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 * lock the group_info alloc_sem of all the groups
951 * belonging to the same buddy cache page. This
952 * make sure other parallel operation on the buddy
953 * cache doesn't happen whild holding the buddy cache
956 static int ext4_mb_get_buddy_cache_lock(struct super_block
*sb
,
963 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
964 ext4_group_t first_group
;
965 struct ext4_group_info
*grp
;
967 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
969 * the buddy cache inode stores the block bitmap
970 * and buddy information in consecutive blocks.
971 * So for each group we need two blocks.
974 pnum
= block
/ blocks_per_page
;
975 first_group
= pnum
* blocks_per_page
/ 2;
977 groups_per_page
= blocks_per_page
>> 1;
978 if (groups_per_page
== 0)
980 /* read all groups the page covers into the cache */
981 for (i
= 0; i
< groups_per_page
; i
++) {
983 if ((first_group
+ i
) >= ngroups
)
985 grp
= ext4_get_group_info(sb
, first_group
+ i
);
986 /* take all groups write allocation
987 * semaphore. This make sure there is
988 * no block allocation going on in any
991 down_write_nested(&grp
->alloc_sem
, i
);
996 static void ext4_mb_put_buddy_cache_lock(struct super_block
*sb
,
997 ext4_group_t group
, int locked_group
)
1001 int blocks_per_page
;
1002 ext4_group_t first_group
;
1003 struct ext4_group_info
*grp
;
1005 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1007 * the buddy cache inode stores the block bitmap
1008 * and buddy information in consecutive blocks.
1009 * So for each group we need two blocks.
1012 pnum
= block
/ blocks_per_page
;
1013 first_group
= pnum
* blocks_per_page
/ 2;
1014 /* release locks on all the groups */
1015 for (i
= 0; i
< locked_group
; i
++) {
1017 grp
= ext4_get_group_info(sb
, first_group
+ i
);
1018 /* take all groups write allocation
1019 * semaphore. This make sure there is
1020 * no block allocation going on in any
1023 up_write(&grp
->alloc_sem
);
1029 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1030 * block group lock of all groups for this page; do not hold the BG lock when
1031 * calling this routine!
1033 static noinline_for_stack
1034 int ext4_mb_init_group(struct super_block
*sb
, ext4_group_t group
)
1039 int blocks_per_page
;
1040 int block
, pnum
, poff
;
1041 int num_grp_locked
= 0;
1042 struct ext4_group_info
*this_grp
;
1043 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1044 struct inode
*inode
= sbi
->s_buddy_cache
;
1045 struct page
*page
= NULL
, *bitmap_page
= NULL
;
1047 mb_debug(1, "init group %u\n", group
);
1048 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1049 this_grp
= ext4_get_group_info(sb
, group
);
1051 * This ensures that we don't reinit the buddy cache
1052 * page which map to the group from which we are already
1053 * allocating. If we are looking at the buddy cache we would
1054 * have taken a reference using ext4_mb_load_buddy and that
1055 * would have taken the alloc_sem lock.
1057 num_grp_locked
= ext4_mb_get_buddy_cache_lock(sb
, group
);
1058 if (!EXT4_MB_GRP_NEED_INIT(this_grp
)) {
1060 * somebody initialized the group
1061 * return without doing anything
1067 * the buddy cache inode stores the block bitmap
1068 * and buddy information in consecutive blocks.
1069 * So for each group we need two blocks.
1072 pnum
= block
/ blocks_per_page
;
1073 poff
= block
% blocks_per_page
;
1074 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1076 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1077 ret
= ext4_mb_init_cache(page
, NULL
);
1084 if (page
== NULL
|| !PageUptodate(page
)) {
1088 mark_page_accessed(page
);
1090 bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1092 /* init buddy cache */
1094 pnum
= block
/ blocks_per_page
;
1095 poff
= block
% blocks_per_page
;
1096 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1097 if (page
== bitmap_page
) {
1099 * If both the bitmap and buddy are in
1100 * the same page we don't need to force
1105 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1106 ret
= ext4_mb_init_cache(page
, bitmap
);
1113 if (page
== NULL
|| !PageUptodate(page
)) {
1117 mark_page_accessed(page
);
1119 ext4_mb_put_buddy_cache_lock(sb
, group
, num_grp_locked
);
1121 page_cache_release(bitmap_page
);
1123 page_cache_release(page
);
1128 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1129 * block group lock of all groups for this page; do not hold the BG lock when
1130 * calling this routine!
1132 static noinline_for_stack
int
1133 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
1134 struct ext4_buddy
*e4b
)
1136 int blocks_per_page
;
1142 struct ext4_group_info
*grp
;
1143 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1144 struct inode
*inode
= sbi
->s_buddy_cache
;
1146 mb_debug(1, "load group %u\n", group
);
1148 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1149 grp
= ext4_get_group_info(sb
, group
);
1151 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
1152 e4b
->bd_info
= ext4_get_group_info(sb
, group
);
1154 e4b
->bd_group
= group
;
1155 e4b
->bd_buddy_page
= NULL
;
1156 e4b
->bd_bitmap_page
= NULL
;
1157 e4b
->alloc_semp
= &grp
->alloc_sem
;
1159 /* Take the read lock on the group alloc
1160 * sem. This would make sure a parallel
1161 * ext4_mb_init_group happening on other
1162 * groups mapped by the page is blocked
1163 * till we are done with allocation
1166 down_read(e4b
->alloc_semp
);
1168 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1169 /* we need to check for group need init flag
1170 * with alloc_semp held so that we can be sure
1171 * that new blocks didn't get added to the group
1172 * when we are loading the buddy cache
1174 up_read(e4b
->alloc_semp
);
1176 * we need full data about the group
1177 * to make a good selection
1179 ret
= ext4_mb_init_group(sb
, group
);
1182 goto repeat_load_buddy
;
1186 * the buddy cache inode stores the block bitmap
1187 * and buddy information in consecutive blocks.
1188 * So for each group we need two blocks.
1191 pnum
= block
/ blocks_per_page
;
1192 poff
= block
% blocks_per_page
;
1194 /* we could use find_or_create_page(), but it locks page
1195 * what we'd like to avoid in fast path ... */
1196 page
= find_get_page(inode
->i_mapping
, pnum
);
1197 if (page
== NULL
|| !PageUptodate(page
)) {
1200 * drop the page reference and try
1201 * to get the page with lock. If we
1202 * are not uptodate that implies
1203 * somebody just created the page but
1204 * is yet to initialize the same. So
1205 * wait for it to initialize.
1207 page_cache_release(page
);
1208 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1210 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1211 if (!PageUptodate(page
)) {
1212 ret
= ext4_mb_init_cache(page
, NULL
);
1217 mb_cmp_bitmaps(e4b
, page_address(page
) +
1218 (poff
* sb
->s_blocksize
));
1223 if (page
== NULL
|| !PageUptodate(page
)) {
1227 e4b
->bd_bitmap_page
= page
;
1228 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1229 mark_page_accessed(page
);
1232 pnum
= block
/ blocks_per_page
;
1233 poff
= block
% blocks_per_page
;
1235 page
= find_get_page(inode
->i_mapping
, pnum
);
1236 if (page
== NULL
|| !PageUptodate(page
)) {
1238 page_cache_release(page
);
1239 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1241 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1242 if (!PageUptodate(page
)) {
1243 ret
= ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
1252 if (page
== NULL
|| !PageUptodate(page
)) {
1256 e4b
->bd_buddy_page
= page
;
1257 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
1258 mark_page_accessed(page
);
1260 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
1261 BUG_ON(e4b
->bd_buddy_page
== NULL
);
1266 if (e4b
->bd_bitmap_page
)
1267 page_cache_release(e4b
->bd_bitmap_page
);
1268 if (e4b
->bd_buddy_page
)
1269 page_cache_release(e4b
->bd_buddy_page
);
1270 e4b
->bd_buddy
= NULL
;
1271 e4b
->bd_bitmap
= NULL
;
1273 /* Done with the buddy cache */
1274 up_read(e4b
->alloc_semp
);
1278 static void ext4_mb_unload_buddy(struct ext4_buddy
*e4b
)
1280 if (e4b
->bd_bitmap_page
)
1281 page_cache_release(e4b
->bd_bitmap_page
);
1282 if (e4b
->bd_buddy_page
)
1283 page_cache_release(e4b
->bd_buddy_page
);
1284 /* Done with the buddy cache */
1285 if (e4b
->alloc_semp
)
1286 up_read(e4b
->alloc_semp
);
1290 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
1295 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
1296 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
1298 bb
= EXT4_MB_BUDDY(e4b
);
1299 while (order
<= e4b
->bd_blkbits
+ 1) {
1301 if (!mb_test_bit(block
, bb
)) {
1302 /* this block is part of buddy of order 'order' */
1305 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1311 static void mb_clear_bits(void *bm
, int cur
, int len
)
1317 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1318 /* fast path: clear whole word at once */
1319 addr
= bm
+ (cur
>> 3);
1324 mb_clear_bit(cur
, bm
);
1329 static void mb_set_bits(void *bm
, int cur
, int len
)
1335 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1336 /* fast path: set whole word at once */
1337 addr
= bm
+ (cur
>> 3);
1342 mb_set_bit(cur
, bm
);
1347 static void mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1348 int first
, int count
)
1355 struct super_block
*sb
= e4b
->bd_sb
;
1357 BUG_ON(first
+ count
> (sb
->s_blocksize
<< 3));
1358 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
1359 mb_check_buddy(e4b
);
1360 mb_free_blocks_double(inode
, e4b
, first
, count
);
1362 e4b
->bd_info
->bb_free
+= count
;
1363 if (first
< e4b
->bd_info
->bb_first_free
)
1364 e4b
->bd_info
->bb_first_free
= first
;
1366 /* let's maintain fragments counter */
1368 block
= !mb_test_bit(first
- 1, EXT4_MB_BITMAP(e4b
));
1369 if (first
+ count
< EXT4_SB(sb
)->s_mb_maxs
[0])
1370 max
= !mb_test_bit(first
+ count
, EXT4_MB_BITMAP(e4b
));
1372 e4b
->bd_info
->bb_fragments
--;
1373 else if (!block
&& !max
)
1374 e4b
->bd_info
->bb_fragments
++;
1376 /* let's maintain buddy itself */
1377 while (count
-- > 0) {
1381 if (!mb_test_bit(block
, EXT4_MB_BITMAP(e4b
))) {
1382 ext4_fsblk_t blocknr
;
1384 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1386 ext4_grp_locked_error(sb
, e4b
->bd_group
,
1387 inode
? inode
->i_ino
: 0,
1389 "freeing already freed block "
1392 mb_clear_bit(block
, EXT4_MB_BITMAP(e4b
));
1393 e4b
->bd_info
->bb_counters
[order
]++;
1395 /* start of the buddy */
1396 buddy
= mb_find_buddy(e4b
, order
, &max
);
1400 if (mb_test_bit(block
, buddy
) ||
1401 mb_test_bit(block
+ 1, buddy
))
1404 /* both the buddies are free, try to coalesce them */
1405 buddy2
= mb_find_buddy(e4b
, order
+ 1, &max
);
1411 /* for special purposes, we don't set
1412 * free bits in bitmap */
1413 mb_set_bit(block
, buddy
);
1414 mb_set_bit(block
+ 1, buddy
);
1416 e4b
->bd_info
->bb_counters
[order
]--;
1417 e4b
->bd_info
->bb_counters
[order
]--;
1421 e4b
->bd_info
->bb_counters
[order
]++;
1423 mb_clear_bit(block
, buddy2
);
1427 mb_set_largest_free_order(sb
, e4b
->bd_info
);
1428 mb_check_buddy(e4b
);
1431 static int mb_find_extent(struct ext4_buddy
*e4b
, int order
, int block
,
1432 int needed
, struct ext4_free_extent
*ex
)
1439 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1442 buddy
= mb_find_buddy(e4b
, order
, &max
);
1443 BUG_ON(buddy
== NULL
);
1444 BUG_ON(block
>= max
);
1445 if (mb_test_bit(block
, buddy
)) {
1452 /* FIXME dorp order completely ? */
1453 if (likely(order
== 0)) {
1454 /* find actual order */
1455 order
= mb_find_order_for_block(e4b
, block
);
1456 block
= block
>> order
;
1459 ex
->fe_len
= 1 << order
;
1460 ex
->fe_start
= block
<< order
;
1461 ex
->fe_group
= e4b
->bd_group
;
1463 /* calc difference from given start */
1464 next
= next
- ex
->fe_start
;
1466 ex
->fe_start
+= next
;
1468 while (needed
> ex
->fe_len
&&
1469 (buddy
= mb_find_buddy(e4b
, order
, &max
))) {
1471 if (block
+ 1 >= max
)
1474 next
= (block
+ 1) * (1 << order
);
1475 if (mb_test_bit(next
, EXT4_MB_BITMAP(e4b
)))
1478 ord
= mb_find_order_for_block(e4b
, next
);
1481 block
= next
>> order
;
1482 ex
->fe_len
+= 1 << order
;
1485 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1489 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1495 int start
= ex
->fe_start
;
1496 int len
= ex
->fe_len
;
1501 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1502 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1503 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1504 mb_check_buddy(e4b
);
1505 mb_mark_used_double(e4b
, start
, len
);
1507 e4b
->bd_info
->bb_free
-= len
;
1508 if (e4b
->bd_info
->bb_first_free
== start
)
1509 e4b
->bd_info
->bb_first_free
+= len
;
1511 /* let's maintain fragments counter */
1513 mlen
= !mb_test_bit(start
- 1, EXT4_MB_BITMAP(e4b
));
1514 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1515 max
= !mb_test_bit(start
+ len
, EXT4_MB_BITMAP(e4b
));
1517 e4b
->bd_info
->bb_fragments
++;
1518 else if (!mlen
&& !max
)
1519 e4b
->bd_info
->bb_fragments
--;
1521 /* let's maintain buddy itself */
1523 ord
= mb_find_order_for_block(e4b
, start
);
1525 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1526 /* the whole chunk may be allocated at once! */
1528 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1529 BUG_ON((start
>> ord
) >= max
);
1530 mb_set_bit(start
>> ord
, buddy
);
1531 e4b
->bd_info
->bb_counters
[ord
]--;
1538 /* store for history */
1540 ret
= len
| (ord
<< 16);
1542 /* we have to split large buddy */
1544 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1545 mb_set_bit(start
>> ord
, buddy
);
1546 e4b
->bd_info
->bb_counters
[ord
]--;
1549 cur
= (start
>> ord
) & ~1U;
1550 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1551 mb_clear_bit(cur
, buddy
);
1552 mb_clear_bit(cur
+ 1, buddy
);
1553 e4b
->bd_info
->bb_counters
[ord
]++;
1554 e4b
->bd_info
->bb_counters
[ord
]++;
1556 mb_set_largest_free_order(e4b
->bd_sb
, e4b
->bd_info
);
1558 mb_set_bits(EXT4_MB_BITMAP(e4b
), ex
->fe_start
, len0
);
1559 mb_check_buddy(e4b
);
1565 * Must be called under group lock!
