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_delete_inode(struct inode
*inode
)
175 if (!is_bad_inode(inode
))
176 dquot_initialize(inode
);
178 if (ext4_should_order_data(inode
))
179 ext4_begin_ordered_truncate(inode
, 0);
180 truncate_inode_pages(&inode
->i_data
, 0);
182 if (is_bad_inode(inode
))
185 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
186 if (IS_ERR(handle
)) {
187 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
189 * If we're going to skip the normal cleanup, we still need to
190 * make sure that the in-core orphan linked list is properly
193 ext4_orphan_del(NULL
, inode
);
198 ext4_handle_sync(handle
);
200 err
= ext4_mark_inode_dirty(handle
, inode
);
202 ext4_warning(inode
->i_sb
,
203 "couldn't mark inode dirty (err %d)", err
);
207 ext4_truncate(inode
);
210 * ext4_ext_truncate() doesn't reserve any slop when it
211 * restarts journal transactions; therefore there may not be
212 * enough credits left in the handle to remove the inode from
213 * the orphan list and set the dtime field.
215 if (!ext4_handle_has_enough_credits(handle
, 3)) {
216 err
= ext4_journal_extend(handle
, 3);
218 err
= ext4_journal_restart(handle
, 3);
220 ext4_warning(inode
->i_sb
,
221 "couldn't extend journal (err %d)", err
);
223 ext4_journal_stop(handle
);
229 * Kill off the orphan record which ext4_truncate created.
230 * AKPM: I think this can be inside the above `if'.
231 * Note that ext4_orphan_del() has to be able to cope with the
232 * deletion of a non-existent orphan - this is because we don't
233 * know if ext4_truncate() actually created an orphan record.
234 * (Well, we could do this if we need to, but heck - it works)
236 ext4_orphan_del(handle
, inode
);
237 EXT4_I(inode
)->i_dtime
= get_seconds();
240 * One subtle ordering requirement: if anything has gone wrong
241 * (transaction abort, IO errors, whatever), then we can still
242 * do these next steps (the fs will already have been marked as
243 * having errors), but we can't free the inode if the mark_dirty
246 if (ext4_mark_inode_dirty(handle
, inode
))
247 /* If that failed, just do the required in-core inode clear. */
250 ext4_free_inode(handle
, inode
);
251 ext4_journal_stop(handle
);
254 clear_inode(inode
); /* We must guarantee clearing of inode... */
260 struct buffer_head
*bh
;
263 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
265 p
->key
= *(p
->p
= v
);
270 * ext4_block_to_path - parse the block number into array of offsets
271 * @inode: inode in question (we are only interested in its superblock)
272 * @i_block: block number to be parsed
273 * @offsets: array to store the offsets in
274 * @boundary: set this non-zero if the referred-to block is likely to be
275 * followed (on disk) by an indirect block.
277 * To store the locations of file's data ext4 uses a data structure common
278 * for UNIX filesystems - tree of pointers anchored in the inode, with
279 * data blocks at leaves and indirect blocks in intermediate nodes.
280 * This function translates the block number into path in that tree -
281 * return value is the path length and @offsets[n] is the offset of
282 * pointer to (n+1)th node in the nth one. If @block is out of range
283 * (negative or too large) warning is printed and zero returned.
285 * Note: function doesn't find node addresses, so no IO is needed. All
286 * we need to know is the capacity of indirect blocks (taken from the
291 * Portability note: the last comparison (check that we fit into triple
292 * indirect block) is spelled differently, because otherwise on an
293 * architecture with 32-bit longs and 8Kb pages we might get into trouble
294 * if our filesystem had 8Kb blocks. We might use long long, but that would
295 * kill us on x86. Oh, well, at least the sign propagation does not matter -
296 * i_block would have to be negative in the very beginning, so we would not
300 static int ext4_block_to_path(struct inode
*inode
,
302 ext4_lblk_t offsets
[4], int *boundary
)
304 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
305 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
306 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
307 indirect_blocks
= ptrs
,
308 double_blocks
= (1 << (ptrs_bits
* 2));
312 if (i_block
< direct_blocks
) {
313 offsets
[n
++] = i_block
;
314 final
= direct_blocks
;
315 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
316 offsets
[n
++] = EXT4_IND_BLOCK
;
317 offsets
[n
++] = i_block
;
319 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
320 offsets
[n
++] = EXT4_DIND_BLOCK
;
321 offsets
[n
++] = i_block
>> ptrs_bits
;
322 offsets
[n
++] = i_block
& (ptrs
- 1);
324 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
325 offsets
[n
++] = EXT4_TIND_BLOCK
;
326 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
327 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
328 offsets
[n
++] = i_block
& (ptrs
- 1);
331 ext4_warning(inode
->i_sb
, "block %lu > max in inode %lu",
332 i_block
+ direct_blocks
+
333 indirect_blocks
+ double_blocks
, inode
->i_ino
);
336 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
340 static int __ext4_check_blockref(const char *function
, unsigned int line
,
342 __le32
*p
, unsigned int max
)
344 struct ext4_super_block
*es
= EXT4_SB(inode
->i_sb
)->s_es
;
348 while (bref
< p
+max
) {
349 blk
= le32_to_cpu(*bref
++);
351 unlikely(!ext4_data_block_valid(EXT4_SB(inode
->i_sb
),
353 es
->s_last_error_block
= cpu_to_le64(blk
);
354 ext4_error_inode(inode
, function
, line
, blk
,
363 #define ext4_check_indirect_blockref(inode, bh) \
364 __ext4_check_blockref(__func__, __LINE__, inode, \
365 (__le32 *)(bh)->b_data, \
366 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
368 #define ext4_check_inode_blockref(inode) \
369 __ext4_check_blockref(__func__, __LINE__, inode, \
370 EXT4_I(inode)->i_data, \
374 * ext4_get_branch - read the chain of indirect blocks leading to data
375 * @inode: inode in question
376 * @depth: depth of the chain (1 - direct pointer, etc.)
377 * @offsets: offsets of pointers in inode/indirect blocks
378 * @chain: place to store the result
379 * @err: here we store the error value
381 * Function fills the array of triples <key, p, bh> and returns %NULL
382 * if everything went OK or the pointer to the last filled triple
383 * (incomplete one) otherwise. Upon the return chain[i].key contains
384 * the number of (i+1)-th block in the chain (as it is stored in memory,
385 * i.e. little-endian 32-bit), chain[i].p contains the address of that
386 * number (it points into struct inode for i==0 and into the bh->b_data
387 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
388 * block for i>0 and NULL for i==0. In other words, it holds the block
389 * numbers of the chain, addresses they were taken from (and where we can
390 * verify that chain did not change) and buffer_heads hosting these
393 * Function stops when it stumbles upon zero pointer (absent block)
394 * (pointer to last triple returned, *@err == 0)
395 * or when it gets an IO error reading an indirect block
396 * (ditto, *@err == -EIO)
397 * or when it reads all @depth-1 indirect blocks successfully and finds
398 * the whole chain, all way to the data (returns %NULL, *err == 0).
400 * Need to be called with
401 * down_read(&EXT4_I(inode)->i_data_sem)
403 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
404 ext4_lblk_t
*offsets
,
405 Indirect chain
[4], int *err
)
407 struct super_block
*sb
= inode
->i_sb
;
409 struct buffer_head
*bh
;
412 /* i_data is not going away, no lock needed */
413 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
417 bh
= sb_getblk(sb
, le32_to_cpu(p
->key
));
421 if (!bh_uptodate_or_lock(bh
)) {
422 if (bh_submit_read(bh
) < 0) {
426 /* validate block references */
427 if (ext4_check_indirect_blockref(inode
, bh
)) {
433 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
447 * ext4_find_near - find a place for allocation with sufficient locality
449 * @ind: descriptor of indirect block.
451 * This function returns the preferred place for block allocation.
452 * It is used when heuristic for sequential allocation fails.
454 * + if there is a block to the left of our position - allocate near it.
455 * + if pointer will live in indirect block - allocate near that block.
456 * + if pointer will live in inode - allocate in the same
459 * In the latter case we colour the starting block by the callers PID to
460 * prevent it from clashing with concurrent allocations for a different inode
461 * in the same block group. The PID is used here so that functionally related
462 * files will be close-by on-disk.
464 * Caller must make sure that @ind is valid and will stay that way.
466 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
468 struct ext4_inode_info
*ei
= EXT4_I(inode
);
469 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
471 ext4_fsblk_t bg_start
;
472 ext4_fsblk_t last_block
;
473 ext4_grpblk_t colour
;
474 ext4_group_t block_group
;
475 int flex_size
= ext4_flex_bg_size(EXT4_SB(inode
->i_sb
));
477 /* Try to find previous block */
478 for (p
= ind
->p
- 1; p
>= start
; p
--) {
480 return le32_to_cpu(*p
);
483 /* No such thing, so let's try location of indirect block */
485 return ind
->bh
->b_blocknr
;
488 * It is going to be referred to from the inode itself? OK, just put it
489 * into the same cylinder group then.
491 block_group
= ei
->i_block_group
;
492 if (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) {
493 block_group
&= ~(flex_size
-1);
494 if (S_ISREG(inode
->i_mode
))
497 bg_start
= ext4_group_first_block_no(inode
->i_sb
, block_group
);
498 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
501 * If we are doing delayed allocation, we don't need take
502 * colour into account.
504 if (test_opt(inode
->i_sb
, DELALLOC
))
507 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
508 colour
= (current
->pid
% 16) *
509 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
511 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
512 return bg_start
+ colour
;
516 * ext4_find_goal - find a preferred place for allocation.
518 * @block: block we want
519 * @partial: pointer to the last triple within a chain
521 * Normally this function find the preferred place for block allocation,
523 * Because this is only used for non-extent files, we limit the block nr
526 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
532 * XXX need to get goal block from mballoc's data structures
535 goal
= ext4_find_near(inode
, partial
);
536 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
541 * ext4_blks_to_allocate: Look up the block map and count the number
542 * of direct blocks need to be allocated for the given branch.
544 * @branch: chain of indirect blocks
545 * @k: number of blocks need for indirect blocks
546 * @blks: number of data blocks to be mapped.
547 * @blocks_to_boundary: the offset in the indirect block
549 * return the total number of blocks to be allocate, including the
550 * direct and indirect blocks.
552 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned int blks
,
553 int blocks_to_boundary
)
555 unsigned int count
= 0;
558 * Simple case, [t,d]Indirect block(s) has not allocated yet
559 * then it's clear blocks on that path have not allocated
562 /* right now we don't handle cross boundary allocation */
563 if (blks
< blocks_to_boundary
+ 1)
566 count
+= blocks_to_boundary
+ 1;
571 while (count
< blks
&& count
<= blocks_to_boundary
&&
572 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
579 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
580 * @indirect_blks: the number of blocks need to allocate for indirect
583 * @new_blocks: on return it will store the new block numbers for
584 * the indirect blocks(if needed) and the first direct block,
585 * @blks: on return it will store the total number of allocated
588 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
589 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
590 int indirect_blks
, int blks
,
591 ext4_fsblk_t new_blocks
[4], int *err
)
593 struct ext4_allocation_request ar
;
595 unsigned long count
= 0, blk_allocated
= 0;
597 ext4_fsblk_t current_block
= 0;
601 * Here we try to allocate the requested multiple blocks at once,
602 * on a best-effort basis.
603 * To build a branch, we should allocate blocks for
604 * the indirect blocks(if not allocated yet), and at least
605 * the first direct block of this branch. That's the
606 * minimum number of blocks need to allocate(required)
608 /* first we try to allocate the indirect blocks */
609 target
= indirect_blks
;
612 /* allocating blocks for indirect blocks and direct blocks */
613 current_block
= ext4_new_meta_blocks(handle
, inode
,
618 if (unlikely(current_block
+ count
> EXT4_MAX_BLOCK_FILE_PHYS
)) {
619 EXT4_ERROR_INODE(inode
,
620 "current_block %llu + count %lu > %d!",
621 current_block
, count
,
622 EXT4_MAX_BLOCK_FILE_PHYS
);
628 /* allocate blocks for indirect blocks */
629 while (index
< indirect_blks
&& count
) {
630 new_blocks
[index
++] = current_block
++;
635 * save the new block number
636 * for the first direct block
638 new_blocks
[index
] = current_block
;
639 printk(KERN_INFO
"%s returned more blocks than "
640 "requested\n", __func__
);
646 target
= blks
- count
;
647 blk_allocated
= count
;
650 /* Now allocate data blocks */
651 memset(&ar
, 0, sizeof(ar
));
656 if (S_ISREG(inode
->i_mode
))
657 /* enable in-core preallocation only for regular files */
658 ar
.flags
= EXT4_MB_HINT_DATA
;
660 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
661 if (unlikely(current_block
+ ar
.len
> EXT4_MAX_BLOCK_FILE_PHYS
)) {
662 EXT4_ERROR_INODE(inode
,
663 "current_block %llu + ar.len %d > %d!",
664 current_block
, ar
.len
,
665 EXT4_MAX_BLOCK_FILE_PHYS
);
670 if (*err
&& (target
== blks
)) {
672 * if the allocation failed and we didn't allocate
678 if (target
== blks
) {
680 * save the new block number
681 * for the first direct block
683 new_blocks
[index
] = current_block
;
685 blk_allocated
+= ar
.len
;
688 /* total number of blocks allocated for direct blocks */
693 for (i
= 0; i
< index
; i
++)
694 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1, 0);
699 * ext4_alloc_branch - allocate and set up a chain of blocks.
701 * @indirect_blks: number of allocated indirect blocks
702 * @blks: number of allocated direct blocks
703 * @offsets: offsets (in the blocks) to store the pointers to next.
704 * @branch: place to store the chain in.
706 * This function allocates blocks, zeroes out all but the last one,
707 * links them into chain and (if we are synchronous) writes them to disk.
708 * In other words, it prepares a branch that can be spliced onto the
709 * inode. It stores the information about that chain in the branch[], in
710 * the same format as ext4_get_branch() would do. We are calling it after
711 * we had read the existing part of chain and partial points to the last
712 * triple of that (one with zero ->key). Upon the exit we have the same
713 * picture as after the successful ext4_get_block(), except that in one
714 * place chain is disconnected - *branch->p is still zero (we did not
715 * set the last link), but branch->key contains the number that should
716 * be placed into *branch->p to fill that gap.
718 * If allocation fails we free all blocks we've allocated (and forget
719 * their buffer_heads) and return the error value the from failed
720 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
721 * as described above and return 0.
723 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
724 ext4_lblk_t iblock
, int indirect_blks
,
725 int *blks
, ext4_fsblk_t goal
,
726 ext4_lblk_t
*offsets
, Indirect
*branch
)
728 int blocksize
= inode
->i_sb
->s_blocksize
;
731 struct buffer_head
*bh
;
733 ext4_fsblk_t new_blocks
[4];
734 ext4_fsblk_t current_block
;
736 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
737 *blks
, new_blocks
, &err
);
741 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
743 * metadata blocks and data blocks are allocated.
745 for (n
= 1; n
<= indirect_blks
; n
++) {
747 * Get buffer_head for parent block, zero it out
748 * and set the pointer to new one, then send
751 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
754 BUFFER_TRACE(bh
, "call get_create_access");
755 err
= ext4_journal_get_create_access(handle
, bh
);
757 /* Don't brelse(bh) here; it's done in
758 * ext4_journal_forget() below */
763 memset(bh
->b_data
, 0, blocksize
);
764 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
765 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
766 *branch
[n
].p
= branch
[n
].key
;
767 if (n
== indirect_blks
) {
768 current_block
= new_blocks
[n
];
770 * End of chain, update the last new metablock of
771 * the chain to point to the new allocated
772 * data blocks numbers
774 for (i
= 1; i
< num
; i
++)
775 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
777 BUFFER_TRACE(bh
, "marking uptodate");
778 set_buffer_uptodate(bh
);
781 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
782 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
789 /* Allocation failed, free what we already allocated */
790 ext4_free_blocks(handle
, inode
, 0, new_blocks
[0], 1, 0);
791 for (i
= 1; i
<= n
; i
++) {
793 * branch[i].bh is newly allocated, so there is no
794 * need to revoke the block, which is why we don't
795 * need to set EXT4_FREE_BLOCKS_METADATA.
797 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1,
798 EXT4_FREE_BLOCKS_FORGET
);
800 for (i
= n
+1; i
< indirect_blks
; i
++)
801 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1, 0);
803 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], num
, 0);
809 * ext4_splice_branch - splice the allocated branch onto inode.
811 * @block: (logical) number of block we are adding
812 * @chain: chain of indirect blocks (with a missing link - see
814 * @where: location of missing link
815 * @num: number of indirect blocks we are adding
816 * @blks: number of direct blocks we are adding
818 * This function fills the missing link and does all housekeeping needed in
819 * inode (->i_blocks, etc.). In case of success we end up with the full
820 * chain to new block and return 0.
822 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
823 ext4_lblk_t block
, Indirect
*where
, int num
,
828 ext4_fsblk_t current_block
;
831 * If we're splicing into a [td]indirect block (as opposed to the
832 * inode) then we need to get write access to the [td]indirect block
836 BUFFER_TRACE(where
->bh
, "get_write_access");
837 err
= ext4_journal_get_write_access(handle
, where
->bh
);
843 *where
->p
= where
->key
;
846 * Update the host buffer_head or inode to point to more just allocated
847 * direct blocks blocks
849 if (num
== 0 && blks
> 1) {
850 current_block
= le32_to_cpu(where
->key
) + 1;
851 for (i
= 1; i
< blks
; i
++)
852 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
855 /* We are done with atomic stuff, now do the rest of housekeeping */
856 /* had we spliced it onto indirect block? */
859 * If we spliced it onto an indirect block, we haven't
860 * altered the inode. Note however that if it is being spliced
861 * onto an indirect block at the very end of the file (the
862 * file is growing) then we *will* alter the inode to reflect
863 * the new i_size. But that is not done here - it is done in
864 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
866 jbd_debug(5, "splicing indirect only\n");
867 BUFFER_TRACE(where
->bh
, "call ext4_handle_dirty_metadata");
868 err
= ext4_handle_dirty_metadata(handle
, inode
, where
->bh
);
873 * OK, we spliced it into the inode itself on a direct block.
875 ext4_mark_inode_dirty(handle
, inode
);
876 jbd_debug(5, "splicing direct\n");
881 for (i
= 1; i
<= num
; i
++) {
883 * branch[i].bh is newly allocated, so there is no
884 * need to revoke the block, which is why we don't
885 * need to set EXT4_FREE_BLOCKS_METADATA.
887 ext4_free_blocks(handle
, inode
, where
[i
].bh
, 0, 1,
888 EXT4_FREE_BLOCKS_FORGET
);
890 ext4_free_blocks(handle
, inode
, 0, le32_to_cpu(where
[num
].key
),
897 * The ext4_ind_map_blocks() function handles non-extents inodes
898 * (i.e., using the traditional indirect/double-indirect i_blocks
899 * scheme) for ext4_map_blocks().
901 * Allocation strategy is simple: if we have to allocate something, we will
902 * have to go the whole way to leaf. So let's do it before attaching anything
903 * to tree, set linkage between the newborn blocks, write them if sync is
904 * required, recheck the path, free and repeat if check fails, otherwise
905 * set the last missing link (that will protect us from any truncate-generated
906 * removals - all blocks on the path are immune now) and possibly force the
907 * write on the parent block.
908 * That has a nice additional property: no special recovery from the failed
909 * allocations is needed - we simply release blocks and do not touch anything
910 * reachable from inode.
912 * `handle' can be NULL if create == 0.
914 * return > 0, # of blocks mapped or allocated.
