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
])) {
891 first_block
= page
->index
* blocks_per_page
;
892 for (i
= 0; i
< blocks_per_page
; i
++) {
893 group
= (first_block
+ i
) >> 1;
894 if (group
>= ngroups
)
897 if (!bh
[group
- first_group
])
898 /* skip initialized uptodate buddy */
902 * data carry information regarding this
903 * particular group in the format specified
907 data
= page_address(page
) + (i
* blocksize
);
908 bitmap
= bh
[group
- first_group
]->b_data
;
911 * We place the buddy block and bitmap block
914 if ((first_block
+ i
) & 1) {
915 /* this is block of buddy */
916 BUG_ON(incore
== NULL
);
917 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
918 group
, page
->index
, i
* blocksize
);
919 trace_ext4_mb_buddy_bitmap_load(sb
, group
);
920 grinfo
= ext4_get_group_info(sb
, group
);
921 grinfo
->bb_fragments
= 0;
922 memset(grinfo
->bb_counters
, 0,
923 sizeof(*grinfo
->bb_counters
) *
924 (sb
->s_blocksize_bits
+2));
926 * incore got set to the group block bitmap below
928 ext4_lock_group(sb
, group
);
930 memset(data
, 0xff, blocksize
);
931 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
932 ext4_unlock_group(sb
, group
);
935 /* this is block of bitmap */
936 BUG_ON(incore
!= NULL
);
937 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
938 group
, page
->index
, i
* blocksize
);
939 trace_ext4_mb_bitmap_load(sb
, group
);
941 /* see comments in ext4_mb_put_pa() */
942 ext4_lock_group(sb
, group
);
943 memcpy(data
, bitmap
, blocksize
);
945 /* mark all preallocated blks used in in-core bitmap */
946 ext4_mb_generate_from_pa(sb
, data
, group
);
947 ext4_mb_generate_from_freelist(sb
, data
, group
);
948 ext4_unlock_group(sb
, group
);
950 /* set incore so that the buddy information can be
951 * generated using this
956 SetPageUptodate(page
);
960 for (i
= 0; i
< groups_per_page
; i
++)
969 * Lock the buddy and bitmap pages. This make sure other parallel init_group
970 * on the same buddy page doesn't happen whild holding the buddy page lock.
971 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
972 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
974 static int ext4_mb_get_buddy_page_lock(struct super_block
*sb
,
975 ext4_group_t group
, struct ext4_buddy
*e4b
)
977 struct inode
*inode
= EXT4_SB(sb
)->s_buddy_cache
;
978 int block
, pnum
, poff
;
982 e4b
->bd_buddy_page
= NULL
;
983 e4b
->bd_bitmap_page
= NULL
;
985 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
987 * the buddy cache inode stores the block bitmap
988 * and buddy information in consecutive blocks.
989 * So for each group we need two blocks.
992 pnum
= block
/ blocks_per_page
;
993 poff
= block
% blocks_per_page
;
994 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
997 BUG_ON(page
->mapping
!= inode
->i_mapping
);
998 e4b
->bd_bitmap_page
= page
;
999 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1001 if (blocks_per_page
>= 2) {
1002 /* buddy and bitmap are on the same page */
1007 pnum
= block
/ blocks_per_page
;
1008 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1011 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1012 e4b
->bd_buddy_page
= page
;
1016 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy
*e4b
)
1018 if (e4b
->bd_bitmap_page
) {
1019 unlock_page(e4b
->bd_bitmap_page
);
1020 page_cache_release(e4b
->bd_bitmap_page
);
1022 if (e4b
->bd_buddy_page
) {
1023 unlock_page(e4b
->bd_buddy_page
);
1024 page_cache_release(e4b
->bd_buddy_page
);
1029 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1030 * block group lock of all groups for this page; do not hold the BG lock when
1031 * calling this routine!
1033 static noinline_for_stack
1034 int ext4_mb_init_group(struct super_block
*sb
, ext4_group_t group
)
1037 struct ext4_group_info
*this_grp
;
1038 struct ext4_buddy e4b
;
1043 mb_debug(1, "init group %u\n", group
);
1044 this_grp
= ext4_get_group_info(sb
, group
);
1046 * This ensures that we don't reinit the buddy cache
1047 * page which map to the group from which we are already
1048 * allocating. If we are looking at the buddy cache we would
1049 * have taken a reference using ext4_mb_load_buddy and that
1050 * would have pinned buddy page to page cache.
1051 * The call to ext4_mb_get_buddy_page_lock will mark the
1054 ret
= ext4_mb_get_buddy_page_lock(sb
, group
, &e4b
);
1055 if (ret
|| !EXT4_MB_GRP_NEED_INIT(this_grp
)) {
1057 * somebody initialized the group
1058 * return without doing anything
1063 page
= e4b
.bd_bitmap_page
;
1064 ret
= ext4_mb_init_cache(page
, NULL
);
1067 if (!PageUptodate(page
)) {
1072 if (e4b
.bd_buddy_page
== NULL
) {
1074 * If both the bitmap and buddy are in
1075 * the same page we don't need to force
1081 /* init buddy cache */
1082 page
= e4b
.bd_buddy_page
;
1083 ret
= ext4_mb_init_cache(page
, e4b
.bd_bitmap
);
1086 if (!PageUptodate(page
)) {
1091 ext4_mb_put_buddy_page_lock(&e4b
);
1096 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1097 * block group lock of all groups for this page; do not hold the BG lock when
1098 * calling this routine!
1100 static noinline_for_stack
int
1101 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
1102 struct ext4_buddy
*e4b
)
1104 int blocks_per_page
;
1110 struct ext4_group_info
*grp
;
1111 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1112 struct inode
*inode
= sbi
->s_buddy_cache
;
1115 mb_debug(1, "load group %u\n", group
);
1117 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1118 grp
= ext4_get_group_info(sb
, group
);
1120 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
1123 e4b
->bd_group
= group
;
1124 e4b
->bd_buddy_page
= NULL
;
1125 e4b
->bd_bitmap_page
= NULL
;
1127 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1129 * we need full data about the group
1130 * to make a good selection
1132 ret
= ext4_mb_init_group(sb
, group
);
1138 * the buddy cache inode stores the block bitmap
1139 * and buddy information in consecutive blocks.
