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"
45 #include <trace/events/ext4.h>
48 * used by extent splitting.
50 #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
52 #define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
53 #define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
55 #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
56 #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
58 static __le32 ext4_extent_block_csum(struct inode *inode,
59 struct ext4_extent_header *eh)
61 struct ext4_inode_info *ei = EXT4_I(inode);
62 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
65 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
66 EXT4_EXTENT_TAIL_OFFSET(eh));
67 return cpu_to_le32(csum);
70 static int ext4_extent_block_csum_verify(struct inode *inode,
71 struct ext4_extent_header *eh)
73 struct ext4_extent_tail *et;
75 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
76 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
79 et = find_ext4_extent_tail(eh);
80 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
85 static void ext4_extent_block_csum_set(struct inode *inode,
86 struct ext4_extent_header *eh)
88 struct ext4_extent_tail *et;
90 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
91 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
94 et = find_ext4_extent_tail(eh);
95 et->et_checksum = ext4_extent_block_csum(inode, eh);
98 static int ext4_split_extent(handle_t *handle,
100 struct ext4_ext_path *path,
101 struct ext4_map_blocks *map,
105 static int ext4_split_extent_at(handle_t *handle,
107 struct ext4_ext_path *path,
112 static int ext4_find_delayed_extent(struct inode *inode,
113 struct ext4_ext_cache *newex);
115 static int ext4_ext_truncate_extend_restart(handle_t *handle,
121 if (!ext4_handle_valid(handle))
123 if (handle->h_buffer_credits > needed)
125 err = ext4_journal_extend(handle, needed);
128 err = ext4_truncate_restart_trans(handle, inode, needed);
140 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
141 struct ext4_ext_path *path)
144 /* path points to block */
145 return ext4_journal_get_write_access(handle, path->p_bh);
147 /* path points to leaf/index in inode body */
148 /* we use in-core data, no need to protect them */
158 #define ext4_ext_dirty(handle, inode, path) \
159 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
160 static int __ext4_ext_dirty(const char *where, unsigned int line,
161 handle_t *handle, struct inode *inode,
162 struct ext4_ext_path *path)
166 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
167 /* path points to block */
168 err = __ext4_handle_dirty_metadata(where, line, handle,
171 /* path points to leaf/index in inode body */
172 err = ext4_mark_inode_dirty(handle, inode);
177 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
178 struct ext4_ext_path *path,
182 int depth = path->p_depth;
183 struct ext4_extent *ex;
186 * Try to predict block placement assuming that we are
187 * filling in a file which will eventually be
188 * non-sparse --- i.e., in the case of libbfd writing
189 * an ELF object sections out-of-order but in a way
190 * the eventually results in a contiguous object or
191 * executable file, or some database extending a table
192 * space file. However, this is actually somewhat
193 * non-ideal if we are writing a sparse file such as
194 * qemu or KVM writing a raw image file that is going
195 * to stay fairly sparse, since it will end up
196 * fragmenting the file system's free space. Maybe we
197 * should have some hueristics or some way to allow
198 * userspace to pass a hint to file system,
199 * especially if the latter case turns out to be
202 ex = path[depth].p_ext;
204 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
205 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
207 if (block > ext_block)
208 return ext_pblk + (block - ext_block);
210 return ext_pblk - (ext_block - block);
213 /* it looks like index is empty;
214 * try to find starting block from index itself */
215 if (path[depth].p_bh)
216 return path[depth].p_bh->b_blocknr;
219 /* OK. use inode's group */
220 return ext4_inode_to_goal_block(inode);
224 * Allocation for a meta data block
227 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
228 struct ext4_ext_path *path,
229 struct ext4_extent *ex, int *err, unsigned int flags)
231 ext4_fsblk_t goal, newblock;
233 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
234 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
239 static inline int ext4_ext_space_block(struct inode *inode, int check)
243 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
244 / sizeof(struct ext4_extent);
245 #ifdef AGGRESSIVE_TEST
246 if (!check && size > 6)
252 static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
256 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
257 / sizeof(struct ext4_extent_idx);
258 #ifdef AGGRESSIVE_TEST
259 if (!check && size > 5)
265 static inline int ext4_ext_space_root(struct inode *inode, int check)
269 size = sizeof(EXT4_I(inode)->i_data);
270 size -= sizeof(struct ext4_extent_header);
271 size /= sizeof(struct ext4_extent);
272 #ifdef AGGRESSIVE_TEST
273 if (!check && size > 3)
279 static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
283 size = sizeof(EXT4_I(inode)->i_data);
284 size -= sizeof(struct ext4_extent_header);
285 size /= sizeof(struct ext4_extent_idx);
286 #ifdef AGGRESSIVE_TEST
287 if (!check && size > 4)
294 * Calculate the number of metadata blocks needed
295 * to allocate @blocks
296 * Worse case is one block per extent
298 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
300 struct ext4_inode_info *ei = EXT4_I(inode);
303 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
304 / sizeof(struct ext4_extent_idx));
307 * If the new delayed allocation block is contiguous with the
308 * previous da block, it can share index blocks with the
309 * previous block, so we only need to allocate a new index
310 * block every idxs leaf blocks. At ldxs**2 blocks, we need
311 * an additional index block, and at ldxs**3 blocks, yet
312 * another index blocks.
314 if (ei->i_da_metadata_calc_len &&
315 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
318 if ((ei->i_da_metadata_calc_len % idxs) == 0)
320 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
322 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
324 ei->i_da_metadata_calc_len = 0;
326 ei->i_da_metadata_calc_len++;
327 ei->i_da_metadata_calc_last_lblock++;
332 * In the worst case we need a new set of index blocks at
333 * every level of the inode's extent tree.
335 ei->i_da_metadata_calc_len = 1;
336 ei->i_da_metadata_calc_last_lblock = lblock;
337 return ext_depth(inode) + 1;
341 ext4_ext_max_entries(struct inode *inode, int depth)
345 if (depth == ext_depth(inode)) {
347 max = ext4_ext_space_root(inode, 1);
349 max = ext4_ext_space_root_idx(inode, 1);
352 max = ext4_ext_space_block(inode, 1);
354 max = ext4_ext_space_block_idx(inode, 1);
360 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
362 ext4_fsblk_t block = ext4_ext_pblock(ext);
363 int len = ext4_ext_get_actual_len(ext);
367 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
370 static int ext4_valid_extent_idx(struct inode *inode,
371 struct ext4_extent_idx *ext_idx)
373 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
375 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
378 static int ext4_valid_extent_entries(struct inode *inode,
379 struct ext4_extent_header *eh,
382 unsigned short entries;
383 if (eh->eh_entries == 0)
386 entries = le16_to_cpu(eh->eh_entries);
390 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
392 if (!ext4_valid_extent(inode, ext))
398 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
400 if (!ext4_valid_extent_idx(inode, ext_idx))
409 static int __ext4_ext_check(const char *function, unsigned int line,
410 struct inode *inode, struct ext4_extent_header *eh,
413 const char *error_msg;
416 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
417 error_msg = "invalid magic";
420 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
421 error_msg = "unexpected eh_depth";
424 if (unlikely(eh->eh_max == 0)) {
425 error_msg = "invalid eh_max";
428 max = ext4_ext_max_entries(inode, depth);
429 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
430 error_msg = "too large eh_max";
433 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
434 error_msg = "invalid eh_entries";
437 if (!ext4_valid_extent_entries(inode, eh, depth)) {
438 error_msg = "invalid extent entries";
441 /* Verify checksum on non-root extent tree nodes */
442 if (ext_depth(inode) != depth &&
443 !ext4_extent_block_csum_verify(inode, eh)) {
444 error_msg = "extent tree corrupted";
450 ext4_error_inode(inode, function, line, 0,
451 "bad header/extent: %s - magic %x, "
452 "entries %u, max %u(%u), depth %u(%u)",
453 error_msg, le16_to_cpu(eh->eh_magic),
454 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
455 max, le16_to_cpu(eh->eh_depth), depth);
460 #define ext4_ext_check(inode, eh, depth) \
461 __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
463 int ext4_ext_check_inode(struct inode *inode)
465 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
468 static int __ext4_ext_check_block(const char *function, unsigned int line,
470 struct ext4_extent_header *eh,
472 struct buffer_head *bh)
476 if (buffer_verified(bh))
478 ret = ext4_ext_check(inode, eh, depth);
481 set_buffer_verified(bh);
485 #define ext4_ext_check_block(inode, eh, depth, bh) \
486 __ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
489 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
491 int k, l = path->p_depth;
494 for (k = 0; k <= l; k++, path++) {
496 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
497 ext4_idx_pblock(path->p_idx));
498 } else if (path->p_ext) {
499 ext_debug(" %d:[%d]%d:%llu ",
500 le32_to_cpu(path->p_ext->ee_block),
501 ext4_ext_is_uninitialized(path->p_ext),
502 ext4_ext_get_actual_len(path->p_ext),
503 ext4_ext_pblock(path->p_ext));
510 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
512 int depth = ext_depth(inode);
513 struct ext4_extent_header *eh;
514 struct ext4_extent *ex;
520 eh = path[depth].p_hdr;
521 ex = EXT_FIRST_EXTENT(eh);
523 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
525 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
526 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
527 ext4_ext_is_uninitialized(ex),
528 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
533 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
534 ext4_fsblk_t newblock, int level)
536 int depth = ext_depth(inode);
537 struct ext4_extent *ex;
539 if (depth != level) {
540 struct ext4_extent_idx *idx;
541 idx = path[level].p_idx;
542 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
543 ext_debug("%d: move %d:%llu in new index %llu\n", level,
544 le32_to_cpu(idx->ei_block),
545 ext4_idx_pblock(idx),
553 ex = path[depth].p_ext;
554 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
555 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
556 le32_to_cpu(ex->ee_block),
558 ext4_ext_is_uninitialized(ex),
559 ext4_ext_get_actual_len(ex),
566 #define ext4_ext_show_path(inode, path)
567 #define ext4_ext_show_leaf(inode, path)
568 #define ext4_ext_show_move(inode, path, newblock, level)
571 void ext4_ext_drop_refs(struct ext4_ext_path *path)
573 int depth = path->p_depth;
576 for (i = 0; i <= depth; i++, path++)
584 * ext4_ext_binsearch_idx:
585 * binary search for the closest index of the given block
586 * the header must be checked before calling this
589 ext4_ext_binsearch_idx(struct inode *inode,
590 struct ext4_ext_path *path, ext4_lblk_t block)
592 struct ext4_extent_header *eh = path->p_hdr;
593 struct ext4_extent_idx *r, *l, *m;
596 ext_debug("binsearch for %u(idx): ", block);
598 l = EXT_FIRST_INDEX(eh) + 1;
599 r = EXT_LAST_INDEX(eh);
602 if (block < le32_to_cpu(m->ei_block))
606 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
607 m, le32_to_cpu(m->ei_block),
608 r, le32_to_cpu(r->ei_block));
612 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
613 ext4_idx_pblock(path->p_idx));
615 #ifdef CHECK_BINSEARCH
617 struct ext4_extent_idx *chix, *ix;
620 chix = ix = EXT_FIRST_INDEX(eh);
621 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
623 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
624 printk(KERN_DEBUG "k=%d, ix=0x%p, "
626 ix, EXT_FIRST_INDEX(eh));
627 printk(KERN_DEBUG "%u <= %u\n",
628 le32_to_cpu(ix->ei_block),
629 le32_to_cpu(ix[-1].ei_block));
631 BUG_ON(k && le32_to_cpu(ix->ei_block)
632 <= le32_to_cpu(ix[-1].ei_block));
633 if (block < le32_to_cpu(ix->ei_block))
637 BUG_ON(chix != path->p_idx);
644 * ext4_ext_binsearch:
645 * binary search for closest extent of the given block
646 * the header must be checked before calling this
649 ext4_ext_binsearch(struct inode *inode,
650 struct ext4_ext_path *path, ext4_lblk_t block)
652 struct ext4_extent_header *eh = path->p_hdr;
653 struct ext4_extent *r, *l, *m;
655 if (eh->eh_entries == 0) {
657 * this leaf is empty:
658 * we get such a leaf in split/add case
663 ext_debug("binsearch for %u: ", block);
665 l = EXT_FIRST_EXTENT(eh) + 1;
666 r = EXT_LAST_EXTENT(eh);
670 if (block < le32_to_cpu(m->ee_block))
674 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
675 m, le32_to_cpu(m->ee_block),
676 r, le32_to_cpu(r->ee_block));
680 ext_debug(" -> %d:%llu:[%d]%d ",
681 le32_to_cpu(path->p_ext->ee_block),
682 ext4_ext_pblock(path->p_ext),
683 ext4_ext_is_uninitialized(path->p_ext),
684 ext4_ext_get_actual_len(path->p_ext));
686 #ifdef CHECK_BINSEARCH
688 struct ext4_extent *chex, *ex;
691 chex = ex = EXT_FIRST_EXTENT(eh);
692 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
693 BUG_ON(k && le32_to_cpu(ex->ee_block)
694 <= le32_to_cpu(ex[-1].ee_block));
695 if (block < le32_to_cpu(ex->ee_block))
699 BUG_ON(chex != path->p_ext);
705 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
707 struct ext4_extent_header *eh;
709 eh = ext_inode_hdr(inode);
712 eh->eh_magic = EXT4_EXT_MAGIC;
713 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
714 ext4_mark_inode_dirty(handle, inode);
715 ext4_ext_invalidate_cache(inode);
719 struct ext4_ext_path *
720 ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
721 struct ext4_ext_path *path)
723 struct ext4_extent_header *eh;
724 struct buffer_head *bh;
725 short int depth, i, ppos = 0, alloc = 0;
727 eh = ext_inode_hdr(inode);
728 depth = ext_depth(inode);
730 /* account possible depth increase */
732 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
735 return ERR_PTR(-ENOMEM);
742 /* walk through the tree */
744 ext_debug("depth %d: num %d, max %d\n",
745 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
747 ext4_ext_binsearch_idx(inode, path + ppos, block);
748 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
749 path[ppos].p_depth = i;
750 path[ppos].p_ext = NULL;
752 bh = sb_getblk(inode->i_sb, path[ppos].p_block);
755 if (!bh_uptodate_or_lock(bh)) {
756 trace_ext4_ext_load_extent(inode, block,
758 if (bh_submit_read(bh) < 0) {
763 eh = ext_block_hdr(bh);
765 if (unlikely(ppos > depth)) {
767 EXT4_ERROR_INODE(inode,
768 "ppos %d > depth %d", ppos, depth);
771 path[ppos].p_bh = bh;
772 path[ppos].p_hdr = eh;
775 if (ext4_ext_check_block(inode, eh, i, bh))
779 path[ppos].p_depth = i;
780 path[ppos].p_ext = NULL;
781 path[ppos].p_idx = NULL;
784 ext4_ext_binsearch(inode, path + ppos, block);
785 /* if not an empty leaf */
786 if (path[ppos].p_ext)
787 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
789 ext4_ext_show_path(inode, path);
794 ext4_ext_drop_refs(path);
797 return ERR_PTR(-EIO);
801 * ext4_ext_insert_index:
802 * insert new index [@logical;@ptr] into the block at @curp;
803 * check where to insert: before @curp or after @curp
805 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
806 struct ext4_ext_path *curp,
807 int logical, ext4_fsblk_t ptr)
809 struct ext4_extent_idx *ix;
812 err = ext4_ext_get_access(handle, inode, curp);
816 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
817 EXT4_ERROR_INODE(inode,
818 "logical %d == ei_block %d!",
819 logical, le32_to_cpu(curp->p_idx->ei_block));
823 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
824 >= le16_to_cpu(curp->p_hdr->eh_max))) {
825 EXT4_ERROR_INODE(inode,
826 "eh_entries %d >= eh_max %d!",
827 le16_to_cpu(curp->p_hdr->eh_entries),
828 le16_to_cpu(curp->p_hdr->eh_max));
832 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
834 ext_debug("insert new index %d after: %llu\n", logical, ptr);
835 ix = curp->p_idx + 1;
838 ext_debug("insert new index %d before: %llu\n", logical, ptr);
842 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
845 ext_debug("insert new index %d: "
846 "move %d indices from 0x%p to 0x%p\n",
847 logical, len, ix, ix + 1);
848 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
851 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
852 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
856 ix->ei_block = cpu_to_le32(logical);
857 ext4_idx_store_pblock(ix, ptr);
858 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
860 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
861 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
865 err = ext4_ext_dirty(handle, inode, curp);
866 ext4_std_error(inode->i_sb, err);
873 * inserts new subtree into the path, using free index entry
875 * - allocates all needed blocks (new leaf and all intermediate index blocks)
876 * - makes decision where to split
877 * - moves remaining extents and index entries (right to the split point)
878 * into the newly allocated blocks
879 * - initializes subtree
881 static int ext4_ext_split(handle_t *handle, struct inode *inode,
883 struct ext4_ext_path *path,
884 struct ext4_extent *newext, int at)
886 struct buffer_head *bh = NULL;
887 int depth = ext_depth(inode);
888 struct ext4_extent_header *neh;
889 struct ext4_extent_idx *fidx;
891 ext4_fsblk_t newblock, oldblock;
893 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
896 /* make decision: where to split? */
897 /* FIXME: now decision is simplest: at current extent */
899 /* if current leaf will be split, then we should use
900 * border from split point */
901 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
902 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
905 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
906 border = path[depth].p_ext[1].ee_block;
907 ext_debug("leaf will be split."
