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"
47 #include <trace/events/ext4.h>
49 static int ext4_split_extent(handle_t
*handle
,
51 struct ext4_ext_path
*path
,
52 struct ext4_map_blocks
*map
,
56 static int ext4_ext_truncate_extend_restart(handle_t
*handle
,
62 if (!ext4_handle_valid(handle
))
64 if (handle
->h_buffer_credits
> needed
)
66 err
= ext4_journal_extend(handle
, needed
);
69 err
= ext4_truncate_restart_trans(handle
, inode
, needed
);
81 static int ext4_ext_get_access(handle_t
*handle
, struct inode
*inode
,
82 struct ext4_ext_path
*path
)
85 /* path points to block */
86 return ext4_journal_get_write_access(handle
, path
->p_bh
);
88 /* path points to leaf/index in inode body */
89 /* we use in-core data, no need to protect them */
99 #define ext4_ext_dirty(handle, inode, path) \
100 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
101 static int __ext4_ext_dirty(const char *where
, unsigned int line
,
102 handle_t
*handle
, struct inode
*inode
,
103 struct ext4_ext_path
*path
)
107 /* path points to block */
108 err
= __ext4_handle_dirty_metadata(where
, line
, handle
,
111 /* path points to leaf/index in inode body */
112 err
= ext4_mark_inode_dirty(handle
, inode
);
117 static ext4_fsblk_t
ext4_ext_find_goal(struct inode
*inode
,
118 struct ext4_ext_path
*path
,
124 struct ext4_extent
*ex
;
125 depth
= path
->p_depth
;
128 * Try to predict block placement assuming that we are
129 * filling in a file which will eventually be
130 * non-sparse --- i.e., in the case of libbfd writing
131 * an ELF object sections out-of-order but in a way
132 * the eventually results in a contiguous object or
133 * executable file, or some database extending a table
134 * space file. However, this is actually somewhat
135 * non-ideal if we are writing a sparse file such as
136 * qemu or KVM writing a raw image file that is going
137 * to stay fairly sparse, since it will end up
138 * fragmenting the file system's free space. Maybe we
139 * should have some hueristics or some way to allow
140 * userspace to pass a hint to file system,
141 * especially if the latter case turns out to be
144 ex
= path
[depth
].p_ext
;
146 ext4_fsblk_t ext_pblk
= ext4_ext_pblock(ex
);
147 ext4_lblk_t ext_block
= le32_to_cpu(ex
->ee_block
);
149 if (block
> ext_block
)
150 return ext_pblk
+ (block
- ext_block
);
152 return ext_pblk
- (ext_block
- block
);
155 /* it looks like index is empty;
156 * try to find starting block from index itself */
157 if (path
[depth
].p_bh
)
158 return path
[depth
].p_bh
->b_blocknr
;
161 /* OK. use inode's group */
162 return ext4_inode_to_goal_block(inode
);
166 * Allocation for a meta data block
169 ext4_ext_new_meta_block(handle_t
*handle
, struct inode
*inode
,
170 struct ext4_ext_path
*path
,
171 struct ext4_extent
*ex
, int *err
, unsigned int flags
)
173 ext4_fsblk_t goal
, newblock
;
175 goal
= ext4_ext_find_goal(inode
, path
, le32_to_cpu(ex
->ee_block
));
176 newblock
= ext4_new_meta_blocks(handle
, inode
, goal
, flags
,
181 static inline int ext4_ext_space_block(struct inode
*inode
, int check
)
185 size
= (inode
->i_sb
->s_blocksize
- sizeof(struct ext4_extent_header
))
186 / sizeof(struct ext4_extent
);
188 #ifdef AGGRESSIVE_TEST
196 static inline int ext4_ext_space_block_idx(struct inode
*inode
, int check
)
200 size
= (inode
->i_sb
->s_blocksize
- sizeof(struct ext4_extent_header
))
201 / sizeof(struct ext4_extent_idx
);
203 #ifdef AGGRESSIVE_TEST
211 static inline int ext4_ext_space_root(struct inode
*inode
, int check
)
215 size
= sizeof(EXT4_I(inode
)->i_data
);
216 size
-= sizeof(struct ext4_extent_header
);
217 size
/= sizeof(struct ext4_extent
);
219 #ifdef AGGRESSIVE_TEST
227 static inline int ext4_ext_space_root_idx(struct inode
*inode
, int check
)
231 size
= sizeof(EXT4_I(inode
)->i_data
);
232 size
-= sizeof(struct ext4_extent_header
);
233 size
/= sizeof(struct ext4_extent_idx
);
235 #ifdef AGGRESSIVE_TEST
244 * Calculate the number of metadata blocks needed
245 * to allocate @blocks
246 * Worse case is one block per extent
248 int ext4_ext_calc_metadata_amount(struct inode
*inode
, ext4_lblk_t lblock
)
250 struct ext4_inode_info
*ei
= EXT4_I(inode
);
253 idxs
= ((inode
->i_sb
->s_blocksize
- sizeof(struct ext4_extent_header
))
254 / sizeof(struct ext4_extent_idx
));
257 * If the new delayed allocation block is contiguous with the
258 * previous da block, it can share index blocks with the
259 * previous block, so we only need to allocate a new index
260 * block every idxs leaf blocks. At ldxs**2 blocks, we need
261 * an additional index block, and at ldxs**3 blocks, yet
262 * another index blocks.
264 if (ei
->i_da_metadata_calc_len
&&
265 ei
->i_da_metadata_calc_last_lblock
+1 == lblock
) {
266 if ((ei
->i_da_metadata_calc_len
% idxs
) == 0)
268 if ((ei
->i_da_metadata_calc_len
% (idxs
*idxs
)) == 0)
270 if ((ei
->i_da_metadata_calc_len
% (idxs
*idxs
*idxs
)) == 0) {
272 ei
->i_da_metadata_calc_len
= 0;
274 ei
->i_da_metadata_calc_len
++;
275 ei
->i_da_metadata_calc_last_lblock
++;
280 * In the worst case we need a new set of index blocks at
281 * every level of the inode's extent tree.
283 ei
->i_da_metadata_calc_len
= 1;
284 ei
->i_da_metadata_calc_last_lblock
= lblock
;
285 return ext_depth(inode
) + 1;
289 ext4_ext_max_entries(struct inode
*inode
, int depth
)
293 if (depth
== ext_depth(inode
)) {
295 max
= ext4_ext_space_root(inode
, 1);
297 max
= ext4_ext_space_root_idx(inode
, 1);
300 max
= ext4_ext_space_block(inode
, 1);
302 max
= ext4_ext_space_block_idx(inode
, 1);
308 static int ext4_valid_extent(struct inode
*inode
, struct ext4_extent
*ext
)
310 ext4_fsblk_t block
= ext4_ext_pblock(ext
);
311 int len
= ext4_ext_get_actual_len(ext
);
313 return ext4_data_block_valid(EXT4_SB(inode
->i_sb
), block
, len
);
316 static int ext4_valid_extent_idx(struct inode
*inode
,
317 struct ext4_extent_idx
*ext_idx
)
319 ext4_fsblk_t block
= ext4_idx_pblock(ext_idx
);
321 return ext4_data_block_valid(EXT4_SB(inode
->i_sb
), block
, 1);
324 static int ext4_valid_extent_entries(struct inode
*inode
,
325 struct ext4_extent_header
*eh
,
328 struct ext4_extent
*ext
;
329 struct ext4_extent_idx
*ext_idx
;
330 unsigned short entries
;
331 if (eh
->eh_entries
== 0)
334 entries
= le16_to_cpu(eh
->eh_entries
);
338 ext
= EXT_FIRST_EXTENT(eh
);
340 if (!ext4_valid_extent(inode
, ext
))
346 ext_idx
= EXT_FIRST_INDEX(eh
);
348 if (!ext4_valid_extent_idx(inode
, ext_idx
))
357 static int __ext4_ext_check(const char *function
, unsigned int line
,
358 struct inode
*inode
, struct ext4_extent_header
*eh
,
361 const char *error_msg
;
364 if (unlikely(eh
->eh_magic
!= EXT4_EXT_MAGIC
)) {
365 error_msg
= "invalid magic";
368 if (unlikely(le16_to_cpu(eh
->eh_depth
) != depth
)) {
369 error_msg
= "unexpected eh_depth";
372 if (unlikely(eh
->eh_max
== 0)) {
373 error_msg
= "invalid eh_max";
376 max
= ext4_ext_max_entries(inode
, depth
);
377 if (unlikely(le16_to_cpu(eh
->eh_max
) > max
)) {
378 error_msg
= "too large eh_max";
381 if (unlikely(le16_to_cpu(eh
->eh_entries
) > le16_to_cpu(eh
->eh_max
))) {
382 error_msg
= "invalid eh_entries";
385 if (!ext4_valid_extent_entries(inode
, eh
, depth
)) {
386 error_msg
= "invalid extent entries";
392 ext4_error_inode(inode
, function
, line
, 0,
393 "bad header/extent: %s - magic %x, "
394 "entries %u, max %u(%u), depth %u(%u)",
395 error_msg
, le16_to_cpu(eh
->eh_magic
),
396 le16_to_cpu(eh
->eh_entries
), le16_to_cpu(eh
->eh_max
),
397 max
, le16_to_cpu(eh
->eh_depth
), depth
);
402 #define ext4_ext_check(inode, eh, depth) \
403 __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
405 int ext4_ext_check_inode(struct inode
*inode
)
407 return ext4_ext_check(inode
, ext_inode_hdr(inode
), ext_depth(inode
));
411 static void ext4_ext_show_path(struct inode
*inode
, struct ext4_ext_path
*path
)
413 int k
, l
= path
->p_depth
;
416 for (k
= 0; k
<= l
; k
++, path
++) {
418 ext_debug(" %d->%llu", le32_to_cpu(path
->p_idx
->ei_block
),
419 ext4_idx_pblock(path
->p_idx
));
420 } else if (path
->p_ext
) {
421 ext_debug(" %d:[%d]%d:%llu ",
422 le32_to_cpu(path
->p_ext
->ee_block
),
423 ext4_ext_is_uninitialized(path
->p_ext
),
424 ext4_ext_get_actual_len(path
->p_ext
),
425 ext4_ext_pblock(path
->p_ext
));
432 static void ext4_ext_show_leaf(struct inode
*inode
, struct ext4_ext_path
*path
)
434 int depth
= ext_depth(inode
);
435 struct ext4_extent_header
*eh
;
436 struct ext4_extent
*ex
;
442 eh
= path
[depth
].p_hdr
;
443 ex
= EXT_FIRST_EXTENT(eh
);
445 ext_debug("Displaying leaf extents for inode %lu\n", inode
->i_ino
);
447 for (i
= 0; i
< le16_to_cpu(eh
->eh_entries
); i
++, ex
++) {
448 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex
->ee_block
),
449 ext4_ext_is_uninitialized(ex
),
450 ext4_ext_get_actual_len(ex
), ext4_ext_pblock(ex
));
455 static void ext4_ext_show_move(struct inode
*inode
, struct ext4_ext_path
*path
,
456 ext4_fsblk_t newblock
, int level
)
458 int depth
= ext_depth(inode
);
459 struct ext4_extent
*ex
;
461 if (depth
!= level
) {
462 struct ext4_extent_idx
*idx
;
463 idx
= path
[level
].p_idx
;
464 while (idx
<= EXT_MAX_INDEX(path
[level
].p_hdr
)) {
465 ext_debug("%d: move %d:%llu in new index %llu\n", level
,
466 le32_to_cpu(idx
->ei_block
),
467 ext4_idx_pblock(idx
),
475 ex
= path
[depth
].p_ext
;
476 while (ex
<= EXT_MAX_EXTENT(path
[depth
].p_hdr
)) {
477 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
478 le32_to_cpu(ex
->ee_block
),
480 ext4_ext_is_uninitialized(ex
),
481 ext4_ext_get_actual_len(ex
),
488 #define ext4_ext_show_path(inode, path)
489 #define ext4_ext_show_leaf(inode, path)
490 #define ext4_ext_show_move(inode, path, newblock, level)
493 void ext4_ext_drop_refs(struct ext4_ext_path
*path
)
495 int depth
= path
->p_depth
;
498 for (i
= 0; i
<= depth
; i
++, path
++)
506 * ext4_ext_binsearch_idx:
507 * binary search for the closest index of the given block
508 * the header must be checked before calling this
511 ext4_ext_binsearch_idx(struct inode
*inode
,
512 struct ext4_ext_path
*path
, ext4_lblk_t block
)
514 struct ext4_extent_header
*eh
= path
->p_hdr
;
515 struct ext4_extent_idx
*r
, *l
, *m
;
518 ext_debug("binsearch for %u(idx): ", block
);
520 l
= EXT_FIRST_INDEX(eh
) + 1;
521 r
= EXT_LAST_INDEX(eh
);
524 if (block
< le32_to_cpu(m
->ei_block
))
528 ext_debug("%p(%u):%p(%u):%p(%u) ", l
, le32_to_cpu(l
->ei_block
),
529 m
, le32_to_cpu(m
->ei_block
),
530 r
, le32_to_cpu(r
->ei_block
));
534 ext_debug(" -> %d->%lld ", le32_to_cpu(path
->p_idx
->ei_block
),
535 ext4_idx_pblock(path
->p_idx
));
537 #ifdef CHECK_BINSEARCH
539 struct ext4_extent_idx
*chix
, *ix
;
542 chix
= ix
= EXT_FIRST_INDEX(eh
);
543 for (k
= 0; k
< le16_to_cpu(eh
->eh_entries
); k
++, ix
++) {
545 le32_to_cpu(ix
->ei_block
) <= le32_to_cpu(ix
[-1].ei_block
)) {
546 printk(KERN_DEBUG
"k=%d, ix=0x%p, "
548 ix
, EXT_FIRST_INDEX(eh
));
549 printk(KERN_DEBUG
"%u <= %u\n",
550 le32_to_cpu(ix
->ei_block
),
551 le32_to_cpu(ix
[-1].ei_block
));
553 BUG_ON(k
&& le32_to_cpu(ix
->ei_block
)
554 <= le32_to_cpu(ix
[-1].ei_block
));
555 if (block
< le32_to_cpu(ix
->ei_block
))
559 BUG_ON(chix
!= path
->p_idx
);
566 * ext4_ext_binsearch:
567 * binary search for closest extent of the given block
568 * the header must be checked before calling this
571 ext4_ext_binsearch(struct inode
*inode
,
572 struct ext4_ext_path
*path
, ext4_lblk_t block
)
574 struct ext4_extent_header
*eh
= path
->p_hdr
;
575 struct ext4_extent
*r
, *l
, *m
;
577 if (eh
->eh_entries
== 0) {
579 * this leaf is empty:
580 * we get such a leaf in split/add case
585 ext_debug("binsearch for %u: ", block
);
587 l
= EXT_FIRST_EXTENT(eh
) + 1;
588 r
= EXT_LAST_EXTENT(eh
);
592 if (block
< le32_to_cpu(m
->ee_block
))
596 ext_debug("%p(%u):%p(%u):%p(%u) ", l
, le32_to_cpu(l
->ee_block
),
597 m
, le32_to_cpu(m
->ee_block
),
598 r
, le32_to_cpu(r
->ee_block
));
602 ext_debug(" -> %d:%llu:[%d]%d ",
603 le32_to_cpu(path
->p_ext
->ee_block
),
604 ext4_ext_pblock(path
->p_ext
),
605 ext4_ext_is_uninitialized(path
->p_ext
),
606 ext4_ext_get_actual_len(path
->p_ext
));
608 #ifdef CHECK_BINSEARCH
610 struct ext4_extent
*chex
, *ex
;
613 chex
= ex
= EXT_FIRST_EXTENT(eh
);
614 for (k
= 0; k
< le16_to_cpu(eh
->eh_entries
); k
++, ex
++) {
615 BUG_ON(k
&& le32_to_cpu(ex
->ee_block
)
616 <= le32_to_cpu(ex
[-1].ee_block
));
617 if (block
< le32_to_cpu(ex
->ee_block
))
621 BUG_ON(chex
!= path
->p_ext
);
627 int ext4_ext_tree_init(handle_t
*handle
, struct inode
*inode
)
629 struct ext4_extent_header
*eh
;
631 eh
= ext_inode_hdr(inode
);
634 eh
->eh_magic
= EXT4_EXT_MAGIC
;
635 eh
->eh_max
= cpu_to_le16(ext4_ext_space_root(inode
, 0));
636 ext4_mark_inode_dirty(handle
, inode
);
637 ext4_ext_invalidate_cache(inode
);
641 struct ext4_ext_path
*
642 ext4_ext_find_extent(struct inode
*inode
, ext4_lblk_t block
,
643 struct ext4_ext_path
*path
)
645 struct ext4_extent_header
*eh
;
646 struct buffer_head
*bh
;
647 short int depth
, i
, ppos
= 0, alloc
= 0;
649 eh
= ext_inode_hdr(inode
);
650 depth
= ext_depth(inode
);
652 /* account possible depth increase */
654 path
= kzalloc(sizeof(struct ext4_ext_path
) * (depth
+ 2),
657 return ERR_PTR(-ENOMEM
);
664 /* walk through the tree */
666 int need_to_validate
= 0;
668 ext_debug("depth %d: num %d, max %d\n",
669 ppos
, le16_to_cpu(eh
->eh_entries
), le16_to_cpu(eh
->eh_max
));
671 ext4_ext_binsearch_idx(inode
, path
+ ppos
, block
);
672 path
[ppos
].p_block
= ext4_idx_pblock(path
[ppos
].p_idx
);
673 path
[ppos
].p_depth
= i
;
674 path
[ppos
].p_ext
= NULL
;
676 bh
= sb_getblk(inode
->i_sb
, path
[ppos
].p_block
);
679 if (!bh_uptodate_or_lock(bh
)) {
680 trace_ext4_ext_load_extent(inode
, block
,
682 if (bh_submit_read(bh
) < 0) {
686 /* validate the extent entries */
687 need_to_validate
= 1;
689 eh
= ext_block_hdr(bh
);
691 if (unlikely(ppos
> depth
)) {
693 EXT4_ERROR_INODE(inode
,
694 "ppos %d > depth %d", ppos
, depth
);
697 path
[ppos
].p_bh
= bh
;
698 path
[ppos
].p_hdr
= eh
;
701 if (need_to_validate
&& ext4_ext_check(inode
, eh
, i
))
705 path
[ppos
].p_depth
= i
;
706 path
[ppos
].p_ext
= NULL
;
707 path
[ppos
].p_idx
= NULL
;
710 ext4_ext_binsearch(inode
, path
+ ppos
, block
);
711 /* if not an empty leaf */
712 if (path
[ppos
].p_ext
)
713 path
[ppos
].p_block
= ext4_ext_pblock(path
[ppos
].p_ext
);
715 ext4_ext_show_path(inode
, path
);
720 ext4_ext_drop_refs(path
);
723 return ERR_PTR(-EIO
);
727 * ext4_ext_insert_index:
728 * insert new index [@logical;@ptr] into the block at @curp;
729 * check where to insert: before @curp or after @curp
731 static int ext4_ext_insert_index(handle_t
*handle
, struct inode
*inode
,
732 struct ext4_ext_path
*curp
,
733 int logical
, ext4_fsblk_t ptr
)
735 struct ext4_extent_idx
*ix
;
738 err
= ext4_ext_get_access(handle
, inode
, curp
);
742 if (unlikely(logical
== le32_to_cpu(curp
->p_idx
->ei_block
))) {
743 EXT4_ERROR_INODE(inode
,
744 "logical %d == ei_block %d!",
745 logical
, le32_to_cpu(curp
->p_idx
->ei_block
));
749 if (unlikely(le16_to_cpu(curp
->p_hdr
->eh_entries
)
750 >= le16_to_cpu(curp
->p_hdr
->eh_max
))) {
751 EXT4_ERROR_INODE(inode
,
752 "eh_entries %d >= eh_max %d!",
753 le16_to_cpu(curp
->p_hdr
->eh_entries
),
754 le16_to_cpu(curp
->p_hdr
->eh_max
));
758 len
= EXT_MAX_INDEX(curp
->p_hdr
) - curp
->p_idx
;
759 if (logical
> le32_to_cpu(curp
->p_idx
->ei_block
)) {
761 if (curp
->p_idx
!= EXT_LAST_INDEX(curp
->p_hdr
)) {
762 len
= (len
- 1) * sizeof(struct ext4_extent_idx
);
763 len
= len
< 0 ? 0 : len
;
764 ext_debug("insert new index %d after: %llu. "
765 "move %d from 0x%p to 0x%p\n",
767 (curp
->p_idx
+ 1), (curp
->p_idx
+ 2));
768 memmove(curp
->p_idx
+ 2, curp
->p_idx
+ 1, len
);
770 ix
= curp
->p_idx
+ 1;
773 len
= len
* sizeof(struct ext4_extent_idx
);
774 len
= len
< 0 ? 0 : len
;
775 ext_debug("insert new index %d before: %llu. "
776 "move %d from 0x%p to 0x%p\n",
778 curp
->p_idx
, (curp
->p_idx
+ 1));
779 memmove(curp
->p_idx
+ 1, curp
->p_idx
, len
);
783 ix
->ei_block
= cpu_to_le32(logical
);
784 ext4_idx_store_pblock(ix
, ptr
);
785 le16_add_cpu(&curp
->p_hdr
->eh_entries
, 1);
787 if (unlikely(ix
> EXT_LAST_INDEX(curp
->p_hdr
))) {
788 EXT4_ERROR_INODE(inode
, "ix > EXT_LAST_INDEX!");
792 err
= ext4_ext_dirty(handle
, inode
, curp
);
793 ext4_std_error(inode
->i_sb
, err
);
800 * inserts new subtree into the path, using free index entry
802 * - allocates all needed blocks (new leaf and all intermediate index blocks)
803 * - makes decision where to split
804 * - moves remaining extents and index entries (right to the split point)
805 * into the newly allocated blocks
806 * - initializes subtree
808 static int ext4_ext_split(handle_t
*handle
, struct inode
*inode
,
810 struct ext4_ext_path
*path
,
811 struct ext4_extent
*newext
, int at
)
813 struct buffer_head
*bh
= NULL
;
814 int depth
= ext_depth(inode
);
815 struct ext4_extent_header
*neh
;
816 struct ext4_extent_idx
*fidx
;
818 ext4_fsblk_t newblock
, oldblock
;
820 ext4_fsblk_t
*ablocks
= NULL
; /* array of allocated blocks */
823 /* make decision: where to split? */
824 /* FIXME: now decision is simplest: at current extent */
826 /* if current leaf will be split, then we should use
827 * border from split point */
828 if (unlikely(path
[depth
].p_ext
> EXT_MAX_EXTENT(path
[depth
].p_hdr
))) {
829 EXT4_ERROR_INODE(inode
, "p_ext > EXT_MAX_EXTENT!");
832 if (path
[depth
].p_ext
!= EXT_MAX_EXTENT(path
[depth
].p_hdr
)) {
833 border
= path
[depth
].p_ext
[1].ee_block
;
834 ext_debug("leaf will be split."