1140 * So for each group we need two blocks.
1143 pnum
= block
/ blocks_per_page
;
1144 poff
= block
% blocks_per_page
;
1146 /* we could use find_or_create_page(), but it locks page
1147 * what we'd like to avoid in fast path ... */
1148 page
= find_get_page_flags(inode
->i_mapping
, pnum
, FGP_ACCESSED
);
1149 if (page
== NULL
|| !PageUptodate(page
)) {
1152 * drop the page reference and try
1153 * to get the page with lock. If we
1154 * are not uptodate that implies
1155 * somebody just created the page but
1156 * is yet to initialize the same. So
1157 * wait for it to initialize.
1159 page_cache_release(page
);
1160 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1162 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1163 if (!PageUptodate(page
)) {
1164 ret
= ext4_mb_init_cache(page
, NULL
);
1169 mb_cmp_bitmaps(e4b
, page_address(page
) +
1170 (poff
* sb
->s_blocksize
));
1179 if (!PageUptodate(page
)) {
1184 /* Pages marked accessed already */
1185 e4b
->bd_bitmap_page
= page
;
1186 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1189 pnum
= block
/ blocks_per_page
;
1190 poff
= block
% blocks_per_page
;
1192 page
= find_get_page_flags(inode
->i_mapping
, pnum
, FGP_ACCESSED
);
1193 if (page
== NULL
|| !PageUptodate(page
)) {
1195 page_cache_release(page
);
1196 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1198 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1199 if (!PageUptodate(page
)) {
1200 ret
= ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
1213 if (!PageUptodate(page
)) {
1218 /* Pages marked accessed already */
1219 e4b
->bd_buddy_page
= page
;
1220 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
1222 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
1223 BUG_ON(e4b
->bd_buddy_page
== NULL
);
1229 page_cache_release(page
);
1230 if (e4b
->bd_bitmap_page
)
1231 page_cache_release(e4b
->bd_bitmap_page
);
1232 if (e4b
->bd_buddy_page
)
1233 page_cache_release(e4b
->bd_buddy_page
);
1234 e4b
->bd_buddy
= NULL
;
1235 e4b
->bd_bitmap
= NULL
;
1239 static void ext4_mb_unload_buddy(struct ext4_buddy
*e4b
)
1241 if (e4b
->bd_bitmap_page
)
1242 page_cache_release(e4b
->bd_bitmap_page
);
1243 if (e4b
->bd_buddy_page
)
1244 page_cache_release(e4b
->bd_buddy_page
);
1248 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
1253 BUG_ON(e4b
->bd_bitmap
== e4b
->bd_buddy
);
1254 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
1257 while (order
<= e4b
->bd_blkbits
+ 1) {
1259 if (!mb_test_bit(block
, bb
)) {
1260 /* this block is part of buddy of order 'order' */
1263 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1269 static void mb_clear_bits(void *bm
, int cur
, int len
)
1275 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1276 /* fast path: clear whole word at once */
1277 addr
= bm
+ (cur
>> 3);
1282 mb_clear_bit(cur
, bm
);
1287 /* clear bits in given range
1288 * will return first found zero bit if any, -1 otherwise
1290 static int mb_test_and_clear_bits(void *bm
, int cur
, int len
)
1297 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1298 /* fast path: clear whole word at once */
1299 addr
= bm
+ (cur
>> 3);
1300 if (*addr
!= (__u32
)(-1) && zero_bit
== -1)
1301 zero_bit
= cur
+ mb_find_next_zero_bit(addr
, 32, 0);
1306 if (!mb_test_and_clear_bit(cur
, bm
) && zero_bit
== -1)
1314 void ext4_set_bits(void *bm
, int cur
, int len
)
1320 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1321 /* fast path: set whole word at once */
1322 addr
= bm
+ (cur
>> 3);
1327 mb_set_bit(cur
, bm
);
1333 * _________________________________________________________________ */
1335 static inline int mb_buddy_adjust_border(int* bit
, void* bitmap
, int side
)
1337 if (mb_test_bit(*bit
+ side
, bitmap
)) {
1338 mb_clear_bit(*bit
, bitmap
);
1344 mb_set_bit(*bit
, bitmap
);
1349 static void mb_buddy_mark_free(struct ext4_buddy
*e4b
, int first
, int last
)
1353 void *buddy
= mb_find_buddy(e4b
, order
, &max
);
1358 /* Bits in range [first; last] are known to be set since
1359 * corresponding blocks were allocated. Bits in range
1360 * (first; last) will stay set because they form buddies on
1361 * upper layer. We just deal with borders if they don't
1362 * align with upper layer and then go up.
1363 * Releasing entire group is all about clearing
1364 * single bit of highest order buddy.
1368 * ---------------------------------
1370 * ---------------------------------
1371 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1372 * ---------------------------------
1374 * \_____________________/
1376 * Neither [1] nor [6] is aligned to above layer.
1377 * Left neighbour [0] is free, so mark it busy,
1378 * decrease bb_counters and extend range to
1380 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1381 * mark [6] free, increase bb_counters and shrink range to
1383 * Then shift range to [0; 2], go up and do the same.
