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
]))
813 first_block
= page
->index
* blocks_per_page
;
814 for (i
= 0; i
< blocks_per_page
; i
++) {
816 struct ext4_group_info
*grinfo
;
818 group
= (first_block
+ i
) >> 1;
819 if (group
>= EXT4_SB(sb
)->s_groups_count
)
823 * data carry information regarding this
824 * particular group in the format specified
828 data
= page_address(page
) + (i
* blocksize
);
829 bitmap
= bh
[group
- first_group
]->b_data
;
832 * We place the buddy block and bitmap block
835 if ((first_block
+ i
) & 1) {
836 /* this is block of buddy */
837 BUG_ON(incore
== NULL
);
838 mb_debug("put buddy for group %u in page %lu/%x\n",
839 group
, page
->index
, i
* blocksize
);
840 memset(data
, 0xff, blocksize
);
841 grinfo
= ext4_get_group_info(sb
, group
);
842 grinfo
->bb_fragments
= 0;
843 memset(grinfo
->bb_counters
, 0,
844 sizeof(unsigned short)*(sb
->s_blocksize_bits
+2));
846 * incore got set to the group block bitmap below
848 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
851 /* this is block of bitmap */
852 BUG_ON(incore
!= NULL
);
853 mb_debug("put bitmap for group %u in page %lu/%x\n",
854 group
, page
->index
, i
* blocksize
);
856 /* see comments in ext4_mb_put_pa() */
857 ext4_lock_group(sb
, group
);
858 memcpy(data
, bitmap
, blocksize
);
860 /* mark all preallocated blks used in in-core bitmap */
861 ext4_mb_generate_from_pa(sb
, data
, group
);
862 ext4_unlock_group(sb
, group
);
864 /* set incore so that the buddy information can be
865 * generated using this
870 SetPageUptodate(page
);
874 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
882 static noinline_for_stack
int
883 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
884 struct ext4_buddy
*e4b
)
886 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
887 struct inode
*inode
= sbi
->s_buddy_cache
;
894 mb_debug("load group %lu\n", group
);
896 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
898 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
899 e4b
->bd_info
= ext4_get_group_info(sb
, group
);
901 e4b
->bd_group
= group
;
902 e4b
->bd_buddy_page
= NULL
;
903 e4b
->bd_bitmap_page
= NULL
;
906 * the buddy cache inode stores the block bitmap
907 * and buddy information in consecutive blocks.
908 * So for each group we need two blocks.
911 pnum
= block
/ blocks_per_page
;
912 poff
= block
% blocks_per_page
;
914 /* we could use find_or_create_page(), but it locks page
915 * what we'd like to avoid in fast path ... */
916 page
= find_get_page(inode
->i_mapping
, pnum
);
917 if (page
== NULL
|| !PageUptodate(page
)) {
919 page_cache_release(page
);
920 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
922 BUG_ON(page
->mapping
!= inode
->i_mapping
);
923 if (!PageUptodate(page
)) {
924 ext4_mb_init_cache(page
, NULL
);
925 mb_cmp_bitmaps(e4b
, page_address(page
) +
926 (poff
* sb
->s_blocksize
));
931 if (page
== NULL
|| !PageUptodate(page
))
933 e4b
->bd_bitmap_page
= page
;
934 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
935 mark_page_accessed(page
);
938 pnum
= block
/ blocks_per_page
;
939 poff
= block
% blocks_per_page
;
941 page
= find_get_page(inode
->i_mapping
, pnum
);
942 if (page
== NULL
|| !PageUptodate(page
)) {
944 page_cache_release(page
);
945 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
947 BUG_ON(page
->mapping
!= inode
->i_mapping
);
948 if (!PageUptodate(page
))
949 ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
954 if (page
== NULL
|| !PageUptodate(page
))
956 e4b
->bd_buddy_page
= page
;
957 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
958 mark_page_accessed(page
);
960 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
961 BUG_ON(e4b
->bd_buddy_page
== NULL
);
966 if (e4b
->bd_bitmap_page
)
967 page_cache_release(e4b
->bd_bitmap_page
);
968 if (e4b
->bd_buddy_page
)
969 page_cache_release(e4b
->bd_buddy_page
);
970 e4b
->bd_buddy
= NULL
;
971 e4b
->bd_bitmap
= NULL
;
975 static void ext4_mb_release_desc(struct ext4_buddy
*e4b
)
977 if (e4b
->bd_bitmap_page
)
978 page_cache_release(e4b
->bd_bitmap_page
);
979 if (e4b
->bd_buddy_page
)
980 page_cache_release(e4b
->bd_buddy_page
);
984 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
989 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
990 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
992 bb
= EXT4_MB_BUDDY(e4b
);
993 while (order
<= e4b
->bd_blkbits
+ 1) {
995 if (!mb_test_bit(block
, bb
)) {
996 /* this block is part of buddy of order 'order' */
999 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1005 static void mb_clear_bits(spinlock_t
*lock
, void *bm
, int cur
, int len
)
1011 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1012 /* fast path: clear whole word at once */
1013 addr
= bm
+ (cur
>> 3);
1018 mb_clear_bit_atomic(lock
, cur
, bm
);
1023 static void mb_set_bits(spinlock_t
*lock
, void *bm
, int cur
, int len
)
1029 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1030 /* fast path: set whole word at once */
1031 addr
= bm
+ (cur
>> 3);
1036 mb_set_bit_atomic(lock
, cur
, bm
);
1041 static int mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1042 int first
, int count
)
1049 struct super_block
*sb
= e4b
->bd_sb
;
1051 BUG_ON(first
+ count
> (sb
->s_blocksize
<< 3));
1052 BUG_ON(!ext4_is_group_locked(sb
, e4b
->bd_group
));
1053 mb_check_buddy(e4b
);
1054 mb_free_blocks_double(inode
, e4b
, first
, count
);
1056 e4b
->bd_info
->bb_free
+= count
;
1057 if (first
< e4b
->bd_info
->bb_first_free
)
1058 e4b
->bd_info
->bb_first_free
= first
;
1060 /* let's maintain fragments counter */
1062 block
= !mb_test_bit(first
- 1, EXT4_MB_BITMAP(e4b
));
1063 if (first
+ count
< EXT4_SB(sb
)->s_mb_maxs
[0])
1064 max
= !mb_test_bit(first
+ count
, EXT4_MB_BITMAP(e4b
));
1066 e4b
->bd_info
->bb_fragments
--;
1067 else if (!block
&& !max
)
1068 e4b
->bd_info
->bb_fragments
++;
1070 /* let's maintain buddy itself */
1071 while (count
-- > 0) {
1075 if (!mb_test_bit(block
, EXT4_MB_BITMAP(e4b
))) {
1076 ext4_fsblk_t blocknr
;
1077 blocknr
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
);
1080 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
1082 ext4_error(sb
, __func__
, "double-free of inode"
1083 " %lu's block %llu(bit %u in group %lu)\n",
1084 inode
? inode
->i_ino
: 0, blocknr
, block
,
1087 mb_clear_bit(block
, EXT4_MB_BITMAP(e4b
));
1088 e4b
->bd_info
->bb_counters
[order
]++;
1090 /* start of the buddy */
1091 buddy
= mb_find_buddy(e4b
, order
, &max
);
1095 if (mb_test_bit(block
, buddy
) ||
1096 mb_test_bit(block
+ 1, buddy
))
1099 /* both the buddies are free, try to coalesce them */
1100 buddy2
= mb_find_buddy(e4b
, order
+ 1, &max
);
1106 /* for special purposes, we don't set
1107 * free bits in bitmap */
1108 mb_set_bit(block
, buddy
);
1109 mb_set_bit(block
+ 1, buddy
);
1111 e4b
->bd_info
->bb_counters
[order
]--;
1112 e4b
->bd_info
->bb_counters
[order
]--;
1116 e4b
->bd_info
->bb_counters
[order
]++;
1118 mb_clear_bit(block
, buddy2
);
1122 mb_check_buddy(e4b
);
1127 static int mb_find_extent(struct ext4_buddy
*e4b
, int order
, int block
,
1128 int needed
, struct ext4_free_extent
*ex
)
1135 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
1138 buddy
= mb_find_buddy(e4b
, order
, &max
);
1139 BUG_ON(buddy
== NULL
);
1140 BUG_ON(block
>= max
);
1141 if (mb_test_bit(block
, buddy
)) {
1148 /* FIXME dorp order completely ? */
1149 if (likely(order
== 0)) {
1150 /* find actual order */
1151 order
= mb_find_order_for_block(e4b
, block
);
1152 block
= block
>> order
;
1155 ex
->fe_len
= 1 << order
;
1156 ex
->fe_start
= block
<< order
;
1157 ex
->fe_group
= e4b
->bd_group
;
1159 /* calc difference from given start */
1160 next
= next
- ex
->fe_start
;
1162 ex
->fe_start
+= next
;
1164 while (needed
> ex
->fe_len
&&
1165 (buddy
= mb_find_buddy(e4b
, order
, &max
))) {
1167 if (block
+ 1 >= max
)
1170 next
= (block
+ 1) * (1 << order
);
1171 if (mb_test_bit(next
, EXT4_MB_BITMAP(e4b
)))
1174 ord
= mb_find_order_for_block(e4b
, next
);
1177 block
= next
>> order
;
1178 ex
->fe_len
+= 1 << order
;
1181 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1185 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1191 int start
= ex
->fe_start
;
1192 int len
= ex
->fe_len
;
1197 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1198 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1199 BUG_ON(!ext4_is_group_locked(e4b
->bd_sb
, e4b
->bd_group
));
1200 mb_check_buddy(e4b
);
1201 mb_mark_used_double(e4b
, start
, len
);
1203 e4b
->bd_info
->bb_free
-= len
;
1204 if (e4b
->bd_info
->bb_first_free
== start
)
1205 e4b
->bd_info
->bb_first_free
+= len
;
1207 /* let's maintain fragments counter */
1209 mlen
= !mb_test_bit(start
- 1, EXT4_MB_BITMAP(e4b
));
1210 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1211 max
= !mb_test_bit(start
+ len
, EXT4_MB_BITMAP(e4b
));
1213 e4b
->bd_info
->bb_fragments
++;
1214 else if (!mlen
&& !max
)
1215 e4b
->bd_info
->bb_fragments
--;
1217 /* let's maintain buddy itself */
1219 ord
= mb_find_order_for_block(e4b
, start
);
1221 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1222 /* the whole chunk may be allocated at once! */
1224 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1225 BUG_ON((start
>> ord
) >= max
);
1226 mb_set_bit(start
>> ord
, buddy
);
1227 e4b
->bd_info
->bb_counters
[ord
]--;
1234 /* store for history */
1236 ret
= len
| (ord
<< 16);
1238 /* we have to split large buddy */
1240 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1241 mb_set_bit(start
>> ord
, buddy
);
1242 e4b
->bd_info
->bb_counters
[ord
]--;
1245 cur
= (start
>> ord
) & ~1U;
1246 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1247 mb_clear_bit(cur
, buddy
);
1248 mb_clear_bit(cur
+ 1, buddy
);
1249 e4b
->bd_info
->bb_counters
[ord
]++;
1250 e4b
->bd_info
->bb_counters
[ord
]++;
1253 mb_set_bits(sb_bgl_lock(EXT4_SB(e4b
->bd_sb
), ex
->fe_group
),
1254 EXT4_MB_BITMAP(e4b
), ex
->fe_start
, len0
);
1255 mb_check_buddy(e4b
);
1261 * Must be called under group lock!
