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
)
384 int fix
= 0, ret
, tmpmax
;
385 addr
= mb_correct_addr_and_bit(&fix
, addr
);
389 ret
= ext4_find_next_zero_bit(addr
, tmpmax
, start
) - fix
;
395 static inline int mb_find_next_bit(void *addr
, int max
, int start
)
397 int fix
= 0, ret
, tmpmax
;
398 addr
= mb_correct_addr_and_bit(&fix
, addr
);
402 ret
= ext4_find_next_bit(addr
, tmpmax
, start
) - fix
;
408 static void *mb_find_buddy(struct ext4_buddy
*e4b
, int order
, int *max
)
412 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
415 if (order
> e4b
->bd_blkbits
+ 1) {
420 /* at order 0 we see each particular block */
421 *max
= 1 << (e4b
->bd_blkbits
+ 3);
423 return EXT4_MB_BITMAP(e4b
);
425 bb
= EXT4_MB_BUDDY(e4b
) + EXT4_SB(e4b
->bd_sb
)->s_mb_offsets
[order
];
426 *max
= EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[order
];
432 static void mb_free_blocks_double(struct inode
*inode
, struct ext4_buddy
*e4b
,
433 int first
, int count
)
436 struct super_block
*sb
= e4b
->bd_sb
;
438 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
440 BUG_ON(!ext4_is_group_locked(sb
, e4b
->bd_group
));
441 for (i
= 0; i
< count
; i
++) {
442 if (!mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
)) {
443 ext4_fsblk_t blocknr
;
444 blocknr
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
);
445 blocknr
+= first
+ i
;
447 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
449 ext4_error(sb
, __func__
, "double-free of inode"
450 " %lu's block %llu(bit %u in group %lu)\n",
451 inode
? inode
->i_ino
: 0, blocknr
,
452 first
+ i
, e4b
->bd_group
);
454 mb_clear_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
458 static void mb_mark_used_double(struct ext4_buddy
*e4b
, int first
, int count
)
462 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
464 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
465 for (i
= 0; i
< count
; i
++) {
466 BUG_ON(mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
));
467 mb_set_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
471 static void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
473 if (memcmp(e4b
->bd_info
->bb_bitmap
, bitmap
, e4b
->bd_sb
->s_blocksize
)) {
474 unsigned char *b1
, *b2
;
476 b1
= (unsigned char *) e4b
->bd_info
->bb_bitmap
;
477 b2
= (unsigned char *) bitmap
;
478 for (i
= 0; i
< e4b
->bd_sb
->s_blocksize
; i
++) {
479 if (b1
[i
] != b2
[i
]) {
480 printk("corruption in group %lu at byte %u(%u):"
481 " %x in copy != %x on disk/prealloc\n",
482 e4b
->bd_group
, i
, i
* 8, b1
[i
], b2
[i
]);
490 static inline void mb_free_blocks_double(struct inode
*inode
,
491 struct ext4_buddy
*e4b
, int first
, int count
)
495 static inline void mb_mark_used_double(struct ext4_buddy
*e4b
,
496 int first
, int count
)
500 static inline void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
506 #ifdef AGGRESSIVE_CHECK
508 #define MB_CHECK_ASSERT(assert) \
512 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
513 function, file, line, # assert); \
518 static int __mb_check_buddy(struct ext4_buddy
*e4b
, char *file
,
519 const char *function
, int line
)
521 struct super_block
*sb
= e4b
->bd_sb
;
522 int order
= e4b
->bd_blkbits
+ 1;
529 struct ext4_group_info
*grp
;
532 struct list_head
*cur
;
536 if (!test_opt(sb
, MBALLOC
))
540 static int mb_check_counter
;
541 if (mb_check_counter
++ % 100 != 0)
546 buddy
= mb_find_buddy(e4b
, order
, &max
);
547 MB_CHECK_ASSERT(buddy
);
548 buddy2
= mb_find_buddy(e4b
, order
- 1, &max2
);
549 MB_CHECK_ASSERT(buddy2
);
550 MB_CHECK_ASSERT(buddy
!= buddy2
);
551 MB_CHECK_ASSERT(max
* 2 == max2
);
554 for (i
= 0; i
< max
; i
++) {
556 if (mb_test_bit(i
, buddy
)) {
557 /* only single bit in buddy2 may be 1 */
558 if (!mb_test_bit(i
<< 1, buddy2
)) {
560 mb_test_bit((i
<<1)+1, buddy2
));
561 } else if (!mb_test_bit((i
<< 1) + 1, buddy2
)) {
563 mb_test_bit(i
<< 1, buddy2
));
568 /* both bits in buddy2 must be 0 */
569 MB_CHECK_ASSERT(mb_test_bit(i
<< 1, buddy2
));
570 MB_CHECK_ASSERT(mb_test_bit((i
<< 1) + 1, buddy2
));
572 for (j
= 0; j
< (1 << order
); j
++) {
573 k
= (i
* (1 << order
)) + j
;
575 !mb_test_bit(k
, EXT4_MB_BITMAP(e4b
)));
579 MB_CHECK_ASSERT(e4b
->bd_info
->bb_counters
[order
] == count
);
584 buddy
= mb_find_buddy(e4b
, 0, &max
);
585 for (i
= 0; i
< max
; i
++) {
586 if (!mb_test_bit(i
, buddy
)) {
587 MB_CHECK_ASSERT(i
>= e4b
->bd_info
->bb_first_free
);
595 /* check used bits only */
596 for (j
= 0; j
< e4b
->bd_blkbits
+ 1; j
++) {
597 buddy2
= mb_find_buddy(e4b
, j
, &max2
);
599 MB_CHECK_ASSERT(k
< max2
);
600 MB_CHECK_ASSERT(mb_test_bit(k
, buddy2
));
603 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b
->bd_info
));
604 MB_CHECK_ASSERT(e4b
->bd_info
->bb_fragments
== fragments
);
606 grp
= ext4_get_group_info(sb
, e4b
->bd_group
);
607 buddy
= mb_find_buddy(e4b
, 0, &max
);
608 list_for_each(cur
, &grp
->bb_prealloc_list
) {
609 ext4_group_t groupnr
;
610 struct ext4_prealloc_space
*pa
;
611 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
612 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &groupnr
, &k
);
613 MB_CHECK_ASSERT(groupnr
== e4b
->bd_group
);
614 for (i
= 0; i
< pa
->pa_len
; i
++)
615 MB_CHECK_ASSERT(mb_test_bit(k
+ i
, buddy
));
619 #undef MB_CHECK_ASSERT
620 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
621 __FILE__, __func__, __LINE__)
623 #define mb_check_buddy(e4b)
626 /* FIXME!! need more doc */
627 static void ext4_mb_mark_free_simple(struct super_block
*sb
,
628 void *buddy
, unsigned first
, int len
,
629 struct ext4_group_info
*grp
)
631 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
634 unsigned short chunk
;
635 unsigned short border
;
637 BUG_ON(len
> EXT4_BLOCKS_PER_GROUP(sb
));
639 border
= 2 << sb
->s_blocksize_bits
;
642 /* find how many blocks can be covered since this position */
643 max
= ffs(first
| border
) - 1;
645 /* find how many blocks of power 2 we need to mark */
652 /* mark multiblock chunks only */
653 grp
->bb_counters
[min
]++;
655 mb_clear_bit(first
>> min
,
656 buddy
+ sbi
->s_mb_offsets
[min
]);
663 static void ext4_mb_generate_buddy(struct super_block
*sb
,
664 void *buddy
, void *bitmap
, ext4_group_t group
)
666 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
667 unsigned short max
= EXT4_BLOCKS_PER_GROUP(sb
);
668 unsigned short i
= 0;
669 unsigned short first
;
672 unsigned fragments
= 0;
673 unsigned long long period
= get_cycles();
675 /* initialize buddy from bitmap which is aggregation
676 * of on-disk bitmap and preallocations */
677 i
= mb_find_next_zero_bit(bitmap
, max
, 0);
678 grp
->bb_first_free
= i
;
682 i
= mb_find_next_bit(bitmap
, max
, i
);
686 ext4_mb_mark_free_simple(sb
, buddy
, first
, len
, grp
);
688 grp
->bb_counters
[0]++;
690 i
= mb_find_next_zero_bit(bitmap
, max
, i
);
692 grp
->bb_fragments
= fragments
;
694 if (free
!= grp
->bb_free
) {
695 ext4_error(sb
, __func__
,
696 "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
697 group
, free
, grp
->bb_free
);
699 * If we intent to continue, we consider group descritor
700 * corrupt and update bb_free using bitmap value
705 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
, &(grp
->bb_state
));
707 period
= get_cycles() - period
;
708 spin_lock(&EXT4_SB(sb
)->s_bal_lock
);
709 EXT4_SB(sb
)->s_mb_buddies_generated
++;
710 EXT4_SB(sb
)->s_mb_generation_time
+= period
;
711 spin_unlock(&EXT4_SB(sb
)->s_bal_lock
);
714 /* The buddy information is attached the buddy cache inode
715 * for convenience. The information regarding each group
716 * is loaded via ext4_mb_load_buddy. The information involve
717 * block bitmap and buddy information. The information are
718 * stored in the inode as
721 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
724 * one block each for bitmap and buddy information.
725 * So for each group we take up 2 blocks. A page can
726 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
727 * So it can have information regarding groups_per_page which
728 * is blocks_per_page/2
731 static int ext4_mb_init_cache(struct page
*page
, char *incore
)
738 ext4_group_t first_group
;
740 struct super_block
*sb
;
741 struct buffer_head
*bhs
;
742 struct buffer_head
**bh
;
747 mb_debug("init page %lu\n", page
->index
);
749 inode
= page
->mapping
->host
;
751 blocksize
= 1 << inode
->i_blkbits
;
752 blocks_per_page
= PAGE_CACHE_SIZE
/ blocksize
;
754 groups_per_page
= blocks_per_page
>> 1;
755 if (groups_per_page
== 0)
758 /* allocate buffer_heads to read bitmaps */
759 if (groups_per_page
> 1) {
761 i
= sizeof(struct buffer_head
*) * groups_per_page
;
762 bh
= kzalloc(i
, GFP_NOFS
);
768 first_group
= page
->index
* blocks_per_page
/ 2;
770 /* read all groups the page covers into the cache */
771 for (i
= 0; i
< groups_per_page
; i
++) {
772 struct ext4_group_desc
*desc
;
774 if (first_group
+ i
>= EXT4_SB(sb
)->s_groups_count
)
778 desc
= ext4_get_group_desc(sb
, first_group
+ i
, NULL
);
783 bh
[i
] = sb_getblk(sb
, ext4_block_bitmap(sb
, desc
));
787 if (bh_uptodate_or_lock(bh
[i
]))
790 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
791 ext4_init_block_bitmap(sb
, bh
[i
],
792 first_group
+ i
, desc
);
793 set_buffer_uptodate(bh
[i
]);
794 unlock_buffer(bh
[i
]);
798 bh
[i
]->b_end_io
= end_buffer_read_sync
;
799 submit_bh(READ
, bh
[i
]);
800 mb_debug("read bitmap for group %lu\n", first_group
+ i
);
803 /* wait for I/O completion */
804 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
805 wait_on_buffer(bh
[i
]);
808 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
809 if (!buffer_uptodate(bh
[i
]))
812 first_block
= page
->index
* blocks_per_page
;
813 for (i
= 0; i
< blocks_per_page
; i
++) {
815 struct ext4_group_info
*grinfo
;
817 group
= (first_block
+ i
) >> 1;
818 if (group
>= EXT4_SB(sb
)->s_groups_count
)
822 * data carry information regarding this
823 * particular group in the format specified
827 data
= page_address(page
) + (i
* blocksize
);
828 bitmap
= bh
[group
- first_group
]->b_data
;
831 * We place the buddy block and bitmap block
834 if ((first_block
+ i
) & 1) {
835 /* this is block of buddy */
836 BUG_ON(incore
== NULL
);
837 mb_debug("put buddy for group %u in page %lu/%x\n",
838 group
, page
->index
, i
* blocksize
);
839 memset(data
, 0xff, blocksize
);
840 grinfo
= ext4_get_group_info(sb
, group
);
841 grinfo
->bb_fragments
= 0;
842 memset(grinfo
->bb_counters
, 0,
843 sizeof(unsigned short)*(sb
->s_blocksize_bits
+2));
845 * incore got set to the group block bitmap below
847 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
850 /* this is block of bitmap */
851 BUG_ON(incore
!= NULL
);
852 mb_debug("put bitmap for group %u in page %lu/%x\n",
853 group
, page
->index
, i
* blocksize
);
855 /* see comments in ext4_mb_put_pa() */
856 ext4_lock_group(sb
, group
);
857 memcpy(data
, bitmap
, blocksize
);
859 /* mark all preallocated blks used in in-core bitmap */
860 ext4_mb_generate_from_pa(sb
, data
, group
);
861 ext4_unlock_group(sb
, group
);
863 /* set incore so that the buddy information can be
864 * generated using this
869 SetPageUptodate(page
);
873 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
881 static noinline_for_stack
int
882 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
883 struct ext4_buddy
*e4b
)
885 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
886 struct inode
*inode
= sbi
->s_buddy_cache
;
893 mb_debug("load group %lu\n", group
);
895 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
897 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
898 e4b
->bd_info
= ext4_get_group_info(sb
, group
);
900 e4b
->bd_group
= group
;
901 e4b
->bd_buddy_page
= NULL
;
902 e4b
->bd_bitmap_page
= NULL
;
905 * the buddy cache inode stores the block bitmap
906 * and buddy information in consecutive blocks.
