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>
42 #include "ext4_jbd2.h"
45 #include "ext4_extents.h"
47 #include <trace/events/ext4.h>
49 #define MPAGE_DA_EXTENT_TAIL 0x01
51 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
54 return jbd2_journal_begin_ordered_truncate(
55 EXT4_SB(inode
->i_sb
)->s_journal
,
56 &EXT4_I(inode
)->jinode
,
60 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
63 * Test whether an inode is a fast symlink.
65 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
67 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
68 (inode
->i_sb
->s_blocksize
>> 9) : 0;
70 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
74 * Work out how many blocks we need to proceed with the next chunk of a
75 * truncate transaction.
77 static unsigned long blocks_for_truncate(struct inode
*inode
)
81 needed
= inode
->i_blocks
>> (inode
->i_sb
->s_blocksize_bits
- 9);
83 /* Give ourselves just enough room to cope with inodes in which
84 * i_blocks is corrupt: we've seen disk corruptions in the past
85 * which resulted in random data in an inode which looked enough
86 * like a regular file for ext4 to try to delete it. Things
87 * will go a bit crazy if that happens, but at least we should
88 * try not to panic the whole kernel. */
92 /* But we need to bound the transaction so we don't overflow the
94 if (needed
> EXT4_MAX_TRANS_DATA
)
95 needed
= EXT4_MAX_TRANS_DATA
;
97 return EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + needed
;
101 * Truncate transactions can be complex and absolutely huge. So we need to
102 * be able to restart the transaction at a conventient checkpoint to make
103 * sure we don't overflow the journal.
105 * start_transaction gets us a new handle for a truncate transaction,
106 * and extend_transaction tries to extend the existing one a bit. If
107 * extend fails, we need to propagate the failure up and restart the
108 * transaction in the top-level truncate loop. --sct
110 static handle_t
*start_transaction(struct inode
*inode
)
114 result
= ext4_journal_start(inode
, blocks_for_truncate(inode
));
118 ext4_std_error(inode
->i_sb
, PTR_ERR(result
));
123 * Try to extend this transaction for the purposes of truncation.
125 * Returns 0 if we managed to create more room. If we can't create more
126 * room, and the transaction must be restarted we return 1.
128 static int try_to_extend_transaction(handle_t
*handle
, struct inode
*inode
)
130 if (!ext4_handle_valid(handle
))
132 if (ext4_handle_has_enough_credits(handle
, EXT4_RESERVE_TRANS_BLOCKS
+1))
134 if (!ext4_journal_extend(handle
, blocks_for_truncate(inode
)))
140 * Restart the transaction associated with *handle. This does a commit,
141 * so before we call here everything must be consistently dirtied against
144 int ext4_truncate_restart_trans(handle_t
*handle
, struct inode
*inode
,
150 * Drop i_data_sem to avoid deadlock with ext4_get_blocks At this
151 * moment, get_block can be called only for blocks inside i_size since
152 * page cache has been already dropped and writes are blocked by
153 * i_mutex. So we can safely drop the i_data_sem here.
155 BUG_ON(EXT4_JOURNAL(inode
) == NULL
);
156 jbd_debug(2, "restarting handle %p\n", handle
);
157 up_write(&EXT4_I(inode
)->i_data_sem
);
158 ret
= ext4_journal_restart(handle
, blocks_for_truncate(inode
));
159 down_write(&EXT4_I(inode
)->i_data_sem
);
160 ext4_discard_preallocations(inode
);
166 * Called at the last iput() if i_nlink is zero.
168 void ext4_delete_inode(struct inode
*inode
)
173 if (ext4_should_order_data(inode
))
174 ext4_begin_ordered_truncate(inode
, 0);
175 truncate_inode_pages(&inode
->i_data
, 0);
177 if (is_bad_inode(inode
))
180 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
181 if (IS_ERR(handle
)) {
182 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
184 * If we're going to skip the normal cleanup, we still need to
185 * make sure that the in-core orphan linked list is properly
188 ext4_orphan_del(NULL
, inode
);
193 ext4_handle_sync(handle
);
195 err
= ext4_mark_inode_dirty(handle
, inode
);
197 ext4_warning(inode
->i_sb
, __func__
,
198 "couldn't mark inode dirty (err %d)", err
);
202 ext4_truncate(inode
);
205 * ext4_ext_truncate() doesn't reserve any slop when it
206 * restarts journal transactions; therefore there may not be
207 * enough credits left in the handle to remove the inode from
208 * the orphan list and set the dtime field.
210 if (!ext4_handle_has_enough_credits(handle
, 3)) {
211 err
= ext4_journal_extend(handle
, 3);
213 err
= ext4_journal_restart(handle
, 3);
215 ext4_warning(inode
->i_sb
, __func__
,
216 "couldn't extend journal (err %d)", err
);
218 ext4_journal_stop(handle
);
224 * Kill off the orphan record which ext4_truncate created.
225 * AKPM: I think this can be inside the above `if'.
226 * Note that ext4_orphan_del() has to be able to cope with the
227 * deletion of a non-existent orphan - this is because we don't
228 * know if ext4_truncate() actually created an orphan record.
229 * (Well, we could do this if we need to, but heck - it works)
231 ext4_orphan_del(handle
, inode
);
232 EXT4_I(inode
)->i_dtime
= get_seconds();
235 * One subtle ordering requirement: if anything has gone wrong
236 * (transaction abort, IO errors, whatever), then we can still
237 * do these next steps (the fs will already have been marked as
238 * having errors), but we can't free the inode if the mark_dirty
241 if (ext4_mark_inode_dirty(handle
, inode
))
242 /* If that failed, just do the required in-core inode clear. */
245 ext4_free_inode(handle
, inode
);
246 ext4_journal_stop(handle
);
249 clear_inode(inode
); /* We must guarantee clearing of inode... */
255 struct buffer_head
*bh
;
258 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
260 p
->key
= *(p
->p
= v
);
265 * ext4_block_to_path - parse the block number into array of offsets
266 * @inode: inode in question (we are only interested in its superblock)
267 * @i_block: block number to be parsed
268 * @offsets: array to store the offsets in
269 * @boundary: set this non-zero if the referred-to block is likely to be
270 * followed (on disk) by an indirect block.
272 * To store the locations of file's data ext4 uses a data structure common
273 * for UNIX filesystems - tree of pointers anchored in the inode, with
274 * data blocks at leaves and indirect blocks in intermediate nodes.
275 * This function translates the block number into path in that tree -
276 * return value is the path length and @offsets[n] is the offset of
277 * pointer to (n+1)th node in the nth one. If @block is out of range
278 * (negative or too large) warning is printed and zero returned.
280 * Note: function doesn't find node addresses, so no IO is needed. All
281 * we need to know is the capacity of indirect blocks (taken from the
286 * Portability note: the last comparison (check that we fit into triple
287 * indirect block) is spelled differently, because otherwise on an
288 * architecture with 32-bit longs and 8Kb pages we might get into trouble
289 * if our filesystem had 8Kb blocks. We might use long long, but that would
290 * kill us on x86. Oh, well, at least the sign propagation does not matter -
291 * i_block would have to be negative in the very beginning, so we would not
295 static int ext4_block_to_path(struct inode
*inode
,
297 ext4_lblk_t offsets
[4], int *boundary
)
299 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
300 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
301 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
302 indirect_blocks
= ptrs
,
303 double_blocks
= (1 << (ptrs_bits
* 2));
307 if (i_block
< direct_blocks
) {
308 offsets
[n
++] = i_block
;
309 final
= direct_blocks
;
310 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
311 offsets
[n
++] = EXT4_IND_BLOCK
;
312 offsets
[n
++] = i_block
;
314 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
315 offsets
[n
++] = EXT4_DIND_BLOCK
;
316 offsets
[n
++] = i_block
>> ptrs_bits
;
317 offsets
[n
++] = i_block
& (ptrs
- 1);
319 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
320 offsets
[n
++] = EXT4_TIND_BLOCK
;
321 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
322 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
323 offsets
[n
++] = i_block
& (ptrs
- 1);
326 ext4_warning(inode
->i_sb
, "ext4_block_to_path",
327 "block %lu > max in inode %lu",
328 i_block
+ direct_blocks
+
329 indirect_blocks
+ double_blocks
, inode
->i_ino
);
332 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
336 static int __ext4_check_blockref(const char *function
, struct inode
*inode
,
337 __le32
*p
, unsigned int max
)
342 while (bref
< p
+max
) {
343 blk
= le32_to_cpu(*bref
++);
345 unlikely(!ext4_data_block_valid(EXT4_SB(inode
->i_sb
),
347 ext4_error(inode
->i_sb
, function
,
348 "invalid block reference %u "
349 "in inode #%lu", blk
, inode
->i_ino
);
357 #define ext4_check_indirect_blockref(inode, bh) \
358 __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data, \
359 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
361 #define ext4_check_inode_blockref(inode) \
362 __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data, \
366 * ext4_get_branch - read the chain of indirect blocks leading to data
367 * @inode: inode in question
368 * @depth: depth of the chain (1 - direct pointer, etc.)
369 * @offsets: offsets of pointers in inode/indirect blocks
370 * @chain: place to store the result
371 * @err: here we store the error value
373 * Function fills the array of triples <key, p, bh> and returns %NULL
374 * if everything went OK or the pointer to the last filled triple
375 * (incomplete one) otherwise. Upon the return chain[i].key contains
376 * the number of (i+1)-th block in the chain (as it is stored in memory,
377 * i.e. little-endian 32-bit), chain[i].p contains the address of that
378 * number (it points into struct inode for i==0 and into the bh->b_data
379 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
380 * block for i>0 and NULL for i==0. In other words, it holds the block
381 * numbers of the chain, addresses they were taken from (and where we can
382 * verify that chain did not change) and buffer_heads hosting these
385 * Function stops when it stumbles upon zero pointer (absent block)
386 * (pointer to last triple returned, *@err == 0)
387 * or when it gets an IO error reading an indirect block
388 * (ditto, *@err == -EIO)
389 * or when it reads all @depth-1 indirect blocks successfully and finds
390 * the whole chain, all way to the data (returns %NULL, *err == 0).
392 * Need to be called with
393 * down_read(&EXT4_I(inode)->i_data_sem)
395 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
396 ext4_lblk_t
*offsets
,
397 Indirect chain
[4], int *err
)
399 struct super_block
*sb
= inode
->i_sb
;
401 struct buffer_head
*bh
;
404 /* i_data is not going away, no lock needed */
405 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
409 bh
= sb_getblk(sb
, le32_to_cpu(p
->key
));
413 if (!bh_uptodate_or_lock(bh
)) {
414 if (bh_submit_read(bh
) < 0) {
418 /* validate block references */
419 if (ext4_check_indirect_blockref(inode
, bh
)) {
425 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
439 * ext4_find_near - find a place for allocation with sufficient locality
441 * @ind: descriptor of indirect block.
443 * This function returns the preferred place for block allocation.
444 * It is used when heuristic for sequential allocation fails.
446 * + if there is a block to the left of our position - allocate near it.
447 * + if pointer will live in indirect block - allocate near that block.
448 * + if pointer will live in inode - allocate in the same
451 * In the latter case we colour the starting block by the callers PID to
452 * prevent it from clashing with concurrent allocations for a different inode
453 * in the same block group. The PID is used here so that functionally related
454 * files will be close-by on-disk.
456 * Caller must make sure that @ind is valid and will stay that way.
458 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
460 struct ext4_inode_info
*ei
= EXT4_I(inode
);
461 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
463 ext4_fsblk_t bg_start
;
464 ext4_fsblk_t last_block
;
465 ext4_grpblk_t colour
;
466 ext4_group_t block_group
;
467 int flex_size
= ext4_flex_bg_size(EXT4_SB(inode
->i_sb
));
469 /* Try to find previous block */
470 for (p
= ind
->p
- 1; p
>= start
; p
--) {
472 return le32_to_cpu(*p
);
475 /* No such thing, so let's try location of indirect block */
477 return ind
->bh
->b_blocknr
;
480 * It is going to be referred to from the inode itself? OK, just put it
481 * into the same cylinder group then.
483 block_group
= ei
->i_block_group
;
484 if (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) {
485 block_group
&= ~(flex_size
-1);
486 if (S_ISREG(inode
->i_mode
))
489 bg_start
= ext4_group_first_block_no(inode
->i_sb
, block_group
);
490 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
493 * If we are doing delayed allocation, we don't need take
494 * colour into account.
496 if (test_opt(inode
->i_sb
, DELALLOC
))
499 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
500 colour
= (current
->pid
% 16) *
501 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
503 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
504 return bg_start
+ colour
;
508 * ext4_find_goal - find a preferred place for allocation.
510 * @block: block we want
511 * @partial: pointer to the last triple within a chain
513 * Normally this function find the preferred place for block allocation,
515 * Because this is only used for non-extent files, we limit the block nr
518 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
524 * XXX need to get goal block from mballoc's data structures
527 goal
= ext4_find_near(inode
, partial
);
528 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
533 * ext4_blks_to_allocate: Look up the block map and count the number
534 * of direct blocks need to be allocated for the given branch.
536 * @branch: chain of indirect blocks
537 * @k: number of blocks need for indirect blocks
538 * @blks: number of data blocks to be mapped.
539 * @blocks_to_boundary: the offset in the indirect block
541 * return the total number of blocks to be allocate, including the
542 * direct and indirect blocks.
544 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned int blks
,
545 int blocks_to_boundary
)
547 unsigned int count
= 0;
550 * Simple case, [t,d]Indirect block(s) has not allocated yet
551 * then it's clear blocks on that path have not allocated
554 /* right now we don't handle cross boundary allocation */
555 if (blks
< blocks_to_boundary
+ 1)
558 count
+= blocks_to_boundary
+ 1;
563 while (count
< blks
&& count
<= blocks_to_boundary
&&
564 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
571 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
572 * @indirect_blks: the number of blocks need to allocate for indirect
575 * @new_blocks: on return it will store the new block numbers for
576 * the indirect blocks(if needed) and the first direct block,
577 * @blks: on return it will store the total number of allocated
580 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
581 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
582 int indirect_blks
, int blks
,
583 ext4_fsblk_t new_blocks
[4], int *err
)
585 struct ext4_allocation_request ar
;
587 unsigned long count
= 0, blk_allocated
= 0;
589 ext4_fsblk_t current_block
= 0;
593 * Here we try to allocate the requested multiple blocks at once,
594 * on a best-effort basis.
595 * To build a branch, we should allocate blocks for
596 * the indirect blocks(if not allocated yet), and at least
597 * the first direct block of this branch. That's the
598 * minimum number of blocks need to allocate(required)
600 /* first we try to allocate the indirect blocks */
601 target
= indirect_blks
;
604 /* allocating blocks for indirect blocks and direct blocks */
605 current_block
= ext4_new_meta_blocks(handle
, inode
,
610 BUG_ON(current_block
+ count
> EXT4_MAX_BLOCK_FILE_PHYS
);
613 /* allocate blocks for indirect blocks */
614 while (index
< indirect_blks
&& count
) {
615 new_blocks
[index
++] = current_block
++;
620 * save the new block number
621 * for the first direct block
623 new_blocks
[index
] = current_block
;
624 printk(KERN_INFO
"%s returned more blocks than "
625 "requested\n", __func__
);
631 target
= blks
- count
;
632 blk_allocated
= count
;
635 /* Now allocate data blocks */
636 memset(&ar
, 0, sizeof(ar
));
641 if (S_ISREG(inode
->i_mode
))
642 /* enable in-core preallocation only for regular files */
643 ar
.flags
= EXT4_MB_HINT_DATA
;
645 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
646 BUG_ON(current_block
+ ar
.len
> EXT4_MAX_BLOCK_FILE_PHYS
);
648 if (*err
&& (target
== blks
)) {
650 * if the allocation failed and we didn't allocate
656 if (target
== blks
) {
658 * save the new block number
659 * for the first direct block
661 new_blocks
[index
] = current_block
;
663 blk_allocated
+= ar
.len
;
666 /* total number of blocks allocated for direct blocks */
671 for (i
= 0; i
< index
; i
++)
672 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1, 0);
677 * ext4_alloc_branch - allocate and set up a chain of blocks.
679 * @indirect_blks: number of allocated indirect blocks
680 * @blks: number of allocated direct blocks
681 * @offsets: offsets (in the blocks) to store the pointers to next.
682 * @branch: place to store the chain in.
684 * This function allocates blocks, zeroes out all but the last one,
685 * links them into chain and (if we are synchronous) writes them to disk.
686 * In other words, it prepares a branch that can be spliced onto the
687 * inode. It stores the information about that chain in the branch[], in
688 * the same format as ext4_get_branch() would do. We are calling it after
689 * we had read the existing part of chain and partial points to the last
690 * triple of that (one with zero ->key). Upon the exit we have the same
691 * picture as after the successful ext4_get_block(), except that in one
692 * place chain is disconnected - *branch->p is still zero (we did not
693 * set the last link), but branch->key contains the number that should
694 * be placed into *branch->p to fill that gap.
696 * If allocation fails we free all blocks we've allocated (and forget
697 * their buffer_heads) and return the error value the from failed
698 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
699 * as described above and return 0.
701 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
702 ext4_lblk_t iblock
, int indirect_blks
,
703 int *blks
, ext4_fsblk_t goal
,
704 ext4_lblk_t
*offsets
, Indirect
*branch
)
706 int blocksize
= inode
->i_sb
->s_blocksize
;
709 struct buffer_head
*bh
;
711 ext4_fsblk_t new_blocks
[4];
712 ext4_fsblk_t current_block
;
714 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
715 *blks
, new_blocks
, &err
);
719 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
721 * metadata blocks and data blocks are allocated.
723 for (n
= 1; n
<= indirect_blks
; n
++) {
725 * Get buffer_head for parent block, zero it out
726 * and set the pointer to new one, then send
729 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
732 BUFFER_TRACE(bh
, "call get_create_access");
733 err
= ext4_journal_get_create_access(handle
, bh
);
735 /* Don't brelse(bh) here; it's done in
736 * ext4_journal_forget() below */
741 memset(bh
->b_data
, 0, blocksize
);
742 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
743 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
744 *branch
[n
].p
= branch
[n
].key
;
745 if (n
== indirect_blks
) {
746 current_block
= new_blocks
[n
];
748 * End of chain, update the last new metablock of
749 * the chain to point to the new allocated
750 * data blocks numbers
752 for (i
= 1; i
< num
; i
++)
753 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
755 BUFFER_TRACE(bh
, "marking uptodate");
756 set_buffer_uptodate(bh
);
759 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
760 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
767 /* Allocation failed, free what we already allocated */
768 ext4_free_blocks(handle
, inode
, 0, new_blocks
[0], 1, 0);
769 for (i
= 1; i
<= n
; i
++) {
771 * branch[i].bh is newly allocated, so there is no
772 * need to revoke the block, which is why we don't
773 * need to set EXT4_FREE_BLOCKS_METADATA.
