2 * linux/fs/ext4/inode.c
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)
11 * linux/fs/minix/inode.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
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)
22 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
25 #include <linux/module.h>
27 #include <linux/time.h>
28 #include <linux/jbd2.h>
29 #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>
35 #include <linux/pagevec.h>
36 #include <linux/mpage.h>
37 #include <linux/namei.h>
38 #include <linux/uio.h>
39 #include <linux/bio.h>
40 #include "ext4_jbd2.h"
43 #include "ext4_extents.h"
45 #define MPAGE_DA_EXTENT_TAIL 0x01
47 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
50 return jbd2_journal_begin_ordered_truncate(
51 EXT4_SB(inode
->i_sb
)->s_journal
,
52 &EXT4_I(inode
)->jinode
,
56 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
59 * Test whether an inode is a fast symlink.
61 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
63 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
64 (inode
->i_sb
->s_blocksize
>> 9) : 0;
66 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
70 * The ext4 forget function must perform a revoke if we are freeing data
71 * which has been journaled. Metadata (eg. indirect blocks) must be
72 * revoked in all cases.
74 * "bh" may be NULL: a metadata block may have been freed from memory
75 * but there may still be a record of it in the journal, and that record
76 * still needs to be revoked.
78 * If the handle isn't valid we're not journaling so there's nothing to do.
80 int ext4_forget(handle_t
*handle
, int is_metadata
, struct inode
*inode
,
81 struct buffer_head
*bh
, ext4_fsblk_t blocknr
)
85 if (!ext4_handle_valid(handle
))
90 BUFFER_TRACE(bh
, "enter");
92 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
94 bh
, is_metadata
, inode
->i_mode
,
95 test_opt(inode
->i_sb
, DATA_FLAGS
));
97 /* Never use the revoke function if we are doing full data
98 * journaling: there is no need to, and a V1 superblock won't
99 * support it. Otherwise, only skip the revoke on un-journaled
102 if (test_opt(inode
->i_sb
, DATA_FLAGS
) == EXT4_MOUNT_JOURNAL_DATA
||
103 (!is_metadata
&& !ext4_should_journal_data(inode
))) {
105 BUFFER_TRACE(bh
, "call jbd2_journal_forget");
106 return ext4_journal_forget(handle
, bh
);
112 * data!=journal && (is_metadata || should_journal_data(inode))
114 BUFFER_TRACE(bh
, "call ext4_journal_revoke");
115 err
= ext4_journal_revoke(handle
, blocknr
, bh
);
117 ext4_abort(inode
->i_sb
, __func__
,
118 "error %d when attempting revoke", err
);
119 BUFFER_TRACE(bh
, "exit");
124 * Work out how many blocks we need to proceed with the next chunk of a
125 * truncate transaction.
127 static unsigned long blocks_for_truncate(struct inode
*inode
)
131 needed
= inode
->i_blocks
>> (inode
->i_sb
->s_blocksize_bits
- 9);
133 /* Give ourselves just enough room to cope with inodes in which
134 * i_blocks is corrupt: we've seen disk corruptions in the past
135 * which resulted in random data in an inode which looked enough
136 * like a regular file for ext4 to try to delete it. Things
137 * will go a bit crazy if that happens, but at least we should
138 * try not to panic the whole kernel. */
142 /* But we need to bound the transaction so we don't overflow the
144 if (needed
> EXT4_MAX_TRANS_DATA
)
145 needed
= EXT4_MAX_TRANS_DATA
;
147 return EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + needed
;
151 * Truncate transactions can be complex and absolutely huge. So we need to
152 * be able to restart the transaction at a conventient checkpoint to make
153 * sure we don't overflow the journal.
155 * start_transaction gets us a new handle for a truncate transaction,
156 * and extend_transaction tries to extend the existing one a bit. If
157 * extend fails, we need to propagate the failure up and restart the
158 * transaction in the top-level truncate loop. --sct
160 static handle_t
*start_transaction(struct inode
*inode
)
164 result
= ext4_journal_start(inode
, blocks_for_truncate(inode
));
168 ext4_std_error(inode
->i_sb
, PTR_ERR(result
));
173 * Try to extend this transaction for the purposes of truncation.
175 * Returns 0 if we managed to create more room. If we can't create more
176 * room, and the transaction must be restarted we return 1.
178 static int try_to_extend_transaction(handle_t
*handle
, struct inode
*inode
)
180 if (!ext4_handle_valid(handle
))
182 if (ext4_handle_has_enough_credits(handle
, EXT4_RESERVE_TRANS_BLOCKS
+1))
184 if (!ext4_journal_extend(handle
, blocks_for_truncate(inode
)))
190 * Restart the transaction associated with *handle. This does a commit,
191 * so before we call here everything must be consistently dirtied against
194 static int ext4_journal_test_restart(handle_t
*handle
, struct inode
*inode
)
196 BUG_ON(EXT4_JOURNAL(inode
) == NULL
);
197 jbd_debug(2, "restarting handle %p\n", handle
);
198 return ext4_journal_restart(handle
, blocks_for_truncate(inode
));
202 * Called at the last iput() if i_nlink is zero.
204 void ext4_delete_inode(struct inode
*inode
)
209 if (ext4_should_order_data(inode
))
210 ext4_begin_ordered_truncate(inode
, 0);
211 truncate_inode_pages(&inode
->i_data
, 0);
213 if (is_bad_inode(inode
))
216 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
217 if (IS_ERR(handle
)) {
218 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
220 * If we're going to skip the normal cleanup, we still need to
221 * make sure that the in-core orphan linked list is properly
224 ext4_orphan_del(NULL
, inode
);
229 ext4_handle_sync(handle
);
231 err
= ext4_mark_inode_dirty(handle
, inode
);
233 ext4_warning(inode
->i_sb
, __func__
,
234 "couldn't mark inode dirty (err %d)", err
);
238 ext4_truncate(inode
);
241 * ext4_ext_truncate() doesn't reserve any slop when it
242 * restarts journal transactions; therefore there may not be
243 * enough credits left in the handle to remove the inode from
244 * the orphan list and set the dtime field.
246 if (!ext4_handle_has_enough_credits(handle
, 3)) {
247 err
= ext4_journal_extend(handle
, 3);
249 err
= ext4_journal_restart(handle
, 3);
251 ext4_warning(inode
->i_sb
, __func__
,
252 "couldn't extend journal (err %d)", err
);
254 ext4_journal_stop(handle
);
260 * Kill off the orphan record which ext4_truncate created.
261 * AKPM: I think this can be inside the above `if'.
262 * Note that ext4_orphan_del() has to be able to cope with the
263 * deletion of a non-existent orphan - this is because we don't
264 * know if ext4_truncate() actually created an orphan record.
265 * (Well, we could do this if we need to, but heck - it works)
267 ext4_orphan_del(handle
, inode
);
268 EXT4_I(inode
)->i_dtime
= get_seconds();
271 * One subtle ordering requirement: if anything has gone wrong
272 * (transaction abort, IO errors, whatever), then we can still
273 * do these next steps (the fs will already have been marked as
274 * having errors), but we can't free the inode if the mark_dirty
277 if (ext4_mark_inode_dirty(handle
, inode
))
278 /* If that failed, just do the required in-core inode clear. */
281 ext4_free_inode(handle
, inode
);
282 ext4_journal_stop(handle
);
285 clear_inode(inode
); /* We must guarantee clearing of inode... */
291 struct buffer_head
*bh
;
294 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
296 p
->key
= *(p
->p
= v
);
301 * ext4_block_to_path - parse the block number into array of offsets
302 * @inode: inode in question (we are only interested in its superblock)
303 * @i_block: block number to be parsed
304 * @offsets: array to store the offsets in
305 * @boundary: set this non-zero if the referred-to block is likely to be
306 * followed (on disk) by an indirect block.
308 * To store the locations of file's data ext4 uses a data structure common
309 * for UNIX filesystems - tree of pointers anchored in the inode, with
310 * data blocks at leaves and indirect blocks in intermediate nodes.
311 * This function translates the block number into path in that tree -
312 * return value is the path length and @offsets[n] is the offset of
313 * pointer to (n+1)th node in the nth one. If @block is out of range
314 * (negative or too large) warning is printed and zero returned.
316 * Note: function doesn't find node addresses, so no IO is needed. All
317 * we need to know is the capacity of indirect blocks (taken from the
322 * Portability note: the last comparison (check that we fit into triple
323 * indirect block) is spelled differently, because otherwise on an
324 * architecture with 32-bit longs and 8Kb pages we might get into trouble
325 * if our filesystem had 8Kb blocks. We might use long long, but that would
326 * kill us on x86. Oh, well, at least the sign propagation does not matter -
327 * i_block would have to be negative in the very beginning, so we would not
331 static int ext4_block_to_path(struct inode
*inode
,
333 ext4_lblk_t offsets
[4], int *boundary
)
335 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
336 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
337 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
338 indirect_blocks
= ptrs
,
339 double_blocks
= (1 << (ptrs_bits
* 2));
344 ext4_warning(inode
->i_sb
, "ext4_block_to_path", "block < 0");
345 } else if (i_block
< direct_blocks
) {
346 offsets
[n
++] = i_block
;
347 final
= direct_blocks
;
348 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
349 offsets
[n
++] = EXT4_IND_BLOCK
;
350 offsets
[n
++] = i_block
;
352 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
353 offsets
[n
++] = EXT4_DIND_BLOCK
;
354 offsets
[n
++] = i_block
>> ptrs_bits
;
355 offsets
[n
++] = i_block
& (ptrs
- 1);
357 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
358 offsets
[n
++] = EXT4_TIND_BLOCK
;
359 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
360 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
361 offsets
[n
++] = i_block
& (ptrs
- 1);
364 ext4_warning(inode
->i_sb
, "ext4_block_to_path",
365 "block %lu > max in inode %lu",
366 i_block
+ direct_blocks
+
367 indirect_blocks
+ double_blocks
, inode
->i_ino
);
370 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
375 * ext4_get_branch - read the chain of indirect blocks leading to data
376 * @inode: inode in question
377 * @depth: depth of the chain (1 - direct pointer, etc.)
378 * @offsets: offsets of pointers in inode/indirect blocks
379 * @chain: place to store the result
380 * @err: here we store the error value
382 * Function fills the array of triples <key, p, bh> and returns %NULL
383 * if everything went OK or the pointer to the last filled triple
384 * (incomplete one) otherwise. Upon the return chain[i].key contains
385 * the number of (i+1)-th block in the chain (as it is stored in memory,
386 * i.e. little-endian 32-bit), chain[i].p contains the address of that
387 * number (it points into struct inode for i==0 and into the bh->b_data
388 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
389 * block for i>0 and NULL for i==0. In other words, it holds the block
390 * numbers of the chain, addresses they were taken from (and where we can
391 * verify that chain did not change) and buffer_heads hosting these
394 * Function stops when it stumbles upon zero pointer (absent block)
395 * (pointer to last triple returned, *@err == 0)
396 * or when it gets an IO error reading an indirect block
397 * (ditto, *@err == -EIO)
398 * or when it reads all @depth-1 indirect blocks successfully and finds
399 * the whole chain, all way to the data (returns %NULL, *err == 0).
401 * Need to be called with
402 * down_read(&EXT4_I(inode)->i_data_sem)
404 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
405 ext4_lblk_t
*offsets
,
406 Indirect chain
[4], int *err
)
408 struct super_block
*sb
= inode
->i_sb
;
410 struct buffer_head
*bh
;
413 /* i_data is not going away, no lock needed */
414 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
418 bh
= sb_bread(sb
, le32_to_cpu(p
->key
));
421 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
435 * ext4_find_near - find a place for allocation with sufficient locality
437 * @ind: descriptor of indirect block.
439 * This function returns the preferred place for block allocation.
440 * It is used when heuristic for sequential allocation fails.
442 * + if there is a block to the left of our position - allocate near it.
443 * + if pointer will live in indirect block - allocate near that block.
444 * + if pointer will live in inode - allocate in the same
447 * In the latter case we colour the starting block by the callers PID to
448 * prevent it from clashing with concurrent allocations for a different inode
449 * in the same block group. The PID is used here so that functionally related
450 * files will be close-by on-disk.
452 * Caller must make sure that @ind is valid and will stay that way.
454 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
456 struct ext4_inode_info
*ei
= EXT4_I(inode
);
457 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
459 ext4_fsblk_t bg_start
;
460 ext4_fsblk_t last_block
;
461 ext4_grpblk_t colour
;
463 /* Try to find previous block */
464 for (p
= ind
->p
- 1; p
>= start
; p
--) {
466 return le32_to_cpu(*p
);
469 /* No such thing, so let's try location of indirect block */
471 return ind
->bh
->b_blocknr
;
474 * It is going to be referred to from the inode itself? OK, just put it
475 * into the same cylinder group then.
477 bg_start
= ext4_group_first_block_no(inode
->i_sb
, ei
->i_block_group
);
478 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
480 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
481 colour
= (current
->pid
% 16) *
482 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
484 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
485 return bg_start
+ colour
;
489 * ext4_find_goal - find a preferred place for allocation.
491 * @block: block we want
492 * @partial: pointer to the last triple within a chain
494 * Normally this function find the preferred place for block allocation,
497 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
501 * XXX need to get goal block from mballoc's data structures
504 return ext4_find_near(inode
, partial
);
508 * ext4_blks_to_allocate: Look up the block map and count the number
509 * of direct blocks need to be allocated for the given branch.
511 * @branch: chain of indirect blocks
512 * @k: number of blocks need for indirect blocks
513 * @blks: number of data blocks to be mapped.
514 * @blocks_to_boundary: the offset in the indirect block
516 * return the total number of blocks to be allocate, including the
517 * direct and indirect blocks.
519 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned int blks
,
520 int blocks_to_boundary
)
522 unsigned int count
= 0;
525 * Simple case, [t,d]Indirect block(s) has not allocated yet
526 * then it's clear blocks on that path have not allocated
529 /* right now we don't handle cross boundary allocation */
530 if (blks
< blocks_to_boundary
+ 1)
533 count
+= blocks_to_boundary
+ 1;
538 while (count
< blks
&& count
<= blocks_to_boundary
&&
539 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
546 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
547 * @indirect_blks: the number of blocks need to allocate for indirect
550 * @new_blocks: on return it will store the new block numbers for
551 * the indirect blocks(if needed) and the first direct block,
552 * @blks: on return it will store the total number of allocated
555 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
556 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
557 int indirect_blks
, int blks
,
558 ext4_fsblk_t new_blocks
[4], int *err
)
560 struct ext4_allocation_request ar
;
562 unsigned long count
= 0, blk_allocated
= 0;
564 ext4_fsblk_t current_block
= 0;
568 * Here we try to allocate the requested multiple blocks at once,
569 * on a best-effort basis.
570 * To build a branch, we should allocate blocks for
571 * the indirect blocks(if not allocated yet), and at least
572 * the first direct block of this branch. That's the
573 * minimum number of blocks need to allocate(required)
575 /* first we try to allocate the indirect blocks */
576 target
= indirect_blks
;
579 /* allocating blocks for indirect blocks and direct blocks */
580 current_block
= ext4_new_meta_blocks(handle
, inode
,
586 /* allocate blocks for indirect blocks */
587 while (index
< indirect_blks
&& count
) {
588 new_blocks
[index
++] = current_block
++;
593 * save the new block number
594 * for the first direct block
596 new_blocks
[index
] = current_block
;
597 printk(KERN_INFO
"%s returned more blocks than "
598 "requested\n", __func__
);
604 target
= blks
- count
;
605 blk_allocated
= count
;
608 /* Now allocate data blocks */
609 memset(&ar
, 0, sizeof(ar
));
614 if (S_ISREG(inode
->i_mode
))
615 /* enable in-core preallocation only for regular files */
616 ar
.flags
= EXT4_MB_HINT_DATA
;
618 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
620 if (*err
&& (target
== blks
)) {
622 * if the allocation failed and we didn't allocate
628 if (target
== blks
) {
630 * save the new block number
631 * for the first direct block
633 new_blocks
[index
] = current_block
;
635 blk_allocated
+= ar
.len
;
638 /* total number of blocks allocated for direct blocks */
643 for (i
= 0; i
< index
; i
++)
644 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
649 * ext4_alloc_branch - allocate and set up a chain of blocks.
651 * @indirect_blks: number of allocated indirect blocks
652 * @blks: number of allocated direct blocks
653 * @offsets: offsets (in the blocks) to store the pointers to next.
654 * @branch: place to store the chain in.
656 * This function allocates blocks, zeroes out all but the last one,
657 * links them into chain and (if we are synchronous) writes them to disk.
658 * In other words, it prepares a branch that can be spliced onto the
659 * inode. It stores the information about that chain in the branch[], in
660 * the same format as ext4_get_branch() would do. We are calling it after
661 * we had read the existing part of chain and partial points to the last
662 * triple of that (one with zero ->key). Upon the exit we have the same
663 * picture as after the successful ext4_get_block(), except that in one
664 * place chain is disconnected - *branch->p is still zero (we did not
665 * set the last link), but branch->key contains the number that should
666 * be placed into *branch->p to fill that gap.
668 * If allocation fails we free all blocks we've allocated (and forget
669 * their buffer_heads) and return the error value the from failed
670 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
671 * as described above and return 0.
