2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public Licens
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 * mballoc.c contains the multiblocks allocation routines
24 #include "ext4_jbd2.h"
26 #include <linux/log2.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <trace/events/ext4.h>
31 #ifdef CONFIG_EXT4_DEBUG
32 ushort ext4_mballoc_debug __read_mostly
;
34 module_param_named(mballoc_debug
, ext4_mballoc_debug
, ushort
, 0644);
35 MODULE_PARM_DESC(mballoc_debug
, "Debugging level for ext4's mballoc");
40 * - test ext4_ext_search_left() and ext4_ext_search_right()
41 * - search for metadata in few groups
44 * - normalization should take into account whether file is still open
45 * - discard preallocations if no free space left (policy?)
46 * - don't normalize tails
48 * - reservation for superuser
51 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
52 * - track min/max extents in each group for better group selection
53 * - mb_mark_used() may allocate chunk right after splitting buddy
54 * - tree of groups sorted by number of free blocks
59 * The allocation request involve request for multiple number of blocks
60 * near to the goal(block) value specified.
62 * During initialization phase of the allocator we decide to use the
63 * group preallocation or inode preallocation depending on the size of
64 * the file. The size of the file could be the resulting file size we
65 * would have after allocation, or the current file size, which ever
66 * is larger. If the size is less than sbi->s_mb_stream_request we
67 * select to use the group preallocation. The default value of
68 * s_mb_stream_request is 16 blocks. This can also be tuned via
69 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
70 * terms of number of blocks.
72 * The main motivation for having small file use group preallocation is to
73 * ensure that we have small files closer together on the disk.
75 * First stage the allocator looks at the inode prealloc list,
76 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
77 * spaces for this particular inode. The inode prealloc space is
80 * pa_lstart -> the logical start block for this prealloc space
81 * pa_pstart -> the physical start block for this prealloc space
82 * pa_len -> length for this prealloc space (in clusters)
83 * pa_free -> free space available in this prealloc space (in clusters)
85 * The inode preallocation space is used looking at the _logical_ start
86 * block. If only the logical file block falls within the range of prealloc
87 * space we will consume the particular prealloc space. This makes sure that
88 * we have contiguous physical blocks representing the file blocks
90 * The important thing to be noted in case of inode prealloc space is that
91 * we don't modify the values associated to inode prealloc space except
94 * If we are not able to find blocks in the inode prealloc space and if we
95 * have the group allocation flag set then we look at the locality group
96 * prealloc space. These are per CPU prealloc list represented as
98 * ext4_sb_info.s_locality_groups[smp_processor_id()]
100 * The reason for having a per cpu locality group is to reduce the contention
101 * between CPUs. It is possible to get scheduled at this point.
103 * The locality group prealloc space is used looking at whether we have
104 * enough free space (pa_free) within the prealloc space.
106 * If we can't allocate blocks via inode prealloc or/and locality group
107 * prealloc then we look at the buddy cache. The buddy cache is represented
108 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
109 * mapped to the buddy and bitmap information regarding different
110 * groups. The buddy information is attached to buddy cache inode so that
111 * we can access them through the page cache. The information regarding
112 * each group is loaded via ext4_mb_load_buddy. The information involve
113 * block bitmap and buddy information. The information are stored in the
117 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
120 * one block each for bitmap and buddy information. So for each group we
121 * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
122 * blocksize) blocks. So it can have information regarding groups_per_page
123 * which is blocks_per_page/2
125 * The buddy cache inode is not stored on disk. The inode is thrown
126 * away when the filesystem is unmounted.
128 * We look for count number of blocks in the buddy cache. If we were able
129 * to locate that many free blocks we return with additional information
130 * regarding rest of the contiguous physical block available
132 * Before allocating blocks via buddy cache we normalize the request
133 * blocks. This ensure we ask for more blocks that we needed. The extra
134 * blocks that we get after allocation is added to the respective prealloc
135 * list. In case of inode preallocation we follow a list of heuristics
136 * based on file size. This can be found in ext4_mb_normalize_request. If
137 * we are doing a group prealloc we try to normalize the request to
138 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
139 * dependent on the cluster size; for non-bigalloc file systems, it is
140 * 512 blocks. This can be tuned via
141 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
142 * terms of number of blocks. If we have mounted the file system with -O
143 * stripe=<value> option the group prealloc request is normalized to the
144 * the smallest multiple of the stripe value (sbi->s_stripe) which is
145 * greater than the default mb_group_prealloc.
147 * The regular allocator (using the buddy cache) supports a few tunables.
149 * /sys/fs/ext4/<partition>/mb_min_to_scan
150 * /sys/fs/ext4/<partition>/mb_max_to_scan
151 * /sys/fs/ext4/<partition>/mb_order2_req
153 * The regular allocator uses buddy scan only if the request len is power of
154 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
155 * value of s_mb_order2_reqs can be tuned via
156 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
157 * stripe size (sbi->s_stripe), we try to search for contiguous block in
158 * stripe size. This should result in better allocation on RAID setups. If
159 * not, we search in the specific group using bitmap for best extents. The
160 * tunable min_to_scan and max_to_scan control the behaviour here.
161 * min_to_scan indicate how long the mballoc __must__ look for a best
162 * extent and max_to_scan indicates how long the mballoc __can__ look for a
163 * best extent in the found extents. Searching for the blocks starts with
164 * the group specified as the goal value in allocation context via
165 * ac_g_ex. Each group is first checked based on the criteria whether it
166 * can be used for allocation. ext4_mb_good_group explains how the groups are
169 * Both the prealloc space are getting populated as above. So for the first
170 * request we will hit the buddy cache which will result in this prealloc
171 * space getting filled. The prealloc space is then later used for the
172 * subsequent request.
176 * mballoc operates on the following data:
178 * - in-core buddy (actually includes buddy and bitmap)
179 * - preallocation descriptors (PAs)
181 * there are two types of preallocations:
183 * assiged to specific inode and can be used for this inode only.
184 * it describes part of inode's space preallocated to specific
185 * physical blocks. any block from that preallocated can be used
186 * independent. the descriptor just tracks number of blocks left
187 * unused. so, before taking some block from descriptor, one must
188 * make sure corresponded logical block isn't allocated yet. this
189 * also means that freeing any block within descriptor's range
190 * must discard all preallocated blocks.
192 * assigned to specific locality group which does not translate to
193 * permanent set of inodes: inode can join and leave group. space
194 * from this type of preallocation can be used for any inode. thus
195 * it's consumed from the beginning to the end.
197 * relation between them can be expressed as:
198 * in-core buddy = on-disk bitmap + preallocation descriptors
200 * this mean blocks mballoc considers used are:
201 * - allocated blocks (persistent)
202 * - preallocated blocks (non-persistent)
204 * consistency in mballoc world means that at any time a block is either
205 * free or used in ALL structures. notice: "any time" should not be read
206 * literally -- time is discrete and delimited by locks.
208 * to keep it simple, we don't use block numbers, instead we count number of
209 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
211 * all operations can be expressed as:
212 * - init buddy: buddy = on-disk + PAs
213 * - new PA: buddy += N; PA = N
214 * - use inode PA: on-disk += N; PA -= N
215 * - discard inode PA buddy -= on-disk - PA; PA = 0
216 * - use locality group PA on-disk += N; PA -= N
217 * - discard locality group PA buddy -= PA; PA = 0
218 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
219 * is used in real operation because we can't know actual used
220 * bits from PA, only from on-disk bitmap
222 * if we follow this strict logic, then all operations above should be atomic.
223 * given some of them can block, we'd have to use something like semaphores
224 * killing performance on high-end SMP hardware. let's try to relax it using
225 * the following knowledge:
226 * 1) if buddy is referenced, it's already initialized
227 * 2) while block is used in buddy and the buddy is referenced,
228 * nobody can re-allocate that block
229 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
230 * bit set and PA claims same block, it's OK. IOW, one can set bit in
231 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
234 * so, now we're building a concurrency table:
237 * blocks for PA are allocated in the buddy, buddy must be referenced
238 * until PA is linked to allocation group to avoid concurrent buddy init
240 * we need to make sure that either on-disk bitmap or PA has uptodate data
241 * given (3) we care that PA-=N operation doesn't interfere with init
243 * the simplest way would be to have buddy initialized by the discard
244 * - use locality group PA
245 * again PA-=N must be serialized with init
246 * - discard locality group PA
247 * the simplest way would be to have buddy initialized by the discard
250 * i_data_sem serializes them
252 * discard process must wait until PA isn't used by another process
253 * - use locality group PA
254 * some mutex should serialize them
255 * - discard locality group PA
256 * discard process must wait until PA isn't used by another process
259 * i_data_sem or another mutex should serializes them
261 * discard process must wait until PA isn't used by another process
262 * - use locality group PA
263 * nothing wrong here -- they're different PAs covering different blocks
264 * - discard locality group PA
265 * discard process must wait until PA isn't used by another process
267 * now we're ready to make few consequences:
268 * - PA is referenced and while it is no discard is possible
269 * - PA is referenced until block isn't marked in on-disk bitmap
270 * - PA changes only after on-disk bitmap
271 * - discard must not compete with init. either init is done before
272 * any discard or they're serialized somehow
273 * - buddy init as sum of on-disk bitmap and PAs is done atomically
275 * a special case when we've used PA to emptiness. no need to modify buddy
276 * in this case, but we should care about concurrent init
281 * Logic in few words:
286 * mark bits in on-disk bitmap
289 * - use preallocation:
290 * find proper PA (per-inode or group)
292 * mark bits in on-disk bitmap
298 * mark bits in on-disk bitmap
301 * - discard preallocations in group:
303 * move them onto local list
304 * load on-disk bitmap
306 * remove PA from object (inode or locality group)
307 * mark free blocks in-core
309 * - discard inode's preallocations:
316 * - bitlock on a group (group)
317 * - object (inode/locality) (object)
328 * - release consumed pa:
333 * - generate in-core bitmap:
337 * - discard all for given object (inode, locality group):
342 * - discard all for given group:
349 static struct kmem_cache
*ext4_pspace_cachep
;
350 static struct kmem_cache
*ext4_ac_cachep
;
351 static struct kmem_cache
*ext4_free_data_cachep
;
353 /* We create slab caches for groupinfo data structures based on the
354 * superblock block size. There will be one per mounted filesystem for
355 * each unique s_blocksize_bits */
356 #define NR_GRPINFO_CACHES 8
357 static struct kmem_cache
*ext4_groupinfo_caches
[NR_GRPINFO_CACHES
];
359 static const char *ext4_groupinfo_slab_names
[NR_GRPINFO_CACHES
] = {
360 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
361 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
362 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
365 static void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
367 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
369 static void ext4_free_data_callback(struct super_block
*sb
,
370 struct ext4_journal_cb_entry
*jce
, int rc
);
372 static inline void *mb_correct_addr_and_bit(int *bit
, void *addr
)
374 #if BITS_PER_LONG == 64
375 *bit
+= ((unsigned long) addr
& 7UL) << 3;
376 addr
= (void *) ((unsigned long) addr
& ~7UL);
377 #elif BITS_PER_LONG == 32
378 *bit
+= ((unsigned long) addr
& 3UL) << 3;
379 addr
= (void *) ((unsigned long) addr
& ~3UL);
381 #error "how many bits you are?!"
386 static inline int mb_test_bit(int bit
, void *addr
)
389 * ext4_test_bit on architecture like powerpc
390 * needs unsigned long aligned address
392 addr
= mb_correct_addr_and_bit(&bit
, addr
);
393 return ext4_test_bit(bit
, addr
);
396 static inline void mb_set_bit(int bit
, void *addr
)
398 addr
= mb_correct_addr_and_bit(&bit
, addr
);
399 ext4_set_bit(bit
, addr
);
402 static inline void mb_clear_bit(int bit
, void *addr
)
404 addr
= mb_correct_addr_and_bit(&bit
, addr
);
405 ext4_clear_bit(bit
, addr
);
408 static inline int mb_test_and_clear_bit(int bit
, void *addr
)
410 addr
= mb_correct_addr_and_bit(&bit
, addr
);
411 return ext4_test_and_clear_bit(bit
, addr
);
414 static inline int mb_find_next_zero_bit(void *addr
, int max
, int start
)
416 int fix
= 0, ret
, tmpmax
;
417 addr
= mb_correct_addr_and_bit(&fix
, addr
);
421 ret
= ext4_find_next_zero_bit(addr
, tmpmax
, start
) - fix
;
427 static inline int mb_find_next_bit(void *addr
, int max
, int start
)
429 int fix
= 0, ret
, tmpmax
;
430 addr
= mb_correct_addr_and_bit(&fix
, addr
);
434 ret
= ext4_find_next_bit(addr
, tmpmax
, start
) - fix
;
440 static void *mb_find_buddy(struct ext4_buddy
*e4b
, int order
, int *max
)
444 BUG_ON(e4b
->bd_bitmap
== e4b
->bd_buddy
);
447 if (order
> e4b
->bd_blkbits
+ 1) {
452 /* at order 0 we see each particular block */
454 *max
= 1 << (e4b
->bd_blkbits
+ 3);
455 return e4b
->bd_bitmap
;
458 bb
= e4b
->bd_buddy
+ EXT4_SB(e4b
->bd_sb
)->s_mb_offsets
[order
];
459 *max
= EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[order
];
465 static void mb_free_blocks_double(struct inode
*inode
, struct ext4_buddy
*e4b
,
466 int first
, int count
)
469 struct super_block
*sb
= e4b
->bd_sb
;
471 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
473 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
474 for (i
= 0; i
< count
; i
++) {
475 if (!mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
)) {
476 ext4_fsblk_t blocknr
;
478 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
479 blocknr
+= EXT4_C2B(EXT4_SB(sb
), first
+ i
);
480 ext4_grp_locked_error(sb
, e4b
->bd_group
,
481 inode
? inode
->i_ino
: 0,
483 "freeing block already freed "
487 mb_clear_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
491 static void mb_mark_used_double(struct ext4_buddy
*e4b
, int first
, int count
)
495 if (unlikely(e4b
->bd_info
->bb_bitmap
== NULL
))
497 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
498 for (i
= 0; i
< count
; i
++) {
499 BUG_ON(mb_test_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
));
500 mb_set_bit(first
+ i
, e4b
->bd_info
->bb_bitmap
);
504 static void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
506 if (memcmp(e4b
->bd_info
->bb_bitmap
, bitmap
, e4b
->bd_sb
->s_blocksize
)) {
507 unsigned char *b1
, *b2
;
509 b1
= (unsigned char *) e4b
->bd_info
->bb_bitmap
;
510 b2
= (unsigned char *) bitmap
;
511 for (i
= 0; i
< e4b
->bd_sb
->s_blocksize
; i
++) {
512 if (b1
[i
] != b2
[i
]) {
513 ext4_msg(e4b
->bd_sb
, KERN_ERR
,
514 "corruption in group %u "
515 "at byte %u(%u): %x in copy != %x "
517 e4b
->bd_group
, i
, i
* 8, b1
[i
], b2
[i
]);
525 static inline void mb_free_blocks_double(struct inode
*inode
,
526 struct ext4_buddy
*e4b
, int first
, int count
)
530 static inline void mb_mark_used_double(struct ext4_buddy
*e4b
,
531 int first
, int count
)
535 static inline void mb_cmp_bitmaps(struct ext4_buddy
*e4b
, void *bitmap
)
541 #ifdef AGGRESSIVE_CHECK
543 #define MB_CHECK_ASSERT(assert) \
547 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
548 function, file, line, # assert); \
553 static int __mb_check_buddy(struct ext4_buddy
*e4b
, char *file
,
554 const char *function
, int line
)
556 struct super_block
*sb
= e4b
->bd_sb
;
557 int order
= e4b
->bd_blkbits
+ 1;
564 struct ext4_group_info
*grp
;
567 struct list_head
*cur
;
572 static int mb_check_counter
;
573 if (mb_check_counter
++ % 100 != 0)
578 buddy
= mb_find_buddy(e4b
, order
, &max
);
579 MB_CHECK_ASSERT(buddy
);
580 buddy2
= mb_find_buddy(e4b
, order
- 1, &max2
);
581 MB_CHECK_ASSERT(buddy2
);
582 MB_CHECK_ASSERT(buddy
!= buddy2
);
583 MB_CHECK_ASSERT(max
* 2 == max2
);
586 for (i
= 0; i
< max
; i
++) {
588 if (mb_test_bit(i
, buddy
)) {
589 /* only single bit in buddy2 may be 1 */
590 if (!mb_test_bit(i
<< 1, buddy2
)) {
592 mb_test_bit((i
<<1)+1, buddy2
));
593 } else if (!mb_test_bit((i
<< 1) + 1, buddy2
)) {
595 mb_test_bit(i
<< 1, buddy2
));
600 /* both bits in buddy2 must be 1 */
601 MB_CHECK_ASSERT(mb_test_bit(i
<< 1, buddy2
));
602 MB_CHECK_ASSERT(mb_test_bit((i
<< 1) + 1, buddy2
));
604 for (j
= 0; j
< (1 << order
); j
++) {
605 k
= (i
* (1 << order
)) + j
;
607 !mb_test_bit(k
, e4b
->bd_bitmap
));
611 MB_CHECK_ASSERT(e4b
->bd_info
->bb_counters
[order
] == count
);
616 buddy
= mb_find_buddy(e4b
, 0, &max
);
617 for (i
= 0; i
< max
; i
++) {
618 if (!mb_test_bit(i
, buddy
)) {
619 MB_CHECK_ASSERT(i
>= e4b
->bd_info
->bb_first_free
);
627 /* check used bits only */
628 for (j
= 0; j
< e4b
->bd_blkbits
+ 1; j
++) {
629 buddy2
= mb_find_buddy(e4b
, j
, &max2
);
631 MB_CHECK_ASSERT(k
< max2
);
632 MB_CHECK_ASSERT(mb_test_bit(k
, buddy2
));
635 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b
->bd_info
));
636 MB_CHECK_ASSERT(e4b
->bd_info
->bb_fragments
== fragments
);
638 grp
= ext4_get_group_info(sb
, e4b
->bd_group
);
639 list_for_each(cur
, &grp
->bb_prealloc_list
) {
640 ext4_group_t groupnr
;
641 struct ext4_prealloc_space
*pa
;
642 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
643 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &groupnr
, &k
);
644 MB_CHECK_ASSERT(groupnr
== e4b
->bd_group
);
645 for (i
= 0; i
< pa
->pa_len
; i
++)
646 MB_CHECK_ASSERT(mb_test_bit(k
+ i
, buddy
));
650 #undef MB_CHECK_ASSERT
651 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
652 __FILE__, __func__, __LINE__)
654 #define mb_check_buddy(e4b)
658 * Divide blocks started from @first with length @len into
659 * smaller chunks with power of 2 blocks.