775 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1,
776 EXT4_FREE_BLOCKS_FORGET
);
778 for (i
= n
+1; i
< indirect_blks
; i
++)
779 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], 1, 0);
781 ext4_free_blocks(handle
, inode
, 0, new_blocks
[i
], num
, 0);
787 * ext4_splice_branch - splice the allocated branch onto inode.
789 * @block: (logical) number of block we are adding
790 * @chain: chain of indirect blocks (with a missing link - see
792 * @where: location of missing link
793 * @num: number of indirect blocks we are adding
794 * @blks: number of direct blocks we are adding
796 * This function fills the missing link and does all housekeeping needed in
797 * inode (->i_blocks, etc.). In case of success we end up with the full
798 * chain to new block and return 0.
800 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
801 ext4_lblk_t block
, Indirect
*where
, int num
,
806 ext4_fsblk_t current_block
;
809 * If we're splicing into a [td]indirect block (as opposed to the
810 * inode) then we need to get write access to the [td]indirect block
814 BUFFER_TRACE(where
->bh
, "get_write_access");
815 err
= ext4_journal_get_write_access(handle
, where
->bh
);
821 *where
->p
= where
->key
;
824 * Update the host buffer_head or inode to point to more just allocated
825 * direct blocks blocks
827 if (num
== 0 && blks
> 1) {
828 current_block
= le32_to_cpu(where
->key
) + 1;
829 for (i
= 1; i
< blks
; i
++)
830 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
833 /* We are done with atomic stuff, now do the rest of housekeeping */
834 /* had we spliced it onto indirect block? */
837 * If we spliced it onto an indirect block, we haven't
838 * altered the inode. Note however that if it is being spliced
839 * onto an indirect block at the very end of the file (the
840 * file is growing) then we *will* alter the inode to reflect
841 * the new i_size. But that is not done here - it is done in
842 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
844 jbd_debug(5, "splicing indirect only\n");
845 BUFFER_TRACE(where
->bh
, "call ext4_handle_dirty_metadata");
846 err
= ext4_handle_dirty_metadata(handle
, inode
, where
->bh
);
851 * OK, we spliced it into the inode itself on a direct block.
853 ext4_mark_inode_dirty(handle
, inode
);
854 jbd_debug(5, "splicing direct\n");
859 for (i
= 1; i
<= num
; i
++) {
861 * branch[i].bh is newly allocated, so there is no
862 * need to revoke the block, which is why we don't
863 * need to set EXT4_FREE_BLOCKS_METADATA.
865 ext4_free_blocks(handle
, inode
, where
[i
].bh
, 0, 1,
866 EXT4_FREE_BLOCKS_FORGET
);
868 ext4_free_blocks(handle
, inode
, 0, le32_to_cpu(where
[num
].key
),
875 * The ext4_ind_get_blocks() function handles non-extents inodes
876 * (i.e., using the traditional indirect/double-indirect i_blocks
877 * scheme) for ext4_get_blocks().
879 * Allocation strategy is simple: if we have to allocate something, we will
880 * have to go the whole way to leaf. So let's do it before attaching anything
881 * to tree, set linkage between the newborn blocks, write them if sync is
882 * required, recheck the path, free and repeat if check fails, otherwise
883 * set the last missing link (that will protect us from any truncate-generated
884 * removals - all blocks on the path are immune now) and possibly force the
885 * write on the parent block.
886 * That has a nice additional property: no special recovery from the failed
887 * allocations is needed - we simply release blocks and do not touch anything
888 * reachable from inode.
890 * `handle' can be NULL if create == 0.
892 * return > 0, # of blocks mapped or allocated.
893 * return = 0, if plain lookup failed.
894 * return < 0, error case.
896 * The ext4_ind_get_blocks() function should be called with
897 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
898 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
899 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
902 static int ext4_ind_get_blocks(handle_t
*handle
, struct inode
*inode
,
903 ext4_lblk_t iblock
, unsigned int maxblocks
,
904 struct buffer_head
*bh_result
,
908 ext4_lblk_t offsets
[4];
913 int blocks_to_boundary
= 0;
916 ext4_fsblk_t first_block
= 0;
918 J_ASSERT(!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
));
919 J_ASSERT(handle
!= NULL
|| (flags
& EXT4_GET_BLOCKS_CREATE
) == 0);
920 depth
= ext4_block_to_path(inode
, iblock
, offsets
,
921 &blocks_to_boundary
);
926 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
928 /* Simplest case - block found, no allocation needed */
930 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
931 clear_buffer_new(bh_result
);
934 while (count
< maxblocks
&& count
<= blocks_to_boundary
) {
937 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
939 if (blk
== first_block
+ count
)
947 /* Next simple case - plain lookup or failed read of indirect block */
948 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0 || err
== -EIO
)
952 * Okay, we need to do block allocation.
954 goal
= ext4_find_goal(inode
, iblock
, partial
);
956 /* the number of blocks need to allocate for [d,t]indirect blocks */
957 indirect_blks
= (chain
+ depth
) - partial
- 1;
960 * Next look up the indirect map to count the totoal number of
961 * direct blocks to allocate for this branch.
963 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
964 maxblocks
, blocks_to_boundary
);
966 * Block out ext4_truncate while we alter the tree
968 err
= ext4_alloc_branch(handle
, inode
, iblock
, indirect_blks
,
970 offsets
+ (partial
- chain
), partial
);
973 * The ext4_splice_branch call will free and forget any buffers
974 * on the new chain if there is a failure, but that risks using
975 * up transaction credits, especially for bitmaps where the
976 * credits cannot be returned. Can we handle this somehow? We
977 * may need to return -EAGAIN upwards in the worst case. --sct
980 err
= ext4_splice_branch(handle
, inode
, iblock
,
981 partial
, indirect_blks
, count
);
985 set_buffer_new(bh_result
);
987 ext4_update_inode_fsync_trans(handle
, inode
, 1);
989 map_bh(bh_result
, inode
->i_sb
, le32_to_cpu(chain
[depth
-1].key
));
990 if (count
> blocks_to_boundary
)
991 set_buffer_boundary(bh_result
);
993 /* Clean up and exit */
994 partial
= chain
+ depth
- 1; /* the whole chain */
996 while (partial
> chain
) {
997 BUFFER_TRACE(partial
->bh
, "call brelse");
1001 BUFFER_TRACE(bh_result
, "returned");
1007 qsize_t
*ext4_get_reserved_space(struct inode
*inode
)
1009 return &EXT4_I(inode
)->i_reserved_quota
;
1013 * Calculate the number of metadata blocks need to reserve
1014 * to allocate @blocks for non extent file based file
1016 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
, int blocks
)
1018 int icap
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
1019 int ind_blks
, dind_blks
, tind_blks
;
1021 /* number of new indirect blocks needed */
1022 ind_blks
= (blocks
+ icap
- 1) / icap
;
1024 dind_blks
= (ind_blks
+ icap
- 1) / icap
;
1028 return ind_blks
+ dind_blks
+ tind_blks
;
1032 * Calculate the number of metadata blocks need to reserve
1033 * to allocate given number of blocks
1035 static int ext4_calc_metadata_amount(struct inode
*inode
, int blocks
)
1040 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
1041 return ext4_ext_calc_metadata_amount(inode
, blocks
);
1043 return ext4_indirect_calc_metadata_amount(inode
, blocks
);
1047 * Called with i_data_sem down, which is important since we can call
1048 * ext4_discard_preallocations() from here.
1050 static void ext4_da_update_reserve_space(struct inode
*inode
, int used
)
1052 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1053 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1056 spin_lock(&ei
->i_block_reservation_lock
);
1057 if (unlikely(used
> ei
->i_reserved_data_blocks
)) {
1058 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "%s: ino %lu, used %d "
1059 "with only %d reserved data blocks\n",
1060 __func__
, inode
->i_ino
, used
,
1061 ei
->i_reserved_data_blocks
);
1063 used
= ei
->i_reserved_data_blocks
;
1066 /* Update per-inode reservations */
1067 ei
->i_reserved_data_blocks
-= used
;
1068 used
+= ei
->i_allocated_meta_blocks
;
1069 ei
->i_reserved_meta_blocks
-= ei
->i_allocated_meta_blocks
;
1070 ei
->i_allocated_meta_blocks
= 0;
1071 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, used
);
1073 if (ei
->i_reserved_data_blocks
== 0) {
1075 * We can release all of the reserved metadata blocks
1076 * only when we have written all of the delayed
1077 * allocation blocks.
1079 mdb_free
= ei
->i_allocated_meta_blocks
;
1080 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1081 ei
->i_allocated_meta_blocks
= 0;
1083 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1085 /* Update quota subsystem */
1086 vfs_dq_claim_block(inode
, used
);
1088 vfs_dq_release_reservation_block(inode
, mdb_free
);
1091 * If we have done all the pending block allocations and if
1092 * there aren't any writers on the inode, we can discard the
1093 * inode's preallocations.
1095 if ((ei
->i_reserved_data_blocks
== 0) &&
1096 (atomic_read(&inode
->i_writecount
) == 0))
1097 ext4_discard_preallocations(inode
);
1100 static int check_block_validity(struct inode
*inode
, const char *msg
,
1101 sector_t logical
, sector_t phys
, int len
)
1103 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), phys
, len
)) {
1104 ext4_error(inode
->i_sb
, msg
,
1105 "inode #%lu logical block %llu mapped to %llu "
1106 "(size %d)", inode
->i_ino
,
1107 (unsigned long long) logical
,
1108 (unsigned long long) phys
, len
);
1115 * Return the number of contiguous dirty pages in a given inode
1116 * starting at page frame idx.
1118 static pgoff_t
ext4_num_dirty_pages(struct inode
*inode
, pgoff_t idx
,
1119 unsigned int max_pages
)
1121 struct address_space
*mapping
= inode
->i_mapping
;
1123 struct pagevec pvec
;
1125 int i
, nr_pages
, done
= 0;
1129 pagevec_init(&pvec
, 0);
1132 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1133 PAGECACHE_TAG_DIRTY
,
1134 (pgoff_t
)PAGEVEC_SIZE
);
1137 for (i
= 0; i
< nr_pages
; i
++) {
1138 struct page
*page
= pvec
.pages
[i
];
1139 struct buffer_head
*bh
, *head
;
1142 if (unlikely(page
->mapping
!= mapping
) ||
1144 PageWriteback(page
) ||
1145 page
->index
!= idx
) {
1150 if (page_has_buffers(page
)) {
1151 bh
= head
= page_buffers(page
);
1153 if (!buffer_delay(bh
) &&
1154 !buffer_unwritten(bh
))
1156 bh
= bh
->b_this_page
;
1157 } while (!done
&& (bh
!= head
));
1164 if (num
>= max_pages
)
1167 pagevec_release(&pvec
);
1173 * The ext4_get_blocks() function tries to look up the requested blocks,
1174 * and returns if the blocks are already mapped.
1176 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1177 * and store the allocated blocks in the result buffer head and mark it
1180 * If file type is extents based, it will call ext4_ext_get_blocks(),
1181 * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
1184 * On success, it returns the number of blocks being mapped or allocate.
1185 * if create==0 and the blocks are pre-allocated and uninitialized block,
1186 * the result buffer head is unmapped. If the create ==1, it will make sure
1187 * the buffer head is mapped.
1189 * It returns 0 if plain look up failed (blocks have not been allocated), in
1190 * that casem, buffer head is unmapped
1192 * It returns the error in case of allocation failure.
1194 int ext4_get_blocks(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1195 unsigned int max_blocks
, struct buffer_head
*bh
,
1200 clear_buffer_mapped(bh
);
1201 clear_buffer_unwritten(bh
);
1203 ext_debug("ext4_get_blocks(): inode %lu, flag %d, max_blocks %u,"
1204 "logical block %lu\n", inode
->i_ino
, flags
, max_blocks
,
1205 (unsigned long)block
);
1207 * Try to see if we can get the block without requesting a new
1208 * file system block.
1210 down_read((&EXT4_I(inode
)->i_data_sem
));
1211 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1212 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1215 retval
= ext4_ind_get_blocks(handle
, inode
, block
, max_blocks
,
1218 up_read((&EXT4_I(inode
)->i_data_sem
));
1220 if (retval
> 0 && buffer_mapped(bh
)) {
1221 int ret
= check_block_validity(inode
, "file system corruption",
1222 block
, bh
->b_blocknr
, retval
);
1227 /* If it is only a block(s) look up */
1228 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
1232 * Returns if the blocks have already allocated
1234 * Note that if blocks have been preallocated
1235 * ext4_ext_get_block() returns th create = 0
1236 * with buffer head unmapped.
1238 if (retval
> 0 && buffer_mapped(bh
))
1242 * When we call get_blocks without the create flag, the
1243 * BH_Unwritten flag could have gotten set if the blocks
1244 * requested were part of a uninitialized extent. We need to
1245 * clear this flag now that we are committed to convert all or
1246 * part of the uninitialized extent to be an initialized
1247 * extent. This is because we need to avoid the combination
1248 * of BH_Unwritten and BH_Mapped flags being simultaneously
1249 * set on the buffer_head.
1251 clear_buffer_unwritten(bh
);
1254 * New blocks allocate and/or writing to uninitialized extent
1255 * will possibly result in updating i_data, so we take
1256 * the write lock of i_data_sem, and call get_blocks()
1257 * with create == 1 flag.
1259 down_write((&EXT4_I(inode
)->i_data_sem
));
1262 * if the caller is from delayed allocation writeout path
1263 * we have already reserved fs blocks for allocation
1264 * let the underlying get_block() function know to
1265 * avoid double accounting
1267 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1268 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1270 * We need to check for EXT4 here because migrate
1271 * could have changed the inode type in between
1273 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1274 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1277 retval
= ext4_ind_get_blocks(handle
, inode
, block
,
1278 max_blocks
, bh
, flags
);
1280 if (retval
> 0 && buffer_new(bh
)) {
1282 * We allocated new blocks which will result in
1283 * i_data's format changing. Force the migrate
1284 * to fail by clearing migrate flags
1286 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_EXT_MIGRATE
;
1290 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1291 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1294 * Update reserved blocks/metadata blocks after successful
1295 * block allocation which had been deferred till now.
1297 if ((retval
> 0) && (flags
& EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
))
1298 ext4_da_update_reserve_space(inode
, retval
);
1300 up_write((&EXT4_I(inode
)->i_data_sem
));
1301 if (retval
> 0 && buffer_mapped(bh
)) {
1302 int ret
= check_block_validity(inode
, "file system "
1303 "corruption after allocation",
1304 block
, bh
->b_blocknr
, retval
);
1311 /* Maximum number of blocks we map for direct IO at once. */
1312 #define DIO_MAX_BLOCKS 4096
1314 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1315 struct buffer_head
*bh_result
, int create
)
1317 handle_t
*handle
= ext4_journal_current_handle();
1318 int ret
= 0, started
= 0;
1319 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1322 if (create
&& !handle
) {
1323 /* Direct IO write... */
1324 if (max_blocks
> DIO_MAX_BLOCKS
)
1325 max_blocks
= DIO_MAX_BLOCKS
;
1326 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1327 handle
= ext4_journal_start(inode
, dio_credits
);
1328 if (IS_ERR(handle
)) {
1329 ret
= PTR_ERR(handle
);
1335 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
1336 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1338 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1342 ext4_journal_stop(handle
);
1348 * `handle' can be NULL if create is zero
1350 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1351 ext4_lblk_t block
, int create
, int *errp
)
1353 struct buffer_head dummy
;
1357 J_ASSERT(handle
!= NULL
|| create
== 0);
1360 dummy
.b_blocknr
= -1000;
1361 buffer_trace_init(&dummy
.b_history
);
1363 flags
|= EXT4_GET_BLOCKS_CREATE
;
1364 err
= ext4_get_blocks(handle
, inode
, block
, 1, &dummy
, flags
);
1366 * ext4_get_blocks() returns number of blocks mapped. 0 in
1375 if (!err
&& buffer_mapped(&dummy
)) {
1376 struct buffer_head
*bh
;
1377 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1382 if (buffer_new(&dummy
)) {
1383 J_ASSERT(create
!= 0);
1384 J_ASSERT(handle
!= NULL
);
1387 * Now that we do not always journal data, we should
1388 * keep in mind whether this should always journal the
1389 * new buffer as metadata. For now, regular file
1390 * writes use ext4_get_block instead, so it's not a
1394 BUFFER_TRACE(bh
, "call get_create_access");
1395 fatal
= ext4_journal_get_create_access(handle
, bh
);
1396 if (!fatal
&& !buffer_uptodate(bh
)) {
1397 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1398 set_buffer_uptodate(bh
);
1401 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1402 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1406 BUFFER_TRACE(bh
, "not a new buffer");
1419 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1420 ext4_lblk_t block
, int create
, int *err
)
1422 struct buffer_head
*bh
;
1424 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1427 if (buffer_uptodate(bh
))
1429 ll_rw_block(READ_META
, 1, &bh
);
1431 if (buffer_uptodate(bh
))
1438 static int walk_page_buffers(handle_t
*handle
,
1439 struct buffer_head
*head
,
1443 int (*fn
)(handle_t
*handle
,
1444 struct buffer_head
*bh
))
1446 struct buffer_head
*bh
;
1447 unsigned block_start
, block_end
;
1448 unsigned blocksize
= head
->b_size
;
1450 struct buffer_head
*next
;
1452 for (bh
= head
, block_start
= 0;
1453 ret
== 0 && (bh
!= head
|| !block_start
);
1454 block_start
= block_end
, bh
= next
) {
1455 next
= bh
->b_this_page
;
1456 block_end
= block_start
+ blocksize
;
1457 if (block_end
<= from
|| block_start
>= to
) {
1458 if (partial
&& !buffer_uptodate(bh
))
1462 err
= (*fn
)(handle
, bh
);
1470 * To preserve ordering, it is essential that the hole instantiation and
1471 * the data write be encapsulated in a single transaction. We cannot
1472 * close off a transaction and start a new one between the ext4_get_block()
1473 * and the commit_write(). So doing the jbd2_journal_start at the start of
1474 * prepare_write() is the right place.
1476 * Also, this function can nest inside ext4_writepage() ->
1477 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1478 * has generated enough buffer credits to do the whole page. So we won't
1479 * block on the journal in that case, which is good, because the caller may
1482 * By accident, ext4 can be reentered when a transaction is open via
1483 * quota file writes. If we were to commit the transaction while thus
1484 * reentered, there can be a deadlock - we would be holding a quota
1485 * lock, and the commit would never complete if another thread had a
1486 * transaction open and was blocking on the quota lock - a ranking
1489 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1490 * will _not_ run commit under these circumstances because handle->h_ref
1491 * is elevated. We'll still have enough credits for the tiny quotafile
1494 static int do_journal_get_write_access(handle_t
*handle
,
1495 struct buffer_head
*bh
)
1497 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1499 return ext4_journal_get_write_access(handle
, bh
);
1503 * Truncate blocks that were not used by write. We have to truncate the
1504 * pagecache as well so that corresponding buffers get properly unmapped.