908 " next leaf starts at %d\n",
909 le32_to_cpu(border));
911 border = newext->ee_block;
912 ext_debug("leaf will be added."
913 " next leaf starts at %d\n",
914 le32_to_cpu(border));
918 * If error occurs, then we break processing
919 * and mark filesystem read-only. index won't
920 * be inserted and tree will be in consistent
921 * state. Next mount will repair buffers too.
925 * Get array to track all allocated blocks.
926 * We need this to handle errors and free blocks
929 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
933 /* allocate all needed blocks */
934 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
935 for (a = 0; a < depth - at; a++) {
936 newblock = ext4_ext_new_meta_block(handle, inode, path,
937 newext, &err, flags);
940 ablocks[a] = newblock;
943 /* initialize new leaf */
944 newblock = ablocks[--a];
945 if (unlikely(newblock == 0)) {
946 EXT4_ERROR_INODE(inode, "newblock == 0!");
950 bh = sb_getblk(inode->i_sb, newblock);
957 err = ext4_journal_get_create_access(handle, bh);
961 neh = ext_block_hdr(bh);
963 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
964 neh->eh_magic = EXT4_EXT_MAGIC;
967 /* move remainder of path[depth] to the new leaf */
968 if (unlikely(path[depth].p_hdr->eh_entries !=
969 path[depth].p_hdr->eh_max)) {
970 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
971 path[depth].p_hdr->eh_entries,
972 path[depth].p_hdr->eh_max);
976 /* start copy from next extent */
977 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
978 ext4_ext_show_move(inode, path, newblock, depth);
980 struct ext4_extent *ex;
981 ex = EXT_FIRST_EXTENT(neh);
982 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
983 le16_add_cpu(&neh->eh_entries, m);
986 ext4_extent_block_csum_set(inode, neh);
987 set_buffer_uptodate(bh);
990 err = ext4_handle_dirty_metadata(handle, inode, bh);
996 /* correct old leaf */
998 err = ext4_ext_get_access(handle, inode, path + depth);
1001 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1002 err = ext4_ext_dirty(handle, inode, path + depth);
1008 /* create intermediate indexes */
1010 if (unlikely(k < 0)) {
1011 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1016 ext_debug("create %d intermediate indices\n", k);
1017 /* insert new index into current index block */
1018 /* current depth stored in i var */
1021 oldblock = newblock;
1022 newblock = ablocks[--a];
1023 bh = sb_getblk(inode->i_sb, newblock);
1030 err = ext4_journal_get_create_access(handle, bh);
1034 neh = ext_block_hdr(bh);
1035 neh->eh_entries = cpu_to_le16(1);
1036 neh->eh_magic = EXT4_EXT_MAGIC;
1037 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1038 neh->eh_depth = cpu_to_le16(depth - i);
1039 fidx = EXT_FIRST_INDEX(neh);
1040 fidx->ei_block = border;
1041 ext4_idx_store_pblock(fidx, oldblock);
1043 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1044 i, newblock, le32_to_cpu(border), oldblock);
1046 /* move remainder of path[i] to the new index block */
1047 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1048 EXT_LAST_INDEX(path[i].p_hdr))) {
1049 EXT4_ERROR_INODE(inode,
1050 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1051 le32_to_cpu(path[i].p_ext->ee_block));
1055 /* start copy indexes */
1056 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1057 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1058 EXT_MAX_INDEX(path[i].p_hdr));
1059 ext4_ext_show_move(inode, path, newblock, i);
1061 memmove(++fidx, path[i].p_idx,
1062 sizeof(struct ext4_extent_idx) * m);
1063 le16_add_cpu(&neh->eh_entries, m);
1065 ext4_extent_block_csum_set(inode, neh);
1066 set_buffer_uptodate(bh);
1069 err = ext4_handle_dirty_metadata(handle, inode, bh);
1075 /* correct old index */
1077 err = ext4_ext_get_access(handle, inode, path + i);
1080 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1081 err = ext4_ext_dirty(handle, inode, path + i);
1089 /* insert new index */
1090 err = ext4_ext_insert_index(handle, inode, path + at,
1091 le32_to_cpu(border), newblock);
1095 if (buffer_locked(bh))
1101 /* free all allocated blocks in error case */
1102 for (i = 0; i < depth; i++) {
1105 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1106 EXT4_FREE_BLOCKS_METADATA);
1115 * ext4_ext_grow_indepth:
1116 * implements tree growing procedure:
1117 * - allocates new block
1118 * - moves top-level data (index block or leaf) into the new block
1119 * - initializes new top-level, creating index that points to the
1120 * just created block
1122 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1124 struct ext4_extent *newext)
1126 struct ext4_extent_header *neh;
1127 struct buffer_head *bh;
1128 ext4_fsblk_t newblock;
1131 newblock = ext4_ext_new_meta_block(handle, inode, NULL,
1132 newext, &err, flags);
1136 bh = sb_getblk(inode->i_sb, newblock);
1139 ext4_std_error(inode->i_sb, err);
1144 err = ext4_journal_get_create_access(handle, bh);
1150 /* move top-level index/leaf into new block */
1151 memmove(bh->b_data, EXT4_I(inode)->i_data,
1152 sizeof(EXT4_I(inode)->i_data));
1154 /* set size of new block */
1155 neh = ext_block_hdr(bh);
1156 /* old root could have indexes or leaves
1157 * so calculate e_max right way */
1158 if (ext_depth(inode))
1159 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1161 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1162 neh->eh_magic = EXT4_EXT_MAGIC;
1163 ext4_extent_block_csum_set(inode, neh);
1164 set_buffer_uptodate(bh);
1167 err = ext4_handle_dirty_metadata(handle, inode, bh);
1171 /* Update top-level index: num,max,pointer */
1172 neh = ext_inode_hdr(inode);
1173 neh->eh_entries = cpu_to_le16(1);
1174 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1175 if (neh->eh_depth == 0) {
1176 /* Root extent block becomes index block */
1177 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1178 EXT_FIRST_INDEX(neh)->ei_block =
1179 EXT_FIRST_EXTENT(neh)->ee_block;
1181 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1182 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1183 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1184 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1186 le16_add_cpu(&neh->eh_depth, 1);
1187 ext4_mark_inode_dirty(handle, inode);
1195 * ext4_ext_create_new_leaf:
1196 * finds empty index and adds new leaf.
1197 * if no free index is found, then it requests in-depth growing.
1199 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1201 struct ext4_ext_path *path,
1202 struct ext4_extent *newext)
1204 struct ext4_ext_path *curp;
1205 int depth, i, err = 0;
1208 i = depth = ext_depth(inode);
1210 /* walk up to the tree and look for free index entry */
1211 curp = path + depth;
1212 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1217 /* we use already allocated block for index block,
1218 * so subsequent data blocks should be contiguous */
1219 if (EXT_HAS_FREE_INDEX(curp)) {
1220 /* if we found index with free entry, then use that
1221 * entry: create all needed subtree and add new leaf */
1222 err = ext4_ext_split(handle, inode, flags, path, newext, i);
1227 ext4_ext_drop_refs(path);
1228 path = ext4_ext_find_extent(inode,
1229 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1232 err = PTR_ERR(path);
1234 /* tree is full, time to grow in depth */
1235 err = ext4_ext_grow_indepth(handle, inode, flags, newext);
1240 ext4_ext_drop_refs(path);
1241 path = ext4_ext_find_extent(inode,
1242 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1245 err = PTR_ERR(path);
1250 * only first (depth 0 -> 1) produces free space;
1251 * in all other cases we have to split the grown tree
1253 depth = ext_depth(inode);
1254 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1255 /* now we need to split */
1265 * search the closest allocated block to the left for *logical
1266 * and returns it at @logical + it's physical address at @phys
1267 * if *logical is the smallest allocated block, the function
1268 * returns 0 at @phys
1269 * return value contains 0 (success) or error code
1271 static int ext4_ext_search_left(struct inode *inode,
1272 struct ext4_ext_path *path,
1273 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1275 struct ext4_extent_idx *ix;
1276 struct ext4_extent *ex;
1279 if (unlikely(path == NULL)) {
1280 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1283 depth = path->p_depth;
1286 if (depth == 0 && path->p_ext == NULL)
1289 /* usually extent in the path covers blocks smaller
1290 * then *logical, but it can be that extent is the
1291 * first one in the file */
1293 ex = path[depth].p_ext;
1294 ee_len = ext4_ext_get_actual_len(ex);
1295 if (*logical < le32_to_cpu(ex->ee_block)) {
1296 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1297 EXT4_ERROR_INODE(inode,
1298 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1299 *logical, le32_to_cpu(ex->ee_block));
1302 while (--depth >= 0) {
1303 ix = path[depth].p_idx;
1304 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1305 EXT4_ERROR_INODE(inode,
1306 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1307 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1308 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1309 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1317 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1318 EXT4_ERROR_INODE(inode,
1319 "logical %d < ee_block %d + ee_len %d!",
1320 *logical, le32_to_cpu(ex->ee_block), ee_len);
1324 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1325 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1330 * search the closest allocated block to the right for *logical
1331 * and returns it at @logical + it's physical address at @phys
1332 * if *logical is the largest allocated block, the function
1333 * returns 0 at @phys
1334 * return value contains 0 (success) or error code
1336 static int ext4_ext_search_right(struct inode *inode,
1337 struct ext4_ext_path *path,
1338 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1339 struct ext4_extent **ret_ex)
1341 struct buffer_head *bh = NULL;
1342 struct ext4_extent_header *eh;
1343 struct ext4_extent_idx *ix;
1344 struct ext4_extent *ex;
1346 int depth; /* Note, NOT eh_depth; depth from top of tree */
1349 if (unlikely(path == NULL)) {
1350 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1353 depth = path->p_depth;
1356 if (depth == 0 && path->p_ext == NULL)
1359 /* usually extent in the path covers blocks smaller
1360 * then *logical, but it can be that extent is the
1361 * first one in the file */
1363 ex = path[depth].p_ext;
1364 ee_len = ext4_ext_get_actual_len(ex);
1365 if (*logical < le32_to_cpu(ex->ee_block)) {
1366 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1367 EXT4_ERROR_INODE(inode,
1368 "first_extent(path[%d].p_hdr) != ex",
1372 while (--depth >= 0) {
1373 ix = path[depth].p_idx;
1374 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1375 EXT4_ERROR_INODE(inode,
1376 "ix != EXT_FIRST_INDEX *logical %d!",
1384 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1385 EXT4_ERROR_INODE(inode,
1386 "logical %d < ee_block %d + ee_len %d!",
1387 *logical, le32_to_cpu(ex->ee_block), ee_len);
1391 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1392 /* next allocated block in this leaf */
1397 /* go up and search for index to the right */
1398 while (--depth >= 0) {
1399 ix = path[depth].p_idx;
1400 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1404 /* we've gone up to the root and found no index to the right */
1408 /* we've found index to the right, let's
1409 * follow it and find the closest allocated
1410 * block to the right */
1412 block = ext4_idx_pblock(ix);
1413 while (++depth < path->p_depth) {
1414 bh = sb_bread(inode->i_sb, block);
1417 eh = ext_block_hdr(bh);
1418 /* subtract from p_depth to get proper eh_depth */
1419 if (ext4_ext_check_block(inode, eh,
1420 path->p_depth - depth, bh)) {
1424 ix = EXT_FIRST_INDEX(eh);
1425 block = ext4_idx_pblock(ix);
1429 bh = sb_bread(inode->i_sb, block);
1432 eh = ext_block_hdr(bh);
1433 if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
1437 ex = EXT_FIRST_EXTENT(eh);
1439 *logical = le32_to_cpu(ex->ee_block);
1440 *phys = ext4_ext_pblock(ex);
1448 * ext4_ext_next_allocated_block:
1449 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1450 * NOTE: it considers block number from index entry as
1451 * allocated block. Thus, index entries have to be consistent
1455 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1459 BUG_ON(path == NULL);
1460 depth = path->p_depth;
1462 if (depth == 0 && path->p_ext == NULL)
1463 return EXT_MAX_BLOCKS;
1465 while (depth >= 0) {
1466 if (depth == path->p_depth) {
1468 if (path[depth].p_ext &&
1469 path[depth].p_ext !=
1470 EXT_LAST_EXTENT(path[depth].p_hdr))
1471 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1474 if (path[depth].p_idx !=
1475 EXT_LAST_INDEX(path[depth].p_hdr))
1476 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1481 return EXT_MAX_BLOCKS;
1485 * ext4_ext_next_leaf_block:
1486 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1488 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1492 BUG_ON(path == NULL);
1493 depth = path->p_depth;
1495 /* zero-tree has no leaf blocks at all */
1497 return EXT_MAX_BLOCKS;
1499 /* go to index block */
1502 while (depth >= 0) {
1503 if (path[depth].p_idx !=
1504 EXT_LAST_INDEX(path[depth].p_hdr))
1505 return (ext4_lblk_t)
1506 le32_to_cpu(path[depth].p_idx[1].ei_block);
1510 return EXT_MAX_BLOCKS;
1514 * ext4_ext_correct_indexes:
1515 * if leaf gets modified and modified extent is first in the leaf,
1516 * then we have to correct all indexes above.
