2 * linux/fs/ext4/inode.c
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
11 * linux/fs/minix/inode.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
15 * Goal-directed block allocation by Stephen Tweedie
16 * (sct@redhat.com), 1993, 1998
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 * 64-bit file support on 64-bit platforms by Jakub Jelinek
20 * (jj@sunsite.ms.mff.cuni.cz)
22 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
25 #include <linux/module.h>
27 #include <linux/time.h>
28 #include <linux/jbd2.h>
29 #include <linux/highuid.h>
30 #include <linux/pagemap.h>
31 #include <linux/quotaops.h>
32 #include <linux/string.h>
33 #include <linux/buffer_head.h>
34 #include <linux/writeback.h>
35 #include <linux/pagevec.h>
36 #include <linux/mpage.h>
37 #include <linux/namei.h>
38 #include <linux/uio.h>
39 #include <linux/bio.h>
40 #include <linux/workqueue.h>
42 #include "ext4_jbd2.h"
45 #include "ext4_extents.h"
47 #include <trace/events/ext4.h>
49 #define MPAGE_DA_EXTENT_TAIL 0x01
51 static inline int ext4_begin_ordered_truncate(struct inode
*inode
,
54 return jbd2_journal_begin_ordered_truncate(
55 EXT4_SB(inode
->i_sb
)->s_journal
,
56 &EXT4_I(inode
)->jinode
,
60 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
);
63 * Test whether an inode is a fast symlink.
65 static int ext4_inode_is_fast_symlink(struct inode
*inode
)
67 int ea_blocks
= EXT4_I(inode
)->i_file_acl
?
68 (inode
->i_sb
->s_blocksize
>> 9) : 0;
70 return (S_ISLNK(inode
->i_mode
) && inode
->i_blocks
- ea_blocks
== 0);
74 * The ext4 forget function must perform a revoke if we are freeing data
75 * which has been journaled. Metadata (eg. indirect blocks) must be
76 * revoked in all cases.
78 * "bh" may be NULL: a metadata block may have been freed from memory
79 * but there may still be a record of it in the journal, and that record
80 * still needs to be revoked.
82 * If the handle isn't valid we're not journaling, but we still need to
83 * call into ext4_journal_revoke() to put the buffer head.
85 int ext4_forget(handle_t
*handle
, int is_metadata
, struct inode
*inode
,
86 struct buffer_head
*bh
, ext4_fsblk_t blocknr
)
92 trace_ext4_forget(inode
, is_metadata
, blocknr
);
93 BUFFER_TRACE(bh
, "enter");
95 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
97 bh
, is_metadata
, inode
->i_mode
,
98 test_opt(inode
->i_sb
, DATA_FLAGS
));
100 /* Never use the revoke function if we are doing full data
101 * journaling: there is no need to, and a V1 superblock won't
102 * support it. Otherwise, only skip the revoke on un-journaled
105 if (test_opt(inode
->i_sb
, DATA_FLAGS
) == EXT4_MOUNT_JOURNAL_DATA
||
106 (!is_metadata
&& !ext4_should_journal_data(inode
))) {
108 BUFFER_TRACE(bh
, "call jbd2_journal_forget");
109 return ext4_journal_forget(handle
, bh
);
115 * data!=journal && (is_metadata || should_journal_data(inode))
117 BUFFER_TRACE(bh
, "call ext4_journal_revoke");
118 err
= ext4_journal_revoke(handle
, blocknr
, bh
);
120 ext4_abort(inode
->i_sb
, __func__
,
121 "error %d when attempting revoke", err
);
122 BUFFER_TRACE(bh
, "exit");
127 * Work out how many blocks we need to proceed with the next chunk of a
128 * truncate transaction.
130 static unsigned long blocks_for_truncate(struct inode
*inode
)
134 needed
= inode
->i_blocks
>> (inode
->i_sb
->s_blocksize_bits
- 9);
136 /* Give ourselves just enough room to cope with inodes in which
137 * i_blocks is corrupt: we've seen disk corruptions in the past
138 * which resulted in random data in an inode which looked enough
139 * like a regular file for ext4 to try to delete it. Things
140 * will go a bit crazy if that happens, but at least we should
141 * try not to panic the whole kernel. */
145 /* But we need to bound the transaction so we don't overflow the
147 if (needed
> EXT4_MAX_TRANS_DATA
)
148 needed
= EXT4_MAX_TRANS_DATA
;
150 return EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + needed
;
154 * Truncate transactions can be complex and absolutely huge. So we need to
155 * be able to restart the transaction at a conventient checkpoint to make
156 * sure we don't overflow the journal.
158 * start_transaction gets us a new handle for a truncate transaction,
159 * and extend_transaction tries to extend the existing one a bit. If
160 * extend fails, we need to propagate the failure up and restart the
161 * transaction in the top-level truncate loop. --sct
163 static handle_t
*start_transaction(struct inode
*inode
)
167 result
= ext4_journal_start(inode
, blocks_for_truncate(inode
));
171 ext4_std_error(inode
->i_sb
, PTR_ERR(result
));
176 * Try to extend this transaction for the purposes of truncation.
178 * Returns 0 if we managed to create more room. If we can't create more
179 * room, and the transaction must be restarted we return 1.
181 static int try_to_extend_transaction(handle_t
*handle
, struct inode
*inode
)
183 if (!ext4_handle_valid(handle
))
185 if (ext4_handle_has_enough_credits(handle
, EXT4_RESERVE_TRANS_BLOCKS
+1))
187 if (!ext4_journal_extend(handle
, blocks_for_truncate(inode
)))
193 * Restart the transaction associated with *handle. This does a commit,
194 * so before we call here everything must be consistently dirtied against
197 int ext4_truncate_restart_trans(handle_t
*handle
, struct inode
*inode
,
203 * Drop i_data_sem to avoid deadlock with ext4_get_blocks At this
204 * moment, get_block can be called only for blocks inside i_size since
205 * page cache has been already dropped and writes are blocked by
206 * i_mutex. So we can safely drop the i_data_sem here.
208 BUG_ON(EXT4_JOURNAL(inode
) == NULL
);
209 jbd_debug(2, "restarting handle %p\n", handle
);
210 up_write(&EXT4_I(inode
)->i_data_sem
);
211 ret
= ext4_journal_restart(handle
, blocks_for_truncate(inode
));
212 down_write(&EXT4_I(inode
)->i_data_sem
);
213 ext4_discard_preallocations(inode
);
219 * Called at the last iput() if i_nlink is zero.
221 void ext4_delete_inode(struct inode
*inode
)
226 if (ext4_should_order_data(inode
))
227 ext4_begin_ordered_truncate(inode
, 0);
228 truncate_inode_pages(&inode
->i_data
, 0);
230 if (is_bad_inode(inode
))
233 handle
= ext4_journal_start(inode
, blocks_for_truncate(inode
)+3);
234 if (IS_ERR(handle
)) {
235 ext4_std_error(inode
->i_sb
, PTR_ERR(handle
));
237 * If we're going to skip the normal cleanup, we still need to
238 * make sure that the in-core orphan linked list is properly
241 ext4_orphan_del(NULL
, inode
);
246 ext4_handle_sync(handle
);
248 err
= ext4_mark_inode_dirty(handle
, inode
);
250 ext4_warning(inode
->i_sb
, __func__
,
251 "couldn't mark inode dirty (err %d)", err
);
255 ext4_truncate(inode
);
258 * ext4_ext_truncate() doesn't reserve any slop when it
259 * restarts journal transactions; therefore there may not be
260 * enough credits left in the handle to remove the inode from
261 * the orphan list and set the dtime field.
263 if (!ext4_handle_has_enough_credits(handle
, 3)) {
264 err
= ext4_journal_extend(handle
, 3);
266 err
= ext4_journal_restart(handle
, 3);
268 ext4_warning(inode
->i_sb
, __func__
,
269 "couldn't extend journal (err %d)", err
);
271 ext4_journal_stop(handle
);
277 * Kill off the orphan record which ext4_truncate created.
278 * AKPM: I think this can be inside the above `if'.
279 * Note that ext4_orphan_del() has to be able to cope with the
280 * deletion of a non-existent orphan - this is because we don't
281 * know if ext4_truncate() actually created an orphan record.
282 * (Well, we could do this if we need to, but heck - it works)
284 ext4_orphan_del(handle
, inode
);
285 EXT4_I(inode
)->i_dtime
= get_seconds();
288 * One subtle ordering requirement: if anything has gone wrong
289 * (transaction abort, IO errors, whatever), then we can still
290 * do these next steps (the fs will already have been marked as
291 * having errors), but we can't free the inode if the mark_dirty
294 if (ext4_mark_inode_dirty(handle
, inode
))
295 /* If that failed, just do the required in-core inode clear. */
298 ext4_free_inode(handle
, inode
);
299 ext4_journal_stop(handle
);
302 clear_inode(inode
); /* We must guarantee clearing of inode... */
308 struct buffer_head
*bh
;
311 static inline void add_chain(Indirect
*p
, struct buffer_head
*bh
, __le32
*v
)
313 p
->key
= *(p
->p
= v
);
318 * ext4_block_to_path - parse the block number into array of offsets
319 * @inode: inode in question (we are only interested in its superblock)
320 * @i_block: block number to be parsed
321 * @offsets: array to store the offsets in
322 * @boundary: set this non-zero if the referred-to block is likely to be
323 * followed (on disk) by an indirect block.
325 * To store the locations of file's data ext4 uses a data structure common
326 * for UNIX filesystems - tree of pointers anchored in the inode, with
327 * data blocks at leaves and indirect blocks in intermediate nodes.
328 * This function translates the block number into path in that tree -
329 * return value is the path length and @offsets[n] is the offset of
330 * pointer to (n+1)th node in the nth one. If @block is out of range
331 * (negative or too large) warning is printed and zero returned.
333 * Note: function doesn't find node addresses, so no IO is needed. All
334 * we need to know is the capacity of indirect blocks (taken from the
339 * Portability note: the last comparison (check that we fit into triple
340 * indirect block) is spelled differently, because otherwise on an
341 * architecture with 32-bit longs and 8Kb pages we might get into trouble
342 * if our filesystem had 8Kb blocks. We might use long long, but that would
343 * kill us on x86. Oh, well, at least the sign propagation does not matter -
344 * i_block would have to be negative in the very beginning, so we would not
348 static int ext4_block_to_path(struct inode
*inode
,
350 ext4_lblk_t offsets
[4], int *boundary
)
352 int ptrs
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
353 int ptrs_bits
= EXT4_ADDR_PER_BLOCK_BITS(inode
->i_sb
);
354 const long direct_blocks
= EXT4_NDIR_BLOCKS
,
355 indirect_blocks
= ptrs
,
356 double_blocks
= (1 << (ptrs_bits
* 2));
360 if (i_block
< direct_blocks
) {
361 offsets
[n
++] = i_block
;
362 final
= direct_blocks
;
363 } else if ((i_block
-= direct_blocks
) < indirect_blocks
) {
364 offsets
[n
++] = EXT4_IND_BLOCK
;
365 offsets
[n
++] = i_block
;
367 } else if ((i_block
-= indirect_blocks
) < double_blocks
) {
368 offsets
[n
++] = EXT4_DIND_BLOCK
;
369 offsets
[n
++] = i_block
>> ptrs_bits
;
370 offsets
[n
++] = i_block
& (ptrs
- 1);
372 } else if (((i_block
-= double_blocks
) >> (ptrs_bits
* 2)) < ptrs
) {
373 offsets
[n
++] = EXT4_TIND_BLOCK
;
374 offsets
[n
++] = i_block
>> (ptrs_bits
* 2);
375 offsets
[n
++] = (i_block
>> ptrs_bits
) & (ptrs
- 1);
376 offsets
[n
++] = i_block
& (ptrs
- 1);
379 ext4_warning(inode
->i_sb
, "ext4_block_to_path",
380 "block %lu > max in inode %lu",
381 i_block
+ direct_blocks
+
382 indirect_blocks
+ double_blocks
, inode
->i_ino
);
385 *boundary
= final
- 1 - (i_block
& (ptrs
- 1));
389 static int __ext4_check_blockref(const char *function
, struct inode
*inode
,
390 __le32
*p
, unsigned int max
)
395 while (bref
< p
+max
) {
396 blk
= le32_to_cpu(*bref
++);
398 unlikely(!ext4_data_block_valid(EXT4_SB(inode
->i_sb
),
400 ext4_error(inode
->i_sb
, function
,
401 "invalid block reference %u "
402 "in inode #%lu", blk
, inode
->i_ino
);
410 #define ext4_check_indirect_blockref(inode, bh) \
411 __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data, \
412 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
414 #define ext4_check_inode_blockref(inode) \
415 __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data, \
419 * ext4_get_branch - read the chain of indirect blocks leading to data
420 * @inode: inode in question
421 * @depth: depth of the chain (1 - direct pointer, etc.)
422 * @offsets: offsets of pointers in inode/indirect blocks
423 * @chain: place to store the result
424 * @err: here we store the error value
426 * Function fills the array of triples <key, p, bh> and returns %NULL
427 * if everything went OK or the pointer to the last filled triple
428 * (incomplete one) otherwise. Upon the return chain[i].key contains
429 * the number of (i+1)-th block in the chain (as it is stored in memory,
430 * i.e. little-endian 32-bit), chain[i].p contains the address of that
431 * number (it points into struct inode for i==0 and into the bh->b_data
432 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
433 * block for i>0 and NULL for i==0. In other words, it holds the block
434 * numbers of the chain, addresses they were taken from (and where we can
435 * verify that chain did not change) and buffer_heads hosting these
438 * Function stops when it stumbles upon zero pointer (absent block)
439 * (pointer to last triple returned, *@err == 0)
440 * or when it gets an IO error reading an indirect block
441 * (ditto, *@err == -EIO)
442 * or when it reads all @depth-1 indirect blocks successfully and finds
443 * the whole chain, all way to the data (returns %NULL, *err == 0).
445 * Need to be called with
446 * down_read(&EXT4_I(inode)->i_data_sem)
448 static Indirect
*ext4_get_branch(struct inode
*inode
, int depth
,
449 ext4_lblk_t
*offsets
,
450 Indirect chain
[4], int *err
)
452 struct super_block
*sb
= inode
->i_sb
;
454 struct buffer_head
*bh
;
457 /* i_data is not going away, no lock needed */
458 add_chain(chain
, NULL
, EXT4_I(inode
)->i_data
+ *offsets
);
462 bh
= sb_getblk(sb
, le32_to_cpu(p
->key
));
466 if (!bh_uptodate_or_lock(bh
)) {
467 if (bh_submit_read(bh
) < 0) {
471 /* validate block references */
472 if (ext4_check_indirect_blockref(inode
, bh
)) {
478 add_chain(++p
, bh
, (__le32
*)bh
->b_data
+ *++offsets
);
492 * ext4_find_near - find a place for allocation with sufficient locality
494 * @ind: descriptor of indirect block.
496 * This function returns the preferred place for block allocation.
497 * It is used when heuristic for sequential allocation fails.
499 * + if there is a block to the left of our position - allocate near it.
500 * + if pointer will live in indirect block - allocate near that block.
501 * + if pointer will live in inode - allocate in the same
504 * In the latter case we colour the starting block by the callers PID to
505 * prevent it from clashing with concurrent allocations for a different inode
506 * in the same block group. The PID is used here so that functionally related
507 * files will be close-by on-disk.
509 * Caller must make sure that @ind is valid and will stay that way.
511 static ext4_fsblk_t
ext4_find_near(struct inode
*inode
, Indirect
*ind
)
513 struct ext4_inode_info
*ei
= EXT4_I(inode
);
514 __le32
*start
= ind
->bh
? (__le32
*) ind
->bh
->b_data
: ei
->i_data
;
516 ext4_fsblk_t bg_start
;
517 ext4_fsblk_t last_block
;
518 ext4_grpblk_t colour
;
519 ext4_group_t block_group
;
520 int flex_size
= ext4_flex_bg_size(EXT4_SB(inode
->i_sb
));
522 /* Try to find previous block */
523 for (p
= ind
->p
- 1; p
>= start
; p
--) {
525 return le32_to_cpu(*p
);
528 /* No such thing, so let's try location of indirect block */
530 return ind
->bh
->b_blocknr
;
533 * It is going to be referred to from the inode itself? OK, just put it
534 * into the same cylinder group then.
536 block_group
= ei
->i_block_group
;
537 if (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) {
538 block_group
&= ~(flex_size
-1);
539 if (S_ISREG(inode
->i_mode
))
542 bg_start
= ext4_group_first_block_no(inode
->i_sb
, block_group
);
543 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
546 * If we are doing delayed allocation, we don't need take
547 * colour into account.
549 if (test_opt(inode
->i_sb
, DELALLOC
))
552 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
553 colour
= (current
->pid
% 16) *
554 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
556 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
557 return bg_start
+ colour
;
561 * ext4_find_goal - find a preferred place for allocation.
563 * @block: block we want
564 * @partial: pointer to the last triple within a chain
566 * Normally this function find the preferred place for block allocation,
568 * Because this is only used for non-extent files, we limit the block nr
571 static ext4_fsblk_t
ext4_find_goal(struct inode
*inode
, ext4_lblk_t block
,
577 * XXX need to get goal block from mballoc's data structures
580 goal
= ext4_find_near(inode
, partial
);
581 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
586 * ext4_blks_to_allocate: Look up the block map and count the number
587 * of direct blocks need to be allocated for the given branch.
589 * @branch: chain of indirect blocks
590 * @k: number of blocks need for indirect blocks
591 * @blks: number of data blocks to be mapped.
592 * @blocks_to_boundary: the offset in the indirect block
594 * return the total number of blocks to be allocate, including the
595 * direct and indirect blocks.
597 static int ext4_blks_to_allocate(Indirect
*branch
, int k
, unsigned int blks
,
598 int blocks_to_boundary
)
600 unsigned int count
= 0;
603 * Simple case, [t,d]Indirect block(s) has not allocated yet
604 * then it's clear blocks on that path have not allocated
607 /* right now we don't handle cross boundary allocation */
608 if (blks
< blocks_to_boundary
+ 1)
611 count
+= blocks_to_boundary
+ 1;
616 while (count
< blks
&& count
<= blocks_to_boundary
&&
617 le32_to_cpu(*(branch
[0].p
+ count
)) == 0) {
624 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
625 * @indirect_blks: the number of blocks need to allocate for indirect
628 * @new_blocks: on return it will store the new block numbers for
629 * the indirect blocks(if needed) and the first direct block,
630 * @blks: on return it will store the total number of allocated
633 static int ext4_alloc_blocks(handle_t
*handle
, struct inode
*inode
,
634 ext4_lblk_t iblock
, ext4_fsblk_t goal
,
635 int indirect_blks
, int blks
,
636 ext4_fsblk_t new_blocks
[4], int *err
)
638 struct ext4_allocation_request ar
;
640 unsigned long count
= 0, blk_allocated
= 0;
642 ext4_fsblk_t current_block
= 0;
646 * Here we try to allocate the requested multiple blocks at once,
647 * on a best-effort basis.
648 * To build a branch, we should allocate blocks for
649 * the indirect blocks(if not allocated yet), and at least
650 * the first direct block of this branch. That's the
651 * minimum number of blocks need to allocate(required)
653 /* first we try to allocate the indirect blocks */
654 target
= indirect_blks
;
657 /* allocating blocks for indirect blocks and direct blocks */
658 current_block
= ext4_new_meta_blocks(handle
, inode
,
663 BUG_ON(current_block
+ count
> EXT4_MAX_BLOCK_FILE_PHYS
);
666 /* allocate blocks for indirect blocks */
667 while (index
< indirect_blks
&& count
) {
668 new_blocks
[index
++] = current_block
++;
673 * save the new block number
674 * for the first direct block
676 new_blocks
[index
] = current_block
;
677 printk(KERN_INFO
"%s returned more blocks than "
678 "requested\n", __func__
);
684 target
= blks
- count
;
685 blk_allocated
= count
;
688 /* Now allocate data blocks */
689 memset(&ar
, 0, sizeof(ar
));
694 if (S_ISREG(inode
->i_mode
))
695 /* enable in-core preallocation only for regular files */
696 ar
.flags
= EXT4_MB_HINT_DATA
;
698 current_block
= ext4_mb_new_blocks(handle
, &ar
, err
);
699 BUG_ON(current_block
+ ar
.len
> EXT4_MAX_BLOCK_FILE_PHYS
);
701 if (*err
&& (target
== blks
)) {
703 * if the allocation failed and we didn't allocate
709 if (target
== blks
) {
711 * save the new block number
712 * for the first direct block
714 new_blocks
[index
] = current_block
;
716 blk_allocated
+= ar
.len
;
719 /* total number of blocks allocated for direct blocks */
724 for (i
= 0; i
< index
; i
++)
725 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
730 * ext4_alloc_branch - allocate and set up a chain of blocks.
732 * @indirect_blks: number of allocated indirect blocks
733 * @blks: number of allocated direct blocks
734 * @offsets: offsets (in the blocks) to store the pointers to next.
735 * @branch: place to store the chain in.
737 * This function allocates blocks, zeroes out all but the last one,
738 * links them into chain and (if we are synchronous) writes them to disk.
739 * In other words, it prepares a branch that can be spliced onto the
740 * inode. It stores the information about that chain in the branch[], in
741 * the same format as ext4_get_branch() would do. We are calling it after
742 * we had read the existing part of chain and partial points to the last
743 * triple of that (one with zero ->key). Upon the exit we have the same
744 * picture as after the successful ext4_get_block(), except that in one
745 * place chain is disconnected - *branch->p is still zero (we did not
746 * set the last link), but branch->key contains the number that should
747 * be placed into *branch->p to fill that gap.
749 * If allocation fails we free all blocks we've allocated (and forget
750 * their buffer_heads) and return the error value the from failed
751 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
752 * as described above and return 0.
754 static int ext4_alloc_branch(handle_t
*handle
, struct inode
*inode
,
755 ext4_lblk_t iblock
, int indirect_blks
,
756 int *blks
, ext4_fsblk_t goal
,
757 ext4_lblk_t
*offsets
, Indirect
*branch
)
759 int blocksize
= inode
->i_sb
->s_blocksize
;
762 struct buffer_head
*bh
;
764 ext4_fsblk_t new_blocks
[4];
765 ext4_fsblk_t current_block
;
767 num
= ext4_alloc_blocks(handle
, inode
, iblock
, goal
, indirect_blks
,
768 *blks
, new_blocks
, &err
);
772 branch
[0].key
= cpu_to_le32(new_blocks
[0]);
774 * metadata blocks and data blocks are allocated.
