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>
41 #include <linux/kernel.h>
42 #include <linux/slab.h>
43 #include <linux/ratelimit.h>
45 #include "ext4_jbd2.h"
48 #include "ext4_extents.h"
50 #include <trace/events/ext4.h>
52 #define MPAGE_DA_EXTENT_TAIL 0x01
54 static inline int ext4_begin_ordered_truncate(struct inode *inode,
57 trace_ext4_begin_ordered_truncate(inode, new_size);
58 return jbd2_journal_begin_ordered_truncate(
59 EXT4_SB(inode->i_sb)->s_journal,
60 &EXT4_I(inode)->jinode,
64 static void ext4_invalidatepage(struct page *page, unsigned long offset);
65 static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
66 struct buffer_head *bh_result, int create);
67 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
68 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
69 static int __ext4_journalled_writepage(struct page *page, unsigned int len);
70 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
73 * Test whether an inode is a fast symlink.
75 static int ext4_inode_is_fast_symlink(struct inode *inode)
77 int ea_blocks = EXT4_I(inode)->i_file_acl ?
78 (inode->i_sb->s_blocksize >> 9) : 0;
80 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
84 * Work out how many blocks we need to proceed with the next chunk of a
85 * truncate transaction.
87 static unsigned long blocks_for_truncate(struct inode *inode)
91 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
93 /* Give ourselves just enough room to cope with inodes in which
94 * i_blocks is corrupt: we've seen disk corruptions in the past
95 * which resulted in random data in an inode which looked enough
96 * like a regular file for ext4 to try to delete it. Things
97 * will go a bit crazy if that happens, but at least we should
98 * try not to panic the whole kernel. */
102 /* But we need to bound the transaction so we don't overflow the
104 if (needed > EXT4_MAX_TRANS_DATA)
105 needed = EXT4_MAX_TRANS_DATA;
107 return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
111 * Truncate transactions can be complex and absolutely huge. So we need to
112 * be able to restart the transaction at a conventient checkpoint to make
113 * sure we don't overflow the journal.
115 * start_transaction gets us a new handle for a truncate transaction,
116 * and extend_transaction tries to extend the existing one a bit. If
117 * extend fails, we need to propagate the failure up and restart the
118 * transaction in the top-level truncate loop. --sct
120 static handle_t *start_transaction(struct inode *inode)
124 result = ext4_journal_start(inode, blocks_for_truncate(inode));
128 ext4_std_error(inode->i_sb, PTR_ERR(result));
133 * Try to extend this transaction for the purposes of truncation.
135 * Returns 0 if we managed to create more room. If we can't create more
136 * room, and the transaction must be restarted we return 1.
138 static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
140 if (!ext4_handle_valid(handle))
142 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
144 if (!ext4_journal_extend(handle, blocks_for_truncate(inode)))
150 * Restart the transaction associated with *handle. This does a commit,
151 * so before we call here everything must be consistently dirtied against
154 int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
160 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
161 * moment, get_block can be called only for blocks inside i_size since
162 * page cache has been already dropped and writes are blocked by
163 * i_mutex. So we can safely drop the i_data_sem here.
165 BUG_ON(EXT4_JOURNAL(inode) == NULL);
166 jbd_debug(2, "restarting handle %p\n", handle);
167 up_write(&EXT4_I(inode)->i_data_sem);
168 ret = ext4_journal_restart(handle, blocks_for_truncate(inode));
169 down_write(&EXT4_I(inode)->i_data_sem);
170 ext4_discard_preallocations(inode);
176 * Called at the last iput() if i_nlink is zero.
178 void ext4_evict_inode(struct inode *inode)
183 trace_ext4_evict_inode(inode);
184 if (inode->i_nlink) {
185 truncate_inode_pages(&inode->i_data, 0);
189 if (!is_bad_inode(inode))
190 dquot_initialize(inode);
192 if (ext4_should_order_data(inode))
193 ext4_begin_ordered_truncate(inode, 0);
194 truncate_inode_pages(&inode->i_data, 0);
196 if (is_bad_inode(inode))
199 handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
200 if (IS_ERR(handle)) {
201 ext4_std_error(inode->i_sb, PTR_ERR(handle));
203 * If we're going to skip the normal cleanup, we still need to
204 * make sure that the in-core orphan linked list is properly
207 ext4_orphan_del(NULL, inode);
212 ext4_handle_sync(handle);
214 err = ext4_mark_inode_dirty(handle, inode);
216 ext4_warning(inode->i_sb,
217 "couldn't mark inode dirty (err %d)", err);
221 ext4_truncate(inode);
224 * ext4_ext_truncate() doesn't reserve any slop when it
225 * restarts journal transactions; therefore there may not be
226 * enough credits left in the handle to remove the inode from
227 * the orphan list and set the dtime field.
229 if (!ext4_handle_has_enough_credits(handle, 3)) {
230 err = ext4_journal_extend(handle, 3);
232 err = ext4_journal_restart(handle, 3);
234 ext4_warning(inode->i_sb,
235 "couldn't extend journal (err %d)", err);
237 ext4_journal_stop(handle);
238 ext4_orphan_del(NULL, inode);
244 * Kill off the orphan record which ext4_truncate created.
245 * AKPM: I think this can be inside the above `if'.
246 * Note that ext4_orphan_del() has to be able to cope with the
247 * deletion of a non-existent orphan - this is because we don't
248 * know if ext4_truncate() actually created an orphan record.
249 * (Well, we could do this if we need to, but heck - it works)
251 ext4_orphan_del(handle, inode);
252 EXT4_I(inode)->i_dtime = get_seconds();
255 * One subtle ordering requirement: if anything has gone wrong
256 * (transaction abort, IO errors, whatever), then we can still
257 * do these next steps (the fs will already have been marked as
258 * having errors), but we can't free the inode if the mark_dirty
261 if (ext4_mark_inode_dirty(handle, inode))
262 /* If that failed, just do the required in-core inode clear. */
263 ext4_clear_inode(inode);
265 ext4_free_inode(handle, inode);
266 ext4_journal_stop(handle);
269 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
275 struct buffer_head *bh;
278 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
280 p->key = *(p->p = v);
285 * ext4_block_to_path - parse the block number into array of offsets
286 * @inode: inode in question (we are only interested in its superblock)
287 * @i_block: block number to be parsed
288 * @offsets: array to store the offsets in
289 * @boundary: set this non-zero if the referred-to block is likely to be
290 * followed (on disk) by an indirect block.
292 * To store the locations of file's data ext4 uses a data structure common
293 * for UNIX filesystems - tree of pointers anchored in the inode, with
294 * data blocks at leaves and indirect blocks in intermediate nodes.
295 * This function translates the block number into path in that tree -
296 * return value is the path length and @offsets[n] is the offset of
297 * pointer to (n+1)th node in the nth one. If @block is out of range
298 * (negative or too large) warning is printed and zero returned.
300 * Note: function doesn't find node addresses, so no IO is needed. All
301 * we need to know is the capacity of indirect blocks (taken from the
306 * Portability note: the last comparison (check that we fit into triple
307 * indirect block) is spelled differently, because otherwise on an
308 * architecture with 32-bit longs and 8Kb pages we might get into trouble
309 * if our filesystem had 8Kb blocks. We might use long long, but that would
310 * kill us on x86. Oh, well, at least the sign propagation does not matter -
311 * i_block would have to be negative in the very beginning, so we would not
315 static int ext4_block_to_path(struct inode *inode,
317 ext4_lblk_t offsets[4], int *boundary)
319 int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
320 int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
321 const long direct_blocks = EXT4_NDIR_BLOCKS,
322 indirect_blocks = ptrs,
323 double_blocks = (1 << (ptrs_bits * 2));
327 if (i_block < direct_blocks) {
328 offsets[n++] = i_block;
329 final = direct_blocks;
330 } else if ((i_block -= direct_blocks) < indirect_blocks) {
331 offsets[n++] = EXT4_IND_BLOCK;
332 offsets[n++] = i_block;
334 } else if ((i_block -= indirect_blocks) < double_blocks) {
335 offsets[n++] = EXT4_DIND_BLOCK;
336 offsets[n++] = i_block >> ptrs_bits;
337 offsets[n++] = i_block & (ptrs - 1);
339 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
340 offsets[n++] = EXT4_TIND_BLOCK;
341 offsets[n++] = i_block >> (ptrs_bits * 2);
342 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
343 offsets[n++] = i_block & (ptrs - 1);
346 ext4_warning(inode->i_sb, "block %lu > max in inode %lu",
347 i_block + direct_blocks +
348 indirect_blocks + double_blocks, inode->i_ino);
351 *boundary = final - 1 - (i_block & (ptrs - 1));
355 static int __ext4_check_blockref(const char *function, unsigned int line,
357 __le32 *p, unsigned int max)
359 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
363 while (bref < p+max) {
364 blk = le32_to_cpu(*bref++);
366 unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb),
368 es->s_last_error_block = cpu_to_le64(blk);
369 ext4_error_inode(inode, function, line, blk,
378 #define ext4_check_indirect_blockref(inode, bh) \
379 __ext4_check_blockref(__func__, __LINE__, inode, \
380 (__le32 *)(bh)->b_data, \
381 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
383 #define ext4_check_inode_blockref(inode) \
384 __ext4_check_blockref(__func__, __LINE__, inode, \
385 EXT4_I(inode)->i_data, \
389 * ext4_get_branch - read the chain of indirect blocks leading to data
390 * @inode: inode in question
391 * @depth: depth of the chain (1 - direct pointer, etc.)
392 * @offsets: offsets of pointers in inode/indirect blocks
393 * @chain: place to store the result
394 * @err: here we store the error value
396 * Function fills the array of triples <key, p, bh> and returns %NULL
397 * if everything went OK or the pointer to the last filled triple
398 * (incomplete one) otherwise. Upon the return chain[i].key contains
399 * the number of (i+1)-th block in the chain (as it is stored in memory,
400 * i.e. little-endian 32-bit), chain[i].p contains the address of that
401 * number (it points into struct inode for i==0 and into the bh->b_data
402 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
403 * block for i>0 and NULL for i==0. In other words, it holds the block
404 * numbers of the chain, addresses they were taken from (and where we can
405 * verify that chain did not change) and buffer_heads hosting these
408 * Function stops when it stumbles upon zero pointer (absent block)
409 * (pointer to last triple returned, *@err == 0)
410 * or when it gets an IO error reading an indirect block
411 * (ditto, *@err == -EIO)
412 * or when it reads all @depth-1 indirect blocks successfully and finds
413 * the whole chain, all way to the data (returns %NULL, *err == 0).
415 * Need to be called with
416 * down_read(&EXT4_I(inode)->i_data_sem)
418 static Indirect *ext4_get_branch(struct inode *inode, int depth,
419 ext4_lblk_t *offsets,
420 Indirect chain[4], int *err)
422 struct super_block *sb = inode->i_sb;
424 struct buffer_head *bh;
427 /* i_data is not going away, no lock needed */
428 add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
432 bh = sb_getblk(sb, le32_to_cpu(p->key));
436 if (!bh_uptodate_or_lock(bh)) {
437 if (bh_submit_read(bh) < 0) {
441 /* validate block references */
442 if (ext4_check_indirect_blockref(inode, bh)) {
448 add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
462 * ext4_find_near - find a place for allocation with sufficient locality
464 * @ind: descriptor of indirect block.
466 * This function returns the preferred place for block allocation.
467 * It is used when heuristic for sequential allocation fails.
469 * + if there is a block to the left of our position - allocate near it.
470 * + if pointer will live in indirect block - allocate near that block.
471 * + if pointer will live in inode - allocate in the same
474 * In the latter case we colour the starting block by the callers PID to
475 * prevent it from clashing with concurrent allocations for a different inode
476 * in the same block group. The PID is used here so that functionally related
477 * files will be close-by on-disk.
479 * Caller must make sure that @ind is valid and will stay that way.
481 static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
483 struct ext4_inode_info *ei = EXT4_I(inode);
484 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
486 ext4_fsblk_t bg_start;
487 ext4_fsblk_t last_block;
488 ext4_grpblk_t colour;
489 ext4_group_t block_group;
490 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
492 /* Try to find previous block */
493 for (p = ind->p - 1; p >= start; p--) {
495 return le32_to_cpu(*p);
498 /* No such thing, so let's try location of indirect block */
500 return ind->bh->b_blocknr;
503 * It is going to be referred to from the inode itself? OK, just put it
504 * into the same cylinder group then.
506 block_group = ei->i_block_group;
507 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
508 block_group &= ~(flex_size-1);
509 if (S_ISREG(inode->i_mode))
512 bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
513 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
516 * If we are doing delayed allocation, we don't need take
517 * colour into account.
519 if (test_opt(inode->i_sb, DELALLOC))
522 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
523 colour = (current->pid % 16) *
524 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
526 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
527 return bg_start + colour;
531 * ext4_find_goal - find a preferred place for allocation.
533 * @block: block we want
534 * @partial: pointer to the last triple within a chain
536 * Normally this function find the preferred place for block allocation,
538 * Because this is only used for non-extent files, we limit the block nr
541 static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
547 * XXX need to get goal block from mballoc's data structures
550 goal = ext4_find_near(inode, partial);
551 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
556 * ext4_blks_to_allocate - Look up the block map and count the number
557 * of direct blocks need to be allocated for the given branch.
559 * @branch: chain of indirect blocks
560 * @k: number of blocks need for indirect blocks
561 * @blks: number of data blocks to be mapped.
562 * @blocks_to_boundary: the offset in the indirect block
564 * return the total number of blocks to be allocate, including the
565 * direct and indirect blocks.
567 static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
568 int blocks_to_boundary)
570 unsigned int count = 0;
573 * Simple case, [t,d]Indirect block(s) has not allocated yet
574 * then it's clear blocks on that path have not allocated
577 /* right now we don't handle cross boundary allocation */
578 if (blks < blocks_to_boundary + 1)
581 count += blocks_to_boundary + 1;
586 while (count < blks && count <= blocks_to_boundary &&
587 le32_to_cpu(*(branch[0].p + count)) == 0) {
594 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
595 * @handle: handle for this transaction
596 * @inode: inode which needs allocated blocks
597 * @iblock: the logical block to start allocated at
598 * @goal: preferred physical block of allocation
599 * @indirect_blks: the number of blocks need to allocate for indirect
601 * @blks: number of desired blocks
602 * @new_blocks: on return it will store the new block numbers for
603 * the indirect blocks(if needed) and the first direct block,
604 * @err: on return it will store the error code
606 * This function will return the number of blocks allocated as
607 * requested by the passed-in parameters.
609 static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
610 ext4_lblk_t iblock, ext4_fsblk_t goal,
611 int indirect_blks, int blks,
612 ext4_fsblk_t new_blocks[4], int *err)
614 struct ext4_allocation_request ar;
616 unsigned long count = 0, blk_allocated = 0;
618 ext4_fsblk_t current_block = 0;
622 * Here we try to allocate the requested multiple blocks at once,
623 * on a best-effort basis.
624 * To build a branch, we should allocate blocks for
625 * the indirect blocks(if not allocated yet), and at least
626 * the first direct block of this branch. That's the
627 * minimum number of blocks need to allocate(required)
629 /* first we try to allocate the indirect blocks */
630 target = indirect_blks;
633 /* allocating blocks for indirect blocks and direct blocks */
634 current_block = ext4_new_meta_blocks(handle, inode,
639 if (unlikely(current_block + count > EXT4_MAX_BLOCK_FILE_PHYS)) {
640 EXT4_ERROR_INODE(inode,
641 "current_block %llu + count %lu > %d!",
642 current_block, count,
643 EXT4_MAX_BLOCK_FILE_PHYS);
649 /* allocate blocks for indirect blocks */
650 while (index < indirect_blks && count) {
651 new_blocks[index++] = current_block++;
656 * save the new block number
657 * for the first direct block
659 new_blocks[index] = current_block;
660 printk(KERN_INFO "%s returned more blocks than "
661 "requested\n", __func__);
667 target = blks - count ;
668 blk_allocated = count;
671 /* Now allocate data blocks */
672 memset(&ar, 0, sizeof(ar));
677 if (S_ISREG(inode->i_mode))
678 /* enable in-core preallocation only for regular files */
679 ar.flags = EXT4_MB_HINT_DATA;
681 current_block = ext4_mb_new_blocks(handle, &ar, err);
682 if (unlikely(current_block + ar.len > EXT4_MAX_BLOCK_FILE_PHYS)) {
683 EXT4_ERROR_INODE(inode,
684 "current_block %llu + ar.len %d > %d!",
685 current_block, ar.len,
686 EXT4_MAX_BLOCK_FILE_PHYS);
691 if (*err && (target == blks)) {
693 * if the allocation failed and we didn't allocate
699 if (target == blks) {
701 * save the new block number
702 * for the first direct block
704 new_blocks[index] = current_block;
706 blk_allocated += ar.len;
709 /* total number of blocks allocated for direct blocks */
714 for (i = 0; i < index; i++)
715 ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
720 * ext4_alloc_branch - allocate and set up a chain of blocks.
721 * @handle: handle for this transaction
723 * @indirect_blks: number of allocated indirect blocks
724 * @blks: number of allocated direct blocks
725 * @goal: preferred place for allocation
726 * @offsets: offsets (in the blocks) to store the pointers to next.
727 * @branch: place to store the chain in.
729 * This function allocates blocks, zeroes out all but the last one,
730 * links them into chain and (if we are synchronous) writes them to disk.
731 * In other words, it prepares a branch that can be spliced onto the
732 * inode. It stores the information about that chain in the branch[], in
733 * the same format as ext4_get_branch() would do. We are calling it after
734 * we had read the existing part of chain and partial points to the last
735 * triple of that (one with zero ->key). Upon the exit we have the same
736 * picture as after the successful ext4_get_block(), except that in one
737 * place chain is disconnected - *branch->p is still zero (we did not
738 * set the last link), but branch->key contains the number that should
739 * be placed into *branch->p to fill that gap.
741 * If allocation fails we free all blocks we've allocated (and forget
742 * their buffer_heads) and return the error value the from failed
743 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
744 * as described above and return 0.
746 static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
747 ext4_lblk_t iblock, int indirect_blks,
748 int *blks, ext4_fsblk_t goal,
749 ext4_lblk_t *offsets, Indirect *branch)
751 int blocksize = inode->i_sb->s_blocksize;
754 struct buffer_head *bh;
756 ext4_fsblk_t new_blocks[4];
757 ext4_fsblk_t current_block;
759 num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
760 *blks, new_blocks, &err);
764 branch[0].key = cpu_to_le32(new_blocks[0]);
766 * metadata blocks and data blocks are allocated.
