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 License
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
24 #include "ext4_jbd2.h"
26 #include <linux/log2.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <linux/backing-dev.h>
30 #include <trace/events/ext4.h>
32 #ifdef CONFIG_EXT4_DEBUG
33 ushort ext4_mballoc_debug __read_mostly
;
35 module_param_named(mballoc_debug
, ext4_mballoc_debug
, ushort
, 0644);
36 MODULE_PARM_DESC(mballoc_debug
, "Debugging level for ext4's mballoc");
41 * - test ext4_ext_search_left() and ext4_ext_search_right()
42 * - search for metadata in few groups
45 * - normalization should take into account whether file is still open
46 * - discard preallocations if no free space left (policy?)
47 * - don't normalize tails
49 * - reservation for superuser
52 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
53 * - track min/max extents in each group for better group selection
54 * - mb_mark_used() may allocate chunk right after splitting buddy
55 * - tree of groups sorted by number of free blocks
60 * The allocation request involve request for multiple number of blocks
61 * near to the goal(block) value specified.
63 * During initialization phase of the allocator we decide to use the
64 * group preallocation or inode preallocation depending on the size of
65 * the file. The size of the file could be the resulting file size we
66 * would have after allocation, or the current file size, which ever
67 * is larger. If the size is less than sbi->s_mb_stream_request we
68 * select to use the group preallocation. The default value of
69 * s_mb_stream_request is 16 blocks. This can also be tuned via
70 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
71 * terms of number of blocks.
73 * The main motivation for having small file use group preallocation is to
74 * ensure that we have small files closer together on the disk.
76 * First stage the allocator looks at the inode prealloc list,
77 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
78 * spaces for this particular inode. The inode prealloc space is
81 * pa_lstart -> the logical start block for this prealloc space
82 * pa_pstart -> the physical start block for this prealloc space
83 * pa_len -> length for this prealloc space (in clusters)
84 * pa_free -> free space available in this prealloc space (in clusters)
86 * The inode preallocation space is used looking at the _logical_ start
87 * block. If only the logical file block falls within the range of prealloc
88 * space we will consume the particular prealloc space. This makes sure that
89 * we have contiguous physical blocks representing the file blocks
91 * The important thing to be noted in case of inode prealloc space is that
92 * we don't modify the values associated to inode prealloc space except
95 * If we are not able to find blocks in the inode prealloc space and if we
96 * have the group allocation flag set then we look at the locality group
97 * prealloc space. These are per CPU prealloc list represented as
99 * ext4_sb_info.s_locality_groups[smp_processor_id()]
101 * The reason for having a per cpu locality group is to reduce the contention
102 * between CPUs. It is possible to get scheduled at this point.
104 * The locality group prealloc space is used looking at whether we have
105 * enough free space (pa_free) within the prealloc space.
107 * If we can't allocate blocks via inode prealloc or/and locality group
108 * prealloc then we look at the buddy cache. The buddy cache is represented
109 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
110 * mapped to the buddy and bitmap information regarding different
111 * groups. The buddy information is attached to buddy cache inode so that
112 * we can access them through the page cache. The information regarding
113 * each group is loaded via ext4_mb_load_buddy. The information involve
114 * block bitmap and buddy information. The information are stored in the
118 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
121 * one block each for bitmap and buddy information. So for each group we
122 * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
123 * blocksize) blocks. So it can have information regarding groups_per_page
124 * which is blocks_per_page/2
126 * The buddy cache inode is not stored on disk. The inode is thrown
127 * away when the filesystem is unmounted.
129 * We look for count number of blocks in the buddy cache. If we were able
130 * to locate that many free blocks we return with additional information
131 * regarding rest of the contiguous physical block available
133 * Before allocating blocks via buddy cache we normalize the request
134 * blocks. This ensure we ask for more blocks that we needed. The extra
135 * blocks that we get after allocation is added to the respective prealloc
136 * list. In case of inode preallocation we follow a list of heuristics
137 * based on file size. This can be found in ext4_mb_normalize_request. If
138 * we are doing a group prealloc we try to normalize the request to
139 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
140 * dependent on the cluster size; for non-bigalloc file systems, it is
141 * 512 blocks. This can be tuned via
142 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
143 * terms of number of blocks. If we have mounted the file system with -O
144 * stripe=<value> option the group prealloc request is normalized to the
145 * the smallest multiple of the stripe value (sbi->s_stripe) which is
146 * greater than the default mb_group_prealloc.
148 * The regular allocator (using the buddy cache) supports a few tunables.
150 * /sys/fs/ext4/<partition>/mb_min_to_scan
151 * /sys/fs/ext4/<partition>/mb_max_to_scan
152 * /sys/fs/ext4/<partition>/mb_order2_req
154 * The regular allocator uses buddy scan only if the request len is power of
155 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
156 * value of s_mb_order2_reqs can be tuned via
157 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
158 * stripe size (sbi->s_stripe), we try to search for contiguous block in
159 * stripe size. This should result in better allocation on RAID setups. If
160 * not, we search in the specific group using bitmap for best extents. The
161 * tunable min_to_scan and max_to_scan control the behaviour here.
162 * min_to_scan indicate how long the mballoc __must__ look for a best
163 * extent and max_to_scan indicates how long the mballoc __can__ look for a
164 * best extent in the found extents. Searching for the blocks starts with
165 * the group specified as the goal value in allocation context via
166 * ac_g_ex. Each group is first checked based on the criteria whether it
167 * can be used for allocation. ext4_mb_good_group explains how the groups are
170 * Both the prealloc space are getting populated as above. So for the first
171 * request we will hit the buddy cache which will result in this prealloc
172 * space getting filled. The prealloc space is then later used for the
173 * subsequent request.
177 * mballoc operates on the following data:
179 * - in-core buddy (actually includes buddy and bitmap)
180 * - preallocation descriptors (PAs)
182 * there are two types of preallocations:
184 * assiged to specific inode and can be used for this inode only.
185 * it describes part of inode's space preallocated to specific
186 * physical blocks. any block from that preallocated can be used
187 * independent. the descriptor just tracks number of blocks left
188 * unused. so, before taking some block from descriptor, one must
189 * make sure corresponded logical block isn't allocated yet. this
190 * also means that freeing any block within descriptor's range
191 * must discard all preallocated blocks.
193 * assigned to specific locality group which does not translate to
194 * permanent set of inodes: inode can join and leave group. space
195 * from this type of preallocation can be used for any inode. thus
196 * it's consumed from the beginning to the end.
198 * relation between them can be expressed as:
199 * in-core buddy = on-disk bitmap + preallocation descriptors
201 * this mean blocks mballoc considers used are:
202 * - allocated blocks (persistent)
203 * - preallocated blocks (non-persistent)
205 * consistency in mballoc world means that at any time a block is either
206 * free or used in ALL structures. notice: "any time" should not be read
207 * literally -- time is discrete and delimited by locks.
209 * to keep it simple, we don't use block numbers, instead we count number of
210 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
212 * all operations can be expressed as:
213 * - init buddy: buddy = on-disk + PAs
214 * - new PA: buddy += N; PA = N
215 * - use inode PA: on-disk += N; PA -= N
216 * - discard inode PA buddy -= on-disk - PA; PA = 0
217 * - use locality group PA on-disk += N; PA -= N
218 * - discard locality group PA buddy -= PA; PA = 0
219 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
220 * is used in real operation because we can't know actual used
221 * bits from PA, only from on-disk bitmap
223 * if we follow this strict logic, then all operations above should be atomic.
224 * given some of them can block, we'd have to use something like semaphores
225 * killing performance on high-end SMP hardware. let's try to relax it using
226 * the following knowledge:
227 * 1) if buddy is referenced, it's already initialized
228 * 2) while block is used in buddy and the buddy is referenced,
229 * nobody can re-allocate that block
230 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
231 * bit set and PA claims same block, it's OK. IOW, one can set bit in
232 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
235 * so, now we're building a concurrency table:
238 * blocks for PA are allocated in the buddy, buddy must be referenced
239 * until PA is linked to allocation group to avoid concurrent buddy init
241 * we need to make sure that either on-disk bitmap or PA has uptodate data
242 * given (3) we care that PA-=N operation doesn't interfere with init
244 * the simplest way would be to have buddy initialized by the discard
245 * - use locality group PA
246 * again PA-=N must be serialized with init
247 * - discard locality group PA
248 * the simplest way would be to have buddy initialized by the discard
251 * i_data_sem serializes them
253 * discard process must wait until PA isn't used by another process
254 * - use locality group PA
255 * some mutex should serialize them
256 * - discard locality group PA
257 * discard process must wait until PA isn't used by another process
260 * i_data_sem or another mutex should serializes them
262 * discard process must wait until PA isn't used by another process
263 * - use locality group PA
264 * nothing wrong here -- they're different PAs covering different blocks
265 * - discard locality group PA
266 * discard process must wait until PA isn't used by another process
268 * now we're ready to make few consequences:
269 * - PA is referenced and while it is no discard is possible
270 * - PA is referenced until block isn't marked in on-disk bitmap
271 * - PA changes only after on-disk bitmap
272 * - discard must not compete with init. either init is done before
273 * any discard or they're serialized somehow
274 * - buddy init as sum of on-disk bitmap and PAs is done atomically
276 * a special case when we've used PA to emptiness. no need to modify buddy
277 * in this case, but we should care about concurrent init
282 * Logic in few words:
287 * mark bits in on-disk bitmap
290 * - use preallocation:
291 * find proper PA (per-inode or group)
293 * mark bits in on-disk bitmap
299 * mark bits in on-disk bitmap
302 * - discard preallocations in group:
304 * move them onto local list
305 * load on-disk bitmap
307 * remove PA from object (inode or locality group)
308 * mark free blocks in-core
310 * - discard inode's preallocations:
317 * - bitlock on a group (group)
318 * - object (inode/locality) (object)
329 * - release consumed pa:
334 * - generate in-core bitmap:
338 * - discard all for given object (inode, locality group):
343 * - discard all for given group:
350 static struct kmem_cache
*ext4_pspace_cachep
;
351 static struct kmem_cache
*ext4_ac_cachep
;
352 static struct kmem_cache
*ext4_free_data_cachep
;
354 /* We create slab caches for groupinfo data structures based on the
355 * superblock block size. There will be one per mounted filesystem for
356 * each unique s_blocksize_bits */
357 #define NR_GRPINFO_CACHES 8
358 static struct kmem_cache
*ext4_groupinfo_caches
[NR_GRPINFO_CACHES
];
360 static const char * const ext4_groupinfo_slab_names
[NR_GRPINFO_CACHES
] = {
361 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
362 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
363 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
366 static void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
368 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
371 static inline void *mb_correct_addr_and_bit(int *bit
, void *addr
)
373 #if BITS_PER_LONG == 64
374 *bit
+= ((unsigned long) addr
& 7UL) << 3;
375 addr
= (void *) ((unsigned long) addr
& ~7UL);
376 #elif BITS_PER_LONG == 32
377 *bit
+= ((unsigned long) addr
& 3UL) << 3;
378 addr
= (void *) ((unsigned long) addr
& ~3UL);
380 #error "how many bits you are?!"
385 static inline int mb_test_bit(int bit
, void *addr
)
388 * ext4_test_bit on architecture like powerpc
389 * needs unsigned long aligned address
391 addr
= mb_correct_addr_and_bit(&bit
, addr
);
392 return ext4_test_bit(bit
, addr
);
395 static inline void mb_set_bit(int bit
, void *addr
)
397 addr
= mb_correct_addr_and_bit(&bit
, addr
);
398 ext4_set_bit(bit
, addr
);
401 static inline void mb_clear_bit(int bit
, void *addr
)
403 addr
= mb_correct_addr_and_bit(&bit
, addr
);
404 ext4_clear_bit(bit
, addr
);
407 static inline int mb_test_and_clear_bit(int bit
, void *addr
)
409 addr
= mb_correct_addr_and_bit(&bit
, addr
);
410 return ext4_test_and_clear_bit(bit
, addr
);
413 static inline int mb_find_next_zero_bit(void *addr
, int max
, int start
)
415 int fix
= 0, ret
, tmpmax
;
416 addr
= mb_correct_addr_and_bit(&fix
, addr
);
420 ret
= ext4_find_next_zero_bit(addr
, tmpmax
, start
) - fix
;
426 static inline int mb_find_next_bit(void *addr
, int max
, int start
)
428 int fix
= 0, ret
, tmpmax
;
429 addr
= mb_correct_addr_and_bit(&fix
, addr
);
433 ret
= ext4_find_next_bit(addr
, tmpmax
, start
) - fix
;
439 static void *mb_find_buddy(struct ext4_buddy
*e4b
, int order
, int *max
)
443 BUG_ON(e4b
->bd_bitmap
== e4b
->bd_buddy
);
446 if (order
> e4b
->bd_blkbits
+ 1) {
451 /* at order 0 we see each particular block */
453 *max
= 1 << (e4b
->bd_blkbits
+ 3);
454 return e4b
->bd_bitmap
;
457 bb
= e4b
->bd_buddy
+ EXT4_SB(e4b
->bd_sb
)->s_mb_offsets
[order
];
458 *max
= EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[order
];
464 static void mb_free_blocks_double(struct inode
*inode
, struct ext4_buddy
*e4b
,
465 int first
, int count
)
468 struct super_block
*sb
= e4b
->bd_sb
;
470 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
472 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
473 for (i
= 0; i
< count
; i
++) {
474 if (!mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
)) {
475 ext4_fsblk_t blocknr
;
477 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
478 blocknr
+= EXT4_C2B(EXT4_SB(sb
), first
+ i
);
479 ext4_grp_locked_error(sb
, e4b
->bd_group
,
480 inode
? inode
->i_ino
: 0,
482 "freeing block already freed "
486 mb_clear_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
490 static void mb_mark_used_double(struct ext4_buddy
*e4b
, int first
, int count
)
494 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
496 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
497 for (i
= 0; i
< count
; i
++) {
498 BUG_ON(mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
));
499 mb_set_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
503 static void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
505 if (memcmp(e4b
->bd_info
->bb_bitmap
, bitmap
, e4b
->bd_sb
->s_blocksize
)) {
506 unsigned char *b1
, *b2
;
508 b1
= (unsigned char *) e4b
->bd_info
->bb_bitmap
;
509 b2
= (unsigned char *) bitmap
;
510 for (i
= 0; i
< e4b
->bd_sb
->s_blocksize
; i
++) {
511 if (b1
[i
] != b2
[i
]) {
512 ext4_msg(e4b
->bd_sb
, KERN_ERR
,
513 "corruption in group %u "
514 "at byte %u(%u): %x in copy != %x "
516 e4b
->bd_group
, i
, i
* 8, b1
[i
], b2
[i
]);
524 static inline void mb_free_blocks_double(struct inode
*inode
,
525 struct ext4_buddy
*e4b
, int first
, int count
)
529 static inline void mb_mark_used_double(struct ext4_buddy
*e4b
,
530 int first
, int count
)
534 static inline void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
540 #ifdef AGGRESSIVE_CHECK
542 #define MB_CHECK_ASSERT(assert) \
546 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
547 function, file, line, # assert); \
552 static int __mb_check_buddy(struct ext4_buddy
*e4b
, char *file
,
553 const char *function
, int line
)
555 struct super_block
*sb
= e4b
->bd_sb
;
556 int order
= e4b
->bd_blkbits
+ 1;
563 struct ext4_group_info
*grp
;
566 struct list_head
*cur
;
571 static int mb_check_counter
;
572 if (mb_check_counter
++ % 100 != 0)
577 buddy
= mb_find_buddy(e4b
, order
, &max
);
578 MB_CHECK_ASSERT(buddy
);
579 buddy2
= mb_find_buddy(e4b
, order
- 1, &max2
);
580 MB_CHECK_ASSERT(buddy2
);
581 MB_CHECK_ASSERT(buddy
!= buddy2
);
582 MB_CHECK_ASSERT(max
* 2 == max2
);
585 for (i
= 0; i
< max
; i
++) {
587 if (mb_test_bit(i
, buddy
)) {
588 /* only single bit in buddy2 may be 1 */
589 if (!mb_test_bit(i
<< 1, buddy2
)) {
591 mb_test_bit((i
<<1)+1, buddy2
));
592 } else if (!mb_test_bit((i
<< 1) + 1, buddy2
)) {
594 mb_test_bit(i
<< 1, buddy2
));
599 /* both bits in buddy2 must be 1 */
600 MB_CHECK_ASSERT(mb_test_bit(i
<< 1, buddy2
));
601 MB_CHECK_ASSERT(mb_test_bit((i
<< 1) + 1, buddy2
));
603 for (j
= 0; j
< (1 << order
); j
++) {
604 k
= (i
* (1 << order
)) + j
;
606 !mb_test_bit(k
, e4b
->bd_bitmap
));
610 MB_CHECK_ASSERT(e4b
->bd_info
->bb_counters
[order
] == count
);
615 buddy
= mb_find_buddy(e4b
, 0, &max
);
616 for (i
= 0; i
< max
; i
++) {
617 if (!mb_test_bit(i
, buddy
)) {
618 MB_CHECK_ASSERT(i
>= e4b
->bd_info
->bb_first_free
);
626 /* check used bits only */
627 for (j
= 0; j
< e4b
->bd_blkbits
+ 1; j
++) {
628 buddy2
= mb_find_buddy(e4b
, j
, &max2
);
630 MB_CHECK_ASSERT(k
< max2
);
631 MB_CHECK_ASSERT(mb_test_bit(k
, buddy2
));
634 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b
->bd_info
));
635 MB_CHECK_ASSERT(e4b
->bd_info
->bb_fragments
== fragments
);
637 grp
= ext4_get_group_info(sb
, e4b
->bd_group
);
638 list_for_each(cur
, &grp
->bb_prealloc_list
) {
639 ext4_group_t groupnr
;
640 struct ext4_prealloc_space
*pa
;
641 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
642 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &groupnr
, &k
);
643 MB_CHECK_ASSERT(groupnr
== e4b
->bd_group
);
644 for (i
= 0; i
< pa
->pa_len
; i
++)
645 MB_CHECK_ASSERT(mb_test_bit(k
+ i
, buddy
));
649 #undef MB_CHECK_ASSERT
650 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
651 __FILE__, __func__, __LINE__)
653 #define mb_check_buddy(e4b)
657 * Divide blocks started from @first with length @len into
658 * smaller chunks with power of 2 blocks.
659 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
660 * then increase bb_counters[] for corresponded chunk size.
