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
25 #include <linux/debugfs.h>
26 #include <linux/slab.h>
27 #include <trace/events/ext4.h>
31 * - test ext4_ext_search_left() and ext4_ext_search_right()
32 * - search for metadata in few groups
35 * - normalization should take into account whether file is still open
36 * - discard preallocations if no free space left (policy?)
37 * - don't normalize tails
39 * - reservation for superuser
42 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
43 * - track min/max extents in each group for better group selection
44 * - mb_mark_used() may allocate chunk right after splitting buddy
45 * - tree of groups sorted by number of free blocks
50 * The allocation request involve request for multiple number of blocks
51 * near to the goal(block) value specified.
53 * During initialization phase of the allocator we decide to use the
54 * group preallocation or inode preallocation depending on the size of
55 * the file. The size of the file could be the resulting file size we
56 * would have after allocation, or the current file size, which ever
57 * is larger. If the size is less than sbi->s_mb_stream_request we
58 * select to use the group preallocation. The default value of
59 * s_mb_stream_request is 16 blocks. This can also be tuned via
60 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
61 * terms of number of blocks.
63 * The main motivation for having small file use group preallocation is to
64 * ensure that we have small files closer together on the disk.
66 * First stage the allocator looks at the inode prealloc list,
67 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
68 * spaces for this particular inode. The inode prealloc space is
71 * pa_lstart -> the logical start block for this prealloc space
72 * pa_pstart -> the physical start block for this prealloc space
73 * pa_len -> length for this prealloc space
74 * pa_free -> free space available in this prealloc space
76 * The inode preallocation space is used looking at the _logical_ start
77 * block. If only the logical file block falls within the range of prealloc
78 * space we will consume the particular prealloc space. This make sure that
79 * that the we have contiguous physical blocks representing the file blocks
81 * The important thing to be noted in case of inode prealloc space is that
82 * we don't modify the values associated to inode prealloc space except
85 * If we are not able to find blocks in the inode prealloc space and if we
86 * have the group allocation flag set then we look at the locality group
87 * prealloc space. These are per CPU prealloc list repreasented as
89 * ext4_sb_info.s_locality_groups[smp_processor_id()]
91 * The reason for having a per cpu locality group is to reduce the contention
92 * between CPUs. It is possible to get scheduled at this point.
94 * The locality group prealloc space is used looking at whether we have
95 * enough free space (pa_free) withing the prealloc space.
97 * If we can't allocate blocks via inode prealloc or/and locality group
98 * prealloc then we look at the buddy cache. The buddy cache is represented
99 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
100 * mapped to the buddy and bitmap information regarding different
101 * groups. The buddy information is attached to buddy cache inode so that
102 * we can access them through the page cache. The information regarding
103 * each group is loaded via ext4_mb_load_buddy. The information involve
104 * block bitmap and buddy information. The information are stored in the
108 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
111 * one block each for bitmap and buddy information. So for each group we
112 * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
113 * blocksize) blocks. So it can have information regarding groups_per_page
114 * which is blocks_per_page/2
116 * The buddy cache inode is not stored on disk. The inode is thrown
117 * away when the filesystem is unmounted.
119 * We look for count number of blocks in the buddy cache. If we were able
120 * to locate that many free blocks we return with additional information
121 * regarding rest of the contiguous physical block available
123 * Before allocating blocks via buddy cache we normalize the request
124 * blocks. This ensure we ask for more blocks that we needed. The extra
125 * blocks that we get after allocation is added to the respective prealloc
126 * list. In case of inode preallocation we follow a list of heuristics
127 * based on file size. This can be found in ext4_mb_normalize_request. If
128 * we are doing a group prealloc we try to normalize the request to
129 * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is
130 * 512 blocks. This can be tuned via
131 * /sys/fs/ext4/<partition/mb_group_prealloc. The value is represented in
132 * terms of number of blocks. If we have mounted the file system with -O
133 * stripe=<value> option the group prealloc request is normalized to the
134 * stripe value (sbi->s_stripe)
136 * The regular allocator(using the buddy cache) supports few tunables.
138 * /sys/fs/ext4/<partition>/mb_min_to_scan
139 * /sys/fs/ext4/<partition>/mb_max_to_scan
140 * /sys/fs/ext4/<partition>/mb_order2_req
142 * The regular allocator uses buddy scan only if the request len is power of
143 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
144 * value of s_mb_order2_reqs can be tuned via
145 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
146 * stripe size (sbi->s_stripe), we try to search for contiguous block in
147 * stripe size. This should result in better allocation on RAID setups. If
148 * not, we search in the specific group using bitmap for best extents. The
149 * tunable min_to_scan and max_to_scan control the behaviour here.
150 * min_to_scan indicate how long the mballoc __must__ look for a best
151 * extent and max_to_scan indicates how long the mballoc __can__ look for a
152 * best extent in the found extents. Searching for the blocks starts with
153 * the group specified as the goal value in allocation context via
154 * ac_g_ex. Each group is first checked based on the criteria whether it
155 * can used for allocation. ext4_mb_good_group explains how the groups are
158 * Both the prealloc space are getting populated as above. So for the first
159 * request we will hit the buddy cache which will result in this prealloc
160 * space getting filled. The prealloc space is then later used for the
161 * subsequent request.
165 * mballoc operates on the following data:
167 * - in-core buddy (actually includes buddy and bitmap)
168 * - preallocation descriptors (PAs)
170 * there are two types of preallocations:
172 * assiged to specific inode and can be used for this inode only.
173 * it describes part of inode's space preallocated to specific
174 * physical blocks. any block from that preallocated can be used
175 * independent. the descriptor just tracks number of blocks left
176 * unused. so, before taking some block from descriptor, one must
177 * make sure corresponded logical block isn't allocated yet. this
178 * also means that freeing any block within descriptor's range
179 * must discard all preallocated blocks.
181 * assigned to specific locality group which does not translate to
182 * permanent set of inodes: inode can join and leave group. space
183 * from this type of preallocation can be used for any inode. thus
184 * it's consumed from the beginning to the end.
186 * relation between them can be expressed as:
187 * in-core buddy = on-disk bitmap + preallocation descriptors
189 * this mean blocks mballoc considers used are:
190 * - allocated blocks (persistent)
191 * - preallocated blocks (non-persistent)
193 * consistency in mballoc world means that at any time a block is either
194 * free or used in ALL structures. notice: "any time" should not be read
195 * literally -- time is discrete and delimited by locks.
197 * to keep it simple, we don't use block numbers, instead we count number of
198 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
200 * all operations can be expressed as:
201 * - init buddy: buddy = on-disk + PAs
202 * - new PA: buddy += N; PA = N
203 * - use inode PA: on-disk += N; PA -= N
204 * - discard inode PA buddy -= on-disk - PA; PA = 0
205 * - use locality group PA on-disk += N; PA -= N
206 * - discard locality group PA buddy -= PA; PA = 0
207 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
208 * is used in real operation because we can't know actual used
209 * bits from PA, only from on-disk bitmap
211 * if we follow this strict logic, then all operations above should be atomic.
212 * given some of them can block, we'd have to use something like semaphores
213 * killing performance on high-end SMP hardware. let's try to relax it using
214 * the following knowledge:
215 * 1) if buddy is referenced, it's already initialized
216 * 2) while block is used in buddy and the buddy is referenced,
217 * nobody can re-allocate that block
218 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
219 * bit set and PA claims same block, it's OK. IOW, one can set bit in
220 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
223 * so, now we're building a concurrency table:
226 * blocks for PA are allocated in the buddy, buddy must be referenced
227 * until PA is linked to allocation group to avoid concurrent buddy init
229 * we need to make sure that either on-disk bitmap or PA has uptodate data
230 * given (3) we care that PA-=N operation doesn't interfere with init
232 * the simplest way would be to have buddy initialized by the discard
233 * - use locality group PA
234 * again PA-=N must be serialized with init
235 * - discard locality group PA
236 * the simplest way would be to have buddy initialized by the discard
239 * i_data_sem serializes them
241 * discard process must wait until PA isn't used by another process
242 * - use locality group PA
243 * some mutex should serialize them
244 * - discard locality group PA
245 * discard process must wait until PA isn't used by another process
248 * i_data_sem or another mutex should serializes them
250 * discard process must wait until PA isn't used by another process
251 * - use locality group PA
252 * nothing wrong here -- they're different PAs covering different blocks
253 * - discard locality group PA
254 * discard process must wait until PA isn't used by another process
256 * now we're ready to make few consequences:
257 * - PA is referenced and while it is no discard is possible
258 * - PA is referenced until block isn't marked in on-disk bitmap
259 * - PA changes only after on-disk bitmap
260 * - discard must not compete with init. either init is done before
261 * any discard or they're serialized somehow
262 * - buddy init as sum of on-disk bitmap and PAs is done atomically
264 * a special case when we've used PA to emptiness. no need to modify buddy
265 * in this case, but we should care about concurrent init
270 * Logic in few words:
275 * mark bits in on-disk bitmap
278 * - use preallocation:
279 * find proper PA (per-inode or group)
281 * mark bits in on-disk bitmap
287 * mark bits in on-disk bitmap
290 * - discard preallocations in group:
292 * move them onto local list
293 * load on-disk bitmap
295 * remove PA from object (inode or locality group)
296 * mark free blocks in-core
298 * - discard inode's preallocations:
305 * - bitlock on a group (group)
306 * - object (inode/locality) (object)
317 * - release consumed pa:
322 * - generate in-core bitmap:
326 * - discard all for given object (inode, locality group):
331 * - discard all for given group:
338 static struct kmem_cache
*ext4_pspace_cachep
;
339 static struct kmem_cache
*ext4_ac_cachep
;
340 static struct kmem_cache
*ext4_free_ext_cachep
;
342 /* We create slab caches for groupinfo data structures based on the
343 * superblock block size. There will be one per mounted filesystem for
344 * each unique s_blocksize_bits */
345 #define NR_GRPINFO_CACHES \
346 (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE + 1)
347 static struct kmem_cache
*ext4_groupinfo_caches
[NR_GRPINFO_CACHES
];
349 static void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
351 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
353 static void release_blocks_on_commit(journal_t
*journal
, transaction_t
*txn
);
355 static inline void *mb_correct_addr_and_bit(int *bit
, void *addr
)
357 #if BITS_PER_LONG == 64
358 *bit
+= ((unsigned long) addr
& 7UL) << 3;
359 addr
= (void *) ((unsigned long) addr
& ~7UL);
360 #elif BITS_PER_LONG == 32
361 *bit
+= ((unsigned long) addr
& 3UL) << 3;
362 addr
= (void *) ((unsigned long) addr
& ~3UL);
364 #error "how many bits you are?!"
369 static inline int mb_test_bit(int bit
, void *addr
)
372 * ext4_test_bit on architecture like powerpc
373 * needs unsigned long aligned address
375 addr
= mb_correct_addr_and_bit(&bit
, addr
);
376 return ext4_test_bit(bit
, addr
);
379 static inline void mb_set_bit(int bit
, void *addr
)
381 addr
= mb_correct_addr_and_bit(&bit
, addr
);
382 ext4_set_bit(bit
, addr
);
385 static inline void mb_clear_bit(int bit
, void *addr
)
387 addr
= mb_correct_addr_and_bit(&bit
, addr
);
388 ext4_clear_bit(bit
, addr
);
391 static inline int mb_find_next_zero_bit(void *addr
, int max
, int start
)
393 int fix
= 0, ret
, tmpmax
;
394 addr
= mb_correct_addr_and_bit(&fix
, addr
);
398 ret
= ext4_find_next_zero_bit(addr
, tmpmax
, start
) - fix
;
404 static inline int mb_find_next_bit(void *addr
, int max
, int start
)
406 int fix
= 0, ret
, tmpmax
;
407 addr
= mb_correct_addr_and_bit(&fix
, addr
);
411 ret
= ext4_find_next_bit(addr
, tmpmax
, start
) - fix
;
417 static void *mb_find_buddy(struct ext4_buddy
*e4b
, int order
, int *max
)
421 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
424 if (order
> e4b
->bd_blkbits
+ 1) {
429 /* at order 0 we see each particular block */
430 *max
= 1 << (e4b
->bd_blkbits
+ 3);
432 return EXT4_MB_BITMAP(e4b
);
434 bb
= EXT4_MB_BUDDY(e4b
) + EXT4_SB(e4b
->bd_sb
)->s_mb_offsets
[order
];
435 *max
= EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[order
];
441 static void mb_free_blocks_double(struct inode
*inode
, struct ext4_buddy
*e4b
,
442 int first
, int count
)
445 struct super_block
*sb
= e4b
->bd_sb
;
447 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
449 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
450 for (i
= 0; i
< count
; i
++) {
451 if (!mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
)) {
452 ext4_fsblk_t blocknr
;
454 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
455 blocknr
+= first
+ i
;
456 ext4_grp_locked_error(sb
, e4b
->bd_group
,
457 inode
? inode
->i_ino
: 0,
459 "freeing block already freed "
463 mb_clear_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
467 static void mb_mark_used_double(struct ext4_buddy
*e4b
, int first
, int count
)
471 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
473 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
474 for (i
= 0; i
< count
; i
++) {