768 for (n = 1; n <= indirect_blks; n++) {
770 * Get buffer_head for parent block, zero it out
771 * and set the pointer to new one, then send
774 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
782 BUFFER_TRACE(bh, "call get_create_access");
783 err = ext4_journal_get_create_access(handle, bh);
785 /* Don't brelse(bh) here; it's done in
786 * ext4_journal_forget() below */
791 memset(bh->b_data, 0, blocksize);
792 branch[n].p = (__le32 *) bh->b_data + offsets[n];
793 branch[n].key = cpu_to_le32(new_blocks[n]);
794 *branch[n].p = branch[n].key;
795 if (n == indirect_blks) {
796 current_block = new_blocks[n];
798 * End of chain, update the last new metablock of
799 * the chain to point to the new allocated
800 * data blocks numbers
802 for (i = 1; i < num; i++)
803 *(branch[n].p + i) = cpu_to_le32(++current_block);
805 BUFFER_TRACE(bh, "marking uptodate");
806 set_buffer_uptodate(bh);
809 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
810 err = ext4_handle_dirty_metadata(handle, inode, bh);
817 /* Allocation failed, free what we already allocated */
818 ext4_free_blocks(handle, inode, 0, new_blocks[0], 1, 0);
819 for (i = 1; i <= n ; i++) {
821 * branch[i].bh is newly allocated, so there is no
822 * need to revoke the block, which is why we don't
823 * need to set EXT4_FREE_BLOCKS_METADATA.
825 ext4_free_blocks(handle, inode, 0, new_blocks[i], 1,
826 EXT4_FREE_BLOCKS_FORGET);
828 for (i = n+1; i < indirect_blks; i++)
829 ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
831 ext4_free_blocks(handle, inode, 0, new_blocks[i], num, 0);
837 * ext4_splice_branch - splice the allocated branch onto inode.
838 * @handle: handle for this transaction
840 * @block: (logical) number of block we are adding
841 * @chain: chain of indirect blocks (with a missing link - see
843 * @where: location of missing link
844 * @num: number of indirect blocks we are adding
845 * @blks: number of direct blocks we are adding
847 * This function fills the missing link and does all housekeeping needed in
848 * inode (->i_blocks, etc.). In case of success we end up with the full
849 * chain to new block and return 0.
851 static int ext4_splice_branch(handle_t *handle, struct inode *inode,
852 ext4_lblk_t block, Indirect *where, int num,
857 ext4_fsblk_t current_block;
860 * If we're splicing into a [td]indirect block (as opposed to the
861 * inode) then we need to get write access to the [td]indirect block
865 BUFFER_TRACE(where->bh, "get_write_access");
866 err = ext4_journal_get_write_access(handle, where->bh);
872 *where->p = where->key;
875 * Update the host buffer_head or inode to point to more just allocated
876 * direct blocks blocks
878 if (num == 0 && blks > 1) {
879 current_block = le32_to_cpu(where->key) + 1;
880 for (i = 1; i < blks; i++)
881 *(where->p + i) = cpu_to_le32(current_block++);
884 /* We are done with atomic stuff, now do the rest of housekeeping */
885 /* had we spliced it onto indirect block? */
888 * If we spliced it onto an indirect block, we haven't
889 * altered the inode. Note however that if it is being spliced
890 * onto an indirect block at the very end of the file (the
891 * file is growing) then we *will* alter the inode to reflect
892 * the new i_size. But that is not done here - it is done in
893 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
895 jbd_debug(5, "splicing indirect only\n");
896 BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
897 err = ext4_handle_dirty_metadata(handle, inode, where->bh);
902 * OK, we spliced it into the inode itself on a direct block.
904 ext4_mark_inode_dirty(handle, inode);
905 jbd_debug(5, "splicing direct\n");
910 for (i = 1; i <= num; i++) {
912 * branch[i].bh is newly allocated, so there is no
913 * need to revoke the block, which is why we don't
914 * need to set EXT4_FREE_BLOCKS_METADATA.
916 ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
917 EXT4_FREE_BLOCKS_FORGET);
919 ext4_free_blocks(handle, inode, 0, le32_to_cpu(where[num].key),
926 * The ext4_ind_map_blocks() function handles non-extents inodes
927 * (i.e., using the traditional indirect/double-indirect i_blocks
928 * scheme) for ext4_map_blocks().
930 * Allocation strategy is simple: if we have to allocate something, we will
931 * have to go the whole way to leaf. So let's do it before attaching anything
932 * to tree, set linkage between the newborn blocks, write them if sync is
933 * required, recheck the path, free and repeat if check fails, otherwise
934 * set the last missing link (that will protect us from any truncate-generated
935 * removals - all blocks on the path are immune now) and possibly force the
936 * write on the parent block.
937 * That has a nice additional property: no special recovery from the failed
938 * allocations is needed - we simply release blocks and do not touch anything
939 * reachable from inode.
941 * `handle' can be NULL if create == 0.
943 * return > 0, # of blocks mapped or allocated.
944 * return = 0, if plain lookup failed.
945 * return < 0, error case.
947 * The ext4_ind_get_blocks() function should be called with
948 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
949 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
950 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
953 static int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
954 struct ext4_map_blocks *map,
958 ext4_lblk_t offsets[4];
963 int blocks_to_boundary = 0;
966 ext4_fsblk_t first_block = 0;
968 J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
969 J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
970 depth = ext4_block_to_path(inode, map->m_lblk, offsets,
971 &blocks_to_boundary);
976 partial = ext4_get_branch(inode, depth, offsets, chain, &err);
978 /* Simplest case - block found, no allocation needed */
980 first_block = le32_to_cpu(chain[depth - 1].key);
983 while (count < map->m_len && count <= blocks_to_boundary) {
986 blk = le32_to_cpu(*(chain[depth-1].p + count));
988 if (blk == first_block + count)
996 /* Next simple case - plain lookup or failed read of indirect block */
997 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
1001 * Okay, we need to do block allocation.
1003 goal = ext4_find_goal(inode, map->m_lblk, partial);
1005 /* the number of blocks need to allocate for [d,t]indirect blocks */
1006 indirect_blks = (chain + depth) - partial - 1;
1009 * Next look up the indirect map to count the totoal number of
1010 * direct blocks to allocate for this branch.
1012 count = ext4_blks_to_allocate(partial, indirect_blks,
1013 map->m_len, blocks_to_boundary);
1015 * Block out ext4_truncate while we alter the tree
1017 err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks,
1019 offsets + (partial - chain), partial);
1022 * The ext4_splice_branch call will free and forget any buffers
1023 * on the new chain if there is a failure, but that risks using
1024 * up transaction credits, especially for bitmaps where the
1025 * credits cannot be returned. Can we handle this somehow? We
1026 * may need to return -EAGAIN upwards in the worst case. --sct
1029 err = ext4_splice_branch(handle, inode, map->m_lblk,
1030 partial, indirect_blks, count);
1034 map->m_flags |= EXT4_MAP_NEW;
1036 ext4_update_inode_fsync_trans(handle, inode, 1);
1038 map->m_flags |= EXT4_MAP_MAPPED;
1039 map->m_pblk = le32_to_cpu(chain[depth-1].key);
1041 if (count > blocks_to_boundary)
1042 map->m_flags |= EXT4_MAP_BOUNDARY;
1044 /* Clean up and exit */
1045 partial = chain + depth - 1; /* the whole chain */
1047 while (partial > chain) {
1048 BUFFER_TRACE(partial->bh, "call brelse");
1049 brelse(partial->bh);
1057 qsize_t *ext4_get_reserved_space(struct inode *inode)
1059 return &EXT4_I(inode)->i_reserved_quota;
1064 * Calculate the number of metadata blocks need to reserve
1065 * to allocate a new block at @lblocks for non extent file based file
1067 static int ext4_indirect_calc_metadata_amount(struct inode *inode,
1070 struct ext4_inode_info *ei = EXT4_I(inode);
1071 sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1);
1074 if (lblock < EXT4_NDIR_BLOCKS)
1077 lblock -= EXT4_NDIR_BLOCKS;
1079 if (ei->i_da_metadata_calc_len &&
1080 (lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) {
1081 ei->i_da_metadata_calc_len++;
1084 ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
1085 ei->i_da_metadata_calc_len = 1;
1086 blk_bits = order_base_2(lblock);
1087 return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
1091 * Calculate the number of metadata blocks need to reserve
1092 * to allocate a block located at @lblock
1094 static int ext4_calc_metadata_amount(struct inode *inode, sector_t lblock)
1096 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1097 return ext4_ext_calc_metadata_amount(inode, lblock);
1099 return ext4_indirect_calc_metadata_amount(inode, lblock);
1103 * Called with i_data_sem down, which is important since we can call
1104 * ext4_discard_preallocations() from here.
1106 void ext4_da_update_reserve_space(struct inode *inode,
1107 int used, int quota_claim)
1109 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1110 struct ext4_inode_info *ei = EXT4_I(inode);
1112 spin_lock(&ei->i_block_reservation_lock);
1113 trace_ext4_da_update_reserve_space(inode, used);
1114 if (unlikely(used > ei->i_reserved_data_blocks)) {
1115 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d "
1116 "with only %d reserved data blocks\n",
1117 __func__, inode->i_ino, used,
1118 ei->i_reserved_data_blocks);
1120 used = ei->i_reserved_data_blocks;
1123 /* Update per-inode reservations */
1124 ei->i_reserved_data_blocks -= used;
1125 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
1126 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1127 used + ei->i_allocated_meta_blocks);
1128 ei->i_allocated_meta_blocks = 0;
1130 if (ei->i_reserved_data_blocks == 0) {
1132 * We can release all of the reserved metadata blocks
1133 * only when we have written all of the delayed
1134 * allocation blocks.
1136 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1137 ei->i_reserved_meta_blocks);
1138 ei->i_reserved_meta_blocks = 0;
1139 ei->i_da_metadata_calc_len = 0;
1141 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1143 /* Update quota subsystem for data blocks */
1145 dquot_claim_block(inode, used);
1148 * We did fallocate with an offset that is already delayed
1149 * allocated. So on delayed allocated writeback we should
1150 * not re-claim the quota for fallocated blocks.
1152 dquot_release_reservation_block(inode, used);
1156 * If we have done all the pending block allocations and if
1157 * there aren't any writers on the inode, we can discard the
1158 * inode's preallocations.
1160 if ((ei->i_reserved_data_blocks == 0) &&
1161 (atomic_read(&inode->i_writecount) == 0))
1162 ext4_discard_preallocations(inode);
1165 static int __check_block_validity(struct inode *inode, const char *func,
1167 struct ext4_map_blocks *map)
1169 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
1171 ext4_error_inode(inode, func, line, map->m_pblk,
1172 "lblock %lu mapped to illegal pblock "
1173 "(length %d)", (unsigned long) map->m_lblk,
1180 #define check_block_validity(inode, map) \
1181 __check_block_validity((inode), __func__, __LINE__, (map))
1184 * Return the number of contiguous dirty pages in a given inode
1185 * starting at page frame idx.
1187 static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
1188 unsigned int max_pages)
1190 struct address_space *mapping = inode->i_mapping;
1192 struct pagevec pvec;
1194 int i, nr_pages, done = 0;
1198 pagevec_init(&pvec, 0);
1201 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1202 PAGECACHE_TAG_DIRTY,
1203 (pgoff_t)PAGEVEC_SIZE);
1206 for (i = 0; i < nr_pages; i++) {
1207 struct page *page = pvec.pages[i];
1208 struct buffer_head *bh, *head;
1211 if (unlikely(page->mapping != mapping) ||
1213 PageWriteback(page) ||
1214 page->index != idx) {
1219 if (page_has_buffers(page)) {
1220 bh = head = page_buffers(page);
1222 if (!buffer_delay(bh) &&
1223 !buffer_unwritten(bh))
1225 bh = bh->b_this_page;
1226 } while (!done && (bh != head));
1233 if (num >= max_pages) {
1238 pagevec_release(&pvec);
1244 * The ext4_map_blocks() function tries to look up the requested blocks,
1245 * and returns if the blocks are already mapped.
1247 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1248 * and store the allocated blocks in the result buffer head and mark it
1251 * If file type is extents based, it will call ext4_ext_map_blocks(),
1252 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
1255 * On success, it returns the number of blocks being mapped or allocate.
1256 * if create==0 and the blocks are pre-allocated and uninitialized block,
1257 * the result buffer head is unmapped. If the create ==1, it will make sure
1258 * the buffer head is mapped.
1260 * It returns 0 if plain look up failed (blocks have not been allocated), in
1261 * that casem, buffer head is unmapped
1263 * It returns the error in case of allocation failure.
1265 int ext4_map_blocks(handle_t *handle, struct inode *inode,
1266 struct ext4_map_blocks *map, int flags)
1271 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
1272 "logical block %lu\n", inode->i_ino, flags, map->m_len,
1273 (unsigned long) map->m_lblk);
1275 * Try to see if we can get the block without requesting a new
1276 * file system block.
1278 down_read((&EXT4_I(inode)->i_data_sem));
1279 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
1280 retval = ext4_ext_map_blocks(handle, inode, map, 0);
1282 retval = ext4_ind_map_blocks(handle, inode, map, 0);
1284 up_read((&EXT4_I(inode)->i_data_sem));
1286 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
1287 int ret = check_block_validity(inode, map);
1292 /* If it is only a block(s) look up */
1293 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
1297 * Returns if the blocks have already allocated
1299 * Note that if blocks have been preallocated
1300 * ext4_ext_get_block() returns th create = 0
1301 * with buffer head unmapped.
1303 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
1307 * When we call get_blocks without the create flag, the
1308 * BH_Unwritten flag could have gotten set if the blocks
1309 * requested were part of a uninitialized extent. We need to
1310 * clear this flag now that we are committed to convert all or
1311 * part of the uninitialized extent to be an initialized
1312 * extent. This is because we need to avoid the combination
1313 * of BH_Unwritten and BH_Mapped flags being simultaneously
1314 * set on the buffer_head.
1316 map->m_flags &= ~EXT4_MAP_UNWRITTEN;
1319 * New blocks allocate and/or writing to uninitialized extent
1320 * will possibly result in updating i_data, so we take
1321 * the write lock of i_data_sem, and call get_blocks()
1322 * with create == 1 flag.
1324 down_write((&EXT4_I(inode)->i_data_sem));
1327 * if the caller is from delayed allocation writeout path
1328 * we have already reserved fs blocks for allocation
1329 * let the underlying get_block() function know to
1330 * avoid double accounting
1332 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1333 EXT4_I(inode)->i_delalloc_reserved_flag = 1;
1335 * We need to check for EXT4 here because migrate
1336 * could have changed the inode type in between
1338 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
1339 retval = ext4_ext_map_blocks(handle, inode, map, flags);
1341 retval = ext4_ind_map_blocks(handle, inode, map, flags);
1343 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
1345 * We allocated new blocks which will result in
1346 * i_data's format changing. Force the migrate
1347 * to fail by clearing migrate flags
1349 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
1353 * Update reserved blocks/metadata blocks after successful
1354 * block allocation which had been deferred till now. We don't
1355 * support fallocate for non extent files. So we can update
1356 * reserve space here.
1359 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
1360 ext4_da_update_reserve_space(inode, retval, 1);
1362 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1363 EXT4_I(inode)->i_delalloc_reserved_flag = 0;
1365 up_write((&EXT4_I(inode)->i_data_sem));
1366 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
1367 int ret = check_block_validity(inode, map);
1374 /* Maximum number of blocks we map for direct IO at once. */
1375 #define DIO_MAX_BLOCKS 4096
1377 static int _ext4_get_block(struct inode *inode, sector_t iblock,
1378 struct buffer_head *bh, int flags)
1380 handle_t *handle = ext4_journal_current_handle();
1381 struct ext4_map_blocks map;
1382 int ret = 0, started = 0;
1385 map.m_lblk = iblock;
1386 map.m_len = bh->b_size >> inode->i_blkbits;
1388 if (flags && !handle) {
1389 /* Direct IO write... */
1390 if (map.m_len > DIO_MAX_BLOCKS)
1391 map.m_len = DIO_MAX_BLOCKS;
1392 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
1393 handle = ext4_journal_start(inode, dio_credits);
1394 if (IS_ERR(handle)) {
1395 ret = PTR_ERR(handle);
1401 ret = ext4_map_blocks(handle, inode, &map, flags);
1403 map_bh(bh, inode->i_sb, map.m_pblk);
1404 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1405 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
1409 ext4_journal_stop(handle);
1413 int ext4_get_block(struct inode *inode, sector_t iblock,
1414 struct buffer_head *bh, int create)
1416 return _ext4_get_block(inode, iblock, bh,
1417 create ? EXT4_GET_BLOCKS_CREATE : 0);
1421 * `handle' can be NULL if create is zero
1423 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
1424 ext4_lblk_t block, int create, int *errp)
1426 struct ext4_map_blocks map;
1427 struct buffer_head *bh;
1430 J_ASSERT(handle != NULL || create == 0);
1434 err = ext4_map_blocks(handle, inode, &map,
1435 create ? EXT4_GET_BLOCKS_CREATE : 0);
1443 bh = sb_getblk(inode->i_sb, map.m_pblk);
1448 if (map.m_flags & EXT4_MAP_NEW) {
1449 J_ASSERT(create != 0);
1450 J_ASSERT(handle != NULL);
1453 * Now that we do not always journal data, we should
1454 * keep in mind whether this should always journal the
1455 * new buffer as metadata. For now, regular file
1456 * writes use ext4_get_block instead, so it's not a
1460 BUFFER_TRACE(bh, "call get_create_access");
1461 fatal = ext4_journal_get_create_access(handle, bh);
1462 if (!fatal && !buffer_uptodate(bh)) {
1463 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
1464 set_buffer_uptodate(bh);
1467 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1468 err = ext4_handle_dirty_metadata(handle, inode, bh);
1472 BUFFER_TRACE(bh, "not a new buffer");
1482 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
1483 ext4_lblk_t block, int create, int *err)
1485 struct buffer_head *bh;
1487 bh = ext4_getblk(handle, inode, block, create, err);
1490 if (buffer_uptodate(bh))
1492 ll_rw_block(READ_META, 1, &bh);
1494 if (buffer_uptodate(bh))
1501 static int walk_page_buffers(handle_t *handle,
1502 struct buffer_head *head,
1506 int (*fn)(handle_t *handle,
1507 struct buffer_head *bh))
1509 struct buffer_head *bh;
1510 unsigned block_start, block_end;
1511 unsigned blocksize = head->b_size;
1513 struct buffer_head *next;
1515 for (bh = head, block_start = 0;
1516 ret == 0 && (bh != head || !block_start);
1517 block_start = block_end, bh = next) {
1518 next = bh->b_this_page;
1519 block_end = block_start + blocksize;
1520 if (block_end <= from || block_start >= to) {
1521 if (partial && !buffer_uptodate(bh))
1525 err = (*fn)(handle, bh);
1533 * To preserve ordering, it is essential that the hole instantiation and
1534 * the data write be encapsulated in a single transaction. We cannot
1535 * close off a transaction and start a new one between the ext4_get_block()
1536 * and the commit_write(). So doing the jbd2_journal_start at the start of
1537 * prepare_write() is the right place.
