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
);
1046 static void ext4_da_update_reserve_space(struct inode
*inode
, int used
)
1048 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1049 int total
, mdb
, mdb_free
, mdb_claim
= 0;
1051 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1052 /* recalculate the number of metablocks still need to be reserved */
1053 total
= EXT4_I(inode
)->i_reserved_data_blocks
- used
;
1054 mdb
= ext4_calc_metadata_amount(inode
, total
);
1056 /* figure out how many metablocks to release */
1057 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1058 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1061 /* Account for allocated meta_blocks */
1062 mdb_claim
= EXT4_I(inode
)->i_allocated_meta_blocks
;
1063 BUG_ON(mdb_free
< mdb_claim
);
1064 mdb_free
-= mdb_claim
;
1066 /* update fs dirty blocks counter */
1067 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1068 EXT4_I(inode
)->i_allocated_meta_blocks
= 0;
1069 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1072 /* update per-inode reservations */
1073 BUG_ON(used
> EXT4_I(inode
)->i_reserved_data_blocks
);
1074 EXT4_I(inode
)->i_reserved_data_blocks
-= used
;
1075 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, used
+ mdb_claim
);
1076 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1078 vfs_dq_claim_block(inode
, used
+ mdb_claim
);
1081 * free those over-booking quota for metadata blocks
1084 vfs_dq_release_reservation_block(inode
, mdb_free
);
1087 * If we have done all the pending block allocations and if
1088 * there aren't any writers on the inode, we can discard the
1089 * inode's preallocations.
1091 if (!total
&& (atomic_read(&inode
->i_writecount
) == 0))
1092 ext4_discard_preallocations(inode
);
1095 static int check_block_validity(struct inode
*inode
, const char *msg
,
1096 sector_t logical
, sector_t phys
, int len
)
1098 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), phys
, len
)) {
1099 ext4_error(inode
->i_sb
, msg
,
1100 "inode #%lu logical block %llu mapped to %llu "
1101 "(size %d)", inode
->i_ino
,
1102 (unsigned long long) logical
,
1103 (unsigned long long) phys
, len
);
1110 * Return the number of contiguous dirty pages in a given inode
1111 * starting at page frame idx.
1113 static pgoff_t
ext4_num_dirty_pages(struct inode
*inode
, pgoff_t idx
,
1114 unsigned int max_pages
)
1116 struct address_space
*mapping
= inode
->i_mapping
;
1118 struct pagevec pvec
;
1120 int i
, nr_pages
, done
= 0;
1124 pagevec_init(&pvec
, 0);
1127 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1128 PAGECACHE_TAG_DIRTY
,
1129 (pgoff_t
)PAGEVEC_SIZE
);
1132 for (i
= 0; i
< nr_pages
; i
++) {
1133 struct page
*page
= pvec
.pages
[i
];
1134 struct buffer_head
*bh
, *head
;
1137 if (unlikely(page
->mapping
!= mapping
) ||
1139 PageWriteback(page
) ||
1140 page
->index
!= idx
) {
1145 if (page_has_buffers(page
)) {
1146 bh
= head
= page_buffers(page
);
1148 if (!buffer_delay(bh
) &&
1149 !buffer_unwritten(bh
))
1151 bh
= bh
->b_this_page
;
1152 } while (!done
&& (bh
!= head
));
1159 if (num
>= max_pages
)
1162 pagevec_release(&pvec
);
1168 * The ext4_get_blocks() function tries to look up the requested blocks,
1169 * and returns if the blocks are already mapped.
1171 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1172 * and store the allocated blocks in the result buffer head and mark it
1175 * If file type is extents based, it will call ext4_ext_get_blocks(),
1176 * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
1179 * On success, it returns the number of blocks being mapped or allocate.
1180 * if create==0 and the blocks are pre-allocated and uninitialized block,
1181 * the result buffer head is unmapped. If the create ==1, it will make sure
1182 * the buffer head is mapped.
1184 * It returns 0 if plain look up failed (blocks have not been allocated), in
1185 * that casem, buffer head is unmapped
1187 * It returns the error in case of allocation failure.
1189 int ext4_get_blocks(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1190 unsigned int max_blocks
, struct buffer_head
*bh
,
1195 clear_buffer_mapped(bh
);
1196 clear_buffer_unwritten(bh
);
1198 ext_debug("ext4_get_blocks(): inode %lu, flag %d, max_blocks %u,"
1199 "logical block %lu\n", inode
->i_ino
, flags
, max_blocks
,
1200 (unsigned long)block
);
1202 * Try to see if we can get the block without requesting a new
1203 * file system block.
1205 down_read((&EXT4_I(inode
)->i_data_sem
));
1206 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1207 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1210 retval
= ext4_ind_get_blocks(handle
, inode
, block
, max_blocks
,
1213 up_read((&EXT4_I(inode
)->i_data_sem
));
1215 if (retval
> 0 && buffer_mapped(bh
)) {
1216 int ret
= check_block_validity(inode
, "file system corruption",
1217 block
, bh
->b_blocknr
, retval
);
1222 /* If it is only a block(s) look up */
1223 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
1227 * Returns if the blocks have already allocated
1229 * Note that if blocks have been preallocated
1230 * ext4_ext_get_block() returns th create = 0
1231 * with buffer head unmapped.
1233 if (retval
> 0 && buffer_mapped(bh
))
1237 * When we call get_blocks without the create flag, the
1238 * BH_Unwritten flag could have gotten set if the blocks
1239 * requested were part of a uninitialized extent. We need to
1240 * clear this flag now that we are committed to convert all or
1241 * part of the uninitialized extent to be an initialized
1242 * extent. This is because we need to avoid the combination
1243 * of BH_Unwritten and BH_Mapped flags being simultaneously
1244 * set on the buffer_head.
1246 clear_buffer_unwritten(bh
);
1249 * New blocks allocate and/or writing to uninitialized extent
1250 * will possibly result in updating i_data, so we take
1251 * the write lock of i_data_sem, and call get_blocks()
1252 * with create == 1 flag.
1254 down_write((&EXT4_I(inode
)->i_data_sem
));
1257 * if the caller is from delayed allocation writeout path
1258 * we have already reserved fs blocks for allocation
1259 * let the underlying get_block() function know to
1260 * avoid double accounting
1262 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1263 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1265 * We need to check for EXT4 here because migrate
1266 * could have changed the inode type in between
1268 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1269 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1272 retval
= ext4_ind_get_blocks(handle
, inode
, block
,
1273 max_blocks
, bh
, flags
);
1275 if (retval
> 0 && buffer_new(bh
)) {
1277 * We allocated new blocks which will result in
1278 * i_data's format changing. Force the migrate
1279 * to fail by clearing migrate flags
1281 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_EXT_MIGRATE
;
1285 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1286 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1289 * Update reserved blocks/metadata blocks after successful
1290 * block allocation which had been deferred till now.
1292 if ((retval
> 0) && (flags
& EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
))
1293 ext4_da_update_reserve_space(inode
, retval
);
1295 up_write((&EXT4_I(inode
)->i_data_sem
));
1296 if (retval
> 0 && buffer_mapped(bh
)) {
1297 int ret
= check_block_validity(inode
, "file system "
1298 "corruption after allocation",
1299 block
, bh
->b_blocknr
, retval
);
1306 /* Maximum number of blocks we map for direct IO at once. */
1307 #define DIO_MAX_BLOCKS 4096
1309 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1310 struct buffer_head
*bh_result
, int create
)
1312 handle_t
*handle
= ext4_journal_current_handle();
1313 int ret
= 0, started
= 0;
1314 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1317 if (create
&& !handle
) {
1318 /* Direct IO write... */
1319 if (max_blocks
> DIO_MAX_BLOCKS
)
1320 max_blocks
= DIO_MAX_BLOCKS
;
1321 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1322 handle
= ext4_journal_start(inode
, dio_credits
);
1323 if (IS_ERR(handle
)) {
1324 ret
= PTR_ERR(handle
);
1330 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
1331 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1333 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1337 ext4_journal_stop(handle
);
1343 * `handle' can be NULL if create is zero
1345 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1346 ext4_lblk_t block
, int create
, int *errp
)
1348 struct buffer_head dummy
;
1352 J_ASSERT(handle
!= NULL
|| create
== 0);
1355 dummy
.b_blocknr
= -1000;
1356 buffer_trace_init(&dummy
.b_history
);
1358 flags
|= EXT4_GET_BLOCKS_CREATE
;
1359 err
= ext4_get_blocks(handle
, inode
, block
, 1, &dummy
, flags
);
1361 * ext4_get_blocks() returns number of blocks mapped. 0 in
1370 if (!err
&& buffer_mapped(&dummy
)) {
1371 struct buffer_head
*bh
;
1372 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1377 if (buffer_new(&dummy
)) {
1378 J_ASSERT(create
!= 0);
1379 J_ASSERT(handle
!= NULL
);
1382 * Now that we do not always journal data, we should
1383 * keep in mind whether this should always journal the
1384 * new buffer as metadata. For now, regular file
1385 * writes use ext4_get_block instead, so it's not a
1389 BUFFER_TRACE(bh
, "call get_create_access");
1390 fatal
= ext4_journal_get_create_access(handle
, bh
);
1391 if (!fatal
&& !buffer_uptodate(bh
)) {
1392 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1393 set_buffer_uptodate(bh
);
1396 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1397 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1401 BUFFER_TRACE(bh
, "not a new buffer");
1414 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1415 ext4_lblk_t block
, int create
, int *err
)
1417 struct buffer_head
*bh
;
1419 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1422 if (buffer_uptodate(bh
))
1424 ll_rw_block(READ_META
, 1, &bh
);
1426 if (buffer_uptodate(bh
))
1433 static int walk_page_buffers(handle_t
*handle
,
1434 struct buffer_head
*head
,
1438 int (*fn
)(handle_t
*handle
,
1439 struct buffer_head
*bh
))
1441 struct buffer_head
*bh
;
1442 unsigned block_start
, block_end
;
1443 unsigned blocksize
= head
->b_size
;
1445 struct buffer_head
*next
;
1447 for (bh
= head
, block_start
= 0;
1448 ret
== 0 && (bh
!= head
|| !block_start
);
1449 block_start
= block_end
, bh
= next
) {
1450 next
= bh
->b_this_page
;
1451 block_end
= block_start
+ blocksize
;
1452 if (block_end
<= from
|| block_start
>= to
) {
1453 if (partial
&& !buffer_uptodate(bh
))
1457 err
= (*fn
)(handle
, bh
);
1465 * To preserve ordering, it is essential that the hole instantiation and
1466 * the data write be encapsulated in a single transaction. We cannot
1467 * close off a transaction and start a new one between the ext4_get_block()
1468 * and the commit_write(). So doing the jbd2_journal_start at the start of
1469 * prepare_write() is the right place.
1471 * Also, this function can nest inside ext4_writepage() ->
1472 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1473 * has generated enough buffer credits to do the whole page. So we won't
1474 * block on the journal in that case, which is good, because the caller may
1477 * By accident, ext4 can be reentered when a transaction is open via
1478 * quota file writes. If we were to commit the transaction while thus
1479 * reentered, there can be a deadlock - we would be holding a quota
1480 * lock, and the commit would never complete if another thread had a
1481 * transaction open and was blocking on the quota lock - a ranking
1484 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1485 * will _not_ run commit under these circumstances because handle->h_ref
1486 * is elevated. We'll still have enough credits for the tiny quotafile
1489 static int do_journal_get_write_access(handle_t
*handle
,
1490 struct buffer_head
*bh
)
1492 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1494 return ext4_journal_get_write_access(handle
, bh
);
1498 * Truncate blocks that were not used by write. We have to truncate the
1499 * pagecache as well so that corresponding buffers get properly unmapped.
1501 static void ext4_truncate_failed_write(struct inode
*inode
)
1503 truncate_inode_pages(inode
->i_mapping
, inode
->i_size
);
1504 ext4_truncate(inode
);
1507 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1508 loff_t pos
, unsigned len
, unsigned flags
,
1509 struct page
**pagep
, void **fsdata
)
1511 struct inode
*inode
= mapping
->host
;
1512 int ret
, needed_blocks
;
1519 trace_ext4_write_begin(inode
, pos
, len
, flags
);
1521 * Reserve one block more for addition to orphan list in case
1522 * we allocate blocks but write fails for some reason
1524 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
1525 index
= pos
>> PAGE_CACHE_SHIFT
;
1526 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1530 handle
= ext4_journal_start(inode
, needed_blocks
);
1531 if (IS_ERR(handle
)) {
1532 ret
= PTR_ERR(handle
);
1536 /* We cannot recurse into the filesystem as the transaction is already
1538 flags
|= AOP_FLAG_NOFS
;
1540 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1542 ext4_journal_stop(handle
);
1548 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1551 if (!ret
&& ext4_should_journal_data(inode
)) {
1552 ret
= walk_page_buffers(handle
, page_buffers(page
),
1553 from
, to
, NULL
, do_journal_get_write_access
);
1558 page_cache_release(page
);
1560 * block_write_begin may have instantiated a few blocks
1561 * outside i_size. Trim these off again. Don't need
1562 * i_size_read because we hold i_mutex.
1564 * Add inode to orphan list in case we crash before
1567 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1568 ext4_orphan_add(handle
, inode
);
1570 ext4_journal_stop(handle
);
1571 if (pos
+ len
> inode
->i_size
) {
1572 ext4_truncate_failed_write(inode
);
1574 * If truncate failed early the inode might
1575 * still be on the orphan list; we need to
1576 * make sure the inode is removed from the
1577 * orphan list in that case.
1580 ext4_orphan_del(NULL
, inode
);
1584 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1590 /* For write_end() in data=journal mode */
1591 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1593 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1595 set_buffer_uptodate(bh
);
1596 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1599 static int ext4_generic_write_end(struct file
*file
,
1600 struct address_space
*mapping
,
1601 loff_t pos
, unsigned len
, unsigned copied
,
1602 struct page
*page
, void *fsdata
)
1604 int i_size_changed
= 0;
1605 struct inode
*inode
= mapping
->host
;
1606 handle_t
*handle
= ext4_journal_current_handle();
1608 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1611 * No need to use i_size_read() here, the i_size
1612 * cannot change under us because we hold i_mutex.
1614 * But it's important to update i_size while still holding page lock:
1615 * page writeout could otherwise come in and zero beyond i_size.
1617 if (pos
+ copied
> inode
->i_size
) {
1618 i_size_write(inode
, pos
+ copied
);
1622 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
1623 /* We need to mark inode dirty even if
1624 * new_i_size is less that inode->i_size
1625 * bu greater than i_disksize.(hint delalloc)
1627 ext4_update_i_disksize(inode
, (pos
+ copied
));
1631 page_cache_release(page
);
1634 * Don't mark the inode dirty under page lock. First, it unnecessarily
1635 * makes the holding time of page lock longer. Second, it forces lock
1636 * ordering of page lock and transaction start for journaling
1640 ext4_mark_inode_dirty(handle
, inode
);
1646 * We need to pick up the new inode size which generic_commit_write gave us
1647 * `file' can be NULL - eg, when called from page_symlink().
1649 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1650 * buffers are managed internally.