660 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
661 * then increase bb_counters[] for corresponded chunk size.
663 static void ext4_mb_mark_free_simple(struct super_block
*sb
,
664 void *buddy
, ext4_grpblk_t first
, ext4_grpblk_t len
,
665 struct ext4_group_info
*grp
)
667 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
671 unsigned short border
;
673 BUG_ON(len
> EXT4_CLUSTERS_PER_GROUP(sb
));
675 border
= 2 << sb
->s_blocksize_bits
;
678 /* find how many blocks can be covered since this position */
679 max
= ffs(first
| border
) - 1;
681 /* find how many blocks of power 2 we need to mark */
688 /* mark multiblock chunks only */
689 grp
->bb_counters
[min
]++;
691 mb_clear_bit(first
>> min
,
692 buddy
+ sbi
->s_mb_offsets
[min
]);
700 * Cache the order of the largest free extent we have available in this block
704 mb_set_largest_free_order(struct super_block
*sb
, struct ext4_group_info
*grp
)
709 grp
->bb_largest_free_order
= -1; /* uninit */
711 bits
= sb
->s_blocksize_bits
+ 1;
712 for (i
= bits
; i
>= 0; i
--) {
713 if (grp
->bb_counters
[i
] > 0) {
714 grp
->bb_largest_free_order
= i
;
720 static noinline_for_stack
721 void ext4_mb_generate_buddy(struct super_block
*sb
,
722 void *buddy
, void *bitmap
, ext4_group_t group
)
724 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
725 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
726 ext4_grpblk_t max
= EXT4_CLUSTERS_PER_GROUP(sb
);
731 unsigned fragments
= 0;
732 unsigned long long period
= get_cycles();
734 /* initialize buddy from bitmap which is aggregation
735 * of on-disk bitmap and preallocations */
736 i
= mb_find_next_zero_bit(bitmap
, max
, 0);
737 grp
->bb_first_free
= i
;
741 i
= mb_find_next_bit(bitmap
, max
, i
);
745 ext4_mb_mark_free_simple(sb
, buddy
, first
, len
, grp
);
747 grp
->bb_counters
[0]++;
749 i
= mb_find_next_zero_bit(bitmap
, max
, i
);
751 grp
->bb_fragments
= fragments
;
753 if (free
!= grp
->bb_free
) {
754 ext4_grp_locked_error(sb
, group
, 0, 0,
755 "block bitmap and bg descriptor "
756 "inconsistent: %u vs %u free clusters",
759 * If we intend to continue, we consider group descriptor
760 * corrupt and update bb_free using bitmap value
763 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp
))
764 percpu_counter_sub(&sbi
->s_freeclusters_counter
,
766 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT
, &grp
->bb_state
);
768 mb_set_largest_free_order(sb
, grp
);
770 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
, &(grp
->bb_state
));
772 period
= get_cycles() - period
;
773 spin_lock(&EXT4_SB(sb
)->s_bal_lock
);
774 EXT4_SB(sb
)->s_mb_buddies_generated
++;
775 EXT4_SB(sb
)->s_mb_generation_time
+= period
;
776 spin_unlock(&EXT4_SB(sb
)->s_bal_lock
);
779 static void mb_regenerate_buddy(struct ext4_buddy
*e4b
)
785 while ((buddy
= mb_find_buddy(e4b
, order
++, &count
))) {
786 ext4_set_bits(buddy
, 0, count
);
788 e4b
->bd_info
->bb_fragments
= 0;
789 memset(e4b
->bd_info
->bb_counters
, 0,
790 sizeof(*e4b
->bd_info
->bb_counters
) *
791 (e4b
->bd_sb
->s_blocksize_bits
+ 2));
793 ext4_mb_generate_buddy(e4b
->bd_sb
, e4b
->bd_buddy
,
794 e4b
->bd_bitmap
, e4b
->bd_group
);
797 /* The buddy information is attached the buddy cache inode
798 * for convenience. The information regarding each group
799 * is loaded via ext4_mb_load_buddy. The information involve
800 * block bitmap and buddy information. The information are
801 * stored in the inode as
804 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
807 * one block each for bitmap and buddy information.
808 * So for each group we take up 2 blocks. A page can
809 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
810 * So it can have information regarding groups_per_page which
811 * is blocks_per_page/2
813 * Locking note: This routine takes the block group lock of all groups
814 * for this page; do not hold this lock when calling this routine!
817 static int ext4_mb_init_cache(struct page
*page
, char *incore
)
819 ext4_group_t ngroups
;
825 ext4_group_t first_group
, group
;
827 struct super_block
*sb
;
828 struct buffer_head
*bhs
;
829 struct buffer_head
**bh
= NULL
;
833 struct ext4_group_info
*grinfo
;
835 mb_debug(1, "init page %lu\n", page
->index
);
837 inode
= page
->mapping
->host
;
839 ngroups
= ext4_get_groups_count(sb
);
840 blocksize
= 1 << inode
->i_blkbits
;
841 blocks_per_page
= PAGE_CACHE_SIZE
/ blocksize
;
843 groups_per_page
= blocks_per_page
>> 1;
844 if (groups_per_page
== 0)
847 /* allocate buffer_heads to read bitmaps */
848 if (groups_per_page
> 1) {
849 i
= sizeof(struct buffer_head
*) * groups_per_page
;
850 bh
= kzalloc(i
, GFP_NOFS
);
858 first_group
= page
->index
* blocks_per_page
/ 2;
860 /* read all groups the page covers into the cache */
861 for (i
= 0, group
= first_group
; i
< groups_per_page
; i
++, group
++) {
862 if (group
>= ngroups
)
865 grinfo
= ext4_get_group_info(sb
, group
);
867 * If page is uptodate then we came here after online resize
868 * which added some new uninitialized group info structs, so
869 * we must skip all initialized uptodate buddies on the page,
870 * which may be currently in use by an allocating task.
872 if (PageUptodate(page
) && !EXT4_MB_GRP_NEED_INIT(grinfo
)) {
876 if (!(bh
[i
] = ext4_read_block_bitmap_nowait(sb
, group
))) {
880 mb_debug(1, "read bitmap for group %u\n", group
);
883 /* wait for I/O completion */
884 for (i
= 0, group
= first_group
; i
< groups_per_page
; i
++, group
++) {
885 if (bh
[i
] && ext4_wait_block_bitmap(sb
, group
, bh
[i
]))
889 first_block
= page
->index
* blocks_per_page
;
890 for (i
= 0; i
< blocks_per_page
; i
++) {
891 group
= (first_block
+ i
) >> 1;
892 if (group
>= ngroups
)
895 if (!bh
[group
- first_group
])
896 /* skip initialized uptodate buddy */
899 if (!buffer_verified(bh
[group
- first_group
]))
900 /* Skip faulty bitmaps */
905 * data carry information regarding this
906 * particular group in the format specified
910 data
= page_address(page
) + (i
* blocksize
);
911 bitmap
= bh
[group
- first_group
]->b_data
;
914 * We place the buddy block and bitmap block
917 if ((first_block
+ i
) & 1) {
918 /* this is block of buddy */
919 BUG_ON(incore
== NULL
);
920 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
921 group
, page
->index
, i
* blocksize
);
922 trace_ext4_mb_buddy_bitmap_load(sb
, group
);
923 grinfo
= ext4_get_group_info(sb
, group
);
924 grinfo
->bb_fragments
= 0;
925 memset(grinfo
->bb_counters
, 0,
926 sizeof(*grinfo
->bb_counters
) *
927 (sb
->s_blocksize_bits
+2));
929 * incore got set to the group block bitmap below
931 ext4_lock_group(sb
, group
);
933 memset(data
, 0xff, blocksize
);
934 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
935 ext4_unlock_group(sb
, group
);
938 /* this is block of bitmap */
939 BUG_ON(incore
!= NULL
);
940 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
941 group
, page
->index
, i
* blocksize
);
942 trace_ext4_mb_bitmap_load(sb
, group
);
944 /* see comments in ext4_mb_put_pa() */
945 ext4_lock_group(sb
, group
);
946 memcpy(data
, bitmap
, blocksize
);
948 /* mark all preallocated blks used in in-core bitmap */
949 ext4_mb_generate_from_pa(sb
, data
, group
);
950 ext4_mb_generate_from_freelist(sb
, data
, group
);
951 ext4_unlock_group(sb
, group
);
953 /* set incore so that the buddy information can be
954 * generated using this
959 SetPageUptodate(page
);
963 for (i
= 0; i
< groups_per_page
; i
++)
972 * Lock the buddy and bitmap pages. This make sure other parallel init_group
973 * on the same buddy page doesn't happen whild holding the buddy page lock.
974 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
975 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
977 static int ext4_mb_get_buddy_page_lock(struct super_block
*sb
,
978 ext4_group_t group
, struct ext4_buddy
*e4b
)
980 struct inode
*inode
= EXT4_SB(sb
)->s_buddy_cache
;
981 int block
, pnum
, poff
;
985 e4b
->bd_buddy_page
= NULL
;
986 e4b
->bd_bitmap_page
= NULL
;
988 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
990 * the buddy cache inode stores the block bitmap
991 * and buddy information in consecutive blocks.
992 * So for each group we need two blocks.
995 pnum
= block
/ blocks_per_page
;
996 poff
= block
% blocks_per_page
;
997 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1000 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1001 e4b
->bd_bitmap_page
= page
;
1002 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1004 if (blocks_per_page
>= 2) {
1005 /* buddy and bitmap are on the same page */
1010 pnum
= block
/ blocks_per_page
;
1011 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1014 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1015 e4b
->bd_buddy_page
= page
;
1019 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy
*e4b
)
1021 if (e4b
->bd_bitmap_page
) {
1022 unlock_page(e4b
->bd_bitmap_page
);
1023 page_cache_release(e4b
->bd_bitmap_page
);
1025 if (e4b
->bd_buddy_page
) {
1026 unlock_page(e4b
->bd_buddy_page
);
1027 page_cache_release(e4b
->bd_buddy_page
);
1032 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1033 * block group lock of all groups for this page; do not hold the BG lock when
1034 * calling this routine!
1036 static noinline_for_stack
1037 int ext4_mb_init_group(struct super_block
*sb
, ext4_group_t group
)
1040 struct ext4_group_info
*this_grp
;
1041 struct ext4_buddy e4b
;
1046 mb_debug(1, "init group %u\n", group
);
1047 this_grp
= ext4_get_group_info(sb
, group
);
1049 * This ensures that we don't reinit the buddy cache
1050 * page which map to the group from which we are already
1051 * allocating. If we are looking at the buddy cache we would
1052 * have taken a reference using ext4_mb_load_buddy and that
1053 * would have pinned buddy page to page cache.
1054 * The call to ext4_mb_get_buddy_page_lock will mark the
1057 ret
= ext4_mb_get_buddy_page_lock(sb
, group
, &e4b
);
1058 if (ret
|| !EXT4_MB_GRP_NEED_INIT(this_grp
)) {
1060 * somebody initialized the group
1061 * return without doing anything
1066 page
= e4b
.bd_bitmap_page
;
1067 ret
= ext4_mb_init_cache(page
, NULL
);
1070 if (!PageUptodate(page
)) {
1075 if (e4b
.bd_buddy_page
== NULL
) {
1077 * If both the bitmap and buddy are in
1078 * the same page we don't need to force
1084 /* init buddy cache */
1085 page
= e4b
.bd_buddy_page
;
1086 ret
= ext4_mb_init_cache(page
, e4b
.bd_bitmap
);
1089 if (!PageUptodate(page
)) {
1094 ext4_mb_put_buddy_page_lock(&e4b
);
1099 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1100 * block group lock of all groups for this page; do not hold the BG lock when
1101 * calling this routine!
1103 static noinline_for_stack
int
1104 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
1105 struct ext4_buddy
*e4b
)
1107 int blocks_per_page
;
1113 struct ext4_group_info
*grp
;
1114 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1115 struct inode
*inode
= sbi
->s_buddy_cache
;
1118 mb_debug(1, "load group %u\n", group
);
1120 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1121 grp
= ext4_get_group_info(sb
, group
);
1123 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
1126 e4b
->bd_group
= group
;
1127 e4b
->bd_buddy_page
= NULL
;
1128 e4b
->bd_bitmap_page
= NULL
;
1130 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1132 * we need full data about the group
1133 * to make a good selection
1135 ret
= ext4_mb_init_group(sb
, group
);
1141 * the buddy cache inode stores the block bitmap
1142 * and buddy information in consecutive blocks.
1143 * So for each group we need two blocks.
1146 pnum
= block
/ blocks_per_page
;
1147 poff
= block
% blocks_per_page
;
1149 /* we could use find_or_create_page(), but it locks page
1150 * what we'd like to avoid in fast path ... */
1151 page
= find_get_page_flags(inode
->i_mapping
, pnum
, FGP_ACCESSED
);
1152 if (page
== NULL
|| !PageUptodate(page
)) {
1155 * drop the page reference and try
1156 * to get the page with lock. If we
1157 * are not uptodate that implies
1158 * somebody just created the page but
1159 * is yet to initialize the same. So
1160 * wait for it to initialize.
1162 page_cache_release(page
);
1163 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1165 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1166 if (!PageUptodate(page
)) {
1167 ret
= ext4_mb_init_cache(page
, NULL
);
1172 mb_cmp_bitmaps(e4b
, page_address(page
) +
1173 (poff
* sb
->s_blocksize
));
1182 if (!PageUptodate(page
)) {
1187 /* Pages marked accessed already */
1188 e4b
->bd_bitmap_page
= page
;
1189 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1192 pnum
= block
/ blocks_per_page
;
1193 poff
= block
% blocks_per_page
;
1195 page
= find_get_page_flags(inode
->i_mapping
, pnum
, FGP_ACCESSED
);
1196 if (page
== NULL
|| !PageUptodate(page
)) {
1198 page_cache_release(page
);
1199 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1201 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1202 if (!PageUptodate(page
)) {
1203 ret
= ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
1216 if (!PageUptodate(page
)) {
1221 /* Pages marked accessed already */
1222 e4b
->bd_buddy_page
= page
;
1223 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
1225 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
1226 BUG_ON(e4b
->bd_buddy_page
== NULL
);
1232 page_cache_release(page
);
1233 if (e4b
->bd_bitmap_page
)
1234 page_cache_release(e4b
->bd_bitmap_page
);
1235 if (e4b
->bd_buddy_page
)
1236 page_cache_release(e4b
->bd_buddy_page
);
1237 e4b
->bd_buddy
= NULL
;
1238 e4b
->bd_bitmap
= NULL
;
1242 static void ext4_mb_unload_buddy(struct ext4_buddy
*e4b
)
1244 if (e4b
->bd_bitmap_page
)
1245 page_cache_release(e4b
->bd_bitmap_page
);
1246 if (e4b
->bd_buddy_page
)
1247 page_cache_release(e4b
->bd_buddy_page
);
1251 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
1256 BUG_ON(e4b
->bd_bitmap
== e4b
->bd_buddy
);
1257 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
1260 while (order
<= e4b
->bd_blkbits
+ 1) {
1262 if (!mb_test_bit(block
, bb
)) {
1263 /* this block is part of buddy of order 'order' */
1266 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1272 static void mb_clear_bits(void *bm
, int cur
, int len
)
1278 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1279 /* fast path: clear whole word at once */
1280 addr
= bm
+ (cur
>> 3);
1285 mb_clear_bit(cur
, bm
);
1290 /* clear bits in given range
1291 * will return first found zero bit if any, -1 otherwise
1293 static int mb_test_and_clear_bits(void *bm
, int cur
, int len
)
1300 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1301 /* fast path: clear whole word at once */
1302 addr
= bm
+ (cur
>> 3);
1303 if (*addr
!= (__u32
)(-1) && zero_bit
== -1)
1304 zero_bit
= cur
+ mb_find_next_zero_bit(addr
, 32, 0);
1309 if (!mb_test_and_clear_bit(cur
, bm
) && zero_bit
== -1)
1317 void ext4_set_bits(void *bm
, int cur
, int len
)
1323 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1324 /* fast path: set whole word at once */
1325 addr
= bm
+ (cur
>> 3);
1330 mb_set_bit(cur
, bm
);
1336 * _________________________________________________________________ */
1338 static inline int mb_buddy_adjust_border(int* bit
, void* bitmap
, int side
)
1340 if (mb_test_bit(*bit
+ side
, bitmap
)) {
1341 mb_clear_bit(*bit
, bitmap
);
1347 mb_set_bit(*bit
, bitmap
);
1352 static void mb_buddy_mark_free(struct ext4_buddy
*e4b
, int first
, int last
)
1356 void *buddy
= mb_find_buddy(e4b
, order
, &max
);
1361 /* Bits in range [first; last] are known to be set since
1362 * corresponding blocks were allocated. Bits in range
1363 * (first; last) will stay set because they form buddies on
1364 * upper layer. We just deal with borders if they don't
1365 * align with upper layer and then go up.
