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 <linux/workqueue.h>
41 #include <linux/kernel.h>
42 #include <linux/slab.h>
44 #include "ext4_jbd2.h"
47 #include "ext4_extents.h"
49 #include <trace/events/ext4.h>
51 #define MPAGE_DA_EXTENT_TAIL 0x01
53 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
56 return jbd2_journal_begin_ordered_truncate(
57 EXT4_SB(inode
->i_sb
)->s_journal
,
58 &EXT4_I(inode
)->jinode
,
62 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
65 * Test whether an inode is a fast symlink.
67 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
69 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
70 (inode
->i_sb
->s_blocksize
>> 9) : 0;
72 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
76 * Work out how many blocks we need to proceed with the next chunk of a
77 * truncate transaction.
79 static unsigned long blocks_for_truncate(struct inode
*inode
)
83 needed
= inode
->i_blocks
>> (inode
->i_sb
->s_blocksize_bits
- 9);
85 /* Give ourselves just enough room to cope with inodes in which
86 * i_blocks is corrupt: we've seen disk corruptions in the past
87 * which resulted in random data in an inode which looked enough
88 * like a regular file for ext4 to try to delete it. Things
89 * will go a bit crazy if that happens, but at least we should
90 * try not to panic the whole kernel. */
94 /* But we need to bound the transaction so we don't overflow the
96 if (needed
> EXT4_MAX_TRANS_DATA
)
97 needed
= EXT4_MAX_TRANS_DATA
;
99 return EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + needed
;
103 * Truncate transactions can be complex and absolutely huge. So we need to
104 * be able to restart the transaction at a conventient checkpoint to make
105 * sure we don't overflow the journal.
107 * start_transaction gets us a new handle for a truncate transaction,
108 * and extend_transaction tries to extend the existing one a bit. If
109 * extend fails, we need to propagate the failure up and restart the
110 * transaction in the top-level truncate loop. --sct
112 static handle_t
*start_transaction(struct inode
*inode
)
116 result
= ext4_journal_start(inode
, blocks_for_truncate(inode
));
120 ext4_std_error(inode
->i_sb
, PTR_ERR(result
));
125 * Try to extend this transaction for the purposes of truncation.
127 * Returns 0 if we managed to create more room. If we can't create more
128 * room, and the transaction must be restarted we return 1.
130 static int try_to_extend_transaction(handle_t
*handle
, struct inode
*inode
)
132 if (!ext4_handle_valid(handle
))
134 if (ext4_handle_has_enough_credits(handle
, EXT4_RESERVE_TRANS_BLOCKS
+1))
136 if (!ext4_journal_extend(handle
, blocks_for_truncate(inode
)))
142 * Restart the transaction associated with *handle. This does a commit,
143 * so before we call here everything must be consistently dirtied against
146 int ext4_truncate_restart_trans(handle_t
*handle
, struct inode
*inode
,
152 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
153 * moment, get_block can be called only for blocks inside i_size since
154 * page cache has been already dropped and writes are blocked by
155 * i_mutex. So we can safely drop the i_data_sem here.
157 BUG_ON(EXT4_JOURNAL(inode
) == NULL
);
158 jbd_debug(2, "restarting handle %p\n", handle
);
159 up_write(&EXT4_I(inode
)->i_data_sem
);
160 ret
= ext4_journal_restart(handle
, blocks_for_truncate(inode
));
161 down_write(&EXT4_I(inode
)->i_data_sem
);
162 ext4_discard_preallocations(inode
);
168 * Called at the last iput() if i_nlink is zero.
170 void ext4_evict_inode(struct inode
*inode
)
175 if (inode
->i_nlink
) {
176 truncate_inode_pages(&inode
->i_data
, 0);
180 if (!is_bad_inode(inode
))
181 dquot_initialize(inode
);
183 if (ext4_should_order_data(inode
))
184 ext4_begin_ordered_truncate(inode
, 0);
185 truncate_inode_pages(&inode
->i_data
, 0);
187 if (is_bad_inode(inode
))
190 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
191 if (IS_ERR(handle
)) {
192 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
194 * If we're going to skip the normal cleanup, we still need to
195 * make sure that the in-core orphan linked list is properly
198 ext4_orphan_del(NULL
, inode
);
203 ext4_handle_sync(handle
);
205 err
= ext4_mark_inode_dirty(handle
, inode
);
207 ext4_warning(inode
->i_sb
,
208 "couldn't mark inode dirty (err %d)", err
);
212 ext4_truncate(inode
);
215 * ext4_ext_truncate() doesn't reserve any slop when it
216 * restarts journal transactions; therefore there may not be
217 * enough credits left in the handle to remove the inode from
218 * the orphan list and set the dtime field.
220 if (!ext4_handle_has_enough_credits(handle
, 3)) {
221 err
= ext4_journal_extend(handle
, 3);
223 err
= ext4_journal_restart(handle
, 3);
225 ext4_warning(inode
->i_sb
,
226 "couldn't extend journal (err %d)", err
);
228 ext4_journal_stop(handle
);
229 ext4_orphan_del(NULL
, inode
);
235 * Kill off the orphan record which ext4_truncate created.
236 * AKPM: I think this can be inside the above `if'.
237 * Note that ext4_orphan_del() has to be able to cope with the
238 * deletion of a non-existent orphan - this is because we don't
239 * know if ext4_truncate() actually created an orphan record.
240 * (Well, we could do this if we need to, but heck - it works)
242 ext4_orphan_del(handle
, inode
);
243 EXT4_I(inode
)->i_dtime
= get_seconds();
246 * One subtle ordering requirement: if anything has gone wrong
247 * (transaction abort, IO errors, whatever), then we can still
248 * do these next steps (the fs will already have been marked as
249 * having errors), but we can't free the inode if the mark_dirty
252 if (ext4_mark_inode_dirty(handle
, inode
))
253 /* If that failed, just do the required in-core inode clear. */
254 ext4_clear_inode(inode
);
256 ext4_free_inode(handle
, inode
);
257 ext4_journal_stop(handle
);
260 ext4_clear_inode(inode
); /* We must guarantee clearing of inode... */
266 struct buffer_head
*bh
;
269 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
271 p
->key
= *(p
->p
= v
);
276 * ext4_block_to_path - parse the block number into array of offsets
277 * @inode: inode in question (we are only interested in its superblock)
278 * @i_block: block number to be parsed
279 * @offsets: array to store the offsets in
280 * @boundary: set this non-zero if the referred-to block is likely to be
281 * followed (on disk) by an indirect block.
283 * To store the locations of file's data ext4 uses a data structure common
284 * for UNIX filesystems - tree of pointers anchored in the inode, with
285 * data blocks at leaves and indirect blocks in intermediate nodes.
286 * This function translates the block number into path in that tree -
287 * return value is the path length and @offsets[n] is the offset of
288 * pointer to (n+1)th node in the nth one. If @block is out of range
289 * (negative or too large) warning is printed and zero returned.
291 * Note: function doesn't find node addresses, so no IO is needed. All
292 * we need to know is the capacity of indirect blocks (taken from the
297 * Portability note: the last comparison (check that we fit into triple
298 * indirect block) is spelled differently, because otherwise on an
299 * architecture with 32-bit longs and 8Kb pages we might get into trouble
300 * if our filesystem had 8Kb blocks. We might use long long, but that would
301 * kill us on x86. Oh, well, at least the sign propagation does not matter -
302 * i_block would have to be negative in the very beginning, so we would not
306 static int ext4_block_to_path(struct inode
*inode
,
308 ext4_lblk_t offsets
[4], int *boundary
)
310 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
311 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
312 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
313 indirect_blocks
= ptrs
,
314 double_blocks
= (1 << (ptrs_bits
* 2));
318 if (i_block
< direct_blocks
) {
319 offsets
[n
++] = i_block
;
320 final
= direct_blocks
;
321 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
322 offsets
[n
++] = EXT4_IND_BLOCK
;
323 offsets
[n
++] = i_block
;
325 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
326 offsets
[n
++] = EXT4_DIND_BLOCK
;
327 offsets
[n
++] = i_block
>> ptrs_bits
;
328 offsets
[n
++] = i_block
& (ptrs
- 1);
330 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
331 offsets
[n
++] = EXT4_TIND_BLOCK
;
332 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
333 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
334 offsets
[n
++] = i_block
& (ptrs
- 1);
337 ext4_warning(inode
->i_sb
, "block %lu > max in inode %lu",
338 i_block
+ direct_blocks
+
339 indirect_blocks
+ double_blocks
, inode
->i_ino
);
342 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
346 static int __ext4_check_blockref(const char *function
, unsigned int line
,
348 __le32
*p
, unsigned int max
)
350 struct ext4_super_block
*es
= EXT4_SB(inode
->i_sb
)->s_es
;
354 while (bref
< p
+max
) {
355 blk
= le32_to_cpu(*bref
++);
357 unlikely(!ext4_data_block_valid(EXT4_SB(inode
->i_sb
),
359 es
->s_last_error_block
= cpu_to_le64(blk
);
360 ext4_error_inode(inode
, function
, line
, blk
,
369 #define ext4_check_indirect_blockref(inode, bh) \
370 __ext4_check_blockref(__func__, __LINE__, inode, \
371 (__le32 *)(bh)->b_data, \
372 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
374 #define ext4_check_inode_blockref(inode) \
375 __ext4_check_blockref(__func__, __LINE__, inode, \
376 EXT4_I(inode)->i_data, \
380 * ext4_get_branch - read the chain of indirect blocks leading to data
381 * @inode: inode in question
382 * @depth: depth of the chain (1 - direct pointer, etc.)
383 * @offsets: offsets of pointers in inode/indirect blocks
384 * @chain: place to store the result
385 * @err: here we store the error value
387 * Function fills the array of triples <key, p, bh> and returns %NULL
388 * if everything went OK or the pointer to the last filled triple
389 * (incomplete one) otherwise. Upon the return chain[i].key contains
390 * the number of (i+1)-th block in the chain (as it is stored in memory,
391 * i.e. little-endian 32-bit), chain[i].p contains the address of that
392 * number (it points into struct inode for i==0 and into the bh->b_data
393 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
394 * block for i>0 and NULL for i==0. In other words, it holds the block
395 * numbers of the chain, addresses they were taken from (and where we can
396 * verify that chain did not change) and buffer_heads hosting these
399 * Function stops when it stumbles upon zero pointer (absent block)
400 * (pointer to last triple returned, *@err == 0)
401 * or when it gets an IO error reading an indirect block
402 * (ditto, *@err == -EIO)
403 * or when it reads all @depth-1 indirect blocks successfully and finds
404 * the whole chain, all way to the data (returns %NULL, *err == 0).
406 * Need to be called with
407 * down_read(&EXT4_I(inode)->i_data_sem)
409 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
410 ext4_lblk_t
*offsets
,
411 Indirect chain
[4], int *err
)
413 struct super_block
*sb
= inode
->i_sb
;
415 struct buffer_head
*bh
;
418 /* i_data is not going away, no lock needed */
419 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
423 bh
= sb_getblk(sb
, le32_to_cpu(p
->key
));
427 if (!bh_uptodate_or_lock(bh
)) {
428 if (bh_submit_read(bh
) < 0) {
432 /* validate block references */
433 if (ext4_check_indirect_blockref(inode
, bh
)) {
439 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
453 * ext4_find_near - find a place for allocation with sufficient locality
455 * @ind: descriptor of indirect block.
457 * This function returns the preferred place for block allocation.
458 * It is used when heuristic for sequential allocation fails.
460 * + if there is a block to the left of our position - allocate near it.
461 * + if pointer will live in indirect block - allocate near that block.
462 * + if pointer will live in inode - allocate in the same
465 * In the latter case we colour the starting block by the callers PID to
466 * prevent it from clashing with concurrent allocations for a different inode
467 * in the same block group. The PID is used here so that functionally related
468 * files will be close-by on-disk.
470 * Caller must make sure that @ind is valid and will stay that way.
472 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
474 struct ext4_inode_info
*ei
= EXT4_I(inode
);
475 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
477 ext4_fsblk_t bg_start
;
478 ext4_fsblk_t last_block
;
479 ext4_grpblk_t colour
;
480 ext4_group_t block_group
;
481 int flex_size
= ext4_flex_bg_size(EXT4_SB(inode
->i_sb
));
483 /* Try to find previous block */
484 for (p
= ind
->p
- 1; p
>= start
; p
--) {
486 return le32_to_cpu(*p
);
489 /* No such thing, so let's try location of indirect block */
491 return ind
->bh
->b_blocknr
;
494 * It is going to be referred to from the inode itself? OK, just put it
495 * into the same cylinder group then.
497 block_group
= ei
->i_block_group
;
498 if (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) {
499 block_group
&= ~(flex_size
-1);
500 if (S_ISREG(inode
->i_mode
))
503 bg_start
= ext4_group_first_block_no(inode
->i_sb
, block_group
);
504 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
507 * If we are doing delayed allocation, we don't need take
508 * colour into account.
510 if (test_opt(inode
->i_sb
, DELALLOC
))
513 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
514 colour
= (current
->pid
% 16) *
515 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
517 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
518 return bg_start
+ colour
;
522 * ext4_find_goal - find a preferred place for allocation.
524 * @block: block we want
525 * @partial: pointer to the last triple within a chain
527 * Normally this function find the preferred place for block allocation,
529 * Because this is only used for non-extent files, we limit the block nr
532 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
538 * XXX need to get goal block from mballoc's data structures
541 goal
= ext4_find_near(inode
, partial
);
542 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
547 * ext4_blks_to_allocate: Look up the block map and count the number
548 * of direct blocks need to be allocated for the given branch.
550 * @branch: chain of indirect blocks
551 * @k: number of blocks need for indirect blocks
552 * @blks: number of data blocks to be mapped.
553 * @blocks_to_boundary: the offset in the indirect block
555 * return the total number of blocks to be allocate, including the
556 * direct and indirect blocks.
558 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned int blks
,
559 int blocks_to_boundary
)
561 unsigned int count
= 0;
564 * Simple case, [t,d]Indirect block(s) has not allocated yet
565 * then it's clear blocks on that path have not allocated
568 /* right now we don't handle cross boundary allocation */
569 if (blks
< blocks_to_boundary
+ 1)
572 count
+= blocks_to_boundary
+ 1;
577 while (count
< blks
&& count
<= blocks_to_boundary
&&
578 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
585 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
586 * @indirect_blks: the number of blocks need to allocate for indirect
589 * @new_blocks: on return it will store the new block numbers for
590 * the indirect blocks(if needed) and the first direct block,
591 * @blks: on return it will store the total number of allocated
594 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
595 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
596 int indirect_blks
, int blks
,
597 ext4_fsblk_t new_blocks
[4], int *err
)
599 struct ext4_allocation_request ar
;
601 unsigned long count
= 0, blk_allocated
= 0;
603 ext4_fsblk_t current_block
= 0;
607 * Here we try to allocate the requested multiple blocks at once,
608 * on a best-effort basis.
609 * To build a branch, we should allocate blocks for
610 * the indirect blocks(if not allocated yet), and at least
611 * the first direct block of this branch. That's the
612 * minimum number of blocks need to allocate(required)
614 /* first we try to allocate the indirect blocks */
615 target
= indirect_blks
;
618 /* allocating blocks for indirect blocks and direct blocks */
619 current_block
= ext4_new_meta_blocks(handle
, inode
,
624 if (unlikely(current_block
+ count
> EXT4_MAX_BLOCK_FILE_PHYS
)) {
625 EXT4_ERROR_INODE(inode
,
626 "current_block %llu + count %lu > %d!",
627 current_block
, count
,
628 EXT4_MAX_BLOCK_FILE_PHYS
);
634 /* allocate blocks for indirect blocks */
635 while (index
< indirect_blks
&& count
) {
636 new_blocks
[index
++] = current_block
++;
641 * save the new block number
642 * for the first direct block
644 new_blocks
[index
] = current_block
;
645 printk(KERN_INFO
"%s returned more blocks than "
646 "requested\n", __func__
);
652 target
= blks
- count
;
653 blk_allocated
= count
;
656 /* Now allocate data blocks */
657 memset(&ar
, 0, sizeof(ar
));
662 if (S_ISREG(inode
->i_mode
))
663 /* enable in-core preallocation only for regular files */
664 ar
.flags
= EXT4_MB_HINT_DATA
;
666 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
667 if (unlikely(current_block
+ ar
.len
> EXT4_MAX_BLOCK_FILE_PHYS
)) {
668 EXT4_ERROR_INODE(inode
,
669 "current_block %llu + ar.len %d > %d!",
670 current_block
, ar
.len
,
671 EXT4_MAX_BLOCK_FILE_PHYS
);
676 if (*err
&& (target
== blks
)) {
678 * if the allocation failed and we didn't allocate
684 if (target
== blks
) {
686 * save the new block number
687 * for the first direct block
689 new_blocks
[index
] = current_block
;
691 blk_allocated
+= ar
.len
;
694 /* total number of blocks allocated for direct blocks */
699 for (i
= 0; i
< index
; i
++)
700 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1, 0);
705 * ext4_alloc_branch - allocate and set up a chain of blocks.
707 * @indirect_blks: number of allocated indirect blocks
708 * @blks: number of allocated direct blocks
709 * @offsets: offsets (in the blocks) to store the pointers to next.
710 * @branch: place to store the chain in.
712 * This function allocates blocks, zeroes out all but the last one,
713 * links them into chain and (if we are synchronous) writes them to disk.
714 * In other words, it prepares a branch that can be spliced onto the
715 * inode. It stores the information about that chain in the branch[], in
716 * the same format as ext4_get_branch() would do. We are calling it after
717 * we had read the existing part of chain and partial points to the last
718 * triple of that (one with zero ->key). Upon the exit we have the same
719 * picture as after the successful ext4_get_block(), except that in one
720 * place chain is disconnected - *branch->p is still zero (we did not
721 * set the last link), but branch->key contains the number that should
722 * be placed into *branch->p to fill that gap.
724 * If allocation fails we free all blocks we've allocated (and forget
725 * their buffer_heads) and return the error value the from failed
726 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
727 * as described above and return 0.
729 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
730 ext4_lblk_t iblock
, int indirect_blks
,
731 int *blks
, ext4_fsblk_t goal
,
732 ext4_lblk_t
*offsets
, Indirect
*branch
)
734 int blocksize
= inode
->i_sb
->s_blocksize
;
737 struct buffer_head
*bh
;
739 ext4_fsblk_t new_blocks
[4];
740 ext4_fsblk_t current_block
;
742 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
743 *blks
, new_blocks
, &err
);
747 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
749 * metadata blocks and data blocks are allocated.
751 for (n
= 1; n
<= indirect_blks
; n
++) {
753 * Get buffer_head for parent block, zero it out
754 * and set the pointer to new one, then send
757 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
760 BUFFER_TRACE(bh
, "call get_create_access");
761 err
= ext4_journal_get_create_access(handle
, bh
);
763 /* Don't brelse(bh) here; it's done in
764 * ext4_journal_forget() below */
769 memset(bh
->b_data
, 0, blocksize
);
770 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
771 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
772 *branch
[n
].p
= branch
[n
].key
;
773 if (n
== indirect_blks
) {
774 current_block
= new_blocks
[n
];
776 * End of chain, update the last new metablock of
777 * the chain to point to the new allocated
778 * data blocks numbers
780 for (i
= 1; i
< num
; i
++)
781 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
783 BUFFER_TRACE(bh
, "marking uptodate");
784 set_buffer_uptodate(bh
);
787 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
788 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
795 /* Allocation failed, free what we already allocated */
796 ext4_free_blocks(handle
, inode
, 0, new_blocks
[0], 1, 0);
797 for (i
= 1; i
<= n
; i
++) {
799 * branch[i].bh is newly allocated, so there is no
800 * need to revoke the block, which is why we don't
801 * need to set EXT4_FREE_BLOCKS_METADATA.
803 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1,
804 EXT4_FREE_BLOCKS_FORGET
);
806 for (i
= n
+1; i
< indirect_blks
; i
++)
807 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1, 0);
809 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], num
, 0);
815 * ext4_splice_branch - splice the allocated branch onto inode.
