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"
47 #include <trace/events/ext4.h>
50 * used by extent splitting.
52 #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
54 #define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
55 #define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
57 #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
58 #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
60 static __le32 ext4_extent_block_csum(struct inode *inode,
61 struct ext4_extent_header *eh)
63 struct ext4_inode_info *ei = EXT4_I(inode);
64 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
67 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
68 EXT4_EXTENT_TAIL_OFFSET(eh));
69 return cpu_to_le32(csum);
72 static int ext4_extent_block_csum_verify(struct inode *inode,
73 struct ext4_extent_header *eh)
75 struct ext4_extent_tail *et;
77 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
78 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
81 et = find_ext4_extent_tail(eh);
82 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
87 static void ext4_extent_block_csum_set(struct inode *inode,
88 struct ext4_extent_header *eh)
90 struct ext4_extent_tail *et;
92 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
93 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
96 et = find_ext4_extent_tail(eh);
97 et->et_checksum = ext4_extent_block_csum(inode, eh);
100 static int ext4_split_extent(handle_t *handle,
102 struct ext4_ext_path *path,
103 struct ext4_map_blocks *map,
107 static int ext4_split_extent_at(handle_t *handle,
109 struct ext4_ext_path *path,
114 static int ext4_find_delayed_extent(struct inode *inode,
115 struct extent_status *newes);
117 static int ext4_ext_truncate_extend_restart(handle_t *handle,
123 if (!ext4_handle_valid(handle))
125 if (handle->h_buffer_credits > needed)
127 err = ext4_journal_extend(handle, needed);
130 err = ext4_truncate_restart_trans(handle, inode, needed);
142 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
143 struct ext4_ext_path *path)
146 /* path points to block */
147 return ext4_journal_get_write_access(handle, path->p_bh);
149 /* path points to leaf/index in inode body */
150 /* we use in-core data, no need to protect them */
160 #define ext4_ext_dirty(handle, inode, path) \
161 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
162 static int __ext4_ext_dirty(const char *where, unsigned int line,
163 handle_t *handle, struct inode *inode,
164 struct ext4_ext_path *path)
168 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
169 /* path points to block */
170 err = __ext4_handle_dirty_metadata(where, line, handle,
173 /* path points to leaf/index in inode body */
174 err = ext4_mark_inode_dirty(handle, inode);
179 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
180 struct ext4_ext_path *path,
184 int depth = path->p_depth;
185 struct ext4_extent *ex;
188 * Try to predict block placement assuming that we are
189 * filling in a file which will eventually be
190 * non-sparse --- i.e., in the case of libbfd writing
191 * an ELF object sections out-of-order but in a way
192 * the eventually results in a contiguous object or
193 * executable file, or some database extending a table
194 * space file. However, this is actually somewhat
195 * non-ideal if we are writing a sparse file such as
196 * qemu or KVM writing a raw image file that is going
197 * to stay fairly sparse, since it will end up
198 * fragmenting the file system's free space. Maybe we
199 * should have some hueristics or some way to allow
200 * userspace to pass a hint to file system,
201 * especially if the latter case turns out to be
204 ex = path[depth].p_ext;
206 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
207 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
209 if (block > ext_block)
210 return ext_pblk + (block - ext_block);
212 return ext_pblk - (ext_block - block);
215 /* it looks like index is empty;
216 * try to find starting block from index itself */
217 if (path[depth].p_bh)
218 return path[depth].p_bh->b_blocknr;
221 /* OK. use inode's group */
222 return ext4_inode_to_goal_block(inode);
226 * Allocation for a meta data block
229 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
230 struct ext4_ext_path *path,
231 struct ext4_extent *ex, int *err, unsigned int flags)
233 ext4_fsblk_t goal, newblock;
235 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
236 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
241 static inline int ext4_ext_space_block(struct inode *inode, int check)
245 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
246 / sizeof(struct ext4_extent);
247 #ifdef AGGRESSIVE_TEST
248 if (!check && size > 6)
254 static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
258 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
259 / sizeof(struct ext4_extent_idx);
260 #ifdef AGGRESSIVE_TEST
261 if (!check && size > 5)
267 static inline int ext4_ext_space_root(struct inode *inode, int check)
271 size = sizeof(EXT4_I(inode)->i_data);
272 size -= sizeof(struct ext4_extent_header);
273 size /= sizeof(struct ext4_extent);
274 #ifdef AGGRESSIVE_TEST
275 if (!check && size > 3)
281 static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
285 size = sizeof(EXT4_I(inode)->i_data);
286 size -= sizeof(struct ext4_extent_header);
287 size /= sizeof(struct ext4_extent_idx);
288 #ifdef AGGRESSIVE_TEST
289 if (!check && size > 4)
296 * Calculate the number of metadata blocks needed
297 * to allocate @blocks
298 * Worse case is one block per extent
300 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
302 struct ext4_inode_info *ei = EXT4_I(inode);
305 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
306 / sizeof(struct ext4_extent_idx));
309 * If the new delayed allocation block is contiguous with the
310 * previous da block, it can share index blocks with the
311 * previous block, so we only need to allocate a new index
312 * block every idxs leaf blocks. At ldxs**2 blocks, we need
313 * an additional index block, and at ldxs**3 blocks, yet
314 * another index blocks.
316 if (ei->i_da_metadata_calc_len &&
317 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
320 if ((ei->i_da_metadata_calc_len % idxs) == 0)
322 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
324 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
326 ei->i_da_metadata_calc_len = 0;
328 ei->i_da_metadata_calc_len++;
329 ei->i_da_metadata_calc_last_lblock++;
334 * In the worst case we need a new set of index blocks at
335 * every level of the inode's extent tree.
337 ei->i_da_metadata_calc_len = 1;
338 ei->i_da_metadata_calc_last_lblock = lblock;
339 return ext_depth(inode) + 1;
343 ext4_ext_max_entries(struct inode *inode, int depth)
347 if (depth == ext_depth(inode)) {
349 max = ext4_ext_space_root(inode, 1);
351 max = ext4_ext_space_root_idx(inode, 1);
354 max = ext4_ext_space_block(inode, 1);
356 max = ext4_ext_space_block_idx(inode, 1);
362 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
364 ext4_fsblk_t block = ext4_ext_pblock(ext);
365 int len = ext4_ext_get_actual_len(ext);
369 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
372 static int ext4_valid_extent_idx(struct inode *inode,
373 struct ext4_extent_idx *ext_idx)
375 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
377 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
380 static int ext4_valid_extent_entries(struct inode *inode,
381 struct ext4_extent_header *eh,
384 unsigned short entries;
385 if (eh->eh_entries == 0)
388 entries = le16_to_cpu(eh->eh_entries);
392 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
394 if (!ext4_valid_extent(inode, ext))
400 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
402 if (!ext4_valid_extent_idx(inode, ext_idx))
411 static int __ext4_ext_check(const char *function, unsigned int line,
412 struct inode *inode, struct ext4_extent_header *eh,
415 const char *error_msg;
418 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
419 error_msg = "invalid magic";
422 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
423 error_msg = "unexpected eh_depth";
426 if (unlikely(eh->eh_max == 0)) {
427 error_msg = "invalid eh_max";
430 max = ext4_ext_max_entries(inode, depth);
431 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
432 error_msg = "too large eh_max";
435 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
436 error_msg = "invalid eh_entries";
439 if (!ext4_valid_extent_entries(inode, eh, depth)) {
440 error_msg = "invalid extent entries";
443 /* Verify checksum on non-root extent tree nodes */
444 if (ext_depth(inode) != depth &&
445 !ext4_extent_block_csum_verify(inode, eh)) {
446 error_msg = "extent tree corrupted";
452 ext4_error_inode(inode, function, line, 0,
453 "bad header/extent: %s - magic %x, "
454 "entries %u, max %u(%u), depth %u(%u)",
455 error_msg, le16_to_cpu(eh->eh_magic),
456 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
457 max, le16_to_cpu(eh->eh_depth), depth);
462 #define ext4_ext_check(inode, eh, depth) \
463 __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
465 int ext4_ext_check_inode(struct inode *inode)
467 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
470 static int __ext4_ext_check_block(const char *function, unsigned int line,
472 struct ext4_extent_header *eh,
474 struct buffer_head *bh)
478 if (buffer_verified(bh))
480 ret = ext4_ext_check(inode, eh, depth);
483 set_buffer_verified(bh);
487 #define ext4_ext_check_block(inode, eh, depth, bh) \
488 __ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
491 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
493 int k, l = path->p_depth;
496 for (k = 0; k <= l; k++, path++) {
498 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
499 ext4_idx_pblock(path->p_idx));
500 } else if (path->p_ext) {
501 ext_debug(" %d:[%d]%d:%llu ",
502 le32_to_cpu(path->p_ext->ee_block),
503 ext4_ext_is_uninitialized(path->p_ext),
504 ext4_ext_get_actual_len(path->p_ext),
505 ext4_ext_pblock(path->p_ext));
512 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
514 int depth = ext_depth(inode);
515 struct ext4_extent_header *eh;
516 struct ext4_extent *ex;
522 eh = path[depth].p_hdr;
523 ex = EXT_FIRST_EXTENT(eh);
525 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
527 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
528 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
529 ext4_ext_is_uninitialized(ex),
530 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
535 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
536 ext4_fsblk_t newblock, int level)
538 int depth = ext_depth(inode);
539 struct ext4_extent *ex;
541 if (depth != level) {
542 struct ext4_extent_idx *idx;
543 idx = path[level].p_idx;
544 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
545 ext_debug("%d: move %d:%llu in new index %llu\n", level,
546 le32_to_cpu(idx->ei_block),
547 ext4_idx_pblock(idx),
555 ex = path[depth].p_ext;
556 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
557 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
558 le32_to_cpu(ex->ee_block),
560 ext4_ext_is_uninitialized(ex),
561 ext4_ext_get_actual_len(ex),
568 #define ext4_ext_show_path(inode, path)
569 #define ext4_ext_show_leaf(inode, path)
570 #define ext4_ext_show_move(inode, path, newblock, level)
573 void ext4_ext_drop_refs(struct ext4_ext_path *path)
575 int depth = path->p_depth;
578 for (i = 0; i <= depth; i++, path++)
586 * ext4_ext_binsearch_idx:
587 * binary search for the closest index of the given block
588 * the header must be checked before calling this
591 ext4_ext_binsearch_idx(struct inode *inode,
592 struct ext4_ext_path *path, ext4_lblk_t block)
594 struct ext4_extent_header *eh = path->p_hdr;
595 struct ext4_extent_idx *r, *l, *m;
598 ext_debug("binsearch for %u(idx): ", block);
600 l = EXT_FIRST_INDEX(eh) + 1;
601 r = EXT_LAST_INDEX(eh);
604 if (block < le32_to_cpu(m->ei_block))
608 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
609 m, le32_to_cpu(m->ei_block),
610 r, le32_to_cpu(r->ei_block));
614 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
615 ext4_idx_pblock(path->p_idx));
617 #ifdef CHECK_BINSEARCH
619 struct ext4_extent_idx *chix, *ix;
622 chix = ix = EXT_FIRST_INDEX(eh);
623 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
625 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
626 printk(KERN_DEBUG "k=%d, ix=0x%p, "
628 ix, EXT_FIRST_INDEX(eh));
629 printk(KERN_DEBUG "%u <= %u\n",
630 le32_to_cpu(ix->ei_block),
631 le32_to_cpu(ix[-1].ei_block));
633 BUG_ON(k && le32_to_cpu(ix->ei_block)
634 <= le32_to_cpu(ix[-1].ei_block));
635 if (block < le32_to_cpu(ix->ei_block))
639 BUG_ON(chix != path->p_idx);
646 * ext4_ext_binsearch:
647 * binary search for closest extent of the given block
648 * the header must be checked before calling this
651 ext4_ext_binsearch(struct inode *inode,
652 struct ext4_ext_path *path, ext4_lblk_t block)
654 struct ext4_extent_header *eh = path->p_hdr;
655 struct ext4_extent *r, *l, *m;
657 if (eh->eh_entries == 0) {
659 * this leaf is empty:
660 * we get such a leaf in split/add case
665 ext_debug("binsearch for %u: ", block);
667 l = EXT_FIRST_EXTENT(eh) + 1;
668 r = EXT_LAST_EXTENT(eh);
672 if (block < le32_to_cpu(m->ee_block))
676 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
677 m, le32_to_cpu(m->ee_block),
678 r, le32_to_cpu(r->ee_block));
682 ext_debug(" -> %d:%llu:[%d]%d ",
683 le32_to_cpu(path->p_ext->ee_block),
684 ext4_ext_pblock(path->p_ext),
685 ext4_ext_is_uninitialized(path->p_ext),
686 ext4_ext_get_actual_len(path->p_ext));
688 #ifdef CHECK_BINSEARCH
690 struct ext4_extent *chex, *ex;
693 chex = ex = EXT_FIRST_EXTENT(eh);
694 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
695 BUG_ON(k && le32_to_cpu(ex->ee_block)
696 <= le32_to_cpu(ex[-1].ee_block));
697 if (block < le32_to_cpu(ex->ee_block))
701 BUG_ON(chex != path->p_ext);
707 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
709 struct ext4_extent_header *eh;
711 eh = ext_inode_hdr(inode);
714 eh->eh_magic = EXT4_EXT_MAGIC;
715 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
716 ext4_mark_inode_dirty(handle, 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;
729 eh = ext_inode_hdr(inode);
730 depth = ext_depth(inode);
732 /* account possible depth increase */
734 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
737 return ERR_PTR(-ENOMEM);
744 /* walk through the tree */
746 ext_debug("depth %d: num %d, max %d\n",
747 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
749 ext4_ext_binsearch_idx(inode, path + ppos, block);
750 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
751 path[ppos].p_depth = i;
752 path[ppos].p_ext = NULL;
754 bh = sb_getblk(inode->i_sb, path[ppos].p_block);
759 if (!bh_uptodate_or_lock(bh)) {
760 trace_ext4_ext_load_extent(inode, block,
762 ret = bh_submit_read(bh);
768 eh = ext_block_hdr(bh);
770 if (unlikely(ppos > depth)) {
772 EXT4_ERROR_INODE(inode,
773 "ppos %d > depth %d", ppos, depth);
777 path[ppos].p_bh = bh;
778 path[ppos].p_hdr = eh;
781 ret = ext4_ext_check_block(inode, eh, i, bh);
786 path[ppos].p_depth = i;
787 path[ppos].p_ext = NULL;
788 path[ppos].p_idx = NULL;
791 ext4_ext_binsearch(inode, path + ppos, block);
792 /* if not an empty leaf */
793 if (path[ppos].p_ext)
794 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
796 ext4_ext_show_path(inode, path);
801 ext4_ext_drop_refs(path);
808 * ext4_ext_insert_index:
809 * insert new index [@logical;@ptr] into the block at @curp;
810 * check where to insert: before @curp or after @curp
812 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
813 struct ext4_ext_path *curp,
814 int logical, ext4_fsblk_t ptr)
816 struct ext4_extent_idx *ix;
819 err = ext4_ext_get_access(handle, inode, curp);
823 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
824 EXT4_ERROR_INODE(inode,
825 "logical %d == ei_block %d!",
826 logical, le32_to_cpu(curp->p_idx->ei_block));
830 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
831 >= le16_to_cpu(curp->p_hdr->eh_max))) {
832 EXT4_ERROR_INODE(inode,
833 "eh_entries %d >= eh_max %d!",
834 le16_to_cpu(curp->p_hdr->eh_entries),
835 le16_to_cpu(curp->p_hdr->eh_max));
839 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
841 ext_debug("insert new index %d after: %llu\n", logical, ptr);
842 ix = curp->p_idx + 1;
845 ext_debug("insert new index %d before: %llu\n", logical, ptr);
849 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
852 ext_debug("insert new index %d: "
853 "move %d indices from 0x%p to 0x%p\n",
854 logical, len, ix, ix + 1);
855 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
858 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
859 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
863 ix->ei_block = cpu_to_le32(logical);
864 ext4_idx_store_pblock(ix, ptr);
865 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
867 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
868 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
872 err = ext4_ext_dirty(handle, inode, curp);
873 ext4_std_error(inode->i_sb, err);
880 * inserts new subtree into the path, using free index entry
882 * - allocates all needed blocks (new leaf and all intermediate index blocks)
883 * - makes decision where to split
884 * - moves remaining extents and index entries (right to the split point)
885 * into the newly allocated blocks
886 * - initializes subtree
888 static int ext4_ext_split(handle_t *handle, struct inode *inode,
890 struct ext4_ext_path *path,
891 struct ext4_extent *newext, int at)
893 struct buffer_head *bh = NULL;
894 int depth = ext_depth(inode);
895 struct ext4_extent_header *neh;
896 struct ext4_extent_idx *fidx;
898 ext4_fsblk_t newblock, oldblock;
900 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
903 /* make decision: where to split? */
904 /* FIXME: now decision is simplest: at current extent */
906 /* if current leaf will be split, then we should use
907 * border from split point */
908 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
909 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
912 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
913 border = path[depth].p_ext[1].ee_block;
914 ext_debug("leaf will be split."
