2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public Licens
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 * mballoc.c contains the multiblocks allocation routines
27 * - test ext4_ext_search_left() and ext4_ext_search_right()
28 * - search for metadata in few groups
31 * - normalization should take into account whether file is still open
32 * - discard preallocations if no free space left (policy?)
33 * - don't normalize tails
35 * - reservation for superuser
38 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
39 * - track min/max extents in each group for better group selection
40 * - mb_mark_used() may allocate chunk right after splitting buddy
41 * - tree of groups sorted by number of free blocks
46 * The allocation request involve request for multiple number of blocks
47 * near to the goal(block) value specified.
49 * During initialization phase of the allocator we decide to use the group
50 * preallocation or inode preallocation depending on the size file. The
51 * size of the file could be the resulting file size we would have after
52 * allocation or the current file size which ever is larger. If the size is
53 * less that sbi->s_mb_stream_request we select the group
54 * preallocation. The default value of s_mb_stream_request is 16
55 * blocks. This can also be tuned via
56 * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms
57 * of number of blocks.
59 * The main motivation for having small file use group preallocation is to
60 * ensure that we have small file closer in the disk.
62 * First stage the allocator looks at the inode prealloc list
63 * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for
64 * this particular inode. The inode prealloc space is represented as:
66 * pa_lstart -> the logical start block for this prealloc space
67 * pa_pstart -> the physical start block for this prealloc space
68 * pa_len -> lenght for this prealloc space
69 * pa_free -> free space available in this prealloc space
71 * The inode preallocation space is used looking at the _logical_ start
72 * block. If only the logical file block falls within the range of prealloc
73 * space we will consume the particular prealloc space. This make sure that
74 * that the we have contiguous physical blocks representing the file blocks
76 * The important thing to be noted in case of inode prealloc space is that
77 * we don't modify the values associated to inode prealloc space except
80 * If we are not able to find blocks in the inode prealloc space and if we
81 * have the group allocation flag set then we look at the locality group
82 * prealloc space. These are per CPU prealloc list repreasented as
84 * ext4_sb_info.s_locality_groups[smp_processor_id()]
86 * The reason for having a per cpu locality group is to reduce the contention
87 * between CPUs. It is possible to get scheduled at this point.
89 * The locality group prealloc space is used looking at whether we have
90 * enough free space (pa_free) withing the prealloc space.
92 * If we can't allocate blocks via inode prealloc or/and locality group
93 * prealloc then we look at the buddy cache. The buddy cache is represented
94 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
95 * mapped to the buddy and bitmap information regarding different
96 * groups. The buddy information is attached to buddy cache inode so that
97 * we can access them through the page cache. The information regarding
98 * each group is loaded via ext4_mb_load_buddy. The information involve
99 * block bitmap and buddy information. The information are stored in the
103 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
106 * one block each for bitmap and buddy information. So for each group we
107 * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
108 * blocksize) blocks. So it can have information regarding groups_per_page
109 * which is blocks_per_page/2
111 * The buddy cache inode is not stored on disk. The inode is thrown
112 * away when the filesystem is unmounted.
114 * We look for count number of blocks in the buddy cache. If we were able
115 * to locate that many free blocks we return with additional information
116 * regarding rest of the contiguous physical block available
118 * Before allocating blocks via buddy cache we normalize the request
119 * blocks. This ensure we ask for more blocks that we needed. The extra
120 * blocks that we get after allocation is added to the respective prealloc
121 * list. In case of inode preallocation we follow a list of heuristics
122 * based on file size. This can be found in ext4_mb_normalize_request. If
123 * we are doing a group prealloc we try to normalize the request to
124 * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to
125 * 512 blocks. This can be tuned via
126 * /proc/fs/ext4/<partition/group_prealloc. The value is represented in
127 * terms of number of blocks. If we have mounted the file system with -O
128 * stripe=<value> option the group prealloc request is normalized to the
129 * stripe value (sbi->s_stripe)
131 * The regular allocator(using the buddy cache) support few tunables.
133 * /proc/fs/ext4/<partition>/min_to_scan
134 * /proc/fs/ext4/<partition>/max_to_scan
135 * /proc/fs/ext4/<partition>/order2_req
137 * The regular allocator use buddy scan only if the request len is power of
138 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
139 * value of s_mb_order2_reqs can be tuned via
140 * /proc/fs/ext4/<partition>/order2_req. If the request len is equal to
141 * stripe size (sbi->s_stripe), we try to search for contigous block in
142 * stripe size. This should result in better allocation on RAID setup. If
143 * not we search in the specific group using bitmap for best extents. The
144 * tunable min_to_scan and max_to_scan controll the behaviour here.
145 * min_to_scan indicate how long the mballoc __must__ look for a best
146 * extent and max_to_scanindicate how long the mballoc __can__ look for a
147 * best extent in the found extents. Searching for the blocks starts with
148 * the group specified as the goal value in allocation context via
149 * ac_g_ex. Each group is first checked based on the criteria whether it
150 * can used for allocation. ext4_mb_good_group explains how the groups are
153 * Both the prealloc space are getting populated as above. So for the first
154 * request we will hit the buddy cache which will result in this prealloc
155 * space getting filled. The prealloc space is then later used for the
156 * subsequent request.
160 * mballoc operates on the following data:
162 * - in-core buddy (actually includes buddy and bitmap)
163 * - preallocation descriptors (PAs)
165 * there are two types of preallocations:
167 * assiged to specific inode and can be used for this inode only.
168 * it describes part of inode's space preallocated to specific
169 * physical blocks. any block from that preallocated can be used
170 * independent. the descriptor just tracks number of blocks left
171 * unused. so, before taking some block from descriptor, one must
172 * make sure corresponded logical block isn't allocated yet. this
173 * also means that freeing any block within descriptor's range
174 * must discard all preallocated blocks.
176 * assigned to specific locality group which does not translate to
177 * permanent set of inodes: inode can join and leave group. space
178 * from this type of preallocation can be used for any inode. thus
179 * it's consumed from the beginning to the end.
181 * relation between them can be expressed as:
182 * in-core buddy = on-disk bitmap + preallocation descriptors
184 * this mean blocks mballoc considers used are:
185 * - allocated blocks (persistent)
186 * - preallocated blocks (non-persistent)
188 * consistency in mballoc world means that at any time a block is either
189 * free or used in ALL structures. notice: "any time" should not be read
190 * literally -- time is discrete and delimited by locks.
192 * to keep it simple, we don't use block numbers, instead we count number of
193 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
195 * all operations can be expressed as:
196 * - init buddy: buddy = on-disk + PAs
197 * - new PA: buddy += N; PA = N
198 * - use inode PA: on-disk += N; PA -= N
199 * - discard inode PA buddy -= on-disk - PA; PA = 0
200 * - use locality group PA on-disk += N; PA -= N
201 * - discard locality group PA buddy -= PA; PA = 0
202 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
203 * is used in real operation because we can't know actual used
204 * bits from PA, only from on-disk bitmap
206 * if we follow this strict logic, then all operations above should be atomic.
207 * given some of them can block, we'd have to use something like semaphores
208 * killing performance on high-end SMP hardware. let's try to relax it using
209 * the following knowledge:
210 * 1) if buddy is referenced, it's already initialized
211 * 2) while block is used in buddy and the buddy is referenced,
212 * nobody can re-allocate that block
213 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
214 * bit set and PA claims same block, it's OK. IOW, one can set bit in
215 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
218 * so, now we're building a concurrency table:
221 * blocks for PA are allocated in the buddy, buddy must be referenced
222 * until PA is linked to allocation group to avoid concurrent buddy init
224 * we need to make sure that either on-disk bitmap or PA has uptodate data
225 * given (3) we care that PA-=N operation doesn't interfere with init
227 * the simplest way would be to have buddy initialized by the discard
228 * - use locality group PA
229 * again PA-=N must be serialized with init
230 * - discard locality group PA
231 * the simplest way would be to have buddy initialized by the discard
234 * i_data_sem serializes them
236 * discard process must wait until PA isn't used by another process
237 * - use locality group PA
238 * some mutex should serialize them
239 * - discard locality group PA
240 * discard process must wait until PA isn't used by another process
243 * i_data_sem or another mutex should serializes them
245 * discard process must wait until PA isn't used by another process
246 * - use locality group PA
247 * nothing wrong here -- they're different PAs covering different blocks
248 * - discard locality group PA
249 * discard process must wait until PA isn't used by another process
251 * now we're ready to make few consequences:
252 * - PA is referenced and while it is no discard is possible
253 * - PA is referenced until block isn't marked in on-disk bitmap
254 * - PA changes only after on-disk bitmap
255 * - discard must not compete with init. either init is done before
256 * any discard or they're serialized somehow
257 * - buddy init as sum of on-disk bitmap and PAs is done atomically
259 * a special case when we've used PA to emptiness. no need to modify buddy
260 * in this case, but we should care about concurrent init
265 * Logic in few words:
270 * mark bits in on-disk bitmap
273 * - use preallocation:
274 * find proper PA (per-inode or group)
276 * mark bits in on-disk bitmap
282 * mark bits in on-disk bitmap
285 * - discard preallocations in group:
287 * move them onto local list
288 * load on-disk bitmap
290 * remove PA from object (inode or locality group)
291 * mark free blocks in-core
293 * - discard inode's preallocations:
300 * - bitlock on a group (group)
301 * - object (inode/locality) (object)
312 * - release consumed pa:
317 * - generate in-core bitmap:
321 * - discard all for given object (inode, locality group):
326 * - discard all for given group:
334 static inline void *mb_correct_addr_and_bit(int *bit
, void *addr
)
336 #if BITS_PER_LONG == 64
337 *bit
+= ((unsigned long) addr
& 7UL) << 3;
338 addr
= (void *) ((unsigned long) addr
& ~7UL);
339 #elif BITS_PER_LONG == 32
340 *bit
+= ((unsigned long) addr
& 3UL) << 3;
341 addr
= (void *) ((unsigned long) addr
& ~3UL);
343 #error "how many bits you are?!"
348 static inline int mb_test_bit(int bit
, void *addr
)
351 * ext4_test_bit on architecture like powerpc
352 * needs unsigned long aligned address
354 addr
= mb_correct_addr_and_bit(&bit
, addr
);
355 return ext4_test_bit(bit
, addr
);
358 static inline void mb_set_bit(int bit
, void *addr
)
360 addr
= mb_correct_addr_and_bit(&bit
, addr
);
361 ext4_set_bit(bit
, addr
);
364 static inline void mb_set_bit_atomic(spinlock_t
*lock
, int bit
, void *addr
)
366 addr
= mb_correct_addr_and_bit(&bit
, addr
);
367 ext4_set_bit_atomic(lock
, bit
, addr
);
370 static inline void mb_clear_bit(int bit
, void *addr
)
372 addr
= mb_correct_addr_and_bit(&bit
, addr
);
373 ext4_clear_bit(bit
, addr
);
376 static inline void mb_clear_bit_atomic(spinlock_t
*lock
, int bit
, void *addr
)
378 addr
= mb_correct_addr_and_bit(&bit
, addr
);
379 ext4_clear_bit_atomic(lock
, bit
, addr
);
382 static inline int mb_find_next_zero_bit(void *addr
, int max
, int start
)
385 addr
= mb_correct_addr_and_bit(&fix
, addr
);
389 return ext4_find_next_zero_bit(addr
, max
, start
) - fix
;
392 static inline int mb_find_next_bit(void *addr
, int max
, int start
)
395 addr
= mb_correct_addr_and_bit(&fix
, addr
);
399 return ext4_find_next_bit(addr
, max
, start
) - fix
;
402 static void *mb_find_buddy(struct ext4_buddy
*e4b
, int order
, int *max
)
406 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
409 if (order
> e4b
->bd_blkbits
+ 1) {
414 /* at order 0 we see each particular block */
415 *max
= 1 << (e4b
->bd_blkbits
+ 3);
417 return EXT4_MB_BITMAP(e4b
);
419 bb
= EXT4_MB_BUDDY(e4b
) + EXT4_SB(e4b
->bd_sb
)->s_mb_offsets
[order
];
420 *max
= EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[order
];
426 static void mb_free_blocks_double(struct inode
*inode
, struct ext4_buddy
*e4b
,
427 int first
, int count
)
430 struct super_block
*sb
= e4b
->bd_sb
;
432 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
434 BUG_ON(!ext4_is_group_locked(sb
, e4b
->bd_group
));
435 for (i
= 0; i
< count
; i
++) {
436 if (!mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
)) {
437 ext4_fsblk_t blocknr
;
438 blocknr
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
);
439 blocknr
+= first
+ i
;
441 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
443 ext4_error(sb
, __func__
, "double-free of inode"
444 " %lu's block %llu(bit %u in group %lu)\n",
445 inode
? inode
->i_ino
: 0, blocknr
,
446 first
+ i
, e4b
->bd_group
);
448 mb_clear_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
452 static void mb_mark_used_double(struct ext4_buddy
*e4b
, int first
, int count
)
456 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
458 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
459 for (i
= 0; i
< count
; i
++) {
460 BUG_ON(mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
));
461 mb_set_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
465 static void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
467 if (memcmp(e4b
->bd_info
->bb_bitmap
, bitmap
, e4b
->bd_sb
->s_blocksize
)) {
468 unsigned char *b1
, *b2
;
470 b1
= (unsigned char *) e4b
->bd_info
->bb_bitmap
;
471 b2
= (unsigned char *) bitmap
;
472 for (i
= 0; i
< e4b
->bd_sb
->s_blocksize
; i
++) {
473 if (b1
[i
] != b2
[i
]) {
474 printk("corruption in group %lu at byte %u(%u):"
475 " %x in copy != %x on disk/prealloc\n",
476 e4b
->bd_group
, i
, i
* 8, b1
[i
], b2
[i
]);
484 static inline void mb_free_blocks_double(struct inode
*inode
,
485 struct ext4_buddy
*e4b
, int first
, int count
)
489 static inline void mb_mark_used_double(struct ext4_buddy
*e4b
,
490 int first
, int count
)
494 static inline void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
500 #ifdef AGGRESSIVE_CHECK
502 #define MB_CHECK_ASSERT(assert) \
506 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
507 function, file, line, # assert); \
512 static int __mb_check_buddy(struct ext4_buddy
*e4b
, char *file
,
513 const char *function
, int line
)
515 struct super_block
*sb
= e4b
->bd_sb
;
516 int order
= e4b
->bd_blkbits
+ 1;
523 struct ext4_group_info
*grp
;
526 struct list_head
*cur
;
530 if (!test_opt(sb
, MBALLOC
))
534 static int mb_check_counter
;