776 for (n
= 1; n
<= indirect_blks
; n
++) {
778 * Get buffer_head for parent block, zero it out
779 * and set the pointer to new one, then send
782 bh
= sb_getblk(inode
->i_sb
, new_blocks
[n
-1]);
785 BUFFER_TRACE(bh
, "call get_create_access");
786 err
= ext4_journal_get_create_access(handle
, bh
);
788 /* Don't brelse(bh) here; it's done in
789 * ext4_journal_forget() below */
794 memset(bh
->b_data
, 0, blocksize
);
795 branch
[n
].p
= (__le32
*) bh
->b_data
+ offsets
[n
];
796 branch
[n
].key
= cpu_to_le32(new_blocks
[n
]);
797 *branch
[n
].p
= branch
[n
].key
;
798 if (n
== indirect_blks
) {
799 current_block
= new_blocks
[n
];
801 * End of chain, update the last new metablock of
802 * the chain to point to the new allocated
803 * data blocks numbers
805 for (i
= 1; i
< num
; i
++)
806 *(branch
[n
].p
+ i
) = cpu_to_le32(++current_block
);
808 BUFFER_TRACE(bh
, "marking uptodate");
809 set_buffer_uptodate(bh
);
812 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
813 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
820 /* Allocation failed, free what we already allocated */
821 for (i
= 1; i
<= n
; i
++) {
822 BUFFER_TRACE(branch
[i
].bh
, "call jbd2_journal_forget");
823 ext4_journal_forget(handle
, branch
[i
].bh
);
825 for (i
= 0; i
< indirect_blks
; i
++)
826 ext4_free_blocks(handle
, inode
, new_blocks
[i
], 1, 0);
828 ext4_free_blocks(handle
, inode
, new_blocks
[i
], num
, 0);
834 * ext4_splice_branch - splice the allocated branch onto inode.
836 * @block: (logical) number of block we are adding
837 * @chain: chain of indirect blocks (with a missing link - see
839 * @where: location of missing link
840 * @num: number of indirect blocks we are adding
841 * @blks: number of direct blocks we are adding
843 * This function fills the missing link and does all housekeeping needed in
844 * inode (->i_blocks, etc.). In case of success we end up with the full
845 * chain to new block and return 0.
847 static int ext4_splice_branch(handle_t
*handle
, struct inode
*inode
,
848 ext4_lblk_t block
, Indirect
*where
, int num
,
853 ext4_fsblk_t current_block
;
856 * If we're splicing into a [td]indirect block (as opposed to the
857 * inode) then we need to get write access to the [td]indirect block
861 BUFFER_TRACE(where
->bh
, "get_write_access");
862 err
= ext4_journal_get_write_access(handle
, where
->bh
);
868 *where
->p
= where
->key
;
871 * Update the host buffer_head or inode to point to more just allocated
872 * direct blocks blocks
874 if (num
== 0 && blks
> 1) {
875 current_block
= le32_to_cpu(where
->key
) + 1;
876 for (i
= 1; i
< blks
; i
++)
877 *(where
->p
+ i
) = cpu_to_le32(current_block
++);
880 /* We are done with atomic stuff, now do the rest of housekeeping */
881 /* had we spliced it onto indirect block? */
884 * If we spliced it onto an indirect block, we haven't
885 * altered the inode. Note however that if it is being spliced
886 * onto an indirect block at the very end of the file (the
887 * file is growing) then we *will* alter the inode to reflect
888 * the new i_size. But that is not done here - it is done in
889 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
891 jbd_debug(5, "splicing indirect only\n");
892 BUFFER_TRACE(where
->bh
, "call ext4_handle_dirty_metadata");
893 err
= ext4_handle_dirty_metadata(handle
, inode
, where
->bh
);
898 * OK, we spliced it into the inode itself on a direct block.
900 ext4_mark_inode_dirty(handle
, inode
);
901 jbd_debug(5, "splicing direct\n");
906 for (i
= 1; i
<= num
; i
++) {
907 BUFFER_TRACE(where
[i
].bh
, "call jbd2_journal_forget");
908 ext4_journal_forget(handle
, where
[i
].bh
);
909 ext4_free_blocks(handle
, inode
,
910 le32_to_cpu(where
[i
-1].key
), 1, 0);
912 ext4_free_blocks(handle
, inode
, le32_to_cpu(where
[num
].key
), blks
, 0);
918 * The ext4_ind_get_blocks() function handles non-extents inodes
919 * (i.e., using the traditional indirect/double-indirect i_blocks
920 * scheme) for ext4_get_blocks().
922 * Allocation strategy is simple: if we have to allocate something, we will
923 * have to go the whole way to leaf. So let's do it before attaching anything
924 * to tree, set linkage between the newborn blocks, write them if sync is
925 * required, recheck the path, free and repeat if check fails, otherwise
926 * set the last missing link (that will protect us from any truncate-generated
927 * removals - all blocks on the path are immune now) and possibly force the
928 * write on the parent block.
929 * That has a nice additional property: no special recovery from the failed
930 * allocations is needed - we simply release blocks and do not touch anything
931 * reachable from inode.
933 * `handle' can be NULL if create == 0.
935 * return > 0, # of blocks mapped or allocated.
936 * return = 0, if plain lookup failed.
937 * return < 0, error case.
939 * The ext4_ind_get_blocks() function should be called with
940 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
941 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
942 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
945 static int ext4_ind_get_blocks(handle_t
*handle
, struct inode
*inode
,
946 ext4_lblk_t iblock
, unsigned int maxblocks
,
947 struct buffer_head
*bh_result
,
951 ext4_lblk_t offsets
[4];
956 int blocks_to_boundary
= 0;
959 ext4_fsblk_t first_block
= 0;
961 J_ASSERT(!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
));
962 J_ASSERT(handle
!= NULL
|| (flags
& EXT4_GET_BLOCKS_CREATE
) == 0);
963 depth
= ext4_block_to_path(inode
, iblock
, offsets
,
964 &blocks_to_boundary
);
969 partial
= ext4_get_branch(inode
, depth
, offsets
, chain
, &err
);
971 /* Simplest case - block found, no allocation needed */
973 first_block
= le32_to_cpu(chain
[depth
- 1].key
);
974 clear_buffer_new(bh_result
);
977 while (count
< maxblocks
&& count
<= blocks_to_boundary
) {
980 blk
= le32_to_cpu(*(chain
[depth
-1].p
+ count
));
982 if (blk
== first_block
+ count
)
990 /* Next simple case - plain lookup or failed read of indirect block */
991 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0 || err
== -EIO
)
995 * Okay, we need to do block allocation.
997 goal
= ext4_find_goal(inode
, iblock
, partial
);
999 /* the number of blocks need to allocate for [d,t]indirect blocks */
1000 indirect_blks
= (chain
+ depth
) - partial
- 1;
1003 * Next look up the indirect map to count the totoal number of
1004 * direct blocks to allocate for this branch.
1006 count
= ext4_blks_to_allocate(partial
, indirect_blks
,
1007 maxblocks
, blocks_to_boundary
);
1009 * Block out ext4_truncate while we alter the tree
1011 err
= ext4_alloc_branch(handle
, inode
, iblock
, indirect_blks
,
1013 offsets
+ (partial
- chain
), partial
);
1016 * The ext4_splice_branch call will free and forget any buffers
1017 * on the new chain if there is a failure, but that risks using
1018 * up transaction credits, especially for bitmaps where the
1019 * credits cannot be returned. Can we handle this somehow? We
1020 * may need to return -EAGAIN upwards in the worst case. --sct
1023 err
= ext4_splice_branch(handle
, inode
, iblock
,
1024 partial
, indirect_blks
, count
);
1028 set_buffer_new(bh_result
);
1030 map_bh(bh_result
, inode
->i_sb
, le32_to_cpu(chain
[depth
-1].key
));
1031 if (count
> blocks_to_boundary
)
1032 set_buffer_boundary(bh_result
);
1034 /* Clean up and exit */
1035 partial
= chain
+ depth
- 1; /* the whole chain */
1037 while (partial
> chain
) {
1038 BUFFER_TRACE(partial
->bh
, "call brelse");
1039 brelse(partial
->bh
);
1042 BUFFER_TRACE(bh_result
, "returned");
1047 qsize_t
ext4_get_reserved_space(struct inode
*inode
)
1049 unsigned long long total
;
1051 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1052 total
= EXT4_I(inode
)->i_reserved_data_blocks
+
1053 EXT4_I(inode
)->i_reserved_meta_blocks
;
1054 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1059 * Calculate the number of metadata blocks need to reserve
1060 * to allocate @blocks for non extent file based file
1062 static int ext4_indirect_calc_metadata_amount(struct inode
*inode
, int blocks
)
1064 int icap
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
1065 int ind_blks
, dind_blks
, tind_blks
;
1067 /* number of new indirect blocks needed */
1068 ind_blks
= (blocks
+ icap
- 1) / icap
;
1070 dind_blks
= (ind_blks
+ icap
- 1) / icap
;
1074 return ind_blks
+ dind_blks
+ tind_blks
;
1078 * Calculate the number of metadata blocks need to reserve
1079 * to allocate given number of blocks
1081 static int ext4_calc_metadata_amount(struct inode
*inode
, int blocks
)
1086 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
1087 return ext4_ext_calc_metadata_amount(inode
, blocks
);
1089 return ext4_indirect_calc_metadata_amount(inode
, blocks
);
1092 static void ext4_da_update_reserve_space(struct inode
*inode
, int used
)
1094 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1095 int total
, mdb
, mdb_free
;
1097 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1098 /* recalculate the number of metablocks still need to be reserved */
1099 total
= EXT4_I(inode
)->i_reserved_data_blocks
- used
;
1100 mdb
= ext4_calc_metadata_amount(inode
, total
);
1102 /* figure out how many metablocks to release */
1103 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1104 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1107 /* Account for allocated meta_blocks */
1108 mdb_free
-= EXT4_I(inode
)->i_allocated_meta_blocks
;
1110 /* update fs dirty blocks counter */
1111 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, mdb_free
);
1112 EXT4_I(inode
)->i_allocated_meta_blocks
= 0;
1113 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1116 /* update per-inode reservations */
1117 BUG_ON(used
> EXT4_I(inode
)->i_reserved_data_blocks
);
1118 EXT4_I(inode
)->i_reserved_data_blocks
-= used
;
1119 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1122 * free those over-booking quota for metadata blocks
1125 vfs_dq_release_reservation_block(inode
, mdb_free
);
1128 * If we have done all the pending block allocations and if
1129 * there aren't any writers on the inode, we can discard the
1130 * inode's preallocations.
1132 if (!total
&& (atomic_read(&inode
->i_writecount
) == 0))
1133 ext4_discard_preallocations(inode
);
1136 static int check_block_validity(struct inode
*inode
, const char *msg
,
1137 sector_t logical
, sector_t phys
, int len
)
1139 if (!ext4_data_block_valid(EXT4_SB(inode
->i_sb
), phys
, len
)) {
1140 ext4_error(inode
->i_sb
, msg
,
1141 "inode #%lu logical block %llu mapped to %llu "
1142 "(size %d)", inode
->i_ino
,
1143 (unsigned long long) logical
,
1144 (unsigned long long) phys
, len
);
1151 * Return the number of contiguous dirty pages in a given inode
1152 * starting at page frame idx.
1154 static pgoff_t
ext4_num_dirty_pages(struct inode
*inode
, pgoff_t idx
,
1155 unsigned int max_pages
)
1157 struct address_space
*mapping
= inode
->i_mapping
;
1159 struct pagevec pvec
;
1161 int i
, nr_pages
, done
= 0;
1165 pagevec_init(&pvec
, 0);
1168 nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
1169 PAGECACHE_TAG_DIRTY
,
1170 (pgoff_t
)PAGEVEC_SIZE
);
1173 for (i
= 0; i
< nr_pages
; i
++) {
1174 struct page
*page
= pvec
.pages
[i
];
1175 struct buffer_head
*bh
, *head
;
1178 if (unlikely(page
->mapping
!= mapping
) ||
1180 PageWriteback(page
) ||
1181 page
->index
!= idx
) {
1186 if (page_has_buffers(page
)) {
1187 bh
= head
= page_buffers(page
);
1189 if (!buffer_delay(bh
) &&
1190 !buffer_unwritten(bh
))
1192 bh
= bh
->b_this_page
;
1193 } while (!done
&& (bh
!= head
));
1200 if (num
>= max_pages
)
1203 pagevec_release(&pvec
);
1209 * The ext4_get_blocks() function tries to look up the requested blocks,
1210 * and returns if the blocks are already mapped.
1212 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1213 * and store the allocated blocks in the result buffer head and mark it
1216 * If file type is extents based, it will call ext4_ext_get_blocks(),
1217 * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
1220 * On success, it returns the number of blocks being mapped or allocate.
1221 * if create==0 and the blocks are pre-allocated and uninitialized block,
1222 * the result buffer head is unmapped. If the create ==1, it will make sure
1223 * the buffer head is mapped.
1225 * It returns 0 if plain look up failed (blocks have not been allocated), in
1226 * that casem, buffer head is unmapped
1228 * It returns the error in case of allocation failure.
1230 int ext4_get_blocks(handle_t
*handle
, struct inode
*inode
, sector_t block
,
1231 unsigned int max_blocks
, struct buffer_head
*bh
,
1236 clear_buffer_mapped(bh
);
1237 clear_buffer_unwritten(bh
);
1239 ext_debug("ext4_get_blocks(): inode %lu, flag %d, max_blocks %u,"
1240 "logical block %lu\n", inode
->i_ino
, flags
, max_blocks
,
1241 (unsigned long)block
);
1243 * Try to see if we can get the block without requesting a new
1244 * file system block.
1246 down_read((&EXT4_I(inode
)->i_data_sem
));
1247 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1248 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1251 retval
= ext4_ind_get_blocks(handle
, inode
, block
, max_blocks
,
1254 up_read((&EXT4_I(inode
)->i_data_sem
));
1256 if (retval
> 0 && buffer_mapped(bh
)) {
1257 int ret
= check_block_validity(inode
, "file system corruption",
1258 block
, bh
->b_blocknr
, retval
);
1263 /* If it is only a block(s) look up */
1264 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0)
1268 * Returns if the blocks have already allocated
1270 * Note that if blocks have been preallocated
1271 * ext4_ext_get_block() returns th create = 0
1272 * with buffer head unmapped.
1274 if (retval
> 0 && buffer_mapped(bh
))
1278 * When we call get_blocks without the create flag, the
1279 * BH_Unwritten flag could have gotten set if the blocks
1280 * requested were part of a uninitialized extent. We need to
1281 * clear this flag now that we are committed to convert all or
1282 * part of the uninitialized extent to be an initialized
1283 * extent. This is because we need to avoid the combination
1284 * of BH_Unwritten and BH_Mapped flags being simultaneously
1285 * set on the buffer_head.
1287 clear_buffer_unwritten(bh
);
1290 * New blocks allocate and/or writing to uninitialized extent
1291 * will possibly result in updating i_data, so we take
1292 * the write lock of i_data_sem, and call get_blocks()
1293 * with create == 1 flag.
1295 down_write((&EXT4_I(inode
)->i_data_sem
));
1298 * if the caller is from delayed allocation writeout path
1299 * we have already reserved fs blocks for allocation
1300 * let the underlying get_block() function know to
1301 * avoid double accounting
1303 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1304 EXT4_I(inode
)->i_delalloc_reserved_flag
= 1;
1306 * We need to check for EXT4 here because migrate
1307 * could have changed the inode type in between
1309 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
1310 retval
= ext4_ext_get_blocks(handle
, inode
, block
, max_blocks
,
1313 retval
= ext4_ind_get_blocks(handle
, inode
, block
,
1314 max_blocks
, bh
, flags
);
1316 if (retval
> 0 && buffer_new(bh
)) {
1318 * We allocated new blocks which will result in
1319 * i_data's format changing. Force the migrate
1320 * to fail by clearing migrate flags
1322 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_EXT_MIGRATE
;
1326 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
1327 EXT4_I(inode
)->i_delalloc_reserved_flag
= 0;
1330 * Update reserved blocks/metadata blocks after successful
1331 * block allocation which had been deferred till now.
1333 if ((retval
> 0) && (flags
& EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
))
1334 ext4_da_update_reserve_space(inode
, retval
);
1336 up_write((&EXT4_I(inode
)->i_data_sem
));
1337 if (retval
> 0 && buffer_mapped(bh
)) {
1338 int ret
= check_block_validity(inode
, "file system "
1339 "corruption after allocation",
1340 block
, bh
->b_blocknr
, retval
);
1347 /* Maximum number of blocks we map for direct IO at once. */
1348 #define DIO_MAX_BLOCKS 4096
1350 int ext4_get_block(struct inode
*inode
, sector_t iblock
,
1351 struct buffer_head
*bh_result
, int create
)
1353 handle_t
*handle
= ext4_journal_current_handle();
1354 int ret
= 0, started
= 0;
1355 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
1358 if (create
&& !handle
) {
1359 /* Direct IO write... */
1360 if (max_blocks
> DIO_MAX_BLOCKS
)
1361 max_blocks
= DIO_MAX_BLOCKS
;
1362 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
1363 handle
= ext4_journal_start(inode
, dio_credits
);
1364 if (IS_ERR(handle
)) {
1365 ret
= PTR_ERR(handle
);
1371 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
1372 create
? EXT4_GET_BLOCKS_CREATE
: 0);
1374 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
1378 ext4_journal_stop(handle
);
1384 * `handle' can be NULL if create is zero
1386 struct buffer_head
*ext4_getblk(handle_t
*handle
, struct inode
*inode
,
1387 ext4_lblk_t block
, int create
, int *errp
)
1389 struct buffer_head dummy
;
1393 J_ASSERT(handle
!= NULL
|| create
== 0);
1396 dummy
.b_blocknr
= -1000;
1397 buffer_trace_init(&dummy
.b_history
);
1399 flags
|= EXT4_GET_BLOCKS_CREATE
;
1400 err
= ext4_get_blocks(handle
, inode
, block
, 1, &dummy
, flags
);
1402 * ext4_get_blocks() returns number of blocks mapped. 0 in
1411 if (!err
&& buffer_mapped(&dummy
)) {
1412 struct buffer_head
*bh
;
1413 bh
= sb_getblk(inode
->i_sb
, dummy
.b_blocknr
);
1418 if (buffer_new(&dummy
)) {
1419 J_ASSERT(create
!= 0);
1420 J_ASSERT(handle
!= NULL
);
1423 * Now that we do not always journal data, we should
1424 * keep in mind whether this should always journal the
1425 * new buffer as metadata. For now, regular file
1426 * writes use ext4_get_block instead, so it's not a
1430 BUFFER_TRACE(bh
, "call get_create_access");
1431 fatal
= ext4_journal_get_create_access(handle
, bh
);
1432 if (!fatal
&& !buffer_uptodate(bh
)) {
1433 memset(bh
->b_data
, 0, inode
->i_sb
->s_blocksize
);
1434 set_buffer_uptodate(bh
);
1437 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
1438 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1442 BUFFER_TRACE(bh
, "not a new buffer");
1455 struct buffer_head
*ext4_bread(handle_t
*handle
, struct inode
*inode
,
1456 ext4_lblk_t block
, int create
, int *err
)
1458 struct buffer_head
*bh
;
1460 bh
= ext4_getblk(handle
, inode
, block
, create
, err
);
1463 if (buffer_uptodate(bh
))
1465 ll_rw_block(READ_META
, 1, &bh
);
1467 if (buffer_uptodate(bh
))
1474 static int walk_page_buffers(handle_t
*handle
,
1475 struct buffer_head
*head
,
1479 int (*fn
)(handle_t
*handle
,
1480 struct buffer_head
*bh
))
1482 struct buffer_head
*bh
;
1483 unsigned block_start
, block_end
;
1484 unsigned blocksize
= head
->b_size
;
1486 struct buffer_head
*next
;
1488 for (bh
= head
, block_start
= 0;
1489 ret
== 0 && (bh
!= head
|| !block_start
);
1490 block_start
= block_end
, bh
= next
) {
1491 next
= bh
->b_this_page
;
1492 block_end
= block_start
+ blocksize
;
1493 if (block_end
<= from
|| block_start
>= to
) {
1494 if (partial
&& !buffer_uptodate(bh
))
1498 err
= (*fn
)(handle
, bh
);
1506 * To preserve ordering, it is essential that the hole instantiation and
1507 * the data write be encapsulated in a single transaction. We cannot
1508 * close off a transaction and start a new one between the ext4_get_block()
1509 * and the commit_write(). So doing the jbd2_journal_start at the start of
1510 * prepare_write() is the right place.
1512 * Also, this function can nest inside ext4_writepage() ->
1513 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1514 * has generated enough buffer credits to do the whole page. So we won't
1515 * block on the journal in that case, which is good, because the caller may
1518 * By accident, ext4 can be reentered when a transaction is open via
1519 * quota file writes. If we were to commit the transaction while thus
1520 * reentered, there can be a deadlock - we would be holding a quota
1521 * lock, and the commit would never complete if another thread had a
1522 * transaction open and was blocking on the quota lock - a ranking
1525 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1526 * will _not_ run commit under these circumstances because handle->h_ref
1527 * is elevated. We'll still have enough credits for the tiny quotafile
1530 static int do_journal_get_write_access(handle_t
*handle
,
1531 struct buffer_head
*bh
)
1533 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1535 return ext4_journal_get_write_access(handle
, bh
);
1538 static int ext4_write_begin(struct file
*file
, struct address_space
*mapping
,
1539 loff_t pos
, unsigned len
, unsigned flags
,
1540 struct page
**pagep
, void **fsdata
)
1542 struct inode
*inode
= mapping
->host
;
1543 int ret
, needed_blocks
;
1550 trace_ext4_write_begin(inode
, pos
, len
, flags
);
1552 * Reserve one block more for addition to orphan list in case
1553 * we allocate blocks but write fails for some reason
1555 needed_blocks
= ext4_writepage_trans_blocks(inode
) + 1;
1556 index
= pos
>> PAGE_CACHE_SHIFT
;
1557 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1561 handle
= ext4_journal_start(inode
, needed_blocks
);
1562 if (IS_ERR(handle
)) {
1563 ret
= PTR_ERR(handle
);
1567 /* We cannot recurse into the filesystem as the transaction is already
1569 flags
|= AOP_FLAG_NOFS
;
1571 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1573 ext4_journal_stop(handle
);
1579 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
1582 if (!ret
&& ext4_should_journal_data(inode
)) {
1583 ret
= walk_page_buffers(handle
, page_buffers(page
),
1584 from
, to
, NULL
, do_journal_get_write_access
);
1589 page_cache_release(page
);
1591 * block_write_begin may have instantiated a few blocks
1592 * outside i_size. Trim these off again. Don't need
1593 * i_size_read because we hold i_mutex.
