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
32 #include <linux/module.h>
34 #include <linux/time.h>
35 #include <linux/jbd2.h>
36 #include <linux/highuid.h>
37 #include <linux/pagemap.h>
38 #include <linux/quotaops.h>
39 #include <linux/string.h>
40 #include <linux/slab.h>
41 #include <linux/falloc.h>
42 #include <asm/uaccess.h>
43 #include <linux/fiemap.h>
44 #include "ext4_jbd2.h"
45 #include "ext4_extents.h"
50 * combine low and high parts of physical block number into ext4_fsblk_t
52 ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
56 block = le32_to_cpu(ex->ee_start_lo);
57 block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
63 * combine low and high parts of a leaf physical block number into ext4_fsblk_t
65 ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
69 block = le32_to_cpu(ix->ei_leaf_lo);
70 block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
75 * ext4_ext_store_pblock:
76 * stores a large physical block number into an extent struct,
77 * breaking it into parts
79 void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
81 ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
82 ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
86 * ext4_idx_store_pblock:
87 * stores a large physical block number into an index struct,
88 * breaking it into parts
90 static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
92 ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
93 ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
96 static int ext4_ext_truncate_extend_restart(handle_t *handle,
102 if (!ext4_handle_valid(handle))
104 if (handle->h_buffer_credits > needed)
106 err = ext4_journal_extend(handle, needed);
109 err = ext4_truncate_restart_trans(handle, inode, needed);
111 * We have dropped i_data_sem so someone might have cached again
112 * an extent we are going to truncate.
114 ext4_ext_invalidate_cache(inode);
124 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
125 struct ext4_ext_path *path)
128 /* path points to block */
129 return ext4_journal_get_write_access(handle, path->p_bh);
131 /* path points to leaf/index in inode body */
132 /* we use in-core data, no need to protect them */
142 static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
143 struct ext4_ext_path *path)
147 /* path points to block */
148 err = ext4_handle_dirty_metadata(handle, inode, path->p_bh);
150 /* path points to leaf/index in inode body */
151 err = ext4_mark_inode_dirty(handle, inode);
156 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
157 struct ext4_ext_path *path,
160 struct ext4_inode_info *ei = EXT4_I(inode);
161 ext4_fsblk_t bg_start;
162 ext4_fsblk_t last_block;
163 ext4_grpblk_t colour;
164 ext4_group_t block_group;
165 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
169 struct ext4_extent *ex;
170 depth = path->p_depth;
172 /* try to predict block placement */
173 ex = path[depth].p_ext;
175 return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block));
177 /* it looks like index is empty;
178 * try to find starting block from index itself */
179 if (path[depth].p_bh)
180 return path[depth].p_bh->b_blocknr;
183 /* OK. use inode's group */
184 block_group = ei->i_block_group;
185 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
187 * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
188 * block groups per flexgroup, reserve the first block
189 * group for directories and special files. Regular
190 * files will start at the second block group. This
191 * tends to speed up directory access and improves
194 block_group &= ~(flex_size-1);
195 if (S_ISREG(inode->i_mode))
198 bg_start = (block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) +
199 le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block);
200 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
203 * If we are doing delayed allocation, we don't need take
204 * colour into account.
206 if (test_opt(inode->i_sb, DELALLOC))
209 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
210 colour = (current->pid % 16) *
211 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
213 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
214 return bg_start + colour + block;
218 * Allocation for a meta data block
221 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
222 struct ext4_ext_path *path,
223 struct ext4_extent *ex, int *err)
225 ext4_fsblk_t goal, newblock;
227 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
228 newblock = ext4_new_meta_blocks(handle, inode, goal, NULL, err);
232 static int ext4_ext_space_block(struct inode *inode)
236 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
237 / sizeof(struct ext4_extent);
238 #ifdef AGGRESSIVE_TEST
245 static int ext4_ext_space_block_idx(struct inode *inode)
249 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
250 / sizeof(struct ext4_extent_idx);
251 #ifdef AGGRESSIVE_TEST
258 static int ext4_ext_space_root(struct inode *inode)
262 size = sizeof(EXT4_I(inode)->i_data);
263 size -= sizeof(struct ext4_extent_header);
264 size /= sizeof(struct ext4_extent);
265 #ifdef AGGRESSIVE_TEST
272 static int ext4_ext_space_root_idx(struct inode *inode)
276 size = sizeof(EXT4_I(inode)->i_data);
277 size -= sizeof(struct ext4_extent_header);
278 size /= sizeof(struct ext4_extent_idx);
279 #ifdef AGGRESSIVE_TEST
287 * Calculate the number of metadata blocks needed
288 * to allocate @blocks
289 * Worse case is one block per extent
291 int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
293 int lcap, icap, rcap, leafs, idxs, num;
294 int newextents = blocks;
296 rcap = ext4_ext_space_root_idx(inode);
297 lcap = ext4_ext_space_block(inode);
298 icap = ext4_ext_space_block_idx(inode);
300 /* number of new leaf blocks needed */
301 num = leafs = (newextents + lcap - 1) / lcap;
304 * Worse case, we need separate index block(s)
305 * to link all new leaf blocks
307 idxs = (leafs + icap - 1) / icap;
310 idxs = (idxs + icap - 1) / icap;
311 } while (idxs > rcap);
317 ext4_ext_max_entries(struct inode *inode, int depth)
321 if (depth == ext_depth(inode)) {
323 max = ext4_ext_space_root(inode);
325 max = ext4_ext_space_root_idx(inode);
328 max = ext4_ext_space_block(inode);
330 max = ext4_ext_space_block_idx(inode);
336 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
338 ext4_fsblk_t block = ext_pblock(ext);
339 int len = ext4_ext_get_actual_len(ext);
341 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
344 static int ext4_valid_extent_idx(struct inode *inode,
345 struct ext4_extent_idx *ext_idx)
347 ext4_fsblk_t block = idx_pblock(ext_idx);
349 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
352 static int ext4_valid_extent_entries(struct inode *inode,
353 struct ext4_extent_header *eh,
356 struct ext4_extent *ext;
357 struct ext4_extent_idx *ext_idx;
358 unsigned short entries;
359 if (eh->eh_entries == 0)
362 entries = le16_to_cpu(eh->eh_entries);
366 ext = EXT_FIRST_EXTENT(eh);
368 if (!ext4_valid_extent(inode, ext))
374 ext_idx = EXT_FIRST_INDEX(eh);
376 if (!ext4_valid_extent_idx(inode, ext_idx))
385 static int __ext4_ext_check(const char *function, struct inode *inode,
386 struct ext4_extent_header *eh,
389 const char *error_msg;
392 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
393 error_msg = "invalid magic";
396 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
397 error_msg = "unexpected eh_depth";
400 if (unlikely(eh->eh_max == 0)) {
401 error_msg = "invalid eh_max";
404 max = ext4_ext_max_entries(inode, depth);
405 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
406 error_msg = "too large eh_max";
409 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
410 error_msg = "invalid eh_entries";
413 if (!ext4_valid_extent_entries(inode, eh, depth)) {
414 error_msg = "invalid extent entries";
420 ext4_error(inode->i_sb, function,
421 "bad header/extent in inode #%lu: %s - magic %x, "
422 "entries %u, max %u(%u), depth %u(%u)",
423 inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
424 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
425 max, le16_to_cpu(eh->eh_depth), depth);
430 #define ext4_ext_check(inode, eh, depth) \
431 __ext4_ext_check(__func__, inode, eh, depth)
433 int ext4_ext_check_inode(struct inode *inode)
435 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
439 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
441 int k, l = path->p_depth;
444 for (k = 0; k <= l; k++, path++) {
446 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
447 idx_pblock(path->p_idx));
448 } else if (path->p_ext) {
449 ext_debug(" %d:[%d]%d:%llu ",
450 le32_to_cpu(path->p_ext->ee_block),
451 ext4_ext_is_uninitialized(path->p_ext),
452 ext4_ext_get_actual_len(path->p_ext),
453 ext_pblock(path->p_ext));
460 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
462 int depth = ext_depth(inode);
463 struct ext4_extent_header *eh;
464 struct ext4_extent *ex;
470 eh = path[depth].p_hdr;
471 ex = EXT_FIRST_EXTENT(eh);
473 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
475 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
476 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
477 ext4_ext_is_uninitialized(ex),
478 ext4_ext_get_actual_len(ex), ext_pblock(ex));
483 #define ext4_ext_show_path(inode, path)
484 #define ext4_ext_show_leaf(inode, path)
487 void ext4_ext_drop_refs(struct ext4_ext_path *path)
489 int depth = path->p_depth;
492 for (i = 0; i <= depth; i++, path++)
500 * ext4_ext_binsearch_idx:
501 * binary search for the closest index of the given block
502 * the header must be checked before calling this
505 ext4_ext_binsearch_idx(struct inode *inode,
506 struct ext4_ext_path *path, ext4_lblk_t block)
508 struct ext4_extent_header *eh = path->p_hdr;
509 struct ext4_extent_idx *r, *l, *m;
512 ext_debug("binsearch for %u(idx): ", block);
514 l = EXT_FIRST_INDEX(eh) + 1;
515 r = EXT_LAST_INDEX(eh);
518 if (block < le32_to_cpu(m->ei_block))
522 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
523 m, le32_to_cpu(m->ei_block),
524 r, le32_to_cpu(r->ei_block));
528 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
529 idx_pblock(path->p_idx));
531 #ifdef CHECK_BINSEARCH
533 struct ext4_extent_idx *chix, *ix;
536 chix = ix = EXT_FIRST_INDEX(eh);
537 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
539 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
540 printk(KERN_DEBUG "k=%d, ix=0x%p, "
542 ix, EXT_FIRST_INDEX(eh));
543 printk(KERN_DEBUG "%u <= %u\n",
544 le32_to_cpu(ix->ei_block),
545 le32_to_cpu(ix[-1].ei_block));
547 BUG_ON(k && le32_to_cpu(ix->ei_block)
548 <= le32_to_cpu(ix[-1].ei_block));
549 if (block < le32_to_cpu(ix->ei_block))
553 BUG_ON(chix != path->p_idx);
560 * ext4_ext_binsearch:
561 * binary search for closest extent of the given block
562 * the header must be checked before calling this
565 ext4_ext_binsearch(struct inode *inode,
566 struct ext4_ext_path *path, ext4_lblk_t block)
568 struct ext4_extent_header *eh = path->p_hdr;
569 struct ext4_extent *r, *l, *m;
571 if (eh->eh_entries == 0) {
573 * this leaf is empty:
574 * we get such a leaf in split/add case
579 ext_debug("binsearch for %u: ", block);
581 l = EXT_FIRST_EXTENT(eh) + 1;
582 r = EXT_LAST_EXTENT(eh);
586 if (block < le32_to_cpu(m->ee_block))
590 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