915 * return = 0, if plain lookup failed.
916 * return < 0, error case.
918 * The ext4_ind_get_blocks() function should be called with
919 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
920 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
921 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
924 static int ext4_ind_map_blocks(handle_t
*handle
, struct inode
*inode
,
925 struct ext4_map_blocks
*map
,
929 ext4_lblk_t offsets
[4];
934 int blocks_to_boundary
= 0;
937 ext4_fsblk_t first_block
= 0;
939 J_ASSERT(!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)));
940 J_ASSERT(handle
!= NULL
|| (flags
& EXT4_GET_BLOCKS_CREATE
) == 0);
941 depth
= ext4_block_to_path(inode
, map
->m_lblk
, offsets
,
942 &blocks_to_boundary
);
947 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
949 /* Simplest case - block found, no allocation needed */
951 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
954 while (count
< map
->m_len
&& count
<= blocks_to_boundary
) {
957 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
959 if (blk
== first_block
+ count
)
967 /* Next simple case - plain lookup or failed read of indirect block */
968 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0 || err
== -EIO
)
972 * Okay, we need to do block allocation.
974 goal
= ext4_find_goal(inode
, map
->m_lblk
, partial
);
976 /* the number of blocks need to allocate for [d,t]indirect blocks */
977 indirect_blks
= (chain
+ depth
) - partial
- 1;
980 * Next look up the indirect map to count the totoal number of
981 * direct blocks to allocate for this branch.
983 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
984 map
->m_len
, blocks_to_boundary
);
986 * Block out ext4_truncate while we alter the tree
988 err
= ext4_alloc_branch(handle
, inode
, map
->m_lblk
, indirect_blks
,
990 offsets
+ (partial
- chain
), partial
);
993 * The ext4_splice_branch call will free and forget any buffers
994 * on the new chain if there is a failure, but that risks using
995 * up transaction credits, especially for bitmaps where the
996 * credits cannot be returned. Can we handle this somehow? We
997 * may need to return -EAGAIN upwards in the worst case. --sct
1000 err
= ext4_splice_branch(handle
, inode
, map
->m_lblk
,
1001 partial
, indirect_blks
, count
);
1005 map
->m_flags
|= EXT4_MAP_NEW
;
1007 ext4_update_inode_fsync_trans(handle
, inode
, 1);
1009 map
->m_flags
|= EXT4_MAP_MAPPED
;
1010 map
->m_pblk
= le32_to_cpu(chain
[depth
-1].key
);
1012 if (count
> blocks_to_boundary
)
1013 map
->m_flags
|= EXT4_MAP_BOUNDARY
;
1015 /* Clean up and exit */
1016 partial
= chain
+ depth
- 1; /* the whole chain */
1018 while (partial
> chain
) {
1019 BUFFER_TRACE(partial
->bh
, "call brelse");
1020 brelse(partial
->bh
);
1028 qsize_t
*ext4_get_reserved_space(struct inode
*inode
)
1030 return &EXT4_I(inode
)->i_reserved_quota
;
1035 * Calculate the number of metadata blocks need to reserve
1036 * to allocate a new block at @lblocks for non extent file based file
1038 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
,
1041 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1042 sector_t dind_mask
= ~((sector_t
)EXT4_ADDR_PER_BLOCK(inode
->i_sb
) - 1);
1045 if (lblock
< EXT4_NDIR_BLOCKS
)
1048 lblock
-= EXT4_NDIR_BLOCKS
;
1050 if (ei
->i_da_metadata_calc_len
&&
1051 (lblock
& dind_mask
) == ei
->i_da_metadata_calc_last_lblock
) {
1052 ei
->i_da_metadata_calc_len
++;
1055 ei
->i_da_metadata_calc_last_lblock
= lblock
& dind_mask
;
1056 ei
->i_da_metadata_calc_len
= 1;
1057 blk_bits
= order_base_2(lblock
);
1058 return (blk_bits
/ EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
)) + 1;
1062 * Calculate the number of metadata blocks need to reserve
1063 * to allocate a block located at @lblock
1065 static int ext4_calc_metadata_amount(struct inode
*inode
, sector_t lblock
)
1067 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
1068 return ext4_ext_calc_metadata_amount(inode
, lblock
);
1070 return ext4_indirect_calc_metadata_amount(inode
, lblock
);
1074 * Called with i_data_sem down, which is important since we can call
1075 * ext4_discard_preallocations() from here.
1077 void ext4_da_update_reserve_space(struct inode
*inode
,
1078 int used
, int quota_claim
)
1080 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1081 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1083 spin_lock(&ei
->i_block_reservation_lock
);
1084 trace_ext4_da_update_reserve_space(inode
, used
);
1085 if (unlikely(used
> ei
->i_reserved_data_blocks
)) {
1086 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "%s: ino %lu, used %d "
1087 "with only %d reserved data blocks\n",
1088 __func__
, inode
->i_ino
, used
,
1089 ei
->i_reserved_data_blocks
);
1091 used
= ei
->i_reserved_data_blocks
;
1094 /* Update per-inode reservations */
1095 ei
->i_reserved_data_blocks
-= used
;
1096 ei
->i_reserved_meta_blocks
-= ei
->i_allocated_meta_blocks
;
1097 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
1098 used
+ ei
->i_allocated_meta_blocks
);
1099 ei
->i_allocated_meta_blocks
= 0;
1101 if (ei
->i_reserved_data_blocks
== 0) {
1103 * We can release all of the reserved metadata blocks
1104 * only when we have written all of the delayed
1105 * allocation blocks.
1107 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
1108 ei
->i_reserved_meta_blocks
);
1109 ei
->i_reserved_meta_blocks
= 0;
1110 ei
->i_da_metadata_calc_len
= 0;
1112 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1114 /* Update quota subsystem for data blocks */
1116 dquot_claim_block(inode
, used
);
1119 * We did fallocate with an offset that is already delayed
1120 * allocated. So on delayed allocated writeback we should
1121 * not re-claim the quota for fallocated blocks.
1123 dquot_release_reservation_block(inode
, used
);
1127 * If we have done all the pending block allocations and if
1128 * there aren't any writers on the inode, we can discard the
1129 * inode's preallocations.
1131 if ((ei
->i_reserved_data_blocks
== 0) &&
1132 (atomic_read(&inode
->i_writecount
) == 0))
1133 ext4_discard_preallocations(inode
);
1136 static int __check_block_validity(struct inode
*inode
, const char *func
,
1138 struct ext4_map_blocks
*map
)
1140 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), map
->m_pblk
,
1142 ext4_error_inode(inode
, func
, line
, map
->m_pblk
,
1143 "lblock %lu mapped to illegal pblock "
1144 "(length %d)", (unsigned long) map
->m_lblk
,
1151 #define check_block_validity(inode, map) \
1152 __check_block_validity((inode), __func__, __LINE__, (map))
1155 * Return the number of contiguous dirty pages in a given inode
1156 * starting at page frame idx.
1158 static pgoff_t
ext4_num_dirty_pages(struct inode
*inode
, pgoff_t idx
,
1159 unsigned int max_pages
)
1161 struct address_space
*mapping
= inode
->i_mapping
;
1163 struct pagevec pvec
;
1165 int i
, nr_pages
, done
= 0;
1169 pagevec_init(&pvec
, 0);
1172 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1173 PAGECACHE_TAG_DIRTY
,
1174 (pgoff_t
)PAGEVEC_SIZE
);
1177 for (i
= 0; i
< nr_pages
; i
++) {
1178 struct page
*page
= pvec
.pages
[i
];
1179 struct buffer_head
*bh
, *head
;
1182 if (unlikely(page
->mapping
!= mapping
) ||
1184 PageWriteback(page
) ||
1185 page
->index
!= idx
) {
1190 if (page_has_buffers(page
)) {
1191 bh
= head
= page_buffers(page
);
1193 if (!buffer_delay(bh
) &&
1194 !buffer_unwritten(bh
))
1196 bh
= bh
->b_this_page
;
1197 } while (!done
&& (bh
!= head
));
1204 if (num
>= max_pages
)
1207 pagevec_release(&pvec
);
1213 * The ext4_map_blocks() function tries to look up the requested blocks,
1214 * and returns if the blocks are already mapped.
1216 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1217 * and store the allocated blocks in the result buffer head and mark it
1220 * If file type is extents based, it will call ext4_ext_map_blocks(),
1221 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
1224 * On success, it returns the number of blocks being mapped or allocate.
1225 * if create==0 and the blocks are pre-allocated and uninitialized block,
1226 * the result buffer head is unmapped. If the create ==1, it will make sure
1227 * the buffer head is mapped.
1229 * It returns 0 if plain look up failed (blocks have not been allocated), in
1230 * that casem, buffer head is unmapped
1232 * It returns the error in case of allocation failure.
1234 int ext4_map_blocks(handle_t
*handle
, struct inode
*inode
,
1235 struct ext4_map_blocks
*map
, int flags
)
1240 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
1241 "logical block %lu\n", inode
->i_ino
, flags
, map
->m_len
,
1242 (unsigned long) map
->m_lblk
);
1244 * Try to see if we can get the block without requesting a new
1245 * file system block.
1247 down_read((&EXT4_I(inode
)->i_data_sem
));
1248 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
1249 retval
= ext4_ext_map_blocks(handle
, inode
, map
, 0);
1251 retval
= ext4_ind_map_blocks(handle
, inode
, map
, 0);
1253 up_read((&EXT4_I(inode
)->i_data_sem
));
1255 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
) {
1256 int ret
= check_block_validity(inode
, map
);
1261 /* If it is only a block(s) look up */
1262 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
1266 * Returns if the blocks have already allocated
1268 * Note that if blocks have been preallocated
1269 * ext4_ext_get_block() returns th create = 0
1270 * with buffer head unmapped.
1272 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
)
1276 * When we call get_blocks without the create flag, the
1277 * BH_Unwritten flag could have gotten set if the blocks
1278 * requested were part of a uninitialized extent. We need to
1279 * clear this flag now that we are committed to convert all or
1280 * part of the uninitialized extent to be an initialized
1281 * extent. This is because we need to avoid the combination
1282 * of BH_Unwritten and BH_Mapped flags being simultaneously
1283 * set on the buffer_head.
1285 map
->m_flags
&= ~EXT4_MAP_UNWRITTEN
;
1288 * New blocks allocate and/or writing to uninitialized extent
1289 * will possibly result in updating i_data, so we take
1290 * the write lock of i_data_sem, and call get_blocks()
1291 * with create == 1 flag.
1293 down_write((&EXT4_I(inode
)->i_data_sem
));
1296 * if the caller is from delayed allocation writeout path
1297 * we have already reserved fs blocks for allocation
1298 * let the underlying get_block() function know to
1299 * avoid double accounting
1301 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1302 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1304 * We need to check for EXT4 here because migrate
1305 * could have changed the inode type in between
1307 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
1308 retval
= ext4_ext_map_blocks(handle
, inode
, map
, flags
);
1310 retval
= ext4_ind_map_blocks(handle
, inode
, map
, flags
);
1312 if (retval
> 0 && map
->m_flags
& EXT4_MAP_NEW
) {
1314 * We allocated new blocks which will result in
1315 * i_data's format changing. Force the migrate
1316 * to fail by clearing migrate flags
1318 ext4_clear_inode_state(inode
, EXT4_STATE_EXT_MIGRATE
);
1322 * Update reserved blocks/metadata blocks after successful
1323 * block allocation which had been deferred till now. We don't
1324 * support fallocate for non extent files. So we can update
1325 * reserve space here.
1328 (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
))
1329 ext4_da_update_reserve_space(inode
, retval
, 1);
1331 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1332 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1334 up_write((&EXT4_I(inode
)->i_data_sem
));
1335 if (retval
> 0 && map
->m_flags
& EXT4_MAP_MAPPED
) {
1336 int ret
= check_block_validity(inode
, map
);
1343 /* Maximum number of blocks we map for direct IO at once. */
1344 #define DIO_MAX_BLOCKS 4096
1346 static int _ext4_get_block(struct inode
*inode
, sector_t iblock
,
1347 struct buffer_head
*bh
, int flags
)
1349 handle_t
*handle
= ext4_journal_current_handle();
1350 struct ext4_map_blocks map
;
1351 int ret
= 0, started
= 0;
1354 map
.m_lblk
= iblock
;
1355 map
.m_len
= bh
->b_size
>> inode
->i_blkbits
;
1357 if (flags
&& !handle
) {
1358 /* Direct IO write... */
1359 if (map
.m_len
> DIO_MAX_BLOCKS
)
1360 map
.m_len
= DIO_MAX_BLOCKS
;
1361 dio_credits
= ext4_chunk_trans_blocks(inode
, map
.m_len
);
1362 handle
= ext4_journal_start(inode
, dio_credits
);
1363 if (IS_ERR(handle
)) {
1364 ret
= PTR_ERR(handle
);
1370 ret
= ext4_map_blocks(handle
, inode
, &map
, flags
);
1372 map_bh(bh
, inode
->i_sb
, map
.m_pblk
);
1373 bh
->b_state
= (bh
->b_state
& ~EXT4_MAP_FLAGS
) | map
.m_flags
;
1374 bh
->b_size
= inode
->i_sb
->s_blocksize
* map
.m_len
;
1378 ext4_journal_stop(handle
);
1382 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1383 struct buffer_head
*bh
, int create
)
1385 return _ext4_get_block(inode
, iblock
, bh
,
1386 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1390 * `handle' can be NULL if create is zero
1392 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1393 ext4_lblk_t block
, int create
, int *errp
)
1395 struct ext4_map_blocks map
;
1396 struct buffer_head
*bh
;
1399 J_ASSERT(handle
!= NULL
|| create
== 0);
1403 err
= ext4_map_blocks(handle
, inode
, &map
,
1404 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1412 bh
= sb_getblk(inode
->i_sb
, map
.m_pblk
);
1417 if (map
.m_flags
& EXT4_MAP_NEW
) {
1418 J_ASSERT(create
!= 0);
1419 J_ASSERT(handle
!= NULL
);
1422 * Now that we do not always journal data, we should
1423 * keep in mind whether this should always journal the
1424 * new buffer as metadata. For now, regular file
1425 * writes use ext4_get_block instead, so it's not a
1429 BUFFER_TRACE(bh
, "call get_create_access");
1430 fatal
= ext4_journal_get_create_access(handle
, bh
);
1431 if (!fatal
&& !buffer_uptodate(bh
)) {
1432 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1433 set_buffer_uptodate(bh
);
1436 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1437 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1441 BUFFER_TRACE(bh
, "not a new buffer");
1451 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1452 ext4_lblk_t block
, int create
, int *err
)
1454 struct buffer_head
*bh
;
1456 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1459 if (buffer_uptodate(bh
))
1461 ll_rw_block(READ_META
, 1, &bh
);
1463 if (buffer_uptodate(bh
))
1470 static int walk_page_buffers(handle_t
*handle
,
1471 struct buffer_head
*head
,
1475 int (*fn
)(handle_t
*handle
,
1476 struct buffer_head
*bh
))
1478 struct buffer_head
*bh
;
1479 unsigned block_start
, block_end
;
1480 unsigned blocksize
= head
->b_size
;
1482 struct buffer_head
*next
;
1484 for (bh
= head
, block_start
= 0;
1485 ret
== 0 && (bh
!= head
|| !block_start
);
1486 block_start
= block_end
, bh
= next
) {
1487 next
= bh
->b_this_page
;
1488 block_end
= block_start
+ blocksize
;
1489 if (block_end
<= from
|| block_start
>= to
) {
1490 if (partial
&& !buffer_uptodate(bh
))
1494 err
= (*fn
)(handle
, bh
);
1502 * To preserve ordering, it is essential that the hole instantiation and
1503 * the data write be encapsulated in a single transaction. We cannot
1504 * close off a transaction and start a new one between the ext4_get_block()
1505 * and the commit_write(). So doing the jbd2_journal_start at the start of
1506 * prepare_write() is the right place.
1508 * Also, this function can nest inside ext4_writepage() ->
1509 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1510 * has generated enough buffer credits to do the whole page. So we won't
1511 * block on the journal in that case, which is good, because the caller may
1514 * By accident, ext4 can be reentered when a transaction is open via
1515 * quota file writes. If we were to commit the transaction while thus
1516 * reentered, there can be a deadlock - we would be holding a quota
1517 * lock, and the commit would never complete if another thread had a
1518 * transaction open and was blocking on the quota lock - a ranking
1521 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1522 * will _not_ run commit under these circumstances because handle->h_ref
1523 * is elevated. We'll still have enough credits for the tiny quotafile
1526 static int do_journal_get_write_access(handle_t
*handle
,
1527 struct buffer_head
*bh
)
1529 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1531 return ext4_journal_get_write_access(handle
, bh
);
1535 * Truncate blocks that were not used by write. We have to truncate the
1536 * pagecache as well so that corresponding buffers get properly unmapped.
1538 static void ext4_truncate_failed_write(struct inode
*inode
)
1540 truncate_inode_pages(inode
->i_mapping
, inode
->i_size
);
1541 ext4_truncate(inode
);
1544 static int ext4_get_block_write(struct inode
*inode
, sector_t iblock
,
1545 struct buffer_head
*bh_result
, int create
);
1546 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1547 loff_t pos
, unsigned len
, unsigned flags
,
1548 struct page
**pagep
, void **fsdata
)
1550 struct inode
*inode
= mapping
->host
;
1551 int ret
, needed_blocks
;
1558 trace_ext4_write_begin(inode
, pos
, len
, flags
);
1560 * Reserve one block more for addition to orphan list in case
1561 * we allocate blocks but write fails for some reason
1563 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
1564 index
= pos
>> PAGE_CACHE_SHIFT
;
1565 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1569 handle
= ext4_journal_start(inode
, needed_blocks
);
1570 if (IS_ERR(handle
)) {
1571 ret
= PTR_ERR(handle
);
1575 /* We cannot recurse into the filesystem as the transaction is already
1577 flags
|= AOP_FLAG_NOFS
;
1579 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1581 ext4_journal_stop(handle
);
1587 if (ext4_should_dioread_nolock(inode
))
1588 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
,
1589 fsdata
, ext4_get_block_write
);
1591 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
,
1592 fsdata
, ext4_get_block
);
1594 if (!ret
&& ext4_should_journal_data(inode
)) {
1595 ret
= walk_page_buffers(handle
, page_buffers(page
),
1596 from
, to
, NULL
, do_journal_get_write_access
);
1601 page_cache_release(page
);
1603 * block_write_begin may have instantiated a few blocks
1604 * outside i_size. Trim these off again. Don't need
1605 * i_size_read because we hold i_mutex.
1607 * Add inode to orphan list in case we crash before
1610 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1611 ext4_orphan_add(handle
, inode
);
1613 ext4_journal_stop(handle
);
1614 if (pos
+ len
> inode
->i_size
) {
1615 ext4_truncate_failed_write(inode
);
1617 * If truncate failed early the inode might
1618 * still be on the orphan list; we need to
1619 * make sure the inode is removed from the
1620 * orphan list in that case.
1623 ext4_orphan_del(NULL
, inode
);
1627 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1633 /* For write_end() in data=journal mode */
1634 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1636 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1638 set_buffer_uptodate(bh
);
1639 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1642 static int ext4_generic_write_end(struct file
*file
,
1643 struct address_space
*mapping
,
1644 loff_t pos
, unsigned len
, unsigned copied
,
1645 struct page
*page
, void *fsdata
)
1647 int i_size_changed
= 0;
1648 struct inode
*inode
= mapping
->host
;
1649 handle_t
*handle
= ext4_journal_current_handle();
1651 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1654 * No need to use i_size_read() here, the i_size
1655 * cannot change under us because we hold i_mutex.