535 if (mb_check_counter
++ % 100 != 0)
540 buddy
= mb_find_buddy(e4b
, order
, &max
);
541 MB_CHECK_ASSERT(buddy
);
542 buddy2
= mb_find_buddy(e4b
, order
- 1, &max2
);
543 MB_CHECK_ASSERT(buddy2
);
544 MB_CHECK_ASSERT(buddy
!= buddy2
);
545 MB_CHECK_ASSERT(max
* 2 == max2
);
548 for (i
= 0; i
< max
; i
++) {
550 if (mb_test_bit(i
, buddy
)) {
551 /* only single bit in buddy2 may be 1 */
552 if (!mb_test_bit(i
<< 1, buddy2
)) {
554 mb_test_bit((i
<<1)+1, buddy2
));
555 } else if (!mb_test_bit((i
<< 1) + 1, buddy2
)) {
557 mb_test_bit(i
<< 1, buddy2
));
562 /* both bits in buddy2 must be 0 */
563 MB_CHECK_ASSERT(mb_test_bit(i
<< 1, buddy2
));
564 MB_CHECK_ASSERT(mb_test_bit((i
<< 1) + 1, buddy2
));
566 for (j
= 0; j
< (1 << order
); j
++) {
567 k
= (i
* (1 << order
)) + j
;
569 !mb_test_bit(k
, EXT4_MB_BITMAP(e4b
)));
573 MB_CHECK_ASSERT(e4b
->bd_info
->bb_counters
[order
] == count
);
578 buddy
= mb_find_buddy(e4b
, 0, &max
);
579 for (i
= 0; i
< max
; i
++) {
580 if (!mb_test_bit(i
, buddy
)) {
581 MB_CHECK_ASSERT(i
>= e4b
->bd_info
->bb_first_free
);
589 /* check used bits only */
590 for (j
= 0; j
< e4b
->bd_blkbits
+ 1; j
++) {
591 buddy2
= mb_find_buddy(e4b
, j
, &max2
);
593 MB_CHECK_ASSERT(k
< max2
);
594 MB_CHECK_ASSERT(mb_test_bit(k
, buddy2
));
597 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b
->bd_info
));
598 MB_CHECK_ASSERT(e4b
->bd_info
->bb_fragments
== fragments
);
600 grp
= ext4_get_group_info(sb
, e4b
->bd_group
);
601 buddy
= mb_find_buddy(e4b
, 0, &max
);
602 list_for_each(cur
, &grp
->bb_prealloc_list
) {
603 ext4_group_t groupnr
;
604 struct ext4_prealloc_space
*pa
;
605 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
606 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &groupnr
, &k
);
607 MB_CHECK_ASSERT(groupnr
== e4b
->bd_group
);
608 for (i
= 0; i
< pa
->pa_len
; i
++)
609 MB_CHECK_ASSERT(mb_test_bit(k
+ i
, buddy
));
613 #undef MB_CHECK_ASSERT
614 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
615 __FILE__, __func__, __LINE__)
617 #define mb_check_buddy(e4b)
620 /* FIXME!! need more doc */
621 static void ext4_mb_mark_free_simple(struct super_block
*sb
,
622 void *buddy
, unsigned first
, int len
,
623 struct ext4_group_info
*grp
)
625 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
628 unsigned short chunk
;
629 unsigned short border
;
631 BUG_ON(len
> EXT4_BLOCKS_PER_GROUP(sb
));
633 border
= 2 << sb
->s_blocksize_bits
;
636 /* find how many blocks can be covered since this position */
637 max
= ffs(first
| border
) - 1;
639 /* find how many blocks of power 2 we need to mark */
646 /* mark multiblock chunks only */
647 grp
->bb_counters
[min
]++;
649 mb_clear_bit(first
>> min
,
650 buddy
+ sbi
->s_mb_offsets
[min
]);
657 static void ext4_mb_generate_buddy(struct super_block
*sb
,
658 void *buddy
, void *bitmap
, ext4_group_t group
)
660 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
661 unsigned short max
= EXT4_BLOCKS_PER_GROUP(sb
);
662 unsigned short i
= 0;
663 unsigned short first
;
666 unsigned fragments
= 0;
667 unsigned long long period
= get_cycles();
669 /* initialize buddy from bitmap which is aggregation
670 * of on-disk bitmap and preallocations */
671 i
= mb_find_next_zero_bit(bitmap
, max
, 0);
672 grp
->bb_first_free
= i
;
676 i
= mb_find_next_bit(bitmap
, max
, i
);
680 ext4_mb_mark_free_simple(sb
, buddy
, first
, len
, grp
);
682 grp
->bb_counters
[0]++;
684 i
= mb_find_next_zero_bit(bitmap
, max
, i
);
686 grp
->bb_fragments
= fragments
;
688 if (free
!= grp
->bb_free
) {
689 ext4_error(sb
, __func__
,
690 "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
691 group
, free
, grp
->bb_free
);
693 * If we intent to continue, we consider group descritor
694 * corrupt and update bb_free using bitmap value
699 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
, &(grp
->bb_state
));
701 period
= get_cycles() - period
;
702 spin_lock(&EXT4_SB(sb
)->s_bal_lock
);
703 EXT4_SB(sb
)->s_mb_buddies_generated
++;
704 EXT4_SB(sb
)->s_mb_generation_time
+= period
;
705 spin_unlock(&EXT4_SB(sb
)->s_bal_lock
);
708 /* The buddy information is attached the buddy cache inode
709 * for convenience. The information regarding each group
710 * is loaded via ext4_mb_load_buddy. The information involve
711 * block bitmap and buddy information. The information are
712 * stored in the inode as
715 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
718 * one block each for bitmap and buddy information.
719 * So for each group we take up 2 blocks. A page can
720 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
721 * So it can have information regarding groups_per_page which
722 * is blocks_per_page/2
725 static int ext4_mb_init_cache(struct page
*page
, char *incore
)
732 ext4_group_t first_group
;
734 struct super_block
*sb
;
735 struct buffer_head
*bhs
;
736 struct buffer_head
**bh
;
741 mb_debug("init page %lu\n", page
->index
);
743 inode
= page
->mapping
->host
;
745 blocksize
= 1 << inode
->i_blkbits
;
746 blocks_per_page
= PAGE_CACHE_SIZE
/ blocksize
;
748 groups_per_page
= blocks_per_page
>> 1;
749 if (groups_per_page
== 0)
752 /* allocate buffer_heads to read bitmaps */
753 if (groups_per_page
> 1) {
755 i
= sizeof(struct buffer_head
*) * groups_per_page
;
756 bh
= kzalloc(i
, GFP_NOFS
);
762 first_group
= page
->index
* blocks_per_page
/ 2;
764 /* read all groups the page covers into the cache */
765 for (i
= 0; i
< groups_per_page
; i
++) {
766 struct ext4_group_desc
*desc
;
768 if (first_group
+ i
>= EXT4_SB(sb
)->s_groups_count
)
772 desc
= ext4_get_group_desc(sb
, first_group
+ i
, NULL
);
777 bh
[i
] = sb_getblk(sb
, ext4_block_bitmap(sb
, desc
));
781 if (bh_uptodate_or_lock(bh
[i
]))
784 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
785 ext4_init_block_bitmap(sb
, bh
[i
],
786 first_group
+ i
, desc
);
787 set_buffer_uptodate(bh
[i
]);
788 unlock_buffer(bh
[i
]);
792 bh
[i
]->b_end_io
= end_buffer_read_sync
;
793 submit_bh(READ
, bh
[i
]);
794 mb_debug("read bitmap for group %lu\n", first_group
+ i
);
797 /* wait for I/O completion */
798 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
799 wait_on_buffer(bh
[i
]);
802 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
803 if (!buffer_uptodate(bh
[i
]))
806 first_block
= page
->index
* blocks_per_page
;
807 for (i
= 0; i
< blocks_per_page
; i
++) {
809 struct ext4_group_info
*grinfo
;
811 group
= (first_block
+ i
) >> 1;
812 if (group
>= EXT4_SB(sb
)->s_groups_count
)
816 * data carry information regarding this
817 * particular group in the format specified
821 data
= page_address(page
) + (i
* blocksize
);
822 bitmap
= bh
[group
- first_group
]->b_data
;
825 * We place the buddy block and bitmap block
828 if ((first_block
+ i
) & 1) {
829 /* this is block of buddy */
830 BUG_ON(incore
== NULL
);
831 mb_debug("put buddy for group %u in page %lu/%x\n",
832 group
, page
->index
, i
* blocksize
);
833 memset(data
, 0xff, blocksize
);
834 grinfo
= ext4_get_group_info(sb
, group
);
835 grinfo
->bb_fragments
= 0;
836 memset(grinfo
->bb_counters
, 0,
837 sizeof(unsigned short)*(sb
->s_blocksize_bits
+2));
839 * incore got set to the group block bitmap below
841 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
844 /* this is block of bitmap */
845 BUG_ON(incore
!= NULL
);
846 mb_debug("put bitmap for group %u in page %lu/%x\n",
847 group
, page
->index
, i
* blocksize
);
849 /* see comments in ext4_mb_put_pa() */
850 ext4_lock_group(sb
, group
);
851 memcpy(data
, bitmap
, blocksize
);
853 /* mark all preallocated blks used in in-core bitmap */
854 ext4_mb_generate_from_pa(sb
, data
, group
);
855 ext4_unlock_group(sb
, group
);
857 /* set incore so that the buddy information can be
858 * generated using this
863 SetPageUptodate(page
);
867 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
875 static noinline_for_stack
int
876 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
877 struct ext4_buddy
*e4b
)
879 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
880 struct inode
*inode
= sbi
->s_buddy_cache
;
887 mb_debug("load group %lu\n", group
);
889 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
891 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
892 e4b
->bd_info
= ext4_get_group_info(sb
, group
);
894 e4b
->bd_group
= group
;
895 e4b
->bd_buddy_page
= NULL
;
896 e4b
->bd_bitmap_page
= NULL
;
899 * the buddy cache inode stores the block bitmap
900 * and buddy information in consecutive blocks.
901 * So for each group we need two blocks.
904 pnum
= block
/ blocks_per_page
;
905 poff
= block
% blocks_per_page
;
907 /* we could use find_or_create_page(), but it locks page
908 * what we'd like to avoid in fast path ... */
909 page
= find_get_page(inode
->i_mapping
, pnum
);
910 if (page
== NULL
|| !PageUptodate(page
)) {
912 page_cache_release(page
);
913 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
915 BUG_ON(page
->mapping
!= inode
->i_mapping
);
916 if (!PageUptodate(page
)) {
917 ext4_mb_init_cache(page
, NULL
);
918 mb_cmp_bitmaps(e4b
, page_address(page
) +
919 (poff
* sb
->s_blocksize
));
924 if (page
== NULL
|| !PageUptodate(page
))
926 e4b
->bd_bitmap_page
= page
;
927 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
928 mark_page_accessed(page
);
931 pnum
= block
/ blocks_per_page
;
932 poff
= block
% blocks_per_page
;
934 page
= find_get_page(inode
->i_mapping
, pnum
);
935 if (page
== NULL
|| !PageUptodate(page
)) {
937 page_cache_release(page
);
938 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
940 BUG_ON(page
->mapping
!= inode
->i_mapping
);
941 if (!PageUptodate(page
))
942 ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
947 if (page
== NULL
|| !PageUptodate(page
))
949 e4b
->bd_buddy_page
= page
;
950 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
951 mark_page_accessed(page
);
953 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
954 BUG_ON(e4b
->bd_buddy_page
== NULL
);
959 if (e4b
->bd_bitmap_page
)
960 page_cache_release(e4b
->bd_bitmap_page
);
961 if (e4b
->bd_buddy_page
)
962 page_cache_release(e4b
->bd_buddy_page
);
963 e4b
->bd_buddy
= NULL
;
964 e4b
->bd_bitmap
= NULL
;
968 static void ext4_mb_release_desc(struct ext4_buddy
*e4b
)
970 if (e4b
->bd_bitmap_page
)
971 page_cache_release(e4b
->bd_bitmap_page
);
972 if (e4b
->bd_buddy_page
)
973 page_cache_release(e4b
->bd_buddy_page
);
977 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
982 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
983 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
985 bb
= EXT4_MB_BUDDY(e4b
);
986 while (order
<= e4b
->bd_blkbits
+ 1) {
988 if (!mb_test_bit(block
, bb
)) {
989 /* this block is part of buddy of order 'order' */
992 bb
+= 1 << (e4b
->bd_blkbits
- order
);
998 static void mb_clear_bits(spinlock_t
*lock
, void *bm
, int cur
, int len
)
1004 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1005 /* fast path: clear whole word at once */
1006 addr
= bm
+ (cur
>> 3);
1011 mb_clear_bit_atomic(lock
, cur
, bm
);
1016 static void mb_set_bits(spinlock_t
*lock
, void *bm
, int cur
, int len
)
1022 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1023 /* fast path: set whole word at once */
1024 addr
= bm
+ (cur
>> 3);
1029 mb_set_bit_atomic(lock
, cur
, bm
);
1034 static int mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1035 int first
, int count
)
1042 struct super_block
*sb
= e4b
->bd_sb
;
1044 BUG_ON(first
+ count
> (sb
->s_blocksize
<< 3));
1045 BUG_ON(!ext4_is_group_locked(sb
, e4b
->bd_group
));
1046 mb_check_buddy(e4b
);
1047 mb_free_blocks_double(inode
, e4b
, first
, count
);
1049 e4b
->bd_info
->bb_free
+= count
;
1050 if (first
< e4b
->bd_info
->bb_first_free
)
1051 e4b
->bd_info
->bb_first_free
= first
;
1053 /* let's maintain fragments counter */
1055 block
= !mb_test_bit(first
- 1, EXT4_MB_BITMAP(e4b
));
1056 if (first
+ count
< EXT4_SB(sb
)->s_mb_maxs
[0])
1057 max
= !mb_test_bit(first
+ count
, EXT4_MB_BITMAP(e4b
));
1059 e4b
->bd_info
->bb_fragments
--;
1060 else if (!block
&& !max
)
1061 e4b
->bd_info
->bb_fragments
++;
1063 /* let's maintain buddy itself */
1064 while (count
-- > 0) {
1068 if (!mb_test_bit(block
, EXT4_MB_BITMAP(e4b
))) {
1069 ext4_fsblk_t blocknr
;
1070 blocknr
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
);
1073 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
1075 ext4_error(sb
, __func__
, "double-free of inode"
1076 " %lu's block %llu(bit %u in group %lu)\n",
1077 inode
? inode
->i_ino
: 0, blocknr
, block
,
1080 mb_clear_bit(block
, EXT4_MB_BITMAP(e4b
));
1081 e4b
->bd_info
->bb_counters
[order
]++;
1083 /* start of the buddy */
1084 buddy
= mb_find_buddy(e4b
, order
, &max
);
1088 if (mb_test_bit(block
, buddy
) ||
1089 mb_test_bit(block
+ 1, buddy
))
1092 /* both the buddies are free, try to coalesce them */
1093 buddy2
= mb_find_buddy(e4b
, order
+ 1, &max
);
1099 /* for special purposes, we don't set
1100 * free bits in bitmap */
1101 mb_set_bit(block
, buddy
);
1102 mb_set_bit(block
+ 1, buddy
);
1104 e4b
->bd_info
->bb_counters
[order
]--;
1105 e4b
->bd_info
->bb_counters
[order
]--;
1109 e4b
->bd_info
->bb_counters
[order
]++;
1111 mb_clear_bit(block
, buddy2
);
1115 mb_check_buddy(e4b
);
1120 static int mb_find_extent(struct ext4_buddy
*e4b
, int order
, int block
,
1121 int needed
, struct ext4_free_extent
*ex
)
1128 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
1131 buddy
= mb_find_buddy(e4b
, order
, &max
);
1132 BUG_ON(buddy
== NULL
);
1133 BUG_ON(block
>= max
);
1134 if (mb_test_bit(block
, buddy
)) {
1141 /* FIXME dorp order completely ? */
1142 if (likely(order
== 0)) {
1143 /* find actual order */
1144 order
= mb_find_order_for_block(e4b
, block
);
1145 block
= block
>> order
;
1148 ex
->fe_len
= 1 << order
;
1149 ex
->fe_start
= block
<< order
;
1150 ex
->fe_group
= e4b
->bd_group
;
1152 /* calc difference from given start */
1153 next
= next
- ex
->fe_start
;
1155 ex
->fe_start
+= next
;
1157 while (needed
> ex
->fe_len
&&
1158 (buddy
= mb_find_buddy(e4b
, order
, &max
))) {
1160 if (block
+ 1 >= max
)
1163 next
= (block
+ 1) * (1 << order
);
1164 if (mb_test_bit(next
, EXT4_MB_BITMAP(e4b
)))
1167 ord
= mb_find_order_for_block(e4b
, next
);
1170 block
= next
>> order
;
1171 ex
->fe_len
+= 1 << order
;
1174 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1178 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1184 int start
= ex
->fe_start
;
1185 int len
= ex
->fe_len
;
1190 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1191 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1192 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
1193 mb_check_buddy(e4b
);
1194 mb_mark_used_double(e4b
, start
, len
);
1196 e4b
->bd_info
->bb_free
-= len
;
1197 if (e4b
->bd_info
->bb_first_free
== start
)
1198 e4b
->bd_info
->bb_first_free
+= len
;
1200 /* let's maintain fragments counter */
1202 mlen
= !mb_test_bit(start
- 1, EXT4_MB_BITMAP(e4b
));
1203 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1204 max
= !mb_test_bit(start
+ len
, EXT4_MB_BITMAP(e4b
));
1206 e4b
->bd_info
->bb_fragments
++;
1207 else if (!mlen
&& !max
)
1208 e4b
->bd_info
->bb_fragments
--;
1210 /* let's maintain buddy itself */
1212 ord
= mb_find_order_for_block(e4b
, start
);
1214 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1215 /* the whole chunk may be allocated at once! */
1217 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1218 BUG_ON((start
>> ord
) >= max
);
1219 mb_set_bit(start
>> ord
, buddy
);
1220 e4b
->bd_info
->bb_counters
[ord
]--;
1227 /* store for history */
1229 ret
= len
| (ord
<< 16);
1231 /* we have to split large buddy */
1233 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1234 mb_set_bit(start
>> ord
, buddy
);
1235 e4b
->bd_info
->bb_counters
[ord
]--;
1238 cur
= (start
>> ord
) & ~1U;
1239 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1240 mb_clear_bit(cur
, buddy
);
1241 mb_clear_bit(cur
+ 1, buddy
);
1242 e4b
->bd_info
->bb_counters
[ord
]++;
1243 e4b
->bd_info
->bb_counters
[ord
]++;
1246 mb_set_bits(sb_bgl_lock(EXT4_SB(e4b
->bd_sb
), ex
->fe_group
),
1247 EXT4_MB_BITMAP(e4b
), ex
->fe_start
, len0
);
1248 mb_check_buddy(e4b
);
1254 * Must be called under group lock!