475 BUG_ON(mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
));
476 mb_set_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
480 static void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
482 if (memcmp(e4b
->bd_info
->bb_bitmap
, bitmap
, e4b
->bd_sb
->s_blocksize
)) {
483 unsigned char *b1
, *b2
;
485 b1
= (unsigned char *) e4b
->bd_info
->bb_bitmap
;
486 b2
= (unsigned char *) bitmap
;
487 for (i
= 0; i
< e4b
->bd_sb
->s_blocksize
; i
++) {
488 if (b1
[i
] != b2
[i
]) {
489 printk(KERN_ERR
"corruption in group %u "
490 "at byte %u(%u): %x in copy != %x "
491 "on disk/prealloc\n",
492 e4b
->bd_group
, i
, i
* 8, b1
[i
], b2
[i
]);
500 static inline void mb_free_blocks_double(struct inode
*inode
,
501 struct ext4_buddy
*e4b
, int first
, int count
)
505 static inline void mb_mark_used_double(struct ext4_buddy
*e4b
,
506 int first
, int count
)
510 static inline void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
516 #ifdef AGGRESSIVE_CHECK
518 #define MB_CHECK_ASSERT(assert) \
522 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
523 function, file, line, # assert); \
528 static int __mb_check_buddy(struct ext4_buddy
*e4b
, char *file
,
529 const char *function
, int line
)
531 struct super_block
*sb
= e4b
->bd_sb
;
532 int order
= e4b
->bd_blkbits
+ 1;
539 struct ext4_group_info
*grp
;
542 struct list_head
*cur
;
547 static int mb_check_counter
;
548 if (mb_check_counter
++ % 100 != 0)
553 buddy
= mb_find_buddy(e4b
, order
, &max
);
554 MB_CHECK_ASSERT(buddy
);
555 buddy2
= mb_find_buddy(e4b
, order
- 1, &max2
);
556 MB_CHECK_ASSERT(buddy2
);
557 MB_CHECK_ASSERT(buddy
!= buddy2
);
558 MB_CHECK_ASSERT(max
* 2 == max2
);
561 for (i
= 0; i
< max
; i
++) {
563 if (mb_test_bit(i
, buddy
)) {
564 /* only single bit in buddy2 may be 1 */
565 if (!mb_test_bit(i
<< 1, buddy2
)) {
567 mb_test_bit((i
<<1)+1, buddy2
));
568 } else if (!mb_test_bit((i
<< 1) + 1, buddy2
)) {
570 mb_test_bit(i
<< 1, buddy2
));
575 /* both bits in buddy2 must be 0 */
576 MB_CHECK_ASSERT(mb_test_bit(i
<< 1, buddy2
));
577 MB_CHECK_ASSERT(mb_test_bit((i
<< 1) + 1, buddy2
));
579 for (j
= 0; j
< (1 << order
); j
++) {
580 k
= (i
* (1 << order
)) + j
;
582 !mb_test_bit(k
, EXT4_MB_BITMAP(e4b
)));
586 MB_CHECK_ASSERT(e4b
->bd_info
->bb_counters
[order
] == count
);
591 buddy
= mb_find_buddy(e4b
, 0, &max
);
592 for (i
= 0; i
< max
; i
++) {
593 if (!mb_test_bit(i
, buddy
)) {
594 MB_CHECK_ASSERT(i
>= e4b
->bd_info
->bb_first_free
);
602 /* check used bits only */
603 for (j
= 0; j
< e4b
->bd_blkbits
+ 1; j
++) {
604 buddy2
= mb_find_buddy(e4b
, j
, &max2
);
606 MB_CHECK_ASSERT(k
< max2
);
607 MB_CHECK_ASSERT(mb_test_bit(k
, buddy2
));
610 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b
->bd_info
));
611 MB_CHECK_ASSERT(e4b
->bd_info
->bb_fragments
== fragments
);
613 grp
= ext4_get_group_info(sb
, e4b
->bd_group
);
614 buddy
= mb_find_buddy(e4b
, 0, &max
);
615 list_for_each(cur
, &grp
->bb_prealloc_list
) {
616 ext4_group_t groupnr
;
617 struct ext4_prealloc_space
*pa
;
618 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
619 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &groupnr
, &k
);
620 MB_CHECK_ASSERT(groupnr
== e4b
->bd_group
);
621 for (i
= 0; i
< pa
->pa_len
; i
++)
622 MB_CHECK_ASSERT(mb_test_bit(k
+ i
, buddy
));
626 #undef MB_CHECK_ASSERT
627 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
628 __FILE__, __func__, __LINE__)
630 #define mb_check_buddy(e4b)
633 /* FIXME!! need more doc */
634 static void ext4_mb_mark_free_simple(struct super_block
*sb
,
635 void *buddy
, ext4_grpblk_t first
, ext4_grpblk_t len
,
636 struct ext4_group_info
*grp
)
638 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
642 unsigned short border
;
644 BUG_ON(len
> EXT4_BLOCKS_PER_GROUP(sb
));
646 border
= 2 << sb
->s_blocksize_bits
;
649 /* find how many blocks can be covered since this position */
650 max
= ffs(first
| border
) - 1;
652 /* find how many blocks of power 2 we need to mark */
659 /* mark multiblock chunks only */
660 grp
->bb_counters
[min
]++;
662 mb_clear_bit(first
>> min
,
663 buddy
+ sbi
->s_mb_offsets
[min
]);
671 * Cache the order of the largest free extent we have available in this block
675 mb_set_largest_free_order(struct super_block
*sb
, struct ext4_group_info
*grp
)
680 grp
->bb_largest_free_order
= -1; /* uninit */
682 bits
= sb
->s_blocksize_bits
+ 1;
683 for (i
= bits
; i
>= 0; i
--) {
684 if (grp
->bb_counters
[i
] > 0) {
685 grp
->bb_largest_free_order
= i
;
691 static noinline_for_stack
692 void ext4_mb_generate_buddy(struct super_block
*sb
,
693 void *buddy
, void *bitmap
, ext4_group_t group
)
695 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
696 ext4_grpblk_t max
= EXT4_BLOCKS_PER_GROUP(sb
);
701 unsigned fragments
= 0;
702 unsigned long long period
= get_cycles();
704 /* initialize buddy from bitmap which is aggregation
705 * of on-disk bitmap and preallocations */
706 i
= mb_find_next_zero_bit(bitmap
, max
, 0);
707 grp
->bb_first_free
= i
;
711 i
= mb_find_next_bit(bitmap
, max
, i
);
715 ext4_mb_mark_free_simple(sb
, buddy
, first
, len
, grp
);
717 grp
->bb_counters
[0]++;
719 i
= mb_find_next_zero_bit(bitmap
, max
, i
);
721 grp
->bb_fragments
= fragments
;
723 if (free
!= grp
->bb_free
) {
724 ext4_grp_locked_error(sb
, group
, 0, 0,
725 "%u blocks in bitmap, %u in gd",
728 * If we intent to continue, we consider group descritor
729 * corrupt and update bb_free using bitmap value
733 mb_set_largest_free_order(sb
, grp
);
735 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
, &(grp
->bb_state
));
737 period
= get_cycles() - period
;
738 spin_lock(&EXT4_SB(sb
)->s_bal_lock
);
739 EXT4_SB(sb
)->s_mb_buddies_generated
++;
740 EXT4_SB(sb
)->s_mb_generation_time
+= period
;
741 spin_unlock(&EXT4_SB(sb
)->s_bal_lock
);
744 /* The buddy information is attached the buddy cache inode
745 * for convenience. The information regarding each group
746 * is loaded via ext4_mb_load_buddy. The information involve
747 * block bitmap and buddy information. The information are
748 * stored in the inode as
751 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
754 * one block each for bitmap and buddy information.
755 * So for each group we take up 2 blocks. A page can
756 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
757 * So it can have information regarding groups_per_page which
758 * is blocks_per_page/2
760 * Locking note: This routine takes the block group lock of all groups
761 * for this page; do not hold this lock when calling this routine!
764 static int ext4_mb_init_cache(struct page
*page
, char *incore
)
766 ext4_group_t ngroups
;
772 ext4_group_t first_group
;
774 struct super_block
*sb
;
775 struct buffer_head
*bhs
;
776 struct buffer_head
**bh
;
781 mb_debug(1, "init page %lu\n", page
->index
);
783 inode
= page
->mapping
->host
;
785 ngroups
= ext4_get_groups_count(sb
);
786 blocksize
= 1 << inode
->i_blkbits
;
787 blocks_per_page
= PAGE_CACHE_SIZE
/ blocksize
;
789 groups_per_page
= blocks_per_page
>> 1;
790 if (groups_per_page
== 0)
793 /* allocate buffer_heads to read bitmaps */
794 if (groups_per_page
> 1) {
796 i
= sizeof(struct buffer_head
*) * groups_per_page
;
797 bh
= kzalloc(i
, GFP_NOFS
);
803 first_group
= page
->index
* blocks_per_page
/ 2;
805 /* read all groups the page covers into the cache */
806 for (i
= 0; i
< groups_per_page
; i
++) {
807 struct ext4_group_desc
*desc
;
809 if (first_group
+ i
>= ngroups
)
813 desc
= ext4_get_group_desc(sb
, first_group
+ i
, NULL
);
818 bh
[i
] = sb_getblk(sb
, ext4_block_bitmap(sb
, desc
));
822 if (bitmap_uptodate(bh
[i
]))
826 if (bitmap_uptodate(bh
[i
])) {
827 unlock_buffer(bh
[i
]);
830 ext4_lock_group(sb
, first_group
+ i
);
831 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
832 ext4_init_block_bitmap(sb
, bh
[i
],
833 first_group
+ i
, desc
);
834 set_bitmap_uptodate(bh
[i
]);
835 set_buffer_uptodate(bh
[i
]);
836 ext4_unlock_group(sb
, first_group
+ i
);
837 unlock_buffer(bh
[i
]);
840 ext4_unlock_group(sb
, first_group
+ i
);
841 if (buffer_uptodate(bh
[i
])) {
843 * if not uninit if bh is uptodate,
844 * bitmap is also uptodate
846 set_bitmap_uptodate(bh
[i
]);
847 unlock_buffer(bh
[i
]);
852 * submit the buffer_head for read. We can
853 * safely mark the bitmap as uptodate now.
854 * We do it here so the bitmap uptodate bit
855 * get set with buffer lock held.
857 set_bitmap_uptodate(bh
[i
]);
858 bh
[i
]->b_end_io
= end_buffer_read_sync
;
859 submit_bh(READ
, bh
[i
]);
860 mb_debug(1, "read bitmap for group %u\n", first_group
+ i
);
863 /* wait for I/O completion */
864 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
865 wait_on_buffer(bh
[i
]);
868 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
869 if (!buffer_uptodate(bh
[i
]))
873 first_block
= page
->index
* blocks_per_page
;
875 memset(page_address(page
), 0xff, PAGE_CACHE_SIZE
);
876 for (i
= 0; i
< blocks_per_page
; i
++) {
878 struct ext4_group_info
*grinfo
;
880 group
= (first_block
+ i
) >> 1;
881 if (group
>= ngroups
)
885 * data carry information regarding this
886 * particular group in the format specified
890 data
= page_address(page
) + (i
* blocksize
);
891 bitmap
= bh
[group
- first_group
]->b_data
;
894 * We place the buddy block and bitmap block
897 if ((first_block
+ i
) & 1) {
898 /* this is block of buddy */
899 BUG_ON(incore
== NULL
);
900 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
901 group
, page
->index
, i
* blocksize
);
902 trace_ext4_mb_buddy_bitmap_load(sb
, group
);
903 grinfo
= ext4_get_group_info(sb
, group
);
904 grinfo
->bb_fragments
= 0;
905 memset(grinfo
->bb_counters
, 0,
906 sizeof(*grinfo
->bb_counters
) *
907 (sb
->s_blocksize_bits
+2));
909 * incore got set to the group block bitmap below
911 ext4_lock_group(sb
, group
);
912 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
913 ext4_unlock_group(sb
, group
);
916 /* this is block of bitmap */
917 BUG_ON(incore
!= NULL
);
918 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
919 group
, page
->index
, i
* blocksize
);
920 trace_ext4_mb_bitmap_load(sb
, group
);
922 /* see comments in ext4_mb_put_pa() */
923 ext4_lock_group(sb
, group
);
924 memcpy(data
, bitmap
, blocksize
);
926 /* mark all preallocated blks used in in-core bitmap */
927 ext4_mb_generate_from_pa(sb
, data
, group
);
928 ext4_mb_generate_from_freelist(sb
, data
, group
);
929 ext4_unlock_group(sb
, group
);
931 /* set incore so that the buddy information can be
932 * generated using this
937 SetPageUptodate(page
);
941 for (i
= 0; i
< groups_per_page
&& bh
[i
]; i
++)
950 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
951 * block group lock of all groups for this page; do not hold the BG lock when
952 * calling this routine!
954 static noinline_for_stack
955 int ext4_mb_init_group(struct super_block
*sb
, ext4_group_t group
)
961 int block
, pnum
, poff
;
962 int num_grp_locked
= 0;
963 struct ext4_group_info
*this_grp
;
964 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
965 struct inode
*inode
= sbi
->s_buddy_cache
;
966 struct page
*page
= NULL
, *bitmap_page
= NULL
;
968 mb_debug(1, "init group %u\n", group
);
969 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
970 this_grp
= ext4_get_group_info(sb
, group
);
972 * This ensures that we don't reinit the buddy cache
973 * page which map to the group from which we are already
974 * allocating. If we are looking at the buddy cache we would
975 * have taken a reference using ext4_mb_load_buddy and that
976 * would have taken the alloc_sem lock.
978 num_grp_locked
= ext4_mb_get_buddy_cache_lock(sb
, group
);
979 if (!EXT4_MB_GRP_NEED_INIT(this_grp
)) {
981 * somebody initialized the group
982 * return without doing anything
988 * the buddy cache inode stores the block bitmap
989 * and buddy information in consecutive blocks.
990 * So for each group we need two blocks.
993 pnum
= block
/ blocks_per_page
;
994 poff
= block
% blocks_per_page
;
995 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
997 BUG_ON(page
->mapping
!= inode
->i_mapping
);
998 ret
= ext4_mb_init_cache(page
, NULL
);
1005 if (page
== NULL
|| !PageUptodate(page
)) {
1009 mark_page_accessed(page
);
1011 bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1013 /* init buddy cache */
1015 pnum
= block
/ blocks_per_page
;
1016 poff
= block
% blocks_per_page
;
1017 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1018 if (page
== bitmap_page
) {
1020 * If both the bitmap and buddy are in
1021 * the same page we don't need to force
1026 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1027 ret
= ext4_mb_init_cache(page
, bitmap
);
1034 if (page
== NULL
|| !PageUptodate(page
)) {
1038 mark_page_accessed(page
);
1040 ext4_mb_put_buddy_cache_lock(sb
, group
, num_grp_locked
);
1042 page_cache_release(bitmap_page
);
1044 page_cache_release(page
);
1049 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1050 * block group lock of all groups for this page; do not hold the BG lock when
1051 * calling this routine!
1053 static noinline_for_stack
int
1054 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
1055 struct ext4_buddy
*e4b
)
1057 int blocks_per_page
;
1063 struct ext4_group_info
*grp
;
1064 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1065 struct inode
*inode
= sbi
->s_buddy_cache
;
1067 mb_debug(1, "load group %u\n", group
);
1069 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1070 grp
= ext4_get_group_info(sb
, group
);
1072 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
1073 e4b
->bd_info
= ext4_get_group_info(sb
, group
);
1075 e4b
->bd_group
= group
;
1076 e4b
->bd_buddy_page
= NULL
;
1077 e4b
->bd_bitmap_page
= NULL
;
1078 e4b
->alloc_semp
= &grp
->alloc_sem
;
1080 /* Take the read lock on the group alloc
1081 * sem. This would make sure a parallel
1082 * ext4_mb_init_group happening on other
1083 * groups mapped by the page is blocked
1084 * till we are done with allocation
1087 down_read(e4b
->alloc_semp
);
1089 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1090 /* we need to check for group need init flag
1091 * with alloc_semp held so that we can be sure
1092 * that new blocks didn't get added to the group
1093 * when we are loading the buddy cache
1095 up_read(e4b
->alloc_semp
);
1097 * we need full data about the group
1098 * to make a good selection
1100 ret
= ext4_mb_init_group(sb
, group
);
1103 goto repeat_load_buddy
;
1107 * the buddy cache inode stores the block bitmap
1108 * and buddy information in consecutive blocks.
1109 * So for each group we need two blocks.
1112 pnum
= block
/ blocks_per_page
;
1113 poff
= block
% blocks_per_page
;
1115 /* we could use find_or_create_page(), but it locks page
1116 * what we'd like to avoid in fast path ... */
1117 page
= find_get_page(inode
->i_mapping
, pnum
);
1118 if (page
== NULL
|| !PageUptodate(page
)) {
1121 * drop the page reference and try
1122 * to get the page with lock. If we
1123 * are not uptodate that implies
1124 * somebody just created the page but
1125 * is yet to initialize the same. So
1126 * wait for it to initialize.
