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 (in clusters)
74 * pa_free -> free space available in this prealloc space (in clusters)
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 makes sure that
79 * 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 represented 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) within 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. The default value of s_mb_group_prealloc is
130 * dependent on the cluster size; for non-bigalloc file systems, it is
131 * 512 blocks. This can be tuned via
132 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
133 * terms of number of blocks. If we have mounted the file system with -O
134 * stripe=<value> option the group prealloc request is normalized to the
135 * the smallest multiple of the stripe value (sbi->s_stripe) which is
136 * greater than the default mb_group_prealloc.
138 * The regular allocator (using the buddy cache) supports a few tunables.
140 * /sys/fs/ext4/<partition>/mb_min_to_scan
141 * /sys/fs/ext4/<partition>/mb_max_to_scan
142 * /sys/fs/ext4/<partition>/mb_order2_req
144 * The regular allocator uses buddy scan only if the request len is power of
145 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
146 * value of s_mb_order2_reqs can be tuned via
147 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
148 * stripe size (sbi->s_stripe), we try to search for contiguous block in
149 * stripe size. This should result in better allocation on RAID setups. If
150 * not, we search in the specific group using bitmap for best extents. The
151 * tunable min_to_scan and max_to_scan control the behaviour here.
152 * min_to_scan indicate how long the mballoc __must__ look for a best
153 * extent and max_to_scan indicates how long the mballoc __can__ look for a
154 * best extent in the found extents. Searching for the blocks starts with
155 * the group specified as the goal value in allocation context via
156 * ac_g_ex. Each group is first checked based on the criteria whether it
157 * can be used for allocation. ext4_mb_good_group explains how the groups are
160 * Both the prealloc space are getting populated as above. So for the first
161 * request we will hit the buddy cache which will result in this prealloc
162 * space getting filled. The prealloc space is then later used for the
163 * subsequent request.
167 * mballoc operates on the following data:
169 * - in-core buddy (actually includes buddy and bitmap)
170 * - preallocation descriptors (PAs)
172 * there are two types of preallocations:
174 * assiged to specific inode and can be used for this inode only.
175 * it describes part of inode's space preallocated to specific
176 * physical blocks. any block from that preallocated can be used
177 * independent. the descriptor just tracks number of blocks left
178 * unused. so, before taking some block from descriptor, one must
179 * make sure corresponded logical block isn't allocated yet. this
180 * also means that freeing any block within descriptor's range
181 * must discard all preallocated blocks.
183 * assigned to specific locality group which does not translate to
184 * permanent set of inodes: inode can join and leave group. space
185 * from this type of preallocation can be used for any inode. thus
186 * it's consumed from the beginning to the end.
188 * relation between them can be expressed as:
189 * in-core buddy = on-disk bitmap + preallocation descriptors
191 * this mean blocks mballoc considers used are:
192 * - allocated blocks (persistent)
193 * - preallocated blocks (non-persistent)
195 * consistency in mballoc world means that at any time a block is either
196 * free or used in ALL structures. notice: "any time" should not be read
197 * literally -- time is discrete and delimited by locks.
199 * to keep it simple, we don't use block numbers, instead we count number of
200 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
202 * all operations can be expressed as:
203 * - init buddy: buddy = on-disk + PAs
204 * - new PA: buddy += N; PA = N
205 * - use inode PA: on-disk += N; PA -= N
206 * - discard inode PA buddy -= on-disk - PA; PA = 0
207 * - use locality group PA on-disk += N; PA -= N
208 * - discard locality group PA buddy -= PA; PA = 0
209 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
210 * is used in real operation because we can't know actual used
211 * bits from PA, only from on-disk bitmap
213 * if we follow this strict logic, then all operations above should be atomic.
214 * given some of them can block, we'd have to use something like semaphores
215 * killing performance on high-end SMP hardware. let's try to relax it using
216 * the following knowledge:
217 * 1) if buddy is referenced, it's already initialized
218 * 2) while block is used in buddy and the buddy is referenced,
219 * nobody can re-allocate that block
220 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
221 * bit set and PA claims same block, it's OK. IOW, one can set bit in
222 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
225 * so, now we're building a concurrency table:
228 * blocks for PA are allocated in the buddy, buddy must be referenced
229 * until PA is linked to allocation group to avoid concurrent buddy init
231 * we need to make sure that either on-disk bitmap or PA has uptodate data
232 * given (3) we care that PA-=N operation doesn't interfere with init
234 * the simplest way would be to have buddy initialized by the discard
235 * - use locality group PA
236 * again PA-=N must be serialized with init
237 * - discard locality group PA
238 * the simplest way would be to have buddy initialized by the discard
241 * i_data_sem serializes them
243 * discard process must wait until PA isn't used by another process
244 * - use locality group PA
245 * some mutex should serialize them
246 * - discard locality group PA
247 * discard process must wait until PA isn't used by another process
250 * i_data_sem or another mutex should serializes them
252 * discard process must wait until PA isn't used by another process
253 * - use locality group PA
254 * nothing wrong here -- they're different PAs covering different blocks
255 * - discard locality group PA
256 * discard process must wait until PA isn't used by another process
258 * now we're ready to make few consequences:
259 * - PA is referenced and while it is no discard is possible
260 * - PA is referenced until block isn't marked in on-disk bitmap
261 * - PA changes only after on-disk bitmap
262 * - discard must not compete with init. either init is done before
263 * any discard or they're serialized somehow
264 * - buddy init as sum of on-disk bitmap and PAs is done atomically
266 * a special case when we've used PA to emptiness. no need to modify buddy
267 * in this case, but we should care about concurrent init
272 * Logic in few words:
277 * mark bits in on-disk bitmap
280 * - use preallocation:
281 * find proper PA (per-inode or group)
283 * mark bits in on-disk bitmap
289 * mark bits in on-disk bitmap
292 * - discard preallocations in group:
294 * move them onto local list
295 * load on-disk bitmap
297 * remove PA from object (inode or locality group)
298 * mark free blocks in-core
300 * - discard inode's preallocations:
307 * - bitlock on a group (group)
308 * - object (inode/locality) (object)
319 * - release consumed pa:
324 * - generate in-core bitmap:
328 * - discard all for given object (inode, locality group):
333 * - discard all for given group:
340 static struct kmem_cache
*ext4_pspace_cachep
;
341 static struct kmem_cache
*ext4_ac_cachep
;
342 static struct kmem_cache
*ext4_free_ext_cachep
;
344 /* We create slab caches for groupinfo data structures based on the
345 * superblock block size. There will be one per mounted filesystem for
346 * each unique s_blocksize_bits */
347 #define NR_GRPINFO_CACHES 8
348 static struct kmem_cache
*ext4_groupinfo_caches
[NR_GRPINFO_CACHES
];
350 static const char *ext4_groupinfo_slab_names
[NR_GRPINFO_CACHES
] = {
351 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
352 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
353 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
356 static void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
358 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
360 static void release_blocks_on_commit(journal_t
*journal
, transaction_t
*txn
);
362 static inline void *mb_correct_addr_and_bit(int *bit
, void *addr
)
364 #if BITS_PER_LONG == 64
365 *bit
+= ((unsigned long) addr
& 7UL) << 3;
366 addr
= (void *) ((unsigned long) addr
& ~7UL);
367 #elif BITS_PER_LONG == 32
368 *bit
+= ((unsigned long) addr
& 3UL) << 3;
369 addr
= (void *) ((unsigned long) addr
& ~3UL);
371 #error "how many bits you are?!"
376 static inline int mb_test_bit(int bit
, void *addr
)
379 * ext4_test_bit on architecture like powerpc
380 * needs unsigned long aligned address
382 addr
= mb_correct_addr_and_bit(&bit
, addr
);
383 return ext4_test_bit(bit
, addr
);
386 static inline void mb_set_bit(int bit
, void *addr
)
388 addr
= mb_correct_addr_and_bit(&bit
, addr
);
389 ext4_set_bit(bit
, addr
);
392 static inline void mb_clear_bit(int bit
, void *addr
)
394 addr
= mb_correct_addr_and_bit(&bit
, addr
);
395 ext4_clear_bit(bit
, addr
);
398 static inline int mb_find_next_zero_bit(void *addr
, int max
, int start
)
400 int fix
= 0, ret
, tmpmax
;
401 addr
= mb_correct_addr_and_bit(&fix
, addr
);
405 ret
= ext4_find_next_zero_bit(addr
, tmpmax
, start
) - fix
;
411 static inline int mb_find_next_bit(void *addr
, int max
, int start
)
413 int fix
= 0, ret
, tmpmax
;
414 addr
= mb_correct_addr_and_bit(&fix
, addr
);
418 ret
= ext4_find_next_bit(addr
, tmpmax
, start
) - fix
;
424 static void *mb_find_buddy(struct ext4_buddy
*e4b
, int order
, int *max
)
428 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
431 if (order
> e4b
->bd_blkbits
+ 1) {
436 /* at order 0 we see each particular block */
438 *max
= 1 << (e4b
->bd_blkbits
+ 3);
439 return EXT4_MB_BITMAP(e4b
);
442 bb
= EXT4_MB_BUDDY(e4b
) + EXT4_SB(e4b
->bd_sb
)->s_mb_offsets
[order
];
443 *max
= EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[order
];
449 static void mb_free_blocks_double(struct inode
*inode
, struct ext4_buddy
*e4b
,
450 int first
, int count
)
453 struct super_block
*sb
= e4b
->bd_sb
;
455 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
457 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
458 for (i
= 0; i
< count
; i
++) {
459 if (!mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
)) {
460 ext4_fsblk_t blocknr
;
462 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
463 blocknr
+= EXT4_C2B(EXT4_SB(sb
), first
+ i
);
464 ext4_grp_locked_error(sb
, e4b
->bd_group
,
465 inode
? inode
->i_ino
: 0,
467 "freeing block already freed "
471 mb_clear_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
475 static void mb_mark_used_double(struct ext4_buddy
*e4b
, int first
, int count
)
479 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
481 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
482 for (i
= 0; i
< count
; i
++) {
483 BUG_ON(mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
));
484 mb_set_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
488 static void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
490 if (memcmp(e4b
->bd_info
->bb_bitmap
, bitmap
, e4b
->bd_sb
->s_blocksize
)) {
491 unsigned char *b1
, *b2
;
493 b1
= (unsigned char *) e4b
->bd_info
->bb_bitmap
;
494 b2
= (unsigned char *) bitmap
;
495 for (i
= 0; i
< e4b
->bd_sb
->s_blocksize
; i
++) {
496 if (b1
[i
] != b2
[i
]) {
497 ext4_msg(e4b
->bd_sb
, KERN_ERR
,
498 "corruption in group %u "
499 "at byte %u(%u): %x in copy != %x "
501 e4b
->bd_group
, i
, i
* 8, b1
[i
], b2
[i
]);
509 static inline void mb_free_blocks_double(struct inode
*inode
,
510 struct ext4_buddy
*e4b
, int first
, int count
)
514 static inline void mb_mark_used_double(struct ext4_buddy
*e4b
,
515 int first
, int count
)
519 static inline void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
525 #ifdef AGGRESSIVE_CHECK
527 #define MB_CHECK_ASSERT(assert) \
531 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
532 function, file, line, # assert); \
537 static int __mb_check_buddy(struct ext4_buddy
*e4b
, char *file
,
538 const char *function
, int line
)
540 struct super_block
*sb
= e4b
->bd_sb
;
541 int order
= e4b
->bd_blkbits
+ 1;
548 struct ext4_group_info
*grp
;
551 struct list_head
*cur
;
556 static int mb_check_counter
;
557 if (mb_check_counter
++ % 100 != 0)
562 buddy
= mb_find_buddy(e4b
, order
, &max
);
563 MB_CHECK_ASSERT(buddy
);
564 buddy2
= mb_find_buddy(e4b
, order
- 1, &max2
);
565 MB_CHECK_ASSERT(buddy2
);
566 MB_CHECK_ASSERT(buddy
!= buddy2
);
567 MB_CHECK_ASSERT(max
* 2 == max2
);
570 for (i
= 0; i
< max
; i
++) {
572 if (mb_test_bit(i
, buddy
)) {
573 /* only single bit in buddy2 may be 1 */
574 if (!mb_test_bit(i
<< 1, buddy2
)) {
576 mb_test_bit((i
<<1)+1, buddy2
));
577 } else if (!mb_test_bit((i
<< 1) + 1, buddy2
)) {
579 mb_test_bit(i
<< 1, buddy2
));
584 /* both bits in buddy2 must be 0 */
585 MB_CHECK_ASSERT(mb_test_bit(i
<< 1, buddy2
));
586 MB_CHECK_ASSERT(mb_test_bit((i
<< 1) + 1, buddy2
));
588 for (j
= 0; j
< (1 << order
); j
++) {
589 k
= (i
* (1 << order
)) + j
;
591 !mb_test_bit(k
, EXT4_MB_BITMAP(e4b
)));
595 MB_CHECK_ASSERT(e4b
->bd_info
->bb_counters
[order
] == count
);
600 buddy
= mb_find_buddy(e4b
, 0, &max
);
601 for (i
= 0; i
< max
; i
++) {
602 if (!mb_test_bit(i
, buddy
)) {
603 MB_CHECK_ASSERT(i
>= e4b
->bd_info
->bb_first_free
);
611 /* check used bits only */
612 for (j
= 0; j
< e4b
->bd_blkbits
+ 1; j
++) {
613 buddy2
= mb_find_buddy(e4b
, j
, &max2
);
615 MB_CHECK_ASSERT(k
< max2
);
616 MB_CHECK_ASSERT(mb_test_bit(k
, buddy2
));
619 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b
->bd_info
));
620 MB_CHECK_ASSERT(e4b
->bd_info
->bb_fragments
== fragments
);
622 grp
= ext4_get_group_info(sb
, e4b
->bd_group
);
623 list_for_each(cur
, &grp
->bb_prealloc_list
) {
624 ext4_group_t groupnr
;
625 struct ext4_prealloc_space
*pa
;
626 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
627 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &groupnr
, &k
);
628 MB_CHECK_ASSERT(groupnr
== e4b
->bd_group
);
629 for (i
= 0; i
< pa
->pa_len
; i
++)
630 MB_CHECK_ASSERT(mb_test_bit(k
+ i
, buddy
));
634 #undef MB_CHECK_ASSERT
635 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
636 __FILE__, __func__, __LINE__)
638 #define mb_check_buddy(e4b)
642 * Divide blocks started from @first with length @len into
643 * smaller chunks with power of 2 blocks.
644 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
645 * then increase bb_counters[] for corresponded chunk size.
647 static void ext4_mb_mark_free_simple(struct super_block
*sb
,
648 void *buddy
, ext4_grpblk_t first
, ext4_grpblk_t len
,
649 struct ext4_group_info
*grp
)
651 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
655 unsigned short border
;
657 BUG_ON(len
> EXT4_CLUSTERS_PER_GROUP(sb
));
659 border
= 2 << sb
->s_blocksize_bits
;
662 /* find how many blocks can be covered since this position */
663 max
= ffs(first
| border
) - 1;
665 /* find how many blocks of power 2 we need to mark */
672 /* mark multiblock chunks only */
673 grp
->bb_counters
[min
]++;
675 mb_clear_bit(first
>> min
,
676 buddy
+ sbi
->s_mb_offsets
[min
]);
684 * Cache the order of the largest free extent we have available in this block
688 mb_set_largest_free_order(struct super_block
*sb
, struct ext4_group_info
*grp
)
693 grp
->bb_largest_free_order
= -1; /* uninit */
695 bits
= sb
->s_blocksize_bits
+ 1;
696 for (i
= bits
; i
>= 0; i
--) {
697 if (grp
->bb_counters
[i
] > 0) {
698 grp
->bb_largest_free_order
= i
;
704 static noinline_for_stack
705 void ext4_mb_generate_buddy(struct super_block
*sb
,
706 void *buddy
, void *bitmap
, ext4_group_t group
)
708 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
709 ext4_grpblk_t max
= EXT4_CLUSTERS_PER_GROUP(sb
);
714 unsigned fragments
= 0;
715 unsigned long long period
= get_cycles();
717 /* initialize buddy from bitmap which is aggregation
718 * of on-disk bitmap and preallocations */
719 i
= mb_find_next_zero_bit(bitmap
, max
, 0);
720 grp
->bb_first_free
= i
;
724 i
= mb_find_next_bit(bitmap
, max
, i
);
728 ext4_mb_mark_free_simple(sb
, buddy
, first
, len
, grp
);
730 grp
->bb_counters
[0]++;
732 i
= mb_find_next_zero_bit(bitmap
, max
, i
);
734 grp
->bb_fragments
= fragments
;
736 if (free
!= grp
->bb_free
) {
737 ext4_grp_locked_error(sb
, group
, 0, 0,
738 "%u clusters in bitmap, %u in gd",
741 * If we intent to continue, we consider group descritor
742 * corrupt and update bb_free using bitmap value
746 mb_set_largest_free_order(sb
, grp
);
748 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
, &(grp
->bb_state
));
750 period
= get_cycles() - period
;
751 spin_lock(&EXT4_SB(sb
)->s_bal_lock
);
752 EXT4_SB(sb
)->s_mb_buddies_generated
++;
753 EXT4_SB(sb
)->s_mb_generation_time
+= period
;
754 spin_unlock(&EXT4_SB(sb
)->s_bal_lock
);
757 /* The buddy information is attached the buddy cache inode
758 * for convenience. The information regarding each group
759 * is loaded via ext4_mb_load_buddy. The information involve
760 * block bitmap and buddy information. The information are
761 * stored in the inode as
764 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
767 * one block each for bitmap and buddy information.