591 m, le32_to_cpu(m->ee_block),
592 r, le32_to_cpu(r->ee_block));
596 ext_debug(" -> %d:%llu:[%d]%d ",
597 le32_to_cpu(path->p_ext->ee_block),
598 ext_pblock(path->p_ext),
599 ext4_ext_is_uninitialized(path->p_ext),
600 ext4_ext_get_actual_len(path->p_ext));
602 #ifdef CHECK_BINSEARCH
604 struct ext4_extent *chex, *ex;
607 chex = ex = EXT_FIRST_EXTENT(eh);
608 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
609 BUG_ON(k && le32_to_cpu(ex->ee_block)
610 <= le32_to_cpu(ex[-1].ee_block));
611 if (block < le32_to_cpu(ex->ee_block))
615 BUG_ON(chex != path->p_ext);
621 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
623 struct ext4_extent_header *eh;
625 eh = ext_inode_hdr(inode);
628 eh->eh_magic = EXT4_EXT_MAGIC;
629 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode));
630 ext4_mark_inode_dirty(handle, inode);
631 ext4_ext_invalidate_cache(inode);
635 struct ext4_ext_path *
636 ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
637 struct ext4_ext_path *path)
639 struct ext4_extent_header *eh;
640 struct buffer_head *bh;
641 short int depth, i, ppos = 0, alloc = 0;
643 eh = ext_inode_hdr(inode);
644 depth = ext_depth(inode);
646 /* account possible depth increase */
648 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
651 return ERR_PTR(-ENOMEM);
658 /* walk through the tree */
660 int need_to_validate = 0;
662 ext_debug("depth %d: num %d, max %d\n",
663 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
665 ext4_ext_binsearch_idx(inode, path + ppos, block);
666 path[ppos].p_block = idx_pblock(path[ppos].p_idx);
667 path[ppos].p_depth = i;
668 path[ppos].p_ext = NULL;
670 bh = sb_getblk(inode->i_sb, path[ppos].p_block);
673 if (!bh_uptodate_or_lock(bh)) {
674 if (bh_submit_read(bh) < 0) {
678 /* validate the extent entries */
679 need_to_validate = 1;
681 eh = ext_block_hdr(bh);
683 BUG_ON(ppos > depth);
684 path[ppos].p_bh = bh;
685 path[ppos].p_hdr = eh;
688 if (need_to_validate && ext4_ext_check(inode, eh, i))
692 path[ppos].p_depth = i;
693 path[ppos].p_ext = NULL;
694 path[ppos].p_idx = NULL;
697 ext4_ext_binsearch(inode, path + ppos, block);
698 /* if not an empty leaf */
699 if (path[ppos].p_ext)
700 path[ppos].p_block = ext_pblock(path[ppos].p_ext);
702 ext4_ext_show_path(inode, path);
707 ext4_ext_drop_refs(path);
710 return ERR_PTR(-EIO);
714 * ext4_ext_insert_index:
715 * insert new index [@logical;@ptr] into the block at @curp;
716 * check where to insert: before @curp or after @curp
718 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
719 struct ext4_ext_path *curp,
720 int logical, ext4_fsblk_t ptr)
722 struct ext4_extent_idx *ix;
725 err = ext4_ext_get_access(handle, inode, curp);
729 BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block));
730 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
731 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
733 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
734 len = (len - 1) * sizeof(struct ext4_extent_idx);
735 len = len < 0 ? 0 : len;
736 ext_debug("insert new index %d after: %llu. "
737 "move %d from 0x%p to 0x%p\n",
739 (curp->p_idx + 1), (curp->p_idx + 2));
740 memmove(curp->p_idx + 2, curp->p_idx + 1, len);
742 ix = curp->p_idx + 1;
745 len = len * sizeof(struct ext4_extent_idx);
746 len = len < 0 ? 0 : len;
747 ext_debug("insert new index %d before: %llu. "
748 "move %d from 0x%p to 0x%p\n",
750 curp->p_idx, (curp->p_idx + 1));
751 memmove(curp->p_idx + 1, curp->p_idx, len);
755 ix->ei_block = cpu_to_le32(logical);
756 ext4_idx_store_pblock(ix, ptr);
757 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
759 BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries)
760 > le16_to_cpu(curp->p_hdr->eh_max));
761 BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr));
763 err = ext4_ext_dirty(handle, inode, curp);
764 ext4_std_error(inode->i_sb, err);
771 * inserts new subtree into the path, using free index entry
773 * - allocates all needed blocks (new leaf and all intermediate index blocks)
774 * - makes decision where to split
775 * - moves remaining extents and index entries (right to the split point)
776 * into the newly allocated blocks
777 * - initializes subtree
779 static int ext4_ext_split(handle_t *handle, struct inode *inode,
780 struct ext4_ext_path *path,
781 struct ext4_extent *newext, int at)
783 struct buffer_head *bh = NULL;
784 int depth = ext_depth(inode);
785 struct ext4_extent_header *neh;
786 struct ext4_extent_idx *fidx;
787 struct ext4_extent *ex;
789 ext4_fsblk_t newblock, oldblock;
791 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
794 /* make decision: where to split? */
795 /* FIXME: now decision is simplest: at current extent */
797 /* if current leaf will be split, then we should use
798 * border from split point */
799 BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr));
800 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
801 border = path[depth].p_ext[1].ee_block;
802 ext_debug("leaf will be split."
803 " next leaf starts at %d\n",
804 le32_to_cpu(border));
806 border = newext->ee_block;
807 ext_debug("leaf will be added."
808 " next leaf starts at %d\n",
809 le32_to_cpu(border));
813 * If error occurs, then we break processing
814 * and mark filesystem read-only. index won't
815 * be inserted and tree will be in consistent
816 * state. Next mount will repair buffers too.
820 * Get array to track all allocated blocks.
821 * We need this to handle errors and free blocks
824 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
828 /* allocate all needed blocks */
829 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
830 for (a = 0; a < depth - at; a++) {
831 newblock = ext4_ext_new_meta_block(handle, inode, path,
835 ablocks[a] = newblock;
838 /* initialize new leaf */
839 newblock = ablocks[--a];
840 BUG_ON(newblock == 0);
841 bh = sb_getblk(inode->i_sb, newblock);
848 err = ext4_journal_get_create_access(handle, bh);
852 neh = ext_block_hdr(bh);
854 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
855 neh->eh_magic = EXT4_EXT_MAGIC;
857 ex = EXT_FIRST_EXTENT(neh);
859 /* move remainder of path[depth] to the new leaf */
860 BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max);
861 /* start copy from next extent */
862 /* TODO: we could do it by single memmove */
865 while (path[depth].p_ext <=
866 EXT_MAX_EXTENT(path[depth].p_hdr)) {
867 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
868 le32_to_cpu(path[depth].p_ext->ee_block),
869 ext_pblock(path[depth].p_ext),
870 ext4_ext_is_uninitialized(path[depth].p_ext),
871 ext4_ext_get_actual_len(path[depth].p_ext),
873 /*memmove(ex++, path[depth].p_ext++,
874 sizeof(struct ext4_extent));
880 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m);
881 le16_add_cpu(&neh->eh_entries, m);
884 set_buffer_uptodate(bh);
887 err = ext4_handle_dirty_metadata(handle, inode, bh);
893 /* correct old leaf */
895 err = ext4_ext_get_access(handle, inode, path + depth);
898 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
899 err = ext4_ext_dirty(handle, inode, path + depth);
905 /* create intermediate indexes */
909 ext_debug("create %d intermediate indices\n", k);
910 /* insert new index into current index block */
911 /* current depth stored in i var */
915 newblock = ablocks[--a];
916 bh = sb_getblk(inode->i_sb, newblock);
923 err = ext4_journal_get_create_access(handle, bh);
927 neh = ext_block_hdr(bh);
928 neh->eh_entries = cpu_to_le16(1);
929 neh->eh_magic = EXT4_EXT_MAGIC;
930 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
931 neh->eh_depth = cpu_to_le16(depth - i);
932 fidx = EXT_FIRST_INDEX(neh);
933 fidx->ei_block = border;
934 ext4_idx_store_pblock(fidx, oldblock);
936 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
937 i, newblock, le32_to_cpu(border), oldblock);
942 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
943 EXT_MAX_INDEX(path[i].p_hdr));
944 BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) !=
945 EXT_LAST_INDEX(path[i].p_hdr));
946 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
947 ext_debug("%d: move %d:%llu in new index %llu\n", i,
948 le32_to_cpu(path[i].p_idx->ei_block),
949 idx_pblock(path[i].p_idx),
951 /*memmove(++fidx, path[i].p_idx++,
952 sizeof(struct ext4_extent_idx));
954 BUG_ON(neh->eh_entries > neh->eh_max);*/
959 memmove(++fidx, path[i].p_idx - m,
960 sizeof(struct ext4_extent_idx) * m);
961 le16_add_cpu(&neh->eh_entries, m);
963 set_buffer_uptodate(bh);
966 err = ext4_handle_dirty_metadata(handle, inode, bh);
972 /* correct old index */
974 err = ext4_ext_get_access(handle, inode, path + i);
977 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
978 err = ext4_ext_dirty(handle, inode, path + i);
986 /* insert new index */
987 err = ext4_ext_insert_index(handle, inode, path + at,
988 le32_to_cpu(border), newblock);
992 if (buffer_locked(bh))
998 /* free all allocated blocks in error case */
999 for (i = 0; i < depth; i++) {
1002 ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
1011 * ext4_ext_grow_indepth:
1012 * implements tree growing procedure:
1013 * - allocates new block
1014 * - moves top-level data (index block or leaf) into the new block
1015 * - initializes new top-level, creating index that points to the
1016 * just created block
1018 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1019 struct ext4_ext_path *path,
1020 struct ext4_extent *newext)
1022 struct ext4_ext_path *curp = path;
1023 struct ext4_extent_header *neh;
1024 struct ext4_extent_idx *fidx;
1025 struct buffer_head *bh;
1026 ext4_fsblk_t newblock;
1029 newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err);
1033 bh = sb_getblk(inode->i_sb, newblock);
1036 ext4_std_error(inode->i_sb, err);
1041 err = ext4_journal_get_create_access(handle, bh);
1047 /* move top-level index/leaf into new block */
1048 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
1050 /* set size of new block */
1051 neh = ext_block_hdr(bh);
1052 /* old root could have indexes or leaves
1053 * so calculate e_max right way */
1054 if (ext_depth(inode))
1055 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
1057 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
1058 neh->eh_magic = EXT4_EXT_MAGIC;
1059 set_buffer_uptodate(bh);
1062 err = ext4_handle_dirty_metadata(handle, inode, bh);
1066 /* create index in new top-level index: num,max,pointer */
1067 err = ext4_ext_get_access(handle, inode, curp);
1071 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
1072 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
1073 curp->p_hdr->eh_entries = cpu_to_le16(1);
1074 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
1076 if (path[0].p_hdr->eh_depth)
1077 curp->p_idx->ei_block =
1078 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
1080 curp->p_idx->ei_block =
1081 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
1082 ext4_idx_store_pblock(curp->p_idx, newblock);
1084 neh = ext_inode_hdr(inode);
1085 fidx = EXT_FIRST_INDEX(neh);
1086 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1087 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1088 le32_to_cpu(fidx->ei_block), idx_pblock(fidx));
1090 neh->eh_depth = cpu_to_le16(path->p_depth + 1);
1091 err = ext4_ext_dirty(handle, inode, curp);
1099 * ext4_ext_create_new_leaf:
1100 * finds empty index and adds new leaf.
