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
;
1014 * Calculate the number of metadata blocks need to reserve
1015 * to allocate a new block at @lblocks for non extent file based file
1017 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
,
1020 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1021 int dind_mask
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
) - 1;
1024 if (lblock
< EXT4_NDIR_BLOCKS
)
1027 lblock
-= EXT4_NDIR_BLOCKS
;
1029 if (ei
->i_da_metadata_calc_len
&&
1030 (lblock
& dind_mask
) == ei
->i_da_metadata_calc_last_lblock
) {
1031 ei
->i_da_metadata_calc_len
++;
1034 ei
->i_da_metadata_calc_last_lblock
= lblock
& dind_mask
;
1035 ei
->i_da_metadata_calc_len
= 1;
1036 blk_bits
= roundup_pow_of_two(lblock
+ 1);
1037 return (blk_bits
/ EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
)) + 1;
1041 * Calculate the number of metadata blocks need to reserve
1042 * to allocate a block located at @lblock
1044 static int ext4_calc_metadata_amount(struct inode
*inode
, sector_t lblock
)
1046 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
1047 return ext4_ext_calc_metadata_amount(inode
, lblock
);
1049 return ext4_indirect_calc_metadata_amount(inode
, lblock
);
1053 * Called with i_data_sem down, which is important since we can call
1054 * ext4_discard_preallocations() from here.
1056 void ext4_da_update_reserve_space(struct inode
*inode
,
1057 int used
, int quota_claim
)
1059 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1060 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1061 int mdb_free
= 0, allocated_meta_blocks
= 0;
1063 spin_lock(&ei
->i_block_reservation_lock
);
1064 if (unlikely(used
> ei
->i_reserved_data_blocks
)) {
1065 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "%s: ino %lu, used %d "
1066 "with only %d reserved data blocks\n",
1067 __func__
, inode
->i_ino
, used
,
1068 ei
->i_reserved_data_blocks
);
1070 used
= ei
->i_reserved_data_blocks
;
1073 /* Update per-inode reservations */
1074 ei
->i_reserved_data_blocks
-= used
;
1075 used
+= ei
->i_allocated_meta_blocks
;
1076 ei
->i_reserved_meta_blocks
-= ei
->i_allocated_meta_blocks
;
1077 allocated_meta_blocks
= ei
->i_allocated_meta_blocks
;
1078 ei
->i_allocated_meta_blocks
= 0;
1079 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, used
);
1081 if (ei
->i_reserved_data_blocks
== 0) {
1083 * We can release all of the reserved metadata blocks
1084 * only when we have written all of the delayed
1085 * allocation blocks.
1087 mdb_free
= ei
->i_reserved_meta_blocks
;
1088 ei
->i_reserved_meta_blocks
= 0;
1089 ei
->i_da_metadata_calc_len
= 0;
1090 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1092 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1094 /* Update quota subsystem */
1096 vfs_dq_claim_block(inode
, used
);
1098 vfs_dq_release_reservation_block(inode
, mdb_free
);
1101 * We did fallocate with an offset that is already delayed
1102 * allocated. So on delayed allocated writeback we should
1103 * not update the quota for allocated blocks. But then
1104 * converting an fallocate region to initialized region would
1105 * have caused a metadata allocation. So claim quota for
1108 if (allocated_meta_blocks
)
1109 vfs_dq_claim_block(inode
, allocated_meta_blocks
);
1110 vfs_dq_release_reservation_block(inode
, mdb_free
+ used
);
1114 * If we have done all the pending block allocations and if
1115 * there aren't any writers on the inode, we can discard the
1116 * inode's preallocations.
1118 if ((ei
->i_reserved_data_blocks
== 0) &&
1119 (atomic_read(&inode
->i_writecount
) == 0))
1120 ext4_discard_preallocations(inode
);
1123 static int check_block_validity(struct inode
*inode
, const char *msg
,
1124 sector_t logical
, sector_t phys
, int len
)
1126 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), phys
, len
)) {
1127 ext4_error(inode
->i_sb
, msg
,
1128 "inode #%lu logical block %llu mapped to %llu "
1129 "(size %d)", inode
->i_ino
,
1130 (unsigned long long) logical
,
1131 (unsigned long long) phys
, len
);
1138 * Return the number of contiguous dirty pages in a given inode
1139 * starting at page frame idx.
1141 static pgoff_t
ext4_num_dirty_pages(struct inode
*inode
, pgoff_t idx
,
1142 unsigned int max_pages
)
1144 struct address_space
*mapping
= inode
->i_mapping
;
1146 struct pagevec pvec
;
1148 int i
, nr_pages
, done
= 0;
1152 pagevec_init(&pvec
, 0);
1155 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1156 PAGECACHE_TAG_DIRTY
,
1157 (pgoff_t
)PAGEVEC_SIZE
);
1160 for (i
= 0; i
< nr_pages
; i
++) {
1161 struct page
*page
= pvec
.pages
[i
];
1162 struct buffer_head
*bh
, *head
;
1165 if (unlikely(page
->mapping
!= mapping
) ||
1167 PageWriteback(page
) ||
1168 page
->index
!= idx
) {
1173 if (page_has_buffers(page
)) {
1174 bh
= head
= page_buffers(page
);
1176 if (!buffer_delay(bh
) &&
1177 !buffer_unwritten(bh
))
1179 bh
= bh
->b_this_page
;
1180 } while (!done
&& (bh
!= head
));
1187 if (num
>= max_pages
)
1190 pagevec_release(&pvec
);
1196 * The ext4_get_blocks() function tries to look up the requested blocks,
1197 * and returns if the blocks are already mapped.
1199 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1200 * and store the allocated blocks in the result buffer head and mark it
1203 * If file type is extents based, it will call ext4_ext_get_blocks(),
1204 * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
1207 * On success, it returns the number of blocks being mapped or allocate.
1208 * if create==0 and the blocks are pre-allocated and uninitialized block,
1209 * the result buffer head is unmapped. If the create ==1, it will make sure
1210 * the buffer head is mapped.
1212 * It returns 0 if plain look up failed (blocks have not been allocated), in
1213 * that casem, buffer head is unmapped
1215 * It returns the error in case of allocation failure.
1217 int ext4_get_blocks(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1218 unsigned int max_blocks
, struct buffer_head
*bh
,
1223 clear_buffer_mapped(bh
);
1224 clear_buffer_unwritten(bh
);
1226 ext_debug("ext4_get_blocks(): inode %lu, flag %d, max_blocks %u,"
1227 "logical block %lu\n", inode
->i_ino
, flags
, max_blocks
,
1228 (unsigned long)block
);
1230 * Try to see if we can get the block without requesting a new
1231 * file system block.
1233 down_read((&EXT4_I(inode
)->i_data_sem
));
1234 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1235 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1238 retval
= ext4_ind_get_blocks(handle
, inode
, block
, max_blocks
,
1241 up_read((&EXT4_I(inode
)->i_data_sem
));
1243 if (retval
> 0 && buffer_mapped(bh
)) {
1244 int ret
= check_block_validity(inode
, "file system corruption",
1245 block
, bh
->b_blocknr
, retval
);
1250 /* If it is only a block(s) look up */
1251 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
1255 * Returns if the blocks have already allocated
1257 * Note that if blocks have been preallocated
1258 * ext4_ext_get_block() returns th create = 0
1259 * with buffer head unmapped.
1261 if (retval
> 0 && buffer_mapped(bh
))
1265 * When we call get_blocks without the create flag, the
1266 * BH_Unwritten flag could have gotten set if the blocks
1267 * requested were part of a uninitialized extent. We need to
1268 * clear this flag now that we are committed to convert all or
1269 * part of the uninitialized extent to be an initialized
1270 * extent. This is because we need to avoid the combination
1271 * of BH_Unwritten and BH_Mapped flags being simultaneously
1272 * set on the buffer_head.
1274 clear_buffer_unwritten(bh
);
1277 * New blocks allocate and/or writing to uninitialized extent
1278 * will possibly result in updating i_data, so we take
1279 * the write lock of i_data_sem, and call get_blocks()
1280 * with create == 1 flag.
1282 down_write((&EXT4_I(inode
)->i_data_sem
));
1285 * if the caller is from delayed allocation writeout path
1286 * we have already reserved fs blocks for allocation
1287 * let the underlying get_block() function know to
1288 * avoid double accounting
1290 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1291 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1293 * We need to check for EXT4 here because migrate
1294 * could have changed the inode type in between
1296 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1297 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1300 retval
= ext4_ind_get_blocks(handle
, inode
, block
,
1301 max_blocks
, bh
, flags
);
1303 if (retval
> 0 && buffer_new(bh
)) {
1305 * We allocated new blocks which will result in
1306 * i_data's format changing. Force the migrate
1307 * to fail by clearing migrate flags
1309 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_EXT_MIGRATE
;
1313 * Update reserved blocks/metadata blocks after successful
1314 * block allocation which had been deferred till now. We don't
1315 * support fallocate for non extent files. So we can update
1316 * reserve space here.
1319 (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
))
1320 ext4_da_update_reserve_space(inode
, retval
, 1);
1322 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1323 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1325 up_write((&EXT4_I(inode
)->i_data_sem
));
1326 if (retval
> 0 && buffer_mapped(bh
)) {
1327 int ret
= check_block_validity(inode
, "file system "
1328 "corruption after allocation",
1329 block
, bh
->b_blocknr
, retval
);
1336 /* Maximum number of blocks we map for direct IO at once. */
1337 #define DIO_MAX_BLOCKS 4096
1339 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1340 struct buffer_head
*bh_result
, int create
)
1342 handle_t
*handle
= ext4_journal_current_handle();
1343 int ret
= 0, started
= 0;
1344 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1347 if (create
&& !handle
) {
1348 /* Direct IO write... */
1349 if (max_blocks
> DIO_MAX_BLOCKS
)
1350 max_blocks
= DIO_MAX_BLOCKS
;
1351 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1352 handle
= ext4_journal_start(inode
, dio_credits
);
1353 if (IS_ERR(handle
)) {
1354 ret
= PTR_ERR(handle
);
1360 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
1361 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1363 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1367 ext4_journal_stop(handle
);
1373 * `handle' can be NULL if create is zero
1375 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1376 ext4_lblk_t block
, int create
, int *errp
)
1378 struct buffer_head dummy
;
1382 J_ASSERT(handle
!= NULL
|| create
== 0);
1385 dummy
.b_blocknr
= -1000;
1386 buffer_trace_init(&dummy
.b_history
);
1388 flags
|= EXT4_GET_BLOCKS_CREATE
;
1389 err
= ext4_get_blocks(handle
, inode
, block
, 1, &dummy
, flags
);
1391 * ext4_get_blocks() returns number of blocks mapped. 0 in
1400 if (!err
&& buffer_mapped(&dummy
)) {
1401 struct buffer_head
*bh
;
1402 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1407 if (buffer_new(&dummy
)) {
1408 J_ASSERT(create
!= 0);
1409 J_ASSERT(handle
!= NULL
);
1412 * Now that we do not always journal data, we should
1413 * keep in mind whether this should always journal the
1414 * new buffer as metadata. For now, regular file
1415 * writes use ext4_get_block instead, so it's not a
1419 BUFFER_TRACE(bh
, "call get_create_access");
1420 fatal
= ext4_journal_get_create_access(handle
, bh
);
1421 if (!fatal
&& !buffer_uptodate(bh
)) {
1422 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1423 set_buffer_uptodate(bh
);
1426 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1427 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1431 BUFFER_TRACE(bh
, "not a new buffer");
1444 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1445 ext4_lblk_t block
, int create
, int *err
)
1447 struct buffer_head
*bh
;
1449 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1452 if (buffer_uptodate(bh
))
1454 ll_rw_block(READ_META
, 1, &bh
);
1456 if (buffer_uptodate(bh
))
1463 static int walk_page_buffers(handle_t
*handle
,
1464 struct buffer_head
*head
,
1468 int (*fn
)(handle_t
*handle
,
1469 struct buffer_head
*bh
))
1471 struct buffer_head
*bh
;
1472 unsigned block_start
, block_end
;
1473 unsigned blocksize
= head
->b_size
;
1475 struct buffer_head
*next
;
1477 for (bh
= head
, block_start
= 0;
1478 ret
== 0 && (bh
!= head
|| !block_start
);
1479 block_start
= block_end
, bh
= next
) {
1480 next
= bh
->b_this_page
;
1481 block_end
= block_start
+ blocksize
;
1482 if (block_end
<= from
|| block_start
>= to
) {
1483 if (partial
&& !buffer_uptodate(bh
))
1487 err
= (*fn
)(handle
, bh
);
1495 * To preserve ordering, it is essential that the hole instantiation and
1496 * the data write be encapsulated in a single transaction. We cannot
1497 * close off a transaction and start a new one between the ext4_get_block()
1498 * and the commit_write(). So doing the jbd2_journal_start at the start of
1499 * prepare_write() is the right place.
1501 * Also, this function can nest inside ext4_writepage() ->
1502 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1503 * has generated enough buffer credits to do the whole page. So we won't
1504 * block on the journal in that case, which is good, because the caller may
1507 * By accident, ext4 can be reentered when a transaction is open via
1508 * quota file writes. If we were to commit the transaction while thus
1509 * reentered, there can be a deadlock - we would be holding a quota
1510 * lock, and the commit would never complete if another thread had a
1511 * transaction open and was blocking on the quota lock - a ranking
1514 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1515 * will _not_ run commit under these circumstances because handle->h_ref
1516 * is elevated. We'll still have enough credits for the tiny quotafile
1519 static int do_journal_get_write_access(handle_t
*handle
,
1520 struct buffer_head
*bh
)
1522 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1524 return ext4_journal_get_write_access(handle
, bh
);
1528 * Truncate blocks that were not used by write. We have to truncate the
1529 * pagecache as well so that corresponding buffers get properly unmapped.
1531 static void ext4_truncate_failed_write(struct inode
*inode
)
1533 truncate_inode_pages(inode
->i_mapping
, inode
->i_size
);
1534 ext4_truncate(inode
);
1537 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1538 loff_t pos
, unsigned len
, unsigned flags
,
1539 struct page
**pagep
, void **fsdata
)
1541 struct inode
*inode
= mapping
->host
;
1542 int ret
, needed_blocks
;
1549 trace_ext4_write_begin(inode
, pos
, len
, flags
);
1551 * Reserve one block more for addition to orphan list in case
1552 * we allocate blocks but write fails for some reason
1554 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
1555 index
= pos
>> PAGE_CACHE_SHIFT
;
1556 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1560 handle
= ext4_journal_start(inode
, needed_blocks
);
1561 if (IS_ERR(handle
)) {
1562 ret
= PTR_ERR(handle
);
1566 /* We cannot recurse into the filesystem as the transaction is already
1568 flags
|= AOP_FLAG_NOFS
;
1570 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1572 ext4_journal_stop(handle
);
1578 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1581 if (!ret
&& ext4_should_journal_data(inode
)) {
1582 ret
= walk_page_buffers(handle
, page_buffers(page
),
1583 from
, to
, NULL
, do_journal_get_write_access
);
1588 page_cache_release(page
);
1590 * block_write_begin may have instantiated a few blocks
1591 * outside i_size. Trim these off again. Don't need
1592 * i_size_read because we hold i_mutex.
1594 * Add inode to orphan list in case we crash before
1597 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1598 ext4_orphan_add(handle
, inode
);
1600 ext4_journal_stop(handle
);
1601 if (pos
+ len
> inode
->i_size
) {
1602 ext4_truncate_failed_write(inode
);
1604 * If truncate failed early the inode might
1605 * still be on the orphan list; we need to
1606 * make sure the inode is removed from the
1607 * orphan list in that case.