915 " next leaf starts at %d\n",
916 le32_to_cpu(border));
918 border = newext->ee_block;
919 ext_debug("leaf will be added."
920 " next leaf starts at %d\n",
921 le32_to_cpu(border));
925 * If error occurs, then we break processing
926 * and mark filesystem read-only. index won't
927 * be inserted and tree will be in consistent
928 * state. Next mount will repair buffers too.
932 * Get array to track all allocated blocks.
933 * We need this to handle errors and free blocks
936 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
940 /* allocate all needed blocks */
941 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
942 for (a = 0; a < depth - at; a++) {
943 newblock = ext4_ext_new_meta_block(handle, inode, path,
944 newext, &err, flags);
947 ablocks[a] = newblock;
950 /* initialize new leaf */
951 newblock = ablocks[--a];
952 if (unlikely(newblock == 0)) {
953 EXT4_ERROR_INODE(inode, "newblock == 0!");
957 bh = sb_getblk(inode->i_sb, newblock);
964 err = ext4_journal_get_create_access(handle, bh);
968 neh = ext_block_hdr(bh);
970 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
971 neh->eh_magic = EXT4_EXT_MAGIC;
974 /* move remainder of path[depth] to the new leaf */
975 if (unlikely(path[depth].p_hdr->eh_entries !=
976 path[depth].p_hdr->eh_max)) {
977 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
978 path[depth].p_hdr->eh_entries,
979 path[depth].p_hdr->eh_max);
983 /* start copy from next extent */
984 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
985 ext4_ext_show_move(inode, path, newblock, depth);
987 struct ext4_extent *ex;
988 ex = EXT_FIRST_EXTENT(neh);
989 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
990 le16_add_cpu(&neh->eh_entries, m);
993 ext4_extent_block_csum_set(inode, neh);
994 set_buffer_uptodate(bh);
997 err = ext4_handle_dirty_metadata(handle, inode, bh);
1003 /* correct old leaf */
1005 err = ext4_ext_get_access(handle, inode, path + depth);
1008 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1009 err = ext4_ext_dirty(handle, inode, path + depth);
1015 /* create intermediate indexes */
1017 if (unlikely(k < 0)) {
1018 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1023 ext_debug("create %d intermediate indices\n", k);
1024 /* insert new index into current index block */
1025 /* current depth stored in i var */
1028 oldblock = newblock;
1029 newblock = ablocks[--a];
1030 bh = sb_getblk(inode->i_sb, newblock);
1031 if (unlikely(!bh)) {
1037 err = ext4_journal_get_create_access(handle, bh);
1041 neh = ext_block_hdr(bh);
1042 neh->eh_entries = cpu_to_le16(1);
1043 neh->eh_magic = EXT4_EXT_MAGIC;
1044 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1045 neh->eh_depth = cpu_to_le16(depth - i);
1046 fidx = EXT_FIRST_INDEX(neh);
1047 fidx->ei_block = border;
1048 ext4_idx_store_pblock(fidx, oldblock);
1050 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1051 i, newblock, le32_to_cpu(border), oldblock);
1053 /* move remainder of path[i] to the new index block */
1054 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1055 EXT_LAST_INDEX(path[i].p_hdr))) {
1056 EXT4_ERROR_INODE(inode,
1057 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1058 le32_to_cpu(path[i].p_ext->ee_block));
1062 /* start copy indexes */
1063 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1064 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1065 EXT_MAX_INDEX(path[i].p_hdr));
1066 ext4_ext_show_move(inode, path, newblock, i);
1068 memmove(++fidx, path[i].p_idx,
1069 sizeof(struct ext4_extent_idx) * m);
1070 le16_add_cpu(&neh->eh_entries, m);
1072 ext4_extent_block_csum_set(inode, neh);
1073 set_buffer_uptodate(bh);
1076 err = ext4_handle_dirty_metadata(handle, inode, bh);
1082 /* correct old index */
1084 err = ext4_ext_get_access(handle, inode, path + i);
1087 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1088 err = ext4_ext_dirty(handle, inode, path + i);
1096 /* insert new index */
1097 err = ext4_ext_insert_index(handle, inode, path + at,
1098 le32_to_cpu(border), newblock);
1102 if (buffer_locked(bh))
1108 /* free all allocated blocks in error case */
1109 for (i = 0; i < depth; i++) {
1112 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1113 EXT4_FREE_BLOCKS_METADATA);
1122 * ext4_ext_grow_indepth:
1123 * implements tree growing procedure:
1124 * - allocates new block
1125 * - moves top-level data (index block or leaf) into the new block
1126 * - initializes new top-level, creating index that points to the
1127 * just created block
1129 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1131 struct ext4_extent *newext)
1133 struct ext4_extent_header *neh;
1134 struct buffer_head *bh;
1135 ext4_fsblk_t newblock;
1138 newblock = ext4_ext_new_meta_block(handle, inode, NULL,
1139 newext, &err, flags);
1143 bh = sb_getblk(inode->i_sb, newblock);
1148 err = ext4_journal_get_create_access(handle, bh);
1154 /* move top-level index/leaf into new block */
1155 memmove(bh->b_data, EXT4_I(inode)->i_data,
1156 sizeof(EXT4_I(inode)->i_data));
1158 /* set size of new block */
1159 neh = ext_block_hdr(bh);
1160 /* old root could have indexes or leaves
1161 * so calculate e_max right way */
1162 if (ext_depth(inode))
1163 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1165 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1166 neh->eh_magic = EXT4_EXT_MAGIC;
1167 ext4_extent_block_csum_set(inode, neh);
1168 set_buffer_uptodate(bh);
1171 err = ext4_handle_dirty_metadata(handle, inode, bh);
1175 /* Update top-level index: num,max,pointer */
1176 neh = ext_inode_hdr(inode);
1177 neh->eh_entries = cpu_to_le16(1);
1178 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1179 if (neh->eh_depth == 0) {
1180 /* Root extent block becomes index block */
1181 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1182 EXT_FIRST_INDEX(neh)->ei_block =
1183 EXT_FIRST_EXTENT(neh)->ee_block;
1185 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1186 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1187 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1188 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1190 le16_add_cpu(&neh->eh_depth, 1);
1191 ext4_mark_inode_dirty(handle, inode);
1199 * ext4_ext_create_new_leaf:
1200 * finds empty index and adds new leaf.
1201 * if no free index is found, then it requests in-depth growing.
1203 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1205 struct ext4_ext_path *path,
1206 struct ext4_extent *newext)
1208 struct ext4_ext_path *curp;
1209 int depth, i, err = 0;
1212 i = depth = ext_depth(inode);
1214 /* walk up to the tree and look for free index entry */
1215 curp = path + depth;
1216 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1221 /* we use already allocated block for index block,
1222 * so subsequent data blocks should be contiguous */
1223 if (EXT_HAS_FREE_INDEX(curp)) {
1224 /* if we found index with free entry, then use that
1225 * entry: create all needed subtree and add new leaf */
1226 err = ext4_ext_split(handle, inode, flags, path, newext, i);
1231 ext4_ext_drop_refs(path);
1232 path = ext4_ext_find_extent(inode,
1233 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1236 err = PTR_ERR(path);
1238 /* tree is full, time to grow in depth */
1239 err = ext4_ext_grow_indepth(handle, inode, flags, newext);
1244 ext4_ext_drop_refs(path);
1245 path = ext4_ext_find_extent(inode,
1246 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1249 err = PTR_ERR(path);
1254 * only first (depth 0 -> 1) produces free space;
1255 * in all other cases we have to split the grown tree
1257 depth = ext_depth(inode);
1258 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1259 /* now we need to split */
1269 * search the closest allocated block to the left for *logical
1270 * and returns it at @logical + it's physical address at @phys
1271 * if *logical is the smallest allocated block, the function
1272 * returns 0 at @phys
1273 * return value contains 0 (success) or error code
1275 static int ext4_ext_search_left(struct inode *inode,
1276 struct ext4_ext_path *path,
1277 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1279 struct ext4_extent_idx *ix;
1280 struct ext4_extent *ex;
1283 if (unlikely(path == NULL)) {
1284 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1287 depth = path->p_depth;
1290 if (depth == 0 && path->p_ext == NULL)
1293 /* usually extent in the path covers blocks smaller
1294 * then *logical, but it can be that extent is the
1295 * first one in the file */
1297 ex = path[depth].p_ext;
1298 ee_len = ext4_ext_get_actual_len(ex);
1299 if (*logical < le32_to_cpu(ex->ee_block)) {
1300 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1301 EXT4_ERROR_INODE(inode,
1302 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1303 *logical, le32_to_cpu(ex->ee_block));
1306 while (--depth >= 0) {
1307 ix = path[depth].p_idx;
1308 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1309 EXT4_ERROR_INODE(inode,
1310 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1311 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1312 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1313 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1321 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1322 EXT4_ERROR_INODE(inode,
1323 "logical %d < ee_block %d + ee_len %d!",
1324 *logical, le32_to_cpu(ex->ee_block), ee_len);
1328 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1329 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1334 * search the closest allocated block to the right for *logical
1335 * and returns it at @logical + it's physical address at @phys
1336 * if *logical is the largest allocated block, the function
1337 * returns 0 at @phys
1338 * return value contains 0 (success) or error code
1340 static int ext4_ext_search_right(struct inode *inode,
1341 struct ext4_ext_path *path,
1342 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1343 struct ext4_extent **ret_ex)
1345 struct buffer_head *bh = NULL;
1346 struct ext4_extent_header *eh;
1347 struct ext4_extent_idx *ix;
1348 struct ext4_extent *ex;
1350 int depth; /* Note, NOT eh_depth; depth from top of tree */
1353 if (unlikely(path == NULL)) {
1354 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1357 depth = path->p_depth;
1360 if (depth == 0 && path->p_ext == NULL)
1363 /* usually extent in the path covers blocks smaller
1364 * then *logical, but it can be that extent is the
1365 * first one in the file */
1367 ex = path[depth].p_ext;
1368 ee_len = ext4_ext_get_actual_len(ex);
1369 if (*logical < le32_to_cpu(ex->ee_block)) {
1370 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1371 EXT4_ERROR_INODE(inode,
1372 "first_extent(path[%d].p_hdr) != ex",
1376 while (--depth >= 0) {
1377 ix = path[depth].p_idx;
1378 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1379 EXT4_ERROR_INODE(inode,
1380 "ix != EXT_FIRST_INDEX *logical %d!",
1388 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1389 EXT4_ERROR_INODE(inode,
1390 "logical %d < ee_block %d + ee_len %d!",
1391 *logical, le32_to_cpu(ex->ee_block), ee_len);
1395 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1396 /* next allocated block in this leaf */
1401 /* go up and search for index to the right */
1402 while (--depth >= 0) {
1403 ix = path[depth].p_idx;
1404 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1408 /* we've gone up to the root and found no index to the right */
1412 /* we've found index to the right, let's
1413 * follow it and find the closest allocated
1414 * block to the right */
1416 block = ext4_idx_pblock(ix);
1417 while (++depth < path->p_depth) {
1418 bh = sb_bread(inode->i_sb, block);
1421 eh = ext_block_hdr(bh);
1422 /* subtract from p_depth to get proper eh_depth */
1423 if (ext4_ext_check_block(inode, eh,
1424 path->p_depth - depth, bh)) {
1428 ix = EXT_FIRST_INDEX(eh);
1429 block = ext4_idx_pblock(ix);
1433 bh = sb_bread(inode->i_sb, block);
1436 eh = ext_block_hdr(bh);
1437 if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
1441 ex = EXT_FIRST_EXTENT(eh);
1443 *logical = le32_to_cpu(ex->ee_block);
1444 *phys = ext4_ext_pblock(ex);
1452 * ext4_ext_next_allocated_block:
1453 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1454 * NOTE: it considers block number from index entry as
1455 * allocated block. Thus, index entries have to be consistent
1459 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1463 BUG_ON(path == NULL);
1464 depth = path->p_depth;
1466 if (depth == 0 && path->p_ext == NULL)
1467 return EXT_MAX_BLOCKS;
1469 while (depth >= 0) {
1470 if (depth == path->p_depth) {
1472 if (path[depth].p_ext &&
1473 path[depth].p_ext !=
1474 EXT_LAST_EXTENT(path[depth].p_hdr))
1475 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1478 if (path[depth].p_idx !=
1479 EXT_LAST_INDEX(path[depth].p_hdr))
1480 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1485 return EXT_MAX_BLOCKS;
1489 * ext4_ext_next_leaf_block:
1490 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1492 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1496 BUG_ON(path == NULL);
1497 depth = path->p_depth;
1499 /* zero-tree has no leaf blocks at all */
1501 return EXT_MAX_BLOCKS;
1503 /* go to index block */
1506 while (depth >= 0) {
1507 if (path[depth].p_idx !=
1508 EXT_LAST_INDEX(path[depth].p_hdr))
1509 return (ext4_lblk_t)
1510 le32_to_cpu(path[depth].p_idx[1].ei_block);
1514 return EXT_MAX_BLOCKS;
1518 * ext4_ext_correct_indexes:
1519 * if leaf gets modified and modified extent is first in the leaf,
1520 * then we have to correct all indexes above.