1101 * if no free index is found, then it requests in-depth growing.
1103 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1104 struct ext4_ext_path *path,
1105 struct ext4_extent *newext)
1107 struct ext4_ext_path *curp;
1108 int depth, i, err = 0;
1111 i = depth = ext_depth(inode);
1113 /* walk up to the tree and look for free index entry */
1114 curp = path + depth;
1115 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1120 /* we use already allocated block for index block,
1121 * so subsequent data blocks should be contiguous */
1122 if (EXT_HAS_FREE_INDEX(curp)) {
1123 /* if we found index with free entry, then use that
1124 * entry: create all needed subtree and add new leaf */
1125 err = ext4_ext_split(handle, inode, path, newext, i);
1130 ext4_ext_drop_refs(path);
1131 path = ext4_ext_find_extent(inode,
1132 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1135 err = PTR_ERR(path);
1137 /* tree is full, time to grow in depth */
1138 err = ext4_ext_grow_indepth(handle, inode, path, newext);
1143 ext4_ext_drop_refs(path);
1144 path = ext4_ext_find_extent(inode,
1145 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1148 err = PTR_ERR(path);
1153 * only first (depth 0 -> 1) produces free space;
1154 * in all other cases we have to split the grown tree
1156 depth = ext_depth(inode);
1157 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1158 /* now we need to split */
1168 * search the closest allocated block to the left for *logical
1169 * and returns it at @logical + it's physical address at @phys
1170 * if *logical is the smallest allocated block, the function
1171 * returns 0 at @phys
1172 * return value contains 0 (success) or error code
1175 ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path,
1176 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1178 struct ext4_extent_idx *ix;
1179 struct ext4_extent *ex;
1182 BUG_ON(path == NULL);
1183 depth = path->p_depth;
1186 if (depth == 0 && path->p_ext == NULL)
1189 /* usually extent in the path covers blocks smaller
1190 * then *logical, but it can be that extent is the
1191 * first one in the file */
1193 ex = path[depth].p_ext;
1194 ee_len = ext4_ext_get_actual_len(ex);
1195 if (*logical < le32_to_cpu(ex->ee_block)) {
1196 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1197 while (--depth >= 0) {
1198 ix = path[depth].p_idx;
1199 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1204 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
1206 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1207 *phys = ext_pblock(ex) + ee_len - 1;
1212 * search the closest allocated block to the right for *logical
1213 * and returns it at @logical + it's physical address at @phys
1214 * if *logical is the smallest allocated block, the function
1215 * returns 0 at @phys
1216 * return value contains 0 (success) or error code
1219 ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path,
1220 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1222 struct buffer_head *bh = NULL;
1223 struct ext4_extent_header *eh;
1224 struct ext4_extent_idx *ix;
1225 struct ext4_extent *ex;
1227 int depth; /* Note, NOT eh_depth; depth from top of tree */
1230 BUG_ON(path == NULL);
1231 depth = path->p_depth;
1234 if (depth == 0 && path->p_ext == NULL)
1237 /* usually extent in the path covers blocks smaller
1238 * then *logical, but it can be that extent is the
1239 * first one in the file */
1241 ex = path[depth].p_ext;
1242 ee_len = ext4_ext_get_actual_len(ex);
1243 if (*logical < le32_to_cpu(ex->ee_block)) {
1244 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1245 while (--depth >= 0) {
1246 ix = path[depth].p_idx;
1247 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1249 *logical = le32_to_cpu(ex->ee_block);
1250 *phys = ext_pblock(ex);
1254 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
1256 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1257 /* next allocated block in this leaf */
1259 *logical = le32_to_cpu(ex->ee_block);
1260 *phys = ext_pblock(ex);
1264 /* go up and search for index to the right */
1265 while (--depth >= 0) {
1266 ix = path[depth].p_idx;
1267 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1271 /* we've gone up to the root and found no index to the right */
1275 /* we've found index to the right, let's
1276 * follow it and find the closest allocated
1277 * block to the right */
1279 block = idx_pblock(ix);
1280 while (++depth < path->p_depth) {
1281 bh = sb_bread(inode->i_sb, block);
1284 eh = ext_block_hdr(bh);
1285 /* subtract from p_depth to get proper eh_depth */
1286 if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
1290 ix = EXT_FIRST_INDEX(eh);
1291 block = idx_pblock(ix);
1295 bh = sb_bread(inode->i_sb, block);
1298 eh = ext_block_hdr(bh);
1299 if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
1303 ex = EXT_FIRST_EXTENT(eh);
1304 *logical = le32_to_cpu(ex->ee_block);
1305 *phys = ext_pblock(ex);
1311 * ext4_ext_next_allocated_block:
1312 * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
1313 * NOTE: it considers block number from index entry as
1314 * allocated block. Thus, index entries have to be consistent
1318 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1322 BUG_ON(path == NULL);
1323 depth = path->p_depth;
1325 if (depth == 0 && path->p_ext == NULL)
1326 return EXT_MAX_BLOCK;
1328 while (depth >= 0) {
1329 if (depth == path->p_depth) {
1331 if (path[depth].p_ext !=
1332 EXT_LAST_EXTENT(path[depth].p_hdr))
1333 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1336 if (path[depth].p_idx !=
1337 EXT_LAST_INDEX(path[depth].p_hdr))
1338 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1343 return EXT_MAX_BLOCK;
1347 * ext4_ext_next_leaf_block:
1348 * returns first allocated block from next leaf or EXT_MAX_BLOCK
1350 static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
1351 struct ext4_ext_path *path)
1355 BUG_ON(path == NULL);
1356 depth = path->p_depth;
1358 /* zero-tree has no leaf blocks at all */
1360 return EXT_MAX_BLOCK;
1362 /* go to index block */
1365 while (depth >= 0) {
1366 if (path[depth].p_idx !=
1367 EXT_LAST_INDEX(path[depth].p_hdr))
1368 return (ext4_lblk_t)
1369 le32_to_cpu(path[depth].p_idx[1].ei_block);
1373 return EXT_MAX_BLOCK;
1377 * ext4_ext_correct_indexes:
1378 * if leaf gets modified and modified extent is first in the leaf,
1379 * then we have to correct all indexes above.
1380 * TODO: do we need to correct tree in all cases?
1382 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1383 struct ext4_ext_path *path)
1385 struct ext4_extent_header *eh;
1386 int depth = ext_depth(inode);
1387 struct ext4_extent *ex;
1391 eh = path[depth].p_hdr;
1392 ex = path[depth].p_ext;
1397 /* there is no tree at all */
1401 if (ex != EXT_FIRST_EXTENT(eh)) {
1402 /* we correct tree if first leaf got modified only */
1407 * TODO: we need correction if border is smaller than current one
1410 border = path[depth].p_ext->ee_block;
1411 err = ext4_ext_get_access(handle, inode, path + k);
1414 path[k].p_idx->ei_block = border;
1415 err = ext4_ext_dirty(handle, inode, path + k);
1420 /* change all left-side indexes */
1421 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1423 err = ext4_ext_get_access(handle, inode, path + k);
1426 path[k].p_idx->ei_block = border;
1427 err = ext4_ext_dirty(handle, inode, path + k);
1436 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1437 struct ext4_extent *ex2)
1439 unsigned short ext1_ee_len, ext2_ee_len, max_len;
1442 * Make sure that either both extents are uninitialized, or
1445 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1448 if (ext4_ext_is_uninitialized(ex1))
1449 max_len = EXT_UNINIT_MAX_LEN;
1451 max_len = EXT_INIT_MAX_LEN;
1453 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1454 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1456 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1457 le32_to_cpu(ex2->ee_block))
1461 * To allow future support for preallocated extents to be added
1462 * as an RO_COMPAT feature, refuse to merge to extents if
1463 * this can result in the top bit of ee_len being set.
1465 if (ext1_ee_len + ext2_ee_len > max_len)
1467 #ifdef AGGRESSIVE_TEST
1468 if (ext1_ee_len >= 4)
1472 if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2))
1478 * This function tries to merge the "ex" extent to the next extent in the tree.