835 " next leaf starts at %d\n",
836 le32_to_cpu(border
));
838 border
= newext
->ee_block
;
839 ext_debug("leaf will be added."
840 " next leaf starts at %d\n",
841 le32_to_cpu(border
));
845 * If error occurs, then we break processing
846 * and mark filesystem read-only. index won't
847 * be inserted and tree will be in consistent
848 * state. Next mount will repair buffers too.
852 * Get array to track all allocated blocks.
853 * We need this to handle errors and free blocks
856 ablocks
= kzalloc(sizeof(ext4_fsblk_t
) * depth
, GFP_NOFS
);
860 /* allocate all needed blocks */
861 ext_debug("allocate %d blocks for indexes/leaf\n", depth
- at
);
862 for (a
= 0; a
< depth
- at
; a
++) {
863 newblock
= ext4_ext_new_meta_block(handle
, inode
, path
,
864 newext
, &err
, flags
);
867 ablocks
[a
] = newblock
;
870 /* initialize new leaf */
871 newblock
= ablocks
[--a
];
872 if (unlikely(newblock
== 0)) {
873 EXT4_ERROR_INODE(inode
, "newblock == 0!");
877 bh
= sb_getblk(inode
->i_sb
, newblock
);
884 err
= ext4_journal_get_create_access(handle
, bh
);
888 neh
= ext_block_hdr(bh
);
890 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block(inode
, 0));
891 neh
->eh_magic
= EXT4_EXT_MAGIC
;
894 /* move remainder of path[depth] to the new leaf */
895 if (unlikely(path
[depth
].p_hdr
->eh_entries
!=
896 path
[depth
].p_hdr
->eh_max
)) {
897 EXT4_ERROR_INODE(inode
, "eh_entries %d != eh_max %d!",
898 path
[depth
].p_hdr
->eh_entries
,
899 path
[depth
].p_hdr
->eh_max
);
903 /* start copy from next extent */
904 m
= EXT_MAX_EXTENT(path
[depth
].p_hdr
) - path
[depth
].p_ext
++;
905 ext4_ext_show_move(inode
, path
, newblock
, depth
);
907 struct ext4_extent
*ex
;
908 ex
= EXT_FIRST_EXTENT(neh
);
909 memmove(ex
, path
[depth
].p_ext
, sizeof(struct ext4_extent
) * m
);
910 le16_add_cpu(&neh
->eh_entries
, m
);
913 set_buffer_uptodate(bh
);
916 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
922 /* correct old leaf */
924 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
927 le16_add_cpu(&path
[depth
].p_hdr
->eh_entries
, -m
);
928 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
934 /* create intermediate indexes */
936 if (unlikely(k
< 0)) {
937 EXT4_ERROR_INODE(inode
, "k %d < 0!", k
);
942 ext_debug("create %d intermediate indices\n", k
);
943 /* insert new index into current index block */
944 /* current depth stored in i var */
948 newblock
= ablocks
[--a
];
949 bh
= sb_getblk(inode
->i_sb
, newblock
);
956 err
= ext4_journal_get_create_access(handle
, bh
);
960 neh
= ext_block_hdr(bh
);
961 neh
->eh_entries
= cpu_to_le16(1);
962 neh
->eh_magic
= EXT4_EXT_MAGIC
;
963 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block_idx(inode
, 0));
964 neh
->eh_depth
= cpu_to_le16(depth
- i
);
965 fidx
= EXT_FIRST_INDEX(neh
);
966 fidx
->ei_block
= border
;
967 ext4_idx_store_pblock(fidx
, oldblock
);
969 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
970 i
, newblock
, le32_to_cpu(border
), oldblock
);
972 /* move remainder of path[i] to the new index block */
973 if (unlikely(EXT_MAX_INDEX(path
[i
].p_hdr
) !=
974 EXT_LAST_INDEX(path
[i
].p_hdr
))) {
975 EXT4_ERROR_INODE(inode
,
976 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
977 le32_to_cpu(path
[i
].p_ext
->ee_block
));
981 /* start copy indexes */
982 m
= EXT_MAX_INDEX(path
[i
].p_hdr
) - path
[i
].p_idx
++;
983 ext_debug("cur 0x%p, last 0x%p\n", path
[i
].p_idx
,
984 EXT_MAX_INDEX(path
[i
].p_hdr
));
985 ext4_ext_show_move(inode
, path
, newblock
, i
);
987 memmove(++fidx
, path
[i
].p_idx
,
988 sizeof(struct ext4_extent_idx
) * m
);
989 le16_add_cpu(&neh
->eh_entries
, m
);
991 set_buffer_uptodate(bh
);
994 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1000 /* correct old index */
1002 err
= ext4_ext_get_access(handle
, inode
, path
+ i
);
1005 le16_add_cpu(&path
[i
].p_hdr
->eh_entries
, -m
);
1006 err
= ext4_ext_dirty(handle
, inode
, path
+ i
);
1014 /* insert new index */
1015 err
= ext4_ext_insert_index(handle
, inode
, path
+ at
,
1016 le32_to_cpu(border
), newblock
);
1020 if (buffer_locked(bh
))
1026 /* free all allocated blocks in error case */
1027 for (i
= 0; i
< depth
; i
++) {
1030 ext4_free_blocks(handle
, inode
, NULL
, ablocks
[i
], 1,
1031 EXT4_FREE_BLOCKS_METADATA
);
1040 * ext4_ext_grow_indepth:
1041 * implements tree growing procedure:
1042 * - allocates new block
1043 * - moves top-level data (index block or leaf) into the new block
1044 * - initializes new top-level, creating index that points to the
1045 * just created block
1047 static int ext4_ext_grow_indepth(handle_t
*handle
, struct inode
*inode
,
1049 struct ext4_ext_path
*path
,
1050 struct ext4_extent
*newext
)
1052 struct ext4_ext_path
*curp
= path
;
1053 struct ext4_extent_header
*neh
;
1054 struct buffer_head
*bh
;
1055 ext4_fsblk_t newblock
;
1058 newblock
= ext4_ext_new_meta_block(handle
, inode
, path
,
1059 newext
, &err
, flags
);
1063 bh
= sb_getblk(inode
->i_sb
, newblock
);
1066 ext4_std_error(inode
->i_sb
, err
);
1071 err
= ext4_journal_get_create_access(handle
, bh
);
1077 /* move top-level index/leaf into new block */
1078 memmove(bh
->b_data
, curp
->p_hdr
, sizeof(EXT4_I(inode
)->i_data
));
1080 /* set size of new block */
1081 neh
= ext_block_hdr(bh
);
1082 /* old root could have indexes or leaves
1083 * so calculate e_max right way */
1084 if (ext_depth(inode
))
1085 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block_idx(inode
, 0));
1087 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block(inode
, 0));
1088 neh
->eh_magic
= EXT4_EXT_MAGIC
;
1089 set_buffer_uptodate(bh
);
1092 err
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
1096 /* create index in new top-level index: num,max,pointer */
1097 err
= ext4_ext_get_access(handle
, inode
, curp
);
1101 curp
->p_hdr
->eh_magic
= EXT4_EXT_MAGIC
;
1102 curp
->p_hdr
->eh_max
= cpu_to_le16(ext4_ext_space_root_idx(inode
, 0));
1103 curp
->p_hdr
->eh_entries
= cpu_to_le16(1);
1104 curp
->p_idx
= EXT_FIRST_INDEX(curp
->p_hdr
);
1106 if (path
[0].p_hdr
->eh_depth
)
1107 curp
->p_idx
->ei_block
=
1108 EXT_FIRST_INDEX(path
[0].p_hdr
)->ei_block
;
1110 curp
->p_idx
->ei_block
=
1111 EXT_FIRST_EXTENT(path
[0].p_hdr
)->ee_block
;
1112 ext4_idx_store_pblock(curp
->p_idx
, newblock
);
1114 neh
= ext_inode_hdr(inode
);
1115 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1116 le16_to_cpu(neh
->eh_entries
), le16_to_cpu(neh
->eh_max
),
1117 le32_to_cpu(EXT_FIRST_INDEX(neh
)->ei_block
),
1118 ext4_idx_pblock(EXT_FIRST_INDEX(neh
)));
1120 neh
->eh_depth
= cpu_to_le16(path
->p_depth
+ 1);
1121 err
= ext4_ext_dirty(handle
, inode
, curp
);
1129 * ext4_ext_create_new_leaf:
1130 * finds empty index and adds new leaf.
1131 * if no free index is found, then it requests in-depth growing.
1133 static int ext4_ext_create_new_leaf(handle_t
*handle
, struct inode
*inode
,
1135 struct ext4_ext_path
*path
,
1136 struct ext4_extent
*newext
)
1138 struct ext4_ext_path
*curp
;
1139 int depth
, i
, err
= 0;
1142 i
= depth
= ext_depth(inode
);
1144 /* walk up to the tree and look for free index entry */
1145 curp
= path
+ depth
;
1146 while (i
> 0 && !EXT_HAS_FREE_INDEX(curp
)) {
1151 /* we use already allocated block for index block,
1152 * so subsequent data blocks should be contiguous */
1153 if (EXT_HAS_FREE_INDEX(curp
)) {
1154 /* if we found index with free entry, then use that
1155 * entry: create all needed subtree and add new leaf */
1156 err
= ext4_ext_split(handle
, inode
, flags
, path
, newext
, i
);
1161 ext4_ext_drop_refs(path
);
1162 path
= ext4_ext_find_extent(inode
,
1163 (ext4_lblk_t
)le32_to_cpu(newext
->ee_block
),
1166 err
= PTR_ERR(path
);
1168 /* tree is full, time to grow in depth */
1169 err
= ext4_ext_grow_indepth(handle
, inode
, flags
,
1175 ext4_ext_drop_refs(path
);
1176 path
= ext4_ext_find_extent(inode
,
1177 (ext4_lblk_t
)le32_to_cpu(newext
->ee_block
),
1180 err
= PTR_ERR(path
);
1185 * only first (depth 0 -> 1) produces free space;
1186 * in all other cases we have to split the grown tree
1188 depth
= ext_depth(inode
);
1189 if (path
[depth
].p_hdr
->eh_entries
== path
[depth
].p_hdr
->eh_max
) {
1190 /* now we need to split */
1200 * search the closest allocated block to the left for *logical
1201 * and returns it at @logical + it's physical address at @phys
1202 * if *logical is the smallest allocated block, the function
1203 * returns 0 at @phys
1204 * return value contains 0 (success) or error code
1206 static int ext4_ext_search_left(struct inode
*inode
,
1207 struct ext4_ext_path
*path
,
1208 ext4_lblk_t
*logical
, ext4_fsblk_t
*phys
)
1210 struct ext4_extent_idx
*ix
;
1211 struct ext4_extent
*ex
;
1214 if (unlikely(path
== NULL
)) {
1215 EXT4_ERROR_INODE(inode
, "path == NULL *logical %d!", *logical
);
1218 depth
= path
->p_depth
;
1221 if (depth
== 0 && path
->p_ext
== NULL
)
1224 /* usually extent in the path covers blocks smaller
1225 * then *logical, but it can be that extent is the
1226 * first one in the file */
1228 ex
= path
[depth
].p_ext
;
1229 ee_len
= ext4_ext_get_actual_len(ex
);
1230 if (*logical
< le32_to_cpu(ex
->ee_block
)) {
1231 if (unlikely(EXT_FIRST_EXTENT(path
[depth
].p_hdr
) != ex
)) {
1232 EXT4_ERROR_INODE(inode
,
1233 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1234 *logical
, le32_to_cpu(ex
->ee_block
));
1237 while (--depth
>= 0) {
1238 ix
= path
[depth
].p_idx
;
1239 if (unlikely(ix
!= EXT_FIRST_INDEX(path
[depth
].p_hdr
))) {
1240 EXT4_ERROR_INODE(inode
,
1241 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1242 ix
!= NULL
? ix
->ei_block
: 0,
1243 EXT_FIRST_INDEX(path
[depth
].p_hdr
) != NULL
?