1263 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1264 struct ext4_buddy
*e4b
)
1266 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1269 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1270 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1272 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1273 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1274 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1276 /* preallocation can change ac_b_ex, thus we store actually
1277 * allocated blocks for history */
1278 ac
->ac_f_ex
= ac
->ac_b_ex
;
1280 ac
->ac_status
= AC_STATUS_FOUND
;
1281 ac
->ac_tail
= ret
& 0xffff;
1282 ac
->ac_buddy
= ret
>> 16;
1284 /* XXXXXXX: SUCH A HORRIBLE **CK */
1286 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1287 get_page(ac
->ac_bitmap_page
);
1288 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1289 get_page(ac
->ac_buddy_page
);
1291 /* store last allocated for subsequent stream allocation */
1292 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
)) {
1293 spin_lock(&sbi
->s_md_lock
);
1294 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1295 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1296 spin_unlock(&sbi
->s_md_lock
);
1301 * regular allocator, for general purposes allocation
1304 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1305 struct ext4_buddy
*e4b
,
1308 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1309 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1310 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1311 struct ext4_free_extent ex
;
1315 * We don't want to scan for a whole year
1317 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1318 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1319 ac
->ac_status
= AC_STATUS_BREAK
;
1324 * Haven't found good chunk so far, let's continue
1326 if (bex
->fe_len
< gex
->fe_len
)
1329 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1330 && bex
->fe_group
== e4b
->bd_group
) {
1331 /* recheck chunk's availability - we don't know
1332 * when it was found (within this lock-unlock
1334 max
= mb_find_extent(e4b
, 0, bex
->fe_start
, gex
->fe_len
, &ex
);
1335 if (max
>= gex
->fe_len
) {
1336 ext4_mb_use_best_found(ac
, e4b
);
1343 * The routine checks whether found extent is good enough. If it is,
1344 * then the extent gets marked used and flag is set to the context
1345 * to stop scanning. Otherwise, the extent is compared with the
1346 * previous found extent and if new one is better, then it's stored
1347 * in the context. Later, the best found extent will be used, if
1348 * mballoc can't find good enough extent.
1350 * FIXME: real allocation policy is to be designed yet!
1352 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1353 struct ext4_free_extent
*ex
,
1354 struct ext4_buddy
*e4b
)
1356 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1357 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1359 BUG_ON(ex
->fe_len
<= 0);
1360 BUG_ON(ex
->fe_len
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1361 BUG_ON(ex
->fe_start
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1362 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1367 * The special case - take what you catch first
1369 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1371 ext4_mb_use_best_found(ac
, e4b
);
1376 * Let's check whether the chuck is good enough
1378 if (ex
->fe_len
== gex
->fe_len
) {
1380 ext4_mb_use_best_found(ac
, e4b
);
1385 * If this is first found extent, just store it in the context
1387 if (bex
->fe_len
== 0) {
1393 * If new found extent is better, store it in the context
1395 if (bex
->fe_len
< gex
->fe_len
) {
1396 /* if the request isn't satisfied, any found extent
1397 * larger than previous best one is better */
1398 if (ex
->fe_len
> bex
->fe_len
)
1400 } else if (ex
->fe_len
> gex
->fe_len
) {
1401 /* if the request is satisfied, then we try to find
1402 * an extent that still satisfy the request, but is
1403 * smaller than previous one */
1404 if (ex
->fe_len
< bex
->fe_len
)
1408 ext4_mb_check_limits(ac
, e4b
, 0);
1411 static int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1412 struct ext4_buddy
*e4b
)
1414 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1415 ext4_group_t group
= ex
.fe_group
;
1419 BUG_ON(ex
.fe_len
<= 0);
1420 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1424 ext4_lock_group(ac
->ac_sb
, group
);
1425 max
= mb_find_extent(e4b
, 0, ex
.fe_start
, ex
.fe_len
, &ex
);
1429 ext4_mb_use_best_found(ac
, e4b
);
1432 ext4_unlock_group(ac
->ac_sb
, group
);
1433 ext4_mb_release_desc(e4b
);
1438 static int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1439 struct ext4_buddy
*e4b
)
1441 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1444 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1445 struct ext4_super_block
*es
= sbi
->s_es
;
1446 struct ext4_free_extent ex
;
1448 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1451 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1455 ext4_lock_group(ac
->ac_sb
, group
);
1456 max
= mb_find_extent(e4b
, 0, ac
->ac_g_ex
.fe_start
,
1457 ac
->ac_g_ex
.fe_len
, &ex
);
1459 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1462 start
= (e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
)) +
1463 ex
.fe_start
+ le32_to_cpu(es
->s_first_data_block
);
1464 /* use do_div to get remainder (would be 64-bit modulo) */
1465 if (do_div(start
, sbi
->s_stripe
) == 0) {
1468 ext4_mb_use_best_found(ac
, e4b
);
1470 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1471 BUG_ON(ex
.fe_len
<= 0);
1472 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1473 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1476 ext4_mb_use_best_found(ac
, e4b
);
1477 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1478 /* Sometimes, caller may want to merge even small
1479 * number of blocks to an existing extent */
1480 BUG_ON(ex
.fe_len
<= 0);
1481 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1482 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1485 ext4_mb_use_best_found(ac
, e4b
);
1487 ext4_unlock_group(ac
->ac_sb
, group
);
1488 ext4_mb_release_desc(e4b
);
1494 * The routine scans buddy structures (not bitmap!) from given order
1495 * to max order and tries to find big enough chunk to satisfy the req
1497 static void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1498 struct ext4_buddy
*e4b
)
1500 struct super_block
*sb
= ac
->ac_sb
;
1501 struct ext4_group_info
*grp
= e4b
->bd_info
;
1507 BUG_ON(ac
->ac_2order
<= 0);
1508 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1509 if (grp
->bb_counters
[i
] == 0)
1512 buddy
= mb_find_buddy(e4b
, i
, &max
);
1513 BUG_ON(buddy
== NULL
);
1515 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1520 ac
->ac_b_ex
.fe_len
= 1 << i
;
1521 ac
->ac_b_ex
.fe_start
= k
<< i
;
1522 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1524 ext4_mb_use_best_found(ac
, e4b
);
1526 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1528 if (EXT4_SB(sb
)->s_mb_stats
)
1529 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1536 * The routine scans the group and measures all found extents.
1537 * In order to optimize scanning, caller must pass number of
1538 * free blocks in the group, so the routine can know upper limit.
1540 static void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1541 struct ext4_buddy
*e4b
)
1543 struct super_block
*sb
= ac
->ac_sb
;
1544 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1545 struct ext4_free_extent ex
;
1549 free
= e4b
->bd_info
->bb_free
;
1552 i
= e4b
->bd_info
->bb_first_free
;
1554 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1555 i
= mb_find_next_zero_bit(bitmap
,
1556 EXT4_BLOCKS_PER_GROUP(sb
), i
);
1557 if (i
>= EXT4_BLOCKS_PER_GROUP(sb
)) {
1559 * IF we have corrupt bitmap, we won't find any
1560 * free blocks even though group info says we
1561 * we have free blocks
1563 ext4_error(sb
, __func__
, "%d free blocks as per "
1564 "group info. But bitmap says 0\n",
1569 mb_find_extent(e4b
, 0, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1570 BUG_ON(ex
.fe_len
<= 0);
1571 if (free
< ex
.fe_len
) {
1572 ext4_error(sb
, __func__
, "%d free blocks as per "
1573 "group info. But got %d blocks\n",
1576 * The number of free blocks differs. This mostly
1577 * indicate that the bitmap is corrupt. So exit
1578 * without claiming the space.
1583 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1589 ext4_mb_check_limits(ac
, e4b
, 1);
1593 * This is a special case for storages like raid5
1594 * we try to find stripe-aligned chunks for stripe-size requests
1595 * XXX should do so at least for multiples of stripe size as well
1597 static void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1598 struct ext4_buddy
*e4b
)
1600 struct super_block
*sb
= ac
->ac_sb
;
1601 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1602 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1603 struct ext4_free_extent ex
;
1604 ext4_fsblk_t first_group_block
;
1609 BUG_ON(sbi
->s_stripe
== 0);
1611 /* find first stripe-aligned block in group */
1612 first_group_block
= e4b
->bd_group
* EXT4_BLOCKS_PER_GROUP(sb
)
1613 + le32_to_cpu(sbi
->s_es
->s_first_data_block
);
1614 a
= first_group_block
+ sbi
->s_stripe
- 1;
1615 do_div(a
, sbi
->s_stripe
);
1616 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1618 while (i
< EXT4_BLOCKS_PER_GROUP(sb
)) {
1619 if (!mb_test_bit(i
, bitmap
)) {
1620 max
= mb_find_extent(e4b
, 0, i
, sbi
->s_stripe
, &ex
);
1621 if (max
>= sbi
->s_stripe
) {
1624 ext4_mb_use_best_found(ac
, e4b
);
1632 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
1633 ext4_group_t group
, int cr
)
1635 unsigned free
, fragments
;
1637 struct ext4_group_desc
*desc
;
1638 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1640 BUG_ON(cr
< 0 || cr
>= 4);
1641 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp
));
1643 free
= grp
->bb_free
;
1644 fragments
= grp
->bb_fragments
;
1652 BUG_ON(ac
->ac_2order
== 0);
1653 /* If this group is uninitialized, skip it initially */
1654 desc
= ext4_get_group_desc(ac
->ac_sb
, group
, NULL
);
1655 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
))
1658 bits
= ac
->ac_sb
->s_blocksize_bits
+ 1;
1659 for (i
= ac
->ac_2order
; i
<= bits
; i
++)
1660 if (grp
->bb_counters
[i
] > 0)
1664 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
1668 if (free
>= ac
->ac_g_ex
.fe_len
)
1680 static noinline_for_stack
int
1681 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
1688 struct ext4_sb_info
*sbi
;
1689 struct super_block
*sb
;
1690 struct ext4_buddy e4b
;
1695 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1697 /* first, try the goal */
1698 err
= ext4_mb_find_by_goal(ac
, &e4b
);
1699 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
1702 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
1706 * ac->ac2_order is set only if the fe_len is a power of 2
1707 * if ac2_order is set we also set criteria to 0 so that we
1708 * try exact allocation using buddy.
1710 i
= fls(ac
->ac_g_ex
.fe_len
);
1713 * We search using buddy data only if the order of the request
1714 * is greater than equal to the sbi_s_mb_order2_reqs
1715 * You can tune it via /proc/fs/ext4/<partition>/order2_req
1717 if (i
>= sbi
->s_mb_order2_reqs
) {
1719 * This should tell if fe_len is exactly power of 2
1721 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
1722 ac
->ac_2order
= i
- 1;
1725 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
1726 /* if stream allocation is enabled, use global goal */
1727 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
1728 isize
= i_size_read(ac
->ac_inode
) >> bsbits
;
1732 if (size
< sbi
->s_mb_stream_request
&&
1733 (ac
->ac_flags
& EXT4_MB_HINT_DATA
)) {
1734 /* TBD: may be hot point */
1735 spin_lock(&sbi
->s_md_lock
);
1736 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
1737 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
1738 spin_unlock(&sbi
->s_md_lock
);
1740 /* Let's just scan groups to find more-less suitable blocks */
1741 cr
= ac
->ac_2order
? 0 : 1;
1743 * cr == 0 try to get exact allocation,
1744 * cr == 3 try to get anything
1747 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
1748 ac
->ac_criteria
= cr
;
1750 * searching for the right group start
1751 * from the goal value specified
1753 group
= ac
->ac_g_ex
.fe_group
;
1755 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
; group
++, i
++) {
1756 struct ext4_group_info
*grp
;
1757 struct ext4_group_desc
*desc
;
1759 if (group
== EXT4_SB(sb
)->s_groups_count
)
1762 /* quick check to skip empty groups */
1763 grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1764 if (grp
->bb_free
== 0)
1768 * if the group is already init we check whether it is
1769 * a good group and if not we don't load the buddy
1771 if (EXT4_MB_GRP_NEED_INIT(grp
)) {
1773 * we need full data about the group
1774 * to make a good selection
1776 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
1779 ext4_mb_release_desc(&e4b
);
1783 * If the particular group doesn't satisfy our
1784 * criteria we continue with the next group
1786 if (!ext4_mb_good_group(ac
, group
, cr
))
1789 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
1793 ext4_lock_group(sb
, group
);
1794 if (!ext4_mb_good_group(ac
, group
, cr
)) {
1795 /* someone did allocation from this group */
1796 ext4_unlock_group(sb
, group
);
1797 ext4_mb_release_desc(&e4b
);
1801 ac
->ac_groups_scanned
++;
1802 desc
= ext4_get_group_desc(sb
, group
, NULL
);
1803 if (cr
== 0 || (desc
->bg_flags
&
1804 cpu_to_le16(EXT4_BG_BLOCK_UNINIT
) &&
1805 ac
->ac_2order
!= 0))
1806 ext4_mb_simple_scan_group(ac
, &e4b
);
1808 ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
)
1809 ext4_mb_scan_aligned(ac
, &e4b
);
1811 ext4_mb_complex_scan_group(ac
, &e4b
);
1813 ext4_unlock_group(sb
, group
);
1814 ext4_mb_release_desc(&e4b
);
1816 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
1821 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
1822 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1824 * We've been searching too long. Let's try to allocate
1825 * the best chunk we've found so far
1828 ext4_mb_try_best_found(ac
, &e4b
);
1829 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
1831 * Someone more lucky has already allocated it.