1517 * TODO: do we need to correct tree in all cases?
1519 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1520 struct ext4_ext_path *path)
1522 struct ext4_extent_header *eh;
1523 int depth = ext_depth(inode);
1524 struct ext4_extent *ex;
1528 eh = path[depth].p_hdr;
1529 ex = path[depth].p_ext;
1531 if (unlikely(ex == NULL || eh == NULL)) {
1532 EXT4_ERROR_INODE(inode,
1533 "ex %p == NULL or eh %p == NULL", ex, eh);
1538 /* there is no tree at all */
1542 if (ex != EXT_FIRST_EXTENT(eh)) {
1543 /* we correct tree if first leaf got modified only */
1548 * TODO: we need correction if border is smaller than current one
1551 border = path[depth].p_ext->ee_block;
1552 err = ext4_ext_get_access(handle, inode, path + k);
1555 path[k].p_idx->ei_block = border;
1556 err = ext4_ext_dirty(handle, inode, path + k);
1561 /* change all left-side indexes */
1562 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1564 err = ext4_ext_get_access(handle, inode, path + k);
1567 path[k].p_idx->ei_block = border;
1568 err = ext4_ext_dirty(handle, inode, path + k);
1577 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1578 struct ext4_extent *ex2)
1580 unsigned short ext1_ee_len, ext2_ee_len, max_len;
1583 * Make sure that either both extents are uninitialized, or
1586 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1589 if (ext4_ext_is_uninitialized(ex1))
1590 max_len = EXT_UNINIT_MAX_LEN;
1592 max_len = EXT_INIT_MAX_LEN;
1594 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1595 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1597 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1598 le32_to_cpu(ex2->ee_block))
1602 * To allow future support for preallocated extents to be added
1603 * as an RO_COMPAT feature, refuse to merge to extents if
1604 * this can result in the top bit of ee_len being set.
1606 if (ext1_ee_len + ext2_ee_len > max_len)
1608 #ifdef AGGRESSIVE_TEST
1609 if (ext1_ee_len >= 4)
1613 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1619 * This function tries to merge the "ex" extent to the next extent in the tree.
1620 * It always tries to merge towards right. If you want to merge towards
1621 * left, pass "ex - 1" as argument instead of "ex".
1622 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1623 * 1 if they got merged.
1625 static int ext4_ext_try_to_merge_right(struct inode *inode,
1626 struct ext4_ext_path *path,
1627 struct ext4_extent *ex)
1629 struct ext4_extent_header *eh;
1630 unsigned int depth, len;
1632 int uninitialized = 0;
1634 depth = ext_depth(inode);
1635 BUG_ON(path[depth].p_hdr == NULL);
1636 eh = path[depth].p_hdr;
1638 while (ex < EXT_LAST_EXTENT(eh)) {
1639 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1641 /* merge with next extent! */
1642 if (ext4_ext_is_uninitialized(ex))
1644 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1645 + ext4_ext_get_actual_len(ex + 1));
1647 ext4_ext_mark_uninitialized(ex);
1649 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1650 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1651 * sizeof(struct ext4_extent);
1652 memmove(ex + 1, ex + 2, len);
1654 le16_add_cpu(&eh->eh_entries, -1);
1656 WARN_ON(eh->eh_entries == 0);
1657 if (!eh->eh_entries)
1658 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1665 * This function does a very simple check to see if we can collapse
1666 * an extent tree with a single extent tree leaf block into the inode.
1668 static void ext4_ext_try_to_merge_up(handle_t *handle,
1669 struct inode *inode,
1670 struct ext4_ext_path *path)
1673 unsigned max_root = ext4_ext_space_root(inode, 0);
1676 if ((path[0].p_depth != 1) ||
1677 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1678 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1682 * We need to modify the block allocation bitmap and the block
1683 * group descriptor to release the extent tree block. If we
1684 * can't get the journal credits, give up.
1686 if (ext4_journal_extend(handle, 2))
1690 * Copy the extent data up to the inode
1692 blk = ext4_idx_pblock(path[0].p_idx);
1693 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1694 sizeof(struct ext4_extent_idx);
1695 s += sizeof(struct ext4_extent_header);
1697 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1698 path[0].p_depth = 0;
1699 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1700 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1701 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1703 brelse(path[1].p_bh);
1704 ext4_free_blocks(handle, inode, NULL, blk, 1,
1705 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1709 * This function tries to merge the @ex extent to neighbours in the tree.
1710 * return 1 if merge left else 0.
1712 static void ext4_ext_try_to_merge(handle_t *handle,
1713 struct inode *inode,
1714 struct ext4_ext_path *path,
1715 struct ext4_extent *ex) {
1716 struct ext4_extent_header *eh;
1720 depth = ext_depth(inode);
1721 BUG_ON(path[depth].p_hdr == NULL);
1722 eh = path[depth].p_hdr;
1724 if (ex > EXT_FIRST_EXTENT(eh))
1725 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1728 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1730 ext4_ext_try_to_merge_up(handle, inode, path);
1734 * check if a portion of the "newext" extent overlaps with an
1737 * If there is an overlap discovered, it updates the length of the newext
1738 * such that there will be no overlap, and then returns 1.
1739 * If there is no overlap found, it returns 0.
1741 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1742 struct inode *inode,
1743 struct ext4_extent *newext,
1744 struct ext4_ext_path *path)
1747 unsigned int depth, len1;
1748 unsigned int ret = 0;
1750 b1 = le32_to_cpu(newext->ee_block);
1751 len1 = ext4_ext_get_actual_len(newext);
1752 depth = ext_depth(inode);
1753 if (!path[depth].p_ext)
1755 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1756 b2 &= ~(sbi->s_cluster_ratio - 1);
1759 * get the next allocated block if the extent in the path
1760 * is before the requested block(s)
1763 b2 = ext4_ext_next_allocated_block(path);
1764 if (b2 == EXT_MAX_BLOCKS)
1766 b2 &= ~(sbi->s_cluster_ratio - 1);
1769 /* check for wrap through zero on extent logical start block*/
1770 if (b1 + len1 < b1) {
1771 len1 = EXT_MAX_BLOCKS - b1;
1772 newext->ee_len = cpu_to_le16(len1);
1776 /* check for overlap */
1777 if (b1 + len1 > b2) {
1778 newext->ee_len = cpu_to_le16(b2 - b1);
1786 * ext4_ext_insert_extent:
1787 * tries to merge requsted extent into the existing extent or
1788 * inserts requested extent as new one into the tree,
1789 * creating new leaf in the no-space case.
1791 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1792 struct ext4_ext_path *path,
1793 struct ext4_extent *newext, int flag)
1795 struct ext4_extent_header *eh;
1796 struct ext4_extent *ex, *fex;
1797 struct ext4_extent *nearex; /* nearest extent */
1798 struct ext4_ext_path *npath = NULL;
1799 int depth, len, err;
1801 unsigned uninitialized = 0;
1804 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1805 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1808 depth = ext_depth(inode);
1809 ex = path[depth].p_ext;
1810 if (unlikely(path[depth].p_hdr == NULL)) {
1811 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1815 /* try to insert block into found extent and return */
1816 if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
1817 && ext4_can_extents_be_merged(inode, ex, newext)) {
1818 ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n",
1819 ext4_ext_is_uninitialized(newext),
1820 ext4_ext_get_actual_len(newext),
1821 le32_to_cpu(ex->ee_block),
1822 ext4_ext_is_uninitialized(ex),
1823 ext4_ext_get_actual_len(ex),
1824 ext4_ext_pblock(ex));
1825 err = ext4_ext_get_access(handle, inode, path + depth);
1830 * ext4_can_extents_be_merged should have checked that either
1831 * both extents are uninitialized, or both aren't. Thus we
1832 * need to check only one of them here.
1834 if (ext4_ext_is_uninitialized(ex))
1836 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1837 + ext4_ext_get_actual_len(newext));
1839 ext4_ext_mark_uninitialized(ex);
1840 eh = path[depth].p_hdr;
1845 depth = ext_depth(inode);
1846 eh = path[depth].p_hdr;
1847 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1850 /* probably next leaf has space for us? */
1851 fex = EXT_LAST_EXTENT(eh);
1852 next = EXT_MAX_BLOCKS;
1853 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
1854 next = ext4_ext_next_leaf_block(path);
1855 if (next != EXT_MAX_BLOCKS) {
1856 ext_debug("next leaf block - %u\n", next);
1857 BUG_ON(npath != NULL);
1858 npath = ext4_ext_find_extent(inode, next, NULL);
1860 return PTR_ERR(npath);
1861 BUG_ON(npath->p_depth != path->p_depth);
1862 eh = npath[depth].p_hdr;
1863 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1864 ext_debug("next leaf isn't full(%d)\n",
1865 le16_to_cpu(eh->eh_entries));
1869 ext_debug("next leaf has no free space(%d,%d)\n",
1870 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1874 * There is no free space in the found leaf.
1875 * We're gonna add a new leaf in the tree.
1877 if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
1878 flags = EXT4_MB_USE_ROOT_BLOCKS;
1879 err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
1882 depth = ext_depth(inode);
1883 eh = path[depth].p_hdr;
1886 nearex = path[depth].p_ext;
1888 err = ext4_ext_get_access(handle, inode, path + depth);
1893 /* there is no extent in this leaf, create first one */
1894 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
1895 le32_to_cpu(newext->ee_block),
1896 ext4_ext_pblock(newext),
1897 ext4_ext_is_uninitialized(newext),
1898 ext4_ext_get_actual_len(newext));
1899 nearex = EXT_FIRST_EXTENT(eh);
1901 if (le32_to_cpu(newext->ee_block)
1902 > le32_to_cpu(nearex->ee_block)) {
1904 ext_debug("insert %u:%llu:[%d]%d before: "
1906 le32_to_cpu(newext->ee_block),
1907 ext4_ext_pblock(newext),
1908 ext4_ext_is_uninitialized(newext),
1909 ext4_ext_get_actual_len(newext),
1914 BUG_ON(newext->ee_block == nearex->ee_block);
1915 ext_debug("insert %u:%llu:[%d]%d after: "
1917 le32_to_cpu(newext->ee_block),
1918 ext4_ext_pblock(newext),
1919 ext4_ext_is_uninitialized(newext),
1920 ext4_ext_get_actual_len(newext),
1923 len = EXT_LAST_EXTENT(eh) - nearex + 1;
1925 ext_debug("insert %u:%llu:[%d]%d: "
1926 "move %d extents from 0x%p to 0x%p\n",
1927 le32_to_cpu(newext->ee_block),
1928 ext4_ext_pblock(newext),
1929 ext4_ext_is_uninitialized(newext),
1930 ext4_ext_get_actual_len(newext),
1931 len, nearex, nearex + 1);
1932 memmove(nearex + 1, nearex,
1933 len * sizeof(struct ext4_extent));
1937 le16_add_cpu(&eh->eh_entries, 1);
1938 path[depth].p_ext = nearex;
1939 nearex->ee_block = newext->ee_block;
1940 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
1941 nearex->ee_len = newext->ee_len;
1944 /* try to merge extents */
1945 if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
1946 ext4_ext_try_to_merge(handle, inode, path, nearex);
1949 /* time to correct all indexes above */
1950 err = ext4_ext_correct_indexes(handle, inode, path);
1954 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
1958 ext4_ext_drop_refs(npath);
1961 ext4_ext_invalidate_cache(inode);
1965 static int ext4_fill_fiemap_extents(struct inode *inode,
1966 ext4_lblk_t block, ext4_lblk_t num,
1967 struct fiemap_extent_info *fieinfo)
1969 struct ext4_ext_path *path = NULL;
1970 struct ext4_ext_cache cbex;
1971 struct ext4_extent *ex;
1972 ext4_lblk_t next, next_del, start = 0, end = 0;
1973 ext4_lblk_t last = block + num;
1974 int exists, depth = 0, err = 0;
1975 unsigned int flags = 0;
1976 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
1978 while (block < last && block != EXT_MAX_BLOCKS) {
1980 /* find extent for this block */
1981 down_read(&EXT4_I(inode)->i_data_sem);
1983 if (path && ext_depth(inode) != depth) {
1984 /* depth was changed. we have to realloc path */
1989 path = ext4_ext_find_extent(inode, block, path);
1991 up_read(&EXT4_I(inode)->i_data_sem);
1992 err = PTR_ERR(path);
1997 depth = ext_depth(inode);
1998 if (unlikely(path[depth].p_hdr == NULL)) {
1999 up_read(&EXT4_I(inode)->i_data_sem);
2000 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2004 ex = path[depth].p_ext;
2005 next = ext4_ext_next_allocated_block(path);
2006 ext4_ext_drop_refs(path);
2011 /* there is no extent yet, so try to allocate
2012 * all requested space */
2015 } else if (le32_to_cpu(ex->ee_block) > block) {
2016 /* need to allocate space before found extent */
2018 end = le32_to_cpu(ex->ee_block);
2019 if (block + num < end)
2021 } else if (block >= le32_to_cpu(ex->ee_block)
2022 + ext4_ext_get_actual_len(ex)) {
2023 /* need to allocate space after found extent */
2028 } else if (block >= le32_to_cpu(ex->ee_block)) {
2030 * some part of requested space is covered
2034 end = le32_to_cpu(ex->ee_block)
2035 + ext4_ext_get_actual_len(ex);
2036 if (block + num < end)
2042 BUG_ON(end <= start);
2045 cbex.ec_block = start;
2046 cbex.ec_len = end - start;
2049 cbex.ec_block = le32_to_cpu(ex->ee_block);
2050 cbex.ec_len = ext4_ext_get_actual_len(ex);
2051 cbex.ec_start = ext4_ext_pblock(ex);
2052 if (ext4_ext_is_uninitialized(ex))
2053 flags |= FIEMAP_EXTENT_UNWRITTEN;
2057 * Find delayed extent and update cbex accordingly. We call
2058 * it even in !exists case to find out whether cbex is the
2059 * last existing extent or not.