768 * So for each group we take up 2 blocks. A page can
769 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
770 * So it can have information regarding groups_per_page which
771 * is blocks_per_page/2
773 * Locking note: This routine takes the block group lock of all groups
774 * for this page; do not hold this lock when calling this routine!
777 static int ext4_mb_init_cache(struct page
*page
, char *incore
)
779 ext4_group_t ngroups
;
785 ext4_group_t first_group
;
787 struct super_block
*sb
;
788 struct buffer_head
*bhs
;
789 struct buffer_head
**bh
;
793 struct ext4_group_info
*grinfo
;
795 mb_debug(1, "init page %lu\n", page
->index
);
797 inode
= page
->mapping
->host
;
799 ngroups
= ext4_get_groups_count(sb
);
800 blocksize
= 1 << inode
->i_blkbits
;
801 blocks_per_page
= PAGE_CACHE_SIZE
/ blocksize
;
803 groups_per_page
= blocks_per_page
>> 1;
804 if (groups_per_page
== 0)
807 /* allocate buffer_heads to read bitmaps */
808 if (groups_per_page
> 1) {
810 i
= sizeof(struct buffer_head
*) * groups_per_page
;
811 bh
= kzalloc(i
, GFP_NOFS
);
817 first_group
= page
->index
* blocks_per_page
/ 2;
819 /* read all groups the page covers into the cache */
820 for (i
= 0; i
< groups_per_page
; i
++) {
821 struct ext4_group_desc
*desc
;
823 if (first_group
+ i
>= ngroups
)
826 grinfo
= ext4_get_group_info(sb
, first_group
+ i
);
828 * If page is uptodate then we came here after online resize
829 * which added some new uninitialized group info structs, so
830 * we must skip all initialized uptodate buddies on the page,
831 * which may be currently in use by an allocating task.
833 if (PageUptodate(page
) && !EXT4_MB_GRP_NEED_INIT(grinfo
)) {
839 desc
= ext4_get_group_desc(sb
, first_group
+ i
, NULL
);
844 bh
[i
] = sb_getblk(sb
, ext4_block_bitmap(sb
, desc
));
848 if (bitmap_uptodate(bh
[i
]))
852 if (bitmap_uptodate(bh
[i
])) {
853 unlock_buffer(bh
[i
]);
856 ext4_lock_group(sb
, first_group
+ i
);
857 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
858 ext4_init_block_bitmap(sb
, bh
[i
],
859 first_group
+ i
, desc
);
860 set_bitmap_uptodate(bh
[i
]);
861 set_buffer_uptodate(bh
[i
]);
862 ext4_unlock_group(sb
, first_group
+ i
);
863 unlock_buffer(bh
[i
]);
866 ext4_unlock_group(sb
, first_group
+ i
);
867 if (buffer_uptodate(bh
[i
])) {
869 * if not uninit if bh is uptodate,
870 * bitmap is also uptodate
872 set_bitmap_uptodate(bh
[i
]);
873 unlock_buffer(bh
[i
]);
878 * submit the buffer_head for read. We can
879 * safely mark the bitmap as uptodate now.
880 * We do it here so the bitmap uptodate bit
881 * get set with buffer lock held.
883 set_bitmap_uptodate(bh
[i
]);
884 bh
[i
]->b_end_io
= end_buffer_read_sync
;
885 submit_bh(READ
, bh
[i
]);
886 mb_debug(1, "read bitmap for group %u\n", first_group
+ i
);
889 /* wait for I/O completion */
890 for (i
= 0; i
< groups_per_page
; i
++)
892 wait_on_buffer(bh
[i
]);
895 for (i
= 0; i
< groups_per_page
; i
++)
896 if (bh
[i
] && !buffer_uptodate(bh
[i
]))
900 first_block
= page
->index
* blocks_per_page
;
901 for (i
= 0; i
< blocks_per_page
; i
++) {
904 group
= (first_block
+ i
) >> 1;
905 if (group
>= ngroups
)
908 if (!bh
[group
- first_group
])
909 /* skip initialized uptodate buddy */
913 * data carry information regarding this
914 * particular group in the format specified
918 data
= page_address(page
) + (i
* blocksize
);
919 bitmap
= bh
[group
- first_group
]->b_data
;
922 * We place the buddy block and bitmap block
925 if ((first_block
+ i
) & 1) {
926 /* this is block of buddy */
927 BUG_ON(incore
== NULL
);
928 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
929 group
, page
->index
, i
* blocksize
);
930 trace_ext4_mb_buddy_bitmap_load(sb
, group
);
931 grinfo
= ext4_get_group_info(sb
, group
);
932 grinfo
->bb_fragments
= 0;
933 memset(grinfo
->bb_counters
, 0,
934 sizeof(*grinfo
->bb_counters
) *
935 (sb
->s_blocksize_bits
+2));
937 * incore got set to the group block bitmap below
939 ext4_lock_group(sb
, group
);
941 memset(data
, 0xff, blocksize
);
942 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
943 ext4_unlock_group(sb
, group
);
946 /* this is block of bitmap */
947 BUG_ON(incore
!= NULL
);
948 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
949 group
, page
->index
, i
* blocksize
);
950 trace_ext4_mb_bitmap_load(sb
, group
);
952 /* see comments in ext4_mb_put_pa() */
953 ext4_lock_group(sb
, group
);
954 memcpy(data
, bitmap
, blocksize
);
956 /* mark all preallocated blks used in in-core bitmap */
957 ext4_mb_generate_from_pa(sb
, data
, group
);
958 ext4_mb_generate_from_freelist(sb
, data
, group
);
959 ext4_unlock_group(sb
, group
);
961 /* set incore so that the buddy information can be
962 * generated using this
967 SetPageUptodate(page
);
971 for (i
= 0; i
< groups_per_page
; i
++)
980 * Lock the buddy and bitmap pages. This make sure other parallel init_group
981 * on the same buddy page doesn't happen whild holding the buddy page lock.
982 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
983 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
985 static int ext4_mb_get_buddy_page_lock(struct super_block
*sb
,
986 ext4_group_t group
, struct ext4_buddy
*e4b
)
988 struct inode
*inode
= EXT4_SB(sb
)->s_buddy_cache
;
989 int block
, pnum
, poff
;
993 e4b
->bd_buddy_page
= NULL
;
994 e4b
->bd_bitmap_page
= NULL
;
996 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
998 * the buddy cache inode stores the block bitmap
999 * and buddy information in consecutive blocks.
1000 * So for each group we need two blocks.
1003 pnum
= block
/ blocks_per_page
;
1004 poff
= block
% blocks_per_page
;
1005 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1008 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1009 e4b
->bd_bitmap_page
= page
;
1010 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1012 if (blocks_per_page
>= 2) {
1013 /* buddy and bitmap are on the same page */
1018 pnum
= block
/ blocks_per_page
;
1019 poff
= block
% blocks_per_page
;
1020 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1023 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1024 e4b
->bd_buddy_page
= page
;
1028 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy
*e4b
)
1030 if (e4b
->bd_bitmap_page
) {
1031 unlock_page(e4b
->bd_bitmap_page
);
1032 page_cache_release(e4b
->bd_bitmap_page
);
1034 if (e4b
->bd_buddy_page
) {
1035 unlock_page(e4b
->bd_buddy_page
);
1036 page_cache_release(e4b
->bd_buddy_page
);
1041 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1042 * block group lock of all groups for this page; do not hold the BG lock when
1043 * calling this routine!
1045 static noinline_for_stack
1046 int ext4_mb_init_group(struct super_block
*sb
, ext4_group_t group
)
1049 struct ext4_group_info
*this_grp
;
1050 struct ext4_buddy e4b
;
1054 mb_debug(1, "init group %u\n", group
);
1055 this_grp
= ext4_get_group_info(sb
, group
);
1057 * This ensures that we don't reinit the buddy cache
1058 * page which map to the group from which we are already
1059 * allocating. If we are looking at the buddy cache we would
1060 * have taken a reference using ext4_mb_load_buddy and that
1061 * would have pinned buddy page to page cache.
1063 ret
= ext4_mb_get_buddy_page_lock(sb
, group
, &e4b
);
1064 if (ret
|| !EXT4_MB_GRP_NEED_INIT(this_grp
)) {
1066 * somebody initialized the group
1067 * return without doing anything
1072 page
= e4b
.bd_bitmap_page
;
1073 ret
= ext4_mb_init_cache(page
, NULL
);
1076 if (!PageUptodate(page
)) {
1080 mark_page_accessed(page
);
1082 if (e4b
.bd_buddy_page
== NULL
) {
1084 * If both the bitmap and buddy are in
1085 * the same page we don't need to force
1091 /* init buddy cache */
1092 page
= e4b
.bd_buddy_page
;
1093 ret
= ext4_mb_init_cache(page
, e4b
.bd_bitmap
);
1096 if (!PageUptodate(page
)) {
1100 mark_page_accessed(page
);
1102 ext4_mb_put_buddy_page_lock(&e4b
);
1107 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1108 * block group lock of all groups for this page; do not hold the BG lock when
1109 * calling this routine!
1111 static noinline_for_stack
int
1112 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
1113 struct ext4_buddy
*e4b
)
1115 int blocks_per_page
;
1121 struct ext4_group_info
*grp
;
1122 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1123 struct inode
*inode
= sbi
->s_buddy_cache
;
1125 mb_debug(1, "load group %u\n", group
);
1127 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1128 grp
= ext4_get_group_info(sb
, group
);
1130 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
1133 e4b
->bd_group
= group
;
1134 e4b
->bd_buddy_page
= NULL
;
1135 e4b
->bd_bitmap_page
= NULL
;
1137 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1139 * we need full data about the group
1140 * to make a good selection
1142 ret
= ext4_mb_init_group(sb
, group
);
1148 * the buddy cache inode stores the block bitmap
1149 * and buddy information in consecutive blocks.
1150 * So for each group we need two blocks.
1153 pnum
= block
/ blocks_per_page
;
1154 poff
= block
% blocks_per_page
;
1156 /* we could use find_or_create_page(), but it locks page
1157 * what we'd like to avoid in fast path ... */
1158 page
= find_get_page(inode
->i_mapping
, pnum
);
1159 if (page
== NULL
|| !PageUptodate(page
)) {
1162 * drop the page reference and try
1163 * to get the page with lock. If we
1164 * are not uptodate that implies
1165 * somebody just created the page but
1166 * is yet to initialize the same. So
1167 * wait for it to initialize.
1169 page_cache_release(page
);
1170 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1172 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1173 if (!PageUptodate(page
)) {
1174 ret
= ext4_mb_init_cache(page
, NULL
);
1179 mb_cmp_bitmaps(e4b
, page_address(page
) +
1180 (poff
* sb
->s_blocksize
));
1185 if (page
== NULL
|| !PageUptodate(page
)) {
1189 e4b
->bd_bitmap_page
= page
;
1190 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1191 mark_page_accessed(page
);
1194 pnum
= block
/ blocks_per_page
;
1195 poff
= block
% blocks_per_page
;
1197 page
= find_get_page(inode
->i_mapping
, pnum
);
1198 if (page
== NULL
|| !PageUptodate(page
)) {
1200 page_cache_release(page
);
1201 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1203 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1204 if (!PageUptodate(page
)) {
1205 ret
= ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
1214 if (page
== NULL
|| !PageUptodate(page
)) {
1218 e4b
->bd_buddy_page
= page
;
1219 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
1220 mark_page_accessed(page
);
1222 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
1223 BUG_ON(e4b
->bd_buddy_page
== NULL
);
1229 page_cache_release(page
);
1230 if (e4b
->bd_bitmap_page
)
1231 page_cache_release(e4b
->bd_bitmap_page
);
1232 if (e4b
->bd_buddy_page
)
1233 page_cache_release(e4b
->bd_buddy_page
);
1234 e4b
->bd_buddy
= NULL
;
1235 e4b
->bd_bitmap
= NULL
;
1239 static void ext4_mb_unload_buddy(struct ext4_buddy
*e4b
)
1241 if (e4b
->bd_bitmap_page
)
1242 page_cache_release(e4b
->bd_bitmap_page
);
1243 if (e4b
->bd_buddy_page
)
1244 page_cache_release(e4b
->bd_buddy_page
);
1248 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
1253 BUG_ON(EXT4_MB_BITMAP(e4b
) == EXT4_MB_BUDDY(e4b
));
1254 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
1256 bb
= EXT4_MB_BUDDY(e4b
);
1257 while (order
<= e4b
->bd_blkbits
+ 1) {
1259 if (!mb_test_bit(block
, bb
)) {
1260 /* this block is part of buddy of order 'order' */
1263 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1269 static void mb_clear_bits(void *bm
, int cur
, int len
)
1275 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1276 /* fast path: clear whole word at once */
1277 addr
= bm
+ (cur
>> 3);
1282 mb_clear_bit(cur
, bm
);
1287 void ext4_set_bits(void *bm
, int cur
, int len
)
1293 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1294 /* fast path: set whole word at once */
1295 addr
= bm
+ (cur
>> 3);
1300 mb_set_bit(cur
, bm
);
1305 static void mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1306 int first
, int count
)
1313 struct super_block
*sb
= e4b
->bd_sb
;
1315 BUG_ON(first
+ count
> (sb
->s_blocksize
<< 3));
1316 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
1317 mb_check_buddy(e4b
);
1318 mb_free_blocks_double(inode
, e4b
, first
, count
);
1320 e4b
->bd_info
->bb_free
+= count
;
1321 if (first
< e4b
->bd_info
->bb_first_free
)
1322 e4b
->bd_info
->bb_first_free
= first
;
1324 /* let's maintain fragments counter */
1326 block
= !mb_test_bit(first
- 1, EXT4_MB_BITMAP(e4b
));
1327 if (first
+ count
< EXT4_SB(sb
)->s_mb_maxs
[0])
1328 max
= !mb_test_bit(first
+ count
, EXT4_MB_BITMAP(e4b
));
1330 e4b
->bd_info
->bb_fragments
--;
1331 else if (!block
&& !max
)
1332 e4b
->bd_info
->bb_fragments
++;
1334 /* let's maintain buddy itself */
1335 while (count
-- > 0) {
1339 if (!mb_test_bit(block
, EXT4_MB_BITMAP(e4b
))) {
1340 ext4_fsblk_t blocknr
;
1342 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1343 blocknr
+= EXT4_C2B(EXT4_SB(sb
), block
);
1344 ext4_grp_locked_error(sb
, e4b
->bd_group
,
1345 inode
? inode
->i_ino
: 0,
1347 "freeing already freed block "
1350 mb_clear_bit(block
, EXT4_MB_BITMAP(e4b
));
1351 e4b
->bd_info
->bb_counters
[order
]++;
1353 /* start of the buddy */
1354 buddy
= mb_find_buddy(e4b
, order
, &max
);
1358 if (mb_test_bit(block
, buddy
) ||
1359 mb_test_bit(block
+ 1, buddy
))
1362 /* both the buddies are free, try to coalesce them */
1363 buddy2
= mb_find_buddy(e4b
, order
+ 1, &max
);
1369 /* for special purposes, we don't set
1370 * free bits in bitmap */
1371 mb_set_bit(block
, buddy
);
1372 mb_set_bit(block
+ 1, buddy
);
1374 e4b
->bd_info
->bb_counters
[order
]--;
1375 e4b
->bd_info
->bb_counters
[order
]--;
1379 e4b
->bd_info
->bb_counters
[order
]++;
1381 mb_clear_bit(block
, buddy2
);
1385 mb_set_largest_free_order(sb
, e4b
->bd_info
);
1386 mb_check_buddy(e4b
);
1389 static int mb_find_extent(struct ext4_buddy
*e4b
, int order
, int block
,
1390 int needed
, struct ext4_free_extent
*ex
)
1397 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1400 buddy
= mb_find_buddy(e4b
, order
, &max
);
1401 BUG_ON(buddy
== NULL
);
1402 BUG_ON(block
>= max
);
1403 if (mb_test_bit(block
, buddy
)) {
1410 /* FIXME dorp order completely ? */
1411 if (likely(order
== 0)) {
1412 /* find actual order */
1413 order
= mb_find_order_for_block(e4b
, block
);
1414 block
= block
>> order
;
1417 ex
->fe_len
= 1 << order
;
1418 ex
->fe_start
= block
<< order
;
1419 ex
->fe_group
= e4b
->bd_group
;
1421 /* calc difference from given start */
1422 next
= next
- ex
->fe_start
;
1424 ex
->fe_start
+= next
;
1426 while (needed
> ex
->fe_len
&&
1427 (buddy
= mb_find_buddy(e4b
, order
, &max
))) {
1429 if (block
+ 1 >= max
)
1432 next
= (block
+ 1) * (1 << order
);
1433 if (mb_test_bit(next
, EXT4_MB_BITMAP(e4b
)))
1436 ord
= mb_find_order_for_block(e4b
, next
);
1439 block
= next
>> order
;
1440 ex
->fe_len
+= 1 << order
;
1443 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1447 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1453 int start
= ex
->fe_start
;
1454 int len
= ex
->fe_len
;
1459 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1460 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1461 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1462 mb_check_buddy(e4b
);
1463 mb_mark_used_double(e4b
, start
, len
);
1465 e4b
->bd_info
->bb_free
-= len
;
1466 if (e4b
->bd_info
->bb_first_free
== start
)
1467 e4b
->bd_info
->bb_first_free
+= len
;
1469 /* let's maintain fragments counter */
1471 mlen
= !mb_test_bit(start
- 1, EXT4_MB_BITMAP(e4b
));
1472 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1473 max
= !mb_test_bit(start
+ len
, EXT4_MB_BITMAP(e4b
));
1475 e4b
->bd_info
->bb_fragments
++;
1476 else if (!mlen
&& !max
)
1477 e4b
->bd_info
->bb_fragments
--;
1479 /* let's maintain buddy itself */
1481 ord
= mb_find_order_for_block(e4b
, start
);
1483 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1484 /* the whole chunk may be allocated at once! */
1486 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1487 BUG_ON((start
>> ord
) >= max
);
1488 mb_set_bit(start
>> ord
, buddy
);
1489 e4b
->bd_info
->bb_counters
[ord
]--;
1496 /* store for history */
1498 ret
= len
| (ord
<< 16);
1500 /* we have to split large buddy */
1502 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1503 mb_set_bit(start
>> ord
, buddy
);
1504 e4b
->bd_info
->bb_counters
[ord
]--;
1507 cur
= (start
>> ord
) & ~1U;
1508 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1509 mb_clear_bit(cur
, buddy
);
1510 mb_clear_bit(cur
+ 1, buddy
);
1511 e4b
->bd_info
->bb_counters
[ord
]++;
1512 e4b
->bd_info
->bb_counters
[ord
]++;
1514 mb_set_largest_free_order(e4b
->bd_sb
, e4b
->bd_info
);
1516 ext4_set_bits(EXT4_MB_BITMAP(e4b
), ex
->fe_start
, len0
);
1517 mb_check_buddy(e4b
);
1523 * Must be called under group lock!