1256 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1257 struct ext4_buddy
*e4b
)
1259 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1262 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1263 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1265 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1266 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1267 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1269 /* preallocation can change ac_b_ex, thus we store actually
1270 * allocated blocks for history */
1271 ac
->ac_f_ex
= ac
->ac_b_ex
;
1273 ac
->ac_status
= AC_STATUS_FOUND
;
1274 ac
->ac_tail
= ret
& 0xffff;
1275 ac
->ac_buddy
= ret
>> 16;
1277 /* XXXXXXX: SUCH A HORRIBLE **CK */
1279 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1280 get_page(ac
->ac_bitmap_page
);
1281 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1282 get_page(ac
->ac_buddy_page
);
1284 /* store last allocated for subsequent stream allocation */
1285 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
)) {
1286 spin_lock(&sbi
->s_md_lock
);
1287 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1288 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1289 spin_unlock(&sbi
->s_md_lock
);
1294 * regular allocator, for general purposes allocation
1297 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1298 struct ext4_buddy
*e4b
,
1301 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1302 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1303 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1304 struct ext4_free_extent ex
;
1308 * We don't want to scan for a whole year
1310 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1311 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1312 ac
->ac_status
= AC_STATUS_BREAK
;
1317 * Haven't found good chunk so far, let's continue
1319 if (bex
->fe_len
< gex
->fe_len
)
1322 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1323 && bex
->fe_group
== e4b
->bd_group
) {
1324 /* recheck chunk's availability - we don't know
1325 * when it was found (within this lock-unlock
1327 max
= mb_find_extent(e4b
, 0, bex
->fe_start
, gex
->fe_len
, &ex
);
1328 if (max
>= gex
->fe_len
) {
1329 ext4_mb_use_best_found(ac
, e4b
);
1336 * The routine checks whether found extent is good enough. If it is,
1337 * then the extent gets marked used and flag is set to the context
1338 * to stop scanning. Otherwise, the extent is compared with the
1339 * previous found extent and if new one is better, then it's stored
1340 * in the context. Later, the best found extent will be used, if
1341 * mballoc can't find good enough extent.
1343 * FIXME: real allocation policy is to be designed yet!
1345 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1346 struct ext4_free_extent
*ex
,
1347 struct ext4_buddy
*e4b
)
1349 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1350 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1352 BUG_ON(ex
->fe_len
<= 0);
1353 BUG_ON(ex
->fe_len
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1354 BUG_ON(ex
->fe_start
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1355 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1360 * The special case - take what you catch first
1362 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1364 ext4_mb_use_best_found(ac
, e4b
);
1369 * Let's check whether the chuck is good enough
1371 if (ex
->fe_len
== gex
->fe_len
) {
1373 ext4_mb_use_best_found(ac
, e4b
);
1378 * If this is first found extent, just store it in the context
1380 if (bex
->fe_len
== 0) {
1386 * If new found extent is better, store it in the context
1388 if (bex
->fe_len
< gex
->fe_len
) {
1389 /* if the request isn't satisfied, any found extent
1390 * larger than previous best one is better */
1391 if (ex
->fe_len
> bex
->fe_len
)
1393 } else if (ex
->fe_len
> gex
->fe_len
) {
1394 /* if the request is satisfied, then we try to find
1395 * an extent that still satisfy the request, but is
1396 * smaller than previous one */
1397 if (ex
->fe_len
< bex
->fe_len
)
1401 ext4_mb_check_limits(ac
, e4b
, 0);
1404 static int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1405 struct ext4_buddy
*e4b
)
1407 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1408 ext4_group_t group
= ex
.fe_group
;
1412 BUG_ON(ex
.fe_len
<= 0);
1413 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1417 ext4_lock_group(ac
->ac_sb
, group
);
1418 max
= mb_find_extent(e4b
, 0, ex
.fe_start
, ex
.fe_len
, &ex
);
1422 ext4_mb_use_best_found(ac
, e4b
);
1425 ext4_unlock_group(ac
->ac_sb
, group
);
1426 ext4_mb_release_desc(e4b
);
1431 static int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1432 struct ext4_buddy
*e4b
)
1434 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1437 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1438 struct ext4_super_block
*es
= sbi
->s_es
;
1439 struct ext4_free_extent ex
;
1441 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1444 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1448 ext4_lock_group(ac
->ac_sb
, group
);
1449 max
= mb_find_extent(e4b
, 0, ac
->ac_g_ex
.fe_start
,
1450 ac
->ac_g_ex
.fe_len
, &ex
);
1452 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1455 start
= (e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
)) +
1456 ex
.fe_start
+ le32_to_cpu(es
->s_first_data_block
);
1457 /* use do_div to get remainder (would be 64-bit modulo) */
1458 if (do_div(start
, sbi
->s_stripe
) == 0) {
1461 ext4_mb_use_best_found(ac
, e4b
);
1463 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1464 BUG_ON(ex
.fe_len
<= 0);
1465 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1466 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1469 ext4_mb_use_best_found(ac
, e4b
);
1470 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1471 /* Sometimes, caller may want to merge even small
1472 * number of blocks to an existing extent */
1473 BUG_ON(ex
.fe_len
<= 0);
1474 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1475 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1478 ext4_mb_use_best_found(ac
, e4b
);
1480 ext4_unlock_group(ac
->ac_sb
, group
);
1481 ext4_mb_release_desc(e4b
);
1487 * The routine scans buddy structures (not bitmap!) from given order
1488 * to max order and tries to find big enough chunk to satisfy the req
1490 static void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1491 struct ext4_buddy
*e4b
)
1493 struct super_block
*sb
= ac
->ac_sb
;
1494 struct ext4_group_info
*grp
= e4b
->bd_info
;
1500 BUG_ON(ac
->ac_2order
<= 0);
1501 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1502 if (grp
->bb_counters
[i
] == 0)
1505 buddy
= mb_find_buddy(e4b
, i
, &max
);
1506 BUG_ON(buddy
== NULL
);
1508 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1513 ac
->ac_b_ex
.fe_len
= 1 << i
;
1514 ac
->ac_b_ex
.fe_start
= k
<< i
;
1515 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1517 ext4_mb_use_best_found(ac
, e4b
);
1519 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1521 if (EXT4_SB(sb
)->s_mb_stats
)
1522 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1529 * The routine scans the group and measures all found extents.
1530 * In order to optimize scanning, caller must pass number of
1531 * free blocks in the group, so the routine can know upper limit.
1533 static void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1534 struct ext4_buddy
*e4b
)
1536 struct super_block
*sb
= ac
->ac_sb
;
1537 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1538 struct ext4_free_extent ex
;
1542 free
= e4b
->bd_info
->bb_free
;
1545 i
= e4b
->bd_info
->bb_first_free
;
1547 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1548 i
= mb_find_next_zero_bit(bitmap
,
1549 EXT4_BLOCKS_PER_GROUP(sb
), i
);
1550 if (i
>= EXT4_BLOCKS_PER_GROUP(sb
)) {
1552 * IF we have corrupt bitmap, we won't find any
1553 * free blocks even though group info says we
1554 * we have free blocks
1556 ext4_error(sb
, __func__
, "%d free blocks as per "
1557 "group info. But bitmap says 0\n",
1562 mb_find_extent(e4b
, 0, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1563 BUG_ON(ex
.fe_len
<= 0);
1564 if (free
< ex
.fe_len
) {
1565 ext4_error(sb
, __func__
, "%d free blocks as per "
1566 "group info. But got %d blocks\n",
1569 * The number of free blocks differs. This mostly
1570 * indicate that the bitmap is corrupt. So exit
1571 * without claiming the space.
1576 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1582 ext4_mb_check_limits(ac
, e4b
, 1);
1586 * This is a special case for storages like raid5
1587 * we try to find stripe-aligned chunks for stripe-size requests
1588 * XXX should do so at least for multiples of stripe size as well
1590 static void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1591 struct ext4_buddy
*e4b
)
1593 struct super_block
*sb
= ac
->ac_sb
;
1594 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1595 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1596 struct ext4_free_extent ex
;
1597 ext4_fsblk_t first_group_block
;
1602 BUG_ON(sbi
->s_stripe
== 0);
1604 /* find first stripe-aligned block in group */
1605 first_group_block
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
)
1606 + le32_to_cpu(sbi
->s_es
->s_first_data_block
);
1607 a
= first_group_block
+ sbi
->s_stripe
- 1;
1608 do_div(a
, sbi
->s_stripe
);
1609 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1611 while (i
< EXT4_BLOCKS_PER_GROUP(sb
)) {
1612 if (!mb_test_bit(i
, bitmap
)) {
1613 max
= mb_find_extent(e4b
, 0, i
, sbi
->s_stripe
, &ex
);
1614 if (max
>= sbi
->s_stripe
) {
1617 ext4_mb_use_best_found(ac
, e4b
);
1625 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
1626 ext4_group_t group
, int cr
)
1628 unsigned free
, fragments
;
1630 struct ext4_group_desc
*desc
;
1631 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1633 BUG_ON(cr
< 0 || cr
>= 4);
1634 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp
));
1636 free
= grp
->bb_free
;
1637 fragments
= grp
->bb_fragments
;
1645 BUG_ON(ac
->ac_2order
== 0);
1646 /* If this group is uninitialized, skip it initially */
1647 desc
= ext4_get_group_desc(ac
->ac_sb
, group
, NULL
);
1648 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
))
1651 bits
= ac
->ac_sb
->s_blocksize_bits
+ 1;
1652 for (i
= ac
->ac_2order
; i
<= bits
; i
++)
1653 if (grp
->bb_counters
[i
] > 0)
1657 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
1661 if (free
>= ac
->ac_g_ex
.fe_len
)
1673 static noinline_for_stack
int
1674 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
1681 struct ext4_sb_info
*sbi
;
1682 struct super_block
*sb
;
1683 struct ext4_buddy e4b
;
1688 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1690 /* first, try the goal */
1691 err
= ext4_mb_find_by_goal(ac
, &e4b
);
1692 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
1695 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
1699 * ac->ac2_order is set only if the fe_len is a power of 2
1700 * if ac2_order is set we also set criteria to 0 so that we
1701 * try exact allocation using buddy.
