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 "ext4_jbd2.h"
43 #include "ext4_extents.h"
45 #define MPAGE_DA_EXTENT_TAIL 0x01
47 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
50 return jbd2_journal_begin_ordered_truncate(
51 EXT4_SB(inode
->i_sb
)->s_journal
,
52 &EXT4_I(inode
)->jinode
,
56 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
59 * Test whether an inode is a fast symlink.
61 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
63 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
64 (inode
->i_sb
->s_blocksize
>> 9) : 0;
66 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
70 * The ext4 forget function must perform a revoke if we are freeing data
71 * which has been journaled. Metadata (eg. indirect blocks) must be
72 * revoked in all cases.
74 * "bh" may be NULL: a metadata block may have been freed from memory
75 * but there may still be a record of it in the journal, and that record
76 * still needs to be revoked.
78 * If the handle isn't valid we're not journaling so there's nothing to do.
80 int ext4_forget(handle_t
*handle
, int is_metadata
, struct inode
*inode
,
81 struct buffer_head
*bh
, ext4_fsblk_t blocknr
)
85 if (!ext4_handle_valid(handle
))
90 BUFFER_TRACE(bh
, "enter");
92 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
94 bh
, is_metadata
, inode
->i_mode
,
95 test_opt(inode
->i_sb
, DATA_FLAGS
));
97 /* Never use the revoke function if we are doing full data
98 * journaling: there is no need to, and a V1 superblock won't
99 * support it. Otherwise, only skip the revoke on un-journaled
102 if (test_opt(inode
->i_sb
, DATA_FLAGS
) == EXT4_MOUNT_JOURNAL_DATA
||
103 (!is_metadata
&& !ext4_should_journal_data(inode
))) {
105 BUFFER_TRACE(bh
, "call jbd2_journal_forget");
106 return ext4_journal_forget(handle
, bh
);
112 * data!=journal && (is_metadata || should_journal_data(inode))
114 BUFFER_TRACE(bh
, "call ext4_journal_revoke");
115 err
= ext4_journal_revoke(handle
, blocknr
, bh
);
117 ext4_abort(inode
->i_sb
, __func__
,
118 "error %d when attempting revoke", err
);
119 BUFFER_TRACE(bh
, "exit");
124 * Work out how many blocks we need to proceed with the next chunk of a
125 * truncate transaction.
127 static unsigned long blocks_for_truncate(struct inode
*inode
)
131 needed
= inode
->i_blocks
>> (inode
->i_sb
->s_blocksize_bits
- 9);
133 /* Give ourselves just enough room to cope with inodes in which
134 * i_blocks is corrupt: we've seen disk corruptions in the past
135 * which resulted in random data in an inode which looked enough
136 * like a regular file for ext4 to try to delete it. Things
137 * will go a bit crazy if that happens, but at least we should
138 * try not to panic the whole kernel. */
142 /* But we need to bound the transaction so we don't overflow the
144 if (needed
> EXT4_MAX_TRANS_DATA
)
145 needed
= EXT4_MAX_TRANS_DATA
;
147 return EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + needed
;
151 * Truncate transactions can be complex and absolutely huge. So we need to
152 * be able to restart the transaction at a conventient checkpoint to make
153 * sure we don't overflow the journal.
155 * start_transaction gets us a new handle for a truncate transaction,
156 * and extend_transaction tries to extend the existing one a bit. If
157 * extend fails, we need to propagate the failure up and restart the
158 * transaction in the top-level truncate loop. --sct
160 static handle_t
*start_transaction(struct inode
*inode
)
164 result
= ext4_journal_start(inode
, blocks_for_truncate(inode
));
168 ext4_std_error(inode
->i_sb
, PTR_ERR(result
));
173 * Try to extend this transaction for the purposes of truncation.
175 * Returns 0 if we managed to create more room. If we can't create more
176 * room, and the transaction must be restarted we return 1.
178 static int try_to_extend_transaction(handle_t
*handle
, struct inode
*inode
)
180 if (!ext4_handle_valid(handle
))
182 if (ext4_handle_has_enough_credits(handle
, EXT4_RESERVE_TRANS_BLOCKS
+1))
184 if (!ext4_journal_extend(handle
, blocks_for_truncate(inode
)))
190 * Restart the transaction associated with *handle. This does a commit,
191 * so before we call here everything must be consistently dirtied against
194 static int ext4_journal_test_restart(handle_t
*handle
, struct inode
*inode
)
196 BUG_ON(EXT4_JOURNAL(inode
) == NULL
);
197 jbd_debug(2, "restarting handle %p\n", handle
);
198 return ext4_journal_restart(handle
, blocks_for_truncate(inode
));
202 * Called at the last iput() if i_nlink is zero.
204 void ext4_delete_inode(struct inode
*inode
)
209 if (ext4_should_order_data(inode
))
210 ext4_begin_ordered_truncate(inode
, 0);
211 truncate_inode_pages(&inode
->i_data
, 0);
213 if (is_bad_inode(inode
))
216 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
217 if (IS_ERR(handle
)) {
218 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
220 * If we're going to skip the normal cleanup, we still need to
221 * make sure that the in-core orphan linked list is properly
224 ext4_orphan_del(NULL
, inode
);
229 ext4_handle_sync(handle
);
231 err
= ext4_mark_inode_dirty(handle
, inode
);
233 ext4_warning(inode
->i_sb
, __func__
,
234 "couldn't mark inode dirty (err %d)", err
);
238 ext4_truncate(inode
);
241 * ext4_ext_truncate() doesn't reserve any slop when it
242 * restarts journal transactions; therefore there may not be
243 * enough credits left in the handle to remove the inode from
244 * the orphan list and set the dtime field.
246 if (!ext4_handle_has_enough_credits(handle
, 3)) {
247 err
= ext4_journal_extend(handle
, 3);
249 err
= ext4_journal_restart(handle
, 3);
251 ext4_warning(inode
->i_sb
, __func__
,
252 "couldn't extend journal (err %d)", err
);
254 ext4_journal_stop(handle
);
260 * Kill off the orphan record which ext4_truncate created.
261 * AKPM: I think this can be inside the above `if'.
262 * Note that ext4_orphan_del() has to be able to cope with the
263 * deletion of a non-existent orphan - this is because we don't
264 * know if ext4_truncate() actually created an orphan record.
265 * (Well, we could do this if we need to, but heck - it works)
267 ext4_orphan_del(handle
, inode
);
268 EXT4_I(inode
)->i_dtime
= get_seconds();
271 * One subtle ordering requirement: if anything has gone wrong
272 * (transaction abort, IO errors, whatever), then we can still
273 * do these next steps (the fs will already have been marked as
274 * having errors), but we can't free the inode if the mark_dirty
277 if (ext4_mark_inode_dirty(handle
, inode
))
278 /* If that failed, just do the required in-core inode clear. */
281 ext4_free_inode(handle
, inode
);
282 ext4_journal_stop(handle
);
285 clear_inode(inode
); /* We must guarantee clearing of inode... */
291 struct buffer_head
*bh
;
294 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
296 p
->key
= *(p
->p
= v
);
301 * ext4_block_to_path - parse the block number into array of offsets
302 * @inode: inode in question (we are only interested in its superblock)
303 * @i_block: block number to be parsed
304 * @offsets: array to store the offsets in
305 * @boundary: set this non-zero if the referred-to block is likely to be
306 * followed (on disk) by an indirect block.
308 * To store the locations of file's data ext4 uses a data structure common
309 * for UNIX filesystems - tree of pointers anchored in the inode, with
310 * data blocks at leaves and indirect blocks in intermediate nodes.
311 * This function translates the block number into path in that tree -
312 * return value is the path length and @offsets[n] is the offset of
313 * pointer to (n+1)th node in the nth one. If @block is out of range
314 * (negative or too large) warning is printed and zero returned.
316 * Note: function doesn't find node addresses, so no IO is needed. All
317 * we need to know is the capacity of indirect blocks (taken from the
322 * Portability note: the last comparison (check that we fit into triple
323 * indirect block) is spelled differently, because otherwise on an
324 * architecture with 32-bit longs and 8Kb pages we might get into trouble
325 * if our filesystem had 8Kb blocks. We might use long long, but that would
326 * kill us on x86. Oh, well, at least the sign propagation does not matter -
327 * i_block would have to be negative in the very beginning, so we would not
331 static int ext4_block_to_path(struct inode
*inode
,
333 ext4_lblk_t offsets
[4], int *boundary
)
335 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
336 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
337 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
338 indirect_blocks
= ptrs
,
339 double_blocks
= (1 << (ptrs_bits
* 2));
344 ext4_warning(inode
->i_sb
, "ext4_block_to_path", "block < 0");
345 } else if (i_block
< direct_blocks
) {
346 offsets
[n
++] = i_block
;
347 final
= direct_blocks
;
348 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
349 offsets
[n
++] = EXT4_IND_BLOCK
;
350 offsets
[n
++] = i_block
;
352 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
353 offsets
[n
++] = EXT4_DIND_BLOCK
;
354 offsets
[n
++] = i_block
>> ptrs_bits
;
355 offsets
[n
++] = i_block
& (ptrs
- 1);
357 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
358 offsets
[n
++] = EXT4_TIND_BLOCK
;
359 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
360 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
361 offsets
[n
++] = i_block
& (ptrs
- 1);
364 ext4_warning(inode
->i_sb
, "ext4_block_to_path",
365 "block %lu > max in inode %lu",
366 i_block
+ direct_blocks
+
367 indirect_blocks
+ double_blocks
, inode
->i_ino
);
370 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
375 * ext4_get_branch - read the chain of indirect blocks leading to data
376 * @inode: inode in question
377 * @depth: depth of the chain (1 - direct pointer, etc.)
378 * @offsets: offsets of pointers in inode/indirect blocks
379 * @chain: place to store the result
380 * @err: here we store the error value
382 * Function fills the array of triples <key, p, bh> and returns %NULL
383 * if everything went OK or the pointer to the last filled triple
384 * (incomplete one) otherwise. Upon the return chain[i].key contains
385 * the number of (i+1)-th block in the chain (as it is stored in memory,
386 * i.e. little-endian 32-bit), chain[i].p contains the address of that
387 * number (it points into struct inode for i==0 and into the bh->b_data
388 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
389 * block for i>0 and NULL for i==0. In other words, it holds the block
390 * numbers of the chain, addresses they were taken from (and where we can
391 * verify that chain did not change) and buffer_heads hosting these
394 * Function stops when it stumbles upon zero pointer (absent block)
395 * (pointer to last triple returned, *@err == 0)
396 * or when it gets an IO error reading an indirect block
397 * (ditto, *@err == -EIO)
398 * or when it reads all @depth-1 indirect blocks successfully and finds
399 * the whole chain, all way to the data (returns %NULL, *err == 0).
401 * Need to be called with
402 * down_read(&EXT4_I(inode)->i_data_sem)
404 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
405 ext4_lblk_t
*offsets
,
406 Indirect chain
[4], int *err
)
408 struct super_block
*sb
= inode
->i_sb
;
410 struct buffer_head
*bh
;
413 /* i_data is not going away, no lock needed */
414 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
418 bh
= sb_bread(sb
, le32_to_cpu(p
->key
));
421 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
435 * ext4_find_near - find a place for allocation with sufficient locality
437 * @ind: descriptor of indirect block.
439 * This function returns the preferred place for block allocation.
440 * It is used when heuristic for sequential allocation fails.
442 * + if there is a block to the left of our position - allocate near it.
443 * + if pointer will live in indirect block - allocate near that block.
444 * + if pointer will live in inode - allocate in the same
447 * In the latter case we colour the starting block by the callers PID to
448 * prevent it from clashing with concurrent allocations for a different inode
449 * in the same block group. The PID is used here so that functionally related
450 * files will be close-by on-disk.
452 * Caller must make sure that @ind is valid and will stay that way.
454 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
456 struct ext4_inode_info
*ei
= EXT4_I(inode
);
457 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
459 ext4_fsblk_t bg_start
;
460 ext4_fsblk_t last_block
;
461 ext4_grpblk_t colour
;
462 ext4_group_t block_group
;
463 int flex_size
= ext4_flex_bg_size(EXT4_SB(inode
->i_sb
));
465 /* Try to find previous block */
466 for (p
= ind
->p
- 1; p
>= start
; p
--) {
468 return le32_to_cpu(*p
);
471 /* No such thing, so let's try location of indirect block */
473 return ind
->bh
->b_blocknr
;
476 * It is going to be referred to from the inode itself? OK, just put it
477 * into the same cylinder group then.
479 block_group
= ei
->i_block_group
;
480 if (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) {
481 block_group
&= ~(flex_size
-1);
482 if (S_ISREG(inode
->i_mode
))
485 bg_start
= ext4_group_first_block_no(inode
->i_sb
, block_group
);
486 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
489 * If we are doing delayed allocation, we don't need take
490 * colour into account.
492 if (test_opt(inode
->i_sb
, DELALLOC
))
495 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
496 colour
= (current
->pid
% 16) *
497 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
499 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
500 return bg_start
+ colour
;
504 * ext4_find_goal - find a preferred place for allocation.
506 * @block: block we want
507 * @partial: pointer to the last triple within a chain
509 * Normally this function find the preferred place for block allocation,
512 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
516 * XXX need to get goal block from mballoc's data structures
519 return ext4_find_near(inode
, partial
);
523 * ext4_blks_to_allocate: Look up the block map and count the number
524 * of direct blocks need to be allocated for the given branch.
526 * @branch: chain of indirect blocks
527 * @k: number of blocks need for indirect blocks
528 * @blks: number of data blocks to be mapped.
529 * @blocks_to_boundary: the offset in the indirect block
531 * return the total number of blocks to be allocate, including the
532 * direct and indirect blocks.
534 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned int blks
,
535 int blocks_to_boundary
)
537 unsigned int count
= 0;
540 * Simple case, [t,d]Indirect block(s) has not allocated yet
541 * then it's clear blocks on that path have not allocated
544 /* right now we don't handle cross boundary allocation */
545 if (blks
< blocks_to_boundary
+ 1)
548 count
+= blocks_to_boundary
+ 1;
553 while (count
< blks
&& count
<= blocks_to_boundary
&&
554 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
561 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
562 * @indirect_blks: the number of blocks need to allocate for indirect
565 * @new_blocks: on return it will store the new block numbers for
566 * the indirect blocks(if needed) and the first direct block,
567 * @blks: on return it will store the total number of allocated
570 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
571 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
572 int indirect_blks
, int blks
,
573 ext4_fsblk_t new_blocks
[4], int *err
)
575 struct ext4_allocation_request ar
;
577 unsigned long count
= 0, blk_allocated
= 0;
579 ext4_fsblk_t current_block
= 0;
583 * Here we try to allocate the requested multiple blocks at once,
584 * on a best-effort basis.
585 * To build a branch, we should allocate blocks for
586 * the indirect blocks(if not allocated yet), and at least
587 * the first direct block of this branch. That's the
588 * minimum number of blocks need to allocate(required)
590 /* first we try to allocate the indirect blocks */
591 target
= indirect_blks
;
594 /* allocating blocks for indirect blocks and direct blocks */
595 current_block
= ext4_new_meta_blocks(handle
, inode
,
601 /* allocate blocks for indirect blocks */
602 while (index
< indirect_blks
&& count
) {
603 new_blocks
[index
++] = current_block
++;
608 * save the new block number
609 * for the first direct block
611 new_blocks
[index
] = current_block
;
612 printk(KERN_INFO
"%s returned more blocks than "
613 "requested\n", __func__
);
619 target
= blks
- count
;
620 blk_allocated
= count
;
623 /* Now allocate data blocks */
624 memset(&ar
, 0, sizeof(ar
));
629 if (S_ISREG(inode
->i_mode
))
630 /* enable in-core preallocation only for regular files */
631 ar
.flags
= EXT4_MB_HINT_DATA
;
633 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
635 if (*err
&& (target
== blks
)) {
637 * if the allocation failed and we didn't allocate
643 if (target
== blks
) {
645 * save the new block number
646 * for the first direct block
648 new_blocks
[index
] = current_block
;
650 blk_allocated
+= ar
.len
;
653 /* total number of blocks allocated for direct blocks */
658 for (i
= 0; i
< index
; i
++)
659 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
664 * ext4_alloc_branch - allocate and set up a chain of blocks.
666 * @indirect_blks: number of allocated indirect blocks
667 * @blks: number of allocated direct blocks
668 * @offsets: offsets (in the blocks) to store the pointers to next.
669 * @branch: place to store the chain in.
671 * This function allocates blocks, zeroes out all but the last one,
672 * links them into chain and (if we are synchronous) writes them to disk.
673 * In other words, it prepares a branch that can be spliced onto the
674 * inode. It stores the information about that chain in the branch[], in
675 * the same format as ext4_get_branch() would do. We are calling it after
676 * we had read the existing part of chain and partial points to the last
677 * triple of that (one with zero ->key). Upon the exit we have the same
678 * picture as after the successful ext4_get_block(), except that in one
679 * place chain is disconnected - *branch->p is still zero (we did not
680 * set the last link), but branch->key contains the number that should
681 * be placed into *branch->p to fill that gap.