1657 * But it's important to update i_size while still holding page lock:
1658 * page writeout could otherwise come in and zero beyond i_size.
1660 if (pos
+ copied
> inode
->i_size
) {
1661 i_size_write(inode
, pos
+ copied
);
1665 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
1666 /* We need to mark inode dirty even if
1667 * new_i_size is less that inode->i_size
1668 * bu greater than i_disksize.(hint delalloc)
1670 ext4_update_i_disksize(inode
, (pos
+ copied
));
1674 page_cache_release(page
);
1677 * Don't mark the inode dirty under page lock. First, it unnecessarily
1678 * makes the holding time of page lock longer. Second, it forces lock
1679 * ordering of page lock and transaction start for journaling
1683 ext4_mark_inode_dirty(handle
, inode
);
1689 * We need to pick up the new inode size which generic_commit_write gave us
1690 * `file' can be NULL - eg, when called from page_symlink().
1692 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1693 * buffers are managed internally.
1695 static int ext4_ordered_write_end(struct file
*file
,
1696 struct address_space
*mapping
,
1697 loff_t pos
, unsigned len
, unsigned copied
,
1698 struct page
*page
, void *fsdata
)
1700 handle_t
*handle
= ext4_journal_current_handle();
1701 struct inode
*inode
= mapping
->host
;
1704 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
1705 ret
= ext4_jbd2_file_inode(handle
, inode
);
1708 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1711 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1712 /* if we have allocated more blocks and copied
1713 * less. We will have blocks allocated outside
1714 * inode->i_size. So truncate them
1716 ext4_orphan_add(handle
, inode
);
1720 ret2
= ext4_journal_stop(handle
);
1724 if (pos
+ len
> inode
->i_size
) {
1725 ext4_truncate_failed_write(inode
);
1727 * If truncate failed early the inode might still be
1728 * on the orphan list; we need to make sure the inode
1729 * is removed from the orphan list in that case.
1732 ext4_orphan_del(NULL
, inode
);
1736 return ret
? ret
: copied
;
1739 static int ext4_writeback_write_end(struct file
*file
,
1740 struct address_space
*mapping
,
1741 loff_t pos
, unsigned len
, unsigned copied
,
1742 struct page
*page
, void *fsdata
)
1744 handle_t
*handle
= ext4_journal_current_handle();
1745 struct inode
*inode
= mapping
->host
;
1748 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1749 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1752 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1753 /* if we have allocated more blocks and copied
1754 * less. We will have blocks allocated outside
1755 * inode->i_size. So truncate them
1757 ext4_orphan_add(handle
, inode
);
1762 ret2
= ext4_journal_stop(handle
);
1766 if (pos
+ len
> inode
->i_size
) {
1767 ext4_truncate_failed_write(inode
);
1769 * If truncate failed early the inode might still be
1770 * on the orphan list; we need to make sure the inode
1771 * is removed from the orphan list in that case.
1774 ext4_orphan_del(NULL
, inode
);
1777 return ret
? ret
: copied
;
1780 static int ext4_journalled_write_end(struct file
*file
,
1781 struct address_space
*mapping
,
1782 loff_t pos
, unsigned len
, unsigned copied
,
1783 struct page
*page
, void *fsdata
)
1785 handle_t
*handle
= ext4_journal_current_handle();
1786 struct inode
*inode
= mapping
->host
;
1792 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1793 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1797 if (!PageUptodate(page
))
1799 page_zero_new_buffers(page
, from
+copied
, to
);
1802 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1803 to
, &partial
, write_end_fn
);
1805 SetPageUptodate(page
);
1806 new_i_size
= pos
+ copied
;
1807 if (new_i_size
> inode
->i_size
)
1808 i_size_write(inode
, pos
+copied
);
1809 ext4_set_inode_state(inode
, EXT4_STATE_JDATA
);
1810 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1811 ext4_update_i_disksize(inode
, new_i_size
);
1812 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1818 page_cache_release(page
);
1819 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1820 /* if we have allocated more blocks and copied
1821 * less. We will have blocks allocated outside
1822 * inode->i_size. So truncate them
1824 ext4_orphan_add(handle
, inode
);
1826 ret2
= ext4_journal_stop(handle
);
1829 if (pos
+ len
> inode
->i_size
) {
1830 ext4_truncate_failed_write(inode
);
1832 * If truncate failed early the inode might still be
1833 * on the orphan list; we need to make sure the inode
1834 * is removed from the orphan list in that case.
1837 ext4_orphan_del(NULL
, inode
);
1840 return ret
? ret
: copied
;
1844 * Reserve a single block located at lblock
1846 static int ext4_da_reserve_space(struct inode
*inode
, sector_t lblock
)
1849 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1850 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1851 unsigned long md_needed
;
1855 * recalculate the amount of metadata blocks to reserve
1856 * in order to allocate nrblocks
1857 * worse case is one extent per block
1860 spin_lock(&ei
->i_block_reservation_lock
);
1861 md_needed
= ext4_calc_metadata_amount(inode
, lblock
);
1862 trace_ext4_da_reserve_space(inode
, md_needed
);
1863 spin_unlock(&ei
->i_block_reservation_lock
);
1866 * We will charge metadata quota at writeout time; this saves
1867 * us from metadata over-estimation, though we may go over by
1868 * a small amount in the end. Here we just reserve for data.
1870 ret
= dquot_reserve_block(inode
, 1);
1874 * We do still charge estimated metadata to the sb though;
1875 * we cannot afford to run out of free blocks.
1877 if (ext4_claim_free_blocks(sbi
, md_needed
+ 1)) {
1878 dquot_release_reservation_block(inode
, 1);
1879 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1885 spin_lock(&ei
->i_block_reservation_lock
);
1886 ei
->i_reserved_data_blocks
++;
1887 ei
->i_reserved_meta_blocks
+= md_needed
;
1888 spin_unlock(&ei
->i_block_reservation_lock
);
1890 return 0; /* success */
1893 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1895 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1896 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1899 return; /* Nothing to release, exit */
1901 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1903 trace_ext4_da_release_space(inode
, to_free
);
1904 if (unlikely(to_free
> ei
->i_reserved_data_blocks
)) {
1906 * if there aren't enough reserved blocks, then the
1907 * counter is messed up somewhere. Since this
1908 * function is called from invalidate page, it's
1909 * harmless to return without any action.
1911 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "ext4_da_release_space: "
1912 "ino %lu, to_free %d with only %d reserved "
1913 "data blocks\n", inode
->i_ino
, to_free
,
1914 ei
->i_reserved_data_blocks
);
1916 to_free
= ei
->i_reserved_data_blocks
;
1918 ei
->i_reserved_data_blocks
-= to_free
;
1920 if (ei
->i_reserved_data_blocks
== 0) {
1922 * We can release all of the reserved metadata blocks
1923 * only when we have written all of the delayed
1924 * allocation blocks.
1926 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
1927 ei
->i_reserved_meta_blocks
);
1928 ei
->i_reserved_meta_blocks
= 0;
1929 ei
->i_da_metadata_calc_len
= 0;
1932 /* update fs dirty data blocks counter */
1933 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, to_free
);
1935 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1937 dquot_release_reservation_block(inode
, to_free
);
1940 static void ext4_da_page_release_reservation(struct page
*page
,
1941 unsigned long offset
)
1944 struct buffer_head
*head
, *bh
;
1945 unsigned int curr_off
= 0;
1947 head
= page_buffers(page
);
1950 unsigned int next_off
= curr_off
+ bh
->b_size
;
1952 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1954 clear_buffer_delay(bh
);
1956 curr_off
= next_off
;
1957 } while ((bh
= bh
->b_this_page
) != head
);
1958 ext4_da_release_space(page
->mapping
->host
, to_release
);
1962 * Delayed allocation stuff
1966 * mpage_da_submit_io - walks through extent of pages and try to write
1967 * them with writepage() call back
1969 * @mpd->inode: inode
1970 * @mpd->first_page: first page of the extent
1971 * @mpd->next_page: page after the last page of the extent
1973 * By the time mpage_da_submit_io() is called we expect all blocks
1974 * to be allocated. this may be wrong if allocation failed.
1976 * As pages are already locked by write_cache_pages(), we can't use it
1978 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1981 struct pagevec pvec
;
1982 unsigned long index
, end
;
1983 int ret
= 0, err
, nr_pages
, i
;
1984 struct inode
*inode
= mpd
->inode
;
1985 struct address_space
*mapping
= inode
->i_mapping
;
1987 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1989 * We need to start from the first_page to the next_page - 1
1990 * to make sure we also write the mapped dirty buffer_heads.
1991 * If we look at mpd->b_blocknr we would only be looking
1992 * at the currently mapped buffer_heads.
1994 index
= mpd
->first_page
;
1995 end
= mpd
->next_page
- 1;
1997 pagevec_init(&pvec
, 0);
1998 while (index
<= end
) {
1999 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2002 for (i
= 0; i
< nr_pages
; i
++) {
2003 struct page
*page
= pvec
.pages
[i
];
2005 index
= page
->index
;
2010 BUG_ON(!PageLocked(page
));
2011 BUG_ON(PageWriteback(page
));
2013 pages_skipped
= mpd
->wbc
->pages_skipped
;
2014 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
2015 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
2017 * have successfully written the page
2018 * without skipping the same
2020 mpd
->pages_written
++;
2022 * In error case, we have to continue because
2023 * remaining pages are still locked
2024 * XXX: unlock and re-dirty them?
2029 pagevec_release(&pvec
);
2035 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
2037 * the function goes through all passed space and put actual disk
2038 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
2040 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
,
2041 struct ext4_map_blocks
*map
)
2043 struct inode
*inode
= mpd
->inode
;
2044 struct address_space
*mapping
= inode
->i_mapping
;
2045 int blocks
= map
->m_len
;
2046 sector_t pblock
= map
->m_pblk
, cur_logical
;
2047 struct buffer_head
*head
, *bh
;
2049 struct pagevec pvec
;
2052 index
= map
->m_lblk
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2053 end
= (map
->m_lblk
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2054 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2056 pagevec_init(&pvec
, 0);
2058 while (index
<= end
) {
2059 /* XXX: optimize tail */
2060 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2063 for (i
= 0; i
< nr_pages
; i
++) {
2064 struct page
*page
= pvec
.pages
[i
];
2066 index
= page
->index
;
2071 BUG_ON(!PageLocked(page
));
2072 BUG_ON(PageWriteback(page
));
2073 BUG_ON(!page_has_buffers(page
));
2075 bh
= page_buffers(page
);
2078 /* skip blocks out of the range */
2080 if (cur_logical
>= map
->m_lblk
)
2083 } while ((bh
= bh
->b_this_page
) != head
);
2086 if (cur_logical
>= map
->m_lblk
+ blocks
)
2089 if (buffer_delay(bh
) || buffer_unwritten(bh
)) {
2091 BUG_ON(bh
->b_bdev
!= inode
->i_sb
->s_bdev
);
2093 if (buffer_delay(bh
)) {
2094 clear_buffer_delay(bh
);
2095 bh
->b_blocknr
= pblock
;
2098 * unwritten already should have
2099 * blocknr assigned. Verify that
2101 clear_buffer_unwritten(bh
);
2102 BUG_ON(bh
->b_blocknr
!= pblock
);
2105 } else if (buffer_mapped(bh
))
2106 BUG_ON(bh
->b_blocknr
!= pblock
);
2108 if (map
->m_flags
& EXT4_MAP_UNINIT
)
2109 set_buffer_uninit(bh
);
2112 } while ((bh
= bh
->b_this_page
) != head
);
2114 pagevec_release(&pvec
);
2119 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
2120 sector_t logical
, long blk_cnt
)
2124 struct pagevec pvec
;
2125 struct inode
*inode
= mpd
->inode
;
2126 struct address_space
*mapping
= inode
->i_mapping
;
2128 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2129 end
= (logical
+ blk_cnt
- 1) >>
2130 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2131 while (index
<= end
) {
2132 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2135 for (i
= 0; i
< nr_pages
; i
++) {
2136 struct page
*page
= pvec
.pages
[i
];
2137 if (page
->index
> end
)
2139 BUG_ON(!PageLocked(page
));
2140 BUG_ON(PageWriteback(page
));
2141 block_invalidatepage(page
, 0);
2142 ClearPageUptodate(page
);
2145 index
= pvec
.pages
[nr_pages
- 1]->index
+ 1;
2146 pagevec_release(&pvec
);
2151 static void ext4_print_free_blocks(struct inode
*inode
)
2153 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2154 printk(KERN_CRIT
"Total free blocks count %lld\n",
2155 ext4_count_free_blocks(inode
->i_sb
));
2156 printk(KERN_CRIT
"Free/Dirty block details\n");
2157 printk(KERN_CRIT
"free_blocks=%lld\n",
2158 (long long) percpu_counter_sum(&sbi
->s_freeblocks_counter
));
2159 printk(KERN_CRIT
"dirty_blocks=%lld\n",
2160 (long long) percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
2161 printk(KERN_CRIT
"Block reservation details\n");
2162 printk(KERN_CRIT
"i_reserved_data_blocks=%u\n",
2163 EXT4_I(inode
)->i_reserved_data_blocks
);
2164 printk(KERN_CRIT
"i_reserved_meta_blocks=%u\n",
2165 EXT4_I(inode
)->i_reserved_meta_blocks
);
2170 * mpage_da_map_blocks - go through given space
2172 * @mpd - bh describing space
2174 * The function skips space we know is already mapped to disk blocks.
2177 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
2179 int err
, blks
, get_blocks_flags
;
2180 struct ext4_map_blocks map
;
2181 sector_t next
= mpd
->b_blocknr
;
2182 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2183 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
2184 handle_t
*handle
= NULL
;
2187 * We consider only non-mapped and non-allocated blocks
2189 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2190 !(mpd
->b_state
& (1 << BH_Delay
)) &&
2191 !(mpd
->b_state
& (1 << BH_Unwritten
)))
2195 * If we didn't accumulate anything to write simply return
2200 handle
= ext4_journal_current_handle();
2204 * Call ext4_map_blocks() to allocate any delayed allocation
2205 * blocks, or to convert an uninitialized extent to be
2206 * initialized (in the case where we have written into
2207 * one or more preallocated blocks).
2209 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2210 * indicate that we are on the delayed allocation path. This
2211 * affects functions in many different parts of the allocation
2212 * call path. This flag exists primarily because we don't
2213 * want to change *many* call functions, so ext4_map_blocks()
2214 * will set the magic i_delalloc_reserved_flag once the
2215 * inode's allocation semaphore is taken.
2217 * If the blocks in questions were delalloc blocks, set
2218 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2219 * variables are updated after the blocks have been allocated.
2222 map
.m_len
= max_blocks
;
2223 get_blocks_flags
= EXT4_GET_BLOCKS_CREATE
;
2224 if (ext4_should_dioread_nolock(mpd
->inode
))
2225 get_blocks_flags
|= EXT4_GET_BLOCKS_IO_CREATE_EXT
;
2226 if (mpd
->b_state
& (1 << BH_Delay
))
2227 get_blocks_flags
|= EXT4_GET_BLOCKS_DELALLOC_RESERVE
;
2229 blks
= ext4_map_blocks(handle
, mpd
->inode
, &map
, get_blocks_flags
);
2233 * If get block returns with error we simply
2234 * return. Later writepage will redirty the page and
2235 * writepages will find the dirty page again
2240 if (err
== -ENOSPC
&&
2241 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
2247 * get block failure will cause us to loop in
2248 * writepages, because a_ops->writepage won't be able
2249 * to make progress. The page will be redirtied by
2250 * writepage and writepages will again try to write
2253 ext4_msg(mpd
->inode
->i_sb
, KERN_CRIT
,
2254 "delayed block allocation failed for inode %lu at "
2255 "logical offset %llu with max blocks %zd with "
2256 "error %d", mpd
->inode
->i_ino
,
2257 (unsigned long long) next
,
2258 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2259 printk(KERN_CRIT
"This should not happen!! "
2260 "Data will be lost\n");
2261 if (err
== -ENOSPC
) {
2262 ext4_print_free_blocks(mpd
->inode
);
2264 /* invalidate all the pages */
2265 ext4_da_block_invalidatepages(mpd
, next
,
2266 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2271 if (map
.m_flags
& EXT4_MAP_NEW
) {
2272 struct block_device
*bdev
= mpd
->inode
->i_sb
->s_bdev
;
2275 for (i
= 0; i
< map
.m_len
; i
++)
2276 unmap_underlying_metadata(bdev
, map
.m_pblk
+ i
);
2280 * If blocks are delayed marked, we need to
2281 * put actual blocknr and drop delayed bit
2283 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2284 (mpd
->b_state
& (1 << BH_Unwritten
)))
2285 mpage_put_bnr_to_bhs(mpd
, &map
);
2287 if (ext4_should_order_data(mpd
->inode
)) {
2288 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
2294 * Update on-disk size along with block allocation.
2296 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
2297 if (disksize
> i_size_read(mpd
->inode
))
2298 disksize
= i_size_read(mpd
->inode
);
2299 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
2300 ext4_update_i_disksize(mpd
->inode
, disksize
);
2301 return ext4_mark_inode_dirty(handle
, mpd
->inode
);
2307 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2308 (1 << BH_Delay) | (1 << BH_Unwritten))
2311 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2313 * @mpd->lbh - extent of blocks
2314 * @logical - logical number of the block in the file
2315 * @bh - bh of the block (used to access block's state)
2317 * the function is used to collect contig. blocks in same state
2319 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2320 sector_t logical
, size_t b_size
,
2321 unsigned long b_state
)
2324 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2327 * XXX Don't go larger than mballoc is willing to allocate
2328 * This is a stopgap solution. We eventually need to fold
2329 * mpage_da_submit_io() into this function and then call
2330 * ext4_map_blocks() multiple times in a loop
2332 if (nrblocks
>= 8*1024*1024/mpd
->inode
->i_sb
->s_blocksize
)
2335 /* check if thereserved journal credits might overflow */
2336 if (!(ext4_test_inode_flag(mpd
->inode
, EXT4_INODE_EXTENTS
))) {
2337 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2339 * With non-extent format we are limited by the journal
2340 * credit available. Total credit needed to insert
2341 * nrblocks contiguous blocks is dependent on the
2342 * nrblocks. So limit nrblocks.
2345 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2346 EXT4_MAX_TRANS_DATA
) {
2348 * Adding the new buffer_head would make it cross the
2349 * allowed limit for which we have journal credit
2350 * reserved. So limit the new bh->b_size
2352 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2353 mpd
->inode
->i_blkbits
;
2354 /* we will do mpage_da_submit_io in the next loop */
2358 * First block in the extent
2360 if (mpd
->b_size
== 0) {
2361 mpd
->b_blocknr
= logical
;
2362 mpd
->b_size
= b_size
;
2363 mpd
->b_state
= b_state
& BH_FLAGS
;
2367 next
= mpd
->b_blocknr
+ nrblocks
;
2369 * Can we merge the block to our big extent?
2371 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2372 mpd
->b_size
+= b_size
;
2378 * We couldn't merge the block to our extent, so we
2379 * need to flush current extent and start new one
2381 if (mpage_da_map_blocks(mpd
) == 0)
2382 mpage_da_submit_io(mpd
);
2387 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
)
2389 return (buffer_delay(bh
) || buffer_unwritten(bh
)) && buffer_dirty(bh
);
2393 * __mpage_da_writepage - finds extent of pages and blocks
2395 * @page: page to consider
2396 * @wbc: not used, we just follow rules
2399 * The function finds extents of pages and scan them for all blocks.