1128 page_cache_release(page
);
1129 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1131 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1132 if (!PageUptodate(page
)) {
1133 ret
= ext4_mb_init_cache(page
, NULL
);
1138 mb_cmp_bitmaps(e4b
, page_address(page
) +
1139 (poff
* sb
->s_blocksize
));
1144 if (page
== NULL
|| !PageUptodate(page
)) {
1148 e4b
->bd_bitmap_page
= page
;
1149 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1150 mark_page_accessed(page
);
1153 pnum
= block
/ blocks_per_page
;
1154 poff
= block
% blocks_per_page
;
1156 page
= find_get_page(inode
->i_mapping
, pnum
);
1157 if (page
== NULL
|| !PageUptodate(page
)) {
1159 page_cache_release(page
);
1160 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1162 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1163 if (!PageUptodate(page
)) {
1164 ret
= ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
1173 if (page
== NULL
|| !PageUptodate(page
)) {
1177 e4b
->bd_buddy_page
= page
;
1178 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
1179 mark_page_accessed(page
);
1181 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
1182 BUG_ON(e4b
->bd_buddy_page
== NULL
);
1187 if (e4b
->bd_bitmap_page
)
1188 page_cache_release(e4b
->bd_bitmap_page
);
1189 if (e4b
->bd_buddy_page
)
1190 page_cache_release(e4b
->bd_buddy_page
);
1191 e4b
->bd_buddy
= NULL
;
1192 e4b
->bd_bitmap
= NULL
;
1194 /* Done with the buddy cache */
1195 up_read(e4b
->alloc_semp
);
1199 static void ext4_mb_unload_buddy(struct ext4_buddy
*e4b
)
1201 if (e4b
->bd_bitmap_page
)
1202 page_cache_release(e4b
->bd_bitmap_page
);
1203 if (e4b
->bd_buddy_page
)
1204 page_cache_release(e4b
->bd_buddy_page
);
1205 /* Done with the buddy cache */
1206 if (e4b
->alloc_semp
)
1207 up_read(e4b
->alloc_semp
);
1211 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
1216 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
1217 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
1219 bb
= EXT4_MB_BUDDY(e4b
);
1220 while (order
<= e4b
->bd_blkbits
+ 1) {
1222 if (!mb_test_bit(block
, bb
)) {
1223 /* this block is part of buddy of order 'order' */
1226 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1232 static void mb_clear_bits(void *bm
, int cur
, int len
)
1238 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1239 /* fast path: clear whole word at once */
1240 addr
= bm
+ (cur
>> 3);
1245 mb_clear_bit(cur
, bm
);
1250 static void mb_set_bits(void *bm
, int cur
, int len
)
1256 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1257 /* fast path: set whole word at once */
1258 addr
= bm
+ (cur
>> 3);
1263 mb_set_bit(cur
, bm
);
1268 static void mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1269 int first
, int count
)
1276 struct super_block
*sb
= e4b
->bd_sb
;
1278 BUG_ON(first
+ count
> (sb
->s_blocksize
<< 3));
1279 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
1280 mb_check_buddy(e4b
);
1281 mb_free_blocks_double(inode
, e4b
, first
, count
);
1283 e4b
->bd_info
->bb_free
+= count
;
1284 if (first
< e4b
->bd_info
->bb_first_free
)
1285 e4b
->bd_info
->bb_first_free
= first
;
1287 /* let's maintain fragments counter */
1289 block
= !mb_test_bit(first
- 1, EXT4_MB_BITMAP(e4b
));
1290 if (first
+ count
< EXT4_SB(sb
)->s_mb_maxs
[0])
1291 max
= !mb_test_bit(first
+ count
, EXT4_MB_BITMAP(e4b
));
1293 e4b
->bd_info
->bb_fragments
--;
1294 else if (!block
&& !max
)
1295 e4b
->bd_info
->bb_fragments
++;
1297 /* let's maintain buddy itself */
1298 while (count
-- > 0) {
1302 if (!mb_test_bit(block
, EXT4_MB_BITMAP(e4b
))) {
1303 ext4_fsblk_t blocknr
;
1305 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1307 ext4_grp_locked_error(sb
, e4b
->bd_group
,
1308 inode
? inode
->i_ino
: 0,
1310 "freeing already freed block "
1313 mb_clear_bit(block
, EXT4_MB_BITMAP(e4b
));
1314 e4b
->bd_info
->bb_counters
[order
]++;
1316 /* start of the buddy */
1317 buddy
= mb_find_buddy(e4b
, order
, &max
);
1321 if (mb_test_bit(block
, buddy
) ||
1322 mb_test_bit(block
+ 1, buddy
))
1325 /* both the buddies are free, try to coalesce them */
1326 buddy2
= mb_find_buddy(e4b
, order
+ 1, &max
);
1332 /* for special purposes, we don't set
1333 * free bits in bitmap */
1334 mb_set_bit(block
, buddy
);
1335 mb_set_bit(block
+ 1, buddy
);
1337 e4b
->bd_info
->bb_counters
[order
]--;
1338 e4b
->bd_info
->bb_counters
[order
]--;
1342 e4b
->bd_info
->bb_counters
[order
]++;
1344 mb_clear_bit(block
, buddy2
);
1348 mb_set_largest_free_order(sb
, e4b
->bd_info
);
1349 mb_check_buddy(e4b
);
1352 static int mb_find_extent(struct ext4_buddy
*e4b
, int order
, int block
,
1353 int needed
, struct ext4_free_extent
*ex
)
1360 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1363 buddy
= mb_find_buddy(e4b
, order
, &max
);
1364 BUG_ON(buddy
== NULL
);
1365 BUG_ON(block
>= max
);
1366 if (mb_test_bit(block
, buddy
)) {
1373 /* FIXME dorp order completely ? */
1374 if (likely(order
== 0)) {
1375 /* find actual order */
1376 order
= mb_find_order_for_block(e4b
, block
);
1377 block
= block
>> order
;
1380 ex
->fe_len
= 1 << order
;
1381 ex
->fe_start
= block
<< order
;
1382 ex
->fe_group
= e4b
->bd_group
;
1384 /* calc difference from given start */
1385 next
= next
- ex
->fe_start
;
1387 ex
->fe_start
+= next
;
1389 while (needed
> ex
->fe_len
&&
1390 (buddy
= mb_find_buddy(e4b
, order
, &max
))) {
1392 if (block
+ 1 >= max
)
1395 next
= (block
+ 1) * (1 << order
);
1396 if (mb_test_bit(next
, EXT4_MB_BITMAP(e4b
)))
1399 ord
= mb_find_order_for_block(e4b
, next
);
1402 block
= next
>> order
;
1403 ex
->fe_len
+= 1 << order
;
1406 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1410 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1416 int start
= ex
->fe_start
;
1417 int len
= ex
->fe_len
;
1422 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1423 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1424 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1425 mb_check_buddy(e4b
);
1426 mb_mark_used_double(e4b
, start
, len
);
1428 e4b
->bd_info
->bb_free
-= len
;
1429 if (e4b
->bd_info
->bb_first_free
== start
)
1430 e4b
->bd_info
->bb_first_free
+= len
;
1432 /* let's maintain fragments counter */
1434 mlen
= !mb_test_bit(start
- 1, EXT4_MB_BITMAP(e4b
));
1435 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1436 max
= !mb_test_bit(start
+ len
, EXT4_MB_BITMAP(e4b
));
1438 e4b
->bd_info
->bb_fragments
++;
1439 else if (!mlen
&& !max
)
1440 e4b
->bd_info
->bb_fragments
--;
1442 /* let's maintain buddy itself */
1444 ord
= mb_find_order_for_block(e4b
, start
);
1446 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1447 /* the whole chunk may be allocated at once! */
1449 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1450 BUG_ON((start
>> ord
) >= max
);
1451 mb_set_bit(start
>> ord
, buddy
);
1452 e4b
->bd_info
->bb_counters
[ord
]--;
1459 /* store for history */
1461 ret
= len
| (ord
<< 16);
1463 /* we have to split large buddy */
1465 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1466 mb_set_bit(start
>> ord
, buddy
);
1467 e4b
->bd_info
->bb_counters
[ord
]--;
1470 cur
= (start
>> ord
) & ~1U;
1471 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1472 mb_clear_bit(cur
, buddy
);
1473 mb_clear_bit(cur
+ 1, buddy
);
1474 e4b
->bd_info
->bb_counters
[ord
]++;
1475 e4b
->bd_info
->bb_counters
[ord
]++;
1477 mb_set_largest_free_order(e4b
->bd_sb
, e4b
->bd_info
);
1479 mb_set_bits(EXT4_MB_BITMAP(e4b
), ex
->fe_start
, len0
);
1480 mb_check_buddy(e4b
);
1486 * Must be called under group lock!
1488 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1489 struct ext4_buddy
*e4b
)
1491 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1494 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1495 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1497 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1498 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1499 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1501 /* preallocation can change ac_b_ex, thus we store actually
1502 * allocated blocks for history */
1503 ac
->ac_f_ex
= ac
->ac_b_ex
;
1505 ac
->ac_status
= AC_STATUS_FOUND
;
1506 ac
->ac_tail
= ret
& 0xffff;
1507 ac
->ac_buddy
= ret
>> 16;
1510 * take the page reference. We want the page to be pinned
1511 * so that we don't get a ext4_mb_init_cache_call for this
1512 * group until we update the bitmap. That would mean we
1513 * double allocate blocks. The reference is dropped
1514 * in ext4_mb_release_context
1516 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1517 get_page(ac
->ac_bitmap_page
);
1518 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1519 get_page(ac
->ac_buddy_page
);
1520 /* on allocation we use ac to track the held semaphore */
1521 ac
->alloc_semp
= e4b
->alloc_semp
;
1522 e4b
->alloc_semp
= NULL
;
1523 /* store last allocated for subsequent stream allocation */
1524 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
1525 spin_lock(&sbi
->s_md_lock
);
1526 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1527 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1528 spin_unlock(&sbi
->s_md_lock
);
1533 * regular allocator, for general purposes allocation
1536 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1537 struct ext4_buddy
*e4b
,
1540 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1541 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1542 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1543 struct ext4_free_extent ex
;
1546 if (ac
->ac_status
== AC_STATUS_FOUND
)
1549 * We don't want to scan for a whole year
1551 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1552 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1553 ac
->ac_status
= AC_STATUS_BREAK
;
1558 * Haven't found good chunk so far, let's continue
1560 if (bex
->fe_len
< gex
->fe_len
)
1563 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1564 && bex
->fe_group
== e4b
->bd_group
) {
1565 /* recheck chunk's availability - we don't know
1566 * when it was found (within this lock-unlock
1568 max
= mb_find_extent(e4b
, 0, bex
->fe_start
, gex
->fe_len
, &ex
);
1569 if (max
>= gex
->fe_len
) {
1570 ext4_mb_use_best_found(ac
, e4b
);
1577 * The routine checks whether found extent is good enough. If it is,
1578 * then the extent gets marked used and flag is set to the context
1579 * to stop scanning. Otherwise, the extent is compared with the
1580 * previous found extent and if new one is better, then it's stored
1581 * in the context. Later, the best found extent will be used, if
1582 * mballoc can't find good enough extent.
1584 * FIXME: real allocation policy is to be designed yet!
1586 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1587 struct ext4_free_extent
*ex
,
1588 struct ext4_buddy
*e4b
)
1590 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1591 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1593 BUG_ON(ex
->fe_len
<= 0);
1594 BUG_ON(ex
->fe_len
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1595 BUG_ON(ex
->fe_start
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1596 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1601 * The special case - take what you catch first
1603 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1605 ext4_mb_use_best_found(ac
, e4b
);
1610 * Let's check whether the chuck is good enough
1612 if (ex
->fe_len
== gex
->fe_len
) {
1614 ext4_mb_use_best_found(ac
, e4b
);
1619 * If this is first found extent, just store it in the context
1621 if (bex
->fe_len
== 0) {
1627 * If new found extent is better, store it in the context
1629 if (bex
->fe_len
< gex
->fe_len
) {
1630 /* if the request isn't satisfied, any found extent
1631 * larger than previous best one is better */
1632 if (ex
->fe_len
> bex
->fe_len
)
1634 } else if (ex
->fe_len
> gex
->fe_len
) {
1635 /* if the request is satisfied, then we try to find
1636 * an extent that still satisfy the request, but is
1637 * smaller than previous one */
1638 if (ex
->fe_len
< bex
->fe_len
)
1642 ext4_mb_check_limits(ac
, e4b
, 0);
1645 static noinline_for_stack
1646 int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1647 struct ext4_buddy
*e4b
)
1649 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1650 ext4_group_t group
= ex
.fe_group
;
1654 BUG_ON(ex
.fe_len
<= 0);
1655 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1659 ext4_lock_group(ac
->ac_sb
, group
);
1660 max
= mb_find_extent(e4b
, 0, ex
.fe_start
, ex
.fe_len
, &ex
);
1664 ext4_mb_use_best_found(ac
, e4b
);
1667 ext4_unlock_group(ac
->ac_sb
, group
);
1668 ext4_mb_unload_buddy(e4b
);
1673 static noinline_for_stack
1674 int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1675 struct ext4_buddy
*e4b
)
1677 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1680 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1681 struct ext4_free_extent ex
;
1683 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1686 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1690 ext4_lock_group(ac
->ac_sb
, group
);
1691 max
= mb_find_extent(e4b
, 0, ac
->ac_g_ex
.fe_start
,
1692 ac
->ac_g_ex
.fe_len
, &ex
);
1694 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1697 start
= ext4_group_first_block_no(ac
->ac_sb
, e4b
->bd_group
) +
1699 /* use do_div to get remainder (would be 64-bit modulo) */
1700 if (do_div(start
, sbi
->s_stripe
) == 0) {
1703 ext4_mb_use_best_found(ac
, e4b
);
1705 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1706 BUG_ON(ex
.fe_len
<= 0);
1707 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1708 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1711 ext4_mb_use_best_found(ac
, e4b
);
1712 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1713 /* Sometimes, caller may want to merge even small
1714 * number of blocks to an existing extent */
1715 BUG_ON(ex
.fe_len
<= 0);
1716 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1717 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1720 ext4_mb_use_best_found(ac
, e4b
);
1722 ext4_unlock_group(ac
->ac_sb
, group
);
1723 ext4_mb_unload_buddy(e4b
);
1729 * The routine scans buddy structures (not bitmap!) from given order
1730 * to max order and tries to find big enough chunk to satisfy the req
1732 static noinline_for_stack
1733 void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1734 struct ext4_buddy
*e4b
)
1736 struct super_block
*sb
= ac
->ac_sb
;
1737 struct ext4_group_info
*grp
= e4b
->bd_info
;
1743 BUG_ON(ac
->ac_2order
<= 0);
1744 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1745 if (grp
->bb_counters
[i
] == 0)
1748 buddy
= mb_find_buddy(e4b
, i
, &max
);
1749 BUG_ON(buddy
== NULL
);
1751 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1756 ac
->ac_b_ex
.fe_len
= 1 << i
;
1757 ac
->ac_b_ex
.fe_start
= k
<< i
;
1758 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1760 ext4_mb_use_best_found(ac
, e4b
);
1762 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1764 if (EXT4_SB(sb
)->s_mb_stats
)
1765 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1772 * The routine scans the group and measures all found extents.
1773 * In order to optimize scanning, caller must pass number of
1774 * free blocks in the group, so the routine can know upper limit.
1776 static noinline_for_stack
1777 void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1778 struct ext4_buddy
*e4b
)
1780 struct super_block
*sb
= ac
->ac_sb
;
1781 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1782 struct ext4_free_extent ex
;
1786 free
= e4b
->bd_info
->bb_free
;
1789 i
= e4b
->bd_info
->bb_first_free
;
1791 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1792 i
= mb_find_next_zero_bit(bitmap
,
1793 EXT4_BLOCKS_PER_GROUP(sb
), i
);
1794 if (i
>= EXT4_BLOCKS_PER_GROUP(sb
)) {
1796 * IF we have corrupt bitmap, we won't find any
1797 * free blocks even though group info says we
1798 * we have free blocks
1800 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1801 "%d free blocks as per "
1802 "group info. But bitmap says 0",
1807 mb_find_extent(e4b
, 0, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1808 BUG_ON(ex
.fe_len
<= 0);
1809 if (free
< ex
.fe_len
) {
1810 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1811 "%d free blocks as per "
1812 "group info. But got %d blocks",
1815 * The number of free blocks differs. This mostly
1816 * indicate that the bitmap is corrupt. So exit
1817 * without claiming the space.