683 * If allocation fails we free all blocks we've allocated (and forget
684 * their buffer_heads) and return the error value the from failed
685 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
686 * as described above and return 0.
688 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
689 ext4_lblk_t iblock
, int indirect_blks
,
690 int *blks
, ext4_fsblk_t goal
,
691 ext4_lblk_t
*offsets
, Indirect
*branch
)
693 int blocksize
= inode
->i_sb
->s_blocksize
;
696 struct buffer_head
*bh
;
698 ext4_fsblk_t new_blocks
[4];
699 ext4_fsblk_t current_block
;
701 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
702 *blks
, new_blocks
, &err
);
706 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
708 * metadata blocks and data blocks are allocated.
710 for (n
= 1; n
<= indirect_blks
; n
++) {
712 * Get buffer_head for parent block, zero it out
713 * and set the pointer to new one, then send
716 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
719 BUFFER_TRACE(bh
, "call get_create_access");
720 err
= ext4_journal_get_create_access(handle
, bh
);
727 memset(bh
->b_data
, 0, blocksize
);
728 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
729 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
730 *branch
[n
].p
= branch
[n
].key
;
731 if (n
== indirect_blks
) {
732 current_block
= new_blocks
[n
];
734 * End of chain, update the last new metablock of
735 * the chain to point to the new allocated
736 * data blocks numbers
738 for (i
=1; i
< num
; i
++)
739 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
741 BUFFER_TRACE(bh
, "marking uptodate");
742 set_buffer_uptodate(bh
);
745 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
746 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
753 /* Allocation failed, free what we already allocated */
754 for (i
= 1; i
<= n
; i
++) {
755 BUFFER_TRACE(branch
[i
].bh
, "call jbd2_journal_forget");
756 ext4_journal_forget(handle
, branch
[i
].bh
);
758 for (i
= 0; i
< indirect_blks
; i
++)
759 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
761 ext4_free_blocks(handle
, inode
, new_blocks
[i
], num
, 0);
767 * ext4_splice_branch - splice the allocated branch onto inode.
769 * @block: (logical) number of block we are adding
770 * @chain: chain of indirect blocks (with a missing link - see
772 * @where: location of missing link
773 * @num: number of indirect blocks we are adding
774 * @blks: number of direct blocks we are adding
776 * This function fills the missing link and does all housekeeping needed in
777 * inode (->i_blocks, etc.). In case of success we end up with the full
778 * chain to new block and return 0.
780 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
781 ext4_lblk_t block
, Indirect
*where
, int num
, int blks
)
785 ext4_fsblk_t current_block
;
788 * If we're splicing into a [td]indirect block (as opposed to the
789 * inode) then we need to get write access to the [td]indirect block
793 BUFFER_TRACE(where
->bh
, "get_write_access");
794 err
= ext4_journal_get_write_access(handle
, where
->bh
);
800 *where
->p
= where
->key
;
803 * Update the host buffer_head or inode to point to more just allocated
804 * direct blocks blocks
806 if (num
== 0 && blks
> 1) {
807 current_block
= le32_to_cpu(where
->key
) + 1;
808 for (i
= 1; i
< blks
; i
++)
809 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
812 /* We are done with atomic stuff, now do the rest of housekeeping */
814 inode
->i_ctime
= ext4_current_time(inode
);
815 ext4_mark_inode_dirty(handle
, inode
);
817 /* had we spliced it onto indirect block? */
820 * If we spliced it onto an indirect block, we haven't
821 * altered the inode. Note however that if it is being spliced
822 * onto an indirect block at the very end of the file (the
823 * file is growing) then we *will* alter the inode to reflect
824 * the new i_size. But that is not done here - it is done in
825 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
827 jbd_debug(5, "splicing indirect only\n");
828 BUFFER_TRACE(where
->bh
, "call ext4_handle_dirty_metadata");
829 err
= ext4_handle_dirty_metadata(handle
, inode
, where
->bh
);
834 * OK, we spliced it into the inode itself on a direct block.
835 * Inode was dirtied above.
837 jbd_debug(5, "splicing direct\n");
842 for (i
= 1; i
<= num
; i
++) {
843 BUFFER_TRACE(where
[i
].bh
, "call jbd2_journal_forget");
844 ext4_journal_forget(handle
, where
[i
].bh
);
845 ext4_free_blocks(handle
, inode
,
846 le32_to_cpu(where
[i
-1].key
), 1, 0);
848 ext4_free_blocks(handle
, inode
, le32_to_cpu(where
[num
].key
), blks
, 0);
854 * Allocation strategy is simple: if we have to allocate something, we will
855 * have to go the whole way to leaf. So let's do it before attaching anything
856 * to tree, set linkage between the newborn blocks, write them if sync is
857 * required, recheck the path, free and repeat if check fails, otherwise
858 * set the last missing link (that will protect us from any truncate-generated
859 * removals - all blocks on the path are immune now) and possibly force the
860 * write on the parent block.
861 * That has a nice additional property: no special recovery from the failed
862 * allocations is needed - we simply release blocks and do not touch anything
863 * reachable from inode.
865 * `handle' can be NULL if create == 0.
867 * return > 0, # of blocks mapped or allocated.
868 * return = 0, if plain lookup failed.
869 * return < 0, error case.
872 * Need to be called with
873 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
874 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
876 static int ext4_get_blocks_handle(handle_t
*handle
, struct inode
*inode
,
877 ext4_lblk_t iblock
, unsigned int maxblocks
,
878 struct buffer_head
*bh_result
,
879 int create
, int extend_disksize
)
882 ext4_lblk_t offsets
[4];
887 int blocks_to_boundary
= 0;
889 struct ext4_inode_info
*ei
= EXT4_I(inode
);
891 ext4_fsblk_t first_block
= 0;
895 J_ASSERT(!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
));
896 J_ASSERT(handle
!= NULL
|| create
== 0);
897 depth
= ext4_block_to_path(inode
, iblock
, offsets
,
898 &blocks_to_boundary
);
903 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
905 /* Simplest case - block found, no allocation needed */
907 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
908 clear_buffer_new(bh_result
);
911 while (count
< maxblocks
&& count
<= blocks_to_boundary
) {
914 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
916 if (blk
== first_block
+ count
)
924 /* Next simple case - plain lookup or failed read of indirect block */
925 if (!create
|| err
== -EIO
)
929 * Okay, we need to do block allocation.
931 goal
= ext4_find_goal(inode
, iblock
, partial
);
933 /* the number of blocks need to allocate for [d,t]indirect blocks */
934 indirect_blks
= (chain
+ depth
) - partial
- 1;
937 * Next look up the indirect map to count the totoal number of
938 * direct blocks to allocate for this branch.
940 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
941 maxblocks
, blocks_to_boundary
);
943 * Block out ext4_truncate while we alter the tree
945 err
= ext4_alloc_branch(handle
, inode
, iblock
, indirect_blks
,
947 offsets
+ (partial
- chain
), partial
);
950 * The ext4_splice_branch call will free and forget any buffers
951 * on the new chain if there is a failure, but that risks using
952 * up transaction credits, especially for bitmaps where the
953 * credits cannot be returned. Can we handle this somehow? We
954 * may need to return -EAGAIN upwards in the worst case. --sct
957 err
= ext4_splice_branch(handle
, inode
, iblock
,
958 partial
, indirect_blks
, count
);
960 * i_disksize growing is protected by i_data_sem. Don't forget to
961 * protect it if you're about to implement concurrent
962 * ext4_get_block() -bzzz
964 if (!err
&& extend_disksize
) {
965 disksize
= ((loff_t
) iblock
+ count
) << inode
->i_blkbits
;
966 if (disksize
> i_size_read(inode
))
967 disksize
= i_size_read(inode
);
968 if (disksize
> ei
->i_disksize
)
969 ei
->i_disksize
= disksize
;
974 set_buffer_new(bh_result
);
976 map_bh(bh_result
, inode
->i_sb
, le32_to_cpu(chain
[depth
-1].key
));
977 if (count
> blocks_to_boundary
)
978 set_buffer_boundary(bh_result
);
980 /* Clean up and exit */
981 partial
= chain
+ depth
- 1; /* the whole chain */
983 while (partial
> chain
) {
984 BUFFER_TRACE(partial
->bh
, "call brelse");
988 BUFFER_TRACE(bh_result
, "returned");
993 qsize_t
ext4_get_reserved_space(struct inode
*inode
)
995 unsigned long long total
;
997 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
998 total
= EXT4_I(inode
)->i_reserved_data_blocks
+
999 EXT4_I(inode
)->i_reserved_meta_blocks
;
1000 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1005 * Calculate the number of metadata blocks need to reserve
1006 * to allocate @blocks for non extent file based file
1008 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
, int blocks
)
1010 int icap
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
1011 int ind_blks
, dind_blks
, tind_blks
;
1013 /* number of new indirect blocks needed */
1014 ind_blks
= (blocks
+ icap
- 1) / icap
;
1016 dind_blks
= (ind_blks
+ icap
- 1) / icap
;
1020 return ind_blks
+ dind_blks
+ tind_blks
;
1024 * Calculate the number of metadata blocks need to reserve
1025 * to allocate given number of blocks
1027 static int ext4_calc_metadata_amount(struct inode
*inode
, int blocks
)
1032 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
1033 return ext4_ext_calc_metadata_amount(inode
, blocks
);
1035 return ext4_indirect_calc_metadata_amount(inode
, blocks
);
1038 static void ext4_da_update_reserve_space(struct inode
*inode
, int used
)
1040 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1041 int total
, mdb
, mdb_free
;
1043 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1044 /* recalculate the number of metablocks still need to be reserved */
1045 total
= EXT4_I(inode
)->i_reserved_data_blocks
- used
;
1046 mdb
= ext4_calc_metadata_amount(inode
, total
);
1048 /* figure out how many metablocks to release */
1049 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1050 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1053 /* Account for allocated meta_blocks */
1054 mdb_free
-= EXT4_I(inode
)->i_allocated_meta_blocks
;
1056 /* update fs dirty blocks counter */
1057 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1058 EXT4_I(inode
)->i_allocated_meta_blocks
= 0;
1059 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1062 /* update per-inode reservations */
1063 BUG_ON(used
> EXT4_I(inode
)->i_reserved_data_blocks
);
1064 EXT4_I(inode
)->i_reserved_data_blocks
-= used
;
1065 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1068 * free those over-booking quota for metadata blocks
1071 vfs_dq_release_reservation_block(inode
, mdb_free
);
1074 * If we have done all the pending block allocations and if
1075 * there aren't any writers on the inode, we can discard the
1076 * inode's preallocations.
1078 if (!total
&& (atomic_read(&inode
->i_writecount
) == 0))
1079 ext4_discard_preallocations(inode
);
1083 * The ext4_get_blocks_wrap() function try to look up the requested blocks,
1084 * and returns if the blocks are already mapped.
1086 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1087 * and store the allocated blocks in the result buffer head and mark it
1090 * If file type is extents based, it will call ext4_ext_get_blocks(),
1091 * Otherwise, call with ext4_get_blocks_handle() to handle indirect mapping
1094 * On success, it returns the number of blocks being mapped or allocate.
1095 * if create==0 and the blocks are pre-allocated and uninitialized block,
1096 * the result buffer head is unmapped. If the create ==1, it will make sure
1097 * the buffer head is mapped.
1099 * It returns 0 if plain look up failed (blocks have not been allocated), in
1100 * that casem, buffer head is unmapped
1102 * It returns the error in case of allocation failure.
1104 int ext4_get_blocks_wrap(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1105 unsigned int max_blocks
, struct buffer_head
*bh
,
1106 int create
, int extend_disksize
, int flag
)
1110 clear_buffer_mapped(bh
);
1113 * Try to see if we can get the block without requesting
1114 * for new file system block.
1116 down_read((&EXT4_I(inode
)->i_data_sem
));
1117 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1118 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1121 retval
= ext4_get_blocks_handle(handle
,
1122 inode
, block
, max_blocks
, bh
, 0, 0);
1124 up_read((&EXT4_I(inode
)->i_data_sem
));
1126 /* If it is only a block(s) look up */
1131 * Returns if the blocks have already allocated
1133 * Note that if blocks have been preallocated
1134 * ext4_ext_get_block() returns th create = 0
1135 * with buffer head unmapped.
1137 if (retval
> 0 && buffer_mapped(bh
))
1141 * New blocks allocate and/or writing to uninitialized extent
1142 * will possibly result in updating i_data, so we take
1143 * the write lock of i_data_sem, and call get_blocks()
1144 * with create == 1 flag.
1146 down_write((&EXT4_I(inode
)->i_data_sem
));
1149 * if the caller is from delayed allocation writeout path
1150 * we have already reserved fs blocks for allocation
1151 * let the underlying get_block() function know to
1152 * avoid double accounting
1155 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1157 * We need to check for EXT4 here because migrate
1158 * could have changed the inode type in between
1160 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1161 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1162 bh
, create
, extend_disksize
);
1164 retval
= ext4_get_blocks_handle(handle
, inode
, block
,
1165 max_blocks
, bh
, create
, extend_disksize
);
1167 if (retval
> 0 && buffer_new(bh
)) {
1169 * We allocated new blocks which will result in
1170 * i_data's format changing. Force the migrate
1171 * to fail by clearing migrate flags
1173 EXT4_I(inode
)->i_flags
= EXT4_I(inode
)->i_flags
&
1179 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1181 * Update reserved blocks/metadata blocks
1182 * after successful block allocation
1183 * which were deferred till now
1185 if ((retval
> 0) && buffer_delay(bh
))
1186 ext4_da_update_reserve_space(inode
, retval
);
1189 up_write((&EXT4_I(inode
)->i_data_sem
));
1193 /* Maximum number of blocks we map for direct IO at once. */
1194 #define DIO_MAX_BLOCKS 4096
1196 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1197 struct buffer_head
*bh_result
, int create
)
1199 handle_t
*handle
= ext4_journal_current_handle();
1200 int ret
= 0, started
= 0;
1201 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1204 if (create
&& !handle
) {
1205 /* Direct IO write... */
1206 if (max_blocks
> DIO_MAX_BLOCKS
)
1207 max_blocks
= DIO_MAX_BLOCKS
;
1208 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1209 handle
= ext4_journal_start(inode
, dio_credits
);
1210 if (IS_ERR(handle
)) {
1211 ret
= PTR_ERR(handle
);
1217 ret
= ext4_get_blocks_wrap(handle
, inode
, iblock
,
1218 max_blocks
, bh_result
, create
, 0, 0);
1220 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1224 ext4_journal_stop(handle
);
1230 * `handle' can be NULL if create is zero
1232 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1233 ext4_lblk_t block
, int create
, int *errp
)
1235 struct buffer_head dummy
;
1238 J_ASSERT(handle
!= NULL
|| create
== 0);
1241 dummy
.b_blocknr
= -1000;
1242 buffer_trace_init(&dummy
.b_history
);
1243 err
= ext4_get_blocks_wrap(handle
, inode
, block
, 1,
1244 &dummy
, create
, 1, 0);
1246 * ext4_get_blocks_handle() returns number of blocks
1247 * mapped. 0 in case of a HOLE.
1255 if (!err
&& buffer_mapped(&dummy
)) {
1256 struct buffer_head
*bh
;
1257 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1262 if (buffer_new(&dummy
)) {
1263 J_ASSERT(create
!= 0);
1264 J_ASSERT(handle
!= NULL
);
1267 * Now that we do not always journal data, we should
1268 * keep in mind whether this should always journal the
1269 * new buffer as metadata. For now, regular file
1270 * writes use ext4_get_block instead, so it's not a
1274 BUFFER_TRACE(bh
, "call get_create_access");
1275 fatal
= ext4_journal_get_create_access(handle
, bh
);
1276 if (!fatal
&& !buffer_uptodate(bh
)) {
1277 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1278 set_buffer_uptodate(bh
);
1281 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1282 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1286 BUFFER_TRACE(bh
, "not a new buffer");
1299 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1300 ext4_lblk_t block
, int create
, int *err
)
1302 struct buffer_head
*bh
;
1304 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1307 if (buffer_uptodate(bh
))
1309 ll_rw_block(READ_META
, 1, &bh
);
1311 if (buffer_uptodate(bh
))
1318 static int walk_page_buffers(handle_t
*handle
,
1319 struct buffer_head
*head
,
1323 int (*fn
)(handle_t
*handle
,
1324 struct buffer_head
*bh
))
1326 struct buffer_head
*bh
;
1327 unsigned block_start
, block_end
;
1328 unsigned blocksize
= head
->b_size
;
1330 struct buffer_head
*next
;
1332 for (bh
= head
, block_start
= 0;
1333 ret
== 0 && (bh
!= head
|| !block_start
);
1334 block_start
= block_end
, bh
= next
)
1336 next
= bh
->b_this_page
;
1337 block_end
= block_start
+ blocksize
;
1338 if (block_end
<= from
|| block_start
>= to
) {
1339 if (partial
&& !buffer_uptodate(bh
))
1343 err
= (*fn
)(handle
, bh
);
1351 * To preserve ordering, it is essential that the hole instantiation and
1352 * the data write be encapsulated in a single transaction. We cannot
1353 * close off a transaction and start a new one between the ext4_get_block()
1354 * and the commit_write(). So doing the jbd2_journal_start at the start of
1355 * prepare_write() is the right place.
