2 * linux/fs/ext4/inode.c
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
11 * linux/fs/minix/inode.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
15 * Goal-directed block allocation by Stephen Tweedie
16 * (sct@redhat.com), 1993, 1998
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 * 64-bit file support on 64-bit platforms by Jakub Jelinek
20 * (jj@sunsite.ms.mff.cuni.cz)
22 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
25 #include <linux/module.h>
27 #include <linux/time.h>
28 #include <linux/jbd2.h>
29 #include <linux/highuid.h>
30 #include <linux/pagemap.h>
31 #include <linux/quotaops.h>
32 #include <linux/string.h>
33 #include <linux/buffer_head.h>
34 #include <linux/writeback.h>
35 #include <linux/pagevec.h>
36 #include <linux/mpage.h>
37 #include <linux/namei.h>
38 #include <linux/uio.h>
39 #include <linux/bio.h>
40 #include "ext4_jbd2.h"
43 #include "ext4_extents.h"
45 #define MPAGE_DA_EXTENT_TAIL 0x01
47 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
50 return jbd2_journal_begin_ordered_truncate(&EXT4_I(inode
)->jinode
,
54 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
57 * Test whether an inode is a fast symlink.
59 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
61 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
62 (inode
->i_sb
->s_blocksize
>> 9) : 0;
64 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
68 * The ext4 forget function must perform a revoke if we are freeing data
69 * which has been journaled. Metadata (eg. indirect blocks) must be
70 * revoked in all cases.
72 * "bh" may be NULL: a metadata block may have been freed from memory
73 * but there may still be a record of it in the journal, and that record
74 * still needs to be revoked.
76 int ext4_forget(handle_t
*handle
, int is_metadata
, struct inode
*inode
,
77 struct buffer_head
*bh
, ext4_fsblk_t blocknr
)
83 BUFFER_TRACE(bh
, "enter");
85 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
87 bh
, is_metadata
, inode
->i_mode
,
88 test_opt(inode
->i_sb
, DATA_FLAGS
));
90 /* Never use the revoke function if we are doing full data
91 * journaling: there is no need to, and a V1 superblock won't
92 * support it. Otherwise, only skip the revoke on un-journaled
95 if (test_opt(inode
->i_sb
, DATA_FLAGS
) == EXT4_MOUNT_JOURNAL_DATA
||
96 (!is_metadata
&& !ext4_should_journal_data(inode
))) {
98 BUFFER_TRACE(bh
, "call jbd2_journal_forget");
99 return ext4_journal_forget(handle
, bh
);
105 * data!=journal && (is_metadata || should_journal_data(inode))
107 BUFFER_TRACE(bh
, "call ext4_journal_revoke");
108 err
= ext4_journal_revoke(handle
, blocknr
, bh
);
110 ext4_abort(inode
->i_sb
, __func__
,
111 "error %d when attempting revoke", err
);
112 BUFFER_TRACE(bh
, "exit");
117 * Work out how many blocks we need to proceed with the next chunk of a
118 * truncate transaction.
120 static unsigned long blocks_for_truncate(struct inode
*inode
)
124 needed
= inode
->i_blocks
>> (inode
->i_sb
->s_blocksize_bits
- 9);
126 /* Give ourselves just enough room to cope with inodes in which
127 * i_blocks is corrupt: we've seen disk corruptions in the past
128 * which resulted in random data in an inode which looked enough
129 * like a regular file for ext4 to try to delete it. Things
130 * will go a bit crazy if that happens, but at least we should
131 * try not to panic the whole kernel. */
135 /* But we need to bound the transaction so we don't overflow the
137 if (needed
> EXT4_MAX_TRANS_DATA
)
138 needed
= EXT4_MAX_TRANS_DATA
;
140 return EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + needed
;
144 * Truncate transactions can be complex and absolutely huge. So we need to
145 * be able to restart the transaction at a conventient checkpoint to make
146 * sure we don't overflow the journal.
148 * start_transaction gets us a new handle for a truncate transaction,
149 * and extend_transaction tries to extend the existing one a bit. If
150 * extend fails, we need to propagate the failure up and restart the
151 * transaction in the top-level truncate loop. --sct
153 static handle_t
*start_transaction(struct inode
*inode
)
157 result
= ext4_journal_start(inode
, blocks_for_truncate(inode
));
161 ext4_std_error(inode
->i_sb
, PTR_ERR(result
));
166 * Try to extend this transaction for the purposes of truncation.
168 * Returns 0 if we managed to create more room. If we can't create more
169 * room, and the transaction must be restarted we return 1.
171 static int try_to_extend_transaction(handle_t
*handle
, struct inode
*inode
)
173 if (handle
->h_buffer_credits
> EXT4_RESERVE_TRANS_BLOCKS
)
175 if (!ext4_journal_extend(handle
, blocks_for_truncate(inode
)))
181 * Restart the transaction associated with *handle. This does a commit,
182 * so before we call here everything must be consistently dirtied against
185 static int ext4_journal_test_restart(handle_t
*handle
, struct inode
*inode
)
187 jbd_debug(2, "restarting handle %p\n", handle
);
188 return ext4_journal_restart(handle
, blocks_for_truncate(inode
));
192 * Called at the last iput() if i_nlink is zero.
194 void ext4_delete_inode(struct inode
*inode
)
199 if (ext4_should_order_data(inode
))
200 ext4_begin_ordered_truncate(inode
, 0);
201 truncate_inode_pages(&inode
->i_data
, 0);
203 if (is_bad_inode(inode
))
206 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
207 if (IS_ERR(handle
)) {
208 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
210 * If we're going to skip the normal cleanup, we still need to
211 * make sure that the in-core orphan linked list is properly
214 ext4_orphan_del(NULL
, inode
);
221 err
= ext4_mark_inode_dirty(handle
, inode
);
223 ext4_warning(inode
->i_sb
, __func__
,
224 "couldn't mark inode dirty (err %d)", err
);
228 ext4_truncate(inode
);
231 * ext4_ext_truncate() doesn't reserve any slop when it
232 * restarts journal transactions; therefore there may not be
233 * enough credits left in the handle to remove the inode from
234 * the orphan list and set the dtime field.
236 if (handle
->h_buffer_credits
< 3) {
237 err
= ext4_journal_extend(handle
, 3);
239 err
= ext4_journal_restart(handle
, 3);
241 ext4_warning(inode
->i_sb
, __func__
,
242 "couldn't extend journal (err %d)", err
);
244 ext4_journal_stop(handle
);
250 * Kill off the orphan record which ext4_truncate created.
251 * AKPM: I think this can be inside the above `if'.
252 * Note that ext4_orphan_del() has to be able to cope with the
253 * deletion of a non-existent orphan - this is because we don't
254 * know if ext4_truncate() actually created an orphan record.
255 * (Well, we could do this if we need to, but heck - it works)
257 ext4_orphan_del(handle
, inode
);
258 EXT4_I(inode
)->i_dtime
= get_seconds();
261 * One subtle ordering requirement: if anything has gone wrong
262 * (transaction abort, IO errors, whatever), then we can still
263 * do these next steps (the fs will already have been marked as
264 * having errors), but we can't free the inode if the mark_dirty
267 if (ext4_mark_inode_dirty(handle
, inode
))
268 /* If that failed, just do the required in-core inode clear. */
271 ext4_free_inode(handle
, inode
);
272 ext4_journal_stop(handle
);
275 clear_inode(inode
); /* We must guarantee clearing of inode... */
281 struct buffer_head
*bh
;
284 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
286 p
->key
= *(p
->p
= v
);
291 * ext4_block_to_path - parse the block number into array of offsets
292 * @inode: inode in question (we are only interested in its superblock)
293 * @i_block: block number to be parsed
294 * @offsets: array to store the offsets in
295 * @boundary: set this non-zero if the referred-to block is likely to be
296 * followed (on disk) by an indirect block.
298 * To store the locations of file's data ext4 uses a data structure common
299 * for UNIX filesystems - tree of pointers anchored in the inode, with
300 * data blocks at leaves and indirect blocks in intermediate nodes.
301 * This function translates the block number into path in that tree -
302 * return value is the path length and @offsets[n] is the offset of
303 * pointer to (n+1)th node in the nth one. If @block is out of range
304 * (negative or too large) warning is printed and zero returned.
306 * Note: function doesn't find node addresses, so no IO is needed. All
307 * we need to know is the capacity of indirect blocks (taken from the
312 * Portability note: the last comparison (check that we fit into triple
313 * indirect block) is spelled differently, because otherwise on an
314 * architecture with 32-bit longs and 8Kb pages we might get into trouble
315 * if our filesystem had 8Kb blocks. We might use long long, but that would
316 * kill us on x86. Oh, well, at least the sign propagation does not matter -
317 * i_block would have to be negative in the very beginning, so we would not
321 static int ext4_block_to_path(struct inode
*inode
,
323 ext4_lblk_t offsets
[4], int *boundary
)
325 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
326 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
327 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
328 indirect_blocks
= ptrs
,
329 double_blocks
= (1 << (ptrs_bits
* 2));
334 ext4_warning(inode
->i_sb
, "ext4_block_to_path", "block < 0");
335 } else if (i_block
< direct_blocks
) {
336 offsets
[n
++] = i_block
;
337 final
= direct_blocks
;
338 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
339 offsets
[n
++] = EXT4_IND_BLOCK
;
340 offsets
[n
++] = i_block
;
342 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
343 offsets
[n
++] = EXT4_DIND_BLOCK
;
344 offsets
[n
++] = i_block
>> ptrs_bits
;
345 offsets
[n
++] = i_block
& (ptrs
- 1);
347 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
348 offsets
[n
++] = EXT4_TIND_BLOCK
;
349 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
350 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
351 offsets
[n
++] = i_block
& (ptrs
- 1);
354 ext4_warning(inode
->i_sb
, "ext4_block_to_path",
356 i_block
+ direct_blocks
+
357 indirect_blocks
+ double_blocks
);
360 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
365 * ext4_get_branch - read the chain of indirect blocks leading to data
366 * @inode: inode in question
367 * @depth: depth of the chain (1 - direct pointer, etc.)
368 * @offsets: offsets of pointers in inode/indirect blocks
369 * @chain: place to store the result
370 * @err: here we store the error value
372 * Function fills the array of triples <key, p, bh> and returns %NULL
373 * if everything went OK or the pointer to the last filled triple
374 * (incomplete one) otherwise. Upon the return chain[i].key contains
375 * the number of (i+1)-th block in the chain (as it is stored in memory,
376 * i.e. little-endian 32-bit), chain[i].p contains the address of that
377 * number (it points into struct inode for i==0 and into the bh->b_data
378 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
379 * block for i>0 and NULL for i==0. In other words, it holds the block
380 * numbers of the chain, addresses they were taken from (and where we can
381 * verify that chain did not change) and buffer_heads hosting these
384 * Function stops when it stumbles upon zero pointer (absent block)
385 * (pointer to last triple returned, *@err == 0)
386 * or when it gets an IO error reading an indirect block
387 * (ditto, *@err == -EIO)
388 * or when it reads all @depth-1 indirect blocks successfully and finds
389 * the whole chain, all way to the data (returns %NULL, *err == 0).
391 * Need to be called with
392 * down_read(&EXT4_I(inode)->i_data_sem)
394 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
395 ext4_lblk_t
*offsets
,
396 Indirect chain
[4], int *err
)
398 struct super_block
*sb
= inode
->i_sb
;
400 struct buffer_head
*bh
;
403 /* i_data is not going away, no lock needed */
404 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
408 bh
= sb_bread(sb
, le32_to_cpu(p
->key
));
411 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
425 * ext4_find_near - find a place for allocation with sufficient locality
427 * @ind: descriptor of indirect block.
429 * This function returns the preferred place for block allocation.
430 * It is used when heuristic for sequential allocation fails.
432 * + if there is a block to the left of our position - allocate near it.
433 * + if pointer will live in indirect block - allocate near that block.
434 * + if pointer will live in inode - allocate in the same
437 * In the latter case we colour the starting block by the callers PID to
438 * prevent it from clashing with concurrent allocations for a different inode
439 * in the same block group. The PID is used here so that functionally related
440 * files will be close-by on-disk.
442 * Caller must make sure that @ind is valid and will stay that way.
444 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
446 struct ext4_inode_info
*ei
= EXT4_I(inode
);
447 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
449 ext4_fsblk_t bg_start
;
450 ext4_fsblk_t last_block
;
451 ext4_grpblk_t colour
;
453 /* Try to find previous block */
454 for (p
= ind
->p
- 1; p
>= start
; p
--) {
456 return le32_to_cpu(*p
);
459 /* No such thing, so let's try location of indirect block */
461 return ind
->bh
->b_blocknr
;
464 * It is going to be referred to from the inode itself? OK, just put it
465 * into the same cylinder group then.
467 bg_start
= ext4_group_first_block_no(inode
->i_sb
, ei
->i_block_group
);
468 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
470 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
471 colour
= (current
->pid
% 16) *
472 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
474 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
475 return bg_start
+ colour
;
479 * ext4_find_goal - find a preferred place for allocation.
481 * @block: block we want
482 * @partial: pointer to the last triple within a chain
484 * Normally this function find the preferred place for block allocation,
487 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
491 * XXX need to get goal block from mballoc's data structures
494 return ext4_find_near(inode
, partial
);
498 * ext4_blks_to_allocate: Look up the block map and count the number
499 * of direct blocks need to be allocated for the given branch.
501 * @branch: chain of indirect blocks
502 * @k: number of blocks need for indirect blocks
503 * @blks: number of data blocks to be mapped.
504 * @blocks_to_boundary: the offset in the indirect block
506 * return the total number of blocks to be allocate, including the
507 * direct and indirect blocks.
509 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned long blks
,
510 int blocks_to_boundary
)
512 unsigned long count
= 0;
515 * Simple case, [t,d]Indirect block(s) has not allocated yet
516 * then it's clear blocks on that path have not allocated
519 /* right now we don't handle cross boundary allocation */
520 if (blks
< blocks_to_boundary
+ 1)
523 count
+= blocks_to_boundary
+ 1;
528 while (count
< blks
&& count
<= blocks_to_boundary
&&
529 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
536 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
537 * @indirect_blks: the number of blocks need to allocate for indirect
540 * @new_blocks: on return it will store the new block numbers for
541 * the indirect blocks(if needed) and the first direct block,
542 * @blks: on return it will store the total number of allocated
545 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
546 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
547 int indirect_blks
, int blks
,
548 ext4_fsblk_t new_blocks
[4], int *err
)
550 struct ext4_allocation_request ar
;
552 unsigned long count
= 0, blk_allocated
= 0;
554 ext4_fsblk_t current_block
= 0;
558 * Here we try to allocate the requested multiple blocks at once,
559 * on a best-effort basis.
560 * To build a branch, we should allocate blocks for
561 * the indirect blocks(if not allocated yet), and at least
562 * the first direct block of this branch. That's the
563 * minimum number of blocks need to allocate(required)
565 /* first we try to allocate the indirect blocks */
566 target
= indirect_blks
;
569 /* allocating blocks for indirect blocks and direct blocks */
570 current_block
= ext4_new_meta_blocks(handle
, inode
,
576 /* allocate blocks for indirect blocks */
577 while (index
< indirect_blks
&& count
) {
578 new_blocks
[index
++] = current_block
++;
583 * save the new block number
584 * for the first direct block
586 new_blocks
[index
] = current_block
;
587 printk(KERN_INFO
"%s returned more blocks than "
588 "requested\n", __func__
);
594 target
= blks
- count
;
595 blk_allocated
= count
;
598 /* Now allocate data blocks */
599 memset(&ar
, 0, sizeof(ar
));
604 if (S_ISREG(inode
->i_mode
))
605 /* enable in-core preallocation only for regular files */
606 ar
.flags
= EXT4_MB_HINT_DATA
;
608 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
610 if (*err
&& (target
== blks
)) {
612 * if the allocation failed and we didn't allocate
618 if (target
== blks
) {
620 * save the new block number
621 * for the first direct block
623 new_blocks
[index
] = current_block
;
625 blk_allocated
+= ar
.len
;
628 /* total number of blocks allocated for direct blocks */
633 for (i
= 0; i
< index
; i
++)
634 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
639 * ext4_alloc_branch - allocate and set up a chain of blocks.
641 * @indirect_blks: number of allocated indirect blocks
642 * @blks: number of allocated direct blocks
643 * @offsets: offsets (in the blocks) to store the pointers to next.
644 * @branch: place to store the chain in.