1567 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1568 struct ext4_buddy
*e4b
)
1570 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1573 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1574 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1576 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1577 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1578 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1580 /* preallocation can change ac_b_ex, thus we store actually
1581 * allocated blocks for history */
1582 ac
->ac_f_ex
= ac
->ac_b_ex
;
1584 ac
->ac_status
= AC_STATUS_FOUND
;
1585 ac
->ac_tail
= ret
& 0xffff;
1586 ac
->ac_buddy
= ret
>> 16;
1589 * take the page reference. We want the page to be pinned
1590 * so that we don't get a ext4_mb_init_cache_call for this
1591 * group until we update the bitmap. That would mean we
1592 * double allocate blocks. The reference is dropped
1593 * in ext4_mb_release_context
1595 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1596 get_page(ac
->ac_bitmap_page
);
1597 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1598 get_page(ac
->ac_buddy_page
);
1599 /* on allocation we use ac to track the held semaphore */
1600 ac
->alloc_semp
= e4b
->alloc_semp
;
1601 e4b
->alloc_semp
= NULL
;
1602 /* store last allocated for subsequent stream allocation */
1603 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
1604 spin_lock(&sbi
->s_md_lock
);
1605 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1606 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1607 spin_unlock(&sbi
->s_md_lock
);
1612 * regular allocator, for general purposes allocation
1615 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1616 struct ext4_buddy
*e4b
,
1619 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1620 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1621 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1622 struct ext4_free_extent ex
;
1625 if (ac
->ac_status
== AC_STATUS_FOUND
)
1628 * We don't want to scan for a whole year
1630 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1631 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1632 ac
->ac_status
= AC_STATUS_BREAK
;
1637 * Haven't found good chunk so far, let's continue
1639 if (bex
->fe_len
< gex
->fe_len
)
1642 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1643 && bex
->fe_group
== e4b
->bd_group
) {
1644 /* recheck chunk's availability - we don't know
1645 * when it was found (within this lock-unlock
1647 max
= mb_find_extent(e4b
, 0, bex
->fe_start
, gex
->fe_len
, &ex
);
1648 if (max
>= gex
->fe_len
) {
1649 ext4_mb_use_best_found(ac
, e4b
);
1656 * The routine checks whether found extent is good enough. If it is,
1657 * then the extent gets marked used and flag is set to the context
1658 * to stop scanning. Otherwise, the extent is compared with the
1659 * previous found extent and if new one is better, then it's stored
1660 * in the context. Later, the best found extent will be used, if
1661 * mballoc can't find good enough extent.
1663 * FIXME: real allocation policy is to be designed yet!
1665 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1666 struct ext4_free_extent
*ex
,
1667 struct ext4_buddy
*e4b
)
1669 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1670 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1672 BUG_ON(ex
->fe_len
<= 0);
1673 BUG_ON(ex
->fe_len
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1674 BUG_ON(ex
->fe_start
>= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
1675 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1680 * The special case - take what you catch first
1682 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1684 ext4_mb_use_best_found(ac
, e4b
);
1689 * Let's check whether the chuck is good enough
1691 if (ex
->fe_len
== gex
->fe_len
) {
1693 ext4_mb_use_best_found(ac
, e4b
);
1698 * If this is first found extent, just store it in the context
1700 if (bex
->fe_len
== 0) {
1706 * If new found extent is better, store it in the context
1708 if (bex
->fe_len
< gex
->fe_len
) {
1709 /* if the request isn't satisfied, any found extent
1710 * larger than previous best one is better */
1711 if (ex
->fe_len
> bex
->fe_len
)
1713 } else if (ex
->fe_len
> gex
->fe_len
) {
1714 /* if the request is satisfied, then we try to find
1715 * an extent that still satisfy the request, but is
1716 * smaller than previous one */
1717 if (ex
->fe_len
< bex
->fe_len
)
1721 ext4_mb_check_limits(ac
, e4b
, 0);
1724 static noinline_for_stack
1725 int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1726 struct ext4_buddy
*e4b
)
1728 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1729 ext4_group_t group
= ex
.fe_group
;
1733 BUG_ON(ex
.fe_len
<= 0);
1734 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1738 ext4_lock_group(ac
->ac_sb
, group
);
1739 max
= mb_find_extent(e4b
, 0, ex
.fe_start
, ex
.fe_len
, &ex
);
1743 ext4_mb_use_best_found(ac
, e4b
);
1746 ext4_unlock_group(ac
->ac_sb
, group
);
1747 ext4_mb_unload_buddy(e4b
);
1752 static noinline_for_stack
1753 int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1754 struct ext4_buddy
*e4b
)
1756 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1759 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1760 struct ext4_free_extent ex
;
1762 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1765 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1769 ext4_lock_group(ac
->ac_sb
, group
);
1770 max
= mb_find_extent(e4b
, 0, ac
->ac_g_ex
.fe_start
,
1771 ac
->ac_g_ex
.fe_len
, &ex
);
1773 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1776 start
= ext4_group_first_block_no(ac
->ac_sb
, e4b
->bd_group
) +
1778 /* use do_div to get remainder (would be 64-bit modulo) */
1779 if (do_div(start
, sbi
->s_stripe
) == 0) {
1782 ext4_mb_use_best_found(ac
, e4b
);
1784 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1785 BUG_ON(ex
.fe_len
<= 0);
1786 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1787 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1790 ext4_mb_use_best_found(ac
, e4b
);
1791 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1792 /* Sometimes, caller may want to merge even small
1793 * number of blocks to an existing extent */
1794 BUG_ON(ex
.fe_len
<= 0);
1795 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1796 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1799 ext4_mb_use_best_found(ac
, e4b
);
1801 ext4_unlock_group(ac
->ac_sb
, group
);
1802 ext4_mb_unload_buddy(e4b
);
1808 * The routine scans buddy structures (not bitmap!) from given order
1809 * to max order and tries to find big enough chunk to satisfy the req
1811 static noinline_for_stack
1812 void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1813 struct ext4_buddy
*e4b
)
1815 struct super_block
*sb
= ac
->ac_sb
;
1816 struct ext4_group_info
*grp
= e4b
->bd_info
;
1822 BUG_ON(ac
->ac_2order
<= 0);
1823 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1824 if (grp
->bb_counters
[i
] == 0)
1827 buddy
= mb_find_buddy(e4b
, i
, &max
);
1828 BUG_ON(buddy
== NULL
);
1830 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1835 ac
->ac_b_ex
.fe_len
= 1 << i
;
1836 ac
->ac_b_ex
.fe_start
= k
<< i
;
1837 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1839 ext4_mb_use_best_found(ac
, e4b
);
1841 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1843 if (EXT4_SB(sb
)->s_mb_stats
)
1844 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1851 * The routine scans the group and measures all found extents.
1852 * In order to optimize scanning, caller must pass number of
1853 * free blocks in the group, so the routine can know upper limit.
1855 static noinline_for_stack
1856 void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1857 struct ext4_buddy
*e4b
)
1859 struct super_block
*sb
= ac
->ac_sb
;
1860 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1861 struct ext4_free_extent ex
;
1865 free
= e4b
->bd_info
->bb_free
;
1868 i
= e4b
->bd_info
->bb_first_free
;
1870 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1871 i
= mb_find_next_zero_bit(bitmap
,
1872 EXT4_BLOCKS_PER_GROUP(sb
), i
);
1873 if (i
>= EXT4_BLOCKS_PER_GROUP(sb
)) {
1875 * IF we have corrupt bitmap, we won't find any
1876 * free blocks even though group info says we
1877 * we have free blocks
1879 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1880 "%d free blocks as per "
1881 "group info. But bitmap says 0",
1886 mb_find_extent(e4b
, 0, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1887 BUG_ON(ex
.fe_len
<= 0);
1888 if (free
< ex
.fe_len
) {
1889 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1890 "%d free blocks as per "
1891 "group info. But got %d blocks",
1894 * The number of free blocks differs. This mostly
1895 * indicate that the bitmap is corrupt. So exit
1896 * without claiming the space.
1901 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1907 ext4_mb_check_limits(ac
, e4b
, 1);
1911 * This is a special case for storages like raid5
1912 * we try to find stripe-aligned chunks for stripe-size-multiple requests
1914 static noinline_for_stack
1915 void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1916 struct ext4_buddy
*e4b
)
1918 struct super_block
*sb
= ac
->ac_sb
;
1919 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1920 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1921 struct ext4_free_extent ex
;
1922 ext4_fsblk_t first_group_block
;
1927 BUG_ON(sbi
->s_stripe
== 0);
1929 /* find first stripe-aligned block in group */
1930 first_group_block
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1932 a
= first_group_block
+ sbi
->s_stripe
- 1;
1933 do_div(a
, sbi
->s_stripe
);
1934 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1936 while (i
< EXT4_BLOCKS_PER_GROUP(sb
)) {
1937 if (!mb_test_bit(i
, bitmap
)) {
1938 max
= mb_find_extent(e4b
, 0, i
, sbi
->s_stripe
, &ex
);
1939 if (max
>= sbi
->s_stripe
) {
1942 ext4_mb_use_best_found(ac
, e4b
);
1950 /* This is now called BEFORE we load the buddy bitmap. */
1951 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
1952 ext4_group_t group
, int cr
)
1954 unsigned free
, fragments
;
1955 int flex_size
= ext4_flex_bg_size(EXT4_SB(ac
->ac_sb
));
1956 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1958 BUG_ON(cr
< 0 || cr
>= 4);
1960 /* We only do this if the grp has never been initialized */
1961 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1962 int ret
= ext4_mb_init_group(ac
->ac_sb
, group
);
1967 free
= grp
->bb_free
;
1968 fragments
= grp
->bb_fragments
;
1976 BUG_ON(ac
->ac_2order
== 0);
1978 if (grp
->bb_largest_free_order
< ac
->ac_2order
)
1981 /* Avoid using the first bg of a flexgroup for data files */
1982 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
) &&
1983 (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) &&
1984 ((group
% flex_size
) == 0))
1989 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
1993 if (free
>= ac
->ac_g_ex
.fe_len
)
2005 static noinline_for_stack
int
2006 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
2008 ext4_group_t ngroups
, group
, i
;
2011 struct ext4_sb_info
*sbi
;
2012 struct super_block
*sb
;
2013 struct ext4_buddy e4b
;
2017 ngroups
= ext4_get_groups_count(sb
);
2018 /* non-extent files are limited to low blocks/groups */
2019 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)))
2020 ngroups
= sbi
->s_blockfile_groups
;
2022 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
2024 /* first, try the goal */
2025 err
= ext4_mb_find_by_goal(ac
, &e4b
);
2026 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
2029 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2033 * ac->ac2_order is set only if the fe_len is a power of 2
2034 * if ac2_order is set we also set criteria to 0 so that we
2035 * try exact allocation using buddy.