907 * So for each group we need two blocks.
910 pnum
= block
/ blocks_per_page
;
911 poff
= block
% blocks_per_page
;
913 /* we could use find_or_create_page(), but it locks page
914 * what we'd like to avoid in fast path ... */
915 page
= find_get_page(inode
->i_mapping
, pnum
);
916 if (page
== NULL
|| !PageUptodate(page
)) {
918 page_cache_release(page
);
919 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
921 BUG_ON(page
->mapping
!= inode
->i_mapping
);
922 if (!PageUptodate(page
)) {
923 ext4_mb_init_cache(page
, NULL
);
924 mb_cmp_bitmaps(e4b
, page_address(page
) +
925 (poff
* sb
->s_blocksize
));
930 if (page
== NULL
|| !PageUptodate(page
))
932 e4b
->bd_bitmap_page
= page
;
933 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
934 mark_page_accessed(page
);
937 pnum
= block
/ blocks_per_page
;
938 poff
= block
% blocks_per_page
;
940 page
= find_get_page(inode
->i_mapping
, pnum
);
941 if (page
== NULL
|| !PageUptodate(page
)) {
943 page_cache_release(page
);
944 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
946 BUG_ON(page
->mapping
!= inode
->i_mapping
);
947 if (!PageUptodate(page
))
948 ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
953 if (page
== NULL
|| !PageUptodate(page
))
955 e4b
->bd_buddy_page
= page
;
956 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
957 mark_page_accessed(page
);
959 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
960 BUG_ON(e4b
->bd_buddy_page
== NULL
);
965 if (e4b
->bd_bitmap_page
)
966 page_cache_release(e4b
->bd_bitmap_page
);
967 if (e4b
->bd_buddy_page
)
968 page_cache_release(e4b
->bd_buddy_page
);
969 e4b
->bd_buddy
= NULL
;
970 e4b
->bd_bitmap
= NULL
;
974 static void ext4_mb_release_desc(struct ext4_buddy
*e4b
)
976 if (e4b
->bd_bitmap_page
)
977 page_cache_release(e4b
->bd_bitmap_page
);
978 if (e4b
->bd_buddy_page
)
979 page_cache_release(e4b
->bd_buddy_page
);
983 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
988 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
989 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
991 bb
= EXT4_MB_BUDDY(e4b
);
992 while (order
<= e4b
->bd_blkbits
+ 1) {
994 if (!mb_test_bit(block
, bb
)) {
995 /* this block is part of buddy of order 'order' */
998 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1004 static void mb_clear_bits(spinlock_t
*lock
, void *bm
, int cur
, int len
)
1010 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1011 /* fast path: clear whole word at once */
1012 addr
= bm
+ (cur
>> 3);
1017 mb_clear_bit_atomic(lock
, cur
, bm
);
1022 static void mb_set_bits(spinlock_t
*lock
, void *bm
, int cur
, int len
)
1028 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1029 /* fast path: set whole word at once */
1030 addr
= bm
+ (cur
>> 3);
1035 mb_set_bit_atomic(lock
, cur
, bm
);
1040 static int mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1041 int first
, int count
)
1048 struct super_block
*sb
= e4b
->bd_sb
;
1050 BUG_ON(first
+ count
> (sb
->s_blocksize
<< 3));
1051 BUG_ON(!ext4_is_group_locked(sb
, e4b
->bd_group
));
1052 mb_check_buddy(e4b
);
1053 mb_free_blocks_double(inode
, e4b
, first
, count
);
1055 e4b
->bd_info
->bb_free
+= count
;
1056 if (first
< e4b
->bd_info
->bb_first_free
)
1057 e4b
->bd_info
->bb_first_free
= first
;
1059 /* let's maintain fragments counter */
1061 block
= !mb_test_bit(first
- 1, EXT4_MB_BITMAP(e4b
));
1062 if (first
+ count
< EXT4_SB(sb
)->s_mb_maxs
[0])
1063 max
= !mb_test_bit(first
+ count
, EXT4_MB_BITMAP(e4b
));
1065 e4b
->bd_info
->bb_fragments
--;
1066 else if (!block
&& !max
)
1067 e4b
->bd_info
->bb_fragments
++;
1069 /* let's maintain buddy itself */
1070 while (count
-- > 0) {
1074 if (!mb_test_bit(block
, EXT4_MB_BITMAP(e4b
))) {
1075 ext4_fsblk_t blocknr
;
1076 blocknr
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
);
1079 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
1081 ext4_error(sb
, __func__
, "double-free of inode"
1082 " %lu's block %llu(bit %u in group %lu)\n",
1083 inode
? inode
->i_ino
: 0, blocknr
, block
,
1086 mb_clear_bit(block
, EXT4_MB_BITMAP(e4b
));
1087 e4b
->bd_info
->bb_counters
[order
]++;
1089 /* start of the buddy */
1090 buddy
= mb_find_buddy(e4b
, order
, &max
);
1094 if (mb_test_bit(block
, buddy
) ||
1095 mb_test_bit(block
+ 1, buddy
))
1098 /* both the buddies are free, try to coalesce them */
1099 buddy2
= mb_find_buddy(e4b
, order
+ 1, &max
);
1105 /* for special purposes, we don't set
1106 * free bits in bitmap */
1107 mb_set_bit(block
, buddy
);
1108 mb_set_bit(block
+ 1, buddy
);
1110 e4b
->bd_info
->bb_counters
[order
]--;
1111 e4b
->bd_info
->bb_counters
[order
]--;
1115 e4b
->bd_info
->bb_counters
[order
]++;
1117 mb_clear_bit(block
, buddy2
);
1121 mb_check_buddy(e4b
);
1126 static int mb_find_extent(struct ext4_buddy
*e4b
, int order
, int block
,
1127 int needed
, struct ext4_free_extent
*ex
)
1134 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
1137 buddy
= mb_find_buddy(e4b
, order
, &max
);
1138 BUG_ON(buddy
== NULL
);
1139 BUG_ON(block
>= max
);
1140 if (mb_test_bit(block
, buddy
)) {
1147 /* FIXME dorp order completely ? */
1148 if (likely(order
== 0)) {
1149 /* find actual order */
1150 order
= mb_find_order_for_block(e4b
, block
);
1151 block
= block
>> order
;
1154 ex
->fe_len
= 1 << order
;
1155 ex
->fe_start
= block
<< order
;
1156 ex
->fe_group
= e4b
->bd_group
;
1158 /* calc difference from given start */
1159 next
= next
- ex
->fe_start
;
1161 ex
->fe_start
+= next
;
1163 while (needed
> ex
->fe_len
&&
1164 (buddy
= mb_find_buddy(e4b
, order
, &max
))) {
1166 if (block
+ 1 >= max
)
1169 next
= (block
+ 1) * (1 << order
);
1170 if (mb_test_bit(next
, EXT4_MB_BITMAP(e4b
)))
1173 ord
= mb_find_order_for_block(e4b
, next
);
1176 block
= next
>> order
;
1177 ex
->fe_len
+= 1 << order
;
1180 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1184 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1190 int start
= ex
->fe_start
;
1191 int len
= ex
->fe_len
;
1196 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1197 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1198 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
1199 mb_check_buddy(e4b
);
1200 mb_mark_used_double(e4b
, start
, len
);
1202 e4b
->bd_info
->bb_free
-= len
;
1203 if (e4b
->bd_info
->bb_first_free
== start
)
1204 e4b
->bd_info
->bb_first_free
+= len
;
1206 /* let's maintain fragments counter */
1208 mlen
= !mb_test_bit(start
- 1, EXT4_MB_BITMAP(e4b
));
1209 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1210 max
= !mb_test_bit(start
+ len
, EXT4_MB_BITMAP(e4b
));
1212 e4b
->bd_info
->bb_fragments
++;
1213 else if (!mlen
&& !max
)
1214 e4b
->bd_info
->bb_fragments
--;
1216 /* let's maintain buddy itself */
1218 ord
= mb_find_order_for_block(e4b
, start
);
1220 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1221 /* the whole chunk may be allocated at once! */
1223 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1224 BUG_ON((start
>> ord
) >= max
);
1225 mb_set_bit(start
>> ord
, buddy
);
1226 e4b
->bd_info
->bb_counters
[ord
]--;
1233 /* store for history */
1235 ret
= len
| (ord
<< 16);
1237 /* we have to split large buddy */
1239 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1240 mb_set_bit(start
>> ord
, buddy
);
1241 e4b
->bd_info
->bb_counters
[ord
]--;
1244 cur
= (start
>> ord
) & ~1U;
1245 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1246 mb_clear_bit(cur
, buddy
);
1247 mb_clear_bit(cur
+ 1, buddy
);
1248 e4b
->bd_info
->bb_counters
[ord
]++;
1249 e4b
->bd_info
->bb_counters
[ord
]++;
1252 mb_set_bits(sb_bgl_lock(EXT4_SB(e4b
->bd_sb
), ex
->fe_group
),
1253 EXT4_MB_BITMAP(e4b
), ex
->fe_start
, len0
);
1254 mb_check_buddy(e4b
);
1260 * Must be called under group lock!
1262 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1263 struct ext4_buddy
*e4b
)
1265 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1268 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1269 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1271 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1272 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1273 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1275 /* preallocation can change ac_b_ex, thus we store actually
1276 * allocated blocks for history */
1277 ac
->ac_f_ex
= ac
->ac_b_ex
;
1279 ac
->ac_status
= AC_STATUS_FOUND
;
1280 ac
->ac_tail
= ret
& 0xffff;
1281 ac
->ac_buddy
= ret
>> 16;
1283 /* XXXXXXX: SUCH A HORRIBLE **CK */
1285 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1286 get_page(ac
->ac_bitmap_page
);
1287 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1288 get_page(ac
->ac_buddy_page
);
1290 /* store last allocated for subsequent stream allocation */
1291 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
)) {
1292 spin_lock(&sbi
->s_md_lock
);
1293 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1294 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1295 spin_unlock(&sbi
->s_md_lock
);
1300 * regular allocator, for general purposes allocation
1303 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1304 struct ext4_buddy
*e4b
,
1307 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1308 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1309 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1310 struct ext4_free_extent ex
;
1314 * We don't want to scan for a whole year
1316 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1317 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1318 ac
->ac_status
= AC_STATUS_BREAK
;
1323 * Haven't found good chunk so far, let's continue
1325 if (bex
->fe_len
< gex
->fe_len
)
1328 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1329 && bex
->fe_group
== e4b
->bd_group
) {
1330 /* recheck chunk's availability - we don't know
1331 * when it was found (within this lock-unlock
1333 max
= mb_find_extent(e4b
, 0, bex
->fe_start
, gex
->fe_len
, &ex
);
1334 if (max
>= gex
->fe_len
) {
1335 ext4_mb_use_best_found(ac
, e4b
);
1342 * The routine checks whether found extent is good enough. If it is,
1343 * then the extent gets marked used and flag is set to the context
1344 * to stop scanning. Otherwise, the extent is compared with the
1345 * previous found extent and if new one is better, then it's stored
1346 * in the context. Later, the best found extent will be used, if
1347 * mballoc can't find good enough extent.
1349 * FIXME: real allocation policy is to be designed yet!
1351 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1352 struct ext4_free_extent
*ex
,
1353 struct ext4_buddy
*e4b
)
1355 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1356 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1358 BUG_ON(ex
->fe_len
<= 0);
1359 BUG_ON(ex
->fe_len
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1360 BUG_ON(ex
->fe_start
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1361 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1366 * The special case - take what you catch first
1368 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1370 ext4_mb_use_best_found(ac
, e4b
);
1375 * Let's check whether the chuck is good enough
1377 if (ex
->fe_len
== gex
->fe_len
) {
1379 ext4_mb_use_best_found(ac
, e4b
);
1384 * If this is first found extent, just store it in the context
1386 if (bex
->fe_len
== 0) {
1392 * If new found extent is better, store it in the context
1394 if (bex
->fe_len
< gex
->fe_len
) {
1395 /* if the request isn't satisfied, any found extent
1396 * larger than previous best one is better */
1397 if (ex
->fe_len
> bex
->fe_len
)
1399 } else if (ex
->fe_len
> gex
->fe_len
) {
1400 /* if the request is satisfied, then we try to find
1401 * an extent that still satisfy the request, but is
1402 * smaller than previous one */
1403 if (ex
->fe_len
< bex
->fe_len
)
1407 ext4_mb_check_limits(ac
, e4b
, 0);
1410 static int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1411 struct ext4_buddy
*e4b
)
1413 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1414 ext4_group_t group
= ex
.fe_group
;
1418 BUG_ON(ex
.fe_len
<= 0);
1419 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1423 ext4_lock_group(ac
->ac_sb
, group
);
1424 max
= mb_find_extent(e4b
, 0, ex
.fe_start
, ex
.fe_len
, &ex
);
1428 ext4_mb_use_best_found(ac
, e4b
);
1431 ext4_unlock_group(ac
->ac_sb
, group
);
1432 ext4_mb_release_desc(e4b
);
1437 static int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1438 struct ext4_buddy
*e4b
)
1440 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1443 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1444 struct ext4_super_block
*es
= sbi
->s_es
;
1445 struct ext4_free_extent ex
;
1447 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1450 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1454 ext4_lock_group(ac
->ac_sb
, group
);
1455 max
= mb_find_extent(e4b
, 0, ac
->ac_g_ex
.fe_start
,
1456 ac
->ac_g_ex
.fe_len
, &ex
);
1458 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1461 start
= (e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
)) +
1462 ex
.fe_start
+ le32_to_cpu(es
->s_first_data_block
);
1463 /* use do_div to get remainder (would be 64-bit modulo) */
1464 if (do_div(start
, sbi
->s_stripe
) == 0) {
1467 ext4_mb_use_best_found(ac
, e4b
);
1469 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1470 BUG_ON(ex
.fe_len
<= 0);
1471 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1472 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1475 ext4_mb_use_best_found(ac
, e4b
);
1476 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1477 /* Sometimes, caller may want to merge even small
1478 * number of blocks to an existing extent */
1479 BUG_ON(ex
.fe_len
<= 0);
1480 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1481 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1484 ext4_mb_use_best_found(ac
, e4b
);
1486 ext4_unlock_group(ac
->ac_sb
, group
);
1487 ext4_mb_release_desc(e4b
);
1493 * The routine scans buddy structures (not bitmap!) from given order
1494 * to max order and tries to find big enough chunk to satisfy the req
1496 static void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1497 struct ext4_buddy
*e4b
)
1499 struct super_block
*sb
= ac
->ac_sb
;
1500 struct ext4_group_info
*grp
= e4b
->bd_info
;
1506 BUG_ON(ac
->ac_2order
<= 0);
1507 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1508 if (grp
->bb_counters
[i
] == 0)
1511 buddy
= mb_find_buddy(e4b
, i
, &max
);
1512 BUG_ON(buddy
== NULL
);
1514 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1519 ac
->ac_b_ex
.fe_len
= 1 << i
;
1520 ac
->ac_b_ex
.fe_start
= k
<< i
;
1521 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1523 ext4_mb_use_best_found(ac
, e4b
);
1525 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1527 if (EXT4_SB(sb
)->s_mb_stats
)
1528 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1535 * The routine scans the group and measures all found extents.
