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>
41 #include "ext4_jbd2.h"
44 #include "ext4_extents.h"
46 #include <trace/events/ext4.h>
48 #define MPAGE_DA_EXTENT_TAIL 0x01
50 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
53 return jbd2_journal_begin_ordered_truncate(
54 EXT4_SB(inode
->i_sb
)->s_journal
,
55 &EXT4_I(inode
)->jinode
,
59 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
62 * Test whether an inode is a fast symlink.
64 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
66 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
67 (inode
->i_sb
->s_blocksize
>> 9) : 0;
69 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
73 * The ext4 forget function must perform a revoke if we are freeing data
74 * which has been journaled. Metadata (eg. indirect blocks) must be
75 * revoked in all cases.
77 * "bh" may be NULL: a metadata block may have been freed from memory
78 * but there may still be a record of it in the journal, and that record
79 * still needs to be revoked.
81 * If the handle isn't valid we're not journaling so there's nothing to do.
83 int ext4_forget(handle_t
*handle
, int is_metadata
, struct inode
*inode
,
84 struct buffer_head
*bh
, ext4_fsblk_t blocknr
)
88 if (!ext4_handle_valid(handle
))
93 BUFFER_TRACE(bh
, "enter");
95 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
97 bh
, is_metadata
, inode
->i_mode
,
98 test_opt(inode
->i_sb
, DATA_FLAGS
));
100 /* Never use the revoke function if we are doing full data
101 * journaling: there is no need to, and a V1 superblock won't
102 * support it. Otherwise, only skip the revoke on un-journaled
105 if (test_opt(inode
->i_sb
, DATA_FLAGS
) == EXT4_MOUNT_JOURNAL_DATA
||
106 (!is_metadata
&& !ext4_should_journal_data(inode
))) {
108 BUFFER_TRACE(bh
, "call jbd2_journal_forget");
109 return ext4_journal_forget(handle
, bh
);
115 * data!=journal && (is_metadata || should_journal_data(inode))
117 BUFFER_TRACE(bh
, "call ext4_journal_revoke");
118 err
= ext4_journal_revoke(handle
, blocknr
, bh
);
120 ext4_abort(inode
->i_sb
, __func__
,
121 "error %d when attempting revoke", err
);
122 BUFFER_TRACE(bh
, "exit");
127 * Work out how many blocks we need to proceed with the next chunk of a
128 * truncate transaction.
130 static unsigned long blocks_for_truncate(struct inode
*inode
)
134 needed
= inode
->i_blocks
>> (inode
->i_sb
->s_blocksize_bits
- 9);
136 /* Give ourselves just enough room to cope with inodes in which
137 * i_blocks is corrupt: we've seen disk corruptions in the past
138 * which resulted in random data in an inode which looked enough
139 * like a regular file for ext4 to try to delete it. Things
140 * will go a bit crazy if that happens, but at least we should
141 * try not to panic the whole kernel. */
145 /* But we need to bound the transaction so we don't overflow the
147 if (needed
> EXT4_MAX_TRANS_DATA
)
148 needed
= EXT4_MAX_TRANS_DATA
;
150 return EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + needed
;
154 * Truncate transactions can be complex and absolutely huge. So we need to
155 * be able to restart the transaction at a conventient checkpoint to make
156 * sure we don't overflow the journal.
158 * start_transaction gets us a new handle for a truncate transaction,
159 * and extend_transaction tries to extend the existing one a bit. If
160 * extend fails, we need to propagate the failure up and restart the
161 * transaction in the top-level truncate loop. --sct
163 static handle_t
*start_transaction(struct inode
*inode
)
167 result
= ext4_journal_start(inode
, blocks_for_truncate(inode
));
171 ext4_std_error(inode
->i_sb
, PTR_ERR(result
));
176 * Try to extend this transaction for the purposes of truncation.
178 * Returns 0 if we managed to create more room. If we can't create more
179 * room, and the transaction must be restarted we return 1.
181 static int try_to_extend_transaction(handle_t
*handle
, struct inode
*inode
)
183 if (!ext4_handle_valid(handle
))
185 if (ext4_handle_has_enough_credits(handle
, EXT4_RESERVE_TRANS_BLOCKS
+1))
187 if (!ext4_journal_extend(handle
, blocks_for_truncate(inode
)))
193 * Restart the transaction associated with *handle. This does a commit,
194 * so before we call here everything must be consistently dirtied against
197 static int ext4_journal_test_restart(handle_t
*handle
, struct inode
*inode
)
199 BUG_ON(EXT4_JOURNAL(inode
) == NULL
);
200 jbd_debug(2, "restarting handle %p\n", handle
);
201 return ext4_journal_restart(handle
, blocks_for_truncate(inode
));
205 * Called at the last iput() if i_nlink is zero.
207 void ext4_delete_inode(struct inode
*inode
)
212 if (ext4_should_order_data(inode
))
213 ext4_begin_ordered_truncate(inode
, 0);
214 truncate_inode_pages(&inode
->i_data
, 0);
216 if (is_bad_inode(inode
))
219 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
220 if (IS_ERR(handle
)) {
221 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
223 * If we're going to skip the normal cleanup, we still need to
224 * make sure that the in-core orphan linked list is properly
227 ext4_orphan_del(NULL
, inode
);
232 ext4_handle_sync(handle
);
234 err
= ext4_mark_inode_dirty(handle
, inode
);
236 ext4_warning(inode
->i_sb
, __func__
,
237 "couldn't mark inode dirty (err %d)", err
);
241 ext4_truncate(inode
);
244 * ext4_ext_truncate() doesn't reserve any slop when it
245 * restarts journal transactions; therefore there may not be
246 * enough credits left in the handle to remove the inode from
247 * the orphan list and set the dtime field.
249 if (!ext4_handle_has_enough_credits(handle
, 3)) {
250 err
= ext4_journal_extend(handle
, 3);
252 err
= ext4_journal_restart(handle
, 3);
254 ext4_warning(inode
->i_sb
, __func__
,
255 "couldn't extend journal (err %d)", err
);
257 ext4_journal_stop(handle
);
263 * Kill off the orphan record which ext4_truncate created.
264 * AKPM: I think this can be inside the above `if'.
265 * Note that ext4_orphan_del() has to be able to cope with the
266 * deletion of a non-existent orphan - this is because we don't
267 * know if ext4_truncate() actually created an orphan record.
268 * (Well, we could do this if we need to, but heck - it works)
270 ext4_orphan_del(handle
, inode
);
271 EXT4_I(inode
)->i_dtime
= get_seconds();
274 * One subtle ordering requirement: if anything has gone wrong
275 * (transaction abort, IO errors, whatever), then we can still
276 * do these next steps (the fs will already have been marked as
277 * having errors), but we can't free the inode if the mark_dirty
280 if (ext4_mark_inode_dirty(handle
, inode
))
281 /* If that failed, just do the required in-core inode clear. */
284 ext4_free_inode(handle
, inode
);
285 ext4_journal_stop(handle
);
288 clear_inode(inode
); /* We must guarantee clearing of inode... */
294 struct buffer_head
*bh
;
297 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
299 p
->key
= *(p
->p
= v
);
304 * ext4_block_to_path - parse the block number into array of offsets
305 * @inode: inode in question (we are only interested in its superblock)
306 * @i_block: block number to be parsed
307 * @offsets: array to store the offsets in
308 * @boundary: set this non-zero if the referred-to block is likely to be
309 * followed (on disk) by an indirect block.
311 * To store the locations of file's data ext4 uses a data structure common
312 * for UNIX filesystems - tree of pointers anchored in the inode, with
313 * data blocks at leaves and indirect blocks in intermediate nodes.
314 * This function translates the block number into path in that tree -
315 * return value is the path length and @offsets[n] is the offset of
316 * pointer to (n+1)th node in the nth one. If @block is out of range
317 * (negative or too large) warning is printed and zero returned.
319 * Note: function doesn't find node addresses, so no IO is needed. All
320 * we need to know is the capacity of indirect blocks (taken from the
325 * Portability note: the last comparison (check that we fit into triple
326 * indirect block) is spelled differently, because otherwise on an
327 * architecture with 32-bit longs and 8Kb pages we might get into trouble
328 * if our filesystem had 8Kb blocks. We might use long long, but that would
329 * kill us on x86. Oh, well, at least the sign propagation does not matter -
330 * i_block would have to be negative in the very beginning, so we would not
334 static int ext4_block_to_path(struct inode
*inode
,
336 ext4_lblk_t offsets
[4], int *boundary
)
338 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
339 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
340 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
341 indirect_blocks
= ptrs
,
342 double_blocks
= (1 << (ptrs_bits
* 2));
347 ext4_warning(inode
->i_sb
, "ext4_block_to_path", "block < 0");
348 } else if (i_block
< direct_blocks
) {
349 offsets
[n
++] = i_block
;
350 final
= direct_blocks
;
351 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
352 offsets
[n
++] = EXT4_IND_BLOCK
;
353 offsets
[n
++] = i_block
;
355 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
356 offsets
[n
++] = EXT4_DIND_BLOCK
;
357 offsets
[n
++] = i_block
>> ptrs_bits
;
358 offsets
[n
++] = i_block
& (ptrs
- 1);
360 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
361 offsets
[n
++] = EXT4_TIND_BLOCK
;
362 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
363 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
364 offsets
[n
++] = i_block
& (ptrs
- 1);
367 ext4_warning(inode
->i_sb
, "ext4_block_to_path",
368 "block %lu > max in inode %lu",
369 i_block
+ direct_blocks
+
370 indirect_blocks
+ double_blocks
, inode
->i_ino
);
373 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
377 static int __ext4_check_blockref(const char *function
, struct inode
*inode
,
378 __le32
*p
, unsigned int max
)
383 while (bref
< p
+max
) {
384 blk
= le32_to_cpu(*bref
++);
386 unlikely(!ext4_data_block_valid(EXT4_SB(inode
->i_sb
),
388 ext4_error(inode
->i_sb
, function
,
389 "invalid block reference %u "
390 "in inode #%lu", blk
, inode
->i_ino
);
398 #define ext4_check_indirect_blockref(inode, bh) \
399 __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data, \
400 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
402 #define ext4_check_inode_blockref(inode) \
403 __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data, \
407 * ext4_get_branch - read the chain of indirect blocks leading to data
408 * @inode: inode in question
409 * @depth: depth of the chain (1 - direct pointer, etc.)
410 * @offsets: offsets of pointers in inode/indirect blocks
411 * @chain: place to store the result
412 * @err: here we store the error value
414 * Function fills the array of triples <key, p, bh> and returns %NULL
415 * if everything went OK or the pointer to the last filled triple
416 * (incomplete one) otherwise. Upon the return chain[i].key contains
417 * the number of (i+1)-th block in the chain (as it is stored in memory,
418 * i.e. little-endian 32-bit), chain[i].p contains the address of that
419 * number (it points into struct inode for i==0 and into the bh->b_data
420 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
421 * block for i>0 and NULL for i==0. In other words, it holds the block
422 * numbers of the chain, addresses they were taken from (and where we can
423 * verify that chain did not change) and buffer_heads hosting these
426 * Function stops when it stumbles upon zero pointer (absent block)
427 * (pointer to last triple returned, *@err == 0)
428 * or when it gets an IO error reading an indirect block
429 * (ditto, *@err == -EIO)
430 * or when it reads all @depth-1 indirect blocks successfully and finds
431 * the whole chain, all way to the data (returns %NULL, *err == 0).
433 * Need to be called with
434 * down_read(&EXT4_I(inode)->i_data_sem)
436 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
437 ext4_lblk_t
*offsets
,
438 Indirect chain
[4], int *err
)
440 struct super_block
*sb
= inode
->i_sb
;
442 struct buffer_head
*bh
;
445 /* i_data is not going away, no lock needed */
446 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
450 bh
= sb_getblk(sb
, le32_to_cpu(p
->key
));
454 if (!bh_uptodate_or_lock(bh
)) {
455 if (bh_submit_read(bh
) < 0) {
459 /* validate block references */
460 if (ext4_check_indirect_blockref(inode
, bh
)) {
466 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
480 * ext4_find_near - find a place for allocation with sufficient locality
482 * @ind: descriptor of indirect block.
484 * This function returns the preferred place for block allocation.
485 * It is used when heuristic for sequential allocation fails.
487 * + if there is a block to the left of our position - allocate near it.
488 * + if pointer will live in indirect block - allocate near that block.
489 * + if pointer will live in inode - allocate in the same
492 * In the latter case we colour the starting block by the callers PID to
493 * prevent it from clashing with concurrent allocations for a different inode
494 * in the same block group. The PID is used here so that functionally related
495 * files will be close-by on-disk.
497 * Caller must make sure that @ind is valid and will stay that way.
499 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
501 struct ext4_inode_info
*ei
= EXT4_I(inode
);
502 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
504 ext4_fsblk_t bg_start
;
505 ext4_fsblk_t last_block
;
506 ext4_grpblk_t colour
;
507 ext4_group_t block_group
;
508 int flex_size
= ext4_flex_bg_size(EXT4_SB(inode
->i_sb
));
510 /* Try to find previous block */
511 for (p
= ind
->p
- 1; p
>= start
; p
--) {
513 return le32_to_cpu(*p
);
516 /* No such thing, so let's try location of indirect block */
518 return ind
->bh
->b_blocknr
;
521 * It is going to be referred to from the inode itself? OK, just put it
522 * into the same cylinder group then.
524 block_group
= ei
->i_block_group
;
525 if (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) {
526 block_group
&= ~(flex_size
-1);
527 if (S_ISREG(inode
->i_mode
))
530 bg_start
= ext4_group_first_block_no(inode
->i_sb
, block_group
);
531 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
534 * If we are doing delayed allocation, we don't need take
535 * colour into account.
537 if (test_opt(inode
->i_sb
, DELALLOC
))
540 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
541 colour
= (current
->pid
% 16) *
542 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
544 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
545 return bg_start
+ colour
;
549 * ext4_find_goal - find a preferred place for allocation.
551 * @block: block we want
552 * @partial: pointer to the last triple within a chain
554 * Normally this function find the preferred place for block allocation,
557 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
561 * XXX need to get goal block from mballoc's data structures
564 return ext4_find_near(inode
, partial
);
568 * ext4_blks_to_allocate: Look up the block map and count the number
569 * of direct blocks need to be allocated for the given branch.
571 * @branch: chain of indirect blocks
572 * @k: number of blocks need for indirect blocks
573 * @blks: number of data blocks to be mapped.
574 * @blocks_to_boundary: the offset in the indirect block
576 * return the total number of blocks to be allocate, including the
577 * direct and indirect blocks.
579 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned int blks
,
580 int blocks_to_boundary
)
582 unsigned int count
= 0;
585 * Simple case, [t,d]Indirect block(s) has not allocated yet
586 * then it's clear blocks on that path have not allocated
589 /* right now we don't handle cross boundary allocation */
590 if (blks
< blocks_to_boundary
+ 1)
593 count
+= blocks_to_boundary
+ 1;
598 while (count
< blks
&& count
<= blocks_to_boundary
&&
599 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
606 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
607 * @indirect_blks: the number of blocks need to allocate for indirect
610 * @new_blocks: on return it will store the new block numbers for
611 * the indirect blocks(if needed) and the first direct block,
612 * @blks: on return it will store the total number of allocated
615 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
616 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
617 int indirect_blks
, int blks
,
618 ext4_fsblk_t new_blocks
[4], int *err
)
620 struct ext4_allocation_request ar
;
622 unsigned long count
= 0, blk_allocated
= 0;
624 ext4_fsblk_t current_block
= 0;
628 * Here we try to allocate the requested multiple blocks at once,
629 * on a best-effort basis.
630 * To build a branch, we should allocate blocks for
631 * the indirect blocks(if not allocated yet), and at least
632 * the first direct block of this branch. That's the
633 * minimum number of blocks need to allocate(required)
635 /* first we try to allocate the indirect blocks */
636 target
= indirect_blks
;
639 /* allocating blocks for indirect blocks and direct blocks */
640 current_block
= ext4_new_meta_blocks(handle
, inode
,
646 /* allocate blocks for indirect blocks */
647 while (index
< indirect_blks
&& count
) {
648 new_blocks
[index
++] = current_block
++;
653 * save the new block number
654 * for the first direct block
656 new_blocks
[index
] = current_block
;
657 printk(KERN_INFO
"%s returned more blocks than "
658 "requested\n", __func__
);
664 target
= blks
- count
;
665 blk_allocated
= count
;
668 /* Now allocate data blocks */
669 memset(&ar
, 0, sizeof(ar
));
674 if (S_ISREG(inode
->i_mode
))
675 /* enable in-core preallocation only for regular files */
676 ar
.flags
= EXT4_MB_HINT_DATA
;
678 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
680 if (*err
&& (target
== blks
)) {
682 * if the allocation failed and we didn't allocate
688 if (target
== blks
) {
690 * save the new block number
691 * for the first direct block
693 new_blocks
[index
] = current_block
;
695 blk_allocated
+= ar
.len
;
698 /* total number of blocks allocated for direct blocks */
703 for (i
= 0; i
< index
; i
++)
704 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
709 * ext4_alloc_branch - allocate and set up a chain of blocks.
711 * @indirect_blks: number of allocated indirect blocks
712 * @blks: number of allocated direct blocks
713 * @offsets: offsets (in the blocks) to store the pointers to next.
714 * @branch: place to store the chain in.
716 * This function allocates blocks, zeroes out all but the last one,
717 * links them into chain and (if we are synchronous) writes them to disk.