2037 i
= fls(ac
->ac_g_ex
.fe_len
);
2040 * We search using buddy data only if the order of the request
2041 * is greater than equal to the sbi_s_mb_order2_reqs
2042 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2044 if (i
>= sbi
->s_mb_order2_reqs
) {
2046 * This should tell if fe_len is exactly power of 2
2048 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
2049 ac
->ac_2order
= i
- 1;
2052 /* if stream allocation is enabled, use global goal */
2053 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
2054 /* TBD: may be hot point */
2055 spin_lock(&sbi
->s_md_lock
);
2056 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
2057 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
2058 spin_unlock(&sbi
->s_md_lock
);
2061 /* Let's just scan groups to find more-less suitable blocks */
2062 cr
= ac
->ac_2order
? 0 : 1;
2064 * cr == 0 try to get exact allocation,
2065 * cr == 3 try to get anything
2068 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
2069 ac
->ac_criteria
= cr
;
2071 * searching for the right group start
2072 * from the goal value specified
2074 group
= ac
->ac_g_ex
.fe_group
;
2076 for (i
= 0; i
< ngroups
; group
++, i
++) {
2077 if (group
== ngroups
)
2080 /* This now checks without needing the buddy page */
2081 if (!ext4_mb_good_group(ac
, group
, cr
))
2084 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2088 ext4_lock_group(sb
, group
);
2091 * We need to check again after locking the
2094 if (!ext4_mb_good_group(ac
, group
, cr
)) {
2095 ext4_unlock_group(sb
, group
);
2096 ext4_mb_unload_buddy(&e4b
);
2100 ac
->ac_groups_scanned
++;
2102 ext4_mb_simple_scan_group(ac
, &e4b
);
2103 else if (cr
== 1 && sbi
->s_stripe
&&
2104 !(ac
->ac_g_ex
.fe_len
% sbi
->s_stripe
))
2105 ext4_mb_scan_aligned(ac
, &e4b
);
2107 ext4_mb_complex_scan_group(ac
, &e4b
);
2109 ext4_unlock_group(sb
, group
);
2110 ext4_mb_unload_buddy(&e4b
);
2112 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
2117 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
2118 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
2120 * We've been searching too long. Let's try to allocate
2121 * the best chunk we've found so far
2124 ext4_mb_try_best_found(ac
, &e4b
);
2125 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
2127 * Someone more lucky has already allocated it.
2128 * The only thing we can do is just take first
2130 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2132 ac
->ac_b_ex
.fe_group
= 0;
2133 ac
->ac_b_ex
.fe_start
= 0;
2134 ac
->ac_b_ex
.fe_len
= 0;
2135 ac
->ac_status
= AC_STATUS_CONTINUE
;
2136 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
2138 atomic_inc(&sbi
->s_mb_lost_chunks
);
2146 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2148 struct super_block
*sb
= seq
->private;
2151 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2154 return (void *) ((unsigned long) group
);
2157 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2159 struct super_block
*sb
= seq
->private;
2163 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2166 return (void *) ((unsigned long) group
);
2169 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2171 struct super_block
*sb
= seq
->private;
2172 ext4_group_t group
= (ext4_group_t
) ((unsigned long) v
);
2175 struct ext4_buddy e4b
;
2177 struct ext4_group_info info
;
2178 ext4_grpblk_t counters
[16];
2183 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2184 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2185 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2186 "group", "free", "frags", "first",
2187 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2188 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2190 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2191 sizeof(struct ext4_group_info
);
2192 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2194 seq_printf(seq
, "#%-5u: I/O error\n", group
);
2197 ext4_lock_group(sb
, group
);
2198 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2199 ext4_unlock_group(sb
, group
);
2200 ext4_mb_unload_buddy(&e4b
);
2202 seq_printf(seq
, "#%-5u: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2203 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2204 for (i
= 0; i
<= 13; i
++)
2205 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2206 sg
.info
.bb_counters
[i
] : 0);
2207 seq_printf(seq
, " ]\n");
2212 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2216 static const struct seq_operations ext4_mb_seq_groups_ops
= {
2217 .start
= ext4_mb_seq_groups_start
,
2218 .next
= ext4_mb_seq_groups_next
,
2219 .stop
= ext4_mb_seq_groups_stop
,
2220 .show
= ext4_mb_seq_groups_show
,
2223 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2225 struct super_block
*sb
= PDE(inode
)->data
;
2228 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2230 struct seq_file
*m
= file
->private_data
;
2237 static const struct file_operations ext4_mb_seq_groups_fops
= {
2238 .owner
= THIS_MODULE
,
2239 .open
= ext4_mb_seq_groups_open
,
2241 .llseek
= seq_lseek
,
2242 .release
= seq_release
,
2245 static struct kmem_cache
*get_groupinfo_cache(int blocksize_bits
)
2247 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2248 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[cache_index
];
2254 /* Create and initialize ext4_group_info data for the given group. */
2255 int ext4_mb_add_groupinfo(struct super_block
*sb
, ext4_group_t group
,
2256 struct ext4_group_desc
*desc
)
2260 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2261 struct ext4_group_info
**meta_group_info
;
2262 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2265 * First check if this group is the first of a reserved block.
2266 * If it's true, we have to allocate a new table of pointers
2267 * to ext4_group_info structures
2269 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2270 metalen
= sizeof(*meta_group_info
) <<
2271 EXT4_DESC_PER_BLOCK_BITS(sb
);
2272 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2273 if (meta_group_info
== NULL
) {
2274 printk(KERN_ERR
"EXT4-fs: can't allocate mem for a "
2276 goto exit_meta_group_info
;
2278 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] =
2283 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2284 i
= group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2286 meta_group_info
[i
] = kmem_cache_alloc(cachep
, GFP_KERNEL
);
2287 if (meta_group_info
[i
] == NULL
) {
2288 printk(KERN_ERR
"EXT4-fs: can't allocate buddy mem\n");
2289 goto exit_group_info
;
2291 memset(meta_group_info
[i
], 0, kmem_cache_size(cachep
));
2292 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2293 &(meta_group_info
[i
]->bb_state
));
2296 * initialize bb_free to be able to skip
2297 * empty groups without initialization
2299 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2300 meta_group_info
[i
]->bb_free
=
2301 ext4_free_blocks_after_init(sb
, group
, desc
);
2303 meta_group_info
[i
]->bb_free
=
2304 ext4_free_blks_count(sb
, desc
);
2307 INIT_LIST_HEAD(&meta_group_info
[i
]->bb_prealloc_list
);
2308 init_rwsem(&meta_group_info
[i
]->alloc_sem
);
2309 meta_group_info
[i
]->bb_free_root
= RB_ROOT
;
2310 meta_group_info
[i
]->bb_largest_free_order
= -1; /* uninit */
2314 struct buffer_head
*bh
;
2315 meta_group_info
[i
]->bb_bitmap
=
2316 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2317 BUG_ON(meta_group_info
[i
]->bb_bitmap
== NULL
);
2318 bh
= ext4_read_block_bitmap(sb
, group
);
2320 memcpy(meta_group_info
[i
]->bb_bitmap
, bh
->b_data
,
2329 /* If a meta_group_info table has been allocated, release it now */
2330 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0)
2331 kfree(sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)]);
2332 exit_meta_group_info
:
2334 } /* ext4_mb_add_groupinfo */
2336 static int ext4_mb_init_backend(struct super_block
*sb
)
2338 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2340 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2341 struct ext4_super_block
*es
= sbi
->s_es
;
2342 int num_meta_group_infos
;
2343 int num_meta_group_infos_max
;
2345 struct ext4_group_desc
*desc
;
2346 struct kmem_cache
*cachep
;
2348 /* This is the number of blocks used by GDT */
2349 num_meta_group_infos
= (ngroups
+ EXT4_DESC_PER_BLOCK(sb
) -
2350 1) >> EXT4_DESC_PER_BLOCK_BITS(sb
);
2353 * This is the total number of blocks used by GDT including
2354 * the number of reserved blocks for GDT.
2355 * The s_group_info array is allocated with this value
2356 * to allow a clean online resize without a complex
2357 * manipulation of pointer.
2358 * The drawback is the unused memory when no resize
2359 * occurs but it's very low in terms of pages
2360 * (see comments below)
2361 * Need to handle this properly when META_BG resizing is allowed
2363 num_meta_group_infos_max
= num_meta_group_infos
+
2364 le16_to_cpu(es
->s_reserved_gdt_blocks
);
2367 * array_size is the size of s_group_info array. We round it
2368 * to the next power of two because this approximation is done
2369 * internally by kmalloc so we can have some more memory
2370 * for free here (e.g. may be used for META_BG resize).
2373 while (array_size
< sizeof(*sbi
->s_group_info
) *
2374 num_meta_group_infos_max
)
2375 array_size
= array_size
<< 1;
2376 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2377 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2378 * So a two level scheme suffices for now. */
2379 sbi
->s_group_info
= kmalloc(array_size
, GFP_KERNEL
);
2380 if (sbi
->s_group_info
== NULL
) {
2381 printk(KERN_ERR
"EXT4-fs: can't allocate buddy meta group\n");
2384 sbi
->s_buddy_cache
= new_inode(sb
);
2385 if (sbi
->s_buddy_cache
== NULL
) {
2386 printk(KERN_ERR
"EXT4-fs: can't get new inode\n");
2389 sbi
->s_buddy_cache
->i_ino
= get_next_ino();
2390 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2391 for (i
= 0; i
< ngroups
; i
++) {
2392 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2395 "EXT4-fs: can't read descriptor %u\n", i
);
2398 if (ext4_mb_add_groupinfo(sb
, i
, desc
) != 0)
2405 cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2407 kmem_cache_free(cachep
, ext4_get_group_info(sb
, i
));
2408 i
= num_meta_group_infos
;
2410 kfree(sbi
->s_group_info
[i
]);
2411 iput(sbi
->s_buddy_cache
);
2413 kfree(sbi
->s_group_info
);
2417 int ext4_mb_init(struct super_block
*sb
, int needs_recovery
)
2419 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2425 struct kmem_cache
*cachep
;
2428 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_offsets
);
2430 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2431 if (sbi
->s_mb_offsets
== NULL
) {
2436 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_maxs
);
2437 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2438 if (sbi
->s_mb_maxs
== NULL
) {
2443 cache_index
= sb
->s_blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2444 cachep
= ext4_groupinfo_caches
[cache_index
];
2447 int len
= offsetof(struct ext4_group_info
,
2448 bb_counters
[sb
->s_blocksize_bits
+ 2]);
2450 sprintf(name
, "ext4_groupinfo_%d", sb
->s_blocksize_bits
);
2451 namep
= kstrdup(name
, GFP_KERNEL
);
2457 /* Need to free the kmem_cache_name() when we
2458 * destroy the slab */
2459 cachep
= kmem_cache_create(namep
, len
, 0,
2460 SLAB_RECLAIM_ACCOUNT
, NULL
);
2465 ext4_groupinfo_caches
[cache_index
] = cachep
;
2468 /* order 0 is regular bitmap */
2469 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2470 sbi
->s_mb_offsets
[0] = 0;
2474 max
= sb
->s_blocksize
<< 2;
2476 sbi
->s_mb_offsets
[i
] = offset
;
2477 sbi
->s_mb_maxs
[i
] = max
;
2478 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2481 } while (i
<= sb
->s_blocksize_bits
+ 1);
2483 /* init file for buddy data */
2484 ret
= ext4_mb_init_backend(sb
);
2489 spin_lock_init(&sbi
->s_md_lock
);
2490 spin_lock_init(&sbi
->s_bal_lock
);
2492 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2493 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2494 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2495 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2496 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2497 sbi
->s_mb_group_prealloc
= MB_DEFAULT_GROUP_PREALLOC
;
2499 sbi
->s_locality_groups
= alloc_percpu(struct ext4_locality_group
);
2500 if (sbi
->s_locality_groups
== NULL
) {
2504 for_each_possible_cpu(i
) {
2505 struct ext4_locality_group
*lg
;
2506 lg
= per_cpu_ptr(sbi
->s_locality_groups
, i
);
2507 mutex_init(&lg
->lg_mutex
);
2508 for (j
= 0; j
< PREALLOC_TB_SIZE
; j
++)
2509 INIT_LIST_HEAD(&lg
->lg_prealloc_list
[j
]);
2510 spin_lock_init(&lg
->lg_prealloc_lock
);
2514 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_proc
,
2515 &ext4_mb_seq_groups_fops
, sb
);
2518 sbi
->s_journal
->j_commit_callback
= release_blocks_on_commit
;
2521 kfree(sbi
->s_mb_offsets
);
2522 kfree(sbi
->s_mb_maxs
);
2528 /* need to called with the ext4 group lock held */
2529 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2531 struct ext4_prealloc_space
*pa
;
2532 struct list_head
*cur
, *tmp
;
2535 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2536 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2537 list_del(&pa
->pa_group_list
);
2539 kmem_cache_free(ext4_pspace_cachep
, pa
);
2542 mb_debug(1, "mballoc: %u PAs left\n", count
);
2546 int ext4_mb_release(struct super_block
*sb
)
2548 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2550 int num_meta_group_infos
;
2551 struct ext4_group_info
*grinfo
;
2552 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2553 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2555 if (sbi
->s_group_info
) {
2556 for (i
= 0; i
< ngroups
; i
++) {
2557 grinfo
= ext4_get_group_info(sb
, i
);
2559 kfree(grinfo
->bb_bitmap
);
2561 ext4_lock_group(sb
, i
);
2562 ext4_mb_cleanup_pa(grinfo
);
2563 ext4_unlock_group(sb
, i
);
2564 kmem_cache_free(cachep
, grinfo
);
2566 num_meta_group_infos
= (ngroups
+
2567 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2568 EXT4_DESC_PER_BLOCK_BITS(sb
);
2569 for (i
= 0; i
< num_meta_group_infos
; i
++)
2570 kfree(sbi
->s_group_info
[i
]);
2571 kfree(sbi
->s_group_info
);
2573 kfree(sbi
->s_mb_offsets
);
2574 kfree(sbi
->s_mb_maxs
);
2575 if (sbi
->s_buddy_cache
)
2576 iput(sbi
->s_buddy_cache
);
2577 if (sbi
->s_mb_stats
) {
2579 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2580 atomic_read(&sbi
->s_bal_allocated
),
2581 atomic_read(&sbi
->s_bal_reqs
),
2582 atomic_read(&sbi
->s_bal_success
));
2584 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2585 "%u 2^N hits, %u breaks, %u lost\n",
2586 atomic_read(&sbi
->s_bal_ex_scanned
),
2587 atomic_read(&sbi
->s_bal_goals
),
2588 atomic_read(&sbi
->s_bal_2orders
),
2589 atomic_read(&sbi
->s_bal_breaks
),
2590 atomic_read(&sbi
->s_mb_lost_chunks
));
2592 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2593 sbi
->s_mb_buddies_generated
++,
2594 sbi
->s_mb_generation_time
);
2596 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2597 atomic_read(&sbi
->s_mb_preallocated
),
2598 atomic_read(&sbi
->s_mb_discarded
));
2601 free_percpu(sbi
->s_locality_groups
);
2603 remove_proc_entry("mb_groups", sbi
->s_proc
);
2608 static inline int ext4_issue_discard(struct super_block
*sb
,
2609 ext4_group_t block_group
, ext4_grpblk_t block
, int count
)
2612 ext4_fsblk_t discard_block
;
2614 discard_block
= block
+ ext4_group_first_block_no(sb
, block_group
);
2615 trace_ext4_discard_blocks(sb
,
2616 (unsigned long long) discard_block
, count
);
2617 ret
= sb_issue_discard(sb
, discard_block
, count
, GFP_NOFS
, 0);
2618 if (ret
== -EOPNOTSUPP
) {
2619 ext4_warning(sb
, "discard not supported, disabling");
2620 clear_opt(EXT4_SB(sb
)->s_mount_opt
, DISCARD
);
2626 * This function is called by the jbd2 layer once the commit has finished,
2627 * so we know we can free the blocks that were released with that commit.