1652 static int ext4_ordered_write_end(struct file
*file
,
1653 struct address_space
*mapping
,
1654 loff_t pos
, unsigned len
, unsigned copied
,
1655 struct page
*page
, void *fsdata
)
1657 handle_t
*handle
= ext4_journal_current_handle();
1658 struct inode
*inode
= mapping
->host
;
1661 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
1662 ret
= ext4_jbd2_file_inode(handle
, inode
);
1665 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1668 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1669 /* if we have allocated more blocks and copied
1670 * less. We will have blocks allocated outside
1671 * inode->i_size. So truncate them
1673 ext4_orphan_add(handle
, inode
);
1677 ret2
= ext4_journal_stop(handle
);
1681 if (pos
+ len
> inode
->i_size
) {
1682 ext4_truncate_failed_write(inode
);
1684 * If truncate failed early the inode might still be
1685 * on the orphan list; we need to make sure the inode
1686 * is removed from the orphan list in that case.
1689 ext4_orphan_del(NULL
, inode
);
1693 return ret
? ret
: copied
;
1696 static int ext4_writeback_write_end(struct file
*file
,
1697 struct address_space
*mapping
,
1698 loff_t pos
, unsigned len
, unsigned copied
,
1699 struct page
*page
, void *fsdata
)
1701 handle_t
*handle
= ext4_journal_current_handle();
1702 struct inode
*inode
= mapping
->host
;
1705 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1706 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1709 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1710 /* if we have allocated more blocks and copied
1711 * less. We will have blocks allocated outside
1712 * inode->i_size. So truncate them
1714 ext4_orphan_add(handle
, inode
);
1719 ret2
= ext4_journal_stop(handle
);
1723 if (pos
+ len
> inode
->i_size
) {
1724 ext4_truncate_failed_write(inode
);
1726 * If truncate failed early the inode might still be
1727 * on the orphan list; we need to make sure the inode
1728 * is removed from the orphan list in that case.
1731 ext4_orphan_del(NULL
, inode
);
1734 return ret
? ret
: copied
;
1737 static int ext4_journalled_write_end(struct file
*file
,
1738 struct address_space
*mapping
,
1739 loff_t pos
, unsigned len
, unsigned copied
,
1740 struct page
*page
, void *fsdata
)
1742 handle_t
*handle
= ext4_journal_current_handle();
1743 struct inode
*inode
= mapping
->host
;
1749 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1750 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1754 if (!PageUptodate(page
))
1756 page_zero_new_buffers(page
, from
+copied
, to
);
1759 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1760 to
, &partial
, write_end_fn
);
1762 SetPageUptodate(page
);
1763 new_i_size
= pos
+ copied
;
1764 if (new_i_size
> inode
->i_size
)
1765 i_size_write(inode
, pos
+copied
);
1766 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1767 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1768 ext4_update_i_disksize(inode
, new_i_size
);
1769 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1775 page_cache_release(page
);
1776 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1777 /* if we have allocated more blocks and copied
1778 * less. We will have blocks allocated outside
1779 * inode->i_size. So truncate them
1781 ext4_orphan_add(handle
, inode
);
1783 ret2
= ext4_journal_stop(handle
);
1786 if (pos
+ len
> inode
->i_size
) {
1787 ext4_truncate_failed_write(inode
);
1789 * If truncate failed early the inode might still be
1790 * on the orphan list; we need to make sure the inode
1791 * is removed from the orphan list in that case.
1794 ext4_orphan_del(NULL
, inode
);
1797 return ret
? ret
: copied
;
1800 static int ext4_da_reserve_space(struct inode
*inode
, int nrblocks
)
1803 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1804 unsigned long md_needed
, mdblocks
, total
= 0;
1807 * recalculate the amount of metadata blocks to reserve
1808 * in order to allocate nrblocks
1809 * worse case is one extent per block
1812 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1813 total
= EXT4_I(inode
)->i_reserved_data_blocks
+ nrblocks
;
1814 mdblocks
= ext4_calc_metadata_amount(inode
, total
);
1815 BUG_ON(mdblocks
< EXT4_I(inode
)->i_reserved_meta_blocks
);
1817 md_needed
= mdblocks
- EXT4_I(inode
)->i_reserved_meta_blocks
;
1818 total
= md_needed
+ nrblocks
;
1819 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1822 * Make quota reservation here to prevent quota overflow
1823 * later. Real quota accounting is done at pages writeout
1826 if (vfs_dq_reserve_block(inode
, total
))
1829 if (ext4_claim_free_blocks(sbi
, total
)) {
1830 vfs_dq_release_reservation_block(inode
, total
);
1831 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1837 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1838 EXT4_I(inode
)->i_reserved_data_blocks
+= nrblocks
;
1839 EXT4_I(inode
)->i_reserved_meta_blocks
+= md_needed
;
1840 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1842 return 0; /* success */
1845 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1847 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1848 int total
, mdb
, mdb_free
, release
;
1851 return; /* Nothing to release, exit */
1853 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1855 if (!EXT4_I(inode
)->i_reserved_data_blocks
) {
1857 * if there is no reserved blocks, but we try to free some
1858 * then the counter is messed up somewhere.
1859 * but since this function is called from invalidate
1860 * page, it's harmless to return without any action
1862 printk(KERN_INFO
"ext4 delalloc try to release %d reserved "
1863 "blocks for inode %lu, but there is no reserved "
1864 "data blocks\n", to_free
, inode
->i_ino
);
1865 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1869 /* recalculate the number of metablocks still need to be reserved */
1870 total
= EXT4_I(inode
)->i_reserved_data_blocks
- to_free
;
1871 mdb
= ext4_calc_metadata_amount(inode
, total
);
1873 /* figure out how many metablocks to release */
1874 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1875 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1877 release
= to_free
+ mdb_free
;
1879 /* update fs dirty blocks counter for truncate case */
1880 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, release
);
1882 /* update per-inode reservations */
1883 BUG_ON(to_free
> EXT4_I(inode
)->i_reserved_data_blocks
);
1884 EXT4_I(inode
)->i_reserved_data_blocks
-= to_free
;
1886 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1887 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1888 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1890 vfs_dq_release_reservation_block(inode
, release
);
1893 static void ext4_da_page_release_reservation(struct page
*page
,
1894 unsigned long offset
)
1897 struct buffer_head
*head
, *bh
;
1898 unsigned int curr_off
= 0;
1900 head
= page_buffers(page
);
1903 unsigned int next_off
= curr_off
+ bh
->b_size
;
1905 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1907 clear_buffer_delay(bh
);
1909 curr_off
= next_off
;
1910 } while ((bh
= bh
->b_this_page
) != head
);
1911 ext4_da_release_space(page
->mapping
->host
, to_release
);
1915 * Delayed allocation stuff
1919 * mpage_da_submit_io - walks through extent of pages and try to write
1920 * them with writepage() call back
1922 * @mpd->inode: inode
1923 * @mpd->first_page: first page of the extent
1924 * @mpd->next_page: page after the last page of the extent
1926 * By the time mpage_da_submit_io() is called we expect all blocks
1927 * to be allocated. this may be wrong if allocation failed.
1929 * As pages are already locked by write_cache_pages(), we can't use it
1931 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1934 struct pagevec pvec
;
1935 unsigned long index
, end
;
1936 int ret
= 0, err
, nr_pages
, i
;
1937 struct inode
*inode
= mpd
->inode
;
1938 struct address_space
*mapping
= inode
->i_mapping
;
1940 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1942 * We need to start from the first_page to the next_page - 1
1943 * to make sure we also write the mapped dirty buffer_heads.
1944 * If we look at mpd->b_blocknr we would only be looking
1945 * at the currently mapped buffer_heads.
1947 index
= mpd
->first_page
;
1948 end
= mpd
->next_page
- 1;
1950 pagevec_init(&pvec
, 0);
1951 while (index
<= end
) {
1952 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1955 for (i
= 0; i
< nr_pages
; i
++) {
1956 struct page
*page
= pvec
.pages
[i
];
1958 index
= page
->index
;
1963 BUG_ON(!PageLocked(page
));
1964 BUG_ON(PageWriteback(page
));
1966 pages_skipped
= mpd
->wbc
->pages_skipped
;
1967 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
1968 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
1970 * have successfully written the page
1971 * without skipping the same
1973 mpd
->pages_written
++;
1975 * In error case, we have to continue because
1976 * remaining pages are still locked
1977 * XXX: unlock and re-dirty them?
1982 pagevec_release(&pvec
);
1988 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
1990 * @mpd->inode - inode to walk through
1991 * @exbh->b_blocknr - first block on a disk
1992 * @exbh->b_size - amount of space in bytes
1993 * @logical - first logical block to start assignment with
1995 * the function goes through all passed space and put actual disk
1996 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
1998 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
1999 struct buffer_head
*exbh
)
2001 struct inode
*inode
= mpd
->inode
;
2002 struct address_space
*mapping
= inode
->i_mapping
;
2003 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
2004 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
2005 struct buffer_head
*head
, *bh
;
2007 struct pagevec pvec
;
2010 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2011 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2012 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2014 pagevec_init(&pvec
, 0);
2016 while (index
<= end
) {
2017 /* XXX: optimize tail */
2018 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2021 for (i
= 0; i
< nr_pages
; i
++) {
2022 struct page
*page
= pvec
.pages
[i
];
2024 index
= page
->index
;
2029 BUG_ON(!PageLocked(page
));
2030 BUG_ON(PageWriteback(page
));
2031 BUG_ON(!page_has_buffers(page
));
2033 bh
= page_buffers(page
);
2036 /* skip blocks out of the range */
2038 if (cur_logical
>= logical
)
2041 } while ((bh
= bh
->b_this_page
) != head
);
2044 if (cur_logical
>= logical
+ blocks
)
2047 if (buffer_delay(bh
) ||
2048 buffer_unwritten(bh
)) {
2050 BUG_ON(bh
->b_bdev
!= inode
->i_sb
->s_bdev
);
2052 if (buffer_delay(bh
)) {
2053 clear_buffer_delay(bh
);
2054 bh
->b_blocknr
= pblock
;
2057 * unwritten already should have
2058 * blocknr assigned. Verify that
2060 clear_buffer_unwritten(bh
);
2061 BUG_ON(bh
->b_blocknr
!= pblock
);
2064 } else if (buffer_mapped(bh
))
2065 BUG_ON(bh
->b_blocknr
!= pblock
);
2069 } while ((bh
= bh
->b_this_page
) != head
);
2071 pagevec_release(&pvec
);
2077 * __unmap_underlying_blocks - just a helper function to unmap
2078 * set of blocks described by @bh
2080 static inline void __unmap_underlying_blocks(struct inode
*inode
,
2081 struct buffer_head
*bh
)
2083 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
2086 blocks
= bh
->b_size
>> inode
->i_blkbits
;
2087 for (i
= 0; i
< blocks
; i
++)
2088 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
2091 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
2092 sector_t logical
, long blk_cnt
)
2096 struct pagevec pvec
;
2097 struct inode
*inode
= mpd
->inode
;
2098 struct address_space
*mapping
= inode
->i_mapping
;
2100 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2101 end
= (logical
+ blk_cnt
- 1) >>
2102 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2103 while (index
<= end
) {
2104 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2107 for (i
= 0; i
< nr_pages
; i
++) {
2108 struct page
*page
= pvec
.pages
[i
];
2109 index
= page
->index
;
2114 BUG_ON(!PageLocked(page
));
2115 BUG_ON(PageWriteback(page
));
2116 block_invalidatepage(page
, 0);
2117 ClearPageUptodate(page
);
2124 static void ext4_print_free_blocks(struct inode
*inode
)
2126 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2127 printk(KERN_CRIT
"Total free blocks count %lld\n",
2128 ext4_count_free_blocks(inode
->i_sb
));
2129 printk(KERN_CRIT
"Free/Dirty block details\n");
2130 printk(KERN_CRIT
"free_blocks=%lld\n",
2131 (long long) percpu_counter_sum(&sbi
->s_freeblocks_counter
));
2132 printk(KERN_CRIT
"dirty_blocks=%lld\n",
2133 (long long) percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
2134 printk(KERN_CRIT
"Block reservation details\n");
2135 printk(KERN_CRIT
"i_reserved_data_blocks=%u\n",
2136 EXT4_I(inode
)->i_reserved_data_blocks
);
2137 printk(KERN_CRIT
"i_reserved_meta_blocks=%u\n",
2138 EXT4_I(inode
)->i_reserved_meta_blocks
);
2143 * mpage_da_map_blocks - go through given space
2145 * @mpd - bh describing space
2147 * The function skips space we know is already mapped to disk blocks.
2150 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
2152 int err
, blks
, get_blocks_flags
;
2153 struct buffer_head
new;
2154 sector_t next
= mpd
->b_blocknr
;
2155 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2156 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
2157 handle_t
*handle
= NULL
;
2160 * We consider only non-mapped and non-allocated blocks
2162 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2163 !(mpd
->b_state
& (1 << BH_Delay
)) &&
2164 !(mpd
->b_state
& (1 << BH_Unwritten
)))
2168 * If we didn't accumulate anything to write simply return
2173 handle
= ext4_journal_current_handle();
2177 * Call ext4_get_blocks() to allocate any delayed allocation
2178 * blocks, or to convert an uninitialized extent to be
2179 * initialized (in the case where we have written into
2180 * one or more preallocated blocks).
2182 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2183 * indicate that we are on the delayed allocation path. This
2184 * affects functions in many different parts of the allocation
2185 * call path. This flag exists primarily because we don't
2186 * want to change *many* call functions, so ext4_get_blocks()
2187 * will set the magic i_delalloc_reserved_flag once the
2188 * inode's allocation semaphore is taken.
2190 * If the blocks in questions were delalloc blocks, set
2191 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2192 * variables are updated after the blocks have been allocated.
2195 get_blocks_flags
= (EXT4_GET_BLOCKS_CREATE
|
2196 EXT4_GET_BLOCKS_DELALLOC_RESERVE
);
2197 if (mpd
->b_state
& (1 << BH_Delay
))
2198 get_blocks_flags
|= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
;
2199 blks
= ext4_get_blocks(handle
, mpd
->inode
, next
, max_blocks
,
2200 &new, get_blocks_flags
);
2204 * If get block returns with error we simply
2205 * return. Later writepage will redirty the page and
2206 * writepages will find the dirty page again
2211 if (err
== -ENOSPC
&&
2212 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
2218 * get block failure will cause us to loop in
2219 * writepages, because a_ops->writepage won't be able
2220 * to make progress. The page will be redirtied by
2221 * writepage and writepages will again try to write
2224 ext4_msg(mpd
->inode
->i_sb
, KERN_CRIT
,
2225 "delayed block allocation failed for inode %lu at "
2226 "logical offset %llu with max blocks %zd with "
2227 "error %d\n", mpd
->inode
->i_ino
,
2228 (unsigned long long) next
,
2229 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2230 printk(KERN_CRIT
"This should not happen!! "
2231 "Data will be lost\n");
2232 if (err
== -ENOSPC
) {
2233 ext4_print_free_blocks(mpd
->inode
);
2235 /* invalidate all the pages */
2236 ext4_da_block_invalidatepages(mpd
, next
,
2237 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2242 new.b_size
= (blks
<< mpd
->inode
->i_blkbits
);
2244 if (buffer_new(&new))
2245 __unmap_underlying_blocks(mpd
->inode
, &new);
2248 * If blocks are delayed marked, we need to
2249 * put actual blocknr and drop delayed bit
2251 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2252 (mpd
->b_state
& (1 << BH_Unwritten
)))
2253 mpage_put_bnr_to_bhs(mpd
, next
, &new);
2255 if (ext4_should_order_data(mpd
->inode
)) {
2256 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
2262 * Update on-disk size along with block allocation.