1595 * Add inode to orphan list in case we crash before
1598 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1599 ext4_orphan_add(handle
, inode
);
1601 ext4_journal_stop(handle
);
1602 if (pos
+ len
> inode
->i_size
) {
1603 ext4_truncate(inode
);
1605 * If truncate failed early the inode might
1606 * still be on the orphan list; we need to
1607 * make sure the inode is removed from the
1608 * orphan list in that case.
1611 ext4_orphan_del(NULL
, inode
);
1615 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1621 /* For write_end() in data=journal mode */
1622 static int write_end_fn(handle_t
*handle
, struct buffer_head
*bh
)
1624 if (!buffer_mapped(bh
) || buffer_freed(bh
))
1626 set_buffer_uptodate(bh
);
1627 return ext4_handle_dirty_metadata(handle
, NULL
, bh
);
1630 static int ext4_generic_write_end(struct file
*file
,
1631 struct address_space
*mapping
,
1632 loff_t pos
, unsigned len
, unsigned copied
,
1633 struct page
*page
, void *fsdata
)
1635 int i_size_changed
= 0;
1636 struct inode
*inode
= mapping
->host
;
1637 handle_t
*handle
= ext4_journal_current_handle();
1639 copied
= block_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1642 * No need to use i_size_read() here, the i_size
1643 * cannot change under us because we hold i_mutex.
1645 * But it's important to update i_size while still holding page lock:
1646 * page writeout could otherwise come in and zero beyond i_size.
1648 if (pos
+ copied
> inode
->i_size
) {
1649 i_size_write(inode
, pos
+ copied
);
1653 if (pos
+ copied
> EXT4_I(inode
)->i_disksize
) {
1654 /* We need to mark inode dirty even if
1655 * new_i_size is less that inode->i_size
1656 * bu greater than i_disksize.(hint delalloc)
1658 ext4_update_i_disksize(inode
, (pos
+ copied
));
1662 page_cache_release(page
);
1665 * Don't mark the inode dirty under page lock. First, it unnecessarily
1666 * makes the holding time of page lock longer. Second, it forces lock
1667 * ordering of page lock and transaction start for journaling
1671 ext4_mark_inode_dirty(handle
, inode
);
1677 * We need to pick up the new inode size which generic_commit_write gave us
1678 * `file' can be NULL - eg, when called from page_symlink().
1680 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1681 * buffers are managed internally.
1683 static int ext4_ordered_write_end(struct file
*file
,
1684 struct address_space
*mapping
,
1685 loff_t pos
, unsigned len
, unsigned copied
,
1686 struct page
*page
, void *fsdata
)
1688 handle_t
*handle
= ext4_journal_current_handle();
1689 struct inode
*inode
= mapping
->host
;
1692 trace_ext4_ordered_write_end(inode
, pos
, len
, copied
);
1693 ret
= ext4_jbd2_file_inode(handle
, inode
);
1696 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1699 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1700 /* if we have allocated more blocks and copied
1701 * less. We will have blocks allocated outside
1702 * inode->i_size. So truncate them
1704 ext4_orphan_add(handle
, inode
);
1708 ret2
= ext4_journal_stop(handle
);
1712 if (pos
+ len
> inode
->i_size
) {
1713 ext4_truncate(inode
);
1715 * If truncate failed early the inode might still be
1716 * on the orphan list; we need to make sure the inode
1717 * is removed from the orphan list in that case.
1720 ext4_orphan_del(NULL
, inode
);
1724 return ret
? ret
: copied
;
1727 static int ext4_writeback_write_end(struct file
*file
,
1728 struct address_space
*mapping
,
1729 loff_t pos
, unsigned len
, unsigned copied
,
1730 struct page
*page
, void *fsdata
)
1732 handle_t
*handle
= ext4_journal_current_handle();
1733 struct inode
*inode
= mapping
->host
;
1736 trace_ext4_writeback_write_end(inode
, pos
, len
, copied
);
1737 ret2
= ext4_generic_write_end(file
, mapping
, pos
, len
, copied
,
1740 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1741 /* if we have allocated more blocks and copied
1742 * less. We will have blocks allocated outside
1743 * inode->i_size. So truncate them
1745 ext4_orphan_add(handle
, inode
);
1750 ret2
= ext4_journal_stop(handle
);
1754 if (pos
+ len
> inode
->i_size
) {
1755 ext4_truncate(inode
);
1757 * If truncate failed early the inode might still be
1758 * on the orphan list; we need to make sure the inode
1759 * is removed from the orphan list in that case.
1762 ext4_orphan_del(NULL
, inode
);
1765 return ret
? ret
: copied
;
1768 static int ext4_journalled_write_end(struct file
*file
,
1769 struct address_space
*mapping
,
1770 loff_t pos
, unsigned len
, unsigned copied
,
1771 struct page
*page
, void *fsdata
)
1773 handle_t
*handle
= ext4_journal_current_handle();
1774 struct inode
*inode
= mapping
->host
;
1780 trace_ext4_journalled_write_end(inode
, pos
, len
, copied
);
1781 from
= pos
& (PAGE_CACHE_SIZE
- 1);
1785 if (!PageUptodate(page
))
1787 page_zero_new_buffers(page
, from
+copied
, to
);
1790 ret
= walk_page_buffers(handle
, page_buffers(page
), from
,
1791 to
, &partial
, write_end_fn
);
1793 SetPageUptodate(page
);
1794 new_i_size
= pos
+ copied
;
1795 if (new_i_size
> inode
->i_size
)
1796 i_size_write(inode
, pos
+copied
);
1797 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
1798 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
1799 ext4_update_i_disksize(inode
, new_i_size
);
1800 ret2
= ext4_mark_inode_dirty(handle
, inode
);
1806 page_cache_release(page
);
1807 if (pos
+ len
> inode
->i_size
&& ext4_can_truncate(inode
))
1808 /* if we have allocated more blocks and copied
1809 * less. We will have blocks allocated outside
1810 * inode->i_size. So truncate them
1812 ext4_orphan_add(handle
, inode
);
1814 ret2
= ext4_journal_stop(handle
);
1817 if (pos
+ len
> inode
->i_size
) {
1818 ext4_truncate(inode
);
1820 * If truncate failed early the inode might still be
1821 * on the orphan list; we need to make sure the inode
1822 * is removed from the orphan list in that case.
1825 ext4_orphan_del(NULL
, inode
);
1828 return ret
? ret
: copied
;
1831 static int ext4_da_reserve_space(struct inode
*inode
, int nrblocks
)
1834 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1835 unsigned long md_needed
, mdblocks
, total
= 0;
1838 * recalculate the amount of metadata blocks to reserve
1839 * in order to allocate nrblocks
1840 * worse case is one extent per block
1843 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1844 total
= EXT4_I(inode
)->i_reserved_data_blocks
+ nrblocks
;
1845 mdblocks
= ext4_calc_metadata_amount(inode
, total
);
1846 BUG_ON(mdblocks
< EXT4_I(inode
)->i_reserved_meta_blocks
);
1848 md_needed
= mdblocks
- EXT4_I(inode
)->i_reserved_meta_blocks
;
1849 total
= md_needed
+ nrblocks
;
1852 * Make quota reservation here to prevent quota overflow
1853 * later. Real quota accounting is done at pages writeout
1856 if (vfs_dq_reserve_block(inode
, total
)) {
1857 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1861 if (ext4_claim_free_blocks(sbi
, total
)) {
1862 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1863 vfs_dq_release_reservation_block(inode
, total
);
1864 if (ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
1870 EXT4_I(inode
)->i_reserved_data_blocks
+= nrblocks
;
1871 EXT4_I(inode
)->i_reserved_meta_blocks
= mdblocks
;
1873 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1874 return 0; /* success */
1877 static void ext4_da_release_space(struct inode
*inode
, int to_free
)
1879 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1880 int total
, mdb
, mdb_free
, release
;
1883 return; /* Nothing to release, exit */
1885 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1887 if (!EXT4_I(inode
)->i_reserved_data_blocks
) {
1889 * if there is no reserved blocks, but we try to free some
1890 * then the counter is messed up somewhere.
1891 * but since this function is called from invalidate
1892 * page, it's harmless to return without any action
1894 printk(KERN_INFO
"ext4 delalloc try to release %d reserved "
1895 "blocks for inode %lu, but there is no reserved "
1896 "data blocks\n", to_free
, inode
->i_ino
);
1897 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1901 /* recalculate the number of metablocks still need to be reserved */
1902 total
= EXT4_I(inode
)->i_reserved_data_blocks
- to_free
;
1903 mdb
= ext4_calc_metadata_amount(inode
, total
);
1905 /* figure out how many metablocks to release */
1906 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1907 mdb_free
= EXT4_I(inode
)->i_reserved_meta_blocks
- mdb
;
1909 release
= to_free
+ mdb_free
;
1911 /* update fs dirty blocks counter for truncate case */
1912 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, release
);
1914 /* update per-inode reservations */
1915 BUG_ON(to_free
> EXT4_I(inode
)->i_reserved_data_blocks
);
1916 EXT4_I(inode
)->i_reserved_data_blocks
-= to_free
;
1918 BUG_ON(mdb
> EXT4_I(inode
)->i_reserved_meta_blocks
);
1919 EXT4_I(inode
)->i_reserved_meta_blocks
= mdb
;
1920 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1922 vfs_dq_release_reservation_block(inode
, release
);
1925 static void ext4_da_page_release_reservation(struct page
*page
,
1926 unsigned long offset
)
1929 struct buffer_head
*head
, *bh
;
1930 unsigned int curr_off
= 0;
1932 head
= page_buffers(page
);
1935 unsigned int next_off
= curr_off
+ bh
->b_size
;
1937 if ((offset
<= curr_off
) && (buffer_delay(bh
))) {
1939 clear_buffer_delay(bh
);
1941 curr_off
= next_off
;
1942 } while ((bh
= bh
->b_this_page
) != head
);
1943 ext4_da_release_space(page
->mapping
->host
, to_release
);
1947 * Delayed allocation stuff
1951 * mpage_da_submit_io - walks through extent of pages and try to write
1952 * them with writepage() call back
1954 * @mpd->inode: inode
1955 * @mpd->first_page: first page of the extent
1956 * @mpd->next_page: page after the last page of the extent
1958 * By the time mpage_da_submit_io() is called we expect all blocks
1959 * to be allocated. this may be wrong if allocation failed.
1961 * As pages are already locked by write_cache_pages(), we can't use it
1963 static int mpage_da_submit_io(struct mpage_da_data
*mpd
)
1966 struct pagevec pvec
;
1967 unsigned long index
, end
;
1968 int ret
= 0, err
, nr_pages
, i
;
1969 struct inode
*inode
= mpd
->inode
;
1970 struct address_space
*mapping
= inode
->i_mapping
;
1972 BUG_ON(mpd
->next_page
<= mpd
->first_page
);
1974 * We need to start from the first_page to the next_page - 1
1975 * to make sure we also write the mapped dirty buffer_heads.
1976 * If we look at mpd->b_blocknr we would only be looking
1977 * at the currently mapped buffer_heads.
1979 index
= mpd
->first_page
;
1980 end
= mpd
->next_page
- 1;
1982 pagevec_init(&pvec
, 0);
1983 while (index
<= end
) {
1984 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
1987 for (i
= 0; i
< nr_pages
; i
++) {
1988 struct page
*page
= pvec
.pages
[i
];
1990 index
= page
->index
;
1995 BUG_ON(!PageLocked(page
));
1996 BUG_ON(PageWriteback(page
));
1998 pages_skipped
= mpd
->wbc
->pages_skipped
;
1999 err
= mapping
->a_ops
->writepage(page
, mpd
->wbc
);
2000 if (!err
&& (pages_skipped
== mpd
->wbc
->pages_skipped
))
2002 * have successfully written the page
2003 * without skipping the same
2005 mpd
->pages_written
++;
2007 * In error case, we have to continue because
2008 * remaining pages are still locked
2009 * XXX: unlock and re-dirty them?
2014 pagevec_release(&pvec
);
2020 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
2022 * @mpd->inode - inode to walk through
2023 * @exbh->b_blocknr - first block on a disk
2024 * @exbh->b_size - amount of space in bytes
2025 * @logical - first logical block to start assignment with
2027 * the function goes through all passed space and put actual disk
2028 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
2030 static void mpage_put_bnr_to_bhs(struct mpage_da_data
*mpd
, sector_t logical
,
2031 struct buffer_head
*exbh
)
2033 struct inode
*inode
= mpd
->inode
;
2034 struct address_space
*mapping
= inode
->i_mapping
;
2035 int blocks
= exbh
->b_size
>> inode
->i_blkbits
;
2036 sector_t pblock
= exbh
->b_blocknr
, cur_logical
;
2037 struct buffer_head
*head
, *bh
;
2039 struct pagevec pvec
;
2042 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2043 end
= (logical
+ blocks
- 1) >> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2044 cur_logical
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2046 pagevec_init(&pvec
, 0);
2048 while (index
<= end
) {
2049 /* XXX: optimize tail */
2050 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2053 for (i
= 0; i
< nr_pages
; i
++) {
2054 struct page
*page
= pvec
.pages
[i
];
2056 index
= page
->index
;
2061 BUG_ON(!PageLocked(page
));
2062 BUG_ON(PageWriteback(page
));
2063 BUG_ON(!page_has_buffers(page
));
2065 bh
= page_buffers(page
);
2068 /* skip blocks out of the range */
2070 if (cur_logical
>= logical
)
2073 } while ((bh
= bh
->b_this_page
) != head
);
2076 if (cur_logical
>= logical
+ blocks
)
2079 if (buffer_delay(bh
) ||
2080 buffer_unwritten(bh
)) {
2082 BUG_ON(bh
->b_bdev
!= inode
->i_sb
->s_bdev
);
2084 if (buffer_delay(bh
)) {
2085 clear_buffer_delay(bh
);
2086 bh
->b_blocknr
= pblock
;
2089 * unwritten already should have
2090 * blocknr assigned. Verify that
2092 clear_buffer_unwritten(bh
);
2093 BUG_ON(bh
->b_blocknr
!= pblock
);
2096 } else if (buffer_mapped(bh
))
2097 BUG_ON(bh
->b_blocknr
!= pblock
);
2101 } while ((bh
= bh
->b_this_page
) != head
);
2103 pagevec_release(&pvec
);
2109 * __unmap_underlying_blocks - just a helper function to unmap
2110 * set of blocks described by @bh
2112 static inline void __unmap_underlying_blocks(struct inode
*inode
,
2113 struct buffer_head
*bh
)
2115 struct block_device
*bdev
= inode
->i_sb
->s_bdev
;
2118 blocks
= bh
->b_size
>> inode
->i_blkbits
;
2119 for (i
= 0; i
< blocks
; i
++)
2120 unmap_underlying_metadata(bdev
, bh
->b_blocknr
+ i
);
2123 static void ext4_da_block_invalidatepages(struct mpage_da_data
*mpd
,
2124 sector_t logical
, long blk_cnt
)
2128 struct pagevec pvec
;
2129 struct inode
*inode
= mpd
->inode
;
2130 struct address_space
*mapping
= inode
->i_mapping
;
2132 index
= logical
>> (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2133 end
= (logical
+ blk_cnt
- 1) >>
2134 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2135 while (index
<= end
) {
2136 nr_pages
= pagevec_lookup(&pvec
, mapping
, index
, PAGEVEC_SIZE
);
2139 for (i
= 0; i
< nr_pages
; i
++) {
2140 struct page
*page
= pvec
.pages
[i
];
2141 index
= page
->index
;
2146 BUG_ON(!PageLocked(page
));
2147 BUG_ON(PageWriteback(page
));
2148 block_invalidatepage(page
, 0);
2149 ClearPageUptodate(page
);
2156 static void ext4_print_free_blocks(struct inode
*inode
)
2158 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2159 printk(KERN_CRIT
"Total free blocks count %lld\n",
2160 ext4_count_free_blocks(inode
->i_sb
));
2161 printk(KERN_CRIT
"Free/Dirty block details\n");
2162 printk(KERN_CRIT
"free_blocks=%lld\n",
2163 (long long) percpu_counter_sum(&sbi
->s_freeblocks_counter
));
2164 printk(KERN_CRIT
"dirty_blocks=%lld\n",
2165 (long long) percpu_counter_sum(&sbi
->s_dirtyblocks_counter
));
2166 printk(KERN_CRIT
"Block reservation details\n");
2167 printk(KERN_CRIT
"i_reserved_data_blocks=%u\n",
2168 EXT4_I(inode
)->i_reserved_data_blocks
);
2169 printk(KERN_CRIT
"i_reserved_meta_blocks=%u\n",
2170 EXT4_I(inode
)->i_reserved_meta_blocks
);
2175 * mpage_da_map_blocks - go through given space
2177 * @mpd - bh describing space
2179 * The function skips space we know is already mapped to disk blocks.
2182 static int mpage_da_map_blocks(struct mpage_da_data
*mpd
)
2184 int err
, blks
, get_blocks_flags
;
2185 struct buffer_head
new;
2186 sector_t next
= mpd
->b_blocknr
;
2187 unsigned max_blocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2188 loff_t disksize
= EXT4_I(mpd
->inode
)->i_disksize
;
2189 handle_t
*handle
= NULL
;
2192 * We consider only non-mapped and non-allocated blocks
2194 if ((mpd
->b_state
& (1 << BH_Mapped
)) &&
2195 !(mpd
->b_state
& (1 << BH_Delay
)) &&
2196 !(mpd
->b_state
& (1 << BH_Unwritten
)))
2200 * If we didn't accumulate anything to write simply return
2205 handle
= ext4_journal_current_handle();
2209 * Call ext4_get_blocks() to allocate any delayed allocation
2210 * blocks, or to convert an uninitialized extent to be
2211 * initialized (in the case where we have written into
2212 * one or more preallocated blocks).
2214 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2215 * indicate that we are on the delayed allocation path. This
2216 * affects functions in many different parts of the allocation
2217 * call path. This flag exists primarily because we don't
2218 * want to change *many* call functions, so ext4_get_blocks()
2219 * will set the magic i_delalloc_reserved_flag once the
2220 * inode's allocation semaphore is taken.
2222 * If the blocks in questions were delalloc blocks, set
2223 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2224 * variables are updated after the blocks have been allocated.
2227 get_blocks_flags
= (EXT4_GET_BLOCKS_CREATE
|
2228 EXT4_GET_BLOCKS_DELALLOC_RESERVE
);
2229 if (mpd
->b_state
& (1 << BH_Delay
))
2230 get_blocks_flags
|= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE
;
2231 blks
= ext4_get_blocks(handle
, mpd
->inode
, next
, max_blocks
,
2232 &new, get_blocks_flags
);
2236 * If get block returns with error we simply
2237 * return. Later writepage will redirty the page and
2238 * writepages will find the dirty page again
2243 if (err
== -ENOSPC
&&
2244 ext4_count_free_blocks(mpd
->inode
->i_sb
)) {
2250 * get block failure will cause us to loop in
2251 * writepages, because a_ops->writepage won't be able
2252 * to make progress. The page will be redirtied by
2253 * writepage and writepages will again try to write
2256 ext4_msg(mpd
->inode
->i_sb
, KERN_CRIT
,
2257 "delayed block allocation failed for inode %lu at "
2258 "logical offset %llu with max blocks %zd with "
2259 "error %d\n", mpd
->inode
->i_ino
,
2260 (unsigned long long) next
,
2261 mpd
->b_size
>> mpd
->inode
->i_blkbits
, err
);
2262 printk(KERN_CRIT
"This should not happen!! "
2263 "Data will be lost\n");
2264 if (err
== -ENOSPC
) {
2265 ext4_print_free_blocks(mpd
->inode
);
2267 /* invalidate all the pages */
2268 ext4_da_block_invalidatepages(mpd
, next
,
2269 mpd
->b_size
>> mpd
->inode
->i_blkbits
);
2274 new.b_size
= (blks
<< mpd
->inode
->i_blkbits
);
2276 if (buffer_new(&new))
2277 __unmap_underlying_blocks(mpd
->inode
, &new);
2280 * If blocks are delayed marked, we need to
2281 * put actual blocknr and drop delayed bit
2283 if ((mpd
->b_state
& (1 << BH_Delay
)) ||
2284 (mpd
->b_state
& (1 << BH_Unwritten
)))
2285 mpage_put_bnr_to_bhs(mpd
, next
, &new);
2287 if (ext4_should_order_data(mpd
->inode
)) {
2288 err
= ext4_jbd2_file_inode(handle
, mpd
->inode
);
2294 * Update on-disk size along with block allocation.
2296 disksize
= ((loff_t
) next
+ blks
) << mpd
->inode
->i_blkbits
;
2297 if (disksize
> i_size_read(mpd
->inode
))
2298 disksize
= i_size_read(mpd
->inode
);
2299 if (disksize
> EXT4_I(mpd
->inode
)->i_disksize
) {
2300 ext4_update_i_disksize(mpd
->inode
, disksize
);
2301 return ext4_mark_inode_dirty(handle
, mpd
->inode
);
2307 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2308 (1 << BH_Delay) | (1 << BH_Unwritten))
2311 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2313 * @mpd->lbh - extent of blocks
2314 * @logical - logical number of the block in the file
2315 * @bh - bh of the block (used to access block's state)
2317 * the function is used to collect contig. blocks in same state
2319 static void mpage_add_bh_to_extent(struct mpage_da_data
*mpd
,
2320 sector_t logical
, size_t b_size
,
2321 unsigned long b_state
)
2324 int nrblocks
= mpd
->b_size
>> mpd
->inode
->i_blkbits
;
2326 /* check if thereserved journal credits might overflow */
2327 if (!(EXT4_I(mpd
->inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
2328 if (nrblocks
>= EXT4_MAX_TRANS_DATA
) {
2330 * With non-extent format we are limited by the journal
2331 * credit available. Total credit needed to insert
2332 * nrblocks contiguous blocks is dependent on the
2333 * nrblocks. So limit nrblocks.