2061 next_del = ext4_find_delayed_extent(inode, &cbex);
2062 if (!exists && next_del) {
2064 flags |= FIEMAP_EXTENT_DELALLOC;
2066 up_read(&EXT4_I(inode)->i_data_sem);
2068 if (unlikely(cbex.ec_len == 0)) {
2069 EXT4_ERROR_INODE(inode, "cbex.ec_len == 0");
2074 /* This is possible iff next == next_del == EXT_MAX_BLOCKS */
2075 if (next == next_del) {
2076 flags |= FIEMAP_EXTENT_LAST;
2077 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2078 next != EXT_MAX_BLOCKS)) {
2079 EXT4_ERROR_INODE(inode,
2080 "next extent == %u, next "
2081 "delalloc extent = %u",
2089 err = fiemap_fill_next_extent(fieinfo,
2090 (__u64)cbex.ec_block << blksize_bits,
2091 (__u64)cbex.ec_start << blksize_bits,
2092 (__u64)cbex.ec_len << blksize_bits,
2102 block = cbex.ec_block + cbex.ec_len;
2106 ext4_ext_drop_refs(path);
2114 ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
2115 __u32 len, ext4_fsblk_t start)
2117 struct ext4_ext_cache *cex;
2119 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
2120 trace_ext4_ext_put_in_cache(inode, block, len, start);
2121 cex = &EXT4_I(inode)->i_cached_extent;
2122 cex->ec_block = block;
2124 cex->ec_start = start;
2125 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
2129 * ext4_ext_put_gap_in_cache:
2130 * calculate boundaries of the gap that the requested block fits into
2131 * and cache this gap
2134 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2137 int depth = ext_depth(inode);
2140 struct ext4_extent *ex;
2142 ex = path[depth].p_ext;
2144 /* there is no extent yet, so gap is [0;-] */
2146 len = EXT_MAX_BLOCKS;
2147 ext_debug("cache gap(whole file):");
2148 } else if (block < le32_to_cpu(ex->ee_block)) {
2150 len = le32_to_cpu(ex->ee_block) - block;
2151 ext_debug("cache gap(before): %u [%u:%u]",
2153 le32_to_cpu(ex->ee_block),
2154 ext4_ext_get_actual_len(ex));
2155 } else if (block >= le32_to_cpu(ex->ee_block)
2156 + ext4_ext_get_actual_len(ex)) {
2158 lblock = le32_to_cpu(ex->ee_block)
2159 + ext4_ext_get_actual_len(ex);
2161 next = ext4_ext_next_allocated_block(path);
2162 ext_debug("cache gap(after): [%u:%u] %u",
2163 le32_to_cpu(ex->ee_block),
2164 ext4_ext_get_actual_len(ex),
2166 BUG_ON(next == lblock);
2167 len = next - lblock;
2173 ext_debug(" -> %u:%lu\n", lblock, len);
2174 ext4_ext_put_in_cache(inode, lblock, len, 0);
2178 * ext4_ext_in_cache()
2179 * Checks to see if the given block is in the cache.
2180 * If it is, the cached extent is stored in the given
2181 * cache extent pointer.
2183 * @inode: The files inode
2184 * @block: The block to look for in the cache
2185 * @ex: Pointer where the cached extent will be stored
2186 * if it contains block
2188 * Return 0 if cache is invalid; 1 if the cache is valid
2191 ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
2192 struct ext4_extent *ex)
2194 struct ext4_ext_cache *cex;
2195 struct ext4_sb_info *sbi;
2199 * We borrow i_block_reservation_lock to protect i_cached_extent
2201 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
2202 cex = &EXT4_I(inode)->i_cached_extent;
2203 sbi = EXT4_SB(inode->i_sb);
2205 /* has cache valid data? */
2206 if (cex->ec_len == 0)
2209 if (in_range(block, cex->ec_block, cex->ec_len)) {
2210 ex->ee_block = cpu_to_le32(cex->ec_block);
2211 ext4_ext_store_pblock(ex, cex->ec_start);
2212 ex->ee_len = cpu_to_le16(cex->ec_len);
2213 ext_debug("%u cached by %u:%u:%llu\n",
2215 cex->ec_block, cex->ec_len, cex->ec_start);
2219 trace_ext4_ext_in_cache(inode, block, ret);
2220 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
2226 * removes index from the index block.
2228 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2229 struct ext4_ext_path *path)
2234 /* free index block */
2236 leaf = ext4_idx_pblock(path->p_idx);
2237 if (unlikely(path->p_hdr->eh_entries == 0)) {
2238 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2241 err = ext4_ext_get_access(handle, inode, path);
2245 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2246 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2247 len *= sizeof(struct ext4_extent_idx);
2248 memmove(path->p_idx, path->p_idx + 1, len);
2251 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2252 err = ext4_ext_dirty(handle, inode, path);
2255 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2256 trace_ext4_ext_rm_idx(inode, leaf);
2258 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2259 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2264 * ext4_ext_calc_credits_for_single_extent:
2265 * This routine returns max. credits that needed to insert an extent
2266 * to the extent tree.
2267 * When pass the actual path, the caller should calculate credits
2270 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2271 struct ext4_ext_path *path)
2274 int depth = ext_depth(inode);
2277 /* probably there is space in leaf? */
2278 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2279 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2282 * There are some space in the leaf tree, no
2283 * need to account for leaf block credit
2285 * bitmaps and block group descriptor blocks
2286 * and other metadata blocks still need to be
2289 /* 1 bitmap, 1 block group descriptor */
2290 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2295 return ext4_chunk_trans_blocks(inode, nrblocks);
2299 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2301 * if nrblocks are fit in a single extent (chunk flag is 1), then
2302 * in the worse case, each tree level index/leaf need to be changed
2303 * if the tree split due to insert a new extent, then the old tree
2304 * index/leaf need to be updated too
2306 * If the nrblocks are discontiguous, they could cause
2307 * the whole tree split more than once, but this is really rare.
2309 int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
2312 int depth = ext_depth(inode);
2322 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2323 struct ext4_extent *ex,
2324 ext4_fsblk_t *partial_cluster,
2325 ext4_lblk_t from, ext4_lblk_t to)
2327 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2328 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2332 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2333 flags |= EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2334 else if (ext4_should_journal_data(inode))
2335 flags |= EXT4_FREE_BLOCKS_FORGET;
2338 * For bigalloc file systems, we never free a partial cluster
2339 * at the beginning of the extent. Instead, we make a note
2340 * that we tried freeing the cluster, and check to see if we
2341 * need to free it on a subsequent call to ext4_remove_blocks,
2342 * or at the end of the ext4_truncate() operation.
2344 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2346 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2348 * If we have a partial cluster, and it's different from the
2349 * cluster of the last block, we need to explicitly free the
2350 * partial cluster here.
2352 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2353 if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
2354 ext4_free_blocks(handle, inode, NULL,
2355 EXT4_C2B(sbi, *partial_cluster),
2356 sbi->s_cluster_ratio, flags);
2357 *partial_cluster = 0;
2360 #ifdef EXTENTS_STATS
2362 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2363 spin_lock(&sbi->s_ext_stats_lock);
2364 sbi->s_ext_blocks += ee_len;
2365 sbi->s_ext_extents++;
2366 if (ee_len < sbi->s_ext_min)
2367 sbi->s_ext_min = ee_len;
2368 if (ee_len > sbi->s_ext_max)
2369 sbi->s_ext_max = ee_len;
2370 if (ext_depth(inode) > sbi->s_depth_max)
2371 sbi->s_depth_max = ext_depth(inode);
2372 spin_unlock(&sbi->s_ext_stats_lock);
2375 if (from >= le32_to_cpu(ex->ee_block)
2376 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2380 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2381 pblk = ext4_ext_pblock(ex) + ee_len - num;
2382 ext_debug("free last %u blocks starting %llu\n", num, pblk);
2383 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2385 * If the block range to be freed didn't start at the
2386 * beginning of a cluster, and we removed the entire
2387 * extent, save the partial cluster here, since we
2388 * might need to delete if we determine that the
2389 * truncate operation has removed all of the blocks in
2392 if (pblk & (sbi->s_cluster_ratio - 1) &&
2394 *partial_cluster = EXT4_B2C(sbi, pblk);
2396 *partial_cluster = 0;
2397 } else if (from == le32_to_cpu(ex->ee_block)
2398 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
2404 start = ext4_ext_pblock(ex);
2406 ext_debug("free first %u blocks starting %llu\n", num, start);
2407 ext4_free_blocks(handle, inode, NULL, start, num, flags);
2410 printk(KERN_INFO "strange request: removal(2) "
2411 "%u-%u from %u:%u\n",
2412 from, to, le32_to_cpu(ex->ee_block), ee_len);
2419 * ext4_ext_rm_leaf() Removes the extents associated with the
2420 * blocks appearing between "start" and "end", and splits the extents
2421 * if "start" and "end" appear in the same extent
2423 * @handle: The journal handle
2424 * @inode: The files inode
2425 * @path: The path to the leaf
2426 * @start: The first block to remove
2427 * @end: The last block to remove
2430 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2431 struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster,
2432 ext4_lblk_t start, ext4_lblk_t end)
2434 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2435 int err = 0, correct_index = 0;
2436 int depth = ext_depth(inode), credits;
2437 struct ext4_extent_header *eh;
2440 ext4_lblk_t ex_ee_block;
2441 unsigned short ex_ee_len;
2442 unsigned uninitialized = 0;
2443 struct ext4_extent *ex;
2445 /* the header must be checked already in ext4_ext_remove_space() */
2446 ext_debug("truncate since %u in leaf to %u\n", start, end);
2447 if (!path[depth].p_hdr)
2448 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2449 eh = path[depth].p_hdr;
2450 if (unlikely(path[depth].p_hdr == NULL)) {
2451 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2454 /* find where to start removing */
2455 ex = EXT_LAST_EXTENT(eh);
2457 ex_ee_block = le32_to_cpu(ex->ee_block);
2458 ex_ee_len = ext4_ext_get_actual_len(ex);
2460 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2462 while (ex >= EXT_FIRST_EXTENT(eh) &&
2463 ex_ee_block + ex_ee_len > start) {
2465 if (ext4_ext_is_uninitialized(ex))
2470 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2471 uninitialized, ex_ee_len);
2472 path[depth].p_ext = ex;
2474 a = ex_ee_block > start ? ex_ee_block : start;
2475 b = ex_ee_block+ex_ee_len - 1 < end ?
2476 ex_ee_block+ex_ee_len - 1 : end;
2478 ext_debug(" border %u:%u\n", a, b);
2480 /* If this extent is beyond the end of the hole, skip it */
2481 if (end < ex_ee_block) {
2483 ex_ee_block = le32_to_cpu(ex->ee_block);
2484 ex_ee_len = ext4_ext_get_actual_len(ex);
2486 } else if (b != ex_ee_block + ex_ee_len - 1) {
2487 EXT4_ERROR_INODE(inode,
2488 "can not handle truncate %u:%u "
2490 start, end, ex_ee_block,
2491 ex_ee_block + ex_ee_len - 1);
2494 } else if (a != ex_ee_block) {
2495 /* remove tail of the extent */
2496 num = a - ex_ee_block;
2498 /* remove whole extent: excellent! */
2502 * 3 for leaf, sb, and inode plus 2 (bmap and group
2503 * descriptor) for each block group; assume two block
2504 * groups plus ex_ee_len/blocks_per_block_group for
2507 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2508 if (ex == EXT_FIRST_EXTENT(eh)) {
2510 credits += (ext_depth(inode)) + 1;
2512 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2514 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2518 err = ext4_ext_get_access(handle, inode, path + depth);
2522 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2528 /* this extent is removed; mark slot entirely unused */
2529 ext4_ext_store_pblock(ex, 0);
2531 ex->ee_len = cpu_to_le16(num);
2533 * Do not mark uninitialized if all the blocks in the
2534 * extent have been removed.
2536 if (uninitialized && num)
2537 ext4_ext_mark_uninitialized(ex);
2539 * If the extent was completely released,
2540 * we need to remove it from the leaf
2543 if (end != EXT_MAX_BLOCKS - 1) {
2545 * For hole punching, we need to scoot all the
2546 * extents up when an extent is removed so that
2547 * we dont have blank extents in the middle
2549 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2550 sizeof(struct ext4_extent));
2552 /* Now get rid of the one at the end */
2553 memset(EXT_LAST_EXTENT(eh), 0,
2554 sizeof(struct ext4_extent));
2556 le16_add_cpu(&eh->eh_entries, -1);
2558 *partial_cluster = 0;
2560 err = ext4_ext_dirty(handle, inode, path + depth);
2564 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2565 ext4_ext_pblock(ex));
2567 ex_ee_block = le32_to_cpu(ex->ee_block);
2568 ex_ee_len = ext4_ext_get_actual_len(ex);
2571 if (correct_index && eh->eh_entries)
2572 err = ext4_ext_correct_indexes(handle, inode, path);
2575 * If there is still a entry in the leaf node, check to see if
2576 * it references the partial cluster. This is the only place
2577 * where it could; if it doesn't, we can free the cluster.
2579 if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) &&
2580 (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
2581 *partial_cluster)) {
2582 int flags = EXT4_FREE_BLOCKS_FORGET;
2584 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2585 flags |= EXT4_FREE_BLOCKS_METADATA;
2587 ext4_free_blocks(handle, inode, NULL,
2588 EXT4_C2B(sbi, *partial_cluster),
2589 sbi->s_cluster_ratio, flags);
2590 *partial_cluster = 0;
2593 /* if this leaf is free, then we should
2594 * remove it from index block above */
2595 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2596 err = ext4_ext_rm_idx(handle, inode, path + depth);
2603 * ext4_ext_more_to_rm:
2604 * returns 1 if current index has to be freed (even partial)
2607 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2609 BUG_ON(path->p_idx == NULL);
2611 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2615 * if truncate on deeper level happened, it wasn't partial,
2616 * so we have to consider current index for truncation
2618 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2623 static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2626 struct super_block *sb = inode->i_sb;
2627 int depth = ext_depth(inode);
2628 struct ext4_ext_path *path = NULL;
2629 ext4_fsblk_t partial_cluster = 0;
2633 ext_debug("truncate since %u to %u\n", start, end);
2635 /* probably first extent we're gonna free will be last in block */
2636 handle = ext4_journal_start(inode, depth + 1);
2638 return PTR_ERR(handle);
2641 ext4_ext_invalidate_cache(inode);
2643 trace_ext4_ext_remove_space(inode, start, depth);
2646 * Check if we are removing extents inside the extent tree. If that
2647 * is the case, we are going to punch a hole inside the extent tree
2648 * so we have to check whether we need to split the extent covering
2649 * the last block to remove so we can easily remove the part of it
2650 * in ext4_ext_rm_leaf().