673 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
674 ext4_lblk_t iblock
, int indirect_blks
,
675 int *blks
, ext4_fsblk_t goal
,
676 ext4_lblk_t
*offsets
, Indirect
*branch
)
678 int blocksize
= inode
->i_sb
->s_blocksize
;
681 struct buffer_head
*bh
;
683 ext4_fsblk_t new_blocks
[4];
684 ext4_fsblk_t current_block
;
686 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
687 *blks
, new_blocks
, &err
);
691 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
693 * metadata blocks and data blocks are allocated.
695 for (n
= 1; n
<= indirect_blks
; n
++) {
697 * Get buffer_head for parent block, zero it out
698 * and set the pointer to new one, then send
701 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
704 BUFFER_TRACE(bh
, "call get_create_access");
705 err
= ext4_journal_get_create_access(handle
, bh
);
712 memset(bh
->b_data
, 0, blocksize
);
713 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
714 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
715 *branch
[n
].p
= branch
[n
].key
;
716 if (n
== indirect_blks
) {
717 current_block
= new_blocks
[n
];
719 * End of chain, update the last new metablock of
720 * the chain to point to the new allocated
721 * data blocks numbers
723 for (i
=1; i
< num
; i
++)
724 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
726 BUFFER_TRACE(bh
, "marking uptodate");
727 set_buffer_uptodate(bh
);
730 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
731 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
738 /* Allocation failed, free what we already allocated */
739 for (i
= 1; i
<= n
; i
++) {
740 BUFFER_TRACE(branch
[i
].bh
, "call jbd2_journal_forget");
741 ext4_journal_forget(handle
, branch
[i
].bh
);
743 for (i
= 0; i
< indirect_blks
; i
++)
744 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
746 ext4_free_blocks(handle
, inode
, new_blocks
[i
], num
, 0);
752 * ext4_splice_branch - splice the allocated branch onto inode.
754 * @block: (logical) number of block we are adding
755 * @chain: chain of indirect blocks (with a missing link - see
757 * @where: location of missing link
758 * @num: number of indirect blocks we are adding
759 * @blks: number of direct blocks we are adding
761 * This function fills the missing link and does all housekeeping needed in
762 * inode (->i_blocks, etc.). In case of success we end up with the full
763 * chain to new block and return 0.
765 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
766 ext4_lblk_t block
, Indirect
*where
, int num
, int blks
)
770 ext4_fsblk_t current_block
;
773 * If we're splicing into a [td]indirect block (as opposed to the
774 * inode) then we need to get write access to the [td]indirect block
778 BUFFER_TRACE(where
->bh
, "get_write_access");
779 err
= ext4_journal_get_write_access(handle
, where
->bh
);
785 *where
->p
= where
->key
;
788 * Update the host buffer_head or inode to point to more just allocated
789 * direct blocks blocks
791 if (num
== 0 && blks
> 1) {
792 current_block
= le32_to_cpu(where
->key
) + 1;
793 for (i
= 1; i
< blks
; i
++)
794 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
797 /* We are done with atomic stuff, now do the rest of housekeeping */
799 inode
->i_ctime
= ext4_current_time(inode
);
800 ext4_mark_inode_dirty(handle
, inode
);
802 /* had we spliced it onto indirect block? */
805 * If we spliced it onto an indirect block, we haven't
806 * altered the inode. Note however that if it is being spliced
807 * onto an indirect block at the very end of the file (the
808 * file is growing) then we *will* alter the inode to reflect
809 * the new i_size. But that is not done here - it is done in
810 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
812 jbd_debug(5, "splicing indirect only\n");
813 BUFFER_TRACE(where
->bh
, "call ext4_handle_dirty_metadata");
814 err
= ext4_handle_dirty_metadata(handle
, inode
, where
->bh
);
819 * OK, we spliced it into the inode itself on a direct block.
820 * Inode was dirtied above.
822 jbd_debug(5, "splicing direct\n");
827 for (i
= 1; i
<= num
; i
++) {
828 BUFFER_TRACE(where
[i
].bh
, "call jbd2_journal_forget");
829 ext4_journal_forget(handle
, where
[i
].bh
);
830 ext4_free_blocks(handle
, inode
,
831 le32_to_cpu(where
[i
-1].key
), 1, 0);
833 ext4_free_blocks(handle
, inode
, le32_to_cpu(where
[num
].key
), blks
, 0);
839 * Allocation strategy is simple: if we have to allocate something, we will
840 * have to go the whole way to leaf. So let's do it before attaching anything
841 * to tree, set linkage between the newborn blocks, write them if sync is
842 * required, recheck the path, free and repeat if check fails, otherwise
843 * set the last missing link (that will protect us from any truncate-generated
844 * removals - all blocks on the path are immune now) and possibly force the
845 * write on the parent block.
846 * That has a nice additional property: no special recovery from the failed
847 * allocations is needed - we simply release blocks and do not touch anything
848 * reachable from inode.
850 * `handle' can be NULL if create == 0.
852 * return > 0, # of blocks mapped or allocated.
853 * return = 0, if plain lookup failed.
854 * return < 0, error case.
857 * Need to be called with
858 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
859 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
861 static int ext4_get_blocks_handle(handle_t
*handle
, struct inode
*inode
,
862 ext4_lblk_t iblock
, unsigned int maxblocks
,
863 struct buffer_head
*bh_result
,
864 int create
, int extend_disksize
)
867 ext4_lblk_t offsets
[4];
872 int blocks_to_boundary
= 0;
874 struct ext4_inode_info
*ei
= EXT4_I(inode
);
876 ext4_fsblk_t first_block
= 0;
880 J_ASSERT(!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
));
881 J_ASSERT(handle
!= NULL
|| create
== 0);
882 depth
= ext4_block_to_path(inode
, iblock
, offsets
,
883 &blocks_to_boundary
);
888 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
890 /* Simplest case - block found, no allocation needed */
892 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
893 clear_buffer_new(bh_result
);
896 while (count
< maxblocks
&& count
<= blocks_to_boundary
) {
899 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
901 if (blk
== first_block
+ count
)
909 /* Next simple case - plain lookup or failed read of indirect block */
910 if (!create
|| err
== -EIO
)
914 * Okay, we need to do block allocation.
916 goal
= ext4_find_goal(inode
, iblock
, partial
);
918 /* the number of blocks need to allocate for [d,t]indirect blocks */
919 indirect_blks
= (chain
+ depth
) - partial
- 1;
922 * Next look up the indirect map to count the totoal number of
923 * direct blocks to allocate for this branch.
925 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
926 maxblocks
, blocks_to_boundary
);
928 * Block out ext4_truncate while we alter the tree
930 err
= ext4_alloc_branch(handle
, inode
, iblock
, indirect_blks
,
932 offsets
+ (partial
- chain
), partial
);
935 * The ext4_splice_branch call will free and forget any buffers
936 * on the new chain if there is a failure, but that risks using
937 * up transaction credits, especially for bitmaps where the
938 * credits cannot be returned. Can we handle this somehow? We
939 * may need to return -EAGAIN upwards in the worst case. --sct
942 err
= ext4_splice_branch(handle
, inode
, iblock
,
943 partial
, indirect_blks
, count
);
945 * i_disksize growing is protected by i_data_sem. Don't forget to
946 * protect it if you're about to implement concurrent
947 * ext4_get_block() -bzzz
949 if (!err
&& extend_disksize
) {
950 disksize
= ((loff_t
) iblock
+ count
) << inode
->i_blkbits
;
951 if (disksize
> i_size_read(inode
))
952 disksize
= i_size_read(inode
);
953 if (disksize
> ei
->i_disksize
)
954 ei
->i_disksize
= disksize
;
959 set_buffer_new(bh_result
);
961 map_bh(bh_result
, inode
->i_sb
, le32_to_cpu(chain
[depth
-1].key
));
962 if (count
> blocks_to_boundary
)
963 set_buffer_boundary(bh_result
);
965 /* Clean up and exit */
966 partial
= chain
+ depth
- 1; /* the whole chain */
968 while (partial
> chain
) {
969 BUFFER_TRACE(partial
->bh
, "call brelse");
973 BUFFER_TRACE(bh_result
, "returned");
979 * Calculate the number of metadata blocks need to reserve
980 * to allocate @blocks for non extent file based file
982 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
, int blocks
)
984 int icap
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
985 int ind_blks
, dind_blks
, tind_blks
;
987 /* number of new indirect blocks needed */
988 ind_blks
= (blocks
+ icap
- 1) / icap
;
990 dind_blks
= (ind_blks
+ icap
- 1) / icap
;
994 return ind_blks
+ dind_blks
+ tind_blks
;
998 * Calculate the number of metadata blocks need to reserve
999 * to allocate given number of blocks
1001 static int ext4_calc_metadata_amount(struct inode
*inode
, int blocks
)
1006 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
1007 return ext4_ext_calc_metadata_amount(inode
, blocks
);
1009 return ext4_indirect_calc_metadata_amount(inode
, blocks
);
1012 static void ext4_da_update_reserve_space(struct inode
*inode
, int used
)
1014 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1015 int total
, mdb
, mdb_free
;
1017 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1018 /* recalculate the number of metablocks still need to be reserved */
1019 total
= EXT4_I(inode
)->i_reserved_data_blocks
- used
;
1020 mdb
= ext4_calc_metadata_amount(inode
, total
);
1022 /* figure out how many metablocks to release */
1023 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1024 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1027 /* Account for allocated meta_blocks */
1028 mdb_free
-= EXT4_I(inode
)->i_allocated_meta_blocks
;
1030 /* update fs dirty blocks counter */
1031 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1032 EXT4_I(inode
)->i_allocated_meta_blocks
= 0;
1033 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1036 /* update per-inode reservations */
1037 BUG_ON(used
> EXT4_I(inode
)->i_reserved_data_blocks
);
1038 EXT4_I(inode
)->i_reserved_data_blocks
-= used
;
1039 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1042 * If we have done all the pending block allocations and if
1043 * there aren't any writers on the inode, we can discard the
1044 * inode's preallocations.
1046 if (!total
&& (atomic_read(&inode
->i_writecount
) == 0))
1047 ext4_discard_preallocations(inode
);
1051 * The ext4_get_blocks_wrap() function try to look up the requested blocks,
1052 * and returns if the blocks are already mapped.
1054 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1055 * and store the allocated blocks in the result buffer head and mark it
1058 * If file type is extents based, it will call ext4_ext_get_blocks(),
1059 * Otherwise, call with ext4_get_blocks_handle() to handle indirect mapping
1062 * On success, it returns the number of blocks being mapped or allocate.
1063 * if create==0 and the blocks are pre-allocated and uninitialized block,
1064 * the result buffer head is unmapped. If the create ==1, it will make sure
1065 * the buffer head is mapped.
1067 * It returns 0 if plain look up failed (blocks have not been allocated), in
1068 * that casem, buffer head is unmapped
1070 * It returns the error in case of allocation failure.
1072 int ext4_get_blocks_wrap(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1073 unsigned int max_blocks
, struct buffer_head
*bh
,
1074 int create
, int extend_disksize
, int flag
)
1078 clear_buffer_mapped(bh
);
1081 * Try to see if we can get the block without requesting
1082 * for new file system block.
1084 down_read((&EXT4_I(inode
)->i_data_sem
));
1085 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1086 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1089 retval
= ext4_get_blocks_handle(handle
,
1090 inode
, block
, max_blocks
, bh
, 0, 0);
1092 up_read((&EXT4_I(inode
)->i_data_sem
));
1094 /* If it is only a block(s) look up */
1099 * Returns if the blocks have already allocated
1101 * Note that if blocks have been preallocated
1102 * ext4_ext_get_block() returns th create = 0
1103 * with buffer head unmapped.
1105 if (retval
> 0 && buffer_mapped(bh
))
1109 * New blocks allocate and/or writing to uninitialized extent
1110 * will possibly result in updating i_data, so we take
1111 * the write lock of i_data_sem, and call get_blocks()
1112 * with create == 1 flag.
1114 down_write((&EXT4_I(inode
)->i_data_sem
));
1117 * if the caller is from delayed allocation writeout path
1118 * we have already reserved fs blocks for allocation
1119 * let the underlying get_block() function know to
1120 * avoid double accounting
1123 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1125 * We need to check for EXT4 here because migrate
1126 * could have changed the inode type in between
1128 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1129 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1130 bh
, create
, extend_disksize
);
1132 retval
= ext4_get_blocks_handle(handle
, inode
, block
,
1133 max_blocks
, bh
, create
, extend_disksize
);
1135 if (retval
> 0 && buffer_new(bh
)) {
1137 * We allocated new blocks which will result in
1138 * i_data's format changing. Force the migrate
1139 * to fail by clearing migrate flags
1141 EXT4_I(inode
)->i_flags
= EXT4_I(inode
)->i_flags
&
1147 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1149 * Update reserved blocks/metadata blocks
1150 * after successful block allocation
1151 * which were deferred till now
1153 if ((retval
> 0) && buffer_delay(bh
))
1154 ext4_da_update_reserve_space(inode
, retval
);
1157 up_write((&EXT4_I(inode
)->i_data_sem
));
1161 /* Maximum number of blocks we map for direct IO at once. */
1162 #define DIO_MAX_BLOCKS 4096
1164 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1165 struct buffer_head
*bh_result
, int create
)
1167 handle_t
*handle
= ext4_journal_current_handle();
1168 int ret
= 0, started
= 0;
1169 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1172 if (create
&& !handle
) {
1173 /* Direct IO write... */
1174 if (max_blocks
> DIO_MAX_BLOCKS
)
1175 max_blocks
= DIO_MAX_BLOCKS
;
1176 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1177 handle
= ext4_journal_start(inode
, dio_credits
);
1178 if (IS_ERR(handle
)) {
1179 ret
= PTR_ERR(handle
);
1185 ret
= ext4_get_blocks_wrap(handle
, inode
, iblock
,
1186 max_blocks
, bh_result
, create
, 0, 0);
1188 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1192 ext4_journal_stop(handle
);
1198 * `handle' can be NULL if create is zero
1200 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1201 ext4_lblk_t block
, int create
, int *errp
)
1203 struct buffer_head dummy
;
1206 J_ASSERT(handle
!= NULL
|| create
== 0);
1209 dummy
.b_blocknr
= -1000;
1210 buffer_trace_init(&dummy
.b_history
);
1211 err
= ext4_get_blocks_wrap(handle
, inode
, block
, 1,
1212 &dummy
, create
, 1, 0);
1214 * ext4_get_blocks_handle() returns number of blocks
1215 * mapped. 0 in case of a HOLE.
1223 if (!err
&& buffer_mapped(&dummy
)) {
1224 struct buffer_head
*bh
;
1225 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1230 if (buffer_new(&dummy
)) {
1231 J_ASSERT(create
!= 0);
1232 J_ASSERT(handle
!= NULL
);
1235 * Now that we do not always journal data, we should
1236 * keep in mind whether this should always journal the
1237 * new buffer as metadata. For now, regular file
1238 * writes use ext4_get_block instead, so it's not a
1242 BUFFER_TRACE(bh
, "call get_create_access");
1243 fatal
= ext4_journal_get_create_access(handle
, bh
);
1244 if (!fatal
&& !buffer_uptodate(bh
)) {
1245 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1246 set_buffer_uptodate(bh
);
1249 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1250 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1254 BUFFER_TRACE(bh
, "not a new buffer");
1267 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1268 ext4_lblk_t block
, int create
, int *err
)
1270 struct buffer_head
*bh
;
1272 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1275 if (buffer_uptodate(bh
))
1277 ll_rw_block(READ_META
, 1, &bh
);
1279 if (buffer_uptodate(bh
))
1286 static int walk_page_buffers(handle_t
*handle
,
1287 struct buffer_head
*head
,
1291 int (*fn
)(handle_t
*handle
,
1292 struct buffer_head
*bh
))
1294 struct buffer_head
*bh
;
1295 unsigned block_start
, block_end
;
1296 unsigned blocksize
= head
->b_size
;
1298 struct buffer_head
*next
;
1300 for (bh
= head
, block_start
= 0;
1301 ret
== 0 && (bh
!= head
|| !block_start
);
1302 block_start
= block_end
, bh
= next
)
1304 next
= bh
->b_this_page
;
1305 block_end
= block_start
+ blocksize
;
1306 if (block_end
<= from
|| block_start
>= to
) {
1307 if (partial
&& !buffer_uptodate(bh
))
1311 err
= (*fn
)(handle
, bh
);
1319 * To preserve ordering, it is essential that the hole instantiation and
1320 * the data write be encapsulated in a single transaction. We cannot
1321 * close off a transaction and start a new one between the ext4_get_block()
1322 * and the commit_write(). So doing the jbd2_journal_start at the start of
1323 * prepare_write() is the right place.