1536 * In order to optimize scanning, caller must pass number of
1537 * free blocks in the group, so the routine can know upper limit.
1539 static void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1540 struct ext4_buddy
*e4b
)
1542 struct super_block
*sb
= ac
->ac_sb
;
1543 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1544 struct ext4_free_extent ex
;
1548 free
= e4b
->bd_info
->bb_free
;
1551 i
= e4b
->bd_info
->bb_first_free
;
1553 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1554 i
= mb_find_next_zero_bit(bitmap
,
1555 EXT4_BLOCKS_PER_GROUP(sb
), i
);
1556 if (i
>= EXT4_BLOCKS_PER_GROUP(sb
)) {
1558 * IF we have corrupt bitmap, we won't find any
1559 * free blocks even though group info says we
1560 * we have free blocks
1562 ext4_error(sb
, __func__
, "%d free blocks as per "
1563 "group info. But bitmap says 0\n",
1568 mb_find_extent(e4b
, 0, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1569 BUG_ON(ex
.fe_len
<= 0);
1570 if (free
< ex
.fe_len
) {
1571 ext4_error(sb
, __func__
, "%d free blocks as per "
1572 "group info. But got %d blocks\n",
1575 * The number of free blocks differs. This mostly
1576 * indicate that the bitmap is corrupt. So exit
1577 * without claiming the space.
1582 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1588 ext4_mb_check_limits(ac
, e4b
, 1);
1592 * This is a special case for storages like raid5
1593 * we try to find stripe-aligned chunks for stripe-size requests
1594 * XXX should do so at least for multiples of stripe size as well
1596 static void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1597 struct ext4_buddy
*e4b
)
1599 struct super_block
*sb
= ac
->ac_sb
;
1600 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1601 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1602 struct ext4_free_extent ex
;
1603 ext4_fsblk_t first_group_block
;
1608 BUG_ON(sbi
->s_stripe
== 0);
1610 /* find first stripe-aligned block in group */
1611 first_group_block
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
)
1612 + le32_to_cpu(sbi
->s_es
->s_first_data_block
);
1613 a
= first_group_block
+ sbi
->s_stripe
- 1;
1614 do_div(a
, sbi
->s_stripe
);
1615 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1617 while (i
< EXT4_BLOCKS_PER_GROUP(sb
)) {
1618 if (!mb_test_bit(i
, bitmap
)) {
1619 max
= mb_find_extent(e4b
, 0, i
, sbi
->s_stripe
, &ex
);
1620 if (max
>= sbi
->s_stripe
) {
1623 ext4_mb_use_best_found(ac
, e4b
);
1631 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
1632 ext4_group_t group
, int cr
)
1634 unsigned free
, fragments
;
1636 struct ext4_group_desc
*desc
;
1637 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1639 BUG_ON(cr
< 0 || cr
>= 4);
1640 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp
));
1642 free
= grp
->bb_free
;
1643 fragments
= grp
->bb_fragments
;
1651 BUG_ON(ac
->ac_2order
== 0);
1652 /* If this group is uninitialized, skip it initially */
1653 desc
= ext4_get_group_desc(ac
->ac_sb
, group
, NULL
);
1654 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
))
1657 bits
= ac
->ac_sb
->s_blocksize_bits
+ 1;
1658 for (i
= ac
->ac_2order
; i
<= bits
; i
++)
1659 if (grp
->bb_counters
[i
] > 0)
1663 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
1667 if (free
>= ac
->ac_g_ex
.fe_len
)
1679 static noinline_for_stack
int
1680 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
1687 struct ext4_sb_info
*sbi
;
1688 struct super_block
*sb
;
1689 struct ext4_buddy e4b
;
1694 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1696 /* first, try the goal */
1697 err
= ext4_mb_find_by_goal(ac
, &e4b
);
1698 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
1701 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
1705 * ac->ac2_order is set only if the fe_len is a power of 2
1706 * if ac2_order is set we also set criteria to 0 so that we
1707 * try exact allocation using buddy.
1709 i
= fls(ac
->ac_g_ex
.fe_len
);
1712 * We search using buddy data only if the order of the request
1713 * is greater than equal to the sbi_s_mb_order2_reqs
1714 * You can tune it via /proc/fs/ext4/<partition>/order2_req
1716 if (i
>= sbi
->s_mb_order2_reqs
) {
1718 * This should tell if fe_len is exactly power of 2
1720 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
1721 ac
->ac_2order
= i
- 1;
1724 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
1725 /* if stream allocation is enabled, use global goal */
1726 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
1727 isize
= i_size_read(ac
->ac_inode
) >> bsbits
;
1731 if (size
< sbi
->s_mb_stream_request
&&
1732 (ac
->ac_flags
& EXT4_MB_HINT_DATA
)) {
1733 /* TBD: may be hot point */
1734 spin_lock(&sbi
->s_md_lock
);
1735 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
1736 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
1737 spin_unlock(&sbi
->s_md_lock
);
1739 /* Let's just scan groups to find more-less suitable blocks */
1740 cr
= ac
->ac_2order
? 0 : 1;
1742 * cr == 0 try to get exact allocation,
1743 * cr == 3 try to get anything
1746 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
1747 ac
->ac_criteria
= cr
;
1749 * searching for the right group start
1750 * from the goal value specified
1752 group
= ac
->ac_g_ex
.fe_group
;
1754 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
; group
++, i
++) {
1755 struct ext4_group_info
*grp
;
1756 struct ext4_group_desc
*desc
;
1758 if (group
== EXT4_SB(sb
)->s_groups_count
)
1761 /* quick check to skip empty groups */
1762 grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1763 if (grp
->bb_free
== 0)
1767 * if the group is already init we check whether it is
1768 * a good group and if not we don't load the buddy
1770 if (EXT4_MB_GRP_NEED_INIT(grp
)) {
1772 * we need full data about the group
1773 * to make a good selection
1775 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
1778 ext4_mb_release_desc(&e4b
);
1782 * If the particular group doesn't satisfy our
1783 * criteria we continue with the next group
1785 if (!ext4_mb_good_group(ac
, group
, cr
))
1788 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
1792 ext4_lock_group(sb
, group
);
1793 if (!ext4_mb_good_group(ac
, group
, cr
)) {
1794 /* someone did allocation from this group */
1795 ext4_unlock_group(sb
, group
);
1796 ext4_mb_release_desc(&e4b
);
1800 ac
->ac_groups_scanned
++;
1801 desc
= ext4_get_group_desc(sb
, group
, NULL
);
1802 if (cr
== 0 || (desc
->bg_flags
&
1803 cpu_to_le16(EXT4_BG_BLOCK_UNINIT
) &&
1804 ac
->ac_2order
!= 0))
1805 ext4_mb_simple_scan_group(ac
, &e4b
);
1807 ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
)
1808 ext4_mb_scan_aligned(ac
, &e4b
);
1810 ext4_mb_complex_scan_group(ac
, &e4b
);
1812 ext4_unlock_group(sb
, group
);
1813 ext4_mb_release_desc(&e4b
);
1815 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
1820 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
1821 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1823 * We've been searching too long. Let's try to allocate
1824 * the best chunk we've found so far
1827 ext4_mb_try_best_found(ac
, &e4b
);
1828 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
1830 * Someone more lucky has already allocated it.
1831 * The only thing we can do is just take first
1833 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
1835 ac
->ac_b_ex
.fe_group
= 0;
1836 ac
->ac_b_ex
.fe_start
= 0;
1837 ac
->ac_b_ex
.fe_len
= 0;
1838 ac
->ac_status
= AC_STATUS_CONTINUE
;
1839 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
1841 atomic_inc(&sbi
->s_mb_lost_chunks
);
1849 #ifdef EXT4_MB_HISTORY
1850 struct ext4_mb_proc_session
{
1851 struct ext4_mb_history
*history
;
1852 struct super_block
*sb
;
1857 static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session
*s
,
1858 struct ext4_mb_history
*hs
,
1861 if (hs
== s
->history
+ s
->max
)
1863 if (!first
&& hs
== s
->history
+ s
->start
)
1865 while (hs
->orig
.fe_len
== 0) {
1867 if (hs
== s
->history
+ s
->max
)
1869 if (hs
== s
->history
+ s
->start
)
1875 static void *ext4_mb_seq_history_start(struct seq_file
*seq
, loff_t
*pos
)
1877 struct ext4_mb_proc_session
*s
= seq
->private;
1878 struct ext4_mb_history
*hs
;
1882 return SEQ_START_TOKEN
;
1883 hs
= ext4_mb_history_skip_empty(s
, s
->history
+ s
->start
, 1);
1886 while (--l
&& (hs
= ext4_mb_history_skip_empty(s
, ++hs
, 0)) != NULL
);
1890 static void *ext4_mb_seq_history_next(struct seq_file
*seq
, void *v
,
1893 struct ext4_mb_proc_session
*s
= seq
->private;
1894 struct ext4_mb_history
*hs
= v
;
1897 if (v
== SEQ_START_TOKEN
)
1898 return ext4_mb_history_skip_empty(s
, s
->history
+ s
->start
, 1);
1900 return ext4_mb_history_skip_empty(s
, ++hs
, 0);
1903 static int ext4_mb_seq_history_show(struct seq_file
*seq
, void *v
)
1905 char buf
[25], buf2
[25], buf3
[25], *fmt
;
1906 struct ext4_mb_history
*hs
= v
;
1908 if (v
== SEQ_START_TOKEN
) {
1909 seq_printf(seq
, "%-5s %-8s %-23s %-23s %-23s %-5s "
1910 "%-5s %-2s %-5s %-5s %-5s %-6s\n",
1911 "pid", "inode", "original", "goal", "result", "found",
1912 "grps", "cr", "flags", "merge", "tail", "broken");
1916 if (hs
->op
== EXT4_MB_HISTORY_ALLOC
) {
1917 fmt
= "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
1918 "%-5u %-5s %-5u %-6u\n";
1919 sprintf(buf2
, "%lu/%d/%u@%u", hs
->result
.fe_group
,
1920 hs
->result
.fe_start
, hs
->result
.fe_len
,
1921 hs
->result
.fe_logical
);
1922 sprintf(buf
, "%lu/%d/%u@%u", hs
->orig
.fe_group
,
1923 hs
->orig
.fe_start
, hs
->orig
.fe_len
,
1924 hs
->orig
.fe_logical
);
1925 sprintf(buf3
, "%lu/%d/%u@%u", hs
->goal
.fe_group
,
1926 hs
->goal
.fe_start
, hs
->goal
.fe_len
,
1927 hs
->goal
.fe_logical
);
1928 seq_printf(seq
, fmt
, hs
->pid
, hs
->ino
, buf
, buf3
, buf2
,
1929 hs
->found
, hs
->groups
, hs
->cr
, hs
->flags
,
1930 hs
->merged
? "M" : "", hs
->tail
,
1931 hs
->buddy
? 1 << hs
->buddy
: 0);
1932 } else if (hs
->op
== EXT4_MB_HISTORY_PREALLOC
) {
1933 fmt
= "%-5u %-8u %-23s %-23s %-23s\n";
1934 sprintf(buf2
, "%lu/%d/%u@%u", hs
->result
.fe_group
,
1935 hs
->result
.fe_start
, hs
->result
.fe_len
,
1936 hs
->result
.fe_logical
);
1937 sprintf(buf
, "%lu/%d/%u@%u", hs
->orig
.fe_group
,
1938 hs
->orig
.fe_start
, hs
->orig
.fe_len
,
1939 hs
->orig
.fe_logical
);
1940 seq_printf(seq
, fmt
, hs
->pid
, hs
->ino
, buf
, "", buf2
);
1941 } else if (hs
->op
== EXT4_MB_HISTORY_DISCARD
) {
1942 sprintf(buf2
, "%lu/%d/%u", hs
->result
.fe_group
,
1943 hs
->result
.fe_start
, hs
->result
.fe_len
);
1944 seq_printf(seq
, "%-5u %-8u %-23s discard\n",
1945 hs
->pid
, hs
->ino
, buf2
);
1946 } else if (hs
->op
== EXT4_MB_HISTORY_FREE
) {
1947 sprintf(buf2
, "%lu/%d/%u", hs
->result
.fe_group
,
1948 hs
->result
.fe_start
, hs
->result
.fe_len
);
1949 seq_printf(seq
, "%-5u %-8u %-23s free\n",
1950 hs
->pid
, hs
->ino
, buf2
);
1955 static void ext4_mb_seq_history_stop(struct seq_file
*seq
, void *v
)
1959 static struct seq_operations ext4_mb_seq_history_ops
= {
1960 .start
= ext4_mb_seq_history_start
,
1961 .next
= ext4_mb_seq_history_next
,
1962 .stop
= ext4_mb_seq_history_stop
,
1963 .show
= ext4_mb_seq_history_show
,
1966 static int ext4_mb_seq_history_open(struct inode
*inode
, struct file
*file
)
1968 struct super_block
*sb
= PDE(inode
)->data
;
1969 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1970 struct ext4_mb_proc_session
*s
;
1974 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1978 size
= sizeof(struct ext4_mb_history
) * sbi
->s_mb_history_max
;
1979 s
->history
= kmalloc(size
, GFP_KERNEL
);
1980 if (s
->history
== NULL
) {
1985 spin_lock(&sbi
->s_mb_history_lock
);
1986 memcpy(s