1610 ext4_orphan_del(NULL
, inode
);
1614 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1620 /* For write_end() in data=journal mode */
1621 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1623 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1625 set_buffer_uptodate(bh
);
1626 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1629 static int ext4_generic_write_end(struct file
*file
,
1630 struct address_space
*mapping
,
1631 loff_t pos
, unsigned len
, unsigned copied
,
1632 struct page
*page
, void *fsdata
)
1634 int i_size_changed
= 0;
1635 struct inode
*inode
= mapping
->host
;
1636 handle_t
*handle
= ext4_journal_current_handle();
1638 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1641 * No need to use i_size_read() here, the i_size
1642 * cannot change under us because we hold i_mutex.
1644 * But it's important to update i_size while still holding page lock:
1645 * page writeout could otherwise come in and zero beyond i_size.
1647 if (pos
+ copied
> inode
->i_size
) {
1648 i_size_write(inode
, pos
+ copied
);
1652 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
1653 /* We need to mark inode dirty even if
1654 * new_i_size is less that inode->i_size
1655 * bu greater than i_disksize.(hint delalloc)
1657 ext4_update_i_disksize(inode
, (pos
+ copied
));
1661 page_cache_release(page
);
1664 * Don't mark the inode dirty under page lock. First, it unnecessarily
1665 * makes the holding time of page lock longer. Second, it forces lock
1666 * ordering of page lock and transaction start for journaling
1670 ext4_mark_inode_dirty(handle
, inode
);
1676 * We need to pick up the new inode size which generic_commit_write gave us
1677 * `file' can be NULL - eg, when called from page_symlink().
1679 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1680 * buffers are managed internally.
1682 static int ext4_ordered_write_end(struct file
*file
,
1683 struct address_space
*mapping
,
1684 loff_t pos
, unsigned len
, unsigned copied
,
1685 struct page
*page
, void *fsdata
)
1687 handle_t
*handle
= ext4_journal_current_handle();
1688 struct inode
*inode
= mapping
->host
;
1691 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
1692 ret
= ext4_jbd2_file_inode(handle
, inode
);
1695 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1698 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1699 /* if we have allocated more blocks and copied
1700 * less. We will have blocks allocated outside
1701 * inode->i_size. So truncate them
1703 ext4_orphan_add(handle
, inode
);
1707 ret2
= ext4_journal_stop(handle
);
1711 if (pos
+ len
> inode
->i_size
) {
1712 ext4_truncate_failed_write(inode
);
1714 * If truncate failed early the inode might still be
1715 * on the orphan list; we need to make sure the inode
1716 * is removed from the orphan list in that case.
1719 ext4_orphan_del(NULL
, inode
);
1723 return ret
? ret
: copied
;
1726 static int ext4_writeback_write_end(struct file
*file
,
1727 struct address_space
*mapping
,
1728 loff_t pos
, unsigned len
, unsigned copied
,
1729 struct page
*page
, void *fsdata
)
1731 handle_t
*handle
= ext4_journal_current_handle();
1732 struct inode
*inode
= mapping
->host
;
1735 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1736 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1739 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1740 /* if we have allocated more blocks and copied
1741 * less. We will have blocks allocated outside
1742 * inode->i_size. So truncate them
1744 ext4_orphan_add(handle
, inode
);
1749 ret2
= ext4_journal_stop(handle
);
1753 if (pos
+ len
> inode
->i_size
) {
1754 ext4_truncate_failed_write(inode
);
1756 * If truncate failed early the inode might still be
1757 * on the orphan list; we need to make sure the inode
1758 * is removed from the orphan list in that case.
1761 ext4_orphan_del(NULL
, inode
);
1764 return ret
? ret
: copied
;
1767 static int ext4_journalled_write_end(struct file
*file
,
1768 struct address_space
*mapping
,
1769 loff_t pos
, unsigned len
, unsigned copied
,
1770 struct page
*page
, void *fsdata
)
1772 handle_t
*handle
= ext4_journal_current_handle();
1773 struct inode
*inode
= mapping
->host
;
1779 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1780 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1784 if (!PageUptodate(page
))
1786 page_zero_new_buffers(page
, from
+copied
, to
);
1789 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1790 to
, &partial
, write_end_fn
);
1792 SetPageUptodate(page
);
1793 new_i_size
= pos
+ copied
;
1794 if (new_i_size
> inode
->i_size
)
1795 i_size_write(inode
, pos
+copied
);
1796 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1797 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1798 ext4_update_i_disksize(inode
, new_i_size
);
1799 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1805 page_cache_release(page
);
1806 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1807 /* if we have allocated more blocks and copied
1808 * less. We will have blocks allocated outside
1809 * inode->i_size. So truncate them
1811 ext4_orphan_add(handle
, inode
);
1813 ret2
= ext4_journal_stop(handle
);
1816 if (pos
+ len
> inode
->i_size
) {
1817 ext4_truncate_failed_write(inode
);
1819 * If truncate failed early the inode might still be
1820 * on the orphan list; we need to make sure the inode
1821 * is removed from the orphan list in that case.
1824 ext4_orphan_del(NULL
, inode
);
1827 return ret
? ret
: copied
;
1831 * Reserve a single block located at lblock
1833 static int ext4_da_reserve_space(struct inode
*inode
, sector_t lblock
)
1836 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1837 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1838 unsigned long md_needed
, md_reserved
;
1841 * recalculate the amount of metadata blocks to reserve
1842 * in order to allocate nrblocks
1843 * worse case is one extent per block
1846 spin_lock(&ei
->i_block_reservation_lock
);
1847 md_reserved
= ei
->i_reserved_meta_blocks
;
1848 md_needed
= ext4_calc_metadata_amount(inode
, lblock
);
1849 spin_unlock(&ei
->i_block_reservation_lock
);
1852 * Make quota reservation here to prevent quota overflow
1853 * later. Real quota accounting is done at pages writeout
1856 if (vfs_dq_reserve_block(inode
, md_needed
+ 1))
1859 if (ext4_claim_free_blocks(sbi
, md_needed
+ 1)) {
1860 vfs_dq_release_reservation_block(inode
, md_needed
+ 1);
1861 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1867 spin_lock(&ei
->i_block_reservation_lock
);
1868 ei
->i_reserved_data_blocks
++;
1869 ei
->i_reserved_meta_blocks
+= md_needed
;
1870 spin_unlock(&ei
->i_block_reservation_lock
);
1872 return 0; /* success */
1875 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1877 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1878 struct ext4_inode_info
*ei
= EXT4_I(inode
);
1881 return; /* Nothing to release, exit */
1883 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1885 if (unlikely(to_free
> ei
->i_reserved_data_blocks
)) {
1887 * if there aren't enough reserved blocks, then the
1888 * counter is messed up somewhere. Since this
1889 * function is called from invalidate page, it's
1890 * harmless to return without any action.
1892 ext4_msg(inode
->i_sb
, KERN_NOTICE
, "ext4_da_release_space: "
1893 "ino %lu, to_free %d with only %d reserved "
1894 "data blocks\n", inode
->i_ino
, to_free
,
1895 ei
->i_reserved_data_blocks
);
1897 to_free
= ei
->i_reserved_data_blocks
;
1899 ei
->i_reserved_data_blocks
-= to_free
;
1901 if (ei
->i_reserved_data_blocks
== 0) {
1903 * We can release all of the reserved metadata blocks
1904 * only when we have written all of the delayed
1905 * allocation blocks.
1907 to_free
+= ei
->i_reserved_meta_blocks
;
1908 ei
->i_reserved_meta_blocks
= 0;
1909 ei
->i_da_metadata_calc_len
= 0;
1912 /* update fs dirty blocks counter */
1913 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, to_free
);
1915 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1917 vfs_dq_release_reservation_block(inode
, to_free
);
1920 static void ext4_da_page_release_reservation(struct page
*page
,
1921 unsigned long offset
)
1924 struct buffer_head
*head
, *bh
;
1925 unsigned int curr_off
= 0;
1927 head
= page_buffers(page
);
1930 unsigned int next_off
= curr_off
+ bh
->b_size
;
1932 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1934 clear_buffer_delay(bh
);
1936 curr_off
= next_off
;
1937 } while ((bh
= bh
->b_this_page
) != head
);
1938 ext4_da_release_space(page
->mapping
->host
, to_release
);
1942 * Delayed allocation stuff
1946 * mpage_da_submit_io - walks through extent of pages and try to write
1947 * them with writepage() call back
1949 * @mpd->inode: inode
1950 * @mpd->first_page: first page of the extent
1951 * @mpd->next_page: page after the last page of the extent
1953 * By the time mpage_da_submit_io() is called we expect all blocks
1954 * to be allocated. this may be wrong if allocation failed.
1956 * As pages are already locked by write_cache_pages(), we can't use it
1958 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1961 struct pagevec pvec
;
1962 unsigned long index
, end
;
1963 int ret
= 0, err
, nr_pages
, i
;
1964 struct inode
*inode
= mpd
->inode
;
1965 struct address_space
*mapping
= inode
->i_mapping
;
1967 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1969 * We need to start from the first_page to the next_page - 1
1970 * to make sure we also write the mapped dirty buffer_heads.
1971 * If we look at mpd->b_blocknr we would only be looking
1972 * at the currently mapped buffer_heads.
1974 index
= mpd
->first_page
;
1975 end
= mpd
->next_page
- 1;
1977 pagevec_init(&pvec
, 0);
1978 while (index
<= end
) {
1979 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1982 for (i
= 0; i
< nr_pages
; i
++) {
1983 struct page
*page
= pvec
.pages
[i
];
1985 index
= page
->index
;
1990 BUG_ON(!PageLocked(page
));
1991 BUG_ON(PageWriteback(page
));
1993 pages_skipped
= mpd
->wbc
->pages_skipped
;
1994 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
1995 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
1997 * have successfully written the page
1998 * without skipping the same
2000 mpd
->pages_written
++;
2002 * In error case, we have to continue because
2003 * remaining pages are still locked
2004 * XXX: unlock and re-dirty them?
2009 pagevec_release(&pvec
);
2015 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
2017 * @mpd->inode - inode to walk through
2018 * @exbh->b_blocknr - first block on a disk
2019 * @exbh->b_size - amount of space in bytes
2020 * @logical - first logical block to start assignment with
2022 * the function goes through all passed space and put actual disk
2023 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
2025 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
2026 struct buffer_head
*exbh
)
2028 struct inode
*inode
= mpd
->inode
;
2029 struct address_space
*mapping
= inode
->i_mapping
;
2030 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
2031 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
2032 struct buffer_head
*head
, *bh
;
2034 struct pagevec pvec
;
2037 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2038 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2039 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2041 pagevec_init(&pvec
, 0);
2043 while (index
<= end
) {
2044 /* XXX: optimize tail */
2045 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2048 for (i
= 0; i
< nr_pages
; i
++) {
2049 struct page
*page
= pvec
.pages
[i
];
2051 index
= page
->index
;
2056 BUG_ON(!PageLocked(page
));
2057 BUG_ON(PageWriteback(page
));
2058 BUG_ON(!page_has_buffers(page
));
2060 bh
= page_buffers(page
);
2063 /* skip blocks out of the range */
2065 if (cur_logical
>= logical
)
2068 } while ((bh
= bh
->b_this_page
) != head
);
2071 if (cur_logical
>= logical
+ blocks
)
2074 if (buffer_delay(bh
) ||
2075 buffer_unwritten(bh
)) {
2077 BUG_ON(bh
->b_bdev
!= inode
->i_sb
->s_bdev
);
2079 if (buffer_delay(bh
)) {
2080 clear_buffer_delay(bh
);
2081 bh
->b_blocknr
= pblock
;
2084 * unwritten already should have
2085 * blocknr assigned. Verify that
2087 clear_buffer_unwritten(bh
);
2088 BUG_ON(bh
->b_blocknr
!= pblock
);
2091 } else if (buffer_mapped(bh
))
2092 BUG_ON(bh
->b_blocknr
!= pblock
);
2096 } while ((bh
= bh
->b_this_page
) != head
);
2098 pagevec_release(&pvec
);
2104 * __unmap_underlying_blocks - just a helper function to unmap
2105 * set of blocks described by @bh
2107 static inline void __unmap_underlying_blocks(struct inode
*inode
,
2108 struct buffer_head
*bh
)
2110 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
2113 blocks
= bh
->b_size
>> inode
->i_blkbits
;
2114 for (i
= 0; i
< blocks
; i
++)
2115 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
2118 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
2119 sector_t logical
, long blk_cnt
)
2123 struct pagevec pvec
;
2124 struct inode
*inode
= mpd
->inode
;
2125 struct address_space
*mapping
= inode
->i_mapping
;
2127 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2128 end
= (logical
+ blk_cnt
- 1) >>
2129 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2130 while (index
<= end
) {
2131 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2134 for (i
= 0; i
< nr_pages
; i
++) {
2135 struct page
*page
= pvec
.pages
[i
];
2136 index
= page
->index
;
2141 BUG_ON(!PageLocked(page
));
2142 BUG_ON(PageWriteback(page
));
2143 block_invalidatepage(page
, 0);
2144 ClearPageUptodate(page
);
2151 static void ext4_print_free_blocks(struct inode
*inode
)
2153 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2154 printk(KERN_CRIT
"Total free blocks count %lld\n",
2155 ext4_count_free_blocks(inode
->i_sb
));
2156 printk(KERN_CRIT
"Free/Dirty block details\n");
2157 printk(KERN_CRIT
"free_blocks=%lld\n",
2158 (long long) percpu_counter_sum(&sbi
->s_freeblocks_counter
));
2159 printk(KERN_CRIT
"dirty_blocks=%lld\n",
2160 (long long) percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
2161 printk(KERN_CRIT
"Block reservation details\n");
2162 printk(KERN_CRIT
"i_reserved_data_blocks=%u\n",
2163 EXT4_I(inode
)->i_reserved_data_blocks
);
2164 printk(KERN_CRIT
"i_reserved_meta_blocks=%u\n",
2165 EXT4_I(inode
)->i_reserved_meta_blocks
);
2170 * mpage_da_map_blocks - go through given space
2172 * @mpd - bh describing space
2174 * The function skips space we know is already mapped to disk blocks.
2177 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
2179 int err
, blks
, get_blocks_flags
;
2180 struct buffer_head
new;
2181 sector_t next
= mpd
->b_blocknr
;
2182 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2183 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
2184 handle_t
*handle
= NULL
;
2187 * We consider only non-mapped and non-allocated blocks
2189 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2190 !(mpd
->b_state
& (1 << BH_Delay
)) &&
2191 !(mpd
->b_state
& (1 << BH_Unwritten
)))
2195 * If we didn't accumulate anything to write simply return
2200 handle
= ext4_journal_current_handle();
2204 * Call ext4_get_blocks() to allocate any delayed allocation
2205 * blocks, or to convert an uninitialized extent to be
2206 * initialized (in the case where we have written into
2207 * one or more preallocated blocks).
2209 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2210 * indicate that we are on the delayed allocation path. This
2211 * affects functions in many different parts of the allocation
2212 * call path. This flag exists primarily because we don't
2213 * want to change *many* call functions, so ext4_get_blocks()
2214 * will set the magic i_delalloc_reserved_flag once the
2215 * inode's allocation semaphore is taken.
2217 * If the blocks in questions were delalloc blocks, set
2218 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2219 * variables are updated after the blocks have been allocated.