1703 i
= fls(ac
->ac_g_ex
.fe_len
);
1706 * We search using buddy data only if the order of the request
1707 * is greater than equal to the sbi_s_mb_order2_reqs
1708 * You can tune it via /proc/fs/ext4/<partition>/order2_req
1710 if (i
>= sbi
->s_mb_order2_reqs
) {
1712 * This should tell if fe_len is exactly power of 2
1714 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
1715 ac
->ac_2order
= i
- 1;
1718 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
1719 /* if stream allocation is enabled, use global goal */
1720 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
1721 isize
= i_size_read(ac
->ac_inode
) >> bsbits
;
1725 if (size
< sbi
->s_mb_stream_request
&&
1726 (ac
->ac_flags
& EXT4_MB_HINT_DATA
)) {
1727 /* TBD: may be hot point */
1728 spin_lock(&sbi
->s_md_lock
);
1729 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
1730 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
1731 spin_unlock(&sbi
->s_md_lock
);
1734 /* searching for the right group start from the goal value specified */
1735 group
= ac
->ac_g_ex
.fe_group
;
1737 /* Let's just scan groups to find more-less suitable blocks */
1738 cr
= ac
->ac_2order
? 0 : 1;
1740 * cr == 0 try to get exact allocation,
1741 * cr == 3 try to get anything
1744 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
1745 ac
->ac_criteria
= cr
;
1746 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
; group
++, i
++) {
1747 struct ext4_group_info
*grp
;
1748 struct ext4_group_desc
*desc
;
1750 if (group
== EXT4_SB(sb
)->s_groups_count
)
1753 /* quick check to skip empty groups */
1754 grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1755 if (grp
->bb_free
== 0)
1759 * if the group is already init we check whether it is
1760 * a good group and if not we don't load the buddy
1762 if (EXT4_MB_GRP_NEED_INIT(grp
)) {
1764 * we need full data about the group
1765 * to make a good selection
1767 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
1770 ext4_mb_release_desc(&e4b
);
1774 * If the particular group doesn't satisfy our
1775 * criteria we continue with the next group
1777 if (!ext4_mb_good_group(ac
, group
, cr
))
1780 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
1784 ext4_lock_group(sb
, group
);
1785 if (!ext4_mb_good_group(ac
, group
, cr
)) {
1786 /* someone did allocation from this group */
1787 ext4_unlock_group(sb
, group
);
1788 ext4_mb_release_desc(&e4b
);
1792 ac
->ac_groups_scanned
++;
1793 desc
= ext4_get_group_desc(sb
, group
, NULL
);
1794 if (cr
== 0 || (desc
->bg_flags
&
1795 cpu_to_le16(EXT4_BG_BLOCK_UNINIT
) &&
1796 ac
->ac_2order
!= 0))
1797 ext4_mb_simple_scan_group(ac
, &e4b
);
1799 ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
)
1800 ext4_mb_scan_aligned(ac
, &e4b
);
1802 ext4_mb_complex_scan_group(ac
, &e4b
);
1804 ext4_unlock_group(sb
, group
);
1805 ext4_mb_release_desc(&e4b
);
1807 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
1812 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
1813 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1815 * We've been searching too long. Let's try to allocate
1816 * the best chunk we've found so far
1819 ext4_mb_try_best_found(ac
, &e4b
);
1820 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
1822 * Someone more lucky has already allocated it.
1823 * The only thing we can do is just take first
1825 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
1827 ac
->ac_b_ex
.fe_group
= 0;
1828 ac
->ac_b_ex
.fe_start
= 0;
1829 ac
->ac_b_ex
.fe_len
= 0;
1830 ac
->ac_status
= AC_STATUS_CONTINUE
;
1831 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
1833 atomic_inc(&sbi
->s_mb_lost_chunks
);
1841 #ifdef EXT4_MB_HISTORY
1842 struct ext4_mb_proc_session
{
1843 struct ext4_mb_history
*history
;
1844 struct super_block
*sb
;
1849 static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session
*s
,
1850 struct ext4_mb_history
*hs
,
1853 if (hs
== s
->history
+ s
->max
)
1855 if (!first
&& hs
== s
->history
+ s
->start
)
1857 while (hs
->orig
.fe_len
== 0) {
1859 if (hs
== s
->history
+ s
->max
)
1861 if (hs
== s
->history
+ s
->start
)
1867 static void *ext4_mb_seq_history_start(struct seq_file
*seq
, loff_t
*pos
)
1869 struct ext4_mb_proc_session
*s
= seq
->private;
1870 struct ext4_mb_history
*hs
;
1874 return SEQ_START_TOKEN
;
1875 hs
= ext4_mb_history_skip_empty(s
, s
->history
+ s
->start
, 1);
1878 while (--l
&& (hs
= ext4_mb_history_skip_empty(s
, ++hs
, 0)) != NULL
);
1882 static void *ext4_mb_seq_history_next(struct seq_file
*seq
, void *v
,
1885 struct ext4_mb_proc_session
*s
= seq
->private;
1886 struct ext4_mb_history
*hs
= v
;
1889 if (v
== SEQ_START_TOKEN
)
1890 return ext4_mb_history_skip_empty(s
, s
->history
+ s
->start
, 1);
1892 return ext4_mb_history_skip_empty(s
, ++hs
, 0);
1895 static int ext4_mb_seq_history_show(struct seq_file
*seq
, void *v
)
1897 char buf
[25], buf2
[25], buf3
[25], *fmt
;
1898 struct ext4_mb_history
*hs
= v
;
1900 if (v
== SEQ_START_TOKEN
) {
1901 seq_printf(seq
, "%-5s %-8s %-23s %-23s %-23s %-5s "
1902 "%-5s %-2s %-5s %-5s %-5s %-6s\n",
1903 "pid", "inode", "original", "goal", "result", "found",
1904 "grps", "cr", "flags", "merge", "tail", "broken");
1908 if (hs
->op
== EXT4_MB_HISTORY_ALLOC
) {
1909 fmt
= "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
1910 "%-5u %-5s %-5u %-6u\n";
1911 sprintf(buf2
, "%lu/%d/%u@%u", hs
->result
.fe_group
,
1912 hs
->result
.fe_start
, hs
->result
.fe_len
,
1913 hs
->result
.fe_logical
);
1914 sprintf(buf
, "%lu/%d/%u@%u", hs
->orig
.fe_group
,
1915 hs
->orig
.fe_start
, hs
->orig
.fe_len
,
1916 hs
->orig
.fe_logical
);
1917 sprintf(buf3
, "%lu/%d/%u@%u", hs
->goal
.fe_group
,
1918 hs
->goal
.fe_start
, hs
->goal
.fe_len
,
1919 hs
->goal
.fe_logical
);
1920 seq_printf(seq
, fmt
, hs
->pid
, hs
->ino
, buf
, buf3
, buf2
,
1921 hs
->found
, hs
->groups
, hs
->cr
, hs
->flags
,
1922 hs
->merged
? "M" : "", hs
->tail
,
1923 hs
->buddy
? 1 << hs
->buddy
: 0);
1924 } else if (hs
->op
== EXT4_MB_HISTORY_PREALLOC
) {
1925 fmt
= "%-5u %-8u %-23s %-23s %-23s\n";
1926 sprintf(buf2
, "%lu/%d/%u@%u", hs
->result
.fe_group
,
1927 hs
->result
.fe_start
, hs
->result
.fe_len
,
1928 hs
->result
.fe_logical
);
1929 sprintf(buf
, "%lu/%d/%u@%u", hs
->orig
.fe_group
,
1930 hs
->orig
.fe_start
, hs
->orig
.fe_len
,
1931 hs
->orig
.fe_logical
);
1932 seq_printf(seq
, fmt
, hs
->pid
, hs
->ino
, buf
, "", buf2
);
1933 } else if (hs
->op
== EXT4_MB_HISTORY_DISCARD
) {
1934 sprintf(buf2
, "%lu/%d/%u", hs
->result
.fe_group
,
1935 hs
->result
.fe_start
, hs
->result
.fe_len
);
1936 seq_printf(seq
, "%-5u %-8u %-23s discard\n",
1937 hs
->pid
, hs
->ino
, buf2
);
1938 } else if (hs
->op
== EXT4_MB_HISTORY_FREE
) {
1939 sprintf(buf2
, "%lu/%d/%u", hs
->result
.fe_group
,
1940 hs
->result
.fe_start
, hs
->result
.fe_len
);
1941 seq_printf(seq
, "%-5u %-8u %-23s free\n",
1942 hs
->pid
, hs
->ino
, buf2
);
1947 static void ext4_mb_seq_history_stop(struct seq_file
*seq
, void *v
)
1951 static struct seq_operations ext4_mb_seq_history_ops
= {
1952 .start
= ext4_mb_seq_history_start
,
1953 .next
= ext4_mb_seq_history_next
,
1954 .stop
= ext4_mb_seq_history_stop
,
1955 .show
= ext4_mb_seq_history_show
,
1958 static int ext4_mb_seq_history_open(struct inode
*inode
, struct file
*file
)
1960 struct super_block
*sb
= PDE(inode
)->data
;
1961 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1962 struct ext4_mb_proc_session
*s
;
1966 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1970 size
= sizeof(struct ext4_mb_history
) * sbi
->s_mb_history_max
;
1971 s
->history
= kmalloc(size
, GFP_KERNEL
);
1972 if (s
->history
== NULL
) {
1977 spin_lock(&sbi
->s_mb_history_lock
);
1978 memcpy(s
->history
, sbi
->s_mb_history
, size
);
1979 s
->max
= sbi
->s_mb_history_max
;
1980 s
->start
= sbi
->s_mb_history_cur
% s
->max
;
1981 spin_unlock(&sbi
->s_mb_history_lock
);
1983 rc
= seq_open(file
, &ext4_mb_seq_history_ops
);
1985 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
1995 static int ext4_mb_seq_history_release(struct inode
*inode
, struct file
*file
)
1997 struct seq_file
*seq
= (struct seq_file
*)file
->private_data
;
1998 struct ext4_mb_proc_session
*s
= seq
->private;
2001 return seq_release(inode
, file
);
2004 static ssize_t
ext4_mb_seq_history_write(struct file
*file
,
2005 const char __user
*buffer
,
2006 size_t count
, loff_t
*ppos
)
2008 struct seq_file
*seq
= (struct seq_file
*)file
->private_data
;
2009 struct ext4_mb_proc_session
*s
= seq
->private;
2010 struct super_block
*sb
= s
->sb
;
2014 if (count
>= sizeof(str
)) {
2015 printk(KERN_ERR
"EXT4-fs: %s string too long, max %u bytes\n",
2016 "mb_history", (int)sizeof(str
));
2020 if (copy_from_user(str
, buffer
, count
))
2023 value
= simple_strtol(str
, NULL
, 0);
2026 EXT4_SB(sb
)->s_mb_history_filter
= value
;
2031 static struct file_operations ext4_mb_seq_history_fops
= {
2032 .owner
= THIS_MODULE
,
2033 .open
= ext4_mb_seq_history_open
,
2035 .write
= ext4_mb_seq_history_write
,
2036 .llseek
= seq_lseek
,
2037 .release
= ext4_mb_seq_history_release
,
2040 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2042 struct super_block
*sb
= seq
->private;
2043 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2046 if (*pos
< 0 || *pos
>= sbi
->s_groups_count
)
2050 return (void *) group
;
2053 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2055 struct super_block
*sb
= seq
->private;
2056 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2060 if (*pos
< 0 || *pos
>= sbi
->s_groups_count
)
2063 return (void *) group
;;
2066 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2068 struct super_block
*sb
= seq
->private;
2069 long group
= (long) v
;
2072 struct ext4_buddy e4b
;
2074 struct ext4_group_info info
;
2075 unsigned short counters
[16];
2080 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2081 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2082 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2083 "group", "free", "frags", "first",
2084 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2085 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2087 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2088 sizeof(struct ext4_group_info
);
2089 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2091 seq_printf(seq
, "#%-5lu: I/O error\n", group
);
2094 ext4_lock_group(sb
, group
);
2095 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2096 ext4_unlock_group(sb
, group
);
2097 ext4_mb_release_desc(&e4b
);
2099 seq_printf(seq
, "#%-5lu: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2100 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2101 for (i
= 0; i
<= 13; i
++)
2102 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2103 sg
.info
.bb_counters
[i
] : 0);
2104 seq_printf(seq
, " ]\n");
2109 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2113 static struct seq_operations ext4_mb_seq_groups_ops
= {
2114 .start
= ext4_mb_seq_groups_start
,
2115 .next
= ext4_mb_seq_groups_next
,
2116 .stop
= ext4_mb_seq_groups_stop
,
2117 .show
= ext4_mb_seq_groups_show
,
2120 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2122 struct super_block
*sb
= PDE(inode
)->data
;
2125 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2127 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2134 static struct file_operations ext4_mb_seq_groups_fops
= {
2135 .owner
= THIS_MODULE
,
2136 .open
= ext4_mb_seq_groups_open
,
2138 .llseek
= seq_lseek
,
2139 .release
= seq_release
,
2142 static void ext4_mb_history_release(struct super_block
*sb
)
2144 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2146 remove_proc_entry("mb_groups", sbi
->s_mb_proc
);
2147 remove_proc_entry("mb_history", sbi
->s_mb_proc
);
2149 kfree(sbi
->s_mb_history
);
2152 static void ext4_mb_history_init(struct super_block
*sb
)
2154 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2157 if (sbi
->s_mb_proc
!= NULL
) {
2158 proc_create_data("mb_history", S_IRUGO
, sbi
->s_mb_proc
,
2159 &ext4_mb_seq_history_fops
, sb
);
2160 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_mb_proc
,
2161 &ext4_mb_seq_groups_fops
, sb
);
2164 sbi
->s_mb_history_max
= 1000;
2165 sbi
->s_mb_history_cur
= 0;
2166 spin_lock_init(&sbi
->s_mb_history_lock
);
2167 i
= sbi
->s_mb_history_max
* sizeof(struct ext4_mb_history
);
2168 sbi
->s_mb_history
= kmalloc(i
, GFP_KERNEL
);
2169 if (likely(sbi
->s_mb_history
!= NULL
))
2170 memset(sbi
->s_mb_history
, 0, i
);
2171 /* if we can't allocate history, then we simple won't use it */
2174 static noinline_for_stack
void
2175 ext4_mb_store_history(struct ext4_allocation_context
*ac
)
2177 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
2178 struct ext4_mb_history h
;
2180 if (unlikely(sbi
->s_mb_history
== NULL
))
2183 if (!(ac
->ac_op
& sbi
->s_mb_history_filter
))
2187 h
.pid
= current
->pid
;
2188 h
.ino
= ac
->ac_inode
? ac
->ac_inode
->i_ino
: 0;
2189 h
.orig
= ac
->ac_o_ex
;
2190 h
.result
= ac
->ac_b_ex
;
2191 h
.flags
= ac
->ac_flags
;
2192 h
.found
= ac
->ac_found
;
2193 h
.groups
= ac
->ac_groups_scanned
;
2194 h
.cr
= ac
->ac_criteria
;
2195 h
.tail
= ac
->ac_tail
;
2196 h
.buddy
= ac
->ac_buddy
;
2198 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
) {
2199 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
2200 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
2202 h
.goal
= ac
->ac_g_ex
;
2203 h
.result
= ac
->ac_f_ex
;
2206 spin_lock(&sbi
->s_mb_history_lock
);
2207 memcpy(sbi
->s_mb_history
+ sbi
->s_mb_history_cur
, &h
, sizeof(h
));
2208 if (++sbi
->s_mb_history_cur
>= sbi
->s_mb_history_max
)
2209 sbi
->s_mb_history_cur
= 0;
2210 spin_unlock(&sbi
->s_mb_history_lock
);
2214 #define ext4_mb_history_release(sb)
2215 #define ext4_mb_history_init(sb)
2218 static int ext4_mb_init_backend(struct super_block
*sb
)
2221 int j
, len
, metalen
;
2222 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2223 int num_meta_group_infos
=
2224 (sbi
->s_groups_count
+ EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2225 EXT4_DESC_PER_BLOCK_BITS(sb
);
2226 struct ext4_group_info
**meta_group_info
;
2228 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2229 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2230 * So a two level scheme suffices for now. */
2231 sbi
->s_group_info
= kmalloc(sizeof(*sbi
->s_group_info
) *
2232 num_meta_group_infos
, GFP_KERNEL
);
2233 if (sbi
->s_group_info
== NULL
) {
2234 printk(KERN_ERR
"EXT4-fs: can't allocate buddy meta group\n");
2237 sbi
->s_buddy_cache
= new_inode(sb
);
2238 if (sbi
->s_buddy_cache
== NULL
) {
2239 printk(KERN_ERR
"EXT4-fs: can't get new inode\n");
2242 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2244 metalen
= sizeof(*meta_group_info
) << EXT4_DESC_PER_BLOCK_BITS(sb
);
2245 for (i
= 0; i
< num_meta_group_infos
; i
++) {
2246 if ((i
+ 1) == num_meta_group_infos
)
2247 metalen
= sizeof(*meta_group_info
) *
2248 (sbi
->s_groups_count
-
2249 (i
<< EXT4_DESC_PER_BLOCK_BITS(sb
)));
2250 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2251 if (meta_group_info
== NULL
) {
2252 printk(KERN_ERR
"EXT4-fs: can't allocate mem for a "
2256 sbi
->s_group_info
[i
] = meta_group_info
;