2629 static void release_blocks_on_commit(journal_t
*journal
, transaction_t
*txn
)
2631 struct super_block
*sb
= journal
->j_private
;
2632 struct ext4_buddy e4b
;
2633 struct ext4_group_info
*db
;
2634 int err
, count
= 0, count2
= 0;
2635 struct ext4_free_data
*entry
;
2636 struct list_head
*l
, *ltmp
;
2638 list_for_each_safe(l
, ltmp
, &txn
->t_private_list
) {
2639 entry
= list_entry(l
, struct ext4_free_data
, list
);
2641 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2642 entry
->count
, entry
->group
, entry
);
2644 if (test_opt(sb
, DISCARD
))
2645 ext4_issue_discard(sb
, entry
->group
,
2646 entry
->start_blk
, entry
->count
);
2648 err
= ext4_mb_load_buddy(sb
, entry
->group
, &e4b
);
2649 /* we expect to find existing buddy because it's pinned */
2653 /* there are blocks to put in buddy to make them really free */
2654 count
+= entry
->count
;
2656 ext4_lock_group(sb
, entry
->group
);
2657 /* Take it out of per group rb tree */
2658 rb_erase(&entry
->node
, &(db
->bb_free_root
));
2659 mb_free_blocks(NULL
, &e4b
, entry
->start_blk
, entry
->count
);
2661 if (!db
->bb_free_root
.rb_node
) {
2662 /* No more items in the per group rb tree
2663 * balance refcounts from ext4_mb_free_metadata()
2665 page_cache_release(e4b
.bd_buddy_page
);
2666 page_cache_release(e4b
.bd_bitmap_page
);
2668 ext4_unlock_group(sb
, entry
->group
);
2669 kmem_cache_free(ext4_free_ext_cachep
, entry
);
2670 ext4_mb_unload_buddy(&e4b
);
2673 mb_debug(1, "freed %u blocks in %u structures\n", count
, count2
);
2676 #ifdef CONFIG_EXT4_DEBUG
2677 u8 mb_enable_debug __read_mostly
;
2679 static struct dentry
*debugfs_dir
;
2680 static struct dentry
*debugfs_debug
;
2682 static void __init
ext4_create_debugfs_entry(void)
2684 debugfs_dir
= debugfs_create_dir("ext4", NULL
);
2686 debugfs_debug
= debugfs_create_u8("mballoc-debug",
2692 static void ext4_remove_debugfs_entry(void)
2694 debugfs_remove(debugfs_debug
);
2695 debugfs_remove(debugfs_dir
);
2700 static void __init
ext4_create_debugfs_entry(void)
2704 static void ext4_remove_debugfs_entry(void)
2710 int __init
ext4_init_mballoc(void)
2712 ext4_pspace_cachep
= KMEM_CACHE(ext4_prealloc_space
,
2713 SLAB_RECLAIM_ACCOUNT
);
2714 if (ext4_pspace_cachep
== NULL
)
2717 ext4_ac_cachep
= KMEM_CACHE(ext4_allocation_context
,
2718 SLAB_RECLAIM_ACCOUNT
);
2719 if (ext4_ac_cachep
== NULL
) {
2720 kmem_cache_destroy(ext4_pspace_cachep
);
2724 ext4_free_ext_cachep
= KMEM_CACHE(ext4_free_data
,
2725 SLAB_RECLAIM_ACCOUNT
);
2726 if (ext4_free_ext_cachep
== NULL
) {
2727 kmem_cache_destroy(ext4_pspace_cachep
);
2728 kmem_cache_destroy(ext4_ac_cachep
);
2731 ext4_create_debugfs_entry();
2735 void ext4_exit_mballoc(void)
2739 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2740 * before destroying the slab cache.
2743 kmem_cache_destroy(ext4_pspace_cachep
);
2744 kmem_cache_destroy(ext4_ac_cachep
);
2745 kmem_cache_destroy(ext4_free_ext_cachep
);
2747 for (i
= 0; i
< NR_GRPINFO_CACHES
; i
++) {
2748 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[i
];
2750 char *name
= (char *)kmem_cache_name(cachep
);
2751 kmem_cache_destroy(cachep
);
2755 ext4_remove_debugfs_entry();
2760 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2761 * Returns 0 if success or error code
2763 static noinline_for_stack
int
2764 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2765 handle_t
*handle
, unsigned int reserv_blks
)
2767 struct buffer_head
*bitmap_bh
= NULL
;
2768 struct ext4_group_desc
*gdp
;
2769 struct buffer_head
*gdp_bh
;
2770 struct ext4_sb_info
*sbi
;
2771 struct super_block
*sb
;
2775 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2776 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2782 bitmap_bh
= ext4_read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2786 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2791 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2795 ext4_debug("using block group %u(%d)\n", ac
->ac_b_ex
.fe_group
,
2796 ext4_free_blks_count(sb
, gdp
));
2798 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2802 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
2804 len
= ac
->ac_b_ex
.fe_len
;
2805 if (!ext4_data_block_valid(sbi
, block
, len
)) {
2806 ext4_error(sb
, "Allocating blocks %llu-%llu which overlap "
2807 "fs metadata\n", block
, block
+len
);
2808 /* File system mounted not to panic on error
2809 * Fix the bitmap and repeat the block allocation
2810 * We leak some of the blocks here.
2812 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2813 mb_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2814 ac
->ac_b_ex
.fe_len
);
2815 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2816 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2822 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2823 #ifdef AGGRESSIVE_CHECK
2826 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2827 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2828 bitmap_bh
->b_data
));
2832 mb_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,ac
->ac_b_ex
.fe_len
);
2833 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2834 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2835 ext4_free_blks_set(sb
, gdp
,
2836 ext4_free_blocks_after_init(sb
,
2837 ac
->ac_b_ex
.fe_group
, gdp
));
2839 len
= ext4_free_blks_count(sb
, gdp
) - ac
->ac_b_ex
.fe_len
;
2840 ext4_free_blks_set(sb
, gdp
, len
);
2841 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, ac
->ac_b_ex
.fe_group
, gdp
);
2843 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2844 percpu_counter_sub(&sbi
->s_freeblocks_counter
, ac
->ac_b_ex
.fe_len
);
2846 * Now reduce the dirty block count also. Should not go negative
2848 if (!(ac
->ac_flags
& EXT4_MB_DELALLOC_RESERVED
))
2849 /* release all the reserved blocks if non delalloc */
2850 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
, reserv_blks
);
2852 if (sbi
->s_log_groups_per_flex
) {
2853 ext4_group_t flex_group
= ext4_flex_group(sbi
,
2854 ac
->ac_b_ex
.fe_group
);
2855 atomic_sub(ac
->ac_b_ex
.fe_len
,
2856 &sbi
->s_flex_groups
[flex_group
].free_blocks
);
2859 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2862 err
= ext4_handle_dirty_metadata(handle
, NULL
, gdp_bh
);
2865 ext4_mark_super_dirty(sb
);
2871 * here we normalize request for locality group
2872 * Group request are normalized to s_strip size if we set the same via mount
2873 * option. If not we set it to s_mb_group_prealloc which can be configured via
2874 * /sys/fs/ext4/<partition>/mb_group_prealloc
2876 * XXX: should we try to preallocate more than the group has now?
