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 "ext4_jbd2.h"
44 #include "ext4_extents.h"
49 * combine low and high parts of physical block number into ext4_fsblk_t
51 static ext4_fsblk_t
ext_pblock(struct ext4_extent
*ex
)
55 block
= le32_to_cpu(ex
->ee_start_lo
);
56 block
|= ((ext4_fsblk_t
) le16_to_cpu(ex
->ee_start_hi
) << 31) << 1;
62 * combine low and high parts of a leaf physical block number into ext4_fsblk_t
64 ext4_fsblk_t
idx_pblock(struct ext4_extent_idx
*ix
)
68 block
= le32_to_cpu(ix
->ei_leaf_lo
);
69 block
|= ((ext4_fsblk_t
) le16_to_cpu(ix
->ei_leaf_hi
) << 31) << 1;
74 * ext4_ext_store_pblock:
75 * stores a large physical block number into an extent struct,
76 * breaking it into parts
78 void ext4_ext_store_pblock(struct ext4_extent
*ex
, ext4_fsblk_t pb
)
80 ex
->ee_start_lo
= cpu_to_le32((unsigned long) (pb
& 0xffffffff));
81 ex
->ee_start_hi
= cpu_to_le16((unsigned long) ((pb
>> 31) >> 1) & 0xffff);
85 * ext4_idx_store_pblock:
86 * stores a large physical block number into an index struct,
87 * breaking it into parts
89 static void ext4_idx_store_pblock(struct ext4_extent_idx
*ix
, ext4_fsblk_t pb
)
91 ix
->ei_leaf_lo
= cpu_to_le32((unsigned long) (pb
& 0xffffffff));
92 ix
->ei_leaf_hi
= cpu_to_le16((unsigned long) ((pb
>> 31) >> 1) & 0xffff);
95 static handle_t
*ext4_ext_journal_restart(handle_t
*handle
, int needed
)
99 if (handle
->h_buffer_credits
> needed
)
101 if (!ext4_journal_extend(handle
, needed
))
103 err
= ext4_journal_restart(handle
, needed
);
113 static int ext4_ext_get_access(handle_t
*handle
, struct inode
*inode
,
114 struct ext4_ext_path
*path
)
117 /* path points to block */
118 return ext4_journal_get_write_access(handle
, path
->p_bh
);
120 /* path points to leaf/index in inode body */
121 /* we use in-core data, no need to protect them */
131 static int ext4_ext_dirty(handle_t
*handle
, struct inode
*inode
,
132 struct ext4_ext_path
*path
)
136 /* path points to block */
137 err
= ext4_journal_dirty_metadata(handle
, path
->p_bh
);
139 /* path points to leaf/index in inode body */
140 err
= ext4_mark_inode_dirty(handle
, inode
);
145 static ext4_fsblk_t
ext4_ext_find_goal(struct inode
*inode
,
146 struct ext4_ext_path
*path
,
149 struct ext4_inode_info
*ei
= EXT4_I(inode
);
150 ext4_fsblk_t bg_start
;
151 ext4_fsblk_t last_block
;
152 ext4_grpblk_t colour
;
156 struct ext4_extent
*ex
;
157 depth
= path
->p_depth
;
159 /* try to predict block placement */
160 ex
= path
[depth
].p_ext
;
162 return ext_pblock(ex
)+(block
-le32_to_cpu(ex
->ee_block
));
164 /* it looks like index is empty;
165 * try to find starting block from index itself */
166 if (path
[depth
].p_bh
)
167 return path
[depth
].p_bh
->b_blocknr
;
170 /* OK. use inode's group */
171 bg_start
= (ei
->i_block_group
* EXT4_BLOCKS_PER_GROUP(inode
->i_sb
)) +
172 le32_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_first_data_block
);
173 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
175 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
176 colour
= (current
->pid
% 16) *
177 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
179 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
180 return bg_start
+ colour
+ block
;
184 ext4_ext_new_block(handle_t
*handle
, struct inode
*inode
,
185 struct ext4_ext_path
*path
,
186 struct ext4_extent
*ex
, int *err
)
188 ext4_fsblk_t goal
, newblock
;
190 goal
= ext4_ext_find_goal(inode
, path
, le32_to_cpu(ex
->ee_block
));
191 newblock
= ext4_new_block(handle
, inode
, goal
, err
);
195 static int ext4_ext_space_block(struct inode
*inode
)
199 size
= (inode
->i_sb
->s_blocksize
- sizeof(struct ext4_extent_header
))
200 / sizeof(struct ext4_extent
);
201 #ifdef AGGRESSIVE_TEST
208 static int ext4_ext_space_block_idx(struct inode
*inode
)
212 size
= (inode
->i_sb
->s_blocksize
- sizeof(struct ext4_extent_header
))
213 / sizeof(struct ext4_extent_idx
);
214 #ifdef AGGRESSIVE_TEST
221 static int ext4_ext_space_root(struct inode
*inode
)
225 size
= sizeof(EXT4_I(inode
)->i_data
);
226 size
-= sizeof(struct ext4_extent_header
);
227 size
/= sizeof(struct ext4_extent
);
228 #ifdef AGGRESSIVE_TEST
235 static int ext4_ext_space_root_idx(struct inode
*inode
)
239 size
= sizeof(EXT4_I(inode
)->i_data
);
240 size
-= sizeof(struct ext4_extent_header
);
241 size
/= sizeof(struct ext4_extent_idx
);
242 #ifdef AGGRESSIVE_TEST
250 ext4_ext_max_entries(struct inode
*inode
, int depth
)
254 if (depth
== ext_depth(inode
)) {
256 max
= ext4_ext_space_root(inode
);
258 max
= ext4_ext_space_root_idx(inode
);
261 max
= ext4_ext_space_block(inode
);
263 max
= ext4_ext_space_block_idx(inode
);
269 static int __ext4_ext_check_header(const char *function
, struct inode
*inode
,
270 struct ext4_extent_header
*eh
,
273 const char *error_msg
;
276 if (unlikely(eh
->eh_magic
!= EXT4_EXT_MAGIC
)) {
277 error_msg
= "invalid magic";
280 if (unlikely(le16_to_cpu(eh
->eh_depth
) != depth
)) {
281 error_msg
= "unexpected eh_depth";
284 if (unlikely(eh
->eh_max
== 0)) {
285 error_msg
= "invalid eh_max";
288 max
= ext4_ext_max_entries(inode
, depth
);
289 if (unlikely(le16_to_cpu(eh
->eh_max
) > max
)) {
290 error_msg
= "too large eh_max";
293 if (unlikely(le16_to_cpu(eh
->eh_entries
) > le16_to_cpu(eh
->eh_max
))) {
294 error_msg
= "invalid eh_entries";
300 ext4_error(inode
->i_sb
, function
,
301 "bad header in inode #%lu: %s - magic %x, "
302 "entries %u, max %u(%u), depth %u(%u)",
303 inode
->i_ino
, error_msg
, le16_to_cpu(eh
->eh_magic
),
304 le16_to_cpu(eh
->eh_entries
), le16_to_cpu(eh
->eh_max
),
305 max
, le16_to_cpu(eh
->eh_depth
), depth
);
310 #define ext4_ext_check_header(inode, eh, depth) \
311 __ext4_ext_check_header(__func__, inode, eh, depth)
314 static void ext4_ext_show_path(struct inode
*inode
, struct ext4_ext_path
*path
)
316 int k
, l
= path
->p_depth
;
319 for (k
= 0; k
<= l
; k
++, path
++) {
321 ext_debug(" %d->%llu", le32_to_cpu(path
->p_idx
->ei_block
),
322 idx_pblock(path
->p_idx
));
323 } else if (path
->p_ext
) {
324 ext_debug(" %d:%d:%llu ",
325 le32_to_cpu(path
->p_ext
->ee_block
),
326 ext4_ext_get_actual_len(path
->p_ext
),
327 ext_pblock(path
->p_ext
));
334 static void ext4_ext_show_leaf(struct inode
*inode
, struct ext4_ext_path
*path
)
336 int depth
= ext_depth(inode
);
337 struct ext4_extent_header
*eh
;
338 struct ext4_extent
*ex
;
344 eh
= path
[depth
].p_hdr
;
345 ex
= EXT_FIRST_EXTENT(eh
);
347 for (i
= 0; i
< le16_to_cpu(eh
->eh_entries
); i
++, ex
++) {
348 ext_debug("%d:%d:%llu ", le32_to_cpu(ex
->ee_block
),
349 ext4_ext_get_actual_len(ex
), ext_pblock(ex
));
354 #define ext4_ext_show_path(inode,path)
355 #define ext4_ext_show_leaf(inode,path)
358 void ext4_ext_drop_refs(struct ext4_ext_path
*path
)
360 int depth
= path
->p_depth
;
363 for (i
= 0; i
<= depth
; i
++, path
++)
371 * ext4_ext_binsearch_idx:
372 * binary search for the closest index of the given block
373 * the header must be checked before calling this
376 ext4_ext_binsearch_idx(struct inode
*inode
,
377 struct ext4_ext_path
*path
, ext4_lblk_t block
)
379 struct ext4_extent_header
*eh
= path
->p_hdr
;
380 struct ext4_extent_idx
*r
, *l
, *m
;
383 ext_debug("binsearch for %u(idx): ", block
);
385 l
= EXT_FIRST_INDEX(eh
) + 1;
386 r
= EXT_LAST_INDEX(eh
);
389 if (block
< le32_to_cpu(m
->ei_block
))
393 ext_debug("%p(%u):%p(%u):%p(%u) ", l
, le32_to_cpu(l
->ei_block
),
394 m
, le32_to_cpu(m
->ei_block
),
395 r
, le32_to_cpu(r
->ei_block
));
399 ext_debug(" -> %d->%lld ", le32_to_cpu(path
->p_idx
->ei_block
),
400 idx_pblock(path
->p_idx
));
402 #ifdef CHECK_BINSEARCH
404 struct ext4_extent_idx
*chix
, *ix
;
407 chix
= ix
= EXT_FIRST_INDEX(eh
);
408 for (k
= 0; k
< le16_to_cpu(eh
->eh_entries
); k
++, ix
++) {
410 le32_to_cpu(ix
->ei_block
) <= le32_to_cpu(ix
[-1].ei_block
)) {
411 printk("k=%d, ix=0x%p, first=0x%p\n", k
,
412 ix
, EXT_FIRST_INDEX(eh
));
414 le32_to_cpu(ix
->ei_block
),
415 le32_to_cpu(ix
[-1].ei_block
));
417 BUG_ON(k
&& le32_to_cpu(ix
->ei_block
)
418 <= le32_to_cpu(ix
[-1].ei_block
));
419 if (block
< le32_to_cpu(ix
->ei_block
))
423 BUG_ON(chix
!= path
->p_idx
);
430 * ext4_ext_binsearch:
431 * binary search for closest extent of the given block
432 * the header must be checked before calling this
435 ext4_ext_binsearch(struct inode
*inode
,
436 struct ext4_ext_path
*path
, ext4_lblk_t block
)
438 struct ext4_extent_header
*eh
= path
->p_hdr
;
439 struct ext4_extent
*r
, *l
, *m
;
441 if (eh
->eh_entries
== 0) {
443 * this leaf is empty:
444 * we get such a leaf in split/add case
449 ext_debug("binsearch for %u: ", block
);
451 l
= EXT_FIRST_EXTENT(eh
) + 1;
452 r
= EXT_LAST_EXTENT(eh
);
456 if (block
< le32_to_cpu(m
->ee_block
))
460 ext_debug("%p(%u):%p(%u):%p(%u) ", l
, le32_to_cpu(l
->ee_block
),
461 m
, le32_to_cpu(m
->ee_block
),
462 r
, le32_to_cpu(r
->ee_block
));
466 ext_debug(" -> %d:%llu:%d ",
467 le32_to_cpu(path