1525 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1526 struct ext4_buddy
*e4b
)
1528 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1531 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1532 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1534 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1535 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1536 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1538 /* preallocation can change ac_b_ex, thus we store actually
1539 * allocated blocks for history */
1540 ac
->ac_f_ex
= ac
->ac_b_ex
;
1542 ac
->ac_status
= AC_STATUS_FOUND
;
1543 ac
->ac_tail
= ret
& 0xffff;
1544 ac
->ac_buddy
= ret
>> 16;
1547 * take the page reference. We want the page to be pinned
1548 * so that we don't get a ext4_mb_init_cache_call for this
1549 * group until we update the bitmap. That would mean we
1550 * double allocate blocks. The reference is dropped
1551 * in ext4_mb_release_context
1553 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1554 get_page(ac
->ac_bitmap_page
);
1555 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1556 get_page(ac
->ac_buddy_page
);
1557 /* store last allocated for subsequent stream allocation */
1558 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
1559 spin_lock(&sbi
->s_md_lock
);
1560 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1561 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1562 spin_unlock(&sbi
->s_md_lock
);
1567 * regular allocator, for general purposes allocation
1570 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1571 struct ext4_buddy
*e4b
,
1574 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1575 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1576 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1577 struct ext4_free_extent ex
;
1580 if (ac
->ac_status
== AC_STATUS_FOUND
)
1583 * We don't want to scan for a whole year
1585 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1586 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1587 ac
->ac_status
= AC_STATUS_BREAK
;
1592 * Haven't found good chunk so far, let's continue
1594 if (bex
->fe_len
< gex
->fe_len
)
1597 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1598 && bex
->fe_group
== e4b
->bd_group
) {
1599 /* recheck chunk's availability - we don't know
1600 * when it was found (within this lock-unlock
1602 max
= mb_find_extent(e4b
, 0, bex
->fe_start
, gex
->fe_len
, &ex
);
1603 if (max
>= gex
->fe_len
) {
1604 ext4_mb_use_best_found(ac
, e4b
);
1611 * The routine checks whether found extent is good enough. If it is,
1612 * then the extent gets marked used and flag is set to the context
1613 * to stop scanning. Otherwise, the extent is compared with the
1614 * previous found extent and if new one is better, then it's stored
1615 * in the context. Later, the best found extent will be used, if
1616 * mballoc can't find good enough extent.
1618 * FIXME: real allocation policy is to be designed yet!
1620 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1621 struct ext4_free_extent
*ex
,
1622 struct ext4_buddy
*e4b
)
1624 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1625 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1627 BUG_ON(ex
->fe_len
<= 0);
1628 BUG_ON(ex
->fe_len
> EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1629 BUG_ON(ex
->fe_start
>= EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1630 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1635 * The special case - take what you catch first
1637 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1639 ext4_mb_use_best_found(ac
, e4b
);
1644 * Let's check whether the chuck is good enough
1646 if (ex
->fe_len
== gex
->fe_len
) {
1648 ext4_mb_use_best_found(ac
, e4b
);
1653 * If this is first found extent, just store it in the context
1655 if (bex
->fe_len
== 0) {
1661 * If new found extent is better, store it in the context
1663 if (bex
->fe_len
< gex
->fe_len
) {
1664 /* if the request isn't satisfied, any found extent
1665 * larger than previous best one is better */
1666 if (ex
->fe_len
> bex
->fe_len
)
1668 } else if (ex
->fe_len
> gex
->fe_len
) {
1669 /* if the request is satisfied, then we try to find
1670 * an extent that still satisfy the request, but is
1671 * smaller than previous one */
1672 if (ex
->fe_len
< bex
->fe_len
)
1676 ext4_mb_check_limits(ac
, e4b
, 0);
1679 static noinline_for_stack
1680 int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1681 struct ext4_buddy
*e4b
)
1683 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1684 ext4_group_t group
= ex
.fe_group
;
1688 BUG_ON(ex
.fe_len
<= 0);
1689 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1693 ext4_lock_group(ac
->ac_sb
, group
);
1694 max
= mb_find_extent(e4b
, 0, ex
.fe_start
, ex
.fe_len
, &ex
);
1698 ext4_mb_use_best_found(ac
, e4b
);
1701 ext4_unlock_group(ac
->ac_sb
, group
);
1702 ext4_mb_unload_buddy(e4b
);
1707 static noinline_for_stack
1708 int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1709 struct ext4_buddy
*e4b
)
1711 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1714 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1715 struct ext4_free_extent ex
;
1717 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1720 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1724 ext4_lock_group(ac
->ac_sb
, group
);
1725 max
= mb_find_extent(e4b
, 0, ac
->ac_g_ex
.fe_start
,
1726 ac
->ac_g_ex
.fe_len
, &ex
);
1728 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1731 start
= ext4_group_first_block_no(ac
->ac_sb
, e4b
->bd_group
) +
1733 /* use do_div to get remainder (would be 64-bit modulo) */
1734 if (do_div(start
, sbi
->s_stripe
) == 0) {
1737 ext4_mb_use_best_found(ac
, e4b
);
1739 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1740 BUG_ON(ex
.fe_len
<= 0);
1741 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1742 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1745 ext4_mb_use_best_found(ac
, e4b
);
1746 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1747 /* Sometimes, caller may want to merge even small
1748 * number of blocks to an existing extent */
1749 BUG_ON(ex
.fe_len
<= 0);
1750 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1751 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1754 ext4_mb_use_best_found(ac
, e4b
);
1756 ext4_unlock_group(ac
->ac_sb
, group
);
1757 ext4_mb_unload_buddy(e4b
);
1763 * The routine scans buddy structures (not bitmap!) from given order
1764 * to max order and tries to find big enough chunk to satisfy the req
1766 static noinline_for_stack
1767 void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1768 struct ext4_buddy
*e4b
)
1770 struct super_block
*sb
= ac
->ac_sb
;
1771 struct ext4_group_info
*grp
= e4b
->bd_info
;
1777 BUG_ON(ac
->ac_2order
<= 0);
1778 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1779 if (grp
->bb_counters
[i
] == 0)
1782 buddy
= mb_find_buddy(e4b
, i
, &max
);
1783 BUG_ON(buddy
== NULL
);
1785 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1790 ac
->ac_b_ex
.fe_len
= 1 << i
;
1791 ac
->ac_b_ex
.fe_start
= k
<< i
;
1792 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1794 ext4_mb_use_best_found(ac
, e4b
);
1796 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1798 if (EXT4_SB(sb
)->s_mb_stats
)
1799 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1806 * The routine scans the group and measures all found extents.
1807 * In order to optimize scanning, caller must pass number of
1808 * free blocks in the group, so the routine can know upper limit.
1810 static noinline_for_stack
1811 void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1812 struct ext4_buddy
*e4b
)
1814 struct super_block
*sb
= ac
->ac_sb
;
1815 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1816 struct ext4_free_extent ex
;
1820 free
= e4b
->bd_info
->bb_free
;
1823 i
= e4b
->bd_info
->bb_first_free
;
1825 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1826 i
= mb_find_next_zero_bit(bitmap
,
1827 EXT4_CLUSTERS_PER_GROUP(sb
), i
);
1828 if (i
>= EXT4_CLUSTERS_PER_GROUP(sb
)) {
1830 * IF we have corrupt bitmap, we won't find any
1831 * free blocks even though group info says we
1832 * we have free blocks
1834 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1835 "%d free clusters as per "
1836 "group info. But bitmap says 0",
1841 mb_find_extent(e4b
, 0, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1842 BUG_ON(ex
.fe_len
<= 0);
1843 if (free
< ex
.fe_len
) {
1844 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1845 "%d free clusters as per "
1846 "group info. But got %d blocks",
1849 * The number of free blocks differs. This mostly
1850 * indicate that the bitmap is corrupt. So exit
1851 * without claiming the space.
1856 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1862 ext4_mb_check_limits(ac
, e4b
, 1);
1866 * This is a special case for storages like raid5
1867 * we try to find stripe-aligned chunks for stripe-size-multiple requests
1869 static noinline_for_stack
1870 void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1871 struct ext4_buddy
*e4b
)
1873 struct super_block
*sb
= ac
->ac_sb
;
1874 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1875 void *bitmap
= EXT4_MB_BITMAP(e4b
);
1876 struct ext4_free_extent ex
;
1877 ext4_fsblk_t first_group_block
;
1882 BUG_ON(sbi
->s_stripe
== 0);
1884 /* find first stripe-aligned block in group */
1885 first_group_block
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1887 a
= first_group_block
+ sbi
->s_stripe
- 1;
1888 do_div(a
, sbi
->s_stripe
);
1889 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1891 while (i
< EXT4_CLUSTERS_PER_GROUP(sb
)) {
1892 if (!mb_test_bit(i
, bitmap
)) {
1893 max
= mb_find_extent(e4b
, 0, i
, sbi
->s_stripe
, &ex
);
1894 if (max
>= sbi
->s_stripe
) {
1897 ext4_mb_use_best_found(ac
, e4b
);
1905 /* This is now called BEFORE we load the buddy bitmap. */
1906 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
1907 ext4_group_t group
, int cr
)
1909 unsigned free
, fragments
;
1910 int flex_size
= ext4_flex_bg_size(EXT4_SB(ac
->ac_sb
));
1911 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1913 BUG_ON(cr
< 0 || cr
>= 4);
1915 /* We only do this if the grp has never been initialized */
1916 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1917 int ret
= ext4_mb_init_group(ac
->ac_sb
, group
);
1922 free
= grp
->bb_free
;
1923 fragments
= grp
->bb_fragments
;
1931 BUG_ON(ac
->ac_2order
== 0);
1933 if (grp
->bb_largest_free_order
< ac
->ac_2order
)
1936 /* Avoid using the first bg of a flexgroup for data files */
1937 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
) &&
1938 (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) &&
1939 ((group
% flex_size
) == 0))
1944 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
1948 if (free
>= ac
->ac_g_ex
.fe_len
)
1960 static noinline_for_stack
int
1961 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
1963 ext4_group_t ngroups
, group
, i
;
1966 struct ext4_sb_info
*sbi
;
1967 struct super_block
*sb
;
1968 struct ext4_buddy e4b
;
1972 ngroups
= ext4_get_groups_count(sb
);
1973 /* non-extent files are limited to low blocks/groups */
1974 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)))
1975 ngroups
= sbi
->s_blockfile_groups
;
1977 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1979 /* first, try the goal */
1980 err
= ext4_mb_find_by_goal(ac
, &e4b
);
1981 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
1984 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
1988 * ac->ac2_order is set only if the fe_len is a power of 2
1989 * if ac2_order is set we also set criteria to 0 so that we
1990 * try exact allocation using buddy.
1992 i
= fls(ac
->ac_g_ex
.fe_len
);
1995 * We search using buddy data only if the order of the request
1996 * is greater than equal to the sbi_s_mb_order2_reqs
1997 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
1999 if (i
>= sbi
->s_mb_order2_reqs
) {
2001 * This should tell if fe_len is exactly power of 2
2003 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
2004 ac
->ac_2order
= i
- 1;
2007 /* if stream allocation is enabled, use global goal */
2008 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
2009 /* TBD: may be hot point */
2010 spin_lock(&sbi
->s_md_lock
);
2011 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
2012 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
2013 spin_unlock(&sbi
->s_md_lock
);
2016 /* Let's just scan groups to find more-less suitable blocks */
2017 cr
= ac
->ac_2order
? 0 : 1;
2019 * cr == 0 try to get exact allocation,
2020 * cr == 3 try to get anything
2023 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
2024 ac
->ac_criteria
= cr
;
2026 * searching for the right group start
2027 * from the goal value specified
2029 group
= ac
->ac_g_ex
.fe_group
;
2031 for (i
= 0; i
< ngroups
; group
++, i
++) {
2032 if (group
== ngroups
)
2035 /* This now checks without needing the buddy page */
2036 if (!ext4_mb_good_group(ac
, group
, cr
))
2039 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2043 ext4_lock_group(sb
, group
);
2046 * We need to check again after locking the
2049 if (!ext4_mb_good_group(ac
, group
, cr
)) {
2050 ext4_unlock_group(sb
, group
);
2051 ext4_mb_unload_buddy(&e4b
);
2055 ac
->ac_groups_scanned
++;
2057 ext4_mb_simple_scan_group(ac
, &e4b
);
2058 else if (cr
== 1 && sbi
->s_stripe
&&
2059 !(ac
->ac_g_ex
.fe_len
% sbi
->s_stripe
))
2060 ext4_mb_scan_aligned(ac
, &e4b
);
2062 ext4_mb_complex_scan_group(ac
, &e4b
);
2064 ext4_unlock_group(sb
, group
);
2065 ext4_mb_unload_buddy(&e4b
);
2067 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
2072 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
2073 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
2075 * We've been searching too long. Let's try to allocate
2076 * the best chunk we've found so far
2079 ext4_mb_try_best_found(ac
, &e4b
);
2080 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
2082 * Someone more lucky has already allocated it.