2264 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
2265 if (disksize
> i_size_read(mpd
->inode
))
2266 disksize
= i_size_read(mpd
->inode
);
2267 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
2268 ext4_update_i_disksize(mpd
->inode
, disksize
);
2269 return ext4_mark_inode_dirty(handle
, mpd
->inode
);
2275 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2276 (1 << BH_Delay) | (1 << BH_Unwritten))
2279 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2281 * @mpd->lbh - extent of blocks
2282 * @logical - logical number of the block in the file
2283 * @bh - bh of the block (used to access block's state)
2285 * the function is used to collect contig. blocks in same state
2287 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2288 sector_t logical
, size_t b_size
,
2289 unsigned long b_state
)
2292 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2294 /* check if thereserved journal credits might overflow */
2295 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
2296 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2298 * With non-extent format we are limited by the journal
2299 * credit available. Total credit needed to insert
2300 * nrblocks contiguous blocks is dependent on the
2301 * nrblocks. So limit nrblocks.
2304 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2305 EXT4_MAX_TRANS_DATA
) {
2307 * Adding the new buffer_head would make it cross the
2308 * allowed limit for which we have journal credit
2309 * reserved. So limit the new bh->b_size
2311 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2312 mpd
->inode
->i_blkbits
;
2313 /* we will do mpage_da_submit_io in the next loop */
2317 * First block in the extent
2319 if (mpd
->b_size
== 0) {
2320 mpd
->b_blocknr
= logical
;
2321 mpd
->b_size
= b_size
;
2322 mpd
->b_state
= b_state
& BH_FLAGS
;
2326 next
= mpd
->b_blocknr
+ nrblocks
;
2328 * Can we merge the block to our big extent?
2330 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2331 mpd
->b_size
+= b_size
;
2337 * We couldn't merge the block to our extent, so we
2338 * need to flush current extent and start new one
2340 if (mpage_da_map_blocks(mpd
) == 0)
2341 mpage_da_submit_io(mpd
);
2346 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
)
2348 return (buffer_delay(bh
) || buffer_unwritten(bh
)) && buffer_dirty(bh
);
2352 * __mpage_da_writepage - finds extent of pages and blocks
2354 * @page: page to consider
2355 * @wbc: not used, we just follow rules
2358 * The function finds extents of pages and scan them for all blocks.
2360 static int __mpage_da_writepage(struct page
*page
,
2361 struct writeback_control
*wbc
, void *data
)
2363 struct mpage_da_data
*mpd
= data
;
2364 struct inode
*inode
= mpd
->inode
;
2365 struct buffer_head
*bh
, *head
;
2370 * Rest of the page in the page_vec
2371 * redirty then and skip then. We will
2372 * try to write them again after
2373 * starting a new transaction
2375 redirty_page_for_writepage(wbc
, page
);
2377 return MPAGE_DA_EXTENT_TAIL
;
2380 * Can we merge this page to current extent?
2382 if (mpd
->next_page
!= page
->index
) {
2384 * Nope, we can't. So, we map non-allocated blocks
2385 * and start IO on them using writepage()
2387 if (mpd
->next_page
!= mpd
->first_page
) {
2388 if (mpage_da_map_blocks(mpd
) == 0)
2389 mpage_da_submit_io(mpd
);
2391 * skip rest of the page in the page_vec
2394 redirty_page_for_writepage(wbc
, page
);
2396 return MPAGE_DA_EXTENT_TAIL
;
2400 * Start next extent of pages ...
2402 mpd
->first_page
= page
->index
;
2412 mpd
->next_page
= page
->index
+ 1;
2413 logical
= (sector_t
) page
->index
<<
2414 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2416 if (!page_has_buffers(page
)) {
2417 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2418 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2420 return MPAGE_DA_EXTENT_TAIL
;
2423 * Page with regular buffer heads, just add all dirty ones
2425 head
= page_buffers(page
);
2428 BUG_ON(buffer_locked(bh
));
2430 * We need to try to allocate
2431 * unmapped blocks in the same page.
2432 * Otherwise we won't make progress
2433 * with the page in ext4_writepage
2435 if (ext4_bh_delay_or_unwritten(NULL
, bh
)) {
2436 mpage_add_bh_to_extent(mpd
, logical
,
2440 return MPAGE_DA_EXTENT_TAIL
;
2441 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2443 * mapped dirty buffer. We need to update
2444 * the b_state because we look at
2445 * b_state in mpage_da_map_blocks. We don't
2446 * update b_size because if we find an
2447 * unmapped buffer_head later we need to
2448 * use the b_state flag of that buffer_head.
2450 if (mpd
->b_size
== 0)
2451 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2454 } while ((bh
= bh
->b_this_page
) != head
);
2461 * This is a special get_blocks_t callback which is used by
2462 * ext4_da_write_begin(). It will either return mapped block or
2463 * reserve space for a single block.
2465 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2466 * We also have b_blocknr = -1 and b_bdev initialized properly
2468 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2469 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2470 * initialized properly.
2472 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2473 struct buffer_head
*bh_result
, int create
)
2476 sector_t invalid_block
= ~((sector_t
) 0xffff);
2478 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
2481 BUG_ON(create
== 0);
2482 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2485 * first, we need to know whether the block is allocated already
2486 * preallocated blocks are unmapped but should treated
2487 * the same as allocated blocks.
2489 ret
= ext4_get_blocks(NULL
, inode
, iblock
, 1, bh_result
, 0);
2490 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2491 /* the block isn't (pre)allocated yet, let's reserve space */
2493 * XXX: __block_prepare_write() unmaps passed block,
2496 ret
= ext4_da_reserve_space(inode
, 1);
2498 /* not enough space to reserve */
2501 map_bh(bh_result
, inode
->i_sb
, invalid_block
);
2502 set_buffer_new(bh_result
);
2503 set_buffer_delay(bh_result
);
2504 } else if (ret
> 0) {
2505 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2506 if (buffer_unwritten(bh_result
)) {
2507 /* A delayed write to unwritten bh should
2508 * be marked new and mapped. Mapped ensures
2509 * that we don't do get_block multiple times
2510 * when we write to the same offset and new
2511 * ensures that we do proper zero out for
2514 set_buffer_new(bh_result
);
2515 set_buffer_mapped(bh_result
);
2524 * This function is used as a standard get_block_t calback function
2525 * when there is no desire to allocate any blocks. It is used as a
2526 * callback function for block_prepare_write(), nobh_writepage(), and
2527 * block_write_full_page(). These functions should only try to map a
2528 * single block at a time.
2530 * Since this function doesn't do block allocations even if the caller
2531 * requests it by passing in create=1, it is critically important that
2532 * any caller checks to make sure that any buffer heads are returned
2533 * by this function are either all already mapped or marked for
2534 * delayed allocation before calling nobh_writepage() or
2535 * block_write_full_page(). Otherwise, b_blocknr could be left
2536 * unitialized, and the page write functions will be taken by
2539 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
2540 struct buffer_head
*bh_result
, int create
)
2543 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2545 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2548 * we don't want to do block allocation in writepage
2549 * so call get_block_wrap with create = 0
2551 ret
= ext4_get_blocks(NULL
, inode
, iblock
, max_blocks
, bh_result
, 0);
2553 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2559 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2565 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2571 static int __ext4_journalled_writepage(struct page
*page
,
2574 struct address_space
*mapping
= page
->mapping
;
2575 struct inode
*inode
= mapping
->host
;
2576 struct buffer_head
*page_bufs
;
2577 handle_t
*handle
= NULL
;
2581 page_bufs
= page_buffers(page
);
2583 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bget_one
);
2584 /* As soon as we unlock the page, it can go away, but we have
2585 * references to buffers so we are safe */
2588 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
2589 if (IS_ERR(handle
)) {
2590 ret
= PTR_ERR(handle
);
2594 ret
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2595 do_journal_get_write_access
);
2597 err
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2601 err
= ext4_journal_stop(handle
);
2605 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bput_one
);
2606 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
2612 * Note that we don't need to start a transaction unless we're journaling data
2613 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2614 * need to file the inode to the transaction's list in ordered mode because if
2615 * we are writing back data added by write(), the inode is already there and if
2616 * we are writing back data modified via mmap(), noone guarantees in which
2617 * transaction the data will hit the disk. In case we are journaling data, we
2618 * cannot start transaction directly because transaction start ranks above page
2619 * lock so we have to do some magic.
2621 * This function can get called via...
2622 * - ext4_da_writepages after taking page lock (have journal handle)
2623 * - journal_submit_inode_data_buffers (no journal handle)
2624 * - shrink_page_list via pdflush (no journal handle)
2625 * - grab_page_cache when doing write_begin (have journal handle)
2627 * We don't do any block allocation in this function. If we have page with
2628 * multiple blocks we need to write those buffer_heads that are mapped. This
2629 * is important for mmaped based write. So if we do with blocksize 1K
2630 * truncate(f, 1024);
2631 * a = mmap(f, 0, 4096);
2633 * truncate(f, 4096);
2634 * we have in the page first buffer_head mapped via page_mkwrite call back
2635 * but other bufer_heads would be unmapped but dirty(dirty done via the
2636 * do_wp_page). So writepage should write the first block. If we modify
2637 * the mmap area beyond 1024 we will again get a page_fault and the
2638 * page_mkwrite callback will do the block allocation and mark the
2639 * buffer_heads mapped.
2641 * We redirty the page if we have any buffer_heads that is either delay or
2642 * unwritten in the page.
2644 * We can get recursively called as show below.
2646 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2649 * But since we don't do any block allocation we should not deadlock.
2650 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2652 static int ext4_writepage(struct page
*page
,
2653 struct writeback_control
*wbc
)
2658 struct buffer_head
*page_bufs
;
2659 struct inode
*inode
= page
->mapping
->host
;
2661 trace_ext4_writepage(inode
, page
);
2662 size
= i_size_read(inode
);
2663 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2664 len
= size
& ~PAGE_CACHE_MASK
;
2666 len
= PAGE_CACHE_SIZE
;
2668 if (page_has_buffers(page
)) {
2669 page_bufs
= page_buffers(page
);
2670 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2671 ext4_bh_delay_or_unwritten
)) {
2673 * We don't want to do block allocation
2674 * So redirty the page and return
2675 * We may reach here when we do a journal commit
2676 * via journal_submit_inode_data_buffers.
2677 * If we don't have mapping block we just ignore
2678 * them. We can also reach here via shrink_page_list
2680 redirty_page_for_writepage(wbc
, page
);
2686 * The test for page_has_buffers() is subtle:
2687 * We know the page is dirty but it lost buffers. That means
2688 * that at some moment in time after write_begin()/write_end()
2689 * has been called all buffers have been clean and thus they
2690 * must have been written at least once. So they are all
2691 * mapped and we can happily proceed with mapping them
2692 * and writing the page.
2694 * Try to initialize the buffer_heads and check whether
2695 * all are mapped and non delay. We don't want to
2696 * do block allocation here.
2698 ret
= block_prepare_write(page
, 0, len
,
2699 noalloc_get_block_write
);
2701 page_bufs
= page_buffers(page
);
2702 /* check whether all are mapped and non delay */
2703 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2704 ext4_bh_delay_or_unwritten
)) {
2705 redirty_page_for_writepage(wbc
, page
);
2711 * We can't do block allocation here
2712 * so just redity the page and unlock
2715 redirty_page_for_writepage(wbc
, page
);
2719 /* now mark the buffer_heads as dirty and uptodate */
2720 block_commit_write(page
, 0, len
);
2723 if (PageChecked(page
) && ext4_should_journal_data(inode
)) {
2725 * It's mmapped pagecache. Add buffers and journal it. There
2726 * doesn't seem much point in redirtying the page here.
2728 ClearPageChecked(page
);
2729 return __ext4_journalled_writepage(page
, len
);
2732 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2733 ret
= nobh_writepage(page
, noalloc_get_block_write
, wbc
);
2735 ret
= block_write_full_page(page
, noalloc_get_block_write
,
2742 * This is called via ext4_da_writepages() to
2743 * calulate the total number of credits to reserve to fit
2744 * a single extent allocation into a single transaction,
2745 * ext4_da_writpeages() will loop calling this before
2746 * the block allocation.
2749 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2751 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2754 * With non-extent format the journal credit needed to
2755 * insert nrblocks contiguous block is dependent on
2756 * number of contiguous block. So we will limit
2757 * number of contiguous block to a sane value
2759 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) &&
2760 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2761 max_blocks
= EXT4_MAX_TRANS_DATA
;
2763 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2766 static int ext4_da_writepages(struct address_space
*mapping
,
2767 struct writeback_control
*wbc
)
2770 int range_whole
= 0;
2771 handle_t
*handle
= NULL
;
2772 struct mpage_da_data mpd
;
2773 struct inode
*inode
= mapping
->host
;
2774 int no_nrwrite_index_update
;
2775 int pages_written
= 0;
2777 unsigned int max_pages
;
2778 int range_cyclic
, cycled
= 1, io_done
= 0;
2779 int needed_blocks
, ret
= 0;
2780 long desired_nr_to_write
, nr_to_writebump
= 0;
2781 loff_t range_start
= wbc
->range_start
;
2782 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2784 trace_ext4_da_writepages(inode
, wbc
);
2787 * No pages to write? This is mainly a kludge to avoid starting
2788 * a transaction for special inodes like journal inode on last iput()
2789 * because that could violate lock ordering on umount
2791 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2795 * If the filesystem has aborted, it is read-only, so return
2796 * right away instead of dumping stack traces later on that
2797 * will obscure the real source of the problem. We test
2798 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2799 * the latter could be true if the filesystem is mounted
2800 * read-only, and in that case, ext4_da_writepages should
2801 * *never* be called, so if that ever happens, we would want
2804 if (unlikely(sbi
->s_mount_flags
& EXT4_MF_FS_ABORTED
))
2807 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2810 range_cyclic
= wbc
->range_cyclic
;
2811 if (wbc
->range_cyclic
) {
2812 index
= mapping
->writeback_index
;
2815 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2816 wbc
->range_end
= LLONG_MAX
;
2817 wbc
->range_cyclic
= 0;
2819 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2822 * This works around two forms of stupidity. The first is in
2823 * the writeback code, which caps the maximum number of pages
2824 * written to be 1024 pages. This is wrong on multiple
2825 * levels; different architectues have a different page size,
2826 * which changes the maximum amount of data which gets
2827 * written. Secondly, 4 megabytes is way too small. XFS
2828 * forces this value to be 16 megabytes by multiplying
2829 * nr_to_write parameter by four, and then relies on its
2830 * allocator to allocate larger extents to make them
2831 * contiguous. Unfortunately this brings us to the second
2832 * stupidity, which is that ext4's mballoc code only allocates
2833 * at most 2048 blocks. So we force contiguous writes up to
2834 * the number of dirty blocks in the inode, or
2835 * sbi->max_writeback_mb_bump whichever is smaller.
2837 max_pages
= sbi
->s_max_writeback_mb_bump
<< (20 - PAGE_CACHE_SHIFT
);
2838 if (!range_cyclic
&& range_whole
)
2839 desired_nr_to_write
= wbc
->nr_to_write
* 8;
2841 desired_nr_to_write
= ext4_num_dirty_pages(inode
, index
,
2843 if (desired_nr_to_write
> max_pages
)
2844 desired_nr_to_write
= max_pages
;
2846 if (wbc
->nr_to_write
< desired_nr_to_write
) {
2847 nr_to_writebump
= desired_nr_to_write
- wbc
->nr_to_write
;
2848 wbc
->nr_to_write
= desired_nr_to_write
;
2852 mpd
.inode
= mapping
->host
;
2855 * we don't want write_cache_pages to update
2856 * nr_to_write and writeback_index
2858 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2859 wbc
->no_nrwrite_index_update
= 1;
2860 pages_skipped
= wbc
->pages_skipped
;
2863 while (!ret
&& wbc
->nr_to_write
> 0) {
2866 * we insert one extent at a time. So we need
2867 * credit needed for single extent allocation.
