * inode->i_size. So truncate them
1660 */
1661 ext4_orphan_add(handle, inode);
1662
Roel Kluinf8a87d82008-04-29 22:01:18 -04001663 if (ret2 < 0)
1664 ret = ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001665
Mingming Cao617ba132006-10-11 01:20:53 -07001666 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001667 if (!ret)
1668 ret = ret2;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001669
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001670 if (pos + len > inode->i_size) {
Jan Karaffacfa72009-07-13 16:22:22 -04001671 ext4_truncate(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001672 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001673 * If truncate failed early the inode might still be
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001674 * on the orphan list; we need to make sure the inode
1675 * is removed from the orphan list in that case.
1676 */
1677 if (inode->i_nlink)
1678 ext4_orphan_del(NULL, inode);
1679 }
1680
Nick Pigginbfc1af62007-10-16 01:25:05 -07001681 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001682}
1683
Nick Pigginbfc1af62007-10-16 01:25:05 -07001684static int ext4_journalled_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001685 struct address_space *mapping,
1686 loff_t pos, unsigned len, unsigned copied,
1687 struct page *page, void *fsdata)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001688{
Mingming Cao617ba132006-10-11 01:20:53 -07001689 handle_t *handle = ext4_journal_current_handle();
Nick Pigginbfc1af62007-10-16 01:25:05 -07001690 struct inode *inode = mapping->host;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001691 int ret = 0, ret2;
1692 int partial = 0;
Nick Pigginbfc1af62007-10-16 01:25:05 -07001693 unsigned from, to;
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001694 loff_t new_i_size;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001695
Theodore Ts'o9bffad12009-06-17 11:48:11 -04001696 trace_ext4_journalled_write_end(inode, pos, len, copied);
Nick Pigginbfc1af62007-10-16 01:25:05 -07001697 from = pos & (PAGE_CACHE_SIZE - 1);
1698 to = from + len;
1699
1700 if (copied < len) {
1701 if (!PageUptodate(page))
1702 copied = 0;
1703 page_zero_new_buffers(page, from+copied, to);
1704 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001705
1706 ret = walk_page_buffers(handle, page_buffers(page), from,
Nick Pigginbfc1af62007-10-16 01:25:05 -07001707 to, &partial, write_end_fn);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001708 if (!partial)
1709 SetPageUptodate(page);
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001710 new_i_size = pos + copied;
1711 if (new_i_size > inode->i_size)
Nick Pigginbfc1af62007-10-16 01:25:05 -07001712 i_size_write(inode, pos+copied);
Mingming Cao617ba132006-10-11 01:20:53 -07001713 EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04001714 if (new_i_size > EXT4_I(inode)->i_disksize) {
1715 ext4_update_i_disksize(inode, new_i_size);
Mingming Cao617ba132006-10-11 01:20:53 -07001716 ret2 = ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001717 if (!ret)
1718 ret = ret2;
1719 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001720
Jan Karacf108bc2008-07-11 19:27:31 -04001721 unlock_page(page);
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001722 page_cache_release(page);
Jan Karaffacfa72009-07-13 16:22:22 -04001723 if (pos + len > inode->i_size && ext4_can_truncate(inode))
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001724 /* if we have allocated more blocks and copied
1725 * less. We will have blocks allocated outside
1726 * inode->i_size. So truncate them
1727 */
1728 ext4_orphan_add(handle, inode);
1729
Mingming Cao617ba132006-10-11 01:20:53 -07001730 ret2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001731 if (!ret)
1732 ret = ret2;
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001733 if (pos + len > inode->i_size) {
Jan Karaffacfa72009-07-13 16:22:22 -04001734 ext4_truncate(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001735 /*
Jan Karaffacfa72009-07-13 16:22:22 -04001736 * If truncate failed early the inode might still be
Aneesh Kumar K.Vf8514082009-06-05 00:56:49 -04001737 * on the orphan list; we need to make sure the inode
1738 * is removed from the orphan list in that case.
1739 */
1740 if (inode->i_nlink)
1741 ext4_orphan_del(NULL, inode);
1742 }
Nick Pigginbfc1af62007-10-16 01:25:05 -07001743
1744 return ret ? ret : copied;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001745}
Mingming Caod2a17632008-07-14 17:52:37 -04001746
1747static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
1748{
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001749 int retries = 0;
Mingming Cao60e58e02009-01-22 18:13:05 +01001750 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1751 unsigned long md_needed, mdblocks, total = 0;
Mingming Caod2a17632008-07-14 17:52:37 -04001752
1753 /*
1754 * recalculate the amount of metadata blocks to reserve
1755 * in order to allocate nrblocks
1756 * worse case is one extent per block
1757 */
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001758repeat:
Mingming Caod2a17632008-07-14 17:52:37 -04001759 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1760 total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks;
1761 mdblocks = ext4_calc_metadata_amount(inode, total);
1762 BUG_ON(mdblocks < EXT4_I(inode)->i_reserved_meta_blocks);
1763
1764 md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
1765 total = md_needed + nrblocks;
1766
Mingming Cao60e58e02009-01-22 18:13:05 +01001767 /*
1768 * Make quota reservation here to prevent quota overflow
1769 * later. Real quota accounting is done at pages writeout
1770 * time.
1771 */
1772 if (vfs_dq_reserve_block(inode, total)) {
1773 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1774 return -EDQUOT;
1775 }
1776
Aneesh Kumar K.Va30d5422008-10-09 10:56:23 -04001777 if (ext4_claim_free_blocks(sbi, total)) {
Mingming Caod2a17632008-07-14 17:52:37 -04001778 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04001779 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1780 yield();
1781 goto repeat;
1782 }
Mingming Cao60e58e02009-01-22 18:13:05 +01001783 vfs_dq_release_reservation_block(inode, total);
Mingming Caod2a17632008-07-14 17:52:37 -04001784 return -ENOSPC;
1785 }
Mingming Caod2a17632008-07-14 17:52:37 -04001786 EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
1787 EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
1788
1789 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1790 return 0; /* success */
1791}
1792
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001793static void ext4_da_release_space(struct inode *inode, int to_free)
Mingming Caod2a17632008-07-14 17:52:37 -04001794{
1795 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1796 int total, mdb, mdb_free, release;
1797
Mingming Caocd213222008-08-19 22:16:59 -04001798 if (!to_free)
1799 return; /* Nothing to release, exit */
1800
Mingming Caod2a17632008-07-14 17:52:37 -04001801 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Caocd213222008-08-19 22:16:59 -04001802
1803 if (!EXT4_I(inode)->i_reserved_data_blocks) {
1804 /*
1805 * if there is no reserved blocks, but we try to free some
1806 * then the counter is messed up somewhere.
1807 * but since this function is called from invalidate
1808 * page, it's harmless to return without any action
1809 */
1810 printk(KERN_INFO "ext4 delalloc try to release %d reserved "
1811 "blocks for inode %lu, but there is no reserved "
1812 "data blocks\n", to_free, inode->i_ino);
1813 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1814 return;
1815 }
1816
Mingming Caod2a17632008-07-14 17:52:37 -04001817 /* recalculate the number of metablocks still need to be reserved */
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001818 total = EXT4_I(inode)->i_reserved_data_blocks - to_free;
Mingming Caod2a17632008-07-14 17:52:37 -04001819 mdb = ext4_calc_metadata_amount(inode, total);
1820
1821 /* figure out how many metablocks to release */
1822 BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
1823 mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
1824
Mingming Caod2a17632008-07-14 17:52:37 -04001825 release = to_free + mdb_free;
1826
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04001827 /* update fs dirty blocks counter for truncate case */
1828 percpu_counter_sub(&sbi->s_dirtyblocks_counter, release);
Mingming Caod2a17632008-07-14 17:52:37 -04001829
1830 /* update per-inode reservations */
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001831 BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks);
1832 EXT4_I(inode)->i_reserved_data_blocks -= to_free;
Mingming Caod2a17632008-07-14 17:52:37 -04001833
1834 BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
1835 EXT4_I(inode)->i_reserved_meta_blocks = mdb;
Mingming Caod2a17632008-07-14 17:52:37 -04001836 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Mingming Cao60e58e02009-01-22 18:13:05 +01001837
1838 vfs_dq_release_reservation_block(inode, release);
Mingming Caod2a17632008-07-14 17:52:37 -04001839}
1840
1841static void ext4_da_page_release_reservation(struct page *page,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04001842 unsigned long offset)
Mingming Caod2a17632008-07-14 17:52:37 -04001843{
1844 int to_release = 0;
1845 struct buffer_head *head, *bh;
1846 unsigned int curr_off = 0;
1847
1848 head = page_buffers(page);
1849 bh = head;
1850 do {
1851 unsigned int next_off = curr_off + bh->b_size;
1852
1853 if ((offset <= curr_off) && (buffer_delay(bh))) {
1854 to_release++;
1855 clear_buffer_delay(bh);
1856 }
1857 curr_off = next_off;
1858 } while ((bh = bh->b_this_page) != head);
Aneesh Kumar K.V12219ae2008-07-17 16:12:08 -04001859 ext4_da_release_space(page->mapping->host, to_release);
Mingming Caod2a17632008-07-14 17:52:37 -04001860}
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001861
1862/*
Alex Tomas64769242008-07-11 19:27:31 -04001863 * Delayed allocation stuff
1864 */
1865
1866struct mpage_da_data {
1867 struct inode *inode;
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05001868 sector_t b_blocknr; /* start block number of extent */
1869 size_t b_size; /* size of extent */
1870 unsigned long b_state; /* state of the extent */
Alex Tomas64769242008-07-11 19:27:31 -04001871 unsigned long first_page, next_page; /* extent of pages */
Alex Tomas64769242008-07-11 19:27:31 -04001872 struct writeback_control *wbc;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001873 int io_done;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05001874 int pages_written;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04001875 int retval;
Alex Tomas64769242008-07-11 19:27:31 -04001876};
1877
1878/*
1879 * mpage_da_submit_io - walks through extent of pages and try to write
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001880 * them with writepage() call back
Alex Tomas64769242008-07-11 19:27:31 -04001881 *
1882 * @mpd->inode: inode
1883 * @mpd->first_page: first page of the extent
1884 * @mpd->next_page: page after the last page of the extent
Alex Tomas64769242008-07-11 19:27:31 -04001885 *
1886 * By the time mpage_da_submit_io() is called we expect all blocks
1887 * to be allocated. this may be wrong if allocation failed.
1888 *
1889 * As pages are already locked by write_cache_pages(), we can't use it
1890 */
1891static int mpage_da_submit_io(struct mpage_da_data *mpd)
1892{
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04001893 long pages_skipped;
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001894 struct pagevec pvec;
1895 unsigned long index, end;
1896 int ret = 0, err, nr_pages, i;
1897 struct inode *inode = mpd->inode;
1898 struct address_space *mapping = inode->i_mapping;
Alex Tomas64769242008-07-11 19:27:31 -04001899
1900 BUG_ON(mpd->next_page <= mpd->first_page);
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001901 /*
1902 * We need to start from the first_page to the next_page - 1
1903 * to make sure we also write the mapped dirty buffer_heads.
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05001904 * If we look at mpd->b_blocknr we would only be looking
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001905 * at the currently mapped buffer_heads.
1906 */
Alex Tomas64769242008-07-11 19:27:31 -04001907 index = mpd->first_page;
1908 end = mpd->next_page - 1;
1909
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001910 pagevec_init(&pvec, 0);
Alex Tomas64769242008-07-11 19:27:31 -04001911 while (index <= end) {
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001912 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
Alex Tomas64769242008-07-11 19:27:31 -04001913 if (nr_pages == 0)
1914 break;
1915 for (i = 0; i < nr_pages; i++) {
1916 struct page *page = pvec.pages[i];
1917
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05001918 index = page->index;
1919 if (index > end)
1920 break;
1921 index++;
1922
1923 BUG_ON(!PageLocked(page));
1924 BUG_ON(PageWriteback(page));
1925
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04001926 pages_skipped = mpd->wbc->pages_skipped;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001927 err = mapping->a_ops->writepage(page, mpd->wbc);
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04001928 if (!err && (pages_skipped == mpd->wbc->pages_skipped))
1929 /*
1930 * have successfully written the page
1931 * without skipping the same
1932 */
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001933 mpd->pages_written++;
Alex Tomas64769242008-07-11 19:27:31 -04001934 /*
1935 * In error case, we have to continue because
1936 * remaining pages are still locked
1937 * XXX: unlock and re-dirty them?
1938 */
1939 if (ret == 0)
1940 ret = err;
1941 }
1942 pagevec_release(&pvec);
1943 }
Alex Tomas64769242008-07-11 19:27:31 -04001944 return ret;
1945}
1946
1947/*
1948 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
1949 *
1950 * @mpd->inode - inode to walk through
1951 * @exbh->b_blocknr - first block on a disk
1952 * @exbh->b_size - amount of space in bytes
1953 * @logical - first logical block to start assignment with
1954 *
1955 * the function goes through all passed space and put actual disk
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04001956 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
Alex Tomas64769242008-07-11 19:27:31 -04001957 */
1958static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
1959 struct buffer_head *exbh)
1960{
1961 struct inode *inode = mpd->inode;
1962 struct address_space *mapping = inode->i_mapping;
1963 int blocks = exbh->b_size >> inode->i_blkbits;
1964 sector_t pblock = exbh->b_blocknr, cur_logical;
1965 struct buffer_head *head, *bh;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04001966 pgoff_t index, end;
Alex Tomas64769242008-07-11 19:27:31 -04001967 struct pagevec pvec;
1968 int nr_pages, i;
1969
1970 index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
1971 end = (logical + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
1972 cur_logical = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1973
1974 pagevec_init(&pvec, 0);
1975
1976 while (index <= end) {
1977 /* XXX: optimize tail */
1978 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1979 if (nr_pages == 0)
1980 break;
1981 for (i = 0; i < nr_pages; i++) {
1982 struct page *page = pvec.pages[i];
1983
1984 index = page->index;
1985 if (index > end)
1986 break;
1987 index++;
1988
1989 BUG_ON(!PageLocked(page));
1990 BUG_ON(PageWriteback(page));
1991 BUG_ON(!page_has_buffers(page));
1992
1993 bh = page_buffers(page);
1994 head = bh;
1995
1996 /* skip blocks out of the range */
1997 do {
1998 if (cur_logical >= logical)
1999 break;
2000 cur_logical++;
2001 } while ((bh = bh->b_this_page) != head);
2002
2003 do {
2004 if (cur_logical >= logical + blocks)
2005 break;
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002006
2007 if (buffer_delay(bh) ||
2008 buffer_unwritten(bh)) {
2009
2010 BUG_ON(bh->b_bdev != inode->i_sb->s_bdev);
2011
2012 if (buffer_delay(bh)) {
2013 clear_buffer_delay(bh);
2014 bh->b_blocknr = pblock;
2015 } else {
2016 /*
2017 * unwritten already should have
2018 * blocknr assigned. Verify that
2019 */
2020 clear_buffer_unwritten(bh);
2021 BUG_ON(bh->b_blocknr != pblock);
2022 }
2023
Mingming Cao61628a32008-07-11 19:27:31 -04002024 } else if (buffer_mapped(bh))
Alex Tomas64769242008-07-11 19:27:31 -04002025 BUG_ON(bh->b_blocknr != pblock);
Alex Tomas64769242008-07-11 19:27:31 -04002026
2027 cur_logical++;
2028 pblock++;
2029 } while ((bh = bh->b_this_page) != head);
2030 }
2031 pagevec_release(&pvec);
2032 }
2033}
2034
2035
2036/*
2037 * __unmap_underlying_blocks - just a helper function to unmap
2038 * set of blocks described by @bh
2039 */
2040static inline void __unmap_underlying_blocks(struct inode *inode,
2041 struct buffer_head *bh)
2042{
2043 struct block_device *bdev = inode->i_sb->s_bdev;
2044 int blocks, i;
2045
2046 blocks = bh->b_size >> inode->i_blkbits;
2047 for (i = 0; i < blocks; i++)
2048 unmap_underlying_metadata(bdev, bh->b_blocknr + i);
2049}
2050
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002051static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
2052 sector_t logical, long blk_cnt)
2053{
2054 int nr_pages, i;
2055 pgoff_t index, end;
2056 struct pagevec pvec;
2057 struct inode *inode = mpd->inode;
2058 struct address_space *mapping = inode->i_mapping;
2059
2060 index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
2061 end = (logical + blk_cnt - 1) >>
2062 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2063 while (index <= end) {
2064 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2065 if (nr_pages == 0)
2066 break;
2067 for (i = 0; i < nr_pages; i++) {
2068 struct page *page = pvec.pages[i];
2069 index = page->index;
2070 if (index > end)
2071 break;
2072 index++;
2073
2074 BUG_ON(!PageLocked(page));
2075 BUG_ON(PageWriteback(page));
2076 block_invalidatepage(page, 0);
2077 ClearPageUptodate(page);
2078 unlock_page(page);
2079 }
2080 }
2081 return;
2082}
2083
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002084static void ext4_print_free_blocks(struct inode *inode)
2085{
2086 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2087 printk(KERN_EMERG "Total free blocks count %lld\n",
2088 ext4_count_free_blocks(inode->i_sb));
2089 printk(KERN_EMERG "Free/Dirty block details\n");
2090 printk(KERN_EMERG "free_blocks=%lld\n",
Alexander Beregalov8f72fbd2008-10-29 17:13:08 -04002091 (long long)percpu_counter_sum(&sbi->s_freeblocks_counter));
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002092 printk(KERN_EMERG "dirty_blocks=%lld\n",
Alexander Beregalov8f72fbd2008-10-29 17:13:08 -04002093 (long long)percpu_counter_sum(&sbi->s_dirtyblocks_counter));
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002094 printk(KERN_EMERG "Block reservation details\n");
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002095 printk(KERN_EMERG "i_reserved_data_blocks=%u\n",
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002096 EXT4_I(inode)->i_reserved_data_blocks);
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002097 printk(KERN_EMERG "i_reserved_meta_blocks=%u\n",
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002098 EXT4_I(inode)->i_reserved_meta_blocks);
2099 return;
2100}
2101
Theodore Ts'ob920c752009-05-14 00:54:29 -04002102/*
Alex Tomas64769242008-07-11 19:27:31 -04002103 * mpage_da_map_blocks - go through given space
2104 *
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002105 * @mpd - bh describing space
Alex Tomas64769242008-07-11 19:27:31 -04002106 *
2107 * The function skips space we know is already mapped to disk blocks.
2108 *
Alex Tomas64769242008-07-11 19:27:31 -04002109 */
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002110static int mpage_da_map_blocks(struct mpage_da_data *mpd)
Alex Tomas64769242008-07-11 19:27:31 -04002111{
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002112 int err, blks, get_blocks_flags;
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04002113 struct buffer_head new;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002114 sector_t next = mpd->b_blocknr;
2115 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
2116 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
2117 handle_t *handle = NULL;
Alex Tomas64769242008-07-11 19:27:31 -04002118
2119 /*
2120 * We consider only non-mapped and non-allocated blocks
2121 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002122 if ((mpd->b_state & (1 << BH_Mapped)) &&
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002123 !(mpd->b_state & (1 << BH_Delay)) &&
2124 !(mpd->b_state & (1 << BH_Unwritten)))
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002125 return 0;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002126
2127 /*
2128 * If we didn't accumulate anything to write simply return
2129 */
2130 if (!mpd->b_size)
2131 return 0;
2132
2133 handle = ext4_journal_current_handle();
2134 BUG_ON(!handle);
2135
Aneesh Kumar K.V79ffab32009-05-13 15:13:42 -04002136 /*
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002137 * Call ext4_get_blocks() to allocate any delayed allocation
2138 * blocks, or to convert an uninitialized extent to be
2139 * initialized (in the case where we have written into
2140 * one or more preallocated blocks).