718 * In other words, it prepares a branch that can be spliced onto the
719 * inode. It stores the information about that chain in the branch[], in
720 * the same format as ext4_get_branch() would do. We are calling it after
721 * we had read the existing part of chain and partial points to the last
722 * triple of that (one with zero ->key). Upon the exit we have the same
723 * picture as after the successful ext4_get_block(), except that in one
724 * place chain is disconnected - *branch->p is still zero (we did not
725 * set the last link), but branch->key contains the number that should
726 * be placed into *branch->p to fill that gap.
728 * If allocation fails we free all blocks we've allocated (and forget
729 * their buffer_heads) and return the error value the from failed
730 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
731 * as described above and return 0.
733 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
734 ext4_lblk_t iblock
, int indirect_blks
,
735 int *blks
, ext4_fsblk_t goal
,
736 ext4_lblk_t
*offsets
, Indirect
*branch
)
738 int blocksize
= inode
->i_sb
->s_blocksize
;
741 struct buffer_head
*bh
;
743 ext4_fsblk_t new_blocks
[4];
744 ext4_fsblk_t current_block
;
746 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
747 *blks
, new_blocks
, &err
);
751 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
753 * metadata blocks and data blocks are allocated.
755 for (n
= 1; n
<= indirect_blks
; n
++) {
757 * Get buffer_head for parent block, zero it out
758 * and set the pointer to new one, then send
761 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
764 BUFFER_TRACE(bh
, "call get_create_access");
765 err
= ext4_journal_get_create_access(handle
, bh
);
772 memset(bh
->b_data
, 0, blocksize
);
773 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
774 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
775 *branch
[n
].p
= branch
[n
].key
;
776 if (n
== indirect_blks
) {
777 current_block
= new_blocks
[n
];
779 * End of chain, update the last new metablock of
780 * the chain to point to the new allocated
781 * data blocks numbers
783 for (i
=1; i
< num
; i
++)
784 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
786 BUFFER_TRACE(bh
, "marking uptodate");
787 set_buffer_uptodate(bh
);
790 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
791 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
798 /* Allocation failed, free what we already allocated */
799 for (i
= 1; i
<= n
; i
++) {
800 BUFFER_TRACE(branch
[i
].bh
, "call jbd2_journal_forget");
801 ext4_journal_forget(handle
, branch
[i
].bh
);
803 for (i
= 0; i
< indirect_blks
; i
++)
804 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
806 ext4_free_blocks(handle
, inode
, new_blocks
[i
], num
, 0);
812 * ext4_splice_branch - splice the allocated branch onto inode.
814 * @block: (logical) number of block we are adding
815 * @chain: chain of indirect blocks (with a missing link - see
817 * @where: location of missing link
818 * @num: number of indirect blocks we are adding
819 * @blks: number of direct blocks we are adding
821 * This function fills the missing link and does all housekeeping needed in
822 * inode (->i_blocks, etc.). In case of success we end up with the full
823 * chain to new block and return 0.
825 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
826 ext4_lblk_t block
, Indirect
*where
, int num
, int blks
)
830 ext4_fsblk_t current_block
;
833 * If we're splicing into a [td]indirect block (as opposed to the
834 * inode) then we need to get write access to the [td]indirect block
838 BUFFER_TRACE(where
->bh
, "get_write_access");
839 err
= ext4_journal_get_write_access(handle
, where
->bh
);
845 *where
->p
= where
->key
;
848 * Update the host buffer_head or inode to point to more just allocated
849 * direct blocks blocks
851 if (num
== 0 && blks
> 1) {
852 current_block
= le32_to_cpu(where
->key
) + 1;
853 for (i
= 1; i
< blks
; i
++)
854 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
857 /* We are done with atomic stuff, now do the rest of housekeeping */
859 inode
->i_ctime
= ext4_current_time(inode
);
860 ext4_mark_inode_dirty(handle
, inode
);
862 /* had we spliced it onto indirect block? */
865 * If we spliced it onto an indirect block, we haven't
866 * altered the inode. Note however that if it is being spliced
867 * onto an indirect block at the very end of the file (the
868 * file is growing) then we *will* alter the inode to reflect
869 * the new i_size. But that is not done here - it is done in
870 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
872 jbd_debug(5, "splicing indirect only\n");
873 BUFFER_TRACE(where
->bh
, "call ext4_handle_dirty_metadata");
874 err
= ext4_handle_dirty_metadata(handle
, inode
, where
->bh
);
879 * OK, we spliced it into the inode itself on a direct block.
880 * Inode was dirtied above.
882 jbd_debug(5, "splicing direct\n");
887 for (i
= 1; i
<= num
; i
++) {
888 BUFFER_TRACE(where
[i
].bh
, "call jbd2_journal_forget");
889 ext4_journal_forget(handle
, where
[i
].bh
);
890 ext4_free_blocks(handle
, inode
,
891 le32_to_cpu(where
[i
-1].key
), 1, 0);
893 ext4_free_blocks(handle
, inode
, le32_to_cpu(where
[num
].key
), blks
, 0);
899 * The ext4_ind_get_blocks() function handles non-extents inodes
900 * (i.e., using the traditional indirect/double-indirect i_blocks
901 * scheme) for ext4_get_blocks().
903 * Allocation strategy is simple: if we have to allocate something, we will
904 * have to go the whole way to leaf. So let's do it before attaching anything
905 * to tree, set linkage between the newborn blocks, write them if sync is
906 * required, recheck the path, free and repeat if check fails, otherwise
907 * set the last missing link (that will protect us from any truncate-generated
908 * removals - all blocks on the path are immune now) and possibly force the
909 * write on the parent block.
910 * That has a nice additional property: no special recovery from the failed
911 * allocations is needed - we simply release blocks and do not touch anything
912 * reachable from inode.
914 * `handle' can be NULL if create == 0.
916 * return > 0, # of blocks mapped or allocated.
917 * return = 0, if plain lookup failed.
918 * return < 0, error case.
920 * The ext4_ind_get_blocks() function should be called with
921 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
922 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
923 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
926 static int ext4_ind_get_blocks(handle_t
*handle
, struct inode
*inode
,
927 ext4_lblk_t iblock
, unsigned int maxblocks
,
928 struct buffer_head
*bh_result
,
932 ext4_lblk_t offsets
[4];
937 int blocks_to_boundary
= 0;
940 ext4_fsblk_t first_block
= 0;
942 J_ASSERT(!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
));
943 J_ASSERT(handle
!= NULL
|| (flags
& EXT4_GET_BLOCKS_CREATE
) == 0);
944 depth
= ext4_block_to_path(inode
, iblock
, offsets
,
945 &blocks_to_boundary
);
950 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
952 /* Simplest case - block found, no allocation needed */
954 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
955 clear_buffer_new(bh_result
);
958 while (count
< maxblocks
&& count
<= blocks_to_boundary
) {
961 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
963 if (blk
== first_block
+ count
)
971 /* Next simple case - plain lookup or failed read of indirect block */
972 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0 || err
== -EIO
)
976 * Okay, we need to do block allocation.
978 goal
= ext4_find_goal(inode
, iblock
, partial
);
980 /* the number of blocks need to allocate for [d,t]indirect blocks */
981 indirect_blks
= (chain
+ depth
) - partial
- 1;
984 * Next look up the indirect map to count the totoal number of
985 * direct blocks to allocate for this branch.
987 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
988 maxblocks
, blocks_to_boundary
);
990 * Block out ext4_truncate while we alter the tree
992 err
= ext4_alloc_branch(handle
, inode
, iblock
, indirect_blks
,
994 offsets
+ (partial
- chain
), partial
);
997 * The ext4_splice_branch call will free and forget any buffers
998 * on the new chain if there is a failure, but that risks using
999 * up transaction credits, especially for bitmaps where the
1000 * credits cannot be returned. Can we handle this somehow? We
1001 * may need to return -EAGAIN upwards in the worst case. --sct
1004 err
= ext4_splice_branch(handle
, inode
, iblock
,
1005 partial
, indirect_blks
, count
);
1009 set_buffer_new(bh_result
);
1011 map_bh(bh_result
, inode
->i_sb
, le32_to_cpu(chain
[depth
-1].key
));
1012 if (count
> blocks_to_boundary
)
1013 set_buffer_boundary(bh_result
);
1015 /* Clean up and exit */
1016 partial
= chain
+ depth
- 1; /* the whole chain */
1018 while (partial
> chain
) {
1019 BUFFER_TRACE(partial
->bh
, "call brelse");
1020 brelse(partial
->bh
);
1023 BUFFER_TRACE(bh_result
, "returned");
1028 qsize_t
ext4_get_reserved_space(struct inode
*inode
)
1030 unsigned long long total
;
1032 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1033 total
= EXT4_I(inode
)->i_reserved_data_blocks
+
1034 EXT4_I(inode
)->i_reserved_meta_blocks
;
1035 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1040 * Calculate the number of metadata blocks need to reserve
1041 * to allocate @blocks for non extent file based file
1043 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
, int blocks
)
1045 int icap
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
1046 int ind_blks
, dind_blks
, tind_blks
;
1048 /* number of new indirect blocks needed */
1049 ind_blks
= (blocks
+ icap
- 1) / icap
;
1051 dind_blks
= (ind_blks
+ icap
- 1) / icap
;
1055 return ind_blks
+ dind_blks
+ tind_blks
;
1059 * Calculate the number of metadata blocks need to reserve
1060 * to allocate given number of blocks
1062 static int ext4_calc_metadata_amount(struct inode
*inode
, int blocks
)
1067 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
1068 return ext4_ext_calc_metadata_amount(inode
, blocks
);
1070 return ext4_indirect_calc_metadata_amount(inode
, blocks
);
1073 static void ext4_da_update_reserve_space(struct inode
*inode
, int used
)
1075 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1076 int total
, mdb
, mdb_free
;
1078 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1079 /* recalculate the number of metablocks still need to be reserved */
1080 total
= EXT4_I(inode
)->i_reserved_data_blocks
- used
;
1081 mdb
= ext4_calc_metadata_amount(inode
, total
);
1083 /* figure out how many metablocks to release */
1084 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1085 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1088 /* Account for allocated meta_blocks */
1089 mdb_free
-= EXT4_I(inode
)->i_allocated_meta_blocks
;
1091 /* update fs dirty blocks counter */
1092 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1093 EXT4_I(inode
)->i_allocated_meta_blocks
= 0;
1094 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1097 /* update per-inode reservations */
1098 BUG_ON(used
> EXT4_I(inode
)->i_reserved_data_blocks
);
1099 EXT4_I(inode
)->i_reserved_data_blocks
-= used
;
1100 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1103 * free those over-booking quota for metadata blocks
1106 vfs_dq_release_reservation_block(inode
, mdb_free
);
1109 * If we have done all the pending block allocations and if
1110 * there aren't any writers on the inode, we can discard the
1111 * inode's preallocations.
1113 if (!total
&& (atomic_read(&inode
->i_writecount
) == 0))
1114 ext4_discard_preallocations(inode
);
1117 static int check_block_validity(struct inode
*inode
, sector_t logical
,
1118 sector_t phys
, int len
)
1120 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), phys
, len
)) {
1121 ext4_error(inode
->i_sb
, "check_block_validity",
1122 "inode #%lu logical block %llu mapped to %llu "
1123 "(size %d)", inode
->i_ino
,
1124 (unsigned long long) logical
,
1125 (unsigned long long) phys
, len
);
1133 * The ext4_get_blocks() function tries to look up the requested blocks,
1134 * and returns if the blocks are already mapped.
1136 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1137 * and store the allocated blocks in the result buffer head and mark it
1140 * If file type is extents based, it will call ext4_ext_get_blocks(),
1141 * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
1144 * On success, it returns the number of blocks being mapped or allocate.
1145 * if create==0 and the blocks are pre-allocated and uninitialized block,
1146 * the result buffer head is unmapped. If the create ==1, it will make sure
1147 * the buffer head is mapped.
1149 * It returns 0 if plain look up failed (blocks have not been allocated), in
1150 * that casem, buffer head is unmapped
1152 * It returns the error in case of allocation failure.
1154 int ext4_get_blocks(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1155 unsigned int max_blocks
, struct buffer_head
*bh
,
1160 clear_buffer_mapped(bh
);
1161 clear_buffer_unwritten(bh
);
1164 * Try to see if we can get the block without requesting a new
1165 * file system block.
1167 down_read((&EXT4_I(inode
)->i_data_sem
));
1168 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1169 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1172 retval
= ext4_ind_get_blocks(handle
, inode
, block
, max_blocks
,
1175 up_read((&EXT4_I(inode
)->i_data_sem
));
1177 if (retval
> 0 && buffer_mapped(bh
)) {
1178 int ret
= check_block_validity(inode
, block
,
1179 bh
->b_blocknr
, retval
);
1184 /* If it is only a block(s) look up */
1185 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
1189 * Returns if the blocks have already allocated
1191 * Note that if blocks have been preallocated
1192 * ext4_ext_get_block() returns th create = 0
1193 * with buffer head unmapped.
1195 if (retval
> 0 && buffer_mapped(bh
))
1199 * When we call get_blocks without the create flag, the
1200 * BH_Unwritten flag could have gotten set if the blocks
1201 * requested were part of a uninitialized extent. We need to
1202 * clear this flag now that we are committed to convert all or
1203 * part of the uninitialized extent to be an initialized
1204 * extent. This is because we need to avoid the combination
1205 * of BH_Unwritten and BH_Mapped flags being simultaneously
1206 * set on the buffer_head.
1208 clear_buffer_unwritten(bh
);
1211 * New blocks allocate and/or writing to uninitialized extent
1212 * will possibly result in updating i_data, so we take
1213 * the write lock of i_data_sem, and call get_blocks()
1214 * with create == 1 flag.
1216 down_write((&EXT4_I(inode
)->i_data_sem
));
1219 * if the caller is from delayed allocation writeout path
1220 * we have already reserved fs blocks for allocation
1221 * let the underlying get_block() function know to
1222 * avoid double accounting
1224 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1225 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1227 * We need to check for EXT4 here because migrate
1228 * could have changed the inode type in between
1230 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1231 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1234 retval
= ext4_ind_get_blocks(handle
, inode
, block
,
1235 max_blocks
, bh
, flags
);
1237 if (retval
> 0 && buffer_new(bh
)) {
1239 * We allocated new blocks which will result in
1240 * i_data's format changing. Force the migrate
1241 * to fail by clearing migrate flags
1243 EXT4_I(inode
)->i_flags
= EXT4_I(inode
)->i_flags
&
1248 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1249 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1252 * Update reserved blocks/metadata blocks after successful
1253 * block allocation which had been deferred till now.
1255 if ((retval
> 0) && (flags
& EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
))
1256 ext4_da_update_reserve_space(inode
, retval
);
1258 up_write((&EXT4_I(inode
)->i_data_sem
));
1259 if (retval
> 0 && buffer_mapped(bh
)) {
1260 int ret
= check_block_validity(inode
, block
,
1261 bh
->b_blocknr
, retval
);
1268 /* Maximum number of blocks we map for direct IO at once. */
1269 #define DIO_MAX_BLOCKS 4096
1271 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1272 struct buffer_head
*bh_result
, int create
)
1274 handle_t
*handle
= ext4_journal_current_handle();
1275 int ret
= 0, started
= 0;
1276 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1279 if (create
&& !handle
) {
1280 /* Direct IO write... */
1281 if (max_blocks
> DIO_MAX_BLOCKS
)
1282 max_blocks
= DIO_MAX_BLOCKS
;
1283 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1284 handle
= ext4_journal_start(inode
, dio_credits
);
1285 if (IS_ERR(handle
)) {
1286 ret
= PTR_ERR(handle
);
1292 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
1293 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1295 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1299 ext4_journal_stop(handle
);
1305 * `handle' can be NULL if create is zero
1307 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1308 ext4_lblk_t block
, int create
, int *errp
)
1310 struct buffer_head dummy
;
1314 J_ASSERT(handle
!= NULL
|| create
== 0);
1317 dummy
.b_blocknr
= -1000;
1318 buffer_trace_init(&dummy
.b_history
);
1320 flags
|= EXT4_GET_BLOCKS_CREATE
;
1321 err
= ext4_get_blocks(handle
, inode
, block
, 1, &dummy
, flags
);
1323 * ext4_get_blocks() returns number of blocks mapped. 0 in
1332 if (!err
&& buffer_mapped(&dummy
)) {
1333 struct buffer_head
*bh
;
1334 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1339 if (buffer_new(&dummy
)) {
1340 J_ASSERT(create
!= 0);
1341 J_ASSERT(handle
!= NULL
);
1344 * Now that we do not always journal data, we should
1345 * keep in mind whether this should always journal the
1346 * new buffer as metadata. For now, regular file
1347 * writes use ext4_get_block instead, so it's not a
1351 BUFFER_TRACE(bh
, "call get_create_access");
1352 fatal
= ext4_journal_get_create_access(handle
, bh
);
1353 if (!fatal
&& !buffer_uptodate(bh
)) {
1354 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1355 set_buffer_uptodate(bh
);
1358 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1359 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1363 BUFFER_TRACE(bh
, "not a new buffer");
1376 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1377 ext4_lblk_t block
, int create
, int *err
)
1379 struct buffer_head
*bh
;
1381 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1384 if (buffer_uptodate(bh
))
1386 ll_rw_block(READ_META
, 1, &bh
);
1388 if (buffer_uptodate(bh
))
1395 static int walk_page_buffers(handle_t
*handle
,
1396 struct buffer_head
*head
,
1400 int (*fn
)(handle_t
*handle
,
1401 struct buffer_head
*bh
))
1403 struct buffer_head
*bh
;
1404 unsigned block_start
, block_end
;
1405 unsigned blocksize
= head
->b_size
;
1407 struct buffer_head
*next
;
1409 for (bh
= head
, block_start
= 0;
1410 ret
== 0 && (bh
!= head
|| !block_start
);
1411 block_start
= block_end
, bh
= next
)
1413 next
= bh
->b_this_page
;
1414 block_end
= block_start
+ blocksize
;
1415 if (block_end
<= from
|| block_start
>= to
) {
1416 if (partial
&& !buffer_uptodate(bh
))
1420 err
= (*fn
)(handle
, bh
);
1428 * To preserve ordering, it is essential that the hole instantiation and
1429 * the data write be encapsulated in a single transaction. We cannot
1430 * close off a transaction and start a new one between the ext4_get_block()
1431 * and the commit_write(). So doing the jbd2_journal_start at the start of
1432 * prepare_write() is the right place.