662 static void ext4_mb_mark_free_simple(struct super_block
*sb
,
663 void *buddy
, ext4_grpblk_t first
, ext4_grpblk_t len
,
664 struct ext4_group_info
*grp
)
666 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
672 BUG_ON(len
> EXT4_CLUSTERS_PER_GROUP(sb
));
674 border
= 2 << sb
->s_blocksize_bits
;
677 /* find how many blocks can be covered since this position */
678 max
= ffs(first
| border
) - 1;
680 /* find how many blocks of power 2 we need to mark */
687 /* mark multiblock chunks only */
688 grp
->bb_counters
[min
]++;
690 mb_clear_bit(first
>> min
,
691 buddy
+ sbi
->s_mb_offsets
[min
]);
699 * Cache the order of the largest free extent we have available in this block
703 mb_set_largest_free_order(struct super_block
*sb
, struct ext4_group_info
*grp
)
708 grp
->bb_largest_free_order
= -1; /* uninit */
710 bits
= sb
->s_blocksize_bits
+ 1;
711 for (i
= bits
; i
>= 0; i
--) {
712 if (grp
->bb_counters
[i
] > 0) {
713 grp
->bb_largest_free_order
= i
;
719 static noinline_for_stack
720 void ext4_mb_generate_buddy(struct super_block
*sb
,
721 void *buddy
, void *bitmap
, ext4_group_t group
)
723 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
724 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
725 ext4_grpblk_t max
= EXT4_CLUSTERS_PER_GROUP(sb
);
730 unsigned fragments
= 0;
731 unsigned long long period
= get_cycles();
733 /* initialize buddy from bitmap which is aggregation
734 * of on-disk bitmap and preallocations */
735 i
= mb_find_next_zero_bit(bitmap
, max
, 0);
736 grp
->bb_first_free
= i
;
740 i
= mb_find_next_bit(bitmap
, max
, i
);
744 ext4_mb_mark_free_simple(sb
, buddy
, first
, len
, grp
);
746 grp
->bb_counters
[0]++;
748 i
= mb_find_next_zero_bit(bitmap
, max
, i
);
750 grp
->bb_fragments
= fragments
;
752 if (free
!= grp
->bb_free
) {
753 ext4_grp_locked_error(sb
, group
, 0, 0,
754 "block bitmap and bg descriptor "
755 "inconsistent: %u vs %u free clusters",
758 * If we intend to continue, we consider group descriptor
759 * corrupt and update bb_free using bitmap value
762 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp
))
763 percpu_counter_sub(&sbi
->s_freeclusters_counter
,
765 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT
, &grp
->bb_state
);
767 mb_set_largest_free_order(sb
, grp
);
769 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
, &(grp
->bb_state
));
771 period
= get_cycles() - period
;
772 spin_lock(&EXT4_SB(sb
)->s_bal_lock
);
773 EXT4_SB(sb
)->s_mb_buddies_generated
++;
774 EXT4_SB(sb
)->s_mb_generation_time
+= period
;
775 spin_unlock(&EXT4_SB(sb
)->s_bal_lock
);
778 static void mb_regenerate_buddy(struct ext4_buddy
*e4b
)
784 while ((buddy
= mb_find_buddy(e4b
, order
++, &count
))) {
785 ext4_set_bits(buddy
, 0, count
);
787 e4b
->bd_info
->bb_fragments
= 0;
788 memset(e4b
->bd_info
->bb_counters
, 0,
789 sizeof(*e4b
->bd_info
->bb_counters
) *
790 (e4b
->bd_sb
->s_blocksize_bits
+ 2));
792 ext4_mb_generate_buddy(e4b
->bd_sb
, e4b
->bd_buddy
,
793 e4b
->bd_bitmap
, e4b
->bd_group
);
796 /* The buddy information is attached the buddy cache inode
797 * for convenience. The information regarding each group
798 * is loaded via ext4_mb_load_buddy. The information involve
799 * block bitmap and buddy information. The information are
800 * stored in the inode as
803 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
806 * one block each for bitmap and buddy information.
807 * So for each group we take up 2 blocks. A page can
808 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
809 * So it can have information regarding groups_per_page which
810 * is blocks_per_page/2
812 * Locking note: This routine takes the block group lock of all groups
813 * for this page; do not hold this lock when calling this routine!
816 static int ext4_mb_init_cache(struct page
*page
, char *incore
, gfp_t gfp
)
818 ext4_group_t ngroups
;
824 ext4_group_t first_group
, group
;
826 struct super_block
*sb
;
827 struct buffer_head
*bhs
;
828 struct buffer_head
**bh
= NULL
;
832 struct ext4_group_info
*grinfo
;
834 mb_debug(1, "init page %lu\n", page
->index
);
836 inode
= page
->mapping
->host
;
838 ngroups
= ext4_get_groups_count(sb
);
839 blocksize
= i_blocksize(inode
);
840 blocks_per_page
= PAGE_SIZE
/ blocksize
;
842 groups_per_page
= blocks_per_page
>> 1;
843 if (groups_per_page
== 0)
846 /* allocate buffer_heads to read bitmaps */
847 if (groups_per_page
> 1) {
848 i
= sizeof(struct buffer_head
*) * groups_per_page
;
849 bh
= kzalloc(i
, gfp
);
857 first_group
= page
->index
* blocks_per_page
/ 2;
859 /* read all groups the page covers into the cache */
860 for (i
= 0, group
= first_group
; i
< groups_per_page
; i
++, group
++) {
861 if (group
>= ngroups
)
864 grinfo
= ext4_get_group_info(sb
, group
);
866 * If page is uptodate then we came here after online resize
867 * which added some new uninitialized group info structs, so
868 * we must skip all initialized uptodate buddies on the page,
869 * which may be currently in use by an allocating task.
871 if (PageUptodate(page
) && !EXT4_MB_GRP_NEED_INIT(grinfo
)) {
875 bh
[i
] = ext4_read_block_bitmap_nowait(sb
, group
);
877 err
= PTR_ERR(bh
[i
]);
881 mb_debug(1, "read bitmap for group %u\n", group
);
884 /* wait for I/O completion */
885 for (i
= 0, group
= first_group
; i
< groups_per_page
; i
++, group
++) {
890 err2
= ext4_wait_block_bitmap(sb
, group
, bh
[i
]);
895 first_block
= page
->index
* blocks_per_page
;
896 for (i
= 0; i
< blocks_per_page
; i
++) {
897 group
= (first_block
+ i
) >> 1;
898 if (group
>= ngroups
)
901 if (!bh
[group
- first_group
])
902 /* skip initialized uptodate buddy */
905 if (!buffer_verified(bh
[group
- first_group
]))
906 /* Skip faulty bitmaps */
911 * data carry information regarding this
912 * particular group in the format specified
916 data
= page_address(page
) + (i
* blocksize
);
917 bitmap
= bh
[group
- first_group
]->b_data
;
920 * We place the buddy block and bitmap block
923 if ((first_block
+ i
) & 1) {
924 /* this is block of buddy */
925 BUG_ON(incore
== NULL
);
926 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
927 group
, page
->index
, i
* blocksize
);
928 trace_ext4_mb_buddy_bitmap_load(sb
, group
);
929 grinfo
= ext4_get_group_info(sb
, group
);
930 grinfo
->bb_fragments
= 0;
931 memset(grinfo
->bb_counters
, 0,
932 sizeof(*grinfo
->bb_counters
) *
933 (sb
->s_blocksize_bits
+2));
935 * incore got set to the group block bitmap below
937 ext4_lock_group(sb
, group
);
939 memset(data
, 0xff, blocksize
);
940 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
941 ext4_unlock_group(sb
, group
);
944 /* this is block of bitmap */
945 BUG_ON(incore
!= NULL
);
946 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
947 group
, page
->index
, i
* blocksize
);
948 trace_ext4_mb_bitmap_load(sb
, group
);
950 /* see comments in ext4_mb_put_pa() */
951 ext4_lock_group(sb
, group
);
952 memcpy(data
, bitmap
, blocksize
);
954 /* mark all preallocated blks used in in-core bitmap */
955 ext4_mb_generate_from_pa(sb
, data
, group
);
956 ext4_mb_generate_from_freelist(sb
, data
, group
);
957 ext4_unlock_group(sb
, group
);
959 /* set incore so that the buddy information can be
960 * generated using this
965 SetPageUptodate(page
);
969 for (i
= 0; i
< groups_per_page
; i
++)
978 * Lock the buddy and bitmap pages. This make sure other parallel init_group
979 * on the same buddy page doesn't happen whild holding the buddy page lock.
980 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
981 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
983 static int ext4_mb_get_buddy_page_lock(struct super_block
*sb
,
984 ext4_group_t group
, struct ext4_buddy
*e4b
, gfp_t gfp
)
986 struct inode
*inode
= EXT4_SB(sb
)->s_buddy_cache
;
987 int block
, pnum
, poff
;
991 e4b
->bd_buddy_page
= NULL
;
992 e4b
->bd_bitmap_page
= NULL
;
994 blocks_per_page
= PAGE_SIZE
/ sb
->s_blocksize
;
996 * the buddy cache inode stores the block bitmap
997 * and buddy information in consecutive blocks.
998 * So for each group we need two blocks.
1001 pnum
= block
/ blocks_per_page
;
1002 poff
= block
% blocks_per_page
;
1003 page
= find_or_create_page(inode
->i_mapping
, pnum
, gfp
);
1006 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1007 e4b
->bd_bitmap_page
= page
;
1008 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1010 if (blocks_per_page
>= 2) {
1011 /* buddy and bitmap are on the same page */
1016 pnum
= block
/ blocks_per_page
;
1017 page
= find_or_create_page(inode
->i_mapping
, pnum
, gfp
);
1020 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1021 e4b
->bd_buddy_page
= page
;
1025 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy
*e4b
)
1027 if (e4b
->bd_bitmap_page
) {
1028 unlock_page(e4b
->bd_bitmap_page
);
1029 put_page(e4b
->bd_bitmap_page
);
1031 if (e4b
->bd_buddy_page
) {
1032 unlock_page(e4b
->bd_buddy_page
);
1033 put_page(e4b
->bd_buddy_page
);
1038 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1039 * block group lock of all groups for this page; do not hold the BG lock when
1040 * calling this routine!
1042 static noinline_for_stack
1043 int ext4_mb_init_group(struct super_block
*sb
, ext4_group_t group
, gfp_t gfp
)
1046 struct ext4_group_info
*this_grp
;
1047 struct ext4_buddy e4b
;
1052 mb_debug(1, "init group %u\n", group
);
1053 this_grp
= ext4_get_group_info(sb
, group
);
1055 * This ensures that we don't reinit the buddy cache
1056 * page which map to the group from which we are already
1057 * allocating. If we are looking at the buddy cache we would
1058 * have taken a reference using ext4_mb_load_buddy and that
1059 * would have pinned buddy page to page cache.
1060 * The call to ext4_mb_get_buddy_page_lock will mark the
1063 ret
= ext4_mb_get_buddy_page_lock(sb
, group
, &e4b
, gfp
);
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
, gfp
);
1076 if (!PageUptodate(page
)) {
1081 if (e4b
.bd_buddy_page
== NULL
) {
1083 * If both the bitmap and buddy are in
1084 * the same page we don't need to force
1090 /* init buddy cache */
1091 page
= e4b
.bd_buddy_page
;
1092 ret
= ext4_mb_init_cache(page
, e4b
.bd_bitmap
, gfp
);
1095 if (!PageUptodate(page
)) {
1100 ext4_mb_put_buddy_page_lock(&e4b
);
1105 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1106 * block group lock of all groups for this page; do not hold the BG lock when
1107 * calling this routine!
1109 static noinline_for_stack
int
1110 ext4_mb_load_buddy_gfp(struct super_block
*sb
, ext4_group_t group
,
1111 struct ext4_buddy
*e4b
, gfp_t gfp
)
1113 int blocks_per_page
;
1119 struct ext4_group_info
*grp
;
1120 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1121 struct inode
*inode
= sbi
->s_buddy_cache
;
1124 mb_debug(1, "load group %u\n", group
);
1126 blocks_per_page
= PAGE_SIZE
/ sb
->s_blocksize
;
1127 grp
= ext4_get_group_info(sb
, group
);
1129 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
1132 e4b
->bd_group
= group
;
1133 e4b
->bd_buddy_page
= NULL
;
1134 e4b
->bd_bitmap_page
= NULL
;
1136 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1138 * we need full data about the group
1139 * to make a good selection
1141 ret
= ext4_mb_init_group(sb
, group
, gfp
);
1147 * the buddy cache inode stores the block bitmap
1148 * and buddy information in consecutive blocks.
1149 * So for each group we need two blocks.
1152 pnum
= block
/ blocks_per_page
;
1153 poff
= block
% blocks_per_page
;
1155 /* we could use find_or_create_page(), but it locks page
1156 * what we'd like to avoid in fast path ... */
1157 page
= find_get_page_flags(inode
->i_mapping
, pnum
, FGP_ACCESSED
);
1158 if (page
== NULL
|| !PageUptodate(page
)) {
1161 * drop the page reference and try
1162 * to get the page with lock. If we
1163 * are not uptodate that implies
1164 * somebody just created the page but
1165 * is yet to initialize the same. So
1166 * wait for it to initialize.
1169 page
= find_or_create_page(inode
->i_mapping
, pnum
, gfp
);
1171 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1172 if (!PageUptodate(page
)) {
1173 ret
= ext4_mb_init_cache(page
, NULL
, gfp
);
1178 mb_cmp_bitmaps(e4b
, page_address(page
) +
1179 (poff
* sb
->s_blocksize
));
1188 if (!PageUptodate(page
)) {
1193 /* Pages marked accessed already */
1194 e4b
->bd_bitmap_page
= page
;
1195 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1198 pnum
= block
/ blocks_per_page
;
1199 poff
= block
% blocks_per_page
;
1201 page
= find_get_page_flags(inode
->i_mapping
, pnum
, FGP_ACCESSED
);
1202 if (page
== NULL
|| !PageUptodate(page
)) {
1205 page
= find_or_create_page(inode
->i_mapping
, pnum
, gfp
);
1207 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1208 if (!PageUptodate(page
)) {
1209 ret
= ext4_mb_init_cache(page
, e4b
->bd_bitmap
,
1223 if (!PageUptodate(page
)) {
1228 /* Pages marked accessed already */
1229 e4b
->bd_buddy_page
= page
;
1230 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
1232 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
1233 BUG_ON(e4b
->bd_buddy_page
== NULL
);
1240 if (e4b
->bd_bitmap_page
)
1241 put_page(e4b
->bd_bitmap_page
);
1242 if (e4b
->bd_buddy_page
)
1243 put_page(e4b
->bd_buddy_page
);
1244 e4b
->bd_buddy
= NULL
;
1245 e4b
->bd_bitmap
= NULL
;
1249 static int ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
1250 struct ext4_buddy
*e4b
)
1252 return ext4_mb_load_buddy_gfp(sb
, group
, e4b
, GFP_NOFS
);
1255 static void ext4_mb_unload_buddy(struct ext4_buddy
*e4b
)
1257 if (e4b
->bd_bitmap_page
)
1258 put_page(e4b
->bd_bitmap_page
);
1259 if (e4b
->bd_buddy_page
)
1260 put_page(e4b
->bd_buddy_page
);
1264 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
1267 int bb_incr
= 1 << (e4b
->bd_blkbits
- 1);
1270 BUG_ON(e4b
->bd_bitmap
== e4b
->bd_buddy
);
1271 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
1274 while (order
<= e4b
->bd_blkbits
+ 1) {
1276 if (!mb_test_bit(block
, bb
)) {
1277 /* this block is part of buddy of order 'order' */
1287 static void mb_clear_bits(void *bm
, int cur
, int len
)
1293 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1294 /* fast path: clear whole word at once */
1295 addr
= bm
+ (cur
>> 3);
1300 mb_clear_bit(cur
, bm
);
1305 /* clear bits in given range
1306 * will return first found zero bit if any, -1 otherwise
1308 static int mb_test_and_clear_bits(void *bm
, int cur
, int len
)
1315 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1316 /* fast path: clear whole word at once */
1317 addr
= bm
+ (cur
>> 3);
1318 if (*addr
!= (__u32
)(-1) && zero_bit
== -1)
1319 zero_bit
= cur
+ mb_find_next_zero_bit(addr
, 32, 0);
1324 if (!mb_test_and_clear_bit(cur
, bm
) && zero_bit
== -1)
1332 void ext4_set_bits(void *bm
, int cur
, int len
)
1338 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1339 /* fast path: set whole word at once */
1340 addr
= bm
+ (cur
>> 3);
1345 mb_set_bit(cur
, bm
);
1351 * _________________________________________________________________ */
1353 static inline int mb_buddy_adjust_border(int* bit
, void* bitmap
, int side
)
1355 if (mb_test_bit(*bit
+ side
, bitmap
)) {
1356 mb_clear_bit(*bit
, bitmap
);
1362 mb_set_bit(*bit
, bitmap
);
1367 static void mb_buddy_mark_free(struct ext4_buddy
*e4b
, int first
, int last
)
1371 void *buddy
= mb_find_buddy(e4b
, order
, &max
);
1376 /* Bits in range [first; last] are known to be set since
1377 * corresponding blocks were allocated. Bits in range
1378 * (first; last) will stay set because they form buddies on
1379 * upper layer. We just deal with borders if they don't
1380 * align with upper layer and then go up.
1381 * Releasing entire group is all about clearing
1382 * single bit of highest order buddy.
1386 * ---------------------------------
1388 * ---------------------------------
1389 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1390 * ---------------------------------
1392 * \_____________________/
1394 * Neither [1] nor [6] is aligned to above layer.
1395 * Left neighbour [0] is free, so mark it busy,
1396 * decrease bb_counters and extend range to
1398 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1399 * mark [6] free, increase bb_counters and shrink range to
1401 * Then shift range to [0; 2], go up and do the same.