646 * This function allocates blocks, zeroes out all but the last one,
647 * links them into chain and (if we are synchronous) writes them to disk.
648 * In other words, it prepares a branch that can be spliced onto the
649 * inode. It stores the information about that chain in the branch[], in
650 * the same format as ext4_get_branch() would do. We are calling it after
651 * we had read the existing part of chain and partial points to the last
652 * triple of that (one with zero ->key). Upon the exit we have the same
653 * picture as after the successful ext4_get_block(), except that in one
654 * place chain is disconnected - *branch->p is still zero (we did not
655 * set the last link), but branch->key contains the number that should
656 * be placed into *branch->p to fill that gap.
658 * If allocation fails we free all blocks we've allocated (and forget
659 * their buffer_heads) and return the error value the from failed
660 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
661 * as described above and return 0.
663 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
664 ext4_lblk_t iblock
, int indirect_blks
,
665 int *blks
, ext4_fsblk_t goal
,
666 ext4_lblk_t
*offsets
, Indirect
*branch
)
668 int blocksize
= inode
->i_sb
->s_blocksize
;
671 struct buffer_head
*bh
;
673 ext4_fsblk_t new_blocks
[4];
674 ext4_fsblk_t current_block
;
676 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
677 *blks
, new_blocks
, &err
);
681 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
683 * metadata blocks and data blocks are allocated.
685 for (n
= 1; n
<= indirect_blks
; n
++) {
687 * Get buffer_head for parent block, zero it out
688 * and set the pointer to new one, then send
691 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
694 BUFFER_TRACE(bh
, "call get_create_access");
695 err
= ext4_journal_get_create_access(handle
, bh
);
702 memset(bh
->b_data
, 0, blocksize
);
703 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
704 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
705 *branch
[n
].p
= branch
[n
].key
;
706 if (n
== indirect_blks
) {
707 current_block
= new_blocks
[n
];
709 * End of chain, update the last new metablock of
710 * the chain to point to the new allocated
711 * data blocks numbers
713 for (i
=1; i
< num
; i
++)
714 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
716 BUFFER_TRACE(bh
, "marking uptodate");
717 set_buffer_uptodate(bh
);
720 BUFFER_TRACE(bh
, "call ext4_journal_dirty_metadata");
721 err
= ext4_journal_dirty_metadata(handle
, bh
);
728 /* Allocation failed, free what we already allocated */
729 for (i
= 1; i
<= n
; i
++) {
730 BUFFER_TRACE(branch
[i
].bh
, "call jbd2_journal_forget");
731 ext4_journal_forget(handle
, branch
[i
].bh
);
733 for (i
= 0; i
< indirect_blks
; i
++)
734 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
736 ext4_free_blocks(handle
, inode
, new_blocks
[i
], num
, 0);
742 * ext4_splice_branch - splice the allocated branch onto inode.
744 * @block: (logical) number of block we are adding
745 * @chain: chain of indirect blocks (with a missing link - see
747 * @where: location of missing link
748 * @num: number of indirect blocks we are adding
749 * @blks: number of direct blocks we are adding
751 * This function fills the missing link and does all housekeeping needed in
752 * inode (->i_blocks, etc.). In case of success we end up with the full
753 * chain to new block and return 0.
755 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
756 ext4_lblk_t block
, Indirect
*where
, int num
, int blks
)
760 ext4_fsblk_t current_block
;
763 * If we're splicing into a [td]indirect block (as opposed to the
764 * inode) then we need to get write access to the [td]indirect block
768 BUFFER_TRACE(where
->bh
, "get_write_access");
769 err
= ext4_journal_get_write_access(handle
, where
->bh
);
775 *where
->p
= where
->key
;
778 * Update the host buffer_head or inode to point to more just allocated
779 * direct blocks blocks
781 if (num
== 0 && blks
> 1) {
782 current_block
= le32_to_cpu(where
->key
) + 1;
783 for (i
= 1; i
< blks
; i
++)
784 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
787 /* We are done with atomic stuff, now do the rest of housekeeping */
789 inode
->i_ctime
= ext4_current_time(inode
);
790 ext4_mark_inode_dirty(handle
, inode
);
792 /* had we spliced it onto indirect block? */
795 * If we spliced it onto an indirect block, we haven't
796 * altered the inode. Note however that if it is being spliced
797 * onto an indirect block at the very end of the file (the
798 * file is growing) then we *will* alter the inode to reflect
799 * the new i_size. But that is not done here - it is done in
800 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
802 jbd_debug(5, "splicing indirect only\n");
803 BUFFER_TRACE(where
->bh
, "call ext4_journal_dirty_metadata");
804 err
= ext4_journal_dirty_metadata(handle
, where
->bh
);
809 * OK, we spliced it into the inode itself on a direct block.
810 * Inode was dirtied above.
812 jbd_debug(5, "splicing direct\n");
817 for (i
= 1; i
<= num
; i
++) {
818 BUFFER_TRACE(where
[i
].bh
, "call jbd2_journal_forget");
819 ext4_journal_forget(handle
, where
[i
].bh
);
820 ext4_free_blocks(handle
, inode
,
821 le32_to_cpu(where
[i
-1].key
), 1, 0);
823 ext4_free_blocks(handle
, inode
, le32_to_cpu(where
[num
].key
), blks
, 0);
829 * Allocation strategy is simple: if we have to allocate something, we will
830 * have to go the whole way to leaf. So let's do it before attaching anything
831 * to tree, set linkage between the newborn blocks, write them if sync is
832 * required, recheck the path, free and repeat if check fails, otherwise
833 * set the last missing link (that will protect us from any truncate-generated
834 * removals - all blocks on the path are immune now) and possibly force the
835 * write on the parent block.
836 * That has a nice additional property: no special recovery from the failed
837 * allocations is needed - we simply release blocks and do not touch anything
838 * reachable from inode.
840 * `handle' can be NULL if create == 0.
842 * return > 0, # of blocks mapped or allocated.
843 * return = 0, if plain lookup failed.
844 * return < 0, error case.
847 * Need to be called with
848 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
849 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
851 int ext4_get_blocks_handle(handle_t
*handle
, struct inode
*inode
,
852 ext4_lblk_t iblock
, unsigned long maxblocks
,
853 struct buffer_head
*bh_result
,
854 int create
, int extend_disksize
)
857 ext4_lblk_t offsets
[4];
862 int blocks_to_boundary
= 0;
864 struct ext4_inode_info
*ei
= EXT4_I(inode
);
866 ext4_fsblk_t first_block
= 0;
870 J_ASSERT(!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
));
871 J_ASSERT(handle
!= NULL
|| create
== 0);
872 depth
= ext4_block_to_path(inode
, iblock
, offsets
,
873 &blocks_to_boundary
);
878 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
880 /* Simplest case - block found, no allocation needed */
882 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
883 clear_buffer_new(bh_result
);
886 while (count
< maxblocks
&& count
<= blocks_to_boundary
) {
889 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
891 if (blk
== first_block
+ count
)
899 /* Next simple case - plain lookup or failed read of indirect block */
900 if (!create
|| err
== -EIO
)
904 * Okay, we need to do block allocation.
906 goal
= ext4_find_goal(inode
, iblock
, partial
);
908 /* the number of blocks need to allocate for [d,t]indirect blocks */
909 indirect_blks
= (chain
+ depth
) - partial
- 1;
912 * Next look up the indirect map to count the totoal number of
913 * direct blocks to allocate for this branch.
915 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
916 maxblocks
, blocks_to_boundary
);
918 * Block out ext4_truncate while we alter the tree
920 err
= ext4_alloc_branch(handle
, inode
, iblock
, indirect_blks
,
922 offsets
+ (partial
- chain
), partial
);
925 * The ext4_splice_branch call will free and forget any buffers
926 * on the new chain if there is a failure, but that risks using
927 * up transaction credits, especially for bitmaps where the
928 * credits cannot be returned. Can we handle this somehow? We
929 * may need to return -EAGAIN upwards in the worst case. --sct
932 err
= ext4_splice_branch(handle
, inode
, iblock
,
933 partial
, indirect_blks
, count
);
935 * i_disksize growing is protected by i_data_sem. Don't forget to
936 * protect it if you're about to implement concurrent
937 * ext4_get_block() -bzzz
939 if (!err
&& extend_disksize
) {
940 disksize
= ((loff_t
) iblock
+ count
) << inode
->i_blkbits
;
941 if (disksize
> i_size_read(inode
))
942 disksize
= i_size_read(inode
);
943 if (disksize
> ei
->i_disksize
)
944 ei
->i_disksize
= disksize
;
949 set_buffer_new(bh_result
);
951 map_bh(bh_result
, inode
->i_sb
, le32_to_cpu(chain
[depth
-1].key
));
952 if (count
> blocks_to_boundary
)
953 set_buffer_boundary(bh_result
);
955 /* Clean up and exit */
956 partial
= chain
+ depth
- 1; /* the whole chain */
958 while (partial
> chain
) {
959 BUFFER_TRACE(partial
->bh
, "call brelse");
963 BUFFER_TRACE(bh_result
, "returned");
969 * Calculate the number of metadata blocks need to reserve
970 * to allocate @blocks for non extent file based file
972 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
, int blocks
)
974 int icap
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
975 int ind_blks
, dind_blks
, tind_blks
;
977 /* number of new indirect blocks needed */
978 ind_blks
= (blocks
+ icap
- 1) / icap
;
980 dind_blks
= (ind_blks
+ icap
- 1) / icap
;
984 return ind_blks
+ dind_blks
+ tind_blks
;
988 * Calculate the number of metadata blocks need to reserve
989 * to allocate given number of blocks
991 static int ext4_calc_metadata_amount(struct inode
*inode
, int blocks
)
996 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
997 return ext4_ext_calc_metadata_amount(inode
, blocks
);
999 return ext4_indirect_calc_metadata_amount(inode
, blocks
);
1002 static void ext4_da_update_reserve_space(struct inode
*inode
, int used
)
1004 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1005 int total
, mdb
, mdb_free
;
1007 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1008 /* recalculate the number of metablocks still need to be reserved */
1009 total
= EXT4_I(inode
)->i_reserved_data_blocks
- used
;
1010 mdb
= ext4_calc_metadata_amount(inode
, total
);
1012 /* figure out how many metablocks to release */
1013 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1014 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1017 /* Account for allocated meta_blocks */
1018 mdb_free
-= EXT4_I(inode
)->i_allocated_meta_blocks
;
1020 /* update fs dirty blocks counter */
1021 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1022 EXT4_I(inode
)->i_allocated_meta_blocks
= 0;
1023 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1026 /* update per-inode reservations */
1027 BUG_ON(used
> EXT4_I(inode
)->i_reserved_data_blocks
);
1028 EXT4_I(inode
)->i_reserved_data_blocks
-= used
;
1030 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1034 * The ext4_get_blocks_wrap() function try to look up the requested blocks,
1035 * and returns if the blocks are already mapped.
1037 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1038 * and store the allocated blocks in the result buffer head and mark it
1041 * If file type is extents based, it will call ext4_ext_get_blocks(),
1042 * Otherwise, call with ext4_get_blocks_handle() to handle indirect mapping
1045 * On success, it returns the number of blocks being mapped or allocate.
1046 * if create==0 and the blocks are pre-allocated and uninitialized block,
1047 * the result buffer head is unmapped. If the create ==1, it will make sure
1048 * the buffer head is mapped.
1050 * It returns 0 if plain look up failed (blocks have not been allocated), in
1051 * that casem, buffer head is unmapped
1053 * It returns the error in case of allocation failure.
1055 int ext4_get_blocks_wrap(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1056 unsigned long max_blocks
, struct buffer_head
*bh
,
1057 int create
, int extend_disksize
, int flag
)
1061 clear_buffer_mapped(bh
);
1064 * Try to see if we can get the block without requesting
1065 * for new file system block.
1067 down_read((&EXT4_I(inode
)->i_data_sem
));
1068 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1069 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1072 retval
= ext4_get_blocks_handle(handle
,
1073 inode
, block
, max_blocks
, bh
, 0, 0);
1075 up_read((&EXT4_I(inode
)->i_data_sem
));
1077 /* If it is only a block(s) look up */
1082 * Returns if the blocks have already allocated
1084 * Note that if blocks have been preallocated
1085 * ext4_ext_get_block() returns th create = 0
1086 * with buffer head unmapped.
1088 if (retval
> 0 && buffer_mapped(bh
))
1092 * New blocks allocate and/or writing to uninitialized extent
1093 * will possibly result in updating i_data, so we take
1094 * the write lock of i_data_sem, and call get_blocks()
1095 * with create == 1 flag.
1097 down_write((&EXT4_I(inode
)->i_data_sem
));
1100 * if the caller is from delayed allocation writeout path
1101 * we have already reserved fs blocks for allocation
1102 * let the underlying get_block() function know to
1103 * avoid double accounting
1106 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1108 * We need to check for EXT4 here because migrate
1109 * could have changed the inode type in between
1111 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1112 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1113 bh
, create
, extend_disksize
);
1115 retval
= ext4_get_blocks_handle(handle
, inode
, block
,
1116 max_blocks
, bh
, create
, extend_disksize
);
1118 if (retval
> 0 && buffer_new(bh
)) {
1120 * We allocated new blocks which will result in
1121 * i_data's format changing. Force the migrate
1122 * to fail by clearing migrate flags
1124 EXT4_I(inode
)->i_flags
= EXT4_I(inode
)->i_flags
&
1130 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1132 * Update reserved blocks/metadata blocks
1133 * after successful block allocation
1134 * which were deferred till now
1136 if ((retval
> 0) && buffer_delay(bh
))
1137 ext4_da_update_reserve_space(inode
, retval
);
1140 up_write((&EXT4_I(inode
)->i_data_sem
));
1144 /* Maximum number of blocks we map for direct IO at once. */
1145 #define DIO_MAX_BLOCKS 4096
1147 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1148 struct buffer_head
*bh_result
, int create
)
1150 handle_t
*handle
= ext4_journal_current_handle();
1151 int ret
= 0, started
= 0;
1152 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1155 if (create
&& !handle
) {
1156 /* Direct IO write... */
1157 if (max_blocks
> DIO_MAX_BLOCKS
)
1158 max_blocks
= DIO_MAX_BLOCKS
;
1159 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1160 handle
= ext4_journal_start(inode
, dio_credits
);
1161 if (IS_ERR(handle
)) {
1162 ret
= PTR_ERR(handle
);
1168 ret
= ext4_get_blocks_wrap(handle
, inode
, iblock
,
1169 max_blocks
, bh_result
, create
, 0, 0);
1171 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1175 ext4_journal_stop(handle
);
1181 * `handle' can be NULL if create is zero
1183 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1184 ext4_lblk_t block
, int create
, int *errp
)
1186 struct buffer_head dummy
;
1189 J_ASSERT(handle
!= NULL
|| create
== 0);
1192 dummy
.b_blocknr
= -1000;
1193 buffer_trace_init(&dummy
.b_history
);
1194 err
= ext4_get_blocks_wrap(handle
, inode
, block
, 1,
1195 &dummy
, create
, 1, 0);
1197 * ext4_get_blocks_handle() returns number of blocks
1198 * mapped. 0 in case of a HOLE.
1206 if (!err
&& buffer_mapped(&dummy
)) {
1207 struct buffer_head
*bh
;
1208 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1213 if (buffer_new(&dummy
)) {
1214 J_ASSERT(create
!= 0);
1215 J_ASSERT(handle
!= NULL
);
1218 * Now that we do not always journal data, we should
1219 * keep in mind whether this should always journal the
1220 * new buffer as metadata. For now, regular file
1221 * writes use ext4_get_block instead, so it's not a
1225 BUFFER_TRACE(bh
, "call get_create_access");
1226 fatal
= ext4_journal_get_create_access(handle
, bh
);
1227 if (!fatal
&& !buffer_uptodate(bh
)) {
1228 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1229 set_buffer_uptodate(bh
);
1232 BUFFER_TRACE(bh
, "call ext4_journal_dirty_metadata");
1233 err
= ext4_journal_dirty_metadata(handle
, bh
);
1237 BUFFER_TRACE(bh
, "not a new buffer");
1250 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1251 ext4_lblk_t block
, int create
, int *err
)
1253 struct buffer_head
*bh
;
1255 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1258 if (buffer_uptodate(bh
))
1260 ll_rw_block(READ_META
, 1, &bh
);
1262 if (buffer_uptodate(bh
))
1269 static int walk_page_buffers(handle_t
*handle
,
1270 struct buffer_head
*head
,
1274 int (*fn
)(handle_t
*handle
,
1275 struct buffer_head
*bh
))
1277 struct buffer_head
*bh
;
1278 unsigned block_start
, block_end
;
1279 unsigned blocksize
= head
->b_size
;
1281 struct buffer_head
*next
;
1283 for (bh
= head
, block_start
= 0;
1284 ret
== 0 && (bh
!= head
|| !block_start
);
1285 block_start
= block_end
, bh
= next
)
1287 next
= bh
->b_this_page
;
1288 block_end
= block_start
+ blocksize
;
1289 if (block_end
<= from
|| block_start
>= to
) {
1290 if (partial
&& !buffer_uptodate(bh
))
1294 err
= (*fn
)(handle
, bh
);
1302 * To preserve ordering, it is essential that the hole instantiation and
1303 * the data write be encapsulated in a single transaction. We cannot
1304 * close off a transaction and start a new one between the ext4_get_block()
1305 * and the commit_write(). So doing the jbd2_journal_start at the start of
1306 * prepare_write() is the right place.