817 * @block: (logical) number of block we are adding
818 * @chain: chain of indirect blocks (with a missing link - see
820 * @where: location of missing link
821 * @num: number of indirect blocks we are adding
822 * @blks: number of direct blocks we are adding
824 * This function fills the missing link and does all housekeeping needed in
825 * inode (->i_blocks, etc.). In case of success we end up with the full
826 * chain to new block and return 0.
828 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
829 ext4_lblk_t block
, Indirect
*where
, int num
,
834 ext4_fsblk_t current_block
;
837 * If we're splicing into a [td]indirect block (as opposed to the
838 * inode) then we need to get write access to the [td]indirect block
842 BUFFER_TRACE(where
->bh
, "get_write_access");
843 err
= ext4_journal_get_write_access(handle
, where
->bh
);
849 *where
->p
= where
->key
;
852 * Update the host buffer_head or inode to point to more just allocated
853 * direct blocks blocks
855 if (num
== 0 && blks
> 1) {
856 current_block
= le32_to_cpu(where
->key
) + 1;
857 for (i
= 1; i
< blks
; i
++)
858 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
861 /* We are done with atomic stuff, now do the rest of housekeeping */
862 /* had we spliced it onto indirect block? */
865 * If we spliced it onto an indirect block, we haven't
866 * altered the inode. Note however that if it is being spliced
867 * onto an indirect block at the very end of the file (the
868 * file is growing) then we *will* alter the inode to reflect
869 * the new i_size. But that is not done here - it is done in
870 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
872 jbd_debug(5, "splicing indirect only\n");
873 BUFFER_TRACE(where
->bh
, "call ext4_handle_dirty_metadata");
874 err
= ext4_handle_dirty_metadata(handle
, inode
, where
->bh
);
879 * OK, we spliced it into the inode itself on a direct block.
881 ext4_mark_inode_dirty(handle
, inode
);
882 jbd_debug(5, "splicing direct\n");
887 for (i
= 1; i
<= num
; i
++) {
889 * branch[i].bh is newly allocated, so there is no
890 * need to revoke the block, which is why we don't
891 * need to set EXT4_FREE_BLOCKS_METADATA.
893 ext4_free_blocks(handle
, inode
, where
[i
].bh
, 0, 1,
894 EXT4_FREE_BLOCKS_FORGET
);
896 ext4_free_blocks(handle
, inode
, 0, le32_to_cpu(where
[num
].key
),
903 * The ext4_ind_map_blocks() function handles non-extents inodes
904 * (i.e., using the traditional indirect/double-indirect i_blocks
905 * scheme) for ext4_map_blocks().
907 * Allocation strategy is simple: if we have to allocate something, we will
908 * have to go the whole way to leaf. So let's do it before attaching anything
909 * to tree, set linkage between the newborn blocks, write them if sync is
910 * required, recheck the path, free and repeat if check fails, otherwise
911 * set the last missing link (that will protect us from any truncate-generated
912 * removals - all blocks on the path are immune now) and possibly force the
913 * write on the parent block.
914 * That has a nice additional property: no special recovery from the failed
915 * allocations is needed - we simply release blocks and do not touch anything
916 * reachable from inode.
918 * `handle' can be NULL if create == 0.
920 * return > 0, # of blocks mapped or allocated.
921 * return = 0, if plain lookup failed.
922 * return < 0, error case.
924 * The ext4_ind_get_blocks() function should be called with
925 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
926 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
927 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
930 static int ext4_ind_map_blocks(handle_t
*handle
, struct inode
*inode
,
931 struct ext4_map_blocks
*map
,
935 ext4_lblk_t offsets
[4];
940 int blocks_to_boundary
= 0;
943 ext4_fsblk_t first_block
= 0;
945 J_ASSERT(!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)));
946 J_ASSERT(handle
!= NULL
|| (flags
& EXT4_GET_BLOCKS_CREATE
) == 0);
947 depth
= ext4_block_to_path(inode
, map
->m_lblk
, offsets
,
948 &blocks_to_boundary
);
953 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
955 /* Simplest case - block found, no allocation needed */
957 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
960 while (count
< map
->m_len
&& count
<= blocks_to_boundary
) {
963 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
965 if (blk
== first_block
+ count
)
973 /* Next simple case - plain lookup or failed read of indirect block */
974 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0 || err
== -EIO
)
978 * Okay, we need to do block allocation.
980 goal
= ext4_find_goal(inode
, map
->m_lblk
, partial
);
982 /* the number of blocks need to allocate for [d,t]indirect blocks */
983 indirect_blks
= (chain
+ depth
) - partial
- 1;
986 * Next look up the indirect map to count the totoal number of
987 * direct blocks to allocate for this branch.
989 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
990 map
->m_len
, blocks_to_boundary
);
992 * Block out ext4_truncate while we alter the tree
994 err
= ext4_alloc_branch(handle
, inode
, map
->m_lblk
, indirect_blks
,
996 offsets
+ (partial
- chain
), partial
);
999 * The ext4_splice_branch call will free and forget any buffers
1000 * on the new chain if there is a failure, but that risks using
1001 * up transaction credits, especially for bitmaps where the
1002 * credits cannot be returned. Can we handle this somehow? We
1003 * may need to return -EAGAIN upwards in the worst case. --sct
1006 err
= ext4_splice_branch(handle
, inode
, map
->m_lblk
,
1007 partial
, indirect_blks
, count
);
1011 map
->m_flags
|= EXT4_MAP_NEW
;
1013 ext4_update_inode_fsync_trans(handle
, inode
, 1);
1015 map
->m_flags
|= EXT4_MAP_MAPPED
;
1016 map
->m_pblk
= le32_to_cpu(chain
[depth
-1].key
);
1018 if (count
> blocks_to_boundary
)
1019 map
->m_flags
|= EXT4_MAP_BOUNDARY
;
1021 /* Clean up and exit */
1022 partial
= chain
+ depth
- 1; /* the whole chain */
1024 while (partial
> chain
) {
1025 BUFFER_TRACE(partial
->bh
, "call brelse");
1026 brelse(partial
->bh
);
1034 qsize_t
*ext4_get_reserved_space(struct inode
*inode
)
1036 return &EXT4_I(inode
)->i_reserved_quota
;
1041 * Calculate the number of metadata blocks need to reserve
1042 * to allocate a new block at @lblocks for non extent file based file
1044 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
,
1047 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1048 sector_t dind_mask
= ~((sector_t
)EXT4_ADDR_PER_BLOCK(inode
->i_sb
) - 1);
1051 if (lblock
< EXT4_NDIR_BLOCKS
)
1054 lblock
-= EXT4_NDIR_BLOCKS
;
1056 if (ei
->i_da_metadata_calc_len
&&
1057 (lblock
& dind_mask
) == ei
->i_da_metadata_calc_last_lblock
) {
1058 ei
->i_da_metadata_calc_len
++;
1061 ei
->i_da_metadata_calc_last_lblock
= lblock
& dind_mask
;
1062 ei
->i_da_metadata_calc_len
= 1;
1063 blk_bits
= order_base_2(lblock
);
1064 return (blk_bits
/ EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
)) + 1;
1068 * Calculate the number of metadata blocks need to reserve
1069 * to allocate a block located at @lblock
1071 static int ext4_calc_metadata_amount(struct inode
*inode
, sector_t lblock
)
1073 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
1074 return ext4_ext_calc_metadata_amount(inode
, lblock
);
1076 return ext4_indirect_calc_metadata_amount(inode
, lblock
);
1080 * Called with i_data_sem down, which is important since we can call
1081 * ext4_discard_preallocations() from here.
1083 void ext4_da_update_reserve_space(struct inode
*inode
,
1084 int used
, int quota_claim
)
1086 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1087 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1089 spin_lock(&ei
->i_block_reservation_lock
);
1090 trace_ext4_da_update_reserve_space(inode
, used
);
1091 if (unlikely(used
> ei
->i_reserved_data_blocks
)) {
1092 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "%s: ino %lu, used %d "
1093 "with only %d reserved data blocks\n",
1094 __func__
, inode
->i_ino
, used
,
1095 ei
->i_reserved_data_blocks
);
1097 used
= ei
->i_reserved_data_blocks
;
1100 /* Update per-inode reservations */
1101 ei
->i_reserved_data_blocks
-= used
;
1102 ei
->i_reserved_meta_blocks
-= ei
->i_allocated_meta_blocks
;
1103 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
1104 used
+ ei
->i_allocated_meta_blocks
);
1105 ei
->i_allocated_meta_blocks
= 0;
1107 if (ei
->i_reserved_data_blocks
== 0) {
1109 * We can release all of the reserved metadata blocks
1110 * only when we have written all of the delayed
1111 * allocation blocks.
1113 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
1114 ei
->i_reserved_meta_blocks
);
1115 ei
->i_reserved_meta_blocks
= 0;
1116 ei
->i_da_metadata_calc_len
= 0;
1118 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1120 /* Update quota subsystem for data blocks */
1122 dquot_claim_block(inode
, used
);
1125 * We did fallocate with an offset that is already delayed
1126 * allocated. So on delayed allocated writeback we should
1127 * not re-claim the quota for fallocated blocks.
1129 dquot_release_reservation_block(inode
, used
);
1133 * If we have done all the pending block allocations and if
1134 * there aren't any writers on the inode, we can discard the
1135 * inode's preallocations.
1137 if ((ei
->i_reserved_data_blocks
== 0) &&
1138 (atomic_read(&inode
->i_writecount
) == 0))
1139 ext4_discard_preallocations(inode
);
1142 static int __check_block_validity(struct inode
*inode
, const char *func
,
1144 struct ext4_map_blocks
*map
)
1146 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), map
->m_pblk
,
1148 ext4_error_inode(inode
, func
, line
, map
->m_pblk
,
1149 "lblock %lu mapped to illegal pblock "
1150 "(length %d)", (unsigned long) map
->m_lblk
,
1157 #define check_block_validity(inode, map) \
1158 __check_block_validity((inode), __func__, __LINE__, (map))
1161 * Return the number of contiguous dirty pages in a given inode
1162 * starting at page frame idx.
1164 static pgoff_t
ext4_num_dirty_pages(struct inode
*inode
, pgoff_t idx
,
1165 unsigned int max_pages
)
1167 struct address_space
*mapping
= inode
->i_mapping
;
1169 struct pagevec pvec
;
1171 int i
, nr_pages
, done
= 0;
1175 pagevec_init(&pvec
, 0);
1178 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1179 PAGECACHE_TAG_DIRTY
,
1180 (pgoff_t
)PAGEVEC_SIZE
);
1183 for (i
= 0; i
< nr_pages
; i
++) {
1184 struct page
*page
= pvec
.pages
[i
];
1185 struct buffer_head
*bh
, *head
;
1188 if (unlikely(page
->mapping
!= mapping
) ||
1190 PageWriteback(page
) ||
1191 page
->index
!= idx
) {
1196 if (page_has_buffers(page
)) {
1197 bh
= head
= page_buffers(page
);
1199 if (!buffer_delay(bh
) &&
1200 !buffer_unwritten(bh
))
1202 bh
= bh
->b_this_page
;
1203 } while (!done
&& (bh
!= head
));
1210 if (num
>= max_pages
)
1213 pagevec_release(&pvec
);
1219 * The ext4_map_blocks() function tries to look up the requested blocks,
1220 * and returns if the blocks are already mapped.
1222 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1223 * and store the allocated blocks in the result buffer head and mark it
1226 * If file type is extents based, it will call ext4_ext_map_blocks(),
1227 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
1230 * On success, it returns the number of blocks being mapped or allocate.
1231 * if create==0 and the blocks are pre-allocated and uninitialized block,
1232 * the result buffer head is unmapped. If the create ==1, it will make sure
1233 * the buffer head is mapped.
1235 * It returns 0 if plain look up failed (blocks have not been allocated), in
1236 * that casem, buffer head is unmapped
1238 * It returns the error in case of allocation failure.
1240 int ext4_map_blocks(handle_t
*handle
, struct inode
*inode
,
1241 struct ext4_map_blocks
*map
, int flags
)
1246 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
1247 "logical block %lu\n", inode
->i_ino
, flags
, map
->m_len
,
1248 (unsigned long) map
->m_lblk
);
1250 * Try to see if we can get the block without requesting a new
1251 * file system block.
1253 down_read((&EXT4_I(inode
)->i_data_sem
));
1254 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
1255 retval
= ext4_ext_map_blocks(handle
, inode
, map
, 0);
1257 retval
= ext4_ind_map_blocks(handle
, inode
, map
, 0);
1259 up_read((&EXT4_I(inode
)->i_data_sem
));
1261 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
) {
1262 int ret
= check_block_validity(inode
, map
);
1267 /* If it is only a block(s) look up */
1268 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
1272 * Returns if the blocks have already allocated
1274 * Note that if blocks have been preallocated
1275 * ext4_ext_get_block() returns th create = 0
1276 * with buffer head unmapped.
1278 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
)
1282 * When we call get_blocks without the create flag, the
1283 * BH_Unwritten flag could have gotten set if the blocks
1284 * requested were part of a uninitialized extent. We need to
1285 * clear this flag now that we are committed to convert all or
1286 * part of the uninitialized extent to be an initialized
1287 * extent. This is because we need to avoid the combination
1288 * of BH_Unwritten and BH_Mapped flags being simultaneously
1289 * set on the buffer_head.
1291 map
->m_flags
&= ~EXT4_MAP_UNWRITTEN
;
1294 * New blocks allocate and/or writing to uninitialized extent
1295 * will possibly result in updating i_data, so we take
1296 * the write lock of i_data_sem, and call get_blocks()
1297 * with create == 1 flag.
1299 down_write((&EXT4_I(inode
)->i_data_sem
));
1302 * if the caller is from delayed allocation writeout path
1303 * we have already reserved fs blocks for allocation
1304 * let the underlying get_block() function know to
1305 * avoid double accounting
1307 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1308 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1310 * We need to check for EXT4 here because migrate
1311 * could have changed the inode type in between
1313 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
1314 retval
= ext4_ext_map_blocks(handle
, inode
, map
, flags
);
1316 retval
= ext4_ind_map_blocks(handle
, inode
, map
, flags
);
1318 if (retval
> 0 && map
->m_flags
& EXT4_MAP_NEW
) {
1320 * We allocated new blocks which will result in
1321 * i_data's format changing. Force the migrate
1322 * to fail by clearing migrate flags
1324 ext4_clear_inode_state(inode
, EXT4_STATE_EXT_MIGRATE
);
1328 * Update reserved blocks/metadata blocks after successful
1329 * block allocation which had been deferred till now. We don't
1330 * support fallocate for non extent files. So we can update
1331 * reserve space here.
1334 (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
))
1335 ext4_da_update_reserve_space(inode
, retval
, 1);
1337 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1338 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1340 up_write((&EXT4_I(inode
)->i_data_sem
));
1341 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
) {
1342 int ret
= check_block_validity(inode
, map
);
1349 /* Maximum number of blocks we map for direct IO at once. */
1350 #define DIO_MAX_BLOCKS 4096
1352 static int _ext4_get_block(struct inode
*inode
, sector_t iblock
,
1353 struct buffer_head
*bh
, int flags
)
1355 handle_t
*handle
= ext4_journal_current_handle();
1356 struct ext4_map_blocks map
;
1357 int ret
= 0, started
= 0;
1360 map
.m_lblk
= iblock
;
1361 map
.m_len
= bh
->b_size
>> inode
->i_blkbits
;
1363 if (flags
&& !handle
) {
1364 /* Direct IO write... */
1365 if (map
.m_len
> DIO_MAX_BLOCKS
)
1366 map
.m_len
= DIO_MAX_BLOCKS
;
1367 dio_credits
= ext4_chunk_trans_blocks(inode
, map
.m_len
);
1368 handle
= ext4_journal_start(inode
, dio_credits
);
1369 if (IS_ERR(handle
)) {
1370 ret
= PTR_ERR(handle
);
1376 ret
= ext4_map_blocks(handle
, inode
, &map
, flags
);
1378 map_bh(bh
, inode
->i_sb
, map
.m_pblk
);
1379 bh
->b_state
= (bh
->b_state
& ~EXT4_MAP_FLAGS
) | map
.m_flags
;
1380 bh
->b_size
= inode
->i_sb
->s_blocksize
* map
.m_len
;
1384 ext4_journal_stop(handle
);
1388 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1389 struct buffer_head
*bh
, int create
)
1391 return _ext4_get_block(inode
, iblock
, bh
,
1392 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1396 * `handle' can be NULL if create is zero
1398 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1399 ext4_lblk_t block
, int create
, int *errp
)
1401 struct ext4_map_blocks map
;
1402 struct buffer_head
*bh
;
1405 J_ASSERT(handle
!= NULL
|| create
== 0);
1409 err
= ext4_map_blocks(handle
, inode
, &map
,
1410 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1418 bh
= sb_getblk(inode
->i_sb
, map
.m_pblk
);
1423 if (map
.m_flags
& EXT4_MAP_NEW
) {
1424 J_ASSERT(create
!= 0);
1425 J_ASSERT(handle
!= NULL
);
1428 * Now that we do not always journal data, we should
1429 * keep in mind whether this should always journal the
1430 * new buffer as metadata. For now, regular file
1431 * writes use ext4_get_block instead, so it's not a
1435 BUFFER_TRACE(bh
, "call get_create_access");
1436 fatal
= ext4_journal_get_create_access(handle
, bh
);
1437 if (!fatal
&& !buffer_uptodate(bh
)) {
1438 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1439 set_buffer_uptodate(bh
);
1442 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1443 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1447 BUFFER_TRACE(bh
, "not a new buffer");
1457 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1458 ext4_lblk_t block
, int create
, int *err
)
1460 struct buffer_head
*bh
;
1462 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1465 if (buffer_uptodate(bh
))
1467 ll_rw_block(READ_META
, 1, &bh
);
1469 if (buffer_uptodate(bh
))
1476 static int walk_page_buffers(handle_t
*handle
,
1477 struct buffer_head
*head
,
1481 int (*fn
)(handle_t
*handle
,
1482 struct buffer_head
*bh
))
1484 struct buffer_head
*bh
;
1485 unsigned block_start
, block_end
;
1486 unsigned blocksize
= head
->b_size
;
1488 struct buffer_head
*next
;
1490 for (bh
= head
, block_start
= 0;
1491 ret
== 0 && (bh
!= head
|| !block_start
);
1492 block_start
= block_end
, bh
= next
) {
1493 next
= bh
->b_this_page
;
1494 block_end
= block_start
+ blocksize
;
1495 if (block_end
<= from
|| block_start
>= to
) {
1496 if (partial
&& !buffer_uptodate(bh
))
1500 err
= (*fn
)(handle
, bh
);
1508 * To preserve ordering, it is essential that the hole instantiation and
1509 * the data write be encapsulated in a single transaction. We cannot
1510 * close off a transaction and start a new one between the ext4_get_block()
1511 * and the commit_write(). So doing the jbd2_journal_start at the start of
1512 * prepare_write() is the right place.
1514 * Also, this function can nest inside ext4_writepage() ->
1515 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1516 * has generated enough buffer credits to do the whole page. So we won't
1517 * block on the journal in that case, which is good, because the caller may
1520 * By accident, ext4 can be reentered when a transaction is open via
1521 * quota file writes. If we were to commit the transaction while thus
1522 * reentered, there can be a deadlock - we would be holding a quota
1523 * lock, and the commit would never complete if another thread had a
1524 * transaction open and was blocking on the quota lock - a ranking
1527 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1528 * will _not_ run commit under these circumstances because handle->h_ref
1529 * is elevated. We'll still have enough credits for the tiny quotafile
1532 static int do_journal_get_write_access(handle_t
*handle
,
1533 struct buffer_head
*bh
)
1535 int dirty
= buffer_dirty(bh
);
1538 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1541 * __block_write_begin() could have dirtied some buffers. Clean
1542 * the dirty bit as jbd2_journal_get_write_access() could complain
1543 * otherwise about fs integrity issues. Setting of the dirty bit
1544 * by __block_write_begin() isn't a real problem here as we clear
1545 * the bit before releasing a page lock and thus writeback cannot
1546 * ever write the buffer.