2336 } else if ((nrblocks
+ (b_size
>> mpd
->inode
->i_blkbits
)) >
2337 EXT4_MAX_TRANS_DATA
) {
2339 * Adding the new buffer_head would make it cross the
2340 * allowed limit for which we have journal credit
2341 * reserved. So limit the new bh->b_size
2343 b_size
= (EXT4_MAX_TRANS_DATA
- nrblocks
) <<
2344 mpd
->inode
->i_blkbits
;
2345 /* we will do mpage_da_submit_io in the next loop */
2349 * First block in the extent
2351 if (mpd
->b_size
== 0) {
2352 mpd
->b_blocknr
= logical
;
2353 mpd
->b_size
= b_size
;
2354 mpd
->b_state
= b_state
& BH_FLAGS
;
2358 next
= mpd
->b_blocknr
+ nrblocks
;
2360 * Can we merge the block to our big extent?
2362 if (logical
== next
&& (b_state
& BH_FLAGS
) == mpd
->b_state
) {
2363 mpd
->b_size
+= b_size
;
2369 * We couldn't merge the block to our extent, so we
2370 * need to flush current extent and start new one
2372 if (mpage_da_map_blocks(mpd
) == 0)
2373 mpage_da_submit_io(mpd
);
2378 static int ext4_bh_delay_or_unwritten(handle_t
*handle
, struct buffer_head
*bh
)
2380 return (buffer_delay(bh
) || buffer_unwritten(bh
)) && buffer_dirty(bh
);
2384 * __mpage_da_writepage - finds extent of pages and blocks
2386 * @page: page to consider
2387 * @wbc: not used, we just follow rules
2390 * The function finds extents of pages and scan them for all blocks.
2392 static int __mpage_da_writepage(struct page
*page
,
2393 struct writeback_control
*wbc
, void *data
)
2395 struct mpage_da_data
*mpd
= data
;
2396 struct inode
*inode
= mpd
->inode
;
2397 struct buffer_head
*bh
, *head
;
2402 * Rest of the page in the page_vec
2403 * redirty then and skip then. We will
2404 * try to write them again after
2405 * starting a new transaction
2407 redirty_page_for_writepage(wbc
, page
);
2409 return MPAGE_DA_EXTENT_TAIL
;
2412 * Can we merge this page to current extent?
2414 if (mpd
->next_page
!= page
->index
) {
2416 * Nope, we can't. So, we map non-allocated blocks
2417 * and start IO on them using writepage()
2419 if (mpd
->next_page
!= mpd
->first_page
) {
2420 if (mpage_da_map_blocks(mpd
) == 0)
2421 mpage_da_submit_io(mpd
);
2423 * skip rest of the page in the page_vec
2426 redirty_page_for_writepage(wbc
, page
);
2428 return MPAGE_DA_EXTENT_TAIL
;
2432 * Start next extent of pages ...
2434 mpd
->first_page
= page
->index
;
2444 mpd
->next_page
= page
->index
+ 1;
2445 logical
= (sector_t
) page
->index
<<
2446 (PAGE_CACHE_SHIFT
- inode
->i_blkbits
);
2448 if (!page_has_buffers(page
)) {
2449 mpage_add_bh_to_extent(mpd
, logical
, PAGE_CACHE_SIZE
,
2450 (1 << BH_Dirty
) | (1 << BH_Uptodate
));
2452 return MPAGE_DA_EXTENT_TAIL
;
2455 * Page with regular buffer heads, just add all dirty ones
2457 head
= page_buffers(page
);
2460 BUG_ON(buffer_locked(bh
));
2462 * We need to try to allocate
2463 * unmapped blocks in the same page.
2464 * Otherwise we won't make progress
2465 * with the page in ext4_writepage
2467 if (ext4_bh_delay_or_unwritten(NULL
, bh
)) {
2468 mpage_add_bh_to_extent(mpd
, logical
,
2472 return MPAGE_DA_EXTENT_TAIL
;
2473 } else if (buffer_dirty(bh
) && (buffer_mapped(bh
))) {
2475 * mapped dirty buffer. We need to update
2476 * the b_state because we look at
2477 * b_state in mpage_da_map_blocks. We don't
2478 * update b_size because if we find an
2479 * unmapped buffer_head later we need to
2480 * use the b_state flag of that buffer_head.
2482 if (mpd
->b_size
== 0)
2483 mpd
->b_state
= bh
->b_state
& BH_FLAGS
;
2486 } while ((bh
= bh
->b_this_page
) != head
);
2493 * This is a special get_blocks_t callback which is used by
2494 * ext4_da_write_begin(). It will either return mapped block or
2495 * reserve space for a single block.
2497 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2498 * We also have b_blocknr = -1 and b_bdev initialized properly
2500 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2501 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2502 * initialized properly.
2504 static int ext4_da_get_block_prep(struct inode
*inode
, sector_t iblock
,
2505 struct buffer_head
*bh_result
, int create
)
2508 sector_t invalid_block
= ~((sector_t
) 0xffff);
2510 if (invalid_block
< ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
))
2513 BUG_ON(create
== 0);
2514 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2517 * first, we need to know whether the block is allocated already
2518 * preallocated blocks are unmapped but should treated
2519 * the same as allocated blocks.
2521 ret
= ext4_get_blocks(NULL
, inode
, iblock
, 1, bh_result
, 0);
2522 if ((ret
== 0) && !buffer_delay(bh_result
)) {
2523 /* the block isn't (pre)allocated yet, let's reserve space */
2525 * XXX: __block_prepare_write() unmaps passed block,
2528 ret
= ext4_da_reserve_space(inode
, 1);
2530 /* not enough space to reserve */
2533 map_bh(bh_result
, inode
->i_sb
, invalid_block
);
2534 set_buffer_new(bh_result
);
2535 set_buffer_delay(bh_result
);
2536 } else if (ret
> 0) {
2537 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2538 if (buffer_unwritten(bh_result
)) {
2539 /* A delayed write to unwritten bh should
2540 * be marked new and mapped. Mapped ensures
2541 * that we don't do get_block multiple times
2542 * when we write to the same offset and new
2543 * ensures that we do proper zero out for
2546 set_buffer_new(bh_result
);
2547 set_buffer_mapped(bh_result
);
2556 * This function is used as a standard get_block_t calback function
2557 * when there is no desire to allocate any blocks. It is used as a
2558 * callback function for block_prepare_write(), nobh_writepage(), and
2559 * block_write_full_page(). These functions should only try to map a
2560 * single block at a time.
2562 * Since this function doesn't do block allocations even if the caller
2563 * requests it by passing in create=1, it is critically important that
2564 * any caller checks to make sure that any buffer heads are returned
2565 * by this function are either all already mapped or marked for
2566 * delayed allocation before calling nobh_writepage() or
2567 * block_write_full_page(). Otherwise, b_blocknr could be left
2568 * unitialized, and the page write functions will be taken by
2571 static int noalloc_get_block_write(struct inode
*inode
, sector_t iblock
,
2572 struct buffer_head
*bh_result
, int create
)
2575 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
2577 BUG_ON(bh_result
->b_size
!= inode
->i_sb
->s_blocksize
);
2580 * we don't want to do block allocation in writepage
2581 * so call get_block_wrap with create = 0
2583 ret
= ext4_get_blocks(NULL
, inode
, iblock
, max_blocks
, bh_result
, 0);
2585 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
2591 static int bget_one(handle_t
*handle
, struct buffer_head
*bh
)
2597 static int bput_one(handle_t
*handle
, struct buffer_head
*bh
)
2603 static int __ext4_journalled_writepage(struct page
*page
,
2604 struct writeback_control
*wbc
,
2607 struct address_space
*mapping
= page
->mapping
;
2608 struct inode
*inode
= mapping
->host
;
2609 struct buffer_head
*page_bufs
;
2610 handle_t
*handle
= NULL
;
2614 page_bufs
= page_buffers(page
);
2616 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bget_one
);
2617 /* As soon as we unlock the page, it can go away, but we have
2618 * references to buffers so we are safe */
2621 handle
= ext4_journal_start(inode
, ext4_writepage_trans_blocks(inode
));
2622 if (IS_ERR(handle
)) {
2623 ret
= PTR_ERR(handle
);
2627 ret
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2628 do_journal_get_write_access
);
2630 err
= walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
,
2634 err
= ext4_journal_stop(handle
);
2638 walk_page_buffers(handle
, page_bufs
, 0, len
, NULL
, bput_one
);
2639 EXT4_I(inode
)->i_state
|= EXT4_STATE_JDATA
;
2645 * Note that we don't need to start a transaction unless we're journaling data
2646 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2647 * need to file the inode to the transaction's list in ordered mode because if
2648 * we are writing back data added by write(), the inode is already there and if
2649 * we are writing back data modified via mmap(), noone guarantees in which
2650 * transaction the data will hit the disk. In case we are journaling data, we
2651 * cannot start transaction directly because transaction start ranks above page
2652 * lock so we have to do some magic.
2654 * This function can get called via...
2655 * - ext4_da_writepages after taking page lock (have journal handle)
2656 * - journal_submit_inode_data_buffers (no journal handle)
2657 * - shrink_page_list via pdflush (no journal handle)
2658 * - grab_page_cache when doing write_begin (have journal handle)
2660 * We don't do any block allocation in this function. If we have page with
2661 * multiple blocks we need to write those buffer_heads that are mapped. This
2662 * is important for mmaped based write. So if we do with blocksize 1K
2663 * truncate(f, 1024);
2664 * a = mmap(f, 0, 4096);
2666 * truncate(f, 4096);
2667 * we have in the page first buffer_head mapped via page_mkwrite call back
2668 * but other bufer_heads would be unmapped but dirty(dirty done via the
2669 * do_wp_page). So writepage should write the first block. If we modify
2670 * the mmap area beyond 1024 we will again get a page_fault and the
2671 * page_mkwrite callback will do the block allocation and mark the
2672 * buffer_heads mapped.
2674 * We redirty the page if we have any buffer_heads that is either delay or
2675 * unwritten in the page.
2677 * We can get recursively called as show below.
2679 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2682 * But since we don't do any block allocation we should not deadlock.
2683 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2685 static int ext4_writepage(struct page
*page
,
2686 struct writeback_control
*wbc
)
2691 struct buffer_head
*page_bufs
;
2692 struct inode
*inode
= page
->mapping
->host
;
2694 trace_ext4_writepage(inode
, page
);
2695 size
= i_size_read(inode
);
2696 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
2697 len
= size
& ~PAGE_CACHE_MASK
;
2699 len
= PAGE_CACHE_SIZE
;
2701 if (page_has_buffers(page
)) {
2702 page_bufs
= page_buffers(page
);
2703 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2704 ext4_bh_delay_or_unwritten
)) {
2706 * We don't want to do block allocation
2707 * So redirty the page and return
2708 * We may reach here when we do a journal commit
2709 * via journal_submit_inode_data_buffers.
2710 * If we don't have mapping block we just ignore
2711 * them. We can also reach here via shrink_page_list
2713 redirty_page_for_writepage(wbc
, page
);
2719 * The test for page_has_buffers() is subtle:
2720 * We know the page is dirty but it lost buffers. That means
2721 * that at some moment in time after write_begin()/write_end()
2722 * has been called all buffers have been clean and thus they
2723 * must have been written at least once. So they are all
2724 * mapped and we can happily proceed with mapping them
2725 * and writing the page.
2727 * Try to initialize the buffer_heads and check whether
2728 * all are mapped and non delay. We don't want to
2729 * do block allocation here.
2731 ret
= block_prepare_write(page
, 0, len
,
2732 noalloc_get_block_write
);
2734 page_bufs
= page_buffers(page
);
2735 /* check whether all are mapped and non delay */
2736 if (walk_page_buffers(NULL
, page_bufs
, 0, len
, NULL
,
2737 ext4_bh_delay_or_unwritten
)) {
2738 redirty_page_for_writepage(wbc
, page
);
2744 * We can't do block allocation here
2745 * so just redity the page and unlock
2748 redirty_page_for_writepage(wbc
, page
);
2752 /* now mark the buffer_heads as dirty and uptodate */
2753 block_commit_write(page
, 0, len
);
2756 if (PageChecked(page
) && ext4_should_journal_data(inode
)) {
2758 * It's mmapped pagecache. Add buffers and journal it. There
2759 * doesn't seem much point in redirtying the page here.
2761 ClearPageChecked(page
);
2762 return __ext4_journalled_writepage(page
, wbc
, len
);
2765 if (test_opt(inode
->i_sb
, NOBH
) && ext4_should_writeback_data(inode
))
2766 ret
= nobh_writepage(page
, noalloc_get_block_write
, wbc
);
2768 ret
= block_write_full_page(page
, noalloc_get_block_write
,
2775 * This is called via ext4_da_writepages() to
2776 * calulate the total number of credits to reserve to fit
2777 * a single extent allocation into a single transaction,
2778 * ext4_da_writpeages() will loop calling this before
2779 * the block allocation.
2782 static int ext4_da_writepages_trans_blocks(struct inode
*inode
)
2784 int max_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
2787 * With non-extent format the journal credit needed to
2788 * insert nrblocks contiguous block is dependent on
2789 * number of contiguous block. So we will limit
2790 * number of contiguous block to a sane value
2792 if (!(inode
->i_flags
& EXT4_EXTENTS_FL
) &&
2793 (max_blocks
> EXT4_MAX_TRANS_DATA
))
2794 max_blocks
= EXT4_MAX_TRANS_DATA
;
2796 return ext4_chunk_trans_blocks(inode
, max_blocks
);
2799 static int ext4_da_writepages(struct address_space
*mapping
,
2800 struct writeback_control
*wbc
)
2803 int range_whole
= 0;
2804 handle_t
*handle
= NULL
;
2805 struct mpage_da_data mpd
;
2806 struct inode
*inode
= mapping
->host
;
2807 int no_nrwrite_index_update
;
2808 int pages_written
= 0;
2810 unsigned int max_pages
;
2811 int range_cyclic
, cycled
= 1, io_done
= 0;
2812 int needed_blocks
, ret
= 0;
2813 long desired_nr_to_write
, nr_to_writebump
= 0;
2814 loff_t range_start
= wbc
->range_start
;
2815 struct ext4_sb_info
*sbi
= EXT4_SB(mapping
->host
->i_sb
);
2817 trace_ext4_da_writepages(inode
, wbc
);
2820 * No pages to write? This is mainly a kludge to avoid starting
2821 * a transaction for special inodes like journal inode on last iput()
2822 * because that could violate lock ordering on umount
2824 if (!mapping
->nrpages
|| !mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
))
2828 * If the filesystem has aborted, it is read-only, so return
2829 * right away instead of dumping stack traces later on that
2830 * will obscure the real source of the problem. We test
2831 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2832 * the latter could be true if the filesystem is mounted
2833 * read-only, and in that case, ext4_da_writepages should
2834 * *never* be called, so if that ever happens, we would want
2837 if (unlikely(sbi
->s_mount_flags
& EXT4_MF_FS_ABORTED
))
2840 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
2843 range_cyclic
= wbc
->range_cyclic
;
2844 if (wbc
->range_cyclic
) {
2845 index
= mapping
->writeback_index
;
2848 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2849 wbc
->range_end
= LLONG_MAX
;
2850 wbc
->range_cyclic
= 0;
2852 index
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
2855 * This works around two forms of stupidity. The first is in
2856 * the writeback code, which caps the maximum number of pages
2857 * written to be 1024 pages. This is wrong on multiple
2858 * levels; different architectues have a different page size,
2859 * which changes the maximum amount of data which gets
2860 * written. Secondly, 4 megabytes is way too small. XFS
2861 * forces this value to be 16 megabytes by multiplying
2862 * nr_to_write parameter by four, and then relies on its
2863 * allocator to allocate larger extents to make them
2864 * contiguous. Unfortunately this brings us to the second
2865 * stupidity, which is that ext4's mballoc code only allocates
2866 * at most 2048 blocks. So we force contiguous writes up to
2867 * the number of dirty blocks in the inode, or
2868 * sbi->max_writeback_mb_bump whichever is smaller.
2870 max_pages
= sbi
->s_max_writeback_mb_bump
<< (20 - PAGE_CACHE_SHIFT
);
2871 if (!range_cyclic
&& range_whole
)
2872 desired_nr_to_write
= wbc
->nr_to_write
* 8;
2874 desired_nr_to_write
= ext4_num_dirty_pages(inode
, index
,
2876 if (desired_nr_to_write
> max_pages
)
2877 desired_nr_to_write
= max_pages
;
2879 if (wbc
->nr_to_write
< desired_nr_to_write
) {
2880 nr_to_writebump
= desired_nr_to_write
- wbc
->nr_to_write
;
2881 wbc
->nr_to_write
= desired_nr_to_write
;
2885 mpd
.inode
= mapping
->host
;
2888 * we don't want write_cache_pages to update
2889 * nr_to_write and writeback_index
2891 no_nrwrite_index_update
= wbc
->no_nrwrite_index_update
;
2892 wbc
->no_nrwrite_index_update
= 1;
2893 pages_skipped
= wbc
->pages_skipped
;
2896 while (!ret
&& wbc
->nr_to_write
> 0) {
2899 * we insert one extent at a time. So we need
2900 * credit needed for single extent allocation.
2901 * journalled mode is currently not supported
2904 BUG_ON(ext4_should_journal_data(inode
));
2905 needed_blocks
= ext4_da_writepages_trans_blocks(inode
);
2907 /* start a new transaction*/
2908 handle
= ext4_journal_start(inode
, needed_blocks
);
2909 if (IS_ERR(handle
)) {
2910 ret
= PTR_ERR(handle
);
2911 ext4_msg(inode
->i_sb
, KERN_CRIT
, "%s: jbd2_start: "
2912 "%ld pages, ino %lu; err %d\n", __func__
,
2913 wbc
->nr_to_write
, inode
->i_ino
, ret
);
2914 goto out_writepages
;
2918 * Now call __mpage_da_writepage to find the next
2919 * contiguous region of logical blocks that need
2920 * blocks to be allocated by ext4. We don't actually
2921 * submit the blocks for I/O here, even though
2922 * write_cache_pages thinks it will, and will set the
2923 * pages as clean for write before calling
2924 * __mpage_da_writepage().
2932 mpd
.pages_written
= 0;
2934 ret
= write_cache_pages(mapping
, wbc
, __mpage_da_writepage
,
2937 * If we have a contigous extent of pages and we
2938 * haven't done the I/O yet, map the blocks and submit
2941 if (!mpd
.io_done
&& mpd
.next_page
!= mpd
.first_page
) {
2942 if (mpage_da_map_blocks(&mpd
) == 0)
2943 mpage_da_submit_io(&mpd
);
2945 ret
= MPAGE_DA_EXTENT_TAIL
;
2947 trace_ext4_da_write_pages(inode
, &mpd
);
2948 wbc
->nr_to_write
-= mpd
.pages_written
;
2950 ext4_journal_stop(handle
);
2952 if ((mpd
.retval
== -ENOSPC
) && sbi
->s_journal
) {
2953 /* commit the transaction which would
2954 * free blocks released in the transaction
2957 jbd2_journal_force_commit_nested(sbi
->s_journal
);
2958 wbc
->pages_skipped
= pages_skipped
;
2960 } else if (ret
== MPAGE_DA_EXTENT_TAIL
) {
2962 * got one extent now try with
2965 pages_written
+= mpd
.pages_written
;
2966 wbc
->pages_skipped
= pages_skipped
;
2969 } else if (wbc
->nr_to_write
)
2971 * There is no more writeout needed
2972 * or we requested for a noblocking writeout
2973 * and we found the device congested
2977 if (!io_done
&& !cycled
) {
2980 wbc
->range_start
= index
<< PAGE_CACHE_SHIFT
;
2981 wbc
->range_end
= mapping
->writeback_index
- 1;
2984 if (pages_skipped
!= wbc
->pages_skipped
)
2985 ext4_msg(inode
->i_sb
, KERN_CRIT
,
2986 "This should not happen leaving %s "
2987 "with nr_to_write = %ld ret = %d\n",
2988 __func__
, wbc
->nr_to_write
, ret
);
2991 index
+= pages_written
;
2992 wbc
->range_cyclic
= range_cyclic
;
2993 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
2995 * set the writeback_index so that range_cyclic
2996 * mode will write it back later
2998 mapping
->writeback_index
= index
;
3001 if (!no_nrwrite_index_update
)
3002 wbc
->no_nrwrite_index_update
= 0;
3003 if (wbc
->nr_to_write
> nr_to_writebump
)
3004 wbc
->nr_to_write
-= nr_to_writebump
;
3005 wbc
->range_start
= range_start
;
3006 trace_ext4_da_writepages_result(inode
, wbc
, ret
, pages_written
);
3010 #define FALL_BACK_TO_NONDELALLOC 1
3011 static int ext4_nonda_switch(struct super_block
*sb
)
3013 s64 free_blocks
, dirty_blocks
;
3014 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3017 * switch to non delalloc mode if we are running low
3018 * on free block. The free block accounting via percpu
3019 * counters can get slightly wrong with percpu_counter_batch getting
3020 * accumulated on each CPU without updating global counters
3021 * Delalloc need an accurate free block accounting. So switch
3022 * to non delalloc when we are near to error range.