1521 * TODO: do we need to correct tree in all cases?
1523 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1524 struct ext4_ext_path *path)
1526 struct ext4_extent_header *eh;
1527 int depth = ext_depth(inode);
1528 struct ext4_extent *ex;
1532 eh = path[depth].p_hdr;
1533 ex = path[depth].p_ext;
1535 if (unlikely(ex == NULL || eh == NULL)) {
1536 EXT4_ERROR_INODE(inode,
1537 "ex %p == NULL or eh %p == NULL", ex, eh);
1542 /* there is no tree at all */
1546 if (ex != EXT_FIRST_EXTENT(eh)) {
1547 /* we correct tree if first leaf got modified only */
1552 * TODO: we need correction if border is smaller than current one
1555 border = path[depth].p_ext->ee_block;
1556 err = ext4_ext_get_access(handle, inode, path + k);
1559 path[k].p_idx->ei_block = border;
1560 err = ext4_ext_dirty(handle, inode, path + k);
1565 /* change all left-side indexes */
1566 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1568 err = ext4_ext_get_access(handle, inode, path + k);
1571 path[k].p_idx->ei_block = border;
1572 err = ext4_ext_dirty(handle, inode, path + k);
1581 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1582 struct ext4_extent *ex2)
1584 unsigned short ext1_ee_len, ext2_ee_len, max_len;
1587 * Make sure that either both extents are uninitialized, or
1590 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1593 if (ext4_ext_is_uninitialized(ex1))
1594 max_len = EXT_UNINIT_MAX_LEN;
1596 max_len = EXT_INIT_MAX_LEN;
1598 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1599 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1601 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1602 le32_to_cpu(ex2->ee_block))
1606 * To allow future support for preallocated extents to be added
1607 * as an RO_COMPAT feature, refuse to merge to extents if
1608 * this can result in the top bit of ee_len being set.
1610 if (ext1_ee_len + ext2_ee_len > max_len)
1612 #ifdef AGGRESSIVE_TEST
1613 if (ext1_ee_len >= 4)
1617 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1623 * This function tries to merge the "ex" extent to the next extent in the tree.
1624 * It always tries to merge towards right. If you want to merge towards
1625 * left, pass "ex - 1" as argument instead of "ex".
1626 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1627 * 1 if they got merged.
1629 static int ext4_ext_try_to_merge_right(struct inode *inode,
1630 struct ext4_ext_path *path,
1631 struct ext4_extent *ex)
1633 struct ext4_extent_header *eh;
1634 unsigned int depth, len;
1636 int uninitialized = 0;
1638 depth = ext_depth(inode);
1639 BUG_ON(path[depth].p_hdr == NULL);
1640 eh = path[depth].p_hdr;
1642 while (ex < EXT_LAST_EXTENT(eh)) {
1643 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1645 /* merge with next extent! */
1646 if (ext4_ext_is_uninitialized(ex))
1648 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1649 + ext4_ext_get_actual_len(ex + 1));
1651 ext4_ext_mark_uninitialized(ex);
1653 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1654 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1655 * sizeof(struct ext4_extent);
1656 memmove(ex + 1, ex + 2, len);
1658 le16_add_cpu(&eh->eh_entries, -1);
1660 WARN_ON(eh->eh_entries == 0);
1661 if (!eh->eh_entries)
1662 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1669 * This function does a very simple check to see if we can collapse
1670 * an extent tree with a single extent tree leaf block into the inode.
1672 static void ext4_ext_try_to_merge_up(handle_t *handle,
1673 struct inode *inode,
1674 struct ext4_ext_path *path)
1677 unsigned max_root = ext4_ext_space_root(inode, 0);
1680 if ((path[0].p_depth != 1) ||
1681 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1682 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1686 * We need to modify the block allocation bitmap and the block
1687 * group descriptor to release the extent tree block. If we
1688 * can't get the journal credits, give up.
1690 if (ext4_journal_extend(handle, 2))
1694 * Copy the extent data up to the inode
1696 blk = ext4_idx_pblock(path[0].p_idx);
1697 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1698 sizeof(struct ext4_extent_idx);
1699 s += sizeof(struct ext4_extent_header);
1701 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1702 path[0].p_depth = 0;
1703 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1704 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1705 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1707 brelse(path[1].p_bh);
1708 ext4_free_blocks(handle, inode, NULL, blk, 1,
1709 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1713 * This function tries to merge the @ex extent to neighbours in the tree.
1714 * return 1 if merge left else 0.
1716 static void ext4_ext_try_to_merge(handle_t *handle,
1717 struct inode *inode,
1718 struct ext4_ext_path *path,
1719 struct ext4_extent *ex) {
1720 struct ext4_extent_header *eh;
1724 depth = ext_depth(inode);
1725 BUG_ON(path[depth].p_hdr == NULL);
1726 eh = path[depth].p_hdr;
1728 if (ex > EXT_FIRST_EXTENT(eh))
1729 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1732 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1734 ext4_ext_try_to_merge_up(handle, inode, path);
1738 * check if a portion of the "newext" extent overlaps with an
1741 * If there is an overlap discovered, it updates the length of the newext
1742 * such that there will be no overlap, and then returns 1.
1743 * If there is no overlap found, it returns 0.
1745 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1746 struct inode *inode,
1747 struct ext4_extent *newext,
1748 struct ext4_ext_path *path)
1751 unsigned int depth, len1;
1752 unsigned int ret = 0;
1754 b1 = le32_to_cpu(newext->ee_block);
1755 len1 = ext4_ext_get_actual_len(newext);
1756 depth = ext_depth(inode);
1757 if (!path[depth].p_ext)
1759 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1760 b2 &= ~(sbi->s_cluster_ratio - 1);
1763 * get the next allocated block if the extent in the path
1764 * is before the requested block(s)
1767 b2 = ext4_ext_next_allocated_block(path);
1768 if (b2 == EXT_MAX_BLOCKS)
1770 b2 &= ~(sbi->s_cluster_ratio - 1);
1773 /* check for wrap through zero on extent logical start block*/
1774 if (b1 + len1 < b1) {
1775 len1 = EXT_MAX_BLOCKS - b1;
1776 newext->ee_len = cpu_to_le16(len1);
1780 /* check for overlap */
1781 if (b1 + len1 > b2) {
1782 newext->ee_len = cpu_to_le16(b2 - b1);
1790 * ext4_ext_insert_extent:
1791 * tries to merge requsted extent into the existing extent or
1792 * inserts requested extent as new one into the tree,
1793 * creating new leaf in the no-space case.
1795 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1796 struct ext4_ext_path *path,
1797 struct ext4_extent *newext, int flag)
1799 struct ext4_extent_header *eh;
1800 struct ext4_extent *ex, *fex;
1801 struct ext4_extent *nearex; /* nearest extent */
1802 struct ext4_ext_path *npath = NULL;
1803 int depth, len, err;
1805 unsigned uninitialized = 0;
1808 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1809 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1812 depth = ext_depth(inode);
1813 ex = path[depth].p_ext;
1814 if (unlikely(path[depth].p_hdr == NULL)) {
1815 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1819 /* try to insert block into found extent and return */
1820 if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
1821 && ext4_can_extents_be_merged(inode, ex, newext)) {
1822 ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n",
1823 ext4_ext_is_uninitialized(newext),
1824 ext4_ext_get_actual_len(newext),
1825 le32_to_cpu(ex->ee_block),
1826 ext4_ext_is_uninitialized(ex),
1827 ext4_ext_get_actual_len(ex),
1828 ext4_ext_pblock(ex));
1829 err = ext4_ext_get_access(handle, inode, path + depth);
1834 * ext4_can_extents_be_merged should have checked that either
1835 * both extents are uninitialized, or both aren't. Thus we
1836 * need to check only one of them here.
1838 if (ext4_ext_is_uninitialized(ex))
1840 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1841 + ext4_ext_get_actual_len(newext));
1843 ext4_ext_mark_uninitialized(ex);
1844 eh = path[depth].p_hdr;
1849 depth = ext_depth(inode);
1850 eh = path[depth].p_hdr;
1851 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1854 /* probably next leaf has space for us? */
1855 fex = EXT_LAST_EXTENT(eh);
1856 next = EXT_MAX_BLOCKS;
1857 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
1858 next = ext4_ext_next_leaf_block(path);
1859 if (next != EXT_MAX_BLOCKS) {
1860 ext_debug("next leaf block - %u\n", next);
1861 BUG_ON(npath != NULL);
1862 npath = ext4_ext_find_extent(inode, next, NULL);
1864 return PTR_ERR(npath);
1865 BUG_ON(npath->p_depth != path->p_depth);
1866 eh = npath[depth].p_hdr;
1867 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1868 ext_debug("next leaf isn't full(%d)\n",
1869 le16_to_cpu(eh->eh_entries));
1873 ext_debug("next leaf has no free space(%d,%d)\n",
1874 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1878 * There is no free space in the found leaf.
1879 * We're gonna add a new leaf in the tree.
1881 if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
1882 flags = EXT4_MB_USE_ROOT_BLOCKS;
1883 err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
1886 depth = ext_depth(inode);
1887 eh = path[depth].p_hdr;
1890 nearex = path[depth].p_ext;
1892 err = ext4_ext_get_access(handle, inode, path + depth);
1897 /* there is no extent in this leaf, create first one */
1898 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
1899 le32_to_cpu(newext->ee_block),
1900 ext4_ext_pblock(newext),
1901 ext4_ext_is_uninitialized(newext),
1902 ext4_ext_get_actual_len(newext));
1903 nearex = EXT_FIRST_EXTENT(eh);
1905 if (le32_to_cpu(newext->ee_block)
1906 > le32_to_cpu(nearex->ee_block)) {
1908 ext_debug("insert %u:%llu:[%d]%d before: "
1910 le32_to_cpu(newext->ee_block),
1911 ext4_ext_pblock(newext),
1912 ext4_ext_is_uninitialized(newext),
1913 ext4_ext_get_actual_len(newext),
1918 BUG_ON(newext->ee_block == nearex->ee_block);
1919 ext_debug("insert %u:%llu:[%d]%d after: "
1921 le32_to_cpu(newext->ee_block),
1922 ext4_ext_pblock(newext),
1923 ext4_ext_is_uninitialized(newext),
1924 ext4_ext_get_actual_len(newext),
1927 len = EXT_LAST_EXTENT(eh) - nearex + 1;
1929 ext_debug("insert %u:%llu:[%d]%d: "
1930 "move %d extents from 0x%p to 0x%p\n",
1931 le32_to_cpu(newext->ee_block),
1932 ext4_ext_pblock(newext),
1933 ext4_ext_is_uninitialized(newext),
1934 ext4_ext_get_actual_len(newext),
1935 len, nearex, nearex + 1);
1936 memmove(nearex + 1, nearex,
1937 len * sizeof(struct ext4_extent));
1941 le16_add_cpu(&eh->eh_entries, 1);
1942 path[depth].p_ext = nearex;
1943 nearex->ee_block = newext->ee_block;
1944 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
1945 nearex->ee_len = newext->ee_len;
1948 /* try to merge extents */
1949 if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
1950 ext4_ext_try_to_merge(handle, inode, path, nearex);
1953 /* time to correct all indexes above */
1954 err = ext4_ext_correct_indexes(handle, inode, path);
1958 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
1962 ext4_ext_drop_refs(npath);
1968 static int ext4_fill_fiemap_extents(struct inode *inode,
1969 ext4_lblk_t block, ext4_lblk_t num,
1970 struct fiemap_extent_info *fieinfo)
1972 struct ext4_ext_path *path = NULL;
1973 struct ext4_extent *ex;
1974 struct extent_status es;
1975 ext4_lblk_t next, next_del, start = 0, end = 0;
1976 ext4_lblk_t last = block + num;
1977 int exists, depth = 0, err = 0;
1978 unsigned int flags = 0;
1979 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
1981 while (block < last && block != EXT_MAX_BLOCKS) {
1983 /* find extent for this block */
1984 down_read(&EXT4_I(inode)->i_data_sem);
1986 if (path && ext_depth(inode) != depth) {
1987 /* depth was changed. we have to realloc path */
1992 path = ext4_ext_find_extent(inode, block, path);
1994 up_read(&EXT4_I(inode)->i_data_sem);
1995 err = PTR_ERR(path);
2000 depth = ext_depth(inode);
2001 if (unlikely(path[depth].p_hdr == NULL)) {
2002 up_read(&EXT4_I(inode)->i_data_sem);
2003 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2007 ex = path[depth].p_ext;
2008 next = ext4_ext_next_allocated_block(path);
2009 ext4_ext_drop_refs(path);
2014 /* there is no extent yet, so try to allocate
2015 * all requested space */
2018 } else if (le32_to_cpu(ex->ee_block) > block) {
2019 /* need to allocate space before found extent */
2021 end = le32_to_cpu(ex->ee_block);
2022 if (block + num < end)
2024 } else if (block >= le32_to_cpu(ex->ee_block)
2025 + ext4_ext_get_actual_len(ex)) {
2026 /* need to allocate space after found extent */
2031 } else if (block >= le32_to_cpu(ex->ee_block)) {
2033 * some part of requested space is covered
2037 end = le32_to_cpu(ex->ee_block)
2038 + ext4_ext_get_actual_len(ex);
2039 if (block + num < end)
2045 BUG_ON(end <= start);
2049 es.es_len = end - start;
2052 es.es_lblk = le32_to_cpu(ex->ee_block);
2053 es.es_len = ext4_ext_get_actual_len(ex);
2054 es.es_pblk = ext4_ext_pblock(ex);
2055 if (ext4_ext_is_uninitialized(ex))
2056 flags |= FIEMAP_EXTENT_UNWRITTEN;
2060 * Find delayed extent and update es accordingly. We call
2061 * it even in !exists case to find out whether es is the
2062 * last existing extent or not.