1549 clear_buffer_dirty(bh
);
1550 ret
= ext4_journal_get_write_access(handle
, bh
);
1552 ret
= ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1557 * Truncate blocks that were not used by write. We have to truncate the
1558 * pagecache as well so that corresponding buffers get properly unmapped.
1560 static void ext4_truncate_failed_write(struct inode
*inode
)
1562 truncate_inode_pages(inode
->i_mapping
, inode
->i_size
);
1563 ext4_truncate(inode
);
1566 static int ext4_get_block_write(struct inode
*inode
, sector_t iblock
,
1567 struct buffer_head
*bh_result
, int create
);
1568 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1569 loff_t pos
, unsigned len
, unsigned flags
,
1570 struct page
**pagep
, void **fsdata
)
1572 struct inode
*inode
= mapping
->host
;
1573 int ret
, needed_blocks
;
1580 trace_ext4_write_begin(inode
, pos
, len
, flags
);
1582 * Reserve one block more for addition to orphan list in case
1583 * we allocate blocks but write fails for some reason
1585 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
1586 index
= pos
>> PAGE_CACHE_SHIFT
;
1587 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1591 handle
= ext4_journal_start(inode
, needed_blocks
);
1592 if (IS_ERR(handle
)) {
1593 ret
= PTR_ERR(handle
);
1597 /* We cannot recurse into the filesystem as the transaction is already
1599 flags
|= AOP_FLAG_NOFS
;
1601 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1603 ext4_journal_stop(handle
);
1609 if (ext4_should_dioread_nolock(inode
))
1610 ret
= __block_write_begin(page
, pos
, len
, ext4_get_block_write
);
1612 ret
= __block_write_begin(page
, pos
, len
, ext4_get_block
);
1614 if (!ret
&& ext4_should_journal_data(inode
)) {
1615 ret
= walk_page_buffers(handle
, page_buffers(page
),
1616 from
, to
, NULL
, do_journal_get_write_access
);
1621 page_cache_release(page
);
1623 * __block_write_begin may have instantiated a few blocks
1624 * outside i_size. Trim these off again. Don't need
1625 * i_size_read because we hold i_mutex.
1627 * Add inode to orphan list in case we crash before
1630 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1631 ext4_orphan_add(handle
, inode
);
1633 ext4_journal_stop(handle
);
1634 if (pos
+ len
> inode
->i_size
) {
1635 ext4_truncate_failed_write(inode
);
1637 * If truncate failed early the inode might
1638 * still be on the orphan list; we need to
1639 * make sure the inode is removed from the
1640 * orphan list in that case.
1643 ext4_orphan_del(NULL
, inode
);
1647 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1653 /* For write_end() in data=journal mode */
1654 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1656 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1658 set_buffer_uptodate(bh
);
1659 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1662 static int ext4_generic_write_end(struct file
*file
,
1663 struct address_space
*mapping
,
1664 loff_t pos
, unsigned len
, unsigned copied
,
1665 struct page
*page
, void *fsdata
)
1667 int i_size_changed
= 0;
1668 struct inode
*inode
= mapping
->host
;
1669 handle_t
*handle
= ext4_journal_current_handle();
1671 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1674 * No need to use i_size_read() here, the i_size
1675 * cannot change under us because we hold i_mutex.
1677 * But it's important to update i_size while still holding page lock:
1678 * page writeout could otherwise come in and zero beyond i_size.
1680 if (pos
+ copied
> inode
->i_size
) {
1681 i_size_write(inode
, pos
+ copied
);
1685 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
1686 /* We need to mark inode dirty even if
1687 * new_i_size is less that inode->i_size
1688 * bu greater than i_disksize.(hint delalloc)
1690 ext4_update_i_disksize(inode
, (pos
+ copied
));
1694 page_cache_release(page
);
1697 * Don't mark the inode dirty under page lock. First, it unnecessarily
1698 * makes the holding time of page lock longer. Second, it forces lock
1699 * ordering of page lock and transaction start for journaling
1703 ext4_mark_inode_dirty(handle
, inode
);
1709 * We need to pick up the new inode size which generic_commit_write gave us
1710 * `file' can be NULL - eg, when called from page_symlink().
1712 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1713 * buffers are managed internally.
1715 static int ext4_ordered_write_end(struct file
*file
,
1716 struct address_space
*mapping
,
1717 loff_t pos
, unsigned len
, unsigned copied
,
1718 struct page
*page
, void *fsdata
)
1720 handle_t
*handle
= ext4_journal_current_handle();
1721 struct inode
*inode
= mapping
->host
;
1724 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
1725 ret
= ext4_jbd2_file_inode(handle
, inode
);
1728 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1731 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1732 /* if we have allocated more blocks and copied
1733 * less. We will have blocks allocated outside
1734 * inode->i_size. So truncate them
1736 ext4_orphan_add(handle
, inode
);
1740 ret2
= ext4_journal_stop(handle
);
1744 if (pos
+ len
> inode
->i_size
) {
1745 ext4_truncate_failed_write(inode
);
1747 * If truncate failed early the inode might still be
1748 * on the orphan list; we need to make sure the inode
1749 * is removed from the orphan list in that case.
1752 ext4_orphan_del(NULL
, inode
);
1756 return ret
? ret
: copied
;
1759 static int ext4_writeback_write_end(struct file
*file
,
1760 struct address_space
*mapping
,
1761 loff_t pos
, unsigned len
, unsigned copied
,
1762 struct page
*page
, void *fsdata
)
1764 handle_t
*handle
= ext4_journal_current_handle();
1765 struct inode
*inode
= mapping
->host
;
1768 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1769 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1772 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1773 /* if we have allocated more blocks and copied
1774 * less. We will have blocks allocated outside
1775 * inode->i_size. So truncate them
1777 ext4_orphan_add(handle
, inode
);
1782 ret2
= ext4_journal_stop(handle
);
1786 if (pos
+ len
> inode
->i_size
) {
1787 ext4_truncate_failed_write(inode
);
1789 * If truncate failed early the inode might still be
1790 * on the orphan list; we need to make sure the inode
1791 * is removed from the orphan list in that case.
1794 ext4_orphan_del(NULL
, inode
);
1797 return ret
? ret
: copied
;
1800 static int ext4_journalled_write_end(struct file
*file
,
1801 struct address_space
*mapping
,
1802 loff_t pos
, unsigned len
, unsigned copied
,
1803 struct page
*page
, void *fsdata
)
1805 handle_t
*handle
= ext4_journal_current_handle();
1806 struct inode
*inode
= mapping
->host
;
1812 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1813 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1817 if (!PageUptodate(page
))
1819 page_zero_new_buffers(page
, from
+copied
, to
);
1822 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1823 to
, &partial
, write_end_fn
);
1825 SetPageUptodate(page
);
1826 new_i_size
= pos
+ copied
;
1827 if (new_i_size
> inode
->i_size
)
1828 i_size_write(inode
, pos
+copied
);
1829 ext4_set_inode_state(inode
, EXT4_STATE_JDATA
);
1830 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1831 ext4_update_i_disksize(inode
, new_i_size
);
1832 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1838 page_cache_release(page
);
1839 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1840 /* if we have allocated more blocks and copied
1841 * less. We will have blocks allocated outside
1842 * inode->i_size. So truncate them
1844 ext4_orphan_add(handle
, inode
);
1846 ret2
= ext4_journal_stop(handle
);
1849 if (pos
+ len
> inode
->i_size
) {
1850 ext4_truncate_failed_write(inode
);
1852 * If truncate failed early the inode might still be
1853 * on the orphan list; we need to make sure the inode
1854 * is removed from the orphan list in that case.
1857 ext4_orphan_del(NULL
, inode
);
1860 return ret
? ret
: copied
;
1864 * Reserve a single block located at lblock
1866 static int ext4_da_reserve_space(struct inode
*inode
, sector_t lblock
)
1869 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1870 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1871 unsigned long md_needed
;
1875 * recalculate the amount of metadata blocks to reserve
1876 * in order to allocate nrblocks
1877 * worse case is one extent per block
1880 spin_lock(&ei
->i_block_reservation_lock
);
1881 md_needed
= ext4_calc_metadata_amount(inode
, lblock
);
1882 trace_ext4_da_reserve_space(inode
, md_needed
);
1883 spin_unlock(&ei
->i_block_reservation_lock
);
1886 * We will charge metadata quota at writeout time; this saves
1887 * us from metadata over-estimation, though we may go over by
1888 * a small amount in the end. Here we just reserve for data.
1890 ret
= dquot_reserve_block(inode
, 1);
1894 * We do still charge estimated metadata to the sb though;
1895 * we cannot afford to run out of free blocks.
1897 if (ext4_claim_free_blocks(sbi
, md_needed
+ 1)) {
1898 dquot_release_reservation_block(inode
, 1);
1899 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1905 spin_lock(&ei
->i_block_reservation_lock
);
1906 ei
->i_reserved_data_blocks
++;
1907 ei
->i_reserved_meta_blocks
+= md_needed
;
1908 spin_unlock(&ei
->i_block_reservation_lock
);
1910 return 0; /* success */
1913 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1915 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1916 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1919 return; /* Nothing to release, exit */
1921 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1923 trace_ext4_da_release_space(inode
, to_free
);
1924 if (unlikely(to_free
> ei
->i_reserved_data_blocks
)) {
1926 * if there aren't enough reserved blocks, then the
1927 * counter is messed up somewhere. Since this
1928 * function is called from invalidate page, it's
1929 * harmless to return without any action.
1931 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "ext4_da_release_space: "
1932 "ino %lu, to_free %d with only %d reserved "
1933 "data blocks\n", inode
->i_ino
, to_free
,
1934 ei
->i_reserved_data_blocks
);
1936 to_free
= ei
->i_reserved_data_blocks
;
1938 ei
->i_reserved_data_blocks
-= to_free
;
1940 if (ei
->i_reserved_data_blocks
== 0) {
1942 * We can release all of the reserved metadata blocks
1943 * only when we have written all of the delayed
1944 * allocation blocks.
1946 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
1947 ei
->i_reserved_meta_blocks
);
1948 ei
->i_reserved_meta_blocks
= 0;
1949 ei
->i_da_metadata_calc_len
= 0;
1952 /* update fs dirty data blocks counter */
1953 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, to_free
);
1955 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1957 dquot_release_reservation_block(inode
, to_free
);
1960 static void ext4_da_page_release_reservation(struct page
*page
,
1961 unsigned long offset
)
1964 struct buffer_head
*head
, *bh
;
1965 unsigned int curr_off
= 0;
1967 head
= page_buffers(page
);
1970 unsigned int next_off
= curr_off
+ bh
->b_size
;
1972 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1974 clear_buffer_delay(bh
);
1976 curr_off
= next_off
;
1977 } while ((bh
= bh
->b_this_page
) != head
);
1978 ext4_da_release_space(page
->mapping
->host
, to_release
);
1982 * Delayed allocation stuff
1986 * mpage_da_submit_io - walks through extent of pages and try to write
1987 * them with writepage() call back
1989 * @mpd->inode: inode
1990 * @mpd->first_page: first page of the extent
1991 * @mpd->next_page: page after the last page of the extent
1993 * By the time mpage_da_submit_io() is called we expect all blocks
1994 * to be allocated. this may be wrong if allocation failed.
1996 * As pages are already locked by write_cache_pages(), we can't use it
1998 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
2001 struct pagevec pvec
;
2002 unsigned long index
, end
;
2003 int ret
= 0, err
, nr_pages
, i
;
2004 struct inode
*inode
= mpd
->inode
;
2005 struct address_space
*mapping
= inode
->i_mapping
;
2007 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
2009 * We need to start from the first_page to the next_page - 1
2010 * to make sure we also write the mapped dirty buffer_heads.
2011 * If we look at mpd->b_blocknr we would only be looking
2012 * at the currently mapped buffer_heads.
2014 index
= mpd
->first_page
;
2015 end
= mpd
->next_page
- 1;
2017 pagevec_init(&pvec
, 0);
2018 while (index
<= end
) {
2019 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2022 for (i
= 0; i
< nr_pages
; i
++) {
2023 struct page
*page
= pvec
.pages
[i
];
2025 index
= page
->index
;
2030 BUG_ON(!PageLocked(page
));
2031 BUG_ON(PageWriteback(page
));
2033 pages_skipped
= mpd
->wbc
->pages_skipped
;
2034 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
2035 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
2037 * have successfully written the page
2038 * without skipping the same
2040 mpd
->pages_written
++;
2042 * In error case, we have to continue because
2043 * remaining pages are still locked
2044 * XXX: unlock and re-dirty them?
2049 pagevec_release(&pvec
);
2055 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
2057 * the function goes through all passed space and put actual disk
2058 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
2060 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
,
2061 struct ext4_map_blocks
*map
)
2063 struct inode
*inode
= mpd
->inode
;
2064 struct address_space
*mapping
= inode
->i_mapping
;
2065 int blocks
= map
->m_len
;
2066 sector_t pblock
= map
->m_pblk
, cur_logical
;
2067 struct buffer_head
*head
, *bh
;
2069 struct pagevec pvec
;
2072 index
= map
->m_lblk
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2073 end
= (map
->m_lblk
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2074 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2076 pagevec_init(&pvec
, 0);
2078 while (index
<= end
) {
2079 /* XXX: optimize tail */
2080 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2083 for (i
= 0; i
< nr_pages
; i
++) {
2084 struct page
*page
= pvec
.pages
[i
];
2086 index
= page
->index
;
2091 BUG_ON(!PageLocked(page
));
2092 BUG_ON(PageWriteback(page
));
2093 BUG_ON(!page_has_buffers(page
));
2095 bh
= page_buffers(page
);
2098 /* skip blocks out of the range */
2100 if (cur_logical
>= map
->m_lblk
)
2103 } while ((bh
= bh
->b_this_page
) != head
);
2106 if (cur_logical
>= map
->m_lblk
+ blocks
)
2109 if (buffer_delay(bh
) || buffer_unwritten(bh
)) {
2111 BUG_ON(bh
->b_bdev
!= inode
->i_sb
->s_bdev
);
2113 if (buffer_delay(bh
)) {
2114 clear_buffer_delay(bh
);
2115 bh
->b_blocknr
= pblock
;
2118 * unwritten already should have
2119 * blocknr assigned. Verify that
2121 clear_buffer_unwritten(bh
);
2122 BUG_ON(bh
->b_blocknr
!= pblock
);
2125 } else if (buffer_mapped(bh
))
2126 BUG_ON(bh
->b_blocknr
!= pblock
);
2128 if (map
->m_flags
& EXT4_MAP_UNINIT
)
2129 set_buffer_uninit(bh
);
2132 } while ((bh
= bh
->b_this_page
) != head
);
2134 pagevec_release(&pvec
);
2139 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
2140 sector_t logical
, long blk_cnt
)
2144 struct pagevec pvec
;
2145 struct inode
*inode
= mpd
->inode
;
2146 struct address_space
*mapping
= inode
->i_mapping
;
2148 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2149 end
= (logical
+ blk_cnt
- 1) >>
2150 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2151 while (index
<= end
) {
2152 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2155 for (i
= 0; i
< nr_pages
; i
++) {
2156 struct page
*page
= pvec
.pages
[i
];
2157 if (page
->index
> end
)
2159 BUG_ON(!PageLocked(page
));
2160 BUG_ON(PageWriteback(page
));
2161 block_invalidatepage(page
, 0);
2162 ClearPageUptodate(page
);
2165 index
= pvec
.pages
[nr_pages
- 1]->index
+ 1;
2166 pagevec_release(&pvec
);
2171 static void ext4_print_free_blocks(struct inode
*inode
)
2173 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2174 printk(KERN_CRIT
"Total free blocks count %lld\n",
2175 ext4_count_free_blocks(inode
->i_sb
));
2176 printk(KERN_CRIT
"Free/Dirty block details\n");
2177 printk(KERN_CRIT
"free_blocks=%lld\n",
2178 (long long) percpu_counter_sum(&sbi
->s_freeblocks_counter
));
2179 printk(KERN_CRIT
"dirty_blocks=%lld\n",
2180 (long long) percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
2181 printk(KERN_CRIT
"Block reservation details\n");
2182 printk(KERN_CRIT
"i_reserved_data_blocks=%u\n",
2183 EXT4_I(inode
)->i_reserved_data_blocks
);
2184 printk(KERN_CRIT
"i_reserved_meta_blocks=%u\n",
2185 EXT4_I(inode
)->i_reserved_meta_blocks
);
2190 * mpage_da_map_blocks - go through given space
2192 * @mpd - bh describing space
2194 * The function skips space we know is already mapped to disk blocks.
2197 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
2199 int err
, blks
, get_blocks_flags
;
2200 struct ext4_map_blocks map
;
2201 sector_t next
= mpd
->b_blocknr
;
2202 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2203 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
2204 handle_t
*handle
= NULL
;
2207 * We consider only non-mapped and non-allocated blocks
2209 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2210 !(mpd
->b_state
& (1 << BH_Delay
)) &&
2211 !(mpd
->b_state
& (1 << BH_Unwritten
)))
2215 * If we didn't accumulate anything to write simply return
2220 handle
= ext4_journal_current_handle();
2224 * Call ext4_map_blocks() to allocate any delayed allocation
2225 * blocks, or to convert an uninitialized extent to be
2226 * initialized (in the case where we have written into
2227 * one or more preallocated blocks).
2229 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2230 * indicate that we are on the delayed allocation path. This
2231 * affects functions in many different parts of the allocation
2232 * call path. This flag exists primarily because we don't
2233 * want to change *many* call functions, so ext4_map_blocks()
2234 * will set the magic i_delalloc_reserved_flag once the
2235 * inode's allocation semaphore is taken.
2237 * If the blocks in questions were delalloc blocks, set
2238 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2239 * variables are updated after the blocks have been allocated.
2242 map
.m_len
= max_blocks
;
2243 get_blocks_flags
= EXT4_GET_BLOCKS_CREATE
;
2244 if (ext4_should_dioread_nolock(mpd
->inode
))
2245 get_blocks_flags
|= EXT4_GET_BLOCKS_IO_CREATE_EXT
;
2246 if (mpd
->b_state
& (1 << BH_Delay
))
2247 get_blocks_flags
|= EXT4_GET_BLOCKS_DELALLOC_RESERVE
;
2249 blks
= ext4_map_blocks(handle
, mpd
->inode
, &map
, get_blocks_flags
);
2251 struct super_block
*sb
= mpd
->inode
->i_sb
;
2255 * If get block returns with error we simply
2256 * return. Later writepage will redirty the page and
2257 * writepages will find the dirty page again
2262 if (err
== -ENOSPC
&&
2263 ext4_count_free_blocks(sb
)) {
2269 * get block failure will cause us to loop in
2270 * writepages, because a_ops->writepage won't be able
2271 * to make progress. The page will be redirtied by
2272 * writepage and writepages will again try to write
2275 if (!(EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
)) {
2276 ext4_msg(sb
, KERN_CRIT
,
2277 "delayed block allocation failed for inode %lu "
2278 "at logical offset %llu with max blocks %zd "
2279 "with error %d", mpd
->inode
->i_ino
,
2280 (unsigned long long) next
,
2281 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2282 ext4_msg(sb
, KERN_CRIT
,
2283 "This should not happen!! Data will be lost\n");
2285 ext4_print_free_blocks(mpd
->inode
);
2287 /* invalidate all the pages */
2288 ext4_da_block_invalidatepages(mpd
, next
,
2289 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2294 if (map
.m_flags
& EXT4_MAP_NEW
) {
2295 struct block_device
*bdev
= mpd
->inode
->i_sb
->s_bdev
;
2298 for (i
= 0; i
< map
.m_len
; i
++)
2299 unmap_underlying_metadata(bdev
, map
.m_pblk
+ i
);
2303 * If blocks are delayed marked, we need to
2304 * put actual blocknr and drop delayed bit
2306 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2307 (mpd
->b_state
& (1 << BH_Unwritten
)))
2308 mpage_put_bnr_to_bhs(mpd
, &map
);
2310 if (ext4_should_order_data(mpd
->inode
)) {
2311 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
2317 * Update on-disk size along with block allocation.