1506 static void ext4_truncate_failed_write(struct inode
*inode
)
1508 truncate_inode_pages(inode
->i_mapping
, inode
->i_size
);
1509 ext4_truncate(inode
);
1512 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1513 loff_t pos
, unsigned len
, unsigned flags
,
1514 struct page
**pagep
, void **fsdata
)
1516 struct inode
*inode
= mapping
->host
;
1517 int ret
, needed_blocks
;
1524 trace_ext4_write_begin(inode
, pos
, len
, flags
);
1526 * Reserve one block more for addition to orphan list in case
1527 * we allocate blocks but write fails for some reason
1529 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
1530 index
= pos
>> PAGE_CACHE_SHIFT
;
1531 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1535 handle
= ext4_journal_start(inode
, needed_blocks
);
1536 if (IS_ERR(handle
)) {
1537 ret
= PTR_ERR(handle
);
1541 /* We cannot recurse into the filesystem as the transaction is already
1543 flags
|= AOP_FLAG_NOFS
;
1545 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1547 ext4_journal_stop(handle
);
1553 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1556 if (!ret
&& ext4_should_journal_data(inode
)) {
1557 ret
= walk_page_buffers(handle
, page_buffers(page
),
1558 from
, to
, NULL
, do_journal_get_write_access
);
1563 page_cache_release(page
);
1565 * block_write_begin may have instantiated a few blocks
1566 * outside i_size. Trim these off again. Don't need
1567 * i_size_read because we hold i_mutex.
1569 * Add inode to orphan list in case we crash before
1572 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1573 ext4_orphan_add(handle
, inode
);
1575 ext4_journal_stop(handle
);
1576 if (pos
+ len
> inode
->i_size
) {
1577 ext4_truncate_failed_write(inode
);
1579 * If truncate failed early the inode might
1580 * still be on the orphan list; we need to
1581 * make sure the inode is removed from the
1582 * orphan list in that case.
1585 ext4_orphan_del(NULL
, inode
);
1589 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1595 /* For write_end() in data=journal mode */
1596 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1598 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1600 set_buffer_uptodate(bh
);
1601 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1604 static int ext4_generic_write_end(struct file
*file
,
1605 struct address_space
*mapping
,
1606 loff_t pos
, unsigned len
, unsigned copied
,
1607 struct page
*page
, void *fsdata
)
1609 int i_size_changed
= 0;
1610 struct inode
*inode
= mapping
->host
;
1611 handle_t
*handle
= ext4_journal_current_handle();
1613 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1616 * No need to use i_size_read() here, the i_size
1617 * cannot change under us because we hold i_mutex.
1619 * But it's important to update i_size while still holding page lock:
1620 * page writeout could otherwise come in and zero beyond i_size.
1622 if (pos
+ copied
> inode
->i_size
) {
1623 i_size_write(inode
, pos
+ copied
);
1627 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
1628 /* We need to mark inode dirty even if
1629 * new_i_size is less that inode->i_size
1630 * bu greater than i_disksize.(hint delalloc)
1632 ext4_update_i_disksize(inode
, (pos
+ copied
));
1636 page_cache_release(page
);
1639 * Don't mark the inode dirty under page lock. First, it unnecessarily
1640 * makes the holding time of page lock longer. Second, it forces lock
1641 * ordering of page lock and transaction start for journaling
1645 ext4_mark_inode_dirty(handle
, inode
);
1651 * We need to pick up the new inode size which generic_commit_write gave us
1652 * `file' can be NULL - eg, when called from page_symlink().
1654 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1655 * buffers are managed internally.
1657 static int ext4_ordered_write_end(struct file
*file
,
1658 struct address_space
*mapping
,
1659 loff_t pos
, unsigned len
, unsigned copied
,
1660 struct page
*page
, void *fsdata
)
1662 handle_t
*handle
= ext4_journal_current_handle();
1663 struct inode
*inode
= mapping
->host
;
1666 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
1667 ret
= ext4_jbd2_file_inode(handle
, inode
);
1670 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1673 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1674 /* if we have allocated more blocks and copied
1675 * less. We will have blocks allocated outside
1676 * inode->i_size. So truncate them
1678 ext4_orphan_add(handle
, inode
);
1682 ret2
= ext4_journal_stop(handle
);
1686 if (pos
+ len
> inode
->i_size
) {
1687 ext4_truncate_failed_write(inode
);
1689 * If truncate failed early the inode might still be
1690 * on the orphan list; we need to make sure the inode
1691 * is removed from the orphan list in that case.
1694 ext4_orphan_del(NULL
, inode
);
1698 return ret
? ret
: copied
;
1701 static int ext4_writeback_write_end(struct file
*file
,
1702 struct address_space
*mapping
,
1703 loff_t pos
, unsigned len
, unsigned copied
,
1704 struct page
*page
, void *fsdata
)
1706 handle_t
*handle
= ext4_journal_current_handle();
1707 struct inode
*inode
= mapping
->host
;
1710 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1711 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1714 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1715 /* if we have allocated more blocks and copied
1716 * less. We will have blocks allocated outside
1717 * inode->i_size. So truncate them
1719 ext4_orphan_add(handle
, inode
);
1724 ret2
= ext4_journal_stop(handle
);
1728 if (pos
+ len
> inode
->i_size
) {
1729 ext4_truncate_failed_write(inode
);
1731 * If truncate failed early the inode might still be
1732 * on the orphan list; we need to make sure the inode
1733 * is removed from the orphan list in that case.
1736 ext4_orphan_del(NULL
, inode
);
1739 return ret
? ret
: copied
;
1742 static int ext4_journalled_write_end(struct file
*file
,
1743 struct address_space
*mapping
,
1744 loff_t pos
, unsigned len
, unsigned copied
,
1745 struct page
*page
, void *fsdata
)
1747 handle_t
*handle
= ext4_journal_current_handle();
1748 struct inode
*inode
= mapping
->host
;
1754 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1755 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1759 if (!PageUptodate(page
))
1761 page_zero_new_buffers(page
, from
+copied
, to
);
1764 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1765 to
, &partial
, write_end_fn
);
1767 SetPageUptodate(page
);
1768 new_i_size
= pos
+ copied
;
1769 if (new_i_size
> inode
->i_size
)
1770 i_size_write(inode
, pos
+copied
);
1771 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1772 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1773 ext4_update_i_disksize(inode
, new_i_size
);
1774 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1780 page_cache_release(page
);
1781 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1782 /* if we have allocated more blocks and copied
1783 * less. We will have blocks allocated outside
1784 * inode->i_size. So truncate them
1786 ext4_orphan_add(handle
, inode
);
1788 ret2
= ext4_journal_stop(handle
);
1791 if (pos
+ len
> inode
->i_size
) {
1792 ext4_truncate_failed_write(inode
);
1794 * If truncate failed early the inode might still be
1795 * on the orphan list; we need to make sure the inode
1796 * is removed from the orphan list in that case.
1799 ext4_orphan_del(NULL
, inode
);
1802 return ret
? ret
: copied
;
1805 static int ext4_da_reserve_space(struct inode
*inode
, int nrblocks
)
1808 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1809 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1810 unsigned long md_needed
, md_reserved
, total
= 0;
1813 * recalculate the amount of metadata blocks to reserve
1814 * in order to allocate nrblocks
1815 * worse case is one extent per block
1818 spin_lock(&ei
->i_block_reservation_lock
);
1819 md_reserved
= ei
->i_reserved_meta_blocks
;
1820 md_needed
= ext4_calc_metadata_amount(inode
, nrblocks
);
1821 total
= md_needed
+ nrblocks
;
1822 spin_unlock(&ei
->i_block_reservation_lock
);
1825 * Make quota reservation here to prevent quota overflow
1826 * later. Real quota accounting is done at pages writeout
1829 if (vfs_dq_reserve_block(inode
, total
)) {
1831 * We tend to badly over-estimate the amount of
1832 * metadata blocks which are needed, so if we have
1833 * reserved any metadata blocks, try to force out the
1834 * inode and see if we have any better luck.
1836 if (md_reserved
&& retries
++ <= 3)
1841 if (ext4_claim_free_blocks(sbi
, total
)) {
1842 vfs_dq_release_reservation_block(inode
, total
);
1843 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1846 write_inode_now(inode
, (retries
== 3));
1852 spin_lock(&ei
->i_block_reservation_lock
);
1853 ei
->i_reserved_data_blocks
+= nrblocks
;
1854 ei
->i_reserved_meta_blocks
+= md_needed
;
1855 spin_unlock(&ei
->i_block_reservation_lock
);
1857 return 0; /* success */
1860 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1862 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1863 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1866 return; /* Nothing to release, exit */
1868 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1870 if (unlikely(to_free
> ei
->i_reserved_data_blocks
)) {
1872 * if there aren't enough reserved blocks, then the
1873 * counter is messed up somewhere. Since this
1874 * function is called from invalidate page, it's
1875 * harmless to return without any action.
1877 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "ext4_da_release_space: "
1878 "ino %lu, to_free %d with only %d reserved "
1879 "data blocks\n", inode
->i_ino
, to_free
,
1880 ei
->i_reserved_data_blocks
);
1882 to_free
= ei
->i_reserved_data_blocks
;
1884 ei
->i_reserved_data_blocks
-= to_free
;
1886 if (ei
->i_reserved_data_blocks
== 0) {
1888 * We can release all of the reserved metadata blocks
1889 * only when we have written all of the delayed
1890 * allocation blocks.
1892 to_free
+= ei
->i_allocated_meta_blocks
;
1893 ei
->i_allocated_meta_blocks
= 0;
1896 /* update fs dirty blocks counter */
1897 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, to_free
);
1899 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1901 vfs_dq_release_reservation_block(inode
, to_free
);
1904 static void ext4_da_page_release_reservation(struct page
*page
,
1905 unsigned long offset
)
1908 struct buffer_head
*head
, *bh
;
1909 unsigned int curr_off
= 0;
1911 head
= page_buffers(page
);
1914 unsigned int next_off
= curr_off
+ bh
->b_size
;
1916 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1918 clear_buffer_delay(bh
);
1920 curr_off
= next_off
;
1921 } while ((bh
= bh
->b_this_page
) != head
);
1922 ext4_da_release_space(page
->mapping
->host
, to_release
);
1926 * Delayed allocation stuff
1930 * mpage_da_submit_io - walks through extent of pages and try to write
1931 * them with writepage() call back
1933 * @mpd->inode: inode
1934 * @mpd->first_page: first page of the extent
1935 * @mpd->next_page: page after the last page of the extent
1937 * By the time mpage_da_submit_io() is called we expect all blocks
1938 * to be allocated. this may be wrong if allocation failed.
1940 * As pages are already locked by write_cache_pages(), we can't use it
1942 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1945 struct pagevec pvec
;
1946 unsigned long index
, end
;
1947 int ret
= 0, err
, nr_pages
, i
;
1948 struct inode
*inode
= mpd
->inode
;
1949 struct address_space
*mapping
= inode
->i_mapping
;
1951 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1953 * We need to start from the first_page to the next_page - 1
1954 * to make sure we also write the mapped dirty buffer_heads.
1955 * If we look at mpd->b_blocknr we would only be looking
1956 * at the currently mapped buffer_heads.
1958 index
= mpd
->first_page
;
1959 end
= mpd
->next_page
- 1;
1961 pagevec_init(&pvec
, 0);
1962 while (index
<= end
) {
1963 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1966 for (i
= 0; i
< nr_pages
; i
++) {
1967 struct page
*page
= pvec
.pages
[i
];
1969 index
= page
->index
;
1974 BUG_ON(!PageLocked(page
));
1975 BUG_ON(PageWriteback(page
));
1977 pages_skipped
= mpd
->wbc
->pages_skipped
;
1978 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
1979 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
1981 * have successfully written the page
1982 * without skipping the same
1984 mpd
->pages_written
++;
1986 * In error case, we have to continue because
1987 * remaining pages are still locked
1988 * XXX: unlock and re-dirty them?
1993 pagevec_release(&pvec
);
1999 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
2001 * @mpd->inode - inode to walk through
2002 * @exbh->b_blocknr - first block on a disk
2003 * @exbh->b_size - amount of space in bytes
2004 * @logical - first logical block to start assignment with
2006 * the function goes through all passed space and put actual disk
2007 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
2009 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
2010 struct buffer_head
*exbh
)
2012 struct inode
*inode
= mpd
->inode
;
2013 struct address_space
*mapping
= inode
->i_mapping
;
2014 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
2015 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
2016 struct buffer_head
*head
, *bh
;
2018 struct pagevec pvec
;
2021 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2022 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2023 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2025 pagevec_init(&pvec
, 0);
2027 while (index
<= end
) {
2028 /* XXX: optimize tail */
2029 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2032 for (i
= 0; i
< nr_pages
; i
++) {
2033 struct page
*page
= pvec
.pages
[i
];
2035 index
= page
->index
;
2040 BUG_ON(!PageLocked(page
));
2041 BUG_ON(PageWriteback(page
));
2042 BUG_ON(!page_has_buffers(page
));
2044 bh
= page_buffers(page
);
2047 /* skip blocks out of the range */
2049 if (cur_logical
>= logical
)
2052 } while ((bh
= bh
->b_this_page
) != head
);
2055 if (cur_logical
>= logical
+ blocks
)
2058 if (buffer_delay(bh
) ||
2059 buffer_unwritten(bh
)) {
2061 BUG_ON(bh
->b_bdev
!= inode
->i_sb
->s_bdev
);
2063 if (buffer_delay(bh
)) {
2064 clear_buffer_delay(bh
);
2065 bh
->b_blocknr
= pblock
;
2068 * unwritten already should have
2069 * blocknr assigned. Verify that
2071 clear_buffer_unwritten(bh
);
2072 BUG_ON(bh
->b_blocknr
!= pblock
);
2075 } else if (buffer_mapped(bh
))
2076 BUG_ON(bh
->b_blocknr
!= pblock
);
2080 } while ((bh
= bh
->b_this_page
) != head
);
2082 pagevec_release(&pvec
);
2088 * __unmap_underlying_blocks - just a helper function to unmap
2089 * set of blocks described by @bh
2091 static inline void __unmap_underlying_blocks(struct inode
*inode
,
2092 struct buffer_head
*bh
)
2094 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
2097 blocks
= bh
->b_size
>> inode
->i_blkbits
;
2098 for (i
= 0; i
< blocks
; i
++)
2099 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
2102 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
2103 sector_t logical
, long blk_cnt
)
2107 struct pagevec pvec
;
2108 struct inode
*inode
= mpd
->inode
;
2109 struct address_space
*mapping
= inode
->i_mapping
;
2111 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2112 end
= (logical
+ blk_cnt
- 1) >>
2113 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2114 while (index
<= end
) {
2115 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2118 for (i
= 0; i
< nr_pages
; i
++) {
2119 struct page
*page
= pvec
.pages
[i
];
2120 index
= page
->index
;
2125 BUG_ON(!PageLocked(page
));
2126 BUG_ON(PageWriteback(page
));
2127 block_invalidatepage(page
, 0);
2128 ClearPageUptodate(page
);
2135 static void ext4_print_free_blocks(struct inode
*inode
)
2137 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2138 printk(KERN_CRIT
"Total free blocks count %lld\n",
2139 ext4_count_free_blocks(inode
->i_sb
));
2140 printk(KERN_CRIT
"Free/Dirty block details\n");
2141 printk(KERN_CRIT
"free_blocks=%lld\n",
2142 (long long) percpu_counter_sum(&sbi
->s_freeblocks_counter
));
2143 printk(KERN_CRIT
"dirty_blocks=%lld\n",
2144 (long long) percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
2145 printk(KERN_CRIT
"Block reservation details\n");
2146 printk(KERN_CRIT
"i_reserved_data_blocks=%u\n",
2147 EXT4_I(inode
)->i_reserved_data_blocks
);
2148 printk(KERN_CRIT
"i_reserved_meta_blocks=%u\n",
2149 EXT4_I(inode
)->i_reserved_meta_blocks
);
2154 * mpage_da_map_blocks - go through given space
2156 * @mpd - bh describing space
2158 * The function skips space we know is already mapped to disk blocks.
2161 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
2163 int err
, blks
, get_blocks_flags
;
2164 struct buffer_head
new;
2165 sector_t next
= mpd
->b_blocknr
;
2166 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2167 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
2168 handle_t
*handle
= NULL
;
2171 * We consider only non-mapped and non-allocated blocks
2173 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2174 !(mpd
->b_state
& (1 << BH_Delay
)) &&
2175 !(mpd
->b_state
& (1 << BH_Unwritten
)))
2179 * If we didn't accumulate anything to write simply return
2184 handle
= ext4_journal_current_handle();
2188 * Call ext4_get_blocks() to allocate any delayed allocation
2189 * blocks, or to convert an uninitialized extent to be
2190 * initialized (in the case where we have written into
2191 * one or more preallocated blocks).
2193 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2194 * indicate that we are on the delayed allocation path. This
2195 * affects functions in many different parts of the allocation
2196 * call path. This flag exists primarily because we don't
2197 * want to change *many* call functions, so ext4_get_blocks()
2198 * will set the magic i_delalloc_reserved_flag once the
2199 * inode's allocation semaphore is taken.
2201 * If the blocks in questions were delalloc blocks, set
2202 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2203 * variables are updated after the blocks have been allocated.
2206 get_blocks_flags
= (EXT4_GET_BLOCKS_CREATE
|
2207 EXT4_GET_BLOCKS_DELALLOC_RESERVE
);
2208 if (mpd
->b_state
& (1 << BH_Delay
))
2209 get_blocks_flags
|= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
;
2210 blks
= ext4_get_blocks(handle
, mpd
->inode
, next
, max_blocks
,
2211 &new, get_blocks_flags
);
2215 * If get block returns with error we simply
2216 * return. Later writepage will redirty the page and
2217 * writepages will find the dirty page again
2222 if (err
== -ENOSPC
&&
2223 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
2229 * get block failure will cause us to loop in
2230 * writepages, because a_ops->writepage won't be able
2231 * to make progress. The page will be redirtied by
2232 * writepage and writepages will again try to write
2235 ext4_msg(mpd
->inode
->i_sb
, KERN_CRIT
,
2236 "delayed block allocation failed for inode %lu at "
2237 "logical offset %llu with max blocks %zd with "
2238 "error %d\n", mpd
->inode
->i_ino
,
2239 (unsigned long long) next
,
2240 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2241 printk(KERN_CRIT
"This should not happen!! "
2242 "Data will be lost\n");
2243 if (err
== -ENOSPC
) {
2244 ext4_print_free_blocks(mpd
->inode
);
2246 /* invalidate all the pages */
2247 ext4_da_block_invalidatepages(mpd
, next
,
2248 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2253 new.b_size
= (blks
<< mpd
->inode
->i_blkbits
);
2255 if (buffer_new(&new))
2256 __unmap_underlying_blocks(mpd
->inode
, &new);
2259 * If blocks are delayed marked, we need to
2260 * put actual blocknr and drop delayed bit
2262 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2263 (mpd
->b_state
& (1 << BH_Unwritten
)))
2264 mpage_put_bnr_to_bhs(mpd
, next
, &new);
2266 if (ext4_should_order_data(mpd
->inode
)) {
2267 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
2273 * Update on-disk size along with block allocation.