2401 static int __mpage_da_writepage(struct page
*page
,
2402 struct writeback_control
*wbc
, void *data
)
2404 struct mpage_da_data
*mpd
= data
;
2405 struct inode
*inode
= mpd
->inode
;
2406 struct buffer_head
*bh
, *head
;
2410 * Can we merge this page to current extent?
2412 if (mpd
->next_page
!= page
->index
) {
2414 * Nope, we can't. So, we map non-allocated blocks
2415 * and start IO on them using writepage()
2417 if (mpd
->next_page
!= mpd
->first_page
) {
2418 if (mpage_da_map_blocks(mpd
) == 0)
2419 mpage_da_submit_io(mpd
);
2421 * skip rest of the page in the page_vec
2424 redirty_page_for_writepage(wbc
, page
);
2426 return MPAGE_DA_EXTENT_TAIL
;
2430 * Start next extent of pages ...
2432 mpd
->first_page
= page
->index
;
2442 mpd
->next_page
= page
->index
+ 1;
2443 logical
= (sector_t
) page
->index
<<
2444 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2446 if (!page_has_buffers(page
)) {
2447 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2448 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2450 return MPAGE_DA_EXTENT_TAIL
;
2453 * Page with regular buffer heads, just add all dirty ones
2455 head
= page_buffers(page
);
2458 BUG_ON(buffer_locked(bh
));
2460 * We need to try to allocate
2461 * unmapped blocks in the same page.
2462 * Otherwise we won't make progress
2463 * with the page in ext4_writepage
2465 if (ext4_bh_delay_or_unwritten(NULL
, bh
)) {
2466 mpage_add_bh_to_extent(mpd
, logical
,
2470 return MPAGE_DA_EXTENT_TAIL
;
2471 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2473 * mapped dirty buffer. We need to update
2474 * the b_state because we look at
2475 * b_state in mpage_da_map_blocks. We don't
2476 * update b_size because if we find an
2477 * unmapped buffer_head later we need to
2478 * use the b_state flag of that buffer_head.
2480 if (mpd
->b_size
== 0)
2481 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2484 } while ((bh
= bh
->b_this_page
) != head
);
2491 * This is a special get_blocks_t callback which is used by
2492 * ext4_da_write_begin(). It will either return mapped block or
2493 * reserve space for a single block.
2495 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2496 * We also have b_blocknr = -1 and b_bdev initialized properly
2498 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2499 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2500 * initialized properly.
2502 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2503 struct buffer_head
*bh
, int create
)
2505 struct ext4_map_blocks map
;
2507 sector_t invalid_block
= ~((sector_t
) 0xffff);
2509 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
2512 BUG_ON(create
== 0);
2513 BUG_ON(bh
->b_size
!= inode
->i_sb
->s_blocksize
);
2515 map
.m_lblk
= iblock
;
2519 * first, we need to know whether the block is allocated already
2520 * preallocated blocks are unmapped but should treated
2521 * the same as allocated blocks.
2523 ret
= ext4_map_blocks(NULL
, inode
, &map
, 0);
2527 if (buffer_delay(bh
))
2528 return 0; /* Not sure this could or should happen */
2530 * XXX: __block_prepare_write() unmaps passed block,
2533 ret
= ext4_da_reserve_space(inode
, iblock
);
2535 /* not enough space to reserve */
2538 map_bh(bh
, inode
->i_sb
, invalid_block
);
2540 set_buffer_delay(bh
);
2544 map_bh(bh
, inode
->i_sb
, map
.m_pblk
);
2545 bh
->b_state
= (bh
->b_state
& ~EXT4_MAP_FLAGS
) | map
.m_flags
;
2547 if (buffer_unwritten(bh
)) {
2548 /* A delayed write to unwritten bh should be marked
2549 * new and mapped. Mapped ensures that we don't do
2550 * get_block multiple times when we write to the same
2551 * offset and new ensures that we do proper zero out
2552 * for partial write.
2555 set_buffer_mapped(bh
);
2561 * This function is used as a standard get_block_t calback function
2562 * when there is no desire to allocate any blocks. It is used as a
2563 * callback function for block_prepare_write() and block_write_full_page().
2564 * These functions should only try to map a single block at a time.
2566 * Since this function doesn't do block allocations even if the caller
2567 * requests it by passing in create=1, it is critically important that
2568 * any caller checks to make sure that any buffer heads are returned
2569 * by this function are either all already mapped or marked for
2570 * delayed allocation before calling block_write_full_page(). Otherwise,
2571 * b_blocknr could be left unitialized, and the page write functions will
2572 * be taken by surprise.
2574 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
2575 struct buffer_head
*bh_result
, int create
)
2577 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2578 return _ext4_get_block(inode
, iblock
, bh_result
, 0);
2581 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2587 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2593 static int __ext4_journalled_writepage(struct page
*page
,
2596 struct address_space
*mapping
= page
->mapping
;
2597 struct inode
*inode
= mapping
->host
;
2598 struct buffer_head
*page_bufs
;
2599 handle_t
*handle
= NULL
;
2603 page_bufs
= page_buffers(page
);
2605 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bget_one
);
2606 /* As soon as we unlock the page, it can go away, but we have
2607 * references to buffers so we are safe */
2610 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
2611 if (IS_ERR(handle
)) {
2612 ret
= PTR_ERR(handle
);
2616 ret
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2617 do_journal_get_write_access
);
2619 err
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2623 err
= ext4_journal_stop(handle
);
2627 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bput_one
);
2628 ext4_set_inode_state(inode
, EXT4_STATE_JDATA
);
2633 static int ext4_set_bh_endio(struct buffer_head
*bh
, struct inode
*inode
);
2634 static void ext4_end_io_buffer_write(struct buffer_head
*bh
, int uptodate
);
2637 * Note that we don't need to start a transaction unless we're journaling data
2638 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2639 * need to file the inode to the transaction's list in ordered mode because if
2640 * we are writing back data added by write(), the inode is already there and if
2641 * we are writing back data modified via mmap(), noone guarantees in which
2642 * transaction the data will hit the disk. In case we are journaling data, we
2643 * cannot start transaction directly because transaction start ranks above page
2644 * lock so we have to do some magic.
2646 * This function can get called via...
2647 * - ext4_da_writepages after taking page lock (have journal handle)
2648 * - journal_submit_inode_data_buffers (no journal handle)
2649 * - shrink_page_list via pdflush (no journal handle)
2650 * - grab_page_cache when doing write_begin (have journal handle)
2652 * We don't do any block allocation in this function. If we have page with
2653 * multiple blocks we need to write those buffer_heads that are mapped. This
2654 * is important for mmaped based write. So if we do with blocksize 1K
2655 * truncate(f, 1024);
2656 * a = mmap(f, 0, 4096);
2658 * truncate(f, 4096);
2659 * we have in the page first buffer_head mapped via page_mkwrite call back
2660 * but other bufer_heads would be unmapped but dirty(dirty done via the
2661 * do_wp_page). So writepage should write the first block. If we modify
2662 * the mmap area beyond 1024 we will again get a page_fault and the
2663 * page_mkwrite callback will do the block allocation and mark the
2664 * buffer_heads mapped.
2666 * We redirty the page if we have any buffer_heads that is either delay or
2667 * unwritten in the page.
2669 * We can get recursively called as show below.
2671 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2674 * But since we don't do any block allocation we should not deadlock.
2675 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2677 static int ext4_writepage(struct page
*page
,
2678 struct writeback_control
*wbc
)
2683 struct buffer_head
*page_bufs
= NULL
;
2684 struct inode
*inode
= page
->mapping
->host
;
2686 trace_ext4_writepage(inode
, page
);
2687 size
= i_size_read(inode
);
2688 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2689 len
= size
& ~PAGE_CACHE_MASK
;
2691 len
= PAGE_CACHE_SIZE
;
2693 if (page_has_buffers(page
)) {
2694 page_bufs
= page_buffers(page
);
2695 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2696 ext4_bh_delay_or_unwritten
)) {
2698 * We don't want to do block allocation
2699 * So redirty the page and return
2700 * We may reach here when we do a journal commit
2701 * via journal_submit_inode_data_buffers.
2702 * If we don't have mapping block we just ignore
2703 * them. We can also reach here via shrink_page_list
2705 redirty_page_for_writepage(wbc
, page
);
2711 * The test for page_has_buffers() is subtle:
2712 * We know the page is dirty but it lost buffers. That means
2713 * that at some moment in time after write_begin()/write_end()
2714 * has been called all buffers have been clean and thus they
2715 * must have been written at least once. So they are all
2716 * mapped and we can happily proceed with mapping them
2717 * and writing the page.
2719 * Try to initialize the buffer_heads and check whether
2720 * all are mapped and non delay. We don't want to
2721 * do block allocation here.
2723 ret
= block_prepare_write(page
, 0, len
,
2724 noalloc_get_block_write
);
2726 page_bufs
= page_buffers(page
);
2727 /* check whether all are mapped and non delay */
2728 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2729 ext4_bh_delay_or_unwritten
)) {
2730 redirty_page_for_writepage(wbc
, page
);
2736 * We can't do block allocation here
2737 * so just redity the page and unlock
2740 redirty_page_for_writepage(wbc
, page
);
2744 /* now mark the buffer_heads as dirty and uptodate */
2745 block_commit_write(page
, 0, len
);
2748 if (PageChecked(page
) && ext4_should_journal_data(inode
)) {
2750 * It's mmapped pagecache. Add buffers and journal it. There
2751 * doesn't seem much point in redirtying the page here.
2753 ClearPageChecked(page
);
2754 return __ext4_journalled_writepage(page
, len
);
2757 if (page_bufs
&& buffer_uninit(page_bufs
)) {
2758 ext4_set_bh_endio(page_bufs
, inode
);
2759 ret
= block_write_full_page_endio(page
, noalloc_get_block_write
,
2760 wbc
, ext4_end_io_buffer_write
);
2762 ret
= block_write_full_page(page
, noalloc_get_block_write
,
2769 * This is called via ext4_da_writepages() to
2770 * calulate the total number of credits to reserve to fit
2771 * a single extent allocation into a single transaction,
2772 * ext4_da_writpeages() will loop calling this before
2773 * the block allocation.
2776 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2778 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2781 * With non-extent format the journal credit needed to
2782 * insert nrblocks contiguous block is dependent on
2783 * number of contiguous block. So we will limit
2784 * number of contiguous block to a sane value
2786 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) &&
2787 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2788 max_blocks
= EXT4_MAX_TRANS_DATA
;
2790 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2794 * write_cache_pages_da - walk the list of dirty pages of the given
2795 * address space and call the callback function (which usually writes
2798 * This is a forked version of write_cache_pages(). Differences:
2799 * Range cyclic is ignored.
2800 * no_nrwrite_index_update is always presumed true
2802 static int write_cache_pages_da(struct address_space
*mapping
,
2803 struct writeback_control
*wbc
,
2804 struct mpage_da_data
*mpd
)
2808 struct pagevec pvec
;
2811 pgoff_t end
; /* Inclusive */
2812 long nr_to_write
= wbc
->nr_to_write
;
2814 pagevec_init(&pvec
, 0);
2815 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2816 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
2818 while (!done
&& (index
<= end
)) {
2821 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
2822 PAGECACHE_TAG_DIRTY
,
2823 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1);
2827 for (i
= 0; i
< nr_pages
; i
++) {
2828 struct page
*page
= pvec
.pages
[i
];
2831 * At this point, the page may be truncated or
2832 * invalidated (changing page->mapping to NULL), or
2833 * even swizzled back from swapper_space to tmpfs file
2834 * mapping. However, page->index will not change
2835 * because we have a reference on the page.
2837 if (page
->index
> end
) {
2845 * Page truncated or invalidated. We can freely skip it
2846 * then, even for data integrity operations: the page
2847 * has disappeared concurrently, so there could be no
2848 * real expectation of this data interity operation
2849 * even if there is now a new, dirty page at the same
2850 * pagecache address.
2852 if (unlikely(page
->mapping
!= mapping
)) {
2858 if (!PageDirty(page
)) {
2859 /* someone wrote it for us */
2860 goto continue_unlock
;
2863 if (PageWriteback(page
)) {
2864 if (wbc
->sync_mode
!= WB_SYNC_NONE
)
2865 wait_on_page_writeback(page
);
2867 goto continue_unlock
;
2870 BUG_ON(PageWriteback(page
));
2871 if (!clear_page_dirty_for_io(page
))
2872 goto continue_unlock
;
2874 ret
= __mpage_da_writepage(page
, wbc
, mpd
);
2875 if (unlikely(ret
)) {
2876 if (ret
== AOP_WRITEPAGE_ACTIVATE
) {
2885 if (nr_to_write
> 0) {
2887 if (nr_to_write
== 0 &&
2888 wbc
->sync_mode
== WB_SYNC_NONE
) {
2890 * We stop writing back only if we are
2891 * not doing integrity sync. In case of
2892 * integrity sync we have to keep going
2893 * because someone may be concurrently
2894 * dirtying pages, and we might have
2895 * synced a lot of newly appeared dirty
2896 * pages, but have not synced all of the
2904 pagevec_release(&pvec
);
2911 static int ext4_da_writepages(struct address_space
*mapping
,
2912 struct writeback_control
*wbc
)
2915 int range_whole
= 0;
2916 handle_t
*handle
= NULL
;
2917 struct mpage_da_data mpd
;
2918 struct inode
*inode
= mapping
->host
;
2919 int pages_written
= 0;
2921 unsigned int max_pages
;
2922 int range_cyclic
, cycled
= 1, io_done
= 0;
2923 int needed_blocks
, ret
= 0;
2924 long desired_nr_to_write
, nr_to_writebump
= 0;
2925 loff_t range_start
= wbc
->range_start
;
2926 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2928 trace_ext4_da_writepages(inode
, wbc
);
2931 * No pages to write? This is mainly a kludge to avoid starting
2932 * a transaction for special inodes like journal inode on last iput()
2933 * because that could violate lock ordering on umount
2935 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2939 * If the filesystem has aborted, it is read-only, so return
2940 * right away instead of dumping stack traces later on that
2941 * will obscure the real source of the problem. We test
2942 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2943 * the latter could be true if the filesystem is mounted
2944 * read-only, and in that case, ext4_da_writepages should
2945 * *never* be called, so if that ever happens, we would want
2948 if (unlikely(sbi
->s_mount_flags
& EXT4_MF_FS_ABORTED
))
2951 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2954 range_cyclic
= wbc
->range_cyclic
;
2955 if (wbc
->range_cyclic
) {
2956 index
= mapping
->writeback_index
;
2959 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2960 wbc
->range_end
= LLONG_MAX
;
2961 wbc
->range_cyclic
= 0;
2963 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2966 * This works around two forms of stupidity. The first is in
2967 * the writeback code, which caps the maximum number of pages
2968 * written to be 1024 pages. This is wrong on multiple
2969 * levels; different architectues have a different page size,
2970 * which changes the maximum amount of data which gets
2971 * written. Secondly, 4 megabytes is way too small. XFS
2972 * forces this value to be 16 megabytes by multiplying
2973 * nr_to_write parameter by four, and then relies on its
2974 * allocator to allocate larger extents to make them
2975 * contiguous. Unfortunately this brings us to the second
2976 * stupidity, which is that ext4's mballoc code only allocates
2977 * at most 2048 blocks. So we force contiguous writes up to
2978 * the number of dirty blocks in the inode, or
2979 * sbi->max_writeback_mb_bump whichever is smaller.
2981 max_pages
= sbi
->s_max_writeback_mb_bump
<< (20 - PAGE_CACHE_SHIFT
);
2982 if (!range_cyclic
&& range_whole
)
2983 desired_nr_to_write
= wbc
->nr_to_write
* 8;
2985 desired_nr_to_write
= ext4_num_dirty_pages(inode
, index
,
2987 if (desired_nr_to_write
> max_pages
)
2988 desired_nr_to_write
= max_pages
;
2990 if (wbc
->nr_to_write
< desired_nr_to_write
) {
2991 nr_to_writebump
= desired_nr_to_write
- wbc
->nr_to_write
;
2992 wbc
->nr_to_write
= desired_nr_to_write
;
2996 mpd
.inode
= mapping
->host
;
2998 pages_skipped
= wbc
->pages_skipped
;
3001 while (!ret
&& wbc
->nr_to_write
> 0) {
3004 * we insert one extent at a time. So we need
3005 * credit needed for single extent allocation.
3006 * journalled mode is currently not supported
3009 BUG_ON(ext4_should_journal_data(inode
));
3010 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
3012 /* start a new transaction*/
3013 handle
= ext4_journal_start(inode
, needed_blocks
);
3014 if (IS_ERR(handle
)) {
3015 ret
= PTR_ERR(handle
);
3016 ext4_msg(inode
->i_sb
, KERN_CRIT
, "%s: jbd2_start: "
3017 "%ld pages, ino %lu; err %d", __func__
,
3018 wbc
->nr_to_write
, inode
->i_ino
, ret
);
3019 goto out_writepages
;
3023 * Now call __mpage_da_writepage to find the next
3024 * contiguous region of logical blocks that need
3025 * blocks to be allocated by ext4. We don't actually
3026 * submit the blocks for I/O here, even though
3027 * write_cache_pages thinks it will, and will set the
3028 * pages as clean for write before calling
3029 * __mpage_da_writepage().
3037 mpd
.pages_written
= 0;
3039 ret
= write_cache_pages_da(mapping
, wbc
, &mpd
);
3041 * If we have a contiguous extent of pages and we
3042 * haven't done the I/O yet, map the blocks and submit
3045 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
3046 if (mpage_da_map_blocks(&mpd
) == 0)
3047 mpage_da_submit_io(&mpd
);
3049 ret
= MPAGE_DA_EXTENT_TAIL
;
3051 trace_ext4_da_write_pages(inode
, &mpd
);
3052 wbc
->nr_to_write
-= mpd
.pages_written
;
3054 ext4_journal_stop(handle
);
3056 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
3057 /* commit the transaction which would
3058 * free blocks released in the transaction
3061 jbd2_journal_force_commit_nested(sbi
->s_journal
);
3062 wbc
->pages_skipped
= pages_skipped
;
3064 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
3066 * got one extent now try with
3069 pages_written
+= mpd
.pages_written
;
3070 wbc
->pages_skipped
= pages_skipped
;
3073 } else if (wbc
->nr_to_write
)
3075 * There is no more writeout needed
3076 * or we requested for a noblocking writeout
3077 * and we found the device congested
3081 if (!io_done
&& !cycled
) {
3084 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
3085 wbc
->range_end
= mapping
->writeback_index
- 1;
3088 if (pages_skipped
!= wbc
->pages_skipped
)
3089 ext4_msg(inode
->i_sb
, KERN_CRIT
,
3090 "This should not happen leaving %s "
3091 "with nr_to_write = %ld ret = %d",
3092 __func__
, wbc
->nr_to_write
, ret
);
3095 index
+= pages_written
;
3096 wbc
->range_cyclic
= range_cyclic
;
3097 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
3099 * set the writeback_index so that range_cyclic
3100 * mode will write it back later
3102 mapping
->writeback_index
= index
;
3105 wbc
->nr_to_write
-= nr_to_writebump
;
3106 wbc
->range_start
= range_start
;
3107 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
3111 #define FALL_BACK_TO_NONDELALLOC 1
3112 static int ext4_nonda_switch(struct super_block
*sb
)
3114 s64 free_blocks
, dirty_blocks
;
3115 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3118 * switch to non delalloc mode if we are running low
3119 * on free block. The free block accounting via percpu
3120 * counters can get slightly wrong with percpu_counter_batch getting
3121 * accumulated on each CPU without updating global counters
3122 * Delalloc need an accurate free block accounting. So switch
3123 * to non delalloc when we are near to error range.