1308 * Also, this function can nest inside ext4_writepage() ->
1309 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1310 * has generated enough buffer credits to do the whole page. So we won't
1311 * block on the journal in that case, which is good, because the caller may
1314 * By accident, ext4 can be reentered when a transaction is open via
1315 * quota file writes. If we were to commit the transaction while thus
1316 * reentered, there can be a deadlock - we would be holding a quota
1317 * lock, and the commit would never complete if another thread had a
1318 * transaction open and was blocking on the quota lock - a ranking
1321 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1322 * will _not_ run commit under these circumstances because handle->h_ref
1323 * is elevated. We'll still have enough credits for the tiny quotafile
1326 static int do_journal_get_write_access(handle_t
*handle
,
1327 struct buffer_head
*bh
)
1329 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1331 return ext4_journal_get_write_access(handle
, bh
);
1334 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1335 loff_t pos
, unsigned len
, unsigned flags
,
1336 struct page
**pagep
, void **fsdata
)
1338 struct inode
*inode
= mapping
->host
;
1339 int ret
, needed_blocks
= ext4_writepage_trans_blocks(inode
);
1346 index
= pos
>> PAGE_CACHE_SHIFT
;
1347 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1351 handle
= ext4_journal_start(inode
, needed_blocks
);
1352 if (IS_ERR(handle
)) {
1353 ret
= PTR_ERR(handle
);
1357 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1359 ext4_journal_stop(handle
);
1365 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1368 if (!ret
&& ext4_should_journal_data(inode
)) {
1369 ret
= walk_page_buffers(handle
, page_buffers(page
),
1370 from
, to
, NULL
, do_journal_get_write_access
);
1375 ext4_journal_stop(handle
);
1376 page_cache_release(page
);
1378 * block_write_begin may have instantiated a few blocks
1379 * outside i_size. Trim these off again. Don't need
1380 * i_size_read because we hold i_mutex.
1382 if (pos
+ len
> inode
->i_size
)
1383 vmtruncate(inode
, inode
->i_size
);
1386 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1392 /* For write_end() in data=journal mode */
1393 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1395 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1397 set_buffer_uptodate(bh
);
1398 return ext4_journal_dirty_metadata(handle
, bh
);
1402 * We need to pick up the new inode size which generic_commit_write gave us
1403 * `file' can be NULL - eg, when called from page_symlink().
1405 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1406 * buffers are managed internally.
1408 static int ext4_ordered_write_end(struct file
*file
,
1409 struct address_space
*mapping
,
1410 loff_t pos
, unsigned len
, unsigned copied
,
1411 struct page
*page
, void *fsdata
)
1413 handle_t
*handle
= ext4_journal_current_handle();
1414 struct inode
*inode
= mapping
->host
;
1417 ret
= ext4_jbd2_file_inode(handle
, inode
);
1422 new_i_size
= pos
+ copied
;
1423 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1424 ext4_update_i_disksize(inode
, new_i_size
);
1425 /* We need to mark inode dirty even if
1426 * new_i_size is less that inode->i_size
1427 * bu greater than i_disksize.(hint delalloc)
1429 ext4_mark_inode_dirty(handle
, inode
);
1432 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
1438 ret2
= ext4_journal_stop(handle
);
1442 return ret
? ret
: copied
;
1445 static int ext4_writeback_write_end(struct file
*file
,
1446 struct address_space
*mapping
,
1447 loff_t pos
, unsigned len
, unsigned copied
,
1448 struct page
*page
, void *fsdata
)
1450 handle_t
*handle
= ext4_journal_current_handle();
1451 struct inode
*inode
= mapping
->host
;
1455 new_i_size
= pos
+ copied
;
1456 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1457 ext4_update_i_disksize(inode
, new_i_size
);
1458 /* We need to mark inode dirty even if
1459 * new_i_size is less that inode->i_size
1460 * bu greater than i_disksize.(hint delalloc)
1462 ext4_mark_inode_dirty(handle
, inode
);
1465 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
1471 ret2
= ext4_journal_stop(handle
);
1475 return ret
? ret
: copied
;
1478 static int ext4_journalled_write_end(struct file
*file
,
1479 struct address_space
*mapping
,
1480 loff_t pos
, unsigned len
, unsigned copied
,
1481 struct page
*page
, void *fsdata
)
1483 handle_t
*handle
= ext4_journal_current_handle();
1484 struct inode
*inode
= mapping
->host
;
1490 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1494 if (!PageUptodate(page
))
1496 page_zero_new_buffers(page
, from
+copied
, to
);
1499 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1500 to
, &partial
, write_end_fn
);
1502 SetPageUptodate(page
);
1503 new_i_size
= pos
+ copied
;
1504 if (new_i_size
> inode
->i_size
)
1505 i_size_write(inode
, pos
+copied
);
1506 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1507 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1508 ext4_update_i_disksize(inode
, new_i_size
);
1509 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1515 ret2
= ext4_journal_stop(handle
);
1518 page_cache_release(page
);
1520 return ret
? ret
: copied
;
1523 static int ext4_da_reserve_space(struct inode
*inode
, int nrblocks
)
1526 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1527 unsigned long md_needed
, mdblocks
, total
= 0;
1530 * recalculate the amount of metadata blocks to reserve
1531 * in order to allocate nrblocks
1532 * worse case is one extent per block
1535 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1536 total
= EXT4_I(inode
)->i_reserved_data_blocks
+ nrblocks
;
1537 mdblocks
= ext4_calc_metadata_amount(inode
, total
);
1538 BUG_ON(mdblocks
< EXT4_I(inode
)->i_reserved_meta_blocks
);
1540 md_needed
= mdblocks
- EXT4_I(inode
)->i_reserved_meta_blocks
;
1541 total
= md_needed
+ nrblocks
;
1543 if (ext4_claim_free_blocks(sbi
, total
)) {
1544 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1545 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1551 EXT4_I(inode
)->i_reserved_data_blocks
+= nrblocks
;
1552 EXT4_I(inode
)->i_reserved_meta_blocks
= mdblocks
;
1554 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1555 return 0; /* success */
1558 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1560 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1561 int total
, mdb
, mdb_free
, release
;
1564 return; /* Nothing to release, exit */
1566 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1568 if (!EXT4_I(inode
)->i_reserved_data_blocks
) {
1570 * if there is no reserved blocks, but we try to free some
1571 * then the counter is messed up somewhere.
1572 * but since this function is called from invalidate
1573 * page, it's harmless to return without any action
1575 printk(KERN_INFO
"ext4 delalloc try to release %d reserved "
1576 "blocks for inode %lu, but there is no reserved "
1577 "data blocks\n", to_free
, inode
->i_ino
);
1578 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1582 /* recalculate the number of metablocks still need to be reserved */
1583 total
= EXT4_I(inode
)->i_reserved_data_blocks
- to_free
;
1584 mdb
= ext4_calc_metadata_amount(inode
, total
);
1586 /* figure out how many metablocks to release */
1587 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1588 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1590 release
= to_free
+ mdb_free
;
1592 /* update fs dirty blocks counter for truncate case */
1593 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, release
);
1595 /* update per-inode reservations */
1596 BUG_ON(to_free
> EXT4_I(inode
)->i_reserved_data_blocks
);
1597 EXT4_I(inode
)->i_reserved_data_blocks
-= to_free
;
1599 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1600 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1601 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1604 static void ext4_da_page_release_reservation(struct page
*page
,
1605 unsigned long offset
)
1608 struct buffer_head
*head
, *bh
;
1609 unsigned int curr_off
= 0;
1611 head
= page_buffers(page
);
1614 unsigned int next_off
= curr_off
+ bh
->b_size
;
1616 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1618 clear_buffer_delay(bh
);
1620 curr_off
= next_off
;
1621 } while ((bh
= bh
->b_this_page
) != head
);
1622 ext4_da_release_space(page
->mapping
->host
, to_release
);
1626 * Delayed allocation stuff
1629 struct mpage_da_data
{
1630 struct inode
*inode
;
1631 struct buffer_head lbh
; /* extent of blocks */
1632 unsigned long first_page
, next_page
; /* extent of pages */
1633 get_block_t
*get_block
;
1634 struct writeback_control
*wbc
;
1641 * mpage_da_submit_io - walks through extent of pages and try to write
1642 * them with writepage() call back
1644 * @mpd->inode: inode
1645 * @mpd->first_page: first page of the extent
1646 * @mpd->next_page: page after the last page of the extent
1647 * @mpd->get_block: the filesystem's block mapper function
1649 * By the time mpage_da_submit_io() is called we expect all blocks
1650 * to be allocated. this may be wrong if allocation failed.
1652 * As pages are already locked by write_cache_pages(), we can't use it
1654 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1656 struct address_space
*mapping
= mpd
->inode
->i_mapping
;
1657 int ret
= 0, err
, nr_pages
, i
;
1658 unsigned long index
, end
;
1659 struct pagevec pvec
;
1662 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1663 pagevec_init(&pvec
, 0);
1664 index
= mpd
->first_page
;
1665 end
= mpd
->next_page
- 1;
1667 while (index
<= end
) {
1669 * We can use PAGECACHE_TAG_DIRTY lookup here because
1670 * even though we have cleared the dirty flag on the page
1671 * We still keep the page in the radix tree with tag
1672 * PAGECACHE_TAG_DIRTY. See clear_page_dirty_for_io.
1673 * The PAGECACHE_TAG_DIRTY is cleared in set_page_writeback
1674 * which is called via the below writepage callback.
1676 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1677 PAGECACHE_TAG_DIRTY
,
1679 (pgoff_t
)PAGEVEC_SIZE
-1) + 1);
1682 for (i
= 0; i
< nr_pages
; i
++) {
1683 struct page
*page
= pvec
.pages
[i
];
1685 pages_skipped
= mpd
->wbc
->pages_skipped
;
1686 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
1687 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
1689 * have successfully written the page
1690 * without skipping the same
1692 mpd
->pages_written
++;
1694 * In error case, we have to continue because
1695 * remaining pages are still locked
1696 * XXX: unlock and re-dirty them?
1701 pagevec_release(&pvec
);
1707 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
1709 * @mpd->inode - inode to walk through
1710 * @exbh->b_blocknr - first block on a disk
1711 * @exbh->b_size - amount of space in bytes
1712 * @logical - first logical block to start assignment with
1714 * the function goes through all passed space and put actual disk
1715 * block numbers into buffer heads, dropping BH_Delay
1717 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
1718 struct buffer_head
*exbh
)
1720 struct inode
*inode
= mpd
->inode
;
1721 struct address_space
*mapping
= inode
->i_mapping
;
1722 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
1723 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
1724 struct buffer_head
*head
, *bh
;
1726 struct pagevec pvec
;
1729 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1730 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1731 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1733 pagevec_init(&pvec
, 0);
1735 while (index
<= end
) {
1736 /* XXX: optimize tail */
1737 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1740 for (i
= 0; i
< nr_pages
; i
++) {
1741 struct page
*page
= pvec
.pages
[i
];
1743 index
= page
->index
;
1748 BUG_ON(!PageLocked(page
));
1749 BUG_ON(PageWriteback(page
));
1750 BUG_ON(!page_has_buffers(page
));
1752 bh
= page_buffers(page
);
1755 /* skip blocks out of the range */
1757 if (cur_logical
>= logical
)
1760 } while ((bh
= bh
->b_this_page
) != head
);
1763 if (cur_logical
>= logical
+ blocks
)
1765 if (buffer_delay(bh
)) {
1766 bh
->b_blocknr
= pblock
;
1767 clear_buffer_delay(bh
);
1768 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
1769 } else if (buffer_unwritten(bh
)) {
1770 bh
->b_blocknr
= pblock
;
1771 clear_buffer_unwritten(bh
);
1772 set_buffer_mapped(bh
);
1774 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
1775 } else if (buffer_mapped(bh
))
1776 BUG_ON(bh
->b_blocknr
!= pblock
);
1780 } while ((bh
= bh
->b_this_page
) != head
);
1782 pagevec_release(&pvec
);
1788 * __unmap_underlying_blocks - just a helper function to unmap
1789 * set of blocks described by @bh
1791 static inline void __unmap_underlying_blocks(struct inode
*inode
,
1792 struct buffer_head
*bh
)
1794 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
1797 blocks
= bh
->b_size
>> inode
->i_blkbits
;
1798 for (i
= 0; i
< blocks
; i
++)
1799 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
1802 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
1803 sector_t logical
, long blk_cnt
)
1807 struct pagevec pvec
;
1808 struct inode
*inode
= mpd
->inode
;
1809 struct address_space
*mapping
= inode
->i_mapping
;
1811 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1812 end
= (logical
+ blk_cnt
- 1) >>
1813 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
1814 while (index
<= end
) {
1815 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1818 for (i
= 0; i
< nr_pages
; i
++) {
1819 struct page
*page
= pvec
.pages
[i
];
1820 index
= page
->index
;
1825 BUG_ON(!PageLocked(page
));
1826 BUG_ON(PageWriteback(page
));
1827 block_invalidatepage(page
, 0);
1828 ClearPageUptodate(page
);
1835 static void ext4_print_free_blocks(struct inode
*inode
)
1837 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1838 printk(KERN_EMERG
"Total free blocks count %lld\n",
1839 ext4_count_free_blocks(inode
->i_sb
));
1840 printk(KERN_EMERG
"Free/Dirty block details\n");
1841 printk(KERN_EMERG
"free_blocks=%lld\n",
1842 (long long)percpu_counter_sum(&sbi
->s_freeblocks_counter
));
1843 printk(KERN_EMERG
"dirty_blocks=%lld\n",
1844 (long long)percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
1845 printk(KERN_EMERG
"Block reservation details\n");
1846 printk(KERN_EMERG
"i_reserved_data_blocks=%lu\n",
1847 EXT4_I(inode
)->i_reserved_data_blocks
);
1848 printk(KERN_EMERG
"i_reserved_meta_blocks=%lu\n",
1849 EXT4_I(inode
)->i_reserved_meta_blocks
);
1854 * mpage_da_map_blocks - go through given space
1856 * @mpd->lbh - bh describing space
1857 * @mpd->get_block - the filesystem's block mapper function
1859 * The function skips space we know is already mapped to disk blocks.
1862 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
1865 struct buffer_head
new;
1866 struct buffer_head
*lbh
= &mpd
->lbh
;
1870 * We consider only non-mapped and non-allocated blocks
1872 if (buffer_mapped(lbh
) && !buffer_delay(lbh
))
1874 new.b_state
= lbh
->b_state
;
1876 new.b_size
= lbh
->b_size
;
1877 next
= lbh
->b_blocknr
;
1879 * If we didn't accumulate anything
1880 * to write simply return
1884 err
= mpd
->get_block(mpd
->inode
, next
, &new, 1);
1887 /* If get block returns with error
1888 * we simply return. Later writepage
1889 * will redirty the page and writepages
1890 * will find the dirty page again
1895 if (err
== -ENOSPC
&&
1896 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
1902 * get block failure will cause us
1903 * to loop in writepages. Because
1904 * a_ops->writepage won't be able to
1905 * make progress. The page will be redirtied
1906 * by writepage and writepages will again
1907 * try to write the same.