->history
, sbi
->s_mb_history
, size
);
1987 s
->max
= sbi
->s_mb_history_max
;
1988 s
->start
= sbi
->s_mb_history_cur
% s
->max
;
1989 spin_unlock(&sbi
->s_mb_history_lock
);
1991 rc
= seq_open(file
, &ext4_mb_seq_history_ops
);
1993 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2003 static int ext4_mb_seq_history_release(struct inode
*inode
, struct file
*file
)
2005 struct seq_file
*seq
= (struct seq_file
*)file
->private_data
;
2006 struct ext4_mb_proc_session
*s
= seq
->private;
2009 return seq_release(inode
, file
);
2012 static ssize_t
ext4_mb_seq_history_write(struct file
*file
,
2013 const char __user
*buffer
,
2014 size_t count
, loff_t
*ppos
)
2016 struct seq_file
*seq
= (struct seq_file
*)file
->private_data
;
2017 struct ext4_mb_proc_session
*s
= seq
->private;
2018 struct super_block
*sb
= s
->sb
;
2022 if (count
>= sizeof(str
)) {
2023 printk(KERN_ERR
"EXT4-fs: %s string too long, max %u bytes\n",
2024 "mb_history", (int)sizeof(str
));
2028 if (copy_from_user(str
, buffer
, count
))
2031 value
= simple_strtol(str
, NULL
, 0);
2034 EXT4_SB(sb
)->s_mb_history_filter
= value
;
2039 static struct file_operations ext4_mb_seq_history_fops
= {
2040 .owner
= THIS_MODULE
,
2041 .open
= ext4_mb_seq_history_open
,
2043 .write
= ext4_mb_seq_history_write
,
2044 .llseek
= seq_lseek
,
2045 .release
= ext4_mb_seq_history_release
,
2048 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2050 struct super_block
*sb
= seq
->private;
2051 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2054 if (*pos
< 0 || *pos
>= sbi
->s_groups_count
)
2058 return (void *) group
;
2061 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2063 struct super_block
*sb
= seq
->private;
2064 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2068 if (*pos
< 0 || *pos
>= sbi
->s_groups_count
)
2071 return (void *) group
;;
2074 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2076 struct super_block
*sb
= seq
->private;
2077 long group
= (long) v
;
2080 struct ext4_buddy e4b
;
2082 struct ext4_group_info info
;
2083 unsigned short counters
[16];
2088 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2089 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2090 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2091 "group", "free", "frags", "first",
2092 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2093 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2095 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2096 sizeof(struct ext4_group_info
);
2097 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2099 seq_printf(seq
, "#%-5lu: I/O error\n", group
);
2102 ext4_lock_group(sb
, group
);
2103 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2104 ext4_unlock_group(sb
, group
);
2105 ext4_mb_release_desc(&e4b
);
2107 seq_printf(seq
, "#%-5lu: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2108 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2109 for (i
= 0; i
<= 13; i
++)
2110 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2111 sg
.info
.bb_counters
[i
] : 0);
2112 seq_printf(seq
, " ]\n");
2117 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2121 static struct seq_operations ext4_mb_seq_groups_ops
= {
2122 .start
= ext4_mb_seq_groups_start
,
2123 .next
= ext4_mb_seq_groups_next
,
2124 .stop
= ext4_mb_seq_groups_stop
,
2125 .show
= ext4_mb_seq_groups_show
,
2128 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2130 struct super_block
*sb
= PDE(inode
)->data
;
2133 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2135 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2142 static struct file_operations ext4_mb_seq_groups_fops
= {
2143 .owner
= THIS_MODULE
,
2144 .open
= ext4_mb_seq_groups_open
,
2146 .llseek
= seq_lseek
,
2147 .release
= seq_release
,
2150 static void ext4_mb_history_release(struct super_block
*sb
)
2152 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2154 remove_proc_entry("mb_groups", sbi
->s_mb_proc
);
2155 remove_proc_entry("mb_history", sbi
->s_mb_proc
);
2157 kfree(sbi
->s_mb_history
);
2160 static void ext4_mb_history_init(struct super_block
*sb
)
2162 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2165 if (sbi
->s_mb_proc
!= NULL
) {
2166 proc_create_data("mb_history", S_IRUGO
, sbi
->s_mb_proc
,
2167 &ext4_mb_seq_history_fops
, sb
);
2168 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_mb_proc
,
2169 &ext4_mb_seq_groups_fops
, sb
);
2172 sbi
->s_mb_history_max
= 1000;
2173 sbi
->s_mb_history_cur
= 0;
2174 spin_lock_init(&sbi
->s_mb_history_lock
);
2175 i
= sbi
->s_mb_history_max
* sizeof(struct ext4_mb_history
);
2176 sbi
->s_mb_history
= kmalloc(i
, GFP_KERNEL
);
2177 if (likely(sbi
->s_mb_history
!= NULL
))
2178 memset(sbi
->s_mb_history
, 0, i
);
2179 /* if we can't allocate history, then we simple won't use it */
2182 static noinline_for_stack
void
2183 ext4_mb_store_history(struct ext4_allocation_context
*ac
)
2185 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
2186 struct ext4_mb_history h
;
2188 if (unlikely(sbi
->s_mb_history
== NULL
))
2191 if (!(ac
->ac_op
& sbi
->s_mb_history_filter
))
2195 h
.pid
= current
->pid
;
2196 h
.ino
= ac
->ac_inode
? ac
->ac_inode
->i_ino
: 0;
2197 h
.orig
= ac
->ac_o_ex
;
2198 h
.result
= ac
->ac_b_ex
;
2199 h
.flags
= ac
->ac_flags
;
2200 h
.found
= ac
->ac_found
;
2201 h
.groups
= ac
->ac_groups_scanned
;
2202 h
.cr
= ac
->ac_criteria
;
2203 h
.tail
= ac
->ac_tail
;
2204 h
.buddy
= ac
->ac_buddy
;
2206 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
) {
2207 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
2208 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
2210 h
.goal
= ac
->ac_g_ex
;
2211 h
.result
= ac
->ac_f_ex
;
2214 spin_lock(&sbi
->s_mb_history_lock
);
2215 memcpy(sbi
->s_mb_history
+ sbi
->s_mb_history_cur
, &h
, sizeof(h
));
2216 if (++sbi
->s_mb_history_cur
>= sbi
->s_mb_history_max
)
2217 sbi
->s_mb_history_cur
= 0;
2218 spin_unlock(&sbi
->s_mb_history_lock
);
2222 #define ext4_mb_history_release(sb)
2223 #define ext4_mb_history_init(sb)
2226 static int ext4_mb_init_backend(struct super_block
*sb
)
2229 int j
, len
, metalen
;
2230 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2231 int num_meta_group_infos
=
2232 (sbi
->s_groups_count
+ EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2233 EXT4_DESC_PER_BLOCK_BITS(sb
);
2234 struct ext4_group_info
**meta_group_info
;
2236 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2237 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2238 * So a two level scheme suffices for now. */
2239 sbi
->s_group_info
= kmalloc(sizeof(*sbi
->s_group_info
) *
2240 num_meta_group_infos
, GFP_KERNEL
);
2241 if (sbi
->s_group_info
== NULL
) {
2242 printk(KERN_ERR
"EXT4-fs: can't allocate buddy meta group\n");
2245 sbi
->s_buddy_cache
= new_inode(sb
);
2246 if (sbi
->s_buddy_cache
== NULL
) {
2247 printk(KERN_ERR
"EXT4-fs: can't get new inode\n");
2250 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2252 metalen
= sizeof(*meta_group_info
) << EXT4_DESC_PER_BLOCK_BITS(sb
);
2253 for (i
= 0; i
< num_meta_group_infos
; i
++) {
2254 if ((i
+ 1) == num_meta_group_infos
)
2255 metalen
= sizeof(*meta_group_info
) *
2256 (sbi
->s_groups_count
-
2257 (i
<< EXT4_DESC_PER_BLOCK_BITS(sb
)));
2258 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2259 if (meta_group_info
== NULL
) {
2260 printk(KERN_ERR
"EXT4-fs: can't allocate mem for a "
2264 sbi
->s_group_info
[i
] = meta_group_info
;
2268 * calculate needed size. if change bb_counters size,
2269 * don't forget about ext4_mb_generate_buddy()
2271 len
= sizeof(struct ext4_group_info
);
2272 len
+= sizeof(unsigned short) * (sb
->s_blocksize_bits
+ 2);
2273 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
2274 struct ext4_group_desc
*desc
;
2277 sbi
->s_group_info
[i
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2278 j
= i
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2280 meta_group_info
[j
] = kzalloc(len
, GFP_KERNEL
);
2281 if (meta_group_info
[j
] == NULL
) {
2282 printk(KERN_ERR
"EXT4-fs: can't allocate buddy mem\n");
2285 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2288 "EXT4-fs: can't read descriptor %lu\n", i
);
2292 memset(meta_group_info
[j
], 0, len
);
2293 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2294 &(meta_group_info
[j
]->bb_state
));
2297 * initialize bb_free to be able to skip
2298 * empty groups without initialization
2300 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2301 meta_group_info
[j
]->bb_free
=
2302 ext4_free_blocks_after_init(sb
, i
, desc
);
2304 meta_group_info
[j
]->bb_free
=
2305 le16_to_cpu(desc
->bg_free_blocks_count
);
2308 INIT_LIST_HEAD(&meta_group_info
[j
]->bb_prealloc_list
);
2312 struct buffer_head
*bh
;
2313 meta_group_info
[j
]->bb_bitmap
=
2314 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2315 BUG_ON(meta_group_info
[j
]->bb_bitmap
== NULL
);
2316 bh
= read_block_bitmap(sb
, i
);
2318 memcpy(meta_group_info
[j
]->bb_bitmap
, bh
->b_data
,
2330 kfree(ext4_get_group_info(sb
, i
));
2331 i
= num_meta_group_infos
;
2334 kfree(sbi
->s_group_info
[i
]);
2335 iput(sbi
->s_buddy_cache
);
2337 kfree(sbi
->s_group_info
);
2341 int ext4_mb_init(struct super_block
*sb
, int needs_recovery
)
2343 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2348 if (!test_opt(sb
, MBALLOC
))
2351 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(unsigned short);
2353 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2354 if (sbi
->s_mb_offsets
== NULL
) {
2355 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2358 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2359 if (sbi
->s_mb_maxs
== NULL
) {
2360 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2361 kfree(sbi
->s_mb_maxs
);
2365 /* order 0 is regular bitmap */
2366 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2367 sbi
->s_mb_offsets
[0] = 0;
2371 max
= sb
->s_blocksize
<< 2;
2373 sbi
->s_mb_offsets
[i
] = offset
;
2374 sbi
->s_mb_maxs
[i
] = max
;
2375 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2378 } while (i
<= sb
->s_blocksize_bits
+ 1);
2380 /* init file for buddy data */
2381 i
= ext4_mb_init_backend(sb
);
2383 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2384 kfree(sbi
->s_mb_offsets
);
2385 kfree(sbi
->s_mb_maxs
);
2389 spin_lock_init(&sbi
->s_md_lock
);
2390 INIT_LIST_HEAD(&sbi
->s_active_transaction
);
2391 INIT_LIST_HEAD(&sbi
->s_closed_transaction
);
2392 INIT_LIST_HEAD(&sbi
->s_committed_transaction
);
2393 spin_lock_init(&sbi
->s_bal_lock
);
2395 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2396 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2397 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2398 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2399 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2400 sbi
->s_mb_history_filter
= EXT4_MB_HISTORY_DEFAULT
;
2401 sbi
->s_mb_group_prealloc
= MB_DEFAULT_GROUP_PREALLOC
;
2403 i
= sizeof(struct ext4_locality_group
) * NR_CPUS
;
2404 sbi
->s_locality_groups
= kmalloc(i
, GFP_KERNEL
);
2405 if (sbi
->s_locality_groups
== NULL
) {
2406 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2407 kfree(sbi
->s_mb_offsets
);
2408 kfree(sbi
->s_mb_maxs
);
2411 for (i
= 0; i
< NR_CPUS
; i
++) {
2412 struct ext4_locality_group
*lg
;
2413 lg
= &sbi
->s_locality_groups
[i
];
2414 mutex_init(&lg
->lg_mutex
);
2415 INIT_LIST_HEAD(&lg
->lg_prealloc_list
);
2416 spin_lock_init(&lg
->lg_prealloc_lock
);
2419 ext4_mb_init_per_dev_proc(sb
);
2420 ext4_mb_history_init(sb
);
2422 printk("EXT4-fs: mballoc enabled\n");