1822 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1828 ext4_mb_check_limits(ac
, e4b
, 1);
1832 * This is a special case for storages like raid5
1833 * we try to find stripe-aligned chunks for stripe-size-multiple requests
1835 static noinline_for_stack
1836 void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1837 struct ext4_buddy
*e4b
)
1839 struct super_block
*sb
= ac
->ac_sb
;
1840 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1841 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1842 struct ext4_free_extent ex
;
1843 ext4_fsblk_t first_group_block
;
1848 BUG_ON(sbi
->s_stripe
== 0);
1850 /* find first stripe-aligned block in group */
1851 first_group_block
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1853 a
= first_group_block
+ sbi
->s_stripe
- 1;
1854 do_div(a
, sbi
->s_stripe
);
1855 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1857 while (i
< EXT4_BLOCKS_PER_GROUP(sb
)) {
1858 if (!mb_test_bit(i
, bitmap
)) {
1859 max
= mb_find_extent(e4b
, 0, i
, sbi
->s_stripe
, &ex
);
1860 if (max
>= sbi
->s_stripe
) {
1863 ext4_mb_use_best_found(ac
, e4b
);
1871 /* This is now called BEFORE we load the buddy bitmap. */
1872 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
1873 ext4_group_t group
, int cr
)
1875 unsigned free
, fragments
;
1876 int flex_size
= ext4_flex_bg_size(EXT4_SB(ac
->ac_sb
));
1877 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1879 BUG_ON(cr
< 0 || cr
>= 4);
1881 /* We only do this if the grp has never been initialized */
1882 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1883 int ret
= ext4_mb_init_group(ac
->ac_sb
, group
);
1888 free
= grp
->bb_free
;
1889 fragments
= grp
->bb_fragments
;
1897 BUG_ON(ac
->ac_2order
== 0);
1899 if (grp
->bb_largest_free_order
< ac
->ac_2order
)
1902 /* Avoid using the first bg of a flexgroup for data files */
1903 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
) &&
1904 (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) &&
1905 ((group
% flex_size
) == 0))
1910 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
1914 if (free
>= ac
->ac_g_ex
.fe_len
)
1927 * lock the group_info alloc_sem of all the groups
1928 * belonging to the same buddy cache page. This
1929 * make sure other parallel operation on the buddy
1930 * cache doesn't happen whild holding the buddy cache
1933 int ext4_mb_get_buddy_cache_lock(struct super_block
*sb
, ext4_group_t group
)
1937 int blocks_per_page
;
1938 int groups_per_page
;
1939 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
1940 ext4_group_t first_group
;
1941 struct ext4_group_info
*grp
;
1943 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1945 * the buddy cache inode stores the block bitmap
1946 * and buddy information in consecutive blocks.
1947 * So for each group we need two blocks.
1950 pnum
= block
/ blocks_per_page
;
1951 first_group
= pnum
* blocks_per_page
/ 2;
1953 groups_per_page
= blocks_per_page
>> 1;
1954 if (groups_per_page
== 0)
1955 groups_per_page
= 1;
1956 /* read all groups the page covers into the cache */
1957 for (i
= 0; i
< groups_per_page
; i
++) {
1959 if ((first_group
+ i
) >= ngroups
)
1961 grp
= ext4_get_group_info(sb
, first_group
+ i
);
1962 /* take all groups write allocation
1963 * semaphore. This make sure there is
1964 * no block allocation going on in any
1967 down_write_nested(&grp
->alloc_sem
, i
);
1972 void ext4_mb_put_buddy_cache_lock(struct super_block
*sb
,
1973 ext4_group_t group
, int locked_group
)
1977 int blocks_per_page
;
1978 ext4_group_t first_group
;
1979 struct ext4_group_info
*grp
;
1981 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1983 * the buddy cache inode stores the block bitmap
1984 * and buddy information in consecutive blocks.
1985 * So for each group we need two blocks.
1988 pnum
= block
/ blocks_per_page
;
1989 first_group
= pnum
* blocks_per_page
/ 2;
1990 /* release locks on all the groups */
1991 for (i
= 0; i
< locked_group
; i
++) {
1993 grp
= ext4_get_group_info(sb
, first_group
+ i
);
1994 /* take all groups write allocation
1995 * semaphore. This make sure there is
1996 * no block allocation going on in any
1999 up_write(&grp
->alloc_sem
);
2004 static noinline_for_stack
int
2005 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
2007 ext4_group_t ngroups
, group
, i
;
2010 struct ext4_sb_info
*sbi
;
2011 struct super_block
*sb
;
2012 struct ext4_buddy e4b
;
2016 ngroups
= ext4_get_groups_count(sb
);
2017 /* non-extent files are limited to low blocks/groups */
2018 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)))
2019 ngroups
= sbi
->s_blockfile_groups
;
2021 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
2023 /* first, try the goal */
2024 err
= ext4_mb_find_by_goal(ac
, &e4b
);
2025 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
2028 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2032 * ac->ac2_order is set only if the fe_len is a power of 2
2033 * if ac2_order is set we also set criteria to 0 so that we
2034 * try exact allocation using buddy.
2036 i
= fls(ac
->ac_g_ex
.fe_len
);
2039 * We search using buddy data only if the order of the request
2040 * is greater than equal to the sbi_s_mb_order2_reqs
2041 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2043 if (i
>= sbi
->s_mb_order2_reqs
) {
2045 * This should tell if fe_len is exactly power of 2
2047 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
2048 ac
->ac_2order
= i
- 1;
2051 /* if stream allocation is enabled, use global goal */
2052 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
2053 /* TBD: may be hot point */
2054 spin_lock(&sbi
->s_md_lock
);
2055 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
2056 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
2057 spin_unlock(&sbi
->s_md_lock
);
2060 /* Let's just scan groups to find more-less suitable blocks */
2061 cr
= ac
->ac_2order
? 0 : 1;
2063 * cr == 0 try to get exact allocation,
2064 * cr == 3 try to get anything
2067 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
2068 ac
->ac_criteria
= cr
;
2070 * searching for the right group start
2071 * from the goal value specified
2073 group
= ac
->ac_g_ex
.fe_group
;
2075 for (i
= 0; i
< ngroups
; group
++, i
++) {
2076 if (group
== ngroups
)
2079 /* This now checks without needing the buddy page */
2080 if (!ext4_mb_good_group(ac
, group
, cr
))
2083 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2087 ext4_lock_group(sb
, group
);
2090 * We need to check again after locking the
2093 if (!ext4_mb_good_group(ac
, group
, cr
)) {
2094 ext4_unlock_group(sb
, group
);
2095 ext4_mb_unload_buddy(&e4b
);
2099 ac
->ac_groups_scanned
++;
2101 ext4_mb_simple_scan_group(ac
, &e4b
);
2102 else if (cr
== 1 && sbi
->s_stripe
&&
2103 !(ac
->ac_g_ex
.fe_len
% sbi
->s_stripe
))
2104 ext4_mb_scan_aligned(ac
, &e4b
);
2106 ext4_mb_complex_scan_group(ac
, &e4b
);
2108 ext4_unlock_group(sb
, group
);
2109 ext4_mb_unload_buddy(&e4b
);
2111 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
2116 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
2117 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
2119 * We've been searching too long. Let's try to allocate
2120 * the best chunk we've found so far
2123 ext4_mb_try_best_found(ac
, &e4b
);
2124 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
2126 * Someone more lucky has already allocated it.
2127 * The only thing we can do is just take first
2129 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2131 ac
->ac_b_ex
.fe_group
= 0;
2132 ac
->ac_b_ex
.fe_start
= 0;
2133 ac
->ac_b_ex
.fe_len
= 0;
2134 ac
->ac_status
= AC_STATUS_CONTINUE
;
2135 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
2137 atomic_inc(&sbi
->s_mb_lost_chunks
);
2145 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2147 struct super_block
*sb
= seq
->private;
2150 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2153 return (void *) ((unsigned long) group
);
2156 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2158 struct super_block
*sb
= seq
->private;
2162 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2165 return (void *) ((unsigned long) group
);
2168 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2170 struct super_block
*sb
= seq
->private;
2171 ext4_group_t group
= (ext4_group_t
) ((unsigned long) v
);
2174 struct ext4_buddy e4b
;
2176 struct ext4_group_info info
;
2177 ext4_grpblk_t counters
[16];
2182 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2183 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2184 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2185 "group", "free", "frags", "first",
2186 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2187 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2189 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2190 sizeof(struct ext4_group_info
);
2191 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2193 seq_printf(seq
, "#%-5u: I/O error\n", group
);
2196 ext4_lock_group(sb
, group
);
2197 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2198 ext4_unlock_group(sb
, group
);
2199 ext4_mb_unload_buddy(&e4b
);
2201 seq_printf(seq
, "#%-5u: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2202 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2203 for (i
= 0; i
<= 13; i
++)
2204 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2205 sg
.info
.bb_counters
[i
] : 0);
2206 seq_printf(seq
, " ]\n");
2211 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2215 static const struct seq_operations ext4_mb_seq_groups_ops
= {
2216 .start
= ext4_mb_seq_groups_start
,
2217 .next
= ext4_mb_seq_groups_next
,
2218 .stop
= ext4_mb_seq_groups_stop
,
2219 .show
= ext4_mb_seq_groups_show
,
2222 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2224 struct super_block
*sb
= PDE(inode
)->data
;
2227 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2229 struct seq_file
*m
= file
->private_data
;
2236 static const struct file_operations ext4_mb_seq_groups_fops
= {
2237 .owner
= THIS_MODULE
,
2238 .open
= ext4_mb_seq_groups_open
,
2240 .llseek
= seq_lseek
,
2241 .release
= seq_release
,
2244 static struct kmem_cache
*get_groupinfo_cache(int blocksize_bits
)
2246 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2247 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[cache_index
];
2253 /* Create and initialize ext4_group_info data for the given group. */
2254 int ext4_mb_add_groupinfo(struct super_block
*sb
, ext4_group_t group
,
2255 struct ext4_group_desc
*desc
)
2259 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2260 struct ext4_group_info
**meta_group_info
;
2261 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2264 * First check if this group is the first of a reserved block.
2265 * If it's true, we have to allocate a new table of pointers
2266 * to ext4_group_info structures
2268 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2269 metalen
= sizeof(*meta_group_info
) <<
2270 EXT4_DESC_PER_BLOCK_BITS(sb
);
2271 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2272 if (meta_group_info
== NULL
) {
2273 printk(KERN_ERR
"EXT4-fs: can't allocate mem for a "
2275 goto exit_meta_group_info
;
2277 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] =
2282 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2283 i
= group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2285 meta_group_info
[i
] = kmem_cache_alloc(cachep
, GFP_KERNEL
);
2286 if (meta_group_info
[i
] == NULL
) {
2287 printk(KERN_ERR
"EXT4-fs: can't allocate buddy mem\n");
2288 goto exit_group_info
;
2290 memset(meta_group_info
[i
], 0, kmem_cache_size(cachep
));
2291 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2292 &(meta_group_info
[i
]->bb_state
));
2295 * initialize bb_free to be able to skip
2296 * empty groups without initialization
2298 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2299 meta_group_info
[i
]->bb_free
=
2300 ext4_free_blocks_after_init(sb
, group
, desc
);
2302 meta_group_info
[i
]->bb_free
=
2303 ext4_free_blks_count(sb
, desc
);
2306 INIT_LIST_HEAD(&meta_group_info
[i
]->bb_prealloc_list
);
2307 init_rwsem(&meta_group_info
[i
]->alloc_sem
);
2308 meta_group_info
[i
]->bb_free_root
= RB_ROOT
;
2309 meta_group_info
[i
]->bb_largest_free_order
= -1; /* uninit */
2313 struct buffer_head
*bh
;
2314 meta_group_info
[i
]->bb_bitmap
=
2315 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2316 BUG_ON(meta_group_info
[i
]->bb_bitmap
== NULL
);
2317 bh
= ext4_read_block_bitmap(sb
, group
);
2319 memcpy(meta_group_info
[i
]->bb_bitmap
, bh
->b_data
,
2328 /* If a meta_group_info table has been allocated, release it now */
2329 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0)
2330 kfree(sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)]);
2331 exit_meta_group_info
:
2333 } /* ext4_mb_add_groupinfo */
2335 static int ext4_mb_init_backend(struct super_block
*sb
)
2337 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2339 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2340 struct ext4_super_block
*es
= sbi
->s_es
;
2341 int num_meta_group_infos
;
2342 int num_meta_group_infos_max
;
2344 struct ext4_group_desc
*desc
;
2345 struct kmem_cache
*cachep
;
2347 /* This is the number of blocks used by GDT */
2348 num_meta_group_infos
= (ngroups
+ EXT4_DESC_PER_BLOCK(sb
) -
2349 1) >> EXT4_DESC_PER_BLOCK_BITS(sb
);
2352 * This is the total number of blocks used by GDT including
2353 * the number of reserved blocks for GDT.
2354 * The s_group_info array is allocated with this value
2355 * to allow a clean online resize without a complex
2356 * manipulation of pointer.
2357 * The drawback is the unused memory when no resize
2358 * occurs but it's very low in terms of pages
2359 * (see comments below)
2360 * Need to handle this properly when META_BG resizing is allowed
2362 num_meta_group_infos_max
= num_meta_group_infos
+
2363 le16_to_cpu(es
->s_reserved_gdt_blocks
);
2366 * array_size is the size of s_group_info array. We round it
2367 * to the next power of two because this approximation is done
2368 * internally by kmalloc so we can have some more memory
2369 * for free here (e.g. may be used for META_BG resize).
