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>
44 #include "ext4_jbd2.h"
47 #include "ext4_extents.h"
49 #include <trace/events/ext4.h>
51 #define MPAGE_DA_EXTENT_TAIL 0x01
53 static inline int ext4_begin_ordered_truncate(struct inode *inode,
56 return jbd2_journal_begin_ordered_truncate(
57 EXT4_SB(inode->i_sb)->s_journal,
58 &EXT4_I(inode)->jinode,
62 static void ext4_invalidatepage(struct page *page, unsigned long offset);
63 static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
64 struct buffer_head *bh_result, int create);
65 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
66 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
67 static int __ext4_journalled_writepage(struct page *page, unsigned int len);
68 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
71 * Test whether an inode is a fast symlink.
73 static int ext4_inode_is_fast_symlink(struct inode *inode)
75 int ea_blocks = EXT4_I(inode)->i_file_acl ?
76 (inode->i_sb->s_blocksize >> 9) : 0;
78 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
82 * Work out how many blocks we need to proceed with the next chunk of a
83 * truncate transaction.
85 static unsigned long blocks_for_truncate(struct inode *inode)
89 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
91 /* Give ourselves just enough room to cope with inodes in which
92 * i_blocks is corrupt: we've seen disk corruptions in the past
93 * which resulted in random data in an inode which looked enough
94 * like a regular file for ext4 to try to delete it. Things
95 * will go a bit crazy if that happens, but at least we should
96 * try not to panic the whole kernel. */
100 /* But we need to bound the transaction so we don't overflow the
102 if (needed > EXT4_MAX_TRANS_DATA)
103 needed = EXT4_MAX_TRANS_DATA;
105 return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
109 * Truncate transactions can be complex and absolutely huge. So we need to
110 * be able to restart the transaction at a conventient checkpoint to make
111 * sure we don't overflow the journal.
113 * start_transaction gets us a new handle for a truncate transaction,
114 * and extend_transaction tries to extend the existing one a bit. If
115 * extend fails, we need to propagate the failure up and restart the
116 * transaction in the top-level truncate loop. --sct
118 static handle_t *start_transaction(struct inode *inode)
122 result = ext4_journal_start(inode, blocks_for_truncate(inode));
126 ext4_std_error(inode->i_sb, PTR_ERR(result));
131 * Try to extend this transaction for the purposes of truncation.
133 * Returns 0 if we managed to create more room. If we can't create more
134 * room, and the transaction must be restarted we return 1.
136 static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
138 if (!ext4_handle_valid(handle))
140 if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
142 if (!ext4_journal_extend(handle, blocks_for_truncate(inode)))
148 * Restart the transaction associated with *handle. This does a commit,
149 * so before we call here everything must be consistently dirtied against
152 int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
158 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
159 * moment, get_block can be called only for blocks inside i_size since
160 * page cache has been already dropped and writes are blocked by
161 * i_mutex. So we can safely drop the i_data_sem here.
163 BUG_ON(EXT4_JOURNAL(inode) == NULL);
164 jbd_debug(2, "restarting handle %p\n", handle);
165 up_write(&EXT4_I(inode)->i_data_sem);
166 ret = ext4_journal_restart(handle, blocks_for_truncate(inode));
167 down_write(&EXT4_I(inode)->i_data_sem);
168 ext4_discard_preallocations(inode);
174 * Called at the last iput() if i_nlink is zero.
176 void ext4_evict_inode(struct inode *inode)
181 if (inode->i_nlink) {
182 truncate_inode_pages(&inode->i_data, 0);
186 if (!is_bad_inode(inode))
187 dquot_initialize(inode);
189 if (ext4_should_order_data(inode))
190 ext4_begin_ordered_truncate(inode, 0);
191 truncate_inode_pages(&inode->i_data, 0);
193 if (is_bad_inode(inode))
196 handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
197 if (IS_ERR(handle)) {
198 ext4_std_error(inode->i_sb, PTR_ERR(handle));
200 * If we're going to skip the normal cleanup, we still need to
201 * make sure that the in-core orphan linked list is properly
204 ext4_orphan_del(NULL, inode);
209 ext4_handle_sync(handle);
211 err = ext4_mark_inode_dirty(handle, inode);
213 ext4_warning(inode->i_sb,
214 "couldn't mark inode dirty (err %d)", err);
218 ext4_truncate(inode);
221 * ext4_ext_truncate() doesn't reserve any slop when it
222 * restarts journal transactions; therefore there may not be
223 * enough credits left in the handle to remove the inode from
224 * the orphan list and set the dtime field.
226 if (!ext4_handle_has_enough_credits(handle, 3)) {
227 err = ext4_journal_extend(handle, 3);
229 err = ext4_journal_restart(handle, 3);
231 ext4_warning(inode->i_sb,
232 "couldn't extend journal (err %d)", err);
234 ext4_journal_stop(handle);
235 ext4_orphan_del(NULL, inode);
241 * Kill off the orphan record which ext4_truncate created.
242 * AKPM: I think this can be inside the above `if'.
243 * Note that ext4_orphan_del() has to be able to cope with the
244 * deletion of a non-existent orphan - this is because we don't
245 * know if ext4_truncate() actually created an orphan record.
246 * (Well, we could do this if we need to, but heck - it works)
248 ext4_orphan_del(handle, inode);
249 EXT4_I(inode)->i_dtime = get_seconds();
252 * One subtle ordering requirement: if anything has gone wrong
253 * (transaction abort, IO errors, whatever), then we can still
254 * do these next steps (the fs will already have been marked as
255 * having errors), but we can't free the inode if the mark_dirty
258 if (ext4_mark_inode_dirty(handle, inode))
259 /* If that failed, just do the required in-core inode clear. */
260 ext4_clear_inode(inode);
262 ext4_free_inode(handle, inode);
263 ext4_journal_stop(handle);
266 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
272 struct buffer_head *bh;
275 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
277 p->key = *(p->p = v);
282 * ext4_block_to_path - parse the block number into array of offsets
283 * @inode: inode in question (we are only interested in its superblock)
284 * @i_block: block number to be parsed
285 * @offsets: array to store the offsets in
286 * @boundary: set this non-zero if the referred-to block is likely to be
287 * followed (on disk) by an indirect block.
289 * To store the locations of file's data ext4 uses a data structure common
290 * for UNIX filesystems - tree of pointers anchored in the inode, with
291 * data blocks at leaves and indirect blocks in intermediate nodes.
292 * This function translates the block number into path in that tree -
293 * return value is the path length and @offsets[n] is the offset of
294 * pointer to (n+1)th node in the nth one. If @block is out of range
295 * (negative or too large) warning is printed and zero returned.
297 * Note: function doesn't find node addresses, so no IO is needed. All
298 * we need to know is the capacity of indirect blocks (taken from the
303 * Portability note: the last comparison (check that we fit into triple
304 * indirect block) is spelled differently, because otherwise on an
305 * architecture with 32-bit longs and 8Kb pages we might get into trouble
306 * if our filesystem had 8Kb blocks. We might use long long, but that would
307 * kill us on x86. Oh, well, at least the sign propagation does not matter -
308 * i_block would have to be negative in the very beginning, so we would not
312 static int ext4_block_to_path(struct inode *inode,
314 ext4_lblk_t offsets[4], int *boundary)
316 int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
317 int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
318 const long direct_blocks = EXT4_NDIR_BLOCKS,
319 indirect_blocks = ptrs,
320 double_blocks = (1 << (ptrs_bits * 2));
324 if (i_block < direct_blocks) {
325 offsets[n++] = i_block;
326 final = direct_blocks;
327 } else if ((i_block -= direct_blocks) < indirect_blocks) {
328 offsets[n++] = EXT4_IND_BLOCK;
329 offsets[n++] = i_block;
331 } else if ((i_block -= indirect_blocks) < double_blocks) {
332 offsets[n++] = EXT4_DIND_BLOCK;
333 offsets[n++] = i_block >> ptrs_bits;
334 offsets[n++] = i_block & (ptrs - 1);
336 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
337 offsets[n++] = EXT4_TIND_BLOCK;
338 offsets[n++] = i_block >> (ptrs_bits * 2);
339 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
340 offsets[n++] = i_block & (ptrs - 1);
343 ext4_warning(inode->i_sb, "block %lu > max in inode %lu",
344 i_block + direct_blocks +
345 indirect_blocks + double_blocks, inode->i_ino);
348 *boundary = final - 1 - (i_block & (ptrs - 1));
352 static int __ext4_check_blockref(const char *function, unsigned int line,
354 __le32 *p, unsigned int max)
356 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
360 while (bref < p+max) {
361 blk = le32_to_cpu(*bref++);
363 unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb),
365 es->s_last_error_block = cpu_to_le64(blk);
366 ext4_error_inode(inode, function, line, blk,
375 #define ext4_check_indirect_blockref(inode, bh) \
376 __ext4_check_blockref(__func__, __LINE__, inode, \
377 (__le32 *)(bh)->b_data, \
378 EXT4_ADDR_PER_BLOCK((inode)->i_sb))
380 #define ext4_check_inode_blockref(inode) \
381 __ext4_check_blockref(__func__, __LINE__, inode, \
382 EXT4_I(inode)->i_data, \
386 * ext4_get_branch - read the chain of indirect blocks leading to data
387 * @inode: inode in question
388 * @depth: depth of the chain (1 - direct pointer, etc.)
389 * @offsets: offsets of pointers in inode/indirect blocks
390 * @chain: place to store the result
391 * @err: here we store the error value
393 * Function fills the array of triples <key, p, bh> and returns %NULL
394 * if everything went OK or the pointer to the last filled triple
395 * (incomplete one) otherwise. Upon the return chain[i].key contains
396 * the number of (i+1)-th block in the chain (as it is stored in memory,
397 * i.e. little-endian 32-bit), chain[i].p contains the address of that
398 * number (it points into struct inode for i==0 and into the bh->b_data
399 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
400 * block for i>0 and NULL for i==0. In other words, it holds the block
401 * numbers of the chain, addresses they were taken from (and where we can
402 * verify that chain did not change) and buffer_heads hosting these
405 * Function stops when it stumbles upon zero pointer (absent block)
406 * (pointer to last triple returned, *@err == 0)
407 * or when it gets an IO error reading an indirect block
408 * (ditto, *@err == -EIO)
409 * or when it reads all @depth-1 indirect blocks successfully and finds
410 * the whole chain, all way to the data (returns %NULL, *err == 0).
412 * Need to be called with
413 * down_read(&EXT4_I(inode)->i_data_sem)
415 static Indirect *ext4_get_branch(struct inode *inode, int depth,
416 ext4_lblk_t *offsets,
417 Indirect chain[4], int *err)
419 struct super_block *sb = inode->i_sb;
421 struct buffer_head *bh;
424 /* i_data is not going away, no lock needed */
425 add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
429 bh = sb_getblk(sb, le32_to_cpu(p->key));
433 if (!bh_uptodate_or_lock(bh)) {
434 if (bh_submit_read(bh) < 0) {
438 /* validate block references */
439 if (ext4_check_indirect_blockref(inode, bh)) {
445 add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
459 * ext4_find_near - find a place for allocation with sufficient locality
461 * @ind: descriptor of indirect block.
463 * This function returns the preferred place for block allocation.
464 * It is used when heuristic for sequential allocation fails.
466 * + if there is a block to the left of our position - allocate near it.
467 * + if pointer will live in indirect block - allocate near that block.
468 * + if pointer will live in inode - allocate in the same
471 * In the latter case we colour the starting block by the callers PID to
472 * prevent it from clashing with concurrent allocations for a different inode
473 * in the same block group. The PID is used here so that functionally related
474 * files will be close-by on-disk.
476 * Caller must make sure that @ind is valid and will stay that way.
478 static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
480 struct ext4_inode_info *ei = EXT4_I(inode);
481 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
483 ext4_fsblk_t bg_start;
484 ext4_fsblk_t last_block;
485 ext4_grpblk_t colour;
486 ext4_group_t block_group;
487 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
489 /* Try to find previous block */
490 for (p = ind->p - 1; p >= start; p--) {
492 return le32_to_cpu(*p);
495 /* No such thing, so let's try location of indirect block */
497 return ind->bh->b_blocknr;
500 * It is going to be referred to from the inode itself? OK, just put it
501 * into the same cylinder group then.
503 block_group = ei->i_block_group;
504 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
505 block_group &= ~(flex_size-1);
506 if (S_ISREG(inode->i_mode))
509 bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
510 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
513 * If we are doing delayed allocation, we don't need take
514 * colour into account.
516 if (test_opt(inode->i_sb, DELALLOC))
519 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
520 colour = (current->pid % 16) *
521 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
523 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
524 return bg_start + colour;
528 * ext4_find_goal - find a preferred place for allocation.
530 * @block: block we want
531 * @partial: pointer to the last triple within a chain
533 * Normally this function find the preferred place for block allocation,
535 * Because this is only used for non-extent files, we limit the block nr
538 static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
544 * XXX need to get goal block from mballoc's data structures
547 goal = ext4_find_near(inode, partial);
548 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
553 * ext4_blks_to_allocate: Look up the block map and count the number
554 * of direct blocks need to be allocated for the given branch.
556 * @branch: chain of indirect blocks
557 * @k: number of blocks need for indirect blocks
558 * @blks: number of data blocks to be mapped.
559 * @blocks_to_boundary: the offset in the indirect block
561 * return the total number of blocks to be allocate, including the
562 * direct and indirect blocks.
564 static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
565 int blocks_to_boundary)
567 unsigned int count = 0;
570 * Simple case, [t,d]Indirect block(s) has not allocated yet
571 * then it's clear blocks on that path have not allocated
574 /* right now we don't handle cross boundary allocation */
575 if (blks < blocks_to_boundary + 1)
578 count += blocks_to_boundary + 1;
583 while (count < blks && count <= blocks_to_boundary &&
584 le32_to_cpu(*(branch[0].p + count)) == 0) {
591 * ext4_alloc_blocks: multiple allocate blocks needed for a branch
592 * @indirect_blks: the number of blocks need to allocate for indirect
595 * @new_blocks: on return it will store the new block numbers for
596 * the indirect blocks(if needed) and the first direct block,
597 * @blks: on return it will store the total number of allocated
600 static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
601 ext4_lblk_t iblock, ext4_fsblk_t goal,
602 int indirect_blks, int blks,
603 ext4_fsblk_t new_blocks[4], int *err)
605 struct ext4_allocation_request ar;
607 unsigned long count = 0, blk_allocated = 0;
609 ext4_fsblk_t current_block = 0;
613 * Here we try to allocate the requested multiple blocks at once,
614 * on a best-effort basis.
615 * To build a branch, we should allocate blocks for
616 * the indirect blocks(if not allocated yet), and at least
617 * the first direct block of this branch. That's the
618 * minimum number of blocks need to allocate(required)
620 /* first we try to allocate the indirect blocks */
621 target = indirect_blks;
624 /* allocating blocks for indirect blocks and direct blocks */
625 current_block = ext4_new_meta_blocks(handle, inode,
630 if (unlikely(current_block + count > EXT4_MAX_BLOCK_FILE_PHYS)) {
631 EXT4_ERROR_INODE(inode,
632 "current_block %llu + count %lu > %d!",
633 current_block, count,
634 EXT4_MAX_BLOCK_FILE_PHYS);
640 /* allocate blocks for indirect blocks */
641 while (index < indirect_blks && count) {
642 new_blocks[index++] = current_block++;
647 * save the new block number
648 * for the first direct block
650 new_blocks[index] = current_block;
651 printk(KERN_INFO "%s returned more blocks than "
652 "requested\n", __func__);
658 target = blks - count ;
659 blk_allocated = count;
662 /* Now allocate data blocks */
663 memset(&ar, 0, sizeof(ar));
668 if (S_ISREG(inode->i_mode))
669 /* enable in-core preallocation only for regular files */
670 ar.flags = EXT4_MB_HINT_DATA;
672 current_block = ext4_mb_new_blocks(handle, &ar, err);
673 if (unlikely(current_block + ar.len > EXT4_MAX_BLOCK_FILE_PHYS)) {
674 EXT4_ERROR_INODE(inode,
675 "current_block %llu + ar.len %d > %d!",
676 current_block, ar.len,
677 EXT4_MAX_BLOCK_FILE_PHYS);
682 if (*err && (target == blks)) {
684 * if the allocation failed and we didn't allocate
690 if (target == blks) {
692 * save the new block number
693 * for the first direct block
695 new_blocks[index] = current_block;
697 blk_allocated += ar.len;
700 /* total number of blocks allocated for direct blocks */
705 for (i = 0; i < index; i++)
706 ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
711 * ext4_alloc_branch - allocate and set up a chain of blocks.
713 * @indirect_blks: number of allocated indirect blocks
714 * @blks: number of allocated direct blocks
715 * @offsets: offsets (in the blocks) to store the pointers to next.
716 * @branch: place to store the chain in.
718 * This function allocates blocks, zeroes out all but the last one,
719 * links them into chain and (if we are synchronous) writes them to disk.
720 * In other words, it prepares a branch that can be spliced onto the
721 * inode. It stores the information about that chain in the branch[], in
722 * the same format as ext4_get_branch() would do. We are calling it after
723 * we had read the existing part of chain and partial points to the last
724 * triple of that (one with zero ->key). Upon the exit we have the same
725 * picture as after the successful ext4_get_block(), except that in one
726 * place chain is disconnected - *branch->p is still zero (we did not
727 * set the last link), but branch->key contains the number that should
728 * be placed into *branch->p to fill that gap.
730 * If allocation fails we free all blocks we've allocated (and forget
731 * their buffer_heads) and return the error value the from failed
732 * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
733 * as described above and return 0.
735 static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
736 ext4_lblk_t iblock, int indirect_blks,
737 int *blks, ext4_fsblk_t goal,
738 ext4_lblk_t *offsets, Indirect *branch)
740 int blocksize = inode->i_sb->s_blocksize;
743 struct buffer_head *bh;
745 ext4_fsblk_t new_blocks[4];
746 ext4_fsblk_t current_block;
748 num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
749 *blks, new_blocks, &err);
753 branch[0].key = cpu_to_le32(new_blocks[0]);
755 * metadata blocks and data blocks are allocated.
757 for (n = 1; n <= indirect_blks; n++) {
759 * Get buffer_head for parent block, zero it out
760 * and set the pointer to new one, then send
763 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
766 BUFFER_TRACE(bh, "call get_create_access");
767 err = ext4_journal_get_create_access(handle, bh);
769 /* Don't brelse(bh) here; it's done in
770 * ext4_journal_forget() below */
775 memset(bh->b_data, 0, blocksize);
776 branch[n].p = (__le32 *) bh->b_data + offsets[n];
777 branch[n].key = cpu_to_le32(new_blocks[n]);
778 *branch[n].p = branch[n].key;
779 if (n == indirect_blks) {
780 current_block = new_blocks[n];
782 * End of chain, update the last new metablock of
783 * the chain to point to the new allocated
784 * data blocks numbers
786 for (i = 1; i < num; i++)
787 *(branch[n].p + i) = cpu_to_le32(++current_block);
789 BUFFER_TRACE(bh, "marking uptodate");
790 set_buffer_uptodate(bh);
793 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
794 err = ext4_handle_dirty_metadata(handle, inode, bh);
801 /* Allocation failed, free what we already allocated */
802 ext4_free_blocks(handle, inode, 0, new_blocks[0], 1, 0);
803 for (i = 1; i <= n ; i++) {
805 * branch[i].bh is newly allocated, so there is no
806 * need to revoke the block, which is why we don't
807 * need to set EXT4_FREE_BLOCKS_METADATA.