1244 EXT_FIRST_INDEX(path
[depth
].p_hdr
)->ei_block
: 0,
1252 if (unlikely(*logical
< (le32_to_cpu(ex
->ee_block
) + ee_len
))) {
1253 EXT4_ERROR_INODE(inode
,
1254 "logical %d < ee_block %d + ee_len %d!",
1255 *logical
, le32_to_cpu(ex
->ee_block
), ee_len
);
1259 *logical
= le32_to_cpu(ex
->ee_block
) + ee_len
- 1;
1260 *phys
= ext4_ext_pblock(ex
) + ee_len
- 1;
1265 * search the closest allocated block to the right 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_right(struct inode
*inode
,
1272 struct ext4_ext_path
*path
,
1273 ext4_lblk_t
*logical
, ext4_fsblk_t
*phys
,
1274 struct ext4_extent
**ret_ex
)
1276 struct buffer_head
*bh
= NULL
;
1277 struct ext4_extent_header
*eh
;
1278 struct ext4_extent_idx
*ix
;
1279 struct ext4_extent
*ex
;
1281 int depth
; /* Note, NOT eh_depth; depth from top of tree */
1284 if (unlikely(path
== NULL
)) {
1285 EXT4_ERROR_INODE(inode
, "path == NULL *logical %d!", *logical
);
1288 depth
= path
->p_depth
;
1291 if (depth
== 0 && path
->p_ext
== NULL
)
1294 /* usually extent in the path covers blocks smaller
1295 * then *logical, but it can be that extent is the
1296 * first one in the file */
1298 ex
= path
[depth
].p_ext
;
1299 ee_len
= ext4_ext_get_actual_len(ex
);
1300 if (*logical
< le32_to_cpu(ex
->ee_block
)) {
1301 if (unlikely(EXT_FIRST_EXTENT(path
[depth
].p_hdr
) != ex
)) {
1302 EXT4_ERROR_INODE(inode
,
1303 "first_extent(path[%d].p_hdr) != ex",
1307 while (--depth
>= 0) {
1308 ix
= path
[depth
].p_idx
;
1309 if (unlikely(ix
!= EXT_FIRST_INDEX(path
[depth
].p_hdr
))) {
1310 EXT4_ERROR_INODE(inode
,
1311 "ix != EXT_FIRST_INDEX *logical %d!",
1319 if (unlikely(*logical
< (le32_to_cpu(ex
->ee_block
) + ee_len
))) {
1320 EXT4_ERROR_INODE(inode
,
1321 "logical %d < ee_block %d + ee_len %d!",
1322 *logical
, le32_to_cpu(ex
->ee_block
), ee_len
);
1326 if (ex
!= EXT_LAST_EXTENT(path
[depth
].p_hdr
)) {
1327 /* next allocated block in this leaf */
1332 /* go up and search for index to the right */
1333 while (--depth
>= 0) {
1334 ix
= path
[depth
].p_idx
;
1335 if (ix
!= EXT_LAST_INDEX(path
[depth
].p_hdr
))
1339 /* we've gone up to the root and found no index to the right */
1343 /* we've found index to the right, let's
1344 * follow it and find the closest allocated
1345 * block to the right */
1347 block
= ext4_idx_pblock(ix
);
1348 while (++depth
< path
->p_depth
) {
1349 bh
= sb_bread(inode
->i_sb
, block
);
1352 eh
= ext_block_hdr(bh
);
1353 /* subtract from p_depth to get proper eh_depth */
1354 if (ext4_ext_check(inode
, eh
, path
->p_depth
- depth
)) {
1358 ix
= EXT_FIRST_INDEX(eh
);
1359 block
= ext4_idx_pblock(ix
);
1363 bh
= sb_bread(inode
->i_sb
, block
);
1366 eh
= ext_block_hdr(bh
);
1367 if (ext4_ext_check(inode
, eh
, path
->p_depth
- depth
)) {
1371 ex
= EXT_FIRST_EXTENT(eh
);
1373 *logical
= le32_to_cpu(ex
->ee_block
);
1374 *phys
= ext4_ext_pblock(ex
);
1382 * ext4_ext_next_allocated_block:
1383 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1384 * NOTE: it considers block number from index entry as
1385 * allocated block. Thus, index entries have to be consistent
1389 ext4_ext_next_allocated_block(struct ext4_ext_path
*path
)
1393 BUG_ON(path
== NULL
);
1394 depth
= path
->p_depth
;
1396 if (depth
== 0 && path
->p_ext
== NULL
)
1397 return EXT_MAX_BLOCKS
;
1399 while (depth
>= 0) {
1400 if (depth
== path
->p_depth
) {
1402 if (path
[depth
].p_ext
!=
1403 EXT_LAST_EXTENT(path
[depth
].p_hdr
))
1404 return le32_to_cpu(path
[depth
].p_ext
[1].ee_block
);
1407 if (path
[depth
].p_idx
!=
1408 EXT_LAST_INDEX(path
[depth
].p_hdr
))
1409 return le32_to_cpu(path
[depth
].p_idx
[1].ei_block
);
1414 return EXT_MAX_BLOCKS
;
1418 * ext4_ext_next_leaf_block:
1419 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1421 static ext4_lblk_t
ext4_ext_next_leaf_block(struct ext4_ext_path
*path
)
1425 BUG_ON(path
== NULL
);
1426 depth
= path
->p_depth
;
1428 /* zero-tree has no leaf blocks at all */
1430 return EXT_MAX_BLOCKS
;
1432 /* go to index block */
1435 while (depth
>= 0) {
1436 if (path
[depth
].p_idx
!=
1437 EXT_LAST_INDEX(path
[depth
].p_hdr
))
1438 return (ext4_lblk_t
)
1439 le32_to_cpu(path
[depth
].p_idx
[1].ei_block
);
1443 return EXT_MAX_BLOCKS
;
1447 * ext4_ext_correct_indexes:
1448 * if leaf gets modified and modified extent is first in the leaf,
1449 * then we have to correct all indexes above.
1450 * TODO: do we need to correct tree in all cases?
1452 static int ext4_ext_correct_indexes(handle_t
*handle
, struct inode
*inode
,
1453 struct ext4_ext_path
*path
)
1455 struct ext4_extent_header
*eh
;
1456 int depth
= ext_depth(inode
);
1457 struct ext4_extent
*ex
;
1461 eh
= path
[depth
].p_hdr
;
1462 ex
= path
[depth
].p_ext
;
1464 if (unlikely(ex
== NULL
|| eh
== NULL
)) {
1465 EXT4_ERROR_INODE(inode
,
1466 "ex %p == NULL or eh %p == NULL", ex
, eh
);
1471 /* there is no tree at all */
1475 if (ex
!= EXT_FIRST_EXTENT(eh
)) {
1476 /* we correct tree if first leaf got modified only */
1481 * TODO: we need correction if border is smaller than current one
1484 border
= path
[depth
].p_ext
->ee_block
;
1485 err
= ext4_ext_get_access(handle
, inode
, path
+ k
);
1488 path
[k
].p_idx
->ei_block
= border
;
1489 err
= ext4_ext_dirty(handle
, inode
, path
+ k
);
1494 /* change all left-side indexes */
1495 if (path
[k
+1].p_idx
!= EXT_FIRST_INDEX(path
[k
+1].p_hdr
))
1497 err
= ext4_ext_get_access(handle
, inode
, path
+ k
);
1500 path
[k
].p_idx
->ei_block
= border
;
1501 err
= ext4_ext_dirty(handle
, inode
, path
+ k
);
1510 ext4_can_extents_be_merged(struct inode
*inode
, struct ext4_extent
*ex1
,
1511 struct ext4_extent
*ex2
)
1513 unsigned short ext1_ee_len
, ext2_ee_len
, max_len
;
1516 * Make sure that either both extents are uninitialized, or
1519 if (ext4_ext_is_uninitialized(ex1
) ^ ext4_ext_is_uninitialized(ex2
))
1522 if (ext4_ext_is_uninitialized(ex1
))
1523 max_len
= EXT_UNINIT_MAX_LEN
;
1525 max_len
= EXT_INIT_MAX_LEN
;
1527 ext1_ee_len
= ext4_ext_get_actual_len(ex1
);
1528 ext2_ee_len
= ext4_ext_get_actual_len(ex2
);
1530 if (le32_to_cpu(ex1
->ee_block
) + ext1_ee_len
!=
1531 le32_to_cpu(ex2
->ee_block
))
1535 * To allow future support for preallocated extents to be added
1536 * as an RO_COMPAT feature, refuse to merge to extents if
1537 * this can result in the top bit of ee_len being set.
1539 if (ext1_ee_len
+ ext2_ee_len
> max_len
)
1541 #ifdef AGGRESSIVE_TEST
1542 if (ext1_ee_len
>= 4)
1546 if (ext4_ext_pblock(ex1
) + ext1_ee_len
== ext4_ext_pblock(ex2
))
1552 * This function tries to merge the "ex" extent to the next extent in the tree.
1553 * It always tries to merge towards right. If you want to merge towards
1554 * left, pass "ex - 1" as argument instead of "ex".
1555 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1556 * 1 if they got merged.
1558 static int ext4_ext_try_to_merge_right(struct inode
*inode
,
1559 struct ext4_ext_path
*path
,
1560 struct ext4_extent
*ex
)
1562 struct ext4_extent_header
*eh
;
1563 unsigned int depth
, len
;
1565 int uninitialized
= 0;
1567 depth
= ext_depth(inode
);
1568 BUG_ON(path
[depth
].p_hdr
== NULL
);
1569 eh
= path
[depth
].p_hdr
;
1571 while (ex
< EXT_LAST_EXTENT(eh
)) {
1572 if (!ext4_can_extents_be_merged(inode
, ex
, ex
+ 1))
1574 /* merge with next extent! */
1575 if (ext4_ext_is_uninitialized(ex
))
1577 ex
->ee_len
= cpu_to_le16(ext4_ext_get_actual_len(ex
)
1578 + ext4_ext_get_actual_len(ex
+ 1));
1580 ext4_ext_mark_uninitialized(ex
);
1582 if (ex
+ 1 < EXT_LAST_EXTENT(eh
)) {
1583 len
= (EXT_LAST_EXTENT(eh
) - ex
- 1)
1584 * sizeof(struct ext4_extent
);
1585 memmove(ex
+ 1, ex
+ 2, len
);
1587 le16_add_cpu(&eh
->eh_entries
, -1);
1589 WARN_ON(eh
->eh_entries
== 0);
1590 if (!eh
->eh_entries
)
1591 EXT4_ERROR_INODE(inode
, "eh->eh_entries = 0!");
1598 * This function tries to merge the @ex extent to neighbours in the tree.
1599 * return 1 if merge left else 0.
1601 static int ext4_ext_try_to_merge(struct inode
*inode
,
1602 struct ext4_ext_path
*path
,
1603 struct ext4_extent
*ex
) {
1604 struct ext4_extent_header
*eh
;
1609 depth
= ext_depth(inode
);
1610 BUG_ON(path
[depth
].p_hdr
== NULL
);
1611 eh
= path
[depth
].p_hdr
;
1613 if (ex
> EXT_FIRST_EXTENT(eh
))
1614 merge_done
= ext4_ext_try_to_merge_right(inode
, path
, ex
- 1);
1617 ret
= ext4_ext_try_to_merge_right(inode
, path
, ex
);
1623 * check if a portion of the "newext" extent overlaps with an
1626 * If there is an overlap discovered, it updates the length of the newext
1627 * such that there will be no overlap, and then returns 1.
1628 * If there is no overlap found, it returns 0.
1630 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info
*sbi
,
1631 struct inode
*inode
,
1632 struct ext4_extent
*newext
,
1633 struct ext4_ext_path
*path
)
1636 unsigned int depth
, len1
;
1637 unsigned int ret
= 0;
1639 b1
= le32_to_cpu(newext
->ee_block
);
1640 len1
= ext4_ext_get_actual_len(newext
);
1641 depth
= ext_depth(inode
);
1642 if (!path
[depth
].p_ext
)
1644 b2
= le32_to_cpu(path
[depth
].p_ext
->ee_block
);
1645 b2
&= ~(sbi
->s_cluster_ratio
- 1);
1648 * get the next allocated block if the extent in the path
1649 * is before the requested block(s)
1652 b2
= ext4_ext_next_allocated_block(path
);
1653 if (b2
== EXT_MAX_BLOCKS
)
1655 b2
&= ~(sbi
->s_cluster_ratio
- 1);
1658 /* check for wrap through zero on extent logical start block*/
1659 if (b1
+ len1
< b1
) {
1660 len1
= EXT_MAX_BLOCKS
- b1
;
1661 newext
->ee_len
= cpu_to_le16(len1
);
1665 /* check for overlap */
1666 if (b1
+ len1
> b2
) {
1667 newext
->ee_len
= cpu_to_le16(b2
- b1
);
1675 * ext4_ext_insert_extent:
1676 * tries to merge requsted extent into the existing extent or
1677 * inserts requested extent as new one into the tree,
1678 * creating new leaf in the no-space case.
1680 int ext4_ext_insert_extent(handle_t
*handle
, struct inode
*inode
,
1681 struct ext4_ext_path
*path
,
1682 struct ext4_extent
*newext
, int flag
)
1684 struct ext4_extent_header
*eh
;
1685 struct ext4_extent
*ex
, *fex
;
1686 struct ext4_extent
*nearex
; /* nearest extent */
1687 struct ext4_ext_path
*npath
= NULL
;
1688 int depth
, len
, err
;
1690 unsigned uninitialized
= 0;
1693 if (unlikely(ext4_ext_get_actual_len(newext
) == 0)) {
1694 EXT4_ERROR_INODE(inode
, "ext4_ext_get_actual_len(newext) == 0");
1697 depth
= ext_depth(inode
);
1698 ex
= path
[depth
].p_ext
;
1699 if (unlikely(path
[depth
].p_hdr
== NULL
)) {
1700 EXT4_ERROR_INODE(inode
, "path[%d].p_hdr == NULL", depth
);
1704 /* try to insert block into found extent and return */
1705 if (ex
&& !(flag
& EXT4_GET_BLOCKS_PRE_IO
)
1706 && ext4_can_extents_be_merged(inode
, ex
, newext
)) {
1707 ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n",
1708 ext4_ext_is_uninitialized(newext
),
1709 ext4_ext_get_actual_len(newext
),
1710 le32_to_cpu(ex
->ee_block
),
1711 ext4_ext_is_uninitialized(ex
),
1712 ext4_ext_get_actual_len(ex
),
1713 ext4_ext_pblock(ex
));
1714 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
1719 * ext4_can_extents_be_merged should have checked that either
1720 * both extents are uninitialized, or both aren't. Thus we
1721 * need to check only one of them here.
1723 if (ext4_ext_is_uninitialized(ex
))
1725 ex
->ee_len
= cpu_to_le16(ext4_ext_get_actual_len(ex
)
1726 + ext4_ext_get_actual_len(newext
));
1728 ext4_ext_mark_uninitialized(ex
);
1729 eh
= path
[depth
].p_hdr
;
1734 depth
= ext_depth(inode
);
1735 eh
= path
[depth
].p_hdr
;
1736 if (le16_to_cpu(eh
->eh_entries
) < le16_to_cpu(eh
->eh_max
))
1739 /* probably next leaf has space for us? */
1740 fex
= EXT_LAST_EXTENT(eh
);
1741 next
= EXT_MAX_BLOCKS
;
1742 if (le32_to_cpu(newext
->ee_block
) > le32_to_cpu(fex
->ee_block
))
1743 next
= ext4_ext_next_leaf_block(path
);
1744 if (next
!= EXT_MAX_BLOCKS
) {
1745 ext_debug("next leaf block - %d\n", next
);
1746 BUG_ON(npath
!= NULL
);
1747 npath
= ext4_ext_find_extent(inode
, next
, NULL
);
1749 return PTR_ERR(npath
);
1750 BUG_ON(npath
->p_depth
!= path
->p_depth
);
1751 eh
= npath
[depth
].p_hdr
;
1752 if (le16_to_cpu(eh
->eh_entries
) < le16_to_cpu(eh
->eh_max
)) {
1753 ext_debug("next leaf isn't full(%d)\n",
1754 le16_to_cpu(eh
->eh_entries
));
1758 ext_debug("next leaf has no free space(%d,%d)\n",
1759 le16_to_cpu(eh
->eh_entries
), le16_to_cpu(eh
->eh_max
));
1763 * There is no free space in the found leaf.
1764 * We're gonna add a new leaf in the tree.