2319 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
2320 if (disksize
> i_size_read(mpd
->inode
))
2321 disksize
= i_size_read(mpd
->inode
);
2322 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
2323 ext4_update_i_disksize(mpd
->inode
, disksize
);
2324 return ext4_mark_inode_dirty(handle
, mpd
->inode
);
2330 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2331 (1 << BH_Delay) | (1 << BH_Unwritten))
2334 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2336 * @mpd->lbh - extent of blocks
2337 * @logical - logical number of the block in the file
2338 * @bh - bh of the block (used to access block's state)
2340 * the function is used to collect contig. blocks in same state
2342 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2343 sector_t logical
, size_t b_size
,
2344 unsigned long b_state
)
2347 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2350 * XXX Don't go larger than mballoc is willing to allocate
2351 * This is a stopgap solution. We eventually need to fold
2352 * mpage_da_submit_io() into this function and then call
2353 * ext4_map_blocks() multiple times in a loop
2355 if (nrblocks
>= 8*1024*1024/mpd
->inode
->i_sb
->s_blocksize
)
2358 /* check if thereserved journal credits might overflow */
2359 if (!(ext4_test_inode_flag(mpd
->inode
, EXT4_INODE_EXTENTS
))) {
2360 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2362 * With non-extent format we are limited by the journal
2363 * credit available. Total credit needed to insert
2364 * nrblocks contiguous blocks is dependent on the
2365 * nrblocks. So limit nrblocks.
2368 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2369 EXT4_MAX_TRANS_DATA
) {
2371 * Adding the new buffer_head would make it cross the
2372 * allowed limit for which we have journal credit
2373 * reserved. So limit the new bh->b_size
2375 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2376 mpd
->inode
->i_blkbits
;
2377 /* we will do mpage_da_submit_io in the next loop */
2381 * First block in the extent
2383 if (mpd
->b_size
== 0) {
2384 mpd
->b_blocknr
= logical
;
2385 mpd
->b_size
= b_size
;
2386 mpd
->b_state
= b_state
& BH_FLAGS
;
2390 next
= mpd
->b_blocknr
+ nrblocks
;
2392 * Can we merge the block to our big extent?
2394 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2395 mpd
->b_size
+= b_size
;
2401 * We couldn't merge the block to our extent, so we
2402 * need to flush current extent and start new one
2404 if (mpage_da_map_blocks(mpd
) == 0)
2405 mpage_da_submit_io(mpd
);
2410 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
)
2412 return (buffer_delay(bh
) || buffer_unwritten(bh
)) && buffer_dirty(bh
);
2416 * __mpage_da_writepage - finds extent of pages and blocks
2418 * @page: page to consider
2419 * @wbc: not used, we just follow rules
2422 * The function finds extents of pages and scan them for all blocks.
2424 static int __mpage_da_writepage(struct page
*page
,
2425 struct writeback_control
*wbc
, void *data
)
2427 struct mpage_da_data
*mpd
= data
;
2428 struct inode
*inode
= mpd
->inode
;
2429 struct buffer_head
*bh
, *head
;
2433 * Can we merge this page to current extent?
2435 if (mpd
->next_page
!= page
->index
) {
2437 * Nope, we can't. So, we map non-allocated blocks
2438 * and start IO on them using writepage()
2440 if (mpd
->next_page
!= mpd
->first_page
) {
2441 if (mpage_da_map_blocks(mpd
) == 0)
2442 mpage_da_submit_io(mpd
);
2444 * skip rest of the page in the page_vec
2447 redirty_page_for_writepage(wbc
, page
);
2449 return MPAGE_DA_EXTENT_TAIL
;
2453 * Start next extent of pages ...
2455 mpd
->first_page
= page
->index
;
2465 mpd
->next_page
= page
->index
+ 1;
2466 logical
= (sector_t
) page
->index
<<
2467 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2469 if (!page_has_buffers(page
)) {
2470 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2471 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2473 return MPAGE_DA_EXTENT_TAIL
;
2476 * Page with regular buffer heads, just add all dirty ones
2478 head
= page_buffers(page
);
2481 BUG_ON(buffer_locked(bh
));
2483 * We need to try to allocate
2484 * unmapped blocks in the same page.
2485 * Otherwise we won't make progress
2486 * with the page in ext4_writepage
2488 if (ext4_bh_delay_or_unwritten(NULL
, bh
)) {
2489 mpage_add_bh_to_extent(mpd
, logical
,
2493 return MPAGE_DA_EXTENT_TAIL
;
2494 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2496 * mapped dirty buffer. We need to update
2497 * the b_state because we look at
2498 * b_state in mpage_da_map_blocks. We don't
2499 * update b_size because if we find an
2500 * unmapped buffer_head later we need to
2501 * use the b_state flag of that buffer_head.
2503 if (mpd
->b_size
== 0)
2504 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2507 } while ((bh
= bh
->b_this_page
) != head
);
2514 * This is a special get_blocks_t callback which is used by
2515 * ext4_da_write_begin(). It will either return mapped block or
2516 * reserve space for a single block.
2518 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2519 * We also have b_blocknr = -1 and b_bdev initialized properly
2521 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2522 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2523 * initialized properly.
2525 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2526 struct buffer_head
*bh
, int create
)
2528 struct ext4_map_blocks map
;
2530 sector_t invalid_block
= ~((sector_t
) 0xffff);
2532 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
2535 BUG_ON(create
== 0);
2536 BUG_ON(bh
->b_size
!= inode
->i_sb
->s_blocksize
);
2538 map
.m_lblk
= iblock
;
2542 * first, we need to know whether the block is allocated already
2543 * preallocated blocks are unmapped but should treated
2544 * the same as allocated blocks.
2546 ret
= ext4_map_blocks(NULL
, inode
, &map
, 0);
2550 if (buffer_delay(bh
))
2551 return 0; /* Not sure this could or should happen */
2553 * XXX: __block_write_begin() unmaps passed block, is it OK?
2555 ret
= ext4_da_reserve_space(inode
, iblock
);
2557 /* not enough space to reserve */
2560 map_bh(bh
, inode
->i_sb
, invalid_block
);
2562 set_buffer_delay(bh
);
2566 map_bh(bh
, inode
->i_sb
, map
.m_pblk
);
2567 bh
->b_state
= (bh
->b_state
& ~EXT4_MAP_FLAGS
) | map
.m_flags
;
2569 if (buffer_unwritten(bh
)) {
2570 /* A delayed write to unwritten bh should be marked
2571 * new and mapped. Mapped ensures that we don't do
2572 * get_block multiple times when we write to the same
2573 * offset and new ensures that we do proper zero out
2574 * for partial write.
2577 set_buffer_mapped(bh
);
2583 * This function is used as a standard get_block_t calback function
2584 * when there is no desire to allocate any blocks. It is used as a
2585 * callback function for block_write_begin() and block_write_full_page().
2586 * These functions should only try to map a single block at a time.
2588 * Since this function doesn't do block allocations even if the caller
2589 * requests it by passing in create=1, it is critically important that
2590 * any caller checks to make sure that any buffer heads are returned
2591 * by this function are either all already mapped or marked for
2592 * delayed allocation before calling block_write_full_page(). Otherwise,
2593 * b_blocknr could be left unitialized, and the page write functions will
2594 * be taken by surprise.
2596 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
2597 struct buffer_head
*bh_result
, int create
)
2599 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2600 return _ext4_get_block(inode
, iblock
, bh_result
, 0);
2603 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2609 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2615 static int __ext4_journalled_writepage(struct page
*page
,
2618 struct address_space
*mapping
= page
->mapping
;
2619 struct inode
*inode
= mapping
->host
;
2620 struct buffer_head
*page_bufs
;
2621 handle_t
*handle
= NULL
;
2625 page_bufs
= page_buffers(page
);
2627 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bget_one
);
2628 /* As soon as we unlock the page, it can go away, but we have
2629 * references to buffers so we are safe */
2632 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
2633 if (IS_ERR(handle
)) {
2634 ret
= PTR_ERR(handle
);
2638 ret
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2639 do_journal_get_write_access
);
2641 err
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2645 err
= ext4_journal_stop(handle
);
2649 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bput_one
);
2650 ext4_set_inode_state(inode
, EXT4_STATE_JDATA
);
2655 static int ext4_set_bh_endio(struct buffer_head
*bh
, struct inode
*inode
);
2656 static void ext4_end_io_buffer_write(struct buffer_head
*bh
, int uptodate
);
2659 * Note that we don't need to start a transaction unless we're journaling data
2660 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2661 * need to file the inode to the transaction's list in ordered mode because if
2662 * we are writing back data added by write(), the inode is already there and if
2663 * we are writing back data modified via mmap(), noone guarantees in which
2664 * transaction the data will hit the disk. In case we are journaling data, we
2665 * cannot start transaction directly because transaction start ranks above page
2666 * lock so we have to do some magic.
2668 * This function can get called via...
2669 * - ext4_da_writepages after taking page lock (have journal handle)
2670 * - journal_submit_inode_data_buffers (no journal handle)
2671 * - shrink_page_list via pdflush (no journal handle)
2672 * - grab_page_cache when doing write_begin (have journal handle)
2674 * We don't do any block allocation in this function. If we have page with
2675 * multiple blocks we need to write those buffer_heads that are mapped. This
2676 * is important for mmaped based write. So if we do with blocksize 1K
2677 * truncate(f, 1024);
2678 * a = mmap(f, 0, 4096);
2680 * truncate(f, 4096);
2681 * we have in the page first buffer_head mapped via page_mkwrite call back
2682 * but other bufer_heads would be unmapped but dirty(dirty done via the
2683 * do_wp_page). So writepage should write the first block. If we modify
2684 * the mmap area beyond 1024 we will again get a page_fault and the
2685 * page_mkwrite callback will do the block allocation and mark the
2686 * buffer_heads mapped.
2688 * We redirty the page if we have any buffer_heads that is either delay or
2689 * unwritten in the page.
2691 * We can get recursively called as show below.
2693 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2696 * But since we don't do any block allocation we should not deadlock.
2697 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2699 static int ext4_writepage(struct page
*page
,
2700 struct writeback_control
*wbc
)
2705 struct buffer_head
*page_bufs
= NULL
;
2706 struct inode
*inode
= page
->mapping
->host
;
2708 trace_ext4_writepage(inode
, page
);
2709 size
= i_size_read(inode
);
2710 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2711 len
= size
& ~PAGE_CACHE_MASK
;
2713 len
= PAGE_CACHE_SIZE
;
2715 if (page_has_buffers(page
)) {
2716 page_bufs
= page_buffers(page
);
2717 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2718 ext4_bh_delay_or_unwritten
)) {
2720 * We don't want to do block allocation
2721 * So redirty the page and return
2722 * We may reach here when we do a journal commit
2723 * via journal_submit_inode_data_buffers.
2724 * If we don't have mapping block we just ignore
2725 * them. We can also reach here via shrink_page_list
2727 redirty_page_for_writepage(wbc
, page
);
2733 * The test for page_has_buffers() is subtle:
2734 * We know the page is dirty but it lost buffers. That means
2735 * that at some moment in time after write_begin()/write_end()
2736 * has been called all buffers have been clean and thus they
2737 * must have been written at least once. So they are all
2738 * mapped and we can happily proceed with mapping them
2739 * and writing the page.
2741 * Try to initialize the buffer_heads and check whether
2742 * all are mapped and non delay. We don't want to
2743 * do block allocation here.
2745 ret
= __block_write_begin(page
, 0, len
,
2746 noalloc_get_block_write
);
2748 page_bufs
= page_buffers(page
);
2749 /* check whether all are mapped and non delay */
2750 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2751 ext4_bh_delay_or_unwritten
)) {
2752 redirty_page_for_writepage(wbc
, page
);
2758 * We can't do block allocation here
2759 * so just redity the page and unlock
2762 redirty_page_for_writepage(wbc
, page
);
2766 /* now mark the buffer_heads as dirty and uptodate */
2767 block_commit_write(page
, 0, len
);
2770 if (PageChecked(page
) && ext4_should_journal_data(inode
)) {
2772 * It's mmapped pagecache. Add buffers and journal it. There
2773 * doesn't seem much point in redirtying the page here.
2775 ClearPageChecked(page
);
2776 return __ext4_journalled_writepage(page
, len
);
2779 if (page_bufs
&& buffer_uninit(page_bufs
)) {
2780 ext4_set_bh_endio(page_bufs
, inode
);
2781 ret
= block_write_full_page_endio(page
, noalloc_get_block_write
,
2782 wbc
, ext4_end_io_buffer_write
);
2784 ret
= block_write_full_page(page
, noalloc_get_block_write
,
2791 * This is called via ext4_da_writepages() to
2792 * calulate the total number of credits to reserve to fit
2793 * a single extent allocation into a single transaction,
2794 * ext4_da_writpeages() will loop calling this before
2795 * the block allocation.
2798 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2800 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2803 * With non-extent format the journal credit needed to
2804 * insert nrblocks contiguous block is dependent on
2805 * number of contiguous block. So we will limit
2806 * number of contiguous block to a sane value
2808 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) &&
2809 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2810 max_blocks
= EXT4_MAX_TRANS_DATA
;
2812 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2816 * write_cache_pages_da - walk the list of dirty pages of the given
2817 * address space and call the callback function (which usually writes
2820 * This is a forked version of write_cache_pages(). Differences:
2821 * Range cyclic is ignored.
2822 * no_nrwrite_index_update is always presumed true
2824 static int write_cache_pages_da(struct address_space
*mapping
,
2825 struct writeback_control
*wbc
,
2826 struct mpage_da_data
*mpd
)
2830 struct pagevec pvec
;
2833 pgoff_t end
; /* Inclusive */
2834 long nr_to_write
= wbc
->nr_to_write
;
2836 pagevec_init(&pvec
, 0);
2837 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2838 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2840 while (!done
&& (index
<= end
)) {
2843 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
2844 PAGECACHE_TAG_DIRTY
,
2845 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1);
2849 for (i
= 0; i
< nr_pages
; i
++) {
2850 struct page
*page
= pvec
.pages
[i
];
2853 * At this point, the page may be truncated or
2854 * invalidated (changing page->mapping to NULL), or
2855 * even swizzled back from swapper_space to tmpfs file
2856 * mapping. However, page->index will not change
2857 * because we have a reference on the page.
2859 if (page
->index
> end
) {
2867 * Page truncated or invalidated. We can freely skip it
2868 * then, even for data integrity operations: the page
2869 * has disappeared concurrently, so there could be no
2870 * real expectation of this data interity operation
2871 * even if there is now a new, dirty page at the same
2872 * pagecache address.
2874 if (unlikely(page
->mapping
!= mapping
)) {
2880 if (!PageDirty(page
)) {
2881 /* someone wrote it for us */
2882 goto continue_unlock
;
2885 if (PageWriteback(page
)) {
2886 if (wbc
->sync_mode
!= WB_SYNC_NONE
)
2887 wait_on_page_writeback(page
);
2889 goto continue_unlock
;
2892 BUG_ON(PageWriteback(page
));
2893 if (!clear_page_dirty_for_io(page
))
2894 goto continue_unlock
;
2896 ret
= __mpage_da_writepage(page
, wbc
, mpd
);
2897 if (unlikely(ret
)) {
2898 if (ret
== AOP_WRITEPAGE_ACTIVATE
) {
2907 if (nr_to_write
> 0) {
2909 if (nr_to_write
== 0 &&
2910 wbc
->sync_mode
== WB_SYNC_NONE
) {
2912 * We stop writing back only if we are
2913 * not doing integrity sync. In case of
2914 * integrity sync we have to keep going
2915 * because someone may be concurrently
2916 * dirtying pages, and we might have
2917 * synced a lot of newly appeared dirty
2918 * pages, but have not synced all of the
2926 pagevec_release(&pvec
);
2933 static int ext4_da_writepages(struct address_space
*mapping
,
2934 struct writeback_control
*wbc
)
2937 int range_whole
= 0;
2938 handle_t
*handle
= NULL
;
2939 struct mpage_da_data mpd
;
2940 struct inode
*inode
= mapping
->host
;
2941 int pages_written
= 0;
2943 unsigned int max_pages
;
2944 int range_cyclic
, cycled
= 1, io_done
= 0;
2945 int needed_blocks
, ret
= 0;
2946 long desired_nr_to_write
, nr_to_writebump
= 0;
2947 loff_t range_start
= wbc
->range_start
;
2948 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2950 trace_ext4_da_writepages(inode
, wbc
);
2953 * No pages to write? This is mainly a kludge to avoid starting
2954 * a transaction for special inodes like journal inode on last iput()
2955 * because that could violate lock ordering on umount
2957 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2961 * If the filesystem has aborted, it is read-only, so return
2962 * right away instead of dumping stack traces later on that
2963 * will obscure the real source of the problem. We test
2964 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2965 * the latter could be true if the filesystem is mounted
2966 * read-only, and in that case, ext4_da_writepages should
2967 * *never* be called, so if that ever happens, we would want
2970 if (unlikely(sbi
->s_mount_flags
& EXT4_MF_FS_ABORTED
))
2973 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2976 range_cyclic
= wbc
->range_cyclic
;
2977 if (wbc
->range_cyclic
) {
2978 index
= mapping
->writeback_index
;
2981 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2982 wbc
->range_end
= LLONG_MAX
;
2983 wbc
->range_cyclic
= 0;
2985 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2988 * This works around two forms of stupidity. The first is in
2989 * the writeback code, which caps the maximum number of pages
2990 * written to be 1024 pages. This is wrong on multiple
2991 * levels; different architectues have a different page size,
2992 * which changes the maximum amount of data which gets
2993 * written. Secondly, 4 megabytes is way too small. XFS
2994 * forces this value to be 16 megabytes by multiplying
2995 * nr_to_write parameter by four, and then relies on its
2996 * allocator to allocate larger extents to make them
2997 * contiguous. Unfortunately this brings us to the second
2998 * stupidity, which is that ext4's mballoc code only allocates
2999 * at most 2048 blocks. So we force contiguous writes up to
3000 * the number of dirty blocks in the inode, or
3001 * sbi->max_writeback_mb_bump whichever is smaller.
3003 max_pages
= sbi
->s_max_writeback_mb_bump
<< (20 - PAGE_CACHE_SHIFT
);
3004 if (!range_cyclic
&& range_whole
)
3005 desired_nr_to_write
= wbc
->nr_to_write
* 8;
3007 desired_nr_to_write
= ext4_num_dirty_pages(inode
, index
,
3009 if (desired_nr_to_write
> max_pages
)
3010 desired_nr_to_write
= max_pages
;
3012 if (wbc
->nr_to_write
< desired_nr_to_write
) {
3013 nr_to_writebump
= desired_nr_to_write
- wbc
->nr_to_write
;
3014 wbc
->nr_to_write
= desired_nr_to_write
;
3018 mpd
.inode
= mapping
->host
;
3020 pages_skipped
= wbc
->pages_skipped
;
3023 while (!ret
&& wbc
->nr_to_write
> 0) {
3026 * we insert one extent at a time. So we need
3027 * credit needed for single extent allocation.
3028 * journalled mode is currently not supported
3031 BUG_ON(ext4_should_journal_data(inode
));
3032 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
3034 /* start a new transaction*/
3035 handle
= ext4_journal_start(inode
, needed_blocks
);
3036 if (IS_ERR(handle
)) {
3037 ret
= PTR_ERR(handle
);
3038 ext4_msg(inode
->i_sb
, KERN_CRIT
, "%s: jbd2_start: "
3039 "%ld pages, ino %lu; err %d", __func__
,
3040 wbc
->nr_to_write
, inode
->i_ino
, ret
);
3041 goto out_writepages
;
3045 * Now call __mpage_da_writepage to find the next
3046 * contiguous region of logical blocks that need
3047 * blocks to be allocated by ext4. We don't actually
3048 * submit the blocks for I/O here, even though
3049 * write_cache_pages thinks it will, and will set the
3050 * pages as clean for write before calling
3051 * __mpage_da_writepage().