1325 * Also, this function can nest inside ext4_writepage() ->
1326 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1327 * has generated enough buffer credits to do the whole page. So we won't
1328 * block on the journal in that case, which is good, because the caller may
1331 * By accident, ext4 can be reentered when a transaction is open via
1332 * quota file writes. If we were to commit the transaction while thus
1333 * reentered, there can be a deadlock - we would be holding a quota
1334 * lock, and the commit would never complete if another thread had a
1335 * transaction open and was blocking on the quota lock - a ranking
1338 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1339 * will _not_ run commit under these circumstances because handle->h_ref
1340 * is elevated. We'll still have enough credits for the tiny quotafile
1343 static int do_journal_get_write_access(handle_t
*handle
,
1344 struct buffer_head
*bh
)
1346 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1348 return ext4_journal_get_write_access(handle
, bh
);
1351 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1352 loff_t pos
, unsigned len
, unsigned flags
,
1353 struct page
**pagep
, void **fsdata
)
1355 struct inode
*inode
= mapping
->host
;
1356 int ret
, needed_blocks
= ext4_writepage_trans_blocks(inode
);
1363 trace_mark(ext4_write_begin
,
1364 "dev %s ino %lu pos %llu len %u flags %u",
1365 inode
->i_sb
->s_id
, inode
->i_ino
,
1366 (unsigned long long) pos
, len
, flags
);
1367 index
= pos
>> PAGE_CACHE_SHIFT
;
1368 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1372 handle
= ext4_journal_start(inode
, needed_blocks
);
1373 if (IS_ERR(handle
)) {
1374 ret
= PTR_ERR(handle
);
1378 /* We cannot recurse into the filesystem as the transaction is already
1380 flags
|= AOP_FLAG_NOFS
;
1382 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1384 ext4_journal_stop(handle
);
1390 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1393 if (!ret
&& ext4_should_journal_data(inode
)) {
1394 ret
= walk_page_buffers(handle
, page_buffers(page
),
1395 from
, to
, NULL
, do_journal_get_write_access
);
1400 ext4_journal_stop(handle
);
1401 page_cache_release(page
);
1403 * block_write_begin may have instantiated a few blocks
1404 * outside i_size. Trim these off again. Don't need
1405 * i_size_read because we hold i_mutex.
1407 if (pos
+ len
> inode
->i_size
)
1408 vmtruncate(inode
, inode
->i_size
);
1411 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1417 /* For write_end() in data=journal mode */
1418 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1420 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1422 set_buffer_uptodate(bh
);
1423 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1427 * We need to pick up the new inode size which generic_commit_write gave us
1428 * `file' can be NULL - eg, when called from page_symlink().
1430 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1431 * buffers are managed internally.
1433 static int ext4_ordered_write_end(struct file
*file
,
1434 struct address_space
*mapping
,
1435 loff_t pos
, unsigned len
, unsigned copied
,
1436 struct page
*page
, void *fsdata
)
1438 handle_t
*handle
= ext4_journal_current_handle();
1439 struct inode
*inode
= mapping
->host
;
1442 trace_mark(ext4_ordered_write_end
,
1443 "dev %s ino %lu pos %llu len %u copied %u",
1444 inode
->i_sb
->s_id
, inode
->i_ino
,
1445 (unsigned long long) pos
, len
, copied
);
1446 ret
= ext4_jbd2_file_inode(handle
, inode
);
1451 new_i_size
= pos
+ copied
;
1452 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1453 ext4_update_i_disksize(inode
, new_i_size
);
1454 /* We need to mark inode dirty even if
1455 * new_i_size is less that inode->i_size
1456 * bu greater than i_disksize.(hint delalloc)
1458 ext4_mark_inode_dirty(handle
, inode
);
1461 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
1467 ret2
= ext4_journal_stop(handle
);
1471 return ret
? ret
: copied
;
1474 static int ext4_writeback_write_end(struct file
*file
,
1475 struct address_space
*mapping
,
1476 loff_t pos
, unsigned len
, unsigned copied
,
1477 struct page
*page
, void *fsdata
)
1479 handle_t
*handle
= ext4_journal_current_handle();
1480 struct inode
*inode
= mapping
->host
;
1484 trace_mark(ext4_writeback_write_end
,
1485 "dev %s ino %lu pos %llu len %u copied %u",
1486 inode
->i_sb
->s_id
, inode
->i_ino
,
1487 (unsigned long long) pos
, len
, copied
);
1488 new_i_size
= pos
+ copied
;
1489 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1490 ext4_update_i_disksize(inode
, new_i_size
);
1491 /* We need to mark inode dirty even if
1492 * new_i_size is less that inode->i_size
1493 * bu greater than i_disksize.(hint delalloc)
1495 ext4_mark_inode_dirty(handle
, inode
);
1498 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
1504 ret2
= ext4_journal_stop(handle
);
1508 return ret
? ret
: copied
;
1511 static int ext4_journalled_write_end(struct file
*file
,
1512 struct address_space
*mapping
,
1513 loff_t pos
, unsigned len
, unsigned copied
,
1514 struct page
*page
, void *fsdata
)
1516 handle_t
*handle
= ext4_journal_current_handle();
1517 struct inode
*inode
= mapping
->host
;
1523 trace_mark(ext4_journalled_write_end
,
1524 "dev %s ino %lu pos %llu len %u copied %u",
1525 inode
->i_sb
->s_id
, inode
->i_ino
,
1526 (unsigned long long) pos
, len
, copied
);
1527 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1531 if (!PageUptodate(page
))
1533 page_zero_new_buffers(page
, from
+copied
, to
);
1536 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1537 to
, &partial
, write_end_fn
);
1539 SetPageUptodate(page
);
1540 new_i_size
= pos
+ copied
;
1541 if (new_i_size
> inode
->i_size
)
1542 i_size_write(inode
, pos
+copied
);
1543 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1544 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1545 ext4_update_i_disksize(inode
, new_i_size
);
1546 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1552 ret2
= ext4_journal_stop(handle
);
1555 page_cache_release(page
);
1557 return ret
? ret
: copied
;
1560 static int ext4_da_reserve_space(struct inode
*inode
, int nrblocks
)
1563 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1564 unsigned long md_needed
, mdblocks
, total
= 0;
1567 * recalculate the amount of metadata blocks to reserve
1568 * in order to allocate nrblocks
1569 * worse case is one extent per block
1572 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1573 total
= EXT4_I(inode
)->i_reserved_data_blocks
+ nrblocks
;
1574 mdblocks
= ext4_calc_metadata_amount(inode
, total
);
1575 BUG_ON(mdblocks
< EXT4_I(inode
)->i_reserved_meta_blocks
);
1577 md_needed
= mdblocks
- EXT4_I(inode
)->i_reserved_meta_blocks
;
1578 total
= md_needed
+ nrblocks
;
1580 if (ext4_claim_free_blocks(sbi
, total
)) {
1581 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1582 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1588 EXT4_I(inode
)->i_reserved_data_blocks
+= nrblocks
;
1589 EXT4_I(inode
)->i_reserved_meta_blocks
= mdblocks
;
1591 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1592 return 0; /* success */
1595 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1597 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1598 int total
, mdb
, mdb_free
, release
;
1601 return; /* Nothing to release, exit */
1603 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1605 if (!EXT4_I(inode
)->i_reserved_data_blocks
) {
1607 * if there is no reserved blocks, but we try to free some
1608 * then the counter is messed up somewhere.
1609 * but since this function is called from invalidate
1610 * page, it's harmless to return without any action
1612 printk(KERN_INFO
"ext4 delalloc try to release %d reserved "
1613 "blocks for inode %lu, but there is no reserved "
1614 "data blocks\n", to_free
, inode
->i_ino
);
1615 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1619 /* recalculate the number of metablocks still need to be reserved */
1620 total
= EXT4_I(inode
)->i_reserved_data_blocks
- to_free
;
1621 mdb
= ext4_calc_metadata_amount(inode
, total
);
1623 /* figure out how many metablocks to release */
1624 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1625 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1627 release
= to_free
+ mdb_free
;
1629 /* update fs dirty blocks counter for truncate case */
1630 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, release
);
1632 /* update per-inode reservations */
1633 BUG_ON(to_free
> EXT4_I(inode
)->i_reserved_data_blocks
);
1634 EXT4_I(inode
)->i_reserved_data_blocks
-= to_free
;
1636 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1637 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1638 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1641 static void ext4_da_page_release_reservation(struct page
*page
,
1642 unsigned long offset
)
1645 struct buffer_head
*head
, *bh
;
1646 unsigned int curr_off
= 0;
1648 head
= page_buffers(page
);
1651 unsigned int next_off
= curr_off
+ bh
->b_size
;
1653 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1655 clear_buffer_delay(bh
);
1657 curr_off
= next_off
;
1658 } while ((bh
= bh
->b_this_page
) != head
);
1659 ext4_da_release_space(page
->mapping
->host
, to_release
);
1663 * Delayed allocation stuff
1666 struct mpage_da_data
{
1667 struct inode
*inode
;
1668 struct buffer_head lbh
; /* extent of blocks */
1669 unsigned long first_page
, next_page
; /* extent of pages */
1670 get_block_t
*get_block
;
1671 struct writeback_control
*wbc
;
1678 * mpage_da_submit_io - walks through extent of pages and try to write
1679 * them with writepage() call back
1681 * @mpd->inode: inode
1682 * @mpd->first_page: first page of the extent
1683 * @mpd->next_page: page after the last page of the extent
1684 * @mpd->get_block: the filesystem's block mapper function
1686 * By the time mpage_da_submit_io() is called we expect all blocks
1687 * to be allocated. this may be wrong if allocation failed.
1689 * As pages are already locked by write_cache_pages(), we can't use it
1691 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1694 struct pagevec pvec
;
1695 unsigned long index
, end
;
1696 int ret
= 0, err
, nr_pages
, i
;
1697 struct inode
*inode
= mpd
->inode
;
1698 struct address_space
*mapping
= inode
->i_mapping
;
1700 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1702 * We need to start from the first_page to the next_page - 1
1703 * to make sure we also write the mapped dirty buffer_heads.
1704 * If we look at mpd->lbh.b_blocknr we would only be looking
1705 * at the currently mapped buffer_heads.
1707 index
= mpd
->first_page
;
1708 end
= mpd
->next_page
- 1;
1710 pagevec_init(&pvec
, 0);
1711 while (index
<= end
) {
1712 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1715 for (i
= 0; i
< nr_pages
; i
++) {
1716 struct page
*page
= pvec
.pages
[i
];
1718 index
= page
->index
;
1723 BUG_ON(!PageLocked(page
));
1724 BUG_ON(PageWriteback(page
));
1726 pages_skipped
= mpd
->wbc
->pages_skipped
;
1727 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
1728 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
1730 * have successfully written the page
1731 * without skipping the same
1733 mpd
->pages_written
++;
1735 * In error case, we have to continue because
1736 * remaining pages are still locked
1737 * XXX: unlock and re-dirty them?
1742 pagevec_release(&pvec
);
1748 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
1750 * @mpd->inode - inode to walk through
1751 * @exbh->b_blocknr - first block on a disk
1752 * @exbh->b_size - amount of space in bytes
1753 * @logical - first logical block to start assignment with
1755 * the function goes through all passed space and put actual disk
1756 * block numbers into buffer heads, dropping BH_Delay
1758 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
1759 struct buffer_head
*exbh
)
1761 struct inode
*inode
= mpd
->inode
;
1762 struct address_space
*mapping
= inode
->i_mapping
;
1763 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
1764 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
1765 struct buffer_head
*head
, *bh
;
1767 struct pagevec pvec
;
1770 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1771 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1772 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1774 pagevec_init(&pvec
, 0);
1776 while (index
<= end
) {
1777 /* XXX: optimize tail */
1778 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1781 for (i
= 0; i
< nr_pages
; i
++) {
1782 struct page
*page
= pvec
.pages
[i
];
1784 index
= page
->index
;
1789 BUG_ON(!PageLocked(page
));
1790 BUG_ON(PageWriteback(page
));
1791 BUG_ON(!page_has_buffers(page
));
1793 bh
= page_buffers(page
);
1796 /* skip blocks out of the range */
1798 if (cur_logical
>= logical
)
1801 } while ((bh
= bh
->b_this_page
) != head
);
1804 if (cur_logical
>= logical
+ blocks
)
1806 if (buffer_delay(bh
)) {
1807 bh
->b_blocknr
= pblock
;
1808 clear_buffer_delay(bh
);
1809 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
1810 } else if (buffer_unwritten(bh
)) {
1811 bh
->b_blocknr
= pblock
;
1812 clear_buffer_unwritten(bh
);
1813 set_buffer_mapped(bh
);
1815 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
1816 } else if (buffer_mapped(bh
))
1817 BUG_ON(bh
->b_blocknr
!= pblock
);
1821 } while ((bh
= bh
->b_this_page
) != head
);
1823 pagevec_release(&pvec
);
1829 * __unmap_underlying_blocks - just a helper function to unmap
1830 * set of blocks described by @bh
1832 static inline void __unmap_underlying_blocks(struct inode
*inode
,
1833 struct buffer_head
*bh
)
1835 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
1838 blocks
= bh
->b_size
>> inode
->i_blkbits
;
1839 for (i
= 0; i
< blocks
; i
++)
1840 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
1843 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
1844 sector_t logical
, long blk_cnt
)
1848 struct pagevec pvec
;
1849 struct inode
*inode
= mpd
->inode
;
1850 struct address_space
*mapping
= inode
->i_mapping
;
1852 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1853 end
= (logical
+ blk_cnt
- 1) >>
1854 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1855 while (index
<= end
) {
1856 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1859 for (i
= 0; i
< nr_pages
; i
++) {
1860 struct page
*page
= pvec
.pages
[i
];
1861 index
= page
->index
;
1866 BUG_ON(!PageLocked(page
));
1867 BUG_ON(PageWriteback(page
));
1868 block_invalidatepage(page
, 0);
1869 ClearPageUptodate(page
);
1876 static void ext4_print_free_blocks(struct inode
*inode
)
1878 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1879 printk(KERN_EMERG
"Total free blocks count %lld\n",
1880 ext4_count_free_blocks(inode
->i_sb
));
1881 printk(KERN_EMERG
"Free/Dirty block details\n");
1882 printk(KERN_EMERG
"free_blocks=%lld\n",
1883 (long long)percpu_counter_sum(&sbi
->s_freeblocks_counter
));
1884 printk(KERN_EMERG
"dirty_blocks=%lld\n",
1885 (long long)percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
1886 printk(KERN_EMERG
"Block reservation details\n");
1887 printk(KERN_EMERG
"i_reserved_data_blocks=%u\n",
1888 EXT4_I(inode
)->i_reserved_data_blocks
);
1889 printk(KERN_EMERG
"i_reserved_meta_blocks=%u\n",
1890 EXT4_I(inode
)->i_reserved_meta_blocks
);
1895 * mpage_da_map_blocks - go through given space
1897 * @mpd->lbh - bh describing space
1898 * @mpd->get_block - the filesystem's block mapper function
1900 * The function skips space we know is already mapped to disk blocks.
1903 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
1906 struct buffer_head
new;
1907 struct buffer_head
*lbh
= &mpd
->lbh
;
1911 * We consider only non-mapped and non-allocated blocks
1913 if (buffer_mapped(lbh
) && !buffer_delay(lbh
))
1915 new.b_state
= lbh
->b_state
;
1917 new.b_size
= lbh
->b_size
;
1918 next
= lbh
->b_blocknr
;
1920 * If we didn't accumulate anything
1921 * to write simply return
1925 err
= mpd
->get_block(mpd
->inode
, next
, &new, 1);
1928 /* If get block returns with error
1929 * we simply return. Later writepage
1930 * will redirty the page and writepages
1931 * will find the dirty page again
1936 if (err
== -ENOSPC
&&
1937 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
1943 * get block failure will cause us
1944 * to loop in writepages. Because
1945 * a_ops->writepage won't be able to
1946 * make progress. The page will be redirtied
1947 * by writepage and writepages will again
1948 * try to write the same.
1950 printk(KERN_EMERG
"%s block allocation failed for inode %lu "
1951 "at logical offset %llu with max blocks "
1952 "%zd with error %d\n",
1953 __func__
, mpd
->inode
->i_ino
,
1954 (unsigned long long)next
,
1955 lbh
->b_size
>> mpd
->inode
->i_blkbits
, err
);
1956 printk(KERN_EMERG
"This should not happen.!! "
1957 "Data will be lost\n");
1958 if (err
== -ENOSPC
) {
1959 ext4_print_free_blocks(mpd
->inode
);
1961 /* invlaidate all the pages */
1962 ext4_da_block_invalidatepages(mpd
, next
,
1963 lbh
->b_size
>> mpd
->inode
->i_blkbits
);
1966 BUG_ON(new.b_size
== 0);
1968 if (buffer_new(&new))
1969 __unmap_underlying_blocks(mpd
->inode
, &new);
1972 * If blocks are delayed marked, we need to
1973 * put actual blocknr and drop delayed bit
1975 if (buffer_delay(lbh
) || buffer_unwritten(lbh
))
1976 mpage_put_bnr_to_bhs(mpd
, next
, &new);
1981 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1982 (1 << BH_Delay) | (1 << BH_Unwritten))
1985 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1987 * @mpd->lbh - extent of blocks
1988 * @logical - logical number of the block in the file
1989 * @bh - bh of the block (used to access block's state)
1991 * the function is used to collect contig. blocks in same state
1993 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
1994 sector_t logical
, struct buffer_head
*bh
)
1997 size_t b_size
= bh
->b_size
;
1998 struct buffer_head
*lbh
= &mpd
->lbh
;
1999 int nrblocks
= lbh
->b_size
>> mpd
->inode
->i_blkbits
;
2001 /* check if thereserved journal credits might overflow */
2002 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
2003 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2005 * With non-extent format we are limited by the journal
2006 * credit available. Total credit needed to insert
2007 * nrblocks contiguous blocks is dependent on the
2008 * nrblocks. So limit nrblocks.