1832 * The only thing we can do is just take first
1834 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
1836 ac
->ac_b_ex
.fe_group
= 0;
1837 ac
->ac_b_ex
.fe_start
= 0;
1838 ac
->ac_b_ex
.fe_len
= 0;
1839 ac
->ac_status
= AC_STATUS_CONTINUE
;
1840 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
1842 atomic_inc(&sbi
->s_mb_lost_chunks
);
1850 #ifdef EXT4_MB_HISTORY
1851 struct ext4_mb_proc_session
{
1852 struct ext4_mb_history
*history
;
1853 struct super_block
*sb
;
1858 static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session
*s
,
1859 struct ext4_mb_history
*hs
,
1862 if (hs
== s
->history
+ s
->max
)
1864 if (!first
&& hs
== s
->history
+ s
->start
)
1866 while (hs
->orig
.fe_len
== 0) {
1868 if (hs
== s
->history
+ s
->max
)
1870 if (hs
== s
->history
+ s
->start
)
1876 static void *ext4_mb_seq_history_start(struct seq_file
*seq
, loff_t
*pos
)
1878 struct ext4_mb_proc_session
*s
= seq
->private;
1879 struct ext4_mb_history
*hs
;
1883 return SEQ_START_TOKEN
;
1884 hs
= ext4_mb_history_skip_empty(s
, s
->history
+ s
->start
, 1);
1887 while (--l
&& (hs
= ext4_mb_history_skip_empty(s
, ++hs
, 0)) != NULL
);
1891 static void *ext4_mb_seq_history_next(struct seq_file
*seq
, void *v
,
1894 struct ext4_mb_proc_session
*s
= seq
->private;
1895 struct ext4_mb_history
*hs
= v
;
1898 if (v
== SEQ_START_TOKEN
)
1899 return ext4_mb_history_skip_empty(s
, s
->history
+ s
->start
, 1);
1901 return ext4_mb_history_skip_empty(s
, ++hs
, 0);
1904 static int ext4_mb_seq_history_show(struct seq_file
*seq
, void *v
)
1906 char buf
[25], buf2
[25], buf3
[25], *fmt
;
1907 struct ext4_mb_history
*hs
= v
;
1909 if (v
== SEQ_START_TOKEN
) {
1910 seq_printf(seq
, "%-5s %-8s %-23s %-23s %-23s %-5s "
1911 "%-5s %-2s %-5s %-5s %-5s %-6s\n",
1912 "pid", "inode", "original", "goal", "result", "found",
1913 "grps", "cr", "flags", "merge", "tail", "broken");
1917 if (hs
->op
== EXT4_MB_HISTORY_ALLOC
) {
1918 fmt
= "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
1919 "%-5u %-5s %-5u %-6u\n";
1920 sprintf(buf2
, "%lu/%d/%u@%u", hs
->result
.fe_group
,
1921 hs
->result
.fe_start
, hs
->result
.fe_len
,
1922 hs
->result
.fe_logical
);
1923 sprintf(buf
, "%lu/%d/%u@%u", hs
->orig
.fe_group
,
1924 hs
->orig
.fe_start
, hs
->orig
.fe_len
,
1925 hs
->orig
.fe_logical
);
1926 sprintf(buf3
, "%lu/%d/%u@%u", hs
->goal
.fe_group
,
1927 hs
->goal
.fe_start
, hs
->goal
.fe_len
,
1928 hs
->goal
.fe_logical
);
1929 seq_printf(seq
, fmt
, hs
->pid
, hs
->ino
, buf
, buf3
, buf2
,
1930 hs
->found
, hs
->groups
, hs
->cr
, hs
->flags
,
1931 hs
->merged
? "M" : "", hs
->tail
,
1932 hs
->buddy
? 1 << hs
->buddy
: 0);
1933 } else if (hs
->op
== EXT4_MB_HISTORY_PREALLOC
) {
1934 fmt
= "%-5u %-8u %-23s %-23s %-23s\n";
1935 sprintf(buf2
, "%lu/%d/%u@%u", hs
->result
.fe_group
,
1936 hs
->result
.fe_start
, hs
->result
.fe_len
,
1937 hs
->result
.fe_logical
);
1938 sprintf(buf
, "%lu/%d/%u@%u", hs
->orig
.fe_group
,
1939 hs
->orig
.fe_start
, hs
->orig
.fe_len
,
1940 hs
->orig
.fe_logical
);
1941 seq_printf(seq
, fmt
, hs
->pid
, hs
->ino
, buf
, "", buf2
);
1942 } else if (hs
->op
== EXT4_MB_HISTORY_DISCARD
) {
1943 sprintf(buf2
, "%lu/%d/%u", hs
->result
.fe_group
,
1944 hs
->result
.fe_start
, hs
->result
.fe_len
);
1945 seq_printf(seq
, "%-5u %-8u %-23s discard\n",
1946 hs
->pid
, hs
->ino
, buf2
);
1947 } else if (hs
->op
== EXT4_MB_HISTORY_FREE
) {
1948 sprintf(buf2
, "%lu/%d/%u", hs
->result
.fe_group
,
1949 hs
->result
.fe_start
, hs
->result
.fe_len
);
1950 seq_printf(seq
, "%-5u %-8u %-23s free\n",
1951 hs
->pid
, hs
->ino
, buf2
);
1956 static void ext4_mb_seq_history_stop(struct seq_file
*seq
, void *v
)
1960 static struct seq_operations ext4_mb_seq_history_ops
= {
1961 .start
= ext4_mb_seq_history_start
,
1962 .next
= ext4_mb_seq_history_next
,
1963 .stop
= ext4_mb_seq_history_stop
,
1964 .show
= ext4_mb_seq_history_show
,
1967 static int ext4_mb_seq_history_open(struct inode
*inode
, struct file
*file
)
1969 struct super_block
*sb
= PDE(inode
)->data
;
1970 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1971 struct ext4_mb_proc_session
*s
;
1975 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1979 size
= sizeof(struct ext4_mb_history
) * sbi
->s_mb_history_max
;
1980 s
->history
= kmalloc(size
, GFP_KERNEL
);
1981 if (s
->history
== NULL
) {
1986 spin_lock(&sbi
->s_mb_history_lock
);
1987 memcpy(s
->history
, sbi
->s_mb_history
, size
);
1988 s
->max
= sbi
->s_mb_history_max
;
1989 s
->start
= sbi
->s_mb_history_cur
% s
->max
;
1990 spin_unlock(&sbi
->s_mb_history_lock
);
1992 rc
= seq_open(file
, &ext4_mb_seq_history_ops
);
1994 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2004 static int ext4_mb_seq_history_release(struct inode
*inode
, struct file
*file
)
2006 struct seq_file
*seq
= (struct seq_file
*)file
->private_data
;
2007 struct ext4_mb_proc_session
*s
= seq
->private;
2010 return seq_release(inode
, file
);
2013 static ssize_t
ext4_mb_seq_history_write(struct file
*file
,
2014 const char __user
*buffer
,
2015 size_t count
, loff_t
*ppos
)
2017 struct seq_file
*seq
= (struct seq_file
*)file
->private_data
;
2018 struct ext4_mb_proc_session
*s
= seq
->private;
2019 struct super_block
*sb
= s
->sb
;
2023 if (count
>= sizeof(str
)) {
2024 printk(KERN_ERR
"EXT4-fs: %s string too long, max %u bytes\n",
2025 "mb_history", (int)sizeof(str
));
2029 if (copy_from_user(str
, buffer
, count
))
2032 value
= simple_strtol(str
, NULL
, 0);
2035 EXT4_SB(sb
)->s_mb_history_filter
= value
;
2040 static struct file_operations ext4_mb_seq_history_fops
= {
2041 .owner
= THIS_MODULE
,
2042 .open
= ext4_mb_seq_history_open
,
2044 .write
= ext4_mb_seq_history_write
,
2045 .llseek
= seq_lseek
,
2046 .release
= ext4_mb_seq_history_release
,
2049 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2051 struct super_block
*sb
= seq
->private;
2052 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2055 if (*pos
< 0 || *pos
>= sbi
->s_groups_count
)
2059 return (void *) group
;
2062 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2064 struct super_block
*sb
= seq
->private;
2065 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2069 if (*pos
< 0 || *pos
>= sbi
->s_groups_count
)
2072 return (void *) group
;;
2075 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2077 struct super_block
*sb
= seq
->private;
2078 long group
= (long) v
;
2081 struct ext4_buddy e4b
;
2083 struct ext4_group_info info
;
2084 unsigned short counters
[16];
2089 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2090 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2091 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2092 "group", "free", "frags", "first",
2093 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2094 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2096 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2097 sizeof(struct ext4_group_info
);
2098 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2100 seq_printf(seq
, "#%-5lu: I/O error\n", group
);
2103 ext4_lock_group(sb
, group
);
2104 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2105 ext4_unlock_group(sb
, group
);
2106 ext4_mb_release_desc(&e4b
);
2108 seq_printf(seq
, "#%-5lu: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2109 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2110 for (i
= 0; i
<= 13; i
++)
2111 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2112 sg
.info
.bb_counters
[i
] : 0);
2113 seq_printf(seq
, " ]\n");
2118 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2122 static struct seq_operations ext4_mb_seq_groups_ops
= {
2123 .start
= ext4_mb_seq_groups_start
,
2124 .next
= ext4_mb_seq_groups_next
,
2125 .stop
= ext4_mb_seq_groups_stop
,
2126 .show
= ext4_mb_seq_groups_show
,
2129 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2131 struct super_block
*sb
= PDE(inode
)->data
;
2134 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2136 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2143 static struct file_operations ext4_mb_seq_groups_fops
= {
2144 .owner
= THIS_MODULE
,
2145 .open
= ext4_mb_seq_groups_open
,
2147 .llseek
= seq_lseek
,
2148 .release
= seq_release
,
2151 static void ext4_mb_history_release(struct super_block
*sb
)
2153 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2155 remove_proc_entry("mb_groups", sbi
->s_mb_proc
);
2156 remove_proc_entry("mb_history", sbi
->s_mb_proc
);
2158 kfree(sbi
->s_mb_history
);
2161 static void ext4_mb_history_init(struct super_block
*sb
)
2163 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2166 if (sbi
->s_mb_proc
!= NULL
) {
2167 proc_create_data("mb_history", S_IRUGO
, sbi
->s_mb_proc
,
2168 &ext4_mb_seq_history_fops
, sb
);
2169 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_mb_proc
,
2170 &ext4_mb_seq_groups_fops
, sb
);
2173 sbi
->s_mb_history_max
= 1000;
2174 sbi
->s_mb_history_cur
= 0;
2175 spin_lock_init(&sbi
->s_mb_history_lock
);
2176 i
= sbi
->s_mb_history_max
* sizeof(struct ext4_mb_history
);
2177 sbi
->s_mb_history
= kmalloc(i
, GFP_KERNEL
);
2178 if (likely(sbi
->s_mb_history
!= NULL
))
2179 memset(sbi
->s_mb_history
, 0, i
);
2180 /* if we can't allocate history, then we simple won't use it */
2183 static noinline_for_stack
void
2184 ext4_mb_store_history(struct ext4_allocation_context
*ac
)
2186 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
2187 struct ext4_mb_history h
;
2189 if (unlikely(sbi
->s_mb_history
== NULL
))
2192 if (!(ac
->ac_op
& sbi
->s_mb_history_filter
))
2196 h
.pid
= current
->pid
;
2197 h
.ino
= ac
->ac_inode
? ac
->ac_inode
->i_ino
: 0;
2198 h
.orig
= ac
->ac_o_ex
;
2199 h
.result
= ac
->ac_b_ex
;
2200 h
.flags
= ac
->ac_flags
;
2201 h
.found
= ac
->ac_found
;
2202 h
.groups
= ac
->ac_groups_scanned
;
2203 h
.cr
= ac
->ac_criteria
;
2204 h
.tail
= ac
->ac_tail
;
2205 h
.buddy
= ac
->ac_buddy
;
2207 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
) {
2208 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
2209 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
2211 h
.goal
= ac
->ac_g_ex
;
2212 h
.result
= ac
->ac_f_ex
;
2215 spin_lock(&sbi
->s_mb_history_lock
);
2216 memcpy(sbi
->s_mb_history
+ sbi
->s_mb_history_cur
, &h
, sizeof(h
));
2217 if (++sbi
->s_mb_history_cur
>= sbi
->s_mb_history_max
)
2218 sbi
->s_mb_history_cur
= 0;
2219 spin_unlock(&sbi
->s_mb_history_lock
);
2223 #define ext4_mb_history_release(sb)
2224 #define ext4_mb_history_init(sb)
2227 static int ext4_mb_init_backend(struct super_block
*sb
)
2230 int j
, len
, metalen
;
2231 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2232 int num_meta_group_infos
=
2233 (sbi
->s_groups_count
+ EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2234 EXT4_DESC_PER_BLOCK_BITS(sb
);
2235 struct ext4_group_info
**meta_group_info
;
2237 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2238 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2239 * So a two level scheme suffices for now. */
2240 sbi
->s_group_info
= kmalloc(sizeof(*sbi
->s_group_info
) *
2241 num_meta_group_infos
, GFP_KERNEL
);
2242 if (sbi
->s_group_info
== NULL
) {
2243 printk(KERN_ERR
"EXT4-fs: can't allocate buddy meta group\n");
2246 sbi
->s_buddy_cache
= new_inode(sb
);
2247 if (sbi
->s_buddy_cache
== NULL
) {
2248 printk(KERN_ERR
"EXT4-fs: can't get new inode\n");
2251 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2253 metalen
= sizeof(*meta_group_info
) << EXT4_DESC_PER_BLOCK_BITS(sb
);
2254 for (i
= 0; i
< num_meta_group_infos
; i
++) {
2255 if ((i
+ 1) == num_meta_group_infos
)
2256 metalen
= sizeof(*meta_group_info
) *
2257 (sbi