3059 mpd
.pages_written
= 0;
3061 ret
= write_cache_pages_da(mapping
, wbc
, &mpd
);
3063 * If we have a contiguous extent of pages and we
3064 * haven't done the I/O yet, map the blocks and submit
3067 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
3068 if (mpage_da_map_blocks(&mpd
) == 0)
3069 mpage_da_submit_io(&mpd
);
3071 ret
= MPAGE_DA_EXTENT_TAIL
;
3073 trace_ext4_da_write_pages(inode
, &mpd
);
3074 wbc
->nr_to_write
-= mpd
.pages_written
;
3076 ext4_journal_stop(handle
);
3078 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
3079 /* commit the transaction which would
3080 * free blocks released in the transaction
3083 jbd2_journal_force_commit_nested(sbi
->s_journal
);
3084 wbc
->pages_skipped
= pages_skipped
;
3086 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
3088 * got one extent now try with
3091 pages_written
+= mpd
.pages_written
;
3092 wbc
->pages_skipped
= pages_skipped
;
3095 } else if (wbc
->nr_to_write
)
3097 * There is no more writeout needed
3098 * or we requested for a noblocking writeout
3099 * and we found the device congested
3103 if (!io_done
&& !cycled
) {
3106 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
3107 wbc
->range_end
= mapping
->writeback_index
- 1;
3110 if (pages_skipped
!= wbc
->pages_skipped
)
3111 ext4_msg(inode
->i_sb
, KERN_CRIT
,
3112 "This should not happen leaving %s "
3113 "with nr_to_write = %ld ret = %d",
3114 __func__
, wbc
->nr_to_write
, ret
);
3117 index
+= pages_written
;
3118 wbc
->range_cyclic
= range_cyclic
;
3119 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
3121 * set the writeback_index so that range_cyclic
3122 * mode will write it back later
3124 mapping
->writeback_index
= index
;
3127 wbc
->nr_to_write
-= nr_to_writebump
;
3128 wbc
->range_start
= range_start
;
3129 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
3133 #define FALL_BACK_TO_NONDELALLOC 1
3134 static int ext4_nonda_switch(struct super_block
*sb
)
3136 s64 free_blocks
, dirty_blocks
;
3137 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3140 * switch to non delalloc mode if we are running low
3141 * on free block. The free block accounting via percpu
3142 * counters can get slightly wrong with percpu_counter_batch getting
3143 * accumulated on each CPU without updating global counters
3144 * Delalloc need an accurate free block accounting. So switch
3145 * to non delalloc when we are near to error range.
3147 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
3148 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
3149 if (2 * free_blocks
< 3 * dirty_blocks
||
3150 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
3152 * free block count is less than 150% of dirty blocks
3153 * or free blocks is less than watermark
3158 * Even if we don't switch but are nearing capacity,
3159 * start pushing delalloc when 1/2 of free blocks are dirty.
3161 if (free_blocks
< 2 * dirty_blocks
)
3162 writeback_inodes_sb_if_idle(sb
);
3167 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
3168 loff_t pos
, unsigned len
, unsigned flags
,
3169 struct page
**pagep
, void **fsdata
)
3171 int ret
, retries
= 0;
3174 struct inode
*inode
= mapping
->host
;
3177 index
= pos
>> PAGE_CACHE_SHIFT
;
3179 if (ext4_nonda_switch(inode
->i_sb
)) {
3180 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
3181 return ext4_write_begin(file
, mapping
, pos
,
3182 len
, flags
, pagep
, fsdata
);
3184 *fsdata
= (void *)0;
3185 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
3188 * With delayed allocation, we don't log the i_disksize update
3189 * if there is delayed block allocation. But we still need
3190 * to journalling the i_disksize update if writes to the end
3191 * of file which has an already mapped buffer.
3193 handle
= ext4_journal_start(inode
, 1);
3194 if (IS_ERR(handle
)) {
3195 ret
= PTR_ERR(handle
);
3198 /* We cannot recurse into the filesystem as the transaction is already
3200 flags
|= AOP_FLAG_NOFS
;
3202 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
3204 ext4_journal_stop(handle
);
3210 ret
= __block_write_begin(page
, pos
, len
, ext4_da_get_block_prep
);
3213 ext4_journal_stop(handle
);
3214 page_cache_release(page
);
3216 * block_write_begin may have instantiated a few blocks
3217 * outside i_size. Trim these off again. Don't need
3218 * i_size_read because we hold i_mutex.
3220 if (pos
+ len
> inode
->i_size
)
3221 ext4_truncate_failed_write(inode
);
3224 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3231 * Check if we should update i_disksize
3232 * when write to the end of file but not require block allocation
3234 static int ext4_da_should_update_i_disksize(struct page
*page
,
3235 unsigned long offset
)
3237 struct buffer_head
*bh
;
3238 struct inode
*inode
= page
->mapping
->host
;
3242 bh
= page_buffers(page
);
3243 idx
= offset
>> inode
->i_blkbits
;
3245 for (i
= 0; i
< idx
; i
++)
3246 bh
= bh
->b_this_page
;
3248 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
3253 static int ext4_da_write_end(struct file
*file
,
3254 struct address_space
*mapping
,
3255 loff_t pos
, unsigned len
, unsigned copied
,
3256 struct page
*page
, void *fsdata
)
3258 struct inode
*inode
= mapping
->host
;
3260 handle_t
*handle
= ext4_journal_current_handle();
3262 unsigned long start
, end
;
3263 int write_mode
= (int)(unsigned long)fsdata
;
3265 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
3266 if (ext4_should_order_data(inode
)) {
3267 return ext4_ordered_write_end(file
, mapping
, pos
,
3268 len
, copied
, page
, fsdata
);
3269 } else if (ext4_should_writeback_data(inode
)) {
3270 return ext4_writeback_write_end(file
, mapping
, pos
,
3271 len
, copied
, page
, fsdata
);
3277 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
3278 start
= pos
& (PAGE_CACHE_SIZE
- 1);
3279 end
= start
+ copied
- 1;
3282 * generic_write_end() will run mark_inode_dirty() if i_size
3283 * changes. So let's piggyback the i_disksize mark_inode_dirty
3287 new_i_size
= pos
+ copied
;
3288 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3289 if (ext4_da_should_update_i_disksize(page
, end
)) {
3290 down_write(&EXT4_I(inode
)->i_data_sem
);
3291 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3293 * Updating i_disksize when extending file
3294 * without needing block allocation
3296 if (ext4_should_order_data(inode
))
3297 ret
= ext4_jbd2_file_inode(handle
,
3300 EXT4_I(inode
)->i_disksize
= new_i_size
;
3302 up_write(&EXT4_I(inode
)->i_data_sem
);
3303 /* We need to mark inode dirty even if
3304 * new_i_size is less that inode->i_size
3305 * bu greater than i_disksize.(hint delalloc)
3307 ext4_mark_inode_dirty(handle
, inode
);
3310 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
3315 ret2
= ext4_journal_stop(handle
);
3319 return ret
? ret
: copied
;
3322 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
3325 * Drop reserved blocks
3327 BUG_ON(!PageLocked(page
));
3328 if (!page_has_buffers(page
))
3331 ext4_da_page_release_reservation(page
, offset
);
3334 ext4_invalidatepage(page
, offset
);
3340 * Force all delayed allocation blocks to be allocated for a given inode.
3342 int ext4_alloc_da_blocks(struct inode
*inode
)
3344 trace_ext4_alloc_da_blocks(inode
);
3346 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
3347 !EXT4_I(inode
)->i_reserved_meta_blocks
)
3351 * We do something simple for now. The filemap_flush() will
3352 * also start triggering a write of the data blocks, which is
3353 * not strictly speaking necessary (and for users of
3354 * laptop_mode, not even desirable). However, to do otherwise
3355 * would require replicating code paths in:
3357 * ext4_da_writepages() ->
3358 * write_cache_pages() ---> (via passed in callback function)
3359 * __mpage_da_writepage() -->
3360 * mpage_add_bh_to_extent()
3361 * mpage_da_map_blocks()
3363 * The problem is that write_cache_pages(), located in
3364 * mm/page-writeback.c, marks pages clean in preparation for
3365 * doing I/O, which is not desirable if we're not planning on
3368 * We could call write_cache_pages(), and then redirty all of
3369 * the pages by calling redirty_page_for_writeback() but that
3370 * would be ugly in the extreme. So instead we would need to
3371 * replicate parts of the code in the above functions,
3372 * simplifying them becuase we wouldn't actually intend to
3373 * write out the pages, but rather only collect contiguous
3374 * logical block extents, call the multi-block allocator, and
3375 * then update the buffer heads with the block allocations.
3377 * For now, though, we'll cheat by calling filemap_flush(),
3378 * which will map the blocks, and start the I/O, but not
3379 * actually wait for the I/O to complete.
3381 return filemap_flush(inode
->i_mapping
);
3385 * bmap() is special. It gets used by applications such as lilo and by
3386 * the swapper to find the on-disk block of a specific piece of data.
3388 * Naturally, this is dangerous if the block concerned is still in the
3389 * journal. If somebody makes a swapfile on an ext4 data-journaling
3390 * filesystem and enables swap, then they may get a nasty shock when the
3391 * data getting swapped to that swapfile suddenly gets overwritten by
3392 * the original zero's written out previously to the journal and
3393 * awaiting writeback in the kernel's buffer cache.
3395 * So, if we see any bmap calls here on a modified, data-journaled file,
3396 * take extra steps to flush any blocks which might be in the cache.
3398 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
3400 struct inode
*inode
= mapping
->host
;
3404 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
3405 test_opt(inode
->i_sb
, DELALLOC
)) {
3407 * With delalloc we want to sync the file
3408 * so that we can make sure we allocate
3411 filemap_write_and_wait(mapping
);
3414 if (EXT4_JOURNAL(inode
) &&
3415 ext4_test_inode_state(inode
, EXT4_STATE_JDATA
)) {
3417 * This is a REALLY heavyweight approach, but the use of
3418 * bmap on dirty files is expected to be extremely rare:
3419 * only if we run lilo or swapon on a freshly made file
3420 * do we expect this to happen.
3422 * (bmap requires CAP_SYS_RAWIO so this does not
3423 * represent an unprivileged user DOS attack --- we'd be
3424 * in trouble if mortal users could trigger this path at
3427 * NB. EXT4_STATE_JDATA is not set on files other than
3428 * regular files. If somebody wants to bmap a directory
3429 * or symlink and gets confused because the buffer
3430 * hasn't yet been flushed to disk, they deserve
3431 * everything they get.
3434 ext4_clear_inode_state(inode
, EXT4_STATE_JDATA
);
3435 journal
= EXT4_JOURNAL(inode
);
3436 jbd2_journal_lock_updates(journal
);
3437 err
= jbd2_journal_flush(journal
);
3438 jbd2_journal_unlock_updates(journal
);
3444 return generic_block_bmap(mapping
, block
, ext4_get_block
);
3447 static int ext4_readpage(struct file
*file
, struct page
*page
)
3449 return mpage_readpage(page
, ext4_get_block
);
3453 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3454 struct list_head
*pages
, unsigned nr_pages
)
3456 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3459 static void ext4_free_io_end(ext4_io_end_t
*io
)
3468 static void ext4_invalidatepage_free_endio(struct page
*page
, unsigned long offset
)
3470 struct buffer_head
*head
, *bh
;
3471 unsigned int curr_off
= 0;
3473 if (!page_has_buffers(page
))
3475 head
= bh
= page_buffers(page
);
3477 if (offset
<= curr_off
&& test_clear_buffer_uninit(bh
)
3479 ext4_free_io_end(bh
->b_private
);
3480 bh
->b_private
= NULL
;
3481 bh
->b_end_io
= NULL
;
3483 curr_off
= curr_off
+ bh
->b_size
;
3484 bh
= bh
->b_this_page
;
3485 } while (bh
!= head
);
3488 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3490 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3493 * free any io_end structure allocated for buffers to be discarded
3495 if (ext4_should_dioread_nolock(page
->mapping
->host
))
3496 ext4_invalidatepage_free_endio(page
, offset
);
3498 * If it's a full truncate we just forget about the pending dirtying
3501 ClearPageChecked(page
);
3504 jbd2_journal_invalidatepage(journal
, page
, offset
);
3506 block_invalidatepage(page
, offset
);
3509 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3511 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3513 WARN_ON(PageChecked(page
));
3514 if (!page_has_buffers(page
))
3517 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3519 return try_to_free_buffers(page
);
3523 * O_DIRECT for ext3 (or indirect map) based files
3525 * If the O_DIRECT write will extend the file then add this inode to the
3526 * orphan list. So recovery will truncate it back to the original size
3527 * if the machine crashes during the write.
3529 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3530 * crashes then stale disk data _may_ be exposed inside the file. But current
3531 * VFS code falls back into buffered path in that case so we are safe.
3533 static ssize_t
ext4_ind_direct_IO(int rw
, struct kiocb
*iocb
,
3534 const struct iovec
*iov
, loff_t offset
,
3535 unsigned long nr_segs
)
3537 struct file
*file
= iocb
->ki_filp
;
3538 struct inode
*inode
= file
->f_mapping
->host
;
3539 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3543 size_t count
= iov_length(iov
, nr_segs
);
3547 loff_t final_size
= offset
+ count
;
3549 if (final_size
> inode
->i_size
) {
3550 /* Credits for sb + inode write */
3551 handle
= ext4_journal_start(inode
, 2);
3552 if (IS_ERR(handle
)) {
3553 ret
= PTR_ERR(handle
);
3556 ret
= ext4_orphan_add(handle
, inode
);
3558 ext4_journal_stop(handle
);
3562 ei
->i_disksize
= inode
->i_size
;
3563 ext4_journal_stop(handle
);
3568 if (rw
== READ
&& ext4_should_dioread_nolock(inode
))
3569 ret
= __blockdev_direct_IO(rw
, iocb
, inode
,
3570 inode
->i_sb
->s_bdev
, iov
,
3572 ext4_get_block
, NULL
, NULL
, 0);
3574 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3575 inode
->i_sb
->s_bdev
, iov
,
3577 ext4_get_block
, NULL
);
3579 if (unlikely((rw
& WRITE
) && ret
< 0)) {
3580 loff_t isize
= i_size_read(inode
);
3581 loff_t end
= offset
+ iov_length(iov
, nr_segs
);
3584 vmtruncate(inode
, isize
);
3587 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3593 /* Credits for sb + inode write */
3594 handle
= ext4_journal_start(inode
, 2);
3595 if (IS_ERR(handle
)) {
3596 /* This is really bad luck. We've written the data
3597 * but cannot extend i_size. Bail out and pretend
3598 * the write failed... */
3599 ret
= PTR_ERR(handle
);
3601 ext4_orphan_del(NULL
, inode
);
3606 ext4_orphan_del(handle
, inode
);
3608 loff_t end
= offset
+ ret
;
3609 if (end
> inode
->i_size
) {
3610 ei
->i_disksize
= end
;
3611 i_size_write(inode
, end
);
3613 * We're going to return a positive `ret'
3614 * here due to non-zero-length I/O, so there's
3615 * no way of reporting error returns from
3616 * ext4_mark_inode_dirty() to userspace. So
3619 ext4_mark_inode_dirty(handle
, inode
);
3622 err
= ext4_journal_stop(handle
);
3631 * ext4_get_block used when preparing for a DIO write or buffer write.
3632 * We allocate an uinitialized extent if blocks haven't been allocated.
3633 * The extent will be converted to initialized after the IO is complete.
3635 static int ext4_get_block_write(struct inode
*inode
, sector_t iblock
,
3636 struct buffer_head
*bh_result
, int create
)
3638 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
3639 inode
->i_ino
, create
);
3640 return _ext4_get_block(inode
, iblock
, bh_result
,
3641 EXT4_GET_BLOCKS_IO_CREATE_EXT
);
3644 static void dump_completed_IO(struct inode
* inode
)
3647 struct list_head
*cur
, *before
, *after
;
3648 ext4_io_end_t
*io
, *io0
, *io1
;
3649 unsigned long flags
;
3651 if (list_empty(&EXT4_I(inode
)->i_completed_io_list
)){
3652 ext4_debug("inode %lu completed_io list is empty\n", inode
->i_ino
);
3656 ext4_debug("Dump inode %lu completed_io list \n", inode
->i_ino
);
3657 spin_lock_irqsave(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3658 list_for_each_entry(io
, &EXT4_I(inode
)->i_completed_io_list
, list
){
3661 io0
= container_of(before
, ext4_io_end_t
, list
);
3663 io1
= container_of(after
, ext4_io_end_t
, list
);
3665 ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
3666 io
, inode
->i_ino
, io0
, io1
);
3668 spin_unlock_irqrestore(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3673 * check a range of space and convert unwritten extents to written.
3675 static int ext4_end_io_nolock(ext4_io_end_t
*io
)
3677 struct inode
*inode
= io
->inode
;
3678 loff_t offset
= io
->offset
;
3679 ssize_t size
= io
->size
;
3682 ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
3683 "list->prev 0x%p\n",
3684 io
, inode
->i_ino
, io
->list
.next
, io
->list
.prev
);
3686 if (list_empty(&io
->list
))
3689 if (io
->flag
!= EXT4_IO_UNWRITTEN
)
3692 ret
= ext4_convert_unwritten_extents(inode
, offset
, size
);
3694 printk(KERN_EMERG
"%s: failed to convert unwritten"
3695 "extents to written extents, error is %d"
3696 " io is still on inode %lu aio dio list\n",
3697 __func__
, ret
, inode
->i_ino
);
3702 aio_complete(io
->iocb
, io
->result
, 0);
3703 /* clear the DIO AIO unwritten flag */
3709 * work on completed aio dio IO, to convert unwritten extents to extents
3711 static void ext4_end_io_work(struct work_struct
*work
)
3713 ext4_io_end_t
*io
= container_of(work
, ext4_io_end_t
, work
);
3714 struct inode
*inode
= io
->inode
;
3715 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3716 unsigned long flags
;
3719 mutex_lock(&inode
->i_mutex
);
3720 ret
= ext4_end_io_nolock(io
);
3722 mutex_unlock(&inode
->i_mutex
);
3726 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3727 if (!list_empty(&io
->list
))
3728 list_del_init(&io
->list
);
3729 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3730 mutex_unlock(&inode
->i_mutex
);
3731 ext4_free_io_end(io
);
3735 * This function is called from ext4_sync_file().
3737 * When IO is completed, the work to convert unwritten extents to
3738 * written is queued on workqueue but may not get immediately
3739 * scheduled. When fsync is called, we need to ensure the
3740 * conversion is complete before fsync returns.
3741 * The inode keeps track of a list of pending/completed IO that
3742 * might needs to do the conversion. This function walks through
3743 * the list and convert the related unwritten extents for completed IO
3745 * The function return the number of pending IOs on success.
3747 int flush_completed_IO(struct inode
*inode
)
3750 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3751 unsigned long flags
;
3755 if (list_empty(&ei
->i_completed_io_list
))
3758 dump_completed_IO(inode
);
3759 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3760 while (!list_empty(&ei
->i_completed_io_list
)){
3761 io
= list_entry(ei
->i_completed_io_list
.next
,
3762 ext4_io_end_t
, list
);
3764 * Calling ext4_end_io_nolock() to convert completed
3767 * When ext4_sync_file() is called, run_queue() may already
3768 * about to flush the work corresponding to this io structure.
3769 * It will be upset if it founds the io structure related
3770 * to the work-to-be schedule is freed.