2222 get_blocks_flags
= EXT4_GET_BLOCKS_CREATE
;
2223 if (mpd
->b_state
& (1 << BH_Delay
))
2224 get_blocks_flags
|= EXT4_GET_BLOCKS_DELALLOC_RESERVE
;
2226 blks
= ext4_get_blocks(handle
, mpd
->inode
, next
, max_blocks
,
2227 &new, get_blocks_flags
);
2231 * If get block returns with error we simply
2232 * return. Later writepage will redirty the page and
2233 * writepages will find the dirty page again
2238 if (err
== -ENOSPC
&&
2239 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
2245 * get block failure will cause us to loop in
2246 * writepages, because a_ops->writepage won't be able
2247 * to make progress. The page will be redirtied by
2248 * writepage and writepages will again try to write
2251 ext4_msg(mpd
->inode
->i_sb
, KERN_CRIT
,
2252 "delayed block allocation failed for inode %lu at "
2253 "logical offset %llu with max blocks %zd with "
2254 "error %d\n", mpd
->inode
->i_ino
,
2255 (unsigned long long) next
,
2256 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2257 printk(KERN_CRIT
"This should not happen!! "
2258 "Data will be lost\n");
2259 if (err
== -ENOSPC
) {
2260 ext4_print_free_blocks(mpd
->inode
);
2262 /* invalidate all the pages */
2263 ext4_da_block_invalidatepages(mpd
, next
,
2264 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2269 new.b_size
= (blks
<< mpd
->inode
->i_blkbits
);
2271 if (buffer_new(&new))
2272 __unmap_underlying_blocks(mpd
->inode
, &new);
2275 * If blocks are delayed marked, we need to
2276 * put actual blocknr and drop delayed bit
2278 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2279 (mpd
->b_state
& (1 << BH_Unwritten
)))
2280 mpage_put_bnr_to_bhs(mpd
, next
, &new);
2282 if (ext4_should_order_data(mpd
->inode
)) {
2283 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
2289 * Update on-disk size along with block allocation.
2291 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
2292 if (disksize
> i_size_read(mpd
->inode
))
2293 disksize
= i_size_read(mpd
->inode
);
2294 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
2295 ext4_update_i_disksize(mpd
->inode
, disksize
);
2296 return ext4_mark_inode_dirty(handle
, mpd
->inode
);
2302 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2303 (1 << BH_Delay) | (1 << BH_Unwritten))
2306 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2308 * @mpd->lbh - extent of blocks
2309 * @logical - logical number of the block in the file
2310 * @bh - bh of the block (used to access block's state)
2312 * the function is used to collect contig. blocks in same state
2314 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2315 sector_t logical
, size_t b_size
,
2316 unsigned long b_state
)
2319 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2321 /* check if thereserved journal credits might overflow */
2322 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
2323 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2325 * With non-extent format we are limited by the journal
2326 * credit available. Total credit needed to insert
2327 * nrblocks contiguous blocks is dependent on the
2328 * nrblocks. So limit nrblocks.
2331 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2332 EXT4_MAX_TRANS_DATA
) {
2334 * Adding the new buffer_head would make it cross the
2335 * allowed limit for which we have journal credit
2336 * reserved. So limit the new bh->b_size
2338 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2339 mpd
->inode
->i_blkbits
;
2340 /* we will do mpage_da_submit_io in the next loop */
2344 * First block in the extent
2346 if (mpd
->b_size
== 0) {
2347 mpd
->b_blocknr
= logical
;
2348 mpd
->b_size
= b_size
;
2349 mpd
->b_state
= b_state
& BH_FLAGS
;
2353 next
= mpd
->b_blocknr
+ nrblocks
;
2355 * Can we merge the block to our big extent?
2357 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2358 mpd
->b_size
+= b_size
;
2364 * We couldn't merge the block to our extent, so we
2365 * need to flush current extent and start new one
2367 if (mpage_da_map_blocks(mpd
) == 0)
2368 mpage_da_submit_io(mpd
);
2373 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
)
2375 return (buffer_delay(bh
) || buffer_unwritten(bh
)) && buffer_dirty(bh
);
2379 * __mpage_da_writepage - finds extent of pages and blocks
2381 * @page: page to consider
2382 * @wbc: not used, we just follow rules
2385 * The function finds extents of pages and scan them for all blocks.
2387 static int __mpage_da_writepage(struct page
*page
,
2388 struct writeback_control
*wbc
, void *data
)
2390 struct mpage_da_data
*mpd
= data
;
2391 struct inode
*inode
= mpd
->inode
;
2392 struct buffer_head
*bh
, *head
;
2397 * Rest of the page in the page_vec
2398 * redirty then and skip then. We will
2399 * try to write them again after
2400 * starting a new transaction
2402 redirty_page_for_writepage(wbc
, page
);
2404 return MPAGE_DA_EXTENT_TAIL
;
2407 * Can we merge this page to current extent?
2409 if (mpd
->next_page
!= page
->index
) {
2411 * Nope, we can't. So, we map non-allocated blocks
2412 * and start IO on them using writepage()
2414 if (mpd
->next_page
!= mpd
->first_page
) {
2415 if (mpage_da_map_blocks(mpd
) == 0)
2416 mpage_da_submit_io(mpd
);
2418 * skip rest of the page in the page_vec
2421 redirty_page_for_writepage(wbc
, page
);
2423 return MPAGE_DA_EXTENT_TAIL
;
2427 * Start next extent of pages ...
2429 mpd
->first_page
= page
->index
;
2439 mpd
->next_page
= page
->index
+ 1;
2440 logical
= (sector_t
) page
->index
<<
2441 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2443 if (!page_has_buffers(page
)) {
2444 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2445 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2447 return MPAGE_DA_EXTENT_TAIL
;
2450 * Page with regular buffer heads, just add all dirty ones
2452 head
= page_buffers(page
);
2455 BUG_ON(buffer_locked(bh
));
2457 * We need to try to allocate
2458 * unmapped blocks in the same page.
2459 * Otherwise we won't make progress
2460 * with the page in ext4_writepage
2462 if (ext4_bh_delay_or_unwritten(NULL
, bh
)) {
2463 mpage_add_bh_to_extent(mpd
, logical
,
2467 return MPAGE_DA_EXTENT_TAIL
;
2468 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2470 * mapped dirty buffer. We need to update
2471 * the b_state because we look at
2472 * b_state in mpage_da_map_blocks. We don't
2473 * update b_size because if we find an
2474 * unmapped buffer_head later we need to
2475 * use the b_state flag of that buffer_head.
2477 if (mpd
->b_size
== 0)
2478 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2481 } while ((bh
= bh
->b_this_page
) != head
);
2488 * This is a special get_blocks_t callback which is used by
2489 * ext4_da_write_begin(). It will either return mapped block or
2490 * reserve space for a single block.
2492 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2493 * We also have b_blocknr = -1 and b_bdev initialized properly
2495 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2496 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2497 * initialized properly.
2499 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2500 struct buffer_head
*bh_result
, int create
)
2503 sector_t invalid_block
= ~((sector_t
) 0xffff);
2505 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
2508 BUG_ON(create
== 0);
2509 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2512 * first, we need to know whether the block is allocated already
2513 * preallocated blocks are unmapped but should treated
2514 * the same as allocated blocks.
2516 ret
= ext4_get_blocks(NULL
, inode
, iblock
, 1, bh_result
, 0);
2517 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2518 /* the block isn't (pre)allocated yet, let's reserve space */
2520 * XXX: __block_prepare_write() unmaps passed block,
2523 ret
= ext4_da_reserve_space(inode
, iblock
);
2525 /* not enough space to reserve */
2528 map_bh(bh_result
, inode
->i_sb
, invalid_block
);
2529 set_buffer_new(bh_result
);
2530 set_buffer_delay(bh_result
);
2531 } else if (ret
> 0) {
2532 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2533 if (buffer_unwritten(bh_result
)) {
2534 /* A delayed write to unwritten bh should
2535 * be marked new and mapped. Mapped ensures
2536 * that we don't do get_block multiple times
2537 * when we write to the same offset and new
2538 * ensures that we do proper zero out for
2541 set_buffer_new(bh_result
);
2542 set_buffer_mapped(bh_result
);
2551 * This function is used as a standard get_block_t calback function
2552 * when there is no desire to allocate any blocks. It is used as a
2553 * callback function for block_prepare_write(), nobh_writepage(), and
2554 * block_write_full_page(). These functions should only try to map a
2555 * single block at a time.
2557 * Since this function doesn't do block allocations even if the caller
2558 * requests it by passing in create=1, it is critically important that
2559 * any caller checks to make sure that any buffer heads are returned
2560 * by this function are either all already mapped or marked for
2561 * delayed allocation before calling nobh_writepage() or
2562 * block_write_full_page(). Otherwise, b_blocknr could be left
2563 * unitialized, and the page write functions will be taken by
2566 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
2567 struct buffer_head
*bh_result
, int create
)
2570 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2572 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2575 * we don't want to do block allocation in writepage
2576 * so call get_block_wrap with create = 0
2578 ret
= ext4_get_blocks(NULL
, inode
, iblock
, max_blocks
, bh_result
, 0);
2580 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2586 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2592 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2598 static int __ext4_journalled_writepage(struct page
*page
,
2601 struct address_space
*mapping
= page
->mapping
;
2602 struct inode
*inode
= mapping
->host
;
2603 struct buffer_head
*page_bufs
;
2604 handle_t
*handle
= NULL
;
2608 page_bufs
= page_buffers(page
);
2610 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bget_one
);
2611 /* As soon as we unlock the page, it can go away, but we have
2612 * references to buffers so we are safe */
2615 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
2616 if (IS_ERR(handle
)) {
2617 ret
= PTR_ERR(handle
);
2621 ret
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2622 do_journal_get_write_access
);
2624 err
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2628 err
= ext4_journal_stop(handle
);
2632 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bput_one
);
2633 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
2639 * Note that we don't need to start a transaction unless we're journaling data
2640 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2641 * need to file the inode to the transaction's list in ordered mode because if
2642 * we are writing back data added by write(), the inode is already there and if
2643 * we are writing back data modified via mmap(), noone guarantees in which
2644 * transaction the data will hit the disk. In case we are journaling data, we
2645 * cannot start transaction directly because transaction start ranks above page
2646 * lock so we have to do some magic.
2648 * This function can get called via...
2649 * - ext4_da_writepages after taking page lock (have journal handle)
2650 * - journal_submit_inode_data_buffers (no journal handle)
2651 * - shrink_page_list via pdflush (no journal handle)
2652 * - grab_page_cache when doing write_begin (have journal handle)
2654 * We don't do any block allocation in this function. If we have page with
2655 * multiple blocks we need to write those buffer_heads that are mapped. This
2656 * is important for mmaped based write. So if we do with blocksize 1K
2657 * truncate(f, 1024);
2658 * a = mmap(f, 0, 4096);
2660 * truncate(f, 4096);
2661 * we have in the page first buffer_head mapped via page_mkwrite call back
2662 * but other bufer_heads would be unmapped but dirty(dirty done via the
2663 * do_wp_page). So writepage should write the first block. If we modify
2664 * the mmap area beyond 1024 we will again get a page_fault and the
2665 * page_mkwrite callback will do the block allocation and mark the
2666 * buffer_heads mapped.
2668 * We redirty the page if we have any buffer_heads that is either delay or
2669 * unwritten in the page.
2671 * We can get recursively called as show below.
2673 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2676 * But since we don't do any block allocation we should not deadlock.
2677 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2679 static int ext4_writepage(struct page
*page
,
2680 struct writeback_control
*wbc
)
2685 struct buffer_head
*page_bufs
;
2686 struct inode
*inode
= page
->mapping
->host
;
2688 trace_ext4_writepage(inode
, page
);
2689 size
= i_size_read(inode
);
2690 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2691 len
= size
& ~PAGE_CACHE_MASK
;
2693 len
= PAGE_CACHE_SIZE
;
2695 if (page_has_buffers(page
)) {
2696 page_bufs
= page_buffers(page
);
2697 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2698 ext4_bh_delay_or_unwritten
)) {
2700 * We don't want to do block allocation
2701 * So redirty the page and return
2702 * We may reach here when we do a journal commit
2703 * via journal_submit_inode_data_buffers.
2704 * If we don't have mapping block we just ignore
2705 * them. We can also reach here via shrink_page_list
2707 redirty_page_for_writepage(wbc
, page
);
2713 * The test for page_has_buffers() is subtle:
2714 * We know the page is dirty but it lost buffers. That means
2715 * that at some moment in time after write_begin()/write_end()
2716 * has been called all buffers have been clean and thus they
2717 * must have been written at least once. So they are all
2718 * mapped and we can happily proceed with mapping them
2719 * and writing the page.
2721 * Try to initialize the buffer_heads and check whether
2722 * all are mapped and non delay. We don't want to
2723 * do block allocation here.
2725 ret
= block_prepare_write(page
, 0, len
,
2726 noalloc_get_block_write
);
2728 page_bufs
= page_buffers(page
);
2729 /* check whether all are mapped and non delay */
2730 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2731 ext4_bh_delay_or_unwritten
)) {
2732 redirty_page_for_writepage(wbc
, page
);
2738 * We can't do block allocation here
2739 * so just redity the page and unlock
2742 redirty_page_for_writepage(wbc
, page
);
2746 /* now mark the buffer_heads as dirty and uptodate */
2747 block_commit_write(page
, 0, len
);
2750 if (PageChecked(page
) && ext4_should_journal_data(inode
)) {
2752 * It's mmapped pagecache. Add buffers and journal it. There
2753 * doesn't seem much point in redirtying the page here.
2755 ClearPageChecked(page
);
2756 return __ext4_journalled_writepage(page
, len
);
2759 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2760 ret
= nobh_writepage(page
, noalloc_get_block_write
, wbc
);
2762 ret
= block_write_full_page(page
, noalloc_get_block_write
,
2769 * This is called via ext4_da_writepages() to
2770 * calulate the total number of credits to reserve to fit
2771 * a single extent allocation into a single transaction,
2772 * ext4_da_writpeages() will loop calling this before
2773 * the block allocation.
2776 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2778 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2781 * With non-extent format the journal credit needed to
2782 * insert nrblocks contiguous block is dependent on
2783 * number of contiguous block. So we will limit
2784 * number of contiguous block to a sane value
2786 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) &&
2787 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2788 max_blocks
= EXT4_MAX_TRANS_DATA
;
2790 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2793 static int ext4_da_writepages(struct address_space
*mapping
,
2794 struct writeback_control
*wbc
)
2797 int range_whole
= 0;
2798 handle_t
*handle
= NULL
;
2799 struct mpage_da_data mpd
;
2800 struct inode
*inode
= mapping
->host
;
2801 int no_nrwrite_index_update
;
2802 int pages_written
= 0;
2804 unsigned int max_pages
;
2805 int range_cyclic
, cycled
= 1, io_done
= 0;
2806 int needed_blocks
, ret
= 0;
2807 long desired_nr_to_write
, nr_to_writebump
= 0;
2808 loff_t range_start
= wbc
->range_start
;
2809 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2811 trace_ext4_da_writepages(inode
, wbc
);
2814 * No pages to write? This is mainly a kludge to avoid starting
2815 * a transaction for special inodes like journal inode on last iput()
2816 * because that could violate lock ordering on umount
2818 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2822 * If the filesystem has aborted, it is read-only, so return
2823 * right away instead of dumping stack traces later on that
2824 * will obscure the real source of the problem. We test
2825 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2826 * the latter could be true if the filesystem is mounted
2827 * read-only, and in that case, ext4_da_writepages should
2828 * *never* be called, so if that ever happens, we would want
2831 if (unlikely(sbi
->s_mount_flags
& EXT4_MF_FS_ABORTED
))
2834 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2837 range_cyclic
= wbc
->range_cyclic
;
2838 if (wbc
->range_cyclic
) {
2839 index
= mapping
->writeback_index
;
2842 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2843 wbc
->range_end
= LLONG_MAX
;
2844 wbc
->range_cyclic
= 0;
2846 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2849 * This works around two forms of stupidity. The first is in
2850 * the writeback code, which caps the maximum number of pages
2851 * written to be 1024 pages. This is wrong on multiple
2852 * levels; different architectues have a different page size,
2853 * which changes the maximum amount of data which gets
2854 * written. Secondly, 4 megabytes is way too small. XFS
2855 * forces this value to be 16 megabytes by multiplying
2856 * nr_to_write parameter by four, and then relies on its
2857 * allocator to allocate larger extents to make them
2858 * contiguous. Unfortunately this brings us to the second
2859 * stupidity, which is that ext4's mballoc code only allocates
2860 * at most 2048 blocks. So we force contiguous writes up to
2861 * the number of dirty blocks in the inode, or
2862 * sbi->max_writeback_mb_bump whichever is smaller.