2141 *
2142 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2143 * indicate that we are on the delayed allocation path. This
2144 * affects functions in many different parts of the allocation
2145 * call path. This flag exists primarily because we don't
2146 * want to change *many* call functions, so ext4_get_blocks()
2147 * will set the magic i_delalloc_reserved_flag once the
2148 * inode's allocation semaphore is taken.
2149 *
2150 * If the blocks in questions were delalloc blocks, set
2151 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2152 * variables are updated after the blocks have been allocated.
Aneesh Kumar K.V79ffab32009-05-13 15:13:42 -04002153 */
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002154 new.b_state = 0;
2155 get_blocks_flags = (EXT4_GET_BLOCKS_CREATE |
2156 EXT4_GET_BLOCKS_DELALLOC_RESERVE);
2157 if (mpd->b_state & (1 << BH_Delay))
2158 get_blocks_flags |= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE;
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002159 blks = ext4_get_blocks(handle, mpd->inode, next, max_blocks,
Theodore Ts'o2ac3b6e2009-05-14 13:57:08 -04002160 &new, get_blocks_flags);
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002161 if (blks < 0) {
2162 err = blks;
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002163 /*
2164 * If get block returns with error we simply
2165 * return. Later writepage will redirty the page and
2166 * writepages will find the dirty page again
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002167 */
2168 if (err == -EAGAIN)
2169 return 0;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002170
2171 if (err == -ENOSPC &&
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002172 ext4_count_free_blocks(mpd->inode->i_sb)) {
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002173 mpd->retval = err;
2174 return 0;
2175 }
2176
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002177 /*
Theodore Ts'oed5bde02009-02-23 10:48:07 -05002178 * get block failure will cause us to loop in
2179 * writepages, because a_ops->writepage won't be able
2180 * to make progress. The page will be redirtied by
2181 * writepage and writepages will again try to write
2182 * the same.
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002183 */
2184 printk(KERN_EMERG "%s block allocation failed for inode %lu "
2185 "at logical offset %llu with max blocks "
2186 "%zd with error %d\n",
2187 __func__, mpd->inode->i_ino,
2188 (unsigned long long)next,
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002189 mpd->b_size >> mpd->inode->i_blkbits, err);
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002190 printk(KERN_EMERG "This should not happen.!! "
2191 "Data will be lost\n");
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04002192 if (err == -ENOSPC) {
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002193 ext4_print_free_blocks(mpd->inode);
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04002194 }
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002195 /* invalidate all the pages */
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002196 ext4_da_block_invalidatepages(mpd, next,
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002197 mpd->b_size >> mpd->inode->i_blkbits);
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002198 return err;
2199 }
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002200 BUG_ON(blks == 0);
2201
2202 new.b_size = (blks << mpd->inode->i_blkbits);
Alex Tomas64769242008-07-11 19:27:31 -04002203
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002204 if (buffer_new(&new))
2205 __unmap_underlying_blocks(mpd->inode, &new);
Alex Tomas64769242008-07-11 19:27:31 -04002206
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002207 /*
2208 * If blocks are delayed marked, we need to
2209 * put actual blocknr and drop delayed bit
2210 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002211 if ((mpd->b_state & (1 << BH_Delay)) ||
2212 (mpd->b_state & (1 << BH_Unwritten)))
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002213 mpage_put_bnr_to_bhs(mpd, next, &new);
2214
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002215 if (ext4_should_order_data(mpd->inode)) {
2216 err = ext4_jbd2_file_inode(handle, mpd->inode);
2217 if (err)
2218 return err;
2219 }
2220
2221 /*
Jan Kara03f5d8b2009-06-09 00:17:05 -04002222 * Update on-disk size along with block allocation.
Theodore Ts'o2fa3cdf2009-05-14 09:29:45 -04002223 */
2224 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
2225 if (disksize > i_size_read(mpd->inode))
2226 disksize = i_size_read(mpd->inode);
2227 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
2228 ext4_update_i_disksize(mpd->inode, disksize);
2229 return ext4_mark_inode_dirty(handle, mpd->inode);
2230 }
2231
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002232 return 0;
Alex Tomas64769242008-07-11 19:27:31 -04002233}
2234
Aneesh Kumar K.Vbf068ee2008-08-19 22:16:43 -04002235#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2236 (1 << BH_Delay) | (1 << BH_Unwritten))
Alex Tomas64769242008-07-11 19:27:31 -04002237
2238/*
2239 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2240 *
2241 * @mpd->lbh - extent of blocks
2242 * @logical - logical number of the block in the file
2243 * @bh - bh of the block (used to access block's state)
2244 *
2245 * the function is used to collect contig. blocks in same state
2246 */
2247static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002248 sector_t logical, size_t b_size,
2249 unsigned long b_state)
Alex Tomas64769242008-07-11 19:27:31 -04002250{
Alex Tomas64769242008-07-11 19:27:31 -04002251 sector_t next;
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002252 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
Alex Tomas64769242008-07-11 19:27:31 -04002253
Mingming Cao525f4ed2008-08-19 22:15:58 -04002254 /* check if thereserved journal credits might overflow */
2255 if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL)) {
2256 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
2257 /*
2258 * With non-extent format we are limited by the journal
2259 * credit available. Total credit needed to insert
2260 * nrblocks contiguous blocks is dependent on the
2261 * nrblocks. So limit nrblocks.
2262 */
2263 goto flush_it;
2264 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
2265 EXT4_MAX_TRANS_DATA) {
2266 /*
2267 * Adding the new buffer_head would make it cross the
2268 * allowed limit for which we have journal credit
2269 * reserved. So limit the new bh->b_size
2270 */
2271 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
2272 mpd->inode->i_blkbits;
2273 /* we will do mpage_da_submit_io in the next loop */
2274 }
2275 }
Alex Tomas64769242008-07-11 19:27:31 -04002276 /*
2277 * First block in the extent
2278 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002279 if (mpd->b_size == 0) {
2280 mpd->b_blocknr = logical;
2281 mpd->b_size = b_size;
2282 mpd->b_state = b_state & BH_FLAGS;
Alex Tomas64769242008-07-11 19:27:31 -04002283 return;
2284 }
2285
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002286 next = mpd->b_blocknr + nrblocks;
Alex Tomas64769242008-07-11 19:27:31 -04002287 /*
2288 * Can we merge the block to our big extent?
2289 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002290 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
2291 mpd->b_size += b_size;
Alex Tomas64769242008-07-11 19:27:31 -04002292 return;
2293 }
2294
Mingming Cao525f4ed2008-08-19 22:15:58 -04002295flush_it:
Alex Tomas64769242008-07-11 19:27:31 -04002296 /*
2297 * We couldn't merge the block to our extent, so we
2298 * need to flush current extent and start new one
2299 */
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002300 if (mpage_da_map_blocks(mpd) == 0)
2301 mpage_da_submit_io(mpd);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002302 mpd->io_done = 1;
2303 return;
Alex Tomas64769242008-07-11 19:27:31 -04002304}
2305
Aneesh Kumar K.Vc364b222009-06-14 17:57:10 -04002306static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002307{
Aneesh Kumar K.Vc364b222009-06-14 17:57:10 -04002308 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002309}
2310
Alex Tomas64769242008-07-11 19:27:31 -04002311/*
2312 * __mpage_da_writepage - finds extent of pages and blocks
2313 *
2314 * @page: page to consider
2315 * @wbc: not used, we just follow rules
2316 * @data: context
2317 *
2318 * The function finds extents of pages and scan them for all blocks.
2319 */
2320static int __mpage_da_writepage(struct page *page,
2321 struct writeback_control *wbc, void *data)
2322{
2323 struct mpage_da_data *mpd = data;
2324 struct inode *inode = mpd->inode;
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002325 struct buffer_head *bh, *head;
Alex Tomas64769242008-07-11 19:27:31 -04002326 sector_t logical;
2327
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002328 if (mpd->io_done) {
2329 /*
2330 * Rest of the page in the page_vec
2331 * redirty then and skip then. We will
2332 * try to to write them again after
2333 * starting a new transaction
2334 */
2335 redirty_page_for_writepage(wbc, page);
2336 unlock_page(page);
2337 return MPAGE_DA_EXTENT_TAIL;
2338 }
Alex Tomas64769242008-07-11 19:27:31 -04002339 /*
2340 * Can we merge this page to current extent?
2341 */
2342 if (mpd->next_page != page->index) {
2343 /*
2344 * Nope, we can't. So, we map non-allocated blocks
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002345 * and start IO on them using writepage()
Alex Tomas64769242008-07-11 19:27:31 -04002346 */
2347 if (mpd->next_page != mpd->first_page) {
Aneesh Kumar K.Vc4a0c462008-08-19 21:08:18 -04002348 if (mpage_da_map_blocks(mpd) == 0)
2349 mpage_da_submit_io(mpd);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002350 /*
2351 * skip rest of the page in the page_vec
2352 */
2353 mpd->io_done = 1;
2354 redirty_page_for_writepage(wbc, page);
2355 unlock_page(page);
2356 return MPAGE_DA_EXTENT_TAIL;
Alex Tomas64769242008-07-11 19:27:31 -04002357 }
2358
2359 /*
2360 * Start next extent of pages ...
2361 */
2362 mpd->first_page = page->index;
2363
2364 /*
2365 * ... and blocks
2366 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002367 mpd->b_size = 0;
2368 mpd->b_state = 0;
2369 mpd->b_blocknr = 0;
Alex Tomas64769242008-07-11 19:27:31 -04002370 }
2371
2372 mpd->next_page = page->index + 1;
2373 logical = (sector_t) page->index <<
2374 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2375
2376 if (!page_has_buffers(page)) {
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002377 mpage_add_bh_to_extent(mpd, logical, PAGE_CACHE_SIZE,
2378 (1 << BH_Dirty) | (1 << BH_Uptodate));
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002379 if (mpd->io_done)
2380 return MPAGE_DA_EXTENT_TAIL;
Alex Tomas64769242008-07-11 19:27:31 -04002381 } else {
2382 /*
2383 * Page with regular buffer heads, just add all dirty ones
2384 */
2385 head = page_buffers(page);
2386 bh = head;
2387 do {
2388 BUG_ON(buffer_locked(bh));
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002389 /*
2390 * We need to try to allocate
2391 * unmapped blocks in the same page.
2392 * Otherwise we won't make progress
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002393 * with the page in ext4_writepage
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002394 */
Aneesh Kumar K.Vc364b222009-06-14 17:57:10 -04002395 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002396 mpage_add_bh_to_extent(mpd, logical,
2397 bh->b_size,
2398 bh->b_state);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002399 if (mpd->io_done)
2400 return MPAGE_DA_EXTENT_TAIL;
Aneesh Kumar K.V791b7f02009-01-05 21:50:43 -05002401 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2402 /*
2403 * mapped dirty buffer. We need to update
2404 * the b_state because we look at
2405 * b_state in mpage_da_map_blocks. We don't
2406 * update b_size because if we find an
2407 * unmapped buffer_head later we need to
2408 * use the b_state flag of that buffer_head.
2409 */
Theodore Ts'o8dc207c2009-02-23 06:46:01 -05002410 if (mpd->b_size == 0)
2411 mpd->b_state = bh->b_state & BH_FLAGS;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002412 }
Alex Tomas64769242008-07-11 19:27:31 -04002413 logical++;
2414 } while ((bh = bh->b_this_page) != head);
2415 }
2416
2417 return 0;
2418}
2419
2420/*
Theodore Ts'ob920c752009-05-14 00:54:29 -04002421 * This is a special get_blocks_t callback which is used by
2422 * ext4_da_write_begin(). It will either return mapped block or
2423 * reserve space for a single block.
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002424 *
2425 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2426 * We also have b_blocknr = -1 and b_bdev initialized properly
2427 *
2428 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2429 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2430 * initialized properly.
Alex Tomas64769242008-07-11 19:27:31 -04002431 */
2432static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2433 struct buffer_head *bh_result, int create)
2434{
2435 int ret = 0;
Aneesh Kumar K.V33b98172009-05-12 14:40:37 -04002436 sector_t invalid_block = ~((sector_t) 0xffff);
2437
2438 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
2439 invalid_block = ~0;
Alex Tomas64769242008-07-11 19:27:31 -04002440
2441 BUG_ON(create == 0);
2442 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
2443
2444 /*
2445 * first, we need to know whether the block is allocated already
2446 * preallocated blocks are unmapped but should treated
2447 * the same as allocated blocks.
2448 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04002449 ret = ext4_get_blocks(NULL, inode, iblock, 1, bh_result, 0);
Mingming Caod2a17632008-07-14 17:52:37 -04002450 if ((ret == 0) && !buffer_delay(bh_result)) {
2451 /* the block isn't (pre)allocated yet, let's reserve space */
Alex Tomas64769242008-07-11 19:27:31 -04002452 /*
2453 * XXX: __block_prepare_write() unmaps passed block,
2454 * is it OK?
2455 */
Mingming Caod2a17632008-07-14 17:52:37 -04002456 ret = ext4_da_reserve_space(inode, 1);
2457 if (ret)
2458 /* not enough space to reserve */
2459 return ret;
2460
Aneesh Kumar K.V33b98172009-05-12 14:40:37 -04002461 map_bh(bh_result, inode->i_sb, invalid_block);
Alex Tomas64769242008-07-11 19:27:31 -04002462 set_buffer_new(bh_result);
2463 set_buffer_delay(bh_result);
2464 } else if (ret > 0) {
2465 bh_result->b_size = (ret << inode->i_blkbits);
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002466 if (buffer_unwritten(bh_result)) {
2467 /* A delayed write to unwritten bh should
2468 * be marked new and mapped. Mapped ensures
2469 * that we don't do get_block multiple times
2470 * when we write to the same offset and new
2471 * ensures that we do proper zero out for
2472 * partial write.
2473 */
Aneesh Kumar K.V9c1ee182009-05-13 18:36:58 -04002474 set_buffer_new(bh_result);
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04002475 set_buffer_mapped(bh_result);
2476 }
Alex Tomas64769242008-07-11 19:27:31 -04002477 ret = 0;
2478 }
2479
2480 return ret;
2481}
Mingming Cao61628a32008-07-11 19:27:31 -04002482
Theodore Ts'ob920c752009-05-14 00:54:29 -04002483/*
2484 * This function is used as a standard get_block_t calback function
2485 * when there is no desire to allocate any blocks. It is used as a
2486 * callback function for block_prepare_write(), nobh_writepage(), and
2487 * block_write_full_page(). These functions should only try to map a
2488 * single block at a time.
2489 *
2490 * Since this function doesn't do block allocations even if the caller
2491 * requests it by passing in create=1, it is critically important that
2492 * any caller checks to make sure that any buffer heads are returned
2493 * by this function are either all already mapped or marked for
2494 * delayed allocation before calling nobh_writepage() or
2495 * block_write_full_page(). Otherwise, b_blocknr could be left
2496 * unitialized, and the page write functions will be taken by
2497 * surprise.
2498 */
2499static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002500 struct buffer_head *bh_result, int create)
2501{
2502 int ret = 0;
2503 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
2504
Theodore Ts'oa2dc52b2009-05-12 13:51:29 -04002505 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
2506
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002507 /*
2508 * we don't want to do block allocation in writepage
2509 * so call get_block_wrap with create = 0
2510 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04002511 ret = ext4_get_blocks(NULL, inode, iblock, max_blocks, bh_result, 0);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002512 if (ret > 0) {
2513 bh_result->b_size = (ret << inode->i_blkbits);
2514 ret = 0;
2515 }
2516 return ret;
Mingming Cao61628a32008-07-11 19:27:31 -04002517}
2518
Aneesh Kumar K.V62e086b2009-06-14 17:59:34 -04002519static int bget_one(handle_t *handle, struct buffer_head *bh)
2520{
2521 get_bh(bh);
2522 return 0;
2523}
2524
2525static int bput_one(handle_t *handle, struct buffer_head *bh)
2526{
2527 put_bh(bh);
2528 return 0;
2529}
2530
2531static int __ext4_journalled_writepage(struct page *page,
2532 struct writeback_control *wbc,
2533 unsigned int len)
2534{
2535 struct address_space *mapping = page->mapping;
2536 struct inode *inode = mapping->host;
2537 struct buffer_head *page_bufs;
2538 handle_t *handle = NULL;
2539 int ret = 0;
2540 int err;
2541
2542 page_bufs = page_buffers(page);
2543 BUG_ON(!page_bufs);
2544 walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
2545 /* As soon as we unlock the page, it can go away, but we have
2546 * references to buffers so we are safe */
2547 unlock_page(page);
2548
2549 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
2550 if (IS_ERR(handle)) {
2551 ret = PTR_ERR(handle);
2552 goto out;
2553 }
2554
2555 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2556 do_journal_get_write_access);
2557
2558 err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2559 write_end_fn);
2560 if (ret == 0)
2561 ret = err;
2562 err = ext4_journal_stop(handle);
2563 if (!ret)
2564 ret = err;
2565
2566 walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
2567 EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
2568out:
2569 return ret;
2570}
2571
Mingming Cao61628a32008-07-11 19:27:31 -04002572/*
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002573 * Note that we don't need to start a transaction unless we're journaling data
2574 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2575 * need to file the inode to the transaction's list in ordered mode because if
2576 * we are writing back data added by write(), the inode is already there and if
2577 * we are writing back data modified via mmap(), noone guarantees in which
2578 * transaction the data will hit the disk. In case we are journaling data, we
2579 * cannot start transaction directly because transaction start ranks above page
2580 * lock so we have to do some magic.
2581 *
Theodore Ts'ob920c752009-05-14 00:54:29 -04002582 * This function can get called via...
2583 * - ext4_da_writepages after taking page lock (have journal handle)
2584 * - journal_submit_inode_data_buffers (no journal handle)
2585 * - shrink_page_list via pdflush (no journal handle)
2586 * - grab_page_cache when doing write_begin (have journal handle)
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002587 *
2588 * We don't do any block allocation in this function. If we have page with
2589 * multiple blocks we need to write those buffer_heads that are mapped. This
2590 * is important for mmaped based write. So if we do with blocksize 1K
2591 * truncate(f, 1024);
2592 * a = mmap(f, 0, 4096);
2593 * a[0] = 'a';
2594 * truncate(f, 4096);
2595 * we have in the page first buffer_head mapped via page_mkwrite call back
2596 * but other bufer_heads would be unmapped but dirty(dirty done via the
2597 * do_wp_page). So writepage should write the first block. If we modify
2598 * the mmap area beyond 1024 we will again get a page_fault and the
2599 * page_mkwrite callback will do the block allocation and mark the
2600 * buffer_heads mapped.
2601 *
2602 * We redirty the page if we have any buffer_heads that is either delay or
2603 * unwritten in the page.
2604 *
2605 * We can get recursively called as show below.
2606 *
2607 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2608 * ext4_writepage()
2609 *
2610 * But since we don't do any block allocation we should not deadlock.
2611 * Page also have the dirty flag cleared so we don't get recurive page_lock.