->p_ext
->ee_block
),
468 ext_pblock(path
->p_ext
),
469 ext4_ext_get_actual_len(path
->p_ext
));
471 #ifdef CHECK_BINSEARCH
473 struct ext4_extent
*chex
, *ex
;
476 chex
= ex
= EXT_FIRST_EXTENT(eh
);
477 for (k
= 0; k
< le16_to_cpu(eh
->eh_entries
); k
++, ex
++) {
478 BUG_ON(k
&& le32_to_cpu(ex
->ee_block
)
479 <= le32_to_cpu(ex
[-1].ee_block
));
480 if (block
< le32_to_cpu(ex
->ee_block
))
484 BUG_ON(chex
!= path
->p_ext
);
490 int ext4_ext_tree_init(handle_t
*handle
, struct inode
*inode
)
492 struct ext4_extent_header
*eh
;
494 eh
= ext_inode_hdr(inode
);
497 eh
->eh_magic
= EXT4_EXT_MAGIC
;
498 eh
->eh_max
= cpu_to_le16(ext4_ext_space_root(inode
));
499 ext4_mark_inode_dirty(handle
, inode
);
500 ext4_ext_invalidate_cache(inode
);
504 struct ext4_ext_path
*
505 ext4_ext_find_extent(struct inode
*inode
, ext4_lblk_t block
,
506 struct ext4_ext_path
*path
)
508 struct ext4_extent_header
*eh
;
509 struct buffer_head
*bh
;
510 short int depth
, i
, ppos
= 0, alloc
= 0;
512 eh
= ext_inode_hdr(inode
);
513 depth
= ext_depth(inode
);
514 if (ext4_ext_check_header(inode
, eh
, depth
))
515 return ERR_PTR(-EIO
);
518 /* account possible depth increase */
520 path
= kzalloc(sizeof(struct ext4_ext_path
) * (depth
+ 2),
523 return ERR_PTR(-ENOMEM
);
530 /* walk through the tree */
532 ext_debug("depth %d: num %d, max %d\n",
533 ppos
, le16_to_cpu(eh
->eh_entries
), le16_to_cpu(eh
->eh_max
));
535 ext4_ext_binsearch_idx(inode
, path
+ ppos
, block
);
536 path
[ppos
].p_block
= idx_pblock(path
[ppos
].p_idx
);
537 path
[ppos
].p_depth
= i
;
538 path
[ppos
].p_ext
= NULL
;
540 bh
= sb_bread(inode
->i_sb
, path
[ppos
].p_block
);
544 eh
= ext_block_hdr(bh
);
546 BUG_ON(ppos
> depth
);
547 path
[ppos
].p_bh
= bh
;
548 path
[ppos
].p_hdr
= eh
;
551 if (ext4_ext_check_header(inode
, eh
, i
))
555 path
[ppos
].p_depth
= i
;
556 path
[ppos
].p_ext
= NULL
;
557 path
[ppos
].p_idx
= NULL
;
560 ext4_ext_binsearch(inode
, path
+ ppos
, block
);
561 /* if not an empty leaf */
562 if (path
[ppos
].p_ext
)
563 path
[ppos
].p_block
= ext_pblock(path
[ppos
].p_ext
);
565 ext4_ext_show_path(inode
, path
);
570 ext4_ext_drop_refs(path
);
573 return ERR_PTR(-EIO
);
577 * ext4_ext_insert_index:
578 * insert new index [@logical;@ptr] into the block at @curp;
579 * check where to insert: before @curp or after @curp
581 static int ext4_ext_insert_index(handle_t
*handle
, struct inode
*inode
,
582 struct ext4_ext_path
*curp
,
583 int logical
, ext4_fsblk_t ptr
)
585 struct ext4_extent_idx
*ix
;
588 err
= ext4_ext_get_access(handle
, inode
, curp
);
592 BUG_ON(logical
== le32_to_cpu(curp
->p_idx
->ei_block
));
593 len
= EXT_MAX_INDEX(curp
->p_hdr
) - curp
->p_idx
;
594 if (logical
> le32_to_cpu(curp
->p_idx
->ei_block
)) {
596 if (curp
->p_idx
!= EXT_LAST_INDEX(curp
->p_hdr
)) {
597 len
= (len
- 1) * sizeof(struct ext4_extent_idx
);
598 len
= len
< 0 ? 0 : len
;
599 ext_debug("insert new index %d after: %llu. "
600 "move %d from 0x%p to 0x%p\n",
602 (curp
->p_idx
+ 1), (curp
->p_idx
+ 2));
603 memmove(curp
->p_idx
+ 2, curp
->p_idx
+ 1, len
);
605 ix
= curp
->p_idx
+ 1;
608 len
= len
* sizeof(struct ext4_extent_idx
);
609 len
= len
< 0 ? 0 : len
;
610 ext_debug("insert new index %d before: %llu. "
611 "move %d from 0x%p to 0x%p\n",
613 curp
->p_idx
, (curp
->p_idx
+ 1));
614 memmove(curp
->p_idx
+ 1, curp
->p_idx
, len
);
618 ix
->ei_block
= cpu_to_le32(logical
);
619 ext4_idx_store_pblock(ix
, ptr
);
620 le16_add_cpu(&curp
->p_hdr
->eh_entries
, 1);
622 BUG_ON(le16_to_cpu(curp
->p_hdr
->eh_entries
)
623 > le16_to_cpu(curp
->p_hdr
->eh_max
));
624 BUG_ON(ix
> EXT_LAST_INDEX(curp
->p_hdr
));
626 err
= ext4_ext_dirty(handle
, inode
, curp
);
627 ext4_std_error(inode
->i_sb
, err
);
634 * inserts new subtree into the path, using free index entry
636 * - allocates all needed blocks (new leaf and all intermediate index blocks)
637 * - makes decision where to split
638 * - moves remaining extents and index entries (right to the split point)
639 * into the newly allocated blocks
640 * - initializes subtree
642 static int ext4_ext_split(handle_t
*handle
, struct inode
*inode
,
643 struct ext4_ext_path
*path
,
644 struct ext4_extent
*newext
, int at
)
646 struct buffer_head
*bh
= NULL
;
647 int depth
= ext_depth(inode
);
648 struct ext4_extent_header
*neh
;
649 struct ext4_extent_idx
*fidx
;
650 struct ext4_extent
*ex
;
652 ext4_fsblk_t newblock
, oldblock
;
654 ext4_fsblk_t
*ablocks
= NULL
; /* array of allocated blocks */
657 /* make decision: where to split? */
658 /* FIXME: now decision is simplest: at current extent */
660 /* if current leaf will be split, then we should use
661 * border from split point */
662 BUG_ON(path
[depth
].p_ext
> EXT_MAX_EXTENT(path
[depth
].p_hdr
));
663 if (path
[depth
].p_ext
!= EXT_MAX_EXTENT(path
[depth
].p_hdr
)) {
664 border
= path
[depth
].p_ext
[1].ee_block
;
665 ext_debug("leaf will be split."
666 " next leaf starts at %d\n",
667 le32_to_cpu(border
));
669 border
= newext
->ee_block
;
670 ext_debug("leaf will be added."
671 " next leaf starts at %d\n",
672 le32_to_cpu(border
));
676 * If error occurs, then we break processing
677 * and mark filesystem read-only. index won't
678 * be inserted and tree will be in consistent
679 * state. Next mount will repair buffers too.
683 * Get array to track all allocated blocks.
684 * We need this to handle errors and free blocks
687 ablocks
= kzalloc(sizeof(ext4_fsblk_t
) * depth
, GFP_NOFS
);
691 /* allocate all needed blocks */
692 ext_debug("allocate %d blocks for indexes/leaf\n", depth
- at
);
693 for (a
= 0; a
< depth
- at
; a
++) {
694 newblock
= ext4_ext_new_block(handle
, inode
, path
, newext
, &err
);
697 ablocks
[a
] = newblock
;
700 /* initialize new leaf */
701 newblock
= ablocks
[--a
];
702 BUG_ON(newblock
== 0);
703 bh
= sb_getblk(inode
->i_sb
, newblock
);
710 err
= ext4_journal_get_create_access(handle
, bh
);
714 neh
= ext_block_hdr(bh
);
716 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block(inode
));
717 neh
->eh_magic
= EXT4_EXT_MAGIC
;
719 ex
= EXT_FIRST_EXTENT(neh
);
721 /* move remainder of path[depth] to the new leaf */
722 BUG_ON(path
[depth
].p_hdr
->eh_entries
!= path
[depth
].p_hdr
->eh_max
);
723 /* start copy from next extent */
724 /* TODO: we could do it by single memmove */
727 while (path
[depth
].p_ext
<=
728 EXT_MAX_EXTENT(path
[depth
].p_hdr
)) {
729 ext_debug("move %d:%llu:%d in new leaf %llu\n",
730 le32_to_cpu(path
[depth
].p_ext
->ee_block
),
731 ext_pblock(path
[depth
].p_ext
),
732 ext4_ext_get_actual_len(path
[depth
].p_ext
),
734 /*memmove(ex++, path[depth].p_ext++,
735 sizeof(struct ext4_extent));
741 memmove(ex
, path
[depth
].p_ext
-m
, sizeof(struct ext4_extent
)*m
);
742 le16_add_cpu(&neh
->eh_entries
, m
);
745 set_buffer_uptodate(bh
);
748 err
= ext4_journal_dirty_metadata(handle
, bh
);
754 /* correct old leaf */
756 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
759 le16_add_cpu(&path
[depth
].p_hdr
->eh_entries
, -m
);
760 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
766 /* create intermediate indexes */
770 ext_debug("create %d intermediate indices\n", k
);
771 /* insert new index into current index block */
772 /* current depth stored in i var */
776 newblock
= ablocks
[--a
];
777 bh
= sb_getblk(inode
->i_sb
, newblock
);
784 err
= ext4_journal_get_create_access(handle
, bh
);
788 neh
= ext_block_hdr(bh
);
789 neh
->eh_entries
= cpu_to_le16(1);
790 neh
->eh_magic
= EXT4_EXT_MAGIC
;
791 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block_idx(inode
));
792 neh
->eh_depth
= cpu_to_le16(depth
- i
);
793 fidx
= EXT_FIRST_INDEX(neh
);
794 fidx
->ei_block
= border
;
795 ext4_idx_store_pblock(fidx
, oldblock
);
797 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
798 i
, newblock
, le32_to_cpu(border
), oldblock
);
803 ext_debug("cur 0x%p, last 0x%p\n", path
[i
].p_idx
,
804 EXT_MAX_INDEX(path
[i
].p_hdr
));
805 BUG_ON(EXT_MAX_INDEX(path
[i
].p_hdr
) !=
806 EXT_LAST_INDEX(path
[i
].p_hdr
));
807 while (path
[i
].p_idx
<= EXT_MAX_INDEX(path
[i
].p_hdr
)) {
808 ext_debug("%d: move %d:%llu in new index %llu\n", i
,
809 le32_to_cpu(path
[i
].p_idx
->ei_block
),
810 idx_pblock(path
[i
].p_idx
),
812 /*memmove(++fidx, path[i].p_idx++,
813 sizeof(struct ext4_extent_idx));
815 BUG_ON(neh->eh_entries > neh->eh_max);*/
820 memmove(++fidx
, path
[i
].p_idx
- m
,
821 sizeof(struct ext4_extent_idx
) * m
);
822 le16_add_cpu(&neh
->eh_entries
, m
);
824 set_buffer_uptodate(bh
);
827 err
= ext4_journal_dirty_metadata(handle
, bh
);
833 /* correct old index */
835 err
= ext4_ext_get_access(handle
, inode
, path
+ i
);
838 le16_add_cpu(&path
[i
].p_hdr
->eh_entries
, -m
);
839 err
= ext4_ext_dirty(handle
, inode
, path
+ i
);
847 /* insert new index */
848 err
= ext4_ext_insert_index(handle
, inode
, path
+ at
,
849 le32_to_cpu(border
), newblock
);
853 if (buffer_locked(bh
))