2864 max_pages
= sbi
->s_max_writeback_mb_bump
<< (20 - PAGE_CACHE_SHIFT
);
2865 if (!range_cyclic
&& range_whole
)
2866 desired_nr_to_write
= wbc
->nr_to_write
* 8;
2868 desired_nr_to_write
= ext4_num_dirty_pages(inode
, index
,
2870 if (desired_nr_to_write
> max_pages
)
2871 desired_nr_to_write
= max_pages
;
2873 if (wbc
->nr_to_write
< desired_nr_to_write
) {
2874 nr_to_writebump
= desired_nr_to_write
- wbc
->nr_to_write
;
2875 wbc
->nr_to_write
= desired_nr_to_write
;
2879 mpd
.inode
= mapping
->host
;
2882 * we don't want write_cache_pages to update
2883 * nr_to_write and writeback_index
2885 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2886 wbc
->no_nrwrite_index_update
= 1;
2887 pages_skipped
= wbc
->pages_skipped
;
2890 while (!ret
&& wbc
->nr_to_write
> 0) {
2893 * we insert one extent at a time. So we need
2894 * credit needed for single extent allocation.
2895 * journalled mode is currently not supported
2898 BUG_ON(ext4_should_journal_data(inode
));
2899 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2901 /* start a new transaction*/
2902 handle
= ext4_journal_start(inode
, needed_blocks
);
2903 if (IS_ERR(handle
)) {
2904 ret
= PTR_ERR(handle
);
2905 ext4_msg(inode
->i_sb
, KERN_CRIT
, "%s: jbd2_start: "
2906 "%ld pages, ino %lu; err %d\n", __func__
,
2907 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2908 goto out_writepages
;
2912 * Now call __mpage_da_writepage to find the next
2913 * contiguous region of logical blocks that need
2914 * blocks to be allocated by ext4. We don't actually
2915 * submit the blocks for I/O here, even though
2916 * write_cache_pages thinks it will, and will set the
2917 * pages as clean for write before calling
2918 * __mpage_da_writepage().
2926 mpd
.pages_written
= 0;
2928 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
,
2931 * If we have a contiguous extent of pages and we
2932 * haven't done the I/O yet, map the blocks and submit
2935 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
2936 if (mpage_da_map_blocks(&mpd
) == 0)
2937 mpage_da_submit_io(&mpd
);
2939 ret
= MPAGE_DA_EXTENT_TAIL
;
2941 trace_ext4_da_write_pages(inode
, &mpd
);
2942 wbc
->nr_to_write
-= mpd
.pages_written
;
2944 ext4_journal_stop(handle
);
2946 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2947 /* commit the transaction which would
2948 * free blocks released in the transaction
2951 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2952 wbc
->pages_skipped
= pages_skipped
;
2954 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2956 * got one extent now try with
2959 pages_written
+= mpd
.pages_written
;
2960 wbc
->pages_skipped
= pages_skipped
;
2963 } else if (wbc
->nr_to_write
)
2965 * There is no more writeout needed
2966 * or we requested for a noblocking writeout
2967 * and we found the device congested
2971 if (!io_done
&& !cycled
) {
2974 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2975 wbc
->range_end
= mapping
->writeback_index
- 1;
2978 if (pages_skipped
!= wbc
->pages_skipped
)
2979 ext4_msg(inode
->i_sb
, KERN_CRIT
,
2980 "This should not happen leaving %s "
2981 "with nr_to_write = %ld ret = %d\n",
2982 __func__
, wbc
->nr_to_write
, ret
);
2985 index
+= pages_written
;
2986 wbc
->range_cyclic
= range_cyclic
;
2987 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2989 * set the writeback_index so that range_cyclic
2990 * mode will write it back later
2992 mapping
->writeback_index
= index
;
2995 if (!no_nrwrite_index_update
)
2996 wbc
->no_nrwrite_index_update
= 0;
2997 wbc
->nr_to_write
-= nr_to_writebump
;
2998 wbc
->range_start
= range_start
;
2999 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
3003 #define FALL_BACK_TO_NONDELALLOC 1
3004 static int ext4_nonda_switch(struct super_block
*sb
)
3006 s64 free_blocks
, dirty_blocks
;
3007 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3010 * switch to non delalloc mode if we are running low
3011 * on free block. The free block accounting via percpu
3012 * counters can get slightly wrong with percpu_counter_batch getting
3013 * accumulated on each CPU without updating global counters
3014 * Delalloc need an accurate free block accounting. So switch
3015 * to non delalloc when we are near to error range.
3017 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
3018 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
3019 if (2 * free_blocks
< 3 * dirty_blocks
||
3020 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
3022 * free block count is less than 150% of dirty blocks
3023 * or free blocks is less than watermark
3028 * Even if we don't switch but are nearing capacity,
3029 * start pushing delalloc when 1/2 of free blocks are dirty.
3031 if (free_blocks
< 2 * dirty_blocks
)
3032 writeback_inodes_sb_if_idle(sb
);
3037 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
3038 loff_t pos
, unsigned len
, unsigned flags
,
3039 struct page
**pagep
, void **fsdata
)
3041 int ret
, retries
= 0, quota_retries
= 0;
3045 struct inode
*inode
= mapping
->host
;
3048 index
= pos
>> PAGE_CACHE_SHIFT
;
3049 from
= pos
& (PAGE_CACHE_SIZE
- 1);
3052 if (ext4_nonda_switch(inode
->i_sb
)) {
3053 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
3054 return ext4_write_begin(file
, mapping
, pos
,
3055 len
, flags
, pagep
, fsdata
);
3057 *fsdata
= (void *)0;
3058 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
3061 * With delayed allocation, we don't log the i_disksize update
3062 * if there is delayed block allocation. But we still need
3063 * to journalling the i_disksize update if writes to the end
3064 * of file which has an already mapped buffer.
3066 handle
= ext4_journal_start(inode
, 1);
3067 if (IS_ERR(handle
)) {
3068 ret
= PTR_ERR(handle
);
3071 /* We cannot recurse into the filesystem as the transaction is already
3073 flags
|= AOP_FLAG_NOFS
;
3075 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
3077 ext4_journal_stop(handle
);
3083 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
3084 ext4_da_get_block_prep
);
3087 ext4_journal_stop(handle
);
3088 page_cache_release(page
);
3090 * block_write_begin may have instantiated a few blocks
3091 * outside i_size. Trim these off again. Don't need
3092 * i_size_read because we hold i_mutex.
3094 if (pos
+ len
> inode
->i_size
)
3095 ext4_truncate_failed_write(inode
);
3098 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3101 if ((ret
== -EDQUOT
) &&
3102 EXT4_I(inode
)->i_reserved_meta_blocks
&&
3103 (quota_retries
++ < 3)) {
3105 * Since we often over-estimate the number of meta
3106 * data blocks required, we may sometimes get a
3107 * spurios out of quota error even though there would
3108 * be enough space once we write the data blocks and
3109 * find out how many meta data blocks were _really_
3110 * required. So try forcing the inode write to see if
3113 write_inode_now(inode
, (quota_retries
== 3));
3121 * Check if we should update i_disksize
3122 * when write to the end of file but not require block allocation
3124 static int ext4_da_should_update_i_disksize(struct page
*page
,
3125 unsigned long offset
)
3127 struct buffer_head
*bh
;
3128 struct inode
*inode
= page
->mapping
->host
;
3132 bh
= page_buffers(page
);
3133 idx
= offset
>> inode
->i_blkbits
;
3135 for (i
= 0; i
< idx
; i
++)
3136 bh
= bh
->b_this_page
;
3138 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
3143 static int ext4_da_write_end(struct file
*file
,
3144 struct address_space
*mapping
,
3145 loff_t pos
, unsigned len
, unsigned copied
,
3146 struct page
*page
, void *fsdata
)
3148 struct inode
*inode
= mapping
->host
;
3150 handle_t
*handle
= ext4_journal_current_handle();
3152 unsigned long start
, end
;
3153 int write_mode
= (int)(unsigned long)fsdata
;
3155 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
3156 if (ext4_should_order_data(inode
)) {
3157 return ext4_ordered_write_end(file
, mapping
, pos
,
3158 len
, copied
, page
, fsdata
);
3159 } else if (ext4_should_writeback_data(inode
)) {
3160 return ext4_writeback_write_end(file
, mapping
, pos
,
3161 len
, copied
, page
, fsdata
);
3167 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
3168 start
= pos
& (PAGE_CACHE_SIZE
- 1);
3169 end
= start
+ copied
- 1;
3172 * generic_write_end() will run mark_inode_dirty() if i_size
3173 * changes. So let's piggyback the i_disksize mark_inode_dirty
3177 new_i_size
= pos
+ copied
;
3178 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3179 if (ext4_da_should_update_i_disksize(page
, end
)) {
3180 down_write(&EXT4_I(inode
)->i_data_sem
);
3181 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3183 * Updating i_disksize when extending file
3184 * without needing block allocation
3186 if (ext4_should_order_data(inode
))
3187 ret
= ext4_jbd2_file_inode(handle
,
3190 EXT4_I(inode
)->i_disksize
= new_i_size
;
3192 up_write(&EXT4_I(inode
)->i_data_sem
);
3193 /* We need to mark inode dirty even if
3194 * new_i_size is less that inode->i_size
3195 * bu greater than i_disksize.(hint delalloc)
3197 ext4_mark_inode_dirty(handle
, inode
);
3200 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
3205 ret2
= ext4_journal_stop(handle
);
3209 return ret
? ret
: copied
;
3212 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
3215 * Drop reserved blocks
3217 BUG_ON(!PageLocked(page
));
3218 if (!page_has_buffers(page
))
3221 ext4_da_page_release_reservation(page
, offset
);
3224 ext4_invalidatepage(page
, offset
);
3230 * Force all delayed allocation blocks to be allocated for a given inode.
3232 int ext4_alloc_da_blocks(struct inode
*inode
)
3234 trace_ext4_alloc_da_blocks(inode
);
3236 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
3237 !EXT4_I(inode
)->i_reserved_meta_blocks
)
3241 * We do something simple for now. The filemap_flush() will
3242 * also start triggering a write of the data blocks, which is
3243 * not strictly speaking necessary (and for users of
3244 * laptop_mode, not even desirable). However, to do otherwise
3245 * would require replicating code paths in:
3247 * ext4_da_writepages() ->
3248 * write_cache_pages() ---> (via passed in callback function)
3249 * __mpage_da_writepage() -->
3250 * mpage_add_bh_to_extent()
3251 * mpage_da_map_blocks()
3253 * The problem is that write_cache_pages(), located in
3254 * mm/page-writeback.c, marks pages clean in preparation for
3255 * doing I/O, which is not desirable if we're not planning on
3258 * We could call write_cache_pages(), and then redirty all of
3259 * the pages by calling redirty_page_for_writeback() but that
3260 * would be ugly in the extreme. So instead we would need to
3261 * replicate parts of the code in the above functions,
3262 * simplifying them becuase we wouldn't actually intend to
3263 * write out the pages, but rather only collect contiguous
3264 * logical block extents, call the multi-block allocator, and
3265 * then update the buffer heads with the block allocations.
3267 * For now, though, we'll cheat by calling filemap_flush(),
3268 * which will map the blocks, and start the I/O, but not
3269 * actually wait for the I/O to complete.
3271 return filemap_flush(inode
->i_mapping
);
3275 * bmap() is special. It gets used by applications such as lilo and by
3276 * the swapper to find the on-disk block of a specific piece of data.
3278 * Naturally, this is dangerous if the block concerned is still in the
3279 * journal. If somebody makes a swapfile on an ext4 data-journaling
3280 * filesystem and enables swap, then they may get a nasty shock when the
3281 * data getting swapped to that swapfile suddenly gets overwritten by
3282 * the original zero's written out previously to the journal and
3283 * awaiting writeback in the kernel's buffer cache.
3285 * So, if we see any bmap calls here on a modified, data-journaled file,
3286 * take extra steps to flush any blocks which might be in the cache.
3288 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
3290 struct inode
*inode
= mapping
->host
;
3294 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
3295 test_opt(inode
->i_sb
, DELALLOC
)) {
3297 * With delalloc we want to sync the file
3298 * so that we can make sure we allocate
3301 filemap_write_and_wait(mapping
);
3304 if (EXT4_JOURNAL(inode
) && EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
3306 * This is a REALLY heavyweight approach, but the use of
3307 * bmap on dirty files is expected to be extremely rare:
3308 * only if we run lilo or swapon on a freshly made file
3309 * do we expect this to happen.
3311 * (bmap requires CAP_SYS_RAWIO so this does not
3312 * represent an unprivileged user DOS attack --- we'd be
3313 * in trouble if mortal users could trigger this path at
3316 * NB. EXT4_STATE_JDATA is not set on files other than
3317 * regular files. If somebody wants to bmap a directory
3318 * or symlink and gets confused because the buffer
3319 * hasn't yet been flushed to disk, they deserve
3320 * everything they get.
3323 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
3324 journal
= EXT4_JOURNAL(inode
);
3325 jbd2_journal_lock_updates(journal
);
3326 err
= jbd2_journal_flush(journal
);
3327 jbd2_journal_unlock_updates(journal
);
3333 return generic_block_bmap(mapping
, block
, ext4_get_block
);
3336 static int ext4_readpage(struct file
*file
, struct page
*page
)
3338 return mpage_readpage(page
, ext4_get_block
);
3342 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3343 struct list_head
*pages
, unsigned nr_pages
)
3345 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3348 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3350 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3353 * If it's a full truncate we just forget about the pending dirtying
3356 ClearPageChecked(page
);
3359 jbd2_journal_invalidatepage(journal
, page
, offset
);
3361 block_invalidatepage(page
, offset
);
3364 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3366 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3368 WARN_ON(PageChecked(page
));
3369 if (!page_has_buffers(page
))
3372 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3374 return try_to_free_buffers(page
);
3378 * O_DIRECT for ext3 (or indirect map) based files
3380 * If the O_DIRECT write will extend the file then add this inode to the
3381 * orphan list. So recovery will truncate it back to the original size
3382 * if the machine crashes during the write.
3384 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3385 * crashes then stale disk data _may_ be exposed inside the file. But current
3386 * VFS code falls back into buffered path in that case so we are safe.