2652 if (end < EXT_MAX_BLOCKS - 1) {
2653 struct ext4_extent *ex;
2654 ext4_lblk_t ee_block;
2656 /* find extent for this block */
2657 path = ext4_ext_find_extent(inode, end, NULL);
2659 ext4_journal_stop(handle);
2660 return PTR_ERR(path);
2662 depth = ext_depth(inode);
2663 /* Leaf not may not exist only if inode has no blocks at all */
2664 ex = path[depth].p_ext;
2667 EXT4_ERROR_INODE(inode,
2668 "path[%d].p_hdr == NULL",
2675 ee_block = le32_to_cpu(ex->ee_block);
2678 * See if the last block is inside the extent, if so split
2679 * the extent at 'end' block so we can easily remove the
2680 * tail of the first part of the split extent in
2681 * ext4_ext_rm_leaf().
2683 if (end >= ee_block &&
2684 end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
2687 if (ext4_ext_is_uninitialized(ex))
2688 split_flag = EXT4_EXT_MARK_UNINIT1 |
2689 EXT4_EXT_MARK_UNINIT2;
2692 * Split the extent in two so that 'end' is the last
2693 * block in the first new extent
2695 err = ext4_split_extent_at(handle, inode, path,
2696 end + 1, split_flag,
2697 EXT4_GET_BLOCKS_PRE_IO |
2698 EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
2705 * We start scanning from right side, freeing all the blocks
2706 * after i_size and walking into the tree depth-wise.
2708 depth = ext_depth(inode);
2713 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2715 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2718 ext4_journal_stop(handle);
2721 path[0].p_depth = depth;
2722 path[0].p_hdr = ext_inode_hdr(inode);
2725 if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
2732 while (i >= 0 && err == 0) {
2734 /* this is leaf block */
2735 err = ext4_ext_rm_leaf(handle, inode, path,
2736 &partial_cluster, start,
2738 /* root level has p_bh == NULL, brelse() eats this */
2739 brelse(path[i].p_bh);
2740 path[i].p_bh = NULL;
2745 /* this is index block */
2746 if (!path[i].p_hdr) {
2747 ext_debug("initialize header\n");
2748 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2751 if (!path[i].p_idx) {
2752 /* this level hasn't been touched yet */
2753 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2754 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2755 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2757 le16_to_cpu(path[i].p_hdr->eh_entries));
2759 /* we were already here, see at next index */
2763 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2764 i, EXT_FIRST_INDEX(path[i].p_hdr),
2766 if (ext4_ext_more_to_rm(path + i)) {
2767 struct buffer_head *bh;
2768 /* go to the next level */
2769 ext_debug("move to level %d (block %llu)\n",
2770 i + 1, ext4_idx_pblock(path[i].p_idx));
2771 memset(path + i + 1, 0, sizeof(*path));
2772 bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
2774 /* should we reset i_size? */
2778 if (WARN_ON(i + 1 > depth)) {
2782 if (ext4_ext_check_block(inode, ext_block_hdr(bh),
2783 depth - i - 1, bh)) {
2787 path[i + 1].p_bh = bh;
2789 /* save actual number of indexes since this
2790 * number is changed at the next iteration */
2791 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2794 /* we finished processing this index, go up */
2795 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2796 /* index is empty, remove it;
2797 * handle must be already prepared by the
2798 * truncatei_leaf() */
2799 err = ext4_ext_rm_idx(handle, inode, path + i);
2801 /* root level has p_bh == NULL, brelse() eats this */
2802 brelse(path[i].p_bh);
2803 path[i].p_bh = NULL;
2805 ext_debug("return to level %d\n", i);
2809 trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster,
2810 path->p_hdr->eh_entries);
2812 /* If we still have something in the partial cluster and we have removed
2813 * even the first extent, then we should free the blocks in the partial
2814 * cluster as well. */
2815 if (partial_cluster && path->p_hdr->eh_entries == 0) {
2816 int flags = EXT4_FREE_BLOCKS_FORGET;
2818 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2819 flags |= EXT4_FREE_BLOCKS_METADATA;
2821 ext4_free_blocks(handle, inode, NULL,
2822 EXT4_C2B(EXT4_SB(sb), partial_cluster),
2823 EXT4_SB(sb)->s_cluster_ratio, flags);
2824 partial_cluster = 0;
2827 /* TODO: flexible tree reduction should be here */
2828 if (path->p_hdr->eh_entries == 0) {
2830 * truncate to zero freed all the tree,
2831 * so we need to correct eh_depth
2833 err = ext4_ext_get_access(handle, inode, path);
2835 ext_inode_hdr(inode)->eh_depth = 0;
2836 ext_inode_hdr(inode)->eh_max =
2837 cpu_to_le16(ext4_ext_space_root(inode, 0));
2838 err = ext4_ext_dirty(handle, inode, path);
2842 ext4_ext_drop_refs(path);
2844 if (err == -EAGAIN) {
2848 ext4_journal_stop(handle);
2854 * called at mount time
2856 void ext4_ext_init(struct super_block *sb)
2859 * possible initialization would be here
2862 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2863 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2864 printk(KERN_INFO "EXT4-fs: file extents enabled"
2865 #ifdef AGGRESSIVE_TEST
2866 ", aggressive tests"
2868 #ifdef CHECK_BINSEARCH
2871 #ifdef EXTENTS_STATS
2876 #ifdef EXTENTS_STATS
2877 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2878 EXT4_SB(sb)->s_ext_min = 1 << 30;
2879 EXT4_SB(sb)->s_ext_max = 0;
2885 * called at umount time
2887 void ext4_ext_release(struct super_block *sb)
2889 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
2892 #ifdef EXTENTS_STATS
2893 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2894 struct ext4_sb_info *sbi = EXT4_SB(sb);
2895 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2896 sbi->s_ext_blocks, sbi->s_ext_extents,
2897 sbi->s_ext_blocks / sbi->s_ext_extents);
2898 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2899 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2904 /* FIXME!! we need to try to merge to left or right after zero-out */
2905 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2907 ext4_fsblk_t ee_pblock;
2908 unsigned int ee_len;
2911 ee_len = ext4_ext_get_actual_len(ex);
2912 ee_pblock = ext4_ext_pblock(ex);
2914 ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
2922 * ext4_split_extent_at() splits an extent at given block.
2924 * @handle: the journal handle
2925 * @inode: the file inode
2926 * @path: the path to the extent
2927 * @split: the logical block where the extent is splitted.
2928 * @split_flags: indicates if the extent could be zeroout if split fails, and
2929 * the states(init or uninit) of new extents.
2930 * @flags: flags used to insert new extent to extent tree.
2933 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
2934 * of which are deterimined by split_flag.
2936 * There are two cases:
2937 * a> the extent are splitted into two extent.
2938 * b> split is not needed, and just mark the extent.
2940 * return 0 on success.
2942 static int ext4_split_extent_at(handle_t *handle,
2943 struct inode *inode,
2944 struct ext4_ext_path *path,
2949 ext4_fsblk_t newblock;
2950 ext4_lblk_t ee_block;
2951 struct ext4_extent *ex, newex, orig_ex;
2952 struct ext4_extent *ex2 = NULL;
2953 unsigned int ee_len, depth;
2956 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
2957 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
2959 ext_debug("ext4_split_extents_at: inode %lu, logical"
2960 "block %llu\n", inode->i_ino, (unsigned long long)split);
2962 ext4_ext_show_leaf(inode, path);
2964 depth = ext_depth(inode);
2965 ex = path[depth].p_ext;
2966 ee_block = le32_to_cpu(ex->ee_block);
2967 ee_len = ext4_ext_get_actual_len(ex);
2968 newblock = split - ee_block + ext4_ext_pblock(ex);
2970 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
2972 err = ext4_ext_get_access(handle, inode, path + depth);
2976 if (split == ee_block) {
2978 * case b: block @split is the block that the extent begins with
2979 * then we just change the state of the extent, and splitting
2982 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2983 ext4_ext_mark_uninitialized(ex);
2985 ext4_ext_mark_initialized(ex);
2987 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
2988 ext4_ext_try_to_merge(handle, inode, path, ex);
2990 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2995 memcpy(&orig_ex, ex, sizeof(orig_ex));
2996 ex->ee_len = cpu_to_le16(split - ee_block);
2997 if (split_flag & EXT4_EXT_MARK_UNINIT1)
2998 ext4_ext_mark_uninitialized(ex);
3001 * path may lead to new leaf, not to original leaf any more
3002 * after ext4_ext_insert_extent() returns,
3004 err = ext4_ext_dirty(handle, inode, path + depth);
3006 goto fix_extent_len;
3009 ex2->ee_block = cpu_to_le32(split);
3010 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3011 ext4_ext_store_pblock(ex2, newblock);
3012 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3013 ext4_ext_mark_uninitialized(ex2);
3015 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
3016 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3017 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3018 if (split_flag & EXT4_EXT_DATA_VALID1)
3019 err = ext4_ext_zeroout(inode, ex2);
3021 err = ext4_ext_zeroout(inode, ex);
3023 err = ext4_ext_zeroout(inode, &orig_ex);
3026 goto fix_extent_len;
3027 /* update the extent length and mark as initialized */
3028 ex->ee_len = cpu_to_le16(ee_len);
3029 ext4_ext_try_to_merge(handle, inode, path, ex);
3030 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3033 goto fix_extent_len;
3036 ext4_ext_show_leaf(inode, path);
3040 ex->ee_len = orig_ex.ee_len;
3041 ext4_ext_dirty(handle, inode, path + depth);
3046 * ext4_split_extents() splits an extent and mark extent which is covered
3047 * by @map as split_flags indicates
3049 * It may result in splitting the extent into multiple extents (upto three)
3050 * There are three possibilities:
3051 * a> There is no split required
3052 * b> Splits in two extents: Split is happening at either end of the extent
3053 * c> Splits in three extents: Somone is splitting in middle of the extent
3056 static int ext4_split_extent(handle_t *handle,
3057 struct inode *inode,
3058 struct ext4_ext_path *path,
3059 struct ext4_map_blocks *map,
3063 ext4_lblk_t ee_block;
3064 struct ext4_extent *ex;
3065 unsigned int ee_len, depth;
3068 int split_flag1, flags1;
3070 depth = ext_depth(inode);
3071 ex = path[depth].p_ext;
3072 ee_block = le32_to_cpu(ex->ee_block);
3073 ee_len = ext4_ext_get_actual_len(ex);
3074 uninitialized = ext4_ext_is_uninitialized(ex);
3076 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3077 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3078 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3080 split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
3081 EXT4_EXT_MARK_UNINIT2;
3082 if (split_flag & EXT4_EXT_DATA_VALID2)
3083 split_flag1 |= EXT4_EXT_DATA_VALID1;
3084 err = ext4_split_extent_at(handle, inode, path,
3085 map->m_lblk + map->m_len, split_flag1, flags1);
3090 ext4_ext_drop_refs(path);
3091 path = ext4_ext_find_extent(inode, map->m_lblk, path);
3093 return PTR_ERR(path);
3095 if (map->m_lblk >= ee_block) {
3096 split_flag1 = split_flag & (EXT4_EXT_MAY_ZEROOUT |
3097 EXT4_EXT_DATA_VALID2);
3099 split_flag1 |= EXT4_EXT_MARK_UNINIT1;
3100 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3101 split_flag1 |= EXT4_EXT_MARK_UNINIT2;
3102 err = ext4_split_extent_at(handle, inode, path,
3103 map->m_lblk, split_flag1, flags);
3108 ext4_ext_show_leaf(inode, path);
3110 return err ? err : map->m_len;
3114 * This function is called by ext4_ext_map_blocks() if someone tries to write
3115 * to an uninitialized extent. It may result in splitting the uninitialized
3116 * extent into multiple extents (up to three - one initialized and two
3118 * There are three possibilities:
3119 * a> There is no split required: Entire extent should be initialized
3120 * b> Splits in two extents: Write is happening at either end of the extent
3121 * c> Splits in three extents: Somone is writing in middle of the extent
3124 * - The extent pointed to by 'path' is uninitialized.
3125 * - The extent pointed to by 'path' contains a superset
3126 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3128 * Post-conditions on success:
3129 * - the returned value is the number of blocks beyond map->l_lblk
3130 * that are allocated and initialized.
3131 * It is guaranteed to be >= map->m_len.
3133 static int ext4_ext_convert_to_initialized(handle_t *handle,
3134 struct inode *inode,
3135 struct ext4_map_blocks *map,
3136 struct ext4_ext_path *path)
3138 struct ext4_sb_info *sbi;
3139 struct ext4_extent_header *eh;
3140 struct ext4_map_blocks split_map;
3141 struct ext4_extent zero_ex;
3142 struct ext4_extent *ex;
3143 ext4_lblk_t ee_block, eof_block;
3144 unsigned int ee_len, depth;
3145 int allocated, max_zeroout = 0;
3149 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3150 "block %llu, max_blocks %u\n", inode->i_ino,
3151 (unsigned long long)map->m_lblk, map->m_len);
3153 sbi = EXT4_SB(inode->i_sb);
3154 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3155 inode->i_sb->s_blocksize_bits;
3156 if (eof_block < map->m_lblk + map->m_len)
3157 eof_block = map->m_lblk + map->m_len;
3159 depth = ext_depth(inode);
3160 eh = path[depth].p_hdr;
3161 ex = path[depth].p_ext;
3162 ee_block = le32_to_cpu(ex->ee_block);
3163 ee_len = ext4_ext_get_actual_len(ex);
3164 allocated = ee_len - (map->m_lblk - ee_block);
3166 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3168 /* Pre-conditions */
3169 BUG_ON(!ext4_ext_is_uninitialized(ex));
3170 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3173 * Attempt to transfer newly initialized blocks from the currently
3174 * uninitialized extent to its left neighbor. This is much cheaper
3175 * than an insertion followed by a merge as those involve costly
3176 * memmove() calls. This is the common case in steady state for
3177 * workloads doing fallocate(FALLOC_FL_KEEP_SIZE) followed by append
3180 * Limitations of the current logic:
3181 * - L1: we only deal with writes at the start of the extent.
3182 * The approach could be extended to writes at the end
3183 * of the extent but this scenario was deemed less common.
3184 * - L2: we do not deal with writes covering the whole extent.
3185 * This would require removing the extent if the transfer
3187 * - L3: we only attempt to merge with an extent stored in the
3188 * same extent tree node.