1388 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&first
, buddy
, -1);
1390 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&last
, buddy
, 1);
1395 if (first
== last
|| !(buddy2
= mb_find_buddy(e4b
, order
, &max
))) {
1396 mb_clear_bits(buddy
, first
, last
- first
+ 1);
1397 e4b
->bd_info
->bb_counters
[order
- 1] += last
- first
+ 1;
1406 static void mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1407 int first
, int count
)
1409 int left_is_free
= 0;
1410 int right_is_free
= 0;
1412 int last
= first
+ count
- 1;
1413 struct super_block
*sb
= e4b
->bd_sb
;
1415 BUG_ON(last
>= (sb
->s_blocksize
<< 3));
1416 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
1417 /* Don't bother if the block group is corrupt. */
1418 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
)))
1421 mb_check_buddy(e4b
);
1422 mb_free_blocks_double(inode
, e4b
, first
, count
);
1424 e4b
->bd_info
->bb_free
+= count
;
1425 if (first
< e4b
->bd_info
->bb_first_free
)
1426 e4b
->bd_info
->bb_first_free
= first
;
1428 /* access memory sequentially: check left neighbour,
1429 * clear range and then check right neighbour
1432 left_is_free
= !mb_test_bit(first
- 1, e4b
->bd_bitmap
);
1433 block
= mb_test_and_clear_bits(e4b
->bd_bitmap
, first
, count
);
1434 if (last
+ 1 < EXT4_SB(sb
)->s_mb_maxs
[0])
1435 right_is_free
= !mb_test_bit(last
+ 1, e4b
->bd_bitmap
);
1437 if (unlikely(block
!= -1)) {
1438 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1439 ext4_fsblk_t blocknr
;
1441 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1442 blocknr
+= EXT4_C2B(EXT4_SB(sb
), block
);
1443 ext4_grp_locked_error(sb
, e4b
->bd_group
,
1444 inode
? inode
->i_ino
: 0,
1446 "freeing already freed block "
1447 "(bit %u); block bitmap corrupt.",
1449 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
))
1450 percpu_counter_sub(&sbi
->s_freeclusters_counter
,
1451 e4b
->bd_info
->bb_free
);
1452 /* Mark the block group as corrupt. */
1453 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT
,
1454 &e4b
->bd_info
->bb_state
);
1455 mb_regenerate_buddy(e4b
);
1459 /* let's maintain fragments counter */
1460 if (left_is_free
&& right_is_free
)
1461 e4b
->bd_info
->bb_fragments
--;
1462 else if (!left_is_free
&& !right_is_free
)
1463 e4b
->bd_info
->bb_fragments
++;
1465 /* buddy[0] == bd_bitmap is a special case, so handle
1466 * it right away and let mb_buddy_mark_free stay free of
1467 * zero order checks.
1468 * Check if neighbours are to be coaleasced,
1469 * adjust bitmap bb_counters and borders appropriately.
1472 first
+= !left_is_free
;
1473 e4b
->bd_info
->bb_counters
[0] += left_is_free
? -1 : 1;
1476 last
-= !right_is_free
;
1477 e4b
->bd_info
->bb_counters
[0] += right_is_free
? -1 : 1;
1481 mb_buddy_mark_free(e4b
, first
>> 1, last
>> 1);
1484 mb_set_largest_free_order(sb
, e4b
->bd_info
);
1485 mb_check_buddy(e4b
);
1488 static int mb_find_extent(struct ext4_buddy
*e4b
, int block
,
1489 int needed
, struct ext4_free_extent
*ex
)
1495 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1498 buddy
= mb_find_buddy(e4b
, 0, &max
);
1499 BUG_ON(buddy
== NULL
);
1500 BUG_ON(block
>= max
);
1501 if (mb_test_bit(block
, buddy
)) {
1508 /* find actual order */
1509 order
= mb_find_order_for_block(e4b
, block
);
1510 block
= block
>> order
;
1512 ex
->fe_len
= 1 << order
;
1513 ex
->fe_start
= block
<< order
;
1514 ex
->fe_group
= e4b
->bd_group
;
1516 /* calc difference from given start */
1517 next
= next
- ex
->fe_start
;
1519 ex
->fe_start
+= next
;
1521 while (needed
> ex
->fe_len
&&
1522 mb_find_buddy(e4b
, order
, &max
)) {
1524 if (block
+ 1 >= max
)
1527 next
= (block
+ 1) * (1 << order
);
1528 if (mb_test_bit(next
, e4b
->bd_bitmap
))
1531 order
= mb_find_order_for_block(e4b
, next
);
1533 block
= next
>> order
;
1534 ex
->fe_len
+= 1 << order
;
1537 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1541 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1547 int start
= ex
->fe_start
;
1548 int len
= ex
->fe_len
;
1553 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1554 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1555 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1556 mb_check_buddy(e4b
);
1557 mb_mark_used_double(e4b
, start
, len
);
1559 e4b
->bd_info
->bb_free
-= len
;
1560 if (e4b
->bd_info
->bb_first_free
== start
)
1561 e4b
->bd_info
->bb_first_free
+= len
;
1563 /* let's maintain fragments counter */
1565 mlen
= !mb_test_bit(start
- 1, e4b
->bd_bitmap
);
1566 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1567 max
= !mb_test_bit(start
+ len
, e4b
->bd_bitmap
);
1569 e4b
->bd_info
->bb_fragments
++;
1570 else if (!mlen
&& !max
)
1571 e4b
->bd_info
->bb_fragments
--;
1573 /* let's maintain buddy itself */
1575 ord
= mb_find_order_for_block(e4b
, start
);
1577 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1578 /* the whole chunk may be allocated at once! */
1580 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1581 BUG_ON((start
>> ord
) >= max
);
1582 mb_set_bit(start
>> ord
, buddy
);
1583 e4b
->bd_info
->bb_counters
[ord
]--;
1590 /* store for history */
1592 ret
= len
| (ord
<< 16);
1594 /* we have to split large buddy */
1596 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1597 mb_set_bit(start
>> ord
, buddy
);
1598 e4b
->bd_info
->bb_counters
[ord
]--;
1601 cur
= (start
>> ord
) & ~1U;
1602 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1603 mb_clear_bit(cur
, buddy
);
1604 mb_clear_bit(cur
+ 1, buddy
);
1605 e4b
->bd_info
->bb_counters
[ord
]++;
1606 e4b
->bd_info
->bb_counters
[ord
]++;
1608 mb_set_largest_free_order(e4b
->bd_sb
, e4b
->bd_info
);
1610 ext4_set_bits(e4b
->bd_bitmap
, ex
->fe_start
, len0
);
1611 mb_check_buddy(e4b
);
1617 * Must be called under group lock!