1539 * Also, this function can nest inside ext4_writepage() ->
1540 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1541 * has generated enough buffer credits to do the whole page. So we won't
1542 * block on the journal in that case, which is good, because the caller may
1545 * By accident, ext4 can be reentered when a transaction is open via
1546 * quota file writes. If we were to commit the transaction while thus
1547 * reentered, there can be a deadlock - we would be holding a quota
1548 * lock, and the commit would never complete if another thread had a
1549 * transaction open and was blocking on the quota lock - a ranking
1552 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1553 * will _not_ run commit under these circumstances because handle->h_ref
1554 * is elevated. We'll still have enough credits for the tiny quotafile
1557 static int do_journal_get_write_access(handle_t *handle,
1558 struct buffer_head *bh)
1560 int dirty = buffer_dirty(bh);
1563 if (!buffer_mapped(bh) || buffer_freed(bh))
1566 * __block_write_begin() could have dirtied some buffers. Clean
1567 * the dirty bit as jbd2_journal_get_write_access() could complain
1568 * otherwise about fs integrity issues. Setting of the dirty bit
1569 * by __block_write_begin() isn't a real problem here as we clear
1570 * the bit before releasing a page lock and thus writeback cannot
1571 * ever write the buffer.
1574 clear_buffer_dirty(bh);
1575 ret = ext4_journal_get_write_access(handle, bh);
1577 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1582 * Truncate blocks that were not used by write. We have to truncate the
1583 * pagecache as well so that corresponding buffers get properly unmapped.
1585 static void ext4_truncate_failed_write(struct inode *inode)
1587 truncate_inode_pages(inode->i_mapping, inode->i_size);
1588 ext4_truncate(inode);
1591 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
1592 struct buffer_head *bh_result, int create);
1593 static int ext4_write_begin(struct file *file, struct address_space *mapping,
1594 loff_t pos, unsigned len, unsigned flags,
1595 struct page **pagep, void **fsdata)
1597 struct inode *inode = mapping->host;
1598 int ret, needed_blocks;
1605 trace_ext4_write_begin(inode, pos, len, flags);
1607 * Reserve one block more for addition to orphan list in case
1608 * we allocate blocks but write fails for some reason
1610 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
1611 index = pos >> PAGE_CACHE_SHIFT;
1612 from = pos & (PAGE_CACHE_SIZE - 1);
1616 handle = ext4_journal_start(inode, needed_blocks);
1617 if (IS_ERR(handle)) {
1618 ret = PTR_ERR(handle);
1622 /* We cannot recurse into the filesystem as the transaction is already
1624 flags |= AOP_FLAG_NOFS;
1626 page = grab_cache_page_write_begin(mapping, index, flags);
1628 ext4_journal_stop(handle);
1634 if (ext4_should_dioread_nolock(inode))
1635 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
1637 ret = __block_write_begin(page, pos, len, ext4_get_block);
1639 if (!ret && ext4_should_journal_data(inode)) {
1640 ret = walk_page_buffers(handle, page_buffers(page),
1641 from, to, NULL, do_journal_get_write_access);
1646 page_cache_release(page);
1648 * __block_write_begin may have instantiated a few blocks
1649 * outside i_size. Trim these off again. Don't need
1650 * i_size_read because we hold i_mutex.
1652 * Add inode to orphan list in case we crash before
1655 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1656 ext4_orphan_add(handle, inode);
1658 ext4_journal_stop(handle);
1659 if (pos + len > inode->i_size) {
1660 ext4_truncate_failed_write(inode);
1662 * If truncate failed early the inode might
1663 * still be on the orphan list; we need to
1664 * make sure the inode is removed from the
1665 * orphan list in that case.
1668 ext4_orphan_del(NULL, inode);
1672 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1678 /* For write_end() in data=journal mode */
1679 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1681 if (!buffer_mapped(bh) || buffer_freed(bh))
1683 set_buffer_uptodate(bh);
1684 return ext4_handle_dirty_metadata(handle, NULL, bh);
1687 static int ext4_generic_write_end(struct file *file,
1688 struct address_space *mapping,
1689 loff_t pos, unsigned len, unsigned copied,
1690 struct page *page, void *fsdata)
1692 int i_size_changed = 0;
1693 struct inode *inode = mapping->host;
1694 handle_t *handle = ext4_journal_current_handle();
1696 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1699 * No need to use i_size_read() here, the i_size
1700 * cannot change under us because we hold i_mutex.
1702 * But it's important to update i_size while still holding page lock:
1703 * page writeout could otherwise come in and zero beyond i_size.
1705 if (pos + copied > inode->i_size) {
1706 i_size_write(inode, pos + copied);
1710 if (pos + copied > EXT4_I(inode)->i_disksize) {
1711 /* We need to mark inode dirty even if
1712 * new_i_size is less that inode->i_size
1713 * bu greater than i_disksize.(hint delalloc)
1715 ext4_update_i_disksize(inode, (pos + copied));
1719 page_cache_release(page);
1722 * Don't mark the inode dirty under page lock. First, it unnecessarily
1723 * makes the holding time of page lock longer. Second, it forces lock
1724 * ordering of page lock and transaction start for journaling
1728 ext4_mark_inode_dirty(handle, inode);
1734 * We need to pick up the new inode size which generic_commit_write gave us
1735 * `file' can be NULL - eg, when called from page_symlink().
1737 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1738 * buffers are managed internally.
1740 static int ext4_ordered_write_end(struct file *file,
1741 struct address_space *mapping,
1742 loff_t pos, unsigned len, unsigned copied,
1743 struct page *page, void *fsdata)
1745 handle_t *handle = ext4_journal_current_handle();
1746 struct inode *inode = mapping->host;
1749 trace_ext4_ordered_write_end(inode, pos, len, copied);
1750 ret = ext4_jbd2_file_inode(handle, inode);
1753 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1756 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1757 /* if we have allocated more blocks and copied
1758 * less. We will have blocks allocated outside
1759 * inode->i_size. So truncate them
1761 ext4_orphan_add(handle, inode);
1765 ret2 = ext4_journal_stop(handle);
1769 if (pos + len > inode->i_size) {
1770 ext4_truncate_failed_write(inode);
1772 * If truncate failed early the inode might still be
1773 * on the orphan list; we need to make sure the inode
1774 * is removed from the orphan list in that case.
1777 ext4_orphan_del(NULL, inode);
1781 return ret ? ret : copied;
1784 static int ext4_writeback_write_end(struct file *file,
1785 struct address_space *mapping,
1786 loff_t pos, unsigned len, unsigned copied,
1787 struct page *page, void *fsdata)
1789 handle_t *handle = ext4_journal_current_handle();
1790 struct inode *inode = mapping->host;
1793 trace_ext4_writeback_write_end(inode, pos, len, copied);
1794 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1797 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1798 /* if we have allocated more blocks and copied
1799 * less. We will have blocks allocated outside
1800 * inode->i_size. So truncate them
1802 ext4_orphan_add(handle, inode);
1807 ret2 = ext4_journal_stop(handle);
1811 if (pos + len > inode->i_size) {
1812 ext4_truncate_failed_write(inode);
1814 * If truncate failed early the inode might still be
1815 * on the orphan list; we need to make sure the inode
1816 * is removed from the orphan list in that case.
1819 ext4_orphan_del(NULL, inode);
1822 return ret ? ret : copied;
1825 static int ext4_journalled_write_end(struct file *file,
1826 struct address_space *mapping,
1827 loff_t pos, unsigned len, unsigned copied,
1828 struct page *page, void *fsdata)
1830 handle_t *handle = ext4_journal_current_handle();
1831 struct inode *inode = mapping->host;
1837 trace_ext4_journalled_write_end(inode, pos, len, copied);
1838 from = pos & (PAGE_CACHE_SIZE - 1);
1842 if (!PageUptodate(page))
1844 page_zero_new_buffers(page, from+copied, to);
1847 ret = walk_page_buffers(handle, page_buffers(page), from,
1848 to, &partial, write_end_fn);
1850 SetPageUptodate(page);
1851 new_i_size = pos + copied;
1852 if (new_i_size > inode->i_size)
1853 i_size_write(inode, pos+copied);
1854 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1855 if (new_i_size > EXT4_I(inode)->i_disksize) {
1856 ext4_update_i_disksize(inode, new_i_size);
1857 ret2 = ext4_mark_inode_dirty(handle, inode);
1863 page_cache_release(page);
1864 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1865 /* if we have allocated more blocks and copied
1866 * less. We will have blocks allocated outside
1867 * inode->i_size. So truncate them
1869 ext4_orphan_add(handle, inode);
1871 ret2 = ext4_journal_stop(handle);
1874 if (pos + len > inode->i_size) {
1875 ext4_truncate_failed_write(inode);
1877 * If truncate failed early the inode might still be
1878 * on the orphan list; we need to make sure the inode
1879 * is removed from the orphan list in that case.
1882 ext4_orphan_del(NULL, inode);
1885 return ret ? ret : copied;
1889 * Reserve a single block located at lblock
1891 static int ext4_da_reserve_space(struct inode *inode, sector_t lblock)
1894 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1895 struct ext4_inode_info *ei = EXT4_I(inode);
1896 unsigned long md_needed;
1900 * recalculate the amount of metadata blocks to reserve
1901 * in order to allocate nrblocks
1902 * worse case is one extent per block
1905 spin_lock(&ei->i_block_reservation_lock);
1906 md_needed = ext4_calc_metadata_amount(inode, lblock);
1907 trace_ext4_da_reserve_space(inode, md_needed);
1908 spin_unlock(&ei->i_block_reservation_lock);
1911 * We will charge metadata quota at writeout time; this saves
1912 * us from metadata over-estimation, though we may go over by
1913 * a small amount in the end. Here we just reserve for data.
1915 ret = dquot_reserve_block(inode, 1);
1919 * We do still charge estimated metadata to the sb though;
1920 * we cannot afford to run out of free blocks.
1922 if (ext4_claim_free_blocks(sbi, md_needed + 1)) {
1923 dquot_release_reservation_block(inode, 1);
1924 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1930 spin_lock(&ei->i_block_reservation_lock);
1931 ei->i_reserved_data_blocks++;
1932 ei->i_reserved_meta_blocks += md_needed;
1933 spin_unlock(&ei->i_block_reservation_lock);
1935 return 0; /* success */
1938 static void ext4_da_release_space(struct inode *inode, int to_free)
1940 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1941 struct ext4_inode_info *ei = EXT4_I(inode);
1944 return; /* Nothing to release, exit */
1946 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1948 trace_ext4_da_release_space(inode, to_free);
1949 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1951 * if there aren't enough reserved blocks, then the
1952 * counter is messed up somewhere. Since this
1953 * function is called from invalidate page, it's
1954 * harmless to return without any action.
1956 ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: "
1957 "ino %lu, to_free %d with only %d reserved "
1958 "data blocks\n", inode->i_ino, to_free,
1959 ei->i_reserved_data_blocks);
1961 to_free = ei->i_reserved_data_blocks;
1963 ei->i_reserved_data_blocks -= to_free;
1965 if (ei->i_reserved_data_blocks == 0) {
1967 * We can release all of the reserved metadata blocks
1968 * only when we have written all of the delayed
1969 * allocation blocks.
1971 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1972 ei->i_reserved_meta_blocks);
1973 ei->i_reserved_meta_blocks = 0;
1974 ei->i_da_metadata_calc_len = 0;
1977 /* update fs dirty data blocks counter */
1978 percpu_counter_sub(&sbi->s_dirtyblocks_counter, to_free);
1980 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1982 dquot_release_reservation_block(inode, to_free);
1985 static void ext4_da_page_release_reservation(struct page *page,
1986 unsigned long offset)
1989 struct buffer_head *head, *bh;
1990 unsigned int curr_off = 0;
1992 head = page_buffers(page);
1995 unsigned int next_off = curr_off + bh->b_size;
1997 if ((offset <= curr_off) && (buffer_delay(bh))) {
1999 clear_buffer_delay(bh);
2001 curr_off = next_off;
2002 } while ((bh = bh->b_this_page) != head);
2003 ext4_da_release_space(page->mapping->host, to_release);
2007 * Delayed allocation stuff
2011 * mpage_da_submit_io - walks through extent of pages and try to write
2012 * them with writepage() call back
2014 * @mpd->inode: inode
2015 * @mpd->first_page: first page of the extent
2016 * @mpd->next_page: page after the last page of the extent
2018 * By the time mpage_da_submit_io() is called we expect all blocks
2019 * to be allocated. this may be wrong if allocation failed.
2021 * As pages are already locked by write_cache_pages(), we can't use it
2023 static int mpage_da_submit_io(struct mpage_da_data *mpd,
2024 struct ext4_map_blocks *map)
2026 struct pagevec pvec;
2027 unsigned long index, end;
2028 int ret = 0, err, nr_pages, i;
2029 struct inode *inode = mpd->inode;
2030 struct address_space *mapping = inode->i_mapping;
2031 loff_t size = i_size_read(inode);
2032 unsigned int len, block_start;
2033 struct buffer_head *bh, *page_bufs = NULL;
2034 int journal_data = ext4_should_journal_data(inode);
2035 sector_t pblock = 0, cur_logical = 0;
2036 struct ext4_io_submit io_submit;
2038 BUG_ON(mpd->next_page <= mpd->first_page);
2039 memset(&io_submit, 0, sizeof(io_submit));
2041 * We need to start from the first_page to the next_page - 1
2042 * to make sure we also write the mapped dirty buffer_heads.
2043 * If we look at mpd->b_blocknr we would only be looking
2044 * at the currently mapped buffer_heads.
2046 index = mpd->first_page;
2047 end = mpd->next_page - 1;
2049 pagevec_init(&pvec, 0);
2050 while (index <= end) {
2051 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2054 for (i = 0; i < nr_pages; i++) {
2055 int commit_write = 0, redirty_page = 0;
2056 struct page *page = pvec.pages[i];
2058 index = page->index;
2062 if (index == size >> PAGE_CACHE_SHIFT)
2063 len = size & ~PAGE_CACHE_MASK;
2065 len = PAGE_CACHE_SIZE;
2067 cur_logical = index << (PAGE_CACHE_SHIFT -
2069 pblock = map->m_pblk + (cur_logical -
2074 BUG_ON(!PageLocked(page));
2075 BUG_ON(PageWriteback(page));
2078 * If the page does not have buffers (for
2079 * whatever reason), try to create them using
2080 * __block_write_begin. If this fails,
2081 * redirty the page and move on.
2083 if (!page_has_buffers(page)) {
2084 if (__block_write_begin(page, 0, len,
2085 noalloc_get_block_write)) {
2087 redirty_page_for_writepage(mpd->wbc,
2095 bh = page_bufs = page_buffers(page);
2100 if (map && (cur_logical >= map->m_lblk) &&
2101 (cur_logical <= (map->m_lblk +
2102 (map->m_len - 1)))) {
2103 if (buffer_delay(bh)) {
2104 clear_buffer_delay(bh);
2105 bh->b_blocknr = pblock;
2107 if (buffer_unwritten(bh) ||
2109 BUG_ON(bh->b_blocknr != pblock);
2110 if (map->m_flags & EXT4_MAP_UNINIT)
2111 set_buffer_uninit(bh);
2112 clear_buffer_unwritten(bh);
2115 /* redirty page if block allocation undone */
2116 if (buffer_delay(bh) || buffer_unwritten(bh))
2118 bh = bh->b_this_page;
2119 block_start += bh->b_size;
2122 } while (bh != page_bufs);
2128 /* mark the buffer_heads as dirty & uptodate */
2129 block_commit_write(page, 0, len);
2132 * Delalloc doesn't support data journalling,
2133 * but eventually maybe we'll lift this
2136 if (unlikely(journal_data && PageChecked(page)))
2137 err = __ext4_journalled_writepage(page, len);
2138 else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT))
2139 err = ext4_bio_write_page(&io_submit, page,
2142 err = block_write_full_page(page,
2143 noalloc_get_block_write, mpd->wbc);
2146 mpd->pages_written++;
2148 * In error case, we have to continue because
2149 * remaining pages are still locked
2154 pagevec_release(&pvec);
2156 ext4_io_submit(&io_submit);
2160 static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
2161 sector_t logical, long blk_cnt)
2165 struct pagevec pvec;
2166 struct inode *inode = mpd->inode;
2167 struct address_space *mapping = inode->i_mapping;
2169 index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
2170 end = (logical + blk_cnt - 1) >>
2171 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2172 while (index <= end) {
2173 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2176 for (i = 0; i < nr_pages; i++) {
2177 struct page *page = pvec.pages[i];
2178 if (page->index > end)
2180 BUG_ON(!PageLocked(page));
2181 BUG_ON(PageWriteback(page));
2182 block_invalidatepage(page, 0);
2183 ClearPageUptodate(page);
2186 index = pvec.pages[nr_pages - 1]->index + 1;
2187 pagevec_release(&pvec);
2192 static void ext4_print_free_blocks(struct inode *inode)
2194 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2195 printk(KERN_CRIT "Total free blocks count %lld\n",
2196 ext4_count_free_blocks(inode->i_sb));
2197 printk(KERN_CRIT "Free/Dirty block details\n");
2198 printk(KERN_CRIT "free_blocks=%lld\n",
2199 (long long) percpu_counter_sum(&sbi->s_freeblocks_counter));
2200 printk(KERN_CRIT "dirty_blocks=%lld\n",
2201 (long long) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2202 printk(KERN_CRIT "Block reservation details\n");
2203 printk(KERN_CRIT "i_reserved_data_blocks=%u\n",
2204 EXT4_I(inode)->i_reserved_data_blocks);
2205 printk(KERN_CRIT "i_reserved_meta_blocks=%u\n",
2206 EXT4_I(inode)->i_reserved_meta_blocks);
2211 * mpage_da_map_and_submit - go through given space, map them
2212 * if necessary, and then submit them for I/O
2214 * @mpd - bh describing space
2216 * The function skips space we know is already mapped to disk blocks.
2219 static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
2221 int err, blks, get_blocks_flags;
2222 struct ext4_map_blocks map, *mapp = NULL;
2223 sector_t next = mpd->b_blocknr;
2224 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
2225 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
2226 handle_t *handle = NULL;
2229 * If the blocks are mapped already, or we couldn't accumulate
2230 * any blocks, then proceed immediately to the submission stage.
2232 if ((mpd->b_size == 0) ||
2233 ((mpd->b_state & (1 << BH_Mapped)) &&
2234 !(mpd->b_state & (1 << BH_Delay)) &&
2235 !(mpd->b_state & (1 << BH_Unwritten))))
2238 handle = ext4_journal_current_handle();
2242 * Call ext4_map_blocks() to allocate any delayed allocation
2243 * blocks, or to convert an uninitialized extent to be
2244 * initialized (in the case where we have written into
2245 * one or more preallocated blocks).
2247 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2248 * indicate that we are on the delayed allocation path. This
2249 * affects functions in many different parts of the allocation
2250 * call path. This flag exists primarily because we don't
2251 * want to change *many* call functions, so ext4_map_blocks()
2252 * will set the magic i_delalloc_reserved_flag once the
2253 * inode's allocation semaphore is taken.