->s_groups_count
-
2258 (i
<< EXT4_DESC_PER_BLOCK_BITS(sb
)));
2259 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2260 if (meta_group_info
== NULL
) {
2261 printk(KERN_ERR
"EXT4-fs: can't allocate mem for a "
2265 sbi
->s_group_info
[i
] = meta_group_info
;
2269 * calculate needed size. if change bb_counters size,
2270 * don't forget about ext4_mb_generate_buddy()
2272 len
= sizeof(struct ext4_group_info
);
2273 len
+= sizeof(unsigned short) * (sb
->s_blocksize_bits
+ 2);
2274 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
2275 struct ext4_group_desc
*desc
;
2278 sbi
->s_group_info
[i
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2279 j
= i
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2281 meta_group_info
[j
] = kzalloc(len
, GFP_KERNEL
);
2282 if (meta_group_info
[j
] == NULL
) {
2283 printk(KERN_ERR
"EXT4-fs: can't allocate buddy mem\n");
2286 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2289 "EXT4-fs: can't read descriptor %lu\n", i
);
2293 memset(meta_group_info
[j
], 0, len
);
2294 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2295 &(meta_group_info
[j
]->bb_state
));
2298 * initialize bb_free to be able to skip
2299 * empty groups without initialization
2301 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2302 meta_group_info
[j
]->bb_free
=
2303 ext4_free_blocks_after_init(sb
, i
, desc
);
2305 meta_group_info
[j
]->bb_free
=
2306 le16_to_cpu(desc
->bg_free_blocks_count
);
2309 INIT_LIST_HEAD(&meta_group_info
[j
]->bb_prealloc_list
);
2313 struct buffer_head
*bh
;
2314 meta_group_info
[j
]->bb_bitmap
=
2315 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2316 BUG_ON(meta_group_info
[j
]->bb_bitmap
== NULL
);
2317 bh
= read_block_bitmap(sb
, i
);
2319 memcpy(meta_group_info
[j
]->bb_bitmap
, bh
->b_data
,
2331 kfree(ext4_get_group_info(sb
, i
));
2332 i
= num_meta_group_infos
;
2335 kfree(sbi
->s_group_info
[i
]);
2336 iput(sbi
->s_buddy_cache
);
2338 kfree(sbi
->s_group_info
);
2342 int ext4_mb_init(struct super_block
*sb
, int needs_recovery
)
2344 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2349 if (!test_opt(sb
, MBALLOC
))
2352 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(unsigned short);
2354 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2355 if (sbi
->s_mb_offsets
== NULL
) {
2356 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2359 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2360 if (sbi
->s_mb_maxs
== NULL
) {
2361 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2362 kfree(sbi
->s_mb_maxs
);
2366 /* order 0 is regular bitmap */
2367 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2368 sbi
->s_mb_offsets
[0] = 0;
2372 max
= sb
->s_blocksize
<< 2;
2374 sbi
->s_mb_offsets
[i
] = offset
;
2375 sbi
->s_mb_maxs
[i
] = max
;
2376 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2379 } while (i
<= sb
->s_blocksize_bits
+ 1);
2381 /* init file for buddy data */
2382 i
= ext4_mb_init_backend(sb
);
2384 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2385 kfree(sbi
->s_mb_offsets
);
2386 kfree(sbi
->s_mb_maxs
);
2390 spin_lock_init(&sbi
->s_md_lock
);
2391 INIT_LIST_HEAD(&sbi
->s_active_transaction
);
2392 INIT_LIST_HEAD(&sbi
->s_closed_transaction
);
2393 INIT_LIST_HEAD(&sbi
->s_committed_transaction
);
2394 spin_lock_init(&sbi
->s_bal_lock
);
2396 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2397 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2398 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2399 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2400 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2401 sbi
->s_mb_history_filter
= EXT4_MB_HISTORY_DEFAULT
;
2402 sbi
->s_mb_group_prealloc
= MB_DEFAULT_GROUP_PREALLOC
;
2404 i
= sizeof(struct ext4_locality_group
) * NR_CPUS
;
2405 sbi
->s_locality_groups
= kmalloc(i
, GFP_KERNEL
);
2406 if (sbi
->s_locality_groups
== NULL
) {
2407 clear_opt(sbi
->s_mount_opt
, MBALLOC
);
2408 kfree(sbi
->s_mb_offsets
);
2409 kfree(sbi
->s_mb_maxs
);
2412 for (i
= 0; i
< NR_CPUS
; i
++) {
2413 struct ext4_locality_group
*lg
;
2414 lg
= &sbi
->s_locality_groups
[i
];
2415 mutex_init(&lg
->lg_mutex
);
2416 INIT_LIST_HEAD(&lg
->lg_prealloc_list
);
2417 spin_lock_init(&lg
->lg_prealloc_lock
);
2420 ext4_mb_init_per_dev_proc(sb
);
2421 ext4_mb_history_init(sb
);
2423 printk("EXT4-fs: mballoc enabled\n");
2427 /* need to called with ext4 group lock (ext4_lock_group) */
2428 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2430 struct ext4_prealloc_space
*pa
;
2431 struct list_head
*cur
, *tmp
;
2434 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2435 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2436 list_del(&pa
->pa_group_list
);
2441 mb_debug("mballoc: %u PAs left\n", count
);
2445 int ext4_mb_release(struct super_block
*sb
)
2448 int num_meta_group_infos
;
2449 struct ext4_group_info
*grinfo
;
2450 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2452 if (!test_opt(sb
, MBALLOC
))
2455 /* release freed, non-committed blocks */
2456 spin_lock(&sbi
->s_md_lock
);
2457 list_splice_init(&sbi
->s_closed_transaction
,
2458 &sbi
->s_committed_transaction
);
2459 list_splice_init(&sbi
->s_active_transaction
,
2460 &sbi
->s_committed_transaction
);
2461 spin_unlock(&sbi
->s_md_lock
);
2462 ext4_mb_free_committed_blocks(sb
);
2464 if (sbi
->s_group_info
) {
2465 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
2466 grinfo
= ext4_get_group_info(sb
, i
);
2468 kfree(grinfo
->bb_bitmap
);
2470 ext4_lock_group(sb
, i
);
2471 ext4_mb_cleanup_pa(grinfo
);
2472 ext4_unlock_group(sb
, i
);
2475 num_meta_group_infos
= (sbi
->s_groups_count
+
2476 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2477 EXT4_DESC_PER_BLOCK_BITS(sb
);
2478 for (i
= 0; i
< num_meta_group_infos
; i
++)
2479 kfree(sbi
->s_group_info
[i
]);
2480 kfree(sbi
->s_group_info
);
2482 kfree(sbi
->s_mb_offsets
);
2483 kfree(sbi
->s_mb_maxs
);
2484 if (sbi
->s_buddy_cache
)
2485 iput(sbi
->s_buddy_cache
);
2486 if (sbi
->s_mb_stats
) {
2488 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2489 atomic_read(&sbi
->s_bal_allocated
),
2490 atomic_read(&sbi
->s_bal_reqs
),
2491 atomic_read(&sbi
->s_bal_success
));
2493 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2494 "%u 2^N hits, %u breaks, %u lost\n",
2495 atomic_read(&sbi
->s_bal_ex_scanned
),
2496 atomic_read(&sbi
->s_bal_goals
),
2497 atomic_read(&sbi
->s_bal_2orders
),
2498 atomic_read(&sbi
->s_bal_breaks
),
2499 atomic_read(&sbi
->s_mb_lost_chunks
));
2501 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2502 sbi
->s_mb_buddies_generated
++,
2503 sbi
->s_mb_generation_time
);
2505 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2506 atomic_read(&sbi
->s_mb_preallocated
),
2507 atomic_read(&sbi
->s_mb_discarded
));
2510 kfree(sbi
->s_locality_groups
);
2512 ext4_mb_history_release(sb
);
2513 ext4_mb_destroy_per_dev_proc(sb
);
2518 static noinline_for_stack
void
2519 ext4_mb_free_committed_blocks(struct super_block
*sb
)
2521 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2526 struct ext4_free_metadata
*md
;
2527 struct ext4_buddy e4b
;
2529 if (list_empty(&sbi
->s_committed_transaction
))
2532 /* there is committed blocks to be freed yet */
2534 /* get next array of blocks */
2536 spin_lock(&sbi
->s_md_lock
);
2537 if (!list_empty(&sbi
->s_committed_transaction
)) {
2538 md
= list_entry(sbi
->s_committed_transaction
.next
,
2539 struct ext4_free_metadata
, list
);
2540 list_del(&md
->list
);
2542 spin_unlock(&sbi
->s_md_lock
);
2547 mb_debug("gonna free %u blocks in group %lu (0x%p):",
2548 md
->num
, md
->group
, md
);
2550 err
= ext4_mb_load_buddy(sb
, md
->group
, &e4b
);
2551 /* we expect to find existing buddy because it's pinned */
2554 /* there are blocks to put in buddy to make them really free */
2557 ext4_lock_group(sb
, md
->group
);
2558 for (i
= 0; i
< md
->num
; i
++) {
2559 mb_debug(" %u", md
->blocks
[i
]);
2560 err
= mb_free_blocks(NULL
, &e4b
, md
->blocks
[i
], 1);
2564 ext4_unlock_group(sb
, md
->group
);
2566 /* balance refcounts from ext4_mb_free_metadata() */
2567 page_cache_release(e4b
.bd_buddy_page
);
2568 page_cache_release(e4b
.bd_bitmap_page
);
2571 ext4_mb_release_desc(&e4b
);
2575 mb_debug("freed %u blocks in %u structures\n", count
, count2
);
2578 #define EXT4_MB_STATS_NAME "stats"
2579 #define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
2580 #define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
2581 #define EXT4_MB_ORDER2_REQ "order2_req"
2582 #define EXT4_MB_STREAM_REQ "stream_req"
2583 #define EXT4_MB_GROUP_PREALLOC "group_prealloc"
2587 #define MB_PROC_FOPS(name) \
2588 static int ext4_mb_##name##_proc_show(struct seq_file *m, void *v) \
2590 struct ext4_sb_info *sbi = m->private; \
2592 seq_printf(m, "%ld\n", sbi->s_mb_##name); \
2596 static int ext4_mb_##name##_proc_open(struct inode *inode, struct file *file)\
2598 return single_open(file, ext4_mb_##name##_proc_show, PDE(inode)->data);\
2601 static ssize_t ext4_mb_##name##_proc_write(struct file *file, \
2602 const char __user *buf, size_t cnt, loff_t *ppos) \
2604 struct ext4_sb_info *sbi = PDE(file->f_path.dentry->d_inode)->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 static const struct file_operations ext4_mb_##name##_proc_fops = { \
2619 .owner = THIS_MODULE, \
2620 .open = ext4_mb_##name##_proc_open, \
2622 .llseek = seq_lseek, \
2623 .release = single_release, \
2624 .write = ext4_mb_##name##_proc_write, \
2627 MB_PROC_FOPS(stats
);
2628 MB_PROC_FOPS(max_to_scan
);
2629 MB_PROC_FOPS(min_to_scan
);
2630 MB_PROC_FOPS(order2_reqs
);
2631 MB_PROC_FOPS(stream_request
);
2632 MB_PROC_FOPS(group_prealloc
);
2634 #define MB_PROC_HANDLER(name, var) \
2636 proc = proc_create_data(name, mode, sbi->s_mb_proc, \
2637 &ext4_mb_##var##_proc_fops, sbi); \
2638 if (proc == NULL) { \
2639 printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
2644 static int ext4_mb_init_per_dev_proc(struct super_block
*sb
)
2646 mode_t mode
= S_IFREG
| S_IRUGO
| S_IWUSR
;
2647 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2648 struct proc_dir_entry
*proc
;
2651 bdevname(sb
->s_bdev
, devname
);
2652 sbi
->s_mb_proc
= proc_mkdir(devname
, proc_root_ext4
);
2654 MB_PROC_HANDLER(EXT4_MB_STATS_NAME
, stats
);
2655 MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME
, max_to_scan
);
2656 MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME
, min_to_scan
);
2657 MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ
, order2_reqs
);
2658 MB_PROC_HANDLER(EXT4_MB_STREAM_REQ
, stream_request
);
2659 MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC
, group_prealloc
);
2664 printk(KERN_ERR
"EXT4-fs: Unable to create %s\n", devname
);
2665 remove_proc_entry(EXT4_MB_GROUP_PREALLOC
, sbi
->s_mb_proc
);
2666 remove_proc_entry(EXT4_MB_STREAM_REQ
, sbi
->s_mb_proc
);
2667 remove_proc_entry(EXT4_MB_ORDER2_REQ
, sbi
->s_mb_proc
);
2668 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2669 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2670 remove_proc_entry(EXT4_MB_STATS_NAME
, sbi
->s_mb_proc
);
2671 remove_proc_entry(devname
, proc_root_ext4
);
2672 sbi
->s_mb_proc
= NULL
;
2677 static int ext4_mb_destroy_per_dev_proc(struct super_block
*sb
)
2679 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2682 if (sbi
->s_mb_proc
== NULL
)
2685 bdevname(sb
->s_bdev
, devname
);
2686 remove_proc_entry(EXT4_MB_GROUP_PREALLOC
, sbi
->s_mb_proc
);
2687 remove_proc_entry(EXT4_MB_STREAM_REQ
, sbi
->s_mb_proc
);
2688 remove_proc_entry(EXT4_MB_ORDER2_REQ
, sbi
->s_mb_proc
);