2064 next_del = ext4_find_delayed_extent(inode, &es);
2065 if (!exists && next_del) {
2067 flags |= FIEMAP_EXTENT_DELALLOC;
2069 up_read(&EXT4_I(inode)->i_data_sem);
2071 if (unlikely(es.es_len == 0)) {
2072 EXT4_ERROR_INODE(inode, "es.es_len == 0");
2078 * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2079 * we need to check next == EXT_MAX_BLOCKS because it is
2080 * possible that an extent is with unwritten and delayed
2081 * status due to when an extent is delayed allocated and
2082 * is allocated by fallocate status tree will track both of
2085 * So we could return a unwritten and delayed extent, and
2086 * its block is equal to 'next'.
2088 if (next == next_del && next == EXT_MAX_BLOCKS) {
2089 flags |= FIEMAP_EXTENT_LAST;
2090 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2091 next != EXT_MAX_BLOCKS)) {
2092 EXT4_ERROR_INODE(inode,
2093 "next extent == %u, next "
2094 "delalloc extent = %u",
2102 err = fiemap_fill_next_extent(fieinfo,
2103 (__u64)es.es_lblk << blksize_bits,
2104 (__u64)es.es_pblk << blksize_bits,
2105 (__u64)es.es_len << blksize_bits,
2115 block = es.es_lblk + es.es_len;
2119 ext4_ext_drop_refs(path);
2127 * ext4_ext_put_gap_in_cache:
2128 * calculate boundaries of the gap that the requested block fits into
2129 * and cache this gap
2132 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2135 int depth = ext_depth(inode);
2138 struct ext4_extent *ex;
2140 ex = path[depth].p_ext;
2143 * there is no extent yet, so gap is [0;-] and we
2146 ext_debug("cache gap(whole file):");
2147 } else if (block < le32_to_cpu(ex->ee_block)) {
2149 len = le32_to_cpu(ex->ee_block) - block;
2150 ext_debug("cache gap(before): %u [%u:%u]",
2152 le32_to_cpu(ex->ee_block),
2153 ext4_ext_get_actual_len(ex));
2154 if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1))
2155 ext4_es_insert_extent(inode, lblock, len, ~0,
2156 EXTENT_STATUS_HOLE);
2157 } else if (block >= le32_to_cpu(ex->ee_block)
2158 + ext4_ext_get_actual_len(ex)) {
2160 lblock = le32_to_cpu(ex->ee_block)
2161 + ext4_ext_get_actual_len(ex);
2163 next = ext4_ext_next_allocated_block(path);
2164 ext_debug("cache gap(after): [%u:%u] %u",
2165 le32_to_cpu(ex->ee_block),
2166 ext4_ext_get_actual_len(ex),
2168 BUG_ON(next == lblock);
2169 len = next - lblock;
2170 if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1))
2171 ext4_es_insert_extent(inode, lblock, len, ~0,
2172 EXTENT_STATUS_HOLE);
2178 ext_debug(" -> %u:%lu\n", lblock, len);
2183 * removes index from the index block.
2185 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2186 struct ext4_ext_path *path, int depth)
2191 /* free index block */
2193 path = path + depth;
2194 leaf = ext4_idx_pblock(path->p_idx);
2195 if (unlikely(path->p_hdr->eh_entries == 0)) {
2196 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2199 err = ext4_ext_get_access(handle, inode, path);
2203 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2204 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2205 len *= sizeof(struct ext4_extent_idx);
2206 memmove(path->p_idx, path->p_idx + 1, len);
2209 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2210 err = ext4_ext_dirty(handle, inode, path);
2213 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2214 trace_ext4_ext_rm_idx(inode, leaf);
2216 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2217 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2219 while (--depth >= 0) {
2220 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2223 err = ext4_ext_get_access(handle, inode, path);
2226 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2227 err = ext4_ext_dirty(handle, inode, path);
2235 * ext4_ext_calc_credits_for_single_extent:
2236 * This routine returns max. credits that needed to insert an extent
2237 * to the extent tree.
2238 * When pass the actual path, the caller should calculate credits
2241 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2242 struct ext4_ext_path *path)
2245 int depth = ext_depth(inode);
2248 /* probably there is space in leaf? */
2249 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2250 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2253 * There are some space in the leaf tree, no
2254 * need to account for leaf block credit
2256 * bitmaps and block group descriptor blocks
2257 * and other metadata blocks still need to be
2260 /* 1 bitmap, 1 block group descriptor */
2261 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2266 return ext4_chunk_trans_blocks(inode, nrblocks);
2270 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2272 * if nrblocks are fit in a single extent (chunk flag is 1), then
2273 * in the worse case, each tree level index/leaf need to be changed
2274 * if the tree split due to insert a new extent, then the old tree
2275 * index/leaf need to be updated too
2277 * If the nrblocks are discontiguous, they could cause
2278 * the whole tree split more than once, but this is really rare.
2280 int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
2285 /* If we are converting the inline data, only one is needed here. */
2286 if (ext4_has_inline_data(inode))
2289 depth = ext_depth(inode);
2299 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2300 struct ext4_extent *ex,
2301 ext4_fsblk_t *partial_cluster,
2302 ext4_lblk_t from, ext4_lblk_t to)
2304 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2305 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2309 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2310 flags |= EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2311 else if (ext4_should_journal_data(inode))
2312 flags |= EXT4_FREE_BLOCKS_FORGET;
2315 * For bigalloc file systems, we never free a partial cluster
2316 * at the beginning of the extent. Instead, we make a note
2317 * that we tried freeing the cluster, and check to see if we
2318 * need to free it on a subsequent call to ext4_remove_blocks,
2319 * or at the end of the ext4_truncate() operation.
2321 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2323 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2325 * If we have a partial cluster, and it's different from the
2326 * cluster of the last block, we need to explicitly free the
2327 * partial cluster here.
2329 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2330 if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
2331 ext4_free_blocks(handle, inode, NULL,
2332 EXT4_C2B(sbi, *partial_cluster),
2333 sbi->s_cluster_ratio, flags);
2334 *partial_cluster = 0;
2337 #ifdef EXTENTS_STATS
2339 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2340 spin_lock(&sbi->s_ext_stats_lock);
2341 sbi->s_ext_blocks += ee_len;
2342 sbi->s_ext_extents++;
2343 if (ee_len < sbi->s_ext_min)
2344 sbi->s_ext_min = ee_len;
2345 if (ee_len > sbi->s_ext_max)
2346 sbi->s_ext_max = ee_len;
2347 if (ext_depth(inode) > sbi->s_depth_max)
2348 sbi->s_depth_max = ext_depth(inode);
2349 spin_unlock(&sbi->s_ext_stats_lock);
2352 if (from >= le32_to_cpu(ex->ee_block)
2353 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2357 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2358 pblk = ext4_ext_pblock(ex) + ee_len - num;
2359 ext_debug("free last %u blocks starting %llu\n", num, pblk);
2360 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2362 * If the block range to be freed didn't start at the
2363 * beginning of a cluster, and we removed the entire
2364 * extent, save the partial cluster here, since we
2365 * might need to delete if we determine that the
2366 * truncate operation has removed all of the blocks in
2369 if (pblk & (sbi->s_cluster_ratio - 1) &&
2371 *partial_cluster = EXT4_B2C(sbi, pblk);
2373 *partial_cluster = 0;
2374 } else if (from == le32_to_cpu(ex->ee_block)
2375 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
2381 start = ext4_ext_pblock(ex);
2383 ext_debug("free first %u blocks starting %llu\n", num, start);
2384 ext4_free_blocks(handle, inode, NULL, start, num, flags);
2387 printk(KERN_INFO "strange request: removal(2) "
2388 "%u-%u from %u:%u\n",
2389 from, to, le32_to_cpu(ex->ee_block), ee_len);
2396 * ext4_ext_rm_leaf() Removes the extents associated with the
2397 * blocks appearing between "start" and "end", and splits the extents
2398 * if "start" and "end" appear in the same extent
2400 * @handle: The journal handle
2401 * @inode: The files inode
2402 * @path: The path to the leaf
2403 * @start: The first block to remove
2404 * @end: The last block to remove
2407 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2408 struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster,
2409 ext4_lblk_t start, ext4_lblk_t end)
2411 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2412 int err = 0, correct_index = 0;
2413 int depth = ext_depth(inode), credits;
2414 struct ext4_extent_header *eh;
2417 ext4_lblk_t ex_ee_block;
2418 unsigned short ex_ee_len;
2419 unsigned uninitialized = 0;
2420 struct ext4_extent *ex;
2422 /* the header must be checked already in ext4_ext_remove_space() */
2423 ext_debug("truncate since %u in leaf to %u\n", start, end);
2424 if (!path[depth].p_hdr)
2425 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2426 eh = path[depth].p_hdr;
2427 if (unlikely(path[depth].p_hdr == NULL)) {
2428 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2431 /* find where to start removing */
2432 ex = EXT_LAST_EXTENT(eh);
2434 ex_ee_block = le32_to_cpu(ex->ee_block);
2435 ex_ee_len = ext4_ext_get_actual_len(ex);
2437 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2439 while (ex >= EXT_FIRST_EXTENT(eh) &&
2440 ex_ee_block + ex_ee_len > start) {
2442 if (ext4_ext_is_uninitialized(ex))
2447 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2448 uninitialized, ex_ee_len);
2449 path[depth].p_ext = ex;
2451 a = ex_ee_block > start ? ex_ee_block : start;
2452 b = ex_ee_block+ex_ee_len - 1 < end ?
2453 ex_ee_block+ex_ee_len - 1 : end;
2455 ext_debug(" border %u:%u\n", a, b);
2457 /* If this extent is beyond the end of the hole, skip it */
2458 if (end < ex_ee_block) {
2460 ex_ee_block = le32_to_cpu(ex->ee_block);
2461 ex_ee_len = ext4_ext_get_actual_len(ex);
2463 } else if (b != ex_ee_block + ex_ee_len - 1) {
2464 EXT4_ERROR_INODE(inode,
2465 "can not handle truncate %u:%u "
2467 start, end, ex_ee_block,
2468 ex_ee_block + ex_ee_len - 1);
2471 } else if (a != ex_ee_block) {
2472 /* remove tail of the extent */
2473 num = a - ex_ee_block;
2475 /* remove whole extent: excellent! */
2479 * 3 for leaf, sb, and inode plus 2 (bmap and group
2480 * descriptor) for each block group; assume two block
2481 * groups plus ex_ee_len/blocks_per_block_group for
2484 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2485 if (ex == EXT_FIRST_EXTENT(eh)) {
2487 credits += (ext_depth(inode)) + 1;
2489 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2491 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2495 err = ext4_ext_get_access(handle, inode, path + depth);
2499 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2505 /* this extent is removed; mark slot entirely unused */
2506 ext4_ext_store_pblock(ex, 0);
2508 ex->ee_len = cpu_to_le16(num);
2510 * Do not mark uninitialized if all the blocks in the
2511 * extent have been removed.
2513 if (uninitialized && num)
2514 ext4_ext_mark_uninitialized(ex);
2516 * If the extent was completely released,
2517 * we need to remove it from the leaf
2520 if (end != EXT_MAX_BLOCKS - 1) {
2522 * For hole punching, we need to scoot all the
2523 * extents up when an extent is removed so that
2524 * we dont have blank extents in the middle
2526 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2527 sizeof(struct ext4_extent));
2529 /* Now get rid of the one at the end */
2530 memset(EXT_LAST_EXTENT(eh), 0,
2531 sizeof(struct ext4_extent));
2533 le16_add_cpu(&eh->eh_entries, -1);
2535 *partial_cluster = 0;
2537 err = ext4_ext_dirty(handle, inode, path + depth);
2541 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2542 ext4_ext_pblock(ex));
2544 ex_ee_block = le32_to_cpu(ex->ee_block);
2545 ex_ee_len = ext4_ext_get_actual_len(ex);
2548 if (correct_index && eh->eh_entries)
2549 err = ext4_ext_correct_indexes(handle, inode, path);
2552 * If there is still a entry in the leaf node, check to see if
2553 * it references the partial cluster. This is the only place
2554 * where it could; if it doesn't, we can free the cluster.
2556 if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) &&
2557 (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
2558 *partial_cluster)) {
2559 int flags = EXT4_FREE_BLOCKS_FORGET;
2561 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2562 flags |= EXT4_FREE_BLOCKS_METADATA;
2564 ext4_free_blocks(handle, inode, NULL,
2565 EXT4_C2B(sbi, *partial_cluster),
2566 sbi->s_cluster_ratio, flags);
2567 *partial_cluster = 0;
2570 /* if this leaf is free, then we should
2571 * remove it from index block above */
2572 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2573 err = ext4_ext_rm_idx(handle, inode, path, depth);
2580 * ext4_ext_more_to_rm:
2581 * returns 1 if current index has to be freed (even partial)
2584 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2586 BUG_ON(path->p_idx == NULL);
2588 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2592 * if truncate on deeper level happened, it wasn't partial,
2593 * so we have to consider current index for truncation
2595 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2600 static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2603 struct super_block *sb = inode->i_sb;
2604 int depth = ext_depth(inode);
2605 struct ext4_ext_path *path = NULL;
2606 ext4_fsblk_t partial_cluster = 0;
2610 ext_debug("truncate since %u to %u\n", start, end);
2612 /* probably first extent we're gonna free will be last in block */
2613 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2615 return PTR_ERR(handle);
2618 trace_ext4_ext_remove_space(inode, start, depth);
2621 * Check if we are removing extents inside the extent tree. If that
2622 * is the case, we are going to punch a hole inside the extent tree
2623 * so we have to check whether we need to split the extent covering
2624 * the last block to remove so we can easily remove the part of it
2625 * in ext4_ext_rm_leaf().