2868 * journalled mode is currently not supported
2871 BUG_ON(ext4_should_journal_data(inode
));
2872 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2874 /* start a new transaction*/
2875 handle
= ext4_journal_start(inode
, needed_blocks
);
2876 if (IS_ERR(handle
)) {
2877 ret
= PTR_ERR(handle
);
2878 ext4_msg(inode
->i_sb
, KERN_CRIT
, "%s: jbd2_start: "
2879 "%ld pages, ino %lu; err %d\n", __func__
,
2880 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2881 goto out_writepages
;
2885 * Now call __mpage_da_writepage to find the next
2886 * contiguous region of logical blocks that need
2887 * blocks to be allocated by ext4. We don't actually
2888 * submit the blocks for I/O here, even though
2889 * write_cache_pages thinks it will, and will set the
2890 * pages as clean for write before calling
2891 * __mpage_da_writepage().
2899 mpd
.pages_written
= 0;
2901 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
,
2904 * If we have a contiguous extent of pages and we
2905 * haven't done the I/O yet, map the blocks and submit
2908 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
2909 if (mpage_da_map_blocks(&mpd
) == 0)
2910 mpage_da_submit_io(&mpd
);
2912 ret
= MPAGE_DA_EXTENT_TAIL
;
2914 trace_ext4_da_write_pages(inode
, &mpd
);
2915 wbc
->nr_to_write
-= mpd
.pages_written
;
2917 ext4_journal_stop(handle
);
2919 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2920 /* commit the transaction which would
2921 * free blocks released in the transaction
2924 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2925 wbc
->pages_skipped
= pages_skipped
;
2927 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2929 * got one extent now try with
2932 pages_written
+= mpd
.pages_written
;
2933 wbc
->pages_skipped
= pages_skipped
;
2936 } else if (wbc
->nr_to_write
)
2938 * There is no more writeout needed
2939 * or we requested for a noblocking writeout
2940 * and we found the device congested
2944 if (!io_done
&& !cycled
) {
2947 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2948 wbc
->range_end
= mapping
->writeback_index
- 1;
2951 if (pages_skipped
!= wbc
->pages_skipped
)
2952 ext4_msg(inode
->i_sb
, KERN_CRIT
,
2953 "This should not happen leaving %s "
2954 "with nr_to_write = %ld ret = %d\n",
2955 __func__
, wbc
->nr_to_write
, ret
);
2958 index
+= pages_written
;
2959 wbc
->range_cyclic
= range_cyclic
;
2960 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2962 * set the writeback_index so that range_cyclic
2963 * mode will write it back later
2965 mapping
->writeback_index
= index
;
2968 if (!no_nrwrite_index_update
)
2969 wbc
->no_nrwrite_index_update
= 0;
2970 if (wbc
->nr_to_write
> nr_to_writebump
)
2971 wbc
->nr_to_write
-= nr_to_writebump
;
2972 wbc
->range_start
= range_start
;
2973 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
2977 #define FALL_BACK_TO_NONDELALLOC 1
2978 static int ext4_nonda_switch(struct super_block
*sb
)
2980 s64 free_blocks
, dirty_blocks
;
2981 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2984 * switch to non delalloc mode if we are running low
2985 * on free block. The free block accounting via percpu
2986 * counters can get slightly wrong with percpu_counter_batch getting
2987 * accumulated on each CPU without updating global counters
2988 * Delalloc need an accurate free block accounting. So switch
2989 * to non delalloc when we are near to error range.
2991 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
2992 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
2993 if (2 * free_blocks
< 3 * dirty_blocks
||
2994 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
2996 * free block count is less than 150% of dirty blocks
2997 * or free blocks is less than watermark
3002 * Even if we don't switch but are nearing capacity,
3003 * start pushing delalloc when 1/2 of free blocks are dirty.
3005 if (free_blocks
< 2 * dirty_blocks
)
3006 writeback_inodes_sb_if_idle(sb
);
3011 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
3012 loff_t pos
, unsigned len
, unsigned flags
,
3013 struct page
**pagep
, void **fsdata
)
3015 int ret
, retries
= 0;
3019 struct inode
*inode
= mapping
->host
;
3022 index
= pos
>> PAGE_CACHE_SHIFT
;
3023 from
= pos
& (PAGE_CACHE_SIZE
- 1);
3026 if (ext4_nonda_switch(inode
->i_sb
)) {
3027 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
3028 return ext4_write_begin(file
, mapping
, pos
,
3029 len
, flags
, pagep
, fsdata
);
3031 *fsdata
= (void *)0;
3032 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
3035 * With delayed allocation, we don't log the i_disksize update
3036 * if there is delayed block allocation. But we still need
3037 * to journalling the i_disksize update if writes to the end
3038 * of file which has an already mapped buffer.
3040 handle
= ext4_journal_start(inode
, 1);
3041 if (IS_ERR(handle
)) {
3042 ret
= PTR_ERR(handle
);
3045 /* We cannot recurse into the filesystem as the transaction is already
3047 flags
|= AOP_FLAG_NOFS
;
3049 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
3051 ext4_journal_stop(handle
);
3057 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
3058 ext4_da_get_block_prep
);
3061 ext4_journal_stop(handle
);
3062 page_cache_release(page
);
3064 * block_write_begin may have instantiated a few blocks
3065 * outside i_size. Trim these off again. Don't need
3066 * i_size_read because we hold i_mutex.
3068 if (pos
+ len
> inode
->i_size
)
3069 ext4_truncate_failed_write(inode
);
3072 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3079 * Check if we should update i_disksize
3080 * when write to the end of file but not require block allocation
3082 static int ext4_da_should_update_i_disksize(struct page
*page
,
3083 unsigned long offset
)
3085 struct buffer_head
*bh
;
3086 struct inode
*inode
= page
->mapping
->host
;
3090 bh
= page_buffers(page
);
3091 idx
= offset
>> inode
->i_blkbits
;
3093 for (i
= 0; i
< idx
; i
++)
3094 bh
= bh
->b_this_page
;
3096 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
3101 static int ext4_da_write_end(struct file
*file
,
3102 struct address_space
*mapping
,
3103 loff_t pos
, unsigned len
, unsigned copied
,
3104 struct page
*page
, void *fsdata
)
3106 struct inode
*inode
= mapping
->host
;
3108 handle_t
*handle
= ext4_journal_current_handle();
3110 unsigned long start
, end
;
3111 int write_mode
= (int)(unsigned long)fsdata
;
3113 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
3114 if (ext4_should_order_data(inode
)) {
3115 return ext4_ordered_write_end(file
, mapping
, pos
,
3116 len
, copied
, page
, fsdata
);
3117 } else if (ext4_should_writeback_data(inode
)) {
3118 return ext4_writeback_write_end(file
, mapping
, pos
,
3119 len
, copied
, page
, fsdata
);
3125 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
3126 start
= pos
& (PAGE_CACHE_SIZE
- 1);
3127 end
= start
+ copied
- 1;
3130 * generic_write_end() will run mark_inode_dirty() if i_size
3131 * changes. So let's piggyback the i_disksize mark_inode_dirty
3135 new_i_size
= pos
+ copied
;
3136 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3137 if (ext4_da_should_update_i_disksize(page
, end
)) {
3138 down_write(&EXT4_I(inode
)->i_data_sem
);
3139 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3141 * Updating i_disksize when extending file
3142 * without needing block allocation
3144 if (ext4_should_order_data(inode
))
3145 ret
= ext4_jbd2_file_inode(handle
,
3148 EXT4_I(inode
)->i_disksize
= new_i_size
;
3150 up_write(&EXT4_I(inode
)->i_data_sem
);
3151 /* We need to mark inode dirty even if
3152 * new_i_size is less that inode->i_size
3153 * bu greater than i_disksize.(hint delalloc)
3155 ext4_mark_inode_dirty(handle
, inode
);
3158 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
3163 ret2
= ext4_journal_stop(handle
);
3167 return ret
? ret
: copied
;
3170 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
3173 * Drop reserved blocks
3175 BUG_ON(!PageLocked(page
));
3176 if (!page_has_buffers(page
))
3179 ext4_da_page_release_reservation(page
, offset
);
3182 ext4_invalidatepage(page
, offset
);
3188 * Force all delayed allocation blocks to be allocated for a given inode.
3190 int ext4_alloc_da_blocks(struct inode
*inode
)
3192 trace_ext4_alloc_da_blocks(inode
);
3194 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
3195 !EXT4_I(inode
)->i_reserved_meta_blocks
)
3199 * We do something simple for now. The filemap_flush() will
3200 * also start triggering a write of the data blocks, which is
3201 * not strictly speaking necessary (and for users of
3202 * laptop_mode, not even desirable). However, to do otherwise
3203 * would require replicating code paths in:
3205 * ext4_da_writepages() ->
3206 * write_cache_pages() ---> (via passed in callback function)
3207 * __mpage_da_writepage() -->
3208 * mpage_add_bh_to_extent()
3209 * mpage_da_map_blocks()
3211 * The problem is that write_cache_pages(), located in
3212 * mm/page-writeback.c, marks pages clean in preparation for
3213 * doing I/O, which is not desirable if we're not planning on
3216 * We could call write_cache_pages(), and then redirty all of
3217 * the pages by calling redirty_page_for_writeback() but that
3218 * would be ugly in the extreme. So instead we would need to
3219 * replicate parts of the code in the above functions,
3220 * simplifying them becuase we wouldn't actually intend to
3221 * write out the pages, but rather only collect contiguous
3222 * logical block extents, call the multi-block allocator, and
3223 * then update the buffer heads with the block allocations.
3225 * For now, though, we'll cheat by calling filemap_flush(),
3226 * which will map the blocks, and start the I/O, but not
3227 * actually wait for the I/O to complete.
3229 return filemap_flush(inode
->i_mapping
);
3233 * bmap() is special. It gets used by applications such as lilo and by
3234 * the swapper to find the on-disk block of a specific piece of data.
3236 * Naturally, this is dangerous if the block concerned is still in the
3237 * journal. If somebody makes a swapfile on an ext4 data-journaling
3238 * filesystem and enables swap, then they may get a nasty shock when the
3239 * data getting swapped to that swapfile suddenly gets overwritten by
3240 * the original zero's written out previously to the journal and
3241 * awaiting writeback in the kernel's buffer cache.
3243 * So, if we see any bmap calls here on a modified, data-journaled file,
3244 * take extra steps to flush any blocks which might be in the cache.
3246 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
3248 struct inode
*inode
= mapping
->host
;
3252 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
3253 test_opt(inode
->i_sb
, DELALLOC
)) {
3255 * With delalloc we want to sync the file
3256 * so that we can make sure we allocate
3259 filemap_write_and_wait(mapping
);
3262 if (EXT4_JOURNAL(inode
) && EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
3264 * This is a REALLY heavyweight approach, but the use of
3265 * bmap on dirty files is expected to be extremely rare:
3266 * only if we run lilo or swapon on a freshly made file
3267 * do we expect this to happen.
3269 * (bmap requires CAP_SYS_RAWIO so this does not
3270 * represent an unprivileged user DOS attack --- we'd be
3271 * in trouble if mortal users could trigger this path at
3274 * NB. EXT4_STATE_JDATA is not set on files other than
3275 * regular files. If somebody wants to bmap a directory
3276 * or symlink and gets confused because the buffer
3277 * hasn't yet been flushed to disk, they deserve
3278 * everything they get.
3281 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
3282 journal
= EXT4_JOURNAL(inode
);
3283 jbd2_journal_lock_updates(journal
);
3284 err
= jbd2_journal_flush(journal
);
3285 jbd2_journal_unlock_updates(journal
);
3291 return generic_block_bmap(mapping
, block
, ext4_get_block
);
3294 static int ext4_readpage(struct file
*file
, struct page
*page
)
3296 return mpage_readpage(page
, ext4_get_block
);
3300 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3301 struct list_head
*pages
, unsigned nr_pages
)
3303 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3306 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3308 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3311 * If it's a full truncate we just forget about the pending dirtying
3314 ClearPageChecked(page
);
3317 jbd2_journal_invalidatepage(journal
, page
, offset
);
3319 block_invalidatepage(page
, offset
);
3322 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3324 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3326 WARN_ON(PageChecked(page
));
3327 if (!page_has_buffers(page
))
3330 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3332 return try_to_free_buffers(page
);
3336 * O_DIRECT for ext3 (or indirect map) based files
3338 * If the O_DIRECT write will extend the file then add this inode to the
3339 * orphan list. So recovery will truncate it back to the original size
3340 * if the machine crashes during the write.
3342 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3343 * crashes then stale disk data _may_ be exposed inside the file. But current
3344 * VFS code falls back into buffered path in that case so we are safe.
3346 static ssize_t
ext4_ind_direct_IO(int rw
, struct kiocb
*iocb
,
3347 const struct iovec
*iov
, loff_t offset
,
3348 unsigned long nr_segs
)
3350 struct file
*file
= iocb
->ki_filp
;
3351 struct inode
*inode
= file
->f_mapping
->host
;
3352 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3356 size_t count
= iov_length(iov
, nr_segs
);
3360 loff_t final_size
= offset
+ count
;
3362 if (final_size
> inode
->i_size
) {
3363 /* Credits for sb + inode write */
3364 handle
= ext4_journal_start(inode
, 2);
3365 if (IS_ERR(handle
)) {
3366 ret
= PTR_ERR(handle
);
3369 ret
= ext4_orphan_add(handle
, inode
);
3371 ext4_journal_stop(handle
);
3375 ei
->i_disksize
= inode
->i_size
;
3376 ext4_journal_stop(handle
);
3381 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3383 ext4_get_block
, NULL
);
3384 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3390 /* Credits for sb + inode write */
3391 handle
= ext4_journal_start(inode
, 2);
3392 if (IS_ERR(handle
)) {
3393 /* This is really bad luck. We've written the data
3394 * but cannot extend i_size. Bail out and pretend
3395 * the write failed... */
3396 ret
= PTR_ERR(handle
);
3400 ext4_orphan_del(handle
, inode
);
3402 loff_t end
= offset
+ ret
;
3403 if (end
> inode
->i_size
) {
3404 ei
->i_disksize
= end
;
3405 i_size_write(inode
, end
);
3407 * We're going to return a positive `ret'
3408 * here due to non-zero-length I/O, so there's
3409 * no way of reporting error returns from
3410 * ext4_mark_inode_dirty() to userspace. So
3413 ext4_mark_inode_dirty(handle
, inode
);
3416 err
= ext4_journal_stop(handle
);
3424 static int ext4_get_block_dio_write(struct inode
*inode
, sector_t iblock
,
3425 struct buffer_head
*bh_result
, int create
)
3427 handle_t
*handle
= NULL
;
3429 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
3432 ext4_debug("ext4_get_block_dio_write: inode %lu, create flag %d\n",
3433 inode
->i_ino
, create
);
3435 * DIO VFS code passes create = 0 flag for write to
3436 * the middle of file. It does this to avoid block
3437 * allocation for holes, to prevent expose stale data
3438 * out when there is parallel buffered read (which does
3439 * not hold the i_mutex lock) while direct IO write has
3440 * not completed. DIO request on holes finally falls back
3441 * to buffered IO for this reason.