1366 * Releasing entire group is all about clearing
1367 * single bit of highest order buddy.
1371 * ---------------------------------
1373 * ---------------------------------
1374 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1375 * ---------------------------------
1377 * \_____________________/
1379 * Neither [1] nor [6] is aligned to above layer.
1380 * Left neighbour [0] is free, so mark it busy,
1381 * decrease bb_counters and extend range to
1383 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1384 * mark [6] free, increase bb_counters and shrink range to
1386 * Then shift range to [0; 2], go up and do the same.
1391 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&first
, buddy
, -1);
1393 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&last
, buddy
, 1);
1398 if (first
== last
|| !(buddy2
= mb_find_buddy(e4b
, order
, &max
))) {
1399 mb_clear_bits(buddy
, first
, last
- first
+ 1);
1400 e4b
->bd_info
->bb_counters
[order
- 1] += last
- first
+ 1;
1409 static void mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1410 int first
, int count
)
1412 int left_is_free
= 0;
1413 int right_is_free
= 0;
1415 int last
= first
+ count
- 1;
1416 struct super_block
*sb
= e4b
->bd_sb
;
1418 if (WARN_ON(count
== 0))
1420 BUG_ON(last
>= (sb
->s_blocksize
<< 3));
1421 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
1422 /* Don't bother if the block group is corrupt. */
1423 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
)))
1426 mb_check_buddy(e4b
);
1427 mb_free_blocks_double(inode
, e4b
, first
, count
);
1429 e4b
->bd_info
->bb_free
+= count
;
1430 if (first
< e4b
->bd_info
->bb_first_free
)
1431 e4b
->bd_info
->bb_first_free
= first
;
1433 /* access memory sequentially: check left neighbour,
1434 * clear range and then check right neighbour
1437 left_is_free
= !mb_test_bit(first
- 1, e4b
->bd_bitmap
);
1438 block
= mb_test_and_clear_bits(e4b
->bd_bitmap
, first
, count
);
1439 if (last
+ 1 < EXT4_SB(sb
)->s_mb_maxs
[0])
1440 right_is_free
= !mb_test_bit(last
+ 1, e4b
->bd_bitmap
);
1442 if (unlikely(block
!= -1)) {
1443 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1444 ext4_fsblk_t blocknr
;
1446 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1447 blocknr
+= EXT4_C2B(EXT4_SB(sb
), block
);
1448 ext4_grp_locked_error(sb
, e4b
->bd_group
,
1449 inode
? inode
->i_ino
: 0,
1451 "freeing already freed block "
1452 "(bit %u); block bitmap corrupt.",
1454 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
))
1455 percpu_counter_sub(&sbi
->s_freeclusters_counter
,
1456 e4b
->bd_info
->bb_free
);
1457 /* Mark the block group as corrupt. */
1458 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT
,
1459 &e4b
->bd_info
->bb_state
);
1460 mb_regenerate_buddy(e4b
);
1464 /* let's maintain fragments counter */
1465 if (left_is_free
&& right_is_free
)
1466 e4b
->bd_info
->bb_fragments
--;
1467 else if (!left_is_free
&& !right_is_free
)
1468 e4b
->bd_info
->bb_fragments
++;
1470 /* buddy[0] == bd_bitmap is a special case, so handle
1471 * it right away and let mb_buddy_mark_free stay free of
1472 * zero order checks.
1473 * Check if neighbours are to be coaleasced,
1474 * adjust bitmap bb_counters and borders appropriately.
1477 first
+= !left_is_free
;
1478 e4b
->bd_info
->bb_counters
[0] += left_is_free
? -1 : 1;
1481 last
-= !right_is_free
;
1482 e4b
->bd_info
->bb_counters
[0] += right_is_free
? -1 : 1;
1486 mb_buddy_mark_free(e4b
, first
>> 1, last
>> 1);
1489 mb_set_largest_free_order(sb
, e4b
->bd_info
);
1490 mb_check_buddy(e4b
);
1493 static int mb_find_extent(struct ext4_buddy
*e4b
, int block
,
1494 int needed
, struct ext4_free_extent
*ex
)
1500 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1503 buddy
= mb_find_buddy(e4b
, 0, &max
);
1504 BUG_ON(buddy
== NULL
);
1505 BUG_ON(block
>= max
);
1506 if (mb_test_bit(block
, buddy
)) {
1513 /* find actual order */
1514 order
= mb_find_order_for_block(e4b
, block
);
1515 block
= block
>> order
;
1517 ex
->fe_len
= 1 << order
;
1518 ex
->fe_start
= block
<< order
;
1519 ex
->fe_group
= e4b
->bd_group
;
1521 /* calc difference from given start */
1522 next
= next
- ex
->fe_start
;
1524 ex
->fe_start
+= next
;
1526 while (needed
> ex
->fe_len
&&
1527 mb_find_buddy(e4b
, order
, &max
)) {
1529 if (block
+ 1 >= max
)
1532 next
= (block
+ 1) * (1 << order
);
1533 if (mb_test_bit(next
, e4b
->bd_bitmap
))
1536 order
= mb_find_order_for_block(e4b
, next
);
1538 block
= next
>> order
;
1539 ex
->fe_len
+= 1 << order
;
1542 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1546 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1552 int start
= ex
->fe_start
;
1553 int len
= ex
->fe_len
;
1558 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1559 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1560 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1561 mb_check_buddy(e4b
);
1562 mb_mark_used_double(e4b
, start
, len
);
1564 e4b
->bd_info
->bb_free
-= len
;
1565 if (e4b
->bd_info
->bb_first_free
== start
)
1566 e4b
->bd_info
->bb_first_free
+= len
;
1568 /* let's maintain fragments counter */
1570 mlen
= !mb_test_bit(start
- 1, e4b
->bd_bitmap
);
1571 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1572 max
= !mb_test_bit(start
+ len
, e4b
->bd_bitmap
);
1574 e4b
->bd_info
->bb_fragments
++;
1575 else if (!mlen
&& !max
)
1576 e4b
->bd_info
->bb_fragments
--;
1578 /* let's maintain buddy itself */
1580 ord
= mb_find_order_for_block(e4b
, start
);
1582 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1583 /* the whole chunk may be allocated at once! */
1585 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1586 BUG_ON((start
>> ord
) >= max
);
1587 mb_set_bit(start
>> ord
, buddy
);
1588 e4b
->bd_info
->bb_counters
[ord
]--;
1595 /* store for history */
1597 ret
= len
| (ord
<< 16);
1599 /* we have to split large buddy */
1601 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1602 mb_set_bit(start
>> ord
, buddy
);
1603 e4b
->bd_info
->bb_counters
[ord
]--;
1606 cur
= (start
>> ord
) & ~1U;
1607 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1608 mb_clear_bit(cur
, buddy
);
1609 mb_clear_bit(cur
+ 1, buddy
);
1610 e4b
->bd_info
->bb_counters
[ord
]++;
1611 e4b
->bd_info
->bb_counters
[ord
]++;
1613 mb_set_largest_free_order(e4b
->bd_sb
, e4b
->bd_info
);
1615 ext4_set_bits(e4b
->bd_bitmap
, ex
->fe_start
, len0
);
1616 mb_check_buddy(e4b
);
1622 * Must be called under group lock!
1624 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1625 struct ext4_buddy
*e4b
)
1627 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1630 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1631 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1633 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1634 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1635 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1637 /* preallocation can change ac_b_ex, thus we store actually
1638 * allocated blocks for history */
1639 ac
->ac_f_ex
= ac
->ac_b_ex
;
1641 ac
->ac_status
= AC_STATUS_FOUND
;
1642 ac
->ac_tail
= ret
& 0xffff;
1643 ac
->ac_buddy
= ret
>> 16;
1646 * take the page reference. We want the page to be pinned
1647 * so that we don't get a ext4_mb_init_cache_call for this
1648 * group until we update the bitmap. That would mean we
1649 * double allocate blocks. The reference is dropped
1650 * in ext4_mb_release_context
1652 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1653 get_page(ac
->ac_bitmap_page
);
1654 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1655 get_page(ac
->ac_buddy_page
);
1656 /* store last allocated for subsequent stream allocation */
1657 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
1658 spin_lock(&sbi
->s_md_lock
);
1659 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1660 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1661 spin_unlock(&sbi
->s_md_lock
);
1666 * regular allocator, for general purposes allocation
1669 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1670 struct ext4_buddy
*e4b
,
1673 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1674 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1675 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1676 struct ext4_free_extent ex
;
1679 if (ac
->ac_status
== AC_STATUS_FOUND
)
1682 * We don't want to scan for a whole year
1684 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1685 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1686 ac
->ac_status
= AC_STATUS_BREAK
;
1691 * Haven't found good chunk so far, let's continue
1693 if (bex
->fe_len
< gex
->fe_len
)
1696 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1697 && bex
->fe_group
== e4b
->bd_group
) {
1698 /* recheck chunk's availability - we don't know
1699 * when it was found (within this lock-unlock
1701 max
= mb_find_extent(e4b
, bex
->fe_start
, gex
->fe_len
, &ex
);
1702 if (max
>= gex
->fe_len
) {
1703 ext4_mb_use_best_found(ac
, e4b
);
1710 * The routine checks whether found extent is good enough. If it is,
1711 * then the extent gets marked used and flag is set to the context
1712 * to stop scanning. Otherwise, the extent is compared with the
1713 * previous found extent and if new one is better, then it's stored
1714 * in the context. Later, the best found extent will be used, if
1715 * mballoc can't find good enough extent.
1717 * FIXME: real allocation policy is to be designed yet!
1719 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1720 struct ext4_free_extent
*ex
,
1721 struct ext4_buddy
*e4b
)
1723 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1724 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1726 BUG_ON(ex
->fe_len
<= 0);
1727 BUG_ON(ex
->fe_len
> EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1728 BUG_ON(ex
->fe_start
>= EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1729 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1734 * The special case - take what you catch first
1736 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1738 ext4_mb_use_best_found(ac
, e4b
);
1743 * Let's check whether the chuck is good enough
1745 if (ex
->fe_len
== gex
->fe_len
) {
1747 ext4_mb_use_best_found(ac
, e4b
);
1752 * If this is first found extent, just store it in the context
1754 if (bex
->fe_len
== 0) {
1760 * If new found extent is better, store it in the context
1762 if (bex
->fe_len
< gex
->fe_len
) {
1763 /* if the request isn't satisfied, any found extent
1764 * larger than previous best one is better */
1765 if (ex
->fe_len
> bex
->fe_len
)
1767 } else if (ex
->fe_len
> gex
->fe_len
) {
1768 /* if the request is satisfied, then we try to find
1769 * an extent that still satisfy the request, but is
1770 * smaller than previous one */
1771 if (ex
->fe_len
< bex
->fe_len
)
1775 ext4_mb_check_limits(ac
, e4b
, 0);
1778 static noinline_for_stack
1779 int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1780 struct ext4_buddy
*e4b
)
1782 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1783 ext4_group_t group
= ex
.fe_group
;
1787 BUG_ON(ex
.fe_len
<= 0);
1788 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1792 ext4_lock_group(ac
->ac_sb
, group
);
1793 max
= mb_find_extent(e4b
, ex
.fe_start
, ex
.fe_len
, &ex
);
1797 ext4_mb_use_best_found(ac
, e4b
);
1800 ext4_unlock_group(ac
->ac_sb
, group
);
1801 ext4_mb_unload_buddy(e4b
);
1806 static noinline_for_stack
1807 int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1808 struct ext4_buddy
*e4b
)
1810 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1813 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1814 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1815 struct ext4_free_extent ex
;
1817 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1819 if (grp
->bb_free
== 0)
1822 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1826 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
))) {
1827 ext4_mb_unload_buddy(e4b
);
1831 ext4_lock_group(ac
->ac_sb
, group
);
1832 max
= mb_find_extent(e4b
, ac
->ac_g_ex
.fe_start
,
1833 ac
->ac_g_ex
.fe_len
, &ex
);
1834 ex
.fe_logical
= 0xDEADFA11; /* debug value */
1836 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1839 start
= ext4_group_first_block_no(ac
->ac_sb
, e4b
->bd_group
) +
1841 /* use do_div to get remainder (would be 64-bit modulo) */
1842 if (do_div(start
, sbi
->s_stripe
) == 0) {
1845 ext4_mb_use_best_found(ac
, e4b
);
1847 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1848 BUG_ON(ex
.fe_len
<= 0);
1849 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1850 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1853 ext4_mb_use_best_found(ac
, e4b
);
1854 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1855 /* Sometimes, caller may want to merge even small
1856 * number of blocks to an existing extent */
1857 BUG_ON(ex
.fe_len
<= 0);
1858 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1859 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1862 ext4_mb_use_best_found(ac
, e4b
);
1864 ext4_unlock_group(ac
->ac_sb
, group
);
1865 ext4_mb_unload_buddy(e4b
);
1871 * The routine scans buddy structures (not bitmap!) from given order
1872 * to max order and tries to find big enough chunk to satisfy the req
1874 static noinline_for_stack
1875 void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1876 struct ext4_buddy
*e4b
)
1878 struct super_block
*sb
= ac
->ac_sb
;
1879 struct ext4_group_info
*grp
= e4b
->bd_info
;
1885 BUG_ON(ac
->ac_2order
<= 0);
1886 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1887 if (grp
->bb_counters
[i
] == 0)
1890 buddy
= mb_find_buddy(e4b
, i
, &max
);
1891 BUG_ON(buddy
== NULL
);
1893 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1898 ac
->ac_b_ex
.fe_len
= 1 << i
;
1899 ac
->ac_b_ex
.fe_start
= k
<< i
;
1900 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1902 ext4_mb_use_best_found(ac
, e4b
);
1904 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1906 if (EXT4_SB(sb
)->s_mb_stats
)
1907 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1914 * The routine scans the group and measures all found extents.
1915 * In order to optimize scanning, caller must pass number of
1916 * free blocks in the group, so the routine can know upper limit.
1918 static noinline_for_stack
1919 void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1920 struct ext4_buddy
*e4b
)
1922 struct super_block
*sb
= ac
->ac_sb
;
1923 void *bitmap
= e4b
->bd_bitmap
;
1924 struct ext4_free_extent ex
;
1928 free
= e4b
->bd_info
->bb_free
;
1931 i
= e4b
->bd_info
->bb_first_free
;
1933 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1934 i
= mb_find_next_zero_bit(bitmap
,
1935 EXT4_CLUSTERS_PER_GROUP(sb
), i
);
1936 if (i
>= EXT4_CLUSTERS_PER_GROUP(sb
)) {
1938 * IF we have corrupt bitmap, we won't find any
1939 * free blocks even though group info says we
1940 * we have free blocks
1942 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1943 "%d free clusters as per "
1944 "group info. But bitmap says 0",
1949 mb_find_extent(e4b
, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1950 BUG_ON(ex
.fe_len
<= 0);
1951 if (free
< ex
.fe_len
) {
1952 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1953 "%d free clusters as per "
1954 "group info. But got %d blocks",
1957 * The number of free blocks differs. This mostly
1958 * indicate that the bitmap is corrupt. So exit
1959 * without claiming the space.
1963 ex
.fe_logical
= 0xDEADC0DE; /* debug value */
1964 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1970 ext4_mb_check_limits(ac
, e4b
, 1);
1974 * This is a special case for storages like raid5
1975 * we try to find stripe-aligned chunks for stripe-size-multiple requests
1977 static noinline_for_stack
1978 void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1979 struct ext4_buddy
*e4b
)
1981 struct super_block
*sb
= ac
->ac_sb
;
1982 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1983 void *bitmap
= e4b
->bd_bitmap
;
1984 struct ext4_free_extent ex
;
1985 ext4_fsblk_t first_group_block
;
1990 BUG_ON(sbi
->s_stripe
== 0);
1992 /* find first stripe-aligned block in group */
1993 first_group_block
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1995 a
= first_group_block
+ sbi
->s_stripe
- 1;
1996 do_div(a
, sbi
->s_stripe
);
1997 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1999 while (i
< EXT4_CLUSTERS_PER_GROUP(sb
)) {
2000 if (!mb_test_bit(i
, bitmap
)) {
2001 max
= mb_find_extent(e4b
, i
, sbi
->s_stripe
, &ex
);
2002 if (max
>= sbi
->s_stripe
) {
2004 ex
.fe_logical
= 0xDEADF00D; /* debug value */
2006 ext4_mb_use_best_found(ac
, e4b
);
2015 * This is now called BEFORE we load the buddy bitmap.
2016 * Returns either 1 or 0 indicating that the group is either suitable
2017 * for the allocation or not. In addition it can also return negative
2018 * error code when something goes wrong.
2020 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
2021 ext4_group_t group
, int cr
)
2023 unsigned free
, fragments
;
2024 int flex_size
= ext4_flex_bg_size(EXT4_SB(ac
->ac_sb
));
2025 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
2027 BUG_ON(cr
< 0 || cr
>= 4);
2029 free
= grp
->bb_free
;
2032 if (cr
<= 2 && free
< ac
->ac_g_ex
.fe_len
)
2035 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp
)))
2038 /* We only do this if the grp has never been initialized */
2039 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
2040 int ret
= ext4_mb_init_group(ac
->ac_sb
, group
);
2045 fragments
= grp
->bb_fragments
;
2051 BUG_ON(ac
->ac_2order
== 0);
2053 /* Avoid using the first bg of a flexgroup for data files */
2054 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
) &&
2055 (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) &&
2056 ((group
% flex_size
) == 0))
2059 if ((ac
->ac_2order
> ac
->ac_sb
->s_blocksize_bits
+1) ||
2060 (free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2063 if (grp
->bb_largest_free_order
< ac
->ac_2order
)
2068 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2072 if (free
>= ac
->ac_g_ex
.fe_len
)
2084 static noinline_for_stack
int
2085 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
2087 ext4_group_t ngroups
, group
, i
;
2089 int err
= 0, first_err
= 0;
2090 struct ext4_sb_info
*sbi
;
2091 struct super_block
*sb
;
2092 struct ext4_buddy e4b
;
2096 ngroups
= ext4_get_groups_count(sb
);
2097 /* non-extent files are limited to low blocks/groups */
2098 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)))
2099 ngroups
= sbi
->s_blockfile_groups
;
2101 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
2103 /* first, try the goal */
2104 err
= ext4_mb_find_by_goal(ac
, &e4b
);
2105 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
2108 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2112 * ac->ac2_order is set only if the fe_len is a power of 2
2113 * if ac2_order is set we also set criteria to 0 so that we
2114 * try exact allocation using buddy.