2627 if (end < EXT_MAX_BLOCKS - 1) {
2628 struct ext4_extent *ex;
2629 ext4_lblk_t ee_block;
2631 /* find extent for this block */
2632 path = ext4_ext_find_extent(inode, end, NULL);
2634 ext4_journal_stop(handle);
2635 return PTR_ERR(path);
2637 depth = ext_depth(inode);
2638 /* Leaf not may not exist only if inode has no blocks at all */
2639 ex = path[depth].p_ext;
2642 EXT4_ERROR_INODE(inode,
2643 "path[%d].p_hdr == NULL",
2650 ee_block = le32_to_cpu(ex->ee_block);
2653 * See if the last block is inside the extent, if so split
2654 * the extent at 'end' block so we can easily remove the
2655 * tail of the first part of the split extent in
2656 * ext4_ext_rm_leaf().
2658 if (end >= ee_block &&
2659 end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
2662 if (ext4_ext_is_uninitialized(ex))
2663 split_flag = EXT4_EXT_MARK_UNINIT1 |
2664 EXT4_EXT_MARK_UNINIT2;
2667 * Split the extent in two so that 'end' is the last
2668 * block in the first new extent
2670 err = ext4_split_extent_at(handle, inode, path,
2671 end + 1, split_flag,
2672 EXT4_GET_BLOCKS_PRE_IO |
2673 EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
2680 * We start scanning from right side, freeing all the blocks
2681 * after i_size and walking into the tree depth-wise.
2683 depth = ext_depth(inode);
2688 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2690 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2693 ext4_journal_stop(handle);
2696 path[0].p_depth = depth;
2697 path[0].p_hdr = ext_inode_hdr(inode);
2700 if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
2707 while (i >= 0 && err == 0) {
2709 /* this is leaf block */
2710 err = ext4_ext_rm_leaf(handle, inode, path,
2711 &partial_cluster, start,
2713 /* root level has p_bh == NULL, brelse() eats this */
2714 brelse(path[i].p_bh);
2715 path[i].p_bh = NULL;
2720 /* this is index block */
2721 if (!path[i].p_hdr) {
2722 ext_debug("initialize header\n");
2723 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2726 if (!path[i].p_idx) {
2727 /* this level hasn't been touched yet */
2728 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2729 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2730 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2732 le16_to_cpu(path[i].p_hdr->eh_entries));
2734 /* we were already here, see at next index */
2738 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2739 i, EXT_FIRST_INDEX(path[i].p_hdr),
2741 if (ext4_ext_more_to_rm(path + i)) {
2742 struct buffer_head *bh;
2743 /* go to the next level */
2744 ext_debug("move to level %d (block %llu)\n",
2745 i + 1, ext4_idx_pblock(path[i].p_idx));
2746 memset(path + i + 1, 0, sizeof(*path));
2747 bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
2749 /* should we reset i_size? */
2753 if (WARN_ON(i + 1 > depth)) {
2757 if (ext4_ext_check_block(inode, ext_block_hdr(bh),
2758 depth - i - 1, bh)) {
2762 path[i + 1].p_bh = bh;
2764 /* save actual number of indexes since this
2765 * number is changed at the next iteration */
2766 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2769 /* we finished processing this index, go up */
2770 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2771 /* index is empty, remove it;
2772 * handle must be already prepared by the
2773 * truncatei_leaf() */
2774 err = ext4_ext_rm_idx(handle, inode, path, i);
2776 /* root level has p_bh == NULL, brelse() eats this */
2777 brelse(path[i].p_bh);
2778 path[i].p_bh = NULL;
2780 ext_debug("return to level %d\n", i);
2784 trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster,
2785 path->p_hdr->eh_entries);
2787 /* If we still have something in the partial cluster and we have removed
2788 * even the first extent, then we should free the blocks in the partial
2789 * cluster as well. */
2790 if (partial_cluster && path->p_hdr->eh_entries == 0) {
2791 int flags = EXT4_FREE_BLOCKS_FORGET;
2793 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2794 flags |= EXT4_FREE_BLOCKS_METADATA;
2796 ext4_free_blocks(handle, inode, NULL,
2797 EXT4_C2B(EXT4_SB(sb), partial_cluster),
2798 EXT4_SB(sb)->s_cluster_ratio, flags);
2799 partial_cluster = 0;
2802 /* TODO: flexible tree reduction should be here */
2803 if (path->p_hdr->eh_entries == 0) {
2805 * truncate to zero freed all the tree,
2806 * so we need to correct eh_depth
2808 err = ext4_ext_get_access(handle, inode, path);
2810 ext_inode_hdr(inode)->eh_depth = 0;
2811 ext_inode_hdr(inode)->eh_max =
2812 cpu_to_le16(ext4_ext_space_root(inode, 0));
2813 err = ext4_ext_dirty(handle, inode, path);
2817 ext4_ext_drop_refs(path);
2819 if (err == -EAGAIN) {
2823 ext4_journal_stop(handle);
2829 * called at mount time
2831 void ext4_ext_init(struct super_block *sb)
2834 * possible initialization would be here
2837 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2838 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2839 printk(KERN_INFO "EXT4-fs: file extents enabled"
2840 #ifdef AGGRESSIVE_TEST
2841 ", aggressive tests"
2843 #ifdef CHECK_BINSEARCH
2846 #ifdef EXTENTS_STATS
2851 #ifdef EXTENTS_STATS
2852 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2853 EXT4_SB(sb)->s_ext_min = 1 << 30;
2854 EXT4_SB(sb)->s_ext_max = 0;
2860 * called at umount time
2862 void ext4_ext_release(struct super_block *sb)
2864 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
2867 #ifdef EXTENTS_STATS
2868 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2869 struct ext4_sb_info *sbi = EXT4_SB(sb);
2870 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2871 sbi->s_ext_blocks, sbi->s_ext_extents,
2872 sbi->s_ext_blocks / sbi->s_ext_extents);
2873 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2874 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2879 /* FIXME!! we need to try to merge to left or right after zero-out */
2880 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2882 ext4_fsblk_t ee_pblock;
2883 unsigned int ee_len;
2886 ee_len = ext4_ext_get_actual_len(ex);
2887 ee_pblock = ext4_ext_pblock(ex);
2889 ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
2897 * ext4_split_extent_at() splits an extent at given block.
2899 * @handle: the journal handle
2900 * @inode: the file inode
2901 * @path: the path to the extent
2902 * @split: the logical block where the extent is splitted.
2903 * @split_flags: indicates if the extent could be zeroout if split fails, and
2904 * the states(init or uninit) of new extents.
2905 * @flags: flags used to insert new extent to extent tree.
2908 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
2909 * of which are deterimined by split_flag.
2911 * There are two cases:
2912 * a> the extent are splitted into two extent.
2913 * b> split is not needed, and just mark the extent.
2915 * return 0 on success.
2917 static int ext4_split_extent_at(handle_t *handle,
2918 struct inode *inode,
2919 struct ext4_ext_path *path,
2924 ext4_fsblk_t newblock;
2925 ext4_lblk_t ee_block;
2926 struct ext4_extent *ex, newex, orig_ex;
2927 struct ext4_extent *ex2 = NULL;
2928 unsigned int ee_len, depth;
2931 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
2932 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
2934 ext_debug("ext4_split_extents_at: inode %lu, logical"
2935 "block %llu\n", inode->i_ino, (unsigned long long)split);
2937 ext4_ext_show_leaf(inode, path);
2939 depth = ext_depth(inode);
2940 ex = path[depth].p_ext;
2941 ee_block = le32_to_cpu(ex->ee_block);
2942 ee_len = ext4_ext_get_actual_len(ex);
2943 newblock = split - ee_block + ext4_ext_pblock(ex);
2945 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
2947 err = ext4_ext_get_access(handle, inode, path + depth);
2951 if (split == ee_block) {
2953 * case b: block @split is the block that the extent begins with
2954 * then we just change the state of the extent, and splitting
2957 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2958 ext4_ext_mark_uninitialized(ex);
2960 ext4_ext_mark_initialized(ex);
2962 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
2963 ext4_ext_try_to_merge(handle, inode, path, ex);
2965 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2970 memcpy(&orig_ex, ex, sizeof(orig_ex));
2971 ex->ee_len = cpu_to_le16(split - ee_block);
2972 if (split_flag & EXT4_EXT_MARK_UNINIT1)
2973 ext4_ext_mark_uninitialized(ex);
2976 * path may lead to new leaf, not to original leaf any more
2977 * after ext4_ext_insert_extent() returns,
2979 err = ext4_ext_dirty(handle, inode, path + depth);
2981 goto fix_extent_len;
2984 ex2->ee_block = cpu_to_le32(split);
2985 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
2986 ext4_ext_store_pblock(ex2, newblock);
2987 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2988 ext4_ext_mark_uninitialized(ex2);
2990 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
2991 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
2992 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
2993 if (split_flag & EXT4_EXT_DATA_VALID1)
2994 err = ext4_ext_zeroout(inode, ex2);
2996 err = ext4_ext_zeroout(inode, ex);
2998 err = ext4_ext_zeroout(inode, &orig_ex);
3001 goto fix_extent_len;
3002 /* update the extent length and mark as initialized */
3003 ex->ee_len = cpu_to_le16(ee_len);
3004 ext4_ext_try_to_merge(handle, inode, path, ex);
3005 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3008 goto fix_extent_len;
3011 ext4_ext_show_leaf(inode, path);
3015 ex->ee_len = orig_ex.ee_len;
3016 ext4_ext_dirty(handle, inode, path + depth);
3021 * ext4_split_extents() splits an extent and mark extent which is covered
3022 * by @map as split_flags indicates
3024 * It may result in splitting the extent into multiple extents (upto three)
3025 * There are three possibilities:
3026 * a> There is no split required
3027 * b> Splits in two extents: Split is happening at either end of the extent
3028 * c> Splits in three extents: Somone is splitting in middle of the extent
3031 static int ext4_split_extent(handle_t *handle,
3032 struct inode *inode,
3033 struct ext4_ext_path *path,
3034 struct ext4_map_blocks *map,
3038 ext4_lblk_t ee_block;
3039 struct ext4_extent *ex;
3040 unsigned int ee_len, depth;
3043 int split_flag1, flags1;
3045 depth = ext_depth(inode);
3046 ex = path[depth].p_ext;
3047 ee_block = le32_to_cpu(ex->ee_block);
3048 ee_len = ext4_ext_get_actual_len(ex);
3049 uninitialized = ext4_ext_is_uninitialized(ex);
3051 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3052 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3053 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3055 split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
3056 EXT4_EXT_MARK_UNINIT2;
3057 if (split_flag & EXT4_EXT_DATA_VALID2)
3058 split_flag1 |= EXT4_EXT_DATA_VALID1;
3059 err = ext4_split_extent_at(handle, inode, path,
3060 map->m_lblk + map->m_len, split_flag1, flags1);
3065 ext4_ext_drop_refs(path);
3066 path = ext4_ext_find_extent(inode, map->m_lblk, path);
3068 return PTR_ERR(path);
3070 if (map->m_lblk >= ee_block) {
3071 split_flag1 = split_flag & (EXT4_EXT_MAY_ZEROOUT |
3072 EXT4_EXT_DATA_VALID2);
3074 split_flag1 |= EXT4_EXT_MARK_UNINIT1;
3075 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3076 split_flag1 |= EXT4_EXT_MARK_UNINIT2;
3077 err = ext4_split_extent_at(handle, inode, path,
3078 map->m_lblk, split_flag1, flags);
3083 ext4_ext_show_leaf(inode, path);
3085 return err ? err : map->m_len;
3089 * This function is called by ext4_ext_map_blocks() if someone tries to write
3090 * to an uninitialized extent. It may result in splitting the uninitialized
3091 * extent into multiple extents (up to three - one initialized and two
3093 * There are three possibilities:
3094 * a> There is no split required: Entire extent should be initialized
3095 * b> Splits in two extents: Write is happening at either end of the extent
3096 * c> Splits in three extents: Somone is writing in middle of the extent
3099 * - The extent pointed to by 'path' is uninitialized.
3100 * - The extent pointed to by 'path' contains a superset
3101 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3103 * Post-conditions on success:
3104 * - the returned value is the number of blocks beyond map->l_lblk
3105 * that are allocated and initialized.
3106 * It is guaranteed to be >= map->m_len.
3108 static int ext4_ext_convert_to_initialized(handle_t *handle,
3109 struct inode *inode,
3110 struct ext4_map_blocks *map,
3111 struct ext4_ext_path *path)
3113 struct ext4_sb_info *sbi;
3114 struct ext4_extent_header *eh;
3115 struct ext4_map_blocks split_map;
3116 struct ext4_extent zero_ex;
3117 struct ext4_extent *ex;
3118 ext4_lblk_t ee_block, eof_block;
3119 unsigned int ee_len, depth;
3120 int allocated, max_zeroout = 0;
3124 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3125 "block %llu, max_blocks %u\n", inode->i_ino,
3126 (unsigned long long)map->m_lblk, map->m_len);
3128 sbi = EXT4_SB(inode->i_sb);
3129 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3130 inode->i_sb->s_blocksize_bits;
3131 if (eof_block < map->m_lblk + map->m_len)
3132 eof_block = map->m_lblk + map->m_len;
3134 depth = ext_depth(inode);
3135 eh = path[depth].p_hdr;
3136 ex = path[depth].p_ext;
3137 ee_block = le32_to_cpu(ex->ee_block);
3138 ee_len = ext4_ext_get_actual_len(ex);
3139 allocated = ee_len - (map->m_lblk - ee_block);
3141 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3143 /* Pre-conditions */
3144 BUG_ON(!ext4_ext_is_uninitialized(ex));
3145 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3148 * Attempt to transfer newly initialized blocks from the currently
3149 * uninitialized extent to its left neighbor. This is much cheaper
3150 * than an insertion followed by a merge as those involve costly
3151 * memmove() calls. This is the common case in steady state for
3152 * workloads doing fallocate(FALLOC_FL_KEEP_SIZE) followed by append
3155 * Limitations of the current logic:
3156 * - L1: we only deal with writes at the start of the extent.
3157 * The approach could be extended to writes at the end
3158 * of the extent but this scenario was deemed less common.
3159 * - L2: we do not deal with writes covering the whole extent.
3160 * This would require removing the extent if the transfer
3162 * - L3: we only attempt to merge with an extent stored in the
3163 * same extent tree node.