3443 * For ext4 extent based file, since we support fallocate,
3444 * new allocated extent as uninitialized, for holes, we
3445 * could fallocate blocks for holes, thus parallel
3446 * buffered IO read will zero out the page when read on
3447 * a hole while parallel DIO write to the hole has not completed.
3449 * when we come here, we know it's a direct IO write to
3450 * to the middle of file (<i_size)
3451 * so it's safe to override the create flag from VFS.
3453 create
= EXT4_GET_BLOCKS_DIO_CREATE_EXT
;
3455 if (max_blocks
> DIO_MAX_BLOCKS
)
3456 max_blocks
= DIO_MAX_BLOCKS
;
3457 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
3458 handle
= ext4_journal_start(inode
, dio_credits
);
3459 if (IS_ERR(handle
)) {
3460 ret
= PTR_ERR(handle
);
3463 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
3466 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
3469 ext4_journal_stop(handle
);
3474 static void ext4_free_io_end(ext4_io_end_t
*io
)
3480 static void dump_aio_dio_list(struct inode
* inode
)
3483 struct list_head
*cur
, *before
, *after
;
3484 ext4_io_end_t
*io
, *io0
, *io1
;
3486 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3487 ext4_debug("inode %lu aio dio list is empty\n", inode
->i_ino
);
3491 ext4_debug("Dump inode %lu aio_dio_completed_IO list \n", inode
->i_ino
);
3492 list_for_each_entry(io
, &EXT4_I(inode
)->i_aio_dio_complete_list
, list
){
3495 io0
= container_of(before
, ext4_io_end_t
, list
);
3497 io1
= container_of(after
, ext4_io_end_t
, list
);
3499 ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
3500 io
, inode
->i_ino
, io0
, io1
);
3506 * check a range of space and convert unwritten extents to written.
3508 static int ext4_end_aio_dio_nolock(ext4_io_end_t
*io
)
3510 struct inode
*inode
= io
->inode
;
3511 loff_t offset
= io
->offset
;
3512 size_t size
= io
->size
;
3515 ext4_debug("end_aio_dio_onlock: io 0x%p from inode %lu,list->next 0x%p,"
3516 "list->prev 0x%p\n",
3517 io
, inode
->i_ino
, io
->list
.next
, io
->list
.prev
);
3519 if (list_empty(&io
->list
))
3522 if (io
->flag
!= DIO_AIO_UNWRITTEN
)
3525 if (offset
+ size
<= i_size_read(inode
))
3526 ret
= ext4_convert_unwritten_extents(inode
, offset
, size
);
3529 printk(KERN_EMERG
"%s: failed to convert unwritten"
3530 "extents to written extents, error is %d"
3531 " io is still on inode %lu aio dio list\n",
3532 __func__
, ret
, inode
->i_ino
);
3536 /* clear the DIO AIO unwritten flag */
3541 * work on completed aio dio IO, to convert unwritten extents to extents
3543 static void ext4_end_aio_dio_work(struct work_struct
*work
)
3545 ext4_io_end_t
*io
= container_of(work
, ext4_io_end_t
, work
);
3546 struct inode
*inode
= io
->inode
;
3549 mutex_lock(&inode
->i_mutex
);
3550 ret
= ext4_end_aio_dio_nolock(io
);
3552 if (!list_empty(&io
->list
))
3553 list_del_init(&io
->list
);
3554 ext4_free_io_end(io
);
3556 mutex_unlock(&inode
->i_mutex
);
3559 * This function is called from ext4_sync_file().
3561 * When AIO DIO IO is completed, the work to convert unwritten
3562 * extents to written is queued on workqueue but may not get immediately
3563 * scheduled. When fsync is called, we need to ensure the
3564 * conversion is complete before fsync returns.
3565 * The inode keeps track of a list of completed AIO from DIO path
3566 * that might needs to do the conversion. This function walks through
3567 * the list and convert the related unwritten extents to written.
3569 int flush_aio_dio_completed_IO(struct inode
*inode
)
3575 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
))
3578 dump_aio_dio_list(inode
);
3579 while (!list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3580 io
= list_entry(EXT4_I(inode
)->i_aio_dio_complete_list
.next
,
3581 ext4_io_end_t
, list
);
3583 * Calling ext4_end_aio_dio_nolock() to convert completed
3586 * When ext4_sync_file() is called, run_queue() may already
3587 * about to flush the work corresponding to this io structure.
3588 * It will be upset if it founds the io structure related
3589 * to the work-to-be schedule is freed.
3591 * Thus we need to keep the io structure still valid here after
3592 * convertion finished. The io structure has a flag to
3593 * avoid double converting from both fsync and background work
3596 ret
= ext4_end_aio_dio_nolock(io
);
3600 list_del_init(&io
->list
);
3602 return (ret2
< 0) ? ret2
: 0;
3605 static ext4_io_end_t
*ext4_init_io_end (struct inode
*inode
)
3607 ext4_io_end_t
*io
= NULL
;
3609 io
= kmalloc(sizeof(*io
), GFP_NOFS
);
3618 INIT_WORK(&io
->work
, ext4_end_aio_dio_work
);
3619 INIT_LIST_HEAD(&io
->list
);
3625 static void ext4_end_io_dio(struct kiocb
*iocb
, loff_t offset
,
3626 ssize_t size
, void *private)
3628 ext4_io_end_t
*io_end
= iocb
->private;
3629 struct workqueue_struct
*wq
;
3631 /* if not async direct IO or dio with 0 bytes write, just return */
3632 if (!io_end
|| !size
)
3635 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3636 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3637 iocb
->private, io_end
->inode
->i_ino
, iocb
, offset
,
3640 /* if not aio dio with unwritten extents, just free io and return */
3641 if (io_end
->flag
!= DIO_AIO_UNWRITTEN
){
3642 ext4_free_io_end(io_end
);
3643 iocb
->private = NULL
;
3647 io_end
->offset
= offset
;
3648 io_end
->size
= size
;
3649 wq
= EXT4_SB(io_end
->inode
->i_sb
)->dio_unwritten_wq
;
3651 /* queue the work to convert unwritten extents to written */
3652 queue_work(wq
, &io_end
->work
);
3654 /* Add the io_end to per-inode completed aio dio list*/
3655 list_add_tail(&io_end
->list
,
3656 &EXT4_I(io_end
->inode
)->i_aio_dio_complete_list
);
3657 iocb
->private = NULL
;
3660 * For ext4 extent files, ext4 will do direct-io write to holes,
3661 * preallocated extents, and those write extend the file, no need to
3662 * fall back to buffered IO.
3664 * For holes, we fallocate those blocks, mark them as unintialized
3665 * If those blocks were preallocated, we mark sure they are splited, but
3666 * still keep the range to write as unintialized.
3668 * The unwrritten extents will be converted to written when DIO is completed.
3669 * For async direct IO, since the IO may still pending when return, we
3670 * set up an end_io call back function, which will do the convertion
3671 * when async direct IO completed.
3673 * If the O_DIRECT write will extend the file then add this inode to the
3674 * orphan list. So recovery will truncate it back to the original size
3675 * if the machine crashes during the write.
3678 static ssize_t
ext4_ext_direct_IO(int rw
, struct kiocb
*iocb
,
3679 const struct iovec
*iov
, loff_t offset
,
3680 unsigned long nr_segs
)
3682 struct file
*file
= iocb
->ki_filp
;
3683 struct inode
*inode
= file
->f_mapping
->host
;
3685 size_t count
= iov_length(iov
, nr_segs
);
3687 loff_t final_size
= offset
+ count
;
3688 if (rw
== WRITE
&& final_size
<= inode
->i_size
) {
3690 * We could direct write to holes and fallocate.
3692 * Allocated blocks to fill the hole are marked as uninitialized
3693 * to prevent paralel buffered read to expose the stale data
3694 * before DIO complete the data IO.
3696 * As to previously fallocated extents, ext4 get_block
3697 * will just simply mark the buffer mapped but still
3698 * keep the extents uninitialized.
3700 * for non AIO case, we will convert those unwritten extents
3701 * to written after return back from blockdev_direct_IO.
3703 * for async DIO, the conversion needs to be defered when
3704 * the IO is completed. The ext4 end_io callback function
3705 * will be called to take care of the conversion work.
3706 * Here for async case, we allocate an io_end structure to
3709 iocb
->private = NULL
;
3710 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3711 if (!is_sync_kiocb(iocb
)) {
3712 iocb
->private = ext4_init_io_end(inode
);
3716 * we save the io structure for current async
3717 * direct IO, so that later ext4_get_blocks()
3718 * could flag the io structure whether there
3719 * is a unwritten extents needs to be converted
3720 * when IO is completed.
3722 EXT4_I(inode
)->cur_aio_dio
= iocb
->private;
3725 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3726 inode
->i_sb
->s_bdev
, iov
,
3728 ext4_get_block_dio_write
,
3731 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3733 * The io_end structure takes a reference to the inode,
3734 * that structure needs to be destroyed and the
3735 * reference to the inode need to be dropped, when IO is
3736 * complete, even with 0 byte write, or failed.
3738 * In the successful AIO DIO case, the io_end structure will be
3739 * desctroyed and the reference to the inode will be dropped
3740 * after the end_io call back function is called.
3742 * In the case there is 0 byte write, or error case, since
3743 * VFS direct IO won't invoke the end_io call back function,
3744 * we need to free the end_io structure here.
3746 if (ret
!= -EIOCBQUEUED
&& ret
<= 0 && iocb
->private) {
3747 ext4_free_io_end(iocb
->private);
3748 iocb
->private = NULL
;
3749 } else if (ret
> 0 && (EXT4_I(inode
)->i_state
&
3750 EXT4_STATE_DIO_UNWRITTEN
)) {
3753 * for non AIO case, since the IO is already
3754 * completed, we could do the convertion right here
3756 err
= ext4_convert_unwritten_extents(inode
,
3760 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_DIO_UNWRITTEN
;
3765 /* for write the the end of file case, we fall back to old way */
3766 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3769 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3770 const struct iovec
*iov
, loff_t offset
,
3771 unsigned long nr_segs
)
3773 struct file
*file
= iocb
->ki_filp
;
3774 struct inode
*inode
= file
->f_mapping
->host
;
3776 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
3777 return ext4_ext_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3779 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3783 * Pages can be marked dirty completely asynchronously from ext4's journalling
3784 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3785 * much here because ->set_page_dirty is called under VFS locks. The page is
3786 * not necessarily locked.
3788 * We cannot just dirty the page and leave attached buffers clean, because the
3789 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3790 * or jbddirty because all the journalling code will explode.
3792 * So what we do is to mark the page "pending dirty" and next time writepage
3793 * is called, propagate that into the buffers appropriately.
3795 static int ext4_journalled_set_page_dirty(struct page
*page
)
3797 SetPageChecked(page
);
3798 return __set_page_dirty_nobuffers(page
);
3801 static const struct address_space_operations ext4_ordered_aops
= {
3802 .readpage
= ext4_readpage
,
3803 .readpages
= ext4_readpages
,
3804 .writepage
= ext4_writepage
,
3805 .sync_page
= block_sync_page
,
3806 .write_begin
= ext4_write_begin
,
3807 .write_end
= ext4_ordered_write_end
,
3809 .invalidatepage
= ext4_invalidatepage
,
3810 .releasepage
= ext4_releasepage
,
3811 .direct_IO
= ext4_direct_IO
,
3812 .migratepage
= buffer_migrate_page
,
3813 .is_partially_uptodate
= block_is_partially_uptodate
,
3814 .error_remove_page
= generic_error_remove_page
,
3817 static const struct address_space_operations ext4_writeback_aops
= {
3818 .readpage
= ext4_readpage
,
3819 .readpages
= ext4_readpages
,
3820 .writepage
= ext4_writepage
,
3821 .sync_page
= block_sync_page
,
3822 .write_begin
= ext4_write_begin
,
3823 .write_end
= ext4_writeback_write_end
,
3825 .invalidatepage
= ext4_invalidatepage
,
3826 .releasepage
= ext4_releasepage
,
3827 .direct_IO
= ext4_direct_IO
,
3828 .migratepage
= buffer_migrate_page
,
3829 .is_partially_uptodate
= block_is_partially_uptodate
,
3830 .error_remove_page
= generic_error_remove_page
,
3833 static const struct address_space_operations ext4_journalled_aops
= {
3834 .readpage
= ext4_readpage
,
3835 .readpages
= ext4_readpages
,
3836 .writepage
= ext4_writepage
,
3837 .sync_page
= block_sync_page
,
3838 .write_begin
= ext4_write_begin
,
3839 .write_end
= ext4_journalled_write_end
,
3840 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3842 .invalidatepage
= ext4_invalidatepage
,
3843 .releasepage
= ext4_releasepage
,
3844 .is_partially_uptodate
= block_is_partially_uptodate
,
3845 .error_remove_page
= generic_error_remove_page
,
3848 static const struct address_space_operations ext4_da_aops
= {
3849 .readpage
= ext4_readpage
,
3850 .readpages
= ext4_readpages
,
3851 .writepage
= ext4_writepage
,
3852 .writepages
= ext4_da_writepages
,
3853 .sync_page
= block_sync_page
,
3854 .write_begin
= ext4_da_write_begin
,
3855 .write_end
= ext4_da_write_end
,
3857 .invalidatepage
= ext4_da_invalidatepage
,
3858 .releasepage
= ext4_releasepage
,
3859 .direct_IO
= ext4_direct_IO
,
3860 .migratepage
= buffer_migrate_page
,
3861 .is_partially_uptodate
= block_is_partially_uptodate
,
3862 .error_remove_page
= generic_error_remove_page
,
3865 void ext4_set_aops(struct inode
*inode
)
3867 if (ext4_should_order_data(inode
) &&
3868 test_opt(inode
->i_sb
, DELALLOC
))
3869 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3870 else if (ext4_should_order_data(inode
))
3871 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3872 else if (ext4_should_writeback_data(inode
) &&
3873 test_opt(inode
->i_sb
, DELALLOC
))
3874 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3875 else if (ext4_should_writeback_data(inode
))
3876 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3878 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3882 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3883 * up to the end of the block which corresponds to `from'.
3884 * This required during truncate. We need to physically zero the tail end
3885 * of that block so it doesn't yield old data if the file is later grown.
3887 int ext4_block_truncate_page(handle_t
*handle
,
3888 struct address_space
*mapping
, loff_t from
)
3890 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3891 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3892 unsigned blocksize
, length
, pos
;
3894 struct inode
*inode
= mapping
->host
;
3895 struct buffer_head
*bh
;
3899 page
= find_or_create_page(mapping
, from
>> PAGE_CACHE_SHIFT
,
3900 mapping_gfp_mask(mapping
) & ~__GFP_FS
);
3904 blocksize
= inode
->i_sb
->s_blocksize
;
3905 length
= blocksize
- (offset
& (blocksize
- 1));
3906 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3909 * For "nobh" option, we can only work if we don't need to
3910 * read-in the page - otherwise we create buffers to do the IO.