Mingming Cao61628a32008-07-11 19:27:31 -04002612 */
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002613static int ext4_writepage(struct page *page,
Aneesh Kumar K.V62e086b2009-06-14 17:59:34 -04002614 struct writeback_control *wbc)
Alex Tomas64769242008-07-11 19:27:31 -04002615{
Alex Tomas64769242008-07-11 19:27:31 -04002616 int ret = 0;
Mingming Cao61628a32008-07-11 19:27:31 -04002617 loff_t size;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002618 unsigned int len;
Mingming Cao61628a32008-07-11 19:27:31 -04002619 struct buffer_head *page_bufs;
2620 struct inode *inode = page->mapping->host;
Alex Tomas64769242008-07-11 19:27:31 -04002621
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002622 trace_ext4_writepage(inode, page);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002623 size = i_size_read(inode);
2624 if (page->index == size >> PAGE_CACHE_SHIFT)
2625 len = size & ~PAGE_CACHE_MASK;
2626 else
2627 len = PAGE_CACHE_SIZE;
Alex Tomas64769242008-07-11 19:27:31 -04002628
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002629 if (page_has_buffers(page)) {
Mingming Cao61628a32008-07-11 19:27:31 -04002630 page_bufs = page_buffers(page);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002631 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
Aneesh Kumar K.Vc364b222009-06-14 17:57:10 -04002632 ext4_bh_delay_or_unwritten)) {
Mingming Cao61628a32008-07-11 19:27:31 -04002633 /*
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002634 * We don't want to do block allocation
2635 * So redirty the page and return
Aneesh Kumar K.Vcd1aac32008-07-11 19:27:31 -04002636 * We may reach here when we do a journal commit
2637 * via journal_submit_inode_data_buffers.
2638 * If we don't have mapping block we just ignore
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002639 * them. We can also reach here via shrink_page_list
2640 */
2641 redirty_page_for_writepage(wbc, page);
2642 unlock_page(page);
2643 return 0;
2644 }
2645 } else {
2646 /*
2647 * The test for page_has_buffers() is subtle:
2648 * We know the page is dirty but it lost buffers. That means
2649 * that at some moment in time after write_begin()/write_end()
2650 * has been called all buffers have been clean and thus they
2651 * must have been written at least once. So they are all
2652 * mapped and we can happily proceed with mapping them
2653 * and writing the page.
2654 *
2655 * Try to initialize the buffer_heads and check whether
2656 * all are mapped and non delay. We don't want to
2657 * do block allocation here.
2658 */
Aneesh Kumar K.Vb767e782009-06-04 08:06:06 -04002659 ret = block_prepare_write(page, 0, len,
Theodore Ts'ob920c752009-05-14 00:54:29 -04002660 noalloc_get_block_write);
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002661 if (!ret) {
2662 page_bufs = page_buffers(page);
2663 /* check whether all are mapped and non delay */
2664 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
Aneesh Kumar K.Vc364b222009-06-14 17:57:10 -04002665 ext4_bh_delay_or_unwritten)) {
Aneesh Kumar K.Vf0e6c982008-07-11 19:27:31 -04002666 redirty_page_for_writepage(wbc, page);
2667 unlock_page(page);
2668 return 0;
2669 }
2670 } else {
2671 /*
2672 * We can't do block allocation here
2673 * so just redity the page and unlock
2674 * and return
Mingming Cao61628a32008-07-11 19:27:31 -04002675 */
Mingming Cao61628a32008-07-11 19:27:31 -04002676 redirty_page_for_writepage(wbc, page);
2677 unlock_page(page);
2678 return 0;
2679 }
Aneesh Kumar K.Ved9b3e32008-11-07 09:06:45 -05002680 /* now mark the buffer_heads as dirty and uptodate */
Aneesh Kumar K.Vb767e782009-06-04 08:06:06 -04002681 block_commit_write(page, 0, len);
Alex Tomas64769242008-07-11 19:27:31 -04002682 }
2683
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04002684 if (PageChecked(page) && ext4_should_journal_data(inode)) {
2685 /*
2686 * It's mmapped pagecache. Add buffers and journal it. There
2687 * doesn't seem much point in redirtying the page here.
2688 */
2689 ClearPageChecked(page);
2690 return __ext4_journalled_writepage(page, wbc, len);
2691 }
2692
Alex Tomas64769242008-07-11 19:27:31 -04002693 if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
Theodore Ts'ob920c752009-05-14 00:54:29 -04002694 ret = nobh_writepage(page, noalloc_get_block_write, wbc);
Alex Tomas64769242008-07-11 19:27:31 -04002695 else
Theodore Ts'ob920c752009-05-14 00:54:29 -04002696 ret = block_write_full_page(page, noalloc_get_block_write,
2697 wbc);
Alex Tomas64769242008-07-11 19:27:31 -04002698
Alex Tomas64769242008-07-11 19:27:31 -04002699 return ret;
2700}
2701
Mingming Cao61628a32008-07-11 19:27:31 -04002702/*
Mingming Cao525f4ed2008-08-19 22:15:58 -04002703 * This is called via ext4_da_writepages() to
2704 * calulate the total number of credits to reserve to fit
2705 * a single extent allocation into a single transaction,
2706 * ext4_da_writpeages() will loop calling this before
2707 * the block allocation.
Mingming Cao61628a32008-07-11 19:27:31 -04002708 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04002709
2710static int ext4_da_writepages_trans_blocks(struct inode *inode)
2711{
2712 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2713
2714 /*
2715 * With non-extent format the journal credit needed to
2716 * insert nrblocks contiguous block is dependent on
2717 * number of contiguous block. So we will limit
2718 * number of contiguous block to a sane value
2719 */
2720 if (!(inode->i_flags & EXT4_EXTENTS_FL) &&
2721 (max_blocks > EXT4_MAX_TRANS_DATA))
2722 max_blocks = EXT4_MAX_TRANS_DATA;
2723
2724 return ext4_chunk_trans_blocks(inode, max_blocks);
2725}
Mingming Cao61628a32008-07-11 19:27:31 -04002726
Alex Tomas64769242008-07-11 19:27:31 -04002727static int ext4_da_writepages(struct address_space *mapping,
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002728 struct writeback_control *wbc)
Alex Tomas64769242008-07-11 19:27:31 -04002729{
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002730 pgoff_t index;
2731 int range_whole = 0;
Mingming Cao61628a32008-07-11 19:27:31 -04002732 handle_t *handle = NULL;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002733 struct mpage_da_data mpd;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002734 struct inode *inode = mapping->host;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002735 int no_nrwrite_index_update;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002736 int pages_written = 0;
2737 long pages_skipped;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002738 int range_cyclic, cycled = 1, io_done = 0;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002739 int needed_blocks, ret = 0, nr_to_writebump = 0;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002740 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
Mingming Cao61628a32008-07-11 19:27:31 -04002741
Theodore Ts'o9bffad12009-06-17 11:48:11 -04002742 trace_ext4_da_writepages(inode, wbc);
Theodore Ts'oba80b102009-01-03 20:03:21 -05002743
Mingming Cao61628a32008-07-11 19:27:31 -04002744 /*
2745 * No pages to write? This is mainly a kludge to avoid starting
2746 * a transaction for special inodes like journal inode on last iput()
2747 * because that could violate lock ordering on umount
2748 */
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002749 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
Mingming Cao61628a32008-07-11 19:27:31 -04002750 return 0;
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002751
2752 /*
2753 * If the filesystem has aborted, it is read-only, so return
2754 * right away instead of dumping stack traces later on that
2755 * will obscure the real source of the problem. We test
Theodore Ts'o4ab2f152009-06-13 10:09:36 -04002756 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002757 * the latter could be true if the filesystem is mounted
2758 * read-only, and in that case, ext4_da_writepages should
2759 * *never* be called, so if that ever happens, we would want
2760 * the stack trace.
2761 */
Theodore Ts'o4ab2f152009-06-13 10:09:36 -04002762 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002763 return -EROFS;
2764
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04002765 /*
2766 * Make sure nr_to_write is >= sbi->s_mb_stream_request
2767 * This make sure small files blocks are allocated in
2768 * single attempt. This ensure that small files
2769 * get less fragmented.
2770 */
2771 if (wbc->nr_to_write < sbi->s_mb_stream_request) {
2772 nr_to_writebump = sbi->s_mb_stream_request - wbc->nr_to_write;
2773 wbc->nr_to_write = sbi->s_mb_stream_request;
2774 }
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002775 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2776 range_whole = 1;
Mingming Cao61628a32008-07-11 19:27:31 -04002777
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002778 range_cyclic = wbc->range_cyclic;
2779 if (wbc->range_cyclic) {
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002780 index = mapping->writeback_index;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002781 if (index)
2782 cycled = 0;
2783 wbc->range_start = index << PAGE_CACHE_SHIFT;
2784 wbc->range_end = LLONG_MAX;
2785 wbc->range_cyclic = 0;
2786 } else
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002787 index = wbc->range_start >> PAGE_CACHE_SHIFT;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002788
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002789 mpd.wbc = wbc;
2790 mpd.inode = mapping->host;
2791
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002792 /*
2793 * we don't want write_cache_pages to update
2794 * nr_to_write and writeback_index
2795 */
2796 no_nrwrite_index_update = wbc->no_nrwrite_index_update;
2797 wbc->no_nrwrite_index_update = 1;
2798 pages_skipped = wbc->pages_skipped;
2799
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002800retry:
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002801 while (!ret && wbc->nr_to_write > 0) {
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002802
2803 /*
2804 * we insert one extent at a time. So we need
2805 * credit needed for single extent allocation.
2806 * journalled mode is currently not supported
2807 * by delalloc
2808 */
2809 BUG_ON(ext4_should_journal_data(inode));
Mingming Cao525f4ed2008-08-19 22:15:58 -04002810 needed_blocks = ext4_da_writepages_trans_blocks(inode);
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002811
Mingming Cao61628a32008-07-11 19:27:31 -04002812 /* start a new transaction*/
2813 handle = ext4_journal_start(inode, needed_blocks);
2814 if (IS_ERR(handle)) {
2815 ret = PTR_ERR(handle);
Theodore Ts'o2a21e372008-11-05 09:22:24 -05002816 printk(KERN_CRIT "%s: jbd2_start: "
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002817 "%ld pages, ino %lu; err %d\n", __func__,
2818 wbc->nr_to_write, inode->i_ino, ret);
2819 dump_stack();
Mingming Cao61628a32008-07-11 19:27:31 -04002820 goto out_writepages;
2821 }
Theodore Ts'of63e6002009-02-23 16:42:39 -05002822
2823 /*
2824 * Now call __mpage_da_writepage to find the next
2825 * contiguous region of logical blocks that need
2826 * blocks to be allocated by ext4. We don't actually
2827 * submit the blocks for I/O here, even though
2828 * write_cache_pages thinks it will, and will set the
2829 * pages as clean for write before calling
2830 * __mpage_da_writepage().
2831 */
2832 mpd.b_size = 0;
2833 mpd.b_state = 0;
2834 mpd.b_blocknr = 0;
2835 mpd.first_page = 0;
2836 mpd.next_page = 0;
2837 mpd.io_done = 0;
2838 mpd.pages_written = 0;
2839 mpd.retval = 0;
2840 ret = write_cache_pages(mapping, wbc, __mpage_da_writepage,
2841 &mpd);
2842 /*
2843 * If we have a contigous extent of pages and we
2844 * haven't done the I/O yet, map the blocks and submit
2845 * them for I/O.
2846 */
2847 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
2848 if (mpage_da_map_blocks(&mpd) == 0)
2849 mpage_da_submit_io(&mpd);
2850 mpd.io_done = 1;
2851 ret = MPAGE_DA_EXTENT_TAIL;
2852 }
2853 wbc->nr_to_write -= mpd.pages_written;
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002854
Mingming Cao61628a32008-07-11 19:27:31 -04002855 ext4_journal_stop(handle);
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002856
Eric Sandeen8f64b322009-02-26 00:57:35 -05002857 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002858 /* commit the transaction which would
2859 * free blocks released in the transaction
2860 * and try again
2861 */
Aneesh Kumar K.Vdf222912008-09-08 23:05:34 -04002862 jbd2_journal_force_commit_nested(sbi->s_journal);
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002863 wbc->pages_skipped = pages_skipped;
2864 ret = 0;
2865 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002866 /*
2867 * got one extent now try with
2868 * rest of the pages
2869 */
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002870 pages_written += mpd.pages_written;
2871 wbc->pages_skipped = pages_skipped;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002872 ret = 0;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002873 io_done = 1;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002874 } else if (wbc->nr_to_write)
Mingming Cao61628a32008-07-11 19:27:31 -04002875 /*
2876 * There is no more writeout needed
2877 * or we requested for a noblocking writeout
2878 * and we found the device congested
2879 */
Mingming Cao61628a32008-07-11 19:27:31 -04002880 break;
Mingming Cao61628a32008-07-11 19:27:31 -04002881 }
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002882 if (!io_done && !cycled) {
2883 cycled = 1;
2884 index = 0;
2885 wbc->range_start = index << PAGE_CACHE_SHIFT;
2886 wbc->range_end = mapping->writeback_index - 1;
2887 goto retry;
2888 }
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002889 if (pages_skipped != wbc->pages_skipped)
2890 printk(KERN_EMERG "This should not happen leaving %s "
2891 "with nr_to_write = %ld ret = %d\n",
2892 __func__, wbc->nr_to_write, ret);
Mingming Cao61628a32008-07-11 19:27:31 -04002893
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002894 /* Update index */
2895 index += pages_written;
Aneesh Kumar K.V2acf2c22009-02-14 10:42:58 -05002896 wbc->range_cyclic = range_cyclic;
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002897 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2898 /*
2899 * set the writeback_index so that range_cyclic
2900 * mode will write it back later
2901 */
2902 mapping->writeback_index = index;
Aneesh Kumar K.Va1d6cc52008-08-19 21:55:02 -04002903
Mingming Cao61628a32008-07-11 19:27:31 -04002904out_writepages:
Aneesh Kumar K.V22208de2008-10-16 10:10:36 -04002905 if (!no_nrwrite_index_update)
2906 wbc->no_nrwrite_index_update = 0;
2907 wbc->nr_to_write -= nr_to_writebump;
Theodore Ts'o9bffad12009-06-17 11:48:11 -04002908 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
Mingming Cao61628a32008-07-11 19:27:31 -04002909 return ret;
Alex Tomas64769242008-07-11 19:27:31 -04002910}
2911
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04002912#define FALL_BACK_TO_NONDELALLOC 1
2913static int ext4_nonda_switch(struct super_block *sb)
2914{
2915 s64 free_blocks, dirty_blocks;
2916 struct ext4_sb_info *sbi = EXT4_SB(sb);
2917
2918 /*
2919 * switch to non delalloc mode if we are running low
2920 * on free block. The free block accounting via percpu
Eric Dumazet179f7eb2009-01-06 14:41:04 -08002921 * counters can get slightly wrong with percpu_counter_batch getting
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04002922 * accumulated on each CPU without updating global counters
2923 * Delalloc need an accurate free block accounting. So switch
2924 * to non delalloc when we are near to error range.
2925 */
2926 free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
2927 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter);
2928 if (2 * free_blocks < 3 * dirty_blocks ||
2929 free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) {
2930 /*
2931 * free block count is less that 150% of dirty blocks
2932 * or free blocks is less that watermark
2933 */
2934 return 1;
2935 }
2936 return 0;
2937}
2938
Alex Tomas64769242008-07-11 19:27:31 -04002939static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04002940 loff_t pos, unsigned len, unsigned flags,
2941 struct page **pagep, void **fsdata)
Alex Tomas64769242008-07-11 19:27:31 -04002942{
Mingming Caod2a17632008-07-14 17:52:37 -04002943 int ret, retries = 0;
Alex Tomas64769242008-07-11 19:27:31 -04002944 struct page *page;
2945 pgoff_t index;
2946 unsigned from, to;
2947 struct inode *inode = mapping->host;
2948 handle_t *handle;
2949
2950 index = pos >> PAGE_CACHE_SHIFT;
2951 from = pos & (PAGE_CACHE_SIZE - 1);
2952 to = from + len;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04002953
2954 if (ext4_nonda_switch(inode->i_sb)) {
2955 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2956 return ext4_write_begin(file, mapping, pos,
2957 len, flags, pagep, fsdata);
2958 }
2959 *fsdata = (void *)0;
Theodore Ts'o9bffad12009-06-17 11:48:11 -04002960 trace_ext4_da_write_begin(inode, pos, len, flags);
Mingming Caod2a17632008-07-14 17:52:37 -04002961retry:
Alex Tomas64769242008-07-11 19:27:31 -04002962 /*
2963 * With delayed allocation, we don't log the i_disksize update
2964 * if there is delayed block allocation. But we still need
2965 * to journalling the i_disksize update if writes to the end
2966 * of file which has an already mapped buffer.
2967 */
2968 handle = ext4_journal_start(inode, 1);
2969 if (IS_ERR(handle)) {
2970 ret = PTR_ERR(handle);
2971 goto out;
2972 }
Jan Karaebd36102009-02-22 21:09:59 -05002973 /* We cannot recurse into the filesystem as the transaction is already
2974 * started */
2975 flags |= AOP_FLAG_NOFS;
Alex Tomas64769242008-07-11 19:27:31 -04002976
Nick Piggin54566b22009-01-04 12:00:53 -08002977 page = grab_cache_page_write_begin(mapping, index, flags);
Eric Sandeend5a0d4f2008-08-02 18:51:06 -04002978 if (!page) {
2979 ext4_journal_stop(handle);
2980 ret = -ENOMEM;
2981 goto out;
2982 }
Alex Tomas64769242008-07-11 19:27:31 -04002983 *pagep = page;
2984
2985 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
Theodore Ts'ob920c752009-05-14 00:54:29 -04002986 ext4_da_get_block_prep);
Alex Tomas64769242008-07-11 19:27:31 -04002987 if (ret < 0) {
2988 unlock_page(page);
2989 ext4_journal_stop(handle);
2990 page_cache_release(page);
Aneesh Kumar K.Vae4d5372008-09-13 13:10:25 -04002991 /*
2992 * block_write_begin may have instantiated a few blocks
2993 * outside i_size. Trim these off again. Don't need
2994 * i_size_read because we hold i_mutex.