1909 printk(KERN_EMERG
"%s block allocation failed for inode %lu "
1910 "at logical offset %llu with max blocks "
1911 "%zd with error %d\n",
1912 __func__
, mpd
->inode
->i_ino
,
1913 (unsigned long long)next
,
1914 lbh
->b_size
>> mpd
->inode
->i_blkbits
, err
);
1915 printk(KERN_EMERG
"This should not happen.!! "
1916 "Data will be lost\n");
1917 if (err
== -ENOSPC
) {
1918 ext4_print_free_blocks(mpd
->inode
);
1920 /* invlaidate all the pages */
1921 ext4_da_block_invalidatepages(mpd
, next
,
1922 lbh
->b_size
>> mpd
->inode
->i_blkbits
);
1925 BUG_ON(new.b_size
== 0);
1927 if (buffer_new(&new))
1928 __unmap_underlying_blocks(mpd
->inode
, &new);
1931 * If blocks are delayed marked, we need to
1932 * put actual blocknr and drop delayed bit
1934 if (buffer_delay(lbh
) || buffer_unwritten(lbh
))
1935 mpage_put_bnr_to_bhs(mpd
, next
, &new);
1940 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1941 (1 << BH_Delay) | (1 << BH_Unwritten))
1944 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1946 * @mpd->lbh - extent of blocks
1947 * @logical - logical number of the block in the file
1948 * @bh - bh of the block (used to access block's state)
1950 * the function is used to collect contig. blocks in same state
1952 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
1953 sector_t logical
, struct buffer_head
*bh
)
1956 size_t b_size
= bh
->b_size
;
1957 struct buffer_head
*lbh
= &mpd
->lbh
;
1958 int nrblocks
= lbh
->b_size
>> mpd
->inode
->i_blkbits
;
1960 /* check if thereserved journal credits might overflow */
1961 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
1962 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
1964 * With non-extent format we are limited by the journal
1965 * credit available. Total credit needed to insert
1966 * nrblocks contiguous blocks is dependent on the
1967 * nrblocks. So limit nrblocks.
1970 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
1971 EXT4_MAX_TRANS_DATA
) {
1973 * Adding the new buffer_head would make it cross the
1974 * allowed limit for which we have journal credit
1975 * reserved. So limit the new bh->b_size
1977 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
1978 mpd
->inode
->i_blkbits
;
1979 /* we will do mpage_da_submit_io in the next loop */
1983 * First block in the extent
1985 if (lbh
->b_size
== 0) {
1986 lbh
->b_blocknr
= logical
;
1987 lbh
->b_size
= b_size
;
1988 lbh
->b_state
= bh
->b_state
& BH_FLAGS
;
1992 next
= lbh
->b_blocknr
+ nrblocks
;
1994 * Can we merge the block to our big extent?
1996 if (logical
== next
&& (bh
->b_state
& BH_FLAGS
) == lbh
->b_state
) {
1997 lbh
->b_size
+= b_size
;
2003 * We couldn't merge the block to our extent, so we
2004 * need to flush current extent and start new one
2006 if (mpage_da_map_blocks(mpd
) == 0)
2007 mpage_da_submit_io(mpd
);
2013 * __mpage_da_writepage - finds extent of pages and blocks
2015 * @page: page to consider
2016 * @wbc: not used, we just follow rules
2019 * The function finds extents of pages and scan them for all blocks.
2021 static int __mpage_da_writepage(struct page
*page
,
2022 struct writeback_control
*wbc
, void *data
)
2024 struct mpage_da_data
*mpd
= data
;
2025 struct inode
*inode
= mpd
->inode
;
2026 struct buffer_head
*bh
, *head
, fake
;
2031 * Rest of the page in the page_vec
2032 * redirty then and skip then. We will
2033 * try to to write them again after
2034 * starting a new transaction
2036 redirty_page_for_writepage(wbc
, page
);
2038 return MPAGE_DA_EXTENT_TAIL
;
2041 * Can we merge this page to current extent?
2043 if (mpd
->next_page
!= page
->index
) {
2045 * Nope, we can't. So, we map non-allocated blocks
2046 * and start IO on them using writepage()
2048 if (mpd
->next_page
!= mpd
->first_page
) {
2049 if (mpage_da_map_blocks(mpd
) == 0)
2050 mpage_da_submit_io(mpd
);
2052 * skip rest of the page in the page_vec
2055 redirty_page_for_writepage(wbc
, page
);
2057 return MPAGE_DA_EXTENT_TAIL
;
2061 * Start next extent of pages ...
2063 mpd
->first_page
= page
->index
;
2068 mpd
->lbh
.b_size
= 0;
2069 mpd
->lbh
.b_state
= 0;
2070 mpd
->lbh
.b_blocknr
= 0;
2073 mpd
->next_page
= page
->index
+ 1;
2074 logical
= (sector_t
) page
->index
<<
2075 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2077 if (!page_has_buffers(page
)) {
2079 * There is no attached buffer heads yet (mmap?)
2080 * we treat the page asfull of dirty blocks
2083 bh
->b_size
= PAGE_CACHE_SIZE
;
2085 set_buffer_dirty(bh
);
2086 set_buffer_uptodate(bh
);
2087 mpage_add_bh_to_extent(mpd
, logical
, bh
);
2089 return MPAGE_DA_EXTENT_TAIL
;
2092 * Page with regular buffer heads, just add all dirty ones
2094 head
= page_buffers(page
);
2097 BUG_ON(buffer_locked(bh
));
2098 if (buffer_dirty(bh
) &&
2099 (!buffer_mapped(bh
) || buffer_delay(bh
))) {
2100 mpage_add_bh_to_extent(mpd
, logical
, bh
);
2102 return MPAGE_DA_EXTENT_TAIL
;
2105 } while ((bh
= bh
->b_this_page
) != head
);
2112 * mpage_da_writepages - walk the list of dirty pages of the given
2113 * address space, allocates non-allocated blocks, maps newly-allocated
2114 * blocks to existing bhs and issue IO them
2116 * @mapping: address space structure to write
2117 * @wbc: subtract the number of written pages from *@wbc->nr_to_write
2118 * @get_block: the filesystem's block mapper function.
2120 * This is a library function, which implements the writepages()
2121 * address_space_operation.
2123 static int mpage_da_writepages(struct address_space
*mapping
,
2124 struct writeback_control
*wbc
,
2125 struct mpage_da_data
*mpd
)
2129 if (!mpd
->get_block
)
2130 return generic_writepages(mapping
, wbc
);
2132 mpd
->lbh
.b_size
= 0;
2133 mpd
->lbh
.b_state
= 0;
2134 mpd
->lbh
.b_blocknr
= 0;
2135 mpd
->first_page
= 0;
2138 mpd
->pages_written
= 0;
2141 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
, mpd
);
2143 * Handle last extent of pages
2145 if (!mpd
->io_done
&& mpd
->next_page
!= mpd
->first_page
) {
2146 if (mpage_da_map_blocks(mpd
) == 0)
2147 mpage_da_submit_io(mpd
);
2150 ret
= MPAGE_DA_EXTENT_TAIL
;
2152 wbc
->nr_to_write
-= mpd
->pages_written
;
2157 * this is a special callback for ->write_begin() only
2158 * it's intention is to return mapped block or reserve space
2160 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2161 struct buffer_head
*bh_result
, int create
)
2165 BUG_ON(create
== 0);
2166 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2169 * first, we need to know whether the block is allocated already
2170 * preallocated blocks are unmapped but should treated
2171 * the same as allocated blocks.
2173 ret
= ext4_get_blocks_wrap(NULL
, inode
, iblock
, 1, bh_result
, 0, 0, 0);
2174 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2175 /* the block isn't (pre)allocated yet, let's reserve space */
2177 * XXX: __block_prepare_write() unmaps passed block,
2180 ret
= ext4_da_reserve_space(inode
, 1);
2182 /* not enough space to reserve */
2185 map_bh(bh_result
, inode
->i_sb
, 0);
2186 set_buffer_new(bh_result
);
2187 set_buffer_delay(bh_result
);
2188 } else if (ret
> 0) {
2189 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2195 #define EXT4_DELALLOC_RSVED 1
2196 static int ext4_da_get_block_write(struct inode
*inode
, sector_t iblock
,
2197 struct buffer_head
*bh_result
, int create
)
2200 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2201 loff_t disksize
= EXT4_I(inode
)->i_disksize
;
2202 handle_t
*handle
= NULL
;
2204 handle
= ext4_journal_current_handle();
2206 ret
= ext4_get_blocks_wrap(handle
, inode
, iblock
, max_blocks
,
2207 bh_result
, create
, 0, EXT4_DELALLOC_RSVED
);
2210 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2212 if (ext4_should_order_data(inode
)) {
2214 retval
= ext4_jbd2_file_inode(handle
, inode
);
2217 * Failed to add inode for ordered
2218 * mode. Don't update file size
2224 * Update on-disk size along with block allocation
2225 * we don't use 'extend_disksize' as size may change
2226 * within already allocated block -bzzz
2228 disksize
= ((loff_t
) iblock
+ ret
) << inode
->i_blkbits
;
2229 if (disksize
> i_size_read(inode
))
2230 disksize
= i_size_read(inode
);
2231 if (disksize
> EXT4_I(inode
)->i_disksize
) {
2232 ext4_update_i_disksize(inode
, disksize
);
2233 ret
= ext4_mark_inode_dirty(handle
, inode
);
2241 static int ext4_bh_unmapped_or_delay(handle_t
*handle
, struct buffer_head
*bh
)
2244 * unmapped buffer is possible for holes.
2245 * delay buffer is possible with delayed allocation
2247 return ((!buffer_mapped(bh
) || buffer_delay(bh
)) && buffer_dirty(bh
));
2250 static int ext4_normal_get_block_write(struct inode
*inode
, sector_t iblock
,
2251 struct buffer_head
*bh_result
, int create
)
2254 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2257 * we don't want to do block allocation in writepage
2258 * so call get_block_wrap with create = 0
2260 ret
= ext4_get_blocks_wrap(NULL
, inode
, iblock
, max_blocks
,
2261 bh_result
, 0, 0, 0);
2263 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2270 * get called vi ext4_da_writepages after taking page lock (have journal handle)
2271 * get called via journal_submit_inode_data_buffers (no journal handle)
2272 * get called via shrink_page_list via pdflush (no journal handle)
2273 * or grab_page_cache when doing write_begin (have journal handle)
2275 static int ext4_da_writepage(struct page
*page
,
2276 struct writeback_control
*wbc
)
2281 struct buffer_head
*page_bufs
;
2282 struct inode
*inode
= page
->mapping
->host
;
2284 size
= i_size_read(inode
);
2285 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2286 len
= size
& ~PAGE_CACHE_MASK
;
2288 len
= PAGE_CACHE_SIZE
;
2290 if (page_has_buffers(page
)) {
2291 page_bufs
= page_buffers(page
);
2292 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2293 ext4_bh_unmapped_or_delay
)) {
2295 * We don't want to do block allocation
2296 * So redirty the page and return
2297 * We may reach here when we do a journal commit
2298 * via journal_submit_inode_data_buffers.
2299 * If we don't have mapping block we just ignore
2300 * them. We can also reach here via shrink_page_list
2302 redirty_page_for_writepage(wbc
, page
);
2308 * The test for page_has_buffers() is subtle:
2309 * We know the page is dirty but it lost buffers. That means
2310 * that at some moment in time after write_begin()/write_end()
2311 * has been called all buffers have been clean and thus they
2312 * must have been written at least once. So they are all
2313 * mapped and we can happily proceed with mapping them
2314 * and writing the page.
2316 * Try to initialize the buffer_heads and check whether
2317 * all are mapped and non delay. We don't want to
2318 * do block allocation here.
2320 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
2321 ext4_normal_get_block_write
);
2323 page_bufs
= page_buffers(page
);
2324 /* check whether all are mapped and non delay */
2325 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2326 ext4_bh_unmapped_or_delay
)) {
2327 redirty_page_for_writepage(wbc
, page
);
2333 * We can't do block allocation here
2334 * so just redity the page and unlock
2337 redirty_page_for_writepage(wbc
, page
);
2341 /* now mark the buffer_heads as dirty and uptodate */
2342 block_commit_write(page
, 0, PAGE_CACHE_SIZE
);
2345 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2346 ret
= nobh_writepage(page
, ext4_normal_get_block_write
, wbc
);
2348 ret
= block_write_full_page(page
,
2349 ext4_normal_get_block_write
,
2356 * This is called via ext4_da_writepages() to
2357 * calulate the total number of credits to reserve to fit
2358 * a single extent allocation into a single transaction,
2359 * ext4_da_writpeages() will loop calling this before
2360 * the block allocation.
2363 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2365 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2368 * With non-extent format the journal credit needed to
2369 * insert nrblocks contiguous block is dependent on
2370 * number of contiguous block. So we will limit
2371 * number of contiguous block to a sane value
2373 if (!(inode
->i_flags
& EXT4_EXTENTS_FL
) &&
2374 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2375 max_blocks
= EXT4_MAX_TRANS_DATA
;
2377 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2380 static int ext4_da_writepages(struct address_space
*mapping
,
2381 struct writeback_control
*wbc
)
2384 int range_whole
= 0;
2385 handle_t
*handle
= NULL
;
2386 struct mpage_da_data mpd
;
2387 struct inode
*inode
= mapping
->host
;
2388 int no_nrwrite_index_update
;
2389 long pages_written
= 0, pages_skipped
;
2390 int needed_blocks
, ret
= 0, nr_to_writebump
= 0;
2391 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2394 * No pages to write? This is mainly a kludge to avoid starting
2395 * a transaction for special inodes like journal inode on last iput()
2396 * because that could violate lock ordering on umount
2398 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2402 * If the filesystem has aborted, it is read-only, so return
2403 * right away instead of dumping stack traces later on that
2404 * will obscure the real source of the problem. We test
2405 * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because
2406 * the latter could be true if the filesystem is mounted
2407 * read-only, and in that case, ext4_da_writepages should
2408 * *never* be called, so if that ever happens, we would want
2411 if (unlikely(sbi
->s_mount_opt
& EXT4_MOUNT_ABORT
))
2415 * Make sure nr_to_write is >= sbi->s_mb_stream_request
2416 * This make sure small files blocks are allocated in
2417 * single attempt. This ensure that small files
2418 * get less fragmented.
2420 if (wbc
->nr_to_write
< sbi
->s_mb_stream_request
) {
2421 nr_to_writebump
= sbi
->s_mb_stream_request
- wbc
->nr_to_write
;
2422 wbc
->nr_to_write
= sbi
->s_mb_stream_request
;
2424 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2427 if (wbc
->range_cyclic
)
2428 index
= mapping
->writeback_index
;
2430 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2433 mpd
.inode
= mapping
->host
;
2436 * we don't want write_cache_pages to update
2437 * nr_to_write and writeback_index
2439 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2440 wbc
->no_nrwrite_index_update
= 1;
2441 pages_skipped
= wbc
->pages_skipped
;
2443 while (!ret
&& wbc
->nr_to_write
> 0) {
2446 * we insert one extent at a time. So we need
2447 * credit needed for single extent allocation.
2448 * journalled mode is currently not supported
2451 BUG_ON(ext4_should_journal_data(inode
));
2452 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2454 /* start a new transaction*/
2455 handle
= ext4_journal_start(inode
, needed_blocks
);
2456 if (IS_ERR(handle
)) {
2457 ret
= PTR_ERR(handle
);
2458 printk(KERN_CRIT
"%s: jbd2_start: "
2459 "%ld pages, ino %lu; err %d\n", __func__
,
2460 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2462 goto out_writepages
;
2464 mpd
.get_block
= ext4_da_get_block_write
;
2465 ret
= mpage_da_writepages(mapping
, wbc
, &mpd
);
2467 ext4_journal_stop(handle
);
2469 if (mpd
.retval
== -ENOSPC
) {
2470 /* commit the transaction which would
2471 * free blocks released in the transaction
2474 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2475 wbc
->pages_skipped
= pages_skipped
;
2477 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2479 * got one extent now try with
2482 pages_written
+= mpd
.pages_written
;
2483 wbc
->pages_skipped
= pages_skipped
;
2485 } else if (wbc
->nr_to_write
)
2487 * There is no more writeout needed
2488 * or we requested for a noblocking writeout
2489 * and we found the device congested
2493 if (pages_skipped
!= wbc
->pages_skipped
)
2494 printk(KERN_EMERG
"This should not happen leaving %s "
2495 "with nr_to_write = %ld ret = %d\n",
2496 __func__
, wbc
->nr_to_write
, ret
);
2499 index
+= pages_written
;
2500 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2502 * set the writeback_index so that range_cyclic
2503 * mode will write it back later
2505 mapping
->writeback_index
= index
;
2508 if (!no_nrwrite_index_update
)
2509 wbc
->no_nrwrite_index_update
= 0;
2510 wbc
->nr_to_write
-= nr_to_writebump
;
2514 #define FALL_BACK_TO_NONDELALLOC 1
2515 static int ext4_nonda_switch(struct super_block
*sb
)
2517 s64 free_blocks
, dirty_blocks
;
2518 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2521 * switch to non delalloc mode if we are running low
2522 * on free block. The free block accounting via percpu
2523 * counters can get slightly wrong with FBC_BATCH getting
2524 * accumulated on each CPU without updating global counters
2525 * Delalloc need an accurate free block accounting. So switch
2526 * to non delalloc when we are near to error range.