2255 * If the blocks in questions were delalloc blocks, set
2256 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2257 * variables are updated after the blocks have been allocated.
2260 map.m_len = max_blocks;
2261 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
2262 if (ext4_should_dioread_nolock(mpd->inode))
2263 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
2264 if (mpd->b_state & (1 << BH_Delay))
2265 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
2267 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
2269 struct super_block *sb = mpd->inode->i_sb;
2273 * If get block returns EAGAIN or ENOSPC and there
2274 * appears to be free blocks we will call
2275 * ext4_writepage() for all of the pages which will
2276 * just redirty the pages.
2281 if (err == -ENOSPC &&
2282 ext4_count_free_blocks(sb)) {
2288 * get block failure will cause us to loop in
2289 * writepages, because a_ops->writepage won't be able
2290 * to make progress. The page will be redirtied by
2291 * writepage and writepages will again try to write
2294 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
2295 ext4_msg(sb, KERN_CRIT,
2296 "delayed block allocation failed for inode %lu "
2297 "at logical offset %llu with max blocks %zd "
2298 "with error %d", mpd->inode->i_ino,
2299 (unsigned long long) next,
2300 mpd->b_size >> mpd->inode->i_blkbits, err);
2301 ext4_msg(sb, KERN_CRIT,
2302 "This should not happen!! Data will be lost\n");
2304 ext4_print_free_blocks(mpd->inode);
2306 /* invalidate all the pages */
2307 ext4_da_block_invalidatepages(mpd, next,
2308 mpd->b_size >> mpd->inode->i_blkbits);
2314 if (map.m_flags & EXT4_MAP_NEW) {
2315 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
2318 for (i = 0; i < map.m_len; i++)
2319 unmap_underlying_metadata(bdev, map.m_pblk + i);
2322 if (ext4_should_order_data(mpd->inode)) {
2323 err = ext4_jbd2_file_inode(handle, mpd->inode);
2325 /* This only happens if the journal is aborted */
2330 * Update on-disk size along with block allocation.
2332 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
2333 if (disksize > i_size_read(mpd->inode))
2334 disksize = i_size_read(mpd->inode);
2335 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
2336 ext4_update_i_disksize(mpd->inode, disksize);
2337 err = ext4_mark_inode_dirty(handle, mpd->inode);
2339 ext4_error(mpd->inode->i_sb,
2340 "Failed to mark inode %lu dirty",
2345 mpage_da_submit_io(mpd, mapp);
2349 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2350 (1 << BH_Delay) | (1 << BH_Unwritten))
2353 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2355 * @mpd->lbh - extent of blocks
2356 * @logical - logical number of the block in the file
2357 * @bh - bh of the block (used to access block's state)
2359 * the function is used to collect contig. blocks in same state
2361 static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
2362 sector_t logical, size_t b_size,
2363 unsigned long b_state)
2366 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
2369 * XXX Don't go larger than mballoc is willing to allocate
2370 * This is a stopgap solution. We eventually need to fold
2371 * mpage_da_submit_io() into this function and then call
2372 * ext4_map_blocks() multiple times in a loop
2374 if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize)
2377 /* check if thereserved journal credits might overflow */
2378 if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) {
2379 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
2381 * With non-extent format we are limited by the journal
2382 * credit available. Total credit needed to insert
2383 * nrblocks contiguous blocks is dependent on the
2384 * nrblocks. So limit nrblocks.
2387 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
2388 EXT4_MAX_TRANS_DATA) {
2390 * Adding the new buffer_head would make it cross the
2391 * allowed limit for which we have journal credit
2392 * reserved. So limit the new bh->b_size
2394 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
2395 mpd->inode->i_blkbits;
2396 /* we will do mpage_da_submit_io in the next loop */
2400 * First block in the extent
2402 if (mpd->b_size == 0) {
2403 mpd->b_blocknr = logical;
2404 mpd->b_size = b_size;
2405 mpd->b_state = b_state & BH_FLAGS;
2409 next = mpd->b_blocknr + nrblocks;
2411 * Can we merge the block to our big extent?
2413 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
2414 mpd->b_size += b_size;
2420 * We couldn't merge the block to our extent, so we
2421 * need to flush current extent and start new one
2423 mpage_da_map_and_submit(mpd);
2427 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
2429 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
2433 * __mpage_da_writepage - finds extent of pages and blocks
2435 * @page: page to consider
2436 * @wbc: not used, we just follow rules
2439 * The function finds extents of pages and scan them for all blocks.
2441 static int __mpage_da_writepage(struct page *page,
2442 struct writeback_control *wbc,
2443 struct mpage_da_data *mpd)
2445 struct inode *inode = mpd->inode;
2446 struct buffer_head *bh, *head;
2450 * Can we merge this page to current extent?
2452 if (mpd->next_page != page->index) {
2454 * Nope, we can't. So, we map non-allocated blocks
2455 * and start IO on them
2457 if (mpd->next_page != mpd->first_page) {
2458 mpage_da_map_and_submit(mpd);
2460 * skip rest of the page in the page_vec
2462 redirty_page_for_writepage(wbc, page);
2464 return MPAGE_DA_EXTENT_TAIL;
2468 * Start next extent of pages ...
2470 mpd->first_page = page->index;
2480 mpd->next_page = page->index + 1;
2481 logical = (sector_t) page->index <<
2482 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2484 if (!page_has_buffers(page)) {
2485 mpage_add_bh_to_extent(mpd, logical, PAGE_CACHE_SIZE,
2486 (1 << BH_Dirty) | (1 << BH_Uptodate));
2488 return MPAGE_DA_EXTENT_TAIL;
2491 * Page with regular buffer heads, just add all dirty ones
2493 head = page_buffers(page);
2496 BUG_ON(buffer_locked(bh));
2498 * We need to try to allocate
2499 * unmapped blocks in the same page.
2500 * Otherwise we won't make progress
2501 * with the page in ext4_writepage
2503 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2504 mpage_add_bh_to_extent(mpd, logical,
2508 return MPAGE_DA_EXTENT_TAIL;
2509 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2511 * mapped dirty buffer. We need to update
2512 * the b_state because we look at
2513 * b_state in mpage_da_map_blocks. We don't
2514 * update b_size because if we find an
2515 * unmapped buffer_head later we need to
2516 * use the b_state flag of that buffer_head.
2518 if (mpd->b_size == 0)
2519 mpd->b_state = bh->b_state & BH_FLAGS;
2522 } while ((bh = bh->b_this_page) != head);
2529 * This is a special get_blocks_t callback which is used by
2530 * ext4_da_write_begin(). It will either return mapped block or
2531 * reserve space for a single block.
2533 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2534 * We also have b_blocknr = -1 and b_bdev initialized properly
2536 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2537 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2538 * initialized properly.
2540 static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2541 struct buffer_head *bh, int create)
2543 struct ext4_map_blocks map;
2545 sector_t invalid_block = ~((sector_t) 0xffff);
2547 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
2550 BUG_ON(create == 0);
2551 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
2553 map.m_lblk = iblock;
2557 * first, we need to know whether the block is allocated already
2558 * preallocated blocks are unmapped but should treated
2559 * the same as allocated blocks.
2561 ret = ext4_map_blocks(NULL, inode, &map, 0);
2565 if (buffer_delay(bh))
2566 return 0; /* Not sure this could or should happen */
2568 * XXX: __block_write_begin() unmaps passed block, is it OK?
2570 ret = ext4_da_reserve_space(inode, iblock);
2572 /* not enough space to reserve */
2575 map_bh(bh, inode->i_sb, invalid_block);
2577 set_buffer_delay(bh);
2581 map_bh(bh, inode->i_sb, map.m_pblk);
2582 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
2584 if (buffer_unwritten(bh)) {
2585 /* A delayed write to unwritten bh should be marked
2586 * new and mapped. Mapped ensures that we don't do
2587 * get_block multiple times when we write to the same
2588 * offset and new ensures that we do proper zero out
2589 * for partial write.
2592 set_buffer_mapped(bh);
2598 * This function is used as a standard get_block_t calback function
2599 * when there is no desire to allocate any blocks. It is used as a
2600 * callback function for block_write_begin() and block_write_full_page().
2601 * These functions should only try to map a single block at a time.
2603 * Since this function doesn't do block allocations even if the caller
2604 * requests it by passing in create=1, it is critically important that
2605 * any caller checks to make sure that any buffer heads are returned
2606 * by this function are either all already mapped or marked for
2607 * delayed allocation before calling block_write_full_page(). Otherwise,
2608 * b_blocknr could be left unitialized, and the page write functions will
2609 * be taken by surprise.
2611 static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
2612 struct buffer_head *bh_result, int create)
2614 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
2615 return _ext4_get_block(inode, iblock, bh_result, 0);
2618 static int bget_one(handle_t *handle, struct buffer_head *bh)
2624 static int bput_one(handle_t *handle, struct buffer_head *bh)
2630 static int __ext4_journalled_writepage(struct page *page,
2633 struct address_space *mapping = page->mapping;
2634 struct inode *inode = mapping->host;
2635 struct buffer_head *page_bufs;
2636 handle_t *handle = NULL;
2640 ClearPageChecked(page);
2641 page_bufs = page_buffers(page);
2643 walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
2644 /* As soon as we unlock the page, it can go away, but we have
2645 * references to buffers so we are safe */
2648 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
2649 if (IS_ERR(handle)) {
2650 ret = PTR_ERR(handle);
2654 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2655 do_journal_get_write_access);
2657 err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2661 err = ext4_journal_stop(handle);
2665 walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
2666 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
2671 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
2672 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
2675 * Note that we don't need to start a transaction unless we're journaling data
2676 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2677 * need to file the inode to the transaction's list in ordered mode because if
2678 * we are writing back data added by write(), the inode is already there and if
2679 * we are writing back data modified via mmap(), noone guarantees in which
2680 * transaction the data will hit the disk. In case we are journaling data, we
2681 * cannot start transaction directly because transaction start ranks above page
2682 * lock so we have to do some magic.
2684 * This function can get called via...
2685 * - ext4_da_writepages after taking page lock (have journal handle)
2686 * - journal_submit_inode_data_buffers (no journal handle)
2687 * - shrink_page_list via pdflush (no journal handle)
2688 * - grab_page_cache when doing write_begin (have journal handle)
2690 * We don't do any block allocation in this function. If we have page with
2691 * multiple blocks we need to write those buffer_heads that are mapped. This
2692 * is important for mmaped based write. So if we do with blocksize 1K
2693 * truncate(f, 1024);
2694 * a = mmap(f, 0, 4096);
2696 * truncate(f, 4096);
2697 * we have in the page first buffer_head mapped via page_mkwrite call back
2698 * but other bufer_heads would be unmapped but dirty(dirty done via the
2699 * do_wp_page). So writepage should write the first block. If we modify
2700 * the mmap area beyond 1024 we will again get a page_fault and the
2701 * page_mkwrite callback will do the block allocation and mark the
2702 * buffer_heads mapped.
2704 * We redirty the page if we have any buffer_heads that is either delay or
2705 * unwritten in the page.
2707 * We can get recursively called as show below.
2709 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2712 * But since we don't do any block allocation we should not deadlock.
2713 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2715 static int ext4_writepage(struct page *page,
2716 struct writeback_control *wbc)
2718 int ret = 0, commit_write = 0;
2721 struct buffer_head *page_bufs = NULL;
2722 struct inode *inode = page->mapping->host;
2724 trace_ext4_writepage(inode, page);
2725 size = i_size_read(inode);
2726 if (page->index == size >> PAGE_CACHE_SHIFT)
2727 len = size & ~PAGE_CACHE_MASK;
2729 len = PAGE_CACHE_SIZE;
2732 * If the page does not have buffers (for whatever reason),
2733 * try to create them using __block_write_begin. If this
2734 * fails, redirty the page and move on.
2736 if (!page_has_buffers(page)) {
2737 if (__block_write_begin(page, 0, len,
2738 noalloc_get_block_write)) {
2740 redirty_page_for_writepage(wbc, page);
2746 page_bufs = page_buffers(page);
2747 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2748 ext4_bh_delay_or_unwritten)) {
2750 * We don't want to do block allocation, so redirty
2751 * the page and return. We may reach here when we do
2752 * a journal commit via journal_submit_inode_data_buffers.
2753 * We can also reach here via shrink_page_list
2758 /* now mark the buffer_heads as dirty and uptodate */
2759 block_commit_write(page, 0, len);
2761 if (PageChecked(page) && ext4_should_journal_data(inode))
2763 * It's mmapped pagecache. Add buffers and journal it. There
2764 * doesn't seem much point in redirtying the page here.
2766 return __ext4_journalled_writepage(page, len);
2768 if (buffer_uninit(page_bufs)) {
2769 ext4_set_bh_endio(page_bufs, inode);
2770 ret = block_write_full_page_endio(page, noalloc_get_block_write,
2771 wbc, ext4_end_io_buffer_write);
2773 ret = block_write_full_page(page, noalloc_get_block_write,
2780 * This is called via ext4_da_writepages() to
2781 * calulate the total number of credits to reserve to fit
2782 * a single extent allocation into a single transaction,
2783 * ext4_da_writpeages() will loop calling this before
2784 * the block allocation.
2787 static int ext4_da_writepages_trans_blocks(struct inode *inode)
2789 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2792 * With non-extent format the journal credit needed to
2793 * insert nrblocks contiguous block is dependent on
2794 * number of contiguous block. So we will limit
2795 * number of contiguous block to a sane value
2797 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
2798 (max_blocks > EXT4_MAX_TRANS_DATA))
2799 max_blocks = EXT4_MAX_TRANS_DATA;
2801 return ext4_chunk_trans_blocks(inode, max_blocks);
2805 * write_cache_pages_da - walk the list of dirty pages of the given
2806 * address space and call the callback function (which usually writes
2809 * This is a forked version of write_cache_pages(). Differences:
2810 * Range cyclic is ignored.
2811 * no_nrwrite_index_update is always presumed true
2813 static int write_cache_pages_da(struct address_space *mapping,
2814 struct writeback_control *wbc,
2815 struct mpage_da_data *mpd,
2816 pgoff_t *done_index)
2820 struct pagevec pvec;
2823 pgoff_t end; /* Inclusive */
2824 long nr_to_write = wbc->nr_to_write;
2827 pagevec_init(&pvec, 0);
2828 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2829 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2831 if (wbc->sync_mode == WB_SYNC_ALL)
2832 tag = PAGECACHE_TAG_TOWRITE;
2834 tag = PAGECACHE_TAG_DIRTY;
2836 *done_index = index;
2837 while (!done && (index <= end)) {
2840 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2841 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2845 for (i = 0; i < nr_pages; i++) {
2846 struct page *page = pvec.pages[i];
2849 * At this point, the page may be truncated or
2850 * invalidated (changing page->mapping to NULL), or
2851 * even swizzled back from swapper_space to tmpfs file
2852 * mapping. However, page->index will not change
2853 * because we have a reference on the page.
2855 if (page->index > end) {
2860 *done_index = page->index + 1;
2865 * Page truncated or invalidated. We can freely skip it
2866 * then, even for data integrity operations: the page
2867 * has disappeared concurrently, so there could be no
2868 * real expectation of this data interity operation
2869 * even if there is now a new, dirty page at the same
2870 * pagecache address.
2872 if (unlikely(page->mapping != mapping)) {
2878 if (!PageDirty(page)) {
2879 /* someone wrote it for us */
2880 goto continue_unlock;
2883 if (PageWriteback(page)) {
2884 if (wbc->sync_mode != WB_SYNC_NONE)
2885 wait_on_page_writeback(page);
2887 goto continue_unlock;
2890 BUG_ON(PageWriteback(page));
2891 if (!clear_page_dirty_for_io(page))
2892 goto continue_unlock;
2894 ret = __mpage_da_writepage(page, wbc, mpd);
2895 if (unlikely(ret)) {
2896 if (ret == AOP_WRITEPAGE_ACTIVATE) {
2905 if (nr_to_write > 0) {
2907 if (nr_to_write == 0 &&
2908 wbc->sync_mode == WB_SYNC_NONE) {
2910 * We stop writing back only if we are
2911 * not doing integrity sync. In case of
2912 * integrity sync we have to keep going
2913 * because someone may be concurrently
2914 * dirtying pages, and we might have
2915 * synced a lot of newly appeared dirty
2916 * pages, but have not synced all of the
2924 pagevec_release(&pvec);
2931 static int ext4_da_writepages(struct address_space *mapping,
2932 struct writeback_control *wbc)
2935 int range_whole = 0;
2936 handle_t *handle = NULL;
2937 struct mpage_da_data mpd;
2938 struct inode *inode = mapping->host;
2939 int pages_written = 0;
2941 unsigned int max_pages;
2942 int range_cyclic, cycled = 1, io_done = 0;
2943 int needed_blocks, ret = 0;
2944 long desired_nr_to_write, nr_to_writebump = 0;
2945 loff_t range_start = wbc->range_start;
2946 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2947 pgoff_t done_index = 0;
2950 trace_ext4_da_writepages(inode, wbc);
2953 * No pages to write? This is mainly a kludge to avoid starting
2954 * a transaction for special inodes like journal inode on last iput()
2955 * because that could violate lock ordering on umount
2957 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2961 * If the filesystem has aborted, it is read-only, so return
2962 * right away instead of dumping stack traces later on that
2963 * will obscure the real source of the problem. We test
2964 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2965 * the latter could be true if the filesystem is mounted
2966 * read-only, and in that case, ext4_da_writepages should
2967 * *never* be called, so if that ever happens, we would want
2970 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
2973 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2976 range_cyclic = wbc->range_cyclic;
2977 if (wbc->range_cyclic) {
2978 index = mapping->writeback_index;
2981 wbc->range_start = index << PAGE_CACHE_SHIFT;
2982 wbc->range_end = LLONG_MAX;
2983 wbc->range_cyclic = 0;
2986 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2987 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2991 * This works around two forms of stupidity. The first is in
2992 * the writeback code, which caps the maximum number of pages
2993 * written to be 1024 pages. This is wrong on multiple
2994 * levels; different architectues have a different page size,
2995 * which changes the maximum amount of data which gets
2996 * written. Secondly, 4 megabytes is way too small. XFS
2997 * forces this value to be 16 megabytes by multiplying
2998 * nr_to_write parameter by four, and then relies on its
2999 * allocator to allocate larger extents to make them
3000 * contiguous. Unfortunately this brings us to the second
3001 * stupidity, which is that ext4's mballoc code only allocates
3002 * at most 2048 blocks. So we force contiguous writes up to
3003 * the number of dirty blocks in the inode, or
3004 * sbi->max_writeback_mb_bump whichever is smaller.