1619 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1620 struct ext4_buddy
*e4b
)
1622 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1625 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1626 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1628 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1629 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1630 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1632 /* preallocation can change ac_b_ex, thus we store actually
1633 * allocated blocks for history */
1634 ac
->ac_f_ex
= ac
->ac_b_ex
;
1636 ac
->ac_status
= AC_STATUS_FOUND
;
1637 ac
->ac_tail
= ret
& 0xffff;
1638 ac
->ac_buddy
= ret
>> 16;
1641 * take the page reference. We want the page to be pinned
1642 * so that we don't get a ext4_mb_init_cache_call for this
1643 * group until we update the bitmap. That would mean we
1644 * double allocate blocks. The reference is dropped
1645 * in ext4_mb_release_context
1647 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1648 get_page(ac
->ac_bitmap_page
);
1649 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1650 get_page(ac
->ac_buddy_page
);
1651 /* store last allocated for subsequent stream allocation */
1652 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
1653 spin_lock(&sbi
->s_md_lock
);
1654 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1655 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1656 spin_unlock(&sbi
->s_md_lock
);
1661 * regular allocator, for general purposes allocation
1664 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1665 struct ext4_buddy
*e4b
,
1668 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1669 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1670 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1671 struct ext4_free_extent ex
;
1674 if (ac
->ac_status
== AC_STATUS_FOUND
)
1677 * We don't want to scan for a whole year
1679 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1680 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1681 ac
->ac_status
= AC_STATUS_BREAK
;
1686 * Haven't found good chunk so far, let's continue
1688 if (bex
->fe_len
< gex
->fe_len
)
1691 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1692 && bex
->fe_group
== e4b
->bd_group
) {
1693 /* recheck chunk's availability - we don't know
1694 * when it was found (within this lock-unlock
1696 max
= mb_find_extent(e4b
, bex
->fe_start
, gex
->fe_len
, &ex
);
1697 if (max
>= gex
->fe_len
) {
1698 ext4_mb_use_best_found(ac
, e4b
);
1705 * The routine checks whether found extent is good enough. If it is,
1706 * then the extent gets marked used and flag is set to the context
1707 * to stop scanning. Otherwise, the extent is compared with the
1708 * previous found extent and if new one is better, then it's stored
1709 * in the context. Later, the best found extent will be used, if
1710 * mballoc can't find good enough extent.
1712 * FIXME: real allocation policy is to be designed yet!
1714 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1715 struct ext4_free_extent
*ex
,
1716 struct ext4_buddy
*e4b
)
1718 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1719 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1721 BUG_ON(ex
->fe_len
<= 0);
1722 BUG_ON(ex
->fe_len
> EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1723 BUG_ON(ex
->fe_start
>= EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1724 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1729 * The special case - take what you catch first
1731 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1733 ext4_mb_use_best_found(ac
, e4b
);
1738 * Let's check whether the chuck is good enough
1740 if (ex
->fe_len
== gex
->fe_len
) {
1742 ext4_mb_use_best_found(ac
, e4b
);
1747 * If this is first found extent, just store it in the context
1749 if (bex
->fe_len
== 0) {
1755 * If new found extent is better, store it in the context
1757 if (bex
->fe_len
< gex
->fe_len
) {
1758 /* if the request isn't satisfied, any found extent
1759 * larger than previous best one is better */
1760 if (ex
->fe_len
> bex
->fe_len
)
1762 } else if (ex
->fe_len
> gex
->fe_len
) {
1763 /* if the request is satisfied, then we try to find
1764 * an extent that still satisfy the request, but is
1765 * smaller than previous one */
1766 if (ex
->fe_len
< bex
->fe_len
)
1770 ext4_mb_check_limits(ac
, e4b
, 0);
1773 static noinline_for_stack
1774 int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1775 struct ext4_buddy
*e4b
)
1777 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1778 ext4_group_t group
= ex
.fe_group
;
1782 BUG_ON(ex
.fe_len
<= 0);
1783 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1787 ext4_lock_group(ac
->ac_sb
, group
);
1788 max
= mb_find_extent(e4b
, ex
.fe_start
, ex
.fe_len
, &ex
);
1792 ext4_mb_use_best_found(ac
, e4b
);
1795 ext4_unlock_group(ac
->ac_sb
, group
);
1796 ext4_mb_unload_buddy(e4b
);
1801 static noinline_for_stack
1802 int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1803 struct ext4_buddy
*e4b
)
1805 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1808 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1809 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1810 struct ext4_free_extent ex
;
1812 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1814 if (grp
->bb_free
== 0)
1817 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1821 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
))) {
1822 ext4_mb_unload_buddy(e4b
);
1826 ext4_lock_group(ac
->ac_sb
, group
);
1827 max
= mb_find_extent(e4b
, ac
->ac_g_ex
.fe_start
,
1828 ac
->ac_g_ex
.fe_len
, &ex
);
1829 ex
.fe_logical
= 0xDEADFA11; /* debug value */
1831 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1834 start
= ext4_group_first_block_no(ac
->ac_sb
, e4b
->bd_group
) +
1836 /* use do_div to get remainder (would be 64-bit modulo) */
1837 if (do_div(start
, sbi
->s_stripe
) == 0) {
1840 ext4_mb_use_best_found(ac
, e4b
);
1842 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1843 BUG_ON(ex
.fe_len
<= 0);
1844 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1845 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1848 ext4_mb_use_best_found(ac
, e4b
);
1849 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1850 /* Sometimes, caller may want to merge even small
1851 * number of blocks to an existing extent */
1852 BUG_ON(ex
.fe_len
<= 0);
1853 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1854 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1857 ext4_mb_use_best_found(ac
, e4b
);
1859 ext4_unlock_group(ac
->ac_sb
, group
);
1860 ext4_mb_unload_buddy(e4b
);
1866 * The routine scans buddy structures (not bitmap!) from given order
1867 * to max order and tries to find big enough chunk to satisfy the req
1869 static noinline_for_stack
1870 void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1871 struct ext4_buddy
*e4b
)
1873 struct super_block
*sb
= ac
->ac_sb
;
1874 struct ext4_group_info
*grp
= e4b
->bd_info
;
1880 BUG_ON(ac
->ac_2order
<= 0);
1881 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1882 if (grp
->bb_counters
[i
] == 0)
1885 buddy
= mb_find_buddy(e4b
, i
, &max
);
1886 BUG_ON(buddy
== NULL
);
1888 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1893 ac
->ac_b_ex
.fe_len
= 1 << i
;
1894 ac
->ac_b_ex
.fe_start
= k
<< i
;
1895 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1897 ext4_mb_use_best_found(ac
, e4b
);
1899 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1901 if (EXT4_SB(sb
)->s_mb_stats
)
1902 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1909 * The routine scans the group and measures all found extents.
