2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
5 * Architecture independence:
6 * Copyright (c) 2005, Bull S.A.
7 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public Licens
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
24 * Extents support for EXT4
27 * - ext4*_error() should be used in some situations
28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
29 * - smart tree reduction
33 #include <linux/time.h>
34 #include <linux/jbd2.h>
35 #include <linux/highuid.h>
36 #include <linux/pagemap.h>
37 #include <linux/quotaops.h>
38 #include <linux/string.h>
39 #include <linux/slab.h>
40 #include <linux/falloc.h>
41 #include <asm/uaccess.h>
42 #include <linux/fiemap.h>
43 #include "ext4_jbd2.h"
44 #include "ext4_extents.h"
46 #include <trace/events/ext4.h>
49 * used by extent splitting.
51 #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
53 #define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
54 #define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
56 #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
57 #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
59 static __le32 ext4_extent_block_csum(struct inode *inode,
60 struct ext4_extent_header *eh)
62 struct ext4_inode_info *ei = EXT4_I(inode);
63 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
66 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
67 EXT4_EXTENT_TAIL_OFFSET(eh));
68 return cpu_to_le32(csum);
71 static int ext4_extent_block_csum_verify(struct inode *inode,
72 struct ext4_extent_header *eh)
74 struct ext4_extent_tail *et;
76 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
77 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
80 et = find_ext4_extent_tail(eh);
81 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
86 static void ext4_extent_block_csum_set(struct inode *inode,
87 struct ext4_extent_header *eh)
89 struct ext4_extent_tail *et;
91 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
92 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
95 et = find_ext4_extent_tail(eh);
96 et->et_checksum = ext4_extent_block_csum(inode, eh);
99 static int ext4_split_extent(handle_t *handle,
101 struct ext4_ext_path *path,
102 struct ext4_map_blocks *map,
106 static int ext4_split_extent_at(handle_t *handle,
108 struct ext4_ext_path *path,
113 static int ext4_find_delayed_extent(struct inode *inode,
114 struct ext4_ext_cache *newex);
116 static int ext4_ext_truncate_extend_restart(handle_t *handle,
122 if (!ext4_handle_valid(handle))
124 if (handle->h_buffer_credits > needed)
126 err = ext4_journal_extend(handle, needed);
129 err = ext4_truncate_restart_trans(handle, inode, needed);
141 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
142 struct ext4_ext_path *path)
145 /* path points to block */
146 return ext4_journal_get_write_access(handle, path->p_bh);
148 /* path points to leaf/index in inode body */
149 /* we use in-core data, no need to protect them */
159 #define ext4_ext_dirty(handle, inode, path) \
160 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
161 static int __ext4_ext_dirty(const char *where, unsigned int line,
162 handle_t *handle, struct inode *inode,
163 struct ext4_ext_path *path)
167 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
168 /* path points to block */
169 err = __ext4_handle_dirty_metadata(where, line, handle,
172 /* path points to leaf/index in inode body */
173 err = ext4_mark_inode_dirty(handle, inode);
178 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
179 struct ext4_ext_path *path,
183 int depth = path->p_depth;
184 struct ext4_extent *ex;
187 * Try to predict block placement assuming that we are
188 * filling in a file which will eventually be
189 * non-sparse --- i.e., in the case of libbfd writing
190 * an ELF object sections out-of-order but in a way
191 * the eventually results in a contiguous object or
192 * executable file, or some database extending a table
193 * space file. However, this is actually somewhat
194 * non-ideal if we are writing a sparse file such as
195 * qemu or KVM writing a raw image file that is going
196 * to stay fairly sparse, since it will end up
197 * fragmenting the file system's free space. Maybe we
198 * should have some hueristics or some way to allow
199 * userspace to pass a hint to file system,
200 * especially if the latter case turns out to be
203 ex = path[depth].p_ext;
205 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
206 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
208 if (block > ext_block)
209 return ext_pblk + (block - ext_block);
211 return ext_pblk - (ext_block - block);
214 /* it looks like index is empty;
215 * try to find starting block from index itself */
216 if (path[depth].p_bh)
217 return path[depth].p_bh->b_blocknr;
220 /* OK. use inode's group */
221 return ext4_inode_to_goal_block(inode);
225 * Allocation for a meta data block
228 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
229 struct ext4_ext_path *path,
230 struct ext4_extent *ex, int *err, unsigned int flags)
232 ext4_fsblk_t goal, newblock;
234 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
235 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
240 static inline int ext4_ext_space_block(struct inode *inode, int check)
244 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
245 / sizeof(struct ext4_extent);
246 #ifdef AGGRESSIVE_TEST
247 if (!check && size > 6)
253 static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
257 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
258 / sizeof(struct ext4_extent_idx);
259 #ifdef AGGRESSIVE_TEST
260 if (!check && size > 5)
266 static inline int ext4_ext_space_root(struct inode *inode, int check)
270 size = sizeof(EXT4_I(inode)->i_data);
271 size -= sizeof(struct ext4_extent_header);
272 size /= sizeof(struct ext4_extent);
273 #ifdef AGGRESSIVE_TEST
274 if (!check && size > 3)
280 static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
284 size = sizeof(EXT4_I(inode)->i_data);
285 size -= sizeof(struct ext4_extent_header);
286 size /= sizeof(struct ext4_extent_idx);
287 #ifdef AGGRESSIVE_TEST
288 if (!check && size > 4)
295 * Calculate the number of metadata blocks needed
296 * to allocate @blocks
297 * Worse case is one block per extent
299 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
301 struct ext4_inode_info *ei = EXT4_I(inode);
304 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
305 / sizeof(struct ext4_extent_idx));
308 * If the new delayed allocation block is contiguous with the
309 * previous da block, it can share index blocks with the
310 * previous block, so we only need to allocate a new index
311 * block every idxs leaf blocks. At ldxs**2 blocks, we need
312 * an additional index block, and at ldxs**3 blocks, yet
313 * another index blocks.
315 if (ei->i_da_metadata_calc_len &&
316 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
319 if ((ei->i_da_metadata_calc_len % idxs) == 0)
321 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
323 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
325 ei->i_da_metadata_calc_len = 0;
327 ei->i_da_metadata_calc_len++;
328 ei->i_da_metadata_calc_last_lblock++;
333 * In the worst case we need a new set of index blocks at
334 * every level of the inode's extent tree.
336 ei->i_da_metadata_calc_len = 1;
337 ei->i_da_metadata_calc_last_lblock = lblock;
338 return ext_depth(inode) + 1;
342 ext4_ext_max_entries(struct inode *inode, int depth)
346 if (depth == ext_depth(inode)) {
348 max = ext4_ext_space_root(inode, 1);
350 max = ext4_ext_space_root_idx(inode, 1);
353 max = ext4_ext_space_block(inode, 1);
355 max = ext4_ext_space_block_idx(inode, 1);
361 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
363 ext4_fsblk_t block = ext4_ext_pblock(ext);
364 int len = ext4_ext_get_actual_len(ext);
368 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
371 static int ext4_valid_extent_idx(struct inode *inode,
372 struct ext4_extent_idx *ext_idx)
374 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
376 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
379 static int ext4_valid_extent_entries(struct inode *inode,
380 struct ext4_extent_header *eh,
383 unsigned short entries;
384 if (eh->eh_entries == 0)
387 entries = le16_to_cpu(eh->eh_entries);
391 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
393 if (!ext4_valid_extent(inode, ext))
399 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
401 if (!ext4_valid_extent_idx(inode, ext_idx))
410 static int __ext4_ext_check(const char *function, unsigned int line,
411 struct inode *inode, struct ext4_extent_header *eh,
414 const char *error_msg;
417 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
418 error_msg = "invalid magic";
421 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
422 error_msg = "unexpected eh_depth";
425 if (unlikely(eh->eh_max == 0)) {
426 error_msg = "invalid eh_max";
429 max = ext4_ext_max_entries(inode, depth);
430 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
431 error_msg = "too large eh_max";
434 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
435 error_msg = "invalid eh_entries";
438 if (!ext4_valid_extent_entries(inode, eh, depth)) {
439 error_msg = "invalid extent entries";
442 /* Verify checksum on non-root extent tree nodes */
443 if (ext_depth(inode) != depth &&
444 !ext4_extent_block_csum_verify(inode, eh)) {
445 error_msg = "extent tree corrupted";
451 ext4_error_inode(inode, function, line, 0,
452 "bad header/extent: %s - magic %x, "
453 "entries %u, max %u(%u), depth %u(%u)",
454 error_msg, le16_to_cpu(eh->eh_magic),
455 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
456 max, le16_to_cpu(eh->eh_depth), depth);
461 #define ext4_ext_check(inode, eh, depth) \
462 __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
464 int ext4_ext_check_inode(struct inode *inode)
466 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
469 static int __ext4_ext_check_block(const char *function, unsigned int line,
471 struct ext4_extent_header *eh,
473 struct buffer_head *bh)
477 if (buffer_verified(bh))
479 ret = ext4_ext_check(inode, eh, depth);
482 set_buffer_verified(bh);
486 #define ext4_ext_check_block(inode, eh, depth, bh) \
487 __ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
490 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
492 int k, l = path->p_depth;
495 for (k = 0; k <= l; k++, path++) {
497 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
498 ext4_idx_pblock(path->p_idx));
499 } else if (path->p_ext) {
500 ext_debug(" %d:[%d]%d:%llu ",
501 le32_to_cpu(path->p_ext->ee_block),
502 ext4_ext_is_uninitialized(path->p_ext),
503 ext4_ext_get_actual_len(path->p_ext),
504 ext4_ext_pblock(path->p_ext));
511 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
513 int depth = ext_depth(inode);
514 struct ext4_extent_header *eh;
515 struct ext4_extent *ex;
521 eh = path[depth].p_hdr;
522 ex = EXT_FIRST_EXTENT(eh);
524 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
526 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
527 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
528 ext4_ext_is_uninitialized(ex),
529 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
534 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
535 ext4_fsblk_t newblock, int level)
537 int depth = ext_depth(inode);
538 struct ext4_extent *ex;
540 if (depth != level) {
541 struct ext4_extent_idx *idx;
542 idx = path[level].p_idx;
543 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
544 ext_debug("%d: move %d:%llu in new index %llu\n", level,
545 le32_to_cpu(idx->ei_block),
546 ext4_idx_pblock(idx),
554 ex = path[depth].p_ext;
555 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
556 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
557 le32_to_cpu(ex->ee_block),
559 ext4_ext_is_uninitialized(ex),
560 ext4_ext_get_actual_len(ex),
567 #define ext4_ext_show_path(inode, path)
568 #define ext4_ext_show_leaf(inode, path)
569 #define ext4_ext_show_move(inode, path, newblock, level)
572 void ext4_ext_drop_refs(struct ext4_ext_path *path)
574 int depth = path->p_depth;
577 for (i = 0; i <= depth; i++, path++)
585 * ext4_ext_binsearch_idx:
586 * binary search for the closest index of the given block
587 * the header must be checked before calling this
590 ext4_ext_binsearch_idx(struct inode *inode,
591 struct ext4_ext_path *path, ext4_lblk_t block)
593 struct ext4_extent_header *eh = path->p_hdr;
594 struct ext4_extent_idx *r, *l, *m;
597 ext_debug("binsearch for %u(idx): ", block);
599 l = EXT_FIRST_INDEX(eh) + 1;
600 r = EXT_LAST_INDEX(eh);
603 if (block < le32_to_cpu(m->ei_block))
607 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
608 m, le32_to_cpu(m->ei_block),
609 r, le32_to_cpu(r->ei_block));
613 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
614 ext4_idx_pblock(path->p_idx));
616 #ifdef CHECK_BINSEARCH
618 struct ext4_extent_idx *chix, *ix;
621 chix = ix = EXT_FIRST_INDEX(eh);
622 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
624 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
625 printk(KERN_DEBUG "k=%d, ix=0x%p, "
627 ix, EXT_FIRST_INDEX(eh));
628 printk(KERN_DEBUG "%u <= %u\n",
629 le32_to_cpu(ix->ei_block),
630 le32_to_cpu(ix[-1].ei_block));
632 BUG_ON(k && le32_to_cpu(ix->ei_block)
633 <= le32_to_cpu(ix[-1].ei_block));
634 if (block < le32_to_cpu(ix->ei_block))
638 BUG_ON(chix != path->p_idx);
645 * ext4_ext_binsearch:
646 * binary search for closest extent of the given block
647 * the header must be checked before calling this
650 ext4_ext_binsearch(struct inode *inode,
651 struct ext4_ext_path *path, ext4_lblk_t block)
653 struct ext4_extent_header *eh = path->p_hdr;
654 struct ext4_extent *r, *l, *m;
656 if (eh->eh_entries == 0) {
658 * this leaf is empty:
659 * we get such a leaf in split/add case
664 ext_debug("binsearch for %u: ", block);
666 l = EXT_FIRST_EXTENT(eh) + 1;
667 r = EXT_LAST_EXTENT(eh);
671 if (block < le32_to_cpu(m->ee_block))
675 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
676 m, le32_to_cpu(m->ee_block),
677 r, le32_to_cpu(r->ee_block));
681 ext_debug(" -> %d:%llu:[%d]%d ",
682 le32_to_cpu(path->p_ext->ee_block),
683 ext4_ext_pblock(path->p_ext),
684 ext4_ext_is_uninitialized(path->p_ext),
685 ext4_ext_get_actual_len(path->p_ext));
687 #ifdef CHECK_BINSEARCH
689 struct ext4_extent *chex, *ex;
692 chex = ex = EXT_FIRST_EXTENT(eh);
693 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
694 BUG_ON(k && le32_to_cpu(ex->ee_block)
695 <= le32_to_cpu(ex[-1].ee_block));
696 if (block < le32_to_cpu(ex->ee_block))
700 BUG_ON(chex != path->p_ext);
706 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
708 struct ext4_extent_header *eh;
710 eh = ext_inode_hdr(inode);
713 eh->eh_magic = EXT4_EXT_MAGIC;
714 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
715 ext4_mark_inode_dirty(handle, inode);
716 ext4_ext_invalidate_cache(inode);
720 struct ext4_ext_path *
721 ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
722 struct ext4_ext_path *path)
724 struct ext4_extent_header *eh;
725 struct buffer_head *bh;
726 short int depth, i, ppos = 0, alloc = 0;
728 eh = ext_inode_hdr(inode);
729 depth = ext_depth(inode);
731 /* account possible depth increase */
733 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
736 return ERR_PTR(-ENOMEM);
743 /* walk through the tree */
745 ext_debug("depth %d: num %d, max %d\n",
746 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
748 ext4_ext_binsearch_idx(inode, path + ppos, block);
749 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
750 path[ppos].p_depth = i;
751 path[ppos].p_ext = NULL;
753 bh = sb_getblk(inode->i_sb, path[ppos].p_block);
756 if (!bh_uptodate_or_lock(bh)) {
757 trace_ext4_ext_load_extent(inode, block,
759 if (bh_submit_read(bh) < 0) {
764 eh = ext_block_hdr(bh);
766 if (unlikely(ppos > depth)) {
768 EXT4_ERROR_INODE(inode,
769 "ppos %d > depth %d", ppos, depth);
772 path[ppos].p_bh = bh;
773 path[ppos].p_hdr = eh;
776 if (ext4_ext_check_block(inode, eh, i, bh))
780 path[ppos].p_depth = i;
781 path[ppos].p_ext = NULL;
782 path[ppos].p_idx = NULL;
785 ext4_ext_binsearch(inode, path + ppos, block);
786 /* if not an empty leaf */
787 if (path[ppos].p_ext)
788 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
790 ext4_ext_show_path(inode, path);
795 ext4_ext_drop_refs(path);
798 return ERR_PTR(-EIO);
802 * ext4_ext_insert_index:
803 * insert new index [@logical;@ptr] into the block at @curp;
804 * check where to insert: before @curp or after @curp
806 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
807 struct ext4_ext_path *curp,
808 int logical, ext4_fsblk_t ptr)
810 struct ext4_extent_idx *ix;
813 err = ext4_ext_get_access(handle, inode, curp);
817 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
818 EXT4_ERROR_INODE(inode,
819 "logical %d == ei_block %d!",
820 logical, le32_to_cpu(curp->p_idx->ei_block));
824 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
825 >= le16_to_cpu(curp->p_hdr->eh_max))) {
826 EXT4_ERROR_INODE(inode,
827 "eh_entries %d >= eh_max %d!",
828 le16_to_cpu(curp->p_hdr->eh_entries),
829 le16_to_cpu(curp->p_hdr->eh_max));
833 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
835 ext_debug("insert new index %d after: %llu\n", logical, ptr);
836 ix = curp->p_idx + 1;
839 ext_debug("insert new index %d before: %llu\n", logical, ptr);
843 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
846 ext_debug("insert new index %d: "
847 "move %d indices from 0x%p to 0x%p\n",
848 logical, len, ix, ix + 1);
849 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
852 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
853 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
857 ix->ei_block = cpu_to_le32(logical);
858 ext4_idx_store_pblock(ix, ptr);
859 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
861 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
862 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
866 err = ext4_ext_dirty(handle, inode, curp);
867 ext4_std_error(inode->i_sb, err);
874 * inserts new subtree into the path, using free index entry
876 * - allocates all needed blocks (new leaf and all intermediate index blocks)
877 * - makes decision where to split
878 * - moves remaining extents and index entries (right to the split point)
879 * into the newly allocated blocks
880 * - initializes subtree
882 static int ext4_ext_split(handle_t *handle, struct inode *inode,
884 struct ext4_ext_path *path,
885 struct ext4_extent *newext, int at)
887 struct buffer_head *bh = NULL;
888 int depth = ext_depth(inode);
889 struct ext4_extent_header *neh;
890 struct ext4_extent_idx *fidx;
892 ext4_fsblk_t newblock, oldblock;
894 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
897 /* make decision: where to split? */
898 /* FIXME: now decision is simplest: at current extent */
900 /* if current leaf will be split, then we should use
901 * border from split point */
902 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
903 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
906 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
907 border = path[depth].p_ext[1].ee_block;
908 ext_debug("leaf will be split."