2528 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
2529 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
2530 if (2 * free_blocks
< 3 * dirty_blocks
||
2531 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
2533 * free block count is less that 150% of dirty blocks
2534 * or free blocks is less that watermark
2541 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
2542 loff_t pos
, unsigned len
, unsigned flags
,
2543 struct page
**pagep
, void **fsdata
)
2545 int ret
, retries
= 0;
2549 struct inode
*inode
= mapping
->host
;
2552 index
= pos
>> PAGE_CACHE_SHIFT
;
2553 from
= pos
& (PAGE_CACHE_SIZE
- 1);
2556 if (ext4_nonda_switch(inode
->i_sb
)) {
2557 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
2558 return ext4_write_begin(file
, mapping
, pos
,
2559 len
, flags
, pagep
, fsdata
);
2561 *fsdata
= (void *)0;
2564 * With delayed allocation, we don't log the i_disksize update
2565 * if there is delayed block allocation. But we still need
2566 * to journalling the i_disksize update if writes to the end
2567 * of file which has an already mapped buffer.
2569 handle
= ext4_journal_start(inode
, 1);
2570 if (IS_ERR(handle
)) {
2571 ret
= PTR_ERR(handle
);
2575 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
2577 ext4_journal_stop(handle
);
2583 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
2584 ext4_da_get_block_prep
);
2587 ext4_journal_stop(handle
);
2588 page_cache_release(page
);
2590 * block_write_begin may have instantiated a few blocks
2591 * outside i_size. Trim these off again. Don't need
2592 * i_size_read because we hold i_mutex.
2594 if (pos
+ len
> inode
->i_size
)
2595 vmtruncate(inode
, inode
->i_size
);
2598 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
2605 * Check if we should update i_disksize
2606 * when write to the end of file but not require block allocation
2608 static int ext4_da_should_update_i_disksize(struct page
*page
,
2609 unsigned long offset
)
2611 struct buffer_head
*bh
;
2612 struct inode
*inode
= page
->mapping
->host
;
2616 bh
= page_buffers(page
);
2617 idx
= offset
>> inode
->i_blkbits
;
2619 for (i
= 0; i
< idx
; i
++)
2620 bh
= bh
->b_this_page
;
2622 if (!buffer_mapped(bh
) || (buffer_delay(bh
)))
2627 static int ext4_da_write_end(struct file
*file
,
2628 struct address_space
*mapping
,
2629 loff_t pos
, unsigned len
, unsigned copied
,
2630 struct page
*page
, void *fsdata
)
2632 struct inode
*inode
= mapping
->host
;
2634 handle_t
*handle
= ext4_journal_current_handle();
2636 unsigned long start
, end
;
2637 int write_mode
= (int)(unsigned long)fsdata
;
2639 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
2640 if (ext4_should_order_data(inode
)) {
2641 return ext4_ordered_write_end(file
, mapping
, pos
,
2642 len
, copied
, page
, fsdata
);
2643 } else if (ext4_should_writeback_data(inode
)) {
2644 return ext4_writeback_write_end(file
, mapping
, pos
,
2645 len
, copied
, page
, fsdata
);
2651 start
= pos
& (PAGE_CACHE_SIZE
- 1);
2652 end
= start
+ copied
- 1;
2655 * generic_write_end() will run mark_inode_dirty() if i_size
2656 * changes. So let's piggyback the i_disksize mark_inode_dirty
2660 new_i_size
= pos
+ copied
;
2661 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2662 if (ext4_da_should_update_i_disksize(page
, end
)) {
2663 down_write(&EXT4_I(inode
)->i_data_sem
);
2664 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
2666 * Updating i_disksize when extending file
2667 * without needing block allocation
2669 if (ext4_should_order_data(inode
))
2670 ret
= ext4_jbd2_file_inode(handle
,
2673 EXT4_I(inode
)->i_disksize
= new_i_size
;
2675 up_write(&EXT4_I(inode
)->i_data_sem
);
2676 /* We need to mark inode dirty even if
2677 * new_i_size is less that inode->i_size
2678 * bu greater than i_disksize.(hint delalloc)
2680 ext4_mark_inode_dirty(handle
, inode
);
2683 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
2688 ret2
= ext4_journal_stop(handle
);
2692 return ret
? ret
: copied
;
2695 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
2698 * Drop reserved blocks
2700 BUG_ON(!PageLocked(page
));
2701 if (!page_has_buffers(page
))
2704 ext4_da_page_release_reservation(page
, offset
);
2707 ext4_invalidatepage(page
, offset
);
2714 * bmap() is special. It gets used by applications such as lilo and by
2715 * the swapper to find the on-disk block of a specific piece of data.
2717 * Naturally, this is dangerous if the block concerned is still in the
2718 * journal. If somebody makes a swapfile on an ext4 data-journaling
2719 * filesystem and enables swap, then they may get a nasty shock when the
2720 * data getting swapped to that swapfile suddenly gets overwritten by
2721 * the original zero's written out previously to the journal and
2722 * awaiting writeback in the kernel's buffer cache.
2724 * So, if we see any bmap calls here on a modified, data-journaled file,
2725 * take extra steps to flush any blocks which might be in the cache.
2727 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
2729 struct inode
*inode
= mapping
->host
;
2733 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
2734 test_opt(inode
->i_sb
, DELALLOC
)) {
2736 * With delalloc we want to sync the file
2737 * so that we can make sure we allocate
2740 filemap_write_and_wait(mapping
);
2743 if (EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
2745 * This is a REALLY heavyweight approach, but the use of
2746 * bmap on dirty files is expected to be extremely rare:
2747 * only if we run lilo or swapon on a freshly made file
2748 * do we expect this to happen.
2750 * (bmap requires CAP_SYS_RAWIO so this does not
2751 * represent an unprivileged user DOS attack --- we'd be
2752 * in trouble if mortal users could trigger this path at
2755 * NB. EXT4_STATE_JDATA is not set on files other than
2756 * regular files. If somebody wants to bmap a directory
2757 * or symlink and gets confused because the buffer
2758 * hasn't yet been flushed to disk, they deserve
2759 * everything they get.
2762 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
2763 journal
= EXT4_JOURNAL(inode
);
2764 jbd2_journal_lock_updates(journal
);
2765 err
= jbd2_journal_flush(journal
);
2766 jbd2_journal_unlock_updates(journal
);
2772 return generic_block_bmap(mapping
, block
, ext4_get_block
);
2775 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2781 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2788 * Note that we don't need to start a transaction unless we're journaling data
2789 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2790 * need to file the inode to the transaction's list in ordered mode because if
2791 * we are writing back data added by write(), the inode is already there and if
2792 * we are writing back data modified via mmap(), noone guarantees in which
2793 * transaction the data will hit the disk. In case we are journaling data, we
2794 * cannot start transaction directly because transaction start ranks above page
2795 * lock so we have to do some magic.
2797 * In all journaling modes block_write_full_page() will start the I/O.
2801 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2806 * ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ...
2808 * Same applies to ext4_get_block(). We will deadlock on various things like
2809 * lock_journal and i_data_sem
2811 * Setting PF_MEMALLOC here doesn't work - too many internal memory
2814 * 16May01: If we're reentered then journal_current_handle() will be
2815 * non-zero. We simply *return*.
2817 * 1 July 2001: @@@ FIXME:
2818 * In journalled data mode, a data buffer may be metadata against the
2819 * current transaction. But the same file is part of a shared mapping
2820 * and someone does a writepage() on it.
2822 * We will move the buffer onto the async_data list, but *after* it has
2823 * been dirtied. So there's a small window where we have dirty data on
2826 * Note that this only applies to the last partial page in the file. The
2827 * bit which block_write_full_page() uses prepare/commit for. (That's
2828 * broken code anyway: it's wrong for msync()).
2830 * It's a rare case: affects the final partial page, for journalled data
2831 * where the file is subject to bith write() and writepage() in the same
2832 * transction. To fix it we'll need a custom block_write_full_page().
2833 * We'll probably need that anyway for journalling writepage() output.
2835 * We don't honour synchronous mounts for writepage(). That would be
2836 * disastrous. Any write() or metadata operation will sync the fs for
2840 static int __ext4_normal_writepage(struct page
*page
,
2841 struct writeback_control
*wbc
)
2843 struct inode
*inode
= page
->mapping
->host
;
2845 if (test_opt(inode
->i_sb
, NOBH
))
2846 return nobh_writepage(page
,
2847 ext4_normal_get_block_write
, wbc
);
2849 return block_write_full_page(page
,
2850 ext4_normal_get_block_write
,
2854 static int ext4_normal_writepage(struct page
*page
,
2855 struct writeback_control
*wbc
)
2857 struct inode
*inode
= page
->mapping
->host
;
2858 loff_t size
= i_size_read(inode
);
2861 J_ASSERT(PageLocked(page
));
2862 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2863 len
= size
& ~PAGE_CACHE_MASK
;
2865 len
= PAGE_CACHE_SIZE
;
2867 if (page_has_buffers(page
)) {
2868 /* if page has buffers it should all be mapped
2869 * and allocated. If there are not buffers attached
2870 * to the page we know the page is dirty but it lost
2871 * buffers. That means that at some moment in time
2872 * after write_begin() / write_end() has been called
2873 * all buffers have been clean and thus they must have been
2874 * written at least once. So they are all mapped and we can
2875 * happily proceed with mapping them and writing the page.
2877 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
2878 ext4_bh_unmapped_or_delay
));
2881 if (!ext4_journal_current_handle())
2882 return __ext4_normal_writepage(page
, wbc
);
2884 redirty_page_for_writepage(wbc
, page
);
2889 static int __ext4_journalled_writepage(struct page
*page
,
2890 struct writeback_control
*wbc
)
2892 struct address_space
*mapping
= page
->mapping
;
2893 struct inode
*inode
= mapping
->host
;
2894 struct buffer_head
*page_bufs
;
2895 handle_t
*handle
= NULL
;
2899 ret
= block_prepare_write(page
, 0, PAGE_CACHE_SIZE
,
2900 ext4_normal_get_block_write
);
2904 page_bufs
= page_buffers(page
);
2905 walk_page_buffers(handle
, page_bufs
, 0, PAGE_CACHE_SIZE
, NULL
,
2907 /* As soon as we unlock the page, it can go away, but we have
2908 * references to buffers so we are safe */
2911 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
2912 if (IS_ERR(handle
)) {
2913 ret
= PTR_ERR(handle
);
2917 ret
= walk_page_buffers(handle
, page_bufs
, 0,
2918 PAGE_CACHE_SIZE
, NULL
, do_journal_get_write_access
);
2920 err
= walk_page_buffers(handle
, page_bufs
, 0,
2921 PAGE_CACHE_SIZE
, NULL
, write_end_fn
);
2924 err
= ext4_journal_stop(handle
);
2928 walk_page_buffers(handle
, page_bufs
, 0,
2929 PAGE_CACHE_SIZE
, NULL
, bput_one
);
2930 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
2939 static int ext4_journalled_writepage(struct page
*page
,
2940 struct writeback_control
*wbc
)
2942 struct inode
*inode
= page
->mapping
->host
;
2943 loff_t size
= i_size_read(inode
);
2946 J_ASSERT(PageLocked(page
));
2947 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2948 len
= size
& ~PAGE_CACHE_MASK
;
2950 len
= PAGE_CACHE_SIZE
;
2952 if (page_has_buffers(page
)) {
2953 /* if page has buffers it should all be mapped
2954 * and allocated. If there are not buffers attached
2955 * to the page we know the page is dirty but it lost
2956 * buffers. That means that at some moment in time
2957 * after write_begin() / write_end() has been called
2958 * all buffers have been clean and thus they must have been
2959 * written at least once. So they are all mapped and we can
2960 * happily proceed with mapping them and writing the page.
2962 BUG_ON(walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
2963 ext4_bh_unmapped_or_delay
));
2966 if (ext4_journal_current_handle())
2969 if (PageChecked(page
)) {
2971 * It's mmapped pagecache. Add buffers and journal it. There
2972 * doesn't seem much point in redirtying the page here.
2974 ClearPageChecked(page
);
2975 return __ext4_journalled_writepage(page
, wbc
);
2978 * It may be a page full of checkpoint-mode buffers. We don't
2979 * really know unless we go poke around in the buffer_heads.
2980 * But block_write_full_page will do the right thing.
2982 return block_write_full_page(page
,
2983 ext4_normal_get_block_write
,
2987 redirty_page_for_writepage(wbc
, page
);
2992 static int ext4_readpage(struct file
*file
, struct page
*page
)
2994 return mpage_readpage(page
, ext4_get_block
);
2998 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
2999 struct list_head
*pages
, unsigned nr_pages
)
3001 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3004 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3006 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3009 * If it's a full truncate we just forget about the pending dirtying
3012 ClearPageChecked(page
);
3014 jbd2_journal_invalidatepage(journal
, page
, offset
);
3017 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3019 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3021 WARN_ON(PageChecked(page
));
3022 if (!page_has_buffers(page
))
3024 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3028 * If the O_DIRECT write will extend the file then add this inode to the
3029 * orphan list. So recovery will truncate it back to the original size
3030 * if the machine crashes during the write.
3032 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3033 * crashes then stale disk data _may_ be exposed inside the file. But current
3034 * VFS code falls back into buffered path in that case so we are safe.
3036 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3037 const struct iovec
*iov
, loff_t offset
,
3038 unsigned long nr_segs
)
3040 struct file
*file
= iocb
->ki_filp
;
3041 struct inode
*inode
= file
->f_mapping
->host
;
3042 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3046 size_t count
= iov_length(iov
, nr_segs
);
3049 loff_t final_size
= offset
+ count
;
3051 if (final_size
> inode
->i_size
) {
3052 /* Credits for sb + inode write */
3053 handle
= ext4_journal_start(inode
, 2);
3054 if (IS_ERR(handle
)) {
3055 ret
= PTR_ERR(handle
);
3058 ret
= ext4_orphan_add(handle
, inode
);
3060 ext4_journal_stop(handle
);
3064 ei
->i_disksize
= inode
->i_size
;
3065 ext4_journal_stop(handle
);
3069 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3071 ext4_get_block
, NULL
);
3076 /* Credits for sb + inode write */
3077 handle
= ext4_journal_start(inode
, 2);
3078 if (IS_ERR(handle
)) {
3079 /* This is really bad luck. We've written the data
3080 * but cannot extend i_size. Bail out and pretend
3081 * the write failed... */
3082 ret
= PTR_ERR(handle
);
3086 ext4_orphan_del(handle
, inode
);
3088 loff_t end
= offset
+ ret
;
3089 if (end
> inode
->i_size
) {
3090 ei
->i_disksize
= end
;
3091 i_size_write(inode
, end
);
3093 * We're going to return a positive `ret'
3094 * here due to non-zero-length I/O, so there's
3095 * no way of reporting error returns from
3096 * ext4_mark_inode_dirty() to userspace. So
3099 ext4_mark_inode_dirty(handle
, inode
);
3102 err
= ext4_journal_stop(handle
);
3111 * Pages can be marked dirty completely asynchronously from ext4's journalling
3112 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3113 * much here because ->set_page_dirty is called under VFS locks. The page is
3114 * not necessarily locked.
3116 * We cannot just dirty the page and leave attached buffers clean, because the
3117 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3118 * or jbddirty because all the journalling code will explode.
3120 * So what we do is to mark the page "pending dirty" and next time writepage
3121 * is called, propagate that into the buffers appropriately.