1910 * In order to optimize scanning, caller must pass number of
1911 * free blocks in the group, so the routine can know upper limit.
1913 static noinline_for_stack
1914 void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1915 struct ext4_buddy
*e4b
)
1917 struct super_block
*sb
= ac
->ac_sb
;
1918 void *bitmap
= e4b
->bd_bitmap
;
1919 struct ext4_free_extent ex
;
1923 free
= e4b
->bd_info
->bb_free
;
1926 i
= e4b
->bd_info
->bb_first_free
;
1928 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1929 i
= mb_find_next_zero_bit(bitmap
,
1930 EXT4_CLUSTERS_PER_GROUP(sb
), i
);
1931 if (i
>= EXT4_CLUSTERS_PER_GROUP(sb
)) {
1933 * IF we have corrupt bitmap, we won't find any
1934 * free blocks even though group info says we
1935 * we have free blocks
1937 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1938 "%d free clusters as per "
1939 "group info. But bitmap says 0",
1944 mb_find_extent(e4b
, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1945 BUG_ON(ex
.fe_len
<= 0);
1946 if (free
< ex
.fe_len
) {
1947 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1948 "%d free clusters as per "
1949 "group info. But got %d blocks",
1952 * The number of free blocks differs. This mostly
1953 * indicate that the bitmap is corrupt. So exit
1954 * without claiming the space.
1958 ex
.fe_logical
= 0xDEADC0DE; /* debug value */
1959 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1965 ext4_mb_check_limits(ac
, e4b
, 1);
1969 * This is a special case for storages like raid5
1970 * we try to find stripe-aligned chunks for stripe-size-multiple requests
1972 static noinline_for_stack
1973 void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1974 struct ext4_buddy
*e4b
)
1976 struct super_block
*sb
= ac
->ac_sb
;
1977 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1978 void *bitmap
= e4b
->bd_bitmap
;
1979 struct ext4_free_extent ex
;
1980 ext4_fsblk_t first_group_block
;
1985 BUG_ON(sbi
->s_stripe
== 0);
1987 /* find first stripe-aligned block in group */
1988 first_group_block
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1990 a
= first_group_block
+ sbi
->s_stripe
- 1;
1991 do_div(a
, sbi
->s_stripe
);
1992 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1994 while (i
< EXT4_CLUSTERS_PER_GROUP(sb
)) {
1995 if (!mb_test_bit(i
, bitmap
)) {
1996 max
= mb_find_extent(e4b
, i
, sbi
->s_stripe
, &ex
);
1997 if (max
>= sbi
->s_stripe
) {
1999 ex
.fe_logical
= 0xDEADF00D; /* debug value */
2001 ext4_mb_use_best_found(ac
, e4b
);
2009 /* This is now called BEFORE we load the buddy bitmap. */
2010 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
2011 ext4_group_t group
, int cr
)
2013 unsigned free
, fragments
;
2014 int flex_size
= ext4_flex_bg_size(EXT4_SB(ac
->ac_sb
));
2015 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
2017 BUG_ON(cr
< 0 || cr
>= 4);
2019 free
= grp
->bb_free
;
2022 if (cr
<= 2 && free
< ac
->ac_g_ex
.fe_len
)
2025 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp
)))
2028 /* We only do this if the grp has never been initialized */
2029 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
2030 int ret
= ext4_mb_init_group(ac
->ac_sb
, group
);
2035 fragments
= grp
->bb_fragments
;
2041 BUG_ON(ac
->ac_2order
== 0);
2043 /* Avoid using the first bg of a flexgroup for data files */
2044 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
) &&
2045 (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) &&
2046 ((group
% flex_size
) == 0))
2049 if ((ac
->ac_2order
> ac
->ac_sb
->s_blocksize_bits
+1) ||
2050 (free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2053 if (grp
->bb_largest_free_order
< ac
->ac_2order
)
2058 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2062 if (free
>= ac
->ac_g_ex
.fe_len
)
2074 static noinline_for_stack
int
2075 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
2077 ext4_group_t ngroups
, group
, i
;
2080 struct ext4_sb_info
*sbi
;
2081 struct super_block
*sb
;
2082 struct ext4_buddy e4b
;
2086 ngroups
= ext4_get_groups_count(sb
);
2087 /* non-extent files are limited to low blocks/groups */
2088 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)))
2089 ngroups
= sbi
->s_blockfile_groups
;
2091 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
2093 /* first, try the goal */
2094 err
= ext4_mb_find_by_goal(ac
, &e4b
);
2095 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
2098 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2102 * ac->ac2_order is set only if the fe_len is a power of 2
2103 * if ac2_order is set we also set criteria to 0 so that we
2104 * try exact allocation using buddy.
2106 i
= fls(ac
->ac_g_ex
.fe_len
);
2109 * We search using buddy data only if the order of the request
2110 * is greater than equal to the sbi_s_mb_order2_reqs
2111 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2113 if (i
>= sbi
->s_mb_order2_reqs
) {
2115 * This should tell if fe_len is exactly power of 2
2117 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
2118 ac
->ac_2order
= i
- 1;
2121 /* if stream allocation is enabled, use global goal */
2122 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
2123 /* TBD: may be hot point */
2124 spin_lock(&sbi
->s_md_lock
);
2125 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
2126 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
2127 spin_unlock(&sbi
->s_md_lock
);
2130 /* Let's just scan groups to find more-less suitable blocks */
2131 cr
= ac
->ac_2order
? 0 : 1;
2133 * cr == 0 try to get exact allocation,
2134 * cr == 3 try to get anything
2137 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
2138 ac
->ac_criteria
= cr
;
2140 * searching for the right group start
2141 * from the goal value specified
2143 group
= ac
->ac_g_ex
.fe_group
;
2145 for (i
= 0; i
< ngroups
; group
++, i
++) {
2148 * Artificially restricted ngroups for non-extent
2149 * files makes group > ngroups possible on first loop.