2372 while (array_size
< sizeof(*sbi
->s_group_info
) *
2373 num_meta_group_infos_max
)
2374 array_size
= array_size
<< 1;
2375 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2376 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2377 * So a two level scheme suffices for now. */
2378 sbi
->s_group_info
= kmalloc(array_size
, GFP_KERNEL
);
2379 if (sbi
->s_group_info
== NULL
) {
2380 printk(KERN_ERR
"EXT4-fs: can't allocate buddy meta group\n");
2383 sbi
->s_buddy_cache
= new_inode(sb
);
2384 if (sbi
->s_buddy_cache
== NULL
) {
2385 printk(KERN_ERR
"EXT4-fs: can't get new inode\n");
2388 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2389 for (i
= 0; i
< ngroups
; i
++) {
2390 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2393 "EXT4-fs: can't read descriptor %u\n", i
);
2396 if (ext4_mb_add_groupinfo(sb
, i
, desc
) != 0)
2403 cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2405 kmem_cache_free(cachep
, ext4_get_group_info(sb
, i
));
2406 i
= num_meta_group_infos
;
2408 kfree(sbi
->s_group_info
[i
]);
2409 iput(sbi
->s_buddy_cache
);
2411 kfree(sbi
->s_group_info
);
2415 int ext4_mb_init(struct super_block
*sb
, int needs_recovery
)
2417 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2423 struct kmem_cache
*cachep
;
2426 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_offsets
);
2428 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2429 if (sbi
->s_mb_offsets
== NULL
) {
2434 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_maxs
);
2435 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2436 if (sbi
->s_mb_maxs
== NULL
) {
2441 cache_index
= sb
->s_blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2442 cachep
= ext4_groupinfo_caches
[cache_index
];
2445 int len
= offsetof(struct ext4_group_info
,
2446 bb_counters
[sb
->s_blocksize_bits
+ 2]);
2448 sprintf(name
, "ext4_groupinfo_%d", sb
->s_blocksize_bits
);
2449 namep
= kstrdup(name
, GFP_KERNEL
);
2455 /* Need to free the kmem_cache_name() when we
2456 * destroy the slab */
2457 cachep
= kmem_cache_create(namep
, len
, 0,
2458 SLAB_RECLAIM_ACCOUNT
, NULL
);
2463 ext4_groupinfo_caches
[cache_index
] = cachep
;
2466 /* order 0 is regular bitmap */
2467 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2468 sbi
->s_mb_offsets
[0] = 0;
2472 max
= sb
->s_blocksize
<< 2;
2474 sbi
->s_mb_offsets
[i
] = offset
;
2475 sbi
->s_mb_maxs
[i
] = max
;
2476 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2479 } while (i
<= sb
->s_blocksize_bits
+ 1);
2481 /* init file for buddy data */
2482 ret
= ext4_mb_init_backend(sb
);
2487 spin_lock_init(&sbi
->s_md_lock
);
2488 spin_lock_init(&sbi
->s_bal_lock
);
2490 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2491 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2492 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2493 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2494 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2495 sbi
->s_mb_group_prealloc
= MB_DEFAULT_GROUP_PREALLOC
;
2497 sbi
->s_locality_groups
= alloc_percpu(struct ext4_locality_group
);
2498 if (sbi
->s_locality_groups
== NULL
) {
2502 for_each_possible_cpu(i
) {
2503 struct ext4_locality_group
*lg
;
2504 lg
= per_cpu_ptr(sbi
->s_locality_groups
, i
);
2505 mutex_init(&lg
->lg_mutex
);
2506 for (j
= 0; j
< PREALLOC_TB_SIZE
; j
++)
2507 INIT_LIST_HEAD(&lg
->lg_prealloc_list
[j
]);
2508 spin_lock_init(&lg
->lg_prealloc_lock
);
2512 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_proc
,
2513 &ext4_mb_seq_groups_fops
, sb
);
2516 sbi
->s_journal
->j_commit_callback
= release_blocks_on_commit
;
2519 kfree(sbi
->s_mb_offsets
);
2520 kfree(sbi
->s_mb_maxs
);
2526 /* need to called with the ext4 group lock held */
2527 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2529 struct ext4_prealloc_space
*pa
;
2530 struct list_head
*cur
, *tmp
;
2533 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2534 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2535 list_del(&pa
->pa_group_list
);
2537 kmem_cache_free(ext4_pspace_cachep
, pa
);
2540 mb_debug(1, "mballoc: %u PAs left\n", count
);
2544 int ext4_mb_release(struct super_block
*sb
)
2546 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2548 int num_meta_group_infos
;
2549 struct ext4_group_info
*grinfo
;
2550 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2551 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2553 if (sbi
->s_group_info
) {
2554 for (i
= 0; i
< ngroups
; i
++) {
2555 grinfo
= ext4_get_group_info(sb
, i
);
2557 kfree(grinfo
->bb_bitmap
);
2559 ext4_lock_group(sb
, i
);
2560 ext4_mb_cleanup_pa(grinfo
);
2561 ext4_unlock_group(sb
, i
);
2562 kmem_cache_free(cachep
, grinfo
);
2564 num_meta_group_infos
= (ngroups
+
2565 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2566 EXT4_DESC_PER_BLOCK_BITS(sb
);
2567 for (i
= 0; i
< num_meta_group_infos
; i
++)
2568 kfree(sbi
->s_group_info
[i
]);
2569 kfree(sbi
->s_group_info
);
2571 kfree(sbi
->s_mb_offsets
);
2572 kfree(sbi
->s_mb_maxs
);
2573 if (sbi
->s_buddy_cache
)
2574 iput(sbi
->s_buddy_cache
);
2575 if (sbi
->s_mb_stats
) {
2577 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2578 atomic_read(&sbi
->s_bal_allocated
),
2579 atomic_read(&sbi
->s_bal_reqs
),
2580 atomic_read(&sbi
->s_bal_success
));
2582 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2583 "%u 2^N hits, %u breaks, %u lost\n",
2584 atomic_read(&sbi
->s_bal_ex_scanned
),
2585 atomic_read(&sbi
->s_bal_goals
),
2586 atomic_read(&sbi
->s_bal_2orders
),
2587 atomic_read(&sbi
->s_bal_breaks
),
2588 atomic_read(&sbi
->s_mb_lost_chunks
));
2590 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2591 sbi
->s_mb_buddies_generated
++,
2592 sbi
->s_mb_generation_time
);
2594 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2595 atomic_read(&sbi
->s_mb_preallocated
),
2596 atomic_read(&sbi
->s_mb_discarded
));
2599 free_percpu(sbi
->s_locality_groups
);
2601 remove_proc_entry("mb_groups", sbi
->s_proc
);
2606 static inline void ext4_issue_discard(struct super_block
*sb
,
2607 ext4_group_t block_group
, ext4_grpblk_t block
, int count
)
2610 ext4_fsblk_t discard_block
;
2612 discard_block
= block
+ ext4_group_first_block_no(sb
, block_group
);
2613 trace_ext4_discard_blocks(sb
,
2614 (unsigned long long) discard_block
, count
);
2615 ret
= sb_issue_discard(sb
, discard_block
, count
);
2616 if (ret
== -EOPNOTSUPP
) {
2617 ext4_warning(sb
, "discard not supported, disabling");
2618 clear_opt(EXT4_SB(sb
)->s_mount_opt
, DISCARD
);
2623 * This function is called by the jbd2 layer once the commit has finished,
2624 * so we know we can free the blocks that were released with that commit.
2626 static void release_blocks_on_commit(journal_t
*journal
, transaction_t
*txn
)
2628 struct super_block
*sb
= journal
->j_private
;
2629 struct ext4_buddy e4b
;
2630 struct ext4_group_info
*db
;
2631 int err
, count
= 0, count2
= 0;
2632 struct ext4_free_data
*entry
;
2633 struct list_head
*l
, *ltmp
;
2635 list_for_each_safe(l
, ltmp
, &txn
->t_private_list
) {
2636 entry
= list_entry(l
, struct ext4_free_data
, list
);
2638 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2639 entry
->count
, entry
->group
, entry
);
2641 if (test_opt(sb
, DISCARD
))
2642 ext4_issue_discard(sb
, entry
->group
,
2643 entry
->start_blk
, entry
->count
);
2645 err
= ext4_mb_load_buddy(sb
, entry
->group
, &e4b
);
2646 /* we expect to find existing buddy because it's pinned */
2650 /* there are blocks to put in buddy to make them really free */
2651 count
+= entry
->count
;
2653 ext4_lock_group(sb
, entry
->group
);
2654 /* Take it out of per group rb tree */
2655 rb_erase(&entry
->node
, &(db
->bb_free_root
));
2656 mb_free_blocks(NULL
, &e4b
, entry
->start_blk
, entry
->count
);
2658 if (!db
->bb_free_root
.rb_node
) {
2659 /* No more items in the per group rb tree
2660 * balance refcounts from ext4_mb_free_metadata()
2662 page_cache_release(e4b
.bd_buddy_page
);
2663 page_cache_release(e4b
.bd_bitmap_page
);
2665 ext4_unlock_group(sb
, entry
->group
);
2666 kmem_cache_free(ext4_free_ext_cachep
, entry
);
2667 ext4_mb_unload_buddy(&e4b
);
2670 mb_debug(1, "freed %u blocks in %u structures\n", count
, count2
);
2673 #ifdef CONFIG_EXT4_DEBUG
2674 u8 mb_enable_debug __read_mostly
;
2676 static struct dentry
*debugfs_dir
;
2677 static struct dentry
*debugfs_debug
;
2679 static void __init
ext4_create_debugfs_entry(void)
2681 debugfs_dir
= debugfs_create_dir("ext4", NULL
);
2683 debugfs_debug
= debugfs_create_u8("mballoc-debug",
2689 static void ext4_remove_debugfs_entry(void)
2691 debugfs_remove(debugfs_debug
);
2692 debugfs_remove(debugfs_dir
);
2697 static void __init
ext4_create_debugfs_entry(void)
2701 static void ext4_remove_debugfs_entry(void)
2707 int __init
init_ext4_mballoc(void)
2709 ext4_pspace_cachep
=
2710 kmem_cache_create("ext4_prealloc_space",
2711 sizeof(struct ext4_prealloc_space
),
2712 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2713 if (ext4_pspace_cachep
== NULL
)
2717 kmem_cache_create("ext4_alloc_context",
2718 sizeof(struct ext4_allocation_context
),
2719 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2720 if (ext4_ac_cachep
== NULL
) {
2721 kmem_cache_destroy(ext4_pspace_cachep
);
2725 ext4_free_ext_cachep
=
2726 kmem_cache_create("ext4_free_block_extents",
2727 sizeof(struct ext4_free_data
),
2728 0, SLAB_RECLAIM_ACCOUNT
, NULL
);
2729 if (ext4_free_ext_cachep
== NULL
) {
2730 kmem_cache_destroy(ext4_pspace_cachep
);
2731 kmem_cache_destroy(ext4_ac_cachep
);
2734 ext4_create_debugfs_entry();
2738 void exit_ext4_mballoc(void)
2742 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2743 * before destroying the slab cache.
2746 kmem_cache_destroy(ext4_pspace_cachep
);
2747 kmem_cache_destroy(ext4_ac_cachep
);
2748 kmem_cache_destroy(ext4_free_ext_cachep
);
2750 for (i
= 0; i
< NR_GRPINFO_CACHES
; i
++) {
2751 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[i
];
2753 char *name
= (char *)kmem_cache_name(cachep
);
2754 kmem_cache_destroy(cachep
);
2758 ext4_remove_debugfs_entry();
2763 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2764 * Returns 0 if success or error code
2766 static noinline_for_stack
int
2767 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2768 handle_t
*handle
, unsigned int reserv_blks
)
2770 struct buffer_head
*bitmap_bh
= NULL
;
2771 struct ext4_group_desc
*gdp
;
2772 struct buffer_head
*gdp_bh
;
2773 struct ext4_sb_info
*sbi
;
2774 struct super_block
*sb
;
2778 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2779 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2785 bitmap_bh
= ext4_read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2789 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2794 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2798 ext4_debug("using block group %u(%d)\n", ac
->ac_b_ex
.fe_group
,
2799 ext4_free_blks_count(sb
, gdp
));
2801 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2805 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
2807 len
= ac
->ac_b_ex
.fe_len
;
2808 if (!ext4_data_block_valid(sbi
, block
, len
)) {
2809 ext4_error(sb
, "Allocating blocks %llu-%llu which overlap "
2810 "fs metadata\n", block
, block
+len
);
2811 /* File system mounted not to panic on error
2812 * Fix the bitmap and repeat the block allocation
2813 * We leak some of the blocks here.
2815 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2816 mb_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2817 ac
->ac_b_ex
.fe_len
);
2818 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2819 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2825 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2826 #ifdef AGGRESSIVE_CHECK
2829 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2830 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2831 bitmap_bh
->b_data
));
2835 mb_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,ac
->ac_b_ex
.fe_len
);
2836 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2837 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2838 ext4_free_blks_set(sb
, gdp
,
2839 ext4_free_blocks_after_init(sb
,
2840 ac
->ac_b_ex
.fe_group
, gdp
));
2842 len
= ext4_free_blks_count(sb
, gdp
) - ac
->ac_b_ex
.fe_len
;
2843 ext4_free_blks_set(sb
, gdp
, len
);
2844 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, ac
->ac_b_ex
.fe_group
, gdp
);
2846 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2847 percpu_counter_sub(&sbi
->s_freeblocks_counter
, ac
->ac_b_ex
.fe_len
);
2849 * Now reduce the dirty block count also. Should not go negative
2851 if (!(ac
->ac_flags
& EXT4_MB_DELALLOC_RESERVED
))
2852 /* release all the reserved blocks if non delalloc */
2853 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, reserv_blks
);
2855 if (sbi
->s_log_groups_per_flex
) {
2856 ext4_group_t flex_group
= ext4_flex_group(sbi
,
2857 ac
->ac_b_ex
.fe_group
);
2858 atomic_sub(ac
->ac_b_ex
.fe_len
,
2859 &sbi
->s_flex_groups
[flex_group
].free_blocks
);
2862 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2865 err
= ext4_handle_dirty_metadata(handle
, NULL
, gdp_bh
);
2868 ext4_mark_super_dirty(sb
);
2874 * here we normalize request for locality group
2875 * Group request are normalized to s_strip size if we set the same via mount
2876 * option. If not we set it to s_mb_group_prealloc which can be configured via
2877 * /sys/fs/ext4/<partition>/mb_group_prealloc
2879 * XXX: should we try to preallocate more than the group has now?
2881 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2883 struct super_block
*sb
= ac
->ac_sb
;
2884 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2887 if (EXT4_SB(sb
)->s_stripe
)
2888 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_stripe
;
2890 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2891 mb_debug(1, "#%u: goal %u blocks for locality group\n",
2892 current
->pid
, ac
->ac_g_ex
.fe_len
);
2896 * Normalization means making request better in terms of
2897 * size and alignment
2899 static noinline_for_stack
void
2900 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
2901 struct ext4_allocation_request
*ar
)
2905 loff_t size
, orig_size
, start_off
;
2907 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
2908 struct ext4_prealloc_space
*pa
;
2910 /* do normalize only data requests, metadata requests
2911 do not need preallocation */
2912 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
2915 /* sometime caller may want exact blocks */
2916 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2919 /* caller may indicate that preallocation isn't
2920 * required (it's a tail, for example) */
2921 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
2924 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
2925 ext4_mb_normalize_group_request(ac
);
2929 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
2931 /* first, let's learn actual file size
2932 * given current request is allocated */
2933 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
2934 size
= size
<< bsbits
;
2935 if (size
< i_size_read(ac
->ac_inode
))
2936 size
= i_size_read(ac
->ac_inode
);
2939 /* max size of free chunks */
2942 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
2943 (req <= (size) || max <= (chunk_size))
2945 /* first, try to predict filesize */
2946 /* XXX: should this table be tunable? */
2948 if (size
<= 16 * 1024) {
2950 } else if (size
<= 32 * 1024) {
2952 } else if (size
<= 64 * 1024) {
2954 } else if (size
<= 128 * 1024) {
2956 } else if (size
<= 256 * 1024) {
2958 } else if (size
<= 512 * 1024) {
2960 } else if (size
<= 1024 * 1024) {
2962 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
2963 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2964 (21 - bsbits
)) << 21;
2965 size
= 2 * 1024 * 1024;
2966 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
2967 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2968 (22 - bsbits
)) << 22;
2969 size
= 4 * 1024 * 1024;
2970 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
2971 (8<<20)>>bsbits
, max
, 8 * 1024)) {
2972 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2973 (23 - bsbits
)) << 23;
2974 size
= 8 * 1024 * 1024;
2976 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
2977 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
2979 size
= size
>> bsbits
;
2980 start
= start_off
>> bsbits
;
2982 /* don't cover already allocated blocks in selected range */
2983 if (ar
->pleft
&& start
<= ar
->lleft
) {
2984 size
-= ar
->lleft
+ 1 - start
;
2985 start
= ar
->lleft
+ 1;
2987 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
2988 size
-= start
+ size
- ar
->lright
;
2992 /* check we don't cross already preallocated blocks */
2994 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
2999 spin_lock(&pa
->pa_lock
);
3000 if (pa
->pa_deleted
) {
3001 spin_unlock(&pa
->pa_lock
);
3005 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
3007 /* PA must not overlap original request */
3008 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
3009 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
3011 /* skip PAs this normalized request doesn't overlap with */
3012 if (pa
->pa_lstart
>= end
|| pa_end
<= start
) {
3013 spin_unlock(&pa
->pa_lock
);
3016 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
3018 /* adjust start or end to be adjacent to this pa */
3019 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
3020 BUG_ON(pa_end
< start
);
3022 } else if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
3023 BUG_ON(pa
->pa_lstart
> end
);
3024 end
= pa
->pa_lstart
;
3026 spin_unlock(&pa
->pa_lock
);
3031 /* XXX: extra loop to check we really don't overlap preallocations */
3033 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3035 spin_lock(&pa
->pa_lock
);
3036 if (pa
->pa_deleted
== 0) {
3037 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
3038 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3040 spin_unlock(&pa
->pa_lock
);
3044 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3045 start
> ac
->ac_o_ex
.fe_logical
) {
3046 printk(KERN_ERR
"start %lu, size %lu, fe_logical %lu\n",
3047 (unsigned long) start
, (unsigned long) size
,
3048 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3050 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3051 start
> ac
->ac_o_ex
.fe_logical
);
3052 BUG_ON(size
<= 0 || size
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3054 /* now prepare goal request */
3056 /* XXX: is it better to align blocks WRT to logical
3057 * placement or satisfy big request as is */
3058 ac
->ac_g_ex
.fe_logical
= start
;
3059 ac
->ac_g_ex
.fe_len
= size
;
3061 /* define goal start in order to merge */
3062 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3063 /* merge to the right */
3064 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3065 &ac
->ac_f_ex
.fe_group
,
3066 &ac
->ac_f_ex
.fe_start
);
3067 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3069 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3070 /* merge to the left */
3071 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3072 &ac
->ac_f_ex
.fe_group
,
3073 &ac
->ac_f_ex
.fe_start
);
3074 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3077 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3078 (unsigned) orig_size
, (unsigned) start
);
3081 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3083 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3085 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3086 atomic_inc(&sbi
->s_bal_reqs
);
3087 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3088 if (ac
->ac_b_ex
.fe_len
>= ac
->ac_o_ex
.fe_len
)
3089 atomic_inc(&sbi
->s_bal_success
);
3090 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3091 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3092 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3093 atomic_inc(&sbi
->s_bal_goals
);
3094 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3095 atomic_inc(&sbi
->s_bal_breaks
);
3098 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
)
3099 trace_ext4_mballoc_alloc(ac
);
3101 trace_ext4_mballoc_prealloc(ac
);
3105 * Called on failure; free up any blocks from the inode PA for this
3106 * context. We don't need this for MB_GROUP_PA because we only change
3107 * pa_free in ext4_mb_release_context(), but on failure, we've already
3108 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3110 static void ext4_discard_allocated_blocks(struct ext4_allocation_context
*ac
)
3112 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
3115 if (pa
&& pa
->pa_type
== MB_INODE_PA
) {
3116 len
= ac
->ac_b_ex
.fe_len
;
3123 * use blocks preallocated to inode
3125 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3126 struct ext4_prealloc_space
*pa
)
3132 /* found preallocated blocks, use them */
3133 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3134 end
= min(pa
->pa_pstart
+ pa
->pa_len
, start
+ ac
->ac_o_ex
.fe_len
);
3136 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3137 &ac
->ac_b_ex
.fe_start
);
3138 ac
->ac_b_ex
.fe_len
= len
;
3139 ac
->ac_status
= AC_STATUS_FOUND
;
3142 BUG_ON(start
< pa
->pa_pstart
);
3143 BUG_ON(start
+ len
> pa
->pa_pstart
+ pa
->pa_len
);
3144 BUG_ON(pa
->pa_free
< len
);
3147 mb_debug(1, "use %llu/%u from inode pa %p\n", start
, len
, pa
);
3151 * use blocks preallocated to locality group
3153 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3154 struct ext4_prealloc_space
*pa
)
3156 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3158 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3159 &ac
->ac_b_ex
.fe_group
,
3160 &ac
->ac_b_ex
.fe_start
);
3161 ac
->ac_b_ex
.fe_len
= len
;
3162 ac
->ac_status
= AC_STATUS_FOUND
;
3165 /* we don't correct pa_pstart or pa_plen here to avoid
3166 * possible race when the group is being loaded concurrently
3167 * instead we correct pa later, after blocks are marked
3168 * in on-disk bitmap -- see ext4_mb_release_context()
3169 * Other CPUs are prevented from allocating from this pa by lg_mutex
3171 mb_debug(1, "use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3175 * Return the prealloc space that have minimal distance
3176 * from the goal block. @cpa is the prealloc
3177 * space that is having currently known minimal distance
3178 * from the goal block.