2689 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2690 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME
, sbi
->s_mb_proc
);
2691 remove_proc_entry(EXT4_MB_STATS_NAME
, sbi
->s_mb_proc
);
2692 remove_proc_entry(devname
, proc_root_ext4
);
2697 int __init
init_ext4_mballoc(void)
2699 ext4_pspace_cachep
=
2700 kmem_cache_create("ext4_prealloc_space",
2701 sizeof(struct ext4_prealloc_space
),
2702 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2703 if (ext4_pspace_cachep
== NULL
)
2707 kmem_cache_create("ext4_alloc_context",
2708 sizeof(struct ext4_allocation_context
),
2709 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2710 if (ext4_ac_cachep
== NULL
) {
2711 kmem_cache_destroy(ext4_pspace_cachep
);
2714 #ifdef CONFIG_PROC_FS
2715 proc_root_ext4
= proc_mkdir("fs/ext4", NULL
);
2716 if (proc_root_ext4
== NULL
)
2717 printk(KERN_ERR
"EXT4-fs: Unable to create fs/ext4\n");
2722 void exit_ext4_mballoc(void)
2724 /* XXX: synchronize_rcu(); */
2725 kmem_cache_destroy(ext4_pspace_cachep
);
2726 kmem_cache_destroy(ext4_ac_cachep
);
2727 #ifdef CONFIG_PROC_FS
2728 remove_proc_entry("fs/ext4", NULL
);
2734 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
2735 * Returns 0 if success or error code
2737 static noinline_for_stack
int
2738 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2741 struct buffer_head
*bitmap_bh
= NULL
;
2742 struct ext4_super_block
*es
;
2743 struct ext4_group_desc
*gdp
;
2744 struct buffer_head
*gdp_bh
;
2745 struct ext4_sb_info
*sbi
;
2746 struct super_block
*sb
;
2750 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2751 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2759 bitmap_bh
= read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2763 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2768 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2772 ext4_debug("using block group %lu(%d)\n", ac
->ac_b_ex
.fe_group
,
2773 gdp
->bg_free_blocks_count
);
2775 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2779 block
= ac
->ac_b_ex
.fe_group
* EXT4_BLOCKS_PER_GROUP(sb
)
2780 + ac
->ac_b_ex
.fe_start
2781 + le32_to_cpu(es
->s_first_data_block
);
2783 len
= ac
->ac_b_ex
.fe_len
;
2784 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, len
) ||
2785 in_range(ext4_inode_bitmap(sb
, gdp
), block
, len
) ||
2786 in_range(block
, ext4_inode_table(sb
, gdp
),
2787 EXT4_SB(sb
)->s_itb_per_group
) ||
2788 in_range(block
+ len
- 1, ext4_inode_table(sb
, gdp
),
2789 EXT4_SB(sb
)->s_itb_per_group
)) {
2790 ext4_error(sb
, __func__
,
2791 "Allocating block in system zone - block = %llu",
2793 /* File system mounted not to panic on error
2794 * Fix the bitmap and repeat the block allocation
2795 * We leak some of the blocks here.
2797 mb_set_bits(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
),
2798 bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2799 ac
->ac_b_ex
.fe_len
);
2800 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
2805 #ifdef AGGRESSIVE_CHECK
2808 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2809 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2810 bitmap_bh
->b_data
));
2814 mb_set_bits(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
), bitmap_bh
->b_data
,
2815 ac
->ac_b_ex
.fe_start
, ac
->ac_b_ex
.fe_len
);
2817 spin_lock(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
));
2818 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2819 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2820 gdp
->bg_free_blocks_count
=
2821 cpu_to_le16(ext4_free_blocks_after_init(sb
,
2822 ac
->ac_b_ex
.fe_group
,
2825 le16_add_cpu(&gdp
->bg_free_blocks_count
, -ac
->ac_b_ex
.fe_len
);
2826 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, ac
->ac_b_ex
.fe_group
, gdp
);
2827 spin_unlock(sb_bgl_lock(sbi
, ac
->ac_b_ex
.fe_group
));
2828 percpu_counter_sub(&sbi
->s_freeblocks_counter
, ac
->ac_b_ex
.fe_len
);
2830 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
2833 err
= ext4_journal_dirty_metadata(handle
, gdp_bh
);
2842 * here we normalize request for locality group
2843 * Group request are normalized to s_strip size if we set the same via mount
2844 * option. If not we set it to s_mb_group_prealloc which can be configured via
2845 * /proc/fs/ext4/<partition>/group_prealloc
2847 * XXX: should we try to preallocate more than the group has now?
2849 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2851 struct super_block
*sb
= ac
->ac_sb
;
2852 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2855 if (EXT4_SB(sb
)->s_stripe
)
2856 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_stripe
;
2858 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2859 mb_debug("#%u: goal %u blocks for locality group\n",
2860 current
->pid
, ac
->ac_g_ex
.fe_len
);
2864 * Normalization means making request better in terms of
2865 * size and alignment
2867 static noinline_for_stack
void
2868 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
2869 struct ext4_allocation_request
*ar
)
2873 loff_t size
, orig_size
, start_off
;
2874 ext4_lblk_t start
, orig_start
;
2875 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
2876 struct ext4_prealloc_space
*pa
;
2878 /* do normalize only data requests, metadata requests
2879 do not need preallocation */
2880 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
2883 /* sometime caller may want exact blocks */
2884 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2887 /* caller may indicate that preallocation isn't
2888 * required (it's a tail, for example) */
2889 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
2892 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
2893 ext4_mb_normalize_group_request(ac
);
2897 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
2899 /* first, let's learn actual file size
2900 * given current request is allocated */
2901 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
2902 size
= size
<< bsbits
;
2903 if (size
< i_size_read(ac
->ac_inode
))
2904 size
= i_size_read(ac
->ac_inode
);
2906 /* max size of free chunks */
2909 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
2910 (req <= (size) || max <= (chunk_size))
2912 /* first, try to predict filesize */
2913 /* XXX: should this table be tunable? */
2915 if (size
<= 16 * 1024) {
2917 } else if (size
<= 32 * 1024) {
2919 } else if (size
<= 64 * 1024) {
2921 } else if (size
<= 128 * 1024) {
2923 } else if (size
<= 256 * 1024) {
2925 } else if (size
<= 512 * 1024) {
2927 } else if (size
<= 1024 * 1024) {
2929 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
2930 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2931 (21 - bsbits
)) << 21;
2932 size
= 2 * 1024 * 1024;
2933 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
2934 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2935 (22 - bsbits
)) << 22;
2936 size
= 4 * 1024 * 1024;
2937 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
2938 (8<<20)>>bsbits
, max
, 8 * 1024)) {
2939 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2940 (23 - bsbits
)) << 23;
2941 size
= 8 * 1024 * 1024;
2943 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
2944 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
2946 orig_size
= size
= size
>> bsbits
;
2947 orig_start
= start
= start_off
>> bsbits
;
2949 /* don't cover already allocated blocks in selected range */
2950 if (ar
->pleft
&& start
<= ar
->lleft
) {
2951 size
-= ar
->lleft
+ 1 - start
;
2952 start
= ar
->lleft
+ 1;
2954 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
2955 size
-= start
+ size
- ar
->lright
;
2959 /* check we don't cross already preallocated blocks */
2961 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
2962 unsigned long pa_end
;
2966 spin_lock(&pa
->pa_lock
);
2967 if (pa
->pa_deleted
) {
2968 spin_unlock(&pa
->pa_lock
);
2972 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
2974 /* PA must not overlap original request */
2975 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
2976 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
2978 /* skip PA normalized request doesn't overlap with */
2979 if (pa
->pa_lstart
>= end
) {
2980 spin_unlock(&pa
->pa_lock
);
2983 if (pa_end
<= start
) {
2984 spin_unlock(&pa
->pa_lock
);
2987 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
2989 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
2990 BUG_ON(pa_end
< start
);
2994 if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
2995 BUG_ON(pa
->pa_lstart
> end
);
2996 end
= pa
->pa_lstart
;
2998 spin_unlock(&pa
->pa_lock
);
3003 /* XXX: extra loop to check we really don't overlap preallocations */
3005 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3006 unsigned long pa_end
;
3007 spin_lock(&pa
->pa_lock
);
3008 if (pa
->pa_deleted
== 0) {
3009 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
3010 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3012 spin_unlock(&pa
->pa_lock
);
3016 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3017 start
> ac
->ac_o_ex
.fe_logical
) {
3018 printk(KERN_ERR
"start %lu, size %lu, fe_logical %lu\n",
3019 (unsigned long) start
, (unsigned long) size
,
3020 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3022 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3023 start
> ac
->ac_o_ex
.fe_logical
);
3024 BUG_ON(size
<= 0 || size
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3026 /* now prepare goal request */
3028 /* XXX: is it better to align blocks WRT to logical
3029 * placement or satisfy big request as is */
3030 ac
->ac_g_ex
.fe_logical
= start
;
3031 ac
->ac_g_ex
.fe_len
= size
;
3033 /* define goal start in order to merge */
3034 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3035 /* merge to the right */
3036 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3037 &ac
->ac_f_ex
.fe_group
,
3038 &ac
->ac_f_ex
.fe_start
);
3039 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3041 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3042 /* merge to the left */
3043 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3044 &ac
->ac_f_ex
.fe_group
,
3045 &ac
->ac_f_ex
.fe_start
);
3046 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3049 mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3050 (unsigned) orig_size
, (unsigned) start
);
3053 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3055 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3057 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3058 atomic_inc(&sbi
->s_bal_reqs
);
3059 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3060 if (ac
->ac_o_ex
.fe_len
>= ac
->ac_g_ex
.fe_len
)
3061 atomic_inc(&sbi
->s_bal_success
);
3062 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3063 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3064 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3065 atomic_inc(&sbi
->s_bal_goals
);
3066 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3067 atomic_inc(&sbi
->s_bal_breaks
);
3070 ext4_mb_store_history(ac
);
3074 * use blocks preallocated to inode
3076 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3077 struct ext4_prealloc_space
*pa
)
3083 /* found preallocated blocks, use them */
3084 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3085 end
= min(pa
->pa_pstart
+ pa
->pa_len
, start
+ ac
->ac_o_ex
.fe_len
);
3087 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3088 &ac
->ac_b_ex
.fe_start
);
3089 ac
->ac_b_ex
.fe_len
= len
;
3090 ac
->ac_status
= AC_STATUS_FOUND
;
3093 BUG_ON(start
< pa
->pa_pstart
);
3094 BUG_ON(start
+ len
> pa
->pa_pstart
+ pa
->pa_len
);
3095 BUG_ON(pa
->pa_free
< len
);
3098 mb_debug("use %llu/%u from inode pa %p\n", start