3912 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3913 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3914 zero_user(page
, offset
, length
);
3915 set_page_dirty(page
);
3919 if (!page_has_buffers(page
))
3920 create_empty_buffers(page
, blocksize
, 0);
3922 /* Find the buffer that contains "offset" */
3923 bh
= page_buffers(page
);
3925 while (offset
>= pos
) {
3926 bh
= bh
->b_this_page
;
3932 if (buffer_freed(bh
)) {
3933 BUFFER_TRACE(bh
, "freed: skip");
3937 if (!buffer_mapped(bh
)) {
3938 BUFFER_TRACE(bh
, "unmapped");
3939 ext4_get_block(inode
, iblock
, bh
, 0);
3940 /* unmapped? It's a hole - nothing to do */
3941 if (!buffer_mapped(bh
)) {
3942 BUFFER_TRACE(bh
, "still unmapped");
3947 /* Ok, it's mapped. Make sure it's up-to-date */
3948 if (PageUptodate(page
))
3949 set_buffer_uptodate(bh
);
3951 if (!buffer_uptodate(bh
)) {
3953 ll_rw_block(READ
, 1, &bh
);
3955 /* Uhhuh. Read error. Complain and punt. */
3956 if (!buffer_uptodate(bh
))
3960 if (ext4_should_journal_data(inode
)) {
3961 BUFFER_TRACE(bh
, "get write access");
3962 err
= ext4_journal_get_write_access(handle
, bh
);
3967 zero_user(page
, offset
, length
);
3969 BUFFER_TRACE(bh
, "zeroed end of block");
3972 if (ext4_should_journal_data(inode
)) {
3973 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
3975 if (ext4_should_order_data(inode
))
3976 err
= ext4_jbd2_file_inode(handle
, inode
);
3977 mark_buffer_dirty(bh
);
3982 page_cache_release(page
);
3987 * Probably it should be a library function... search for first non-zero word
3988 * or memcmp with zero_page, whatever is better for particular architecture.
3991 static inline int all_zeroes(__le32
*p
, __le32
*q
)
4000 * ext4_find_shared - find the indirect blocks for partial truncation.
4001 * @inode: inode in question
4002 * @depth: depth of the affected branch
4003 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4004 * @chain: place to store the pointers to partial indirect blocks
4005 * @top: place to the (detached) top of branch
4007 * This is a helper function used by ext4_truncate().
4009 * When we do truncate() we may have to clean the ends of several
4010 * indirect blocks but leave the blocks themselves alive. Block is
4011 * partially truncated if some data below the new i_size is refered
4012 * from it (and it is on the path to the first completely truncated
4013 * data block, indeed). We have to free the top of that path along
4014 * with everything to the right of the path. Since no allocation
4015 * past the truncation point is possible until ext4_truncate()
4016 * finishes, we may safely do the latter, but top of branch may
4017 * require special attention - pageout below the truncation point
4018 * might try to populate it.
4020 * We atomically detach the top of branch from the tree, store the
4021 * block number of its root in *@top, pointers to buffer_heads of
4022 * partially truncated blocks - in @chain[].bh and pointers to
4023 * their last elements that should not be removed - in
4024 * @chain[].p. Return value is the pointer to last filled element
4027 * The work left to caller to do the actual freeing of subtrees:
4028 * a) free the subtree starting from *@top
4029 * b) free the subtrees whose roots are stored in
4030 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4031 * c) free the subtrees growing from the inode past the @chain[0].
4032 * (no partially truncated stuff there). */
4034 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
4035 ext4_lblk_t offsets
[4], Indirect chain
[4],
4038 Indirect
*partial
, *p
;
4042 /* Make k index the deepest non-null offset + 1 */
4043 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
4045 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
4046 /* Writer: pointers */
4048 partial
= chain
+ k
-1;
4050 * If the branch acquired continuation since we've looked at it -
4051 * fine, it should all survive and (new) top doesn't belong to us.
4053 if (!partial
->key
&& *partial
->p
)
4056 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
4059 * OK, we've found the last block that must survive. The rest of our
4060 * branch should be detached before unlocking. However, if that rest
4061 * of branch is all ours and does not grow immediately from the inode
4062 * it's easier to cheat and just decrement partial->p.
4064 if (p
== chain
+ k
- 1 && p
> chain
) {
4068 /* Nope, don't do this in ext4. Must leave the tree intact */
4075 while (partial
> p
) {
4076 brelse(partial
->bh
);
4084 * Zero a number of block pointers in either an inode or an indirect block.
4085 * If we restart the transaction we must again get write access to the
4086 * indirect block for further modification.
4088 * We release `count' blocks on disk, but (last - first) may be greater
4089 * than `count' because there can be holes in there.
4091 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
4092 struct buffer_head
*bh
,
4093 ext4_fsblk_t block_to_free
,
4094 unsigned long count
, __le32
*first
,
4098 int flags
= EXT4_FREE_BLOCKS_FORGET
;
4100 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
4101 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4103 if (try_to_extend_transaction(handle
, inode
)) {
4105 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4106 ext4_handle_dirty_metadata(handle
, inode
, bh
);
4108 ext4_mark_inode_dirty(handle
, inode
);
4109 ext4_truncate_restart_trans(handle
, inode
,
4110 blocks_for_truncate(inode
));
4112 BUFFER_TRACE(bh
, "retaking write access");
4113 ext4_journal_get_write_access(handle
, bh
);
4117 for (p
= first
; p
< last
; p
++)
4120 ext4_free_blocks(handle
, inode
, 0, block_to_free
, count
, flags
);
4124 * ext4_free_data - free a list of data blocks
4125 * @handle: handle for this transaction
4126 * @inode: inode we are dealing with
4127 * @this_bh: indirect buffer_head which contains *@first and *@last
4128 * @first: array of block numbers
4129 * @last: points immediately past the end of array
4131 * We are freeing all blocks refered from that array (numbers are stored as
4132 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4134 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4135 * blocks are contiguous then releasing them at one time will only affect one
4136 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4137 * actually use a lot of journal space.
4139 * @this_bh will be %NULL if @first and @last point into the inode's direct
4142 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
4143 struct buffer_head
*this_bh
,
4144 __le32
*first
, __le32
*last
)
4146 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
4147 unsigned long count
= 0; /* Number of blocks in the run */
4148 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
4151 ext4_fsblk_t nr
; /* Current block # */
4152 __le32
*p
; /* Pointer into inode/ind
4153 for current block */
4156 if (this_bh
) { /* For indirect block */
4157 BUFFER_TRACE(this_bh
, "get_write_access");
4158 err
= ext4_journal_get_write_access(handle
, this_bh
);
4159 /* Important: if we can't update the indirect pointers
4160 * to the blocks, we can't free them. */
4165 for (p
= first
; p
< last
; p
++) {
4166 nr
= le32_to_cpu(*p
);
4168 /* accumulate blocks to free if they're contiguous */
4171 block_to_free_p
= p
;
4173 } else if (nr
== block_to_free
+ count
) {
4176 ext4_clear_blocks(handle
, inode
, this_bh
,
4178 count
, block_to_free_p
, p
);
4180 block_to_free_p
= p
;
4187 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
4188 count
, block_to_free_p
, p
);
4191 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
4194 * The buffer head should have an attached journal head at this
4195 * point. However, if the data is corrupted and an indirect
4196 * block pointed to itself, it would have been detached when
4197 * the block was cleared. Check for this instead of OOPSing.
4199 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
4200 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
4202 ext4_error(inode
->i_sb
, __func__
,
4203 "circular indirect block detected, "
4204 "inode=%lu, block=%llu",
4206 (unsigned long long) this_bh
->b_blocknr
);
4211 * ext4_free_branches - free an array of branches
4212 * @handle: JBD handle for this transaction
4213 * @inode: inode we are dealing with
4214 * @parent_bh: the buffer_head which contains *@first and *@last
4215 * @first: array of block numbers
4216 * @last: pointer immediately past the end of array
4217 * @depth: depth of the branches to free
4219 * We are freeing all blocks refered from these branches (numbers are
4220 * stored as little-endian 32-bit) and updating @inode->i_blocks
4223 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
4224 struct buffer_head
*parent_bh
,
4225 __le32
*first
, __le32
*last
, int depth
)
4230 if (ext4_handle_is_aborted(handle
))
4234 struct buffer_head
*bh
;
4235 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4237 while (--p
>= first
) {
4238 nr
= le32_to_cpu(*p
);
4240 continue; /* A hole */
4242 /* Go read the buffer for the next level down */
4243 bh
= sb_bread(inode
->i_sb
, nr
);
4246 * A read failure? Report error and clear slot
4250 ext4_error(inode
->i_sb
, "ext4_free_branches",
4251 "Read failure, inode=%lu, block=%llu",
4256 /* This zaps the entire block. Bottom up. */
4257 BUFFER_TRACE(bh
, "free child branches");
4258 ext4_free_branches(handle
, inode
, bh
,
4259 (__le32
*) bh
->b_data
,
4260 (__le32
*) bh
->b_data
+ addr_per_block
,
4264 * We've probably journalled the indirect block several
4265 * times during the truncate. But it's no longer
4266 * needed and we now drop it from the transaction via
4267 * jbd2_journal_revoke().
4269 * That's easy if it's exclusively part of this
4270 * transaction. But if it's part of the committing
4271 * transaction then jbd2_journal_forget() will simply
4272 * brelse() it. That means that if the underlying
4273 * block is reallocated in ext4_get_block(),
4274 * unmap_underlying_metadata() will find this block
4275 * and will try to get rid of it. damn, damn.
4277 * If this block has already been committed to the
4278 * journal, a revoke record will be written. And
4279 * revoke records must be emitted *before* clearing
4280 * this block's bit in the bitmaps.
4282 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
4285 * Everything below this this pointer has been
4286 * released. Now let this top-of-subtree go.
4288 * We want the freeing of this indirect block to be
4289 * atomic in the journal with the updating of the
4290 * bitmap block which owns it. So make some room in
4293 * We zero the parent pointer *after* freeing its
4294 * pointee in the bitmaps, so if extend_transaction()
4295 * for some reason fails to put the bitmap changes and
4296 * the release into the same transaction, recovery
4297 * will merely complain about releasing a free block,
4298 * rather than leaking blocks.
4300 if (ext4_handle_is_aborted(handle
))
4302 if (try_to_extend_transaction(handle
, inode
)) {
4303 ext4_mark_inode_dirty(handle
, inode
);
4304 ext4_truncate_restart_trans(handle
, inode
,
4305 blocks_for_truncate(inode
));
4308 ext4_free_blocks(handle
, inode
, 0, nr
, 1,
4309 EXT4_FREE_BLOCKS_METADATA
);
4313 * The block which we have just freed is
4314 * pointed to by an indirect block: journal it
4316 BUFFER_TRACE(parent_bh
, "get_write_access");
4317 if (!ext4_journal_get_write_access(handle
,
4320 BUFFER_TRACE(parent_bh
,
4321 "call ext4_handle_dirty_metadata");
4322 ext4_handle_dirty_metadata(handle
,
4329 /* We have reached the bottom of the tree. */
4330 BUFFER_TRACE(parent_bh
, "free data blocks");
4331 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
4335 int ext4_can_truncate(struct inode
*inode
)
4337 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
4339 if (S_ISREG(inode
->i_mode
))
4341 if (S_ISDIR(inode
->i_mode
))
4343 if (S_ISLNK(inode
->i_mode
))
4344 return !ext4_inode_is_fast_symlink(inode
);
4351 * We block out ext4_get_block() block instantiations across the entire
4352 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4353 * simultaneously on behalf of the same inode.
4355 * As we work through the truncate and commmit bits of it to the journal there
4356 * is one core, guiding principle: the file's tree must always be consistent on
4357 * disk. We must be able to restart the truncate after a crash.
4359 * The file's tree may be transiently inconsistent in memory (although it
4360 * probably isn't), but whenever we close off and commit a journal transaction,
4361 * the contents of (the filesystem + the journal) must be consistent and
4362 * restartable. It's pretty simple, really: bottom up, right to left (although
4363 * left-to-right works OK too).
4365 * Note that at recovery time, journal replay occurs *before* the restart of
4366 * truncate against the orphan inode list.
4368 * The committed inode has the new, desired i_size (which is the same as
4369 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4370 * that this inode's truncate did not complete and it will again call
4371 * ext4_truncate() to have another go. So there will be instantiated blocks
4372 * to the right of the truncation point in a crashed ext4 filesystem. But
4373 * that's fine - as long as they are linked from the inode, the post-crash
4374 * ext4_truncate() run will find them and release them.
4376 void ext4_truncate(struct inode
*inode
)
4379 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4380 __le32
*i_data
= ei
->i_data
;
4381 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4382 struct address_space
*mapping
= inode
->i_mapping
;
4383 ext4_lblk_t offsets
[4];
4388 ext4_lblk_t last_block
;
4389 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
4391 if (!ext4_can_truncate(inode
))
4394 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
4395 ei
->i_state
|= EXT4_STATE_DA_ALLOC_CLOSE
;
4397 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
4398 ext4_ext_truncate(inode
);
4402 handle
= start_transaction(inode
);
4404 return; /* AKPM: return what? */
4406 last_block
= (inode
->i_size
+ blocksize
-1)
4407 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
4409 if (inode
->i_size
& (blocksize
- 1))
4410 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
4413 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
4415 goto out_stop
; /* error */
4418 * OK. This truncate is going to happen. We add the inode to the
4419 * orphan list, so that if this truncate spans multiple transactions,
4420 * and we crash, we will resume the truncate when the filesystem
4421 * recovers. It also marks the inode dirty, to catch the new size.
4423 * Implication: the file must always be in a sane, consistent
4424 * truncatable state while each transaction commits.
4426 if (ext4_orphan_add(handle
, inode
))
4430 * From here we block out all ext4_get_block() callers who want to
4431 * modify the block allocation tree.
4433 down_write(&ei
->i_data_sem
);
4435 ext4_discard_preallocations(inode
);
4438 * The orphan list entry will now protect us from any crash which
4439 * occurs before the truncate completes, so it is now safe to propagate
4440 * the new, shorter inode size (held for now in i_size) into the
4441 * on-disk inode. We do this via i_disksize, which is the value which
4442 * ext4 *really* writes onto the disk inode.
4444 ei
->i_disksize
= inode
->i_size
;
4446 if (n
== 1) { /* direct blocks */
4447 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
4448 i_data
+ EXT4_NDIR_BLOCKS
);
4452 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
4453 /* Kill the top of shared branch (not detached) */
4455 if (partial
== chain
) {
4456 /* Shared branch grows from the inode */
4457 ext4_free_branches(handle
, inode
, NULL
,
4458 &nr
, &nr
+1, (chain
+n
-1) - partial
);
4461 * We mark the inode dirty prior to restart,
4462 * and prior to stop. No need for it here.
4465 /* Shared branch grows from an indirect block */
4466 BUFFER_TRACE(partial
->bh
, "get_write_access");
4467 ext4_free_branches(handle
, inode
, partial
->bh
,
4469 partial
->p
+1, (chain
+n
-1) - partial
);
4472 /* Clear the ends of indirect blocks on the shared branch */
4473 while (partial
> chain
) {
4474 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
4475 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
4476 (chain
+n
-1) - partial
);
4477 BUFFER_TRACE(partial
->bh
, "call brelse");
4478 brelse(partial
->bh
);
4482 /* Kill the remaining (whole) subtrees */
4483 switch (offsets
[0]) {
4485 nr
= i_data
[EXT4_IND_BLOCK
];
4487 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4488 i_data
[EXT4_IND_BLOCK
] = 0;
4490 case EXT4_IND_BLOCK
:
4491 nr
= i_data
[EXT4_DIND_BLOCK
];
4493 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4494 i_data
[EXT4_DIND_BLOCK
] = 0;
4496 case EXT4_DIND_BLOCK
:
4497 nr
= i_data
[EXT4_TIND_BLOCK
];
4499 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4500 i_data
[EXT4_TIND_BLOCK
] = 0;
4502 case EXT4_TIND_BLOCK
:
4506 up_write(&ei
->i_data_sem
);
4507 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4508 ext4_mark_inode_dirty(handle
, inode
);
4511 * In a multi-transaction truncate, we only make the final transaction
4515 ext4_handle_sync(handle
);
4518 * If this was a simple ftruncate(), and the file will remain alive
4519 * then we need to clear up the orphan record which we created above.