3180 static struct ext4_prealloc_space
*
3181 ext4_mb_check_group_pa(ext4_fsblk_t goal_block
,
3182 struct ext4_prealloc_space
*pa
,
3183 struct ext4_prealloc_space
*cpa
)
3185 ext4_fsblk_t cur_distance
, new_distance
;
3188 atomic_inc(&pa
->pa_count
);
3191 cur_distance
= abs(goal_block
- cpa
->pa_pstart
);
3192 new_distance
= abs(goal_block
- pa
->pa_pstart
);
3194 if (cur_distance
< new_distance
)
3197 /* drop the previous reference */
3198 atomic_dec(&cpa
->pa_count
);
3199 atomic_inc(&pa
->pa_count
);
3204 * search goal blocks in preallocated space
3206 static noinline_for_stack
int
3207 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3210 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3211 struct ext4_locality_group
*lg
;
3212 struct ext4_prealloc_space
*pa
, *cpa
= NULL
;
3213 ext4_fsblk_t goal_block
;
3215 /* only data can be preallocated */
3216 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3219 /* first, try per-file preallocation */
3221 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3223 /* all fields in this condition don't change,
3224 * so we can skip locking for them */
3225 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3226 ac
->ac_o_ex
.fe_logical
>= pa
->pa_lstart
+ pa
->pa_len
)
3229 /* non-extent files can't have physical blocks past 2^32 */
3230 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)) &&
3231 pa
->pa_pstart
+ pa
->pa_len
> EXT4_MAX_BLOCK_FILE_PHYS
)
3234 /* found preallocated blocks, use them */
3235 spin_lock(&pa
->pa_lock
);
3236 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3237 atomic_inc(&pa
->pa_count
);
3238 ext4_mb_use_inode_pa(ac
, pa
);
3239 spin_unlock(&pa
->pa_lock
);
3240 ac
->ac_criteria
= 10;
3244 spin_unlock(&pa
->pa_lock
);
3248 /* can we use group allocation? */
3249 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3252 /* inode may have no locality group for some reason */
3256 order
= fls(ac
->ac_o_ex
.fe_len
) - 1;
3257 if (order
> PREALLOC_TB_SIZE
- 1)
3258 /* The max size of hash table is PREALLOC_TB_SIZE */
3259 order
= PREALLOC_TB_SIZE
- 1;
3261 goal_block
= ext4_grp_offs_to_block(ac
->ac_sb
, &ac
->ac_g_ex
);
3263 * search for the prealloc space that is having
3264 * minimal distance from the goal block.
3266 for (i
= order
; i
< PREALLOC_TB_SIZE
; i
++) {
3268 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[i
],
3270 spin_lock(&pa
->pa_lock
);
3271 if (pa
->pa_deleted
== 0 &&
3272 pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3274 cpa
= ext4_mb_check_group_pa(goal_block
,
3277 spin_unlock(&pa
->pa_lock
);
3282 ext4_mb_use_group_pa(ac
, cpa
);
3283 ac
->ac_criteria
= 20;
3290 * the function goes through all block freed in the group
3291 * but not yet committed and marks them used in in-core bitmap.
3292 * buddy must be generated from this bitmap
3293 * Need to be called with the ext4 group lock held
3295 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
3299 struct ext4_group_info
*grp
;
3300 struct ext4_free_data
*entry
;
3302 grp
= ext4_get_group_info(sb
, group
);
3303 n
= rb_first(&(grp
->bb_free_root
));
3306 entry
= rb_entry(n
, struct ext4_free_data
, node
);
3307 mb_set_bits(bitmap
, entry
->start_blk
, entry
->count
);
3314 * the function goes through all preallocation in this group and marks them
3315 * used in in-core bitmap. buddy must be generated from this bitmap
3316 * Need to be called with ext4 group lock held
3318 static noinline_for_stack
3319 void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3322 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3323 struct ext4_prealloc_space
*pa
;
3324 struct list_head
*cur
;
3325 ext4_group_t groupnr
;
3326 ext4_grpblk_t start
;
3327 int preallocated
= 0;
3331 /* all form of preallocation discards first load group,
3332 * so the only competing code is preallocation use.
3333 * we don't need any locking here
3334 * notice we do NOT ignore preallocations with pa_deleted
3335 * otherwise we could leave used blocks available for
3336 * allocation in buddy when concurrent ext4_mb_put_pa()
3337 * is dropping preallocation
3339 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3340 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3341 spin_lock(&pa
->pa_lock
);
3342 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3345 spin_unlock(&pa
->pa_lock
);
3346 if (unlikely(len
== 0))
3348 BUG_ON(groupnr
!= group
);
3349 mb_set_bits(bitmap
, start
, len
);
3350 preallocated
+= len
;
3353 mb_debug(1, "prellocated %u for group %u\n", preallocated
, group
);
3356 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3358 struct ext4_prealloc_space
*pa
;
3359 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3360 kmem_cache_free(ext4_pspace_cachep
, pa
);
3364 * drops a reference to preallocated space descriptor
3365 * if this was the last reference and the space is consumed
3367 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3368 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3371 ext4_fsblk_t grp_blk
;
3373 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0)
3376 /* in this short window concurrent discard can set pa_deleted */
3377 spin_lock(&pa
->pa_lock
);
3378 if (pa
->pa_deleted
== 1) {
3379 spin_unlock(&pa
->pa_lock
);
3384 spin_unlock(&pa
->pa_lock
);
3386 grp_blk
= pa
->pa_pstart
;
3388 * If doing group-based preallocation, pa_pstart may be in the
3389 * next group when pa is used up
3391 if (pa
->pa_type
== MB_GROUP_PA
)
3394 ext4_get_group_no_and_offset(sb
, grp_blk
, &grp
, NULL
);
3399 * P1 (buddy init) P2 (regular allocation)
3400 * find block B in PA
3401 * copy on-disk bitmap to buddy
3402 * mark B in on-disk bitmap
3403 * drop PA from group
3404 * mark all PAs in buddy
3406 * thus, P1 initializes buddy with B available. to prevent this
3407 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3410 ext4_lock_group(sb
, grp
);
3411 list_del(&pa
->pa_group_list
);
3412 ext4_unlock_group(sb
, grp
);
3414 spin_lock(pa
->pa_obj_lock
);
3415 list_del_rcu(&pa
->pa_inode_list
);
3416 spin_unlock(pa
->pa_obj_lock
);
3418 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3422 * creates new preallocated space for given inode
3424 static noinline_for_stack
int
3425 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3427 struct super_block
*sb
= ac
->ac_sb
;
3428 struct ext4_prealloc_space
*pa
;
3429 struct ext4_group_info
*grp
;
3430 struct ext4_inode_info
*ei
;
3432 /* preallocate only when found space is larger then requested */
3433 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3434 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3435 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3437 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3441 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3447 /* we can't allocate as much as normalizer wants.
3448 * so, found space must get proper lstart
3449 * to cover original request */
3450 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3451 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3453 /* we're limited by original request in that
3454 * logical block must be covered any way
3455 * winl is window we can move our chunk within */
3456 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3458 /* also, we should cover whole original request */
3459 wins
= ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
;
3461 /* the smallest one defines real window */
3462 win
= min(winl
, wins
);
3464 offs
= ac
->ac_o_ex
.fe_logical
% ac
->ac_b_ex
.fe_len
;
3465 if (offs
&& offs
< win
)
3468 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
- win
;
3469 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3470 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3473 /* preallocation can change ac_b_ex, thus we store actually
3474 * allocated blocks for history */
3475 ac
->ac_f_ex
= ac
->ac_b_ex
;
3477 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3478 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3479 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3480 pa
->pa_free
= pa
->pa_len
;
3481 atomic_set(&pa
->pa_count
, 1);
3482 spin_lock_init(&pa
->pa_lock
);
3483 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3484 INIT_LIST_HEAD(&pa
->pa_group_list
);
3486 pa
->pa_type
= MB_INODE_PA
;
3488 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa
,
3489 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3490 trace_ext4_mb_new_inode_pa(ac
, pa
);
3492 ext4_mb_use_inode_pa(ac
, pa
);
3493 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3495 ei
= EXT4_I(ac
->ac_inode
);
3496 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3498 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3499 pa
->pa_inode
= ac
->ac_inode
;
3501 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3502 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3503 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3505 spin_lock(pa
->pa_obj_lock
);
3506 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3507 spin_unlock(pa
->pa_obj_lock
);
3513 * creates new preallocated space for locality group inodes belongs to
3515 static noinline_for_stack
int
3516 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3518 struct super_block
*sb
= ac
->ac_sb
;
3519 struct ext4_locality_group
*lg
;
3520 struct ext4_prealloc_space
*pa
;
3521 struct ext4_group_info
*grp
;
3523 /* preallocate only when found space is larger then requested */
3524 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3525 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3526 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3528 BUG_ON(ext4_pspace_cachep
== NULL
);
3529 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3533 /* preallocation can change ac_b_ex, thus we store actually
3534 * allocated blocks for history */
3535 ac
->ac_f_ex
= ac
->ac_b_ex
;
3537 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3538 pa
->pa_lstart
= pa
->pa_pstart
;
3539 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3540 pa
->pa_free
= pa
->pa_len
;
3541 atomic_set(&pa
->pa_count
, 1);
3542 spin_lock_init(&pa
->pa_lock
);
3543 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3544 INIT_LIST_HEAD(&pa
->pa_group_list
);
3546 pa
->pa_type
= MB_GROUP_PA
;
3548 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa
,
3549 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3550 trace_ext4_mb_new_group_pa(ac
, pa
);
3552 ext4_mb_use_group_pa(ac
, pa
);
3553 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3555 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3559 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3560 pa
->pa_inode
= NULL
;
3562 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3563 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3564 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3567 * We will later add the new pa to the right bucket
3568 * after updating the pa_free in ext4_mb_release_context
3573 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3577 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3578 err
= ext4_mb_new_group_pa(ac
);
3580 err
= ext4_mb_new_inode_pa(ac
);
3585 * finds all unused blocks in on-disk bitmap, frees them in
3586 * in-core bitmap and buddy.
3587 * @pa must be unlinked from inode and group lists, so that
3588 * nobody else can find/use it.
3589 * the caller MUST hold group/inode locks.
3590 * TODO: optimize the case when there are no in-core structures yet
3592 static noinline_for_stack
int
3593 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3594 struct ext4_prealloc_space
*pa
,
3595 struct ext4_allocation_context
*ac
)
3597 struct super_block
*sb
= e4b
->bd_sb
;
3598 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3603 unsigned long long grp_blk_start
;
3607 BUG_ON(pa
->pa_deleted
== 0);
3608 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3609 grp_blk_start
= pa
->pa_pstart
- bit
;
3610 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3611 end
= bit
+ pa
->pa_len
;
3615 ac
->ac_inode
= pa
->pa_inode
;
3619 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3622 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3623 mb_debug(1, " free preallocated %u/%u in group %u\n",
3624 (unsigned) ext4_group_first_block_no(sb
, group
) + bit
,
3625 (unsigned) next
- bit
, (unsigned) group
);
3629 ac
->ac_b_ex
.fe_group
= group
;
3630 ac
->ac_b_ex
.fe_start
= bit
;
3631 ac
->ac_b_ex
.fe_len
= next
- bit
;
3632 ac
->ac_b_ex
.fe_logical
= 0;
3633 trace_ext4_mballoc_discard(ac
);
3636 trace_ext4_mb_release_inode_pa(sb
, ac
, pa
, grp_blk_start
+ bit
,
3638 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3641 if (free
!= pa
->pa_free
) {
3642 printk(KERN_CRIT
"pa %p: logic %lu, phys. %lu, len %lu\n",
3643 pa
, (unsigned long) pa
->pa_lstart
,
3644 (unsigned long) pa
->pa_pstart
,
3645 (unsigned long) pa
->pa_len
);
3646 ext4_grp_locked_error(sb
, group
, 0, 0, "free %u, pa_free %u",
3649 * pa is already deleted so we use the value obtained
3650 * from the bitmap and continue.