2275 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
2276 if (disksize
> i_size_read(mpd
->inode
))
2277 disksize
= i_size_read(mpd
->inode
);
2278 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
2279 ext4_update_i_disksize(mpd
->inode
, disksize
);
2280 return ext4_mark_inode_dirty(handle
, mpd
->inode
);
2286 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2287 (1 << BH_Delay) | (1 << BH_Unwritten))
2290 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2292 * @mpd->lbh - extent of blocks
2293 * @logical - logical number of the block in the file
2294 * @bh - bh of the block (used to access block's state)
2296 * the function is used to collect contig. blocks in same state
2298 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2299 sector_t logical
, size_t b_size
,
2300 unsigned long b_state
)
2303 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2305 /* check if thereserved journal credits might overflow */
2306 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
2307 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2309 * With non-extent format we are limited by the journal
2310 * credit available. Total credit needed to insert
2311 * nrblocks contiguous blocks is dependent on the
2312 * nrblocks. So limit nrblocks.
2315 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2316 EXT4_MAX_TRANS_DATA
) {
2318 * Adding the new buffer_head would make it cross the
2319 * allowed limit for which we have journal credit
2320 * reserved. So limit the new bh->b_size
2322 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2323 mpd
->inode
->i_blkbits
;
2324 /* we will do mpage_da_submit_io in the next loop */
2328 * First block in the extent
2330 if (mpd
->b_size
== 0) {
2331 mpd
->b_blocknr
= logical
;
2332 mpd
->b_size
= b_size
;
2333 mpd
->b_state
= b_state
& BH_FLAGS
;
2337 next
= mpd
->b_blocknr
+ nrblocks
;
2339 * Can we merge the block to our big extent?
2341 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2342 mpd
->b_size
+= b_size
;
2348 * We couldn't merge the block to our extent, so we
2349 * need to flush current extent and start new one
2351 if (mpage_da_map_blocks(mpd
) == 0)
2352 mpage_da_submit_io(mpd
);
2357 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
)
2359 return (buffer_delay(bh
) || buffer_unwritten(bh
)) && buffer_dirty(bh
);
2363 * __mpage_da_writepage - finds extent of pages and blocks
2365 * @page: page to consider
2366 * @wbc: not used, we just follow rules
2369 * The function finds extents of pages and scan them for all blocks.
2371 static int __mpage_da_writepage(struct page
*page
,
2372 struct writeback_control
*wbc
, void *data
)
2374 struct mpage_da_data
*mpd
= data
;
2375 struct inode
*inode
= mpd
->inode
;
2376 struct buffer_head
*bh
, *head
;
2381 * Rest of the page in the page_vec
2382 * redirty then and skip then. We will
2383 * try to write them again after
2384 * starting a new transaction
2386 redirty_page_for_writepage(wbc
, page
);
2388 return MPAGE_DA_EXTENT_TAIL
;
2391 * Can we merge this page to current extent?
2393 if (mpd
->next_page
!= page
->index
) {
2395 * Nope, we can't. So, we map non-allocated blocks
2396 * and start IO on them using writepage()
2398 if (mpd
->next_page
!= mpd
->first_page
) {
2399 if (mpage_da_map_blocks(mpd
) == 0)
2400 mpage_da_submit_io(mpd
);
2402 * skip rest of the page in the page_vec
2405 redirty_page_for_writepage(wbc
, page
);
2407 return MPAGE_DA_EXTENT_TAIL
;
2411 * Start next extent of pages ...
2413 mpd
->first_page
= page
->index
;
2423 mpd
->next_page
= page
->index
+ 1;
2424 logical
= (sector_t
) page
->index
<<
2425 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2427 if (!page_has_buffers(page
)) {
2428 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2429 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2431 return MPAGE_DA_EXTENT_TAIL
;
2434 * Page with regular buffer heads, just add all dirty ones
2436 head
= page_buffers(page
);
2439 BUG_ON(buffer_locked(bh
));
2441 * We need to try to allocate
2442 * unmapped blocks in the same page.
2443 * Otherwise we won't make progress
2444 * with the page in ext4_writepage
2446 if (ext4_bh_delay_or_unwritten(NULL
, bh
)) {
2447 mpage_add_bh_to_extent(mpd
, logical
,
2451 return MPAGE_DA_EXTENT_TAIL
;
2452 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2454 * mapped dirty buffer. We need to update
2455 * the b_state because we look at
2456 * b_state in mpage_da_map_blocks. We don't
2457 * update b_size because if we find an
2458 * unmapped buffer_head later we need to
2459 * use the b_state flag of that buffer_head.
2461 if (mpd
->b_size
== 0)
2462 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2465 } while ((bh
= bh
->b_this_page
) != head
);
2472 * This is a special get_blocks_t callback which is used by
2473 * ext4_da_write_begin(). It will either return mapped block or
2474 * reserve space for a single block.
2476 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2477 * We also have b_blocknr = -1 and b_bdev initialized properly
2479 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2480 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2481 * initialized properly.
2483 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2484 struct buffer_head
*bh_result
, int create
)
2487 sector_t invalid_block
= ~((sector_t
) 0xffff);
2489 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
2492 BUG_ON(create
== 0);
2493 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2496 * first, we need to know whether the block is allocated already
2497 * preallocated blocks are unmapped but should treated
2498 * the same as allocated blocks.
2500 ret
= ext4_get_blocks(NULL
, inode
, iblock
, 1, bh_result
, 0);
2501 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2502 /* the block isn't (pre)allocated yet, let's reserve space */
2504 * XXX: __block_prepare_write() unmaps passed block,
2507 ret
= ext4_da_reserve_space(inode
, 1);
2509 /* not enough space to reserve */
2512 map_bh(bh_result
, inode
->i_sb
, invalid_block
);
2513 set_buffer_new(bh_result
);
2514 set_buffer_delay(bh_result
);
2515 } else if (ret
> 0) {
2516 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2517 if (buffer_unwritten(bh_result
)) {
2518 /* A delayed write to unwritten bh should
2519 * be marked new and mapped. Mapped ensures
2520 * that we don't do get_block multiple times
2521 * when we write to the same offset and new
2522 * ensures that we do proper zero out for
2525 set_buffer_new(bh_result
);
2526 set_buffer_mapped(bh_result
);
2535 * This function is used as a standard get_block_t calback function
2536 * when there is no desire to allocate any blocks. It is used as a
2537 * callback function for block_prepare_write(), nobh_writepage(), and
2538 * block_write_full_page(). These functions should only try to map a
2539 * single block at a time.
2541 * Since this function doesn't do block allocations even if the caller
2542 * requests it by passing in create=1, it is critically important that
2543 * any caller checks to make sure that any buffer heads are returned
2544 * by this function are either all already mapped or marked for
2545 * delayed allocation before calling nobh_writepage() or
2546 * block_write_full_page(). Otherwise, b_blocknr could be left
2547 * unitialized, and the page write functions will be taken by
2550 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
2551 struct buffer_head
*bh_result
, int create
)
2554 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2556 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2559 * we don't want to do block allocation in writepage
2560 * so call get_block_wrap with create = 0
2562 ret
= ext4_get_blocks(NULL
, inode
, iblock
, max_blocks
, bh_result
, 0);
2564 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2570 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2576 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2582 static int __ext4_journalled_writepage(struct page
*page
,
2585 struct address_space
*mapping
= page
->mapping
;
2586 struct inode
*inode
= mapping
->host
;
2587 struct buffer_head
*page_bufs
;
2588 handle_t
*handle
= NULL
;
2592 page_bufs
= page_buffers(page
);
2594 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bget_one
);
2595 /* As soon as we unlock the page, it can go away, but we have
2596 * references to buffers so we are safe */
2599 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
2600 if (IS_ERR(handle
)) {
2601 ret
= PTR_ERR(handle
);
2605 ret
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2606 do_journal_get_write_access
);
2608 err
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2612 err
= ext4_journal_stop(handle
);
2616 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bput_one
);
2617 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
2623 * Note that we don't need to start a transaction unless we're journaling data
2624 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2625 * need to file the inode to the transaction's list in ordered mode because if
2626 * we are writing back data added by write(), the inode is already there and if
2627 * we are writing back data modified via mmap(), noone guarantees in which
2628 * transaction the data will hit the disk. In case we are journaling data, we
2629 * cannot start transaction directly because transaction start ranks above page
2630 * lock so we have to do some magic.
2632 * This function can get called via...
2633 * - ext4_da_writepages after taking page lock (have journal handle)
2634 * - journal_submit_inode_data_buffers (no journal handle)
2635 * - shrink_page_list via pdflush (no journal handle)
2636 * - grab_page_cache when doing write_begin (have journal handle)
2638 * We don't do any block allocation in this function. If we have page with
2639 * multiple blocks we need to write those buffer_heads that are mapped. This
2640 * is important for mmaped based write. So if we do with blocksize 1K
2641 * truncate(f, 1024);
2642 * a = mmap(f, 0, 4096);
2644 * truncate(f, 4096);
2645 * we have in the page first buffer_head mapped via page_mkwrite call back
2646 * but other bufer_heads would be unmapped but dirty(dirty done via the
2647 * do_wp_page). So writepage should write the first block. If we modify
2648 * the mmap area beyond 1024 we will again get a page_fault and the
2649 * page_mkwrite callback will do the block allocation and mark the
2650 * buffer_heads mapped.
2652 * We redirty the page if we have any buffer_heads that is either delay or
2653 * unwritten in the page.
2655 * We can get recursively called as show below.
2657 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2660 * But since we don't do any block allocation we should not deadlock.
2661 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2663 static int ext4_writepage(struct page
*page
,
2664 struct writeback_control
*wbc
)
2669 struct buffer_head
*page_bufs
;
2670 struct inode
*inode
= page
->mapping
->host
;
2672 trace_ext4_writepage(inode
, page
);
2673 size
= i_size_read(inode
);
2674 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2675 len
= size
& ~PAGE_CACHE_MASK
;
2677 len
= PAGE_CACHE_SIZE
;
2679 if (page_has_buffers(page
)) {
2680 page_bufs
= page_buffers(page
);
2681 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2682 ext4_bh_delay_or_unwritten
)) {
2684 * We don't want to do block allocation
2685 * So redirty the page and return
2686 * We may reach here when we do a journal commit
2687 * via journal_submit_inode_data_buffers.
2688 * If we don't have mapping block we just ignore
2689 * them. We can also reach here via shrink_page_list
2691 redirty_page_for_writepage(wbc
, page
);
2697 * The test for page_has_buffers() is subtle:
2698 * We know the page is dirty but it lost buffers. That means
2699 * that at some moment in time after write_begin()/write_end()
2700 * has been called all buffers have been clean and thus they
2701 * must have been written at least once. So they are all
2702 * mapped and we can happily proceed with mapping them
2703 * and writing the page.
2705 * Try to initialize the buffer_heads and check whether
2706 * all are mapped and non delay. We don't want to
2707 * do block allocation here.
2709 ret
= block_prepare_write(page
, 0, len
,
2710 noalloc_get_block_write
);
2712 page_bufs
= page_buffers(page
);
2713 /* check whether all are mapped and non delay */
2714 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2715 ext4_bh_delay_or_unwritten
)) {
2716 redirty_page_for_writepage(wbc
, page
);
2722 * We can't do block allocation here
2723 * so just redity the page and unlock
2726 redirty_page_for_writepage(wbc
, page
);
2730 /* now mark the buffer_heads as dirty and uptodate */
2731 block_commit_write(page
, 0, len
);
2734 if (PageChecked(page
) && ext4_should_journal_data(inode
)) {
2736 * It's mmapped pagecache. Add buffers and journal it. There
2737 * doesn't seem much point in redirtying the page here.
2739 ClearPageChecked(page
);
2740 return __ext4_journalled_writepage(page
, len
);
2743 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2744 ret
= nobh_writepage(page
, noalloc_get_block_write
, wbc
);
2746 ret
= block_write_full_page(page
, noalloc_get_block_write
,
2753 * This is called via ext4_da_writepages() to
2754 * calulate the total number of credits to reserve to fit
2755 * a single extent allocation into a single transaction,
2756 * ext4_da_writpeages() will loop calling this before
2757 * the block allocation.
2760 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2762 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2765 * With non-extent format the journal credit needed to
2766 * insert nrblocks contiguous block is dependent on
2767 * number of contiguous block. So we will limit
2768 * number of contiguous block to a sane value
2770 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) &&
2771 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2772 max_blocks
= EXT4_MAX_TRANS_DATA
;
2774 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2777 static int ext4_da_writepages(struct address_space
*mapping
,
2778 struct writeback_control
*wbc
)
2781 int range_whole
= 0;
2782 handle_t
*handle
= NULL
;
2783 struct mpage_da_data mpd
;
2784 struct inode
*inode
= mapping
->host
;
2785 int no_nrwrite_index_update
;
2786 int pages_written
= 0;
2788 unsigned int max_pages
;
2789 int range_cyclic
, cycled
= 1, io_done
= 0;
2790 int needed_blocks
, ret
= 0;
2791 long desired_nr_to_write
, nr_to_writebump
= 0;
2792 loff_t range_start
= wbc
->range_start
;
2793 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2795 trace_ext4_da_writepages(inode
, wbc
);
2798 * No pages to write? This is mainly a kludge to avoid starting
2799 * a transaction for special inodes like journal inode on last iput()
2800 * because that could violate lock ordering on umount
2802 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2806 * If the filesystem has aborted, it is read-only, so return
2807 * right away instead of dumping stack traces later on that
2808 * will obscure the real source of the problem. We test
2809 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2810 * the latter could be true if the filesystem is mounted
2811 * read-only, and in that case, ext4_da_writepages should
2812 * *never* be called, so if that ever happens, we would want
2815 if (unlikely(sbi
->s_mount_flags
& EXT4_MF_FS_ABORTED
))
2818 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2821 range_cyclic
= wbc
->range_cyclic
;
2822 if (wbc
->range_cyclic
) {
2823 index
= mapping
->writeback_index
;
2826 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2827 wbc
->range_end
= LLONG_MAX
;
2828 wbc
->range_cyclic
= 0;
2830 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2833 * This works around two forms of stupidity. The first is in
2834 * the writeback code, which caps the maximum number of pages
2835 * written to be 1024 pages. This is wrong on multiple
2836 * levels; different architectues have a different page size,
2837 * which changes the maximum amount of data which gets
2838 * written. Secondly, 4 megabytes is way too small. XFS
2839 * forces this value to be 16 megabytes by multiplying
2840 * nr_to_write parameter by four, and then relies on its
2841 * allocator to allocate larger extents to make them
2842 * contiguous. Unfortunately this brings us to the second
2843 * stupidity, which is that ext4's mballoc code only allocates
2844 * at most 2048 blocks. So we force contiguous writes up to
2845 * the number of dirty blocks in the inode, or
2846 * sbi->max_writeback_mb_bump whichever is smaller.
2848 max_pages
= sbi
->s_max_writeback_mb_bump
<< (20 - PAGE_CACHE_SHIFT
);
2849 if (!range_cyclic
&& range_whole
)
2850 desired_nr_to_write
= wbc
->nr_to_write
* 8;
2852 desired_nr_to_write
= ext4_num_dirty_pages(inode
, index
,
2854 if (desired_nr_to_write
> max_pages
)
2855 desired_nr_to_write
= max_pages
;
2857 if (wbc
->nr_to_write
< desired_nr_to_write
) {
2858 nr_to_writebump
= desired_nr_to_write
- wbc
->nr_to_write
;
2859 wbc
->nr_to_write
= desired_nr_to_write
;
2863 mpd
.inode
= mapping
->host
;
2866 * we don't want write_cache_pages to update
2867 * nr_to_write and writeback_index
2869 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2870 wbc
->no_nrwrite_index_update
= 1;
2871 pages_skipped
= wbc
->pages_skipped
;
2874 while (!ret
&& wbc
->nr_to_write
> 0) {
2877 * we insert one extent at a time. So we need
2878 * credit needed for single extent allocation.
2879 * journalled mode is currently not supported
2882 BUG_ON(ext4_should_journal_data(inode
));
2883 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2885 /* start a new transaction*/
2886 handle
= ext4_journal_start(inode
, needed_blocks
);
2887 if (IS_ERR(handle
)) {
2888 ret
= PTR_ERR(handle
);
2889 ext4_msg(inode
->i_sb
, KERN_CRIT
, "%s: jbd2_start: "
2890 "%ld pages, ino %lu; err %d\n", __func__
,
2891 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2892 goto out_writepages
;
2896 * Now call __mpage_da_writepage to find the next
2897 * contiguous region of logical blocks that need
2898 * blocks to be allocated by ext4. We don't actually
2899 * submit the blocks for I/O here, even though
2900 * write_cache_pages thinks it will, and will set the
2901 * pages as clean for write before calling
2902 * __mpage_da_writepage().