4520 * However, if this was a real unlink then we were called by
4521 * ext4_delete_inode(), and we allow that function to clean up the
4522 * orphan info for us.
4525 ext4_orphan_del(handle
, inode
);
4527 ext4_journal_stop(handle
);
4531 * ext4_get_inode_loc returns with an extra refcount against the inode's
4532 * underlying buffer_head on success. If 'in_mem' is true, we have all
4533 * data in memory that is needed to recreate the on-disk version of this
4536 static int __ext4_get_inode_loc(struct inode
*inode
,
4537 struct ext4_iloc
*iloc
, int in_mem
)
4539 struct ext4_group_desc
*gdp
;
4540 struct buffer_head
*bh
;
4541 struct super_block
*sb
= inode
->i_sb
;
4543 int inodes_per_block
, inode_offset
;
4546 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4549 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4550 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4555 * Figure out the offset within the block group inode table
4557 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4558 inode_offset
= ((inode
->i_ino
- 1) %
4559 EXT4_INODES_PER_GROUP(sb
));
4560 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4561 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4563 bh
= sb_getblk(sb
, block
);
4565 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
4566 "inode block - inode=%lu, block=%llu",
4567 inode
->i_ino
, block
);
4570 if (!buffer_uptodate(bh
)) {
4574 * If the buffer has the write error flag, we have failed
4575 * to write out another inode in the same block. In this
4576 * case, we don't have to read the block because we may
4577 * read the old inode data successfully.
4579 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4580 set_buffer_uptodate(bh
);
4582 if (buffer_uptodate(bh
)) {
4583 /* someone brought it uptodate while we waited */
4589 * If we have all information of the inode in memory and this
4590 * is the only valid inode in the block, we need not read the
4594 struct buffer_head
*bitmap_bh
;
4597 start
= inode_offset
& ~(inodes_per_block
- 1);
4599 /* Is the inode bitmap in cache? */
4600 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4605 * If the inode bitmap isn't in cache then the
4606 * optimisation may end up performing two reads instead
4607 * of one, so skip it.
4609 if (!buffer_uptodate(bitmap_bh
)) {
4613 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4614 if (i
== inode_offset
)
4616 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4620 if (i
== start
+ inodes_per_block
) {
4621 /* all other inodes are free, so skip I/O */
4622 memset(bh
->b_data
, 0, bh
->b_size
);
4623 set_buffer_uptodate(bh
);
4631 * If we need to do any I/O, try to pre-readahead extra
4632 * blocks from the inode table.
4634 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4635 ext4_fsblk_t b
, end
, table
;
4638 table
= ext4_inode_table(sb
, gdp
);
4639 /* s_inode_readahead_blks is always a power of 2 */
4640 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4643 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4644 num
= EXT4_INODES_PER_GROUP(sb
);
4645 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4646 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4647 num
-= ext4_itable_unused_count(sb
, gdp
);
4648 table
+= num
/ inodes_per_block
;
4652 sb_breadahead(sb
, b
++);
4656 * There are other valid inodes in the buffer, this inode
4657 * has in-inode xattrs, or we don't have this inode in memory.
4658 * Read the block from disk.
4661 bh
->b_end_io
= end_buffer_read_sync
;
4662 submit_bh(READ_META
, bh
);
4664 if (!buffer_uptodate(bh
)) {
4665 ext4_error(sb
, __func__
,
4666 "unable to read inode block - inode=%lu, "
4667 "block=%llu", inode
->i_ino
, block
);
4677 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4679 /* We have all inode data except xattrs in memory here. */
4680 return __ext4_get_inode_loc(inode
, iloc
,
4681 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4684 void ext4_set_inode_flags(struct inode
*inode
)
4686 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4688 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4689 if (flags
& EXT4_SYNC_FL
)
4690 inode
->i_flags
|= S_SYNC
;
4691 if (flags
& EXT4_APPEND_FL
)
4692 inode
->i_flags
|= S_APPEND
;
4693 if (flags
& EXT4_IMMUTABLE_FL
)
4694 inode
->i_flags
|= S_IMMUTABLE
;
4695 if (flags
& EXT4_NOATIME_FL
)
4696 inode
->i_flags
|= S_NOATIME
;
4697 if (flags
& EXT4_DIRSYNC_FL
)
4698 inode
->i_flags
|= S_DIRSYNC
;
4701 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4702 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4704 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4706 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4707 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4709 ei
->i_flags
|= EXT4_SYNC_FL
;
4710 if (flags
& S_APPEND
)
4711 ei
->i_flags
|= EXT4_APPEND_FL
;
4712 if (flags
& S_IMMUTABLE
)
4713 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4714 if (flags
& S_NOATIME
)
4715 ei
->i_flags
|= EXT4_NOATIME_FL
;
4716 if (flags
& S_DIRSYNC
)
4717 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4720 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4721 struct ext4_inode_info
*ei
)
4724 struct inode
*inode
= &(ei
->vfs_inode
);
4725 struct super_block
*sb
= inode
->i_sb
;
4727 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4728 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4729 /* we are using combined 48 bit field */
4730 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4731 le32_to_cpu(raw_inode
->i_blocks_lo
);
4732 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4733 /* i_blocks represent file system block size */
4734 return i_blocks
<< (inode
->i_blkbits
- 9);
4739 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4743 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4745 struct ext4_iloc iloc
;
4746 struct ext4_inode
*raw_inode
;
4747 struct ext4_inode_info
*ei
;
4748 struct inode
*inode
;
4749 journal_t
*journal
= EXT4_SB(sb
)->s_journal
;
4753 inode
= iget_locked(sb
, ino
);
4755 return ERR_PTR(-ENOMEM
);
4756 if (!(inode
->i_state
& I_NEW
))
4762 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4765 raw_inode
= ext4_raw_inode(&iloc
);
4766 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4767 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4768 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4769 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4770 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4771 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4773 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4776 ei
->i_dir_start_lookup
= 0;
4777 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4778 /* We now have enough fields to check if the inode was active or not.
4779 * This is needed because nfsd might try to access dead inodes
4780 * the test is that same one that e2fsck uses
4781 * NeilBrown 1999oct15
4783 if (inode
->i_nlink
== 0) {
4784 if (inode
->i_mode
== 0 ||
4785 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4786 /* this inode is deleted */
4790 /* The only unlinked inodes we let through here have
4791 * valid i_mode and are being read by the orphan
4792 * recovery code: that's fine, we're about to complete
4793 * the process of deleting those. */
4795 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4796 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4797 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4798 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
4800 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4801 inode
->i_size
= ext4_isize(raw_inode
);
4802 ei
->i_disksize
= inode
->i_size
;
4804 ei
->i_reserved_quota
= 0;
4806 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4807 ei
->i_block_group
= iloc
.block_group
;
4808 ei
->i_last_alloc_group
= ~0;
4810 * NOTE! The in-memory inode i_data array is in little-endian order
4811 * even on big-endian machines: we do NOT byteswap the block numbers!
4813 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4814 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4815 INIT_LIST_HEAD(&ei
->i_orphan
);
4818 * Set transaction id's of transactions that have to be committed
4819 * to finish f[data]sync. We set them to currently running transaction
4820 * as we cannot be sure that the inode or some of its metadata isn't
4821 * part of the transaction - the inode could have been reclaimed and
4822 * now it is reread from disk.
4825 transaction_t
*transaction
;
4828 spin_lock(&journal
->j_state_lock
);
4829 if (journal
->j_running_transaction
)
4830 transaction
= journal
->j_running_transaction
;
4832 transaction
= journal
->j_committing_transaction
;
4834 tid
= transaction
->t_tid
;
4836 tid
= journal
->j_commit_sequence
;
4837 spin_unlock(&journal
->j_state_lock
);
4838 ei
->i_sync_tid
= tid
;
4839 ei
->i_datasync_tid
= tid
;
4842 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4843 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4844 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4845 EXT4_INODE_SIZE(inode
->i_sb
)) {
4849 if (ei
->i_extra_isize
== 0) {
4850 /* The extra space is currently unused. Use it. */
4851 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4852 EXT4_GOOD_OLD_INODE_SIZE
;
4854 __le32
*magic
= (void *)raw_inode
+
4855 EXT4_GOOD_OLD_INODE_SIZE
+
4857 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4858 ei
->i_state
|= EXT4_STATE_XATTR
;
4861 ei
->i_extra_isize
= 0;
4863 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4864 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4865 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4866 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4868 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4869 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4870 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4872 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4876 if (ei
->i_file_acl
&&
4877 !ext4_data_block_valid(EXT4_SB(sb
), ei
->i_file_acl
, 1)) {
4878 ext4_error(sb
, __func__
,
4879 "bad extended attribute block %llu in inode #%lu",
4880 ei
->i_file_acl
, inode
->i_ino
);
4883 } else if (ei
->i_flags
& EXT4_EXTENTS_FL
) {
4884 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4885 (S_ISLNK(inode
->i_mode
) &&
4886 !ext4_inode_is_fast_symlink(inode
)))
4887 /* Validate extent which is part of inode */
4888 ret
= ext4_ext_check_inode(inode
);
4889 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4890 (S_ISLNK(inode
->i_mode
) &&
4891 !ext4_inode_is_fast_symlink(inode
))) {
4892 /* Validate block references which are part of inode */
4893 ret
= ext4_check_inode_blockref(inode
);
4898 if (S_ISREG(inode
->i_mode
)) {
4899 inode
->i_op
= &ext4_file_inode_operations
;
4900 inode
->i_fop
= &ext4_file_operations
;
4901 ext4_set_aops(inode
);
4902 } else if (S_ISDIR(inode
->i_mode
)) {
4903 inode
->i_op
= &ext4_dir_inode_operations
;
4904 inode
->i_fop
= &ext4_dir_operations
;
4905 } else if (S_ISLNK(inode
->i_mode
)) {
4906 if (ext4_inode_is_fast_symlink(inode
)) {
4907 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4908 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4909 sizeof(ei
->i_data
) - 1);
4911 inode
->i_op
= &ext4_symlink_inode_operations
;
4912 ext4_set_aops(inode
);
4914 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
4915 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
4916 inode
->i_op
= &ext4_special_inode_operations
;
4917 if (raw_inode
->i_block
[0])
4918 init_special_inode(inode
, inode
->i_mode
,
4919 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4921 init_special_inode(inode
, inode
->i_mode
,
4922 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4925 ext4_error(inode
->i_sb
, __func__
,
4926 "bogus i_mode (%o) for inode=%lu",
4927 inode
->i_mode
, inode
->i_ino
);
4931 ext4_set_inode_flags(inode
);
4932 unlock_new_inode(inode
);
4938 return ERR_PTR(ret
);
4941 static int ext4_inode_blocks_set(handle_t
*handle
,
4942 struct ext4_inode
*raw_inode
,
4943 struct ext4_inode_info
*ei
)
4945 struct inode
*inode
= &(ei
->vfs_inode
);
4946 u64 i_blocks
= inode
->i_blocks
;
4947 struct super_block
*sb
= inode
->i_sb
;
4949 if (i_blocks
<= ~0U) {
4951 * i_blocks can be represnted in a 32 bit variable
4952 * as multiple of 512 bytes
4954 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4955 raw_inode
->i_blocks_high
= 0;
4956 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4959 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
4962 if (i_blocks
<= 0xffffffffffffULL
) {
4964 * i_blocks can be represented in a 48 bit variable
4965 * as multiple of 512 bytes
4967 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4968 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4969 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4971 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
4972 /* i_block is stored in file system block size */
4973 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
4974 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4975 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4981 * Post the struct inode info into an on-disk inode location in the
4982 * buffer-cache. This gobbles the caller's reference to the
4983 * buffer_head in the inode location struct.
4985 * The caller must have write access to iloc->bh.
4987 static int ext4_do_update_inode(handle_t
*handle
,
4988 struct inode
*inode
,
4989 struct ext4_iloc
*iloc
)
4991 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
4992 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4993 struct buffer_head
*bh
= iloc
->bh
;
4994 int err
= 0, rc
, block
;
4996 /* For fields not not tracking in the in-memory inode,
4997 * initialise them to zero for new inodes. */
4998 if (ei
->i_state
& EXT4_STATE_NEW
)
4999 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
5001 ext4_get_inode_flags(ei
);
5002 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
5003 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5004 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
5005 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
5007 * Fix up interoperability with old kernels. Otherwise, old inodes get
5008 * re-used with the upper 16 bits of the uid/gid intact
5011 raw_inode
->i_uid_high
=
5012 cpu_to_le16(high_16_bits(inode
->i_uid
));
5013 raw_inode
->i_gid_high
=
5014 cpu_to_le16(high_16_bits(inode
->i_gid
));
5016 raw_inode
->i_uid_high
= 0;
5017 raw_inode
->i_gid_high
= 0;
5020 raw_inode
->i_uid_low
=
5021 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
5022 raw_inode
->i_gid_low
=
5023 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
5024 raw_inode
->i_uid_high
= 0;
5025 raw_inode
->i_gid_high
= 0;
5027 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
5029 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
5030 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
5031 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
5032 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
5034 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
5036 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
5037 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
);
5038 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
5039 cpu_to_le32(EXT4_OS_HURD
))
5040 raw_inode
->i_file_acl_high
=
5041 cpu_to_le16(ei
->i_file_acl
>> 32);
5042 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
5043 ext4_isize_set(raw_inode
, ei
->i_disksize
);
5044 if (ei
->i_disksize
> 0x7fffffffULL
) {
5045 struct super_block
*sb
= inode
->i_sb
;
5046 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
5047 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
5048 EXT4_SB(sb
)->s_es
->s_rev_level
==
5049 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
5050 /* If this is the first large file
5051 * created, add a flag to the superblock.
5053 err
= ext4_journal_get_write_access(handle
,
5054 EXT4_SB(sb
)->s_sbh
);
5057 ext4_update_dynamic_rev(sb
);
5058 EXT4_SET_RO_COMPAT_FEATURE(sb
,
5059 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
5061 ext4_handle_sync(handle
);
5062 err
= ext4_handle_dirty_metadata(handle
, inode
,
5063 EXT4_SB(sb
)->s_sbh
);
5066 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
5067 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
5068 if (old_valid_dev(inode
->i_rdev
)) {
5069 raw_inode
->i_block
[0] =
5070 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
5071 raw_inode
->i_block
[1] = 0;
5073 raw_inode
->i_block
[0] = 0;
5074 raw_inode
->i_block
[1] =
5075 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
5076 raw_inode
->i_block
[2] = 0;
5079 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5080 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
5082 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
5083 if (ei
->i_extra_isize
) {
5084 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5085 raw_inode
->i_version_hi
=
5086 cpu_to_le32(inode
->i_version
>> 32);
5087 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
5090 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
5091 rc
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
5094 ei
->i_state
&= ~EXT4_STATE_NEW
;
5096 ext4_update_inode_fsync_trans(handle
, inode
, 0);
5099 ext4_std_error(inode
->i_sb
, err
);
5104 * ext4_write_inode()
5106 * We are called from a few places:
5108 * - Within generic_file_write() for O_SYNC files.