2995 */
2996 if (pos + len > inode->i_size)
Jan Karaffacfa72009-07-13 16:22:22 -04002997 ext4_truncate(inode);
Alex Tomas64769242008-07-11 19:27:31 -04002998 }
2999
Mingming Caod2a17632008-07-14 17:52:37 -04003000 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
3001 goto retry;
Alex Tomas64769242008-07-11 19:27:31 -04003002out:
3003 return ret;
3004}
3005
Mingming Cao632eaea2008-07-11 19:27:31 -04003006/*
3007 * Check if we should update i_disksize
3008 * when write to the end of file but not require block allocation
3009 */
3010static int ext4_da_should_update_i_disksize(struct page *page,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003011 unsigned long offset)
Mingming Cao632eaea2008-07-11 19:27:31 -04003012{
3013 struct buffer_head *bh;
3014 struct inode *inode = page->mapping->host;
3015 unsigned int idx;
3016 int i;
3017
3018 bh = page_buffers(page);
3019 idx = offset >> inode->i_blkbits;
3020
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003021 for (i = 0; i < idx; i++)
Mingming Cao632eaea2008-07-11 19:27:31 -04003022 bh = bh->b_this_page;
3023
Aneesh Kumar K.V29fa89d2009-05-12 16:30:27 -04003024 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
Mingming Cao632eaea2008-07-11 19:27:31 -04003025 return 0;
3026 return 1;
3027}
3028
Alex Tomas64769242008-07-11 19:27:31 -04003029static int ext4_da_write_end(struct file *file,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003030 struct address_space *mapping,
3031 loff_t pos, unsigned len, unsigned copied,
3032 struct page *page, void *fsdata)
Alex Tomas64769242008-07-11 19:27:31 -04003033{
3034 struct inode *inode = mapping->host;
3035 int ret = 0, ret2;
3036 handle_t *handle = ext4_journal_current_handle();
3037 loff_t new_i_size;
Mingming Cao632eaea2008-07-11 19:27:31 -04003038 unsigned long start, end;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04003039 int write_mode = (int)(unsigned long)fsdata;
3040
3041 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
3042 if (ext4_should_order_data(inode)) {
3043 return ext4_ordered_write_end(file, mapping, pos,
3044 len, copied, page, fsdata);
3045 } else if (ext4_should_writeback_data(inode)) {
3046 return ext4_writeback_write_end(file, mapping, pos,
3047 len, copied, page, fsdata);
3048 } else {
3049 BUG();
3050 }
3051 }
Mingming Cao632eaea2008-07-11 19:27:31 -04003052
Theodore Ts'o9bffad12009-06-17 11:48:11 -04003053 trace_ext4_da_write_end(inode, pos, len, copied);
Mingming Cao632eaea2008-07-11 19:27:31 -04003054 start = pos & (PAGE_CACHE_SIZE - 1);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003055 end = start + copied - 1;
Alex Tomas64769242008-07-11 19:27:31 -04003056
3057 /*
3058 * generic_write_end() will run mark_inode_dirty() if i_size
3059 * changes. So let's piggyback the i_disksize mark_inode_dirty
3060 * into that.
3061 */
3062
3063 new_i_size = pos + copied;
Mingming Cao632eaea2008-07-11 19:27:31 -04003064 if (new_i_size > EXT4_I(inode)->i_disksize) {
3065 if (ext4_da_should_update_i_disksize(page, end)) {
3066 down_write(&EXT4_I(inode)->i_data_sem);
3067 if (new_i_size > EXT4_I(inode)->i_disksize) {
3068 /*
3069 * Updating i_disksize when extending file
3070 * without needing block allocation
3071 */
3072 if (ext4_should_order_data(inode))
3073 ret = ext4_jbd2_file_inode(handle,
3074 inode);
Alex Tomas64769242008-07-11 19:27:31 -04003075
Mingming Cao632eaea2008-07-11 19:27:31 -04003076 EXT4_I(inode)->i_disksize = new_i_size;
3077 }
3078 up_write(&EXT4_I(inode)->i_data_sem);
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04003079 /* We need to mark inode dirty even if
3080 * new_i_size is less that inode->i_size
3081 * bu greater than i_disksize.(hint delalloc)
3082 */
3083 ext4_mark_inode_dirty(handle, inode);
Alex Tomas64769242008-07-11 19:27:31 -04003084 }
Mingming Cao632eaea2008-07-11 19:27:31 -04003085 }
Alex Tomas64769242008-07-11 19:27:31 -04003086 ret2 = generic_write_end(file, mapping, pos, len, copied,
3087 page, fsdata);
3088 copied = ret2;
3089 if (ret2 < 0)
3090 ret = ret2;
3091 ret2 = ext4_journal_stop(handle);
3092 if (!ret)
3093 ret = ret2;
3094
3095 return ret ? ret : copied;
3096}
3097
3098static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
3099{
Alex Tomas64769242008-07-11 19:27:31 -04003100 /*
3101 * Drop reserved blocks
3102 */
3103 BUG_ON(!PageLocked(page));
3104 if (!page_has_buffers(page))
3105 goto out;
3106
Mingming Caod2a17632008-07-14 17:52:37 -04003107 ext4_da_page_release_reservation(page, offset);
Alex Tomas64769242008-07-11 19:27:31 -04003108
3109out:
3110 ext4_invalidatepage(page, offset);
3111
3112 return;
3113}
3114
Theodore Ts'occd25062009-02-26 01:04:07 -05003115/*
3116 * Force all delayed allocation blocks to be allocated for a given inode.
3117 */
3118int ext4_alloc_da_blocks(struct inode *inode)
3119{
3120 if (!EXT4_I(inode)->i_reserved_data_blocks &&
3121 !EXT4_I(inode)->i_reserved_meta_blocks)
3122 return 0;
3123
3124 /*
3125 * We do something simple for now. The filemap_flush() will
3126 * also start triggering a write of the data blocks, which is
3127 * not strictly speaking necessary (and for users of
3128 * laptop_mode, not even desirable). However, to do otherwise
3129 * would require replicating code paths in:
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003130 *
Theodore Ts'occd25062009-02-26 01:04:07 -05003131 * ext4_da_writepages() ->
3132 * write_cache_pages() ---> (via passed in callback function)
3133 * __mpage_da_writepage() -->
3134 * mpage_add_bh_to_extent()
3135 * mpage_da_map_blocks()
3136 *
3137 * The problem is that write_cache_pages(), located in
3138 * mm/page-writeback.c, marks pages clean in preparation for
3139 * doing I/O, which is not desirable if we're not planning on
3140 * doing I/O at all.
3141 *
3142 * We could call write_cache_pages(), and then redirty all of
3143 * the pages by calling redirty_page_for_writeback() but that
3144 * would be ugly in the extreme. So instead we would need to
3145 * replicate parts of the code in the above functions,
3146 * simplifying them becuase we wouldn't actually intend to
3147 * write out the pages, but rather only collect contiguous
3148 * logical block extents, call the multi-block allocator, and
3149 * then update the buffer heads with the block allocations.
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003150 *
Theodore Ts'occd25062009-02-26 01:04:07 -05003151 * For now, though, we'll cheat by calling filemap_flush(),
3152 * which will map the blocks, and start the I/O, but not
3153 * actually wait for the I/O to complete.
3154 */
3155 return filemap_flush(inode->i_mapping);
3156}
Alex Tomas64769242008-07-11 19:27:31 -04003157
3158/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003159 * bmap() is special. It gets used by applications such as lilo and by
3160 * the swapper to find the on-disk block of a specific piece of data.
3161 *
3162 * Naturally, this is dangerous if the block concerned is still in the
Mingming Cao617ba132006-10-11 01:20:53 -07003163 * journal. If somebody makes a swapfile on an ext4 data-journaling
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003164 * filesystem and enables swap, then they may get a nasty shock when the
3165 * data getting swapped to that swapfile suddenly gets overwritten by
3166 * the original zero's written out previously to the journal and
3167 * awaiting writeback in the kernel's buffer cache.
3168 *
3169 * So, if we see any bmap calls here on a modified, data-journaled file,
3170 * take extra steps to flush any blocks which might be in the cache.
3171 */
Mingming Cao617ba132006-10-11 01:20:53 -07003172static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003173{
3174 struct inode *inode = mapping->host;
3175 journal_t *journal;
3176 int err;
3177
Alex Tomas64769242008-07-11 19:27:31 -04003178 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3179 test_opt(inode->i_sb, DELALLOC)) {
3180 /*
3181 * With delalloc we want to sync the file
3182 * so that we can make sure we allocate
3183 * blocks for file
3184 */
3185 filemap_write_and_wait(mapping);
3186 }
3187
Frank Mayhar03901312009-01-07 00:06:22 -05003188 if (EXT4_JOURNAL(inode) && EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003189 /*
3190 * This is a REALLY heavyweight approach, but the use of
3191 * bmap on dirty files is expected to be extremely rare:
3192 * only if we run lilo or swapon on a freshly made file
3193 * do we expect this to happen.
3194 *
3195 * (bmap requires CAP_SYS_RAWIO so this does not
3196 * represent an unprivileged user DOS attack --- we'd be
3197 * in trouble if mortal users could trigger this path at
3198 * will.)
3199 *
Mingming Cao617ba132006-10-11 01:20:53 -07003200 * NB. EXT4_STATE_JDATA is not set on files other than
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003201 * regular files. If somebody wants to bmap a directory
3202 * or symlink and gets confused because the buffer
3203 * hasn't yet been flushed to disk, they deserve
3204 * everything they get.
3205 */
3206
Mingming Cao617ba132006-10-11 01:20:53 -07003207 EXT4_I(inode)->i_state &= ~EXT4_STATE_JDATA;
3208 journal = EXT4_JOURNAL(inode);
Mingming Caodab291a2006-10-11 01:21:01 -07003209 jbd2_journal_lock_updates(journal);
3210 err = jbd2_journal_flush(journal);
3211 jbd2_journal_unlock_updates(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003212
3213 if (err)
3214 return 0;
3215 }
3216
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003217 return generic_block_bmap(mapping, block, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003218}
3219
Mingming Cao617ba132006-10-11 01:20:53 -07003220static int ext4_readpage(struct file *file, struct page *page)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003221{
Mingming Cao617ba132006-10-11 01:20:53 -07003222 return mpage_readpage(page, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003223}
3224
3225static int
Mingming Cao617ba132006-10-11 01:20:53 -07003226ext4_readpages(struct file *file, struct address_space *mapping,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003227 struct list_head *pages, unsigned nr_pages)
3228{
Mingming Cao617ba132006-10-11 01:20:53 -07003229 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003230}
3231
Mingming Cao617ba132006-10-11 01:20:53 -07003232static void ext4_invalidatepage(struct page *page, unsigned long offset)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003233{
Mingming Cao617ba132006-10-11 01:20:53 -07003234 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003235
3236 /*
3237 * If it's a full truncate we just forget about the pending dirtying
3238 */
3239 if (offset == 0)
3240 ClearPageChecked(page);
3241
Frank Mayhar03901312009-01-07 00:06:22 -05003242 if (journal)
3243 jbd2_journal_invalidatepage(journal, page, offset);
3244 else
3245 block_invalidatepage(page, offset);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003246}
3247
Mingming Cao617ba132006-10-11 01:20:53 -07003248static int ext4_releasepage(struct page *page, gfp_t wait)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003249{
Mingming Cao617ba132006-10-11 01:20:53 -07003250 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003251
3252 WARN_ON(PageChecked(page));
3253 if (!page_has_buffers(page))
3254 return 0;
Frank Mayhar03901312009-01-07 00:06:22 -05003255 if (journal)
3256 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3257 else
3258 return try_to_free_buffers(page);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003259}
3260
3261/*
3262 * If the O_DIRECT write will extend the file then add this inode to the
3263 * orphan list. So recovery will truncate it back to the original size
3264 * if the machine crashes during the write.
3265 *
3266 * If the O_DIRECT write is intantiating holes inside i_size and the machine
Jan Kara7fb54092008-02-10 01:08:38 -05003267 * crashes then stale disk data _may_ be exposed inside the file. But current
3268 * VFS code falls back into buffered path in that case so we are safe.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003269 */
Mingming Cao617ba132006-10-11 01:20:53 -07003270static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003271 const struct iovec *iov, loff_t offset,
3272 unsigned long nr_segs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003273{
3274 struct file *file = iocb->ki_filp;
3275 struct inode *inode = file->f_mapping->host;
Mingming Cao617ba132006-10-11 01:20:53 -07003276 struct ext4_inode_info *ei = EXT4_I(inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003277 handle_t *handle;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003278 ssize_t ret;
3279 int orphan = 0;
3280 size_t count = iov_length(iov, nr_segs);
3281
3282 if (rw == WRITE) {
3283 loff_t final_size = offset + count;
3284
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003285 if (final_size > inode->i_size) {
Jan Kara7fb54092008-02-10 01:08:38 -05003286 /* Credits for sb + inode write */
3287 handle = ext4_journal_start(inode, 2);
3288 if (IS_ERR(handle)) {
3289 ret = PTR_ERR(handle);
3290 goto out;
3291 }
Mingming Cao617ba132006-10-11 01:20:53 -07003292 ret = ext4_orphan_add(handle, inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003293 if (ret) {
3294 ext4_journal_stop(handle);
3295 goto out;
3296 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003297 orphan = 1;
3298 ei->i_disksize = inode->i_size;
Jan Kara7fb54092008-02-10 01:08:38 -05003299 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003300 }
3301 }
3302
3303 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
3304 offset, nr_segs,
Mingming Cao617ba132006-10-11 01:20:53 -07003305 ext4_get_block, NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003306
Jan Kara7fb54092008-02-10 01:08:38 -05003307 if (orphan) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003308 int err;
3309
Jan Kara7fb54092008-02-10 01:08:38 -05003310 /* Credits for sb + inode write */
3311 handle = ext4_journal_start(inode, 2);
3312 if (IS_ERR(handle)) {
3313 /* This is really bad luck. We've written the data
3314 * but cannot extend i_size. Bail out and pretend
3315 * the write failed... */
3316 ret = PTR_ERR(handle);
3317 goto out;
3318 }
3319 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07003320 ext4_orphan_del(handle, inode);
Jan Kara7fb54092008-02-10 01:08:38 -05003321 if (ret > 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003322 loff_t end = offset + ret;
3323 if (end > inode->i_size) {
3324 ei->i_disksize = end;
3325 i_size_write(inode, end);
3326 /*
3327 * We're going to return a positive `ret'
3328 * here due to non-zero-length I/O, so there's
3329 * no way of reporting error returns from
Mingming Cao617ba132006-10-11 01:20:53 -07003330 * ext4_mark_inode_dirty() to userspace. So
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003331 * ignore it.
3332 */
Mingming Cao617ba132006-10-11 01:20:53 -07003333 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003334 }
3335 }
Mingming Cao617ba132006-10-11 01:20:53 -07003336 err = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003337 if (ret == 0)
3338 ret = err;
3339 }
3340out:
3341 return ret;
3342}
3343
3344/*
Mingming Cao617ba132006-10-11 01:20:53 -07003345 * Pages can be marked dirty completely asynchronously from ext4's journalling
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003346 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3347 * much here because ->set_page_dirty is called under VFS locks. The page is
3348 * not necessarily locked.
3349 *
3350 * We cannot just dirty the page and leave attached buffers clean, because the
3351 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3352 * or jbddirty because all the journalling code will explode.
3353 *
3354 * So what we do is to mark the page "pending dirty" and next time writepage
3355 * is called, propagate that into the buffers appropriately.
3356 */
Mingming Cao617ba132006-10-11 01:20:53 -07003357static int ext4_journalled_set_page_dirty(struct page *page)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003358{
3359 SetPageChecked(page);
3360 return __set_page_dirty_nobuffers(page);
3361}
3362
Mingming Cao617ba132006-10-11 01:20:53 -07003363static const struct address_space_operations ext4_ordered_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003364 .readpage = ext4_readpage,
3365 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003366 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003367 .sync_page = block_sync_page,
3368 .write_begin = ext4_write_begin,
3369 .write_end = ext4_ordered_write_end,
3370 .bmap = ext4_bmap,
3371 .invalidatepage = ext4_invalidatepage,
3372 .releasepage = ext4_releasepage,
3373 .direct_IO = ext4_direct_IO,
3374 .migratepage = buffer_migrate_page,
3375 .is_partially_uptodate = block_is_partially_uptodate,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003376};
3377
Mingming Cao617ba132006-10-11 01:20:53 -07003378static const struct address_space_operations ext4_writeback_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003379 .readpage = ext4_readpage,
3380 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003381 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003382 .sync_page = block_sync_page,
3383 .write_begin = ext4_write_begin,
3384 .write_end = ext4_writeback_write_end,
3385 .bmap = ext4_bmap,
3386 .invalidatepage = ext4_invalidatepage,
3387 .releasepage = ext4_releasepage,
3388 .direct_IO = ext4_direct_IO,
3389 .migratepage = buffer_migrate_page,
3390 .is_partially_uptodate = block_is_partially_uptodate,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003391};
3392
Mingming Cao617ba132006-10-11 01:20:53 -07003393static const struct address_space_operations ext4_journalled_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003394 .readpage = ext4_readpage,
3395 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003396 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003397 .sync_page = block_sync_page,
3398 .write_begin = ext4_write_begin,
3399 .write_end = ext4_journalled_write_end,
3400 .set_page_dirty = ext4_journalled_set_page_dirty,
3401 .bmap = ext4_bmap,
3402 .invalidatepage = ext4_invalidatepage,
3403 .releasepage = ext4_releasepage,
3404 .is_partially_uptodate = block_is_partially_uptodate,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003405};
3406
Alex Tomas64769242008-07-11 19:27:31 -04003407static const struct address_space_operations ext4_da_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003408 .readpage = ext4_readpage,
3409 .readpages = ext4_readpages,
Aneesh Kumar K.V43ce1d22009-06-14 17:58:45 -04003410 .writepage = ext4_writepage,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07003411 .writepages = ext4_da_writepages,
3412 .sync_page = block_sync_page,
3413 .write_begin = ext4_da_write_begin,
3414 .write_end = ext4_da_write_end,
3415 .bmap = ext4_bmap,
3416 .invalidatepage = ext4_da_invalidatepage,
3417 .releasepage = ext4_releasepage,
3418 .direct_IO = ext4_direct_IO,
3419 .migratepage = buffer_migrate_page,
3420 .is_partially_uptodate = block_is_partially_uptodate,
Alex Tomas64769242008-07-11 19:27:31 -04003421};
3422
Mingming Cao617ba132006-10-11 01:20:53 -07003423void ext4_set_aops(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003424{
Aneesh Kumar K.Vcd1aac32008-07-11 19:27:31 -04003425 if (ext4_should_order_data(inode) &&
3426 test_opt(inode->i_sb, DELALLOC))
3427 inode->i_mapping->a_ops = &ext4_da_aops;
3428 else if (ext4_should_order_data(inode))
Mingming Cao617ba132006-10-11 01:20:53 -07003429 inode->i_mapping->a_ops = &ext4_ordered_aops;
Alex Tomas64769242008-07-11 19:27:31 -04003430 else if (ext4_should_writeback_data(inode) &&
3431 test_opt(inode->i_sb, DELALLOC))
3432 inode->i_mapping->a_ops = &ext4_da_aops;
Mingming Cao617ba132006-10-11 01:20:53 -07003433 else if (ext4_should_writeback_data(inode))
3434 inode->i_mapping->a_ops = &ext4_writeback_aops;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003435 else
Mingming Cao617ba132006-10-11 01:20:53 -07003436 inode->i_mapping->a_ops = &ext4_journalled_aops;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003437}
3438
3439/*
Mingming Cao617ba132006-10-11 01:20:53 -07003440 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003441 * up to the end of the block which corresponds to `from'.
3442 * This required during truncate. We need to physically zero the tail end
3443 * of that block so it doesn't yield old data if the file is later grown.
3444 */
Jan Karacf108bc2008-07-11 19:27:31 -04003445int ext4_block_truncate_page(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003446 struct address_space *mapping, loff_t from)
3447{
Mingming Cao617ba132006-10-11 01:20:53 -07003448 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003449 unsigned offset = from & (PAGE_CACHE_SIZE-1);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003450 unsigned blocksize, length, pos;
3451 ext4_lblk_t iblock;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003452 struct inode *inode = mapping->host;
3453 struct buffer_head *bh;
Jan Karacf108bc2008-07-11 19:27:31 -04003454 struct page *page;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003455 int err = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003456
Theodore Ts'of4a01012009-07-05 22:08:16 -04003457 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3458 mapping_gfp_mask(mapping) & ~__GFP_FS);
Jan Karacf108bc2008-07-11 19:27:31 -04003459 if (!page)
3460 return -EINVAL;
3461
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003462 blocksize = inode->i_sb->s_blocksize;
3463 length = blocksize - (offset & (blocksize - 1));
3464 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3465
3466 /*
3467 * For "nobh" option, we can only work if we don't need to
3468 * read-in the page - otherwise we create buffers to do the IO.