, len
, pa
);
3102 * use blocks preallocated to locality group
3104 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3105 struct ext4_prealloc_space
*pa
)
3107 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3108 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3109 &ac
->ac_b_ex
.fe_group
,
3110 &ac
->ac_b_ex
.fe_start
);
3111 ac
->ac_b_ex
.fe_len
= len
;
3112 ac
->ac_status
= AC_STATUS_FOUND
;
3115 /* we don't correct pa_pstart or pa_plen here to avoid
3116 * possible race when the group is being loaded concurrently
3117 * instead we correct pa later, after blocks are marked
3118 * in on-disk bitmap -- see ext4_mb_release_context()
3119 * Other CPUs are prevented from allocating from this pa by lg_mutex
3121 mb_debug("use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3125 * search goal blocks in preallocated space
3127 static noinline_for_stack
int
3128 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3130 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3131 struct ext4_locality_group
*lg
;
3132 struct ext4_prealloc_space
*pa
;
3134 /* only data can be preallocated */
3135 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3138 /* first, try per-file preallocation */
3140 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3142 /* all fields in this condition don't change,
3143 * so we can skip locking for them */
3144 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3145 ac
->ac_o_ex
.fe_logical
>= pa
->pa_lstart
+ pa
->pa_len
)
3148 /* found preallocated blocks, use them */
3149 spin_lock(&pa
->pa_lock
);
3150 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3151 atomic_inc(&pa
->pa_count
);
3152 ext4_mb_use_inode_pa(ac
, pa
);
3153 spin_unlock(&pa
->pa_lock
);
3154 ac
->ac_criteria
= 10;
3158 spin_unlock(&pa
->pa_lock
);
3162 /* can we use group allocation? */
3163 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3166 /* inode may have no locality group for some reason */
3172 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
, pa_inode_list
) {
3173 spin_lock(&pa
->pa_lock
);
3174 if (pa
->pa_deleted
== 0 && pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3175 atomic_inc(&pa
->pa_count
);
3176 ext4_mb_use_group_pa(ac
, pa
);
3177 spin_unlock(&pa
->pa_lock
);
3178 ac
->ac_criteria
= 20;
3182 spin_unlock(&pa
->pa_lock
);
3190 * the function goes through all preallocation in this group and marks them
3191 * used in in-core bitmap. buddy must be generated from this bitmap
3192 * Need to be called with ext4 group lock (ext4_lock_group)
3194 static void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3197 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3198 struct ext4_prealloc_space
*pa
;
3199 struct list_head
*cur
;
3200 ext4_group_t groupnr
;
3201 ext4_grpblk_t start
;
3202 int preallocated
= 0;
3206 /* all form of preallocation discards first load group,
3207 * so the only competing code is preallocation use.
3208 * we don't need any locking here
3209 * notice we do NOT ignore preallocations with pa_deleted
3210 * otherwise we could leave used blocks available for
3211 * allocation in buddy when concurrent ext4_mb_put_pa()
3212 * is dropping preallocation
3214 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3215 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3216 spin_lock(&pa
->pa_lock
);
3217 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3220 spin_unlock(&pa
->pa_lock
);
3221 if (unlikely(len
== 0))
3223 BUG_ON(groupnr
!= group
);
3224 mb_set_bits(sb_bgl_lock(EXT4_SB(sb
), group
),
3225 bitmap
, start
, len
);
3226 preallocated
+= len
;
3229 mb_debug("prellocated %u for group %lu\n", preallocated
, group
);
3232 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3234 struct ext4_prealloc_space
*pa
;
3235 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3236 kmem_cache_free(ext4_pspace_cachep
, pa
);
3240 * drops a reference to preallocated space descriptor
3241 * if this was the last reference and the space is consumed
3243 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3244 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3248 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0)
3251 /* in this short window concurrent discard can set pa_deleted */
3252 spin_lock(&pa
->pa_lock
);
3253 if (pa
->pa_deleted
== 1) {
3254 spin_unlock(&pa
->pa_lock
);
3259 spin_unlock(&pa
->pa_lock
);
3261 /* -1 is to protect from crossing allocation group */
3262 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
- 1, &grp
, NULL
);
3267 * P1 (buddy init) P2 (regular allocation)
3268 * find block B in PA
3269 * copy on-disk bitmap to buddy
3270 * mark B in on-disk bitmap
3271 * drop PA from group
3272 * mark all PAs in buddy
3274 * thus, P1 initializes buddy with B available. to prevent this
3275 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3278 ext4_lock_group(sb
, grp
);
3279 list_del(&pa
->pa_group_list
);
3280 ext4_unlock_group(sb
, grp
);
3282 spin_lock(pa
->pa_obj_lock
);
3283 list_del_rcu(&pa
->pa_inode_list
);
3284 spin_unlock(pa
->pa_obj_lock
);
3286 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3290 * creates new preallocated space for given inode
3292 static noinline_for_stack
int
3293 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3295 struct super_block
*sb
= ac
->ac_sb
;
3296 struct ext4_prealloc_space
*pa
;
3297 struct ext4_group_info
*grp
;
3298 struct ext4_inode_info
*ei
;
3300 /* preallocate only when found space is larger then requested */
3301 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3302 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3303 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3305 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3309 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3315 /* we can't allocate as much as normalizer wants.
3316 * so, found space must get proper lstart
3317 * to cover original request */
3318 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3319 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3321 /* we're limited by original request in that
3322 * logical block must be covered any way
3323 * winl is window we can move our chunk within */
3324 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3326 /* also, we should cover whole original request */
3327 wins
= ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
;
3329 /* the smallest one defines real window */
3330 win
= min(winl
, wins
);
3332 offs
= ac
->ac_o_ex
.fe_logical
% ac
->ac_b_ex
.fe_len
;
3333 if (offs
&& offs
< win
)
3336 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
- win
;
3337 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3338 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3341 /* preallocation can change ac_b_ex, thus we store actually
3342 * allocated blocks for history */
3343 ac
->ac_f_ex
= ac
->ac_b_ex
;
3345 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3346 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3347 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3348 pa
->pa_free
= pa
->pa_len
;
3349 atomic_set(&pa
->pa_count
, 1);
3350 spin_lock_init(&pa
->pa_lock
);
3354 mb_debug("new inode pa %p: %llu/%u for %u\n", pa
,
3355 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3357 ext4_mb_use_inode_pa(ac
, pa
);
3358 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3360 ei
= EXT4_I(ac
->ac_inode
);
3361 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3363 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3364 pa
->pa_inode
= ac
->ac_inode
;
3366 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3367 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3368 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3370 spin_lock(pa
->pa_obj_lock
);
3371 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3372 spin_unlock(pa
->pa_obj_lock
);
3378 * creates new preallocated space for locality group inodes belongs to
3380 static noinline_for_stack
int
3381 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3383 struct super_block
*sb
= ac
->ac_sb
;
3384 struct ext4_locality_group
*lg
;
3385 struct ext4_prealloc_space
*pa
;
3386 struct ext4_group_info
*grp
;
3388 /* preallocate only when found space is larger then requested */
3389 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3390 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3391 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3393 BUG_ON(ext4_pspace_cachep
== NULL
);
3394 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3398 /* preallocation can change ac_b_ex, thus we store actually
3399 * allocated blocks for history */
3400 ac
->ac_f_ex
= ac
->ac_b_ex
;
3402 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3403 pa
->pa_lstart
= pa
->pa_pstart
;
3404 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3405 pa
->pa_free
= pa
->pa_len
;
3406 atomic_set(&pa
->pa_count
, 1);
3407 spin_lock_init(&pa
->pa_lock
);
3411 mb_debug("new group pa %p: %llu/%u for %u\n", pa
,
3412 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3414 ext4_mb_use_group_pa(ac
, pa
);
3415 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3417 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3421 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3422 pa
->pa_inode
= NULL
;
3424 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3425 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3426 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3428 spin_lock(pa
->pa_obj_lock
);
3429 list_add_tail_rcu(&pa
->pa_inode_list
, &lg
->lg_prealloc_list
);
3430 spin_unlock(pa
->pa_obj_lock
);
3435 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3439 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3440 err
= ext4_mb_new_group_pa(ac
);
3442 err
= ext4_mb_new_inode_pa(ac
);
3447 * finds all unused blocks in on-disk bitmap, frees them in
3448 * in-core bitmap and buddy.
3449 * @pa must be unlinked from inode and group lists, so that
3450 * nobody else can find/use it.
3451 * the caller MUST hold group/inode locks.
3452 * TODO: optimize the case when there are no in-core structures yet
3454 static noinline_for_stack
int
3455 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3456 struct ext4_prealloc_space
*pa
,
3457 struct ext4_allocation_context
*ac
)
3459 struct super_block
*sb
= e4b
->bd_sb
;
3460 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3469 BUG_ON(pa
->pa_deleted
== 0);
3470 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3471 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3472 end
= bit
+ pa
->pa_len
;
3476 ac
->ac_inode
= pa
->pa_inode
;
3477 ac
->ac_op
= EXT4_MB_HISTORY_DISCARD
;
3481 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3484 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3485 start
= group
* EXT4_BLOCKS_PER_GROUP(sb
) + bit
+
3486 le32_to_cpu(sbi
->s_es
->s_first_data_block
);
3487 mb_debug(" free preallocated %u/%u in group %u\n",
3488 (unsigned) start
, (unsigned) next
- bit
,
3493 ac
->ac_b_ex
.fe_group
= group
;
3494 ac
->ac_b_ex
.fe_start
= bit
;
3495 ac
->ac_b_ex
.fe_len
= next
- bit
;
3496 ac
->ac_b_ex
.fe_logical
= 0;
3497 ext4_mb_store_history(ac
);
3500 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3503 if (free
!= pa
->pa_free
) {
3504 printk(KERN_CRIT
"pa %p: logic %lu, phys. %lu, len %lu\n",
3505 pa
, (unsigned long) pa
->pa_lstart
,
3506 (unsigned long) pa
->pa_pstart
,
3507 (unsigned long) pa
->pa_len
);
3508 ext4_error(sb
, __func__
, "free %u, pa_free %u\n",
3511 * pa is already deleted so we use the value obtained
3512 * from the bitmap and continue.