1434 * Also, this function can nest inside ext4_writepage() ->
1435 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1436 * has generated enough buffer credits to do the whole page. So we won't
1437 * block on the journal in that case, which is good, because the caller may
1440 * By accident, ext4 can be reentered when a transaction is open via
1441 * quota file writes. If we were to commit the transaction while thus
1442 * reentered, there can be a deadlock - we would be holding a quota
1443 * lock, and the commit would never complete if another thread had a
1444 * transaction open and was blocking on the quota lock - a ranking
1447 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1448 * will _not_ run commit under these circumstances because handle->h_ref
1449 * is elevated. We'll still have enough credits for the tiny quotafile
1452 static int do_journal_get_write_access(handle_t
*handle
,
1453 struct buffer_head
*bh
)
1455 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1457 return ext4_journal_get_write_access(handle
, bh
);
1460 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1461 loff_t pos
, unsigned len
, unsigned flags
,
1462 struct page
**pagep
, void **fsdata
)
1464 struct inode
*inode
= mapping
->host
;
1465 int ret
, needed_blocks
;
1472 trace_ext4_write_begin(inode
, pos
, len
, flags
);
1474 * Reserve one block more for addition to orphan list in case
1475 * we allocate blocks but write fails for some reason
1477 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
1478 index
= pos
>> PAGE_CACHE_SHIFT
;
1479 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1483 handle
= ext4_journal_start(inode
, needed_blocks
);
1484 if (IS_ERR(handle
)) {
1485 ret
= PTR_ERR(handle
);
1489 /* We cannot recurse into the filesystem as the transaction is already
1491 flags
|= AOP_FLAG_NOFS
;
1493 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1495 ext4_journal_stop(handle
);
1501 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1504 if (!ret
&& ext4_should_journal_data(inode
)) {
1505 ret
= walk_page_buffers(handle
, page_buffers(page
),
1506 from
, to
, NULL
, do_journal_get_write_access
);
1511 page_cache_release(page
);
1513 * block_write_begin may have instantiated a few blocks
1514 * outside i_size. Trim these off again. Don't need
1515 * i_size_read because we hold i_mutex.
1517 * Add inode to orphan list in case we crash before
1520 if (pos
+ len
> inode
->i_size
)
1521 ext4_orphan_add(handle
, inode
);
1523 ext4_journal_stop(handle
);
1524 if (pos
+ len
> inode
->i_size
) {
1525 vmtruncate(inode
, inode
->i_size
);
1527 * If vmtruncate failed early the inode might
1528 * still be on the orphan list; we need to
1529 * make sure the inode is removed from the
1530 * orphan list in that case.
1533 ext4_orphan_del(NULL
, inode
);
1537 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1543 /* For write_end() in data=journal mode */
1544 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1546 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1548 set_buffer_uptodate(bh
);
1549 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1552 static int ext4_generic_write_end(struct file
*file
,
1553 struct address_space
*mapping
,
1554 loff_t pos
, unsigned len
, unsigned copied
,
1555 struct page
*page
, void *fsdata
)
1557 int i_size_changed
= 0;
1558 struct inode
*inode
= mapping
->host
;
1559 handle_t
*handle
= ext4_journal_current_handle();
1561 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1564 * No need to use i_size_read() here, the i_size
1565 * cannot change under us because we hold i_mutex.
1567 * But it's important to update i_size while still holding page lock:
1568 * page writeout could otherwise come in and zero beyond i_size.
1570 if (pos
+ copied
> inode
->i_size
) {
1571 i_size_write(inode
, pos
+ copied
);
1575 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
1576 /* We need to mark inode dirty even if
1577 * new_i_size is less that inode->i_size
1578 * bu greater than i_disksize.(hint delalloc)
1580 ext4_update_i_disksize(inode
, (pos
+ copied
));
1584 page_cache_release(page
);
1587 * Don't mark the inode dirty under page lock. First, it unnecessarily
1588 * makes the holding time of page lock longer. Second, it forces lock
1589 * ordering of page lock and transaction start for journaling
1593 ext4_mark_inode_dirty(handle
, inode
);
1599 * We need to pick up the new inode size which generic_commit_write gave us
1600 * `file' can be NULL - eg, when called from page_symlink().
1602 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1603 * buffers are managed internally.
1605 static int ext4_ordered_write_end(struct file
*file
,
1606 struct address_space
*mapping
,
1607 loff_t pos
, unsigned len
, unsigned copied
,
1608 struct page
*page
, void *fsdata
)
1610 handle_t
*handle
= ext4_journal_current_handle();
1611 struct inode
*inode
= mapping
->host
;
1614 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
1615 ret
= ext4_jbd2_file_inode(handle
, inode
);
1618 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1621 if (pos
+ len
> inode
->i_size
)
1622 /* if we have allocated more blocks and copied
1623 * less. We will have blocks allocated outside
1624 * inode->i_size. So truncate them
1626 ext4_orphan_add(handle
, inode
);
1630 ret2
= ext4_journal_stop(handle
);
1634 if (pos
+ len
> inode
->i_size
) {
1635 vmtruncate(inode
, inode
->i_size
);
1637 * If vmtruncate failed early the inode might still be
1638 * on the orphan list; we need to make sure the inode
1639 * is removed from the orphan list in that case.
1642 ext4_orphan_del(NULL
, inode
);
1646 return ret
? ret
: copied
;
1649 static int ext4_writeback_write_end(struct file
*file
,
1650 struct address_space
*mapping
,
1651 loff_t pos
, unsigned len
, unsigned copied
,
1652 struct page
*page
, void *fsdata
)
1654 handle_t
*handle
= ext4_journal_current_handle();
1655 struct inode
*inode
= mapping
->host
;
1658 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1659 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1662 if (pos
+ len
> inode
->i_size
)
1663 /* if we have allocated more blocks and copied
1664 * less. We will have blocks allocated outside
1665 * inode->i_size. So truncate them
1667 ext4_orphan_add(handle
, inode
);
1672 ret2
= ext4_journal_stop(handle
);
1676 if (pos
+ len
> inode
->i_size
) {
1677 vmtruncate(inode
, inode
->i_size
);
1679 * If vmtruncate failed early the inode might still be
1680 * on the orphan list; we need to make sure the inode
1681 * is removed from the orphan list in that case.
1684 ext4_orphan_del(NULL
, inode
);
1687 return ret
? ret
: copied
;
1690 static int ext4_journalled_write_end(struct file
*file
,
1691 struct address_space
*mapping
,
1692 loff_t pos
, unsigned len
, unsigned copied
,
1693 struct page
*page
, void *fsdata
)
1695 handle_t
*handle
= ext4_journal_current_handle();
1696 struct inode
*inode
= mapping
->host
;
1702 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1703 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1707 if (!PageUptodate(page
))
1709 page_zero_new_buffers(page
, from
+copied
, to
);
1712 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1713 to
, &partial
, write_end_fn
);
1715 SetPageUptodate(page
);
1716 new_i_size
= pos
+ copied
;
1717 if (new_i_size
> inode
->i_size
)
1718 i_size_write(inode
, pos
+copied
);
1719 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1720 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1721 ext4_update_i_disksize(inode
, new_i_size
);
1722 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1728 page_cache_release(page
);
1729 if (pos
+ len
> inode
->i_size
)
1730 /* if we have allocated more blocks and copied
1731 * less. We will have blocks allocated outside
1732 * inode->i_size. So truncate them
1734 ext4_orphan_add(handle
, inode
);
1736 ret2
= ext4_journal_stop(handle
);
1739 if (pos
+ len
> inode
->i_size
) {
1740 vmtruncate(inode
, inode
->i_size
);
1742 * If vmtruncate failed early the inode might still be
1743 * on the orphan list; we need to make sure the inode
1744 * is removed from the orphan list in that case.
1747 ext4_orphan_del(NULL
, inode
);
1750 return ret
? ret
: copied
;
1753 static int ext4_da_reserve_space(struct inode
*inode
, int nrblocks
)
1756 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1757 unsigned long md_needed
, mdblocks
, total
= 0;
1760 * recalculate the amount of metadata blocks to reserve
1761 * in order to allocate nrblocks
1762 * worse case is one extent per block
1765 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1766 total
= EXT4_I(inode
)->i_reserved_data_blocks
+ nrblocks
;
1767 mdblocks
= ext4_calc_metadata_amount(inode
, total
);
1768 BUG_ON(mdblocks
< EXT4_I(inode
)->i_reserved_meta_blocks
);
1770 md_needed
= mdblocks
- EXT4_I(inode
)->i_reserved_meta_blocks
;
1771 total
= md_needed
+ nrblocks
;
1774 * Make quota reservation here to prevent quota overflow
1775 * later. Real quota accounting is done at pages writeout
1778 if (vfs_dq_reserve_block(inode
, total
)) {
1779 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1783 if (ext4_claim_free_blocks(sbi
, total
)) {
1784 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1785 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1789 vfs_dq_release_reservation_block(inode
, total
);
1792 EXT4_I(inode
)->i_reserved_data_blocks
+= nrblocks
;
1793 EXT4_I(inode
)->i_reserved_meta_blocks
= mdblocks
;
1795 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1796 return 0; /* success */
1799 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1801 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1802 int total
, mdb
, mdb_free
, release
;
1805 return; /* Nothing to release, exit */
1807 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1809 if (!EXT4_I(inode
)->i_reserved_data_blocks
) {
1811 * if there is no reserved blocks, but we try to free some
1812 * then the counter is messed up somewhere.
1813 * but since this function is called from invalidate
1814 * page, it's harmless to return without any action
1816 printk(KERN_INFO
"ext4 delalloc try to release %d reserved "
1817 "blocks for inode %lu, but there is no reserved "
1818 "data blocks\n", to_free
, inode
->i_ino
);
1819 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1823 /* recalculate the number of metablocks still need to be reserved */
1824 total
= EXT4_I(inode
)->i_reserved_data_blocks
- to_free
;
1825 mdb
= ext4_calc_metadata_amount(inode
, total
);
1827 /* figure out how many metablocks to release */
1828 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1829 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1831 release
= to_free
+ mdb_free
;
1833 /* update fs dirty blocks counter for truncate case */
1834 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, release
);
1836 /* update per-inode reservations */
1837 BUG_ON(to_free
> EXT4_I(inode
)->i_reserved_data_blocks
);
1838 EXT4_I(inode
)->i_reserved_data_blocks
-= to_free
;
1840 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1841 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1842 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1844 vfs_dq_release_reservation_block(inode
, release
);
1847 static void ext4_da_page_release_reservation(struct page
*page
,
1848 unsigned long offset
)
1851 struct buffer_head
*head
, *bh
;
1852 unsigned int curr_off
= 0;
1854 head
= page_buffers(page
);
1857 unsigned int next_off
= curr_off
+ bh
->b_size
;
1859 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1861 clear_buffer_delay(bh
);
1863 curr_off
= next_off
;
1864 } while ((bh
= bh
->b_this_page
) != head
);
1865 ext4_da_release_space(page
->mapping
->host
, to_release
);
1869 * Delayed allocation stuff
1872 struct mpage_da_data
{
1873 struct inode
*inode
;
1874 sector_t b_blocknr
; /* start block number of extent */
1875 size_t b_size
; /* size of extent */
1876 unsigned long b_state
; /* state of the extent */
1877 unsigned long first_page
, next_page
; /* extent of pages */
1878 struct writeback_control
*wbc
;
1885 * mpage_da_submit_io - walks through extent of pages and try to write
1886 * them with writepage() call back
1888 * @mpd->inode: inode
1889 * @mpd->first_page: first page of the extent
1890 * @mpd->next_page: page after the last page of the extent
1892 * By the time mpage_da_submit_io() is called we expect all blocks
1893 * to be allocated. this may be wrong if allocation failed.
1895 * As pages are already locked by write_cache_pages(), we can't use it
1897 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1900 struct pagevec pvec
;
1901 unsigned long index
, end
;
1902 int ret
= 0, err
, nr_pages
, i
;
1903 struct inode
*inode
= mpd
->inode
;
1904 struct address_space
*mapping
= inode
->i_mapping
;
1906 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1908 * We need to start from the first_page to the next_page - 1
1909 * to make sure we also write the mapped dirty buffer_heads.
1910 * If we look at mpd->b_blocknr we would only be looking
1911 * at the currently mapped buffer_heads.
1913 index
= mpd
->first_page
;
1914 end
= mpd
->next_page
- 1;
1916 pagevec_init(&pvec
, 0);
1917 while (index
<= end
) {
1918 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1921 for (i
= 0; i
< nr_pages
; i
++) {
1922 struct page
*page
= pvec
.pages
[i
];
1924 index
= page
->index
;
1929 BUG_ON(!PageLocked(page
));
1930 BUG_ON(PageWriteback(page
));
1932 pages_skipped
= mpd
->wbc
->pages_skipped
;
1933 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
1934 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
1936 * have successfully written the page
1937 * without skipping the same
1939 mpd
->pages_written
++;
1941 * In error case, we have to continue because
1942 * remaining pages are still locked
1943 * XXX: unlock and re-dirty them?
1948 pagevec_release(&pvec
);
1954 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
1956 * @mpd->inode - inode to walk through
1957 * @exbh->b_blocknr - first block on a disk
1958 * @exbh->b_size - amount of space in bytes
1959 * @logical - first logical block to start assignment with
1961 * the function goes through all passed space and put actual disk
1962 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
1964 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
1965 struct buffer_head
*exbh
)
1967 struct inode
*inode
= mpd
->inode
;
1968 struct address_space
*mapping
= inode
->i_mapping
;
1969 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
1970 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
1971 struct buffer_head
*head
, *bh
;
1973 struct pagevec pvec
;
1976 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1977 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1978 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1980 pagevec_init(&pvec
, 0);
1982 while (index
<= end
) {
1983 /* XXX: optimize tail */
1984 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1987 for (i
= 0; i
< nr_pages
; i
++) {
1988 struct page
*page
= pvec
.pages
[i
];
1990 index
= page
->index
;
1995 BUG_ON(!PageLocked(page
));
1996 BUG_ON(PageWriteback(page
));
1997 BUG_ON(!page_has_buffers(page
));
1999 bh
= page_buffers(page
);
2002 /* skip blocks out of the range */
2004 if (cur_logical
>= logical
)
2007 } while ((bh
= bh
->b_this_page
) != head
);
2010 if (cur_logical
>= logical
+ blocks
)
2013 if (buffer_delay(bh
) ||
2014 buffer_unwritten(bh
)) {
2016 BUG_ON(bh
->b_bdev
!= inode
->i_sb
->s_bdev
);
2018 if (buffer_delay(bh
)) {
2019 clear_buffer_delay(bh
);
2020 bh
->b_blocknr
= pblock
;
2023 * unwritten already should have
2024 * blocknr assigned. Verify that
2026 clear_buffer_unwritten(bh
);
2027 BUG_ON(bh
->b_blocknr
!= pblock
);
2030 } else if (buffer_mapped(bh
))
2031 BUG_ON(bh
->b_blocknr
!= pblock
);
2035 } while ((bh
= bh
->b_this_page
) != head
);
2037 pagevec_release(&pvec
);
2043 * __unmap_underlying_blocks - just a helper function to unmap
2044 * set of blocks described by @bh
2046 static inline void __unmap_underlying_blocks(struct inode
*inode
,
2047 struct buffer_head
*bh
)
2049 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
2052 blocks
= bh
->b_size
>> inode
->i_blkbits
;
2053 for (i
= 0; i
< blocks
; i
++)
2054 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
2057 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
2058 sector_t logical
, long blk_cnt
)
2062 struct pagevec pvec
;
2063 struct inode
*inode
= mpd
->inode
;
2064 struct address_space
*mapping
= inode
->i_mapping
;
2066 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2067 end
= (logical
+ blk_cnt
- 1) >>
2068 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2069 while (index
<= end
) {
2070 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2073 for (i
= 0; i
< nr_pages
; i
++) {
2074 struct page
*page
= pvec
.pages
[i
];
2075 index
= page
->index
;
2080 BUG_ON(!PageLocked(page
));
2081 BUG_ON(PageWriteback(page
));
2082 block_invalidatepage(page
, 0);
2083 ClearPageUptodate(page
);
2090 static void ext4_print_free_blocks(struct inode
*inode
)
2092 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2093 printk(KERN_EMERG
"Total free blocks count %lld\n",
2094 ext4_count_free_blocks(inode
->i_sb
));
2095 printk(KERN_EMERG
"Free/Dirty block details\n");
2096 printk(KERN_EMERG
"free_blocks=%lld\n",
2097 (long long)percpu_counter_sum(&sbi
->s_freeblocks_counter
));
2098 printk(KERN_EMERG
"dirty_blocks=%lld\n",
2099 (long long)percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
2100 printk(KERN_EMERG
"Block reservation details\n");
2101 printk(KERN_EMERG
"i_reserved_data_blocks=%u\n",
2102 EXT4_I(inode
)->i_reserved_data_blocks
);
2103 printk(KERN_EMERG
"i_reserved_meta_blocks=%u\n",
2104 EXT4_I(inode
)->i_reserved_meta_blocks
);
2109 * mpage_da_map_blocks - go through given space
2111 * @mpd - bh describing space
2113 * The function skips space we know is already mapped to disk blocks.