3469 */
3470 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
Mingming Cao617ba132006-10-11 01:20:53 -07003471 ext4_should_writeback_data(inode) && PageUptodate(page)) {
Christoph Lametereebd2aa2008-02-04 22:28:29 -08003472 zero_user(page, offset, length);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003473 set_page_dirty(page);
3474 goto unlock;
3475 }
3476
3477 if (!page_has_buffers(page))
3478 create_empty_buffers(page, blocksize, 0);
3479
3480 /* Find the buffer that contains "offset" */
3481 bh = page_buffers(page);
3482 pos = blocksize;
3483 while (offset >= pos) {
3484 bh = bh->b_this_page;
3485 iblock++;
3486 pos += blocksize;
3487 }
3488
3489 err = 0;
3490 if (buffer_freed(bh)) {
3491 BUFFER_TRACE(bh, "freed: skip");
3492 goto unlock;
3493 }
3494
3495 if (!buffer_mapped(bh)) {
3496 BUFFER_TRACE(bh, "unmapped");
Mingming Cao617ba132006-10-11 01:20:53 -07003497 ext4_get_block(inode, iblock, bh, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003498 /* unmapped? It's a hole - nothing to do */
3499 if (!buffer_mapped(bh)) {
3500 BUFFER_TRACE(bh, "still unmapped");
3501 goto unlock;
3502 }
3503 }
3504
3505 /* Ok, it's mapped. Make sure it's up-to-date */
3506 if (PageUptodate(page))
3507 set_buffer_uptodate(bh);
3508
3509 if (!buffer_uptodate(bh)) {
3510 err = -EIO;
3511 ll_rw_block(READ, 1, &bh);
3512 wait_on_buffer(bh);
3513 /* Uhhuh. Read error. Complain and punt. */
3514 if (!buffer_uptodate(bh))
3515 goto unlock;
3516 }
3517
Mingming Cao617ba132006-10-11 01:20:53 -07003518 if (ext4_should_journal_data(inode)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003519 BUFFER_TRACE(bh, "get write access");
Mingming Cao617ba132006-10-11 01:20:53 -07003520 err = ext4_journal_get_write_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003521 if (err)
3522 goto unlock;
3523 }
3524
Christoph Lametereebd2aa2008-02-04 22:28:29 -08003525 zero_user(page, offset, length);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003526
3527 BUFFER_TRACE(bh, "zeroed end of block");
3528
3529 err = 0;
Mingming Cao617ba132006-10-11 01:20:53 -07003530 if (ext4_should_journal_data(inode)) {
Frank Mayhar03901312009-01-07 00:06:22 -05003531 err = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003532 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07003533 if (ext4_should_order_data(inode))
Jan Kara678aaf42008-07-11 19:27:31 -04003534 err = ext4_jbd2_file_inode(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003535 mark_buffer_dirty(bh);
3536 }
3537
3538unlock:
3539 unlock_page(page);
3540 page_cache_release(page);
3541 return err;
3542}
3543
3544/*
3545 * Probably it should be a library function... search for first non-zero word
3546 * or memcmp with zero_page, whatever is better for particular architecture.
3547 * Linus?
3548 */
3549static inline int all_zeroes(__le32 *p, __le32 *q)
3550{
3551 while (p < q)
3552 if (*p++)
3553 return 0;
3554 return 1;
3555}
3556
3557/**
Mingming Cao617ba132006-10-11 01:20:53 -07003558 * ext4_find_shared - find the indirect blocks for partial truncation.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003559 * @inode: inode in question
3560 * @depth: depth of the affected branch
Mingming Cao617ba132006-10-11 01:20:53 -07003561 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003562 * @chain: place to store the pointers to partial indirect blocks
3563 * @top: place to the (detached) top of branch
3564 *
Mingming Cao617ba132006-10-11 01:20:53 -07003565 * This is a helper function used by ext4_truncate().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003566 *
3567 * When we do truncate() we may have to clean the ends of several
3568 * indirect blocks but leave the blocks themselves alive. Block is
3569 * partially truncated if some data below the new i_size is refered
3570 * from it (and it is on the path to the first completely truncated
3571 * data block, indeed). We have to free the top of that path along
3572 * with everything to the right of the path. Since no allocation
Mingming Cao617ba132006-10-11 01:20:53 -07003573 * past the truncation point is possible until ext4_truncate()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003574 * finishes, we may safely do the latter, but top of branch may
3575 * require special attention - pageout below the truncation point
3576 * might try to populate it.
3577 *
3578 * We atomically detach the top of branch from the tree, store the
3579 * block number of its root in *@top, pointers to buffer_heads of
3580 * partially truncated blocks - in @chain[].bh and pointers to
3581 * their last elements that should not be removed - in
3582 * @chain[].p. Return value is the pointer to last filled element
3583 * of @chain.
3584 *
3585 * The work left to caller to do the actual freeing of subtrees:
3586 * a) free the subtree starting from *@top
3587 * b) free the subtrees whose roots are stored in
3588 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
3589 * c) free the subtrees growing from the inode past the @chain[0].
3590 * (no partially truncated stuff there). */
3591
Mingming Cao617ba132006-10-11 01:20:53 -07003592static Indirect *ext4_find_shared(struct inode *inode, int depth,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003593 ext4_lblk_t offsets[4], Indirect chain[4],
3594 __le32 *top)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003595{
3596 Indirect *partial, *p;
3597 int k, err;
3598
3599 *top = 0;
3600 /* Make k index the deepest non-null offest + 1 */
3601 for (k = depth; k > 1 && !offsets[k-1]; k--)
3602 ;
Mingming Cao617ba132006-10-11 01:20:53 -07003603 partial = ext4_get_branch(inode, k, offsets, chain, &err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003604 /* Writer: pointers */
3605 if (!partial)
3606 partial = chain + k-1;
3607 /*
3608 * If the branch acquired continuation since we've looked at it -
3609 * fine, it should all survive and (new) top doesn't belong to us.
3610 */
3611 if (!partial->key && *partial->p)
3612 /* Writer: end */
3613 goto no_top;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003614 for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003615 ;
3616 /*
3617 * OK, we've found the last block that must survive. The rest of our
3618 * branch should be detached before unlocking. However, if that rest
3619 * of branch is all ours and does not grow immediately from the inode
3620 * it's easier to cheat and just decrement partial->p.
3621 */
3622 if (p == chain + k - 1 && p > chain) {
3623 p->p--;
3624 } else {
3625 *top = *p->p;
Mingming Cao617ba132006-10-11 01:20:53 -07003626 /* Nope, don't do this in ext4. Must leave the tree intact */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003627#if 0
3628 *p->p = 0;
3629#endif
3630 }
3631 /* Writer: end */
3632
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003633 while (partial > p) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003634 brelse(partial->bh);
3635 partial--;
3636 }
3637no_top:
3638 return partial;
3639}
3640
3641/*
3642 * Zero a number of block pointers in either an inode or an indirect block.
3643 * If we restart the transaction we must again get write access to the
3644 * indirect block for further modification.
3645 *
3646 * We release `count' blocks on disk, but (last - first) may be greater
3647 * than `count' because there can be holes in there.
3648 */
Mingming Cao617ba132006-10-11 01:20:53 -07003649static void ext4_clear_blocks(handle_t *handle, struct inode *inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003650 struct buffer_head *bh,
3651 ext4_fsblk_t block_to_free,
3652 unsigned long count, __le32 *first,
3653 __le32 *last)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003654{
3655 __le32 *p;
3656 if (try_to_extend_transaction(handle, inode)) {
3657 if (bh) {
Frank Mayhar03901312009-01-07 00:06:22 -05003658 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
3659 ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003660 }
Mingming Cao617ba132006-10-11 01:20:53 -07003661 ext4_mark_inode_dirty(handle, inode);
3662 ext4_journal_test_restart(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003663 if (bh) {
3664 BUFFER_TRACE(bh, "retaking write access");
Mingming Cao617ba132006-10-11 01:20:53 -07003665 ext4_journal_get_write_access(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003666 }
3667 }
3668
3669 /*
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04003670 * Any buffers which are on the journal will be in memory. We
3671 * find them on the hash table so jbd2_journal_revoke() will
3672 * run jbd2_journal_forget() on them. We've already detached
3673 * each block from the file, so bforget() in
3674 * jbd2_journal_forget() should be safe.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003675 *
Mingming Caodab291a2006-10-11 01:21:01 -07003676 * AKPM: turn on bforget in jbd2_journal_forget()!!!
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003677 */
3678 for (p = first; p < last; p++) {
3679 u32 nr = le32_to_cpu(*p);
3680 if (nr) {
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05003681 struct buffer_head *tbh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003682
3683 *p = 0;
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05003684 tbh = sb_find_get_block(inode->i_sb, nr);
3685 ext4_forget(handle, 0, inode, tbh, nr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003686 }
3687 }
3688
Alex Tomasc9de5602008-01-29 00:19:52 -05003689 ext4_free_blocks(handle, inode, block_to_free, count, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003690}
3691
3692/**
Mingming Cao617ba132006-10-11 01:20:53 -07003693 * ext4_free_data - free a list of data blocks
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003694 * @handle: handle for this transaction
3695 * @inode: inode we are dealing with
3696 * @this_bh: indirect buffer_head which contains *@first and *@last
3697 * @first: array of block numbers
3698 * @last: points immediately past the end of array
3699 *
3700 * We are freeing all blocks refered from that array (numbers are stored as
3701 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
3702 *
3703 * We accumulate contiguous runs of blocks to free. Conveniently, if these
3704 * blocks are contiguous then releasing them at one time will only affect one
3705 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
3706 * actually use a lot of journal space.
3707 *
3708 * @this_bh will be %NULL if @first and @last point into the inode's direct
3709 * block pointers.
3710 */
Mingming Cao617ba132006-10-11 01:20:53 -07003711static void ext4_free_data(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003712 struct buffer_head *this_bh,
3713 __le32 *first, __le32 *last)
3714{
Mingming Cao617ba132006-10-11 01:20:53 -07003715 ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003716 unsigned long count = 0; /* Number of blocks in the run */
3717 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
3718 corresponding to
3719 block_to_free */
Mingming Cao617ba132006-10-11 01:20:53 -07003720 ext4_fsblk_t nr; /* Current block # */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003721 __le32 *p; /* Pointer into inode/ind
3722 for current block */
3723 int err;
3724
3725 if (this_bh) { /* For indirect block */
3726 BUFFER_TRACE(this_bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07003727 err = ext4_journal_get_write_access(handle, this_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003728 /* Important: if we can't update the indirect pointers
3729 * to the blocks, we can't free them. */
3730 if (err)
3731 return;
3732 }
3733
3734 for (p = first; p < last; p++) {
3735 nr = le32_to_cpu(*p);
3736 if (nr) {
3737 /* accumulate blocks to free if they're contiguous */
3738 if (count == 0) {
3739 block_to_free = nr;
3740 block_to_free_p = p;
3741 count = 1;
3742 } else if (nr == block_to_free + count) {
3743 count++;
3744 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07003745 ext4_clear_blocks(handle, inode, this_bh,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003746 block_to_free,
3747 count, block_to_free_p, p);
3748 block_to_free = nr;
3749 block_to_free_p = p;
3750 count = 1;
3751 }
3752 }
3753 }
3754
3755 if (count > 0)
Mingming Cao617ba132006-10-11 01:20:53 -07003756 ext4_clear_blocks(handle, inode, this_bh, block_to_free,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003757 count, block_to_free_p, p);
3758
3759 if (this_bh) {
Frank Mayhar03901312009-01-07 00:06:22 -05003760 BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
Duane Griffin71dc8fb2008-07-11 19:27:31 -04003761
3762 /*
3763 * The buffer head should have an attached journal head at this
3764 * point. However, if the data is corrupted and an indirect
3765 * block pointed to itself, it would have been detached when
3766 * the block was cleared. Check for this instead of OOPSing.
3767 */
Theodore Ts'oe7f07962009-01-20 09:50:19 -05003768 if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
Frank Mayhar03901312009-01-07 00:06:22 -05003769 ext4_handle_dirty_metadata(handle, inode, this_bh);
Duane Griffin71dc8fb2008-07-11 19:27:31 -04003770 else
3771 ext4_error(inode->i_sb, __func__,
3772 "circular indirect block detected, "
3773 "inode=%lu, block=%llu",
3774 inode->i_ino,
3775 (unsigned long long) this_bh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003776 }
3777}
3778
3779/**
Mingming Cao617ba132006-10-11 01:20:53 -07003780 * ext4_free_branches - free an array of branches
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003781 * @handle: JBD handle for this transaction
3782 * @inode: inode we are dealing with
3783 * @parent_bh: the buffer_head which contains *@first and *@last
3784 * @first: array of block numbers
3785 * @last: pointer immediately past the end of array
3786 * @depth: depth of the branches to free
3787 *
3788 * We are freeing all blocks refered from these branches (numbers are
3789 * stored as little-endian 32-bit) and updating @inode->i_blocks
3790 * appropriately.
3791 */
Mingming Cao617ba132006-10-11 01:20:53 -07003792static void ext4_free_branches(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003793 struct buffer_head *parent_bh,
3794 __le32 *first, __le32 *last, int depth)
3795{
Mingming Cao617ba132006-10-11 01:20:53 -07003796 ext4_fsblk_t nr;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003797 __le32 *p;
3798
Frank Mayhar03901312009-01-07 00:06:22 -05003799 if (ext4_handle_is_aborted(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003800 return;
3801
3802 if (depth--) {
3803 struct buffer_head *bh;
Mingming Cao617ba132006-10-11 01:20:53 -07003804 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003805 p = last;
3806 while (--p >= first) {
3807 nr = le32_to_cpu(*p);
3808 if (!nr)
3809 continue; /* A hole */
3810
3811 /* Go read the buffer for the next level down */
3812 bh = sb_bread(inode->i_sb, nr);
3813
3814 /*
3815 * A read failure? Report error and clear slot
3816 * (should be rare).
3817 */
3818 if (!bh) {
Mingming Cao617ba132006-10-11 01:20:53 -07003819 ext4_error(inode->i_sb, "ext4_free_branches",
Mingming Cao2ae02102006-10-11 01:21:11 -07003820 "Read failure, inode=%lu, block=%llu",
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003821 inode->i_ino, nr);
3822 continue;
3823 }
3824
3825 /* This zaps the entire block. Bottom up. */
3826 BUFFER_TRACE(bh, "free child branches");
Mingming Cao617ba132006-10-11 01:20:53 -07003827 ext4_free_branches(handle, inode, bh,
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04003828 (__le32 *) bh->b_data,
3829 (__le32 *) bh->b_data + addr_per_block,
3830 depth);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003831
3832 /*
3833 * We've probably journalled the indirect block several
3834 * times during the truncate. But it's no longer
3835 * needed and we now drop it from the transaction via
Mingming Caodab291a2006-10-11 01:21:01 -07003836 * jbd2_journal_revoke().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003837 *
3838 * That's easy if it's exclusively part of this
3839 * transaction. But if it's part of the committing
Mingming Caodab291a2006-10-11 01:21:01 -07003840 * transaction then jbd2_journal_forget() will simply
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003841 * brelse() it. That means that if the underlying
Mingming Cao617ba132006-10-11 01:20:53 -07003842 * block is reallocated in ext4_get_block(),
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003843 * unmap_underlying_metadata() will find this block
3844 * and will try to get rid of it. damn, damn.
3845 *
3846 * If this block has already been committed to the
3847 * journal, a revoke record will be written. And
3848 * revoke records must be emitted *before* clearing
3849 * this block's bit in the bitmaps.
3850 */
Mingming Cao617ba132006-10-11 01:20:53 -07003851 ext4_forget(handle, 1, inode, bh, bh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003852
3853 /*
3854 * Everything below this this pointer has been
3855 * released. Now let this top-of-subtree go.
3856 *
3857 * We want the freeing of this indirect block to be
3858 * atomic in the journal with the updating of the
3859 * bitmap block which owns it. So make some room in
3860 * the journal.
3861 *
3862 * We zero the parent pointer *after* freeing its
3863 * pointee in the bitmaps, so if extend_transaction()
3864 * for some reason fails to put the bitmap changes and
3865 * the release into the same transaction, recovery
3866 * will merely complain about releasing a free block,
3867 * rather than leaking blocks.
3868 */
Frank Mayhar03901312009-01-07 00:06:22 -05003869 if (ext4_handle_is_aborted(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003870 return;
3871 if (try_to_extend_transaction(handle, inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07003872 ext4_mark_inode_dirty(handle, inode);
3873 ext4_journal_test_restart(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003874 }
3875
Alex Tomasc9de5602008-01-29 00:19:52 -05003876 ext4_free_blocks(handle, inode, nr, 1, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003877
3878 if (parent_bh) {
3879 /*
3880 * The block which we have just freed is
3881 * pointed to by an indirect block: journal it
3882 */
3883 BUFFER_TRACE(parent_bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07003884 if (!ext4_journal_get_write_access(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003885 parent_bh)){
3886 *p = 0;
3887 BUFFER_TRACE(parent_bh,
Frank Mayhar03901312009-01-07 00:06:22 -05003888 "call ext4_handle_dirty_metadata");
3889 ext4_handle_dirty_metadata(handle,
3890 inode,
3891 parent_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003892 }
3893 }
3894 }
3895 } else {
3896 /* We have reached the bottom of the tree. */
3897 BUFFER_TRACE(parent_bh, "free data blocks");
Mingming Cao617ba132006-10-11 01:20:53 -07003898 ext4_free_data(handle, inode, parent_bh, first, last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003899 }
3900}
3901
Duane Griffin91ef4ca2008-07-11 19:27:31 -04003902int ext4_can_truncate(struct inode *inode)
3903{
3904 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
3905 return 0;
3906 if (S_ISREG(inode->i_mode))
3907 return 1;
3908 if (S_ISDIR(inode->i_mode))
3909 return 1;
3910 if (S_ISLNK(inode->i_mode))
3911 return !ext4_inode_is_fast_symlink(inode);
3912 return 0;
3913}
3914
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003915/*
Mingming Cao617ba132006-10-11 01:20:53 -07003916 * ext4_truncate()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003917 *
Mingming Cao617ba132006-10-11 01:20:53 -07003918 * We block out ext4_get_block() block instantiations across the entire
3919 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003920 * simultaneously on behalf of the same inode.
3921 *
3922 * As we work through the truncate and commmit bits of it to the journal there
3923 * is one core, guiding principle: the file's tree must always be consistent on
3924 * disk. We must be able to restart the truncate after a crash.
3925 *
3926 * The file's tree may be transiently inconsistent in memory (although it
3927 * probably isn't), but whenever we close off and commit a journal transaction,
3928 * the contents of (the filesystem + the journal) must be consistent and
3929 * restartable. It's pretty simple, really: bottom up, right to left (although
3930 * left-to-right works OK too).
3931 *
3932 * Note that at recovery time, journal replay occurs *before* the restart of
3933 * truncate against the orphan inode list.