2011 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2012 EXT4_MAX_TRANS_DATA
) {
2014 * Adding the new buffer_head would make it cross the
2015 * allowed limit for which we have journal credit
2016 * reserved. So limit the new bh->b_size
2018 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2019 mpd
->inode
->i_blkbits
;
2020 /* we will do mpage_da_submit_io in the next loop */
2024 * First block in the extent
2026 if (lbh
->b_size
== 0) {
2027 lbh
->b_blocknr
= logical
;
2028 lbh
->b_size
= b_size
;
2029 lbh
->b_state
= bh
->b_state
& BH_FLAGS
;
2033 next
= lbh
->b_blocknr
+ nrblocks
;
2035 * Can we merge the block to our big extent?
2037 if (logical
== next
&& (bh
->b_state
& BH_FLAGS
) == lbh
->b_state
) {
2038 lbh
->b_size
+= b_size
;
2044 * We couldn't merge the block to our extent, so we
2045 * need to flush current extent and start new one
2047 if (mpage_da_map_blocks(mpd
) == 0)
2048 mpage_da_submit_io(mpd
);
2054 * __mpage_da_writepage - finds extent of pages and blocks
2056 * @page: page to consider
2057 * @wbc: not used, we just follow rules
2060 * The function finds extents of pages and scan them for all blocks.
2062 static int __mpage_da_writepage(struct page
*page
,
2063 struct writeback_control
*wbc
, void *data
)
2065 struct mpage_da_data
*mpd
= data
;
2066 struct inode
*inode
= mpd
->inode
;
2067 struct buffer_head
*bh
, *head
, fake
;
2072 * Rest of the page in the page_vec
2073 * redirty then and skip then. We will
2074 * try to to write them again after
2075 * starting a new transaction
2077 redirty_page_for_writepage(wbc
, page
);
2079 return MPAGE_DA_EXTENT_TAIL
;
2082 * Can we merge this page to current extent?
2084 if (mpd
->next_page
!= page
->index
) {
2086 * Nope, we can't. So, we map non-allocated blocks
2087 * and start IO on them using writepage()
2089 if (mpd
->next_page
!= mpd
->first_page
) {
2090 if (mpage_da_map_blocks(mpd
) == 0)
2091 mpage_da_submit_io(mpd
);
2093 * skip rest of the page in the page_vec
2096 redirty_page_for_writepage(wbc
, page
);
2098 return MPAGE_DA_EXTENT_TAIL
;
2102 * Start next extent of pages ...
2104 mpd
->first_page
= page
->index
;
2109 mpd
->lbh
.b_size
= 0;
2110 mpd
->lbh
.b_state
= 0;
2111 mpd
->lbh
.b_blocknr
= 0;
2114 mpd
->next_page
= page
->index
+ 1;
2115 logical
= (sector_t
) page
->index
<<
2116 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2118 if (!page_has_buffers(page
)) {
2120 * There is no attached buffer heads yet (mmap?)
2121 * we treat the page asfull of dirty blocks
2124 bh
->b_size
= PAGE_CACHE_SIZE
;
2126 set_buffer_dirty(bh
);
2127 set_buffer_uptodate(bh
);
2128 mpage_add_bh_to_extent(mpd
, logical
, bh
);
2130 return MPAGE_DA_EXTENT_TAIL
;
2133 * Page with regular buffer heads, just add all dirty ones
2135 head
= page_buffers(page
);
2138 BUG_ON(buffer_locked(bh
));
2140 * We need to try to allocate
2141 * unmapped blocks in the same page.
2142 * Otherwise we won't make progress
2143 * with the page in ext4_da_writepage
2145 if (buffer_dirty(bh
) &&
2146 (!buffer_mapped(bh
) || buffer_delay(bh
))) {
2147 mpage_add_bh_to_extent(mpd
, logical
, bh
);
2149 return MPAGE_DA_EXTENT_TAIL
;
2150 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2152 * mapped dirty buffer. We need to update
2153 * the b_state because we look at
2154 * b_state in mpage_da_map_blocks. We don't
2155 * update b_size because if we find an
2156 * unmapped buffer_head later we need to
2157 * use the b_state flag of that buffer_head.
2159 if (mpd
->lbh
.b_size
== 0)
2161 bh
->b_state
& BH_FLAGS
;
2164 } while ((bh
= bh
->b_this_page
) != head
);
2171 * mpage_da_writepages - walk the list of dirty pages of the given
2172 * address space, allocates non-allocated blocks, maps newly-allocated
2173 * blocks to existing bhs and issue IO them
2175 * @mapping: address space structure to write
2176 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2177 * @get_block: the filesystem's block mapper function.
2179 * This is a library function, which implements the writepages()
2180 * address_space_operation.
2182 static int mpage_da_writepages(struct address_space
*mapping
,
2183 struct writeback_control
*wbc
,
2184 struct mpage_da_data
*mpd
)
2188 if (!mpd
->get_block
)
2189 return generic_writepages(mapping
, wbc
);
2191 mpd
->lbh
.b_size
= 0;
2192 mpd
->lbh
.b_state
= 0;
2193 mpd
->lbh
.b_blocknr
= 0;
2194 mpd
->first_page
= 0;
2197 mpd
->pages_written
= 0;
2200 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
, mpd
);
2202 * Handle last extent of pages
2204 if (!mpd
->io_done
&& mpd
->next_page
!= mpd
->first_page
) {
2205 if (mpage_da_map_blocks(mpd
) == 0)
2206 mpage_da_submit_io(mpd
);
2209 ret
= MPAGE_DA_EXTENT_TAIL
;
2211 wbc
->nr_to_write
-= mpd
->pages_written
;
2216 * this is a special callback for ->write_begin() only
2217 * it's intention is to return mapped block or reserve space
2219 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2220 struct buffer_head
*bh_result
, int create
)
2224 BUG_ON(create
== 0);
2225 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2228 * first, we need to know whether the block is allocated already
2229 * preallocated blocks are unmapped but should treated
2230 * the same as allocated blocks.
2232 ret
= ext4_get_blocks_wrap(NULL
, inode
, iblock
, 1, bh_result
, 0, 0, 0);
2233 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2234 /* the block isn't (pre)allocated yet, let's reserve space */
2236 * XXX: __block_prepare_write() unmaps passed block,
2239 ret
= ext4_da_reserve_space(inode
, 1);
2241 /* not enough space to reserve */
2244 map_bh(bh_result
, inode
->i_sb
, 0);
2245 set_buffer_new(bh_result
);
2246 set_buffer_delay(bh_result
);
2247 } else if (ret
> 0) {
2248 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2254 #define EXT4_DELALLOC_RSVED 1
2255 static int ext4_da_get_block_write(struct inode
*inode
, sector_t iblock
,
2256 struct buffer_head
*bh_result
, int create
)
2259 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2260 loff_t disksize
= EXT4_I(inode
)->i_disksize
;
2261 handle_t
*handle
= NULL
;
2263 handle
= ext4_journal_current_handle();
2265 ret
= ext4_get_blocks_wrap(handle
, inode
, iblock
, max_blocks
,
2266 bh_result
, create
, 0, EXT4_DELALLOC_RSVED
);
2269 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2271 if (ext4_should_order_data(inode
)) {
2273 retval
= ext4_jbd2_file_inode(handle
, inode
);
2276 * Failed to add inode for ordered
2277 * mode. Don't update file size
2283 * Update on-disk size along with block allocation
2284 * we don't use 'extend_disksize' as size may change
2285 * within already allocated block -bzzz
2287 disksize
= ((loff_t
) iblock
+ ret
) << inode
->i_blkbits
;
2288 if (disksize
> i_size_read(inode
))
2289 disksize
= i_size_read(inode
);
2290 if (disksize
> EXT4_I(inode
)->i_disksize
) {
2291 ext4_update_i_disksize(inode
, disksize
);
2292 ret
= ext4_mark_inode_dirty(handle
, inode
);
2300 static int ext4_bh_unmapped_or_delay(handle_t
*handle
, struct buffer_head
*bh
)
2303 * unmapped buffer is possible for holes.
2304 * delay buffer is possible with delayed allocation
2306 return ((!buffer_mapped(bh
) || buffer_delay(bh
)) && buffer_dirty(bh
));
2309 static int ext4_normal_get_block_write(struct inode
*inode
, sector_t iblock
,
2310 struct buffer_head
*bh_result
, int create
)
2313 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2316 * we don't want to do block allocation in writepage
2317 * so call get_block_wrap with create = 0
2319 ret
= ext4_get_blocks_wrap(NULL
, inode
, iblock
, max_blocks
,
2320 bh_result
, 0, 0, 0);
2322 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2329 * get called vi ext4_da_writepages after taking page lock (have journal handle)
2330 * get called via journal_submit_inode_data_buffers (no journal handle)
2331 * get called via shrink_page_list via pdflush (no journal handle)
2332 * or grab_page_cache when doing write_begin (have journal handle)
2334 static int ext4_da_writepage(struct page
*page
,
2335 struct writeback_control
*wbc
)
2340 struct buffer_head
*page_bufs
;
2341 struct inode
*inode
= page
->mapping
->host
;
2343 trace_mark(ext4_da_writepage
,
2344 "dev %s ino %lu page_index %lu",
2345 inode
->i_sb
->s_id
, inode
->i_ino
, page
->index
);
2346 size
= i_size_read(inode
);
2347 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2348 len
= size
& ~PAGE_CACHE_MASK
;
2350 len
= PAGE_CACHE_SIZE
;
2352 if (page_has_buffers(page
)) {
2353 page_bufs
= page_buffers(page
);
2354 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2355 ext4_bh_unmapped_or_delay
)) {
2357 * We don't want to do block allocation
2358 * So redirty the page and return
2359 * We may reach here when we do a journal commit
2360 * via journal_submit_inode_data_buffers.
2361 * If we don't have mapping block we just ignore
2362 * them. We can also reach here via shrink_page_list
2364 redirty_page_for_writepage(wbc
, page
);
2370 * The test for page_has_buffers() is subtle:
2371 * We know the page is dirty but it lost buffers. That means
2372 * that at some moment in time after write_begin()/write_end()
2373 * has been called all buffers have been clean and thus they
2374 * must have been written at least once. So they are all
2375 * mapped and we can happily proceed with mapping them
2376 * and writing the page.
2378 * Try to initialize the buffer_heads and check whether
2379 * all are mapped and non delay. We don't want to
2380 * do block allocation here.
2382 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
2383 ext4_normal_get_block_write
);
2385 page_bufs
= page_buffers(page
);
2386 /* check whether all are mapped and non delay */
2387 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2388 ext4_bh_unmapped_or_delay
)) {
2389 redirty_page_for_writepage(wbc
, page
);
2395 * We can't do block allocation here
2396 * so just redity the page and unlock
2399 redirty_page_for_writepage(wbc
, page
);
2403 /* now mark the buffer_heads as dirty and uptodate */
2404 block_commit_write(page
, 0, PAGE_CACHE_SIZE
);
2407 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2408 ret
= nobh_writepage(page
, ext4_normal_get_block_write
, wbc
);
2410 ret
= block_write_full_page(page
,
2411 ext4_normal_get_block_write
,
2418 * This is called via ext4_da_writepages() to
2419 * calulate the total number of credits to reserve to fit
2420 * a single extent allocation into a single transaction,
2421 * ext4_da_writpeages() will loop calling this before
2422 * the block allocation.
2425 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2427 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2430 * With non-extent format the journal credit needed to
2431 * insert nrblocks contiguous block is dependent on
2432 * number of contiguous block. So we will limit
2433 * number of contiguous block to a sane value
2435 if (!(inode
->i_flags
& EXT4_EXTENTS_FL
) &&
2436 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2437 max_blocks
= EXT4_MAX_TRANS_DATA
;
2439 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2442 static int ext4_da_writepages(struct address_space
*mapping
,
2443 struct writeback_control
*wbc
)
2446 int range_whole
= 0;
2447 handle_t
*handle
= NULL
;
2448 struct mpage_da_data mpd
;
2449 struct inode
*inode
= mapping
->host
;
2450 int no_nrwrite_index_update
;
2451 int pages_written
= 0;
2453 int range_cyclic
, cycled
= 1, io_done
= 0;
2454 int needed_blocks
, ret
= 0, nr_to_writebump
= 0;
2455 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2457 trace_mark(ext4_da_writepages
,
2458 "dev %s ino %lu nr_t_write %ld "
2459 "pages_skipped %ld range_start %llu "
2460 "range_end %llu nonblocking %d "
2461 "for_kupdate %d for_reclaim %d "
2462 "for_writepages %d range_cyclic %d",
2463 inode
->i_sb
->s_id
, inode
->i_ino
,
2464 wbc
->nr_to_write
, wbc
->pages_skipped
,
2465 (unsigned long long) wbc
->range_start
,
2466 (unsigned long long) wbc
->range_end
,
2467 wbc
->nonblocking
, wbc
->for_kupdate
,
2468 wbc
->for_reclaim
, wbc
->for_writepages
,
2472 * No pages to write? This is mainly a kludge to avoid starting
2473 * a transaction for special inodes like journal inode on last iput()
2474 * because that could violate lock ordering on umount
2476 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2480 * If the filesystem has aborted, it is read-only, so return
2481 * right away instead of dumping stack traces later on that
2482 * will obscure the real source of the problem. We test
2483 * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because
2484 * the latter could be true if the filesystem is mounted
2485 * read-only, and in that case, ext4_da_writepages should
2486 * *never* be called, so if that ever happens, we would want
2489 if (unlikely(sbi
->s_mount_opt
& EXT4_MOUNT_ABORT
))
2493 * Make sure nr_to_write is >= sbi->s_mb_stream_request
2494 * This make sure small files blocks are allocated in
2495 * single attempt. This ensure that small files
2496 * get less fragmented.
2498 if (wbc
->nr_to_write
< sbi
->s_mb_stream_request
) {
2499 nr_to_writebump
= sbi
->s_mb_stream_request
- wbc
->nr_to_write
;
2500 wbc
->nr_to_write
= sbi
->s_mb_stream_request
;
2502 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2505 range_cyclic
= wbc
->range_cyclic
;
2506 if (wbc
->range_cyclic
) {
2507 index
= mapping
->writeback_index
;
2510 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2511 wbc
->range_end
= LLONG_MAX
;
2512 wbc
->range_cyclic
= 0;
2514 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2517 mpd
.inode
= mapping
->host
;
2520 * we don't want write_cache_pages to update
2521 * nr_to_write and writeback_index
2523 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2524 wbc
->no_nrwrite_index_update
= 1;
2525 pages_skipped
= wbc
->pages_skipped
;
2528 while (!ret
&& wbc
->nr_to_write
> 0) {
2531 * we insert one extent at a time. So we need
2532 * credit needed for single extent allocation.
2533 * journalled mode is currently not supported
2536 BUG_ON(ext4_should_journal_data(inode
));
2537 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2539 /* start a new transaction*/
2540 handle
= ext4_journal_start(inode
, needed_blocks
);
2541 if (IS_ERR(handle
)) {
2542 ret
= PTR_ERR(handle
);
2543 printk(KERN_CRIT
"%s: jbd2_start: "
2544 "%ld pages, ino %lu; err %d\n", __func__
,
2545 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2547 goto out_writepages
;
2549 mpd
.get_block
= ext4_da_get_block_write
;
2550 ret
= mpage_da_writepages(mapping
, wbc
, &mpd
);
2552 ext4_journal_stop(handle
);
2554 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2555 /* commit the transaction which would
2556 * free blocks released in the transaction
2559 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2560 wbc
->pages_skipped
= pages_skipped
;
2562 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2564 * got one extent now try with
2567 pages_written
+= mpd
.pages_written
;
2568 wbc
->pages_skipped
= pages_skipped
;
2571 } else if (wbc
->nr_to_write
)
2573 * There is no more writeout needed
2574 * or we requested for a noblocking writeout
2575 * and we found the device congested
2579 if (!io_done
&& !cycled
) {
2582 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2583 wbc
->range_end
= mapping
->writeback_index
- 1;
2586 if (pages_skipped
!= wbc
->pages_skipped
)
2587 printk(KERN_EMERG
"This should not happen leaving %s "
2588 "with nr_to_write = %ld ret = %d\n",
2589 __func__
, wbc
->nr_to_write
, ret
);
2592 index
+= pages_written
;
2593 wbc
->range_cyclic
= range_cyclic
;
2594 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2596 * set the writeback_index so that range_cyclic
2597 * mode will write it back later
2599 mapping
->writeback_index
= index
;
2602 if (!no_nrwrite_index_update
)
2603 wbc
->no_nrwrite_index_update
= 0;
2604 wbc
->nr_to_write
-= nr_to_writebump
;
2605 trace_mark(ext4_da_writepage_result
,
2606 "dev %s ino %lu ret %d pages_written %d "
2607 "pages_skipped %ld congestion %d "
2608 "more_io %d no_nrwrite_index_update %d",
2609 inode
->i_sb
->s_id
, inode
->i_ino
, ret
,
2610 pages_written
, wbc
->pages_skipped
,
2611 wbc
->encountered_congestion
, wbc
->more_io
,
2612 wbc
->no_nrwrite_index_update
);
2616 #define FALL_BACK_TO_NONDELALLOC 1
2617 static int ext4_nonda_switch(struct super_block
*sb
)
2619 s64 free_blocks
, dirty_blocks
;
2620 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2623 * switch to non delalloc mode if we are running low
2624 * on free block. The free block accounting via percpu
2625 * counters can get slightly wrong with percpu_counter_batch getting
2626 * accumulated on each CPU without updating global counters
2627 * Delalloc need an accurate free block accounting. So switch
2628 * to non delalloc when we are near to error range.