3772 * Thus we need to keep the io structure still valid here after
3773 * convertion finished. The io structure has a flag to
3774 * avoid double converting from both fsync and background work
3777 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3778 ret
= ext4_end_io_nolock(io
);
3779 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3783 list_del_init(&io
->list
);
3785 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3786 return (ret2
< 0) ? ret2
: 0;
3789 static ext4_io_end_t
*ext4_init_io_end (struct inode
*inode
, gfp_t flags
)
3791 ext4_io_end_t
*io
= NULL
;
3793 io
= kmalloc(sizeof(*io
), flags
);
3804 INIT_WORK(&io
->work
, ext4_end_io_work
);
3805 INIT_LIST_HEAD(&io
->list
);
3811 static void ext4_end_io_dio(struct kiocb
*iocb
, loff_t offset
,
3812 ssize_t size
, void *private, int ret
,
3815 ext4_io_end_t
*io_end
= iocb
->private;
3816 struct workqueue_struct
*wq
;
3817 unsigned long flags
;
3818 struct ext4_inode_info
*ei
;
3820 /* if not async direct IO or dio with 0 bytes write, just return */
3821 if (!io_end
|| !size
)
3824 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3825 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3826 iocb
->private, io_end
->inode
->i_ino
, iocb
, offset
,
3829 /* if not aio dio with unwritten extents, just free io and return */
3830 if (io_end
->flag
!= EXT4_IO_UNWRITTEN
){
3831 ext4_free_io_end(io_end
);
3832 iocb
->private = NULL
;
3835 aio_complete(iocb
, ret
, 0);
3839 io_end
->offset
= offset
;
3840 io_end
->size
= size
;
3842 io_end
->iocb
= iocb
;
3843 io_end
->result
= ret
;
3845 wq
= EXT4_SB(io_end
->inode
->i_sb
)->dio_unwritten_wq
;
3847 /* queue the work to convert unwritten extents to written */
3848 queue_work(wq
, &io_end
->work
);
3850 /* Add the io_end to per-inode completed aio dio list*/
3851 ei
= EXT4_I(io_end
->inode
);
3852 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3853 list_add_tail(&io_end
->list
, &ei
->i_completed_io_list
);
3854 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3855 iocb
->private = NULL
;
3858 static void ext4_end_io_buffer_write(struct buffer_head
*bh
, int uptodate
)
3860 ext4_io_end_t
*io_end
= bh
->b_private
;
3861 struct workqueue_struct
*wq
;
3862 struct inode
*inode
;
3863 unsigned long flags
;
3865 if (!test_clear_buffer_uninit(bh
) || !io_end
)
3868 if (!(io_end
->inode
->i_sb
->s_flags
& MS_ACTIVE
)) {
3869 printk("sb umounted, discard end_io request for inode %lu\n",
3870 io_end
->inode
->i_ino
);
3871 ext4_free_io_end(io_end
);
3875 io_end
->flag
= EXT4_IO_UNWRITTEN
;
3876 inode
= io_end
->inode
;
3878 /* Add the io_end to per-inode completed io list*/
3879 spin_lock_irqsave(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3880 list_add_tail(&io_end
->list
, &EXT4_I(inode
)->i_completed_io_list
);
3881 spin_unlock_irqrestore(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3883 wq
= EXT4_SB(inode
->i_sb
)->dio_unwritten_wq
;
3884 /* queue the work to convert unwritten extents to written */
3885 queue_work(wq
, &io_end
->work
);
3887 bh
->b_private
= NULL
;
3888 bh
->b_end_io
= NULL
;
3889 clear_buffer_uninit(bh
);
3890 end_buffer_async_write(bh
, uptodate
);
3893 static int ext4_set_bh_endio(struct buffer_head
*bh
, struct inode
*inode
)
3895 ext4_io_end_t
*io_end
;
3896 struct page
*page
= bh
->b_page
;
3897 loff_t offset
= (sector_t
)page
->index
<< PAGE_CACHE_SHIFT
;
3898 size_t size
= bh
->b_size
;
3901 io_end
= ext4_init_io_end(inode
, GFP_ATOMIC
);
3903 if (printk_ratelimit())
3904 printk(KERN_WARNING
"%s: allocation fail\n", __func__
);
3908 io_end
->offset
= offset
;
3909 io_end
->size
= size
;
3911 * We need to hold a reference to the page to make sure it
3912 * doesn't get evicted before ext4_end_io_work() has a chance
3913 * to convert the extent from written to unwritten.
3915 io_end
->page
= page
;
3916 get_page(io_end
->page
);
3918 bh
->b_private
= io_end
;
3919 bh
->b_end_io
= ext4_end_io_buffer_write
;
3924 * For ext4 extent files, ext4 will do direct-io write to holes,
3925 * preallocated extents, and those write extend the file, no need to
3926 * fall back to buffered IO.
3928 * For holes, we fallocate those blocks, mark them as unintialized
3929 * If those blocks were preallocated, we mark sure they are splited, but
3930 * still keep the range to write as unintialized.
3932 * The unwrritten extents will be converted to written when DIO is completed.
3933 * For async direct IO, since the IO may still pending when return, we
3934 * set up an end_io call back function, which will do the convertion
3935 * when async direct IO completed.
3937 * If the O_DIRECT write will extend the file then add this inode to the
3938 * orphan list. So recovery will truncate it back to the original size
3939 * if the machine crashes during the write.
3942 static ssize_t
ext4_ext_direct_IO(int rw
, struct kiocb
*iocb
,
3943 const struct iovec
*iov
, loff_t offset
,
3944 unsigned long nr_segs
)
3946 struct file
*file
= iocb
->ki_filp
;
3947 struct inode
*inode
= file
->f_mapping
->host
;
3949 size_t count
= iov_length(iov
, nr_segs
);
3951 loff_t final_size
= offset
+ count
;
3952 if (rw
== WRITE
&& final_size
<= inode
->i_size
) {
3954 * We could direct write to holes and fallocate.
3956 * Allocated blocks to fill the hole are marked as uninitialized
3957 * to prevent paralel buffered read to expose the stale data
3958 * before DIO complete the data IO.
3960 * As to previously fallocated extents, ext4 get_block
3961 * will just simply mark the buffer mapped but still
3962 * keep the extents uninitialized.
3964 * for non AIO case, we will convert those unwritten extents
3965 * to written after return back from blockdev_direct_IO.
3967 * for async DIO, the conversion needs to be defered when
3968 * the IO is completed. The ext4 end_io callback function
3969 * will be called to take care of the conversion work.
3970 * Here for async case, we allocate an io_end structure to
3973 iocb
->private = NULL
;
3974 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3975 if (!is_sync_kiocb(iocb
)) {
3976 iocb
->private = ext4_init_io_end(inode
, GFP_NOFS
);
3980 * we save the io structure for current async
3981 * direct IO, so that later ext4_map_blocks()
3982 * could flag the io structure whether there
3983 * is a unwritten extents needs to be converted
3984 * when IO is completed.
3986 EXT4_I(inode
)->cur_aio_dio
= iocb
->private;
3989 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3990 inode
->i_sb
->s_bdev
, iov
,
3992 ext4_get_block_write
,
3995 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3997 * The io_end structure takes a reference to the inode,
3998 * that structure needs to be destroyed and the
3999 * reference to the inode need to be dropped, when IO is
4000 * complete, even with 0 byte write, or failed.
4002 * In the successful AIO DIO case, the io_end structure will be
4003 * desctroyed and the reference to the inode will be dropped
4004 * after the end_io call back function is called.
4006 * In the case there is 0 byte write, or error case, since
4007 * VFS direct IO won't invoke the end_io call back function,
4008 * we need to free the end_io structure here.
4010 if (ret
!= -EIOCBQUEUED
&& ret
<= 0 && iocb
->private) {
4011 ext4_free_io_end(iocb
->private);
4012 iocb
->private = NULL
;
4013 } else if (ret
> 0 && ext4_test_inode_state(inode
,
4014 EXT4_STATE_DIO_UNWRITTEN
)) {
4017 * for non AIO case, since the IO is already
4018 * completed, we could do the convertion right here
4020 err
= ext4_convert_unwritten_extents(inode
,
4024 ext4_clear_inode_state(inode
, EXT4_STATE_DIO_UNWRITTEN
);
4029 /* for write the the end of file case, we fall back to old way */
4030 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
4033 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
4034 const struct iovec
*iov
, loff_t offset
,
4035 unsigned long nr_segs
)
4037 struct file
*file
= iocb
->ki_filp
;
4038 struct inode
*inode
= file
->f_mapping
->host
;
4040 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
4041 return ext4_ext_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
4043 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
4047 * Pages can be marked dirty completely asynchronously from ext4's journalling
4048 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
4049 * much here because ->set_page_dirty is called under VFS locks. The page is
4050 * not necessarily locked.
4052 * We cannot just dirty the page and leave attached buffers clean, because the
4053 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
4054 * or jbddirty because all the journalling code will explode.
4056 * So what we do is to mark the page "pending dirty" and next time writepage
4057 * is called, propagate that into the buffers appropriately.
4059 static int ext4_journalled_set_page_dirty(struct page
*page
)
4061 SetPageChecked(page
);
4062 return __set_page_dirty_nobuffers(page
);
4065 static const struct address_space_operations ext4_ordered_aops
= {
4066 .readpage
= ext4_readpage
,
4067 .readpages
= ext4_readpages
,
4068 .writepage
= ext4_writepage
,
4069 .sync_page
= block_sync_page
,
4070 .write_begin
= ext4_write_begin
,
4071 .write_end
= ext4_ordered_write_end
,
4073 .invalidatepage
= ext4_invalidatepage
,
4074 .releasepage
= ext4_releasepage
,
4075 .direct_IO
= ext4_direct_IO
,
4076 .migratepage
= buffer_migrate_page
,
4077 .is_partially_uptodate
= block_is_partially_uptodate
,
4078 .error_remove_page
= generic_error_remove_page
,
4081 static const struct address_space_operations ext4_writeback_aops
= {
4082 .readpage
= ext4_readpage
,
4083 .readpages
= ext4_readpages
,
4084 .writepage
= ext4_writepage
,
4085 .sync_page
= block_sync_page
,
4086 .write_begin
= ext4_write_begin
,
4087 .write_end
= ext4_writeback_write_end
,
4089 .invalidatepage
= ext4_invalidatepage
,
4090 .releasepage
= ext4_releasepage
,
4091 .direct_IO
= ext4_direct_IO
,
4092 .migratepage
= buffer_migrate_page
,
4093 .is_partially_uptodate
= block_is_partially_uptodate
,
4094 .error_remove_page
= generic_error_remove_page
,
4097 static const struct address_space_operations ext4_journalled_aops
= {
4098 .readpage
= ext4_readpage
,
4099 .readpages
= ext4_readpages
,
4100 .writepage
= ext4_writepage
,
4101 .sync_page
= block_sync_page
,
4102 .write_begin
= ext4_write_begin
,
4103 .write_end
= ext4_journalled_write_end
,
4104 .set_page_dirty
= ext4_journalled_set_page_dirty
,
4106 .invalidatepage
= ext4_invalidatepage
,
4107 .releasepage
= ext4_releasepage
,
4108 .is_partially_uptodate
= block_is_partially_uptodate
,
4109 .error_remove_page
= generic_error_remove_page
,
4112 static const struct address_space_operations ext4_da_aops
= {
4113 .readpage
= ext4_readpage
,
4114 .readpages
= ext4_readpages
,
4115 .writepage
= ext4_writepage
,
4116 .writepages
= ext4_da_writepages
,
4117 .sync_page
= block_sync_page
,
4118 .write_begin
= ext4_da_write_begin
,
4119 .write_end
= ext4_da_write_end
,
4121 .invalidatepage
= ext4_da_invalidatepage
,
4122 .releasepage
= ext4_releasepage
,
4123 .direct_IO
= ext4_direct_IO
,
4124 .migratepage
= buffer_migrate_page
,
4125 .is_partially_uptodate
= block_is_partially_uptodate
,
4126 .error_remove_page
= generic_error_remove_page
,
4129 void ext4_set_aops(struct inode
*inode
)
4131 if (ext4_should_order_data(inode
) &&
4132 test_opt(inode
->i_sb
, DELALLOC
))
4133 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
4134 else if (ext4_should_order_data(inode
))
4135 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
4136 else if (ext4_should_writeback_data(inode
) &&
4137 test_opt(inode
->i_sb
, DELALLOC
))
4138 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
4139 else if (ext4_should_writeback_data(inode
))
4140 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
4142 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
4146 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
4147 * up to the end of the block which corresponds to `from'.
4148 * This required during truncate. We need to physically zero the tail end
4149 * of that block so it doesn't yield old data if the file is later grown.
4151 int ext4_block_truncate_page(handle_t
*handle
,
4152 struct address_space
*mapping
, loff_t from
)
4154 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
4155 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
4156 unsigned blocksize
, length
, pos
;
4158 struct inode
*inode
= mapping
->host
;
4159 struct buffer_head
*bh
;
4163 page
= find_or_create_page(mapping
, from
>> PAGE_CACHE_SHIFT
,
4164 mapping_gfp_mask(mapping
) & ~__GFP_FS
);
4168 blocksize
= inode
->i_sb
->s_blocksize
;
4169 length
= blocksize
- (offset
& (blocksize
- 1));
4170 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
4172 if (!page_has_buffers(page
))
4173 create_empty_buffers(page
, blocksize
, 0);
4175 /* Find the buffer that contains "offset" */
4176 bh
= page_buffers(page
);
4178 while (offset
>= pos
) {
4179 bh
= bh
->b_this_page
;
4185 if (buffer_freed(bh
)) {
4186 BUFFER_TRACE(bh
, "freed: skip");
4190 if (!buffer_mapped(bh
)) {
4191 BUFFER_TRACE(bh
, "unmapped");
4192 ext4_get_block(inode
, iblock
, bh
, 0);
4193 /* unmapped? It's a hole - nothing to do */
4194 if (!buffer_mapped(bh
)) {
4195 BUFFER_TRACE(bh
, "still unmapped");
4200 /* Ok, it's mapped. Make sure it's up-to-date */
4201 if (PageUptodate(page
))
4202 set_buffer_uptodate(bh
);
4204 if (!buffer_uptodate(bh
)) {
4206 ll_rw_block(READ
, 1, &bh
);
4208 /* Uhhuh. Read error. Complain and punt. */
4209 if (!buffer_uptodate(bh
))
4213 if (ext4_should_journal_data(inode
)) {
4214 BUFFER_TRACE(bh
, "get write access");
4215 err
= ext4_journal_get_write_access(handle
, bh
);
4220 zero_user(page
, offset
, length
);
4222 BUFFER_TRACE(bh
, "zeroed end of block");
4225 if (ext4_should_journal_data(inode
)) {
4226 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
4228 if (ext4_should_order_data(inode
))
4229 err
= ext4_jbd2_file_inode(handle
, inode
);
4230 mark_buffer_dirty(bh
);
4235 page_cache_release(page
);
4240 * Probably it should be a library function... search for first non-zero word
4241 * or memcmp with zero_page, whatever is better for particular architecture.
4244 static inline int all_zeroes(__le32
*p
, __le32
*q
)
4253 * ext4_find_shared - find the indirect blocks for partial truncation.
4254 * @inode: inode in question
4255 * @depth: depth of the affected branch
4256 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4257 * @chain: place to store the pointers to partial indirect blocks
4258 * @top: place to the (detached) top of branch
4260 * This is a helper function used by ext4_truncate().
4262 * When we do truncate() we may have to clean the ends of several
4263 * indirect blocks but leave the blocks themselves alive. Block is
4264 * partially truncated if some data below the new i_size is refered
4265 * from it (and it is on the path to the first completely truncated
4266 * data block, indeed). We have to free the top of that path along
4267 * with everything to the right of the path. Since no allocation
4268 * past the truncation point is possible until ext4_truncate()
4269 * finishes, we may safely do the latter, but top of branch may
4270 * require special attention - pageout below the truncation point
4271 * might try to populate it.
4273 * We atomically detach the top of branch from the tree, store the
4274 * block number of its root in *@top, pointers to buffer_heads of
4275 * partially truncated blocks - in @chain[].bh and pointers to
4276 * their last elements that should not be removed - in
4277 * @chain[].p. Return value is the pointer to last filled element
4280 * The work left to caller to do the actual freeing of subtrees:
4281 * a) free the subtree starting from *@top
4282 * b) free the subtrees whose roots are stored in
4283 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4284 * c) free the subtrees growing from the inode past the @chain[0].
4285 * (no partially truncated stuff there). */
4287 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
4288 ext4_lblk_t offsets
[4], Indirect chain
[4],
4291 Indirect
*partial
, *p
;
4295 /* Make k index the deepest non-null offset + 1 */
4296 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
4298 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
4299 /* Writer: pointers */
4301 partial
= chain
+ k
-1;
4303 * If the branch acquired continuation since we've looked at it -
4304 * fine, it should all survive and (new) top doesn't belong to us.
4306 if (!partial
->key
&& *partial
->p
)
4309 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
4312 * OK, we've found the last block that must survive. The rest of our
4313 * branch should be detached before unlocking. However, if that rest
4314 * of branch is all ours and does not grow immediately from the inode
4315 * it's easier to cheat and just decrement partial->p.
4317 if (p
== chain
+ k
- 1 && p
> chain
) {
4321 /* Nope, don't do this in ext4. Must leave the tree intact */
4328 while (partial
> p
) {
4329 brelse(partial
->bh
);
4337 * Zero a number of block pointers in either an inode or an indirect block.
4338 * If we restart the transaction we must again get write access to the
4339 * indirect block for further modification.
4341 * We release `count' blocks on disk, but (last - first) may be greater
4342 * than `count' because there can be holes in there.
4344 static int ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
4345 struct buffer_head
*bh
,
4346 ext4_fsblk_t block_to_free
,
4347 unsigned long count
, __le32
*first
,
4351 int flags
= EXT4_FREE_BLOCKS_FORGET
| EXT4_FREE_BLOCKS_VALIDATED
;
4353 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
4354 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4356 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), block_to_free
,
4358 EXT4_ERROR_INODE(inode
, "attempt to clear invalid "
4359 "blocks %llu len %lu",
4360 (unsigned long long) block_to_free
, count
);
4364 if (try_to_extend_transaction(handle
, inode
)) {
4366 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4367 ext4_handle_dirty_metadata(handle
, inode
, bh
);
4369 ext4_mark_inode_dirty(handle
, inode
);
4370 ext4_truncate_restart_trans(handle
, inode
,
4371 blocks_for_truncate(inode
));
4373 BUFFER_TRACE(bh
, "retaking write access");
4374 ext4_journal_get_write_access(handle
, bh
);
4378 for (p
= first
; p
< last
; p
++)
4381 ext4_free_blocks(handle
, inode
, 0, block_to_free
, count
, flags
);
4386 * ext4_free_data - free a list of data blocks
4387 * @handle: handle for this transaction
4388 * @inode: inode we are dealing with
4389 * @this_bh: indirect buffer_head which contains *@first and *@last
4390 * @first: array of block numbers
4391 * @last: points immediately past the end of array
4393 * We are freeing all blocks refered from that array (numbers are stored as
4394 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4396 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4397 * blocks are contiguous then releasing them at one time will only affect one
4398 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4399 * actually use a lot of journal space.
4401 * @this_bh will be %NULL if @first and @last point into the inode's direct
4404 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
4405 struct buffer_head
*this_bh
,
4406 __le32
*first
, __le32
*last
)
4408 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
4409 unsigned long count
= 0; /* Number of blocks in the run */
4410 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
4413 ext4_fsblk_t nr
; /* Current block # */
4414 __le32
*p
; /* Pointer into inode/ind
4415 for current block */
4418 if (this_bh
) { /* For indirect block */
4419 BUFFER_TRACE(this_bh
, "get_write_access");
4420 err
= ext4_journal_get_write_access(handle
, this_bh
);
4421 /* Important: if we can't update the indirect pointers
4422 * to the blocks, we can't free them. */
4427 for (p
= first
; p
< last
; p
++) {
4428 nr
= le32_to_cpu(*p
);
4430 /* accumulate blocks to free if they're contiguous */
4433 block_to_free_p
= p
;
4435 } else if (nr
== block_to_free
+ count
) {
4438 if (ext4_clear_blocks(handle
, inode
, this_bh
,
4439 block_to_free
, count
,
4440 block_to_free_p
, p
))
4443 block_to_free_p
= p
;
4450 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
4451 count
, block_to_free_p
, p
);
4454 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
4457 * The buffer head should have an attached journal head at this
4458 * point. However, if the data is corrupted and an indirect
4459 * block pointed to itself, it would have been detached when
4460 * the block was cleared. Check for this instead of OOPSing.