2116 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
2118 int err
, blks
, get_blocks_flags
;
2119 struct buffer_head
new;
2120 sector_t next
= mpd
->b_blocknr
;
2121 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2122 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
2123 handle_t
*handle
= NULL
;
2126 * We consider only non-mapped and non-allocated blocks
2128 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2129 !(mpd
->b_state
& (1 << BH_Delay
)) &&
2130 !(mpd
->b_state
& (1 << BH_Unwritten
)))
2134 * If we didn't accumulate anything to write simply return
2139 handle
= ext4_journal_current_handle();
2143 * Call ext4_get_blocks() to allocate any delayed allocation
2144 * blocks, or to convert an uninitialized extent to be
2145 * initialized (in the case where we have written into
2146 * one or more preallocated blocks).
2148 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2149 * indicate that we are on the delayed allocation path. This
2150 * affects functions in many different parts of the allocation
2151 * call path. This flag exists primarily because we don't
2152 * want to change *many* call functions, so ext4_get_blocks()
2153 * will set the magic i_delalloc_reserved_flag once the
2154 * inode's allocation semaphore is taken.
2156 * If the blocks in questions were delalloc blocks, set
2157 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2158 * variables are updated after the blocks have been allocated.
2161 get_blocks_flags
= (EXT4_GET_BLOCKS_CREATE
|
2162 EXT4_GET_BLOCKS_DELALLOC_RESERVE
);
2163 if (mpd
->b_state
& (1 << BH_Delay
))
2164 get_blocks_flags
|= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
;
2165 blks
= ext4_get_blocks(handle
, mpd
->inode
, next
, max_blocks
,
2166 &new, get_blocks_flags
);
2170 * If get block returns with error we simply
2171 * return. Later writepage will redirty the page and
2172 * writepages will find the dirty page again
2177 if (err
== -ENOSPC
&&
2178 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
2184 * get block failure will cause us to loop in
2185 * writepages, because a_ops->writepage won't be able
2186 * to make progress. The page will be redirtied by
2187 * writepage and writepages will again try to write
2190 printk(KERN_EMERG
"%s block allocation failed for inode %lu "
2191 "at logical offset %llu with max blocks "
2192 "%zd with error %d\n",
2193 __func__
, mpd
->inode
->i_ino
,
2194 (unsigned long long)next
,
2195 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2196 printk(KERN_EMERG
"This should not happen.!! "
2197 "Data will be lost\n");
2198 if (err
== -ENOSPC
) {
2199 ext4_print_free_blocks(mpd
->inode
);
2201 /* invalidate all the pages */
2202 ext4_da_block_invalidatepages(mpd
, next
,
2203 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2208 new.b_size
= (blks
<< mpd
->inode
->i_blkbits
);
2210 if (buffer_new(&new))
2211 __unmap_underlying_blocks(mpd
->inode
, &new);
2214 * If blocks are delayed marked, we need to
2215 * put actual blocknr and drop delayed bit
2217 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2218 (mpd
->b_state
& (1 << BH_Unwritten
)))
2219 mpage_put_bnr_to_bhs(mpd
, next
, &new);
2221 if (ext4_should_order_data(mpd
->inode
)) {
2222 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
2228 * Update on-disk size along with block allocation.
2230 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
2231 if (disksize
> i_size_read(mpd
->inode
))
2232 disksize
= i_size_read(mpd
->inode
);
2233 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
2234 ext4_update_i_disksize(mpd
->inode
, disksize
);
2235 return ext4_mark_inode_dirty(handle
, mpd
->inode
);
2241 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2242 (1 << BH_Delay) | (1 << BH_Unwritten))
2245 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2247 * @mpd->lbh - extent of blocks
2248 * @logical - logical number of the block in the file
2249 * @bh - bh of the block (used to access block's state)
2251 * the function is used to collect contig. blocks in same state
2253 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2254 sector_t logical
, size_t b_size
,
2255 unsigned long b_state
)
2258 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2260 /* check if thereserved journal credits might overflow */
2261 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
2262 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2264 * With non-extent format we are limited by the journal
2265 * credit available. Total credit needed to insert
2266 * nrblocks contiguous blocks is dependent on the
2267 * nrblocks. So limit nrblocks.
2270 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2271 EXT4_MAX_TRANS_DATA
) {
2273 * Adding the new buffer_head would make it cross the
2274 * allowed limit for which we have journal credit
2275 * reserved. So limit the new bh->b_size
2277 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2278 mpd
->inode
->i_blkbits
;
2279 /* we will do mpage_da_submit_io in the next loop */
2283 * First block in the extent
2285 if (mpd
->b_size
== 0) {
2286 mpd
->b_blocknr
= logical
;
2287 mpd
->b_size
= b_size
;
2288 mpd
->b_state
= b_state
& BH_FLAGS
;
2292 next
= mpd
->b_blocknr
+ nrblocks
;
2294 * Can we merge the block to our big extent?
2296 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2297 mpd
->b_size
+= b_size
;
2303 * We couldn't merge the block to our extent, so we
2304 * need to flush current extent and start new one
2306 if (mpage_da_map_blocks(mpd
) == 0)
2307 mpage_da_submit_io(mpd
);
2312 static int ext4_bh_unmapped_or_delay(handle_t
*handle
, struct buffer_head
*bh
)
2315 * unmapped buffer is possible for holes.
2316 * delay buffer is possible with delayed allocation.
2317 * We also need to consider unwritten buffer as unmapped.
2319 return (!buffer_mapped(bh
) || buffer_delay(bh
) ||
2320 buffer_unwritten(bh
)) && buffer_dirty(bh
);
2324 * __mpage_da_writepage - finds extent of pages and blocks
2326 * @page: page to consider
2327 * @wbc: not used, we just follow rules
2330 * The function finds extents of pages and scan them for all blocks.
2332 static int __mpage_da_writepage(struct page
*page
,
2333 struct writeback_control
*wbc
, void *data
)
2335 struct mpage_da_data
*mpd
= data
;
2336 struct inode
*inode
= mpd
->inode
;
2337 struct buffer_head
*bh
, *head
;
2342 * Rest of the page in the page_vec
2343 * redirty then and skip then. We will
2344 * try to to write them again after
2345 * starting a new transaction
2347 redirty_page_for_writepage(wbc
, page
);
2349 return MPAGE_DA_EXTENT_TAIL
;
2352 * Can we merge this page to current extent?
2354 if (mpd
->next_page
!= page
->index
) {
2356 * Nope, we can't. So, we map non-allocated blocks
2357 * and start IO on them using writepage()
2359 if (mpd
->next_page
!= mpd
->first_page
) {
2360 if (mpage_da_map_blocks(mpd
) == 0)
2361 mpage_da_submit_io(mpd
);
2363 * skip rest of the page in the page_vec
2366 redirty_page_for_writepage(wbc
, page
);
2368 return MPAGE_DA_EXTENT_TAIL
;
2372 * Start next extent of pages ...
2374 mpd
->first_page
= page
->index
;
2384 mpd
->next_page
= page
->index
+ 1;
2385 logical
= (sector_t
) page
->index
<<
2386 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2388 if (!page_has_buffers(page
)) {
2389 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2390 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2392 return MPAGE_DA_EXTENT_TAIL
;
2395 * Page with regular buffer heads, just add all dirty ones
2397 head
= page_buffers(page
);
2400 BUG_ON(buffer_locked(bh
));
2402 * We need to try to allocate
2403 * unmapped blocks in the same page.
2404 * Otherwise we won't make progress
2405 * with the page in ext4_da_writepage
2407 if (ext4_bh_unmapped_or_delay(NULL
, bh
)) {
2408 mpage_add_bh_to_extent(mpd
, logical
,
2412 return MPAGE_DA_EXTENT_TAIL
;
2413 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2415 * mapped dirty buffer. We need to update
2416 * the b_state because we look at
2417 * b_state in mpage_da_map_blocks. We don't
2418 * update b_size because if we find an
2419 * unmapped buffer_head later we need to
2420 * use the b_state flag of that buffer_head.
2422 if (mpd
->b_size
== 0)
2423 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2426 } while ((bh
= bh
->b_this_page
) != head
);
2433 * This is a special get_blocks_t callback which is used by
2434 * ext4_da_write_begin(). It will either return mapped block or
2435 * reserve space for a single block.
2437 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2438 * We also have b_blocknr = -1 and b_bdev initialized properly
2440 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2441 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2442 * initialized properly.
2444 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2445 struct buffer_head
*bh_result
, int create
)
2448 sector_t invalid_block
= ~((sector_t
) 0xffff);
2450 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
2453 BUG_ON(create
== 0);
2454 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2457 * first, we need to know whether the block is allocated already
2458 * preallocated blocks are unmapped but should treated
2459 * the same as allocated blocks.
2461 ret
= ext4_get_blocks(NULL
, inode
, iblock
, 1, bh_result
, 0);
2462 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2463 /* the block isn't (pre)allocated yet, let's reserve space */
2465 * XXX: __block_prepare_write() unmaps passed block,
2468 ret
= ext4_da_reserve_space(inode
, 1);
2470 /* not enough space to reserve */
2473 map_bh(bh_result
, inode
->i_sb
, invalid_block
);
2474 set_buffer_new(bh_result
);
2475 set_buffer_delay(bh_result
);
2476 } else if (ret
> 0) {
2477 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2478 if (buffer_unwritten(bh_result
)) {
2479 /* A delayed write to unwritten bh should
2480 * be marked new and mapped. Mapped ensures
2481 * that we don't do get_block multiple times
2482 * when we write to the same offset and new
2483 * ensures that we do proper zero out for
2486 set_buffer_new(bh_result
);
2487 set_buffer_mapped(bh_result
);
2496 * This function is used as a standard get_block_t calback function
2497 * when there is no desire to allocate any blocks. It is used as a
2498 * callback function for block_prepare_write(), nobh_writepage(), and
2499 * block_write_full_page(). These functions should only try to map a
2500 * single block at a time.
2502 * Since this function doesn't do block allocations even if the caller
2503 * requests it by passing in create=1, it is critically important that
2504 * any caller checks to make sure that any buffer heads are returned
2505 * by this function are either all already mapped or marked for
2506 * delayed allocation before calling nobh_writepage() or
2507 * block_write_full_page(). Otherwise, b_blocknr could be left
2508 * unitialized, and the page write functions will be taken by
2511 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
2512 struct buffer_head
*bh_result
, int create
)
2515 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2517 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2520 * we don't want to do block allocation in writepage
2521 * so call get_block_wrap with create = 0
2523 ret
= ext4_get_blocks(NULL
, inode
, iblock
, max_blocks
, bh_result
, 0);
2524 BUG_ON(create
&& ret
== 0);
2526 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2533 * This function can get called via...
2534 * - ext4_da_writepages after taking page lock (have journal handle)
2535 * - journal_submit_inode_data_buffers (no journal handle)
2536 * - shrink_page_list via pdflush (no journal handle)
2537 * - grab_page_cache when doing write_begin (have journal handle)
2539 static int ext4_da_writepage(struct page
*page
,
2540 struct writeback_control
*wbc
)
2545 struct buffer_head
*page_bufs
;
2546 struct inode
*inode
= page
->mapping
->host
;
2548 trace_ext4_da_writepage(inode
, page
);
2549 size
= i_size_read(inode
);
2550 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2551 len
= size
& ~PAGE_CACHE_MASK
;
2553 len
= PAGE_CACHE_SIZE
;
2555 if (page_has_buffers(page
)) {
2556 page_bufs
= page_buffers(page
);
2557 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2558 ext4_bh_unmapped_or_delay
)) {
2560 * We don't want to do block allocation
2561 * So redirty the page and return
2562 * We may reach here when we do a journal commit
2563 * via journal_submit_inode_data_buffers.
2564 * If we don't have mapping block we just ignore
2565 * them. We can also reach here via shrink_page_list
2567 redirty_page_for_writepage(wbc
, page
);
2573 * The test for page_has_buffers() is subtle:
2574 * We know the page is dirty but it lost buffers. That means
2575 * that at some moment in time after write_begin()/write_end()
2576 * has been called all buffers have been clean and thus they
2577 * must have been written at least once. So they are all
2578 * mapped and we can happily proceed with mapping them
2579 * and writing the page.
2581 * Try to initialize the buffer_heads and check whether
2582 * all are mapped and non delay. We don't want to
2583 * do block allocation here.
2585 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
2586 noalloc_get_block_write
);
2588 page_bufs
= page_buffers(page
);
2589 /* check whether all are mapped and non delay */
2590 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2591 ext4_bh_unmapped_or_delay
)) {
2592 redirty_page_for_writepage(wbc
, page
);
2598 * We can't do block allocation here
2599 * so just redity the page and unlock
2602 redirty_page_for_writepage(wbc
, page
);
2606 /* now mark the buffer_heads as dirty and uptodate */
2607 block_commit_write(page
, 0, PAGE_CACHE_SIZE
);
2610 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2611 ret
= nobh_writepage(page
, noalloc_get_block_write
, wbc
);
2613 ret
= block_write_full_page(page
, noalloc_get_block_write
,
2620 * This is called via ext4_da_writepages() to
2621 * calulate the total number of credits to reserve to fit
2622 * a single extent allocation into a single transaction,
2623 * ext4_da_writpeages() will loop calling this before
2624 * the block allocation.
2627 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2629 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2632 * With non-extent format the journal credit needed to
2633 * insert nrblocks contiguous block is dependent on
2634 * number of contiguous block. So we will limit
2635 * number of contiguous block to a sane value
2637 if (!(inode
->i_flags
& EXT4_EXTENTS_FL
) &&
2638 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2639 max_blocks
= EXT4_MAX_TRANS_DATA
;
2641 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2644 static int ext4_da_writepages(struct address_space
*mapping
,
2645 struct writeback_control
*wbc
)
2648 int range_whole
= 0;
2649 handle_t
*handle
= NULL
;
2650 struct mpage_da_data mpd
;
2651 struct inode
*inode
= mapping
->host
;
2652 int no_nrwrite_index_update
;
2653 int pages_written
= 0;
2655 int range_cyclic
, cycled
= 1, io_done
= 0;
2656 int needed_blocks
, ret
= 0, nr_to_writebump
= 0;
2657 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2659 trace_ext4_da_writepages(inode
, wbc
);
2662 * No pages to write? This is mainly a kludge to avoid starting
2663 * a transaction for special inodes like journal inode on last iput()
2664 * because that could violate lock ordering on umount
2666 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2670 * If the filesystem has aborted, it is read-only, so return
2671 * right away instead of dumping stack traces later on that
2672 * will obscure the real source of the problem. We test
2673 * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because
2674 * the latter could be true if the filesystem is mounted
2675 * read-only, and in that case, ext4_da_writepages should
2676 * *never* be called, so if that ever happens, we would want
2679 if (unlikely(sbi
->s_mount_opt
& EXT4_MOUNT_ABORT
))
2683 * Make sure nr_to_write is >= sbi->s_mb_stream_request
2684 * This make sure small files blocks are allocated in
2685 * single attempt. This ensure that small files
2686 * get less fragmented.
2688 if (wbc
->nr_to_write
< sbi
->s_mb_stream_request
) {
2689 nr_to_writebump
= sbi
->s_mb_stream_request
- wbc
->nr_to_write
;
2690 wbc
->nr_to_write
= sbi
->s_mb_stream_request
;
2692 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2695 range_cyclic
= wbc
->range_cyclic
;
2696 if (wbc
->range_cyclic
) {
2697 index
= mapping
->writeback_index
;
2700 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2701 wbc
->range_end
= LLONG_MAX
;
2702 wbc
->range_cyclic
= 0;
2704 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2707 mpd
.inode
= mapping
->host
;
2710 * we don't want write_cache_pages to update
2711 * nr_to_write and writeback_index
2713 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2714 wbc
->no_nrwrite_index_update
= 1;
2715 pages_skipped
= wbc
->pages_skipped
;
2718 while (!ret
&& wbc
->nr_to_write
> 0) {
2721 * we insert one extent at a time. So we need
2722 * credit needed for single extent allocation.
2723 * journalled mode is currently not supported
2726 BUG_ON(ext4_should_journal_data(inode
));
2727 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2729 /* start a new transaction*/
2730 handle
= ext4_journal_start(inode
, needed_blocks
);
2731 if (IS_ERR(handle
)) {
2732 ret
= PTR_ERR(handle
);
2733 printk(KERN_CRIT
"%s: jbd2_start: "
2734 "%ld pages, ino %lu; err %d\n", __func__
,
2735 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2737 goto out_writepages
;
2741 * Now call __mpage_da_writepage to find the next
2742 * contiguous region of logical blocks that need
2743 * blocks to be allocated by ext4. We don't actually
2744 * submit the blocks for I/O here, even though
2745 * write_cache_pages thinks it will, and will set the
2746 * pages as clean for write before calling
2747 * __mpage_da_writepage().