809 ext4_free_blocks(handle, inode, 0, new_blocks[i], 1,
810 EXT4_FREE_BLOCKS_FORGET);
812 for (i = n+1; i < indirect_blks; i++)
813 ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
815 ext4_free_blocks(handle, inode, 0, new_blocks[i], num, 0);
821 * ext4_splice_branch - splice the allocated branch onto inode.
823 * @block: (logical) number of block we are adding
824 * @chain: chain of indirect blocks (with a missing link - see
826 * @where: location of missing link
827 * @num: number of indirect blocks we are adding
828 * @blks: number of direct blocks we are adding
830 * This function fills the missing link and does all housekeeping needed in
831 * inode (->i_blocks, etc.). In case of success we end up with the full
832 * chain to new block and return 0.
834 static int ext4_splice_branch(handle_t *handle, struct inode *inode,
835 ext4_lblk_t block, Indirect *where, int num,
840 ext4_fsblk_t current_block;
843 * If we're splicing into a [td]indirect block (as opposed to the
844 * inode) then we need to get write access to the [td]indirect block
848 BUFFER_TRACE(where->bh, "get_write_access");
849 err = ext4_journal_get_write_access(handle, where->bh);
855 *where->p = where->key;
858 * Update the host buffer_head or inode to point to more just allocated
859 * direct blocks blocks
861 if (num == 0 && blks > 1) {
862 current_block = le32_to_cpu(where->key) + 1;
863 for (i = 1; i < blks; i++)
864 *(where->p + i) = cpu_to_le32(current_block++);
867 /* We are done with atomic stuff, now do the rest of housekeeping */
868 /* had we spliced it onto indirect block? */
871 * If we spliced it onto an indirect block, we haven't
872 * altered the inode. Note however that if it is being spliced
873 * onto an indirect block at the very end of the file (the
874 * file is growing) then we *will* alter the inode to reflect
875 * the new i_size. But that is not done here - it is done in
876 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
878 jbd_debug(5, "splicing indirect only\n");
879 BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
880 err = ext4_handle_dirty_metadata(handle, inode, where->bh);
885 * OK, we spliced it into the inode itself on a direct block.
887 ext4_mark_inode_dirty(handle, inode);
888 jbd_debug(5, "splicing direct\n");
893 for (i = 1; i <= num; i++) {
895 * branch[i].bh is newly allocated, so there is no
896 * need to revoke the block, which is why we don't
897 * need to set EXT4_FREE_BLOCKS_METADATA.
899 ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
900 EXT4_FREE_BLOCKS_FORGET);
902 ext4_free_blocks(handle, inode, 0, le32_to_cpu(where[num].key),
909 * The ext4_ind_map_blocks() function handles non-extents inodes
910 * (i.e., using the traditional indirect/double-indirect i_blocks
911 * scheme) for ext4_map_blocks().
913 * Allocation strategy is simple: if we have to allocate something, we will
914 * have to go the whole way to leaf. So let's do it before attaching anything
915 * to tree, set linkage between the newborn blocks, write them if sync is
916 * required, recheck the path, free and repeat if check fails, otherwise
917 * set the last missing link (that will protect us from any truncate-generated
918 * removals - all blocks on the path are immune now) and possibly force the
919 * write on the parent block.
920 * That has a nice additional property: no special recovery from the failed
921 * allocations is needed - we simply release blocks and do not touch anything
922 * reachable from inode.
924 * `handle' can be NULL if create == 0.
926 * return > 0, # of blocks mapped or allocated.
927 * return = 0, if plain lookup failed.
928 * return < 0, error case.
930 * The ext4_ind_get_blocks() function should be called with
931 * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
932 * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
933 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
936 static int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
937 struct ext4_map_blocks *map,
941 ext4_lblk_t offsets[4];
946 int blocks_to_boundary = 0;
949 ext4_fsblk_t first_block = 0;
951 J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
952 J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
953 depth = ext4_block_to_path(inode, map->m_lblk, offsets,
954 &blocks_to_boundary);
959 partial = ext4_get_branch(inode, depth, offsets, chain, &err);
961 /* Simplest case - block found, no allocation needed */
963 first_block = le32_to_cpu(chain[depth - 1].key);
966 while (count < map->m_len && count <= blocks_to_boundary) {
969 blk = le32_to_cpu(*(chain[depth-1].p + count));
971 if (blk == first_block + count)
979 /* Next simple case - plain lookup or failed read of indirect block */
980 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
984 * Okay, we need to do block allocation.
986 goal = ext4_find_goal(inode, map->m_lblk, partial);
988 /* the number of blocks need to allocate for [d,t]indirect blocks */
989 indirect_blks = (chain + depth) - partial - 1;
992 * Next look up the indirect map to count the totoal number of
993 * direct blocks to allocate for this branch.
995 count = ext4_blks_to_allocate(partial, indirect_blks,
996 map->m_len, blocks_to_boundary);
998 * Block out ext4_truncate while we alter the tree
1000 err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks,
1002 offsets + (partial - chain), partial);
1005 * The ext4_splice_branch call will free and forget any buffers
1006 * on the new chain if there is a failure, but that risks using
1007 * up transaction credits, especially for bitmaps where the
1008 * credits cannot be returned. Can we handle this somehow? We
1009 * may need to return -EAGAIN upwards in the worst case. --sct
1012 err = ext4_splice_branch(handle, inode, map->m_lblk,
1013 partial, indirect_blks, count);
1017 map->m_flags |= EXT4_MAP_NEW;
1019 ext4_update_inode_fsync_trans(handle, inode, 1);
1021 map->m_flags |= EXT4_MAP_MAPPED;
1022 map->m_pblk = le32_to_cpu(chain[depth-1].key);
1024 if (count > blocks_to_boundary)
1025 map->m_flags |= EXT4_MAP_BOUNDARY;
1027 /* Clean up and exit */
1028 partial = chain + depth - 1; /* the whole chain */
1030 while (partial > chain) {
1031 BUFFER_TRACE(partial->bh, "call brelse");
1032 brelse(partial->bh);
1040 qsize_t *ext4_get_reserved_space(struct inode *inode)
1042 return &EXT4_I(inode)->i_reserved_quota;
1047 * Calculate the number of metadata blocks need to reserve
1048 * to allocate a new block at @lblocks for non extent file based file
1050 static int ext4_indirect_calc_metadata_amount(struct inode *inode,
1053 struct ext4_inode_info *ei = EXT4_I(inode);
1054 sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1);
1057 if (lblock < EXT4_NDIR_BLOCKS)
1060 lblock -= EXT4_NDIR_BLOCKS;
1062 if (ei->i_da_metadata_calc_len &&
1063 (lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) {
1064 ei->i_da_metadata_calc_len++;
1067 ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
1068 ei->i_da_metadata_calc_len = 1;
1069 blk_bits = order_base_2(lblock);
1070 return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
1074 * Calculate the number of metadata blocks need to reserve
1075 * to allocate a block located at @lblock
1077 static int ext4_calc_metadata_amount(struct inode *inode, sector_t lblock)
1079 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1080 return ext4_ext_calc_metadata_amount(inode, lblock);
1082 return ext4_indirect_calc_metadata_amount(inode, lblock);
1086 * Called with i_data_sem down, which is important since we can call
1087 * ext4_discard_preallocations() from here.
1089 void ext4_da_update_reserve_space(struct inode *inode,
1090 int used, int quota_claim)
1092 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1093 struct ext4_inode_info *ei = EXT4_I(inode);
1095 spin_lock(&ei->i_block_reservation_lock);
1096 trace_ext4_da_update_reserve_space(inode, used);
1097 if (unlikely(used > ei->i_reserved_data_blocks)) {
1098 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d "
1099 "with only %d reserved data blocks\n",
1100 __func__, inode->i_ino, used,
1101 ei->i_reserved_data_blocks);
1103 used = ei->i_reserved_data_blocks;
1106 /* Update per-inode reservations */
1107 ei->i_reserved_data_blocks -= used;
1108 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
1109 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1110 used + ei->i_allocated_meta_blocks);
1111 ei->i_allocated_meta_blocks = 0;
1113 if (ei->i_reserved_data_blocks == 0) {
1115 * We can release all of the reserved metadata blocks
1116 * only when we have written all of the delayed
1117 * allocation blocks.
1119 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1120 ei->i_reserved_meta_blocks);
1121 ei->i_reserved_meta_blocks = 0;
1122 ei->i_da_metadata_calc_len = 0;
1124 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1126 /* Update quota subsystem for data blocks */
1128 dquot_claim_block(inode, used);
1131 * We did fallocate with an offset that is already delayed
1132 * allocated. So on delayed allocated writeback we should
1133 * not re-claim the quota for fallocated blocks.
1135 dquot_release_reservation_block(inode, used);
1139 * If we have done all the pending block allocations and if
1140 * there aren't any writers on the inode, we can discard the
1141 * inode's preallocations.
1143 if ((ei->i_reserved_data_blocks == 0) &&
1144 (atomic_read(&inode->i_writecount) == 0))
1145 ext4_discard_preallocations(inode);
1148 static int __check_block_validity(struct inode *inode, const char *func,
1150 struct ext4_map_blocks *map)
1152 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
1154 ext4_error_inode(inode, func, line, map->m_pblk,
1155 "lblock %lu mapped to illegal pblock "
1156 "(length %d)", (unsigned long) map->m_lblk,
1163 #define check_block_validity(inode, map) \
1164 __check_block_validity((inode), __func__, __LINE__, (map))
1167 * Return the number of contiguous dirty pages in a given inode
1168 * starting at page frame idx.
1170 static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
1171 unsigned int max_pages)
1173 struct address_space *mapping = inode->i_mapping;
1175 struct pagevec pvec;
1177 int i, nr_pages, done = 0;
1181 pagevec_init(&pvec, 0);
1184 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1185 PAGECACHE_TAG_DIRTY,
1186 (pgoff_t)PAGEVEC_SIZE);
1189 for (i = 0; i < nr_pages; i++) {
1190 struct page *page = pvec.pages[i];
1191 struct buffer_head *bh, *head;
1194 if (unlikely(page->mapping != mapping) ||
1196 PageWriteback(page) ||
1197 page->index != idx) {
1202 if (page_has_buffers(page)) {
1203 bh = head = page_buffers(page);
1205 if (!buffer_delay(bh) &&
1206 !buffer_unwritten(bh))
1208 bh = bh->b_this_page;
1209 } while (!done && (bh != head));
1216 if (num >= max_pages) {
1221 pagevec_release(&pvec);
1227 * The ext4_map_blocks() function tries to look up the requested blocks,
1228 * and returns if the blocks are already mapped.
1230 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
1231 * and store the allocated blocks in the result buffer head and mark it
1234 * If file type is extents based, it will call ext4_ext_map_blocks(),
1235 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
1238 * On success, it returns the number of blocks being mapped or allocate.
1239 * if create==0 and the blocks are pre-allocated and uninitialized block,
1240 * the result buffer head is unmapped. If the create ==1, it will make sure
1241 * the buffer head is mapped.
1243 * It returns 0 if plain look up failed (blocks have not been allocated), in
1244 * that casem, buffer head is unmapped
1246 * It returns the error in case of allocation failure.
1248 int ext4_map_blocks(handle_t *handle, struct inode *inode,
1249 struct ext4_map_blocks *map, int flags)
1254 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
1255 "logical block %lu\n", inode->i_ino, flags, map->m_len,
1256 (unsigned long) map->m_lblk);
1258 * Try to see if we can get the block without requesting a new
1259 * file system block.
1261 down_read((&EXT4_I(inode)->i_data_sem));
1262 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
1263 retval = ext4_ext_map_blocks(handle, inode, map, 0);
1265 retval = ext4_ind_map_blocks(handle, inode, map, 0);
1267 up_read((&EXT4_I(inode)->i_data_sem));
1269 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
1270 int ret = check_block_validity(inode, map);
1275 /* If it is only a block(s) look up */
1276 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
1280 * Returns if the blocks have already allocated
1282 * Note that if blocks have been preallocated
1283 * ext4_ext_get_block() returns th create = 0
1284 * with buffer head unmapped.
1286 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
1290 * When we call get_blocks without the create flag, the
1291 * BH_Unwritten flag could have gotten set if the blocks
1292 * requested were part of a uninitialized extent. We need to
1293 * clear this flag now that we are committed to convert all or
1294 * part of the uninitialized extent to be an initialized
1295 * extent. This is because we need to avoid the combination
1296 * of BH_Unwritten and BH_Mapped flags being simultaneously
1297 * set on the buffer_head.
1299 map->m_flags &= ~EXT4_MAP_UNWRITTEN;
1302 * New blocks allocate and/or writing to uninitialized extent
1303 * will possibly result in updating i_data, so we take
1304 * the write lock of i_data_sem, and call get_blocks()
1305 * with create == 1 flag.
1307 down_write((&EXT4_I(inode)->i_data_sem));
1310 * if the caller is from delayed allocation writeout path
1311 * we have already reserved fs blocks for allocation
1312 * let the underlying get_block() function know to
1313 * avoid double accounting
1315 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1316 EXT4_I(inode)->i_delalloc_reserved_flag = 1;
1318 * We need to check for EXT4 here because migrate
1319 * could have changed the inode type in between
1321 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
1322 retval = ext4_ext_map_blocks(handle, inode, map, flags);
1324 retval = ext4_ind_map_blocks(handle, inode, map, flags);
1326 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
1328 * We allocated new blocks which will result in
1329 * i_data's format changing. Force the migrate
1330 * to fail by clearing migrate flags
1332 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
1336 * Update reserved blocks/metadata blocks after successful
1337 * block allocation which had been deferred till now. We don't
1338 * support fallocate for non extent files. So we can update
1339 * reserve space here.
1342 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
1343 ext4_da_update_reserve_space(inode, retval, 1);
1345 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1346 EXT4_I(inode)->i_delalloc_reserved_flag = 0;
1348 up_write((&EXT4_I(inode)->i_data_sem));
1349 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
1350 int ret = check_block_validity(inode, map);
1357 /* Maximum number of blocks we map for direct IO at once. */
1358 #define DIO_MAX_BLOCKS 4096
1360 static int _ext4_get_block(struct inode *inode, sector_t iblock,
1361 struct buffer_head *bh, int flags)
1363 handle_t *handle = ext4_journal_current_handle();
1364 struct ext4_map_blocks map;
1365 int ret = 0, started = 0;
1368 map.m_lblk = iblock;
1369 map.m_len = bh->b_size >> inode->i_blkbits;
1371 if (flags && !handle) {
1372 /* Direct IO write... */
1373 if (map.m_len > DIO_MAX_BLOCKS)
1374 map.m_len = DIO_MAX_BLOCKS;
1375 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
1376 handle = ext4_journal_start(inode, dio_credits);
1377 if (IS_ERR(handle)) {
1378 ret = PTR_ERR(handle);
1384 ret = ext4_map_blocks(handle, inode, &map, flags);
1386 map_bh(bh, inode->i_sb, map.m_pblk);
1387 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1388 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
1392 ext4_journal_stop(handle);
1396 int ext4_get_block(struct inode *inode, sector_t iblock,
1397 struct buffer_head *bh, int create)
1399 return _ext4_get_block(inode, iblock, bh,
1400 create ? EXT4_GET_BLOCKS_CREATE : 0);
1404 * `handle' can be NULL if create is zero
1406 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
1407 ext4_lblk_t block, int create, int *errp)
1409 struct ext4_map_blocks map;
1410 struct buffer_head *bh;
1413 J_ASSERT(handle != NULL || create == 0);
1417 err = ext4_map_blocks(handle, inode, &map,
1418 create ? EXT4_GET_BLOCKS_CREATE : 0);
1426 bh = sb_getblk(inode->i_sb, map.m_pblk);
1431 if (map.m_flags & EXT4_MAP_NEW) {
1432 J_ASSERT(create != 0);
1433 J_ASSERT(handle != NULL);
1436 * Now that we do not always journal data, we should
1437 * keep in mind whether this should always journal the
1438 * new buffer as metadata. For now, regular file
1439 * writes use ext4_get_block instead, so it's not a
1443 BUFFER_TRACE(bh, "call get_create_access");
1444 fatal = ext4_journal_get_create_access(handle, bh);
1445 if (!fatal && !buffer_uptodate(bh)) {
1446 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
1447 set_buffer_uptodate(bh);
1450 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1451 err = ext4_handle_dirty_metadata(handle, inode, bh);
1455 BUFFER_TRACE(bh, "not a new buffer");
1465 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
1466 ext4_lblk_t block, int create, int *err)
1468 struct buffer_head *bh;
1470 bh = ext4_getblk(handle, inode, block, create, err);
1473 if (buffer_uptodate(bh))
1475 ll_rw_block(READ_META, 1, &bh);
1477 if (buffer_uptodate(bh))
1484 static int walk_page_buffers(handle_t *handle,
1485 struct buffer_head *head,
1489 int (*fn)(handle_t *handle,
1490 struct buffer_head *bh))
1492 struct buffer_head *bh;
1493 unsigned block_start, block_end;
1494 unsigned blocksize = head->b_size;
1496 struct buffer_head *next;
1498 for (bh = head, block_start = 0;
1499 ret == 0 && (bh != head || !block_start);
1500 block_start = block_end, bh = next) {
1501 next = bh->b_this_page;
1502 block_end = block_start + blocksize;
1503 if (block_end <= from || block_start >= to) {
1504 if (partial && !buffer_uptodate(bh))
1508 err = (*fn)(handle, bh);
1516 * To preserve ordering, it is essential that the hole instantiation and
1517 * the data write be encapsulated in a single transaction. We cannot
1518 * close off a transaction and start a new one between the ext4_get_block()
1519 * and the commit_write(). So doing the jbd2_journal_start at the start of
1520 * prepare_write() is the right place.
1522 * Also, this function can nest inside ext4_writepage() ->
1523 * block_write_full_page(). In that case, we *know* that ext4_writepage()
1524 * has generated enough buffer credits to do the whole page. So we won't
1525 * block on the journal in that case, which is good, because the caller may
1528 * By accident, ext4 can be reentered when a transaction is open via
1529 * quota file writes. If we were to commit the transaction while thus
1530 * reentered, there can be a deadlock - we would be holding a quota
1531 * lock, and the commit would never complete if another thread had a
1532 * transaction open and was blocking on the quota lock - a ranking
1535 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1536 * will _not_ run commit under these circumstances because handle->h_ref
1537 * is elevated. We'll still have enough credits for the tiny quotafile
1540 static int do_journal_get_write_access(handle_t *handle,
1541 struct buffer_head *bh)
1543 int dirty = buffer_dirty(bh);
1546 if (!buffer_mapped(bh) || buffer_freed(bh))
1549 * __block_prepare_write() could have dirtied some buffers. Clean
1550 * the dirty bit as jbd2_journal_get_write_access() could complain
1551 * otherwise about fs integrity issues. Setting of the dirty bit
1552 * by __block_prepare_write() isn't a real problem here as we clear
1553 * the bit before releasing a page lock and thus writeback cannot
1554 * ever write the buffer.
1557 clear_buffer_dirty(bh);
1558 ret = ext4_journal_get_write_access(handle, bh);
1560 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1565 * Truncate blocks that were not used by write. We have to truncate the
1566 * pagecache as well so that corresponding buffers get properly unmapped.