1357 * Also, this function can nest inside ext4_writepage() ->
1358 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1359 * has generated enough buffer credits to do the whole page. So we won't
1360 * block on the journal in that case, which is good, because the caller may
1363 * By accident, ext4 can be reentered when a transaction is open via
1364 * quota file writes. If we were to commit the transaction while thus
1365 * reentered, there can be a deadlock - we would be holding a quota
1366 * lock, and the commit would never complete if another thread had a
1367 * transaction open and was blocking on the quota lock - a ranking
1370 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1371 * will _not_ run commit under these circumstances because handle->h_ref
1372 * is elevated. We'll still have enough credits for the tiny quotafile
1375 static int do_journal_get_write_access(handle_t
*handle
,
1376 struct buffer_head
*bh
)
1378 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1380 return ext4_journal_get_write_access(handle
, bh
);
1383 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1384 loff_t pos
, unsigned len
, unsigned flags
,
1385 struct page
**pagep
, void **fsdata
)
1387 struct inode
*inode
= mapping
->host
;
1388 int ret
, needed_blocks
= ext4_writepage_trans_blocks(inode
);
1395 trace_mark(ext4_write_begin
,
1396 "dev %s ino %lu pos %llu len %u flags %u",
1397 inode
->i_sb
->s_id
, inode
->i_ino
,
1398 (unsigned long long) pos
, len
, flags
);
1399 index
= pos
>> PAGE_CACHE_SHIFT
;
1400 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1404 handle
= ext4_journal_start(inode
, needed_blocks
);
1405 if (IS_ERR(handle
)) {
1406 ret
= PTR_ERR(handle
);
1410 /* We cannot recurse into the filesystem as the transaction is already
1412 flags
|= AOP_FLAG_NOFS
;
1414 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1416 ext4_journal_stop(handle
);
1422 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1425 if (!ret
&& ext4_should_journal_data(inode
)) {
1426 ret
= walk_page_buffers(handle
, page_buffers(page
),
1427 from
, to
, NULL
, do_journal_get_write_access
);
1432 ext4_journal_stop(handle
);
1433 page_cache_release(page
);
1435 * block_write_begin may have instantiated a few blocks
1436 * outside i_size. Trim these off again. Don't need
1437 * i_size_read because we hold i_mutex.
1439 if (pos
+ len
> inode
->i_size
)
1440 vmtruncate(inode
, inode
->i_size
);
1443 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1449 /* For write_end() in data=journal mode */
1450 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1452 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1454 set_buffer_uptodate(bh
);
1455 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1459 * We need to pick up the new inode size which generic_commit_write gave us
1460 * `file' can be NULL - eg, when called from page_symlink().
1462 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1463 * buffers are managed internally.
1465 static int ext4_ordered_write_end(struct file
*file
,
1466 struct address_space
*mapping
,
1467 loff_t pos
, unsigned len
, unsigned copied
,
1468 struct page
*page
, void *fsdata
)
1470 handle_t
*handle
= ext4_journal_current_handle();
1471 struct inode
*inode
= mapping
->host
;
1474 trace_mark(ext4_ordered_write_end
,
1475 "dev %s ino %lu pos %llu len %u copied %u",
1476 inode
->i_sb
->s_id
, inode
->i_ino
,
1477 (unsigned long long) pos
, len
, copied
);
1478 ret
= ext4_jbd2_file_inode(handle
, inode
);
1483 new_i_size
= pos
+ copied
;
1484 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1485 ext4_update_i_disksize(inode
, new_i_size
);
1486 /* We need to mark inode dirty even if
1487 * new_i_size is less that inode->i_size
1488 * bu greater than i_disksize.(hint delalloc)
1490 ext4_mark_inode_dirty(handle
, inode
);
1493 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
1499 ret2
= ext4_journal_stop(handle
);
1503 return ret
? ret
: copied
;
1506 static int ext4_writeback_write_end(struct file
*file
,
1507 struct address_space
*mapping
,
1508 loff_t pos
, unsigned len
, unsigned copied
,
1509 struct page
*page
, void *fsdata
)
1511 handle_t
*handle
= ext4_journal_current_handle();
1512 struct inode
*inode
= mapping
->host
;
1516 trace_mark(ext4_writeback_write_end
,
1517 "dev %s ino %lu pos %llu len %u copied %u",
1518 inode
->i_sb
->s_id
, inode
->i_ino
,
1519 (unsigned long long) pos
, len
, copied
);
1520 new_i_size
= pos
+ copied
;
1521 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1522 ext4_update_i_disksize(inode
, new_i_size
);
1523 /* We need to mark inode dirty even if
1524 * new_i_size is less that inode->i_size
1525 * bu greater than i_disksize.(hint delalloc)
1527 ext4_mark_inode_dirty(handle
, inode
);
1530 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
1536 ret2
= ext4_journal_stop(handle
);
1540 return ret
? ret
: copied
;
1543 static int ext4_journalled_write_end(struct file
*file
,
1544 struct address_space
*mapping
,
1545 loff_t pos
, unsigned len
, unsigned copied
,
1546 struct page
*page
, void *fsdata
)
1548 handle_t
*handle
= ext4_journal_current_handle();
1549 struct inode
*inode
= mapping
->host
;
1555 trace_mark(ext4_journalled_write_end
,
1556 "dev %s ino %lu pos %llu len %u copied %u",
1557 inode
->i_sb
->s_id
, inode
->i_ino
,
1558 (unsigned long long) pos
, len
, copied
);
1559 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1563 if (!PageUptodate(page
))
1565 page_zero_new_buffers(page
, from
+copied
, to
);
1568 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1569 to
, &partial
, write_end_fn
);
1571 SetPageUptodate(page
);
1572 new_i_size
= pos
+ copied
;
1573 if (new_i_size
> inode
->i_size
)
1574 i_size_write(inode
, pos
+copied
);
1575 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1576 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1577 ext4_update_i_disksize(inode
, new_i_size
);
1578 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1584 ret2
= ext4_journal_stop(handle
);
1587 page_cache_release(page
);
1589 return ret
? ret
: copied
;
1592 static int ext4_da_reserve_space(struct inode
*inode
, int nrblocks
)
1595 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1596 unsigned long md_needed
, mdblocks
, total
= 0;
1599 * recalculate the amount of metadata blocks to reserve
1600 * in order to allocate nrblocks
1601 * worse case is one extent per block
1604 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1605 total
= EXT4_I(inode
)->i_reserved_data_blocks
+ nrblocks
;
1606 mdblocks
= ext4_calc_metadata_amount(inode
, total
);
1607 BUG_ON(mdblocks
< EXT4_I(inode
)->i_reserved_meta_blocks
);
1609 md_needed
= mdblocks
- EXT4_I(inode
)->i_reserved_meta_blocks
;
1610 total
= md_needed
+ nrblocks
;
1613 * Make quota reservation here to prevent quota overflow
1614 * later. Real quota accounting is done at pages writeout
1617 if (vfs_dq_reserve_block(inode
, total
)) {
1618 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1622 if (ext4_claim_free_blocks(sbi
, total
)) {
1623 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1624 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1628 vfs_dq_release_reservation_block(inode
, total
);
1631 EXT4_I(inode
)->i_reserved_data_blocks
+= nrblocks
;
1632 EXT4_I(inode
)->i_reserved_meta_blocks
= mdblocks
;
1634 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1635 return 0; /* success */
1638 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1640 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1641 int total
, mdb
, mdb_free
, release
;
1644 return; /* Nothing to release, exit */
1646 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1648 if (!EXT4_I(inode
)->i_reserved_data_blocks
) {
1650 * if there is no reserved blocks, but we try to free some
1651 * then the counter is messed up somewhere.
1652 * but since this function is called from invalidate
1653 * page, it's harmless to return without any action
1655 printk(KERN_INFO
"ext4 delalloc try to release %d reserved "
1656 "blocks for inode %lu, but there is no reserved "
1657 "data blocks\n", to_free
, inode
->i_ino
);
1658 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1662 /* recalculate the number of metablocks still need to be reserved */
1663 total
= EXT4_I(inode
)->i_reserved_data_blocks
- to_free
;
1664 mdb
= ext4_calc_metadata_amount(inode
, total
);
1666 /* figure out how many metablocks to release */
1667 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1668 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1670 release
= to_free
+ mdb_free
;
1672 /* update fs dirty blocks counter for truncate case */
1673 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, release
);
1675 /* update per-inode reservations */
1676 BUG_ON(to_free
> EXT4_I(inode
)->i_reserved_data_blocks
);
1677 EXT4_I(inode
)->i_reserved_data_blocks
-= to_free
;
1679 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1680 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1681 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1683 vfs_dq_release_reservation_block(inode
, release
);
1686 static void ext4_da_page_release_reservation(struct page
*page
,
1687 unsigned long offset
)
1690 struct buffer_head
*head
, *bh
;
1691 unsigned int curr_off
= 0;
1693 head
= page_buffers(page
);
1696 unsigned int next_off
= curr_off
+ bh
->b_size
;
1698 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1700 clear_buffer_delay(bh
);
1702 curr_off
= next_off
;
1703 } while ((bh
= bh
->b_this_page
) != head
);
1704 ext4_da_release_space(page
->mapping
->host
, to_release
);
1708 * Delayed allocation stuff
1711 struct mpage_da_data
{
1712 struct inode
*inode
;
1713 sector_t b_blocknr
; /* start block number of extent */
1714 size_t b_size
; /* size of extent */
1715 unsigned long b_state
; /* state of the extent */
1716 unsigned long first_page
, next_page
; /* extent of pages */
1717 struct writeback_control
*wbc
;
1724 * mpage_da_submit_io - walks through extent of pages and try to write
1725 * them with writepage() call back
1727 * @mpd->inode: inode
1728 * @mpd->first_page: first page of the extent
1729 * @mpd->next_page: page after the last page of the extent
1731 * By the time mpage_da_submit_io() is called we expect all blocks
1732 * to be allocated. this may be wrong if allocation failed.
1734 * As pages are already locked by write_cache_pages(), we can't use it
1736 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1739 struct pagevec pvec
;
1740 unsigned long index
, end
;
1741 int ret
= 0, err
, nr_pages
, i
;
1742 struct inode
*inode
= mpd
->inode
;
1743 struct address_space
*mapping
= inode
->i_mapping
;
1745 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1747 * We need to start from the first_page to the next_page - 1
1748 * to make sure we also write the mapped dirty buffer_heads.
1749 * If we look at mpd->b_blocknr we would only be looking
1750 * at the currently mapped buffer_heads.
1752 index
= mpd
->first_page
;
1753 end
= mpd
->next_page
- 1;
1755 pagevec_init(&pvec
, 0);
1756 while (index
<= end
) {
1757 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1760 for (i
= 0; i
< nr_pages
; i
++) {
1761 struct page
*page
= pvec
.pages
[i
];
1763 index
= page
->index
;
1768 BUG_ON(!PageLocked(page
));
1769 BUG_ON(PageWriteback(page
));
1771 pages_skipped
= mpd
->wbc
->pages_skipped
;
1772 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
1773 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
1775 * have successfully written the page
1776 * without skipping the same
1778 mpd
->pages_written
++;
1780 * In error case, we have to continue because
1781 * remaining pages are still locked
1782 * XXX: unlock and re-dirty them?
1787 pagevec_release(&pvec
);
1793 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
1795 * @mpd->inode - inode to walk through
1796 * @exbh->b_blocknr - first block on a disk
1797 * @exbh->b_size - amount of space in bytes
1798 * @logical - first logical block to start assignment with
1800 * the function goes through all passed space and put actual disk
1801 * block numbers into buffer heads, dropping BH_Delay
1803 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
1804 struct buffer_head
*exbh
)
1806 struct inode
*inode
= mpd
->inode
;
1807 struct address_space
*mapping
= inode
->i_mapping
;
1808 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
1809 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
1810 struct buffer_head
*head
, *bh
;
1812 struct pagevec pvec
;
1815 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1816 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1817 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1819 pagevec_init(&pvec
, 0);
1821 while (index
<= end
) {
1822 /* XXX: optimize tail */
1823 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1826 for (i
= 0; i
< nr_pages
; i
++) {
1827 struct page
*page
= pvec
.pages
[i
];
1829 index
= page
->index
;
1834 BUG_ON(!PageLocked(page
));
1835 BUG_ON(PageWriteback(page
));
1836 BUG_ON(!page_has_buffers(page
));
1838 bh
= page_buffers(page
);
1841 /* skip blocks out of the range */
1843 if (cur_logical
>= logical
)
1846 } while ((bh
= bh
->b_this_page
) != head
);
1849 if (cur_logical
>= logical
+ blocks
)
1851 if (buffer_delay(bh
)) {
1852 bh
->b_blocknr
= pblock
;
1853 clear_buffer_delay(bh
);
1854 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
1855 } else if (buffer_unwritten(bh
)) {
1856 bh
->b_blocknr
= pblock
;
1857 clear_buffer_unwritten(bh
);
1858 set_buffer_mapped(bh
);
1860 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
1861 } else if (buffer_mapped(bh
))
1862 BUG_ON(bh
->b_blocknr
!= pblock
);
1866 } while ((bh
= bh
->b_this_page
) != head
);
1868 pagevec_release(&pvec
);
1874 * __unmap_underlying_blocks - just a helper function to unmap
1875 * set of blocks described by @bh
1877 static inline void __unmap_underlying_blocks(struct inode
*inode
,
1878 struct buffer_head
*bh
)
1880 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
1883 blocks
= bh
->b_size
>> inode
->i_blkbits
;
1884 for (i
= 0; i
< blocks
; i
++)
1885 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
1888 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
1889 sector_t logical
, long blk_cnt
)
1893 struct pagevec pvec
;
1894 struct inode
*inode
= mpd
->inode
;
1895 struct address_space
*mapping
= inode
->i_mapping
;
1897 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1898 end
= (logical
+ blk_cnt
- 1) >>
1899 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1900 while (index
<= end
) {
1901 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1904 for (i
= 0; i
< nr_pages
; i
++) {
1905 struct page
*page
= pvec
.pages
[i
];
1906 index
= page
->index
;
1911 BUG_ON(!PageLocked(page
));
1912 BUG_ON(PageWriteback(page
));
1913 block_invalidatepage(page
, 0);
1914 ClearPageUptodate(page
);
1921 static void ext4_print_free_blocks(struct inode
*inode
)
1923 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1924 printk(KERN_EMERG
"Total free blocks count %lld\n",
1925 ext4_count_free_blocks(inode
->i_sb
));
1926 printk(KERN_EMERG
"Free/Dirty block details\n");
1927 printk(KERN_EMERG
"free_blocks=%lld\n",
1928 (long long)percpu_counter_sum(&sbi
->s_freeblocks_counter
));
1929 printk(KERN_EMERG
"dirty_blocks=%lld\n",
1930 (long long)percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
1931 printk(KERN_EMERG
"Block reservation details\n");
1932 printk(KERN_EMERG
"i_reserved_data_blocks=%u\n",
1933 EXT4_I(inode
)->i_reserved_data_blocks
);
1934 printk(KERN_EMERG
"i_reserved_meta_blocks=%u\n",
1935 EXT4_I(inode
)->i_reserved_meta_blocks
);
1939 #define EXT4_DELALLOC_RSVED 1
1940 static int ext4_da_get_block_write(struct inode
*inode
, sector_t iblock
,
1941 struct buffer_head
*bh_result
, int create
)
1944 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1945 loff_t disksize
= EXT4_I(inode
)->i_disksize
;
1946 handle_t
*handle
= NULL
;
1948 handle
= ext4_journal_current_handle();
1950 ret
= ext4_get_blocks_wrap(handle
, inode
, iblock
, max_blocks
,
1951 bh_result
, create
, 0, EXT4_DELALLOC_RSVED
);
1955 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1957 if (ext4_should_order_data(inode
)) {
1959 retval
= ext4_jbd2_file_inode(handle
, inode
);
1962 * Failed to add inode for ordered mode. Don't
1969 * Update on-disk size along with block allocation we don't
1970 * use 'extend_disksize' as size may change within already
1971 * allocated block -bzzz
1973 disksize
= ((loff_t
) iblock
+ ret
) << inode
->i_blkbits
;
1974 if (disksize
> i_size_read(inode
))
1975 disksize
= i_size_read(inode
);
1976 if (disksize
> EXT4_I(inode
)->i_disksize
) {
1977 ext4_update_i_disksize(inode
, disksize
);
1978 ret
= ext4_mark_inode_dirty(handle
, inode
);
1985 * mpage_da_map_blocks - go through given space
1987 * @mpd - bh describing space
1989 * The function skips space we know is already mapped to disk blocks.