3006 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
3007 if (!range_cyclic && range_whole) {
3008 if (wbc->nr_to_write == LONG_MAX)
3009 desired_nr_to_write = wbc->nr_to_write;
3011 desired_nr_to_write = wbc->nr_to_write * 8;
3013 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
3015 if (desired_nr_to_write > max_pages)
3016 desired_nr_to_write = max_pages;
3018 if (wbc->nr_to_write < desired_nr_to_write) {
3019 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
3020 wbc->nr_to_write = desired_nr_to_write;
3024 mpd.inode = mapping->host;
3026 pages_skipped = wbc->pages_skipped;
3029 if (wbc->sync_mode == WB_SYNC_ALL)
3030 tag_pages_for_writeback(mapping, index, end);
3032 while (!ret && wbc->nr_to_write > 0) {
3035 * we insert one extent at a time. So we need
3036 * credit needed for single extent allocation.
3037 * journalled mode is currently not supported
3040 BUG_ON(ext4_should_journal_data(inode));
3041 needed_blocks = ext4_da_writepages_trans_blocks(inode);
3043 /* start a new transaction*/
3044 handle = ext4_journal_start(inode, needed_blocks);
3045 if (IS_ERR(handle)) {
3046 ret = PTR_ERR(handle);
3047 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
3048 "%ld pages, ino %lu; err %d", __func__,
3049 wbc->nr_to_write, inode->i_ino, ret);
3050 goto out_writepages;
3054 * Now call __mpage_da_writepage to find the next
3055 * contiguous region of logical blocks that need
3056 * blocks to be allocated by ext4. We don't actually
3057 * submit the blocks for I/O here, even though
3058 * write_cache_pages thinks it will, and will set the
3059 * pages as clean for write before calling
3060 * __mpage_da_writepage().
3068 mpd.pages_written = 0;
3070 ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index);
3072 * If we have a contiguous extent of pages and we
3073 * haven't done the I/O yet, map the blocks and submit
3076 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
3077 mpage_da_map_and_submit(&mpd);
3078 ret = MPAGE_DA_EXTENT_TAIL;
3080 trace_ext4_da_write_pages(inode, &mpd);
3081 wbc->nr_to_write -= mpd.pages_written;
3083 ext4_journal_stop(handle);
3085 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
3086 /* commit the transaction which would
3087 * free blocks released in the transaction
3090 jbd2_journal_force_commit_nested(sbi->s_journal);
3091 wbc->pages_skipped = pages_skipped;
3093 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
3095 * got one extent now try with
3098 pages_written += mpd.pages_written;
3099 wbc->pages_skipped = pages_skipped;
3102 } else if (wbc->nr_to_write)
3104 * There is no more writeout needed
3105 * or we requested for a noblocking writeout
3106 * and we found the device congested
3110 if (!io_done && !cycled) {
3113 wbc->range_start = index << PAGE_CACHE_SHIFT;
3114 wbc->range_end = mapping->writeback_index - 1;
3117 if (pages_skipped != wbc->pages_skipped)
3118 ext4_msg(inode->i_sb, KERN_CRIT,
3119 "This should not happen leaving %s "
3120 "with nr_to_write = %ld ret = %d",
3121 __func__, wbc->nr_to_write, ret);
3124 wbc->range_cyclic = range_cyclic;
3125 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
3127 * set the writeback_index so that range_cyclic
3128 * mode will write it back later
3130 mapping->writeback_index = done_index;
3133 wbc->nr_to_write -= nr_to_writebump;
3134 wbc->range_start = range_start;
3135 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
3139 #define FALL_BACK_TO_NONDELALLOC 1
3140 static int ext4_nonda_switch(struct super_block *sb)
3142 s64 free_blocks, dirty_blocks;
3143 struct ext4_sb_info *sbi = EXT4_SB(sb);
3146 * switch to non delalloc mode if we are running low
3147 * on free block. The free block accounting via percpu
3148 * counters can get slightly wrong with percpu_counter_batch getting
3149 * accumulated on each CPU without updating global counters
3150 * Delalloc need an accurate free block accounting. So switch
3151 * to non delalloc when we are near to error range.
3153 free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
3154 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter);
3155 if (2 * free_blocks < 3 * dirty_blocks ||
3156 free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) {
3158 * free block count is less than 150% of dirty blocks
3159 * or free blocks is less than watermark
3164 * Even if we don't switch but are nearing capacity,
3165 * start pushing delalloc when 1/2 of free blocks are dirty.
3167 if (free_blocks < 2 * dirty_blocks)
3168 writeback_inodes_sb_if_idle(sb);
3173 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
3174 loff_t pos, unsigned len, unsigned flags,
3175 struct page **pagep, void **fsdata)
3177 int ret, retries = 0;
3180 struct inode *inode = mapping->host;
3183 index = pos >> PAGE_CACHE_SHIFT;
3185 if (ext4_nonda_switch(inode->i_sb)) {
3186 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
3187 return ext4_write_begin(file, mapping, pos,
3188 len, flags, pagep, fsdata);
3190 *fsdata = (void *)0;
3191 trace_ext4_da_write_begin(inode, pos, len, flags);
3194 * With delayed allocation, we don't log the i_disksize update
3195 * if there is delayed block allocation. But we still need
3196 * to journalling the i_disksize update if writes to the end
3197 * of file which has an already mapped buffer.
3199 handle = ext4_journal_start(inode, 1);
3200 if (IS_ERR(handle)) {
3201 ret = PTR_ERR(handle);
3204 /* We cannot recurse into the filesystem as the transaction is already
3206 flags |= AOP_FLAG_NOFS;
3208 page = grab_cache_page_write_begin(mapping, index, flags);
3210 ext4_journal_stop(handle);
3216 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
3219 ext4_journal_stop(handle);
3220 page_cache_release(page);
3222 * block_write_begin may have instantiated a few blocks
3223 * outside i_size. Trim these off again. Don't need
3224 * i_size_read because we hold i_mutex.
3226 if (pos + len > inode->i_size)
3227 ext4_truncate_failed_write(inode);
3230 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
3237 * Check if we should update i_disksize
3238 * when write to the end of file but not require block allocation
3240 static int ext4_da_should_update_i_disksize(struct page *page,
3241 unsigned long offset)
3243 struct buffer_head *bh;
3244 struct inode *inode = page->mapping->host;
3248 bh = page_buffers(page);
3249 idx = offset >> inode->i_blkbits;
3251 for (i = 0; i < idx; i++)
3252 bh = bh->b_this_page;
3254 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
3259 static int ext4_da_write_end(struct file *file,
3260 struct address_space *mapping,
3261 loff_t pos, unsigned len, unsigned copied,
3262 struct page *page, void *fsdata)
3264 struct inode *inode = mapping->host;
3266 handle_t *handle = ext4_journal_current_handle();
3268 unsigned long start, end;
3269 int write_mode = (int)(unsigned long)fsdata;
3271 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
3272 if (ext4_should_order_data(inode)) {
3273 return ext4_ordered_write_end(file, mapping, pos,
3274 len, copied, page, fsdata);
3275 } else if (ext4_should_writeback_data(inode)) {
3276 return ext4_writeback_write_end(file, mapping, pos,
3277 len, copied, page, fsdata);
3283 trace_ext4_da_write_end(inode, pos, len, copied);
3284 start = pos & (PAGE_CACHE_SIZE - 1);
3285 end = start + copied - 1;
3288 * generic_write_end() will run mark_inode_dirty() if i_size
3289 * changes. So let's piggyback the i_disksize mark_inode_dirty
3293 new_i_size = pos + copied;
3294 if (new_i_size > EXT4_I(inode)->i_disksize) {
3295 if (ext4_da_should_update_i_disksize(page, end)) {
3296 down_write(&EXT4_I(inode)->i_data_sem);
3297 if (new_i_size > EXT4_I(inode)->i_disksize) {
3299 * Updating i_disksize when extending file
3300 * without needing block allocation
3302 if (ext4_should_order_data(inode))
3303 ret = ext4_jbd2_file_inode(handle,
3306 EXT4_I(inode)->i_disksize = new_i_size;
3308 up_write(&EXT4_I(inode)->i_data_sem);
3309 /* We need to mark inode dirty even if
3310 * new_i_size is less that inode->i_size
3311 * bu greater than i_disksize.(hint delalloc)
3313 ext4_mark_inode_dirty(handle, inode);
3316 ret2 = generic_write_end(file, mapping, pos, len, copied,
3321 ret2 = ext4_journal_stop(handle);
3325 return ret ? ret : copied;
3328 static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
3331 * Drop reserved blocks
3333 BUG_ON(!PageLocked(page));
3334 if (!page_has_buffers(page))
3337 ext4_da_page_release_reservation(page, offset);
3340 ext4_invalidatepage(page, offset);
3346 * Force all delayed allocation blocks to be allocated for a given inode.
3348 int ext4_alloc_da_blocks(struct inode *inode)
3350 trace_ext4_alloc_da_blocks(inode);
3352 if (!EXT4_I(inode)->i_reserved_data_blocks &&
3353 !EXT4_I(inode)->i_reserved_meta_blocks)
3357 * We do something simple for now. The filemap_flush() will
3358 * also start triggering a write of the data blocks, which is
3359 * not strictly speaking necessary (and for users of
3360 * laptop_mode, not even desirable). However, to do otherwise
3361 * would require replicating code paths in:
3363 * ext4_da_writepages() ->
3364 * write_cache_pages() ---> (via passed in callback function)
3365 * __mpage_da_writepage() -->
3366 * mpage_add_bh_to_extent()
3367 * mpage_da_map_blocks()
3369 * The problem is that write_cache_pages(), located in
3370 * mm/page-writeback.c, marks pages clean in preparation for
3371 * doing I/O, which is not desirable if we're not planning on
3374 * We could call write_cache_pages(), and then redirty all of
3375 * the pages by calling redirty_page_for_writeback() but that
3376 * would be ugly in the extreme. So instead we would need to
3377 * replicate parts of the code in the above functions,
3378 * simplifying them becuase we wouldn't actually intend to
3379 * write out the pages, but rather only collect contiguous
3380 * logical block extents, call the multi-block allocator, and
3381 * then update the buffer heads with the block allocations.
3383 * For now, though, we'll cheat by calling filemap_flush(),
3384 * which will map the blocks, and start the I/O, but not
3385 * actually wait for the I/O to complete.
3387 return filemap_flush(inode->i_mapping);
3391 * bmap() is special. It gets used by applications such as lilo and by
3392 * the swapper to find the on-disk block of a specific piece of data.
3394 * Naturally, this is dangerous if the block concerned is still in the
3395 * journal. If somebody makes a swapfile on an ext4 data-journaling
3396 * filesystem and enables swap, then they may get a nasty shock when the
3397 * data getting swapped to that swapfile suddenly gets overwritten by
3398 * the original zero's written out previously to the journal and
3399 * awaiting writeback in the kernel's buffer cache.
3401 * So, if we see any bmap calls here on a modified, data-journaled file,
3402 * take extra steps to flush any blocks which might be in the cache.
3404 static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
3406 struct inode *inode = mapping->host;
3410 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3411 test_opt(inode->i_sb, DELALLOC)) {
3413 * With delalloc we want to sync the file
3414 * so that we can make sure we allocate
3417 filemap_write_and_wait(mapping);
3420 if (EXT4_JOURNAL(inode) &&
3421 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
3423 * This is a REALLY heavyweight approach, but the use of
3424 * bmap on dirty files is expected to be extremely rare:
3425 * only if we run lilo or swapon on a freshly made file
3426 * do we expect this to happen.
3428 * (bmap requires CAP_SYS_RAWIO so this does not
3429 * represent an unprivileged user DOS attack --- we'd be
3430 * in trouble if mortal users could trigger this path at
3433 * NB. EXT4_STATE_JDATA is not set on files other than
3434 * regular files. If somebody wants to bmap a directory
3435 * or symlink and gets confused because the buffer
3436 * hasn't yet been flushed to disk, they deserve
3437 * everything they get.
3440 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
3441 journal = EXT4_JOURNAL(inode);
3442 jbd2_journal_lock_updates(journal);
3443 err = jbd2_journal_flush(journal);
3444 jbd2_journal_unlock_updates(journal);
3450 return generic_block_bmap(mapping, block, ext4_get_block);
3453 static int ext4_readpage(struct file *file, struct page *page)
3455 return mpage_readpage(page, ext4_get_block);
3459 ext4_readpages(struct file *file, struct address_space *mapping,
3460 struct list_head *pages, unsigned nr_pages)
3462 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
3465 static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset)
3467 struct buffer_head *head, *bh;
3468 unsigned int curr_off = 0;
3470 if (!page_has_buffers(page))
3472 head = bh = page_buffers(page);
3474 if (offset <= curr_off && test_clear_buffer_uninit(bh)
3476 ext4_free_io_end(bh->b_private);
3477 bh->b_private = NULL;
3478 bh->b_end_io = NULL;
3480 curr_off = curr_off + bh->b_size;
3481 bh = bh->b_this_page;
3482 } while (bh != head);
3485 static void ext4_invalidatepage(struct page *page, unsigned long offset)
3487 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3490 * free any io_end structure allocated for buffers to be discarded
3492 if (ext4_should_dioread_nolock(page->mapping->host))
3493 ext4_invalidatepage_free_endio(page, offset);
3495 * If it's a full truncate we just forget about the pending dirtying
3498 ClearPageChecked(page);
3501 jbd2_journal_invalidatepage(journal, page, offset);
3503 block_invalidatepage(page, offset);
3506 static int ext4_releasepage(struct page *page, gfp_t wait)
3508 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3510 WARN_ON(PageChecked(page));
3511 if (!page_has_buffers(page))
3514 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3516 return try_to_free_buffers(page);
3520 * O_DIRECT for ext3 (or indirect map) based files
3522 * If the O_DIRECT write will extend the file then add this inode to the
3523 * orphan list. So recovery will truncate it back to the original size
3524 * if the machine crashes during the write.
3526 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3527 * crashes then stale disk data _may_ be exposed inside the file. But current
3528 * VFS code falls back into buffered path in that case so we are safe.
3530 static ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
3531 const struct iovec *iov, loff_t offset,
3532 unsigned long nr_segs)
3534 struct file *file = iocb->ki_filp;
3535 struct inode *inode = file->f_mapping->host;
3536 struct ext4_inode_info *ei = EXT4_I(inode);
3540 size_t count = iov_length(iov, nr_segs);
3544 loff_t final_size = offset + count;
3546 if (final_size > inode->i_size) {
3547 /* Credits for sb + inode write */
3548 handle = ext4_journal_start(inode, 2);
3549 if (IS_ERR(handle)) {
3550 ret = PTR_ERR(handle);
3553 ret = ext4_orphan_add(handle, inode);
3555 ext4_journal_stop(handle);
3559 ei->i_disksize = inode->i_size;
3560 ext4_journal_stop(handle);
3565 if (rw == READ && ext4_should_dioread_nolock(inode))
3566 ret = __blockdev_direct_IO(rw, iocb, inode,
3567 inode->i_sb->s_bdev, iov,
3569 ext4_get_block, NULL, NULL, 0);
3571 ret = blockdev_direct_IO(rw, iocb, inode,
3572 inode->i_sb->s_bdev, iov,
3574 ext4_get_block, NULL);
3576 if (unlikely((rw & WRITE) && ret < 0)) {
3577 loff_t isize = i_size_read(inode);
3578 loff_t end = offset + iov_length(iov, nr_segs);
3581 vmtruncate(inode, isize);
3584 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
3590 /* Credits for sb + inode write */
3591 handle = ext4_journal_start(inode, 2);
3592 if (IS_ERR(handle)) {
3593 /* This is really bad luck. We've written the data
3594 * but cannot extend i_size. Bail out and pretend
3595 * the write failed... */
3596 ret = PTR_ERR(handle);
3598 ext4_orphan_del(NULL, inode);
3603 ext4_orphan_del(handle, inode);
3605 loff_t end = offset + ret;
3606 if (end > inode->i_size) {
3607 ei->i_disksize = end;
3608 i_size_write(inode, end);
3610 * We're going to return a positive `ret'
3611 * here due to non-zero-length I/O, so there's
3612 * no way of reporting error returns from
3613 * ext4_mark_inode_dirty() to userspace. So
3616 ext4_mark_inode_dirty(handle, inode);
3619 err = ext4_journal_stop(handle);
3628 * ext4_get_block used when preparing for a DIO write or buffer write.
3629 * We allocate an uinitialized extent if blocks haven't been allocated.
3630 * The extent will be converted to initialized after the IO is complete.
3632 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
3633 struct buffer_head *bh_result, int create)
3635 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
3636 inode->i_ino, create);
3637 return _ext4_get_block(inode, iblock, bh_result,
3638 EXT4_GET_BLOCKS_IO_CREATE_EXT);
3641 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
3642 ssize_t size, void *private, int ret,
3645 ext4_io_end_t *io_end = iocb->private;
3646 struct workqueue_struct *wq;
3647 unsigned long flags;
3648 struct ext4_inode_info *ei;
3650 /* if not async direct IO or dio with 0 bytes write, just return */
3651 if (!io_end || !size)
3654 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3655 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3656 iocb->private, io_end->inode->i_ino, iocb, offset,
3659 /* if not aio dio with unwritten extents, just free io and return */
3660 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
3661 ext4_free_io_end(io_end);
3662 iocb->private = NULL;
3665 aio_complete(iocb, ret, 0);
3669 io_end->offset = offset;
3670 io_end->size = size;
3672 io_end->iocb = iocb;
3673 io_end->result = ret;
3675 wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
3677 /* Add the io_end to per-inode completed aio dio list*/
3678 ei = EXT4_I(io_end->inode);
3679 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
3680 list_add_tail(&io_end->list, &ei->i_completed_io_list);
3681 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
3683 /* queue the work to convert unwritten extents to written */
3684 queue_work(wq, &io_end->work);
3685 iocb->private = NULL;
3688 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
3690 ext4_io_end_t *io_end = bh->b_private;
3691 struct workqueue_struct *wq;
3692 struct inode *inode;
3693 unsigned long flags;
3695 if (!test_clear_buffer_uninit(bh) || !io_end)
3698 if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
3699 printk("sb umounted, discard end_io request for inode %lu\n",
3700 io_end->inode->i_ino);
3701 ext4_free_io_end(io_end);
3705 io_end->flag = EXT4_IO_END_UNWRITTEN;
3706 inode = io_end->inode;
3708 /* Add the io_end to per-inode completed io list*/
3709 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
3710 list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
3711 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
3713 wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
3714 /* queue the work to convert unwritten extents to written */
3715 queue_work(wq, &io_end->work);
3717 bh->b_private = NULL;
3718 bh->b_end_io = NULL;
3719 clear_buffer_uninit(bh);
3720 end_buffer_async_write(bh, uptodate);
3723 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
3725 ext4_io_end_t *io_end;
3726 struct page *page = bh->b_page;
3727 loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
3728 size_t size = bh->b_size;
3731 io_end = ext4_init_io_end(inode, GFP_ATOMIC);
3733 pr_warning_ratelimited("%s: allocation fail\n", __func__);
3737 io_end->offset = offset;
3738 io_end->size = size;
3740 * We need to hold a reference to the page to make sure it
3741 * doesn't get evicted before ext4_end_io_work() has a chance
3742 * to convert the extent from written to unwritten.