1479 * It always tries to merge towards right. If you want to merge towards
1480 * left, pass "ex - 1" as argument instead of "ex".
1481 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1482 * 1 if they got merged.
1484 int ext4_ext_try_to_merge(struct inode *inode,
1485 struct ext4_ext_path *path,
1486 struct ext4_extent *ex)
1488 struct ext4_extent_header *eh;
1489 unsigned int depth, len;
1491 int uninitialized = 0;
1493 depth = ext_depth(inode);
1494 BUG_ON(path[depth].p_hdr == NULL);
1495 eh = path[depth].p_hdr;
1497 while (ex < EXT_LAST_EXTENT(eh)) {
1498 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1500 /* merge with next extent! */
1501 if (ext4_ext_is_uninitialized(ex))
1503 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1504 + ext4_ext_get_actual_len(ex + 1));
1506 ext4_ext_mark_uninitialized(ex);
1508 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1509 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1510 * sizeof(struct ext4_extent);
1511 memmove(ex + 1, ex + 2, len);
1513 le16_add_cpu(&eh->eh_entries, -1);
1515 WARN_ON(eh->eh_entries == 0);
1516 if (!eh->eh_entries)
1517 ext4_error(inode->i_sb, "ext4_ext_try_to_merge",
1518 "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
1525 * check if a portion of the "newext" extent overlaps with an
1528 * If there is an overlap discovered, it updates the length of the newext
1529 * such that there will be no overlap, and then returns 1.
1530 * If there is no overlap found, it returns 0.
1532 unsigned int ext4_ext_check_overlap(struct inode *inode,
1533 struct ext4_extent *newext,
1534 struct ext4_ext_path *path)
1537 unsigned int depth, len1;
1538 unsigned int ret = 0;
1540 b1 = le32_to_cpu(newext->ee_block);
1541 len1 = ext4_ext_get_actual_len(newext);
1542 depth = ext_depth(inode);
1543 if (!path[depth].p_ext)
1545 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1548 * get the next allocated block if the extent in the path
1549 * is before the requested block(s)
1552 b2 = ext4_ext_next_allocated_block(path);
1553 if (b2 == EXT_MAX_BLOCK)
1557 /* check for wrap through zero on extent logical start block*/
1558 if (b1 + len1 < b1) {
1559 len1 = EXT_MAX_BLOCK - b1;
1560 newext->ee_len = cpu_to_le16(len1);
1564 /* check for overlap */
1565 if (b1 + len1 > b2) {
1566 newext->ee_len = cpu_to_le16(b2 - b1);
1574 * ext4_ext_insert_extent:
1575 * tries to merge requsted extent into the existing extent or
1576 * inserts requested extent as new one into the tree,
1577 * creating new leaf in the no-space case.
1579 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1580 struct ext4_ext_path *path,
1581 struct ext4_extent *newext)
1583 struct ext4_extent_header *eh;
1584 struct ext4_extent *ex, *fex;
1585 struct ext4_extent *nearex; /* nearest extent */
1586 struct ext4_ext_path *npath = NULL;
1587 int depth, len, err;
1589 unsigned uninitialized = 0;
1591 BUG_ON(ext4_ext_get_actual_len(newext) == 0);
1592 depth = ext_depth(inode);
1593 ex = path[depth].p_ext;
1594 BUG_ON(path[depth].p_hdr == NULL);
1596 /* try to insert block into found extent and return */
1597 if (ex && ext4_can_extents_be_merged(inode, ex, newext)) {
1598 ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n",
1599 ext4_ext_is_uninitialized(newext),
1600 ext4_ext_get_actual_len(newext),
1601 le32_to_cpu(ex->ee_block),
1602 ext4_ext_is_uninitialized(ex),
1603 ext4_ext_get_actual_len(ex), ext_pblock(ex));
1604 err = ext4_ext_get_access(handle, inode, path + depth);
1609 * ext4_can_extents_be_merged should have checked that either
1610 * both extents are uninitialized, or both aren't. Thus we
1611 * need to check only one of them here.
1613 if (ext4_ext_is_uninitialized(ex))
1615 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1616 + ext4_ext_get_actual_len(newext));
1618 ext4_ext_mark_uninitialized(ex);
1619 eh = path[depth].p_hdr;
1625 depth = ext_depth(inode);
1626 eh = path[depth].p_hdr;
1627 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1630 /* probably next leaf has space for us? */
1631 fex = EXT_LAST_EXTENT(eh);
1632 next = ext4_ext_next_leaf_block(inode, path);
1633 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
1634 && next != EXT_MAX_BLOCK) {
1635 ext_debug("next leaf block - %d\n", next);
1636 BUG_ON(npath != NULL);
1637 npath = ext4_ext_find_extent(inode, next, NULL);
1639 return PTR_ERR(npath);
1640 BUG_ON(npath->p_depth != path->p_depth);
1641 eh = npath[depth].p_hdr;
1642 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1643 ext_debug("next leaf isnt full(%d)\n",
1644 le16_to_cpu(eh->eh_entries));
1648 ext_debug("next leaf has no free space(%d,%d)\n",
1649 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1653 * There is no free space in the found leaf.
1654 * We're gonna add a new leaf in the tree.
1656 err = ext4_ext_create_new_leaf(handle, inode, path, newext);
1659 depth = ext_depth(inode);
1660 eh = path[depth].p_hdr;
1663 nearex = path[depth].p_ext;
1665 err = ext4_ext_get_access(handle, inode, path + depth);
1670 /* there is no extent in this leaf, create first one */
1671 ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n",
1672 le32_to_cpu(newext->ee_block),
1674 ext4_ext_is_uninitialized(newext),
1675 ext4_ext_get_actual_len(newext));
1676 path[depth].p_ext = EXT_FIRST_EXTENT(eh);
1677 } else if (le32_to_cpu(newext->ee_block)
1678 > le32_to_cpu(nearex->ee_block)) {
1679 /* BUG_ON(newext->ee_block == nearex->ee_block); */
1680 if (nearex != EXT_LAST_EXTENT(eh)) {
1681 len = EXT_MAX_EXTENT(eh) - nearex;
1682 len = (len - 1) * sizeof(struct ext4_extent);
1683 len = len < 0 ? 0 : len;
1684 ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, "
1685 "move %d from 0x%p to 0x%p\n",
1686 le32_to_cpu(newext->ee_block),
1688 ext4_ext_is_uninitialized(newext),
1689 ext4_ext_get_actual_len(newext),
1690 nearex, len, nearex + 1, nearex + 2);
1691 memmove(nearex + 2, nearex + 1, len);
1693 path[depth].p_ext = nearex + 1;
1695 BUG_ON(newext->ee_block == nearex->ee_block);
1696 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
1697 len = len < 0 ? 0 : len;
1698 ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, "
1699 "move %d from 0x%p to 0x%p\n",
1700 le32_to_cpu(newext->ee_block),
1702 ext4_ext_is_uninitialized(newext),
1703 ext4_ext_get_actual_len(newext),
1704 nearex, len, nearex + 1, nearex + 2);
1705 memmove(nearex + 1, nearex, len);
1706 path[depth].p_ext = nearex;
1709 le16_add_cpu(&eh->eh_entries, 1);
1710 nearex = path[depth].p_ext;
1711 nearex->ee_block = newext->ee_block;
1712 ext4_ext_store_pblock(nearex, ext_pblock(newext));
1713 nearex->ee_len = newext->ee_len;
1716 /* try to merge extents to the right */
1717 ext4_ext_try_to_merge(inode, path, nearex);
1719 /* try to merge extents to the left */
1721 /* time to correct all indexes above */
1722 err = ext4_ext_correct_indexes(handle, inode, path);
1726 err = ext4_ext_dirty(handle, inode, path + depth);
1730 ext4_ext_drop_refs(npath);
1733 ext4_ext_invalidate_cache(inode);
1737 int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
1738 ext4_lblk_t num, ext_prepare_callback func,
1741 struct ext4_ext_path *path = NULL;
1742 struct ext4_ext_cache cbex;
1743 struct ext4_extent *ex;
1744 ext4_lblk_t next, start = 0, end = 0;
1745 ext4_lblk_t last = block + num;
1746 int depth, exists, err = 0;
1748 BUG_ON(func == NULL);
1749 BUG_ON(inode == NULL);
1751 while (block < last && block != EXT_MAX_BLOCK) {
1753 /* find extent for this block */
1754 path = ext4_ext_find_extent(inode, block, path);
1756 err = PTR_ERR(path);
1761 depth = ext_depth(inode);
1762 BUG_ON(path[depth].p_hdr == NULL);
1763 ex = path[depth].p_ext;
1764 next = ext4_ext_next_allocated_block(path);
1768 /* there is no extent yet, so try to allocate
1769 * all requested space */
1772 } else if (le32_to_cpu(ex->ee_block) > block) {
1773 /* need to allocate space before found extent */
1775 end = le32_to_cpu(ex->ee_block);
1776 if (block + num < end)
1778 } else if (block >= le32_to_cpu(ex->ee_block)
1779 + ext4_ext_get_actual_len(ex)) {
1780 /* need to allocate space after found extent */
1785 } else if (block >= le32_to_cpu(ex->ee_block)) {
1787 * some part of requested space is covered
1791 end = le32_to_cpu(ex->ee_block)
1792 + ext4_ext_get_actual_len(ex);
1793 if (block + num < end)
1799 BUG_ON(end <= start);
1802 cbex.ec_block = start;
1803 cbex.ec_len = end - start;
1805 cbex.ec_type = EXT4_EXT_CACHE_GAP;
1807 cbex.ec_block = le32_to_cpu(ex->ee_block);
1808 cbex.ec_len = ext4_ext_get_actual_len(ex);
1809 cbex.ec_start = ext_pblock(ex);
1810 cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
1813 BUG_ON(cbex.ec_len == 0);
1814 err = func(inode, path, &cbex, ex, cbdata);
1815 ext4_ext_drop_refs(path);
1820 if (err == EXT_REPEAT)
1822 else if (err == EXT_BREAK) {
1827 if (ext_depth(inode) != depth) {
1828 /* depth was changed. we have to realloc path */
1833 block = cbex.ec_block + cbex.ec_len;
1837 ext4_ext_drop_refs(path);
1845 ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
1846 __u32 len, ext4_fsblk_t start, int type)
1848 struct ext4_ext_cache *cex;
1850 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1851 cex = &EXT4_I(inode)->i_cached_extent;
1852 cex->ec_type = type;
1853 cex->ec_block = block;
1855 cex->ec_start = start;
1856 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1860 * ext4_ext_put_gap_in_cache:
1861 * calculate boundaries of the gap that the requested block fits into
1862 * and cache this gap
1865 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
1868 int depth = ext_depth(inode);
1871 struct ext4_extent *ex;
1873 ex = path[depth].p_ext;
1875 /* there is no extent yet, so gap is [0;-] */
1877 len = EXT_MAX_BLOCK;
1878 ext_debug("cache gap(whole file):");
1879 } else if (block < le32_to_cpu(ex->ee_block)) {
1881 len = le32_to_cpu(ex->ee_block) - block;
1882 ext_debug("cache gap(before): %u [%u:%u]",
1884 le32_to_cpu(ex->ee_block),
1885 ext4_ext_get_actual_len(ex));
1886 } else if (block >= le32_to_cpu(ex->ee_block)
1887 + ext4_ext_get_actual_len(ex)) {
1889 lblock = le32_to_cpu(ex->ee_block)
1890 + ext4_ext_get_actual_len(ex);
1892 next = ext4_ext_next_allocated_block(path);
1893 ext_debug("cache gap(after): [%u:%u] %u",
1894 le32_to_cpu(ex->ee_block),
1895 ext4_ext_get_actual_len(ex),
1897 BUG_ON(next == lblock);
1898 len = next - lblock;
1904 ext_debug(" -> %u:%lu\n", lblock, len);
1905 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP);
1909 ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
1910 struct ext4_extent *ex)
1912 struct ext4_ext_cache *cex;
1913 int ret = EXT4_EXT_CACHE_NO;
1916 * We borrow i_block_reservation_lock to protect i_cached_extent
1918 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1919 cex = &EXT4_I(inode)->i_cached_extent;
1921 /* has cache valid data? */
1922 if (cex->ec_type == EXT4_EXT_CACHE_NO)
1925 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP &&
1926 cex->ec_type != EXT4_EXT_CACHE_EXTENT);
1927 if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
1928 ex->ee_block = cpu_to_le32(cex->ec_block);
1929 ext4_ext_store_pblock(ex, cex->ec_start);
1930 ex->ee_len = cpu_to_le16(cex->ec_len);
1931 ext_debug("%u cached by %u:%u:%llu\n",
1933 cex->ec_block, cex->ec_len, cex->ec_start);
1937 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1943 * removes index from the index block.