1406 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&first
, buddy
, -1);
1408 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&last
, buddy
, 1);
1413 if (first
== last
|| !(buddy2
= mb_find_buddy(e4b
, order
, &max
))) {
1414 mb_clear_bits(buddy
, first
, last
- first
+ 1);
1415 e4b
->bd_info
->bb_counters
[order
- 1] += last
- first
+ 1;
1424 static void mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1425 int first
, int count
)
1427 int left_is_free
= 0;
1428 int right_is_free
= 0;
1430 int last
= first
+ count
- 1;
1431 struct super_block
*sb
= e4b
->bd_sb
;
1433 if (WARN_ON(count
== 0))
1435 BUG_ON(last
>= (sb
->s_blocksize
<< 3));
1436 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
1437 /* Don't bother if the block group is corrupt. */
1438 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
)))
1441 mb_check_buddy(e4b
);
1442 mb_free_blocks_double(inode
, e4b
, first
, count
);
1444 e4b
->bd_info
->bb_free
+= count
;
1445 if (first
< e4b
->bd_info
->bb_first_free
)
1446 e4b
->bd_info
->bb_first_free
= first
;
1448 /* access memory sequentially: check left neighbour,
1449 * clear range and then check right neighbour
1452 left_is_free
= !mb_test_bit(first
- 1, e4b
->bd_bitmap
);
1453 block
= mb_test_and_clear_bits(e4b
->bd_bitmap
, first
, count
);
1454 if (last
+ 1 < EXT4_SB(sb
)->s_mb_maxs
[0])
1455 right_is_free
= !mb_test_bit(last
+ 1, e4b
->bd_bitmap
);
1457 if (unlikely(block
!= -1)) {
1458 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1459 ext4_fsblk_t blocknr
;
1461 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1462 blocknr
+= EXT4_C2B(EXT4_SB(sb
), block
);
1463 ext4_grp_locked_error(sb
, e4b
->bd_group
,
1464 inode
? inode
->i_ino
: 0,
1466 "freeing already freed block "
1467 "(bit %u); block bitmap corrupt.",
1469 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
))
1470 percpu_counter_sub(&sbi
->s_freeclusters_counter
,
1471 e4b
->bd_info
->bb_free
);
1472 /* Mark the block group as corrupt. */
1473 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT
,
1474 &e4b
->bd_info
->bb_state
);
1475 mb_regenerate_buddy(e4b
);
1479 /* let's maintain fragments counter */
1480 if (left_is_free
&& right_is_free
)
1481 e4b
->bd_info
->bb_fragments
--;
1482 else if (!left_is_free
&& !right_is_free
)
1483 e4b
->bd_info
->bb_fragments
++;
1485 /* buddy[0] == bd_bitmap is a special case, so handle
1486 * it right away and let mb_buddy_mark_free stay free of
1487 * zero order checks.
1488 * Check if neighbours are to be coaleasced,
1489 * adjust bitmap bb_counters and borders appropriately.
1492 first
+= !left_is_free
;
1493 e4b
->bd_info
->bb_counters
[0] += left_is_free
? -1 : 1;
1496 last
-= !right_is_free
;
1497 e4b
->bd_info
->bb_counters
[0] += right_is_free
? -1 : 1;
1501 mb_buddy_mark_free(e4b
, first
>> 1, last
>> 1);
1504 mb_set_largest_free_order(sb
, e4b
->bd_info
);
1505 mb_check_buddy(e4b
);
1508 static int mb_find_extent(struct ext4_buddy
*e4b
, int block
,
1509 int needed
, struct ext4_free_extent
*ex
)
1515 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1518 buddy
= mb_find_buddy(e4b
, 0, &max
);
1519 BUG_ON(buddy
== NULL
);
1520 BUG_ON(block
>= max
);
1521 if (mb_test_bit(block
, buddy
)) {
1528 /* find actual order */
1529 order
= mb_find_order_for_block(e4b
, block
);
1530 block
= block
>> order
;
1532 ex
->fe_len
= 1 << order
;
1533 ex
->fe_start
= block
<< order
;
1534 ex
->fe_group
= e4b
->bd_group
;
1536 /* calc difference from given start */
1537 next
= next
- ex
->fe_start
;
1539 ex
->fe_start
+= next
;
1541 while (needed
> ex
->fe_len
&&
1542 mb_find_buddy(e4b
, order
, &max
)) {
1544 if (block
+ 1 >= max
)
1547 next
= (block
+ 1) * (1 << order
);
1548 if (mb_test_bit(next
, e4b
->bd_bitmap
))
1551 order
= mb_find_order_for_block(e4b
, next
);
1553 block
= next
>> order
;
1554 ex
->fe_len
+= 1 << order
;
1557 if (ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3))) {
1558 /* Should never happen! (but apparently sometimes does?!?) */
1560 ext4_error(e4b
->bd_sb
, "corruption or bug in mb_find_extent "
1561 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
1562 block
, order
, needed
, ex
->fe_group
, ex
->fe_start
,
1563 ex
->fe_len
, ex
->fe_logical
);
1571 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1577 int start
= ex
->fe_start
;
1578 int len
= ex
->fe_len
;
1583 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1584 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1585 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1586 mb_check_buddy(e4b
);
1587 mb_mark_used_double(e4b
, start
, len
);
1589 e4b
->bd_info
->bb_free
-= len
;
1590 if (e4b
->bd_info
->bb_first_free
== start
)
1591 e4b
->bd_info
->bb_first_free
+= len
;
1593 /* let's maintain fragments counter */
1595 mlen
= !mb_test_bit(start
- 1, e4b
->bd_bitmap
);
1596 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1597 max
= !mb_test_bit(start
+ len
, e4b
->bd_bitmap
);
1599 e4b
->bd_info
->bb_fragments
++;
1600 else if (!mlen
&& !max
)
1601 e4b
->bd_info
->bb_fragments
--;
1603 /* let's maintain buddy itself */
1605 ord
= mb_find_order_for_block(e4b
, start
);
1607 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1608 /* the whole chunk may be allocated at once! */
1610 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1611 BUG_ON((start
>> ord
) >= max
);
1612 mb_set_bit(start
>> ord
, buddy
);
1613 e4b
->bd_info
->bb_counters
[ord
]--;
1620 /* store for history */
1622 ret
= len
| (ord
<< 16);
1624 /* we have to split large buddy */
1626 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1627 mb_set_bit(start
>> ord
, buddy
);
1628 e4b
->bd_info
->bb_counters
[ord
]--;
1631 cur
= (start
>> ord
) & ~1U;
1632 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1633 mb_clear_bit(cur
, buddy
);
1634 mb_clear_bit(cur
+ 1, buddy
);
1635 e4b
->bd_info
->bb_counters
[ord
]++;
1636 e4b
->bd_info
->bb_counters
[ord
]++;
1638 mb_set_largest_free_order(e4b
->bd_sb
, e4b
->bd_info
);
1640 ext4_set_bits(e4b
->bd_bitmap
, ex
->fe_start
, len0
);
1641 mb_check_buddy(e4b
);
1647 * Must be called under group lock!
1649 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1650 struct ext4_buddy
*e4b
)
1652 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1655 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1656 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1658 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1659 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1660 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1662 /* preallocation can change ac_b_ex, thus we store actually
1663 * allocated blocks for history */
1664 ac
->ac_f_ex
= ac
->ac_b_ex
;
1666 ac
->ac_status
= AC_STATUS_FOUND
;
1667 ac
->ac_tail
= ret
& 0xffff;
1668 ac
->ac_buddy
= ret
>> 16;
1671 * take the page reference. We want the page to be pinned
1672 * so that we don't get a ext4_mb_init_cache_call for this
1673 * group until we update the bitmap. That would mean we
1674 * double allocate blocks. The reference is dropped
1675 * in ext4_mb_release_context
1677 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1678 get_page(ac
->ac_bitmap_page
);
1679 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1680 get_page(ac
->ac_buddy_page
);
1681 /* store last allocated for subsequent stream allocation */
1682 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
1683 spin_lock(&sbi
->s_md_lock
);
1684 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1685 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1686 spin_unlock(&sbi
->s_md_lock
);
1691 * regular allocator, for general purposes allocation
1694 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1695 struct ext4_buddy
*e4b
,
1698 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1699 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1700 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1701 struct ext4_free_extent ex
;
1704 if (ac
->ac_status
== AC_STATUS_FOUND
)
1707 * We don't want to scan for a whole year
1709 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1710 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1711 ac
->ac_status
= AC_STATUS_BREAK
;
1716 * Haven't found good chunk so far, let's continue
1718 if (bex
->fe_len
< gex
->fe_len
)
1721 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1722 && bex
->fe_group
== e4b
->bd_group
) {
1723 /* recheck chunk's availability - we don't know
1724 * when it was found (within this lock-unlock
1726 max
= mb_find_extent(e4b
, bex
->fe_start
, gex
->fe_len
, &ex
);
1727 if (max
>= gex
->fe_len
) {
1728 ext4_mb_use_best_found(ac
, e4b
);
1735 * The routine checks whether found extent is good enough. If it is,
1736 * then the extent gets marked used and flag is set to the context
1737 * to stop scanning. Otherwise, the extent is compared with the
1738 * previous found extent and if new one is better, then it's stored
1739 * in the context. Later, the best found extent will be used, if
1740 * mballoc can't find good enough extent.
1742 * FIXME: real allocation policy is to be designed yet!
1744 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1745 struct ext4_free_extent
*ex
,
1746 struct ext4_buddy
*e4b
)
1748 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1749 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1751 BUG_ON(ex
->fe_len
<= 0);
1752 BUG_ON(ex
->fe_len
> EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1753 BUG_ON(ex
->fe_start
>= EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1754 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1759 * The special case - take what you catch first
1761 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1763 ext4_mb_use_best_found(ac
, e4b
);
1768 * Let's check whether the chuck is good enough
1770 if (ex
->fe_len
== gex
->fe_len
) {
1772 ext4_mb_use_best_found(ac
, e4b
);
1777 * If this is first found extent, just store it in the context
1779 if (bex
->fe_len
== 0) {
1785 * If new found extent is better, store it in the context
1787 if (bex
->fe_len
< gex
->fe_len
) {
1788 /* if the request isn't satisfied, any found extent
1789 * larger than previous best one is better */
1790 if (ex
->fe_len
> bex
->fe_len
)
1792 } else if (ex
->fe_len
> gex
->fe_len
) {
1793 /* if the request is satisfied, then we try to find
1794 * an extent that still satisfy the request, but is
1795 * smaller than previous one */
1796 if (ex
->fe_len
< bex
->fe_len
)
1800 ext4_mb_check_limits(ac
, e4b
, 0);
1803 static noinline_for_stack
1804 int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1805 struct ext4_buddy
*e4b
)
1807 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1808 ext4_group_t group
= ex
.fe_group
;
1812 BUG_ON(ex
.fe_len
<= 0);
1813 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1817 ext4_lock_group(ac
->ac_sb
, group
);
1818 max
= mb_find_extent(e4b
, ex
.fe_start
, ex
.fe_len
, &ex
);
1822 ext4_mb_use_best_found(ac
, e4b
);
1825 ext4_unlock_group(ac
->ac_sb
, group
);
1826 ext4_mb_unload_buddy(e4b
);
1831 static noinline_for_stack
1832 int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1833 struct ext4_buddy
*e4b
)
1835 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1838 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1839 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1840 struct ext4_free_extent ex
;
1842 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1844 if (grp
->bb_free
== 0)
1847 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1851 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
))) {
1852 ext4_mb_unload_buddy(e4b
);
1856 ext4_lock_group(ac
->ac_sb
, group
);
1857 max
= mb_find_extent(e4b
, ac
->ac_g_ex
.fe_start
,
1858 ac
->ac_g_ex
.fe_len
, &ex
);
1859 ex
.fe_logical
= 0xDEADFA11; /* debug value */
1861 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1864 start
= ext4_group_first_block_no(ac
->ac_sb
, e4b
->bd_group
) +
1866 /* use do_div to get remainder (would be 64-bit modulo) */
1867 if (do_div(start
, sbi
->s_stripe
) == 0) {
1870 ext4_mb_use_best_found(ac
, e4b
);
1872 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1873 BUG_ON(ex
.fe_len
<= 0);
1874 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1875 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1878 ext4_mb_use_best_found(ac
, e4b
);
1879 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1880 /* Sometimes, caller may want to merge even small
1881 * number of blocks to an existing extent */
1882 BUG_ON(ex
.fe_len
<= 0);
1883 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1884 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1887 ext4_mb_use_best_found(ac
, e4b
);
1889 ext4_unlock_group(ac
->ac_sb
, group
);
1890 ext4_mb_unload_buddy(e4b
);
1896 * The routine scans buddy structures (not bitmap!) from given order
1897 * to max order and tries to find big enough chunk to satisfy the req
1899 static noinline_for_stack
1900 void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1901 struct ext4_buddy
*e4b
)
1903 struct super_block
*sb
= ac
->ac_sb
;
1904 struct ext4_group_info
*grp
= e4b
->bd_info
;
1910 BUG_ON(ac
->ac_2order
<= 0);
1911 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1912 if (grp
->bb_counters
[i
] == 0)
1915 buddy
= mb_find_buddy(e4b
, i
, &max
);
1916 BUG_ON(buddy
== NULL
);
1918 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1923 ac
->ac_b_ex
.fe_len
= 1 << i
;
1924 ac
->ac_b_ex
.fe_start
= k
<< i
;
1925 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1927 ext4_mb_use_best_found(ac
, e4b
);
1929 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1931 if (EXT4_SB(sb
)->s_mb_stats
)
1932 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1939 * The routine scans the group and measures all found extents.
1940 * In order to optimize scanning, caller must pass number of
1941 * free blocks in the group, so the routine can know upper limit.
1943 static noinline_for_stack
1944 void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1945 struct ext4_buddy
*e4b
)
1947 struct super_block
*sb
= ac
->ac_sb
;
1948 void *bitmap
= e4b
->bd_bitmap
;
1949 struct ext4_free_extent ex
;
1953 free
= e4b
->bd_info
->bb_free
;
1956 i
= e4b
->bd_info
->bb_first_free
;
1958 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1959 i
= mb_find_next_zero_bit(bitmap
,
1960 EXT4_CLUSTERS_PER_GROUP(sb
), i
);
1961 if (i
>= EXT4_CLUSTERS_PER_GROUP(sb
)) {
1963 * IF we have corrupt bitmap, we won't find any
1964 * free blocks even though group info says we
1965 * we have free blocks
1967 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1968 "%d free clusters as per "
1969 "group info. But bitmap says 0",
1974 mb_find_extent(e4b
, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1975 BUG_ON(ex
.fe_len
<= 0);
1976 if (free
< ex
.fe_len
) {
1977 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1978 "%d free clusters as per "
1979 "group info. But got %d blocks",
1982 * The number of free blocks differs. This mostly
1983 * indicate that the bitmap is corrupt. So exit
1984 * without claiming the space.
1988 ex
.fe_logical
= 0xDEADC0DE; /* debug value */
1989 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1995 ext4_mb_check_limits(ac
, e4b
, 1);
1999 * This is a special case for storages like raid5
2000 * we try to find stripe-aligned chunks for stripe-size-multiple requests
2002 static noinline_for_stack
2003 void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
2004 struct ext4_buddy
*e4b
)
2006 struct super_block
*sb
= ac
->ac_sb
;
2007 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2008 void *bitmap
= e4b
->bd_bitmap
;
2009 struct ext4_free_extent ex
;
2010 ext4_fsblk_t first_group_block
;
2015 BUG_ON(sbi
->s_stripe
== 0);
2017 /* find first stripe-aligned block in group */
2018 first_group_block
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
2020 a
= first_group_block
+ sbi
->s_stripe
- 1;
2021 do_div(a
, sbi
->s_stripe
);
2022 i
= (a
* sbi
->s_stripe
) - first_group_block
;
2024 while (i
< EXT4_CLUSTERS_PER_GROUP(sb
)) {
2025 if (!mb_test_bit(i
, bitmap
)) {
2026 max
= mb_find_extent(e4b
, i
, sbi
->s_stripe
, &ex
);
2027 if (max
>= sbi
->s_stripe
) {
2029 ex
.fe_logical
= 0xDEADF00D; /* debug value */
2031 ext4_mb_use_best_found(ac
, e4b
);
2040 * This is now called BEFORE we load the buddy bitmap.
2041 * Returns either 1 or 0 indicating that the group is either suitable
2042 * for the allocation or not. In addition it can also return negative
2043 * error code when something goes wrong.
2045 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
2046 ext4_group_t group
, int cr
)
2048 unsigned free
, fragments
;
2049 int flex_size
= ext4_flex_bg_size(EXT4_SB(ac
->ac_sb
));
2050 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
2052 BUG_ON(cr
< 0 || cr
>= 4);
2054 free
= grp
->bb_free
;
2057 if (cr
<= 2 && free
< ac
->ac_g_ex
.fe_len
)
2060 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp
)))
2063 /* We only do this if the grp has never been initialized */
2064 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
2065 int ret
= ext4_mb_init_group(ac
->ac_sb
, group
, GFP_NOFS
);
2070 fragments
= grp
->bb_fragments
;
2076 BUG_ON(ac
->ac_2order
== 0);
2078 /* Avoid using the first bg of a flexgroup for data files */
2079 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
) &&
2080 (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) &&
2081 ((group
% flex_size
) == 0))
2084 if ((ac
->ac_2order
> ac
->ac_sb
->s_blocksize_bits
+1) ||
2085 (free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2088 if (grp
->bb_largest_free_order
< ac
->ac_2order
)
2093 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2097 if (free
>= ac
->ac_g_ex
.fe_len
)
2109 static noinline_for_stack
int
2110 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
2112 ext4_group_t ngroups
, group
, i
;
2114 int err
= 0, first_err
= 0;
2115 struct ext4_sb_info
*sbi
;
2116 struct super_block
*sb
;
2117 struct ext4_buddy e4b
;
2121 ngroups
= ext4_get_groups_count(sb
);
2122 /* non-extent files are limited to low blocks/groups */
2123 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)))
2124 ngroups
= sbi
->s_blockfile_groups
;
2126 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
2128 /* first, try the goal */
2129 err
= ext4_mb_find_by_goal(ac
, &e4b
);
2130 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
2133 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2137 * ac->ac2_order is set only if the fe_len is a power of 2
2138 * if ac2_order is set we also set criteria to 0 so that we
2139 * try exact allocation using buddy.
2141 i
= fls(ac
->ac_g_ex
.fe_len
);
2144 * We search using buddy data only if the order of the request
2145 * is greater than equal to the sbi_s_mb_order2_reqs
2146 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2147 * We also support searching for power-of-two requests only for
2148 * requests upto maximum buddy size we have constructed.