3744 io_end->page = page;
3745 get_page(io_end->page);
3747 bh->b_private = io_end;
3748 bh->b_end_io = ext4_end_io_buffer_write;
3753 * For ext4 extent files, ext4 will do direct-io write to holes,
3754 * preallocated extents, and those write extend the file, no need to
3755 * fall back to buffered IO.
3757 * For holes, we fallocate those blocks, mark them as unintialized
3758 * If those blocks were preallocated, we mark sure they are splited, but
3759 * still keep the range to write as unintialized.
3761 * The unwrritten extents will be converted to written when DIO is completed.
3762 * For async direct IO, since the IO may still pending when return, we
3763 * set up an end_io call back function, which will do the convertion
3764 * when async direct IO completed.
3766 * If the O_DIRECT write will extend the file then add this inode to the
3767 * orphan list. So recovery will truncate it back to the original size
3768 * if the machine crashes during the write.
3771 static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
3772 const struct iovec *iov, loff_t offset,
3773 unsigned long nr_segs)
3775 struct file *file = iocb->ki_filp;
3776 struct inode *inode = file->f_mapping->host;
3778 size_t count = iov_length(iov, nr_segs);
3780 loff_t final_size = offset + count;
3781 if (rw == WRITE && final_size <= inode->i_size) {
3783 * We could direct write to holes and fallocate.
3785 * Allocated blocks to fill the hole are marked as uninitialized
3786 * to prevent paralel buffered read to expose the stale data
3787 * before DIO complete the data IO.
3789 * As to previously fallocated extents, ext4 get_block
3790 * will just simply mark the buffer mapped but still
3791 * keep the extents uninitialized.
3793 * for non AIO case, we will convert those unwritten extents
3794 * to written after return back from blockdev_direct_IO.
3796 * for async DIO, the conversion needs to be defered when
3797 * the IO is completed. The ext4 end_io callback function
3798 * will be called to take care of the conversion work.
3799 * Here for async case, we allocate an io_end structure to
3802 iocb->private = NULL;
3803 EXT4_I(inode)->cur_aio_dio = NULL;
3804 if (!is_sync_kiocb(iocb)) {
3805 iocb->private = ext4_init_io_end(inode, GFP_NOFS);
3809 * we save the io structure for current async
3810 * direct IO, so that later ext4_map_blocks()
3811 * could flag the io structure whether there
3812 * is a unwritten extents needs to be converted
3813 * when IO is completed.
3815 EXT4_I(inode)->cur_aio_dio = iocb->private;
3818 ret = blockdev_direct_IO(rw, iocb, inode,
3819 inode->i_sb->s_bdev, iov,
3821 ext4_get_block_write,
3824 EXT4_I(inode)->cur_aio_dio = NULL;
3826 * The io_end structure takes a reference to the inode,
3827 * that structure needs to be destroyed and the
3828 * reference to the inode need to be dropped, when IO is
3829 * complete, even with 0 byte write, or failed.
3831 * In the successful AIO DIO case, the io_end structure will be
3832 * desctroyed and the reference to the inode will be dropped
3833 * after the end_io call back function is called.
3835 * In the case there is 0 byte write, or error case, since
3836 * VFS direct IO won't invoke the end_io call back function,
3837 * we need to free the end_io structure here.
3839 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
3840 ext4_free_io_end(iocb->private);
3841 iocb->private = NULL;
3842 } else if (ret > 0 && ext4_test_inode_state(inode,
3843 EXT4_STATE_DIO_UNWRITTEN)) {
3846 * for non AIO case, since the IO is already
3847 * completed, we could do the convertion right here
3849 err = ext4_convert_unwritten_extents(inode,
3853 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3858 /* for write the the end of file case, we fall back to old way */
3859 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3862 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3863 const struct iovec *iov, loff_t offset,
3864 unsigned long nr_segs)
3866 struct file *file = iocb->ki_filp;
3867 struct inode *inode = file->f_mapping->host;
3869 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3870 return ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3872 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3876 * Pages can be marked dirty completely asynchronously from ext4's journalling
3877 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3878 * much here because ->set_page_dirty is called under VFS locks. The page is
3879 * not necessarily locked.
3881 * We cannot just dirty the page and leave attached buffers clean, because the
3882 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3883 * or jbddirty because all the journalling code will explode.
3885 * So what we do is to mark the page "pending dirty" and next time writepage
3886 * is called, propagate that into the buffers appropriately.
3888 static int ext4_journalled_set_page_dirty(struct page *page)
3890 SetPageChecked(page);
3891 return __set_page_dirty_nobuffers(page);
3894 static const struct address_space_operations ext4_ordered_aops = {
3895 .readpage = ext4_readpage,
3896 .readpages = ext4_readpages,
3897 .writepage = ext4_writepage,
3898 .sync_page = block_sync_page,
3899 .write_begin = ext4_write_begin,
3900 .write_end = ext4_ordered_write_end,
3902 .invalidatepage = ext4_invalidatepage,
3903 .releasepage = ext4_releasepage,
3904 .direct_IO = ext4_direct_IO,
3905 .migratepage = buffer_migrate_page,
3906 .is_partially_uptodate = block_is_partially_uptodate,
3907 .error_remove_page = generic_error_remove_page,
3910 static const struct address_space_operations ext4_writeback_aops = {
3911 .readpage = ext4_readpage,
3912 .readpages = ext4_readpages,
3913 .writepage = ext4_writepage,
3914 .sync_page = block_sync_page,
3915 .write_begin = ext4_write_begin,
3916 .write_end = ext4_writeback_write_end,
3918 .invalidatepage = ext4_invalidatepage,
3919 .releasepage = ext4_releasepage,
3920 .direct_IO = ext4_direct_IO,
3921 .migratepage = buffer_migrate_page,
3922 .is_partially_uptodate = block_is_partially_uptodate,
3923 .error_remove_page = generic_error_remove_page,
3926 static const struct address_space_operations ext4_journalled_aops = {
3927 .readpage = ext4_readpage,
3928 .readpages = ext4_readpages,
3929 .writepage = ext4_writepage,
3930 .sync_page = block_sync_page,
3931 .write_begin = ext4_write_begin,
3932 .write_end = ext4_journalled_write_end,
3933 .set_page_dirty = ext4_journalled_set_page_dirty,
3935 .invalidatepage = ext4_invalidatepage,
3936 .releasepage = ext4_releasepage,
3937 .is_partially_uptodate = block_is_partially_uptodate,
3938 .error_remove_page = generic_error_remove_page,
3941 static const struct address_space_operations ext4_da_aops = {
3942 .readpage = ext4_readpage,
3943 .readpages = ext4_readpages,
3944 .writepage = ext4_writepage,
3945 .writepages = ext4_da_writepages,
3946 .sync_page = block_sync_page,
3947 .write_begin = ext4_da_write_begin,
3948 .write_end = ext4_da_write_end,
3950 .invalidatepage = ext4_da_invalidatepage,
3951 .releasepage = ext4_releasepage,
3952 .direct_IO = ext4_direct_IO,
3953 .migratepage = buffer_migrate_page,
3954 .is_partially_uptodate = block_is_partially_uptodate,
3955 .error_remove_page = generic_error_remove_page,
3958 void ext4_set_aops(struct inode *inode)
3960 if (ext4_should_order_data(inode) &&
3961 test_opt(inode->i_sb, DELALLOC))
3962 inode->i_mapping->a_ops = &ext4_da_aops;
3963 else if (ext4_should_order_data(inode))
3964 inode->i_mapping->a_ops = &ext4_ordered_aops;
3965 else if (ext4_should_writeback_data(inode) &&
3966 test_opt(inode->i_sb, DELALLOC))
3967 inode->i_mapping->a_ops = &ext4_da_aops;
3968 else if (ext4_should_writeback_data(inode))
3969 inode->i_mapping->a_ops = &ext4_writeback_aops;
3971 inode->i_mapping->a_ops = &ext4_journalled_aops;
3975 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3976 * up to the end of the block which corresponds to `from'.
3977 * This required during truncate. We need to physically zero the tail end
3978 * of that block so it doesn't yield old data if the file is later grown.
3980 int ext4_block_truncate_page(handle_t *handle,
3981 struct address_space *mapping, loff_t from)
3983 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
3984 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3985 unsigned blocksize, length, pos;
3987 struct inode *inode = mapping->host;
3988 struct buffer_head *bh;
3992 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3993 mapping_gfp_mask(mapping) & ~__GFP_FS);
3997 blocksize = inode->i_sb->s_blocksize;
3998 length = blocksize - (offset & (blocksize - 1));
3999 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
4001 if (!page_has_buffers(page))
4002 create_empty_buffers(page, blocksize, 0);
4004 /* Find the buffer that contains "offset" */
4005 bh = page_buffers(page);
4007 while (offset >= pos) {
4008 bh = bh->b_this_page;
4014 if (buffer_freed(bh)) {
4015 BUFFER_TRACE(bh, "freed: skip");
4019 if (!buffer_mapped(bh)) {
4020 BUFFER_TRACE(bh, "unmapped");
4021 ext4_get_block(inode, iblock, bh, 0);
4022 /* unmapped? It's a hole - nothing to do */
4023 if (!buffer_mapped(bh)) {
4024 BUFFER_TRACE(bh, "still unmapped");
4029 /* Ok, it's mapped. Make sure it's up-to-date */
4030 if (PageUptodate(page))
4031 set_buffer_uptodate(bh);
4033 if (!buffer_uptodate(bh)) {
4035 ll_rw_block(READ, 1, &bh);
4037 /* Uhhuh. Read error. Complain and punt. */
4038 if (!buffer_uptodate(bh))
4042 if (ext4_should_journal_data(inode)) {
4043 BUFFER_TRACE(bh, "get write access");
4044 err = ext4_journal_get_write_access(handle, bh);
4049 zero_user(page, offset, length);
4051 BUFFER_TRACE(bh, "zeroed end of block");
4054 if (ext4_should_journal_data(inode)) {
4055 err = ext4_handle_dirty_metadata(handle, inode, bh);
4057 if (ext4_should_order_data(inode))
4058 err = ext4_jbd2_file_inode(handle, inode);
4059 mark_buffer_dirty(bh);
4064 page_cache_release(page);
4069 * Probably it should be a library function... search for first non-zero word
4070 * or memcmp with zero_page, whatever is better for particular architecture.
4073 static inline int all_zeroes(__le32 *p, __le32 *q)
4082 * ext4_find_shared - find the indirect blocks for partial truncation.
4083 * @inode: inode in question
4084 * @depth: depth of the affected branch
4085 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4086 * @chain: place to store the pointers to partial indirect blocks
4087 * @top: place to the (detached) top of branch
4089 * This is a helper function used by ext4_truncate().
4091 * When we do truncate() we may have to clean the ends of several
4092 * indirect blocks but leave the blocks themselves alive. Block is
4093 * partially truncated if some data below the new i_size is refered
4094 * from it (and it is on the path to the first completely truncated
4095 * data block, indeed). We have to free the top of that path along
4096 * with everything to the right of the path. Since no allocation
4097 * past the truncation point is possible until ext4_truncate()
4098 * finishes, we may safely do the latter, but top of branch may
4099 * require special attention - pageout below the truncation point
4100 * might try to populate it.
4102 * We atomically detach the top of branch from the tree, store the
4103 * block number of its root in *@top, pointers to buffer_heads of
4104 * partially truncated blocks - in @chain[].bh and pointers to
4105 * their last elements that should not be removed - in
4106 * @chain[].p. Return value is the pointer to last filled element
4109 * The work left to caller to do the actual freeing of subtrees:
4110 * a) free the subtree starting from *@top
4111 * b) free the subtrees whose roots are stored in
4112 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4113 * c) free the subtrees growing from the inode past the @chain[0].
4114 * (no partially truncated stuff there). */
4116 static Indirect *ext4_find_shared(struct inode *inode, int depth,
4117 ext4_lblk_t offsets[4], Indirect chain[4],
4120 Indirect *partial, *p;
4124 /* Make k index the deepest non-null offset + 1 */
4125 for (k = depth; k > 1 && !offsets[k-1]; k--)
4127 partial = ext4_get_branch(inode, k, offsets, chain, &err);
4128 /* Writer: pointers */
4130 partial = chain + k-1;
4132 * If the branch acquired continuation since we've looked at it -
4133 * fine, it should all survive and (new) top doesn't belong to us.
4135 if (!partial->key && *partial->p)
4138 for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
4141 * OK, we've found the last block that must survive. The rest of our
4142 * branch should be detached before unlocking. However, if that rest
4143 * of branch is all ours and does not grow immediately from the inode
4144 * it's easier to cheat and just decrement partial->p.
4146 if (p == chain + k - 1 && p > chain) {
4150 /* Nope, don't do this in ext4. Must leave the tree intact */
4157 while (partial > p) {
4158 brelse(partial->bh);
4166 * Zero a number of block pointers in either an inode or an indirect block.
4167 * If we restart the transaction we must again get write access to the
4168 * indirect block for further modification.
4170 * We release `count' blocks on disk, but (last - first) may be greater
4171 * than `count' because there can be holes in there.
4173 static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
4174 struct buffer_head *bh,
4175 ext4_fsblk_t block_to_free,
4176 unsigned long count, __le32 *first,
4180 int flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED;
4182 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
4183 flags |= EXT4_FREE_BLOCKS_METADATA;
4185 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free,
4187 EXT4_ERROR_INODE(inode, "attempt to clear invalid "
4188 "blocks %llu len %lu",
4189 (unsigned long long) block_to_free, count);
4193 if (try_to_extend_transaction(handle, inode)) {
4195 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4196 ext4_handle_dirty_metadata(handle, inode, bh);
4198 ext4_mark_inode_dirty(handle, inode);
4199 ext4_truncate_restart_trans(handle, inode,
4200 blocks_for_truncate(inode));
4202 BUFFER_TRACE(bh, "retaking write access");
4203 ext4_journal_get_write_access(handle, bh);
4207 for (p = first; p < last; p++)
4210 ext4_free_blocks(handle, inode, 0, block_to_free, count, flags);
4215 * ext4_free_data - free a list of data blocks
4216 * @handle: handle for this transaction
4217 * @inode: inode we are dealing with
4218 * @this_bh: indirect buffer_head which contains *@first and *@last
4219 * @first: array of block numbers
4220 * @last: points immediately past the end of array
4222 * We are freeing all blocks refered from that array (numbers are stored as
4223 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4225 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4226 * blocks are contiguous then releasing them at one time will only affect one
4227 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4228 * actually use a lot of journal space.
4230 * @this_bh will be %NULL if @first and @last point into the inode's direct
4233 static void ext4_free_data(handle_t *handle, struct inode *inode,
4234 struct buffer_head *this_bh,
4235 __le32 *first, __le32 *last)
4237 ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */
4238 unsigned long count = 0; /* Number of blocks in the run */
4239 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
4242 ext4_fsblk_t nr; /* Current block # */
4243 __le32 *p; /* Pointer into inode/ind
4244 for current block */
4247 if (this_bh) { /* For indirect block */
4248 BUFFER_TRACE(this_bh, "get_write_access");
4249 err = ext4_journal_get_write_access(handle, this_bh);
4250 /* Important: if we can't update the indirect pointers
4251 * to the blocks, we can't free them. */
4256 for (p = first; p < last; p++) {
4257 nr = le32_to_cpu(*p);
4259 /* accumulate blocks to free if they're contiguous */
4262 block_to_free_p = p;
4264 } else if (nr == block_to_free + count) {
4267 if (ext4_clear_blocks(handle, inode, this_bh,
4268 block_to_free, count,
4269 block_to_free_p, p))
4272 block_to_free_p = p;
4279 ext4_clear_blocks(handle, inode, this_bh, block_to_free,
4280 count, block_to_free_p, p);
4283 BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
4286 * The buffer head should have an attached journal head at this
4287 * point. However, if the data is corrupted and an indirect
4288 * block pointed to itself, it would have been detached when
4289 * the block was cleared. Check for this instead of OOPSing.
4291 if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
4292 ext4_handle_dirty_metadata(handle, inode, this_bh);
4294 EXT4_ERROR_INODE(inode,
4295 "circular indirect block detected at "
4297 (unsigned long long) this_bh->b_blocknr);
4302 * ext4_free_branches - free an array of branches
4303 * @handle: JBD handle for this transaction
4304 * @inode: inode we are dealing with
4305 * @parent_bh: the buffer_head which contains *@first and *@last
4306 * @first: array of block numbers
4307 * @last: pointer immediately past the end of array
4308 * @depth: depth of the branches to free
4310 * We are freeing all blocks refered from these branches (numbers are
4311 * stored as little-endian 32-bit) and updating @inode->i_blocks
4314 static void ext4_free_branches(handle_t *handle, struct inode *inode,
4315 struct buffer_head *parent_bh,
4316 __le32 *first, __le32 *last, int depth)
4321 if (ext4_handle_is_aborted(handle))
4325 struct buffer_head *bh;
4326 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
4328 while (--p >= first) {
4329 nr = le32_to_cpu(*p);
4331 continue; /* A hole */
4333 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb),
4335 EXT4_ERROR_INODE(inode,
4336 "invalid indirect mapped "
4337 "block %lu (level %d)",
4338 (unsigned long) nr, depth);
4342 /* Go read the buffer for the next level down */
4343 bh = sb_bread(inode->i_sb, nr);
4346 * A read failure? Report error and clear slot
4350 EXT4_ERROR_INODE_BLOCK(inode, nr,
4355 /* This zaps the entire block. Bottom up. */
4356 BUFFER_TRACE(bh, "free child branches");
4357 ext4_free_branches(handle, inode, bh,
4358 (__le32 *) bh->b_data,
4359 (__le32 *) bh->b_data + addr_per_block,
4363 * Everything below this this pointer has been
4364 * released. Now let this top-of-subtree go.
4366 * We want the freeing of this indirect block to be
4367 * atomic in the journal with the updating of the
4368 * bitmap block which owns it. So make some room in
4371 * We zero the parent pointer *after* freeing its
4372 * pointee in the bitmaps, so if extend_transaction()
4373 * for some reason fails to put the bitmap changes and
4374 * the release into the same transaction, recovery
4375 * will merely complain about releasing a free block,
4376 * rather than leaking blocks.