2878 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2880 struct super_block
*sb
= ac
->ac_sb
;
2881 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2884 if (EXT4_SB(sb
)->s_stripe
)
2885 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_stripe
;
2887 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2888 mb_debug(1, "#%u: goal %u blocks for locality group\n",
2889 current
->pid
, ac
->ac_g_ex
.fe_len
);
2893 * Normalization means making request better in terms of
2894 * size and alignment
2896 static noinline_for_stack
void
2897 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
2898 struct ext4_allocation_request
*ar
)
2902 loff_t size
, orig_size
, start_off
;
2904 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
2905 struct ext4_prealloc_space
*pa
;
2907 /* do normalize only data requests, metadata requests
2908 do not need preallocation */
2909 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
2912 /* sometime caller may want exact blocks */
2913 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2916 /* caller may indicate that preallocation isn't
2917 * required (it's a tail, for example) */
2918 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
2921 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
2922 ext4_mb_normalize_group_request(ac
);
2926 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
2928 /* first, let's learn actual file size
2929 * given current request is allocated */
2930 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
2931 size
= size
<< bsbits
;
2932 if (size
< i_size_read(ac
->ac_inode
))
2933 size
= i_size_read(ac
->ac_inode
);
2936 /* max size of free chunks */
2939 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
2940 (req <= (size) || max <= (chunk_size))
2942 /* first, try to predict filesize */
2943 /* XXX: should this table be tunable? */
2945 if (size
<= 16 * 1024) {
2947 } else if (size
<= 32 * 1024) {
2949 } else if (size
<= 64 * 1024) {
2951 } else if (size
<= 128 * 1024) {
2953 } else if (size
<= 256 * 1024) {
2955 } else if (size
<= 512 * 1024) {
2957 } else if (size
<= 1024 * 1024) {
2959 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
2960 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2961 (21 - bsbits
)) << 21;
2962 size
= 2 * 1024 * 1024;
2963 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
2964 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2965 (22 - bsbits
)) << 22;
2966 size
= 4 * 1024 * 1024;
2967 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
2968 (8<<20)>>bsbits
, max
, 8 * 1024)) {
2969 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2970 (23 - bsbits
)) << 23;
2971 size
= 8 * 1024 * 1024;
2973 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
2974 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
2976 size
= size
>> bsbits
;
2977 start
= start_off
>> bsbits
;
2979 /* don't cover already allocated blocks in selected range */
2980 if (ar
->pleft
&& start
<= ar
->lleft
) {
2981 size
-= ar
->lleft
+ 1 - start
;
2982 start
= ar
->lleft
+ 1;
2984 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
2985 size
-= start
+ size
- ar
->lright
;
2989 /* check we don't cross already preallocated blocks */
2991 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
2996 spin_lock(&pa
->pa_lock
);
2997 if (pa
->pa_deleted
) {
2998 spin_unlock(&pa
->pa_lock
);
3002 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
3004 /* PA must not overlap original request */
3005 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
3006 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
3008 /* skip PAs this normalized request doesn't overlap with */
3009 if (pa
->pa_lstart
>= end
|| pa_end
<= start
) {
3010 spin_unlock(&pa
->pa_lock
);
3013 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
3015 /* adjust start or end to be adjacent to this pa */
3016 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
3017 BUG_ON(pa_end
< start
);
3019 } else if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
3020 BUG_ON(pa
->pa_lstart
> end
);
3021 end
= pa
->pa_lstart
;
3023 spin_unlock(&pa
->pa_lock
);
3028 /* XXX: extra loop to check we really don't overlap preallocations */
3030 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3032 spin_lock(&pa
->pa_lock
);
3033 if (pa
->pa_deleted
== 0) {
3034 pa_end
= pa
->pa_lstart
+ pa
->pa_len
;
3035 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3037 spin_unlock(&pa
->pa_lock
);
3041 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3042 start
> ac
->ac_o_ex
.fe_logical
) {
3043 printk(KERN_ERR
"start %lu, size %lu, fe_logical %lu\n",
3044 (unsigned long) start
, (unsigned long) size
,
3045 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3047 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3048 start
> ac
->ac_o_ex
.fe_logical
);
3049 BUG_ON(size
<= 0 || size
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3051 /* now prepare goal request */
3053 /* XXX: is it better to align blocks WRT to logical
3054 * placement or satisfy big request as is */
3055 ac
->ac_g_ex
.fe_logical
= start
;
3056 ac
->ac_g_ex
.fe_len
= size
;
3058 /* define goal start in order to merge */
3059 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3060 /* merge to the right */
3061 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3062 &ac
->ac_f_ex
.fe_group
,
3063 &ac
->ac_f_ex
.fe_start
);
3064 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3066 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3067 /* merge to the left */
3068 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3069 &ac
->ac_f_ex
.fe_group
,
3070 &ac
->ac_f_ex
.fe_start
);
3071 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3074 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3075 (unsigned) orig_size
, (unsigned) start
);
3078 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3080 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3082 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3083 atomic_inc(&sbi
->s_bal_reqs
);
3084 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3085 if (ac
->ac_b_ex
.fe_len
>= ac
->ac_o_ex
.fe_len
)
3086 atomic_inc(&sbi
->s_bal_success
);
3087 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3088 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3089 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3090 atomic_inc(&sbi
->s_bal_goals
);
3091 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3092 atomic_inc(&sbi
->s_bal_breaks
);
3095 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
)
3096 trace_ext4_mballoc_alloc(ac
);
3098 trace_ext4_mballoc_prealloc(ac
);
3102 * Called on failure; free up any blocks from the inode PA for this
3103 * context. We don't need this for MB_GROUP_PA because we only change
3104 * pa_free in ext4_mb_release_context(), but on failure, we've already
3105 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3107 static void ext4_discard_allocated_blocks(struct ext4_allocation_context
*ac
)
3109 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
3112 if (pa
&& pa
->pa_type
== MB_INODE_PA
) {
3113 len
= ac
->ac_b_ex
.fe_len
;
3120 * use blocks preallocated to inode
3122 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3123 struct ext4_prealloc_space
*pa
)
3129 /* found preallocated blocks, use them */
3130 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3131 end
= min(pa
->pa_pstart
+ pa
->pa_len
, start
+ ac
->ac_o_ex
.fe_len
);
3133 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3134 &ac
->ac_b_ex
.fe_start
);
3135 ac
->ac_b_ex
.fe_len
= len
;
3136 ac
->ac_status
= AC_STATUS_FOUND
;
3139 BUG_ON(start
< pa
->pa_pstart
);
3140 BUG_ON(start
+ len
> pa
->pa_pstart
+ pa
->pa_len
);
3141 BUG_ON(pa
->pa_free
< len
);
3144 mb_debug(1, "use %llu/%u from inode pa %p\n", start
, len
, pa
);
3148 * use blocks preallocated to locality group
3150 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3151 struct ext4_prealloc_space
*pa
)
3153 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3155 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3156 &ac
->ac_b_ex
.fe_group
,
3157 &ac
->ac_b_ex
.fe_start
);
3158 ac
->ac_b_ex
.fe_len
= len
;
3159 ac
->ac_status
= AC_STATUS_FOUND
;
3162 /* we don't correct pa_pstart or pa_plen here to avoid
3163 * possible race when the group is being loaded concurrently
3164 * instead we correct pa later, after blocks are marked
3165 * in on-disk bitmap -- see ext4_mb_release_context()
3166 * Other CPUs are prevented from allocating from this pa by lg_mutex
3168 mb_debug(1, "use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3172 * Return the prealloc space that have minimal distance
3173 * from the goal block. @cpa is the prealloc
3174 * space that is having currently known minimal distance
3175 * from the goal block.
3177 static struct ext4_prealloc_space
*
3178 ext4_mb_check_group_pa(ext4_fsblk_t goal_block
,
3179 struct ext4_prealloc_space
*pa
,
3180 struct ext4_prealloc_space
*cpa
)
3182 ext4_fsblk_t cur_distance
, new_distance
;
3185 atomic_inc(&pa
->pa_count
);
3188 cur_distance
= abs(goal_block
- cpa
->pa_pstart
);
3189 new_distance
= abs(goal_block
- pa
->pa_pstart
);
3191 if (cur_distance
< new_distance
)
3194 /* drop the previous reference */
3195 atomic_dec(&cpa
->pa_count
);
3196 atomic_inc(&pa
->pa_count
);
3201 * search goal blocks in preallocated space
3203 static noinline_for_stack
int
3204 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3207 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3208 struct ext4_locality_group
*lg
;
3209 struct ext4_prealloc_space
*pa
, *cpa
= NULL
;
3210 ext4_fsblk_t goal_block
;
3212 /* only data can be preallocated */
3213 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3216 /* first, try per-file preallocation */
3218 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3220 /* all fields in this condition don't change,
3221 * so we can skip locking for them */
3222 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3223 ac
->ac_o_ex
.fe_logical
>= pa
->pa_lstart
+ pa
->pa_len
)
3226 /* non-extent files can't have physical blocks past 2^32 */
3227 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)) &&
3228 pa
->pa_pstart
+ pa
->pa_len
> EXT4_MAX_BLOCK_FILE_PHYS
)
3231 /* found preallocated blocks, use them */
3232 spin_lock(&pa
->pa_lock
);
3233 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3234 atomic_inc(&pa
->pa_count
);
3235 ext4_mb_use_inode_pa(ac
, pa
);
3236 spin_unlock(&pa
->pa_lock
);
3237 ac
->ac_criteria
= 10;
3241 spin_unlock(&pa
->pa_lock
);
3245 /* can we use group allocation? */
3246 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3249 /* inode may have no locality group for some reason */
3253 order
= fls(ac
->ac_o_ex
.fe_len
) - 1;
3254 if (order
> PREALLOC_TB_SIZE
- 1)
3255 /* The max size of hash table is PREALLOC_TB_SIZE */
3256 order
= PREALLOC_TB_SIZE
- 1;
3258 goal_block
= ext4_grp_offs_to_block(ac
->ac_sb
, &ac
->ac_g_ex
);
3260 * search for the prealloc space that is having
3261 * minimal distance from the goal block.
3263 for (i
= order
; i
< PREALLOC_TB_SIZE
; i
++) {
3265 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[i
],
3267 spin_lock(&pa
->pa_lock
);
3268 if (pa
->pa_deleted
== 0 &&
3269 pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3271 cpa
= ext4_mb_check_group_pa(goal_block
,
3274 spin_unlock(&pa
->pa_lock
);
3279 ext4_mb_use_group_pa(ac
, cpa
);
3280 ac
->ac_criteria
= 20;
3287 * the function goes through all block freed in the group
3288 * but not yet committed and marks them used in in-core bitmap.
3289 * buddy must be generated from this bitmap
3290 * Need to be called with the ext4 group lock held
3292 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
3296 struct ext4_group_info
*grp
;
3297 struct ext4_free_data
*entry
;
3299 grp
= ext4_get_group_info(sb
, group
);
3300 n
= rb_first(&(grp
->bb_free_root
));
3303 entry
= rb_entry(n
, struct ext4_free_data
, node
);
3304 mb_set_bits(bitmap
, entry
->start_blk
, entry
->count
);
3311 * the function goes through all preallocation in this group and marks them
3312 * used in in-core bitmap. buddy must be generated from this bitmap
3313 * Need to be called with ext4 group lock held
3315 static noinline_for_stack
3316 void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3319 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3320 struct ext4_prealloc_space
*pa
;
3321 struct list_head
*cur
;
3322 ext4_group_t groupnr
;
3323 ext4_grpblk_t start
;
3324 int preallocated
= 0;
3328 /* all form of preallocation discards first load group,
3329 * so the only competing code is preallocation use.
3330 * we don't need any locking here
3331 * notice we do NOT ignore preallocations with pa_deleted
3332 * otherwise we could leave used blocks available for
3333 * allocation in buddy when concurrent ext4_mb_put_pa()
3334 * is dropping preallocation
3336 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3337 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3338 spin_lock(&pa
->pa_lock
);
3339 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3342 spin_unlock(&pa
->pa_lock
);
3343 if (unlikely(len
== 0))
3345 BUG_ON(groupnr
!= group
);
3346 mb_set_bits(bitmap
, start
, len
);
3347 preallocated
+= len
;
3350 mb_debug(1, "prellocated %u for group %u\n", preallocated
, group
);
3353 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3355 struct ext4_prealloc_space
*pa
;
3356 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3357 kmem_cache_free(ext4_pspace_cachep
, pa
);
3361 * drops a reference to preallocated space descriptor
3362 * if this was the last reference and the space is consumed
3364 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3365 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3368 ext4_fsblk_t grp_blk
;
3370 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0)
3373 /* in this short window concurrent discard can set pa_deleted */
3374 spin_lock(&pa
->pa_lock
);
3375 if (pa
->pa_deleted
== 1) {
3376 spin_unlock(&pa
->pa_lock
);
3381 spin_unlock(&pa
->pa_lock
);
3383 grp_blk
= pa
->pa_pstart
;
3385 * If doing group-based preallocation, pa_pstart may be in the
3386 * next group when pa is used up
3388 if (pa
->pa_type
== MB_GROUP_PA
)
3391 ext4_get_group_no_and_offset(sb
, grp_blk
, &grp
, NULL
);
3396 * P1 (buddy init) P2 (regular allocation)
3397 * find block B in PA
3398 * copy on-disk bitmap to buddy
3399 * mark B in on-disk bitmap
3400 * drop PA from group
3401 * mark all PAs in buddy
3403 * thus, P1 initializes buddy with B available. to prevent this
3404 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3407 ext4_lock_group(sb
, grp
);
3408 list_del(&pa
->pa_group_list
);
3409 ext4_unlock_group(sb
, grp
);
3411 spin_lock(pa
->pa_obj_lock
);
3412 list_del_rcu(&pa
->pa_inode_list
);
3413 spin_unlock(pa
->pa_obj_lock
);
3415 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3419 * creates new preallocated space for given inode
3421 static noinline_for_stack
int
3422 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3424 struct super_block
*sb
= ac
->ac_sb
;
3425 struct ext4_prealloc_space
*pa
;
3426 struct ext4_group_info
*grp
;
3427 struct ext4_inode_info
*ei
;
3429 /* preallocate only when found space is larger then requested */
3430 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3431 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3432 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3434 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3438 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3444 /* we can't allocate as much as normalizer wants.
3445 * so, found space must get proper lstart
3446 * to cover original request */
3447 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3448 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3450 /* we're limited by original request in that
3451 * logical block must be covered any way
3452 * winl is window we can move our chunk within */
3453 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3455 /* also, we should cover whole original request */
3456 wins
= ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
;
3458 /* the smallest one defines real window */
3459 win
= min(winl
, wins
);
3461 offs
= ac
->ac_o_ex
.fe_logical
% ac
->ac_b_ex
.fe_len
;
3462 if (offs
&& offs
< win
)
3465 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
- win
;
3466 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3467 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3470 /* preallocation can change ac_b_ex, thus we store actually
3471 * allocated blocks for history */
3472 ac
->ac_f_ex
= ac
->ac_b_ex
;
3474 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3475 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3476 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3477 pa
->pa_free
= pa
->pa_len
;
3478 atomic_set(&pa
->pa_count
, 1);
3479 spin_lock_init(&pa
->pa_lock
);
3480 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3481 INIT_LIST_HEAD(&pa
->pa_group_list
);
3483 pa
->pa_type
= MB_INODE_PA
;
3485 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa
,
3486 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3487 trace_ext4_mb_new_inode_pa(ac
, pa
);
3489 ext4_mb_use_inode_pa(ac
, pa
);
3490 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3492 ei
= EXT4_I(ac
->ac_inode
);
3493 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3495 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3496 pa
->pa_inode
= ac
->ac_inode
;
3498 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3499 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3500 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3502 spin_lock(pa
->pa_obj_lock
);
3503 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3504 spin_unlock(pa
->pa_obj_lock
);
3510 * creates new preallocated space for locality group inodes belongs to
3512 static noinline_for_stack
int
3513 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3515 struct super_block
*sb
= ac
->ac_sb
;
3516 struct ext4_locality_group
*lg
;
3517 struct ext4_prealloc_space
*pa
;
3518 struct ext4_group_info
*grp
;
3520 /* preallocate only when found space is larger then requested */
3521 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3522 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3523 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3525 BUG_ON(ext4_pspace_cachep
== NULL
);
3526 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3530 /* preallocation can change ac_b_ex, thus we store actually
3531 * allocated blocks for history */
3532 ac
->ac_f_ex
= ac
->ac_b_ex
;
3534 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3535 pa
->pa_lstart
= pa
->pa_pstart
;
3536 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3537 pa
->pa_free
= pa
->pa_len
;
3538 atomic_set(&pa
->pa_count
, 1);
3539 spin_lock_init(&pa
->pa_lock
);
3540 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3541 INIT_LIST_HEAD(&pa
->pa_group_list
);
3543 pa
->pa_type
= MB_GROUP_PA
;
3545 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa
,
3546 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3547 trace_ext4_mb_new_group_pa(ac
, pa
);
3549 ext4_mb_use_group_pa(ac
, pa
);
3550 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3552 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3556 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3557 pa
->pa_inode
= NULL
;
3559 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3560 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3561 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3564 * We will later add the new pa to the right bucket
3565 * after updating the pa_free in ext4_mb_release_context
3570 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3574 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3575 err
= ext4_mb_new_group_pa(ac
);
3577 err
= ext4_mb_new_inode_pa(ac
);
3582 * finds all unused blocks in on-disk bitmap, frees them in
3583 * in-core bitmap and buddy.