3388 static ssize_t
ext4_ind_direct_IO(int rw
, struct kiocb
*iocb
,
3389 const struct iovec
*iov
, loff_t offset
,
3390 unsigned long nr_segs
)
3392 struct file
*file
= iocb
->ki_filp
;
3393 struct inode
*inode
= file
->f_mapping
->host
;
3394 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3398 size_t count
= iov_length(iov
, nr_segs
);
3402 loff_t final_size
= offset
+ count
;
3404 if (final_size
> inode
->i_size
) {
3405 /* Credits for sb + inode write */
3406 handle
= ext4_journal_start(inode
, 2);
3407 if (IS_ERR(handle
)) {
3408 ret
= PTR_ERR(handle
);
3411 ret
= ext4_orphan_add(handle
, inode
);
3413 ext4_journal_stop(handle
);
3417 ei
->i_disksize
= inode
->i_size
;
3418 ext4_journal_stop(handle
);
3423 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3425 ext4_get_block
, NULL
);
3426 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3432 /* Credits for sb + inode write */
3433 handle
= ext4_journal_start(inode
, 2);
3434 if (IS_ERR(handle
)) {
3435 /* This is really bad luck. We've written the data
3436 * but cannot extend i_size. Bail out and pretend
3437 * the write failed... */
3438 ret
= PTR_ERR(handle
);
3442 ext4_orphan_del(handle
, inode
);
3444 loff_t end
= offset
+ ret
;
3445 if (end
> inode
->i_size
) {
3446 ei
->i_disksize
= end
;
3447 i_size_write(inode
, end
);
3449 * We're going to return a positive `ret'
3450 * here due to non-zero-length I/O, so there's
3451 * no way of reporting error returns from
3452 * ext4_mark_inode_dirty() to userspace. So
3455 ext4_mark_inode_dirty(handle
, inode
);
3458 err
= ext4_journal_stop(handle
);
3466 static int ext4_get_block_dio_write(struct inode
*inode
, sector_t iblock
,
3467 struct buffer_head
*bh_result
, int create
)
3469 handle_t
*handle
= NULL
;
3471 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
3474 ext4_debug("ext4_get_block_dio_write: inode %lu, create flag %d\n",
3475 inode
->i_ino
, create
);
3477 * DIO VFS code passes create = 0 flag for write to
3478 * the middle of file. It does this to avoid block
3479 * allocation for holes, to prevent expose stale data
3480 * out when there is parallel buffered read (which does
3481 * not hold the i_mutex lock) while direct IO write has
3482 * not completed. DIO request on holes finally falls back
3483 * to buffered IO for this reason.
3485 * For ext4 extent based file, since we support fallocate,
3486 * new allocated extent as uninitialized, for holes, we
3487 * could fallocate blocks for holes, thus parallel
3488 * buffered IO read will zero out the page when read on
3489 * a hole while parallel DIO write to the hole has not completed.
3491 * when we come here, we know it's a direct IO write to
3492 * to the middle of file (<i_size)
3493 * so it's safe to override the create flag from VFS.
3495 create
= EXT4_GET_BLOCKS_DIO_CREATE_EXT
;
3497 if (max_blocks
> DIO_MAX_BLOCKS
)
3498 max_blocks
= DIO_MAX_BLOCKS
;
3499 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
3500 handle
= ext4_journal_start(inode
, dio_credits
);
3501 if (IS_ERR(handle
)) {
3502 ret
= PTR_ERR(handle
);
3505 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
3508 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
3511 ext4_journal_stop(handle
);
3516 static void ext4_free_io_end(ext4_io_end_t
*io
)
3522 static void dump_aio_dio_list(struct inode
* inode
)
3525 struct list_head
*cur
, *before
, *after
;
3526 ext4_io_end_t
*io
, *io0
, *io1
;
3528 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3529 ext4_debug("inode %lu aio dio list is empty\n", inode
->i_ino
);
3533 ext4_debug("Dump inode %lu aio_dio_completed_IO list \n", inode
->i_ino
);
3534 list_for_each_entry(io
, &EXT4_I(inode
)->i_aio_dio_complete_list
, list
){
3537 io0
= container_of(before
, ext4_io_end_t
, list
);
3539 io1
= container_of(after
, ext4_io_end_t
, list
);
3541 ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
3542 io
, inode
->i_ino
, io0
, io1
);
3548 * check a range of space and convert unwritten extents to written.
3550 static int ext4_end_aio_dio_nolock(ext4_io_end_t
*io
)
3552 struct inode
*inode
= io
->inode
;
3553 loff_t offset
= io
->offset
;
3554 size_t size
= io
->size
;
3557 ext4_debug("end_aio_dio_onlock: io 0x%p from inode %lu,list->next 0x%p,"
3558 "list->prev 0x%p\n",
3559 io
, inode
->i_ino
, io
->list
.next
, io
->list
.prev
);
3561 if (list_empty(&io
->list
))
3564 if (io
->flag
!= DIO_AIO_UNWRITTEN
)
3567 if (offset
+ size
<= i_size_read(inode
))
3568 ret
= ext4_convert_unwritten_extents(inode
, offset
, size
);
3571 printk(KERN_EMERG
"%s: failed to convert unwritten"
3572 "extents to written extents, error is %d"
3573 " io is still on inode %lu aio dio list\n",
3574 __func__
, ret
, inode
->i_ino
);
3578 /* clear the DIO AIO unwritten flag */
3583 * work on completed aio dio IO, to convert unwritten extents to extents
3585 static void ext4_end_aio_dio_work(struct work_struct
*work
)
3587 ext4_io_end_t
*io
= container_of(work
, ext4_io_end_t
, work
);
3588 struct inode
*inode
= io
->inode
;
3591 mutex_lock(&inode
->i_mutex
);
3592 ret
= ext4_end_aio_dio_nolock(io
);
3594 if (!list_empty(&io
->list
))
3595 list_del_init(&io
->list
);
3596 ext4_free_io_end(io
);
3598 mutex_unlock(&inode
->i_mutex
);
3601 * This function is called from ext4_sync_file().
3603 * When AIO DIO IO is completed, the work to convert unwritten
3604 * extents to written is queued on workqueue but may not get immediately
3605 * scheduled. When fsync is called, we need to ensure the
3606 * conversion is complete before fsync returns.
3607 * The inode keeps track of a list of completed AIO from DIO path
3608 * that might needs to do the conversion. This function walks through
3609 * the list and convert the related unwritten extents to written.
3611 int flush_aio_dio_completed_IO(struct inode
*inode
)
3617 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
))
3620 dump_aio_dio_list(inode
);
3621 while (!list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3622 io
= list_entry(EXT4_I(inode
)->i_aio_dio_complete_list
.next
,
3623 ext4_io_end_t
, list
);
3625 * Calling ext4_end_aio_dio_nolock() to convert completed
3628 * When ext4_sync_file() is called, run_queue() may already
3629 * about to flush the work corresponding to this io structure.
3630 * It will be upset if it founds the io structure related
3631 * to the work-to-be schedule is freed.
3633 * Thus we need to keep the io structure still valid here after
3634 * convertion finished. The io structure has a flag to
3635 * avoid double converting from both fsync and background work
3638 ret
= ext4_end_aio_dio_nolock(io
);
3642 list_del_init(&io
->list
);
3644 return (ret2
< 0) ? ret2
: 0;
3647 static ext4_io_end_t
*ext4_init_io_end (struct inode
*inode
)
3649 ext4_io_end_t
*io
= NULL
;
3651 io
= kmalloc(sizeof(*io
), GFP_NOFS
);
3660 INIT_WORK(&io
->work
, ext4_end_aio_dio_work
);
3661 INIT_LIST_HEAD(&io
->list
);
3667 static void ext4_end_io_dio(struct kiocb
*iocb
, loff_t offset
,
3668 ssize_t size
, void *private)
3670 ext4_io_end_t
*io_end
= iocb
->private;
3671 struct workqueue_struct
*wq
;
3673 /* if not async direct IO or dio with 0 bytes write, just return */
3674 if (!io_end
|| !size
)
3677 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3678 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3679 iocb
->private, io_end
->inode
->i_ino
, iocb
, offset
,
3682 /* if not aio dio with unwritten extents, just free io and return */
3683 if (io_end
->flag
!= DIO_AIO_UNWRITTEN
){
3684 ext4_free_io_end(io_end
);
3685 iocb
->private = NULL
;
3689 io_end
->offset
= offset
;
3690 io_end
->size
= size
;
3691 wq
= EXT4_SB(io_end
->inode
->i_sb
)->dio_unwritten_wq
;
3693 /* queue the work to convert unwritten extents to written */
3694 queue_work(wq
, &io_end
->work
);
3696 /* Add the io_end to per-inode completed aio dio list*/
3697 list_add_tail(&io_end
->list
,
3698 &EXT4_I(io_end
->inode
)->i_aio_dio_complete_list
);
3699 iocb
->private = NULL
;
3702 * For ext4 extent files, ext4 will do direct-io write to holes,
3703 * preallocated extents, and those write extend the file, no need to
3704 * fall back to buffered IO.
3706 * For holes, we fallocate those blocks, mark them as unintialized
3707 * If those blocks were preallocated, we mark sure they are splited, but
3708 * still keep the range to write as unintialized.
3710 * The unwrritten extents will be converted to written when DIO is completed.
3711 * For async direct IO, since the IO may still pending when return, we
3712 * set up an end_io call back function, which will do the convertion
3713 * when async direct IO completed.
3715 * If the O_DIRECT write will extend the file then add this inode to the
3716 * orphan list. So recovery will truncate it back to the original size
3717 * if the machine crashes during the write.
3720 static ssize_t
ext4_ext_direct_IO(int rw
, struct kiocb
*iocb
,
3721 const struct iovec
*iov
, loff_t offset
,
3722 unsigned long nr_segs
)
3724 struct file
*file
= iocb
->ki_filp
;
3725 struct inode
*inode
= file
->f_mapping
->host
;
3727 size_t count
= iov_length(iov
, nr_segs
);
3729 loff_t final_size
= offset
+ count
;
3730 if (rw
== WRITE
&& final_size
<= inode
->i_size
) {
3732 * We could direct write to holes and fallocate.
3734 * Allocated blocks to fill the hole are marked as uninitialized
3735 * to prevent paralel buffered read to expose the stale data
3736 * before DIO complete the data IO.
3738 * As to previously fallocated extents, ext4 get_block
3739 * will just simply mark the buffer mapped but still
3740 * keep the extents uninitialized.
3742 * for non AIO case, we will convert those unwritten extents
3743 * to written after return back from blockdev_direct_IO.
3745 * for async DIO, the conversion needs to be defered when
3746 * the IO is completed. The ext4 end_io callback function
3747 * will be called to take care of the conversion work.
3748 * Here for async case, we allocate an io_end structure to
3751 iocb
->private = NULL
;
3752 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3753 if (!is_sync_kiocb(iocb
)) {
3754 iocb
->private = ext4_init_io_end(inode
);
3758 * we save the io structure for current async
3759 * direct IO, so that later ext4_get_blocks()
3760 * could flag the io structure whether there
3761 * is a unwritten extents needs to be converted
3762 * when IO is completed.
3764 EXT4_I(inode
)->cur_aio_dio
= iocb
->private;
3767 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3768 inode
->i_sb
->s_bdev
, iov
,
3770 ext4_get_block_dio_write
,
3773 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3775 * The io_end structure takes a reference to the inode,
3776 * that structure needs to be destroyed and the
3777 * reference to the inode need to be dropped, when IO is
3778 * complete, even with 0 byte write, or failed.
3780 * In the successful AIO DIO case, the io_end structure will be
3781 * desctroyed and the reference to the inode will be dropped
3782 * after the end_io call back function is called.
3784 * In the case there is 0 byte write, or error case, since
3785 * VFS direct IO won't invoke the end_io call back function,
3786 * we need to free the end_io structure here.
3788 if (ret
!= -EIOCBQUEUED
&& ret
<= 0 && iocb
->private) {
3789 ext4_free_io_end(iocb
->private);
3790 iocb
->private = NULL
;
3791 } else if (ret
> 0 && (EXT4_I(inode
)->i_state
&
3792 EXT4_STATE_DIO_UNWRITTEN
)) {
3795 * for non AIO case, since the IO is already
3796 * completed, we could do the convertion right here
3798 err
= ext4_convert_unwritten_extents(inode
,
3802 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_DIO_UNWRITTEN
;
3807 /* for write the the end of file case, we fall back to old way */
3808 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3811 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3812 const struct iovec
*iov
, loff_t offset
,
3813 unsigned long nr_segs
)
3815 struct file
*file
= iocb
->ki_filp
;
3816 struct inode
*inode
= file
->f_mapping
->host
;
3818 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
3819 return ext4_ext_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3821 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3825 * Pages can be marked dirty completely asynchronously from ext4's journalling
3826 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3827 * much here because ->set_page_dirty is called under VFS locks. The page is
3828 * not necessarily locked.
3830 * We cannot just dirty the page and leave attached buffers clean, because the
3831 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3832 * or jbddirty because all the journalling code will explode.
3834 * So what we do is to mark the page "pending dirty" and next time writepage
3835 * is called, propagate that into the buffers appropriately.
3837 static int ext4_journalled_set_page_dirty(struct page
*page
)
3839 SetPageChecked(page
);
3840 return __set_page_dirty_nobuffers(page
);
3843 static const struct address_space_operations ext4_ordered_aops
= {
3844 .readpage
= ext4_readpage
,
3845 .readpages
= ext4_readpages
,
3846 .writepage
= ext4_writepage
,
3847 .sync_page
= block_sync_page
,
3848 .write_begin
= ext4_write_begin
,
3849 .write_end
= ext4_ordered_write_end
,
3851 .invalidatepage
= ext4_invalidatepage
,
3852 .releasepage
= ext4_releasepage
,
3853 .direct_IO
= ext4_direct_IO
,
3854 .migratepage
= buffer_migrate_page
,
3855 .is_partially_uptodate
= block_is_partially_uptodate
,
3856 .error_remove_page
= generic_error_remove_page
,
3859 static const struct address_space_operations ext4_writeback_aops
= {
3860 .readpage
= ext4_readpage
,
3861 .readpages
= ext4_readpages
,
3862 .writepage
= ext4_writepage
,
3863 .sync_page
= block_sync_page
,
3864 .write_begin
= ext4_write_begin
,
3865 .write_end
= ext4_writeback_write_end
,
3867 .invalidatepage
= ext4_invalidatepage
,
3868 .releasepage
= ext4_releasepage
,
3869 .direct_IO
= ext4_direct_IO
,
3870 .migratepage
= buffer_migrate_page
,
3871 .is_partially_uptodate
= block_is_partially_uptodate
,
3872 .error_remove_page
= generic_error_remove_page
,
3875 static const struct address_space_operations ext4_journalled_aops
= {
3876 .readpage
= ext4_readpage
,
3877 .readpages
= ext4_readpages
,
3878 .writepage
= ext4_writepage
,
3879 .sync_page
= block_sync_page
,
3880 .write_begin
= ext4_write_begin
,
3881 .write_end
= ext4_journalled_write_end
,
3882 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3884 .invalidatepage
= ext4_invalidatepage
,
3885 .releasepage
= ext4_releasepage
,
3886 .is_partially_uptodate
= block_is_partially_uptodate
,
3887 .error_remove_page
= generic_error_remove_page
,
3890 static const struct address_space_operations ext4_da_aops
= {
3891 .readpage
= ext4_readpage
,
3892 .readpages
= ext4_readpages
,
3893 .writepage
= ext4_writepage
,
3894 .writepages
= ext4_da_writepages
,
3895 .sync_page
= block_sync_page
,
3896 .write_begin
= ext4_da_write_begin
,
3897 .write_end
= ext4_da_write_end
,
3899 .invalidatepage
= ext4_da_invalidatepage
,
3900 .releasepage
= ext4_releasepage
,
3901 .direct_IO
= ext4_direct_IO
,
3902 .migratepage
= buffer_migrate_page
,
3903 .is_partially_uptodate
= block_is_partially_uptodate
,
3904 .error_remove_page
= generic_error_remove_page
,
3907 void ext4_set_aops(struct inode
*inode
)
3909 if (ext4_should_order_data(inode
) &&
3910 test_opt(inode
->i_sb
, DELALLOC
))
3911 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3912 else if (ext4_should_order_data(inode
))
3913 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3914 else if (ext4_should_writeback_data(inode
) &&
3915 test_opt(inode
->i_sb
, DELALLOC
))
3916 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3917 else if (ext4_should_writeback_data(inode
))
3918 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3920 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3924 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3925 * up to the end of the block which corresponds to `from'.
3926 * This required during truncate. We need to physically zero the tail end
3927 * of that block so it doesn't yield old data if the file is later grown.