2083 * The only thing we can do is just take first
2085 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2087 ac
->ac_b_ex
.fe_group
= 0;
2088 ac
->ac_b_ex
.fe_start
= 0;
2089 ac
->ac_b_ex
.fe_len
= 0;
2090 ac
->ac_status
= AC_STATUS_CONTINUE
;
2091 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
2093 atomic_inc(&sbi
->s_mb_lost_chunks
);
2101 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2103 struct super_block
*sb
= seq
->private;
2106 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2109 return (void *) ((unsigned long) group
);
2112 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2114 struct super_block
*sb
= seq
->private;
2118 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2121 return (void *) ((unsigned long) group
);
2124 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2126 struct super_block
*sb
= seq
->private;
2127 ext4_group_t group
= (ext4_group_t
) ((unsigned long) v
);
2130 struct ext4_buddy e4b
;
2132 struct ext4_group_info info
;
2133 ext4_grpblk_t counters
[16];
2138 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2139 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2140 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2141 "group", "free", "frags", "first",
2142 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2143 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2145 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2146 sizeof(struct ext4_group_info
);
2147 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2149 seq_printf(seq
, "#%-5u: I/O error\n", group
);
2152 ext4_lock_group(sb
, group
);
2153 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2154 ext4_unlock_group(sb
, group
);
2155 ext4_mb_unload_buddy(&e4b
);
2157 seq_printf(seq
, "#%-5u: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2158 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2159 for (i
= 0; i
<= 13; i
++)
2160 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2161 sg
.info
.bb_counters
[i
] : 0);
2162 seq_printf(seq
, " ]\n");
2167 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2171 static const struct seq_operations ext4_mb_seq_groups_ops
= {
2172 .start
= ext4_mb_seq_groups_start
,
2173 .next
= ext4_mb_seq_groups_next
,
2174 .stop
= ext4_mb_seq_groups_stop
,
2175 .show
= ext4_mb_seq_groups_show
,
2178 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2180 struct super_block
*sb
= PDE(inode
)->data
;
2183 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2185 struct seq_file
*m
= file
->private_data
;
2192 static const struct file_operations ext4_mb_seq_groups_fops
= {
2193 .owner
= THIS_MODULE
,
2194 .open
= ext4_mb_seq_groups_open
,
2196 .llseek
= seq_lseek
,
2197 .release
= seq_release
,
2200 static struct kmem_cache
*get_groupinfo_cache(int blocksize_bits
)
2202 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2203 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[cache_index
];
2209 /* Create and initialize ext4_group_info data for the given group. */
2210 int ext4_mb_add_groupinfo(struct super_block
*sb
, ext4_group_t group
,
2211 struct ext4_group_desc
*desc
)
2215 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2216 struct ext4_group_info
**meta_group_info
;
2217 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2220 * First check if this group is the first of a reserved block.
2221 * If it's true, we have to allocate a new table of pointers
2222 * to ext4_group_info structures
2224 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2225 metalen
= sizeof(*meta_group_info
) <<
2226 EXT4_DESC_PER_BLOCK_BITS(sb
);
2227 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2228 if (meta_group_info
== NULL
) {
2229 ext4_msg(sb
, KERN_ERR
, "EXT4-fs: can't allocate mem "
2230 "for a buddy group");
2231 goto exit_meta_group_info
;
2233 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] =
2238 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2239 i
= group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2241 meta_group_info
[i
] = kmem_cache_alloc(cachep
, GFP_KERNEL
);
2242 if (meta_group_info
[i
] == NULL
) {
2243 ext4_msg(sb
, KERN_ERR
, "EXT4-fs: can't allocate buddy mem");
2244 goto exit_group_info
;
2246 memset(meta_group_info
[i
], 0, kmem_cache_size(cachep
));
2247 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2248 &(meta_group_info
[i
]->bb_state
));
2251 * initialize bb_free to be able to skip
2252 * empty groups without initialization
2254 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2255 meta_group_info
[i
]->bb_free
=
2256 ext4_free_clusters_after_init(sb
, group
, desc
);
2258 meta_group_info
[i
]->bb_free
=
2259 ext4_free_group_clusters(sb
, desc
);
2262 INIT_LIST_HEAD(&meta_group_info
[i
]->bb_prealloc_list
);
2263 init_rwsem(&meta_group_info
[i
]->alloc_sem
);
2264 meta_group_info
[i
]->bb_free_root
= RB_ROOT
;
2265 meta_group_info
[i
]->bb_largest_free_order
= -1; /* uninit */
2269 struct buffer_head
*bh
;
2270 meta_group_info
[i
]->bb_bitmap
=
2271 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2272 BUG_ON(meta_group_info
[i
]->bb_bitmap
== NULL
);
2273 bh
= ext4_read_block_bitmap(sb
, group
);
2275 memcpy(meta_group_info
[i
]->bb_bitmap
, bh
->b_data
,
2284 /* If a meta_group_info table has been allocated, release it now */
2285 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2286 kfree(sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)]);
2287 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] = NULL
;
2289 exit_meta_group_info
:
2291 } /* ext4_mb_add_groupinfo */
2293 static int ext4_mb_init_backend(struct super_block
*sb
)
2295 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2297 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2298 struct ext4_super_block
*es
= sbi
->s_es
;
2299 int num_meta_group_infos
;
2300 int num_meta_group_infos_max
;
2302 struct ext4_group_desc
*desc
;
2303 struct kmem_cache
*cachep
;
2305 /* This is the number of blocks used by GDT */
2306 num_meta_group_infos
= (ngroups
+ EXT4_DESC_PER_BLOCK(sb
) -
2307 1) >> EXT4_DESC_PER_BLOCK_BITS(sb
);
2310 * This is the total number of blocks used by GDT including
2311 * the number of reserved blocks for GDT.
2312 * The s_group_info array is allocated with this value
2313 * to allow a clean online resize without a complex
2314 * manipulation of pointer.
2315 * The drawback is the unused memory when no resize
2316 * occurs but it's very low in terms of pages
2317 * (see comments below)
2318 * Need to handle this properly when META_BG resizing is allowed
2320 num_meta_group_infos_max
= num_meta_group_infos
+
2321 le16_to_cpu(es
->s_reserved_gdt_blocks
);
2324 * array_size is the size of s_group_info array. We round it
2325 * to the next power of two because this approximation is done
2326 * internally by kmalloc so we can have some more memory
2327 * for free here (e.g. may be used for META_BG resize).
2330 while (array_size
< sizeof(*sbi
->s_group_info
) *
2331 num_meta_group_infos_max
)
2332 array_size
= array_size
<< 1;
2333 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2334 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2335 * So a two level scheme suffices for now. */
2336 sbi
->s_group_info
= ext4_kvzalloc(array_size
, GFP_KERNEL
);
2337 if (sbi
->s_group_info
== NULL
) {
2338 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy meta group");
2341 sbi
->s_buddy_cache
= new_inode(sb
);
2342 if (sbi
->s_buddy_cache
== NULL
) {
2343 ext4_msg(sb
, KERN_ERR
, "can't get new inode");
2346 /* To avoid potentially colliding with an valid on-disk inode number,
2347 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2348 * not in the inode hash, so it should never be found by iget(), but
2349 * this will avoid confusion if it ever shows up during debugging. */
2350 sbi
->s_buddy_cache
->i_ino
= EXT4_BAD_INO
;
2351 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2352 for (i
= 0; i
< ngroups
; i
++) {
2353 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2355 ext4_msg(sb
, KERN_ERR
, "can't read descriptor %u", i
);
2358 if (ext4_mb_add_groupinfo(sb
, i
, desc
) != 0)
2365 cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2367 kmem_cache_free(cachep
, ext4_get_group_info(sb
, i
));
2368 i
= num_meta_group_infos
;
2370 kfree(sbi
->s_group_info
[i
]);
2371 iput(sbi
->s_buddy_cache
);
2373 ext4_kvfree(sbi
->s_group_info
);
2377 static void ext4_groupinfo_destroy_slabs(void)
2381 for (i
= 0; i
< NR_GRPINFO_CACHES
; i
++) {
2382 if (ext4_groupinfo_caches
[i
])
2383 kmem_cache_destroy(ext4_groupinfo_caches
[i
]);
2384 ext4_groupinfo_caches
[i
] = NULL
;
2388 static int ext4_groupinfo_create_slab(size_t size
)
2390 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex
);
2392 int blocksize_bits
= order_base_2(size
);
2393 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2394 struct kmem_cache
*cachep
;
2396 if (cache_index
>= NR_GRPINFO_CACHES
)
2399 if (unlikely(cache_index
< 0))
2402 mutex_lock(&ext4_grpinfo_slab_create_mutex
);
2403 if (ext4_groupinfo_caches
[cache_index
]) {
2404 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2405 return 0; /* Already created */
2408 slab_size
= offsetof(struct ext4_group_info
,
2409 bb_counters
[blocksize_bits
+ 2]);
2411 cachep
= kmem_cache_create(ext4_groupinfo_slab_names
[cache_index
],
2412 slab_size
, 0, SLAB_RECLAIM_ACCOUNT
,
2415 ext4_groupinfo_caches
[cache_index
] = cachep
;
2417 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2420 "EXT4-fs: no memory for groupinfo slab cache\n");
2427 int ext4_mb_init(struct super_block
*sb
, int needs_recovery
)
2429 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2435 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_offsets
);
2437 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2438 if (sbi
->s_mb_offsets
== NULL
) {
2443 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_maxs
);
2444 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2445 if (sbi
->s_mb_maxs
== NULL
) {
2450 ret
= ext4_groupinfo_create_slab(sb
->s_blocksize
);
2454 /* order 0 is regular bitmap */
2455 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2456 sbi
->s_mb_offsets
[0] = 0;
2460 max
= sb
->s_blocksize
<< 2;
2462 sbi
->s_mb_offsets
[i
] = offset
;
2463 sbi
->s_mb_maxs
[i
] = max
;
2464 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2467 } while (i
<= sb
->s_blocksize_bits
+ 1);
2469 spin_lock_init(&sbi
->s_md_lock
);
2470 spin_lock_init(&sbi
->s_bal_lock
);
2472 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2473 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2474 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2475 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2476 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2478 * The default group preallocation is 512, which for 4k block
2479 * sizes translates to 2 megabytes. However for bigalloc file
2480 * systems, this is probably too big (i.e, if the cluster size
2481 * is 1 megabyte, then group preallocation size becomes half a
2482 * gigabyte!). As a default, we will keep a two megabyte
2483 * group pralloc size for cluster sizes up to 64k, and after
2484 * that, we will force a minimum group preallocation size of
2485 * 32 clusters. This translates to 8 megs when the cluster
2486 * size is 256k, and 32 megs when the cluster size is 1 meg,
2487 * which seems reasonable as a default.
2489 sbi
->s_mb_group_prealloc
= max(MB_DEFAULT_GROUP_PREALLOC
>>
2490 sbi
->s_cluster_bits
, 32);
2492 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2493 * to the lowest multiple of s_stripe which is bigger than
2494 * the s_mb_group_prealloc as determined above. We want
2495 * the preallocation size to be an exact multiple of the
2496 * RAID stripe size so that preallocations don't fragment
2499 if (sbi
->s_stripe
> 1) {
2500 sbi
->s_mb_group_prealloc
= roundup(
2501 sbi
->s_mb_group_prealloc
, sbi
->s_stripe
);
2504 sbi
->s_locality_groups
= alloc_percpu(struct ext4_locality_group
);
2505 if (sbi
->s_locality_groups
== NULL
) {
2507 goto out_free_groupinfo_slab
;
2509 for_each_possible_cpu(i
) {
2510 struct ext4_locality_group
*lg
;
2511 lg
= per_cpu_ptr(sbi
->s_locality_groups
, i
);
2512 mutex_init(&lg
->lg_mutex
);
2513 for (j
= 0; j
< PREALLOC_TB_SIZE
; j
++)
2514 INIT_LIST_HEAD(&lg
->lg_prealloc_list
[j
]);
2515 spin_lock_init(&lg
->lg_prealloc_lock
);
2518 /* init file for buddy data */
2519 ret
= ext4_mb_init_backend(sb
);
2521 goto out_free_locality_groups
;
2524 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_proc
,
2525 &ext4_mb_seq_groups_fops
, sb
);
2528 sbi
->s_journal
->j_commit_callback
= release_blocks_on_commit
;
2532 out_free_locality_groups
:
2533 free_percpu(sbi
->s_locality_groups
);
2534 sbi
->s_locality_groups
= NULL
;
2535 out_free_groupinfo_slab
:
2536 ext4_groupinfo_destroy_slabs();
2538 kfree(sbi
->s_mb_offsets
);
2539 sbi
->s_mb_offsets
= NULL
;
2540 kfree(sbi
->s_mb_maxs
);
2541 sbi
->s_mb_maxs
= NULL
;
2545 /* need to called with the ext4 group lock held */
2546 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2548 struct ext4_prealloc_space
*pa
;
2549 struct list_head
*cur
, *tmp
;
2552 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2553 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2554 list_del(&pa
->pa_group_list
);
2556 kmem_cache_free(ext4_pspace_cachep
, pa
);
2559 mb_debug(1, "mballoc: %u PAs left\n", count
);
2563 int ext4_mb_release(struct super_block
*sb
)
2565 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2567 int num_meta_group_infos
;
2568 struct ext4_group_info
*grinfo
;
2569 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2570 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2572 if (sbi
->s_group_info
) {
2573 for (i
= 0; i
< ngroups
; i
++) {
2574 grinfo
= ext4_get_group_info(sb
, i
);
2576 kfree(grinfo
->bb_bitmap
);
2578 ext4_lock_group(sb
, i
);
2579 ext4_mb_cleanup_pa(grinfo
);
2580 ext4_unlock_group(sb
, i
);
2581 kmem_cache_free(cachep
, grinfo
);
2583 num_meta_group_infos
= (ngroups
+
2584 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2585 EXT4_DESC_PER_BLOCK_BITS(sb
);
2586 for (i
= 0; i
< num_meta_group_infos
; i
++)
2587 kfree(sbi
->s_group_info
[i
]);
2588 ext4_kvfree(sbi
->s_group_info
);
2590 kfree(sbi
->s_mb_offsets
);
2591 kfree(sbi
->s_mb_maxs
);
2592 if (sbi
->s_buddy_cache
)
2593 iput(sbi
->s_buddy_cache
);
2594 if (sbi
->s_mb_stats
) {
2595 ext4_msg(sb
, KERN_INFO
,
2596 "mballoc: %u blocks %u reqs (%u success)",
2597 atomic_read(&sbi
->s_bal_allocated
),
2598 atomic_read(&sbi
->s_bal_reqs
),
2599 atomic_read(&sbi
->s_bal_success
));
2600 ext4_msg(sb
, KERN_INFO
,
2601 "mballoc: %u extents scanned, %u goal hits, "
2602 "%u 2^N hits, %u breaks, %u lost",
2603 atomic_read(&sbi
->s_bal_ex_scanned
),
2604 atomic_read(&sbi
->s_bal_goals
),
2605 atomic_read(&sbi
->s_bal_2orders
),
2606 atomic_read(&sbi
->s_bal_breaks
),
2607 atomic_read(&sbi
->s_mb_lost_chunks
));
2608 ext4_msg(sb
, KERN_INFO
,
2609 "mballoc: %lu generated and it took %Lu",
2610 sbi
->s_mb_buddies_generated
,
2611 sbi
->s_mb_generation_time
);
2612 ext4_msg(sb
, KERN_INFO
,
2613 "mballoc: %u preallocated, %u discarded",
2614 atomic_read(&sbi
->s_mb_preallocated
),
2615 atomic_read(&sbi
->s_mb_discarded
));
2618 free_percpu(sbi
->s_locality_groups
);
2620 remove_proc_entry("mb_groups", sbi
->s_proc
);
2625 static inline int ext4_issue_discard(struct super_block
*sb
,
2626 ext4_group_t block_group
, ext4_grpblk_t cluster
, int count
)
2628 ext4_fsblk_t discard_block
;
2630 discard_block
= (EXT4_C2B(EXT4_SB(sb
), cluster
) +
2631 ext4_group_first_block_no(sb
, block_group
));
2632 count
= EXT4_C2B(EXT4_SB(sb
), count
);
2633 trace_ext4_discard_blocks(sb
,
2634 (unsigned long long) discard_block
, count
);
2635 return sb_issue_discard(sb
, discard_block
, count
, GFP_NOFS
, 0);
2639 * This function is called by the jbd2 layer once the commit has finished,
2640 * so we know we can free the blocks that were released with that commit.
2642 static void release_blocks_on_commit(journal_t
*journal
, transaction_t
*txn
)
2644 struct super_block
*sb
= journal
->j_private
;
2645 struct ext4_buddy e4b
;
2646 struct ext4_group_info
*db
;
2647 int err
, count
= 0, count2
= 0;
2648 struct ext4_free_data
*entry
;
2649 struct list_head
*l
, *ltmp
;
2651 list_for_each_safe(l
, ltmp
, &txn
->t_private_list
) {
2652 entry
= list_entry(l
, struct ext4_free_data
, list
);
2654 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2655 entry
->count
, entry
->group
, entry
);
2657 if (test_opt(sb
, DISCARD
))
2658 ext4_issue_discard(sb
, entry
->group
,
2659 entry
->start_cluster
, entry
->count
);
2661 err
= ext4_mb_load_buddy(sb
, entry
->group
, &e4b
);
2662 /* we expect to find existing buddy because it's pinned */
2666 /* there are blocks to put in buddy to make them really free */
2667 count
+= entry
->count
;
2669 ext4_lock_group(sb
, entry
->group
);
2670 /* Take it out of per group rb tree */
2671 rb_erase(&entry
->node
, &(db
->bb_free_root
));
2672 mb_free_blocks(NULL
, &e4b
, entry
->start_cluster
, entry
->count
);
2675 * Clear the trimmed flag for the group so that the next
2676 * ext4_trim_fs can trim it.