3125 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
3126 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
3127 if (2 * free_blocks
< 3 * dirty_blocks
||
3128 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
3130 * free block count is less than 150% of dirty blocks
3131 * or free blocks is less than watermark
3136 * Even if we don't switch but are nearing capacity,
3137 * start pushing delalloc when 1/2 of free blocks are dirty.
3139 if (free_blocks
< 2 * dirty_blocks
)
3140 writeback_inodes_sb_if_idle(sb
);
3145 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
3146 loff_t pos
, unsigned len
, unsigned flags
,
3147 struct page
**pagep
, void **fsdata
)
3149 int ret
, retries
= 0;
3152 struct inode
*inode
= mapping
->host
;
3155 index
= pos
>> PAGE_CACHE_SHIFT
;
3157 if (ext4_nonda_switch(inode
->i_sb
)) {
3158 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
3159 return ext4_write_begin(file
, mapping
, pos
,
3160 len
, flags
, pagep
, fsdata
);
3162 *fsdata
= (void *)0;
3163 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
3166 * With delayed allocation, we don't log the i_disksize update
3167 * if there is delayed block allocation. But we still need
3168 * to journalling the i_disksize update if writes to the end
3169 * of file which has an already mapped buffer.
3171 handle
= ext4_journal_start(inode
, 1);
3172 if (IS_ERR(handle
)) {
3173 ret
= PTR_ERR(handle
);
3176 /* We cannot recurse into the filesystem as the transaction is already
3178 flags
|= AOP_FLAG_NOFS
;
3180 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
3182 ext4_journal_stop(handle
);
3188 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
3189 ext4_da_get_block_prep
);
3192 ext4_journal_stop(handle
);
3193 page_cache_release(page
);
3195 * block_write_begin may have instantiated a few blocks
3196 * outside i_size. Trim these off again. Don't need
3197 * i_size_read because we hold i_mutex.
3199 if (pos
+ len
> inode
->i_size
)
3200 ext4_truncate_failed_write(inode
);
3203 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3210 * Check if we should update i_disksize
3211 * when write to the end of file but not require block allocation
3213 static int ext4_da_should_update_i_disksize(struct page
*page
,
3214 unsigned long offset
)
3216 struct buffer_head
*bh
;
3217 struct inode
*inode
= page
->mapping
->host
;
3221 bh
= page_buffers(page
);
3222 idx
= offset
>> inode
->i_blkbits
;
3224 for (i
= 0; i
< idx
; i
++)
3225 bh
= bh
->b_this_page
;
3227 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
3232 static int ext4_da_write_end(struct file
*file
,
3233 struct address_space
*mapping
,
3234 loff_t pos
, unsigned len
, unsigned copied
,
3235 struct page
*page
, void *fsdata
)
3237 struct inode
*inode
= mapping
->host
;
3239 handle_t
*handle
= ext4_journal_current_handle();
3241 unsigned long start
, end
;
3242 int write_mode
= (int)(unsigned long)fsdata
;
3244 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
3245 if (ext4_should_order_data(inode
)) {
3246 return ext4_ordered_write_end(file
, mapping
, pos
,
3247 len
, copied
, page
, fsdata
);
3248 } else if (ext4_should_writeback_data(inode
)) {
3249 return ext4_writeback_write_end(file
, mapping
, pos
,
3250 len
, copied
, page
, fsdata
);
3256 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
3257 start
= pos
& (PAGE_CACHE_SIZE
- 1);
3258 end
= start
+ copied
- 1;
3261 * generic_write_end() will run mark_inode_dirty() if i_size
3262 * changes. So let's piggyback the i_disksize mark_inode_dirty
3266 new_i_size
= pos
+ copied
;
3267 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3268 if (ext4_da_should_update_i_disksize(page
, end
)) {
3269 down_write(&EXT4_I(inode
)->i_data_sem
);
3270 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3272 * Updating i_disksize when extending file
3273 * without needing block allocation
3275 if (ext4_should_order_data(inode
))
3276 ret
= ext4_jbd2_file_inode(handle
,
3279 EXT4_I(inode
)->i_disksize
= new_i_size
;
3281 up_write(&EXT4_I(inode
)->i_data_sem
);
3282 /* We need to mark inode dirty even if
3283 * new_i_size is less that inode->i_size
3284 * bu greater than i_disksize.(hint delalloc)
3286 ext4_mark_inode_dirty(handle
, inode
);
3289 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
3294 ret2
= ext4_journal_stop(handle
);
3298 return ret
? ret
: copied
;
3301 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
3304 * Drop reserved blocks
3306 BUG_ON(!PageLocked(page
));
3307 if (!page_has_buffers(page
))
3310 ext4_da_page_release_reservation(page
, offset
);
3313 ext4_invalidatepage(page
, offset
);
3319 * Force all delayed allocation blocks to be allocated for a given inode.
3321 int ext4_alloc_da_blocks(struct inode
*inode
)
3323 trace_ext4_alloc_da_blocks(inode
);
3325 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
3326 !EXT4_I(inode
)->i_reserved_meta_blocks
)
3330 * We do something simple for now. The filemap_flush() will
3331 * also start triggering a write of the data blocks, which is
3332 * not strictly speaking necessary (and for users of
3333 * laptop_mode, not even desirable). However, to do otherwise
3334 * would require replicating code paths in:
3336 * ext4_da_writepages() ->
3337 * write_cache_pages() ---> (via passed in callback function)
3338 * __mpage_da_writepage() -->
3339 * mpage_add_bh_to_extent()
3340 * mpage_da_map_blocks()
3342 * The problem is that write_cache_pages(), located in
3343 * mm/page-writeback.c, marks pages clean in preparation for
3344 * doing I/O, which is not desirable if we're not planning on
3347 * We could call write_cache_pages(), and then redirty all of
3348 * the pages by calling redirty_page_for_writeback() but that
3349 * would be ugly in the extreme. So instead we would need to
3350 * replicate parts of the code in the above functions,
3351 * simplifying them becuase we wouldn't actually intend to
3352 * write out the pages, but rather only collect contiguous
3353 * logical block extents, call the multi-block allocator, and
3354 * then update the buffer heads with the block allocations.
3356 * For now, though, we'll cheat by calling filemap_flush(),
3357 * which will map the blocks, and start the I/O, but not
3358 * actually wait for the I/O to complete.
3360 return filemap_flush(inode
->i_mapping
);
3364 * bmap() is special. It gets used by applications such as lilo and by
3365 * the swapper to find the on-disk block of a specific piece of data.
3367 * Naturally, this is dangerous if the block concerned is still in the
3368 * journal. If somebody makes a swapfile on an ext4 data-journaling
3369 * filesystem and enables swap, then they may get a nasty shock when the
3370 * data getting swapped to that swapfile suddenly gets overwritten by
3371 * the original zero's written out previously to the journal and
3372 * awaiting writeback in the kernel's buffer cache.
3374 * So, if we see any bmap calls here on a modified, data-journaled file,
3375 * take extra steps to flush any blocks which might be in the cache.
3377 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
3379 struct inode
*inode
= mapping
->host
;
3383 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
3384 test_opt(inode
->i_sb
, DELALLOC
)) {
3386 * With delalloc we want to sync the file
3387 * so that we can make sure we allocate
3390 filemap_write_and_wait(mapping
);
3393 if (EXT4_JOURNAL(inode
) &&
3394 ext4_test_inode_state(inode
, EXT4_STATE_JDATA
)) {
3396 * This is a REALLY heavyweight approach, but the use of
3397 * bmap on dirty files is expected to be extremely rare:
3398 * only if we run lilo or swapon on a freshly made file
3399 * do we expect this to happen.
3401 * (bmap requires CAP_SYS_RAWIO so this does not
3402 * represent an unprivileged user DOS attack --- we'd be
3403 * in trouble if mortal users could trigger this path at
3406 * NB. EXT4_STATE_JDATA is not set on files other than
3407 * regular files. If somebody wants to bmap a directory
3408 * or symlink and gets confused because the buffer
3409 * hasn't yet been flushed to disk, they deserve
3410 * everything they get.
3413 ext4_clear_inode_state(inode
, EXT4_STATE_JDATA
);
3414 journal
= EXT4_JOURNAL(inode
);
3415 jbd2_journal_lock_updates(journal
);
3416 err
= jbd2_journal_flush(journal
);
3417 jbd2_journal_unlock_updates(journal
);
3423 return generic_block_bmap(mapping
, block
, ext4_get_block
);
3426 static int ext4_readpage(struct file
*file
, struct page
*page
)
3428 return mpage_readpage(page
, ext4_get_block
);
3432 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3433 struct list_head
*pages
, unsigned nr_pages
)
3435 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3438 static void ext4_free_io_end(ext4_io_end_t
*io
)
3447 static void ext4_invalidatepage_free_endio(struct page
*page
, unsigned long offset
)
3449 struct buffer_head
*head
, *bh
;
3450 unsigned int curr_off
= 0;
3452 if (!page_has_buffers(page
))
3454 head
= bh
= page_buffers(page
);
3456 if (offset
<= curr_off
&& test_clear_buffer_uninit(bh
)
3458 ext4_free_io_end(bh
->b_private
);
3459 bh
->b_private
= NULL
;
3460 bh
->b_end_io
= NULL
;
3462 curr_off
= curr_off
+ bh
->b_size
;
3463 bh
= bh
->b_this_page
;
3464 } while (bh
!= head
);
3467 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3469 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3472 * free any io_end structure allocated for buffers to be discarded
3474 if (ext4_should_dioread_nolock(page
->mapping
->host
))
3475 ext4_invalidatepage_free_endio(page
, offset
);
3477 * If it's a full truncate we just forget about the pending dirtying
3480 ClearPageChecked(page
);
3483 jbd2_journal_invalidatepage(journal
, page
, offset
);
3485 block_invalidatepage(page
, offset
);
3488 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3490 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3492 WARN_ON(PageChecked(page
));
3493 if (!page_has_buffers(page
))
3496 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3498 return try_to_free_buffers(page
);
3502 * O_DIRECT for ext3 (or indirect map) based files
3504 * If the O_DIRECT write will extend the file then add this inode to the
3505 * orphan list. So recovery will truncate it back to the original size
3506 * if the machine crashes during the write.
3508 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3509 * crashes then stale disk data _may_ be exposed inside the file. But current
3510 * VFS code falls back into buffered path in that case so we are safe.
3512 static ssize_t
ext4_ind_direct_IO(int rw
, struct kiocb
*iocb
,
3513 const struct iovec
*iov
, loff_t offset
,
3514 unsigned long nr_segs
)
3516 struct file
*file
= iocb
->ki_filp
;
3517 struct inode
*inode
= file
->f_mapping
->host
;
3518 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3522 size_t count
= iov_length(iov
, nr_segs
);
3526 loff_t final_size
= offset
+ count
;
3528 if (final_size
> inode
->i_size
) {
3529 /* Credits for sb + inode write */
3530 handle
= ext4_journal_start(inode
, 2);
3531 if (IS_ERR(handle
)) {
3532 ret
= PTR_ERR(handle
);
3535 ret
= ext4_orphan_add(handle
, inode
);
3537 ext4_journal_stop(handle
);
3541 ei
->i_disksize
= inode
->i_size
;
3542 ext4_journal_stop(handle
);
3547 if (rw
== READ
&& ext4_should_dioread_nolock(inode
))
3548 ret
= blockdev_direct_IO_no_locking(rw
, iocb
, inode
,
3549 inode
->i_sb
->s_bdev
, iov
,
3551 ext4_get_block
, NULL
);
3553 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3554 inode
->i_sb
->s_bdev
, iov
,
3556 ext4_get_block
, NULL
);
3557 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3563 /* Credits for sb + inode write */
3564 handle
= ext4_journal_start(inode
, 2);
3565 if (IS_ERR(handle
)) {
3566 /* This is really bad luck. We've written the data
3567 * but cannot extend i_size. Bail out and pretend
3568 * the write failed... */
3569 ret
= PTR_ERR(handle
);
3571 ext4_orphan_del(NULL
, inode
);
3576 ext4_orphan_del(handle
, inode
);
3578 loff_t end
= offset
+ ret
;
3579 if (end
> inode
->i_size
) {
3580 ei
->i_disksize
= end
;
3581 i_size_write(inode
, end
);
3583 * We're going to return a positive `ret'
3584 * here due to non-zero-length I/O, so there's
3585 * no way of reporting error returns from
3586 * ext4_mark_inode_dirty() to userspace. So
3589 ext4_mark_inode_dirty(handle
, inode
);
3592 err
= ext4_journal_stop(handle
);
3601 * ext4_get_block used when preparing for a DIO write or buffer write.
3602 * We allocate an uinitialized extent if blocks haven't been allocated.
3603 * The extent will be converted to initialized after the IO is complete.
3605 static int ext4_get_block_write(struct inode
*inode
, sector_t iblock
,
3606 struct buffer_head
*bh_result
, int create
)
3608 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
3609 inode
->i_ino
, create
);
3610 return _ext4_get_block(inode
, iblock
, bh_result
,
3611 EXT4_GET_BLOCKS_IO_CREATE_EXT
);
3614 static void dump_completed_IO(struct inode
* inode
)
3617 struct list_head
*cur
, *before
, *after
;
3618 ext4_io_end_t
*io
, *io0
, *io1
;
3619 unsigned long flags
;
3621 if (list_empty(&EXT4_I(inode
)->i_completed_io_list
)){
3622 ext4_debug("inode %lu completed_io list is empty\n", inode
->i_ino
);
3626 ext4_debug("Dump inode %lu completed_io list \n", inode
->i_ino
);
3627 spin_lock_irqsave(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3628 list_for_each_entry(io
, &EXT4_I(inode
)->i_completed_io_list
, list
){
3631 io0
= container_of(before
, ext4_io_end_t
, list
);
3633 io1
= container_of(after
, ext4_io_end_t
, list
);
3635 ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
3636 io
, inode
->i_ino
, io0
, io1
);
3638 spin_unlock_irqrestore(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3643 * check a range of space and convert unwritten extents to written.
3645 static int ext4_end_io_nolock(ext4_io_end_t
*io
)
3647 struct inode
*inode
= io
->inode
;
3648 loff_t offset
= io
->offset
;
3649 ssize_t size
= io
->size
;
3652 ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
3653 "list->prev 0x%p\n",
3654 io
, inode
->i_ino
, io
->list
.next
, io
->list
.prev
);
3656 if (list_empty(&io
->list
))
3659 if (io
->flag
!= EXT4_IO_UNWRITTEN
)
3662 ret
= ext4_convert_unwritten_extents(inode
, offset
, size
);
3664 printk(KERN_EMERG
"%s: failed to convert unwritten"
3665 "extents to written extents, error is %d"
3666 " io is still on inode %lu aio dio list\n",
3667 __func__
, ret
, inode
->i_ino
);
3672 aio_complete(io
->iocb
, io
->result
, 0);
3673 /* clear the DIO AIO unwritten flag */
3679 * work on completed aio dio IO, to convert unwritten extents to extents
3681 static void ext4_end_io_work(struct work_struct
*work
)
3683 ext4_io_end_t
*io
= container_of(work
, ext4_io_end_t
, work
);
3684 struct inode
*inode
= io
->inode
;
3685 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3686 unsigned long flags
;
3689 mutex_lock(&inode
->i_mutex
);
3690 ret
= ext4_end_io_nolock(io
);
3692 mutex_unlock(&inode
->i_mutex
);
3696 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3697 if (!list_empty(&io
->list
))
3698 list_del_init(&io
->list
);
3699 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3700 mutex_unlock(&inode
->i_mutex
);
3701 ext4_free_io_end(io
);
3705 * This function is called from ext4_sync_file().
3707 * When IO is completed, the work to convert unwritten extents to
3708 * written is queued on workqueue but may not get immediately
3709 * scheduled. When fsync is called, we need to ensure the
3710 * conversion is complete before fsync returns.
3711 * The inode keeps track of a list of pending/completed IO that
3712 * might needs to do the conversion. This function walks through
3713 * the list and convert the related unwritten extents for completed IO
3715 * The function return the number of pending IOs on success.
3717 int flush_completed_IO(struct inode
*inode
)
3720 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3721 unsigned long flags
;
3725 if (list_empty(&ei
->i_completed_io_list
))
3728 dump_completed_IO(inode
);
3729 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3730 while (!list_empty(&ei
->i_completed_io_list
)){
3731 io
= list_entry(ei
->i_completed_io_list
.next
,
3732 ext4_io_end_t
, list
);
3734 * Calling ext4_end_io_nolock() to convert completed
3737 * When ext4_sync_file() is called, run_queue() may already
3738 * about to flush the work corresponding to this io structure.
3739 * It will be upset if it founds the io structure related
3740 * to the work-to-be schedule is freed.
3742 * Thus we need to keep the io structure still valid here after
3743 * convertion finished. The io structure has a flag to
3744 * avoid double converting from both fsync and background work
3747 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3748 ret
= ext4_end_io_nolock(io
);
3749 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3753 list_del_init(&io
->list
);
3755 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3756 return (ret2
< 0) ? ret2
: 0;
3759 static ext4_io_end_t
*ext4_init_io_end (struct inode
*inode
, gfp_t flags
)
3761 ext4_io_end_t
*io
= NULL
;
3763 io
= kmalloc(sizeof(*io
), flags
);
3774 INIT_WORK(&io
->work
, ext4_end_io_work
);
3775 INIT_LIST_HEAD(&io
->list
);
3781 static void ext4_end_io_dio(struct kiocb
*iocb
, loff_t offset
,
3782 ssize_t size
, void *private, int ret
,
3785 ext4_io_end_t
*io_end
= iocb
->private;
3786 struct workqueue_struct
*wq
;
3787 unsigned long flags
;
3788 struct ext4_inode_info
*ei
;
3790 /* if not async direct IO or dio with 0 bytes write, just return */
3791 if (!io_end
|| !size
)
3794 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3795 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3796 iocb
->private, io_end
->inode
->i_ino
, iocb
, offset
,
3799 /* if not aio dio with unwritten extents, just free io and return */
3800 if (io_end
->flag
!= EXT4_IO_UNWRITTEN
){
3801 ext4_free_io_end(io_end
);
3802 iocb
->private = NULL
;
3805 aio_complete(iocb
, ret
, 0);
3809 io_end
->offset
= offset
;
3810 io_end
->size
= size
;
3812 io_end
->iocb
= iocb
;
3813 io_end
->result
= ret
;
3815 wq
= EXT4_SB(io_end
->inode
->i_sb
)->dio_unwritten_wq
;
3817 /* queue the work to convert unwritten extents to written */
3818 queue_work(wq
, &io_end
->work
);
3820 /* Add the io_end to per-inode completed aio dio list*/
3821 ei
= EXT4_I(io_end
->inode
);
3822 spin_lock_irqsave(&ei
->i_completed_io_lock
, flags
);
3823 list_add_tail(&io_end
->list
, &ei
->i_completed_io_list
);
3824 spin_unlock_irqrestore(&ei
->i_completed_io_lock
, flags
);
3825 iocb
->private = NULL
;
3828 static void ext4_end_io_buffer_write(struct buffer_head
*bh
, int uptodate
)
3830 ext4_io_end_t
*io_end
= bh
->b_private
;
3831 struct workqueue_struct
*wq
;
3832 struct inode
*inode
;
3833 unsigned long flags
;
3835 if (!test_clear_buffer_uninit(bh
) || !io_end
)
3838 if (!(io_end
->inode
->i_sb
->s_flags
& MS_ACTIVE
)) {
3839 printk("sb umounted, discard end_io request for inode %lu\n",
3840 io_end
->inode
->i_ino
);
3841 ext4_free_io_end(io_end
);
3845 io_end
->flag
= EXT4_IO_UNWRITTEN
;
3846 inode
= io_end
->inode
;
3848 /* Add the io_end to per-inode completed io list*/
3849 spin_lock_irqsave(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3850 list_add_tail(&io_end
->list
, &EXT4_I(inode
)->i_completed_io_list
);
3851 spin_unlock_irqrestore(&EXT4_I(inode
)->i_completed_io_lock
, flags
);
3853 wq
= EXT4_SB(inode
->i_sb
)->dio_unwritten_wq
;
3854 /* queue the work to convert unwritten extents to written */
3855 queue_work(wq
, &io_end
->work
);
3857 bh
->b_private
= NULL
;
3858 bh
->b_end_io
= NULL
;
3859 clear_buffer_uninit(bh
);
3860 end_buffer_async_write(bh
, uptodate
);
3863 static int ext4_set_bh_endio(struct buffer_head
*bh
, struct inode
*inode
)
3865 ext4_io_end_t
*io_end
;
3866 struct page
*page
= bh
->b_page
;
3867 loff_t offset
= (sector_t
)page
->index
<< PAGE_CACHE_SHIFT
;
3868 size_t size
= bh
->b_size
;
3871 io_end
= ext4_init_io_end(inode
, GFP_ATOMIC
);
3873 if (printk_ratelimit())
3874 printk(KERN_WARNING
"%s: allocation fail\n", __func__
);
3878 io_end
->offset
= offset
;
3879 io_end
->size
= size
;
3881 * We need to hold a reference to the page to make sure it
3882 * doesn't get evicted before ext4_end_io_work() has a chance
3883 * to convert the extent from written to unwritten.