2755 mpd
.pages_written
= 0;
2757 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
,
2760 * If we have a contigous extent of pages and we
2761 * haven't done the I/O yet, map the blocks and submit
2764 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
2765 if (mpage_da_map_blocks(&mpd
) == 0)
2766 mpage_da_submit_io(&mpd
);
2768 ret
= MPAGE_DA_EXTENT_TAIL
;
2770 wbc
->nr_to_write
-= mpd
.pages_written
;
2772 ext4_journal_stop(handle
);
2774 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2775 /* commit the transaction which would
2776 * free blocks released in the transaction
2779 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2780 wbc
->pages_skipped
= pages_skipped
;
2782 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2784 * got one extent now try with
2787 pages_written
+= mpd
.pages_written
;
2788 wbc
->pages_skipped
= pages_skipped
;
2791 } else if (wbc
->nr_to_write
)
2793 * There is no more writeout needed
2794 * or we requested for a noblocking writeout
2795 * and we found the device congested
2799 if (!io_done
&& !cycled
) {
2802 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2803 wbc
->range_end
= mapping
->writeback_index
- 1;
2806 if (pages_skipped
!= wbc
->pages_skipped
)
2807 printk(KERN_EMERG
"This should not happen leaving %s "
2808 "with nr_to_write = %ld ret = %d\n",
2809 __func__
, wbc
->nr_to_write
, ret
);
2812 index
+= pages_written
;
2813 wbc
->range_cyclic
= range_cyclic
;
2814 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2816 * set the writeback_index so that range_cyclic
2817 * mode will write it back later
2819 mapping
->writeback_index
= index
;
2822 if (!no_nrwrite_index_update
)
2823 wbc
->no_nrwrite_index_update
= 0;
2824 wbc
->nr_to_write
-= nr_to_writebump
;
2825 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
2829 #define FALL_BACK_TO_NONDELALLOC 1
2830 static int ext4_nonda_switch(struct super_block
*sb
)
2832 s64 free_blocks
, dirty_blocks
;
2833 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2836 * switch to non delalloc mode if we are running low
2837 * on free block. The free block accounting via percpu
2838 * counters can get slightly wrong with percpu_counter_batch getting
2839 * accumulated on each CPU without updating global counters
2840 * Delalloc need an accurate free block accounting. So switch
2841 * to non delalloc when we are near to error range.
2843 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
2844 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
2845 if (2 * free_blocks
< 3 * dirty_blocks
||
2846 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
2848 * free block count is less that 150% of dirty blocks
2849 * or free blocks is less that watermark
2856 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
2857 loff_t pos
, unsigned len
, unsigned flags
,
2858 struct page
**pagep
, void **fsdata
)
2860 int ret
, retries
= 0;
2864 struct inode
*inode
= mapping
->host
;
2867 index
= pos
>> PAGE_CACHE_SHIFT
;
2868 from
= pos
& (PAGE_CACHE_SIZE
- 1);
2871 if (ext4_nonda_switch(inode
->i_sb
)) {
2872 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
2873 return ext4_write_begin(file
, mapping
, pos
,
2874 len
, flags
, pagep
, fsdata
);
2876 *fsdata
= (void *)0;
2877 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
2880 * With delayed allocation, we don't log the i_disksize update
2881 * if there is delayed block allocation. But we still need
2882 * to journalling the i_disksize update if writes to the end
2883 * of file which has an already mapped buffer.
2885 handle
= ext4_journal_start(inode
, 1);
2886 if (IS_ERR(handle
)) {
2887 ret
= PTR_ERR(handle
);
2890 /* We cannot recurse into the filesystem as the transaction is already
2892 flags
|= AOP_FLAG_NOFS
;
2894 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
2896 ext4_journal_stop(handle
);
2902 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
2903 ext4_da_get_block_prep
);
2906 ext4_journal_stop(handle
);
2907 page_cache_release(page
);
2909 * block_write_begin may have instantiated a few blocks
2910 * outside i_size. Trim these off again. Don't need
2911 * i_size_read because we hold i_mutex.
2913 if (pos
+ len
> inode
->i_size
)
2914 vmtruncate(inode
, inode
->i_size
);
2917 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
2924 * Check if we should update i_disksize
2925 * when write to the end of file but not require block allocation
2927 static int ext4_da_should_update_i_disksize(struct page
*page
,
2928 unsigned long offset
)
2930 struct buffer_head
*bh
;
2931 struct inode
*inode
= page
->mapping
->host
;
2935 bh
= page_buffers(page
);
2936 idx
= offset
>> inode
->i_blkbits
;
2938 for (i
= 0; i
< idx
; i
++)
2939 bh
= bh
->b_this_page
;
2941 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
2946 static int ext4_da_write_end(struct file
*file
,
2947 struct address_space
*mapping
,
2948 loff_t pos
, unsigned len
, unsigned copied
,
2949 struct page
*page
, void *fsdata
)
2951 struct inode
*inode
= mapping
->host
;
2953 handle_t
*handle
= ext4_journal_current_handle();
2955 unsigned long start
, end
;
2956 int write_mode
= (int)(unsigned long)fsdata
;
2958 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
2959 if (ext4_should_order_data(inode
)) {
2960 return ext4_ordered_write_end(file
, mapping
, pos
,
2961 len
, copied
, page
, fsdata
);
2962 } else if (ext4_should_writeback_data(inode
)) {
2963 return ext4_writeback_write_end(file
, mapping
, pos
,
2964 len
, copied
, page
, fsdata
);
2970 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
2971 start
= pos
& (PAGE_CACHE_SIZE
- 1);
2972 end
= start
+ copied
- 1;
2975 * generic_write_end() will run mark_inode_dirty() if i_size
2976 * changes. So let's piggyback the i_disksize mark_inode_dirty
2980 new_i_size
= pos
+ copied
;
2981 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2982 if (ext4_da_should_update_i_disksize(page
, end
)) {
2983 down_write(&EXT4_I(inode
)->i_data_sem
);
2984 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2986 * Updating i_disksize when extending file
2987 * without needing block allocation
2989 if (ext4_should_order_data(inode
))
2990 ret
= ext4_jbd2_file_inode(handle
,
2993 EXT4_I(inode
)->i_disksize
= new_i_size
;
2995 up_write(&EXT4_I(inode
)->i_data_sem
);
2996 /* We need to mark inode dirty even if
2997 * new_i_size is less that inode->i_size
2998 * bu greater than i_disksize.(hint delalloc)
3000 ext4_mark_inode_dirty(handle
, inode
);
3003 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
3008 ret2
= ext4_journal_stop(handle
);
3012 return ret
? ret
: copied
;
3015 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
3018 * Drop reserved blocks
3020 BUG_ON(!PageLocked(page
));
3021 if (!page_has_buffers(page
))
3024 ext4_da_page_release_reservation(page
, offset
);
3027 ext4_invalidatepage(page
, offset
);
3033 * Force all delayed allocation blocks to be allocated for a given inode.
3035 int ext4_alloc_da_blocks(struct inode
*inode
)
3037 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
3038 !EXT4_I(inode
)->i_reserved_meta_blocks
)
3042 * We do something simple for now. The filemap_flush() will
3043 * also start triggering a write of the data blocks, which is
3044 * not strictly speaking necessary (and for users of
3045 * laptop_mode, not even desirable). However, to do otherwise
3046 * would require replicating code paths in:
3048 * ext4_da_writepages() ->
3049 * write_cache_pages() ---> (via passed in callback function)
3050 * __mpage_da_writepage() -->
3051 * mpage_add_bh_to_extent()
3052 * mpage_da_map_blocks()
3054 * The problem is that write_cache_pages(), located in
3055 * mm/page-writeback.c, marks pages clean in preparation for
3056 * doing I/O, which is not desirable if we're not planning on
3059 * We could call write_cache_pages(), and then redirty all of
3060 * the pages by calling redirty_page_for_writeback() but that
3061 * would be ugly in the extreme. So instead we would need to
3062 * replicate parts of the code in the above functions,
3063 * simplifying them becuase we wouldn't actually intend to
3064 * write out the pages, but rather only collect contiguous
3065 * logical block extents, call the multi-block allocator, and
3066 * then update the buffer heads with the block allocations.
3068 * For now, though, we'll cheat by calling filemap_flush(),
3069 * which will map the blocks, and start the I/O, but not
3070 * actually wait for the I/O to complete.
3072 return filemap_flush(inode
->i_mapping
);
3076 * bmap() is special. It gets used by applications such as lilo and by
3077 * the swapper to find the on-disk block of a specific piece of data.
3079 * Naturally, this is dangerous if the block concerned is still in the
3080 * journal. If somebody makes a swapfile on an ext4 data-journaling
3081 * filesystem and enables swap, then they may get a nasty shock when the
3082 * data getting swapped to that swapfile suddenly gets overwritten by
3083 * the original zero's written out previously to the journal and
3084 * awaiting writeback in the kernel's buffer cache.
3086 * So, if we see any bmap calls here on a modified, data-journaled file,
3087 * take extra steps to flush any blocks which might be in the cache.
3089 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
3091 struct inode
*inode
= mapping
->host
;
3095 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
3096 test_opt(inode
->i_sb
, DELALLOC
)) {
3098 * With delalloc we want to sync the file
3099 * so that we can make sure we allocate
3102 filemap_write_and_wait(mapping
);
3105 if (EXT4_JOURNAL(inode
) && EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
3107 * This is a REALLY heavyweight approach, but the use of
3108 * bmap on dirty files is expected to be extremely rare:
3109 * only if we run lilo or swapon on a freshly made file
3110 * do we expect this to happen.
3112 * (bmap requires CAP_SYS_RAWIO so this does not
3113 * represent an unprivileged user DOS attack --- we'd be
3114 * in trouble if mortal users could trigger this path at
3117 * NB. EXT4_STATE_JDATA is not set on files other than
3118 * regular files. If somebody wants to bmap a directory
3119 * or symlink and gets confused because the buffer
3120 * hasn't yet been flushed to disk, they deserve
3121 * everything they get.
3124 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
3125 journal
= EXT4_JOURNAL(inode
);
3126 jbd2_journal_lock_updates(journal
);
3127 err
= jbd2_journal_flush(journal
);
3128 jbd2_journal_unlock_updates(journal
);
3134 return generic_block_bmap(mapping
, block
, ext4_get_block
);
3137 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
3143 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
3150 * Note that we don't need to start a transaction unless we're journaling data
3151 * because we should have holes filled from ext4_page_mkwrite(). We even don't
3152 * need to file the inode to the transaction's list in ordered mode because if
3153 * we are writing back data added by write(), the inode is already there and if
3154 * we are writing back data modified via mmap(), noone guarantees in which
3155 * transaction the data will hit the disk. In case we are journaling data, we
3156 * cannot start transaction directly because transaction start ranks above page
3157 * lock so we have to do some magic.
3159 * In all journaling modes block_write_full_page() will start the I/O.
3163 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
3168 * ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ...
3170 * Same applies to ext4_get_block(). We will deadlock on various things like
3171 * lock_journal and i_data_sem
3173 * Setting PF_MEMALLOC here doesn't work - too many internal memory
3176 * 16May01: If we're reentered then journal_current_handle() will be
3177 * non-zero. We simply *return*.
3179 * 1 July 2001: @@@ FIXME:
3180 * In journalled data mode, a data buffer may be metadata against the
3181 * current transaction. But the same file is part of a shared mapping
3182 * and someone does a writepage() on it.
3184 * We will move the buffer onto the async_data list, but *after* it has
3185 * been dirtied. So there's a small window where we have dirty data on
3188 * Note that this only applies to the last partial page in the file. The
3189 * bit which block_write_full_page() uses prepare/commit for. (That's
3190 * broken code anyway: it's wrong for msync()).
3192 * It's a rare case: affects the final partial page, for journalled data
3193 * where the file is subject to bith write() and writepage() in the same
3194 * transction. To fix it we'll need a custom block_write_full_page().
3195 * We'll probably need that anyway for journalling writepage() output.
3197 * We don't honour synchronous mounts for writepage(). That would be
3198 * disastrous. Any write() or metadata operation will sync the fs for
3202 static int __ext4_normal_writepage(struct page
*page
,
3203 struct writeback_control
*wbc
)
3205 struct inode
*inode
= page
->mapping
->host
;
3207 if (test_opt(inode
->i_sb
, NOBH
))
3208 return nobh_writepage(page
, noalloc_get_block_write
, wbc
);
3210 return block_write_full_page(page
, noalloc_get_block_write
,
3214 static int ext4_normal_writepage(struct page
*page
,
3215 struct writeback_control
*wbc
)
3217 struct inode
*inode
= page
->mapping
->host
;
3218 loff_t size
= i_size_read(inode
);
3221 trace_ext4_normal_writepage(inode
, page
);
3222 J_ASSERT(PageLocked(page
));
3223 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
3224 len
= size
& ~PAGE_CACHE_MASK
;
3226 len
= PAGE_CACHE_SIZE
;
3228 if (page_has_buffers(page
)) {
3229 /* if page has buffers it should all be mapped
3230 * and allocated. If there are not buffers attached
3231 * to the page we know the page is dirty but it lost
3232 * buffers. That means that at some moment in time
3233 * after write_begin() / write_end() has been called
3234 * all buffers have been clean and thus they must have been
3235 * written at least once. So they are all mapped and we can
3236 * happily proceed with mapping them and writing the page.
3238 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
3239 ext4_bh_unmapped_or_delay
));
3242 if (!ext4_journal_current_handle())
3243 return __ext4_normal_writepage(page
, wbc
);
3245 redirty_page_for_writepage(wbc
, page
);
3250 static int __ext4_journalled_writepage(struct page
*page
,
3251 struct writeback_control
*wbc
)
3253 struct address_space
*mapping
= page
->mapping
;
3254 struct inode
*inode
= mapping
->host
;
3255 struct buffer_head
*page_bufs
;
3256 handle_t
*handle
= NULL
;
3260 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
3261 noalloc_get_block_write
);
3265 page_bufs
= page_buffers(page
);
3266 walk_page_buffers(handle
, page_bufs
, 0, PAGE_CACHE_SIZE
, NULL
,
3268 /* As soon as we unlock the page, it can go away, but we have
3269 * references to buffers so we are safe */
3272 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
3273 if (IS_ERR(handle
)) {
3274 ret
= PTR_ERR(handle
);
3278 ret
= walk_page_buffers(handle
, page_bufs
, 0,
3279 PAGE_CACHE_SIZE
, NULL
, do_journal_get_write_access
);
3281 err
= walk_page_buffers(handle
, page_bufs
, 0,
3282 PAGE_CACHE_SIZE
, NULL
, write_end_fn
);
3285 err
= ext4_journal_stop(handle
);
3289 walk_page_buffers(handle
, page_bufs
, 0,
3290 PAGE_CACHE_SIZE
, NULL
, bput_one
);
3291 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
3300 static int ext4_journalled_writepage(struct page
*page
,
3301 struct writeback_control
*wbc
)
3303 struct inode
*inode
= page
->mapping
->host
;
3304 loff_t size
= i_size_read(inode
);
3307 trace_ext4_journalled_writepage(inode
, page
);
3308 J_ASSERT(PageLocked(page
));
3309 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
3310 len
= size
& ~PAGE_CACHE_MASK
;
3312 len
= PAGE_CACHE_SIZE
;
3314 if (page_has_buffers(page
)) {
3315 /* if page has buffers it should all be mapped
3316 * and allocated. If there are not buffers attached
3317 * to the page we know the page is dirty but it lost
3318 * buffers. That means that at some moment in time
3319 * after write_begin() / write_end() has been called
3320 * all buffers have been clean and thus they must have been
3321 * written at least once. So they are all mapped and we can
3322 * happily proceed with mapping them and writing the page.
3324 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
3325 ext4_bh_unmapped_or_delay
));
3328 if (ext4_journal_current_handle())
3331 if (PageChecked(page
)) {
3333 * It's mmapped pagecache. Add buffers and journal it. There
3334 * doesn't seem much point in redirtying the page here.
3336 ClearPageChecked(page
);
3337 return __ext4_journalled_writepage(page
, wbc
);
3340 * It may be a page full of checkpoint-mode buffers. We don't
3341 * really know unless we go poke around in the buffer_heads.
3342 * But block_write_full_page will do the right thing.
3344 return block_write_full_page(page
, noalloc_get_block_write
,
3348 redirty_page_for_writepage(wbc
, page
);
3353 static int ext4_readpage(struct file
*file
, struct page
*page
)
3355 return mpage_readpage(page
, ext4_get_block
);
3359 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3360 struct list_head
*pages
, unsigned nr_pages
)
3362 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3365 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3367 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3370 * If it's a full truncate we just forget about the pending dirtying
3373 ClearPageChecked(page
);
3376 jbd2_journal_invalidatepage(journal
, page
, offset
);
3378 block_invalidatepage(page
, offset
);
3381 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3383 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3385 WARN_ON(PageChecked(page
));
3386 if (!page_has_buffers(page
))
3389 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3391 return try_to_free_buffers(page
);
3395 * If the O_DIRECT write will extend the file then add this inode to the
3396 * orphan list. So recovery will truncate it back to the original size
3397 * if the machine crashes during the write.
3399 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3400 * crashes then stale disk data _may_ be exposed inside the file. But current
3401 * VFS code falls back into buffered path in that case so we are safe.