3653 atomic_add(free
, &sbi
->s_mb_discarded
);
3658 static noinline_for_stack
int
3659 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3660 struct ext4_prealloc_space
*pa
,
3661 struct ext4_allocation_context
*ac
)
3663 struct super_block
*sb
= e4b
->bd_sb
;
3667 trace_ext4_mb_release_group_pa(sb
, ac
, pa
);
3668 BUG_ON(pa
->pa_deleted
== 0);
3669 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3670 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3671 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3672 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3676 ac
->ac_inode
= NULL
;
3677 ac
->ac_b_ex
.fe_group
= group
;
3678 ac
->ac_b_ex
.fe_start
= bit
;
3679 ac
->ac_b_ex
.fe_len
= pa
->pa_len
;
3680 ac
->ac_b_ex
.fe_logical
= 0;
3681 trace_ext4_mballoc_discard(ac
);
3688 * releases all preallocations in given group
3690 * first, we need to decide discard policy:
3691 * - when do we discard
3693 * - how many do we discard
3694 * 1) how many requested
3696 static noinline_for_stack
int
3697 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3698 ext4_group_t group
, int needed
)
3700 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3701 struct buffer_head
*bitmap_bh
= NULL
;
3702 struct ext4_prealloc_space
*pa
, *tmp
;
3703 struct ext4_allocation_context
*ac
;
3704 struct list_head list
;
3705 struct ext4_buddy e4b
;
3710 mb_debug(1, "discard preallocation for group %u\n", group
);
3712 if (list_empty(&grp
->bb_prealloc_list
))
3715 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3716 if (bitmap_bh
== NULL
) {
3717 ext4_error(sb
, "Error reading block bitmap for %u", group
);
3721 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3723 ext4_error(sb
, "Error loading buddy information for %u", group
);
3729 needed
= EXT4_BLOCKS_PER_GROUP(sb
) + 1;
3731 INIT_LIST_HEAD(&list
);
3732 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3736 ext4_lock_group(sb
, group
);
3737 list_for_each_entry_safe(pa
, tmp
,
3738 &grp
->bb_prealloc_list
, pa_group_list
) {
3739 spin_lock(&pa
->pa_lock
);
3740 if (atomic_read(&pa
->pa_count
)) {
3741 spin_unlock(&pa
->pa_lock
);
3745 if (pa
->pa_deleted
) {
3746 spin_unlock(&pa
->pa_lock
);
3750 /* seems this one can be freed ... */
3753 /* we can trust pa_free ... */
3754 free
+= pa
->pa_free
;
3756 spin_unlock(&pa
->pa_lock
);
3758 list_del(&pa
->pa_group_list
);
3759 list_add(&pa
->u
.pa_tmp_list
, &list
);
3762 /* if we still need more blocks and some PAs were used, try again */
3763 if (free
< needed
&& busy
) {
3765 ext4_unlock_group(sb
, group
);
3767 * Yield the CPU here so that we don't get soft lockup
3768 * in non preempt case.
3774 /* found anything to free? */
3775 if (list_empty(&list
)) {
3780 /* now free all selected PAs */
3781 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3783 /* remove from object (inode or locality group) */
3784 spin_lock(pa
->pa_obj_lock
);
3785 list_del_rcu(&pa
->pa_inode_list
);
3786 spin_unlock(pa
->pa_obj_lock
);
3788 if (pa
->pa_type
== MB_GROUP_PA
)
3789 ext4_mb_release_group_pa(&e4b
, pa
, ac
);
3791 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3793 list_del(&pa
->u
.pa_tmp_list
);
3794 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3798 ext4_unlock_group(sb
, group
);
3800 kmem_cache_free(ext4_ac_cachep
, ac
);
3801 ext4_mb_unload_buddy(&e4b
);
3807 * releases all non-used preallocated blocks for given inode
3809 * It's important to discard preallocations under i_data_sem
3810 * We don't want another block to be served from the prealloc
3811 * space when we are discarding the inode prealloc space.
3813 * FIXME!! Make sure it is valid at all the call sites
3815 void ext4_discard_preallocations(struct inode
*inode
)
3817 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3818 struct super_block
*sb
= inode
->i_sb
;
3819 struct buffer_head
*bitmap_bh
= NULL
;
3820 struct ext4_prealloc_space
*pa
, *tmp
;
3821 struct ext4_allocation_context
*ac
;
3822 ext4_group_t group
= 0;
3823 struct list_head list
;
3824 struct ext4_buddy e4b
;
3827 if (!S_ISREG(inode
->i_mode
)) {
3828 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3832 mb_debug(1, "discard preallocation for inode %lu\n", inode
->i_ino
);
3833 trace_ext4_discard_preallocations(inode
);
3835 INIT_LIST_HEAD(&list
);
3837 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
3840 ac
->ac_inode
= inode
;
3843 /* first, collect all pa's in the inode */
3844 spin_lock(&ei
->i_prealloc_lock
);
3845 while (!list_empty(&ei
->i_prealloc_list
)) {
3846 pa
= list_entry(ei
->i_prealloc_list
.next
,
3847 struct ext4_prealloc_space
, pa_inode_list
);
3848 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3849 spin_lock(&pa
->pa_lock
);
3850 if (atomic_read(&pa
->pa_count
)) {
3851 /* this shouldn't happen often - nobody should
3852 * use preallocation while we're discarding it */
3853 spin_unlock(&pa
->pa_lock
);
3854 spin_unlock(&ei
->i_prealloc_lock
);
3855 printk(KERN_ERR
"uh-oh! used pa while discarding\n");
3857 schedule_timeout_uninterruptible(HZ
);
3861 if (pa
->pa_deleted
== 0) {
3863 spin_unlock(&pa
->pa_lock
);
3864 list_del_rcu(&pa
->pa_inode_list
);
3865 list_add(&pa
->u
.pa_tmp_list
, &list
);
3869 /* someone is deleting pa right now */
3870 spin_unlock(&pa
->pa_lock
);
3871 spin_unlock(&ei
->i_prealloc_lock
);
3873 /* we have to wait here because pa_deleted
3874 * doesn't mean pa is already unlinked from
3875 * the list. as we might be called from
3876 * ->clear_inode() the inode will get freed
3877 * and concurrent thread which is unlinking
3878 * pa from inode's list may access already
3879 * freed memory, bad-bad-bad */
3881 /* XXX: if this happens too often, we can
3882 * add a flag to force wait only in case
3883 * of ->clear_inode(), but not in case of
3884 * regular truncate */
3885 schedule_timeout_uninterruptible(HZ
);
3888 spin_unlock(&ei
->i_prealloc_lock
);
3890 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3891 BUG_ON(pa
->pa_type
!= MB_INODE_PA
);
3892 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
3894 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3896 ext4_error(sb
, "Error loading buddy information for %u",
3901 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3902 if (bitmap_bh
== NULL
) {
3903 ext4_error(sb
, "Error reading block bitmap for %u",
3905 ext4_mb_unload_buddy(&e4b
);
3909 ext4_lock_group(sb
, group
);
3910 list_del(&pa
->pa_group_list
);
3911 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
, ac
);
3912 ext4_unlock_group(sb
, group
);
3914 ext4_mb_unload_buddy(&e4b
);
3917 list_del(&pa
->u
.pa_tmp_list
);
3918 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3921 kmem_cache_free(ext4_ac_cachep
, ac
);
3925 * finds all preallocated spaces and return blocks being freed to them
3926 * if preallocated space becomes full (no block is used from the space)
3927 * then the function frees space in buddy
3928 * XXX: at the moment, truncate (which is the only way to free blocks)
3929 * discards all preallocations
3931 static void ext4_mb_return_to_preallocation(struct inode
*inode
,
3932 struct ext4_buddy
*e4b
,
3933 sector_t block
, int count
)
3935 BUG_ON(!list_empty(&EXT4_I(inode
)->i_prealloc_list
));
3937 #ifdef CONFIG_EXT4_DEBUG
3938 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3940 struct super_block
*sb
= ac
->ac_sb
;
3941 ext4_group_t ngroups
, i
;
3943 if (EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
)
3946 printk(KERN_ERR
"EXT4-fs: Can't allocate:"
3947 " Allocation context details:\n");
3948 printk(KERN_ERR
"EXT4-fs: status %d flags %d\n",
3949 ac
->ac_status
, ac
->ac_flags
);
3950 printk(KERN_ERR
"EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
3951 "best %lu/%lu/%lu@%lu cr %d\n",
3952 (unsigned long)ac
->ac_o_ex
.fe_group
,
3953 (unsigned long)ac
->ac_o_ex
.fe_start
,
3954 (unsigned long)ac
->ac_o_ex
.fe_len
,
3955 (unsigned long)ac
->ac_o_ex
.fe_logical
,
3956 (unsigned long)ac
->ac_g_ex
.fe_group
,
3957 (unsigned long)ac
->ac_g_ex
.fe_start
,
3958 (unsigned long)ac
->ac_g_ex
.fe_len
,
3959 (unsigned long)ac
->ac_g_ex
.fe_logical
,
3960 (unsigned long)ac
->ac_b_ex
.fe_group
,
3961 (unsigned long)ac
->ac_b_ex
.fe_start
,
3962 (unsigned long)ac
->ac_b_ex
.fe_len
,
3963 (unsigned long)ac
->ac_b_ex
.fe_logical
,
3964 (int)ac
->ac_criteria
);
3965 printk(KERN_ERR
"EXT4-fs: %lu scanned, %d found\n", ac
->ac_ex_scanned
,
3967 printk(KERN_ERR
"EXT4-fs: groups: \n");
3968 ngroups
= ext4_get_groups_count(sb
);
3969 for (i
= 0; i
< ngroups
; i
++) {
3970 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
3971 struct ext4_prealloc_space
*pa
;
3972 ext4_grpblk_t start
;
3973 struct list_head
*cur
;
3974 ext4_lock_group(sb
, i
);
3975 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3976 pa
= list_entry(cur
, struct ext4_prealloc_space
,
3978 spin_lock(&pa
->pa_lock
);
3979 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3981 spin_unlock(&pa
->pa_lock
);
3982 printk(KERN_ERR
"PA:%u:%d:%u \n", i
,
3985 ext4_unlock_group(sb
, i
);
3987 if (grp
->bb_free
== 0)
3989 printk(KERN_ERR
"%u: %d/%d \n",
3990 i
, grp
->bb_free
, grp
->bb_fragments
);
3992 printk(KERN_ERR
"\n");
3995 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4002 * We use locality group preallocation for small size file. The size of the
4003 * file is determined by the current size or the resulting size after
4004 * allocation which ever is larger
4006 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4008 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
4010 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4011 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
4014 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
4017 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
4020 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
4021 isize
= (i_size_read(ac
->ac_inode
) + ac
->ac_sb
->s_blocksize
- 1)
4024 if ((size
== isize
) &&
4025 !ext4_fs_is_busy(sbi
) &&
4026 (atomic_read(&ac
->ac_inode
->i_writecount
) == 0)) {
4027 ac
->ac_flags
|= EXT4_MB_HINT_NOPREALLOC
;
4031 /* don't use group allocation for large files */
4032 size
= max(size
, isize
);
4033 if (size
> sbi
->s_mb_stream_request
) {
4034 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4038 BUG_ON(ac
->ac_lg
!= NULL
);
4040 * locality group prealloc space are per cpu. The reason for having
4041 * per cpu locality group is to reduce the contention between block
4042 * request from multiple CPUs.
4044 ac
->ac_lg
= __this_cpu_ptr(sbi
->s_locality_groups
);
4046 /* we're going to use group allocation */
4047 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
4049 /* serialize all allocations in the group */
4050 mutex_lock(&ac
->ac_lg
->lg_mutex
);
4053 static noinline_for_stack
int
4054 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
4055 struct ext4_allocation_request
*ar
)
4057 struct super_block
*sb
= ar
->inode
->i_sb
;
4058 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4059 struct ext4_super_block
*es
= sbi
->s_es
;
4063 ext4_grpblk_t block
;
4065 /* we can't allocate > group size */
4068 /* just a dirty hack to filter too big requests */
4069 if (len
>= EXT4_BLOCKS_PER_GROUP(sb
) - 10)
4070 len
= EXT4_BLOCKS_PER_GROUP(sb
) - 10;
4072 /* start searching from the goal */
4074 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
4075 goal
>= ext4_blocks_count(es
))
4076 goal
= le32_to_cpu(es
->s_first_data_block
);
4077 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
4079 /* set up allocation goals */
4080 memset(ac
, 0, sizeof(struct ext4_allocation_context
));
4081 ac
->ac_b_ex
.fe_logical
= ar
->logical
;
4082 ac
->ac_status
= AC_STATUS_CONTINUE
;
4084 ac
->ac_inode
= ar
->inode
;
4085 ac
->ac_o_ex
.fe_logical
= ar
->logical
;
4086 ac
->ac_o_ex
.fe_group
= group
;
4087 ac
->ac_o_ex
.fe_start
= block
;
4088 ac
->ac_o_ex
.fe_len
= len
;
4089 ac
->ac_g_ex
.fe_logical
= ar
->logical
;
4090 ac
->ac_g_ex
.fe_group
= group
;
4091 ac
->ac_g_ex
.fe_start
= block
;
4092 ac
->ac_g_ex
.fe_len
= len
;
4093 ac
->ac_flags
= ar
->flags
;
4095 /* we have to define context: we'll we work with a file or
4096 * locality group. this is a policy, actually */
4097 ext4_mb_group_or_file(ac
);
4099 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4100 "left: %u/%u, right %u/%u to %swritable\n",
4101 (unsigned) ar
->len
, (unsigned) ar
->logical
,
4102 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
4103 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
4104 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
4105 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
4110 static noinline_for_stack
void
4111 ext4_mb_discard_lg_preallocations(struct super_block
*sb
,
4112 struct ext4_locality_group
*lg
,
4113 int order
, int total_entries
)
4115 ext4_group_t group
= 0;
4116 struct ext4_buddy e4b
;
4117 struct list_head discard_list
;
4118 struct ext4_prealloc_space
*pa
, *tmp
;
4119 struct ext4_allocation_context
*ac
;
4121 mb_debug(1, "discard locality group preallocation\n");
4123 INIT_LIST_HEAD(&discard_list
);
4124 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4128 spin_lock(&lg
->lg_prealloc_lock
);
4129 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[order
],
4131 spin_lock(&pa
->pa_lock
);
4132 if (atomic_read(&pa
->pa_count
)) {
4134 * This is the pa that we just used
4135 * for block allocation. So don't
4138 spin_unlock(&pa
->pa_lock
);
4141 if (pa
->pa_deleted
) {
4142 spin_unlock(&pa
->pa_lock
);
4145 /* only lg prealloc space */
4146 BUG_ON(pa
->pa_type
!= MB_GROUP_PA
);
4148 /* seems this one can be freed ... */
4150 spin_unlock(&pa
->pa_lock
);
4152 list_del_rcu(&pa
->pa_inode_list
);
4153 list_add(&pa
->u
.pa_tmp_list
, &discard_list
);
4156 if (total_entries
<= 5) {
4158 * we want to keep only 5 entries
4159 * allowing it to grow to 8. This
4160 * mak sure we don't call discard
4161 * soon for this list.
4166 spin_unlock(&lg
->lg_prealloc_lock
);
4168 list_for_each_entry_safe(pa
, tmp
, &discard_list
, u
.pa_tmp_list
) {
4170 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
4171 if (ext4_mb_load_buddy(sb
, group
, &e4b
)) {
4172 ext4_error(sb
, "Error loading buddy information for %u",
4176 ext4_lock_group(sb
, group
);
4177 list_del(&pa
->pa_group_list
);
4178 ext4_mb_release_group_pa(&e4b
, pa
, ac
);
4179 ext4_unlock_group(sb
, group
);
4181 ext4_mb_unload_buddy(&e4b
);
4182 list_del(&pa
->u
.pa_tmp_list
);
4183 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4186 kmem_cache_free(ext4_ac_cachep
, ac
);
4190 * We have incremented pa_count. So it cannot be freed at this
4191 * point. Also we hold lg_mutex. So no parallel allocation is
4192 * possible from this lg. That means pa_free cannot be updated.
4194 * A parallel ext4_mb_discard_group_preallocations is possible.
4195 * which can cause the lg_prealloc_list to be updated.