3123 static int ext4_journalled_set_page_dirty(struct page
*page
)
3125 SetPageChecked(page
);
3126 return __set_page_dirty_nobuffers(page
);
3129 static const struct address_space_operations ext4_ordered_aops
= {
3130 .readpage
= ext4_readpage
,
3131 .readpages
= ext4_readpages
,
3132 .writepage
= ext4_normal_writepage
,
3133 .sync_page
= block_sync_page
,
3134 .write_begin
= ext4_write_begin
,
3135 .write_end
= ext4_ordered_write_end
,
3137 .invalidatepage
= ext4_invalidatepage
,
3138 .releasepage
= ext4_releasepage
,
3139 .direct_IO
= ext4_direct_IO
,
3140 .migratepage
= buffer_migrate_page
,
3141 .is_partially_uptodate
= block_is_partially_uptodate
,
3144 static const struct address_space_operations ext4_writeback_aops
= {
3145 .readpage
= ext4_readpage
,
3146 .readpages
= ext4_readpages
,
3147 .writepage
= ext4_normal_writepage
,
3148 .sync_page
= block_sync_page
,
3149 .write_begin
= ext4_write_begin
,
3150 .write_end
= ext4_writeback_write_end
,
3152 .invalidatepage
= ext4_invalidatepage
,
3153 .releasepage
= ext4_releasepage
,
3154 .direct_IO
= ext4_direct_IO
,
3155 .migratepage
= buffer_migrate_page
,
3156 .is_partially_uptodate
= block_is_partially_uptodate
,
3159 static const struct address_space_operations ext4_journalled_aops
= {
3160 .readpage
= ext4_readpage
,
3161 .readpages
= ext4_readpages
,
3162 .writepage
= ext4_journalled_writepage
,
3163 .sync_page
= block_sync_page
,
3164 .write_begin
= ext4_write_begin
,
3165 .write_end
= ext4_journalled_write_end
,
3166 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3168 .invalidatepage
= ext4_invalidatepage
,
3169 .releasepage
= ext4_releasepage
,
3170 .is_partially_uptodate
= block_is_partially_uptodate
,
3173 static const struct address_space_operations ext4_da_aops
= {
3174 .readpage
= ext4_readpage
,
3175 .readpages
= ext4_readpages
,
3176 .writepage
= ext4_da_writepage
,
3177 .writepages
= ext4_da_writepages
,
3178 .sync_page
= block_sync_page
,
3179 .write_begin
= ext4_da_write_begin
,
3180 .write_end
= ext4_da_write_end
,
3182 .invalidatepage
= ext4_da_invalidatepage
,
3183 .releasepage
= ext4_releasepage
,
3184 .direct_IO
= ext4_direct_IO
,
3185 .migratepage
= buffer_migrate_page
,
3186 .is_partially_uptodate
= block_is_partially_uptodate
,
3189 void ext4_set_aops(struct inode
*inode
)
3191 if (ext4_should_order_data(inode
) &&
3192 test_opt(inode
->i_sb
, DELALLOC
))
3193 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3194 else if (ext4_should_order_data(inode
))
3195 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3196 else if (ext4_should_writeback_data(inode
) &&
3197 test_opt(inode
->i_sb
, DELALLOC
))
3198 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3199 else if (ext4_should_writeback_data(inode
))
3200 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3202 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3206 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3207 * up to the end of the block which corresponds to `from'.
3208 * This required during truncate. We need to physically zero the tail end
3209 * of that block so it doesn't yield old data if the file is later grown.
3211 int ext4_block_truncate_page(handle_t
*handle
,
3212 struct address_space
*mapping
, loff_t from
)
3214 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3215 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3216 unsigned blocksize
, length
, pos
;
3218 struct inode
*inode
= mapping
->host
;
3219 struct buffer_head
*bh
;
3223 page
= grab_cache_page(mapping
, from
>> PAGE_CACHE_SHIFT
);
3227 blocksize
= inode
->i_sb
->s_blocksize
;
3228 length
= blocksize
- (offset
& (blocksize
- 1));
3229 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3232 * For "nobh" option, we can only work if we don't need to
3233 * read-in the page - otherwise we create buffers to do the IO.
3235 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3236 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3237 zero_user(page
, offset
, length
);
3238 set_page_dirty(page
);
3242 if (!page_has_buffers(page
))
3243 create_empty_buffers(page
, blocksize
, 0);
3245 /* Find the buffer that contains "offset" */
3246 bh
= page_buffers(page
);
3248 while (offset
>= pos
) {
3249 bh
= bh
->b_this_page
;
3255 if (buffer_freed(bh
)) {
3256 BUFFER_TRACE(bh
, "freed: skip");
3260 if (!buffer_mapped(bh
)) {
3261 BUFFER_TRACE(bh
, "unmapped");
3262 ext4_get_block(inode
, iblock
, bh
, 0);
3263 /* unmapped? It's a hole - nothing to do */
3264 if (!buffer_mapped(bh
)) {
3265 BUFFER_TRACE(bh
, "still unmapped");
3270 /* Ok, it's mapped. Make sure it's up-to-date */
3271 if (PageUptodate(page
))
3272 set_buffer_uptodate(bh
);
3274 if (!buffer_uptodate(bh
)) {
3276 ll_rw_block(READ
, 1, &bh
);
3278 /* Uhhuh. Read error. Complain and punt. */
3279 if (!buffer_uptodate(bh
))
3283 if (ext4_should_journal_data(inode
)) {
3284 BUFFER_TRACE(bh
, "get write access");
3285 err
= ext4_journal_get_write_access(handle
, bh
);
3290 zero_user(page
, offset
, length
);
3292 BUFFER_TRACE(bh
, "zeroed end of block");
3295 if (ext4_should_journal_data(inode
)) {
3296 err
= ext4_journal_dirty_metadata(handle
, bh
);
3298 if (ext4_should_order_data(inode
))
3299 err
= ext4_jbd2_file_inode(handle
, inode
);
3300 mark_buffer_dirty(bh
);
3305 page_cache_release(page
);
3310 * Probably it should be a library function... search for first non-zero word
3311 * or memcmp with zero_page, whatever is better for particular architecture.
3314 static inline int all_zeroes(__le32
*p
, __le32
*q
)
3323 * ext4_find_shared - find the indirect blocks for partial truncation.
3324 * @inode: inode in question
3325 * @depth: depth of the affected branch
3326 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
3327 * @chain: place to store the pointers to partial indirect blocks
3328 * @top: place to the (detached) top of branch
3330 * This is a helper function used by ext4_truncate().
3332 * When we do truncate() we may have to clean the ends of several
3333 * indirect blocks but leave the blocks themselves alive. Block is
3334 * partially truncated if some data below the new i_size is refered
3335 * from it (and it is on the path to the first completely truncated
3336 * data block, indeed). We have to free the top of that path along
3337 * with everything to the right of the path. Since no allocation
3338 * past the truncation point is possible until ext4_truncate()
3339 * finishes, we may safely do the latter, but top of branch may
3340 * require special attention - pageout below the truncation point
3341 * might try to populate it.
3343 * We atomically detach the top of branch from the tree, store the
3344 * block number of its root in *@top, pointers to buffer_heads of
3345 * partially truncated blocks - in @chain[].bh and pointers to
3346 * their last elements that should not be removed - in
3347 * @chain[].p. Return value is the pointer to last filled element
3350 * The work left to caller to do the actual freeing of subtrees:
3351 * a) free the subtree starting from *@top
3352 * b) free the subtrees whose roots are stored in
3353 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
3354 * c) free the subtrees growing from the inode past the @chain[0].
3355 * (no partially truncated stuff there). */
3357 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
3358 ext4_lblk_t offsets
[4], Indirect chain
[4], __le32
*top
)
3360 Indirect
*partial
, *p
;
3364 /* Make k index the deepest non-null offest + 1 */
3365 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
3367 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
3368 /* Writer: pointers */
3370 partial
= chain
+ k
-1;
3372 * If the branch acquired continuation since we've looked at it -
3373 * fine, it should all survive and (new) top doesn't belong to us.
3375 if (!partial
->key
&& *partial
->p
)
3378 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
3381 * OK, we've found the last block that must survive. The rest of our
3382 * branch should be detached before unlocking. However, if that rest
3383 * of branch is all ours and does not grow immediately from the inode
3384 * it's easier to cheat and just decrement partial->p.
3386 if (p
== chain
+ k
- 1 && p
> chain
) {
3390 /* Nope, don't do this in ext4. Must leave the tree intact */
3397 while (partial
> p
) {
3398 brelse(partial
->bh
);
3406 * Zero a number of block pointers in either an inode or an indirect block.
3407 * If we restart the transaction we must again get write access to the
3408 * indirect block for further modification.
3410 * We release `count' blocks on disk, but (last - first) may be greater
3411 * than `count' because there can be holes in there.
3413 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
3414 struct buffer_head
*bh
, ext4_fsblk_t block_to_free
,
3415 unsigned long count
, __le32
*first
, __le32
*last
)
3418 if (try_to_extend_transaction(handle
, inode
)) {
3420 BUFFER_TRACE(bh
, "call ext4_journal_dirty_metadata");
3421 ext4_journal_dirty_metadata(handle
, bh
);
3423 ext4_mark_inode_dirty(handle
, inode
);
3424 ext4_journal_test_restart(handle
, inode
);
3426 BUFFER_TRACE(bh
, "retaking write access");
3427 ext4_journal_get_write_access(handle
, bh
);
3432 * Any buffers which are on the journal will be in memory. We find
3433 * them on the hash table so jbd2_journal_revoke() will run jbd2_journal_forget()
3434 * on them. We've already detached each block from the file, so
3435 * bforget() in jbd2_journal_forget() should be safe.
3437 * AKPM: turn on bforget in jbd2_journal_forget()!!!
3439 for (p
= first
; p
< last
; p
++) {
3440 u32 nr
= le32_to_cpu(*p
);
3442 struct buffer_head
*tbh
;
3445 tbh
= sb_find_get_block(inode
->i_sb
, nr
);
3446 ext4_forget(handle
, 0, inode
, tbh
, nr
);
3450 ext4_free_blocks(handle
, inode
, block_to_free
, count
, 0);
3454 * ext4_free_data - free a list of data blocks
3455 * @handle: handle for this transaction
3456 * @inode: inode we are dealing with
3457 * @this_bh: indirect buffer_head which contains *@first and *@last
3458 * @first: array of block numbers
3459 * @last: points immediately past the end of array
3461 * We are freeing all blocks refered from that array (numbers are stored as
3462 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
3464 * We accumulate contiguous runs of blocks to free. Conveniently, if these
3465 * blocks are contiguous then releasing them at one time will only affect one
3466 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
3467 * actually use a lot of journal space.
3469 * @this_bh will be %NULL if @first and @last point into the inode's direct
3472 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
3473 struct buffer_head
*this_bh
,
3474 __le32
*first
, __le32
*last
)
3476 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
3477 unsigned long count
= 0; /* Number of blocks in the run */
3478 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
3481 ext4_fsblk_t nr
; /* Current block # */
3482 __le32
*p
; /* Pointer into inode/ind
3483 for current block */
3486 if (this_bh
) { /* For indirect block */
3487 BUFFER_TRACE(this_bh
, "get_write_access");
3488 err
= ext4_journal_get_write_access(handle
, this_bh
);
3489 /* Important: if we can't update the indirect pointers
3490 * to the blocks, we can't free them. */
3495 for (p
= first
; p
< last
; p
++) {
3496 nr
= le32_to_cpu(*p
);
3498 /* accumulate blocks to free if they're contiguous */
3501 block_to_free_p
= p
;
3503 } else if (nr
== block_to_free
+ count
) {
3506 ext4_clear_blocks(handle
, inode
, this_bh
,
3508 count
, block_to_free_p
, p
);
3510 block_to_free_p
= p
;
3517 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
3518 count
, block_to_free_p
, p
);
3521 BUFFER_TRACE(this_bh
, "call ext4_journal_dirty_metadata");
3524 * The buffer head should have an attached journal head at this
3525 * point. However, if the data is corrupted and an indirect
3526 * block pointed to itself, it would have been detached when
3527 * the block was cleared. Check for this instead of OOPSing.
3530 ext4_journal_dirty_metadata(handle
, this_bh
);
3532 ext4_error(inode
->i_sb
, __func__
,
3533 "circular indirect block detected, "
3534 "inode=%lu, block=%llu",
3536 (unsigned long long) this_bh
->b_blocknr
);
3541 * ext4_free_branches - free an array of branches
3542 * @handle: JBD handle for this transaction
3543 * @inode: inode we are dealing with
3544 * @parent_bh: the buffer_head which contains *@first and *@last
3545 * @first: array of block numbers
3546 * @last: pointer immediately past the end of array
3547 * @depth: depth of the branches to free
3549 * We are freeing all blocks refered from these branches (numbers are
3550 * stored as little-endian 32-bit) and updating @inode->i_blocks
3553 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
3554 struct buffer_head
*parent_bh
,
3555 __le32
*first
, __le32
*last
, int depth
)
3560 if (is_handle_aborted(handle
))
3564 struct buffer_head
*bh
;
3565 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
3567 while (--p
>= first
) {
3568 nr
= le32_to_cpu(*p
);
3570 continue; /* A hole */
3572 /* Go read the buffer for the next level down */
3573 bh
= sb_bread(inode
->i_sb
, nr
);
3576 * A read failure? Report error and clear slot
3580 ext4_error(inode
->i_sb
, "ext4_free_branches",
3581 "Read failure, inode=%lu, block=%llu",
3586 /* This zaps the entire block. Bottom up. */
3587 BUFFER_TRACE(bh
, "free child branches");
3588 ext4_free_branches(handle
, inode
, bh
,
3589 (__le32
*) bh
->b_data
,
3590 (__le32
*) bh
->b_data
+ addr_per_block
,
3594 * We've probably journalled the indirect block several
3595 * times during the truncate. But it's no longer
3596 * needed and we now drop it from the transaction via
3597 * jbd2_journal_revoke().
3599 * That's easy if it's exclusively part of this
3600 * transaction. But if it's part of the committing
3601 * transaction then jbd2_journal_forget() will simply
3602 * brelse() it. That means that if the underlying
3603 * block is reallocated in ext4_get_block(),
3604 * unmap_underlying_metadata() will find this block
3605 * and will try to get rid of it. damn, damn.
3607 * If this block has already been committed to the
3608 * journal, a revoke record will be written. And
3609 * revoke records must be emitted *before* clearing
3610 * this block's bit in the bitmaps.
3612 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
3615 * Everything below this this pointer has been
3616 * released. Now let this top-of-subtree go.
3618 * We want the freeing of this indirect block to be
3619 * atomic in the journal with the updating of the
3620 * bitmap block which owns it. So make some room in
3623 * We zero the parent pointer *after* freeing its
3624 * pointee in the bitmaps, so if extend_transaction()
3625 * for some reason fails to put the bitmap changes and
3626 * the release into the same transaction, recovery
3627 * will merely complain about releasing a free block,
3628 * rather than leaking blocks.
3630 if (is_handle_aborted(handle
))
3632 if (try_to_extend_transaction(handle
, inode
)) {
3633 ext4_mark_inode_dirty(handle
, inode
);
3634 ext4_journal_test_restart(handle
, inode
);
3637 ext4_free_blocks(handle
, inode
, nr
, 1, 1);
3641 * The block which we have just freed is
3642 * pointed to by an indirect block: journal it
3644 BUFFER_TRACE(parent_bh
, "get_write_access");
3645 if (!ext4_journal_get_write_access(handle
,
3648 BUFFER_TRACE(parent_bh
,
3649 "call ext4_journal_dirty_metadata");
3650 ext4_journal_dirty_metadata(handle
,
3656 /* We have reached the bottom of the tree. */
3657 BUFFER_TRACE(parent_bh
, "free data blocks");
3658 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
3662 int ext4_can_truncate(struct inode
*inode
)
3664 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
3666 if (S_ISREG(inode
->i_mode
))
3668 if (S_ISDIR(inode
->i_mode
))
3670 if (S_ISLNK(inode
->i_mode
))
3671 return !ext4_inode_is_fast_symlink(inode
);
3678 * We block out ext4_get_block() block instantiations across the entire
3679 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3680 * simultaneously on behalf of the same inode.
3682 * As we work through the truncate and commmit bits of it to the journal there
3683 * is one core, guiding principle: the file's tree must always be consistent on
3684 * disk. We must be able to restart the truncate after a crash.
3686 * The file's tree may be transiently inconsistent in memory (although it
3687 * probably isn't), but whenever we close off and commit a journal transaction,
3688 * the contents of (the filesystem + the journal) must be consistent and
3689 * restartable. It's pretty simple, really: bottom up, right to left (although
3690 * left-to-right works OK too).
3692 * Note that at recovery time, journal replay occurs *before* the restart of
3693 * truncate against the orphan inode list.
3695 * The committed inode has the new, desired i_size (which is the same as
3696 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3697 * that this inode's truncate did not complete and it will again call
3698 * ext4_truncate() to have another go. So there will be instantiated blocks
3699 * to the right of the truncation point in a crashed ext4 filesystem. But
3700 * that's fine - as long as they are linked from the inode, the post-crash
3701 * ext4_truncate() run will find them and release them.