1944 * It's used in truncate case only, thus all requests are for
1945 * last index in the block only.
1947 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
1948 struct ext4_ext_path *path)
1950 struct buffer_head *bh;
1954 /* free index block */
1956 leaf = idx_pblock(path->p_idx);
1957 BUG_ON(path->p_hdr->eh_entries == 0);
1958 err = ext4_ext_get_access(handle, inode, path);
1961 le16_add_cpu(&path->p_hdr->eh_entries, -1);
1962 err = ext4_ext_dirty(handle, inode, path);
1965 ext_debug("index is empty, remove it, free block %llu\n", leaf);
1966 bh = sb_find_get_block(inode->i_sb, leaf);
1967 ext4_forget(handle, 1, inode, bh, leaf);
1968 ext4_free_blocks(handle, inode, leaf, 1, 1);
1973 * ext4_ext_calc_credits_for_single_extent:
1974 * This routine returns max. credits that needed to insert an extent
1975 * to the extent tree.
1976 * When pass the actual path, the caller should calculate credits
1979 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
1980 struct ext4_ext_path *path)
1983 int depth = ext_depth(inode);
1986 /* probably there is space in leaf? */
1987 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
1988 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
1991 * There are some space in the leaf tree, no
1992 * need to account for leaf block credit
1994 * bitmaps and block group descriptor blocks
1995 * and other metadat blocks still need to be
1998 /* 1 bitmap, 1 block group descriptor */
1999 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2004 return ext4_chunk_trans_blocks(inode, nrblocks);
2008 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2010 * if nrblocks are fit in a single extent (chunk flag is 1), then
2011 * in the worse case, each tree level index/leaf need to be changed
2012 * if the tree split due to insert a new extent, then the old tree
2013 * index/leaf need to be updated too
2015 * If the nrblocks are discontiguous, they could cause
2016 * the whole tree split more than once, but this is really rare.
2018 int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
2021 int depth = ext_depth(inode);
2031 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2032 struct ext4_extent *ex,
2033 ext4_lblk_t from, ext4_lblk_t to)
2035 struct buffer_head *bh;
2036 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2037 int i, metadata = 0;
2039 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2041 #ifdef EXTENTS_STATS
2043 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2044 spin_lock(&sbi->s_ext_stats_lock);
2045 sbi->s_ext_blocks += ee_len;
2046 sbi->s_ext_extents++;
2047 if (ee_len < sbi->s_ext_min)
2048 sbi->s_ext_min = ee_len;
2049 if (ee_len > sbi->s_ext_max)
2050 sbi->s_ext_max = ee_len;
2051 if (ext_depth(inode) > sbi->s_depth_max)
2052 sbi->s_depth_max = ext_depth(inode);
2053 spin_unlock(&sbi->s_ext_stats_lock);
2056 if (from >= le32_to_cpu(ex->ee_block)
2057 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2062 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2063 start = ext_pblock(ex) + ee_len - num;
2064 ext_debug("free last %u blocks starting %llu\n", num, start);
2065 for (i = 0; i < num; i++) {
2066 bh = sb_find_get_block(inode->i_sb, start + i);
2067 ext4_forget(handle, 0, inode, bh, start + i);
2069 ext4_free_blocks(handle, inode, start, num, metadata);
2070 } else if (from == le32_to_cpu(ex->ee_block)
2071 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
2072 printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
2073 from, to, le32_to_cpu(ex->ee_block), ee_len);
2075 printk(KERN_INFO "strange request: removal(2) "
2076 "%u-%u from %u:%u\n",
2077 from, to, le32_to_cpu(ex->ee_block), ee_len);
2083 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2084 struct ext4_ext_path *path, ext4_lblk_t start)
2086 int err = 0, correct_index = 0;
2087 int depth = ext_depth(inode), credits;
2088 struct ext4_extent_header *eh;
2089 ext4_lblk_t a, b, block;
2091 ext4_lblk_t ex_ee_block;
2092 unsigned short ex_ee_len;
2093 unsigned uninitialized = 0;
2094 struct ext4_extent *ex;
2096 /* the header must be checked already in ext4_ext_remove_space() */
2097 ext_debug("truncate since %u in leaf\n", start);
2098 if (!path[depth].p_hdr)
2099 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2100 eh = path[depth].p_hdr;
2103 /* find where to start removing */
2104 ex = EXT_LAST_EXTENT(eh);
2106 ex_ee_block = le32_to_cpu(ex->ee_block);
2107 ex_ee_len = ext4_ext_get_actual_len(ex);
2109 while (ex >= EXT_FIRST_EXTENT(eh) &&
2110 ex_ee_block + ex_ee_len > start) {
2112 if (ext4_ext_is_uninitialized(ex))
2117 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2118 uninitialized, ex_ee_len);
2119 path[depth].p_ext = ex;
2121 a = ex_ee_block > start ? ex_ee_block : start;
2122 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ?
2123 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK;
2125 ext_debug(" border %u:%u\n", a, b);
2127 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) {
2131 } else if (a != ex_ee_block) {
2132 /* remove tail of the extent */
2133 block = ex_ee_block;
2135 } else if (b != ex_ee_block + ex_ee_len - 1) {
2136 /* remove head of the extent */
2139 /* there is no "make a hole" API yet */
2142 /* remove whole extent: excellent! */
2143 block = ex_ee_block;
2145 BUG_ON(a != ex_ee_block);
2146 BUG_ON(b != ex_ee_block + ex_ee_len - 1);
2150 * 3 for leaf, sb, and inode plus 2 (bmap and group
2151 * descriptor) for each block group; assume two block
2152 * groups plus ex_ee_len/blocks_per_block_group for
2155 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2156 if (ex == EXT_FIRST_EXTENT(eh)) {
2158 credits += (ext_depth(inode)) + 1;
2160 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
2162 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2166 err = ext4_ext_get_access(handle, inode, path + depth);
2170 err = ext4_remove_blocks(handle, inode, ex, a, b);
2175 /* this extent is removed; mark slot entirely unused */
2176 ext4_ext_store_pblock(ex, 0);
2177 le16_add_cpu(&eh->eh_entries, -1);
2180 ex->ee_block = cpu_to_le32(block);
2181 ex->ee_len = cpu_to_le16(num);
2183 * Do not mark uninitialized if all the blocks in the
2184 * extent have been removed.
2186 if (uninitialized && num)
2187 ext4_ext_mark_uninitialized(ex);
2189 err = ext4_ext_dirty(handle, inode, path + depth);
2193 ext_debug("new extent: %u:%u:%llu\n", block, num,
2196 ex_ee_block = le32_to_cpu(ex->ee_block);
2197 ex_ee_len = ext4_ext_get_actual_len(ex);
2200 if (correct_index && eh->eh_entries)
2201 err = ext4_ext_correct_indexes(handle, inode, path);
2203 /* if this leaf is free, then we should
2204 * remove it from index block above */
2205 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2206 err = ext4_ext_rm_idx(handle, inode, path + depth);
2213 * ext4_ext_more_to_rm:
2214 * returns 1 if current index has to be freed (even partial)
2217 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2219 BUG_ON(path->p_idx == NULL);
2221 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2225 * if truncate on deeper level happened, it wasn't partial,
2226 * so we have to consider current index for truncation
2228 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2233 static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
2235 struct super_block *sb = inode->i_sb;
2236 int depth = ext_depth(inode);
2237 struct ext4_ext_path *path;
2241 ext_debug("truncate since %u\n", start);
2243 /* probably first extent we're gonna free will be last in block */
2244 handle = ext4_journal_start(inode, depth + 1);
2246 return PTR_ERR(handle);
2248 ext4_ext_invalidate_cache(inode);
2251 * We start scanning from right side, freeing all the blocks
2252 * after i_size and walking into the tree depth-wise.