4198 static void ext4_mb_add_n_trim(struct ext4_allocation_context
*ac
)
4200 int order
, added
= 0, lg_prealloc_count
= 1;
4201 struct super_block
*sb
= ac
->ac_sb
;
4202 struct ext4_locality_group
*lg
= ac
->ac_lg
;
4203 struct ext4_prealloc_space
*tmp_pa
, *pa
= ac
->ac_pa
;
4205 order
= fls(pa
->pa_free
) - 1;
4206 if (order
> PREALLOC_TB_SIZE
- 1)
4207 /* The max size of hash table is PREALLOC_TB_SIZE */
4208 order
= PREALLOC_TB_SIZE
- 1;
4209 /* Add the prealloc space to lg */
4211 list_for_each_entry_rcu(tmp_pa
, &lg
->lg_prealloc_list
[order
],
4213 spin_lock(&tmp_pa
->pa_lock
);
4214 if (tmp_pa
->pa_deleted
) {
4215 spin_unlock(&tmp_pa
->pa_lock
);
4218 if (!added
&& pa
->pa_free
< tmp_pa
->pa_free
) {
4219 /* Add to the tail of the previous entry */
4220 list_add_tail_rcu(&pa
->pa_inode_list
,
4221 &tmp_pa
->pa_inode_list
);
4224 * we want to count the total
4225 * number of entries in the list
4228 spin_unlock(&tmp_pa
->pa_lock
);
4229 lg_prealloc_count
++;
4232 list_add_tail_rcu(&pa
->pa_inode_list
,
4233 &lg
->lg_prealloc_list
[order
]);
4236 /* Now trim the list to be not more than 8 elements */
4237 if (lg_prealloc_count
> 8) {
4238 ext4_mb_discard_lg_preallocations(sb
, lg
,
4239 order
, lg_prealloc_count
);
4246 * release all resource we used in allocation
4248 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
4250 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
4252 if (pa
->pa_type
== MB_GROUP_PA
) {
4253 /* see comment in ext4_mb_use_group_pa() */
4254 spin_lock(&pa
->pa_lock
);
4255 pa
->pa_pstart
+= ac
->ac_b_ex
.fe_len
;
4256 pa
->pa_lstart
+= ac
->ac_b_ex
.fe_len
;
4257 pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
4258 pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
4259 spin_unlock(&pa
->pa_lock
);
4263 up_read(ac
->alloc_semp
);
4266 * We want to add the pa to the right bucket.
4267 * Remove it from the list and while adding
4268 * make sure the list to which we are adding
4269 * doesn't grow big. We need to release
4270 * alloc_semp before calling ext4_mb_add_n_trim()
4272 if ((pa
->pa_type
== MB_GROUP_PA
) && likely(pa
->pa_free
)) {
4273 spin_lock(pa
->pa_obj_lock
);
4274 list_del_rcu(&pa
->pa_inode_list
);
4275 spin_unlock(pa
->pa_obj_lock
);
4276 ext4_mb_add_n_trim(ac
);
4278 ext4_mb_put_pa(ac
, ac
->ac_sb
, pa
);
4280 if (ac
->ac_bitmap_page
)
4281 page_cache_release(ac
->ac_bitmap_page
);
4282 if (ac
->ac_buddy_page
)
4283 page_cache_release(ac
->ac_buddy_page
);
4284 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
4285 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
4286 ext4_mb_collect_stats(ac
);
4290 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
4292 ext4_group_t i
, ngroups
= ext4_get_groups_count(sb
);
4296 trace_ext4_mb_discard_preallocations(sb
, needed
);
4297 for (i
= 0; i
< ngroups
&& needed
> 0; i
++) {
4298 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4307 * Main entry point into mballoc to allocate blocks
4308 * it tries to use preallocation first, then falls back
4309 * to usual allocation
4311 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4312 struct ext4_allocation_request
*ar
, int *errp
)
4315 struct ext4_allocation_context
*ac
= NULL
;
4316 struct ext4_sb_info
*sbi
;
4317 struct super_block
*sb
;
4318 ext4_fsblk_t block
= 0;
4319 unsigned int inquota
= 0;
4320 unsigned int reserv_blks
= 0;
4322 sb
= ar
->inode
->i_sb
;
4325 trace_ext4_request_blocks(ar
);
4328 * For delayed allocation, we could skip the ENOSPC and
4329 * EDQUOT check, as blocks and quotas have been already
4330 * reserved when data being copied into pagecache.
4332 if (EXT4_I(ar
->inode
)->i_delalloc_reserved_flag
)
4333 ar
->flags
|= EXT4_MB_DELALLOC_RESERVED
;
4335 /* Without delayed allocation we need to verify
4336 * there is enough free blocks to do block allocation
4337 * and verify allocation doesn't exceed the quota limits.
4339 while (ar
->len
&& ext4_claim_free_blocks(sbi
, ar
->len
)) {
4340 /* let others to free the space */
4342 ar
->len
= ar
->len
>> 1;
4348 reserv_blks
= ar
->len
;
4349 while (ar
->len
&& dquot_alloc_block(ar
->inode
, ar
->len
)) {
4350 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4360 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4367 *errp
= ext4_mb_initialize_context(ac
, ar
);
4373 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4374 if (!ext4_mb_use_preallocated(ac
)) {
4375 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4376 ext4_mb_normalize_request(ac
, ar
);
4378 /* allocate space in core */
4379 *errp
= ext4_mb_regular_allocator(ac
);
4383 /* as we've just preallocated more space than
4384 * user requested orinally, we store allocated
4385 * space in a special descriptor */
4386 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4387 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4388 ext4_mb_new_preallocation(ac
);
4390 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4391 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
, reserv_blks
);
4392 if (*errp
== -EAGAIN
) {
4394 * drop the reference that we took
4395 * in ext4_mb_use_best_found
4397 ext4_mb_release_context(ac
);
4398 ac
->ac_b_ex
.fe_group
= 0;
4399 ac
->ac_b_ex
.fe_start
= 0;
4400 ac
->ac_b_ex
.fe_len
= 0;
4401 ac
->ac_status
= AC_STATUS_CONTINUE
;
4405 ext4_discard_allocated_blocks(ac
);
4407 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4408 ar
->len
= ac
->ac_b_ex
.fe_len
;
4411 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4418 ac
->ac_b_ex
.fe_len
= 0;
4420 ext4_mb_show_ac(ac
);
4422 ext4_mb_release_context(ac
);
4425 kmem_cache_free(ext4_ac_cachep
, ac
);
4426 if (inquota
&& ar
->len
< inquota
)
4427 dquot_free_block(ar
->inode
, inquota
- ar
->len
);
4429 if (!EXT4_I(ar
->inode
)->i_delalloc_reserved_flag
)
4430 /* release all the reserved blocks if non delalloc */
4431 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
4435 trace_ext4_allocate_blocks(ar
, (unsigned long long)block
);
4441 * We can merge two free data extents only if the physical blocks
4442 * are contiguous, AND the extents were freed by the same transaction,
4443 * AND the blocks are associated with the same group.
4445 static int can_merge(struct ext4_free_data
*entry1
,
4446 struct ext4_free_data
*entry2
)
4448 if ((entry1
->t_tid
== entry2
->t_tid
) &&
4449 (entry1
->group
== entry2
->group
) &&
4450 ((entry1
->start_blk
+ entry1
->count
) == entry2
->start_blk
))
4455 static noinline_for_stack
int
4456 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4457 struct ext4_free_data
*new_entry
)
4459 ext4_group_t group
= e4b
->bd_group
;
4460 ext4_grpblk_t block
;
4461 struct ext4_free_data
*entry
;
4462 struct ext4_group_info
*db
= e4b
->bd_info
;
4463 struct super_block
*sb
= e4b
->bd_sb
;
4464 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4465 struct rb_node
**n
= &db
->bb_free_root
.rb_node
, *node
;
4466 struct rb_node
*parent
= NULL
, *new_node
;
4468 BUG_ON(!ext4_handle_valid(handle
));
4469 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4470 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4472 new_node
= &new_entry
->node
;
4473 block
= new_entry
->start_blk
;
4476 /* first free block exent. We need to
4477 protect buddy cache from being freed,
4478 * otherwise we'll refresh it from
4479 * on-disk bitmap and lose not-yet-available
4481 page_cache_get(e4b
->bd_buddy_page
);
4482 page_cache_get(e4b
->bd_bitmap_page
);
4486 entry
= rb_entry(parent
, struct ext4_free_data
, node
);
4487 if (block
< entry
->start_blk
)
4489 else if (block
>= (entry
->start_blk
+ entry
->count
))
4490 n
= &(*n
)->rb_right
;
4492 ext4_grp_locked_error(sb
, group
, 0,
4493 ext4_group_first_block_no(sb
, group
) + block
,
4494 "Block already on to-be-freed list");
4499 rb_link_node(new_node
, parent
, n
);
4500 rb_insert_color(new_node
, &db
->bb_free_root
);
4502 /* Now try to see the extent can be merged to left and right */
4503 node
= rb_prev(new_node
);
4505 entry
= rb_entry(node
, struct ext4_free_data
, node
);
4506 if (can_merge(entry
, new_entry
)) {
4507 new_entry
->start_blk
= entry
->start_blk
;
4508 new_entry
->count
+= entry
->count
;
4509 rb_erase(node
, &(db
->bb_free_root
));
4510 spin_lock(&sbi
->s_md_lock
);
4511 list_del(&entry
->list
);
4512 spin_unlock(&sbi
->s_md_lock
);
4513 kmem_cache_free(ext4_free_ext_cachep
, entry
);
4517 node
= rb_next(new_node
);
4519 entry
= rb_entry(node
, struct ext4_free_data
, node
);
4520 if (can_merge(new_entry
, entry
)) {
4521 new_entry
->count
+= entry
->count
;
4522 rb_erase(node
, &(db
->bb_free_root
));
4523 spin_lock(&sbi
->s_md_lock
);
4524 list_del(&entry
->list
);
4525 spin_unlock(&sbi
->s_md_lock
);
4526 kmem_cache_free(ext4_free_ext_cachep
, entry
);
4529 /* Add the extent to transaction's private list */
4530 spin_lock(&sbi
->s_md_lock
);
4531 list_add(&new_entry
->list
, &handle
->h_transaction
->t_private_list
);
4532 spin_unlock(&sbi
->s_md_lock
);
4537 * ext4_free_blocks() -- Free given blocks and update quota
4538 * @handle: handle for this transaction
4540 * @block: start physical block to free
4541 * @count: number of blocks to count
4542 * @metadata: Are these metadata blocks
4544 void ext4_free_blocks(handle_t
*handle
, struct inode
*inode
,
4545 struct buffer_head
*bh
, ext4_fsblk_t block
,
4546 unsigned long count
, int flags
)
4548 struct buffer_head
*bitmap_bh
= NULL
;
4549 struct super_block
*sb
= inode
->i_sb
;
4550 struct ext4_allocation_context
*ac
= NULL
;
4551 struct ext4_group_desc
*gdp
;
4552 unsigned long freed
= 0;
4553 unsigned int overflow
;
4555 struct buffer_head
*gd_bh
;
4556 ext4_group_t block_group
;
4557 struct ext4_sb_info
*sbi
;
4558 struct ext4_buddy e4b
;
4564 BUG_ON(block
!= bh
->b_blocknr
);
4566 block
= bh
->b_blocknr
;
4570 if (!(flags
& EXT4_FREE_BLOCKS_VALIDATED
) &&
4571 !ext4_data_block_valid(sbi
, block
, count
)) {
4572 ext4_error(sb
, "Freeing blocks not in datazone - "
4573 "block = %llu, count = %lu", block
, count
);
4577 ext4_debug("freeing block %llu\n", block
);
4578 trace_ext4_free_blocks(inode
, block
, count
, flags
);
4580 if (flags
& EXT4_FREE_BLOCKS_FORGET
) {
4581 struct buffer_head
*tbh
= bh
;
4584 BUG_ON(bh
&& (count
> 1));
4586 for (i
= 0; i
< count
; i
++) {
4588 tbh
= sb_find_get_block(inode
->i_sb
,
4590 ext4_forget(handle
, flags
& EXT4_FREE_BLOCKS_METADATA
,
4591 inode
, tbh
, block
+ i
);
4596 * We need to make sure we don't reuse the freed block until
4597 * after the transaction is committed, which we can do by
4598 * treating the block as metadata, below. We make an
4599 * exception if the inode is to be written in writeback mode
4600 * since writeback mode has weak data consistency guarantees.
4602 if (!ext4_should_writeback_data(inode
))
4603 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4605 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4607 ac
->ac_inode
= inode
;
4613 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4616 * Check to see if we are freeing blocks across a group
4619 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4620 overflow
= bit
+ count
- EXT4_BLOCKS_PER_GROUP(sb
);
4623 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4628 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4634 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4635 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4636 in_range(block
, ext4_inode_table(sb
, gdp
),
4637 EXT4_SB(sb
)->s_itb_per_group
) ||
4638 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4639 EXT4_SB(sb
)->s_itb_per_group
)) {
4641 ext4_error(sb
, "Freeing blocks in system zone - "
4642 "Block = %llu, count = %lu", block
, count
);
4643 /* err = 0. ext4_std_error should be a no op */
4647 BUFFER_TRACE(bitmap_bh
, "getting write access");
4648 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4653 * We are about to modify some metadata. Call the journal APIs
4654 * to unshare ->b_data if a currently-committing transaction is
4657 BUFFER_TRACE(gd_bh
, "get_write_access");
4658 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4661 #ifdef AGGRESSIVE_CHECK
4664 for (i
= 0; i
< count
; i
++)
4665 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4669 ac
->ac_b_ex
.fe_group
= block_group
;
4670 ac
->ac_b_ex
.fe_start
= bit
;
4671 ac
->ac_b_ex
.fe_len
= count
;
4672 trace_ext4_mballoc_free(ac
);
4675 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4679 if ((flags
& EXT4_FREE_BLOCKS_METADATA
) && ext4_handle_valid(handle
)) {
4680 struct ext4_free_data
*new_entry
;
4682 * blocks being freed are metadata. these blocks shouldn't
4683 * be used until this transaction is committed
4685 new_entry
= kmem_cache_alloc(ext4_free_ext_cachep
, GFP_NOFS
);
4686 new_entry
->start_blk
= bit
;
4687 new_entry
->group
= block_group
;
4688 new_entry
->count
= count
;
4689 new_entry
->t_tid
= handle
->h_transaction
->t_tid
;
4691 ext4_lock_group(sb
, block_group
);
4692 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4693 ext4_mb_free_metadata(handle
, &e4b
, new_entry
);
4695 /* need to update group_info->bb_free and bitmap
4696 * with group lock held. generate_buddy look at
4697 * them with group lock_held
4699 if (test_opt(sb
, DISCARD
))
4700 ext4_issue_discard(sb
, block_group
, bit
, count
);
4701 ext4_lock_group(sb
, block_group
);
4702 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4703 mb_free_blocks(inode
, &e4b
, bit
, count
);
4704 ext4_mb_return_to_preallocation(inode
, &e4b
, block
, count
);
4707 ret
= ext4_free_blks_count(sb
, gdp
) + count
;
4708 ext4_free_blks_set(sb
, gdp
, ret
);
4709 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, block_group
, gdp
);
4710 ext4_unlock_group(sb
, block_group
);
4711 percpu_counter_add(&sbi
->s_freeblocks_counter
, count
);
4713 if (sbi
->s_log_groups_per_flex
) {
4714 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4715 atomic_add(count
, &sbi
->s_flex_groups
[flex_group
].free_blocks
);
4718 ext4_mb_unload_buddy(&e4b
);
4722 /* We dirtied the bitmap block */
4723 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4724 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4726 /* And the group descriptor block */
4727 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4728 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4732 if (overflow
&& !err
) {
4738 ext4_mark_super_dirty(sb
);
4741 dquot_free_block(inode
, freed
);
4743 ext4_std_error(sb
, err
);
4745 kmem_cache_free(ext4_ac_cachep
, ac
);