909 " next leaf starts at %d\n",
910 le32_to_cpu(border));
912 border = newext->ee_block;
913 ext_debug("leaf will be added."
914 " next leaf starts at %d\n",
915 le32_to_cpu(border));
919 * If error occurs, then we break processing
920 * and mark filesystem read-only. index won't
921 * be inserted and tree will be in consistent
922 * state. Next mount will repair buffers too.
926 * Get array to track all allocated blocks.
927 * We need this to handle errors and free blocks
930 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
934 /* allocate all needed blocks */
935 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
936 for (a = 0; a < depth - at; a++) {
937 newblock = ext4_ext_new_meta_block(handle, inode, path,
938 newext, &err, flags);
941 ablocks[a] = newblock;
944 /* initialize new leaf */
945 newblock = ablocks[--a];
946 if (unlikely(newblock == 0)) {
947 EXT4_ERROR_INODE(inode, "newblock == 0!");
951 bh = sb_getblk(inode->i_sb, newblock);
958 err = ext4_journal_get_create_access(handle, bh);
962 neh = ext_block_hdr(bh);
964 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
965 neh->eh_magic = EXT4_EXT_MAGIC;
968 /* move remainder of path[depth] to the new leaf */
969 if (unlikely(path[depth].p_hdr->eh_entries !=
970 path[depth].p_hdr->eh_max)) {
971 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
972 path[depth].p_hdr->eh_entries,
973 path[depth].p_hdr->eh_max);
977 /* start copy from next extent */
978 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
979 ext4_ext_show_move(inode, path, newblock, depth);
981 struct ext4_extent *ex;
982 ex = EXT_FIRST_EXTENT(neh);
983 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
984 le16_add_cpu(&neh->eh_entries, m);
987 ext4_extent_block_csum_set(inode, neh);
988 set_buffer_uptodate(bh);
991 err = ext4_handle_dirty_metadata(handle, inode, bh);
997 /* correct old leaf */
999 err = ext4_ext_get_access(handle, inode, path + depth);
1002 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1003 err = ext4_ext_dirty(handle, inode, path + depth);
1009 /* create intermediate indexes */
1011 if (unlikely(k < 0)) {
1012 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1017 ext_debug("create %d intermediate indices\n", k);
1018 /* insert new index into current index block */
1019 /* current depth stored in i var */
1022 oldblock = newblock;
1023 newblock = ablocks[--a];
1024 bh = sb_getblk(inode->i_sb, newblock);
1031 err = ext4_journal_get_create_access(handle, bh);
1035 neh = ext_block_hdr(bh);
1036 neh->eh_entries = cpu_to_le16(1);
1037 neh->eh_magic = EXT4_EXT_MAGIC;
1038 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1039 neh->eh_depth = cpu_to_le16(depth - i);
1040 fidx = EXT_FIRST_INDEX(neh);
1041 fidx->ei_block = border;
1042 ext4_idx_store_pblock(fidx, oldblock);
1044 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1045 i, newblock, le32_to_cpu(border), oldblock);
1047 /* move remainder of path[i] to the new index block */
1048 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1049 EXT_LAST_INDEX(path[i].p_hdr))) {
1050 EXT4_ERROR_INODE(inode,
1051 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1052 le32_to_cpu(path[i].p_ext->ee_block));
1056 /* start copy indexes */
1057 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1058 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1059 EXT_MAX_INDEX(path[i].p_hdr));
1060 ext4_ext_show_move(inode, path, newblock, i);
1062 memmove(++fidx, path[i].p_idx,
1063 sizeof(struct ext4_extent_idx) * m);
1064 le16_add_cpu(&neh->eh_entries, m);
1066 ext4_extent_block_csum_set(inode, neh);
1067 set_buffer_uptodate(bh);
1070 err = ext4_handle_dirty_metadata(handle, inode, bh);
1076 /* correct old index */
1078 err = ext4_ext_get_access(handle, inode, path + i);
1081 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1082 err = ext4_ext_dirty(handle, inode, path + i);
1090 /* insert new index */
1091 err = ext4_ext_insert_index(handle, inode, path + at,
1092 le32_to_cpu(border), newblock);
1096 if (buffer_locked(bh))
1102 /* free all allocated blocks in error case */
1103 for (i = 0; i < depth; i++) {
1106 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1107 EXT4_FREE_BLOCKS_METADATA);
1116 * ext4_ext_grow_indepth:
1117 * implements tree growing procedure:
1118 * - allocates new block
1119 * - moves top-level data (index block or leaf) into the new block
1120 * - initializes new top-level, creating index that points to the
1121 * just created block
1123 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1125 struct ext4_extent *newext)
1127 struct ext4_extent_header *neh;
1128 struct buffer_head *bh;
1129 ext4_fsblk_t newblock;
1132 newblock = ext4_ext_new_meta_block(handle, inode, NULL,
1133 newext, &err, flags);
1137 bh = sb_getblk(inode->i_sb, newblock);
1140 ext4_std_error(inode->i_sb, err);
1145 err = ext4_journal_get_create_access(handle, bh);
1151 /* move top-level index/leaf into new block */
1152 memmove(bh->b_data, EXT4_I(inode)->i_data,
1153 sizeof(EXT4_I(inode)->i_data));
1155 /* set size of new block */
1156 neh = ext_block_hdr(bh);
1157 /* old root could have indexes or leaves
1158 * so calculate e_max right way */
1159 if (ext_depth(inode))
1160 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1162 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1163 neh->eh_magic = EXT4_EXT_MAGIC;
1164 ext4_extent_block_csum_set(inode, neh);
1165 set_buffer_uptodate(bh);
1168 err = ext4_handle_dirty_metadata(handle, inode, bh);
1172 /* Update top-level index: num,max,pointer */
1173 neh = ext_inode_hdr(inode);
1174 neh->eh_entries = cpu_to_le16(1);
1175 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1176 if (neh->eh_depth == 0) {
1177 /* Root extent block becomes index block */
1178 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1179 EXT_FIRST_INDEX(neh)->ei_block =
1180 EXT_FIRST_EXTENT(neh)->ee_block;
1182 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1183 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1184 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1185 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1187 le16_add_cpu(&neh->eh_depth, 1);
1188 ext4_mark_inode_dirty(handle, inode);
1196 * ext4_ext_create_new_leaf:
1197 * finds empty index and adds new leaf.
1198 * if no free index is found, then it requests in-depth growing.
1200 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1202 struct ext4_ext_path *path,
1203 struct ext4_extent *newext)
1205 struct ext4_ext_path *curp;
1206 int depth, i, err = 0;
1209 i = depth = ext_depth(inode);
1211 /* walk up to the tree and look for free index entry */
1212 curp = path + depth;
1213 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1218 /* we use already allocated block for index block,
1219 * so subsequent data blocks should be contiguous */
1220 if (EXT_HAS_FREE_INDEX(curp)) {
1221 /* if we found index with free entry, then use that
1222 * entry: create all needed subtree and add new leaf */
1223 err = ext4_ext_split(handle, inode, flags, path, newext, i);
1228 ext4_ext_drop_refs(path);
1229 path = ext4_ext_find_extent(inode,
1230 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1233 err = PTR_ERR(path);
1235 /* tree is full, time to grow in depth */
1236 err = ext4_ext_grow_indepth(handle, inode, flags, newext);
1241 ext4_ext_drop_refs(path);
1242 path = ext4_ext_find_extent(inode,
1243 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1246 err = PTR_ERR(path);
1251 * only first (depth 0 -> 1) produces free space;
1252 * in all other cases we have to split the grown tree
1254 depth = ext_depth(inode);
1255 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1256 /* now we need to split */
1266 * search the closest allocated block to the left for *logical
1267 * and returns it at @logical + it's physical address at @phys
1268 * if *logical is the smallest allocated block, the function
1269 * returns 0 at @phys
1270 * return value contains 0 (success) or error code
1272 static int ext4_ext_search_left(struct inode *inode,
1273 struct ext4_ext_path *path,
1274 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1276 struct ext4_extent_idx *ix;
1277 struct ext4_extent *ex;
1280 if (unlikely(path == NULL)) {
1281 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1284 depth = path->p_depth;
1287 if (depth == 0 && path->p_ext == NULL)
1290 /* usually extent in the path covers blocks smaller
1291 * then *logical, but it can be that extent is the
1292 * first one in the file */
1294 ex = path[depth].p_ext;
1295 ee_len = ext4_ext_get_actual_len(ex);
1296 if (*logical < le32_to_cpu(ex->ee_block)) {
1297 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1298 EXT4_ERROR_INODE(inode,
1299 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1300 *logical, le32_to_cpu(ex->ee_block));
1303 while (--depth >= 0) {
1304 ix = path[depth].p_idx;
1305 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1306 EXT4_ERROR_INODE(inode,
1307 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1308 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1309 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1310 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1318 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1319 EXT4_ERROR_INODE(inode,
1320 "logical %d < ee_block %d + ee_len %d!",
1321 *logical, le32_to_cpu(ex->ee_block), ee_len);
1325 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1326 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1331 * search the closest allocated block to the right for *logical
1332 * and returns it at @logical + it's physical address at @phys
1333 * if *logical is the largest allocated block, the function
1334 * returns 0 at @phys
1335 * return value contains 0 (success) or error code
1337 static int ext4_ext_search_right(struct inode *inode,
1338 struct ext4_ext_path *path,
1339 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1340 struct ext4_extent **ret_ex)
1342 struct buffer_head *bh = NULL;
1343 struct ext4_extent_header *eh;
1344 struct ext4_extent_idx *ix;
1345 struct ext4_extent *ex;
1347 int depth; /* Note, NOT eh_depth; depth from top of tree */
1350 if (unlikely(path == NULL)) {
1351 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1354 depth = path->p_depth;
1357 if (depth == 0 && path->p_ext == NULL)
1360 /* usually extent in the path covers blocks smaller
1361 * then *logical, but it can be that extent is the
1362 * first one in the file */
1364 ex = path[depth].p_ext;
1365 ee_len = ext4_ext_get_actual_len(ex);
1366 if (*logical < le32_to_cpu(ex->ee_block)) {
1367 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1368 EXT4_ERROR_INODE(inode,
1369 "first_extent(path[%d].p_hdr) != ex",
1373 while (--depth >= 0) {
1374 ix = path[depth].p_idx;
1375 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1376 EXT4_ERROR_INODE(inode,
1377 "ix != EXT_FIRST_INDEX *logical %d!",
1385 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1386 EXT4_ERROR_INODE(inode,
1387 "logical %d < ee_block %d + ee_len %d!",
1388 *logical, le32_to_cpu(ex->ee_block), ee_len);
1392 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1393 /* next allocated block in this leaf */
1398 /* go up and search for index to the right */
1399 while (--depth >= 0) {
1400 ix = path[depth].p_idx;
1401 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1405 /* we've gone up to the root and found no index to the right */
1409 /* we've found index to the right, let's
1410 * follow it and find the closest allocated
1411 * block to the right */
1413 block = ext4_idx_pblock(ix);
1414 while (++depth < path->p_depth) {
1415 bh = sb_bread(inode->i_sb, block);
1418 eh = ext_block_hdr(bh);
1419 /* subtract from p_depth to get proper eh_depth */
1420 if (ext4_ext_check_block(inode, eh,
1421 path->p_depth - depth, bh)) {
1425 ix = EXT_FIRST_INDEX(eh);
1426 block = ext4_idx_pblock(ix);
1430 bh = sb_bread(inode->i_sb, block);
1433 eh = ext_block_hdr(bh);
1434 if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
1438 ex = EXT_FIRST_EXTENT(eh);
1440 *logical = le32_to_cpu(ex->ee_block);
1441 *phys = ext4_ext_pblock(ex);
1449 * ext4_ext_next_allocated_block:
1450 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1451 * NOTE: it considers block number from index entry as
1452 * allocated block. Thus, index entries have to be consistent
1456 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1460 BUG_ON(path == NULL);
1461 depth = path->p_depth;
1463 if (depth == 0 && path->p_ext == NULL)
1464 return EXT_MAX_BLOCKS;
1466 while (depth >= 0) {
1467 if (depth == path->p_depth) {
1469 if (path[depth].p_ext &&
1470 path[depth].p_ext !=
1471 EXT_LAST_EXTENT(path[depth].p_hdr))
1472 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1475 if (path[depth].p_idx !=
1476 EXT_LAST_INDEX(path[depth].p_hdr))
1477 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1482 return EXT_MAX_BLOCKS;
1486 * ext4_ext_next_leaf_block:
1487 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1489 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1493 BUG_ON(path == NULL);
1494 depth = path->p_depth;
1496 /* zero-tree has no leaf blocks at all */
1498 return EXT_MAX_BLOCKS;
1500 /* go to index block */
1503 while (depth >= 0) {
1504 if (path[depth].p_idx !=
1505 EXT_LAST_INDEX(path[depth].p_hdr))
1506 return (ext4_lblk_t)
1507 le32_to_cpu(path[depth].p_idx[1].ei_block);
1511 return EXT_MAX_BLOCKS;
1515 * ext4_ext_correct_indexes:
1516 * if leaf gets modified and modified extent is first in the leaf,
1517 * then we have to correct all indexes above.