3190 if ((map->m_lblk == ee_block) && /*L1*/
3191 (map->m_len < ee_len) && /*L2*/
3192 (ex > EXT_FIRST_EXTENT(eh))) { /*L3*/
3193 struct ext4_extent *prev_ex;
3194 ext4_lblk_t prev_lblk;
3195 ext4_fsblk_t prev_pblk, ee_pblk;
3196 unsigned int prev_len, write_len;
3199 prev_lblk = le32_to_cpu(prev_ex->ee_block);
3200 prev_len = ext4_ext_get_actual_len(prev_ex);
3201 prev_pblk = ext4_ext_pblock(prev_ex);
3202 ee_pblk = ext4_ext_pblock(ex);
3203 write_len = map->m_len;
3206 * A transfer of blocks from 'ex' to 'prev_ex' is allowed
3207 * upon those conditions:
3208 * - C1: prev_ex is initialized,
3209 * - C2: prev_ex is logically abutting ex,
3210 * - C3: prev_ex is physically abutting ex,
3211 * - C4: prev_ex can receive the additional blocks without
3212 * overflowing the (initialized) length limit.
3214 if ((!ext4_ext_is_uninitialized(prev_ex)) && /*C1*/
3215 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3216 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3217 (prev_len < (EXT_INIT_MAX_LEN - write_len))) { /*C4*/
3218 err = ext4_ext_get_access(handle, inode, path + depth);
3222 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3225 /* Shift the start of ex by 'write_len' blocks */
3226 ex->ee_block = cpu_to_le32(ee_block + write_len);
3227 ext4_ext_store_pblock(ex, ee_pblk + write_len);
3228 ex->ee_len = cpu_to_le16(ee_len - write_len);
3229 ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3231 /* Extend prev_ex by 'write_len' blocks */
3232 prev_ex->ee_len = cpu_to_le16(prev_len + write_len);
3234 /* Mark the block containing both extents as dirty */
3235 ext4_ext_dirty(handle, inode, path + depth);
3237 /* Update path to point to the right extent */
3238 path[depth].p_ext = prev_ex;
3240 /* Result: number of initialized blocks past m_lblk */
3241 allocated = write_len;
3246 WARN_ON(map->m_lblk < ee_block);
3248 * It is safe to convert extent to initialized via explicit
3249 * zeroout only if extent is fully insde i_size or new_size.
3251 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3253 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3254 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3255 inode->i_sb->s_blocksize_bits;
3257 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3258 if (max_zeroout && (ee_len <= max_zeroout)) {
3259 err = ext4_ext_zeroout(inode, ex);
3263 err = ext4_ext_get_access(handle, inode, path + depth);
3266 ext4_ext_mark_initialized(ex);
3267 ext4_ext_try_to_merge(handle, inode, path, ex);
3268 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3274 * 1. split the extent into three extents.
3275 * 2. split the extent into two extents, zeroout the first half.
3276 * 3. split the extent into two extents, zeroout the second half.
3277 * 4. split the extent into two extents with out zeroout.
3279 split_map.m_lblk = map->m_lblk;
3280 split_map.m_len = map->m_len;
3282 if (max_zeroout && (allocated > map->m_len)) {
3283 if (allocated <= max_zeroout) {
3286 cpu_to_le32(map->m_lblk);
3287 zero_ex.ee_len = cpu_to_le16(allocated);
3288 ext4_ext_store_pblock(&zero_ex,
3289 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3290 err = ext4_ext_zeroout(inode, &zero_ex);
3293 split_map.m_lblk = map->m_lblk;
3294 split_map.m_len = allocated;
3295 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3297 if (map->m_lblk != ee_block) {
3298 zero_ex.ee_block = ex->ee_block;
3299 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3301 ext4_ext_store_pblock(&zero_ex,
3302 ext4_ext_pblock(ex));
3303 err = ext4_ext_zeroout(inode, &zero_ex);
3308 split_map.m_lblk = ee_block;
3309 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3310 allocated = map->m_len;
3314 allocated = ext4_split_extent(handle, inode, path,
3315 &split_map, split_flag, 0);
3320 return err ? err : allocated;
3324 * This function is called by ext4_ext_map_blocks() from
3325 * ext4_get_blocks_dio_write() when DIO to write
3326 * to an uninitialized extent.
3328 * Writing to an uninitialized extent may result in splitting the uninitialized
3329 * extent into multiple initialized/uninitialized extents (up to three)
3330 * There are three possibilities:
3331 * a> There is no split required: Entire extent should be uninitialized
3332 * b> Splits in two extents: Write is happening at either end of the extent
3333 * c> Splits in three extents: Somone is writing in middle of the extent
3335 * One of more index blocks maybe needed if the extent tree grow after
3336 * the uninitialized extent split. To prevent ENOSPC occur at the IO
3337 * complete, we need to split the uninitialized extent before DIO submit
3338 * the IO. The uninitialized extent called at this time will be split
3339 * into three uninitialized extent(at most). After IO complete, the part
3340 * being filled will be convert to initialized by the end_io callback function
3341 * via ext4_convert_unwritten_extents().
3343 * Returns the size of uninitialized extent to be written on success.
3345 static int ext4_split_unwritten_extents(handle_t *handle,
3346 struct inode *inode,
3347 struct ext4_map_blocks *map,
3348 struct ext4_ext_path *path,
3351 ext4_lblk_t eof_block;
3352 ext4_lblk_t ee_block;
3353 struct ext4_extent *ex;
3354 unsigned int ee_len;
3355 int split_flag = 0, depth;
3357 ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3358 "block %llu, max_blocks %u\n", inode->i_ino,
3359 (unsigned long long)map->m_lblk, map->m_len);
3361 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3362 inode->i_sb->s_blocksize_bits;
3363 if (eof_block < map->m_lblk + map->m_len)
3364 eof_block = map->m_lblk + map->m_len;
3366 * It is safe to convert extent to initialized via explicit
3367 * zeroout only if extent is fully insde i_size or new_size.
3369 depth = ext_depth(inode);
3370 ex = path[depth].p_ext;
3371 ee_block = le32_to_cpu(ex->ee_block);
3372 ee_len = ext4_ext_get_actual_len(ex);
3374 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3375 split_flag |= EXT4_EXT_MARK_UNINIT2;
3376 if (flags & EXT4_GET_BLOCKS_CONVERT)
3377 split_flag |= EXT4_EXT_DATA_VALID2;
3378 flags |= EXT4_GET_BLOCKS_PRE_IO;
3379 return ext4_split_extent(handle, inode, path, map, split_flag, flags);
3382 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3383 struct inode *inode,
3384 struct ext4_map_blocks *map,
3385 struct ext4_ext_path *path)
3387 struct ext4_extent *ex;
3388 ext4_lblk_t ee_block;
3389 unsigned int ee_len;
3393 depth = ext_depth(inode);
3394 ex = path[depth].p_ext;
3395 ee_block = le32_to_cpu(ex->ee_block);
3396 ee_len = ext4_ext_get_actual_len(ex);
3398 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3399 "block %llu, max_blocks %u\n", inode->i_ino,
3400 (unsigned long long)ee_block, ee_len);
3402 /* If extent is larger than requested then split is required */
3403 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3404 err = ext4_split_unwritten_extents(handle, inode, map, path,
3405 EXT4_GET_BLOCKS_CONVERT);
3408 ext4_ext_drop_refs(path);
3409 path = ext4_ext_find_extent(inode, map->m_lblk, path);
3411 err = PTR_ERR(path);
3414 depth = ext_depth(inode);
3415 ex = path[depth].p_ext;
3418 err = ext4_ext_get_access(handle, inode, path + depth);
3421 /* first mark the extent as initialized */
3422 ext4_ext_mark_initialized(ex);
3424 /* note: ext4_ext_correct_indexes() isn't needed here because
3425 * borders are not changed
3427 ext4_ext_try_to_merge(handle, inode, path, ex);
3429 /* Mark modified extent as dirty */
3430 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3432 ext4_ext_show_leaf(inode, path);
3436 static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3437 sector_t block, int count)
3440 for (i = 0; i < count; i++)
3441 unmap_underlying_metadata(bdev, block + i);
3445 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3447 static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3449 struct ext4_ext_path *path,
3453 struct ext4_extent_header *eh;
3454 struct ext4_extent *last_ex;
3456 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3459 depth = ext_depth(inode);
3460 eh = path[depth].p_hdr;
3463 * We're going to remove EOFBLOCKS_FL entirely in future so we
3464 * do not care for this case anymore. Simply remove the flag
3465 * if there are no extents.
3467 if (unlikely(!eh->eh_entries))
3469 last_ex = EXT_LAST_EXTENT(eh);
3471 * We should clear the EOFBLOCKS_FL flag if we are writing the
3472 * last block in the last extent in the file. We test this by
3473 * first checking to see if the caller to
3474 * ext4_ext_get_blocks() was interested in the last block (or
3475 * a block beyond the last block) in the current extent. If
3476 * this turns out to be false, we can bail out from this
3477 * function immediately.
3479 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3480 ext4_ext_get_actual_len(last_ex))
3483 * If the caller does appear to be planning to write at or
3484 * beyond the end of the current extent, we then test to see
3485 * if the current extent is the last extent in the file, by
3486 * checking to make sure it was reached via the rightmost node
3487 * at each level of the tree.
3489 for (i = depth-1; i >= 0; i--)
3490 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3493 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3494 return ext4_mark_inode_dirty(handle, inode);
3498 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3500 * Return 1 if there is a delalloc block in the range, otherwise 0.
3502 static int ext4_find_delalloc_range(struct inode *inode,
3503 ext4_lblk_t lblk_start,
3504 ext4_lblk_t lblk_end)
3506 struct extent_status es;
3508 es.start = lblk_start;
3509 ext4_es_find_extent(inode, &es);
3511 return 0; /* there is no delay extent in this tree */
3512 else if (es.start <= lblk_start && lblk_start < es.start + es.len)
3514 else if (lblk_start <= es.start && es.start <= lblk_end)
3520 int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3522 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3523 ext4_lblk_t lblk_start, lblk_end;
3524 lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
3525 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3527 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3531 * Determines how many complete clusters (out of those specified by the 'map')
3532 * are under delalloc and were reserved quota for.
3533 * This function is called when we are writing out the blocks that were
3534 * originally written with their allocation delayed, but then the space was
3535 * allocated using fallocate() before the delayed allocation could be resolved.
3536 * The cases to look for are:
3537 * ('=' indicated delayed allocated blocks
3538 * '-' indicates non-delayed allocated blocks)
3539 * (a) partial clusters towards beginning and/or end outside of allocated range
3540 * are not delalloc'ed.
3542 * |----c---=|====c====|====c====|===-c----|
3543 * |++++++ allocated ++++++|
3544 * ==> 4 complete clusters in above example
3546 * (b) partial cluster (outside of allocated range) towards either end is
3547 * marked for delayed allocation. In this case, we will exclude that
3550 * |----====c========|========c========|
3551 * |++++++ allocated ++++++|
3552 * ==> 1 complete clusters in above example
3555 * |================c================|
3556 * |++++++ allocated ++++++|
3557 * ==> 0 complete clusters in above example
3559 * The ext4_da_update_reserve_space will be called only if we
3560 * determine here that there were some "entire" clusters that span
3561 * this 'allocated' range.
3562 * In the non-bigalloc case, this function will just end up returning num_blks
3563 * without ever calling ext4_find_delalloc_range.
3566 get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3567 unsigned int num_blks)
3569 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3570 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3571 ext4_lblk_t lblk_from, lblk_to, c_offset;
3572 unsigned int allocated_clusters = 0;
3574 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3575 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3577 /* max possible clusters for this allocation */
3578 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3580 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3582 /* Check towards left side */
3583 c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
3585 lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
3586 lblk_to = lblk_from + c_offset - 1;
3588 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3589 allocated_clusters--;
3592 /* Now check towards right. */
3593 c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
3594 if (allocated_clusters && c_offset) {
3595 lblk_from = lblk_start + num_blks;
3596 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3598 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3599 allocated_clusters--;
3602 return allocated_clusters;
3606 ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3607 struct ext4_map_blocks *map,
3608 struct ext4_ext_path *path, int flags,
3609 unsigned int allocated, ext4_fsblk_t newblock)
3613 ext4_io_end_t *io = ext4_inode_aio(inode);
3615 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
3616 "block %llu, max_blocks %u, flags %x, allocated %u\n",
3617 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
3619 ext4_ext_show_leaf(inode, path);
3621 trace_ext4_ext_handle_uninitialized_extents(inode, map, flags,
3622 allocated, newblock);
3624 /* get_block() before submit the IO, split the extent */
3625 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3626 ret = ext4_split_unwritten_extents(handle, inode, map,
3631 * Flag the inode(non aio case) or end_io struct (aio case)
3632 * that this IO needs to conversion to written when IO is
3636 ext4_set_io_unwritten_flag(inode, io);
3638 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3639 if (ext4_should_dioread_nolock(inode))
3640 map->m_flags |= EXT4_MAP_UNINIT;
3643 /* IO end_io complete, convert the filled extent to written */
3644 if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
3645 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
3648 ext4_update_inode_fsync_trans(handle, inode, 1);
3649 err = check_eofblocks_fl(handle, inode, map->m_lblk,
3655 /* buffered IO case */
3657 * repeat fallocate creation request
3658 * we already have an unwritten extent
3660 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
3663 /* buffered READ or buffered write_begin() lookup */
3664 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3666 * We have blocks reserved already. We
3667 * return allocated blocks so that delalloc
3668 * won't do block reservation for us. But
3669 * the buffer head will be unmapped so that
3670 * a read from the block returns 0s.
3672 map->m_flags |= EXT4_MAP_UNWRITTEN;
3676 /* buffered write, writepage time, convert*/
3677 ret = ext4_ext_convert_to_initialized(handle, inode, map, path);
3679 ext4_update_inode_fsync_trans(handle, inode, 1);
3686 map->m_flags |= EXT4_MAP_NEW;
3688 * if we allocated more blocks than requested
3689 * we need to make sure we unmap the extra block
3690 * allocated. The actual needed block will get
3691 * unmapped later when we find the buffer_head marked
3694 if (allocated > map->m_len) {
3695 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
3696 newblock + map->m_len,
3697 allocated - map->m_len);
3698 allocated = map->m_len;
3702 * If we have done fallocate with the offset that is already
3703 * delayed allocated, we would have block reservation
3704 * and quota reservation done in the delayed write path.
3705 * But fallocate would have already updated quota and block
3706 * count for this offset. So cancel these reservation
3708 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
3709 unsigned int reserved_clusters;
3710 reserved_clusters = get_reserved_cluster_alloc(inode,
3711 map->m_lblk, map->m_len);
3712 if (reserved_clusters)
3713 ext4_da_update_reserve_space(inode,
3719 map->m_flags |= EXT4_MAP_MAPPED;
3720 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
3721 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
3727 if (allocated > map->m_len)
3728 allocated = map->m_len;
3729 ext4_ext_show_leaf(inode, path);
3730 map->m_pblk = newblock;
3731 map->m_len = allocated;
3734 ext4_ext_drop_refs(path);
3737 return err ? err : allocated;
3741 * get_implied_cluster_alloc - check to see if the requested
3742 * allocation (in the map structure) overlaps with a cluster already
3743 * allocated in an extent.