3885 io_end
->page
= page
;
3886 get_page(io_end
->page
);
3888 bh
->b_private
= io_end
;
3889 bh
->b_end_io
= ext4_end_io_buffer_write
;
3894 * For ext4 extent files, ext4 will do direct-io write to holes,
3895 * preallocated extents, and those write extend the file, no need to
3896 * fall back to buffered IO.
3898 * For holes, we fallocate those blocks, mark them as unintialized
3899 * If those blocks were preallocated, we mark sure they are splited, but
3900 * still keep the range to write as unintialized.
3902 * The unwrritten extents will be converted to written when DIO is completed.
3903 * For async direct IO, since the IO may still pending when return, we
3904 * set up an end_io call back function, which will do the convertion
3905 * when async direct IO completed.
3907 * If the O_DIRECT write will extend the file then add this inode to the
3908 * orphan list. So recovery will truncate it back to the original size
3909 * if the machine crashes during the write.
3912 static ssize_t
ext4_ext_direct_IO(int rw
, struct kiocb
*iocb
,
3913 const struct iovec
*iov
, loff_t offset
,
3914 unsigned long nr_segs
)
3916 struct file
*file
= iocb
->ki_filp
;
3917 struct inode
*inode
= file
->f_mapping
->host
;
3919 size_t count
= iov_length(iov
, nr_segs
);
3921 loff_t final_size
= offset
+ count
;
3922 if (rw
== WRITE
&& final_size
<= inode
->i_size
) {
3924 * We could direct write to holes and fallocate.
3926 * Allocated blocks to fill the hole are marked as uninitialized
3927 * to prevent paralel buffered read to expose the stale data
3928 * before DIO complete the data IO.
3930 * As to previously fallocated extents, ext4 get_block
3931 * will just simply mark the buffer mapped but still
3932 * keep the extents uninitialized.
3934 * for non AIO case, we will convert those unwritten extents
3935 * to written after return back from blockdev_direct_IO.
3937 * for async DIO, the conversion needs to be defered when
3938 * the IO is completed. The ext4 end_io callback function
3939 * will be called to take care of the conversion work.
3940 * Here for async case, we allocate an io_end structure to
3943 iocb
->private = NULL
;
3944 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3945 if (!is_sync_kiocb(iocb
)) {
3946 iocb
->private = ext4_init_io_end(inode
, GFP_NOFS
);
3950 * we save the io structure for current async
3951 * direct IO, so that later ext4_map_blocks()
3952 * could flag the io structure whether there
3953 * is a unwritten extents needs to be converted
3954 * when IO is completed.
3956 EXT4_I(inode
)->cur_aio_dio
= iocb
->private;
3959 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3960 inode
->i_sb
->s_bdev
, iov
,
3962 ext4_get_block_write
,
3965 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3967 * The io_end structure takes a reference to the inode,
3968 * that structure needs to be destroyed and the
3969 * reference to the inode need to be dropped, when IO is
3970 * complete, even with 0 byte write, or failed.
3972 * In the successful AIO DIO case, the io_end structure will be
3973 * desctroyed and the reference to the inode will be dropped
3974 * after the end_io call back function is called.
3976 * In the case there is 0 byte write, or error case, since
3977 * VFS direct IO won't invoke the end_io call back function,
3978 * we need to free the end_io structure here.
3980 if (ret
!= -EIOCBQUEUED
&& ret
<= 0 && iocb
->private) {
3981 ext4_free_io_end(iocb
->private);
3982 iocb
->private = NULL
;
3983 } else if (ret
> 0 && ext4_test_inode_state(inode
,
3984 EXT4_STATE_DIO_UNWRITTEN
)) {
3987 * for non AIO case, since the IO is already
3988 * completed, we could do the convertion right here
3990 err
= ext4_convert_unwritten_extents(inode
,
3994 ext4_clear_inode_state(inode
, EXT4_STATE_DIO_UNWRITTEN
);
3999 /* for write the the end of file case, we fall back to old way */
4000 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
4003 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
4004 const struct iovec
*iov
, loff_t offset
,
4005 unsigned long nr_segs
)
4007 struct file
*file
= iocb
->ki_filp
;
4008 struct inode
*inode
= file
->f_mapping
->host
;
4010 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))
4011 return ext4_ext_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
4013 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
4017 * Pages can be marked dirty completely asynchronously from ext4's journalling
4018 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
4019 * much here because ->set_page_dirty is called under VFS locks. The page is
4020 * not necessarily locked.
4022 * We cannot just dirty the page and leave attached buffers clean, because the
4023 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
4024 * or jbddirty because all the journalling code will explode.
4026 * So what we do is to mark the page "pending dirty" and next time writepage
4027 * is called, propagate that into the buffers appropriately.
4029 static int ext4_journalled_set_page_dirty(struct page
*page
)
4031 SetPageChecked(page
);
4032 return __set_page_dirty_nobuffers(page
);
4035 static const struct address_space_operations ext4_ordered_aops
= {
4036 .readpage
= ext4_readpage
,
4037 .readpages
= ext4_readpages
,
4038 .writepage
= ext4_writepage
,
4039 .sync_page
= block_sync_page
,
4040 .write_begin
= ext4_write_begin
,
4041 .write_end
= ext4_ordered_write_end
,
4043 .invalidatepage
= ext4_invalidatepage
,
4044 .releasepage
= ext4_releasepage
,
4045 .direct_IO
= ext4_direct_IO
,
4046 .migratepage
= buffer_migrate_page
,
4047 .is_partially_uptodate
= block_is_partially_uptodate
,
4048 .error_remove_page
= generic_error_remove_page
,
4051 static const struct address_space_operations ext4_writeback_aops
= {
4052 .readpage
= ext4_readpage
,
4053 .readpages
= ext4_readpages
,
4054 .writepage
= ext4_writepage
,
4055 .sync_page
= block_sync_page
,
4056 .write_begin
= ext4_write_begin
,
4057 .write_end
= ext4_writeback_write_end
,
4059 .invalidatepage
= ext4_invalidatepage
,
4060 .releasepage
= ext4_releasepage
,
4061 .direct_IO
= ext4_direct_IO
,
4062 .migratepage
= buffer_migrate_page
,
4063 .is_partially_uptodate
= block_is_partially_uptodate
,
4064 .error_remove_page
= generic_error_remove_page
,
4067 static const struct address_space_operations ext4_journalled_aops
= {
4068 .readpage
= ext4_readpage
,
4069 .readpages
= ext4_readpages
,
4070 .writepage
= ext4_writepage
,
4071 .sync_page
= block_sync_page
,
4072 .write_begin
= ext4_write_begin
,
4073 .write_end
= ext4_journalled_write_end
,
4074 .set_page_dirty
= ext4_journalled_set_page_dirty
,
4076 .invalidatepage
= ext4_invalidatepage
,
4077 .releasepage
= ext4_releasepage
,
4078 .is_partially_uptodate
= block_is_partially_uptodate
,
4079 .error_remove_page
= generic_error_remove_page
,
4082 static const struct address_space_operations ext4_da_aops
= {
4083 .readpage
= ext4_readpage
,
4084 .readpages
= ext4_readpages
,
4085 .writepage
= ext4_writepage
,
4086 .writepages
= ext4_da_writepages
,
4087 .sync_page
= block_sync_page
,
4088 .write_begin
= ext4_da_write_begin
,
4089 .write_end
= ext4_da_write_end
,
4091 .invalidatepage
= ext4_da_invalidatepage
,
4092 .releasepage
= ext4_releasepage
,
4093 .direct_IO
= ext4_direct_IO
,
4094 .migratepage
= buffer_migrate_page
,
4095 .is_partially_uptodate
= block_is_partially_uptodate
,
4096 .error_remove_page
= generic_error_remove_page
,
4099 void ext4_set_aops(struct inode
*inode
)
4101 if (ext4_should_order_data(inode
) &&
4102 test_opt(inode
->i_sb
, DELALLOC
))
4103 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
4104 else if (ext4_should_order_data(inode
))
4105 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
4106 else if (ext4_should_writeback_data(inode
) &&
4107 test_opt(inode
->i_sb
, DELALLOC
))
4108 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
4109 else if (ext4_should_writeback_data(inode
))
4110 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
4112 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
4116 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
4117 * up to the end of the block which corresponds to `from'.
4118 * This required during truncate. We need to physically zero the tail end
4119 * of that block so it doesn't yield old data if the file is later grown.
4121 int ext4_block_truncate_page(handle_t
*handle
,
4122 struct address_space
*mapping
, loff_t from
)
4124 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
4125 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
4126 unsigned blocksize
, length
, pos
;
4128 struct inode
*inode
= mapping
->host
;
4129 struct buffer_head
*bh
;
4133 page
= find_or_create_page(mapping
, from
>> PAGE_CACHE_SHIFT
,
4134 mapping_gfp_mask(mapping
) & ~__GFP_FS
);
4138 blocksize
= inode
->i_sb
->s_blocksize
;
4139 length
= blocksize
- (offset
& (blocksize
- 1));
4140 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
4142 if (!page_has_buffers(page
))
4143 create_empty_buffers(page
, blocksize
, 0);
4145 /* Find the buffer that contains "offset" */
4146 bh
= page_buffers(page
);
4148 while (offset
>= pos
) {
4149 bh
= bh
->b_this_page
;
4155 if (buffer_freed(bh
)) {
4156 BUFFER_TRACE(bh
, "freed: skip");
4160 if (!buffer_mapped(bh
)) {
4161 BUFFER_TRACE(bh
, "unmapped");
4162 ext4_get_block(inode
, iblock
, bh
, 0);
4163 /* unmapped? It's a hole - nothing to do */
4164 if (!buffer_mapped(bh
)) {
4165 BUFFER_TRACE(bh
, "still unmapped");
4170 /* Ok, it's mapped. Make sure it's up-to-date */
4171 if (PageUptodate(page
))
4172 set_buffer_uptodate(bh
);
4174 if (!buffer_uptodate(bh
)) {
4176 ll_rw_block(READ
, 1, &bh
);
4178 /* Uhhuh. Read error. Complain and punt. */
4179 if (!buffer_uptodate(bh
))
4183 if (ext4_should_journal_data(inode
)) {
4184 BUFFER_TRACE(bh
, "get write access");
4185 err
= ext4_journal_get_write_access(handle
, bh
);
4190 zero_user(page
, offset
, length
);
4192 BUFFER_TRACE(bh
, "zeroed end of block");
4195 if (ext4_should_journal_data(inode
)) {
4196 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
4198 if (ext4_should_order_data(inode
))
4199 err
= ext4_jbd2_file_inode(handle
, inode
);
4200 mark_buffer_dirty(bh
);
4205 page_cache_release(page
);
4210 * Probably it should be a library function... search for first non-zero word
4211 * or memcmp with zero_page, whatever is better for particular architecture.
4214 static inline int all_zeroes(__le32
*p
, __le32
*q
)
4223 * ext4_find_shared - find the indirect blocks for partial truncation.
4224 * @inode: inode in question
4225 * @depth: depth of the affected branch
4226 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4227 * @chain: place to store the pointers to partial indirect blocks
4228 * @top: place to the (detached) top of branch
4230 * This is a helper function used by ext4_truncate().
4232 * When we do truncate() we may have to clean the ends of several
4233 * indirect blocks but leave the blocks themselves alive. Block is
4234 * partially truncated if some data below the new i_size is refered
4235 * from it (and it is on the path to the first completely truncated
4236 * data block, indeed). We have to free the top of that path along
4237 * with everything to the right of the path. Since no allocation
4238 * past the truncation point is possible until ext4_truncate()
4239 * finishes, we may safely do the latter, but top of branch may
4240 * require special attention - pageout below the truncation point
4241 * might try to populate it.
4243 * We atomically detach the top of branch from the tree, store the
4244 * block number of its root in *@top, pointers to buffer_heads of
4245 * partially truncated blocks - in @chain[].bh and pointers to
4246 * their last elements that should not be removed - in
4247 * @chain[].p. Return value is the pointer to last filled element
4250 * The work left to caller to do the actual freeing of subtrees:
4251 * a) free the subtree starting from *@top
4252 * b) free the subtrees whose roots are stored in
4253 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4254 * c) free the subtrees growing from the inode past the @chain[0].
4255 * (no partially truncated stuff there). */
4257 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
4258 ext4_lblk_t offsets
[4], Indirect chain
[4],
4261 Indirect
*partial
, *p
;
4265 /* Make k index the deepest non-null offset + 1 */
4266 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
4268 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
4269 /* Writer: pointers */
4271 partial
= chain
+ k
-1;
4273 * If the branch acquired continuation since we've looked at it -
4274 * fine, it should all survive and (new) top doesn't belong to us.
4276 if (!partial
->key
&& *partial
->p
)
4279 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
4282 * OK, we've found the last block that must survive. The rest of our
4283 * branch should be detached before unlocking. However, if that rest
4284 * of branch is all ours and does not grow immediately from the inode
4285 * it's easier to cheat and just decrement partial->p.
4287 if (p
== chain
+ k
- 1 && p
> chain
) {
4291 /* Nope, don't do this in ext4. Must leave the tree intact */
4298 while (partial
> p
) {
4299 brelse(partial
->bh
);
4307 * Zero a number of block pointers in either an inode or an indirect block.
4308 * If we restart the transaction we must again get write access to the
4309 * indirect block for further modification.
4311 * We release `count' blocks on disk, but (last - first) may be greater
4312 * than `count' because there can be holes in there.
4314 static int ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
4315 struct buffer_head
*bh
,
4316 ext4_fsblk_t block_to_free
,
4317 unsigned long count
, __le32
*first
,
4321 int flags
= EXT4_FREE_BLOCKS_FORGET
| EXT4_FREE_BLOCKS_VALIDATED
;
4323 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
4324 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4326 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), block_to_free
,
4328 EXT4_ERROR_INODE(inode
, "attempt to clear invalid "
4329 "blocks %llu len %lu",
4330 (unsigned long long) block_to_free
, count
);
4334 if (try_to_extend_transaction(handle
, inode
)) {
4336 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4337 ext4_handle_dirty_metadata(handle
, inode
, bh
);
4339 ext4_mark_inode_dirty(handle
, inode
);
4340 ext4_truncate_restart_trans(handle
, inode
,
4341 blocks_for_truncate(inode
));
4343 BUFFER_TRACE(bh
, "retaking write access");
4344 ext4_journal_get_write_access(handle
, bh
);
4348 for (p
= first
; p
< last
; p
++)
4351 ext4_free_blocks(handle
, inode
, 0, block_to_free
, count
, flags
);
4356 * ext4_free_data - free a list of data blocks
4357 * @handle: handle for this transaction
4358 * @inode: inode we are dealing with
4359 * @this_bh: indirect buffer_head which contains *@first and *@last
4360 * @first: array of block numbers
4361 * @last: points immediately past the end of array
4363 * We are freeing all blocks refered from that array (numbers are stored as
4364 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4366 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4367 * blocks are contiguous then releasing them at one time will only affect one
4368 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4369 * actually use a lot of journal space.
4371 * @this_bh will be %NULL if @first and @last point into the inode's direct
4374 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
4375 struct buffer_head
*this_bh
,
4376 __le32
*first
, __le32
*last
)
4378 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
4379 unsigned long count
= 0; /* Number of blocks in the run */
4380 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
4383 ext4_fsblk_t nr
; /* Current block # */
4384 __le32
*p
; /* Pointer into inode/ind
4385 for current block */
4388 if (this_bh
) { /* For indirect block */
4389 BUFFER_TRACE(this_bh
, "get_write_access");
4390 err
= ext4_journal_get_write_access(handle
, this_bh
);
4391 /* Important: if we can't update the indirect pointers
4392 * to the blocks, we can't free them. */
4397 for (p
= first
; p
< last
; p
++) {
4398 nr
= le32_to_cpu(*p
);
4400 /* accumulate blocks to free if they're contiguous */
4403 block_to_free_p
= p
;
4405 } else if (nr
== block_to_free
+ count
) {
4408 if (ext4_clear_blocks(handle
, inode
, this_bh
,
4409 block_to_free
, count
,
4410 block_to_free_p
, p
))
4413 block_to_free_p
= p
;
4420 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
4421 count
, block_to_free_p
, p
);
4424 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
4427 * The buffer head should have an attached journal head at this
4428 * point. However, if the data is corrupted and an indirect
4429 * block pointed to itself, it would have been detached when
4430 * the block was cleared. Check for this instead of OOPSing.
4432 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
4433 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
4435 EXT4_ERROR_INODE(inode
,
4436 "circular indirect block detected at "
4438 (unsigned long long) this_bh
->b_blocknr
);
4443 * ext4_free_branches - free an array of branches
4444 * @handle: JBD handle for this transaction
4445 * @inode: inode we are dealing with
4446 * @parent_bh: the buffer_head which contains *@first and *@last
4447 * @first: array of block numbers
4448 * @last: pointer immediately past the end of array
4449 * @depth: depth of the branches to free
4451 * We are freeing all blocks refered from these branches (numbers are
4452 * stored as little-endian 32-bit) and updating @inode->i_blocks
4455 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
4456 struct buffer_head
*parent_bh
,
4457 __le32
*first
, __le32
*last
, int depth
)
4462 if (ext4_handle_is_aborted(handle
))
4466 struct buffer_head
*bh
;
4467 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4469 while (--p
>= first
) {
4470 nr
= le32_to_cpu(*p
);
4472 continue; /* A hole */
4474 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
),
4476 EXT4_ERROR_INODE(inode
,
4477 "invalid indirect mapped "
4478 "block %lu (level %d)",
4479 (unsigned long) nr
, depth
);
4483 /* Go read the buffer for the next level down */
4484 bh
= sb_bread(inode
->i_sb
, nr
);
4487 * A read failure? Report error and clear slot
4491 EXT4_ERROR_INODE_BLOCK(inode
, nr
,
4496 /* This zaps the entire block. Bottom up. */
4497 BUFFER_TRACE(bh
, "free child branches");
4498 ext4_free_branches(handle
, inode
, bh
,
4499 (__le32
*) bh
->b_data
,
4500 (__le32
*) bh
->b_data
+ addr_per_block
,
4504 * Everything below this this pointer has been
4505 * released. Now let this top-of-subtree go.