2150 if (i
>= sbi
->s_mb_order2_reqs
&& i
<= sb
->s_blocksize_bits
+ 2) {
2152 * This should tell if fe_len is exactly power of 2
2154 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
2155 ac
->ac_2order
= i
- 1;
2158 /* if stream allocation is enabled, use global goal */
2159 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
2160 /* TBD: may be hot point */
2161 spin_lock(&sbi
->s_md_lock
);
2162 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
2163 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
2164 spin_unlock(&sbi
->s_md_lock
);
2167 /* Let's just scan groups to find more-less suitable blocks */
2168 cr
= ac
->ac_2order
? 0 : 1;
2170 * cr == 0 try to get exact allocation,
2171 * cr == 3 try to get anything
2174 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
2175 ac
->ac_criteria
= cr
;
2177 * searching for the right group start
2178 * from the goal value specified
2180 group
= ac
->ac_g_ex
.fe_group
;
2182 for (i
= 0; i
< ngroups
; group
++, i
++) {
2186 * Artificially restricted ngroups for non-extent
2187 * files makes group > ngroups possible on first loop.
2189 if (group
>= ngroups
)
2192 /* This now checks without needing the buddy page */
2193 ret
= ext4_mb_good_group(ac
, group
, cr
);
2200 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2204 ext4_lock_group(sb
, group
);
2207 * We need to check again after locking the
2210 ret
= ext4_mb_good_group(ac
, group
, cr
);
2212 ext4_unlock_group(sb
, group
);
2213 ext4_mb_unload_buddy(&e4b
);
2219 ac
->ac_groups_scanned
++;
2221 ext4_mb_simple_scan_group(ac
, &e4b
);
2222 else if (cr
== 1 && sbi
->s_stripe
&&
2223 !(ac
->ac_g_ex
.fe_len
% sbi
->s_stripe
))
2224 ext4_mb_scan_aligned(ac
, &e4b
);
2226 ext4_mb_complex_scan_group(ac
, &e4b
);
2228 ext4_unlock_group(sb
, group
);
2229 ext4_mb_unload_buddy(&e4b
);
2231 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
2236 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
2237 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
2239 * We've been searching too long. Let's try to allocate
2240 * the best chunk we've found so far
2243 ext4_mb_try_best_found(ac
, &e4b
);
2244 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
2246 * Someone more lucky has already allocated it.
2247 * The only thing we can do is just take first
2249 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2251 ac
->ac_b_ex
.fe_group
= 0;
2252 ac
->ac_b_ex
.fe_start
= 0;
2253 ac
->ac_b_ex
.fe_len
= 0;
2254 ac
->ac_status
= AC_STATUS_CONTINUE
;
2255 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
2257 atomic_inc(&sbi
->s_mb_lost_chunks
);
2262 if (!err
&& ac
->ac_status
!= AC_STATUS_FOUND
&& first_err
)
2267 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2269 struct super_block
*sb
= seq
->private;
2272 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2275 return (void *) ((unsigned long) group
);
2278 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2280 struct super_block
*sb
= seq
->private;
2284 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2287 return (void *) ((unsigned long) group
);
2290 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2292 struct super_block
*sb
= seq
->private;
2293 ext4_group_t group
= (ext4_group_t
) ((unsigned long) v
);
2295 int err
, buddy_loaded
= 0;
2296 struct ext4_buddy e4b
;
2297 struct ext4_group_info
*grinfo
;
2298 unsigned char blocksize_bits
= min_t(unsigned char,
2299 sb
->s_blocksize_bits
,
2300 EXT4_MAX_BLOCK_LOG_SIZE
);
2302 struct ext4_group_info info
;
2303 ext4_grpblk_t counters
[EXT4_MAX_BLOCK_LOG_SIZE
+ 2];
2308 seq_puts(seq
, "#group: free frags first ["
2309 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
2310 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
2312 i
= (blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2313 sizeof(struct ext4_group_info
);
2315 grinfo
= ext4_get_group_info(sb
, group
);
2316 /* Load the group info in memory only if not already loaded. */
2317 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo
))) {
2318 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2320 seq_printf(seq
, "#%-5u: I/O error\n", group
);
2326 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2329 ext4_mb_unload_buddy(&e4b
);
2331 seq_printf(seq
, "#%-5u: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2332 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2333 for (i
= 0; i
<= 13; i
++)
2334 seq_printf(seq
, " %-5u", i
<= blocksize_bits
+ 1 ?
2335 sg
.info
.bb_counters
[i
] : 0);
2336 seq_printf(seq
, " ]\n");
2341 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2345 static const struct seq_operations ext4_mb_seq_groups_ops
= {
2346 .start
= ext4_mb_seq_groups_start
,
2347 .next
= ext4_mb_seq_groups_next
,
2348 .stop
= ext4_mb_seq_groups_stop
,
2349 .show
= ext4_mb_seq_groups_show
,
2352 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2354 struct super_block
*sb
= PDE_DATA(inode
);
2357 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2359 struct seq_file
*m
= file
->private_data
;
2366 const struct file_operations ext4_seq_mb_groups_fops
= {
2367 .open
= ext4_mb_seq_groups_open
,
2369 .llseek
= seq_lseek
,
2370 .release
= seq_release
,
2373 static struct kmem_cache
*get_groupinfo_cache(int blocksize_bits
)
2375 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2376 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[cache_index
];
2383 * Allocate the top-level s_group_info array for the specified number
2386 int ext4_mb_alloc_groupinfo(struct super_block
*sb
, ext4_group_t ngroups
)
2388 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2390 struct ext4_group_info
***new_groupinfo
;
2392 size
= (ngroups
+ EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2393 EXT4_DESC_PER_BLOCK_BITS(sb
);
2394 if (size
<= sbi
->s_group_info_size
)
2397 size
= roundup_pow_of_two(sizeof(*sbi
->s_group_info
) * size
);
2398 new_groupinfo
= kvzalloc(size
, GFP_KERNEL
);
2399 if (!new_groupinfo
) {
2400 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy meta group");
2403 if (sbi
->s_group_info
) {
2404 memcpy(new_groupinfo
, sbi
->s_group_info
,
2405 sbi
->s_group_info_size
* sizeof(*sbi
->s_group_info
));
2406 kvfree(sbi
->s_group_info
);
2408 sbi
->s_group_info
= new_groupinfo
;
2409 sbi
->s_group_info_size
= size
/ sizeof(*sbi
->s_group_info
);
2410 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2411 sbi
->s_group_info_size
);
2415 /* Create and initialize ext4_group_info data for the given group. */
2416 int ext4_mb_add_groupinfo(struct super_block
*sb
, ext4_group_t group
,
2417 struct ext4_group_desc
*desc
)
2421 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2422 struct ext4_group_info
**meta_group_info
;
2423 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2426 * First check if this group is the first of a reserved block.
2427 * If it's true, we have to allocate a new table of pointers
2428 * to ext4_group_info structures
2430 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2431 metalen
= sizeof(*meta_group_info
) <<
2432 EXT4_DESC_PER_BLOCK_BITS(sb
);
2433 meta_group_info
= kmalloc(metalen
, GFP_NOFS
);
2434 if (meta_group_info
== NULL
) {
2435 ext4_msg(sb
, KERN_ERR
, "can't allocate mem "
2436 "for a buddy group");
2437 goto exit_meta_group_info
;
2439 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] =
2444 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2445 i
= group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2447 meta_group_info
[i
] = kmem_cache_zalloc(cachep
, GFP_NOFS
);
2448 if (meta_group_info
[i
] == NULL
) {
2449 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy mem");
2450 goto exit_group_info
;
2452 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2453 &(meta_group_info
[i
]->bb_state
));
2456 * initialize bb_free to be able to skip
2457 * empty groups without initialization
2459 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2460 meta_group_info
[i
]->bb_free
=
2461 ext4_free_clusters_after_init(sb
, group
, desc
);
2463 meta_group_info
[i
]->bb_free
=
2464 ext4_free_group_clusters(sb
, desc
);
2467 INIT_LIST_HEAD(&meta_group_info
[i
]->bb_prealloc_list
);
2468 init_rwsem(&meta_group_info
[i
]->alloc_sem
);
2469 meta_group_info
[i
]->bb_free_root
= RB_ROOT
;
2470 meta_group_info
[i
]->bb_largest_free_order
= -1; /* uninit */
2474 struct buffer_head
*bh
;
2475 meta_group_info
[i
]->bb_bitmap
=
2476 kmalloc(sb
->s_blocksize
, GFP_NOFS
);
2477 BUG_ON(meta_group_info
[i
]->bb_bitmap
== NULL
);
2478 bh
= ext4_read_block_bitmap(sb
, group
);
2479 BUG_ON(IS_ERR_OR_NULL(bh
));
2480 memcpy(meta_group_info
[i
]->bb_bitmap
, bh
->b_data
,
2489 /* If a meta_group_info table has been allocated, release it now */
2490 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2491 kfree(sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)]);
2492 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] = NULL
;
2494 exit_meta_group_info
:
2496 } /* ext4_mb_add_groupinfo */
2498 static int ext4_mb_init_backend(struct super_block
*sb
)
2500 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2502 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2504 struct ext4_group_desc
*desc
;
2505 struct kmem_cache
*cachep
;
2507 err
= ext4_mb_alloc_groupinfo(sb
, ngroups
);
2511 sbi
->s_buddy_cache
= new_inode(sb
);
2512 if (sbi
->s_buddy_cache
== NULL
) {
2513 ext4_msg(sb
, KERN_ERR
, "can't get new inode");
2516 /* To avoid potentially colliding with an valid on-disk inode number,
2517 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2518 * not in the inode hash, so it should never be found by iget(), but
2519 * this will avoid confusion if it ever shows up during debugging. */
2520 sbi
->s_buddy_cache
->i_ino
= EXT4_BAD_INO
;
2521 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2522 for (i
= 0; i
< ngroups
; i
++) {
2523 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2525 ext4_msg(sb
, KERN_ERR
, "can't read descriptor %u", i
);
2528 if (ext4_mb_add_groupinfo(sb
, i
, desc
) != 0)
2535 cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2537 kmem_cache_free(cachep
, ext4_get_group_info(sb
, i
));
2538 i
= sbi
->s_group_info_size
;
2540 kfree(sbi
->s_group_info
[i
]);
2541 iput(sbi
->s_buddy_cache
);
2543 kvfree(sbi
->s_group_info
);
2547 static void ext4_groupinfo_destroy_slabs(void)
2551 for (i
= 0; i
< NR_GRPINFO_CACHES
; i
++) {
2552 if (ext4_groupinfo_caches
[i
])
2553 kmem_cache_destroy(ext4_groupinfo_caches
[i
]);
2554 ext4_groupinfo_caches
[i
] = NULL
;
2558 static int ext4_groupinfo_create_slab(size_t size
)
2560 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex
);
2562 int blocksize_bits
= order_base_2(size
);
2563 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2564 struct kmem_cache
*cachep
;
2566 if (cache_index
>= NR_GRPINFO_CACHES
)
2569 if (unlikely(cache_index
< 0))
2572 mutex_lock(&ext4_grpinfo_slab_create_mutex
);
2573 if (ext4_groupinfo_caches
[cache_index
]) {
2574 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2575 return 0; /* Already created */
2578 slab_size
= offsetof(struct ext4_group_info
,
2579 bb_counters
[blocksize_bits
+ 2]);
2581 cachep
= kmem_cache_create(ext4_groupinfo_slab_names
[cache_index
],
2582 slab_size
, 0, SLAB_RECLAIM_ACCOUNT
,
2585 ext4_groupinfo_caches
[cache_index
] = cachep
;
2587 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2590 "EXT4-fs: no memory for groupinfo slab cache\n");
2597 int ext4_mb_init(struct super_block
*sb
)
2599 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2601 unsigned offset
, offset_incr
;
2605 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_offsets
);
2607 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2608 if (sbi
->s_mb_offsets
== NULL
) {
2613 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_maxs
);
2614 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2615 if (sbi
->s_mb_maxs
== NULL
) {
2620 ret
= ext4_groupinfo_create_slab(sb
->s_blocksize
);
2624 /* order 0 is regular bitmap */
2625 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2626 sbi
->s_mb_offsets
[0] = 0;
2630 offset_incr
= 1 << (sb
->s_blocksize_bits
- 1);
2631 max
= sb
->s_blocksize
<< 2;
2633 sbi
->s_mb_offsets
[i
] = offset
;
2634 sbi
->s_mb_maxs
[i
] = max
;
2635 offset
+= offset_incr
;
2636 offset_incr
= offset_incr
>> 1;
2639 } while (i
<= sb
->s_blocksize_bits
+ 1);
2641 spin_lock_init(&sbi
->s_md_lock
);
2642 spin_lock_init(&sbi
->s_bal_lock
);
2643 sbi
->s_mb_free_pending
= 0;
2644 INIT_LIST_HEAD(&sbi
->s_freed_data_list
);
2646 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2647 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2648 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2649 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2650 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2652 * The default group preallocation is 512, which for 4k block
2653 * sizes translates to 2 megabytes. However for bigalloc file
2654 * systems, this is probably too big (i.e, if the cluster size
2655 * is 1 megabyte, then group preallocation size becomes half a
2656 * gigabyte!). As a default, we will keep a two megabyte
2657 * group pralloc size for cluster sizes up to 64k, and after
2658 * that, we will force a minimum group preallocation size of
2659 * 32 clusters. This translates to 8 megs when the cluster
2660 * size is 256k, and 32 megs when the cluster size is 1 meg,
2661 * which seems reasonable as a default.
2663 sbi
->s_mb_group_prealloc
= max(MB_DEFAULT_GROUP_PREALLOC
>>
2664 sbi
->s_cluster_bits
, 32);
2666 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2667 * to the lowest multiple of s_stripe which is bigger than
2668 * the s_mb_group_prealloc as determined above. We want
2669 * the preallocation size to be an exact multiple of the
2670 * RAID stripe size so that preallocations don't fragment
2673 if (sbi
->s_stripe
> 1) {
2674 sbi
->s_mb_group_prealloc
= roundup(
2675 sbi
->s_mb_group_prealloc
, sbi
->s_stripe
);
2678 sbi
->s_locality_groups
= alloc_percpu(struct ext4_locality_group
);
2679 if (sbi
->s_locality_groups
== NULL
) {
2683 for_each_possible_cpu(i
) {
2684 struct ext4_locality_group
*lg
;
2685 lg
= per_cpu_ptr(sbi
->s_locality_groups
, i
);
2686 mutex_init(&lg
->lg_mutex
);
2687 for (j
= 0; j
< PREALLOC_TB_SIZE
; j
++)
2688 INIT_LIST_HEAD(&lg
->lg_prealloc_list
[j
]);
2689 spin_lock_init(&lg
->lg_prealloc_lock
);
2692 /* init file for buddy data */
2693 ret
= ext4_mb_init_backend(sb
);
2695 goto out_free_locality_groups
;
2699 out_free_locality_groups
:
2700 free_percpu(sbi
->s_locality_groups
);
2701 sbi
->s_locality_groups
= NULL
;
2703 kfree(sbi
->s_mb_offsets
);
2704 sbi
->s_mb_offsets
= NULL
;
2705 kfree(sbi
->s_mb_maxs
);
2706 sbi
->s_mb_maxs
= NULL
;
2710 /* need to called with the ext4 group lock held */
2711 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2713 struct ext4_prealloc_space
*pa
;
2714 struct list_head
*cur
, *tmp
;
2717 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2718 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2719 list_del(&pa
->pa_group_list
);
2721 kmem_cache_free(ext4_pspace_cachep
, pa
);
2724 mb_debug(1, "mballoc: %u PAs left\n", count
);
2728 int ext4_mb_release(struct super_block
*sb
)
2730 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2732 int num_meta_group_infos
;
2733 struct ext4_group_info
*grinfo
;
2734 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2735 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2737 if (sbi
->s_group_info
) {
2738 for (i
= 0; i
< ngroups
; i
++) {
2739 grinfo
= ext4_get_group_info(sb
, i
);
2741 kfree(grinfo
->bb_bitmap
);
2743 ext4_lock_group(sb
, i
);
2744 ext4_mb_cleanup_pa(grinfo
);
2745 ext4_unlock_group(sb
, i
);
2746 kmem_cache_free(cachep
, grinfo
);
2748 num_meta_group_infos
= (ngroups
+
2749 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2750 EXT4_DESC_PER_BLOCK_BITS(sb
);
2751 for (i
= 0; i
< num_meta_group_infos
; i
++)
2752 kfree(sbi
->s_group_info
[i
]);
2753 kvfree(sbi
->s_group_info
);
2755 kfree(sbi
->s_mb_offsets
);
2756 kfree(sbi
->s_mb_maxs
);
2757 iput(sbi
->s_buddy_cache
);
2758 if (sbi
->s_mb_stats
) {
2759 ext4_msg(sb
, KERN_INFO
,
2760 "mballoc: %u blocks %u reqs (%u success)",
2761 atomic_read(&sbi
->s_bal_allocated
),
2762 atomic_read(&sbi
->s_bal_reqs
),
2763 atomic_read(&sbi
->s_bal_success
));
2764 ext4_msg(sb
, KERN_INFO
,
2765 "mballoc: %u extents scanned, %u goal hits, "
2766 "%u 2^N hits, %u breaks, %u lost",
2767 atomic_read(&sbi
->s_bal_ex_scanned
),
2768 atomic_read(&sbi
->s_bal_goals
),
2769 atomic_read(&sbi
->s_bal_2orders
),
2770 atomic_read(&sbi
->s_bal_breaks
),
2771 atomic_read(&sbi
->s_mb_lost_chunks
));
2772 ext4_msg(sb
, KERN_INFO
,
2773 "mballoc: %lu generated and it took %Lu",
2774 sbi
->s_mb_buddies_generated
,
2775 sbi
->s_mb_generation_time
);
2776 ext4_msg(sb
, KERN_INFO
,
2777 "mballoc: %u preallocated, %u discarded",
2778 atomic_read(&sbi
->s_mb_preallocated
),
2779 atomic_read(&sbi
->s_mb_discarded
));
2782 free_percpu(sbi
->s_locality_groups
);
2787 static inline int ext4_issue_discard(struct super_block
*sb
,
2788 ext4_group_t block_group
, ext4_grpblk_t cluster
, int count
,
2791 ext4_fsblk_t discard_block
;
2793 discard_block
= (EXT4_C2B(EXT4_SB(sb
), cluster
) +
2794 ext4_group_first_block_no(sb
, block_group
));
2795 count
= EXT4_C2B(EXT4_SB(sb
), count
);
2796 trace_ext4_discard_blocks(sb
,
2797 (unsigned long long) discard_block
, count
);
2799 return __blkdev_issue_discard(sb
->s_bdev
,
2800 (sector_t
)discard_block
<< (sb
->s_blocksize_bits
- 9),
2801 (sector_t
)count
<< (sb
->s_blocksize_bits
- 9),
2804 return sb_issue_discard(sb
, discard_block
, count
, GFP_NOFS
, 0);
2807 static void ext4_free_data_in_buddy(struct super_block
*sb
,
2808 struct ext4_free_data
*entry
)
2810 struct ext4_buddy e4b
;
2811 struct ext4_group_info
*db
;
2812 int err
, count
= 0, count2
= 0;
2814 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2815 entry
->efd_count
, entry
->efd_group
, entry
);
2817 err
= ext4_mb_load_buddy(sb
, entry
->efd_group
, &e4b
);
2818 /* we expect to find existing buddy because it's pinned */
2821 spin_lock(&EXT4_SB(sb
)->s_md_lock
);
2822 EXT4_SB(sb
)->s_mb_free_pending
-= entry
->efd_count
;
2823 spin_unlock(&EXT4_SB(sb
)->s_md_lock
);
2826 /* there are blocks to put in buddy to make them really free */
2827 count
+= entry
->efd_count
;
2829 ext4_lock_group(sb
, entry
->efd_group
);
2830 /* Take it out of per group rb tree */
2831 rb_erase(&entry
->efd_node
, &(db
->bb_free_root
));
2832 mb_free_blocks(NULL
, &e4b
, entry
->efd_start_cluster
, entry
->efd_count
);
2835 * Clear the trimmed flag for the group so that the next
2836 * ext4_trim_fs can trim it.