2260 * calculate needed size. if change bb_counters size,
2261 * don't forget about ext4_mb_generate_buddy()
2263 len
= sizeof(struct ext4_group_info
);
2264 len
+= sizeof(unsigned short) * (sb
->s_blocksize_bits
+ 2);
2265 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
2266 struct ext4_group_desc
*desc
;
2269 sbi
->s_group_info
[i
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2270 j
= i
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2272 meta_group_info
[j
] = kzalloc(len
, GFP_KERNEL
);
2273 if (meta_group_info
[j
] == NULL
) {
2274 printk(KERN_ERR
"EXT4-fs: can't allocate buddy mem\n");
2277 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2280 "EXT4-fs: can't read descriptor %lu\n", i
);
2284 memset(meta_group_info
[j
], 0, len
);
2285 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2286 &(meta_group_info
[j
]->bb_state
));
2289 * initialize bb_free to be able to skip
2290 * empty groups without initialization
2292 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2293 meta_group_info
[j
]->bb_free
=
2294 ext4_free_blocks_after_init(sb
, i
, desc
);
2296 meta_group_info
[j
]->bb_free
=
2297 le16_to_cpu(desc
->bg_free_blocks_count
);
2300 INIT_LIST_HEAD(&meta_group_info
[j
]->bb_prealloc_list
);
2304 struct buffer_head
*bh
;
2305 meta_group_info
[j
]->bb_bitmap
=
2306 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2307 BUG_ON(meta_group_info
[j
]->bb_bitmap
== NULL
);
2308 bh
= read_block_bitmap(sb
, i
);
2310 memcpy(meta_group_info
[j
]->bb_bitmap
, bh
->b_data
,
2322 kfree(ext4_get_group_info(sb
, i
));
2323 i
= num_meta_group_infos
;
2326 kfree(sbi
->s_group_info
[i
]);
2327 iput(sbi
->s_buddy_cache
);
2329 kfree(sbi
->s_group_info
);
2333 int ext4_mb_init(struct super_block
*sb
, int needs_recovery
)
2335 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2340 if (!test_opt(sb
, MBALLOC
))
2343 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(unsigned short);
2345 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2346 if (sbi
->s_mb_offsets
== NULL
) {
2347 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2350 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2351 if (sbi
->s_mb_maxs
== NULL
) {
2352 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2353 kfree(sbi
->s_mb_maxs
);
2357 /* order 0 is regular bitmap */
2358 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2359 sbi
->s_mb_offsets
[0] = 0;
2363 max
= sb
->s_blocksize
<< 2;
2365 sbi
->s_mb_offsets
[i
] = offset
;
2366 sbi
->s_mb_maxs
[i
] = max
;
2367 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2370 } while (i
<= sb
->s_blocksize_bits
+ 1);
2372 /* init file for buddy data */
2373 i
= ext4_mb_init_backend(sb
);
2375 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2376 kfree(sbi
->s_mb_offsets
);
2377 kfree(sbi
->s_mb_maxs
);
2381 spin_lock_init(&sbi
->s_md_lock
);
2382 INIT_LIST_HEAD(&sbi
->s_active_transaction
);
2383 INIT_LIST_HEAD(&sbi
->s_closed_transaction
);
2384 INIT_LIST_HEAD(&sbi
->s_committed_transaction
);
2385 spin_lock_init(&sbi
->s_bal_lock
);
2387 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2388 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2389 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2390 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2391 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2392 sbi
->s_mb_history_filter
= EXT4_MB_HISTORY_DEFAULT
;
2393 sbi
->s_mb_group_prealloc
= MB_DEFAULT_GROUP_PREALLOC
;
2395 i
= sizeof(struct ext4_locality_group
) * NR_CPUS
;
2396 sbi
->s_locality_groups
= kmalloc(i
, GFP_KERNEL
);
2397 if (sbi
->s_locality_groups
== NULL
) {
2398 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2399 kfree(sbi
->s_mb_offsets
);
2400 kfree(sbi
->s_mb_maxs
);
2403 for (i
= 0; i
< NR_CPUS
; i
++) {
2404 struct ext4_locality_group
*lg
;
2405 lg
= &sbi
->s_locality_groups
[i
];
2406 mutex_init(&lg
->lg_mutex
);
2407 INIT_LIST_HEAD(&lg
->lg_prealloc_list
);
2408 spin_lock_init(&lg
->lg_prealloc_lock
);
2411 ext4_mb_init_per_dev_proc(sb
);
2412 ext4_mb_history_init(sb
);
2414 printk("EXT4-fs: mballoc enabled\n");
2418 /* need to called with ext4 group lock (ext4_lock_group) */
2419 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2421 struct ext4_prealloc_space
*pa
;
2422 struct list_head
*cur
, *tmp
;
2425 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2426 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2427 list_del(&pa
->pa_group_list
);
2432 mb_debug("mballoc: %u PAs left\n", count
);
2436 int ext4_mb_release(struct super_block
*sb
)
2439 int num_meta_group_infos
;
2440 struct ext4_group_info
*grinfo
;
2441 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2443 if (!test_opt(sb
, MBALLOC
))
2446 /* release freed, non-committed blocks */
2447 spin_lock(&sbi
->s_md_lock
);
2448 list_splice_init(&sbi
->s_closed_transaction
,
2449 &sbi
->s_committed_transaction
);
2450 list_splice_init(&sbi
->s_active_transaction
,
2451 &sbi
->s_committed_transaction
);
2452 spin_unlock(&sbi
->s_md_lock
);
2453 ext4_mb_free_committed_blocks(sb
);
2455 if (sbi
->s_group_info
) {
2456 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
2457 grinfo
= ext4_get_group_info(sb
, i
);
2459 kfree(grinfo
->bb_bitmap
);
2461 ext4_lock_group(sb
, i
);
2462 ext4_mb_cleanup_pa(grinfo
);
2463 ext4_unlock_group(sb
, i
);
2466 num_meta_group_infos
= (sbi
->s_groups_count
+
2467 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2468 EXT4_DESC_PER_BLOCK_BITS(sb
);
2469 for (i
= 0; i
< num_meta_group_infos
; i
++)
2470 kfree(sbi
->s_group_info
[i
]);
2471 kfree(sbi
->s_group_info
);
2473 kfree(sbi
->s_mb_offsets
);
2474 kfree(sbi
->s_mb_maxs
);
2475 if (sbi
->s_buddy_cache
)
2476 iput(sbi
->s_buddy_cache
);
2477 if (sbi
->s_mb_stats
) {
2479 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2480 atomic_read(&sbi
->s_bal_allocated
),
2481 atomic_read(&sbi
->s_bal_reqs
),
2482 atomic_read(&sbi
->s_bal_success
));
2484 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2485 "%u 2^N hits, %u breaks, %u lost\n",
2486 atomic_read(&sbi
->s_bal_ex_scanned
),
2487 atomic_read(&sbi
->s_bal_goals
),
2488 atomic_read(&sbi
->s_bal_2orders
),
2489 atomic_read(&sbi
->s_bal_breaks
),
2490 atomic_read(&sbi
->s_mb_lost_chunks
));
2492 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2493 sbi
->s_mb_buddies_generated
++,
2494 sbi
->s_mb_generation_time
);
2496 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2497 atomic_read(&sbi
->s_mb_preallocated
),
2498 atomic_read(&sbi
->s_mb_discarded
));
2501 kfree(sbi
->s_locality_groups
);
2503 ext4_mb_history_release(sb
);
2504 ext4_mb_destroy_per_dev_proc(sb
);
2509 static noinline_for_stack
void
2510 ext4_mb_free_committed_blocks(struct super_block
*sb
)
2512 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2517 struct ext4_free_metadata
*md
;
2518 struct ext4_buddy e4b
;
2520 if (list_empty(&sbi
->s_committed_transaction
))
2523 /* there is committed blocks to be freed yet */
2525 /* get next array of blocks */
2527 spin_lock(&sbi
->s_md_lock
);
2528 if (!list_empty(&sbi
->s_committed_transaction
)) {
2529 md
= list_entry(sbi
->s_committed_transaction
.next
,
2530 struct ext4_free_metadata
, list
);
2531 list_del(&md
->list
);
2533 spin_unlock(&sbi
->s_md_lock
);
2538 mb_debug("gonna free %u blocks in group %lu (0x%p):",
2539 md
->num
, md
->group
, md
);
2541 err
= ext4_mb_load_buddy(sb
, md
->group
, &e4b
);
2542 /* we expect to find existing buddy because it's pinned */
2545 /* there are blocks to put in buddy to make them really free */
2548 ext4_lock_group(sb
, md
->group
);
2549 for (i
= 0; i
< md
->num
; i
++) {
2550 mb_debug(" %u", md
->blocks
[i
]);
2551 err
= mb_free_blocks(NULL
, &e4b
, md
->blocks
[i
], 1);
2555 ext4_unlock_group(sb
, md
->group
);
2557 /* balance refcounts from ext4_mb_free_metadata() */
2558 page_cache_release(e4b
.bd_buddy_page
);
2559 page_cache_release(e4b
.bd_bitmap_page
);
2562 ext4_mb_release_desc(&e4b
);
2566 mb_debug("freed %u blocks in %u structures\n", count
, count2
);
2569 #define EXT4_MB_STATS_NAME "stats"
2570 #define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
2571 #define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
2572 #define EXT4_MB_ORDER2_REQ "order2_req"
2573 #define EXT4_MB_STREAM_REQ "stream_req"
2574 #define EXT4_MB_GROUP_PREALLOC "group_prealloc"
2578 #define MB_PROC_VALUE_READ(name) \
2579 static int ext4_mb_read_##name(char *page, char **start, \
2580 off_t off, int count, int *eof, void *data) \
2582 struct ext4_sb_info *sbi = data; \
2587 len = sprintf(page, "%ld\n", sbi->s_mb_##name); \
2592 #define MB_PROC_VALUE_WRITE(name) \
2593 static int ext4_mb_write_##name(struct file *file, \
2594 const char __user *buf, unsigned long cnt, void *data) \
2596 struct ext4_sb_info *sbi = data; \
2599 if (cnt >= sizeof(str)) \
2601 if (copy_from_user(str, buf, cnt)) \
2603 value = simple_strtol(str, NULL, 0); \
2606 sbi->s_mb_##name = value; \
2610 MB_PROC_VALUE_READ(stats
);
2611 MB_PROC_VALUE_WRITE(stats
);
2612 MB_PROC_VALUE_READ(max_to_scan
);
2613 MB_PROC_VALUE_WRITE(max_to_scan
);
2614 MB_PROC_VALUE_READ(min_to_scan
);
2615 MB_PROC_VALUE_WRITE(min_to_scan
);
2616 MB_PROC_VALUE_READ(order2_reqs
);
2617 MB_PROC_VALUE_WRITE(order2_reqs
);
2618 MB_PROC_VALUE_READ(stream_request
);
2619 MB_PROC_VALUE_WRITE(stream_request
);
2620 MB_PROC_VALUE_READ(group_prealloc
);
2621 MB_PROC_VALUE_WRITE(group_prealloc
);
2623 #define MB_PROC_HANDLER(name, var) \
2625 proc = create_proc_entry(name, mode, sbi->s_mb_proc); \
2626 if (proc == NULL) { \
2627 printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
2631 proc->read_proc = ext4_mb_read_##var ; \
2632 proc->write_proc = ext4_mb_write_##var; \
2635 static int ext4_mb_init_per_dev_proc(struct super_block
*sb
)
2637 mode_t mode
= S_IFREG
| S_IRUGO
| S_IWUSR
;
2638 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2639 struct proc_dir_entry
*proc
;
2642 bdevname(sb
->s_bdev
, devname
);
2643 sbi
->s_mb_proc
= proc_mkdir(devname
, proc_root_ext4
);
2645 MB_PROC_HANDLER(EXT4_MB_STATS_NAME
, stats
);
2646 MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME
, max_to_scan
);
2647 MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME
, min_to_scan
);
2648 MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ
, order2_reqs
);
2649 MB_PROC_HANDLER(EXT4_MB_STREAM_REQ
, stream_request
);
2650 MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC
, group_prealloc
);
2655 printk(KERN_ERR
"EXT4-fs: Unable to create %s\n", devname
);
2656 remove_proc_entry(EXT4_MB_GROUP_PREALLOC
, sbi
->s_mb_proc
);
2657 remove_proc_entry(EXT4_MB_STREAM_REQ
, sbi
->s_mb_proc
);
2658 remove_proc_entry(EXT4_MB_ORDER2_REQ
, sbi
->s_mb_proc
);
2659 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2660 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2661 remove_proc_entry(EXT4_MB_STATS_NAME
, sbi
->s_mb_proc
);
2662 remove_proc_entry(devname
, proc_root_ext4
);
2663 sbi
->s_mb_proc
= NULL
;
2668 static int ext4_mb_destroy_per_dev_proc(struct super_block
*sb
)
2670 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2673 if (sbi
->s_mb_proc
== NULL
)
2676 bdevname(sb
->s_bdev
, devname
);
2677 remove_proc_entry(EXT4_MB_GROUP_PREALLOC
, sbi
->s_mb_proc
);
2678 remove_proc_entry(EXT4_MB_STREAM_REQ
, sbi
->s_mb_proc
);
2679 remove_proc_entry(EXT4_MB_ORDER2_REQ
, sbi
->s_mb_proc
);
2680 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2681 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2682 remove_proc_entry(EXT4_MB_STATS_NAME
, sbi
->s_mb_proc
);
2683 remove_proc_entry(devname
, proc_root_ext4
);
2688 int __init
init_ext4_mballoc(void)
2690 ext4_pspace_cachep
=
2691 kmem_cache_create("ext4_prealloc_space",
2692 sizeof(struct ext4_prealloc_space
),
2693 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2694 if (ext4_pspace_cachep
== NULL
)
2698 kmem_cache_create("ext4_alloc_context",
2699 sizeof(struct ext4_allocation_context
),
2700 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2701 if (ext4_ac_cachep
== NULL
) {
2702 kmem_cache_destroy(ext4_pspace_cachep
);
2705 #ifdef CONFIG_PROC_FS
2706 proc_root_ext4
= proc_mkdir("fs/ext4", NULL
);
2707 if (proc_root_ext4
== NULL
)
2708 printk(KERN_ERR
"EXT4-fs: Unable to create fs/ext4\n");
2713 void exit_ext4_mballoc(void)
2715 /* XXX: synchronize_rcu(); */
2716 kmem_cache_destroy(ext4_pspace_cachep
);
2717 kmem_cache_destroy(ext4_ac_cachep
);
2718 #ifdef CONFIG_PROC_FS
2719 remove_proc_entry("fs/ext4", NULL
);
2725 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
2726 * Returns 0 if success or error code
2728 static noinline_for_stack
int
2729 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2732 struct buffer_head
*bitmap_bh
= NULL
;
2733 struct ext4_super_block
*es
;
2734 struct ext4_group_desc
*gdp
;
2735 struct buffer_head
*gdp_bh
;
2736 struct ext4_sb_info
*sbi
;
2737 struct super_block
*sb
;
2741 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2742 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2748 ext4_debug("using block group %lu(%d)\n", ac
->ac_b_ex
.fe_group
,
2749 gdp
->bg_free_blocks_count
);
2752 bitmap_bh
= read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2756 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2761 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2765 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2769 block
= ac
->ac_b_ex
.fe_group
* EXT4_BLOCKS_PER_GROUP(sb
)
2770 + ac
->ac_b_ex
.fe_start
2771 + le32_to_cpu(es
->s_first_data_block
);
2773 if (block
== ext4_block_bitmap(sb
, gdp
) ||
2774 block
== ext4_inode_bitmap(sb
, gdp
) ||
2775 in_range(block
, ext4_inode_table(sb
, gdp
),
2776 EXT4_SB(sb
)->s_itb_per_group
)) {
2778 ext4_error(sb
, __func__
,
2779 "Allocating block in system zone - block = %llu",
2782 #ifdef AGGRESSIVE_CHECK
2785 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2786 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2787 bitmap_bh
->b_data
));
2791 mb_set_bits(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
), bitmap_bh
->b_data
,
2792 ac
->ac_b_ex
.fe_start
, ac
->ac_b_ex
.fe_len
);
2794 spin_lock(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
));
2795 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2796 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2797 gdp
->bg_free_blocks_count
=
2798 cpu_to_le16(ext4_free_blocks_after_init(sb
,
2799 ac
->ac_b_ex
.fe_group
,
2802 le16_add_cpu(&gdp
->bg_free_blocks_count
, -ac
->ac_b_ex
.fe_len
);
2803 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, ac
->ac_b_ex
.fe_group
, gdp
);
2804 spin_unlock(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
));
2805 percpu_counter_sub(&sbi
->s_freeblocks_counter
, ac
->ac_b_ex
.fe_len
);
2807 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
2810 err
= ext4_journal_dirty_metadata(handle
, gdp_bh
);
2819 * here we normalize request for locality group
2820 * Group request are normalized to s_strip size if we set the same via mount
2821 * option. If not we set it to s_mb_group_prealloc which can be configured via
2822 * /proc/fs/ext4/<partition>/group_prealloc
2824 * XXX: should we try to preallocate more than the group has now?