4462 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
4463 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
4465 EXT4_ERROR_INODE(inode
,
4466 "circular indirect block detected at "
4468 (unsigned long long) this_bh
->b_blocknr
);
4473 * ext4_free_branches - free an array of branches
4474 * @handle: JBD handle for this transaction
4475 * @inode: inode we are dealing with
4476 * @parent_bh: the buffer_head which contains *@first and *@last
4477 * @first: array of block numbers
4478 * @last: pointer immediately past the end of array
4479 * @depth: depth of the branches to free
4481 * We are freeing all blocks refered from these branches (numbers are
4482 * stored as little-endian 32-bit) and updating @inode->i_blocks
4485 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
4486 struct buffer_head
*parent_bh
,
4487 __le32
*first
, __le32
*last
, int depth
)
4492 if (ext4_handle_is_aborted(handle
))
4496 struct buffer_head
*bh
;
4497 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4499 while (--p
>= first
) {
4500 nr
= le32_to_cpu(*p
);
4502 continue; /* A hole */
4504 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
),
4506 EXT4_ERROR_INODE(inode
,
4507 "invalid indirect mapped "
4508 "block %lu (level %d)",
4509 (unsigned long) nr
, depth
);
4513 /* Go read the buffer for the next level down */
4514 bh
= sb_bread(inode
->i_sb
, nr
);
4517 * A read failure? Report error and clear slot
4521 EXT4_ERROR_INODE_BLOCK(inode
, nr
,
4526 /* This zaps the entire block. Bottom up. */
4527 BUFFER_TRACE(bh
, "free child branches");
4528 ext4_free_branches(handle
, inode
, bh
,
4529 (__le32
*) bh
->b_data
,
4530 (__le32
*) bh
->b_data
+ addr_per_block
,
4534 * Everything below this this pointer has been
4535 * released. Now let this top-of-subtree go.
4537 * We want the freeing of this indirect block to be
4538 * atomic in the journal with the updating of the
4539 * bitmap block which owns it. So make some room in
4542 * We zero the parent pointer *after* freeing its
4543 * pointee in the bitmaps, so if extend_transaction()
4544 * for some reason fails to put the bitmap changes and
4545 * the release into the same transaction, recovery
4546 * will merely complain about releasing a free block,
4547 * rather than leaking blocks.
4549 if (ext4_handle_is_aborted(handle
))
4551 if (try_to_extend_transaction(handle
, inode
)) {
4552 ext4_mark_inode_dirty(handle
, inode
);
4553 ext4_truncate_restart_trans(handle
, inode
,
4554 blocks_for_truncate(inode
));
4558 * The forget flag here is critical because if
4559 * we are journaling (and not doing data
4560 * journaling), we have to make sure a revoke
4561 * record is written to prevent the journal
4562 * replay from overwriting the (former)
4563 * indirect block if it gets reallocated as a
4564 * data block. This must happen in the same
4565 * transaction where the data blocks are
4568 ext4_free_blocks(handle
, inode
, 0, nr
, 1,
4569 EXT4_FREE_BLOCKS_METADATA
|
4570 EXT4_FREE_BLOCKS_FORGET
);
4574 * The block which we have just freed is
4575 * pointed to by an indirect block: journal it
4577 BUFFER_TRACE(parent_bh
, "get_write_access");
4578 if (!ext4_journal_get_write_access(handle
,
4581 BUFFER_TRACE(parent_bh
,
4582 "call ext4_handle_dirty_metadata");
4583 ext4_handle_dirty_metadata(handle
,
4590 /* We have reached the bottom of the tree. */
4591 BUFFER_TRACE(parent_bh
, "free data blocks");
4592 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
4596 int ext4_can_truncate(struct inode
*inode
)
4598 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
4600 if (S_ISREG(inode
->i_mode
))
4602 if (S_ISDIR(inode
->i_mode
))
4604 if (S_ISLNK(inode
->i_mode
))
4605 return !ext4_inode_is_fast_symlink(inode
);
4612 * We block out ext4_get_block() block instantiations across the entire
4613 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4614 * simultaneously on behalf of the same inode.
4616 * As we work through the truncate and commmit bits of it to the journal there
4617 * is one core, guiding principle: the file's tree must always be consistent on
4618 * disk. We must be able to restart the truncate after a crash.
4620 * The file's tree may be transiently inconsistent in memory (although it
4621 * probably isn't), but whenever we close off and commit a journal transaction,
4622 * the contents of (the filesystem + the journal) must be consistent and
4623 * restartable. It's pretty simple, really: bottom up, right to left (although
4624 * left-to-right works OK too).
4626 * Note that at recovery time, journal replay occurs *before* the restart of
4627 * truncate against the orphan inode list.
4629 * The committed inode has the new, desired i_size (which is the same as
4630 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4631 * that this inode's truncate did not complete and it will again call
4632 * ext4_truncate() to have another go. So there will be instantiated blocks
4633 * to the right of the truncation point in a crashed ext4 filesystem. But
4634 * that's fine - as long as they are linked from the inode, the post-crash
4635 * ext4_truncate() run will find them and release them.
4637 void ext4_truncate(struct inode
*inode
)
4640 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4641 __le32
*i_data
= ei
->i_data
;
4642 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4643 struct address_space
*mapping
= inode
->i_mapping
;
4644 ext4_lblk_t offsets
[4];
4649 ext4_lblk_t last_block
;
4650 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
4652 if (!ext4_can_truncate(inode
))
4655 ext4_clear_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
);
4657 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
4658 ext4_set_inode_state(inode
, EXT4_STATE_DA_ALLOC_CLOSE
);
4660 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
4661 ext4_ext_truncate(inode
);
4665 handle
= start_transaction(inode
);
4667 return; /* AKPM: return what? */
4669 last_block
= (inode
->i_size
+ blocksize
-1)
4670 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
4672 if (inode
->i_size
& (blocksize
- 1))
4673 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
4676 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
4678 goto out_stop
; /* error */
4681 * OK. This truncate is going to happen. We add the inode to the
4682 * orphan list, so that if this truncate spans multiple transactions,
4683 * and we crash, we will resume the truncate when the filesystem
4684 * recovers. It also marks the inode dirty, to catch the new size.
4686 * Implication: the file must always be in a sane, consistent
4687 * truncatable state while each transaction commits.
4689 if (ext4_orphan_add(handle
, inode
))
4693 * From here we block out all ext4_get_block() callers who want to
4694 * modify the block allocation tree.
4696 down_write(&ei
->i_data_sem
);
4698 ext4_discard_preallocations(inode
);
4701 * The orphan list entry will now protect us from any crash which
4702 * occurs before the truncate completes, so it is now safe to propagate
4703 * the new, shorter inode size (held for now in i_size) into the
4704 * on-disk inode. We do this via i_disksize, which is the value which
4705 * ext4 *really* writes onto the disk inode.
4707 ei
->i_disksize
= inode
->i_size
;
4709 if (n
== 1) { /* direct blocks */
4710 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
4711 i_data
+ EXT4_NDIR_BLOCKS
);
4715 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
4716 /* Kill the top of shared branch (not detached) */
4718 if (partial
== chain
) {
4719 /* Shared branch grows from the inode */
4720 ext4_free_branches(handle
, inode
, NULL
,
4721 &nr
, &nr
+1, (chain
+n
-1) - partial
);
4724 * We mark the inode dirty prior to restart,
4725 * and prior to stop. No need for it here.
4728 /* Shared branch grows from an indirect block */
4729 BUFFER_TRACE(partial
->bh
, "get_write_access");
4730 ext4_free_branches(handle
, inode
, partial
->bh
,
4732 partial
->p
+1, (chain
+n
-1) - partial
);
4735 /* Clear the ends of indirect blocks on the shared branch */
4736 while (partial
> chain
) {
4737 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
4738 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
4739 (chain
+n
-1) - partial
);
4740 BUFFER_TRACE(partial
->bh
, "call brelse");
4741 brelse(partial
->bh
);
4745 /* Kill the remaining (whole) subtrees */
4746 switch (offsets
[0]) {
4748 nr
= i_data
[EXT4_IND_BLOCK
];
4750 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4751 i_data
[EXT4_IND_BLOCK
] = 0;
4753 case EXT4_IND_BLOCK
:
4754 nr
= i_data
[EXT4_DIND_BLOCK
];
4756 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4757 i_data
[EXT4_DIND_BLOCK
] = 0;
4759 case EXT4_DIND_BLOCK
:
4760 nr
= i_data
[EXT4_TIND_BLOCK
];
4762 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4763 i_data
[EXT4_TIND_BLOCK
] = 0;
4765 case EXT4_TIND_BLOCK
:
4769 up_write(&ei
->i_data_sem
);
4770 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4771 ext4_mark_inode_dirty(handle
, inode
);
4774 * In a multi-transaction truncate, we only make the final transaction
4778 ext4_handle_sync(handle
);
4781 * If this was a simple ftruncate(), and the file will remain alive
4782 * then we need to clear up the orphan record which we created above.
4783 * However, if this was a real unlink then we were called by
4784 * ext4_delete_inode(), and we allow that function to clean up the
4785 * orphan info for us.
4788 ext4_orphan_del(handle
, inode
);
4790 ext4_journal_stop(handle
);
4794 * ext4_get_inode_loc returns with an extra refcount against the inode's
4795 * underlying buffer_head on success. If 'in_mem' is true, we have all
4796 * data in memory that is needed to recreate the on-disk version of this
4799 static int __ext4_get_inode_loc(struct inode
*inode
,
4800 struct ext4_iloc
*iloc
, int in_mem
)
4802 struct ext4_group_desc
*gdp
;
4803 struct buffer_head
*bh
;
4804 struct super_block
*sb
= inode
->i_sb
;
4806 int inodes_per_block
, inode_offset
;
4809 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4812 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4813 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4818 * Figure out the offset within the block group inode table
4820 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4821 inode_offset
= ((inode
->i_ino
- 1) %
4822 EXT4_INODES_PER_GROUP(sb
));
4823 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4824 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4826 bh
= sb_getblk(sb
, block
);
4828 EXT4_ERROR_INODE_BLOCK(inode
, block
,
4829 "unable to read itable block");
4832 if (!buffer_uptodate(bh
)) {
4836 * If the buffer has the write error flag, we have failed
4837 * to write out another inode in the same block. In this
4838 * case, we don't have to read the block because we may
4839 * read the old inode data successfully.
4841 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4842 set_buffer_uptodate(bh
);
4844 if (buffer_uptodate(bh
)) {
4845 /* someone brought it uptodate while we waited */
4851 * If we have all information of the inode in memory and this
4852 * is the only valid inode in the block, we need not read the
4856 struct buffer_head
*bitmap_bh
;
4859 start
= inode_offset
& ~(inodes_per_block
- 1);
4861 /* Is the inode bitmap in cache? */
4862 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4867 * If the inode bitmap isn't in cache then the
4868 * optimisation may end up performing two reads instead
4869 * of one, so skip it.
4871 if (!buffer_uptodate(bitmap_bh
)) {
4875 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4876 if (i
== inode_offset
)
4878 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4882 if (i
== start
+ inodes_per_block
) {
4883 /* all other inodes are free, so skip I/O */
4884 memset(bh
->b_data
, 0, bh
->b_size
);
4885 set_buffer_uptodate(bh
);
4893 * If we need to do any I/O, try to pre-readahead extra
4894 * blocks from the inode table.
4896 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4897 ext4_fsblk_t b
, end
, table
;
4900 table
= ext4_inode_table(sb
, gdp
);
4901 /* s_inode_readahead_blks is always a power of 2 */
4902 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4905 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4906 num
= EXT4_INODES_PER_GROUP(sb
);
4907 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4908 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4909 num
-= ext4_itable_unused_count(sb
, gdp
);
4910 table
+= num
/ inodes_per_block
;
4914 sb_breadahead(sb
, b
++);
4918 * There are other valid inodes in the buffer, this inode
4919 * has in-inode xattrs, or we don't have this inode in memory.
4920 * Read the block from disk.
4923 bh
->b_end_io
= end_buffer_read_sync
;
4924 submit_bh(READ_META
, bh
);
4926 if (!buffer_uptodate(bh
)) {
4927 EXT4_ERROR_INODE_BLOCK(inode
, block
,
4928 "unable to read itable block");
4938 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4940 /* We have all inode data except xattrs in memory here. */
4941 return __ext4_get_inode_loc(inode
, iloc
,
4942 !ext4_test_inode_state(inode
, EXT4_STATE_XATTR
));
4945 void ext4_set_inode_flags(struct inode
*inode
)
4947 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4949 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4950 if (flags
& EXT4_SYNC_FL
)
4951 inode
->i_flags
|= S_SYNC
;
4952 if (flags
& EXT4_APPEND_FL
)
4953 inode
->i_flags
|= S_APPEND
;
4954 if (flags
& EXT4_IMMUTABLE_FL
)
4955 inode
->i_flags
|= S_IMMUTABLE
;
4956 if (flags
& EXT4_NOATIME_FL
)
4957 inode
->i_flags
|= S_NOATIME
;
4958 if (flags
& EXT4_DIRSYNC_FL
)
4959 inode
->i_flags
|= S_DIRSYNC
;
4962 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4963 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4965 unsigned int vfs_fl
;
4966 unsigned long old_fl
, new_fl
;
4969 vfs_fl
= ei
->vfs_inode
.i_flags
;
4970 old_fl
= ei
->i_flags
;
4971 new_fl
= old_fl
& ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4972 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|
4974 if (vfs_fl
& S_SYNC
)
4975 new_fl
|= EXT4_SYNC_FL
;
4976 if (vfs_fl
& S_APPEND
)
4977 new_fl
|= EXT4_APPEND_FL
;
4978 if (vfs_fl
& S_IMMUTABLE
)
4979 new_fl
|= EXT4_IMMUTABLE_FL
;
4980 if (vfs_fl
& S_NOATIME
)
4981 new_fl
|= EXT4_NOATIME_FL
;
4982 if (vfs_fl
& S_DIRSYNC
)
4983 new_fl
|= EXT4_DIRSYNC_FL
;
4984 } while (cmpxchg(&ei
->i_flags
, old_fl
, new_fl
) != old_fl
);
4987 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4988 struct ext4_inode_info
*ei
)
4991 struct inode
*inode
= &(ei
->vfs_inode
);
4992 struct super_block
*sb
= inode
->i_sb
;
4994 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4995 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4996 /* we are using combined 48 bit field */
4997 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4998 le32_to_cpu(raw_inode
->i_blocks_lo
);
4999 if (ext4_test_inode_flag(inode
, EXT4_INODE_HUGE_FILE
)) {
5000 /* i_blocks represent file system block size */
5001 return i_blocks
<< (inode
->i_blkbits
- 9);
5006 return le32_to_cpu(raw_inode
->i_blocks_lo
);
5010 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
5012 struct ext4_iloc iloc
;
5013 struct ext4_inode
*raw_inode
;
5014 struct ext4_inode_info
*ei
;
5015 struct inode
*inode
;
5016 journal_t
*journal
= EXT4_SB(sb
)->s_journal
;
5020 inode
= iget_locked(sb
, ino
);
5022 return ERR_PTR(-ENOMEM
);
5023 if (!(inode
->i_state
& I_NEW
))
5029 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
5032 raw_inode
= ext4_raw_inode(&iloc
);
5033 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
5034 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
5035 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
5036 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5037 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
5038 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
5040 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
5042 ei
->i_state_flags
= 0;
5043 ei
->i_dir_start_lookup
= 0;
5044 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
5045 /* We now have enough fields to check if the inode was active or not.
5046 * This is needed because nfsd might try to access dead inodes
5047 * the test is that same one that e2fsck uses
5048 * NeilBrown 1999oct15
5050 if (inode
->i_nlink
== 0) {
5051 if (inode
->i_mode
== 0 ||
5052 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
5053 /* this inode is deleted */
5057 /* The only unlinked inodes we let through here have
5058 * valid i_mode and are being read by the orphan
5059 * recovery code: that's fine, we're about to complete
5060 * the process of deleting those. */
5062 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
5063 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
5064 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
5065 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
5067 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
5068 inode
->i_size
= ext4_isize(raw_inode
);
5069 ei
->i_disksize
= inode
->i_size
;
5071 ei
->i_reserved_quota
= 0;
5073 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
5074 ei
->i_block_group
= iloc
.block_group
;
5075 ei
->i_last_alloc_group
= ~0;
5077 * NOTE! The in-memory inode i_data array is in little-endian order
5078 * even on big-endian machines: we do NOT byteswap the block numbers!
5080 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5081 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
5082 INIT_LIST_HEAD(&ei
->i_orphan
);
5085 * Set transaction id's of transactions that have to be committed
5086 * to finish f[data]sync. We set them to currently running transaction
5087 * as we cannot be sure that the inode or some of its metadata isn't
5088 * part of the transaction - the inode could have been reclaimed and
5089 * now it is reread from disk.
5092 transaction_t
*transaction
;
5095 read_lock(&journal
->j_state_lock
);
5096 if (journal
->j_running_transaction
)
5097 transaction
= journal
->j_running_transaction
;
5099 transaction
= journal
->j_committing_transaction
;
5101 tid
= transaction
->t_tid
;
5103 tid
= journal
->j_commit_sequence
;
5104 read_unlock(&journal
->j_state_lock
);
5105 ei
->i_sync_tid
= tid
;
5106 ei
->i_datasync_tid
= tid
;
5109 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
5110 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
5111 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
5112 EXT4_INODE_SIZE(inode
->i_sb
)) {
5116 if (ei
->i_extra_isize
== 0) {
5117 /* The extra space is currently unused. Use it. */
5118 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
5119 EXT4_GOOD_OLD_INODE_SIZE
;
5121 __le32
*magic
= (void *)raw_inode
+
5122 EXT4_GOOD_OLD_INODE_SIZE
+
5124 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
5125 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
5128 ei
->i_extra_isize
= 0;
5130 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
5131 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
5132 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
5133 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
5135 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
5136 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
5137 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5139 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
5143 if (ei
->i_file_acl
&&
5144 !ext4_data_block_valid(EXT4_SB(sb
), ei
->i_file_acl
, 1)) {
5145 EXT4_ERROR_INODE(inode
, "bad extended attribute block %llu",
5149 } else if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
5150 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
5151 (S_ISLNK(inode
->i_mode
) &&
5152 !ext4_inode_is_fast_symlink(inode
)))
5153 /* Validate extent which is part of inode */
5154 ret
= ext4_ext_check_inode(inode
);
5155 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
5156 (S_ISLNK(inode
->i_mode
) &&
5157 !ext4_inode_is_fast_symlink(inode
))) {
5158 /* Validate block references which are part of inode */
5159 ret
= ext4_check_inode_blockref(inode
);
5164 if (S_ISREG(inode
->i_mode
)) {
5165 inode
->i_op
= &ext4_file_inode_operations
;
5166 inode
->i_fop
= &ext4_file_operations
;
5167 ext4_set_aops(inode
);
5168 } else if (S_ISDIR(inode
->i_mode
)) {
5169 inode
->i_op
= &ext4_dir_inode_operations
;
5170 inode
->i_fop
= &ext4_dir_operations
;
5171 } else if (S_ISLNK(inode
->i_mode
)) {
5172 if (ext4_inode_is_fast_symlink(inode
)) {
5173 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
5174 nd_terminate_link(ei
->i_data
, inode
->i_size
,
5175 sizeof(ei
->i_data
) - 1);
5177 inode
->i_op
= &ext4_symlink_inode_operations
;
5178 ext4_set_aops(inode
);
5180 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
5181 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
5182 inode
->i_op
= &ext4_special_inode_operations
;
5183 if (raw_inode
->i_block
[0])
5184 init_special_inode(inode
, inode
->i_mode
,
5185 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
5187 init_special_inode(inode
, inode
->i_mode
,
5188 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
5191 EXT4_ERROR_INODE(inode
, "bogus i_mode (%o)", inode
->i_mode
);
5195 ext4_set_inode_flags(inode
);
5196 unlock_new_inode(inode
);
5202 return ERR_PTR(ret
);
5205 static int ext4_inode_blocks_set(handle_t
*handle
,
5206 struct ext4_inode
*raw_inode
,
5207 struct ext4_inode_info
*ei
)
5209 struct inode
*inode
= &(ei
->vfs_inode
);
5210 u64 i_blocks
= inode
->i_blocks
;
5211 struct super_block
*sb
= inode
->i_sb
;
5213 if (i_blocks
<= ~0U) {
5215 * i_blocks can be represnted in a 32 bit variable
5216 * as multiple of 512 bytes
5218 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5219 raw_inode
->i_blocks_high
= 0;
5220 ext4_clear_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
5223 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
5226 if (i_blocks
<= 0xffffffffffffULL
) {
5228 * i_blocks can be represented in a 48 bit variable
5229 * as multiple of 512 bytes
5231 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5232 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
5233 ext4_clear_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
5235 ext4_set_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
5236 /* i_block is stored in file system block size */
5237 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
5238 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5239 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
5245 * Post the struct inode info into an on-disk inode location in the
5246 * buffer-cache. This gobbles the caller's reference to the
5247 * buffer_head in the inode location struct.