3934 *
3935 * The committed inode has the new, desired i_size (which is the same as
Mingming Cao617ba132006-10-11 01:20:53 -07003936 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003937 * that this inode's truncate did not complete and it will again call
Mingming Cao617ba132006-10-11 01:20:53 -07003938 * ext4_truncate() to have another go. So there will be instantiated blocks
3939 * to the right of the truncation point in a crashed ext4 filesystem. But
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003940 * that's fine - as long as they are linked from the inode, the post-crash
Mingming Cao617ba132006-10-11 01:20:53 -07003941 * ext4_truncate() run will find them and release them.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003942 */
Mingming Cao617ba132006-10-11 01:20:53 -07003943void ext4_truncate(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003944{
3945 handle_t *handle;
Mingming Cao617ba132006-10-11 01:20:53 -07003946 struct ext4_inode_info *ei = EXT4_I(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003947 __le32 *i_data = ei->i_data;
Mingming Cao617ba132006-10-11 01:20:53 -07003948 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003949 struct address_space *mapping = inode->i_mapping;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003950 ext4_lblk_t offsets[4];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003951 Indirect chain[4];
3952 Indirect *partial;
3953 __le32 nr = 0;
3954 int n;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003955 ext4_lblk_t last_block;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003956 unsigned blocksize = inode->i_sb->s_blocksize;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003957
Duane Griffin91ef4ca2008-07-11 19:27:31 -04003958 if (!ext4_can_truncate(inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003959 return;
3960
Theodore Ts'o0eab9282009-06-09 09:54:40 -04003961 if (ei->i_disksize && inode->i_size == 0 &&
3962 !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
Theodore Ts'o7d8f9f72009-02-24 08:21:14 -05003963 ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
3964
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05003965 if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
Jan Karacf108bc2008-07-11 19:27:31 -04003966 ext4_ext_truncate(inode);
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05003967 return;
3968 }
Alex Tomasa86c6182006-10-11 01:21:03 -07003969
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003970 handle = start_transaction(inode);
Jan Karacf108bc2008-07-11 19:27:31 -04003971 if (IS_ERR(handle))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003972 return; /* AKPM: return what? */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003973
3974 last_block = (inode->i_size + blocksize-1)
Mingming Cao617ba132006-10-11 01:20:53 -07003975 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003976
Jan Karacf108bc2008-07-11 19:27:31 -04003977 if (inode->i_size & (blocksize - 1))
3978 if (ext4_block_truncate_page(handle, mapping, inode->i_size))
3979 goto out_stop;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003980
Mingming Cao617ba132006-10-11 01:20:53 -07003981 n = ext4_block_to_path(inode, last_block, offsets, NULL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003982 if (n == 0)
3983 goto out_stop; /* error */
3984
3985 /*
3986 * OK. This truncate is going to happen. We add the inode to the
3987 * orphan list, so that if this truncate spans multiple transactions,
3988 * and we crash, we will resume the truncate when the filesystem
3989 * recovers. It also marks the inode dirty, to catch the new size.
3990 *
3991 * Implication: the file must always be in a sane, consistent
3992 * truncatable state while each transaction commits.
3993 */
Mingming Cao617ba132006-10-11 01:20:53 -07003994 if (ext4_orphan_add(handle, inode))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003995 goto out_stop;
3996
3997 /*
Mingming Cao632eaea2008-07-11 19:27:31 -04003998 * From here we block out all ext4_get_block() callers who want to
3999 * modify the block allocation tree.
4000 */
4001 down_write(&ei->i_data_sem);
Theodore Ts'ob4df2032008-08-13 21:44:34 -04004002
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04004003 ext4_discard_preallocations(inode);
Theodore Ts'ob4df2032008-08-13 21:44:34 -04004004
Mingming Cao632eaea2008-07-11 19:27:31 -04004005 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004006 * The orphan list entry will now protect us from any crash which
4007 * occurs before the truncate completes, so it is now safe to propagate
4008 * the new, shorter inode size (held for now in i_size) into the
4009 * on-disk inode. We do this via i_disksize, which is the value which
Mingming Cao617ba132006-10-11 01:20:53 -07004010 * ext4 *really* writes onto the disk inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004011 */
4012 ei->i_disksize = inode->i_size;
4013
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004014 if (n == 1) { /* direct blocks */
Mingming Cao617ba132006-10-11 01:20:53 -07004015 ext4_free_data(handle, inode, NULL, i_data+offsets[0],
4016 i_data + EXT4_NDIR_BLOCKS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004017 goto do_indirects;
4018 }
4019
Mingming Cao617ba132006-10-11 01:20:53 -07004020 partial = ext4_find_shared(inode, n, offsets, chain, &nr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004021 /* Kill the top of shared branch (not detached) */
4022 if (nr) {
4023 if (partial == chain) {
4024 /* Shared branch grows from the inode */
Mingming Cao617ba132006-10-11 01:20:53 -07004025 ext4_free_branches(handle, inode, NULL,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004026 &nr, &nr+1, (chain+n-1) - partial);
4027 *partial->p = 0;
4028 /*
4029 * We mark the inode dirty prior to restart,
4030 * and prior to stop. No need for it here.
4031 */
4032 } else {
4033 /* Shared branch grows from an indirect block */
4034 BUFFER_TRACE(partial->bh, "get_write_access");
Mingming Cao617ba132006-10-11 01:20:53 -07004035 ext4_free_branches(handle, inode, partial->bh,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004036 partial->p,
4037 partial->p+1, (chain+n-1) - partial);
4038 }
4039 }
4040 /* Clear the ends of indirect blocks on the shared branch */
4041 while (partial > chain) {
Mingming Cao617ba132006-10-11 01:20:53 -07004042 ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004043 (__le32*)partial->bh->b_data+addr_per_block,
4044 (chain+n-1) - partial);
4045 BUFFER_TRACE(partial->bh, "call brelse");
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004046 brelse(partial->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004047 partial--;
4048 }
4049do_indirects:
4050 /* Kill the remaining (whole) subtrees */
4051 switch (offsets[0]) {
4052 default:
Mingming Cao617ba132006-10-11 01:20:53 -07004053 nr = i_data[EXT4_IND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004054 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004055 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
4056 i_data[EXT4_IND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004057 }
Mingming Cao617ba132006-10-11 01:20:53 -07004058 case EXT4_IND_BLOCK:
4059 nr = i_data[EXT4_DIND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004060 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004061 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
4062 i_data[EXT4_DIND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004063 }
Mingming Cao617ba132006-10-11 01:20:53 -07004064 case EXT4_DIND_BLOCK:
4065 nr = i_data[EXT4_TIND_BLOCK];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004066 if (nr) {
Mingming Cao617ba132006-10-11 01:20:53 -07004067 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
4068 i_data[EXT4_TIND_BLOCK] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004069 }
Mingming Cao617ba132006-10-11 01:20:53 -07004070 case EXT4_TIND_BLOCK:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004071 ;
4072 }
4073
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05004074 up_write(&ei->i_data_sem);
Kalpak Shahef7f3832007-07-18 09:15:20 -04004075 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
Mingming Cao617ba132006-10-11 01:20:53 -07004076 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004077
4078 /*
4079 * In a multi-transaction truncate, we only make the final transaction
4080 * synchronous
4081 */
4082 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -05004083 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004084out_stop:
4085 /*
4086 * If this was a simple ftruncate(), and the file will remain alive
4087 * then we need to clear up the orphan record which we created above.
4088 * However, if this was a real unlink then we were called by
Mingming Cao617ba132006-10-11 01:20:53 -07004089 * ext4_delete_inode(), and we allow that function to clean up the
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004090 * orphan info for us.
4091 */
4092 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07004093 ext4_orphan_del(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004094
Mingming Cao617ba132006-10-11 01:20:53 -07004095 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004096}
4097
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004098/*
Mingming Cao617ba132006-10-11 01:20:53 -07004099 * ext4_get_inode_loc returns with an extra refcount against the inode's
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004100 * underlying buffer_head on success. If 'in_mem' is true, we have all
4101 * data in memory that is needed to recreate the on-disk version of this
4102 * inode.
4103 */
Mingming Cao617ba132006-10-11 01:20:53 -07004104static int __ext4_get_inode_loc(struct inode *inode,
4105 struct ext4_iloc *iloc, int in_mem)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004106{
Theodore Ts'o240799c2008-10-09 23:53:47 -04004107 struct ext4_group_desc *gdp;
4108 struct buffer_head *bh;
4109 struct super_block *sb = inode->i_sb;
4110 ext4_fsblk_t block;
4111 int inodes_per_block, inode_offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004112
Aneesh Kumar K.V3a06d772008-11-22 15:04:59 -05004113 iloc->bh = NULL;
Theodore Ts'o240799c2008-10-09 23:53:47 -04004114 if (!ext4_valid_inum(sb, inode->i_ino))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004115 return -EIO;
4116
Theodore Ts'o240799c2008-10-09 23:53:47 -04004117 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
4118 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
4119 if (!gdp)
4120 return -EIO;
4121
4122 /*
4123 * Figure out the offset within the block group inode table
4124 */
4125 inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb));
4126 inode_offset = ((inode->i_ino - 1) %
4127 EXT4_INODES_PER_GROUP(sb));
4128 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
4129 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
4130
4131 bh = sb_getblk(sb, block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004132 if (!bh) {
Theodore Ts'o240799c2008-10-09 23:53:47 -04004133 ext4_error(sb, "ext4_get_inode_loc", "unable to read "
4134 "inode block - inode=%lu, block=%llu",
4135 inode->i_ino, block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004136 return -EIO;
4137 }
4138 if (!buffer_uptodate(bh)) {
4139 lock_buffer(bh);
Hidehiro Kawai9c83a922008-07-26 16:39:26 -04004140
4141 /*
4142 * If the buffer has the write error flag, we have failed
4143 * to write out another inode in the same block. In this
4144 * case, we don't have to read the block because we may
4145 * read the old inode data successfully.
4146 */
4147 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
4148 set_buffer_uptodate(bh);
4149
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004150 if (buffer_uptodate(bh)) {
4151 /* someone brought it uptodate while we waited */
4152 unlock_buffer(bh);
4153 goto has_buffer;
4154 }
4155
4156 /*
4157 * If we have all information of the inode in memory and this
4158 * is the only valid inode in the block, we need not read the
4159 * block.
4160 */
4161 if (in_mem) {
4162 struct buffer_head *bitmap_bh;
Theodore Ts'o240799c2008-10-09 23:53:47 -04004163 int i, start;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004164
Theodore Ts'o240799c2008-10-09 23:53:47 -04004165 start = inode_offset & ~(inodes_per_block - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004166
4167 /* Is the inode bitmap in cache? */
Theodore Ts'o240799c2008-10-09 23:53:47 -04004168 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004169 if (!bitmap_bh)
4170 goto make_io;
4171
4172 /*
4173 * If the inode bitmap isn't in cache then the
4174 * optimisation may end up performing two reads instead
4175 * of one, so skip it.
4176 */
4177 if (!buffer_uptodate(bitmap_bh)) {
4178 brelse(bitmap_bh);
4179 goto make_io;
4180 }
Theodore Ts'o240799c2008-10-09 23:53:47 -04004181 for (i = start; i < start + inodes_per_block; i++) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004182 if (i == inode_offset)
4183 continue;
Mingming Cao617ba132006-10-11 01:20:53 -07004184 if (ext4_test_bit(i, bitmap_bh->b_data))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004185 break;
4186 }
4187 brelse(bitmap_bh);
Theodore Ts'o240799c2008-10-09 23:53:47 -04004188 if (i == start + inodes_per_block) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004189 /* all other inodes are free, so skip I/O */
4190 memset(bh->b_data, 0, bh->b_size);
4191 set_buffer_uptodate(bh);
4192 unlock_buffer(bh);
4193 goto has_buffer;
4194 }
4195 }
4196
4197make_io:
4198 /*
Theodore Ts'o240799c2008-10-09 23:53:47 -04004199 * If we need to do any I/O, try to pre-readahead extra
4200 * blocks from the inode table.
4201 */
4202 if (EXT4_SB(sb)->s_inode_readahead_blks) {
4203 ext4_fsblk_t b, end, table;
4204 unsigned num;
4205
4206 table = ext4_inode_table(sb, gdp);
Theodore Ts'ob713a5e2009-03-31 09:11:14 -04004207 /* s_inode_readahead_blks is always a power of 2 */
Theodore Ts'o240799c2008-10-09 23:53:47 -04004208 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
4209 if (table > b)
4210 b = table;
4211 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
4212 num = EXT4_INODES_PER_GROUP(sb);
4213 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4214 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
Aneesh Kumar K.V560671a2009-01-05 22:20:24 -05004215 num -= ext4_itable_unused_count(sb, gdp);
Theodore Ts'o240799c2008-10-09 23:53:47 -04004216 table += num / inodes_per_block;
4217 if (end > table)
4218 end = table;
4219 while (b <= end)
4220 sb_breadahead(sb, b++);
4221 }
4222
4223 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004224 * There are other valid inodes in the buffer, this inode
4225 * has in-inode xattrs, or we don't have this inode in memory.
4226 * Read the block from disk.
4227 */
4228 get_bh(bh);
4229 bh->b_end_io = end_buffer_read_sync;
4230 submit_bh(READ_META, bh);
4231 wait_on_buffer(bh);
4232 if (!buffer_uptodate(bh)) {
Theodore Ts'o240799c2008-10-09 23:53:47 -04004233 ext4_error(sb, __func__,
4234 "unable to read inode block - inode=%lu, "
4235 "block=%llu", inode->i_ino, block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004236 brelse(bh);
4237 return -EIO;
4238 }
4239 }
4240has_buffer:
4241 iloc->bh = bh;
4242 return 0;
4243}
4244
Mingming Cao617ba132006-10-11 01:20:53 -07004245int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004246{
4247 /* We have all inode data except xattrs in memory here. */
Mingming Cao617ba132006-10-11 01:20:53 -07004248 return __ext4_get_inode_loc(inode, iloc,
4249 !(EXT4_I(inode)->i_state & EXT4_STATE_XATTR));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004250}
4251
Mingming Cao617ba132006-10-11 01:20:53 -07004252void ext4_set_inode_flags(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004253{
Mingming Cao617ba132006-10-11 01:20:53 -07004254 unsigned int flags = EXT4_I(inode)->i_flags;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004255
4256 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
Mingming Cao617ba132006-10-11 01:20:53 -07004257 if (flags & EXT4_SYNC_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004258 inode->i_flags |= S_SYNC;
Mingming Cao617ba132006-10-11 01:20:53 -07004259 if (flags & EXT4_APPEND_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004260 inode->i_flags |= S_APPEND;
Mingming Cao617ba132006-10-11 01:20:53 -07004261 if (flags & EXT4_IMMUTABLE_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004262 inode->i_flags |= S_IMMUTABLE;
Mingming Cao617ba132006-10-11 01:20:53 -07004263 if (flags & EXT4_NOATIME_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004264 inode->i_flags |= S_NOATIME;
Mingming Cao617ba132006-10-11 01:20:53 -07004265 if (flags & EXT4_DIRSYNC_FL)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004266 inode->i_flags |= S_DIRSYNC;
4267}
4268
Jan Karaff9ddf72007-07-18 09:24:20 -04004269/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4270void ext4_get_inode_flags(struct ext4_inode_info *ei)
4271{
4272 unsigned int flags = ei->vfs_inode.i_flags;
4273
4274 ei->i_flags &= ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
4275 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|EXT4_DIRSYNC_FL);
4276 if (flags & S_SYNC)
4277 ei->i_flags |= EXT4_SYNC_FL;
4278 if (flags & S_APPEND)
4279 ei->i_flags |= EXT4_APPEND_FL;
4280 if (flags & S_IMMUTABLE)
4281 ei->i_flags |= EXT4_IMMUTABLE_FL;
4282 if (flags & S_NOATIME)
4283 ei->i_flags |= EXT4_NOATIME_FL;
4284 if (flags & S_DIRSYNC)
4285 ei->i_flags |= EXT4_DIRSYNC_FL;
4286}
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004287
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004288static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004289 struct ext4_inode_info *ei)
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004290{
4291 blkcnt_t i_blocks ;
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004292 struct inode *inode = &(ei->vfs_inode);
4293 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004294
4295 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4296 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
4297 /* we are using combined 48 bit field */
4298 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
4299 le32_to_cpu(raw_inode->i_blocks_lo);
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004300 if (ei->i_flags & EXT4_HUGE_FILE_FL) {
4301 /* i_blocks represent file system block size */
4302 return i_blocks << (inode->i_blkbits - 9);
4303 } else {
4304 return i_blocks;
4305 }
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004306 } else {
4307 return le32_to_cpu(raw_inode->i_blocks_lo);
4308 }
4309}
Jan Karaff9ddf72007-07-18 09:24:20 -04004310
David Howells1d1fe1e2008-02-07 00:15:37 -08004311struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004312{
Mingming Cao617ba132006-10-11 01:20:53 -07004313 struct ext4_iloc iloc;
4314 struct ext4_inode *raw_inode;
David Howells1d1fe1e2008-02-07 00:15:37 -08004315 struct ext4_inode_info *ei;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004316 struct buffer_head *bh;
David Howells1d1fe1e2008-02-07 00:15:37 -08004317 struct inode *inode;
4318 long ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004319 int block;
4320
David Howells1d1fe1e2008-02-07 00:15:37 -08004321 inode = iget_locked(sb, ino);
4322 if (!inode)
4323 return ERR_PTR(-ENOMEM);
4324 if (!(inode->i_state & I_NEW))
4325 return inode;
4326
4327 ei = EXT4_I(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004328
David Howells1d1fe1e2008-02-07 00:15:37 -08004329 ret = __ext4_get_inode_loc(inode, &iloc, 0);
4330 if (ret < 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004331 goto bad_inode;
4332 bh = iloc.bh;
Mingming Cao617ba132006-10-11 01:20:53 -07004333 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004334 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4335 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4336 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004337 if (!(test_opt(inode->i_sb, NO_UID32))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004338 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4339 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4340 }
4341 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004342
4343 ei->i_state = 0;
4344 ei->i_dir_start_lookup = 0;
4345 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4346 /* We now have enough fields to check if the inode was active or not.
4347 * This is needed because nfsd might try to access dead inodes
4348 * the test is that same one that e2fsck uses
4349 * NeilBrown 1999oct15
4350 */
4351 if (inode->i_nlink == 0) {
4352 if (inode->i_mode == 0 ||
Mingming Cao617ba132006-10-11 01:20:53 -07004353 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004354 /* this inode is deleted */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004355 brelse(bh);
David Howells1d1fe1e2008-02-07 00:15:37 -08004356 ret = -ESTALE;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004357 goto bad_inode;
4358 }
4359 /* The only unlinked inodes we let through here have
4360 * valid i_mode and are being read by the orphan
4361 * recovery code: that's fine, we're about to complete
4362 * the process of deleting those. */
4363 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004364 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004365 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
Aneesh Kumar K.V7973c0c2008-01-28 23:58:27 -05004366 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
Theodore Ts'oa9e81742009-04-24 16:11:18 -04004367 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
Badari Pulavartya1ddeb72006-10-11 01:21:09 -07004368 ei->i_file_acl |=
4369 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004370 inode->i_size = ext4_isize(raw_inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004371 ei->i_disksize = inode->i_size;
4372 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4373 ei->i_block_group = iloc.block_group;
Theodore Ts'oa4912122009-03-12 12:18:34 -04004374 ei->i_last_alloc_group = ~0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004375 /*
4376 * NOTE! The in-memory inode i_data array is in little-endian order
4377 * even on big-endian machines: we do NOT byteswap the block numbers!