1568 static void ext4_truncate_failed_write(struct inode *inode)
1570 truncate_inode_pages(inode->i_mapping, inode->i_size);
1571 ext4_truncate(inode);
1574 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
1575 struct buffer_head *bh_result, int create);
1576 static int ext4_write_begin(struct file *file, struct address_space *mapping,
1577 loff_t pos, unsigned len, unsigned flags,
1578 struct page **pagep, void **fsdata)
1580 struct inode *inode = mapping->host;
1581 int ret, needed_blocks;
1588 trace_ext4_write_begin(inode, pos, len, flags);
1590 * Reserve one block more for addition to orphan list in case
1591 * we allocate blocks but write fails for some reason
1593 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
1594 index = pos >> PAGE_CACHE_SHIFT;
1595 from = pos & (PAGE_CACHE_SIZE - 1);
1599 handle = ext4_journal_start(inode, needed_blocks);
1600 if (IS_ERR(handle)) {
1601 ret = PTR_ERR(handle);
1605 /* We cannot recurse into the filesystem as the transaction is already
1607 flags |= AOP_FLAG_NOFS;
1609 page = grab_cache_page_write_begin(mapping, index, flags);
1611 ext4_journal_stop(handle);
1617 if (ext4_should_dioread_nolock(inode))
1618 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
1620 ret = __block_write_begin(page, pos, len, ext4_get_block);
1622 if (!ret && ext4_should_journal_data(inode)) {
1623 ret = walk_page_buffers(handle, page_buffers(page),
1624 from, to, NULL, do_journal_get_write_access);
1629 page_cache_release(page);
1631 * __block_write_begin may have instantiated a few blocks
1632 * outside i_size. Trim these off again. Don't need
1633 * i_size_read because we hold i_mutex.
1635 * Add inode to orphan list in case we crash before
1638 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1639 ext4_orphan_add(handle, inode);
1641 ext4_journal_stop(handle);
1642 if (pos + len > inode->i_size) {
1643 ext4_truncate_failed_write(inode);
1645 * If truncate failed early the inode might
1646 * still be on the orphan list; we need to
1647 * make sure the inode is removed from the
1648 * orphan list in that case.
1651 ext4_orphan_del(NULL, inode);
1655 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1661 /* For write_end() in data=journal mode */
1662 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1664 if (!buffer_mapped(bh) || buffer_freed(bh))
1666 set_buffer_uptodate(bh);
1667 return ext4_handle_dirty_metadata(handle, NULL, bh);
1670 static int ext4_generic_write_end(struct file *file,
1671 struct address_space *mapping,
1672 loff_t pos, unsigned len, unsigned copied,
1673 struct page *page, void *fsdata)
1675 int i_size_changed = 0;
1676 struct inode *inode = mapping->host;
1677 handle_t *handle = ext4_journal_current_handle();
1679 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1682 * No need to use i_size_read() here, the i_size
1683 * cannot change under us because we hold i_mutex.
1685 * But it's important to update i_size while still holding page lock:
1686 * page writeout could otherwise come in and zero beyond i_size.
1688 if (pos + copied > inode->i_size) {
1689 i_size_write(inode, pos + copied);
1693 if (pos + copied > EXT4_I(inode)->i_disksize) {
1694 /* We need to mark inode dirty even if
1695 * new_i_size is less that inode->i_size
1696 * bu greater than i_disksize.(hint delalloc)
1698 ext4_update_i_disksize(inode, (pos + copied));
1702 page_cache_release(page);
1705 * Don't mark the inode dirty under page lock. First, it unnecessarily
1706 * makes the holding time of page lock longer. Second, it forces lock
1707 * ordering of page lock and transaction start for journaling
1711 ext4_mark_inode_dirty(handle, inode);
1717 * We need to pick up the new inode size which generic_commit_write gave us
1718 * `file' can be NULL - eg, when called from page_symlink().
1720 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1721 * buffers are managed internally.
1723 static int ext4_ordered_write_end(struct file *file,
1724 struct address_space *mapping,
1725 loff_t pos, unsigned len, unsigned copied,
1726 struct page *page, void *fsdata)
1728 handle_t *handle = ext4_journal_current_handle();
1729 struct inode *inode = mapping->host;
1732 trace_ext4_ordered_write_end(inode, pos, len, copied);
1733 ret = ext4_jbd2_file_inode(handle, inode);
1736 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1739 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1740 /* if we have allocated more blocks and copied
1741 * less. We will have blocks allocated outside
1742 * inode->i_size. So truncate them
1744 ext4_orphan_add(handle, inode);
1748 ret2 = ext4_journal_stop(handle);
1752 if (pos + len > inode->i_size) {
1753 ext4_truncate_failed_write(inode);
1755 * If truncate failed early the inode might still be
1756 * on the orphan list; we need to make sure the inode
1757 * is removed from the orphan list in that case.
1760 ext4_orphan_del(NULL, inode);
1764 return ret ? ret : copied;
1767 static int ext4_writeback_write_end(struct file *file,
1768 struct address_space *mapping,
1769 loff_t pos, unsigned len, unsigned copied,
1770 struct page *page, void *fsdata)
1772 handle_t *handle = ext4_journal_current_handle();
1773 struct inode *inode = mapping->host;
1776 trace_ext4_writeback_write_end(inode, pos, len, copied);
1777 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
1780 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1781 /* if we have allocated more blocks and copied
1782 * less. We will have blocks allocated outside
1783 * inode->i_size. So truncate them
1785 ext4_orphan_add(handle, inode);
1790 ret2 = ext4_journal_stop(handle);
1794 if (pos + len > inode->i_size) {
1795 ext4_truncate_failed_write(inode);
1797 * If truncate failed early the inode might still be
1798 * on the orphan list; we need to make sure the inode
1799 * is removed from the orphan list in that case.
1802 ext4_orphan_del(NULL, inode);
1805 return ret ? ret : copied;
1808 static int ext4_journalled_write_end(struct file *file,
1809 struct address_space *mapping,
1810 loff_t pos, unsigned len, unsigned copied,
1811 struct page *page, void *fsdata)
1813 handle_t *handle = ext4_journal_current_handle();
1814 struct inode *inode = mapping->host;
1820 trace_ext4_journalled_write_end(inode, pos, len, copied);
1821 from = pos & (PAGE_CACHE_SIZE - 1);
1825 if (!PageUptodate(page))
1827 page_zero_new_buffers(page, from+copied, to);
1830 ret = walk_page_buffers(handle, page_buffers(page), from,
1831 to, &partial, write_end_fn);
1833 SetPageUptodate(page);
1834 new_i_size = pos + copied;
1835 if (new_i_size > inode->i_size)
1836 i_size_write(inode, pos+copied);
1837 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1838 if (new_i_size > EXT4_I(inode)->i_disksize) {
1839 ext4_update_i_disksize(inode, new_i_size);
1840 ret2 = ext4_mark_inode_dirty(handle, inode);
1846 page_cache_release(page);
1847 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1848 /* if we have allocated more blocks and copied
1849 * less. We will have blocks allocated outside
1850 * inode->i_size. So truncate them
1852 ext4_orphan_add(handle, inode);
1854 ret2 = ext4_journal_stop(handle);
1857 if (pos + len > inode->i_size) {
1858 ext4_truncate_failed_write(inode);
1860 * If truncate failed early the inode might still be
1861 * on the orphan list; we need to make sure the inode
1862 * is removed from the orphan list in that case.
1865 ext4_orphan_del(NULL, inode);
1868 return ret ? ret : copied;
1872 * Reserve a single block located at lblock
1874 static int ext4_da_reserve_space(struct inode *inode, sector_t lblock)
1877 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1878 struct ext4_inode_info *ei = EXT4_I(inode);
1879 unsigned long md_needed;
1883 * recalculate the amount of metadata blocks to reserve
1884 * in order to allocate nrblocks
1885 * worse case is one extent per block
1888 spin_lock(&ei->i_block_reservation_lock);
1889 md_needed = ext4_calc_metadata_amount(inode, lblock);
1890 trace_ext4_da_reserve_space(inode, md_needed);
1891 spin_unlock(&ei->i_block_reservation_lock);
1894 * We will charge metadata quota at writeout time; this saves
1895 * us from metadata over-estimation, though we may go over by
1896 * a small amount in the end. Here we just reserve for data.
1898 ret = dquot_reserve_block(inode, 1);
1902 * We do still charge estimated metadata to the sb though;
1903 * we cannot afford to run out of free blocks.
1905 if (ext4_claim_free_blocks(sbi, md_needed + 1)) {
1906 dquot_release_reservation_block(inode, 1);
1907 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1913 spin_lock(&ei->i_block_reservation_lock);
1914 ei->i_reserved_data_blocks++;
1915 ei->i_reserved_meta_blocks += md_needed;
1916 spin_unlock(&ei->i_block_reservation_lock);
1918 return 0; /* success */
1921 static void ext4_da_release_space(struct inode *inode, int to_free)
1923 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1924 struct ext4_inode_info *ei = EXT4_I(inode);
1927 return; /* Nothing to release, exit */
1929 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1931 trace_ext4_da_release_space(inode, to_free);
1932 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1934 * if there aren't enough reserved blocks, then the
1935 * counter is messed up somewhere. Since this
1936 * function is called from invalidate page, it's
1937 * harmless to return without any action.
1939 ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: "
1940 "ino %lu, to_free %d with only %d reserved "
1941 "data blocks\n", inode->i_ino, to_free,
1942 ei->i_reserved_data_blocks);
1944 to_free = ei->i_reserved_data_blocks;
1946 ei->i_reserved_data_blocks -= to_free;
1948 if (ei->i_reserved_data_blocks == 0) {
1950 * We can release all of the reserved metadata blocks
1951 * only when we have written all of the delayed
1952 * allocation blocks.
1954 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
1955 ei->i_reserved_meta_blocks);
1956 ei->i_reserved_meta_blocks = 0;
1957 ei->i_da_metadata_calc_len = 0;
1960 /* update fs dirty data blocks counter */
1961 percpu_counter_sub(&sbi->s_dirtyblocks_counter, to_free);
1963 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1965 dquot_release_reservation_block(inode, to_free);
1968 static void ext4_da_page_release_reservation(struct page *page,
1969 unsigned long offset)
1972 struct buffer_head *head, *bh;
1973 unsigned int curr_off = 0;
1975 head = page_buffers(page);
1978 unsigned int next_off = curr_off + bh->b_size;
1980 if ((offset <= curr_off) && (buffer_delay(bh))) {
1982 clear_buffer_delay(bh);
1984 curr_off = next_off;
1985 } while ((bh = bh->b_this_page) != head);
1986 ext4_da_release_space(page->mapping->host, to_release);
1990 * Delayed allocation stuff
1994 * mpage_da_submit_io - walks through extent of pages and try to write
1995 * them with writepage() call back
1997 * @mpd->inode: inode
1998 * @mpd->first_page: first page of the extent
1999 * @mpd->next_page: page after the last page of the extent
2001 * By the time mpage_da_submit_io() is called we expect all blocks
2002 * to be allocated. this may be wrong if allocation failed.
2004 * As pages are already locked by write_cache_pages(), we can't use it
2006 static int mpage_da_submit_io(struct mpage_da_data *mpd)
2008 struct pagevec pvec;
2009 unsigned long index, end;
2010 int ret = 0, err, nr_pages, i;
2011 struct inode *inode = mpd->inode;
2012 struct address_space *mapping = inode->i_mapping;
2013 loff_t size = i_size_read(inode);
2014 unsigned int len, block_start;
2015 struct buffer_head *bh, *page_bufs = NULL;
2016 int journal_data = ext4_should_journal_data(inode);
2018 BUG_ON(mpd->next_page <= mpd->first_page);
2020 * We need to start from the first_page to the next_page - 1
2021 * to make sure we also write the mapped dirty buffer_heads.
2022 * If we look at mpd->b_blocknr we would only be looking
2023 * at the currently mapped buffer_heads.
2025 index = mpd->first_page;
2026 end = mpd->next_page - 1;
2028 pagevec_init(&pvec, 0);
2029 while (index <= end) {
2030 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2033 for (i = 0; i < nr_pages; i++) {
2034 int commit_write = 0;
2035 struct page *page = pvec.pages[i];
2037 index = page->index;
2041 if (index == size >> PAGE_CACHE_SHIFT)
2042 len = size & ~PAGE_CACHE_MASK;
2044 len = PAGE_CACHE_SIZE;
2047 BUG_ON(!PageLocked(page));
2048 BUG_ON(PageWriteback(page));
2051 * If the page does not have buffers (for
2052 * whatever reason), try to create them using
2053 * block_prepare_write. If this fails,
2054 * redirty the page and move on.
2056 if (!page_has_buffers(page)) {
2057 if (block_prepare_write(page, 0, len,
2058 noalloc_get_block_write)) {
2060 redirty_page_for_writepage(mpd->wbc,
2068 bh = page_bufs = page_buffers(page);
2071 /* redirty page if block allocation undone */
2072 if (!bh || buffer_delay(bh) ||
2073 buffer_unwritten(bh))
2075 bh = bh->b_this_page;
2076 block_start += bh->b_size;
2077 } while ((bh != page_bufs) && (block_start < len));
2080 /* mark the buffer_heads as dirty & uptodate */
2081 block_commit_write(page, 0, len);
2083 if (journal_data && PageChecked(page))
2084 err = __ext4_journalled_writepage(page, len);
2085 else if (buffer_uninit(page_bufs)) {
2086 ext4_set_bh_endio(page_bufs, inode);
2087 err = block_write_full_page_endio(page,
2088 noalloc_get_block_write,
2089 mpd->wbc, ext4_end_io_buffer_write);
2091 err = block_write_full_page(page,
2092 noalloc_get_block_write, mpd->wbc);
2095 mpd->pages_written++;
2097 * In error case, we have to continue because
2098 * remaining pages are still locked
2103 pagevec_release(&pvec);
2109 * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
2111 * the function goes through all passed space and put actual disk
2112 * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
2114 static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd,
2115 struct ext4_map_blocks *map)
2117 struct inode *inode = mpd->inode;
2118 struct address_space *mapping = inode->i_mapping;
2119 int blocks = map->m_len;
2120 sector_t pblock = map->m_pblk, cur_logical;
2121 struct buffer_head *head, *bh;
2123 struct pagevec pvec;
2126 index = map->m_lblk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
2127 end = (map->m_lblk + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
2128 cur_logical = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
2130 pagevec_init(&pvec, 0);
2132 while (index <= end) {
2133 /* XXX: optimize tail */
2134 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2137 for (i = 0; i < nr_pages; i++) {
2138 struct page *page = pvec.pages[i];
2140 index = page->index;
2145 BUG_ON(!PageLocked(page));
2146 BUG_ON(PageWriteback(page));
2147 BUG_ON(!page_has_buffers(page));
2149 bh = page_buffers(page);
2152 /* skip blocks out of the range */
2154 if (cur_logical >= map->m_lblk)
2157 } while ((bh = bh->b_this_page) != head);
2160 if (cur_logical > map->m_lblk + (blocks - 1))
2163 if (buffer_delay(bh) || buffer_unwritten(bh)) {
2165 BUG_ON(bh->b_bdev != inode->i_sb->s_bdev);
2167 if (buffer_delay(bh)) {
2168 clear_buffer_delay(bh);
2169 bh->b_blocknr = pblock;
2172 * unwritten already should have
2173 * blocknr assigned. Verify that
2175 clear_buffer_unwritten(bh);
2176 BUG_ON(bh->b_blocknr != pblock);
2179 } else if (buffer_mapped(bh))
2180 BUG_ON(bh->b_blocknr != pblock);
2182 if (map->m_flags & EXT4_MAP_UNINIT)
2183 set_buffer_uninit(bh);
2186 } while ((bh = bh->b_this_page) != head);
2188 pagevec_release(&pvec);
2193 static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
2194 sector_t logical, long blk_cnt)
2198 struct pagevec pvec;
2199 struct inode *inode = mpd->inode;
2200 struct address_space *mapping = inode->i_mapping;
2202 index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
2203 end = (logical + blk_cnt - 1) >>
2204 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2205 while (index <= end) {
2206 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
2209 for (i = 0; i < nr_pages; i++) {
2210 struct page *page = pvec.pages[i];
2211 if (page->index > end)
2213 BUG_ON(!PageLocked(page));
2214 BUG_ON(PageWriteback(page));
2215 block_invalidatepage(page, 0);
2216 ClearPageUptodate(page);
2219 index = pvec.pages[nr_pages - 1]->index + 1;
2220 pagevec_release(&pvec);
2225 static void ext4_print_free_blocks(struct inode *inode)
2227 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2228 printk(KERN_CRIT "Total free blocks count %lld\n",
2229 ext4_count_free_blocks(inode->i_sb));
2230 printk(KERN_CRIT "Free/Dirty block details\n");
2231 printk(KERN_CRIT "free_blocks=%lld\n",
2232 (long long) percpu_counter_sum(&sbi->s_freeblocks_counter));
2233 printk(KERN_CRIT "dirty_blocks=%lld\n",
2234 (long long) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2235 printk(KERN_CRIT "Block reservation details\n");
2236 printk(KERN_CRIT "i_reserved_data_blocks=%u\n",
2237 EXT4_I(inode)->i_reserved_data_blocks);
2238 printk(KERN_CRIT "i_reserved_meta_blocks=%u\n",
2239 EXT4_I(inode)->i_reserved_meta_blocks);
2244 * mpage_da_map_and_submit - go through given space, map them
2245 * if necessary, and then submit them for I/O
2247 * @mpd - bh describing space
2249 * The function skips space we know is already mapped to disk blocks.
2252 static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
2254 int err, blks, get_blocks_flags;
2255 struct ext4_map_blocks map;
2256 sector_t next = mpd->b_blocknr;
2257 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
2258 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
2259 handle_t *handle = NULL;
2262 * If the blocks are mapped already, or we couldn't accumulate
2263 * any blocks, then proceed immediately to the submission stage.
2265 if ((mpd->b_size == 0) ||
2266 ((mpd->b_state & (1 << BH_Mapped)) &&
2267 !(mpd->b_state & (1 << BH_Delay)) &&
2268 !(mpd->b_state & (1 << BH_Unwritten))))
2271 handle = ext4_journal_current_handle();
2275 * Call ext4_map_blocks() to allocate any delayed allocation
2276 * blocks, or to convert an uninitialized extent to be
2277 * initialized (in the case where we have written into
2278 * one or more preallocated blocks).
2280 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
2281 * indicate that we are on the delayed allocation path. This
2282 * affects functions in many different parts of the allocation
2283 * call path. This flag exists primarily because we don't
2284 * want to change *many* call functions, so ext4_map_blocks()
2285 * will set the magic i_delalloc_reserved_flag once the
2286 * inode's allocation semaphore is taken.
2288 * If the blocks in questions were delalloc blocks, set
2289 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
2290 * variables are updated after the blocks have been allocated.
2293 map.m_len = max_blocks;
2294 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
2295 if (ext4_should_dioread_nolock(mpd->inode))
2296 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
2297 if (mpd->b_state & (1 << BH_Delay))
2298 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
2300 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
2302 struct super_block *sb = mpd->inode->i_sb;
2306 * If get block returns EAGAIN or ENOSPC and there
2307 * appears to be free blocks we will call
2308 * ext4_writepage() for all of the pages which will
2309 * just redirty the pages.