2677 * If the volume is mounted with -o discard, online discard
2678 * is supported and the free blocks will be trimmed online.
2680 if (!test_opt(sb
, DISCARD
))
2681 EXT4_MB_GRP_CLEAR_TRIMMED(db
);
2683 if (!db
->bb_free_root
.rb_node
) {
2684 /* No more items in the per group rb tree
2685 * balance refcounts from ext4_mb_free_metadata()
2687 page_cache_release(e4b
.bd_buddy_page
);
2688 page_cache_release(e4b
.bd_bitmap_page
);
2690 ext4_unlock_group(sb
, entry
->group
);
2691 kmem_cache_free(ext4_free_ext_cachep
, entry
);
2692 ext4_mb_unload_buddy(&e4b
);
2695 mb_debug(1, "freed %u blocks in %u structures\n", count
, count2
);
2698 #ifdef CONFIG_EXT4_DEBUG
2699 u8 mb_enable_debug __read_mostly
;
2701 static struct dentry
*debugfs_dir
;
2702 static struct dentry
*debugfs_debug
;
2704 static void __init
ext4_create_debugfs_entry(void)
2706 debugfs_dir
= debugfs_create_dir("ext4", NULL
);
2708 debugfs_debug
= debugfs_create_u8("mballoc-debug",
2714 static void ext4_remove_debugfs_entry(void)
2716 debugfs_remove(debugfs_debug
);
2717 debugfs_remove(debugfs_dir
);
2722 static void __init
ext4_create_debugfs_entry(void)
2726 static void ext4_remove_debugfs_entry(void)
2732 int __init
ext4_init_mballoc(void)
2734 ext4_pspace_cachep
= KMEM_CACHE(ext4_prealloc_space
,
2735 SLAB_RECLAIM_ACCOUNT
);
2736 if (ext4_pspace_cachep
== NULL
)
2739 ext4_ac_cachep
= KMEM_CACHE(ext4_allocation_context
,
2740 SLAB_RECLAIM_ACCOUNT
);
2741 if (ext4_ac_cachep
== NULL
) {
2742 kmem_cache_destroy(ext4_pspace_cachep
);
2746 ext4_free_ext_cachep
= KMEM_CACHE(ext4_free_data
,
2747 SLAB_RECLAIM_ACCOUNT
);
2748 if (ext4_free_ext_cachep
== NULL
) {
2749 kmem_cache_destroy(ext4_pspace_cachep
);
2750 kmem_cache_destroy(ext4_ac_cachep
);
2753 ext4_create_debugfs_entry();
2757 void ext4_exit_mballoc(void)
2760 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2761 * before destroying the slab cache.
2764 kmem_cache_destroy(ext4_pspace_cachep
);
2765 kmem_cache_destroy(ext4_ac_cachep
);
2766 kmem_cache_destroy(ext4_free_ext_cachep
);
2767 ext4_groupinfo_destroy_slabs();
2768 ext4_remove_debugfs_entry();
2773 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2774 * Returns 0 if success or error code
2776 static noinline_for_stack
int
2777 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2778 handle_t
*handle
, unsigned int reserv_clstrs
)
2780 struct buffer_head
*bitmap_bh
= NULL
;
2781 struct ext4_group_desc
*gdp
;
2782 struct buffer_head
*gdp_bh
;
2783 struct ext4_sb_info
*sbi
;
2784 struct super_block
*sb
;
2788 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2789 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2795 bitmap_bh
= ext4_read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2799 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2804 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2808 ext4_debug("using block group %u(%d)\n", ac
->ac_b_ex
.fe_group
,
2809 ext4_free_group_clusters(sb
, gdp
));
2811 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2815 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
2817 len
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
2818 if (!ext4_data_block_valid(sbi
, block
, len
)) {
2819 ext4_error(sb
, "Allocating blocks %llu-%llu which overlap "
2820 "fs metadata\n", block
, block
+len
);
2821 /* File system mounted not to panic on error
2822 * Fix the bitmap and repeat the block allocation
2823 * We leak some of the blocks here.
2825 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2826 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2827 ac
->ac_b_ex
.fe_len
);
2828 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2829 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2835 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2836 #ifdef AGGRESSIVE_CHECK
2839 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2840 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2841 bitmap_bh
->b_data
));
2845 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2846 ac
->ac_b_ex
.fe_len
);
2847 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2848 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2849 ext4_free_group_clusters_set(sb
, gdp
,
2850 ext4_free_clusters_after_init(sb
,
2851 ac
->ac_b_ex
.fe_group
, gdp
));
2853 len
= ext4_free_group_clusters(sb
, gdp
) - ac
->ac_b_ex
.fe_len
;
2854 ext4_free_group_clusters_set(sb
, gdp
, len
);
2855 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, ac
->ac_b_ex
.fe_group
, gdp
);
2857 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2858 percpu_counter_sub(&sbi
->s_freeclusters_counter
, ac
->ac_b_ex
.fe_len
);
2860 * Now reduce the dirty block count also. Should not go negative
2862 if (!(ac
->ac_flags
& EXT4_MB_DELALLOC_RESERVED
))
2863 /* release all the reserved blocks if non delalloc */
2864 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
2867 if (sbi
->s_log_groups_per_flex
) {
2868 ext4_group_t flex_group
= ext4_flex_group(sbi
,
2869 ac
->ac_b_ex
.fe_group
);
2870 atomic_sub(ac
->ac_b_ex
.fe_len
,
2871 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
2874 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2877 err
= ext4_handle_dirty_metadata(handle
, NULL
, gdp_bh
);
2880 ext4_mark_super_dirty(sb
);
2886 * here we normalize request for locality group
2887 * Group request are normalized to s_mb_group_prealloc, which goes to
2888 * s_strip if we set the same via mount option.
2889 * s_mb_group_prealloc can be configured via
2890 * /sys/fs/ext4/<partition>/mb_group_prealloc
2892 * XXX: should we try to preallocate more than the group has now?
2894 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2896 struct super_block
*sb
= ac
->ac_sb
;
2897 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2900 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2901 mb_debug(1, "#%u: goal %u blocks for locality group\n",
2902 current
->pid
, ac
->ac_g_ex
.fe_len
);
2906 * Normalization means making request better in terms of
2907 * size and alignment
2909 static noinline_for_stack
void
2910 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
2911 struct ext4_allocation_request
*ar
)
2913 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
2916 loff_t size
, orig_size
, start_off
;
2918 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
2919 struct ext4_prealloc_space
*pa
;
2921 /* do normalize only data requests, metadata requests
2922 do not need preallocation */
2923 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
2926 /* sometime caller may want exact blocks */
2927 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2930 /* caller may indicate that preallocation isn't
2931 * required (it's a tail, for example) */
2932 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
2935 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
2936 ext4_mb_normalize_group_request(ac
);
2940 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
2942 /* first, let's learn actual file size
2943 * given current request is allocated */
2944 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
2945 size
= size
<< bsbits
;
2946 if (size
< i_size_read(ac
->ac_inode
))
2947 size
= i_size_read(ac
->ac_inode
);
2950 /* max size of free chunks */
2953 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
2954 (req <= (size) || max <= (chunk_size))
2956 /* first, try to predict filesize */
2957 /* XXX: should this table be tunable? */
2959 if (size
<= 16 * 1024) {
2961 } else if (size
<= 32 * 1024) {
2963 } else if (size
<= 64 * 1024) {
2965 } else if (size
<= 128 * 1024) {
2967 } else if (size
<= 256 * 1024) {
2969 } else if (size
<= 512 * 1024) {
2971 } else if (size
<= 1024 * 1024) {
2973 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
2974 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2975 (21 - bsbits
)) << 21;
2976 size
= 2 * 1024 * 1024;
2977 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
2978 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2979 (22 - bsbits
)) << 22;
2980 size
= 4 * 1024 * 1024;
2981 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
2982 (8<<20)>>bsbits
, max
, 8 * 1024)) {
2983 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
2984 (23 - bsbits
)) << 23;
2985 size
= 8 * 1024 * 1024;
2987 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
2988 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
2990 size
= size
>> bsbits
;
2991 start
= start_off
>> bsbits
;
2993 /* don't cover already allocated blocks in selected range */
2994 if (ar
->pleft
&& start
<= ar
->lleft
) {
2995 size
-= ar
->lleft
+ 1 - start
;
2996 start
= ar
->lleft
+ 1;
2998 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
2999 size
-= start
+ size
- ar
->lright
;
3003 /* check we don't cross already preallocated blocks */
3005 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3010 spin_lock(&pa
->pa_lock
);
3011 if (pa
->pa_deleted
) {
3012 spin_unlock(&pa
->pa_lock
);
3016 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3019 /* PA must not overlap original request */
3020 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
3021 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
3023 /* skip PAs this normalized request doesn't overlap with */
3024 if (pa
->pa_lstart
>= end
|| pa_end
<= start
) {
3025 spin_unlock(&pa
->pa_lock
);
3028 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
3030 /* adjust start or end to be adjacent to this pa */
3031 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
3032 BUG_ON(pa_end
< start
);
3034 } else if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
3035 BUG_ON(pa
->pa_lstart
> end
);
3036 end
= pa
->pa_lstart
;
3038 spin_unlock(&pa
->pa_lock
);
3043 /* XXX: extra loop to check we really don't overlap preallocations */
3045 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3048 spin_lock(&pa
->pa_lock
);
3049 if (pa
->pa_deleted
== 0) {
3050 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3052 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3054 spin_unlock(&pa
->pa_lock
);
3058 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3059 start
> ac
->ac_o_ex
.fe_logical
) {
3060 ext4_msg(ac
->ac_sb
, KERN_ERR
,
3061 "start %lu, size %lu, fe_logical %lu",
3062 (unsigned long) start
, (unsigned long) size
,
3063 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3065 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3066 start
> ac
->ac_o_ex
.fe_logical
);
3067 BUG_ON(size
<= 0 || size
> EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
3069 /* now prepare goal request */
3071 /* XXX: is it better to align blocks WRT to logical
3072 * placement or satisfy big request as is */
3073 ac
->ac_g_ex
.fe_logical
= start
;
3074 ac
->ac_g_ex
.fe_len
= EXT4_NUM_B2C(sbi
, size
);
3076 /* define goal start in order to merge */
3077 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3078 /* merge to the right */
3079 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3080 &ac
->ac_f_ex
.fe_group
,
3081 &ac
->ac_f_ex
.fe_start
);
3082 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3084 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3085 /* merge to the left */
3086 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3087 &ac
->ac_f_ex
.fe_group
,
3088 &ac
->ac_f_ex
.fe_start
);
3089 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3092 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3093 (unsigned) orig_size
, (unsigned) start
);
3096 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3098 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3100 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3101 atomic_inc(&sbi
->s_bal_reqs
);
3102 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3103 if (ac
->ac_b_ex
.fe_len
>= ac
->ac_o_ex
.fe_len
)
3104 atomic_inc(&sbi
->s_bal_success
);
3105 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3106 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3107 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3108 atomic_inc(&sbi
->s_bal_goals
);
3109 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3110 atomic_inc(&sbi
->s_bal_breaks
);
3113 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
)
3114 trace_ext4_mballoc_alloc(ac
);
3116 trace_ext4_mballoc_prealloc(ac
);
3120 * Called on failure; free up any blocks from the inode PA for this
3121 * context. We don't need this for MB_GROUP_PA because we only change
3122 * pa_free in ext4_mb_release_context(), but on failure, we've already
3123 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3125 static void ext4_discard_allocated_blocks(struct ext4_allocation_context
*ac
)
3127 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
3130 if (pa
&& pa
->pa_type
== MB_INODE_PA
) {
3131 len
= ac
->ac_b_ex
.fe_len
;
3138 * use blocks preallocated to inode
3140 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3141 struct ext4_prealloc_space
*pa
)
3143 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3148 /* found preallocated blocks, use them */
3149 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3150 end
= min(pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
),
3151 start
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
));
3152 len
= EXT4_NUM_B2C(sbi
, end
- start
);
3153 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3154 &ac
->ac_b_ex
.fe_start
);
3155 ac
->ac_b_ex
.fe_len
= len
;
3156 ac
->ac_status
= AC_STATUS_FOUND
;
3159 BUG_ON(start
< pa
->pa_pstart
);
3160 BUG_ON(end
> pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
));
3161 BUG_ON(pa
->pa_free
< len
);
3164 mb_debug(1, "use %llu/%u from inode pa %p\n", start
, len
, pa
);
3168 * use blocks preallocated to locality group
3170 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3171 struct ext4_prealloc_space
*pa
)
3173 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3175 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3176 &ac
->ac_b_ex
.fe_group
,
3177 &ac
->ac_b_ex
.fe_start
);
3178 ac
->ac_b_ex
.fe_len
= len
;
3179 ac
->ac_status
= AC_STATUS_FOUND
;
3182 /* we don't correct pa_pstart or pa_plen here to avoid
3183 * possible race when the group is being loaded concurrently
3184 * instead we correct pa later, after blocks are marked
3185 * in on-disk bitmap -- see ext4_mb_release_context()
3186 * Other CPUs are prevented from allocating from this pa by lg_mutex
3188 mb_debug(1, "use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3192 * Return the prealloc space that have minimal distance
3193 * from the goal block. @cpa is the prealloc
3194 * space that is having currently known minimal distance
3195 * from the goal block.
3197 static struct ext4_prealloc_space
*
3198 ext4_mb_check_group_pa(ext4_fsblk_t goal_block
,
3199 struct ext4_prealloc_space
*pa
,
3200 struct ext4_prealloc_space
*cpa
)
3202 ext4_fsblk_t cur_distance
, new_distance
;
3205 atomic_inc(&pa
->pa_count
);
3208 cur_distance
= abs(goal_block
- cpa
->pa_pstart
);
3209 new_distance
= abs(goal_block
- pa
->pa_pstart
);
3211 if (cur_distance
<= new_distance
)
3214 /* drop the previous reference */
3215 atomic_dec(&cpa
->pa_count
);
3216 atomic_inc(&pa
->pa_count
);
3221 * search goal blocks in preallocated space
3223 static noinline_for_stack
int
3224 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3226 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3228 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3229 struct ext4_locality_group
*lg
;
3230 struct ext4_prealloc_space
*pa
, *cpa
= NULL
;
3231 ext4_fsblk_t goal_block
;
3233 /* only data can be preallocated */
3234 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3237 /* first, try per-file preallocation */
3239 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3241 /* all fields in this condition don't change,
3242 * so we can skip locking for them */
3243 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3244 ac
->ac_o_ex
.fe_logical
>= (pa
->pa_lstart
+
3245 EXT4_C2B(sbi
, pa
->pa_len
)))
3248 /* non-extent files can't have physical blocks past 2^32 */
3249 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)) &&
3250 (pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
) >
3251 EXT4_MAX_BLOCK_FILE_PHYS
))
3254 /* found preallocated blocks, use them */
3255 spin_lock(&pa
->pa_lock
);
3256 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3257 atomic_inc(&pa
->pa_count
);
3258 ext4_mb_use_inode_pa(ac
, pa
);
3259 spin_unlock(&pa
->pa_lock
);
3260 ac
->ac_criteria
= 10;
3264 spin_unlock(&pa
->pa_lock
);
3268 /* can we use group allocation? */
3269 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3272 /* inode may have no locality group for some reason */
3276 order
= fls(ac
->ac_o_ex
.fe_len
) - 1;
3277 if (order
> PREALLOC_TB_SIZE
- 1)
3278 /* The max size of hash table is PREALLOC_TB_SIZE */
3279 order
= PREALLOC_TB_SIZE
- 1;
3281 goal_block
= ext4_grp_offs_to_block(ac
->ac_sb
, &ac
->ac_g_ex
);
3283 * search for the prealloc space that is having
3284 * minimal distance from the goal block.
3286 for (i
= order
; i
< PREALLOC_TB_SIZE
; i
++) {
3288 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[i
],
3290 spin_lock(&pa
->pa_lock
);
3291 if (pa
->pa_deleted
== 0 &&
3292 pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3294 cpa
= ext4_mb_check_group_pa(goal_block
,
3297 spin_unlock(&pa
->pa_lock
);
3302 ext4_mb_use_group_pa(ac
, cpa
);
3303 ac
->ac_criteria
= 20;
3310 * the function goes through all block freed in the group
3311 * but not yet committed and marks them used in in-core bitmap.