2254 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS);
2256 ext4_journal_stop(handle);
2259 path[0].p_hdr = ext_inode_hdr(inode);
2260 if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
2264 path[0].p_depth = depth;
2266 while (i >= 0 && err == 0) {
2268 /* this is leaf block */
2269 err = ext4_ext_rm_leaf(handle, inode, path, start);
2270 /* root level has p_bh == NULL, brelse() eats this */
2271 brelse(path[i].p_bh);
2272 path[i].p_bh = NULL;
2277 /* this is index block */
2278 if (!path[i].p_hdr) {
2279 ext_debug("initialize header\n");
2280 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2283 if (!path[i].p_idx) {
2284 /* this level hasn't been touched yet */
2285 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2286 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2287 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2289 le16_to_cpu(path[i].p_hdr->eh_entries));
2291 /* we were already here, see at next index */
2295 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2296 i, EXT_FIRST_INDEX(path[i].p_hdr),
2298 if (ext4_ext_more_to_rm(path + i)) {
2299 struct buffer_head *bh;
2300 /* go to the next level */
2301 ext_debug("move to level %d (block %llu)\n",
2302 i + 1, idx_pblock(path[i].p_idx));
2303 memset(path + i + 1, 0, sizeof(*path));
2304 bh = sb_bread(sb, idx_pblock(path[i].p_idx));
2306 /* should we reset i_size? */
2310 if (WARN_ON(i + 1 > depth)) {
2314 if (ext4_ext_check(inode, ext_block_hdr(bh),
2319 path[i + 1].p_bh = bh;
2321 /* save actual number of indexes since this
2322 * number is changed at the next iteration */
2323 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2326 /* we finished processing this index, go up */
2327 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2328 /* index is empty, remove it;
2329 * handle must be already prepared by the
2330 * truncatei_leaf() */
2331 err = ext4_ext_rm_idx(handle, inode, path + i);
2333 /* root level has p_bh == NULL, brelse() eats this */
2334 brelse(path[i].p_bh);
2335 path[i].p_bh = NULL;
2337 ext_debug("return to level %d\n", i);
2341 /* TODO: flexible tree reduction should be here */
2342 if (path->p_hdr->eh_entries == 0) {
2344 * truncate to zero freed all the tree,
2345 * so we need to correct eh_depth
2347 err = ext4_ext_get_access(handle, inode, path);
2349 ext_inode_hdr(inode)->eh_depth = 0;
2350 ext_inode_hdr(inode)->eh_max =
2351 cpu_to_le16(ext4_ext_space_root(inode));
2352 err = ext4_ext_dirty(handle, inode, path);
2356 ext4_ext_drop_refs(path);
2358 ext4_journal_stop(handle);
2364 * called at mount time
2366 void ext4_ext_init(struct super_block *sb)
2369 * possible initialization would be here
2372 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2373 printk(KERN_INFO "EXT4-fs: file extents enabled");
2374 #ifdef AGGRESSIVE_TEST
2375 printk(", aggressive tests");
2377 #ifdef CHECK_BINSEARCH
2378 printk(", check binsearch");
2380 #ifdef EXTENTS_STATS
2384 #ifdef EXTENTS_STATS
2385 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2386 EXT4_SB(sb)->s_ext_min = 1 << 30;
2387 EXT4_SB(sb)->s_ext_max = 0;
2393 * called at umount time
2395 void ext4_ext_release(struct super_block *sb)
2397 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
2400 #ifdef EXTENTS_STATS
2401 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2402 struct ext4_sb_info *sbi = EXT4_SB(sb);
2403 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2404 sbi->s_ext_blocks, sbi->s_ext_extents,
2405 sbi->s_ext_blocks / sbi->s_ext_extents);
2406 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2407 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2412 static void bi_complete(struct bio *bio, int error)
2414 complete((struct completion *)bio->bi_private);
2417 /* FIXME!! we need to try to merge to left or right after zero-out */
2418 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2422 int blkbits, blocksize;
2424 struct completion event;
2425 unsigned int ee_len, len, done, offset;
2428 blkbits = inode->i_blkbits;
2429 blocksize = inode->i_sb->s_blocksize;
2430 ee_len = ext4_ext_get_actual_len(ex);
2431 ee_pblock = ext_pblock(ex);
2433 /* convert ee_pblock to 512 byte sectors */
2434 ee_pblock = ee_pblock << (blkbits - 9);
2436 while (ee_len > 0) {
2438 if (ee_len > BIO_MAX_PAGES)
2439 len = BIO_MAX_PAGES;
2443 bio = bio_alloc(GFP_NOIO, len);
2444 bio->bi_sector = ee_pblock;
2445 bio->bi_bdev = inode->i_sb->s_bdev;
2449 while (done < len) {
2450 ret = bio_add_page(bio, ZERO_PAGE(0),
2452 if (ret != blocksize) {
2454 * We can't add any more pages because of
2455 * hardware limitations. Start a new bio.
2460 offset += blocksize;
2461 if (offset >= PAGE_CACHE_SIZE)
2465 init_completion(&event);
2466 bio->bi_private = &event;
2467 bio->bi_end_io = bi_complete;
2468 submit_bio(WRITE, bio);
2469 wait_for_completion(&event);
2471 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
2479 ee_pblock += done << (blkbits - 9);
2484 #define EXT4_EXT_ZERO_LEN 7
2487 * This function is called by ext4_ext_get_blocks() if someone tries to write
2488 * to an uninitialized extent. It may result in splitting the uninitialized
2489 * extent into multiple extents (upto three - one initialized and two
2491 * There are three possibilities:
2492 * a> There is no split required: Entire extent should be initialized
2493 * b> Splits in two extents: Write is happening at either end of the extent
2494 * c> Splits in three extents: Somone is writing in middle of the extent
2496 static int ext4_ext_convert_to_initialized(handle_t *handle,
2497 struct inode *inode,
2498 struct ext4_ext_path *path,
2500 unsigned int max_blocks)
2502 struct ext4_extent *ex, newex, orig_ex;
2503 struct ext4_extent *ex1 = NULL;
2504 struct ext4_extent *ex2 = NULL;
2505 struct ext4_extent *ex3 = NULL;
2506 struct ext4_extent_header *eh;
2507 ext4_lblk_t ee_block;
2508 unsigned int allocated, ee_len, depth;
2509 ext4_fsblk_t newblock;
2513 depth = ext_depth(inode);
2514 eh = path[depth].p_hdr;
2515 ex = path[depth].p_ext;
2516 ee_block = le32_to_cpu(ex->ee_block);
2517 ee_len = ext4_ext_get_actual_len(ex);
2518 allocated = ee_len - (iblock - ee_block);
2519 newblock = iblock - ee_block + ext_pblock(ex);
2521 orig_ex.ee_block = ex->ee_block;
2522 orig_ex.ee_len = cpu_to_le16(ee_len);
2523 ext4_ext_store_pblock(&orig_ex, ext_pblock(ex));
2525 err = ext4_ext_get_access(handle, inode, path + depth);
2528 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
2529 if (ee_len <= 2*EXT4_EXT_ZERO_LEN) {
2530 err = ext4_ext_zeroout(inode, &orig_ex);
2532 goto fix_extent_len;
2533 /* update the extent length and mark as initialized */
2534 ex->ee_block = orig_ex.ee_block;
2535 ex->ee_len = orig_ex.ee_len;
2536 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2537 ext4_ext_dirty(handle, inode, path + depth);
2538 /* zeroed the full extent */
2542 /* ex1: ee_block to iblock - 1 : uninitialized */
2543 if (iblock > ee_block) {
2545 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2546 ext4_ext_mark_uninitialized(ex1);
2550 * for sanity, update the length of the ex2 extent before
2551 * we insert ex3, if ex1 is NULL. This is to avoid temporary
2552 * overlap of blocks.
2554 if (!ex1 && allocated > max_blocks)
2555 ex2->ee_len = cpu_to_le16(max_blocks);
2556 /* ex3: to ee_block + ee_len : uninitialised */
2557 if (allocated > max_blocks) {
2558 unsigned int newdepth;
2559 /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
2560 if (allocated <= EXT4_EXT_ZERO_LEN) {
2562 * iblock == ee_block is handled by the zerouout
2564 * Mark first half uninitialized.
2565 * Mark second half initialized and zero out the
2566 * initialized extent
2568 ex->ee_block = orig_ex.ee_block;
2569 ex->ee_len = cpu_to_le16(ee_len - allocated);
2570 ext4_ext_mark_uninitialized(ex);
2571 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2572 ext4_ext_dirty(handle, inode, path + depth);
2575 ex3->ee_block = cpu_to_le32(iblock);
2576 ext4_ext_store_pblock(ex3, newblock);
2577 ex3->ee_len = cpu_to_le16(allocated);
2578 err = ext4_ext_insert_extent(handle, inode, path, ex3);
2579 if (err == -ENOSPC) {
2580 err = ext4_ext_zeroout(inode, &orig_ex);
2582 goto fix_extent_len;
2583 ex->ee_block = orig_ex.ee_block;
2584 ex->ee_len = orig_ex.ee_len;
2585 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2586 ext4_ext_dirty(handle, inode, path + depth);
2587 /* blocks available from iblock */
2591 goto fix_extent_len;
2594 * We need to zero out the second half because
2595 * an fallocate request can update file size and
2596 * converting the second half to initialized extent
2597 * implies that we can leak some junk data to user
2600 err = ext4_ext_zeroout(inode, ex3);
2603 * We should actually mark the
2604 * second half as uninit and return error
2605 * Insert would have changed the extent
2607 depth = ext_depth(inode);
2608 ext4_ext_drop_refs(path);
2609 path = ext4_ext_find_extent(inode,
2612 err = PTR_ERR(path);
2615 /* get the second half extent details */
2616 ex = path[depth].p_ext;
2617 err = ext4_ext_get_access(handle, inode,
2621 ext4_ext_mark_uninitialized(ex);
2622 ext4_ext_dirty(handle, inode, path + depth);
2626 /* zeroed the second half */
2630 ex3->ee_block = cpu_to_le32(iblock + max_blocks);
2631 ext4_ext_store_pblock(ex3, newblock + max_blocks);
2632 ex3->ee_len = cpu_to_le16(allocated - max_blocks);
2633 ext4_ext_mark_uninitialized(ex3);
2634 err = ext4_ext_insert_extent(handle, inode, path, ex3);
2635 if (err == -ENOSPC) {
2636 err = ext4_ext_zeroout(inode, &orig_ex);
2638 goto fix_extent_len;
2639 /* update the extent length and mark as initialized */
2640 ex->ee_block = orig_ex.ee_block;
2641 ex->ee_len = orig_ex.ee_len;
2642 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2643 ext4_ext_dirty(handle, inode, path + depth);
2644 /* zeroed the full extent */
2645 /* blocks available from iblock */
2649 goto fix_extent_len;
2651 * The depth, and hence eh & ex might change
2652 * as part of the insert above.