2116 i
= fls(ac
->ac_g_ex
.fe_len
);
2119 * We search using buddy data only if the order of the request
2120 * is greater than equal to the sbi_s_mb_order2_reqs
2121 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2123 if (i
>= sbi
->s_mb_order2_reqs
) {
2125 * This should tell if fe_len is exactly power of 2
2127 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
2128 ac
->ac_2order
= i
- 1;
2131 /* if stream allocation is enabled, use global goal */
2132 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
2133 /* TBD: may be hot point */
2134 spin_lock(&sbi
->s_md_lock
);
2135 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
2136 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
2137 spin_unlock(&sbi
->s_md_lock
);
2140 /* Let's just scan groups to find more-less suitable blocks */
2141 cr
= ac
->ac_2order
? 0 : 1;
2143 * cr == 0 try to get exact allocation,
2144 * cr == 3 try to get anything
2147 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
2148 ac
->ac_criteria
= cr
;
2150 * searching for the right group start
2151 * from the goal value specified
2153 group
= ac
->ac_g_ex
.fe_group
;
2155 for (i
= 0; i
< ngroups
; group
++, i
++) {
2159 * Artificially restricted ngroups for non-extent
2160 * files makes group > ngroups possible on first loop.
2162 if (group
>= ngroups
)
2165 /* This now checks without needing the buddy page */
2166 ret
= ext4_mb_good_group(ac
, group
, cr
);
2173 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2177 ext4_lock_group(sb
, group
);
2180 * We need to check again after locking the
2183 ret
= ext4_mb_good_group(ac
, group
, cr
);
2185 ext4_unlock_group(sb
, group
);
2186 ext4_mb_unload_buddy(&e4b
);
2192 ac
->ac_groups_scanned
++;
2193 if (cr
== 0 && ac
->ac_2order
< sb
->s_blocksize_bits
+2)
2194 ext4_mb_simple_scan_group(ac
, &e4b
);
2195 else if (cr
== 1 && sbi
->s_stripe
&&
2196 !(ac
->ac_g_ex
.fe_len
% sbi
->s_stripe
))
2197 ext4_mb_scan_aligned(ac
, &e4b
);
2199 ext4_mb_complex_scan_group(ac
, &e4b
);
2201 ext4_unlock_group(sb
, group
);
2202 ext4_mb_unload_buddy(&e4b
);
2204 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
2209 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
2210 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
2212 * We've been searching too long. Let's try to allocate
2213 * the best chunk we've found so far
2216 ext4_mb_try_best_found(ac
, &e4b
);
2217 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
2219 * Someone more lucky has already allocated it.
2220 * The only thing we can do is just take first
2222 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2224 ac
->ac_b_ex
.fe_group
= 0;
2225 ac
->ac_b_ex
.fe_start
= 0;
2226 ac
->ac_b_ex
.fe_len
= 0;
2227 ac
->ac_status
= AC_STATUS_CONTINUE
;
2228 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
2230 atomic_inc(&sbi
->s_mb_lost_chunks
);
2235 if (!err
&& ac
->ac_status
!= AC_STATUS_FOUND
&& first_err
)
2240 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2242 struct super_block
*sb
= seq
->private;
2245 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2248 return (void *) ((unsigned long) group
);
2251 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2253 struct super_block
*sb
= seq
->private;
2257 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2260 return (void *) ((unsigned long) group
);
2263 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2265 struct super_block
*sb
= seq
->private;
2266 ext4_group_t group
= (ext4_group_t
) ((unsigned long) v
);
2268 int err
, buddy_loaded
= 0;
2269 struct ext4_buddy e4b
;
2270 struct ext4_group_info
*grinfo
;
2272 struct ext4_group_info info
;
2273 ext4_grpblk_t counters
[16];
2278 seq_puts(seq
, "#group: free frags first ["
2279 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
2280 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]");
2282 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2283 sizeof(struct ext4_group_info
);
2284 grinfo
= ext4_get_group_info(sb
, group
);
2285 /* Load the group info in memory only if not already loaded. */
2286 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo
))) {
2287 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2289 seq_printf(seq
, "#%-5u: I/O error\n", group
);
2295 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2298 ext4_mb_unload_buddy(&e4b
);
2300 seq_printf(seq
, "#%-5u: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2301 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2302 for (i
= 0; i
<= 13; i
++)
2303 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2304 sg
.info
.bb_counters
[i
] : 0);
2305 seq_printf(seq
, " ]\n");
2310 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2314 static const struct seq_operations ext4_mb_seq_groups_ops
= {
2315 .start
= ext4_mb_seq_groups_start
,
2316 .next
= ext4_mb_seq_groups_next
,
2317 .stop
= ext4_mb_seq_groups_stop
,
2318 .show
= ext4_mb_seq_groups_show
,
2321 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2323 struct super_block
*sb
= PDE_DATA(inode
);
2326 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2328 struct seq_file
*m
= file
->private_data
;
2335 static const struct file_operations ext4_mb_seq_groups_fops
= {
2336 .owner
= THIS_MODULE
,
2337 .open
= ext4_mb_seq_groups_open
,
2339 .llseek
= seq_lseek
,
2340 .release
= seq_release
,
2343 static struct kmem_cache
*get_groupinfo_cache(int blocksize_bits
)
2345 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2346 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[cache_index
];
2353 * Allocate the top-level s_group_info array for the specified number
2356 int ext4_mb_alloc_groupinfo(struct super_block
*sb
, ext4_group_t ngroups
)
2358 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2360 struct ext4_group_info
***new_groupinfo
;
2362 size
= (ngroups
+ EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2363 EXT4_DESC_PER_BLOCK_BITS(sb
);
2364 if (size
<= sbi
->s_group_info_size
)
2367 size
= roundup_pow_of_two(sizeof(*sbi
->s_group_info
) * size
);
2368 new_groupinfo
= ext4_kvzalloc(size
, GFP_KERNEL
);
2369 if (!new_groupinfo
) {
2370 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy meta group");
2373 if (sbi
->s_group_info
) {
2374 memcpy(new_groupinfo
, sbi
->s_group_info
,
2375 sbi
->s_group_info_size
* sizeof(*sbi
->s_group_info
));
2376 kvfree(sbi
->s_group_info
);
2378 sbi
->s_group_info
= new_groupinfo
;
2379 sbi
->s_group_info_size
= size
/ sizeof(*sbi
->s_group_info
);
2380 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2381 sbi
->s_group_info_size
);
2385 /* Create and initialize ext4_group_info data for the given group. */
2386 int ext4_mb_add_groupinfo(struct super_block
*sb
, ext4_group_t group
,
2387 struct ext4_group_desc
*desc
)
2391 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2392 struct ext4_group_info
**meta_group_info
;
2393 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2396 * First check if this group is the first of a reserved block.
2397 * If it's true, we have to allocate a new table of pointers
2398 * to ext4_group_info structures
2400 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2401 metalen
= sizeof(*meta_group_info
) <<
2402 EXT4_DESC_PER_BLOCK_BITS(sb
);
2403 meta_group_info
= kmalloc(metalen
, GFP_NOFS
);
2404 if (meta_group_info
== NULL
) {
2405 ext4_msg(sb
, KERN_ERR
, "can't allocate mem "
2406 "for a buddy group");
2407 goto exit_meta_group_info
;
2409 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] =
2414 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2415 i
= group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2417 meta_group_info
[i
] = kmem_cache_zalloc(cachep
, GFP_NOFS
);
2418 if (meta_group_info
[i
] == NULL
) {
2419 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy mem");
2420 goto exit_group_info
;
2422 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2423 &(meta_group_info
[i
]->bb_state
));
2426 * initialize bb_free to be able to skip
2427 * empty groups without initialization
2429 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2430 meta_group_info
[i
]->bb_free
=
2431 ext4_free_clusters_after_init(sb
, group
, desc
);
2433 meta_group_info
[i
]->bb_free
=
2434 ext4_free_group_clusters(sb
, desc
);
2437 INIT_LIST_HEAD(&meta_group_info
[i
]->bb_prealloc_list
);
2438 init_rwsem(&meta_group_info
[i
]->alloc_sem
);
2439 meta_group_info
[i
]->bb_free_root
= RB_ROOT
;
2440 meta_group_info
[i
]->bb_largest_free_order
= -1; /* uninit */
2444 struct buffer_head
*bh
;
2445 meta_group_info
[i
]->bb_bitmap
=
2446 kmalloc(sb
->s_blocksize
, GFP_NOFS
);
2447 BUG_ON(meta_group_info
[i
]->bb_bitmap
== NULL
);
2448 bh
= ext4_read_block_bitmap(sb
, group
);
2450 memcpy(meta_group_info
[i
]->bb_bitmap
, bh
->b_data
,
2459 /* If a meta_group_info table has been allocated, release it now */
2460 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2461 kfree(sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)]);
2462 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] = NULL
;
2464 exit_meta_group_info
:
2466 } /* ext4_mb_add_groupinfo */
2468 static int ext4_mb_init_backend(struct super_block
*sb
)
2470 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2472 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2474 struct ext4_group_desc
*desc
;
2475 struct kmem_cache
*cachep
;
2477 err
= ext4_mb_alloc_groupinfo(sb
, ngroups
);
2481 sbi
->s_buddy_cache
= new_inode(sb
);
2482 if (sbi
->s_buddy_cache
== NULL
) {
2483 ext4_msg(sb
, KERN_ERR
, "can't get new inode");
2486 /* To avoid potentially colliding with an valid on-disk inode number,
2487 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2488 * not in the inode hash, so it should never be found by iget(), but
2489 * this will avoid confusion if it ever shows up during debugging. */
2490 sbi
->s_buddy_cache
->i_ino
= EXT4_BAD_INO
;
2491 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2492 for (i
= 0; i
< ngroups
; i
++) {
2493 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2495 ext4_msg(sb
, KERN_ERR
, "can't read descriptor %u", i
);
2498 if (ext4_mb_add_groupinfo(sb
, i
, desc
) != 0)
2505 cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2507 kmem_cache_free(cachep
, ext4_get_group_info(sb
, i
));
2508 i
= sbi
->s_group_info_size
;
2510 kfree(sbi
->s_group_info
[i
]);
2511 iput(sbi
->s_buddy_cache
);
2513 kvfree(sbi
->s_group_info
);
2517 static void ext4_groupinfo_destroy_slabs(void)
2521 for (i
= 0; i
< NR_GRPINFO_CACHES
; i
++) {
2522 if (ext4_groupinfo_caches
[i
])
2523 kmem_cache_destroy(ext4_groupinfo_caches
[i
]);
2524 ext4_groupinfo_caches
[i
] = NULL
;
2528 static int ext4_groupinfo_create_slab(size_t size
)
2530 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex
);
2532 int blocksize_bits
= order_base_2(size
);
2533 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2534 struct kmem_cache
*cachep
;
2536 if (cache_index
>= NR_GRPINFO_CACHES
)
2539 if (unlikely(cache_index
< 0))
2542 mutex_lock(&ext4_grpinfo_slab_create_mutex
);
2543 if (ext4_groupinfo_caches
[cache_index
]) {
2544 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2545 return 0; /* Already created */
2548 slab_size
= offsetof(struct ext4_group_info
,
2549 bb_counters
[blocksize_bits
+ 2]);
2551 cachep
= kmem_cache_create(ext4_groupinfo_slab_names
[cache_index
],
2552 slab_size
, 0, SLAB_RECLAIM_ACCOUNT
,
2555 ext4_groupinfo_caches
[cache_index
] = cachep
;
2557 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2560 "EXT4-fs: no memory for groupinfo slab cache\n");
2567 int ext4_mb_init(struct super_block
*sb
)
2569 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2575 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_offsets
);
2577 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2578 if (sbi
->s_mb_offsets
== NULL
) {
2583 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_maxs
);
2584 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2585 if (sbi
->s_mb_maxs
== NULL
) {
2590 ret
= ext4_groupinfo_create_slab(sb
->s_blocksize
);
2594 /* order 0 is regular bitmap */
2595 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2596 sbi
->s_mb_offsets
[0] = 0;
2600 max
= sb
->s_blocksize
<< 2;
2602 sbi
->s_mb_offsets
[i
] = offset
;
2603 sbi
->s_mb_maxs
[i
] = max
;
2604 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2607 } while (i
<= sb
->s_blocksize_bits
+ 1);
2609 spin_lock_init(&sbi
->s_md_lock
);
2610 spin_lock_init(&sbi
->s_bal_lock
);
2612 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2613 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2614 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2615 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2616 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2618 * The default group preallocation is 512, which for 4k block
2619 * sizes translates to 2 megabytes. However for bigalloc file
2620 * systems, this is probably too big (i.e, if the cluster size
2621 * is 1 megabyte, then group preallocation size becomes half a
2622 * gigabyte!). As a default, we will keep a two megabyte
2623 * group pralloc size for cluster sizes up to 64k, and after
2624 * that, we will force a minimum group preallocation size of
2625 * 32 clusters. This translates to 8 megs when the cluster
2626 * size is 256k, and 32 megs when the cluster size is 1 meg,
2627 * which seems reasonable as a default.
2629 sbi
->s_mb_group_prealloc
= max(MB_DEFAULT_GROUP_PREALLOC
>>
2630 sbi
->s_cluster_bits
, 32);
2632 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2633 * to the lowest multiple of s_stripe which is bigger than
2634 * the s_mb_group_prealloc as determined above. We want
2635 * the preallocation size to be an exact multiple of the
2636 * RAID stripe size so that preallocations don't fragment
2639 if (sbi
->s_stripe
> 1) {
2640 sbi
->s_mb_group_prealloc
= roundup(
2641 sbi
->s_mb_group_prealloc
, sbi
->s_stripe
);
2644 sbi
->s_locality_groups
= alloc_percpu(struct ext4_locality_group
);
2645 if (sbi
->s_locality_groups
== NULL
) {
2649 for_each_possible_cpu(i
) {
2650 struct ext4_locality_group
*lg
;
2651 lg
= per_cpu_ptr(sbi
->s_locality_groups
, i
);
2652 mutex_init(&lg
->lg_mutex
);
2653 for (j
= 0; j
< PREALLOC_TB_SIZE
; j
++)
2654 INIT_LIST_HEAD(&lg
->lg_prealloc_list
[j
]);
2655 spin_lock_init(&lg
->lg_prealloc_lock
);
2658 /* init file for buddy data */
2659 ret
= ext4_mb_init_backend(sb
);
2661 goto out_free_locality_groups
;
2664 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_proc
,
2665 &ext4_mb_seq_groups_fops
, sb
);
2669 out_free_locality_groups
:
2670 free_percpu(sbi
->s_locality_groups
);
2671 sbi
->s_locality_groups
= NULL
;
2673 kfree(sbi
->s_mb_offsets
);
2674 sbi
->s_mb_offsets
= NULL
;
2675 kfree(sbi
->s_mb_maxs
);
2676 sbi
->s_mb_maxs
= NULL
;
2680 /* need to called with the ext4 group lock held */
2681 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2683 struct ext4_prealloc_space
*pa
;
2684 struct list_head
*cur
, *tmp
;
2687 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2688 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2689 list_del(&pa
->pa_group_list
);
2691 kmem_cache_free(ext4_pspace_cachep
, pa
);
2694 mb_debug(1, "mballoc: %u PAs left\n", count
);
2698 int ext4_mb_release(struct super_block
*sb
)
2700 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2702 int num_meta_group_infos
;
2703 struct ext4_group_info
*grinfo
;
2704 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2705 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2708 remove_proc_entry("mb_groups", sbi
->s_proc
);
2710 if (sbi
->s_group_info
) {
2711 for (i
= 0; i
< ngroups
; i
++) {
2712 grinfo
= ext4_get_group_info(sb
, i
);
2714 kfree(grinfo
->bb_bitmap
);
2716 ext4_lock_group(sb
, i
);
2717 ext4_mb_cleanup_pa(grinfo
);
2718 ext4_unlock_group(sb
, i
);
2719 kmem_cache_free(cachep
, grinfo
);
2721 num_meta_group_infos
= (ngroups
+
2722 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2723 EXT4_DESC_PER_BLOCK_BITS(sb
);
2724 for (i
= 0; i
< num_meta_group_infos
; i
++)
2725 kfree(sbi
->s_group_info
[i
]);
2726 kvfree(sbi
->s_group_info
);
2728 kfree(sbi
->s_mb_offsets
);
2729 kfree(sbi
->s_mb_maxs
);
2730 iput(sbi
->s_buddy_cache
);
2731 if (sbi
->s_mb_stats
) {
2732 ext4_msg(sb
, KERN_INFO
,
2733 "mballoc: %u blocks %u reqs (%u success)",
2734 atomic_read(&sbi
->s_bal_allocated
),
2735 atomic_read(&sbi
->s_bal_reqs
),
2736 atomic_read(&sbi
->s_bal_success
));
2737 ext4_msg(sb
, KERN_INFO
,
2738 "mballoc: %u extents scanned, %u goal hits, "
2739 "%u 2^N hits, %u breaks, %u lost",
2740 atomic_read(&sbi
->s_bal_ex_scanned
),
2741 atomic_read(&sbi
->s_bal_goals
),
2742 atomic_read(&sbi
->s_bal_2orders
),
2743 atomic_read(&sbi
->s_bal_breaks
),
2744 atomic_read(&sbi
->s_mb_lost_chunks
));
2745 ext4_msg(sb
, KERN_INFO
,
2746 "mballoc: %lu generated and it took %Lu",
2747 sbi
->s_mb_buddies_generated
,
2748 sbi
->s_mb_generation_time
);
2749 ext4_msg(sb
, KERN_INFO
,
2750 "mballoc: %u preallocated, %u discarded",
2751 atomic_read(&sbi
->s_mb_preallocated
),
2752 atomic_read(&sbi
->s_mb_discarded
));
2755 free_percpu(sbi
->s_locality_groups
);
2760 static inline int ext4_issue_discard(struct super_block
*sb
,
2761 ext4_group_t block_group
, ext4_grpblk_t cluster
, int count
)
2763 ext4_fsblk_t discard_block
;
2765 discard_block
= (EXT4_C2B(EXT4_SB(sb
), cluster
) +
2766 ext4_group_first_block_no(sb
, block_group
));
2767 count
= EXT4_C2B(EXT4_SB(sb
), count
);
2768 trace_ext4_discard_blocks(sb
,
2769 (unsigned long long) discard_block
, count
);
2770 return sb_issue_discard(sb
, discard_block
, count
, GFP_NOFS
, 0);
2774 * This function is called by the jbd2 layer once the commit has finished,
2775 * so we know we can free the blocks that were released with that commit.