3312 * buddy must be generated from this bitmap
3313 * Need to be called with the ext4 group lock held
3315 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
3319 struct ext4_group_info
*grp
;
3320 struct ext4_free_data
*entry
;
3322 grp
= ext4_get_group_info(sb
, group
);
3323 n
= rb_first(&(grp
->bb_free_root
));
3326 entry
= rb_entry(n
, struct ext4_free_data
, node
);
3327 ext4_set_bits(bitmap
, entry
->start_cluster
, entry
->count
);
3334 * the function goes through all preallocation in this group and marks them
3335 * used in in-core bitmap. buddy must be generated from this bitmap
3336 * Need to be called with ext4 group lock held
3338 static noinline_for_stack
3339 void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3342 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3343 struct ext4_prealloc_space
*pa
;
3344 struct list_head
*cur
;
3345 ext4_group_t groupnr
;
3346 ext4_grpblk_t start
;
3347 int preallocated
= 0;
3351 /* all form of preallocation discards first load group,
3352 * so the only competing code is preallocation use.
3353 * we don't need any locking here
3354 * notice we do NOT ignore preallocations with pa_deleted
3355 * otherwise we could leave used blocks available for
3356 * allocation in buddy when concurrent ext4_mb_put_pa()
3357 * is dropping preallocation
3359 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3360 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3361 spin_lock(&pa
->pa_lock
);
3362 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3365 spin_unlock(&pa
->pa_lock
);
3366 if (unlikely(len
== 0))
3368 BUG_ON(groupnr
!= group
);
3369 ext4_set_bits(bitmap
, start
, len
);
3370 preallocated
+= len
;
3373 mb_debug(1, "prellocated %u for group %u\n", preallocated
, group
);
3376 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3378 struct ext4_prealloc_space
*pa
;
3379 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3380 kmem_cache_free(ext4_pspace_cachep
, pa
);
3384 * drops a reference to preallocated space descriptor
3385 * if this was the last reference and the space is consumed
3387 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3388 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3391 ext4_fsblk_t grp_blk
;
3393 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0)
3396 /* in this short window concurrent discard can set pa_deleted */
3397 spin_lock(&pa
->pa_lock
);
3398 if (pa
->pa_deleted
== 1) {
3399 spin_unlock(&pa
->pa_lock
);
3404 spin_unlock(&pa
->pa_lock
);
3406 grp_blk
= pa
->pa_pstart
;
3408 * If doing group-based preallocation, pa_pstart may be in the
3409 * next group when pa is used up
3411 if (pa
->pa_type
== MB_GROUP_PA
)
3414 ext4_get_group_no_and_offset(sb
, grp_blk
, &grp
, NULL
);
3419 * P1 (buddy init) P2 (regular allocation)
3420 * find block B in PA
3421 * copy on-disk bitmap to buddy
3422 * mark B in on-disk bitmap
3423 * drop PA from group
3424 * mark all PAs in buddy
3426 * thus, P1 initializes buddy with B available. to prevent this
3427 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3430 ext4_lock_group(sb
, grp
);
3431 list_del(&pa
->pa_group_list
);
3432 ext4_unlock_group(sb
, grp
);
3434 spin_lock(pa
->pa_obj_lock
);
3435 list_del_rcu(&pa
->pa_inode_list
);
3436 spin_unlock(pa
->pa_obj_lock
);
3438 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3442 * creates new preallocated space for given inode
3444 static noinline_for_stack
int
3445 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3447 struct super_block
*sb
= ac
->ac_sb
;
3448 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3449 struct ext4_prealloc_space
*pa
;
3450 struct ext4_group_info
*grp
;
3451 struct ext4_inode_info
*ei
;
3453 /* preallocate only when found space is larger then requested */
3454 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3455 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3456 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3458 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3462 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3468 /* we can't allocate as much as normalizer wants.
3469 * so, found space must get proper lstart
3470 * to cover original request */
3471 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3472 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3474 /* we're limited by original request in that
3475 * logical block must be covered any way
3476 * winl is window we can move our chunk within */
3477 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3479 /* also, we should cover whole original request */
3480 wins
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
);
3482 /* the smallest one defines real window */
3483 win
= min(winl
, wins
);
3485 offs
= ac
->ac_o_ex
.fe_logical
%
3486 EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
3487 if (offs
&& offs
< win
)
3490 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
-
3492 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3493 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3496 /* preallocation can change ac_b_ex, thus we store actually
3497 * allocated blocks for history */
3498 ac
->ac_f_ex
= ac
->ac_b_ex
;
3500 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3501 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3502 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3503 pa
->pa_free
= pa
->pa_len
;
3504 atomic_set(&pa
->pa_count
, 1);
3505 spin_lock_init(&pa
->pa_lock
);
3506 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3507 INIT_LIST_HEAD(&pa
->pa_group_list
);
3509 pa
->pa_type
= MB_INODE_PA
;
3511 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa
,
3512 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3513 trace_ext4_mb_new_inode_pa(ac
, pa
);
3515 ext4_mb_use_inode_pa(ac
, pa
);
3516 atomic_add(pa
->pa_free
, &sbi
->s_mb_preallocated
);
3518 ei
= EXT4_I(ac
->ac_inode
);
3519 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3521 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3522 pa
->pa_inode
= ac
->ac_inode
;
3524 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3525 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3526 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3528 spin_lock(pa
->pa_obj_lock
);
3529 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3530 spin_unlock(pa
->pa_obj_lock
);
3536 * creates new preallocated space for locality group inodes belongs to
3538 static noinline_for_stack
int
3539 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3541 struct super_block
*sb
= ac
->ac_sb
;
3542 struct ext4_locality_group
*lg
;
3543 struct ext4_prealloc_space
*pa
;
3544 struct ext4_group_info
*grp
;
3546 /* preallocate only when found space is larger then requested */
3547 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3548 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3549 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3551 BUG_ON(ext4_pspace_cachep
== NULL
);
3552 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3556 /* preallocation can change ac_b_ex, thus we store actually
3557 * allocated blocks for history */
3558 ac
->ac_f_ex
= ac
->ac_b_ex
;
3560 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3561 pa
->pa_lstart
= pa
->pa_pstart
;
3562 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3563 pa
->pa_free
= pa
->pa_len
;
3564 atomic_set(&pa
->pa_count
, 1);
3565 spin_lock_init(&pa
->pa_lock
);
3566 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3567 INIT_LIST_HEAD(&pa
->pa_group_list
);
3569 pa
->pa_type
= MB_GROUP_PA
;
3571 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa
,
3572 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3573 trace_ext4_mb_new_group_pa(ac
, pa
);
3575 ext4_mb_use_group_pa(ac
, pa
);
3576 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3578 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3582 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3583 pa
->pa_inode
= NULL
;
3585 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3586 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3587 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3590 * We will later add the new pa to the right bucket
3591 * after updating the pa_free in ext4_mb_release_context
3596 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3600 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3601 err
= ext4_mb_new_group_pa(ac
);
3603 err
= ext4_mb_new_inode_pa(ac
);
3608 * finds all unused blocks in on-disk bitmap, frees them in
3609 * in-core bitmap and buddy.
3610 * @pa must be unlinked from inode and group lists, so that
3611 * nobody else can find/use it.
3612 * the caller MUST hold group/inode locks.
3613 * TODO: optimize the case when there are no in-core structures yet
3615 static noinline_for_stack
int
3616 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3617 struct ext4_prealloc_space
*pa
)
3619 struct super_block
*sb
= e4b
->bd_sb
;
3620 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3625 unsigned long long grp_blk_start
;
3629 BUG_ON(pa
->pa_deleted
== 0);
3630 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3631 grp_blk_start
= pa
->pa_pstart
- EXT4_C2B(sbi
, bit
);
3632 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3633 end
= bit
+ pa
->pa_len
;
3636 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3639 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3640 mb_debug(1, " free preallocated %u/%u in group %u\n",
3641 (unsigned) ext4_group_first_block_no(sb
, group
) + bit
,
3642 (unsigned) next
- bit
, (unsigned) group
);
3645 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, next
- bit
);
3646 trace_ext4_mb_release_inode_pa(pa
, (grp_blk_start
+
3647 EXT4_C2B(sbi
, bit
)),
3649 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3652 if (free
!= pa
->pa_free
) {
3653 ext4_msg(e4b
->bd_sb
, KERN_CRIT
,
3654 "pa %p: logic %lu, phys. %lu, len %lu",
3655 pa
, (unsigned long) pa
->pa_lstart
,
3656 (unsigned long) pa
->pa_pstart
,
3657 (unsigned long) pa
->pa_len
);
3658 ext4_grp_locked_error(sb
, group
, 0, 0, "free %u, pa_free %u",
3661 * pa is already deleted so we use the value obtained
3662 * from the bitmap and continue.
3665 atomic_add(free
, &sbi
->s_mb_discarded
);
3670 static noinline_for_stack
int
3671 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3672 struct ext4_prealloc_space
*pa
)
3674 struct super_block
*sb
= e4b
->bd_sb
;
3678 trace_ext4_mb_release_group_pa(pa
);
3679 BUG_ON(pa
->pa_deleted
== 0);
3680 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3681 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3682 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3683 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3684 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, pa
->pa_len
);
3690 * releases all preallocations in given group
3692 * first, we need to decide discard policy:
3693 * - when do we discard
3695 * - how many do we discard
3696 * 1) how many requested
3698 static noinline_for_stack
int
3699 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3700 ext4_group_t group
, int needed
)
3702 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3703 struct buffer_head
*bitmap_bh
= NULL
;
3704 struct ext4_prealloc_space
*pa
, *tmp
;
3705 struct list_head list
;
3706 struct ext4_buddy e4b
;
3711 mb_debug(1, "discard preallocation for group %u\n", group
);
3713 if (list_empty(&grp
->bb_prealloc_list
))
3716 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3717 if (bitmap_bh
== NULL
) {
3718 ext4_error(sb
, "Error reading block bitmap for %u", group
);
3722 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3724 ext4_error(sb
, "Error loading buddy information for %u", group
);
3730 needed
= EXT4_CLUSTERS_PER_GROUP(sb
) + 1;
3732 INIT_LIST_HEAD(&list
);
3734 ext4_lock_group(sb
, group
);
3735 list_for_each_entry_safe(pa
, tmp
,
3736 &grp
->bb_prealloc_list
, pa_group_list
) {
3737 spin_lock(&pa
->pa_lock
);
3738 if (atomic_read(&pa
->pa_count
)) {
3739 spin_unlock(&pa
->pa_lock
);
3743 if (pa
->pa_deleted
) {
3744 spin_unlock(&pa
->pa_lock
);
3748 /* seems this one can be freed ... */
3751 /* we can trust pa_free ... */
3752 free
+= pa
->pa_free
;
3754 spin_unlock(&pa
->pa_lock
);
3756 list_del(&pa
->pa_group_list
);
3757 list_add(&pa
->u
.pa_tmp_list
, &list
);
3760 /* if we still need more blocks and some PAs were used, try again */
3761 if (free
< needed
&& busy
) {
3763 ext4_unlock_group(sb
, group
);
3765 * Yield the CPU here so that we don't get soft lockup
3766 * in non preempt case.
3772 /* found anything to free? */
3773 if (list_empty(&list
)) {
3778 /* now free all selected PAs */
3779 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3781 /* remove from object (inode or locality group) */
3782 spin_lock(pa
->pa_obj_lock
);
3783 list_del_rcu(&pa
->pa_inode_list
);
3784 spin_unlock(pa
->pa_obj_lock
);
3786 if (pa
->pa_type
== MB_GROUP_PA
)
3787 ext4_mb_release_group_pa(&e4b
, pa
);
3789 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3791 list_del(&pa
->u
.pa_tmp_list
);
3792 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3796 ext4_unlock_group(sb
, group
);
3797 ext4_mb_unload_buddy(&e4b
);
3803 * releases all non-used preallocated blocks for given inode
3805 * It's important to discard preallocations under i_data_sem
3806 * We don't want another block to be served from the prealloc
3807 * space when we are discarding the inode prealloc space.
3809 * FIXME!! Make sure it is valid at all the call sites
3811 void ext4_discard_preallocations(struct inode
*inode
)
3813 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3814 struct super_block
*sb
= inode
->i_sb
;
3815 struct buffer_head
*bitmap_bh
= NULL
;
3816 struct ext4_prealloc_space
*pa
, *tmp
;
3817 ext4_group_t group
= 0;
3818 struct list_head list
;
3819 struct ext4_buddy e4b
;
3822 if (!S_ISREG(inode
->i_mode
)) {
3823 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3827 mb_debug(1, "discard preallocation for inode %lu\n", inode
->i_ino
);
3828 trace_ext4_discard_preallocations(inode
);
3830 INIT_LIST_HEAD(&list
);
3833 /* first, collect all pa's in the inode */
3834 spin_lock(&ei
->i_prealloc_lock
);
3835 while (!list_empty(&ei
->i_prealloc_list
)) {
3836 pa
= list_entry(ei
->i_prealloc_list
.next
,
3837 struct ext4_prealloc_space
, pa_inode_list
);
3838 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3839 spin_lock(&pa
->pa_lock
);
3840 if (atomic_read(&pa
->pa_count
)) {
3841 /* this shouldn't happen often - nobody should
3842 * use preallocation while we're discarding it */
3843 spin_unlock(&pa
->pa_lock
);
3844 spin_unlock(&ei
->i_prealloc_lock
);
3845 ext4_msg(sb
, KERN_ERR
,
3846 "uh-oh! used pa while discarding");
3848 schedule_timeout_uninterruptible(HZ
);
3852 if (pa
->pa_deleted
== 0) {
3854 spin_unlock(&pa
->pa_lock
);
3855 list_del_rcu(&pa
->pa_inode_list
);
3856 list_add(&pa
->u
.pa_tmp_list
, &list
);
3860 /* someone is deleting pa right now */
3861 spin_unlock(&pa
->pa_lock
);
3862 spin_unlock(&ei
->i_prealloc_lock
);
3864 /* we have to wait here because pa_deleted
3865 * doesn't mean pa is already unlinked from
3866 * the list. as we might be called from
3867 * ->clear_inode() the inode will get freed
3868 * and concurrent thread which is unlinking
3869 * pa from inode's list may access already
3870 * freed memory, bad-bad-bad */
3872 /* XXX: if this happens too often, we can
3873 * add a flag to force wait only in case
3874 * of ->clear_inode(), but not in case of
3875 * regular truncate */
3876 schedule_timeout_uninterruptible(HZ
);
3879 spin_unlock(&ei
->i_prealloc_lock
);
3881 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3882 BUG_ON(pa
->pa_type
!= MB_INODE_PA
);
3883 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
3885 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3887 ext4_error(sb
, "Error loading buddy information for %u",
3892 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3893 if (bitmap_bh
== NULL
) {
3894 ext4_error(sb
, "Error reading block bitmap for %u",
3896 ext4_mb_unload_buddy(&e4b
);
3900 ext4_lock_group(sb
, group
);
3901 list_del(&pa
->pa_group_list
);
3902 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3903 ext4_unlock_group(sb
, group
);
3905 ext4_mb_unload_buddy(&e4b
);
3908 list_del(&pa
->u
.pa_tmp_list
);
3909 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3913 #ifdef CONFIG_EXT4_DEBUG
3914 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3916 struct super_block
*sb
= ac
->ac_sb
;
3917 ext4_group_t ngroups
, i
;
3919 if (!mb_enable_debug
||
3920 (EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
))
3923 ext4_msg(ac
->ac_sb
, KERN_ERR
, "EXT4-fs: Can't allocate:"
3924 " Allocation context details:");
3925 ext4_msg(ac
->ac_sb
, KERN_ERR
, "EXT4-fs: status %d flags %d",
3926 ac
->ac_status
, ac
->ac_flags
);
3927 ext4_msg(ac
->ac_sb
, KERN_ERR
, "EXT4-fs: orig %lu/%lu/%lu@%lu, "
3928 "goal %lu/%lu/%lu@%lu, "
3929 "best %lu/%lu/%lu@%lu cr %d",
3930 (unsigned long)ac
->ac_o_ex
.fe_group
,
3931 (unsigned long)ac
->ac_o_ex
.fe_start
,
3932 (unsigned long)ac
->ac_o_ex
.fe_len
,
3933 (unsigned long)ac
->ac_o_ex
.fe_logical
,
3934 (unsigned long)ac
->ac_g_ex
.fe_group
,
3935 (unsigned long)ac
->ac_g_ex
.fe_start
,
3936 (unsigned long)ac
->ac_g_ex
.fe_len
,
3937 (unsigned long)ac
->ac_g_ex
.fe_logical
,
3938 (unsigned long)ac
->ac_b_ex
.fe_group
,
3939 (unsigned long)ac
->ac_b_ex
.fe_start
,
3940 (unsigned long)ac
->ac_b_ex
.fe_len
,
3941 (unsigned long)ac
->ac_b_ex
.fe_logical
,
3942 (int)ac
->ac_criteria
);
3943 ext4_msg(ac
->ac_sb
, KERN_ERR
, "EXT4-fs: %lu scanned, %d found",
3944 ac
->ac_ex_scanned
, ac
->ac_found
);
3945 ext4_msg(ac
->ac_sb
, KERN_ERR
, "EXT4-fs: groups: ");
3946 ngroups
= ext4_get_groups_count(sb
);
3947 for (i
= 0; i
< ngroups
; i
++) {
3948 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
3949 struct ext4_prealloc_space
*pa
;
3950 ext4_grpblk_t start
;
3951 struct list_head
*cur
;
3952 ext4_lock_group(sb
, i
);
3953 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3954 pa
= list_entry(cur
, struct ext4_prealloc_space
,
3956 spin_lock(&pa
->pa_lock
);
3957 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3959 spin_unlock(&pa
->pa_lock
);
3960 printk(KERN_ERR
"PA:%u:%d:%u \n", i
,
3963 ext4_unlock_group(sb
, i
);
3965 if (grp
->bb_free
== 0)
3967 printk(KERN_ERR
"%u: %d/%d \n",
3968 i
, grp
->bb_free
, grp
->bb_fragments
);
3970 printk(KERN_ERR
"\n");
3973 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3980 * We use locality group preallocation for small size file. The size of the
3981 * file is determined by the current size or the resulting size after
3982 * allocation which ever is larger
3984 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
3986 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
3988 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3989 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3992 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3995 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3998 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
3999 isize
= (i_size_read(ac
->ac_inode
) + ac
->ac_sb
->s_blocksize
- 1)
4002 if ((size
== isize
) &&
4003 !ext4_fs_is_busy(sbi
) &&
4004 (atomic_read(&ac
->ac_inode
->i_writecount
) == 0)) {
4005 ac
->ac_flags
|= EXT4_MB_HINT_NOPREALLOC
;
4009 /* don't use group allocation for large files */
4010 size
= max(size
, isize
);
4011 if (size
> sbi
->s_mb_stream_request
) {
4012 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4016 BUG_ON(ac
->ac_lg
!= NULL
);
4018 * locality group prealloc space are per cpu. The reason for having
4019 * per cpu locality group is to reduce the contention between block
4020 * request from multiple CPUs.