2151 if (group
>= ngroups
)
2154 /* This now checks without needing the buddy page */
2155 if (!ext4_mb_good_group(ac
, group
, cr
))
2158 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2162 ext4_lock_group(sb
, group
);
2165 * We need to check again after locking the
2168 if (!ext4_mb_good_group(ac
, group
, cr
)) {
2169 ext4_unlock_group(sb
, group
);
2170 ext4_mb_unload_buddy(&e4b
);
2174 ac
->ac_groups_scanned
++;
2175 if (cr
== 0 && ac
->ac_2order
< sb
->s_blocksize_bits
+2)
2176 ext4_mb_simple_scan_group(ac
, &e4b
);
2177 else if (cr
== 1 && sbi
->s_stripe
&&
2178 !(ac
->ac_g_ex
.fe_len
% sbi
->s_stripe
))
2179 ext4_mb_scan_aligned(ac
, &e4b
);
2181 ext4_mb_complex_scan_group(ac
, &e4b
);
2183 ext4_unlock_group(sb
, group
);
2184 ext4_mb_unload_buddy(&e4b
);
2186 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
2191 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
2192 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
2194 * We've been searching too long. Let's try to allocate
2195 * the best chunk we've found so far
2198 ext4_mb_try_best_found(ac
, &e4b
);
2199 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
2201 * Someone more lucky has already allocated it.
2202 * The only thing we can do is just take first
2204 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2206 ac
->ac_b_ex
.fe_group
= 0;
2207 ac
->ac_b_ex
.fe_start
= 0;
2208 ac
->ac_b_ex
.fe_len
= 0;
2209 ac
->ac_status
= AC_STATUS_CONTINUE
;
2210 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
2212 atomic_inc(&sbi
->s_mb_lost_chunks
);
2220 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2222 struct super_block
*sb
= seq
->private;
2225 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2228 return (void *) ((unsigned long) group
);
2231 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2233 struct super_block
*sb
= seq
->private;
2237 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2240 return (void *) ((unsigned long) group
);
2243 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2245 struct super_block
*sb
= seq
->private;
2246 ext4_group_t group
= (ext4_group_t
) ((unsigned long) v
);
2248 int err
, buddy_loaded
= 0;
2249 struct ext4_buddy e4b
;
2250 struct ext4_group_info
*grinfo
;
2252 struct ext4_group_info info
;
2253 ext4_grpblk_t counters
[16];
2258 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2259 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2260 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2261 "group", "free", "frags", "first",
2262 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2263 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2265 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2266 sizeof(struct ext4_group_info
);
2267 grinfo
= ext4_get_group_info(sb
, group
);
2268 /* Load the group info in memory only if not already loaded. */
2269 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo
))) {
2270 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2272 seq_printf(seq
, "#%-5u: I/O error\n", group
);
2278 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2281 ext4_mb_unload_buddy(&e4b
);
2283 seq_printf(seq
, "#%-5u: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2284 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2285 for (i
= 0; i
<= 13; i
++)
2286 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2287 sg
.info
.bb_counters
[i
] : 0);
2288 seq_printf(seq
, " ]\n");
2293 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2297 static const struct seq_operations ext4_mb_seq_groups_ops
= {
2298 .start
= ext4_mb_seq_groups_start
,
2299 .next
= ext4_mb_seq_groups_next
,
2300 .stop
= ext4_mb_seq_groups_stop
,
2301 .show
= ext4_mb_seq_groups_show
,
2304 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2306 struct super_block
*sb
= PDE_DATA(inode
);
2309 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2311 struct seq_file
*m
= file
->private_data
;
2318 static const struct file_operations ext4_mb_seq_groups_fops
= {
2319 .owner
= THIS_MODULE
,
2320 .open
= ext4_mb_seq_groups_open
,
2322 .llseek
= seq_lseek
,
2323 .release
= seq_release
,
2326 static struct kmem_cache
*get_groupinfo_cache(int blocksize_bits
)
2328 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2329 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[cache_index
];
2336 * Allocate the top-level s_group_info array for the specified number
2339 int ext4_mb_alloc_groupinfo(struct super_block
*sb
, ext4_group_t ngroups
)
2341 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2343 struct ext4_group_info
***new_groupinfo
;
2345 size
= (ngroups
+ EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2346 EXT4_DESC_PER_BLOCK_BITS(sb
);
2347 if (size
<= sbi
->s_group_info_size
)
2350 size
= roundup_pow_of_two(sizeof(*sbi
->s_group_info
) * size
);
2351 new_groupinfo
= ext4_kvzalloc(size
, GFP_KERNEL
);
2352 if (!new_groupinfo
) {
2353 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy meta group");
2356 if (sbi
->s_group_info
) {
2357 memcpy(new_groupinfo
, sbi
->s_group_info
,
2358 sbi
->s_group_info_size
* sizeof(*sbi
->s_group_info
));
2359 ext4_kvfree(sbi
->s_group_info
);
2361 sbi
->s_group_info
= new_groupinfo
;
2362 sbi
->s_group_info_size
= size
/ sizeof(*sbi
->s_group_info
);
2363 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2364 sbi
->s_group_info_size
);
2368 /* Create and initialize ext4_group_info data for the given group. */
2369 int ext4_mb_add_groupinfo(struct super_block
*sb
, ext4_group_t group
,
2370 struct ext4_group_desc
*desc
)
2374 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2375 struct ext4_group_info
**meta_group_info
;
2376 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2379 * First check if this group is the first of a reserved block.