859 /* free all allocated blocks in error case */
860 for (i
= 0; i
< depth
; i
++) {
863 ext4_free_blocks(handle
, inode
, ablocks
[i
], 1, 1);
872 * ext4_ext_grow_indepth:
873 * implements tree growing procedure:
874 * - allocates new block
875 * - moves top-level data (index block or leaf) into the new block
876 * - initializes new top-level, creating index that points to the
879 static int ext4_ext_grow_indepth(handle_t
*handle
, struct inode
*inode
,
880 struct ext4_ext_path
*path
,
881 struct ext4_extent
*newext
)
883 struct ext4_ext_path
*curp
= path
;
884 struct ext4_extent_header
*neh
;
885 struct ext4_extent_idx
*fidx
;
886 struct buffer_head
*bh
;
887 ext4_fsblk_t newblock
;
890 newblock
= ext4_ext_new_block(handle
, inode
, path
, newext
, &err
);
894 bh
= sb_getblk(inode
->i_sb
, newblock
);
897 ext4_std_error(inode
->i_sb
, err
);
902 err
= ext4_journal_get_create_access(handle
, bh
);
908 /* move top-level index/leaf into new block */
909 memmove(bh
->b_data
, curp
->p_hdr
, sizeof(EXT4_I(inode
)->i_data
));
911 /* set size of new block */
912 neh
= ext_block_hdr(bh
);
913 /* old root could have indexes or leaves
914 * so calculate e_max right way */
915 if (ext_depth(inode
))
916 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block_idx(inode
));
918 neh
->eh_max
= cpu_to_le16(ext4_ext_space_block(inode
));
919 neh
->eh_magic
= EXT4_EXT_MAGIC
;
920 set_buffer_uptodate(bh
);
923 err
= ext4_journal_dirty_metadata(handle
, bh
);
927 /* create index in new top-level index: num,max,pointer */
928 err
= ext4_ext_get_access(handle
, inode
, curp
);
932 curp
->p_hdr
->eh_magic
= EXT4_EXT_MAGIC
;
933 curp
->p_hdr
->eh_max
= cpu_to_le16(ext4_ext_space_root_idx(inode
));
934 curp
->p_hdr
->eh_entries
= cpu_to_le16(1);
935 curp
->p_idx
= EXT_FIRST_INDEX(curp
->p_hdr
);
937 if (path
[0].p_hdr
->eh_depth
)
938 curp
->p_idx
->ei_block
=
939 EXT_FIRST_INDEX(path
[0].p_hdr
)->ei_block
;
941 curp
->p_idx
->ei_block
=
942 EXT_FIRST_EXTENT(path
[0].p_hdr
)->ee_block
;
943 ext4_idx_store_pblock(curp
->p_idx
, newblock
);
945 neh
= ext_inode_hdr(inode
);
946 fidx
= EXT_FIRST_INDEX(neh
);
947 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
948 le16_to_cpu(neh
->eh_entries
), le16_to_cpu(neh
->eh_max
),
949 le32_to_cpu(fidx
->ei_block
), idx_pblock(fidx
));
951 neh
->eh_depth
= cpu_to_le16(path
->p_depth
+ 1);
952 err
= ext4_ext_dirty(handle
, inode
, curp
);
960 * ext4_ext_create_new_leaf:
961 * finds empty index and adds new leaf.
962 * if no free index is found, then it requests in-depth growing.
964 static int ext4_ext_create_new_leaf(handle_t
*handle
, struct inode
*inode
,
965 struct ext4_ext_path
*path
,
966 struct ext4_extent
*newext
)
968 struct ext4_ext_path
*curp
;
969 int depth
, i
, err
= 0;
972 i
= depth
= ext_depth(inode
);
974 /* walk up to the tree and look for free index entry */
976 while (i
> 0 && !EXT_HAS_FREE_INDEX(curp
)) {
981 /* we use already allocated block for index block,
982 * so subsequent data blocks should be contiguous */
983 if (EXT_HAS_FREE_INDEX(curp
)) {
984 /* if we found index with free entry, then use that
985 * entry: create all needed subtree and add new leaf */
986 err
= ext4_ext_split(handle
, inode
, path
, newext
, i
);
991 ext4_ext_drop_refs(path
);
992 path
= ext4_ext_find_extent(inode
,
993 (ext4_lblk_t
)le32_to_cpu(newext
->ee_block
),
998 /* tree is full, time to grow in depth */
999 err
= ext4_ext_grow_indepth(handle
, inode
, path
, newext
);
1004 ext4_ext_drop_refs(path
);
1005 path
= ext4_ext_find_extent(inode
,
1006 (ext4_lblk_t
)le32_to_cpu(newext
->ee_block
),
1009 err
= PTR_ERR(path
);
1014 * only first (depth 0 -> 1) produces free space;
1015 * in all other cases we have to split the grown tree
1017 depth
= ext_depth(inode
);
1018 if (path
[depth
].p_hdr
->eh_entries
== path
[depth
].p_hdr
->eh_max
) {
1019 /* now we need to split */
1029 * search the closest allocated block to the left for *logical
1030 * and returns it at @logical + it's physical address at @phys
1031 * if *logical is the smallest allocated block, the function
1032 * returns 0 at @phys
1033 * return value contains 0 (success) or error code
1036 ext4_ext_search_left(struct inode
*inode
, struct ext4_ext_path
*path
,
1037 ext4_lblk_t
*logical
, ext4_fsblk_t
*phys
)
1039 struct ext4_extent_idx
*ix
;
1040 struct ext4_extent
*ex
;
1043 BUG_ON(path
== NULL
);
1044 depth
= path
->p_depth
;
1047 if (depth
== 0 && path
->p_ext
== NULL
)
1050 /* usually extent in the path covers blocks smaller
1051 * then *logical, but it can be that extent is the
1052 * first one in the file */
1054 ex
= path
[depth
].p_ext
;
1055 ee_len
= ext4_ext_get_actual_len(ex
);
1056 if (*logical
< le32_to_cpu(ex
->ee_block
)) {
1057 BUG_ON(EXT_FIRST_EXTENT(path
[depth
].p_hdr
) != ex
);
1058 while (--depth
>= 0) {
1059 ix
= path
[depth
].p_idx
;
1060 BUG_ON(ix
!= EXT_FIRST_INDEX(path
[depth
].p_hdr
));
1065 BUG_ON(*logical
< (le32_to_cpu(ex
->ee_block
) + ee_len
));
1067 *logical
= le32_to_cpu(ex
->ee_block
) + ee_len
- 1;
1068 *phys
= ext_pblock(ex
) + ee_len
- 1;
1073 * search the closest allocated block to the right for *logical
1074 * and returns it at @logical + it's physical address at @phys
1075 * if *logical is the smallest allocated block, the function
1076 * returns 0 at @phys
1077 * return value contains 0 (success) or error code
1080 ext4_ext_search_right(struct inode
*inode
, struct ext4_ext_path
*path
,
1081 ext4_lblk_t
*logical
, ext4_fsblk_t
*phys
)
1083 struct buffer_head
*bh
= NULL
;
1084 struct ext4_extent_header
*eh
;
1085 struct ext4_extent_idx
*ix
;
1086 struct ext4_extent
*ex
;
1090 BUG_ON(path
== NULL
);
1091 depth
= path
->p_depth
;
1094 if (depth
== 0 && path
->p_ext
== NULL
)
1097 /* usually extent in the path covers blocks smaller
1098 * then *logical, but it can be that extent is the
1099 * first one in the file */
1101 ex
= path
[depth
].p_ext
;
1102 ee_len
= ext4_ext_get_actual_len(ex
);
1103 if (*logical
< le32_to_cpu(ex
->ee_block
)) {
1104 BUG_ON(EXT_FIRST_EXTENT(path
[depth
].p_hdr
) != ex
);
1105 while (--depth
>= 0) {
1106 ix
= path
[depth
].p_idx
;
1107 BUG_ON(ix
!= EXT_FIRST_INDEX(path
[depth
].p_hdr
));
1109 *logical
= le32_to_cpu(ex
->ee_block
);
1110 *phys
= ext_pblock(ex
);
1114 BUG_ON(*logical
< (le32_to_cpu(ex
->ee_block
) + ee_len
));
1116 if (ex
!= EXT_LAST_EXTENT(path
[depth
].p_hdr
)) {
1117 /* next allocated block in this leaf */
1119 *logical
= le32_to_cpu(ex
->ee_block
);
1120 *phys
= ext_pblock(ex
);
1124 /* go up and search for index to the right */
1125 while (--depth
>= 0) {
1126 ix
= path
[depth
].p_idx
;
1127 if (ix
!= EXT_LAST_INDEX(path
[depth
].p_hdr
))
1132 /* we've gone up to the root and
1133 * found no index to the right */
1137 /* we've found index to the right, let's
1138 * follow it and find the closest allocated
1139 * block to the right */
1141 block
= idx_pblock(ix
);
1142 while (++depth
< path
->p_depth
) {
1143 bh
= sb_bread(inode
->i_sb
, block
);
1146 eh
= ext_block_hdr(bh
);
1147 if (ext4_ext_check_header(inode
, eh
, depth
)) {
1151 ix
= EXT_FIRST_INDEX(eh
);
1152 block
= idx_pblock(ix
);
1156 bh
= sb_bread(inode
->i_sb
, block
);
1159 eh
= ext_block_hdr(bh
);
1160 if (ext4_ext_check_header(inode
, eh
, path
->p_depth
- depth
)) {
1164 ex
= EXT_FIRST_EXTENT(eh
);
1165 *logical
= le32_to_cpu(ex
->ee_block
);
1166 *phys
= ext_pblock(ex
);
1173 * ext4_ext_next_allocated_block:
1174 * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
1175 * NOTE: it considers block number from index entry as
1176 * allocated block. Thus, index entries have to be consistent
1180 ext4_ext_next_allocated_block(struct ext4_ext_path
*path
)
1184 BUG_ON(path
== NULL
);
1185 depth
= path
->p_depth
;
1187 if (depth
== 0 && path
->p_ext
== NULL
)
1188 return EXT_MAX_BLOCK
;
1190 while (depth
>= 0) {
1191 if (depth
== path
->p_depth
) {
1193 if (path
[depth
].p_ext
!=
1194 EXT_LAST_EXTENT(path
[depth
].p_hdr
))
1195 return le32_to_cpu(path
[depth
].p_ext
[1].ee_block
);
1198 if (path
[depth
].p_idx
!=
1199 EXT_LAST_INDEX(path
[depth
].p_hdr
))
1200 return le32_to_cpu(path
[depth
].p_idx
[1].ei_block
);
1205 return EXT_MAX_BLOCK
;
1209 * ext4_ext_next_leaf_block:
1210 * returns first allocated block from next leaf or EXT_MAX_BLOCK
1212 static ext4_lblk_t
ext4_ext_next_leaf_block(struct inode
*inode
,
1213 struct ext4_ext_path
*path
)
1217 BUG_ON(path
== NULL
);
1218 depth
= path
->p_depth
;
1220 /* zero-tree has no leaf blocks at all */
1222 return EXT_MAX_BLOCK
;
1224 /* go to index block */
1227 while (depth
>= 0) {
1228 if (path
[depth
].p_idx
!=
1229 EXT_LAST_INDEX(path
[depth
].p_hdr
))
1230 return (ext4_lblk_t
)
1231 le32_to_cpu(path
[depth
].p_idx
[1].ei_block
);
1235 return EXT_MAX_BLOCK
;
1239 * ext4_ext_correct_indexes:
1240 * if leaf gets modified and modified extent is first in the leaf,
1241 * then we have to correct all indexes above.