2314 if (err == -ENOSPC &&
2315 ext4_count_free_blocks(sb)) {
2321 * get block failure will cause us to loop in
2322 * writepages, because a_ops->writepage won't be able
2323 * to make progress. The page will be redirtied by
2324 * writepage and writepages will again try to write
2327 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
2328 ext4_msg(sb, KERN_CRIT,
2329 "delayed block allocation failed for inode %lu "
2330 "at logical offset %llu with max blocks %zd "
2331 "with error %d", mpd->inode->i_ino,
2332 (unsigned long long) next,
2333 mpd->b_size >> mpd->inode->i_blkbits, err);
2334 ext4_msg(sb, KERN_CRIT,
2335 "This should not happen!! Data will be lost\n");
2337 ext4_print_free_blocks(mpd->inode);
2339 /* invalidate all the pages */
2340 ext4_da_block_invalidatepages(mpd, next,
2341 mpd->b_size >> mpd->inode->i_blkbits);
2346 if (map.m_flags & EXT4_MAP_NEW) {
2347 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
2350 for (i = 0; i < map.m_len; i++)
2351 unmap_underlying_metadata(bdev, map.m_pblk + i);
2355 * If blocks are delayed marked, we need to
2356 * put actual blocknr and drop delayed bit
2358 if ((mpd->b_state & (1 << BH_Delay)) ||
2359 (mpd->b_state & (1 << BH_Unwritten)))
2360 mpage_put_bnr_to_bhs(mpd, &map);
2362 if (ext4_should_order_data(mpd->inode)) {
2363 err = ext4_jbd2_file_inode(handle, mpd->inode);
2365 /* This only happens if the journal is aborted */
2370 * Update on-disk size along with block allocation.
2372 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
2373 if (disksize > i_size_read(mpd->inode))
2374 disksize = i_size_read(mpd->inode);
2375 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
2376 ext4_update_i_disksize(mpd->inode, disksize);
2377 err = ext4_mark_inode_dirty(handle, mpd->inode);
2379 ext4_error(mpd->inode->i_sb,
2380 "Failed to mark inode %lu dirty",
2385 mpage_da_submit_io(mpd);
2389 #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
2390 (1 << BH_Delay) | (1 << BH_Unwritten))
2393 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
2395 * @mpd->lbh - extent of blocks
2396 * @logical - logical number of the block in the file
2397 * @bh - bh of the block (used to access block's state)
2399 * the function is used to collect contig. blocks in same state
2401 static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
2402 sector_t logical, size_t b_size,
2403 unsigned long b_state)
2406 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
2409 * XXX Don't go larger than mballoc is willing to allocate
2410 * This is a stopgap solution. We eventually need to fold
2411 * mpage_da_submit_io() into this function and then call
2412 * ext4_map_blocks() multiple times in a loop
2414 if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize)
2417 /* check if thereserved journal credits might overflow */
2418 if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) {
2419 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
2421 * With non-extent format we are limited by the journal
2422 * credit available. Total credit needed to insert
2423 * nrblocks contiguous blocks is dependent on the
2424 * nrblocks. So limit nrblocks.
2427 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
2428 EXT4_MAX_TRANS_DATA) {
2430 * Adding the new buffer_head would make it cross the
2431 * allowed limit for which we have journal credit
2432 * reserved. So limit the new bh->b_size
2434 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
2435 mpd->inode->i_blkbits;
2436 /* we will do mpage_da_submit_io in the next loop */
2440 * First block in the extent
2442 if (mpd->b_size == 0) {
2443 mpd->b_blocknr = logical;
2444 mpd->b_size = b_size;
2445 mpd->b_state = b_state & BH_FLAGS;
2449 next = mpd->b_blocknr + nrblocks;
2451 * Can we merge the block to our big extent?
2453 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
2454 mpd->b_size += b_size;
2460 * We couldn't merge the block to our extent, so we
2461 * need to flush current extent and start new one
2463 mpage_da_map_and_submit(mpd);
2467 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
2469 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
2473 * __mpage_da_writepage - finds extent of pages and blocks
2475 * @page: page to consider
2476 * @wbc: not used, we just follow rules
2479 * The function finds extents of pages and scan them for all blocks.
2481 static int __mpage_da_writepage(struct page *page,
2482 struct writeback_control *wbc, void *data)
2484 struct mpage_da_data *mpd = data;
2485 struct inode *inode = mpd->inode;
2486 struct buffer_head *bh, *head;
2490 * Can we merge this page to current extent?
2492 if (mpd->next_page != page->index) {
2494 * Nope, we can't. So, we map non-allocated blocks
2495 * and start IO on them
2497 if (mpd->next_page != mpd->first_page) {
2498 mpage_da_map_and_submit(mpd);
2500 * skip rest of the page in the page_vec
2502 redirty_page_for_writepage(wbc, page);
2504 return MPAGE_DA_EXTENT_TAIL;
2508 * Start next extent of pages ...
2510 mpd->first_page = page->index;
2520 mpd->next_page = page->index + 1;
2521 logical = (sector_t) page->index <<
2522 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2524 if (!page_has_buffers(page)) {
2525 mpage_add_bh_to_extent(mpd, logical, PAGE_CACHE_SIZE,
2526 (1 << BH_Dirty) | (1 << BH_Uptodate));
2528 return MPAGE_DA_EXTENT_TAIL;
2531 * Page with regular buffer heads, just add all dirty ones
2533 head = page_buffers(page);
2536 BUG_ON(buffer_locked(bh));
2538 * We need to try to allocate
2539 * unmapped blocks in the same page.
2540 * Otherwise we won't make progress
2541 * with the page in ext4_writepage
2543 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2544 mpage_add_bh_to_extent(mpd, logical,
2548 return MPAGE_DA_EXTENT_TAIL;
2549 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2551 * mapped dirty buffer. We need to update
2552 * the b_state because we look at
2553 * b_state in mpage_da_map_blocks. We don't
2554 * update b_size because if we find an
2555 * unmapped buffer_head later we need to
2556 * use the b_state flag of that buffer_head.
2558 if (mpd->b_size == 0)
2559 mpd->b_state = bh->b_state & BH_FLAGS;
2562 } while ((bh = bh->b_this_page) != head);
2569 * This is a special get_blocks_t callback which is used by
2570 * ext4_da_write_begin(). It will either return mapped block or
2571 * reserve space for a single block.
2573 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
2574 * We also have b_blocknr = -1 and b_bdev initialized properly
2576 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
2577 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
2578 * initialized properly.
2580 static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2581 struct buffer_head *bh, int create)
2583 struct ext4_map_blocks map;
2585 sector_t invalid_block = ~((sector_t) 0xffff);
2587 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
2590 BUG_ON(create == 0);
2591 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
2593 map.m_lblk = iblock;
2597 * first, we need to know whether the block is allocated already
2598 * preallocated blocks are unmapped but should treated
2599 * the same as allocated blocks.
2601 ret = ext4_map_blocks(NULL, inode, &map, 0);
2605 if (buffer_delay(bh))
2606 return 0; /* Not sure this could or should happen */
2608 * XXX: __block_prepare_write() unmaps passed block,
2611 ret = ext4_da_reserve_space(inode, iblock);
2613 /* not enough space to reserve */
2616 map_bh(bh, inode->i_sb, invalid_block);
2618 set_buffer_delay(bh);
2622 map_bh(bh, inode->i_sb, map.m_pblk);
2623 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
2625 if (buffer_unwritten(bh)) {
2626 /* A delayed write to unwritten bh should be marked
2627 * new and mapped. Mapped ensures that we don't do
2628 * get_block multiple times when we write to the same
2629 * offset and new ensures that we do proper zero out
2630 * for partial write.
2633 set_buffer_mapped(bh);
2639 * This function is used as a standard get_block_t calback function
2640 * when there is no desire to allocate any blocks. It is used as a
2641 * callback function for block_prepare_write() and block_write_full_page().
2642 * These functions should only try to map a single block at a time.
2644 * Since this function doesn't do block allocations even if the caller
2645 * requests it by passing in create=1, it is critically important that
2646 * any caller checks to make sure that any buffer heads are returned
2647 * by this function are either all already mapped or marked for
2648 * delayed allocation before calling block_write_full_page(). Otherwise,
2649 * b_blocknr could be left unitialized, and the page write functions will
2650 * be taken by surprise.
2652 static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
2653 struct buffer_head *bh_result, int create)
2655 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
2656 return _ext4_get_block(inode, iblock, bh_result, 0);
2659 static int bget_one(handle_t *handle, struct buffer_head *bh)
2665 static int bput_one(handle_t *handle, struct buffer_head *bh)
2671 static int __ext4_journalled_writepage(struct page *page,
2674 struct address_space *mapping = page->mapping;
2675 struct inode *inode = mapping->host;
2676 struct buffer_head *page_bufs;
2677 handle_t *handle = NULL;
2681 ClearPageChecked(page);
2682 page_bufs = page_buffers(page);
2684 walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
2685 /* As soon as we unlock the page, it can go away, but we have
2686 * references to buffers so we are safe */
2689 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
2690 if (IS_ERR(handle)) {
2691 ret = PTR_ERR(handle);
2695 ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2696 do_journal_get_write_access);
2698 err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
2702 err = ext4_journal_stop(handle);
2706 walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
2707 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
2712 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
2713 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
2716 * Note that we don't need to start a transaction unless we're journaling data
2717 * because we should have holes filled from ext4_page_mkwrite(). We even don't
2718 * need to file the inode to the transaction's list in ordered mode because if
2719 * we are writing back data added by write(), the inode is already there and if
2720 * we are writing back data modified via mmap(), noone guarantees in which
2721 * transaction the data will hit the disk. In case we are journaling data, we
2722 * cannot start transaction directly because transaction start ranks above page
2723 * lock so we have to do some magic.
2725 * This function can get called via...
2726 * - ext4_da_writepages after taking page lock (have journal handle)
2727 * - journal_submit_inode_data_buffers (no journal handle)
2728 * - shrink_page_list via pdflush (no journal handle)
2729 * - grab_page_cache when doing write_begin (have journal handle)
2731 * We don't do any block allocation in this function. If we have page with
2732 * multiple blocks we need to write those buffer_heads that are mapped. This
2733 * is important for mmaped based write. So if we do with blocksize 1K
2734 * truncate(f, 1024);
2735 * a = mmap(f, 0, 4096);
2737 * truncate(f, 4096);
2738 * we have in the page first buffer_head mapped via page_mkwrite call back
2739 * but other bufer_heads would be unmapped but dirty(dirty done via the
2740 * do_wp_page). So writepage should write the first block. If we modify
2741 * the mmap area beyond 1024 we will again get a page_fault and the
2742 * page_mkwrite callback will do the block allocation and mark the
2743 * buffer_heads mapped.
2745 * We redirty the page if we have any buffer_heads that is either delay or
2746 * unwritten in the page.
2748 * We can get recursively called as show below.
2750 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2753 * But since we don't do any block allocation we should not deadlock.
2754 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2756 static int ext4_writepage(struct page *page,
2757 struct writeback_control *wbc)
2759 int ret = 0, commit_write = 0;
2762 struct buffer_head *page_bufs = NULL;
2763 struct inode *inode = page->mapping->host;
2765 trace_ext4_writepage(inode, page);
2766 size = i_size_read(inode);
2767 if (page->index == size >> PAGE_CACHE_SHIFT)
2768 len = size & ~PAGE_CACHE_MASK;
2770 len = PAGE_CACHE_SIZE;
2773 * If the page does not have buffers (for whatever reason),
2774 * try to create them using block_prepare_write. If this
2775 * fails, redirty the page and move on.
2777 if (!page_buffers(page)) {
2778 if (block_prepare_write(page, 0, len,
2779 noalloc_get_block_write)) {
2781 redirty_page_for_writepage(wbc, page);
2787 page_bufs = page_buffers(page);
2788 if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2789 ext4_bh_delay_or_unwritten)) {
2791 * We don't want to do block allocation So redirty the
2792 * page and return We may reach here when we do a
2793 * journal commit via
2794 * journal_submit_inode_data_buffers. If we don't
2795 * have mapping block we just ignore them. We can also
2796 * reach here via shrink_page_list
2801 /* now mark the buffer_heads as dirty and uptodate */
2802 block_commit_write(page, 0, len);
2804 if (PageChecked(page) && ext4_should_journal_data(inode))
2806 * It's mmapped pagecache. Add buffers and journal it. There
2807 * doesn't seem much point in redirtying the page here.
2809 return __ext4_journalled_writepage(page, len);
2811 if (buffer_uninit(page_bufs)) {
2812 ext4_set_bh_endio(page_bufs, inode);
2813 ret = block_write_full_page_endio(page, noalloc_get_block_write,
2814 wbc, ext4_end_io_buffer_write);
2816 ret = block_write_full_page(page, noalloc_get_block_write,
2823 * This is called via ext4_da_writepages() to
2824 * calulate the total number of credits to reserve to fit
2825 * a single extent allocation into a single transaction,
2826 * ext4_da_writpeages() will loop calling this before
2827 * the block allocation.
2830 static int ext4_da_writepages_trans_blocks(struct inode *inode)
2832 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2835 * With non-extent format the journal credit needed to
2836 * insert nrblocks contiguous block is dependent on
2837 * number of contiguous block. So we will limit
2838 * number of contiguous block to a sane value
2840 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
2841 (max_blocks > EXT4_MAX_TRANS_DATA))
2842 max_blocks = EXT4_MAX_TRANS_DATA;
2844 return ext4_chunk_trans_blocks(inode, max_blocks);
2848 * write_cache_pages_da - walk the list of dirty pages of the given
2849 * address space and call the callback function (which usually writes
2852 * This is a forked version of write_cache_pages(). Differences:
2853 * Range cyclic is ignored.
2854 * no_nrwrite_index_update is always presumed true
2856 static int write_cache_pages_da(struct address_space *mapping,
2857 struct writeback_control *wbc,
2858 struct mpage_da_data *mpd)
2862 struct pagevec pvec;
2865 pgoff_t end; /* Inclusive */
2866 long nr_to_write = wbc->nr_to_write;
2868 pagevec_init(&pvec, 0);
2869 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2870 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2872 while (!done && (index <= end)) {
2875 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
2876 PAGECACHE_TAG_DIRTY,
2877 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2881 for (i = 0; i < nr_pages; i++) {
2882 struct page *page = pvec.pages[i];
2885 * At this point, the page may be truncated or
2886 * invalidated (changing page->mapping to NULL), or
2887 * even swizzled back from swapper_space to tmpfs file
2888 * mapping. However, page->index will not change
2889 * because we have a reference on the page.
2891 if (page->index > end) {
2899 * Page truncated or invalidated. We can freely skip it
2900 * then, even for data integrity operations: the page
2901 * has disappeared concurrently, so there could be no
2902 * real expectation of this data interity operation
2903 * even if there is now a new, dirty page at the same
2904 * pagecache address.
2906 if (unlikely(page->mapping != mapping)) {
2912 if (!PageDirty(page)) {
2913 /* someone wrote it for us */
2914 goto continue_unlock;
2917 if (PageWriteback(page)) {
2918 if (wbc->sync_mode != WB_SYNC_NONE)
2919 wait_on_page_writeback(page);
2921 goto continue_unlock;
2924 BUG_ON(PageWriteback(page));
2925 if (!clear_page_dirty_for_io(page))
2926 goto continue_unlock;
2928 ret = __mpage_da_writepage(page, wbc, mpd);
2929 if (unlikely(ret)) {
2930 if (ret == AOP_WRITEPAGE_ACTIVATE) {
2939 if (nr_to_write > 0) {
2941 if (nr_to_write == 0 &&
2942 wbc->sync_mode == WB_SYNC_NONE) {
2944 * We stop writing back only if we are
2945 * not doing integrity sync. In case of
2946 * integrity sync we have to keep going
2947 * because someone may be concurrently
2948 * dirtying pages, and we might have
2949 * synced a lot of newly appeared dirty
2950 * pages, but have not synced all of the
2958 pagevec_release(&pvec);
2965 static int ext4_da_writepages(struct address_space *mapping,
2966 struct writeback_control *wbc)
2969 int range_whole = 0;
2970 handle_t *handle = NULL;
2971 struct mpage_da_data mpd;
2972 struct inode *inode = mapping->host;
2973 int pages_written = 0;
2975 unsigned int max_pages;
2976 int range_cyclic, cycled = 1, io_done = 0;
2977 int needed_blocks, ret = 0;
2978 long desired_nr_to_write, nr_to_writebump = 0;
2979 loff_t range_start = wbc->range_start;
2980 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2982 trace_ext4_da_writepages(inode, wbc);
2985 * No pages to write? This is mainly a kludge to avoid starting
2986 * a transaction for special inodes like journal inode on last iput()
2987 * because that could violate lock ordering on umount
2989 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2993 * If the filesystem has aborted, it is read-only, so return
2994 * right away instead of dumping stack traces later on that
2995 * will obscure the real source of the problem. We test
2996 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2997 * the latter could be true if the filesystem is mounted
2998 * read-only, and in that case, ext4_da_writepages should
2999 * *never* be called, so if that ever happens, we would want
3002 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
3005 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
3008 range_cyclic = wbc->range_cyclic;
3009 if (wbc->range_cyclic) {
3010 index = mapping->writeback_index;
3013 wbc->range_start = index << PAGE_CACHE_SHIFT;
3014 wbc->range_end = LLONG_MAX;
3015 wbc->range_cyclic = 0;
3017 index = wbc->range_start >> PAGE_CACHE_SHIFT;
3020 * This works around two forms of stupidity. The first is in
3021 * the writeback code, which caps the maximum number of pages
3022 * written to be 1024 pages. This is wrong on multiple
3023 * levels; different architectues have a different page size,
3024 * which changes the maximum amount of data which gets
3025 * written. Secondly, 4 megabytes is way too small. XFS
3026 * forces this value to be 16 megabytes by multiplying
3027 * nr_to_write parameter by four, and then relies on its
3028 * allocator to allocate larger extents to make them
3029 * contiguous. Unfortunately this brings us to the second
3030 * stupidity, which is that ext4's mballoc code only allocates
3031 * at most 2048 blocks. So we force contiguous writes up to
3032 * the number of dirty blocks in the inode, or
3033 * sbi->max_writeback_mb_bump whichever is smaller.
3035 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
3036 if (!range_cyclic && range_whole) {
3037 if (wbc->nr_to_write == LONG_MAX)
3038 desired_nr_to_write = wbc->nr_to_write;
3040 desired_nr_to_write = wbc->nr_to_write * 8;
3042 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
3044 if (desired_nr_to_write > max_pages)
3045 desired_nr_to_write = max_pages;
3047 if (wbc->nr_to_write < desired_nr_to_write) {
3048 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
3049 wbc->nr_to_write = desired_nr_to_write;
3053 mpd.inode = mapping->host;
3055 pages_skipped = wbc->pages_skipped;
3058 while (!ret && wbc->nr_to_write > 0) {
3061 * we insert one extent at a time. So we need
3062 * credit needed for single extent allocation.
3063 * journalled mode is currently not supported
3066 BUG_ON(ext4_should_journal_data(inode));
3067 needed_blocks = ext4_da_writepages_trans_blocks(inode);
3069 /* start a new transaction*/
3070 handle = ext4_journal_start(inode, needed_blocks);
3071 if (IS_ERR(handle)) {
3072 ret = PTR_ERR(handle);
3073 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
3074 "%ld pages, ino %lu; err %d", __func__,
3075 wbc->nr_to_write, inode->i_ino, ret);
3076 goto out_writepages;
3080 * Now call __mpage_da_writepage to find the next
3081 * contiguous region of logical blocks that need
3082 * blocks to be allocated by ext4. We don't actually
3083 * submit the blocks for I/O here, even though
3084 * write_cache_pages thinks it will, and will set the
3085 * pages as clean for write before calling
3086 * __mpage_da_writepage().