1518 * TODO: do we need to correct tree in all cases?
1520 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1521 struct ext4_ext_path *path)
1523 struct ext4_extent_header *eh;
1524 int depth = ext_depth(inode);
1525 struct ext4_extent *ex;
1529 eh = path[depth].p_hdr;
1530 ex = path[depth].p_ext;
1532 if (unlikely(ex == NULL || eh == NULL)) {
1533 EXT4_ERROR_INODE(inode,
1534 "ex %p == NULL or eh %p == NULL", ex, eh);
1539 /* there is no tree at all */
1543 if (ex != EXT_FIRST_EXTENT(eh)) {
1544 /* we correct tree if first leaf got modified only */
1549 * TODO: we need correction if border is smaller than current one
1552 border = path[depth].p_ext->ee_block;
1553 err = ext4_ext_get_access(handle, inode, path + k);
1556 path[k].p_idx->ei_block = border;
1557 err = ext4_ext_dirty(handle, inode, path + k);
1562 /* change all left-side indexes */
1563 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1565 err = ext4_ext_get_access(handle, inode, path + k);
1568 path[k].p_idx->ei_block = border;
1569 err = ext4_ext_dirty(handle, inode, path + k);
1578 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1579 struct ext4_extent *ex2)
1581 unsigned short ext1_ee_len, ext2_ee_len, max_len;
1584 * Make sure that either both extents are uninitialized, or
1587 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1590 if (ext4_ext_is_uninitialized(ex1))
1591 max_len = EXT_UNINIT_MAX_LEN;
1593 max_len = EXT_INIT_MAX_LEN;
1595 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1596 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1598 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1599 le32_to_cpu(ex2->ee_block))
1603 * To allow future support for preallocated extents to be added
1604 * as an RO_COMPAT feature, refuse to merge to extents if
1605 * this can result in the top bit of ee_len being set.
1607 if (ext1_ee_len + ext2_ee_len > max_len)
1609 #ifdef AGGRESSIVE_TEST
1610 if (ext1_ee_len >= 4)
1614 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1620 * This function tries to merge the "ex" extent to the next extent in the tree.
1621 * It always tries to merge towards right. If you want to merge towards
1622 * left, pass "ex - 1" as argument instead of "ex".
1623 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1624 * 1 if they got merged.
1626 static int ext4_ext_try_to_merge_right(struct inode *inode,
1627 struct ext4_ext_path *path,
1628 struct ext4_extent *ex)
1630 struct ext4_extent_header *eh;
1631 unsigned int depth, len;
1633 int uninitialized = 0;
1635 depth = ext_depth(inode);
1636 BUG_ON(path[depth].p_hdr == NULL);
1637 eh = path[depth].p_hdr;
1639 while (ex < EXT_LAST_EXTENT(eh)) {
1640 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1642 /* merge with next extent! */
1643 if (ext4_ext_is_uninitialized(ex))
1645 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1646 + ext4_ext_get_actual_len(ex + 1));
1648 ext4_ext_mark_uninitialized(ex);
1650 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1651 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1652 * sizeof(struct ext4_extent);
1653 memmove(ex + 1, ex + 2, len);
1655 le16_add_cpu(&eh->eh_entries, -1);
1657 WARN_ON(eh->eh_entries == 0);
1658 if (!eh->eh_entries)
1659 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1666 * This function does a very simple check to see if we can collapse
1667 * an extent tree with a single extent tree leaf block into the inode.
1669 static void ext4_ext_try_to_merge_up(handle_t *handle,
1670 struct inode *inode,
1671 struct ext4_ext_path *path)
1674 unsigned max_root = ext4_ext_space_root(inode, 0);
1677 if ((path[0].p_depth != 1) ||
1678 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1679 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1683 * We need to modify the block allocation bitmap and the block
1684 * group descriptor to release the extent tree block. If we
1685 * can't get the journal credits, give up.
1687 if (ext4_journal_extend(handle, 2))
1691 * Copy the extent data up to the inode
1693 blk = ext4_idx_pblock(path[0].p_idx);
1694 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1695 sizeof(struct ext4_extent_idx);
1696 s += sizeof(struct ext4_extent_header);
1698 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1699 path[0].p_depth = 0;
1700 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1701 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1702 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1704 brelse(path[1].p_bh);
1705 ext4_free_blocks(handle, inode, NULL, blk, 1,
1706 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1710 * This function tries to merge the @ex extent to neighbours in the tree.
1711 * return 1 if merge left else 0.
1713 static void ext4_ext_try_to_merge(handle_t *handle,
1714 struct inode *inode,
1715 struct ext4_ext_path *path,
1716 struct ext4_extent *ex) {
1717 struct ext4_extent_header *eh;
1721 depth = ext_depth(inode);
1722 BUG_ON(path[depth].p_hdr == NULL);
1723 eh = path[depth].p_hdr;
1725 if (ex > EXT_FIRST_EXTENT(eh))
1726 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1729 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1731 ext4_ext_try_to_merge_up(handle, inode, path);
1735 * check if a portion of the "newext" extent overlaps with an
1738 * If there is an overlap discovered, it updates the length of the newext
1739 * such that there will be no overlap, and then returns 1.
1740 * If there is no overlap found, it returns 0.
1742 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1743 struct inode *inode,
1744 struct ext4_extent *newext,
1745 struct ext4_ext_path *path)
1748 unsigned int depth, len1;
1749 unsigned int ret = 0;
1751 b1 = le32_to_cpu(newext->ee_block);
1752 len1 = ext4_ext_get_actual_len(newext);
1753 depth = ext_depth(inode);
1754 if (!path[depth].p_ext)
1756 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1757 b2 &= ~(sbi->s_cluster_ratio - 1);
1760 * get the next allocated block if the extent in the path
1761 * is before the requested block(s)
1764 b2 = ext4_ext_next_allocated_block(path);
1765 if (b2 == EXT_MAX_BLOCKS)
1767 b2 &= ~(sbi->s_cluster_ratio - 1);
1770 /* check for wrap through zero on extent logical start block*/
1771 if (b1 + len1 < b1) {
1772 len1 = EXT_MAX_BLOCKS - b1;
1773 newext->ee_len = cpu_to_le16(len1);
1777 /* check for overlap */
1778 if (b1 + len1 > b2) {
1779 newext->ee_len = cpu_to_le16(b2 - b1);
1787 * ext4_ext_insert_extent:
1788 * tries to merge requsted extent into the existing extent or
1789 * inserts requested extent as new one into the tree,
1790 * creating new leaf in the no-space case.
1792 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1793 struct ext4_ext_path *path,
1794 struct ext4_extent *newext, int flag)
1796 struct ext4_extent_header *eh;
1797 struct ext4_extent *ex, *fex;
1798 struct ext4_extent *nearex; /* nearest extent */
1799 struct ext4_ext_path *npath = NULL;
1800 int depth, len, err;
1802 unsigned uninitialized = 0;
1805 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1806 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1809 depth = ext_depth(inode);
1810 ex = path[depth].p_ext;
1811 if (unlikely(path[depth].p_hdr == NULL)) {
1812 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1816 /* try to insert block into found extent and return */
1817 if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
1818 && ext4_can_extents_be_merged(inode, ex, newext)) {
1819 ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n",
1820 ext4_ext_is_uninitialized(newext),
1821 ext4_ext_get_actual_len(newext),
1822 le32_to_cpu(ex->ee_block),
1823 ext4_ext_is_uninitialized(ex),
1824 ext4_ext_get_actual_len(ex),
1825 ext4_ext_pblock(ex));
1826 err = ext4_ext_get_access(handle, inode, path + depth);
1831 * ext4_can_extents_be_merged should have checked that either
1832 * both extents are uninitialized, or both aren't. Thus we
1833 * need to check only one of them here.
1835 if (ext4_ext_is_uninitialized(ex))
1837 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1838 + ext4_ext_get_actual_len(newext));
1840 ext4_ext_mark_uninitialized(ex);
1841 eh = path[depth].p_hdr;
1846 depth = ext_depth(inode);
1847 eh = path[depth].p_hdr;
1848 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1851 /* probably next leaf has space for us? */
1852 fex = EXT_LAST_EXTENT(eh);
1853 next = EXT_MAX_BLOCKS;
1854 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
1855 next = ext4_ext_next_leaf_block(path);
1856 if (next != EXT_MAX_BLOCKS) {
1857 ext_debug("next leaf block - %u\n", next);
1858 BUG_ON(npath != NULL);
1859 npath = ext4_ext_find_extent(inode, next, NULL);
1861 return PTR_ERR(npath);
1862 BUG_ON(npath->p_depth != path->p_depth);
1863 eh = npath[depth].p_hdr;
1864 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1865 ext_debug("next leaf isn't full(%d)\n",
1866 le16_to_cpu(eh->eh_entries));
1870 ext_debug("next leaf has no free space(%d,%d)\n",
1871 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1875 * There is no free space in the found leaf.
1876 * We're gonna add a new leaf in the tree.
1878 if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
1879 flags = EXT4_MB_USE_ROOT_BLOCKS;
1880 err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
1883 depth = ext_depth(inode);
1884 eh = path[depth].p_hdr;
1887 nearex = path[depth].p_ext;
1889 err = ext4_ext_get_access(handle, inode, path + depth);
1894 /* there is no extent in this leaf, create first one */
1895 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
1896 le32_to_cpu(newext->ee_block),
1897 ext4_ext_pblock(newext),
1898 ext4_ext_is_uninitialized(newext),
1899 ext4_ext_get_actual_len(newext));
1900 nearex = EXT_FIRST_EXTENT(eh);
1902 if (le32_to_cpu(newext->ee_block)
1903 > le32_to_cpu(nearex->ee_block)) {
1905 ext_debug("insert %u:%llu:[%d]%d before: "
1907 le32_to_cpu(newext->ee_block),
1908 ext4_ext_pblock(newext),
1909 ext4_ext_is_uninitialized(newext),
1910 ext4_ext_get_actual_len(newext),
1915 BUG_ON(newext->ee_block == nearex->ee_block);
1916 ext_debug("insert %u:%llu:[%d]%d after: "
1918 le32_to_cpu(newext->ee_block),
1919 ext4_ext_pblock(newext),
1920 ext4_ext_is_uninitialized(newext),
1921 ext4_ext_get_actual_len(newext),
1924 len = EXT_LAST_EXTENT(eh) - nearex + 1;
1926 ext_debug("insert %u:%llu:[%d]%d: "
1927 "move %d extents from 0x%p to 0x%p\n",
1928 le32_to_cpu(newext->ee_block),
1929 ext4_ext_pblock(newext),
1930 ext4_ext_is_uninitialized(newext),
1931 ext4_ext_get_actual_len(newext),
1932 len, nearex, nearex + 1);
1933 memmove(nearex + 1, nearex,
1934 len * sizeof(struct ext4_extent));
1938 le16_add_cpu(&eh->eh_entries, 1);
1939 path[depth].p_ext = nearex;
1940 nearex->ee_block = newext->ee_block;
1941 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
1942 nearex->ee_len = newext->ee_len;
1945 /* try to merge extents */
1946 if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
1947 ext4_ext_try_to_merge(handle, inode, path, nearex);
1950 /* time to correct all indexes above */
1951 err = ext4_ext_correct_indexes(handle, inode, path);
1955 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
1959 ext4_ext_drop_refs(npath);
1962 ext4_ext_invalidate_cache(inode);
1966 static int ext4_fill_fiemap_extents(struct inode *inode,
1967 ext4_lblk_t block, ext4_lblk_t num,
1968 struct fiemap_extent_info *fieinfo)
1970 struct ext4_ext_path *path = NULL;
1971 struct ext4_ext_cache newex;
1972 struct ext4_extent *ex;
1973 ext4_lblk_t next, next_del, start = 0, end = 0;
1974 ext4_lblk_t last = block + num;
1975 int exists, depth = 0, err = 0;
1976 unsigned int flags = 0;
1977 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
1979 while (block < last && block != EXT_MAX_BLOCKS) {
1981 /* find extent for this block */
1982 down_read(&EXT4_I(inode)->i_data_sem);
1984 if (path && ext_depth(inode) != depth) {
1985 /* depth was changed. we have to realloc path */
1990 path = ext4_ext_find_extent(inode, block, path);
1992 up_read(&EXT4_I(inode)->i_data_sem);
1993 err = PTR_ERR(path);
1998 depth = ext_depth(inode);
1999 if (unlikely(path[depth].p_hdr == NULL)) {
2000 up_read(&EXT4_I(inode)->i_data_sem);
2001 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2005 ex = path[depth].p_ext;
2006 next = ext4_ext_next_allocated_block(path);
2007 ext4_ext_drop_refs(path);
2012 /* there is no extent yet, so try to allocate
2013 * all requested space */
2016 } else if (le32_to_cpu(ex->ee_block) > block) {
2017 /* need to allocate space before found extent */
2019 end = le32_to_cpu(ex->ee_block);
2020 if (block + num < end)
2022 } else if (block >= le32_to_cpu(ex->ee_block)
2023 + ext4_ext_get_actual_len(ex)) {
2024 /* need to allocate space after found extent */
2029 } else if (block >= le32_to_cpu(ex->ee_block)) {
2031 * some part of requested space is covered
2035 end = le32_to_cpu(ex->ee_block)
2036 + ext4_ext_get_actual_len(ex);
2037 if (block + num < end)
2043 BUG_ON(end <= start);
2046 newex.ec_block = start;
2047 newex.ec_len = end - start;
2050 newex.ec_block = le32_to_cpu(ex->ee_block);
2051 newex.ec_len = ext4_ext_get_actual_len(ex);
2052 newex.ec_start = ext4_ext_pblock(ex);
2053 if (ext4_ext_is_uninitialized(ex))
2054 flags |= FIEMAP_EXTENT_UNWRITTEN;
2058 * Find delayed extent and update newex accordingly. We call
2059 * it even in !exists case to find out whether newex is the
2060 * last existing extent or not.