2630 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
2631 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
2632 if (2 * free_blocks
< 3 * dirty_blocks
||
2633 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
2635 * free block count is less that 150% of dirty blocks
2636 * or free blocks is less that watermark
2643 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
2644 loff_t pos
, unsigned len
, unsigned flags
,
2645 struct page
**pagep
, void **fsdata
)
2647 int ret
, retries
= 0;
2651 struct inode
*inode
= mapping
->host
;
2654 index
= pos
>> PAGE_CACHE_SHIFT
;
2655 from
= pos
& (PAGE_CACHE_SIZE
- 1);
2658 if (ext4_nonda_switch(inode
->i_sb
)) {
2659 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
2660 return ext4_write_begin(file
, mapping
, pos
,
2661 len
, flags
, pagep
, fsdata
);
2663 *fsdata
= (void *)0;
2665 trace_mark(ext4_da_write_begin
,
2666 "dev %s ino %lu pos %llu len %u flags %u",
2667 inode
->i_sb
->s_id
, inode
->i_ino
,
2668 (unsigned long long) pos
, len
, flags
);
2671 * With delayed allocation, we don't log the i_disksize update
2672 * if there is delayed block allocation. But we still need
2673 * to journalling the i_disksize update if writes to the end
2674 * of file which has an already mapped buffer.
2676 handle
= ext4_journal_start(inode
, 1);
2677 if (IS_ERR(handle
)) {
2678 ret
= PTR_ERR(handle
);
2681 /* We cannot recurse into the filesystem as the transaction is already
2683 flags
|= AOP_FLAG_NOFS
;
2685 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
2687 ext4_journal_stop(handle
);
2693 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
2694 ext4_da_get_block_prep
);
2697 ext4_journal_stop(handle
);
2698 page_cache_release(page
);
2700 * block_write_begin may have instantiated a few blocks
2701 * outside i_size. Trim these off again. Don't need
2702 * i_size_read because we hold i_mutex.
2704 if (pos
+ len
> inode
->i_size
)
2705 vmtruncate(inode
, inode
->i_size
);
2708 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
2715 * Check if we should update i_disksize
2716 * when write to the end of file but not require block allocation
2718 static int ext4_da_should_update_i_disksize(struct page
*page
,
2719 unsigned long offset
)
2721 struct buffer_head
*bh
;
2722 struct inode
*inode
= page
->mapping
->host
;
2726 bh
= page_buffers(page
);
2727 idx
= offset
>> inode
->i_blkbits
;
2729 for (i
= 0; i
< idx
; i
++)
2730 bh
= bh
->b_this_page
;
2732 if (!buffer_mapped(bh
) || (buffer_delay(bh
)))
2737 static int ext4_da_write_end(struct file
*file
,
2738 struct address_space
*mapping
,
2739 loff_t pos
, unsigned len
, unsigned copied
,
2740 struct page
*page
, void *fsdata
)
2742 struct inode
*inode
= mapping
->host
;
2744 handle_t
*handle
= ext4_journal_current_handle();
2746 unsigned long start
, end
;
2747 int write_mode
= (int)(unsigned long)fsdata
;
2749 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
2750 if (ext4_should_order_data(inode
)) {
2751 return ext4_ordered_write_end(file
, mapping
, pos
,
2752 len
, copied
, page
, fsdata
);
2753 } else if (ext4_should_writeback_data(inode
)) {
2754 return ext4_writeback_write_end(file
, mapping
, pos
,
2755 len
, copied
, page
, fsdata
);
2761 trace_mark(ext4_da_write_end
,
2762 "dev %s ino %lu pos %llu len %u copied %u",
2763 inode
->i_sb
->s_id
, inode
->i_ino
,
2764 (unsigned long long) pos
, len
, copied
);
2765 start
= pos
& (PAGE_CACHE_SIZE
- 1);
2766 end
= start
+ copied
- 1;
2769 * generic_write_end() will run mark_inode_dirty() if i_size
2770 * changes. So let's piggyback the i_disksize mark_inode_dirty
2774 new_i_size
= pos
+ copied
;
2775 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2776 if (ext4_da_should_update_i_disksize(page
, end
)) {
2777 down_write(&EXT4_I(inode
)->i_data_sem
);
2778 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2780 * Updating i_disksize when extending file
2781 * without needing block allocation
2783 if (ext4_should_order_data(inode
))
2784 ret
= ext4_jbd2_file_inode(handle
,
2787 EXT4_I(inode
)->i_disksize
= new_i_size
;
2789 up_write(&EXT4_I(inode
)->i_data_sem
);
2790 /* We need to mark inode dirty even if
2791 * new_i_size is less that inode->i_size
2792 * bu greater than i_disksize.(hint delalloc)
2794 ext4_mark_inode_dirty(handle
, inode
);
2797 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
2802 ret2
= ext4_journal_stop(handle
);
2806 return ret
? ret
: copied
;
2809 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
2812 * Drop reserved blocks
2814 BUG_ON(!PageLocked(page
));
2815 if (!page_has_buffers(page
))
2818 ext4_da_page_release_reservation(page
, offset
);
2821 ext4_invalidatepage(page
, offset
);
2827 * Force all delayed allocation blocks to be allocated for a given inode.
2829 int ext4_alloc_da_blocks(struct inode
*inode
)
2831 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
2832 !EXT4_I(inode
)->i_reserved_meta_blocks
)
2836 * We do something simple for now. The filemap_flush() will
2837 * also start triggering a write of the data blocks, which is
2838 * not strictly speaking necessary (and for users of
2839 * laptop_mode, not even desirable). However, to do otherwise
2840 * would require replicating code paths in:
2842 * ext4_da_writepages() ->
2843 * write_cache_pages() ---> (via passed in callback function)
2844 * __mpage_da_writepage() -->
2845 * mpage_add_bh_to_extent()
2846 * mpage_da_map_blocks()
2848 * The problem is that write_cache_pages(), located in
2849 * mm/page-writeback.c, marks pages clean in preparation for
2850 * doing I/O, which is not desirable if we're not planning on
2853 * We could call write_cache_pages(), and then redirty all of
2854 * the pages by calling redirty_page_for_writeback() but that
2855 * would be ugly in the extreme. So instead we would need to
2856 * replicate parts of the code in the above functions,
2857 * simplifying them becuase we wouldn't actually intend to
2858 * write out the pages, but rather only collect contiguous
2859 * logical block extents, call the multi-block allocator, and
2860 * then update the buffer heads with the block allocations.
2862 * For now, though, we'll cheat by calling filemap_flush(),
2863 * which will map the blocks, and start the I/O, but not
2864 * actually wait for the I/O to complete.
2866 return filemap_flush(inode
->i_mapping
);
2870 * bmap() is special. It gets used by applications such as lilo and by
2871 * the swapper to find the on-disk block of a specific piece of data.
2873 * Naturally, this is dangerous if the block concerned is still in the
2874 * journal. If somebody makes a swapfile on an ext4 data-journaling
2875 * filesystem and enables swap, then they may get a nasty shock when the
2876 * data getting swapped to that swapfile suddenly gets overwritten by
2877 * the original zero's written out previously to the journal and
2878 * awaiting writeback in the kernel's buffer cache.
2880 * So, if we see any bmap calls here on a modified, data-journaled file,
2881 * take extra steps to flush any blocks which might be in the cache.
2883 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
2885 struct inode
*inode
= mapping
->host
;
2889 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
2890 test_opt(inode
->i_sb
, DELALLOC
)) {
2892 * With delalloc we want to sync the file
2893 * so that we can make sure we allocate
2896 filemap_write_and_wait(mapping
);
2899 if (EXT4_JOURNAL(inode
) && EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
2901 * This is a REALLY heavyweight approach, but the use of
2902 * bmap on dirty files is expected to be extremely rare:
2903 * only if we run lilo or swapon on a freshly made file
2904 * do we expect this to happen.
2906 * (bmap requires CAP_SYS_RAWIO so this does not
2907 * represent an unprivileged user DOS attack --- we'd be
2908 * in trouble if mortal users could trigger this path at
2911 * NB. EXT4_STATE_JDATA is not set on files other than
2912 * regular files. If somebody wants to bmap a directory
2913 * or symlink and gets confused because the buffer
2914 * hasn't yet been flushed to disk, they deserve
2915 * everything they get.
2918 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
2919 journal
= EXT4_JOURNAL(inode
);
2920 jbd2_journal_lock_updates(journal
);
2921 err
= jbd2_journal_flush(journal
);
2922 jbd2_journal_unlock_updates(journal
);
2928 return generic_block_bmap(mapping
, block
, ext4_get_block
);
2931 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2937 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2944 * Note that we don't need to start a transaction unless we're journaling data
2945 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2946 * need to file the inode to the transaction's list in ordered mode because if
2947 * we are writing back data added by write(), the inode is already there and if
2948 * we are writing back data modified via mmap(), noone guarantees in which
2949 * transaction the data will hit the disk. In case we are journaling data, we
2950 * cannot start transaction directly because transaction start ranks above page
2951 * lock so we have to do some magic.
2953 * In all journaling modes block_write_full_page() will start the I/O.
2957 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2962 * ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ...
2964 * Same applies to ext4_get_block(). We will deadlock on various things like
2965 * lock_journal and i_data_sem
2967 * Setting PF_MEMALLOC here doesn't work - too many internal memory
2970 * 16May01: If we're reentered then journal_current_handle() will be
2971 * non-zero. We simply *return*.
2973 * 1 July 2001: @@@ FIXME:
2974 * In journalled data mode, a data buffer may be metadata against the
2975 * current transaction. But the same file is part of a shared mapping
2976 * and someone does a writepage() on it.
2978 * We will move the buffer onto the async_data list, but *after* it has
2979 * been dirtied. So there's a small window where we have dirty data on
2982 * Note that this only applies to the last partial page in the file. The
2983 * bit which block_write_full_page() uses prepare/commit for. (That's
2984 * broken code anyway: it's wrong for msync()).
2986 * It's a rare case: affects the final partial page, for journalled data
2987 * where the file is subject to bith write() and writepage() in the same
2988 * transction. To fix it we'll need a custom block_write_full_page().
2989 * We'll probably need that anyway for journalling writepage() output.
2991 * We don't honour synchronous mounts for writepage(). That would be
2992 * disastrous. Any write() or metadata operation will sync the fs for
2996 static int __ext4_normal_writepage(struct page
*page
,
2997 struct writeback_control
*wbc
)
2999 struct inode
*inode
= page
->mapping
->host
;
3001 if (test_opt(inode
->i_sb
, NOBH
))
3002 return nobh_writepage(page
,
3003 ext4_normal_get_block_write
, wbc
);
3005 return block_write_full_page(page
,
3006 ext4_normal_get_block_write
,
3010 static int ext4_normal_writepage(struct page
*page
,
3011 struct writeback_control
*wbc
)
3013 struct inode
*inode
= page
->mapping
->host
;
3014 loff_t size
= i_size_read(inode
);
3017 trace_mark(ext4_normal_writepage
,
3018 "dev %s ino %lu page_index %lu",
3019 inode
->i_sb
->s_id
, inode
->i_ino
, page
->index
);
3020 J_ASSERT(PageLocked(page
));
3021 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
3022 len
= size
& ~PAGE_CACHE_MASK
;
3024 len
= PAGE_CACHE_SIZE
;
3026 if (page_has_buffers(page
)) {
3027 /* if page has buffers it should all be mapped
3028 * and allocated. If there are not buffers attached
3029 * to the page we know the page is dirty but it lost
3030 * buffers. That means that at some moment in time
3031 * after write_begin() / write_end() has been called
3032 * all buffers have been clean and thus they must have been
3033 * written at least once. So they are all mapped and we can
3034 * happily proceed with mapping them and writing the page.
3036 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
3037 ext4_bh_unmapped_or_delay
));
3040 if (!ext4_journal_current_handle())
3041 return __ext4_normal_writepage(page
, wbc
);
3043 redirty_page_for_writepage(wbc
, page
);
3048 static int __ext4_journalled_writepage(struct page
*page
,
3049 struct writeback_control
*wbc
)
3051 struct address_space
*mapping
= page
->mapping
;
3052 struct inode
*inode
= mapping
->host
;
3053 struct buffer_head
*page_bufs
;
3054 handle_t
*handle
= NULL
;
3058 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
3059 ext4_normal_get_block_write
);
3063 page_bufs
= page_buffers(page
);
3064 walk_page_buffers(handle
, page_bufs
, 0, PAGE_CACHE_SIZE
, NULL
,
3066 /* As soon as we unlock the page, it can go away, but we have
3067 * references to buffers so we are safe */
3070 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
3071 if (IS_ERR(handle
)) {
3072 ret
= PTR_ERR(handle
);
3076 ret
= walk_page_buffers(handle
, page_bufs
, 0,
3077 PAGE_CACHE_SIZE
, NULL
, do_journal_get_write_access
);
3079 err
= walk_page_buffers(handle
, page_bufs
, 0,
3080 PAGE_CACHE_SIZE
, NULL
, write_end_fn
);
3083 err
= ext4_journal_stop(handle
);
3087 walk_page_buffers(handle
, page_bufs
, 0,
3088 PAGE_CACHE_SIZE
, NULL
, bput_one
);
3089 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
3098 static int ext4_journalled_writepage(struct page
*page
,
3099 struct writeback_control
*wbc
)
3101 struct inode
*inode
= page
->mapping
->host
;
3102 loff_t size
= i_size_read(inode
);
3105 trace_mark(ext4_journalled_writepage
,
3106 "dev %s ino %lu page_index %lu",
3107 inode
->i_sb
->s_id
, inode
->i_ino
, page
->index
);
3108 J_ASSERT(PageLocked(page
));
3109 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
3110 len
= size
& ~PAGE_CACHE_MASK
;
3112 len
= PAGE_CACHE_SIZE
;
3114 if (page_has_buffers(page
)) {
3115 /* if page has buffers it should all be mapped
3116 * and allocated. If there are not buffers attached
3117 * to the page we know the page is dirty but it lost
3118 * buffers. That means that at some moment in time
3119 * after write_begin() / write_end() has been called
3120 * all buffers have been clean and thus they must have been
3121 * written at least once. So they are all mapped and we can
3122 * happily proceed with mapping them and writing the page.
3124 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
3125 ext4_bh_unmapped_or_delay
));
3128 if (ext4_journal_current_handle())
3131 if (PageChecked(page
)) {
3133 * It's mmapped pagecache. Add buffers and journal it. There
3134 * doesn't seem much point in redirtying the page here.
3136 ClearPageChecked(page
);
3137 return __ext4_journalled_writepage(page
, wbc
);
3140 * It may be a page full of checkpoint-mode buffers. We don't
3141 * really know unless we go poke around in the buffer_heads.
3142 * But block_write_full_page will do the right thing.
3144 return block_write_full_page(page
,
3145 ext4_normal_get_block_write
,
3149 redirty_page_for_writepage(wbc
, page
);
3154 static int ext4_readpage(struct file
*file
, struct page
*page
)
3156 return mpage_readpage(page
, ext4_get_block
);
3160 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3161 struct list_head
*pages
, unsigned nr_pages
)
3163 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3166 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3168 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3171 * If it's a full truncate we just forget about the pending dirtying
3174 ClearPageChecked(page
);
3177 jbd2_journal_invalidatepage(journal
, page
, offset
);
3179 block_invalidatepage(page
, offset
);
3182 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3184 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3186 WARN_ON(PageChecked(page
));
3187 if (!page_has_buffers(page
))
3190 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3192 return try_to_free_buffers(page
);
3196 * If the O_DIRECT write will extend the file then add this inode to the
3197 * orphan list. So recovery will truncate it back to the original size
3198 * if the machine crashes during the write.
3200 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3201 * crashes then stale disk data _may_ be exposed inside the file. But current
3202 * VFS code falls back into buffered path in that case so we are safe.