3584 * @pa must be unlinked from inode and group lists, so that
3585 * nobody else can find/use it.
3586 * the caller MUST hold group/inode locks.
3587 * TODO: optimize the case when there are no in-core structures yet
3589 static noinline_for_stack
int
3590 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3591 struct ext4_prealloc_space
*pa
)
3593 struct super_block
*sb
= e4b
->bd_sb
;
3594 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3599 unsigned long long grp_blk_start
;
3603 BUG_ON(pa
->pa_deleted
== 0);
3604 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3605 grp_blk_start
= pa
->pa_pstart
- bit
;
3606 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3607 end
= bit
+ pa
->pa_len
;
3610 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3613 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3614 mb_debug(1, " free preallocated %u/%u in group %u\n",
3615 (unsigned) ext4_group_first_block_no(sb
, group
) + bit
,
3616 (unsigned) next
- bit
, (unsigned) group
);
3619 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, next
- bit
);
3620 trace_ext4_mb_release_inode_pa(sb
, pa
->pa_inode
, pa
,
3621 grp_blk_start
+ bit
, next
- bit
);
3622 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3625 if (free
!= pa
->pa_free
) {
3626 printk(KERN_CRIT
"pa %p: logic %lu, phys. %lu, len %lu\n",
3627 pa
, (unsigned long) pa
->pa_lstart
,
3628 (unsigned long) pa
->pa_pstart
,
3629 (unsigned long) pa
->pa_len
);
3630 ext4_grp_locked_error(sb
, group
, 0, 0, "free %u, pa_free %u",
3633 * pa is already deleted so we use the value obtained
3634 * from the bitmap and continue.
3637 atomic_add(free
, &sbi
->s_mb_discarded
);
3642 static noinline_for_stack
int
3643 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3644 struct ext4_prealloc_space
*pa
)
3646 struct super_block
*sb
= e4b
->bd_sb
;
3650 trace_ext4_mb_release_group_pa(sb
, pa
);
3651 BUG_ON(pa
->pa_deleted
== 0);
3652 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3653 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3654 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3655 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3656 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, pa
->pa_len
);
3662 * releases all preallocations in given group
3664 * first, we need to decide discard policy:
3665 * - when do we discard
3667 * - how many do we discard
3668 * 1) how many requested
3670 static noinline_for_stack
int
3671 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3672 ext4_group_t group
, int needed
)
3674 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3675 struct buffer_head
*bitmap_bh
= NULL
;
3676 struct ext4_prealloc_space
*pa
, *tmp
;
3677 struct list_head list
;
3678 struct ext4_buddy e4b
;
3683 mb_debug(1, "discard preallocation for group %u\n", group
);
3685 if (list_empty(&grp
->bb_prealloc_list
))
3688 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3689 if (bitmap_bh
== NULL
) {
3690 ext4_error(sb
, "Error reading block bitmap for %u", group
);
3694 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3696 ext4_error(sb
, "Error loading buddy information for %u", group
);
3702 needed
= EXT4_BLOCKS_PER_GROUP(sb
) + 1;
3704 INIT_LIST_HEAD(&list
);
3706 ext4_lock_group(sb
, group
);
3707 list_for_each_entry_safe(pa
, tmp
,
3708 &grp
->bb_prealloc_list
, pa_group_list
) {
3709 spin_lock(&pa
->pa_lock
);
3710 if (atomic_read(&pa
->pa_count
)) {
3711 spin_unlock(&pa
->pa_lock
);
3715 if (pa
->pa_deleted
) {
3716 spin_unlock(&pa
->pa_lock
);
3720 /* seems this one can be freed ... */
3723 /* we can trust pa_free ... */
3724 free
+= pa
->pa_free
;
3726 spin_unlock(&pa
->pa_lock
);
3728 list_del(&pa
->pa_group_list
);
3729 list_add(&pa
->u
.pa_tmp_list
, &list
);
3732 /* if we still need more blocks and some PAs were used, try again */
3733 if (free
< needed
&& busy
) {
3735 ext4_unlock_group(sb
, group
);
3737 * Yield the CPU here so that we don't get soft lockup
3738 * in non preempt case.
3744 /* found anything to free? */
3745 if (list_empty(&list
)) {
3750 /* now free all selected PAs */
3751 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3753 /* remove from object (inode or locality group) */
3754 spin_lock(pa
->pa_obj_lock
);
3755 list_del_rcu(&pa
->pa_inode_list
);
3756 spin_unlock(pa
->pa_obj_lock
);
3758 if (pa
->pa_type
== MB_GROUP_PA
)
3759 ext4_mb_release_group_pa(&e4b
, pa
);
3761 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3763 list_del(&pa
->u
.pa_tmp_list
);
3764 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3768 ext4_unlock_group(sb
, group
);
3769 ext4_mb_unload_buddy(&e4b
);
3775 * releases all non-used preallocated blocks for given inode
3777 * It's important to discard preallocations under i_data_sem
3778 * We don't want another block to be served from the prealloc
3779 * space when we are discarding the inode prealloc space.
3781 * FIXME!! Make sure it is valid at all the call sites
3783 void ext4_discard_preallocations(struct inode
*inode
)
3785 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3786 struct super_block
*sb
= inode
->i_sb
;
3787 struct buffer_head
*bitmap_bh
= NULL
;
3788 struct ext4_prealloc_space
*pa
, *tmp
;
3789 ext4_group_t group
= 0;
3790 struct list_head list
;
3791 struct ext4_buddy e4b
;
3794 if (!S_ISREG(inode
->i_mode
)) {
3795 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3799 mb_debug(1, "discard preallocation for inode %lu\n", inode
->i_ino
);
3800 trace_ext4_discard_preallocations(inode
);
3802 INIT_LIST_HEAD(&list
);
3805 /* first, collect all pa's in the inode */
3806 spin_lock(&ei
->i_prealloc_lock
);
3807 while (!list_empty(&ei
->i_prealloc_list
)) {
3808 pa
= list_entry(ei
->i_prealloc_list
.next
,
3809 struct ext4_prealloc_space
, pa_inode_list
);
3810 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3811 spin_lock(&pa
->pa_lock
);
3812 if (atomic_read(&pa
->pa_count
)) {
3813 /* this shouldn't happen often - nobody should
3814 * use preallocation while we're discarding it */
3815 spin_unlock(&pa
->pa_lock
);
3816 spin_unlock(&ei
->i_prealloc_lock
);
3817 printk(KERN_ERR
"uh-oh! used pa while discarding\n");
3819 schedule_timeout_uninterruptible(HZ
);
3823 if (pa
->pa_deleted
== 0) {
3825 spin_unlock(&pa
->pa_lock
);
3826 list_del_rcu(&pa
->pa_inode_list
);
3827 list_add(&pa
->u
.pa_tmp_list
, &list
);
3831 /* someone is deleting pa right now */
3832 spin_unlock(&pa
->pa_lock
);
3833 spin_unlock(&ei
->i_prealloc_lock
);
3835 /* we have to wait here because pa_deleted
3836 * doesn't mean pa is already unlinked from
3837 * the list. as we might be called from
3838 * ->clear_inode() the inode will get freed
3839 * and concurrent thread which is unlinking
3840 * pa from inode's list may access already
3841 * freed memory, bad-bad-bad */
3843 /* XXX: if this happens too often, we can
3844 * add a flag to force wait only in case
3845 * of ->clear_inode(), but not in case of
3846 * regular truncate */
3847 schedule_timeout_uninterruptible(HZ
);
3850 spin_unlock(&ei
->i_prealloc_lock
);
3852 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3853 BUG_ON(pa
->pa_type
!= MB_INODE_PA
);
3854 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
3856 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3858 ext4_error(sb
, "Error loading buddy information for %u",
3863 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3864 if (bitmap_bh
== NULL
) {
3865 ext4_error(sb
, "Error reading block bitmap for %u",
3867 ext4_mb_unload_buddy(&e4b
);
3871 ext4_lock_group(sb
, group
);
3872 list_del(&pa
->pa_group_list
);
3873 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3874 ext4_unlock_group(sb
, group
);
3876 ext4_mb_unload_buddy(&e4b
);
3879 list_del(&pa
->u
.pa_tmp_list
);
3880 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3885 * finds all preallocated spaces and return blocks being freed to them
3886 * if preallocated space becomes full (no block is used from the space)
3887 * then the function frees space in buddy
3888 * XXX: at the moment, truncate (which is the only way to free blocks)
3889 * discards all preallocations
3891 static void ext4_mb_return_to_preallocation(struct inode
*inode
,
3892 struct ext4_buddy
*e4b
,
3893 sector_t block
, int count
)
3895 BUG_ON(!list_empty(&EXT4_I(inode
)->i_prealloc_list
));
3897 #ifdef CONFIG_EXT4_DEBUG
3898 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3900 struct super_block
*sb
= ac
->ac_sb
;
3901 ext4_group_t ngroups
, i
;
3903 if (EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
)
3906 printk(KERN_ERR
"EXT4-fs: Can't allocate:"
3907 " Allocation context details:\n");
3908 printk(KERN_ERR
"EXT4-fs: status %d flags %d\n",
3909 ac
->ac_status
, ac
->ac_flags
);
3910 printk(KERN_ERR
"EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
3911 "best %lu/%lu/%lu@%lu cr %d\n",
3912 (unsigned long)ac
->ac_o_ex
.fe_group
,
3913 (unsigned long)ac
->ac_o_ex
.fe_start
,
3914 (unsigned long)ac
->ac_o_ex
.fe_len
,
3915 (unsigned long)ac
->ac_o_ex
.fe_logical
,
3916 (unsigned long)ac
->ac_g_ex
.fe_group
,
3917 (unsigned long)ac
->ac_g_ex
.fe_start
,
3918 (unsigned long)ac
->ac_g_ex
.fe_len
,
3919 (unsigned long)ac
->ac_g_ex
.fe_logical
,
3920 (unsigned long)ac
->ac_b_ex
.fe_group
,
3921 (unsigned long)ac
->ac_b_ex
.fe_start
,
3922 (unsigned long)ac
->ac_b_ex
.fe_len
,
3923 (unsigned long)ac
->ac_b_ex
.fe_logical
,
3924 (int)ac
->ac_criteria
);
3925 printk(KERN_ERR
"EXT4-fs: %lu scanned, %d found\n", ac
->ac_ex_scanned
,
3927 printk(KERN_ERR
"EXT4-fs: groups: \n");
3928 ngroups
= ext4_get_groups_count(sb
);
3929 for (i
= 0; i
< ngroups
; i
++) {
3930 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
3931 struct ext4_prealloc_space
*pa
;
3932 ext4_grpblk_t start
;
3933 struct list_head
*cur
;
3934 ext4_lock_group(sb
, i
);
3935 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3936 pa
= list_entry(cur
, struct ext4_prealloc_space
,
3938 spin_lock(&pa
->pa_lock
);
3939 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3941 spin_unlock(&pa
->pa_lock
);
3942 printk(KERN_ERR
"PA:%u:%d:%u \n", i
,
3945 ext4_unlock_group(sb
, i
);
3947 if (grp
->bb_free
== 0)
3949 printk(KERN_ERR
"%u: %d/%d \n",
3950 i
, grp
->bb_free
, grp
->bb_fragments
);
3952 printk(KERN_ERR
"\n");
3955 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3962 * We use locality group preallocation for small size file. The size of the
3963 * file is determined by the current size or the resulting size after
3964 * allocation which ever is larger
3966 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
3968 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
3970 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3971 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3974 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3977 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3980 size
= ac
->ac_o_ex
.fe_logical
+ ac
->ac_o_ex
.fe_len
;
3981 isize
= (i_size_read(ac
->ac_inode
) + ac
->ac_sb
->s_blocksize
- 1)
3984 if ((size
== isize
) &&
3985 !ext4_fs_is_busy(sbi
) &&
3986 (atomic_read(&ac
->ac_inode
->i_writecount
) == 0)) {
3987 ac
->ac_flags
|= EXT4_MB_HINT_NOPREALLOC
;
3991 /* don't use group allocation for large files */
3992 size
= max(size
, isize
);
3993 if (size
> sbi
->s_mb_stream_request
) {
3994 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
3998 BUG_ON(ac
->ac_lg
!= NULL
);
4000 * locality group prealloc space are per cpu. The reason for having
4001 * per cpu locality group is to reduce the contention between block
4002 * request from multiple CPUs.