2837 * If the volume is mounted with -o discard, online discard
2838 * is supported and the free blocks will be trimmed online.
2840 if (!test_opt(sb
, DISCARD
))
2841 EXT4_MB_GRP_CLEAR_TRIMMED(db
);
2843 if (!db
->bb_free_root
.rb_node
) {
2844 /* No more items in the per group rb tree
2845 * balance refcounts from ext4_mb_free_metadata()
2847 put_page(e4b
.bd_buddy_page
);
2848 put_page(e4b
.bd_bitmap_page
);
2850 ext4_unlock_group(sb
, entry
->efd_group
);
2851 kmem_cache_free(ext4_free_data_cachep
, entry
);
2852 ext4_mb_unload_buddy(&e4b
);
2854 mb_debug(1, "freed %u blocks in %u structures\n", count
, count2
);
2858 * This function is called by the jbd2 layer once the commit has finished,
2859 * so we know we can free the blocks that were released with that commit.
2861 void ext4_process_freed_data(struct super_block
*sb
, tid_t commit_tid
)
2863 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2864 struct ext4_free_data
*entry
, *tmp
;
2865 struct bio
*discard_bio
= NULL
;
2866 struct list_head freed_data_list
;
2867 struct list_head
*cut_pos
= NULL
;
2870 INIT_LIST_HEAD(&freed_data_list
);
2872 spin_lock(&sbi
->s_md_lock
);
2873 list_for_each_entry(entry
, &sbi
->s_freed_data_list
, efd_list
) {
2874 if (entry
->efd_tid
!= commit_tid
)
2876 cut_pos
= &entry
->efd_list
;
2879 list_cut_position(&freed_data_list
, &sbi
->s_freed_data_list
,
2881 spin_unlock(&sbi
->s_md_lock
);
2883 if (test_opt(sb
, DISCARD
)) {
2884 list_for_each_entry(entry
, &freed_data_list
, efd_list
) {
2885 err
= ext4_issue_discard(sb
, entry
->efd_group
,
2886 entry
->efd_start_cluster
,
2889 if (err
&& err
!= -EOPNOTSUPP
) {
2890 ext4_msg(sb
, KERN_WARNING
, "discard request in"
2891 " group:%d block:%d count:%d failed"
2892 " with %d", entry
->efd_group
,
2893 entry
->efd_start_cluster
,
2894 entry
->efd_count
, err
);
2895 } else if (err
== -EOPNOTSUPP
)
2900 submit_bio_wait(discard_bio
);
2901 bio_put(discard_bio
);
2905 list_for_each_entry_safe(entry
, tmp
, &freed_data_list
, efd_list
)
2906 ext4_free_data_in_buddy(sb
, entry
);
2909 int __init
ext4_init_mballoc(void)
2911 ext4_pspace_cachep
= KMEM_CACHE(ext4_prealloc_space
,
2912 SLAB_RECLAIM_ACCOUNT
);
2913 if (ext4_pspace_cachep
== NULL
)
2916 ext4_ac_cachep
= KMEM_CACHE(ext4_allocation_context
,
2917 SLAB_RECLAIM_ACCOUNT
);
2918 if (ext4_ac_cachep
== NULL
) {
2919 kmem_cache_destroy(ext4_pspace_cachep
);
2923 ext4_free_data_cachep
= KMEM_CACHE(ext4_free_data
,
2924 SLAB_RECLAIM_ACCOUNT
);
2925 if (ext4_free_data_cachep
== NULL
) {
2926 kmem_cache_destroy(ext4_pspace_cachep
);
2927 kmem_cache_destroy(ext4_ac_cachep
);
2933 void ext4_exit_mballoc(void)
2936 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2937 * before destroying the slab cache.
2940 kmem_cache_destroy(ext4_pspace_cachep
);
2941 kmem_cache_destroy(ext4_ac_cachep
);
2942 kmem_cache_destroy(ext4_free_data_cachep
);
2943 ext4_groupinfo_destroy_slabs();
2948 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2949 * Returns 0 if success or error code
2951 static noinline_for_stack
int
2952 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2953 handle_t
*handle
, unsigned int reserv_clstrs
)
2955 struct buffer_head
*bitmap_bh
= NULL
;
2956 struct ext4_group_desc
*gdp
;
2957 struct buffer_head
*gdp_bh
;
2958 struct ext4_sb_info
*sbi
;
2959 struct super_block
*sb
;
2963 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2964 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2969 bitmap_bh
= ext4_read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2970 if (IS_ERR(bitmap_bh
)) {
2971 err
= PTR_ERR(bitmap_bh
);
2976 BUFFER_TRACE(bitmap_bh
, "getting write access");
2977 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2982 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2986 ext4_debug("using block group %u(%d)\n", ac
->ac_b_ex
.fe_group
,
2987 ext4_free_group_clusters(sb
, gdp
));
2989 BUFFER_TRACE(gdp_bh
, "get_write_access");
2990 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2994 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
2996 len
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
2997 if (!ext4_data_block_valid(sbi
, block
, len
)) {
2998 ext4_error(sb
, "Allocating blocks %llu-%llu which overlap "
2999 "fs metadata", block
, block
+len
);
3000 /* File system mounted not to panic on error
3001 * Fix the bitmap and return EFSCORRUPTED
3002 * We leak some of the blocks here.
3004 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3005 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
3006 ac
->ac_b_ex
.fe_len
);
3007 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3008 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
3010 err
= -EFSCORRUPTED
;
3014 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3015 #ifdef AGGRESSIVE_CHECK
3018 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
3019 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
3020 bitmap_bh
->b_data
));
3024 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
3025 ac
->ac_b_ex
.fe_len
);
3026 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
3027 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
3028 ext4_free_group_clusters_set(sb
, gdp
,
3029 ext4_free_clusters_after_init(sb
,
3030 ac
->ac_b_ex
.fe_group
, gdp
));
3032 len
= ext4_free_group_clusters(sb
, gdp
) - ac
->ac_b_ex
.fe_len
;
3033 ext4_free_group_clusters_set(sb
, gdp
, len
);
3034 ext4_block_bitmap_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
, bitmap_bh
);
3035 ext4_group_desc_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
);
3037 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3038 percpu_counter_sub(&sbi
->s_freeclusters_counter
, ac
->ac_b_ex
.fe_len
);
3040 * Now reduce the dirty block count also. Should not go negative
3042 if (!(ac
->ac_flags
& EXT4_MB_DELALLOC_RESERVED
))
3043 /* release all the reserved blocks if non delalloc */
3044 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
3047 if (sbi
->s_log_groups_per_flex
) {
3048 ext4_group_t flex_group
= ext4_flex_group(sbi
,
3049 ac
->ac_b_ex
.fe_group
);
3050 atomic64_sub(ac
->ac_b_ex
.fe_len
,
3051 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
3054 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
3057 err
= ext4_handle_dirty_metadata(handle
, NULL
, gdp_bh
);
3065 * here we normalize request for locality group
3066 * Group request are normalized to s_mb_group_prealloc, which goes to
3067 * s_strip if we set the same via mount option.
3068 * s_mb_group_prealloc can be configured via
3069 * /sys/fs/ext4/<partition>/mb_group_prealloc
3071 * XXX: should we try to preallocate more than the group has now?
3073 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
3075 struct super_block
*sb
= ac
->ac_sb
;
3076 struct ext4_locality_group
*lg
= ac
->ac_lg
;
3079 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
3080 mb_debug(1, "#%u: goal %u blocks for locality group\n",
3081 current
->pid
, ac
->ac_g_ex
.fe_len
);
3085 * Normalization means making request better in terms of
3086 * size and alignment
3088 static noinline_for_stack
void
3089 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
3090 struct ext4_allocation_request
*ar
)
3092 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3095 loff_t size
, start_off
;
3096 loff_t orig_size __maybe_unused
;
3098 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3099 struct ext4_prealloc_space
*pa
;
3101 /* do normalize only data requests, metadata requests
3102 do not need preallocation */
3103 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3106 /* sometime caller may want exact blocks */
3107 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3110 /* caller may indicate that preallocation isn't
3111 * required (it's a tail, for example) */
3112 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
3115 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
3116 ext4_mb_normalize_group_request(ac
);
3120 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3122 /* first, let's learn actual file size
3123 * given current request is allocated */
3124 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
3125 size
= size
<< bsbits
;
3126 if (size
< i_size_read(ac
->ac_inode
))
3127 size
= i_size_read(ac
->ac_inode
);
3130 /* max size of free chunks */
3133 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3134 (req <= (size) || max <= (chunk_size))
3136 /* first, try to predict filesize */
3137 /* XXX: should this table be tunable? */
3139 if (size
<= 16 * 1024) {
3141 } else if (size
<= 32 * 1024) {
3143 } else if (size
<= 64 * 1024) {
3145 } else if (size
<= 128 * 1024) {
3147 } else if (size
<= 256 * 1024) {
3149 } else if (size
<= 512 * 1024) {
3151 } else if (size
<= 1024 * 1024) {
3153 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
3154 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3155 (21 - bsbits
)) << 21;
3156 size
= 2 * 1024 * 1024;
3157 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
3158 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3159 (22 - bsbits
)) << 22;
3160 size
= 4 * 1024 * 1024;
3161 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
3162 (8<<20)>>bsbits
, max
, 8 * 1024)) {
3163 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3164 (23 - bsbits
)) << 23;
3165 size
= 8 * 1024 * 1024;
3167 start_off
= (loff_t
) ac
->ac_o_ex
.fe_logical
<< bsbits
;
3168 size
= (loff_t
) EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3169 ac
->ac_o_ex
.fe_len
) << bsbits
;
3171 size
= size
>> bsbits
;
3172 start
= start_off
>> bsbits
;
3174 /* don't cover already allocated blocks in selected range */
3175 if (ar
->pleft
&& start
<= ar
->lleft
) {
3176 size
-= ar
->lleft
+ 1 - start
;
3177 start
= ar
->lleft
+ 1;
3179 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
3180 size
-= start
+ size
- ar
->lright
;
3183 * Trim allocation request for filesystems with artificially small
3186 if (size
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
))
3187 size
= EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
);
3191 /* check we don't cross already preallocated blocks */
3193 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3198 spin_lock(&pa
->pa_lock
);
3199 if (pa
->pa_deleted
) {
3200 spin_unlock(&pa
->pa_lock
);
3204 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3207 /* PA must not overlap original request */
3208 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
3209 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
3211 /* skip PAs this normalized request doesn't overlap with */
3212 if (pa
->pa_lstart
>= end
|| pa_end
<= start
) {
3213 spin_unlock(&pa
->pa_lock
);
3216 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
3218 /* adjust start or end to be adjacent to this pa */
3219 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
3220 BUG_ON(pa_end
< start
);
3222 } else if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
3223 BUG_ON(pa
->pa_lstart
> end
);
3224 end
= pa
->pa_lstart
;
3226 spin_unlock(&pa
->pa_lock
);
3231 /* XXX: extra loop to check we really don't overlap preallocations */
3233 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3236 spin_lock(&pa
->pa_lock
);
3237 if (pa
->pa_deleted
== 0) {
3238 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3240 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3242 spin_unlock(&pa
->pa_lock
);
3246 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3247 start
> ac
->ac_o_ex
.fe_logical
) {
3248 ext4_msg(ac
->ac_sb
, KERN_ERR
,
3249 "start %lu, size %lu, fe_logical %lu",
3250 (unsigned long) start
, (unsigned long) size
,
3251 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3254 BUG_ON(size
<= 0 || size
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3256 /* now prepare goal request */
3258 /* XXX: is it better to align blocks WRT to logical
3259 * placement or satisfy big request as is */
3260 ac
->ac_g_ex
.fe_logical
= start
;
3261 ac
->ac_g_ex
.fe_len
= EXT4_NUM_B2C(sbi
, size
);
3263 /* define goal start in order to merge */
3264 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3265 /* merge to the right */
3266 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3267 &ac
->ac_f_ex
.fe_group
,
3268 &ac
->ac_f_ex
.fe_start
);
3269 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3271 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3272 /* merge to the left */
3273 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3274 &ac
->ac_f_ex
.fe_group
,
3275 &ac
->ac_f_ex
.fe_start
);
3276 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3279 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3280 (unsigned) orig_size
, (unsigned) start
);
3283 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3285 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3287 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3288 atomic_inc(&sbi
->s_bal_reqs
);
3289 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3290 if (ac
->ac_b_ex
.fe_len
>= ac
->ac_o_ex
.fe_len
)
3291 atomic_inc(&sbi
->s_bal_success
);
3292 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3293 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3294 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3295 atomic_inc(&sbi
->s_bal_goals
);
3296 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3297 atomic_inc(&sbi
->s_bal_breaks
);
3300 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
)
3301 trace_ext4_mballoc_alloc(ac
);
3303 trace_ext4_mballoc_prealloc(ac
);
3307 * Called on failure; free up any blocks from the inode PA for this
3308 * context. We don't need this for MB_GROUP_PA because we only change
3309 * pa_free in ext4_mb_release_context(), but on failure, we've already
3310 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3312 static void ext4_discard_allocated_blocks(struct ext4_allocation_context
*ac
)
3314 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
3315 struct ext4_buddy e4b
;
3319 if (ac
->ac_f_ex
.fe_len
== 0)
3321 err
= ext4_mb_load_buddy(ac
->ac_sb
, ac
->ac_f_ex
.fe_group
, &e4b
);
3324 * This should never happen since we pin the
3325 * pages in the ext4_allocation_context so
3326 * ext4_mb_load_buddy() should never fail.
3328 WARN(1, "mb_load_buddy failed (%d)", err
);
3331 ext4_lock_group(ac
->ac_sb
, ac
->ac_f_ex
.fe_group
);
3332 mb_free_blocks(ac
->ac_inode
, &e4b
, ac
->ac_f_ex
.fe_start
,
3333 ac
->ac_f_ex
.fe_len
);
3334 ext4_unlock_group(ac
->ac_sb
, ac
->ac_f_ex
.fe_group
);
3335 ext4_mb_unload_buddy(&e4b
);
3338 if (pa
->pa_type
== MB_INODE_PA
)
3339 pa
->pa_free
+= ac
->ac_b_ex
.fe_len
;
3343 * use blocks preallocated to inode
3345 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3346 struct ext4_prealloc_space
*pa
)
3348 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3353 /* found preallocated blocks, use them */
3354 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3355 end
= min(pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
),
3356 start
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
));
3357 len
= EXT4_NUM_B2C(sbi
, end
- start
);
3358 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3359 &ac
->ac_b_ex
.fe_start
);
3360 ac
->ac_b_ex
.fe_len
= len
;
3361 ac
->ac_status
= AC_STATUS_FOUND
;
3364 BUG_ON(start
< pa
->pa_pstart
);
3365 BUG_ON(end
> pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
));
3366 BUG_ON(pa
->pa_free
< len
);
3369 mb_debug(1, "use %llu/%u from inode pa %p\n", start
, len
, pa
);
3373 * use blocks preallocated to locality group
3375 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3376 struct ext4_prealloc_space
*pa
)
3378 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3380 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3381 &ac
->ac_b_ex
.fe_group
,
3382 &ac
->ac_b_ex
.fe_start
);
3383 ac
->ac_b_ex
.fe_len
= len
;
3384 ac
->ac_status
= AC_STATUS_FOUND
;
3387 /* we don't correct pa_pstart or pa_plen here to avoid
3388 * possible race when the group is being loaded concurrently
3389 * instead we correct pa later, after blocks are marked
3390 * in on-disk bitmap -- see ext4_mb_release_context()
3391 * Other CPUs are prevented from allocating from this pa by lg_mutex
3393 mb_debug(1, "use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3397 * Return the prealloc space that have minimal distance
3398 * from the goal block. @cpa is the prealloc
3399 * space that is having currently known minimal distance
3400 * from the goal block.
3402 static struct ext4_prealloc_space
*
3403 ext4_mb_check_group_pa(ext4_fsblk_t goal_block
,
3404 struct ext4_prealloc_space
*pa
,
3405 struct ext4_prealloc_space
*cpa
)
3407 ext4_fsblk_t cur_distance
, new_distance
;
3410 atomic_inc(&pa
->pa_count
);
3413 cur_distance
= abs(goal_block
- cpa
->pa_pstart
);
3414 new_distance
= abs(goal_block
- pa
->pa_pstart
);
3416 if (cur_distance
<= new_distance
)
3419 /* drop the previous reference */
3420 atomic_dec(&cpa
->pa_count
);
3421 atomic_inc(&pa
->pa_count
);
3426 * search goal blocks in preallocated space
3428 static noinline_for_stack
int
3429 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3431 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3433 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3434 struct ext4_locality_group
*lg
;
3435 struct ext4_prealloc_space
*pa
, *cpa
= NULL
;
3436 ext4_fsblk_t goal_block
;
3438 /* only data can be preallocated */
3439 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3442 /* first, try per-file preallocation */
3444 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3446 /* all fields in this condition don't change,
3447 * so we can skip locking for them */
3448 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3449 ac
->ac_o_ex
.fe_logical
>= (pa
->pa_lstart
+
3450 EXT4_C2B(sbi
, pa
->pa_len
)))
3453 /* non-extent files can't have physical blocks past 2^32 */
3454 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)) &&
3455 (pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
) >
3456 EXT4_MAX_BLOCK_FILE_PHYS
))
3459 /* found preallocated blocks, use them */
3460 spin_lock(&pa
->pa_lock
);
3461 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3462 atomic_inc(&pa
->pa_count
);
3463 ext4_mb_use_inode_pa(ac
, pa
);
3464 spin_unlock(&pa
->pa_lock
);
3465 ac
->ac_criteria
= 10;
3469 spin_unlock(&pa
->pa_lock
);
3473 /* can we use group allocation? */
3474 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3477 /* inode may have no locality group for some reason */
3481 order
= fls(ac
->ac_o_ex
.fe_len
) - 1;
3482 if (order
> PREALLOC_TB_SIZE
- 1)
3483 /* The max size of hash table is PREALLOC_TB_SIZE */
3484 order
= PREALLOC_TB_SIZE
- 1;
3486 goal_block
= ext4_grp_offs_to_block(ac
->ac_sb
, &ac
->ac_g_ex
);
3488 * search for the prealloc space that is having
3489 * minimal distance from the goal block.