1766 if (flag
& EXT4_GET_BLOCKS_PUNCH_OUT_EXT
)
1767 flags
= EXT4_MB_USE_ROOT_BLOCKS
;
1768 err
= ext4_ext_create_new_leaf(handle
, inode
, flags
, path
, newext
);
1771 depth
= ext_depth(inode
);
1772 eh
= path
[depth
].p_hdr
;
1775 nearex
= path
[depth
].p_ext
;
1777 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
1782 /* there is no extent in this leaf, create first one */
1783 ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n",
1784 le32_to_cpu(newext
->ee_block
),
1785 ext4_ext_pblock(newext
),
1786 ext4_ext_is_uninitialized(newext
),
1787 ext4_ext_get_actual_len(newext
));
1788 path
[depth
].p_ext
= EXT_FIRST_EXTENT(eh
);
1789 } else if (le32_to_cpu(newext
->ee_block
)
1790 > le32_to_cpu(nearex
->ee_block
)) {
1791 /* BUG_ON(newext->ee_block == nearex->ee_block); */
1792 if (nearex
!= EXT_LAST_EXTENT(eh
)) {
1793 len
= EXT_MAX_EXTENT(eh
) - nearex
;
1794 len
= (len
- 1) * sizeof(struct ext4_extent
);
1795 len
= len
< 0 ? 0 : len
;
1796 ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, "
1797 "move %d from 0x%p to 0x%p\n",
1798 le32_to_cpu(newext
->ee_block
),
1799 ext4_ext_pblock(newext
),
1800 ext4_ext_is_uninitialized(newext
),
1801 ext4_ext_get_actual_len(newext
),
1802 nearex
, len
, nearex
+ 1, nearex
+ 2);
1803 memmove(nearex
+ 2, nearex
+ 1, len
);
1805 path
[depth
].p_ext
= nearex
+ 1;
1807 BUG_ON(newext
->ee_block
== nearex
->ee_block
);
1808 len
= (EXT_MAX_EXTENT(eh
) - nearex
) * sizeof(struct ext4_extent
);
1809 len
= len
< 0 ? 0 : len
;
1810 ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, "
1811 "move %d from 0x%p to 0x%p\n",
1812 le32_to_cpu(newext
->ee_block
),
1813 ext4_ext_pblock(newext
),
1814 ext4_ext_is_uninitialized(newext
),
1815 ext4_ext_get_actual_len(newext
),
1816 nearex
, len
, nearex
, nearex
+ 1);
1817 memmove(nearex
+ 1, nearex
, len
);
1818 path
[depth
].p_ext
= nearex
;
1821 le16_add_cpu(&eh
->eh_entries
, 1);
1822 nearex
= path
[depth
].p_ext
;
1823 nearex
->ee_block
= newext
->ee_block
;
1824 ext4_ext_store_pblock(nearex
, ext4_ext_pblock(newext
));
1825 nearex
->ee_len
= newext
->ee_len
;
1828 /* try to merge extents to the right */
1829 if (!(flag
& EXT4_GET_BLOCKS_PRE_IO
))
1830 ext4_ext_try_to_merge(inode
, path
, nearex
);
1832 /* try to merge extents to the left */
1834 /* time to correct all indexes above */
1835 err
= ext4_ext_correct_indexes(handle
, inode
, path
);
1839 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
1843 ext4_ext_drop_refs(npath
);
1846 ext4_ext_invalidate_cache(inode
);
1850 static int ext4_ext_walk_space(struct inode
*inode
, ext4_lblk_t block
,
1851 ext4_lblk_t num
, ext_prepare_callback func
,
1854 struct ext4_ext_path
*path
= NULL
;
1855 struct ext4_ext_cache cbex
;
1856 struct ext4_extent
*ex
;
1857 ext4_lblk_t next
, start
= 0, end
= 0;
1858 ext4_lblk_t last
= block
+ num
;
1859 int depth
, exists
, err
= 0;
1861 BUG_ON(func
== NULL
);
1862 BUG_ON(inode
== NULL
);
1864 while (block
< last
&& block
!= EXT_MAX_BLOCKS
) {
1866 /* find extent for this block */
1867 down_read(&EXT4_I(inode
)->i_data_sem
);
1868 path
= ext4_ext_find_extent(inode
, block
, path
);
1869 up_read(&EXT4_I(inode
)->i_data_sem
);
1871 err
= PTR_ERR(path
);
1876 depth
= ext_depth(inode
);
1877 if (unlikely(path
[depth
].p_hdr
== NULL
)) {
1878 EXT4_ERROR_INODE(inode
, "path[%d].p_hdr == NULL", depth
);
1882 ex
= path
[depth
].p_ext
;
1883 next
= ext4_ext_next_allocated_block(path
);
1887 /* there is no extent yet, so try to allocate
1888 * all requested space */
1891 } else if (le32_to_cpu(ex
->ee_block
) > block
) {
1892 /* need to allocate space before found extent */
1894 end
= le32_to_cpu(ex
->ee_block
);
1895 if (block
+ num
< end
)
1897 } else if (block
>= le32_to_cpu(ex
->ee_block
)
1898 + ext4_ext_get_actual_len(ex
)) {
1899 /* need to allocate space after found extent */
1904 } else if (block
>= le32_to_cpu(ex
->ee_block
)) {
1906 * some part of requested space is covered
1910 end
= le32_to_cpu(ex
->ee_block
)
1911 + ext4_ext_get_actual_len(ex
);
1912 if (block
+ num
< end
)
1918 BUG_ON(end
<= start
);
1921 cbex
.ec_block
= start
;
1922 cbex
.ec_len
= end
- start
;
1925 cbex
.ec_block
= le32_to_cpu(ex
->ee_block
);
1926 cbex
.ec_len
= ext4_ext_get_actual_len(ex
);
1927 cbex
.ec_start
= ext4_ext_pblock(ex
);
1930 if (unlikely(cbex
.ec_len
== 0)) {
1931 EXT4_ERROR_INODE(inode
, "cbex.ec_len == 0");
1935 err
= func(inode
, next
, &cbex
, ex
, cbdata
);
1936 ext4_ext_drop_refs(path
);
1941 if (err
== EXT_REPEAT
)
1943 else if (err
== EXT_BREAK
) {
1948 if (ext_depth(inode
) != depth
) {
1949 /* depth was changed. we have to realloc path */
1954 block
= cbex
.ec_block
+ cbex
.ec_len
;
1958 ext4_ext_drop_refs(path
);
1966 ext4_ext_put_in_cache(struct inode
*inode
, ext4_lblk_t block
,
1967 __u32 len
, ext4_fsblk_t start
)
1969 struct ext4_ext_cache
*cex
;
1971 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
1972 cex
= &EXT4_I(inode
)->i_cached_extent
;
1973 cex
->ec_block
= block
;
1975 cex
->ec_start
= start
;
1976 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
1980 * ext4_ext_put_gap_in_cache:
1981 * calculate boundaries of the gap that the requested block fits into
1982 * and cache this gap
1985 ext4_ext_put_gap_in_cache(struct inode
*inode
, struct ext4_ext_path
*path
,
1988 int depth
= ext_depth(inode
);
1991 struct ext4_extent
*ex
;
1993 ex
= path
[depth
].p_ext
;
1995 /* there is no extent yet, so gap is [0;-] */
1997 len
= EXT_MAX_BLOCKS
;
1998 ext_debug("cache gap(whole file):");
1999 } else if (block
< le32_to_cpu(ex
->ee_block
)) {
2001 len
= le32_to_cpu(ex
->ee_block
) - block
;
2002 ext_debug("cache gap(before): %u [%u:%u]",
2004 le32_to_cpu(ex
->ee_block
),
2005 ext4_ext_get_actual_len(ex
));
2006 } else if (block
>= le32_to_cpu(ex
->ee_block
)
2007 + ext4_ext_get_actual_len(ex
)) {
2009 lblock
= le32_to_cpu(ex
->ee_block
)
2010 + ext4_ext_get_actual_len(ex
);
2012 next
= ext4_ext_next_allocated_block(path
);
2013 ext_debug("cache gap(after): [%u:%u] %u",
2014 le32_to_cpu(ex
->ee_block
),
2015 ext4_ext_get_actual_len(ex
),
2017 BUG_ON(next
== lblock
);
2018 len
= next
- lblock
;
2024 ext_debug(" -> %u:%lu\n", lblock
, len
);
2025 ext4_ext_put_in_cache(inode
, lblock
, len
, 0);
2029 * ext4_ext_check_cache()
2030 * Checks to see if the given block is in the cache.
2031 * If it is, the cached extent is stored in the given
2032 * cache extent pointer. If the cached extent is a hole,
2033 * this routine should be used instead of
2034 * ext4_ext_in_cache if the calling function needs to
2035 * know the size of the hole.
2037 * @inode: The files inode
2038 * @block: The block to look for in the cache
2039 * @ex: Pointer where the cached extent will be stored
2040 * if it contains block
2042 * Return 0 if cache is invalid; 1 if the cache is valid
2044 static int ext4_ext_check_cache(struct inode
*inode
, ext4_lblk_t block
,
2045 struct ext4_ext_cache
*ex
){
2046 struct ext4_ext_cache
*cex
;
2047 struct ext4_sb_info
*sbi
;
2051 * We borrow i_block_reservation_lock to protect i_cached_extent
2053 spin_lock(&EXT4_I(inode
)->i_block_reservation_lock
);
2054 cex
= &EXT4_I(inode
)->i_cached_extent
;
2055 sbi
= EXT4_SB(inode
->i_sb
);
2057 /* has cache valid data? */
2058 if (cex
->ec_len
== 0)
2061 if (in_range(block
, cex
->ec_block
, cex
->ec_len
)) {
2062 memcpy(ex
, cex
, sizeof(struct ext4_ext_cache
));
2063 ext_debug("%u cached by %u:%u:%llu\n",
2065 cex
->ec_block
, cex
->ec_len
, cex
->ec_start
);
2070 sbi
->extent_cache_misses
++;
2072 sbi
->extent_cache_hits
++;
2073 spin_unlock(&EXT4_I(inode
)->i_block_reservation_lock
);
2078 * ext4_ext_in_cache()
2079 * Checks to see if the given block is in the cache.
2080 * If it is, the cached extent is stored in the given
2083 * @inode: The files inode
2084 * @block: The block to look for in the cache
2085 * @ex: Pointer where the cached extent will be stored
2086 * if it contains block
2088 * Return 0 if cache is invalid; 1 if the cache is valid
2091 ext4_ext_in_cache(struct inode
*inode
, ext4_lblk_t block
,
2092 struct ext4_extent
*ex
)
2094 struct ext4_ext_cache cex
;
2097 if (ext4_ext_check_cache(inode
, block
, &cex
)) {
2098 ex
->ee_block
= cpu_to_le32(cex
.ec_block
);
2099 ext4_ext_store_pblock(ex
, cex
.ec_start
);
2100 ex
->ee_len
= cpu_to_le16(cex
.ec_len
);
2110 * removes index from the index block.
2112 static int ext4_ext_rm_idx(handle_t
*handle
, struct inode
*inode
,
2113 struct ext4_ext_path
*path
)
2118 /* free index block */
2120 leaf
= ext4_idx_pblock(path
->p_idx
);
2121 if (unlikely(path
->p_hdr
->eh_entries
== 0)) {
2122 EXT4_ERROR_INODE(inode
, "path->p_hdr->eh_entries == 0");
2125 err
= ext4_ext_get_access(handle
, inode
, path
);
2129 if (path
->p_idx
!= EXT_LAST_INDEX(path
->p_hdr
)) {
2130 int len
= EXT_LAST_INDEX(path
->p_hdr
) - path
->p_idx
;
2131 len
*= sizeof(struct ext4_extent_idx
);
2132 memmove(path
->p_idx
, path
->p_idx
+ 1, len
);
2135 le16_add_cpu(&path
->p_hdr
->eh_entries
, -1);
2136 err
= ext4_ext_dirty(handle
, inode
, path
);
2139 ext_debug("index is empty, remove it, free block %llu\n", leaf
);
2140 ext4_free_blocks(handle
, inode
, NULL
, leaf
, 1,
2141 EXT4_FREE_BLOCKS_METADATA
| EXT4_FREE_BLOCKS_FORGET
);
2146 * ext4_ext_calc_credits_for_single_extent:
2147 * This routine returns max. credits that needed to insert an extent
2148 * to the extent tree.
2149 * When pass the actual path, the caller should calculate credits
2152 int ext4_ext_calc_credits_for_single_extent(struct inode
*inode
, int nrblocks
,
2153 struct ext4_ext_path
*path
)
2156 int depth
= ext_depth(inode
);
2159 /* probably there is space in leaf? */
2160 if (le16_to_cpu(path
[depth
].p_hdr
->eh_entries
)
2161 < le16_to_cpu(path
[depth
].p_hdr
->eh_max
)) {
2164 * There are some space in the leaf tree, no
2165 * need to account for leaf block credit
2167 * bitmaps and block group descriptor blocks
2168 * and other metadat blocks still need to be
2171 /* 1 bitmap, 1 block group descriptor */
2172 ret
= 2 + EXT4_META_TRANS_BLOCKS(inode
->i_sb
);
2177 return ext4_chunk_trans_blocks(inode
, nrblocks
);
2181 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2183 * if nrblocks are fit in a single extent (chunk flag is 1), then
2184 * in the worse case, each tree level index/leaf need to be changed
2185 * if the tree split due to insert a new extent, then the old tree
2186 * index/leaf need to be updated too
2188 * If the nrblocks are discontiguous, they could cause
2189 * the whole tree split more than once, but this is really rare.
2191 int ext4_ext_index_trans_blocks(struct inode
*inode
, int nrblocks
, int chunk
)
2194 int depth
= ext_depth(inode
);
2204 static int ext4_remove_blocks(handle_t
*handle
, struct inode
*inode
,
2205 struct ext4_extent
*ex
,
2206 ext4_fsblk_t
*partial_cluster
,
2207 ext4_lblk_t from
, ext4_lblk_t to
)
2209 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2210 unsigned short ee_len
= ext4_ext_get_actual_len(ex
);
2212 int flags
= EXT4_FREE_BLOCKS_FORGET
;
2214 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
2215 flags
|= EXT4_FREE_BLOCKS_METADATA
;
2217 * For bigalloc file systems, we never free a partial cluster
2218 * at the beginning of the extent. Instead, we make a note
2219 * that we tried freeing the cluster, and check to see if we
2220 * need to free it on a subsequent call to ext4_remove_blocks,
2221 * or at the end of the ext4_truncate() operation.
2223 flags
|= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER
;
2226 * If we have a partial cluster, and it's different from the
2227 * cluster of the last block, we need to explicitly free the
2228 * partial cluster here.
2230 pblk
= ext4_ext_pblock(ex
) + ee_len
- 1;
2231 if (*partial_cluster
&& (EXT4_B2C(sbi
, pblk
) != *partial_cluster
)) {
2232 ext4_free_blocks(handle
, inode
, NULL
,
2233 EXT4_C2B(sbi
, *partial_cluster
),
2234 sbi
->s_cluster_ratio
, flags
);
2235 *partial_cluster
= 0;
2238 #ifdef EXTENTS_STATS
2240 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2241 spin_lock(&sbi
->s_ext_stats_lock
);
2242 sbi
->s_ext_blocks
+= ee_len
;
2243 sbi
->s_ext_extents
++;
2244 if (ee_len
< sbi
->s_ext_min
)
2245 sbi
->s_ext_min
= ee_len
;
2246 if (ee_len
> sbi
->s_ext_max
)
2247 sbi
->s_ext_max
= ee_len
;
2248 if (ext_depth(inode
) > sbi
->s_depth_max
)
2249 sbi
->s_depth_max
= ext_depth(inode
);
2250 spin_unlock(&sbi
->s_ext_stats_lock
);
2253 if (from
>= le32_to_cpu(ex
->ee_block
)
2254 && to
== le32_to_cpu(ex
->ee_block
) + ee_len
- 1) {
2258 num
= le32_to_cpu(ex
->ee_block
) + ee_len
- from
;
2259 pblk
= ext4_ext_pblock(ex
) + ee_len
- num
;
2260 ext_debug("free last %u blocks starting %llu\n", num
, pblk
);
2261 ext4_free_blocks(handle
, inode
, NULL
, pblk
, num
, flags
);
2263 * If the block range to be freed didn't start at the
2264 * beginning of a cluster, and we removed the entire
2265 * extent, save the partial cluster here, since we
2266 * might need to delete if we determine that the
2267 * truncate operation has removed all of the blocks in
2270 if (pblk
& (sbi
->s_cluster_ratio
- 1) &&
2272 *partial_cluster
= EXT4_B2C(sbi
, pblk
);
2274 *partial_cluster
= 0;
2275 } else if (from
== le32_to_cpu(ex
->ee_block
)
2276 && to
<= le32_to_cpu(ex
->ee_block
) + ee_len
- 1) {
2282 start
= ext4_ext_pblock(ex
);
2284 ext_debug("free first %u blocks starting %llu\n", num
, start
);
2285 ext4_free_blocks(handle
, inode
, 0, start
, num
, flags
);
2288 printk(KERN_INFO
"strange request: removal(2) "
2289 "%u-%u from %u:%u\n",
2290 from
, to
, le32_to_cpu(ex
->ee_block
), ee_len
);
2297 * ext4_ext_rm_leaf() Removes the extents associated with the
2298 * blocks appearing between "start" and "end", and splits the extents
2299 * if "start" and "end" appear in the same extent
2301 * @handle: The journal handle
2302 * @inode: The files inode
2303 * @path: The path to the leaf
2304 * @start: The first block to remove
2305 * @end: The last block to remove
2308 ext4_ext_rm_leaf(handle_t
*handle
, struct inode
*inode
,
2309 struct ext4_ext_path
*path
, ext4_fsblk_t
*partial_cluster
,
2310 ext4_lblk_t start
, ext4_lblk_t end
)
2312 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
2313 int err
= 0, correct_index
= 0;
2314 int depth
= ext_depth(inode
), credits
;
2315 struct ext4_extent_header
*eh
;
2316 ext4_lblk_t a
, b
, block
;
2318 ext4_lblk_t ex_ee_block
;
2319 unsigned short ex_ee_len
;
2320 unsigned uninitialized
= 0;
2321 struct ext4_extent
*ex
;
2322 struct ext4_map_blocks map
;
2324 /* the header must be checked already in ext4_ext_remove_space() */
2325 ext_debug("truncate since %u in leaf\n", start
);
2326 if (!path
[depth
].p_hdr
)
2327 path
[depth
].p_hdr
= ext_block_hdr(path
[depth
].p_bh
);
2328 eh
= path
[depth
].p_hdr
;
2329 if (unlikely(path
[depth
].p_hdr
== NULL
)) {
2330 EXT4_ERROR_INODE(inode
, "path[%d].p_hdr == NULL", depth
);
2333 /* find where to start removing */
2334 ex
= EXT_LAST_EXTENT(eh
);
2336 ex_ee_block
= le32_to_cpu(ex
->ee_block
);
2337 ex_ee_len
= ext4_ext_get_actual_len(ex
);
2339 while (ex
>= EXT_FIRST_EXTENT(eh
) &&
2340 ex_ee_block
+ ex_ee_len
> start
) {
2342 if (ext4_ext_is_uninitialized(ex
))
2347 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block
,
2348 uninitialized
, ex_ee_len
);
2349 path
[depth
].p_ext
= ex
;
2351 a
= ex_ee_block
> start
? ex_ee_block
: start
;
2352 b
= ex_ee_block
+ex_ee_len
- 1 < end
?
2353 ex_ee_block
+ex_ee_len
- 1 : end
;
2355 ext_debug(" border %u:%u\n", a
, b
);
2357 /* If this extent is beyond the end of the hole, skip it */
2358 if (end
<= ex_ee_block
) {
2360 ex_ee_block
= le32_to_cpu(ex
->ee_block
);
2361 ex_ee_len
= ext4_ext_get_actual_len(ex
);
2363 } else if (a
!= ex_ee_block
&&
2364 b
!= ex_ee_block
+ ex_ee_len
- 1) {
2366 * If this is a truncate, then this condition should
2367 * never happen because at least one of the end points
2368 * needs to be on the edge of the extent.
2370 if (end
== EXT_MAX_BLOCKS
- 1) {
2371 ext_debug(" bad truncate %u:%u\n",
2379 * else this is a hole punch, so the extent needs to
2380 * be split since neither edge of the hole is on the
2384 map
.m_pblk
= ext4_ext_pblock(ex
);
2385 map
.m_lblk
= ex_ee_block
;
2386 map
.m_len
= b
- ex_ee_block
;
2388 err
= ext4_split_extent(handle
,
2389 inode
, path
, &map
, 0,
2390 EXT4_GET_BLOCKS_PUNCH_OUT_EXT
|
2391 EXT4_GET_BLOCKS_PRE_IO
);
2396 ex_ee_len
= ext4_ext_get_actual_len(ex
);
2398 b
= ex_ee_block
+ex_ee_len
- 1 < end
?