4004 ac
->ac_lg
= __this_cpu_ptr(sbi
->s_locality_groups
);
4006 /* we're going to use group allocation */
4007 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
4009 /* serialize all allocations in the group */
4010 mutex_lock(&ac
->ac_lg
->lg_mutex
);
4013 static noinline_for_stack
int
4014 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
4015 struct ext4_allocation_request
*ar
)
4017 struct super_block
*sb
= ar
->inode
->i_sb
;
4018 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4019 struct ext4_super_block
*es
= sbi
->s_es
;
4023 ext4_grpblk_t block
;
4025 /* we can't allocate > group size */
4028 /* just a dirty hack to filter too big requests */
4029 if (len
>= EXT4_BLOCKS_PER_GROUP(sb
) - 10)
4030 len
= EXT4_BLOCKS_PER_GROUP(sb
) - 10;
4032 /* start searching from the goal */
4034 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
4035 goal
>= ext4_blocks_count(es
))
4036 goal
= le32_to_cpu(es
->s_first_data_block
);
4037 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
4039 /* set up allocation goals */
4040 memset(ac
, 0, sizeof(struct ext4_allocation_context
));
4041 ac
->ac_b_ex
.fe_logical
= ar
->logical
;
4042 ac
->ac_status
= AC_STATUS_CONTINUE
;
4044 ac
->ac_inode
= ar
->inode
;
4045 ac
->ac_o_ex
.fe_logical
= ar
->logical
;
4046 ac
->ac_o_ex
.fe_group
= group
;
4047 ac
->ac_o_ex
.fe_start
= block
;
4048 ac
->ac_o_ex
.fe_len
= len
;
4049 ac
->ac_g_ex
.fe_logical
= ar
->logical
;
4050 ac
->ac_g_ex
.fe_group
= group
;
4051 ac
->ac_g_ex
.fe_start
= block
;
4052 ac
->ac_g_ex
.fe_len
= len
;
4053 ac
->ac_flags
= ar
->flags
;
4055 /* we have to define context: we'll we work with a file or
4056 * locality group. this is a policy, actually */
4057 ext4_mb_group_or_file(ac
);
4059 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4060 "left: %u/%u, right %u/%u to %swritable\n",
4061 (unsigned) ar
->len
, (unsigned) ar
->logical
,
4062 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
4063 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
4064 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
4065 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
4070 static noinline_for_stack
void
4071 ext4_mb_discard_lg_preallocations(struct super_block
*sb
,
4072 struct ext4_locality_group
*lg
,
4073 int order
, int total_entries
)
4075 ext4_group_t group
= 0;
4076 struct ext4_buddy e4b
;
4077 struct list_head discard_list
;
4078 struct ext4_prealloc_space
*pa
, *tmp
;
4080 mb_debug(1, "discard locality group preallocation\n");
4082 INIT_LIST_HEAD(&discard_list
);
4084 spin_lock(&lg
->lg_prealloc_lock
);
4085 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[order
],
4087 spin_lock(&pa
->pa_lock
);
4088 if (atomic_read(&pa
->pa_count
)) {
4090 * This is the pa that we just used
4091 * for block allocation. So don't
4094 spin_unlock(&pa
->pa_lock
);
4097 if (pa
->pa_deleted
) {
4098 spin_unlock(&pa
->pa_lock
);
4101 /* only lg prealloc space */
4102 BUG_ON(pa
->pa_type
!= MB_GROUP_PA
);
4104 /* seems this one can be freed ... */
4106 spin_unlock(&pa
->pa_lock
);
4108 list_del_rcu(&pa
->pa_inode_list
);
4109 list_add(&pa
->u
.pa_tmp_list
, &discard_list
);
4112 if (total_entries
<= 5) {
4114 * we want to keep only 5 entries
4115 * allowing it to grow to 8. This
4116 * mak sure we don't call discard
4117 * soon for this list.
4122 spin_unlock(&lg
->lg_prealloc_lock
);
4124 list_for_each_entry_safe(pa
, tmp
, &discard_list
, u
.pa_tmp_list
) {
4126 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
4127 if (ext4_mb_load_buddy(sb
, group
, &e4b
)) {
4128 ext4_error(sb
, "Error loading buddy information for %u",
4132 ext4_lock_group(sb
, group
);
4133 list_del(&pa
->pa_group_list
);
4134 ext4_mb_release_group_pa(&e4b
, pa
);
4135 ext4_unlock_group(sb
, group
);
4137 ext4_mb_unload_buddy(&e4b
);
4138 list_del(&pa
->u
.pa_tmp_list
);
4139 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4144 * We have incremented pa_count. So it cannot be freed at this
4145 * point. Also we hold lg_mutex. So no parallel allocation is
4146 * possible from this lg. That means pa_free cannot be updated.
4148 * A parallel ext4_mb_discard_group_preallocations is possible.
4149 * which can cause the lg_prealloc_list to be updated.
4152 static void ext4_mb_add_n_trim(struct ext4_allocation_context
*ac
)
4154 int order
, added
= 0, lg_prealloc_count
= 1;
4155 struct super_block
*sb
= ac
->ac_sb
;
4156 struct ext4_locality_group
*lg
= ac
->ac_lg
;
4157 struct ext4_prealloc_space
*tmp_pa
, *pa
= ac
->ac_pa
;
4159 order
= fls(pa
->pa_free
) - 1;
4160 if (order
> PREALLOC_TB_SIZE
- 1)
4161 /* The max size of hash table is PREALLOC_TB_SIZE */
4162 order
= PREALLOC_TB_SIZE
- 1;
4163 /* Add the prealloc space to lg */
4165 list_for_each_entry_rcu(tmp_pa
, &lg
->lg_prealloc_list
[order
],
4167 spin_lock(&tmp_pa
->pa_lock
);
4168 if (tmp_pa
->pa_deleted
) {
4169 spin_unlock(&tmp_pa
->pa_lock
);
4172 if (!added
&& pa
->pa_free
< tmp_pa
->pa_free
) {
4173 /* Add to the tail of the previous entry */
4174 list_add_tail_rcu(&pa
->pa_inode_list
,
4175 &tmp_pa
->pa_inode_list
);
4178 * we want to count the total
4179 * number of entries in the list
4182 spin_unlock(&tmp_pa
->pa_lock
);
4183 lg_prealloc_count
++;
4186 list_add_tail_rcu(&pa
->pa_inode_list
,
4187 &lg
->lg_prealloc_list
[order
]);
4190 /* Now trim the list to be not more than 8 elements */
4191 if (lg_prealloc_count
> 8) {
4192 ext4_mb_discard_lg_preallocations(sb
, lg
,
4193 order
, lg_prealloc_count
);
4200 * release all resource we used in allocation
4202 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
4204 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
4206 if (pa
->pa_type
== MB_GROUP_PA
) {
4207 /* see comment in ext4_mb_use_group_pa() */
4208 spin_lock(&pa
->pa_lock
);
4209 pa
->pa_pstart
+= ac
->ac_b_ex
.fe_len
;
4210 pa
->pa_lstart
+= ac
->ac_b_ex
.fe_len
;
4211 pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
4212 pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
4213 spin_unlock(&pa
->pa_lock
);
4217 up_read(ac
->alloc_semp
);
4220 * We want to add the pa to the right bucket.
4221 * Remove it from the list and while adding
4222 * make sure the list to which we are adding
4223 * doesn't grow big. We need to release
4224 * alloc_semp before calling ext4_mb_add_n_trim()
4226 if ((pa
->pa_type
== MB_GROUP_PA
) && likely(pa
->pa_free
)) {
4227 spin_lock(pa
->pa_obj_lock
);
4228 list_del_rcu(&pa
->pa_inode_list
);
4229 spin_unlock(pa
->pa_obj_lock
);
4230 ext4_mb_add_n_trim(ac
);
4232 ext4_mb_put_pa(ac
, ac
->ac_sb
, pa
);
4234 if (ac
->ac_bitmap_page
)
4235 page_cache_release(ac
->ac_bitmap_page
);
4236 if (ac
->ac_buddy_page
)
4237 page_cache_release(ac
->ac_buddy_page
);
4238 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
4239 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
4240 ext4_mb_collect_stats(ac
);
4244 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
4246 ext4_group_t i
, ngroups
= ext4_get_groups_count(sb
);
4250 trace_ext4_mb_discard_preallocations(sb
, needed
);
4251 for (i
= 0; i
< ngroups
&& needed
> 0; i
++) {
4252 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4261 * Main entry point into mballoc to allocate blocks
4262 * it tries to use preallocation first, then falls back
4263 * to usual allocation
4265 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4266 struct ext4_allocation_request
*ar
, int *errp
)
4269 struct ext4_allocation_context
*ac
= NULL
;
4270 struct ext4_sb_info
*sbi
;
4271 struct super_block
*sb
;
4272 ext4_fsblk_t block
= 0;
4273 unsigned int inquota
= 0;
4274 unsigned int reserv_blks
= 0;
4276 sb
= ar
->inode
->i_sb
;
4279 trace_ext4_request_blocks(ar
);
4282 * For delayed allocation, we could skip the ENOSPC and
4283 * EDQUOT check, as blocks and quotas have been already
4284 * reserved when data being copied into pagecache.
4286 if (EXT4_I(ar
->inode
)->i_delalloc_reserved_flag
)
4287 ar
->flags
|= EXT4_MB_DELALLOC_RESERVED
;
4289 /* Without delayed allocation we need to verify
4290 * there is enough free blocks to do block allocation
4291 * and verify allocation doesn't exceed the quota limits.
4293 while (ar
->len
&& ext4_claim_free_blocks(sbi
, ar
->len
)) {
4294 /* let others to free the space */
4296 ar
->len
= ar
->len
>> 1;
4302 reserv_blks
= ar
->len
;
4303 while (ar
->len
&& dquot_alloc_block(ar
->inode
, ar
->len
)) {
4304 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4314 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4321 *errp
= ext4_mb_initialize_context(ac
, ar
);
4327 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4328 if (!ext4_mb_use_preallocated(ac
)) {
4329 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4330 ext4_mb_normalize_request(ac
, ar
);
4332 /* allocate space in core */
4333 *errp
= ext4_mb_regular_allocator(ac
);
4337 /* as we've just preallocated more space than
4338 * user requested orinally, we store allocated
4339 * space in a special descriptor */
4340 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4341 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4342 ext4_mb_new_preallocation(ac
);
4344 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4345 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
, reserv_blks
);
4346 if (*errp
== -EAGAIN
) {
4348 * drop the reference that we took
4349 * in ext4_mb_use_best_found
4351 ext4_mb_release_context(ac
);
4352 ac
->ac_b_ex
.fe_group
= 0;
4353 ac
->ac_b_ex
.fe_start
= 0;
4354 ac
->ac_b_ex
.fe_len
= 0;
4355 ac
->ac_status
= AC_STATUS_CONTINUE
;
4359 ext4_discard_allocated_blocks(ac
);
4361 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4362 ar
->len
= ac
->ac_b_ex
.fe_len
;
4365 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4372 ac
->ac_b_ex
.fe_len
= 0;
4374 ext4_mb_show_ac(ac
);
4376 ext4_mb_release_context(ac
);
4379 kmem_cache_free(ext4_ac_cachep
, ac
);
4380 if (inquota
&& ar
->len
< inquota
)
4381 dquot_free_block(ar
->inode
, inquota
- ar
->len
);
4383 if (!EXT4_I(ar
->inode
)->i_delalloc_reserved_flag
)
4384 /* release all the reserved blocks if non delalloc */
4385 percpu_counter_sub(&sbi
->s_dirtyblocks_counter
,
4389 trace_ext4_allocate_blocks(ar
, (unsigned long long)block
);
4395 * We can merge two free data extents only if the physical blocks
4396 * are contiguous, AND the extents were freed by the same transaction,
4397 * AND the blocks are associated with the same group.