3403 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3404 const struct iovec
*iov
, loff_t offset
,
3405 unsigned long nr_segs
)
3407 struct file
*file
= iocb
->ki_filp
;
3408 struct inode
*inode
= file
->f_mapping
->host
;
3409 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3413 size_t count
= iov_length(iov
, nr_segs
);
3416 loff_t final_size
= offset
+ count
;
3418 if (final_size
> inode
->i_size
) {
3419 /* Credits for sb + inode write */
3420 handle
= ext4_journal_start(inode
, 2);
3421 if (IS_ERR(handle
)) {
3422 ret
= PTR_ERR(handle
);
3425 ret
= ext4_orphan_add(handle
, inode
);
3427 ext4_journal_stop(handle
);
3431 ei
->i_disksize
= inode
->i_size
;
3432 ext4_journal_stop(handle
);
3436 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3438 ext4_get_block
, NULL
);
3443 /* Credits for sb + inode write */
3444 handle
= ext4_journal_start(inode
, 2);
3445 if (IS_ERR(handle
)) {
3446 /* This is really bad luck. We've written the data
3447 * but cannot extend i_size. Bail out and pretend
3448 * the write failed... */
3449 ret
= PTR_ERR(handle
);
3453 ext4_orphan_del(handle
, inode
);
3455 loff_t end
= offset
+ ret
;
3456 if (end
> inode
->i_size
) {
3457 ei
->i_disksize
= end
;
3458 i_size_write(inode
, end
);
3460 * We're going to return a positive `ret'
3461 * here due to non-zero-length I/O, so there's
3462 * no way of reporting error returns from
3463 * ext4_mark_inode_dirty() to userspace. So
3466 ext4_mark_inode_dirty(handle
, inode
);
3469 err
= ext4_journal_stop(handle
);
3478 * Pages can be marked dirty completely asynchronously from ext4's journalling
3479 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3480 * much here because ->set_page_dirty is called under VFS locks. The page is
3481 * not necessarily locked.
3483 * We cannot just dirty the page and leave attached buffers clean, because the
3484 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3485 * or jbddirty because all the journalling code will explode.
3487 * So what we do is to mark the page "pending dirty" and next time writepage
3488 * is called, propagate that into the buffers appropriately.
3490 static int ext4_journalled_set_page_dirty(struct page
*page
)
3492 SetPageChecked(page
);
3493 return __set_page_dirty_nobuffers(page
);
3496 static const struct address_space_operations ext4_ordered_aops
= {
3497 .readpage
= ext4_readpage
,
3498 .readpages
= ext4_readpages
,
3499 .writepage
= ext4_normal_writepage
,
3500 .sync_page
= block_sync_page
,
3501 .write_begin
= ext4_write_begin
,
3502 .write_end
= ext4_ordered_write_end
,
3504 .invalidatepage
= ext4_invalidatepage
,
3505 .releasepage
= ext4_releasepage
,
3506 .direct_IO
= ext4_direct_IO
,
3507 .migratepage
= buffer_migrate_page
,
3508 .is_partially_uptodate
= block_is_partially_uptodate
,
3511 static const struct address_space_operations ext4_writeback_aops
= {
3512 .readpage
= ext4_readpage
,
3513 .readpages
= ext4_readpages
,
3514 .writepage
= ext4_normal_writepage
,
3515 .sync_page
= block_sync_page
,
3516 .write_begin
= ext4_write_begin
,
3517 .write_end
= ext4_writeback_write_end
,
3519 .invalidatepage
= ext4_invalidatepage
,
3520 .releasepage
= ext4_releasepage
,
3521 .direct_IO
= ext4_direct_IO
,
3522 .migratepage
= buffer_migrate_page
,
3523 .is_partially_uptodate
= block_is_partially_uptodate
,
3526 static const struct address_space_operations ext4_journalled_aops
= {
3527 .readpage
= ext4_readpage
,
3528 .readpages
= ext4_readpages
,
3529 .writepage
= ext4_journalled_writepage
,
3530 .sync_page
= block_sync_page
,
3531 .write_begin
= ext4_write_begin
,
3532 .write_end
= ext4_journalled_write_end
,
3533 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3535 .invalidatepage
= ext4_invalidatepage
,
3536 .releasepage
= ext4_releasepage
,
3537 .is_partially_uptodate
= block_is_partially_uptodate
,
3540 static const struct address_space_operations ext4_da_aops
= {
3541 .readpage
= ext4_readpage
,
3542 .readpages
= ext4_readpages
,
3543 .writepage
= ext4_da_writepage
,
3544 .writepages
= ext4_da_writepages
,
3545 .sync_page
= block_sync_page
,
3546 .write_begin
= ext4_da_write_begin
,
3547 .write_end
= ext4_da_write_end
,
3549 .invalidatepage
= ext4_da_invalidatepage
,
3550 .releasepage
= ext4_releasepage
,
3551 .direct_IO
= ext4_direct_IO
,
3552 .migratepage
= buffer_migrate_page
,
3553 .is_partially_uptodate
= block_is_partially_uptodate
,
3556 void ext4_set_aops(struct inode
*inode
)
3558 if (ext4_should_order_data(inode
) &&
3559 test_opt(inode
->i_sb
, DELALLOC
))
3560 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3561 else if (ext4_should_order_data(inode
))
3562 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3563 else if (ext4_should_writeback_data(inode
) &&
3564 test_opt(inode
->i_sb
, DELALLOC
))
3565 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3566 else if (ext4_should_writeback_data(inode
))
3567 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3569 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3573 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3574 * up to the end of the block which corresponds to `from'.
3575 * This required during truncate. We need to physically zero the tail end
3576 * of that block so it doesn't yield old data if the file is later grown.
3578 int ext4_block_truncate_page(handle_t
*handle
,
3579 struct address_space
*mapping
, loff_t from
)
3581 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3582 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3583 unsigned blocksize
, length
, pos
;
3585 struct inode
*inode
= mapping
->host
;
3586 struct buffer_head
*bh
;
3590 page
= grab_cache_page(mapping
, from
>> PAGE_CACHE_SHIFT
);
3594 blocksize
= inode
->i_sb
->s_blocksize
;
3595 length
= blocksize
- (offset
& (blocksize
- 1));
3596 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3599 * For "nobh" option, we can only work if we don't need to
3600 * read-in the page - otherwise we create buffers to do the IO.
3602 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3603 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3604 zero_user(page
, offset
, length
);
3605 set_page_dirty(page
);
3609 if (!page_has_buffers(page
))
3610 create_empty_buffers(page
, blocksize
, 0);
3612 /* Find the buffer that contains "offset" */
3613 bh
= page_buffers(page
);
3615 while (offset
>= pos
) {
3616 bh
= bh
->b_this_page
;
3622 if (buffer_freed(bh
)) {
3623 BUFFER_TRACE(bh
, "freed: skip");
3627 if (!buffer_mapped(bh
)) {
3628 BUFFER_TRACE(bh
, "unmapped");
3629 ext4_get_block(inode
, iblock
, bh
, 0);
3630 /* unmapped? It's a hole - nothing to do */
3631 if (!buffer_mapped(bh
)) {
3632 BUFFER_TRACE(bh
, "still unmapped");
3637 /* Ok, it's mapped. Make sure it's up-to-date */
3638 if (PageUptodate(page
))
3639 set_buffer_uptodate(bh
);
3641 if (!buffer_uptodate(bh
)) {
3643 ll_rw_block(READ
, 1, &bh
);
3645 /* Uhhuh. Read error. Complain and punt. */
3646 if (!buffer_uptodate(bh
))
3650 if (ext4_should_journal_data(inode
)) {
3651 BUFFER_TRACE(bh
, "get write access");
3652 err
= ext4_journal_get_write_access(handle
, bh
);
3657 zero_user(page
, offset
, length
);
3659 BUFFER_TRACE(bh
, "zeroed end of block");
3662 if (ext4_should_journal_data(inode
)) {
3663 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
3665 if (ext4_should_order_data(inode
))
3666 err
= ext4_jbd2_file_inode(handle
, inode
);
3667 mark_buffer_dirty(bh
);
3672 page_cache_release(page
);
3677 * Probably it should be a library function... search for first non-zero word
3678 * or memcmp with zero_page, whatever is better for particular architecture.
3681 static inline int all_zeroes(__le32
*p
, __le32
*q
)
3690 * ext4_find_shared - find the indirect blocks for partial truncation.
3691 * @inode: inode in question
3692 * @depth: depth of the affected branch
3693 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
3694 * @chain: place to store the pointers to partial indirect blocks
3695 * @top: place to the (detached) top of branch
3697 * This is a helper function used by ext4_truncate().
3699 * When we do truncate() we may have to clean the ends of several
3700 * indirect blocks but leave the blocks themselves alive. Block is
3701 * partially truncated if some data below the new i_size is refered
3702 * from it (and it is on the path to the first completely truncated
3703 * data block, indeed). We have to free the top of that path along
3704 * with everything to the right of the path. Since no allocation
3705 * past the truncation point is possible until ext4_truncate()
3706 * finishes, we may safely do the latter, but top of branch may
3707 * require special attention - pageout below the truncation point
3708 * might try to populate it.
3710 * We atomically detach the top of branch from the tree, store the
3711 * block number of its root in *@top, pointers to buffer_heads of
3712 * partially truncated blocks - in @chain[].bh and pointers to
3713 * their last elements that should not be removed - in
3714 * @chain[].p. Return value is the pointer to last filled element
3717 * The work left to caller to do the actual freeing of subtrees:
3718 * a) free the subtree starting from *@top
3719 * b) free the subtrees whose roots are stored in
3720 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
3721 * c) free the subtrees growing from the inode past the @chain[0].
3722 * (no partially truncated stuff there). */
3724 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
3725 ext4_lblk_t offsets
[4], Indirect chain
[4], __le32
*top
)
3727 Indirect
*partial
, *p
;
3731 /* Make k index the deepest non-null offest + 1 */
3732 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
3734 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
3735 /* Writer: pointers */
3737 partial
= chain
+ k
-1;
3739 * If the branch acquired continuation since we've looked at it -
3740 * fine, it should all survive and (new) top doesn't belong to us.
3742 if (!partial
->key
&& *partial
->p
)
3745 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
3748 * OK, we've found the last block that must survive. The rest of our
3749 * branch should be detached before unlocking. However, if that rest
3750 * of branch is all ours and does not grow immediately from the inode
3751 * it's easier to cheat and just decrement partial->p.
3753 if (p
== chain
+ k
- 1 && p
> chain
) {
3757 /* Nope, don't do this in ext4. Must leave the tree intact */
3764 while (partial
> p
) {
3765 brelse(partial
->bh
);
3773 * Zero a number of block pointers in either an inode or an indirect block.
3774 * If we restart the transaction we must again get write access to the
3775 * indirect block for further modification.
3777 * We release `count' blocks on disk, but (last - first) may be greater
3778 * than `count' because there can be holes in there.
3780 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
3781 struct buffer_head
*bh
, ext4_fsblk_t block_to_free
,
3782 unsigned long count
, __le32
*first
, __le32
*last
)
3785 if (try_to_extend_transaction(handle
, inode
)) {
3787 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
3788 ext4_handle_dirty_metadata(handle
, inode
, bh
);
3790 ext4_mark_inode_dirty(handle
, inode
);
3791 ext4_journal_test_restart(handle
, inode
);
3793 BUFFER_TRACE(bh
, "retaking write access");
3794 ext4_journal_get_write_access(handle
, bh
);
3799 * Any buffers which are on the journal will be in memory. We find
3800 * them on the hash table so jbd2_journal_revoke() will run jbd2_journal_forget()
3801 * on them. We've already detached each block from the file, so
3802 * bforget() in jbd2_journal_forget() should be safe.
3804 * AKPM: turn on bforget in jbd2_journal_forget()!!!
3806 for (p
= first
; p
< last
; p
++) {
3807 u32 nr
= le32_to_cpu(*p
);
3809 struct buffer_head
*tbh
;
3812 tbh
= sb_find_get_block(inode
->i_sb
, nr
);
3813 ext4_forget(handle
, 0, inode
, tbh
, nr
);
3817 ext4_free_blocks(handle
, inode
, block_to_free
, count
, 0);
3821 * ext4_free_data - free a list of data blocks
3822 * @handle: handle for this transaction
3823 * @inode: inode we are dealing with
3824 * @this_bh: indirect buffer_head which contains *@first and *@last
3825 * @first: array of block numbers
3826 * @last: points immediately past the end of array
3828 * We are freeing all blocks refered from that array (numbers are stored as
3829 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
3831 * We accumulate contiguous runs of blocks to free. Conveniently, if these
3832 * blocks are contiguous then releasing them at one time will only affect one
3833 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
3834 * actually use a lot of journal space.
3836 * @this_bh will be %NULL if @first and @last point into the inode's direct
3839 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
3840 struct buffer_head
*this_bh
,
3841 __le32
*first
, __le32
*last
)
3843 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
3844 unsigned long count
= 0; /* Number of blocks in the run */
3845 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
3848 ext4_fsblk_t nr
; /* Current block # */
3849 __le32
*p
; /* Pointer into inode/ind
3850 for current block */
3853 if (this_bh
) { /* For indirect block */
3854 BUFFER_TRACE(this_bh
, "get_write_access");
3855 err
= ext4_journal_get_write_access(handle
, this_bh
);
3856 /* Important: if we can't update the indirect pointers
3857 * to the blocks, we can't free them. */
3862 for (p
= first
; p
< last
; p
++) {
3863 nr
= le32_to_cpu(*p
);
3865 /* accumulate blocks to free if they're contiguous */
3868 block_to_free_p
= p
;
3870 } else if (nr
== block_to_free
+ count
) {
3873 ext4_clear_blocks(handle
, inode
, this_bh
,
3875 count
, block_to_free_p
, p
);
3877 block_to_free_p
= p
;
3884 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
3885 count
, block_to_free_p
, p
);
3888 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
3891 * The buffer head should have an attached journal head at this
3892 * point. However, if the data is corrupted and an indirect
3893 * block pointed to itself, it would have been detached when
3894 * the block was cleared. Check for this instead of OOPSing.
3896 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
3897 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
3899 ext4_error(inode
->i_sb
, __func__
,
3900 "circular indirect block detected, "
3901 "inode=%lu, block=%llu",
3903 (unsigned long long) this_bh
->b_blocknr
);
3908 * ext4_free_branches - free an array of branches
3909 * @handle: JBD handle for this transaction
3910 * @inode: inode we are dealing with
3911 * @parent_bh: the buffer_head which contains *@first and *@last
3912 * @first: array of block numbers
3913 * @last: pointer immediately past the end of array
3914 * @depth: depth of the branches to free
3916 * We are freeing all blocks refered from these branches (numbers are
3917 * stored as little-endian 32-bit) and updating @inode->i_blocks
3920 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
3921 struct buffer_head
*parent_bh
,
3922 __le32
*first
, __le32
*last
, int depth
)
3927 if (ext4_handle_is_aborted(handle
))
3931 struct buffer_head
*bh
;
3932 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
3934 while (--p
>= first
) {
3935 nr
= le32_to_cpu(*p
);
3937 continue; /* A hole */
3939 /* Go read the buffer for the next level down */
3940 bh
= sb_bread(inode
->i_sb
, nr
);
3943 * A read failure? Report error and clear slot
3947 ext4_error(inode
->i_sb
, "ext4_free_branches",
3948 "Read failure, inode=%lu, block=%llu",
3953 /* This zaps the entire block. Bottom up. */
3954 BUFFER_TRACE(bh
, "free child branches");
3955 ext4_free_branches(handle
, inode
, bh
,
3956 (__le32
*) bh
->b_data
,
3957 (__le32
*) bh
->b_data
+ addr_per_block
,
3961 * We've probably journalled the indirect block several
3962 * times during the truncate. But it's no longer
3963 * needed and we now drop it from the transaction via
3964 * jbd2_journal_revoke().
3966 * That's easy if it's exclusively part of this
3967 * transaction. But if it's part of the committing
3968 * transaction then jbd2_journal_forget() will simply
3969 * brelse() it. That means that if the underlying
3970 * block is reallocated in ext4_get_block(),
3971 * unmap_underlying_metadata() will find this block
3972 * and will try to get rid of it. damn, damn.
3974 * If this block has already been committed to the
3975 * journal, a revoke record will be written. And
3976 * revoke records must be emitted *before* clearing
3977 * this block's bit in the bitmaps.
3979 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
3982 * Everything below this this pointer has been
3983 * released. Now let this top-of-subtree go.
3985 * We want the freeing of this indirect block to be
3986 * atomic in the journal with the updating of the
3987 * bitmap block which owns it. So make some room in
3990 * We zero the parent pointer *after* freeing its
3991 * pointee in the bitmaps, so if extend_transaction()
3992 * for some reason fails to put the bitmap changes and
3993 * the release into the same transaction, recovery
3994 * will merely complain about releasing a free block,
3995 * rather than leaking blocks.
3997 if (ext4_handle_is_aborted(handle
))
3999 if (try_to_extend_transaction(handle
, inode
)) {
4000 ext4_mark_inode_dirty(handle
, inode
);
4001 ext4_journal_test_restart(handle
, inode
);
4004 ext4_free_blocks(handle
, inode
, nr
, 1, 1);
4008 * The block which we have just freed is
4009 * pointed to by an indirect block: journal it
4011 BUFFER_TRACE(parent_bh
, "get_write_access");
4012 if (!ext4_journal_get_write_access(handle
,
4015 BUFFER_TRACE(parent_bh
,
4016 "call ext4_handle_dirty_metadata");
4017 ext4_handle_dirty_metadata(handle
,
4024 /* We have reached the bottom of the tree. */
4025 BUFFER_TRACE(parent_bh
, "free data blocks");
4026 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
4030 int ext4_can_truncate(struct inode
*inode
)
4032 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
4034 if (S_ISREG(inode
->i_mode
))
4036 if (S_ISDIR(inode
->i_mode
))
4038 if (S_ISLNK(inode
->i_mode
))
4039 return !ext4_inode_is_fast_symlink(inode
);
4046 * We block out ext4_get_block() block instantiations across the entire
4047 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4048 * simultaneously on behalf of the same inode.