2062 next_del = ext4_find_delayed_extent(inode, &newex);
2063 if (!exists && next_del) {
2065 flags |= FIEMAP_EXTENT_DELALLOC;
2067 up_read(&EXT4_I(inode)->i_data_sem);
2069 if (unlikely(newex.ec_len == 0)) {
2070 EXT4_ERROR_INODE(inode, "newex.ec_len == 0");
2075 /* This is possible iff next == next_del == EXT_MAX_BLOCKS */
2076 if (next == next_del) {
2077 flags |= FIEMAP_EXTENT_LAST;
2078 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2079 next != EXT_MAX_BLOCKS)) {
2080 EXT4_ERROR_INODE(inode,
2081 "next extent == %u, next "
2082 "delalloc extent = %u",
2090 err = fiemap_fill_next_extent(fieinfo,
2091 (__u64)newex.ec_block << blksize_bits,
2092 (__u64)newex.ec_start << blksize_bits,
2093 (__u64)newex.ec_len << blksize_bits,
2103 block = newex.ec_block + newex.ec_len;
2107 ext4_ext_drop_refs(path);
2115 ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
2116 __u32 len, ext4_fsblk_t start)
2118 struct ext4_ext_cache *cex;
2120 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
2121 trace_ext4_ext_put_in_cache(inode, block, len, start);
2122 cex = &EXT4_I(inode)->i_cached_extent;
2123 cex->ec_block = block;
2125 cex->ec_start = start;
2126 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
2130 * ext4_ext_put_gap_in_cache:
2131 * calculate boundaries of the gap that the requested block fits into
2132 * and cache this gap
2135 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2138 int depth = ext_depth(inode);
2141 struct ext4_extent *ex;
2143 ex = path[depth].p_ext;
2145 /* there is no extent yet, so gap is [0;-] */
2147 len = EXT_MAX_BLOCKS;
2148 ext_debug("cache gap(whole file):");
2149 } else if (block < le32_to_cpu(ex->ee_block)) {
2151 len = le32_to_cpu(ex->ee_block) - block;
2152 ext_debug("cache gap(before): %u [%u:%u]",
2154 le32_to_cpu(ex->ee_block),
2155 ext4_ext_get_actual_len(ex));
2156 } else if (block >= le32_to_cpu(ex->ee_block)
2157 + ext4_ext_get_actual_len(ex)) {
2159 lblock = le32_to_cpu(ex->ee_block)
2160 + ext4_ext_get_actual_len(ex);
2162 next = ext4_ext_next_allocated_block(path);
2163 ext_debug("cache gap(after): [%u:%u] %u",
2164 le32_to_cpu(ex->ee_block),
2165 ext4_ext_get_actual_len(ex),
2167 BUG_ON(next == lblock);
2168 len = next - lblock;
2174 ext_debug(" -> %u:%lu\n", lblock, len);
2175 ext4_ext_put_in_cache(inode, lblock, len, 0);
2179 * ext4_ext_in_cache()
2180 * Checks to see if the given block is in the cache.
2181 * If it is, the cached extent is stored in the given
2182 * cache extent pointer.
2184 * @inode: The files inode
2185 * @block: The block to look for in the cache
2186 * @ex: Pointer where the cached extent will be stored
2187 * if it contains block
2189 * Return 0 if cache is invalid; 1 if the cache is valid
2192 ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
2193 struct ext4_extent *ex)
2195 struct ext4_ext_cache *cex;
2196 struct ext4_sb_info *sbi;
2200 * We borrow i_block_reservation_lock to protect i_cached_extent
2202 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
2203 cex = &EXT4_I(inode)->i_cached_extent;
2204 sbi = EXT4_SB(inode->i_sb);
2206 /* has cache valid data? */
2207 if (cex->ec_len == 0)
2210 if (in_range(block, cex->ec_block, cex->ec_len)) {
2211 ex->ee_block = cpu_to_le32(cex->ec_block);
2212 ext4_ext_store_pblock(ex, cex->ec_start);
2213 ex->ee_len = cpu_to_le16(cex->ec_len);
2214 ext_debug("%u cached by %u:%u:%llu\n",
2216 cex->ec_block, cex->ec_len, cex->ec_start);
2220 trace_ext4_ext_in_cache(inode, block, ret);
2221 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
2227 * removes index from the index block.
2229 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2230 struct ext4_ext_path *path)
2235 /* free index block */
2237 leaf = ext4_idx_pblock(path->p_idx);
2238 if (unlikely(path->p_hdr->eh_entries == 0)) {
2239 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2242 err = ext4_ext_get_access(handle, inode, path);
2246 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2247 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2248 len *= sizeof(struct ext4_extent_idx);
2249 memmove(path->p_idx, path->p_idx + 1, len);
2252 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2253 err = ext4_ext_dirty(handle, inode, path);
2256 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2257 trace_ext4_ext_rm_idx(inode, leaf);
2259 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2260 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2265 * ext4_ext_calc_credits_for_single_extent:
2266 * This routine returns max. credits that needed to insert an extent
2267 * to the extent tree.
2268 * When pass the actual path, the caller should calculate credits
2271 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2272 struct ext4_ext_path *path)
2275 int depth = ext_depth(inode);
2278 /* probably there is space in leaf? */
2279 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2280 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2283 * There are some space in the leaf tree, no
2284 * need to account for leaf block credit
2286 * bitmaps and block group descriptor blocks
2287 * and other metadata blocks still need to be
2290 /* 1 bitmap, 1 block group descriptor */
2291 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2296 return ext4_chunk_trans_blocks(inode, nrblocks);
2300 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2302 * if nrblocks are fit in a single extent (chunk flag is 1), then
2303 * in the worse case, each tree level index/leaf need to be changed
2304 * if the tree split due to insert a new extent, then the old tree
2305 * index/leaf need to be updated too
2307 * If the nrblocks are discontiguous, they could cause
2308 * the whole tree split more than once, but this is really rare.
2310 int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
2313 int depth = ext_depth(inode);
2323 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2324 struct ext4_extent *ex,
2325 ext4_fsblk_t *partial_cluster,
2326 ext4_lblk_t from, ext4_lblk_t to)
2328 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2329 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2333 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2334 flags |= EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2335 else if (ext4_should_journal_data(inode))
2336 flags |= EXT4_FREE_BLOCKS_FORGET;
2339 * For bigalloc file systems, we never free a partial cluster
2340 * at the beginning of the extent. Instead, we make a note
2341 * that we tried freeing the cluster, and check to see if we
2342 * need to free it on a subsequent call to ext4_remove_blocks,
2343 * or at the end of the ext4_truncate() operation.
2345 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2347 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2349 * If we have a partial cluster, and it's different from the
2350 * cluster of the last block, we need to explicitly free the
2351 * partial cluster here.
2353 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2354 if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
2355 ext4_free_blocks(handle, inode, NULL,
2356 EXT4_C2B(sbi, *partial_cluster),
2357 sbi->s_cluster_ratio, flags);
2358 *partial_cluster = 0;
2361 #ifdef EXTENTS_STATS
2363 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2364 spin_lock(&sbi->s_ext_stats_lock);
2365 sbi->s_ext_blocks += ee_len;
2366 sbi->s_ext_extents++;
2367 if (ee_len < sbi->s_ext_min)
2368 sbi->s_ext_min = ee_len;
2369 if (ee_len > sbi->s_ext_max)
2370 sbi->s_ext_max = ee_len;
2371 if (ext_depth(inode) > sbi->s_depth_max)
2372 sbi->s_depth_max = ext_depth(inode);
2373 spin_unlock(&sbi->s_ext_stats_lock);
2376 if (from >= le32_to_cpu(ex->ee_block)
2377 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2381 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2382 pblk = ext4_ext_pblock(ex) + ee_len - num;
2383 ext_debug("free last %u blocks starting %llu\n", num, pblk);
2384 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2386 * If the block range to be freed didn't start at the
2387 * beginning of a cluster, and we removed the entire
2388 * extent, save the partial cluster here, since we
2389 * might need to delete if we determine that the
2390 * truncate operation has removed all of the blocks in
2393 if (pblk & (sbi->s_cluster_ratio - 1) &&
2395 *partial_cluster = EXT4_B2C(sbi, pblk);
2397 *partial_cluster = 0;
2398 } else if (from == le32_to_cpu(ex->ee_block)
2399 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
2405 start = ext4_ext_pblock(ex);
2407 ext_debug("free first %u blocks starting %llu\n", num, start);
2408 ext4_free_blocks(handle, inode, NULL, start, num, flags);
2411 printk(KERN_INFO "strange request: removal(2) "
2412 "%u-%u from %u:%u\n",
2413 from, to, le32_to_cpu(ex->ee_block), ee_len);
2420 * ext4_ext_rm_leaf() Removes the extents associated with the
2421 * blocks appearing between "start" and "end", and splits the extents
2422 * if "start" and "end" appear in the same extent
2424 * @handle: The journal handle
2425 * @inode: The files inode
2426 * @path: The path to the leaf
2427 * @start: The first block to remove
2428 * @end: The last block to remove
2431 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2432 struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster,
2433 ext4_lblk_t start, ext4_lblk_t end)
2435 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2436 int err = 0, correct_index = 0;
2437 int depth = ext_depth(inode), credits;
2438 struct ext4_extent_header *eh;
2441 ext4_lblk_t ex_ee_block;
2442 unsigned short ex_ee_len;
2443 unsigned uninitialized = 0;
2444 struct ext4_extent *ex;
2446 /* the header must be checked already in ext4_ext_remove_space() */
2447 ext_debug("truncate since %u in leaf to %u\n", start, end);
2448 if (!path[depth].p_hdr)
2449 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2450 eh = path[depth].p_hdr;
2451 if (unlikely(path[depth].p_hdr == NULL)) {
2452 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2455 /* find where to start removing */
2456 ex = EXT_LAST_EXTENT(eh);
2458 ex_ee_block = le32_to_cpu(ex->ee_block);
2459 ex_ee_len = ext4_ext_get_actual_len(ex);
2461 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2463 while (ex >= EXT_FIRST_EXTENT(eh) &&
2464 ex_ee_block + ex_ee_len > start) {
2466 if (ext4_ext_is_uninitialized(ex))
2471 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2472 uninitialized, ex_ee_len);
2473 path[depth].p_ext = ex;
2475 a = ex_ee_block > start ? ex_ee_block : start;
2476 b = ex_ee_block+ex_ee_len - 1 < end ?
2477 ex_ee_block+ex_ee_len - 1 : end;
2479 ext_debug(" border %u:%u\n", a, b);
2481 /* If this extent is beyond the end of the hole, skip it */
2482 if (end < ex_ee_block) {
2484 ex_ee_block = le32_to_cpu(ex->ee_block);
2485 ex_ee_len = ext4_ext_get_actual_len(ex);
2487 } else if (b != ex_ee_block + ex_ee_len - 1) {
2488 EXT4_ERROR_INODE(inode,
2489 "can not handle truncate %u:%u "
2491 start, end, ex_ee_block,
2492 ex_ee_block + ex_ee_len - 1);
2495 } else if (a != ex_ee_block) {
2496 /* remove tail of the extent */
2497 num = a - ex_ee_block;
2499 /* remove whole extent: excellent! */
2503 * 3 for leaf, sb, and inode plus 2 (bmap and group
2504 * descriptor) for each block group; assume two block
2505 * groups plus ex_ee_len/blocks_per_block_group for
2508 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2509 if (ex == EXT_FIRST_EXTENT(eh)) {
2511 credits += (ext_depth(inode)) + 1;
2513 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2515 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2519 err = ext4_ext_get_access(handle, inode, path + depth);
2523 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2529 /* this extent is removed; mark slot entirely unused */
2530 ext4_ext_store_pblock(ex, 0);
2532 ex->ee_len = cpu_to_le16(num);
2534 * Do not mark uninitialized if all the blocks in the
2535 * extent have been removed.
2537 if (uninitialized && num)
2538 ext4_ext_mark_uninitialized(ex);
2540 * If the extent was completely released,
2541 * we need to remove it from the leaf
2544 if (end != EXT_MAX_BLOCKS - 1) {
2546 * For hole punching, we need to scoot all the
2547 * extents up when an extent is removed so that
2548 * we dont have blank extents in the middle
2550 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2551 sizeof(struct ext4_extent));
2553 /* Now get rid of the one at the end */
2554 memset(EXT_LAST_EXTENT(eh), 0,
2555 sizeof(struct ext4_extent));
2557 le16_add_cpu(&eh->eh_entries, -1);
2559 *partial_cluster = 0;
2561 err = ext4_ext_dirty(handle, inode, path + depth);
2565 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2566 ext4_ext_pblock(ex));
2568 ex_ee_block = le32_to_cpu(ex->ee_block);
2569 ex_ee_len = ext4_ext_get_actual_len(ex);
2572 if (correct_index && eh->eh_entries)
2573 err = ext4_ext_correct_indexes(handle, inode, path);
2576 * If there is still a entry in the leaf node, check to see if
2577 * it references the partial cluster. This is the only place
2578 * where it could; if it doesn't, we can free the cluster.
2580 if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) &&
2581 (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
2582 *partial_cluster)) {
2583 int flags = EXT4_FREE_BLOCKS_FORGET;
2585 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2586 flags |= EXT4_FREE_BLOCKS_METADATA;
2588 ext4_free_blocks(handle, inode, NULL,
2589 EXT4_C2B(sbi, *partial_cluster),
2590 sbi->s_cluster_ratio, flags);
2591 *partial_cluster = 0;
2594 /* if this leaf is free, then we should
2595 * remove it from index block above */
2596 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2597 err = ext4_ext_rm_idx(handle, inode, path + depth);
2604 * ext4_ext_more_to_rm:
2605 * returns 1 if current index has to be freed (even partial)
2608 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2610 BUG_ON(path->p_idx == NULL);
2612 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2616 * if truncate on deeper level happened, it wasn't partial,
2617 * so we have to consider current index for truncation
2619 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2624 static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2627 struct super_block *sb = inode->i_sb;
2628 int depth = ext_depth(inode);
2629 struct ext4_ext_path *path = NULL;
2630 ext4_fsblk_t partial_cluster = 0;
2634 ext_debug("truncate since %u to %u\n", start, end);
2636 /* probably first extent we're gonna free will be last in block */
2637 handle = ext4_journal_start(inode, depth + 1);
2639 return PTR_ERR(handle);
2642 ext4_ext_invalidate_cache(inode);
2644 trace_ext4_ext_remove_space(inode, start, depth);
2647 * Check if we are removing extents inside the extent tree. If that
2648 * is the case, we are going to punch a hole inside the extent tree
2649 * so we have to check whether we need to split the extent covering
2650 * the last block to remove so we can easily remove the part of it
2651 * in ext4_ext_rm_leaf().