3929 int ext4_block_truncate_page(handle_t
*handle
,
3930 struct address_space
*mapping
, loff_t from
)
3932 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3933 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3934 unsigned blocksize
, length
, pos
;
3936 struct inode
*inode
= mapping
->host
;
3937 struct buffer_head
*bh
;
3941 page
= find_or_create_page(mapping
, from
>> PAGE_CACHE_SHIFT
,
3942 mapping_gfp_mask(mapping
) & ~__GFP_FS
);
3946 blocksize
= inode
->i_sb
->s_blocksize
;
3947 length
= blocksize
- (offset
& (blocksize
- 1));
3948 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3951 * For "nobh" option, we can only work if we don't need to
3952 * read-in the page - otherwise we create buffers to do the IO.
3954 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3955 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3956 zero_user(page
, offset
, length
);
3957 set_page_dirty(page
);
3961 if (!page_has_buffers(page
))
3962 create_empty_buffers(page
, blocksize
, 0);
3964 /* Find the buffer that contains "offset" */
3965 bh
= page_buffers(page
);
3967 while (offset
>= pos
) {
3968 bh
= bh
->b_this_page
;
3974 if (buffer_freed(bh
)) {
3975 BUFFER_TRACE(bh
, "freed: skip");
3979 if (!buffer_mapped(bh
)) {
3980 BUFFER_TRACE(bh
, "unmapped");
3981 ext4_get_block(inode
, iblock
, bh
, 0);
3982 /* unmapped? It's a hole - nothing to do */
3983 if (!buffer_mapped(bh
)) {
3984 BUFFER_TRACE(bh
, "still unmapped");
3989 /* Ok, it's mapped. Make sure it's up-to-date */
3990 if (PageUptodate(page
))
3991 set_buffer_uptodate(bh
);
3993 if (!buffer_uptodate(bh
)) {
3995 ll_rw_block(READ
, 1, &bh
);
3997 /* Uhhuh. Read error. Complain and punt. */
3998 if (!buffer_uptodate(bh
))
4002 if (ext4_should_journal_data(inode
)) {
4003 BUFFER_TRACE(bh
, "get write access");
4004 err
= ext4_journal_get_write_access(handle
, bh
);
4009 zero_user(page
, offset
, length
);
4011 BUFFER_TRACE(bh
, "zeroed end of block");
4014 if (ext4_should_journal_data(inode
)) {
4015 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
4017 if (ext4_should_order_data(inode
))
4018 err
= ext4_jbd2_file_inode(handle
, inode
);
4019 mark_buffer_dirty(bh
);
4024 page_cache_release(page
);
4029 * Probably it should be a library function... search for first non-zero word
4030 * or memcmp with zero_page, whatever is better for particular architecture.
4033 static inline int all_zeroes(__le32
*p
, __le32
*q
)
4042 * ext4_find_shared - find the indirect blocks for partial truncation.
4043 * @inode: inode in question
4044 * @depth: depth of the affected branch
4045 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4046 * @chain: place to store the pointers to partial indirect blocks
4047 * @top: place to the (detached) top of branch
4049 * This is a helper function used by ext4_truncate().
4051 * When we do truncate() we may have to clean the ends of several
4052 * indirect blocks but leave the blocks themselves alive. Block is
4053 * partially truncated if some data below the new i_size is refered
4054 * from it (and it is on the path to the first completely truncated
4055 * data block, indeed). We have to free the top of that path along
4056 * with everything to the right of the path. Since no allocation
4057 * past the truncation point is possible until ext4_truncate()
4058 * finishes, we may safely do the latter, but top of branch may
4059 * require special attention - pageout below the truncation point
4060 * might try to populate it.
4062 * We atomically detach the top of branch from the tree, store the
4063 * block number of its root in *@top, pointers to buffer_heads of
4064 * partially truncated blocks - in @chain[].bh and pointers to
4065 * their last elements that should not be removed - in
4066 * @chain[].p. Return value is the pointer to last filled element
4069 * The work left to caller to do the actual freeing of subtrees:
4070 * a) free the subtree starting from *@top
4071 * b) free the subtrees whose roots are stored in
4072 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4073 * c) free the subtrees growing from the inode past the @chain[0].
4074 * (no partially truncated stuff there). */
4076 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
4077 ext4_lblk_t offsets
[4], Indirect chain
[4],
4080 Indirect
*partial
, *p
;
4084 /* Make k index the deepest non-null offset + 1 */
4085 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
4087 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
4088 /* Writer: pointers */
4090 partial
= chain
+ k
-1;
4092 * If the branch acquired continuation since we've looked at it -
4093 * fine, it should all survive and (new) top doesn't belong to us.
4095 if (!partial
->key
&& *partial
->p
)
4098 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
4101 * OK, we've found the last block that must survive. The rest of our
4102 * branch should be detached before unlocking. However, if that rest
4103 * of branch is all ours and does not grow immediately from the inode
4104 * it's easier to cheat and just decrement partial->p.
4106 if (p
== chain
+ k
- 1 && p
> chain
) {
4110 /* Nope, don't do this in ext4. Must leave the tree intact */
4117 while (partial
> p
) {
4118 brelse(partial
->bh
);
4126 * Zero a number of block pointers in either an inode or an indirect block.
4127 * If we restart the transaction we must again get write access to the
4128 * indirect block for further modification.
4130 * We release `count' blocks on disk, but (last - first) may be greater
4131 * than `count' because there can be holes in there.
4133 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
4134 struct buffer_head
*bh
,
4135 ext4_fsblk_t block_to_free
,
4136 unsigned long count
, __le32
*first
,
4140 int flags
= EXT4_FREE_BLOCKS_FORGET
;
4142 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
4143 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4145 if (try_to_extend_transaction(handle
, inode
)) {
4147 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4148 ext4_handle_dirty_metadata(handle
, inode
, bh
);
4150 ext4_mark_inode_dirty(handle
, inode
);
4151 ext4_truncate_restart_trans(handle
, inode
,
4152 blocks_for_truncate(inode
));
4154 BUFFER_TRACE(bh
, "retaking write access");
4155 ext4_journal_get_write_access(handle
, bh
);
4159 for (p
= first
; p
< last
; p
++)
4162 ext4_free_blocks(handle
, inode
, 0, block_to_free
, count
, flags
);
4166 * ext4_free_data - free a list of data blocks
4167 * @handle: handle for this transaction
4168 * @inode: inode we are dealing with
4169 * @this_bh: indirect buffer_head which contains *@first and *@last
4170 * @first: array of block numbers
4171 * @last: points immediately past the end of array
4173 * We are freeing all blocks refered from that array (numbers are stored as
4174 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4176 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4177 * blocks are contiguous then releasing them at one time will only affect one
4178 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4179 * actually use a lot of journal space.
4181 * @this_bh will be %NULL if @first and @last point into the inode's direct
4184 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
4185 struct buffer_head
*this_bh
,
4186 __le32
*first
, __le32
*last
)
4188 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
4189 unsigned long count
= 0; /* Number of blocks in the run */
4190 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
4193 ext4_fsblk_t nr
; /* Current block # */
4194 __le32
*p
; /* Pointer into inode/ind
4195 for current block */
4198 if (this_bh
) { /* For indirect block */
4199 BUFFER_TRACE(this_bh
, "get_write_access");
4200 err
= ext4_journal_get_write_access(handle
, this_bh
);
4201 /* Important: if we can't update the indirect pointers
4202 * to the blocks, we can't free them. */
4207 for (p
= first
; p
< last
; p
++) {
4208 nr
= le32_to_cpu(*p
);
4210 /* accumulate blocks to free if they're contiguous */
4213 block_to_free_p
= p
;
4215 } else if (nr
== block_to_free
+ count
) {
4218 ext4_clear_blocks(handle
, inode
, this_bh
,
4220 count
, block_to_free_p
, p
);
4222 block_to_free_p
= p
;
4229 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
4230 count
, block_to_free_p
, p
);
4233 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
4236 * The buffer head should have an attached journal head at this
4237 * point. However, if the data is corrupted and an indirect
4238 * block pointed to itself, it would have been detached when
4239 * the block was cleared. Check for this instead of OOPSing.
4241 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
4242 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
4244 ext4_error(inode
->i_sb
, __func__
,
4245 "circular indirect block detected, "
4246 "inode=%lu, block=%llu",
4248 (unsigned long long) this_bh
->b_blocknr
);
4253 * ext4_free_branches - free an array of branches
4254 * @handle: JBD handle for this transaction
4255 * @inode: inode we are dealing with
4256 * @parent_bh: the buffer_head which contains *@first and *@last
4257 * @first: array of block numbers
4258 * @last: pointer immediately past the end of array
4259 * @depth: depth of the branches to free
4261 * We are freeing all blocks refered from these branches (numbers are
4262 * stored as little-endian 32-bit) and updating @inode->i_blocks
4265 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
4266 struct buffer_head
*parent_bh
,
4267 __le32
*first
, __le32
*last
, int depth
)
4272 if (ext4_handle_is_aborted(handle
))
4276 struct buffer_head
*bh
;
4277 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4279 while (--p
>= first
) {
4280 nr
= le32_to_cpu(*p
);
4282 continue; /* A hole */
4284 /* Go read the buffer for the next level down */
4285 bh
= sb_bread(inode
->i_sb
, nr
);
4288 * A read failure? Report error and clear slot
4292 ext4_error(inode
->i_sb
, "ext4_free_branches",
4293 "Read failure, inode=%lu, block=%llu",
4298 /* This zaps the entire block. Bottom up. */
4299 BUFFER_TRACE(bh
, "free child branches");
4300 ext4_free_branches(handle
, inode
, bh
,
4301 (__le32
*) bh
->b_data
,
4302 (__le32
*) bh
->b_data
+ addr_per_block
,
4306 * We've probably journalled the indirect block several
4307 * times during the truncate. But it's no longer
4308 * needed and we now drop it from the transaction via
4309 * jbd2_journal_revoke().
4311 * That's easy if it's exclusively part of this
4312 * transaction. But if it's part of the committing
4313 * transaction then jbd2_journal_forget() will simply
4314 * brelse() it. That means that if the underlying
4315 * block is reallocated in ext4_get_block(),
4316 * unmap_underlying_metadata() will find this block
4317 * and will try to get rid of it. damn, damn.
4319 * If this block has already been committed to the
4320 * journal, a revoke record will be written. And
4321 * revoke records must be emitted *before* clearing
4322 * this block's bit in the bitmaps.
4324 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
4327 * Everything below this this pointer has been
4328 * released. Now let this top-of-subtree go.
4330 * We want the freeing of this indirect block to be
4331 * atomic in the journal with the updating of the
4332 * bitmap block which owns it. So make some room in
4335 * We zero the parent pointer *after* freeing its
4336 * pointee in the bitmaps, so if extend_transaction()
4337 * for some reason fails to put the bitmap changes and
4338 * the release into the same transaction, recovery
4339 * will merely complain about releasing a free block,
4340 * rather than leaking blocks.
4342 if (ext4_handle_is_aborted(handle
))
4344 if (try_to_extend_transaction(handle
, inode
)) {
4345 ext4_mark_inode_dirty(handle
, inode
);
4346 ext4_truncate_restart_trans(handle
, inode
,
4347 blocks_for_truncate(inode
));
4350 ext4_free_blocks(handle
, inode
, 0, nr
, 1,
4351 EXT4_FREE_BLOCKS_METADATA
);
4355 * The block which we have just freed is
4356 * pointed to by an indirect block: journal it
4358 BUFFER_TRACE(parent_bh
, "get_write_access");
4359 if (!ext4_journal_get_write_access(handle
,
4362 BUFFER_TRACE(parent_bh
,
4363 "call ext4_handle_dirty_metadata");
4364 ext4_handle_dirty_metadata(handle
,
4371 /* We have reached the bottom of the tree. */
4372 BUFFER_TRACE(parent_bh
, "free data blocks");
4373 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
4377 int ext4_can_truncate(struct inode
*inode
)
4379 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
4381 if (S_ISREG(inode
->i_mode
))
4383 if (S_ISDIR(inode
->i_mode
))
4385 if (S_ISLNK(inode
->i_mode
))
4386 return !ext4_inode_is_fast_symlink(inode
);
4393 * We block out ext4_get_block() block instantiations across the entire
4394 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4395 * simultaneously on behalf of the same inode.
4397 * As we work through the truncate and commmit bits of it to the journal there
4398 * is one core, guiding principle: the file's tree must always be consistent on
4399 * disk. We must be able to restart the truncate after a crash.
4401 * The file's tree may be transiently inconsistent in memory (although it
4402 * probably isn't), but whenever we close off and commit a journal transaction,
4403 * the contents of (the filesystem + the journal) must be consistent and
4404 * restartable. It's pretty simple, really: bottom up, right to left (although
4405 * left-to-right works OK too).
4407 * Note that at recovery time, journal replay occurs *before* the restart of
4408 * truncate against the orphan inode list.
4410 * The committed inode has the new, desired i_size (which is the same as
4411 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4412 * that this inode's truncate did not complete and it will again call
4413 * ext4_truncate() to have another go. So there will be instantiated blocks
4414 * to the right of the truncation point in a crashed ext4 filesystem. But
4415 * that's fine - as long as they are linked from the inode, the post-crash
4416 * ext4_truncate() run will find them and release them.
4418 void ext4_truncate(struct inode
*inode
)
4421 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4422 __le32
*i_data
= ei
->i_data
;
4423 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4424 struct address_space
*mapping
= inode
->i_mapping
;
4425 ext4_lblk_t offsets
[4];
4430 ext4_lblk_t last_block
;
4431 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
4433 if (!ext4_can_truncate(inode
))
4436 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
4437 ei
->i_state
|= EXT4_STATE_DA_ALLOC_CLOSE
;
4439 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
4440 ext4_ext_truncate(inode
);
4444 handle
= start_transaction(inode
);
4446 return; /* AKPM: return what? */
4448 last_block
= (inode
->i_size
+ blocksize
-1)
4449 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
4451 if (inode
->i_size
& (blocksize
- 1))
4452 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
4455 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
4457 goto out_stop
; /* error */
4460 * OK. This truncate is going to happen. We add the inode to the
4461 * orphan list, so that if this truncate spans multiple transactions,
4462 * and we crash, we will resume the truncate when the filesystem
4463 * recovers. It also marks the inode dirty, to catch the new size.
4465 * Implication: the file must always be in a sane, consistent
4466 * truncatable state while each transaction commits.
4468 if (ext4_orphan_add(handle
, inode
))
4472 * From here we block out all ext4_get_block() callers who want to
4473 * modify the block allocation tree.
4475 down_write(&ei
->i_data_sem
);
4477 ext4_discard_preallocations(inode
);
4480 * The orphan list entry will now protect us from any crash which
4481 * occurs before the truncate completes, so it is now safe to propagate
4482 * the new, shorter inode size (held for now in i_size) into the
4483 * on-disk inode. We do this via i_disksize, which is the value which
4484 * ext4 *really* writes onto the disk inode.
4486 ei
->i_disksize
= inode
->i_size
;
4488 if (n
== 1) { /* direct blocks */
4489 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
4490 i_data
+ EXT4_NDIR_BLOCKS
);
4494 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
4495 /* Kill the top of shared branch (not detached) */
4497 if (partial
== chain
) {
4498 /* Shared branch grows from the inode */
4499 ext4_free_branches(handle
, inode
, NULL
,
4500 &nr
, &nr
+1, (chain
+n
-1) - partial
);
4503 * We mark the inode dirty prior to restart,
4504 * and prior to stop. No need for it here.