3491 for (i
= order
; i
< PREALLOC_TB_SIZE
; i
++) {
3493 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[i
],
3495 spin_lock(&pa
->pa_lock
);
3496 if (pa
->pa_deleted
== 0 &&
3497 pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3499 cpa
= ext4_mb_check_group_pa(goal_block
,
3502 spin_unlock(&pa
->pa_lock
);
3507 ext4_mb_use_group_pa(ac
, cpa
);
3508 ac
->ac_criteria
= 20;
3515 * the function goes through all block freed in the group
3516 * but not yet committed and marks them used in in-core bitmap.
3517 * buddy must be generated from this bitmap
3518 * Need to be called with the ext4 group lock held
3520 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
3524 struct ext4_group_info
*grp
;
3525 struct ext4_free_data
*entry
;
3527 grp
= ext4_get_group_info(sb
, group
);
3528 n
= rb_first(&(grp
->bb_free_root
));
3531 entry
= rb_entry(n
, struct ext4_free_data
, efd_node
);
3532 ext4_set_bits(bitmap
, entry
->efd_start_cluster
, entry
->efd_count
);
3539 * the function goes through all preallocation in this group and marks them
3540 * used in in-core bitmap. buddy must be generated from this bitmap
3541 * Need to be called with ext4 group lock held
3543 static noinline_for_stack
3544 void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3547 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3548 struct ext4_prealloc_space
*pa
;
3549 struct list_head
*cur
;
3550 ext4_group_t groupnr
;
3551 ext4_grpblk_t start
;
3552 int preallocated
= 0;
3555 /* all form of preallocation discards first load group,
3556 * so the only competing code is preallocation use.
3557 * we don't need any locking here
3558 * notice we do NOT ignore preallocations with pa_deleted
3559 * otherwise we could leave used blocks available for
3560 * allocation in buddy when concurrent ext4_mb_put_pa()
3561 * is dropping preallocation
3563 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3564 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3565 spin_lock(&pa
->pa_lock
);
3566 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3569 spin_unlock(&pa
->pa_lock
);
3570 if (unlikely(len
== 0))
3572 BUG_ON(groupnr
!= group
);
3573 ext4_set_bits(bitmap
, start
, len
);
3574 preallocated
+= len
;
3576 mb_debug(1, "preallocated %u for group %u\n", preallocated
, group
);
3579 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3581 struct ext4_prealloc_space
*pa
;
3582 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3584 BUG_ON(atomic_read(&pa
->pa_count
));
3585 BUG_ON(pa
->pa_deleted
== 0);
3586 kmem_cache_free(ext4_pspace_cachep
, pa
);
3590 * drops a reference to preallocated space descriptor
3591 * if this was the last reference and the space is consumed
3593 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3594 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3597 ext4_fsblk_t grp_blk
;
3599 /* in this short window concurrent discard can set pa_deleted */
3600 spin_lock(&pa
->pa_lock
);
3601 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0) {
3602 spin_unlock(&pa
->pa_lock
);
3606 if (pa
->pa_deleted
== 1) {
3607 spin_unlock(&pa
->pa_lock
);
3612 spin_unlock(&pa
->pa_lock
);
3614 grp_blk
= pa
->pa_pstart
;
3616 * If doing group-based preallocation, pa_pstart may be in the
3617 * next group when pa is used up
3619 if (pa
->pa_type
== MB_GROUP_PA
)
3622 grp
= ext4_get_group_number(sb
, grp_blk
);
3627 * P1 (buddy init) P2 (regular allocation)
3628 * find block B in PA
3629 * copy on-disk bitmap to buddy
3630 * mark B in on-disk bitmap
3631 * drop PA from group
3632 * mark all PAs in buddy
3634 * thus, P1 initializes buddy with B available. to prevent this
3635 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3638 ext4_lock_group(sb
, grp
);
3639 list_del(&pa
->pa_group_list
);
3640 ext4_unlock_group(sb
, grp
);
3642 spin_lock(pa
->pa_obj_lock
);
3643 list_del_rcu(&pa
->pa_inode_list
);
3644 spin_unlock(pa
->pa_obj_lock
);
3646 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3650 * creates new preallocated space for given inode
3652 static noinline_for_stack
int
3653 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3655 struct super_block
*sb
= ac
->ac_sb
;
3656 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3657 struct ext4_prealloc_space
*pa
;
3658 struct ext4_group_info
*grp
;
3659 struct ext4_inode_info
*ei
;
3661 /* preallocate only when found space is larger then requested */
3662 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3663 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3664 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3666 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3670 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3676 /* we can't allocate as much as normalizer wants.
3677 * so, found space must get proper lstart
3678 * to cover original request */
3679 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3680 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3682 /* we're limited by original request in that
3683 * logical block must be covered any way
3684 * winl is window we can move our chunk within */
3685 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3687 /* also, we should cover whole original request */
3688 wins
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
);
3690 /* the smallest one defines real window */
3691 win
= min(winl
, wins
);
3693 offs
= ac
->ac_o_ex
.fe_logical
%
3694 EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
3695 if (offs
&& offs
< win
)
3698 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
-
3699 EXT4_NUM_B2C(sbi
, win
);
3700 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3701 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3704 /* preallocation can change ac_b_ex, thus we store actually
3705 * allocated blocks for history */
3706 ac
->ac_f_ex
= ac
->ac_b_ex
;
3708 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3709 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3710 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3711 pa
->pa_free
= pa
->pa_len
;
3712 atomic_set(&pa
->pa_count
, 1);
3713 spin_lock_init(&pa
->pa_lock
);
3714 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3715 INIT_LIST_HEAD(&pa
->pa_group_list
);
3717 pa
->pa_type
= MB_INODE_PA
;
3719 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa
,
3720 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3721 trace_ext4_mb_new_inode_pa(ac
, pa
);
3723 ext4_mb_use_inode_pa(ac
, pa
);
3724 atomic_add(pa
->pa_free
, &sbi
->s_mb_preallocated
);
3726 ei
= EXT4_I(ac
->ac_inode
);
3727 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3729 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3730 pa
->pa_inode
= ac
->ac_inode
;
3732 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3733 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3734 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3736 spin_lock(pa
->pa_obj_lock
);
3737 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3738 spin_unlock(pa
->pa_obj_lock
);
3744 * creates new preallocated space for locality group inodes belongs to
3746 static noinline_for_stack
int
3747 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3749 struct super_block
*sb
= ac
->ac_sb
;
3750 struct ext4_locality_group
*lg
;
3751 struct ext4_prealloc_space
*pa
;
3752 struct ext4_group_info
*grp
;
3754 /* preallocate only when found space is larger then requested */
3755 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3756 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3757 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3759 BUG_ON(ext4_pspace_cachep
== NULL
);
3760 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3764 /* preallocation can change ac_b_ex, thus we store actually
3765 * allocated blocks for history */
3766 ac
->ac_f_ex
= ac
->ac_b_ex
;
3768 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3769 pa
->pa_lstart
= pa
->pa_pstart
;
3770 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3771 pa
->pa_free
= pa
->pa_len
;
3772 atomic_set(&pa
->pa_count
, 1);
3773 spin_lock_init(&pa
->pa_lock
);
3774 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3775 INIT_LIST_HEAD(&pa
->pa_group_list
);
3777 pa
->pa_type
= MB_GROUP_PA
;
3779 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa
,
3780 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3781 trace_ext4_mb_new_group_pa(ac
, pa
);
3783 ext4_mb_use_group_pa(ac
, pa
);
3784 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3786 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3790 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3791 pa
->pa_inode
= NULL
;
3793 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3794 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3795 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3798 * We will later add the new pa to the right bucket
3799 * after updating the pa_free in ext4_mb_release_context
3804 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3808 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3809 err
= ext4_mb_new_group_pa(ac
);
3811 err
= ext4_mb_new_inode_pa(ac
);
3816 * finds all unused blocks in on-disk bitmap, frees them in
3817 * in-core bitmap and buddy.
3818 * @pa must be unlinked from inode and group lists, so that
3819 * nobody else can find/use it.
3820 * the caller MUST hold group/inode locks.
3821 * TODO: optimize the case when there are no in-core structures yet
3823 static noinline_for_stack
int
3824 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3825 struct ext4_prealloc_space
*pa
)
3827 struct super_block
*sb
= e4b
->bd_sb
;
3828 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3833 unsigned long long grp_blk_start
;
3837 BUG_ON(pa
->pa_deleted
== 0);
3838 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3839 grp_blk_start
= pa
->pa_pstart
- EXT4_C2B(sbi
, bit
);
3840 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3841 end
= bit
+ pa
->pa_len
;
3844 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3847 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3848 mb_debug(1, " free preallocated %u/%u in group %u\n",
3849 (unsigned) ext4_group_first_block_no(sb
, group
) + bit
,
3850 (unsigned) next
- bit
, (unsigned) group
);
3853 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, next
- bit
);
3854 trace_ext4_mb_release_inode_pa(pa
, (grp_blk_start
+
3855 EXT4_C2B(sbi
, bit
)),
3857 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3860 if (free
!= pa
->pa_free
) {
3861 ext4_msg(e4b
->bd_sb
, KERN_CRIT
,
3862 "pa %p: logic %lu, phys. %lu, len %lu",
3863 pa
, (unsigned long) pa
->pa_lstart
,
3864 (unsigned long) pa
->pa_pstart
,
3865 (unsigned long) pa
->pa_len
);
3866 ext4_grp_locked_error(sb
, group
, 0, 0, "free %u, pa_free %u",
3869 * pa is already deleted so we use the value obtained
3870 * from the bitmap and continue.
3873 atomic_add(free
, &sbi
->s_mb_discarded
);
3878 static noinline_for_stack
int
3879 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3880 struct ext4_prealloc_space
*pa
)
3882 struct super_block
*sb
= e4b
->bd_sb
;
3886 trace_ext4_mb_release_group_pa(sb
, pa
);
3887 BUG_ON(pa
->pa_deleted
== 0);
3888 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3889 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3890 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3891 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3892 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, pa
->pa_len
);
3898 * releases all preallocations in given group
3900 * first, we need to decide discard policy:
3901 * - when do we discard
3903 * - how many do we discard
3904 * 1) how many requested
3906 static noinline_for_stack
int
3907 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3908 ext4_group_t group
, int needed
)
3910 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3911 struct buffer_head
*bitmap_bh
= NULL
;
3912 struct ext4_prealloc_space
*pa
, *tmp
;
3913 struct list_head list
;
3914 struct ext4_buddy e4b
;
3919 mb_debug(1, "discard preallocation for group %u\n", group
);
3921 if (list_empty(&grp
->bb_prealloc_list
))
3924 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3925 if (IS_ERR(bitmap_bh
)) {
3926 err
= PTR_ERR(bitmap_bh
);
3927 ext4_error(sb
, "Error %d reading block bitmap for %u",
3932 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3934 ext4_warning(sb
, "Error %d loading buddy information for %u",
3941 needed
= EXT4_CLUSTERS_PER_GROUP(sb
) + 1;
3943 INIT_LIST_HEAD(&list
);
3945 ext4_lock_group(sb
, group
);
3946 list_for_each_entry_safe(pa
, tmp
,
3947 &grp
->bb_prealloc_list
, pa_group_list
) {
3948 spin_lock(&pa
->pa_lock
);
3949 if (atomic_read(&pa
->pa_count
)) {
3950 spin_unlock(&pa
->pa_lock
);
3954 if (pa
->pa_deleted
) {
3955 spin_unlock(&pa
->pa_lock
);
3959 /* seems this one can be freed ... */
3962 /* we can trust pa_free ... */
3963 free
+= pa
->pa_free
;
3965 spin_unlock(&pa
->pa_lock
);
3967 list_del(&pa
->pa_group_list
);
3968 list_add(&pa
->u
.pa_tmp_list
, &list
);
3971 /* if we still need more blocks and some PAs were used, try again */
3972 if (free
< needed
&& busy
) {
3974 ext4_unlock_group(sb
, group
);
3979 /* found anything to free? */
3980 if (list_empty(&list
)) {
3985 /* now free all selected PAs */
3986 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3988 /* remove from object (inode or locality group) */
3989 spin_lock(pa
->pa_obj_lock
);
3990 list_del_rcu(&pa
->pa_inode_list
);
3991 spin_unlock(pa
->pa_obj_lock
);
3993 if (pa
->pa_type
== MB_GROUP_PA
)
3994 ext4_mb_release_group_pa(&e4b
, pa
);
3996 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3998 list_del(&pa
->u
.pa_tmp_list
);
3999 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4003 ext4_unlock_group(sb
, group
);
4004 ext4_mb_unload_buddy(&e4b
);
4010 * releases all non-used preallocated blocks for given inode
4012 * It's important to discard preallocations under i_data_sem
4013 * We don't want another block to be served from the prealloc
4014 * space when we are discarding the inode prealloc space.
4016 * FIXME!! Make sure it is valid at all the call sites
4018 void ext4_discard_preallocations(struct inode
*inode
)
4020 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4021 struct super_block
*sb
= inode
->i_sb
;
4022 struct buffer_head
*bitmap_bh
= NULL
;
4023 struct ext4_prealloc_space
*pa
, *tmp
;
4024 ext4_group_t group
= 0;
4025 struct list_head list
;
4026 struct ext4_buddy e4b
;
4029 if (!S_ISREG(inode
->i_mode
)) {
4030 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
4034 mb_debug(1, "discard preallocation for inode %lu\n", inode
->i_ino
);
4035 trace_ext4_discard_preallocations(inode
);
4037 INIT_LIST_HEAD(&list
);
4040 /* first, collect all pa's in the inode */
4041 spin_lock(&ei
->i_prealloc_lock
);
4042 while (!list_empty(&ei
->i_prealloc_list
)) {
4043 pa
= list_entry(ei
->i_prealloc_list
.next
,
4044 struct ext4_prealloc_space
, pa_inode_list
);
4045 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
4046 spin_lock(&pa
->pa_lock
);
4047 if (atomic_read(&pa
->pa_count
)) {
4048 /* this shouldn't happen often - nobody should
4049 * use preallocation while we're discarding it */
4050 spin_unlock(&pa
->pa_lock
);
4051 spin_unlock(&ei
->i_prealloc_lock
);
4052 ext4_msg(sb
, KERN_ERR
,
4053 "uh-oh! used pa while discarding");
4055 schedule_timeout_uninterruptible(HZ
);
4059 if (pa
->pa_deleted
== 0) {
4061 spin_unlock(&pa
->pa_lock
);
4062 list_del_rcu(&pa
->pa_inode_list
);
4063 list_add(&pa
->u
.pa_tmp_list
, &list
);
4067 /* someone is deleting pa right now */
4068 spin_unlock(&pa
->pa_lock
);
4069 spin_unlock(&ei
->i_prealloc_lock
);
4071 /* we have to wait here because pa_deleted
4072 * doesn't mean pa is already unlinked from
4073 * the list. as we might be called from
4074 * ->clear_inode() the inode will get freed
4075 * and concurrent thread which is unlinking
4076 * pa from inode's list may access already
4077 * freed memory, bad-bad-bad */
4079 /* XXX: if this happens too often, we can
4080 * add a flag to force wait only in case
4081 * of ->clear_inode(), but not in case of
4082 * regular truncate */
4083 schedule_timeout_uninterruptible(HZ
);
4086 spin_unlock(&ei
->i_prealloc_lock
);
4088 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
4089 BUG_ON(pa
->pa_type
!= MB_INODE_PA
);
4090 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
4092 err
= ext4_mb_load_buddy_gfp(sb
, group
, &e4b
,
4093 GFP_NOFS
|__GFP_NOFAIL
);
4095 ext4_error(sb
, "Error %d loading buddy information for %u",
4100 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
4101 if (IS_ERR(bitmap_bh
)) {
4102 err
= PTR_ERR(bitmap_bh
);
4103 ext4_error(sb
, "Error %d reading block bitmap for %u",
4105 ext4_mb_unload_buddy(&e4b
);
4109 ext4_lock_group(sb
, group
);
4110 list_del(&pa
->pa_group_list
);
4111 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
4112 ext4_unlock_group(sb
, group
);
4114 ext4_mb_unload_buddy(&e4b
);
4117 list_del(&pa
->u
.pa_tmp_list
);
4118 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4122 #ifdef CONFIG_EXT4_DEBUG
4123 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4125 struct super_block
*sb
= ac
->ac_sb
;
4126 ext4_group_t ngroups
, i
;
4128 if (!ext4_mballoc_debug
||
4129 (EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
))
4132 ext4_msg(ac
->ac_sb
, KERN_ERR
, "Can't allocate:"
4133 " Allocation context details:");
4134 ext4_msg(ac
->ac_sb
, KERN_ERR
, "status %d flags %d",
4135 ac
->ac_status
, ac
->ac_flags
);
4136 ext4_msg(ac
->ac_sb
, KERN_ERR
, "orig %lu/%lu/%lu@%lu, "
4137 "goal %lu/%lu/%lu@%lu, "
4138 "best %lu/%lu/%lu@%lu cr %d",
4139 (unsigned long)ac
->ac_o_ex
.fe_group
,
4140 (unsigned long)ac
->ac_o_ex
.fe_start
,
4141 (unsigned long)ac
->ac_o_ex
.fe_len
,
4142 (unsigned long)ac
->ac_o_ex
.fe_logical
,
4143 (unsigned long)ac
->ac_g_ex
.fe_group
,
4144 (unsigned long)ac
->ac_g_ex
.fe_start
,
4145 (unsigned long)ac
->ac_g_ex
.fe_len
,
4146 (unsigned long)ac
->ac_g_ex
.fe_logical
,
4147 (unsigned long)ac
->ac_b_ex
.fe_group
,
4148 (unsigned long)ac
->ac_b_ex
.fe_start
,
4149 (unsigned long)ac
->ac_b_ex
.fe_len
,
4150 (unsigned long)ac
->ac_b_ex
.fe_logical
,
4151 (int)ac
->ac_criteria
);
4152 ext4_msg(ac
->ac_sb
, KERN_ERR
, "%d found", ac
->ac_found
);
4153 ext4_msg(ac
->ac_sb
, KERN_ERR
, "groups: ");
4154 ngroups
= ext4_get_groups_count(sb
);
4155 for (i
= 0; i
< ngroups
; i
++) {
4156 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
4157 struct ext4_prealloc_space
*pa
;
4158 ext4_grpblk_t start
;
4159 struct list_head
*cur
;
4160 ext4_lock_group(sb
, i
);
4161 list_for_each(cur
, &grp
->bb_prealloc_list
) {
4162 pa
= list_entry(cur
, struct ext4_prealloc_space
,
4164 spin_lock(&pa
->pa_lock
);
4165 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
4167 spin_unlock(&pa
->pa_lock
);
4168 printk(KERN_ERR
"PA:%u:%d:%u \n", i
,
4171 ext4_unlock_group(sb
, i
);
4173 if (grp
->bb_free
== 0)
4175 printk(KERN_ERR
"%u: %d/%d \n",
4176 i
, grp
->bb_free
, grp
->bb_fragments
);
4178 printk(KERN_ERR
"\n");
4181 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4188 * We use locality group preallocation for small size file. The size of the
4189 * file is determined by the current size or the resulting size after
4190 * allocation which ever is larger
4192 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4194 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
4196 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4197 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
4200 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
4203 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
4206 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
4207 isize
= (i_size_read(ac
->ac_inode
) + ac
->ac_sb
->s_blocksize
- 1)
4210 if ((size
== isize
) &&
4211 !ext4_fs_is_busy(sbi
) &&
4212 (atomic_read(&ac
->ac_inode
->i_writecount
) == 0)) {
4213 ac
->ac_flags
|= EXT4_MB_HINT_NOPREALLOC
;
4217 if (sbi
->s_mb_group_prealloc
<= 0) {
4218 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4222 /* don't use group allocation for large files */
4223 size
= max(size
, isize
);
4224 if (size
> sbi
->s_mb_stream_request
) {
4225 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4229 BUG_ON(ac
->ac_lg
!= NULL
);
4231 * locality group prealloc space are per cpu. The reason for having
4232 * per cpu locality group is to reduce the contention between block
4233 * request from multiple CPUs.