3204 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3205 const struct iovec
*iov
, loff_t offset
,
3206 unsigned long nr_segs
)
3208 struct file
*file
= iocb
->ki_filp
;
3209 struct inode
*inode
= file
->f_mapping
->host
;
3210 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3214 size_t count
= iov_length(iov
, nr_segs
);
3217 loff_t final_size
= offset
+ count
;
3219 if (final_size
> inode
->i_size
) {
3220 /* Credits for sb + inode write */
3221 handle
= ext4_journal_start(inode
, 2);
3222 if (IS_ERR(handle
)) {
3223 ret
= PTR_ERR(handle
);
3226 ret
= ext4_orphan_add(handle
, inode
);
3228 ext4_journal_stop(handle
);
3232 ei
->i_disksize
= inode
->i_size
;
3233 ext4_journal_stop(handle
);
3237 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3239 ext4_get_block
, NULL
);
3244 /* Credits for sb + inode write */
3245 handle
= ext4_journal_start(inode
, 2);
3246 if (IS_ERR(handle
)) {
3247 /* This is really bad luck. We've written the data
3248 * but cannot extend i_size. Bail out and pretend
3249 * the write failed... */
3250 ret
= PTR_ERR(handle
);
3254 ext4_orphan_del(handle
, inode
);
3256 loff_t end
= offset
+ ret
;
3257 if (end
> inode
->i_size
) {
3258 ei
->i_disksize
= end
;
3259 i_size_write(inode
, end
);
3261 * We're going to return a positive `ret'
3262 * here due to non-zero-length I/O, so there's
3263 * no way of reporting error returns from
3264 * ext4_mark_inode_dirty() to userspace. So
3267 ext4_mark_inode_dirty(handle
, inode
);
3270 err
= ext4_journal_stop(handle
);
3279 * Pages can be marked dirty completely asynchronously from ext4's journalling
3280 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3281 * much here because ->set_page_dirty is called under VFS locks. The page is
3282 * not necessarily locked.
3284 * We cannot just dirty the page and leave attached buffers clean, because the
3285 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3286 * or jbddirty because all the journalling code will explode.
3288 * So what we do is to mark the page "pending dirty" and next time writepage
3289 * is called, propagate that into the buffers appropriately.
3291 static int ext4_journalled_set_page_dirty(struct page
*page
)
3293 SetPageChecked(page
);
3294 return __set_page_dirty_nobuffers(page
);
3297 static const struct address_space_operations ext4_ordered_aops
= {
3298 .readpage
= ext4_readpage
,
3299 .readpages
= ext4_readpages
,
3300 .writepage
= ext4_normal_writepage
,
3301 .sync_page
= block_sync_page
,
3302 .write_begin
= ext4_write_begin
,
3303 .write_end
= ext4_ordered_write_end
,
3305 .invalidatepage
= ext4_invalidatepage
,
3306 .releasepage
= ext4_releasepage
,
3307 .direct_IO
= ext4_direct_IO
,
3308 .migratepage
= buffer_migrate_page
,
3309 .is_partially_uptodate
= block_is_partially_uptodate
,
3312 static const struct address_space_operations ext4_writeback_aops
= {
3313 .readpage
= ext4_readpage
,
3314 .readpages
= ext4_readpages
,
3315 .writepage
= ext4_normal_writepage
,
3316 .sync_page
= block_sync_page
,
3317 .write_begin
= ext4_write_begin
,
3318 .write_end
= ext4_writeback_write_end
,
3320 .invalidatepage
= ext4_invalidatepage
,
3321 .releasepage
= ext4_releasepage
,
3322 .direct_IO
= ext4_direct_IO
,
3323 .migratepage
= buffer_migrate_page
,
3324 .is_partially_uptodate
= block_is_partially_uptodate
,
3327 static const struct address_space_operations ext4_journalled_aops
= {
3328 .readpage
= ext4_readpage
,
3329 .readpages
= ext4_readpages
,
3330 .writepage
= ext4_journalled_writepage
,
3331 .sync_page
= block_sync_page
,
3332 .write_begin
= ext4_write_begin
,
3333 .write_end
= ext4_journalled_write_end
,
3334 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3336 .invalidatepage
= ext4_invalidatepage
,
3337 .releasepage
= ext4_releasepage
,
3338 .is_partially_uptodate
= block_is_partially_uptodate
,
3341 static const struct address_space_operations ext4_da_aops
= {
3342 .readpage
= ext4_readpage
,
3343 .readpages
= ext4_readpages
,
3344 .writepage
= ext4_da_writepage
,
3345 .writepages
= ext4_da_writepages
,
3346 .sync_page
= block_sync_page
,
3347 .write_begin
= ext4_da_write_begin
,
3348 .write_end
= ext4_da_write_end
,
3350 .invalidatepage
= ext4_da_invalidatepage
,
3351 .releasepage
= ext4_releasepage
,
3352 .direct_IO
= ext4_direct_IO
,
3353 .migratepage
= buffer_migrate_page
,
3354 .is_partially_uptodate
= block_is_partially_uptodate
,
3357 void ext4_set_aops(struct inode
*inode
)
3359 if (ext4_should_order_data(inode
) &&
3360 test_opt(inode
->i_sb
, DELALLOC
))
3361 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3362 else if (ext4_should_order_data(inode
))
3363 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3364 else if (ext4_should_writeback_data(inode
) &&
3365 test_opt(inode
->i_sb
, DELALLOC
))
3366 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3367 else if (ext4_should_writeback_data(inode
))
3368 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3370 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3374 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3375 * up to the end of the block which corresponds to `from'.
3376 * This required during truncate. We need to physically zero the tail end
3377 * of that block so it doesn't yield old data if the file is later grown.
3379 int ext4_block_truncate_page(handle_t
*handle
,
3380 struct address_space
*mapping
, loff_t from
)
3382 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3383 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3384 unsigned blocksize
, length
, pos
;
3386 struct inode
*inode
= mapping
->host
;
3387 struct buffer_head
*bh
;
3391 page
= grab_cache_page(mapping
, from
>> PAGE_CACHE_SHIFT
);
3395 blocksize
= inode
->i_sb
->s_blocksize
;
3396 length
= blocksize
- (offset
& (blocksize
- 1));
3397 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3400 * For "nobh" option, we can only work if we don't need to
3401 * read-in the page - otherwise we create buffers to do the IO.
3403 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3404 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3405 zero_user(page
, offset
, length
);
3406 set_page_dirty(page
);
3410 if (!page_has_buffers(page
))
3411 create_empty_buffers(page
, blocksize
, 0);
3413 /* Find the buffer that contains "offset" */
3414 bh
= page_buffers(page
);
3416 while (offset
>= pos
) {
3417 bh
= bh
->b_this_page
;
3423 if (buffer_freed(bh
)) {
3424 BUFFER_TRACE(bh
, "freed: skip");
3428 if (!buffer_mapped(bh
)) {
3429 BUFFER_TRACE(bh
, "unmapped");
3430 ext4_get_block(inode
, iblock
, bh
, 0);
3431 /* unmapped? It's a hole - nothing to do */
3432 if (!buffer_mapped(bh
)) {
3433 BUFFER_TRACE(bh
, "still unmapped");
3438 /* Ok, it's mapped. Make sure it's up-to-date */
3439 if (PageUptodate(page
))
3440 set_buffer_uptodate(bh
);
3442 if (!buffer_uptodate(bh
)) {
3444 ll_rw_block(READ
, 1, &bh
);
3446 /* Uhhuh. Read error. Complain and punt. */
3447 if (!buffer_uptodate(bh
))
3451 if (ext4_should_journal_data(inode
)) {
3452 BUFFER_TRACE(bh
, "get write access");
3453 err
= ext4_journal_get_write_access(handle
, bh
);
3458 zero_user(page
, offset
, length
);
3460 BUFFER_TRACE(bh
, "zeroed end of block");
3463 if (ext4_should_journal_data(inode
)) {
3464 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
3466 if (ext4_should_order_data(inode
))
3467 err
= ext4_jbd2_file_inode(handle
, inode
);
3468 mark_buffer_dirty(bh
);
3473 page_cache_release(page
);
3478 * Probably it should be a library function... search for first non-zero word
3479 * or memcmp with zero_page, whatever is better for particular architecture.
3482 static inline int all_zeroes(__le32
*p
, __le32
*q
)
3491 * ext4_find_shared - find the indirect blocks for partial truncation.
3492 * @inode: inode in question
3493 * @depth: depth of the affected branch
3494 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
3495 * @chain: place to store the pointers to partial indirect blocks
3496 * @top: place to the (detached) top of branch
3498 * This is a helper function used by ext4_truncate().
3500 * When we do truncate() we may have to clean the ends of several
3501 * indirect blocks but leave the blocks themselves alive. Block is
3502 * partially truncated if some data below the new i_size is refered
3503 * from it (and it is on the path to the first completely truncated
3504 * data block, indeed). We have to free the top of that path along
3505 * with everything to the right of the path. Since no allocation
3506 * past the truncation point is possible until ext4_truncate()
3507 * finishes, we may safely do the latter, but top of branch may
3508 * require special attention - pageout below the truncation point
3509 * might try to populate it.
3511 * We atomically detach the top of branch from the tree, store the
3512 * block number of its root in *@top, pointers to buffer_heads of
3513 * partially truncated blocks - in @chain[].bh and pointers to
3514 * their last elements that should not be removed - in
3515 * @chain[].p. Return value is the pointer to last filled element
3518 * The work left to caller to do the actual freeing of subtrees:
3519 * a) free the subtree starting from *@top
3520 * b) free the subtrees whose roots are stored in
3521 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
3522 * c) free the subtrees growing from the inode past the @chain[0].
3523 * (no partially truncated stuff there). */
3525 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
3526 ext4_lblk_t offsets
[4], Indirect chain
[4], __le32
*top
)
3528 Indirect
*partial
, *p
;
3532 /* Make k index the deepest non-null offest + 1 */
3533 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
3535 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
3536 /* Writer: pointers */
3538 partial
= chain
+ k
-1;
3540 * If the branch acquired continuation since we've looked at it -
3541 * fine, it should all survive and (new) top doesn't belong to us.
3543 if (!partial
->key
&& *partial
->p
)
3546 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
3549 * OK, we've found the last block that must survive. The rest of our
3550 * branch should be detached before unlocking. However, if that rest
3551 * of branch is all ours and does not grow immediately from the inode
3552 * it's easier to cheat and just decrement partial->p.
3554 if (p
== chain
+ k
- 1 && p
> chain
) {
3558 /* Nope, don't do this in ext4. Must leave the tree intact */
3565 while (partial
> p
) {
3566 brelse(partial
->bh
);
3574 * Zero a number of block pointers in either an inode or an indirect block.
3575 * If we restart the transaction we must again get write access to the
3576 * indirect block for further modification.
3578 * We release `count' blocks on disk, but (last - first) may be greater
3579 * than `count' because there can be holes in there.
3581 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
3582 struct buffer_head
*bh
, ext4_fsblk_t block_to_free
,
3583 unsigned long count
, __le32
*first
, __le32
*last
)
3586 if (try_to_extend_transaction(handle
, inode
)) {
3588 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
3589 ext4_handle_dirty_metadata(handle
, inode
, bh
);
3591 ext4_mark_inode_dirty(handle
, inode
);
3592 ext4_journal_test_restart(handle
, inode
);
3594 BUFFER_TRACE(bh
, "retaking write access");
3595 ext4_journal_get_write_access(handle
, bh
);
3600 * Any buffers which are on the journal will be in memory. We find
3601 * them on the hash table so jbd2_journal_revoke() will run jbd2_journal_forget()
3602 * on them. We've already detached each block from the file, so
3603 * bforget() in jbd2_journal_forget() should be safe.
3605 * AKPM: turn on bforget in jbd2_journal_forget()!!!
3607 for (p
= first
; p
< last
; p
++) {
3608 u32 nr
= le32_to_cpu(*p
);
3610 struct buffer_head
*tbh
;
3613 tbh
= sb_find_get_block(inode
->i_sb
, nr
);
3614 ext4_forget(handle
, 0, inode
, tbh
, nr
);
3618 ext4_free_blocks(handle
, inode
, block_to_free
, count
, 0);
3622 * ext4_free_data - free a list of data blocks
3623 * @handle: handle for this transaction
3624 * @inode: inode we are dealing with
3625 * @this_bh: indirect buffer_head which contains *@first and *@last
3626 * @first: array of block numbers
3627 * @last: points immediately past the end of array
3629 * We are freeing all blocks refered from that array (numbers are stored as
3630 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
3632 * We accumulate contiguous runs of blocks to free. Conveniently, if these
3633 * blocks are contiguous then releasing them at one time will only affect one
3634 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
3635 * actually use a lot of journal space.
3637 * @this_bh will be %NULL if @first and @last point into the inode's direct
3640 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
3641 struct buffer_head
*this_bh
,
3642 __le32
*first
, __le32
*last
)
3644 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
3645 unsigned long count
= 0; /* Number of blocks in the run */
3646 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
3649 ext4_fsblk_t nr
; /* Current block # */
3650 __le32
*p
; /* Pointer into inode/ind
3651 for current block */
3654 if (this_bh
) { /* For indirect block */
3655 BUFFER_TRACE(this_bh
, "get_write_access");
3656 err
= ext4_journal_get_write_access(handle
, this_bh
);
3657 /* Important: if we can't update the indirect pointers
3658 * to the blocks, we can't free them. */
3663 for (p
= first
; p
< last
; p
++) {
3664 nr
= le32_to_cpu(*p
);
3666 /* accumulate blocks to free if they're contiguous */
3669 block_to_free_p
= p
;
3671 } else if (nr
== block_to_free
+ count
) {
3674 ext4_clear_blocks(handle
, inode
, this_bh
,
3676 count
, block_to_free_p
, p
);
3678 block_to_free_p
= p
;
3685 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
3686 count
, block_to_free_p
, p
);
3689 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
3692 * The buffer head should have an attached journal head at this
3693 * point. However, if the data is corrupted and an indirect
3694 * block pointed to itself, it would have been detached when
3695 * the block was cleared. Check for this instead of OOPSing.
3697 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
3698 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
3700 ext4_error(inode
->i_sb
, __func__
,
3701 "circular indirect block detected, "
3702 "inode=%lu, block=%llu",
3704 (unsigned long long) this_bh
->b_blocknr
);
3709 * ext4_free_branches - free an array of branches
3710 * @handle: JBD handle for this transaction
3711 * @inode: inode we are dealing with
3712 * @parent_bh: the buffer_head which contains *@first and *@last
3713 * @first: array of block numbers
3714 * @last: pointer immediately past the end of array
3715 * @depth: depth of the branches to free
3717 * We are freeing all blocks refered from these branches (numbers are
3718 * stored as little-endian 32-bit) and updating @inode->i_blocks
3721 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
3722 struct buffer_head
*parent_bh
,
3723 __le32
*first
, __le32
*last
, int depth
)
3728 if (ext4_handle_is_aborted(handle
))
3732 struct buffer_head
*bh
;
3733 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
3735 while (--p
>= first
) {
3736 nr
= le32_to_cpu(*p
);
3738 continue; /* A hole */
3740 /* Go read the buffer for the next level down */
3741 bh
= sb_bread(inode
->i_sb
, nr
);
3744 * A read failure? Report error and clear slot
3748 ext4_error(inode
->i_sb
, "ext4_free_branches",
3749 "Read failure, inode=%lu, block=%llu",
3754 /* This zaps the entire block. Bottom up. */
3755 BUFFER_TRACE(bh
, "free child branches");
3756 ext4_free_branches(handle
, inode
, bh
,
3757 (__le32
*) bh
->b_data
,
3758 (__le32
*) bh
->b_data
+ addr_per_block
,
3762 * We've probably journalled the indirect block several
3763 * times during the truncate. But it's no longer
3764 * needed and we now drop it from the transaction via
3765 * jbd2_journal_revoke().
3767 * That's easy if it's exclusively part of this
3768 * transaction. But if it's part of the committing
3769 * transaction then jbd2_journal_forget() will simply
3770 * brelse() it. That means that if the underlying
3771 * block is reallocated in ext4_get_block(),
3772 * unmap_underlying_metadata() will find this block
3773 * and will try to get rid of it. damn, damn.
3775 * If this block has already been committed to the
3776 * journal, a revoke record will be written. And
3777 * revoke records must be emitted *before* clearing
3778 * this block's bit in the bitmaps.
3780 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
3783 * Everything below this this pointer has been
3784 * released. Now let this top-of-subtree go.
3786 * We want the freeing of this indirect block to be
3787 * atomic in the journal with the updating of the
3788 * bitmap block which owns it. So make some room in
3791 * We zero the parent pointer *after* freeing its
3792 * pointee in the bitmaps, so if extend_transaction()
3793 * for some reason fails to put the bitmap changes and
3794 * the release into the same transaction, recovery
3795 * will merely complain about releasing a free block,
3796 * rather than leaking blocks.
3798 if (ext4_handle_is_aborted(handle
))
3800 if (try_to_extend_transaction(handle
, inode
)) {
3801 ext4_mark_inode_dirty(handle
, inode
);
3802 ext4_journal_test_restart(handle
, inode
);
3805 ext4_free_blocks(handle
, inode
, nr
, 1, 1);
3809 * The block which we have just freed is
3810 * pointed to by an indirect block: journal it
3812 BUFFER_TRACE(parent_bh
, "get_write_access");
3813 if (!ext4_journal_get_write_access(handle
,
3816 BUFFER_TRACE(parent_bh
,
3817 "call ext4_handle_dirty_metadata");
3818 ext4_handle_dirty_metadata(handle
,
3825 /* We have reached the bottom of the tree. */
3826 BUFFER_TRACE(parent_bh
, "free data blocks");
3827 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
3831 int ext4_can_truncate(struct inode
*inode
)
3833 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
3835 if (S_ISREG(inode
->i_mode
))
3837 if (S_ISDIR(inode
->i_mode
))
3839 if (S_ISLNK(inode
->i_mode
))
3840 return !ext4_inode_is_fast_symlink(inode
);
3847 * We block out ext4_get_block() block instantiations across the entire
3848 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3849 * simultaneously on behalf of the same inode.