3515 atomic_add(free
, &sbi
->s_mb_discarded
);
3520 static noinline_for_stack
int
3521 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3522 struct ext4_prealloc_space
*pa
,
3523 struct ext4_allocation_context
*ac
)
3525 struct super_block
*sb
= e4b
->bd_sb
;
3530 ac
->ac_op
= EXT4_MB_HISTORY_DISCARD
;
3532 BUG_ON(pa
->pa_deleted
== 0);
3533 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3534 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3535 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3536 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3540 ac
->ac_inode
= NULL
;
3541 ac
->ac_b_ex
.fe_group
= group
;
3542 ac
->ac_b_ex
.fe_start
= bit
;
3543 ac
->ac_b_ex
.fe_len
= pa
->pa_len
;
3544 ac
->ac_b_ex
.fe_logical
= 0;
3545 ext4_mb_store_history(ac
);
3552 * releases all preallocations in given group
3554 * first, we need to decide discard policy:
3555 * - when do we discard
3557 * - how many do we discard
3558 * 1) how many requested
3560 static noinline_for_stack
int
3561 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3562 ext4_group_t group
, int needed
)
3564 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3565 struct buffer_head
*bitmap_bh
= NULL
;
3566 struct ext4_prealloc_space
*pa
, *tmp
;
3567 struct ext4_allocation_context
*ac
;
3568 struct list_head list
;
3569 struct ext4_buddy e4b
;
3574 mb_debug("discard preallocation for group %lu\n", group
);
3576 if (list_empty(&grp
->bb_prealloc_list
))
3579 bitmap_bh
= read_block_bitmap(sb
, group
);
3580 if (bitmap_bh
== NULL
) {
3581 /* error handling here */
3582 ext4_mb_release_desc(&e4b
);
3583 BUG_ON(bitmap_bh
== NULL
);
3586 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3587 BUG_ON(err
!= 0); /* error handling here */
3590 needed
= EXT4_BLOCKS_PER_GROUP(sb
) + 1;
3592 grp
= ext4_get_group_info(sb
, group
);
3593 INIT_LIST_HEAD(&list
);
3595 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3597 ext4_lock_group(sb
, group
);
3598 list_for_each_entry_safe(pa
, tmp
,
3599 &grp
->bb_prealloc_list
, pa_group_list
) {
3600 spin_lock(&pa
->pa_lock
);
3601 if (atomic_read(&pa
->pa_count
)) {
3602 spin_unlock(&pa
->pa_lock
);
3606 if (pa
->pa_deleted
) {
3607 spin_unlock(&pa
->pa_lock
);
3611 /* seems this one can be freed ... */
3614 /* we can trust pa_free ... */
3615 free
+= pa
->pa_free
;
3617 spin_unlock(&pa
->pa_lock
);
3619 list_del(&pa
->pa_group_list
);
3620 list_add(&pa
->u
.pa_tmp_list
, &list
);
3623 /* if we still need more blocks and some PAs were used, try again */
3624 if (free
< needed
&& busy
) {
3626 ext4_unlock_group(sb
, group
);
3628 * Yield the CPU here so that we don't get soft lockup
3629 * in non preempt case.
3635 /* found anything to free? */
3636 if (list_empty(&list
)) {
3641 /* now free all selected PAs */
3642 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3644 /* remove from object (inode or locality group) */
3645 spin_lock(pa
->pa_obj_lock
);
3646 list_del_rcu(&pa
->pa_inode_list
);
3647 spin_unlock(pa
->pa_obj_lock
);
3650 ext4_mb_release_group_pa(&e4b
, pa
, ac
);
3652 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3654 list_del(&pa
->u
.pa_tmp_list
);
3655 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3659 ext4_unlock_group(sb
, group
);
3661 kmem_cache_free(ext4_ac_cachep
, ac
);
3662 ext4_mb_release_desc(&e4b
);
3668 * releases all non-used preallocated blocks for given inode
3670 * It's important to discard preallocations under i_data_sem
3671 * We don't want another block to be served from the prealloc
3672 * space when we are discarding the inode prealloc space.
3674 * FIXME!! Make sure it is valid at all the call sites
3676 void ext4_mb_discard_inode_preallocations(struct inode
*inode
)
3678 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3679 struct super_block
*sb
= inode
->i_sb
;
3680 struct buffer_head
*bitmap_bh
= NULL
;
3681 struct ext4_prealloc_space
*pa
, *tmp
;
3682 struct ext4_allocation_context
*ac
;
3683 ext4_group_t group
= 0;
3684 struct list_head list
;
3685 struct ext4_buddy e4b
;
3688 if (!test_opt(sb
, MBALLOC
) || !S_ISREG(inode
->i_mode
)) {
3689 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3693 mb_debug("discard preallocation for inode %lu\n", inode
->i_ino
);
3695 INIT_LIST_HEAD(&list
);
3697 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3699 /* first, collect all pa's in the inode */
3700 spin_lock(&ei
->i_prealloc_lock
);
3701 while (!list_empty(&ei
->i_prealloc_list
)) {
3702 pa
= list_entry(ei
->i_prealloc_list
.next
,
3703 struct ext4_prealloc_space
, pa_inode_list
);
3704 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3705 spin_lock(&pa
->pa_lock
);
3706 if (atomic_read(&pa
->pa_count
)) {
3707 /* this shouldn't happen often - nobody should
3708 * use preallocation while we're discarding it */
3709 spin_unlock(&pa
->pa_lock
);
3710 spin_unlock(&ei
->i_prealloc_lock
);
3711 printk(KERN_ERR
"uh-oh! used pa while discarding\n");
3713 schedule_timeout_uninterruptible(HZ
);
3717 if (pa
->pa_deleted
== 0) {
3719 spin_unlock(&pa
->pa_lock
);
3720 list_del_rcu(&pa
->pa_inode_list
);
3721 list_add(&pa
->u
.pa_tmp_list
, &list
);
3725 /* someone is deleting pa right now */
3726 spin_unlock(&pa
->pa_lock
);
3727 spin_unlock(&ei
->i_prealloc_lock
);
3729 /* we have to wait here because pa_deleted
3730 * doesn't mean pa is already unlinked from
3731 * the list. as we might be called from
3732 * ->clear_inode() the inode will get freed
3733 * and concurrent thread which is unlinking
3734 * pa from inode's list may access already
3735 * freed memory, bad-bad-bad */
3737 /* XXX: if this happens too often, we can
3738 * add a flag to force wait only in case
3739 * of ->clear_inode(), but not in case of
3740 * regular truncate */
3741 schedule_timeout_uninterruptible(HZ
);
3744 spin_unlock(&ei
->i_prealloc_lock
);
3746 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3747 BUG_ON(pa
->pa_linear
!= 0);
3748 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
3750 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3751 BUG_ON(err
!= 0); /* error handling here */
3753 bitmap_bh
= read_block_bitmap(sb
, group
);
3754 if (bitmap_bh
== NULL
) {
3755 /* error handling here */
3756 ext4_mb_release_desc(&e4b
);
3757 BUG_ON(bitmap_bh
== NULL
);
3760 ext4_lock_group(sb
, group
);
3761 list_del(&pa
->pa_group_list
);
3762 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3763 ext4_unlock_group(sb
, group
);
3765 ext4_mb_release_desc(&e4b
);
3768 list_del(&pa
->u
.pa_tmp_list
);
3769 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3772 kmem_cache_free(ext4_ac_cachep
, ac
);
3776 * finds all preallocated spaces and return blocks being freed to them
3777 * if preallocated space becomes full (no block is used from the space)
3778 * then the function frees space in buddy
3779 * XXX: at the moment, truncate (which is the only way to free blocks)
3780 * discards all preallocations
3782 static void ext4_mb_return_to_preallocation(struct inode
*inode
,
3783 struct ext4_buddy
*e4b
,
3784 sector_t block
, int count
)
3786 BUG_ON(!list_empty(&EXT4_I(inode
)->i_prealloc_list
));
3789 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3791 struct super_block
*sb
= ac
->ac_sb
;
3794 printk(KERN_ERR
"EXT4-fs: Can't allocate:"
3795 " Allocation context details:\n");
3796 printk(KERN_ERR
"EXT4-fs: status %d flags %d\n",
3797 ac
->ac_status
, ac
->ac_flags
);
3798 printk(KERN_ERR
"EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
3799 "best %lu/%lu/%lu@%lu cr %d\n",
3800 (unsigned long)ac
->ac_o_ex
.fe_group
,
3801 (unsigned long)ac
->ac_o_ex
.fe_start
,
3802 (unsigned long)ac
->ac_o_ex
.fe_len
,
3803 (unsigned long)ac
->ac_o_ex
.fe_logical
,
3804 (unsigned long)ac
->ac_g_ex
.fe_group
,
3805 (unsigned long)ac
->ac_g_ex
.fe_start
,
3806 (unsigned long)ac
->ac_g_ex
.fe_len
,
3807 (unsigned long)ac
->ac_g_ex
.fe_logical
,
3808 (unsigned long)ac
->ac_b_ex
.fe_group
,
3809 (unsigned long)ac
->ac_b_ex
.fe_start
,
3810 (unsigned long)ac
->ac_b_ex
.fe_len
,
3811 (unsigned long)ac
->ac_b_ex
.fe_logical
,
3812 (int)ac
->ac_criteria
);
3813 printk(KERN_ERR
"EXT4-fs: %lu scanned, %d found\n", ac
->ac_ex_scanned
,
3815 printk(KERN_ERR
"EXT4-fs: groups: \n");
3816 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
; i
++) {
3817 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
3818 struct ext4_prealloc_space
*pa
;
3819 ext4_grpblk_t start
;
3820 struct list_head
*cur
;
3821 ext4_lock_group(sb
, i
);
3822 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3823 pa
= list_entry(cur
, struct ext4_prealloc_space
,
3825 spin_lock(&pa
->pa_lock
);
3826 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3828 spin_unlock(&pa
->pa_lock
);
3829 printk(KERN_ERR
"PA:%lu:%d:%u \n", i
,
3832 ext4_unlock_group(sb
, i
);
3834 if (grp
->bb_free
== 0)
3836 printk(KERN_ERR
"%lu: %d/%d \n",
3837 i
, grp
->bb_free
, grp
->bb_fragments
);
3839 printk(KERN_ERR
"\n");
3842 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3849 * We use locality group preallocation for small size file. The size of the
3850 * file is determined by the current size or the resulting size after
3851 * allocation which ever is larger
3853 * One can tune this size via /proc/fs/ext4/<partition>/stream_req
3855 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
3857 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3858 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3861 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3864 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
3865 isize
= i_size_read(ac
->ac_inode
) >> bsbits
;
3866 size
= max(size
, isize
);
3868 /* don't use group allocation for large files */
3869 if (size
>= sbi
->s_mb_stream_request
)
3872 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3875 BUG_ON(ac
->ac_lg
!= NULL
);
3877 * locality group prealloc space are per cpu. The reason for having
3878 * per cpu locality group is to reduce the contention between block
3879 * request from multiple CPUs.