3744 * @sb The filesystem superblock structure
3745 * @map The requested lblk->pblk mapping
3746 * @ex The extent structure which might contain an implied
3747 * cluster allocation
3749 * This function is called by ext4_ext_map_blocks() after we failed to
3750 * find blocks that were already in the inode's extent tree. Hence,
3751 * we know that the beginning of the requested region cannot overlap
3752 * the extent from the inode's extent tree. There are three cases we
3753 * want to catch. The first is this case:
3755 * |--- cluster # N--|
3756 * |--- extent ---| |---- requested region ---|
3759 * The second case that we need to test for is this one:
3761 * |--------- cluster # N ----------------|
3762 * |--- requested region --| |------- extent ----|
3763 * |=======================|
3765 * The third case is when the requested region lies between two extents
3766 * within the same cluster:
3767 * |------------- cluster # N-------------|
3768 * |----- ex -----| |---- ex_right ----|
3769 * |------ requested region ------|
3770 * |================|
3772 * In each of the above cases, we need to set the map->m_pblk and
3773 * map->m_len so it corresponds to the return the extent labelled as
3774 * "|====|" from cluster #N, since it is already in use for data in
3775 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
3776 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
3777 * as a new "allocated" block region. Otherwise, we will return 0 and
3778 * ext4_ext_map_blocks() will then allocate one or more new clusters
3779 * by calling ext4_mb_new_blocks().
3781 static int get_implied_cluster_alloc(struct super_block *sb,
3782 struct ext4_map_blocks *map,
3783 struct ext4_extent *ex,
3784 struct ext4_ext_path *path)
3786 struct ext4_sb_info *sbi = EXT4_SB(sb);
3787 ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3788 ext4_lblk_t ex_cluster_start, ex_cluster_end;
3789 ext4_lblk_t rr_cluster_start;
3790 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3791 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3792 unsigned short ee_len = ext4_ext_get_actual_len(ex);
3794 /* The extent passed in that we are trying to match */
3795 ex_cluster_start = EXT4_B2C(sbi, ee_block);
3796 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
3798 /* The requested region passed into ext4_map_blocks() */
3799 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
3801 if ((rr_cluster_start == ex_cluster_end) ||
3802 (rr_cluster_start == ex_cluster_start)) {
3803 if (rr_cluster_start == ex_cluster_end)
3804 ee_start += ee_len - 1;
3805 map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) +
3807 map->m_len = min(map->m_len,
3808 (unsigned) sbi->s_cluster_ratio - c_offset);
3810 * Check for and handle this case:
3812 * |--------- cluster # N-------------|
3813 * |------- extent ----|
3814 * |--- requested region ---|
3818 if (map->m_lblk < ee_block)
3819 map->m_len = min(map->m_len, ee_block - map->m_lblk);
3822 * Check for the case where there is already another allocated
3823 * block to the right of 'ex' but before the end of the cluster.
3825 * |------------- cluster # N-------------|
3826 * |----- ex -----| |---- ex_right ----|
3827 * |------ requested region ------|
3828 * |================|
3830 if (map->m_lblk > ee_block) {
3831 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
3832 map->m_len = min(map->m_len, next - map->m_lblk);
3835 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
3839 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
3845 * Block allocation/map/preallocation routine for extents based files
3848 * Need to be called with
3849 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
3850 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
3852 * return > 0, number of of blocks already mapped/allocated
3853 * if create == 0 and these are pre-allocated blocks
3854 * buffer head is unmapped
3855 * otherwise blocks are mapped
3857 * return = 0, if plain look up failed (blocks have not been allocated)
3858 * buffer head is unmapped
3860 * return < 0, error case.
3862 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3863 struct ext4_map_blocks *map, int flags)
3865 struct ext4_ext_path *path = NULL;
3866 struct ext4_extent newex, *ex, *ex2;
3867 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3868 ext4_fsblk_t newblock = 0;
3869 int free_on_err = 0, err = 0, depth;
3870 unsigned int allocated = 0, offset = 0;
3871 unsigned int allocated_clusters = 0;
3872 struct ext4_allocation_request ar;
3873 ext4_io_end_t *io = ext4_inode_aio(inode);
3874 ext4_lblk_t cluster_offset;
3875 int set_unwritten = 0;
3877 ext_debug("blocks %u/%u requested for inode %lu\n",
3878 map->m_lblk, map->m_len, inode->i_ino);
3879 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
3881 /* check in cache */
3882 if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
3883 if (!newex.ee_start_lo && !newex.ee_start_hi) {
3884 if ((sbi->s_cluster_ratio > 1) &&
3885 ext4_find_delalloc_cluster(inode, map->m_lblk))
3886 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3888 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3890 * block isn't allocated yet and
3891 * user doesn't want to allocate it
3895 /* we should allocate requested block */
3897 /* block is already allocated */
3898 if (sbi->s_cluster_ratio > 1)
3899 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3900 newblock = map->m_lblk
3901 - le32_to_cpu(newex.ee_block)
3902 + ext4_ext_pblock(&newex);
3903 /* number of remaining blocks in the extent */
3904 allocated = ext4_ext_get_actual_len(&newex) -
3905 (map->m_lblk - le32_to_cpu(newex.ee_block));
3910 /* find extent for this block */
3911 path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
3913 err = PTR_ERR(path);
3918 depth = ext_depth(inode);
3921 * consistent leaf must not be empty;
3922 * this situation is possible, though, _during_ tree modification;
3923 * this is why assert can't be put in ext4_ext_find_extent()
3925 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
3926 EXT4_ERROR_INODE(inode, "bad extent address "
3927 "lblock: %lu, depth: %d pblock %lld",
3928 (unsigned long) map->m_lblk, depth,
3929 path[depth].p_block);
3934 ex = path[depth].p_ext;
3936 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3937 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3938 unsigned short ee_len;
3941 * Uninitialized extents are treated as holes, except that
3942 * we split out initialized portions during a write.
3944 ee_len = ext4_ext_get_actual_len(ex);
3946 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
3948 /* if found extent covers block, simply return it */
3949 if (in_range(map->m_lblk, ee_block, ee_len)) {
3950 newblock = map->m_lblk - ee_block + ee_start;
3951 /* number of remaining blocks in the extent */
3952 allocated = ee_len - (map->m_lblk - ee_block);
3953 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
3954 ee_block, ee_len, newblock);
3957 * Do not put uninitialized extent
3960 if (!ext4_ext_is_uninitialized(ex)) {
3961 ext4_ext_put_in_cache(inode, ee_block,
3965 allocated = ext4_ext_handle_uninitialized_extents(
3966 handle, inode, map, path, flags,
3967 allocated, newblock);
3972 if ((sbi->s_cluster_ratio > 1) &&
3973 ext4_find_delalloc_cluster(inode, map->m_lblk))
3974 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3977 * requested block isn't allocated yet;
3978 * we couldn't try to create block if create flag is zero
3980 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3982 * put just found gap into cache to speed up
3983 * subsequent requests
3985 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
3990 * Okay, we need to do block allocation.
3992 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
3993 newex.ee_block = cpu_to_le32(map->m_lblk);
3994 cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3997 * If we are doing bigalloc, check to see if the extent returned
3998 * by ext4_ext_find_extent() implies a cluster we can use.
4000 if (cluster_offset && ex &&
4001 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4002 ar.len = allocated = map->m_len;
4003 newblock = map->m_pblk;
4004 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4005 goto got_allocated_blocks;
4008 /* find neighbour allocated blocks */
4009 ar.lleft = map->m_lblk;
4010 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4013 ar.lright = map->m_lblk;
4015 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4019 /* Check if the extent after searching to the right implies a
4020 * cluster we can use. */
4021 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4022 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4023 ar.len = allocated = map->m_len;
4024 newblock = map->m_pblk;
4025 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4026 goto got_allocated_blocks;
4030 * See if request is beyond maximum number of blocks we can have in
4031 * a single extent. For an initialized extent this limit is
4032 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
4033 * EXT_UNINIT_MAX_LEN.
4035 if (map->m_len > EXT_INIT_MAX_LEN &&
4036 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4037 map->m_len = EXT_INIT_MAX_LEN;
4038 else if (map->m_len > EXT_UNINIT_MAX_LEN &&
4039 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4040 map->m_len = EXT_UNINIT_MAX_LEN;
4042 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4043 newex.ee_len = cpu_to_le16(map->m_len);
4044 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4046 allocated = ext4_ext_get_actual_len(&newex);
4048 allocated = map->m_len;
4050 /* allocate new block */
4052 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4053 ar.logical = map->m_lblk;
4055 * We calculate the offset from the beginning of the cluster
4056 * for the logical block number, since when we allocate a
4057 * physical cluster, the physical block should start at the
4058 * same offset from the beginning of the cluster. This is
4059 * needed so that future calls to get_implied_cluster_alloc()
4062 offset = map->m_lblk & (sbi->s_cluster_ratio - 1);
4063 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4065 ar.logical -= offset;
4066 if (S_ISREG(inode->i_mode))
4067 ar.flags = EXT4_MB_HINT_DATA;
4069 /* disable in-core preallocation for non-regular files */
4071 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4072 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4073 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4076 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4077 ar.goal, newblock, allocated);
4079 allocated_clusters = ar.len;
4080 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4081 if (ar.len > allocated)
4084 got_allocated_blocks:
4085 /* try to insert new extent into found leaf and return */
4086 ext4_ext_store_pblock(&newex, newblock + offset);
4087 newex.ee_len = cpu_to_le16(ar.len);
4088 /* Mark uninitialized */
4089 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
4090 ext4_ext_mark_uninitialized(&newex);
4092 * io_end structure was created for every IO write to an
4093 * uninitialized extent. To avoid unnecessary conversion,
4094 * here we flag the IO that really needs the conversion.
4095 * For non asycn direct IO case, flag the inode state
4096 * that we need to perform conversion when IO is done.
4098 if ((flags & EXT4_GET_BLOCKS_PRE_IO))
4100 if (ext4_should_dioread_nolock(inode))
4101 map->m_flags |= EXT4_MAP_UNINIT;
4105 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4106 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4109 err = ext4_ext_insert_extent(handle, inode, path,
4112 if (!err && set_unwritten) {
4114 ext4_set_io_unwritten_flag(inode, io);
4116 ext4_set_inode_state(inode,
4117 EXT4_STATE_DIO_UNWRITTEN);
4120 if (err && free_on_err) {
4121 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4122 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4123 /* free data blocks we just allocated */
4124 /* not a good idea to call discard here directly,
4125 * but otherwise we'd need to call it every free() */
4126 ext4_discard_preallocations(inode);
4127 ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex),
4128 ext4_ext_get_actual_len(&newex), fb_flags);
4132 /* previous routine could use block we allocated */
4133 newblock = ext4_ext_pblock(&newex);
4134 allocated = ext4_ext_get_actual_len(&newex);
4135 if (allocated > map->m_len)
4136 allocated = map->m_len;
4137 map->m_flags |= EXT4_MAP_NEW;
4140 * Update reserved blocks/metadata blocks after successful
4141 * block allocation which had been deferred till now.
4143 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4144 unsigned int reserved_clusters;
4146 * Check how many clusters we had reserved this allocated range
4148 reserved_clusters = get_reserved_cluster_alloc(inode,
4149 map->m_lblk, allocated);
4150 if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
4151 if (reserved_clusters) {
4153 * We have clusters reserved for this range.
4154 * But since we are not doing actual allocation
4155 * and are simply using blocks from previously
4156 * allocated cluster, we should release the
4157 * reservation and not claim quota.
4159 ext4_da_update_reserve_space(inode,
4160 reserved_clusters, 0);
4163 BUG_ON(allocated_clusters < reserved_clusters);
4164 /* We will claim quota for all newly allocated blocks.*/
4165 ext4_da_update_reserve_space(inode, allocated_clusters,
4167 if (reserved_clusters < allocated_clusters) {
4168 struct ext4_inode_info *ei = EXT4_I(inode);
4169 int reservation = allocated_clusters -
4172 * It seems we claimed few clusters outside of
4173 * the range of this allocation. We should give
4174 * it back to the reservation pool. This can
4175 * happen in the following case:
4177 * * Suppose s_cluster_ratio is 4 (i.e., each
4178 * cluster has 4 blocks. Thus, the clusters
4179 * are [0-3],[4-7],[8-11]...
4180 * * First comes delayed allocation write for
4181 * logical blocks 10 & 11. Since there were no
4182 * previous delayed allocated blocks in the
4183 * range [8-11], we would reserve 1 cluster
4185 * * Next comes write for logical blocks 3 to 8.
4186 * In this case, we will reserve 2 clusters
4187 * (for [0-3] and [4-7]; and not for [8-11] as
4188 * that range has a delayed allocated blocks.
4189 * Thus total reserved clusters now becomes 3.
4190 * * Now, during the delayed allocation writeout
4191 * time, we will first write blocks [3-8] and
4192 * allocate 3 clusters for writing these
4193 * blocks. Also, we would claim all these
4194 * three clusters above.
4195 * * Now when we come here to writeout the
4196 * blocks [10-11], we would expect to claim
4197 * the reservation of 1 cluster we had made
4198 * (and we would claim it since there are no
4199 * more delayed allocated blocks in the range
4200 * [8-11]. But our reserved cluster count had
4201 * already gone to 0.
4203 * Thus, at the step 4 above when we determine
4204 * that there are still some unwritten delayed
4205 * allocated blocks outside of our current
4206 * block range, we should increment the
4207 * reserved clusters count so that when the
4208 * remaining blocks finally gets written, we
4211 dquot_reserve_block(inode,
4212 EXT4_C2B(sbi, reservation));
4213 spin_lock(&ei->i_block_reservation_lock);
4214 ei->i_reserved_data_blocks += reservation;
4215 spin_unlock(&ei->i_block_reservation_lock);
4221 * Cache the extent and update transaction to commit on fdatasync only
4222 * when it is _not_ an uninitialized extent.