3024 free_blocks
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
3025 dirty_blocks
= percpu_counter_read_positive(&sbi
->s_dirtyblocks_counter
);
3026 if (2 * free_blocks
< 3 * dirty_blocks
||
3027 free_blocks
< (dirty_blocks
+ EXT4_FREEBLOCKS_WATERMARK
)) {
3029 * free block count is less that 150% of dirty blocks
3030 * or free blocks is less that watermark
3037 static int ext4_da_write_begin(struct file
*file
, struct address_space
*mapping
,
3038 loff_t pos
, unsigned len
, unsigned flags
,
3039 struct page
**pagep
, void **fsdata
)
3041 int ret
, retries
= 0;
3045 struct inode
*inode
= mapping
->host
;
3048 index
= pos
>> PAGE_CACHE_SHIFT
;
3049 from
= pos
& (PAGE_CACHE_SIZE
- 1);
3052 if (ext4_nonda_switch(inode
->i_sb
)) {
3053 *fsdata
= (void *)FALL_BACK_TO_NONDELALLOC
;
3054 return ext4_write_begin(file
, mapping
, pos
,
3055 len
, flags
, pagep
, fsdata
);
3057 *fsdata
= (void *)0;
3058 trace_ext4_da_write_begin(inode
, pos
, len
, flags
);
3061 * With delayed allocation, we don't log the i_disksize update
3062 * if there is delayed block allocation. But we still need
3063 * to journalling the i_disksize update if writes to the end
3064 * of file which has an already mapped buffer.
3066 handle
= ext4_journal_start(inode
, 1);
3067 if (IS_ERR(handle
)) {
3068 ret
= PTR_ERR(handle
);
3071 /* We cannot recurse into the filesystem as the transaction is already
3073 flags
|= AOP_FLAG_NOFS
;
3075 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
3077 ext4_journal_stop(handle
);
3083 ret
= block_write_begin(file
, mapping
, pos
, len
, flags
, pagep
, fsdata
,
3084 ext4_da_get_block_prep
);
3087 ext4_journal_stop(handle
);
3088 page_cache_release(page
);
3090 * block_write_begin may have instantiated a few blocks
3091 * outside i_size. Trim these off again. Don't need
3092 * i_size_read because we hold i_mutex.
3094 if (pos
+ len
> inode
->i_size
)
3095 ext4_truncate(inode
);
3098 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3105 * Check if we should update i_disksize
3106 * when write to the end of file but not require block allocation
3108 static int ext4_da_should_update_i_disksize(struct page
*page
,
3109 unsigned long offset
)
3111 struct buffer_head
*bh
;
3112 struct inode
*inode
= page
->mapping
->host
;
3116 bh
= page_buffers(page
);
3117 idx
= offset
>> inode
->i_blkbits
;
3119 for (i
= 0; i
< idx
; i
++)
3120 bh
= bh
->b_this_page
;
3122 if (!buffer_mapped(bh
) || (buffer_delay(bh
)) || buffer_unwritten(bh
))
3127 static int ext4_da_write_end(struct file
*file
,
3128 struct address_space
*mapping
,
3129 loff_t pos
, unsigned len
, unsigned copied
,
3130 struct page
*page
, void *fsdata
)
3132 struct inode
*inode
= mapping
->host
;
3134 handle_t
*handle
= ext4_journal_current_handle();
3136 unsigned long start
, end
;
3137 int write_mode
= (int)(unsigned long)fsdata
;
3139 if (write_mode
== FALL_BACK_TO_NONDELALLOC
) {
3140 if (ext4_should_order_data(inode
)) {
3141 return ext4_ordered_write_end(file
, mapping
, pos
,
3142 len
, copied
, page
, fsdata
);
3143 } else if (ext4_should_writeback_data(inode
)) {
3144 return ext4_writeback_write_end(file
, mapping
, pos
,
3145 len
, copied
, page
, fsdata
);
3151 trace_ext4_da_write_end(inode
, pos
, len
, copied
);
3152 start
= pos
& (PAGE_CACHE_SIZE
- 1);
3153 end
= start
+ copied
- 1;
3156 * generic_write_end() will run mark_inode_dirty() if i_size
3157 * changes. So let's piggyback the i_disksize mark_inode_dirty
3161 new_i_size
= pos
+ copied
;
3162 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3163 if (ext4_da_should_update_i_disksize(page
, end
)) {
3164 down_write(&EXT4_I(inode
)->i_data_sem
);
3165 if (new_i_size
> EXT4_I(inode
)->i_disksize
) {
3167 * Updating i_disksize when extending file
3168 * without needing block allocation
3170 if (ext4_should_order_data(inode
))
3171 ret
= ext4_jbd2_file_inode(handle
,
3174 EXT4_I(inode
)->i_disksize
= new_i_size
;
3176 up_write(&EXT4_I(inode
)->i_data_sem
);
3177 /* We need to mark inode dirty even if
3178 * new_i_size is less that inode->i_size
3179 * bu greater than i_disksize.(hint delalloc)
3181 ext4_mark_inode_dirty(handle
, inode
);
3184 ret2
= generic_write_end(file
, mapping
, pos
, len
, copied
,
3189 ret2
= ext4_journal_stop(handle
);
3193 return ret
? ret
: copied
;
3196 static void ext4_da_invalidatepage(struct page
*page
, unsigned long offset
)
3199 * Drop reserved blocks
3201 BUG_ON(!PageLocked(page
));
3202 if (!page_has_buffers(page
))
3205 ext4_da_page_release_reservation(page
, offset
);
3208 ext4_invalidatepage(page
, offset
);
3214 * Force all delayed allocation blocks to be allocated for a given inode.
3216 int ext4_alloc_da_blocks(struct inode
*inode
)
3218 trace_ext4_alloc_da_blocks(inode
);
3220 if (!EXT4_I(inode
)->i_reserved_data_blocks
&&
3221 !EXT4_I(inode
)->i_reserved_meta_blocks
)
3225 * We do something simple for now. The filemap_flush() will
3226 * also start triggering a write of the data blocks, which is
3227 * not strictly speaking necessary (and for users of
3228 * laptop_mode, not even desirable). However, to do otherwise
3229 * would require replicating code paths in:
3231 * ext4_da_writepages() ->
3232 * write_cache_pages() ---> (via passed in callback function)
3233 * __mpage_da_writepage() -->
3234 * mpage_add_bh_to_extent()
3235 * mpage_da_map_blocks()
3237 * The problem is that write_cache_pages(), located in
3238 * mm/page-writeback.c, marks pages clean in preparation for
3239 * doing I/O, which is not desirable if we're not planning on
3242 * We could call write_cache_pages(), and then redirty all of
3243 * the pages by calling redirty_page_for_writeback() but that
3244 * would be ugly in the extreme. So instead we would need to
3245 * replicate parts of the code in the above functions,
3246 * simplifying them becuase we wouldn't actually intend to
3247 * write out the pages, but rather only collect contiguous
3248 * logical block extents, call the multi-block allocator, and
3249 * then update the buffer heads with the block allocations.
3251 * For now, though, we'll cheat by calling filemap_flush(),
3252 * which will map the blocks, and start the I/O, but not
3253 * actually wait for the I/O to complete.
3255 return filemap_flush(inode
->i_mapping
);
3259 * bmap() is special. It gets used by applications such as lilo and by
3260 * the swapper to find the on-disk block of a specific piece of data.
3262 * Naturally, this is dangerous if the block concerned is still in the
3263 * journal. If somebody makes a swapfile on an ext4 data-journaling
3264 * filesystem and enables swap, then they may get a nasty shock when the
3265 * data getting swapped to that swapfile suddenly gets overwritten by
3266 * the original zero's written out previously to the journal and
3267 * awaiting writeback in the kernel's buffer cache.
3269 * So, if we see any bmap calls here on a modified, data-journaled file,
3270 * take extra steps to flush any blocks which might be in the cache.
3272 static sector_t
ext4_bmap(struct address_space
*mapping
, sector_t block
)
3274 struct inode
*inode
= mapping
->host
;
3278 if (mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
) &&
3279 test_opt(inode
->i_sb
, DELALLOC
)) {
3281 * With delalloc we want to sync the file
3282 * so that we can make sure we allocate
3285 filemap_write_and_wait(mapping
);
3288 if (EXT4_JOURNAL(inode
) && EXT4_I(inode
)->i_state
& EXT4_STATE_JDATA
) {
3290 * This is a REALLY heavyweight approach, but the use of
3291 * bmap on dirty files is expected to be extremely rare:
3292 * only if we run lilo or swapon on a freshly made file
3293 * do we expect this to happen.
3295 * (bmap requires CAP_SYS_RAWIO so this does not
3296 * represent an unprivileged user DOS attack --- we'd be
3297 * in trouble if mortal users could trigger this path at
3300 * NB. EXT4_STATE_JDATA is not set on files other than
3301 * regular files. If somebody wants to bmap a directory
3302 * or symlink and gets confused because the buffer
3303 * hasn't yet been flushed to disk, they deserve
3304 * everything they get.
3307 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_JDATA
;
3308 journal
= EXT4_JOURNAL(inode
);
3309 jbd2_journal_lock_updates(journal
);
3310 err
= jbd2_journal_flush(journal
);
3311 jbd2_journal_unlock_updates(journal
);
3317 return generic_block_bmap(mapping
, block
, ext4_get_block
);
3320 static int ext4_readpage(struct file
*file
, struct page
*page
)
3322 return mpage_readpage(page
, ext4_get_block
);
3326 ext4_readpages(struct file
*file
, struct address_space
*mapping
,
3327 struct list_head
*pages
, unsigned nr_pages
)
3329 return mpage_readpages(mapping
, pages
, nr_pages
, ext4_get_block
);
3332 static void ext4_invalidatepage(struct page
*page
, unsigned long offset
)
3334 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3337 * If it's a full truncate we just forget about the pending dirtying
3340 ClearPageChecked(page
);
3343 jbd2_journal_invalidatepage(journal
, page
, offset
);
3345 block_invalidatepage(page
, offset
);
3348 static int ext4_releasepage(struct page
*page
, gfp_t wait
)
3350 journal_t
*journal
= EXT4_JOURNAL(page
->mapping
->host
);
3352 WARN_ON(PageChecked(page
));
3353 if (!page_has_buffers(page
))
3356 return jbd2_journal_try_to_free_buffers(journal
, page
, wait
);
3358 return try_to_free_buffers(page
);
3362 * O_DIRECT for ext3 (or indirect map) based files
3364 * If the O_DIRECT write will extend the file then add this inode to the
3365 * orphan list. So recovery will truncate it back to the original size
3366 * if the machine crashes during the write.
3368 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3369 * crashes then stale disk data _may_ be exposed inside the file. But current
3370 * VFS code falls back into buffered path in that case so we are safe.
3372 static ssize_t
ext4_ind_direct_IO(int rw
, struct kiocb
*iocb
,
3373 const struct iovec
*iov
, loff_t offset
,
3374 unsigned long nr_segs
)
3376 struct file
*file
= iocb
->ki_filp
;
3377 struct inode
*inode
= file
->f_mapping
->host
;
3378 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3382 size_t count
= iov_length(iov
, nr_segs
);
3386 loff_t final_size
= offset
+ count
;
3388 if (final_size
> inode
->i_size
) {
3389 /* Credits for sb + inode write */
3390 handle
= ext4_journal_start(inode
, 2);
3391 if (IS_ERR(handle
)) {
3392 ret
= PTR_ERR(handle
);
3395 ret
= ext4_orphan_add(handle
, inode
);
3397 ext4_journal_stop(handle
);
3401 ei
->i_disksize
= inode
->i_size
;
3402 ext4_journal_stop(handle
);
3407 ret
= blockdev_direct_IO(rw
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
3409 ext4_get_block
, NULL
);
3410 if (ret
== -ENOSPC
&& ext4_should_retry_alloc(inode
->i_sb
, &retries
))
3416 /* Credits for sb + inode write */
3417 handle
= ext4_journal_start(inode
, 2);
3418 if (IS_ERR(handle
)) {
3419 /* This is really bad luck. We've written the data
3420 * but cannot extend i_size. Bail out and pretend
3421 * the write failed... */
3422 ret
= PTR_ERR(handle
);
3426 ext4_orphan_del(handle
, inode
);
3428 loff_t end
= offset
+ ret
;
3429 if (end
> inode
->i_size
) {
3430 ei
->i_disksize
= end
;
3431 i_size_write(inode
, end
);
3433 * We're going to return a positive `ret'
3434 * here due to non-zero-length I/O, so there's
3435 * no way of reporting error returns from
3436 * ext4_mark_inode_dirty() to userspace. So
3439 ext4_mark_inode_dirty(handle
, inode
);
3442 err
= ext4_journal_stop(handle
);
3450 static int ext4_get_block_dio_write(struct inode
*inode
, sector_t iblock
,
3451 struct buffer_head
*bh_result
, int create
)
3453 handle_t
*handle
= NULL
;
3455 unsigned max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
3458 ext4_debug("ext4_get_block_dio_write: inode %lu, create flag %d\n",
3459 inode
->i_ino
, create
);
3461 * DIO VFS code passes create = 0 flag for write to
3462 * the middle of file. It does this to avoid block
3463 * allocation for holes, to prevent expose stale data
3464 * out when there is parallel buffered read (which does
3465 * not hold the i_mutex lock) while direct IO write has
3466 * not completed. DIO request on holes finally falls back
3467 * to buffered IO for this reason.
3469 * For ext4 extent based file, since we support fallocate,
3470 * new allocated extent as uninitialized, for holes, we
3471 * could fallocate blocks for holes, thus parallel
3472 * buffered IO read will zero out the page when read on
3473 * a hole while parallel DIO write to the hole has not completed.
3475 * when we come here, we know it's a direct IO write to
3476 * to the middle of file (<i_size)
3477 * so it's safe to override the create flag from VFS.
3479 create
= EXT4_GET_BLOCKS_DIO_CREATE_EXT
;
3481 if (max_blocks
> DIO_MAX_BLOCKS
)
3482 max_blocks
= DIO_MAX_BLOCKS
;
3483 dio_credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
3484 handle
= ext4_journal_start(inode
, dio_credits
);
3485 if (IS_ERR(handle
)) {
3486 ret
= PTR_ERR(handle
);
3489 ret
= ext4_get_blocks(handle
, inode
, iblock
, max_blocks
, bh_result
,
3492 bh_result
->b_size
= (ret
<< inode
->i_blkbits
);
3495 ext4_journal_stop(handle
);
3500 static void ext4_free_io_end(ext4_io_end_t
*io
)
3506 static void dump_aio_dio_list(struct inode
* inode
)
3509 struct list_head
*cur
, *before
, *after
;
3510 ext4_io_end_t
*io
, *io0
, *io1
;
3512 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3513 ext4_debug("inode %lu aio dio list is empty\n", inode
->i_ino
);
3517 ext4_debug("Dump inode %lu aio_dio_completed_IO list \n", inode
->i_ino
);
3518 list_for_each_entry(io
, &EXT4_I(inode
)->i_aio_dio_complete_list
, list
){
3521 io0
= container_of(before
, ext4_io_end_t
, list
);
3523 io1
= container_of(after
, ext4_io_end_t
, list
);
3525 ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
3526 io
, inode
->i_ino
, io0
, io1
);
3532 * check a range of space and convert unwritten extents to written.
3534 static int ext4_end_aio_dio_nolock(ext4_io_end_t
*io
)
3536 struct inode
*inode
= io
->inode
;
3537 loff_t offset
= io
->offset
;
3538 size_t size
= io
->size
;
3541 ext4_debug("end_aio_dio_onlock: io 0x%p from inode %lu,list->next 0x%p,"
3542 "list->prev 0x%p\n",
3543 io
, inode
->i_ino
, io
->list
.next
, io
->list
.prev
);
3545 if (list_empty(&io
->list
))
3548 if (io
->flag
!= DIO_AIO_UNWRITTEN
)
3551 if (offset
+ size
<= i_size_read(inode
))
3552 ret
= ext4_convert_unwritten_extents(inode
, offset
, size
);
3555 printk(KERN_EMERG
"%s: failed to convert unwritten"
3556 "extents to written extents, error is %d"
3557 " io is still on inode %lu aio dio list\n",
3558 __func__
, ret
, inode
->i_ino
);
3562 /* clear the DIO AIO unwritten flag */
3567 * work on completed aio dio IO, to convert unwritten extents to extents
3569 static void ext4_end_aio_dio_work(struct work_struct
*work
)
3571 ext4_io_end_t
*io
= container_of(work
, ext4_io_end_t
, work
);
3572 struct inode
*inode
= io
->inode
;
3575 mutex_lock(&inode
->i_mutex
);
3576 ret
= ext4_end_aio_dio_nolock(io
);
3578 if (!list_empty(&io
->list
))
3579 list_del_init(&io
->list
);
3580 ext4_free_io_end(io
);
3582 mutex_unlock(&inode
->i_mutex
);
3585 * This function is called from ext4_sync_file().
3587 * When AIO DIO IO is completed, the work to convert unwritten
3588 * extents to written is queued on workqueue but may not get immediately
3589 * scheduled. When fsync is called, we need to ensure the
3590 * conversion is complete before fsync returns.
3591 * The inode keeps track of a list of completed AIO from DIO path
3592 * that might needs to do the conversion. This function walks through
3593 * the list and convert the related unwritten extents to written.
3595 int flush_aio_dio_completed_IO(struct inode
*inode
)
3601 if (list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
))
3604 dump_aio_dio_list(inode
);
3605 while (!list_empty(&EXT4_I(inode
)->i_aio_dio_complete_list
)){
3606 io
= list_entry(EXT4_I(inode
)->i_aio_dio_complete_list
.next
,
3607 ext4_io_end_t
, list
);
3609 * Calling ext4_end_aio_dio_nolock() to convert completed
3612 * When ext4_sync_file() is called, run_queue() may already
3613 * about to flush the work corresponding to this io structure.
3614 * It will be upset if it founds the io structure related
3615 * to the work-to-be schedule is freed.
3617 * Thus we need to keep the io structure still valid here after
3618 * convertion finished. The io structure has a flag to
3619 * avoid double converting from both fsync and background work
3622 ret
= ext4_end_aio_dio_nolock(io
);
3626 list_del_init(&io
->list
);
3628 return (ret2
< 0) ? ret2
: 0;
3631 static ext4_io_end_t
*ext4_init_io_end (struct inode
*inode
)
3633 ext4_io_end_t
*io
= NULL
;
3635 io
= kmalloc(sizeof(*io
), GFP_NOFS
);
3644 INIT_WORK(&io
->work
, ext4_end_aio_dio_work
);
3645 INIT_LIST_HEAD(&io
->list
);
3651 static void ext4_end_io_dio(struct kiocb
*iocb
, loff_t offset
,
3652 ssize_t size
, void *private)
3654 ext4_io_end_t
*io_end
= iocb
->private;
3655 struct workqueue_struct
*wq
;
3657 /* if not async direct IO or dio with 0 bytes write, just return */
3658 if (!io_end
|| !size
)
3661 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3662 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3663 iocb
->private, io_end
->inode
->i_ino
, iocb
, offset
,
3666 /* if not aio dio with unwritten extents, just free io and return */
3667 if (io_end
->flag
!= DIO_AIO_UNWRITTEN
){
3668 ext4_free_io_end(io_end
);
3669 iocb
->private = NULL
;
3673 io_end
->offset
= offset
;
3674 io_end
->size
= size
;
3675 wq
= EXT4_SB(io_end
->inode
->i_sb
)->dio_unwritten_wq
;
3677 /* queue the work to convert unwritten extents to written */
3678 queue_work(wq
, &io_end
->work
);
3680 /* Add the io_end to per-inode completed aio dio list*/
3681 list_add_tail(&io_end
->list
,
3682 &EXT4_I(io_end
->inode
)->i_aio_dio_complete_list
);
3683 iocb
->private = NULL
;
3686 * For ext4 extent files, ext4 will do direct-io write to holes,
3687 * preallocated extents, and those write extend the file, no need to
3688 * fall back to buffered IO.
3690 * For holes, we fallocate those blocks, mark them as unintialized
3691 * If those blocks were preallocated, we mark sure they are splited, but
3692 * still keep the range to write as unintialized.
3694 * The unwrritten extents will be converted to written when DIO is completed.
3695 * For async direct IO, since the IO may still pending when return, we
3696 * set up an end_io call back function, which will do the convertion
3697 * when async direct IO completed.
3699 * If the O_DIRECT write will extend the file then add this inode to the
3700 * orphan list. So recovery will truncate it back to the original size
3701 * if the machine crashes during the write.
3704 static ssize_t
ext4_ext_direct_IO(int rw
, struct kiocb
*iocb
,
3705 const struct iovec
*iov
, loff_t offset
,
3706 unsigned long nr_segs
)
3708 struct file
*file
= iocb
->ki_filp
;
3709 struct inode
*inode
= file
->f_mapping
->host
;
3711 size_t count
= iov_length(iov
, nr_segs
);
3713 loff_t final_size
= offset
+ count
;
3714 if (rw
== WRITE
&& final_size
<= inode
->i_size
) {
3716 * We could direct write to holes and fallocate.
3718 * Allocated blocks to fill the hole are marked as uninitialized
3719 * to prevent paralel buffered read to expose the stale data
3720 * before DIO complete the data IO.
3722 * As to previously fallocated extents, ext4 get_block
3723 * will just simply mark the buffer mapped but still
3724 * keep the extents uninitialized.
3726 * for non AIO case, we will convert those unwritten extents
3727 * to written after return back from blockdev_direct_IO.
3729 * for async DIO, the conversion needs to be defered when
3730 * the IO is completed. The ext4 end_io callback function
3731 * will be called to take care of the conversion work.
3732 * Here for async case, we allocate an io_end structure to
3735 iocb
->private = NULL
;
3736 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3737 if (!is_sync_kiocb(iocb
)) {
3738 iocb
->private = ext4_init_io_end(inode
);
3742 * we save the io structure for current async
3743 * direct IO, so that later ext4_get_blocks()
3744 * could flag the io structure whether there
3745 * is a unwritten extents needs to be converted
3746 * when IO is completed.
3748 EXT4_I(inode
)->cur_aio_dio
= iocb
->private;
3751 ret
= blockdev_direct_IO(rw
, iocb
, inode
,
3752 inode
->i_sb
->s_bdev
, iov
,
3754 ext4_get_block_dio_write
,
3757 EXT4_I(inode
)->cur_aio_dio
= NULL
;
3759 * The io_end structure takes a reference to the inode,
3760 * that structure needs to be destroyed and the
3761 * reference to the inode need to be dropped, when IO is
3762 * complete, even with 0 byte write, or failed.