2910 mpd
.pages_written
= 0;
2912 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
,
2915 * If we have a contiguous extent of pages and we
2916 * haven't done the I/O yet, map the blocks and submit
2919 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
2920 if (mpage_da_map_blocks(&mpd
) == 0)
2921 mpage_da_submit_io(&mpd
);
2923 ret
= MPAGE_DA_EXTENT_TAIL
;
2925 trace_ext4_da_write_pages(inode
, &mpd
);
2926 wbc
->nr_to_write
-= mpd
.pages_written
;
2928 ext4_journal_stop(handle
);
2930 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2931 /* commit the transaction which would
2932 * free blocks released in the transaction
2935 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2936 wbc
->pages_skipped
= pages_skipped
;
2938 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2940 * got one extent now try with
2943 pages_written
+= mpd
.pages_written
;
2944 wbc
->pages_skipped
= pages_skipped
;
2947 } else if (wbc
->nr_to_write
)
2949 * There is no more writeout needed
2950 * or we requested for a noblocking writeout
2951 * and we found the device congested
2955 if (!io_done
&& !cycled
) {
2958 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2959 wbc
->range_end
= mapping
->writeback_index
- 1;
2962 if (pages_skipped
!= wbc
->pages_skipped
)
2963 ext4_msg(inode
->i_sb
, KERN_CRIT
,
2964 "This should not happen leaving %s "
2965 "with nr_to_write = %ld ret = %d\n",
2966 __func__
, wbc
->nr_to_write
, ret
);
2969 index
+= pages_written
;
2970 wbc
->range_cyclic
= range_cyclic
;
2971 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2973 * set the writeback_index so that range_cyclic
2974 * mode will write it back later
2976 mapping
->writeback_index
= index
;
2979 if (!no_nrwrite_index_update
)
2980 wbc
->no_nrwrite_index_update
= 0;
2981 wbc
->nr_to_write
-= nr_to_writebump
;
2982 wbc
->range_start
= range_start
;
2983 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
2987 #define FALL_BACK_TO_NONDELALLOC 1
2988 static int ext4_nonda_switch(struct super_block
*sb
)
2990 s64 free_blocks
, dirty_blocks
;
2991 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2994 * switch to non delalloc mode if we are running low
2995 * on free block. The free block accounting via percpu
2996 * counters can get slightly wrong with percpu_counter_batch getting
2997 * accumulated on each CPU without updating global counters
2998 * Delalloc need an accurate free block accounting. So switch
2999 * to non delalloc when we are near to error range.
3001 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
3002 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
3003 if (2 * free_blocks
< 3 * dirty_blocks
||
3004 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
3006 * free block count is less than 150% of dirty blocks
3007 * or free blocks is less than watermark
3012 * Even if we don't switch but are nearing capacity,
3013 * start pushing delalloc when 1/2 of free blocks are dirty.
3015 if (free_blocks
< 2 * dirty_blocks
)
3016 writeback_inodes_sb_if_idle(sb
);
3021 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
3022 loff_t pos
, unsigned len
, unsigned flags
,
3023 struct page
**pagep
, void **fsdata
)
3025 int ret
, retries
= 0;
3029 struct inode
*inode
= mapping
->host
;
3032 index
= pos
>> PAGE_CACHE_SHIFT
;
3033 from
= pos
& (PAGE_CACHE_SIZE
- 1);
3036 if (ext4_nonda_switch(inode
->i_sb
)) {
3037 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
3038 return ext4_write_begin(file
, mapping
, pos
,
3039 len
, flags
, pagep
, fsdata
);
3041 *fsdata
= (void *)0;
3042 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
3045 * With delayed allocation, we don't log the i_disksize update
3046 * if there is delayed block allocation. But we still need
3047 * to journalling the i_disksize update if writes to the end
3048 * of file which has an already mapped buffer.
3050 handle
= ext4_journal_start(inode
, 1);
3051 if (IS_ERR(handle
)) {
3052 ret
= PTR_ERR(handle
);
3055 /* We cannot recurse into the filesystem as the transaction is already
3057 flags
|= AOP_FLAG_NOFS
;
3059 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
3061 ext4_journal_stop(handle
);
3067 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
3068 ext4_da_get_block_prep
);
3071 ext4_journal_stop(handle
);
3072 page_cache_release(page
);
3074 * block_write_begin may have instantiated a few blocks
3075 * outside i_size. Trim these off again. Don't need
3076 * i_size_read because we hold i_mutex.
3078 if (pos
+ len
> inode
->i_size
)
3079 ext4_truncate_failed_write(inode
);
3082 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3089 * Check if we should update i_disksize
3090 * when write to the end of file but not require block allocation
3092 static int ext4_da_should_update_i_disksize(struct page
*page
,
3093 unsigned long offset
)
3095 struct buffer_head
*bh
;
3096 struct inode
*inode
= page
->mapping
->host
;
3100 bh
= page_buffers(page
);
3101 idx
= offset
>> inode
->i_blkbits
;
3103 for (i
= 0; i
< idx
; i
++)
3104 bh
= bh
->b_this_page
;
3106 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
3111 static int ext4_da_write_end(struct file
*file
,
3112 struct address_space
*mapping
,
3113 loff_t pos
, unsigned len
, unsigned copied
,
3114 struct page
*page
, void *fsdata
)
3116 struct inode
*inode
= mapping
->host
;
3118 handle_t
*handle
= ext4_journal_current_handle();
3120 unsigned long start
, end
;
3121 int write_mode
= (int)(unsigned long)fsdata
;
3123 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
3124 if (ext4_should_order_data(inode
)) {
3125 return ext4_ordered_write_end(file
, mapping
, pos
,
3126 len
, copied
, page
, fsdata
);
3127 } else if (ext4_should_writeback_data(inode
)) {
3128 return ext4_writeback_write_end(file
, mapping
, pos
,
3129 len
, copied
, page
, fsdata
);
3135 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
3136 start
= pos
& (PAGE_CACHE_SIZE
- 1);
3137 end
= start
+ copied
- 1;
3140 * generic_write_end() will run mark_inode_dirty() if i_size
3141 * changes. So let's piggyback the i_disksize mark_inode_dirty
3145 new_i_size
= pos
+ copied
;
3146 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3147 if (ext4_da_should_update_i_disksize(page
, end
)) {
3148 down_write(&EXT4_I(inode
)->i_data_sem
);
3149 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3151 * Updating i_disksize when extending file
3152 * without needing block allocation
3154 if (ext4_should_order_data(inode
))
3155 ret
= ext4_jbd2_file_inode(handle
,
3158 EXT4_I(inode
)->i_disksize
= new_i_size
;
3160 up_write(&EXT4_I(inode
)->i_data_sem
);
3161 /* We need to mark inode dirty even if
3162 * new_i_size is less that inode->i_size
3163 * bu greater than i_disksize.(hint delalloc)
3165 ext4_mark_inode_dirty(handle
, inode
);
3168 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
3173 ret2
= ext4_journal_stop(handle
);
3177 return ret
? ret
: copied
;
3180 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
3183 * Drop reserved blocks
3185 BUG_ON(!PageLocked(page
));
3186 if (!page_has_buffers(page
))
3189 ext4_da_page_release_reservation(page
, offset
);
3192 ext4_invalidatepage(page
, offset
);
3198 * Force all delayed allocation blocks to be allocated for a given inode.
3200 int ext4_alloc_da_blocks(struct inode
*inode
)
3202 trace_ext4_alloc_da_blocks(inode
);
3204 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
3205 !EXT4_I(inode
)->i_reserved_meta_blocks
)
3209 * We do something simple for now. The filemap_flush() will
3210 * also start triggering a write of the data blocks, which is
3211 * not strictly speaking necessary (and for users of
3212 * laptop_mode, not even desirable). However, to do otherwise
3213 * would require replicating code paths in:
3215 * ext4_da_writepages() ->
3216 * write_cache_pages() ---> (via passed in callback function)
3217 * __mpage_da_writepage() -->
3218 * mpage_add_bh_to_extent()
3219 * mpage_da_map_blocks()
3221 * The problem is that write_cache_pages(), located in
3222 * mm/page-writeback.c, marks pages clean in preparation for
3223 * doing I/O, which is not desirable if we're not planning on
3226 * We could call write_cache_pages(), and then redirty all of
3227 * the pages by calling redirty_page_for_writeback() but that
3228 * would be ugly in the extreme. So instead we would need to
3229 * replicate parts of the code in the above functions,
3230 * simplifying them becuase we wouldn't actually intend to
3231 * write out the pages, but rather only collect contiguous
3232 * logical block extents, call the multi-block allocator, and
3233 * then update the buffer heads with the block allocations.
3235 * For now, though, we'll cheat by calling filemap_flush(),
3236 * which will map the blocks, and start the I/O, but not
3237 * actually wait for the I/O to complete.
3239 return filemap_flush(inode
->i_mapping
);
3243 * bmap() is special. It gets used by applications such as lilo and by
3244 * the swapper to find the on-disk block of a specific piece of data.
3246 * Naturally, this is dangerous if the block concerned is still in the
3247 * journal. If somebody makes a swapfile on an ext4 data-journaling
3248 * filesystem and enables swap, then they may get a nasty shock when the
3249 * data getting swapped to that swapfile suddenly gets overwritten by
3250 * the original zero's written out previously to the journal and
3251 * awaiting writeback in the kernel's buffer cache.
3253 * So, if we see any bmap calls here on a modified, data-journaled file,
3254 * take extra steps to flush any blocks which might be in the cache.
3256 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
3258 struct inode
*inode
= mapping
->host
;
3262 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
3263 test_opt(inode
->i_sb
, DELALLOC
)) {
3265 * With delalloc we want to sync the file
3266 * so that we can make sure we allocate
3269 filemap_write_and_wait(mapping
);
3272 if (EXT4_JOURNAL(inode
) && EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
3274 * This is a REALLY heavyweight approach, but the use of
3275 * bmap on dirty files is expected to be extremely rare:
3276 * only if we run lilo or swapon on a freshly made file
3277 * do we expect this to happen.
3279 * (bmap requires CAP_SYS_RAWIO so this does not
3280 * represent an unprivileged user DOS attack --- we'd be
3281 * in trouble if mortal users could trigger this path at
3284 * NB. EXT4_STATE_JDATA is not set on files other than
3285 * regular files. If somebody wants to bmap a directory
3286 * or symlink and gets confused because the buffer
3287 * hasn't yet been flushed to disk, they deserve
3288 * everything they get.
3291 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
3292 journal
= EXT4_JOURNAL(inode
);
3293 jbd2_journal_lock_updates(journal
);
3294 err
= jbd2_journal_flush(journal
);
3295 jbd2_journal_unlock_updates(journal
);
3301 return generic_block_bmap(mapping
, block
, ext4_get_block
);
3304 static int ext4_readpage(struct file
*file
, struct page
*page
)
3306 return mpage_readpage(page
, ext4_get_block
);
3310 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3311 struct list_head
*pages
, unsigned nr_pages
)
3313 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3316 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3318 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3321 * If it's a full truncate we just forget about the pending dirtying
3324 ClearPageChecked(page
);
3327 jbd2_journal_invalidatepage(journal
, page
, offset
);
3329 block_invalidatepage(page
, offset
);
3332 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3334 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3336 WARN_ON(PageChecked(page
));
3337 if (!page_has_buffers(page
))
3340 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3342 return try_to_free_buffers(page
);
3346 * O_DIRECT for ext3 (or indirect map) based files
3348 * If the O_DIRECT write will extend the file then add this inode to the
3349 * orphan list. So recovery will truncate it back to the original size
3350 * if the machine crashes during the write.
3352 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3353 * crashes then stale disk data _may_ be exposed inside the file. But current
3354 * VFS code falls back into buffered path in that case so we are safe.
3356 static ssize_t
ext4_ind_direct_IO(int rw
, struct kiocb
*iocb
,
3357 const struct iovec
*iov
, loff_t offset
,
3358 unsigned long nr_segs
)
3360 struct file
*file
= iocb
->ki_filp
;
3361 struct inode
*inode
= file
->f_mapping
->host
;
3362 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3366 size_t count
= iov_length(iov
, nr_segs
);
3370 loff_t final_size
= offset
+ count
;
3372 if (final_size
> inode
->i_size
) {
3373 /* Credits for sb + inode write */
3374 handle
= ext4_journal_start(inode
, 2);
3375 if (IS_ERR(handle
)) {
3376 ret
= PTR_ERR(handle
);
3379 ret
= ext4_orphan_add(handle
, inode
);
3381 ext4_journal_stop(handle
);
3385 ei
->i_disksize
= inode
->i_size
;
3386 ext4_journal_stop(handle
);
3391 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3393 ext4_get_block
, NULL
);
3394 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3400 /* Credits for sb + inode write */
3401 handle
= ext4_journal_start(inode
, 2);
3402 if (IS_ERR(handle
)) {
3403 /* This is really bad luck. We've written the data
3404 * but cannot extend i_size. Bail out and pretend
3405 * the write failed... */
3406 ret
= PTR_ERR(handle
);
3410 ext4_orphan_del(handle
, inode
);
3412 loff_t end
= offset
+ ret
;
3413 if (end
> inode
->i_size
) {
3414 ei
->i_disksize
= end
;
3415 i_size_write(inode
, end
);
3417 * We're going to return a positive `ret'
3418 * here due to non-zero-length I/O, so there's
3419 * no way of reporting error returns from
3420 * ext4_mark_inode_dirty() to userspace. So
3423 ext4_mark_inode_dirty(handle
, inode
);
3426 err
= ext4_journal_stop(handle
);
3434 static int ext4_get_block_dio_write(struct inode
*inode
, sector_t iblock
,
3435 struct buffer_head
*bh_result
, int create
)
3437 handle_t
*handle
= NULL
;
3439 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
3442 ext4_debug("ext4_get_block_dio_write: inode %lu, create flag %d\n",
3443 inode
->i_ino
, create
);
3445 * DIO VFS code passes create = 0 flag for write to
3446 * the middle of file. It does this to avoid block
3447 * allocation for holes, to prevent expose stale data
3448 * out when there is parallel buffered read (which does
3449 * not hold the i_mutex lock) while direct IO write has
3450 * not completed. DIO request on holes finally falls back
3451 * to buffered IO for this reason.
3453 * For ext4 extent based file, since we support fallocate,
3454 * new allocated extent as uninitialized, for holes, we
3455 * could fallocate blocks for holes, thus parallel
3456 * buffered IO read will zero out the page when read on
3457 * a hole while parallel DIO write to the hole has not completed.
3459 * when we come here, we know it's a direct IO write to
3460 * to the middle of file (<i_size)
3461 * so it's safe to override the create flag from VFS.
3463 create
= EXT4_GET_BLOCKS_DIO_CREATE_EXT
;
3465 if (max_blocks
> DIO_MAX_BLOCKS
)
3466 max_blocks
= DIO_MAX_BLOCKS
;
3467 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
3468 handle
= ext4_journal_start(inode
, dio_credits
);
3469 if (IS_ERR(handle
)) {
3470 ret
= PTR_ERR(handle
);
3473 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
3476 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
3479 ext4_journal_stop(handle
);
3484 static void ext4_free_io_end(ext4_io_end_t
*io
)
3490 static void dump_aio_dio_list(struct inode
* inode
)
3493 struct list_head
*cur
, *before
, *after
;
3494 ext4_io_end_t
*io
, *io0
, *io1
;
3496 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3497 ext4_debug("inode %lu aio dio list is empty\n", inode
->i_ino
);
3501 ext4_debug("Dump inode %lu aio_dio_completed_IO list \n", inode
->i_ino
);
3502 list_for_each_entry(io
, &EXT4_I(inode
)->i_aio_dio_complete_list
, list
){
3505 io0
= container_of(before
, ext4_io_end_t
, list
);
3507 io1
= container_of(after
, ext4_io_end_t
, list
);
3509 ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
3510 io
, inode
->i_ino
, io0
, io1
);
3516 * check a range of space and convert unwritten extents to written.
3518 static int ext4_end_aio_dio_nolock(ext4_io_end_t
*io
)
3520 struct inode
*inode
= io
->inode
;
3521 loff_t offset
= io
->offset
;
3522 size_t size
= io
->size
;
3525 ext4_debug("end_aio_dio_onlock: io 0x%p from inode %lu,list->next 0x%p,"
3526 "list->prev 0x%p\n",
3527 io
, inode
->i_ino
, io
->list
.next
, io
->list
.prev
);
3529 if (list_empty(&io
->list
))
3532 if (io
->flag
!= DIO_AIO_UNWRITTEN
)
3535 if (offset
+ size
<= i_size_read(inode
))
3536 ret
= ext4_convert_unwritten_extents(inode
, offset
, size
);
3539 printk(KERN_EMERG
"%s: failed to convert unwritten"
3540 "extents to written extents, error is %d"
3541 " io is still on inode %lu aio dio list\n",
3542 __func__
, ret
, inode
->i_ino
);
3546 /* clear the DIO AIO unwritten flag */
3551 * work on completed aio dio IO, to convert unwritten extents to extents
3553 static void ext4_end_aio_dio_work(struct work_struct
*work
)
3555 ext4_io_end_t
*io
= container_of(work
, ext4_io_end_t
, work
);
3556 struct inode
*inode
= io
->inode
;
3559 mutex_lock(&inode
->i_mutex
);
3560 ret
= ext4_end_aio_dio_nolock(io
);
3562 if (!list_empty(&io
->list
))
3563 list_del_init(&io
->list
);
3564 ext4_free_io_end(io
);
3566 mutex_unlock(&inode
->i_mutex
);
3569 * This function is called from ext4_sync_file().
3571 * When AIO DIO IO is completed, the work to convert unwritten
3572 * extents to written is queued on workqueue but may not get immediately
3573 * scheduled. When fsync is called, we need to ensure the
3574 * conversion is complete before fsync returns.
3575 * The inode keeps track of a list of completed AIO from DIO path
3576 * that might needs to do the conversion. This function walks through
3577 * the list and convert the related unwritten extents to written.
3579 int flush_aio_dio_completed_IO(struct inode
*inode
)
3585 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
))
3588 dump_aio_dio_list(inode
);
3589 while (!list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3590 io
= list_entry(EXT4_I(inode
)->i_aio_dio_complete_list
.next
,
3591 ext4_io_end_t
, list
);
3593 * Calling ext4_end_aio_dio_nolock() to convert completed
3596 * When ext4_sync_file() is called, run_queue() may already
3597 * about to flush the work corresponding to this io structure.
3598 * It will be upset if it founds the io structure related
3599 * to the work-to-be schedule is freed.
3601 * Thus we need to keep the io structure still valid here after
3602 * convertion finished. The io structure has a flag to
3603 * avoid double converting from both fsync and background work
3606 ret
= ext4_end_aio_dio_nolock(io
);
3610 list_del_init(&io
->list
);
3612 return (ret2
< 0) ? ret2
: 0;
3615 static ext4_io_end_t
*ext4_init_io_end (struct inode
*inode
)
3617 ext4_io_end_t
*io
= NULL
;
3619 io
= kmalloc(sizeof(*io
), GFP_NOFS
);
3628 INIT_WORK(&io
->work
, ext4_end_aio_dio_work
);
3629 INIT_LIST_HEAD(&io
->list
);
3635 static void ext4_end_io_dio(struct kiocb
*iocb
, loff_t offset
,
3636 ssize_t size
, void *private)
3638 ext4_io_end_t
*io_end
= iocb
->private;
3639 struct workqueue_struct
*wq
;
3641 /* if not async direct IO or dio with 0 bytes write, just return */
3642 if (!io_end
|| !size
)
3645 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3646 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3647 iocb
->private, io_end
->inode
->i_ino
, iocb
, offset
,
3650 /* if not aio dio with unwritten extents, just free io and return */
3651 if (io_end
->flag
!= DIO_AIO_UNWRITTEN
){
3652 ext4_free_io_end(io_end
);
3653 iocb
->private = NULL
;
3657 io_end
->offset
= offset
;
3658 io_end
->size
= size
;
3659 wq
= EXT4_SB(io_end
->inode
->i_sb
)->dio_unwritten_wq
;
3661 /* queue the work to convert unwritten extents to written */
3662 queue_work(wq
, &io_end
->work
);
3664 /* Add the io_end to per-inode completed aio dio list*/
3665 list_add_tail(&io_end
->list
,
3666 &EXT4_I(io_end
->inode
)->i_aio_dio_complete_list
);
3667 iocb
->private = NULL
;
3670 * For ext4 extent files, ext4 will do direct-io write to holes,
3671 * preallocated extents, and those write extend the file, no need to
3672 * fall back to buffered IO.