3094 mpd.pages_written = 0;
3096 ret = write_cache_pages_da(mapping, wbc, &mpd);
3098 * If we have a contiguous extent of pages and we
3099 * haven't done the I/O yet, map the blocks and submit
3102 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
3103 mpage_da_map_and_submit(&mpd);
3104 ret = MPAGE_DA_EXTENT_TAIL;
3106 trace_ext4_da_write_pages(inode, &mpd);
3107 wbc->nr_to_write -= mpd.pages_written;
3109 ext4_journal_stop(handle);
3111 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
3112 /* commit the transaction which would
3113 * free blocks released in the transaction
3116 jbd2_journal_force_commit_nested(sbi->s_journal);
3117 wbc->pages_skipped = pages_skipped;
3119 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
3121 * got one extent now try with
3124 pages_written += mpd.pages_written;
3125 wbc->pages_skipped = pages_skipped;
3128 } else if (wbc->nr_to_write)
3130 * There is no more writeout needed
3131 * or we requested for a noblocking writeout
3132 * and we found the device congested
3136 if (!io_done && !cycled) {
3139 wbc->range_start = index << PAGE_CACHE_SHIFT;
3140 wbc->range_end = mapping->writeback_index - 1;
3143 if (pages_skipped != wbc->pages_skipped)
3144 ext4_msg(inode->i_sb, KERN_CRIT,
3145 "This should not happen leaving %s "
3146 "with nr_to_write = %ld ret = %d",
3147 __func__, wbc->nr_to_write, ret);
3150 index += pages_written;
3151 wbc->range_cyclic = range_cyclic;
3152 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
3154 * set the writeback_index so that range_cyclic
3155 * mode will write it back later
3157 mapping->writeback_index = index;
3160 wbc->nr_to_write -= nr_to_writebump;
3161 wbc->range_start = range_start;
3162 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
3166 #define FALL_BACK_TO_NONDELALLOC 1
3167 static int ext4_nonda_switch(struct super_block *sb)
3169 s64 free_blocks, dirty_blocks;
3170 struct ext4_sb_info *sbi = EXT4_SB(sb);
3173 * switch to non delalloc mode if we are running low
3174 * on free block. The free block accounting via percpu
3175 * counters can get slightly wrong with percpu_counter_batch getting
3176 * accumulated on each CPU without updating global counters
3177 * Delalloc need an accurate free block accounting. So switch
3178 * to non delalloc when we are near to error range.
3180 free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
3181 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter);
3182 if (2 * free_blocks < 3 * dirty_blocks ||
3183 free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) {
3185 * free block count is less than 150% of dirty blocks
3186 * or free blocks is less than watermark
3191 * Even if we don't switch but are nearing capacity,
3192 * start pushing delalloc when 1/2 of free blocks are dirty.
3194 if (free_blocks < 2 * dirty_blocks)
3195 writeback_inodes_sb_if_idle(sb);
3200 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
3201 loff_t pos, unsigned len, unsigned flags,
3202 struct page **pagep, void **fsdata)
3204 int ret, retries = 0;
3207 struct inode *inode = mapping->host;
3210 index = pos >> PAGE_CACHE_SHIFT;
3212 if (ext4_nonda_switch(inode->i_sb)) {
3213 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
3214 return ext4_write_begin(file, mapping, pos,
3215 len, flags, pagep, fsdata);
3217 *fsdata = (void *)0;
3218 trace_ext4_da_write_begin(inode, pos, len, flags);
3221 * With delayed allocation, we don't log the i_disksize update
3222 * if there is delayed block allocation. But we still need
3223 * to journalling the i_disksize update if writes to the end
3224 * of file which has an already mapped buffer.
3226 handle = ext4_journal_start(inode, 1);
3227 if (IS_ERR(handle)) {
3228 ret = PTR_ERR(handle);
3231 /* We cannot recurse into the filesystem as the transaction is already
3233 flags |= AOP_FLAG_NOFS;
3235 page = grab_cache_page_write_begin(mapping, index, flags);
3237 ext4_journal_stop(handle);
3243 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
3246 ext4_journal_stop(handle);
3247 page_cache_release(page);
3249 * block_write_begin may have instantiated a few blocks
3250 * outside i_size. Trim these off again. Don't need
3251 * i_size_read because we hold i_mutex.
3253 if (pos + len > inode->i_size)
3254 ext4_truncate_failed_write(inode);
3257 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
3264 * Check if we should update i_disksize
3265 * when write to the end of file but not require block allocation
3267 static int ext4_da_should_update_i_disksize(struct page *page,
3268 unsigned long offset)
3270 struct buffer_head *bh;
3271 struct inode *inode = page->mapping->host;
3275 bh = page_buffers(page);
3276 idx = offset >> inode->i_blkbits;
3278 for (i = 0; i < idx; i++)
3279 bh = bh->b_this_page;
3281 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
3286 static int ext4_da_write_end(struct file *file,
3287 struct address_space *mapping,
3288 loff_t pos, unsigned len, unsigned copied,
3289 struct page *page, void *fsdata)
3291 struct inode *inode = mapping->host;
3293 handle_t *handle = ext4_journal_current_handle();
3295 unsigned long start, end;
3296 int write_mode = (int)(unsigned long)fsdata;
3298 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
3299 if (ext4_should_order_data(inode)) {
3300 return ext4_ordered_write_end(file, mapping, pos,
3301 len, copied, page, fsdata);
3302 } else if (ext4_should_writeback_data(inode)) {
3303 return ext4_writeback_write_end(file, mapping, pos,
3304 len, copied, page, fsdata);
3310 trace_ext4_da_write_end(inode, pos, len, copied);
3311 start = pos & (PAGE_CACHE_SIZE - 1);
3312 end = start + copied - 1;
3315 * generic_write_end() will run mark_inode_dirty() if i_size
3316 * changes. So let's piggyback the i_disksize mark_inode_dirty
3320 new_i_size = pos + copied;
3321 if (new_i_size > EXT4_I(inode)->i_disksize) {
3322 if (ext4_da_should_update_i_disksize(page, end)) {
3323 down_write(&EXT4_I(inode)->i_data_sem);
3324 if (new_i_size > EXT4_I(inode)->i_disksize) {
3326 * Updating i_disksize when extending file
3327 * without needing block allocation
3329 if (ext4_should_order_data(inode))
3330 ret = ext4_jbd2_file_inode(handle,
3333 EXT4_I(inode)->i_disksize = new_i_size;
3335 up_write(&EXT4_I(inode)->i_data_sem);
3336 /* We need to mark inode dirty even if
3337 * new_i_size is less that inode->i_size
3338 * bu greater than i_disksize.(hint delalloc)
3340 ext4_mark_inode_dirty(handle, inode);
3343 ret2 = generic_write_end(file, mapping, pos, len, copied,
3348 ret2 = ext4_journal_stop(handle);
3352 return ret ? ret : copied;
3355 static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
3358 * Drop reserved blocks
3360 BUG_ON(!PageLocked(page));
3361 if (!page_has_buffers(page))
3364 ext4_da_page_release_reservation(page, offset);
3367 ext4_invalidatepage(page, offset);
3373 * Force all delayed allocation blocks to be allocated for a given inode.
3375 int ext4_alloc_da_blocks(struct inode *inode)
3377 trace_ext4_alloc_da_blocks(inode);
3379 if (!EXT4_I(inode)->i_reserved_data_blocks &&
3380 !EXT4_I(inode)->i_reserved_meta_blocks)
3384 * We do something simple for now. The filemap_flush() will
3385 * also start triggering a write of the data blocks, which is
3386 * not strictly speaking necessary (and for users of
3387 * laptop_mode, not even desirable). However, to do otherwise
3388 * would require replicating code paths in:
3390 * ext4_da_writepages() ->
3391 * write_cache_pages() ---> (via passed in callback function)
3392 * __mpage_da_writepage() -->
3393 * mpage_add_bh_to_extent()
3394 * mpage_da_map_blocks()
3396 * The problem is that write_cache_pages(), located in
3397 * mm/page-writeback.c, marks pages clean in preparation for
3398 * doing I/O, which is not desirable if we're not planning on
3401 * We could call write_cache_pages(), and then redirty all of
3402 * the pages by calling redirty_page_for_writeback() but that
3403 * would be ugly in the extreme. So instead we would need to
3404 * replicate parts of the code in the above functions,
3405 * simplifying them becuase we wouldn't actually intend to
3406 * write out the pages, but rather only collect contiguous
3407 * logical block extents, call the multi-block allocator, and
3408 * then update the buffer heads with the block allocations.
3410 * For now, though, we'll cheat by calling filemap_flush(),
3411 * which will map the blocks, and start the I/O, but not
3412 * actually wait for the I/O to complete.
3414 return filemap_flush(inode->i_mapping);
3418 * bmap() is special. It gets used by applications such as lilo and by
3419 * the swapper to find the on-disk block of a specific piece of data.
3421 * Naturally, this is dangerous if the block concerned is still in the
3422 * journal. If somebody makes a swapfile on an ext4 data-journaling
3423 * filesystem and enables swap, then they may get a nasty shock when the
3424 * data getting swapped to that swapfile suddenly gets overwritten by
3425 * the original zero's written out previously to the journal and
3426 * awaiting writeback in the kernel's buffer cache.
3428 * So, if we see any bmap calls here on a modified, data-journaled file,
3429 * take extra steps to flush any blocks which might be in the cache.
3431 static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
3433 struct inode *inode = mapping->host;
3437 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3438 test_opt(inode->i_sb, DELALLOC)) {
3440 * With delalloc we want to sync the file
3441 * so that we can make sure we allocate
3444 filemap_write_and_wait(mapping);
3447 if (EXT4_JOURNAL(inode) &&
3448 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
3450 * This is a REALLY heavyweight approach, but the use of
3451 * bmap on dirty files is expected to be extremely rare:
3452 * only if we run lilo or swapon on a freshly made file
3453 * do we expect this to happen.
3455 * (bmap requires CAP_SYS_RAWIO so this does not
3456 * represent an unprivileged user DOS attack --- we'd be
3457 * in trouble if mortal users could trigger this path at
3460 * NB. EXT4_STATE_JDATA is not set on files other than
3461 * regular files. If somebody wants to bmap a directory
3462 * or symlink and gets confused because the buffer
3463 * hasn't yet been flushed to disk, they deserve
3464 * everything they get.
3467 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
3468 journal = EXT4_JOURNAL(inode);
3469 jbd2_journal_lock_updates(journal);
3470 err = jbd2_journal_flush(journal);
3471 jbd2_journal_unlock_updates(journal);
3477 return generic_block_bmap(mapping, block, ext4_get_block);
3480 static int ext4_readpage(struct file *file, struct page *page)
3482 return mpage_readpage(page, ext4_get_block);
3486 ext4_readpages(struct file *file, struct address_space *mapping,
3487 struct list_head *pages, unsigned nr_pages)
3489 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
3492 static void ext4_free_io_end(ext4_io_end_t *io)
3501 static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset)
3503 struct buffer_head *head, *bh;
3504 unsigned int curr_off = 0;
3506 if (!page_has_buffers(page))
3508 head = bh = page_buffers(page);
3510 if (offset <= curr_off && test_clear_buffer_uninit(bh)
3512 ext4_free_io_end(bh->b_private);
3513 bh->b_private = NULL;
3514 bh->b_end_io = NULL;
3516 curr_off = curr_off + bh->b_size;
3517 bh = bh->b_this_page;
3518 } while (bh != head);
3521 static void ext4_invalidatepage(struct page *page, unsigned long offset)
3523 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3526 * free any io_end structure allocated for buffers to be discarded
3528 if (ext4_should_dioread_nolock(page->mapping->host))
3529 ext4_invalidatepage_free_endio(page, offset);
3531 * If it's a full truncate we just forget about the pending dirtying
3534 ClearPageChecked(page);
3537 jbd2_journal_invalidatepage(journal, page, offset);
3539 block_invalidatepage(page, offset);
3542 static int ext4_releasepage(struct page *page, gfp_t wait)
3544 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3546 WARN_ON(PageChecked(page));
3547 if (!page_has_buffers(page))
3550 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3552 return try_to_free_buffers(page);
3556 * O_DIRECT for ext3 (or indirect map) based files
3558 * If the O_DIRECT write will extend the file then add this inode to the
3559 * orphan list. So recovery will truncate it back to the original size
3560 * if the machine crashes during the write.
3562 * If the O_DIRECT write is intantiating holes inside i_size and the machine
3563 * crashes then stale disk data _may_ be exposed inside the file. But current
3564 * VFS code falls back into buffered path in that case so we are safe.
3566 static ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
3567 const struct iovec *iov, loff_t offset,
3568 unsigned long nr_segs)
3570 struct file *file = iocb->ki_filp;
3571 struct inode *inode = file->f_mapping->host;
3572 struct ext4_inode_info *ei = EXT4_I(inode);
3576 size_t count = iov_length(iov, nr_segs);
3580 loff_t final_size = offset + count;
3582 if (final_size > inode->i_size) {
3583 /* Credits for sb + inode write */
3584 handle = ext4_journal_start(inode, 2);
3585 if (IS_ERR(handle)) {
3586 ret = PTR_ERR(handle);
3589 ret = ext4_orphan_add(handle, inode);
3591 ext4_journal_stop(handle);
3595 ei->i_disksize = inode->i_size;
3596 ext4_journal_stop(handle);
3601 if (rw == READ && ext4_should_dioread_nolock(inode))
3602 ret = __blockdev_direct_IO(rw, iocb, inode,
3603 inode->i_sb->s_bdev, iov,
3605 ext4_get_block, NULL, NULL, 0);
3607 ret = blockdev_direct_IO(rw, iocb, inode,
3608 inode->i_sb->s_bdev, iov,
3610 ext4_get_block, NULL);
3612 if (unlikely((rw & WRITE) && ret < 0)) {
3613 loff_t isize = i_size_read(inode);
3614 loff_t end = offset + iov_length(iov, nr_segs);
3617 vmtruncate(inode, isize);
3620 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
3626 /* Credits for sb + inode write */
3627 handle = ext4_journal_start(inode, 2);
3628 if (IS_ERR(handle)) {
3629 /* This is really bad luck. We've written the data
3630 * but cannot extend i_size. Bail out and pretend
3631 * the write failed... */
3632 ret = PTR_ERR(handle);
3634 ext4_orphan_del(NULL, inode);
3639 ext4_orphan_del(handle, inode);
3641 loff_t end = offset + ret;
3642 if (end > inode->i_size) {
3643 ei->i_disksize = end;
3644 i_size_write(inode, end);
3646 * We're going to return a positive `ret'
3647 * here due to non-zero-length I/O, so there's
3648 * no way of reporting error returns from
3649 * ext4_mark_inode_dirty() to userspace. So
3652 ext4_mark_inode_dirty(handle, inode);
3655 err = ext4_journal_stop(handle);
3664 * ext4_get_block used when preparing for a DIO write or buffer write.
3665 * We allocate an uinitialized extent if blocks haven't been allocated.
3666 * The extent will be converted to initialized after the IO is complete.
3668 static int ext4_get_block_write(struct inode *inode, sector_t iblock,
3669 struct buffer_head *bh_result, int create)
3671 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
3672 inode->i_ino, create);
3673 return _ext4_get_block(inode, iblock, bh_result,
3674 EXT4_GET_BLOCKS_IO_CREATE_EXT);
3677 static void dump_completed_IO(struct inode * inode)
3680 struct list_head *cur, *before, *after;
3681 ext4_io_end_t *io, *io0, *io1;
3682 unsigned long flags;
3684 if (list_empty(&EXT4_I(inode)->i_completed_io_list)){
3685 ext4_debug("inode %lu completed_io list is empty\n", inode->i_ino);
3689 ext4_debug("Dump inode %lu completed_io list \n", inode->i_ino);
3690 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
3691 list_for_each_entry(io, &EXT4_I(inode)->i_completed_io_list, list){
3694 io0 = container_of(before, ext4_io_end_t, list);
3696 io1 = container_of(after, ext4_io_end_t, list);
3698 ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
3699 io, inode->i_ino, io0, io1);
3701 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
3706 * check a range of space and convert unwritten extents to written.
3708 static int ext4_end_io_nolock(ext4_io_end_t *io)
3710 struct inode *inode = io->inode;
3711 loff_t offset = io->offset;
3712 ssize_t size = io->size;
3715 ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
3716 "list->prev 0x%p\n",
3717 io, inode->i_ino, io->list.next, io->list.prev);
3719 if (list_empty(&io->list))
3722 if (io->flag != EXT4_IO_UNWRITTEN)
3725 ret = ext4_convert_unwritten_extents(inode, offset, size);
3727 printk(KERN_EMERG "%s: failed to convert unwritten"
3728 "extents to written extents, error is %d"
3729 " io is still on inode %lu aio dio list\n",
3730 __func__, ret, inode->i_ino);
3735 aio_complete(io->iocb, io->result, 0);
3736 /* clear the DIO AIO unwritten flag */
3742 * work on completed aio dio IO, to convert unwritten extents to extents
3744 static void ext4_end_io_work(struct work_struct *work)
3746 ext4_io_end_t *io = container_of(work, ext4_io_end_t, work);
3747 struct inode *inode = io->inode;
3748 struct ext4_inode_info *ei = EXT4_I(inode);
3749 unsigned long flags;
3752 mutex_lock(&inode->i_mutex);
3753 ret = ext4_end_io_nolock(io);
3755 mutex_unlock(&inode->i_mutex);
3759 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
3760 if (!list_empty(&io->list))
3761 list_del_init(&io->list);
3762 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
3763 mutex_unlock(&inode->i_mutex);
3764 ext4_free_io_end(io);
3768 * This function is called from ext4_sync_file().
3770 * When IO is completed, the work to convert unwritten extents to
3771 * written is queued on workqueue but may not get immediately
3772 * scheduled. When fsync is called, we need to ensure the
3773 * conversion is complete before fsync returns.
3774 * The inode keeps track of a list of pending/completed IO that
3775 * might needs to do the conversion. This function walks through
3776 * the list and convert the related unwritten extents for completed IO
3778 * The function return the number of pending IOs on success.
3780 int flush_completed_IO(struct inode *inode)
3783 struct ext4_inode_info *ei = EXT4_I(inode);
3784 unsigned long flags;
3788 if (list_empty(&ei->i_completed_io_list))
3791 dump_completed_IO(inode);
3792 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
3793 while (!list_empty(&ei->i_completed_io_list)){
3794 io = list_entry(ei->i_completed_io_list.next,
3795 ext4_io_end_t, list);
3797 * Calling ext4_end_io_nolock() to convert completed
3800 * When ext4_sync_file() is called, run_queue() may already
3801 * about to flush the work corresponding to this io structure.
3802 * It will be upset if it founds the io structure related
3803 * to the work-to-be schedule is freed.