2426 /* need to called with ext4 group lock (ext4_lock_group) */
2427 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2429 struct ext4_prealloc_space
*pa
;
2430 struct list_head
*cur
, *tmp
;
2433 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2434 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2435 list_del(&pa
->pa_group_list
);
2440 mb_debug("mballoc: %u PAs left\n", count
);
2444 int ext4_mb_release(struct super_block
*sb
)
2447 int num_meta_group_infos
;
2448 struct ext4_group_info
*grinfo
;
2449 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2451 if (!test_opt(sb
, MBALLOC
))
2454 /* release freed, non-committed blocks */
2455 spin_lock(&sbi
->s_md_lock
);
2456 list_splice_init(&sbi
->s_closed_transaction
,
2457 &sbi
->s_committed_transaction
);
2458 list_splice_init(&sbi
->s_active_transaction
,
2459 &sbi
->s_committed_transaction
);
2460 spin_unlock(&sbi
->s_md_lock
);
2461 ext4_mb_free_committed_blocks(sb
);
2463 if (sbi
->s_group_info
) {
2464 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
2465 grinfo
= ext4_get_group_info(sb
, i
);
2467 kfree(grinfo
->bb_bitmap
);
2469 ext4_lock_group(sb
, i
);
2470 ext4_mb_cleanup_pa(grinfo
);
2471 ext4_unlock_group(sb
, i
);
2474 num_meta_group_infos
= (sbi
->s_groups_count
+
2475 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2476 EXT4_DESC_PER_BLOCK_BITS(sb
);
2477 for (i
= 0; i
< num_meta_group_infos
; i
++)
2478 kfree(sbi
->s_group_info
[i
]);
2479 kfree(sbi
->s_group_info
);
2481 kfree(sbi
->s_mb_offsets
);
2482 kfree(sbi
->s_mb_maxs
);
2483 if (sbi
->s_buddy_cache
)
2484 iput(sbi
->s_buddy_cache
);
2485 if (sbi
->s_mb_stats
) {
2487 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2488 atomic_read(&sbi
->s_bal_allocated
),
2489 atomic_read(&sbi
->s_bal_reqs
),
2490 atomic_read(&sbi
->s_bal_success
));
2492 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2493 "%u 2^N hits, %u breaks, %u lost\n",
2494 atomic_read(&sbi
->s_bal_ex_scanned
),
2495 atomic_read(&sbi
->s_bal_goals
),
2496 atomic_read(&sbi
->s_bal_2orders
),
2497 atomic_read(&sbi
->s_bal_breaks
),
2498 atomic_read(&sbi
->s_mb_lost_chunks
));
2500 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2501 sbi
->s_mb_buddies_generated
++,
2502 sbi
->s_mb_generation_time
);
2504 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2505 atomic_read(&sbi
->s_mb_preallocated
),
2506 atomic_read(&sbi
->s_mb_discarded
));
2509 kfree(sbi
->s_locality_groups
);
2511 ext4_mb_history_release(sb
);
2512 ext4_mb_destroy_per_dev_proc(sb
);
2517 static noinline_for_stack
void
2518 ext4_mb_free_committed_blocks(struct super_block
*sb
)
2520 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2525 struct ext4_free_metadata
*md
;
2526 struct ext4_buddy e4b
;
2528 if (list_empty(&sbi
->s_committed_transaction
))
2531 /* there is committed blocks to be freed yet */
2533 /* get next array of blocks */
2535 spin_lock(&sbi
->s_md_lock
);
2536 if (!list_empty(&sbi
->s_committed_transaction
)) {
2537 md
= list_entry(sbi
->s_committed_transaction
.next
,
2538 struct ext4_free_metadata
, list
);
2539 list_del(&md
->list
);
2541 spin_unlock(&sbi
->s_md_lock
);
2546 mb_debug("gonna free %u blocks in group %lu (0x%p):",
2547 md
->num
, md
->group
, md
);
2549 err
= ext4_mb_load_buddy(sb
, md
->group
, &e4b
);
2550 /* we expect to find existing buddy because it's pinned */
2553 /* there are blocks to put in buddy to make them really free */
2556 ext4_lock_group(sb
, md
->group
);
2557 for (i
= 0; i
< md
->num
; i
++) {
2558 mb_debug(" %u", md
->blocks
[i
]);
2559 err
= mb_free_blocks(NULL
, &e4b
, md
->blocks
[i
], 1);
2563 ext4_unlock_group(sb
, md
->group
);
2565 /* balance refcounts from ext4_mb_free_metadata() */
2566 page_cache_release(e4b
.bd_buddy_page
);
2567 page_cache_release(e4b
.bd_bitmap_page
);
2570 ext4_mb_release_desc(&e4b
);
2574 mb_debug("freed %u blocks in %u structures\n", count
, count2
);
2577 #define EXT4_MB_STATS_NAME "stats"
2578 #define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
2579 #define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
2580 #define EXT4_MB_ORDER2_REQ "order2_req"
2581 #define EXT4_MB_STREAM_REQ "stream_req"
2582 #define EXT4_MB_GROUP_PREALLOC "group_prealloc"
2586 #define MB_PROC_VALUE_READ(name) \
2587 static int ext4_mb_read_##name(char *page, char **start, \
2588 off_t off, int count, int *eof, void *data) \
2590 struct ext4_sb_info *sbi = data; \
2595 len = sprintf(page, "%ld\n", sbi->s_mb_##name); \
2600 #define MB_PROC_VALUE_WRITE(name) \
2601 static int ext4_mb_write_##name(struct file *file, \
2602 const char __user *buf, unsigned long cnt, void *data) \
2604 struct ext4_sb_info *sbi = data; \
2607 if (cnt >= sizeof(str)) \
2609 if (copy_from_user(str, buf, cnt)) \
2611 value = simple_strtol(str, NULL, 0); \
2614 sbi->s_mb_##name = value; \
2618 MB_PROC_VALUE_READ(stats
);
2619 MB_PROC_VALUE_WRITE(stats
);
2620 MB_PROC_VALUE_READ(max_to_scan
);
2621 MB_PROC_VALUE_WRITE(max_to_scan
);
2622 MB_PROC_VALUE_READ(min_to_scan
);
2623 MB_PROC_VALUE_WRITE(min_to_scan
);
2624 MB_PROC_VALUE_READ(order2_reqs
);
2625 MB_PROC_VALUE_WRITE(order2_reqs
);
2626 MB_PROC_VALUE_READ(stream_request
);
2627 MB_PROC_VALUE_WRITE(stream_request
);
2628 MB_PROC_VALUE_READ(group_prealloc
);
2629 MB_PROC_VALUE_WRITE(group_prealloc
);
2631 #define MB_PROC_HANDLER(name, var) \
2633 proc = create_proc_entry(name, mode, sbi->s_mb_proc); \
2634 if (proc == NULL) { \
2635 printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
2639 proc->read_proc = ext4_mb_read_##var ; \
2640 proc->write_proc = ext4_mb_write_##var; \
2643 static int ext4_mb_init_per_dev_proc(struct super_block
*sb
)
2645 mode_t mode
= S_IFREG
| S_IRUGO
| S_IWUSR
;
2646 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2647 struct proc_dir_entry
*proc
;
2650 bdevname(sb
->s_bdev
, devname
);
2651 sbi
->s_mb_proc
= proc_mkdir(devname
, proc_root_ext4
);
2653 MB_PROC_HANDLER(EXT4_MB_STATS_NAME
, stats
);
2654 MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME
, max_to_scan
);
2655 MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME
, min_to_scan
);
2656 MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ
, order2_reqs
);
2657 MB_PROC_HANDLER(EXT4_MB_STREAM_REQ
, stream_request
);
2658 MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC
, group_prealloc
);
2663 printk(KERN_ERR
"EXT4-fs: Unable to create %s\n", devname
);
2664 remove_proc_entry(EXT4_MB_GROUP_PREALLOC
, sbi
->s_mb_proc
);
2665 remove_proc_entry(EXT4_MB_STREAM_REQ
, sbi
->s_mb_proc
);
2666 remove_proc_entry(EXT4_MB_ORDER2_REQ
, sbi
->s_mb_proc
);
2667 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2668 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2669 remove_proc_entry(EXT4_MB_STATS_NAME
, sbi
->s_mb_proc
);
2670 remove_proc_entry(devname
, proc_root_ext4
);
2671 sbi
->s_mb_proc
= NULL
;
2676 static int ext4_mb_destroy_per_dev_proc(struct super_block
*sb
)
2678 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2681 if (sbi
->s_mb_proc
== NULL
)
2684 bdevname(sb
->s_bdev
, devname
);
2685 remove_proc_entry(EXT4_MB_GROUP_PREALLOC
, sbi
->s_mb_proc
);
2686 remove_proc_entry(EXT4_MB_STREAM_REQ
, sbi
->s_mb_proc
);
2687 remove_proc_entry(EXT4_MB_ORDER2_REQ
, sbi
->s_mb_proc
);
2688 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2689 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2690 remove_proc_entry(EXT4_MB_STATS_NAME
, sbi
->s_mb_proc
);
2691 remove_proc_entry(devname
, proc_root_ext4
);
2696 int __init
init_ext4_mballoc(void)
2698 ext4_pspace_cachep
=
2699 kmem_cache_create("ext4_prealloc_space",
2700 sizeof(struct ext4_prealloc_space
),
2701 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2702 if (ext4_pspace_cachep
== NULL
)
2706 kmem_cache_create("ext4_alloc_context",
2707 sizeof(struct ext4_allocation_context
),
2708 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2709 if (ext4_ac_cachep
== NULL
) {
2710 kmem_cache_destroy(ext4_pspace_cachep
);
2713 #ifdef CONFIG_PROC_FS
2714 proc_root_ext4
= proc_mkdir("fs/ext4", NULL
);
2715 if (proc_root_ext4
== NULL
)
2716 printk(KERN_ERR
"EXT4-fs: Unable to create fs/ext4\n");
2721 void exit_ext4_mballoc(void)
2723 /* XXX: synchronize_rcu(); */
2724 kmem_cache_destroy(ext4_pspace_cachep
);
2725 kmem_cache_destroy(ext4_ac_cachep
);
2726 #ifdef CONFIG_PROC_FS
2727 remove_proc_entry("fs/ext4", NULL
);
2733 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
2734 * Returns 0 if success or error code
2736 static noinline_for_stack
int
2737 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2740 struct buffer_head
*bitmap_bh
= NULL
;
2741 struct ext4_super_block
*es
;
2742 struct ext4_group_desc
*gdp
;
2743 struct buffer_head
*gdp_bh
;
2744 struct ext4_sb_info
*sbi
;
2745 struct super_block
*sb
;
2749 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2750 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2758 bitmap_bh
= read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2762 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2767 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2771 ext4_debug("using block group %lu(%d)\n", ac
->ac_b_ex
.fe_group
,
2772 gdp
->bg_free_blocks_count
);
2774 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2778 block
= ac
->ac_b_ex
.fe_group
* EXT4_BLOCKS_PER_GROUP(sb
)
2779 + ac
->ac_b_ex
.fe_start
2780 + le32_to_cpu(es
->s_first_data_block
);
2782 len
= ac
->ac_b_ex
.fe_len
;
2783 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, len
) ||
2784 in_range(ext4_inode_bitmap(sb
, gdp
), block
, len
) ||
2785 in_range(block
, ext4_inode_table(sb
, gdp
),
2786 EXT4_SB(sb
)->s_itb_per_group
) ||
2787 in_range(block
+ len
- 1, ext4_inode_table(sb
, gdp
),
2788 EXT4_SB(sb
)->s_itb_per_group
)) {
2789 ext4_error(sb
, __func__
,
2790 "Allocating block in system zone - block = %llu",
2792 /* File system mounted not to panic on error
2793 * Fix the bitmap and repeat the block allocation
2794 * We leak some of the blocks here.
2796 mb_set_bits(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
),
2797 bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2798 ac
->ac_b_ex
.fe_len
);
2799 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
2804 #ifdef AGGRESSIVE_CHECK
2807 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2808 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2809 bitmap_bh
->b_data
));
2813 mb_set_bits(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
), bitmap_bh
->b_data
,
2814 ac
->ac_b_ex
.fe_start
, ac
->ac_b_ex
.fe_len
);
2816 spin_lock(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
));
2817 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2818 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2819 gdp
->bg_free_blocks_count
=
2820 cpu_to_le16(ext4_free_blocks_after_init(sb
,
2821 ac
->ac_b_ex
.fe_group
,
2824 le16_add_cpu(&gdp
->bg_free_blocks_count
, -ac
->ac_b_ex
.fe_len
);
2825 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, ac
->ac_b_ex
.fe_group
, gdp
);
2826 spin_unlock(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
));
2827 percpu_counter_sub(&sbi
->s_freeblocks_counter
, ac
->ac_b_ex
.fe_len
);
2829 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
2832 err
= ext4_journal_dirty_metadata(handle
, gdp_bh
);
2841 * here we normalize request for locality group
2842 * Group request are normalized to s_strip size if we set the same via mount
2843 * option. If not we set it to s_mb_group_prealloc which can be configured via
2844 * /proc/fs/ext4/<partition>/group_prealloc
2846 * XXX: should we try to preallocate more than the group has now?