3703 void ext4_truncate(struct inode
*inode
)
3706 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3707 __le32
*i_data
= ei
->i_data
;
3708 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
3709 struct address_space
*mapping
= inode
->i_mapping
;
3710 ext4_lblk_t offsets
[4];
3715 ext4_lblk_t last_block
;
3716 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
3718 if (!ext4_can_truncate(inode
))
3721 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
3722 ext4_ext_truncate(inode
);
3726 handle
= start_transaction(inode
);
3728 return; /* AKPM: return what? */
3730 last_block
= (inode
->i_size
+ blocksize
-1)
3731 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
3733 if (inode
->i_size
& (blocksize
- 1))
3734 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
3737 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
3739 goto out_stop
; /* error */
3742 * OK. This truncate is going to happen. We add the inode to the
3743 * orphan list, so that if this truncate spans multiple transactions,
3744 * and we crash, we will resume the truncate when the filesystem
3745 * recovers. It also marks the inode dirty, to catch the new size.
3747 * Implication: the file must always be in a sane, consistent
3748 * truncatable state while each transaction commits.
3750 if (ext4_orphan_add(handle
, inode
))
3754 * From here we block out all ext4_get_block() callers who want to
3755 * modify the block allocation tree.
3757 down_write(&ei
->i_data_sem
);
3759 ext4_discard_preallocations(inode
);
3762 * The orphan list entry will now protect us from any crash which
3763 * occurs before the truncate completes, so it is now safe to propagate
3764 * the new, shorter inode size (held for now in i_size) into the
3765 * on-disk inode. We do this via i_disksize, which is the value which
3766 * ext4 *really* writes onto the disk inode.
3768 ei
->i_disksize
= inode
->i_size
;
3770 if (n
== 1) { /* direct blocks */
3771 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
3772 i_data
+ EXT4_NDIR_BLOCKS
);
3776 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
3777 /* Kill the top of shared branch (not detached) */
3779 if (partial
== chain
) {
3780 /* Shared branch grows from the inode */
3781 ext4_free_branches(handle
, inode
, NULL
,
3782 &nr
, &nr
+1, (chain
+n
-1) - partial
);
3785 * We mark the inode dirty prior to restart,
3786 * and prior to stop. No need for it here.
3789 /* Shared branch grows from an indirect block */
3790 BUFFER_TRACE(partial
->bh
, "get_write_access");
3791 ext4_free_branches(handle
, inode
, partial
->bh
,
3793 partial
->p
+1, (chain
+n
-1) - partial
);
3796 /* Clear the ends of indirect blocks on the shared branch */
3797 while (partial
> chain
) {
3798 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
3799 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
3800 (chain
+n
-1) - partial
);
3801 BUFFER_TRACE(partial
->bh
, "call brelse");
3802 brelse (partial
->bh
);
3806 /* Kill the remaining (whole) subtrees */
3807 switch (offsets
[0]) {
3809 nr
= i_data
[EXT4_IND_BLOCK
];
3811 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
3812 i_data
[EXT4_IND_BLOCK
] = 0;
3814 case EXT4_IND_BLOCK
:
3815 nr
= i_data
[EXT4_DIND_BLOCK
];
3817 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
3818 i_data
[EXT4_DIND_BLOCK
] = 0;
3820 case EXT4_DIND_BLOCK
:
3821 nr
= i_data
[EXT4_TIND_BLOCK
];
3823 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
3824 i_data
[EXT4_TIND_BLOCK
] = 0;
3826 case EXT4_TIND_BLOCK
:
3830 up_write(&ei
->i_data_sem
);
3831 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
3832 ext4_mark_inode_dirty(handle
, inode
);
3835 * In a multi-transaction truncate, we only make the final transaction
3842 * If this was a simple ftruncate(), and the file will remain alive
3843 * then we need to clear up the orphan record which we created above.
3844 * However, if this was a real unlink then we were called by
3845 * ext4_delete_inode(), and we allow that function to clean up the
3846 * orphan info for us.
3849 ext4_orphan_del(handle
, inode
);
3851 ext4_journal_stop(handle
);
3855 * ext4_get_inode_loc returns with an extra refcount against the inode's
3856 * underlying buffer_head on success. If 'in_mem' is true, we have all
3857 * data in memory that is needed to recreate the on-disk version of this
3860 static int __ext4_get_inode_loc(struct inode
*inode
,
3861 struct ext4_iloc
*iloc
, int in_mem
)
3863 struct ext4_group_desc
*gdp
;
3864 struct buffer_head
*bh
;
3865 struct super_block
*sb
= inode
->i_sb
;
3867 int inodes_per_block
, inode_offset
;
3870 if (!ext4_valid_inum(sb
, inode
->i_ino
))
3873 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
3874 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
3879 * Figure out the offset within the block group inode table
3881 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
3882 inode_offset
= ((inode
->i_ino
- 1) %
3883 EXT4_INODES_PER_GROUP(sb
));
3884 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
3885 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
3887 bh
= sb_getblk(sb
, block
);
3889 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
3890 "inode block - inode=%lu, block=%llu",
3891 inode
->i_ino
, block
);
3894 if (!buffer_uptodate(bh
)) {
3898 * If the buffer has the write error flag, we have failed
3899 * to write out another inode in the same block. In this
3900 * case, we don't have to read the block because we may
3901 * read the old inode data successfully.
3903 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
3904 set_buffer_uptodate(bh
);
3906 if (buffer_uptodate(bh
)) {
3907 /* someone brought it uptodate while we waited */
3913 * If we have all information of the inode in memory and this
3914 * is the only valid inode in the block, we need not read the
3918 struct buffer_head
*bitmap_bh
;
3921 start
= inode_offset
& ~(inodes_per_block
- 1);
3923 /* Is the inode bitmap in cache? */
3924 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
3929 * If the inode bitmap isn't in cache then the
3930 * optimisation may end up performing two reads instead
3931 * of one, so skip it.
3933 if (!buffer_uptodate(bitmap_bh
)) {
3937 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
3938 if (i
== inode_offset
)
3940 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
3944 if (i
== start
+ inodes_per_block
) {
3945 /* all other inodes are free, so skip I/O */
3946 memset(bh
->b_data
, 0, bh
->b_size
);
3947 set_buffer_uptodate(bh
);
3955 * If we need to do any I/O, try to pre-readahead extra
3956 * blocks from the inode table.
3958 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
3959 ext4_fsblk_t b
, end
, table
;
3962 table
= ext4_inode_table(sb
, gdp
);
3963 /* Make sure s_inode_readahead_blks is a power of 2 */
3964 while (EXT4_SB(sb
)->s_inode_readahead_blks
&
3965 (EXT4_SB(sb
)->s_inode_readahead_blks
-1))
3966 EXT4_SB(sb
)->s_inode_readahead_blks
=
3967 (EXT4_SB(sb
)->s_inode_readahead_blks
&
3968 (EXT4_SB(sb
)->s_inode_readahead_blks
-1));
3969 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
3972 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
3973 num
= EXT4_INODES_PER_GROUP(sb
);
3974 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
3975 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
3976 num
-= le16_to_cpu(gdp
->bg_itable_unused
);
3977 table
+= num
/ inodes_per_block
;
3981 sb_breadahead(sb
, b
++);
3985 * There are other valid inodes in the buffer, this inode
3986 * has in-inode xattrs, or we don't have this inode in memory.
3987 * Read the block from disk.
3990 bh
->b_end_io
= end_buffer_read_sync
;
3991 submit_bh(READ_META
, bh
);
3993 if (!buffer_uptodate(bh
)) {
3994 ext4_error(sb
, __func__
,
3995 "unable to read inode block - inode=%lu, "
3996 "block=%llu", inode
->i_ino
, block
);
4006 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4008 /* We have all inode data except xattrs in memory here. */
4009 return __ext4_get_inode_loc(inode
, iloc
,
4010 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4013 void ext4_set_inode_flags(struct inode
*inode
)
4015 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4017 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4018 if (flags
& EXT4_SYNC_FL
)
4019 inode
->i_flags
|= S_SYNC
;
4020 if (flags
& EXT4_APPEND_FL
)
4021 inode
->i_flags
|= S_APPEND
;
4022 if (flags
& EXT4_IMMUTABLE_FL
)
4023 inode
->i_flags
|= S_IMMUTABLE
;
4024 if (flags
& EXT4_NOATIME_FL
)
4025 inode
->i_flags
|= S_NOATIME
;
4026 if (flags
& EXT4_DIRSYNC_FL
)
4027 inode
->i_flags
|= S_DIRSYNC
;
4030 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4031 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4033 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4035 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4036 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4038 ei
->i_flags
|= EXT4_SYNC_FL
;
4039 if (flags
& S_APPEND
)
4040 ei
->i_flags
|= EXT4_APPEND_FL
;
4041 if (flags
& S_IMMUTABLE
)
4042 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4043 if (flags
& S_NOATIME
)
4044 ei
->i_flags
|= EXT4_NOATIME_FL
;
4045 if (flags
& S_DIRSYNC
)
4046 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4048 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4049 struct ext4_inode_info
*ei
)
4052 struct inode
*inode
= &(ei
->vfs_inode
);
4053 struct super_block
*sb
= inode
->i_sb
;
4055 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4056 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4057 /* we are using combined 48 bit field */
4058 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4059 le32_to_cpu(raw_inode
->i_blocks_lo
);
4060 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4061 /* i_blocks represent file system block size */
4062 return i_blocks
<< (inode
->i_blkbits
- 9);
4067 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4071 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4073 struct ext4_iloc iloc
;
4074 struct ext4_inode
*raw_inode
;
4075 struct ext4_inode_info
*ei
;
4076 struct buffer_head
*bh
;
4077 struct inode
*inode
;
4081 inode
= iget_locked(sb
, ino
);
4083 return ERR_PTR(-ENOMEM
);
4084 if (!(inode
->i_state
& I_NEW
))
4088 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4089 ei
->i_acl
= EXT4_ACL_NOT_CACHED
;
4090 ei
->i_default_acl
= EXT4_ACL_NOT_CACHED
;
4093 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4097 raw_inode
= ext4_raw_inode(&iloc
);
4098 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4099 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4100 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4101 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4102 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4103 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4105 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4108 ei
->i_dir_start_lookup
= 0;
4109 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4110 /* We now have enough fields to check if the inode was active or not.
4111 * This is needed because nfsd might try to access dead inodes
4112 * the test is that same one that e2fsck uses
4113 * NeilBrown 1999oct15
4115 if (inode
->i_nlink
== 0) {
4116 if (inode
->i_mode
== 0 ||
4117 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4118 /* this inode is deleted */
4123 /* The only unlinked inodes we let through here have
4124 * valid i_mode and are being read by the orphan
4125 * recovery code: that's fine, we're about to complete
4126 * the process of deleting those. */
4128 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4129 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4130 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4131 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
4132 cpu_to_le32(EXT4_OS_HURD
)) {
4134 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4136 inode
->i_size
= ext4_isize(raw_inode
);
4137 ei
->i_disksize
= inode
->i_size
;
4138 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4139 ei
->i_block_group
= iloc
.block_group
;
4141 * NOTE! The in-memory inode i_data array is in little-endian order
4142 * even on big-endian machines: we do NOT byteswap the block numbers!
4144 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4145 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4146 INIT_LIST_HEAD(&ei
->i_orphan
);
4148 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4149 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4150 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4151 EXT4_INODE_SIZE(inode
->i_sb
)) {
4156 if (ei
->i_extra_isize
== 0) {
4157 /* The extra space is currently unused. Use it. */
4158 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4159 EXT4_GOOD_OLD_INODE_SIZE
;
4161 __le32
*magic
= (void *)raw_inode
+
4162 EXT4_GOOD_OLD_INODE_SIZE
+
4164 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4165 ei
->i_state
|= EXT4_STATE_XATTR
;
4168 ei
->i_extra_isize
= 0;
4170 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4171 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4172 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4173 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4175 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4176 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4177 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4179 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4182 if (S_ISREG(inode
->i_mode
)) {
4183 inode
->i_op
= &ext4_file_inode_operations
;
4184 inode
->i_fop
= &ext4_file_operations
;
4185 ext4_set_aops(inode
);
4186 } else if (S_ISDIR(inode
->i_mode
)) {
4187 inode
->i_op
= &ext4_dir_inode_operations
;
4188 inode
->i_fop
= &ext4_dir_operations
;
4189 } else if (S_ISLNK(inode
->i_mode
)) {
4190 if (ext4_inode_is_fast_symlink(inode
)) {
4191 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4192 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4193 sizeof(ei
->i_data
) - 1);
4195 inode
->i_op
= &ext4_symlink_inode_operations
;
4196 ext4_set_aops(inode
);
4199 inode
->i_op
= &ext4_special_inode_operations
;
4200 if (raw_inode
->i_block
[0])
4201 init_special_inode(inode
, inode
->i_mode
,
4202 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4204 init_special_inode(inode
, inode
->i_mode
,
4205 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4208 ext4_set_inode_flags(inode
);
4209 unlock_new_inode(inode
);
4214 return ERR_PTR(ret
);
4217 static int ext4_inode_blocks_set(handle_t
*handle
,
4218 struct ext4_inode
*raw_inode
,
4219 struct ext4_inode_info
*ei
)
4221 struct inode
*inode
= &(ei
->vfs_inode
);
4222 u64 i_blocks
= inode
->i_blocks
;
4223 struct super_block
*sb
= inode
->i_sb
;
4225 if (i_blocks
<= ~0U) {
4227 * i_blocks can be represnted in a 32 bit variable
4228 * as multiple of 512 bytes
4230 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4231 raw_inode
->i_blocks_high
= 0;
4232 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4235 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
4238 if (i_blocks
<= 0xffffffffffffULL
) {
4240 * i_blocks can be represented in a 48 bit variable
4241 * as multiple of 512 bytes
4243 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4244 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4245 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4247 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
4248 /* i_block is stored in file system block size */
4249 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
4250 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4251 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4257 * Post the struct inode info into an on-disk inode location in the
4258 * buffer-cache. This gobbles the caller's reference to the
4259 * buffer_head in the inode location struct.
4261 * The caller must have write access to iloc->bh.
4263 static int ext4_do_update_inode(handle_t
*handle
,
4264 struct inode
*inode
,
4265 struct ext4_iloc
*iloc
)
4267 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
4268 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4269 struct buffer_head
*bh
= iloc
->bh
;
4270 int err
= 0, rc
, block
;
4272 /* For fields not not tracking in the in-memory inode,
4273 * initialise them to zero for new inodes. */
4274 if (ei
->i_state
& EXT4_STATE_NEW
)
4275 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
4277 ext4_get_inode_flags(ei
);
4278 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
4279 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4280 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
4281 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
4283 * Fix up interoperability with old kernels. Otherwise, old inodes get
4284 * re-used with the upper 16 bits of the uid/gid intact
4287 raw_inode
->i_uid_high
=
4288 cpu_to_le16(high_16_bits(inode
->i_uid
));
4289 raw_inode
->i_gid_high
=
4290 cpu_to_le16(high_16_bits(inode
->i_gid
));
4292 raw_inode
->i_uid_high
= 0;
4293 raw_inode
->i_gid_high
= 0;
4296 raw_inode
->i_uid_low
=
4297 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
4298 raw_inode
->i_gid_low
=
4299 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
4300 raw_inode
->i_uid_high
= 0;
4301 raw_inode
->i_gid_high
= 0;
4303 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
4305 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
4306 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
4307 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
4308 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
4310 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
4312 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
4313 /* clear the migrate flag in the raw_inode */
4314 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
& ~EXT4_EXT_MIGRATE
);
4315 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
4316 cpu_to_le32(EXT4_OS_HURD
))
4317 raw_inode
->i_file_acl_high
=
4318 cpu_to_le16(ei
->i_file_acl
>> 32);
4319 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
4320 ext4_isize_set(raw_inode
, ei
->i_disksize
);
4321 if (ei
->i_disksize
> 0x7fffffffULL
) {
4322 struct super_block
*sb
= inode
->i_sb
;
4323 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4324 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
4325 EXT4_SB(sb
)->s_es
->s_rev_level
==
4326 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
4327 /* If this is the first large file
4328 * created, add a flag to the superblock.