3805 * Thus we need to keep the io structure still valid here after
3806 * convertion finished. The io structure has a flag to
3807 * avoid double converting from both fsync and background work
3810 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
3811 ret = ext4_end_io_nolock(io);
3812 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
3816 list_del_init(&io->list);
3818 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
3819 return (ret2 < 0) ? ret2 : 0;
3822 static ext4_io_end_t *ext4_init_io_end (struct inode *inode, gfp_t flags)
3824 ext4_io_end_t *io = NULL;
3826 io = kmalloc(sizeof(*io), flags);
3837 INIT_WORK(&io->work, ext4_end_io_work);
3838 INIT_LIST_HEAD(&io->list);
3844 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
3845 ssize_t size, void *private, int ret,
3848 ext4_io_end_t *io_end = iocb->private;
3849 struct workqueue_struct *wq;
3850 unsigned long flags;
3851 struct ext4_inode_info *ei;
3853 /* if not async direct IO or dio with 0 bytes write, just return */
3854 if (!io_end || !size)
3857 ext_debug("ext4_end_io_dio(): io_end 0x%p"
3858 "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
3859 iocb->private, io_end->inode->i_ino, iocb, offset,
3862 /* if not aio dio with unwritten extents, just free io and return */
3863 if (io_end->flag != EXT4_IO_UNWRITTEN){
3864 ext4_free_io_end(io_end);
3865 iocb->private = NULL;
3868 aio_complete(iocb, ret, 0);
3872 io_end->offset = offset;
3873 io_end->size = size;
3875 io_end->iocb = iocb;
3876 io_end->result = ret;
3878 wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
3880 /* Add the io_end to per-inode completed aio dio list*/
3881 ei = EXT4_I(io_end->inode);
3882 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
3883 list_add_tail(&io_end->list, &ei->i_completed_io_list);
3884 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
3886 /* queue the work to convert unwritten extents to written */
3887 queue_work(wq, &io_end->work);
3888 iocb->private = NULL;
3891 static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
3893 ext4_io_end_t *io_end = bh->b_private;
3894 struct workqueue_struct *wq;
3895 struct inode *inode;
3896 unsigned long flags;
3898 if (!test_clear_buffer_uninit(bh) || !io_end)
3901 if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
3902 printk("sb umounted, discard end_io request for inode %lu\n",
3903 io_end->inode->i_ino);
3904 ext4_free_io_end(io_end);
3908 io_end->flag = EXT4_IO_UNWRITTEN;
3909 inode = io_end->inode;
3911 /* Add the io_end to per-inode completed io list*/
3912 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
3913 list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
3914 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
3916 wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
3917 /* queue the work to convert unwritten extents to written */
3918 queue_work(wq, &io_end->work);
3920 bh->b_private = NULL;
3921 bh->b_end_io = NULL;
3922 clear_buffer_uninit(bh);
3923 end_buffer_async_write(bh, uptodate);
3926 static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
3928 ext4_io_end_t *io_end;
3929 struct page *page = bh->b_page;
3930 loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
3931 size_t size = bh->b_size;
3934 io_end = ext4_init_io_end(inode, GFP_ATOMIC);
3936 if (printk_ratelimit())
3937 printk(KERN_WARNING "%s: allocation fail\n", __func__);
3941 io_end->offset = offset;
3942 io_end->size = size;
3944 * We need to hold a reference to the page to make sure it
3945 * doesn't get evicted before ext4_end_io_work() has a chance
3946 * to convert the extent from written to unwritten.
3948 io_end->page = page;
3949 get_page(io_end->page);
3951 bh->b_private = io_end;
3952 bh->b_end_io = ext4_end_io_buffer_write;
3957 * For ext4 extent files, ext4 will do direct-io write to holes,
3958 * preallocated extents, and those write extend the file, no need to
3959 * fall back to buffered IO.
3961 * For holes, we fallocate those blocks, mark them as unintialized
3962 * If those blocks were preallocated, we mark sure they are splited, but
3963 * still keep the range to write as unintialized.
3965 * The unwrritten extents will be converted to written when DIO is completed.
3966 * For async direct IO, since the IO may still pending when return, we
3967 * set up an end_io call back function, which will do the convertion
3968 * when async direct IO completed.
3970 * If the O_DIRECT write will extend the file then add this inode to the
3971 * orphan list. So recovery will truncate it back to the original size
3972 * if the machine crashes during the write.
3975 static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
3976 const struct iovec *iov, loff_t offset,
3977 unsigned long nr_segs)
3979 struct file *file = iocb->ki_filp;
3980 struct inode *inode = file->f_mapping->host;
3982 size_t count = iov_length(iov, nr_segs);
3984 loff_t final_size = offset + count;
3985 if (rw == WRITE && final_size <= inode->i_size) {
3987 * We could direct write to holes and fallocate.
3989 * Allocated blocks to fill the hole are marked as uninitialized
3990 * to prevent paralel buffered read to expose the stale data
3991 * before DIO complete the data IO.
3993 * As to previously fallocated extents, ext4 get_block
3994 * will just simply mark the buffer mapped but still
3995 * keep the extents uninitialized.
3997 * for non AIO case, we will convert those unwritten extents
3998 * to written after return back from blockdev_direct_IO.
4000 * for async DIO, the conversion needs to be defered when
4001 * the IO is completed. The ext4 end_io callback function
4002 * will be called to take care of the conversion work.
4003 * Here for async case, we allocate an io_end structure to
4006 iocb->private = NULL;
4007 EXT4_I(inode)->cur_aio_dio = NULL;
4008 if (!is_sync_kiocb(iocb)) {
4009 iocb->private = ext4_init_io_end(inode, GFP_NOFS);
4013 * we save the io structure for current async
4014 * direct IO, so that later ext4_map_blocks()
4015 * could flag the io structure whether there
4016 * is a unwritten extents needs to be converted
4017 * when IO is completed.
4019 EXT4_I(inode)->cur_aio_dio = iocb->private;
4022 ret = blockdev_direct_IO(rw, iocb, inode,
4023 inode->i_sb->s_bdev, iov,
4025 ext4_get_block_write,
4028 EXT4_I(inode)->cur_aio_dio = NULL;
4030 * The io_end structure takes a reference to the inode,
4031 * that structure needs to be destroyed and the
4032 * reference to the inode need to be dropped, when IO is
4033 * complete, even with 0 byte write, or failed.
4035 * In the successful AIO DIO case, the io_end structure will be
4036 * desctroyed and the reference to the inode will be dropped
4037 * after the end_io call back function is called.
4039 * In the case there is 0 byte write, or error case, since
4040 * VFS direct IO won't invoke the end_io call back function,
4041 * we need to free the end_io structure here.
4043 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
4044 ext4_free_io_end(iocb->private);
4045 iocb->private = NULL;
4046 } else if (ret > 0 && ext4_test_inode_state(inode,
4047 EXT4_STATE_DIO_UNWRITTEN)) {
4050 * for non AIO case, since the IO is already
4051 * completed, we could do the convertion right here
4053 err = ext4_convert_unwritten_extents(inode,
4057 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
4062 /* for write the the end of file case, we fall back to old way */
4063 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
4066 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
4067 const struct iovec *iov, loff_t offset,
4068 unsigned long nr_segs)
4070 struct file *file = iocb->ki_filp;
4071 struct inode *inode = file->f_mapping->host;
4073 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4074 return ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
4076 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
4080 * Pages can be marked dirty completely asynchronously from ext4's journalling
4081 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
4082 * much here because ->set_page_dirty is called under VFS locks. The page is
4083 * not necessarily locked.
4085 * We cannot just dirty the page and leave attached buffers clean, because the
4086 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
4087 * or jbddirty because all the journalling code will explode.
4089 * So what we do is to mark the page "pending dirty" and next time writepage
4090 * is called, propagate that into the buffers appropriately.
4092 static int ext4_journalled_set_page_dirty(struct page *page)
4094 SetPageChecked(page);
4095 return __set_page_dirty_nobuffers(page);
4098 static const struct address_space_operations ext4_ordered_aops = {
4099 .readpage = ext4_readpage,
4100 .readpages = ext4_readpages,
4101 .writepage = ext4_writepage,
4102 .sync_page = block_sync_page,
4103 .write_begin = ext4_write_begin,
4104 .write_end = ext4_ordered_write_end,
4106 .invalidatepage = ext4_invalidatepage,
4107 .releasepage = ext4_releasepage,
4108 .direct_IO = ext4_direct_IO,
4109 .migratepage = buffer_migrate_page,
4110 .is_partially_uptodate = block_is_partially_uptodate,
4111 .error_remove_page = generic_error_remove_page,
4114 static const struct address_space_operations ext4_writeback_aops = {
4115 .readpage = ext4_readpage,
4116 .readpages = ext4_readpages,
4117 .writepage = ext4_writepage,
4118 .sync_page = block_sync_page,
4119 .write_begin = ext4_write_begin,
4120 .write_end = ext4_writeback_write_end,
4122 .invalidatepage = ext4_invalidatepage,
4123 .releasepage = ext4_releasepage,
4124 .direct_IO = ext4_direct_IO,
4125 .migratepage = buffer_migrate_page,
4126 .is_partially_uptodate = block_is_partially_uptodate,
4127 .error_remove_page = generic_error_remove_page,
4130 static const struct address_space_operations ext4_journalled_aops = {
4131 .readpage = ext4_readpage,
4132 .readpages = ext4_readpages,
4133 .writepage = ext4_writepage,
4134 .sync_page = block_sync_page,
4135 .write_begin = ext4_write_begin,
4136 .write_end = ext4_journalled_write_end,
4137 .set_page_dirty = ext4_journalled_set_page_dirty,
4139 .invalidatepage = ext4_invalidatepage,
4140 .releasepage = ext4_releasepage,
4141 .is_partially_uptodate = block_is_partially_uptodate,
4142 .error_remove_page = generic_error_remove_page,
4145 static const struct address_space_operations ext4_da_aops = {
4146 .readpage = ext4_readpage,
4147 .readpages = ext4_readpages,
4148 .writepage = ext4_writepage,
4149 .writepages = ext4_da_writepages,
4150 .sync_page = block_sync_page,
4151 .write_begin = ext4_da_write_begin,
4152 .write_end = ext4_da_write_end,
4154 .invalidatepage = ext4_da_invalidatepage,
4155 .releasepage = ext4_releasepage,
4156 .direct_IO = ext4_direct_IO,
4157 .migratepage = buffer_migrate_page,
4158 .is_partially_uptodate = block_is_partially_uptodate,
4159 .error_remove_page = generic_error_remove_page,
4162 void ext4_set_aops(struct inode *inode)
4164 if (ext4_should_order_data(inode) &&
4165 test_opt(inode->i_sb, DELALLOC))
4166 inode->i_mapping->a_ops = &ext4_da_aops;
4167 else if (ext4_should_order_data(inode))
4168 inode->i_mapping->a_ops = &ext4_ordered_aops;
4169 else if (ext4_should_writeback_data(inode) &&
4170 test_opt(inode->i_sb, DELALLOC))
4171 inode->i_mapping->a_ops = &ext4_da_aops;
4172 else if (ext4_should_writeback_data(inode))
4173 inode->i_mapping->a_ops = &ext4_writeback_aops;
4175 inode->i_mapping->a_ops = &ext4_journalled_aops;
4179 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
4180 * up to the end of the block which corresponds to `from'.
4181 * This required during truncate. We need to physically zero the tail end
4182 * of that block so it doesn't yield old data if the file is later grown.
4184 int ext4_block_truncate_page(handle_t *handle,
4185 struct address_space *mapping, loff_t from)
4187 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
4188 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4189 unsigned blocksize, length, pos;
4191 struct inode *inode = mapping->host;
4192 struct buffer_head *bh;
4196 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
4197 mapping_gfp_mask(mapping) & ~__GFP_FS);
4201 blocksize = inode->i_sb->s_blocksize;
4202 length = blocksize - (offset & (blocksize - 1));
4203 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
4205 if (!page_has_buffers(page))
4206 create_empty_buffers(page, blocksize, 0);
4208 /* Find the buffer that contains "offset" */
4209 bh = page_buffers(page);
4211 while (offset >= pos) {
4212 bh = bh->b_this_page;
4218 if (buffer_freed(bh)) {
4219 BUFFER_TRACE(bh, "freed: skip");
4223 if (!buffer_mapped(bh)) {
4224 BUFFER_TRACE(bh, "unmapped");
4225 ext4_get_block(inode, iblock, bh, 0);
4226 /* unmapped? It's a hole - nothing to do */
4227 if (!buffer_mapped(bh)) {
4228 BUFFER_TRACE(bh, "still unmapped");
4233 /* Ok, it's mapped. Make sure it's up-to-date */
4234 if (PageUptodate(page))
4235 set_buffer_uptodate(bh);
4237 if (!buffer_uptodate(bh)) {
4239 ll_rw_block(READ, 1, &bh);
4241 /* Uhhuh. Read error. Complain and punt. */
4242 if (!buffer_uptodate(bh))
4246 if (ext4_should_journal_data(inode)) {
4247 BUFFER_TRACE(bh, "get write access");
4248 err = ext4_journal_get_write_access(handle, bh);
4253 zero_user(page, offset, length);
4255 BUFFER_TRACE(bh, "zeroed end of block");
4258 if (ext4_should_journal_data(inode)) {
4259 err = ext4_handle_dirty_metadata(handle, inode, bh);
4261 if (ext4_should_order_data(inode))
4262 err = ext4_jbd2_file_inode(handle, inode);
4263 mark_buffer_dirty(bh);
4268 page_cache_release(page);
4273 * Probably it should be a library function... search for first non-zero word
4274 * or memcmp with zero_page, whatever is better for particular architecture.
4277 static inline int all_zeroes(__le32 *p, __le32 *q)
4286 * ext4_find_shared - find the indirect blocks for partial truncation.
4287 * @inode: inode in question
4288 * @depth: depth of the affected branch
4289 * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
4290 * @chain: place to store the pointers to partial indirect blocks
4291 * @top: place to the (detached) top of branch
4293 * This is a helper function used by ext4_truncate().
4295 * When we do truncate() we may have to clean the ends of several
4296 * indirect blocks but leave the blocks themselves alive. Block is
4297 * partially truncated if some data below the new i_size is refered
4298 * from it (and it is on the path to the first completely truncated
4299 * data block, indeed). We have to free the top of that path along
4300 * with everything to the right of the path. Since no allocation
4301 * past the truncation point is possible until ext4_truncate()
4302 * finishes, we may safely do the latter, but top of branch may
4303 * require special attention - pageout below the truncation point
4304 * might try to populate it.
4306 * We atomically detach the top of branch from the tree, store the
4307 * block number of its root in *@top, pointers to buffer_heads of
4308 * partially truncated blocks - in @chain[].bh and pointers to
4309 * their last elements that should not be removed - in
4310 * @chain[].p. Return value is the pointer to last filled element
4313 * The work left to caller to do the actual freeing of subtrees:
4314 * a) free the subtree starting from *@top
4315 * b) free the subtrees whose roots are stored in
4316 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
4317 * c) free the subtrees growing from the inode past the @chain[0].
4318 * (no partially truncated stuff there). */
4320 static Indirect *ext4_find_shared(struct inode *inode, int depth,
4321 ext4_lblk_t offsets[4], Indirect chain[4],
4324 Indirect *partial, *p;
4328 /* Make k index the deepest non-null offset + 1 */
4329 for (k = depth; k > 1 && !offsets[k-1]; k--)
4331 partial = ext4_get_branch(inode, k, offsets, chain, &err);
4332 /* Writer: pointers */
4334 partial = chain + k-1;
4336 * If the branch acquired continuation since we've looked at it -
4337 * fine, it should all survive and (new) top doesn't belong to us.
4339 if (!partial->key && *partial->p)
4342 for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
4345 * OK, we've found the last block that must survive. The rest of our
4346 * branch should be detached before unlocking. However, if that rest
4347 * of branch is all ours and does not grow immediately from the inode
4348 * it's easier to cheat and just decrement partial->p.
4350 if (p == chain + k - 1 && p > chain) {
4354 /* Nope, don't do this in ext4. Must leave the tree intact */
4361 while (partial > p) {
4362 brelse(partial->bh);
4370 * Zero a number of block pointers in either an inode or an indirect block.
4371 * If we restart the transaction we must again get write access to the
4372 * indirect block for further modification.
4374 * We release `count' blocks on disk, but (last - first) may be greater
4375 * than `count' because there can be holes in there.
4377 static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
4378 struct buffer_head *bh,
4379 ext4_fsblk_t block_to_free,
4380 unsigned long count, __le32 *first,
4384 int flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED;
4386 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
4387 flags |= EXT4_FREE_BLOCKS_METADATA;
4389 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free,
4391 EXT4_ERROR_INODE(inode, "attempt to clear invalid "
4392 "blocks %llu len %lu",
4393 (unsigned long long) block_to_free, count);
4397 if (try_to_extend_transaction(handle, inode)) {
4399 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4400 ext4_handle_dirty_metadata(handle, inode, bh);
4402 ext4_mark_inode_dirty(handle, inode);
4403 ext4_truncate_restart_trans(handle, inode,
4404 blocks_for_truncate(inode));
4406 BUFFER_TRACE(bh, "retaking write access");
4407 ext4_journal_get_write_access(handle, bh);
4411 for (p = first; p < last; p++)
4414 ext4_free_blocks(handle, inode, 0, block_to_free, count, flags);
4419 * ext4_free_data - free a list of data blocks
4420 * @handle: handle for this transaction
4421 * @inode: inode we are dealing with
4422 * @this_bh: indirect buffer_head which contains *@first and *@last
4423 * @first: array of block numbers
4424 * @last: points immediately past the end of array
4426 * We are freeing all blocks refered from that array (numbers are stored as
4427 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
4429 * We accumulate contiguous runs of blocks to free. Conveniently, if these
4430 * blocks are contiguous then releasing them at one time will only affect one
4431 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
4432 * actually use a lot of journal space.
4434 * @this_bh will be %NULL if @first and @last point into the inode's direct
4437 static void ext4_free_data(handle_t *handle, struct inode *inode,
4438 struct buffer_head *this_bh,
4439 __le32 *first, __le32 *last)
4441 ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */
4442 unsigned long count = 0; /* Number of blocks in the run */
4443 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
4446 ext4_fsblk_t nr; /* Current block # */
4447 __le32 *p; /* Pointer into inode/ind
4448 for current block */
4451 if (this_bh) { /* For indirect block */
4452 BUFFER_TRACE(this_bh, "get_write_access");
4453 err = ext4_journal_get_write_access(handle, this_bh);
4454 /* Important: if we can't update the indirect pointers
4455 * to the blocks, we can't free them. */
4460 for (p = first; p < last; p++) {
4461 nr = le32_to_cpu(*p);
4463 /* accumulate blocks to free if they're contiguous */
4466 block_to_free_p = p;
4468 } else if (nr == block_to_free + count) {
4471 if (ext4_clear_blocks(handle, inode, this_bh,
4472 block_to_free, count,
4473 block_to_free_p, p))
4476 block_to_free_p = p;
4483 ext4_clear_blocks(handle, inode, this_bh, block_to_free,
4484 count, block_to_free_p, p);
4487 BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
4490 * The buffer head should have an attached journal head at this
4491 * point. However, if the data is corrupted and an indirect
4492 * block pointed to itself, it would have been detached when
4493 * the block was cleared. Check for this instead of OOPSing.
4495 if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
4496 ext4_handle_dirty_metadata(handle, inode, this_bh);
4498 EXT4_ERROR_INODE(inode,
4499 "circular indirect block detected at "
4501 (unsigned long long) this_bh->b_blocknr);
4506 * ext4_free_branches - free an array of branches
4507 * @handle: JBD handle for this transaction
4508 * @inode: inode we are dealing with
4509 * @parent_bh: the buffer_head which contains *@first and *@last
4510 * @first: array of block numbers
4511 * @last: pointer immediately past the end of array
4512 * @depth: depth of the branches to free
4514 * We are freeing all blocks refered from these branches (numbers are
4515 * stored as little-endian 32-bit) and updating @inode->i_blocks
4518 static void ext4_free_branches(handle_t *handle, struct inode *inode,
4519 struct buffer_head *parent_bh,
4520 __le32 *first, __le32 *last, int depth)
4525 if (ext4_handle_is_aborted(handle))
4529 struct buffer_head *bh;
4530 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
4532 while (--p >= first) {
4533 nr = le32_to_cpu(*p);
4535 continue; /* A hole */
4537 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb),
4539 EXT4_ERROR_INODE(inode,
4540 "invalid indirect mapped "
4541 "block %lu (level %d)",
4542 (unsigned long) nr, depth);
4546 /* Go read the buffer for the next level down */
4547 bh = sb_bread(inode->i_sb, nr);
4550 * A read failure? Report error and clear slot
4554 EXT4_ERROR_INODE_BLOCK(inode, nr,
4559 /* This zaps the entire block. Bottom up. */
4560 BUFFER_TRACE(bh, "free child branches");
4561 ext4_free_branches(handle, inode, bh,
4562 (__le32 *) bh->b_data,
4563 (__le32 *) bh->b_data + addr_per_block,
4567 * Everything below this this pointer has been
4568 * released. Now let this top-of-subtree go.