1242 * TODO: do we need to correct tree in all cases?
1244 static int ext4_ext_correct_indexes(handle_t
*handle
, struct inode
*inode
,
1245 struct ext4_ext_path
*path
)
1247 struct ext4_extent_header
*eh
;
1248 int depth
= ext_depth(inode
);
1249 struct ext4_extent
*ex
;
1253 eh
= path
[depth
].p_hdr
;
1254 ex
= path
[depth
].p_ext
;
1259 /* there is no tree at all */
1263 if (ex
!= EXT_FIRST_EXTENT(eh
)) {
1264 /* we correct tree if first leaf got modified only */
1269 * TODO: we need correction if border is smaller than current one
1272 border
= path
[depth
].p_ext
->ee_block
;
1273 err
= ext4_ext_get_access(handle
, inode
, path
+ k
);
1276 path
[k
].p_idx
->ei_block
= border
;
1277 err
= ext4_ext_dirty(handle
, inode
, path
+ k
);
1282 /* change all left-side indexes */
1283 if (path
[k
+1].p_idx
!= EXT_FIRST_INDEX(path
[k
+1].p_hdr
))
1285 err
= ext4_ext_get_access(handle
, inode
, path
+ k
);
1288 path
[k
].p_idx
->ei_block
= border
;
1289 err
= ext4_ext_dirty(handle
, inode
, path
+ k
);
1298 ext4_can_extents_be_merged(struct inode
*inode
, struct ext4_extent
*ex1
,
1299 struct ext4_extent
*ex2
)
1301 unsigned short ext1_ee_len
, ext2_ee_len
, max_len
;
1304 * Make sure that either both extents are uninitialized, or
1307 if (ext4_ext_is_uninitialized(ex1
) ^ ext4_ext_is_uninitialized(ex2
))
1310 if (ext4_ext_is_uninitialized(ex1
))
1311 max_len
= EXT_UNINIT_MAX_LEN
;
1313 max_len
= EXT_INIT_MAX_LEN
;
1315 ext1_ee_len
= ext4_ext_get_actual_len(ex1
);
1316 ext2_ee_len
= ext4_ext_get_actual_len(ex2
);
1318 if (le32_to_cpu(ex1
->ee_block
) + ext1_ee_len
!=
1319 le32_to_cpu(ex2
->ee_block
))
1323 * To allow future support for preallocated extents to be added
1324 * as an RO_COMPAT feature, refuse to merge to extents if
1325 * this can result in the top bit of ee_len being set.
1327 if (ext1_ee_len
+ ext2_ee_len
> max_len
)
1329 #ifdef AGGRESSIVE_TEST
1330 if (ext1_ee_len
>= 4)
1334 if (ext_pblock(ex1
) + ext1_ee_len
== ext_pblock(ex2
))
1340 * This function tries to merge the "ex" extent to the next extent in the tree.
1341 * It always tries to merge towards right. If you want to merge towards
1342 * left, pass "ex - 1" as argument instead of "ex".
1343 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1344 * 1 if they got merged.
1346 int ext4_ext_try_to_merge(struct inode
*inode
,
1347 struct ext4_ext_path
*path
,
1348 struct ext4_extent
*ex
)
1350 struct ext4_extent_header
*eh
;
1351 unsigned int depth
, len
;
1353 int uninitialized
= 0;
1355 depth
= ext_depth(inode
);
1356 BUG_ON(path
[depth
].p_hdr
== NULL
);
1357 eh
= path
[depth
].p_hdr
;
1359 while (ex
< EXT_LAST_EXTENT(eh
)) {
1360 if (!ext4_can_extents_be_merged(inode
, ex
, ex
+ 1))
1362 /* merge with next extent! */
1363 if (ext4_ext_is_uninitialized(ex
))
1365 ex
->ee_len
= cpu_to_le16(ext4_ext_get_actual_len(ex
)
1366 + ext4_ext_get_actual_len(ex
+ 1));
1368 ext4_ext_mark_uninitialized(ex
);
1370 if (ex
+ 1 < EXT_LAST_EXTENT(eh
)) {
1371 len
= (EXT_LAST_EXTENT(eh
) - ex
- 1)
1372 * sizeof(struct ext4_extent
);
1373 memmove(ex
+ 1, ex
+ 2, len
);
1375 le16_add_cpu(&eh
->eh_entries
, -1);
1377 WARN_ON(eh
->eh_entries
== 0);
1378 if (!eh
->eh_entries
)
1379 ext4_error(inode
->i_sb
, "ext4_ext_try_to_merge",
1380 "inode#%lu, eh->eh_entries = 0!", inode
->i_ino
);
1387 * check if a portion of the "newext" extent overlaps with an
1390 * If there is an overlap discovered, it updates the length of the newext
1391 * such that there will be no overlap, and then returns 1.
1392 * If there is no overlap found, it returns 0.
1394 unsigned int ext4_ext_check_overlap(struct inode
*inode
,
1395 struct ext4_extent
*newext
,
1396 struct ext4_ext_path
*path
)
1399 unsigned int depth
, len1
;
1400 unsigned int ret
= 0;
1402 b1
= le32_to_cpu(newext
->ee_block
);
1403 len1
= ext4_ext_get_actual_len(newext
);
1404 depth
= ext_depth(inode
);
1405 if (!path
[depth
].p_ext
)
1407 b2
= le32_to_cpu(path
[depth
].p_ext
->ee_block
);
1410 * get the next allocated block if the extent in the path
1411 * is before the requested block(s)
1414 b2
= ext4_ext_next_allocated_block(path
);
1415 if (b2
== EXT_MAX_BLOCK
)
1419 /* check for wrap through zero on extent logical start block*/
1420 if (b1
+ len1
< b1
) {
1421 len1
= EXT_MAX_BLOCK
- b1
;
1422 newext
->ee_len
= cpu_to_le16(len1
);
1426 /* check for overlap */
1427 if (b1
+ len1
> b2
) {
1428 newext
->ee_len
= cpu_to_le16(b2
- b1
);
1436 * ext4_ext_insert_extent:
1437 * tries to merge requsted extent into the existing extent or
1438 * inserts requested extent as new one into the tree,
1439 * creating new leaf in the no-space case.
1441 int ext4_ext_insert_extent(handle_t
*handle
, struct inode
*inode
,
1442 struct ext4_ext_path
*path
,
1443 struct ext4_extent
*newext
)
1445 struct ext4_extent_header
* eh
;
1446 struct ext4_extent
*ex
, *fex
;
1447 struct ext4_extent
*nearex
; /* nearest extent */
1448 struct ext4_ext_path
*npath
= NULL
;
1449 int depth
, len
, err
;
1451 unsigned uninitialized
= 0;
1453 BUG_ON(ext4_ext_get_actual_len(newext
) == 0);
1454 depth
= ext_depth(inode
);
1455 ex
= path
[depth
].p_ext
;
1456 BUG_ON(path
[depth
].p_hdr
== NULL
);
1458 /* try to insert block into found extent and return */
1459 if (ex
&& ext4_can_extents_be_merged(inode
, ex
, newext
)) {
1460 ext_debug("append %d block to %d:%d (from %llu)\n",
1461 ext4_ext_get_actual_len(newext
),
1462 le32_to_cpu(ex
->ee_block
),
1463 ext4_ext_get_actual_len(ex
), ext_pblock(ex
));
1464 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
1469 * ext4_can_extents_be_merged should have checked that either
1470 * both extents are uninitialized, or both aren't. Thus we
1471 * need to check only one of them here.
1473 if (ext4_ext_is_uninitialized(ex
))
1475 ex
->ee_len
= cpu_to_le16(ext4_ext_get_actual_len(ex
)
1476 + ext4_ext_get_actual_len(newext
));
1478 ext4_ext_mark_uninitialized(ex
);
1479 eh
= path
[depth
].p_hdr
;
1485 depth
= ext_depth(inode
);
1486 eh
= path
[depth
].p_hdr
;
1487 if (le16_to_cpu(eh
->eh_entries
) < le16_to_cpu(eh
->eh_max
))
1490 /* probably next leaf has space for us? */
1491 fex
= EXT_LAST_EXTENT(eh
);
1492 next
= ext4_ext_next_leaf_block(inode
, path
);
1493 if (le32_to_cpu(newext
->ee_block
) > le32_to_cpu(fex
->ee_block
)
1494 && next
!= EXT_MAX_BLOCK
) {
1495 ext_debug("next leaf block - %d\n", next
);
1496 BUG_ON(npath
!= NULL
);
1497 npath
= ext4_ext_find_extent(inode
, next
, NULL
);
1499 return PTR_ERR(npath
);
1500 BUG_ON(npath
->p_depth
!= path
->p_depth
);
1501 eh
= npath
[depth
].p_hdr
;
1502 if (le16_to_cpu(eh
->eh_entries
) < le16_to_cpu(eh
->eh_max
)) {
1503 ext_debug("next leaf isnt full(%d)\n",
1504 le16_to_cpu(eh
->eh_entries
));
1508 ext_debug("next leaf has no free space(%d,%d)\n",
1509 le16_to_cpu(eh
->eh_entries
), le16_to_cpu(eh
->eh_max
));
1513 * There is no free space in the found leaf.
1514 * We're gonna add a new leaf in the tree.