2848 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2850 struct super_block
*sb
= ac
->ac_sb
;
2851 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2854 if (EXT4_SB(sb
)->s_stripe
)
2855 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_stripe
;
2857 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2858 mb_debug("#%u: goal %u blocks for locality group\n",
2859 current
->pid
, ac
->ac_g_ex
.fe_len
);
2863 * Normalization means making request better in terms of
2864 * size and alignment
2866 static noinline_for_stack
void
2867 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
2868 struct ext4_allocation_request
*ar
)
2872 loff_t size
, orig_size
, start_off
;
2873 ext4_lblk_t start
, orig_start
;
2874 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
2875 struct ext4_prealloc_space
*pa
;
2877 /* do normalize only data requests, metadata requests
2878 do not need preallocation */
2879 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
2882 /* sometime caller may want exact blocks */
2883 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2886 /* caller may indicate that preallocation isn't
2887 * required (it's a tail, for example) */
2888 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
2891 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
2892 ext4_mb_normalize_group_request(ac
);
2896 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
2898 /* first, let's learn actual file size
2899 * given current request is allocated */
2900 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
2901 size
= size
<< bsbits
;
2902 if (size
< i_size_read(ac
->ac_inode
))
2903 size
= i_size_read(ac
->ac_inode
);
2905 /* max size of free chunks */
2908 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
2909 (req <= (size) || max <= (chunk_size))
2911 /* first, try to predict filesize */
2912 /* XXX: should this table be tunable? */
2914 if (size
<= 16 * 1024) {
2916 } else if (size
<= 32 * 1024) {
2918 } else if (size
<= 64 * 1024) {
2920 } else if (size
<= 128 * 1024) {
2922 } else if (size
<= 256 * 1024) {
2924 } else if (size
<= 512 * 1024) {
2926 } else if (size
<= 1024 * 1024) {
2928 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
2929 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2930 (21 - bsbits
)) << 21;
2931 size
= 2 * 1024 * 1024;
2932 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
2933 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2934 (22 - bsbits
)) << 22;
2935 size
= 4 * 1024 * 1024;
2936 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
2937 (8<<20)>>bsbits
, max
, 8 * 1024)) {
2938 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2939 (23 - bsbits
)) << 23;
2940 size
= 8 * 1024 * 1024;
2942 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
2943 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
2945 orig_size
= size
= size
>> bsbits
;
2946 orig_start
= start
= start_off
>> bsbits
;
2948 /* don't cover already allocated blocks in selected range */
2949 if (ar
->pleft
&& start
<= ar
->lleft
) {
2950 size
-= ar
->lleft
+ 1 - start
;
2951 start
= ar
->lleft
+ 1;
2953 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
2954 size
-= start
+ size
- ar
->lright
;
2958 /* check we don't cross already preallocated blocks */
2960 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
2961 unsigned long pa_end
;
2965 spin_lock(&pa
->pa_lock
);
2966 if (pa
->pa_deleted
) {
2967 spin_unlock(&pa
->pa_lock
);
2971 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
2973 /* PA must not overlap original request */
2974 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
2975 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
2977 /* skip PA normalized request doesn't overlap with */
2978 if (pa
->pa_lstart
>= end
) {
2979 spin_unlock(&pa
->pa_lock
);
2982 if (pa_end
<= start
) {
2983 spin_unlock(&pa
->pa_lock
);
2986 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
2988 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
2989 BUG_ON(pa_end
< start
);
2993 if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
2994 BUG_ON(pa
->pa_lstart
> end
);
2995 end
= pa
->pa_lstart
;
2997 spin_unlock(&pa
->pa_lock
);
3002 /* XXX: extra loop to check we really don't overlap preallocations */
3004 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3005 unsigned long pa_end
;
3006 spin_lock(&pa
->pa_lock
);
3007 if (pa
->pa_deleted
== 0) {
3008 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
3009 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3011 spin_unlock(&pa
->pa_lock
);
3015 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3016 start
> ac
->ac_o_ex
.fe_logical
) {
3017 printk(KERN_ERR
"start %lu, size %lu, fe_logical %lu\n",
3018 (unsigned long) start
, (unsigned long) size
,
3019 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3021 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3022 start
> ac
->ac_o_ex
.fe_logical
);
3023 BUG_ON(size
<= 0 || size
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3025 /* now prepare goal request */
3027 /* XXX: is it better to align blocks WRT to logical
3028 * placement or satisfy big request as is */
3029 ac
->ac_g_ex
.fe_logical
= start
;
3030 ac
->ac_g_ex
.fe_len
= size
;
3032 /* define goal start in order to merge */
3033 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3034 /* merge to the right */
3035 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3036 &ac
->ac_f_ex
.fe_group
,
3037 &ac
->ac_f_ex
.fe_start
);
3038 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3040 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3041 /* merge to the left */
3042 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3043 &ac
->ac_f_ex
.fe_group
,
3044 &ac
->ac_f_ex
.fe_start
);
3045 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3048 mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3049 (unsigned) orig_size
, (unsigned) start
);
3052 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3054 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3056 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3057 atomic_inc(&sbi
->s_bal_reqs
);
3058 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3059 if (ac
->ac_o_ex
.fe_len
>= ac
->ac_g_ex
.fe_len
)
3060 atomic_inc(&sbi
->s_bal_success
);
3061 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3062 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3063 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3064 atomic_inc(&sbi
->s_bal_goals
);
3065 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3066 atomic_inc(&sbi
->s_bal_breaks
);
3069 ext4_mb_store_history(ac
);
3073 * use blocks preallocated to inode
3075 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3076 struct ext4_prealloc_space
*pa
)
3082 /* found preallocated blocks, use them */
3083 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3084 end
= min(pa
->pa_pstart
+ pa
->pa_len
, start
+ ac
->ac_o_ex
.fe_len
);
3086 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3087 &ac
->ac_b_ex
.fe_start
);
3088 ac
->ac_b_ex
.fe_len
= len
;
3089 ac
->ac_status
= AC_STATUS_FOUND
;
3092 BUG_ON(start
< pa
->pa_pstart
);
3093 BUG_ON(start
+ len
> pa
->pa_pstart
+ pa
->pa_len
);
3094 BUG_ON(pa
->pa_free
< len
);
3097 mb_debug("use %llu/%u from inode pa %p\n", start
, len
, pa
);
3101 * use blocks preallocated to locality group
3103 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3104 struct ext4_prealloc_space
*pa
)
3106 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3107 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3108 &ac
->ac_b_ex
.fe_group
,
3109 &ac
->ac_b_ex
.fe_start
);
3110 ac
->ac_b_ex
.fe_len
= len
;
3111 ac
->ac_status
= AC_STATUS_FOUND
;
3114 /* we don't correct pa_pstart or pa_plen here to avoid
3115 * possible race when the group is being loaded concurrently
3116 * instead we correct pa later, after blocks are marked
3117 * in on-disk bitmap -- see ext4_mb_release_context()
3118 * Other CPUs are prevented from allocating from this pa by lg_mutex
3120 mb_debug("use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3124 * search goal blocks in preallocated space
3126 static noinline_for_stack
int
3127 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3129 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3130 struct ext4_locality_group
*lg
;
3131 struct ext4_prealloc_space
*pa
;
3133 /* only data can be preallocated */
3134 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3137 /* first, try per-file preallocation */
3139 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3141 /* all fields in this condition don't change,
3142 * so we can skip locking for them */
3143 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3144 ac
->ac_o_ex
.fe_logical
>= pa
->pa_lstart
+ pa
->pa_len
)
3147 /* found preallocated blocks, use them */
3148 spin_lock(&pa
->pa_lock
);
3149 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3150 atomic_inc(&pa
->pa_count
);
3151 ext4_mb_use_inode_pa(ac
, pa
);
3152 spin_unlock(&pa
->pa_lock
);
3153 ac
->ac_criteria
= 10;
3157 spin_unlock(&pa
->pa_lock
);
3161 /* can we use group allocation? */
3162 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3165 /* inode may have no locality group for some reason */
3171 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
, pa_inode_list
) {
3172 spin_lock(&pa
->pa_lock
);
3173 if (pa
->pa_deleted
== 0 && pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3174 atomic_inc(&pa
->pa_count
);
3175 ext4_mb_use_group_pa(ac
, pa
);
3176 spin_unlock(&pa
->pa_lock
);
3177 ac
->ac_criteria
= 20;
3181 spin_unlock(&pa
->pa_lock
);
3189 * the function goes through all preallocation in this group and marks them
3190 * used in in-core bitmap. buddy must be generated from this bitmap
3191 * Need to be called with ext4 group lock (ext4_lock_group)
3193 static void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3196 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3197 struct ext4_prealloc_space
*pa
;
3198 struct list_head
*cur
;
3199 ext4_group_t groupnr
;
3200 ext4_grpblk_t start
;
3201 int preallocated
= 0;
3205 /* all form of preallocation discards first load group,
3206 * so the only competing code is preallocation use.
3207 * we don't need any locking here
3208 * notice we do NOT ignore preallocations with pa_deleted
3209 * otherwise we could leave used blocks available for
3210 * allocation in buddy when concurrent ext4_mb_put_pa()
3211 * is dropping preallocation
3213 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3214 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3215 spin_lock(&pa
->pa_lock
);
3216 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3219 spin_unlock(&pa
->pa_lock
);
3220 if (unlikely(len
== 0))
3222 BUG_ON(groupnr
!= group
);
3223 mb_set_bits(sb_bgl_lock(EXT4_SB(sb
), group
),
3224 bitmap
, start
, len
);
3225 preallocated
+= len
;
3228 mb_debug("prellocated %u for group %lu\n", preallocated
, group
);
3231 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3233 struct ext4_prealloc_space
*pa
;
3234 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3235 kmem_cache_free(ext4_pspace_cachep
, pa
);
3239 * drops a reference to preallocated space descriptor
3240 * if this was the last reference and the space is consumed
3242 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3243 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3247 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0)
3250 /* in this short window concurrent discard can set pa_deleted */
3251 spin_lock(&pa
->pa_lock
);
3252 if (pa
->pa_deleted
== 1) {
3253 spin_unlock(&pa
->pa_lock
);
3258 spin_unlock(&pa
->pa_lock
);
3260 /* -1 is to protect from crossing allocation group */
3261 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
- 1, &grp
, NULL
);
3266 * P1 (buddy init) P2 (regular allocation)
3267 * find block B in PA
3268 * copy on-disk bitmap to buddy
3269 * mark B in on-disk bitmap
3270 * drop PA from group
3271 * mark all PAs in buddy
3273 * thus, P1 initializes buddy with B available. to prevent this
3274 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3277 ext4_lock_group(sb
, grp
);
3278 list_del(&pa
->pa_group_list
);
3279 ext4_unlock_group(sb
, grp
);
3281 spin_lock(pa
->pa_obj_lock
);
3282 list_del_rcu(&pa
->pa_inode_list
);
3283 spin_unlock(pa
->pa_obj_lock
);
3285 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3289 * creates new preallocated space for given inode
3291 static noinline_for_stack
int
3292 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3294 struct super_block
*sb
= ac
->ac_sb
;
3295 struct ext4_prealloc_space
*pa
;
3296 struct ext4_group_info
*grp
;
3297 struct ext4_inode_info
*ei
;
3299 /* preallocate only when found space is larger then requested */
3300 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3301 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3302 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3304 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3308 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3314 /* we can't allocate as much as normalizer wants.
3315 * so, found space must get proper lstart
3316 * to cover original request */
3317 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3318 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3320 /* we're limited by original request in that
3321 * logical block must be covered any way
3322 * winl is window we can move our chunk within */
3323 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3325 /* also, we should cover whole original request */
3326 wins
= ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
;
3328 /* the smallest one defines real window */
3329 win
= min(winl
, wins
);
3331 offs
= ac
->ac_o_ex
.fe_logical
% ac
->ac_b_ex
.fe_len
;
3332 if (offs
&& offs
< win
)
3335 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
- win
;
3336 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3337 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3340 /* preallocation can change ac_b_ex, thus we store actually
3341 * allocated blocks for history */
3342 ac
->ac_f_ex
= ac
->ac_b_ex
;
3344 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3345 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3346 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3347 pa
->pa_free
= pa
->pa_len
;
3348 atomic_set(&pa
->pa_count
, 1);
3349 spin_lock_init(&pa
->pa_lock
);
3353 mb_debug("new inode pa %p: %llu/%u for %u\n", pa
,
3354 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3356 ext4_mb_use_inode_pa(ac
, pa
);
3357 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3359 ei
= EXT4_I(ac
->ac_inode
);
3360 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3362 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3363 pa
->pa_inode
= ac
->ac_inode
;
3365 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3366 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3367 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3369 spin_lock(pa
->pa_obj_lock
);
3370 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3371 spin_unlock(pa
->pa_obj_lock
);
3377 * creates new preallocated space for locality group inodes belongs to
3379 static noinline_for_stack
int
3380 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3382 struct super_block
*sb
= ac
->ac_sb
;
3383 struct ext4_locality_group
*lg
;
3384 struct ext4_prealloc_space
*pa
;
3385 struct ext4_group_info
*grp
;
3387 /* preallocate only when found space is larger then requested */
3388 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3389 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3390 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3392 BUG_ON(ext4_pspace_cachep
== NULL
);
3393 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3397 /* preallocation can change ac_b_ex, thus we store actually
3398 * allocated blocks for history */
3399 ac
->ac_f_ex
= ac
->ac_b_ex
;
3401 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3402 pa
->pa_lstart
= pa
->pa_pstart
;
3403 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3404 pa
->pa_free
= pa
->pa_len
;
3405 atomic_set(&pa
->pa_count
, 1);
3406 spin_lock_init(&pa
->pa_lock
);
3410 mb_debug("new group pa %p: %llu/%u for %u\n", pa
,
3411 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3413 ext4_mb_use_group_pa(ac
, pa
);
3414 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3416 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3420 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3421 pa
->pa_inode
= NULL
;
3423 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3424 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3425 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3427 spin_lock(pa
->pa_obj_lock
);
3428 list_add_tail_rcu(&pa
->pa_inode_list
, &lg
->lg_prealloc_list
);
3429 spin_unlock(pa
->pa_obj_lock
);
3434 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3438 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3439 err
= ext4_mb_new_group_pa(ac
);
3441 err
= ext4_mb_new_inode_pa(ac
);
3446 * finds all unused blocks in on-disk bitmap, frees them in
3447 * in-core bitmap and buddy.