3881 ac
->ac_lg
= &sbi
->s_locality_groups
[get_cpu()];
3884 /* we're going to use group allocation */
3885 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
3887 /* serialize all allocations in the group */
3888 mutex_lock(&ac
->ac_lg
->lg_mutex
);
3891 static noinline_for_stack
int
3892 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
3893 struct ext4_allocation_request
*ar
)
3895 struct super_block
*sb
= ar
->inode
->i_sb
;
3896 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3897 struct ext4_super_block
*es
= sbi
->s_es
;
3901 ext4_grpblk_t block
;
3903 /* we can't allocate > group size */
3906 /* just a dirty hack to filter too big requests */
3907 if (len
>= EXT4_BLOCKS_PER_GROUP(sb
) - 10)
3908 len
= EXT4_BLOCKS_PER_GROUP(sb
) - 10;
3910 /* start searching from the goal */
3912 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
3913 goal
>= ext4_blocks_count(es
))
3914 goal
= le32_to_cpu(es
->s_first_data_block
);
3915 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
3917 /* set up allocation goals */
3918 ac
->ac_b_ex
.fe_logical
= ar
->logical
;
3919 ac
->ac_b_ex
.fe_group
= 0;
3920 ac
->ac_b_ex
.fe_start
= 0;
3921 ac
->ac_b_ex
.fe_len
= 0;
3922 ac
->ac_status
= AC_STATUS_CONTINUE
;
3923 ac
->ac_groups_scanned
= 0;
3924 ac
->ac_ex_scanned
= 0;
3927 ac
->ac_inode
= ar
->inode
;
3928 ac
->ac_o_ex
.fe_logical
= ar
->logical
;
3929 ac
->ac_o_ex
.fe_group
= group
;
3930 ac
->ac_o_ex
.fe_start
= block
;
3931 ac
->ac_o_ex
.fe_len
= len
;
3932 ac
->ac_g_ex
.fe_logical
= ar
->logical
;
3933 ac
->ac_g_ex
.fe_group
= group
;
3934 ac
->ac_g_ex
.fe_start
= block
;
3935 ac
->ac_g_ex
.fe_len
= len
;
3936 ac
->ac_f_ex
.fe_len
= 0;
3937 ac
->ac_flags
= ar
->flags
;
3939 ac
->ac_criteria
= 0;
3941 ac
->ac_bitmap_page
= NULL
;
3942 ac
->ac_buddy_page
= NULL
;
3945 /* we have to define context: we'll we work with a file or
3946 * locality group. this is a policy, actually */
3947 ext4_mb_group_or_file(ac
);
3949 mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
3950 "left: %u/%u, right %u/%u to %swritable\n",
3951 (unsigned) ar
->len
, (unsigned) ar
->logical
,
3952 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
3953 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
3954 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
3955 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
3961 * release all resource we used in allocation
3963 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
3966 if (ac
->ac_pa
->pa_linear
) {
3967 /* see comment in ext4_mb_use_group_pa() */
3968 spin_lock(&ac
->ac_pa
->pa_lock
);
3969 ac
->ac_pa
->pa_pstart
+= ac
->ac_b_ex
.fe_len
;
3970 ac
->ac_pa
->pa_lstart
+= ac
->ac_b_ex
.fe_len
;
3971 ac
->ac_pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
3972 ac
->ac_pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
3973 spin_unlock(&ac
->ac_pa
->pa_lock
);
3975 ext4_mb_put_pa(ac
, ac
->ac_sb
, ac
->ac_pa
);
3977 if (ac
->ac_bitmap_page
)
3978 page_cache_release(ac
->ac_bitmap_page
);
3979 if (ac
->ac_buddy_page
)
3980 page_cache_release(ac
->ac_buddy_page
);
3981 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3982 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
3983 ext4_mb_collect_stats(ac
);
3987 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
3993 for (i
= 0; i
< EXT4_SB(sb
)->s_groups_count
&& needed
> 0; i
++) {
3994 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4003 * Main entry point into mballoc to allocate blocks
4004 * it tries to use preallocation first, then falls back
4005 * to usual allocation
4007 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4008 struct ext4_allocation_request
*ar
, int *errp
)
4010 struct ext4_allocation_context
*ac
= NULL
;
4011 struct ext4_sb_info
*sbi
;
4012 struct super_block
*sb
;
4013 ext4_fsblk_t block
= 0;
4017 sb
= ar
->inode
->i_sb
;
4020 if (!test_opt(sb
, MBALLOC
)) {
4021 block
= ext4_new_blocks_old(handle
, ar
->inode
, ar
->goal
,
4026 while (ar
->len
&& DQUOT_ALLOC_BLOCK(ar
->inode
, ar
->len
)) {
4027 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4036 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4042 ext4_mb_poll_new_transaction(sb
, handle
);
4044 *errp
= ext4_mb_initialize_context(ac
, ar
);
4050 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4051 if (!ext4_mb_use_preallocated(ac
)) {
4053 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4054 ext4_mb_normalize_request(ac
, ar
);
4056 /* allocate space in core */
4057 ext4_mb_regular_allocator(ac
);
4059 /* as we've just preallocated more space than
4060 * user requested orinally, we store allocated
4061 * space in a special descriptor */
4062 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4063 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4064 ext4_mb_new_preallocation(ac
);
4067 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4068 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
);
4069 if (*errp
== -EAGAIN
) {
4070 ac
->ac_b_ex
.fe_group
= 0;
4071 ac
->ac_b_ex
.fe_start
= 0;
4072 ac
->ac_b_ex
.fe_len
= 0;
4073 ac
->ac_status
= AC_STATUS_CONTINUE
;
4076 ac
->ac_b_ex
.fe_len
= 0;
4078 ext4_mb_show_ac(ac
);
4080 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4081 ar
->len
= ac
->ac_b_ex
.fe_len
;
4084 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4088 ac
->ac_b_ex
.fe_len
= 0;
4090 ext4_mb_show_ac(ac
);
4093 ext4_mb_release_context(ac
);
4096 if (ar
->len
< inquota
)
4097 DQUOT_FREE_BLOCK(ar
->inode
, inquota
- ar
->len
);
4099 kmem_cache_free(ext4_ac_cachep
, ac
);
4102 static void ext4_mb_poll_new_transaction(struct super_block
*sb
,
4105 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4107 if (sbi
->s_last_transaction
== handle
->h_transaction
->t_tid
)
4110 /* new transaction! time to close last one and free blocks for
4111 * committed transaction. we know that only transaction can be
4112 * active, so previos transaction can be being logged and we
4113 * know that transaction before previous is known to be already
4114 * logged. this means that now we may free blocks freed in all
4115 * transactions before previous one. hope I'm clear enough ... */
4117 spin_lock(&sbi
->s_md_lock
);
4118 if (sbi
->s_last_transaction
!= handle
->h_transaction
->t_tid
) {
4119 mb_debug("new transaction %lu, old %lu\n",
4120 (unsigned long) handle
->h_transaction
->t_tid
,
4121 (unsigned long) sbi
->s_last_transaction
);
4122 list_splice_init(&sbi
->s_closed_transaction
,
4123 &sbi
->s_committed_transaction
);
4124 list_splice_init(&sbi
->s_active_transaction
,
4125 &sbi
->s_closed_transaction
);
4126 sbi
->s_last_transaction
= handle
->h_transaction
->t_tid
;
4128 spin_unlock(&sbi
->s_md_lock
);
4130 ext4_mb_free_committed_blocks(sb
);
4133 static noinline_for_stack
int
4134 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4135 ext4_group_t group
, ext4_grpblk_t block
, int count
)
4137 struct ext4_group_info
*db
= e4b
->bd_info
;
4138 struct super_block
*sb
= e4b
->bd_sb
;
4139 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4140 struct ext4_free_metadata
*md
;
4143 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4144 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4146 ext4_lock_group(sb
, group
);
4147 for (i
= 0; i
< count
; i
++) {
4149 if (md
&& db
->bb_tid
!= handle
->h_transaction
->t_tid
) {
4150 db
->bb_md_cur
= NULL
;
4155 ext4_unlock_group(sb
, group
);
4156 md
= kmalloc(sizeof(*md
), GFP_NOFS
);
4162 ext4_lock_group(sb
, group
);
4163 if (db
->bb_md_cur
== NULL
) {
4164 spin_lock(&sbi
->s_md_lock
);
4165 list_add(&md
->list
, &sbi
->s_active_transaction
);
4166 spin_unlock(&sbi
->s_md_lock
);
4167 /* protect buddy cache from being freed,
4168 * otherwise we'll refresh it from
4169 * on-disk bitmap and lose not-yet-available
4171 page_cache_get(e4b
->bd_buddy_page
);
4172 page_cache_get(e4b
->bd_bitmap_page
);
4174 db
->bb_tid
= handle
->h_transaction
->t_tid
;
4175 mb_debug("new md 0x%p for group %lu\n",
4183 BUG_ON(md
->num
>= EXT4_BB_MAX_BLOCKS
);
4184 md
->blocks
[md
->num
] = block
+ i
;
4186 if (md
->num
== EXT4_BB_MAX_BLOCKS
) {
4187 /* no more space, put full container on a sb's list */
4188 db
->bb_md_cur
= NULL
;
4191 ext4_unlock_group(sb
, group
);
4196 * Main entry point into mballoc to free blocks
4198 void ext4_mb_free_blocks(handle_t
*handle
, struct inode
*inode
,
4199 unsigned long block
, unsigned long count
,
4200 int metadata
, unsigned long *freed
)
4202 struct buffer_head
*bitmap_bh
= NULL
;
4203 struct super_block
*sb
= inode
->i_sb
;
4204 struct ext4_allocation_context
*ac
= NULL
;
4205 struct ext4_group_desc
*gdp
;
4206 struct ext4_super_block
*es
;
4207 unsigned long overflow
;
4209 struct buffer_head
*gd_bh
;
4210 ext4_group_t block_group
;
4211 struct ext4_sb_info
*sbi
;
4212 struct ext4_buddy e4b
;
4218 ext4_mb_poll_new_transaction(sb
, handle
);
4221 es
= EXT4_SB(sb
)->s_es
;
4222 if (block
< le32_to_cpu(es
->s_first_data_block
) ||
4223 block
+ count
< block
||
4224 block
+ count
> ext4_blocks_count(es
)) {
4225 ext4_error(sb
, __func__
,
4226 "Freeing blocks not in datazone - "
4227 "block = %lu, count = %lu", block
, count
);
4231 ext4_debug("freeing block %lu\n", block
);
4233 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4235 ac
->ac_op
= EXT4_MB_HISTORY_FREE
;
4236 ac
->ac_inode
= inode
;
4242 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4245 * Check to see if we are freeing blocks across a group
4248 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4249 overflow
= bit
+ count
- EXT4_BLOCKS_PER_GROUP(sb
);
4252 bitmap_bh
= read_block_bitmap(sb
, block_group
);
4255 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4259 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4260 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4261 in_range(block
, ext4_inode_table(sb
, gdp
),
4262 EXT4_SB(sb
)->s_itb_per_group
) ||
4263 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4264 EXT4_SB(sb
)->s_itb_per_group
)) {
4266 ext4_error(sb
, __func__
,
4267 "Freeing blocks in system zone - "
4268 "Block = %lu, count = %lu", block
, count
);
4269 /* err = 0. ext4_std_error should be a no op */
4273 BUFFER_TRACE(bitmap_bh
, "getting write access");
4274 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4279 * We are about to modify some metadata. Call the journal APIs
4280 * to unshare ->b_data if a currently-committing transaction is
4283 BUFFER_TRACE(gd_bh
, "get_write_access");
4284 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4288 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4292 #ifdef AGGRESSIVE_CHECK
4295 for (i
= 0; i
< count
; i
++)
4296 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4299 mb_clear_bits(sb_bgl_lock(sbi
, block_group
), bitmap_bh
->b_data
,
4302 /* We dirtied the bitmap block */
4303 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4304 err
= ext4_journal_dirty_metadata(handle
, bitmap_bh
);
4307 ac
->ac_b_ex
.fe_group
= block_group
;
4308 ac
->ac_b_ex
.fe_start
= bit
;
4309 ac
->ac_b_ex
.fe_len
= count
;
4310 ext4_mb_store_history(ac
);
4314 /* blocks being freed are metadata. these blocks shouldn't
4315 * be used until this transaction is committed */
4316 ext4_mb_free_metadata(handle
, &e4b
, block_group
, bit
, count
);
4318 ext4_lock_group(sb
, block_group
);
4319 err
= mb_free_blocks(inode
, &e4b
, bit
, count
);
4320 ext4_mb_return_to_preallocation(inode
, &e4b
, block
, count
);
4321 ext4_unlock_group(sb
, block_group
);
4325 spin_lock(sb_bgl_lock(sbi
, block_group
));
4326 le16_add_cpu(&gdp
->bg_free_blocks_count
, count
);
4327 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, block_group
, gdp
);
4328 spin_unlock(sb_bgl_lock(sbi
, block_group
));
4329 percpu_counter_add(&sbi
->s_freeblocks_counter
, count
);
4331 ext4_mb_release_desc(&e4b
);
4335 /* And the group descriptor block */
4336 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4337 ret
= ext4_journal_dirty_metadata(handle
, gd_bh
);
4341 if (overflow
&& !err
) {
4350 ext4_std_error(sb
, err
);
4352 kmem_cache_free(ext4_ac_cachep
, ac
);