4378 if (ext4_handle_is_aborted(handle))
4380 if (try_to_extend_transaction(handle, inode)) {
4381 ext4_mark_inode_dirty(handle, inode);
4382 ext4_truncate_restart_trans(handle, inode,
4383 blocks_for_truncate(inode));
4387 * The forget flag here is critical because if
4388 * we are journaling (and not doing data
4389 * journaling), we have to make sure a revoke
4390 * record is written to prevent the journal
4391 * replay from overwriting the (former)
4392 * indirect block if it gets reallocated as a
4393 * data block. This must happen in the same
4394 * transaction where the data blocks are
4397 ext4_free_blocks(handle, inode, 0, nr, 1,
4398 EXT4_FREE_BLOCKS_METADATA|
4399 EXT4_FREE_BLOCKS_FORGET);
4403 * The block which we have just freed is
4404 * pointed to by an indirect block: journal it
4406 BUFFER_TRACE(parent_bh, "get_write_access");
4407 if (!ext4_journal_get_write_access(handle,
4410 BUFFER_TRACE(parent_bh,
4411 "call ext4_handle_dirty_metadata");
4412 ext4_handle_dirty_metadata(handle,
4419 /* We have reached the bottom of the tree. */
4420 BUFFER_TRACE(parent_bh, "free data blocks");
4421 ext4_free_data(handle, inode, parent_bh, first, last);
4425 int ext4_can_truncate(struct inode *inode)
4427 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4429 if (S_ISREG(inode->i_mode))
4431 if (S_ISDIR(inode->i_mode))
4433 if (S_ISLNK(inode->i_mode))
4434 return !ext4_inode_is_fast_symlink(inode);
4441 * We block out ext4_get_block() block instantiations across the entire
4442 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4443 * simultaneously on behalf of the same inode.
4445 * As we work through the truncate and commmit bits of it to the journal there
4446 * is one core, guiding principle: the file's tree must always be consistent on
4447 * disk. We must be able to restart the truncate after a crash.
4449 * The file's tree may be transiently inconsistent in memory (although it
4450 * probably isn't), but whenever we close off and commit a journal transaction,
4451 * the contents of (the filesystem + the journal) must be consistent and
4452 * restartable. It's pretty simple, really: bottom up, right to left (although
4453 * left-to-right works OK too).
4455 * Note that at recovery time, journal replay occurs *before* the restart of
4456 * truncate against the orphan inode list.
4458 * The committed inode has the new, desired i_size (which is the same as
4459 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4460 * that this inode's truncate did not complete and it will again call
4461 * ext4_truncate() to have another go. So there will be instantiated blocks
4462 * to the right of the truncation point in a crashed ext4 filesystem. But
4463 * that's fine - as long as they are linked from the inode, the post-crash
4464 * ext4_truncate() run will find them and release them.
4466 void ext4_truncate(struct inode *inode)
4469 struct ext4_inode_info *ei = EXT4_I(inode);
4470 __le32 *i_data = ei->i_data;
4471 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
4472 struct address_space *mapping = inode->i_mapping;
4473 ext4_lblk_t offsets[4];
4478 ext4_lblk_t last_block;
4479 unsigned blocksize = inode->i_sb->s_blocksize;
4481 if (!ext4_can_truncate(inode))
4484 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4486 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
4487 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
4489 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
4490 ext4_ext_truncate(inode);
4494 handle = start_transaction(inode);
4496 return; /* AKPM: return what? */
4498 last_block = (inode->i_size + blocksize-1)
4499 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
4501 if (inode->i_size & (blocksize - 1))
4502 if (ext4_block_truncate_page(handle, mapping, inode->i_size))
4505 n = ext4_block_to_path(inode, last_block, offsets, NULL);
4507 goto out_stop; /* error */
4510 * OK. This truncate is going to happen. We add the inode to the
4511 * orphan list, so that if this truncate spans multiple transactions,
4512 * and we crash, we will resume the truncate when the filesystem
4513 * recovers. It also marks the inode dirty, to catch the new size.
4515 * Implication: the file must always be in a sane, consistent
4516 * truncatable state while each transaction commits.
4518 if (ext4_orphan_add(handle, inode))
4522 * From here we block out all ext4_get_block() callers who want to
4523 * modify the block allocation tree.
4525 down_write(&ei->i_data_sem);
4527 ext4_discard_preallocations(inode);
4530 * The orphan list entry will now protect us from any crash which
4531 * occurs before the truncate completes, so it is now safe to propagate
4532 * the new, shorter inode size (held for now in i_size) into the
4533 * on-disk inode. We do this via i_disksize, which is the value which
4534 * ext4 *really* writes onto the disk inode.
4536 ei->i_disksize = inode->i_size;
4538 if (n == 1) { /* direct blocks */
4539 ext4_free_data(handle, inode, NULL, i_data+offsets[0],
4540 i_data + EXT4_NDIR_BLOCKS);
4544 partial = ext4_find_shared(inode, n, offsets, chain, &nr);
4545 /* Kill the top of shared branch (not detached) */
4547 if (partial == chain) {
4548 /* Shared branch grows from the inode */
4549 ext4_free_branches(handle, inode, NULL,
4550 &nr, &nr+1, (chain+n-1) - partial);
4553 * We mark the inode dirty prior to restart,
4554 * and prior to stop. No need for it here.
4557 /* Shared branch grows from an indirect block */
4558 BUFFER_TRACE(partial->bh, "get_write_access");
4559 ext4_free_branches(handle, inode, partial->bh,
4561 partial->p+1, (chain+n-1) - partial);
4564 /* Clear the ends of indirect blocks on the shared branch */
4565 while (partial > chain) {
4566 ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
4567 (__le32*)partial->bh->b_data+addr_per_block,
4568 (chain+n-1) - partial);
4569 BUFFER_TRACE(partial->bh, "call brelse");
4570 brelse(partial->bh);
4574 /* Kill the remaining (whole) subtrees */
4575 switch (offsets[0]) {
4577 nr = i_data[EXT4_IND_BLOCK];
4579 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
4580 i_data[EXT4_IND_BLOCK] = 0;
4582 case EXT4_IND_BLOCK:
4583 nr = i_data[EXT4_DIND_BLOCK];
4585 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
4586 i_data[EXT4_DIND_BLOCK] = 0;
4588 case EXT4_DIND_BLOCK:
4589 nr = i_data[EXT4_TIND_BLOCK];
4591 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
4592 i_data[EXT4_TIND_BLOCK] = 0;
4594 case EXT4_TIND_BLOCK:
4598 up_write(&ei->i_data_sem);
4599 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4600 ext4_mark_inode_dirty(handle, inode);
4603 * In a multi-transaction truncate, we only make the final transaction
4607 ext4_handle_sync(handle);
4610 * If this was a simple ftruncate(), and the file will remain alive
4611 * then we need to clear up the orphan record which we created above.
4612 * However, if this was a real unlink then we were called by
4613 * ext4_delete_inode(), and we allow that function to clean up the
4614 * orphan info for us.
4617 ext4_orphan_del(handle, inode);
4619 ext4_journal_stop(handle);
4623 * ext4_get_inode_loc returns with an extra refcount against the inode's
4624 * underlying buffer_head on success. If 'in_mem' is true, we have all
4625 * data in memory that is needed to recreate the on-disk version of this
4628 static int __ext4_get_inode_loc(struct inode *inode,
4629 struct ext4_iloc *iloc, int in_mem)
4631 struct ext4_group_desc *gdp;
4632 struct buffer_head *bh;
4633 struct super_block *sb = inode->i_sb;
4635 int inodes_per_block, inode_offset;
4638 if (!ext4_valid_inum(sb, inode->i_ino))
4641 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
4642 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
4647 * Figure out the offset within the block group inode table
4649 inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb));
4650 inode_offset = ((inode->i_ino - 1) %
4651 EXT4_INODES_PER_GROUP(sb));
4652 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
4653 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
4655 bh = sb_getblk(sb, block);
4657 EXT4_ERROR_INODE_BLOCK(inode, block,
4658 "unable to read itable block");
4661 if (!buffer_uptodate(bh)) {
4665 * If the buffer has the write error flag, we have failed
4666 * to write out another inode in the same block. In this
4667 * case, we don't have to read the block because we may
4668 * read the old inode data successfully.
4670 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
4671 set_buffer_uptodate(bh);
4673 if (buffer_uptodate(bh)) {
4674 /* someone brought it uptodate while we waited */
4680 * If we have all information of the inode in memory and this
4681 * is the only valid inode in the block, we need not read the
4685 struct buffer_head *bitmap_bh;
4688 start = inode_offset & ~(inodes_per_block - 1);
4690 /* Is the inode bitmap in cache? */
4691 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
4696 * If the inode bitmap isn't in cache then the
4697 * optimisation may end up performing two reads instead
4698 * of one, so skip it.
4700 if (!buffer_uptodate(bitmap_bh)) {
4704 for (i = start; i < start + inodes_per_block; i++) {
4705 if (i == inode_offset)
4707 if (ext4_test_bit(i, bitmap_bh->b_data))
4711 if (i == start + inodes_per_block) {
4712 /* all other inodes are free, so skip I/O */
4713 memset(bh->b_data, 0, bh->b_size);
4714 set_buffer_uptodate(bh);
4722 * If we need to do any I/O, try to pre-readahead extra
4723 * blocks from the inode table.
4725 if (EXT4_SB(sb)->s_inode_readahead_blks) {
4726 ext4_fsblk_t b, end, table;
4729 table = ext4_inode_table(sb, gdp);
4730 /* s_inode_readahead_blks is always a power of 2 */
4731 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
4734 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
4735 num = EXT4_INODES_PER_GROUP(sb);
4736 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4737 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
4738 num -= ext4_itable_unused_count(sb, gdp);
4739 table += num / inodes_per_block;
4743 sb_breadahead(sb, b++);
4747 * There are other valid inodes in the buffer, this inode
4748 * has in-inode xattrs, or we don't have this inode in memory.
4749 * Read the block from disk.
4752 bh->b_end_io = end_buffer_read_sync;
4753 submit_bh(READ_META, bh);
4755 if (!buffer_uptodate(bh)) {
4756 EXT4_ERROR_INODE_BLOCK(inode, block,
4757 "unable to read itable block");
4767 int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
4769 /* We have all inode data except xattrs in memory here. */
4770 return __ext4_get_inode_loc(inode, iloc,
4771 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
4774 void ext4_set_inode_flags(struct inode *inode)
4776 unsigned int flags = EXT4_I(inode)->i_flags;
4778 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
4779 if (flags & EXT4_SYNC_FL)
4780 inode->i_flags |= S_SYNC;
4781 if (flags & EXT4_APPEND_FL)
4782 inode->i_flags |= S_APPEND;
4783 if (flags & EXT4_IMMUTABLE_FL)
4784 inode->i_flags |= S_IMMUTABLE;
4785 if (flags & EXT4_NOATIME_FL)
4786 inode->i_flags |= S_NOATIME;
4787 if (flags & EXT4_DIRSYNC_FL)
4788 inode->i_flags |= S_DIRSYNC;
4791 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4792 void ext4_get_inode_flags(struct ext4_inode_info *ei)
4794 unsigned int vfs_fl;
4795 unsigned long old_fl, new_fl;
4798 vfs_fl = ei->vfs_inode.i_flags;
4799 old_fl = ei->i_flags;
4800 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
4801 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
4803 if (vfs_fl & S_SYNC)
4804 new_fl |= EXT4_SYNC_FL;
4805 if (vfs_fl & S_APPEND)
4806 new_fl |= EXT4_APPEND_FL;
4807 if (vfs_fl & S_IMMUTABLE)
4808 new_fl |= EXT4_IMMUTABLE_FL;
4809 if (vfs_fl & S_NOATIME)
4810 new_fl |= EXT4_NOATIME_FL;
4811 if (vfs_fl & S_DIRSYNC)
4812 new_fl |= EXT4_DIRSYNC_FL;
4813 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
4816 static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
4817 struct ext4_inode_info *ei)
4820 struct inode *inode = &(ei->vfs_inode);
4821 struct super_block *sb = inode->i_sb;
4823 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4824 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
4825 /* we are using combined 48 bit field */
4826 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
4827 le32_to_cpu(raw_inode->i_blocks_lo);
4828 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
4829 /* i_blocks represent file system block size */
4830 return i_blocks << (inode->i_blkbits - 9);
4835 return le32_to_cpu(raw_inode->i_blocks_lo);
4839 struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
4841 struct ext4_iloc iloc;
4842 struct ext4_inode *raw_inode;
4843 struct ext4_inode_info *ei;
4844 struct inode *inode;
4845 journal_t *journal = EXT4_SB(sb)->s_journal;
4849 inode = iget_locked(sb, ino);
4851 return ERR_PTR(-ENOMEM);
4852 if (!(inode->i_state & I_NEW))
4858 ret = __ext4_get_inode_loc(inode, &iloc, 0);
4861 raw_inode = ext4_raw_inode(&iloc);
4862 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4863 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4864 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
4865 if (!(test_opt(inode->i_sb, NO_UID32))) {
4866 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4867 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4869 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
4871 ei->i_state_flags = 0;
4872 ei->i_dir_start_lookup = 0;
4873 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4874 /* We now have enough fields to check if the inode was active or not.
4875 * This is needed because nfsd might try to access dead inodes
4876 * the test is that same one that e2fsck uses
4877 * NeilBrown 1999oct15
4879 if (inode->i_nlink == 0) {
4880 if (inode->i_mode == 0 ||
4881 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
4882 /* this inode is deleted */
4886 /* The only unlinked inodes we let through here have
4887 * valid i_mode and are being read by the orphan
4888 * recovery code: that's fine, we're about to complete
4889 * the process of deleting those. */
4891 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
4892 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
4893 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
4894 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
4896 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
4897 inode->i_size = ext4_isize(raw_inode);
4898 ei->i_disksize = inode->i_size;
4900 ei->i_reserved_quota = 0;
4902 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4903 ei->i_block_group = iloc.block_group;
4904 ei->i_last_alloc_group = ~0;
4906 * NOTE! The in-memory inode i_data array is in little-endian order
4907 * even on big-endian machines: we do NOT byteswap the block numbers!
4909 for (block = 0; block < EXT4_N_BLOCKS; block++)
4910 ei->i_data[block] = raw_inode->i_block[block];
4911 INIT_LIST_HEAD(&ei->i_orphan);
4914 * Set transaction id's of transactions that have to be committed
4915 * to finish f[data]sync. We set them to currently running transaction
4916 * as we cannot be sure that the inode or some of its metadata isn't
4917 * part of the transaction - the inode could have been reclaimed and
4918 * now it is reread from disk.
4921 transaction_t *transaction;
4924 read_lock(&journal->j_state_lock);
4925 if (journal->j_running_transaction)
4926 transaction = journal->j_running_transaction;
4928 transaction = journal->j_committing_transaction;
4930 tid = transaction->t_tid;
4932 tid = journal->j_commit_sequence;
4933 read_unlock(&journal->j_state_lock);
4934 ei->i_sync_tid = tid;
4935 ei->i_datasync_tid = tid;
4938 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4939 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
4940 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
4941 EXT4_INODE_SIZE(inode->i_sb)) {
4945 if (ei->i_extra_isize == 0) {
4946 /* The extra space is currently unused. Use it. */
4947 ei->i_extra_isize = sizeof(struct ext4_inode) -
4948 EXT4_GOOD_OLD_INODE_SIZE;
4950 __le32 *magic = (void *)raw_inode +
4951 EXT4_GOOD_OLD_INODE_SIZE +
4953 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
4954 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
4957 ei->i_extra_isize = 0;
4959 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
4960 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
4961 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
4962 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4964 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
4965 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4966 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4968 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4972 if (ei->i_file_acl &&
4973 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
4974 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
4978 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
4979 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4980 (S_ISLNK(inode->i_mode) &&
4981 !ext4_inode_is_fast_symlink(inode)))
4982 /* Validate extent which is part of inode */
4983 ret = ext4_ext_check_inode(inode);
4984 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4985 (S_ISLNK(inode->i_mode) &&
4986 !ext4_inode_is_fast_symlink(inode))) {
4987 /* Validate block references which are part of inode */
4988 ret = ext4_check_inode_blockref(inode);
4993 if (S_ISREG(inode->i_mode)) {
4994 inode->i_op = &ext4_file_inode_operations;
4995 inode->i_fop = &ext4_file_operations;
4996 ext4_set_aops(inode);
4997 } else if (S_ISDIR(inode->i_mode)) {
4998 inode->i_op = &ext4_dir_inode_operations;
4999 inode->i_fop = &ext4_dir_operations;
5000 } else if (S_ISLNK(inode->i_mode)) {
5001 if (ext4_inode_is_fast_symlink(inode)) {
5002 inode->i_op = &ext4_fast_symlink_inode_operations;
5003 nd_terminate_link(ei->i_data, inode->i_size,
5004 sizeof(ei->i_data) - 1);
5006 inode->i_op = &ext4_symlink_inode_operations;
5007 ext4_set_aops(inode);
5009 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
5010 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
5011 inode->i_op = &ext4_special_inode_operations;
5012 if (raw_inode->i_block[0])
5013 init_special_inode(inode, inode->i_mode,
5014 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
5016 init_special_inode(inode, inode->i_mode,
5017 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
5020 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
5024 ext4_set_inode_flags(inode);
5025 unlock_new_inode(inode);
5031 return ERR_PTR(ret);
5034 static int ext4_inode_blocks_set(handle_t *handle,
5035 struct ext4_inode *raw_inode,
5036 struct ext4_inode_info *ei)
5038 struct inode *inode = &(ei->vfs_inode);
5039 u64 i_blocks = inode->i_blocks;
5040 struct super_block *sb = inode->i_sb;
5042 if (i_blocks <= ~0U) {
5044 * i_blocks can be represnted in a 32 bit variable
5045 * as multiple of 512 bytes
5047 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
5048 raw_inode->i_blocks_high = 0;
5049 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
5052 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
5055 if (i_blocks <= 0xffffffffffffULL) {
5057 * i_blocks can be represented in a 48 bit variable
5058 * as multiple of 512 bytes
5060 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
5061 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
5062 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
5064 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
5065 /* i_block is stored in file system block size */
5066 i_blocks = i_blocks >> (inode->i_blkbits - 9);
5067 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
5068 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
5074 * Post the struct inode info into an on-disk inode location in the
5075 * buffer-cache. This gobbles the caller's reference to the
5076 * buffer_head in the inode location struct.
5078 * The caller must have write access to iloc->bh.