3764 * In the successful AIO DIO case, the io_end structure will be
3765 * desctroyed and the reference to the inode will be dropped
3766 * after the end_io call back function is called.
3768 * In the case there is 0 byte write, or error case, since
3769 * VFS direct IO won't invoke the end_io call back function,
3770 * we need to free the end_io structure here.
3772 if (ret
!= -EIOCBQUEUED
&& ret
<= 0 && iocb
->private) {
3773 ext4_free_io_end(iocb
->private);
3774 iocb
->private = NULL
;
3775 } else if (ret
> 0 && (EXT4_I(inode
)->i_state
&
3776 EXT4_STATE_DIO_UNWRITTEN
)) {
3779 * for non AIO case, since the IO is already
3780 * completed, we could do the convertion right here
3782 err
= ext4_convert_unwritten_extents(inode
,
3786 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_DIO_UNWRITTEN
;
3791 /* for write the the end of file case, we fall back to old way */
3792 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3795 static ssize_t
ext4_direct_IO(int rw
, struct kiocb
*iocb
,
3796 const struct iovec
*iov
, loff_t offset
,
3797 unsigned long nr_segs
)
3799 struct file
*file
= iocb
->ki_filp
;
3800 struct inode
*inode
= file
->f_mapping
->host
;
3802 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)
3803 return ext4_ext_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3805 return ext4_ind_direct_IO(rw
, iocb
, iov
, offset
, nr_segs
);
3809 * Pages can be marked dirty completely asynchronously from ext4's journalling
3810 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3811 * much here because ->set_page_dirty is called under VFS locks. The page is
3812 * not necessarily locked.
3814 * We cannot just dirty the page and leave attached buffers clean, because the
3815 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3816 * or jbddirty because all the journalling code will explode.
3818 * So what we do is to mark the page "pending dirty" and next time writepage
3819 * is called, propagate that into the buffers appropriately.
3821 static int ext4_journalled_set_page_dirty(struct page
*page
)
3823 SetPageChecked(page
);
3824 return __set_page_dirty_nobuffers(page
);
3827 static const struct address_space_operations ext4_ordered_aops
= {
3828 .readpage
= ext4_readpage
,
3829 .readpages
= ext4_readpages
,
3830 .writepage
= ext4_writepage
,
3831 .sync_page
= block_sync_page
,
3832 .write_begin
= ext4_write_begin
,
3833 .write_end
= ext4_ordered_write_end
,
3835 .invalidatepage
= ext4_invalidatepage
,
3836 .releasepage
= ext4_releasepage
,
3837 .direct_IO
= ext4_direct_IO
,
3838 .migratepage
= buffer_migrate_page
,
3839 .is_partially_uptodate
= block_is_partially_uptodate
,
3840 .error_remove_page
= generic_error_remove_page
,
3843 static const struct address_space_operations ext4_writeback_aops
= {
3844 .readpage
= ext4_readpage
,
3845 .readpages
= ext4_readpages
,
3846 .writepage
= ext4_writepage
,
3847 .sync_page
= block_sync_page
,
3848 .write_begin
= ext4_write_begin
,
3849 .write_end
= ext4_writeback_write_end
,
3851 .invalidatepage
= ext4_invalidatepage
,
3852 .releasepage
= ext4_releasepage
,
3853 .direct_IO
= ext4_direct_IO
,
3854 .migratepage
= buffer_migrate_page
,
3855 .is_partially_uptodate
= block_is_partially_uptodate
,
3856 .error_remove_page
= generic_error_remove_page
,
3859 static const struct address_space_operations ext4_journalled_aops
= {
3860 .readpage
= ext4_readpage
,
3861 .readpages
= ext4_readpages
,
3862 .writepage
= ext4_writepage
,
3863 .sync_page
= block_sync_page
,
3864 .write_begin
= ext4_write_begin
,
3865 .write_end
= ext4_journalled_write_end
,
3866 .set_page_dirty
= ext4_journalled_set_page_dirty
,
3868 .invalidatepage
= ext4_invalidatepage
,
3869 .releasepage
= ext4_releasepage
,
3870 .is_partially_uptodate
= block_is_partially_uptodate
,
3871 .error_remove_page
= generic_error_remove_page
,
3874 static const struct address_space_operations ext4_da_aops
= {
3875 .readpage
= ext4_readpage
,
3876 .readpages
= ext4_readpages
,
3877 .writepage
= ext4_writepage
,
3878 .writepages
= ext4_da_writepages
,
3879 .sync_page
= block_sync_page
,
3880 .write_begin
= ext4_da_write_begin
,
3881 .write_end
= ext4_da_write_end
,
3883 .invalidatepage
= ext4_da_invalidatepage
,
3884 .releasepage
= ext4_releasepage
,
3885 .direct_IO
= ext4_direct_IO
,
3886 .migratepage
= buffer_migrate_page
,
3887 .is_partially_uptodate
= block_is_partially_uptodate
,
3888 .error_remove_page
= generic_error_remove_page
,
3891 void ext4_set_aops(struct inode
*inode
)
3893 if (ext4_should_order_data(inode
) &&
3894 test_opt(inode
->i_sb
, DELALLOC
))
3895 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3896 else if (ext4_should_order_data(inode
))
3897 inode
->i_mapping
->a_ops
= &ext4_ordered_aops
;
3898 else if (ext4_should_writeback_data(inode
) &&
3899 test_opt(inode
->i_sb
, DELALLOC
))
3900 inode
->i_mapping
->a_ops
= &ext4_da_aops
;
3901 else if (ext4_should_writeback_data(inode
))
3902 inode
->i_mapping
->a_ops
= &ext4_writeback_aops
;
3904 inode
->i_mapping
->a_ops
= &ext4_journalled_aops
;
3908 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3909 * up to the end of the block which corresponds to `from'.
3910 * This required during truncate. We need to physically zero the tail end
3911 * of that block so it doesn't yield old data if the file is later grown.
3913 int ext4_block_truncate_page(handle_t
*handle
,
3914 struct address_space
*mapping
, loff_t from
)
3916 ext4_fsblk_t index
= from
>> PAGE_CACHE_SHIFT
;
3917 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
3918 unsigned blocksize
, length
, pos
;
3920 struct inode
*inode
= mapping
->host
;
3921 struct buffer_head
*bh
;
3925 page
= find_or_create_page(mapping
, from
>> PAGE_CACHE_SHIFT
,
3926 mapping_gfp_mask(mapping
) & ~__GFP_FS
);
3930 blocksize
= inode
->i_sb
->s_blocksize
;
3931 length
= blocksize
- (offset
& (blocksize
- 1));
3932 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
3935 * For "nobh" option, we can only work if we don't need to
3936 * read-in the page - otherwise we create buffers to do the IO.
3938 if (!page_has_buffers(page
) && test_opt(inode
->i_sb
, NOBH
) &&
3939 ext4_should_writeback_data(inode
) && PageUptodate(page
)) {
3940 zero_user(page
, offset
, length
);
3941 set_page_dirty(page
);
3945 if (!page_has_buffers(page
))
3946 create_empty_buffers(page
, blocksize
, 0);
3948 /* Find the buffer that contains "offset" */
3949 bh
= page_buffers(page
);
3951 while (offset
>= pos
) {
3952 bh
= bh
->b_this_page
;
3958 if (buffer_freed(bh
)) {
3959 BUFFER_TRACE(bh
, "freed: skip");
3963 if (!buffer_mapped(bh
)) {
3964 BUFFER_TRACE(bh
, "unmapped");
3965 ext4_get_block(inode
, iblock
, bh
, 0);
3966 /* unmapped? It's a hole - nothing to do */
3967 if (!buffer_mapped(bh
)) {
3968 BUFFER_TRACE(bh
, "still unmapped");
3973 /* Ok, it's mapped. Make sure it's up-to-date */
3974 if (PageUptodate(page
))
3975 set_buffer_uptodate(bh
);
3977 if (!buffer_uptodate(bh
)) {
3979 ll_rw_block(READ
, 1, &bh
);
3981 /* Uhhuh. Read error. Complain and punt. */
3982 if (!buffer_uptodate(bh
))
3986 if (ext4_should_journal_data(inode
)) {
3987 BUFFER_TRACE(bh
, "get write access");
3988 err
= ext4_journal_get_write_access(handle
, bh
);
3993 zero_user(page
, offset
, length
);
3995 BUFFER_TRACE(bh
, "zeroed end of block");
3998 if (ext4_should_journal_data(inode
)) {
3999 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
4001 if (ext4_should_order_data(inode
))
4002 err
= ext4_jbd2_file_inode(handle
, inode
);
4003 mark_buffer_dirty(bh
);
4008 page_cache_release(page
);
4013 * Probably it should be a library function... search for first non-zero word
4014 * or memcmp with zero_page, whatever is better for particular architecture.
4017 static inline int all_zeroes(__le32
*p
, __le32
*q
)
4026 * ext4_find_shared - find the indirect blocks for partial truncation.
4027 * @inode: inode in question
4028 * @depth: depth of the affected branch
4029 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4030 * @chain: place to store the pointers to partial indirect blocks
4031 * @top: place to the (detached) top of branch
4033 * This is a helper function used by ext4_truncate().
4035 * When we do truncate() we may have to clean the ends of several
4036 * indirect blocks but leave the blocks themselves alive. Block is
4037 * partially truncated if some data below the new i_size is refered
4038 * from it (and it is on the path to the first completely truncated
4039 * data block, indeed). We have to free the top of that path along
4040 * with everything to the right of the path. Since no allocation
4041 * past the truncation point is possible until ext4_truncate()
4042 * finishes, we may safely do the latter, but top of branch may
4043 * require special attention - pageout below the truncation point
4044 * might try to populate it.
4046 * We atomically detach the top of branch from the tree, store the
4047 * block number of its root in *@top, pointers to buffer_heads of
4048 * partially truncated blocks - in @chain[].bh and pointers to
4049 * their last elements that should not be removed - in
4050 * @chain[].p. Return value is the pointer to last filled element
4053 * The work left to caller to do the actual freeing of subtrees:
4054 * a) free the subtree starting from *@top
4055 * b) free the subtrees whose roots are stored in
4056 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4057 * c) free the subtrees growing from the inode past the @chain[0].
4058 * (no partially truncated stuff there). */
4060 static Indirect
*ext4_find_shared(struct inode
*inode
, int depth
,
4061 ext4_lblk_t offsets
[4], Indirect chain
[4],
4064 Indirect
*partial
, *p
;
4068 /* Make k index the deepest non-null offest + 1 */
4069 for (k
= depth
; k
> 1 && !offsets
[k
-1]; k
--)
4071 partial
= ext4_get_branch(inode
, k
, offsets
, chain
, &err
);
4072 /* Writer: pointers */
4074 partial
= chain
+ k
-1;
4076 * If the branch acquired continuation since we've looked at it -
4077 * fine, it should all survive and (new) top doesn't belong to us.
4079 if (!partial
->key
&& *partial
->p
)
4082 for (p
= partial
; (p
> chain
) && all_zeroes((__le32
*) p
->bh
->b_data
, p
->p
); p
--)
4085 * OK, we've found the last block that must survive. The rest of our
4086 * branch should be detached before unlocking. However, if that rest
4087 * of branch is all ours and does not grow immediately from the inode
4088 * it's easier to cheat and just decrement partial->p.
4090 if (p
== chain
+ k
- 1 && p
> chain
) {
4094 /* Nope, don't do this in ext4. Must leave the tree intact */
4101 while (partial
> p
) {
4102 brelse(partial
->bh
);
4110 * Zero a number of block pointers in either an inode or an indirect block.
4111 * If we restart the transaction we must again get write access to the
4112 * indirect block for further modification.
4114 * We release `count' blocks on disk, but (last - first) may be greater
4115 * than `count' because there can be holes in there.
4117 static void ext4_clear_blocks(handle_t
*handle
, struct inode
*inode
,
4118 struct buffer_head
*bh
,
4119 ext4_fsblk_t block_to_free
,
4120 unsigned long count
, __le32
*first
,
4124 if (try_to_extend_transaction(handle
, inode
)) {
4126 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
4127 ext4_handle_dirty_metadata(handle
, inode
, bh
);
4129 ext4_mark_inode_dirty(handle
, inode
);
4130 ext4_truncate_restart_trans(handle
, inode
,
4131 blocks_for_truncate(inode
));
4133 BUFFER_TRACE(bh
, "retaking write access");
4134 ext4_journal_get_write_access(handle
, bh
);
4139 * Any buffers which are on the journal will be in memory. We
4140 * find them on the hash table so jbd2_journal_revoke() will
4141 * run jbd2_journal_forget() on them. We've already detached
4142 * each block from the file, so bforget() in
4143 * jbd2_journal_forget() should be safe.
4145 * AKPM: turn on bforget in jbd2_journal_forget()!!!
4147 for (p
= first
; p
< last
; p
++) {
4148 u32 nr
= le32_to_cpu(*p
);
4150 struct buffer_head
*tbh
;
4153 tbh
= sb_find_get_block(inode
->i_sb
, nr
);
4154 ext4_forget(handle
, 0, inode
, tbh
, nr
);
4158 ext4_free_blocks(handle
, inode
, block_to_free
, count
, 0);
4162 * ext4_free_data - free a list of data blocks
4163 * @handle: handle for this transaction
4164 * @inode: inode we are dealing with
4165 * @this_bh: indirect buffer_head which contains *@first and *@last
4166 * @first: array of block numbers
4167 * @last: points immediately past the end of array
4169 * We are freeing all blocks refered from that array (numbers are stored as
4170 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4172 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4173 * blocks are contiguous then releasing them at one time will only affect one
4174 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4175 * actually use a lot of journal space.
4177 * @this_bh will be %NULL if @first and @last point into the inode's direct
4180 static void ext4_free_data(handle_t
*handle
, struct inode
*inode
,
4181 struct buffer_head
*this_bh
,
4182 __le32
*first
, __le32
*last
)
4184 ext4_fsblk_t block_to_free
= 0; /* Starting block # of a run */
4185 unsigned long count
= 0; /* Number of blocks in the run */
4186 __le32
*block_to_free_p
= NULL
; /* Pointer into inode/ind
4189 ext4_fsblk_t nr
; /* Current block # */
4190 __le32
*p
; /* Pointer into inode/ind
4191 for current block */
4194 if (this_bh
) { /* For indirect block */
4195 BUFFER_TRACE(this_bh
, "get_write_access");
4196 err
= ext4_journal_get_write_access(handle
, this_bh
);
4197 /* Important: if we can't update the indirect pointers
4198 * to the blocks, we can't free them. */
4203 for (p
= first
; p
< last
; p
++) {
4204 nr
= le32_to_cpu(*p
);
4206 /* accumulate blocks to free if they're contiguous */
4209 block_to_free_p
= p
;
4211 } else if (nr
== block_to_free
+ count
) {
4214 ext4_clear_blocks(handle
, inode
, this_bh
,
4216 count
, block_to_free_p
, p
);
4218 block_to_free_p
= p
;
4225 ext4_clear_blocks(handle
, inode
, this_bh
, block_to_free
,
4226 count
, block_to_free_p
, p
);
4229 BUFFER_TRACE(this_bh
, "call ext4_handle_dirty_metadata");
4232 * The buffer head should have an attached journal head at this
4233 * point. However, if the data is corrupted and an indirect
4234 * block pointed to itself, it would have been detached when
4235 * the block was cleared. Check for this instead of OOPSing.
4237 if ((EXT4_JOURNAL(inode
) == NULL
) || bh2jh(this_bh
))
4238 ext4_handle_dirty_metadata(handle
, inode
, this_bh
);
4240 ext4_error(inode
->i_sb
, __func__
,
4241 "circular indirect block detected, "
4242 "inode=%lu, block=%llu",
4244 (unsigned long long) this_bh
->b_blocknr
);
4249 * ext4_free_branches - free an array of branches
4250 * @handle: JBD handle for this transaction
4251 * @inode: inode we are dealing with
4252 * @parent_bh: the buffer_head which contains *@first and *@last
4253 * @first: array of block numbers
4254 * @last: pointer immediately past the end of array
4255 * @depth: depth of the branches to free
4257 * We are freeing all blocks refered from these branches (numbers are
4258 * stored as little-endian 32-bit) and updating @inode->i_blocks
4261 static void ext4_free_branches(handle_t
*handle
, struct inode
*inode
,
4262 struct buffer_head
*parent_bh
,
4263 __le32
*first
, __le32
*last
, int depth
)
4268 if (ext4_handle_is_aborted(handle
))
4272 struct buffer_head
*bh
;
4273 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4275 while (--p
>= first
) {
4276 nr
= le32_to_cpu(*p
);
4278 continue; /* A hole */
4280 /* Go read the buffer for the next level down */
4281 bh
= sb_bread(inode
->i_sb
, nr
);
4284 * A read failure? Report error and clear slot
4288 ext4_error(inode
->i_sb
, "ext4_free_branches",
4289 "Read failure, inode=%lu, block=%llu",
4294 /* This zaps the entire block. Bottom up. */
4295 BUFFER_TRACE(bh
, "free child branches");
4296 ext4_free_branches(handle
, inode
, bh
,
4297 (__le32
*) bh
->b_data
,
4298 (__le32
*) bh
->b_data
+ addr_per_block
,
4302 * We've probably journalled the indirect block several
4303 * times during the truncate. But it's no longer
4304 * needed and we now drop it from the transaction via
4305 * jbd2_journal_revoke().
4307 * That's easy if it's exclusively part of this
4308 * transaction. But if it's part of the committing
4309 * transaction then jbd2_journal_forget() will simply
4310 * brelse() it. That means that if the underlying
4311 * block is reallocated in ext4_get_block(),
4312 * unmap_underlying_metadata() will find this block
4313 * and will try to get rid of it. damn, damn.
4315 * If this block has already been committed to the
4316 * journal, a revoke record will be written. And
4317 * revoke records must be emitted *before* clearing
4318 * this block's bit in the bitmaps.
4320 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
4323 * Everything below this this pointer has been
4324 * released. Now let this top-of-subtree go.
4326 * We want the freeing of this indirect block to be
4327 * atomic in the journal with the updating of the
4328 * bitmap block which owns it. So make some room in
4331 * We zero the parent pointer *after* freeing its
4332 * pointee in the bitmaps, so if extend_transaction()
4333 * for some reason fails to put the bitmap changes and
4334 * the release into the same transaction, recovery
4335 * will merely complain about releasing a free block,
4336 * rather than leaking blocks.
4338 if (ext4_handle_is_aborted(handle
))
4340 if (try_to_extend_transaction(handle
, inode
)) {
4341 ext4_mark_inode_dirty(handle
, inode
);
4342 ext4_truncate_restart_trans(handle
, inode
,
4343 blocks_for_truncate(inode
));
4346 ext4_free_blocks(handle
, inode
, nr
, 1, 1);
4350 * The block which we have just freed is
4351 * pointed to by an indirect block: journal it
4353 BUFFER_TRACE(parent_bh
, "get_write_access");
4354 if (!ext4_journal_get_write_access(handle
,
4357 BUFFER_TRACE(parent_bh
,
4358 "call ext4_handle_dirty_metadata");
4359 ext4_handle_dirty_metadata(handle
,
4366 /* We have reached the bottom of the tree. */
4367 BUFFER_TRACE(parent_bh
, "free data blocks");
4368 ext4_free_data(handle
, inode
, parent_bh
, first
, last
);
4372 int ext4_can_truncate(struct inode
*inode
)
4374 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
4376 if (S_ISREG(inode
->i_mode
))
4378 if (S_ISDIR(inode
->i_mode
))
4380 if (S_ISLNK(inode
->i_mode
))
4381 return !ext4_inode_is_fast_symlink(inode
);
4388 * We block out ext4_get_block() block instantiations across the entire
4389 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4390 * simultaneously on behalf of the same inode.
4392 * As we work through the truncate and commmit bits of it to the journal there
4393 * is one core, guiding principle: the file's tree must always be consistent on
4394 * disk. We must be able to restart the truncate after a crash.
4396 * The file's tree may be transiently inconsistent in memory (although it
4397 * probably isn't), but whenever we close off and commit a journal transaction,
4398 * the contents of (the filesystem + the journal) must be consistent and
4399 * restartable. It's pretty simple, really: bottom up, right to left (although
4400 * left-to-right works OK too).
4402 * Note that at recovery time, journal replay occurs *before* the restart of
4403 * truncate against the orphan inode list.
4405 * The committed inode has the new, desired i_size (which is the same as
4406 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4407 * that this inode's truncate did not complete and it will again call
4408 * ext4_truncate() to have another go. So there will be instantiated blocks
4409 * to the right of the truncation point in a crashed ext4 filesystem. But
4410 * that's fine - as long as they are linked from the inode, the post-crash
4411 * ext4_truncate() run will find them and release them.
4413 void ext4_truncate(struct inode
*inode
)
4416 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4417 __le32
*i_data
= ei
->i_data
;
4418 int addr_per_block
= EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
4419 struct address_space
*mapping
= inode
->i_mapping
;
4420 ext4_lblk_t offsets
[4];
4425 ext4_lblk_t last_block
;
4426 unsigned blocksize
= inode
->i_sb
->s_blocksize
;
4428 if (!ext4_can_truncate(inode
))
4431 if (inode
->i_size
== 0 && !test_opt(inode
->i_sb
, NO_AUTO_DA_ALLOC
))
4432 ei
->i_state
|= EXT4_STATE_DA_ALLOC_CLOSE
;
4434 if (EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
) {
4435 ext4_ext_truncate(inode
);
4439 handle
= start_transaction(inode
);
4441 return; /* AKPM: return what? */
4443 last_block
= (inode
->i_size
+ blocksize
-1)
4444 >> EXT4_BLOCK_SIZE_BITS(inode
->i_sb
);
4446 if (inode
->i_size
& (blocksize
- 1))
4447 if (ext4_block_truncate_page(handle
, mapping
, inode
->i_size
))
4450 n
= ext4_block_to_path(inode
, last_block
, offsets
, NULL
);
4452 goto out_stop
; /* error */
4455 * OK. This truncate is going to happen. We add the inode to the
4456 * orphan list, so that if this truncate spans multiple transactions,
4457 * and we crash, we will resume the truncate when the filesystem
4458 * recovers. It also marks the inode dirty, to catch the new size.