2399 ex_ee_block
+ex_ee_len
- 1 : end
;
2401 /* Then remove tail of this extent */
2402 block
= ex_ee_block
;
2405 } else if (a
!= ex_ee_block
) {
2406 /* remove tail of the extent */
2407 block
= ex_ee_block
;
2409 } else if (b
!= ex_ee_block
+ ex_ee_len
- 1) {
2410 /* remove head of the extent */
2412 num
= ex_ee_block
+ ex_ee_len
- b
;
2415 * If this is a truncate, this condition
2416 * should never happen
2418 if (end
== EXT_MAX_BLOCKS
- 1) {
2419 ext_debug(" bad truncate %u:%u\n",
2425 /* remove whole extent: excellent! */
2426 block
= ex_ee_block
;
2428 if (a
!= ex_ee_block
) {
2429 ext_debug(" bad truncate %u:%u\n",
2435 if (b
!= ex_ee_block
+ ex_ee_len
- 1) {
2436 ext_debug(" bad truncate %u:%u\n",
2444 * 3 for leaf, sb, and inode plus 2 (bmap and group
2445 * descriptor) for each block group; assume two block
2446 * groups plus ex_ee_len/blocks_per_block_group for
2449 credits
= 7 + 2*(ex_ee_len
/EXT4_BLOCKS_PER_GROUP(inode
->i_sb
));
2450 if (ex
== EXT_FIRST_EXTENT(eh
)) {
2452 credits
+= (ext_depth(inode
)) + 1;
2454 credits
+= EXT4_MAXQUOTAS_TRANS_BLOCKS(inode
->i_sb
);
2456 err
= ext4_ext_truncate_extend_restart(handle
, inode
, credits
);
2460 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
2464 err
= ext4_remove_blocks(handle
, inode
, ex
, partial_cluster
,
2470 /* this extent is removed; mark slot entirely unused */
2471 ext4_ext_store_pblock(ex
, 0);
2472 } else if (block
!= ex_ee_block
) {
2474 * If this was a head removal, then we need to update
2475 * the physical block since it is now at a different
2478 ext4_ext_store_pblock(ex
, ext4_ext_pblock(ex
) + (b
-a
));
2481 ex
->ee_block
= cpu_to_le32(block
);
2482 ex
->ee_len
= cpu_to_le16(num
);
2484 * Do not mark uninitialized if all the blocks in the
2485 * extent have been removed.
2487 if (uninitialized
&& num
)
2488 ext4_ext_mark_uninitialized(ex
);
2490 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
2495 * If the extent was completely released,
2496 * we need to remove it from the leaf
2499 if (end
!= EXT_MAX_BLOCKS
- 1) {
2501 * For hole punching, we need to scoot all the
2502 * extents up when an extent is removed so that
2503 * we dont have blank extents in the middle
2505 memmove(ex
, ex
+1, (EXT_LAST_EXTENT(eh
) - ex
) *
2506 sizeof(struct ext4_extent
));
2508 /* Now get rid of the one at the end */
2509 memset(EXT_LAST_EXTENT(eh
), 0,
2510 sizeof(struct ext4_extent
));
2512 le16_add_cpu(&eh
->eh_entries
, -1);
2514 *partial_cluster
= 0;
2516 ext_debug("new extent: %u:%u:%llu\n", block
, num
,
2517 ext4_ext_pblock(ex
));
2519 ex_ee_block
= le32_to_cpu(ex
->ee_block
);
2520 ex_ee_len
= ext4_ext_get_actual_len(ex
);
2523 if (correct_index
&& eh
->eh_entries
)
2524 err
= ext4_ext_correct_indexes(handle
, inode
, path
);
2527 * If there is still a entry in the leaf node, check to see if
2528 * it references the partial cluster. This is the only place
2529 * where it could; if it doesn't, we can free the cluster.
2531 if (*partial_cluster
&& ex
>= EXT_FIRST_EXTENT(eh
) &&
2532 (EXT4_B2C(sbi
, ext4_ext_pblock(ex
) + ex_ee_len
- 1) !=
2533 *partial_cluster
)) {
2534 int flags
= EXT4_FREE_BLOCKS_FORGET
;
2536 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
2537 flags
|= EXT4_FREE_BLOCKS_METADATA
;
2539 ext4_free_blocks(handle
, inode
, NULL
,
2540 EXT4_C2B(sbi
, *partial_cluster
),
2541 sbi
->s_cluster_ratio
, flags
);
2542 *partial_cluster
= 0;
2545 /* if this leaf is free, then we should
2546 * remove it from index block above */
2547 if (err
== 0 && eh
->eh_entries
== 0 && path
[depth
].p_bh
!= NULL
)
2548 err
= ext4_ext_rm_idx(handle
, inode
, path
+ depth
);
2555 * ext4_ext_more_to_rm:
2556 * returns 1 if current index has to be freed (even partial)
2559 ext4_ext_more_to_rm(struct ext4_ext_path
*path
)
2561 BUG_ON(path
->p_idx
== NULL
);
2563 if (path
->p_idx
< EXT_FIRST_INDEX(path
->p_hdr
))
2567 * if truncate on deeper level happened, it wasn't partial,
2568 * so we have to consider current index for truncation
2570 if (le16_to_cpu(path
->p_hdr
->eh_entries
) == path
->p_block
)
2575 static int ext4_ext_remove_space(struct inode
*inode
, ext4_lblk_t start
)
2577 struct super_block
*sb
= inode
->i_sb
;
2578 int depth
= ext_depth(inode
);
2579 struct ext4_ext_path
*path
;
2580 ext4_fsblk_t partial_cluster
= 0;
2584 ext_debug("truncate since %u\n", start
);
2586 /* probably first extent we're gonna free will be last in block */
2587 handle
= ext4_journal_start(inode
, depth
+ 1);
2589 return PTR_ERR(handle
);
2592 ext4_ext_invalidate_cache(inode
);
2595 * We start scanning from right side, freeing all the blocks
2596 * after i_size and walking into the tree depth-wise.
2598 depth
= ext_depth(inode
);
2599 path
= kzalloc(sizeof(struct ext4_ext_path
) * (depth
+ 1), GFP_NOFS
);
2601 ext4_journal_stop(handle
);
2604 path
[0].p_depth
= depth
;
2605 path
[0].p_hdr
= ext_inode_hdr(inode
);
2606 if (ext4_ext_check(inode
, path
[0].p_hdr
, depth
)) {
2612 while (i
>= 0 && err
== 0) {
2614 /* this is leaf block */
2615 err
= ext4_ext_rm_leaf(handle
, inode
, path
,
2616 &partial_cluster
, start
,
2617 EXT_MAX_BLOCKS
- 1);
2618 /* root level has p_bh == NULL, brelse() eats this */
2619 brelse(path
[i
].p_bh
);
2620 path
[i
].p_bh
= NULL
;
2625 /* this is index block */
2626 if (!path
[i
].p_hdr
) {
2627 ext_debug("initialize header\n");
2628 path
[i
].p_hdr
= ext_block_hdr(path
[i
].p_bh
);
2631 if (!path
[i
].p_idx
) {
2632 /* this level hasn't been touched yet */
2633 path
[i
].p_idx
= EXT_LAST_INDEX(path
[i
].p_hdr
);
2634 path
[i
].p_block
= le16_to_cpu(path
[i
].p_hdr
->eh_entries
)+1;
2635 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2637 le16_to_cpu(path
[i
].p_hdr
->eh_entries
));
2639 /* we were already here, see at next index */
2643 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2644 i
, EXT_FIRST_INDEX(path
[i
].p_hdr
),
2646 if (ext4_ext_more_to_rm(path
+ i
)) {
2647 struct buffer_head
*bh
;
2648 /* go to the next level */
2649 ext_debug("move to level %d (block %llu)\n",
2650 i
+ 1, ext4_idx_pblock(path
[i
].p_idx
));
2651 memset(path
+ i
+ 1, 0, sizeof(*path
));
2652 bh
= sb_bread(sb
, ext4_idx_pblock(path
[i
].p_idx
));
2654 /* should we reset i_size? */
2658 if (WARN_ON(i
+ 1 > depth
)) {
2662 if (ext4_ext_check(inode
, ext_block_hdr(bh
),
2667 path
[i
+ 1].p_bh
= bh
;
2669 /* save actual number of indexes since this
2670 * number is changed at the next iteration */
2671 path
[i
].p_block
= le16_to_cpu(path
[i
].p_hdr
->eh_entries
);
2674 /* we finished processing this index, go up */
2675 if (path
[i
].p_hdr
->eh_entries
== 0 && i
> 0) {
2676 /* index is empty, remove it;
2677 * handle must be already prepared by the
2678 * truncatei_leaf() */
2679 err
= ext4_ext_rm_idx(handle
, inode
, path
+ i
);
2681 /* root level has p_bh == NULL, brelse() eats this */
2682 brelse(path
[i
].p_bh
);
2683 path
[i
].p_bh
= NULL
;
2685 ext_debug("return to level %d\n", i
);
2689 /* TODO: flexible tree reduction should be here */
2690 if (path
->p_hdr
->eh_entries
== 0) {
2692 * truncate to zero freed all the tree,
2693 * so we need to correct eh_depth
2695 err
= ext4_ext_get_access(handle
, inode
, path
);
2697 ext_inode_hdr(inode
)->eh_depth
= 0;
2698 ext_inode_hdr(inode
)->eh_max
=
2699 cpu_to_le16(ext4_ext_space_root(inode
, 0));
2700 err
= ext4_ext_dirty(handle
, inode
, path
);
2704 ext4_ext_drop_refs(path
);
2708 ext4_journal_stop(handle
);
2714 * called at mount time
2716 void ext4_ext_init(struct super_block
*sb
)
2719 * possible initialization would be here
2722 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_EXTENTS
)) {
2723 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2724 printk(KERN_INFO
"EXT4-fs: file extents enabled");
2725 #ifdef AGGRESSIVE_TEST
2726 printk(", aggressive tests");
2728 #ifdef CHECK_BINSEARCH
2729 printk(", check binsearch");
2731 #ifdef EXTENTS_STATS
2736 #ifdef EXTENTS_STATS
2737 spin_lock_init(&EXT4_SB(sb
)->s_ext_stats_lock
);
2738 EXT4_SB(sb
)->s_ext_min
= 1 << 30;
2739 EXT4_SB(sb
)->s_ext_max
= 0;
2745 * called at umount time
2747 void ext4_ext_release(struct super_block
*sb
)
2749 if (!EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_EXTENTS
))
2752 #ifdef EXTENTS_STATS
2753 if (EXT4_SB(sb
)->s_ext_blocks
&& EXT4_SB(sb
)->s_ext_extents
) {
2754 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2755 printk(KERN_ERR
"EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2756 sbi
->s_ext_blocks
, sbi
->s_ext_extents
,
2757 sbi
->s_ext_blocks
/ sbi
->s_ext_extents
);
2758 printk(KERN_ERR
"EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2759 sbi
->s_ext_min
, sbi
->s_ext_max
, sbi
->s_depth_max
);
2764 /* FIXME!! we need to try to merge to left or right after zero-out */
2765 static int ext4_ext_zeroout(struct inode
*inode
, struct ext4_extent
*ex
)
2767 ext4_fsblk_t ee_pblock
;
2768 unsigned int ee_len
;
2771 ee_len
= ext4_ext_get_actual_len(ex
);
2772 ee_pblock
= ext4_ext_pblock(ex
);
2774 ret
= sb_issue_zeroout(inode
->i_sb
, ee_pblock
, ee_len
, GFP_NOFS
);
2782 * used by extent splitting.
2784 #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
2786 #define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
2787 #define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
2790 * ext4_split_extent_at() splits an extent at given block.
2792 * @handle: the journal handle
2793 * @inode: the file inode
2794 * @path: the path to the extent
2795 * @split: the logical block where the extent is splitted.
2796 * @split_flags: indicates if the extent could be zeroout if split fails, and
2797 * the states(init or uninit) of new extents.
2798 * @flags: flags used to insert new extent to extent tree.
2801 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
2802 * of which are deterimined by split_flag.
2804 * There are two cases:
2805 * a> the extent are splitted into two extent.
2806 * b> split is not needed, and just mark the extent.
2808 * return 0 on success.
2810 static int ext4_split_extent_at(handle_t
*handle
,
2811 struct inode
*inode
,
2812 struct ext4_ext_path
*path
,
2817 ext4_fsblk_t newblock
;
2818 ext4_lblk_t ee_block
;
2819 struct ext4_extent
*ex
, newex
, orig_ex
;
2820 struct ext4_extent
*ex2
= NULL
;
2821 unsigned int ee_len
, depth
;
2824 ext_debug("ext4_split_extents_at: inode %lu, logical"
2825 "block %llu\n", inode
->i_ino
, (unsigned long long)split
);
2827 ext4_ext_show_leaf(inode
, path
);
2829 depth
= ext_depth(inode
);
2830 ex
= path
[depth
].p_ext
;
2831 ee_block
= le32_to_cpu(ex
->ee_block
);
2832 ee_len
= ext4_ext_get_actual_len(ex
);
2833 newblock
= split
- ee_block
+ ext4_ext_pblock(ex
);
2835 BUG_ON(split
< ee_block
|| split
>= (ee_block
+ ee_len
));
2837 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
2841 if (split
== ee_block
) {
2843 * case b: block @split is the block that the extent begins with
2844 * then we just change the state of the extent, and splitting
2847 if (split_flag
& EXT4_EXT_MARK_UNINIT2
)
2848 ext4_ext_mark_uninitialized(ex
);
2850 ext4_ext_mark_initialized(ex
);
2852 if (!(flags
& EXT4_GET_BLOCKS_PRE_IO
))
2853 ext4_ext_try_to_merge(inode
, path
, ex
);
2855 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
2860 memcpy(&orig_ex
, ex
, sizeof(orig_ex
));
2861 ex
->ee_len
= cpu_to_le16(split
- ee_block
);
2862 if (split_flag
& EXT4_EXT_MARK_UNINIT1
)
2863 ext4_ext_mark_uninitialized(ex
);
2866 * path may lead to new leaf, not to original leaf any more
2867 * after ext4_ext_insert_extent() returns,
2869 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
2871 goto fix_extent_len
;
2874 ex2
->ee_block
= cpu_to_le32(split
);
2875 ex2
->ee_len
= cpu_to_le16(ee_len
- (split
- ee_block
));
2876 ext4_ext_store_pblock(ex2
, newblock
);
2877 if (split_flag
& EXT4_EXT_MARK_UNINIT2
)
2878 ext4_ext_mark_uninitialized(ex2
);
2880 err
= ext4_ext_insert_extent(handle
, inode
, path
, &newex
, flags
);
2881 if (err
== -ENOSPC
&& (EXT4_EXT_MAY_ZEROOUT
& split_flag
)) {
2882 err
= ext4_ext_zeroout(inode
, &orig_ex
);
2884 goto fix_extent_len
;
2885 /* update the extent length and mark as initialized */
2886 ex
->ee_len
= cpu_to_le32(ee_len
);
2887 ext4_ext_try_to_merge(inode
, path
, ex
);
2888 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
2891 goto fix_extent_len
;
2894 ext4_ext_show_leaf(inode
, path
);
2898 ex
->ee_len
= orig_ex
.ee_len
;
2899 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2904 * ext4_split_extents() splits an extent and mark extent which is covered
2905 * by @map as split_flags indicates
2907 * It may result in splitting the extent into multiple extents (upto three)
2908 * There are three possibilities:
2909 * a> There is no split required
2910 * b> Splits in two extents: Split is happening at either end of the extent
2911 * c> Splits in three extents: Somone is splitting in middle of the extent
2914 static int ext4_split_extent(handle_t
*handle
,
2915 struct inode
*inode
,
2916 struct ext4_ext_path
*path
,
2917 struct ext4_map_blocks
*map
,
2921 ext4_lblk_t ee_block
;
2922 struct ext4_extent
*ex
;
2923 unsigned int ee_len
, depth
;
2926 int split_flag1
, flags1
;
2928 depth
= ext_depth(inode
);
2929 ex
= path
[depth
].p_ext
;
2930 ee_block
= le32_to_cpu(ex
->ee_block
);
2931 ee_len
= ext4_ext_get_actual_len(ex
);
2932 uninitialized
= ext4_ext_is_uninitialized(ex
);
2934 if (map
->m_lblk
+ map
->m_len
< ee_block
+ ee_len
) {
2935 split_flag1
= split_flag
& EXT4_EXT_MAY_ZEROOUT
?
2936 EXT4_EXT_MAY_ZEROOUT
: 0;
2937 flags1
= flags
| EXT4_GET_BLOCKS_PRE_IO
;
2939 split_flag1
|= EXT4_EXT_MARK_UNINIT1
|
2940 EXT4_EXT_MARK_UNINIT2
;
2941 err
= ext4_split_extent_at(handle
, inode
, path
,
2942 map
->m_lblk
+ map
->m_len
, split_flag1
, flags1
);
2947 ext4_ext_drop_refs(path
);
2948 path
= ext4_ext_find_extent(inode
, map
->m_lblk
, path
);
2950 return PTR_ERR(path
);
2952 if (map
->m_lblk
>= ee_block
) {
2953 split_flag1
= split_flag
& EXT4_EXT_MAY_ZEROOUT
?
2954 EXT4_EXT_MAY_ZEROOUT
: 0;
2956 split_flag1
|= EXT4_EXT_MARK_UNINIT1
;
2957 if (split_flag
& EXT4_EXT_MARK_UNINIT2
)
2958 split_flag1
|= EXT4_EXT_MARK_UNINIT2
;
2959 err
= ext4_split_extent_at(handle
, inode
, path
,
2960 map
->m_lblk
, split_flag1
, flags
);
2965 ext4_ext_show_leaf(inode
, path
);
2967 return err
? err
: map
->m_len
;
2970 #define EXT4_EXT_ZERO_LEN 7
2972 * This function is called by ext4_ext_map_blocks() if someone tries to write
2973 * to an uninitialized extent. It may result in splitting the uninitialized
2974 * extent into multiple extents (up to three - one initialized and two
2976 * There are three possibilities:
2977 * a> There is no split required: Entire extent should be initialized
2978 * b> Splits in two extents: Write is happening at either end of the extent
2979 * c> Splits in three extents: Somone is writing in middle of the extent
2981 static int ext4_ext_convert_to_initialized(handle_t
*handle
,
2982 struct inode
*inode
,
2983 struct ext4_map_blocks
*map
,
2984 struct ext4_ext_path
*path
)
2986 struct ext4_map_blocks split_map
;
2987 struct ext4_extent zero_ex
;
2988 struct ext4_extent
*ex
;
2989 ext4_lblk_t ee_block
, eof_block
;
2990 unsigned int allocated
, ee_len
, depth
;
2994 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
2995 "block %llu, max_blocks %u\n", inode
->i_ino
,
2996 (unsigned long long)map
->m_lblk
, map
->m_len
);
2998 eof_block
= (inode
->i_size
+ inode
->i_sb
->s_blocksize
- 1) >>
2999 inode
->i_sb
->s_blocksize_bits
;
3000 if (eof_block
< map
->m_lblk
+ map
->m_len
)
3001 eof_block
= map
->m_lblk
+ map
->m_len
;
3003 depth
= ext_depth(inode
);
3004 ex
= path
[depth
].p_ext
;
3005 ee_block
= le32_to_cpu(ex
->ee_block
);
3006 ee_len
= ext4_ext_get_actual_len(ex
);
3007 allocated
= ee_len
- (map
->m_lblk
- ee_block
);
3009 WARN_ON(map
->m_lblk
< ee_block
);
3011 * It is safe to convert extent to initialized via explicit
3012 * zeroout only if extent is fully insde i_size or new_size.