2777 static void ext4_free_data_callback(struct super_block
*sb
,
2778 struct ext4_journal_cb_entry
*jce
,
2781 struct ext4_free_data
*entry
= (struct ext4_free_data
*)jce
;
2782 struct ext4_buddy e4b
;
2783 struct ext4_group_info
*db
;
2784 int err
, count
= 0, count2
= 0;
2786 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2787 entry
->efd_count
, entry
->efd_group
, entry
);
2789 if (test_opt(sb
, DISCARD
)) {
2790 err
= ext4_issue_discard(sb
, entry
->efd_group
,
2791 entry
->efd_start_cluster
,
2793 if (err
&& err
!= -EOPNOTSUPP
)
2794 ext4_msg(sb
, KERN_WARNING
, "discard request in"
2795 " group:%d block:%d count:%d failed"
2796 " with %d", entry
->efd_group
,
2797 entry
->efd_start_cluster
,
2798 entry
->efd_count
, err
);
2801 err
= ext4_mb_load_buddy(sb
, entry
->efd_group
, &e4b
);
2802 /* we expect to find existing buddy because it's pinned */
2807 /* there are blocks to put in buddy to make them really free */
2808 count
+= entry
->efd_count
;
2810 ext4_lock_group(sb
, entry
->efd_group
);
2811 /* Take it out of per group rb tree */
2812 rb_erase(&entry
->efd_node
, &(db
->bb_free_root
));
2813 mb_free_blocks(NULL
, &e4b
, entry
->efd_start_cluster
, entry
->efd_count
);
2816 * Clear the trimmed flag for the group so that the next
2817 * ext4_trim_fs can trim it.
2818 * If the volume is mounted with -o discard, online discard
2819 * is supported and the free blocks will be trimmed online.
2821 if (!test_opt(sb
, DISCARD
))
2822 EXT4_MB_GRP_CLEAR_TRIMMED(db
);
2824 if (!db
->bb_free_root
.rb_node
) {
2825 /* No more items in the per group rb tree
2826 * balance refcounts from ext4_mb_free_metadata()
2828 page_cache_release(e4b
.bd_buddy_page
);
2829 page_cache_release(e4b
.bd_bitmap_page
);
2831 ext4_unlock_group(sb
, entry
->efd_group
);
2832 kmem_cache_free(ext4_free_data_cachep
, entry
);
2833 ext4_mb_unload_buddy(&e4b
);
2835 mb_debug(1, "freed %u blocks in %u structures\n", count
, count2
);
2838 int __init
ext4_init_mballoc(void)
2840 ext4_pspace_cachep
= KMEM_CACHE(ext4_prealloc_space
,
2841 SLAB_RECLAIM_ACCOUNT
);
2842 if (ext4_pspace_cachep
== NULL
)
2845 ext4_ac_cachep
= KMEM_CACHE(ext4_allocation_context
,
2846 SLAB_RECLAIM_ACCOUNT
);
2847 if (ext4_ac_cachep
== NULL
) {
2848 kmem_cache_destroy(ext4_pspace_cachep
);
2852 ext4_free_data_cachep
= KMEM_CACHE(ext4_free_data
,
2853 SLAB_RECLAIM_ACCOUNT
);
2854 if (ext4_free_data_cachep
== NULL
) {
2855 kmem_cache_destroy(ext4_pspace_cachep
);
2856 kmem_cache_destroy(ext4_ac_cachep
);
2862 void ext4_exit_mballoc(void)
2865 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2866 * before destroying the slab cache.
2869 kmem_cache_destroy(ext4_pspace_cachep
);
2870 kmem_cache_destroy(ext4_ac_cachep
);
2871 kmem_cache_destroy(ext4_free_data_cachep
);
2872 ext4_groupinfo_destroy_slabs();
2877 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2878 * Returns 0 if success or error code
2880 static noinline_for_stack
int
2881 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2882 handle_t
*handle
, unsigned int reserv_clstrs
)
2884 struct buffer_head
*bitmap_bh
= NULL
;
2885 struct ext4_group_desc
*gdp
;
2886 struct buffer_head
*gdp_bh
;
2887 struct ext4_sb_info
*sbi
;
2888 struct super_block
*sb
;
2892 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2893 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2899 bitmap_bh
= ext4_read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2903 BUFFER_TRACE(bitmap_bh
, "getting write access");
2904 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2909 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2913 ext4_debug("using block group %u(%d)\n", ac
->ac_b_ex
.fe_group
,
2914 ext4_free_group_clusters(sb
, gdp
));
2916 BUFFER_TRACE(gdp_bh
, "get_write_access");
2917 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2921 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
2923 len
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
2924 if (!ext4_data_block_valid(sbi
, block
, len
)) {
2925 ext4_error(sb
, "Allocating blocks %llu-%llu which overlap "
2926 "fs metadata", block
, block
+len
);
2927 /* File system mounted not to panic on error
2928 * Fix the bitmap and repeat the block allocation
2929 * We leak some of the blocks here.
2931 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2932 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2933 ac
->ac_b_ex
.fe_len
);
2934 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2935 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2941 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2942 #ifdef AGGRESSIVE_CHECK
2945 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2946 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2947 bitmap_bh
->b_data
));
2951 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2952 ac
->ac_b_ex
.fe_len
);
2953 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2954 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2955 ext4_free_group_clusters_set(sb
, gdp
,
2956 ext4_free_clusters_after_init(sb
,
2957 ac
->ac_b_ex
.fe_group
, gdp
));
2959 len
= ext4_free_group_clusters(sb
, gdp
) - ac
->ac_b_ex
.fe_len
;
2960 ext4_free_group_clusters_set(sb
, gdp
, len
);
2961 ext4_block_bitmap_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
, bitmap_bh
);
2962 ext4_group_desc_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
);
2964 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2965 percpu_counter_sub(&sbi
->s_freeclusters_counter
, ac
->ac_b_ex
.fe_len
);
2967 * Now reduce the dirty block count also. Should not go negative
2969 if (!(ac
->ac_flags
& EXT4_MB_DELALLOC_RESERVED
))
2970 /* release all the reserved blocks if non delalloc */
2971 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
2974 if (sbi
->s_log_groups_per_flex
) {
2975 ext4_group_t flex_group
= ext4_flex_group(sbi
,
2976 ac
->ac_b_ex
.fe_group
);
2977 atomic64_sub(ac
->ac_b_ex
.fe_len
,
2978 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
2981 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2984 err
= ext4_handle_dirty_metadata(handle
, NULL
, gdp_bh
);
2992 * here we normalize request for locality group
2993 * Group request are normalized to s_mb_group_prealloc, which goes to
2994 * s_strip if we set the same via mount option.
2995 * s_mb_group_prealloc can be configured via
2996 * /sys/fs/ext4/<partition>/mb_group_prealloc
2998 * XXX: should we try to preallocate more than the group has now?
3000 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
3002 struct super_block
*sb
= ac
->ac_sb
;
3003 struct ext4_locality_group
*lg
= ac
->ac_lg
;
3006 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
3007 mb_debug(1, "#%u: goal %u blocks for locality group\n",
3008 current
->pid
, ac
->ac_g_ex
.fe_len
);
3012 * Normalization means making request better in terms of
3013 * size and alignment
3015 static noinline_for_stack
void
3016 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
3017 struct ext4_allocation_request
*ar
)
3019 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3022 loff_t size
, start_off
;
3023 loff_t orig_size __maybe_unused
;
3025 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3026 struct ext4_prealloc_space
*pa
;
3028 /* do normalize only data requests, metadata requests
3029 do not need preallocation */
3030 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3033 /* sometime caller may want exact blocks */
3034 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3037 /* caller may indicate that preallocation isn't
3038 * required (it's a tail, for example) */
3039 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
3042 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
3043 ext4_mb_normalize_group_request(ac
);
3047 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3049 /* first, let's learn actual file size
3050 * given current request is allocated */
3051 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
3052 size
= size
<< bsbits
;
3053 if (size
< i_size_read(ac
->ac_inode
))
3054 size
= i_size_read(ac
->ac_inode
);
3057 /* max size of free chunks */
3060 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3061 (req <= (size) || max <= (chunk_size))
3063 /* first, try to predict filesize */
3064 /* XXX: should this table be tunable? */
3066 if (size
<= 16 * 1024) {
3068 } else if (size
<= 32 * 1024) {
3070 } else if (size
<= 64 * 1024) {
3072 } else if (size
<= 128 * 1024) {
3074 } else if (size
<= 256 * 1024) {
3076 } else if (size
<= 512 * 1024) {
3078 } else if (size
<= 1024 * 1024) {
3080 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
3081 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3082 (21 - bsbits
)) << 21;
3083 size
= 2 * 1024 * 1024;
3084 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
3085 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3086 (22 - bsbits
)) << 22;
3087 size
= 4 * 1024 * 1024;
3088 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
3089 (8<<20)>>bsbits
, max
, 8 * 1024)) {
3090 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3091 (23 - bsbits
)) << 23;
3092 size
= 8 * 1024 * 1024;
3094 start_off
= (loff_t
) ac
->ac_o_ex
.fe_logical
<< bsbits
;
3095 size
= (loff_t
) EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3096 ac
->ac_o_ex
.fe_len
) << bsbits
;
3098 size
= size
>> bsbits
;
3099 start
= start_off
>> bsbits
;
3101 /* don't cover already allocated blocks in selected range */
3102 if (ar
->pleft
&& start
<= ar
->lleft
) {
3103 size
-= ar
->lleft
+ 1 - start
;
3104 start
= ar
->lleft
+ 1;
3106 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
3107 size
-= start
+ size
- ar
->lright
;
3111 /* check we don't cross already preallocated blocks */
3113 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3118 spin_lock(&pa
->pa_lock
);
3119 if (pa
->pa_deleted
) {
3120 spin_unlock(&pa
->pa_lock
);
3124 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3127 /* PA must not overlap original request */
3128 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
3129 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
3131 /* skip PAs this normalized request doesn't overlap with */
3132 if (pa
->pa_lstart
>= end
|| pa_end
<= start
) {
3133 spin_unlock(&pa
->pa_lock
);
3136 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
3138 /* adjust start or end to be adjacent to this pa */
3139 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
3140 BUG_ON(pa_end
< start
);
3142 } else if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
3143 BUG_ON(pa
->pa_lstart
> end
);
3144 end
= pa
->pa_lstart
;
3146 spin_unlock(&pa
->pa_lock
);
3151 /* XXX: extra loop to check we really don't overlap preallocations */
3153 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3156 spin_lock(&pa
->pa_lock
);
3157 if (pa
->pa_deleted
== 0) {
3158 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3160 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3162 spin_unlock(&pa
->pa_lock
);
3166 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3167 start
> ac
->ac_o_ex
.fe_logical
) {
3168 ext4_msg(ac
->ac_sb
, KERN_ERR
,
3169 "start %lu, size %lu, fe_logical %lu",
3170 (unsigned long) start
, (unsigned long) size
,
3171 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3174 BUG_ON(size
<= 0 || size
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3176 /* now prepare goal request */
3178 /* XXX: is it better to align blocks WRT to logical
3179 * placement or satisfy big request as is */
3180 ac
->ac_g_ex
.fe_logical
= start
;
3181 ac
->ac_g_ex
.fe_len
= EXT4_NUM_B2C(sbi
, size
);
3183 /* define goal start in order to merge */
3184 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3185 /* merge to the right */
3186 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3187 &ac
->ac_f_ex
.fe_group
,
3188 &ac
->ac_f_ex
.fe_start
);
3189 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3191 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3192 /* merge to the left */
3193 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3194 &ac
->ac_f_ex
.fe_group
,
3195 &ac
->ac_f_ex
.fe_start
);
3196 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3199 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3200 (unsigned) orig_size
, (unsigned) start
);
3203 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3205 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3207 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3208 atomic_inc(&sbi
->s_bal_reqs
);
3209 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3210 if (ac
->ac_b_ex
.fe_len
>= ac
->ac_o_ex
.fe_len
)
3211 atomic_inc(&sbi
->s_bal_success
);
3212 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3213 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3214 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3215 atomic_inc(&sbi
->s_bal_goals
);
3216 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3217 atomic_inc(&sbi
->s_bal_breaks
);
3220 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
)
3221 trace_ext4_mballoc_alloc(ac
);
3223 trace_ext4_mballoc_prealloc(ac
);
3227 * Called on failure; free up any blocks from the inode PA for this
3228 * context. We don't need this for MB_GROUP_PA because we only change
3229 * pa_free in ext4_mb_release_context(), but on failure, we've already
3230 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3232 static void ext4_discard_allocated_blocks(struct ext4_allocation_context
*ac
)
3234 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
3235 struct ext4_buddy e4b
;
3239 if (ac
->ac_f_ex
.fe_len
== 0)
3241 err
= ext4_mb_load_buddy(ac
->ac_sb
, ac
->ac_f_ex
.fe_group
, &e4b
);
3244 * This should never happen since we pin the
3245 * pages in the ext4_allocation_context so
3246 * ext4_mb_load_buddy() should never fail.
3248 WARN(1, "mb_load_buddy failed (%d)", err
);
3251 ext4_lock_group(ac
->ac_sb
, ac
->ac_f_ex
.fe_group
);
3252 mb_free_blocks(ac
->ac_inode
, &e4b
, ac
->ac_f_ex
.fe_start
,
3253 ac
->ac_f_ex
.fe_len
);
3254 ext4_unlock_group(ac
->ac_sb
, ac
->ac_f_ex
.fe_group
);
3255 ext4_mb_unload_buddy(&e4b
);
3258 if (pa
->pa_type
== MB_INODE_PA
)
3259 pa
->pa_free
+= ac
->ac_b_ex
.fe_len
;
3263 * use blocks preallocated to inode
3265 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3266 struct ext4_prealloc_space
*pa
)
3268 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3273 /* found preallocated blocks, use them */
3274 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3275 end
= min(pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
),
3276 start
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
));
3277 len
= EXT4_NUM_B2C(sbi
, end
- start
);
3278 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3279 &ac
->ac_b_ex
.fe_start
);
3280 ac
->ac_b_ex
.fe_len
= len
;
3281 ac
->ac_status
= AC_STATUS_FOUND
;
3284 BUG_ON(start
< pa
->pa_pstart
);
3285 BUG_ON(end
> pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
));
3286 BUG_ON(pa
->pa_free
< len
);
3289 mb_debug(1, "use %llu/%u from inode pa %p\n", start
, len
, pa
);
3293 * use blocks preallocated to locality group
3295 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3296 struct ext4_prealloc_space
*pa
)
3298 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3300 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3301 &ac
->ac_b_ex
.fe_group
,
3302 &ac
->ac_b_ex
.fe_start
);
3303 ac
->ac_b_ex
.fe_len
= len
;
3304 ac
->ac_status
= AC_STATUS_FOUND
;
3307 /* we don't correct pa_pstart or pa_plen here to avoid
3308 * possible race when the group is being loaded concurrently
3309 * instead we correct pa later, after blocks are marked
3310 * in on-disk bitmap -- see ext4_mb_release_context()
3311 * Other CPUs are prevented from allocating from this pa by lg_mutex
3313 mb_debug(1, "use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3317 * Return the prealloc space that have minimal distance
3318 * from the goal block. @cpa is the prealloc
3319 * space that is having currently known minimal distance
3320 * from the goal block.