4022 ac
->ac_lg
= __this_cpu_ptr(sbi
->s_locality_groups
);
4024 /* we're going to use group allocation */
4025 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
4027 /* serialize all allocations in the group */
4028 mutex_lock(&ac
->ac_lg
->lg_mutex
);
4031 static noinline_for_stack
int
4032 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
4033 struct ext4_allocation_request
*ar
)
4035 struct super_block
*sb
= ar
->inode
->i_sb
;
4036 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4037 struct ext4_super_block
*es
= sbi
->s_es
;
4041 ext4_grpblk_t block
;
4043 /* we can't allocate > group size */
4046 /* just a dirty hack to filter too big requests */
4047 if (len
>= EXT4_CLUSTERS_PER_GROUP(sb
) - 10)
4048 len
= EXT4_CLUSTERS_PER_GROUP(sb
) - 10;
4050 /* start searching from the goal */
4052 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
4053 goal
>= ext4_blocks_count(es
))
4054 goal
= le32_to_cpu(es
->s_first_data_block
);
4055 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
4057 /* set up allocation goals */
4058 memset(ac
, 0, sizeof(struct ext4_allocation_context
));
4059 ac
->ac_b_ex
.fe_logical
= ar
->logical
& ~(sbi
->s_cluster_ratio
- 1);
4060 ac
->ac_status
= AC_STATUS_CONTINUE
;
4062 ac
->ac_inode
= ar
->inode
;
4063 ac
->ac_o_ex
.fe_logical
= ac
->ac_b_ex
.fe_logical
;
4064 ac
->ac_o_ex
.fe_group
= group
;
4065 ac
->ac_o_ex
.fe_start
= block
;
4066 ac
->ac_o_ex
.fe_len
= len
;
4067 ac
->ac_g_ex
= ac
->ac_o_ex
;
4068 ac
->ac_flags
= ar
->flags
;
4070 /* we have to define context: we'll we work with a file or
4071 * locality group. this is a policy, actually */
4072 ext4_mb_group_or_file(ac
);
4074 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4075 "left: %u/%u, right %u/%u to %swritable\n",
4076 (unsigned) ar
->len
, (unsigned) ar
->logical
,
4077 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
4078 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
4079 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
4080 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
4085 static noinline_for_stack
void
4086 ext4_mb_discard_lg_preallocations(struct super_block
*sb
,
4087 struct ext4_locality_group
*lg
,
4088 int order
, int total_entries
)
4090 ext4_group_t group
= 0;
4091 struct ext4_buddy e4b
;
4092 struct list_head discard_list
;
4093 struct ext4_prealloc_space
*pa
, *tmp
;
4095 mb_debug(1, "discard locality group preallocation\n");
4097 INIT_LIST_HEAD(&discard_list
);
4099 spin_lock(&lg
->lg_prealloc_lock
);
4100 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[order
],
4102 spin_lock(&pa
->pa_lock
);
4103 if (atomic_read(&pa
->pa_count
)) {
4105 * This is the pa that we just used
4106 * for block allocation. So don't
4109 spin_unlock(&pa
->pa_lock
);
4112 if (pa
->pa_deleted
) {
4113 spin_unlock(&pa
->pa_lock
);
4116 /* only lg prealloc space */
4117 BUG_ON(pa
->pa_type
!= MB_GROUP_PA
);
4119 /* seems this one can be freed ... */
4121 spin_unlock(&pa
->pa_lock
);
4123 list_del_rcu(&pa
->pa_inode_list
);
4124 list_add(&pa
->u
.pa_tmp_list
, &discard_list
);
4127 if (total_entries
<= 5) {
4129 * we want to keep only 5 entries
4130 * allowing it to grow to 8. This
4131 * mak sure we don't call discard
4132 * soon for this list.
4137 spin_unlock(&lg
->lg_prealloc_lock
);
4139 list_for_each_entry_safe(pa
, tmp
, &discard_list
, u
.pa_tmp_list
) {
4141 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, NULL
);
4142 if (ext4_mb_load_buddy(sb
, group
, &e4b
)) {
4143 ext4_error(sb
, "Error loading buddy information for %u",
4147 ext4_lock_group(sb
, group
);
4148 list_del(&pa
->pa_group_list
);
4149 ext4_mb_release_group_pa(&e4b
, pa
);
4150 ext4_unlock_group(sb
, group
);
4152 ext4_mb_unload_buddy(&e4b
);
4153 list_del(&pa
->u
.pa_tmp_list
);
4154 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4159 * We have incremented pa_count. So it cannot be freed at this
4160 * point. Also we hold lg_mutex. So no parallel allocation is
4161 * possible from this lg. That means pa_free cannot be updated.
4163 * A parallel ext4_mb_discard_group_preallocations is possible.
4164 * which can cause the lg_prealloc_list to be updated.
4167 static void ext4_mb_add_n_trim(struct ext4_allocation_context
*ac
)
4169 int order
, added
= 0, lg_prealloc_count
= 1;
4170 struct super_block
*sb
= ac
->ac_sb
;
4171 struct ext4_locality_group
*lg
= ac
->ac_lg
;
4172 struct ext4_prealloc_space
*tmp_pa
, *pa
= ac
->ac_pa
;
4174 order
= fls(pa
->pa_free
) - 1;
4175 if (order
> PREALLOC_TB_SIZE
- 1)
4176 /* The max size of hash table is PREALLOC_TB_SIZE */
4177 order
= PREALLOC_TB_SIZE
- 1;
4178 /* Add the prealloc space to lg */
4180 list_for_each_entry_rcu(tmp_pa
, &lg
->lg_prealloc_list
[order
],
4182 spin_lock(&tmp_pa
->pa_lock
);
4183 if (tmp_pa
->pa_deleted
) {
4184 spin_unlock(&tmp_pa
->pa_lock
);
4187 if (!added
&& pa
->pa_free
< tmp_pa
->pa_free
) {
4188 /* Add to the tail of the previous entry */
4189 list_add_tail_rcu(&pa
->pa_inode_list
,
4190 &tmp_pa
->pa_inode_list
);
4193 * we want to count the total
4194 * number of entries in the list
4197 spin_unlock(&tmp_pa
->pa_lock
);
4198 lg_prealloc_count
++;
4201 list_add_tail_rcu(&pa
->pa_inode_list
,
4202 &lg
->lg_prealloc_list
[order
]);
4205 /* Now trim the list to be not more than 8 elements */
4206 if (lg_prealloc_count
> 8) {
4207 ext4_mb_discard_lg_preallocations(sb
, lg
,
4208 order
, lg_prealloc_count
);
4215 * release all resource we used in allocation
4217 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
4219 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4220 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
4222 if (pa
->pa_type
== MB_GROUP_PA
) {
4223 /* see comment in ext4_mb_use_group_pa() */
4224 spin_lock(&pa
->pa_lock
);
4225 pa
->pa_pstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4226 pa
->pa_lstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4227 pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
4228 pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
4229 spin_unlock(&pa
->pa_lock
);
4234 * We want to add the pa to the right bucket.
4235 * Remove it from the list and while adding
4236 * make sure the list to which we are adding
4239 if ((pa
->pa_type
== MB_GROUP_PA
) && likely(pa
->pa_free
)) {
4240 spin_lock(pa
->pa_obj_lock
);
4241 list_del_rcu(&pa
->pa_inode_list
);
4242 spin_unlock(pa
->pa_obj_lock
);
4243 ext4_mb_add_n_trim(ac
);
4245 ext4_mb_put_pa(ac
, ac
->ac_sb
, pa
);
4247 if (ac
->ac_bitmap_page
)
4248 page_cache_release(ac
->ac_bitmap_page
);
4249 if (ac
->ac_buddy_page
)
4250 page_cache_release(ac
->ac_buddy_page
);
4251 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
4252 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
4253 ext4_mb_collect_stats(ac
);
4257 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
4259 ext4_group_t i
, ngroups
= ext4_get_groups_count(sb
);
4263 trace_ext4_mb_discard_preallocations(sb
, needed
);
4264 for (i
= 0; i
< ngroups
&& needed
> 0; i
++) {
4265 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4274 * Main entry point into mballoc to allocate blocks
4275 * it tries to use preallocation first, then falls back
4276 * to usual allocation
4278 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4279 struct ext4_allocation_request
*ar
, int *errp
)
4282 struct ext4_allocation_context
*ac
= NULL
;
4283 struct ext4_sb_info
*sbi
;
4284 struct super_block
*sb
;
4285 ext4_fsblk_t block
= 0;
4286 unsigned int inquota
= 0;
4287 unsigned int reserv_clstrs
= 0;
4289 sb
= ar
->inode
->i_sb
;
4292 trace_ext4_request_blocks(ar
);
4294 /* Allow to use superuser reservation for quota file */
4295 if (IS_NOQUOTA(ar
->inode
))
4296 ar
->flags
|= EXT4_MB_USE_ROOT_BLOCKS
;
4299 * For delayed allocation, we could skip the ENOSPC and
4300 * EDQUOT check, as blocks and quotas have been already
4301 * reserved when data being copied into pagecache.
4303 if (ext4_test_inode_state(ar
->inode
, EXT4_STATE_DELALLOC_RESERVED
))
4304 ar
->flags
|= EXT4_MB_DELALLOC_RESERVED
;
4306 /* Without delayed allocation we need to verify
4307 * there is enough free blocks to do block allocation
4308 * and verify allocation doesn't exceed the quota limits.
4311 ext4_claim_free_clusters(sbi
, ar
->len
, ar
->flags
)) {
4313 /* let others to free the space */
4315 ar
->len
= ar
->len
>> 1;
4321 reserv_clstrs
= ar
->len
;
4322 if (ar
->flags
& EXT4_MB_USE_ROOT_BLOCKS
) {
4323 dquot_alloc_block_nofail(ar
->inode
,
4324 EXT4_C2B(sbi
, ar
->len
));
4327 dquot_alloc_block(ar
->inode
,
4328 EXT4_C2B(sbi
, ar
->len
))) {
4330 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4341 ac
= kmem_cache_alloc(ext4_ac_cachep
, GFP_NOFS
);
4348 *errp
= ext4_mb_initialize_context(ac
, ar
);
4354 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4355 if (!ext4_mb_use_preallocated(ac
)) {
4356 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4357 ext4_mb_normalize_request(ac
, ar
);
4359 /* allocate space in core */
4360 *errp
= ext4_mb_regular_allocator(ac
);
4364 /* as we've just preallocated more space than
4365 * user requested orinally, we store allocated
4366 * space in a special descriptor */
4367 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4368 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4369 ext4_mb_new_preallocation(ac
);
4371 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4372 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
, reserv_clstrs
);
4373 if (*errp
== -EAGAIN
) {
4375 * drop the reference that we took
4376 * in ext4_mb_use_best_found
4378 ext4_mb_release_context(ac
);
4379 ac
->ac_b_ex
.fe_group
= 0;
4380 ac
->ac_b_ex
.fe_start
= 0;
4381 ac
->ac_b_ex
.fe_len
= 0;
4382 ac
->ac_status
= AC_STATUS_CONTINUE
;
4386 ext4_discard_allocated_blocks(ac
);
4388 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4389 ar
->len
= ac
->ac_b_ex
.fe_len
;
4392 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4399 ac
->ac_b_ex
.fe_len
= 0;
4401 ext4_mb_show_ac(ac
);
4403 ext4_mb_release_context(ac
);
4406 kmem_cache_free(ext4_ac_cachep
, ac
);
4407 if (inquota
&& ar
->len
< inquota
)
4408 dquot_free_block(ar
->inode
, EXT4_C2B(sbi
, inquota
- ar
->len
));
4410 if (!ext4_test_inode_state(ar
->inode
,
4411 EXT4_STATE_DELALLOC_RESERVED
))
4412 /* release all the reserved blocks if non delalloc */
4413 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
4417 trace_ext4_allocate_blocks(ar
, (unsigned long long)block
);
4423 * We can merge two free data extents only if the physical blocks
4424 * are contiguous, AND the extents were freed by the same transaction,
4425 * AND the blocks are associated with the same group.
4427 static int can_merge(struct ext4_free_data
*entry1
,
4428 struct ext4_free_data
*entry2
)
4430 if ((entry1
->t_tid
== entry2
->t_tid
) &&
4431 (entry1
->group
== entry2
->group
) &&
4432 ((entry1
->start_cluster
+ entry1
->count
) == entry2
->start_cluster
))
4437 static noinline_for_stack
int
4438 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4439 struct ext4_free_data
*new_entry
)
4441 ext4_group_t group
= e4b
->bd_group
;
4442 ext4_grpblk_t cluster
;
4443 struct ext4_free_data
*entry
;
4444 struct ext4_group_info
*db
= e4b
->bd_info
;
4445 struct super_block
*sb
= e4b
->bd_sb
;
4446 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4447 struct rb_node
**n
= &db
->bb_free_root
.rb_node
, *node
;
4448 struct rb_node
*parent
= NULL
, *new_node
;
4450 BUG_ON(!ext4_handle_valid(handle
));
4451 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4452 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4454 new_node
= &new_entry
->node
;
4455 cluster
= new_entry
->start_cluster
;
4458 /* first free block exent. We need to
4459 protect buddy cache from being freed,
4460 * otherwise we'll refresh it from
4461 * on-disk bitmap and lose not-yet-available
4463 page_cache_get(e4b
->bd_buddy_page
);
4464 page_cache_get(e4b
->bd_bitmap_page
);
4468 entry
= rb_entry(parent
, struct ext4_free_data
, node
);
4469 if (cluster
< entry
->start_cluster
)
4471 else if (cluster
>= (entry
->start_cluster
+ entry
->count
))
4472 n
= &(*n
)->rb_right
;
4474 ext4_grp_locked_error(sb
, group
, 0,
4475 ext4_group_first_block_no(sb
, group
) +
4476 EXT4_C2B(sbi
, cluster
),
4477 "Block already on to-be-freed list");
4482 rb_link_node(new_node
, parent
, n
);
4483 rb_insert_color(new_node
, &db
->bb_free_root
);
4485 /* Now try to see the extent can be merged to left and right */
4486 node
= rb_prev(new_node
);
4488 entry
= rb_entry(node
, struct ext4_free_data
, node
);
4489 if (can_merge(entry
, new_entry
)) {
4490 new_entry
->start_cluster
= entry
->start_cluster
;
4491 new_entry
->count
+= entry
->count
;
4492 rb_erase(node
, &(db
->bb_free_root
));
4493 spin_lock(&sbi
->s_md_lock
);
4494 list_del(&entry
->list
);
4495 spin_unlock(&sbi
->s_md_lock
);
4496 kmem_cache_free(ext4_free_ext_cachep
, entry
);
4500 node
= rb_next(new_node
);
4502 entry
= rb_entry(node
, struct ext4_free_data
, node
);
4503 if (can_merge(new_entry
, entry
)) {
4504 new_entry
->count
+= entry
->count
;
4505 rb_erase(node
, &(db
->bb_free_root
));
4506 spin_lock(&sbi
->s_md_lock
);
4507 list_del(&entry
->list
);
4508 spin_unlock(&sbi
->s_md_lock
);
4509 kmem_cache_free(ext4_free_ext_cachep
, entry
);
4512 /* Add the extent to transaction's private list */
4513 spin_lock(&sbi
->s_md_lock
);
4514 list_add(&new_entry
->list
, &handle
->h_transaction
->t_private_list
);
4515 spin_unlock(&sbi
->s_md_lock
);
4520 * ext4_free_blocks() -- Free given blocks and update quota
4521 * @handle: handle for this transaction
4523 * @block: start physical block to free
4524 * @count: number of blocks to count
4525 * @flags: flags used by ext4_free_blocks
4527 void ext4_free_blocks(handle_t
*handle
, struct inode
*inode
,
4528 struct buffer_head
*bh
, ext4_fsblk_t block
,
4529 unsigned long count
, int flags
)
4531 struct buffer_head
*bitmap_bh
= NULL
;
4532 struct super_block
*sb
= inode
->i_sb
;
4533 struct ext4_group_desc
*gdp
;
4534 unsigned long freed
= 0;
4535 unsigned int overflow
;
4537 struct buffer_head
*gd_bh
;
4538 ext4_group_t block_group
;
4539 struct ext4_sb_info
*sbi
;
4540 struct ext4_buddy e4b
;
4541 unsigned int count_clusters
;
4547 BUG_ON(block
!= bh
->b_blocknr
);
4549 block
= bh
->b_blocknr
;
4553 if (!(flags
& EXT4_FREE_BLOCKS_VALIDATED
) &&
4554 !ext4_data_block_valid(sbi
, block
, count
)) {
4555 ext4_error(sb
, "Freeing blocks not in datazone - "
4556 "block = %llu, count = %lu", block
, count
);
4560 ext4_debug("freeing block %llu\n", block
);
4561 trace_ext4_free_blocks(inode
, block
, count
, flags
);
4563 if (flags
& EXT4_FREE_BLOCKS_FORGET
) {
4564 struct buffer_head
*tbh
= bh
;
4567 BUG_ON(bh
&& (count
> 1));
4569 for (i
= 0; i
< count
; i
++) {
4571 tbh
= sb_find_get_block(inode
->i_sb
,
4575 ext4_forget(handle
, flags
& EXT4_FREE_BLOCKS_METADATA
,
4576 inode
, tbh
, block
+ i
);
4581 * We need to make sure we don't reuse the freed block until
4582 * after the transaction is committed, which we can do by
4583 * treating the block as metadata, below. We make an
4584 * exception if the inode is to be written in writeback mode
4585 * since writeback mode has weak data consistency guarantees.