3674 * For holes, we fallocate those blocks, mark them as unintialized
3675 * If those blocks were preallocated, we mark sure they are splited, but
3676 * still keep the range to write as unintialized.
3678 * The unwrritten extents will be converted to written when DIO is completed.
3679 * For async direct IO, since the IO may still pending when return, we
3680 * set up an end_io call back function, which will do the convertion
3681 * when async direct IO completed.
3683 * If the O_DIRECT write will extend the file then add this inode to the
3684 * orphan list. So recovery will truncate it back to the original size
3685 * if the machine crashes during the write.
3688 static ssize_t
ext4_ext_direct_IO(int rw
, struct kiocb
*iocb
,
3689 const struct iovec
*iov
, loff_t offset
,
3690 unsigned long nr_segs
)
3692 struct file
*file
= iocb
->ki_filp
;
3693 struct inode
*inode
= file
->f_mapping
->host
;
3695 size_t count
= iov_length(iov
, nr_segs
);
3697 loff_t final_size
= offset
+ count
;
3698 if (rw
== WRITE
&& final_size
<= inode
->i_size
) {
3700 * We could direct write to holes and fallocate.
3702 * Allocated blocks to fill the hole are marked as uninitialized
3703 * to prevent paralel buffered read to expose the stale data
3704 * before DIO complete the data IO.
3706 * As to previously fallocated extents, ext4 get_block
3707 * will just simply mark the buffer mapped but still
3708 * keep the extents uninitialized.
3710 * for non AIO case, we will convert those unwritten extents
3711 * to written after return back from blockdev_direct_IO.
3713 * for async DIO, the conversion needs to be defered when
3714 * the IO is completed. The ext4 end_io callback function
3715 * will be called to take care of the conversion work.
3716 * Here for async case, we allocate an io_end structure to
3719 iocb
->private = NULL
;
3720 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3721 if (!is_sync_kiocb(iocb
)) {
3722 iocb
->private = ext4_init_io_end(inode
);
3726 * we save the io structure for current async
3727 * direct IO, so that later ext4_get_blocks()
3728 * could flag the io structure whether there
3729 * is a unwritten extents needs to be converted
3730 * when IO is completed.
3732 EXT4_I(inode
)->cur_aio_dio
= iocb
->private;
3735 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3736 inode
->i_sb
->s_bdev
, iov
,
3738 ext4_get_block_dio_write
,
3741 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3743 * The io_end structure takes a reference to the inode,
3744 * that structure needs to be destroyed and the
3745 * reference to the inode need to be dropped, when IO is
3746 * complete, even with 0 byte write, or failed.
3748 * In the successful AIO DIO case, the io_end structure will be
3749 * desctroyed and the reference to the inode will be dropped
3750 * after the end_io call back function is called.
3752 * In the case there is 0 byte write, or error case, since
3753 * VFS direct IO won't invoke the end_io call back function,
3754 * we need to free the end_io structure here.
3756 if (ret
!= -EIOCBQUEUED
&& ret
<= 0 && iocb
->private) {
3757 ext4_free_io_end(iocb
->private);
3758 iocb
->private = NULL
;
3759 } else if (ret
> 0 && (EXT4_I(inode
)->i_state
&
3760 EXT4_STATE_DIO_UNWRITTEN
)) {
3763 * for non AIO case, since the IO is already
3764 * completed, we could do the convertion right here
3766 err
= ext4_convert_unwritten_extents(inode
,
3770 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_DIO_UNWRITTEN
;
3775 /* for write the the end of file case, we fall back to old way */
3776 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3779 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3780 const struct iovec
*iov
, loff_t offset
,
3781 unsigned long nr_segs
)
3783 struct file
*file
= iocb
->ki_filp
;
3784 struct inode
*inode
= file
->f_mapping
->host
;
3786 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
3787 return ext4_ext_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3789 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3793 * Pages can be marked dirty completely asynchronously from ext4's journalling
3794 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3795 * much here because ->set_page_dirty is called under VFS locks. The page is
3796 * not necessarily locked.
3798 * We cannot just dirty the page and leave attached buffers clean, because the
3799 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3800 * or jbddirty because all the journalling code will explode.
3802 * So what we do is to mark the page "pending dirty" and next time writepage
3803 * is called, propagate that into the buffers appropriately.
3805 static int ext4_journalled_set_page_dirty(struct page
*page
)
3807 SetPageChecked(page
);
3808 return __set_page_dirty_nobuffers(page
);
3811 static const struct address_space_operations ext4_ordered_aops
= {
3812 .readpage
= ext4_readpage
,
3813 .readpages
= ext4_readpages
,
3814 .writepage
= ext4_writepage
,
3815 .sync_page
= block_sync_page
,
3816 .write_begin
= ext4_write_begin
,
3817 .write_end
= ext4_ordered_write_end
,
3819 .invalidatepage
= ext4_invalidatepage
,
3820 .releasepage
= ext4_releasepage
,
3821 .direct_IO
= ext4_direct_IO
,
3822 .migratepage
= buffer_migrate_page
,
3823 .is_partially_uptodate
= block_is_partially_uptodate
,
3824 .error_remove_page
= generic_error_remove_page
,
3827 static const struct address_space_operations ext4_writeback_aops
= {
3828 .readpage
= ext4_readpage
,
3829 .readpages
= ext4_readpages
,
3830 .writepage
= ext4_writepage
,
3831 .sync_page
= block_sync_page
,
3832 .write_begin
= ext4_write_begin
,
3833 .write_end
= ext4_writeback_write_end
,
3835 .invalidatepage
= ext4_invalidatepage
,
3836 .releasepage
= ext4_releasepage
,
3837 .direct_IO
= ext4_direct_IO
,
3838 .migratepage
= buffer_migrate_page
,
3839 .is_partially_uptodate
= block_is_partially_uptodate
,
3840 .error_remove_page
= generic_error_remove_page
,
3843 static const struct address_space_operations ext4_journalled_aops
= {
3844 .readpage
= ext4_readpage
,
3845 .readpages
= ext4_readpages
,
3846 .writepage
= ext4_writepage
,
3847 .sync_page
= block_sync_page
,
3848 .write_begin
= ext4_write_begin
,
3849 .write_end
= ext4_journalled_write_end
,
3850 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3852 .invalidatepage
= ext4_invalidatepage
,
3853 .releasepage
= ext4_releasepage
,
3854 .is_partially_uptodate
= block_is_partially_uptodate
,
3855 .error_remove_page
= generic_error_remove_page
,
3858 static const struct address_space_operations ext4_da_aops
= {
3859 .readpage
= ext4_readpage
,
3860 .readpages
= ext4_readpages
,
3861 .writepage
= ext4_writepage
,
3862 .writepages
= ext4_da_writepages
,
3863 .sync_page
= block_sync_page
,
3864 .write_begin
= ext4_da_write_begin
,
3865 .write_end
= ext4_da_write_end
,
3867 .invalidatepage
= ext4_da_invalidatepage
,
3868 .releasepage
= ext4_releasepage
,
3869 .direct_IO
= ext4_direct_IO
,
3870 .migratepage
= buffer_migrate_page
,
3871 .is_partially_uptodate
= block_is_partially_uptodate
,
3872 .error_remove_page
= generic_error_remove_page
,
3875 void ext4_set_aops(struct inode
*inode
)
3877 if (ext4_should_order_data(inode
) &&
3878 test_opt(inode
->i_sb
, DELALLOC
))
3879 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3880 else if (ext4_should_order_data(inode
))
3881 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3882 else if (ext4_should_writeback_data(inode
) &&
3883 test_opt(inode
->i_sb
, DELALLOC
))
3884 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3885 else if (ext4_should_writeback_data(inode
))
3886 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3888 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3892 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3893 * up to the end of the block which corresponds to `from'.
3894 * This required during truncate. We need to physically zero the tail end
3895 * of that block so it doesn't yield old data if the file is later grown.
3897 int ext4_block_truncate_page(handle_t
*handle
,
3898 struct address_space
*mapping
, loff_t from
)
3900 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3901 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3902 unsigned blocksize
, length
, pos
;
3904 struct inode
*inode
= mapping
->host
;
3905 struct buffer_head
*bh
;
3909 page
= find_or_create_page(mapping
, from
>> PAGE_CACHE_SHIFT
,
3910 mapping_gfp_mask(mapping
) & ~__GFP_FS
);
3914 blocksize
= inode
->i_sb
->s_blocksize
;
3915 length
= blocksize
- (offset
& (blocksize
- 1));
3916 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3919 * For "nobh" option, we can only work if we don't need to
3920 * read-in the page - otherwise we create buffers to do the IO.
3922 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3923 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3924 zero_user(page
, offset
, length
);
3925 set_page_dirty(page
);
3929 if (!page_has_buffers(page
))
3930 create_empty_buffers(page
, blocksize
, 0);
3932 /* Find the buffer that contains "offset" */
3933 bh
= page_buffers(page
);
3935 while (offset
>= pos
) {
3936 bh
= bh
->b_this_page
;
3942 if (buffer_freed(bh
)) {
3943 BUFFER_TRACE(bh
, "freed: skip");
3947 if (!buffer_mapped(bh
)) {
3948 BUFFER_TRACE(bh
, "unmapped");
3949 ext4_get_block(inode
, iblock
, bh
, 0);
3950 /* unmapped? It's a hole - nothing to do */
3951 if (!buffer_mapped(bh
)) {
3952 BUFFER_TRACE(bh
, "still unmapped");
3957 /* Ok, it's mapped. Make sure it's up-to-date */
3958 if (PageUptodate(page
))
3959 set_buffer_uptodate(bh
);
3961 if (!buffer_uptodate(bh
)) {
3963 ll_rw_block(READ
, 1, &bh
);
3965 /* Uhhuh. Read error. Complain and punt. */
3966 if (!buffer_uptodate(bh
))
3970 if (ext4_should_journal_data(inode
)) {
3971 BUFFER_TRACE(bh
, "get write access");
3972 err
= ext4_journal_get_write_access(handle
, bh
);
3977 zero_user(page
, offset
, length
);
3979 BUFFER_TRACE(bh
, "zeroed end of block");
3982 if (ext4_should_journal_data(inode
)) {
3983 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
3985 if (ext4_should_order_data(inode
))
3986 err
= ext4_jbd2_file_inode(handle
, inode
);
3987 mark_buffer_dirty(bh
);
3992 page_cache_release(page
);
3997 * Probably it should be a library function... search for first non-zero word
3998 * or memcmp with zero_page, whatever is better for particular architecture.
4001 static inline int all_zeroes(__le32
*p
, __le32
*q
)
4010 * ext4_find_shared - find the indirect blocks for partial truncation.
4011 * @inode: inode in question
4012 * @depth: depth of the affected branch
4013 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4014 * @chain: place to store the pointers to partial indirect blocks
4015 * @top: place to the (detached) top of branch
4017 * This is a helper function used by ext4_truncate().
4019 * When we do truncate() we may have to clean the ends of several
4020 * indirect blocks but leave the blocks themselves alive. Block is
4021 * partially truncated if some data below the new i_size is refered
4022 * from it (and it is on the path to the first completely truncated
4023 * data block, indeed). We have to free the top of that path along
4024 * with everything to the right of the path. Since no allocation
4025 * past the truncation point is possible until ext4_truncate()
4026 * finishes, we may safely do the latter, but top of branch may
4027 * require special attention - pageout below the truncation point
4028 * might try to populate it.
4030 * We atomically detach the top of branch from the tree, store the
4031 * block number of its root in *@top, pointers to buffer_heads of
4032 * partially truncated blocks - in @chain[].bh and pointers to
4033 * their last elements that should not be removed - in
4034 * @chain[].p. Return value is the pointer to last filled element
4037 * The work left to caller to do the actual freeing of subtrees:
4038 * a) free the subtree starting from *@top
4039 * b) free the subtrees whose roots are stored in
4040 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4041 * c) free the subtrees growing from the inode past the @chain[0].
4042 * (no partially truncated stuff there). */
4044 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
4045 ext4_lblk_t offsets
[4], Indirect chain
[4],
4048 Indirect
*partial
, *p
;
4052 /* Make k index the deepest non-null offset + 1 */
4053 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
4055 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
4056 /* Writer: pointers */
4058 partial
= chain
+ k
-1;
4060 * If the branch acquired continuation since we've looked at it -
4061 * fine, it should all survive and (new) top doesn't belong to us.
4063 if (!partial
->key
&& *partial
->p
)
4066 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
4069 * OK, we've found the last block that must survive. The rest of our
4070 * branch should be detached before unlocking. However, if that rest
4071 * of branch is all ours and does not grow immediately from the inode
4072 * it's easier to cheat and just decrement partial->p.
4074 if (p
== chain
+ k
- 1 && p
> chain
) {
4078 /* Nope, don't do this in ext4. Must leave the tree intact */
4085 while (partial
> p
) {
4086 brelse(partial
->bh
);
4094 * Zero a number of block pointers in either an inode or an indirect block.
4095 * If we restart the transaction we must again get write access to the
4096 * indirect block for further modification.
4098 * We release `count' blocks on disk, but (last - first) may be greater
4099 * than `count' because there can be holes in there.
4101 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
4102 struct buffer_head
*bh
,
4103 ext4_fsblk_t block_to_free
,
4104 unsigned long count
, __le32
*first
,
4108 int flags
= EXT4_FREE_BLOCKS_FORGET
;
4110 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
4111 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4113 if (try_to_extend_transaction(handle
, inode
)) {
4115 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4116 ext4_handle_dirty_metadata(handle
, inode
, bh
);
4118 ext4_mark_inode_dirty(handle
, inode
);
4119 ext4_truncate_restart_trans(handle
, inode
,
4120 blocks_for_truncate(inode
));
4122 BUFFER_TRACE(bh
, "retaking write access");
4123 ext4_journal_get_write_access(handle
, bh
);
4127 for (p
= first
; p
< last
; p
++)
4130 ext4_free_blocks(handle
, inode
, 0, block_to_free
, count
, flags
);
4134 * ext4_free_data - free a list of data blocks
4135 * @handle: handle for this transaction
4136 * @inode: inode we are dealing with
4137 * @this_bh: indirect buffer_head which contains *@first and *@last
4138 * @first: array of block numbers
4139 * @last: points immediately past the end of array
4141 * We are freeing all blocks refered from that array (numbers are stored as
4142 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4144 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4145 * blocks are contiguous then releasing them at one time will only affect one
4146 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4147 * actually use a lot of journal space.
4149 * @this_bh will be %NULL if @first and @last point into the inode's direct
4152 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
4153 struct buffer_head
*this_bh
,
4154 __le32
*first
, __le32
*last
)
4156 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
4157 unsigned long count
= 0; /* Number of blocks in the run */
4158 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
4161 ext4_fsblk_t nr
; /* Current block # */
4162 __le32
*p
; /* Pointer into inode/ind
4163 for current block */
4166 if (this_bh
) { /* For indirect block */
4167 BUFFER_TRACE(this_bh
, "get_write_access");
4168 err
= ext4_journal_get_write_access(handle
, this_bh
);
4169 /* Important: if we can't update the indirect pointers
4170 * to the blocks, we can't free them. */
4175 for (p
= first
; p
< last
; p
++) {
4176 nr
= le32_to_cpu(*p
);
4178 /* accumulate blocks to free if they're contiguous */
4181 block_to_free_p
= p
;
4183 } else if (nr
== block_to_free
+ count
) {
4186 ext4_clear_blocks(handle
, inode
, this_bh
,
4188 count
, block_to_free_p
, p
);
4190 block_to_free_p
= p
;
4197 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
4198 count
, block_to_free_p
, p
);
4201 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
4204 * The buffer head should have an attached journal head at this
4205 * point. However, if the data is corrupted and an indirect
4206 * block pointed to itself, it would have been detached when
4207 * the block was cleared. Check for this instead of OOPSing.
4209 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
4210 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
4212 ext4_error(inode
->i_sb
, __func__
,
4213 "circular indirect block detected, "
4214 "inode=%lu, block=%llu",
4216 (unsigned long long) this_bh
->b_blocknr
);
4221 * ext4_free_branches - free an array of branches
4222 * @handle: JBD handle for this transaction
4223 * @inode: inode we are dealing with
4224 * @parent_bh: the buffer_head which contains *@first and *@last
4225 * @first: array of block numbers
4226 * @last: pointer immediately past the end of array
4227 * @depth: depth of the branches to free
4229 * We are freeing all blocks refered from these branches (numbers are
4230 * stored as little-endian 32-bit) and updating @inode->i_blocks
4233 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
4234 struct buffer_head
*parent_bh
,
4235 __le32
*first
, __le32
*last
, int depth
)
4240 if (ext4_handle_is_aborted(handle
))
4244 struct buffer_head
*bh
;
4245 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4247 while (--p
>= first
) {
4248 nr
= le32_to_cpu(*p
);
4250 continue; /* A hole */
4252 /* Go read the buffer for the next level down */
4253 bh
= sb_bread(inode
->i_sb
, nr
);
4256 * A read failure? Report error and clear slot
4260 ext4_error(inode
->i_sb
, "ext4_free_branches",
4261 "Read failure, inode=%lu, block=%llu",
4266 /* This zaps the entire block. Bottom up. */
4267 BUFFER_TRACE(bh
, "free child branches");
4268 ext4_free_branches(handle
, inode
, bh
,
4269 (__le32
*) bh
->b_data
,
4270 (__le32
*) bh
->b_data
+ addr_per_block
,
4274 * We've probably journalled the indirect block several
4275 * times during the truncate. But it's no longer
4276 * needed and we now drop it from the transaction via
4277 * jbd2_journal_revoke().
4279 * That's easy if it's exclusively part of this
4280 * transaction. But if it's part of the committing
4281 * transaction then jbd2_journal_forget() will simply
4282 * brelse() it. That means that if the underlying
4283 * block is reallocated in ext4_get_block(),
4284 * unmap_underlying_metadata() will find this block
4285 * and will try to get rid of it. damn, damn.