3014 split_flag
|= ee_block
+ ee_len
<= eof_block
? EXT4_EXT_MAY_ZEROOUT
: 0;
3016 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
3017 if (ee_len
<= 2*EXT4_EXT_ZERO_LEN
&&
3018 (EXT4_EXT_MAY_ZEROOUT
& split_flag
)) {
3019 err
= ext4_ext_zeroout(inode
, ex
);
3023 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
3026 ext4_ext_mark_initialized(ex
);
3027 ext4_ext_try_to_merge(inode
, path
, ex
);
3028 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
3034 * 1. split the extent into three extents.
3035 * 2. split the extent into two extents, zeroout the first half.
3036 * 3. split the extent into two extents, zeroout the second half.
3037 * 4. split the extent into two extents with out zeroout.
3039 split_map
.m_lblk
= map
->m_lblk
;
3040 split_map
.m_len
= map
->m_len
;
3042 if (allocated
> map
->m_len
) {
3043 if (allocated
<= EXT4_EXT_ZERO_LEN
&&
3044 (EXT4_EXT_MAY_ZEROOUT
& split_flag
)) {
3047 cpu_to_le32(map
->m_lblk
);
3048 zero_ex
.ee_len
= cpu_to_le16(allocated
);
3049 ext4_ext_store_pblock(&zero_ex
,
3050 ext4_ext_pblock(ex
) + map
->m_lblk
- ee_block
);
3051 err
= ext4_ext_zeroout(inode
, &zero_ex
);
3054 split_map
.m_lblk
= map
->m_lblk
;
3055 split_map
.m_len
= allocated
;
3056 } else if ((map
->m_lblk
- ee_block
+ map
->m_len
<
3057 EXT4_EXT_ZERO_LEN
) &&
3058 (EXT4_EXT_MAY_ZEROOUT
& split_flag
)) {
3060 if (map
->m_lblk
!= ee_block
) {
3061 zero_ex
.ee_block
= ex
->ee_block
;
3062 zero_ex
.ee_len
= cpu_to_le16(map
->m_lblk
-
3064 ext4_ext_store_pblock(&zero_ex
,
3065 ext4_ext_pblock(ex
));
3066 err
= ext4_ext_zeroout(inode
, &zero_ex
);
3071 split_map
.m_lblk
= ee_block
;
3072 split_map
.m_len
= map
->m_lblk
- ee_block
+ map
->m_len
;
3073 allocated
= map
->m_len
;
3077 allocated
= ext4_split_extent(handle
, inode
, path
,
3078 &split_map
, split_flag
, 0);
3083 return err
? err
: allocated
;
3087 * This function is called by ext4_ext_map_blocks() from
3088 * ext4_get_blocks_dio_write() when DIO to write
3089 * to an uninitialized extent.
3091 * Writing to an uninitialized extent may result in splitting the uninitialized
3092 * extent into multiple /initialized uninitialized extents (up to three)
3093 * There are three possibilities:
3094 * a> There is no split required: Entire extent should be uninitialized
3095 * b> Splits in two extents: Write is happening at either end of the extent
3096 * c> Splits in three extents: Somone is writing in middle of the extent
3098 * One of more index blocks maybe needed if the extent tree grow after
3099 * the uninitialized extent split. To prevent ENOSPC occur at the IO
3100 * complete, we need to split the uninitialized extent before DIO submit
3101 * the IO. The uninitialized extent called at this time will be split
3102 * into three uninitialized extent(at most). After IO complete, the part
3103 * being filled will be convert to initialized by the end_io callback function
3104 * via ext4_convert_unwritten_extents().
3106 * Returns the size of uninitialized extent to be written on success.
3108 static int ext4_split_unwritten_extents(handle_t
*handle
,
3109 struct inode
*inode
,
3110 struct ext4_map_blocks
*map
,
3111 struct ext4_ext_path
*path
,
3114 ext4_lblk_t eof_block
;
3115 ext4_lblk_t ee_block
;
3116 struct ext4_extent
*ex
;
3117 unsigned int ee_len
;
3118 int split_flag
= 0, depth
;
3120 ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3121 "block %llu, max_blocks %u\n", inode
->i_ino
,
3122 (unsigned long long)map
->m_lblk
, map
->m_len
);
3124 eof_block
= (inode
->i_size
+ inode
->i_sb
->s_blocksize
- 1) >>
3125 inode
->i_sb
->s_blocksize_bits
;
3126 if (eof_block
< map
->m_lblk
+ map
->m_len
)
3127 eof_block
= map
->m_lblk
+ map
->m_len
;
3129 * It is safe to convert extent to initialized via explicit
3130 * zeroout only if extent is fully insde i_size or new_size.
3132 depth
= ext_depth(inode
);
3133 ex
= path
[depth
].p_ext
;
3134 ee_block
= le32_to_cpu(ex
->ee_block
);
3135 ee_len
= ext4_ext_get_actual_len(ex
);
3137 split_flag
|= ee_block
+ ee_len
<= eof_block
? EXT4_EXT_MAY_ZEROOUT
: 0;
3138 split_flag
|= EXT4_EXT_MARK_UNINIT2
;
3140 flags
|= EXT4_GET_BLOCKS_PRE_IO
;
3141 return ext4_split_extent(handle
, inode
, path
, map
, split_flag
, flags
);
3144 static int ext4_convert_unwritten_extents_endio(handle_t
*handle
,
3145 struct inode
*inode
,
3146 struct ext4_ext_path
*path
)
3148 struct ext4_extent
*ex
;
3152 depth
= ext_depth(inode
);
3153 ex
= path
[depth
].p_ext
;
3155 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3156 "block %llu, max_blocks %u\n", inode
->i_ino
,
3157 (unsigned long long)le32_to_cpu(ex
->ee_block
),
3158 ext4_ext_get_actual_len(ex
));
3160 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
3163 /* first mark the extent as initialized */
3164 ext4_ext_mark_initialized(ex
);
3166 /* note: ext4_ext_correct_indexes() isn't needed here because
3167 * borders are not changed
3169 ext4_ext_try_to_merge(inode
, path
, ex
);
3171 /* Mark modified extent as dirty */
3172 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
3174 ext4_ext_show_leaf(inode
, path
);
3178 static void unmap_underlying_metadata_blocks(struct block_device
*bdev
,
3179 sector_t block
, int count
)
3182 for (i
= 0; i
< count
; i
++)
3183 unmap_underlying_metadata(bdev
, block
+ i
);
3187 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3189 static int check_eofblocks_fl(handle_t
*handle
, struct inode
*inode
,
3191 struct ext4_ext_path
*path
,
3195 struct ext4_extent_header
*eh
;
3196 struct ext4_extent
*last_ex
;
3198 if (!ext4_test_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
))
3201 depth
= ext_depth(inode
);
3202 eh
= path
[depth
].p_hdr
;
3204 if (unlikely(!eh
->eh_entries
)) {
3205 EXT4_ERROR_INODE(inode
, "eh->eh_entries == 0 and "
3206 "EOFBLOCKS_FL set");
3209 last_ex
= EXT_LAST_EXTENT(eh
);
3211 * We should clear the EOFBLOCKS_FL flag if we are writing the
3212 * last block in the last extent in the file. We test this by
3213 * first checking to see if the caller to
3214 * ext4_ext_get_blocks() was interested in the last block (or
3215 * a block beyond the last block) in the current extent. If
3216 * this turns out to be false, we can bail out from this
3217 * function immediately.
3219 if (lblk
+ len
< le32_to_cpu(last_ex
->ee_block
) +
3220 ext4_ext_get_actual_len(last_ex
))
3223 * If the caller does appear to be planning to write at or
3224 * beyond the end of the current extent, we then test to see
3225 * if the current extent is the last extent in the file, by
3226 * checking to make sure it was reached via the rightmost node
3227 * at each level of the tree.
3229 for (i
= depth
-1; i
>= 0; i
--)
3230 if (path
[i
].p_idx
!= EXT_LAST_INDEX(path
[i
].p_hdr
))
3232 ext4_clear_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
);
3233 return ext4_mark_inode_dirty(handle
, inode
);
3237 ext4_ext_handle_uninitialized_extents(handle_t
*handle
, struct inode
*inode
,
3238 struct ext4_map_blocks
*map
,
3239 struct ext4_ext_path
*path
, int flags
,
3240 unsigned int allocated
, ext4_fsblk_t newblock
)
3244 ext4_io_end_t
*io
= EXT4_I(inode
)->cur_aio_dio
;
3246 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical"
3247 "block %llu, max_blocks %u, flags %d, allocated %u",
3248 inode
->i_ino
, (unsigned long long)map
->m_lblk
, map
->m_len
,
3250 ext4_ext_show_leaf(inode
, path
);
3252 /* get_block() before submit the IO, split the extent */
3253 if ((flags
& EXT4_GET_BLOCKS_PRE_IO
)) {
3254 ret
= ext4_split_unwritten_extents(handle
, inode
, map
,
3257 * Flag the inode(non aio case) or end_io struct (aio case)
3258 * that this IO needs to conversion to written when IO is
3261 if (io
&& !(io
->flag
& EXT4_IO_END_UNWRITTEN
)) {
3262 io
->flag
= EXT4_IO_END_UNWRITTEN
;
3263 atomic_inc(&EXT4_I(inode
)->i_aiodio_unwritten
);
3265 ext4_set_inode_state(inode
, EXT4_STATE_DIO_UNWRITTEN
);
3266 if (ext4_should_dioread_nolock(inode
))
3267 map
->m_flags
|= EXT4_MAP_UNINIT
;
3270 /* IO end_io complete, convert the filled extent to written */
3271 if ((flags
& EXT4_GET_BLOCKS_CONVERT
)) {
3272 ret
= ext4_convert_unwritten_extents_endio(handle
, inode
,
3275 ext4_update_inode_fsync_trans(handle
, inode
, 1);
3276 err
= check_eofblocks_fl(handle
, inode
, map
->m_lblk
,
3282 /* buffered IO case */
3284 * repeat fallocate creation request
3285 * we already have an unwritten extent
3287 if (flags
& EXT4_GET_BLOCKS_UNINIT_EXT
)
3290 /* buffered READ or buffered write_begin() lookup */
3291 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0) {
3293 * We have blocks reserved already. We
3294 * return allocated blocks so that delalloc
3295 * won't do block reservation for us. But
3296 * the buffer head will be unmapped so that
3297 * a read from the block returns 0s.
3299 map
->m_flags
|= EXT4_MAP_UNWRITTEN
;
3303 /* buffered write, writepage time, convert*/
3304 ret
= ext4_ext_convert_to_initialized(handle
, inode
, map
, path
);
3306 ext4_update_inode_fsync_trans(handle
, inode
, 1);
3307 err
= check_eofblocks_fl(handle
, inode
, map
->m_lblk
, path
,
3319 map
->m_flags
|= EXT4_MAP_NEW
;
3321 * if we allocated more blocks than requested
3322 * we need to make sure we unmap the extra block
3323 * allocated. The actual needed block will get
3324 * unmapped later when we find the buffer_head marked
3327 if (allocated
> map
->m_len
) {
3328 unmap_underlying_metadata_blocks(inode
->i_sb
->s_bdev
,
3329 newblock
+ map
->m_len
,
3330 allocated
- map
->m_len
);
3331 allocated
= map
->m_len
;
3335 * If we have done fallocate with the offset that is already
3336 * delayed allocated, we would have block reservation
3337 * and quota reservation done in the delayed write path.
3338 * But fallocate would have already updated quota and block
3339 * count for this offset. So cancel these reservation
3341 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
3342 ext4_da_update_reserve_space(inode
, allocated
, 0);
3345 map
->m_flags
|= EXT4_MAP_MAPPED
;
3347 if (allocated
> map
->m_len
)
3348 allocated
= map
->m_len
;
3349 ext4_ext_show_leaf(inode
, path
);
3350 map
->m_pblk
= newblock
;
3351 map
->m_len
= allocated
;
3354 ext4_ext_drop_refs(path
);
3357 return err
? err
: allocated
;
3361 * get_implied_cluster_alloc - check to see if the requested
3362 * allocation (in the map structure) overlaps with a cluster already
3363 * allocated in an extent.
3364 * @sbi The ext4-specific superblock structure
3365 * @map The requested lblk->pblk mapping
3366 * @ex The extent structure which might contain an implied
3367 * cluster allocation
3369 * This function is called by ext4_ext_map_blocks() after we failed to
3370 * find blocks that were already in the inode's extent tree. Hence,
3371 * we know that the beginning of the requested region cannot overlap
3372 * the extent from the inode's extent tree. There are three cases we
3373 * want to catch. The first is this case:
3375 * |--- cluster # N--|
3376 * |--- extent ---| |---- requested region ---|
3379 * The second case that we need to test for is this one:
3381 * |--------- cluster # N ----------------|
3382 * |--- requested region --| |------- extent ----|
3383 * |=======================|
3385 * The third case is when the requested region lies between two extents
3386 * within the same cluster:
3387 * |------------- cluster # N-------------|
3388 * |----- ex -----| |---- ex_right ----|
3389 * |------ requested region ------|
3390 * |================|
3392 * In each of the above cases, we need to set the map->m_pblk and
3393 * map->m_len so it corresponds to the return the extent labelled as
3394 * "|====|" from cluster #N, since it is already in use for data in
3395 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
3396 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
3397 * as a new "allocated" block region. Otherwise, we will return 0 and
3398 * ext4_ext_map_blocks() will then allocate one or more new clusters
3399 * by calling ext4_mb_new_blocks().
3401 static int get_implied_cluster_alloc(struct ext4_sb_info
*sbi
,
3402 struct ext4_map_blocks
*map
,
3403 struct ext4_extent
*ex
,
3404 struct ext4_ext_path
*path
)
3406 ext4_lblk_t c_offset
= map
->m_lblk
& (sbi
->s_cluster_ratio
-1);
3407 ext4_lblk_t ex_cluster_start
, ex_cluster_end
;
3408 ext4_lblk_t rr_cluster_start
, rr_cluster_end
;
3409 ext4_lblk_t ee_block
= le32_to_cpu(ex
->ee_block
);
3410 ext4_fsblk_t ee_start
= ext4_ext_pblock(ex
);
3411 unsigned short ee_len
= ext4_ext_get_actual_len(ex
);
3413 /* The extent passed in that we are trying to match */
3414 ex_cluster_start
= EXT4_B2C(sbi
, ee_block
);
3415 ex_cluster_end
= EXT4_B2C(sbi
, ee_block
+ ee_len
- 1);
3417 /* The requested region passed into ext4_map_blocks() */
3418 rr_cluster_start
= EXT4_B2C(sbi
, map
->m_lblk
);
3419 rr_cluster_end
= EXT4_B2C(sbi
, map
->m_lblk
+ map
->m_len
- 1);
3421 if ((rr_cluster_start
== ex_cluster_end
) ||
3422 (rr_cluster_start
== ex_cluster_start
)) {
3423 if (rr_cluster_start
== ex_cluster_end
)
3424 ee_start
+= ee_len
- 1;
3425 map
->m_pblk
= (ee_start
& ~(sbi
->s_cluster_ratio
- 1)) +
3427 map
->m_len
= min(map
->m_len
,
3428 (unsigned) sbi
->s_cluster_ratio
- c_offset
);
3430 * Check for and handle this case:
3432 * |--------- cluster # N-------------|
3433 * |------- extent ----|
3434 * |--- requested region ---|
3438 if (map
->m_lblk
< ee_block
)
3439 map
->m_len
= min(map
->m_len
, ee_block
- map
->m_lblk
);
3442 * Check for the case where there is already another allocated
3443 * block to the right of 'ex' but before the end of the cluster.
3445 * |------------- cluster # N-------------|
3446 * |----- ex -----| |---- ex_right ----|
3447 * |------ requested region ------|
3448 * |================|
3450 if (map
->m_lblk
> ee_block
) {
3451 ext4_lblk_t next
= ext4_ext_next_allocated_block(path
);
3452 map
->m_len
= min(map
->m_len
, next
- map
->m_lblk
);
3461 * Block allocation/map/preallocation routine for extents based files
3464 * Need to be called with
3465 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
3466 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
3468 * return > 0, number of of blocks already mapped/allocated
3469 * if create == 0 and these are pre-allocated blocks
3470 * buffer head is unmapped
3471 * otherwise blocks are mapped
3473 * return = 0, if plain look up failed (blocks have not been allocated)
3474 * buffer head is unmapped
3476 * return < 0, error case.