4507 * We want the freeing of this indirect block to be
4508 * atomic in the journal with the updating of the
4509 * bitmap block which owns it. So make some room in
4512 * We zero the parent pointer *after* freeing its
4513 * pointee in the bitmaps, so if extend_transaction()
4514 * for some reason fails to put the bitmap changes and
4515 * the release into the same transaction, recovery
4516 * will merely complain about releasing a free block,
4517 * rather than leaking blocks.
4519 if (ext4_handle_is_aborted(handle
))
4521 if (try_to_extend_transaction(handle
, inode
)) {
4522 ext4_mark_inode_dirty(handle
, inode
);
4523 ext4_truncate_restart_trans(handle
, inode
,
4524 blocks_for_truncate(inode
));
4528 * The forget flag here is critical because if
4529 * we are journaling (and not doing data
4530 * journaling), we have to make sure a revoke
4531 * record is written to prevent the journal
4532 * replay from overwriting the (former)
4533 * indirect block if it gets reallocated as a
4534 * data block. This must happen in the same
4535 * transaction where the data blocks are
4538 ext4_free_blocks(handle
, inode
, 0, nr
, 1,
4539 EXT4_FREE_BLOCKS_METADATA
|
4540 EXT4_FREE_BLOCKS_FORGET
);
4544 * The block which we have just freed is
4545 * pointed to by an indirect block: journal it
4547 BUFFER_TRACE(parent_bh
, "get_write_access");
4548 if (!ext4_journal_get_write_access(handle
,
4551 BUFFER_TRACE(parent_bh
,
4552 "call ext4_handle_dirty_metadata");
4553 ext4_handle_dirty_metadata(handle
,
4560 /* We have reached the bottom of the tree. */
4561 BUFFER_TRACE(parent_bh
, "free data blocks");
4562 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
4566 int ext4_can_truncate(struct inode
*inode
)
4568 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
4570 if (S_ISREG(inode
->i_mode
))
4572 if (S_ISDIR(inode
->i_mode
))
4574 if (S_ISLNK(inode
->i_mode
))
4575 return !ext4_inode_is_fast_symlink(inode
);
4582 * We block out ext4_get_block() block instantiations across the entire
4583 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4584 * simultaneously on behalf of the same inode.
4586 * As we work through the truncate and commmit bits of it to the journal there
4587 * is one core, guiding principle: the file's tree must always be consistent on
4588 * disk. We must be able to restart the truncate after a crash.
4590 * The file's tree may be transiently inconsistent in memory (although it
4591 * probably isn't), but whenever we close off and commit a journal transaction,
4592 * the contents of (the filesystem + the journal) must be consistent and
4593 * restartable. It's pretty simple, really: bottom up, right to left (although
4594 * left-to-right works OK too).
4596 * Note that at recovery time, journal replay occurs *before* the restart of
4597 * truncate against the orphan inode list.
4599 * The committed inode has the new, desired i_size (which is the same as
4600 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4601 * that this inode's truncate did not complete and it will again call
4602 * ext4_truncate() to have another go. So there will be instantiated blocks
4603 * to the right of the truncation point in a crashed ext4 filesystem. But
4604 * that's fine - as long as they are linked from the inode, the post-crash
4605 * ext4_truncate() run will find them and release them.
4607 void ext4_truncate(struct inode
*inode
)
4610 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4611 __le32
*i_data
= ei
->i_data
;
4612 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4613 struct address_space
*mapping
= inode
->i_mapping
;
4614 ext4_lblk_t offsets
[4];
4619 ext4_lblk_t last_block
;
4620 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
4622 if (!ext4_can_truncate(inode
))
4625 ext4_clear_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
);
4627 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
4628 ext4_set_inode_state(inode
, EXT4_STATE_DA_ALLOC_CLOSE
);
4630 if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
4631 ext4_ext_truncate(inode
);
4635 handle
= start_transaction(inode
);
4637 return; /* AKPM: return what? */
4639 last_block
= (inode
->i_size
+ blocksize
-1)
4640 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
4642 if (inode
->i_size
& (blocksize
- 1))
4643 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
4646 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
4648 goto out_stop
; /* error */
4651 * OK. This truncate is going to happen. We add the inode to the
4652 * orphan list, so that if this truncate spans multiple transactions,
4653 * and we crash, we will resume the truncate when the filesystem
4654 * recovers. It also marks the inode dirty, to catch the new size.
4656 * Implication: the file must always be in a sane, consistent
4657 * truncatable state while each transaction commits.
4659 if (ext4_orphan_add(handle
, inode
))
4663 * From here we block out all ext4_get_block() callers who want to
4664 * modify the block allocation tree.
4666 down_write(&ei
->i_data_sem
);
4668 ext4_discard_preallocations(inode
);
4671 * The orphan list entry will now protect us from any crash which
4672 * occurs before the truncate completes, so it is now safe to propagate
4673 * the new, shorter inode size (held for now in i_size) into the
4674 * on-disk inode. We do this via i_disksize, which is the value which
4675 * ext4 *really* writes onto the disk inode.
4677 ei
->i_disksize
= inode
->i_size
;
4679 if (n
== 1) { /* direct blocks */
4680 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
4681 i_data
+ EXT4_NDIR_BLOCKS
);
4685 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
4686 /* Kill the top of shared branch (not detached) */
4688 if (partial
== chain
) {
4689 /* Shared branch grows from the inode */
4690 ext4_free_branches(handle
, inode
, NULL
,
4691 &nr
, &nr
+1, (chain
+n
-1) - partial
);
4694 * We mark the inode dirty prior to restart,
4695 * and prior to stop. No need for it here.
4698 /* Shared branch grows from an indirect block */
4699 BUFFER_TRACE(partial
->bh
, "get_write_access");
4700 ext4_free_branches(handle
, inode
, partial
->bh
,
4702 partial
->p
+1, (chain
+n
-1) - partial
);
4705 /* Clear the ends of indirect blocks on the shared branch */
4706 while (partial
> chain
) {
4707 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
4708 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
4709 (chain
+n
-1) - partial
);
4710 BUFFER_TRACE(partial
->bh
, "call brelse");
4711 brelse(partial
->bh
);
4715 /* Kill the remaining (whole) subtrees */
4716 switch (offsets
[0]) {
4718 nr
= i_data
[EXT4_IND_BLOCK
];
4720 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4721 i_data
[EXT4_IND_BLOCK
] = 0;
4723 case EXT4_IND_BLOCK
:
4724 nr
= i_data
[EXT4_DIND_BLOCK
];
4726 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4727 i_data
[EXT4_DIND_BLOCK
] = 0;
4729 case EXT4_DIND_BLOCK
:
4730 nr
= i_data
[EXT4_TIND_BLOCK
];
4732 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4733 i_data
[EXT4_TIND_BLOCK
] = 0;
4735 case EXT4_TIND_BLOCK
:
4739 up_write(&ei
->i_data_sem
);
4740 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4741 ext4_mark_inode_dirty(handle
, inode
);
4744 * In a multi-transaction truncate, we only make the final transaction
4748 ext4_handle_sync(handle
);
4751 * If this was a simple ftruncate(), and the file will remain alive
4752 * then we need to clear up the orphan record which we created above.
4753 * However, if this was a real unlink then we were called by
4754 * ext4_delete_inode(), and we allow that function to clean up the
4755 * orphan info for us.
4758 ext4_orphan_del(handle
, inode
);
4760 ext4_journal_stop(handle
);
4764 * ext4_get_inode_loc returns with an extra refcount against the inode's
4765 * underlying buffer_head on success. If 'in_mem' is true, we have all
4766 * data in memory that is needed to recreate the on-disk version of this
4769 static int __ext4_get_inode_loc(struct inode
*inode
,
4770 struct ext4_iloc
*iloc
, int in_mem
)
4772 struct ext4_group_desc
*gdp
;
4773 struct buffer_head
*bh
;
4774 struct super_block
*sb
= inode
->i_sb
;
4776 int inodes_per_block
, inode_offset
;
4779 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4782 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4783 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4788 * Figure out the offset within the block group inode table
4790 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4791 inode_offset
= ((inode
->i_ino
- 1) %
4792 EXT4_INODES_PER_GROUP(sb
));
4793 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4794 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4796 bh
= sb_getblk(sb
, block
);
4798 EXT4_ERROR_INODE_BLOCK(inode
, block
,
4799 "unable to read itable block");
4802 if (!buffer_uptodate(bh
)) {
4806 * If the buffer has the write error flag, we have failed
4807 * to write out another inode in the same block. In this
4808 * case, we don't have to read the block because we may
4809 * read the old inode data successfully.
4811 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4812 set_buffer_uptodate(bh
);
4814 if (buffer_uptodate(bh
)) {
4815 /* someone brought it uptodate while we waited */
4821 * If we have all information of the inode in memory and this
4822 * is the only valid inode in the block, we need not read the
4826 struct buffer_head
*bitmap_bh
;
4829 start
= inode_offset
& ~(inodes_per_block
- 1);
4831 /* Is the inode bitmap in cache? */
4832 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4837 * If the inode bitmap isn't in cache then the
4838 * optimisation may end up performing two reads instead
4839 * of one, so skip it.
4841 if (!buffer_uptodate(bitmap_bh
)) {
4845 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4846 if (i
== inode_offset
)
4848 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4852 if (i
== start
+ inodes_per_block
) {
4853 /* all other inodes are free, so skip I/O */
4854 memset(bh
->b_data
, 0, bh
->b_size
);
4855 set_buffer_uptodate(bh
);
4863 * If we need to do any I/O, try to pre-readahead extra
4864 * blocks from the inode table.
4866 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4867 ext4_fsblk_t b
, end
, table
;
4870 table
= ext4_inode_table(sb
, gdp
);
4871 /* s_inode_readahead_blks is always a power of 2 */
4872 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4875 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4876 num
= EXT4_INODES_PER_GROUP(sb
);
4877 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4878 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4879 num
-= ext4_itable_unused_count(sb
, gdp
);
4880 table
+= num
/ inodes_per_block
;
4884 sb_breadahead(sb
, b
++);
4888 * There are other valid inodes in the buffer, this inode
4889 * has in-inode xattrs, or we don't have this inode in memory.
4890 * Read the block from disk.
4893 bh
->b_end_io
= end_buffer_read_sync
;
4894 submit_bh(READ_META
, bh
);
4896 if (!buffer_uptodate(bh
)) {
4897 EXT4_ERROR_INODE_BLOCK(inode
, block
,
4898 "unable to read itable block");
4908 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4910 /* We have all inode data except xattrs in memory here. */
4911 return __ext4_get_inode_loc(inode
, iloc
,
4912 !ext4_test_inode_state(inode
, EXT4_STATE_XATTR
));
4915 void ext4_set_inode_flags(struct inode
*inode
)
4917 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4919 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4920 if (flags
& EXT4_SYNC_FL
)
4921 inode
->i_flags
|= S_SYNC
;
4922 if (flags
& EXT4_APPEND_FL
)
4923 inode
->i_flags
|= S_APPEND
;
4924 if (flags
& EXT4_IMMUTABLE_FL
)
4925 inode
->i_flags
|= S_IMMUTABLE
;
4926 if (flags
& EXT4_NOATIME_FL
)
4927 inode
->i_flags
|= S_NOATIME
;
4928 if (flags
& EXT4_DIRSYNC_FL
)
4929 inode
->i_flags
|= S_DIRSYNC
;
4932 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4933 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4935 unsigned int vfs_fl
;
4936 unsigned long old_fl
, new_fl
;
4939 vfs_fl
= ei
->vfs_inode
.i_flags
;
4940 old_fl
= ei
->i_flags
;
4941 new_fl
= old_fl
& ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4942 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|
4944 if (vfs_fl
& S_SYNC
)
4945 new_fl
|= EXT4_SYNC_FL
;
4946 if (vfs_fl
& S_APPEND
)
4947 new_fl
|= EXT4_APPEND_FL
;
4948 if (vfs_fl
& S_IMMUTABLE
)
4949 new_fl
|= EXT4_IMMUTABLE_FL
;
4950 if (vfs_fl
& S_NOATIME
)
4951 new_fl
|= EXT4_NOATIME_FL
;
4952 if (vfs_fl
& S_DIRSYNC
)
4953 new_fl
|= EXT4_DIRSYNC_FL
;
4954 } while (cmpxchg(&ei
->i_flags
, old_fl
, new_fl
) != old_fl
);
4957 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4958 struct ext4_inode_info
*ei
)
4961 struct inode
*inode
= &(ei
->vfs_inode
);
4962 struct super_block
*sb
= inode
->i_sb
;
4964 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4965 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4966 /* we are using combined 48 bit field */
4967 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4968 le32_to_cpu(raw_inode
->i_blocks_lo
);
4969 if (ext4_test_inode_flag(inode
, EXT4_INODE_HUGE_FILE
)) {
4970 /* i_blocks represent file system block size */
4971 return i_blocks
<< (inode
->i_blkbits
- 9);
4976 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4980 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4982 struct ext4_iloc iloc
;
4983 struct ext4_inode
*raw_inode
;
4984 struct ext4_inode_info
*ei
;
4985 struct inode
*inode
;
4986 journal_t
*journal
= EXT4_SB(sb
)->s_journal
;
4990 inode
= iget_locked(sb
, ino
);
4992 return ERR_PTR(-ENOMEM
);
4993 if (!(inode
->i_state
& I_NEW
))
4999 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
5002 raw_inode
= ext4_raw_inode(&iloc
);
5003 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
5004 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
5005 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
5006 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5007 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
5008 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
5010 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
5012 ei
->i_state_flags
= 0;
5013 ei
->i_dir_start_lookup
= 0;
5014 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
5015 /* We now have enough fields to check if the inode was active or not.
5016 * This is needed because nfsd might try to access dead inodes
5017 * the test is that same one that e2fsck uses
5018 * NeilBrown 1999oct15
5020 if (inode
->i_nlink
== 0) {
5021 if (inode
->i_mode
== 0 ||
5022 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
5023 /* this inode is deleted */
5027 /* The only unlinked inodes we let through here have
5028 * valid i_mode and are being read by the orphan
5029 * recovery code: that's fine, we're about to complete
5030 * the process of deleting those. */
5032 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
5033 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
5034 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
5035 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
5037 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
5038 inode
->i_size
= ext4_isize(raw_inode
);
5039 ei
->i_disksize
= inode
->i_size
;
5041 ei
->i_reserved_quota
= 0;
5043 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
5044 ei
->i_block_group
= iloc
.block_group
;
5045 ei
->i_last_alloc_group
= ~0;
5047 * NOTE! The in-memory inode i_data array is in little-endian order
5048 * even on big-endian machines: we do NOT byteswap the block numbers!
5050 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5051 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
5052 INIT_LIST_HEAD(&ei
->i_orphan
);
5055 * Set transaction id's of transactions that have to be committed
5056 * to finish f[data]sync. We set them to currently running transaction
5057 * as we cannot be sure that the inode or some of its metadata isn't
5058 * part of the transaction - the inode could have been reclaimed and
5059 * now it is reread from disk.
5062 transaction_t
*transaction
;
5065 spin_lock(&journal
->j_state_lock
);
5066 if (journal
->j_running_transaction
)
5067 transaction
= journal
->j_running_transaction
;
5069 transaction
= journal
->j_committing_transaction
;
5071 tid
= transaction
->t_tid
;
5073 tid
= journal
->j_commit_sequence
;
5074 spin_unlock(&journal
->j_state_lock
);
5075 ei
->i_sync_tid
= tid
;
5076 ei
->i_datasync_tid
= tid
;
5079 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
5080 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
5081 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
5082 EXT4_INODE_SIZE(inode
->i_sb
)) {
5086 if (ei
->i_extra_isize
== 0) {
5087 /* The extra space is currently unused. Use it. */
5088 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
5089 EXT4_GOOD_OLD_INODE_SIZE
;
5091 __le32
*magic
= (void *)raw_inode
+
5092 EXT4_GOOD_OLD_INODE_SIZE
+
5094 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
5095 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
5098 ei
->i_extra_isize
= 0;
5100 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
5101 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
5102 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
5103 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
5105 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
5106 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
5107 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5109 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
5113 if (ei
->i_file_acl
&&
5114 !ext4_data_block_valid(EXT4_SB(sb
), ei
->i_file_acl
, 1)) {
5115 EXT4_ERROR_INODE(inode
, "bad extended attribute block %llu",
5119 } else if (ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)) {
5120 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
5121 (S_ISLNK(inode
->i_mode
) &&
5122 !ext4_inode_is_fast_symlink(inode
)))
5123 /* Validate extent which is part of inode */
5124 ret
= ext4_ext_check_inode(inode
);
5125 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
5126 (S_ISLNK(inode
->i_mode
) &&
5127 !ext4_inode_is_fast_symlink(inode
))) {
5128 /* Validate block references which are part of inode */
5129 ret
= ext4_check_inode_blockref(inode
);
5134 if (S_ISREG(inode
->i_mode
)) {
5135 inode
->i_op
= &ext4_file_inode_operations
;
5136 inode
->i_fop
= &ext4_file_operations
;
5137 ext4_set_aops(inode
);
5138 } else if (S_ISDIR(inode
->i_mode
)) {
5139 inode
->i_op
= &ext4_dir_inode_operations
;
5140 inode
->i_fop
= &ext4_dir_operations
;
5141 } else if (S_ISLNK(inode
->i_mode
)) {
5142 if (ext4_inode_is_fast_symlink(inode
)) {
5143 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
5144 nd_terminate_link(ei
->i_data
, inode
->i_size
,
5145 sizeof(ei
->i_data
) - 1);
5147 inode
->i_op
= &ext4_symlink_inode_operations
;
5148 ext4_set_aops(inode
);
5150 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
5151 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
5152 inode
->i_op
= &ext4_special_inode_operations
;
5153 if (raw_inode
->i_block
[0])
5154 init_special_inode(inode
, inode
->i_mode
,
5155 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
5157 init_special_inode(inode
, inode
->i_mode
,
5158 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
5161 EXT4_ERROR_INODE(inode
, "bogus i_mode (%o)", inode
->i_mode
);
5165 ext4_set_inode_flags(inode
);
5166 unlock_new_inode(inode
);
5172 return ERR_PTR(ret
);
5175 static int ext4_inode_blocks_set(handle_t
*handle
,
5176 struct ext4_inode
*raw_inode
,
5177 struct ext4_inode_info
*ei
)
5179 struct inode
*inode
= &(ei
->vfs_inode
);
5180 u64 i_blocks
= inode
->i_blocks
;
5181 struct super_block
*sb
= inode
->i_sb
;
5183 if (i_blocks
<= ~0U) {
5185 * i_blocks can be represnted in a 32 bit variable
5186 * as multiple of 512 bytes
5188 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5189 raw_inode
->i_blocks_high
= 0;
5190 ext4_clear_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
5193 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
5196 if (i_blocks
<= 0xffffffffffffULL
) {
5198 * i_blocks can be represented in a 48 bit variable
5199 * as multiple of 512 bytes
5201 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5202 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
5203 ext4_clear_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
5205 ext4_set_inode_flag(inode
, EXT4_INODE_HUGE_FILE
);
5206 /* i_block is stored in file system block size */
5207 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
5208 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5209 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
5215 * Post the struct inode info into an on-disk inode location in the
5216 * buffer-cache. This gobbles the caller's reference to the
5217 * buffer_head in the inode location struct.