4378 */
Mingming Cao617ba132006-10-11 01:20:53 -07004379 for (block = 0; block < EXT4_N_BLOCKS; block++)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004380 ei->i_data[block] = raw_inode->i_block[block];
4381 INIT_LIST_HEAD(&ei->i_orphan);
4382
Eric Sandeen0040d982008-02-05 22:36:43 -05004383 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004384 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
Mingming Cao617ba132006-10-11 01:20:53 -07004385 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
Kirill Korotaeve5d28612007-06-23 17:16:51 -07004386 EXT4_INODE_SIZE(inode->i_sb)) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004387 brelse(bh);
David Howells1d1fe1e2008-02-07 00:15:37 -08004388 ret = -EIO;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004389 goto bad_inode;
Kirill Korotaeve5d28612007-06-23 17:16:51 -07004390 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004391 if (ei->i_extra_isize == 0) {
4392 /* The extra space is currently unused. Use it. */
Mingming Cao617ba132006-10-11 01:20:53 -07004393 ei->i_extra_isize = sizeof(struct ext4_inode) -
4394 EXT4_GOOD_OLD_INODE_SIZE;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004395 } else {
4396 __le32 *magic = (void *)raw_inode +
Mingming Cao617ba132006-10-11 01:20:53 -07004397 EXT4_GOOD_OLD_INODE_SIZE +
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004398 ei->i_extra_isize;
Mingming Cao617ba132006-10-11 01:20:53 -07004399 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004400 ei->i_state |= EXT4_STATE_XATTR;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004401 }
4402 } else
4403 ei->i_extra_isize = 0;
4404
Kalpak Shahef7f3832007-07-18 09:15:20 -04004405 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
4406 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
4407 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
4408 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4409
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004410 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
4411 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4412 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4413 inode->i_version |=
4414 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4415 }
4416
Theodore Ts'oc4b5a612009-04-24 18:45:35 -04004417 ret = 0;
Theodore Ts'o485c26e2009-04-24 13:43:20 -04004418 if (ei->i_file_acl &&
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004419 ((ei->i_file_acl <
Theodore Ts'o485c26e2009-04-24 13:43:20 -04004420 (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
4421 EXT4_SB(sb)->s_gdb_count)) ||
4422 (ei->i_file_acl >= ext4_blocks_count(EXT4_SB(sb)->s_es)))) {
4423 ext4_error(sb, __func__,
4424 "bad extended attribute block %llu in inode #%lu",
4425 ei->i_file_acl, inode->i_ino);
4426 ret = -EIO;
4427 goto bad_inode;
4428 } else if (ei->i_flags & EXT4_EXTENTS_FL) {
Theodore Ts'oc4b5a612009-04-24 18:45:35 -04004429 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4430 (S_ISLNK(inode->i_mode) &&
4431 !ext4_inode_is_fast_symlink(inode)))
4432 /* Validate extent which is part of inode */
4433 ret = ext4_ext_check_inode(inode);
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004434 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
Thiemo Nagelfe2c8192009-03-31 08:36:10 -04004435 (S_ISLNK(inode->i_mode) &&
4436 !ext4_inode_is_fast_symlink(inode))) {
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004437 /* Validate block references which are part of inode */
Thiemo Nagelfe2c8192009-03-31 08:36:10 -04004438 ret = ext4_check_inode_blockref(inode);
4439 }
4440 if (ret) {
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004441 brelse(bh);
4442 goto bad_inode;
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -04004443 }
4444
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004445 if (S_ISREG(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004446 inode->i_op = &ext4_file_inode_operations;
4447 inode->i_fop = &ext4_file_operations;
4448 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004449 } else if (S_ISDIR(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004450 inode->i_op = &ext4_dir_inode_operations;
4451 inode->i_fop = &ext4_dir_operations;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004452 } else if (S_ISLNK(inode->i_mode)) {
Duane Griffine83c1392008-12-19 20:47:15 +00004453 if (ext4_inode_is_fast_symlink(inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004454 inode->i_op = &ext4_fast_symlink_inode_operations;
Duane Griffine83c1392008-12-19 20:47:15 +00004455 nd_terminate_link(ei->i_data, inode->i_size,
4456 sizeof(ei->i_data) - 1);
4457 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07004458 inode->i_op = &ext4_symlink_inode_operations;
4459 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004460 }
Theodore Ts'o563bdd62009-03-26 00:06:19 -04004461 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
4462 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
Mingming Cao617ba132006-10-11 01:20:53 -07004463 inode->i_op = &ext4_special_inode_operations;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004464 if (raw_inode->i_block[0])
4465 init_special_inode(inode, inode->i_mode,
4466 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
4467 else
4468 init_special_inode(inode, inode->i_mode,
4469 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
Theodore Ts'o563bdd62009-03-26 00:06:19 -04004470 } else {
4471 brelse(bh);
4472 ret = -EIO;
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004473 ext4_error(inode->i_sb, __func__,
Theodore Ts'o563bdd62009-03-26 00:06:19 -04004474 "bogus i_mode (%o) for inode=%lu",
4475 inode->i_mode, inode->i_ino);
4476 goto bad_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004477 }
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004478 brelse(iloc.bh);
Mingming Cao617ba132006-10-11 01:20:53 -07004479 ext4_set_inode_flags(inode);
David Howells1d1fe1e2008-02-07 00:15:37 -08004480 unlock_new_inode(inode);
4481 return inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004482
4483bad_inode:
David Howells1d1fe1e2008-02-07 00:15:37 -08004484 iget_failed(inode);
4485 return ERR_PTR(ret);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004486}
4487
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004488static int ext4_inode_blocks_set(handle_t *handle,
4489 struct ext4_inode *raw_inode,
4490 struct ext4_inode_info *ei)
4491{
4492 struct inode *inode = &(ei->vfs_inode);
4493 u64 i_blocks = inode->i_blocks;
4494 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004495
4496 if (i_blocks <= ~0U) {
4497 /*
4498 * i_blocks can be represnted in a 32 bit variable
4499 * as multiple of 512 bytes
4500 */
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004501 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004502 raw_inode->i_blocks_high = 0;
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004503 ei->i_flags &= ~EXT4_HUGE_FILE_FL;
Theodore Ts'of287a1a2008-10-16 22:50:48 -04004504 return 0;
4505 }
4506 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
4507 return -EFBIG;
4508
4509 if (i_blocks <= 0xffffffffffffULL) {
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004510 /*
4511 * i_blocks can be represented in a 48 bit variable
4512 * as multiple of 512 bytes
4513 */
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004514 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004515 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004516 ei->i_flags &= ~EXT4_HUGE_FILE_FL;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004517 } else {
Aneesh Kumar K.V8180a562008-01-28 23:58:27 -05004518 ei->i_flags |= EXT4_HUGE_FILE_FL;
4519 /* i_block is stored in file system block size */
4520 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4521 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4522 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004523 }
Theodore Ts'of287a1a2008-10-16 22:50:48 -04004524 return 0;
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004525}
4526
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004527/*
4528 * Post the struct inode info into an on-disk inode location in the
4529 * buffer-cache. This gobbles the caller's reference to the
4530 * buffer_head in the inode location struct.
4531 *
4532 * The caller must have write access to iloc->bh.
4533 */
Mingming Cao617ba132006-10-11 01:20:53 -07004534static int ext4_do_update_inode(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004535 struct inode *inode,
Mingming Cao617ba132006-10-11 01:20:53 -07004536 struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004537{
Mingming Cao617ba132006-10-11 01:20:53 -07004538 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4539 struct ext4_inode_info *ei = EXT4_I(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004540 struct buffer_head *bh = iloc->bh;
4541 int err = 0, rc, block;
4542
4543 /* For fields not not tracking in the in-memory inode,
4544 * initialise them to zero for new inodes. */
Mingming Cao617ba132006-10-11 01:20:53 -07004545 if (ei->i_state & EXT4_STATE_NEW)
4546 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004547
Jan Karaff9ddf72007-07-18 09:24:20 -04004548 ext4_get_inode_flags(ei);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004549 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004550 if (!(test_opt(inode->i_sb, NO_UID32))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004551 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
4552 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
4553/*
4554 * Fix up interoperability with old kernels. Otherwise, old inodes get
4555 * re-used with the upper 16 bits of the uid/gid intact
4556 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004557 if (!ei->i_dtime) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004558 raw_inode->i_uid_high =
4559 cpu_to_le16(high_16_bits(inode->i_uid));
4560 raw_inode->i_gid_high =
4561 cpu_to_le16(high_16_bits(inode->i_gid));
4562 } else {
4563 raw_inode->i_uid_high = 0;
4564 raw_inode->i_gid_high = 0;
4565 }
4566 } else {
4567 raw_inode->i_uid_low =
4568 cpu_to_le16(fs_high2lowuid(inode->i_uid));
4569 raw_inode->i_gid_low =
4570 cpu_to_le16(fs_high2lowgid(inode->i_gid));
4571 raw_inode->i_uid_high = 0;
4572 raw_inode->i_gid_high = 0;
4573 }
4574 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
Kalpak Shahef7f3832007-07-18 09:15:20 -04004575
4576 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4577 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4578 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4579 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4580
Aneesh Kumar K.V0fc1b452008-01-28 23:58:26 -05004581 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4582 goto out_brelse;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004583 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
Aneesh Kumar K.V267e4db2008-04-29 08:11:12 -04004584 /* clear the migrate flag in the raw_inode */
4585 raw_inode->i_flags = cpu_to_le32(ei->i_flags & ~EXT4_EXT_MIGRATE);
Mingming Cao9b8f1f02006-10-11 01:21:13 -07004586 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
4587 cpu_to_le32(EXT4_OS_HURD))
Badari Pulavartya1ddeb72006-10-11 01:21:09 -07004588 raw_inode->i_file_acl_high =
4589 cpu_to_le16(ei->i_file_acl >> 32);
Aneesh Kumar K.V7973c0c2008-01-28 23:58:27 -05004590 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004591 ext4_isize_set(raw_inode, ei->i_disksize);
4592 if (ei->i_disksize > 0x7fffffffULL) {
4593 struct super_block *sb = inode->i_sb;
4594 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4595 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4596 EXT4_SB(sb)->s_es->s_rev_level ==
4597 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4598 /* If this is the first large file
4599 * created, add a flag to the superblock.
4600 */
4601 err = ext4_journal_get_write_access(handle,
4602 EXT4_SB(sb)->s_sbh);
4603 if (err)
4604 goto out_brelse;
4605 ext4_update_dynamic_rev(sb);
4606 EXT4_SET_RO_COMPAT_FEATURE(sb,
Mingming Cao617ba132006-10-11 01:20:53 -07004607 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004608 sb->s_dirt = 1;
Frank Mayhar03901312009-01-07 00:06:22 -05004609 ext4_handle_sync(handle);
4610 err = ext4_handle_dirty_metadata(handle, inode,
Aneesh Kumar K.Va48380f2008-01-28 23:58:27 -05004611 EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004612 }
4613 }
4614 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4615 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4616 if (old_valid_dev(inode->i_rdev)) {
4617 raw_inode->i_block[0] =
4618 cpu_to_le32(old_encode_dev(inode->i_rdev));
4619 raw_inode->i_block[1] = 0;
4620 } else {
4621 raw_inode->i_block[0] = 0;
4622 raw_inode->i_block[1] =
4623 cpu_to_le32(new_encode_dev(inode->i_rdev));
4624 raw_inode->i_block[2] = 0;
4625 }
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004626 } else
4627 for (block = 0; block < EXT4_N_BLOCKS; block++)
4628 raw_inode->i_block[block] = ei->i_data[block];
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004629
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004630 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4631 if (ei->i_extra_isize) {
4632 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4633 raw_inode->i_version_hi =
4634 cpu_to_le32(inode->i_version >> 32);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004635 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004636 }
4637
Frank Mayhar03901312009-01-07 00:06:22 -05004638 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4639 rc = ext4_handle_dirty_metadata(handle, inode, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004640 if (!err)
4641 err = rc;
Mingming Cao617ba132006-10-11 01:20:53 -07004642 ei->i_state &= ~EXT4_STATE_NEW;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004643
4644out_brelse:
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04004645 brelse(bh);
Mingming Cao617ba132006-10-11 01:20:53 -07004646 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004647 return err;
4648}
4649
4650/*
Mingming Cao617ba132006-10-11 01:20:53 -07004651 * ext4_write_inode()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004652 *
4653 * We are called from a few places:
4654 *
4655 * - Within generic_file_write() for O_SYNC files.
4656 * Here, there will be no transaction running. We wait for any running
4657 * trasnaction to commit.
4658 *
4659 * - Within sys_sync(), kupdate and such.
4660 * We wait on commit, if tol to.
4661 *
4662 * - Within prune_icache() (PF_MEMALLOC == true)
4663 * Here we simply return. We can't afford to block kswapd on the
4664 * journal commit.
4665 *
4666 * In all cases it is actually safe for us to return without doing anything,
4667 * because the inode has been copied into a raw inode buffer in
Mingming Cao617ba132006-10-11 01:20:53 -07004668 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004669 * knfsd.
4670 *
4671 * Note that we are absolutely dependent upon all inode dirtiers doing the
4672 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4673 * which we are interested.
4674 *
4675 * It would be a bug for them to not do this. The code:
4676 *
4677 * mark_inode_dirty(inode)
4678 * stuff();
4679 * inode->i_size = expr;
4680 *
4681 * is in error because a kswapd-driven write_inode() could occur while
4682 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4683 * will no longer be on the superblock's dirty inode list.
4684 */
Mingming Cao617ba132006-10-11 01:20:53 -07004685int ext4_write_inode(struct inode *inode, int wait)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004686{
4687 if (current->flags & PF_MEMALLOC)
4688 return 0;
4689
Mingming Cao617ba132006-10-11 01:20:53 -07004690 if (ext4_journal_current_handle()) {
Mingming Caob38bd332007-07-19 01:48:35 -07004691 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004692 dump_stack();
4693 return -EIO;
4694 }
4695
4696 if (!wait)
4697 return 0;
4698
Mingming Cao617ba132006-10-11 01:20:53 -07004699 return ext4_force_commit(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004700}
4701
4702/*
Mingming Cao617ba132006-10-11 01:20:53 -07004703 * ext4_setattr()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004704 *
4705 * Called from notify_change.
4706 *
4707 * We want to trap VFS attempts to truncate the file as soon as
4708 * possible. In particular, we want to make sure that when the VFS
4709 * shrinks i_size, we put the inode on the orphan list and modify
4710 * i_disksize immediately, so that during the subsequent flushing of
4711 * dirty pages and freeing of disk blocks, we can guarantee that any
4712 * commit will leave the blocks being flushed in an unused state on
4713 * disk. (On recovery, the inode will get truncated and the blocks will
4714 * be freed, so we have a strong guarantee that no future commit will
4715 * leave these blocks visible to the user.)
4716 *
Jan Kara678aaf42008-07-11 19:27:31 -04004717 * Another thing we have to assure is that if we are in ordered mode
4718 * and inode is still attached to the committing transaction, we must
4719 * we start writeout of all the dirty pages which are being truncated.
4720 * This way we are sure that all the data written in the previous
4721 * transaction are already on disk (truncate waits for pages under
4722 * writeback).
4723 *
4724 * Called with inode->i_mutex down.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004725 */
Mingming Cao617ba132006-10-11 01:20:53 -07004726int ext4_setattr(struct dentry *dentry, struct iattr *attr)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004727{
4728 struct inode *inode = dentry->d_inode;
4729 int error, rc = 0;
4730 const unsigned int ia_valid = attr->ia_valid;
4731
4732 error = inode_change_ok(inode, attr);
4733 if (error)
4734 return error;
4735
4736 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
4737 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
4738 handle_t *handle;
4739
4740 /* (user+group)*(old+new) structure, inode write (sb,
4741 * inode block, ? - but truncate inode update has it) */
Mingming Cao617ba132006-10-11 01:20:53 -07004742 handle = ext4_journal_start(inode, 2*(EXT4_QUOTA_INIT_BLOCKS(inode->i_sb)+
4743 EXT4_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004744 if (IS_ERR(handle)) {
4745 error = PTR_ERR(handle);
4746 goto err_out;
4747 }
Jan Karaa269eb12009-01-26 17:04:39 +01004748 error = vfs_dq_transfer(inode, attr) ? -EDQUOT : 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004749 if (error) {
Mingming Cao617ba132006-10-11 01:20:53 -07004750 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004751 return error;
4752 }
4753 /* Update corresponding info in inode so that everything is in
4754 * one transaction */
4755 if (attr->ia_valid & ATTR_UID)
4756 inode->i_uid = attr->ia_uid;
4757 if (attr->ia_valid & ATTR_GID)
4758 inode->i_gid = attr->ia_gid;
Mingming Cao617ba132006-10-11 01:20:53 -07004759 error = ext4_mark_inode_dirty(handle, inode);
4760 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004761 }
4762
Eric Sandeene2b46572008-01-28 23:58:27 -05004763 if (attr->ia_valid & ATTR_SIZE) {
4764 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
4765 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4766
4767 if (attr->ia_size > sbi->s_bitmap_maxbytes) {
4768 error = -EFBIG;
4769 goto err_out;
4770 }
4771 }
4772 }
4773
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004774 if (S_ISREG(inode->i_mode) &&
4775 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
4776 handle_t *handle;
4777
Mingming Cao617ba132006-10-11 01:20:53 -07004778 handle = ext4_journal_start(inode, 3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004779 if (IS_ERR(handle)) {
4780 error = PTR_ERR(handle);
4781 goto err_out;
4782 }
4783
Mingming Cao617ba132006-10-11 01:20:53 -07004784 error = ext4_orphan_add(handle, inode);
4785 EXT4_I(inode)->i_disksize = attr->ia_size;
4786 rc = ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004787 if (!error)
4788 error = rc;
Mingming Cao617ba132006-10-11 01:20:53 -07004789 ext4_journal_stop(handle);
Jan Kara678aaf42008-07-11 19:27:31 -04004790
4791 if (ext4_should_order_data(inode)) {
4792 error = ext4_begin_ordered_truncate(inode,
4793 attr->ia_size);
4794 if (error) {
4795 /* Do as much error cleanup as possible */
4796 handle = ext4_journal_start(inode, 3);
4797 if (IS_ERR(handle)) {
4798 ext4_orphan_del(NULL, inode);
4799 goto err_out;
4800 }
4801 ext4_orphan_del(handle, inode);
4802 ext4_journal_stop(handle);
4803 goto err_out;
4804 }
4805 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004806 }
4807
4808 rc = inode_setattr(inode, attr);
4809
Mingming Cao617ba132006-10-11 01:20:53 -07004810 /* If inode_setattr's call to ext4_truncate failed to get a
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004811 * transaction handle at all, we need to clean up the in-core
4812 * orphan list manually. */
4813 if (inode->i_nlink)
Mingming Cao617ba132006-10-11 01:20:53 -07004814 ext4_orphan_del(NULL, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004815
4816 if (!rc && (ia_valid & ATTR_MODE))
Mingming Cao617ba132006-10-11 01:20:53 -07004817 rc = ext4_acl_chmod(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004818
4819err_out:
Mingming Cao617ba132006-10-11 01:20:53 -07004820 ext4_std_error(inode->i_sb, error);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004821 if (!error)
4822 error = rc;
4823 return error;
4824}
4825
Mingming Cao3e3398a2008-07-11 19:27:31 -04004826int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4827 struct kstat *stat)
4828{
4829 struct inode *inode;
4830 unsigned long delalloc_blocks;
4831
4832 inode = dentry->d_inode;
4833 generic_fillattr(inode, stat);
4834
4835 /*
4836 * We can't update i_blocks if the block allocation is delayed
4837 * otherwise in the case of system crash before the real block
4838 * allocation is done, we will have i_blocks inconsistent with
4839 * on-disk file blocks.