3478 int ext4_ext_map_blocks(handle_t
*handle
, struct inode
*inode
,
3479 struct ext4_map_blocks
*map
, int flags
)
3481 struct ext4_ext_path
*path
= NULL
;
3482 struct ext4_extent newex
, *ex
, *ex2
;
3483 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
3484 ext4_fsblk_t newblock
= 0;
3485 int free_on_err
= 0, err
= 0, depth
, ret
;
3486 unsigned int allocated
= 0, offset
= 0;
3487 unsigned int punched_out
= 0;
3488 unsigned int result
= 0;
3489 struct ext4_allocation_request ar
;
3490 ext4_io_end_t
*io
= EXT4_I(inode
)->cur_aio_dio
;
3491 ext4_lblk_t cluster_offset
;
3492 struct ext4_map_blocks punch_map
;
3494 ext_debug("blocks %u/%u requested for inode %lu\n",
3495 map
->m_lblk
, map
->m_len
, inode
->i_ino
);
3496 trace_ext4_ext_map_blocks_enter(inode
, map
->m_lblk
, map
->m_len
, flags
);
3498 /* check in cache */
3499 if (!(flags
& EXT4_GET_BLOCKS_PUNCH_OUT_EXT
) &&
3500 ext4_ext_in_cache(inode
, map
->m_lblk
, &newex
)) {
3501 if (!newex
.ee_start_lo
&& !newex
.ee_start_hi
) {
3502 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0) {
3504 * block isn't allocated yet and
3505 * user doesn't want to allocate it
3509 /* we should allocate requested block */
3511 /* block is already allocated */
3512 newblock
= map
->m_lblk
3513 - le32_to_cpu(newex
.ee_block
)
3514 + ext4_ext_pblock(&newex
);
3515 /* number of remaining blocks in the extent */
3516 allocated
= ext4_ext_get_actual_len(&newex
) -
3517 (map
->m_lblk
- le32_to_cpu(newex
.ee_block
));
3522 /* find extent for this block */
3523 path
= ext4_ext_find_extent(inode
, map
->m_lblk
, NULL
);
3525 err
= PTR_ERR(path
);
3530 depth
= ext_depth(inode
);
3533 * consistent leaf must not be empty;
3534 * this situation is possible, though, _during_ tree modification;
3535 * this is why assert can't be put in ext4_ext_find_extent()
3537 if (unlikely(path
[depth
].p_ext
== NULL
&& depth
!= 0)) {
3538 EXT4_ERROR_INODE(inode
, "bad extent address "
3539 "lblock: %lu, depth: %d pblock %lld",
3540 (unsigned long) map
->m_lblk
, depth
,
3541 path
[depth
].p_block
);
3546 ex
= path
[depth
].p_ext
;
3548 ext4_lblk_t ee_block
= le32_to_cpu(ex
->ee_block
);
3549 ext4_fsblk_t ee_start
= ext4_ext_pblock(ex
);
3550 unsigned short ee_len
;
3553 * Uninitialized extents are treated as holes, except that
3554 * we split out initialized portions during a write.
3556 ee_len
= ext4_ext_get_actual_len(ex
);
3557 /* if found extent covers block, simply return it */
3558 if (in_range(map
->m_lblk
, ee_block
, ee_len
)) {
3559 ext4_fsblk_t partial_cluster
= 0;
3561 newblock
= map
->m_lblk
- ee_block
+ ee_start
;
3562 /* number of remaining blocks in the extent */
3563 allocated
= ee_len
- (map
->m_lblk
- ee_block
);
3564 ext_debug("%u fit into %u:%d -> %llu\n", map
->m_lblk
,
3565 ee_block
, ee_len
, newblock
);
3567 if ((flags
& EXT4_GET_BLOCKS_PUNCH_OUT_EXT
) == 0) {
3569 * Do not put uninitialized extent
3572 if (!ext4_ext_is_uninitialized(ex
)) {
3573 ext4_ext_put_in_cache(inode
, ee_block
,
3577 ret
= ext4_ext_handle_uninitialized_extents(
3578 handle
, inode
, map
, path
, flags
,
3579 allocated
, newblock
);
3584 * Punch out the map length, but only to the
3587 punched_out
= allocated
< map
->m_len
?
3588 allocated
: map
->m_len
;
3591 * Sense extents need to be converted to
3592 * uninitialized, they must fit in an
3593 * uninitialized extent
3595 if (punched_out
> EXT_UNINIT_MAX_LEN
)
3596 punched_out
= EXT_UNINIT_MAX_LEN
;
3598 punch_map
.m_lblk
= map
->m_lblk
;
3599 punch_map
.m_pblk
= newblock
;
3600 punch_map
.m_len
= punched_out
;
3601 punch_map
.m_flags
= 0;
3603 /* Check to see if the extent needs to be split */
3604 if (punch_map
.m_len
!= ee_len
||
3605 punch_map
.m_lblk
!= ee_block
) {
3607 ret
= ext4_split_extent(handle
, inode
,
3608 path
, &punch_map
, 0,
3609 EXT4_GET_BLOCKS_PUNCH_OUT_EXT
|
3610 EXT4_GET_BLOCKS_PRE_IO
);
3617 * find extent for the block at
3618 * the start of the hole
3620 ext4_ext_drop_refs(path
);
3623 path
= ext4_ext_find_extent(inode
,
3626 err
= PTR_ERR(path
);
3631 depth
= ext_depth(inode
);
3632 ex
= path
[depth
].p_ext
;
3633 ee_len
= ext4_ext_get_actual_len(ex
);
3634 ee_block
= le32_to_cpu(ex
->ee_block
);
3635 ee_start
= ext4_ext_pblock(ex
);
3639 ext4_ext_mark_uninitialized(ex
);
3641 ext4_ext_invalidate_cache(inode
);
3643 err
= ext4_ext_rm_leaf(handle
, inode
, path
,
3644 &partial_cluster
, map
->m_lblk
,
3645 map
->m_lblk
+ punched_out
);
3647 if (!err
&& path
->p_hdr
->eh_entries
== 0) {
3649 * Punch hole freed all of this sub tree,
3650 * so we need to correct eh_depth
3652 err
= ext4_ext_get_access(handle
, inode
, path
);
3654 ext_inode_hdr(inode
)->eh_depth
= 0;
3655 ext_inode_hdr(inode
)->eh_max
=
3656 cpu_to_le16(ext4_ext_space_root(
3659 err
= ext4_ext_dirty(
3660 handle
, inode
, path
);
3669 * requested block isn't allocated yet;
3670 * we couldn't try to create block if create flag is zero
3672 if ((flags
& EXT4_GET_BLOCKS_CREATE
) == 0) {
3674 * put just found gap into cache to speed up
3675 * subsequent requests
3677 ext4_ext_put_gap_in_cache(inode
, path
, map
->m_lblk
);
3682 * Okay, we need to do block allocation.
3684 newex
.ee_block
= cpu_to_le32(map
->m_lblk
);
3685 cluster_offset
= map
->m_lblk
& (sbi
->s_cluster_ratio
-1);
3688 * If we are doing bigalloc, check to see if the extent returned
3689 * by ext4_ext_find_extent() implies a cluster we can use.
3691 if (cluster_offset
&& ex
&&
3692 get_implied_cluster_alloc(sbi
, map
, ex
, path
)) {
3693 ar
.len
= allocated
= map
->m_len
;
3694 newblock
= map
->m_pblk
;
3695 goto got_allocated_blocks
;
3698 /* find neighbour allocated blocks */
3699 ar
.lleft
= map
->m_lblk
;
3700 err
= ext4_ext_search_left(inode
, path
, &ar
.lleft
, &ar
.pleft
);
3703 ar
.lright
= map
->m_lblk
;
3705 err
= ext4_ext_search_right(inode
, path
, &ar
.lright
, &ar
.pright
, &ex2
);
3709 /* Check if the extent after searching to the right implies a
3710 * cluster we can use. */
3711 if ((sbi
->s_cluster_ratio
> 1) && ex2
&&
3712 get_implied_cluster_alloc(sbi
, map
, ex2
, path
)) {
3713 ar
.len
= allocated
= map
->m_len
;
3714 newblock
= map
->m_pblk
;
3715 goto got_allocated_blocks
;
3719 * See if request is beyond maximum number of blocks we can have in
3720 * a single extent. For an initialized extent this limit is
3721 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
3722 * EXT_UNINIT_MAX_LEN.
3724 if (map
->m_len
> EXT_INIT_MAX_LEN
&&
3725 !(flags
& EXT4_GET_BLOCKS_UNINIT_EXT
))
3726 map
->m_len
= EXT_INIT_MAX_LEN
;
3727 else if (map
->m_len
> EXT_UNINIT_MAX_LEN
&&
3728 (flags
& EXT4_GET_BLOCKS_UNINIT_EXT
))
3729 map
->m_len
= EXT_UNINIT_MAX_LEN
;
3731 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
3732 newex
.ee_len
= cpu_to_le16(map
->m_len
);
3733 err
= ext4_ext_check_overlap(sbi
, inode
, &newex
, path
);
3735 allocated
= ext4_ext_get_actual_len(&newex
);
3737 allocated
= map
->m_len
;
3739 /* allocate new block */
3741 ar
.goal
= ext4_ext_find_goal(inode
, path
, map
->m_lblk
);
3742 ar
.logical
= map
->m_lblk
;
3744 * We calculate the offset from the beginning of the cluster
3745 * for the logical block number, since when we allocate a
3746 * physical cluster, the physical block should start at the
3747 * same offset from the beginning of the cluster. This is
3748 * needed so that future calls to get_implied_cluster_alloc()
3751 offset
= map
->m_lblk
& (sbi
->s_cluster_ratio
- 1);
3752 ar
.len
= EXT4_NUM_B2C(sbi
, offset
+allocated
);
3754 ar
.logical
-= offset
;
3755 if (S_ISREG(inode
->i_mode
))
3756 ar
.flags
= EXT4_MB_HINT_DATA
;
3758 /* disable in-core preallocation for non-regular files */
3760 if (flags
& EXT4_GET_BLOCKS_NO_NORMALIZE
)
3761 ar
.flags
|= EXT4_MB_HINT_NOPREALLOC
;
3762 newblock
= ext4_mb_new_blocks(handle
, &ar
, &err
);
3765 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
3766 ar
.goal
, newblock
, allocated
);
3768 ar
.len
= EXT4_C2B(sbi
, ar
.len
) - offset
;
3769 if (ar
.len
> allocated
)
3772 got_allocated_blocks
:
3773 /* try to insert new extent into found leaf and return */
3774 ext4_ext_store_pblock(&newex
, newblock
+ offset
);
3775 newex
.ee_len
= cpu_to_le16(ar
.len
);
3776 /* Mark uninitialized */
3777 if (flags
& EXT4_GET_BLOCKS_UNINIT_EXT
){
3778 ext4_ext_mark_uninitialized(&newex
);
3780 * io_end structure was created for every IO write to an
3781 * uninitialized extent. To avoid unnecessary conversion,
3782 * here we flag the IO that really needs the conversion.
3783 * For non asycn direct IO case, flag the inode state
3784 * that we need to perform conversion when IO is done.
3786 if ((flags
& EXT4_GET_BLOCKS_PRE_IO
)) {
3787 if (io
&& !(io
->flag
& EXT4_IO_END_UNWRITTEN
)) {
3788 io
->flag
= EXT4_IO_END_UNWRITTEN
;
3789 atomic_inc(&EXT4_I(inode
)->i_aiodio_unwritten
);
3791 ext4_set_inode_state(inode
,
3792 EXT4_STATE_DIO_UNWRITTEN
);
3794 if (ext4_should_dioread_nolock(inode
))
3795 map
->m_flags
|= EXT4_MAP_UNINIT
;
3798 err
= check_eofblocks_fl(handle
, inode
, map
->m_lblk
, path
, ar
.len
);
3800 err
= ext4_ext_insert_extent(handle
, inode
, path
,
3802 if (err
&& free_on_err
) {
3803 int fb_flags
= flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
?
3804 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
: 0;
3805 /* free data blocks we just allocated */
3806 /* not a good idea to call discard here directly,
3807 * but otherwise we'd need to call it every free() */
3808 ext4_discard_preallocations(inode
);
3809 ext4_free_blocks(handle
, inode
, NULL
, ext4_ext_pblock(&newex
),
3810 ext4_ext_get_actual_len(&newex
), fb_flags
);
3814 /* previous routine could use block we allocated */
3815 newblock
= ext4_ext_pblock(&newex
);
3816 allocated
= ext4_ext_get_actual_len(&newex
);
3817 if (allocated
> map
->m_len
)
3818 allocated
= map
->m_len
;
3819 map
->m_flags
|= EXT4_MAP_NEW
;
3822 * Update reserved blocks/metadata blocks after successful
3823 * block allocation which had been deferred till now.
3825 if (flags
& EXT4_GET_BLOCKS_DELALLOC_RESERVE
)
3826 ext4_da_update_reserve_space(inode
, allocated
, 1);
3829 * Cache the extent and update transaction to commit on fdatasync only
3830 * when it is _not_ an uninitialized extent.
3832 if ((flags
& EXT4_GET_BLOCKS_UNINIT_EXT
) == 0) {
3833 ext4_ext_put_in_cache(inode
, map
->m_lblk
, allocated
, newblock
);
3834 ext4_update_inode_fsync_trans(handle
, inode
, 1);
3836 ext4_update_inode_fsync_trans(handle
, inode
, 0);
3838 if (allocated
> map
->m_len
)
3839 allocated
= map
->m_len
;
3840 ext4_ext_show_leaf(inode
, path
);
3841 map
->m_flags
|= EXT4_MAP_MAPPED
;
3842 map
->m_pblk
= newblock
;
3843 map
->m_len
= allocated
;
3846 ext4_ext_drop_refs(path
);
3849 trace_ext4_ext_map_blocks_exit(inode
, map
->m_lblk
,
3850 newblock
, map
->m_len
, err
? err
: allocated
);
3852 result
= (flags
& EXT4_GET_BLOCKS_PUNCH_OUT_EXT
) ?
3853 punched_out
: allocated
;
3855 return err
? err
: result
;
3858 void ext4_ext_truncate(struct inode
*inode
)
3860 struct address_space
*mapping
= inode
->i_mapping
;
3861 struct super_block
*sb
= inode
->i_sb
;
3862 ext4_lblk_t last_block
;
3868 * finish any pending end_io work so we won't run the risk of
3869 * converting any truncated blocks to initialized later
3871 ext4_flush_completed_IO(inode
);
3874 * probably first extent we're gonna free will be last in block
3876 err
= ext4_writepage_trans_blocks(inode
);
3877 handle
= ext4_journal_start(inode
, err
);
3881 if (inode
->i_size
% PAGE_CACHE_SIZE
!= 0) {
3882 page_len
= PAGE_CACHE_SIZE
-
3883 (inode
->i_size
& (PAGE_CACHE_SIZE
- 1));
3885 err
= ext4_discard_partial_page_buffers(handle
,
3886 mapping
, inode
->i_size
, page_len
, 0);
3892 if (ext4_orphan_add(handle
, inode
))
3895 down_write(&EXT4_I(inode
)->i_data_sem
);
3896 ext4_ext_invalidate_cache(inode
);
3898 ext4_discard_preallocations(inode
);
3901 * TODO: optimization is possible here.
3902 * Probably we need not scan at all,
3903 * because page truncation is enough.
3906 /* we have to know where to truncate from in crash case */
3907 EXT4_I(inode
)->i_disksize
= inode
->i_size
;
3908 ext4_mark_inode_dirty(handle
, inode
);
3910 last_block
= (inode
->i_size
+ sb
->s_blocksize
- 1)
3911 >> EXT4_BLOCK_SIZE_BITS(sb
);
3912 err
= ext4_ext_remove_space(inode
, last_block
);
3914 /* In a multi-transaction truncate, we only make the final
3915 * transaction synchronous.
3918 ext4_handle_sync(handle
);
3920 up_write(&EXT4_I(inode
)->i_data_sem
);
3924 * If this was a simple ftruncate() and the file will remain alive,
3925 * then we need to clear up the orphan record which we created above.
3926 * However, if this was a real unlink then we were called by
3927 * ext4_delete_inode(), and we allow that function to clean up the
3928 * orphan info for us.
3931 ext4_orphan_del(handle
, inode
);
3933 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
3934 ext4_mark_inode_dirty(handle
, inode
);
3935 ext4_journal_stop(handle
);
3938 static void ext4_falloc_update_inode(struct inode
*inode
,
3939 int mode
, loff_t new_size
, int update_ctime
)
3941 struct timespec now
;
3944 now
= current_fs_time(inode
->i_sb
);
3945 if (!timespec_equal(&inode
->i_ctime
, &now
))
3946 inode
->i_ctime
= now
;
3949 * Update only when preallocation was requested beyond
3952 if (!(mode
& FALLOC_FL_KEEP_SIZE
)) {
3953 if (new_size
> i_size_read(inode
))
3954 i_size_write(inode
, new_size
);
3955 if (new_size
> EXT4_I(inode
)->i_disksize
)
3956 ext4_update_i_disksize(inode
, new_size
);
3959 * Mark that we allocate beyond EOF so the subsequent truncate
3960 * can proceed even if the new size is the same as i_size.
3962 if (new_size
> i_size_read(inode
))
3963 ext4_set_inode_flag(inode
, EXT4_INODE_EOFBLOCKS
);
3969 * preallocate space for a file. This implements ext4's fallocate file
3970 * operation, which gets called from sys_fallocate system call.
3971 * For block-mapped files, posix_fallocate should fall back to the method
3972 * of writing zeroes to the required new blocks (the same behavior which is
3973 * expected for file systems which do not support fallocate() system call).