3322 static struct ext4_prealloc_space
*
3323 ext4_mb_check_group_pa(ext4_fsblk_t goal_block
,
3324 struct ext4_prealloc_space
*pa
,
3325 struct ext4_prealloc_space
*cpa
)
3327 ext4_fsblk_t cur_distance
, new_distance
;
3330 atomic_inc(&pa
->pa_count
);
3333 cur_distance
= abs(goal_block
- cpa
->pa_pstart
);
3334 new_distance
= abs(goal_block
- pa
->pa_pstart
);
3336 if (cur_distance
<= new_distance
)
3339 /* drop the previous reference */
3340 atomic_dec(&cpa
->pa_count
);
3341 atomic_inc(&pa
->pa_count
);
3346 * search goal blocks in preallocated space
3348 static noinline_for_stack
int
3349 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3351 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3353 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3354 struct ext4_locality_group
*lg
;
3355 struct ext4_prealloc_space
*pa
, *cpa
= NULL
;
3356 ext4_fsblk_t goal_block
;
3358 /* only data can be preallocated */
3359 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3362 /* first, try per-file preallocation */
3364 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3366 /* all fields in this condition don't change,
3367 * so we can skip locking for them */
3368 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3369 ac
->ac_o_ex
.fe_logical
>= (pa
->pa_lstart
+
3370 EXT4_C2B(sbi
, pa
->pa_len
)))
3373 /* non-extent files can't have physical blocks past 2^32 */
3374 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)) &&
3375 (pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
) >
3376 EXT4_MAX_BLOCK_FILE_PHYS
))
3379 /* found preallocated blocks, use them */
3380 spin_lock(&pa
->pa_lock
);
3381 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3382 atomic_inc(&pa
->pa_count
);
3383 ext4_mb_use_inode_pa(ac
, pa
);
3384 spin_unlock(&pa
->pa_lock
);
3385 ac
->ac_criteria
= 10;
3389 spin_unlock(&pa
->pa_lock
);
3393 /* can we use group allocation? */
3394 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3397 /* inode may have no locality group for some reason */
3401 order
= fls(ac
->ac_o_ex
.fe_len
) - 1;
3402 if (order
> PREALLOC_TB_SIZE
- 1)
3403 /* The max size of hash table is PREALLOC_TB_SIZE */
3404 order
= PREALLOC_TB_SIZE
- 1;
3406 goal_block
= ext4_grp_offs_to_block(ac
->ac_sb
, &ac
->ac_g_ex
);
3408 * search for the prealloc space that is having
3409 * minimal distance from the goal block.
3411 for (i
= order
; i
< PREALLOC_TB_SIZE
; i
++) {
3413 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[i
],
3415 spin_lock(&pa
->pa_lock
);
3416 if (pa
->pa_deleted
== 0 &&
3417 pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3419 cpa
= ext4_mb_check_group_pa(goal_block
,
3422 spin_unlock(&pa
->pa_lock
);
3427 ext4_mb_use_group_pa(ac
, cpa
);
3428 ac
->ac_criteria
= 20;
3435 * the function goes through all block freed in the group
3436 * but not yet committed and marks them used in in-core bitmap.
3437 * buddy must be generated from this bitmap
3438 * Need to be called with the ext4 group lock held
3440 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
3444 struct ext4_group_info
*grp
;
3445 struct ext4_free_data
*entry
;
3447 grp
= ext4_get_group_info(sb
, group
);
3448 n
= rb_first(&(grp
->bb_free_root
));
3451 entry
= rb_entry(n
, struct ext4_free_data
, efd_node
);
3452 ext4_set_bits(bitmap
, entry
->efd_start_cluster
, entry
->efd_count
);
3459 * the function goes through all preallocation in this group and marks them
3460 * used in in-core bitmap. buddy must be generated from this bitmap
3461 * Need to be called with ext4 group lock held
3463 static noinline_for_stack
3464 void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3467 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3468 struct ext4_prealloc_space
*pa
;
3469 struct list_head
*cur
;
3470 ext4_group_t groupnr
;
3471 ext4_grpblk_t start
;
3472 int preallocated
= 0;
3475 /* all form of preallocation discards first load group,
3476 * so the only competing code is preallocation use.
3477 * we don't need any locking here
3478 * notice we do NOT ignore preallocations with pa_deleted
3479 * otherwise we could leave used blocks available for
3480 * allocation in buddy when concurrent ext4_mb_put_pa()
3481 * is dropping preallocation
3483 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3484 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3485 spin_lock(&pa
->pa_lock
);
3486 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3489 spin_unlock(&pa
->pa_lock
);
3490 if (unlikely(len
== 0))
3492 BUG_ON(groupnr
!= group
);
3493 ext4_set_bits(bitmap
, start
, len
);
3494 preallocated
+= len
;
3496 mb_debug(1, "prellocated %u for group %u\n", preallocated
, group
);
3499 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3501 struct ext4_prealloc_space
*pa
;
3502 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3504 BUG_ON(atomic_read(&pa
->pa_count
));
3505 BUG_ON(pa
->pa_deleted
== 0);
3506 kmem_cache_free(ext4_pspace_cachep
, pa
);
3510 * drops a reference to preallocated space descriptor
3511 * if this was the last reference and the space is consumed
3513 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3514 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3517 ext4_fsblk_t grp_blk
;
3519 /* in this short window concurrent discard can set pa_deleted */
3520 spin_lock(&pa
->pa_lock
);
3521 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0) {
3522 spin_unlock(&pa
->pa_lock
);
3526 if (pa
->pa_deleted
== 1) {
3527 spin_unlock(&pa
->pa_lock
);
3532 spin_unlock(&pa
->pa_lock
);
3534 grp_blk
= pa
->pa_pstart
;
3536 * If doing group-based preallocation, pa_pstart may be in the
3537 * next group when pa is used up
3539 if (pa
->pa_type
== MB_GROUP_PA
)
3542 grp
= ext4_get_group_number(sb
, grp_blk
);
3547 * P1 (buddy init) P2 (regular allocation)
3548 * find block B in PA
3549 * copy on-disk bitmap to buddy
3550 * mark B in on-disk bitmap
3551 * drop PA from group
3552 * mark all PAs in buddy
3554 * thus, P1 initializes buddy with B available. to prevent this
3555 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3558 ext4_lock_group(sb
, grp
);
3559 list_del(&pa
->pa_group_list
);
3560 ext4_unlock_group(sb
, grp
);
3562 spin_lock(pa
->pa_obj_lock
);
3563 list_del_rcu(&pa
->pa_inode_list
);
3564 spin_unlock(pa
->pa_obj_lock
);
3566 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3570 * creates new preallocated space for given inode
3572 static noinline_for_stack
int
3573 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3575 struct super_block
*sb
= ac
->ac_sb
;
3576 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3577 struct ext4_prealloc_space
*pa
;
3578 struct ext4_group_info
*grp
;
3579 struct ext4_inode_info
*ei
;
3581 /* preallocate only when found space is larger then requested */
3582 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3583 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3584 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3586 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3590 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3596 /* we can't allocate as much as normalizer wants.
3597 * so, found space must get proper lstart
3598 * to cover original request */
3599 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3600 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3602 /* we're limited by original request in that
3603 * logical block must be covered any way
3604 * winl is window we can move our chunk within */
3605 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3607 /* also, we should cover whole original request */
3608 wins
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
);
3610 /* the smallest one defines real window */
3611 win
= min(winl
, wins
);
3613 offs
= ac
->ac_o_ex
.fe_logical
%
3614 EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
3615 if (offs
&& offs
< win
)
3618 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
-
3619 EXT4_NUM_B2C(sbi
, win
);
3620 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3621 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3624 /* preallocation can change ac_b_ex, thus we store actually
3625 * allocated blocks for history */
3626 ac
->ac_f_ex
= ac
->ac_b_ex
;
3628 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3629 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3630 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3631 pa
->pa_free
= pa
->pa_len
;
3632 atomic_set(&pa
->pa_count
, 1);
3633 spin_lock_init(&pa
->pa_lock
);
3634 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3635 INIT_LIST_HEAD(&pa
->pa_group_list
);
3637 pa
->pa_type
= MB_INODE_PA
;
3639 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa
,
3640 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3641 trace_ext4_mb_new_inode_pa(ac
, pa
);
3643 ext4_mb_use_inode_pa(ac
, pa
);
3644 atomic_add(pa
->pa_free
, &sbi
->s_mb_preallocated
);
3646 ei
= EXT4_I(ac
->ac_inode
);
3647 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3649 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3650 pa
->pa_inode
= ac
->ac_inode
;
3652 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3653 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3654 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3656 spin_lock(pa
->pa_obj_lock
);
3657 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3658 spin_unlock(pa
->pa_obj_lock
);
3664 * creates new preallocated space for locality group inodes belongs to
3666 static noinline_for_stack
int
3667 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3669 struct super_block
*sb
= ac
->ac_sb
;
3670 struct ext4_locality_group
*lg
;
3671 struct ext4_prealloc_space
*pa
;
3672 struct ext4_group_info
*grp
;
3674 /* preallocate only when found space is larger then requested */
3675 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3676 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3677 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3679 BUG_ON(ext4_pspace_cachep
== NULL
);
3680 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3684 /* preallocation can change ac_b_ex, thus we store actually
3685 * allocated blocks for history */
3686 ac
->ac_f_ex
= ac
->ac_b_ex
;
3688 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3689 pa
->pa_lstart
= pa
->pa_pstart
;
3690 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3691 pa
->pa_free
= pa
->pa_len
;
3692 atomic_set(&pa
->pa_count
, 1);
3693 spin_lock_init(&pa
->pa_lock
);
3694 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3695 INIT_LIST_HEAD(&pa
->pa_group_list
);
3697 pa
->pa_type
= MB_GROUP_PA
;
3699 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa
,
3700 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3701 trace_ext4_mb_new_group_pa(ac
, pa
);
3703 ext4_mb_use_group_pa(ac
, pa
);
3704 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3706 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3710 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3711 pa
->pa_inode
= NULL
;
3713 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3714 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3715 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3718 * We will later add the new pa to the right bucket
3719 * after updating the pa_free in ext4_mb_release_context
3724 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3728 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3729 err
= ext4_mb_new_group_pa(ac
);
3731 err
= ext4_mb_new_inode_pa(ac
);
3736 * finds all unused blocks in on-disk bitmap, frees them in
3737 * in-core bitmap and buddy.
3738 * @pa must be unlinked from inode and group lists, so that
3739 * nobody else can find/use it.
3740 * the caller MUST hold group/inode locks.
3741 * TODO: optimize the case when there are no in-core structures yet
3743 static noinline_for_stack
int
3744 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3745 struct ext4_prealloc_space
*pa
)
3747 struct super_block
*sb
= e4b
->bd_sb
;
3748 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3753 unsigned long long grp_blk_start
;
3757 BUG_ON(pa
->pa_deleted
== 0);
3758 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3759 grp_blk_start
= pa
->pa_pstart
- EXT4_C2B(sbi
, bit
);
3760 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3761 end
= bit
+ pa
->pa_len
;
3764 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3767 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3768 mb_debug(1, " free preallocated %u/%u in group %u\n",
3769 (unsigned) ext4_group_first_block_no(sb
, group
) + bit
,
3770 (unsigned) next
- bit
, (unsigned) group
);
3773 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, next
- bit
);
3774 trace_ext4_mb_release_inode_pa(pa
, (grp_blk_start
+
3775 EXT4_C2B(sbi
, bit
)),
3777 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3780 if (free
!= pa
->pa_free
) {
3781 ext4_msg(e4b
->bd_sb
, KERN_CRIT
,
3782 "pa %p: logic %lu, phys. %lu, len %lu",
3783 pa
, (unsigned long) pa
->pa_lstart
,
3784 (unsigned long) pa
->pa_pstart
,
3785 (unsigned long) pa
->pa_len
);
3786 ext4_grp_locked_error(sb
, group
, 0, 0, "free %u, pa_free %u",
3789 * pa is already deleted so we use the value obtained
3790 * from the bitmap and continue.
3793 atomic_add(free
, &sbi
->s_mb_discarded
);
3798 static noinline_for_stack
int
3799 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3800 struct ext4_prealloc_space
*pa
)
3802 struct super_block
*sb
= e4b
->bd_sb
;
3806 trace_ext4_mb_release_group_pa(sb
, pa
);
3807 BUG_ON(pa
->pa_deleted
== 0);
3808 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3809 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3810 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3811 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3812 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, pa
->pa_len
);
3818 * releases all preallocations in given group
3820 * first, we need to decide discard policy:
3821 * - when do we discard
3823 * - how many do we discard
3824 * 1) how many requested
3826 static noinline_for_stack
int
3827 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3828 ext4_group_t group
, int needed
)
3830 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3831 struct buffer_head
*bitmap_bh
= NULL
;
3832 struct ext4_prealloc_space
*pa
, *tmp
;
3833 struct list_head list
;
3834 struct ext4_buddy e4b
;
3839 mb_debug(1, "discard preallocation for group %u\n", group
);
3841 if (list_empty(&grp
->bb_prealloc_list
))
3844 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3845 if (bitmap_bh
== NULL
) {
3846 ext4_error(sb
, "Error reading block bitmap for %u", group
);
3850 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3852 ext4_error(sb
, "Error loading buddy information for %u", group
);
3858 needed
= EXT4_CLUSTERS_PER_GROUP(sb
) + 1;
3860 INIT_LIST_HEAD(&list
);
3862 ext4_lock_group(sb
, group
);
3863 list_for_each_entry_safe(pa
, tmp
,
3864 &grp
->bb_prealloc_list
, pa_group_list
) {
3865 spin_lock(&pa
->pa_lock
);
3866 if (atomic_read(&pa
->pa_count
)) {
3867 spin_unlock(&pa
->pa_lock
);
3871 if (pa
->pa_deleted
) {
3872 spin_unlock(&pa
->pa_lock
);
3876 /* seems this one can be freed ... */
3879 /* we can trust pa_free ... */
3880 free
+= pa
->pa_free
;
3882 spin_unlock(&pa
->pa_lock
);
3884 list_del(&pa
->pa_group_list
);
3885 list_add(&pa
->u
.pa_tmp_list
, &list
);
3888 /* if we still need more blocks and some PAs were used, try again */
3889 if (free
< needed
&& busy
) {
3891 ext4_unlock_group(sb
, group
);
3896 /* found anything to free? */
3897 if (list_empty(&list
)) {
3902 /* now free all selected PAs */
3903 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3905 /* remove from object (inode or locality group) */
3906 spin_lock(pa
->pa_obj_lock
);
3907 list_del_rcu(&pa
->pa_inode_list
);
3908 spin_unlock(pa
->pa_obj_lock
);
3910 if (pa
->pa_type
== MB_GROUP_PA
)
3911 ext4_mb_release_group_pa(&e4b
, pa
);
3913 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3915 list_del(&pa
->u
.pa_tmp_list
);
3916 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3920 ext4_unlock_group(sb
, group
);
3921 ext4_mb_unload_buddy(&e4b
);
3927 * releases all non-used preallocated blocks for given inode
3929 * It's important to discard preallocations under i_data_sem
3930 * We don't want another block to be served from the prealloc
3931 * space when we are discarding the inode prealloc space.
3933 * FIXME!! Make sure it is valid at all the call sites
3935 void ext4_discard_preallocations(struct inode
*inode
)
3937 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3938 struct super_block
*sb
= inode
->i_sb
;
3939 struct buffer_head
*bitmap_bh
= NULL
;
3940 struct ext4_prealloc_space
*pa
, *tmp
;
3941 ext4_group_t group
= 0;
3942 struct list_head list
;
3943 struct ext4_buddy e4b
;
3946 if (!S_ISREG(inode
->i_mode
)) {
3947 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3951 mb_debug(1, "discard preallocation for inode %lu\n", inode
->i_ino
);
3952 trace_ext4_discard_preallocations(inode
);
3954 INIT_LIST_HEAD(&list
);
3957 /* first, collect all pa's in the inode */
3958 spin_lock(&ei
->i_prealloc_lock
);
3959 while (!list_empty(&ei
->i_prealloc_list
)) {
3960 pa
= list_entry(ei
->i_prealloc_list
.next
,
3961 struct ext4_prealloc_space
, pa_inode_list
);
3962 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3963 spin_lock(&pa
->pa_lock
);
3964 if (atomic_read(&pa
->pa_count
)) {
3965 /* this shouldn't happen often - nobody should
3966 * use preallocation while we're discarding it */
3967 spin_unlock(&pa
->pa_lock
);
3968 spin_unlock(&ei
->i_prealloc_lock
);
3969 ext4_msg(sb
, KERN_ERR
,
3970 "uh-oh! used pa while discarding");
3972 schedule_timeout_uninterruptible(HZ
);
3976 if (pa
->pa_deleted
== 0) {
3978 spin_unlock(&pa
->pa_lock
);
3979 list_del_rcu(&pa
->pa_inode_list
);
3980 list_add(&pa
->u
.pa_tmp_list
, &list
);
3984 /* someone is deleting pa right now */
3985 spin_unlock(&pa
->pa_lock
);
3986 spin_unlock(&ei
->i_prealloc_lock
);
3988 /* we have to wait here because pa_deleted
3989 * doesn't mean pa is already unlinked from
3990 * the list. as we might be called from
3991 * ->clear_inode() the inode will get freed
3992 * and concurrent thread which is unlinking
3993 * pa from inode's list may access already
3994 * freed memory, bad-bad-bad */
3996 /* XXX: if this happens too often, we can
3997 * add a flag to force wait only in case
3998 * of ->clear_inode(), but not in case of
3999 * regular truncate */
4000 schedule_timeout_uninterruptible(HZ
);
4003 spin_unlock(&ei
->i_prealloc_lock
);
4005 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
4006 BUG_ON(pa
->pa_type
!= MB_INODE_PA
);
4007 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
4009 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
4011 ext4_error(sb
, "Error loading buddy information for %u",
4016 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
4017 if (bitmap_bh
== NULL
) {
4018 ext4_error(sb
, "Error reading block bitmap for %u",
4020 ext4_mb_unload_buddy(&e4b
);
4024 ext4_lock_group(sb
, group
);
4025 list_del(&pa
->pa_group_list
);
4026 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
4027 ext4_unlock_group(sb
, group
);
4029 ext4_mb_unload_buddy(&e4b
);
4032 list_del(&pa
->u
.pa_tmp_list
);
4033 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4037 #ifdef CONFIG_EXT4_DEBUG
4038 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4040 struct super_block
*sb
= ac
->ac_sb
;
4041 ext4_group_t ngroups
, i
;
4043 if (!ext4_mballoc_debug
||
4044 (EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
))
4047 ext4_msg(ac
->ac_sb
, KERN_ERR
, "Can't allocate:"
4048 " Allocation context details:");
4049 ext4_msg(ac
->ac_sb
, KERN_ERR
, "status %d flags %d",
4050 ac
->ac_status
, ac
->ac_flags
);
4051 ext4_msg(ac
->ac_sb
, KERN_ERR
, "orig %lu/%lu/%lu@%lu, "
4052 "goal %lu/%lu/%lu@%lu, "
4053 "best %lu/%lu/%lu@%lu cr %d",
4054 (unsigned long)ac
->ac_o_ex
.fe_group
,
4055 (unsigned long)ac
->ac_o_ex
.fe_start
,
4056 (unsigned long)ac
->ac_o_ex
.fe_len
,
4057 (unsigned long)ac
->ac_o_ex
.fe_logical
,
4058 (unsigned long)ac
->ac_g_ex
.fe_group
,
4059 (unsigned long)ac
->ac_g_ex
.fe_start
,
4060 (unsigned long)ac
->ac_g_ex
.fe_len
,
4061 (unsigned long)ac
->ac_g_ex
.fe_logical
,
4062 (unsigned long)ac
->ac_b_ex
.fe_group
,
4063 (unsigned long)ac
->ac_b_ex
.fe_start
,
4064 (unsigned long)ac
->ac_b_ex
.fe_len
,
4065 (unsigned long)ac
->ac_b_ex
.fe_logical
,
4066 (int)ac
->ac_criteria
);
4067 ext4_msg(ac
->ac_sb
, KERN_ERR
, "%d found", ac
->ac_found
);
4068 ext4_msg(ac
->ac_sb
, KERN_ERR
, "groups: ");
4069 ngroups
= ext4_get_groups_count(sb
);
4070 for (i
= 0; i
< ngroups
; i
++) {
4071 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
4072 struct ext4_prealloc_space
*pa
;
4073 ext4_grpblk_t start
;
4074 struct list_head
*cur
;
4075 ext4_lock_group(sb
, i
);
4076 list_for_each(cur
, &grp
->bb_prealloc_list
) {
4077 pa
= list_entry(cur
, struct ext4_prealloc_space
,
4079 spin_lock(&pa
->pa_lock
);
4080 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
4082 spin_unlock(&pa
->pa_lock
);
4083 printk(KERN_ERR
"PA:%u:%d:%u \n", i
,
4086 ext4_unlock_group(sb
, i
);
4088 if (grp
->bb_free
== 0)
4090 printk(KERN_ERR
"%u: %d/%d \n",
4091 i
, grp
->bb_free
, grp
->bb_fragments
);
4093 printk(KERN_ERR
"\n");
4096 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4103 * We use locality group preallocation for small size file. The size of the
4104 * file is determined by the current size or the resulting size after
4105 * allocation which ever is larger
4107 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4109 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
4111 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4112 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
4115 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
4118 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
4121 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
4122 isize
= (i_size_read(ac
->ac_inode
) + ac
->ac_sb
->s_blocksize
- 1)
4125 if ((size
== isize
) &&
4126 !ext4_fs_is_busy(sbi
) &&
4127 (atomic_read(&ac
->ac_inode
->i_writecount
) == 0)) {
4128 ac
->ac_flags
|= EXT4_MB_HINT_NOPREALLOC
;
4132 if (sbi
->s_mb_group_prealloc
<= 0) {
4133 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4137 /* don't use group allocation for large files */
4138 size
= max(size
, isize
);
4139 if (size
> sbi
->s_mb_stream_request
) {
4140 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4144 BUG_ON(ac
->ac_lg
!= NULL
);
4146 * locality group prealloc space are per cpu. The reason for having
4147 * per cpu locality group is to reduce the contention between block
4148 * request from multiple CPUs.