2826 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2828 struct super_block
*sb
= ac
->ac_sb
;
2829 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2832 if (EXT4_SB(sb
)->s_stripe
)
2833 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_stripe
;
2835 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2836 mb_debug("#%u: goal %u blocks for locality group\n",
2837 current
->pid
, ac
->ac_g_ex
.fe_len
);
2841 * Normalization means making request better in terms of
2842 * size and alignment
2844 static noinline_for_stack
void
2845 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
2846 struct ext4_allocation_request
*ar
)
2850 loff_t size
, orig_size
, start_off
;
2851 ext4_lblk_t start
, orig_start
;
2852 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
2853 struct ext4_prealloc_space
*pa
;
2855 /* do normalize only data requests, metadata requests
2856 do not need preallocation */
2857 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
2860 /* sometime caller may want exact blocks */
2861 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2864 /* caller may indicate that preallocation isn't
2865 * required (it's a tail, for example) */
2866 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
2869 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
2870 ext4_mb_normalize_group_request(ac
);
2874 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
2876 /* first, let's learn actual file size
2877 * given current request is allocated */
2878 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
2879 size
= size
<< bsbits
;
2880 if (size
< i_size_read(ac
->ac_inode
))
2881 size
= i_size_read(ac
->ac_inode
);
2883 /* max available blocks in a free group */
2884 max
= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
) - 1 - 1 -
2885 EXT4_SB(ac
->ac_sb
)->s_itb_per_group
;
2887 #define NRL_CHECK_SIZE(req, size, max,bits) \
2888 (req <= (size) || max <= ((size) >> bits))
2890 /* first, try to predict filesize */
2891 /* XXX: should this table be tunable? */
2893 if (size
<= 16 * 1024) {
2895 } else if (size
<= 32 * 1024) {
2897 } else if (size
<= 64 * 1024) {
2899 } else if (size
<= 128 * 1024) {
2901 } else if (size
<= 256 * 1024) {
2903 } else if (size
<= 512 * 1024) {
2905 } else if (size
<= 1024 * 1024) {
2907 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, bsbits
)) {
2908 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2909 (20 - bsbits
)) << 20;
2911 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, bsbits
)) {
2912 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2913 (22 - bsbits
)) << 22;
2914 size
= 4 * 1024 * 1024;
2915 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
2916 (8<<20)>>bsbits
, max
, bsbits
)) {
2917 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2918 (23 - bsbits
)) << 23;
2919 size
= 8 * 1024 * 1024;
2921 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
2922 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
2924 orig_size
= size
= size
>> bsbits
;
2925 orig_start
= start
= start_off
>> bsbits
;
2927 /* don't cover already allocated blocks in selected range */
2928 if (ar
->pleft
&& start
<= ar
->lleft
) {
2929 size
-= ar
->lleft
+ 1 - start
;
2930 start
= ar
->lleft
+ 1;
2932 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
2933 size
-= start
+ size
- ar
->lright
;
2937 /* check we don't cross already preallocated blocks */
2939 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
2940 unsigned long pa_end
;
2944 spin_lock(&pa
->pa_lock
);
2945 if (pa
->pa_deleted
) {
2946 spin_unlock(&pa
->pa_lock
);
2950 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
2952 /* PA must not overlap original request */
2953 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
2954 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
2956 /* skip PA normalized request doesn't overlap with */
2957 if (pa
->pa_lstart
>= end
) {
2958 spin_unlock(&pa
->pa_lock
);
2961 if (pa_end
<= start
) {
2962 spin_unlock(&pa
->pa_lock
);
2965 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
2967 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
2968 BUG_ON(pa_end
< start
);
2972 if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
2973 BUG_ON(pa
->pa_lstart
> end
);
2974 end
= pa
->pa_lstart
;
2976 spin_unlock(&pa
->pa_lock
);
2981 /* XXX: extra loop to check we really don't overlap preallocations */
2983 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
2984 unsigned long pa_end
;
2985 spin_lock(&pa
->pa_lock
);
2986 if (pa
->pa_deleted
== 0) {
2987 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
2988 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
2990 spin_unlock(&pa
->pa_lock
);
2994 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
2995 start
> ac
->ac_o_ex
.fe_logical
) {
2996 printk(KERN_ERR
"start %lu, size %lu, fe_logical %lu\n",
2997 (unsigned long) start
, (unsigned long) size
,
2998 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3000 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3001 start
> ac
->ac_o_ex
.fe_logical
);
3002 BUG_ON(size
<= 0 || size
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3004 /* now prepare goal request */
3006 /* XXX: is it better to align blocks WRT to logical
3007 * placement or satisfy big request as is */
3008 ac
->ac_g_ex
.fe_logical
= start
;
3009 ac
->ac_g_ex
.fe_len
= size
;
3011 /* define goal start in order to merge */
3012 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3013 /* merge to the right */
3014 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3015 &ac
->ac_f_ex
.fe_group
,
3016 &ac
->ac_f_ex
.fe_start
);
3017 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3019 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3020 /* merge to the left */
3021 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3022 &ac
->ac_f_ex
.fe_group
,
3023 &ac
->ac_f_ex
.fe_start
);
3024 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3027 mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3028 (unsigned) orig_size
, (unsigned) start
);
3031 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3033 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3035 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3036 atomic_inc(&sbi
->s_bal_reqs
);
3037 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3038 if (ac
->ac_o_ex
.fe_len
>= ac
->ac_g_ex
.fe_len
)
3039 atomic_inc(&sbi
->s_bal_success
);
3040 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3041 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3042 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3043 atomic_inc(&sbi
->s_bal_goals
);
3044 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3045 atomic_inc(&sbi
->s_bal_breaks
);
3048 ext4_mb_store_history(ac
);
3052 * use blocks preallocated to inode
3054 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3055 struct ext4_prealloc_space
*pa
)
3061 /* found preallocated blocks, use them */
3062 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3063 end
= min(pa
->pa_pstart
+ pa
->pa_len
, start
+ ac
->ac_o_ex
.fe_len
);
3065 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3066 &ac
->ac_b_ex
.fe_start
);
3067 ac
->ac_b_ex
.fe_len
= len
;
3068 ac
->ac_status
= AC_STATUS_FOUND
;
3071 BUG_ON(start
< pa
->pa_pstart
);
3072 BUG_ON(start
+ len
> pa
->pa_pstart
+ pa
->pa_len
);
3073 BUG_ON(pa
->pa_free
< len
);
3076 mb_debug("use %llu/%u from inode pa %p\n", start
, len
, pa
);
3080 * use blocks preallocated to locality group
3082 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3083 struct ext4_prealloc_space
*pa
)
3085 unsigned len
= ac
->ac_o_ex
.fe_len
;
3087 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3088 &ac
->ac_b_ex
.fe_group
,
3089 &ac
->ac_b_ex
.fe_start
);
3090 ac
->ac_b_ex
.fe_len
= len
;
3091 ac
->ac_status
= AC_STATUS_FOUND
;
3094 /* we don't correct pa_pstart or pa_plen here to avoid
3095 * possible race when the group is being loaded concurrently
3096 * instead we correct pa later, after blocks are marked
3097 * in on-disk bitmap -- see ext4_mb_release_context()
3098 * Other CPUs are prevented from allocating from this pa by lg_mutex
3100 mb_debug("use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3104 * search goal blocks in preallocated space
3106 static noinline_for_stack
int
3107 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3109 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3110 struct ext4_locality_group
*lg
;
3111 struct ext4_prealloc_space
*pa
;
3113 /* only data can be preallocated */
3114 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3117 /* first, try per-file preallocation */
3119 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3121 /* all fields in this condition don't change,
3122 * so we can skip locking for them */
3123 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3124 ac
->ac_o_ex
.fe_logical
>= pa
->pa_lstart
+ pa
->pa_len
)
3127 /* found preallocated blocks, use them */
3128 spin_lock(&pa
->pa_lock
);
3129 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3130 atomic_inc(&pa
->pa_count
);
3131 ext4_mb_use_inode_pa(ac
, pa
);
3132 spin_unlock(&pa
->pa_lock
);
3133 ac
->ac_criteria
= 10;
3137 spin_unlock(&pa
->pa_lock
);
3141 /* can we use group allocation? */
3142 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3145 /* inode may have no locality group for some reason */
3151 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
, pa_inode_list
) {
3152 spin_lock(&pa
->pa_lock
);
3153 if (pa
->pa_deleted
== 0 && pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3154 atomic_inc(&pa
->pa_count
);
3155 ext4_mb_use_group_pa(ac
, pa
);
3156 spin_unlock(&pa
->pa_lock
);
3157 ac
->ac_criteria
= 20;
3161 spin_unlock(&pa
->pa_lock
);
3169 * the function goes through all preallocation in this group and marks them
3170 * used in in-core bitmap. buddy must be generated from this bitmap
3171 * Need to be called with ext4 group lock (ext4_lock_group)
3173 static void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3176 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3177 struct ext4_prealloc_space
*pa
;
3178 struct list_head
*cur
;
3179 ext4_group_t groupnr
;
3180 ext4_grpblk_t start
;
3181 int preallocated
= 0;
3185 /* all form of preallocation discards first load group,
3186 * so the only competing code is preallocation use.
3187 * we don't need any locking here
3188 * notice we do NOT ignore preallocations with pa_deleted
3189 * otherwise we could leave used blocks available for
3190 * allocation in buddy when concurrent ext4_mb_put_pa()
3191 * is dropping preallocation
3193 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3194 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3195 spin_lock(&pa
->pa_lock
);
3196 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3199 spin_unlock(&pa
->pa_lock
);
3200 if (unlikely(len
== 0))
3202 BUG_ON(groupnr
!= group
);
3203 mb_set_bits(sb_bgl_lock(EXT4_SB(sb
), group
),
3204 bitmap
, start
, len
);
3205 preallocated
+= len
;
3208 mb_debug("prellocated %u for group %lu\n", preallocated
, group
);
3211 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3213 struct ext4_prealloc_space
*pa
;
3214 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3215 kmem_cache_free(ext4_pspace_cachep
, pa
);
3219 * drops a reference to preallocated space descriptor
3220 * if this was the last reference and the space is consumed
3222 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3223 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3227 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0)
3230 /* in this short window concurrent discard can set pa_deleted */
3231 spin_lock(&pa
->pa_lock
);
3232 if (pa
->pa_deleted
== 1) {
3233 spin_unlock(&pa
->pa_lock
);
3238 spin_unlock(&pa
->pa_lock
);
3240 /* -1 is to protect from crossing allocation group */
3241 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
- 1, &grp
, NULL
);
3246 * P1 (buddy init) P2 (regular allocation)
3247 * find block B in PA
3248 * copy on-disk bitmap to buddy
3249 * mark B in on-disk bitmap
3250 * drop PA from group
3251 * mark all PAs in buddy
3253 * thus, P1 initializes buddy with B available. to prevent this
3254 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3257 ext4_lock_group(sb
, grp
);
3258 list_del(&pa
->pa_group_list
);
3259 ext4_unlock_group(sb
, grp
);
3261 spin_lock(pa
->pa_obj_lock
);
3262 list_del_rcu(&pa
->pa_inode_list
);
3263 spin_unlock(pa
->pa_obj_lock
);
3265 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3269 * creates new preallocated space for given inode
3271 static noinline_for_stack
int
3272 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3274 struct super_block
*sb
= ac
->ac_sb
;
3275 struct ext4_prealloc_space
*pa
;
3276 struct ext4_group_info
*grp
;
3277 struct ext4_inode_info
*ei
;
3279 /* preallocate only when found space is larger then requested */
3280 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3281 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3282 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3284 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3288 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3294 /* we can't allocate as much as normalizer wants.