3975 long ext4_fallocate(struct file
*file
, int mode
, loff_t offset
, loff_t len
)
3977 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
3980 unsigned int max_blocks
;
3984 struct ext4_map_blocks map
;
3985 unsigned int credits
, blkbits
= inode
->i_blkbits
;
3988 * currently supporting (pre)allocate mode for extent-based
3991 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
3994 /* Return error if mode is not supported */
3995 if (mode
& ~(FALLOC_FL_KEEP_SIZE
| FALLOC_FL_PUNCH_HOLE
))
3998 if (mode
& FALLOC_FL_PUNCH_HOLE
)
3999 return ext4_punch_hole(file
, offset
, len
);
4001 trace_ext4_fallocate_enter(inode
, offset
, len
, mode
);
4002 map
.m_lblk
= offset
>> blkbits
;
4004 * We can't just convert len to max_blocks because
4005 * If blocksize = 4096 offset = 3072 and len = 2048
4007 max_blocks
= (EXT4_BLOCK_ALIGN(len
+ offset
, blkbits
) >> blkbits
)
4010 * credits to insert 1 extent into extent tree
4012 credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
4013 mutex_lock(&inode
->i_mutex
);
4014 ret
= inode_newsize_ok(inode
, (len
+ offset
));
4016 mutex_unlock(&inode
->i_mutex
);
4017 trace_ext4_fallocate_exit(inode
, offset
, max_blocks
, ret
);
4021 while (ret
>= 0 && ret
< max_blocks
) {
4022 map
.m_lblk
= map
.m_lblk
+ ret
;
4023 map
.m_len
= max_blocks
= max_blocks
- ret
;
4024 handle
= ext4_journal_start(inode
, credits
);
4025 if (IS_ERR(handle
)) {
4026 ret
= PTR_ERR(handle
);
4029 ret
= ext4_map_blocks(handle
, inode
, &map
,
4030 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT
|
4031 EXT4_GET_BLOCKS_NO_NORMALIZE
);
4035 printk(KERN_ERR
"%s: ext4_ext_map_blocks "
4036 "returned error inode#%lu, block=%u, "
4037 "max_blocks=%u", __func__
,
4038 inode
->i_ino
, map
.m_lblk
, max_blocks
);
4040 ext4_mark_inode_dirty(handle
, inode
);
4041 ret2
= ext4_journal_stop(handle
);
4044 if ((map
.m_lblk
+ ret
) >= (EXT4_BLOCK_ALIGN(offset
+ len
,
4045 blkbits
) >> blkbits
))
4046 new_size
= offset
+ len
;
4048 new_size
= ((loff_t
) map
.m_lblk
+ ret
) << blkbits
;
4050 ext4_falloc_update_inode(inode
, mode
, new_size
,
4051 (map
.m_flags
& EXT4_MAP_NEW
));
4052 ext4_mark_inode_dirty(handle
, inode
);
4053 ret2
= ext4_journal_stop(handle
);
4057 if (ret
== -ENOSPC
&&
4058 ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
4062 mutex_unlock(&inode
->i_mutex
);
4063 trace_ext4_fallocate_exit(inode
, offset
, max_blocks
,
4064 ret
> 0 ? ret2
: ret
);
4065 return ret
> 0 ? ret2
: ret
;
4069 * This function convert a range of blocks to written extents
4070 * The caller of this function will pass the start offset and the size.
4071 * all unwritten extents within this range will be converted to
4074 * This function is called from the direct IO end io call back
4075 * function, to convert the fallocated extents after IO is completed.
4076 * Returns 0 on success.
4078 int ext4_convert_unwritten_extents(struct inode
*inode
, loff_t offset
,
4082 unsigned int max_blocks
;
4085 struct ext4_map_blocks map
;
4086 unsigned int credits
, blkbits
= inode
->i_blkbits
;
4088 map
.m_lblk
= offset
>> blkbits
;
4090 * We can't just convert len to max_blocks because
4091 * If blocksize = 4096 offset = 3072 and len = 2048
4093 max_blocks
= ((EXT4_BLOCK_ALIGN(len
+ offset
, blkbits
) >> blkbits
) -
4096 * credits to insert 1 extent into extent tree
4098 credits
= ext4_chunk_trans_blocks(inode
, max_blocks
);
4099 while (ret
>= 0 && ret
< max_blocks
) {
4101 map
.m_len
= (max_blocks
-= ret
);
4102 handle
= ext4_journal_start(inode
, credits
);
4103 if (IS_ERR(handle
)) {
4104 ret
= PTR_ERR(handle
);
4107 ret
= ext4_map_blocks(handle
, inode
, &map
,
4108 EXT4_GET_BLOCKS_IO_CONVERT_EXT
);
4111 printk(KERN_ERR
"%s: ext4_ext_map_blocks "
4112 "returned error inode#%lu, block=%u, "
4113 "max_blocks=%u", __func__
,
4114 inode
->i_ino
, map
.m_lblk
, map
.m_len
);
4116 ext4_mark_inode_dirty(handle
, inode
);
4117 ret2
= ext4_journal_stop(handle
);
4118 if (ret
<= 0 || ret2
)
4121 return ret
> 0 ? ret2
: ret
;
4125 * Callback function called for each extent to gather FIEMAP information.
4127 static int ext4_ext_fiemap_cb(struct inode
*inode
, ext4_lblk_t next
,
4128 struct ext4_ext_cache
*newex
, struct ext4_extent
*ex
,
4136 struct fiemap_extent_info
*fieinfo
= data
;
4137 unsigned char blksize_bits
;
4139 blksize_bits
= inode
->i_sb
->s_blocksize_bits
;
4140 logical
= (__u64
)newex
->ec_block
<< blksize_bits
;
4142 if (newex
->ec_start
== 0) {
4144 * No extent in extent-tree contains block @newex->ec_start,
4145 * then the block may stay in 1)a hole or 2)delayed-extent.
4147 * Holes or delayed-extents are processed as follows.
4148 * 1. lookup dirty pages with specified range in pagecache.
4149 * If no page is got, then there is no delayed-extent and
4150 * return with EXT_CONTINUE.
4151 * 2. find the 1st mapped buffer,
4152 * 3. check if the mapped buffer is both in the request range
4153 * and a delayed buffer. If not, there is no delayed-extent,
4155 * 4. a delayed-extent is found, the extent will be collected.
4157 ext4_lblk_t end
= 0;
4158 pgoff_t last_offset
;
4161 pgoff_t start_index
= 0;
4162 struct page
**pages
= NULL
;
4163 struct buffer_head
*bh
= NULL
;
4164 struct buffer_head
*head
= NULL
;
4165 unsigned int nr_pages
= PAGE_SIZE
/ sizeof(struct page
*);
4167 pages
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
4171 offset
= logical
>> PAGE_SHIFT
;
4173 last_offset
= offset
;
4175 ret
= find_get_pages_tag(inode
->i_mapping
, &offset
,
4176 PAGECACHE_TAG_DIRTY
, nr_pages
, pages
);
4178 if (!(flags
& FIEMAP_EXTENT_DELALLOC
)) {
4179 /* First time, try to find a mapped buffer. */
4182 for (index
= 0; index
< ret
; index
++)
4183 page_cache_release(pages
[index
]);
4186 return EXT_CONTINUE
;
4191 /* Try to find the 1st mapped buffer. */
4192 end
= ((__u64
)pages
[index
]->index
<< PAGE_SHIFT
) >>
4194 if (!page_has_buffers(pages
[index
]))
4196 head
= page_buffers(pages
[index
]);
4203 if (end
>= newex
->ec_block
+
4205 /* The buffer is out of
4206 * the request range.
4210 if (buffer_mapped(bh
) &&
4211 end
>= newex
->ec_block
) {
4212 start_index
= index
- 1;
4213 /* get the 1st mapped buffer. */
4214 goto found_mapped_buffer
;
4217 bh
= bh
->b_this_page
;
4219 } while (bh
!= head
);
4221 /* No mapped buffer in the range found in this page,
4222 * We need to look up next page.
4225 /* There is no page left, but we need to limit
4228 newex
->ec_len
= end
- newex
->ec_block
;
4233 /*Find contiguous delayed buffers. */
4234 if (ret
> 0 && pages
[0]->index
== last_offset
)
4235 head
= page_buffers(pages
[0]);
4241 found_mapped_buffer
:
4242 if (bh
!= NULL
&& buffer_delay(bh
)) {
4243 /* 1st or contiguous delayed buffer found. */
4244 if (!(flags
& FIEMAP_EXTENT_DELALLOC
)) {
4246 * 1st delayed buffer found, record
4247 * the start of extent.
4249 flags
|= FIEMAP_EXTENT_DELALLOC
;
4250 newex
->ec_block
= end
;
4251 logical
= (__u64
)end
<< blksize_bits
;
4253 /* Find contiguous delayed buffers. */
4255 if (!buffer_delay(bh
))
4256 goto found_delayed_extent
;
4257 bh
= bh
->b_this_page
;
4259 } while (bh
!= head
);
4261 for (; index
< ret
; index
++) {
4262 if (!page_has_buffers(pages
[index
])) {
4266 head
= page_buffers(pages
[index
]);
4272 if (pages
[index
]->index
!=
4273 pages
[start_index
]->index
+ index
4275 /* Blocks are not contiguous. */
4281 if (!buffer_delay(bh
))
4282 /* Delayed-extent ends. */
4283 goto found_delayed_extent
;
4284 bh
= bh
->b_this_page
;
4286 } while (bh
!= head
);
4288 } else if (!(flags
& FIEMAP_EXTENT_DELALLOC
))
4292 found_delayed_extent
:
4293 newex
->ec_len
= min(end
- newex
->ec_block
,
4294 (ext4_lblk_t
)EXT_INIT_MAX_LEN
);
4295 if (ret
== nr_pages
&& bh
!= NULL
&&
4296 newex
->ec_len
< EXT_INIT_MAX_LEN
&&
4298 /* Have not collected an extent and continue. */
4299 for (index
= 0; index
< ret
; index
++)
4300 page_cache_release(pages
[index
]);
4304 for (index
= 0; index
< ret
; index
++)
4305 page_cache_release(pages
[index
]);
4309 physical
= (__u64
)newex
->ec_start
<< blksize_bits
;
4310 length
= (__u64
)newex
->ec_len
<< blksize_bits
;
4312 if (ex
&& ext4_ext_is_uninitialized(ex
))
4313 flags
|= FIEMAP_EXTENT_UNWRITTEN
;
4315 if (next
== EXT_MAX_BLOCKS
)
4316 flags
|= FIEMAP_EXTENT_LAST
;
4318 ret
= fiemap_fill_next_extent(fieinfo
, logical
, physical
,
4324 return EXT_CONTINUE
;
4326 /* fiemap flags we can handle specified here */
4327 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4329 static int ext4_xattr_fiemap(struct inode
*inode
,
4330 struct fiemap_extent_info
*fieinfo
)
4334 __u32 flags
= FIEMAP_EXTENT_LAST
;
4335 int blockbits
= inode
->i_sb
->s_blocksize_bits
;
4339 if (ext4_test_inode_state(inode
, EXT4_STATE_XATTR
)) {
4340 struct ext4_iloc iloc
;
4341 int offset
; /* offset of xattr in inode */
4343 error
= ext4_get_inode_loc(inode
, &iloc
);
4346 physical
= iloc
.bh
->b_blocknr
<< blockbits
;
4347 offset
= EXT4_GOOD_OLD_INODE_SIZE
+
4348 EXT4_I(inode
)->i_extra_isize
;
4350 length
= EXT4_SB(inode
->i_sb
)->s_inode_size
- offset
;
4351 flags
|= FIEMAP_EXTENT_DATA_INLINE
;
4353 } else { /* external block */
4354 physical
= EXT4_I(inode
)->i_file_acl
<< blockbits
;
4355 length
= inode
->i_sb
->s_blocksize
;
4359 error
= fiemap_fill_next_extent(fieinfo
, 0, physical
,
4361 return (error
< 0 ? error
: 0);
4365 * ext4_ext_punch_hole
4367 * Punches a hole of "length" bytes in a file starting
4370 * @inode: The inode of the file to punch a hole in
4371 * @offset: The starting byte offset of the hole
4372 * @length: The length of the hole
4374 * Returns the number of blocks removed or negative on err
4376 int ext4_ext_punch_hole(struct file
*file
, loff_t offset
, loff_t length
)
4378 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
4379 struct super_block
*sb
= inode
->i_sb
;
4380 struct ext4_ext_cache cache_ex
;
4381 ext4_lblk_t first_block
, last_block
, num_blocks
, iblock
, max_blocks
;
4382 struct address_space
*mapping
= inode
->i_mapping
;
4383 struct ext4_map_blocks map
;
4385 loff_t first_page
, last_page
, page_len
;
4386 loff_t first_page_offset
, last_page_offset
;
4387 int ret
, credits
, blocks_released
, err
= 0;
4389 /* No need to punch hole beyond i_size */
4390 if (offset
>= inode
->i_size
)
4394 * If the hole extends beyond i_size, set the hole
4395 * to end after the page that contains i_size
4397 if (offset
+ length
> inode
->i_size
) {
4398 length
= inode
->i_size
+
4399 PAGE_CACHE_SIZE
- (inode
->i_size
& (PAGE_CACHE_SIZE
- 1)) -
4403 first_block
= (offset
+ sb
->s_blocksize
- 1) >>
4404 EXT4_BLOCK_SIZE_BITS(sb
);
4405 last_block
= (offset
+ length
) >> EXT4_BLOCK_SIZE_BITS(sb
);
4407 first_page
= (offset
+ PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
;
4408 last_page
= (offset
+ length
) >> PAGE_CACHE_SHIFT
;
4410 first_page_offset
= first_page
<< PAGE_CACHE_SHIFT
;
4411 last_page_offset
= last_page
<< PAGE_CACHE_SHIFT
;
4414 * Write out all dirty pages to avoid race conditions
4415 * Then release them.
4417 if (mapping
->nrpages
&& mapping_tagged(mapping
, PAGECACHE_TAG_DIRTY
)) {
4418 err
= filemap_write_and_wait_range(mapping
,
4419 offset
, offset
+ length
- 1);
4425 /* Now release the pages */
4426 if (last_page_offset
> first_page_offset
) {
4427 truncate_inode_pages_range(mapping
, first_page_offset
,
4428 last_page_offset
-1);
4431 /* finish any pending end_io work */
4432 ext4_flush_completed_IO(inode
);
4434 credits
= ext4_writepage_trans_blocks(inode
);
4435 handle
= ext4_journal_start(inode
, credits
);
4437 return PTR_ERR(handle
);
4439 err
= ext4_orphan_add(handle
, inode
);
4444 * Now we need to zero out the non-page-aligned data in the
4445 * pages at the start and tail of the hole, and unmap the buffer
4446 * heads for the block aligned regions of the page that were
4447 * completely zeroed.
4449 if (first_page
> last_page
) {
4451 * If the file space being truncated is contained within a page
4452 * just zero out and unmap the middle of that page
4454 err
= ext4_discard_partial_page_buffers(handle
,
4455 mapping
, offset
, length
, 0);
4461 * zero out and unmap the partial page that contains
4462 * the start of the hole
4464 page_len
= first_page_offset
- offset
;
4466 err
= ext4_discard_partial_page_buffers(handle
, mapping
,
4467 offset
, page_len
, 0);
4473 * zero out and unmap the partial page that contains
4474 * the end of the hole
4476 page_len
= offset
+ length
- last_page_offset
;
4478 err
= ext4_discard_partial_page_buffers(handle
, mapping
,
4479 last_page_offset
, page_len
, 0);
4487 * If i_size is contained in the last page, we need to
4488 * unmap and zero the partial page after i_size
4490 if (inode
->i_size
>> PAGE_CACHE_SHIFT
== last_page
&&
4491 inode
->i_size
% PAGE_CACHE_SIZE
!= 0) {
4493 page_len
= PAGE_CACHE_SIZE
-
4494 (inode
->i_size
& (PAGE_CACHE_SIZE
- 1));
4497 err
= ext4_discard_partial_page_buffers(handle
,
4498 mapping
, inode
->i_size
, page_len
, 0);
4505 /* If there are no blocks to remove, return now */
4506 if (first_block
>= last_block
)
4509 down_write(&EXT4_I(inode
)->i_data_sem
);
4510 ext4_ext_invalidate_cache(inode
);
4511 ext4_discard_preallocations(inode
);
4514 * Loop over all the blocks and identify blocks
4515 * that need to be punched out
4517 iblock
= first_block
;
4518 blocks_released
= 0;
4519 while (iblock
< last_block
) {
4520 max_blocks
= last_block
- iblock
;
4522 memset(&map
, 0, sizeof(map
));
4523 map
.m_lblk
= iblock
;
4524 map
.m_len
= max_blocks
;
4525 ret
= ext4_ext_map_blocks(handle
, inode
, &map
,
4526 EXT4_GET_BLOCKS_PUNCH_OUT_EXT
);
4529 blocks_released
+= ret
;
4531 } else if (ret
== 0) {
4533 * If map blocks could not find the block,
4534 * then it is in a hole. If the hole was
4535 * not already cached, then map blocks should
4536 * put it in the cache. So we can get the hole
4539 memset(&cache_ex
, 0, sizeof(cache_ex
));
4540 if ((ext4_ext_check_cache(inode
, iblock
, &cache_ex
)) &&
4541 !cache_ex
.ec_start
) {
4543 /* The hole is cached */
4544 num_blocks
= cache_ex
.ec_block
+
4545 cache_ex
.ec_len
- iblock
;
4548 /* The block could not be identified */
4553 /* Map blocks error */
4558 if (num_blocks
== 0) {
4559 /* This condition should never happen */
4560 ext_debug("Block lookup failed");
4565 iblock
+= num_blocks
;
4568 if (blocks_released
> 0) {
4569 ext4_ext_invalidate_cache(inode
);
4570 ext4_discard_preallocations(inode
);
4574 ext4_handle_sync(handle
);
4576 up_write(&EXT4_I(inode
)->i_data_sem
);
4579 ext4_orphan_del(handle
, inode
);
4580 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
4581 ext4_mark_inode_dirty(handle
, inode
);
4582 ext4_journal_stop(handle
);
4585 int ext4_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
4586 __u64 start
, __u64 len
)
4588 ext4_lblk_t start_blk
;
4591 /* fallback to generic here if not in extents fmt */
4592 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
4593 return generic_block_fiemap(inode
, fieinfo
, start
, len
,
4596 if (fiemap_check_flags(fieinfo
, EXT4_FIEMAP_FLAGS
))
4599 if (fieinfo
->fi_flags
& FIEMAP_FLAG_XATTR
) {
4600 error
= ext4_xattr_fiemap(inode
, fieinfo
);
4602 ext4_lblk_t len_blks
;
4605 start_blk
= start
>> inode
->i_sb
->s_blocksize_bits
;
4606 last_blk
= (start
+ len
- 1) >> inode
->i_sb
->s_blocksize_bits
;
4607 if (last_blk
>= EXT_MAX_BLOCKS
)
4608 last_blk
= EXT_MAX_BLOCKS
-1;
4609 len_blks
= ((ext4_lblk_t
) last_blk
) - start_blk
+ 1;
4612 * Walk the extent tree gathering extent information.
4613 * ext4_ext_fiemap_cb will push extents back to user.
4615 error
= ext4_ext_walk_space(inode
, start_blk
, len_blks
,
4616 ext4_ext_fiemap_cb
, fieinfo
);