3165 if ((map->m_lblk == ee_block) && /*L1*/
3166 (map->m_len < ee_len) && /*L2*/
3167 (ex > EXT_FIRST_EXTENT(eh))) { /*L3*/
3168 struct ext4_extent *prev_ex;
3169 ext4_lblk_t prev_lblk;
3170 ext4_fsblk_t prev_pblk, ee_pblk;
3171 unsigned int prev_len, write_len;
3174 prev_lblk = le32_to_cpu(prev_ex->ee_block);
3175 prev_len = ext4_ext_get_actual_len(prev_ex);
3176 prev_pblk = ext4_ext_pblock(prev_ex);
3177 ee_pblk = ext4_ext_pblock(ex);
3178 write_len = map->m_len;
3181 * A transfer of blocks from 'ex' to 'prev_ex' is allowed
3182 * upon those conditions:
3183 * - C1: prev_ex is initialized,
3184 * - C2: prev_ex is logically abutting ex,
3185 * - C3: prev_ex is physically abutting ex,
3186 * - C4: prev_ex can receive the additional blocks without
3187 * overflowing the (initialized) length limit.
3189 if ((!ext4_ext_is_uninitialized(prev_ex)) && /*C1*/
3190 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3191 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3192 (prev_len < (EXT_INIT_MAX_LEN - write_len))) { /*C4*/
3193 err = ext4_ext_get_access(handle, inode, path + depth);
3197 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3200 /* Shift the start of ex by 'write_len' blocks */
3201 ex->ee_block = cpu_to_le32(ee_block + write_len);
3202 ext4_ext_store_pblock(ex, ee_pblk + write_len);
3203 ex->ee_len = cpu_to_le16(ee_len - write_len);
3204 ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3206 /* Extend prev_ex by 'write_len' blocks */
3207 prev_ex->ee_len = cpu_to_le16(prev_len + write_len);
3209 /* Mark the block containing both extents as dirty */
3210 ext4_ext_dirty(handle, inode, path + depth);
3212 /* Update path to point to the right extent */
3213 path[depth].p_ext = prev_ex;
3215 /* Result: number of initialized blocks past m_lblk */
3216 allocated = write_len;
3221 WARN_ON(map->m_lblk < ee_block);
3223 * It is safe to convert extent to initialized via explicit
3224 * zeroout only if extent is fully insde i_size or new_size.
3226 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3228 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3229 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3230 inode->i_sb->s_blocksize_bits;
3232 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3233 if (max_zeroout && (ee_len <= max_zeroout)) {
3234 err = ext4_ext_zeroout(inode, ex);
3238 err = ext4_ext_get_access(handle, inode, path + depth);
3241 ext4_ext_mark_initialized(ex);
3242 ext4_ext_try_to_merge(handle, inode, path, ex);
3243 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3249 * 1. split the extent into three extents.
3250 * 2. split the extent into two extents, zeroout the first half.
3251 * 3. split the extent into two extents, zeroout the second half.
3252 * 4. split the extent into two extents with out zeroout.
3254 split_map.m_lblk = map->m_lblk;
3255 split_map.m_len = map->m_len;
3257 if (max_zeroout && (allocated > map->m_len)) {
3258 if (allocated <= max_zeroout) {
3261 cpu_to_le32(map->m_lblk);
3262 zero_ex.ee_len = cpu_to_le16(allocated);
3263 ext4_ext_store_pblock(&zero_ex,
3264 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3265 err = ext4_ext_zeroout(inode, &zero_ex);
3268 split_map.m_lblk = map->m_lblk;
3269 split_map.m_len = allocated;
3270 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3272 if (map->m_lblk != ee_block) {
3273 zero_ex.ee_block = ex->ee_block;
3274 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3276 ext4_ext_store_pblock(&zero_ex,
3277 ext4_ext_pblock(ex));
3278 err = ext4_ext_zeroout(inode, &zero_ex);
3283 split_map.m_lblk = ee_block;
3284 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3285 allocated = map->m_len;
3289 allocated = ext4_split_extent(handle, inode, path,
3290 &split_map, split_flag, 0);
3295 return err ? err : allocated;
3299 * This function is called by ext4_ext_map_blocks() from
3300 * ext4_get_blocks_dio_write() when DIO to write
3301 * to an uninitialized extent.
3303 * Writing to an uninitialized extent may result in splitting the uninitialized
3304 * extent into multiple initialized/uninitialized extents (up to three)
3305 * There are three possibilities:
3306 * a> There is no split required: Entire extent should be uninitialized
3307 * b> Splits in two extents: Write is happening at either end of the extent
3308 * c> Splits in three extents: Somone is writing in middle of the extent
3310 * One of more index blocks maybe needed if the extent tree grow after
3311 * the uninitialized extent split. To prevent ENOSPC occur at the IO
3312 * complete, we need to split the uninitialized extent before DIO submit
3313 * the IO. The uninitialized extent called at this time will be split
3314 * into three uninitialized extent(at most). After IO complete, the part
3315 * being filled will be convert to initialized by the end_io callback function
3316 * via ext4_convert_unwritten_extents().
3318 * Returns the size of uninitialized extent to be written on success.
3320 static int ext4_split_unwritten_extents(handle_t *handle,
3321 struct inode *inode,
3322 struct ext4_map_blocks *map,
3323 struct ext4_ext_path *path,
3326 ext4_lblk_t eof_block;
3327 ext4_lblk_t ee_block;
3328 struct ext4_extent *ex;
3329 unsigned int ee_len;
3330 int split_flag = 0, depth;
3332 ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3333 "block %llu, max_blocks %u\n", inode->i_ino,
3334 (unsigned long long)map->m_lblk, map->m_len);
3336 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3337 inode->i_sb->s_blocksize_bits;
3338 if (eof_block < map->m_lblk + map->m_len)
3339 eof_block = map->m_lblk + map->m_len;
3341 * It is safe to convert extent to initialized via explicit
3342 * zeroout only if extent is fully insde i_size or new_size.
3344 depth = ext_depth(inode);
3345 ex = path[depth].p_ext;
3346 ee_block = le32_to_cpu(ex->ee_block);
3347 ee_len = ext4_ext_get_actual_len(ex);
3349 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3350 split_flag |= EXT4_EXT_MARK_UNINIT2;
3351 if (flags & EXT4_GET_BLOCKS_CONVERT)
3352 split_flag |= EXT4_EXT_DATA_VALID2;
3353 flags |= EXT4_GET_BLOCKS_PRE_IO;
3354 return ext4_split_extent(handle, inode, path, map, split_flag, flags);
3357 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3358 struct inode *inode,
3359 struct ext4_map_blocks *map,
3360 struct ext4_ext_path *path)
3362 struct ext4_extent *ex;
3363 ext4_lblk_t ee_block;
3364 unsigned int ee_len;
3368 depth = ext_depth(inode);
3369 ex = path[depth].p_ext;
3370 ee_block = le32_to_cpu(ex->ee_block);
3371 ee_len = ext4_ext_get_actual_len(ex);
3373 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3374 "block %llu, max_blocks %u\n", inode->i_ino,
3375 (unsigned long long)ee_block, ee_len);
3377 /* If extent is larger than requested then split is required */
3378 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3379 err = ext4_split_unwritten_extents(handle, inode, map, path,
3380 EXT4_GET_BLOCKS_CONVERT);
3383 ext4_ext_drop_refs(path);
3384 path = ext4_ext_find_extent(inode, map->m_lblk, path);
3386 err = PTR_ERR(path);
3389 depth = ext_depth(inode);
3390 ex = path[depth].p_ext;
3393 err = ext4_ext_get_access(handle, inode, path + depth);
3396 /* first mark the extent as initialized */
3397 ext4_ext_mark_initialized(ex);
3399 /* note: ext4_ext_correct_indexes() isn't needed here because
3400 * borders are not changed
3402 ext4_ext_try_to_merge(handle, inode, path, ex);
3404 /* Mark modified extent as dirty */
3405 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3407 ext4_ext_show_leaf(inode, path);
3411 static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3412 sector_t block, int count)
3415 for (i = 0; i < count; i++)
3416 unmap_underlying_metadata(bdev, block + i);
3420 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3422 static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3424 struct ext4_ext_path *path,
3428 struct ext4_extent_header *eh;
3429 struct ext4_extent *last_ex;
3431 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3434 depth = ext_depth(inode);
3435 eh = path[depth].p_hdr;
3438 * We're going to remove EOFBLOCKS_FL entirely in future so we
3439 * do not care for this case anymore. Simply remove the flag
3440 * if there are no extents.
3442 if (unlikely(!eh->eh_entries))
3444 last_ex = EXT_LAST_EXTENT(eh);
3446 * We should clear the EOFBLOCKS_FL flag if we are writing the
3447 * last block in the last extent in the file. We test this by
3448 * first checking to see if the caller to
3449 * ext4_ext_get_blocks() was interested in the last block (or
3450 * a block beyond the last block) in the current extent. If
3451 * this turns out to be false, we can bail out from this
3452 * function immediately.
3454 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3455 ext4_ext_get_actual_len(last_ex))
3458 * If the caller does appear to be planning to write at or
3459 * beyond the end of the current extent, we then test to see
3460 * if the current extent is the last extent in the file, by
3461 * checking to make sure it was reached via the rightmost node
3462 * at each level of the tree.
3464 for (i = depth-1; i >= 0; i--)
3465 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3468 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3469 return ext4_mark_inode_dirty(handle, inode);
3473 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3475 * Return 1 if there is a delalloc block in the range, otherwise 0.
3477 int ext4_find_delalloc_range(struct inode *inode,
3478 ext4_lblk_t lblk_start,
3479 ext4_lblk_t lblk_end)
3481 struct extent_status es;
3483 ext4_es_find_delayed_extent(inode, lblk_start, &es);
3485 return 0; /* there is no delay extent in this tree */
3486 else if (es.es_lblk <= lblk_start &&
3487 lblk_start < es.es_lblk + es.es_len)
3489 else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3495 int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3497 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3498 ext4_lblk_t lblk_start, lblk_end;
3499 lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
3500 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3502 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3506 * Determines how many complete clusters (out of those specified by the 'map')
3507 * are under delalloc and were reserved quota for.
3508 * This function is called when we are writing out the blocks that were
3509 * originally written with their allocation delayed, but then the space was
3510 * allocated using fallocate() before the delayed allocation could be resolved.
3511 * The cases to look for are:
3512 * ('=' indicated delayed allocated blocks
3513 * '-' indicates non-delayed allocated blocks)
3514 * (a) partial clusters towards beginning and/or end outside of allocated range
3515 * are not delalloc'ed.
3517 * |----c---=|====c====|====c====|===-c----|
3518 * |++++++ allocated ++++++|
3519 * ==> 4 complete clusters in above example
3521 * (b) partial cluster (outside of allocated range) towards either end is
3522 * marked for delayed allocation. In this case, we will exclude that
3525 * |----====c========|========c========|
3526 * |++++++ allocated ++++++|
3527 * ==> 1 complete clusters in above example
3530 * |================c================|
3531 * |++++++ allocated ++++++|
3532 * ==> 0 complete clusters in above example
3534 * The ext4_da_update_reserve_space will be called only if we
3535 * determine here that there were some "entire" clusters that span
3536 * this 'allocated' range.
3537 * In the non-bigalloc case, this function will just end up returning num_blks
3538 * without ever calling ext4_find_delalloc_range.
3541 get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3542 unsigned int num_blks)
3544 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3545 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3546 ext4_lblk_t lblk_from, lblk_to, c_offset;
3547 unsigned int allocated_clusters = 0;
3549 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3550 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3552 /* max possible clusters for this allocation */
3553 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3555 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3557 /* Check towards left side */
3558 c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
3560 lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
3561 lblk_to = lblk_from + c_offset - 1;
3563 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3564 allocated_clusters--;
3567 /* Now check towards right. */
3568 c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
3569 if (allocated_clusters && c_offset) {
3570 lblk_from = lblk_start + num_blks;
3571 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3573 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3574 allocated_clusters--;
3577 return allocated_clusters;
3581 ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3582 struct ext4_map_blocks *map,
3583 struct ext4_ext_path *path, int flags,
3584 unsigned int allocated, ext4_fsblk_t newblock)
3588 ext4_io_end_t *io = ext4_inode_aio(inode);
3590 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
3591 "block %llu, max_blocks %u, flags %x, allocated %u\n",
3592 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
3594 ext4_ext_show_leaf(inode, path);
3596 trace_ext4_ext_handle_uninitialized_extents(inode, map, flags,
3597 allocated, newblock);
3599 /* get_block() before submit the IO, split the extent */
3600 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3601 ret = ext4_split_unwritten_extents(handle, inode, map,
3606 * Flag the inode(non aio case) or end_io struct (aio case)
3607 * that this IO needs to conversion to written when IO is
3611 ext4_set_io_unwritten_flag(inode, io);
3613 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3614 map->m_flags |= EXT4_MAP_UNWRITTEN;
3615 if (ext4_should_dioread_nolock(inode))
3616 map->m_flags |= EXT4_MAP_UNINIT;
3619 /* IO end_io complete, convert the filled extent to written */
3620 if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
3621 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
3624 ext4_update_inode_fsync_trans(handle, inode, 1);
3625 err = check_eofblocks_fl(handle, inode, map->m_lblk,
3631 /* buffered IO case */
3633 * repeat fallocate creation request
3634 * we already have an unwritten extent
3636 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) {
3637 map->m_flags |= EXT4_MAP_UNWRITTEN;
3641 /* buffered READ or buffered write_begin() lookup */
3642 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3644 * We have blocks reserved already. We
3645 * return allocated blocks so that delalloc
3646 * won't do block reservation for us. But
3647 * the buffer head will be unmapped so that
3648 * a read from the block returns 0s.
3650 map->m_flags |= EXT4_MAP_UNWRITTEN;
3654 /* buffered write, writepage time, convert*/
3655 ret = ext4_ext_convert_to_initialized(handle, inode, map, path);
3657 ext4_update_inode_fsync_trans(handle, inode, 1);
3664 map->m_flags |= EXT4_MAP_NEW;
3666 * if we allocated more blocks than requested
3667 * we need to make sure we unmap the extra block
3668 * allocated. The actual needed block will get
3669 * unmapped later when we find the buffer_head marked
3672 if (allocated > map->m_len) {
3673 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
3674 newblock + map->m_len,
3675 allocated - map->m_len);
3676 allocated = map->m_len;
3680 * If we have done fallocate with the offset that is already
3681 * delayed allocated, we would have block reservation
3682 * and quota reservation done in the delayed write path.