4460 * Implication: the file must always be in a sane, consistent
4461 * truncatable state while each transaction commits.
4463 if (ext4_orphan_add(handle
, inode
))
4467 * From here we block out all ext4_get_block() callers who want to
4468 * modify the block allocation tree.
4470 down_write(&ei
->i_data_sem
);
4472 ext4_discard_preallocations(inode
);
4475 * The orphan list entry will now protect us from any crash which
4476 * occurs before the truncate completes, so it is now safe to propagate
4477 * the new, shorter inode size (held for now in i_size) into the
4478 * on-disk inode. We do this via i_disksize, which is the value which
4479 * ext4 *really* writes onto the disk inode.
4481 ei
->i_disksize
= inode
->i_size
;
4483 if (n
== 1) { /* direct blocks */
4484 ext4_free_data(handle
, inode
, NULL
, i_data
+offsets
[0],
4485 i_data
+ EXT4_NDIR_BLOCKS
);
4489 partial
= ext4_find_shared(inode
, n
, offsets
, chain
, &nr
);
4490 /* Kill the top of shared branch (not detached) */
4492 if (partial
== chain
) {
4493 /* Shared branch grows from the inode */
4494 ext4_free_branches(handle
, inode
, NULL
,
4495 &nr
, &nr
+1, (chain
+n
-1) - partial
);
4498 * We mark the inode dirty prior to restart,
4499 * and prior to stop. No need for it here.
4502 /* Shared branch grows from an indirect block */
4503 BUFFER_TRACE(partial
->bh
, "get_write_access");
4504 ext4_free_branches(handle
, inode
, partial
->bh
,
4506 partial
->p
+1, (chain
+n
-1) - partial
);
4509 /* Clear the ends of indirect blocks on the shared branch */
4510 while (partial
> chain
) {
4511 ext4_free_branches(handle
, inode
, partial
->bh
, partial
->p
+ 1,
4512 (__le32
*)partial
->bh
->b_data
+addr_per_block
,
4513 (chain
+n
-1) - partial
);
4514 BUFFER_TRACE(partial
->bh
, "call brelse");
4515 brelse(partial
->bh
);
4519 /* Kill the remaining (whole) subtrees */
4520 switch (offsets
[0]) {
4522 nr
= i_data
[EXT4_IND_BLOCK
];
4524 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 1);
4525 i_data
[EXT4_IND_BLOCK
] = 0;
4527 case EXT4_IND_BLOCK
:
4528 nr
= i_data
[EXT4_DIND_BLOCK
];
4530 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 2);
4531 i_data
[EXT4_DIND_BLOCK
] = 0;
4533 case EXT4_DIND_BLOCK
:
4534 nr
= i_data
[EXT4_TIND_BLOCK
];
4536 ext4_free_branches(handle
, inode
, NULL
, &nr
, &nr
+1, 3);
4537 i_data
[EXT4_TIND_BLOCK
] = 0;
4539 case EXT4_TIND_BLOCK
:
4543 up_write(&ei
->i_data_sem
);
4544 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4545 ext4_mark_inode_dirty(handle
, inode
);
4548 * In a multi-transaction truncate, we only make the final transaction
4552 ext4_handle_sync(handle
);
4555 * If this was a simple ftruncate(), and the file will remain alive
4556 * then we need to clear up the orphan record which we created above.
4557 * However, if this was a real unlink then we were called by
4558 * ext4_delete_inode(), and we allow that function to clean up the
4559 * orphan info for us.
4562 ext4_orphan_del(handle
, inode
);
4564 ext4_journal_stop(handle
);
4568 * ext4_get_inode_loc returns with an extra refcount against the inode's
4569 * underlying buffer_head on success. If 'in_mem' is true, we have all
4570 * data in memory that is needed to recreate the on-disk version of this
4573 static int __ext4_get_inode_loc(struct inode
*inode
,
4574 struct ext4_iloc
*iloc
, int in_mem
)
4576 struct ext4_group_desc
*gdp
;
4577 struct buffer_head
*bh
;
4578 struct super_block
*sb
= inode
->i_sb
;
4580 int inodes_per_block
, inode_offset
;
4583 if (!ext4_valid_inum(sb
, inode
->i_ino
))
4586 iloc
->block_group
= (inode
->i_ino
- 1) / EXT4_INODES_PER_GROUP(sb
);
4587 gdp
= ext4_get_group_desc(sb
, iloc
->block_group
, NULL
);
4592 * Figure out the offset within the block group inode table
4594 inodes_per_block
= (EXT4_BLOCK_SIZE(sb
) / EXT4_INODE_SIZE(sb
));
4595 inode_offset
= ((inode
->i_ino
- 1) %
4596 EXT4_INODES_PER_GROUP(sb
));
4597 block
= ext4_inode_table(sb
, gdp
) + (inode_offset
/ inodes_per_block
);
4598 iloc
->offset
= (inode_offset
% inodes_per_block
) * EXT4_INODE_SIZE(sb
);
4600 bh
= sb_getblk(sb
, block
);
4602 ext4_error(sb
, "ext4_get_inode_loc", "unable to read "
4603 "inode block - inode=%lu, block=%llu",
4604 inode
->i_ino
, block
);
4607 if (!buffer_uptodate(bh
)) {
4611 * If the buffer has the write error flag, we have failed
4612 * to write out another inode in the same block. In this
4613 * case, we don't have to read the block because we may
4614 * read the old inode data successfully.
4616 if (buffer_write_io_error(bh
) && !buffer_uptodate(bh
))
4617 set_buffer_uptodate(bh
);
4619 if (buffer_uptodate(bh
)) {
4620 /* someone brought it uptodate while we waited */
4626 * If we have all information of the inode in memory and this
4627 * is the only valid inode in the block, we need not read the
4631 struct buffer_head
*bitmap_bh
;
4634 start
= inode_offset
& ~(inodes_per_block
- 1);
4636 /* Is the inode bitmap in cache? */
4637 bitmap_bh
= sb_getblk(sb
, ext4_inode_bitmap(sb
, gdp
));
4642 * If the inode bitmap isn't in cache then the
4643 * optimisation may end up performing two reads instead
4644 * of one, so skip it.
4646 if (!buffer_uptodate(bitmap_bh
)) {
4650 for (i
= start
; i
< start
+ inodes_per_block
; i
++) {
4651 if (i
== inode_offset
)
4653 if (ext4_test_bit(i
, bitmap_bh
->b_data
))
4657 if (i
== start
+ inodes_per_block
) {
4658 /* all other inodes are free, so skip I/O */
4659 memset(bh
->b_data
, 0, bh
->b_size
);
4660 set_buffer_uptodate(bh
);
4668 * If we need to do any I/O, try to pre-readahead extra
4669 * blocks from the inode table.
4671 if (EXT4_SB(sb
)->s_inode_readahead_blks
) {
4672 ext4_fsblk_t b
, end
, table
;
4675 table
= ext4_inode_table(sb
, gdp
);
4676 /* s_inode_readahead_blks is always a power of 2 */
4677 b
= block
& ~(EXT4_SB(sb
)->s_inode_readahead_blks
-1);
4680 end
= b
+ EXT4_SB(sb
)->s_inode_readahead_blks
;
4681 num
= EXT4_INODES_PER_GROUP(sb
);
4682 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4683 EXT4_FEATURE_RO_COMPAT_GDT_CSUM
))
4684 num
-= ext4_itable_unused_count(sb
, gdp
);
4685 table
+= num
/ inodes_per_block
;
4689 sb_breadahead(sb
, b
++);
4693 * There are other valid inodes in the buffer, this inode
4694 * has in-inode xattrs, or we don't have this inode in memory.
4695 * Read the block from disk.
4698 bh
->b_end_io
= end_buffer_read_sync
;
4699 submit_bh(READ_META
, bh
);
4701 if (!buffer_uptodate(bh
)) {
4702 ext4_error(sb
, __func__
,
4703 "unable to read inode block - inode=%lu, "
4704 "block=%llu", inode
->i_ino
, block
);
4714 int ext4_get_inode_loc(struct inode
*inode
, struct ext4_iloc
*iloc
)
4716 /* We have all inode data except xattrs in memory here. */
4717 return __ext4_get_inode_loc(inode
, iloc
,
4718 !(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
));
4721 void ext4_set_inode_flags(struct inode
*inode
)
4723 unsigned int flags
= EXT4_I(inode
)->i_flags
;
4725 inode
->i_flags
&= ~(S_SYNC
|S_APPEND
|S_IMMUTABLE
|S_NOATIME
|S_DIRSYNC
);
4726 if (flags
& EXT4_SYNC_FL
)
4727 inode
->i_flags
|= S_SYNC
;
4728 if (flags
& EXT4_APPEND_FL
)
4729 inode
->i_flags
|= S_APPEND
;
4730 if (flags
& EXT4_IMMUTABLE_FL
)
4731 inode
->i_flags
|= S_IMMUTABLE
;
4732 if (flags
& EXT4_NOATIME_FL
)
4733 inode
->i_flags
|= S_NOATIME
;
4734 if (flags
& EXT4_DIRSYNC_FL
)
4735 inode
->i_flags
|= S_DIRSYNC
;
4738 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4739 void ext4_get_inode_flags(struct ext4_inode_info
*ei
)
4741 unsigned int flags
= ei
->vfs_inode
.i_flags
;
4743 ei
->i_flags
&= ~(EXT4_SYNC_FL
|EXT4_APPEND_FL
|
4744 EXT4_IMMUTABLE_FL
|EXT4_NOATIME_FL
|EXT4_DIRSYNC_FL
);
4746 ei
->i_flags
|= EXT4_SYNC_FL
;
4747 if (flags
& S_APPEND
)
4748 ei
->i_flags
|= EXT4_APPEND_FL
;
4749 if (flags
& S_IMMUTABLE
)
4750 ei
->i_flags
|= EXT4_IMMUTABLE_FL
;
4751 if (flags
& S_NOATIME
)
4752 ei
->i_flags
|= EXT4_NOATIME_FL
;
4753 if (flags
& S_DIRSYNC
)
4754 ei
->i_flags
|= EXT4_DIRSYNC_FL
;
4757 static blkcnt_t
ext4_inode_blocks(struct ext4_inode
*raw_inode
,
4758 struct ext4_inode_info
*ei
)
4761 struct inode
*inode
= &(ei
->vfs_inode
);
4762 struct super_block
*sb
= inode
->i_sb
;
4764 if (EXT4_HAS_RO_COMPAT_FEATURE(sb
,
4765 EXT4_FEATURE_RO_COMPAT_HUGE_FILE
)) {
4766 /* we are using combined 48 bit field */
4767 i_blocks
= ((u64
)le16_to_cpu(raw_inode
->i_blocks_high
)) << 32 |
4768 le32_to_cpu(raw_inode
->i_blocks_lo
);
4769 if (ei
->i_flags
& EXT4_HUGE_FILE_FL
) {
4770 /* i_blocks represent file system block size */
4771 return i_blocks
<< (inode
->i_blkbits
- 9);
4776 return le32_to_cpu(raw_inode
->i_blocks_lo
);
4780 struct inode
*ext4_iget(struct super_block
*sb
, unsigned long ino
)
4782 struct ext4_iloc iloc
;
4783 struct ext4_inode
*raw_inode
;
4784 struct ext4_inode_info
*ei
;
4785 struct inode
*inode
;
4789 inode
= iget_locked(sb
, ino
);
4791 return ERR_PTR(-ENOMEM
);
4792 if (!(inode
->i_state
& I_NEW
))
4798 ret
= __ext4_get_inode_loc(inode
, &iloc
, 0);
4801 raw_inode
= ext4_raw_inode(&iloc
);
4802 inode
->i_mode
= le16_to_cpu(raw_inode
->i_mode
);
4803 inode
->i_uid
= (uid_t
)le16_to_cpu(raw_inode
->i_uid_low
);
4804 inode
->i_gid
= (gid_t
)le16_to_cpu(raw_inode
->i_gid_low
);
4805 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
4806 inode
->i_uid
|= le16_to_cpu(raw_inode
->i_uid_high
) << 16;
4807 inode
->i_gid
|= le16_to_cpu(raw_inode
->i_gid_high
) << 16;
4809 inode
->i_nlink
= le16_to_cpu(raw_inode
->i_links_count
);
4812 ei
->i_dir_start_lookup
= 0;
4813 ei
->i_dtime
= le32_to_cpu(raw_inode
->i_dtime
);
4814 /* We now have enough fields to check if the inode was active or not.
4815 * This is needed because nfsd might try to access dead inodes
4816 * the test is that same one that e2fsck uses
4817 * NeilBrown 1999oct15
4819 if (inode
->i_nlink
== 0) {
4820 if (inode
->i_mode
== 0 ||
4821 !(EXT4_SB(inode
->i_sb
)->s_mount_state
& EXT4_ORPHAN_FS
)) {
4822 /* this inode is deleted */
4826 /* The only unlinked inodes we let through here have
4827 * valid i_mode and are being read by the orphan
4828 * recovery code: that's fine, we're about to complete
4829 * the process of deleting those. */
4831 ei
->i_flags
= le32_to_cpu(raw_inode
->i_flags
);
4832 inode
->i_blocks
= ext4_inode_blocks(raw_inode
, ei
);
4833 ei
->i_file_acl
= le32_to_cpu(raw_inode
->i_file_acl_lo
);
4834 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_64BIT
))
4836 ((__u64
)le16_to_cpu(raw_inode
->i_file_acl_high
)) << 32;
4837 inode
->i_size
= ext4_isize(raw_inode
);
4838 ei
->i_disksize
= inode
->i_size
;
4839 inode
->i_generation
= le32_to_cpu(raw_inode
->i_generation
);
4840 ei
->i_block_group
= iloc
.block_group
;
4841 ei
->i_last_alloc_group
= ~0;
4843 * NOTE! The in-memory inode i_data array is in little-endian order
4844 * even on big-endian machines: we do NOT byteswap the block numbers!
4846 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
4847 ei
->i_data
[block
] = raw_inode
->i_block
[block
];
4848 INIT_LIST_HEAD(&ei
->i_orphan
);
4850 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4851 ei
->i_extra_isize
= le16_to_cpu(raw_inode
->i_extra_isize
);
4852 if (EXT4_GOOD_OLD_INODE_SIZE
+ ei
->i_extra_isize
>
4853 EXT4_INODE_SIZE(inode
->i_sb
)) {
4857 if (ei
->i_extra_isize
== 0) {
4858 /* The extra space is currently unused. Use it. */
4859 ei
->i_extra_isize
= sizeof(struct ext4_inode
) -
4860 EXT4_GOOD_OLD_INODE_SIZE
;
4862 __le32
*magic
= (void *)raw_inode
+
4863 EXT4_GOOD_OLD_INODE_SIZE
+
4865 if (*magic
== cpu_to_le32(EXT4_XATTR_MAGIC
))
4866 ei
->i_state
|= EXT4_STATE_XATTR
;
4869 ei
->i_extra_isize
= 0;
4871 EXT4_INODE_GET_XTIME(i_ctime
, inode
, raw_inode
);
4872 EXT4_INODE_GET_XTIME(i_mtime
, inode
, raw_inode
);
4873 EXT4_INODE_GET_XTIME(i_atime
, inode
, raw_inode
);
4874 EXT4_EINODE_GET_XTIME(i_crtime
, ei
, raw_inode
);
4876 inode
->i_version
= le32_to_cpu(raw_inode
->i_disk_version
);
4877 if (EXT4_INODE_SIZE(inode
->i_sb
) > EXT4_GOOD_OLD_INODE_SIZE
) {
4878 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
4880 (__u64
)(le32_to_cpu(raw_inode
->i_version_hi
)) << 32;
4884 if (ei
->i_file_acl
&&
4886 (le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
) +
4887 EXT4_SB(sb
)->s_gdb_count
)) ||
4888 (ei
->i_file_acl
>= ext4_blocks_count(EXT4_SB(sb
)->s_es
)))) {
4889 ext4_error(sb
, __func__
,
4890 "bad extended attribute block %llu in inode #%lu",
4891 ei
->i_file_acl
, inode
->i_ino
);
4894 } else if (ei
->i_flags
& EXT4_EXTENTS_FL
) {
4895 if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4896 (S_ISLNK(inode
->i_mode
) &&
4897 !ext4_inode_is_fast_symlink(inode
)))
4898 /* Validate extent which is part of inode */
4899 ret
= ext4_ext_check_inode(inode
);
4900 } else if (S_ISREG(inode
->i_mode
) || S_ISDIR(inode
->i_mode
) ||
4901 (S_ISLNK(inode
->i_mode
) &&
4902 !ext4_inode_is_fast_symlink(inode
))) {
4903 /* Validate block references which are part of inode */
4904 ret
= ext4_check_inode_blockref(inode
);
4909 if (S_ISREG(inode
->i_mode
)) {
4910 inode
->i_op
= &ext4_file_inode_operations
;
4911 inode
->i_fop
= &ext4_file_operations
;
4912 ext4_set_aops(inode
);
4913 } else if (S_ISDIR(inode
->i_mode
)) {
4914 inode
->i_op
= &ext4_dir_inode_operations
;
4915 inode
->i_fop
= &ext4_dir_operations
;
4916 } else if (S_ISLNK(inode
->i_mode
)) {
4917 if (ext4_inode_is_fast_symlink(inode
)) {
4918 inode
->i_op
= &ext4_fast_symlink_inode_operations
;
4919 nd_terminate_link(ei
->i_data
, inode
->i_size
,
4920 sizeof(ei
->i_data
) - 1);
4922 inode
->i_op
= &ext4_symlink_inode_operations
;
4923 ext4_set_aops(inode
);
4925 } else if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
) ||
4926 S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
4927 inode
->i_op
= &ext4_special_inode_operations
;
4928 if (raw_inode
->i_block
[0])
4929 init_special_inode(inode
, inode
->i_mode
,
4930 old_decode_dev(le32_to_cpu(raw_inode
->i_block
[0])));
4932 init_special_inode(inode
, inode
->i_mode
,
4933 new_decode_dev(le32_to_cpu(raw_inode
->i_block
[1])));
4936 ext4_error(inode
->i_sb
, __func__
,
4937 "bogus i_mode (%o) for inode=%lu",
4938 inode
->i_mode
, inode
->i_ino
);
4942 ext4_set_inode_flags(inode
);
4943 unlock_new_inode(inode
);
4949 return ERR_PTR(ret
);
4952 static int ext4_inode_blocks_set(handle_t
*handle
,
4953 struct ext4_inode
*raw_inode
,
4954 struct ext4_inode_info
*ei
)
4956 struct inode
*inode
= &(ei
->vfs_inode
);
4957 u64 i_blocks
= inode
->i_blocks
;
4958 struct super_block
*sb
= inode
->i_sb
;
4960 if (i_blocks
<= ~0U) {
4962 * i_blocks can be represnted in a 32 bit variable
4963 * as multiple of 512 bytes
4965 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4966 raw_inode
->i_blocks_high
= 0;
4967 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4970 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
, EXT4_FEATURE_RO_COMPAT_HUGE_FILE
))
4973 if (i_blocks
<= 0xffffffffffffULL
) {
4975 * i_blocks can be represented in a 48 bit variable
4976 * as multiple of 512 bytes
4978 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4979 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4980 ei
->i_flags
&= ~EXT4_HUGE_FILE_FL
;
4982 ei
->i_flags
|= EXT4_HUGE_FILE_FL
;
4983 /* i_block is stored in file system block size */
4984 i_blocks
= i_blocks
>> (inode
->i_blkbits
- 9);
4985 raw_inode
->i_blocks_lo
= cpu_to_le32(i_blocks
);
4986 raw_inode
->i_blocks_high
= cpu_to_le16(i_blocks
>> 32);
4992 * Post the struct inode info into an on-disk inode location in the
4993 * buffer-cache. This gobbles the caller's reference to the
4994 * buffer_head in the inode location struct.
4996 * The caller must have write access to iloc->bh.
4998 static int ext4_do_update_inode(handle_t
*handle
,
4999 struct inode
*inode
,
5000 struct ext4_iloc
*iloc
)
5002 struct ext4_inode
*raw_inode
= ext4_raw_inode(iloc
);
5003 struct ext4_inode_info
*ei
= EXT4_I(inode
);
5004 struct buffer_head
*bh
= iloc
->bh
;
5005 int err
= 0, rc
, block
;
5007 /* For fields not not tracking in the in-memory inode,
5008 * initialise them to zero for new inodes. */
5009 if (ei
->i_state
& EXT4_STATE_NEW
)
5010 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
5012 ext4_get_inode_flags(ei
);
5013 raw_inode
->i_mode
= cpu_to_le16(inode
->i_mode
);
5014 if (!(test_opt(inode
->i_sb
, NO_UID32
))) {
5015 raw_inode
->i_uid_low
= cpu_to_le16(low_16_bits(inode
->i_uid
));
5016 raw_inode
->i_gid_low
= cpu_to_le16(low_16_bits(inode
->i_gid
));
5018 * Fix up interoperability with old kernels. Otherwise, old inodes get
5019 * re-used with the upper 16 bits of the uid/gid intact
5022 raw_inode
->i_uid_high
=
5023 cpu_to_le16(high_16_bits(inode
->i_uid
));
5024 raw_inode
->i_gid_high
=
5025 cpu_to_le16(high_16_bits(inode
->i_gid
));
5027 raw_inode
->i_uid_high
= 0;
5028 raw_inode
->i_gid_high
= 0;
5031 raw_inode
->i_uid_low
=
5032 cpu_to_le16(fs_high2lowuid(inode
->i_uid
));
5033 raw_inode
->i_gid_low
=
5034 cpu_to_le16(fs_high2lowgid(inode
->i_gid
));
5035 raw_inode
->i_uid_high
= 0;
5036 raw_inode
->i_gid_high
= 0;
5038 raw_inode
->i_links_count
= cpu_to_le16(inode
->i_nlink
);
5040 EXT4_INODE_SET_XTIME(i_ctime
, inode
, raw_inode
);
5041 EXT4_INODE_SET_XTIME(i_mtime
, inode
, raw_inode
);
5042 EXT4_INODE_SET_XTIME(i_atime
, inode
, raw_inode
);
5043 EXT4_EINODE_SET_XTIME(i_crtime
, ei
, raw_inode
);
5045 if (ext4_inode_blocks_set(handle
, raw_inode
, ei
))
5047 raw_inode
->i_dtime
= cpu_to_le32(ei
->i_dtime
);
5048 raw_inode
->i_flags
= cpu_to_le32(ei
->i_flags
);
5049 if (EXT4_SB(inode
->i_sb
)->s_es
->s_creator_os
!=
5050 cpu_to_le32(EXT4_OS_HURD
))
5051 raw_inode
->i_file_acl_high
=
5052 cpu_to_le16(ei
->i_file_acl
>> 32);
5053 raw_inode
->i_file_acl_lo
= cpu_to_le32(ei
->i_file_acl
);
5054 ext4_isize_set(raw_inode
, ei
->i_disksize
);
5055 if (ei
->i_disksize
> 0x7fffffffULL
) {
5056 struct super_block
*sb
= inode
->i_sb
;
5057 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
5058 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
) ||
5059 EXT4_SB(sb
)->s_es
->s_rev_level
==
5060 cpu_to_le32(EXT4_GOOD_OLD_REV
)) {
5061 /* If this is the first large file
5062 * created, add a flag to the superblock.