4330 err
= ext4_journal_get_write_access(handle
,
4331 EXT4_SB(sb
)->s_sbh
);
4334 ext4_update_dynamic_rev(sb
);
4335 EXT4_SET_RO_COMPAT_FEATURE(sb
,
4336 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
4339 err
= ext4_journal_dirty_metadata(handle
,
4340 EXT4_SB(sb
)->s_sbh
);
4343 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
4344 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
4345 if (old_valid_dev(inode
->i_rdev
)) {
4346 raw_inode
->i_block
[0] =
4347 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
4348 raw_inode
->i_block
[1] = 0;
4350 raw_inode
->i_block
[0] = 0;
4351 raw_inode
->i_block
[1] =
4352 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
4353 raw_inode
->i_block
[2] = 0;
4355 } else for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4356 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
4358 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
4359 if (ei
->i_extra_isize
) {
4360 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4361 raw_inode
->i_version_hi
=
4362 cpu_to_le32(inode
->i_version
>> 32);
4363 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
4367 BUFFER_TRACE(bh
, "call ext4_journal_dirty_metadata");
4368 rc
= ext4_journal_dirty_metadata(handle
, bh
);
4371 ei
->i_state
&= ~EXT4_STATE_NEW
;
4375 ext4_std_error(inode
->i_sb
, err
);
4380 * ext4_write_inode()
4382 * We are called from a few places:
4384 * - Within generic_file_write() for O_SYNC files.
4385 * Here, there will be no transaction running. We wait for any running
4386 * trasnaction to commit.
4388 * - Within sys_sync(), kupdate and such.
4389 * We wait on commit, if tol to.
4391 * - Within prune_icache() (PF_MEMALLOC == true)
4392 * Here we simply return. We can't afford to block kswapd on the
4395 * In all cases it is actually safe for us to return without doing anything,
4396 * because the inode has been copied into a raw inode buffer in
4397 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
4400 * Note that we are absolutely dependent upon all inode dirtiers doing the
4401 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4402 * which we are interested.
4404 * It would be a bug for them to not do this. The code:
4406 * mark_inode_dirty(inode)
4408 * inode->i_size = expr;
4410 * is in error because a kswapd-driven write_inode() could occur while
4411 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4412 * will no longer be on the superblock's dirty inode list.
4414 int ext4_write_inode(struct inode
*inode
, int wait
)
4416 if (current
->flags
& PF_MEMALLOC
)
4419 if (ext4_journal_current_handle()) {
4420 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4428 return ext4_force_commit(inode
->i_sb
);
4434 * Called from notify_change.
4436 * We want to trap VFS attempts to truncate the file as soon as
4437 * possible. In particular, we want to make sure that when the VFS
4438 * shrinks i_size, we put the inode on the orphan list and modify
4439 * i_disksize immediately, so that during the subsequent flushing of
4440 * dirty pages and freeing of disk blocks, we can guarantee that any
4441 * commit will leave the blocks being flushed in an unused state on
4442 * disk. (On recovery, the inode will get truncated and the blocks will
4443 * be freed, so we have a strong guarantee that no future commit will
4444 * leave these blocks visible to the user.)
4446 * Another thing we have to assure is that if we are in ordered mode
4447 * and inode is still attached to the committing transaction, we must
4448 * we start writeout of all the dirty pages which are being truncated.
4449 * This way we are sure that all the data written in the previous
4450 * transaction are already on disk (truncate waits for pages under
4453 * Called with inode->i_mutex down.
4455 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
4457 struct inode
*inode
= dentry
->d_inode
;
4459 const unsigned int ia_valid
= attr
->ia_valid
;
4461 error
= inode_change_ok(inode
, attr
);
4465 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
4466 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
4469 /* (user+group)*(old+new) structure, inode write (sb,
4470 * inode block, ? - but truncate inode update has it) */
4471 handle
= ext4_journal_start(inode
, 2*(EXT4_QUOTA_INIT_BLOCKS(inode
->i_sb
)+
4472 EXT4_QUOTA_DEL_BLOCKS(inode
->i_sb
))+3);
4473 if (IS_ERR(handle
)) {
4474 error
= PTR_ERR(handle
);
4477 error
= DQUOT_TRANSFER(inode
, attr
) ? -EDQUOT
: 0;
4479 ext4_journal_stop(handle
);
4482 /* Update corresponding info in inode so that everything is in
4483 * one transaction */
4484 if (attr
->ia_valid
& ATTR_UID
)
4485 inode
->i_uid
= attr
->ia_uid
;
4486 if (attr
->ia_valid
& ATTR_GID
)
4487 inode
->i_gid
= attr
->ia_gid
;
4488 error
= ext4_mark_inode_dirty(handle
, inode
);
4489 ext4_journal_stop(handle
);
4492 if (attr
->ia_valid
& ATTR_SIZE
) {
4493 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
4494 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
4496 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
4503 if (S_ISREG(inode
->i_mode
) &&
4504 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
4507 handle
= ext4_journal_start(inode
, 3);
4508 if (IS_ERR(handle
)) {
4509 error
= PTR_ERR(handle
);
4513 error
= ext4_orphan_add(handle
, inode
);
4514 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
4515 rc
= ext4_mark_inode_dirty(handle
, inode
);
4518 ext4_journal_stop(handle
);
4520 if (ext4_should_order_data(inode
)) {
4521 error
= ext4_begin_ordered_truncate(inode
,
4524 /* Do as much error cleanup as possible */
4525 handle
= ext4_journal_start(inode
, 3);
4526 if (IS_ERR(handle
)) {
4527 ext4_orphan_del(NULL
, inode
);
4530 ext4_orphan_del(handle
, inode
);
4531 ext4_journal_stop(handle
);
4537 rc
= inode_setattr(inode
, attr
);
4539 /* If inode_setattr's call to ext4_truncate failed to get a
4540 * transaction handle at all, we need to clean up the in-core
4541 * orphan list manually. */
4543 ext4_orphan_del(NULL
, inode
);
4545 if (!rc
&& (ia_valid
& ATTR_MODE
))
4546 rc
= ext4_acl_chmod(inode
);
4549 ext4_std_error(inode
->i_sb
, error
);
4555 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
4558 struct inode
*inode
;
4559 unsigned long delalloc_blocks
;
4561 inode
= dentry
->d_inode
;
4562 generic_fillattr(inode
, stat
);
4565 * We can't update i_blocks if the block allocation is delayed
4566 * otherwise in the case of system crash before the real block
4567 * allocation is done, we will have i_blocks inconsistent with
4568 * on-disk file blocks.
4569 * We always keep i_blocks updated together with real
4570 * allocation. But to not confuse with user, stat
4571 * will return the blocks that include the delayed allocation
4572 * blocks for this file.
4574 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
4575 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
4576 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
4578 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
4582 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
4587 /* if nrblocks are contiguous */
4590 * With N contiguous data blocks, it need at most
4591 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
4592 * 2 dindirect blocks
4595 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4596 return indirects
+ 3;
4599 * if nrblocks are not contiguous, worse case, each block touch
4600 * a indirect block, and each indirect block touch a double indirect
4601 * block, plus a triple indirect block
4603 indirects
= nrblocks
* 2 + 1;
4607 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4609 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
4610 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
4611 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
4615 * Account for index blocks, block groups bitmaps and block group
4616 * descriptor blocks if modify datablocks and index blocks
4617 * worse case, the indexs blocks spread over different block groups
4619 * If datablocks are discontiguous, they are possible to spread over
4620 * different block groups too. If they are contiugous, with flexbg,
4621 * they could still across block group boundary.
4623 * Also account for superblock, inode, quota and xattr blocks
4625 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
4627 int groups
, gdpblocks
;
4632 * How many index blocks need to touch to modify nrblocks?
4633 * The "Chunk" flag indicating whether the nrblocks is
4634 * physically contiguous on disk
4636 * For Direct IO and fallocate, they calls get_block to allocate
4637 * one single extent at a time, so they could set the "Chunk" flag
4639 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
4644 * Now let's see how many group bitmaps and group descriptors need
4654 if (groups
> EXT4_SB(inode
->i_sb
)->s_groups_count
)
4655 groups
= EXT4_SB(inode
->i_sb
)->s_groups_count
;
4656 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
4657 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
4659 /* bitmaps and block group descriptor blocks */
4660 ret
+= groups
+ gdpblocks
;
4662 /* Blocks for super block, inode, quota and xattr blocks */
4663 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
4669 * Calulate the total number of credits to reserve to fit
4670 * the modification of a single pages into a single transaction,
4671 * which may include multiple chunks of block allocations.
4673 * This could be called via ext4_write_begin()
4675 * We need to consider the worse case, when
4676 * one new block per extent.
4678 int ext4_writepage_trans_blocks(struct inode
*inode
)
4680 int bpp
= ext4_journal_blocks_per_page(inode
);
4683 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
4685 /* Account for data blocks for journalled mode */
4686 if (ext4_should_journal_data(inode
))
4692 * Calculate the journal credits for a chunk of data modification.
4694 * This is called from DIO, fallocate or whoever calling
4695 * ext4_get_blocks_wrap() to map/allocate a chunk of contigous disk blocks.
4697 * journal buffers for data blocks are not included here, as DIO
4698 * and fallocate do no need to journal data buffers.
4700 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
4702 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
4706 * The caller must have previously called ext4_reserve_inode_write().
4707 * Give this, we know that the caller already has write access to iloc->bh.
4709 int ext4_mark_iloc_dirty(handle_t
*handle
,
4710 struct inode
*inode
, struct ext4_iloc
*iloc
)
4714 if (test_opt(inode
->i_sb
, I_VERSION
))
4715 inode_inc_iversion(inode
);
4717 /* the do_update_inode consumes one bh->b_count */
4720 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4721 err
= ext4_do_update_inode(handle
, inode
, iloc
);
4727 * On success, We end up with an outstanding reference count against
4728 * iloc->bh. This _must_ be cleaned up later.
4732 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
4733 struct ext4_iloc
*iloc
)
4737 err
= ext4_get_inode_loc(inode
, iloc
);
4739 BUFFER_TRACE(iloc
->bh
, "get_write_access");
4740 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
4747 ext4_std_error(inode
->i_sb
, err
);
4752 * Expand an inode by new_extra_isize bytes.
4753 * Returns 0 on success or negative error number on failure.
4755 static int ext4_expand_extra_isize(struct inode
*inode
,
4756 unsigned int new_extra_isize
,
4757 struct ext4_iloc iloc
,
4760 struct ext4_inode
*raw_inode
;
4761 struct ext4_xattr_ibody_header
*header
;
4762 struct ext4_xattr_entry
*entry
;
4764 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
4767 raw_inode
= ext4_raw_inode(&iloc
);
4769 header
= IHDR(inode
, raw_inode
);
4770 entry
= IFIRST(header
);
4772 /* No extended attributes present */
4773 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
4774 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
4775 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
4777 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
4781 /* try to expand with EAs present */
4782 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
4787 * What we do here is to mark the in-core inode as clean with respect to inode
4788 * dirtiness (it may still be data-dirty).
4789 * This means that the in-core inode may be reaped by prune_icache
4790 * without having to perform any I/O. This is a very good thing,
4791 * because *any* task may call prune_icache - even ones which
4792 * have a transaction open against a different journal.
4794 * Is this cheating? Not really. Sure, we haven't written the
4795 * inode out, but prune_icache isn't a user-visible syncing function.
4796 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4797 * we start and wait on commits.
4799 * Is this efficient/effective? Well, we're being nice to the system
4800 * by cleaning up our inodes proactively so they can be reaped
4801 * without I/O. But we are potentially leaving up to five seconds'
4802 * worth of inodes floating about which prune_icache wants us to
4803 * write out. One way to fix that would be to get prune_icache()
4804 * to do a write_super() to free up some memory. It has the desired
4807 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
4809 struct ext4_iloc iloc
;
4810 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
4811 static unsigned int mnt_count
;
4815 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
4816 if (EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
4817 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
4819 * We need extra buffer credits since we may write into EA block
4820 * with this same handle. If journal_extend fails, then it will
4821 * only result in a minor loss of functionality for that inode.
4822 * If this is felt to be critical, then e2fsck should be run to
4823 * force a large enough s_min_extra_isize.
4825 if ((jbd2_journal_extend(handle
,
4826 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
4827 ret
= ext4_expand_extra_isize(inode
,
4828 sbi
->s_want_extra_isize
,
4831 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
4833 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
4834 ext4_warning(inode
->i_sb
, __func__
,
4835 "Unable to expand inode %lu. Delete"
4836 " some EAs or run e2fsck.",
4839 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
4845 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
4850 * ext4_dirty_inode() is called from __mark_inode_dirty()
4852 * We're really interested in the case where a file is being extended.
4853 * i_size has been changed by generic_commit_write() and we thus need
4854 * to include the updated inode in the current transaction.
4856 * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
4857 * are allocated to the file.
4859 * If the inode is marked synchronous, we don't honour that here - doing
4860 * so would cause a commit on atime updates, which we don't bother doing.
4861 * We handle synchronous inodes at the highest possible level.
4863 void ext4_dirty_inode(struct inode
*inode
)
4865 handle_t
*current_handle
= ext4_journal_current_handle();
4868 handle
= ext4_journal_start(inode
, 2);
4871 if (current_handle
&&
4872 current_handle
->h_transaction
!= handle
->h_transaction
) {
4873 /* This task has a transaction open against a different fs */
4874 printk(KERN_EMERG
"%s: transactions do not match!\n",
4877 jbd_debug(5, "marking dirty. outer handle=%p\n",
4879 ext4_mark_inode_dirty(handle
, inode
);
4881 ext4_journal_stop(handle
);
4888 * Bind an inode's backing buffer_head into this transaction, to prevent
4889 * it from being flushed to disk early. Unlike
4890 * ext4_reserve_inode_write, this leaves behind no bh reference and
4891 * returns no iloc structure, so the caller needs to repeat the iloc
4892 * lookup to mark the inode dirty later.
4894 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
4896 struct ext4_iloc iloc
;
4900 err
= ext4_get_inode_loc(inode
, &iloc
);
4902 BUFFER_TRACE(iloc
.bh
, "get_write_access");
4903 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
4905 err
= ext4_journal_dirty_metadata(handle
,
4910 ext4_std_error(inode
->i_sb
, err
);
4915 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
4922 * We have to be very careful here: changing a data block's
4923 * journaling status dynamically is dangerous. If we write a
4924 * data block to the journal, change the status and then delete
4925 * that block, we risk forgetting to revoke the old log record
4926 * from the journal and so a subsequent replay can corrupt data.
4927 * So, first we make sure that the journal is empty and that
4928 * nobody is changing anything.
4931 journal
= EXT4_JOURNAL(inode
);
4932 if (is_journal_aborted(journal
))
4935 jbd2_journal_lock_updates(journal
);
4936 jbd2_journal_flush(journal
);
4939 * OK, there are no updates running now, and all cached data is
4940 * synced to disk. We are now in a completely consistent state
4941 * which doesn't have anything in the journal, and we know that
4942 * no filesystem updates are running, so it is safe to modify
4943 * the inode's in-core data-journaling state flag now.
4947 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
4949 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
4950 ext4_set_aops(inode
);
4952 jbd2_journal_unlock_updates(journal
);
4954 /* Finally we can mark the inode as dirty. */
4956 handle
= ext4_journal_start(inode
, 1);
4958 return PTR_ERR(handle
);
4960 err
= ext4_mark_inode_dirty(handle
, inode
);
4962 ext4_journal_stop(handle
);
4963 ext4_std_error(inode
->i_sb
, err
);
4968 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
4970 return !buffer_mapped(bh
);
4973 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct page
*page
)
4979 struct file
*file
= vma
->vm_file
;
4980 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
4981 struct address_space
*mapping
= inode
->i_mapping
;
4984 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
4985 * get i_mutex because we are already holding mmap_sem.
4987 down_read(&inode
->i_alloc_sem
);
4988 size
= i_size_read(inode
);
4989 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
4990 || !PageUptodate(page
)) {
4991 /* page got truncated from under us? */
4995 if (PageMappedToDisk(page
))
4998 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
4999 len
= size
& ~PAGE_CACHE_MASK
;
5001 len
= PAGE_CACHE_SIZE
;
5003 if (page_has_buffers(page
)) {
5004 /* return if we have all the buffers mapped */
5005 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5010 * OK, we need to fill the hole... Do write_begin write_end
5011 * to do block allocation/reservation.We are not holding
5012 * inode.i__mutex here. That allow * parallel write_begin,
5013 * write_end call. lock_page prevent this from happening
5014 * on the same page though
5016 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5017 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5020 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5021 len
, len
, page
, fsdata
);
5026 up_read(&inode
->i_alloc_sem
);