1516 err
= ext4_ext_create_new_leaf(handle
, inode
, path
, newext
);
1519 depth
= ext_depth(inode
);
1520 eh
= path
[depth
].p_hdr
;
1523 nearex
= path
[depth
].p_ext
;
1525 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
1530 /* there is no extent in this leaf, create first one */
1531 ext_debug("first extent in the leaf: %d:%llu:%d\n",
1532 le32_to_cpu(newext
->ee_block
),
1534 ext4_ext_get_actual_len(newext
));
1535 path
[depth
].p_ext
= EXT_FIRST_EXTENT(eh
);
1536 } else if (le32_to_cpu(newext
->ee_block
)
1537 > le32_to_cpu(nearex
->ee_block
)) {
1538 /* BUG_ON(newext->ee_block == nearex->ee_block); */
1539 if (nearex
!= EXT_LAST_EXTENT(eh
)) {
1540 len
= EXT_MAX_EXTENT(eh
) - nearex
;
1541 len
= (len
- 1) * sizeof(struct ext4_extent
);
1542 len
= len
< 0 ? 0 : len
;
1543 ext_debug("insert %d:%llu:%d after: nearest 0x%p, "
1544 "move %d from 0x%p to 0x%p\n",
1545 le32_to_cpu(newext
->ee_block
),
1547 ext4_ext_get_actual_len(newext
),
1548 nearex
, len
, nearex
+ 1, nearex
+ 2);
1549 memmove(nearex
+ 2, nearex
+ 1, len
);
1551 path
[depth
].p_ext
= nearex
+ 1;
1553 BUG_ON(newext
->ee_block
== nearex
->ee_block
);
1554 len
= (EXT_MAX_EXTENT(eh
) - nearex
) * sizeof(struct ext4_extent
);
1555 len
= len
< 0 ? 0 : len
;
1556 ext_debug("insert %d:%llu:%d before: nearest 0x%p, "
1557 "move %d from 0x%p to 0x%p\n",
1558 le32_to_cpu(newext
->ee_block
),
1560 ext4_ext_get_actual_len(newext
),
1561 nearex
, len
, nearex
+ 1, nearex
+ 2);
1562 memmove(nearex
+ 1, nearex
, len
);
1563 path
[depth
].p_ext
= nearex
;
1566 le16_add_cpu(&eh
->eh_entries
, 1);
1567 nearex
= path
[depth
].p_ext
;
1568 nearex
->ee_block
= newext
->ee_block
;
1569 ext4_ext_store_pblock(nearex
, ext_pblock(newext
));
1570 nearex
->ee_len
= newext
->ee_len
;
1573 /* try to merge extents to the right */
1574 ext4_ext_try_to_merge(inode
, path
, nearex
);
1576 /* try to merge extents to the left */
1578 /* time to correct all indexes above */
1579 err
= ext4_ext_correct_indexes(handle
, inode
, path
);
1583 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
1587 ext4_ext_drop_refs(npath
);
1590 ext4_ext_tree_changed(inode
);
1591 ext4_ext_invalidate_cache(inode
);
1596 ext4_ext_put_in_cache(struct inode
*inode
, ext4_lblk_t block
,
1597 __u32 len
, ext4_fsblk_t start
, int type
)
1599 struct ext4_ext_cache
*cex
;
1601 cex
= &EXT4_I(inode
)->i_cached_extent
;
1602 cex
->ec_type
= type
;
1603 cex
->ec_block
= block
;
1605 cex
->ec_start
= start
;
1609 * ext4_ext_put_gap_in_cache:
1610 * calculate boundaries of the gap that the requested block fits into
1611 * and cache this gap
1614 ext4_ext_put_gap_in_cache(struct inode
*inode
, struct ext4_ext_path
*path
,
1617 int depth
= ext_depth(inode
);
1620 struct ext4_extent
*ex
;
1622 ex
= path
[depth
].p_ext
;
1624 /* there is no extent yet, so gap is [0;-] */
1626 len
= EXT_MAX_BLOCK
;
1627 ext_debug("cache gap(whole file):");
1628 } else if (block
< le32_to_cpu(ex
->ee_block
)) {
1630 len
= le32_to_cpu(ex
->ee_block
) - block
;
1631 ext_debug("cache gap(before): %u [%u:%u]",
1633 le32_to_cpu(ex
->ee_block
),
1634 ext4_ext_get_actual_len(ex
));
1635 } else if (block
>= le32_to_cpu(ex
->ee_block
)
1636 + ext4_ext_get_actual_len(ex
)) {
1638 lblock
= le32_to_cpu(ex
->ee_block
)
1639 + ext4_ext_get_actual_len(ex
);
1641 next
= ext4_ext_next_allocated_block(path
);
1642 ext_debug("cache gap(after): [%u:%u] %u",
1643 le32_to_cpu(ex
->ee_block
),
1644 ext4_ext_get_actual_len(ex
),
1646 BUG_ON(next
== lblock
);
1647 len
= next
- lblock
;
1653 ext_debug(" -> %u:%lu\n", lblock
, len
);
1654 ext4_ext_put_in_cache(inode
, lblock
, len
, 0, EXT4_EXT_CACHE_GAP
);
1658 ext4_ext_in_cache(struct inode
*inode
, ext4_lblk_t block
,
1659 struct ext4_extent
*ex
)
1661 struct ext4_ext_cache
*cex
;
1663 cex
= &EXT4_I(inode
)->i_cached_extent
;
1665 /* has cache valid data? */
1666 if (cex
->ec_type
== EXT4_EXT_CACHE_NO
)
1667 return EXT4_EXT_CACHE_NO
;
1669 BUG_ON(cex
->ec_type
!= EXT4_EXT_CACHE_GAP
&&
1670 cex
->ec_type
!= EXT4_EXT_CACHE_EXTENT
);
1671 if (block
>= cex
->ec_block
&& block
< cex
->ec_block
+ cex
->ec_len
) {
1672 ex
->ee_block
= cpu_to_le32(cex
->ec_block
);
1673 ext4_ext_store_pblock(ex
, cex
->ec_start
);
1674 ex
->ee_len
= cpu_to_le16(cex
->ec_len
);
1675 ext_debug("%u cached by %u:%u:%llu\n",
1677 cex
->ec_block
, cex
->ec_len
, cex
->ec_start
);
1678 return cex
->ec_type
;
1682 return EXT4_EXT_CACHE_NO
;
1687 * removes index from the index block.
1688 * It's used in truncate case only, thus all requests are for
1689 * last index in the block only.
1691 static int ext4_ext_rm_idx(handle_t
*handle
, struct inode
*inode
,
1692 struct ext4_ext_path
*path
)
1694 struct buffer_head
*bh
;
1698 /* free index block */
1700 leaf
= idx_pblock(path
->p_idx
);
1701 BUG_ON(path
->p_hdr
->eh_entries
== 0);
1702 err
= ext4_ext_get_access(handle
, inode
, path
);
1705 le16_add_cpu(&path
->p_hdr
->eh_entries
, -1);
1706 err
= ext4_ext_dirty(handle
, inode
, path
);
1709 ext_debug("index is empty, remove it, free block %llu\n", leaf
);
1710 bh
= sb_find_get_block(inode
->i_sb
, leaf
);
1711 ext4_forget(handle
, 1, inode
, bh
, leaf
);
1712 ext4_free_blocks(handle
, inode
, leaf
, 1, 1);
1717 * ext4_ext_calc_credits_for_insert:
1718 * This routine returns max. credits that the extent tree can consume.
1719 * It should be OK for low-performance paths like ->writepage()
1720 * To allow many writing processes to fit into a single transaction,
1721 * the caller should calculate credits under i_data_sem and
1722 * pass the actual path.
1724 int ext4_ext_calc_credits_for_insert(struct inode
*inode
,
1725 struct ext4_ext_path
*path
)
1730 /* probably there is space in leaf? */
1731 depth
= ext_depth(inode
);
1732 if (le16_to_cpu(path
[depth
].p_hdr
->eh_entries
)
1733 < le16_to_cpu(path
[depth
].p_hdr
->eh_max
))
1738 * given 32-bit logical block (4294967296 blocks), max. tree
1739 * can be 4 levels in depth -- 4 * 340^4 == 53453440000.
1740 * Let's also add one more level for imbalance.
1744 /* allocation of new data block(s) */
1748 * tree can be full, so it would need to grow in depth:
1749 * we need one credit to modify old root, credits for
1750 * new root will be added in split accounting
1755 * Index split can happen, we would need:
1756 * allocate intermediate indexes (bitmap + group)
1757 * + change two blocks at each level, but root (already included)
1759 needed
+= (depth
* 2) + (depth
* 2);
1761 /* any allocation modifies superblock */
1767 static int ext4_remove_blocks(handle_t
*handle
, struct inode
*inode
,
1768 struct ext4_extent
*ex
,
1769 ext4_lblk_t from
, ext4_lblk_t to
)
1771 struct buffer_head
*bh
;
1772 unsigned short ee_len
= ext4_ext_get_actual_len(ex
);
1773 int i
, metadata
= 0;
1775 if (S_ISDIR(inode
->i_mode
) || S_ISLNK(inode
->i_mode
))
1777 #ifdef EXTENTS_STATS
1779 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
1780 spin_lock(&sbi
->s_ext_stats_lock
);
1781 sbi
->s_ext_blocks
+= ee_len
;
1782 sbi
->s_ext_extents
++;
1783 if (ee_len
< sbi
->s_ext_min
)
1784 sbi
->s_ext_min
= ee_len
;
1785 if (ee_len
> sbi
->s_ext_max
)
1786 sbi
->s_ext_max
= ee_len
;
1787 if (ext_depth(inode
) > sbi
->s_depth_max
)
1788 sbi
->s_depth_max
= ext_depth(inode
);
1789 spin_unlock(&sbi
->s_ext_stats_lock
);
1792 if (from
>= le32_to_cpu(ex
->ee_block
)
1793 && to
== le32_to_cpu(ex
->ee_block
) + ee_len
- 1) {
1798 num
= le32_to_cpu(ex
->ee_block
) + ee_len
- from
;
1799 start
= ext_pblock(ex
) + ee_len
- num
;
1800 ext_debug("free last %u blocks starting %llu\n", num
, start
);
1801 for (i
= 0; i
< num
; i
++) {
1802 bh
= sb_find_get_block(inode
->i_sb
, start
+ i
);
1803 ext4_forget(handle
, 0, inode
, bh
, start
+ i
);
1805 ext4_free_blocks(handle
, inode
, start
, num
, metadata
);
1806 } else if (from
== le32_to_cpu(ex
->ee_block
)
1807 && to
<= le32_to_cpu(ex
->ee_block
) + ee_len
- 1) {
1808 printk(KERN_INFO
"strange request: removal %u-%u from %u:%u\n",
1809 from
, to
, le32_to_cpu(ex
->ee_block
), ee_len
);
1811 printk(KERN_INFO
"strange request: removal(2) "
1812 "%u-%u from %u:%u\n",
1813 from
, to
, le32_to_cpu(ex
->ee_block
), ee_len
);
1819 ext4_ext_rm_leaf(handle_t
*handle
, struct inode
*inode
,
1820 struct ext4_ext_path
*path
, ext4_lblk_t start
)
1822 int err
= 0, correct_index
= 0;
1823 int depth
= ext_depth(inode
), credits
;
1824 struct ext4_extent_header
*eh
;
1825 ext4_lblk_t a
, b
, block
;
1827 ext4_lblk_t ex_ee_block
;
1828 unsigned short ex_ee_len
;
1829 unsigned uninitialized
= 0;
1830 struct ext4_extent
*ex
;
1832 /* the header must be checked already in ext4_ext_remove_space() */
1833 ext_debug("truncate since %u in leaf\n", start
);
1834 if (!path
[depth
].p_hdr
)
1835 path
[depth
].p_hdr
= ext_block_hdr(path
[depth
].p_bh
);
1836 eh
= path
[depth
].p_hdr
;
1839 /* find where to start removing */
1840 ex
= EXT_LAST_EXTENT(eh
);
1842 ex_ee_block
= le32_to_cpu(ex
->ee_block
);
1843 if (ext4_ext_is_uninitialized(ex
))
1845 ex_ee_len
= ext4_ext_get_actual_len(ex
);
1847 while (ex
>= EXT_FIRST_EXTENT(eh
) &&
1848 ex_ee_block
+ ex_ee_len
> start
) {
1849 ext_debug("remove ext %lu:%u\n", ex_ee_block
, ex_ee_len
);
1850 path
[depth
].p_ext
= ex
;
1852 a
= ex_ee_block
> start
? ex_ee_block
: start
;
1853 b
= ex_ee_block
+ ex_ee_len
- 1 < EXT_MAX_BLOCK
?