4050 * As we work through the truncate and commmit bits of it to the journal there
4051 * is one core, guiding principle: the file's tree must always be consistent on
4052 * disk. We must be able to restart the truncate after a crash.
4054 * The file's tree may be transiently inconsistent in memory (although it
4055 * probably isn't), but whenever we close off and commit a journal transaction,
4056 * the contents of (the filesystem + the journal) must be consistent and
4057 * restartable. It's pretty simple, really: bottom up, right to left (although
4058 * left-to-right works OK too).
4060 * Note that at recovery time, journal replay occurs *before* the restart of
4061 * truncate against the orphan inode list.
4063 * The committed inode has the new, desired i_size (which is the same as
4064 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4065 * that this inode's truncate did not complete and it will again call
4066 * ext4_truncate() to have another go. So there will be instantiated blocks
4067 * to the right of the truncation point in a crashed ext4 filesystem. But
4068 * that's fine - as long as they are linked from the inode, the post-crash
4069 * ext4_truncate() run will find them and release them.
4071 void ext4_truncate(struct inode
*inode
)
4074 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4075 __le32
*i_data
= ei
->i_data
;
4076 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4077 struct address_space
*mapping
= inode
->i_mapping
;
4078 ext4_lblk_t offsets
[4];
4083 ext4_lblk_t last_block
;
4084 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
4086 if (!ext4_can_truncate(inode
))
4089 if (ei
->i_disksize
&& inode
->i_size
== 0 &&
4090 !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
4091 ei
->i_state
|= EXT4_STATE_DA_ALLOC_CLOSE
;
4093 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
4094 ext4_ext_truncate(inode
);
4098 handle
= start_transaction(inode
);
4100 return; /* AKPM: return what? */
4102 last_block
= (inode
->i_size
+ blocksize
-1)
4103 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
4105 if (inode
->i_size
& (blocksize
- 1))
4106 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
4109 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
4111 goto out_stop
; /* error */
4114 * OK. This truncate is going to happen. We add the inode to the
4115 * orphan list, so that if this truncate spans multiple transactions,
4116 * and we crash, we will resume the truncate when the filesystem
4117 * recovers. It also marks the inode dirty, to catch the new size.
4119 * Implication: the file must always be in a sane, consistent
4120 * truncatable state while each transaction commits.
4122 if (ext4_orphan_add(handle
, inode
))
4126 * From here we block out all ext4_get_block() callers who want to
4127 * modify the block allocation tree.
4129 down_write(&ei
->i_data_sem
);
4131 ext4_discard_preallocations(inode
);
4134 * The orphan list entry will now protect us from any crash which
4135 * occurs before the truncate completes, so it is now safe to propagate
4136 * the new, shorter inode size (held for now in i_size) into the
4137 * on-disk inode. We do this via i_disksize, which is the value which
4138 * ext4 *really* writes onto the disk inode.
4140 ei
->i_disksize
= inode
->i_size
;
4142 if (n
== 1) { /* direct blocks */
4143 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
4144 i_data
+ EXT4_NDIR_BLOCKS
);
4148 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
4149 /* Kill the top of shared branch (not detached) */
4151 if (partial
== chain
) {
4152 /* Shared branch grows from the inode */
4153 ext4_free_branches(handle
, inode
, NULL
,
4154 &nr
, &nr
+1, (chain
+n
-1) - partial
);
4157 * We mark the inode dirty prior to restart,
4158 * and prior to stop. No need for it here.
4161 /* Shared branch grows from an indirect block */
4162 BUFFER_TRACE(partial
->bh
, "get_write_access");
4163 ext4_free_branches(handle
, inode
, partial
->bh
,
4165 partial
->p
+1, (chain
+n
-1) - partial
);
4168 /* Clear the ends of indirect blocks on the shared branch */
4169 while (partial
> chain
) {
4170 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
4171 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
4172 (chain
+n
-1) - partial
);
4173 BUFFER_TRACE(partial
->bh
, "call brelse");
4174 brelse (partial
->bh
);
4178 /* Kill the remaining (whole) subtrees */
4179 switch (offsets
[0]) {
4181 nr
= i_data
[EXT4_IND_BLOCK
];
4183 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4184 i_data
[EXT4_IND_BLOCK
] = 0;
4186 case EXT4_IND_BLOCK
:
4187 nr
= i_data
[EXT4_DIND_BLOCK
];
4189 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4190 i_data
[EXT4_DIND_BLOCK
] = 0;
4192 case EXT4_DIND_BLOCK
:
4193 nr
= i_data
[EXT4_TIND_BLOCK
];
4195 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4196 i_data
[EXT4_TIND_BLOCK
] = 0;
4198 case EXT4_TIND_BLOCK
:
4202 up_write(&ei
->i_data_sem
);
4203 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4204 ext4_mark_inode_dirty(handle
, inode
);
4207 * In a multi-transaction truncate, we only make the final transaction
4211 ext4_handle_sync(handle
);
4214 * If this was a simple ftruncate(), and the file will remain alive
4215 * then we need to clear up the orphan record which we created above.
4216 * However, if this was a real unlink then we were called by
4217 * ext4_delete_inode(), and we allow that function to clean up the
4218 * orphan info for us.
4221 ext4_orphan_del(handle
, inode
);
4223 ext4_journal_stop(handle
);
4227 * ext4_get_inode_loc returns with an extra refcount against the inode's
4228 * underlying buffer_head on success. If 'in_mem' is true, we have all
4229 * data in memory that is needed to recreate the on-disk version of this
4232 static int __ext4_get_inode_loc(struct inode
*inode
,
4233 struct ext4_iloc
*iloc
, int in_mem
)
4235 struct ext4_group_desc
*gdp
;
4236 struct buffer_head
*bh
;
4237 struct super_block
*sb
= inode
->i_sb
;
4239 int inodes_per_block
, inode_offset
;
4242 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4245 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4246 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4251 * Figure out the offset within the block group inode table
4253 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4254 inode_offset
= ((inode
->i_ino
- 1) %
4255 EXT4_INODES_PER_GROUP(sb
));
4256 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4257 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4259 bh
= sb_getblk(sb
, block
);
4261 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
4262 "inode block - inode=%lu, block=%llu",
4263 inode
->i_ino
, block
);
4266 if (!buffer_uptodate(bh
)) {
4270 * If the buffer has the write error flag, we have failed
4271 * to write out another inode in the same block. In this
4272 * case, we don't have to read the block because we may
4273 * read the old inode data successfully.
4275 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4276 set_buffer_uptodate(bh
);
4278 if (buffer_uptodate(bh
)) {
4279 /* someone brought it uptodate while we waited */
4285 * If we have all information of the inode in memory and this
4286 * is the only valid inode in the block, we need not read the
4290 struct buffer_head
*bitmap_bh
;
4293 start
= inode_offset
& ~(inodes_per_block
- 1);
4295 /* Is the inode bitmap in cache? */
4296 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4301 * If the inode bitmap isn't in cache then the
4302 * optimisation may end up performing two reads instead
4303 * of one, so skip it.
4305 if (!buffer_uptodate(bitmap_bh
)) {
4309 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4310 if (i
== inode_offset
)
4312 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4316 if (i
== start
+ inodes_per_block
) {
4317 /* all other inodes are free, so skip I/O */
4318 memset(bh
->b_data
, 0, bh
->b_size
);
4319 set_buffer_uptodate(bh
);
4327 * If we need to do any I/O, try to pre-readahead extra
4328 * blocks from the inode table.
4330 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4331 ext4_fsblk_t b
, end
, table
;
4334 table
= ext4_inode_table(sb
, gdp
);
4335 /* s_inode_readahead_blks is always a power of 2 */
4336 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4339 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4340 num
= EXT4_INODES_PER_GROUP(sb
);
4341 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4342 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4343 num
-= ext4_itable_unused_count(sb
, gdp
);
4344 table
+= num
/ inodes_per_block
;
4348 sb_breadahead(sb
, b
++);
4352 * There are other valid inodes in the buffer, this inode
4353 * has in-inode xattrs, or we don't have this inode in memory.
4354 * Read the block from disk.
4357 bh
->b_end_io
= end_buffer_read_sync
;
4358 submit_bh(READ_META
, bh
);
4360 if (!buffer_uptodate(bh
)) {
4361 ext4_error(sb
, __func__
,
4362 "unable to read inode block - inode=%lu, "
4363 "block=%llu", inode
->i_ino
, block
);
4373 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4375 /* We have all inode data except xattrs in memory here. */
4376 return __ext4_get_inode_loc(inode
, iloc
,
4377 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4380 void ext4_set_inode_flags(struct inode
*inode
)
4382 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4384 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4385 if (flags
& EXT4_SYNC_FL
)
4386 inode
->i_flags
|= S_SYNC
;
4387 if (flags
& EXT4_APPEND_FL
)
4388 inode
->i_flags
|= S_APPEND
;
4389 if (flags
& EXT4_IMMUTABLE_FL
)
4390 inode
->i_flags
|= S_IMMUTABLE
;
4391 if (flags
& EXT4_NOATIME_FL
)
4392 inode
->i_flags
|= S_NOATIME
;
4393 if (flags
& EXT4_DIRSYNC_FL
)
4394 inode
->i_flags
|= S_DIRSYNC
;
4397 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4398 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4400 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4402 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4403 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4405 ei
->i_flags
|= EXT4_SYNC_FL
;
4406 if (flags
& S_APPEND
)
4407 ei
->i_flags
|= EXT4_APPEND_FL
;
4408 if (flags
& S_IMMUTABLE
)
4409 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4410 if (flags
& S_NOATIME
)
4411 ei
->i_flags
|= EXT4_NOATIME_FL
;
4412 if (flags
& S_DIRSYNC
)
4413 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4415 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4416 struct ext4_inode_info
*ei
)
4419 struct inode
*inode
= &(ei
->vfs_inode
);
4420 struct super_block
*sb
= inode
->i_sb
;
4422 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4423 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4424 /* we are using combined 48 bit field */
4425 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4426 le32_to_cpu(raw_inode
->i_blocks_lo
);
4427 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4428 /* i_blocks represent file system block size */
4429 return i_blocks
<< (inode
->i_blkbits
- 9);
4434 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4438 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4440 struct ext4_iloc iloc
;
4441 struct ext4_inode
*raw_inode
;
4442 struct ext4_inode_info
*ei
;
4443 struct buffer_head
*bh
;
4444 struct inode
*inode
;
4448 inode
= iget_locked(sb
, ino
);
4450 return ERR_PTR(-ENOMEM
);
4451 if (!(inode
->i_state
& I_NEW
))
4455 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4456 ei
->i_acl
= EXT4_ACL_NOT_CACHED
;
4457 ei
->i_default_acl
= EXT4_ACL_NOT_CACHED
;
4460 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4464 raw_inode
= ext4_raw_inode(&iloc
);
4465 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4466 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4467 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4468 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4469 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4470 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4472 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4475 ei
->i_dir_start_lookup
= 0;
4476 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4477 /* We now have enough fields to check if the inode was active or not.
4478 * This is needed because nfsd might try to access dead inodes
4479 * the test is that same one that e2fsck uses
4480 * NeilBrown 1999oct15
4482 if (inode
->i_nlink
== 0) {
4483 if (inode
->i_mode
== 0 ||
4484 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4485 /* this inode is deleted */
4490 /* The only unlinked inodes we let through here have
4491 * valid i_mode and are being read by the orphan
4492 * recovery code: that's fine, we're about to complete
4493 * the process of deleting those. */
4495 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4496 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4497 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4498 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
4500 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4501 inode
->i_size
= ext4_isize(raw_inode
);
4502 ei
->i_disksize
= inode
->i_size
;
4503 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4504 ei
->i_block_group
= iloc
.block_group
;
4505 ei
->i_last_alloc_group
= ~0;
4507 * NOTE! The in-memory inode i_data array is in little-endian order
4508 * even on big-endian machines: we do NOT byteswap the block numbers!
4510 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4511 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4512 INIT_LIST_HEAD(&ei
->i_orphan
);
4514 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4515 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4516 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4517 EXT4_INODE_SIZE(inode
->i_sb
)) {
4522 if (ei
->i_extra_isize
== 0) {
4523 /* The extra space is currently unused. Use it. */
4524 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4525 EXT4_GOOD_OLD_INODE_SIZE
;
4527 __le32
*magic
= (void *)raw_inode
+
4528 EXT4_GOOD_OLD_INODE_SIZE
+
4530 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4531 ei
->i_state
|= EXT4_STATE_XATTR
;
4534 ei
->i_extra_isize
= 0;
4536 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4537 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4538 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4539 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4541 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4542 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4543 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4545 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4549 if (ei
->i_file_acl
&&
4551 (le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
) +
4552 EXT4_SB(sb
)->s_gdb_count
)) ||
4553 (ei
->i_file_acl
>= ext4_blocks_count(EXT4_SB(sb
)->s_es
)))) {
4554 ext4_error(sb
, __func__
,
4555 "bad extended attribute block %llu in inode #%lu",
4556 ei
->i_file_acl
, inode
->i_ino
);
4559 } else if (ei
->i_flags
& EXT4_EXTENTS_FL
) {
4560 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4561 (S_ISLNK(inode
->i_mode
) &&
4562 !ext4_inode_is_fast_symlink(inode
)))
4563 /* Validate extent which is part of inode */
4564 ret
= ext4_ext_check_inode(inode
);
4565 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4566 (S_ISLNK(inode
->i_mode
) &&
4567 !ext4_inode_is_fast_symlink(inode
))) {
4568 /* Validate block references which are part of inode */
4569 ret
= ext4_check_inode_blockref(inode
);
4576 if (S_ISREG(inode
->i_mode
)) {
4577 inode
->i_op
= &ext4_file_inode_operations
;
4578 inode
->i_fop
= &ext4_file_operations
;
4579 ext4_set_aops(inode
);
4580 } else if (S_ISDIR(inode
->i_mode
)) {
4581 inode
->i_op
= &ext4_dir_inode_operations
;
4582 inode
->i_fop
= &ext4_dir_operations
;
4583 } else if (S_ISLNK(inode
->i_mode
)) {
4584 if (ext4_inode_is_fast_symlink(inode
)) {
4585 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4586 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4587 sizeof(ei
->i_data
) - 1);
4589 inode
->i_op
= &ext4_symlink_inode_operations
;
4590 ext4_set_aops(inode
);
4592 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
4593 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
4594 inode
->i_op
= &ext4_special_inode_operations
;
4595 if (raw_inode
->i_block
[0])
4596 init_special_inode(inode
, inode
->i_mode
,
4597 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4599 init_special_inode(inode
, inode
->i_mode
,
4600 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4604 ext4_error(inode
->i_sb
, __func__
,
4605 "bogus i_mode (%o) for inode=%lu",
4606 inode
->i_mode
, inode
->i_ino
);
4610 ext4_set_inode_flags(inode
);
4611 unlock_new_inode(inode
);
4616 return ERR_PTR(ret
);
4619 static int ext4_inode_blocks_set(handle_t
*handle
,
4620 struct ext4_inode
*raw_inode
,
4621 struct ext4_inode_info
*ei
)
4623 struct inode
*inode
= &(ei
->vfs_inode
);
4624 u64 i_blocks
= inode
->i_blocks
;
4625 struct super_block
*sb
= inode
->i_sb
;
4627 if (i_blocks
<= ~0U) {
4629 * i_blocks can be represnted in a 32 bit variable
4630 * as multiple of 512 bytes
4632 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4633 raw_inode
->i_blocks_high
= 0;
4634 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4637 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
4640 if (i_blocks
<= 0xffffffffffffULL
) {
4642 * i_blocks can be represented in a 48 bit variable
4643 * as multiple of 512 bytes
4645 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4646 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4647 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4649 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
4650 /* i_block is stored in file system block size */
4651 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
4652 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4653 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4659 * Post the struct inode info into an on-disk inode location in the
4660 * buffer-cache. This gobbles the caller's reference to the
4661 * buffer_head in the inode location struct.
4663 * The caller must have write access to iloc->bh.
4665 static int ext4_do_update_inode(handle_t
*handle
,
4666 struct inode
*inode
,
4667 struct ext4_iloc
*iloc
)
4669 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
4670 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4671 struct buffer_head
*bh
= iloc
->bh
;
4672 int err
= 0, rc
, block
;
4674 /* For fields not not tracking in the in-memory inode,
4675 * initialise them to zero for new inodes. */
4676 if (ei
->i_state
& EXT4_STATE_NEW
)
4677 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
4679 ext4_get_inode_flags(ei
);
4680 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
4681 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4682 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
4683 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
4685 * Fix up interoperability with old kernels. Otherwise, old inodes get
4686 * re-used with the upper 16 bits of the uid/gid intact
4689 raw_inode
->i_uid_high
=
4690 cpu_to_le16(high_16_bits(inode
->i_uid
));
4691 raw_inode
->i_gid_high
=
4692 cpu_to_le16(high_16_bits(inode
->i_gid
));
4694 raw_inode
->i_uid_high
= 0;
4695 raw_inode
->i_gid_high
= 0;
4698 raw_inode
->i_uid_low
=
4699 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
4700 raw_inode
->i_gid_low
=
4701 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
4702 raw_inode
->i_uid_high
= 0;
4703 raw_inode
->i_gid_high
= 0;
4705 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
4707 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
4708 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
4709 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
4710 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
4712 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
4714 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
4715 /* clear the migrate flag in the raw_inode */
4716 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
& ~EXT4_EXT_MIGRATE
);
4717 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
4718 cpu_to_le32(EXT4_OS_HURD
))
4719 raw_inode
->i_file_acl_high
=
4720 cpu_to_le16(ei
->i_file_acl
>> 32);
4721 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
4722 ext4_isize_set(raw_inode
, ei
->i_disksize
);
4723 if (ei
->i_disksize
> 0x7fffffffULL
) {
4724 struct super_block
*sb
= inode
->i_sb
;
4725 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4726 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
4727 EXT4_SB(sb
)->s_es
->s_rev_level
==
4728 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
4729 /* If this is the first large file
4730 * created, add a flag to the superblock.