4235 ac
->ac_lg
= raw_cpu_ptr(sbi
->s_locality_groups
);
4237 /* we're going to use group allocation */
4238 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
4240 /* serialize all allocations in the group */
4241 mutex_lock(&ac
->ac_lg
->lg_mutex
);
4244 static noinline_for_stack
int
4245 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
4246 struct ext4_allocation_request
*ar
)
4248 struct super_block
*sb
= ar
->inode
->i_sb
;
4249 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4250 struct ext4_super_block
*es
= sbi
->s_es
;
4254 ext4_grpblk_t block
;
4256 /* we can't allocate > group size */
4259 /* just a dirty hack to filter too big requests */
4260 if (len
>= EXT4_CLUSTERS_PER_GROUP(sb
))
4261 len
= EXT4_CLUSTERS_PER_GROUP(sb
);
4263 /* start searching from the goal */
4265 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
4266 goal
>= ext4_blocks_count(es
))
4267 goal
= le32_to_cpu(es
->s_first_data_block
);
4268 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
4270 /* set up allocation goals */
4271 ac
->ac_b_ex
.fe_logical
= EXT4_LBLK_CMASK(sbi
, ar
->logical
);
4272 ac
->ac_status
= AC_STATUS_CONTINUE
;
4274 ac
->ac_inode
= ar
->inode
;
4275 ac
->ac_o_ex
.fe_logical
= ac
->ac_b_ex
.fe_logical
;
4276 ac
->ac_o_ex
.fe_group
= group
;
4277 ac
->ac_o_ex
.fe_start
= block
;
4278 ac
->ac_o_ex
.fe_len
= len
;
4279 ac
->ac_g_ex
= ac
->ac_o_ex
;
4280 ac
->ac_flags
= ar
->flags
;
4282 /* we have to define context: we'll we work with a file or
4283 * locality group. this is a policy, actually */
4284 ext4_mb_group_or_file(ac
);
4286 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4287 "left: %u/%u, right %u/%u to %swritable\n",
4288 (unsigned) ar
->len
, (unsigned) ar
->logical
,
4289 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
4290 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
4291 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
4292 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
4297 static noinline_for_stack
void
4298 ext4_mb_discard_lg_preallocations(struct super_block
*sb
,
4299 struct ext4_locality_group
*lg
,
4300 int order
, int total_entries
)
4302 ext4_group_t group
= 0;
4303 struct ext4_buddy e4b
;
4304 struct list_head discard_list
;
4305 struct ext4_prealloc_space
*pa
, *tmp
;
4307 mb_debug(1, "discard locality group preallocation\n");
4309 INIT_LIST_HEAD(&discard_list
);
4311 spin_lock(&lg
->lg_prealloc_lock
);
4312 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[order
],
4314 spin_lock(&pa
->pa_lock
);
4315 if (atomic_read(&pa
->pa_count
)) {
4317 * This is the pa that we just used
4318 * for block allocation. So don't
4321 spin_unlock(&pa
->pa_lock
);
4324 if (pa
->pa_deleted
) {
4325 spin_unlock(&pa
->pa_lock
);
4328 /* only lg prealloc space */
4329 BUG_ON(pa
->pa_type
!= MB_GROUP_PA
);
4331 /* seems this one can be freed ... */
4333 spin_unlock(&pa
->pa_lock
);
4335 list_del_rcu(&pa
->pa_inode_list
);
4336 list_add(&pa
->u
.pa_tmp_list
, &discard_list
);
4339 if (total_entries
<= 5) {
4341 * we want to keep only 5 entries
4342 * allowing it to grow to 8. This
4343 * mak sure we don't call discard
4344 * soon for this list.
4349 spin_unlock(&lg
->lg_prealloc_lock
);
4351 list_for_each_entry_safe(pa
, tmp
, &discard_list
, u
.pa_tmp_list
) {
4354 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
4355 err
= ext4_mb_load_buddy_gfp(sb
, group
, &e4b
,
4356 GFP_NOFS
|__GFP_NOFAIL
);
4358 ext4_error(sb
, "Error %d loading buddy information for %u",
4362 ext4_lock_group(sb
, group
);
4363 list_del(&pa
->pa_group_list
);
4364 ext4_mb_release_group_pa(&e4b
, pa
);
4365 ext4_unlock_group(sb
, group
);
4367 ext4_mb_unload_buddy(&e4b
);
4368 list_del(&pa
->u
.pa_tmp_list
);
4369 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4374 * We have incremented pa_count. So it cannot be freed at this
4375 * point. Also we hold lg_mutex. So no parallel allocation is
4376 * possible from this lg. That means pa_free cannot be updated.
4378 * A parallel ext4_mb_discard_group_preallocations is possible.
4379 * which can cause the lg_prealloc_list to be updated.
4382 static void ext4_mb_add_n_trim(struct ext4_allocation_context
*ac
)
4384 int order
, added
= 0, lg_prealloc_count
= 1;
4385 struct super_block
*sb
= ac
->ac_sb
;
4386 struct ext4_locality_group
*lg
= ac
->ac_lg
;
4387 struct ext4_prealloc_space
*tmp_pa
, *pa
= ac
->ac_pa
;
4389 order
= fls(pa
->pa_free
) - 1;
4390 if (order
> PREALLOC_TB_SIZE
- 1)
4391 /* The max size of hash table is PREALLOC_TB_SIZE */
4392 order
= PREALLOC_TB_SIZE
- 1;
4393 /* Add the prealloc space to lg */
4394 spin_lock(&lg
->lg_prealloc_lock
);
4395 list_for_each_entry_rcu(tmp_pa
, &lg
->lg_prealloc_list
[order
],
4397 spin_lock(&tmp_pa
->pa_lock
);
4398 if (tmp_pa
->pa_deleted
) {
4399 spin_unlock(&tmp_pa
->pa_lock
);
4402 if (!added
&& pa
->pa_free
< tmp_pa
->pa_free
) {
4403 /* Add to the tail of the previous entry */
4404 list_add_tail_rcu(&pa
->pa_inode_list
,
4405 &tmp_pa
->pa_inode_list
);
4408 * we want to count the total
4409 * number of entries in the list
4412 spin_unlock(&tmp_pa
->pa_lock
);
4413 lg_prealloc_count
++;
4416 list_add_tail_rcu(&pa
->pa_inode_list
,
4417 &lg
->lg_prealloc_list
[order
]);
4418 spin_unlock(&lg
->lg_prealloc_lock
);
4420 /* Now trim the list to be not more than 8 elements */
4421 if (lg_prealloc_count
> 8) {
4422 ext4_mb_discard_lg_preallocations(sb
, lg
,
4423 order
, lg_prealloc_count
);
4430 * release all resource we used in allocation
4432 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
4434 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4435 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
4437 if (pa
->pa_type
== MB_GROUP_PA
) {
4438 /* see comment in ext4_mb_use_group_pa() */
4439 spin_lock(&pa
->pa_lock
);
4440 pa
->pa_pstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4441 pa
->pa_lstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4442 pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
4443 pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
4444 spin_unlock(&pa
->pa_lock
);
4449 * We want to add the pa to the right bucket.
4450 * Remove it from the list and while adding
4451 * make sure the list to which we are adding
4454 if ((pa
->pa_type
== MB_GROUP_PA
) && likely(pa
->pa_free
)) {
4455 spin_lock(pa
->pa_obj_lock
);
4456 list_del_rcu(&pa
->pa_inode_list
);
4457 spin_unlock(pa
->pa_obj_lock
);
4458 ext4_mb_add_n_trim(ac
);
4460 ext4_mb_put_pa(ac
, ac
->ac_sb
, pa
);
4462 if (ac
->ac_bitmap_page
)
4463 put_page(ac
->ac_bitmap_page
);
4464 if (ac
->ac_buddy_page
)
4465 put_page(ac
->ac_buddy_page
);
4466 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
4467 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
4468 ext4_mb_collect_stats(ac
);
4472 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
4474 ext4_group_t i
, ngroups
= ext4_get_groups_count(sb
);
4478 trace_ext4_mb_discard_preallocations(sb
, needed
);
4479 for (i
= 0; i
< ngroups
&& needed
> 0; i
++) {
4480 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4489 * Main entry point into mballoc to allocate blocks
4490 * it tries to use preallocation first, then falls back
4491 * to usual allocation
4493 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4494 struct ext4_allocation_request
*ar
, int *errp
)
4497 struct ext4_allocation_context
*ac
= NULL
;
4498 struct ext4_sb_info
*sbi
;
4499 struct super_block
*sb
;
4500 ext4_fsblk_t block
= 0;
4501 unsigned int inquota
= 0;
4502 unsigned int reserv_clstrs
= 0;
4505 sb
= ar
->inode
->i_sb
;
4508 trace_ext4_request_blocks(ar
);
4510 /* Allow to use superuser reservation for quota file */
4511 if (ext4_is_quota_file(ar
->inode
))
4512 ar
->flags
|= EXT4_MB_USE_ROOT_BLOCKS
;
4514 if ((ar
->flags
& EXT4_MB_DELALLOC_RESERVED
) == 0) {
4515 /* Without delayed allocation we need to verify
4516 * there is enough free blocks to do block allocation
4517 * and verify allocation doesn't exceed the quota limits.
4520 ext4_claim_free_clusters(sbi
, ar
->len
, ar
->flags
)) {
4522 /* let others to free the space */
4524 ar
->len
= ar
->len
>> 1;
4530 reserv_clstrs
= ar
->len
;
4531 if (ar
->flags
& EXT4_MB_USE_ROOT_BLOCKS
) {
4532 dquot_alloc_block_nofail(ar
->inode
,
4533 EXT4_C2B(sbi
, ar
->len
));
4536 dquot_alloc_block(ar
->inode
,
4537 EXT4_C2B(sbi
, ar
->len
))) {
4539 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4550 ac
= kmem_cache_zalloc(ext4_ac_cachep
, GFP_NOFS
);
4557 *errp
= ext4_mb_initialize_context(ac
, ar
);
4563 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4564 if (!ext4_mb_use_preallocated(ac
)) {
4565 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4566 ext4_mb_normalize_request(ac
, ar
);
4568 /* allocate space in core */
4569 *errp
= ext4_mb_regular_allocator(ac
);
4571 goto discard_and_exit
;
4573 /* as we've just preallocated more space than
4574 * user requested originally, we store allocated
4575 * space in a special descriptor */
4576 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4577 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4578 *errp
= ext4_mb_new_preallocation(ac
);
4581 ext4_discard_allocated_blocks(ac
);
4585 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4586 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
, reserv_clstrs
);
4588 ext4_discard_allocated_blocks(ac
);
4591 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4592 ar
->len
= ac
->ac_b_ex
.fe_len
;
4595 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4603 ac
->ac_b_ex
.fe_len
= 0;
4605 ext4_mb_show_ac(ac
);
4607 ext4_mb_release_context(ac
);
4610 kmem_cache_free(ext4_ac_cachep
, ac
);
4611 if (inquota
&& ar
->len
< inquota
)
4612 dquot_free_block(ar
->inode
, EXT4_C2B(sbi
, inquota
- ar
->len
));
4614 if ((ar
->flags
& EXT4_MB_DELALLOC_RESERVED
) == 0)
4615 /* release all the reserved blocks if non delalloc */
4616 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
4620 trace_ext4_allocate_blocks(ar
, (unsigned long long)block
);
4626 * We can merge two free data extents only if the physical blocks
4627 * are contiguous, AND the extents were freed by the same transaction,
4628 * AND the blocks are associated with the same group.
4630 static void ext4_try_merge_freed_extent(struct ext4_sb_info
*sbi
,
4631 struct ext4_free_data
*entry
,
4632 struct ext4_free_data
*new_entry
,
4633 struct rb_root
*entry_rb_root
)
4635 if ((entry
->efd_tid
!= new_entry
->efd_tid
) ||
4636 (entry
->efd_group
!= new_entry
->efd_group
))
4638 if (entry
->efd_start_cluster
+ entry
->efd_count
==
4639 new_entry
->efd_start_cluster
) {
4640 new_entry
->efd_start_cluster
= entry
->efd_start_cluster
;
4641 new_entry
->efd_count
+= entry
->efd_count
;
4642 } else if (new_entry
->efd_start_cluster
+ new_entry
->efd_count
==
4643 entry
->efd_start_cluster
) {
4644 new_entry
->efd_count
+= entry
->efd_count
;
4647 spin_lock(&sbi
->s_md_lock
);
4648 list_del(&entry
->efd_list
);
4649 spin_unlock(&sbi
->s_md_lock
);
4650 rb_erase(&entry
->efd_node
, entry_rb_root
);
4651 kmem_cache_free(ext4_free_data_cachep
, entry
);
4654 static noinline_for_stack
int
4655 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4656 struct ext4_free_data
*new_entry
)
4658 ext4_group_t group
= e4b
->bd_group
;
4659 ext4_grpblk_t cluster
;
4660 ext4_grpblk_t clusters
= new_entry
->efd_count
;
4661 struct ext4_free_data
*entry
;
4662 struct ext4_group_info
*db
= e4b
->bd_info
;
4663 struct super_block
*sb
= e4b
->bd_sb
;
4664 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4665 struct rb_node
**n
= &db
->bb_free_root
.rb_node
, *node
;
4666 struct rb_node
*parent
= NULL
, *new_node
;
4668 BUG_ON(!ext4_handle_valid(handle
));
4669 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4670 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4672 new_node
= &new_entry
->efd_node
;
4673 cluster
= new_entry
->efd_start_cluster
;
4676 /* first free block exent. We need to
4677 protect buddy cache from being freed,
4678 * otherwise we'll refresh it from
4679 * on-disk bitmap and lose not-yet-available
4681 get_page(e4b
->bd_buddy_page
);
4682 get_page(e4b
->bd_bitmap_page
);
4686 entry
= rb_entry(parent
, struct ext4_free_data
, efd_node
);
4687 if (cluster
< entry
->efd_start_cluster
)
4689 else if (cluster
>= (entry
->efd_start_cluster
+ entry
->efd_count
))
4690 n
= &(*n
)->rb_right
;
4692 ext4_grp_locked_error(sb
, group
, 0,
4693 ext4_group_first_block_no(sb
, group
) +
4694 EXT4_C2B(sbi
, cluster
),
4695 "Block already on to-be-freed list");
4700 rb_link_node(new_node
, parent
, n
);
4701 rb_insert_color(new_node
, &db
->bb_free_root
);
4703 /* Now try to see the extent can be merged to left and right */
4704 node
= rb_prev(new_node
);
4706 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4707 ext4_try_merge_freed_extent(sbi
, entry
, new_entry
,
4708 &(db
->bb_free_root
));
4711 node
= rb_next(new_node
);
4713 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4714 ext4_try_merge_freed_extent(sbi
, entry
, new_entry
,
4715 &(db
->bb_free_root
));
4718 spin_lock(&sbi
->s_md_lock
);
4719 list_add_tail(&new_entry
->efd_list
, &sbi
->s_freed_data_list
);
4720 sbi
->s_mb_free_pending
+= clusters
;
4721 spin_unlock(&sbi
->s_md_lock
);
4726 * ext4_free_blocks() -- Free given blocks and update quota
4727 * @handle: handle for this transaction
4729 * @block: start physical block to free
4730 * @count: number of blocks to count
4731 * @flags: flags used by ext4_free_blocks
4733 void ext4_free_blocks(handle_t
*handle
, struct inode
*inode
,
4734 struct buffer_head
*bh
, ext4_fsblk_t block
,
4735 unsigned long count
, int flags
)
4737 struct buffer_head
*bitmap_bh
= NULL
;
4738 struct super_block
*sb
= inode
->i_sb
;
4739 struct ext4_group_desc
*gdp
;
4740 unsigned int overflow
;
4742 struct buffer_head
*gd_bh
;
4743 ext4_group_t block_group
;
4744 struct ext4_sb_info
*sbi
;
4745 struct ext4_buddy e4b
;
4746 unsigned int count_clusters
;
4753 BUG_ON(block
!= bh
->b_blocknr
);
4755 block
= bh
->b_blocknr
;
4759 if (!(flags
& EXT4_FREE_BLOCKS_VALIDATED
) &&
4760 !ext4_data_block_valid(sbi
, block
, count
)) {
4761 ext4_error(sb
, "Freeing blocks not in datazone - "
4762 "block = %llu, count = %lu", block
, count
);
4766 ext4_debug("freeing block %llu\n", block
);
4767 trace_ext4_free_blocks(inode
, block
, count
, flags
);
4769 if (bh
&& (flags
& EXT4_FREE_BLOCKS_FORGET
)) {
4772 ext4_forget(handle
, flags
& EXT4_FREE_BLOCKS_METADATA
,
4777 * If the extent to be freed does not begin on a cluster
4778 * boundary, we need to deal with partial clusters at the
4779 * beginning and end of the extent. Normally we will free
4780 * blocks at the beginning or the end unless we are explicitly
4781 * requested to avoid doing so.