2653 if (end < EXT_MAX_BLOCKS - 1) {
2654 struct ext4_extent *ex;
2655 ext4_lblk_t ee_block;
2657 /* find extent for this block */
2658 path = ext4_ext_find_extent(inode, end, NULL);
2660 ext4_journal_stop(handle);
2661 return PTR_ERR(path);
2663 depth = ext_depth(inode);
2664 /* Leaf not may not exist only if inode has no blocks at all */
2665 ex = path[depth].p_ext;
2668 EXT4_ERROR_INODE(inode,
2669 "path[%d].p_hdr == NULL",
2676 ee_block = le32_to_cpu(ex->ee_block);
2679 * See if the last block is inside the extent, if so split
2680 * the extent at 'end' block so we can easily remove the
2681 * tail of the first part of the split extent in
2682 * ext4_ext_rm_leaf().
2684 if (end >= ee_block &&
2685 end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
2688 if (ext4_ext_is_uninitialized(ex))
2689 split_flag = EXT4_EXT_MARK_UNINIT1 |
2690 EXT4_EXT_MARK_UNINIT2;
2693 * Split the extent in two so that 'end' is the last
2694 * block in the first new extent
2696 err = ext4_split_extent_at(handle, inode, path,
2697 end + 1, split_flag,
2698 EXT4_GET_BLOCKS_PRE_IO |
2699 EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
2706 * We start scanning from right side, freeing all the blocks
2707 * after i_size and walking into the tree depth-wise.
2709 depth = ext_depth(inode);
2714 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2716 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2719 ext4_journal_stop(handle);
2722 path[0].p_depth = depth;
2723 path[0].p_hdr = ext_inode_hdr(inode);
2726 if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
2733 while (i >= 0 && err == 0) {
2735 /* this is leaf block */
2736 err = ext4_ext_rm_leaf(handle, inode, path,
2737 &partial_cluster, start,
2739 /* root level has p_bh == NULL, brelse() eats this */
2740 brelse(path[i].p_bh);
2741 path[i].p_bh = NULL;
2746 /* this is index block */
2747 if (!path[i].p_hdr) {
2748 ext_debug("initialize header\n");
2749 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2752 if (!path[i].p_idx) {
2753 /* this level hasn't been touched yet */
2754 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2755 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2756 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2758 le16_to_cpu(path[i].p_hdr->eh_entries));
2760 /* we were already here, see at next index */
2764 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2765 i, EXT_FIRST_INDEX(path[i].p_hdr),
2767 if (ext4_ext_more_to_rm(path + i)) {
2768 struct buffer_head *bh;
2769 /* go to the next level */
2770 ext_debug("move to level %d (block %llu)\n",
2771 i + 1, ext4_idx_pblock(path[i].p_idx));
2772 memset(path + i + 1, 0, sizeof(*path));
2773 bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
2775 /* should we reset i_size? */
2779 if (WARN_ON(i + 1 > depth)) {
2783 if (ext4_ext_check_block(inode, ext_block_hdr(bh),
2784 depth - i - 1, bh)) {
2788 path[i + 1].p_bh = bh;
2790 /* save actual number of indexes since this
2791 * number is changed at the next iteration */
2792 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2795 /* we finished processing this index, go up */
2796 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2797 /* index is empty, remove it;
2798 * handle must be already prepared by the
2799 * truncatei_leaf() */
2800 err = ext4_ext_rm_idx(handle, inode, path + i);
2802 /* root level has p_bh == NULL, brelse() eats this */
2803 brelse(path[i].p_bh);
2804 path[i].p_bh = NULL;
2806 ext_debug("return to level %d\n", i);
2810 trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster,
2811 path->p_hdr->eh_entries);
2813 /* If we still have something in the partial cluster and we have removed
2814 * even the first extent, then we should free the blocks in the partial
2815 * cluster as well. */
2816 if (partial_cluster && path->p_hdr->eh_entries == 0) {
2817 int flags = EXT4_FREE_BLOCKS_FORGET;
2819 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2820 flags |= EXT4_FREE_BLOCKS_METADATA;
2822 ext4_free_blocks(handle, inode, NULL,
2823 EXT4_C2B(EXT4_SB(sb), partial_cluster),
2824 EXT4_SB(sb)->s_cluster_ratio, flags);
2825 partial_cluster = 0;
2828 /* TODO: flexible tree reduction should be here */
2829 if (path->p_hdr->eh_entries == 0) {
2831 * truncate to zero freed all the tree,
2832 * so we need to correct eh_depth
2834 err = ext4_ext_get_access(handle, inode, path);
2836 ext_inode_hdr(inode)->eh_depth = 0;
2837 ext_inode_hdr(inode)->eh_max =
2838 cpu_to_le16(ext4_ext_space_root(inode, 0));
2839 err = ext4_ext_dirty(handle, inode, path);
2843 ext4_ext_drop_refs(path);
2845 if (err == -EAGAIN) {
2849 ext4_journal_stop(handle);
2855 * called at mount time
2857 void ext4_ext_init(struct super_block *sb)
2860 * possible initialization would be here
2863 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2864 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2865 printk(KERN_INFO "EXT4-fs: file extents enabled"
2866 #ifdef AGGRESSIVE_TEST
2867 ", aggressive tests"
2869 #ifdef CHECK_BINSEARCH
2872 #ifdef EXTENTS_STATS
2877 #ifdef EXTENTS_STATS
2878 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2879 EXT4_SB(sb)->s_ext_min = 1 << 30;
2880 EXT4_SB(sb)->s_ext_max = 0;
2886 * called at umount time
2888 void ext4_ext_release(struct super_block *sb)
2890 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
2893 #ifdef EXTENTS_STATS
2894 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2895 struct ext4_sb_info *sbi = EXT4_SB(sb);
2896 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2897 sbi->s_ext_blocks, sbi->s_ext_extents,
2898 sbi->s_ext_blocks / sbi->s_ext_extents);
2899 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2900 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2905 /* FIXME!! we need to try to merge to left or right after zero-out */
2906 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2908 ext4_fsblk_t ee_pblock;
2909 unsigned int ee_len;
2912 ee_len = ext4_ext_get_actual_len(ex);
2913 ee_pblock = ext4_ext_pblock(ex);
2915 ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
2923 * ext4_split_extent_at() splits an extent at given block.
2925 * @handle: the journal handle
2926 * @inode: the file inode
2927 * @path: the path to the extent
2928 * @split: the logical block where the extent is splitted.
2929 * @split_flags: indicates if the extent could be zeroout if split fails, and
2930 * the states(init or uninit) of new extents.
2931 * @flags: flags used to insert new extent to extent tree.
2934 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
2935 * of which are deterimined by split_flag.
2937 * There are two cases:
2938 * a> the extent are splitted into two extent.
2939 * b> split is not needed, and just mark the extent.
2941 * return 0 on success.
2943 static int ext4_split_extent_at(handle_t *handle,
2944 struct inode *inode,
2945 struct ext4_ext_path *path,
2950 ext4_fsblk_t newblock;
2951 ext4_lblk_t ee_block;
2952 struct ext4_extent *ex, newex, orig_ex;
2953 struct ext4_extent *ex2 = NULL;
2954 unsigned int ee_len, depth;
2957 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
2958 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
2960 ext_debug("ext4_split_extents_at: inode %lu, logical"
2961 "block %llu\n", inode->i_ino, (unsigned long long)split);
2963 ext4_ext_show_leaf(inode, path);
2965 depth = ext_depth(inode);
2966 ex = path[depth].p_ext;
2967 ee_block = le32_to_cpu(ex->ee_block);
2968 ee_len = ext4_ext_get_actual_len(ex);
2969 newblock = split - ee_block + ext4_ext_pblock(ex);
2971 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
2973 err = ext4_ext_get_access(handle, inode, path + depth);
2977 if (split == ee_block) {
2979 * case b: block @split is the block that the extent begins with
2980 * then we just change the state of the extent, and splitting
2983 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2984 ext4_ext_mark_uninitialized(ex);
2986 ext4_ext_mark_initialized(ex);
2988 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
2989 ext4_ext_try_to_merge(handle, inode, path, ex);
2991 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2996 memcpy(&orig_ex, ex, sizeof(orig_ex));
2997 ex->ee_len = cpu_to_le16(split - ee_block);
2998 if (split_flag & EXT4_EXT_MARK_UNINIT1)
2999 ext4_ext_mark_uninitialized(ex);
3002 * path may lead to new leaf, not to original leaf any more
3003 * after ext4_ext_insert_extent() returns,
3005 err = ext4_ext_dirty(handle, inode, path + depth);
3007 goto fix_extent_len;
3010 ex2->ee_block = cpu_to_le32(split);
3011 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3012 ext4_ext_store_pblock(ex2, newblock);
3013 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3014 ext4_ext_mark_uninitialized(ex2);
3016 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
3017 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3018 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3019 if (split_flag & EXT4_EXT_DATA_VALID1)
3020 err = ext4_ext_zeroout(inode, ex2);
3022 err = ext4_ext_zeroout(inode, ex);
3024 err = ext4_ext_zeroout(inode, &orig_ex);
3027 goto fix_extent_len;
3028 /* update the extent length and mark as initialized */
3029 ex->ee_len = cpu_to_le16(ee_len);
3030 ext4_ext_try_to_merge(handle, inode, path, ex);
3031 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3034 goto fix_extent_len;
3037 ext4_ext_show_leaf(inode, path);
3041 ex->ee_len = orig_ex.ee_len;
3042 ext4_ext_dirty(handle, inode, path + depth);
3047 * ext4_split_extents() splits an extent and mark extent which is covered
3048 * by @map as split_flags indicates
3050 * It may result in splitting the extent into multiple extents (upto three)
3051 * There are three possibilities:
3052 * a> There is no split required
3053 * b> Splits in two extents: Split is happening at either end of the extent
3054 * c> Splits in three extents: Somone is splitting in middle of the extent
3057 static int ext4_split_extent(handle_t *handle,
3058 struct inode *inode,
3059 struct ext4_ext_path *path,
3060 struct ext4_map_blocks *map,
3064 ext4_lblk_t ee_block;
3065 struct ext4_extent *ex;
3066 unsigned int ee_len, depth;
3069 int split_flag1, flags1;
3071 depth = ext_depth(inode);
3072 ex = path[depth].p_ext;
3073 ee_block = le32_to_cpu(ex->ee_block);
3074 ee_len = ext4_ext_get_actual_len(ex);
3075 uninitialized = ext4_ext_is_uninitialized(ex);
3077 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3078 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3079 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3081 split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
3082 EXT4_EXT_MARK_UNINIT2;
3083 if (split_flag & EXT4_EXT_DATA_VALID2)
3084 split_flag1 |= EXT4_EXT_DATA_VALID1;
3085 err = ext4_split_extent_at(handle, inode, path,
3086 map->m_lblk + map->m_len, split_flag1, flags1);
3091 ext4_ext_drop_refs(path);
3092 path = ext4_ext_find_extent(inode, map->m_lblk, path);
3094 return PTR_ERR(path);
3096 if (map->m_lblk >= ee_block) {
3097 split_flag1 = split_flag & (EXT4_EXT_MAY_ZEROOUT |
3098 EXT4_EXT_DATA_VALID2);
3100 split_flag1 |= EXT4_EXT_MARK_UNINIT1;
3101 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3102 split_flag1 |= EXT4_EXT_MARK_UNINIT2;
3103 err = ext4_split_extent_at(handle, inode, path,
3104 map->m_lblk, split_flag1, flags);
3109 ext4_ext_show_leaf(inode, path);
3111 return err ? err : map->m_len;
3115 * This function is called by ext4_ext_map_blocks() if someone tries to write
3116 * to an uninitialized extent. It may result in splitting the uninitialized
3117 * extent into multiple extents (up to three - one initialized and two
3119 * There are three possibilities:
3120 * a> There is no split required: Entire extent should be initialized
3121 * b> Splits in two extents: Write is happening at either end of the extent
3122 * c> Splits in three extents: Somone is writing in middle of the extent
3125 * - The extent pointed to by 'path' is uninitialized.
3126 * - The extent pointed to by 'path' contains a superset
3127 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3129 * Post-conditions on success:
3130 * - the returned value is the number of blocks beyond map->l_lblk
3131 * that are allocated and initialized.
3132 * It is guaranteed to be >= map->m_len.
3134 static int ext4_ext_convert_to_initialized(handle_t *handle,
3135 struct inode *inode,
3136 struct ext4_map_blocks *map,
3137 struct ext4_ext_path *path)
3139 struct ext4_sb_info *sbi;
3140 struct ext4_extent_header *eh;
3141 struct ext4_map_blocks split_map;
3142 struct ext4_extent zero_ex;
3143 struct ext4_extent *ex;
3144 ext4_lblk_t ee_block, eof_block;
3145 unsigned int ee_len, depth;
3146 int allocated, max_zeroout = 0;
3150 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3151 "block %llu, max_blocks %u\n", inode->i_ino,
3152 (unsigned long long)map->m_lblk, map->m_len);
3154 sbi = EXT4_SB(inode->i_sb);
3155 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3156 inode->i_sb->s_blocksize_bits;
3157 if (eof_block < map->m_lblk + map->m_len)
3158 eof_block = map->m_lblk + map->m_len;
3160 depth = ext_depth(inode);
3161 eh = path[depth].p_hdr;
3162 ex = path[depth].p_ext;
3163 ee_block = le32_to_cpu(ex->ee_block);
3164 ee_len = ext4_ext_get_actual_len(ex);
3165 allocated = ee_len - (map->m_lblk - ee_block);
3167 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3169 /* Pre-conditions */
3170 BUG_ON(!ext4_ext_is_uninitialized(ex));
3171 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3174 * Attempt to transfer newly initialized blocks from the currently
3175 * uninitialized extent to its left neighbor. This is much cheaper
3176 * than an insertion followed by a merge as those involve costly
3177 * memmove() calls. This is the common case in steady state for
3178 * workloads doing fallocate(FALLOC_FL_KEEP_SIZE) followed by append
3181 * Limitations of the current logic:
3182 * - L1: we only deal with writes at the start of the extent.
3183 * The approach could be extended to writes at the end
3184 * of the extent but this scenario was deemed less common.
3185 * - L2: we do not deal with writes covering the whole extent.
3186 * This would require removing the extent if the transfer
3188 * - L3: we only attempt to merge with an extent stored in the
3189 * same extent tree node.