3851 * As we work through the truncate and commmit bits of it to the journal there
3852 * is one core, guiding principle: the file's tree must always be consistent on
3853 * disk. We must be able to restart the truncate after a crash.
3855 * The file's tree may be transiently inconsistent in memory (although it
3856 * probably isn't), but whenever we close off and commit a journal transaction,
3857 * the contents of (the filesystem + the journal) must be consistent and
3858 * restartable. It's pretty simple, really: bottom up, right to left (although
3859 * left-to-right works OK too).
3861 * Note that at recovery time, journal replay occurs *before* the restart of
3862 * truncate against the orphan inode list.
3864 * The committed inode has the new, desired i_size (which is the same as
3865 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3866 * that this inode's truncate did not complete and it will again call
3867 * ext4_truncate() to have another go. So there will be instantiated blocks
3868 * to the right of the truncation point in a crashed ext4 filesystem. But
3869 * that's fine - as long as they are linked from the inode, the post-crash
3870 * ext4_truncate() run will find them and release them.
3872 void ext4_truncate(struct inode
*inode
)
3875 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3876 __le32
*i_data
= ei
->i_data
;
3877 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
3878 struct address_space
*mapping
= inode
->i_mapping
;
3879 ext4_lblk_t offsets
[4];
3884 ext4_lblk_t last_block
;
3885 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
3887 if (!ext4_can_truncate(inode
))
3890 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
3891 ei
->i_state
|= EXT4_STATE_DA_ALLOC_CLOSE
;
3893 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
3894 ext4_ext_truncate(inode
);
3898 handle
= start_transaction(inode
);
3900 return; /* AKPM: return what? */
3902 last_block
= (inode
->i_size
+ blocksize
-1)
3903 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
3905 if (inode
->i_size
& (blocksize
- 1))
3906 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
3909 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
3911 goto out_stop
; /* error */
3914 * OK. This truncate is going to happen. We add the inode to the
3915 * orphan list, so that if this truncate spans multiple transactions,
3916 * and we crash, we will resume the truncate when the filesystem
3917 * recovers. It also marks the inode dirty, to catch the new size.
3919 * Implication: the file must always be in a sane, consistent
3920 * truncatable state while each transaction commits.
3922 if (ext4_orphan_add(handle
, inode
))
3926 * From here we block out all ext4_get_block() callers who want to
3927 * modify the block allocation tree.
3929 down_write(&ei
->i_data_sem
);
3931 ext4_discard_preallocations(inode
);
3934 * The orphan list entry will now protect us from any crash which
3935 * occurs before the truncate completes, so it is now safe to propagate
3936 * the new, shorter inode size (held for now in i_size) into the
3937 * on-disk inode. We do this via i_disksize, which is the value which
3938 * ext4 *really* writes onto the disk inode.
3940 ei
->i_disksize
= inode
->i_size
;
3942 if (n
== 1) { /* direct blocks */
3943 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
3944 i_data
+ EXT4_NDIR_BLOCKS
);
3948 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
3949 /* Kill the top of shared branch (not detached) */
3951 if (partial
== chain
) {
3952 /* Shared branch grows from the inode */
3953 ext4_free_branches(handle
, inode
, NULL
,
3954 &nr
, &nr
+1, (chain
+n
-1) - partial
);
3957 * We mark the inode dirty prior to restart,
3958 * and prior to stop. No need for it here.
3961 /* Shared branch grows from an indirect block */
3962 BUFFER_TRACE(partial
->bh
, "get_write_access");
3963 ext4_free_branches(handle
, inode
, partial
->bh
,
3965 partial
->p
+1, (chain
+n
-1) - partial
);
3968 /* Clear the ends of indirect blocks on the shared branch */
3969 while (partial
> chain
) {
3970 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
3971 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
3972 (chain
+n
-1) - partial
);
3973 BUFFER_TRACE(partial
->bh
, "call brelse");
3974 brelse (partial
->bh
);
3978 /* Kill the remaining (whole) subtrees */
3979 switch (offsets
[0]) {
3981 nr
= i_data
[EXT4_IND_BLOCK
];
3983 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
3984 i_data
[EXT4_IND_BLOCK
] = 0;
3986 case EXT4_IND_BLOCK
:
3987 nr
= i_data
[EXT4_DIND_BLOCK
];
3989 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
3990 i_data
[EXT4_DIND_BLOCK
] = 0;
3992 case EXT4_DIND_BLOCK
:
3993 nr
= i_data
[EXT4_TIND_BLOCK
];
3995 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
3996 i_data
[EXT4_TIND_BLOCK
] = 0;
3998 case EXT4_TIND_BLOCK
:
4002 up_write(&ei
->i_data_sem
);
4003 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4004 ext4_mark_inode_dirty(handle
, inode
);
4007 * In a multi-transaction truncate, we only make the final transaction
4011 ext4_handle_sync(handle
);
4014 * If this was a simple ftruncate(), and the file will remain alive
4015 * then we need to clear up the orphan record which we created above.
4016 * However, if this was a real unlink then we were called by
4017 * ext4_delete_inode(), and we allow that function to clean up the
4018 * orphan info for us.
4021 ext4_orphan_del(handle
, inode
);
4023 ext4_journal_stop(handle
);
4027 * ext4_get_inode_loc returns with an extra refcount against the inode's
4028 * underlying buffer_head on success. If 'in_mem' is true, we have all
4029 * data in memory that is needed to recreate the on-disk version of this
4032 static int __ext4_get_inode_loc(struct inode
*inode
,
4033 struct ext4_iloc
*iloc
, int in_mem
)
4035 struct ext4_group_desc
*gdp
;
4036 struct buffer_head
*bh
;
4037 struct super_block
*sb
= inode
->i_sb
;
4039 int inodes_per_block
, inode_offset
;
4042 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4045 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4046 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4051 * Figure out the offset within the block group inode table
4053 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4054 inode_offset
= ((inode
->i_ino
- 1) %
4055 EXT4_INODES_PER_GROUP(sb
));
4056 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4057 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4059 bh
= sb_getblk(sb
, block
);
4061 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
4062 "inode block - inode=%lu, block=%llu",
4063 inode
->i_ino
, block
);
4066 if (!buffer_uptodate(bh
)) {
4070 * If the buffer has the write error flag, we have failed
4071 * to write out another inode in the same block. In this
4072 * case, we don't have to read the block because we may
4073 * read the old inode data successfully.
4075 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4076 set_buffer_uptodate(bh
);
4078 if (buffer_uptodate(bh
)) {
4079 /* someone brought it uptodate while we waited */
4085 * If we have all information of the inode in memory and this
4086 * is the only valid inode in the block, we need not read the
4090 struct buffer_head
*bitmap_bh
;
4093 start
= inode_offset
& ~(inodes_per_block
- 1);
4095 /* Is the inode bitmap in cache? */
4096 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4101 * If the inode bitmap isn't in cache then the
4102 * optimisation may end up performing two reads instead
4103 * of one, so skip it.
4105 if (!buffer_uptodate(bitmap_bh
)) {
4109 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4110 if (i
== inode_offset
)
4112 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4116 if (i
== start
+ inodes_per_block
) {
4117 /* all other inodes are free, so skip I/O */
4118 memset(bh
->b_data
, 0, bh
->b_size
);
4119 set_buffer_uptodate(bh
);
4127 * If we need to do any I/O, try to pre-readahead extra
4128 * blocks from the inode table.
4130 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4131 ext4_fsblk_t b
, end
, table
;
4134 table
= ext4_inode_table(sb
, gdp
);
4135 /* Make sure s_inode_readahead_blks is a power of 2 */
4136 while (EXT4_SB(sb
)->s_inode_readahead_blks
&
4137 (EXT4_SB(sb
)->s_inode_readahead_blks
-1))
4138 EXT4_SB(sb
)->s_inode_readahead_blks
=
4139 (EXT4_SB(sb
)->s_inode_readahead_blks
&
4140 (EXT4_SB(sb
)->s_inode_readahead_blks
-1));
4141 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4144 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4145 num
= EXT4_INODES_PER_GROUP(sb
);
4146 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4147 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4148 num
-= ext4_itable_unused_count(sb
, gdp
);
4149 table
+= num
/ inodes_per_block
;
4153 sb_breadahead(sb
, b
++);
4157 * There are other valid inodes in the buffer, this inode
4158 * has in-inode xattrs, or we don't have this inode in memory.
4159 * Read the block from disk.
4162 bh
->b_end_io
= end_buffer_read_sync
;
4163 submit_bh(READ_META
, bh
);
4165 if (!buffer_uptodate(bh
)) {
4166 ext4_error(sb
, __func__
,
4167 "unable to read inode block - inode=%lu, "
4168 "block=%llu", inode
->i_ino
, block
);
4178 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4180 /* We have all inode data except xattrs in memory here. */
4181 return __ext4_get_inode_loc(inode
, iloc
,
4182 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4185 void ext4_set_inode_flags(struct inode
*inode
)
4187 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4189 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4190 if (flags
& EXT4_SYNC_FL
)
4191 inode
->i_flags
|= S_SYNC
;
4192 if (flags
& EXT4_APPEND_FL
)
4193 inode
->i_flags
|= S_APPEND
;
4194 if (flags
& EXT4_IMMUTABLE_FL
)
4195 inode
->i_flags
|= S_IMMUTABLE
;
4196 if (flags
& EXT4_NOATIME_FL
)
4197 inode
->i_flags
|= S_NOATIME
;
4198 if (flags
& EXT4_DIRSYNC_FL
)
4199 inode
->i_flags
|= S_DIRSYNC
;
4202 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4203 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4205 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4207 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4208 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4210 ei
->i_flags
|= EXT4_SYNC_FL
;
4211 if (flags
& S_APPEND
)
4212 ei
->i_flags
|= EXT4_APPEND_FL
;
4213 if (flags
& S_IMMUTABLE
)
4214 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4215 if (flags
& S_NOATIME
)
4216 ei
->i_flags
|= EXT4_NOATIME_FL
;
4217 if (flags
& S_DIRSYNC
)
4218 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4220 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4221 struct ext4_inode_info
*ei
)
4224 struct inode
*inode
= &(ei
->vfs_inode
);
4225 struct super_block
*sb
= inode
->i_sb
;
4227 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4228 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4229 /* we are using combined 48 bit field */
4230 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4231 le32_to_cpu(raw_inode
->i_blocks_lo
);
4232 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4233 /* i_blocks represent file system block size */
4234 return i_blocks
<< (inode
->i_blkbits
- 9);
4239 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4243 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4245 struct ext4_iloc iloc
;
4246 struct ext4_inode
*raw_inode
;
4247 struct ext4_inode_info
*ei
;
4248 struct buffer_head
*bh
;
4249 struct inode
*inode
;
4253 inode
= iget_locked(sb
, ino
);
4255 return ERR_PTR(-ENOMEM
);
4256 if (!(inode
->i_state
& I_NEW
))
4260 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4261 ei
->i_acl
= EXT4_ACL_NOT_CACHED
;
4262 ei
->i_default_acl
= EXT4_ACL_NOT_CACHED
;
4265 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4269 raw_inode
= ext4_raw_inode(&iloc
);
4270 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4271 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4272 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4273 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4274 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4275 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4277 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4280 ei
->i_dir_start_lookup
= 0;
4281 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4282 /* We now have enough fields to check if the inode was active or not.
4283 * This is needed because nfsd might try to access dead inodes
4284 * the test is that same one that e2fsck uses
4285 * NeilBrown 1999oct15
4287 if (inode
->i_nlink
== 0) {
4288 if (inode
->i_mode
== 0 ||
4289 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4290 /* this inode is deleted */
4295 /* The only unlinked inodes we let through here have
4296 * valid i_mode and are being read by the orphan
4297 * recovery code: that's fine, we're about to complete
4298 * the process of deleting those. */
4300 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4301 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4302 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4303 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
4304 cpu_to_le32(EXT4_OS_HURD
)) {
4306 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4308 inode
->i_size
= ext4_isize(raw_inode
);
4309 ei
->i_disksize
= inode
->i_size
;
4310 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4311 ei
->i_block_group
= iloc
.block_group
;
4313 * NOTE! The in-memory inode i_data array is in little-endian order
4314 * even on big-endian machines: we do NOT byteswap the block numbers!
4316 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4317 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4318 INIT_LIST_HEAD(&ei
->i_orphan
);
4320 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4321 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4322 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4323 EXT4_INODE_SIZE(inode
->i_sb
)) {
4328 if (ei
->i_extra_isize
== 0) {
4329 /* The extra space is currently unused. Use it. */
4330 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4331 EXT4_GOOD_OLD_INODE_SIZE
;
4333 __le32
*magic
= (void *)raw_inode
+
4334 EXT4_GOOD_OLD_INODE_SIZE
+
4336 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4337 ei
->i_state
|= EXT4_STATE_XATTR
;
4340 ei
->i_extra_isize
= 0;
4342 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4343 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4344 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4345 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4347 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4348 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4349 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4351 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4354 if (S_ISREG(inode
->i_mode
)) {
4355 inode
->i_op
= &ext4_file_inode_operations
;
4356 inode
->i_fop
= &ext4_file_operations
;
4357 ext4_set_aops(inode
);
4358 } else if (S_ISDIR(inode
->i_mode
)) {
4359 inode
->i_op
= &ext4_dir_inode_operations
;
4360 inode
->i_fop
= &ext4_dir_operations
;
4361 } else if (S_ISLNK(inode
->i_mode
)) {
4362 if (ext4_inode_is_fast_symlink(inode
)) {
4363 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4364 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4365 sizeof(ei
->i_data
) - 1);
4367 inode
->i_op
= &ext4_symlink_inode_operations
;
4368 ext4_set_aops(inode
);
4371 inode
->i_op
= &ext4_special_inode_operations
;
4372 if (raw_inode
->i_block
[0])
4373 init_special_inode(inode
, inode
->i_mode
,
4374 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4376 init_special_inode(inode
, inode
->i_mode
,
4377 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4380 ext4_set_inode_flags(inode
);
4381 unlock_new_inode(inode
);
4386 return ERR_PTR(ret
);
4389 static int ext4_inode_blocks_set(handle_t
*handle
,
4390 struct ext4_inode
*raw_inode
,
4391 struct ext4_inode_info
*ei
)
4393 struct inode
*inode
= &(ei
->vfs_inode
);
4394 u64 i_blocks
= inode
->i_blocks
;
4395 struct super_block
*sb
= inode
->i_sb
;
4397 if (i_blocks
<= ~0U) {
4399 * i_blocks can be represnted in a 32 bit variable
4400 * as multiple of 512 bytes
4402 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4403 raw_inode
->i_blocks_high
= 0;
4404 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4407 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
4410 if (i_blocks
<= 0xffffffffffffULL
) {
4412 * i_blocks can be represented in a 48 bit variable
4413 * as multiple of 512 bytes
4415 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4416 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4417 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4419 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
4420 /* i_block is stored in file system block size */
4421 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
4422 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4423 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4429 * Post the struct inode info into an on-disk inode location in the
4430 * buffer-cache. This gobbles the caller's reference to the
4431 * buffer_head in the inode location struct.
4433 * The caller must have write access to iloc->bh.
4435 static int ext4_do_update_inode(handle_t
*handle
,
4436 struct inode
*inode
,
4437 struct ext4_iloc
*iloc
)
4439 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
4440 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4441 struct buffer_head
*bh
= iloc
->bh
;
4442 int err
= 0, rc
, block
;
4444 /* For fields not not tracking in the in-memory inode,
4445 * initialise them to zero for new inodes. */
4446 if (ei
->i_state
& EXT4_STATE_NEW
)
4447 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
4449 ext4_get_inode_flags(ei
);
4450 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
4451 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4452 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
4453 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
4455 * Fix up interoperability with old kernels. Otherwise, old inodes get
4456 * re-used with the upper 16 bits of the uid/gid intact
4459 raw_inode
->i_uid_high
=
4460 cpu_to_le16(high_16_bits(inode
->i_uid
));
4461 raw_inode
->i_gid_high
=
4462 cpu_to_le16(high_16_bits(inode
->i_gid
));
4464 raw_inode
->i_uid_high
= 0;
4465 raw_inode
->i_gid_high
= 0;
4468 raw_inode
->i_uid_low
=
4469 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
4470 raw_inode
->i_gid_low
=
4471 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
4472 raw_inode
->i_uid_high
= 0;
4473 raw_inode
->i_gid_high
= 0;
4475 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
4477 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
4478 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
4479 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
4480 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
4482 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
4484 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
4485 /* clear the migrate flag in the raw_inode */
4486 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
& ~EXT4_EXT_MIGRATE
);
4487 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
4488 cpu_to_le32(EXT4_OS_HURD
))
4489 raw_inode
->i_file_acl_high
=
4490 cpu_to_le16(ei
->i_file_acl
>> 32);
4491 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
4492 ext4_isize_set(raw_inode
, ei
->i_disksize
);
4493 if (ei
->i_disksize
> 0x7fffffffULL
) {
4494 struct super_block
*sb
= inode
->i_sb
;
4495 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4496 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
4497 EXT4_SB(sb
)->s_es
->s_rev_level
==
4498 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
4499 /* If this is the first large file
4500 * created, add a flag to the superblock.