1992 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
1995 struct buffer_head
new;
1999 * We consider only non-mapped and non-allocated blocks
2001 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2002 !(mpd
->b_state
& (1 << BH_Delay
)))
2004 new.b_state
= mpd
->b_state
;
2006 new.b_size
= mpd
->b_size
;
2007 next
= mpd
->b_blocknr
;
2009 * If we didn't accumulate anything
2010 * to write simply return
2015 err
= ext4_da_get_block_write(mpd
->inode
, next
, &new, 1);
2018 * If get block returns with error we simply
2019 * return. Later writepage will redirty the page and
2020 * writepages will find the dirty page again
2025 if (err
== -ENOSPC
&&
2026 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
2032 * get block failure will cause us to loop in
2033 * writepages, because a_ops->writepage won't be able
2034 * to make progress. The page will be redirtied by
2035 * writepage and writepages will again try to write
2038 printk(KERN_EMERG
"%s block allocation failed for inode %lu "
2039 "at logical offset %llu with max blocks "
2040 "%zd with error %d\n",
2041 __func__
, mpd
->inode
->i_ino
,
2042 (unsigned long long)next
,
2043 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2044 printk(KERN_EMERG
"This should not happen.!! "
2045 "Data will be lost\n");
2046 if (err
== -ENOSPC
) {
2047 ext4_print_free_blocks(mpd
->inode
);
2049 /* invlaidate all the pages */
2050 ext4_da_block_invalidatepages(mpd
, next
,
2051 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2054 BUG_ON(new.b_size
== 0);
2056 if (buffer_new(&new))
2057 __unmap_underlying_blocks(mpd
->inode
, &new);
2060 * If blocks are delayed marked, we need to
2061 * put actual blocknr and drop delayed bit
2063 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2064 (mpd
->b_state
& (1 << BH_Unwritten
)))
2065 mpage_put_bnr_to_bhs(mpd
, next
, &new);
2070 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2071 (1 << BH_Delay) | (1 << BH_Unwritten))
2074 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2076 * @mpd->lbh - extent of blocks
2077 * @logical - logical number of the block in the file
2078 * @bh - bh of the block (used to access block's state)
2080 * the function is used to collect contig. blocks in same state
2082 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2083 sector_t logical
, size_t b_size
,
2084 unsigned long b_state
)
2087 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2089 /* check if thereserved journal credits might overflow */
2090 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
2091 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2093 * With non-extent format we are limited by the journal
2094 * credit available. Total credit needed to insert
2095 * nrblocks contiguous blocks is dependent on the
2096 * nrblocks. So limit nrblocks.
2099 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2100 EXT4_MAX_TRANS_DATA
) {
2102 * Adding the new buffer_head would make it cross the
2103 * allowed limit for which we have journal credit
2104 * reserved. So limit the new bh->b_size
2106 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2107 mpd
->inode
->i_blkbits
;
2108 /* we will do mpage_da_submit_io in the next loop */
2112 * First block in the extent
2114 if (mpd
->b_size
== 0) {
2115 mpd
->b_blocknr
= logical
;
2116 mpd
->b_size
= b_size
;
2117 mpd
->b_state
= b_state
& BH_FLAGS
;
2121 next
= mpd
->b_blocknr
+ nrblocks
;
2123 * Can we merge the block to our big extent?
2125 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2126 mpd
->b_size
+= b_size
;
2132 * We couldn't merge the block to our extent, so we
2133 * need to flush current extent and start new one
2135 if (mpage_da_map_blocks(mpd
) == 0)
2136 mpage_da_submit_io(mpd
);
2142 * __mpage_da_writepage - finds extent of pages and blocks
2144 * @page: page to consider
2145 * @wbc: not used, we just follow rules
2148 * The function finds extents of pages and scan them for all blocks.
2150 static int __mpage_da_writepage(struct page
*page
,
2151 struct writeback_control
*wbc
, void *data
)
2153 struct mpage_da_data
*mpd
= data
;
2154 struct inode
*inode
= mpd
->inode
;
2155 struct buffer_head
*bh
, *head
;
2160 * Rest of the page in the page_vec
2161 * redirty then and skip then. We will
2162 * try to to write them again after
2163 * starting a new transaction
2165 redirty_page_for_writepage(wbc
, page
);
2167 return MPAGE_DA_EXTENT_TAIL
;
2170 * Can we merge this page to current extent?
2172 if (mpd
->next_page
!= page
->index
) {
2174 * Nope, we can't. So, we map non-allocated blocks
2175 * and start IO on them using writepage()
2177 if (mpd
->next_page
!= mpd
->first_page
) {
2178 if (mpage_da_map_blocks(mpd
) == 0)
2179 mpage_da_submit_io(mpd
);
2181 * skip rest of the page in the page_vec
2184 redirty_page_for_writepage(wbc
, page
);
2186 return MPAGE_DA_EXTENT_TAIL
;
2190 * Start next extent of pages ...
2192 mpd
->first_page
= page
->index
;
2202 mpd
->next_page
= page
->index
+ 1;
2203 logical
= (sector_t
) page
->index
<<
2204 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2206 if (!page_has_buffers(page
)) {
2207 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2208 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2210 return MPAGE_DA_EXTENT_TAIL
;
2213 * Page with regular buffer heads, just add all dirty ones
2215 head
= page_buffers(page
);
2218 BUG_ON(buffer_locked(bh
));
2220 * We need to try to allocate
2221 * unmapped blocks in the same page.
2222 * Otherwise we won't make progress
2223 * with the page in ext4_da_writepage
2225 if (buffer_dirty(bh
) &&
2226 (!buffer_mapped(bh
) || buffer_delay(bh
))) {
2227 mpage_add_bh_to_extent(mpd
, logical
,
2231 return MPAGE_DA_EXTENT_TAIL
;
2232 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2234 * mapped dirty buffer. We need to update
2235 * the b_state because we look at
2236 * b_state in mpage_da_map_blocks. We don't
2237 * update b_size because if we find an
2238 * unmapped buffer_head later we need to
2239 * use the b_state flag of that buffer_head.
2241 if (mpd
->b_size
== 0)
2242 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2245 } while ((bh
= bh
->b_this_page
) != head
);
2252 * this is a special callback for ->write_begin() only
2253 * it's intention is to return mapped block or reserve space
2255 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2256 struct buffer_head
*bh_result
, int create
)
2260 BUG_ON(create
== 0);
2261 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2264 * first, we need to know whether the block is allocated already
2265 * preallocated blocks are unmapped but should treated
2266 * the same as allocated blocks.
2268 ret
= ext4_get_blocks_wrap(NULL
, inode
, iblock
, 1, bh_result
, 0, 0, 0);
2269 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2270 /* the block isn't (pre)allocated yet, let's reserve space */
2272 * XXX: __block_prepare_write() unmaps passed block,
2275 ret
= ext4_da_reserve_space(inode
, 1);
2277 /* not enough space to reserve */
2280 map_bh(bh_result
, inode
->i_sb
, 0);
2281 set_buffer_new(bh_result
);
2282 set_buffer_delay(bh_result
);
2283 } else if (ret
> 0) {
2284 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2291 static int ext4_bh_unmapped_or_delay(handle_t
*handle
, struct buffer_head
*bh
)
2294 * unmapped buffer is possible for holes.
2295 * delay buffer is possible with delayed allocation
2297 return ((!buffer_mapped(bh
) || buffer_delay(bh
)) && buffer_dirty(bh
));
2300 static int ext4_normal_get_block_write(struct inode
*inode
, sector_t iblock
,
2301 struct buffer_head
*bh_result
, int create
)
2304 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2307 * we don't want to do block allocation in writepage
2308 * so call get_block_wrap with create = 0
2310 ret
= ext4_get_blocks_wrap(NULL
, inode
, iblock
, max_blocks
,
2311 bh_result
, 0, 0, 0);
2313 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2320 * get called vi ext4_da_writepages after taking page lock (have journal handle)
2321 * get called via journal_submit_inode_data_buffers (no journal handle)
2322 * get called via shrink_page_list via pdflush (no journal handle)
2323 * or grab_page_cache when doing write_begin (have journal handle)
2325 static int ext4_da_writepage(struct page
*page
,
2326 struct writeback_control
*wbc
)
2331 struct buffer_head
*page_bufs
;
2332 struct inode
*inode
= page
->mapping
->host
;
2334 trace_mark(ext4_da_writepage
,
2335 "dev %s ino %lu page_index %lu",
2336 inode
->i_sb
->s_id
, inode
->i_ino
, page
->index
);
2337 size
= i_size_read(inode
);
2338 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2339 len
= size
& ~PAGE_CACHE_MASK
;
2341 len
= PAGE_CACHE_SIZE
;
2343 if (page_has_buffers(page
)) {
2344 page_bufs
= page_buffers(page
);
2345 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2346 ext4_bh_unmapped_or_delay
)) {
2348 * We don't want to do block allocation
2349 * So redirty the page and return
2350 * We may reach here when we do a journal commit
2351 * via journal_submit_inode_data_buffers.
2352 * If we don't have mapping block we just ignore
2353 * them. We can also reach here via shrink_page_list
2355 redirty_page_for_writepage(wbc
, page
);
2361 * The test for page_has_buffers() is subtle:
2362 * We know the page is dirty but it lost buffers. That means
2363 * that at some moment in time after write_begin()/write_end()
2364 * has been called all buffers have been clean and thus they
2365 * must have been written at least once. So they are all
2366 * mapped and we can happily proceed with mapping them
2367 * and writing the page.
2369 * Try to initialize the buffer_heads and check whether
2370 * all are mapped and non delay. We don't want to
2371 * do block allocation here.
2373 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
2374 ext4_normal_get_block_write
);
2376 page_bufs
= page_buffers(page
);
2377 /* check whether all are mapped and non delay */
2378 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2379 ext4_bh_unmapped_or_delay
)) {
2380 redirty_page_for_writepage(wbc
, page
);
2386 * We can't do block allocation here
2387 * so just redity the page and unlock
2390 redirty_page_for_writepage(wbc
, page
);
2394 /* now mark the buffer_heads as dirty and uptodate */
2395 block_commit_write(page
, 0, PAGE_CACHE_SIZE
);
2398 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2399 ret
= nobh_writepage(page
, ext4_normal_get_block_write
, wbc
);
2401 ret
= block_write_full_page(page
,
2402 ext4_normal_get_block_write
,
2409 * This is called via ext4_da_writepages() to
2410 * calulate the total number of credits to reserve to fit
2411 * a single extent allocation into a single transaction,
2412 * ext4_da_writpeages() will loop calling this before
2413 * the block allocation.
2416 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2418 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2421 * With non-extent format the journal credit needed to
2422 * insert nrblocks contiguous block is dependent on
2423 * number of contiguous block. So we will limit
2424 * number of contiguous block to a sane value
2426 if (!(inode
->i_flags
& EXT4_EXTENTS_FL
) &&
2427 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2428 max_blocks
= EXT4_MAX_TRANS_DATA
;
2430 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2433 static int ext4_da_writepages(struct address_space
*mapping
,
2434 struct writeback_control
*wbc
)
2437 int range_whole
= 0;
2438 handle_t
*handle
= NULL
;
2439 struct mpage_da_data mpd
;
2440 struct inode
*inode
= mapping
->host
;
2441 int no_nrwrite_index_update
;
2442 int pages_written
= 0;
2444 int range_cyclic
, cycled
= 1, io_done
= 0;
2445 int needed_blocks
, ret
= 0, nr_to_writebump
= 0;
2446 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2448 trace_mark(ext4_da_writepages
,
2449 "dev %s ino %lu nr_t_write %ld "
2450 "pages_skipped %ld range_start %llu "
2451 "range_end %llu nonblocking %d "
2452 "for_kupdate %d for_reclaim %d "
2453 "for_writepages %d range_cyclic %d",
2454 inode
->i_sb
->s_id
, inode
->i_ino
,
2455 wbc
->nr_to_write
, wbc
->pages_skipped
,
2456 (unsigned long long) wbc
->range_start
,
2457 (unsigned long long) wbc
->range_end
,
2458 wbc
->nonblocking
, wbc
->for_kupdate
,
2459 wbc
->for_reclaim
, wbc
->for_writepages
,
2463 * No pages to write? This is mainly a kludge to avoid starting
2464 * a transaction for special inodes like journal inode on last iput()
2465 * because that could violate lock ordering on umount
2467 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2471 * If the filesystem has aborted, it is read-only, so return
2472 * right away instead of dumping stack traces later on that
2473 * will obscure the real source of the problem. We test
2474 * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because
2475 * the latter could be true if the filesystem is mounted
2476 * read-only, and in that case, ext4_da_writepages should
2477 * *never* be called, so if that ever happens, we would want
2480 if (unlikely(sbi
->s_mount_opt
& EXT4_MOUNT_ABORT
))
2484 * Make sure nr_to_write is >= sbi->s_mb_stream_request
2485 * This make sure small files blocks are allocated in
2486 * single attempt. This ensure that small files
2487 * get less fragmented.
2489 if (wbc
->nr_to_write
< sbi
->s_mb_stream_request
) {
2490 nr_to_writebump
= sbi
->s_mb_stream_request
- wbc
->nr_to_write
;
2491 wbc
->nr_to_write
= sbi
->s_mb_stream_request
;
2493 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2496 range_cyclic
= wbc
->range_cyclic
;
2497 if (wbc
->range_cyclic
) {
2498 index
= mapping
->writeback_index
;
2501 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2502 wbc
->range_end
= LLONG_MAX
;
2503 wbc
->range_cyclic
= 0;
2505 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2508 mpd
.inode
= mapping
->host
;
2511 * we don't want write_cache_pages to update
2512 * nr_to_write and writeback_index
2514 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2515 wbc
->no_nrwrite_index_update
= 1;
2516 pages_skipped
= wbc
->pages_skipped
;
2519 while (!ret
&& wbc
->nr_to_write
> 0) {
2522 * we insert one extent at a time. So we need
2523 * credit needed for single extent allocation.
2524 * journalled mode is currently not supported
2527 BUG_ON(ext4_should_journal_data(inode
));
2528 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2530 /* start a new transaction*/
2531 handle
= ext4_journal_start(inode
, needed_blocks
);
2532 if (IS_ERR(handle
)) {
2533 ret
= PTR_ERR(handle
);
2534 printk(KERN_CRIT
"%s: jbd2_start: "
2535 "%ld pages, ino %lu; err %d\n", __func__
,
2536 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2538 goto out_writepages
;
2542 * Now call __mpage_da_writepage to find the next
2543 * contiguous region of logical blocks that need
2544 * blocks to be allocated by ext4. We don't actually
2545 * submit the blocks for I/O here, even though
2546 * write_cache_pages thinks it will, and will set the
2547 * pages as clean for write before calling
2548 * __mpage_da_writepage().
2556 mpd
.pages_written
= 0;
2558 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
,
2561 * If we have a contigous extent of pages and we
2562 * haven't done the I/O yet, map the blocks and submit
2565 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
2566 if (mpage_da_map_blocks(&mpd
) == 0)
2567 mpage_da_submit_io(&mpd
);
2569 ret
= MPAGE_DA_EXTENT_TAIL
;
2571 wbc
->nr_to_write
-= mpd
.pages_written
;
2573 ext4_journal_stop(handle
);
2575 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2576 /* commit the transaction which would
2577 * free blocks released in the transaction
2580 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2581 wbc
->pages_skipped
= pages_skipped
;
2583 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2585 * got one extent now try with
2588 pages_written
+= mpd
.pages_written
;
2589 wbc
->pages_skipped
= pages_skipped
;
2592 } else if (wbc
->nr_to_write
)
2594 * There is no more writeout needed
2595 * or we requested for a noblocking writeout
2596 * and we found the device congested
2600 if (!io_done
&& !cycled
) {
2603 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2604 wbc
->range_end
= mapping
->writeback_index
- 1;
2607 if (pages_skipped
!= wbc
->pages_skipped
)
2608 printk(KERN_EMERG
"This should not happen leaving %s "
2609 "with nr_to_write = %ld ret = %d\n",
2610 __func__
, wbc
->nr_to_write
, ret
);
2613 index
+= pages_written
;
2614 wbc
->range_cyclic
= range_cyclic
;
2615 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2617 * set the writeback_index so that range_cyclic
2618 * mode will write it back later
2620 mapping
->writeback_index
= index
;
2623 if (!no_nrwrite_index_update
)
2624 wbc
->no_nrwrite_index_update
= 0;
2625 wbc
->nr_to_write
-= nr_to_writebump
;
2626 trace_mark(ext4_da_writepage_result
,
2627 "dev %s ino %lu ret %d pages_written %d "
2628 "pages_skipped %ld congestion %d "
2629 "more_io %d no_nrwrite_index_update %d",
2630 inode
->i_sb
->s_id
, inode
->i_ino
, ret
,
2631 pages_written
, wbc
->pages_skipped
,
2632 wbc
->encountered_congestion
, wbc
->more_io
,
2633 wbc
->no_nrwrite_index_update
);
2637 #define FALL_BACK_TO_NONDELALLOC 1
2638 static int ext4_nonda_switch(struct super_block
*sb
)
2640 s64 free_blocks
, dirty_blocks
;
2641 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2644 * switch to non delalloc mode if we are running low
2645 * on free block. The free block accounting via percpu
2646 * counters can get slightly wrong with percpu_counter_batch getting
2647 * accumulated on each CPU without updating global counters
2648 * Delalloc need an accurate free block accounting. So switch
2649 * to non delalloc when we are near to error range.