4287 * If this block has already been committed to the
4288 * journal, a revoke record will be written. And
4289 * revoke records must be emitted *before* clearing
4290 * this block's bit in the bitmaps.
4292 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
4295 * Everything below this this pointer has been
4296 * released. Now let this top-of-subtree go.
4298 * We want the freeing of this indirect block to be
4299 * atomic in the journal with the updating of the
4300 * bitmap block which owns it. So make some room in
4303 * We zero the parent pointer *after* freeing its
4304 * pointee in the bitmaps, so if extend_transaction()
4305 * for some reason fails to put the bitmap changes and
4306 * the release into the same transaction, recovery
4307 * will merely complain about releasing a free block,
4308 * rather than leaking blocks.
4310 if (ext4_handle_is_aborted(handle
))
4312 if (try_to_extend_transaction(handle
, inode
)) {
4313 ext4_mark_inode_dirty(handle
, inode
);
4314 ext4_truncate_restart_trans(handle
, inode
,
4315 blocks_for_truncate(inode
));
4318 ext4_free_blocks(handle
, inode
, 0, nr
, 1,
4319 EXT4_FREE_BLOCKS_METADATA
);
4323 * The block which we have just freed is
4324 * pointed to by an indirect block: journal it
4326 BUFFER_TRACE(parent_bh
, "get_write_access");
4327 if (!ext4_journal_get_write_access(handle
,
4330 BUFFER_TRACE(parent_bh
,
4331 "call ext4_handle_dirty_metadata");
4332 ext4_handle_dirty_metadata(handle
,
4339 /* We have reached the bottom of the tree. */
4340 BUFFER_TRACE(parent_bh
, "free data blocks");
4341 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
4345 int ext4_can_truncate(struct inode
*inode
)
4347 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
4349 if (S_ISREG(inode
->i_mode
))
4351 if (S_ISDIR(inode
->i_mode
))
4353 if (S_ISLNK(inode
->i_mode
))
4354 return !ext4_inode_is_fast_symlink(inode
);
4361 * We block out ext4_get_block() block instantiations across the entire
4362 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4363 * simultaneously on behalf of the same inode.
4365 * As we work through the truncate and commmit bits of it to the journal there
4366 * is one core, guiding principle: the file's tree must always be consistent on
4367 * disk. We must be able to restart the truncate after a crash.
4369 * The file's tree may be transiently inconsistent in memory (although it
4370 * probably isn't), but whenever we close off and commit a journal transaction,
4371 * the contents of (the filesystem + the journal) must be consistent and
4372 * restartable. It's pretty simple, really: bottom up, right to left (although
4373 * left-to-right works OK too).
4375 * Note that at recovery time, journal replay occurs *before* the restart of
4376 * truncate against the orphan inode list.
4378 * The committed inode has the new, desired i_size (which is the same as
4379 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4380 * that this inode's truncate did not complete and it will again call
4381 * ext4_truncate() to have another go. So there will be instantiated blocks
4382 * to the right of the truncation point in a crashed ext4 filesystem. But
4383 * that's fine - as long as they are linked from the inode, the post-crash
4384 * ext4_truncate() run will find them and release them.
4386 void ext4_truncate(struct inode
*inode
)
4389 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4390 __le32
*i_data
= ei
->i_data
;
4391 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4392 struct address_space
*mapping
= inode
->i_mapping
;
4393 ext4_lblk_t offsets
[4];
4398 ext4_lblk_t last_block
;
4399 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
4401 if (!ext4_can_truncate(inode
))
4404 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
4405 ei
->i_state
|= EXT4_STATE_DA_ALLOC_CLOSE
;
4407 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
4408 ext4_ext_truncate(inode
);
4412 handle
= start_transaction(inode
);
4414 return; /* AKPM: return what? */
4416 last_block
= (inode
->i_size
+ blocksize
-1)
4417 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
4419 if (inode
->i_size
& (blocksize
- 1))
4420 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
4423 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
4425 goto out_stop
; /* error */
4428 * OK. This truncate is going to happen. We add the inode to the
4429 * orphan list, so that if this truncate spans multiple transactions,
4430 * and we crash, we will resume the truncate when the filesystem
4431 * recovers. It also marks the inode dirty, to catch the new size.
4433 * Implication: the file must always be in a sane, consistent
4434 * truncatable state while each transaction commits.
4436 if (ext4_orphan_add(handle
, inode
))
4440 * From here we block out all ext4_get_block() callers who want to
4441 * modify the block allocation tree.
4443 down_write(&ei
->i_data_sem
);
4445 ext4_discard_preallocations(inode
);
4448 * The orphan list entry will now protect us from any crash which
4449 * occurs before the truncate completes, so it is now safe to propagate
4450 * the new, shorter inode size (held for now in i_size) into the
4451 * on-disk inode. We do this via i_disksize, which is the value which
4452 * ext4 *really* writes onto the disk inode.
4454 ei
->i_disksize
= inode
->i_size
;
4456 if (n
== 1) { /* direct blocks */
4457 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
4458 i_data
+ EXT4_NDIR_BLOCKS
);
4462 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
4463 /* Kill the top of shared branch (not detached) */
4465 if (partial
== chain
) {
4466 /* Shared branch grows from the inode */
4467 ext4_free_branches(handle
, inode
, NULL
,
4468 &nr
, &nr
+1, (chain
+n
-1) - partial
);
4471 * We mark the inode dirty prior to restart,
4472 * and prior to stop. No need for it here.
4475 /* Shared branch grows from an indirect block */
4476 BUFFER_TRACE(partial
->bh
, "get_write_access");
4477 ext4_free_branches(handle
, inode
, partial
->bh
,
4479 partial
->p
+1, (chain
+n
-1) - partial
);
4482 /* Clear the ends of indirect blocks on the shared branch */
4483 while (partial
> chain
) {
4484 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
4485 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
4486 (chain
+n
-1) - partial
);
4487 BUFFER_TRACE(partial
->bh
, "call brelse");
4488 brelse(partial
->bh
);
4492 /* Kill the remaining (whole) subtrees */
4493 switch (offsets
[0]) {
4495 nr
= i_data
[EXT4_IND_BLOCK
];
4497 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4498 i_data
[EXT4_IND_BLOCK
] = 0;
4500 case EXT4_IND_BLOCK
:
4501 nr
= i_data
[EXT4_DIND_BLOCK
];
4503 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4504 i_data
[EXT4_DIND_BLOCK
] = 0;
4506 case EXT4_DIND_BLOCK
:
4507 nr
= i_data
[EXT4_TIND_BLOCK
];
4509 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4510 i_data
[EXT4_TIND_BLOCK
] = 0;
4512 case EXT4_TIND_BLOCK
:
4516 up_write(&ei
->i_data_sem
);
4517 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4518 ext4_mark_inode_dirty(handle
, inode
);
4521 * In a multi-transaction truncate, we only make the final transaction
4525 ext4_handle_sync(handle
);
4528 * If this was a simple ftruncate(), and the file will remain alive
4529 * then we need to clear up the orphan record which we created above.
4530 * However, if this was a real unlink then we were called by
4531 * ext4_delete_inode(), and we allow that function to clean up the
4532 * orphan info for us.
4535 ext4_orphan_del(handle
, inode
);
4537 ext4_journal_stop(handle
);
4541 * ext4_get_inode_loc returns with an extra refcount against the inode's
4542 * underlying buffer_head on success. If 'in_mem' is true, we have all
4543 * data in memory that is needed to recreate the on-disk version of this
4546 static int __ext4_get_inode_loc(struct inode
*inode
,
4547 struct ext4_iloc
*iloc
, int in_mem
)
4549 struct ext4_group_desc
*gdp
;
4550 struct buffer_head
*bh
;
4551 struct super_block
*sb
= inode
->i_sb
;
4553 int inodes_per_block
, inode_offset
;
4556 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4559 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4560 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4565 * Figure out the offset within the block group inode table
4567 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4568 inode_offset
= ((inode
->i_ino
- 1) %
4569 EXT4_INODES_PER_GROUP(sb
));
4570 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4571 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4573 bh
= sb_getblk(sb
, block
);
4575 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
4576 "inode block - inode=%lu, block=%llu",
4577 inode
->i_ino
, block
);
4580 if (!buffer_uptodate(bh
)) {
4584 * If the buffer has the write error flag, we have failed
4585 * to write out another inode in the same block. In this
4586 * case, we don't have to read the block because we may
4587 * read the old inode data successfully.
4589 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4590 set_buffer_uptodate(bh
);
4592 if (buffer_uptodate(bh
)) {
4593 /* someone brought it uptodate while we waited */
4599 * If we have all information of the inode in memory and this
4600 * is the only valid inode in the block, we need not read the
4604 struct buffer_head
*bitmap_bh
;
4607 start
= inode_offset
& ~(inodes_per_block
- 1);
4609 /* Is the inode bitmap in cache? */
4610 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4615 * If the inode bitmap isn't in cache then the
4616 * optimisation may end up performing two reads instead
4617 * of one, so skip it.
4619 if (!buffer_uptodate(bitmap_bh
)) {
4623 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4624 if (i
== inode_offset
)
4626 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4630 if (i
== start
+ inodes_per_block
) {
4631 /* all other inodes are free, so skip I/O */
4632 memset(bh
->b_data
, 0, bh
->b_size
);
4633 set_buffer_uptodate(bh
);
4641 * If we need to do any I/O, try to pre-readahead extra
4642 * blocks from the inode table.
4644 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4645 ext4_fsblk_t b
, end
, table
;
4648 table
= ext4_inode_table(sb
, gdp
);
4649 /* s_inode_readahead_blks is always a power of 2 */
4650 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4653 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4654 num
= EXT4_INODES_PER_GROUP(sb
);
4655 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4656 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4657 num
-= ext4_itable_unused_count(sb
, gdp
);
4658 table
+= num
/ inodes_per_block
;
4662 sb_breadahead(sb
, b
++);
4666 * There are other valid inodes in the buffer, this inode
4667 * has in-inode xattrs, or we don't have this inode in memory.
4668 * Read the block from disk.
4671 bh
->b_end_io
= end_buffer_read_sync
;
4672 submit_bh(READ_META
, bh
);
4674 if (!buffer_uptodate(bh
)) {
4675 ext4_error(sb
, __func__
,
4676 "unable to read inode block - inode=%lu, "
4677 "block=%llu", inode
->i_ino
, block
);
4687 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4689 /* We have all inode data except xattrs in memory here. */
4690 return __ext4_get_inode_loc(inode
, iloc
,
4691 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4694 void ext4_set_inode_flags(struct inode
*inode
)
4696 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4698 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4699 if (flags
& EXT4_SYNC_FL
)
4700 inode
->i_flags
|= S_SYNC
;
4701 if (flags
& EXT4_APPEND_FL
)
4702 inode
->i_flags
|= S_APPEND
;
4703 if (flags
& EXT4_IMMUTABLE_FL
)
4704 inode
->i_flags
|= S_IMMUTABLE
;
4705 if (flags
& EXT4_NOATIME_FL
)
4706 inode
->i_flags
|= S_NOATIME
;
4707 if (flags
& EXT4_DIRSYNC_FL
)
4708 inode
->i_flags
|= S_DIRSYNC
;
4711 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4712 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4714 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4716 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4717 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4719 ei
->i_flags
|= EXT4_SYNC_FL
;
4720 if (flags
& S_APPEND
)
4721 ei
->i_flags
|= EXT4_APPEND_FL
;
4722 if (flags
& S_IMMUTABLE
)
4723 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4724 if (flags
& S_NOATIME
)
4725 ei
->i_flags
|= EXT4_NOATIME_FL
;
4726 if (flags
& S_DIRSYNC
)
4727 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4730 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4731 struct ext4_inode_info
*ei
)
4734 struct inode
*inode
= &(ei
->vfs_inode
);
4735 struct super_block
*sb
= inode
->i_sb
;
4737 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4738 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4739 /* we are using combined 48 bit field */
4740 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4741 le32_to_cpu(raw_inode
->i_blocks_lo
);
4742 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4743 /* i_blocks represent file system block size */
4744 return i_blocks
<< (inode
->i_blkbits
- 9);
4749 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4753 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4755 struct ext4_iloc iloc
;
4756 struct ext4_inode
*raw_inode
;
4757 struct ext4_inode_info
*ei
;
4758 struct inode
*inode
;
4759 journal_t
*journal
= EXT4_SB(sb
)->s_journal
;
4763 inode
= iget_locked(sb
, ino
);
4765 return ERR_PTR(-ENOMEM
);
4766 if (!(inode
->i_state
& I_NEW
))
4772 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4775 raw_inode
= ext4_raw_inode(&iloc
);
4776 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4777 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4778 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4779 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4780 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4781 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4783 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4786 ei
->i_dir_start_lookup
= 0;
4787 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4788 /* We now have enough fields to check if the inode was active or not.
4789 * This is needed because nfsd might try to access dead inodes
4790 * the test is that same one that e2fsck uses
4791 * NeilBrown 1999oct15
4793 if (inode
->i_nlink
== 0) {
4794 if (inode
->i_mode
== 0 ||
4795 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4796 /* this inode is deleted */
4800 /* The only unlinked inodes we let through here have
4801 * valid i_mode and are being read by the orphan
4802 * recovery code: that's fine, we're about to complete
4803 * the process of deleting those. */
4805 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4806 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4807 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4808 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
4810 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4811 inode
->i_size
= ext4_isize(raw_inode
);
4812 ei
->i_disksize
= inode
->i_size
;
4814 ei
->i_reserved_quota
= 0;
4816 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4817 ei
->i_block_group
= iloc
.block_group
;
4818 ei
->i_last_alloc_group
= ~0;
4820 * NOTE! The in-memory inode i_data array is in little-endian order
4821 * even on big-endian machines: we do NOT byteswap the block numbers!
4823 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4824 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4825 INIT_LIST_HEAD(&ei
->i_orphan
);
4828 * Set transaction id's of transactions that have to be committed
4829 * to finish f[data]sync. We set them to currently running transaction
4830 * as we cannot be sure that the inode or some of its metadata isn't
4831 * part of the transaction - the inode could have been reclaimed and
4832 * now it is reread from disk.
4835 transaction_t
*transaction
;
4838 spin_lock(&journal
->j_state_lock
);
4839 if (journal
->j_running_transaction
)
4840 transaction
= journal
->j_running_transaction
;
4842 transaction
= journal
->j_committing_transaction
;
4844 tid
= transaction
->t_tid
;
4846 tid
= journal
->j_commit_sequence
;
4847 spin_unlock(&journal
->j_state_lock
);
4848 ei
->i_sync_tid
= tid
;
4849 ei
->i_datasync_tid
= tid
;
4852 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4853 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4854 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4855 EXT4_INODE_SIZE(inode
->i_sb
)) {
4859 if (ei
->i_extra_isize
== 0) {
4860 /* The extra space is currently unused. Use it. */
4861 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4862 EXT4_GOOD_OLD_INODE_SIZE
;
4864 __le32
*magic
= (void *)raw_inode
+
4865 EXT4_GOOD_OLD_INODE_SIZE
+
4867 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4868 ei
->i_state
|= EXT4_STATE_XATTR
;
4871 ei
->i_extra_isize
= 0;
4873 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4874 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4875 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4876 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4878 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4879 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4880 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4882 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4886 if (ei
->i_file_acl
&&
4887 !ext4_data_block_valid(EXT4_SB(sb
), ei
->i_file_acl
, 1)) {
4888 ext4_error(sb
, __func__
,
4889 "bad extended attribute block %llu in inode #%lu",
4890 ei
->i_file_acl
, inode
->i_ino
);
4893 } else if (ei
->i_flags
& EXT4_EXTENTS_FL
) {
4894 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4895 (S_ISLNK(inode
->i_mode
) &&
4896 !ext4_inode_is_fast_symlink(inode
)))
4897 /* Validate extent which is part of inode */
4898 ret
= ext4_ext_check_inode(inode
);
4899 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4900 (S_ISLNK(inode
->i_mode
) &&
4901 !ext4_inode_is_fast_symlink(inode
))) {
4902 /* Validate block references which are part of inode */
4903 ret
= ext4_check_inode_blockref(inode
);
4908 if (S_ISREG(inode
->i_mode
)) {
4909 inode
->i_op
= &ext4_file_inode_operations
;
4910 inode
->i_fop
= &ext4_file_operations
;
4911 ext4_set_aops(inode
);
4912 } else if (S_ISDIR(inode
->i_mode
)) {
4913 inode
->i_op
= &ext4_dir_inode_operations
;
4914 inode
->i_fop
= &ext4_dir_operations
;
4915 } else if (S_ISLNK(inode
->i_mode
)) {
4916 if (ext4_inode_is_fast_symlink(inode
)) {
4917 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4918 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4919 sizeof(ei
->i_data
) - 1);
4921 inode
->i_op
= &ext4_symlink_inode_operations
;
4922 ext4_set_aops(inode
);
4924 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
4925 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
4926 inode
->i_op
= &ext4_special_inode_operations
;
4927 if (raw_inode
->i_block
[0])
4928 init_special_inode(inode
, inode
->i_mode
,
4929 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4931 init_special_inode(inode
, inode
->i_mode
,
4932 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4935 ext4_error(inode
->i_sb
, __func__
,
4936 "bogus i_mode (%o) for inode=%lu",
4937 inode
->i_mode
, inode
->i_ino
);
4941 ext4_set_inode_flags(inode
);
4942 unlock_new_inode(inode
);
4948 return ERR_PTR(ret
);
4951 static int ext4_inode_blocks_set(handle_t
*handle
,
4952 struct ext4_inode
*raw_inode
,
4953 struct ext4_inode_info
*ei
)
4955 struct inode
*inode
= &(ei
->vfs_inode
);
4956 u64 i_blocks
= inode
->i_blocks
;
4957 struct super_block
*sb
= inode
->i_sb
;
4959 if (i_blocks
<= ~0U) {
4961 * i_blocks can be represnted in a 32 bit variable
4962 * as multiple of 512 bytes
4964 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4965 raw_inode
->i_blocks_high
= 0;
4966 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4969 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
4972 if (i_blocks
<= 0xffffffffffffULL
) {
4974 * i_blocks can be represented in a 48 bit variable
4975 * as multiple of 512 bytes
4977 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4978 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4979 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4981 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
4982 /* i_block is stored in file system block size */
4983 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
4984 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4985 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4991 * Post the struct inode info into an on-disk inode location in the
4992 * buffer-cache. This gobbles the caller's reference to the
4993 * buffer_head in the inode location struct.
4995 * The caller must have write access to iloc->bh.