4150 ac
->ac_lg
= raw_cpu_ptr(sbi
->s_locality_groups
);
4152 /* we're going to use group allocation */
4153 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
4155 /* serialize all allocations in the group */
4156 mutex_lock(&ac
->ac_lg
->lg_mutex
);
4159 static noinline_for_stack
int
4160 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
4161 struct ext4_allocation_request
*ar
)
4163 struct super_block
*sb
= ar
->inode
->i_sb
;
4164 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4165 struct ext4_super_block
*es
= sbi
->s_es
;
4169 ext4_grpblk_t block
;
4171 /* we can't allocate > group size */
4174 /* just a dirty hack to filter too big requests */
4175 if (len
>= EXT4_CLUSTERS_PER_GROUP(sb
))
4176 len
= EXT4_CLUSTERS_PER_GROUP(sb
);
4178 /* start searching from the goal */
4180 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
4181 goal
>= ext4_blocks_count(es
))
4182 goal
= le32_to_cpu(es
->s_first_data_block
);
4183 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
4185 /* set up allocation goals */
4186 ac
->ac_b_ex
.fe_logical
= EXT4_LBLK_CMASK(sbi
, ar
->logical
);
4187 ac
->ac_status
= AC_STATUS_CONTINUE
;
4189 ac
->ac_inode
= ar
->inode
;
4190 ac
->ac_o_ex
.fe_logical
= ac
->ac_b_ex
.fe_logical
;
4191 ac
->ac_o_ex
.fe_group
= group
;
4192 ac
->ac_o_ex
.fe_start
= block
;
4193 ac
->ac_o_ex
.fe_len
= len
;
4194 ac
->ac_g_ex
= ac
->ac_o_ex
;
4195 ac
->ac_flags
= ar
->flags
;
4197 /* we have to define context: we'll we work with a file or
4198 * locality group. this is a policy, actually */
4199 ext4_mb_group_or_file(ac
);
4201 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4202 "left: %u/%u, right %u/%u to %swritable\n",
4203 (unsigned) ar
->len
, (unsigned) ar
->logical
,
4204 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
4205 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
4206 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
4207 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
4212 static noinline_for_stack
void
4213 ext4_mb_discard_lg_preallocations(struct super_block
*sb
,
4214 struct ext4_locality_group
*lg
,
4215 int order
, int total_entries
)
4217 ext4_group_t group
= 0;
4218 struct ext4_buddy e4b
;
4219 struct list_head discard_list
;
4220 struct ext4_prealloc_space
*pa
, *tmp
;
4222 mb_debug(1, "discard locality group preallocation\n");
4224 INIT_LIST_HEAD(&discard_list
);
4226 spin_lock(&lg
->lg_prealloc_lock
);
4227 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[order
],
4229 spin_lock(&pa
->pa_lock
);
4230 if (atomic_read(&pa
->pa_count
)) {
4232 * This is the pa that we just used
4233 * for block allocation. So don't
4236 spin_unlock(&pa
->pa_lock
);
4239 if (pa
->pa_deleted
) {
4240 spin_unlock(&pa
->pa_lock
);
4243 /* only lg prealloc space */
4244 BUG_ON(pa
->pa_type
!= MB_GROUP_PA
);
4246 /* seems this one can be freed ... */
4248 spin_unlock(&pa
->pa_lock
);
4250 list_del_rcu(&pa
->pa_inode_list
);
4251 list_add(&pa
->u
.pa_tmp_list
, &discard_list
);
4254 if (total_entries
<= 5) {
4256 * we want to keep only 5 entries
4257 * allowing it to grow to 8. This
4258 * mak sure we don't call discard
4259 * soon for this list.
4264 spin_unlock(&lg
->lg_prealloc_lock
);
4266 list_for_each_entry_safe(pa
, tmp
, &discard_list
, u
.pa_tmp_list
) {
4268 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
4269 if (ext4_mb_load_buddy(sb
, group
, &e4b
)) {
4270 ext4_error(sb
, "Error loading buddy information for %u",
4274 ext4_lock_group(sb
, group
);
4275 list_del(&pa
->pa_group_list
);
4276 ext4_mb_release_group_pa(&e4b
, pa
);
4277 ext4_unlock_group(sb
, group
);
4279 ext4_mb_unload_buddy(&e4b
);
4280 list_del(&pa
->u
.pa_tmp_list
);
4281 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4286 * We have incremented pa_count. So it cannot be freed at this
4287 * point. Also we hold lg_mutex. So no parallel allocation is
4288 * possible from this lg. That means pa_free cannot be updated.
4290 * A parallel ext4_mb_discard_group_preallocations is possible.
4291 * which can cause the lg_prealloc_list to be updated.
4294 static void ext4_mb_add_n_trim(struct ext4_allocation_context
*ac
)
4296 int order
, added
= 0, lg_prealloc_count
= 1;
4297 struct super_block
*sb
= ac
->ac_sb
;
4298 struct ext4_locality_group
*lg
= ac
->ac_lg
;
4299 struct ext4_prealloc_space
*tmp_pa
, *pa
= ac
->ac_pa
;
4301 order
= fls(pa
->pa_free
) - 1;
4302 if (order
> PREALLOC_TB_SIZE
- 1)
4303 /* The max size of hash table is PREALLOC_TB_SIZE */
4304 order
= PREALLOC_TB_SIZE
- 1;
4305 /* Add the prealloc space to lg */
4306 spin_lock(&lg
->lg_prealloc_lock
);
4307 list_for_each_entry_rcu(tmp_pa
, &lg
->lg_prealloc_list
[order
],
4309 spin_lock(&tmp_pa
->pa_lock
);
4310 if (tmp_pa
->pa_deleted
) {
4311 spin_unlock(&tmp_pa
->pa_lock
);
4314 if (!added
&& pa
->pa_free
< tmp_pa
->pa_free
) {
4315 /* Add to the tail of the previous entry */
4316 list_add_tail_rcu(&pa
->pa_inode_list
,
4317 &tmp_pa
->pa_inode_list
);
4320 * we want to count the total
4321 * number of entries in the list
4324 spin_unlock(&tmp_pa
->pa_lock
);
4325 lg_prealloc_count
++;
4328 list_add_tail_rcu(&pa
->pa_inode_list
,
4329 &lg
->lg_prealloc_list
[order
]);
4330 spin_unlock(&lg
->lg_prealloc_lock
);
4332 /* Now trim the list to be not more than 8 elements */
4333 if (lg_prealloc_count
> 8) {
4334 ext4_mb_discard_lg_preallocations(sb
, lg
,
4335 order
, lg_prealloc_count
);
4342 * release all resource we used in allocation
4344 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
4346 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4347 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
4349 if (pa
->pa_type
== MB_GROUP_PA
) {
4350 /* see comment in ext4_mb_use_group_pa() */
4351 spin_lock(&pa
->pa_lock
);
4352 pa
->pa_pstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4353 pa
->pa_lstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4354 pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
4355 pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
4356 spin_unlock(&pa
->pa_lock
);
4361 * We want to add the pa to the right bucket.
4362 * Remove it from the list and while adding
4363 * make sure the list to which we are adding
4366 if ((pa
->pa_type
== MB_GROUP_PA
) && likely(pa
->pa_free
)) {
4367 spin_lock(pa
->pa_obj_lock
);
4368 list_del_rcu(&pa
->pa_inode_list
);
4369 spin_unlock(pa
->pa_obj_lock
);
4370 ext4_mb_add_n_trim(ac
);
4372 ext4_mb_put_pa(ac
, ac
->ac_sb
, pa
);
4374 if (ac
->ac_bitmap_page
)
4375 page_cache_release(ac
->ac_bitmap_page
);
4376 if (ac
->ac_buddy_page
)
4377 page_cache_release(ac
->ac_buddy_page
);
4378 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
4379 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
4380 ext4_mb_collect_stats(ac
);
4384 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
4386 ext4_group_t i
, ngroups
= ext4_get_groups_count(sb
);
4390 trace_ext4_mb_discard_preallocations(sb
, needed
);
4391 for (i
= 0; i
< ngroups
&& needed
> 0; i
++) {
4392 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4401 * Main entry point into mballoc to allocate blocks
4402 * it tries to use preallocation first, then falls back
4403 * to usual allocation
4405 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4406 struct ext4_allocation_request
*ar
, int *errp
)
4409 struct ext4_allocation_context
*ac
= NULL
;
4410 struct ext4_sb_info
*sbi
;
4411 struct super_block
*sb
;
4412 ext4_fsblk_t block
= 0;
4413 unsigned int inquota
= 0;
4414 unsigned int reserv_clstrs
= 0;
4417 sb
= ar
->inode
->i_sb
;
4420 trace_ext4_request_blocks(ar
);
4422 /* Allow to use superuser reservation for quota file */
4423 if (IS_NOQUOTA(ar
->inode
))
4424 ar
->flags
|= EXT4_MB_USE_ROOT_BLOCKS
;
4426 if ((ar
->flags
& EXT4_MB_DELALLOC_RESERVED
) == 0) {
4427 /* Without delayed allocation we need to verify
4428 * there is enough free blocks to do block allocation
4429 * and verify allocation doesn't exceed the quota limits.
4432 ext4_claim_free_clusters(sbi
, ar
->len
, ar
->flags
)) {
4434 /* let others to free the space */
4436 ar
->len
= ar
->len
>> 1;
4442 reserv_clstrs
= ar
->len
;
4443 if (ar
->flags
& EXT4_MB_USE_ROOT_BLOCKS
) {
4444 dquot_alloc_block_nofail(ar
->inode
,
4445 EXT4_C2B(sbi
, ar
->len
));
4448 dquot_alloc_block(ar
->inode
,
4449 EXT4_C2B(sbi
, ar
->len
))) {
4451 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4462 ac
= kmem_cache_zalloc(ext4_ac_cachep
, GFP_NOFS
);
4469 *errp
= ext4_mb_initialize_context(ac
, ar
);
4475 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4476 if (!ext4_mb_use_preallocated(ac
)) {
4477 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4478 ext4_mb_normalize_request(ac
, ar
);
4480 /* allocate space in core */
4481 *errp
= ext4_mb_regular_allocator(ac
);
4483 goto discard_and_exit
;
4485 /* as we've just preallocated more space than
4486 * user requested originally, we store allocated
4487 * space in a special descriptor */
4488 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4489 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4490 *errp
= ext4_mb_new_preallocation(ac
);
4493 ext4_discard_allocated_blocks(ac
);
4497 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4498 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
, reserv_clstrs
);
4499 if (*errp
== -EAGAIN
) {
4501 * drop the reference that we took
4502 * in ext4_mb_use_best_found
4504 ext4_mb_release_context(ac
);
4505 ac
->ac_b_ex
.fe_group
= 0;
4506 ac
->ac_b_ex
.fe_start
= 0;
4507 ac
->ac_b_ex
.fe_len
= 0;
4508 ac
->ac_status
= AC_STATUS_CONTINUE
;
4511 ext4_discard_allocated_blocks(ac
);
4514 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4515 ar
->len
= ac
->ac_b_ex
.fe_len
;
4518 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4526 ac
->ac_b_ex
.fe_len
= 0;
4528 ext4_mb_show_ac(ac
);
4530 ext4_mb_release_context(ac
);
4533 kmem_cache_free(ext4_ac_cachep
, ac
);
4534 if (inquota
&& ar
->len
< inquota
)
4535 dquot_free_block(ar
->inode
, EXT4_C2B(sbi
, inquota
- ar
->len
));
4537 if ((ar
->flags
& EXT4_MB_DELALLOC_RESERVED
) == 0)
4538 /* release all the reserved blocks if non delalloc */
4539 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
4543 trace_ext4_allocate_blocks(ar
, (unsigned long long)block
);
4549 * We can merge two free data extents only if the physical blocks
4550 * are contiguous, AND the extents were freed by the same transaction,
4551 * AND the blocks are associated with the same group.