3683 * But fallocate would have already updated quota and block
3684 * count for this offset. So cancel these reservation
3686 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
3687 unsigned int reserved_clusters;
3688 reserved_clusters = get_reserved_cluster_alloc(inode,
3689 map->m_lblk, map->m_len);
3690 if (reserved_clusters)
3691 ext4_da_update_reserve_space(inode,
3697 map->m_flags |= EXT4_MAP_MAPPED;
3698 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
3699 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
3705 if (allocated > map->m_len)
3706 allocated = map->m_len;
3707 ext4_ext_show_leaf(inode, path);
3708 map->m_pblk = newblock;
3709 map->m_len = allocated;
3712 ext4_ext_drop_refs(path);
3715 return err ? err : allocated;
3719 * get_implied_cluster_alloc - check to see if the requested
3720 * allocation (in the map structure) overlaps with a cluster already
3721 * allocated in an extent.
3722 * @sb The filesystem superblock structure
3723 * @map The requested lblk->pblk mapping
3724 * @ex The extent structure which might contain an implied
3725 * cluster allocation
3727 * This function is called by ext4_ext_map_blocks() after we failed to
3728 * find blocks that were already in the inode's extent tree. Hence,
3729 * we know that the beginning of the requested region cannot overlap
3730 * the extent from the inode's extent tree. There are three cases we
3731 * want to catch. The first is this case:
3733 * |--- cluster # N--|
3734 * |--- extent ---| |---- requested region ---|
3737 * The second case that we need to test for is this one:
3739 * |--------- cluster # N ----------------|
3740 * |--- requested region --| |------- extent ----|
3741 * |=======================|
3743 * The third case is when the requested region lies between two extents
3744 * within the same cluster:
3745 * |------------- cluster # N-------------|
3746 * |----- ex -----| |---- ex_right ----|
3747 * |------ requested region ------|
3748 * |================|
3750 * In each of the above cases, we need to set the map->m_pblk and
3751 * map->m_len so it corresponds to the return the extent labelled as
3752 * "|====|" from cluster #N, since it is already in use for data in
3753 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
3754 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
3755 * as a new "allocated" block region. Otherwise, we will return 0 and
3756 * ext4_ext_map_blocks() will then allocate one or more new clusters
3757 * by calling ext4_mb_new_blocks().
3759 static int get_implied_cluster_alloc(struct super_block *sb,
3760 struct ext4_map_blocks *map,
3761 struct ext4_extent *ex,
3762 struct ext4_ext_path *path)
3764 struct ext4_sb_info *sbi = EXT4_SB(sb);
3765 ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3766 ext4_lblk_t ex_cluster_start, ex_cluster_end;
3767 ext4_lblk_t rr_cluster_start;
3768 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3769 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3770 unsigned short ee_len = ext4_ext_get_actual_len(ex);
3772 /* The extent passed in that we are trying to match */
3773 ex_cluster_start = EXT4_B2C(sbi, ee_block);
3774 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
3776 /* The requested region passed into ext4_map_blocks() */
3777 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
3779 if ((rr_cluster_start == ex_cluster_end) ||
3780 (rr_cluster_start == ex_cluster_start)) {
3781 if (rr_cluster_start == ex_cluster_end)
3782 ee_start += ee_len - 1;
3783 map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) +
3785 map->m_len = min(map->m_len,
3786 (unsigned) sbi->s_cluster_ratio - c_offset);
3788 * Check for and handle this case:
3790 * |--------- cluster # N-------------|
3791 * |------- extent ----|
3792 * |--- requested region ---|
3796 if (map->m_lblk < ee_block)
3797 map->m_len = min(map->m_len, ee_block - map->m_lblk);
3800 * Check for the case where there is already another allocated
3801 * block to the right of 'ex' but before the end of the cluster.
3803 * |------------- cluster # N-------------|
3804 * |----- ex -----| |---- ex_right ----|
3805 * |------ requested region ------|
3806 * |================|
3808 if (map->m_lblk > ee_block) {
3809 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
3810 map->m_len = min(map->m_len, next - map->m_lblk);
3813 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
3817 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
3823 * Block allocation/map/preallocation routine for extents based files
3826 * Need to be called with
3827 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
3828 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
3830 * return > 0, number of of blocks already mapped/allocated
3831 * if create == 0 and these are pre-allocated blocks
3832 * buffer head is unmapped
3833 * otherwise blocks are mapped
3835 * return = 0, if plain look up failed (blocks have not been allocated)
3836 * buffer head is unmapped
3838 * return < 0, error case.
3840 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3841 struct ext4_map_blocks *map, int flags)
3843 struct ext4_ext_path *path = NULL;
3844 struct ext4_extent newex, *ex, *ex2;
3845 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3846 ext4_fsblk_t newblock = 0;
3847 int free_on_err = 0, err = 0, depth;
3848 unsigned int allocated = 0, offset = 0;
3849 unsigned int allocated_clusters = 0;
3850 struct ext4_allocation_request ar;
3851 ext4_io_end_t *io = ext4_inode_aio(inode);
3852 ext4_lblk_t cluster_offset;
3853 int set_unwritten = 0;
3855 ext_debug("blocks %u/%u requested for inode %lu\n",
3856 map->m_lblk, map->m_len, inode->i_ino);
3857 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
3859 /* find extent for this block */
3860 path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
3862 err = PTR_ERR(path);
3867 depth = ext_depth(inode);
3870 * consistent leaf must not be empty;
3871 * this situation is possible, though, _during_ tree modification;
3872 * this is why assert can't be put in ext4_ext_find_extent()
3874 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
3875 EXT4_ERROR_INODE(inode, "bad extent address "
3876 "lblock: %lu, depth: %d pblock %lld",
3877 (unsigned long) map->m_lblk, depth,
3878 path[depth].p_block);
3883 ex = path[depth].p_ext;
3885 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3886 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3887 unsigned short ee_len;
3890 * Uninitialized extents are treated as holes, except that
3891 * we split out initialized portions during a write.
3893 ee_len = ext4_ext_get_actual_len(ex);
3895 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
3897 /* if found extent covers block, simply return it */
3898 if (in_range(map->m_lblk, ee_block, ee_len)) {
3899 newblock = map->m_lblk - ee_block + ee_start;
3900 /* number of remaining blocks in the extent */
3901 allocated = ee_len - (map->m_lblk - ee_block);
3902 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
3903 ee_block, ee_len, newblock);
3905 if (!ext4_ext_is_uninitialized(ex))
3908 allocated = ext4_ext_handle_uninitialized_extents(
3909 handle, inode, map, path, flags,
3910 allocated, newblock);
3915 if ((sbi->s_cluster_ratio > 1) &&
3916 ext4_find_delalloc_cluster(inode, map->m_lblk))
3917 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3920 * requested block isn't allocated yet;
3921 * we couldn't try to create block if create flag is zero
3923 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3925 * put just found gap into cache to speed up
3926 * subsequent requests
3928 if ((flags & EXT4_GET_BLOCKS_NO_PUT_HOLE) == 0)
3929 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
3934 * Okay, we need to do block allocation.
3936 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
3937 newex.ee_block = cpu_to_le32(map->m_lblk);
3938 cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3941 * If we are doing bigalloc, check to see if the extent returned
3942 * by ext4_ext_find_extent() implies a cluster we can use.
3944 if (cluster_offset && ex &&
3945 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
3946 ar.len = allocated = map->m_len;
3947 newblock = map->m_pblk;
3948 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3949 goto got_allocated_blocks;
3952 /* find neighbour allocated blocks */
3953 ar.lleft = map->m_lblk;
3954 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
3957 ar.lright = map->m_lblk;
3959 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
3963 /* Check if the extent after searching to the right implies a
3964 * cluster we can use. */
3965 if ((sbi->s_cluster_ratio > 1) && ex2 &&
3966 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
3967 ar.len = allocated = map->m_len;
3968 newblock = map->m_pblk;
3969 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3970 goto got_allocated_blocks;
3974 * See if request is beyond maximum number of blocks we can have in
3975 * a single extent. For an initialized extent this limit is
3976 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
3977 * EXT_UNINIT_MAX_LEN.
3979 if (map->m_len > EXT_INIT_MAX_LEN &&
3980 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
3981 map->m_len = EXT_INIT_MAX_LEN;
3982 else if (map->m_len > EXT_UNINIT_MAX_LEN &&
3983 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
3984 map->m_len = EXT_UNINIT_MAX_LEN;
3986 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
3987 newex.ee_len = cpu_to_le16(map->m_len);
3988 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
3990 allocated = ext4_ext_get_actual_len(&newex);
3992 allocated = map->m_len;
3994 /* allocate new block */
3996 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
3997 ar.logical = map->m_lblk;
3999 * We calculate the offset from the beginning of the cluster
4000 * for the logical block number, since when we allocate a
4001 * physical cluster, the physical block should start at the
4002 * same offset from the beginning of the cluster. This is
4003 * needed so that future calls to get_implied_cluster_alloc()
4006 offset = map->m_lblk & (sbi->s_cluster_ratio - 1);
4007 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4009 ar.logical -= offset;
4010 if (S_ISREG(inode->i_mode))
4011 ar.flags = EXT4_MB_HINT_DATA;
4013 /* disable in-core preallocation for non-regular files */
4015 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4016 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4017 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4020 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4021 ar.goal, newblock, allocated);
4023 allocated_clusters = ar.len;
4024 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4025 if (ar.len > allocated)
4028 got_allocated_blocks:
4029 /* try to insert new extent into found leaf and return */
4030 ext4_ext_store_pblock(&newex, newblock + offset);
4031 newex.ee_len = cpu_to_le16(ar.len);
4032 /* Mark uninitialized */
4033 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
4034 ext4_ext_mark_uninitialized(&newex);
4035 map->m_flags |= EXT4_MAP_UNWRITTEN;
4037 * io_end structure was created for every IO write to an
4038 * uninitialized extent. To avoid unnecessary conversion,
4039 * here we flag the IO that really needs the conversion.
4040 * For non asycn direct IO case, flag the inode state
4041 * that we need to perform conversion when IO is done.
4043 if ((flags & EXT4_GET_BLOCKS_PRE_IO))
4045 if (ext4_should_dioread_nolock(inode))
4046 map->m_flags |= EXT4_MAP_UNINIT;
4050 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4051 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4054 err = ext4_ext_insert_extent(handle, inode, path,
4057 if (!err && set_unwritten) {
4059 ext4_set_io_unwritten_flag(inode, io);
4061 ext4_set_inode_state(inode,
4062 EXT4_STATE_DIO_UNWRITTEN);
4065 if (err && free_on_err) {
4066 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4067 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4068 /* free data blocks we just allocated */
4069 /* not a good idea to call discard here directly,
4070 * but otherwise we'd need to call it every free() */
4071 ext4_discard_preallocations(inode);
4072 ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex),
4073 ext4_ext_get_actual_len(&newex), fb_flags);
4077 /* previous routine could use block we allocated */
4078 newblock = ext4_ext_pblock(&newex);
4079 allocated = ext4_ext_get_actual_len(&newex);
4080 if (allocated > map->m_len)
4081 allocated = map->m_len;
4082 map->m_flags |= EXT4_MAP_NEW;
4085 * Update reserved blocks/metadata blocks after successful
4086 * block allocation which had been deferred till now.
4088 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4089 unsigned int reserved_clusters;
4091 * Check how many clusters we had reserved this allocated range
4093 reserved_clusters = get_reserved_cluster_alloc(inode,
4094 map->m_lblk, allocated);
4095 if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
4096 if (reserved_clusters) {
4098 * We have clusters reserved for this range.
4099 * But since we are not doing actual allocation
4100 * and are simply using blocks from previously
4101 * allocated cluster, we should release the
4102 * reservation and not claim quota.
4104 ext4_da_update_reserve_space(inode,
4105 reserved_clusters, 0);
4108 BUG_ON(allocated_clusters < reserved_clusters);
4109 /* We will claim quota for all newly allocated blocks.*/
4110 ext4_da_update_reserve_space(inode, allocated_clusters,
4112 if (reserved_clusters < allocated_clusters) {
4113 struct ext4_inode_info *ei = EXT4_I(inode);
4114 int reservation = allocated_clusters -
4117 * It seems we claimed few clusters outside of
4118 * the range of this allocation. We should give
4119 * it back to the reservation pool. This can
4120 * happen in the following case:
4122 * * Suppose s_cluster_ratio is 4 (i.e., each
4123 * cluster has 4 blocks. Thus, the clusters
4124 * are [0-3],[4-7],[8-11]...
4125 * * First comes delayed allocation write for
4126 * logical blocks 10 & 11. Since there were no
4127 * previous delayed allocated blocks in the
4128 * range [8-11], we would reserve 1 cluster
4130 * * Next comes write for logical blocks 3 to 8.
4131 * In this case, we will reserve 2 clusters
4132 * (for [0-3] and [4-7]; and not for [8-11] as
4133 * that range has a delayed allocated blocks.
4134 * Thus total reserved clusters now becomes 3.
4135 * * Now, during the delayed allocation writeout
4136 * time, we will first write blocks [3-8] and
4137 * allocate 3 clusters for writing these
4138 * blocks. Also, we would claim all these
4139 * three clusters above.
4140 * * Now when we come here to writeout the
4141 * blocks [10-11], we would expect to claim
4142 * the reservation of 1 cluster we had made
4143 * (and we would claim it since there are no
4144 * more delayed allocated blocks in the range
4145 * [8-11]. But our reserved cluster count had
4146 * already gone to 0.
4148 * Thus, at the step 4 above when we determine
4149 * that there are still some unwritten delayed
4150 * allocated blocks outside of our current
4151 * block range, we should increment the
4152 * reserved clusters count so that when the
4153 * remaining blocks finally gets written, we
4156 dquot_reserve_block(inode,
4157 EXT4_C2B(sbi, reservation));
4158 spin_lock(&ei->i_block_reservation_lock);
4159 ei->i_reserved_data_blocks += reservation;
4160 spin_unlock(&ei->i_block_reservation_lock);
4166 * Cache the extent and update transaction to commit on fdatasync only
4167 * when it is _not_ an uninitialized extent.