5080 static int ext4_do_update_inode(handle_t *handle,
5081 struct inode *inode,
5082 struct ext4_iloc *iloc)
5084 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
5085 struct ext4_inode_info *ei = EXT4_I(inode);
5086 struct buffer_head *bh = iloc->bh;
5087 int err = 0, rc, block;
5089 /* For fields not not tracking in the in-memory inode,
5090 * initialise them to zero for new inodes. */
5091 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
5092 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
5094 ext4_get_inode_flags(ei);
5095 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
5096 if (!(test_opt(inode->i_sb, NO_UID32))) {
5097 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
5098 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
5100 * Fix up interoperability with old kernels. Otherwise, old inodes get
5101 * re-used with the upper 16 bits of the uid/gid intact
5104 raw_inode->i_uid_high =
5105 cpu_to_le16(high_16_bits(inode->i_uid));
5106 raw_inode->i_gid_high =
5107 cpu_to_le16(high_16_bits(inode->i_gid));
5109 raw_inode->i_uid_high = 0;
5110 raw_inode->i_gid_high = 0;
5113 raw_inode->i_uid_low =
5114 cpu_to_le16(fs_high2lowuid(inode->i_uid));
5115 raw_inode->i_gid_low =
5116 cpu_to_le16(fs_high2lowgid(inode->i_gid));
5117 raw_inode->i_uid_high = 0;
5118 raw_inode->i_gid_high = 0;
5120 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
5122 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
5123 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
5124 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
5125 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
5127 if (ext4_inode_blocks_set(handle, raw_inode, ei))
5129 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
5130 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
5131 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
5132 cpu_to_le32(EXT4_OS_HURD))
5133 raw_inode->i_file_acl_high =
5134 cpu_to_le16(ei->i_file_acl >> 32);
5135 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
5136 ext4_isize_set(raw_inode, ei->i_disksize);
5137 if (ei->i_disksize > 0x7fffffffULL) {
5138 struct super_block *sb = inode->i_sb;
5139 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
5140 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
5141 EXT4_SB(sb)->s_es->s_rev_level ==
5142 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
5143 /* If this is the first large file
5144 * created, add a flag to the superblock.
5146 err = ext4_journal_get_write_access(handle,
5147 EXT4_SB(sb)->s_sbh);
5150 ext4_update_dynamic_rev(sb);
5151 EXT4_SET_RO_COMPAT_FEATURE(sb,
5152 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
5154 ext4_handle_sync(handle);
5155 err = ext4_handle_dirty_metadata(handle, NULL,
5156 EXT4_SB(sb)->s_sbh);
5159 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
5160 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
5161 if (old_valid_dev(inode->i_rdev)) {
5162 raw_inode->i_block[0] =
5163 cpu_to_le32(old_encode_dev(inode->i_rdev));
5164 raw_inode->i_block[1] = 0;
5166 raw_inode->i_block[0] = 0;
5167 raw_inode->i_block[1] =
5168 cpu_to_le32(new_encode_dev(inode->i_rdev));
5169 raw_inode->i_block[2] = 0;
5172 for (block = 0; block < EXT4_N_BLOCKS; block++)
5173 raw_inode->i_block[block] = ei->i_data[block];
5175 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
5176 if (ei->i_extra_isize) {
5177 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
5178 raw_inode->i_version_hi =
5179 cpu_to_le32(inode->i_version >> 32);
5180 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
5183 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
5184 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
5187 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
5189 ext4_update_inode_fsync_trans(handle, inode, 0);
5192 ext4_std_error(inode->i_sb, err);
5197 * ext4_write_inode()
5199 * We are called from a few places:
5201 * - Within generic_file_write() for O_SYNC files.
5202 * Here, there will be no transaction running. We wait for any running
5203 * trasnaction to commit.
5205 * - Within sys_sync(), kupdate and such.
5206 * We wait on commit, if tol to.
5208 * - Within prune_icache() (PF_MEMALLOC == true)
5209 * Here we simply return. We can't afford to block kswapd on the
5212 * In all cases it is actually safe for us to return without doing anything,
5213 * because the inode has been copied into a raw inode buffer in
5214 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5217 * Note that we are absolutely dependent upon all inode dirtiers doing the
5218 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5219 * which we are interested.
5221 * It would be a bug for them to not do this. The code:
5223 * mark_inode_dirty(inode)
5225 * inode->i_size = expr;
5227 * is in error because a kswapd-driven write_inode() could occur while
5228 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5229 * will no longer be on the superblock's dirty inode list.
5231 int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
5235 if (current->flags & PF_MEMALLOC)
5238 if (EXT4_SB(inode->i_sb)->s_journal) {
5239 if (ext4_journal_current_handle()) {
5240 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5245 if (wbc->sync_mode != WB_SYNC_ALL)
5248 err = ext4_force_commit(inode->i_sb);
5250 struct ext4_iloc iloc;
5252 err = __ext4_get_inode_loc(inode, &iloc, 0);
5255 if (wbc->sync_mode == WB_SYNC_ALL)
5256 sync_dirty_buffer(iloc.bh);
5257 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
5258 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
5259 "IO error syncing inode");
5270 * Called from notify_change.
5272 * We want to trap VFS attempts to truncate the file as soon as
5273 * possible. In particular, we want to make sure that when the VFS
5274 * shrinks i_size, we put the inode on the orphan list and modify
5275 * i_disksize immediately, so that during the subsequent flushing of
5276 * dirty pages and freeing of disk blocks, we can guarantee that any
5277 * commit will leave the blocks being flushed in an unused state on
5278 * disk. (On recovery, the inode will get truncated and the blocks will
5279 * be freed, so we have a strong guarantee that no future commit will
5280 * leave these blocks visible to the user.)
5282 * Another thing we have to assure is that if we are in ordered mode
5283 * and inode is still attached to the committing transaction, we must
5284 * we start writeout of all the dirty pages which are being truncated.
5285 * This way we are sure that all the data written in the previous
5286 * transaction are already on disk (truncate waits for pages under
5289 * Called with inode->i_mutex down.
5291 int ext4_setattr(struct dentry *dentry, struct iattr *attr)
5293 struct inode *inode = dentry->d_inode;
5296 const unsigned int ia_valid = attr->ia_valid;
5298 error = inode_change_ok(inode, attr);
5302 if (is_quota_modification(inode, attr))
5303 dquot_initialize(inode);
5304 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
5305 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
5308 /* (user+group)*(old+new) structure, inode write (sb,
5309 * inode block, ? - but truncate inode update has it) */
5310 handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
5311 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3);
5312 if (IS_ERR(handle)) {
5313 error = PTR_ERR(handle);
5316 error = dquot_transfer(inode, attr);
5318 ext4_journal_stop(handle);
5321 /* Update corresponding info in inode so that everything is in
5322 * one transaction */
5323 if (attr->ia_valid & ATTR_UID)
5324 inode->i_uid = attr->ia_uid;
5325 if (attr->ia_valid & ATTR_GID)
5326 inode->i_gid = attr->ia_gid;
5327 error = ext4_mark_inode_dirty(handle, inode);
5328 ext4_journal_stop(handle);
5331 if (attr->ia_valid & ATTR_SIZE) {
5332 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
5333 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5335 if (attr->ia_size > sbi->s_bitmap_maxbytes)
5340 if (S_ISREG(inode->i_mode) &&
5341 attr->ia_valid & ATTR_SIZE &&
5342 (attr->ia_size < inode->i_size ||
5343 (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))) {
5346 handle = ext4_journal_start(inode, 3);
5347 if (IS_ERR(handle)) {
5348 error = PTR_ERR(handle);
5351 if (ext4_handle_valid(handle)) {
5352 error = ext4_orphan_add(handle, inode);
5355 EXT4_I(inode)->i_disksize = attr->ia_size;
5356 rc = ext4_mark_inode_dirty(handle, inode);
5359 ext4_journal_stop(handle);
5361 if (ext4_should_order_data(inode)) {
5362 error = ext4_begin_ordered_truncate(inode,
5365 /* Do as much error cleanup as possible */
5366 handle = ext4_journal_start(inode, 3);
5367 if (IS_ERR(handle)) {
5368 ext4_orphan_del(NULL, inode);
5371 ext4_orphan_del(handle, inode);
5373 ext4_journal_stop(handle);
5377 /* ext4_truncate will clear the flag */
5378 if ((ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))
5379 ext4_truncate(inode);
5382 if ((attr->ia_valid & ATTR_SIZE) &&
5383 attr->ia_size != i_size_read(inode))
5384 rc = vmtruncate(inode, attr->ia_size);
5387 setattr_copy(inode, attr);
5388 mark_inode_dirty(inode);
5392 * If the call to ext4_truncate failed to get a transaction handle at
5393 * all, we need to clean up the in-core orphan list manually.
5395 if (orphan && inode->i_nlink)
5396 ext4_orphan_del(NULL, inode);
5398 if (!rc && (ia_valid & ATTR_MODE))
5399 rc = ext4_acl_chmod(inode);
5402 ext4_std_error(inode->i_sb, error);
5408 int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
5411 struct inode *inode;
5412 unsigned long delalloc_blocks;
5414 inode = dentry->d_inode;
5415 generic_fillattr(inode, stat);
5418 * We can't update i_blocks if the block allocation is delayed
5419 * otherwise in the case of system crash before the real block
5420 * allocation is done, we will have i_blocks inconsistent with
5421 * on-disk file blocks.
5422 * We always keep i_blocks updated together with real
5423 * allocation. But to not confuse with user, stat
5424 * will return the blocks that include the delayed allocation
5425 * blocks for this file.
5427 delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
5429 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
5433 static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
5438 /* if nrblocks are contiguous */
5441 * With N contiguous data blocks, it need at most
5442 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5443 * 2 dindirect blocks
5446 indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
5447 return indirects + 3;
5450 * if nrblocks are not contiguous, worse case, each block touch
5451 * a indirect block, and each indirect block touch a double indirect
5452 * block, plus a triple indirect block
5454 indirects = nrblocks * 2 + 1;
5458 static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
5460 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5461 return ext4_indirect_trans_blocks(inode, nrblocks, chunk);
5462 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
5466 * Account for index blocks, block groups bitmaps and block group
5467 * descriptor blocks if modify datablocks and index blocks
5468 * worse case, the indexs blocks spread over different block groups
5470 * If datablocks are discontiguous, they are possible to spread over
5471 * different block groups too. If they are contiuguous, with flexbg,
5472 * they could still across block group boundary.
5474 * Also account for superblock, inode, quota and xattr blocks
5476 static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
5478 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
5484 * How many index blocks need to touch to modify nrblocks?
5485 * The "Chunk" flag indicating whether the nrblocks is
5486 * physically contiguous on disk
5488 * For Direct IO and fallocate, they calls get_block to allocate
5489 * one single extent at a time, so they could set the "Chunk" flag
5491 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
5496 * Now let's see how many group bitmaps and group descriptors need
5506 if (groups > ngroups)
5508 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
5509 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
5511 /* bitmaps and block group descriptor blocks */
5512 ret += groups + gdpblocks;
5514 /* Blocks for super block, inode, quota and xattr blocks */
5515 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
5521 * Calulate the total number of credits to reserve to fit
5522 * the modification of a single pages into a single transaction,
5523 * which may include multiple chunks of block allocations.
5525 * This could be called via ext4_write_begin()
5527 * We need to consider the worse case, when
5528 * one new block per extent.
5530 int ext4_writepage_trans_blocks(struct inode *inode)
5532 int bpp = ext4_journal_blocks_per_page(inode);
5535 ret = ext4_meta_trans_blocks(inode, bpp, 0);
5537 /* Account for data blocks for journalled mode */
5538 if (ext4_should_journal_data(inode))
5544 * Calculate the journal credits for a chunk of data modification.
5546 * This is called from DIO, fallocate or whoever calling
5547 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
5549 * journal buffers for data blocks are not included here, as DIO
5550 * and fallocate do no need to journal data buffers.
5552 int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
5554 return ext4_meta_trans_blocks(inode, nrblocks, 1);
5558 * The caller must have previously called ext4_reserve_inode_write().
5559 * Give this, we know that the caller already has write access to iloc->bh.
5561 int ext4_mark_iloc_dirty(handle_t *handle,
5562 struct inode *inode, struct ext4_iloc *iloc)
5566 if (test_opt(inode->i_sb, I_VERSION))
5567 inode_inc_iversion(inode);
5569 /* the do_update_inode consumes one bh->b_count */
5572 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5573 err = ext4_do_update_inode(handle, inode, iloc);
5579 * On success, We end up with an outstanding reference count against
5580 * iloc->bh. This _must_ be cleaned up later.
5584 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
5585 struct ext4_iloc *iloc)
5589 err = ext4_get_inode_loc(inode, iloc);
5591 BUFFER_TRACE(iloc->bh, "get_write_access");
5592 err = ext4_journal_get_write_access(handle, iloc->bh);
5598 ext4_std_error(inode->i_sb, err);
5603 * Expand an inode by new_extra_isize bytes.
5604 * Returns 0 on success or negative error number on failure.
5606 static int ext4_expand_extra_isize(struct inode *inode,
5607 unsigned int new_extra_isize,
5608 struct ext4_iloc iloc,
5611 struct ext4_inode *raw_inode;
5612 struct ext4_xattr_ibody_header *header;
5614 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
5617 raw_inode = ext4_raw_inode(&iloc);
5619 header = IHDR(inode, raw_inode);
5621 /* No extended attributes present */
5622 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
5623 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
5624 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
5626 EXT4_I(inode)->i_extra_isize = new_extra_isize;
5630 /* try to expand with EAs present */
5631 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
5636 * What we do here is to mark the in-core inode as clean with respect to inode
5637 * dirtiness (it may still be data-dirty).
5638 * This means that the in-core inode may be reaped by prune_icache
5639 * without having to perform any I/O. This is a very good thing,
5640 * because *any* task may call prune_icache - even ones which
5641 * have a transaction open against a different journal.
5643 * Is this cheating? Not really. Sure, we haven't written the
5644 * inode out, but prune_icache isn't a user-visible syncing function.
5645 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5646 * we start and wait on commits.
5648 * Is this efficient/effective? Well, we're being nice to the system
5649 * by cleaning up our inodes proactively so they can be reaped
5650 * without I/O. But we are potentially leaving up to five seconds'
5651 * worth of inodes floating about which prune_icache wants us to
5652 * write out. One way to fix that would be to get prune_icache()
5653 * to do a write_super() to free up some memory. It has the desired
5656 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
5658 struct ext4_iloc iloc;
5659 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5660 static unsigned int mnt_count;
5664 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
5665 err = ext4_reserve_inode_write(handle, inode, &iloc);
5666 if (ext4_handle_valid(handle) &&
5667 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
5668 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
5670 * We need extra buffer credits since we may write into EA block
5671 * with this same handle. If journal_extend fails, then it will
5672 * only result in a minor loss of functionality for that inode.
5673 * If this is felt to be critical, then e2fsck should be run to
5674 * force a large enough s_min_extra_isize.
5676 if ((jbd2_journal_extend(handle,
5677 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
5678 ret = ext4_expand_extra_isize(inode,
5679 sbi->s_want_extra_isize,
5682 ext4_set_inode_state(inode,
5683 EXT4_STATE_NO_EXPAND);
5685 le16_to_cpu(sbi->s_es->s_mnt_count)) {
5686 ext4_warning(inode->i_sb,
5687 "Unable to expand inode %lu. Delete"
5688 " some EAs or run e2fsck.",
5691 le16_to_cpu(sbi->s_es->s_mnt_count);
5697 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
5702 * ext4_dirty_inode() is called from __mark_inode_dirty()
5704 * We're really interested in the case where a file is being extended.
5705 * i_size has been changed by generic_commit_write() and we thus need
5706 * to include the updated inode in the current transaction.
5708 * Also, dquot_alloc_block() will always dirty the inode when blocks
5709 * are allocated to the file.
5711 * If the inode is marked synchronous, we don't honour that here - doing
5712 * so would cause a commit on atime updates, which we don't bother doing.
5713 * We handle synchronous inodes at the highest possible level.
5715 void ext4_dirty_inode(struct inode *inode)
5719 handle = ext4_journal_start(inode, 2);
5723 ext4_mark_inode_dirty(handle, inode);
5725 ext4_journal_stop(handle);
5732 * Bind an inode's backing buffer_head into this transaction, to prevent
5733 * it from being flushed to disk early. Unlike
5734 * ext4_reserve_inode_write, this leaves behind no bh reference and
5735 * returns no iloc structure, so the caller needs to repeat the iloc
5736 * lookup to mark the inode dirty later.
5738 static int ext4_pin_inode(handle_t *handle, struct inode *inode)
5740 struct ext4_iloc iloc;
5744 err = ext4_get_inode_loc(inode, &iloc);
5746 BUFFER_TRACE(iloc.bh, "get_write_access");
5747 err = jbd2_journal_get_write_access(handle, iloc.bh);
5749 err = ext4_handle_dirty_metadata(handle,
5755 ext4_std_error(inode->i_sb, err);
5760 int ext4_change_inode_journal_flag(struct inode *inode, int val)
5767 * We have to be very careful here: changing a data block's
5768 * journaling status dynamically is dangerous. If we write a
5769 * data block to the journal, change the status and then delete
5770 * that block, we risk forgetting to revoke the old log record
5771 * from the journal and so a subsequent replay can corrupt data.
5772 * So, first we make sure that the journal is empty and that
5773 * nobody is changing anything.
5776 journal = EXT4_JOURNAL(inode);
5779 if (is_journal_aborted(journal))
5782 jbd2_journal_lock_updates(journal);
5783 jbd2_journal_flush(journal);
5786 * OK, there are no updates running now, and all cached data is
5787 * synced to disk. We are now in a completely consistent state
5788 * which doesn't have anything in the journal, and we know that
5789 * no filesystem updates are running, so it is safe to modify
5790 * the inode's in-core data-journaling state flag now.
5794 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5796 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5797 ext4_set_aops(inode);
5799 jbd2_journal_unlock_updates(journal);
5801 /* Finally we can mark the inode as dirty. */
5803 handle = ext4_journal_start(inode, 1);
5805 return PTR_ERR(handle);
5807 err = ext4_mark_inode_dirty(handle, inode);
5808 ext4_handle_sync(handle);
5809 ext4_journal_stop(handle);
5810 ext4_std_error(inode->i_sb, err);
5815 static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
5817 return !buffer_mapped(bh);
5820 int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
5822 struct page *page = vmf->page;
5827 struct file *file = vma->vm_file;
5828 struct inode *inode = file->f_path.dentry->d_inode;
5829 struct address_space *mapping = inode->i_mapping;
5832 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
5833 * get i_mutex because we are already holding mmap_sem.
5835 down_read(&inode->i_alloc_sem);
5836 size = i_size_read(inode);
5837 if (page->mapping != mapping || size <= page_offset(page)
5838 || !PageUptodate(page)) {
5839 /* page got truncated from under us? */
5843 if (PageMappedToDisk(page))
5846 if (page->index == size >> PAGE_CACHE_SHIFT)
5847 len = size & ~PAGE_CACHE_MASK;
5849 len = PAGE_CACHE_SIZE;
5853 * return if we have all the buffers mapped. This avoid
5854 * the need to call write_begin/write_end which does a
5855 * journal_start/journal_stop which can block and take
5858 if (page_has_buffers(page)) {
5859 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
5860 ext4_bh_unmapped)) {
5867 * OK, we need to fill the hole... Do write_begin write_end
5868 * to do block allocation/reservation.We are not holding
5869 * inode.i__mutex here. That allow * parallel write_begin,
5870 * write_end call. lock_page prevent this from happening
5871 * on the same page though
5873 ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
5874 len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
5877 ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
5878 len, len, page, fsdata);
5884 ret = VM_FAULT_SIGBUS;
5885 up_read(&inode->i_alloc_sem);