5219 * The caller must have write access to iloc->bh.
5221 static int ext4_do_update_inode(handle_t
*handle
,
5222 struct inode
*inode
,
5223 struct ext4_iloc
*iloc
)
5225 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
5226 struct ext4_inode_info
*ei
= EXT4_I(inode
);
5227 struct buffer_head
*bh
= iloc
->bh
;
5228 int err
= 0, rc
, block
;
5230 /* For fields not not tracking in the in-memory inode,
5231 * initialise them to zero for new inodes. */
5232 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
))
5233 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
5235 ext4_get_inode_flags(ei
);
5236 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
5237 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5238 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
5239 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
5241 * Fix up interoperability with old kernels. Otherwise, old inodes get
5242 * re-used with the upper 16 bits of the uid/gid intact
5245 raw_inode
->i_uid_high
=
5246 cpu_to_le16(high_16_bits(inode
->i_uid
));
5247 raw_inode
->i_gid_high
=
5248 cpu_to_le16(high_16_bits(inode
->i_gid
));
5250 raw_inode
->i_uid_high
= 0;
5251 raw_inode
->i_gid_high
= 0;
5254 raw_inode
->i_uid_low
=
5255 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
5256 raw_inode
->i_gid_low
=
5257 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
5258 raw_inode
->i_uid_high
= 0;
5259 raw_inode
->i_gid_high
= 0;
5261 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
5263 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
5264 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
5265 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
5266 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
5268 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
5270 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
5271 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
);
5272 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
5273 cpu_to_le32(EXT4_OS_HURD
))
5274 raw_inode
->i_file_acl_high
=
5275 cpu_to_le16(ei
->i_file_acl
>> 32);
5276 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
5277 ext4_isize_set(raw_inode
, ei
->i_disksize
);
5278 if (ei
->i_disksize
> 0x7fffffffULL
) {
5279 struct super_block
*sb
= inode
->i_sb
;
5280 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
5281 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
5282 EXT4_SB(sb
)->s_es
->s_rev_level
==
5283 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
5284 /* If this is the first large file
5285 * created, add a flag to the superblock.
5287 err
= ext4_journal_get_write_access(handle
,
5288 EXT4_SB(sb
)->s_sbh
);
5291 ext4_update_dynamic_rev(sb
);
5292 EXT4_SET_RO_COMPAT_FEATURE(sb
,
5293 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
5295 ext4_handle_sync(handle
);
5296 err
= ext4_handle_dirty_metadata(handle
, NULL
,
5297 EXT4_SB(sb
)->s_sbh
);
5300 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
5301 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
5302 if (old_valid_dev(inode
->i_rdev
)) {
5303 raw_inode
->i_block
[0] =
5304 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
5305 raw_inode
->i_block
[1] = 0;
5307 raw_inode
->i_block
[0] = 0;
5308 raw_inode
->i_block
[1] =
5309 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
5310 raw_inode
->i_block
[2] = 0;
5313 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5314 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
5316 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
5317 if (ei
->i_extra_isize
) {
5318 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5319 raw_inode
->i_version_hi
=
5320 cpu_to_le32(inode
->i_version
>> 32);
5321 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
5324 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
5325 rc
= ext4_handle_dirty_metadata(handle
, NULL
, bh
);
5328 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
5330 ext4_update_inode_fsync_trans(handle
, inode
, 0);
5333 ext4_std_error(inode
->i_sb
, err
);
5338 * ext4_write_inode()
5340 * We are called from a few places:
5342 * - Within generic_file_write() for O_SYNC files.
5343 * Here, there will be no transaction running. We wait for any running
5344 * trasnaction to commit.
5346 * - Within sys_sync(), kupdate and such.
5347 * We wait on commit, if tol to.
5349 * - Within prune_icache() (PF_MEMALLOC == true)
5350 * Here we simply return. We can't afford to block kswapd on the
5353 * In all cases it is actually safe for us to return without doing anything,
5354 * because the inode has been copied into a raw inode buffer in
5355 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5358 * Note that we are absolutely dependent upon all inode dirtiers doing the
5359 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5360 * which we are interested.
5362 * It would be a bug for them to not do this. The code:
5364 * mark_inode_dirty(inode)
5366 * inode->i_size = expr;
5368 * is in error because a kswapd-driven write_inode() could occur while
5369 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5370 * will no longer be on the superblock's dirty inode list.
5372 int ext4_write_inode(struct inode
*inode
, struct writeback_control
*wbc
)
5376 if (current
->flags
& PF_MEMALLOC
)
5379 if (EXT4_SB(inode
->i_sb
)->s_journal
) {
5380 if (ext4_journal_current_handle()) {
5381 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5386 if (wbc
->sync_mode
!= WB_SYNC_ALL
)
5389 err
= ext4_force_commit(inode
->i_sb
);
5391 struct ext4_iloc iloc
;
5393 err
= __ext4_get_inode_loc(inode
, &iloc
, 0);
5396 if (wbc
->sync_mode
== WB_SYNC_ALL
)
5397 sync_dirty_buffer(iloc
.bh
);
5398 if (buffer_req(iloc
.bh
) && !buffer_uptodate(iloc
.bh
)) {
5399 EXT4_ERROR_INODE_BLOCK(inode
, iloc
.bh
->b_blocknr
,
5400 "IO error syncing inode");
5411 * Called from notify_change.
5413 * We want to trap VFS attempts to truncate the file as soon as
5414 * possible. In particular, we want to make sure that when the VFS
5415 * shrinks i_size, we put the inode on the orphan list and modify
5416 * i_disksize immediately, so that during the subsequent flushing of
5417 * dirty pages and freeing of disk blocks, we can guarantee that any
5418 * commit will leave the blocks being flushed in an unused state on
5419 * disk. (On recovery, the inode will get truncated and the blocks will
5420 * be freed, so we have a strong guarantee that no future commit will
5421 * leave these blocks visible to the user.)
5423 * Another thing we have to assure is that if we are in ordered mode
5424 * and inode is still attached to the committing transaction, we must
5425 * we start writeout of all the dirty pages which are being truncated.
5426 * This way we are sure that all the data written in the previous
5427 * transaction are already on disk (truncate waits for pages under
5430 * Called with inode->i_mutex down.
5432 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
5434 struct inode
*inode
= dentry
->d_inode
;
5436 const unsigned int ia_valid
= attr
->ia_valid
;
5438 error
= inode_change_ok(inode
, attr
);
5442 if (is_quota_modification(inode
, attr
))
5443 dquot_initialize(inode
);
5444 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
5445 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
5448 /* (user+group)*(old+new) structure, inode write (sb,
5449 * inode block, ? - but truncate inode update has it) */
5450 handle
= ext4_journal_start(inode
, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode
->i_sb
)+
5451 EXT4_MAXQUOTAS_DEL_BLOCKS(inode
->i_sb
))+3);
5452 if (IS_ERR(handle
)) {
5453 error
= PTR_ERR(handle
);
5456 error
= dquot_transfer(inode
, attr
);
5458 ext4_journal_stop(handle
);
5461 /* Update corresponding info in inode so that everything is in
5462 * one transaction */
5463 if (attr
->ia_valid
& ATTR_UID
)
5464 inode
->i_uid
= attr
->ia_uid
;
5465 if (attr
->ia_valid
& ATTR_GID
)
5466 inode
->i_gid
= attr
->ia_gid
;
5467 error
= ext4_mark_inode_dirty(handle
, inode
);
5468 ext4_journal_stop(handle
);
5471 if (attr
->ia_valid
& ATTR_SIZE
) {
5472 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
))) {
5473 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5475 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
)
5480 if (S_ISREG(inode
->i_mode
) &&
5481 attr
->ia_valid
& ATTR_SIZE
&&
5482 (attr
->ia_size
< inode
->i_size
||
5483 (ext4_test_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
)))) {
5486 handle
= ext4_journal_start(inode
, 3);
5487 if (IS_ERR(handle
)) {
5488 error
= PTR_ERR(handle
);
5492 error
= ext4_orphan_add(handle
, inode
);
5493 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
5494 rc
= ext4_mark_inode_dirty(handle
, inode
);
5497 ext4_journal_stop(handle
);
5499 if (ext4_should_order_data(inode
)) {
5500 error
= ext4_begin_ordered_truncate(inode
,
5503 /* Do as much error cleanup as possible */
5504 handle
= ext4_journal_start(inode
, 3);
5505 if (IS_ERR(handle
)) {
5506 ext4_orphan_del(NULL
, inode
);
5509 ext4_orphan_del(handle
, inode
);
5510 ext4_journal_stop(handle
);
5514 /* ext4_truncate will clear the flag */
5515 if ((ext4_test_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
)))
5516 ext4_truncate(inode
);
5519 rc
= inode_setattr(inode
, attr
);
5521 /* If inode_setattr's call to ext4_truncate failed to get a
5522 * transaction handle at all, we need to clean up the in-core
5523 * orphan list manually. */
5525 ext4_orphan_del(NULL
, inode
);
5527 if (!rc
&& (ia_valid
& ATTR_MODE
))
5528 rc
= ext4_acl_chmod(inode
);
5531 ext4_std_error(inode
->i_sb
, error
);
5537 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
5540 struct inode
*inode
;
5541 unsigned long delalloc_blocks
;
5543 inode
= dentry
->d_inode
;
5544 generic_fillattr(inode
, stat
);
5547 * We can't update i_blocks if the block allocation is delayed
5548 * otherwise in the case of system crash before the real block
5549 * allocation is done, we will have i_blocks inconsistent with
5550 * on-disk file blocks.
5551 * We always keep i_blocks updated together with real
5552 * allocation. But to not confuse with user, stat
5553 * will return the blocks that include the delayed allocation
5554 * blocks for this file.
5556 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
5557 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
5558 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
5560 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
5564 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
5569 /* if nrblocks are contiguous */
5572 * With N contiguous data blocks, it need at most
5573 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5574 * 2 dindirect blocks
5577 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
5578 return indirects
+ 3;
5581 * if nrblocks are not contiguous, worse case, each block touch
5582 * a indirect block, and each indirect block touch a double indirect
5583 * block, plus a triple indirect block
5585 indirects
= nrblocks
* 2 + 1;
5589 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5591 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
5592 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
5593 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
5597 * Account for index blocks, block groups bitmaps and block group
5598 * descriptor blocks if modify datablocks and index blocks
5599 * worse case, the indexs blocks spread over different block groups
5601 * If datablocks are discontiguous, they are possible to spread over
5602 * different block groups too. If they are contiuguous, with flexbg,
5603 * they could still across block group boundary.
5605 * Also account for superblock, inode, quota and xattr blocks
5607 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5609 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
5615 * How many index blocks need to touch to modify nrblocks?
5616 * The "Chunk" flag indicating whether the nrblocks is
5617 * physically contiguous on disk
5619 * For Direct IO and fallocate, they calls get_block to allocate
5620 * one single extent at a time, so they could set the "Chunk" flag
5622 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
5627 * Now let's see how many group bitmaps and group descriptors need
5637 if (groups
> ngroups
)
5639 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
5640 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
5642 /* bitmaps and block group descriptor blocks */
5643 ret
+= groups
+ gdpblocks
;
5645 /* Blocks for super block, inode, quota and xattr blocks */
5646 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
5652 * Calulate the total number of credits to reserve to fit
5653 * the modification of a single pages into a single transaction,
5654 * which may include multiple chunks of block allocations.
5656 * This could be called via ext4_write_begin()
5658 * We need to consider the worse case, when
5659 * one new block per extent.
5661 int ext4_writepage_trans_blocks(struct inode
*inode
)
5663 int bpp
= ext4_journal_blocks_per_page(inode
);
5666 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
5668 /* Account for data blocks for journalled mode */
5669 if (ext4_should_journal_data(inode
))
5675 * Calculate the journal credits for a chunk of data modification.
5677 * This is called from DIO, fallocate or whoever calling
5678 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
5680 * journal buffers for data blocks are not included here, as DIO
5681 * and fallocate do no need to journal data buffers.
5683 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
5685 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
5689 * The caller must have previously called ext4_reserve_inode_write().
5690 * Give this, we know that the caller already has write access to iloc->bh.
5692 int ext4_mark_iloc_dirty(handle_t
*handle
,
5693 struct inode
*inode
, struct ext4_iloc
*iloc
)
5697 if (test_opt(inode
->i_sb
, I_VERSION
))
5698 inode_inc_iversion(inode
);
5700 /* the do_update_inode consumes one bh->b_count */
5703 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5704 err
= ext4_do_update_inode(handle
, inode
, iloc
);
5710 * On success, We end up with an outstanding reference count against
5711 * iloc->bh. This _must_ be cleaned up later.
5715 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
5716 struct ext4_iloc
*iloc
)
5720 err
= ext4_get_inode_loc(inode
, iloc
);
5722 BUFFER_TRACE(iloc
->bh
, "get_write_access");
5723 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
5729 ext4_std_error(inode
->i_sb
, err
);
5734 * Expand an inode by new_extra_isize bytes.
5735 * Returns 0 on success or negative error number on failure.
5737 static int ext4_expand_extra_isize(struct inode
*inode
,
5738 unsigned int new_extra_isize
,
5739 struct ext4_iloc iloc
,
5742 struct ext4_inode
*raw_inode
;
5743 struct ext4_xattr_ibody_header
*header
;
5745 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
5748 raw_inode
= ext4_raw_inode(&iloc
);
5750 header
= IHDR(inode
, raw_inode
);
5752 /* No extended attributes present */
5753 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
) ||
5754 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
5755 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5757 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5761 /* try to expand with EAs present */
5762 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5767 * What we do here is to mark the in-core inode as clean with respect to inode
5768 * dirtiness (it may still be data-dirty).
5769 * This means that the in-core inode may be reaped by prune_icache
5770 * without having to perform any I/O. This is a very good thing,
5771 * because *any* task may call prune_icache - even ones which
5772 * have a transaction open against a different journal.
5774 * Is this cheating? Not really. Sure, we haven't written the
5775 * inode out, but prune_icache isn't a user-visible syncing function.
5776 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5777 * we start and wait on commits.
5779 * Is this efficient/effective? Well, we're being nice to the system
5780 * by cleaning up our inodes proactively so they can be reaped
5781 * without I/O. But we are potentially leaving up to five seconds'
5782 * worth of inodes floating about which prune_icache wants us to
5783 * write out. One way to fix that would be to get prune_icache()
5784 * to do a write_super() to free up some memory. It has the desired
5787 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5789 struct ext4_iloc iloc
;
5790 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5791 static unsigned int mnt_count
;
5795 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5796 if (ext4_handle_valid(handle
) &&
5797 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5798 !ext4_test_inode_state(inode
, EXT4_STATE_NO_EXPAND
)) {
5800 * We need extra buffer credits since we may write into EA block
5801 * with this same handle. If journal_extend fails, then it will
5802 * only result in a minor loss of functionality for that inode.
5803 * If this is felt to be critical, then e2fsck should be run to
5804 * force a large enough s_min_extra_isize.
5806 if ((jbd2_journal_extend(handle
,
5807 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5808 ret
= ext4_expand_extra_isize(inode
,
5809 sbi
->s_want_extra_isize
,
5812 ext4_set_inode_state(inode
,
5813 EXT4_STATE_NO_EXPAND
);
5815 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5816 ext4_warning(inode
->i_sb
,
5817 "Unable to expand inode %lu. Delete"
5818 " some EAs or run e2fsck.",
5821 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5827 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5832 * ext4_dirty_inode() is called from __mark_inode_dirty()
5834 * We're really interested in the case where a file is being extended.
5835 * i_size has been changed by generic_commit_write() and we thus need
5836 * to include the updated inode in the current transaction.
5838 * Also, dquot_alloc_block() will always dirty the inode when blocks
5839 * are allocated to the file.
5841 * If the inode is marked synchronous, we don't honour that here - doing
5842 * so would cause a commit on atime updates, which we don't bother doing.
5843 * We handle synchronous inodes at the highest possible level.
5845 void ext4_dirty_inode(struct inode
*inode
)
5849 handle
= ext4_journal_start(inode
, 2);
5853 ext4_mark_inode_dirty(handle
, inode
);
5855 ext4_journal_stop(handle
);
5862 * Bind an inode's backing buffer_head into this transaction, to prevent
5863 * it from being flushed to disk early. Unlike
5864 * ext4_reserve_inode_write, this leaves behind no bh reference and
5865 * returns no iloc structure, so the caller needs to repeat the iloc
5866 * lookup to mark the inode dirty later.
5868 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5870 struct ext4_iloc iloc
;
5874 err
= ext4_get_inode_loc(inode
, &iloc
);
5876 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5877 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5879 err
= ext4_handle_dirty_metadata(handle
,
5885 ext4_std_error(inode
->i_sb
, err
);
5890 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5897 * We have to be very careful here: changing a data block's
5898 * journaling status dynamically is dangerous. If we write a
5899 * data block to the journal, change the status and then delete
5900 * that block, we risk forgetting to revoke the old log record
5901 * from the journal and so a subsequent replay can corrupt data.
5902 * So, first we make sure that the journal is empty and that
5903 * nobody is changing anything.
5906 journal
= EXT4_JOURNAL(inode
);
5909 if (is_journal_aborted(journal
))
5912 jbd2_journal_lock_updates(journal
);
5913 jbd2_journal_flush(journal
);
5916 * OK, there are no updates running now, and all cached data is
5917 * synced to disk. We are now in a completely consistent state
5918 * which doesn't have anything in the journal, and we know that
5919 * no filesystem updates are running, so it is safe to modify
5920 * the inode's in-core data-journaling state flag now.
5924 ext4_set_inode_flag(inode
, EXT4_INODE_JOURNAL_DATA
);
5926 ext4_clear_inode_flag(inode
, EXT4_INODE_JOURNAL_DATA
);
5927 ext4_set_aops(inode
);
5929 jbd2_journal_unlock_updates(journal
);
5931 /* Finally we can mark the inode as dirty. */
5933 handle
= ext4_journal_start(inode
, 1);
5935 return PTR_ERR(handle
);
5937 err
= ext4_mark_inode_dirty(handle
, inode
);
5938 ext4_handle_sync(handle
);
5939 ext4_journal_stop(handle
);
5940 ext4_std_error(inode
->i_sb
, err
);
5945 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5947 return !buffer_mapped(bh
);
5950 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5952 struct page
*page
= vmf
->page
;
5957 struct file
*file
= vma
->vm_file
;
5958 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5959 struct address_space
*mapping
= inode
->i_mapping
;
5962 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5963 * get i_mutex because we are already holding mmap_sem.
5965 down_read(&inode
->i_alloc_sem
);
5966 size
= i_size_read(inode
);
5967 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5968 || !PageUptodate(page
)) {
5969 /* page got truncated from under us? */
5973 if (PageMappedToDisk(page
))
5976 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5977 len
= size
& ~PAGE_CACHE_MASK
;
5979 len
= PAGE_CACHE_SIZE
;
5983 * return if we have all the buffers mapped. This avoid
5984 * the need to call write_begin/write_end which does a
5985 * journal_start/journal_stop which can block and take
5988 if (page_has_buffers(page
)) {
5989 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5990 ext4_bh_unmapped
)) {
5997 * OK, we need to fill the hole... Do write_begin write_end
5998 * to do block allocation/reservation.We are not holding
5999 * inode.i__mutex here. That allow * parallel write_begin,
6000 * write_end call. lock_page prevent this from happening
6001 * on the same page though
6003 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
6004 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
6007 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
6008 len
, len
, page
, fsdata
);
6014 ret
= VM_FAULT_SIGBUS
;
6015 up_read(&inode
->i_alloc_sem
);