5109 * Here, there will be no transaction running. We wait for any running
5110 * trasnaction to commit.
5112 * - Within sys_sync(), kupdate and such.
5113 * We wait on commit, if tol to.
5115 * - Within prune_icache() (PF_MEMALLOC == true)
5116 * Here we simply return. We can't afford to block kswapd on the
5119 * In all cases it is actually safe for us to return without doing anything,
5120 * because the inode has been copied into a raw inode buffer in
5121 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5124 * Note that we are absolutely dependent upon all inode dirtiers doing the
5125 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5126 * which we are interested.
5128 * It would be a bug for them to not do this. The code:
5130 * mark_inode_dirty(inode)
5132 * inode->i_size = expr;
5134 * is in error because a kswapd-driven write_inode() could occur while
5135 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5136 * will no longer be on the superblock's dirty inode list.
5138 int ext4_write_inode(struct inode
*inode
, int wait
)
5142 if (current
->flags
& PF_MEMALLOC
)
5145 if (EXT4_SB(inode
->i_sb
)->s_journal
) {
5146 if (ext4_journal_current_handle()) {
5147 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5155 err
= ext4_force_commit(inode
->i_sb
);
5157 struct ext4_iloc iloc
;
5159 err
= ext4_get_inode_loc(inode
, &iloc
);
5163 sync_dirty_buffer(iloc
.bh
);
5164 if (buffer_req(iloc
.bh
) && !buffer_uptodate(iloc
.bh
)) {
5165 ext4_error(inode
->i_sb
, __func__
,
5166 "IO error syncing inode, "
5167 "inode=%lu, block=%llu",
5169 (unsigned long long)iloc
.bh
->b_blocknr
);
5179 * Called from notify_change.
5181 * We want to trap VFS attempts to truncate the file as soon as
5182 * possible. In particular, we want to make sure that when the VFS
5183 * shrinks i_size, we put the inode on the orphan list and modify
5184 * i_disksize immediately, so that during the subsequent flushing of
5185 * dirty pages and freeing of disk blocks, we can guarantee that any
5186 * commit will leave the blocks being flushed in an unused state on
5187 * disk. (On recovery, the inode will get truncated and the blocks will
5188 * be freed, so we have a strong guarantee that no future commit will
5189 * leave these blocks visible to the user.)
5191 * Another thing we have to assure is that if we are in ordered mode
5192 * and inode is still attached to the committing transaction, we must
5193 * we start writeout of all the dirty pages which are being truncated.
5194 * This way we are sure that all the data written in the previous
5195 * transaction are already on disk (truncate waits for pages under
5198 * Called with inode->i_mutex down.
5200 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
5202 struct inode
*inode
= dentry
->d_inode
;
5204 const unsigned int ia_valid
= attr
->ia_valid
;
5206 error
= inode_change_ok(inode
, attr
);
5210 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
5211 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
5214 /* (user+group)*(old+new) structure, inode write (sb,
5215 * inode block, ? - but truncate inode update has it) */
5216 handle
= ext4_journal_start(inode
, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode
->i_sb
)+
5217 EXT4_MAXQUOTAS_DEL_BLOCKS(inode
->i_sb
))+3);
5218 if (IS_ERR(handle
)) {
5219 error
= PTR_ERR(handle
);
5222 error
= vfs_dq_transfer(inode
, attr
) ? -EDQUOT
: 0;
5224 ext4_journal_stop(handle
);
5227 /* Update corresponding info in inode so that everything is in
5228 * one transaction */
5229 if (attr
->ia_valid
& ATTR_UID
)
5230 inode
->i_uid
= attr
->ia_uid
;
5231 if (attr
->ia_valid
& ATTR_GID
)
5232 inode
->i_gid
= attr
->ia_gid
;
5233 error
= ext4_mark_inode_dirty(handle
, inode
);
5234 ext4_journal_stop(handle
);
5237 if (attr
->ia_valid
& ATTR_SIZE
) {
5238 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
5239 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5241 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
5248 if (S_ISREG(inode
->i_mode
) &&
5249 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
5252 handle
= ext4_journal_start(inode
, 3);
5253 if (IS_ERR(handle
)) {
5254 error
= PTR_ERR(handle
);
5258 error
= ext4_orphan_add(handle
, inode
);
5259 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
5260 rc
= ext4_mark_inode_dirty(handle
, inode
);
5263 ext4_journal_stop(handle
);
5265 if (ext4_should_order_data(inode
)) {
5266 error
= ext4_begin_ordered_truncate(inode
,
5269 /* Do as much error cleanup as possible */
5270 handle
= ext4_journal_start(inode
, 3);
5271 if (IS_ERR(handle
)) {
5272 ext4_orphan_del(NULL
, inode
);
5275 ext4_orphan_del(handle
, inode
);
5276 ext4_journal_stop(handle
);
5282 rc
= inode_setattr(inode
, attr
);
5284 /* If inode_setattr's call to ext4_truncate failed to get a
5285 * transaction handle at all, we need to clean up the in-core
5286 * orphan list manually. */
5288 ext4_orphan_del(NULL
, inode
);
5290 if (!rc
&& (ia_valid
& ATTR_MODE
))
5291 rc
= ext4_acl_chmod(inode
);
5294 ext4_std_error(inode
->i_sb
, error
);
5300 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
5303 struct inode
*inode
;
5304 unsigned long delalloc_blocks
;
5306 inode
= dentry
->d_inode
;
5307 generic_fillattr(inode
, stat
);
5310 * We can't update i_blocks if the block allocation is delayed
5311 * otherwise in the case of system crash before the real block
5312 * allocation is done, we will have i_blocks inconsistent with
5313 * on-disk file blocks.
5314 * We always keep i_blocks updated together with real
5315 * allocation. But to not confuse with user, stat
5316 * will return the blocks that include the delayed allocation
5317 * blocks for this file.
5319 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
5320 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
5321 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
5323 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
5327 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
5332 /* if nrblocks are contiguous */
5335 * With N contiguous data blocks, it need at most
5336 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5337 * 2 dindirect blocks
5340 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
5341 return indirects
+ 3;
5344 * if nrblocks are not contiguous, worse case, each block touch
5345 * a indirect block, and each indirect block touch a double indirect
5346 * block, plus a triple indirect block
5348 indirects
= nrblocks
* 2 + 1;
5352 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5354 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
5355 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
5356 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
5360 * Account for index blocks, block groups bitmaps and block group
5361 * descriptor blocks if modify datablocks and index blocks
5362 * worse case, the indexs blocks spread over different block groups
5364 * If datablocks are discontiguous, they are possible to spread over
5365 * different block groups too. If they are contiuguous, with flexbg,
5366 * they could still across block group boundary.
5368 * Also account for superblock, inode, quota and xattr blocks
5370 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5372 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
5378 * How many index blocks need to touch to modify nrblocks?
5379 * The "Chunk" flag indicating whether the nrblocks is
5380 * physically contiguous on disk
5382 * For Direct IO and fallocate, they calls get_block to allocate
5383 * one single extent at a time, so they could set the "Chunk" flag
5385 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
5390 * Now let's see how many group bitmaps and group descriptors need
5400 if (groups
> ngroups
)
5402 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
5403 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
5405 /* bitmaps and block group descriptor blocks */
5406 ret
+= groups
+ gdpblocks
;
5408 /* Blocks for super block, inode, quota and xattr blocks */
5409 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
5415 * Calulate the total number of credits to reserve to fit
5416 * the modification of a single pages into a single transaction,
5417 * which may include multiple chunks of block allocations.
5419 * This could be called via ext4_write_begin()
5421 * We need to consider the worse case, when
5422 * one new block per extent.
5424 int ext4_writepage_trans_blocks(struct inode
*inode
)
5426 int bpp
= ext4_journal_blocks_per_page(inode
);
5429 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
5431 /* Account for data blocks for journalled mode */
5432 if (ext4_should_journal_data(inode
))
5438 * Calculate the journal credits for a chunk of data modification.
5440 * This is called from DIO, fallocate or whoever calling
5441 * ext4_get_blocks() to map/allocate a chunk of contiguous disk blocks.
5443 * journal buffers for data blocks are not included here, as DIO
5444 * and fallocate do no need to journal data buffers.
5446 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
5448 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
5452 * The caller must have previously called ext4_reserve_inode_write().
5453 * Give this, we know that the caller already has write access to iloc->bh.
5455 int ext4_mark_iloc_dirty(handle_t
*handle
,
5456 struct inode
*inode
, struct ext4_iloc
*iloc
)
5460 if (test_opt(inode
->i_sb
, I_VERSION
))
5461 inode_inc_iversion(inode
);
5463 /* the do_update_inode consumes one bh->b_count */
5466 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5467 err
= ext4_do_update_inode(handle
, inode
, iloc
);
5473 * On success, We end up with an outstanding reference count against
5474 * iloc->bh. This _must_ be cleaned up later.
5478 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
5479 struct ext4_iloc
*iloc
)
5483 err
= ext4_get_inode_loc(inode
, iloc
);
5485 BUFFER_TRACE(iloc
->bh
, "get_write_access");
5486 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
5492 ext4_std_error(inode
->i_sb
, err
);
5497 * Expand an inode by new_extra_isize bytes.
5498 * Returns 0 on success or negative error number on failure.
5500 static int ext4_expand_extra_isize(struct inode
*inode
,
5501 unsigned int new_extra_isize
,
5502 struct ext4_iloc iloc
,
5505 struct ext4_inode
*raw_inode
;
5506 struct ext4_xattr_ibody_header
*header
;
5507 struct ext4_xattr_entry
*entry
;
5509 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
5512 raw_inode
= ext4_raw_inode(&iloc
);
5514 header
= IHDR(inode
, raw_inode
);
5515 entry
= IFIRST(header
);
5517 /* No extended attributes present */
5518 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
5519 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
5520 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5522 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5526 /* try to expand with EAs present */
5527 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5532 * What we do here is to mark the in-core inode as clean with respect to inode
5533 * dirtiness (it may still be data-dirty).
5534 * This means that the in-core inode may be reaped by prune_icache
5535 * without having to perform any I/O. This is a very good thing,
5536 * because *any* task may call prune_icache - even ones which
5537 * have a transaction open against a different journal.
5539 * Is this cheating? Not really. Sure, we haven't written the
5540 * inode out, but prune_icache isn't a user-visible syncing function.
5541 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5542 * we start and wait on commits.
5544 * Is this efficient/effective? Well, we're being nice to the system
5545 * by cleaning up our inodes proactively so they can be reaped
5546 * without I/O. But we are potentially leaving up to five seconds'
5547 * worth of inodes floating about which prune_icache wants us to
5548 * write out. One way to fix that would be to get prune_icache()
5549 * to do a write_super() to free up some memory. It has the desired
5552 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5554 struct ext4_iloc iloc
;
5555 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5556 static unsigned int mnt_count
;
5560 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5561 if (ext4_handle_valid(handle
) &&
5562 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5563 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
5565 * We need extra buffer credits since we may write into EA block
5566 * with this same handle. If journal_extend fails, then it will
5567 * only result in a minor loss of functionality for that inode.
5568 * If this is felt to be critical, then e2fsck should be run to
5569 * force a large enough s_min_extra_isize.
5571 if ((jbd2_journal_extend(handle
,
5572 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5573 ret
= ext4_expand_extra_isize(inode
,
5574 sbi
->s_want_extra_isize
,
5577 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
5579 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5580 ext4_warning(inode
->i_sb
, __func__
,
5581 "Unable to expand inode %lu. Delete"
5582 " some EAs or run e2fsck.",
5585 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5591 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5596 * ext4_dirty_inode() is called from __mark_inode_dirty()
5598 * We're really interested in the case where a file is being extended.
5599 * i_size has been changed by generic_commit_write() and we thus need
5600 * to include the updated inode in the current transaction.
5602 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
5603 * are allocated to the file.
5605 * If the inode is marked synchronous, we don't honour that here - doing
5606 * so would cause a commit on atime updates, which we don't bother doing.
5607 * We handle synchronous inodes at the highest possible level.
5609 void ext4_dirty_inode(struct inode
*inode
)
5613 handle
= ext4_journal_start(inode
, 2);
5617 ext4_mark_inode_dirty(handle
, inode
);
5619 ext4_journal_stop(handle
);
5626 * Bind an inode's backing buffer_head into this transaction, to prevent
5627 * it from being flushed to disk early. Unlike
5628 * ext4_reserve_inode_write, this leaves behind no bh reference and
5629 * returns no iloc structure, so the caller needs to repeat the iloc
5630 * lookup to mark the inode dirty later.
5632 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5634 struct ext4_iloc iloc
;
5638 err
= ext4_get_inode_loc(inode
, &iloc
);
5640 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5641 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5643 err
= ext4_handle_dirty_metadata(handle
,
5649 ext4_std_error(inode
->i_sb
, err
);
5654 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5661 * We have to be very careful here: changing a data block's
5662 * journaling status dynamically is dangerous. If we write a
5663 * data block to the journal, change the status and then delete
5664 * that block, we risk forgetting to revoke the old log record
5665 * from the journal and so a subsequent replay can corrupt data.
5666 * So, first we make sure that the journal is empty and that
5667 * nobody is changing anything.
5670 journal
= EXT4_JOURNAL(inode
);
5673 if (is_journal_aborted(journal
))
5676 jbd2_journal_lock_updates(journal
);
5677 jbd2_journal_flush(journal
);
5680 * OK, there are no updates running now, and all cached data is
5681 * synced to disk. We are now in a completely consistent state
5682 * which doesn't have anything in the journal, and we know that
5683 * no filesystem updates are running, so it is safe to modify
5684 * the inode's in-core data-journaling state flag now.
5688 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
5690 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
5691 ext4_set_aops(inode
);
5693 jbd2_journal_unlock_updates(journal
);
5695 /* Finally we can mark the inode as dirty. */
5697 handle
= ext4_journal_start(inode
, 1);
5699 return PTR_ERR(handle
);
5701 err
= ext4_mark_inode_dirty(handle
, inode
);
5702 ext4_handle_sync(handle
);
5703 ext4_journal_stop(handle
);
5704 ext4_std_error(inode
->i_sb
, err
);
5709 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5711 return !buffer_mapped(bh
);
5714 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5716 struct page
*page
= vmf
->page
;
5721 struct file
*file
= vma
->vm_file
;
5722 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5723 struct address_space
*mapping
= inode
->i_mapping
;
5726 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5727 * get i_mutex because we are already holding mmap_sem.
5729 down_read(&inode
->i_alloc_sem
);
5730 size
= i_size_read(inode
);
5731 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5732 || !PageUptodate(page
)) {
5733 /* page got truncated from under us? */
5737 if (PageMappedToDisk(page
))
5740 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5741 len
= size
& ~PAGE_CACHE_MASK
;
5743 len
= PAGE_CACHE_SIZE
;
5747 * return if we have all the buffers mapped. This avoid
5748 * the need to call write_begin/write_end which does a
5749 * journal_start/journal_stop which can block and take
5752 if (page_has_buffers(page
)) {
5753 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5754 ext4_bh_unmapped
)) {
5761 * OK, we need to fill the hole... Do write_begin write_end
5762 * to do block allocation/reservation.We are not holding
5763 * inode.i__mutex here. That allow * parallel write_begin,
5764 * write_end call. lock_page prevent this from happening
5765 * on the same page though
5767 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5768 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5771 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5772 len
, len
, page
, fsdata
);
5778 ret
= VM_FAULT_SIGBUS
;
5779 up_read(&inode
->i_alloc_sem
);