1854 ex_ee_block
+ ex_ee_len
- 1 : EXT_MAX_BLOCK
;
1856 ext_debug(" border %u:%u\n", a
, b
);
1858 if (a
!= ex_ee_block
&& b
!= ex_ee_block
+ ex_ee_len
- 1) {
1862 } else if (a
!= ex_ee_block
) {
1863 /* remove tail of the extent */
1864 block
= ex_ee_block
;
1866 } else if (b
!= ex_ee_block
+ ex_ee_len
- 1) {
1867 /* remove head of the extent */
1870 /* there is no "make a hole" API yet */
1873 /* remove whole extent: excellent! */
1874 block
= ex_ee_block
;
1876 BUG_ON(a
!= ex_ee_block
);
1877 BUG_ON(b
!= ex_ee_block
+ ex_ee_len
- 1);
1880 /* at present, extent can't cross block group: */
1881 /* leaf + bitmap + group desc + sb + inode */
1883 if (ex
== EXT_FIRST_EXTENT(eh
)) {
1885 credits
+= (ext_depth(inode
)) + 1;
1888 credits
+= 2 * EXT4_QUOTA_TRANS_BLOCKS(inode
->i_sb
);
1891 handle
= ext4_ext_journal_restart(handle
, credits
);
1892 if (IS_ERR(handle
)) {
1893 err
= PTR_ERR(handle
);
1897 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
1901 err
= ext4_remove_blocks(handle
, inode
, ex
, a
, b
);
1906 /* this extent is removed; mark slot entirely unused */
1907 ext4_ext_store_pblock(ex
, 0);
1908 le16_add_cpu(&eh
->eh_entries
, -1);
1911 ex
->ee_block
= cpu_to_le32(block
);
1912 ex
->ee_len
= cpu_to_le16(num
);
1914 * Do not mark uninitialized if all the blocks in the
1915 * extent have been removed.
1917 if (uninitialized
&& num
)
1918 ext4_ext_mark_uninitialized(ex
);
1920 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
1924 ext_debug("new extent: %u:%u:%llu\n", block
, num
,
1927 ex_ee_block
= le32_to_cpu(ex
->ee_block
);
1928 ex_ee_len
= ext4_ext_get_actual_len(ex
);
1931 if (correct_index
&& eh
->eh_entries
)
1932 err
= ext4_ext_correct_indexes(handle
, inode
, path
);
1934 /* if this leaf is free, then we should
1935 * remove it from index block above */
1936 if (err
== 0 && eh
->eh_entries
== 0 && path
[depth
].p_bh
!= NULL
)
1937 err
= ext4_ext_rm_idx(handle
, inode
, path
+ depth
);
1944 * ext4_ext_more_to_rm:
1945 * returns 1 if current index has to be freed (even partial)
1948 ext4_ext_more_to_rm(struct ext4_ext_path
*path
)
1950 BUG_ON(path
->p_idx
== NULL
);
1952 if (path
->p_idx
< EXT_FIRST_INDEX(path
->p_hdr
))
1956 * if truncate on deeper level happened, it wasn't partial,
1957 * so we have to consider current index for truncation
1959 if (le16_to_cpu(path
->p_hdr
->eh_entries
) == path
->p_block
)
1964 static int ext4_ext_remove_space(struct inode
*inode
, ext4_lblk_t start
)
1966 struct super_block
*sb
= inode
->i_sb
;
1967 int depth
= ext_depth(inode
);
1968 struct ext4_ext_path
*path
;
1972 ext_debug("truncate since %u\n", start
);
1974 /* probably first extent we're gonna free will be last in block */
1975 handle
= ext4_journal_start(inode
, depth
+ 1);
1977 return PTR_ERR(handle
);
1979 ext4_ext_invalidate_cache(inode
);
1982 * We start scanning from right side, freeing all the blocks
1983 * after i_size and walking into the tree depth-wise.
1985 path
= kzalloc(sizeof(struct ext4_ext_path
) * (depth
+ 1), GFP_NOFS
);
1987 ext4_journal_stop(handle
);
1990 path
[0].p_hdr
= ext_inode_hdr(inode
);
1991 if (ext4_ext_check_header(inode
, path
[0].p_hdr
, depth
)) {
1995 path
[0].p_depth
= depth
;
1997 while (i
>= 0 && err
== 0) {
1999 /* this is leaf block */
2000 err
= ext4_ext_rm_leaf(handle
, inode
, path
, start
);
2001 /* root level has p_bh == NULL, brelse() eats this */
2002 brelse(path
[i
].p_bh
);
2003 path
[i
].p_bh
= NULL
;
2008 /* this is index block */
2009 if (!path
[i
].p_hdr
) {
2010 ext_debug("initialize header\n");
2011 path
[i
].p_hdr
= ext_block_hdr(path
[i
].p_bh
);
2014 if (!path
[i
].p_idx
) {
2015 /* this level hasn't been touched yet */
2016 path
[i
].p_idx
= EXT_LAST_INDEX(path
[i
].p_hdr
);
2017 path
[i
].p_block
= le16_to_cpu(path
[i
].p_hdr
->eh_entries
)+1;
2018 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2020 le16_to_cpu(path
[i
].p_hdr
->eh_entries
));
2022 /* we were already here, see at next index */
2026 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2027 i
, EXT_FIRST_INDEX(path
[i
].p_hdr
),
2029 if (ext4_ext_more_to_rm(path
+ i
)) {
2030 struct buffer_head
*bh
;
2031 /* go to the next level */
2032 ext_debug("move to level %d (block %llu)\n",
2033 i
+ 1, idx_pblock(path
[i
].p_idx
));
2034 memset(path
+ i
+ 1, 0, sizeof(*path
));
2035 bh
= sb_bread(sb
, idx_pblock(path
[i
].p_idx
));
2037 /* should we reset i_size? */
2041 if (WARN_ON(i
+ 1 > depth
)) {
2045 if (ext4_ext_check_header(inode
, ext_block_hdr(bh
),
2050 path
[i
+ 1].p_bh
= bh
;
2052 /* save actual number of indexes since this
2053 * number is changed at the next iteration */
2054 path
[i
].p_block
= le16_to_cpu(path
[i
].p_hdr
->eh_entries
);
2057 /* we finished processing this index, go up */
2058 if (path
[i
].p_hdr
->eh_entries
== 0 && i
> 0) {
2059 /* index is empty, remove it;
2060 * handle must be already prepared by the
2061 * truncatei_leaf() */
2062 err
= ext4_ext_rm_idx(handle
, inode
, path
+ i
);
2064 /* root level has p_bh == NULL, brelse() eats this */
2065 brelse(path
[i
].p_bh
);
2066 path
[i
].p_bh
= NULL
;
2068 ext_debug("return to level %d\n", i
);
2072 /* TODO: flexible tree reduction should be here */
2073 if (path
->p_hdr
->eh_entries
== 0) {
2075 * truncate to zero freed all the tree,
2076 * so we need to correct eh_depth
2078 err
= ext4_ext_get_access(handle
, inode
, path
);
2080 ext_inode_hdr(inode
)->eh_depth
= 0;
2081 ext_inode_hdr(inode
)->eh_max
=
2082 cpu_to_le16(ext4_ext_space_root(inode
));
2083 err
= ext4_ext_dirty(handle
, inode
, path
);
2087 ext4_ext_tree_changed(inode
);
2088 ext4_ext_drop_refs(path
);
2090 ext4_journal_stop(handle
);
2096 * called at mount time
2098 void ext4_ext_init(struct super_block
*sb
)
2101 * possible initialization would be here
2104 if (test_opt(sb
, EXTENTS
)) {
2105 printk("EXT4-fs: file extents enabled");
2106 #ifdef AGGRESSIVE_TEST
2107 printk(", aggressive tests");
2109 #ifdef CHECK_BINSEARCH
2110 printk(", check binsearch");
2112 #ifdef EXTENTS_STATS
2116 #ifdef EXTENTS_STATS
2117 spin_lock_init(&EXT4_SB(sb
)->s_ext_stats_lock
);
2118 EXT4_SB(sb
)->s_ext_min
= 1 << 30;
2119 EXT4_SB(sb
)->s_ext_max
= 0;
2125 * called at umount time
2127 void ext4_ext_release(struct super_block
*sb
)
2129 if (!test_opt(sb
, EXTENTS
))
2132 #ifdef EXTENTS_STATS
2133 if (EXT4_SB(sb
)->s_ext_blocks
&& EXT4_SB(sb
)->s_ext_extents
) {
2134 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2135 printk(KERN_ERR
"EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2136 sbi
->s_ext_blocks
, sbi
->s_ext_extents
,
2137 sbi
->s_ext_blocks
/ sbi
->s_ext_extents
);
2138 printk(KERN_ERR
"EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2139 sbi
->s_ext_min
, sbi
->s_ext_max
, sbi
->s_depth_max
);
2144 static void bi_complete(struct bio
*bio
, int error
)
2146 complete((struct completion
*)bio
->bi_private
);
2149 /* FIXME!! we need to try to merge to left or right after zero-out */
2150 static int ext4_ext_zeroout(struct inode
*inode
, struct ext4_extent
*ex
)
2154 int blkbits
, blocksize
;
2156 struct completion event
;
2157 unsigned int ee_len
, len
, done
, offset
;
2160 blkbits
= inode
->i_blkbits
;
2161 blocksize
= inode
->i_sb
->s_blocksize
;
2162 ee_len
= ext4_ext_get_actual_len(ex
);
2163 ee_pblock
= ext_pblock(ex
);
2165 /* convert ee_pblock to 512 byte sectors */
2166 ee_pblock
= ee_pblock
<< (blkbits
- 9);
2168 while (ee_len
> 0) {
2170 if (ee_len
> BIO_MAX_PAGES
)
2171 len
= BIO_MAX_PAGES
;
2175 bio
= bio_alloc(GFP_NOIO
, len
);
2178 bio
->bi_sector
= ee_pblock
;
2179 bio
->bi_bdev
= inode
->i_sb
->s_bdev
;
2183 while (done
< len
) {
2184 ret
= bio_add_page(bio
, ZERO_PAGE(0),
2186 if (ret
!= blocksize
) {
2188 * We can't add any more pages because of
2189 * hardware limitations. Start a new bio.
2194 offset
+= blocksize
;
2195 if (offset
>= PAGE_CACHE_SIZE
)
2199 init_completion(&event
);
2200 bio
->bi_private
= &event
;
2201 bio
->bi_end_io
= bi_complete
;
2202 submit_bio(WRITE
, bio
);
2203 wait_for_completion(&event
);
2205 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
2213 ee_pblock
+= done
<< (blkbits
- 9);
2218 #define EXT4_EXT_ZERO_LEN 7
2221 * This function is called by ext4_ext_get_blocks() if someone tries to write
2222 * to an uninitialized extent. It may result in splitting the uninitialized
2223 * extent into multiple extents (upto three - one initialized and two
2225 * There are three possibilities:
2226 * a> There is no split required: Entire extent should be initialized
2227 * b> Splits in two extents: Write is happening at either end of the extent
2228 * c> Splits in three extents: Somone is writing in middle of the extent
2230 static int ext4_ext_convert_to_initialized(handle_t
*handle
,
2231 struct inode
*inode
,
2232 struct ext4_ext_path
*path
,
2234 unsigned long max_blocks
)
2236 struct ext4_extent
*ex
, newex
, orig_ex
;
2237 struct ext4_extent
*ex1
= NULL
;
2238 struct ext4_extent
*ex2
= NULL
;
2239 struct ext4_extent
*ex3
= NULL
;
2240 struct ext4_extent_header
*eh
;
2241 ext4_lblk_t ee_block
;
2242 unsigned int allocated
, ee_len
, depth
;
2243 ext4_fsblk_t newblock
;
2247 depth
= ext_depth(inode
);
2248 eh
= path
[depth
].p_hdr
;
2249 ex
= path
[depth
].p_ext
;
2250 ee_block
= le32_to_cpu(ex
->ee_block
);
2251 ee_len
= ext4_ext_get_actual_len(ex
);
2252 allocated
= ee_len
- (iblock
- ee_block
);
2253 newblock
= iblock
- ee_block
+ ext_pblock(ex
);
2255 orig_ex
.ee_block
= ex
->ee_block
;
2256 orig_ex
.ee_len
= cpu_to_le16(ee_len
);
2257 ext4_ext_store_pblock(&orig_ex
, ext_pblock(ex
));
2259 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
2262 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
2263 if (ee_len
<= 2*EXT4_EXT_ZERO_LEN
) {
2264 err
= ext4_ext_zeroout(inode
, &orig_ex
);
2266 goto fix_extent_len
;
2267 /* update the extent length and mark as initialized */
2268 ex
->ee_block
= orig_ex
.ee_block
;
2269 ex
->ee_len
= orig_ex
.ee_len
;
2270 ext4_ext_store_pblock(ex
, ext_pblock(&orig_ex
));
2271 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2272 /* zeroed the full extent */
2276 /* ex1: ee_block to iblock - 1 : uninitialized */
2277 if (iblock
> ee_block
) {
2279 ex1
->ee_len
= cpu_to_le16(iblock
- ee_block
);
2280 ext4_ext_mark_uninitialized(ex1
);
2284 * for sanity, update the length of the ex2 extent before
2285 * we insert ex3, if ex1 is NULL. This is to avoid temporary
2286 * overlap of blocks.