4840 * We always keep i_blocks updated together with real
4841 * allocation. But to not confuse with user, stat
4842 * will return the blocks that include the delayed allocation
4843 * blocks for this file.
4844 */
4845 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
4846 delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
4847 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
4848
4849 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
4850 return 0;
4851}
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004852
Mingming Caoa02908f2008-08-19 22:16:07 -04004853static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
4854 int chunk)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004855{
Mingming Caoa02908f2008-08-19 22:16:07 -04004856 int indirects;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004857
Mingming Caoa02908f2008-08-19 22:16:07 -04004858 /* if nrblocks are contiguous */
4859 if (chunk) {
4860 /*
4861 * With N contiguous data blocks, it need at most
4862 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
4863 * 2 dindirect blocks
4864 * 1 tindirect block
4865 */
4866 indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
4867 return indirects + 3;
4868 }
4869 /*
4870 * if nrblocks are not contiguous, worse case, each block touch
4871 * a indirect block, and each indirect block touch a double indirect
4872 * block, plus a triple indirect block
4873 */
4874 indirects = nrblocks * 2 + 1;
4875 return indirects;
4876}
Alex Tomasa86c6182006-10-11 01:21:03 -07004877
Mingming Caoa02908f2008-08-19 22:16:07 -04004878static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4879{
4880 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
Theodore Ts'oac51d832008-11-06 16:49:36 -05004881 return ext4_indirect_trans_blocks(inode, nrblocks, chunk);
4882 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
Mingming Caoa02908f2008-08-19 22:16:07 -04004883}
Theodore Ts'oac51d832008-11-06 16:49:36 -05004884
Mingming Caoa02908f2008-08-19 22:16:07 -04004885/*
4886 * Account for index blocks, block groups bitmaps and block group
4887 * descriptor blocks if modify datablocks and index blocks
4888 * worse case, the indexs blocks spread over different block groups
4889 *
4890 * If datablocks are discontiguous, they are possible to spread over
4891 * different block groups too. If they are contiugous, with flexbg,
4892 * they could still across block group boundary.
4893 *
4894 * Also account for superblock, inode, quota and xattr blocks
4895 */
4896int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4897{
Theodore Ts'o8df96752009-05-01 08:50:38 -04004898 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
4899 int gdpblocks;
Mingming Caoa02908f2008-08-19 22:16:07 -04004900 int idxblocks;
4901 int ret = 0;
4902
4903 /*
4904 * How many index blocks need to touch to modify nrblocks?
4905 * The "Chunk" flag indicating whether the nrblocks is
4906 * physically contiguous on disk
4907 *
4908 * For Direct IO and fallocate, they calls get_block to allocate
4909 * one single extent at a time, so they could set the "Chunk" flag
4910 */
4911 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
4912
4913 ret = idxblocks;
4914
4915 /*
4916 * Now let's see how many group bitmaps and group descriptors need
4917 * to account
4918 */
4919 groups = idxblocks;
4920 if (chunk)
4921 groups += 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004922 else
Mingming Caoa02908f2008-08-19 22:16:07 -04004923 groups += nrblocks;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004924
Mingming Caoa02908f2008-08-19 22:16:07 -04004925 gdpblocks = groups;
Theodore Ts'o8df96752009-05-01 08:50:38 -04004926 if (groups > ngroups)
4927 groups = ngroups;
Mingming Caoa02908f2008-08-19 22:16:07 -04004928 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
4929 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
4930
4931 /* bitmaps and block group descriptor blocks */
4932 ret += groups + gdpblocks;
4933
4934 /* Blocks for super block, inode, quota and xattr blocks */
4935 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004936
4937 return ret;
4938}
4939
4940/*
Mingming Caoa02908f2008-08-19 22:16:07 -04004941 * Calulate the total number of credits to reserve to fit
Mingming Caof3bd1f32008-08-19 22:16:03 -04004942 * the modification of a single pages into a single transaction,
4943 * which may include multiple chunks of block allocations.
Mingming Caoa02908f2008-08-19 22:16:07 -04004944 *
Mingming Cao525f4ed2008-08-19 22:15:58 -04004945 * This could be called via ext4_write_begin()
Mingming Caoa02908f2008-08-19 22:16:07 -04004946 *
Mingming Cao525f4ed2008-08-19 22:15:58 -04004947 * We need to consider the worse case, when
Mingming Caoa02908f2008-08-19 22:16:07 -04004948 * one new block per extent.
Mingming Caoa02908f2008-08-19 22:16:07 -04004949 */
4950int ext4_writepage_trans_blocks(struct inode *inode)
4951{
4952 int bpp = ext4_journal_blocks_per_page(inode);
4953 int ret;
4954
4955 ret = ext4_meta_trans_blocks(inode, bpp, 0);
4956
4957 /* Account for data blocks for journalled mode */
4958 if (ext4_should_journal_data(inode))
4959 ret += bpp;
4960 return ret;
4961}
Mingming Caof3bd1f32008-08-19 22:16:03 -04004962
4963/*
4964 * Calculate the journal credits for a chunk of data modification.
4965 *
4966 * This is called from DIO, fallocate or whoever calling
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04004967 * ext4_get_blocks() to map/allocate a chunk of contigous disk blocks.
Mingming Caof3bd1f32008-08-19 22:16:03 -04004968 *
4969 * journal buffers for data blocks are not included here, as DIO
4970 * and fallocate do no need to journal data buffers.
4971 */
4972int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
4973{
4974 return ext4_meta_trans_blocks(inode, nrblocks, 1);
4975}
4976
Mingming Caoa02908f2008-08-19 22:16:07 -04004977/*
Mingming Cao617ba132006-10-11 01:20:53 -07004978 * The caller must have previously called ext4_reserve_inode_write().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004979 * Give this, we know that the caller already has write access to iloc->bh.
4980 */
Mingming Cao617ba132006-10-11 01:20:53 -07004981int ext4_mark_iloc_dirty(handle_t *handle,
Theodore Ts'ode9a55b2009-06-14 17:45:34 -04004982 struct inode *inode, struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004983{
4984 int err = 0;
4985
Jean Noel Cordenner25ec56b2008-01-28 23:58:27 -05004986 if (test_opt(inode->i_sb, I_VERSION))
4987 inode_inc_iversion(inode);
4988
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004989 /* the do_update_inode consumes one bh->b_count */
4990 get_bh(iloc->bh);
4991
Mingming Caodab291a2006-10-11 01:21:01 -07004992 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
Mingming Cao617ba132006-10-11 01:20:53 -07004993 err = ext4_do_update_inode(handle, inode, iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07004994 put_bh(iloc->bh);
4995 return err;
4996}
4997
4998/*
4999 * On success, We end up with an outstanding reference count against
5000 * iloc->bh. This _must_ be cleaned up later.
5001 */
5002
5003int
Mingming Cao617ba132006-10-11 01:20:53 -07005004ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
5005 struct ext4_iloc *iloc)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005006{
Frank Mayhar03901312009-01-07 00:06:22 -05005007 int err;
5008
5009 err = ext4_get_inode_loc(inode, iloc);
5010 if (!err) {
5011 BUFFER_TRACE(iloc->bh, "get_write_access");
5012 err = ext4_journal_get_write_access(handle, iloc->bh);
5013 if (err) {
5014 brelse(iloc->bh);
5015 iloc->bh = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005016 }
5017 }
Mingming Cao617ba132006-10-11 01:20:53 -07005018 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005019 return err;
5020}
5021
5022/*
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005023 * Expand an inode by new_extra_isize bytes.
5024 * Returns 0 on success or negative error number on failure.
5025 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05005026static int ext4_expand_extra_isize(struct inode *inode,
5027 unsigned int new_extra_isize,
5028 struct ext4_iloc iloc,
5029 handle_t *handle)
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005030{
5031 struct ext4_inode *raw_inode;
5032 struct ext4_xattr_ibody_header *header;
5033 struct ext4_xattr_entry *entry;
5034
5035 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
5036 return 0;
5037
5038 raw_inode = ext4_raw_inode(&iloc);
5039
5040 header = IHDR(inode, raw_inode);
5041 entry = IFIRST(header);
5042
5043 /* No extended attributes present */
5044 if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) ||
5045 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
5046 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
5047 new_extra_isize);
5048 EXT4_I(inode)->i_extra_isize = new_extra_isize;
5049 return 0;
5050 }
5051
5052 /* try to expand with EAs present */
5053 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
5054 raw_inode, handle);
5055}
5056
5057/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005058 * What we do here is to mark the in-core inode as clean with respect to inode
5059 * dirtiness (it may still be data-dirty).
5060 * This means that the in-core inode may be reaped by prune_icache
5061 * without having to perform any I/O. This is a very good thing,
5062 * because *any* task may call prune_icache - even ones which
5063 * have a transaction open against a different journal.
5064 *
5065 * Is this cheating? Not really. Sure, we haven't written the
5066 * inode out, but prune_icache isn't a user-visible syncing function.
5067 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5068 * we start and wait on commits.
5069 *
5070 * Is this efficient/effective? Well, we're being nice to the system
5071 * by cleaning up our inodes proactively so they can be reaped
5072 * without I/O. But we are potentially leaving up to five seconds'
5073 * worth of inodes floating about which prune_icache wants us to
5074 * write out. One way to fix that would be to get prune_icache()
5075 * to do a write_super() to free up some memory. It has the desired
5076 * effect.
5077 */
Mingming Cao617ba132006-10-11 01:20:53 -07005078int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005079{
Mingming Cao617ba132006-10-11 01:20:53 -07005080 struct ext4_iloc iloc;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005081 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5082 static unsigned int mnt_count;
5083 int err, ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005084
5085 might_sleep();
Mingming Cao617ba132006-10-11 01:20:53 -07005086 err = ext4_reserve_inode_write(handle, inode, &iloc);
Frank Mayhar03901312009-01-07 00:06:22 -05005087 if (ext4_handle_valid(handle) &&
5088 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005089 !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {
5090 /*
5091 * We need extra buffer credits since we may write into EA block
5092 * with this same handle. If journal_extend fails, then it will
5093 * only result in a minor loss of functionality for that inode.
5094 * If this is felt to be critical, then e2fsck should be run to
5095 * force a large enough s_min_extra_isize.
5096 */
5097 if ((jbd2_journal_extend(handle,
5098 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
5099 ret = ext4_expand_extra_isize(inode,
5100 sbi->s_want_extra_isize,
5101 iloc, handle);
5102 if (ret) {
5103 EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
Aneesh Kumar K.Vc1bddad2007-10-16 18:38:25 -04005104 if (mnt_count !=
5105 le16_to_cpu(sbi->s_es->s_mnt_count)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04005106 ext4_warning(inode->i_sb, __func__,
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005107 "Unable to expand inode %lu. Delete"
5108 " some EAs or run e2fsck.",
5109 inode->i_ino);
Aneesh Kumar K.Vc1bddad2007-10-16 18:38:25 -04005110 mnt_count =
5111 le16_to_cpu(sbi->s_es->s_mnt_count);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04005112 }
5113 }
5114 }
5115 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005116 if (!err)
Mingming Cao617ba132006-10-11 01:20:53 -07005117 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005118 return err;
5119}
5120
5121/*
Mingming Cao617ba132006-10-11 01:20:53 -07005122 * ext4_dirty_inode() is called from __mark_inode_dirty()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005123 *
5124 * We're really interested in the case where a file is being extended.
5125 * i_size has been changed by generic_commit_write() and we thus need
5126 * to include the updated inode in the current transaction.
5127 *
Jan Karaa269eb12009-01-26 17:04:39 +01005128 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005129 * are allocated to the file.
5130 *
5131 * If the inode is marked synchronous, we don't honour that here - doing
5132 * so would cause a commit on atime updates, which we don't bother doing.
5133 * We handle synchronous inodes at the highest possible level.
5134 */
Mingming Cao617ba132006-10-11 01:20:53 -07005135void ext4_dirty_inode(struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005136{
Mingming Cao617ba132006-10-11 01:20:53 -07005137 handle_t *current_handle = ext4_journal_current_handle();
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005138 handle_t *handle;
5139
Frank Mayhar03901312009-01-07 00:06:22 -05005140 if (!ext4_handle_valid(current_handle)) {
5141 ext4_mark_inode_dirty(current_handle, inode);
5142 return;
5143 }
5144
Mingming Cao617ba132006-10-11 01:20:53 -07005145 handle = ext4_journal_start(inode, 2);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005146 if (IS_ERR(handle))
5147 goto out;
5148 if (current_handle &&
5149 current_handle->h_transaction != handle->h_transaction) {
5150 /* This task has a transaction open against a different fs */
5151 printk(KERN_EMERG "%s: transactions do not match!\n",
Harvey Harrison46e665e2008-04-17 10:38:59 -04005152 __func__);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005153 } else {
5154 jbd_debug(5, "marking dirty. outer handle=%p\n",
5155 current_handle);
Mingming Cao617ba132006-10-11 01:20:53 -07005156 ext4_mark_inode_dirty(handle, inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005157 }
Mingming Cao617ba132006-10-11 01:20:53 -07005158 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005159out:
5160 return;
5161}
5162
5163#if 0
5164/*
5165 * Bind an inode's backing buffer_head into this transaction, to prevent
5166 * it from being flushed to disk early. Unlike
Mingming Cao617ba132006-10-11 01:20:53 -07005167 * ext4_reserve_inode_write, this leaves behind no bh reference and
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005168 * returns no iloc structure, so the caller needs to repeat the iloc
5169 * lookup to mark the inode dirty later.
5170 */
Mingming Cao617ba132006-10-11 01:20:53 -07005171static int ext4_pin_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005172{
Mingming Cao617ba132006-10-11 01:20:53 -07005173 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005174
5175 int err = 0;
5176 if (handle) {
Mingming Cao617ba132006-10-11 01:20:53 -07005177 err = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005178 if (!err) {
5179 BUFFER_TRACE(iloc.bh, "get_write_access");
Mingming Caodab291a2006-10-11 01:21:01 -07005180 err = jbd2_journal_get_write_access(handle, iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005181 if (!err)
Frank Mayhar03901312009-01-07 00:06:22 -05005182 err = ext4_handle_dirty_metadata(handle,
5183 inode,
5184 iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005185 brelse(iloc.bh);
5186 }
5187 }
Mingming Cao617ba132006-10-11 01:20:53 -07005188 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005189 return err;
5190}
5191#endif
5192
Mingming Cao617ba132006-10-11 01:20:53 -07005193int ext4_change_inode_journal_flag(struct inode *inode, int val)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005194{
5195 journal_t *journal;
5196 handle_t *handle;
5197 int err;
5198
5199 /*
5200 * We have to be very careful here: changing a data block's
5201 * journaling status dynamically is dangerous. If we write a
5202 * data block to the journal, change the status and then delete
5203 * that block, we risk forgetting to revoke the old log record
5204 * from the journal and so a subsequent replay can corrupt data.
5205 * So, first we make sure that the journal is empty and that
5206 * nobody is changing anything.
5207 */
5208
Mingming Cao617ba132006-10-11 01:20:53 -07005209 journal = EXT4_JOURNAL(inode);
Frank Mayhar03901312009-01-07 00:06:22 -05005210 if (!journal)
5211 return 0;
Dave Hansend6995942007-07-18 08:33:51 -04005212 if (is_journal_aborted(journal))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005213 return -EROFS;
5214
Mingming Caodab291a2006-10-11 01:21:01 -07005215 jbd2_journal_lock_updates(journal);
5216 jbd2_journal_flush(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005217
5218 /*
5219 * OK, there are no updates running now, and all cached data is
5220 * synced to disk. We are now in a completely consistent state
5221 * which doesn't have anything in the journal, and we know that
5222 * no filesystem updates are running, so it is safe to modify
5223 * the inode's in-core data-journaling state flag now.
5224 */
5225
5226 if (val)
Mingming Cao617ba132006-10-11 01:20:53 -07005227 EXT4_I(inode)->i_flags |= EXT4_JOURNAL_DATA_FL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005228 else
Mingming Cao617ba132006-10-11 01:20:53 -07005229 EXT4_I(inode)->i_flags &= ~EXT4_JOURNAL_DATA_FL;
5230 ext4_set_aops(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005231
Mingming Caodab291a2006-10-11 01:21:01 -07005232 jbd2_journal_unlock_updates(journal);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005233
5234 /* Finally we can mark the inode as dirty. */
5235
Mingming Cao617ba132006-10-11 01:20:53 -07005236 handle = ext4_journal_start(inode, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005237 if (IS_ERR(handle))
5238 return PTR_ERR(handle);
5239
Mingming Cao617ba132006-10-11 01:20:53 -07005240 err = ext4_mark_inode_dirty(handle, inode);
Frank Mayhar03901312009-01-07 00:06:22 -05005241 ext4_handle_sync(handle);
Mingming Cao617ba132006-10-11 01:20:53 -07005242 ext4_journal_stop(handle);
5243 ext4_std_error(inode->i_sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005244
5245 return err;
5246}
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005247
5248static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
5249{
5250 return !buffer_mapped(bh);
5251}
5252
Nick Pigginc2ec1752009-03-31 15:23:21 -07005253int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005254{
Nick Pigginc2ec1752009-03-31 15:23:21 -07005255 struct page *page = vmf->page;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005256 loff_t size;
5257 unsigned long len;
5258 int ret = -EINVAL;
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005259 void *fsdata;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005260 struct file *file = vma->vm_file;
5261 struct inode *inode = file->f_path.dentry->d_inode;
5262 struct address_space *mapping = inode->i_mapping;
5263
5264 /*
5265 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5266 * get i_mutex because we are already holding mmap_sem.
5267 */
5268 down_read(&inode->i_alloc_sem);
5269 size = i_size_read(inode);
5270 if (page->mapping != mapping || size <= page_offset(page)
5271 || !PageUptodate(page)) {
5272 /* page got truncated from under us? */
5273 goto out_unlock;
5274 }
5275 ret = 0;
5276 if (PageMappedToDisk(page))
5277 goto out_unlock;
5278
5279 if (page->index == size >> PAGE_CACHE_SHIFT)
5280 len = size & ~PAGE_CACHE_MASK;
5281 else
5282 len = PAGE_CACHE_SIZE;
5283
5284 if (page_has_buffers(page)) {
5285 /* return if we have all the buffers mapped */
5286 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
5287 ext4_bh_unmapped))
5288 goto out_unlock;
5289 }
5290 /*
5291 * OK, we need to fill the hole... Do write_begin write_end
5292 * to do block allocation/reservation.We are not holding
5293 * inode.i__mutex here. That allow * parallel write_begin,
5294 * write_end call. lock_page prevent this from happening
5295 * on the same page though
5296 */
5297 ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005298 len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005299 if (ret < 0)
5300 goto out_unlock;
5301 ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
Aneesh Kumar K.V79f0be82008-10-08 23:13:30 -04005302 len, len, page, fsdata);
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005303 if (ret < 0)
5304 goto out_unlock;
5305 ret = 0;
5306out_unlock:
Nick Pigginc2ec1752009-03-31 15:23:21 -07005307 if (ret)
5308 ret = VM_FAULT_SIGBUS;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -04005309 up_read(&inode->i_alloc_sem);
5310 return ret;
5311}