3448 * @pa must be unlinked from inode and group lists, so that
3449 * nobody else can find/use it.
3450 * the caller MUST hold group/inode locks.
3451 * TODO: optimize the case when there are no in-core structures yet
3453 static noinline_for_stack
int
3454 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3455 struct ext4_prealloc_space
*pa
,
3456 struct ext4_allocation_context
*ac
)
3458 struct super_block
*sb
= e4b
->bd_sb
;
3459 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3468 BUG_ON(pa
->pa_deleted
== 0);
3469 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3470 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3471 end
= bit
+ pa
->pa_len
;
3475 ac
->ac_inode
= pa
->pa_inode
;
3476 ac
->ac_op
= EXT4_MB_HISTORY_DISCARD
;
3480 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3483 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3484 start
= group
* EXT4_BLOCKS_PER_GROUP(sb
) + bit
+
3485 le32_to_cpu(sbi
->s_es
->s_first_data_block
);
3486 mb_debug(" free preallocated %u/%u in group %u\n",
3487 (unsigned) start
, (unsigned) next
- bit
,
3492 ac
->ac_b_ex
.fe_group
= group
;
3493 ac
->ac_b_ex
.fe_start
= bit
;
3494 ac
->ac_b_ex
.fe_len
= next
- bit
;
3495 ac
->ac_b_ex
.fe_logical
= 0;
3496 ext4_mb_store_history(ac
);
3499 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3502 if (free
!= pa
->pa_free
) {
3503 printk(KERN_CRIT
"pa %p: logic %lu, phys. %lu, len %lu\n",
3504 pa
, (unsigned long) pa
->pa_lstart
,
3505 (unsigned long) pa
->pa_pstart
,
3506 (unsigned long) pa
->pa_len
);
3507 ext4_error(sb
, __func__
, "free %u, pa_free %u\n",
3510 * pa is already deleted so we use the value obtained
3511 * from the bitmap and continue.
3514 atomic_add(free
, &sbi
->s_mb_discarded
);
3519 static noinline_for_stack
int
3520 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3521 struct ext4_prealloc_space
*pa
,
3522 struct ext4_allocation_context
*ac
)
3524 struct super_block
*sb
= e4b
->bd_sb
;
3529 ac
->ac_op
= EXT4_MB_HISTORY_DISCARD
;
3531 BUG_ON(pa
->pa_deleted
== 0);
3532 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3533 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3534 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3535 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3539 ac
->ac_inode
= NULL
;
3540 ac
->ac_b_ex
.fe_group
= group
;
3541 ac
->ac_b_ex
.fe_start
= bit
;
3542 ac
->ac_b_ex
.fe_len
= pa
->pa_len
;
3543 ac
->ac_b_ex
.fe_logical
= 0;
3544 ext4_mb_store_history(ac
);
3551 * releases all preallocations in given group
3553 * first, we need to decide discard policy:
3554 * - when do we discard
3556 * - how many do we discard
3557 * 1) how many requested
3559 static noinline_for_stack
int
3560 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3561 ext4_group_t group
, int needed
)
3563 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3564 struct buffer_head
*bitmap_bh
= NULL
;
3565 struct ext4_prealloc_space
*pa
, *tmp
;
3566 struct ext4_allocation_context
*ac
;
3567 struct list_head list
;
3568 struct ext4_buddy e4b
;
3573 mb_debug("discard preallocation for group %lu\n", group
);
3575 if (list_empty(&grp
->bb_prealloc_list
))
3578 bitmap_bh
= read_block_bitmap(sb
, group
);
3579 if (bitmap_bh
== NULL
) {
3580 /* error handling here */
3581 ext4_mb_release_desc(&e4b
);
3582 BUG_ON(bitmap_bh
== NULL
);
3585 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3586 BUG_ON(err
!= 0); /* error handling here */
3589 needed
= EXT4_BLOCKS_PER_GROUP(sb
) + 1;
3591 grp
= ext4_get_group_info(sb
, group
);
3592 INIT_LIST_HEAD(&list
);
3594 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3596 ext4_lock_group(sb
, group
);
3597 list_for_each_entry_safe(pa
, tmp
,
3598 &grp
->bb_prealloc_list
, pa_group_list
) {
3599 spin_lock(&pa
->pa_lock
);
3600 if (atomic_read(&pa
->pa_count
)) {
3601 spin_unlock(&pa
->pa_lock
);
3605 if (pa
->pa_deleted
) {
3606 spin_unlock(&pa
->pa_lock
);
3610 /* seems this one can be freed ... */
3613 /* we can trust pa_free ... */
3614 free
+= pa
->pa_free
;
3616 spin_unlock(&pa
->pa_lock
);
3618 list_del(&pa
->pa_group_list
);
3619 list_add(&pa
->u
.pa_tmp_list
, &list
);
3622 /* if we still need more blocks and some PAs were used, try again */
3623 if (free
< needed
&& busy
) {
3625 ext4_unlock_group(sb
, group
);
3627 * Yield the CPU here so that we don't get soft lockup
3628 * in non preempt case.
3634 /* found anything to free? */
3635 if (list_empty(&list
)) {
3640 /* now free all selected PAs */
3641 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3643 /* remove from object (inode or locality group) */
3644 spin_lock(pa
->pa_obj_lock
);
3645 list_del_rcu(&pa
->pa_inode_list
);
3646 spin_unlock(pa
->pa_obj_lock
);
3649 ext4_mb_release_group_pa(&e4b
, pa
, ac
);
3651 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3653 list_del(&pa
->u
.pa_tmp_list
);
3654 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3658 ext4_unlock_group(sb
, group
);
3660 kmem_cache_free(ext4_ac_cachep
, ac
);
3661 ext4_mb_release_desc(&e4b
);
3667 * releases all non-used preallocated blocks for given inode
3669 * It's important to discard preallocations under i_data_sem
3670 * We don't want another block to be served from the prealloc
3671 * space when we are discarding the inode prealloc space.
3673 * FIXME!! Make sure it is valid at all the call sites
3675 void ext4_mb_discard_inode_preallocations(struct inode
*inode
)
3677 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3678 struct super_block
*sb
= inode
->i_sb
;
3679 struct buffer_head
*bitmap_bh
= NULL
;
3680 struct ext4_prealloc_space
*pa
, *tmp
;
3681 struct ext4_allocation_context
*ac
;
3682 ext4_group_t group
= 0;
3683 struct list_head list
;
3684 struct ext4_buddy e4b
;
3687 if (!test_opt(sb
, MBALLOC
) || !S_ISREG(inode
->i_mode
)) {
3688 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3692 mb_debug("discard preallocation for inode %lu\n", inode
->i_ino
);
3694 INIT_LIST_HEAD(&list
);
3696 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3698 /* first, collect all pa's in the inode */
3699 spin_lock(&ei
->i_prealloc_lock
);
3700 while (!list_empty(&ei
->i_prealloc_list
)) {
3701 pa
= list_entry(ei
->i_prealloc_list
.next
,
3702 struct ext4_prealloc_space
, pa_inode_list
);
3703 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3704 spin_lock(&pa
->pa_lock
);
3705 if (atomic_read(&pa
->pa_count
)) {
3706 /* this shouldn't happen often - nobody should
3707 * use preallocation while we're discarding it */
3708 spin_unlock(&pa
->pa_lock
);
3709 spin_unlock(&ei
->i_prealloc_lock
);
3710 printk(KERN_ERR
"uh-oh! used pa while discarding\n");
3712 schedule_timeout_uninterruptible(HZ
);
3716 if (pa
->pa_deleted
== 0) {
3718 spin_unlock(&pa
->pa_lock
);
3719 list_del_rcu(&pa
->pa_inode_list
);
3720 list_add(&pa
->u
.pa_tmp_list
, &list
);
3724 /* someone is deleting pa right now */
3725 spin_unlock(&pa
->pa_lock
);
3726 spin_unlock(&ei
->i_prealloc_lock
);
3728 /* we have to wait here because pa_deleted
3729 * doesn't mean pa is already unlinked from
3730 * the list. as we might be called from
3731 * ->clear_inode() the inode will get freed
3732 * and concurrent thread which is unlinking
3733 * pa from inode's list may access already
3734 * freed memory, bad-bad-bad */
3736 /* XXX: if this happens too often, we can
3737 * add a flag to force wait only in case
3738 * of ->clear_inode(), but not in case of
3739 * regular truncate */
3740 schedule_timeout_uninterruptible(HZ
);
3743 spin_unlock(&ei
->i_prealloc_lock
);
3745 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3746 BUG_ON(pa
->pa_linear
!= 0);
3747 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
3749 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3750 BUG_ON(err
!= 0); /* error handling here */
3752 bitmap_bh
= read_block_bitmap(sb
, group
);
3753 if (bitmap_bh
== NULL
) {
3754 /* error handling here */
3755 ext4_mb_release_desc(&e4b
);
3756 BUG_ON(bitmap_bh
== NULL
);
3759 ext4_lock_group(sb
, group
);
3760 list_del(&pa
->pa_group_list
);
3761 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3762 ext4_unlock_group(sb
, group
);
3764 ext4_mb_release_desc(&e4b
);
3767 list_del(&pa
->u
.pa_tmp_list
);
3768 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3771 kmem_cache_free(ext4_ac_cachep
, ac
);
3775 * finds all preallocated spaces and return blocks being freed to them
3776 * if preallocated space becomes full (no block is used from the space)
3777 * then the function frees space in buddy
3778 * XXX: at the moment, truncate (which is the only way to free blocks)
3779 * discards all preallocations
3781 static void ext4_mb_return_to_preallocation(struct inode
*inode
,
3782 struct ext4_buddy
*e4b
,
3783 sector_t block
, int count
)
3785 BUG_ON(!list_empty(&EXT4_I(inode
)->i_prealloc_list
));
3788 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3790 struct super_block
*sb
= ac
->ac_sb
;
3793 printk(KERN_ERR
"EXT4-fs: Can't allocate:"
3794 " Allocation context details:\n");
3795 printk(KERN_ERR
"EXT4-fs: status %d flags %d\n",
3796 ac
->ac_status
, ac
->ac_flags
);
3797 printk(KERN_ERR
"EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
3798 "best %lu/%lu/%lu@%lu cr %d\n",
3799 (unsigned long)ac
->ac_o_ex
.fe_group
,
3800 (unsigned long)ac
->ac_o_ex
.fe_start
,
3801 (unsigned long)ac
->ac_o_ex
.fe_len
,
3802 (unsigned long)ac
->ac_o_ex
.fe_logical
,
3803 (unsigned long)ac
->ac_g_ex
.fe_group
,
3804 (unsigned long)ac
->ac_g_ex
.fe_start
,
3805 (unsigned long)ac
->ac_g_ex
.fe_len
,
3806 (unsigned long)ac
->ac_g_ex
.fe_logical
,
3807 (unsigned long)ac
->ac_b_ex
.fe_group
,
3808 (unsigned long)ac
->ac_b_ex
.fe_start
,
3809 (unsigned long)ac
->ac_b_ex
.fe_len
,
3810 (unsigned long)ac
->ac_b_ex
.fe_logical
,
3811 (int)ac
->ac_criteria
);
3812 printk(KERN_ERR
"EXT4-fs: %lu scanned, %d found\n", ac
->ac_ex_scanned
,
3814 printk(KERN_ERR
"EXT4-fs: groups: \n");
3815 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
; i
++) {
3816 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
3817 struct ext4_prealloc_space
*pa
;
3818 ext4_grpblk_t start
;
3819 struct list_head
*cur
;
3820 ext4_lock_group(sb
, i
);
3821 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3822 pa
= list_entry(cur
, struct ext4_prealloc_space
,
3824 spin_lock(&pa
->pa_lock
);
3825 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3827 spin_unlock(&pa
->pa_lock
);
3828 printk(KERN_ERR
"PA:%lu:%d:%u \n", i
,
3831 ext4_unlock_group(sb
, i
);
3833 if (grp
->bb_free
== 0)
3835 printk(KERN_ERR
"%lu: %d/%d \n",
3836 i
, grp
->bb_free
, grp
->bb_fragments
);
3838 printk(KERN_ERR
"\n");
3841 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3848 * We use locality group preallocation for small size file. The size of the
3849 * file is determined by the current size or the resulting size after
3850 * allocation which ever is larger
3852 * One can tune this size via /proc/fs/ext4/<partition>/stream_req
3854 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
3856 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3857 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3860 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3863 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
3864 isize
= i_size_read(ac
->ac_inode
) >> bsbits
;
3865 size
= max(size
, isize
);
3867 /* don't use group allocation for large files */
3868 if (size
>= sbi
->s_mb_stream_request
)
3871 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3874 BUG_ON(ac
->ac_lg
!= NULL
);
3876 * locality group prealloc space are per cpu. The reason for having
3877 * per cpu locality group is to reduce the contention between block
3878 * request from multiple CPUs.