4224 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
4225 ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock);
4226 ext4_update_inode_fsync_trans(handle, inode, 1);
4228 ext4_update_inode_fsync_trans(handle, inode, 0);
4230 if (allocated > map->m_len)
4231 allocated = map->m_len;
4232 ext4_ext_show_leaf(inode, path);
4233 map->m_flags |= EXT4_MAP_MAPPED;
4234 map->m_pblk = newblock;
4235 map->m_len = allocated;
4238 ext4_ext_drop_refs(path);
4243 trace_ext4_ext_map_blocks_exit(inode, map, err ? err : allocated);
4245 return err ? err : allocated;
4248 void ext4_ext_truncate(struct inode *inode)
4250 struct address_space *mapping = inode->i_mapping;
4251 struct super_block *sb = inode->i_sb;
4252 ext4_lblk_t last_block;
4258 * finish any pending end_io work so we won't run the risk of
4259 * converting any truncated blocks to initialized later
4261 ext4_flush_unwritten_io(inode);
4264 * probably first extent we're gonna free will be last in block
4266 err = ext4_writepage_trans_blocks(inode);
4267 handle = ext4_journal_start(inode, err);
4271 if (inode->i_size % PAGE_CACHE_SIZE != 0) {
4272 page_len = PAGE_CACHE_SIZE -
4273 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4275 err = ext4_discard_partial_page_buffers(handle,
4276 mapping, inode->i_size, page_len, 0);
4282 if (ext4_orphan_add(handle, inode))
4285 down_write(&EXT4_I(inode)->i_data_sem);
4286 ext4_ext_invalidate_cache(inode);
4288 ext4_discard_preallocations(inode);
4291 * TODO: optimization is possible here.
4292 * Probably we need not scan at all,
4293 * because page truncation is enough.
4296 /* we have to know where to truncate from in crash case */
4297 EXT4_I(inode)->i_disksize = inode->i_size;
4298 ext4_mark_inode_dirty(handle, inode);
4300 last_block = (inode->i_size + sb->s_blocksize - 1)
4301 >> EXT4_BLOCK_SIZE_BITS(sb);
4302 err = ext4_es_remove_extent(inode, last_block,
4303 EXT_MAX_BLOCKS - last_block);
4304 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4306 /* In a multi-transaction truncate, we only make the final
4307 * transaction synchronous.
4310 ext4_handle_sync(handle);
4312 up_write(&EXT4_I(inode)->i_data_sem);
4316 * If this was a simple ftruncate() and the file will remain alive,
4317 * then we need to clear up the orphan record which we created above.
4318 * However, if this was a real unlink then we were called by
4319 * ext4_delete_inode(), and we allow that function to clean up the
4320 * orphan info for us.
4323 ext4_orphan_del(handle, inode);
4325 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4326 ext4_mark_inode_dirty(handle, inode);
4327 ext4_journal_stop(handle);
4330 static void ext4_falloc_update_inode(struct inode *inode,
4331 int mode, loff_t new_size, int update_ctime)
4333 struct timespec now;
4336 now = current_fs_time(inode->i_sb);
4337 if (!timespec_equal(&inode->i_ctime, &now))
4338 inode->i_ctime = now;
4341 * Update only when preallocation was requested beyond
4344 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
4345 if (new_size > i_size_read(inode))
4346 i_size_write(inode, new_size);
4347 if (new_size > EXT4_I(inode)->i_disksize)
4348 ext4_update_i_disksize(inode, new_size);
4351 * Mark that we allocate beyond EOF so the subsequent truncate
4352 * can proceed even if the new size is the same as i_size.
4354 if (new_size > i_size_read(inode))
4355 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4361 * preallocate space for a file. This implements ext4's fallocate file
4362 * operation, which gets called from sys_fallocate system call.
4363 * For block-mapped files, posix_fallocate should fall back to the method
4364 * of writing zeroes to the required new blocks (the same behavior which is
4365 * expected for file systems which do not support fallocate() system call).
4367 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4369 struct inode *inode = file->f_path.dentry->d_inode;
4372 unsigned int max_blocks;
4377 struct ext4_map_blocks map;
4378 unsigned int credits, blkbits = inode->i_blkbits;
4381 * currently supporting (pre)allocate mode for extent-based
4384 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4387 /* Return error if mode is not supported */
4388 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
4391 if (mode & FALLOC_FL_PUNCH_HOLE)
4392 return ext4_punch_hole(file, offset, len);
4394 trace_ext4_fallocate_enter(inode, offset, len, mode);
4395 map.m_lblk = offset >> blkbits;
4397 * We can't just convert len to max_blocks because
4398 * If blocksize = 4096 offset = 3072 and len = 2048
4400 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4403 * credits to insert 1 extent into extent tree
4405 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4406 mutex_lock(&inode->i_mutex);
4407 ret = inode_newsize_ok(inode, (len + offset));
4409 mutex_unlock(&inode->i_mutex);
4410 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4413 flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
4414 if (mode & FALLOC_FL_KEEP_SIZE)
4415 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4417 * Don't normalize the request if it can fit in one extent so
4418 * that it doesn't get unnecessarily split into multiple
4421 if (len <= EXT_UNINIT_MAX_LEN << blkbits)
4422 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4424 /* Prevent race condition between unwritten */
4425 ext4_flush_unwritten_io(inode);
4427 while (ret >= 0 && ret < max_blocks) {
4428 map.m_lblk = map.m_lblk + ret;
4429 map.m_len = max_blocks = max_blocks - ret;
4430 handle = ext4_journal_start(inode, credits);
4431 if (IS_ERR(handle)) {
4432 ret = PTR_ERR(handle);
4435 ret = ext4_map_blocks(handle, inode, &map, flags);
4439 printk(KERN_ERR "%s: ext4_ext_map_blocks "
4440 "returned error inode#%lu, block=%u, "
4441 "max_blocks=%u", __func__,
4442 inode->i_ino, map.m_lblk, max_blocks);
4444 ext4_mark_inode_dirty(handle, inode);
4445 ret2 = ext4_journal_stop(handle);
4448 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
4449 blkbits) >> blkbits))
4450 new_size = offset + len;
4452 new_size = ((loff_t) map.m_lblk + ret) << blkbits;
4454 ext4_falloc_update_inode(inode, mode, new_size,
4455 (map.m_flags & EXT4_MAP_NEW));
4456 ext4_mark_inode_dirty(handle, inode);
4457 if ((file->f_flags & O_SYNC) && ret >= max_blocks)
4458 ext4_handle_sync(handle);
4459 ret2 = ext4_journal_stop(handle);
4463 if (ret == -ENOSPC &&
4464 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4468 mutex_unlock(&inode->i_mutex);
4469 trace_ext4_fallocate_exit(inode, offset, max_blocks,
4470 ret > 0 ? ret2 : ret);
4471 return ret > 0 ? ret2 : ret;
4475 * This function convert a range of blocks to written extents
4476 * The caller of this function will pass the start offset and the size.
4477 * all unwritten extents within this range will be converted to
4480 * This function is called from the direct IO end io call back
4481 * function, to convert the fallocated extents after IO is completed.
4482 * Returns 0 on success.
4484 int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
4488 unsigned int max_blocks;
4491 struct ext4_map_blocks map;
4492 unsigned int credits, blkbits = inode->i_blkbits;
4494 map.m_lblk = offset >> blkbits;
4496 * We can't just convert len to max_blocks because
4497 * If blocksize = 4096 offset = 3072 and len = 2048
4499 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
4502 * credits to insert 1 extent into extent tree
4504 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4505 while (ret >= 0 && ret < max_blocks) {
4507 map.m_len = (max_blocks -= ret);
4508 handle = ext4_journal_start(inode, credits);
4509 if (IS_ERR(handle)) {
4510 ret = PTR_ERR(handle);
4513 ret = ext4_map_blocks(handle, inode, &map,
4514 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4517 ext4_msg(inode->i_sb, KERN_ERR,
4518 "%s:%d: inode #%lu: block %u: len %u: "
4519 "ext4_ext_map_blocks returned %d",
4520 __func__, __LINE__, inode->i_ino, map.m_lblk,
4523 ext4_mark_inode_dirty(handle, inode);
4524 ret2 = ext4_journal_stop(handle);
4525 if (ret <= 0 || ret2 )
4528 return ret > 0 ? ret2 : ret;
4532 * If newex is not existing extent (newex->ec_start equals zero) find
4533 * delayed extent at start of newex and update newex accordingly and
4534 * return start of the next delayed extent.
4536 * If newex is existing extent (newex->ec_start is not equal zero)
4537 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
4538 * extent found. Leave newex unmodified.
4540 static int ext4_find_delayed_extent(struct inode *inode,
4541 struct ext4_ext_cache *newex)
4543 struct extent_status es;
4544 ext4_lblk_t next_del;
4546 es.start = newex->ec_block;
4547 next_del = ext4_es_find_extent(inode, &es);
4549 if (newex->ec_start == 0) {
4551 * No extent in extent-tree contains block @newex->ec_start,
4552 * then the block may stay in 1)a hole or 2)delayed-extent.
4558 if (es.start > newex->ec_block) {
4560 newex->ec_len = min(es.start - newex->ec_block,
4565 newex->ec_len = es.start + es.len - newex->ec_block;
4570 /* fiemap flags we can handle specified here */
4571 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4573 static int ext4_xattr_fiemap(struct inode *inode,
4574 struct fiemap_extent_info *fieinfo)
4578 __u32 flags = FIEMAP_EXTENT_LAST;
4579 int blockbits = inode->i_sb->s_blocksize_bits;
4583 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4584 struct ext4_iloc iloc;
4585 int offset; /* offset of xattr in inode */
4587 error = ext4_get_inode_loc(inode, &iloc);
4590 physical = iloc.bh->b_blocknr << blockbits;
4591 offset = EXT4_GOOD_OLD_INODE_SIZE +
4592 EXT4_I(inode)->i_extra_isize;
4594 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4595 flags |= FIEMAP_EXTENT_DATA_INLINE;
4597 } else { /* external block */
4598 physical = EXT4_I(inode)->i_file_acl << blockbits;
4599 length = inode->i_sb->s_blocksize;
4603 error = fiemap_fill_next_extent(fieinfo, 0, physical,
4605 return (error < 0 ? error : 0);
4609 * ext4_ext_punch_hole
4611 * Punches a hole of "length" bytes in a file starting
4614 * @inode: The inode of the file to punch a hole in
4615 * @offset: The starting byte offset of the hole
4616 * @length: The length of the hole
4618 * Returns the number of blocks removed or negative on err
4620 int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
4622 struct inode *inode = file->f_path.dentry->d_inode;
4623 struct super_block *sb = inode->i_sb;
4624 ext4_lblk_t first_block, stop_block;
4625 struct address_space *mapping = inode->i_mapping;
4627 loff_t first_page, last_page, page_len;
4628 loff_t first_page_offset, last_page_offset;
4629 int credits, err = 0;
4632 * Write out all dirty pages to avoid race conditions
4633 * Then release them.
4635 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
4636 err = filemap_write_and_wait_range(mapping,
4637 offset, offset + length - 1);
4643 mutex_lock(&inode->i_mutex);
4644 /* It's not possible punch hole on append only file */
4645 if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {
4649 if (IS_SWAPFILE(inode)) {
4654 /* No need to punch hole beyond i_size */
4655 if (offset >= inode->i_size)
4659 * If the hole extends beyond i_size, set the hole
4660 * to end after the page that contains i_size
4662 if (offset + length > inode->i_size) {
4663 length = inode->i_size +
4664 PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) -
4668 first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
4669 last_page = (offset + length) >> PAGE_CACHE_SHIFT;
4671 first_page_offset = first_page << PAGE_CACHE_SHIFT;
4672 last_page_offset = last_page << PAGE_CACHE_SHIFT;
4674 /* Now release the pages */
4675 if (last_page_offset > first_page_offset) {
4676 truncate_pagecache_range(inode, first_page_offset,
4677 last_page_offset - 1);
4680 /* Wait all existing dio workers, newcomers will block on i_mutex */
4681 ext4_inode_block_unlocked_dio(inode);
4682 err = ext4_flush_unwritten_io(inode);
4685 inode_dio_wait(inode);
4687 credits = ext4_writepage_trans_blocks(inode);
4688 handle = ext4_journal_start(inode, credits);
4689 if (IS_ERR(handle)) {
4690 err = PTR_ERR(handle);
4696 * Now we need to zero out the non-page-aligned data in the
4697 * pages at the start and tail of the hole, and unmap the buffer
4698 * heads for the block aligned regions of the page that were
4699 * completely zeroed.
4701 if (first_page > last_page) {
4703 * If the file space being truncated is contained within a page
4704 * just zero out and unmap the middle of that page
4706 err = ext4_discard_partial_page_buffers(handle,
4707 mapping, offset, length, 0);
4713 * zero out and unmap the partial page that contains
4714 * the start of the hole
4716 page_len = first_page_offset - offset;
4718 err = ext4_discard_partial_page_buffers(handle, mapping,
4719 offset, page_len, 0);
4725 * zero out and unmap the partial page that contains
4726 * the end of the hole
4728 page_len = offset + length - last_page_offset;
4730 err = ext4_discard_partial_page_buffers(handle, mapping,
4731 last_page_offset, page_len, 0);
4738 * If i_size is contained in the last page, we need to
4739 * unmap and zero the partial page after i_size
4741 if (inode->i_size >> PAGE_CACHE_SHIFT == last_page &&
4742 inode->i_size % PAGE_CACHE_SIZE != 0) {
4744 page_len = PAGE_CACHE_SIZE -
4745 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4748 err = ext4_discard_partial_page_buffers(handle,
4749 mapping, inode->i_size, page_len, 0);
4756 first_block = (offset + sb->s_blocksize - 1) >>
4757 EXT4_BLOCK_SIZE_BITS(sb);
4758 stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
4760 /* If there are no blocks to remove, return now */
4761 if (first_block >= stop_block)
4764 down_write(&EXT4_I(inode)->i_data_sem);
4765 ext4_ext_invalidate_cache(inode);
4766 ext4_discard_preallocations(inode);
4768 err = ext4_es_remove_extent(inode, first_block,
4769 stop_block - first_block);
4770 err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
4772 ext4_ext_invalidate_cache(inode);
4773 ext4_discard_preallocations(inode);
4776 ext4_handle_sync(handle);
4778 up_write(&EXT4_I(inode)->i_data_sem);
4781 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4782 ext4_mark_inode_dirty(handle, inode);
4783 ext4_journal_stop(handle);
4785 ext4_inode_resume_unlocked_dio(inode);
4787 mutex_unlock(&inode->i_mutex);
4791 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4792 __u64 start, __u64 len)
4794 ext4_lblk_t start_blk;
4797 /* fallback to generic here if not in extents fmt */
4798 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4799 return generic_block_fiemap(inode, fieinfo, start, len,
4802 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
4805 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4806 error = ext4_xattr_fiemap(inode, fieinfo);
4808 ext4_lblk_t len_blks;
4811 start_blk = start >> inode->i_sb->s_blocksize_bits;
4812 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
4813 if (last_blk >= EXT_MAX_BLOCKS)
4814 last_blk = EXT_MAX_BLOCKS-1;
4815 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
4818 * Walk the extent tree gathering extent information
4819 * and pushing extents back to the user.
4821 error = ext4_fill_fiemap_extents(inode, start_blk,