4783 overflow
= EXT4_PBLK_COFF(sbi
, block
);
4785 if (flags
& EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER
) {
4786 overflow
= sbi
->s_cluster_ratio
- overflow
;
4788 if (count
> overflow
)
4797 overflow
= EXT4_LBLK_COFF(sbi
, count
);
4799 if (flags
& EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER
) {
4800 if (count
> overflow
)
4805 count
+= sbi
->s_cluster_ratio
- overflow
;
4808 if (!bh
&& (flags
& EXT4_FREE_BLOCKS_FORGET
)) {
4810 int is_metadata
= flags
& EXT4_FREE_BLOCKS_METADATA
;
4812 for (i
= 0; i
< count
; i
++) {
4815 bh
= sb_find_get_block(inode
->i_sb
, block
+ i
);
4816 ext4_forget(handle
, is_metadata
, inode
, bh
, block
+ i
);
4822 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4824 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
4825 ext4_get_group_info(sb
, block_group
))))
4829 * Check to see if we are freeing blocks across a group
4832 if (EXT4_C2B(sbi
, bit
) + count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4833 overflow
= EXT4_C2B(sbi
, bit
) + count
-
4834 EXT4_BLOCKS_PER_GROUP(sb
);
4837 count_clusters
= EXT4_NUM_B2C(sbi
, count
);
4838 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4839 if (IS_ERR(bitmap_bh
)) {
4840 err
= PTR_ERR(bitmap_bh
);
4844 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4850 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4851 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4852 in_range(block
, ext4_inode_table(sb
, gdp
),
4853 EXT4_SB(sb
)->s_itb_per_group
) ||
4854 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4855 EXT4_SB(sb
)->s_itb_per_group
)) {
4857 ext4_error(sb
, "Freeing blocks in system zone - "
4858 "Block = %llu, count = %lu", block
, count
);
4859 /* err = 0. ext4_std_error should be a no op */
4863 BUFFER_TRACE(bitmap_bh
, "getting write access");
4864 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4869 * We are about to modify some metadata. Call the journal APIs
4870 * to unshare ->b_data if a currently-committing transaction is
4873 BUFFER_TRACE(gd_bh
, "get_write_access");
4874 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4877 #ifdef AGGRESSIVE_CHECK
4880 for (i
= 0; i
< count_clusters
; i
++)
4881 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4884 trace_ext4_mballoc_free(sb
, inode
, block_group
, bit
, count_clusters
);
4886 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
4887 err
= ext4_mb_load_buddy_gfp(sb
, block_group
, &e4b
,
4888 GFP_NOFS
|__GFP_NOFAIL
);
4893 * We need to make sure we don't reuse the freed block until after the
4894 * transaction is committed. We make an exception if the inode is to be
4895 * written in writeback mode since writeback mode has weak data
4896 * consistency guarantees.
4898 if (ext4_handle_valid(handle
) &&
4899 ((flags
& EXT4_FREE_BLOCKS_METADATA
) ||
4900 !ext4_should_writeback_data(inode
))) {
4901 struct ext4_free_data
*new_entry
;
4903 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
4906 new_entry
= kmem_cache_alloc(ext4_free_data_cachep
,
4907 GFP_NOFS
|__GFP_NOFAIL
);
4908 new_entry
->efd_start_cluster
= bit
;
4909 new_entry
->efd_group
= block_group
;
4910 new_entry
->efd_count
= count_clusters
;
4911 new_entry
->efd_tid
= handle
->h_transaction
->t_tid
;
4913 ext4_lock_group(sb
, block_group
);
4914 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4915 ext4_mb_free_metadata(handle
, &e4b
, new_entry
);
4917 /* need to update group_info->bb_free and bitmap
4918 * with group lock held. generate_buddy look at
4919 * them with group lock_held
4921 if (test_opt(sb
, DISCARD
)) {
4922 err
= ext4_issue_discard(sb
, block_group
, bit
, count
,
4924 if (err
&& err
!= -EOPNOTSUPP
)
4925 ext4_msg(sb
, KERN_WARNING
, "discard request in"
4926 " group:%d block:%d count:%lu failed"
4927 " with %d", block_group
, bit
, count
,
4930 EXT4_MB_GRP_CLEAR_TRIMMED(e4b
.bd_info
);
4932 ext4_lock_group(sb
, block_group
);
4933 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4934 mb_free_blocks(inode
, &e4b
, bit
, count_clusters
);
4937 ret
= ext4_free_group_clusters(sb
, gdp
) + count_clusters
;
4938 ext4_free_group_clusters_set(sb
, gdp
, ret
);
4939 ext4_block_bitmap_csum_set(sb
, block_group
, gdp
, bitmap_bh
);
4940 ext4_group_desc_csum_set(sb
, block_group
, gdp
);
4941 ext4_unlock_group(sb
, block_group
);
4943 if (sbi
->s_log_groups_per_flex
) {
4944 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4945 atomic64_add(count_clusters
,
4946 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4949 if (!(flags
& EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
))
4950 dquot_free_block(inode
, EXT4_C2B(sbi
, count_clusters
));
4951 percpu_counter_add(&sbi
->s_freeclusters_counter
, count_clusters
);
4953 ext4_mb_unload_buddy(&e4b
);
4955 /* We dirtied the bitmap block */
4956 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4957 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4959 /* And the group descriptor block */
4960 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4961 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4965 if (overflow
&& !err
) {
4973 ext4_std_error(sb
, err
);
4978 * ext4_group_add_blocks() -- Add given blocks to an existing group
4979 * @handle: handle to this transaction
4981 * @block: start physical block to add to the block group
4982 * @count: number of blocks to free
4984 * This marks the blocks as free in the bitmap and buddy.
4986 int ext4_group_add_blocks(handle_t
*handle
, struct super_block
*sb
,
4987 ext4_fsblk_t block
, unsigned long count
)
4989 struct buffer_head
*bitmap_bh
= NULL
;
4990 struct buffer_head
*gd_bh
;
4991 ext4_group_t block_group
;
4994 struct ext4_group_desc
*desc
;
4995 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4996 struct ext4_buddy e4b
;
4997 int err
= 0, ret
, blk_free_count
;
4998 ext4_grpblk_t blocks_freed
;
5000 ext4_debug("Adding block(s) %llu-%llu\n", block
, block
+ count
- 1);
5005 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
5007 * Check to see if we are freeing blocks across a group
5010 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
5011 ext4_warning(sb
, "too much blocks added to group %u",
5017 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
5018 if (IS_ERR(bitmap_bh
)) {
5019 err
= PTR_ERR(bitmap_bh
);
5024 desc
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
5030 if (in_range(ext4_block_bitmap(sb
, desc
), block
, count
) ||
5031 in_range(ext4_inode_bitmap(sb
, desc
), block
, count
) ||
5032 in_range(block
, ext4_inode_table(sb
, desc
), sbi
->s_itb_per_group
) ||
5033 in_range(block
+ count
- 1, ext4_inode_table(sb
, desc
),
5034 sbi
->s_itb_per_group
)) {
5035 ext4_error(sb
, "Adding blocks in system zones - "
5036 "Block = %llu, count = %lu",
5042 BUFFER_TRACE(bitmap_bh
, "getting write access");
5043 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
5048 * We are about to modify some metadata. Call the journal APIs
5049 * to unshare ->b_data if a currently-committing transaction is
5052 BUFFER_TRACE(gd_bh
, "get_write_access");
5053 err
= ext4_journal_get_write_access(handle
, gd_bh
);
5057 for (i
= 0, blocks_freed
= 0; i
< count
; i
++) {
5058 BUFFER_TRACE(bitmap_bh
, "clear bit");
5059 if (!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
)) {
5060 ext4_error(sb
, "bit already cleared for block %llu",
5061 (ext4_fsblk_t
)(block
+ i
));
5062 BUFFER_TRACE(bitmap_bh
, "bit already cleared");
5068 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
5073 * need to update group_info->bb_free and bitmap
5074 * with group lock held. generate_buddy look at
5075 * them with group lock_held
5077 ext4_lock_group(sb
, block_group
);
5078 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
5079 mb_free_blocks(NULL
, &e4b
, bit
, count
);
5080 blk_free_count
= blocks_freed
+ ext4_free_group_clusters(sb
, desc
);
5081 ext4_free_group_clusters_set(sb
, desc
, blk_free_count
);
5082 ext4_block_bitmap_csum_set(sb
, block_group
, desc
, bitmap_bh
);
5083 ext4_group_desc_csum_set(sb
, block_group
, desc
);
5084 ext4_unlock_group(sb
, block_group
);
5085 percpu_counter_add(&sbi
->s_freeclusters_counter
,
5086 EXT4_NUM_B2C(sbi
, blocks_freed
));
5088 if (sbi
->s_log_groups_per_flex
) {
5089 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
5090 atomic64_add(EXT4_NUM_B2C(sbi
, blocks_freed
),
5091 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
5094 ext4_mb_unload_buddy(&e4b
);
5096 /* We dirtied the bitmap block */
5097 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
5098 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
5100 /* And the group descriptor block */
5101 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
5102 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
5108 ext4_std_error(sb
, err
);
5113 * ext4_trim_extent -- function to TRIM one single free extent in the group
5114 * @sb: super block for the file system
5115 * @start: starting block of the free extent in the alloc. group
5116 * @count: number of blocks to TRIM
5117 * @group: alloc. group we are working with
5118 * @e4b: ext4 buddy for the group
5120 * Trim "count" blocks starting at "start" in the "group". To assure that no
5121 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5122 * be called with under the group lock.
5124 static int ext4_trim_extent(struct super_block
*sb
, int start
, int count
,
5125 ext4_group_t group
, struct ext4_buddy
*e4b
)
5129 struct ext4_free_extent ex
;
5132 trace_ext4_trim_extent(sb
, group
, start
, count
);
5134 assert_spin_locked(ext4_group_lock_ptr(sb
, group
));
5136 ex
.fe_start
= start
;
5137 ex
.fe_group
= group
;
5141 * Mark blocks used, so no one can reuse them while
5144 mb_mark_used(e4b
, &ex
);
5145 ext4_unlock_group(sb
, group
);
5146 ret
= ext4_issue_discard(sb
, group
, start
, count
, NULL
);
5147 ext4_lock_group(sb
, group
);
5148 mb_free_blocks(NULL
, e4b
, start
, ex
.fe_len
);
5153 * ext4_trim_all_free -- function to trim all free space in alloc. group
5154 * @sb: super block for file system
5155 * @group: group to be trimmed
5156 * @start: first group block to examine
5157 * @max: last group block to examine
5158 * @minblocks: minimum extent block count
5160 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5161 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5165 * ext4_trim_all_free walks through group's block bitmap searching for free
5166 * extents. When the free extent is found, mark it as used in group buddy
5167 * bitmap. Then issue a TRIM command on this extent and free the extent in
5168 * the group buddy bitmap. This is done until whole group is scanned.
5170 static ext4_grpblk_t
5171 ext4_trim_all_free(struct super_block
*sb
, ext4_group_t group
,
5172 ext4_grpblk_t start
, ext4_grpblk_t max
,
5173 ext4_grpblk_t minblocks
)
5176 ext4_grpblk_t next
, count
= 0, free_count
= 0;
5177 struct ext4_buddy e4b
;
5180 trace_ext4_trim_all_free(sb
, group
, start
, max
);
5182 ret
= ext4_mb_load_buddy(sb
, group
, &e4b
);
5184 ext4_warning(sb
, "Error %d loading buddy information for %u",
5188 bitmap
= e4b
.bd_bitmap
;
5190 ext4_lock_group(sb
, group
);
5191 if (EXT4_MB_GRP_WAS_TRIMMED(e4b
.bd_info
) &&
5192 minblocks
>= atomic_read(&EXT4_SB(sb
)->s_last_trim_minblks
))
5195 start
= (e4b
.bd_info
->bb_first_free
> start
) ?
5196 e4b
.bd_info
->bb_first_free
: start
;
5198 while (start
<= max
) {
5199 start
= mb_find_next_zero_bit(bitmap
, max
+ 1, start
);
5202 next
= mb_find_next_bit(bitmap
, max
+ 1, start
);
5204 if ((next
- start
) >= minblocks
) {
5205 ret
= ext4_trim_extent(sb
, start
,
5206 next
- start
, group
, &e4b
);
5207 if (ret
&& ret
!= -EOPNOTSUPP
)
5210 count
+= next
- start
;
5212 free_count
+= next
- start
;
5215 if (fatal_signal_pending(current
)) {
5216 count
= -ERESTARTSYS
;
5220 if (need_resched()) {
5221 ext4_unlock_group(sb
, group
);
5223 ext4_lock_group(sb
, group
);
5226 if ((e4b
.bd_info
->bb_free
- free_count
) < minblocks
)
5232 EXT4_MB_GRP_SET_TRIMMED(e4b
.bd_info
);
5235 ext4_unlock_group(sb
, group
);
5236 ext4_mb_unload_buddy(&e4b
);
5238 ext4_debug("trimmed %d blocks in the group %d\n",
5245 * ext4_trim_fs() -- trim ioctl handle function
5246 * @sb: superblock for filesystem
5247 * @range: fstrim_range structure
5249 * start: First Byte to trim
5250 * len: number of Bytes to trim from start
5251 * minlen: minimum extent length in Bytes
5252 * ext4_trim_fs goes through all allocation groups containing Bytes from
5253 * start to start+len. For each such a group ext4_trim_all_free function
5254 * is invoked to trim all free space.
5256 int ext4_trim_fs(struct super_block
*sb
, struct fstrim_range
*range
)
5258 struct ext4_group_info
*grp
;
5259 ext4_group_t group
, first_group
, last_group
;
5260 ext4_grpblk_t cnt
= 0, first_cluster
, last_cluster
;
5261 uint64_t start
, end
, minlen
, trimmed
= 0;
5262 ext4_fsblk_t first_data_blk
=
5263 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
5264 ext4_fsblk_t max_blks
= ext4_blocks_count(EXT4_SB(sb
)->s_es
);
5267 start
= range
->start
>> sb
->s_blocksize_bits
;
5268 end
= start
+ (range
->len
>> sb
->s_blocksize_bits
) - 1;
5269 minlen
= EXT4_NUM_B2C(EXT4_SB(sb
),
5270 range
->minlen
>> sb
->s_blocksize_bits
);
5272 if (minlen
> EXT4_CLUSTERS_PER_GROUP(sb
) ||
5273 start
>= max_blks
||
5274 range
->len
< sb
->s_blocksize
)
5276 if (end
>= max_blks
)
5278 if (end
<= first_data_blk
)
5280 if (start
< first_data_blk
)
5281 start
= first_data_blk
;
5283 /* Determine first and last group to examine based on start and end */
5284 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) start
,
5285 &first_group
, &first_cluster
);
5286 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) end
,
5287 &last_group
, &last_cluster
);
5289 /* end now represents the last cluster to discard in this group */
5290 end
= EXT4_CLUSTERS_PER_GROUP(sb
) - 1;
5292 for (group
= first_group
; group
<= last_group
; group
++) {
5293 grp
= ext4_get_group_info(sb
, group
);
5294 /* We only do this if the grp has never been initialized */
5295 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
5296 ret
= ext4_mb_init_group(sb
, group
, GFP_NOFS
);
5302 * For all the groups except the last one, last cluster will
5303 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5304 * change it for the last group, note that last_cluster is
5305 * already computed earlier by ext4_get_group_no_and_offset()
5307 if (group
== last_group
)
5310 if (grp
->bb_free
>= minlen
) {
5311 cnt
= ext4_trim_all_free(sb
, group
, first_cluster
,
5321 * For every group except the first one, we are sure
5322 * that the first cluster to discard will be cluster #0.
5328 atomic_set(&EXT4_SB(sb
)->s_last_trim_minblks
, minlen
);
5331 range
->len
= EXT4_C2B(EXT4_SB(sb
), trimmed
) << sb
->s_blocksize_bits
;
5335 /* Iterate all the free extents in the group. */
5337 ext4_mballoc_query_range(
5338 struct super_block
*sb
,
5340 ext4_grpblk_t start
,
5342 ext4_mballoc_query_range_fn formatter
,
5347 struct ext4_buddy e4b
;
5350 error
= ext4_mb_load_buddy(sb
, group
, &e4b
);
5353 bitmap
= e4b
.bd_bitmap
;
5355 ext4_lock_group(sb
, group
);
5357 start
= (e4b
.bd_info
->bb_first_free
> start
) ?
5358 e4b
.bd_info
->bb_first_free
: start
;
5359 if (end
>= EXT4_CLUSTERS_PER_GROUP(sb
))
5360 end
= EXT4_CLUSTERS_PER_GROUP(sb
) - 1;
5362 while (start
<= end
) {
5363 start
= mb_find_next_zero_bit(bitmap
, end
+ 1, start
);
5366 next
= mb_find_next_bit(bitmap
, end
+ 1, start
);
5368 ext4_unlock_group(sb
, group
);
5369 error
= formatter(sb
, group
, start
, next
- start
, priv
);
5372 ext4_lock_group(sb
, group
);
5377 ext4_unlock_group(sb
, group
);
5379 ext4_mb_unload_buddy(&e4b
);