3295 * so, found space must get proper lstart
3296 * to cover original request */
3297 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3298 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3300 /* we're limited by original request in that
3301 * logical block must be covered any way
3302 * winl is window we can move our chunk within */
3303 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3305 /* also, we should cover whole original request */
3306 wins
= ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
;
3308 /* the smallest one defines real window */
3309 win
= min(winl
, wins
);
3311 offs
= ac
->ac_o_ex
.fe_logical
% ac
->ac_b_ex
.fe_len
;
3312 if (offs
&& offs
< win
)
3315 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
- win
;
3316 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3317 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3320 /* preallocation can change ac_b_ex, thus we store actually
3321 * allocated blocks for history */
3322 ac
->ac_f_ex
= ac
->ac_b_ex
;
3324 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3325 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3326 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3327 pa
->pa_free
= pa
->pa_len
;
3328 atomic_set(&pa
->pa_count
, 1);
3329 spin_lock_init(&pa
->pa_lock
);
3333 mb_debug("new inode pa %p: %llu/%u for %u\n", pa
,
3334 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3336 ext4_mb_use_inode_pa(ac
, pa
);
3337 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3339 ei
= EXT4_I(ac
->ac_inode
);
3340 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3342 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3343 pa
->pa_inode
= ac
->ac_inode
;
3345 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3346 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3347 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3349 spin_lock(pa
->pa_obj_lock
);
3350 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3351 spin_unlock(pa
->pa_obj_lock
);
3357 * creates new preallocated space for locality group inodes belongs to
3359 static noinline_for_stack
int
3360 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3362 struct super_block
*sb
= ac
->ac_sb
;
3363 struct ext4_locality_group
*lg
;
3364 struct ext4_prealloc_space
*pa
;
3365 struct ext4_group_info
*grp
;
3367 /* preallocate only when found space is larger then requested */
3368 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3369 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3370 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3372 BUG_ON(ext4_pspace_cachep
== NULL
);
3373 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3377 /* preallocation can change ac_b_ex, thus we store actually
3378 * allocated blocks for history */
3379 ac
->ac_f_ex
= ac
->ac_b_ex
;
3381 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3382 pa
->pa_lstart
= pa
->pa_pstart
;
3383 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3384 pa
->pa_free
= pa
->pa_len
;
3385 atomic_set(&pa
->pa_count
, 1);
3386 spin_lock_init(&pa
->pa_lock
);
3390 mb_debug("new group pa %p: %llu/%u for %u\n", pa
,
3391 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3393 ext4_mb_use_group_pa(ac
, pa
);
3394 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3396 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3400 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3401 pa
->pa_inode
= NULL
;
3403 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3404 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3405 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3407 spin_lock(pa
->pa_obj_lock
);
3408 list_add_tail_rcu(&pa
->pa_inode_list
, &lg
->lg_prealloc_list
);
3409 spin_unlock(pa
->pa_obj_lock
);
3414 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3418 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3419 err
= ext4_mb_new_group_pa(ac
);
3421 err
= ext4_mb_new_inode_pa(ac
);
3426 * finds all unused blocks in on-disk bitmap, frees them in
3427 * in-core bitmap and buddy.
3428 * @pa must be unlinked from inode and group lists, so that
3429 * nobody else can find/use it.
3430 * the caller MUST hold group/inode locks.
3431 * TODO: optimize the case when there are no in-core structures yet
3433 static noinline_for_stack
int
3434 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3435 struct ext4_prealloc_space
*pa
,
3436 struct ext4_allocation_context
*ac
)
3438 struct super_block
*sb
= e4b
->bd_sb
;
3439 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3448 BUG_ON(pa
->pa_deleted
== 0);
3449 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3450 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3451 end
= bit
+ pa
->pa_len
;
3455 ac
->ac_inode
= pa
->pa_inode
;
3456 ac
->ac_op
= EXT4_MB_HISTORY_DISCARD
;
3460 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3463 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3466 start
= group
* EXT4_BLOCKS_PER_GROUP(sb
) + bit
+
3467 le32_to_cpu(sbi
->s_es
->s_first_data_block
);
3468 mb_debug(" free preallocated %u/%u in group %u\n",
3469 (unsigned) start
, (unsigned) next
- bit
,
3474 ac
->ac_b_ex
.fe_group
= group
;
3475 ac
->ac_b_ex
.fe_start
= bit
;
3476 ac
->ac_b_ex
.fe_len
= next
- bit
;
3477 ac
->ac_b_ex
.fe_logical
= 0;
3478 ext4_mb_store_history(ac
);
3481 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3484 if (free
!= pa
->pa_free
) {
3485 printk(KERN_CRIT
"pa %p: logic %lu, phys. %lu, len %lu\n",
3486 pa
, (unsigned long) pa
->pa_lstart
,
3487 (unsigned long) pa
->pa_pstart
,
3488 (unsigned long) pa
->pa_len
);
3489 ext4_error(sb
, __func__
, "free %u, pa_free %u\n",
3492 * pa is already deleted so we use the value obtained
3493 * from the bitmap and continue.
3496 atomic_add(free
, &sbi
->s_mb_discarded
);
3501 static noinline_for_stack
int
3502 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3503 struct ext4_prealloc_space
*pa
,
3504 struct ext4_allocation_context
*ac
)
3506 struct super_block
*sb
= e4b
->bd_sb
;
3511 ac
->ac_op
= EXT4_MB_HISTORY_DISCARD
;
3513 BUG_ON(pa
->pa_deleted
== 0);
3514 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3515 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3516 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3517 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3521 ac
->ac_inode
= NULL
;
3522 ac
->ac_b_ex
.fe_group
= group
;
3523 ac
->ac_b_ex
.fe_start
= bit
;
3524 ac
->ac_b_ex
.fe_len
= pa
->pa_len
;
3525 ac
->ac_b_ex
.fe_logical
= 0;
3526 ext4_mb_store_history(ac
);
3533 * releases all preallocations in given group
3535 * first, we need to decide discard policy:
3536 * - when do we discard
3538 * - how many do we discard
3539 * 1) how many requested
3541 static noinline_for_stack
int
3542 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3543 ext4_group_t group
, int needed
)
3545 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3546 struct buffer_head
*bitmap_bh
= NULL
;
3547 struct ext4_prealloc_space
*pa
, *tmp
;
3548 struct ext4_allocation_context
*ac
;
3549 struct list_head list
;
3550 struct ext4_buddy e4b
;
3555 mb_debug("discard preallocation for group %lu\n", group
);
3557 if (list_empty(&grp
->bb_prealloc_list
))
3560 bitmap_bh
= read_block_bitmap(sb
, group
);
3561 if (bitmap_bh
== NULL
) {
3562 /* error handling here */
3563 ext4_mb_release_desc(&e4b
);
3564 BUG_ON(bitmap_bh
== NULL
);
3567 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3568 BUG_ON(err
!= 0); /* error handling here */
3571 needed
= EXT4_BLOCKS_PER_GROUP(sb
) + 1;
3573 grp
= ext4_get_group_info(sb
, group
);
3574 INIT_LIST_HEAD(&list
);
3576 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3578 ext4_lock_group(sb
, group
);
3579 list_for_each_entry_safe(pa
, tmp
,
3580 &grp
->bb_prealloc_list
, pa_group_list
) {
3581 spin_lock(&pa
->pa_lock
);
3582 if (atomic_read(&pa
->pa_count
)) {
3583 spin_unlock(&pa
->pa_lock
);
3587 if (pa
->pa_deleted
) {
3588 spin_unlock(&pa
->pa_lock
);
3592 /* seems this one can be freed ... */
3595 /* we can trust pa_free ... */
3596 free
+= pa
->pa_free
;
3598 spin_unlock(&pa
->pa_lock
);
3600 list_del(&pa
->pa_group_list
);
3601 list_add(&pa
->u
.pa_tmp_list
, &list
);
3604 /* if we still need more blocks and some PAs were used, try again */
3605 if (free
< needed
&& busy
) {
3607 ext4_unlock_group(sb
, group
);
3609 * Yield the CPU here so that we don't get soft lockup
3610 * in non preempt case.
3616 /* found anything to free? */
3617 if (list_empty(&list
)) {
3622 /* now free all selected PAs */
3623 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3625 /* remove from object (inode or locality group) */
3626 spin_lock(pa
->pa_obj_lock
);
3627 list_del_rcu(&pa
->pa_inode_list
);
3628 spin_unlock(pa
->pa_obj_lock
);
3631 ext4_mb_release_group_pa(&e4b
, pa
, ac
);
3633 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3635 list_del(&pa
->u
.pa_tmp_list
);
3636 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3640 ext4_unlock_group(sb
, group
);
3642 kmem_cache_free(ext4_ac_cachep
, ac
);
3643 ext4_mb_release_desc(&e4b
);
3649 * releases all non-used preallocated blocks for given inode
3651 * It's important to discard preallocations under i_data_sem
3652 * We don't want another block to be served from the prealloc
3653 * space when we are discarding the inode prealloc space.
3655 * FIXME!! Make sure it is valid at all the call sites
3657 void ext4_mb_discard_inode_preallocations(struct inode
*inode
)
3659 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3660 struct super_block
*sb
= inode
->i_sb
;
3661 struct buffer_head
*bitmap_bh
= NULL
;
3662 struct ext4_prealloc_space
*pa
, *tmp
;
3663 struct ext4_allocation_context
*ac
;
3664 ext4_group_t group
= 0;
3665 struct list_head list
;
3666 struct ext4_buddy e4b
;
3669 if (!test_opt(sb
, MBALLOC
) || !S_ISREG(inode
->i_mode
)) {
3670 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3674 mb_debug("discard preallocation for inode %lu\n", inode
->i_ino
);
3676 INIT_LIST_HEAD(&list
);
3678 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3680 /* first, collect all pa's in the inode */
3681 spin_lock(&ei
->i_prealloc_lock
);
3682 while (!list_empty(&ei
->i_prealloc_list
)) {
3683 pa
= list_entry(ei
->i_prealloc_list
.next
,
3684 struct ext4_prealloc_space
, pa_inode_list
);
3685 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3686 spin_lock(&pa
->pa_lock
);
3687 if (atomic_read(&pa
->pa_count
)) {
3688 /* this shouldn't happen often - nobody should
3689 * use preallocation while we're discarding it */
3690 spin_unlock(&pa
->pa_lock
);
3691 spin_unlock(&ei
->i_prealloc_lock
);
3692 printk(KERN_ERR
"uh-oh! used pa while discarding\n");
3694 schedule_timeout_uninterruptible(HZ
);
3698 if (pa
->pa_deleted
== 0) {
3700 spin_unlock(&pa
->pa_lock
);
3701 list_del_rcu(&pa
->pa_inode_list
);
3702 list_add(&pa
->u
.pa_tmp_list
, &list
);
3706 /* someone is deleting pa right now */
3707 spin_unlock(&pa
->pa_lock
);
3708 spin_unlock(&ei
->i_prealloc_lock
);
3710 /* we have to wait here because pa_deleted
3711 * doesn't mean pa is already unlinked from
3712 * the list. as we might be called from
3713 * ->clear_inode() the inode will get freed
3714 * and concurrent thread which is unlinking
3715 * pa from inode's list may access already
3716 * freed memory, bad-bad-bad */
3718 /* XXX: if this happens too often, we can
3719 * add a flag to force wait only in case
3720 * of ->clear_inode(), but not in case of
3721 * regular truncate */
3722 schedule_timeout_uninterruptible(HZ
);
3725 spin_unlock(&ei
->i_prealloc_lock
);
3727 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3728 BUG_ON(pa
->pa_linear
!= 0);
3729 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
3731 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3732 BUG_ON(err
!= 0); /* error handling here */
3734 bitmap_bh
= read_block_bitmap(sb
, group
);
3735 if (bitmap_bh
== NULL
) {
3736 /* error handling here */
3737 ext4_mb_release_desc(&e4b
);
3738 BUG_ON(bitmap_bh
== NULL
);
3741 ext4_lock_group(sb
, group
);
3742 list_del(&pa
->pa_group_list
);
3743 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3744 ext4_unlock_group(sb
, group
);
3746 ext4_mb_release_desc(&e4b
);
3749 list_del(&pa
->u
.pa_tmp_list
);
3750 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3753 kmem_cache_free(ext4_ac_cachep
, ac
);
3757 * finds all preallocated spaces and return blocks being freed to them
3758 * if preallocated space becomes full (no block is used from the space)
3759 * then the function frees space in buddy
3760 * XXX: at the moment, truncate (which is the only way to free blocks)
3761 * discards all preallocations
3763 static void ext4_mb_return_to_preallocation(struct inode
*inode
,
3764 struct ext4_buddy
*e4b
,
3765 sector_t block
, int count
)
3767 BUG_ON(!list_empty(&EXT4_I(inode
)->i_prealloc_list
));
3770 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3772 struct super_block
*sb
= ac
->ac_sb
;
3775 printk(KERN_ERR
"EXT4-fs: Can't allocate:"
3776 " Allocation context details:\n");
3777 printk(KERN_ERR
"EXT4-fs: status %d flags %d\n",
3778 ac
->ac_status
, ac
->ac_flags
);
3779 printk(KERN_ERR
"EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
3780 "best %lu/%lu/%lu@%lu cr %d\n",
3781 (unsigned long)ac
->ac_o_ex
.fe_group
,
3782 (unsigned long)ac
->ac_o_ex
.fe_start
,
3783 (unsigned long)ac
->ac_o_ex
.fe_len
,
3784 (unsigned long)ac
->ac_o_ex
.fe_logical
,
3785 (unsigned long)ac
->ac_g_ex
.fe_group
,
3786 (unsigned long)ac
->ac_g_ex
.fe_start
,
3787 (unsigned long)ac
->ac_g_ex
.fe_len
,
3788 (unsigned long)ac
->ac_g_ex
.fe_logical
,
3789 (unsigned long)ac
->ac_b_ex
.fe_group
,
3790 (unsigned long)ac
->ac_b_ex
.fe_start
,
3791 (unsigned long)ac
->ac_b_ex
.fe_len
,
3792 (unsigned long)ac
->ac_b_ex
.fe_logical
,
3793 (int)ac
->ac_criteria
);
3794 printk(KERN_ERR
"EXT4-fs: %lu scanned, %d found\n", ac
->ac_ex_scanned
,
3796 printk(KERN_ERR
"EXT4-fs: groups: \n");
3797 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
; i
++) {
3798 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
3799 struct ext4_prealloc_space
*pa
;
3800 ext4_grpblk_t start
;
3801 struct list_head
*cur
;
3802 ext4_lock_group(sb
, i
);
3803 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3804 pa
= list_entry(cur
, struct ext4_prealloc_space
,
3806 spin_lock(&pa
->pa_lock
);
3807 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3809 spin_unlock(&pa
->pa_lock
);
3810 printk(KERN_ERR
"PA:%lu:%d:%u \n", i
,
3813 ext4_unlock_group(sb
, i
);
3815 if (grp
->bb_free
== 0)
3817 printk(KERN_ERR
"%lu: %d/%d \n",
3818 i
, grp
->bb_free
, grp
->bb_fragments
);
3820 printk(KERN_ERR
"\n");
3823 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3830 * We use locality group preallocation for small size file. The size of the
3831 * file is determined by the current size or the resulting size after
3832 * allocation which ever is larger
3834 * One can tune this size via /proc/fs/ext4/<partition>/stream_req
3836 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
3838 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3839 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3842 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3845 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
3846 isize
= i_size_read(ac
->ac_inode
) >> bsbits
;
3847 size
= max(size
, isize
);
3849 /* don't use group allocation for large files */
3850 if (size
>= sbi
->s_mb_stream_request
)
3853 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3856 BUG_ON(ac
->ac_lg
!= NULL
);
3858 * locality group prealloc space are per cpu. The reason for having
3859 * per cpu locality group is to reduce the contention between block
3860 * request from multiple CPUs.