3191 if ((map->m_lblk == ee_block) && /*L1*/
3192 (map->m_len < ee_len) && /*L2*/
3193 (ex > EXT_FIRST_EXTENT(eh))) { /*L3*/
3194 struct ext4_extent *prev_ex;
3195 ext4_lblk_t prev_lblk;
3196 ext4_fsblk_t prev_pblk, ee_pblk;
3197 unsigned int prev_len, write_len;
3200 prev_lblk = le32_to_cpu(prev_ex->ee_block);
3201 prev_len = ext4_ext_get_actual_len(prev_ex);
3202 prev_pblk = ext4_ext_pblock(prev_ex);
3203 ee_pblk = ext4_ext_pblock(ex);
3204 write_len = map->m_len;
3207 * A transfer of blocks from 'ex' to 'prev_ex' is allowed
3208 * upon those conditions:
3209 * - C1: prev_ex is initialized,
3210 * - C2: prev_ex is logically abutting ex,
3211 * - C3: prev_ex is physically abutting ex,
3212 * - C4: prev_ex can receive the additional blocks without
3213 * overflowing the (initialized) length limit.
3215 if ((!ext4_ext_is_uninitialized(prev_ex)) && /*C1*/
3216 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3217 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3218 (prev_len < (EXT_INIT_MAX_LEN - write_len))) { /*C4*/
3219 err = ext4_ext_get_access(handle, inode, path + depth);
3223 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3226 /* Shift the start of ex by 'write_len' blocks */
3227 ex->ee_block = cpu_to_le32(ee_block + write_len);
3228 ext4_ext_store_pblock(ex, ee_pblk + write_len);
3229 ex->ee_len = cpu_to_le16(ee_len - write_len);
3230 ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3232 /* Extend prev_ex by 'write_len' blocks */
3233 prev_ex->ee_len = cpu_to_le16(prev_len + write_len);
3235 /* Mark the block containing both extents as dirty */
3236 ext4_ext_dirty(handle, inode, path + depth);
3238 /* Update path to point to the right extent */
3239 path[depth].p_ext = prev_ex;
3241 /* Result: number of initialized blocks past m_lblk */
3242 allocated = write_len;
3247 WARN_ON(map->m_lblk < ee_block);
3249 * It is safe to convert extent to initialized via explicit
3250 * zeroout only if extent is fully insde i_size or new_size.
3252 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3254 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3255 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3256 inode->i_sb->s_blocksize_bits;
3258 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3259 if (max_zeroout && (ee_len <= max_zeroout)) {
3260 err = ext4_ext_zeroout(inode, ex);
3264 err = ext4_ext_get_access(handle, inode, path + depth);
3267 ext4_ext_mark_initialized(ex);
3268 ext4_ext_try_to_merge(handle, inode, path, ex);
3269 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3275 * 1. split the extent into three extents.
3276 * 2. split the extent into two extents, zeroout the first half.
3277 * 3. split the extent into two extents, zeroout the second half.
3278 * 4. split the extent into two extents with out zeroout.
3280 split_map.m_lblk = map->m_lblk;
3281 split_map.m_len = map->m_len;
3283 if (max_zeroout && (allocated > map->m_len)) {
3284 if (allocated <= max_zeroout) {
3287 cpu_to_le32(map->m_lblk);
3288 zero_ex.ee_len = cpu_to_le16(allocated);
3289 ext4_ext_store_pblock(&zero_ex,
3290 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3291 err = ext4_ext_zeroout(inode, &zero_ex);
3294 split_map.m_lblk = map->m_lblk;
3295 split_map.m_len = allocated;
3296 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3298 if (map->m_lblk != ee_block) {
3299 zero_ex.ee_block = ex->ee_block;
3300 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3302 ext4_ext_store_pblock(&zero_ex,
3303 ext4_ext_pblock(ex));
3304 err = ext4_ext_zeroout(inode, &zero_ex);
3309 split_map.m_lblk = ee_block;
3310 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3311 allocated = map->m_len;
3315 allocated = ext4_split_extent(handle, inode, path,
3316 &split_map, split_flag, 0);
3321 return err ? err : allocated;
3325 * This function is called by ext4_ext_map_blocks() from
3326 * ext4_get_blocks_dio_write() when DIO to write
3327 * to an uninitialized extent.
3329 * Writing to an uninitialized extent may result in splitting the uninitialized
3330 * extent into multiple initialized/uninitialized extents (up to three)
3331 * There are three possibilities:
3332 * a> There is no split required: Entire extent should be uninitialized
3333 * b> Splits in two extents: Write is happening at either end of the extent
3334 * c> Splits in three extents: Somone is writing in middle of the extent
3336 * One of more index blocks maybe needed if the extent tree grow after
3337 * the uninitialized extent split. To prevent ENOSPC occur at the IO
3338 * complete, we need to split the uninitialized extent before DIO submit
3339 * the IO. The uninitialized extent called at this time will be split
3340 * into three uninitialized extent(at most). After IO complete, the part
3341 * being filled will be convert to initialized by the end_io callback function
3342 * via ext4_convert_unwritten_extents().
3344 * Returns the size of uninitialized extent to be written on success.
3346 static int ext4_split_unwritten_extents(handle_t *handle,
3347 struct inode *inode,
3348 struct ext4_map_blocks *map,
3349 struct ext4_ext_path *path,
3352 ext4_lblk_t eof_block;
3353 ext4_lblk_t ee_block;
3354 struct ext4_extent *ex;
3355 unsigned int ee_len;
3356 int split_flag = 0, depth;
3358 ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3359 "block %llu, max_blocks %u\n", inode->i_ino,
3360 (unsigned long long)map->m_lblk, map->m_len);
3362 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3363 inode->i_sb->s_blocksize_bits;
3364 if (eof_block < map->m_lblk + map->m_len)
3365 eof_block = map->m_lblk + map->m_len;
3367 * It is safe to convert extent to initialized via explicit
3368 * zeroout only if extent is fully insde i_size or new_size.
3370 depth = ext_depth(inode);
3371 ex = path[depth].p_ext;
3372 ee_block = le32_to_cpu(ex->ee_block);
3373 ee_len = ext4_ext_get_actual_len(ex);
3375 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3376 split_flag |= EXT4_EXT_MARK_UNINIT2;
3377 if (flags & EXT4_GET_BLOCKS_CONVERT)
3378 split_flag |= EXT4_EXT_DATA_VALID2;
3379 flags |= EXT4_GET_BLOCKS_PRE_IO;
3380 return ext4_split_extent(handle, inode, path, map, split_flag, flags);
3383 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3384 struct inode *inode,
3385 struct ext4_map_blocks *map,
3386 struct ext4_ext_path *path)
3388 struct ext4_extent *ex;
3389 ext4_lblk_t ee_block;
3390 unsigned int ee_len;
3394 depth = ext_depth(inode);
3395 ex = path[depth].p_ext;
3396 ee_block = le32_to_cpu(ex->ee_block);
3397 ee_len = ext4_ext_get_actual_len(ex);
3399 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3400 "block %llu, max_blocks %u\n", inode->i_ino,
3401 (unsigned long long)ee_block, ee_len);
3403 /* If extent is larger than requested then split is required */
3404 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3405 err = ext4_split_unwritten_extents(handle, inode, map, path,
3406 EXT4_GET_BLOCKS_CONVERT);
3409 ext4_ext_drop_refs(path);
3410 path = ext4_ext_find_extent(inode, map->m_lblk, path);
3412 err = PTR_ERR(path);
3415 depth = ext_depth(inode);
3416 ex = path[depth].p_ext;
3419 err = ext4_ext_get_access(handle, inode, path + depth);
3422 /* first mark the extent as initialized */
3423 ext4_ext_mark_initialized(ex);
3425 /* note: ext4_ext_correct_indexes() isn't needed here because
3426 * borders are not changed
3428 ext4_ext_try_to_merge(handle, inode, path, ex);
3430 /* Mark modified extent as dirty */
3431 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3433 ext4_ext_show_leaf(inode, path);
3437 static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3438 sector_t block, int count)
3441 for (i = 0; i < count; i++)
3442 unmap_underlying_metadata(bdev, block + i);
3446 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3448 static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3450 struct ext4_ext_path *path,
3454 struct ext4_extent_header *eh;
3455 struct ext4_extent *last_ex;
3457 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3460 depth = ext_depth(inode);
3461 eh = path[depth].p_hdr;
3464 * We're going to remove EOFBLOCKS_FL entirely in future so we
3465 * do not care for this case anymore. Simply remove the flag
3466 * if there are no extents.
3468 if (unlikely(!eh->eh_entries))
3470 last_ex = EXT_LAST_EXTENT(eh);
3472 * We should clear the EOFBLOCKS_FL flag if we are writing the
3473 * last block in the last extent in the file. We test this by
3474 * first checking to see if the caller to
3475 * ext4_ext_get_blocks() was interested in the last block (or
3476 * a block beyond the last block) in the current extent. If
3477 * this turns out to be false, we can bail out from this
3478 * function immediately.
3480 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3481 ext4_ext_get_actual_len(last_ex))
3484 * If the caller does appear to be planning to write at or
3485 * beyond the end of the current extent, we then test to see
3486 * if the current extent is the last extent in the file, by
3487 * checking to make sure it was reached via the rightmost node
3488 * at each level of the tree.
3490 for (i = depth-1; i >= 0; i--)
3491 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3494 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3495 return ext4_mark_inode_dirty(handle, inode);
3499 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3501 * Return 1 if there is a delalloc block in the range, otherwise 0.
3503 static int ext4_find_delalloc_range(struct inode *inode,
3504 ext4_lblk_t lblk_start,
3505 ext4_lblk_t lblk_end)
3507 struct extent_status es;
3509 es.start = lblk_start;
3510 ext4_es_find_extent(inode, &es);
3512 return 0; /* there is no delay extent in this tree */
3513 else if (es.start <= lblk_start && lblk_start < es.start + es.len)
3515 else if (lblk_start <= es.start && es.start <= lblk_end)
3521 int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3523 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3524 ext4_lblk_t lblk_start, lblk_end;
3525 lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
3526 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3528 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3532 * Determines how many complete clusters (out of those specified by the 'map')
3533 * are under delalloc and were reserved quota for.
3534 * This function is called when we are writing out the blocks that were
3535 * originally written with their allocation delayed, but then the space was
3536 * allocated using fallocate() before the delayed allocation could be resolved.
3537 * The cases to look for are:
3538 * ('=' indicated delayed allocated blocks
3539 * '-' indicates non-delayed allocated blocks)
3540 * (a) partial clusters towards beginning and/or end outside of allocated range
3541 * are not delalloc'ed.
3543 * |----c---=|====c====|====c====|===-c----|
3544 * |++++++ allocated ++++++|
3545 * ==> 4 complete clusters in above example
3547 * (b) partial cluster (outside of allocated range) towards either end is
3548 * marked for delayed allocation. In this case, we will exclude that
3551 * |----====c========|========c========|
3552 * |++++++ allocated ++++++|
3553 * ==> 1 complete clusters in above example
3556 * |================c================|
3557 * |++++++ allocated ++++++|
3558 * ==> 0 complete clusters in above example
3560 * The ext4_da_update_reserve_space will be called only if we
3561 * determine here that there were some "entire" clusters that span
3562 * this 'allocated' range.
3563 * In the non-bigalloc case, this function will just end up returning num_blks
3564 * without ever calling ext4_find_delalloc_range.
3567 get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3568 unsigned int num_blks)
3570 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3571 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3572 ext4_lblk_t lblk_from, lblk_to, c_offset;
3573 unsigned int allocated_clusters = 0;
3575 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3576 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3578 /* max possible clusters for this allocation */
3579 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3581 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3583 /* Check towards left side */
3584 c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
3586 lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
3587 lblk_to = lblk_from + c_offset - 1;
3589 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3590 allocated_clusters--;
3593 /* Now check towards right. */
3594 c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
3595 if (allocated_clusters && c_offset) {
3596 lblk_from = lblk_start + num_blks;
3597 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3599 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3600 allocated_clusters--;
3603 return allocated_clusters;
3607 ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3608 struct ext4_map_blocks *map,
3609 struct ext4_ext_path *path, int flags,
3610 unsigned int allocated, ext4_fsblk_t newblock)
3614 ext4_io_end_t *io = ext4_inode_aio(inode);
3616 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
3617 "block %llu, max_blocks %u, flags %x, allocated %u\n",
3618 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
3620 ext4_ext_show_leaf(inode, path);
3622 trace_ext4_ext_handle_uninitialized_extents(inode, map, flags,
3623 allocated, newblock);
3625 /* get_block() before submit the IO, split the extent */
3626 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3627 ret = ext4_split_unwritten_extents(handle, inode, map,
3632 * Flag the inode(non aio case) or end_io struct (aio case)
3633 * that this IO needs to conversion to written when IO is
3637 ext4_set_io_unwritten_flag(inode, io);
3639 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3640 if (ext4_should_dioread_nolock(inode))
3641 map->m_flags |= EXT4_MAP_UNINIT;
3644 /* IO end_io complete, convert the filled extent to written */
3645 if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
3646 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
3649 ext4_update_inode_fsync_trans(handle, inode, 1);
3650 err = check_eofblocks_fl(handle, inode, map->m_lblk,
3656 /* buffered IO case */
3658 * repeat fallocate creation request
3659 * we already have an unwritten extent
3661 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
3664 /* buffered READ or buffered write_begin() lookup */
3665 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3667 * We have blocks reserved already. We
3668 * return allocated blocks so that delalloc
3669 * won't do block reservation for us. But
3670 * the buffer head will be unmapped so that
3671 * a read from the block returns 0s.
3673 map->m_flags |= EXT4_MAP_UNWRITTEN;
3677 /* buffered write, writepage time, convert*/
3678 ret = ext4_ext_convert_to_initialized(handle, inode, map, path);
3680 ext4_update_inode_fsync_trans(handle, inode, 1);
3687 map->m_flags |= EXT4_MAP_NEW;
3689 * if we allocated more blocks than requested
3690 * we need to make sure we unmap the extra block
3691 * allocated. The actual needed block will get
3692 * unmapped later when we find the buffer_head marked
3695 if (allocated > map->m_len) {
3696 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
3697 newblock + map->m_len,
3698 allocated - map->m_len);
3699 allocated = map->m_len;
3703 * If we have done fallocate with the offset that is already
3704 * delayed allocated, we would have block reservation
3705 * and quota reservation done in the delayed write path.