5064 err
= ext4_journal_get_write_access(handle
,
5065 EXT4_SB(sb
)->s_sbh
);
5068 ext4_update_dynamic_rev(sb
);
5069 EXT4_SET_RO_COMPAT_FEATURE(sb
,
5070 EXT4_FEATURE_RO_COMPAT_LARGE_FILE
);
5072 ext4_handle_sync(handle
);
5073 err
= ext4_handle_dirty_metadata(handle
, inode
,
5074 EXT4_SB(sb
)->s_sbh
);
5077 raw_inode
->i_generation
= cpu_to_le32(inode
->i_generation
);
5078 if (S_ISCHR(inode
->i_mode
) || S_ISBLK(inode
->i_mode
)) {
5079 if (old_valid_dev(inode
->i_rdev
)) {
5080 raw_inode
->i_block
[0] =
5081 cpu_to_le32(old_encode_dev(inode
->i_rdev
));
5082 raw_inode
->i_block
[1] = 0;
5084 raw_inode
->i_block
[0] = 0;
5085 raw_inode
->i_block
[1] =
5086 cpu_to_le32(new_encode_dev(inode
->i_rdev
));
5087 raw_inode
->i_block
[2] = 0;
5090 for (block
= 0; block
< EXT4_N_BLOCKS
; block
++)
5091 raw_inode
->i_block
[block
] = ei
->i_data
[block
];
5093 raw_inode
->i_disk_version
= cpu_to_le32(inode
->i_version
);
5094 if (ei
->i_extra_isize
) {
5095 if (EXT4_FITS_IN_INODE(raw_inode
, ei
, i_version_hi
))
5096 raw_inode
->i_version_hi
=
5097 cpu_to_le32(inode
->i_version
>> 32);
5098 raw_inode
->i_extra_isize
= cpu_to_le16(ei
->i_extra_isize
);
5101 BUFFER_TRACE(bh
, "call ext4_handle_dirty_metadata");
5102 rc
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
5105 ei
->i_state
&= ~EXT4_STATE_NEW
;
5109 ext4_std_error(inode
->i_sb
, err
);
5114 * ext4_write_inode()
5116 * We are called from a few places:
5118 * - Within generic_file_write() for O_SYNC files.
5119 * Here, there will be no transaction running. We wait for any running
5120 * trasnaction to commit.
5122 * - Within sys_sync(), kupdate and such.
5123 * We wait on commit, if tol to.
5125 * - Within prune_icache() (PF_MEMALLOC == true)
5126 * Here we simply return. We can't afford to block kswapd on the
5129 * In all cases it is actually safe for us to return without doing anything,
5130 * because the inode has been copied into a raw inode buffer in
5131 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5134 * Note that we are absolutely dependent upon all inode dirtiers doing the
5135 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5136 * which we are interested.
5138 * It would be a bug for them to not do this. The code:
5140 * mark_inode_dirty(inode)
5142 * inode->i_size = expr;
5144 * is in error because a kswapd-driven write_inode() could occur while
5145 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5146 * will no longer be on the superblock's dirty inode list.
5148 int ext4_write_inode(struct inode
*inode
, int wait
)
5152 if (current
->flags
& PF_MEMALLOC
)
5155 if (EXT4_SB(inode
->i_sb
)->s_journal
) {
5156 if (ext4_journal_current_handle()) {
5157 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5165 err
= ext4_force_commit(inode
->i_sb
);
5167 struct ext4_iloc iloc
;
5169 err
= ext4_get_inode_loc(inode
, &iloc
);
5173 sync_dirty_buffer(iloc
.bh
);
5174 if (buffer_req(iloc
.bh
) && !buffer_uptodate(iloc
.bh
)) {
5175 ext4_error(inode
->i_sb
, __func__
,
5176 "IO error syncing inode, "
5177 "inode=%lu, block=%llu",
5179 (unsigned long long)iloc
.bh
->b_blocknr
);
5189 * Called from notify_change.
5191 * We want to trap VFS attempts to truncate the file as soon as
5192 * possible. In particular, we want to make sure that when the VFS
5193 * shrinks i_size, we put the inode on the orphan list and modify
5194 * i_disksize immediately, so that during the subsequent flushing of
5195 * dirty pages and freeing of disk blocks, we can guarantee that any
5196 * commit will leave the blocks being flushed in an unused state on
5197 * disk. (On recovery, the inode will get truncated and the blocks will
5198 * be freed, so we have a strong guarantee that no future commit will
5199 * leave these blocks visible to the user.)
5201 * Another thing we have to assure is that if we are in ordered mode
5202 * and inode is still attached to the committing transaction, we must
5203 * we start writeout of all the dirty pages which are being truncated.
5204 * This way we are sure that all the data written in the previous
5205 * transaction are already on disk (truncate waits for pages under
5208 * Called with inode->i_mutex down.
5210 int ext4_setattr(struct dentry
*dentry
, struct iattr
*attr
)
5212 struct inode
*inode
= dentry
->d_inode
;
5214 const unsigned int ia_valid
= attr
->ia_valid
;
5216 error
= inode_change_ok(inode
, attr
);
5220 if ((ia_valid
& ATTR_UID
&& attr
->ia_uid
!= inode
->i_uid
) ||
5221 (ia_valid
& ATTR_GID
&& attr
->ia_gid
!= inode
->i_gid
)) {
5224 /* (user+group)*(old+new) structure, inode write (sb,
5225 * inode block, ? - but truncate inode update has it) */
5226 handle
= ext4_journal_start(inode
, 2*(EXT4_QUOTA_INIT_BLOCKS(inode
->i_sb
)+
5227 EXT4_QUOTA_DEL_BLOCKS(inode
->i_sb
))+3);
5228 if (IS_ERR(handle
)) {
5229 error
= PTR_ERR(handle
);
5232 error
= vfs_dq_transfer(inode
, attr
) ? -EDQUOT
: 0;
5234 ext4_journal_stop(handle
);
5237 /* Update corresponding info in inode so that everything is in
5238 * one transaction */
5239 if (attr
->ia_valid
& ATTR_UID
)
5240 inode
->i_uid
= attr
->ia_uid
;
5241 if (attr
->ia_valid
& ATTR_GID
)
5242 inode
->i_gid
= attr
->ia_gid
;
5243 error
= ext4_mark_inode_dirty(handle
, inode
);
5244 ext4_journal_stop(handle
);
5247 if (attr
->ia_valid
& ATTR_SIZE
) {
5248 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
)) {
5249 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5251 if (attr
->ia_size
> sbi
->s_bitmap_maxbytes
) {
5258 if (S_ISREG(inode
->i_mode
) &&
5259 attr
->ia_valid
& ATTR_SIZE
&& attr
->ia_size
< inode
->i_size
) {
5262 handle
= ext4_journal_start(inode
, 3);
5263 if (IS_ERR(handle
)) {
5264 error
= PTR_ERR(handle
);
5268 error
= ext4_orphan_add(handle
, inode
);
5269 EXT4_I(inode
)->i_disksize
= attr
->ia_size
;
5270 rc
= ext4_mark_inode_dirty(handle
, inode
);
5273 ext4_journal_stop(handle
);
5275 if (ext4_should_order_data(inode
)) {
5276 error
= ext4_begin_ordered_truncate(inode
,
5279 /* Do as much error cleanup as possible */
5280 handle
= ext4_journal_start(inode
, 3);
5281 if (IS_ERR(handle
)) {
5282 ext4_orphan_del(NULL
, inode
);
5285 ext4_orphan_del(handle
, inode
);
5286 ext4_journal_stop(handle
);
5292 rc
= inode_setattr(inode
, attr
);
5294 /* If inode_setattr's call to ext4_truncate failed to get a
5295 * transaction handle at all, we need to clean up the in-core
5296 * orphan list manually. */
5298 ext4_orphan_del(NULL
, inode
);
5300 if (!rc
&& (ia_valid
& ATTR_MODE
))
5301 rc
= ext4_acl_chmod(inode
);
5304 ext4_std_error(inode
->i_sb
, error
);
5310 int ext4_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
5313 struct inode
*inode
;
5314 unsigned long delalloc_blocks
;
5316 inode
= dentry
->d_inode
;
5317 generic_fillattr(inode
, stat
);
5320 * We can't update i_blocks if the block allocation is delayed
5321 * otherwise in the case of system crash before the real block
5322 * allocation is done, we will have i_blocks inconsistent with
5323 * on-disk file blocks.
5324 * We always keep i_blocks updated together with real
5325 * allocation. But to not confuse with user, stat
5326 * will return the blocks that include the delayed allocation
5327 * blocks for this file.
5329 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
5330 delalloc_blocks
= EXT4_I(inode
)->i_reserved_data_blocks
;
5331 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
5333 stat
->blocks
+= (delalloc_blocks
<< inode
->i_sb
->s_blocksize_bits
)>>9;
5337 static int ext4_indirect_trans_blocks(struct inode
*inode
, int nrblocks
,
5342 /* if nrblocks are contiguous */
5345 * With N contiguous data blocks, it need at most
5346 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5347 * 2 dindirect blocks
5350 indirects
= nrblocks
/ EXT4_ADDR_PER_BLOCK(inode
->i_sb
);
5351 return indirects
+ 3;
5354 * if nrblocks are not contiguous, worse case, each block touch
5355 * a indirect block, and each indirect block touch a double indirect
5356 * block, plus a triple indirect block
5358 indirects
= nrblocks
* 2 + 1;
5362 static int ext4_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5364 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
5365 return ext4_indirect_trans_blocks(inode
, nrblocks
, chunk
);
5366 return ext4_ext_index_trans_blocks(inode
, nrblocks
, chunk
);
5370 * Account for index blocks, block groups bitmaps and block group
5371 * descriptor blocks if modify datablocks and index blocks
5372 * worse case, the indexs blocks spread over different block groups
5374 * If datablocks are discontiguous, they are possible to spread over
5375 * different block groups too. If they are contiugous, with flexbg,
5376 * they could still across block group boundary.
5378 * Also account for superblock, inode, quota and xattr blocks
5380 int ext4_meta_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
5382 ext4_group_t groups
, ngroups
= ext4_get_groups_count(inode
->i_sb
);
5388 * How many index blocks need to touch to modify nrblocks?
5389 * The "Chunk" flag indicating whether the nrblocks is
5390 * physically contiguous on disk
5392 * For Direct IO and fallocate, they calls get_block to allocate
5393 * one single extent at a time, so they could set the "Chunk" flag
5395 idxblocks
= ext4_index_trans_blocks(inode
, nrblocks
, chunk
);
5400 * Now let's see how many group bitmaps and group descriptors need
5410 if (groups
> ngroups
)
5412 if (groups
> EXT4_SB(inode
->i_sb
)->s_gdb_count
)
5413 gdpblocks
= EXT4_SB(inode
->i_sb
)->s_gdb_count
;
5415 /* bitmaps and block group descriptor blocks */
5416 ret
+= groups
+ gdpblocks
;
5418 /* Blocks for super block, inode, quota and xattr blocks */
5419 ret
+= EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
5425 * Calulate the total number of credits to reserve to fit
5426 * the modification of a single pages into a single transaction,
5427 * which may include multiple chunks of block allocations.
5429 * This could be called via ext4_write_begin()
5431 * We need to consider the worse case, when
5432 * one new block per extent.
5434 int ext4_writepage_trans_blocks(struct inode
*inode
)
5436 int bpp
= ext4_journal_blocks_per_page(inode
);
5439 ret
= ext4_meta_trans_blocks(inode
, bpp
, 0);
5441 /* Account for data blocks for journalled mode */
5442 if (ext4_should_journal_data(inode
))
5448 * Calculate the journal credits for a chunk of data modification.
5450 * This is called from DIO, fallocate or whoever calling
5451 * ext4_get_blocks() to map/allocate a chunk of contigous disk blocks.
5453 * journal buffers for data blocks are not included here, as DIO
5454 * and fallocate do no need to journal data buffers.
5456 int ext4_chunk_trans_blocks(struct inode
*inode
, int nrblocks
)
5458 return ext4_meta_trans_blocks(inode
, nrblocks
, 1);
5462 * The caller must have previously called ext4_reserve_inode_write().
5463 * Give this, we know that the caller already has write access to iloc->bh.
5465 int ext4_mark_iloc_dirty(handle_t
*handle
,
5466 struct inode
*inode
, struct ext4_iloc
*iloc
)
5470 if (test_opt(inode
->i_sb
, I_VERSION
))
5471 inode_inc_iversion(inode
);
5473 /* the do_update_inode consumes one bh->b_count */
5476 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5477 err
= ext4_do_update_inode(handle
, inode
, iloc
);
5483 * On success, We end up with an outstanding reference count against
5484 * iloc->bh. This _must_ be cleaned up later.
5488 ext4_reserve_inode_write(handle_t
*handle
, struct inode
*inode
,
5489 struct ext4_iloc
*iloc
)
5493 err
= ext4_get_inode_loc(inode
, iloc
);
5495 BUFFER_TRACE(iloc
->bh
, "get_write_access");
5496 err
= ext4_journal_get_write_access(handle
, iloc
->bh
);
5502 ext4_std_error(inode
->i_sb
, err
);
5507 * Expand an inode by new_extra_isize bytes.
5508 * Returns 0 on success or negative error number on failure.
5510 static int ext4_expand_extra_isize(struct inode
*inode
,
5511 unsigned int new_extra_isize
,
5512 struct ext4_iloc iloc
,
5515 struct ext4_inode
*raw_inode
;
5516 struct ext4_xattr_ibody_header
*header
;
5517 struct ext4_xattr_entry
*entry
;
5519 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
5522 raw_inode
= ext4_raw_inode(&iloc
);
5524 header
= IHDR(inode
, raw_inode
);
5525 entry
= IFIRST(header
);
5527 /* No extended attributes present */
5528 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) ||
5529 header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)) {
5530 memset((void *)raw_inode
+ EXT4_GOOD_OLD_INODE_SIZE
, 0,
5532 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
5536 /* try to expand with EAs present */
5537 return ext4_expand_extra_isize_ea(inode
, new_extra_isize
,
5542 * What we do here is to mark the in-core inode as clean with respect to inode
5543 * dirtiness (it may still be data-dirty).
5544 * This means that the in-core inode may be reaped by prune_icache
5545 * without having to perform any I/O. This is a very good thing,
5546 * because *any* task may call prune_icache - even ones which
5547 * have a transaction open against a different journal.
5549 * Is this cheating? Not really. Sure, we haven't written the
5550 * inode out, but prune_icache isn't a user-visible syncing function.
5551 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5552 * we start and wait on commits.
5554 * Is this efficient/effective? Well, we're being nice to the system
5555 * by cleaning up our inodes proactively so they can be reaped
5556 * without I/O. But we are potentially leaving up to five seconds'
5557 * worth of inodes floating about which prune_icache wants us to
5558 * write out. One way to fix that would be to get prune_icache()
5559 * to do a write_super() to free up some memory. It has the desired
5562 int ext4_mark_inode_dirty(handle_t
*handle
, struct inode
*inode
)
5564 struct ext4_iloc iloc
;
5565 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
5566 static unsigned int mnt_count
;
5570 err
= ext4_reserve_inode_write(handle
, inode
, &iloc
);
5571 if (ext4_handle_valid(handle
) &&
5572 EXT4_I(inode
)->i_extra_isize
< sbi
->s_want_extra_isize
&&
5573 !(EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
)) {
5575 * We need extra buffer credits since we may write into EA block
5576 * with this same handle. If journal_extend fails, then it will
5577 * only result in a minor loss of functionality for that inode.
5578 * If this is felt to be critical, then e2fsck should be run to
5579 * force a large enough s_min_extra_isize.
5581 if ((jbd2_journal_extend(handle
,
5582 EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
))) == 0) {
5583 ret
= ext4_expand_extra_isize(inode
,
5584 sbi
->s_want_extra_isize
,
5587 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
5589 le16_to_cpu(sbi
->s_es
->s_mnt_count
)) {
5590 ext4_warning(inode
->i_sb
, __func__
,
5591 "Unable to expand inode %lu. Delete"
5592 " some EAs or run e2fsck.",
5595 le16_to_cpu(sbi
->s_es
->s_mnt_count
);
5601 err
= ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
5606 * ext4_dirty_inode() is called from __mark_inode_dirty()
5608 * We're really interested in the case where a file is being extended.
5609 * i_size has been changed by generic_commit_write() and we thus need
5610 * to include the updated inode in the current transaction.
5612 * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
5613 * are allocated to the file.
5615 * If the inode is marked synchronous, we don't honour that here - doing
5616 * so would cause a commit on atime updates, which we don't bother doing.
5617 * We handle synchronous inodes at the highest possible level.
5619 void ext4_dirty_inode(struct inode
*inode
)
5623 handle
= ext4_journal_start(inode
, 2);
5627 ext4_mark_inode_dirty(handle
, inode
);
5629 ext4_journal_stop(handle
);
5636 * Bind an inode's backing buffer_head into this transaction, to prevent
5637 * it from being flushed to disk early. Unlike
5638 * ext4_reserve_inode_write, this leaves behind no bh reference and
5639 * returns no iloc structure, so the caller needs to repeat the iloc
5640 * lookup to mark the inode dirty later.
5642 static int ext4_pin_inode(handle_t
*handle
, struct inode
*inode
)
5644 struct ext4_iloc iloc
;
5648 err
= ext4_get_inode_loc(inode
, &iloc
);
5650 BUFFER_TRACE(iloc
.bh
, "get_write_access");
5651 err
= jbd2_journal_get_write_access(handle
, iloc
.bh
);
5653 err
= ext4_handle_dirty_metadata(handle
,
5659 ext4_std_error(inode
->i_sb
, err
);
5664 int ext4_change_inode_journal_flag(struct inode
*inode
, int val
)
5671 * We have to be very careful here: changing a data block's
5672 * journaling status dynamically is dangerous. If we write a
5673 * data block to the journal, change the status and then delete
5674 * that block, we risk forgetting to revoke the old log record
5675 * from the journal and so a subsequent replay can corrupt data.
5676 * So, first we make sure that the journal is empty and that
5677 * nobody is changing anything.
5680 journal
= EXT4_JOURNAL(inode
);
5683 if (is_journal_aborted(journal
))
5686 jbd2_journal_lock_updates(journal
);
5687 jbd2_journal_flush(journal
);
5690 * OK, there are no updates running now, and all cached data is
5691 * synced to disk. We are now in a completely consistent state
5692 * which doesn't have anything in the journal, and we know that
5693 * no filesystem updates are running, so it is safe to modify
5694 * the inode's in-core data-journaling state flag now.
5698 EXT4_I(inode
)->i_flags
|= EXT4_JOURNAL_DATA_FL
;
5700 EXT4_I(inode
)->i_flags
&= ~EXT4_JOURNAL_DATA_FL
;
5701 ext4_set_aops(inode
);
5703 jbd2_journal_unlock_updates(journal
);
5705 /* Finally we can mark the inode as dirty. */
5707 handle
= ext4_journal_start(inode
, 1);
5709 return PTR_ERR(handle
);
5711 err
= ext4_mark_inode_dirty(handle
, inode
);
5712 ext4_handle_sync(handle
);
5713 ext4_journal_stop(handle
);
5714 ext4_std_error(inode
->i_sb
, err
);
5719 static int ext4_bh_unmapped(handle_t
*handle
, struct buffer_head
*bh
)
5721 return !buffer_mapped(bh
);
5724 int ext4_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
5726 struct page
*page
= vmf
->page
;
5731 struct file
*file
= vma
->vm_file
;
5732 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
5733 struct address_space
*mapping
= inode
->i_mapping
;
5736 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5737 * get i_mutex because we are already holding mmap_sem.
5739 down_read(&inode
->i_alloc_sem
);
5740 size
= i_size_read(inode
);
5741 if (page
->mapping
!= mapping
|| size
<= page_offset(page
)
5742 || !PageUptodate(page
)) {
5743 /* page got truncated from under us? */
5747 if (PageMappedToDisk(page
))
5750 if (page
->index
== size
>> PAGE_CACHE_SHIFT
)
5751 len
= size
& ~PAGE_CACHE_MASK
;
5753 len
= PAGE_CACHE_SIZE
;
5757 * return if we have all the buffers mapped. This avoid
5758 * the need to call write_begin/write_end which does a
5759 * journal_start/journal_stop which can block and take
5762 if (page_has_buffers(page
)) {
5763 if (!walk_page_buffers(NULL
, page_buffers(page
), 0, len
, NULL
,
5764 ext4_bh_unmapped
)) {
5771 * OK, we need to fill the hole... Do write_begin write_end
5772 * to do block allocation/reservation.We are not holding
5773 * inode.i__mutex here. That allow * parallel write_begin,
5774 * write_end call. lock_page prevent this from happening
5775 * on the same page though
5777 ret
= mapping
->a_ops
->write_begin(file
, mapping
, page_offset(page
),
5778 len
, AOP_FLAG_UNINTERRUPTIBLE
, &page
, &fsdata
);
5781 ret
= mapping
->a_ops
->write_end(file
, mapping
, page_offset(page
),
5782 len
, len
, page
, fsdata
);
5788 ret
= VM_FAULT_SIGBUS
;
5789 up_read(&inode
->i_alloc_sem
);