2651 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
2652 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
2653 if (2 * free_blocks
< 3 * dirty_blocks
||
2654 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
2656 * free block count is less that 150% of dirty blocks
2657 * or free blocks is less that watermark
2664 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
2665 loff_t pos
, unsigned len
, unsigned flags
,
2666 struct page
**pagep
, void **fsdata
)
2668 int ret
, retries
= 0;
2672 struct inode
*inode
= mapping
->host
;
2675 index
= pos
>> PAGE_CACHE_SHIFT
;
2676 from
= pos
& (PAGE_CACHE_SIZE
- 1);
2679 if (ext4_nonda_switch(inode
->i_sb
)) {
2680 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
2681 return ext4_write_begin(file
, mapping
, pos
,
2682 len
, flags
, pagep
, fsdata
);
2684 *fsdata
= (void *)0;
2686 trace_mark(ext4_da_write_begin
,
2687 "dev %s ino %lu pos %llu len %u flags %u",
2688 inode
->i_sb
->s_id
, inode
->i_ino
,
2689 (unsigned long long) pos
, len
, flags
);
2692 * With delayed allocation, we don't log the i_disksize update
2693 * if there is delayed block allocation. But we still need
2694 * to journalling the i_disksize update if writes to the end
2695 * of file which has an already mapped buffer.
2697 handle
= ext4_journal_start(inode
, 1);
2698 if (IS_ERR(handle
)) {
2699 ret
= PTR_ERR(handle
);
2702 /* We cannot recurse into the filesystem as the transaction is already
2704 flags
|= AOP_FLAG_NOFS
;
2706 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
2708 ext4_journal_stop(handle
);
2714 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
2715 ext4_da_get_block_prep
);
2718 ext4_journal_stop(handle
);
2719 page_cache_release(page
);
2721 * block_write_begin may have instantiated a few blocks
2722 * outside i_size. Trim these off again. Don't need
2723 * i_size_read because we hold i_mutex.
2725 if (pos
+ len
> inode
->i_size
)
2726 vmtruncate(inode
, inode
->i_size
);
2729 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
2736 * Check if we should update i_disksize
2737 * when write to the end of file but not require block allocation
2739 static int ext4_da_should_update_i_disksize(struct page
*page
,
2740 unsigned long offset
)
2742 struct buffer_head
*bh
;
2743 struct inode
*inode
= page
->mapping
->host
;
2747 bh
= page_buffers(page
);
2748 idx
= offset
>> inode
->i_blkbits
;
2750 for (i
= 0; i
< idx
; i
++)
2751 bh
= bh
->b_this_page
;
2753 if (!buffer_mapped(bh
) || (buffer_delay(bh
)))
2758 static int ext4_da_write_end(struct file
*file
,
2759 struct address_space
*mapping
,
2760 loff_t pos
, unsigned len
, unsigned copied
,
2761 struct page
*page
, void *fsdata
)
2763 struct inode
*inode
= mapping
->host
;
2765 handle_t
*handle
= ext4_journal_current_handle();
2767 unsigned long start
, end
;
2768 int write_mode
= (int)(unsigned long)fsdata
;
2770 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
2771 if (ext4_should_order_data(inode
)) {
2772 return ext4_ordered_write_end(file
, mapping
, pos
,
2773 len
, copied
, page
, fsdata
);
2774 } else if (ext4_should_writeback_data(inode
)) {
2775 return ext4_writeback_write_end(file
, mapping
, pos
,
2776 len
, copied
, page
, fsdata
);
2782 trace_mark(ext4_da_write_end
,
2783 "dev %s ino %lu pos %llu len %u copied %u",
2784 inode
->i_sb
->s_id
, inode
->i_ino
,
2785 (unsigned long long) pos
, len
, copied
);
2786 start
= pos
& (PAGE_CACHE_SIZE
- 1);
2787 end
= start
+ copied
- 1;
2790 * generic_write_end() will run mark_inode_dirty() if i_size
2791 * changes. So let's piggyback the i_disksize mark_inode_dirty
2795 new_i_size
= pos
+ copied
;
2796 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2797 if (ext4_da_should_update_i_disksize(page
, end
)) {
2798 down_write(&EXT4_I(inode
)->i_data_sem
);
2799 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2801 * Updating i_disksize when extending file
2802 * without needing block allocation
2804 if (ext4_should_order_data(inode
))
2805 ret
= ext4_jbd2_file_inode(handle
,
2808 EXT4_I(inode
)->i_disksize
= new_i_size
;
2810 up_write(&EXT4_I(inode
)->i_data_sem
);
2811 /* We need to mark inode dirty even if
2812 * new_i_size is less that inode->i_size
2813 * bu greater than i_disksize.(hint delalloc)
2815 ext4_mark_inode_dirty(handle
, inode
);
2818 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
2823 ret2
= ext4_journal_stop(handle
);
2827 return ret
? ret
: copied
;
2830 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
2833 * Drop reserved blocks
2835 BUG_ON(!PageLocked(page
));
2836 if (!page_has_buffers(page
))
2839 ext4_da_page_release_reservation(page
, offset
);
2842 ext4_invalidatepage(page
, offset
);
2848 * Force all delayed allocation blocks to be allocated for a given inode.
2850 int ext4_alloc_da_blocks(struct inode
*inode
)
2852 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
2853 !EXT4_I(inode
)->i_reserved_meta_blocks
)
2857 * We do something simple for now. The filemap_flush() will
2858 * also start triggering a write of the data blocks, which is
2859 * not strictly speaking necessary (and for users of
2860 * laptop_mode, not even desirable). However, to do otherwise
2861 * would require replicating code paths in:
2863 * ext4_da_writepages() ->
2864 * write_cache_pages() ---> (via passed in callback function)
2865 * __mpage_da_writepage() -->
2866 * mpage_add_bh_to_extent()
2867 * mpage_da_map_blocks()
2869 * The problem is that write_cache_pages(), located in
2870 * mm/page-writeback.c, marks pages clean in preparation for
2871 * doing I/O, which is not desirable if we're not planning on
2874 * We could call write_cache_pages(), and then redirty all of
2875 * the pages by calling redirty_page_for_writeback() but that
2876 * would be ugly in the extreme. So instead we would need to
2877 * replicate parts of the code in the above functions,
2878 * simplifying them becuase we wouldn't actually intend to
2879 * write out the pages, but rather only collect contiguous
2880 * logical block extents, call the multi-block allocator, and
2881 * then update the buffer heads with the block allocations.
2883 * For now, though, we'll cheat by calling filemap_flush(),
2884 * which will map the blocks, and start the I/O, but not
2885 * actually wait for the I/O to complete.
2887 return filemap_flush(inode
->i_mapping
);
2891 * bmap() is special. It gets used by applications such as lilo and by
2892 * the swapper to find the on-disk block of a specific piece of data.
2894 * Naturally, this is dangerous if the block concerned is still in the
2895 * journal. If somebody makes a swapfile on an ext4 data-journaling
2896 * filesystem and enables swap, then they may get a nasty shock when the
2897 * data getting swapped to that swapfile suddenly gets overwritten by
2898 * the original zero's written out previously to the journal and
2899 * awaiting writeback in the kernel's buffer cache.
2901 * So, if we see any bmap calls here on a modified, data-journaled file,
2902 * take extra steps to flush any blocks which might be in the cache.
2904 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
2906 struct inode
*inode
= mapping
->host
;
2910 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
2911 test_opt(inode
->i_sb
, DELALLOC
)) {
2913 * With delalloc we want to sync the file
2914 * so that we can make sure we allocate
2917 filemap_write_and_wait(mapping
);
2920 if (EXT4_JOURNAL(inode
) && EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
2922 * This is a REALLY heavyweight approach, but the use of
2923 * bmap on dirty files is expected to be extremely rare:
2924 * only if we run lilo or swapon on a freshly made file
2925 * do we expect this to happen.
2927 * (bmap requires CAP_SYS_RAWIO so this does not
2928 * represent an unprivileged user DOS attack --- we'd be
2929 * in trouble if mortal users could trigger this path at
2932 * NB. EXT4_STATE_JDATA is not set on files other than
2933 * regular files. If somebody wants to bmap a directory
2934 * or symlink and gets confused because the buffer
2935 * hasn't yet been flushed to disk, they deserve
2936 * everything they get.
2939 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
2940 journal
= EXT4_JOURNAL(inode
);
2941 jbd2_journal_lock_updates(journal
);
2942 err
= jbd2_journal_flush(journal
);
2943 jbd2_journal_unlock_updates(journal
);
2949 return generic_block_bmap(mapping
, block
, ext4_get_block
);
2952 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2958 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2965 * Note that we don't need to start a transaction unless we're journaling data
2966 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2967 * need to file the inode to the transaction's list in ordered mode because if
2968 * we are writing back data added by write(), the inode is already there and if
2969 * we are writing back data modified via mmap(), noone guarantees in which
2970 * transaction the data will hit the disk. In case we are journaling data, we
2971 * cannot start transaction directly because transaction start ranks above page
2972 * lock so we have to do some magic.
2974 * In all journaling modes block_write_full_page() will start the I/O.
2978 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2983 * ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ...
2985 * Same applies to ext4_get_block(). We will deadlock on various things like
2986 * lock_journal and i_data_sem
2988 * Setting PF_MEMALLOC here doesn't work - too many internal memory
2991 * 16May01: If we're reentered then journal_current_handle() will be
2992 * non-zero. We simply *return*.
2994 * 1 July 2001: @@@ FIXME:
2995 * In journalled data mode, a data buffer may be metadata against the
2996 * current transaction. But the same file is part of a shared mapping
2997 * and someone does a writepage() on it.
2999 * We will move the buffer onto the async_data list, but *after* it has
3000 * been dirtied. So there's a small window where we have dirty data on
3003 * Note that this only applies to the last partial page in the file. The
3004 * bit which block_write_full_page() uses prepare/commit for. (That's
3005 * broken code anyway: it's wrong for msync()).
3007 * It's a rare case: affects the final partial page, for journalled data
3008 * where the file is subject to bith write() and writepage() in the same
3009 * transction. To fix it we'll need a custom block_write_full_page().
3010 * We'll probably need that anyway for journalling writepage() output.
3012 * We don't honour synchronous mounts for writepage(). That would be
3013 * disastrous. Any write() or metadata operation will sync the fs for
3017 static int __ext4_normal_writepage(struct page
*page
,
3018 struct writeback_control
*wbc
)
3020 struct inode
*inode
= page
->mapping
->host
;
3022 if (test_opt(inode
->i_sb
, NOBH
))
3023 return nobh_writepage(page
,
3024 ext4_normal_get_block_write
, wbc
);
3026 return block_write_full_page(page
,
3027 ext4_normal_get_block_write
,
3031 static int ext4_normal_writepage(struct page
*page
,
3032 struct writeback_control
*wbc
)
3034 struct inode
*inode
= page
->mapping
->host
;
3035 loff_t size
= i_size_read(inode
);
3038 trace_mark(ext4_normal_writepage
,
3039 "dev %s ino %lu page_index %lu",
3040 inode
->i_sb
->s_id
, inode
->i_ino
, page
->index
);
3041 J_ASSERT(PageLocked(page
));
3042 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
3043 len
= size
& ~PAGE_CACHE_MASK
;
3045 len
= PAGE_CACHE_SIZE
;
3047 if (page_has_buffers(page
)) {
3048 /* if page has buffers it should all be mapped
3049 * and allocated. If there are not buffers attached
3050 * to the page we know the page is dirty but it lost
3051 * buffers. That means that at some moment in time
3052 * after write_begin() / write_end() has been called
3053 * all buffers have been clean and thus they must have been
3054 * written at least once. So they are all mapped and we can
3055 * happily proceed with mapping them and writing the page.
3057 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
3058 ext4_bh_unmapped_or_delay
));
3061 if (!ext4_journal_current_handle())
3062 return __ext4_normal_writepage(page
, wbc
);
3064 redirty_page_for_writepage(wbc
, page
);
3069 static int __ext4_journalled_writepage(struct page
*page
,
3070 struct writeback_control
*wbc
)
3072 struct address_space
*mapping
= page
->mapping
;
3073 struct inode
*inode
= mapping
->host
;
3074 struct buffer_head
*page_bufs
;
3075 handle_t
*handle
= NULL
;
3079 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
3080 ext4_normal_get_block_write
);
3084 page_bufs
= page_buffers(page
);
3085 walk_page_buffers(handle
, page_bufs
, 0, PAGE_CACHE_SIZE
, NULL
,
3087 /* As soon as we unlock the page, it can go away, but we have
3088 * references to buffers so we are safe */
3091 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
3092 if (IS_ERR(handle
)) {
3093 ret
= PTR_ERR(handle
);
3097 ret
= walk_page_buffers(handle
, page_bufs
, 0,
3098 PAGE_CACHE_SIZE
, NULL
, do_journal_get_write_access
);
3100 err
= walk_page_buffers(handle
, page_bufs
, 0,
3101 PAGE_CACHE_SIZE
, NULL
, write_end_fn
);
3104 err
= ext4_journal_stop(handle
);
3108 walk_page_buffers(handle
, page_bufs
, 0,
3109 PAGE_CACHE_SIZE
, NULL
, bput_one
);
3110 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
3119 static int ext4_journalled_writepage(struct page
*page
,
3120 struct writeback_control
*wbc
)
3122 struct inode
*inode
= page
->mapping
->host
;
3123 loff_t size
= i_size_read(inode
);
3126 trace_mark(ext4_journalled_writepage
,
3127 "dev %s ino %lu page_index %lu",
3128 inode
->i_sb
->s_id
, inode
->i_ino
, page
->index
);
3129 J_ASSERT(PageLocked(page
));
3130 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
3131 len
= size
& ~PAGE_CACHE_MASK
;
3133 len
= PAGE_CACHE_SIZE
;
3135 if (page_has_buffers(page
)) {
3136 /* if page has buffers it should all be mapped
3137 * and allocated. If there are not buffers attached
3138 * to the page we know the page is dirty but it lost
3139 * buffers. That means that at some moment in time
3140 * after write_begin() / write_end() has been called
3141 * all buffers have been clean and thus they must have been
3142 * written at least once. So they are all mapped and we can
3143 * happily proceed with mapping them and writing the page.
3145 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
3146 ext4_bh_unmapped_or_delay
));
3149 if (ext4_journal_current_handle())
3152 if (PageChecked(page
)) {
3154 * It's mmapped pagecache. Add buffers and journal it. There
3155 * doesn't seem much point in redirtying the page here.
3157 ClearPageChecked(page
);
3158 return __ext4_journalled_writepage(page
, wbc
);
3161 * It may be a page full of checkpoint-mode buffers. We don't
3162 * really know unless we go poke around in the buffer_heads.
3163 * But block_write_full_page will do the right thing.
3165 return block_write_full_page(page
,
3166 ext4_normal_get_block_write
,
3170 redirty_page_for_writepage(wbc
, page
);
3175 static int ext4_readpage(struct file
*file
, struct page
*page
)
3177 return mpage_readpage(page
, ext4_get_block
);
3181 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3182 struct list_head
*pages
, unsigned nr_pages
)
3184 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3187 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3189 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3192 * If it's a full truncate we just forget about the pending dirtying
3195 ClearPageChecked(page
);
3198 jbd2_journal_invalidatepage(journal
, page
, offset
);
3200 block_invalidatepage(page
, offset
);
3203 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3205 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3207 WARN_ON(PageChecked(page
));
3208 if (!page_has_buffers(page
))
3211 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3213 return try_to_free_buffers(page
);
3217 * If the O_DIRECT write will extend the file then add this inode to the
3218 * orphan list. So recovery will truncate it back to the original size
3219 * if the machine crashes during the write.
3221 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3222 * crashes then stale disk data _may_ be exposed inside the file. But current
3223 * VFS code falls back into buffered path in that case so we are safe.
3225 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3226 const struct iovec
*iov
, loff_t offset
,
3227 unsigned long nr_segs
)
3229 struct file
*file
= iocb
->ki_filp
;
3230 struct inode
*inode
= file
->f_mapping
->host
;
3231 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3235 size_t count
= iov_length(iov
, nr_segs
);
3238 loff_t final_size
= offset
+ count
;
3240 if (final_size
> inode
->i_size
) {
3241 /* Credits for sb + inode write */
3242 handle
= ext4_journal_start(inode
, 2);
3243 if (IS_ERR(handle
)) {
3244 ret
= PTR_ERR(handle
);
3247 ret
= ext4_orphan_add(handle
, inode
);
3249 ext4_journal_stop(handle
);
3253 ei
->i_disksize
= inode
->i_size
;
3254 ext4_journal_stop(handle
);
3258 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3260 ext4_get_block
, NULL
);
3265 /* Credits for sb + inode write */
3266 handle
= ext4_journal_start(inode
, 2);
3267 if (IS_ERR(handle
)) {
3268 /* This is really bad luck. We've written the data
3269 * but cannot extend i_size. Bail out and pretend
3270 * the write failed... */
3271 ret
= PTR_ERR(handle
);
3275 ext4_orphan_del(handle
, inode
);
3277 loff_t end
= offset
+ ret
;
3278 if (end
> inode
->i_size
) {
3279 ei
->i_disksize
= end
;
3280 i_size_write(inode
, end
);
3282 * We're going to return a positive `ret'
3283 * here due to non-zero-length I/O, so there's
3284 * no way of reporting error returns from
3285 * ext4_mark_inode_dirty() to userspace. So
3288 ext4_mark_inode_dirty(handle
, inode
);
3291 err
= ext4_journal_stop(handle
);
3300 * Pages can be marked dirty completely asynchronously from ext4's journalling
3301 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3302 * much here because ->set_page_dirty is called under VFS locks. The page is
3303 * not necessarily locked.