3706 * But fallocate would have already updated quota and block
3707 * count for this offset. So cancel these reservation
3709 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
3710 unsigned int reserved_clusters;
3711 reserved_clusters = get_reserved_cluster_alloc(inode,
3712 map->m_lblk, map->m_len);
3713 if (reserved_clusters)
3714 ext4_da_update_reserve_space(inode,
3720 map->m_flags |= EXT4_MAP_MAPPED;
3721 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
3722 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
3728 if (allocated > map->m_len)
3729 allocated = map->m_len;
3730 ext4_ext_show_leaf(inode, path);
3731 map->m_pblk = newblock;
3732 map->m_len = allocated;
3735 ext4_ext_drop_refs(path);
3738 return err ? err : allocated;
3742 * get_implied_cluster_alloc - check to see if the requested
3743 * allocation (in the map structure) overlaps with a cluster already
3744 * allocated in an extent.
3745 * @sb The filesystem superblock structure
3746 * @map The requested lblk->pblk mapping
3747 * @ex The extent structure which might contain an implied
3748 * cluster allocation
3750 * This function is called by ext4_ext_map_blocks() after we failed to
3751 * find blocks that were already in the inode's extent tree. Hence,
3752 * we know that the beginning of the requested region cannot overlap
3753 * the extent from the inode's extent tree. There are three cases we
3754 * want to catch. The first is this case:
3756 * |--- cluster # N--|
3757 * |--- extent ---| |---- requested region ---|
3760 * The second case that we need to test for is this one:
3762 * |--------- cluster # N ----------------|
3763 * |--- requested region --| |------- extent ----|
3764 * |=======================|
3766 * The third case is when the requested region lies between two extents
3767 * within the same cluster:
3768 * |------------- cluster # N-------------|
3769 * |----- ex -----| |---- ex_right ----|
3770 * |------ requested region ------|
3771 * |================|
3773 * In each of the above cases, we need to set the map->m_pblk and
3774 * map->m_len so it corresponds to the return the extent labelled as
3775 * "|====|" from cluster #N, since it is already in use for data in
3776 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
3777 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
3778 * as a new "allocated" block region. Otherwise, we will return 0 and
3779 * ext4_ext_map_blocks() will then allocate one or more new clusters
3780 * by calling ext4_mb_new_blocks().
3782 static int get_implied_cluster_alloc(struct super_block *sb,
3783 struct ext4_map_blocks *map,
3784 struct ext4_extent *ex,
3785 struct ext4_ext_path *path)
3787 struct ext4_sb_info *sbi = EXT4_SB(sb);
3788 ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3789 ext4_lblk_t ex_cluster_start, ex_cluster_end;
3790 ext4_lblk_t rr_cluster_start;
3791 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3792 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3793 unsigned short ee_len = ext4_ext_get_actual_len(ex);
3795 /* The extent passed in that we are trying to match */
3796 ex_cluster_start = EXT4_B2C(sbi, ee_block);
3797 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
3799 /* The requested region passed into ext4_map_blocks() */
3800 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
3802 if ((rr_cluster_start == ex_cluster_end) ||
3803 (rr_cluster_start == ex_cluster_start)) {
3804 if (rr_cluster_start == ex_cluster_end)
3805 ee_start += ee_len - 1;
3806 map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) +
3808 map->m_len = min(map->m_len,
3809 (unsigned) sbi->s_cluster_ratio - c_offset);
3811 * Check for and handle this case:
3813 * |--------- cluster # N-------------|
3814 * |------- extent ----|
3815 * |--- requested region ---|
3819 if (map->m_lblk < ee_block)
3820 map->m_len = min(map->m_len, ee_block - map->m_lblk);
3823 * Check for the case where there is already another allocated
3824 * block to the right of 'ex' but before the end of the cluster.
3826 * |------------- cluster # N-------------|
3827 * |----- ex -----| |---- ex_right ----|
3828 * |------ requested region ------|
3829 * |================|
3831 if (map->m_lblk > ee_block) {
3832 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
3833 map->m_len = min(map->m_len, next - map->m_lblk);
3836 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
3840 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
3846 * Block allocation/map/preallocation routine for extents based files
3849 * Need to be called with
3850 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
3851 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
3853 * return > 0, number of of blocks already mapped/allocated
3854 * if create == 0 and these are pre-allocated blocks
3855 * buffer head is unmapped
3856 * otherwise blocks are mapped
3858 * return = 0, if plain look up failed (blocks have not been allocated)
3859 * buffer head is unmapped
3861 * return < 0, error case.
3863 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3864 struct ext4_map_blocks *map, int flags)
3866 struct ext4_ext_path *path = NULL;
3867 struct ext4_extent newex, *ex, *ex2;
3868 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3869 ext4_fsblk_t newblock = 0;
3870 int free_on_err = 0, err = 0, depth;
3871 unsigned int allocated = 0, offset = 0;
3872 unsigned int allocated_clusters = 0;
3873 struct ext4_allocation_request ar;
3874 ext4_io_end_t *io = ext4_inode_aio(inode);
3875 ext4_lblk_t cluster_offset;
3876 int set_unwritten = 0;
3878 ext_debug("blocks %u/%u requested for inode %lu\n",
3879 map->m_lblk, map->m_len, inode->i_ino);
3880 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
3882 /* check in cache */
3883 if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
3884 if (!newex.ee_start_lo && !newex.ee_start_hi) {
3885 if ((sbi->s_cluster_ratio > 1) &&
3886 ext4_find_delalloc_cluster(inode, map->m_lblk))
3887 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3889 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3891 * block isn't allocated yet and
3892 * user doesn't want to allocate it
3896 /* we should allocate requested block */
3898 /* block is already allocated */
3899 if (sbi->s_cluster_ratio > 1)
3900 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3901 newblock = map->m_lblk
3902 - le32_to_cpu(newex.ee_block)
3903 + ext4_ext_pblock(&newex);
3904 /* number of remaining blocks in the extent */
3905 allocated = ext4_ext_get_actual_len(&newex) -
3906 (map->m_lblk - le32_to_cpu(newex.ee_block));
3911 /* find extent for this block */
3912 path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
3914 err = PTR_ERR(path);
3919 depth = ext_depth(inode);
3922 * consistent leaf must not be empty;
3923 * this situation is possible, though, _during_ tree modification;
3924 * this is why assert can't be put in ext4_ext_find_extent()
3926 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
3927 EXT4_ERROR_INODE(inode, "bad extent address "
3928 "lblock: %lu, depth: %d pblock %lld",
3929 (unsigned long) map->m_lblk, depth,
3930 path[depth].p_block);
3935 ex = path[depth].p_ext;
3937 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3938 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3939 unsigned short ee_len;
3942 * Uninitialized extents are treated as holes, except that
3943 * we split out initialized portions during a write.
3945 ee_len = ext4_ext_get_actual_len(ex);
3947 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
3949 /* if found extent covers block, simply return it */
3950 if (in_range(map->m_lblk, ee_block, ee_len)) {
3951 newblock = map->m_lblk - ee_block + ee_start;
3952 /* number of remaining blocks in the extent */
3953 allocated = ee_len - (map->m_lblk - ee_block);
3954 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
3955 ee_block, ee_len, newblock);
3958 * Do not put uninitialized extent
3961 if (!ext4_ext_is_uninitialized(ex)) {
3962 ext4_ext_put_in_cache(inode, ee_block,
3966 allocated = ext4_ext_handle_uninitialized_extents(
3967 handle, inode, map, path, flags,
3968 allocated, newblock);
3973 if ((sbi->s_cluster_ratio > 1) &&
3974 ext4_find_delalloc_cluster(inode, map->m_lblk))
3975 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3978 * requested block isn't allocated yet;
3979 * we couldn't try to create block if create flag is zero
3981 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3983 * put just found gap into cache to speed up
3984 * subsequent requests
3986 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
3991 * Okay, we need to do block allocation.
3993 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
3994 newex.ee_block = cpu_to_le32(map->m_lblk);
3995 cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3998 * If we are doing bigalloc, check to see if the extent returned
3999 * by ext4_ext_find_extent() implies a cluster we can use.
4001 if (cluster_offset && ex &&
4002 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4003 ar.len = allocated = map->m_len;
4004 newblock = map->m_pblk;
4005 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4006 goto got_allocated_blocks;
4009 /* find neighbour allocated blocks */
4010 ar.lleft = map->m_lblk;
4011 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4014 ar.lright = map->m_lblk;
4016 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4020 /* Check if the extent after searching to the right implies a
4021 * cluster we can use. */
4022 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4023 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4024 ar.len = allocated = map->m_len;
4025 newblock = map->m_pblk;
4026 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4027 goto got_allocated_blocks;
4031 * See if request is beyond maximum number of blocks we can have in
4032 * a single extent. For an initialized extent this limit is
4033 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
4034 * EXT_UNINIT_MAX_LEN.
4036 if (map->m_len > EXT_INIT_MAX_LEN &&
4037 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4038 map->m_len = EXT_INIT_MAX_LEN;
4039 else if (map->m_len > EXT_UNINIT_MAX_LEN &&
4040 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4041 map->m_len = EXT_UNINIT_MAX_LEN;
4043 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4044 newex.ee_len = cpu_to_le16(map->m_len);
4045 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4047 allocated = ext4_ext_get_actual_len(&newex);
4049 allocated = map->m_len;
4051 /* allocate new block */
4053 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4054 ar.logical = map->m_lblk;
4056 * We calculate the offset from the beginning of the cluster
4057 * for the logical block number, since when we allocate a
4058 * physical cluster, the physical block should start at the
4059 * same offset from the beginning of the cluster. This is
4060 * needed so that future calls to get_implied_cluster_alloc()
4063 offset = map->m_lblk & (sbi->s_cluster_ratio - 1);
4064 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4066 ar.logical -= offset;
4067 if (S_ISREG(inode->i_mode))
4068 ar.flags = EXT4_MB_HINT_DATA;
4070 /* disable in-core preallocation for non-regular files */
4072 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4073 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4074 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4077 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4078 ar.goal, newblock, allocated);
4080 allocated_clusters = ar.len;
4081 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4082 if (ar.len > allocated)
4085 got_allocated_blocks:
4086 /* try to insert new extent into found leaf and return */
4087 ext4_ext_store_pblock(&newex, newblock + offset);
4088 newex.ee_len = cpu_to_le16(ar.len);
4089 /* Mark uninitialized */
4090 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
4091 ext4_ext_mark_uninitialized(&newex);
4093 * io_end structure was created for every IO write to an
4094 * uninitialized extent. To avoid unnecessary conversion,
4095 * here we flag the IO that really needs the conversion.
4096 * For non asycn direct IO case, flag the inode state
4097 * that we need to perform conversion when IO is done.
4099 if ((flags & EXT4_GET_BLOCKS_PRE_IO))
4101 if (ext4_should_dioread_nolock(inode))
4102 map->m_flags |= EXT4_MAP_UNINIT;
4106 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4107 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4110 err = ext4_ext_insert_extent(handle, inode, path,
4113 if (!err && set_unwritten) {
4115 ext4_set_io_unwritten_flag(inode, io);
4117 ext4_set_inode_state(inode,
4118 EXT4_STATE_DIO_UNWRITTEN);
4121 if (err && free_on_err) {
4122 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4123 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4124 /* free data blocks we just allocated */
4125 /* not a good idea to call discard here directly,
4126 * but otherwise we'd need to call it every free() */
4127 ext4_discard_preallocations(inode);
4128 ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex),
4129 ext4_ext_get_actual_len(&newex), fb_flags);
4133 /* previous routine could use block we allocated */
4134 newblock = ext4_ext_pblock(&newex);
4135 allocated = ext4_ext_get_actual_len(&newex);
4136 if (allocated > map->m_len)
4137 allocated = map->m_len;
4138 map->m_flags |= EXT4_MAP_NEW;
4141 * Update reserved blocks/metadata blocks after successful
4142 * block allocation which had been deferred till now.
4144 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4145 unsigned int reserved_clusters;
4147 * Check how many clusters we had reserved this allocated range
4149 reserved_clusters = get_reserved_cluster_alloc(inode,
4150 map->m_lblk, allocated);
4151 if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
4152 if (reserved_clusters) {
4154 * We have clusters reserved for this range.
4155 * But since we are not doing actual allocation
4156 * and are simply using blocks from previously
4157 * allocated cluster, we should release the
4158 * reservation and not claim quota.
4160 ext4_da_update_reserve_space(inode,
4161 reserved_clusters, 0);
4164 BUG_ON(allocated_clusters < reserved_clusters);
4165 /* We will claim quota for all newly allocated blocks.*/
4166 ext4_da_update_reserve_space(inode, allocated_clusters,
4168 if (reserved_clusters < allocated_clusters) {
4169 struct ext4_inode_info *ei = EXT4_I(inode);
4170 int reservation = allocated_clusters -
4173 * It seems we claimed few clusters outside of
4174 * the range of this allocation. We should give
4175 * it back to the reservation pool. This can
4176 * happen in the following case:
4178 * * Suppose s_cluster_ratio is 4 (i.e., each
4179 * cluster has 4 blocks. Thus, the clusters
4180 * are [0-3],[4-7],[8-11]...
4181 * * First comes delayed allocation write for
4182 * logical blocks 10 & 11. Since there were no
4183 * previous delayed allocated blocks in the
4184 * range [8-11], we would reserve 1 cluster
4186 * * Next comes write for logical blocks 3 to 8.
4187 * In this case, we will reserve 2 clusters
4188 * (for [0-3] and [4-7]; and not for [8-11] as
4189 * that range has a delayed allocated blocks.
4190 * Thus total reserved clusters now becomes 3.
4191 * * Now, during the delayed allocation writeout
4192 * time, we will first write blocks [3-8] and
4193 * allocate 3 clusters for writing these
4194 * blocks. Also, we would claim all these
4195 * three clusters above.
4196 * * Now when we come here to writeout the
4197 * blocks [10-11], we would expect to claim
4198 * the reservation of 1 cluster we had made
4199 * (and we would claim it since there are no
4200 * more delayed allocated blocks in the range
4201 * [8-11]. But our reserved cluster count had
4202 * already gone to 0.
4204 * Thus, at the step 4 above when we determine
4205 * that there are still some unwritten delayed
4206 * allocated blocks outside of our current
4207 * block range, we should increment the
4208 * reserved clusters count so that when the
4209 * remaining blocks finally gets written, we
4212 dquot_reserve_block(inode,
4213 EXT4_C2B(sbi, reservation));
4214 spin_lock(&ei->i_block_reservation_lock);
4215 ei->i_reserved_data_blocks += reservation;
4216 spin_unlock(&ei->i_block_reservation_lock);
4222 * Cache the extent and update transaction to commit on fdatasync only
4223 * when it is _not_ an uninitialized extent.