4507 /* Shared branch grows from an indirect block */
4508 BUFFER_TRACE(partial
->bh
, "get_write_access");
4509 ext4_free_branches(handle
, inode
, partial
->bh
,
4511 partial
->p
+1, (chain
+n
-1) - partial
);
4514 /* Clear the ends of indirect blocks on the shared branch */
4515 while (partial
> chain
) {
4516 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
4517 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
4518 (chain
+n
-1) - partial
);
4519 BUFFER_TRACE(partial
->bh
, "call brelse");
4520 brelse(partial
->bh
);
4524 /* Kill the remaining (whole) subtrees */
4525 switch (offsets
[0]) {
4527 nr
= i_data
[EXT4_IND_BLOCK
];
4529 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4530 i_data
[EXT4_IND_BLOCK
] = 0;
4532 case EXT4_IND_BLOCK
:
4533 nr
= i_data
[EXT4_DIND_BLOCK
];
4535 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4536 i_data
[EXT4_DIND_BLOCK
] = 0;
4538 case EXT4_DIND_BLOCK
:
4539 nr
= i_data
[EXT4_TIND_BLOCK
];
4541 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4542 i_data
[EXT4_TIND_BLOCK
] = 0;
4544 case EXT4_TIND_BLOCK
:
4548 up_write(&ei
->i_data_sem
);
4549 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4550 ext4_mark_inode_dirty(handle
, inode
);
4553 * In a multi-transaction truncate, we only make the final transaction
4557 ext4_handle_sync(handle
);
4560 * If this was a simple ftruncate(), and the file will remain alive
4561 * then we need to clear up the orphan record which we created above.
4562 * However, if this was a real unlink then we were called by
4563 * ext4_delete_inode(), and we allow that function to clean up the
4564 * orphan info for us.
4567 ext4_orphan_del(handle
, inode
);
4569 ext4_journal_stop(handle
);
4573 * ext4_get_inode_loc returns with an extra refcount against the inode's
4574 * underlying buffer_head on success. If 'in_mem' is true, we have all
4575 * data in memory that is needed to recreate the on-disk version of this
4578 static int __ext4_get_inode_loc(struct inode
*inode
,
4579 struct ext4_iloc
*iloc
, int in_mem
)
4581 struct ext4_group_desc
*gdp
;
4582 struct buffer_head
*bh
;
4583 struct super_block
*sb
= inode
->i_sb
;
4585 int inodes_per_block
, inode_offset
;
4588 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4591 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4592 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4597 * Figure out the offset within the block group inode table
4599 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4600 inode_offset
= ((inode
->i_ino
- 1) %
4601 EXT4_INODES_PER_GROUP(sb
));
4602 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4603 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4605 bh
= sb_getblk(sb
, block
);
4607 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
4608 "inode block - inode=%lu, block=%llu",
4609 inode
->i_ino
, block
);
4612 if (!buffer_uptodate(bh
)) {
4616 * If the buffer has the write error flag, we have failed
4617 * to write out another inode in the same block. In this
4618 * case, we don't have to read the block because we may
4619 * read the old inode data successfully.
4621 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4622 set_buffer_uptodate(bh
);
4624 if (buffer_uptodate(bh
)) {
4625 /* someone brought it uptodate while we waited */
4631 * If we have all information of the inode in memory and this
4632 * is the only valid inode in the block, we need not read the
4636 struct buffer_head
*bitmap_bh
;
4639 start
= inode_offset
& ~(inodes_per_block
- 1);
4641 /* Is the inode bitmap in cache? */
4642 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4647 * If the inode bitmap isn't in cache then the
4648 * optimisation may end up performing two reads instead
4649 * of one, so skip it.
4651 if (!buffer_uptodate(bitmap_bh
)) {
4655 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4656 if (i
== inode_offset
)
4658 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4662 if (i
== start
+ inodes_per_block
) {
4663 /* all other inodes are free, so skip I/O */
4664 memset(bh
->b_data
, 0, bh
->b_size
);
4665 set_buffer_uptodate(bh
);
4673 * If we need to do any I/O, try to pre-readahead extra
4674 * blocks from the inode table.
4676 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4677 ext4_fsblk_t b
, end
, table
;
4680 table
= ext4_inode_table(sb
, gdp
);
4681 /* s_inode_readahead_blks is always a power of 2 */
4682 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4685 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4686 num
= EXT4_INODES_PER_GROUP(sb
);
4687 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4688 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4689 num
-= ext4_itable_unused_count(sb
, gdp
);
4690 table
+= num
/ inodes_per_block
;
4694 sb_breadahead(sb
, b
++);
4698 * There are other valid inodes in the buffer, this inode
4699 * has in-inode xattrs, or we don't have this inode in memory.
4700 * Read the block from disk.
4703 bh
->b_end_io
= end_buffer_read_sync
;
4704 submit_bh(READ_META
, bh
);
4706 if (!buffer_uptodate(bh
)) {
4707 ext4_error(sb
, __func__
,
4708 "unable to read inode block - inode=%lu, "
4709 "block=%llu", inode
->i_ino
, block
);
4719 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4721 /* We have all inode data except xattrs in memory here. */
4722 return __ext4_get_inode_loc(inode
, iloc
,
4723 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4726 void ext4_set_inode_flags(struct inode
*inode
)
4728 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4730 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4731 if (flags
& EXT4_SYNC_FL
)
4732 inode
->i_flags
|= S_SYNC
;
4733 if (flags
& EXT4_APPEND_FL
)
4734 inode
->i_flags
|= S_APPEND
;
4735 if (flags
& EXT4_IMMUTABLE_FL
)
4736 inode
->i_flags
|= S_IMMUTABLE
;
4737 if (flags
& EXT4_NOATIME_FL
)
4738 inode
->i_flags
|= S_NOATIME
;
4739 if (flags
& EXT4_DIRSYNC_FL
)
4740 inode
->i_flags
|= S_DIRSYNC
;
4743 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4744 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4746 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4748 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4749 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4751 ei
->i_flags
|= EXT4_SYNC_FL
;
4752 if (flags
& S_APPEND
)
4753 ei
->i_flags
|= EXT4_APPEND_FL
;
4754 if (flags
& S_IMMUTABLE
)
4755 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4756 if (flags
& S_NOATIME
)
4757 ei
->i_flags
|= EXT4_NOATIME_FL
;
4758 if (flags
& S_DIRSYNC
)
4759 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4762 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4763 struct ext4_inode_info
*ei
)
4766 struct inode
*inode
= &(ei
->vfs_inode
);
4767 struct super_block
*sb
= inode
->i_sb
;
4769 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4770 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4771 /* we are using combined 48 bit field */
4772 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4773 le32_to_cpu(raw_inode
->i_blocks_lo
);
4774 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4775 /* i_blocks represent file system block size */
4776 return i_blocks
<< (inode
->i_blkbits
- 9);
4781 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4785 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4787 struct ext4_iloc iloc
;
4788 struct ext4_inode
*raw_inode
;
4789 struct ext4_inode_info
*ei
;
4790 struct inode
*inode
;
4791 journal_t
*journal
= EXT4_SB(sb
)->s_journal
;
4795 inode
= iget_locked(sb
, ino
);
4797 return ERR_PTR(-ENOMEM
);
4798 if (!(inode
->i_state
& I_NEW
))
4804 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4807 raw_inode
= ext4_raw_inode(&iloc
);
4808 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4809 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4810 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4811 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4812 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4813 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4815 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4818 ei
->i_dir_start_lookup
= 0;
4819 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4820 /* We now have enough fields to check if the inode was active or not.
4821 * This is needed because nfsd might try to access dead inodes
4822 * the test is that same one that e2fsck uses
4823 * NeilBrown 1999oct15
4825 if (inode
->i_nlink
== 0) {
4826 if (inode
->i_mode
== 0 ||
4827 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4828 /* this inode is deleted */
4832 /* The only unlinked inodes we let through here have
4833 * valid i_mode and are being read by the orphan
4834 * recovery code: that's fine, we're about to complete
4835 * the process of deleting those. */
4837 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4838 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4839 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4840 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
4842 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4843 inode
->i_size
= ext4_isize(raw_inode
);
4844 ei
->i_disksize
= inode
->i_size
;
4846 ei
->i_reserved_quota
= 0;
4848 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4849 ei
->i_block_group
= iloc
.block_group
;
4850 ei
->i_last_alloc_group
= ~0;
4852 * NOTE! The in-memory inode i_data array is in little-endian order
4853 * even on big-endian machines: we do NOT byteswap the block numbers!
4855 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4856 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4857 INIT_LIST_HEAD(&ei
->i_orphan
);
4860 * Set transaction id's of transactions that have to be committed
4861 * to finish f[data]sync. We set them to currently running transaction
4862 * as we cannot be sure that the inode or some of its metadata isn't
4863 * part of the transaction - the inode could have been reclaimed and
4864 * now it is reread from disk.
4867 transaction_t
*transaction
;
4870 spin_lock(&journal
->j_state_lock
);
4871 if (journal
->j_running_transaction
)
4872 transaction
= journal
->j_running_transaction
;
4874 transaction
= journal
->j_committing_transaction
;
4876 tid
= transaction
->t_tid
;
4878 tid
= journal
->j_commit_sequence
;
4879 spin_unlock(&journal
->j_state_lock
);
4880 ei
->i_sync_tid
= tid
;
4881 ei
->i_datasync_tid
= tid
;
4884 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4885 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4886 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4887 EXT4_INODE_SIZE(inode
->i_sb
)) {
4891 if (ei
->i_extra_isize
== 0) {
4892 /* The extra space is currently unused. Use it. */
4893 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4894 EXT4_GOOD_OLD_INODE_SIZE
;
4896 __le32
*magic
= (void *)raw_inode
+
4897 EXT4_GOOD_OLD_INODE_SIZE
+
4899 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4900 ei
->i_state
|= EXT4_STATE_XATTR
;
4903 ei
->i_extra_isize
= 0;
4905 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4906 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4907 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4908 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4910 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4911 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4912 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4914 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4918 if (ei
->i_file_acl
&&
4919 !ext4_data_block_valid(EXT4_SB(sb
), ei
->i_file_acl
, 1)) {
4920 ext4_error(sb
, __func__
,
4921 "bad extended attribute block %llu in inode #%lu",
4922 ei
->i_file_acl
, inode
->i_ino
);
4925 } else if (ei
->i_flags
& EXT4_EXTENTS_FL
) {
4926 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4927 (S_ISLNK(inode
->i_mode
) &&
4928 !ext4_inode_is_fast_symlink(inode
)))
4929 /* Validate extent which is part of inode */
4930 ret
= ext4_ext_check_inode(inode
);
4931 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4932 (S_ISLNK(inode
->i_mode
) &&
4933 !ext4_inode_is_fast_symlink(inode
))) {
4934 /* Validate block references which are part of inode */
4935 ret
= ext4_check_inode_blockref(inode
);
4940 if (S_ISREG(inode
->i_mode
)) {
4941 inode
->i_op
= &ext4_file_inode_operations
;
4942 inode
->i_fop
= &ext4_file_operations
;
4943 ext4_set_aops(inode
);
4944 } else if (S_ISDIR(inode
->i_mode
)) {
4945 inode
->i_op
= &ext4_dir_inode_operations
;
4946 inode
->i_fop
= &ext4_dir_operations
;
4947 } else if (S_ISLNK(inode
->i_mode
)) {
4948 if (ext4_inode_is_fast_symlink(inode
)) {
4949 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4950 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4951 sizeof(ei
->i_data
) - 1);
4953 inode
->i_op
= &ext4_symlink_inode_operations
;
4954 ext4_set_aops(inode
);
4956 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
4957 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
4958 inode
->i_op
= &ext4_special_inode_operations
;
4959 if (raw_inode
->i_block
[0])
4960 init_special_inode(inode
, inode
->i_mode
,
4961 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4963 init_special_inode(inode
, inode
->i_mode
,
4964 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4967 ext4_error(inode
->i_sb
, __func__
,
4968 "bogus i_mode (%o) for inode=%lu",
4969 inode
->i_mode
, inode
->i_ino
);
4973 ext4_set_inode_flags(inode
);
4974 unlock_new_inode(inode
);
4980 return ERR_PTR(ret
);
4983 static int ext4_inode_blocks_set(handle_t
*handle
,
4984 struct ext4_inode
*raw_inode
,
4985 struct ext4_inode_info
*ei
)
4987 struct inode
*inode
= &(ei
->vfs_inode
);
4988 u64 i_blocks
= inode
->i_blocks
;
4989 struct super_block
*sb
= inode
->i_sb
;
4991 if (i_blocks
<= ~0U) {
4993 * i_blocks can be represnted in a 32 bit variable
4994 * as multiple of 512 bytes
4996 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4997 raw_inode
->i_blocks_high
= 0;
4998 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
5001 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
5004 if (i_blocks
<= 0xffffffffffffULL
) {
5006 * i_blocks can be represented in a 48 bit variable
5007 * as multiple of 512 bytes
5009 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5010 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
5011 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
5013 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
5014 /* i_block is stored in file system block size */
5015 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
5016 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
5017 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
5023 * Post the struct inode info into an on-disk inode location in the
5024 * buffer-cache. This gobbles the caller's reference to the
5025 * buffer_head in the inode location struct.
5027 * The caller must have write access to iloc->bh.
5029 static int ext4_do_update_inode(handle_t
*handle
,
5030 struct inode
*inode
,
5031 struct ext4_iloc
*iloc
)
5033 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
5034 struct ext4_inode_info
*ei
= EXT4_I(inode
);
5035 struct buffer_head
*bh
= iloc
->bh
;
5036 int err
= 0, rc
, block
;
5038 /* For fields not not tracking in the in-memory inode,
5039 * initialise them to zero for new inodes. */
5040 if (ei
->i_state
& EXT4_STATE_NEW
)
5041 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
5043 ext4_get_inode_flags(ei
);
5044 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
5045 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5046 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
5047 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
5049 * Fix up interoperability with old kernels. Otherwise, old inodes get
5050 * re-used with the upper 16 bits of the uid/gid intact
5053 raw_inode
->i_uid_high
=
5054 cpu_to_le16(high_16_bits(inode
->i_uid
));
5055 raw_inode
->i_gid_high
=
5056 cpu_to_le16(high_16_bits(inode
->i_gid
));
5058 raw_inode
->i_uid_high
= 0;
5059 raw_inode
->i_gid_high
= 0;
5062 raw_inode
->i_uid_low
=
5063 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
5064 raw_inode
->i_gid_low
=
5065 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
5066 raw_inode
->i_uid_high
= 0;
5067 raw_inode
->i_gid_high
= 0;
5069 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
5071 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
5072 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
5073 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
5074 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
5076 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
5078 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
5079 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
);
5080 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
5081 cpu_to_le32(EXT4_OS_HURD
))
5082 raw_inode
->i_file_acl_high
=
5083 cpu_to_le16(ei
->i_file_acl
>> 32);
5084 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
5085 ext4_isize_set(raw_inode
, ei
->i_disksize
);
5086 if (ei
->i_disksize
> 0x7fffffffULL
) {
5087 struct super_block
*sb
= inode
->i_sb
;
5088 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
5089 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
5090 EXT4_SB(sb
)->s_es
->s_rev_level
==
5091 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
5092 /* If this is the first large file
5093 * created, add a flag to the superblock.
5095 err
= ext4_journal_get_write_access(handle
,
5096 EXT4_SB(sb
)->s_sbh
);
5099 ext4_update_dynamic_rev(sb
);
5100 EXT4_SET_RO_COMPAT_FEATURE(sb
,
5101 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
5103 ext4_handle_sync(handle
);
5104 err
= ext4_handle_dirty_metadata(handle
, inode
,
5105 EXT4_SB(sb
)->s_sbh
);
5108 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
5109 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
5110 if (old_valid_dev(inode
->i_rdev
)) {
5111 raw_inode
->i_block
[0] =
5112 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
5113 raw_inode
->i_block
[1] = 0;
5115 raw_inode
->i_block
[0] = 0;
5116 raw_inode
->i_block
[1] =
5117 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
5118 raw_inode
->i_block
[2] = 0;
5121 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5122 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
5124 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
5125 if (ei
->i_extra_isize
) {
5126 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5127 raw_inode
->i_version_hi
=
5128 cpu_to_le32(inode
->i_version
>> 32);
5129 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
5132 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
5133 rc
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
5136 ei
->i_state
&= ~EXT4_STATE_NEW
;
5138 ext4_update_inode_fsync_trans(handle
, inode
, 0);
5141 ext4_std_error(inode
->i_sb
, err
);
5146 * ext4_write_inode()
5148 * We are called from a few places:
5150 * - Within generic_file_write() for O_SYNC files.