4570 * We want the freeing of this indirect block to be
4571 * atomic in the journal with the updating of the
4572 * bitmap block which owns it. So make some room in
4575 * We zero the parent pointer *after* freeing its
4576 * pointee in the bitmaps, so if extend_transaction()
4577 * for some reason fails to put the bitmap changes and
4578 * the release into the same transaction, recovery
4579 * will merely complain about releasing a free block,
4580 * rather than leaking blocks.
4582 if (ext4_handle_is_aborted(handle))
4584 if (try_to_extend_transaction(handle, inode)) {
4585 ext4_mark_inode_dirty(handle, inode);
4586 ext4_truncate_restart_trans(handle, inode,
4587 blocks_for_truncate(inode));
4591 * The forget flag here is critical because if
4592 * we are journaling (and not doing data
4593 * journaling), we have to make sure a revoke
4594 * record is written to prevent the journal
4595 * replay from overwriting the (former)
4596 * indirect block if it gets reallocated as a
4597 * data block. This must happen in the same
4598 * transaction where the data blocks are
4601 ext4_free_blocks(handle, inode, 0, nr, 1,
4602 EXT4_FREE_BLOCKS_METADATA|
4603 EXT4_FREE_BLOCKS_FORGET);
4607 * The block which we have just freed is
4608 * pointed to by an indirect block: journal it
4610 BUFFER_TRACE(parent_bh, "get_write_access");
4611 if (!ext4_journal_get_write_access(handle,
4614 BUFFER_TRACE(parent_bh,
4615 "call ext4_handle_dirty_metadata");
4616 ext4_handle_dirty_metadata(handle,
4623 /* We have reached the bottom of the tree. */
4624 BUFFER_TRACE(parent_bh, "free data blocks");
4625 ext4_free_data(handle, inode, parent_bh, first, last);
4629 int ext4_can_truncate(struct inode *inode)
4631 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4633 if (S_ISREG(inode->i_mode))
4635 if (S_ISDIR(inode->i_mode))
4637 if (S_ISLNK(inode->i_mode))
4638 return !ext4_inode_is_fast_symlink(inode);
4645 * We block out ext4_get_block() block instantiations across the entire
4646 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4647 * simultaneously on behalf of the same inode.
4649 * As we work through the truncate and commmit bits of it to the journal there
4650 * is one core, guiding principle: the file's tree must always be consistent on
4651 * disk. We must be able to restart the truncate after a crash.
4653 * The file's tree may be transiently inconsistent in memory (although it
4654 * probably isn't), but whenever we close off and commit a journal transaction,
4655 * the contents of (the filesystem + the journal) must be consistent and
4656 * restartable. It's pretty simple, really: bottom up, right to left (although
4657 * left-to-right works OK too).
4659 * Note that at recovery time, journal replay occurs *before* the restart of
4660 * truncate against the orphan inode list.
4662 * The committed inode has the new, desired i_size (which is the same as
4663 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4664 * that this inode's truncate did not complete and it will again call
4665 * ext4_truncate() to have another go. So there will be instantiated blocks
4666 * to the right of the truncation point in a crashed ext4 filesystem. But
4667 * that's fine - as long as they are linked from the inode, the post-crash
4668 * ext4_truncate() run will find them and release them.
4670 void ext4_truncate(struct inode *inode)
4673 struct ext4_inode_info *ei = EXT4_I(inode);
4674 __le32 *i_data = ei->i_data;
4675 int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
4676 struct address_space *mapping = inode->i_mapping;
4677 ext4_lblk_t offsets[4];
4682 ext4_lblk_t last_block;
4683 unsigned blocksize = inode->i_sb->s_blocksize;
4685 if (!ext4_can_truncate(inode))
4688 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4690 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
4691 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
4693 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
4694 ext4_ext_truncate(inode);
4698 handle = start_transaction(inode);
4700 return; /* AKPM: return what? */
4702 last_block = (inode->i_size + blocksize-1)
4703 >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
4705 if (inode->i_size & (blocksize - 1))
4706 if (ext4_block_truncate_page(handle, mapping, inode->i_size))
4709 n = ext4_block_to_path(inode, last_block, offsets, NULL);
4711 goto out_stop; /* error */
4714 * OK. This truncate is going to happen. We add the inode to the
4715 * orphan list, so that if this truncate spans multiple transactions,
4716 * and we crash, we will resume the truncate when the filesystem
4717 * recovers. It also marks the inode dirty, to catch the new size.
4719 * Implication: the file must always be in a sane, consistent
4720 * truncatable state while each transaction commits.
4722 if (ext4_orphan_add(handle, inode))
4726 * From here we block out all ext4_get_block() callers who want to
4727 * modify the block allocation tree.
4729 down_write(&ei->i_data_sem);
4731 ext4_discard_preallocations(inode);
4734 * The orphan list entry will now protect us from any crash which
4735 * occurs before the truncate completes, so it is now safe to propagate
4736 * the new, shorter inode size (held for now in i_size) into the
4737 * on-disk inode. We do this via i_disksize, which is the value which
4738 * ext4 *really* writes onto the disk inode.
4740 ei->i_disksize = inode->i_size;
4742 if (n == 1) { /* direct blocks */
4743 ext4_free_data(handle, inode, NULL, i_data+offsets[0],
4744 i_data + EXT4_NDIR_BLOCKS);
4748 partial = ext4_find_shared(inode, n, offsets, chain, &nr);
4749 /* Kill the top of shared branch (not detached) */
4751 if (partial == chain) {
4752 /* Shared branch grows from the inode */
4753 ext4_free_branches(handle, inode, NULL,
4754 &nr, &nr+1, (chain+n-1) - partial);
4757 * We mark the inode dirty prior to restart,
4758 * and prior to stop. No need for it here.
4761 /* Shared branch grows from an indirect block */
4762 BUFFER_TRACE(partial->bh, "get_write_access");
4763 ext4_free_branches(handle, inode, partial->bh,
4765 partial->p+1, (chain+n-1) - partial);
4768 /* Clear the ends of indirect blocks on the shared branch */
4769 while (partial > chain) {
4770 ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
4771 (__le32*)partial->bh->b_data+addr_per_block,
4772 (chain+n-1) - partial);
4773 BUFFER_TRACE(partial->bh, "call brelse");
4774 brelse(partial->bh);
4778 /* Kill the remaining (whole) subtrees */
4779 switch (offsets[0]) {
4781 nr = i_data[EXT4_IND_BLOCK];
4783 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
4784 i_data[EXT4_IND_BLOCK] = 0;
4786 case EXT4_IND_BLOCK:
4787 nr = i_data[EXT4_DIND_BLOCK];
4789 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
4790 i_data[EXT4_DIND_BLOCK] = 0;
4792 case EXT4_DIND_BLOCK:
4793 nr = i_data[EXT4_TIND_BLOCK];
4795 ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
4796 i_data[EXT4_TIND_BLOCK] = 0;
4798 case EXT4_TIND_BLOCK:
4802 up_write(&ei->i_data_sem);
4803 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4804 ext4_mark_inode_dirty(handle, inode);
4807 * In a multi-transaction truncate, we only make the final transaction
4811 ext4_handle_sync(handle);
4814 * If this was a simple ftruncate(), and the file will remain alive
4815 * then we need to clear up the orphan record which we created above.
4816 * However, if this was a real unlink then we were called by
4817 * ext4_delete_inode(), and we allow that function to clean up the
4818 * orphan info for us.
4821 ext4_orphan_del(handle, inode);
4823 ext4_journal_stop(handle);
4827 * ext4_get_inode_loc returns with an extra refcount against the inode's
4828 * underlying buffer_head on success. If 'in_mem' is true, we have all
4829 * data in memory that is needed to recreate the on-disk version of this
4832 static int __ext4_get_inode_loc(struct inode *inode,
4833 struct ext4_iloc *iloc, int in_mem)
4835 struct ext4_group_desc *gdp;
4836 struct buffer_head *bh;
4837 struct super_block *sb = inode->i_sb;
4839 int inodes_per_block, inode_offset;
4842 if (!ext4_valid_inum(sb, inode->i_ino))
4845 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
4846 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
4851 * Figure out the offset within the block group inode table
4853 inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb));
4854 inode_offset = ((inode->i_ino - 1) %
4855 EXT4_INODES_PER_GROUP(sb));
4856 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
4857 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
4859 bh = sb_getblk(sb, block);
4861 EXT4_ERROR_INODE_BLOCK(inode, block,
4862 "unable to read itable block");
4865 if (!buffer_uptodate(bh)) {
4869 * If the buffer has the write error flag, we have failed
4870 * to write out another inode in the same block. In this
4871 * case, we don't have to read the block because we may
4872 * read the old inode data successfully.
4874 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
4875 set_buffer_uptodate(bh);
4877 if (buffer_uptodate(bh)) {
4878 /* someone brought it uptodate while we waited */
4884 * If we have all information of the inode in memory and this
4885 * is the only valid inode in the block, we need not read the
4889 struct buffer_head *bitmap_bh;
4892 start = inode_offset & ~(inodes_per_block - 1);
4894 /* Is the inode bitmap in cache? */
4895 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
4900 * If the inode bitmap isn't in cache then the
4901 * optimisation may end up performing two reads instead
4902 * of one, so skip it.
4904 if (!buffer_uptodate(bitmap_bh)) {
4908 for (i = start; i < start + inodes_per_block; i++) {
4909 if (i == inode_offset)
4911 if (ext4_test_bit(i, bitmap_bh->b_data))
4915 if (i == start + inodes_per_block) {
4916 /* all other inodes are free, so skip I/O */
4917 memset(bh->b_data, 0, bh->b_size);
4918 set_buffer_uptodate(bh);
4926 * If we need to do any I/O, try to pre-readahead extra
4927 * blocks from the inode table.
4929 if (EXT4_SB(sb)->s_inode_readahead_blks) {
4930 ext4_fsblk_t b, end, table;
4933 table = ext4_inode_table(sb, gdp);
4934 /* s_inode_readahead_blks is always a power of 2 */
4935 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
4938 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
4939 num = EXT4_INODES_PER_GROUP(sb);
4940 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4941 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
4942 num -= ext4_itable_unused_count(sb, gdp);
4943 table += num / inodes_per_block;
4947 sb_breadahead(sb, b++);
4951 * There are other valid inodes in the buffer, this inode
4952 * has in-inode xattrs, or we don't have this inode in memory.
4953 * Read the block from disk.
4956 bh->b_end_io = end_buffer_read_sync;
4957 submit_bh(READ_META, bh);
4959 if (!buffer_uptodate(bh)) {
4960 EXT4_ERROR_INODE_BLOCK(inode, block,
4961 "unable to read itable block");
4971 int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
4973 /* We have all inode data except xattrs in memory here. */
4974 return __ext4_get_inode_loc(inode, iloc,
4975 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
4978 void ext4_set_inode_flags(struct inode *inode)
4980 unsigned int flags = EXT4_I(inode)->i_flags;
4982 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
4983 if (flags & EXT4_SYNC_FL)
4984 inode->i_flags |= S_SYNC;
4985 if (flags & EXT4_APPEND_FL)
4986 inode->i_flags |= S_APPEND;
4987 if (flags & EXT4_IMMUTABLE_FL)
4988 inode->i_flags |= S_IMMUTABLE;
4989 if (flags & EXT4_NOATIME_FL)
4990 inode->i_flags |= S_NOATIME;
4991 if (flags & EXT4_DIRSYNC_FL)
4992 inode->i_flags |= S_DIRSYNC;
4995 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
4996 void ext4_get_inode_flags(struct ext4_inode_info *ei)
4998 unsigned int vfs_fl;
4999 unsigned long old_fl, new_fl;
5002 vfs_fl = ei->vfs_inode.i_flags;
5003 old_fl = ei->i_flags;
5004 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
5005 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
5007 if (vfs_fl & S_SYNC)
5008 new_fl |= EXT4_SYNC_FL;
5009 if (vfs_fl & S_APPEND)
5010 new_fl |= EXT4_APPEND_FL;
5011 if (vfs_fl & S_IMMUTABLE)
5012 new_fl |= EXT4_IMMUTABLE_FL;
5013 if (vfs_fl & S_NOATIME)
5014 new_fl |= EXT4_NOATIME_FL;
5015 if (vfs_fl & S_DIRSYNC)
5016 new_fl |= EXT4_DIRSYNC_FL;
5017 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
5020 static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
5021 struct ext4_inode_info *ei)
5024 struct inode *inode = &(ei->vfs_inode);
5025 struct super_block *sb = inode->i_sb;
5027 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
5028 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
5029 /* we are using combined 48 bit field */
5030 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
5031 le32_to_cpu(raw_inode->i_blocks_lo);
5032 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
5033 /* i_blocks represent file system block size */
5034 return i_blocks << (inode->i_blkbits - 9);
5039 return le32_to_cpu(raw_inode->i_blocks_lo);
5043 struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
5045 struct ext4_iloc iloc;
5046 struct ext4_inode *raw_inode;
5047 struct ext4_inode_info *ei;
5048 struct inode *inode;
5049 journal_t *journal = EXT4_SB(sb)->s_journal;
5053 inode = iget_locked(sb, ino);
5055 return ERR_PTR(-ENOMEM);
5056 if (!(inode->i_state & I_NEW))
5062 ret = __ext4_get_inode_loc(inode, &iloc, 0);
5065 raw_inode = ext4_raw_inode(&iloc);
5066 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
5067 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
5068 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
5069 if (!(test_opt(inode->i_sb, NO_UID32))) {
5070 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
5071 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
5073 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
5075 ei->i_state_flags = 0;
5076 ei->i_dir_start_lookup = 0;
5077 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
5078 /* We now have enough fields to check if the inode was active or not.
5079 * This is needed because nfsd might try to access dead inodes
5080 * the test is that same one that e2fsck uses
5081 * NeilBrown 1999oct15
5083 if (inode->i_nlink == 0) {
5084 if (inode->i_mode == 0 ||
5085 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
5086 /* this inode is deleted */
5090 /* The only unlinked inodes we let through here have
5091 * valid i_mode and are being read by the orphan
5092 * recovery code: that's fine, we're about to complete
5093 * the process of deleting those. */
5095 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
5096 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
5097 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
5098 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
5100 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
5101 inode->i_size = ext4_isize(raw_inode);
5102 ei->i_disksize = inode->i_size;
5104 ei->i_reserved_quota = 0;
5106 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
5107 ei->i_block_group = iloc.block_group;
5108 ei->i_last_alloc_group = ~0;
5110 * NOTE! The in-memory inode i_data array is in little-endian order
5111 * even on big-endian machines: we do NOT byteswap the block numbers!
5113 for (block = 0; block < EXT4_N_BLOCKS; block++)
5114 ei->i_data[block] = raw_inode->i_block[block];
5115 INIT_LIST_HEAD(&ei->i_orphan);
5118 * Set transaction id's of transactions that have to be committed
5119 * to finish f[data]sync. We set them to currently running transaction
5120 * as we cannot be sure that the inode or some of its metadata isn't
5121 * part of the transaction - the inode could have been reclaimed and
5122 * now it is reread from disk.
5125 transaction_t *transaction;
5128 read_lock(&journal->j_state_lock);
5129 if (journal->j_running_transaction)
5130 transaction = journal->j_running_transaction;
5132 transaction = journal->j_committing_transaction;
5134 tid = transaction->t_tid;
5136 tid = journal->j_commit_sequence;
5137 read_unlock(&journal->j_state_lock);
5138 ei->i_sync_tid = tid;
5139 ei->i_datasync_tid = tid;
5142 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
5143 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
5144 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
5145 EXT4_INODE_SIZE(inode->i_sb)) {
5149 if (ei->i_extra_isize == 0) {
5150 /* The extra space is currently unused. Use it. */
5151 ei->i_extra_isize = sizeof(struct ext4_inode) -
5152 EXT4_GOOD_OLD_INODE_SIZE;
5154 __le32 *magic = (void *)raw_inode +
5155 EXT4_GOOD_OLD_INODE_SIZE +
5157 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
5158 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
5161 ei->i_extra_isize = 0;
5163 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
5164 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
5165 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
5166 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
5168 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
5169 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
5170 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
5172 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
5176 if (ei->i_file_acl &&
5177 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
5178 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
5182 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5183 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
5184 (S_ISLNK(inode->i_mode) &&
5185 !ext4_inode_is_fast_symlink(inode)))
5186 /* Validate extent which is part of inode */
5187 ret = ext4_ext_check_inode(inode);
5188 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
5189 (S_ISLNK(inode->i_mode) &&
5190 !ext4_inode_is_fast_symlink(inode))) {
5191 /* Validate block references which are part of inode */
5192 ret = ext4_check_inode_blockref(inode);
5197 if (S_ISREG(inode->i_mode)) {
5198 inode->i_op = &ext4_file_inode_operations;
5199 inode->i_fop = &ext4_file_operations;
5200 ext4_set_aops(inode);
5201 } else if (S_ISDIR(inode->i_mode)) {
5202 inode->i_op = &ext4_dir_inode_operations;
5203 inode->i_fop = &ext4_dir_operations;
5204 } else if (S_ISLNK(inode->i_mode)) {
5205 if (ext4_inode_is_fast_symlink(inode)) {
5206 inode->i_op = &ext4_fast_symlink_inode_operations;
5207 nd_terminate_link(ei->i_data, inode->i_size,
5208 sizeof(ei->i_data) - 1);
5210 inode->i_op = &ext4_symlink_inode_operations;
5211 ext4_set_aops(inode);
5213 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
5214 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
5215 inode->i_op = &ext4_special_inode_operations;
5216 if (raw_inode->i_block[0])
5217 init_special_inode(inode, inode->i_mode,
5218 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
5220 init_special_inode(inode, inode->i_mode,
5221 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
5224 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
5228 ext4_set_inode_flags(inode);
5229 unlock_new_inode(inode);
5235 return ERR_PTR(ret);
5238 static int ext4_inode_blocks_set(handle_t *handle,
5239 struct ext4_inode *raw_inode,
5240 struct ext4_inode_info *ei)
5242 struct inode *inode = &(ei->vfs_inode);
5243 u64 i_blocks = inode->i_blocks;
5244 struct super_block *sb = inode->i_sb;
5246 if (i_blocks <= ~0U) {
5248 * i_blocks can be represnted in a 32 bit variable
5249 * as multiple of 512 bytes
5251 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
5252 raw_inode->i_blocks_high = 0;
5253 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
5256 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
5259 if (i_blocks <= 0xffffffffffffULL) {
5261 * i_blocks can be represented in a 48 bit variable
5262 * as multiple of 512 bytes
5264 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
5265 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
5266 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
5268 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
5269 /* i_block is stored in file system block size */
5270 i_blocks = i_blocks >> (inode->i_blkbits - 9);
5271 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
5272 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
5278 * Post the struct inode info into an on-disk inode location in the
5279 * buffer-cache. This gobbles the caller's reference to the
5280 * buffer_head in the inode location struct.
5282 * The caller must have write access to iloc->bh.