3305 * We cannot just dirty the page and leave attached buffers clean, because the
3306 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3307 * or jbddirty because all the journalling code will explode.
3309 * So what we do is to mark the page "pending dirty" and next time writepage
3310 * is called, propagate that into the buffers appropriately.
3312 static int ext4_journalled_set_page_dirty(struct page
*page
)
3314 SetPageChecked(page
);
3315 return __set_page_dirty_nobuffers(page
);
3318 static const struct address_space_operations ext4_ordered_aops
= {
3319 .readpage
= ext4_readpage
,
3320 .readpages
= ext4_readpages
,
3321 .writepage
= ext4_normal_writepage
,
3322 .sync_page
= block_sync_page
,
3323 .write_begin
= ext4_write_begin
,
3324 .write_end
= ext4_ordered_write_end
,
3326 .invalidatepage
= ext4_invalidatepage
,
3327 .releasepage
= ext4_releasepage
,
3328 .direct_IO
= ext4_direct_IO
,
3329 .migratepage
= buffer_migrate_page
,
3330 .is_partially_uptodate
= block_is_partially_uptodate
,
3333 static const struct address_space_operations ext4_writeback_aops
= {
3334 .readpage
= ext4_readpage
,
3335 .readpages
= ext4_readpages
,
3336 .writepage
= ext4_normal_writepage
,
3337 .sync_page
= block_sync_page
,
3338 .write_begin
= ext4_write_begin
,
3339 .write_end
= ext4_writeback_write_end
,
3341 .invalidatepage
= ext4_invalidatepage
,
3342 .releasepage
= ext4_releasepage
,
3343 .direct_IO
= ext4_direct_IO
,
3344 .migratepage
= buffer_migrate_page
,
3345 .is_partially_uptodate
= block_is_partially_uptodate
,
3348 static const struct address_space_operations ext4_journalled_aops
= {
3349 .readpage
= ext4_readpage
,
3350 .readpages
= ext4_readpages
,
3351 .writepage
= ext4_journalled_writepage
,
3352 .sync_page
= block_sync_page
,
3353 .write_begin
= ext4_write_begin
,
3354 .write_end
= ext4_journalled_write_end
,
3355 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3357 .invalidatepage
= ext4_invalidatepage
,
3358 .releasepage
= ext4_releasepage
,
3359 .is_partially_uptodate
= block_is_partially_uptodate
,
3362 static const struct address_space_operations ext4_da_aops
= {
3363 .readpage
= ext4_readpage
,
3364 .readpages
= ext4_readpages
,
3365 .writepage
= ext4_da_writepage
,
3366 .writepages
= ext4_da_writepages
,
3367 .sync_page
= block_sync_page
,
3368 .write_begin
= ext4_da_write_begin
,
3369 .write_end
= ext4_da_write_end
,
3371 .invalidatepage
= ext4_da_invalidatepage
,
3372 .releasepage
= ext4_releasepage
,
3373 .direct_IO
= ext4_direct_IO
,
3374 .migratepage
= buffer_migrate_page
,
3375 .is_partially_uptodate
= block_is_partially_uptodate
,
3378 void ext4_set_aops(struct inode
*inode
)
3380 if (ext4_should_order_data(inode
) &&
3381 test_opt(inode
->i_sb
, DELALLOC
))
3382 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3383 else if (ext4_should_order_data(inode
))
3384 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3385 else if (ext4_should_writeback_data(inode
) &&
3386 test_opt(inode
->i_sb
, DELALLOC
))
3387 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3388 else if (ext4_should_writeback_data(inode
))
3389 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3391 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3395 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3396 * up to the end of the block which corresponds to `from'.
3397 * This required during truncate. We need to physically zero the tail end
3398 * of that block so it doesn't yield old data if the file is later grown.
3400 int ext4_block_truncate_page(handle_t
*handle
,
3401 struct address_space
*mapping
, loff_t from
)
3403 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3404 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3405 unsigned blocksize
, length
, pos
;
3407 struct inode
*inode
= mapping
->host
;
3408 struct buffer_head
*bh
;
3412 page
= grab_cache_page(mapping
, from
>> PAGE_CACHE_SHIFT
);
3416 blocksize
= inode
->i_sb
->s_blocksize
;
3417 length
= blocksize
- (offset
& (blocksize
- 1));
3418 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3421 * For "nobh" option, we can only work if we don't need to
3422 * read-in the page - otherwise we create buffers to do the IO.
3424 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3425 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3426 zero_user(page
, offset
, length
);
3427 set_page_dirty(page
);
3431 if (!page_has_buffers(page
))
3432 create_empty_buffers(page
, blocksize
, 0);
3434 /* Find the buffer that contains "offset" */
3435 bh
= page_buffers(page
);
3437 while (offset
>= pos
) {
3438 bh
= bh
->b_this_page
;
3444 if (buffer_freed(bh
)) {
3445 BUFFER_TRACE(bh
, "freed: skip");
3449 if (!buffer_mapped(bh
)) {
3450 BUFFER_TRACE(bh
, "unmapped");
3451 ext4_get_block(inode
, iblock
, bh
, 0);
3452 /* unmapped? It's a hole - nothing to do */
3453 if (!buffer_mapped(bh
)) {
3454 BUFFER_TRACE(bh
, "still unmapped");
3459 /* Ok, it's mapped. Make sure it's up-to-date */
3460 if (PageUptodate(page
))
3461 set_buffer_uptodate(bh
);
3463 if (!buffer_uptodate(bh
)) {
3465 ll_rw_block(READ
, 1, &bh
);
3467 /* Uhhuh. Read error. Complain and punt. */
3468 if (!buffer_uptodate(bh
))
3472 if (ext4_should_journal_data(inode
)) {
3473 BUFFER_TRACE(bh
, "get write access");
3474 err
= ext4_journal_get_write_access(handle
, bh
);
3479 zero_user(page
, offset
, length
);
3481 BUFFER_TRACE(bh
, "zeroed end of block");
3484 if (ext4_should_journal_data(inode
)) {
3485 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
3487 if (ext4_should_order_data(inode
))
3488 err
= ext4_jbd2_file_inode(handle
, inode
);
3489 mark_buffer_dirty(bh
);
3494 page_cache_release(page
);
3499 * Probably it should be a library function... search for first non-zero word
3500 * or memcmp with zero_page, whatever is better for particular architecture.
3503 static inline int all_zeroes(__le32
*p
, __le32
*q
)
3512 * ext4_find_shared - find the indirect blocks for partial truncation.
3513 * @inode: inode in question
3514 * @depth: depth of the affected branch
3515 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
3516 * @chain: place to store the pointers to partial indirect blocks
3517 * @top: place to the (detached) top of branch
3519 * This is a helper function used by ext4_truncate().
3521 * When we do truncate() we may have to clean the ends of several
3522 * indirect blocks but leave the blocks themselves alive. Block is
3523 * partially truncated if some data below the new i_size is refered
3524 * from it (and it is on the path to the first completely truncated
3525 * data block, indeed). We have to free the top of that path along
3526 * with everything to the right of the path. Since no allocation
3527 * past the truncation point is possible until ext4_truncate()
3528 * finishes, we may safely do the latter, but top of branch may
3529 * require special attention - pageout below the truncation point
3530 * might try to populate it.
3532 * We atomically detach the top of branch from the tree, store the
3533 * block number of its root in *@top, pointers to buffer_heads of
3534 * partially truncated blocks - in @chain[].bh and pointers to
3535 * their last elements that should not be removed - in
3536 * @chain[].p. Return value is the pointer to last filled element
3539 * The work left to caller to do the actual freeing of subtrees:
3540 * a) free the subtree starting from *@top
3541 * b) free the subtrees whose roots are stored in
3542 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
3543 * c) free the subtrees growing from the inode past the @chain[0].
3544 * (no partially truncated stuff there). */
3546 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
3547 ext4_lblk_t offsets
[4], Indirect chain
[4], __le32
*top
)
3549 Indirect
*partial
, *p
;
3553 /* Make k index the deepest non-null offest + 1 */
3554 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
3556 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
3557 /* Writer: pointers */
3559 partial
= chain
+ k
-1;
3561 * If the branch acquired continuation since we've looked at it -
3562 * fine, it should all survive and (new) top doesn't belong to us.
3564 if (!partial
->key
&& *partial
->p
)
3567 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
3570 * OK, we've found the last block that must survive. The rest of our
3571 * branch should be detached before unlocking. However, if that rest
3572 * of branch is all ours and does not grow immediately from the inode
3573 * it's easier to cheat and just decrement partial->p.
3575 if (p
== chain
+ k
- 1 && p
> chain
) {
3579 /* Nope, don't do this in ext4. Must leave the tree intact */
3586 while (partial
> p
) {
3587 brelse(partial
->bh
);
3595 * Zero a number of block pointers in either an inode or an indirect block.
3596 * If we restart the transaction we must again get write access to the
3597 * indirect block for further modification.
3599 * We release `count' blocks on disk, but (last - first) may be greater
3600 * than `count' because there can be holes in there.
3602 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
3603 struct buffer_head
*bh
, ext4_fsblk_t block_to_free
,
3604 unsigned long count
, __le32
*first
, __le32
*last
)
3607 if (try_to_extend_transaction(handle
, inode
)) {
3609 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
3610 ext4_handle_dirty_metadata(handle
, inode
, bh
);
3612 ext4_mark_inode_dirty(handle
, inode
);
3613 ext4_journal_test_restart(handle
, inode
);
3615 BUFFER_TRACE(bh
, "retaking write access");
3616 ext4_journal_get_write_access(handle
, bh
);
3621 * Any buffers which are on the journal will be in memory. We find
3622 * them on the hash table so jbd2_journal_revoke() will run jbd2_journal_forget()
3623 * on them. We've already detached each block from the file, so
3624 * bforget() in jbd2_journal_forget() should be safe.
3626 * AKPM: turn on bforget in jbd2_journal_forget()!!!
3628 for (p
= first
; p
< last
; p
++) {
3629 u32 nr
= le32_to_cpu(*p
);
3631 struct buffer_head
*tbh
;
3634 tbh
= sb_find_get_block(inode
->i_sb
, nr
);
3635 ext4_forget(handle
, 0, inode
, tbh
, nr
);
3639 ext4_free_blocks(handle
, inode
, block_to_free
, count
, 0);
3643 * ext4_free_data - free a list of data blocks
3644 * @handle: handle for this transaction
3645 * @inode: inode we are dealing with
3646 * @this_bh: indirect buffer_head which contains *@first and *@last
3647 * @first: array of block numbers
3648 * @last: points immediately past the end of array
3650 * We are freeing all blocks refered from that array (numbers are stored as
3651 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
3653 * We accumulate contiguous runs of blocks to free. Conveniently, if these
3654 * blocks are contiguous then releasing them at one time will only affect one
3655 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
3656 * actually use a lot of journal space.
3658 * @this_bh will be %NULL if @first and @last point into the inode's direct
3661 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
3662 struct buffer_head
*this_bh
,
3663 __le32
*first
, __le32
*last
)
3665 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
3666 unsigned long count
= 0; /* Number of blocks in the run */
3667 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
3670 ext4_fsblk_t nr
; /* Current block # */
3671 __le32
*p
; /* Pointer into inode/ind
3672 for current block */
3675 if (this_bh
) { /* For indirect block */
3676 BUFFER_TRACE(this_bh
, "get_write_access");
3677 err
= ext4_journal_get_write_access(handle
, this_bh
);
3678 /* Important: if we can't update the indirect pointers
3679 * to the blocks, we can't free them. */
3684 for (p
= first
; p
< last
; p
++) {
3685 nr
= le32_to_cpu(*p
);
3687 /* accumulate blocks to free if they're contiguous */
3690 block_to_free_p
= p
;
3692 } else if (nr
== block_to_free
+ count
) {
3695 ext4_clear_blocks(handle
, inode
, this_bh
,
3697 count
, block_to_free_p
, p
);
3699 block_to_free_p
= p
;
3706 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
3707 count
, block_to_free_p
, p
);
3710 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
3713 * The buffer head should have an attached journal head at this
3714 * point. However, if the data is corrupted and an indirect
3715 * block pointed to itself, it would have been detached when
3716 * the block was cleared. Check for this instead of OOPSing.
3718 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
3719 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
3721 ext4_error(inode
->i_sb
, __func__
,
3722 "circular indirect block detected, "
3723 "inode=%lu, block=%llu",
3725 (unsigned long long) this_bh
->b_blocknr
);
3730 * ext4_free_branches - free an array of branches
3731 * @handle: JBD handle for this transaction
3732 * @inode: inode we are dealing with
3733 * @parent_bh: the buffer_head which contains *@first and *@last
3734 * @first: array of block numbers
3735 * @last: pointer immediately past the end of array
3736 * @depth: depth of the branches to free
3738 * We are freeing all blocks refered from these branches (numbers are
3739 * stored as little-endian 32-bit) and updating @inode->i_blocks
3742 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
3743 struct buffer_head
*parent_bh
,
3744 __le32
*first
, __le32
*last
, int depth
)
3749 if (ext4_handle_is_aborted(handle
))
3753 struct buffer_head
*bh
;
3754 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
3756 while (--p
>= first
) {
3757 nr
= le32_to_cpu(*p
);
3759 continue; /* A hole */
3761 /* Go read the buffer for the next level down */
3762 bh
= sb_bread(inode
->i_sb
, nr
);
3765 * A read failure? Report error and clear slot
3769 ext4_error(inode
->i_sb
, "ext4_free_branches",
3770 "Read failure, inode=%lu, block=%llu",
3775 /* This zaps the entire block. Bottom up. */
3776 BUFFER_TRACE(bh
, "free child branches");
3777 ext4_free_branches(handle
, inode
, bh
,
3778 (__le32
*) bh
->b_data
,
3779 (__le32
*) bh
->b_data
+ addr_per_block
,
3783 * We've probably journalled the indirect block several
3784 * times during the truncate. But it's no longer
3785 * needed and we now drop it from the transaction via
3786 * jbd2_journal_revoke().
3788 * That's easy if it's exclusively part of this
3789 * transaction. But if it's part of the committing
3790 * transaction then jbd2_journal_forget() will simply
3791 * brelse() it. That means that if the underlying
3792 * block is reallocated in ext4_get_block(),
3793 * unmap_underlying_metadata() will find this block
3794 * and will try to get rid of it. damn, damn.
3796 * If this block has already been committed to the
3797 * journal, a revoke record will be written. And
3798 * revoke records must be emitted *before* clearing
3799 * this block's bit in the bitmaps.
3801 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
3804 * Everything below this this pointer has been
3805 * released. Now let this top-of-subtree go.
3807 * We want the freeing of this indirect block to be
3808 * atomic in the journal with the updating of the
3809 * bitmap block which owns it. So make some room in
3812 * We zero the parent pointer *after* freeing its
3813 * pointee in the bitmaps, so if extend_transaction()
3814 * for some reason fails to put the bitmap changes and
3815 * the release into the same transaction, recovery
3816 * will merely complain about releasing a free block,
3817 * rather than leaking blocks.
3819 if (ext4_handle_is_aborted(handle
))
3821 if (try_to_extend_transaction(handle
, inode
)) {
3822 ext4_mark_inode_dirty(handle
, inode
);
3823 ext4_journal_test_restart(handle
, inode
);
3826 ext4_free_blocks(handle
, inode
, nr
, 1, 1);
3830 * The block which we have just freed is
3831 * pointed to by an indirect block: journal it
3833 BUFFER_TRACE(parent_bh
, "get_write_access");
3834 if (!ext4_journal_get_write_access(handle
,
3837 BUFFER_TRACE(parent_bh
,
3838 "call ext4_handle_dirty_metadata");
3839 ext4_handle_dirty_metadata(handle
,
3846 /* We have reached the bottom of the tree. */
3847 BUFFER_TRACE(parent_bh
, "free data blocks");
3848 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
3852 int ext4_can_truncate(struct inode
*inode
)
3854 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
3856 if (S_ISREG(inode
->i_mode
))
3858 if (S_ISDIR(inode
->i_mode
))
3860 if (S_ISLNK(inode
->i_mode
))
3861 return !ext4_inode_is_fast_symlink(inode
);
3868 * We block out ext4_get_block() block instantiations across the entire
3869 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3870 * simultaneously on behalf of the same inode.
3872 * As we work through the truncate and commmit bits of it to the journal there
3873 * is one core, guiding principle: the file's tree must always be consistent on
3874 * disk. We must be able to restart the truncate after a crash.