4997 static int ext4_do_update_inode(handle_t
*handle
,
4998 struct inode
*inode
,
4999 struct ext4_iloc
*iloc
)
5001 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
5002 struct ext4_inode_info
*ei
= EXT4_I(inode
);
5003 struct buffer_head
*bh
= iloc
->bh
;
5004 int err
= 0, rc
, block
;
5006 /* For fields not not tracking in the in-memory inode,
5007 * initialise them to zero for new inodes. */
5008 if (ei
->i_state
& EXT4_STATE_NEW
)
5009 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
5011 ext4_get_inode_flags(ei
);
5012 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
5013 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5014 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
5015 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
5017 * Fix up interoperability with old kernels. Otherwise, old inodes get
5018 * re-used with the upper 16 bits of the uid/gid intact
5021 raw_inode
->i_uid_high
=
5022 cpu_to_le16(high_16_bits(inode
->i_uid
));
5023 raw_inode
->i_gid_high
=
5024 cpu_to_le16(high_16_bits(inode
->i_gid
));
5026 raw_inode
->i_uid_high
= 0;
5027 raw_inode
->i_gid_high
= 0;
5030 raw_inode
->i_uid_low
=
5031 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
5032 raw_inode
->i_gid_low
=
5033 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
5034 raw_inode
->i_uid_high
= 0;
5035 raw_inode
->i_gid_high
= 0;
5037 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
5039 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
5040 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
5041 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
5042 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
5044 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
5046 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
5047 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
);
5048 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
5049 cpu_to_le32(EXT4_OS_HURD
))
5050 raw_inode
->i_file_acl_high
=
5051 cpu_to_le16(ei
->i_file_acl
>> 32);
5052 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
5053 ext4_isize_set(raw_inode
, ei
->i_disksize
);
5054 if (ei
->i_disksize
> 0x7fffffffULL
) {
5055 struct super_block
*sb
= inode
->i_sb
;
5056 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
5057 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
5058 EXT4_SB(sb
)->s_es
->s_rev_level
==
5059 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
5060 /* If this is the first large file
5061 * created, add a flag to the superblock.
5063 err
= ext4_journal_get_write_access(handle
,
5064 EXT4_SB(sb
)->s_sbh
);
5067 ext4_update_dynamic_rev(sb
);
5068 EXT4_SET_RO_COMPAT_FEATURE(sb
,
5069 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
5071 ext4_handle_sync(handle
);
5072 err
= ext4_handle_dirty_metadata(handle
, inode
,
5073 EXT4_SB(sb
)->s_sbh
);
5076 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
5077 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
5078 if (old_valid_dev(inode
->i_rdev
)) {
5079 raw_inode
->i_block
[0] =
5080 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
5081 raw_inode
->i_block
[1] = 0;
5083 raw_inode
->i_block
[0] = 0;
5084 raw_inode
->i_block
[1] =
5085 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
5086 raw_inode
->i_block
[2] = 0;
5089 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5090 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
5092 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
5093 if (ei
->i_extra_isize
) {
5094 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5095 raw_inode
->i_version_hi
=
5096 cpu_to_le32(inode
->i_version
>> 32);
5097 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
5100 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
5101 rc
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
5104 ei
->i_state
&= ~EXT4_STATE_NEW
;
5106 ext4_update_inode_fsync_trans(handle
, inode
, 0);
5109 ext4_std_error(inode
->i_sb
, err
);
5114 * ext4_write_inode()
5116 * We are called from a few places:
5118 * - Within generic_file_write() for O_SYNC files.
5119 * Here, there will be no transaction running. We wait for any running
5120 * trasnaction to commit.
5122 * - Within sys_sync(), kupdate and such.
5123 * We wait on commit, if tol to.
5125 * - Within prune_icache() (PF_MEMALLOC == true)
5126 * Here we simply return. We can't afford to block kswapd on the
5129 * In all cases it is actually safe for us to return without doing anything,
5130 * because the inode has been copied into a raw inode buffer in
5131 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5134 * Note that we are absolutely dependent upon all inode dirtiers doing the
5135 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5136 * which we are interested.
5138 * It would be a bug for them to not do this. The code:
5140 * mark_inode_dirty(inode)
5142 * inode->i_size = expr;
5144 * is in error because a kswapd-driven write_inode() could occur while
5145 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5146 * will no longer be on the superblock's dirty inode list.
5148 int ext4_write_inode(struct inode
*inode
, int wait
)
5152 if (current
->flags
& PF_MEMALLOC
)
5155 if (EXT4_SB(inode
->i_sb
)->s_journal
) {
5156 if (ext4_journal_current_handle()) {
5157 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5165 err
= ext4_force_commit(inode
->i_sb
);
5167 struct ext4_iloc iloc
;
5169 err
= ext4_get_inode_loc(inode
, &iloc
);
5173 sync_dirty_buffer(iloc
.bh
);
5174 if (buffer_req(iloc
.bh
) && !buffer_uptodate(iloc
.bh
)) {
5175 ext4_error(inode
->i_sb
, __func__
,
5176 "IO error syncing inode, "
5177 "inode=%lu, block=%llu",
5179 (unsigned long long)iloc
.bh
->b_blocknr
);
5189 * Called from notify_change.
5191 * We want to trap VFS attempts to truncate the file as soon as
5192 * possible. In particular, we want to make sure that when the VFS
5193 * shrinks i_size, we put the inode on the orphan list and modify
5194 * i_disksize immediately, so that during the subsequent flushing of
5195 * dirty pages and freeing of disk blocks, we can guarantee that any
5196 * commit will leave the blocks being flushed in an unused state on
5197 * disk. (On recovery, the inode will get truncated and the blocks will
5198 * be freed, so we have a strong guarantee that no future commit will
5199 * leave these blocks visible to the user.)
5201 * Another thing we have to assure is that if we are in ordered mode
5202 * and inode is still attached to the committing transaction, we must
5203 * we start writeout of all the dirty pages which are being truncated.
5204 * This way we are sure that all the data written in the previous
5205 * transaction are already on disk (truncate waits for pages under
5208 * Called with inode->i_mutex down.
5210 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
5212 struct inode
*inode
= dentry
->d_inode
;
5214 const unsigned int ia_valid
= attr
->ia_valid
;
5216 error
= inode_change_ok(inode
, attr
);
5220 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
5221 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
5224 /* (user+group)*(old+new) structure, inode write (sb,
5225 * inode block, ? - but truncate inode update has it) */
5226 handle
= ext4_journal_start(inode
, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode
->i_sb
)+
5227 EXT4_MAXQUOTAS_DEL_BLOCKS(inode
->i_sb
))+3);
5228 if (IS_ERR(handle
)) {
5229 error
= PTR_ERR(handle
);
5232 error
= vfs_dq_transfer(inode
, attr
) ? -EDQUOT
: 0;
5234 ext4_journal_stop(handle
);
5237 /* Update corresponding info in inode so that everything is in
5238 * one transaction */
5239 if (attr
->ia_valid
& ATTR_UID
)
5240 inode
->i_uid
= attr
->ia_uid
;
5241 if (attr
->ia_valid
& ATTR_GID
)
5242 inode
->i_gid
= attr
->ia_gid
;
5243 error
= ext4_mark_inode_dirty(handle
, inode
);
5244 ext4_journal_stop(handle
);
5247 if (attr
->ia_valid
& ATTR_SIZE
) {
5248 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
5249 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5251 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
5258 if (S_ISREG(inode
->i_mode
) &&
5259 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
5262 handle
= ext4_journal_start(inode
, 3);
5263 if (IS_ERR(handle
)) {
5264 error
= PTR_ERR(handle
);
5268 error
= ext4_orphan_add(handle
, inode
);
5269 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
5270 rc
= ext4_mark_inode_dirty(handle
, inode
);
5273 ext4_journal_stop(handle
);
5275 if (ext4_should_order_data(inode
)) {
5276 error
= ext4_begin_ordered_truncate(inode
,
5279 /* Do as much error cleanup as possible */
5280 handle
= ext4_journal_start(inode
, 3);
5281 if (IS_ERR(handle
)) {
5282 ext4_orphan_del(NULL
, inode
);
5285 ext4_orphan_del(handle
, inode
);
5286 ext4_journal_stop(handle
);
5292 rc
= inode_setattr(inode
, attr
);
5294 /* If inode_setattr's call to ext4_truncate failed to get a
5295 * transaction handle at all, we need to clean up the in-core
5296 * orphan list manually. */
5298 ext4_orphan_del(NULL
, inode
);
5300 if (!rc
&& (ia_valid
& ATTR_MODE
))
5301 rc
= ext4_acl_chmod(inode
);
5304 ext4_std_error(inode
->i_sb
, error
);
5310 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
5313 struct inode
*inode
;
5314 unsigned long delalloc_blocks
;
5316 inode
= dentry
->d_inode
;
5317 generic_fillattr(inode
, stat
);
5320 * We can't update i_blocks if the block allocation is delayed
5321 * otherwise in the case of system crash before the real block
5322 * allocation is done, we will have i_blocks inconsistent with
5323 * on-disk file blocks.
5324 * We always keep i_blocks updated together with real
5325 * allocation. But to not confuse with user, stat
5326 * will return the blocks that include the delayed allocation
5327 * blocks for this file.
5329 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
5330 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
5331 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
5333 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
5337 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
5342 /* if nrblocks are contiguous */
5345 * With N contiguous data blocks, it need at most
5346 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5347 * 2 dindirect blocks
5350 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
5351 return indirects
+ 3;
5354 * if nrblocks are not contiguous, worse case, each block touch
5355 * a indirect block, and each indirect block touch a double indirect
5356 * block, plus a triple indirect block
5358 indirects
= nrblocks
* 2 + 1;
5362 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5364 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
5365 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
5366 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
5370 * Account for index blocks, block groups bitmaps and block group
5371 * descriptor blocks if modify datablocks and index blocks
5372 * worse case, the indexs blocks spread over different block groups
5374 * If datablocks are discontiguous, they are possible to spread over
5375 * different block groups too. If they are contiuguous, with flexbg,
5376 * they could still across block group boundary.
5378 * Also account for superblock, inode, quota and xattr blocks
5380 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5382 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
5388 * How many index blocks need to touch to modify nrblocks?
5389 * The "Chunk" flag indicating whether the nrblocks is
5390 * physically contiguous on disk
5392 * For Direct IO and fallocate, they calls get_block to allocate
5393 * one single extent at a time, so they could set the "Chunk" flag
5395 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
5400 * Now let's see how many group bitmaps and group descriptors need
5410 if (groups
> ngroups
)
5412 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
5413 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
5415 /* bitmaps and block group descriptor blocks */
5416 ret
+= groups
+ gdpblocks
;
5418 /* Blocks for super block, inode, quota and xattr blocks */
5419 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
5425 * Calulate the total number of credits to reserve to fit
5426 * the modification of a single pages into a single transaction,
5427 * which may include multiple chunks of block allocations.
5429 * This could be called via ext4_write_begin()
5431 * We need to consider the worse case, when
5432 * one new block per extent.
5434 int ext4_writepage_trans_blocks(struct inode
*inode
)
5436 int bpp
= ext4_journal_blocks_per_page(inode
);
5439 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
5441 /* Account for data blocks for journalled mode */
5442 if (ext4_should_journal_data(inode
))
5448 * Calculate the journal credits for a chunk of data modification.
5450 * This is called from DIO, fallocate or whoever calling
5451 * ext4_get_blocks() to map/allocate a chunk of contiguous disk blocks.
5453 * journal buffers for data blocks are not included here, as DIO
5454 * and fallocate do no need to journal data buffers.
5456 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
5458 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
5462 * The caller must have previously called ext4_reserve_inode_write().
5463 * Give this, we know that the caller already has write access to iloc->bh.
5465 int ext4_mark_iloc_dirty(handle_t
*handle
,
5466 struct inode
*inode
, struct ext4_iloc
*iloc
)
5470 if (test_opt(inode
->i_sb
, I_VERSION
))
5471 inode_inc_iversion(inode
);
5473 /* the do_update_inode consumes one bh->b_count */
5476 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5477 err
= ext4_do_update_inode(handle
, inode
, iloc
);
5483 * On success, We end up with an outstanding reference count against
5484 * iloc->bh. This _must_ be cleaned up later.
5488 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
5489 struct ext4_iloc
*iloc
)
5493 err
= ext4_get_inode_loc(inode
, iloc
);
5495 BUFFER_TRACE(iloc
->bh
, "get_write_access");
5496 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
5502 ext4_std_error(inode
->i_sb
, err
);
5507 * Expand an inode by new_extra_isize bytes.
5508 * Returns 0 on success or negative error number on failure.
5510 static int ext4_expand_extra_isize(struct inode
*inode
,
5511 unsigned int new_extra_isize
,
5512 struct ext4_iloc iloc
,
5515 struct ext4_inode
*raw_inode
;
5516 struct ext4_xattr_ibody_header
*header
;
5517 struct ext4_xattr_entry
*entry
;
5519 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
5522 raw_inode
= ext4_raw_inode(&iloc
);
5524 header
= IHDR(inode
, raw_inode
);
5525 entry
= IFIRST(header
);
5527 /* No extended attributes present */
5528 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
5529 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
5530 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5532 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5536 /* try to expand with EAs present */
5537 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5542 * What we do here is to mark the in-core inode as clean with respect to inode
5543 * dirtiness (it may still be data-dirty).
5544 * This means that the in-core inode may be reaped by prune_icache
5545 * without having to perform any I/O. This is a very good thing,
5546 * because *any* task may call prune_icache - even ones which
5547 * have a transaction open against a different journal.
5549 * Is this cheating? Not really. Sure, we haven't written the
5550 * inode out, but prune_icache isn't a user-visible syncing function.
5551 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5552 * we start and wait on commits.
5554 * Is this efficient/effective? Well, we're being nice to the system
5555 * by cleaning up our inodes proactively so they can be reaped
5556 * without I/O. But we are potentially leaving up to five seconds'
5557 * worth of inodes floating about which prune_icache wants us to
5558 * write out. One way to fix that would be to get prune_icache()
5559 * to do a write_super() to free up some memory. It has the desired
5562 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5564 struct ext4_iloc iloc
;
5565 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5566 static unsigned int mnt_count
;
5570 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5571 if (ext4_handle_valid(handle
) &&
5572 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5573 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
5575 * We need extra buffer credits since we may write into EA block
5576 * with this same handle. If journal_extend fails, then it will
5577 * only result in a minor loss of functionality for that inode.
5578 * If this is felt to be critical, then e2fsck should be run to
5579 * force a large enough s_min_extra_isize.
5581 if ((jbd2_journal_extend(handle
,
5582 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5583 ret
= ext4_expand_extra_isize(inode
,
5584 sbi
->s_want_extra_isize
,
5587 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
5589 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5590 ext4_warning(inode
->i_sb
, __func__
,
5591 "Unable to expand inode %lu. Delete"
5592 " some EAs or run e2fsck.",
5595 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5601 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5606 * ext4_dirty_inode() is called from __mark_inode_dirty()
5608 * We're really interested in the case where a file is being extended.
5609 * i_size has been changed by generic_commit_write() and we thus need
5610 * to include the updated inode in the current transaction.
5612 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
5613 * are allocated to the file.
5615 * If the inode is marked synchronous, we don't honour that here - doing
5616 * so would cause a commit on atime updates, which we don't bother doing.
5617 * We handle synchronous inodes at the highest possible level.
5619 void ext4_dirty_inode(struct inode
*inode
)
5623 handle
= ext4_journal_start(inode
, 2);
5627 ext4_mark_inode_dirty(handle
, inode
);
5629 ext4_journal_stop(handle
);
5636 * Bind an inode's backing buffer_head into this transaction, to prevent
5637 * it from being flushed to disk early. Unlike
5638 * ext4_reserve_inode_write, this leaves behind no bh reference and
5639 * returns no iloc structure, so the caller needs to repeat the iloc
5640 * lookup to mark the inode dirty later.
5642 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5644 struct ext4_iloc iloc
;
5648 err
= ext4_get_inode_loc(inode
, &iloc
);
5650 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5651 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5653 err
= ext4_handle_dirty_metadata(handle
,
5659 ext4_std_error(inode
->i_sb
, err
);
5664 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5671 * We have to be very careful here: changing a data block's
5672 * journaling status dynamically is dangerous. If we write a
5673 * data block to the journal, change the status and then delete
5674 * that block, we risk forgetting to revoke the old log record
5675 * from the journal and so a subsequent replay can corrupt data.
5676 * So, first we make sure that the journal is empty and that
5677 * nobody is changing anything.
5680 journal
= EXT4_JOURNAL(inode
);
5683 if (is_journal_aborted(journal
))
5686 jbd2_journal_lock_updates(journal
);
5687 jbd2_journal_flush(journal
);
5690 * OK, there are no updates running now, and all cached data is
5691 * synced to disk. We are now in a completely consistent state
5692 * which doesn't have anything in the journal, and we know that
5693 * no filesystem updates are running, so it is safe to modify
5694 * the inode's in-core data-journaling state flag now.
5698 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
5700 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
5701 ext4_set_aops(inode
);
5703 jbd2_journal_unlock_updates(journal
);
5705 /* Finally we can mark the inode as dirty. */
5707 handle
= ext4_journal_start(inode
, 1);
5709 return PTR_ERR(handle
);
5711 err
= ext4_mark_inode_dirty(handle
, inode
);
5712 ext4_handle_sync(handle
);
5713 ext4_journal_stop(handle
);
5714 ext4_std_error(inode
->i_sb
, err
);
5719 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5721 return !buffer_mapped(bh
);
5724 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5726 struct page
*page
= vmf
->page
;
5731 struct file
*file
= vma
->vm_file
;
5732 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5733 struct address_space
*mapping
= inode
->i_mapping
;
5736 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5737 * get i_mutex because we are already holding mmap_sem.
5739 down_read(&inode
->i_alloc_sem
);
5740 size
= i_size_read(inode
);
5741 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5742 || !PageUptodate(page
)) {
5743 /* page got truncated from under us? */
5747 if (PageMappedToDisk(page
))
5750 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5751 len
= size
& ~PAGE_CACHE_MASK
;
5753 len
= PAGE_CACHE_SIZE
;
5757 * return if we have all the buffers mapped. This avoid
5758 * the need to call write_begin/write_end which does a
5759 * journal_start/journal_stop which can block and take
5762 if (page_has_buffers(page
)) {
5763 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5764 ext4_bh_unmapped
)) {
5771 * OK, we need to fill the hole... Do write_begin write_end
5772 * to do block allocation/reservation.We are not holding
5773 * inode.i__mutex here. That allow * parallel write_begin,
5774 * write_end call. lock_page prevent this from happening
5775 * on the same page though
5777 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5778 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5781 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5782 len
, len
, page
, fsdata
);
5788 ret
= VM_FAULT_SIGBUS
;
5789 up_read(&inode
->i_alloc_sem
);