5284 static int ext4_do_update_inode(handle_t *handle,
5285 struct inode *inode,
5286 struct ext4_iloc *iloc)
5288 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
5289 struct ext4_inode_info *ei = EXT4_I(inode);
5290 struct buffer_head *bh = iloc->bh;
5291 int err = 0, rc, block;
5293 /* For fields not not tracking in the in-memory inode,
5294 * initialise them to zero for new inodes. */
5295 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
5296 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
5298 ext4_get_inode_flags(ei);
5299 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
5300 if (!(test_opt(inode->i_sb, NO_UID32))) {
5301 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
5302 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
5304 * Fix up interoperability with old kernels. Otherwise, old inodes get
5305 * re-used with the upper 16 bits of the uid/gid intact
5308 raw_inode->i_uid_high =
5309 cpu_to_le16(high_16_bits(inode->i_uid));
5310 raw_inode->i_gid_high =
5311 cpu_to_le16(high_16_bits(inode->i_gid));
5313 raw_inode->i_uid_high = 0;
5314 raw_inode->i_gid_high = 0;
5317 raw_inode->i_uid_low =
5318 cpu_to_le16(fs_high2lowuid(inode->i_uid));
5319 raw_inode->i_gid_low =
5320 cpu_to_le16(fs_high2lowgid(inode->i_gid));
5321 raw_inode->i_uid_high = 0;
5322 raw_inode->i_gid_high = 0;
5324 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
5326 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
5327 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
5328 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
5329 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
5331 if (ext4_inode_blocks_set(handle, raw_inode, ei))
5333 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
5334 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
5335 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
5336 cpu_to_le32(EXT4_OS_HURD))
5337 raw_inode->i_file_acl_high =
5338 cpu_to_le16(ei->i_file_acl >> 32);
5339 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
5340 ext4_isize_set(raw_inode, ei->i_disksize);
5341 if (ei->i_disksize > 0x7fffffffULL) {
5342 struct super_block *sb = inode->i_sb;
5343 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
5344 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
5345 EXT4_SB(sb)->s_es->s_rev_level ==
5346 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
5347 /* If this is the first large file
5348 * created, add a flag to the superblock.
5350 err = ext4_journal_get_write_access(handle,
5351 EXT4_SB(sb)->s_sbh);
5354 ext4_update_dynamic_rev(sb);
5355 EXT4_SET_RO_COMPAT_FEATURE(sb,
5356 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
5358 ext4_handle_sync(handle);
5359 err = ext4_handle_dirty_metadata(handle, NULL,
5360 EXT4_SB(sb)->s_sbh);
5363 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
5364 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
5365 if (old_valid_dev(inode->i_rdev)) {
5366 raw_inode->i_block[0] =
5367 cpu_to_le32(old_encode_dev(inode->i_rdev));
5368 raw_inode->i_block[1] = 0;
5370 raw_inode->i_block[0] = 0;
5371 raw_inode->i_block[1] =
5372 cpu_to_le32(new_encode_dev(inode->i_rdev));
5373 raw_inode->i_block[2] = 0;
5376 for (block = 0; block < EXT4_N_BLOCKS; block++)
5377 raw_inode->i_block[block] = ei->i_data[block];
5379 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
5380 if (ei->i_extra_isize) {
5381 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
5382 raw_inode->i_version_hi =
5383 cpu_to_le32(inode->i_version >> 32);
5384 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
5387 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
5388 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
5391 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
5393 ext4_update_inode_fsync_trans(handle, inode, 0);
5396 ext4_std_error(inode->i_sb, err);
5401 * ext4_write_inode()
5403 * We are called from a few places:
5405 * - Within generic_file_write() for O_SYNC files.
5406 * Here, there will be no transaction running. We wait for any running
5407 * trasnaction to commit.
5409 * - Within sys_sync(), kupdate and such.
5410 * We wait on commit, if tol to.
5412 * - Within prune_icache() (PF_MEMALLOC == true)
5413 * Here we simply return. We can't afford to block kswapd on the
5416 * In all cases it is actually safe for us to return without doing anything,
5417 * because the inode has been copied into a raw inode buffer in
5418 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
5421 * Note that we are absolutely dependent upon all inode dirtiers doing the
5422 * right thing: they *must* call mark_inode_dirty() after dirtying info in
5423 * which we are interested.
5425 * It would be a bug for them to not do this. The code:
5427 * mark_inode_dirty(inode)
5429 * inode->i_size = expr;
5431 * is in error because a kswapd-driven write_inode() could occur while
5432 * `stuff()' is running, and the new i_size will be lost. Plus the inode
5433 * will no longer be on the superblock's dirty inode list.
5435 int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
5439 if (current->flags & PF_MEMALLOC)
5442 if (EXT4_SB(inode->i_sb)->s_journal) {
5443 if (ext4_journal_current_handle()) {
5444 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
5449 if (wbc->sync_mode != WB_SYNC_ALL)
5452 err = ext4_force_commit(inode->i_sb);
5454 struct ext4_iloc iloc;
5456 err = __ext4_get_inode_loc(inode, &iloc, 0);
5459 if (wbc->sync_mode == WB_SYNC_ALL)
5460 sync_dirty_buffer(iloc.bh);
5461 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
5462 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
5463 "IO error syncing inode");
5474 * Called from notify_change.
5476 * We want to trap VFS attempts to truncate the file as soon as
5477 * possible. In particular, we want to make sure that when the VFS
5478 * shrinks i_size, we put the inode on the orphan list and modify
5479 * i_disksize immediately, so that during the subsequent flushing of
5480 * dirty pages and freeing of disk blocks, we can guarantee that any
5481 * commit will leave the blocks being flushed in an unused state on
5482 * disk. (On recovery, the inode will get truncated and the blocks will
5483 * be freed, so we have a strong guarantee that no future commit will
5484 * leave these blocks visible to the user.)
5486 * Another thing we have to assure is that if we are in ordered mode
5487 * and inode is still attached to the committing transaction, we must
5488 * we start writeout of all the dirty pages which are being truncated.
5489 * This way we are sure that all the data written in the previous
5490 * transaction are already on disk (truncate waits for pages under
5493 * Called with inode->i_mutex down.
5495 int ext4_setattr(struct dentry *dentry, struct iattr *attr)
5497 struct inode *inode = dentry->d_inode;
5499 const unsigned int ia_valid = attr->ia_valid;
5501 error = inode_change_ok(inode, attr);
5505 if (is_quota_modification(inode, attr))
5506 dquot_initialize(inode);
5507 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
5508 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
5511 /* (user+group)*(old+new) structure, inode write (sb,
5512 * inode block, ? - but truncate inode update has it) */
5513 handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
5514 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3);
5515 if (IS_ERR(handle)) {
5516 error = PTR_ERR(handle);
5519 error = dquot_transfer(inode, attr);
5521 ext4_journal_stop(handle);
5524 /* Update corresponding info in inode so that everything is in
5525 * one transaction */
5526 if (attr->ia_valid & ATTR_UID)
5527 inode->i_uid = attr->ia_uid;
5528 if (attr->ia_valid & ATTR_GID)
5529 inode->i_gid = attr->ia_gid;
5530 error = ext4_mark_inode_dirty(handle, inode);
5531 ext4_journal_stop(handle);
5534 if (attr->ia_valid & ATTR_SIZE) {
5535 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
5536 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5538 if (attr->ia_size > sbi->s_bitmap_maxbytes)
5543 if (S_ISREG(inode->i_mode) &&
5544 attr->ia_valid & ATTR_SIZE &&
5545 (attr->ia_size < inode->i_size ||
5546 (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))) {
5549 handle = ext4_journal_start(inode, 3);
5550 if (IS_ERR(handle)) {
5551 error = PTR_ERR(handle);
5555 error = ext4_orphan_add(handle, inode);
5556 EXT4_I(inode)->i_disksize = attr->ia_size;
5557 rc = ext4_mark_inode_dirty(handle, inode);
5560 ext4_journal_stop(handle);
5562 if (ext4_should_order_data(inode)) {
5563 error = ext4_begin_ordered_truncate(inode,
5566 /* Do as much error cleanup as possible */
5567 handle = ext4_journal_start(inode, 3);
5568 if (IS_ERR(handle)) {
5569 ext4_orphan_del(NULL, inode);
5572 ext4_orphan_del(handle, inode);
5573 ext4_journal_stop(handle);
5577 /* ext4_truncate will clear the flag */
5578 if ((ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))
5579 ext4_truncate(inode);
5582 if ((attr->ia_valid & ATTR_SIZE) &&
5583 attr->ia_size != i_size_read(inode))
5584 rc = vmtruncate(inode, attr->ia_size);
5587 setattr_copy(inode, attr);
5588 mark_inode_dirty(inode);
5592 * If the call to ext4_truncate failed to get a transaction handle at
5593 * all, we need to clean up the in-core orphan list manually.
5596 ext4_orphan_del(NULL, inode);
5598 if (!rc && (ia_valid & ATTR_MODE))
5599 rc = ext4_acl_chmod(inode);
5602 ext4_std_error(inode->i_sb, error);
5608 int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
5611 struct inode *inode;
5612 unsigned long delalloc_blocks;
5614 inode = dentry->d_inode;
5615 generic_fillattr(inode, stat);
5618 * We can't update i_blocks if the block allocation is delayed
5619 * otherwise in the case of system crash before the real block
5620 * allocation is done, we will have i_blocks inconsistent with
5621 * on-disk file blocks.
5622 * We always keep i_blocks updated together with real
5623 * allocation. But to not confuse with user, stat
5624 * will return the blocks that include the delayed allocation
5625 * blocks for this file.
5627 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
5628 delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
5629 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
5631 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
5635 static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
5640 /* if nrblocks are contiguous */
5643 * With N contiguous data blocks, it need at most
5644 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
5645 * 2 dindirect blocks
5648 indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
5649 return indirects + 3;
5652 * if nrblocks are not contiguous, worse case, each block touch
5653 * a indirect block, and each indirect block touch a double indirect
5654 * block, plus a triple indirect block
5656 indirects = nrblocks * 2 + 1;
5660 static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
5662 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5663 return ext4_indirect_trans_blocks(inode, nrblocks, chunk);
5664 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
5668 * Account for index blocks, block groups bitmaps and block group
5669 * descriptor blocks if modify datablocks and index blocks
5670 * worse case, the indexs blocks spread over different block groups
5672 * If datablocks are discontiguous, they are possible to spread over
5673 * different block groups too. If they are contiuguous, with flexbg,
5674 * they could still across block group boundary.
5676 * Also account for superblock, inode, quota and xattr blocks
5678 int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
5680 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
5686 * How many index blocks need to touch to modify nrblocks?
5687 * The "Chunk" flag indicating whether the nrblocks is
5688 * physically contiguous on disk
5690 * For Direct IO and fallocate, they calls get_block to allocate
5691 * one single extent at a time, so they could set the "Chunk" flag
5693 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
5698 * Now let's see how many group bitmaps and group descriptors need
5708 if (groups > ngroups)
5710 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
5711 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
5713 /* bitmaps and block group descriptor blocks */
5714 ret += groups + gdpblocks;
5716 /* Blocks for super block, inode, quota and xattr blocks */
5717 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
5723 * Calulate the total number of credits to reserve to fit
5724 * the modification of a single pages into a single transaction,
5725 * which may include multiple chunks of block allocations.
5727 * This could be called via ext4_write_begin()
5729 * We need to consider the worse case, when
5730 * one new block per extent.
5732 int ext4_writepage_trans_blocks(struct inode *inode)
5734 int bpp = ext4_journal_blocks_per_page(inode);
5737 ret = ext4_meta_trans_blocks(inode, bpp, 0);
5739 /* Account for data blocks for journalled mode */
5740 if (ext4_should_journal_data(inode))
5746 * Calculate the journal credits for a chunk of data modification.
5748 * This is called from DIO, fallocate or whoever calling
5749 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
5751 * journal buffers for data blocks are not included here, as DIO
5752 * and fallocate do no need to journal data buffers.
5754 int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
5756 return ext4_meta_trans_blocks(inode, nrblocks, 1);
5760 * The caller must have previously called ext4_reserve_inode_write().
5761 * Give this, we know that the caller already has write access to iloc->bh.
5763 int ext4_mark_iloc_dirty(handle_t *handle,
5764 struct inode *inode, struct ext4_iloc *iloc)
5768 if (test_opt(inode->i_sb, I_VERSION))
5769 inode_inc_iversion(inode);
5771 /* the do_update_inode consumes one bh->b_count */
5774 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5775 err = ext4_do_update_inode(handle, inode, iloc);
5781 * On success, We end up with an outstanding reference count against
5782 * iloc->bh. This _must_ be cleaned up later.
5786 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
5787 struct ext4_iloc *iloc)
5791 err = ext4_get_inode_loc(inode, iloc);
5793 BUFFER_TRACE(iloc->bh, "get_write_access");
5794 err = ext4_journal_get_write_access(handle, iloc->bh);
5800 ext4_std_error(inode->i_sb, err);
5805 * Expand an inode by new_extra_isize bytes.
5806 * Returns 0 on success or negative error number on failure.
5808 static int ext4_expand_extra_isize(struct inode *inode,
5809 unsigned int new_extra_isize,
5810 struct ext4_iloc iloc,
5813 struct ext4_inode *raw_inode;
5814 struct ext4_xattr_ibody_header *header;
5816 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
5819 raw_inode = ext4_raw_inode(&iloc);
5821 header = IHDR(inode, raw_inode);
5823 /* No extended attributes present */
5824 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
5825 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
5826 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
5828 EXT4_I(inode)->i_extra_isize = new_extra_isize;
5832 /* try to expand with EAs present */
5833 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
5838 * What we do here is to mark the in-core inode as clean with respect to inode
5839 * dirtiness (it may still be data-dirty).
5840 * This means that the in-core inode may be reaped by prune_icache
5841 * without having to perform any I/O. This is a very good thing,
5842 * because *any* task may call prune_icache - even ones which
5843 * have a transaction open against a different journal.
5845 * Is this cheating? Not really. Sure, we haven't written the
5846 * inode out, but prune_icache isn't a user-visible syncing function.
5847 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5848 * we start and wait on commits.
5850 * Is this efficient/effective? Well, we're being nice to the system
5851 * by cleaning up our inodes proactively so they can be reaped
5852 * without I/O. But we are potentially leaving up to five seconds'
5853 * worth of inodes floating about which prune_icache wants us to
5854 * write out. One way to fix that would be to get prune_icache()
5855 * to do a write_super() to free up some memory. It has the desired
5858 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
5860 struct ext4_iloc iloc;
5861 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5862 static unsigned int mnt_count;
5866 err = ext4_reserve_inode_write(handle, inode, &iloc);
5867 if (ext4_handle_valid(handle) &&
5868 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
5869 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
5871 * We need extra buffer credits since we may write into EA block
5872 * with this same handle. If journal_extend fails, then it will
5873 * only result in a minor loss of functionality for that inode.
5874 * If this is felt to be critical, then e2fsck should be run to
5875 * force a large enough s_min_extra_isize.
5877 if ((jbd2_journal_extend(handle,
5878 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
5879 ret = ext4_expand_extra_isize(inode,
5880 sbi->s_want_extra_isize,
5883 ext4_set_inode_state(inode,
5884 EXT4_STATE_NO_EXPAND);
5886 le16_to_cpu(sbi->s_es->s_mnt_count)) {
5887 ext4_warning(inode->i_sb,
5888 "Unable to expand inode %lu. Delete"
5889 " some EAs or run e2fsck.",
5892 le16_to_cpu(sbi->s_es->s_mnt_count);
5898 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
5903 * ext4_dirty_inode() is called from __mark_inode_dirty()
5905 * We're really interested in the case where a file is being extended.
5906 * i_size has been changed by generic_commit_write() and we thus need
5907 * to include the updated inode in the current transaction.
5909 * Also, dquot_alloc_block() will always dirty the inode when blocks
5910 * are allocated to the file.
5912 * If the inode is marked synchronous, we don't honour that here - doing
5913 * so would cause a commit on atime updates, which we don't bother doing.
5914 * We handle synchronous inodes at the highest possible level.
5916 void ext4_dirty_inode(struct inode *inode)
5920 handle = ext4_journal_start(inode, 2);
5924 ext4_mark_inode_dirty(handle, inode);
5926 ext4_journal_stop(handle);
5933 * Bind an inode's backing buffer_head into this transaction, to prevent
5934 * it from being flushed to disk early. Unlike
5935 * ext4_reserve_inode_write, this leaves behind no bh reference and
5936 * returns no iloc structure, so the caller needs to repeat the iloc
5937 * lookup to mark the inode dirty later.
5939 static int ext4_pin_inode(handle_t *handle, struct inode *inode)
5941 struct ext4_iloc iloc;
5945 err = ext4_get_inode_loc(inode, &iloc);
5947 BUFFER_TRACE(iloc.bh, "get_write_access");
5948 err = jbd2_journal_get_write_access(handle, iloc.bh);
5950 err = ext4_handle_dirty_metadata(handle,
5956 ext4_std_error(inode->i_sb, err);
5961 int ext4_change_inode_journal_flag(struct inode *inode, int val)
5968 * We have to be very careful here: changing a data block's
5969 * journaling status dynamically is dangerous. If we write a
5970 * data block to the journal, change the status and then delete
5971 * that block, we risk forgetting to revoke the old log record
5972 * from the journal and so a subsequent replay can corrupt data.
5973 * So, first we make sure that the journal is empty and that
5974 * nobody is changing anything.
5977 journal = EXT4_JOURNAL(inode);
5980 if (is_journal_aborted(journal))
5983 jbd2_journal_lock_updates(journal);
5984 jbd2_journal_flush(journal);
5987 * OK, there are no updates running now, and all cached data is
5988 * synced to disk. We are now in a completely consistent state
5989 * which doesn't have anything in the journal, and we know that
5990 * no filesystem updates are running, so it is safe to modify
5991 * the inode's in-core data-journaling state flag now.
5995 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5997 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5998 ext4_set_aops(inode);
6000 jbd2_journal_unlock_updates(journal);
6002 /* Finally we can mark the inode as dirty. */
6004 handle = ext4_journal_start(inode, 1);
6006 return PTR_ERR(handle);
6008 err = ext4_mark_inode_dirty(handle, inode);
6009 ext4_handle_sync(handle);
6010 ext4_journal_stop(handle);
6011 ext4_std_error(inode->i_sb, err);
6016 static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
6018 return !buffer_mapped(bh);
6021 int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6023 struct page *page = vmf->page;
6028 struct file *file = vma->vm_file;
6029 struct inode *inode = file->f_path.dentry->d_inode;
6030 struct address_space *mapping = inode->i_mapping;
6033 * Get i_alloc_sem to stop truncates messing with the inode. We cannot
6034 * get i_mutex because we are already holding mmap_sem.
6036 down_read(&inode->i_alloc_sem);
6037 size = i_size_read(inode);
6038 if (page->mapping != mapping || size <= page_offset(page)
6039 || !PageUptodate(page)) {
6040 /* page got truncated from under us? */
6044 if (PageMappedToDisk(page))
6047 if (page->index == size >> PAGE_CACHE_SHIFT)
6048 len = size & ~PAGE_CACHE_MASK;
6050 len = PAGE_CACHE_SIZE;
6054 * return if we have all the buffers mapped. This avoid
6055 * the need to call write_begin/write_end which does a
6056 * journal_start/journal_stop which can block and take
6059 if (page_has_buffers(page)) {
6060 if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
6061 ext4_bh_unmapped)) {
6068 * OK, we need to fill the hole... Do write_begin write_end
6069 * to do block allocation/reservation.We are not holding
6070 * inode.i__mutex here. That allow * parallel write_begin,
6071 * write_end call. lock_page prevent this from happening
6072 * on the same page though
6074 ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
6075 len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
6078 ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
6079 len, len, page, fsdata);
6085 ret = VM_FAULT_SIGBUS;
6086 up_read(&inode->i_alloc_sem);