5151 * Here, there will be no transaction running. We wait for any running
5152 * trasnaction to commit.
5154 * - Within sys_sync(), kupdate and such.
5155 * We wait on commit, if tol to.
5157 * - Within prune_icache() (PF_MEMALLOC == true)
5158 * Here we simply return. We can't afford to block kswapd on the
5161 * In all cases it is actually safe for us to return without doing anything,
5162 * because the inode has been copied into a raw inode buffer in
5163 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5166 * Note that we are absolutely dependent upon all inode dirtiers doing the
5167 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5168 * which we are interested.
5170 * It would be a bug for them to not do this. The code:
5172 * mark_inode_dirty(inode)
5174 * inode->i_size = expr;
5176 * is in error because a kswapd-driven write_inode() could occur while
5177 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5178 * will no longer be on the superblock's dirty inode list.
5180 int ext4_write_inode(struct inode
*inode
, int wait
)
5184 if (current
->flags
& PF_MEMALLOC
)
5187 if (EXT4_SB(inode
->i_sb
)->s_journal
) {
5188 if (ext4_journal_current_handle()) {
5189 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5197 err
= ext4_force_commit(inode
->i_sb
);
5199 struct ext4_iloc iloc
;
5201 err
= ext4_get_inode_loc(inode
, &iloc
);
5205 sync_dirty_buffer(iloc
.bh
);
5206 if (buffer_req(iloc
.bh
) && !buffer_uptodate(iloc
.bh
)) {
5207 ext4_error(inode
->i_sb
, __func__
,
5208 "IO error syncing inode, "
5209 "inode=%lu, block=%llu",
5211 (unsigned long long)iloc
.bh
->b_blocknr
);
5221 * Called from notify_change.
5223 * We want to trap VFS attempts to truncate the file as soon as
5224 * possible. In particular, we want to make sure that when the VFS
5225 * shrinks i_size, we put the inode on the orphan list and modify
5226 * i_disksize immediately, so that during the subsequent flushing of
5227 * dirty pages and freeing of disk blocks, we can guarantee that any
5228 * commit will leave the blocks being flushed in an unused state on
5229 * disk. (On recovery, the inode will get truncated and the blocks will
5230 * be freed, so we have a strong guarantee that no future commit will
5231 * leave these blocks visible to the user.)
5233 * Another thing we have to assure is that if we are in ordered mode
5234 * and inode is still attached to the committing transaction, we must
5235 * we start writeout of all the dirty pages which are being truncated.
5236 * This way we are sure that all the data written in the previous
5237 * transaction are already on disk (truncate waits for pages under
5240 * Called with inode->i_mutex down.
5242 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
5244 struct inode
*inode
= dentry
->d_inode
;
5246 const unsigned int ia_valid
= attr
->ia_valid
;
5248 error
= inode_change_ok(inode
, attr
);
5252 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
5253 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
5256 /* (user+group)*(old+new) structure, inode write (sb,
5257 * inode block, ? - but truncate inode update has it) */
5258 handle
= ext4_journal_start(inode
, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode
->i_sb
)+
5259 EXT4_MAXQUOTAS_DEL_BLOCKS(inode
->i_sb
))+3);
5260 if (IS_ERR(handle
)) {
5261 error
= PTR_ERR(handle
);
5264 error
= vfs_dq_transfer(inode
, attr
) ? -EDQUOT
: 0;
5266 ext4_journal_stop(handle
);
5269 /* Update corresponding info in inode so that everything is in
5270 * one transaction */
5271 if (attr
->ia_valid
& ATTR_UID
)
5272 inode
->i_uid
= attr
->ia_uid
;
5273 if (attr
->ia_valid
& ATTR_GID
)
5274 inode
->i_gid
= attr
->ia_gid
;
5275 error
= ext4_mark_inode_dirty(handle
, inode
);
5276 ext4_journal_stop(handle
);
5279 if (attr
->ia_valid
& ATTR_SIZE
) {
5280 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
5281 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5283 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
5290 if (S_ISREG(inode
->i_mode
) &&
5291 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
5294 handle
= ext4_journal_start(inode
, 3);
5295 if (IS_ERR(handle
)) {
5296 error
= PTR_ERR(handle
);
5300 error
= ext4_orphan_add(handle
, inode
);
5301 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
5302 rc
= ext4_mark_inode_dirty(handle
, inode
);
5305 ext4_journal_stop(handle
);
5307 if (ext4_should_order_data(inode
)) {
5308 error
= ext4_begin_ordered_truncate(inode
,
5311 /* Do as much error cleanup as possible */
5312 handle
= ext4_journal_start(inode
, 3);
5313 if (IS_ERR(handle
)) {
5314 ext4_orphan_del(NULL
, inode
);
5317 ext4_orphan_del(handle
, inode
);
5318 ext4_journal_stop(handle
);
5324 rc
= inode_setattr(inode
, attr
);
5326 /* If inode_setattr's call to ext4_truncate failed to get a
5327 * transaction handle at all, we need to clean up the in-core
5328 * orphan list manually. */
5330 ext4_orphan_del(NULL
, inode
);
5332 if (!rc
&& (ia_valid
& ATTR_MODE
))
5333 rc
= ext4_acl_chmod(inode
);
5336 ext4_std_error(inode
->i_sb
, error
);
5342 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
5345 struct inode
*inode
;
5346 unsigned long delalloc_blocks
;
5348 inode
= dentry
->d_inode
;
5349 generic_fillattr(inode
, stat
);
5352 * We can't update i_blocks if the block allocation is delayed
5353 * otherwise in the case of system crash before the real block
5354 * allocation is done, we will have i_blocks inconsistent with
5355 * on-disk file blocks.
5356 * We always keep i_blocks updated together with real
5357 * allocation. But to not confuse with user, stat
5358 * will return the blocks that include the delayed allocation
5359 * blocks for this file.
5361 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
5362 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
5363 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
5365 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
5369 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
5374 /* if nrblocks are contiguous */
5377 * With N contiguous data blocks, it need at most
5378 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5379 * 2 dindirect blocks
5382 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
5383 return indirects
+ 3;
5386 * if nrblocks are not contiguous, worse case, each block touch
5387 * a indirect block, and each indirect block touch a double indirect
5388 * block, plus a triple indirect block
5390 indirects
= nrblocks
* 2 + 1;
5394 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5396 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
5397 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
5398 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
5402 * Account for index blocks, block groups bitmaps and block group
5403 * descriptor blocks if modify datablocks and index blocks
5404 * worse case, the indexs blocks spread over different block groups
5406 * If datablocks are discontiguous, they are possible to spread over
5407 * different block groups too. If they are contiuguous, with flexbg,
5408 * they could still across block group boundary.
5410 * Also account for superblock, inode, quota and xattr blocks
5412 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5414 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
5420 * How many index blocks need to touch to modify nrblocks?
5421 * The "Chunk" flag indicating whether the nrblocks is
5422 * physically contiguous on disk
5424 * For Direct IO and fallocate, they calls get_block to allocate
5425 * one single extent at a time, so they could set the "Chunk" flag
5427 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
5432 * Now let's see how many group bitmaps and group descriptors need
5442 if (groups
> ngroups
)
5444 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
5445 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
5447 /* bitmaps and block group descriptor blocks */
5448 ret
+= groups
+ gdpblocks
;
5450 /* Blocks for super block, inode, quota and xattr blocks */
5451 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
5457 * Calulate the total number of credits to reserve to fit
5458 * the modification of a single pages into a single transaction,
5459 * which may include multiple chunks of block allocations.
5461 * This could be called via ext4_write_begin()
5463 * We need to consider the worse case, when
5464 * one new block per extent.
5466 int ext4_writepage_trans_blocks(struct inode
*inode
)
5468 int bpp
= ext4_journal_blocks_per_page(inode
);
5471 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
5473 /* Account for data blocks for journalled mode */
5474 if (ext4_should_journal_data(inode
))
5480 * Calculate the journal credits for a chunk of data modification.
5482 * This is called from DIO, fallocate or whoever calling
5483 * ext4_get_blocks() to map/allocate a chunk of contiguous disk blocks.
5485 * journal buffers for data blocks are not included here, as DIO
5486 * and fallocate do no need to journal data buffers.
5488 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
5490 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
5494 * The caller must have previously called ext4_reserve_inode_write().
5495 * Give this, we know that the caller already has write access to iloc->bh.
5497 int ext4_mark_iloc_dirty(handle_t
*handle
,
5498 struct inode
*inode
, struct ext4_iloc
*iloc
)
5502 if (test_opt(inode
->i_sb
, I_VERSION
))
5503 inode_inc_iversion(inode
);
5505 /* the do_update_inode consumes one bh->b_count */
5508 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5509 err
= ext4_do_update_inode(handle
, inode
, iloc
);
5515 * On success, We end up with an outstanding reference count against
5516 * iloc->bh. This _must_ be cleaned up later.
5520 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
5521 struct ext4_iloc
*iloc
)
5525 err
= ext4_get_inode_loc(inode
, iloc
);
5527 BUFFER_TRACE(iloc
->bh
, "get_write_access");
5528 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
5534 ext4_std_error(inode
->i_sb
, err
);
5539 * Expand an inode by new_extra_isize bytes.
5540 * Returns 0 on success or negative error number on failure.
5542 static int ext4_expand_extra_isize(struct inode
*inode
,
5543 unsigned int new_extra_isize
,
5544 struct ext4_iloc iloc
,
5547 struct ext4_inode
*raw_inode
;
5548 struct ext4_xattr_ibody_header
*header
;
5549 struct ext4_xattr_entry
*entry
;
5551 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
5554 raw_inode
= ext4_raw_inode(&iloc
);
5556 header
= IHDR(inode
, raw_inode
);
5557 entry
= IFIRST(header
);
5559 /* No extended attributes present */
5560 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
5561 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
5562 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5564 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5568 /* try to expand with EAs present */
5569 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5574 * What we do here is to mark the in-core inode as clean with respect to inode
5575 * dirtiness (it may still be data-dirty).
5576 * This means that the in-core inode may be reaped by prune_icache
5577 * without having to perform any I/O. This is a very good thing,
5578 * because *any* task may call prune_icache - even ones which
5579 * have a transaction open against a different journal.
5581 * Is this cheating? Not really. Sure, we haven't written the
5582 * inode out, but prune_icache isn't a user-visible syncing function.
5583 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5584 * we start and wait on commits.
5586 * Is this efficient/effective? Well, we're being nice to the system
5587 * by cleaning up our inodes proactively so they can be reaped
5588 * without I/O. But we are potentially leaving up to five seconds'
5589 * worth of inodes floating about which prune_icache wants us to
5590 * write out. One way to fix that would be to get prune_icache()
5591 * to do a write_super() to free up some memory. It has the desired
5594 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5596 struct ext4_iloc iloc
;
5597 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5598 static unsigned int mnt_count
;
5602 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5603 if (ext4_handle_valid(handle
) &&
5604 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5605 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
5607 * We need extra buffer credits since we may write into EA block
5608 * with this same handle. If journal_extend fails, then it will
5609 * only result in a minor loss of functionality for that inode.
5610 * If this is felt to be critical, then e2fsck should be run to
5611 * force a large enough s_min_extra_isize.
5613 if ((jbd2_journal_extend(handle
,
5614 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5615 ret
= ext4_expand_extra_isize(inode
,
5616 sbi
->s_want_extra_isize
,
5619 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
5621 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5622 ext4_warning(inode
->i_sb
, __func__
,
5623 "Unable to expand inode %lu. Delete"
5624 " some EAs or run e2fsck.",
5627 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5633 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5638 * ext4_dirty_inode() is called from __mark_inode_dirty()
5640 * We're really interested in the case where a file is being extended.
5641 * i_size has been changed by generic_commit_write() and we thus need
5642 * to include the updated inode in the current transaction.
5644 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
5645 * are allocated to the file.
5647 * If the inode is marked synchronous, we don't honour that here - doing
5648 * so would cause a commit on atime updates, which we don't bother doing.
5649 * We handle synchronous inodes at the highest possible level.
5651 void ext4_dirty_inode(struct inode
*inode
)
5655 handle
= ext4_journal_start(inode
, 2);
5659 ext4_mark_inode_dirty(handle
, inode
);
5661 ext4_journal_stop(handle
);
5668 * Bind an inode's backing buffer_head into this transaction, to prevent
5669 * it from being flushed to disk early. Unlike
5670 * ext4_reserve_inode_write, this leaves behind no bh reference and
5671 * returns no iloc structure, so the caller needs to repeat the iloc
5672 * lookup to mark the inode dirty later.
5674 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5676 struct ext4_iloc iloc
;
5680 err
= ext4_get_inode_loc(inode
, &iloc
);
5682 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5683 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5685 err
= ext4_handle_dirty_metadata(handle
,
5691 ext4_std_error(inode
->i_sb
, err
);
5696 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5703 * We have to be very careful here: changing a data block's
5704 * journaling status dynamically is dangerous. If we write a
5705 * data block to the journal, change the status and then delete
5706 * that block, we risk forgetting to revoke the old log record
5707 * from the journal and so a subsequent replay can corrupt data.
5708 * So, first we make sure that the journal is empty and that
5709 * nobody is changing anything.
5712 journal
= EXT4_JOURNAL(inode
);
5715 if (is_journal_aborted(journal
))
5718 jbd2_journal_lock_updates(journal
);
5719 jbd2_journal_flush(journal
);
5722 * OK, there are no updates running now, and all cached data is
5723 * synced to disk. We are now in a completely consistent state
5724 * which doesn't have anything in the journal, and we know that
5725 * no filesystem updates are running, so it is safe to modify
5726 * the inode's in-core data-journaling state flag now.
5730 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
5732 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
5733 ext4_set_aops(inode
);
5735 jbd2_journal_unlock_updates(journal
);
5737 /* Finally we can mark the inode as dirty. */
5739 handle
= ext4_journal_start(inode
, 1);
5741 return PTR_ERR(handle
);
5743 err
= ext4_mark_inode_dirty(handle
, inode
);
5744 ext4_handle_sync(handle
);
5745 ext4_journal_stop(handle
);
5746 ext4_std_error(inode
->i_sb
, err
);
5751 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5753 return !buffer_mapped(bh
);
5756 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5758 struct page
*page
= vmf
->page
;
5763 struct file
*file
= vma
->vm_file
;
5764 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5765 struct address_space
*mapping
= inode
->i_mapping
;
5768 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5769 * get i_mutex because we are already holding mmap_sem.
5771 down_read(&inode
->i_alloc_sem
);
5772 size
= i_size_read(inode
);
5773 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5774 || !PageUptodate(page
)) {
5775 /* page got truncated from under us? */
5779 if (PageMappedToDisk(page
))
5782 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5783 len
= size
& ~PAGE_CACHE_MASK
;
5785 len
= PAGE_CACHE_SIZE
;
5789 * return if we have all the buffers mapped. This avoid
5790 * the need to call write_begin/write_end which does a
5791 * journal_start/journal_stop which can block and take
5794 if (page_has_buffers(page
)) {
5795 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5796 ext4_bh_unmapped
)) {
5803 * OK, we need to fill the hole... Do write_begin write_end
5804 * to do block allocation/reservation.We are not holding
5805 * inode.i__mutex here. That allow * parallel write_begin,
5806 * write_end call. lock_page prevent this from happening
5807 * on the same page though
5809 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5810 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5813 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5814 len
, len
, page
, fsdata
);
5820 ret
= VM_FAULT_SIGBUS
;
5821 up_read(&inode
->i_alloc_sem
);