4732 err
= ext4_journal_get_write_access(handle
,
4733 EXT4_SB(sb
)->s_sbh
);
4736 ext4_update_dynamic_rev(sb
);
4737 EXT4_SET_RO_COMPAT_FEATURE(sb
,
4738 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
4740 ext4_handle_sync(handle
);
4741 err
= ext4_handle_dirty_metadata(handle
, inode
,
4742 EXT4_SB(sb
)->s_sbh
);
4745 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
4746 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
4747 if (old_valid_dev(inode
->i_rdev
)) {
4748 raw_inode
->i_block
[0] =
4749 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
4750 raw_inode
->i_block
[1] = 0;
4752 raw_inode
->i_block
[0] = 0;
4753 raw_inode
->i_block
[1] =
4754 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
4755 raw_inode
->i_block
[2] = 0;
4757 } else for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4758 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
4760 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
4761 if (ei
->i_extra_isize
) {
4762 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4763 raw_inode
->i_version_hi
=
4764 cpu_to_le32(inode
->i_version
>> 32);
4765 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
4768 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4769 rc
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
4772 ei
->i_state
&= ~EXT4_STATE_NEW
;
4776 ext4_std_error(inode
->i_sb
, err
);
4781 * ext4_write_inode()
4783 * We are called from a few places:
4785 * - Within generic_file_write() for O_SYNC files.
4786 * Here, there will be no transaction running. We wait for any running
4787 * trasnaction to commit.
4789 * - Within sys_sync(), kupdate and such.
4790 * We wait on commit, if tol to.
4792 * - Within prune_icache() (PF_MEMALLOC == true)
4793 * Here we simply return. We can't afford to block kswapd on the
4796 * In all cases it is actually safe for us to return without doing anything,
4797 * because the inode has been copied into a raw inode buffer in
4798 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4801 * Note that we are absolutely dependent upon all inode dirtiers doing the
4802 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4803 * which we are interested.
4805 * It would be a bug for them to not do this. The code:
4807 * mark_inode_dirty(inode)
4809 * inode->i_size = expr;
4811 * is in error because a kswapd-driven write_inode() could occur while
4812 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4813 * will no longer be on the superblock's dirty inode list.
4815 int ext4_write_inode(struct inode
*inode
, int wait
)
4817 if (current
->flags
& PF_MEMALLOC
)
4820 if (ext4_journal_current_handle()) {
4821 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4829 return ext4_force_commit(inode
->i_sb
);
4835 * Called from notify_change.
4837 * We want to trap VFS attempts to truncate the file as soon as
4838 * possible. In particular, we want to make sure that when the VFS
4839 * shrinks i_size, we put the inode on the orphan list and modify
4840 * i_disksize immediately, so that during the subsequent flushing of
4841 * dirty pages and freeing of disk blocks, we can guarantee that any
4842 * commit will leave the blocks being flushed in an unused state on
4843 * disk. (On recovery, the inode will get truncated and the blocks will
4844 * be freed, so we have a strong guarantee that no future commit will
4845 * leave these blocks visible to the user.)
4847 * Another thing we have to assure is that if we are in ordered mode
4848 * and inode is still attached to the committing transaction, we must
4849 * we start writeout of all the dirty pages which are being truncated.
4850 * This way we are sure that all the data written in the previous
4851 * transaction are already on disk (truncate waits for pages under
4854 * Called with inode->i_mutex down.
4856 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
4858 struct inode
*inode
= dentry
->d_inode
;
4860 const unsigned int ia_valid
= attr
->ia_valid
;
4862 error
= inode_change_ok(inode
, attr
);
4866 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
4867 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
4870 /* (user+group)*(old+new) structure, inode write (sb,
4871 * inode block, ? - but truncate inode update has it) */
4872 handle
= ext4_journal_start(inode
, 2*(EXT4_QUOTA_INIT_BLOCKS(inode
->i_sb
)+
4873 EXT4_QUOTA_DEL_BLOCKS(inode
->i_sb
))+3);
4874 if (IS_ERR(handle
)) {
4875 error
= PTR_ERR(handle
);
4878 error
= vfs_dq_transfer(inode
, attr
) ? -EDQUOT
: 0;
4880 ext4_journal_stop(handle
);
4883 /* Update corresponding info in inode so that everything is in
4884 * one transaction */
4885 if (attr
->ia_valid
& ATTR_UID
)
4886 inode
->i_uid
= attr
->ia_uid
;
4887 if (attr
->ia_valid
& ATTR_GID
)
4888 inode
->i_gid
= attr
->ia_gid
;
4889 error
= ext4_mark_inode_dirty(handle
, inode
);
4890 ext4_journal_stop(handle
);
4893 if (attr
->ia_valid
& ATTR_SIZE
) {
4894 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
4895 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
4897 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
4904 if (S_ISREG(inode
->i_mode
) &&
4905 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
4908 handle
= ext4_journal_start(inode
, 3);
4909 if (IS_ERR(handle
)) {
4910 error
= PTR_ERR(handle
);
4914 error
= ext4_orphan_add(handle
, inode
);
4915 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
4916 rc
= ext4_mark_inode_dirty(handle
, inode
);
4919 ext4_journal_stop(handle
);
4921 if (ext4_should_order_data(inode
)) {
4922 error
= ext4_begin_ordered_truncate(inode
,
4925 /* Do as much error cleanup as possible */
4926 handle
= ext4_journal_start(inode
, 3);
4927 if (IS_ERR(handle
)) {
4928 ext4_orphan_del(NULL
, inode
);
4931 ext4_orphan_del(handle
, inode
);
4932 ext4_journal_stop(handle
);
4938 rc
= inode_setattr(inode
, attr
);
4940 /* If inode_setattr's call to ext4_truncate failed to get a
4941 * transaction handle at all, we need to clean up the in-core
4942 * orphan list manually. */
4944 ext4_orphan_del(NULL
, inode
);
4946 if (!rc
&& (ia_valid
& ATTR_MODE
))
4947 rc
= ext4_acl_chmod(inode
);
4950 ext4_std_error(inode
->i_sb
, error
);
4956 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
4959 struct inode
*inode
;
4960 unsigned long delalloc_blocks
;
4962 inode
= dentry
->d_inode
;
4963 generic_fillattr(inode
, stat
);
4966 * We can't update i_blocks if the block allocation is delayed
4967 * otherwise in the case of system crash before the real block
4968 * allocation is done, we will have i_blocks inconsistent with
4969 * on-disk file blocks.
4970 * We always keep i_blocks updated together with real
4971 * allocation. But to not confuse with user, stat
4972 * will return the blocks that include the delayed allocation
4973 * blocks for this file.
4975 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
4976 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
4977 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
4979 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
4983 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
4988 /* if nrblocks are contiguous */
4991 * With N contiguous data blocks, it need at most
4992 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
4993 * 2 dindirect blocks
4996 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4997 return indirects
+ 3;
5000 * if nrblocks are not contiguous, worse case, each block touch
5001 * a indirect block, and each indirect block touch a double indirect
5002 * block, plus a triple indirect block
5004 indirects
= nrblocks
* 2 + 1;
5008 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5010 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
5011 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
5012 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
5016 * Account for index blocks, block groups bitmaps and block group
5017 * descriptor blocks if modify datablocks and index blocks
5018 * worse case, the indexs blocks spread over different block groups
5020 * If datablocks are discontiguous, they are possible to spread over
5021 * different block groups too. If they are contiugous, with flexbg,
5022 * they could still across block group boundary.
5024 * Also account for superblock, inode, quota and xattr blocks
5026 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5028 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
5034 * How many index blocks need to touch to modify nrblocks?
5035 * The "Chunk" flag indicating whether the nrblocks is
5036 * physically contiguous on disk
5038 * For Direct IO and fallocate, they calls get_block to allocate
5039 * one single extent at a time, so they could set the "Chunk" flag
5041 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
5046 * Now let's see how many group bitmaps and group descriptors need
5056 if (groups
> ngroups
)
5058 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
5059 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
5061 /* bitmaps and block group descriptor blocks */
5062 ret
+= groups
+ gdpblocks
;
5064 /* Blocks for super block, inode, quota and xattr blocks */
5065 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
5071 * Calulate the total number of credits to reserve to fit
5072 * the modification of a single pages into a single transaction,
5073 * which may include multiple chunks of block allocations.
5075 * This could be called via ext4_write_begin()
5077 * We need to consider the worse case, when
5078 * one new block per extent.
5080 int ext4_writepage_trans_blocks(struct inode
*inode
)
5082 int bpp
= ext4_journal_blocks_per_page(inode
);
5085 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
5087 /* Account for data blocks for journalled mode */
5088 if (ext4_should_journal_data(inode
))
5094 * Calculate the journal credits for a chunk of data modification.
5096 * This is called from DIO, fallocate or whoever calling
5097 * ext4_get_blocks() to map/allocate a chunk of contigous disk blocks.
5099 * journal buffers for data blocks are not included here, as DIO
5100 * and fallocate do no need to journal data buffers.
5102 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
5104 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
5108 * The caller must have previously called ext4_reserve_inode_write().
5109 * Give this, we know that the caller already has write access to iloc->bh.
5111 int ext4_mark_iloc_dirty(handle_t
*handle
,
5112 struct inode
*inode
, struct ext4_iloc
*iloc
)
5116 if (test_opt(inode
->i_sb
, I_VERSION
))
5117 inode_inc_iversion(inode
);
5119 /* the do_update_inode consumes one bh->b_count */
5122 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5123 err
= ext4_do_update_inode(handle
, inode
, iloc
);
5129 * On success, We end up with an outstanding reference count against
5130 * iloc->bh. This _must_ be cleaned up later.
5134 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
5135 struct ext4_iloc
*iloc
)
5139 err
= ext4_get_inode_loc(inode
, iloc
);
5141 BUFFER_TRACE(iloc
->bh
, "get_write_access");
5142 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
5148 ext4_std_error(inode
->i_sb
, err
);
5153 * Expand an inode by new_extra_isize bytes.
5154 * Returns 0 on success or negative error number on failure.
5156 static int ext4_expand_extra_isize(struct inode
*inode
,
5157 unsigned int new_extra_isize
,
5158 struct ext4_iloc iloc
,
5161 struct ext4_inode
*raw_inode
;
5162 struct ext4_xattr_ibody_header
*header
;
5163 struct ext4_xattr_entry
*entry
;
5165 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
5168 raw_inode
= ext4_raw_inode(&iloc
);
5170 header
= IHDR(inode
, raw_inode
);
5171 entry
= IFIRST(header
);
5173 /* No extended attributes present */
5174 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
5175 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
5176 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5178 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5182 /* try to expand with EAs present */
5183 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5188 * What we do here is to mark the in-core inode as clean with respect to inode
5189 * dirtiness (it may still be data-dirty).
5190 * This means that the in-core inode may be reaped by prune_icache
5191 * without having to perform any I/O. This is a very good thing,
5192 * because *any* task may call prune_icache - even ones which
5193 * have a transaction open against a different journal.
5195 * Is this cheating? Not really. Sure, we haven't written the
5196 * inode out, but prune_icache isn't a user-visible syncing function.
5197 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5198 * we start and wait on commits.
5200 * Is this efficient/effective? Well, we're being nice to the system
5201 * by cleaning up our inodes proactively so they can be reaped
5202 * without I/O. But we are potentially leaving up to five seconds'
5203 * worth of inodes floating about which prune_icache wants us to
5204 * write out. One way to fix that would be to get prune_icache()
5205 * to do a write_super() to free up some memory. It has the desired
5208 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5210 struct ext4_iloc iloc
;
5211 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5212 static unsigned int mnt_count
;
5216 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5217 if (ext4_handle_valid(handle
) &&
5218 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5219 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
5221 * We need extra buffer credits since we may write into EA block
5222 * with this same handle. If journal_extend fails, then it will
5223 * only result in a minor loss of functionality for that inode.
5224 * If this is felt to be critical, then e2fsck should be run to
5225 * force a large enough s_min_extra_isize.
5227 if ((jbd2_journal_extend(handle
,
5228 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5229 ret
= ext4_expand_extra_isize(inode
,
5230 sbi
->s_want_extra_isize
,
5233 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
5235 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5236 ext4_warning(inode
->i_sb
, __func__
,
5237 "Unable to expand inode %lu. Delete"
5238 " some EAs or run e2fsck.",
5241 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5247 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5252 * ext4_dirty_inode() is called from __mark_inode_dirty()
5254 * We're really interested in the case where a file is being extended.
5255 * i_size has been changed by generic_commit_write() and we thus need
5256 * to include the updated inode in the current transaction.
5258 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
5259 * are allocated to the file.
5261 * If the inode is marked synchronous, we don't honour that here - doing
5262 * so would cause a commit on atime updates, which we don't bother doing.
5263 * We handle synchronous inodes at the highest possible level.
5265 void ext4_dirty_inode(struct inode
*inode
)
5267 handle_t
*current_handle
= ext4_journal_current_handle();
5270 if (!ext4_handle_valid(current_handle
)) {
5271 ext4_mark_inode_dirty(current_handle
, inode
);
5275 handle
= ext4_journal_start(inode
, 2);
5278 if (current_handle
&&
5279 current_handle
->h_transaction
!= handle
->h_transaction
) {
5280 /* This task has a transaction open against a different fs */
5281 printk(KERN_EMERG
"%s: transactions do not match!\n",
5284 jbd_debug(5, "marking dirty. outer handle=%p\n",
5286 ext4_mark_inode_dirty(handle
, inode
);
5288 ext4_journal_stop(handle
);
5295 * Bind an inode's backing buffer_head into this transaction, to prevent
5296 * it from being flushed to disk early. Unlike
5297 * ext4_reserve_inode_write, this leaves behind no bh reference and
5298 * returns no iloc structure, so the caller needs to repeat the iloc
5299 * lookup to mark the inode dirty later.
5301 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5303 struct ext4_iloc iloc
;
5307 err
= ext4_get_inode_loc(inode
, &iloc
);
5309 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5310 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5312 err
= ext4_handle_dirty_metadata(handle
,
5318 ext4_std_error(inode
->i_sb
, err
);
5323 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5330 * We have to be very careful here: changing a data block's
5331 * journaling status dynamically is dangerous. If we write a
5332 * data block to the journal, change the status and then delete
5333 * that block, we risk forgetting to revoke the old log record
5334 * from the journal and so a subsequent replay can corrupt data.
5335 * So, first we make sure that the journal is empty and that
5336 * nobody is changing anything.
5339 journal
= EXT4_JOURNAL(inode
);
5342 if (is_journal_aborted(journal
))
5345 jbd2_journal_lock_updates(journal
);
5346 jbd2_journal_flush(journal
);
5349 * OK, there are no updates running now, and all cached data is
5350 * synced to disk. We are now in a completely consistent state
5351 * which doesn't have anything in the journal, and we know that
5352 * no filesystem updates are running, so it is safe to modify
5353 * the inode's in-core data-journaling state flag now.
5357 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
5359 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
5360 ext4_set_aops(inode
);
5362 jbd2_journal_unlock_updates(journal
);
5364 /* Finally we can mark the inode as dirty. */
5366 handle
= ext4_journal_start(inode
, 1);
5368 return PTR_ERR(handle
);
5370 err
= ext4_mark_inode_dirty(handle
, inode
);
5371 ext4_handle_sync(handle
);
5372 ext4_journal_stop(handle
);
5373 ext4_std_error(inode
->i_sb
, err
);
5378 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5380 return !buffer_mapped(bh
);
5383 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5385 struct page
*page
= vmf
->page
;
5390 struct file
*file
= vma
->vm_file
;
5391 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5392 struct address_space
*mapping
= inode
->i_mapping
;
5395 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5396 * get i_mutex because we are already holding mmap_sem.
5398 down_read(&inode
->i_alloc_sem
);
5399 size
= i_size_read(inode
);
5400 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5401 || !PageUptodate(page
)) {
5402 /* page got truncated from under us? */
5406 if (PageMappedToDisk(page
))
5409 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5410 len
= size
& ~PAGE_CACHE_MASK
;
5412 len
= PAGE_CACHE_SIZE
;
5414 if (page_has_buffers(page
)) {
5415 /* return if we have all the buffers mapped */
5416 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5421 * OK, we need to fill the hole... Do write_begin write_end
5422 * to do block allocation/reservation.We are not holding
5423 * inode.i__mutex here. That allow * parallel write_begin,
5424 * write_end call. lock_page prevent this from happening
5425 * on the same page though
5427 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5428 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5431 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5432 len
, len
, page
, fsdata
);
5438 ret
= VM_FAULT_SIGBUS
;
5439 up_read(&inode
->i_alloc_sem
);