2288 if (!ex1
&& allocated
> max_blocks
)
2289 ex2
->ee_len
= cpu_to_le16(max_blocks
);
2290 /* ex3: to ee_block + ee_len : uninitialised */
2291 if (allocated
> max_blocks
) {
2292 unsigned int newdepth
;
2293 /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
2294 if (allocated
<= EXT4_EXT_ZERO_LEN
) {
2295 /* Mark first half uninitialized.
2296 * Mark second half initialized and zero out the
2297 * initialized extent
2299 ex
->ee_block
= orig_ex
.ee_block
;
2300 ex
->ee_len
= cpu_to_le16(ee_len
- allocated
);
2301 ext4_ext_mark_uninitialized(ex
);
2302 ext4_ext_store_pblock(ex
, ext_pblock(&orig_ex
));
2303 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2306 ex3
->ee_block
= cpu_to_le32(iblock
);
2307 ext4_ext_store_pblock(ex3
, newblock
);
2308 ex3
->ee_len
= cpu_to_le16(allocated
);
2309 err
= ext4_ext_insert_extent(handle
, inode
, path
, ex3
);
2310 if (err
== -ENOSPC
) {
2311 err
= ext4_ext_zeroout(inode
, &orig_ex
);
2313 goto fix_extent_len
;
2314 ex
->ee_block
= orig_ex
.ee_block
;
2315 ex
->ee_len
= orig_ex
.ee_len
;
2316 ext4_ext_store_pblock(ex
, ext_pblock(&orig_ex
));
2317 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2318 /* zeroed the full extent */
2322 goto fix_extent_len
;
2325 * We need to zero out the second half because
2326 * an fallocate request can update file size and
2327 * converting the second half to initialized extent
2328 * implies that we can leak some junk data to user
2331 err
= ext4_ext_zeroout(inode
, ex3
);
2334 * We should actually mark the
2335 * second half as uninit and return error
2336 * Insert would have changed the extent
2338 depth
= ext_depth(inode
);
2339 ext4_ext_drop_refs(path
);
2340 path
= ext4_ext_find_extent(inode
,
2343 err
= PTR_ERR(path
);
2346 ex
= path
[depth
].p_ext
;
2347 err
= ext4_ext_get_access(handle
, inode
,
2351 ext4_ext_mark_uninitialized(ex
);
2352 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2356 /* zeroed the second half */
2360 ex3
->ee_block
= cpu_to_le32(iblock
+ max_blocks
);
2361 ext4_ext_store_pblock(ex3
, newblock
+ max_blocks
);
2362 ex3
->ee_len
= cpu_to_le16(allocated
- max_blocks
);
2363 ext4_ext_mark_uninitialized(ex3
);
2364 err
= ext4_ext_insert_extent(handle
, inode
, path
, ex3
);
2365 if (err
== -ENOSPC
) {
2366 err
= ext4_ext_zeroout(inode
, &orig_ex
);
2368 goto fix_extent_len
;
2369 /* update the extent length and mark as initialized */
2370 ex
->ee_block
= orig_ex
.ee_block
;
2371 ex
->ee_len
= orig_ex
.ee_len
;
2372 ext4_ext_store_pblock(ex
, ext_pblock(&orig_ex
));
2373 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2374 /* zeroed the full extent */
2378 goto fix_extent_len
;
2380 * The depth, and hence eh & ex might change
2381 * as part of the insert above.
2383 newdepth
= ext_depth(inode
);
2385 * update the extent length after successfull insert of the
2388 orig_ex
.ee_len
= cpu_to_le16(ee_len
-
2389 ext4_ext_get_actual_len(ex3
));
2390 if (newdepth
!= depth
) {
2392 ext4_ext_drop_refs(path
);
2393 path
= ext4_ext_find_extent(inode
, iblock
, path
);
2395 err
= PTR_ERR(path
);
2398 eh
= path
[depth
].p_hdr
;
2399 ex
= path
[depth
].p_ext
;
2403 err
= ext4_ext_get_access(handle
, inode
, path
+ depth
);
2407 allocated
= max_blocks
;
2409 /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
2410 * to insert a extent in the middle zerout directly
2411 * otherwise give the extent a chance to merge to left
2413 if (le16_to_cpu(orig_ex
.ee_len
) <= EXT4_EXT_ZERO_LEN
&&
2414 iblock
!= ee_block
) {
2415 err
= ext4_ext_zeroout(inode
, &orig_ex
);
2417 goto fix_extent_len
;
2418 /* update the extent length and mark as initialized */
2419 ex
->ee_block
= orig_ex
.ee_block
;
2420 ex
->ee_len
= orig_ex
.ee_len
;
2421 ext4_ext_store_pblock(ex
, ext_pblock(&orig_ex
));
2422 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2423 /* zero out the first half */
2428 * If there was a change of depth as part of the
2429 * insertion of ex3 above, we need to update the length
2430 * of the ex1 extent again here
2432 if (ex1
&& ex1
!= ex
) {
2434 ex1
->ee_len
= cpu_to_le16(iblock
- ee_block
);
2435 ext4_ext_mark_uninitialized(ex1
);
2438 /* ex2: iblock to iblock + maxblocks-1 : initialised */
2439 ex2
->ee_block
= cpu_to_le32(iblock
);
2440 ext4_ext_store_pblock(ex2
, newblock
);
2441 ex2
->ee_len
= cpu_to_le16(allocated
);
2445 * New (initialized) extent starts from the first block
2446 * in the current extent. i.e., ex2 == ex
2447 * We have to see if it can be merged with the extent
2450 if (ex2
> EXT_FIRST_EXTENT(eh
)) {
2452 * To merge left, pass "ex2 - 1" to try_to_merge(),
2453 * since it merges towards right _only_.
2455 ret
= ext4_ext_try_to_merge(inode
, path
, ex2
- 1);
2457 err
= ext4_ext_correct_indexes(handle
, inode
, path
);
2460 depth
= ext_depth(inode
);
2465 * Try to Merge towards right. This might be required
2466 * only when the whole extent is being written to.
2467 * i.e. ex2 == ex and ex3 == NULL.
2470 ret
= ext4_ext_try_to_merge(inode
, path
, ex2
);
2472 err
= ext4_ext_correct_indexes(handle
, inode
, path
);
2477 /* Mark modified extent as dirty */
2478 err
= ext4_ext_dirty(handle
, inode
, path
+ depth
);
2481 err
= ext4_ext_insert_extent(handle
, inode
, path
, &newex
);
2482 if (err
== -ENOSPC
) {
2483 err
= ext4_ext_zeroout(inode
, &orig_ex
);
2485 goto fix_extent_len
;
2486 /* update the extent length and mark as initialized */
2487 ex
->ee_block
= orig_ex
.ee_block
;
2488 ex
->ee_len
= orig_ex
.ee_len
;
2489 ext4_ext_store_pblock(ex
, ext_pblock(&orig_ex
));
2490 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2491 /* zero out the first half */
2494 goto fix_extent_len
;
2496 return err
? err
: allocated
;
2499 ex
->ee_block
= orig_ex
.ee_block
;
2500 ex
->ee_len
= orig_ex
.ee_len
;
2501 ext4_ext_store_pblock(ex
, ext_pblock(&orig_ex
));
2502 ext4_ext_mark_uninitialized(ex
);
2503 ext4_ext_dirty(handle
, inode
, path
+ depth
);
2508 * Block allocation/map/preallocation routine for extents based files
2511 * Need to be called with
2512 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
2513 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
2515 * return > 0, number of of blocks already mapped/allocated
2516 * if create == 0 and these are pre-allocated blocks
2517 * buffer head is unmapped
2518 * otherwise blocks are mapped
2520 * return = 0, if plain look up failed (blocks have not been allocated)
2521 * buffer head is unmapped
2523 * return < 0, error case.
2525 int ext4_ext_get_blocks(handle_t
*handle
, struct inode
*inode
,
2527 unsigned long max_blocks
, struct buffer_head
*bh_result
,
2528 int create
, int extend_disksize
)
2530 struct ext4_ext_path
*path
= NULL
;
2531 struct ext4_extent_header
*eh
;
2532 struct ext4_extent newex
, *ex
;
2533 ext4_fsblk_t goal
, newblock
;
2534 int err
= 0, depth
, ret
;
2535 unsigned long allocated
= 0;
2536 struct ext4_allocation_request ar
;
2538 __clear_bit(BH_New
, &bh_result
->b_state
);
2539 ext_debug("blocks %u/%lu requested for inode %u\n",
2540 iblock
, max_blocks
, inode
->i_ino
);
2542 /* check in cache */
2543 goal
= ext4_ext_in_cache(inode
, iblock
, &newex
);
2545 if (goal
== EXT4_EXT_CACHE_GAP
) {
2548 * block isn't allocated yet and
2549 * user doesn't want to allocate it
2553 /* we should allocate requested block */
2554 } else if (goal
== EXT4_EXT_CACHE_EXTENT
) {
2555 /* block is already allocated */
2557 - le32_to_cpu(newex
.ee_block
)
2558 + ext_pblock(&newex
);
2559 /* number of remaining blocks in the extent */
2560 allocated
= ext4_ext_get_actual_len(&newex
) -
2561 (iblock
- le32_to_cpu(newex
.ee_block
));
2568 /* find extent for this block */
2569 path
= ext4_ext_find_extent(inode
, iblock
, NULL
);
2571 err
= PTR_ERR(path
);
2576 depth
= ext_depth(inode
);
2579 * consistent leaf must not be empty;
2580 * this situation is possible, though, _during_ tree modification;
2581 * this is why assert can't be put in ext4_ext_find_extent()
2583 BUG_ON(path
[depth
].p_ext
== NULL
&& depth
!= 0);
2584 eh
= path
[depth
].p_hdr
;
2586 ex
= path
[depth
].p_ext
;
2588 ext4_lblk_t ee_block
= le32_to_cpu(ex
->ee_block
);
2589 ext4_fsblk_t ee_start
= ext_pblock(ex
);
2590 unsigned short ee_len
;
2593 * Uninitialized extents are treated as holes, except that
2594 * we split out initialized portions during a write.