3876 * The file's tree may be transiently inconsistent in memory (although it
3877 * probably isn't), but whenever we close off and commit a journal transaction,
3878 * the contents of (the filesystem + the journal) must be consistent and
3879 * restartable. It's pretty simple, really: bottom up, right to left (although
3880 * left-to-right works OK too).
3882 * Note that at recovery time, journal replay occurs *before* the restart of
3883 * truncate against the orphan inode list.
3885 * The committed inode has the new, desired i_size (which is the same as
3886 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3887 * that this inode's truncate did not complete and it will again call
3888 * ext4_truncate() to have another go. So there will be instantiated blocks
3889 * to the right of the truncation point in a crashed ext4 filesystem. But
3890 * that's fine - as long as they are linked from the inode, the post-crash
3891 * ext4_truncate() run will find them and release them.
3893 void ext4_truncate(struct inode
*inode
)
3896 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3897 __le32
*i_data
= ei
->i_data
;
3898 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
3899 struct address_space
*mapping
= inode
->i_mapping
;
3900 ext4_lblk_t offsets
[4];
3905 ext4_lblk_t last_block
;
3906 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
3908 if (!ext4_can_truncate(inode
))
3911 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
3912 ei
->i_state
|= EXT4_STATE_DA_ALLOC_CLOSE
;
3914 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
3915 ext4_ext_truncate(inode
);
3919 handle
= start_transaction(inode
);
3921 return; /* AKPM: return what? */
3923 last_block
= (inode
->i_size
+ blocksize
-1)
3924 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
3926 if (inode
->i_size
& (blocksize
- 1))
3927 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
3930 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
3932 goto out_stop
; /* error */
3935 * OK. This truncate is going to happen. We add the inode to the
3936 * orphan list, so that if this truncate spans multiple transactions,
3937 * and we crash, we will resume the truncate when the filesystem
3938 * recovers. It also marks the inode dirty, to catch the new size.
3940 * Implication: the file must always be in a sane, consistent
3941 * truncatable state while each transaction commits.
3943 if (ext4_orphan_add(handle
, inode
))
3947 * From here we block out all ext4_get_block() callers who want to
3948 * modify the block allocation tree.
3950 down_write(&ei
->i_data_sem
);
3952 ext4_discard_preallocations(inode
);
3955 * The orphan list entry will now protect us from any crash which
3956 * occurs before the truncate completes, so it is now safe to propagate
3957 * the new, shorter inode size (held for now in i_size) into the
3958 * on-disk inode. We do this via i_disksize, which is the value which
3959 * ext4 *really* writes onto the disk inode.
3961 ei
->i_disksize
= inode
->i_size
;
3963 if (n
== 1) { /* direct blocks */
3964 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
3965 i_data
+ EXT4_NDIR_BLOCKS
);
3969 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
3970 /* Kill the top of shared branch (not detached) */
3972 if (partial
== chain
) {
3973 /* Shared branch grows from the inode */
3974 ext4_free_branches(handle
, inode
, NULL
,
3975 &nr
, &nr
+1, (chain
+n
-1) - partial
);
3978 * We mark the inode dirty prior to restart,
3979 * and prior to stop. No need for it here.
3982 /* Shared branch grows from an indirect block */
3983 BUFFER_TRACE(partial
->bh
, "get_write_access");
3984 ext4_free_branches(handle
, inode
, partial
->bh
,
3986 partial
->p
+1, (chain
+n
-1) - partial
);
3989 /* Clear the ends of indirect blocks on the shared branch */
3990 while (partial
> chain
) {
3991 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
3992 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
3993 (chain
+n
-1) - partial
);
3994 BUFFER_TRACE(partial
->bh
, "call brelse");
3995 brelse (partial
->bh
);
3999 /* Kill the remaining (whole) subtrees */
4000 switch (offsets
[0]) {
4002 nr
= i_data
[EXT4_IND_BLOCK
];
4004 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4005 i_data
[EXT4_IND_BLOCK
] = 0;
4007 case EXT4_IND_BLOCK
:
4008 nr
= i_data
[EXT4_DIND_BLOCK
];
4010 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4011 i_data
[EXT4_DIND_BLOCK
] = 0;
4013 case EXT4_DIND_BLOCK
:
4014 nr
= i_data
[EXT4_TIND_BLOCK
];
4016 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4017 i_data
[EXT4_TIND_BLOCK
] = 0;
4019 case EXT4_TIND_BLOCK
:
4023 up_write(&ei
->i_data_sem
);
4024 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4025 ext4_mark_inode_dirty(handle
, inode
);
4028 * In a multi-transaction truncate, we only make the final transaction
4032 ext4_handle_sync(handle
);
4035 * If this was a simple ftruncate(), and the file will remain alive
4036 * then we need to clear up the orphan record which we created above.
4037 * However, if this was a real unlink then we were called by
4038 * ext4_delete_inode(), and we allow that function to clean up the
4039 * orphan info for us.
4042 ext4_orphan_del(handle
, inode
);
4044 ext4_journal_stop(handle
);
4048 * ext4_get_inode_loc returns with an extra refcount against the inode's
4049 * underlying buffer_head on success. If 'in_mem' is true, we have all
4050 * data in memory that is needed to recreate the on-disk version of this
4053 static int __ext4_get_inode_loc(struct inode
*inode
,
4054 struct ext4_iloc
*iloc
, int in_mem
)
4056 struct ext4_group_desc
*gdp
;
4057 struct buffer_head
*bh
;
4058 struct super_block
*sb
= inode
->i_sb
;
4060 int inodes_per_block
, inode_offset
;
4063 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4066 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4067 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4072 * Figure out the offset within the block group inode table
4074 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4075 inode_offset
= ((inode
->i_ino
- 1) %
4076 EXT4_INODES_PER_GROUP(sb
));
4077 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4078 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4080 bh
= sb_getblk(sb
, block
);
4082 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
4083 "inode block - inode=%lu, block=%llu",
4084 inode
->i_ino
, block
);
4087 if (!buffer_uptodate(bh
)) {
4091 * If the buffer has the write error flag, we have failed
4092 * to write out another inode in the same block. In this
4093 * case, we don't have to read the block because we may
4094 * read the old inode data successfully.
4096 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4097 set_buffer_uptodate(bh
);
4099 if (buffer_uptodate(bh
)) {
4100 /* someone brought it uptodate while we waited */
4106 * If we have all information of the inode in memory and this
4107 * is the only valid inode in the block, we need not read the
4111 struct buffer_head
*bitmap_bh
;
4114 start
= inode_offset
& ~(inodes_per_block
- 1);
4116 /* Is the inode bitmap in cache? */
4117 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4122 * If the inode bitmap isn't in cache then the
4123 * optimisation may end up performing two reads instead
4124 * of one, so skip it.
4126 if (!buffer_uptodate(bitmap_bh
)) {
4130 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4131 if (i
== inode_offset
)
4133 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4137 if (i
== start
+ inodes_per_block
) {
4138 /* all other inodes are free, so skip I/O */
4139 memset(bh
->b_data
, 0, bh
->b_size
);
4140 set_buffer_uptodate(bh
);
4148 * If we need to do any I/O, try to pre-readahead extra
4149 * blocks from the inode table.
4151 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4152 ext4_fsblk_t b
, end
, table
;
4155 table
= ext4_inode_table(sb
, gdp
);
4156 /* s_inode_readahead_blks is always a power of 2 */
4157 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4160 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4161 num
= EXT4_INODES_PER_GROUP(sb
);
4162 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4163 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4164 num
-= ext4_itable_unused_count(sb
, gdp
);
4165 table
+= num
/ inodes_per_block
;
4169 sb_breadahead(sb
, b
++);
4173 * There are other valid inodes in the buffer, this inode
4174 * has in-inode xattrs, or we don't have this inode in memory.
4175 * Read the block from disk.
4178 bh
->b_end_io
= end_buffer_read_sync
;
4179 submit_bh(READ_META
, bh
);
4181 if (!buffer_uptodate(bh
)) {
4182 ext4_error(sb
, __func__
,
4183 "unable to read inode block - inode=%lu, "
4184 "block=%llu", inode
->i_ino
, block
);
4194 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4196 /* We have all inode data except xattrs in memory here. */
4197 return __ext4_get_inode_loc(inode
, iloc
,
4198 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4201 void ext4_set_inode_flags(struct inode
*inode
)
4203 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4205 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4206 if (flags
& EXT4_SYNC_FL
)
4207 inode
->i_flags
|= S_SYNC
;
4208 if (flags
& EXT4_APPEND_FL
)
4209 inode
->i_flags
|= S_APPEND
;
4210 if (flags
& EXT4_IMMUTABLE_FL
)
4211 inode
->i_flags
|= S_IMMUTABLE
;
4212 if (flags
& EXT4_NOATIME_FL
)
4213 inode
->i_flags
|= S_NOATIME
;
4214 if (flags
& EXT4_DIRSYNC_FL
)
4215 inode
->i_flags
|= S_DIRSYNC
;
4218 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4219 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4221 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4223 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4224 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4226 ei
->i_flags
|= EXT4_SYNC_FL
;
4227 if (flags
& S_APPEND
)
4228 ei
->i_flags
|= EXT4_APPEND_FL
;
4229 if (flags
& S_IMMUTABLE
)
4230 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4231 if (flags
& S_NOATIME
)
4232 ei
->i_flags
|= EXT4_NOATIME_FL
;
4233 if (flags
& S_DIRSYNC
)
4234 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4236 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4237 struct ext4_inode_info
*ei
)
4240 struct inode
*inode
= &(ei
->vfs_inode
);
4241 struct super_block
*sb
= inode
->i_sb
;
4243 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4244 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4245 /* we are using combined 48 bit field */
4246 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4247 le32_to_cpu(raw_inode
->i_blocks_lo
);
4248 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4249 /* i_blocks represent file system block size */
4250 return i_blocks
<< (inode
->i_blkbits
- 9);
4255 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4259 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4261 struct ext4_iloc iloc
;
4262 struct ext4_inode
*raw_inode
;
4263 struct ext4_inode_info
*ei
;
4264 struct buffer_head
*bh
;
4265 struct inode
*inode
;
4269 inode
= iget_locked(sb
, ino
);
4271 return ERR_PTR(-ENOMEM
);
4272 if (!(inode
->i_state
& I_NEW
))
4276 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4277 ei
->i_acl
= EXT4_ACL_NOT_CACHED
;
4278 ei
->i_default_acl
= EXT4_ACL_NOT_CACHED
;
4281 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4285 raw_inode
= ext4_raw_inode(&iloc
);
4286 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4287 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4288 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4289 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4290 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4291 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4293 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4296 ei
->i_dir_start_lookup
= 0;
4297 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4298 /* We now have enough fields to check if the inode was active or not.
4299 * This is needed because nfsd might try to access dead inodes
4300 * the test is that same one that e2fsck uses
4301 * NeilBrown 1999oct15
4303 if (inode
->i_nlink
== 0) {
4304 if (inode
->i_mode
== 0 ||
4305 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4306 /* this inode is deleted */
4311 /* The only unlinked inodes we let through here have
4312 * valid i_mode and are being read by the orphan
4313 * recovery code: that's fine, we're about to complete
4314 * the process of deleting those. */
4316 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4317 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4318 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4319 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
4320 cpu_to_le32(EXT4_OS_HURD
)) {
4322 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4324 inode
->i_size
= ext4_isize(raw_inode
);
4325 ei
->i_disksize
= inode
->i_size
;
4326 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4327 ei
->i_block_group
= iloc
.block_group
;
4328 ei
->i_last_alloc_group
= ~0;
4330 * NOTE! The in-memory inode i_data array is in little-endian order
4331 * even on big-endian machines: we do NOT byteswap the block numbers!
4333 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4334 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4335 INIT_LIST_HEAD(&ei
->i_orphan
);
4337 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4338 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4339 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4340 EXT4_INODE_SIZE(inode
->i_sb
)) {
4345 if (ei
->i_extra_isize
== 0) {
4346 /* The extra space is currently unused. Use it. */
4347 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4348 EXT4_GOOD_OLD_INODE_SIZE
;
4350 __le32
*magic
= (void *)raw_inode
+
4351 EXT4_GOOD_OLD_INODE_SIZE
+
4353 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4354 ei
->i_state
|= EXT4_STATE_XATTR
;
4357 ei
->i_extra_isize
= 0;
4359 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4360 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4361 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4362 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4364 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4365 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4366 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4368 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4371 if (ei
->i_flags
& EXT4_EXTENTS_FL
) {
4372 /* Validate extent which is part of inode */
4373 ret
= ext4_ext_check_inode(inode
);
4381 if (S_ISREG(inode
->i_mode
)) {
4382 inode
->i_op
= &ext4_file_inode_operations
;
4383 inode
->i_fop
= &ext4_file_operations
;
4384 ext4_set_aops(inode
);
4385 } else if (S_ISDIR(inode
->i_mode
)) {
4386 inode
->i_op
= &ext4_dir_inode_operations
;
4387 inode
->i_fop
= &ext4_dir_operations
;
4388 } else if (S_ISLNK(inode
->i_mode
)) {
4389 if (ext4_inode_is_fast_symlink(inode
)) {
4390 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4391 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4392 sizeof(ei
->i_data
) - 1);
4394 inode
->i_op
= &ext4_symlink_inode_operations
;
4395 ext4_set_aops(inode
);
4397 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
4398 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
4399 inode
->i_op
= &ext4_special_inode_operations
;
4400 if (raw_inode
->i_block
[0])
4401 init_special_inode(inode
, inode
->i_mode
,
4402 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4404 init_special_inode(inode
, inode
->i_mode
,
4405 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4409 ext4_error(inode
->i_sb
, __func__
,
4410 "bogus i_mode (%o) for inode=%lu",
4411 inode
->i_mode
, inode
->i_ino
);
4415 ext4_set_inode_flags(inode
);
4416 unlock_new_inode(inode
);
4421 return ERR_PTR(ret
);
4424 static int ext4_inode_blocks_set(handle_t
*handle
,
4425 struct ext4_inode
*raw_inode
,
4426 struct ext4_inode_info
*ei
)
4428 struct inode
*inode
= &(ei
->vfs_inode
);
4429 u64 i_blocks
= inode
->i_blocks
;
4430 struct super_block
*sb
= inode
->i_sb
;
4432 if (i_blocks
<= ~0U) {
4434 * i_blocks can be represnted in a 32 bit variable
4435 * as multiple of 512 bytes
4437 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4438 raw_inode
->i_blocks_high
= 0;
4439 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4442 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
4445 if (i_blocks
<= 0xffffffffffffULL
) {
4447 * i_blocks can be represented in a 48 bit variable
4448 * as multiple of 512 bytes
4450 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4451 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4452 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4454 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
4455 /* i_block is stored in file system block size */
4456 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
4457 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4458 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4464 * Post the struct inode info into an on-disk inode location in the
4465 * buffer-cache. This gobbles the caller's reference to the
4466 * buffer_head in the inode location struct.
4468 * The caller must have write access to iloc->bh.
4470 static int ext4_do_update_inode(handle_t
*handle
,
4471 struct inode
*inode
,
4472 struct ext4_iloc
*iloc
)
4474 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
4475 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4476 struct buffer_head
*bh
= iloc
->bh
;
4477 int err
= 0, rc
, block
;
4479 /* For fields not not tracking in the in-memory inode,
4480 * initialise them to zero for new inodes. */
4481 if (ei
->i_state
& EXT4_STATE_NEW
)
4482 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
4484 ext4_get_inode_flags(ei
);
4485 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
4486 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4487 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
4488 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
4490 * Fix up interoperability with old kernels. Otherwise, old inodes get
4491 * re-used with the upper 16 bits of the uid/gid intact
4494 raw_inode
->i_uid_high
=
4495 cpu_to_le16(high_16_bits(inode
->i_uid
));
4496 raw_inode
->i_gid_high
=
4497 cpu_to_le16(high_16_bits(inode
->i_gid
));
4499 raw_inode
->i_uid_high
= 0;
4500 raw_inode
->i_gid_high
= 0;
4503 raw_inode
->i_uid_low
=
4504 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
4505 raw_inode
->i_gid_low
=
4506 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
4507 raw_inode
->i_uid_high
= 0;
4508 raw_inode
->i_gid_high
= 0;
4510 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
4512 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
4513 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
4514 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
4515 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
4517 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
4519 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
4520 /* clear the migrate flag in the raw_inode */
4521 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
& ~EXT4_EXT_MIGRATE
);
4522 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
4523 cpu_to_le32(EXT4_OS_HURD
))
4524 raw_inode
->i_file_acl_high
=
4525 cpu_to_le16(ei
->i_file_acl
>> 32);
4526 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
4527 ext4_isize_set(raw_inode
, ei
->i_disksize
);
4528 if (ei
->i_disksize
> 0x7fffffffULL
) {
4529 struct super_block
*sb
= inode
->i_sb
;
4530 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4531 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
4532 EXT4_SB(sb
)->s_es
->s_rev_level
==
4533 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
4534 /* If this is the first large file
4535 * created, add a flag to the superblock.