3862 ac
->ac_lg
= &sbi
->s_locality_groups
[get_cpu()];
3865 /* we're going to use group allocation */
3866 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
3868 /* serialize all allocations in the group */
3869 mutex_lock(&ac
->ac_lg
->lg_mutex
);
3872 static noinline_for_stack
int
3873 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
3874 struct ext4_allocation_request
*ar
)
3876 struct super_block
*sb
= ar
->inode
->i_sb
;
3877 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3878 struct ext4_super_block
*es
= sbi
->s_es
;
3882 ext4_grpblk_t block
;
3884 /* we can't allocate > group size */
3887 /* just a dirty hack to filter too big requests */
3888 if (len
>= EXT4_BLOCKS_PER_GROUP(sb
) - 10)
3889 len
= EXT4_BLOCKS_PER_GROUP(sb
) - 10;
3891 /* start searching from the goal */
3893 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
3894 goal
>= ext4_blocks_count(es
))
3895 goal
= le32_to_cpu(es
->s_first_data_block
);
3896 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
3898 /* set up allocation goals */
3899 ac
->ac_b_ex
.fe_logical
= ar
->logical
;
3900 ac
->ac_b_ex
.fe_group
= 0;
3901 ac
->ac_b_ex
.fe_start
= 0;
3902 ac
->ac_b_ex
.fe_len
= 0;
3903 ac
->ac_status
= AC_STATUS_CONTINUE
;
3904 ac
->ac_groups_scanned
= 0;
3905 ac
->ac_ex_scanned
= 0;
3908 ac
->ac_inode
= ar
->inode
;
3909 ac
->ac_o_ex
.fe_logical
= ar
->logical
;
3910 ac
->ac_o_ex
.fe_group
= group
;
3911 ac
->ac_o_ex
.fe_start
= block
;
3912 ac
->ac_o_ex
.fe_len
= len
;
3913 ac
->ac_g_ex
.fe_logical
= ar
->logical
;
3914 ac
->ac_g_ex
.fe_group
= group
;
3915 ac
->ac_g_ex
.fe_start
= block
;
3916 ac
->ac_g_ex
.fe_len
= len
;
3917 ac
->ac_f_ex
.fe_len
= 0;
3918 ac
->ac_flags
= ar
->flags
;
3920 ac
->ac_criteria
= 0;
3922 ac
->ac_bitmap_page
= NULL
;
3923 ac
->ac_buddy_page
= NULL
;
3926 /* we have to define context: we'll we work with a file or
3927 * locality group. this is a policy, actually */
3928 ext4_mb_group_or_file(ac
);
3930 mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
3931 "left: %u/%u, right %u/%u to %swritable\n",
3932 (unsigned) ar
->len
, (unsigned) ar
->logical
,
3933 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
3934 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
3935 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
3936 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
3942 * release all resource we used in allocation
3944 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
3947 if (ac
->ac_pa
->pa_linear
) {
3948 /* see comment in ext4_mb_use_group_pa() */
3949 spin_lock(&ac
->ac_pa
->pa_lock
);
3950 ac
->ac_pa
->pa_pstart
+= ac
->ac_b_ex
.fe_len
;
3951 ac
->ac_pa
->pa_lstart
+= ac
->ac_b_ex
.fe_len
;
3952 ac
->ac_pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
3953 ac
->ac_pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
3954 spin_unlock(&ac
->ac_pa
->pa_lock
);
3956 ext4_mb_put_pa(ac
, ac
->ac_sb
, ac
->ac_pa
);
3958 if (ac
->ac_bitmap_page
)
3959 page_cache_release(ac
->ac_bitmap_page
);
3960 if (ac
->ac_buddy_page
)
3961 page_cache_release(ac
->ac_buddy_page
);
3962 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3963 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
3964 ext4_mb_collect_stats(ac
);
3968 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
3974 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
&& needed
> 0; i
++) {
3975 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
3984 * Main entry point into mballoc to allocate blocks
3985 * it tries to use preallocation first, then falls back
3986 * to usual allocation
3988 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
3989 struct ext4_allocation_request
*ar
, int *errp
)
3991 struct ext4_allocation_context
*ac
= NULL
;
3992 struct ext4_sb_info
*sbi
;
3993 struct super_block
*sb
;
3994 ext4_fsblk_t block
= 0;
3998 sb
= ar
->inode
->i_sb
;
4001 if (!test_opt(sb
, MBALLOC
)) {
4002 block
= ext4_new_blocks_old(handle
, ar
->inode
, ar
->goal
,
4007 while (ar
->len
&& DQUOT_ALLOC_BLOCK(ar
->inode
, ar
->len
)) {
4008 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4017 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4023 ext4_mb_poll_new_transaction(sb
, handle
);
4025 *errp
= ext4_mb_initialize_context(ac
, ar
);
4031 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4032 if (!ext4_mb_use_preallocated(ac
)) {
4034 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4035 ext4_mb_normalize_request(ac
, ar
);
4038 /* allocate space in core */
4039 ext4_mb_regular_allocator(ac
);
4041 /* as we've just preallocated more space than
4042 * user requested orinally, we store allocated
4043 * space in a special descriptor */
4044 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4045 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4046 ext4_mb_new_preallocation(ac
);
4049 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4050 ext4_mb_mark_diskspace_used(ac
, handle
);
4052 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4053 ar
->len
= ac
->ac_b_ex
.fe_len
;
4055 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4059 ac
->ac_b_ex
.fe_len
= 0;
4061 ext4_mb_show_ac(ac
);
4064 ext4_mb_release_context(ac
);
4067 if (ar
->len
< inquota
)
4068 DQUOT_FREE_BLOCK(ar
->inode
, inquota
- ar
->len
);
4070 kmem_cache_free(ext4_ac_cachep
, ac
);
4073 static void ext4_mb_poll_new_transaction(struct super_block
*sb
,
4076 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4078 if (sbi
->s_last_transaction
== handle
->h_transaction
->t_tid
)
4081 /* new transaction! time to close last one and free blocks for
4082 * committed transaction. we know that only transaction can be
4083 * active, so previos transaction can be being logged and we
4084 * know that transaction before previous is known to be already
4085 * logged. this means that now we may free blocks freed in all
4086 * transactions before previous one. hope I'm clear enough ... */
4088 spin_lock(&sbi
->s_md_lock
);
4089 if (sbi
->s_last_transaction
!= handle
->h_transaction
->t_tid
) {
4090 mb_debug("new transaction %lu, old %lu\n",
4091 (unsigned long) handle
->h_transaction
->t_tid
,
4092 (unsigned long) sbi
->s_last_transaction
);
4093 list_splice_init(&sbi
->s_closed_transaction
,
4094 &sbi
->s_committed_transaction
);
4095 list_splice_init(&sbi
->s_active_transaction
,
4096 &sbi
->s_closed_transaction
);
4097 sbi
->s_last_transaction
= handle
->h_transaction
->t_tid
;
4099 spin_unlock(&sbi
->s_md_lock
);
4101 ext4_mb_free_committed_blocks(sb
);
4104 static noinline_for_stack
int
4105 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4106 ext4_group_t group
, ext4_grpblk_t block
, int count
)
4108 struct ext4_group_info
*db
= e4b
->bd_info
;
4109 struct super_block
*sb
= e4b
->bd_sb
;
4110 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4111 struct ext4_free_metadata
*md
;
4114 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4115 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4117 ext4_lock_group(sb
, group
);
4118 for (i
= 0; i
< count
; i
++) {
4120 if (md
&& db
->bb_tid
!= handle
->h_transaction
->t_tid
) {
4121 db
->bb_md_cur
= NULL
;
4126 ext4_unlock_group(sb
, group
);
4127 md
= kmalloc(sizeof(*md
), GFP_NOFS
);
4133 ext4_lock_group(sb
, group
);
4134 if (db
->bb_md_cur
== NULL
) {
4135 spin_lock(&sbi
->s_md_lock
);
4136 list_add(&md
->list
, &sbi
->s_active_transaction
);
4137 spin_unlock(&sbi
->s_md_lock
);
4138 /* protect buddy cache from being freed,
4139 * otherwise we'll refresh it from
4140 * on-disk bitmap and lose not-yet-available
4142 page_cache_get(e4b
->bd_buddy_page
);
4143 page_cache_get(e4b
->bd_bitmap_page
);
4145 db
->bb_tid
= handle
->h_transaction
->t_tid
;
4146 mb_debug("new md 0x%p for group %lu\n",
4154 BUG_ON(md
->num
>= EXT4_BB_MAX_BLOCKS
);
4155 md
->blocks
[md
->num
] = block
+ i
;
4157 if (md
->num
== EXT4_BB_MAX_BLOCKS
) {
4158 /* no more space, put full container on a sb's list */
4159 db
->bb_md_cur
= NULL
;
4162 ext4_unlock_group(sb
, group
);
4167 * Main entry point into mballoc to free blocks
4169 void ext4_mb_free_blocks(handle_t
*handle
, struct inode
*inode
,
4170 unsigned long block
, unsigned long count
,
4171 int metadata
, unsigned long *freed
)
4173 struct buffer_head
*bitmap_bh
= NULL
;
4174 struct super_block
*sb
= inode
->i_sb
;
4175 struct ext4_allocation_context
*ac
= NULL
;
4176 struct ext4_group_desc
*gdp
;
4177 struct ext4_super_block
*es
;
4178 unsigned long overflow
;
4180 struct buffer_head
*gd_bh
;
4181 ext4_group_t block_group
;
4182 struct ext4_sb_info
*sbi
;
4183 struct ext4_buddy e4b
;
4189 ext4_mb_poll_new_transaction(sb
, handle
);
4192 es
= EXT4_SB(sb
)->s_es
;
4193 if (block
< le32_to_cpu(es
->s_first_data_block
) ||
4194 block
+ count
< block
||
4195 block
+ count
> ext4_blocks_count(es
)) {
4196 ext4_error(sb
, __func__
,
4197 "Freeing blocks not in datazone - "
4198 "block = %lu, count = %lu", block
, count
);
4202 ext4_debug("freeing block %lu\n", block
);
4204 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4206 ac
->ac_op
= EXT4_MB_HISTORY_FREE
;
4207 ac
->ac_inode
= inode
;
4213 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4216 * Check to see if we are freeing blocks across a group
4219 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4220 overflow
= bit
+ count
- EXT4_BLOCKS_PER_GROUP(sb
);
4223 bitmap_bh
= read_block_bitmap(sb
, block_group
);
4226 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4230 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4231 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4232 in_range(block
, ext4_inode_table(sb
, gdp
),
4233 EXT4_SB(sb
)->s_itb_per_group
) ||
4234 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4235 EXT4_SB(sb
)->s_itb_per_group
)) {
4237 ext4_error(sb
, __func__
,
4238 "Freeing blocks in system zone - "
4239 "Block = %lu, count = %lu", block
, count
);
4242 BUFFER_TRACE(bitmap_bh
, "getting write access");
4243 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4248 * We are about to modify some metadata. Call the journal APIs
4249 * to unshare ->b_data if a currently-committing transaction is
4252 BUFFER_TRACE(gd_bh
, "get_write_access");
4253 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4257 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4261 #ifdef AGGRESSIVE_CHECK
4264 for (i
= 0; i
< count
; i
++)
4265 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4268 mb_clear_bits(sb_bgl_lock(sbi
, block_group
), bitmap_bh
->b_data
,
4271 /* We dirtied the bitmap block */
4272 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4273 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
4276 ac
->ac_b_ex
.fe_group
= block_group
;
4277 ac
->ac_b_ex
.fe_start
= bit
;
4278 ac
->ac_b_ex
.fe_len
= count
;
4279 ext4_mb_store_history(ac
);
4283 /* blocks being freed are metadata. these blocks shouldn't
4284 * be used until this transaction is committed */
4285 ext4_mb_free_metadata(handle
, &e4b
, block_group
, bit
, count
);
4287 ext4_lock_group(sb
, block_group
);
4288 err
= mb_free_blocks(inode
, &e4b
, bit
, count
);
4289 ext4_mb_return_to_preallocation(inode
, &e4b
, block
, count
);
4290 ext4_unlock_group(sb
, block_group
);
4294 spin_lock(sb_bgl_lock(sbi
, block_group
));
4295 le16_add_cpu(&gdp
->bg_free_blocks_count
, count
);
4296 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, block_group
, gdp
);
4297 spin_unlock(sb_bgl_lock(sbi
, block_group
));
4298 percpu_counter_add(&sbi
->s_freeblocks_counter
, count
);
4300 ext4_mb_release_desc(&e4b
);
4304 /* And the group descriptor block */
4305 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4306 ret
= ext4_journal_dirty_metadata(handle
, gd_bh
);
4310 if (overflow
&& !err
) {
4319 ext4_std_error(sb
, err
);
4321 kmem_cache_free(ext4_ac_cachep
, ac
);