2596 ee_len
= ext4_ext_get_actual_len(ex
);
2597 /* if found extent covers block, simply return it */
2598 if (iblock
>= ee_block
&& iblock
< ee_block
+ ee_len
) {
2599 newblock
= iblock
- ee_block
+ ee_start
;
2600 /* number of remaining blocks in the extent */
2601 allocated
= ee_len
- (iblock
- ee_block
);
2602 ext_debug("%u fit into %lu:%d -> %llu\n", iblock
,
2603 ee_block
, ee_len
, newblock
);
2605 /* Do not put uninitialized extent in the cache */
2606 if (!ext4_ext_is_uninitialized(ex
)) {
2607 ext4_ext_put_in_cache(inode
, ee_block
,
2609 EXT4_EXT_CACHE_EXTENT
);
2612 if (create
== EXT4_CREATE_UNINITIALIZED_EXT
)
2616 * We have blocks reserved already. We
2617 * return allocated blocks so that delalloc
2618 * won't do block reservation for us. But
2619 * the buffer head will be unmapped so that
2620 * a read from the block returns 0s.
2622 if (allocated
> max_blocks
)
2623 allocated
= max_blocks
;
2624 /* mark the buffer unwritten */
2625 __set_bit(BH_Unwritten
, &bh_result
->b_state
);
2629 ret
= ext4_ext_convert_to_initialized(handle
, inode
,
2642 * requested block isn't allocated yet;
2643 * we couldn't try to create block if create flag is zero
2647 * put just found gap into cache to speed up
2648 * subsequent requests
2650 ext4_ext_put_gap_in_cache(inode
, path
, iblock
);
2654 * Okay, we need to do block allocation. Lazily initialize the block
2655 * allocation info here if necessary.
2657 if (S_ISREG(inode
->i_mode
) && (!EXT4_I(inode
)->i_block_alloc_info
))
2658 ext4_init_block_alloc_info(inode
);
2660 /* find neighbour allocated blocks */
2662 err
= ext4_ext_search_left(inode
, path
, &ar
.lleft
, &ar
.pleft
);
2666 err
= ext4_ext_search_right(inode
, path
, &ar
.lright
, &ar
.pright
);
2671 * See if request is beyond maximum number of blocks we can have in
2672 * a single extent. For an initialized extent this limit is
2673 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
2674 * EXT_UNINIT_MAX_LEN.
2676 if (max_blocks
> EXT_INIT_MAX_LEN
&&
2677 create
!= EXT4_CREATE_UNINITIALIZED_EXT
)
2678 max_blocks
= EXT_INIT_MAX_LEN
;
2679 else if (max_blocks
> EXT_UNINIT_MAX_LEN
&&
2680 create
== EXT4_CREATE_UNINITIALIZED_EXT
)
2681 max_blocks
= EXT_UNINIT_MAX_LEN
;
2683 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
2684 newex
.ee_block
= cpu_to_le32(iblock
);
2685 newex
.ee_len
= cpu_to_le16(max_blocks
);
2686 err
= ext4_ext_check_overlap(inode
, &newex
, path
);
2688 allocated
= ext4_ext_get_actual_len(&newex
);
2690 allocated
= max_blocks
;
2692 /* allocate new block */
2694 ar
.goal
= ext4_ext_find_goal(inode
, path
, iblock
);
2695 ar
.logical
= iblock
;
2697 if (S_ISREG(inode
->i_mode
))
2698 ar
.flags
= EXT4_MB_HINT_DATA
;
2700 /* disable in-core preallocation for non-regular files */
2702 newblock
= ext4_mb_new_blocks(handle
, &ar
, &err
);
2705 ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
2706 goal
, newblock
, allocated
);
2708 /* try to insert new extent into found leaf and return */
2709 ext4_ext_store_pblock(&newex
, newblock
);
2710 newex
.ee_len
= cpu_to_le16(ar
.len
);
2711 if (create
== EXT4_CREATE_UNINITIALIZED_EXT
) /* Mark uninitialized */
2712 ext4_ext_mark_uninitialized(&newex
);
2713 err
= ext4_ext_insert_extent(handle
, inode
, path
, &newex
);
2715 /* free data blocks we just allocated */
2716 /* not a good idea to call discard here directly,
2717 * but otherwise we'd need to call it every free() */
2718 ext4_mb_discard_inode_preallocations(inode
);
2719 ext4_free_blocks(handle
, inode
, ext_pblock(&newex
),
2720 ext4_ext_get_actual_len(&newex
), 0);
2724 /* previous routine could use block we allocated */
2725 newblock
= ext_pblock(&newex
);
2726 allocated
= ext4_ext_get_actual_len(&newex
);
2728 if (extend_disksize
&& inode
->i_size
> EXT4_I(inode
)->i_disksize
)
2729 EXT4_I(inode
)->i_disksize
= inode
->i_size
;
2731 __set_bit(BH_New
, &bh_result
->b_state
);
2733 /* Cache only when it is _not_ an uninitialized extent */
2734 if (create
!= EXT4_CREATE_UNINITIALIZED_EXT
)
2735 ext4_ext_put_in_cache(inode
, iblock
, allocated
, newblock
,
2736 EXT4_EXT_CACHE_EXTENT
);
2738 if (allocated
> max_blocks
)
2739 allocated
= max_blocks
;
2740 ext4_ext_show_leaf(inode
, path
);
2741 __set_bit(BH_Mapped
, &bh_result
->b_state
);
2742 bh_result
->b_bdev
= inode
->i_sb
->s_bdev
;
2743 bh_result
->b_blocknr
= newblock
;
2746 ext4_ext_drop_refs(path
);
2749 return err
? err
: allocated
;
2752 void ext4_ext_truncate(struct inode
* inode
, struct page
*page
)
2754 struct address_space
*mapping
= inode
->i_mapping
;
2755 struct super_block
*sb
= inode
->i_sb
;
2756 ext4_lblk_t last_block
;
2761 * probably first extent we're gonna free will be last in block
2763 err
= ext4_writepage_trans_blocks(inode
) + 3;
2764 handle
= ext4_journal_start(inode
, err
);
2765 if (IS_ERR(handle
)) {
2767 clear_highpage(page
);
2768 flush_dcache_page(page
);
2770 page_cache_release(page
);
2776 ext4_block_truncate_page(handle
, page
, mapping
, inode
->i_size
);
2778 down_write(&EXT4_I(inode
)->i_data_sem
);
2779 ext4_ext_invalidate_cache(inode
);
2781 ext4_mb_discard_inode_preallocations(inode
);
2784 * TODO: optimization is possible here.
2785 * Probably we need not scan at all,
2786 * because page truncation is enough.
2788 if (ext4_orphan_add(handle
, inode
))
2791 /* we have to know where to truncate from in crash case */
2792 EXT4_I(inode
)->i_disksize
= inode
->i_size
;
2793 ext4_mark_inode_dirty(handle
, inode
);
2795 last_block
= (inode
->i_size
+ sb
->s_blocksize
- 1)
2796 >> EXT4_BLOCK_SIZE_BITS(sb
);
2797 err
= ext4_ext_remove_space(inode
, last_block
);
2799 /* In a multi-transaction truncate, we only make the final
2800 * transaction synchronous.
2807 * If this was a simple ftruncate() and the file will remain alive,
2808 * then we need to clear up the orphan record which we created above.
2809 * However, if this was a real unlink then we were called by
2810 * ext4_delete_inode(), and we allow that function to clean up the
2811 * orphan info for us.
2814 ext4_orphan_del(handle
, inode
);
2816 up_write(&EXT4_I(inode
)->i_data_sem
);
2817 inode
->i_mtime
= inode
->i_ctime
= ext4_current_time(inode
);
2818 ext4_mark_inode_dirty(handle
, inode
);
2819 ext4_journal_stop(handle
);
2823 * ext4_ext_writepage_trans_blocks:
2824 * calculate max number of blocks we could modify
2825 * in order to allocate new block for an inode
2827 int ext4_ext_writepage_trans_blocks(struct inode
*inode
, int num
)
2831 needed
= ext4_ext_calc_credits_for_insert(inode
, NULL
);
2833 /* caller wants to allocate num blocks, but note it includes sb */
2834 needed
= needed
* num
- (num
- 1);
2837 needed
+= 2 * EXT4_QUOTA_TRANS_BLOCKS(inode
->i_sb
);
2843 static void ext4_falloc_update_inode(struct inode
*inode
,
2844 int mode
, loff_t new_size
, int update_ctime
)
2846 struct timespec now
;
2849 now
= current_fs_time(inode
->i_sb
);
2850 if (!timespec_equal(&inode
->i_ctime
, &now
))
2851 inode
->i_ctime
= now
;
2854 * Update only when preallocation was requested beyond
2857 if (!(mode
& FALLOC_FL_KEEP_SIZE
) &&
2858 new_size
> i_size_read(inode
)) {
2859 i_size_write(inode
, new_size
);
2860 EXT4_I(inode
)->i_disksize
= new_size
;
2866 * preallocate space for a file. This implements ext4's fallocate inode
2867 * operation, which gets called from sys_fallocate system call.
2868 * For block-mapped files, posix_fallocate should fall back to the method
2869 * of writing zeroes to the required new blocks (the same behavior which is
2870 * expected for file systems which do not support fallocate() system call).
2872 long ext4_fallocate(struct inode
*inode
, int mode
, loff_t offset
, loff_t len
)
2877 unsigned long max_blocks
;
2881 struct buffer_head map_bh
;
2882 unsigned int credits
, blkbits
= inode
->i_blkbits
;
2885 * currently supporting (pre)allocate mode for extent-based
2888 if (!(EXT4_I(inode
)->i_flags
& EXT4_EXTENTS_FL
))
2891 /* preallocation to directories is currently not supported */
2892 if (S_ISDIR(inode
->i_mode
))
2895 block
= offset
>> blkbits
;
2897 * We can't just convert len to max_blocks because
2898 * If blocksize = 4096 offset = 3072 and len = 2048
2900 max_blocks
= (EXT4_BLOCK_ALIGN(len
+ offset
, blkbits
) >> blkbits
)
2903 * credits to insert 1 extent into extent tree + buffers to be able to
2904 * modify 1 super block, 1 block bitmap and 1 group descriptor.
2906 credits
= EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
) + 3;
2907 mutex_lock(&inode
->i_mutex
);
2909 while (ret
>= 0 && ret
< max_blocks
) {
2910 block
= block
+ ret
;
2911 max_blocks
= max_blocks
- ret
;
2912 handle
= ext4_journal_start(inode
, credits
);
2913 if (IS_ERR(handle
)) {
2914 ret
= PTR_ERR(handle
);
2917 ret
= ext4_get_blocks_wrap(handle
, inode
, block
,
2918 max_blocks
, &map_bh
,
2919 EXT4_CREATE_UNINITIALIZED_EXT
, 0);
2923 printk(KERN_ERR
"%s: ext4_ext_get_blocks "
2924 "returned error inode#%lu, block=%u, "
2925 "max_blocks=%lu", __func__
,
2926 inode
->i_ino
, block
, max_blocks
);
2928 ext4_mark_inode_dirty(handle
, inode
);
2929 ret2
= ext4_journal_stop(handle
);
2932 if ((block
+ ret
) >= (EXT4_BLOCK_ALIGN(offset
+ len
,
2933 blkbits
) >> blkbits
))
2934 new_size
= offset
+ len
;
2936 new_size
= (block
+ ret
) << blkbits
;
2938 ext4_falloc_update_inode(inode
, mode
, new_size
,
2939 buffer_new(&map_bh
));
2940 ext4_mark_inode_dirty(handle
, inode
);
2941 ret2
= ext4_journal_stop(handle
);
2945 if (ret
== -ENOSPC
&&
2946 ext4_should_retry_alloc(inode
->i_sb
, &retries
)) {
2950 mutex_unlock(&inode
->i_mutex
);
2951 return ret
> 0 ? ret2
: ret
;