4553 static int can_merge(struct ext4_free_data
*entry1
,
4554 struct ext4_free_data
*entry2
)
4556 if ((entry1
->efd_tid
== entry2
->efd_tid
) &&
4557 (entry1
->efd_group
== entry2
->efd_group
) &&
4558 ((entry1
->efd_start_cluster
+ entry1
->efd_count
) == entry2
->efd_start_cluster
))
4563 static noinline_for_stack
int
4564 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4565 struct ext4_free_data
*new_entry
)
4567 ext4_group_t group
= e4b
->bd_group
;
4568 ext4_grpblk_t cluster
;
4569 struct ext4_free_data
*entry
;
4570 struct ext4_group_info
*db
= e4b
->bd_info
;
4571 struct super_block
*sb
= e4b
->bd_sb
;
4572 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4573 struct rb_node
**n
= &db
->bb_free_root
.rb_node
, *node
;
4574 struct rb_node
*parent
= NULL
, *new_node
;
4576 BUG_ON(!ext4_handle_valid(handle
));
4577 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4578 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4580 new_node
= &new_entry
->efd_node
;
4581 cluster
= new_entry
->efd_start_cluster
;
4584 /* first free block exent. We need to
4585 protect buddy cache from being freed,
4586 * otherwise we'll refresh it from
4587 * on-disk bitmap and lose not-yet-available
4589 page_cache_get(e4b
->bd_buddy_page
);
4590 page_cache_get(e4b
->bd_bitmap_page
);
4594 entry
= rb_entry(parent
, struct ext4_free_data
, efd_node
);
4595 if (cluster
< entry
->efd_start_cluster
)
4597 else if (cluster
>= (entry
->efd_start_cluster
+ entry
->efd_count
))
4598 n
= &(*n
)->rb_right
;
4600 ext4_grp_locked_error(sb
, group
, 0,
4601 ext4_group_first_block_no(sb
, group
) +
4602 EXT4_C2B(sbi
, cluster
),
4603 "Block already on to-be-freed list");
4608 rb_link_node(new_node
, parent
, n
);
4609 rb_insert_color(new_node
, &db
->bb_free_root
);
4611 /* Now try to see the extent can be merged to left and right */
4612 node
= rb_prev(new_node
);
4614 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4615 if (can_merge(entry
, new_entry
) &&
4616 ext4_journal_callback_try_del(handle
, &entry
->efd_jce
)) {
4617 new_entry
->efd_start_cluster
= entry
->efd_start_cluster
;
4618 new_entry
->efd_count
+= entry
->efd_count
;
4619 rb_erase(node
, &(db
->bb_free_root
));
4620 kmem_cache_free(ext4_free_data_cachep
, entry
);
4624 node
= rb_next(new_node
);
4626 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4627 if (can_merge(new_entry
, entry
) &&
4628 ext4_journal_callback_try_del(handle
, &entry
->efd_jce
)) {
4629 new_entry
->efd_count
+= entry
->efd_count
;
4630 rb_erase(node
, &(db
->bb_free_root
));
4631 kmem_cache_free(ext4_free_data_cachep
, entry
);
4634 /* Add the extent to transaction's private list */
4635 ext4_journal_callback_add(handle
, ext4_free_data_callback
,
4636 &new_entry
->efd_jce
);
4641 * ext4_free_blocks() -- Free given blocks and update quota
4642 * @handle: handle for this transaction
4644 * @block: start physical block to free
4645 * @count: number of blocks to count
4646 * @flags: flags used by ext4_free_blocks
4648 void ext4_free_blocks(handle_t
*handle
, struct inode
*inode
,
4649 struct buffer_head
*bh
, ext4_fsblk_t block
,
4650 unsigned long count
, int flags
)
4652 struct buffer_head
*bitmap_bh
= NULL
;
4653 struct super_block
*sb
= inode
->i_sb
;
4654 struct ext4_group_desc
*gdp
;
4655 unsigned int overflow
;
4657 struct buffer_head
*gd_bh
;
4658 ext4_group_t block_group
;
4659 struct ext4_sb_info
*sbi
;
4660 struct ext4_buddy e4b
;
4661 unsigned int count_clusters
;
4668 BUG_ON(block
!= bh
->b_blocknr
);
4670 block
= bh
->b_blocknr
;
4674 if (!(flags
& EXT4_FREE_BLOCKS_VALIDATED
) &&
4675 !ext4_data_block_valid(sbi
, block
, count
)) {
4676 ext4_error(sb
, "Freeing blocks not in datazone - "
4677 "block = %llu, count = %lu", block
, count
);
4681 ext4_debug("freeing block %llu\n", block
);
4682 trace_ext4_free_blocks(inode
, block
, count
, flags
);
4684 if (flags
& EXT4_FREE_BLOCKS_FORGET
) {
4685 struct buffer_head
*tbh
= bh
;
4688 BUG_ON(bh
&& (count
> 1));
4690 for (i
= 0; i
< count
; i
++) {
4693 tbh
= sb_find_get_block(inode
->i_sb
,
4697 ext4_forget(handle
, flags
& EXT4_FREE_BLOCKS_METADATA
,
4698 inode
, tbh
, block
+ i
);
4703 * We need to make sure we don't reuse the freed block until
4704 * after the transaction is committed, which we can do by
4705 * treating the block as metadata, below. We make an
4706 * exception if the inode is to be written in writeback mode
4707 * since writeback mode has weak data consistency guarantees.
4709 if (!ext4_should_writeback_data(inode
))
4710 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4713 * If the extent to be freed does not begin on a cluster
4714 * boundary, we need to deal with partial clusters at the
4715 * beginning and end of the extent. Normally we will free
4716 * blocks at the beginning or the end unless we are explicitly
4717 * requested to avoid doing so.
4719 overflow
= EXT4_PBLK_COFF(sbi
, block
);
4721 if (flags
& EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER
) {
4722 overflow
= sbi
->s_cluster_ratio
- overflow
;
4724 if (count
> overflow
)
4733 overflow
= EXT4_LBLK_COFF(sbi
, count
);
4735 if (flags
& EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER
) {
4736 if (count
> overflow
)
4741 count
+= sbi
->s_cluster_ratio
- overflow
;
4746 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4748 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
4749 ext4_get_group_info(sb
, block_group
))))
4753 * Check to see if we are freeing blocks across a group
4756 if (EXT4_C2B(sbi
, bit
) + count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4757 overflow
= EXT4_C2B(sbi
, bit
) + count
-
4758 EXT4_BLOCKS_PER_GROUP(sb
);
4761 count_clusters
= EXT4_NUM_B2C(sbi
, count
);
4762 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4767 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4773 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4774 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4775 in_range(block
, ext4_inode_table(sb
, gdp
),
4776 EXT4_SB(sb
)->s_itb_per_group
) ||
4777 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4778 EXT4_SB(sb
)->s_itb_per_group
)) {
4780 ext4_error(sb
, "Freeing blocks in system zone - "
4781 "Block = %llu, count = %lu", block
, count
);
4782 /* err = 0. ext4_std_error should be a no op */
4786 BUFFER_TRACE(bitmap_bh
, "getting write access");
4787 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4792 * We are about to modify some metadata. Call the journal APIs
4793 * to unshare ->b_data if a currently-committing transaction is
4796 BUFFER_TRACE(gd_bh
, "get_write_access");
4797 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4800 #ifdef AGGRESSIVE_CHECK
4803 for (i
= 0; i
< count_clusters
; i
++)
4804 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4807 trace_ext4_mballoc_free(sb
, inode
, block_group
, bit
, count_clusters
);
4809 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4813 if ((flags
& EXT4_FREE_BLOCKS_METADATA
) && ext4_handle_valid(handle
)) {
4814 struct ext4_free_data
*new_entry
;
4816 * blocks being freed are metadata. these blocks shouldn't
4817 * be used until this transaction is committed
4819 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
4822 new_entry
= kmem_cache_alloc(ext4_free_data_cachep
,
4823 GFP_NOFS
|__GFP_NOFAIL
);
4824 new_entry
->efd_start_cluster
= bit
;
4825 new_entry
->efd_group
= block_group
;
4826 new_entry
->efd_count
= count_clusters
;
4827 new_entry
->efd_tid
= handle
->h_transaction
->t_tid
;
4829 ext4_lock_group(sb
, block_group
);
4830 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4831 ext4_mb_free_metadata(handle
, &e4b
, new_entry
);
4833 /* need to update group_info->bb_free and bitmap
4834 * with group lock held. generate_buddy look at
4835 * them with group lock_held
4837 if (test_opt(sb
, DISCARD
)) {
4838 err
= ext4_issue_discard(sb
, block_group
, bit
, count
);
4839 if (err
&& err
!= -EOPNOTSUPP
)
4840 ext4_msg(sb
, KERN_WARNING
, "discard request in"
4841 " group:%d block:%d count:%lu failed"
4842 " with %d", block_group
, bit
, count
,
4845 EXT4_MB_GRP_CLEAR_TRIMMED(e4b
.bd_info
);
4847 ext4_lock_group(sb
, block_group
);
4848 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4849 mb_free_blocks(inode
, &e4b
, bit
, count_clusters
);
4852 ret
= ext4_free_group_clusters(sb
, gdp
) + count_clusters
;
4853 ext4_free_group_clusters_set(sb
, gdp
, ret
);
4854 ext4_block_bitmap_csum_set(sb
, block_group
, gdp
, bitmap_bh
);
4855 ext4_group_desc_csum_set(sb
, block_group
, gdp
);
4856 ext4_unlock_group(sb
, block_group
);
4858 if (sbi
->s_log_groups_per_flex
) {
4859 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4860 atomic64_add(count_clusters
,
4861 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4864 if (!(flags
& EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
))
4865 dquot_free_block(inode
, EXT4_C2B(sbi
, count_clusters
));
4866 percpu_counter_add(&sbi
->s_freeclusters_counter
, count_clusters
);
4868 ext4_mb_unload_buddy(&e4b
);
4870 /* We dirtied the bitmap block */
4871 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4872 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4874 /* And the group descriptor block */
4875 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4876 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4880 if (overflow
&& !err
) {
4888 ext4_std_error(sb
, err
);
4893 * ext4_group_add_blocks() -- Add given blocks to an existing group
4894 * @handle: handle to this transaction
4896 * @block: start physical block to add to the block group
4897 * @count: number of blocks to free
4899 * This marks the blocks as free in the bitmap and buddy.
4901 int ext4_group_add_blocks(handle_t
*handle
, struct super_block
*sb
,
4902 ext4_fsblk_t block
, unsigned long count
)
4904 struct buffer_head
*bitmap_bh
= NULL
;
4905 struct buffer_head
*gd_bh
;
4906 ext4_group_t block_group
;
4909 struct ext4_group_desc
*desc
;
4910 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4911 struct ext4_buddy e4b
;
4912 int err
= 0, ret
, blk_free_count
;
4913 ext4_grpblk_t blocks_freed
;
4915 ext4_debug("Adding block(s) %llu-%llu\n", block
, block
+ count
- 1);
4920 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4922 * Check to see if we are freeing blocks across a group
4925 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4926 ext4_warning(sb
, "too much blocks added to group %u\n",
4932 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4938 desc
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4944 if (in_range(ext4_block_bitmap(sb
, desc
), block
, count
) ||
4945 in_range(ext4_inode_bitmap(sb
, desc
), block
, count
) ||
4946 in_range(block
, ext4_inode_table(sb
, desc
), sbi
->s_itb_per_group
) ||
4947 in_range(block
+ count
- 1, ext4_inode_table(sb
, desc
),
4948 sbi
->s_itb_per_group
)) {
4949 ext4_error(sb
, "Adding blocks in system zones - "
4950 "Block = %llu, count = %lu",
4956 BUFFER_TRACE(bitmap_bh
, "getting write access");
4957 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4962 * We are about to modify some metadata. Call the journal APIs
4963 * to unshare ->b_data if a currently-committing transaction is
4966 BUFFER_TRACE(gd_bh
, "get_write_access");
4967 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4971 for (i
= 0, blocks_freed
= 0; i
< count
; i
++) {
4972 BUFFER_TRACE(bitmap_bh
, "clear bit");
4973 if (!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
)) {
4974 ext4_error(sb
, "bit already cleared for block %llu",
4975 (ext4_fsblk_t
)(block
+ i
));
4976 BUFFER_TRACE(bitmap_bh
, "bit already cleared");
4982 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4987 * need to update group_info->bb_free and bitmap
4988 * with group lock held. generate_buddy look at
4989 * them with group lock_held
4991 ext4_lock_group(sb
, block_group
);
4992 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4993 mb_free_blocks(NULL
, &e4b
, bit
, count
);
4994 blk_free_count
= blocks_freed
+ ext4_free_group_clusters(sb
, desc
);
4995 ext4_free_group_clusters_set(sb
, desc
, blk_free_count
);
4996 ext4_block_bitmap_csum_set(sb
, block_group
, desc
, bitmap_bh
);
4997 ext4_group_desc_csum_set(sb
, block_group
, desc
);
4998 ext4_unlock_group(sb
, block_group
);
4999 percpu_counter_add(&sbi
->s_freeclusters_counter
,
5000 EXT4_NUM_B2C(sbi
, blocks_freed
));
5002 if (sbi
->s_log_groups_per_flex
) {
5003 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
5004 atomic64_add(EXT4_NUM_B2C(sbi
, blocks_freed
),
5005 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
5008 ext4_mb_unload_buddy(&e4b
);
5010 /* We dirtied the bitmap block */
5011 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
5012 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
5014 /* And the group descriptor block */
5015 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
5016 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
5022 ext4_std_error(sb
, err
);
5027 * ext4_trim_extent -- function to TRIM one single free extent in the group
5028 * @sb: super block for the file system
5029 * @start: starting block of the free extent in the alloc. group
5030 * @count: number of blocks to TRIM
5031 * @group: alloc. group we are working with
5032 * @e4b: ext4 buddy for the group
5034 * Trim "count" blocks starting at "start" in the "group". To assure that no
5035 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5036 * be called with under the group lock.
5038 static int ext4_trim_extent(struct super_block
*sb
, int start
, int count
,
5039 ext4_group_t group
, struct ext4_buddy
*e4b
)
5043 struct ext4_free_extent ex
;
5046 trace_ext4_trim_extent(sb
, group
, start
, count
);
5048 assert_spin_locked(ext4_group_lock_ptr(sb
, group
));
5050 ex
.fe_start
= start
;
5051 ex
.fe_group
= group
;
5055 * Mark blocks used, so no one can reuse them while
5058 mb_mark_used(e4b
, &ex
);
5059 ext4_unlock_group(sb
, group
);
5060 ret
= ext4_issue_discard(sb
, group
, start
, count
);
5061 ext4_lock_group(sb
, group
);
5062 mb_free_blocks(NULL
, e4b
, start
, ex
.fe_len
);
5067 * ext4_trim_all_free -- function to trim all free space in alloc. group
5068 * @sb: super block for file system
5069 * @group: group to be trimmed
5070 * @start: first group block to examine
5071 * @max: last group block to examine
5072 * @minblocks: minimum extent block count
5074 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5075 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5079 * ext4_trim_all_free walks through group's block bitmap searching for free
5080 * extents. When the free extent is found, mark it as used in group buddy
5081 * bitmap. Then issue a TRIM command on this extent and free the extent in
5082 * the group buddy bitmap. This is done until whole group is scanned.
5084 static ext4_grpblk_t
5085 ext4_trim_all_free(struct super_block
*sb
, ext4_group_t group
,
5086 ext4_grpblk_t start
, ext4_grpblk_t max
,
5087 ext4_grpblk_t minblocks
)
5090 ext4_grpblk_t next
, count
= 0, free_count
= 0;
5091 struct ext4_buddy e4b
;
5094 trace_ext4_trim_all_free(sb
, group
, start
, max
);
5096 ret
= ext4_mb_load_buddy(sb
, group
, &e4b
);
5098 ext4_error(sb
, "Error in loading buddy "
5099 "information for %u", group
);
5102 bitmap
= e4b
.bd_bitmap
;
5104 ext4_lock_group(sb
, group
);
5105 if (EXT4_MB_GRP_WAS_TRIMMED(e4b
.bd_info
) &&
5106 minblocks
>= atomic_read(&EXT4_SB(sb
)->s_last_trim_minblks
))
5109 start
= (e4b
.bd_info
->bb_first_free
> start
) ?
5110 e4b
.bd_info
->bb_first_free
: start
;
5112 while (start
<= max
) {
5113 start
= mb_find_next_zero_bit(bitmap
, max
+ 1, start
);
5116 next
= mb_find_next_bit(bitmap
, max
+ 1, start
);
5118 if ((next
- start
) >= minblocks
) {
5119 ret
= ext4_trim_extent(sb
, start
,
5120 next
- start
, group
, &e4b
);
5121 if (ret
&& ret
!= -EOPNOTSUPP
)
5124 count
+= next
- start
;
5126 free_count
+= next
- start
;
5129 if (fatal_signal_pending(current
)) {
5130 count
= -ERESTARTSYS
;
5134 if (need_resched()) {
5135 ext4_unlock_group(sb
, group
);
5137 ext4_lock_group(sb
, group
);
5140 if ((e4b
.bd_info
->bb_free
- free_count
) < minblocks
)
5146 EXT4_MB_GRP_SET_TRIMMED(e4b
.bd_info
);
5149 ext4_unlock_group(sb
, group
);
5150 ext4_mb_unload_buddy(&e4b
);
5152 ext4_debug("trimmed %d blocks in the group %d\n",
5159 * ext4_trim_fs() -- trim ioctl handle function
5160 * @sb: superblock for filesystem
5161 * @range: fstrim_range structure
5163 * start: First Byte to trim
5164 * len: number of Bytes to trim from start
5165 * minlen: minimum extent length in Bytes
5166 * ext4_trim_fs goes through all allocation groups containing Bytes from
5167 * start to start+len. For each such a group ext4_trim_all_free function
5168 * is invoked to trim all free space.
5170 int ext4_trim_fs(struct super_block
*sb
, struct fstrim_range
*range
)
5172 struct ext4_group_info
*grp
;
5173 ext4_group_t group
, first_group
, last_group
;
5174 ext4_grpblk_t cnt
= 0, first_cluster
, last_cluster
;
5175 uint64_t start
, end
, minlen
, trimmed
= 0;
5176 ext4_fsblk_t first_data_blk
=
5177 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
5178 ext4_fsblk_t max_blks
= ext4_blocks_count(EXT4_SB(sb
)->s_es
);
5181 start
= range
->start
>> sb
->s_blocksize_bits
;
5182 end
= start
+ (range
->len
>> sb
->s_blocksize_bits
) - 1;
5183 minlen
= EXT4_NUM_B2C(EXT4_SB(sb
),
5184 range
->minlen
>> sb
->s_blocksize_bits
);
5186 if (minlen
> EXT4_CLUSTERS_PER_GROUP(sb
) ||
5187 start
>= max_blks
||
5188 range
->len
< sb
->s_blocksize
)
5190 if (end
>= max_blks
)
5192 if (end
<= first_data_blk
)
5194 if (start
< first_data_blk
)
5195 start
= first_data_blk
;
5197 /* Determine first and last group to examine based on start and end */
5198 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) start
,
5199 &first_group
, &first_cluster
);
5200 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) end
,
5201 &last_group
, &last_cluster
);
5203 /* end now represents the last cluster to discard in this group */
5204 end
= EXT4_CLUSTERS_PER_GROUP(sb
) - 1;
5206 for (group
= first_group
; group
<= last_group
; group
++) {
5207 grp
= ext4_get_group_info(sb
, group
);
5208 /* We only do this if the grp has never been initialized */
5209 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
5210 ret
= ext4_mb_init_group(sb
, group
);
5216 * For all the groups except the last one, last cluster will
5217 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5218 * change it for the last group, note that last_cluster is
5219 * already computed earlier by ext4_get_group_no_and_offset()
5221 if (group
== last_group
)
5224 if (grp
->bb_free
>= minlen
) {
5225 cnt
= ext4_trim_all_free(sb
, group
, first_cluster
,
5235 * For every group except the first one, we are sure
5236 * that the first cluster to discard will be cluster #0.
5242 atomic_set(&EXT4_SB(sb
)->s_last_trim_minblks
, minlen
);
5245 range
->len
= EXT4_C2B(EXT4_SB(sb
), trimmed
) << sb
->s_blocksize_bits
;