5249 * The caller must have write access to iloc->bh.
5251 static int ext4_do_update_inode(handle_t
*handle
,
5252 struct inode
*inode
,
5253 struct ext4_iloc
*iloc
)
5255 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
5256 struct ext4_inode_info
*ei
= EXT4_I(inode
);
5257 struct buffer_head
*bh
= iloc
->bh
;
5258 int err
= 0, rc
, block
;
5260 /* For fields not not tracking in the in-memory inode,
5261 * initialise them to zero for new inodes. */
5262 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
))
5263 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
5265 ext4_get_inode_flags(ei
);
5266 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
5267 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5268 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
5269 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
5271 * Fix up interoperability with old kernels. Otherwise, old inodes get
5272 * re-used with the upper 16 bits of the uid/gid intact
5275 raw_inode
->i_uid_high
=
5276 cpu_to_le16(high_16_bits(inode
->i_uid
));
5277 raw_inode
->i_gid_high
=
5278 cpu_to_le16(high_16_bits(inode
->i_gid
));
5280 raw_inode
->i_uid_high
= 0;
5281 raw_inode
->i_gid_high
= 0;
5284 raw_inode
->i_uid_low
=
5285 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
5286 raw_inode
->i_gid_low
=
5287 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
5288 raw_inode
->i_uid_high
= 0;
5289 raw_inode
->i_gid_high
= 0;
5291 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
5293 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
5294 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
5295 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
5296 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
5298 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
5300 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
5301 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
);
5302 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
5303 cpu_to_le32(EXT4_OS_HURD
))
5304 raw_inode
->i_file_acl_high
=
5305 cpu_to_le16(ei
->i_file_acl
>> 32);
5306 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
5307 ext4_isize_set(raw_inode
, ei
->i_disksize
);
5308 if (ei
->i_disksize
> 0x7fffffffULL
) {
5309 struct super_block
*sb
= inode
->i_sb
;
5310 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
5311 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
5312 EXT4_SB(sb
)->s_es
->s_rev_level
==
5313 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
5314 /* If this is the first large file
5315 * created, add a flag to the superblock.
5317 err
= ext4_journal_get_write_access(handle
,
5318 EXT4_SB(sb
)->s_sbh
);
5321 ext4_update_dynamic_rev(sb
);
5322 EXT4_SET_RO_COMPAT_FEATURE(sb
,
5323 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
5325 ext4_handle_sync(handle
);
5326 err
= ext4_handle_dirty_metadata(handle
, NULL
,
5327 EXT4_SB(sb
)->s_sbh
);
5330 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
5331 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
5332 if (old_valid_dev(inode
->i_rdev
)) {
5333 raw_inode
->i_block
[0] =
5334 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
5335 raw_inode
->i_block
[1] = 0;
5337 raw_inode
->i_block
[0] = 0;
5338 raw_inode
->i_block
[1] =
5339 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
5340 raw_inode
->i_block
[2] = 0;
5343 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5344 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
5346 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
5347 if (ei
->i_extra_isize
) {
5348 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5349 raw_inode
->i_version_hi
=
5350 cpu_to_le32(inode
->i_version
>> 32);
5351 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
5354 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
5355 rc
= ext4_handle_dirty_metadata(handle
, NULL
, bh
);
5358 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
5360 ext4_update_inode_fsync_trans(handle
, inode
, 0);
5363 ext4_std_error(inode
->i_sb
, err
);
5368 * ext4_write_inode()
5370 * We are called from a few places:
5372 * - Within generic_file_write() for O_SYNC files.
5373 * Here, there will be no transaction running. We wait for any running
5374 * trasnaction to commit.
5376 * - Within sys_sync(), kupdate and such.
5377 * We wait on commit, if tol to.
5379 * - Within prune_icache() (PF_MEMALLOC == true)
5380 * Here we simply return. We can't afford to block kswapd on the
5383 * In all cases it is actually safe for us to return without doing anything,
5384 * because the inode has been copied into a raw inode buffer in
5385 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5388 * Note that we are absolutely dependent upon all inode dirtiers doing the
5389 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5390 * which we are interested.
5392 * It would be a bug for them to not do this. The code:
5394 * mark_inode_dirty(inode)
5396 * inode->i_size = expr;
5398 * is in error because a kswapd-driven write_inode() could occur while
5399 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5400 * will no longer be on the superblock's dirty inode list.
5402 int ext4_write_inode(struct inode
*inode
, struct writeback_control
*wbc
)
5406 if (current
->flags
& PF_MEMALLOC
)
5409 if (EXT4_SB(inode
->i_sb
)->s_journal
) {
5410 if (ext4_journal_current_handle()) {
5411 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5416 if (wbc
->sync_mode
!= WB_SYNC_ALL
)
5419 err
= ext4_force_commit(inode
->i_sb
);
5421 struct ext4_iloc iloc
;
5423 err
= __ext4_get_inode_loc(inode
, &iloc
, 0);
5426 if (wbc
->sync_mode
== WB_SYNC_ALL
)
5427 sync_dirty_buffer(iloc
.bh
);
5428 if (buffer_req(iloc
.bh
) && !buffer_uptodate(iloc
.bh
)) {
5429 EXT4_ERROR_INODE_BLOCK(inode
, iloc
.bh
->b_blocknr
,
5430 "IO error syncing inode");
5441 * Called from notify_change.
5443 * We want to trap VFS attempts to truncate the file as soon as
5444 * possible. In particular, we want to make sure that when the VFS
5445 * shrinks i_size, we put the inode on the orphan list and modify
5446 * i_disksize immediately, so that during the subsequent flushing of
5447 * dirty pages and freeing of disk blocks, we can guarantee that any
5448 * commit will leave the blocks being flushed in an unused state on
5449 * disk. (On recovery, the inode will get truncated and the blocks will
5450 * be freed, so we have a strong guarantee that no future commit will
5451 * leave these blocks visible to the user.)
5453 * Another thing we have to assure is that if we are in ordered mode
5454 * and inode is still attached to the committing transaction, we must
5455 * we start writeout of all the dirty pages which are being truncated.
5456 * This way we are sure that all the data written in the previous
5457 * transaction are already on disk (truncate waits for pages under
5460 * Called with inode->i_mutex down.
5462 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
5464 struct inode
*inode
= dentry
->d_inode
;
5466 const unsigned int ia_valid
= attr
->ia_valid
;
5468 error
= inode_change_ok(inode
, attr
);
5472 if (is_quota_modification(inode
, attr
))
5473 dquot_initialize(inode
);
5474 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
5475 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
5478 /* (user+group)*(old+new) structure, inode write (sb,
5479 * inode block, ? - but truncate inode update has it) */
5480 handle
= ext4_journal_start(inode
, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode
->i_sb
)+
5481 EXT4_MAXQUOTAS_DEL_BLOCKS(inode
->i_sb
))+3);
5482 if (IS_ERR(handle
)) {
5483 error
= PTR_ERR(handle
);
5486 error
= dquot_transfer(inode
, attr
);
5488 ext4_journal_stop(handle
);
5491 /* Update corresponding info in inode so that everything is in
5492 * one transaction */
5493 if (attr
->ia_valid
& ATTR_UID
)
5494 inode
->i_uid
= attr
->ia_uid
;
5495 if (attr
->ia_valid
& ATTR_GID
)
5496 inode
->i_gid
= attr
->ia_gid
;
5497 error
= ext4_mark_inode_dirty(handle
, inode
);
5498 ext4_journal_stop(handle
);
5501 if (attr
->ia_valid
& ATTR_SIZE
) {
5502 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))) {
5503 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5505 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
)
5510 if (S_ISREG(inode
->i_mode
) &&
5511 attr
->ia_valid
& ATTR_SIZE
&&
5512 (attr
->ia_size
< inode
->i_size
||
5513 (ext4_test_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
)))) {
5516 handle
= ext4_journal_start(inode
, 3);
5517 if (IS_ERR(handle
)) {
5518 error
= PTR_ERR(handle
);
5522 error
= ext4_orphan_add(handle
, inode
);
5523 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
5524 rc
= ext4_mark_inode_dirty(handle
, inode
);
5527 ext4_journal_stop(handle
);
5529 if (ext4_should_order_data(inode
)) {
5530 error
= ext4_begin_ordered_truncate(inode
,
5533 /* Do as much error cleanup as possible */
5534 handle
= ext4_journal_start(inode
, 3);
5535 if (IS_ERR(handle
)) {
5536 ext4_orphan_del(NULL
, inode
);
5539 ext4_orphan_del(handle
, inode
);
5540 ext4_journal_stop(handle
);
5544 /* ext4_truncate will clear the flag */
5545 if ((ext4_test_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
)))
5546 ext4_truncate(inode
);
5549 if ((attr
->ia_valid
& ATTR_SIZE
) &&
5550 attr
->ia_size
!= i_size_read(inode
))
5551 rc
= vmtruncate(inode
, attr
->ia_size
);
5554 setattr_copy(inode
, attr
);
5555 mark_inode_dirty(inode
);
5559 * If the call to ext4_truncate failed to get a transaction handle at
5560 * all, we need to clean up the in-core orphan list manually.
5563 ext4_orphan_del(NULL
, inode
);
5565 if (!rc
&& (ia_valid
& ATTR_MODE
))
5566 rc
= ext4_acl_chmod(inode
);
5569 ext4_std_error(inode
->i_sb
, error
);
5575 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
5578 struct inode
*inode
;
5579 unsigned long delalloc_blocks
;
5581 inode
= dentry
->d_inode
;
5582 generic_fillattr(inode
, stat
);
5585 * We can't update i_blocks if the block allocation is delayed
5586 * otherwise in the case of system crash before the real block
5587 * allocation is done, we will have i_blocks inconsistent with
5588 * on-disk file blocks.
5589 * We always keep i_blocks updated together with real
5590 * allocation. But to not confuse with user, stat
5591 * will return the blocks that include the delayed allocation
5592 * blocks for this file.
5594 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
5595 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
5596 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
5598 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
5602 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
5607 /* if nrblocks are contiguous */
5610 * With N contiguous data blocks, it need at most
5611 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5612 * 2 dindirect blocks
5615 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
5616 return indirects
+ 3;
5619 * if nrblocks are not contiguous, worse case, each block touch
5620 * a indirect block, and each indirect block touch a double indirect
5621 * block, plus a triple indirect block
5623 indirects
= nrblocks
* 2 + 1;
5627 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5629 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
5630 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
5631 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
5635 * Account for index blocks, block groups bitmaps and block group
5636 * descriptor blocks if modify datablocks and index blocks
5637 * worse case, the indexs blocks spread over different block groups
5639 * If datablocks are discontiguous, they are possible to spread over
5640 * different block groups too. If they are contiuguous, with flexbg,
5641 * they could still across block group boundary.
5643 * Also account for superblock, inode, quota and xattr blocks
5645 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5647 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
5653 * How many index blocks need to touch to modify nrblocks?
5654 * The "Chunk" flag indicating whether the nrblocks is
5655 * physically contiguous on disk
5657 * For Direct IO and fallocate, they calls get_block to allocate
5658 * one single extent at a time, so they could set the "Chunk" flag
5660 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
5665 * Now let's see how many group bitmaps and group descriptors need
5675 if (groups
> ngroups
)
5677 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
5678 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
5680 /* bitmaps and block group descriptor blocks */
5681 ret
+= groups
+ gdpblocks
;
5683 /* Blocks for super block, inode, quota and xattr blocks */
5684 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
5690 * Calulate the total number of credits to reserve to fit
5691 * the modification of a single pages into a single transaction,
5692 * which may include multiple chunks of block allocations.
5694 * This could be called via ext4_write_begin()
5696 * We need to consider the worse case, when
5697 * one new block per extent.
5699 int ext4_writepage_trans_blocks(struct inode
*inode
)
5701 int bpp
= ext4_journal_blocks_per_page(inode
);
5704 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
5706 /* Account for data blocks for journalled mode */
5707 if (ext4_should_journal_data(inode
))
5713 * Calculate the journal credits for a chunk of data modification.
5715 * This is called from DIO, fallocate or whoever calling
5716 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
5718 * journal buffers for data blocks are not included here, as DIO
5719 * and fallocate do no need to journal data buffers.
5721 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
5723 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
5727 * The caller must have previously called ext4_reserve_inode_write().
5728 * Give this, we know that the caller already has write access to iloc->bh.
5730 int ext4_mark_iloc_dirty(handle_t
*handle
,
5731 struct inode
*inode
, struct ext4_iloc
*iloc
)
5735 if (test_opt(inode
->i_sb
, I_VERSION
))
5736 inode_inc_iversion(inode
);
5738 /* the do_update_inode consumes one bh->b_count */
5741 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5742 err
= ext4_do_update_inode(handle
, inode
, iloc
);
5748 * On success, We end up with an outstanding reference count against
5749 * iloc->bh. This _must_ be cleaned up later.
5753 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
5754 struct ext4_iloc
*iloc
)
5758 err
= ext4_get_inode_loc(inode
, iloc
);
5760 BUFFER_TRACE(iloc
->bh
, "get_write_access");
5761 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
5767 ext4_std_error(inode
->i_sb
, err
);
5772 * Expand an inode by new_extra_isize bytes.
5773 * Returns 0 on success or negative error number on failure.
5775 static int ext4_expand_extra_isize(struct inode
*inode
,
5776 unsigned int new_extra_isize
,
5777 struct ext4_iloc iloc
,
5780 struct ext4_inode
*raw_inode
;
5781 struct ext4_xattr_ibody_header
*header
;
5783 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
5786 raw_inode
= ext4_raw_inode(&iloc
);
5788 header
= IHDR(inode
, raw_inode
);
5790 /* No extended attributes present */
5791 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
) ||
5792 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
5793 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5795 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5799 /* try to expand with EAs present */
5800 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5805 * What we do here is to mark the in-core inode as clean with respect to inode
5806 * dirtiness (it may still be data-dirty).
5807 * This means that the in-core inode may be reaped by prune_icache
5808 * without having to perform any I/O. This is a very good thing,
5809 * because *any* task may call prune_icache - even ones which
5810 * have a transaction open against a different journal.
5812 * Is this cheating? Not really. Sure, we haven't written the
5813 * inode out, but prune_icache isn't a user-visible syncing function.
5814 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5815 * we start and wait on commits.
5817 * Is this efficient/effective? Well, we're being nice to the system
5818 * by cleaning up our inodes proactively so they can be reaped
5819 * without I/O. But we are potentially leaving up to five seconds'
5820 * worth of inodes floating about which prune_icache wants us to
5821 * write out. One way to fix that would be to get prune_icache()
5822 * to do a write_super() to free up some memory. It has the desired
5825 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5827 struct ext4_iloc iloc
;
5828 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5829 static unsigned int mnt_count
;
5833 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5834 if (ext4_handle_valid(handle
) &&
5835 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5836 !ext4_test_inode_state(inode
, EXT4_STATE_NO_EXPAND
)) {
5838 * We need extra buffer credits since we may write into EA block
5839 * with this same handle. If journal_extend fails, then it will
5840 * only result in a minor loss of functionality for that inode.
5841 * If this is felt to be critical, then e2fsck should be run to
5842 * force a large enough s_min_extra_isize.
5844 if ((jbd2_journal_extend(handle
,
5845 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5846 ret
= ext4_expand_extra_isize(inode
,
5847 sbi
->s_want_extra_isize
,
5850 ext4_set_inode_state(inode
,
5851 EXT4_STATE_NO_EXPAND
);
5853 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5854 ext4_warning(inode
->i_sb
,
5855 "Unable to expand inode %lu. Delete"
5856 " some EAs or run e2fsck.",
5859 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5865 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5870 * ext4_dirty_inode() is called from __mark_inode_dirty()
5872 * We're really interested in the case where a file is being extended.
5873 * i_size has been changed by generic_commit_write() and we thus need
5874 * to include the updated inode in the current transaction.
5876 * Also, dquot_alloc_block() will always dirty the inode when blocks
5877 * are allocated to the file.
5879 * If the inode is marked synchronous, we don't honour that here - doing
5880 * so would cause a commit on atime updates, which we don't bother doing.
5881 * We handle synchronous inodes at the highest possible level.
5883 void ext4_dirty_inode(struct inode
*inode
)
5887 handle
= ext4_journal_start(inode
, 2);
5891 ext4_mark_inode_dirty(handle
, inode
);
5893 ext4_journal_stop(handle
);
5900 * Bind an inode's backing buffer_head into this transaction, to prevent
5901 * it from being flushed to disk early. Unlike
5902 * ext4_reserve_inode_write, this leaves behind no bh reference and
5903 * returns no iloc structure, so the caller needs to repeat the iloc
5904 * lookup to mark the inode dirty later.
5906 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5908 struct ext4_iloc iloc
;
5912 err
= ext4_get_inode_loc(inode
, &iloc
);
5914 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5915 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5917 err
= ext4_handle_dirty_metadata(handle
,
5923 ext4_std_error(inode
->i_sb
, err
);
5928 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5935 * We have to be very careful here: changing a data block's
5936 * journaling status dynamically is dangerous. If we write a
5937 * data block to the journal, change the status and then delete
5938 * that block, we risk forgetting to revoke the old log record
5939 * from the journal and so a subsequent replay can corrupt data.
5940 * So, first we make sure that the journal is empty and that
5941 * nobody is changing anything.
5944 journal
= EXT4_JOURNAL(inode
);
5947 if (is_journal_aborted(journal
))
5950 jbd2_journal_lock_updates(journal
);
5951 jbd2_journal_flush(journal
);
5954 * OK, there are no updates running now, and all cached data is
5955 * synced to disk. We are now in a completely consistent state
5956 * which doesn't have anything in the journal, and we know that
5957 * no filesystem updates are running, so it is safe to modify
5958 * the inode's in-core data-journaling state flag now.
5962 ext4_set_inode_flag(inode
, EXT4_INODE_JOURNAL_DATA
);
5964 ext4_clear_inode_flag(inode
, EXT4_INODE_JOURNAL_DATA
);
5965 ext4_set_aops(inode
);
5967 jbd2_journal_unlock_updates(journal
);
5969 /* Finally we can mark the inode as dirty. */
5971 handle
= ext4_journal_start(inode
, 1);
5973 return PTR_ERR(handle
);
5975 err
= ext4_mark_inode_dirty(handle
, inode
);
5976 ext4_handle_sync(handle
);
5977 ext4_journal_stop(handle
);
5978 ext4_std_error(inode
->i_sb
, err
);
5983 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5985 return !buffer_mapped(bh
);
5988 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5990 struct page
*page
= vmf
->page
;
5995 struct file
*file
= vma
->vm_file
;
5996 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5997 struct address_space
*mapping
= inode
->i_mapping
;
6000 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
6001 * get i_mutex because we are already holding mmap_sem.
6003 down_read(&inode
->i_alloc_sem
);
6004 size
= i_size_read(inode
);
6005 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
6006 || !PageUptodate(page
)) {
6007 /* page got truncated from under us? */
6011 if (PageMappedToDisk(page
))
6014 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
6015 len
= size
& ~PAGE_CACHE_MASK
;
6017 len
= PAGE_CACHE_SIZE
;
6021 * return if we have all the buffers mapped. This avoid
6022 * the need to call write_begin/write_end which does a
6023 * journal_start/journal_stop which can block and take
6026 if (page_has_buffers(page
)) {
6027 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
6028 ext4_bh_unmapped
)) {
6035 * OK, we need to fill the hole... Do write_begin write_end
6036 * to do block allocation/reservation.We are not holding
6037 * inode.i__mutex here. That allow * parallel write_begin,
6038 * write_end call. lock_page prevent this from happening
6039 * on the same page though
6041 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
6042 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
6045 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
6046 len
, len
, page
, fsdata
);
6052 ret
= VM_FAULT_SIGBUS
;
6053 up_read(&inode
->i_alloc_sem
);