4399 static int can_merge(struct ext4_free_data
*entry1
,
4400 struct ext4_free_data
*entry2
)
4402 if ((entry1
->t_tid
== entry2
->t_tid
) &&
4403 (entry1
->group
== entry2
->group
) &&
4404 ((entry1
->start_blk
+ entry1
->count
) == entry2
->start_blk
))
4409 static noinline_for_stack
int
4410 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4411 struct ext4_free_data
*new_entry
)
4413 ext4_group_t group
= e4b
->bd_group
;
4414 ext4_grpblk_t block
;
4415 struct ext4_free_data
*entry
;
4416 struct ext4_group_info
*db
= e4b
->bd_info
;
4417 struct super_block
*sb
= e4b
->bd_sb
;
4418 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4419 struct rb_node
**n
= &db
->bb_free_root
.rb_node
, *node
;
4420 struct rb_node
*parent
= NULL
, *new_node
;
4422 BUG_ON(!ext4_handle_valid(handle
));
4423 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4424 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4426 new_node
= &new_entry
->node
;
4427 block
= new_entry
->start_blk
;
4430 /* first free block exent. We need to
4431 protect buddy cache from being freed,
4432 * otherwise we'll refresh it from
4433 * on-disk bitmap and lose not-yet-available
4435 page_cache_get(e4b
->bd_buddy_page
);
4436 page_cache_get(e4b
->bd_bitmap_page
);
4440 entry
= rb_entry(parent
, struct ext4_free_data
, node
);
4441 if (block
< entry
->start_blk
)
4443 else if (block
>= (entry
->start_blk
+ entry
->count
))
4444 n
= &(*n
)->rb_right
;
4446 ext4_grp_locked_error(sb
, group
, 0,
4447 ext4_group_first_block_no(sb
, group
) + block
,
4448 "Block already on to-be-freed list");
4453 rb_link_node(new_node
, parent
, n
);
4454 rb_insert_color(new_node
, &db
->bb_free_root
);
4456 /* Now try to see the extent can be merged to left and right */
4457 node
= rb_prev(new_node
);
4459 entry
= rb_entry(node
, struct ext4_free_data
, node
);
4460 if (can_merge(entry
, new_entry
)) {
4461 new_entry
->start_blk
= entry
->start_blk
;
4462 new_entry
->count
+= entry
->count
;
4463 rb_erase(node
, &(db
->bb_free_root
));
4464 spin_lock(&sbi
->s_md_lock
);
4465 list_del(&entry
->list
);
4466 spin_unlock(&sbi
->s_md_lock
);
4467 kmem_cache_free(ext4_free_ext_cachep
, entry
);
4471 node
= rb_next(new_node
);
4473 entry
= rb_entry(node
, struct ext4_free_data
, node
);
4474 if (can_merge(new_entry
, entry
)) {
4475 new_entry
->count
+= entry
->count
;
4476 rb_erase(node
, &(db
->bb_free_root
));
4477 spin_lock(&sbi
->s_md_lock
);
4478 list_del(&entry
->list
);
4479 spin_unlock(&sbi
->s_md_lock
);
4480 kmem_cache_free(ext4_free_ext_cachep
, entry
);
4483 /* Add the extent to transaction's private list */
4484 spin_lock(&sbi
->s_md_lock
);
4485 list_add(&new_entry
->list
, &handle
->h_transaction
->t_private_list
);
4486 spin_unlock(&sbi
->s_md_lock
);
4491 * ext4_free_blocks() -- Free given blocks and update quota
4492 * @handle: handle for this transaction
4494 * @block: start physical block to free
4495 * @count: number of blocks to count
4496 * @metadata: Are these metadata blocks
4498 void ext4_free_blocks(handle_t
*handle
, struct inode
*inode
,
4499 struct buffer_head
*bh
, ext4_fsblk_t block
,
4500 unsigned long count
, int flags
)
4502 struct buffer_head
*bitmap_bh
= NULL
;
4503 struct super_block
*sb
= inode
->i_sb
;
4504 struct ext4_group_desc
*gdp
;
4505 unsigned long freed
= 0;
4506 unsigned int overflow
;
4508 struct buffer_head
*gd_bh
;
4509 ext4_group_t block_group
;
4510 struct ext4_sb_info
*sbi
;
4511 struct ext4_buddy e4b
;
4517 BUG_ON(block
!= bh
->b_blocknr
);
4519 block
= bh
->b_blocknr
;
4523 if (!(flags
& EXT4_FREE_BLOCKS_VALIDATED
) &&
4524 !ext4_data_block_valid(sbi
, block
, count
)) {
4525 ext4_error(sb
, "Freeing blocks not in datazone - "
4526 "block = %llu, count = %lu", block
, count
);
4530 ext4_debug("freeing block %llu\n", block
);
4531 trace_ext4_free_blocks(inode
, block
, count
, flags
);
4533 if (flags
& EXT4_FREE_BLOCKS_FORGET
) {
4534 struct buffer_head
*tbh
= bh
;
4537 BUG_ON(bh
&& (count
> 1));
4539 for (i
= 0; i
< count
; i
++) {
4541 tbh
= sb_find_get_block(inode
->i_sb
,
4545 ext4_forget(handle
, flags
& EXT4_FREE_BLOCKS_METADATA
,
4546 inode
, tbh
, block
+ i
);
4551 * We need to make sure we don't reuse the freed block until
4552 * after the transaction is committed, which we can do by
4553 * treating the block as metadata, below. We make an
4554 * exception if the inode is to be written in writeback mode
4555 * since writeback mode has weak data consistency guarantees.
4557 if (!ext4_should_writeback_data(inode
))
4558 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4562 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4565 * Check to see if we are freeing blocks across a group
4568 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4569 overflow
= bit
+ count
- EXT4_BLOCKS_PER_GROUP(sb
);
4572 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4577 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4583 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4584 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4585 in_range(block
, ext4_inode_table(sb
, gdp
),
4586 EXT4_SB(sb
)->s_itb_per_group
) ||
4587 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4588 EXT4_SB(sb
)->s_itb_per_group
)) {
4590 ext4_error(sb
, "Freeing blocks in system zone - "
4591 "Block = %llu, count = %lu", block
, count
);
4592 /* err = 0. ext4_std_error should be a no op */
4596 BUFFER_TRACE(bitmap_bh
, "getting write access");
4597 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4602 * We are about to modify some metadata. Call the journal APIs
4603 * to unshare ->b_data if a currently-committing transaction is
4606 BUFFER_TRACE(gd_bh
, "get_write_access");
4607 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4610 #ifdef AGGRESSIVE_CHECK
4613 for (i
= 0; i
< count
; i
++)
4614 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4617 trace_ext4_mballoc_free(sb
, inode
, block_group
, bit
, count
);
4619 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4623 if ((flags
& EXT4_FREE_BLOCKS_METADATA
) && ext4_handle_valid(handle
)) {
4624 struct ext4_free_data
*new_entry
;
4626 * blocks being freed are metadata. these blocks shouldn't
4627 * be used until this transaction is committed
4629 new_entry
= kmem_cache_alloc(ext4_free_ext_cachep
, GFP_NOFS
);
4630 new_entry
->start_blk
= bit
;
4631 new_entry
->group
= block_group
;
4632 new_entry
->count
= count
;
4633 new_entry
->t_tid
= handle
->h_transaction
->t_tid
;
4635 ext4_lock_group(sb
, block_group
);
4636 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4637 ext4_mb_free_metadata(handle
, &e4b
, new_entry
);
4639 /* need to update group_info->bb_free and bitmap
4640 * with group lock held. generate_buddy look at
4641 * them with group lock_held
4643 ext4_lock_group(sb
, block_group
);
4644 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4645 mb_free_blocks(inode
, &e4b
, bit
, count
);
4646 ext4_mb_return_to_preallocation(inode
, &e4b
, block
, count
);
4649 ret
= ext4_free_blks_count(sb
, gdp
) + count
;
4650 ext4_free_blks_set(sb
, gdp
, ret
);
4651 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, block_group
, gdp
);
4652 ext4_unlock_group(sb
, block_group
);
4653 percpu_counter_add(&sbi
->s_freeblocks_counter
, count
);
4655 if (sbi
->s_log_groups_per_flex
) {
4656 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4657 atomic_add(count
, &sbi
->s_flex_groups
[flex_group
].free_blocks
);
4660 ext4_mb_unload_buddy(&e4b
);
4664 /* We dirtied the bitmap block */
4665 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4666 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4668 /* And the group descriptor block */
4669 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4670 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4674 if (overflow
&& !err
) {
4680 ext4_mark_super_dirty(sb
);
4683 dquot_free_block(inode
, freed
);
4685 ext4_std_error(sb
, err
);
4690 * ext4_trim_extent -- function to TRIM one single free extent in the group
4691 * @sb: super block for the file system
4692 * @start: starting block of the free extent in the alloc. group
4693 * @count: number of blocks to TRIM
4694 * @group: alloc. group we are working with
4695 * @e4b: ext4 buddy for the group
4697 * Trim "count" blocks starting at "start" in the "group". To assure that no
4698 * one will allocate those blocks, mark it as used in buddy bitmap. This must
4699 * be called with under the group lock.
4701 static int ext4_trim_extent(struct super_block
*sb
, int start
, int count
,
4702 ext4_group_t group
, struct ext4_buddy
*e4b
)
4704 struct ext4_free_extent ex
;
4707 assert_spin_locked(ext4_group_lock_ptr(sb
, group
));
4709 ex
.fe_start
= start
;
4710 ex
.fe_group
= group
;
4714 * Mark blocks used, so no one can reuse them while
4717 mb_mark_used(e4b
, &ex
);
4718 ext4_unlock_group(sb
, group
);
4720 ret
= ext4_issue_discard(sb
, group
, start
, count
);
4722 ext4_std_error(sb
, ret
);
4724 ext4_lock_group(sb
, group
);
4725 mb_free_blocks(NULL
, e4b
, start
, ex
.fe_len
);
4730 * ext4_trim_all_free -- function to trim all free space in alloc. group
4731 * @sb: super block for file system
4733 * @start: first group block to examine
4734 * @max: last group block to examine
4735 * @minblocks: minimum extent block count
4737 * ext4_trim_all_free walks through group's buddy bitmap searching for free
4738 * extents. When the free block is found, ext4_trim_extent is called to TRIM
4742 * ext4_trim_all_free walks through group's block bitmap searching for free
4743 * extents. When the free extent is found, mark it as used in group buddy
4744 * bitmap. Then issue a TRIM command on this extent and free the extent in
4745 * the group buddy bitmap. This is done until whole group is scanned.
4747 ext4_grpblk_t
ext4_trim_all_free(struct super_block
*sb
, struct ext4_buddy
*e4b
,
4748 ext4_grpblk_t start
, ext4_grpblk_t max
, ext4_grpblk_t minblocks
)
4751 ext4_grpblk_t next
, count
= 0;
4755 BUG_ON(e4b
== NULL
);
4757 bitmap
= e4b
->bd_bitmap
;
4758 group
= e4b
->bd_group
;
4759 start
= (e4b
->bd_info
->bb_first_free
> start
) ?
4760 e4b
->bd_info
->bb_first_free
: start
;
4761 ext4_lock_group(sb
, group
);
4763 while (start
< max
) {
4764 start
= mb_find_next_zero_bit(bitmap
, max
, start
);
4767 next
= mb_find_next_bit(bitmap
, max
, start
);
4769 if ((next
- start
) >= minblocks
) {
4770 ret
= ext4_trim_extent(sb
, start
,
4771 next
- start
, group
, e4b
);
4774 count
+= next
- start
;
4778 if (fatal_signal_pending(current
)) {
4779 count
= -ERESTARTSYS
;
4783 if (need_resched()) {
4784 ext4_unlock_group(sb
, group
);
4786 ext4_lock_group(sb
, group
);
4789 if ((e4b
->bd_info
->bb_free
- count
) < minblocks
)
4792 ext4_unlock_group(sb
, group
);
4794 ext4_debug("trimmed %d blocks in the group %d\n",
4804 * ext4_trim_fs() -- trim ioctl handle function
4805 * @sb: superblock for filesystem
4806 * @range: fstrim_range structure
4808 * start: First Byte to trim
4809 * len: number of Bytes to trim from start
4810 * minlen: minimum extent length in Bytes
4811 * ext4_trim_fs goes through all allocation groups containing Bytes from
4812 * start to start+len. For each such a group ext4_trim_all_free function
4813 * is invoked to trim all free space.
4815 int ext4_trim_fs(struct super_block
*sb
, struct fstrim_range
*range
)
4817 struct ext4_buddy e4b
;
4818 ext4_group_t first_group
, last_group
;
4819 ext4_group_t group
, ngroups
= ext4_get_groups_count(sb
);
4820 ext4_grpblk_t cnt
= 0, first_block
, last_block
;
4821 uint64_t start
, len
, minlen
, trimmed
;
4824 start
= range
->start
>> sb
->s_blocksize_bits
;
4825 len
= range
->len
>> sb
->s_blocksize_bits
;
4826 minlen
= range
->minlen
>> sb
->s_blocksize_bits
;
4829 if (unlikely(minlen
> EXT4_BLOCKS_PER_GROUP(sb
)))
4832 /* Determine first and last group to examine based on start and len */
4833 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) start
,
4834 &first_group
, &first_block
);
4835 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) (start
+ len
),
4836 &last_group
, &last_block
);
4837 last_group
= (last_group
> ngroups
- 1) ? ngroups
- 1 : last_group
;
4838 last_block
= EXT4_BLOCKS_PER_GROUP(sb
);
4840 if (first_group
> last_group
)
4843 for (group
= first_group
; group
<= last_group
; group
++) {
4844 ret
= ext4_mb_load_buddy(sb
, group
, &e4b
);
4846 ext4_error(sb
, "Error in loading buddy "
4847 "information for %u", group
);
4851 if (len
>= EXT4_BLOCKS_PER_GROUP(sb
))
4852 len
-= (EXT4_BLOCKS_PER_GROUP(sb
) - first_block
);
4856 if (e4b
.bd_info
->bb_free
>= minlen
) {
4857 cnt
= ext4_trim_all_free(sb
, &e4b
, first_block
,
4858 last_block
, minlen
);
4861 ext4_mb_unload_buddy(&e4b
);
4865 ext4_mb_unload_buddy(&e4b
);
4869 range
->len
= trimmed
* sb
->s_blocksize
;