4502 err
= ext4_journal_get_write_access(handle
,
4503 EXT4_SB(sb
)->s_sbh
);
4506 ext4_update_dynamic_rev(sb
);
4507 EXT4_SET_RO_COMPAT_FEATURE(sb
,
4508 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
4510 ext4_handle_sync(handle
);
4511 err
= ext4_handle_dirty_metadata(handle
, inode
,
4512 EXT4_SB(sb
)->s_sbh
);
4515 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
4516 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
4517 if (old_valid_dev(inode
->i_rdev
)) {
4518 raw_inode
->i_block
[0] =
4519 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
4520 raw_inode
->i_block
[1] = 0;
4522 raw_inode
->i_block
[0] = 0;
4523 raw_inode
->i_block
[1] =
4524 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
4525 raw_inode
->i_block
[2] = 0;
4527 } else for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4528 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
4530 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
4531 if (ei
->i_extra_isize
) {
4532 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4533 raw_inode
->i_version_hi
=
4534 cpu_to_le32(inode
->i_version
>> 32);
4535 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
4538 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4539 rc
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
4542 ei
->i_state
&= ~EXT4_STATE_NEW
;
4546 ext4_std_error(inode
->i_sb
, err
);
4551 * ext4_write_inode()
4553 * We are called from a few places:
4555 * - Within generic_file_write() for O_SYNC files.
4556 * Here, there will be no transaction running. We wait for any running
4557 * trasnaction to commit.
4559 * - Within sys_sync(), kupdate and such.
4560 * We wait on commit, if tol to.
4562 * - Within prune_icache() (PF_MEMALLOC == true)
4563 * Here we simply return. We can't afford to block kswapd on the
4566 * In all cases it is actually safe for us to return without doing anything,
4567 * because the inode has been copied into a raw inode buffer in
4568 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4571 * Note that we are absolutely dependent upon all inode dirtiers doing the
4572 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4573 * which we are interested.
4575 * It would be a bug for them to not do this. The code:
4577 * mark_inode_dirty(inode)
4579 * inode->i_size = expr;
4581 * is in error because a kswapd-driven write_inode() could occur while
4582 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4583 * will no longer be on the superblock's dirty inode list.
4585 int ext4_write_inode(struct inode
*inode
, int wait
)
4587 if (current
->flags
& PF_MEMALLOC
)
4590 if (ext4_journal_current_handle()) {
4591 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4599 return ext4_force_commit(inode
->i_sb
);
4602 int __ext4_write_dirty_metadata(struct inode
*inode
, struct buffer_head
*bh
)
4606 mark_buffer_dirty(bh
);
4607 if (inode
&& inode_needs_sync(inode
)) {
4608 sync_dirty_buffer(bh
);
4609 if (buffer_req(bh
) && !buffer_uptodate(bh
)) {
4610 ext4_error(inode
->i_sb
, __func__
,
4611 "IO error syncing inode, "
4612 "inode=%lu, block=%llu",
4614 (unsigned long long)bh
->b_blocknr
);
4624 * Called from notify_change.
4626 * We want to trap VFS attempts to truncate the file as soon as
4627 * possible. In particular, we want to make sure that when the VFS
4628 * shrinks i_size, we put the inode on the orphan list and modify
4629 * i_disksize immediately, so that during the subsequent flushing of
4630 * dirty pages and freeing of disk blocks, we can guarantee that any
4631 * commit will leave the blocks being flushed in an unused state on
4632 * disk. (On recovery, the inode will get truncated and the blocks will
4633 * be freed, so we have a strong guarantee that no future commit will
4634 * leave these blocks visible to the user.)
4636 * Another thing we have to assure is that if we are in ordered mode
4637 * and inode is still attached to the committing transaction, we must
4638 * we start writeout of all the dirty pages which are being truncated.
4639 * This way we are sure that all the data written in the previous
4640 * transaction are already on disk (truncate waits for pages under
4643 * Called with inode->i_mutex down.
4645 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
4647 struct inode
*inode
= dentry
->d_inode
;
4649 const unsigned int ia_valid
= attr
->ia_valid
;
4651 error
= inode_change_ok(inode
, attr
);
4655 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
4656 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
4659 /* (user+group)*(old+new) structure, inode write (sb,
4660 * inode block, ? - but truncate inode update has it) */
4661 handle
= ext4_journal_start(inode
, 2*(EXT4_QUOTA_INIT_BLOCKS(inode
->i_sb
)+
4662 EXT4_QUOTA_DEL_BLOCKS(inode
->i_sb
))+3);
4663 if (IS_ERR(handle
)) {
4664 error
= PTR_ERR(handle
);
4667 error
= DQUOT_TRANSFER(inode
, attr
) ? -EDQUOT
: 0;
4669 ext4_journal_stop(handle
);
4672 /* Update corresponding info in inode so that everything is in
4673 * one transaction */
4674 if (attr
->ia_valid
& ATTR_UID
)
4675 inode
->i_uid
= attr
->ia_uid
;
4676 if (attr
->ia_valid
& ATTR_GID
)
4677 inode
->i_gid
= attr
->ia_gid
;
4678 error
= ext4_mark_inode_dirty(handle
, inode
);
4679 ext4_journal_stop(handle
);
4682 if (attr
->ia_valid
& ATTR_SIZE
) {
4683 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
4684 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
4686 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
4693 if (S_ISREG(inode
->i_mode
) &&
4694 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
4697 handle
= ext4_journal_start(inode
, 3);
4698 if (IS_ERR(handle
)) {
4699 error
= PTR_ERR(handle
);
4703 error
= ext4_orphan_add(handle
, inode
);
4704 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
4705 rc
= ext4_mark_inode_dirty(handle
, inode
);
4708 ext4_journal_stop(handle
);
4710 if (ext4_should_order_data(inode
)) {
4711 error
= ext4_begin_ordered_truncate(inode
,
4714 /* Do as much error cleanup as possible */
4715 handle
= ext4_journal_start(inode
, 3);
4716 if (IS_ERR(handle
)) {
4717 ext4_orphan_del(NULL
, inode
);
4720 ext4_orphan_del(handle
, inode
);
4721 ext4_journal_stop(handle
);
4727 rc
= inode_setattr(inode
, attr
);
4729 /* If inode_setattr's call to ext4_truncate failed to get a
4730 * transaction handle at all, we need to clean up the in-core
4731 * orphan list manually. */
4733 ext4_orphan_del(NULL
, inode
);
4735 if (!rc
&& (ia_valid
& ATTR_MODE
))
4736 rc
= ext4_acl_chmod(inode
);
4739 ext4_std_error(inode
->i_sb
, error
);
4745 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
4748 struct inode
*inode
;
4749 unsigned long delalloc_blocks
;
4751 inode
= dentry
->d_inode
;
4752 generic_fillattr(inode
, stat
);
4755 * We can't update i_blocks if the block allocation is delayed
4756 * otherwise in the case of system crash before the real block
4757 * allocation is done, we will have i_blocks inconsistent with
4758 * on-disk file blocks.
4759 * We always keep i_blocks updated together with real
4760 * allocation. But to not confuse with user, stat
4761 * will return the blocks that include the delayed allocation
4762 * blocks for this file.
4764 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
4765 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
4766 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
4768 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
4772 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
4777 /* if nrblocks are contiguous */
4780 * With N contiguous data blocks, it need at most
4781 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
4782 * 2 dindirect blocks
4785 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4786 return indirects
+ 3;
4789 * if nrblocks are not contiguous, worse case, each block touch
4790 * a indirect block, and each indirect block touch a double indirect
4791 * block, plus a triple indirect block
4793 indirects
= nrblocks
* 2 + 1;
4797 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4799 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
4800 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
4801 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
4805 * Account for index blocks, block groups bitmaps and block group
4806 * descriptor blocks if modify datablocks and index blocks
4807 * worse case, the indexs blocks spread over different block groups
4809 * If datablocks are discontiguous, they are possible to spread over
4810 * different block groups too. If they are contiugous, with flexbg,
4811 * they could still across block group boundary.
4813 * Also account for superblock, inode, quota and xattr blocks
4815 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4817 int groups
, gdpblocks
;
4822 * How many index blocks need to touch to modify nrblocks?
4823 * The "Chunk" flag indicating whether the nrblocks is
4824 * physically contiguous on disk
4826 * For Direct IO and fallocate, they calls get_block to allocate
4827 * one single extent at a time, so they could set the "Chunk" flag
4829 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
4834 * Now let's see how many group bitmaps and group descriptors need
4844 if (groups
> EXT4_SB(inode
->i_sb
)->s_groups_count
)
4845 groups
= EXT4_SB(inode
->i_sb
)->s_groups_count
;
4846 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
4847 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
4849 /* bitmaps and block group descriptor blocks */
4850 ret
+= groups
+ gdpblocks
;
4852 /* Blocks for super block, inode, quota and xattr blocks */
4853 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
4859 * Calulate the total number of credits to reserve to fit
4860 * the modification of a single pages into a single transaction,
4861 * which may include multiple chunks of block allocations.
4863 * This could be called via ext4_write_begin()
4865 * We need to consider the worse case, when
4866 * one new block per extent.
4868 int ext4_writepage_trans_blocks(struct inode
*inode
)
4870 int bpp
= ext4_journal_blocks_per_page(inode
);
4873 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
4875 /* Account for data blocks for journalled mode */
4876 if (ext4_should_journal_data(inode
))
4882 * Calculate the journal credits for a chunk of data modification.
4884 * This is called from DIO, fallocate or whoever calling
4885 * ext4_get_blocks_wrap() to map/allocate a chunk of contigous disk blocks.
4887 * journal buffers for data blocks are not included here, as DIO
4888 * and fallocate do no need to journal data buffers.
4890 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
4892 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
4896 * The caller must have previously called ext4_reserve_inode_write().
4897 * Give this, we know that the caller already has write access to iloc->bh.
4899 int ext4_mark_iloc_dirty(handle_t
*handle
,
4900 struct inode
*inode
, struct ext4_iloc
*iloc
)
4904 if (test_opt(inode
->i_sb
, I_VERSION
))
4905 inode_inc_iversion(inode
);
4907 /* the do_update_inode consumes one bh->b_count */
4910 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4911 err
= ext4_do_update_inode(handle
, inode
, iloc
);
4917 * On success, We end up with an outstanding reference count against
4918 * iloc->bh. This _must_ be cleaned up later.
4922 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
4923 struct ext4_iloc
*iloc
)
4927 err
= ext4_get_inode_loc(inode
, iloc
);
4929 BUFFER_TRACE(iloc
->bh
, "get_write_access");
4930 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
4936 ext4_std_error(inode
->i_sb
, err
);
4941 * Expand an inode by new_extra_isize bytes.
4942 * Returns 0 on success or negative error number on failure.
4944 static int ext4_expand_extra_isize(struct inode
*inode
,
4945 unsigned int new_extra_isize
,
4946 struct ext4_iloc iloc
,
4949 struct ext4_inode
*raw_inode
;
4950 struct ext4_xattr_ibody_header
*header
;
4951 struct ext4_xattr_entry
*entry
;
4953 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
4956 raw_inode
= ext4_raw_inode(&iloc
);
4958 header
= IHDR(inode
, raw_inode
);
4959 entry
= IFIRST(header
);
4961 /* No extended attributes present */
4962 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
4963 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
4964 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
4966 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
4970 /* try to expand with EAs present */
4971 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
4976 * What we do here is to mark the in-core inode as clean with respect to inode
4977 * dirtiness (it may still be data-dirty).
4978 * This means that the in-core inode may be reaped by prune_icache
4979 * without having to perform any I/O. This is a very good thing,
4980 * because *any* task may call prune_icache - even ones which
4981 * have a transaction open against a different journal.
4983 * Is this cheating? Not really. Sure, we haven't written the
4984 * inode out, but prune_icache isn't a user-visible syncing function.
4985 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4986 * we start and wait on commits.
4988 * Is this efficient/effective? Well, we're being nice to the system
4989 * by cleaning up our inodes proactively so they can be reaped
4990 * without I/O. But we are potentially leaving up to five seconds'
4991 * worth of inodes floating about which prune_icache wants us to
4992 * write out. One way to fix that would be to get prune_icache()
4993 * to do a write_super() to free up some memory. It has the desired
4996 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
4998 struct ext4_iloc iloc
;
4999 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5000 static unsigned int mnt_count
;
5004 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5005 if (ext4_handle_valid(handle
) &&
5006 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5007 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
5009 * We need extra buffer credits since we may write into EA block
5010 * with this same handle. If journal_extend fails, then it will
5011 * only result in a minor loss of functionality for that inode.
5012 * If this is felt to be critical, then e2fsck should be run to
5013 * force a large enough s_min_extra_isize.
5015 if ((jbd2_journal_extend(handle
,
5016 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5017 ret
= ext4_expand_extra_isize(inode
,
5018 sbi
->s_want_extra_isize
,
5021 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
5023 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5024 ext4_warning(inode
->i_sb
, __func__
,
5025 "Unable to expand inode %lu. Delete"
5026 " some EAs or run e2fsck.",
5029 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5035 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5040 * ext4_dirty_inode() is called from __mark_inode_dirty()
5042 * We're really interested in the case where a file is being extended.
5043 * i_size has been changed by generic_commit_write() and we thus need
5044 * to include the updated inode in the current transaction.
5046 * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
5047 * are allocated to the file.
5049 * If the inode is marked synchronous, we don't honour that here - doing
5050 * so would cause a commit on atime updates, which we don't bother doing.
5051 * We handle synchronous inodes at the highest possible level.
5053 void ext4_dirty_inode(struct inode
*inode
)
5055 handle_t
*current_handle
= ext4_journal_current_handle();
5058 if (!ext4_handle_valid(current_handle
)) {
5059 ext4_mark_inode_dirty(current_handle
, inode
);
5063 handle
= ext4_journal_start(inode
, 2);
5066 if (current_handle
&&
5067 current_handle
->h_transaction
!= handle
->h_transaction
) {
5068 /* This task has a transaction open against a different fs */
5069 printk(KERN_EMERG
"%s: transactions do not match!\n",
5072 jbd_debug(5, "marking dirty. outer handle=%p\n",
5074 ext4_mark_inode_dirty(handle
, inode
);
5076 ext4_journal_stop(handle
);
5083 * Bind an inode's backing buffer_head into this transaction, to prevent
5084 * it from being flushed to disk early. Unlike
5085 * ext4_reserve_inode_write, this leaves behind no bh reference and
5086 * returns no iloc structure, so the caller needs to repeat the iloc
5087 * lookup to mark the inode dirty later.
5089 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5091 struct ext4_iloc iloc
;
5095 err
= ext4_get_inode_loc(inode
, &iloc
);
5097 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5098 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5100 err
= ext4_handle_dirty_metadata(handle
,
5106 ext4_std_error(inode
->i_sb
, err
);
5111 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5118 * We have to be very careful here: changing a data block's
5119 * journaling status dynamically is dangerous. If we write a
5120 * data block to the journal, change the status and then delete
5121 * that block, we risk forgetting to revoke the old log record
5122 * from the journal and so a subsequent replay can corrupt data.
5123 * So, first we make sure that the journal is empty and that
5124 * nobody is changing anything.
5127 journal
= EXT4_JOURNAL(inode
);
5130 if (is_journal_aborted(journal
))
5133 jbd2_journal_lock_updates(journal
);
5134 jbd2_journal_flush(journal
);
5137 * OK, there are no updates running now, and all cached data is
5138 * synced to disk. We are now in a completely consistent state
5139 * which doesn't have anything in the journal, and we know that
5140 * no filesystem updates are running, so it is safe to modify
5141 * the inode's in-core data-journaling state flag now.
5145 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
5147 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
5148 ext4_set_aops(inode
);
5150 jbd2_journal_unlock_updates(journal
);
5152 /* Finally we can mark the inode as dirty. */
5154 handle
= ext4_journal_start(inode
, 1);
5156 return PTR_ERR(handle
);
5158 err
= ext4_mark_inode_dirty(handle
, inode
);
5159 ext4_handle_sync(handle
);
5160 ext4_journal_stop(handle
);
5161 ext4_std_error(inode
->i_sb
, err
);
5166 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5168 return !buffer_mapped(bh
);
5171 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5173 struct page
*page
= vmf
->page
;
5178 struct file
*file
= vma
->vm_file
;
5179 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5180 struct address_space
*mapping
= inode
->i_mapping
;
5183 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5184 * get i_mutex because we are already holding mmap_sem.
5186 down_read(&inode
->i_alloc_sem
);
5187 size
= i_size_read(inode
);
5188 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5189 || !PageUptodate(page
)) {
5190 /* page got truncated from under us? */
5194 if (PageMappedToDisk(page
))
5197 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5198 len
= size
& ~PAGE_CACHE_MASK
;
5200 len
= PAGE_CACHE_SIZE
;
5202 if (page_has_buffers(page
)) {
5203 /* return if we have all the buffers mapped */
5204 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5209 * OK, we need to fill the hole... Do write_begin write_end
5210 * to do block allocation/reservation.We are not holding
5211 * inode.i__mutex here. That allow * parallel write_begin,
5212 * write_end call. lock_page prevent this from happening
5213 * on the same page though
5215 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5216 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5219 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5220 len
, len
, page
, fsdata
);
5226 ret
= VM_FAULT_SIGBUS
;
5227 up_read(&inode
->i_alloc_sem
);