3880 ac
->ac_lg
= &sbi
->s_locality_groups
[get_cpu()];
3883 /* we're going to use group allocation */
3884 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
3886 /* serialize all allocations in the group */
3887 mutex_lock(&ac
->ac_lg
->lg_mutex
);
3890 static noinline_for_stack
int
3891 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
3892 struct ext4_allocation_request
*ar
)
3894 struct super_block
*sb
= ar
->inode
->i_sb
;
3895 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3896 struct ext4_super_block
*es
= sbi
->s_es
;
3900 ext4_grpblk_t block
;
3902 /* we can't allocate > group size */
3905 /* just a dirty hack to filter too big requests */
3906 if (len
>= EXT4_BLOCKS_PER_GROUP(sb
) - 10)
3907 len
= EXT4_BLOCKS_PER_GROUP(sb
) - 10;
3909 /* start searching from the goal */
3911 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
3912 goal
>= ext4_blocks_count(es
))
3913 goal
= le32_to_cpu(es
->s_first_data_block
);
3914 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
3916 /* set up allocation goals */
3917 ac
->ac_b_ex
.fe_logical
= ar
->logical
;
3918 ac
->ac_b_ex
.fe_group
= 0;
3919 ac
->ac_b_ex
.fe_start
= 0;
3920 ac
->ac_b_ex
.fe_len
= 0;
3921 ac
->ac_status
= AC_STATUS_CONTINUE
;
3922 ac
->ac_groups_scanned
= 0;
3923 ac
->ac_ex_scanned
= 0;
3926 ac
->ac_inode
= ar
->inode
;
3927 ac
->ac_o_ex
.fe_logical
= ar
->logical
;
3928 ac
->ac_o_ex
.fe_group
= group
;
3929 ac
->ac_o_ex
.fe_start
= block
;
3930 ac
->ac_o_ex
.fe_len
= len
;
3931 ac
->ac_g_ex
.fe_logical
= ar
->logical
;
3932 ac
->ac_g_ex
.fe_group
= group
;
3933 ac
->ac_g_ex
.fe_start
= block
;
3934 ac
->ac_g_ex
.fe_len
= len
;
3935 ac
->ac_f_ex
.fe_len
= 0;
3936 ac
->ac_flags
= ar
->flags
;
3938 ac
->ac_criteria
= 0;
3940 ac
->ac_bitmap_page
= NULL
;
3941 ac
->ac_buddy_page
= NULL
;
3944 /* we have to define context: we'll we work with a file or
3945 * locality group. this is a policy, actually */
3946 ext4_mb_group_or_file(ac
);
3948 mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
3949 "left: %u/%u, right %u/%u to %swritable\n",
3950 (unsigned) ar
->len
, (unsigned) ar
->logical
,
3951 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
3952 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
3953 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
3954 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
3960 * release all resource we used in allocation
3962 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
3965 if (ac
->ac_pa
->pa_linear
) {
3966 /* see comment in ext4_mb_use_group_pa() */
3967 spin_lock(&ac
->ac_pa
->pa_lock
);
3968 ac
->ac_pa
->pa_pstart
+= ac
->ac_b_ex
.fe_len
;
3969 ac
->ac_pa
->pa_lstart
+= ac
->ac_b_ex
.fe_len
;
3970 ac
->ac_pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
3971 ac
->ac_pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
3972 spin_unlock(&ac
->ac_pa
->pa_lock
);
3974 ext4_mb_put_pa(ac
, ac
->ac_sb
, ac
->ac_pa
);
3976 if (ac
->ac_bitmap_page
)
3977 page_cache_release(ac
->ac_bitmap_page
);
3978 if (ac
->ac_buddy_page
)
3979 page_cache_release(ac
->ac_buddy_page
);
3980 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3981 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
3982 ext4_mb_collect_stats(ac
);
3986 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
3992 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
&& needed
> 0; i
++) {
3993 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4002 * Main entry point into mballoc to allocate blocks
4003 * it tries to use preallocation first, then falls back
4004 * to usual allocation
4006 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4007 struct ext4_allocation_request
*ar
, int *errp
)
4009 struct ext4_allocation_context
*ac
= NULL
;
4010 struct ext4_sb_info
*sbi
;
4011 struct super_block
*sb
;
4012 ext4_fsblk_t block
= 0;
4016 sb
= ar
->inode
->i_sb
;
4019 if (!test_opt(sb
, MBALLOC
)) {
4020 block
= ext4_new_blocks_old(handle
, ar
->inode
, ar
->goal
,
4025 while (ar
->len
&& DQUOT_ALLOC_BLOCK(ar
->inode
, ar
->len
)) {
4026 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4035 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4041 ext4_mb_poll_new_transaction(sb
, handle
);
4043 *errp
= ext4_mb_initialize_context(ac
, ar
);
4049 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4050 if (!ext4_mb_use_preallocated(ac
)) {
4052 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4053 ext4_mb_normalize_request(ac
, ar
);
4055 /* allocate space in core */
4056 ext4_mb_regular_allocator(ac
);
4058 /* as we've just preallocated more space than
4059 * user requested orinally, we store allocated
4060 * space in a special descriptor */
4061 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4062 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4063 ext4_mb_new_preallocation(ac
);
4066 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4067 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
);
4068 if (*errp
== -EAGAIN
) {
4069 ac
->ac_b_ex
.fe_group
= 0;
4070 ac
->ac_b_ex
.fe_start
= 0;
4071 ac
->ac_b_ex
.fe_len
= 0;
4072 ac
->ac_status
= AC_STATUS_CONTINUE
;
4075 ac
->ac_b_ex
.fe_len
= 0;
4077 ext4_mb_show_ac(ac
);
4079 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4080 ar
->len
= ac
->ac_b_ex
.fe_len
;
4083 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4087 ac
->ac_b_ex
.fe_len
= 0;
4089 ext4_mb_show_ac(ac
);
4092 ext4_mb_release_context(ac
);
4095 if (ar
->len
< inquota
)
4096 DQUOT_FREE_BLOCK(ar
->inode
, inquota
- ar
->len
);
4098 kmem_cache_free(ext4_ac_cachep
, ac
);
4101 static void ext4_mb_poll_new_transaction(struct super_block
*sb
,
4104 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4106 if (sbi
->s_last_transaction
== handle
->h_transaction
->t_tid
)
4109 /* new transaction! time to close last one and free blocks for
4110 * committed transaction. we know that only transaction can be
4111 * active, so previos transaction can be being logged and we
4112 * know that transaction before previous is known to be already
4113 * logged. this means that now we may free blocks freed in all
4114 * transactions before previous one. hope I'm clear enough ... */
4116 spin_lock(&sbi
->s_md_lock
);
4117 if (sbi
->s_last_transaction
!= handle
->h_transaction
->t_tid
) {
4118 mb_debug("new transaction %lu, old %lu\n",
4119 (unsigned long) handle
->h_transaction
->t_tid
,
4120 (unsigned long) sbi
->s_last_transaction
);
4121 list_splice_init(&sbi
->s_closed_transaction
,
4122 &sbi
->s_committed_transaction
);
4123 list_splice_init(&sbi
->s_active_transaction
,
4124 &sbi
->s_closed_transaction
);
4125 sbi
->s_last_transaction
= handle
->h_transaction
->t_tid
;
4127 spin_unlock(&sbi
->s_md_lock
);
4129 ext4_mb_free_committed_blocks(sb
);
4132 static noinline_for_stack
int
4133 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4134 ext4_group_t group
, ext4_grpblk_t block
, int count
)
4136 struct ext4_group_info
*db
= e4b
->bd_info
;
4137 struct super_block
*sb
= e4b
->bd_sb
;
4138 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4139 struct ext4_free_metadata
*md
;
4142 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4143 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4145 ext4_lock_group(sb
, group
);
4146 for (i
= 0; i
< count
; i
++) {
4148 if (md
&& db
->bb_tid
!= handle
->h_transaction
->t_tid
) {
4149 db
->bb_md_cur
= NULL
;
4154 ext4_unlock_group(sb
, group
);
4155 md
= kmalloc(sizeof(*md
), GFP_NOFS
);
4161 ext4_lock_group(sb
, group
);
4162 if (db
->bb_md_cur
== NULL
) {
4163 spin_lock(&sbi
->s_md_lock
);
4164 list_add(&md
->list
, &sbi
->s_active_transaction
);
4165 spin_unlock(&sbi
->s_md_lock
);
4166 /* protect buddy cache from being freed,
4167 * otherwise we'll refresh it from
4168 * on-disk bitmap and lose not-yet-available
4170 page_cache_get(e4b
->bd_buddy_page
);
4171 page_cache_get(e4b
->bd_bitmap_page
);
4173 db
->bb_tid
= handle
->h_transaction
->t_tid
;
4174 mb_debug("new md 0x%p for group %lu\n",
4182 BUG_ON(md
->num
>= EXT4_BB_MAX_BLOCKS
);
4183 md
->blocks
[md
->num
] = block
+ i
;
4185 if (md
->num
== EXT4_BB_MAX_BLOCKS
) {
4186 /* no more space, put full container on a sb's list */
4187 db
->bb_md_cur
= NULL
;
4190 ext4_unlock_group(sb
, group
);
4195 * Main entry point into mballoc to free blocks
4197 void ext4_mb_free_blocks(handle_t
*handle
, struct inode
*inode
,
4198 unsigned long block
, unsigned long count
,
4199 int metadata
, unsigned long *freed
)
4201 struct buffer_head
*bitmap_bh
= NULL
;
4202 struct super_block
*sb
= inode
->i_sb
;
4203 struct ext4_allocation_context
*ac
= NULL
;
4204 struct ext4_group_desc
*gdp
;
4205 struct ext4_super_block
*es
;
4206 unsigned long overflow
;
4208 struct buffer_head
*gd_bh
;
4209 ext4_group_t block_group
;
4210 struct ext4_sb_info
*sbi
;
4211 struct ext4_buddy e4b
;
4217 ext4_mb_poll_new_transaction(sb
, handle
);
4220 es
= EXT4_SB(sb
)->s_es
;
4221 if (block
< le32_to_cpu(es
->s_first_data_block
) ||
4222 block
+ count
< block
||
4223 block
+ count
> ext4_blocks_count(es
)) {
4224 ext4_error(sb
, __func__
,
4225 "Freeing blocks not in datazone - "
4226 "block = %lu, count = %lu", block
, count
);
4230 ext4_debug("freeing block %lu\n", block
);
4232 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4234 ac
->ac_op
= EXT4_MB_HISTORY_FREE
;
4235 ac
->ac_inode
= inode
;
4241 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4244 * Check to see if we are freeing blocks across a group
4247 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4248 overflow
= bit
+ count
- EXT4_BLOCKS_PER_GROUP(sb
);
4251 bitmap_bh
= read_block_bitmap(sb
, block_group
);
4254 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4258 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4259 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4260 in_range(block
, ext4_inode_table(sb
, gdp
),
4261 EXT4_SB(sb
)->s_itb_per_group
) ||
4262 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4263 EXT4_SB(sb
)->s_itb_per_group
)) {
4265 ext4_error(sb
, __func__
,
4266 "Freeing blocks in system zone - "
4267 "Block = %lu, count = %lu", block
, count
);
4268 /* err = 0. ext4_std_error should be a no op */
4272 BUFFER_TRACE(bitmap_bh
, "getting write access");
4273 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4278 * We are about to modify some metadata. Call the journal APIs
4279 * to unshare ->b_data if a currently-committing transaction is
4282 BUFFER_TRACE(gd_bh
, "get_write_access");
4283 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4287 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4291 #ifdef AGGRESSIVE_CHECK
4294 for (i
= 0; i
< count
; i
++)
4295 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4298 mb_clear_bits(sb_bgl_lock(sbi
, block_group
), bitmap_bh
->b_data
,
4301 /* We dirtied the bitmap block */
4302 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4303 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
4306 ac
->ac_b_ex
.fe_group
= block_group
;
4307 ac
->ac_b_ex
.fe_start
= bit
;
4308 ac
->ac_b_ex
.fe_len
= count
;
4309 ext4_mb_store_history(ac
);
4313 /* blocks being freed are metadata. these blocks shouldn't
4314 * be used until this transaction is committed */
4315 ext4_mb_free_metadata(handle
, &e4b
, block_group
, bit
, count
);
4317 ext4_lock_group(sb
, block_group
);
4318 err
= mb_free_blocks(inode
, &e4b
, bit
, count
);
4319 ext4_mb_return_to_preallocation(inode
, &e4b
, block
, count
);
4320 ext4_unlock_group(sb
, block_group
);
4324 spin_lock(sb_bgl_lock(sbi
, block_group
));
4325 le16_add_cpu(&gdp
->bg_free_blocks_count
, count
);
4326 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, block_group
, gdp
);
4327 spin_unlock(sb_bgl_lock(sbi
, block_group
));
4328 percpu_counter_add(&sbi
->s_freeblocks_counter
, count
);
4330 ext4_mb_release_desc(&e4b
);
4334 /* And the group descriptor block */
4335 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4336 ret
= ext4_journal_dirty_metadata(handle
, gd_bh
);
4340 if (overflow
&& !err
) {
4349 ext4_std_error(sb
, err
);
4351 kmem_cache_free(ext4_ac_cachep
, ac
);