4225 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
4226 ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock);
4227 ext4_update_inode_fsync_trans(handle, inode, 1);
4229 ext4_update_inode_fsync_trans(handle, inode, 0);
4231 if (allocated > map->m_len)
4232 allocated = map->m_len;
4233 ext4_ext_show_leaf(inode, path);
4234 map->m_flags |= EXT4_MAP_MAPPED;
4235 map->m_pblk = newblock;
4236 map->m_len = allocated;
4239 ext4_ext_drop_refs(path);
4244 trace_ext4_ext_map_blocks_exit(inode, map, err ? err : allocated);
4246 return err ? err : allocated;
4249 void ext4_ext_truncate(struct inode *inode)
4251 struct address_space *mapping = inode->i_mapping;
4252 struct super_block *sb = inode->i_sb;
4253 ext4_lblk_t last_block;
4259 * finish any pending end_io work so we won't run the risk of
4260 * converting any truncated blocks to initialized later
4262 ext4_flush_unwritten_io(inode);
4265 * probably first extent we're gonna free will be last in block
4267 err = ext4_writepage_trans_blocks(inode);
4268 handle = ext4_journal_start(inode, err);
4272 if (inode->i_size % PAGE_CACHE_SIZE != 0) {
4273 page_len = PAGE_CACHE_SIZE -
4274 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4276 err = ext4_discard_partial_page_buffers(handle,
4277 mapping, inode->i_size, page_len, 0);
4283 if (ext4_orphan_add(handle, inode))
4286 down_write(&EXT4_I(inode)->i_data_sem);
4287 ext4_ext_invalidate_cache(inode);
4289 ext4_discard_preallocations(inode);
4292 * TODO: optimization is possible here.
4293 * Probably we need not scan at all,
4294 * because page truncation is enough.
4297 /* we have to know where to truncate from in crash case */
4298 EXT4_I(inode)->i_disksize = inode->i_size;
4299 ext4_mark_inode_dirty(handle, inode);
4301 last_block = (inode->i_size + sb->s_blocksize - 1)
4302 >> EXT4_BLOCK_SIZE_BITS(sb);
4303 err = ext4_es_remove_extent(inode, last_block,
4304 EXT_MAX_BLOCKS - last_block);
4305 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4307 /* In a multi-transaction truncate, we only make the final
4308 * transaction synchronous.
4311 ext4_handle_sync(handle);
4313 up_write(&EXT4_I(inode)->i_data_sem);
4317 * If this was a simple ftruncate() and the file will remain alive,
4318 * then we need to clear up the orphan record which we created above.
4319 * However, if this was a real unlink then we were called by
4320 * ext4_delete_inode(), and we allow that function to clean up the
4321 * orphan info for us.
4324 ext4_orphan_del(handle, inode);
4326 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4327 ext4_mark_inode_dirty(handle, inode);
4328 ext4_journal_stop(handle);
4331 static void ext4_falloc_update_inode(struct inode *inode,
4332 int mode, loff_t new_size, int update_ctime)
4334 struct timespec now;
4337 now = current_fs_time(inode->i_sb);
4338 if (!timespec_equal(&inode->i_ctime, &now))
4339 inode->i_ctime = now;
4342 * Update only when preallocation was requested beyond
4345 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
4346 if (new_size > i_size_read(inode))
4347 i_size_write(inode, new_size);
4348 if (new_size > EXT4_I(inode)->i_disksize)
4349 ext4_update_i_disksize(inode, new_size);
4352 * Mark that we allocate beyond EOF so the subsequent truncate
4353 * can proceed even if the new size is the same as i_size.
4355 if (new_size > i_size_read(inode))
4356 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4362 * preallocate space for a file. This implements ext4's fallocate file
4363 * operation, which gets called from sys_fallocate system call.
4364 * For block-mapped files, posix_fallocate should fall back to the method
4365 * of writing zeroes to the required new blocks (the same behavior which is
4366 * expected for file systems which do not support fallocate() system call).
4368 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4370 struct inode *inode = file->f_path.dentry->d_inode;
4373 unsigned int max_blocks;
4378 struct ext4_map_blocks map;
4379 unsigned int credits, blkbits = inode->i_blkbits;
4382 * currently supporting (pre)allocate mode for extent-based
4385 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4388 /* Return error if mode is not supported */
4389 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
4392 if (mode & FALLOC_FL_PUNCH_HOLE)
4393 return ext4_punch_hole(file, offset, len);
4395 trace_ext4_fallocate_enter(inode, offset, len, mode);
4396 map.m_lblk = offset >> blkbits;
4398 * We can't just convert len to max_blocks because
4399 * If blocksize = 4096 offset = 3072 and len = 2048
4401 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4404 * credits to insert 1 extent into extent tree
4406 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4407 mutex_lock(&inode->i_mutex);
4408 ret = inode_newsize_ok(inode, (len + offset));
4410 mutex_unlock(&inode->i_mutex);
4411 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4414 flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
4415 if (mode & FALLOC_FL_KEEP_SIZE)
4416 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4418 * Don't normalize the request if it can fit in one extent so
4419 * that it doesn't get unnecessarily split into multiple
4422 if (len <= EXT_UNINIT_MAX_LEN << blkbits)
4423 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4425 /* Prevent race condition between unwritten */
4426 ext4_flush_unwritten_io(inode);
4428 while (ret >= 0 && ret < max_blocks) {
4429 map.m_lblk = map.m_lblk + ret;
4430 map.m_len = max_blocks = max_blocks - ret;
4431 handle = ext4_journal_start(inode, credits);
4432 if (IS_ERR(handle)) {
4433 ret = PTR_ERR(handle);
4436 ret = ext4_map_blocks(handle, inode, &map, flags);
4440 printk(KERN_ERR "%s: ext4_ext_map_blocks "
4441 "returned error inode#%lu, block=%u, "
4442 "max_blocks=%u", __func__,
4443 inode->i_ino, map.m_lblk, max_blocks);
4445 ext4_mark_inode_dirty(handle, inode);
4446 ret2 = ext4_journal_stop(handle);
4449 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
4450 blkbits) >> blkbits))
4451 new_size = offset + len;
4453 new_size = ((loff_t) map.m_lblk + ret) << blkbits;
4455 ext4_falloc_update_inode(inode, mode, new_size,
4456 (map.m_flags & EXT4_MAP_NEW));
4457 ext4_mark_inode_dirty(handle, inode);
4458 if ((file->f_flags & O_SYNC) && ret >= max_blocks)
4459 ext4_handle_sync(handle);
4460 ret2 = ext4_journal_stop(handle);
4464 if (ret == -ENOSPC &&
4465 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4469 mutex_unlock(&inode->i_mutex);
4470 trace_ext4_fallocate_exit(inode, offset, max_blocks,
4471 ret > 0 ? ret2 : ret);
4472 return ret > 0 ? ret2 : ret;
4476 * This function convert a range of blocks to written extents
4477 * The caller of this function will pass the start offset and the size.
4478 * all unwritten extents within this range will be converted to
4481 * This function is called from the direct IO end io call back
4482 * function, to convert the fallocated extents after IO is completed.
4483 * Returns 0 on success.
4485 int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
4489 unsigned int max_blocks;
4492 struct ext4_map_blocks map;
4493 unsigned int credits, blkbits = inode->i_blkbits;
4495 map.m_lblk = offset >> blkbits;
4497 * We can't just convert len to max_blocks because
4498 * If blocksize = 4096 offset = 3072 and len = 2048
4500 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
4503 * credits to insert 1 extent into extent tree
4505 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4506 while (ret >= 0 && ret < max_blocks) {
4508 map.m_len = (max_blocks -= ret);
4509 handle = ext4_journal_start(inode, credits);
4510 if (IS_ERR(handle)) {
4511 ret = PTR_ERR(handle);
4514 ret = ext4_map_blocks(handle, inode, &map,
4515 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4518 ext4_msg(inode->i_sb, KERN_ERR,
4519 "%s:%d: inode #%lu: block %u: len %u: "
4520 "ext4_ext_map_blocks returned %d",
4521 __func__, __LINE__, inode->i_ino, map.m_lblk,
4524 ext4_mark_inode_dirty(handle, inode);
4525 ret2 = ext4_journal_stop(handle);
4526 if (ret <= 0 || ret2 )
4529 return ret > 0 ? ret2 : ret;
4533 * If newex is not existing extent (newex->ec_start equals zero) find
4534 * delayed extent at start of newex and update newex accordingly and
4535 * return start of the next delayed extent.
4537 * If newex is existing extent (newex->ec_start is not equal zero)
4538 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
4539 * extent found. Leave newex unmodified.
4541 static int ext4_find_delayed_extent(struct inode *inode,
4542 struct ext4_ext_cache *newex)
4544 struct extent_status es;
4545 ext4_lblk_t next_del;
4547 es.start = newex->ec_block;
4548 next_del = ext4_es_find_extent(inode, &es);
4550 if (newex->ec_start == 0) {
4552 * No extent in extent-tree contains block @newex->ec_start,
4553 * then the block may stay in 1)a hole or 2)delayed-extent.
4559 if (es.start > newex->ec_block) {
4561 newex->ec_len = min(es.start - newex->ec_block,
4566 newex->ec_len = es.start + es.len - newex->ec_block;
4571 /* fiemap flags we can handle specified here */
4572 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4574 static int ext4_xattr_fiemap(struct inode *inode,
4575 struct fiemap_extent_info *fieinfo)
4579 __u32 flags = FIEMAP_EXTENT_LAST;
4580 int blockbits = inode->i_sb->s_blocksize_bits;
4584 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4585 struct ext4_iloc iloc;
4586 int offset; /* offset of xattr in inode */
4588 error = ext4_get_inode_loc(inode, &iloc);
4591 physical = iloc.bh->b_blocknr << blockbits;
4592 offset = EXT4_GOOD_OLD_INODE_SIZE +
4593 EXT4_I(inode)->i_extra_isize;
4595 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4596 flags |= FIEMAP_EXTENT_DATA_INLINE;
4598 } else { /* external block */
4599 physical = EXT4_I(inode)->i_file_acl << blockbits;
4600 length = inode->i_sb->s_blocksize;
4604 error = fiemap_fill_next_extent(fieinfo, 0, physical,
4606 return (error < 0 ? error : 0);
4610 * ext4_ext_punch_hole
4612 * Punches a hole of "length" bytes in a file starting
4615 * @inode: The inode of the file to punch a hole in
4616 * @offset: The starting byte offset of the hole
4617 * @length: The length of the hole
4619 * Returns the number of blocks removed or negative on err
4621 int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
4623 struct inode *inode = file->f_path.dentry->d_inode;
4624 struct super_block *sb = inode->i_sb;
4625 ext4_lblk_t first_block, stop_block;
4626 struct address_space *mapping = inode->i_mapping;
4628 loff_t first_page, last_page, page_len;
4629 loff_t first_page_offset, last_page_offset;
4630 int credits, err = 0;
4633 * Write out all dirty pages to avoid race conditions
4634 * Then release them.
4636 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
4637 err = filemap_write_and_wait_range(mapping,
4638 offset, offset + length - 1);
4644 mutex_lock(&inode->i_mutex);
4645 /* It's not possible punch hole on append only file */
4646 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {
4650 if (IS_SWAPFILE(inode)) {
4655 /* No need to punch hole beyond i_size */
4656 if (offset >= inode->i_size)
4660 * If the hole extends beyond i_size, set the hole
4661 * to end after the page that contains i_size
4663 if (offset + length > inode->i_size) {
4664 length = inode->i_size +
4665 PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) -
4669 first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
4670 last_page = (offset + length) >> PAGE_CACHE_SHIFT;
4672 first_page_offset = first_page << PAGE_CACHE_SHIFT;
4673 last_page_offset = last_page << PAGE_CACHE_SHIFT;
4675 /* Now release the pages */
4676 if (last_page_offset > first_page_offset) {
4677 truncate_pagecache_range(inode, first_page_offset,
4678 last_page_offset - 1);
4681 /* Wait all existing dio workers, newcomers will block on i_mutex */
4682 ext4_inode_block_unlocked_dio(inode);
4683 err = ext4_flush_unwritten_io(inode);
4686 inode_dio_wait(inode);
4688 credits = ext4_writepage_trans_blocks(inode);
4689 handle = ext4_journal_start(inode, credits);
4690 if (IS_ERR(handle)) {
4691 err = PTR_ERR(handle);
4697 * Now we need to zero out the non-page-aligned data in the
4698 * pages at the start and tail of the hole, and unmap the buffer
4699 * heads for the block aligned regions of the page that were
4700 * completely zeroed.
4702 if (first_page > last_page) {
4704 * If the file space being truncated is contained within a page
4705 * just zero out and unmap the middle of that page
4707 err = ext4_discard_partial_page_buffers(handle,
4708 mapping, offset, length, 0);
4714 * zero out and unmap the partial page that contains
4715 * the start of the hole
4717 page_len = first_page_offset - offset;
4719 err = ext4_discard_partial_page_buffers(handle, mapping,
4720 offset, page_len, 0);
4726 * zero out and unmap the partial page that contains
4727 * the end of the hole
4729 page_len = offset + length - last_page_offset;
4731 err = ext4_discard_partial_page_buffers(handle, mapping,
4732 last_page_offset, page_len, 0);
4739 * If i_size is contained in the last page, we need to
4740 * unmap and zero the partial page after i_size
4742 if (inode->i_size >> PAGE_CACHE_SHIFT == last_page &&
4743 inode->i_size % PAGE_CACHE_SIZE != 0) {
4745 page_len = PAGE_CACHE_SIZE -
4746 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4749 err = ext4_discard_partial_page_buffers(handle,
4750 mapping, inode->i_size, page_len, 0);
4757 first_block = (offset + sb->s_blocksize - 1) >>
4758 EXT4_BLOCK_SIZE_BITS(sb);
4759 stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
4761 /* If there are no blocks to remove, return now */
4762 if (first_block >= stop_block)
4765 down_write(&EXT4_I(inode)->i_data_sem);
4766 ext4_ext_invalidate_cache(inode);
4767 ext4_discard_preallocations(inode);
4769 err = ext4_es_remove_extent(inode, first_block,
4770 stop_block - first_block);
4771 err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
4773 ext4_ext_invalidate_cache(inode);
4774 ext4_discard_preallocations(inode);
4777 ext4_handle_sync(handle);
4779 up_write(&EXT4_I(inode)->i_data_sem);
4782 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4783 ext4_mark_inode_dirty(handle, inode);
4784 ext4_journal_stop(handle);
4786 ext4_inode_resume_unlocked_dio(inode);
4788 mutex_unlock(&inode->i_mutex);
4792 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4793 __u64 start, __u64 len)
4795 ext4_lblk_t start_blk;
4798 /* fallback to generic here if not in extents fmt */
4799 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4800 return generic_block_fiemap(inode, fieinfo, start, len,
4803 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
4806 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4807 error = ext4_xattr_fiemap(inode, fieinfo);
4809 ext4_lblk_t len_blks;
4812 start_blk = start >> inode->i_sb->s_blocksize_bits;
4813 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
4814 if (last_blk >= EXT_MAX_BLOCKS)
4815 last_blk = EXT_MAX_BLOCKS-1;
4816 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
4819 * Walk the extent tree gathering extent information
4820 * and pushing extents back to the user.
4822 error = ext4_fill_fiemap_extents(inode, start_blk,