2654 newdepth = ext_depth(inode);
2656 * update the extent length after successful insert of the
2659 orig_ex.ee_len = cpu_to_le16(ee_len -
2660 ext4_ext_get_actual_len(ex3));
2662 ext4_ext_drop_refs(path);
2663 path = ext4_ext_find_extent(inode, iblock, path);
2665 err = PTR_ERR(path);
2668 eh = path[depth].p_hdr;
2669 ex = path[depth].p_ext;
2673 err = ext4_ext_get_access(handle, inode, path + depth);
2677 allocated = max_blocks;
2679 /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
2680 * to insert a extent in the middle zerout directly
2681 * otherwise give the extent a chance to merge to left
2683 if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
2684 iblock != ee_block) {
2685 err = ext4_ext_zeroout(inode, &orig_ex);
2687 goto fix_extent_len;
2688 /* update the extent length and mark as initialized */
2689 ex->ee_block = orig_ex.ee_block;
2690 ex->ee_len = orig_ex.ee_len;
2691 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2692 ext4_ext_dirty(handle, inode, path + depth);
2693 /* zero out the first half */
2694 /* blocks available from iblock */
2699 * If there was a change of depth as part of the
2700 * insertion of ex3 above, we need to update the length
2701 * of the ex1 extent again here
2703 if (ex1 && ex1 != ex) {
2705 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2706 ext4_ext_mark_uninitialized(ex1);
2709 /* ex2: iblock to iblock + maxblocks-1 : initialised */
2710 ex2->ee_block = cpu_to_le32(iblock);
2711 ext4_ext_store_pblock(ex2, newblock);
2712 ex2->ee_len = cpu_to_le16(allocated);
2716 * New (initialized) extent starts from the first block
2717 * in the current extent. i.e., ex2 == ex
2718 * We have to see if it can be merged with the extent
2721 if (ex2 > EXT_FIRST_EXTENT(eh)) {
2723 * To merge left, pass "ex2 - 1" to try_to_merge(),
2724 * since it merges towards right _only_.
2726 ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
2728 err = ext4_ext_correct_indexes(handle, inode, path);
2731 depth = ext_depth(inode);
2736 * Try to Merge towards right. This might be required
2737 * only when the whole extent is being written to.
2738 * i.e. ex2 == ex and ex3 == NULL.
2741 ret = ext4_ext_try_to_merge(inode, path, ex2);
2743 err = ext4_ext_correct_indexes(handle, inode, path);
2748 /* Mark modified extent as dirty */
2749 err = ext4_ext_dirty(handle, inode, path + depth);
2752 err = ext4_ext_insert_extent(handle, inode, path, &newex);
2753 if (err == -ENOSPC) {
2754 err = ext4_ext_zeroout(inode, &orig_ex);
2756 goto fix_extent_len;
2757 /* update the extent length and mark as initialized */
2758 ex->ee_block = orig_ex.ee_block;
2759 ex->ee_len = orig_ex.ee_len;
2760 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2761 ext4_ext_dirty(handle, inode, path + depth);
2762 /* zero out the first half */
2765 goto fix_extent_len;
2767 ext4_ext_show_leaf(inode, path);
2768 return err ? err : allocated;
2771 ex->ee_block = orig_ex.ee_block;
2772 ex->ee_len = orig_ex.ee_len;
2773 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2774 ext4_ext_mark_uninitialized(ex);
2775 ext4_ext_dirty(handle, inode, path + depth);
2780 * Block allocation/map/preallocation routine for extents based files
2783 * Need to be called with
2784 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
2785 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
2787 * return > 0, number of of blocks already mapped/allocated
2788 * if create == 0 and these are pre-allocated blocks
2789 * buffer head is unmapped
2790 * otherwise blocks are mapped
2792 * return = 0, if plain look up failed (blocks have not been allocated)
2793 * buffer head is unmapped
2795 * return < 0, error case.
2797 int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
2799 unsigned int max_blocks, struct buffer_head *bh_result,
2802 struct ext4_ext_path *path = NULL;
2803 struct ext4_extent_header *eh;
2804 struct ext4_extent newex, *ex;
2805 ext4_fsblk_t newblock;
2806 int err = 0, depth, ret, cache_type;
2807 unsigned int allocated = 0;
2808 struct ext4_allocation_request ar;
2810 __clear_bit(BH_New, &bh_result->b_state);
2811 ext_debug("blocks %u/%u requested for inode %lu\n",
2812 iblock, max_blocks, inode->i_ino);
2814 /* check in cache */
2815 cache_type = ext4_ext_in_cache(inode, iblock, &newex);
2817 if (cache_type == EXT4_EXT_CACHE_GAP) {
2818 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
2820 * block isn't allocated yet and
2821 * user doesn't want to allocate it
2825 /* we should allocate requested block */
2826 } else if (cache_type == EXT4_EXT_CACHE_EXTENT) {
2827 /* block is already allocated */
2829 - le32_to_cpu(newex.ee_block)
2830 + ext_pblock(&newex);
2831 /* number of remaining blocks in the extent */
2832 allocated = ext4_ext_get_actual_len(&newex) -
2833 (iblock - le32_to_cpu(newex.ee_block));
2840 /* find extent for this block */
2841 path = ext4_ext_find_extent(inode, iblock, NULL);
2843 err = PTR_ERR(path);
2848 depth = ext_depth(inode);
2851 * consistent leaf must not be empty;
2852 * this situation is possible, though, _during_ tree modification;
2853 * this is why assert can't be put in ext4_ext_find_extent()
2855 BUG_ON(path[depth].p_ext == NULL && depth != 0);
2856 eh = path[depth].p_hdr;
2858 ex = path[depth].p_ext;
2860 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
2861 ext4_fsblk_t ee_start = ext_pblock(ex);
2862 unsigned short ee_len;
2865 * Uninitialized extents are treated as holes, except that
2866 * we split out initialized portions during a write.
2868 ee_len = ext4_ext_get_actual_len(ex);
2869 /* if found extent covers block, simply return it */
2870 if (iblock >= ee_block && iblock < ee_block + ee_len) {
2871 newblock = iblock - ee_block + ee_start;
2872 /* number of remaining blocks in the extent */
2873 allocated = ee_len - (iblock - ee_block);
2874 ext_debug("%u fit into %u:%d -> %llu\n", iblock,
2875 ee_block, ee_len, newblock);
2877 /* Do not put uninitialized extent in the cache */
2878 if (!ext4_ext_is_uninitialized(ex)) {
2879 ext4_ext_put_in_cache(inode, ee_block,
2881 EXT4_EXT_CACHE_EXTENT);
2884 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
2886 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
2887 if (allocated > max_blocks)
2888 allocated = max_blocks;
2890 * We have blocks reserved already. We
2891 * return allocated blocks so that delalloc
2892 * won't do block reservation for us. But
2893 * the buffer head will be unmapped so that
2894 * a read from the block returns 0s.
2896 set_buffer_unwritten(bh_result);
2897 bh_result->b_bdev = inode->i_sb->s_bdev;
2898 bh_result->b_blocknr = newblock;
2902 ret = ext4_ext_convert_to_initialized(handle, inode,
2915 * requested block isn't allocated yet;
2916 * we couldn't try to create block if create flag is zero
2918 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
2920 * put just found gap into cache to speed up
2921 * subsequent requests
2923 ext4_ext_put_gap_in_cache(inode, path, iblock);
2927 * Okay, we need to do block allocation.
2930 /* find neighbour allocated blocks */
2932 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
2936 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
2941 * See if request is beyond maximum number of blocks we can have in
2942 * a single extent. For an initialized extent this limit is
2943 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
2944 * EXT_UNINIT_MAX_LEN.