2380 * If it's true, we have to allocate a new table of pointers
2381 * to ext4_group_info structures
2383 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2384 metalen
= sizeof(*meta_group_info
) <<
2385 EXT4_DESC_PER_BLOCK_BITS(sb
);
2386 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2387 if (meta_group_info
== NULL
) {
2388 ext4_msg(sb
, KERN_ERR
, "can't allocate mem "
2389 "for a buddy group");
2390 goto exit_meta_group_info
;
2392 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] =
2397 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2398 i
= group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2400 meta_group_info
[i
] = kmem_cache_zalloc(cachep
, GFP_KERNEL
);
2401 if (meta_group_info
[i
] == NULL
) {
2402 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy mem");
2403 goto exit_group_info
;
2405 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2406 &(meta_group_info
[i
]->bb_state
));
2409 * initialize bb_free to be able to skip
2410 * empty groups without initialization
2412 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2413 meta_group_info
[i
]->bb_free
=
2414 ext4_free_clusters_after_init(sb
, group
, desc
);
2416 meta_group_info
[i
]->bb_free
=
2417 ext4_free_group_clusters(sb
, desc
);
2420 INIT_LIST_HEAD(&meta_group_info
[i
]->bb_prealloc_list
);
2421 init_rwsem(&meta_group_info
[i
]->alloc_sem
);
2422 meta_group_info
[i
]->bb_free_root
= RB_ROOT
;
2423 meta_group_info
[i
]->bb_largest_free_order
= -1; /* uninit */
2427 struct buffer_head
*bh
;
2428 meta_group_info
[i
]->bb_bitmap
=
2429 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2430 BUG_ON(meta_group_info
[i
]->bb_bitmap
== NULL
);
2431 bh
= ext4_read_block_bitmap(sb
, group
);
2433 memcpy(meta_group_info
[i
]->bb_bitmap
, bh
->b_data
,
2442 /* If a meta_group_info table has been allocated, release it now */
2443 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2444 kfree(sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)]);
2445 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] = NULL
;
2447 exit_meta_group_info
:
2449 } /* ext4_mb_add_groupinfo */
2451 static int ext4_mb_init_backend(struct super_block
*sb
)
2453 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2455 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2457 struct ext4_group_desc
*desc
;
2458 struct kmem_cache
*cachep
;
2460 err
= ext4_mb_alloc_groupinfo(sb
, ngroups
);
2464 sbi
->s_buddy_cache
= new_inode(sb
);
2465 if (sbi
->s_buddy_cache
== NULL
) {
2466 ext4_msg(sb
, KERN_ERR
, "can't get new inode");
2469 /* To avoid potentially colliding with an valid on-disk inode number,
2470 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2471 * not in the inode hash, so it should never be found by iget(), but
2472 * this will avoid confusion if it ever shows up during debugging. */
2473 sbi
->s_buddy_cache
->i_ino
= EXT4_BAD_INO
;
2474 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2475 for (i
= 0; i
< ngroups
; i
++) {
2476 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2478 ext4_msg(sb
, KERN_ERR
, "can't read descriptor %u", i
);
2481 if (ext4_mb_add_groupinfo(sb
, i
, desc
) != 0)
2488 cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2490 kmem_cache_free(cachep
, ext4_get_group_info(sb
, i
));
2491 i
= sbi
->s_group_info_size
;
2493 kfree(sbi
->s_group_info
[i
]);
2494 iput(sbi
->s_buddy_cache
);
2496 ext4_kvfree(sbi
->s_group_info
);
2500 static void ext4_groupinfo_destroy_slabs(void)
2504 for (i
= 0; i
< NR_GRPINFO_CACHES
; i
++) {
2505 if (ext4_groupinfo_caches
[i
])
2506 kmem_cache_destroy(ext4_groupinfo_caches
[i
]);
2507 ext4_groupinfo_caches
[i
] = NULL
;
2511 static int ext4_groupinfo_create_slab(size_t size
)
2513 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex
);
2515 int blocksize_bits
= order_base_2(size
);
2516 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2517 struct kmem_cache
*cachep
;
2519 if (cache_index
>= NR_GRPINFO_CACHES
)
2522 if (unlikely(cache_index
< 0))
2525 mutex_lock(&ext4_grpinfo_slab_create_mutex
);
2526 if (ext4_groupinfo_caches
[cache_index
]) {
2527 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2528 return 0; /* Already created */
2531 slab_size
= offsetof(struct ext4_group_info
,
2532 bb_counters
[blocksize_bits
+ 2]);
2534 cachep
= kmem_cache_create(ext4_groupinfo_slab_names
[cache_index
],
2535 slab_size
, 0, SLAB_RECLAIM_ACCOUNT
,
2538 ext4_groupinfo_caches
[cache_index
] = cachep
;
2540 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2543 "EXT4-fs: no memory for groupinfo slab cache\n");
2550 int ext4_mb_init(struct super_block
*sb
)
2552 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2558 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_offsets
);
2560 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2561 if (sbi
->s_mb_offsets
== NULL
) {
2566 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_maxs
);
2567 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2568 if (sbi
->s_mb_maxs
== NULL
) {
2573 ret
= ext4_groupinfo_create_slab(sb
->s_blocksize
);
2577 /* order 0 is regular bitmap */
2578 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2579 sbi
->s_mb_offsets
[0] = 0;
2583 max
= sb
->s_blocksize
<< 2;
2585 sbi
->s_mb_offsets
[i
] = offset
;
2586 sbi
->s_mb_maxs
[i
] = max
;
2587 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2590 } while (i
<= sb
->s_blocksize_bits
+ 1);
2592 spin_lock_init(&sbi
->s_md_lock
);
2593 spin_lock_init(&sbi
->s_bal_lock
);
2595 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2596 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2597 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2598 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2599 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2601 * The default group preallocation is 512, which for 4k block
2602 * sizes translates to 2 megabytes. However for bigalloc file
2603 * systems, this is probably too big (i.e, if the cluster size
2604 * is 1 megabyte, then group preallocation size becomes half a
2605 * gigabyte!). As a default, we will keep a two megabyte
2606 * group pralloc size for cluster sizes up to 64k, and after
2607 * that, we will force a minimum group preallocation size of
2608 * 32 clusters. This translates to 8 megs when the cluster
2609 * size is 256k, and 32 megs when the cluster size is 1 meg,
2610 * which seems reasonable as a default.