4537 err
= ext4_journal_get_write_access(handle
,
4538 EXT4_SB(sb
)->s_sbh
);
4541 ext4_update_dynamic_rev(sb
);
4542 EXT4_SET_RO_COMPAT_FEATURE(sb
,
4543 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
4545 ext4_handle_sync(handle
);
4546 err
= ext4_handle_dirty_metadata(handle
, inode
,
4547 EXT4_SB(sb
)->s_sbh
);
4550 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
4551 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
4552 if (old_valid_dev(inode
->i_rdev
)) {
4553 raw_inode
->i_block
[0] =
4554 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
4555 raw_inode
->i_block
[1] = 0;
4557 raw_inode
->i_block
[0] = 0;
4558 raw_inode
->i_block
[1] =
4559 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
4560 raw_inode
->i_block
[2] = 0;
4562 } else for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4563 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
4565 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
4566 if (ei
->i_extra_isize
) {
4567 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4568 raw_inode
->i_version_hi
=
4569 cpu_to_le32(inode
->i_version
>> 32);
4570 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
4573 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4574 rc
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
4577 ei
->i_state
&= ~EXT4_STATE_NEW
;
4581 ext4_std_error(inode
->i_sb
, err
);
4586 * ext4_write_inode()
4588 * We are called from a few places:
4590 * - Within generic_file_write() for O_SYNC files.
4591 * Here, there will be no transaction running. We wait for any running
4592 * trasnaction to commit.
4594 * - Within sys_sync(), kupdate and such.
4595 * We wait on commit, if tol to.
4597 * - Within prune_icache() (PF_MEMALLOC == true)
4598 * Here we simply return. We can't afford to block kswapd on the
4601 * In all cases it is actually safe for us to return without doing anything,
4602 * because the inode has been copied into a raw inode buffer in
4603 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4606 * Note that we are absolutely dependent upon all inode dirtiers doing the
4607 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4608 * which we are interested.
4610 * It would be a bug for them to not do this. The code:
4612 * mark_inode_dirty(inode)
4614 * inode->i_size = expr;
4616 * is in error because a kswapd-driven write_inode() could occur while
4617 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4618 * will no longer be on the superblock's dirty inode list.
4620 int ext4_write_inode(struct inode
*inode
, int wait
)
4622 if (current
->flags
& PF_MEMALLOC
)
4625 if (ext4_journal_current_handle()) {
4626 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4634 return ext4_force_commit(inode
->i_sb
);
4637 int __ext4_write_dirty_metadata(struct inode
*inode
, struct buffer_head
*bh
)
4641 mark_buffer_dirty(bh
);
4642 if (inode
&& inode_needs_sync(inode
)) {
4643 sync_dirty_buffer(bh
);
4644 if (buffer_req(bh
) && !buffer_uptodate(bh
)) {
4645 ext4_error(inode
->i_sb
, __func__
,
4646 "IO error syncing inode, "
4647 "inode=%lu, block=%llu",
4649 (unsigned long long)bh
->b_blocknr
);
4659 * Called from notify_change.
4661 * We want to trap VFS attempts to truncate the file as soon as
4662 * possible. In particular, we want to make sure that when the VFS
4663 * shrinks i_size, we put the inode on the orphan list and modify
4664 * i_disksize immediately, so that during the subsequent flushing of
4665 * dirty pages and freeing of disk blocks, we can guarantee that any
4666 * commit will leave the blocks being flushed in an unused state on
4667 * disk. (On recovery, the inode will get truncated and the blocks will
4668 * be freed, so we have a strong guarantee that no future commit will
4669 * leave these blocks visible to the user.)
4671 * Another thing we have to assure is that if we are in ordered mode
4672 * and inode is still attached to the committing transaction, we must
4673 * we start writeout of all the dirty pages which are being truncated.
4674 * This way we are sure that all the data written in the previous
4675 * transaction are already on disk (truncate waits for pages under
4678 * Called with inode->i_mutex down.
4680 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
4682 struct inode
*inode
= dentry
->d_inode
;
4684 const unsigned int ia_valid
= attr
->ia_valid
;
4686 error
= inode_change_ok(inode
, attr
);
4690 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
4691 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
4694 /* (user+group)*(old+new) structure, inode write (sb,
4695 * inode block, ? - but truncate inode update has it) */
4696 handle
= ext4_journal_start(inode
, 2*(EXT4_QUOTA_INIT_BLOCKS(inode
->i_sb
)+
4697 EXT4_QUOTA_DEL_BLOCKS(inode
->i_sb
))+3);
4698 if (IS_ERR(handle
)) {
4699 error
= PTR_ERR(handle
);
4702 error
= vfs_dq_transfer(inode
, attr
) ? -EDQUOT
: 0;
4704 ext4_journal_stop(handle
);
4707 /* Update corresponding info in inode so that everything is in
4708 * one transaction */
4709 if (attr
->ia_valid
& ATTR_UID
)
4710 inode
->i_uid
= attr
->ia_uid
;
4711 if (attr
->ia_valid
& ATTR_GID
)
4712 inode
->i_gid
= attr
->ia_gid
;
4713 error
= ext4_mark_inode_dirty(handle
, inode
);
4714 ext4_journal_stop(handle
);
4717 if (attr
->ia_valid
& ATTR_SIZE
) {
4718 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
4719 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
4721 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
4728 if (S_ISREG(inode
->i_mode
) &&
4729 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
4732 handle
= ext4_journal_start(inode
, 3);
4733 if (IS_ERR(handle
)) {
4734 error
= PTR_ERR(handle
);
4738 error
= ext4_orphan_add(handle
, inode
);
4739 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
4740 rc
= ext4_mark_inode_dirty(handle
, inode
);
4743 ext4_journal_stop(handle
);
4745 if (ext4_should_order_data(inode
)) {
4746 error
= ext4_begin_ordered_truncate(inode
,
4749 /* Do as much error cleanup as possible */
4750 handle
= ext4_journal_start(inode
, 3);
4751 if (IS_ERR(handle
)) {
4752 ext4_orphan_del(NULL
, inode
);
4755 ext4_orphan_del(handle
, inode
);
4756 ext4_journal_stop(handle
);
4762 rc
= inode_setattr(inode
, attr
);
4764 /* If inode_setattr's call to ext4_truncate failed to get a
4765 * transaction handle at all, we need to clean up the in-core
4766 * orphan list manually. */
4768 ext4_orphan_del(NULL
, inode
);
4770 if (!rc
&& (ia_valid
& ATTR_MODE
))
4771 rc
= ext4_acl_chmod(inode
);
4774 ext4_std_error(inode
->i_sb
, error
);
4780 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
4783 struct inode
*inode
;
4784 unsigned long delalloc_blocks
;
4786 inode
= dentry
->d_inode
;
4787 generic_fillattr(inode
, stat
);
4790 * We can't update i_blocks if the block allocation is delayed
4791 * otherwise in the case of system crash before the real block
4792 * allocation is done, we will have i_blocks inconsistent with
4793 * on-disk file blocks.
4794 * We always keep i_blocks updated together with real
4795 * allocation. But to not confuse with user, stat
4796 * will return the blocks that include the delayed allocation
4797 * blocks for this file.
4799 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
4800 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
4801 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
4803 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
4807 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
4812 /* if nrblocks are contiguous */
4815 * With N contiguous data blocks, it need at most
4816 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
4817 * 2 dindirect blocks
4820 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4821 return indirects
+ 3;
4824 * if nrblocks are not contiguous, worse case, each block touch
4825 * a indirect block, and each indirect block touch a double indirect
4826 * block, plus a triple indirect block
4828 indirects
= nrblocks
* 2 + 1;
4832 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4834 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
4835 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
4836 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
4840 * Account for index blocks, block groups bitmaps and block group
4841 * descriptor blocks if modify datablocks and index blocks
4842 * worse case, the indexs blocks spread over different block groups
4844 * If datablocks are discontiguous, they are possible to spread over
4845 * different block groups too. If they are contiugous, with flexbg,
4846 * they could still across block group boundary.
4848 * Also account for superblock, inode, quota and xattr blocks
4850 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4852 int groups
, gdpblocks
;
4857 * How many index blocks need to touch to modify nrblocks?
4858 * The "Chunk" flag indicating whether the nrblocks is
4859 * physically contiguous on disk
4861 * For Direct IO and fallocate, they calls get_block to allocate
4862 * one single extent at a time, so they could set the "Chunk" flag
4864 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
4869 * Now let's see how many group bitmaps and group descriptors need
4879 if (groups
> EXT4_SB(inode
->i_sb
)->s_groups_count
)
4880 groups
= EXT4_SB(inode
->i_sb
)->s_groups_count
;
4881 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
4882 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
4884 /* bitmaps and block group descriptor blocks */
4885 ret
+= groups
+ gdpblocks
;
4887 /* Blocks for super block, inode, quota and xattr blocks */
4888 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
4894 * Calulate the total number of credits to reserve to fit
4895 * the modification of a single pages into a single transaction,
4896 * which may include multiple chunks of block allocations.
4898 * This could be called via ext4_write_begin()
4900 * We need to consider the worse case, when
4901 * one new block per extent.
4903 int ext4_writepage_trans_blocks(struct inode
*inode
)
4905 int bpp
= ext4_journal_blocks_per_page(inode
);
4908 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
4910 /* Account for data blocks for journalled mode */
4911 if (ext4_should_journal_data(inode
))
4917 * Calculate the journal credits for a chunk of data modification.
4919 * This is called from DIO, fallocate or whoever calling
4920 * ext4_get_blocks_wrap() to map/allocate a chunk of contigous disk blocks.
4922 * journal buffers for data blocks are not included here, as DIO
4923 * and fallocate do no need to journal data buffers.
4925 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
4927 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
4931 * The caller must have previously called ext4_reserve_inode_write().
4932 * Give this, we know that the caller already has write access to iloc->bh.
4934 int ext4_mark_iloc_dirty(handle_t
*handle
,
4935 struct inode
*inode
, struct ext4_iloc
*iloc
)
4939 if (test_opt(inode
->i_sb
, I_VERSION
))
4940 inode_inc_iversion(inode
);
4942 /* the do_update_inode consumes one bh->b_count */
4945 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4946 err
= ext4_do_update_inode(handle
, inode
, iloc
);
4952 * On success, We end up with an outstanding reference count against
4953 * iloc->bh. This _must_ be cleaned up later.
4957 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
4958 struct ext4_iloc
*iloc
)
4962 err
= ext4_get_inode_loc(inode
, iloc
);
4964 BUFFER_TRACE(iloc
->bh
, "get_write_access");
4965 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
4971 ext4_std_error(inode
->i_sb
, err
);
4976 * Expand an inode by new_extra_isize bytes.
4977 * Returns 0 on success or negative error number on failure.
4979 static int ext4_expand_extra_isize(struct inode
*inode
,
4980 unsigned int new_extra_isize
,
4981 struct ext4_iloc iloc
,
4984 struct ext4_inode
*raw_inode
;
4985 struct ext4_xattr_ibody_header
*header
;
4986 struct ext4_xattr_entry
*entry
;
4988 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
4991 raw_inode
= ext4_raw_inode(&iloc
);
4993 header
= IHDR(inode
, raw_inode
);
4994 entry
= IFIRST(header
);
4996 /* No extended attributes present */
4997 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
4998 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
4999 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5001 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5005 /* try to expand with EAs present */
5006 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5011 * What we do here is to mark the in-core inode as clean with respect to inode
5012 * dirtiness (it may still be data-dirty).
5013 * This means that the in-core inode may be reaped by prune_icache
5014 * without having to perform any I/O. This is a very good thing,
5015 * because *any* task may call prune_icache - even ones which
5016 * have a transaction open against a different journal.
5018 * Is this cheating? Not really. Sure, we haven't written the
5019 * inode out, but prune_icache isn't a user-visible syncing function.
5020 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5021 * we start and wait on commits.
5023 * Is this efficient/effective? Well, we're being nice to the system
5024 * by cleaning up our inodes proactively so they can be reaped
5025 * without I/O. But we are potentially leaving up to five seconds'
5026 * worth of inodes floating about which prune_icache wants us to
5027 * write out. One way to fix that would be to get prune_icache()
5028 * to do a write_super() to free up some memory. It has the desired
5031 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5033 struct ext4_iloc iloc
;
5034 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5035 static unsigned int mnt_count
;
5039 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5040 if (ext4_handle_valid(handle
) &&
5041 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5042 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
5044 * We need extra buffer credits since we may write into EA block
5045 * with this same handle. If journal_extend fails, then it will
5046 * only result in a minor loss of functionality for that inode.
5047 * If this is felt to be critical, then e2fsck should be run to
5048 * force a large enough s_min_extra_isize.
5050 if ((jbd2_journal_extend(handle
,
5051 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5052 ret
= ext4_expand_extra_isize(inode
,
5053 sbi
->s_want_extra_isize
,
5056 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
5058 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5059 ext4_warning(inode
->i_sb
, __func__
,
5060 "Unable to expand inode %lu. Delete"
5061 " some EAs or run e2fsck.",
5064 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5070 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5075 * ext4_dirty_inode() is called from __mark_inode_dirty()
5077 * We're really interested in the case where a file is being extended.
5078 * i_size has been changed by generic_commit_write() and we thus need
5079 * to include the updated inode in the current transaction.
5081 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
5082 * are allocated to the file.
5084 * If the inode is marked synchronous, we don't honour that here - doing
5085 * so would cause a commit on atime updates, which we don't bother doing.
5086 * We handle synchronous inodes at the highest possible level.
5088 void ext4_dirty_inode(struct inode
*inode
)
5090 handle_t
*current_handle
= ext4_journal_current_handle();
5093 if (!ext4_handle_valid(current_handle
)) {
5094 ext4_mark_inode_dirty(current_handle
, inode
);
5098 handle
= ext4_journal_start(inode
, 2);
5101 if (current_handle
&&
5102 current_handle
->h_transaction
!= handle
->h_transaction
) {
5103 /* This task has a transaction open against a different fs */
5104 printk(KERN_EMERG
"%s: transactions do not match!\n",
5107 jbd_debug(5, "marking dirty. outer handle=%p\n",
5109 ext4_mark_inode_dirty(handle
, inode
);
5111 ext4_journal_stop(handle
);
5118 * Bind an inode's backing buffer_head into this transaction, to prevent
5119 * it from being flushed to disk early. Unlike
5120 * ext4_reserve_inode_write, this leaves behind no bh reference and
5121 * returns no iloc structure, so the caller needs to repeat the iloc
5122 * lookup to mark the inode dirty later.
5124 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5126 struct ext4_iloc iloc
;
5130 err
= ext4_get_inode_loc(inode
, &iloc
);
5132 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5133 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5135 err
= ext4_handle_dirty_metadata(handle
,
5141 ext4_std_error(inode
->i_sb
, err
);
5146 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5153 * We have to be very careful here: changing a data block's
5154 * journaling status dynamically is dangerous. If we write a
5155 * data block to the journal, change the status and then delete
5156 * that block, we risk forgetting to revoke the old log record
5157 * from the journal and so a subsequent replay can corrupt data.
5158 * So, first we make sure that the journal is empty and that
5159 * nobody is changing anything.
5162 journal
= EXT4_JOURNAL(inode
);
5165 if (is_journal_aborted(journal
))
5168 jbd2_journal_lock_updates(journal
);
5169 jbd2_journal_flush(journal
);
5172 * OK, there are no updates running now, and all cached data is
5173 * synced to disk. We are now in a completely consistent state
5174 * which doesn't have anything in the journal, and we know that
5175 * no filesystem updates are running, so it is safe to modify
5176 * the inode's in-core data-journaling state flag now.
5180 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
5182 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
5183 ext4_set_aops(inode
);
5185 jbd2_journal_unlock_updates(journal
);
5187 /* Finally we can mark the inode as dirty. */
5189 handle
= ext4_journal_start(inode
, 1);
5191 return PTR_ERR(handle
);
5193 err
= ext4_mark_inode_dirty(handle
, inode
);
5194 ext4_handle_sync(handle
);
5195 ext4_journal_stop(handle
);
5196 ext4_std_error(inode
->i_sb
, err
);
5201 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5203 return !buffer_mapped(bh
);
5206 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct page
*page
)
5212 struct file
*file
= vma
->vm_file
;
5213 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5214 struct address_space
*mapping
= inode
->i_mapping
;
5217 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5218 * get i_mutex because we are already holding mmap_sem.
5220 down_read(&inode
->i_alloc_sem
);
5221 size
= i_size_read(inode
);
5222 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5223 || !PageUptodate(page
)) {
5224 /* page got truncated from under us? */
5228 if (PageMappedToDisk(page
))
5231 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5232 len
= size
& ~PAGE_CACHE_MASK
;
5234 len
= PAGE_CACHE_SIZE
;
5236 if (page_has_buffers(page
)) {
5237 /* return if we have all the buffers mapped */
5238 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5243 * OK, we need to fill the hole... Do write_begin write_end
5244 * to do block allocation/reservation.We are not holding
5245 * inode.i__mutex here. That allow * parallel write_begin,
5246 * write_end call. lock_page prevent this from happening
5247 * on the same page though
5249 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5250 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5253 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5254 len
, len
, page
, fsdata
);
5259 up_read(&inode
->i_alloc_sem
);