2946 if (max_blocks > EXT_INIT_MAX_LEN &&
2947 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
2948 max_blocks = EXT_INIT_MAX_LEN;
2949 else if (max_blocks > EXT_UNINIT_MAX_LEN &&
2950 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
2951 max_blocks = EXT_UNINIT_MAX_LEN;
2953 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
2954 newex.ee_block = cpu_to_le32(iblock);
2955 newex.ee_len = cpu_to_le16(max_blocks);
2956 err = ext4_ext_check_overlap(inode, &newex, path);
2958 allocated = ext4_ext_get_actual_len(&newex);
2960 allocated = max_blocks;
2962 /* allocate new block */
2964 ar.goal = ext4_ext_find_goal(inode, path, iblock);
2965 ar.logical = iblock;
2967 if (S_ISREG(inode->i_mode))
2968 ar.flags = EXT4_MB_HINT_DATA;
2970 /* disable in-core preallocation for non-regular files */
2972 newblock = ext4_mb_new_blocks(handle, &ar, &err);
2975 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
2976 ar.goal, newblock, allocated);
2978 /* try to insert new extent into found leaf and return */
2979 ext4_ext_store_pblock(&newex, newblock);
2980 newex.ee_len = cpu_to_le16(ar.len);
2981 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) /* Mark uninitialized */
2982 ext4_ext_mark_uninitialized(&newex);
2983 err = ext4_ext_insert_extent(handle, inode, path, &newex);
2985 /* free data blocks we just allocated */
2986 /* not a good idea to call discard here directly,
2987 * but otherwise we'd need to call it every free() */
2988 ext4_discard_preallocations(inode);
2989 ext4_free_blocks(handle, inode, ext_pblock(&newex),
2990 ext4_ext_get_actual_len(&newex), 0);
2994 /* previous routine could use block we allocated */
2995 newblock = ext_pblock(&newex);
2996 allocated = ext4_ext_get_actual_len(&newex);
2998 set_buffer_new(bh_result);
3000 /* Cache only when it is _not_ an uninitialized extent */
3001 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
3002 ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
3003 EXT4_EXT_CACHE_EXTENT);
3005 if (allocated > max_blocks)
3006 allocated = max_blocks;
3007 ext4_ext_show_leaf(inode, path);
3008 set_buffer_mapped(bh_result);
3009 bh_result->b_bdev = inode->i_sb->s_bdev;
3010 bh_result->b_blocknr = newblock;
3013 ext4_ext_drop_refs(path);
3016 return err ? err : allocated;
3019 void ext4_ext_truncate(struct inode *inode)
3021 struct address_space *mapping = inode->i_mapping;
3022 struct super_block *sb = inode->i_sb;
3023 ext4_lblk_t last_block;
3028 * probably first extent we're gonna free will be last in block
3030 err = ext4_writepage_trans_blocks(inode);
3031 handle = ext4_journal_start(inode, err);
3035 if (inode->i_size & (sb->s_blocksize - 1))
3036 ext4_block_truncate_page(handle, mapping, inode->i_size);
3038 if (ext4_orphan_add(handle, inode))
3041 down_write(&EXT4_I(inode)->i_data_sem);
3042 ext4_ext_invalidate_cache(inode);
3044 ext4_discard_preallocations(inode);
3047 * TODO: optimization is possible here.
3048 * Probably we need not scan at all,
3049 * because page truncation is enough.
3052 /* we have to know where to truncate from in crash case */
3053 EXT4_I(inode)->i_disksize = inode->i_size;
3054 ext4_mark_inode_dirty(handle, inode);
3056 last_block = (inode->i_size + sb->s_blocksize - 1)
3057 >> EXT4_BLOCK_SIZE_BITS(sb);
3058 err = ext4_ext_remove_space(inode, last_block);
3060 /* In a multi-transaction truncate, we only make the final
3061 * transaction synchronous.
3064 ext4_handle_sync(handle);
3067 up_write(&EXT4_I(inode)->i_data_sem);
3069 * If this was a simple ftruncate() and the file will remain alive,
3070 * then we need to clear up the orphan record which we created above.
3071 * However, if this was a real unlink then we were called by
3072 * ext4_delete_inode(), and we allow that function to clean up the
3073 * orphan info for us.
3076 ext4_orphan_del(handle, inode);
3078 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3079 ext4_mark_inode_dirty(handle, inode);
3080 ext4_journal_stop(handle);
3083 static void ext4_falloc_update_inode(struct inode *inode,
3084 int mode, loff_t new_size, int update_ctime)
3086 struct timespec now;
3089 now = current_fs_time(inode->i_sb);
3090 if (!timespec_equal(&inode->i_ctime, &now))
3091 inode->i_ctime = now;
3094 * Update only when preallocation was requested beyond
3097 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
3098 if (new_size > i_size_read(inode))
3099 i_size_write(inode, new_size);
3100 if (new_size > EXT4_I(inode)->i_disksize)
3101 ext4_update_i_disksize(inode, new_size);
3107 * preallocate space for a file. This implements ext4's fallocate inode
3108 * operation, which gets called from sys_fallocate system call.
3109 * For block-mapped files, posix_fallocate should fall back to the method
3110 * of writing zeroes to the required new blocks (the same behavior which is
3111 * expected for file systems which do not support fallocate() system call).
3113 long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
3118 unsigned int max_blocks;
3122 struct buffer_head map_bh;
3123 unsigned int credits, blkbits = inode->i_blkbits;
3126 * currently supporting (pre)allocate mode for extent-based
3129 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
3132 /* preallocation to directories is currently not supported */
3133 if (S_ISDIR(inode->i_mode))
3136 block = offset >> blkbits;
3138 * We can't just convert len to max_blocks because
3139 * If blocksize = 4096 offset = 3072 and len = 2048
3141 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
3144 * credits to insert 1 extent into extent tree
3146 credits = ext4_chunk_trans_blocks(inode, max_blocks);
3147 mutex_lock(&inode->i_mutex);
3149 while (ret >= 0 && ret < max_blocks) {
3150 block = block + ret;
3151 max_blocks = max_blocks - ret;
3152 handle = ext4_journal_start(inode, credits);
3153 if (IS_ERR(handle)) {
3154 ret = PTR_ERR(handle);
3158 ret = ext4_get_blocks(handle, inode, block,
3159 max_blocks, &map_bh,
3160 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT);
3164 printk(KERN_ERR "%s: ext4_ext_get_blocks "
3165 "returned error inode#%lu, block=%u, "
3166 "max_blocks=%u", __func__,
3167 inode->i_ino, block, max_blocks);
3169 ext4_mark_inode_dirty(handle, inode);
3170 ret2 = ext4_journal_stop(handle);
3173 if ((block + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
3174 blkbits) >> blkbits))
3175 new_size = offset + len;
3177 new_size = (block + ret) << blkbits;
3179 ext4_falloc_update_inode(inode, mode, new_size,
3180 buffer_new(&map_bh));
3181 ext4_mark_inode_dirty(handle, inode);
3182 ret2 = ext4_journal_stop(handle);
3186 if (ret == -ENOSPC &&
3187 ext4_should_retry_alloc(inode->i_sb, &retries)) {
3191 mutex_unlock(&inode->i_mutex);
3192 return ret > 0 ? ret2 : ret;
3196 * Callback function called for each extent to gather FIEMAP information.
3198 static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path,
3199 struct ext4_ext_cache *newex, struct ext4_extent *ex,
3202 struct fiemap_extent_info *fieinfo = data;
3203 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
3210 logical = (__u64)newex->ec_block << blksize_bits;
3212 if (newex->ec_type == EXT4_EXT_CACHE_GAP) {
3215 struct buffer_head *bh = NULL;
3217 offset = logical >> PAGE_SHIFT;
3218 page = find_get_page(inode->i_mapping, offset);
3219 if (!page || !page_has_buffers(page))
3220 return EXT_CONTINUE;
3222 bh = page_buffers(page);
3225 return EXT_CONTINUE;
3227 if (buffer_delay(bh)) {
3228 flags |= FIEMAP_EXTENT_DELALLOC;
3229 page_cache_release(page);
3231 page_cache_release(page);
3232 return EXT_CONTINUE;
3236 physical = (__u64)newex->ec_start << blksize_bits;
3237 length = (__u64)newex->ec_len << blksize_bits;
3239 if (ex && ext4_ext_is_uninitialized(ex))
3240 flags |= FIEMAP_EXTENT_UNWRITTEN;
3243 * If this extent reaches EXT_MAX_BLOCK, it must be last.
3245 * Or if ext4_ext_next_allocated_block is EXT_MAX_BLOCK,
3246 * this also indicates no more allocated blocks.
3248 * XXX this might miss a single-block extent at EXT_MAX_BLOCK
3250 if (ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK ||
3251 newex->ec_block + newex->ec_len - 1 == EXT_MAX_BLOCK) {
3252 loff_t size = i_size_read(inode);
3253 loff_t bs = EXT4_BLOCK_SIZE(inode->i_sb);
3255 flags |= FIEMAP_EXTENT_LAST;
3256 if ((flags & FIEMAP_EXTENT_DELALLOC) &&
3257 logical+length > size)
3258 length = (size - logical + bs - 1) & ~(bs-1);
3261 error = fiemap_fill_next_extent(fieinfo, logical, physical,
3268 return EXT_CONTINUE;
3271 /* fiemap flags we can handle specified here */
3272 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
3274 static int ext4_xattr_fiemap(struct inode *inode,
3275 struct fiemap_extent_info *fieinfo)
3279 __u32 flags = FIEMAP_EXTENT_LAST;
3280 int blockbits = inode->i_sb->s_blocksize_bits;
3284 if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
3285 struct ext4_iloc iloc;
3286 int offset; /* offset of xattr in inode */
3288 error = ext4_get_inode_loc(inode, &iloc);
3291 physical = iloc.bh->b_blocknr << blockbits;
3292 offset = EXT4_GOOD_OLD_INODE_SIZE +
3293 EXT4_I(inode)->i_extra_isize;
3295 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
3296 flags |= FIEMAP_EXTENT_DATA_INLINE;
3297 } else { /* external block */
3298 physical = EXT4_I(inode)->i_file_acl << blockbits;
3299 length = inode->i_sb->s_blocksize;
3303 error = fiemap_fill_next_extent(fieinfo, 0, physical,
3305 return (error < 0 ? error : 0);
3308 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3309 __u64 start, __u64 len)
3311 ext4_lblk_t start_blk;
3312 ext4_lblk_t len_blks;
3315 /* fallback to generic here if not in extents fmt */
3316 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
3317 return generic_block_fiemap(inode, fieinfo, start, len,
3320 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
3323 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
3324 error = ext4_xattr_fiemap(inode, fieinfo);
3326 start_blk = start >> inode->i_sb->s_blocksize_bits;
3327 len_blks = len >> inode->i_sb->s_blocksize_bits;
3330 * Walk the extent tree gathering extent information.
3331 * ext4_ext_fiemap_cb will push extents back to user.
3333 down_read(&EXT4_I(inode)->i_data_sem);
3334 error = ext4_ext_walk_space(inode, start_blk, len_blks,
3335 ext4_ext_fiemap_cb, fieinfo);
3336 up_read(&EXT4_I(inode)->i_data_sem);