4587 if (!ext4_should_writeback_data(inode
))
4588 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4591 * If the extent to be freed does not begin on a cluster
4592 * boundary, we need to deal with partial clusters at the
4593 * beginning and end of the extent. Normally we will free
4594 * blocks at the beginning or the end unless we are explicitly
4595 * requested to avoid doing so.
4597 overflow
= block
& (sbi
->s_cluster_ratio
- 1);
4599 if (flags
& EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER
) {
4600 overflow
= sbi
->s_cluster_ratio
- overflow
;
4602 if (count
> overflow
)
4611 overflow
= count
& (sbi
->s_cluster_ratio
- 1);
4613 if (flags
& EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER
) {
4614 if (count
> overflow
)
4619 count
+= sbi
->s_cluster_ratio
- overflow
;
4624 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4627 * Check to see if we are freeing blocks across a group
4630 if (EXT4_C2B(sbi
, bit
) + count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4631 overflow
= EXT4_C2B(sbi
, bit
) + count
-
4632 EXT4_BLOCKS_PER_GROUP(sb
);
4635 count_clusters
= EXT4_B2C(sbi
, count
);
4636 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4641 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4647 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4648 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4649 in_range(block
, ext4_inode_table(sb
, gdp
),
4650 EXT4_SB(sb
)->s_itb_per_group
) ||
4651 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4652 EXT4_SB(sb
)->s_itb_per_group
)) {
4654 ext4_error(sb
, "Freeing blocks in system zone - "
4655 "Block = %llu, count = %lu", block
, count
);
4656 /* err = 0. ext4_std_error should be a no op */
4660 BUFFER_TRACE(bitmap_bh
, "getting write access");
4661 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4666 * We are about to modify some metadata. Call the journal APIs
4667 * to unshare ->b_data if a currently-committing transaction is
4670 BUFFER_TRACE(gd_bh
, "get_write_access");
4671 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4674 #ifdef AGGRESSIVE_CHECK
4677 for (i
= 0; i
< count_clusters
; i
++)
4678 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4681 trace_ext4_mballoc_free(sb
, inode
, block_group
, bit
, count_clusters
);
4683 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4687 if ((flags
& EXT4_FREE_BLOCKS_METADATA
) && ext4_handle_valid(handle
)) {
4688 struct ext4_free_data
*new_entry
;
4690 * blocks being freed are metadata. these blocks shouldn't
4691 * be used until this transaction is committed
4693 new_entry
= kmem_cache_alloc(ext4_free_ext_cachep
, GFP_NOFS
);
4698 new_entry
->start_cluster
= bit
;
4699 new_entry
->group
= block_group
;
4700 new_entry
->count
= count_clusters
;
4701 new_entry
->t_tid
= handle
->h_transaction
->t_tid
;
4703 ext4_lock_group(sb
, block_group
);
4704 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4705 ext4_mb_free_metadata(handle
, &e4b
, new_entry
);
4707 /* need to update group_info->bb_free and bitmap
4708 * with group lock held. generate_buddy look at
4709 * them with group lock_held
4711 ext4_lock_group(sb
, block_group
);
4712 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4713 mb_free_blocks(inode
, &e4b
, bit
, count_clusters
);
4716 ret
= ext4_free_group_clusters(sb
, gdp
) + count_clusters
;
4717 ext4_free_group_clusters_set(sb
, gdp
, ret
);
4718 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, block_group
, gdp
);
4719 ext4_unlock_group(sb
, block_group
);
4720 percpu_counter_add(&sbi
->s_freeclusters_counter
, count_clusters
);
4722 if (sbi
->s_log_groups_per_flex
) {
4723 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4724 atomic_add(count_clusters
,
4725 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4728 ext4_mb_unload_buddy(&e4b
);
4732 if (!(flags
& EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
))
4733 dquot_free_block(inode
, EXT4_C2B(sbi
, count_clusters
));
4735 /* We dirtied the bitmap block */
4736 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4737 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4739 /* And the group descriptor block */
4740 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4741 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4745 if (overflow
&& !err
) {
4751 ext4_mark_super_dirty(sb
);
4754 ext4_std_error(sb
, err
);
4759 * ext4_group_add_blocks() -- Add given blocks to an existing group
4760 * @handle: handle to this transaction
4762 * @block: start physcial block to add to the block group
4763 * @count: number of blocks to free
4765 * This marks the blocks as free in the bitmap and buddy.
4767 int ext4_group_add_blocks(handle_t
*handle
, struct super_block
*sb
,
4768 ext4_fsblk_t block
, unsigned long count
)
4770 struct buffer_head
*bitmap_bh
= NULL
;
4771 struct buffer_head
*gd_bh
;
4772 ext4_group_t block_group
;
4775 struct ext4_group_desc
*desc
;
4776 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4777 struct ext4_buddy e4b
;
4778 int err
= 0, ret
, blk_free_count
;
4779 ext4_grpblk_t blocks_freed
;
4781 ext4_debug("Adding block(s) %llu-%llu\n", block
, block
+ count
- 1);
4786 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4788 * Check to see if we are freeing blocks across a group
4791 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4792 ext4_warning(sb
, "too much blocks added to group %u\n",
4798 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4804 desc
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4810 if (in_range(ext4_block_bitmap(sb
, desc
), block
, count
) ||
4811 in_range(ext4_inode_bitmap(sb
, desc
), block
, count
) ||
4812 in_range(block
, ext4_inode_table(sb
, desc
), sbi
->s_itb_per_group
) ||
4813 in_range(block
+ count
- 1, ext4_inode_table(sb
, desc
),
4814 sbi
->s_itb_per_group
)) {
4815 ext4_error(sb
, "Adding blocks in system zones - "
4816 "Block = %llu, count = %lu",
4822 BUFFER_TRACE(bitmap_bh
, "getting write access");
4823 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4828 * We are about to modify some metadata. Call the journal APIs
4829 * to unshare ->b_data if a currently-committing transaction is
4832 BUFFER_TRACE(gd_bh
, "get_write_access");
4833 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4837 for (i
= 0, blocks_freed
= 0; i
< count
; i
++) {
4838 BUFFER_TRACE(bitmap_bh
, "clear bit");
4839 if (!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
)) {
4840 ext4_error(sb
, "bit already cleared for block %llu",
4841 (ext4_fsblk_t
)(block
+ i
));
4842 BUFFER_TRACE(bitmap_bh
, "bit already cleared");
4848 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4853 * need to update group_info->bb_free and bitmap
4854 * with group lock held. generate_buddy look at
4855 * them with group lock_held
4857 ext4_lock_group(sb
, block_group
);
4858 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4859 mb_free_blocks(NULL
, &e4b
, bit
, count
);
4860 blk_free_count
= blocks_freed
+ ext4_free_group_clusters(sb
, desc
);
4861 ext4_free_group_clusters_set(sb
, desc
, blk_free_count
);
4862 desc
->bg_checksum
= ext4_group_desc_csum(sbi
, block_group
, desc
);
4863 ext4_unlock_group(sb
, block_group
);
4864 percpu_counter_add(&sbi
->s_freeclusters_counter
,
4865 EXT4_B2C(sbi
, blocks_freed
));
4867 if (sbi
->s_log_groups_per_flex
) {
4868 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4869 atomic_add(EXT4_B2C(sbi
, blocks_freed
),
4870 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4873 ext4_mb_unload_buddy(&e4b
);
4875 /* We dirtied the bitmap block */
4876 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4877 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4879 /* And the group descriptor block */
4880 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4881 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4887 ext4_std_error(sb
, err
);
4892 * ext4_trim_extent -- function to TRIM one single free extent in the group
4893 * @sb: super block for the file system
4894 * @start: starting block of the free extent in the alloc. group
4895 * @count: number of blocks to TRIM
4896 * @group: alloc. group we are working with
4897 * @e4b: ext4 buddy for the group
4899 * Trim "count" blocks starting at "start" in the "group". To assure that no
4900 * one will allocate those blocks, mark it as used in buddy bitmap. This must
4901 * be called with under the group lock.
4903 static void ext4_trim_extent(struct super_block
*sb
, int start
, int count
,
4904 ext4_group_t group
, struct ext4_buddy
*e4b
)
4906 struct ext4_free_extent ex
;
4908 trace_ext4_trim_extent(sb
, group
, start
, count
);
4910 assert_spin_locked(ext4_group_lock_ptr(sb
, group
));
4912 ex
.fe_start
= start
;
4913 ex
.fe_group
= group
;
4917 * Mark blocks used, so no one can reuse them while
4920 mb_mark_used(e4b
, &ex
);
4921 ext4_unlock_group(sb
, group
);
4922 ext4_issue_discard(sb
, group
, start
, count
);
4923 ext4_lock_group(sb
, group
);
4924 mb_free_blocks(NULL
, e4b
, start
, ex
.fe_len
);
4928 * ext4_trim_all_free -- function to trim all free space in alloc. group
4929 * @sb: super block for file system
4930 * @group: group to be trimmed
4931 * @start: first group block to examine
4932 * @max: last group block to examine
4933 * @minblocks: minimum extent block count
4935 * ext4_trim_all_free walks through group's buddy bitmap searching for free
4936 * extents. When the free block is found, ext4_trim_extent is called to TRIM
4940 * ext4_trim_all_free walks through group's block bitmap searching for free
4941 * extents. When the free extent is found, mark it as used in group buddy
4942 * bitmap. Then issue a TRIM command on this extent and free the extent in
4943 * the group buddy bitmap. This is done until whole group is scanned.
4945 static ext4_grpblk_t
4946 ext4_trim_all_free(struct super_block
*sb
, ext4_group_t group
,
4947 ext4_grpblk_t start
, ext4_grpblk_t max
,
4948 ext4_grpblk_t minblocks
)
4951 ext4_grpblk_t next
, count
= 0, free_count
= 0;
4952 struct ext4_buddy e4b
;
4955 trace_ext4_trim_all_free(sb
, group
, start
, max
);
4957 ret
= ext4_mb_load_buddy(sb
, group
, &e4b
);
4959 ext4_error(sb
, "Error in loading buddy "
4960 "information for %u", group
);
4963 bitmap
= e4b
.bd_bitmap
;
4965 ext4_lock_group(sb
, group
);
4966 if (EXT4_MB_GRP_WAS_TRIMMED(e4b
.bd_info
) &&
4967 minblocks
>= atomic_read(&EXT4_SB(sb
)->s_last_trim_minblks
))
4970 start
= (e4b
.bd_info
->bb_first_free
> start
) ?
4971 e4b
.bd_info
->bb_first_free
: start
;
4973 while (start
< max
) {
4974 start
= mb_find_next_zero_bit(bitmap
, max
, start
);
4977 next
= mb_find_next_bit(bitmap
, max
, start
);
4979 if ((next
- start
) >= minblocks
) {
4980 ext4_trim_extent(sb
, start
,
4981 next
- start
, group
, &e4b
);
4982 count
+= next
- start
;
4984 free_count
+= next
- start
;
4987 if (fatal_signal_pending(current
)) {
4988 count
= -ERESTARTSYS
;
4992 if (need_resched()) {
4993 ext4_unlock_group(sb
, group
);
4995 ext4_lock_group(sb
, group
);
4998 if ((e4b
.bd_info
->bb_free
- free_count
) < minblocks
)
5003 EXT4_MB_GRP_SET_TRIMMED(e4b
.bd_info
);
5005 ext4_unlock_group(sb
, group
);
5006 ext4_mb_unload_buddy(&e4b
);
5008 ext4_debug("trimmed %d blocks in the group %d\n",
5015 * ext4_trim_fs() -- trim ioctl handle function
5016 * @sb: superblock for filesystem
5017 * @range: fstrim_range structure
5019 * start: First Byte to trim
5020 * len: number of Bytes to trim from start
5021 * minlen: minimum extent length in Bytes
5022 * ext4_trim_fs goes through all allocation groups containing Bytes from
5023 * start to start+len. For each such a group ext4_trim_all_free function
5024 * is invoked to trim all free space.
5026 int ext4_trim_fs(struct super_block
*sb
, struct fstrim_range
*range
)
5028 struct ext4_group_info
*grp
;
5029 ext4_group_t first_group
, last_group
;
5030 ext4_group_t group
, ngroups
= ext4_get_groups_count(sb
);
5031 ext4_grpblk_t cnt
= 0, first_cluster
, last_cluster
;
5032 uint64_t start
, len
, minlen
, trimmed
= 0;
5033 ext4_fsblk_t first_data_blk
=
5034 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
5037 start
= range
->start
>> sb
->s_blocksize_bits
;
5038 len
= range
->len
>> sb
->s_blocksize_bits
;
5039 minlen
= range
->minlen
>> sb
->s_blocksize_bits
;
5041 if (unlikely(minlen
> EXT4_CLUSTERS_PER_GROUP(sb
)))
5043 if (start
+ len
<= first_data_blk
)
5045 if (start
< first_data_blk
) {
5046 len
-= first_data_blk
- start
;
5047 start
= first_data_blk
;
5050 /* Determine first and last group to examine based on start and len */
5051 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) start
,
5052 &first_group
, &first_cluster
);
5053 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) (start
+ len
),
5054 &last_group
, &last_cluster
);
5055 last_group
= (last_group
> ngroups
- 1) ? ngroups
- 1 : last_group
;
5056 last_cluster
= EXT4_CLUSTERS_PER_GROUP(sb
);
5058 if (first_group
> last_group
)
5061 for (group
= first_group
; group
<= last_group
; group
++) {
5062 grp
= ext4_get_group_info(sb
, group
);
5063 /* We only do this if the grp has never been initialized */
5064 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
5065 ret
= ext4_mb_init_group(sb
, group
);
5071 * For all the groups except the last one, last block will
5072 * always be EXT4_BLOCKS_PER_GROUP(sb), so we only need to
5073 * change it for the last group in which case start +
5074 * len < EXT4_BLOCKS_PER_GROUP(sb).
5076 if (first_cluster
+ len
< EXT4_CLUSTERS_PER_GROUP(sb
))
5077 last_cluster
= first_cluster
+ len
;
5078 len
-= last_cluster
- first_cluster
;
5080 if (grp
->bb_free
>= minlen
) {
5081 cnt
= ext4_trim_all_free(sb
, group
, first_cluster
,
5082 last_cluster
, minlen
);
5091 range
->len
= trimmed
* sb
->s_blocksize
;
5094 atomic_set(&EXT4_SB(sb
)->s_last_trim_minblks
, minlen
);