4169 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
4170 ext4_update_inode_fsync_trans(handle, inode, 1);
4172 ext4_update_inode_fsync_trans(handle, inode, 0);
4174 if (allocated > map->m_len)
4175 allocated = map->m_len;
4176 ext4_ext_show_leaf(inode, path);
4177 map->m_flags |= EXT4_MAP_MAPPED;
4178 map->m_pblk = newblock;
4179 map->m_len = allocated;
4182 ext4_ext_drop_refs(path);
4187 trace_ext4_ext_map_blocks_exit(inode, map, err ? err : allocated);
4189 return err ? err : allocated;
4192 void ext4_ext_truncate(struct inode *inode)
4194 struct address_space *mapping = inode->i_mapping;
4195 struct super_block *sb = inode->i_sb;
4196 ext4_lblk_t last_block;
4202 * finish any pending end_io work so we won't run the risk of
4203 * converting any truncated blocks to initialized later
4205 ext4_flush_unwritten_io(inode);
4208 * probably first extent we're gonna free will be last in block
4210 err = ext4_writepage_trans_blocks(inode);
4211 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, err);
4215 if (inode->i_size % PAGE_CACHE_SIZE != 0) {
4216 page_len = PAGE_CACHE_SIZE -
4217 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4219 err = ext4_discard_partial_page_buffers(handle,
4220 mapping, inode->i_size, page_len, 0);
4226 if (ext4_orphan_add(handle, inode))
4229 down_write(&EXT4_I(inode)->i_data_sem);
4231 ext4_discard_preallocations(inode);
4234 * TODO: optimization is possible here.
4235 * Probably we need not scan at all,
4236 * because page truncation is enough.
4239 /* we have to know where to truncate from in crash case */
4240 EXT4_I(inode)->i_disksize = inode->i_size;
4241 ext4_mark_inode_dirty(handle, inode);
4243 last_block = (inode->i_size + sb->s_blocksize - 1)
4244 >> EXT4_BLOCK_SIZE_BITS(sb);
4245 err = ext4_es_remove_extent(inode, last_block,
4246 EXT_MAX_BLOCKS - last_block);
4247 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4249 /* In a multi-transaction truncate, we only make the final
4250 * transaction synchronous.
4253 ext4_handle_sync(handle);
4255 up_write(&EXT4_I(inode)->i_data_sem);
4259 * If this was a simple ftruncate() and the file will remain alive,
4260 * then we need to clear up the orphan record which we created above.
4261 * However, if this was a real unlink then we were called by
4262 * ext4_delete_inode(), and we allow that function to clean up the
4263 * orphan info for us.
4266 ext4_orphan_del(handle, inode);
4268 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4269 ext4_mark_inode_dirty(handle, inode);
4270 ext4_journal_stop(handle);
4273 static void ext4_falloc_update_inode(struct inode *inode,
4274 int mode, loff_t new_size, int update_ctime)
4276 struct timespec now;
4279 now = current_fs_time(inode->i_sb);
4280 if (!timespec_equal(&inode->i_ctime, &now))
4281 inode->i_ctime = now;
4284 * Update only when preallocation was requested beyond
4287 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
4288 if (new_size > i_size_read(inode))
4289 i_size_write(inode, new_size);
4290 if (new_size > EXT4_I(inode)->i_disksize)
4291 ext4_update_i_disksize(inode, new_size);
4294 * Mark that we allocate beyond EOF so the subsequent truncate
4295 * can proceed even if the new size is the same as i_size.
4297 if (new_size > i_size_read(inode))
4298 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4304 * preallocate space for a file. This implements ext4's fallocate file
4305 * operation, which gets called from sys_fallocate system call.
4306 * For block-mapped files, posix_fallocate should fall back to the method
4307 * of writing zeroes to the required new blocks (the same behavior which is
4308 * expected for file systems which do not support fallocate() system call).
4310 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4312 struct inode *inode = file_inode(file);
4315 unsigned int max_blocks;
4320 struct ext4_map_blocks map;
4321 unsigned int credits, blkbits = inode->i_blkbits;
4323 /* Return error if mode is not supported */
4324 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
4327 if (mode & FALLOC_FL_PUNCH_HOLE)
4328 return ext4_punch_hole(file, offset, len);
4330 ret = ext4_convert_inline_data(inode);
4335 * currently supporting (pre)allocate mode for extent-based
4338 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4341 trace_ext4_fallocate_enter(inode, offset, len, mode);
4342 map.m_lblk = offset >> blkbits;
4344 * We can't just convert len to max_blocks because
4345 * If blocksize = 4096 offset = 3072 and len = 2048
4347 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4350 * credits to insert 1 extent into extent tree
4352 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4353 mutex_lock(&inode->i_mutex);
4354 ret = inode_newsize_ok(inode, (len + offset));
4356 mutex_unlock(&inode->i_mutex);
4357 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4360 flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
4361 if (mode & FALLOC_FL_KEEP_SIZE)
4362 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4364 * Don't normalize the request if it can fit in one extent so
4365 * that it doesn't get unnecessarily split into multiple
4368 if (len <= EXT_UNINIT_MAX_LEN << blkbits)
4369 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4371 /* Prevent race condition between unwritten */
4372 ext4_flush_unwritten_io(inode);
4374 while (ret >= 0 && ret < max_blocks) {
4375 map.m_lblk = map.m_lblk + ret;
4376 map.m_len = max_blocks = max_blocks - ret;
4377 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4379 if (IS_ERR(handle)) {
4380 ret = PTR_ERR(handle);
4383 ret = ext4_map_blocks(handle, inode, &map, flags);
4386 ext4_warning(inode->i_sb,
4387 "inode #%lu: block %u: len %u: "
4388 "ext4_ext_map_blocks returned %d",
4389 inode->i_ino, map.m_lblk,
4392 ext4_mark_inode_dirty(handle, inode);
4393 ret2 = ext4_journal_stop(handle);
4396 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
4397 blkbits) >> blkbits))
4398 new_size = offset + len;
4400 new_size = ((loff_t) map.m_lblk + ret) << blkbits;
4402 ext4_falloc_update_inode(inode, mode, new_size,
4403 (map.m_flags & EXT4_MAP_NEW));
4404 ext4_mark_inode_dirty(handle, inode);
4405 if ((file->f_flags & O_SYNC) && ret >= max_blocks)
4406 ext4_handle_sync(handle);
4407 ret2 = ext4_journal_stop(handle);
4411 if (ret == -ENOSPC &&
4412 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4416 mutex_unlock(&inode->i_mutex);
4417 trace_ext4_fallocate_exit(inode, offset, max_blocks,
4418 ret > 0 ? ret2 : ret);
4419 return ret > 0 ? ret2 : ret;
4423 * This function convert a range of blocks to written extents
4424 * The caller of this function will pass the start offset and the size.
4425 * all unwritten extents within this range will be converted to
4428 * This function is called from the direct IO end io call back
4429 * function, to convert the fallocated extents after IO is completed.
4430 * Returns 0 on success.
4432 int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
4436 unsigned int max_blocks;
4439 struct ext4_map_blocks map;
4440 unsigned int credits, blkbits = inode->i_blkbits;
4442 map.m_lblk = offset >> blkbits;
4444 * We can't just convert len to max_blocks because
4445 * If blocksize = 4096 offset = 3072 and len = 2048
4447 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
4450 * credits to insert 1 extent into extent tree
4452 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4453 while (ret >= 0 && ret < max_blocks) {
4455 map.m_len = (max_blocks -= ret);
4456 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, credits);
4457 if (IS_ERR(handle)) {
4458 ret = PTR_ERR(handle);
4461 ret = ext4_map_blocks(handle, inode, &map,
4462 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4464 ext4_warning(inode->i_sb,
4465 "inode #%lu: block %u: len %u: "
4466 "ext4_ext_map_blocks returned %d",
4467 inode->i_ino, map.m_lblk,
4469 ext4_mark_inode_dirty(handle, inode);
4470 ret2 = ext4_journal_stop(handle);
4471 if (ret <= 0 || ret2 )
4474 return ret > 0 ? ret2 : ret;
4478 * If newes is not existing extent (newes->ec_pblk equals zero) find
4479 * delayed extent at start of newes and update newes accordingly and
4480 * return start of the next delayed extent.
4482 * If newes is existing extent (newes->ec_pblk is not equal zero)
4483 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
4484 * extent found. Leave newes unmodified.
4486 static int ext4_find_delayed_extent(struct inode *inode,
4487 struct extent_status *newes)
4489 struct extent_status es;
4490 ext4_lblk_t block, next_del;
4492 ext4_es_find_delayed_extent(inode, newes->es_lblk, &es);
4494 if (newes->es_pblk == 0) {
4496 * No extent in extent-tree contains block @newes->es_pblk,
4497 * then the block may stay in 1)a hole or 2)delayed-extent.
4503 if (es.es_lblk > newes->es_lblk) {
4505 newes->es_len = min(es.es_lblk - newes->es_lblk,
4510 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
4513 block = newes->es_lblk + newes->es_len;
4514 ext4_es_find_delayed_extent(inode, block, &es);
4516 next_del = EXT_MAX_BLOCKS;
4518 next_del = es.es_lblk;
4522 /* fiemap flags we can handle specified here */
4523 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4525 static int ext4_xattr_fiemap(struct inode *inode,
4526 struct fiemap_extent_info *fieinfo)
4530 __u32 flags = FIEMAP_EXTENT_LAST;
4531 int blockbits = inode->i_sb->s_blocksize_bits;
4535 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4536 struct ext4_iloc iloc;
4537 int offset; /* offset of xattr in inode */
4539 error = ext4_get_inode_loc(inode, &iloc);
4542 physical = iloc.bh->b_blocknr << blockbits;
4543 offset = EXT4_GOOD_OLD_INODE_SIZE +
4544 EXT4_I(inode)->i_extra_isize;
4546 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4547 flags |= FIEMAP_EXTENT_DATA_INLINE;
4549 } else { /* external block */
4550 physical = EXT4_I(inode)->i_file_acl << blockbits;
4551 length = inode->i_sb->s_blocksize;
4555 error = fiemap_fill_next_extent(fieinfo, 0, physical,
4557 return (error < 0 ? error : 0);
4561 * ext4_ext_punch_hole
4563 * Punches a hole of "length" bytes in a file starting
4566 * @inode: The inode of the file to punch a hole in
4567 * @offset: The starting byte offset of the hole
4568 * @length: The length of the hole
4570 * Returns the number of blocks removed or negative on err
4572 int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
4574 struct inode *inode = file_inode(file);
4575 struct super_block *sb = inode->i_sb;
4576 ext4_lblk_t first_block, stop_block;
4577 struct address_space *mapping = inode->i_mapping;
4579 loff_t first_page, last_page, page_len;
4580 loff_t first_page_offset, last_page_offset;
4581 int credits, err = 0;
4584 * Write out all dirty pages to avoid race conditions
4585 * Then release them.
4587 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
4588 err = filemap_write_and_wait_range(mapping,
4589 offset, offset + length - 1);
4595 mutex_lock(&inode->i_mutex);
4596 /* It's not possible punch hole on append only file */
4597 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {
4601 if (IS_SWAPFILE(inode)) {
4606 /* No need to punch hole beyond i_size */
4607 if (offset >= inode->i_size)
4611 * If the hole extends beyond i_size, set the hole
4612 * to end after the page that contains i_size
4614 if (offset + length > inode->i_size) {
4615 length = inode->i_size +
4616 PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) -
4620 first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
4621 last_page = (offset + length) >> PAGE_CACHE_SHIFT;
4623 first_page_offset = first_page << PAGE_CACHE_SHIFT;
4624 last_page_offset = last_page << PAGE_CACHE_SHIFT;
4626 /* Now release the pages */
4627 if (last_page_offset > first_page_offset) {
4628 truncate_pagecache_range(inode, first_page_offset,
4629 last_page_offset - 1);
4632 /* Wait all existing dio workers, newcomers will block on i_mutex */
4633 ext4_inode_block_unlocked_dio(inode);
4634 err = ext4_flush_unwritten_io(inode);
4637 inode_dio_wait(inode);
4639 credits = ext4_writepage_trans_blocks(inode);
4640 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
4641 if (IS_ERR(handle)) {
4642 err = PTR_ERR(handle);
4648 * Now we need to zero out the non-page-aligned data in the
4649 * pages at the start and tail of the hole, and unmap the buffer
4650 * heads for the block aligned regions of the page that were
4651 * completely zeroed.
4653 if (first_page > last_page) {
4655 * If the file space being truncated is contained within a page
4656 * just zero out and unmap the middle of that page
4658 err = ext4_discard_partial_page_buffers(handle,
4659 mapping, offset, length, 0);
4665 * zero out and unmap the partial page that contains
4666 * the start of the hole
4668 page_len = first_page_offset - offset;
4670 err = ext4_discard_partial_page_buffers(handle, mapping,
4671 offset, page_len, 0);
4677 * zero out and unmap the partial page that contains
4678 * the end of the hole
4680 page_len = offset + length - last_page_offset;
4682 err = ext4_discard_partial_page_buffers(handle, mapping,
4683 last_page_offset, page_len, 0);
4690 * If i_size is contained in the last page, we need to
4691 * unmap and zero the partial page after i_size
4693 if (inode->i_size >> PAGE_CACHE_SHIFT == last_page &&
4694 inode->i_size % PAGE_CACHE_SIZE != 0) {
4696 page_len = PAGE_CACHE_SIZE -
4697 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4700 err = ext4_discard_partial_page_buffers(handle,
4701 mapping, inode->i_size, page_len, 0);
4708 first_block = (offset + sb->s_blocksize - 1) >>
4709 EXT4_BLOCK_SIZE_BITS(sb);
4710 stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
4712 /* If there are no blocks to remove, return now */
4713 if (first_block >= stop_block)
4716 down_write(&EXT4_I(inode)->i_data_sem);
4717 ext4_discard_preallocations(inode);
4719 err = ext4_es_remove_extent(inode, first_block,
4720 stop_block - first_block);
4721 err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
4723 ext4_discard_preallocations(inode);
4726 ext4_handle_sync(handle);
4728 up_write(&EXT4_I(inode)->i_data_sem);
4731 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4732 ext4_mark_inode_dirty(handle, inode);
4733 ext4_journal_stop(handle);
4735 ext4_inode_resume_unlocked_dio(inode);
4737 mutex_unlock(&inode->i_mutex);
4741 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4742 __u64 start, __u64 len)
4744 ext4_lblk_t start_blk;
4747 if (ext4_has_inline_data(inode)) {
4750 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline);
4756 /* fallback to generic here if not in extents fmt */
4757 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4758 return generic_block_fiemap(inode, fieinfo, start, len,
4761 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
4764 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4765 error = ext4_xattr_fiemap(inode, fieinfo);
4767 ext4_lblk_t len_blks;
4770 start_blk = start >> inode->i_sb->s_blocksize_bits;
4771 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
4772 if (last_blk >= EXT_MAX_BLOCKS)
4773 last_blk = EXT_MAX_BLOCKS-1;
4774 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
4777 * Walk the extent tree gathering extent information
4778 * and pushing extents back to the user.
4780 error = ext4_fill_fiemap_extents(inode, start_blk,