2612 sbi
->s_mb_group_prealloc
= max(MB_DEFAULT_GROUP_PREALLOC
>>
2613 sbi
->s_cluster_bits
, 32);
2615 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2616 * to the lowest multiple of s_stripe which is bigger than
2617 * the s_mb_group_prealloc as determined above. We want
2618 * the preallocation size to be an exact multiple of the
2619 * RAID stripe size so that preallocations don't fragment
2622 if (sbi
->s_stripe
> 1) {
2623 sbi
->s_mb_group_prealloc
= roundup(
2624 sbi
->s_mb_group_prealloc
, sbi
->s_stripe
);
2627 sbi
->s_locality_groups
= alloc_percpu(struct ext4_locality_group
);
2628 if (sbi
->s_locality_groups
== NULL
) {
2632 for_each_possible_cpu(i
) {
2633 struct ext4_locality_group
*lg
;
2634 lg
= per_cpu_ptr(sbi
->s_locality_groups
, i
);
2635 mutex_init(&lg
->lg_mutex
);
2636 for (j
= 0; j
< PREALLOC_TB_SIZE
; j
++)
2637 INIT_LIST_HEAD(&lg
->lg_prealloc_list
[j
]);
2638 spin_lock_init(&lg
->lg_prealloc_lock
);
2641 /* init file for buddy data */
2642 ret
= ext4_mb_init_backend(sb
);
2644 goto out_free_locality_groups
;
2647 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_proc
,
2648 &ext4_mb_seq_groups_fops
, sb
);
2652 out_free_locality_groups
:
2653 free_percpu(sbi
->s_locality_groups
);
2654 sbi
->s_locality_groups
= NULL
;
2656 kfree(sbi
->s_mb_offsets
);
2657 sbi
->s_mb_offsets
= NULL
;
2658 kfree(sbi
->s_mb_maxs
);
2659 sbi
->s_mb_maxs
= NULL
;
2663 /* need to called with the ext4 group lock held */
2664 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2666 struct ext4_prealloc_space
*pa
;
2667 struct list_head
*cur
, *tmp
;
2670 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2671 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2672 list_del(&pa
->pa_group_list
);
2674 kmem_cache_free(ext4_pspace_cachep
, pa
);
2677 mb_debug(1, "mballoc: %u PAs left\n", count
);
2681 int ext4_mb_release(struct super_block
*sb
)
2683 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2685 int num_meta_group_infos
;
2686 struct ext4_group_info
*grinfo
;
2687 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2688 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2691 remove_proc_entry("mb_groups", sbi
->s_proc
);
2693 if (sbi
->s_group_info
) {
2694 for (i
= 0; i
< ngroups
; i
++) {
2695 grinfo
= ext4_get_group_info(sb
, i
);
2697 kfree(grinfo
->bb_bitmap
);
2699 ext4_lock_group(sb
, i
);
2700 ext4_mb_cleanup_pa(grinfo
);
2701 ext4_unlock_group(sb
, i
);
2702 kmem_cache_free(cachep
, grinfo
);
2704 num_meta_group_infos
= (ngroups
+
2705 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2706 EXT4_DESC_PER_BLOCK_BITS(sb
);
2707 for (i
= 0; i
< num_meta_group_infos
; i
++)
2708 kfree(sbi
->s_group_info
[i
]);
2709 ext4_kvfree(sbi
->s_group_info
);
2711 kfree(sbi
->s_mb_offsets
);
2712 kfree(sbi
->s_mb_maxs
);
2713 if (sbi
->s_buddy_cache
)
2714 iput(sbi
->s_buddy_cache
);
2715 if (sbi
->s_mb_stats
) {
2716 ext4_msg(sb
, KERN_INFO
,
2717 "mballoc: %u blocks %u reqs (%u success)",
2718 atomic_read(&sbi
->s_bal_allocated
),
2719 atomic_read(&sbi
->s_bal_reqs
),
2720 atomic_read(&sbi
->s_bal_success
));
2721 ext4_msg(sb
, KERN_INFO
,
2722 "mballoc: %u extents scanned, %u goal hits, "
2723 "%u 2^N hits, %u breaks, %u lost",
2724 atomic_read(&sbi
->s_bal_ex_scanned
),
2725 atomic_read(&sbi
->s_bal_goals
),
2726 atomic_read(&sbi
->s_bal_2orders
),
2727 atomic_read(&sbi
->s_bal_breaks
),
2728 atomic_read(&sbi
->s_mb_lost_chunks
));
2729 ext4_msg(sb
, KERN_INFO
,
2730 "mballoc: %lu generated and it took %Lu",
2731 sbi
->s_mb_buddies_generated
,
2732 sbi
->s_mb_generation_time
);
2733 ext4_msg(sb
, KERN_INFO
,
2734 "mballoc: %u preallocated, %u discarded",
2735 atomic_read(&sbi
->s_mb_preallocated
),
2736 atomic_read(&sbi
->s_mb_discarded
));
2739 free_percpu(sbi
->s_locality_groups
);
2744 static inline int ext4_issue_discard(struct super_block
*sb
,
2745 ext4_group_t block_group
, ext4_grpblk_t cluster
, int count
)
2747 ext4_fsblk_t discard_block
;
2749 discard_block
= (EXT4_C2B(EXT4_SB(sb
), cluster
) +
2750 ext4_group_first_block_no(sb
, block_group
));
2751 count
= EXT4_C2B(EXT4_SB(sb
), count
);
2752 trace_ext4_discard_blocks(sb
,
2753 (unsigned long long) discard_block
, count
);
2754 return sb_issue_discard(sb
, discard_block
, count
, GFP_NOFS
, 0);
2758 * This function is called by the jbd2 layer once the commit has finished,
2759 * so we know we can free the blocks that were released with that commit.
2761 static void ext4_free_data_callback(struct super_block
*sb
,
2762 struct ext4_journal_cb_entry
*jce
,
2765 struct ext4_free_data
*entry
= (struct ext4_free_data
*)jce
;
2766 struct ext4_buddy e4b
;
2767 struct ext4_group_info
*db
;
2768 int err
, count
= 0, count2
= 0;
2770 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2771 entry
->efd_count
, entry
->efd_group
, entry
);
2773 if (test_opt(sb
, DISCARD
)) {
2774 err
= ext4_issue_discard(sb
, entry
->efd_group
,
2775 entry
->efd_start_cluster
,
2777 if (err
&& err
!= -EOPNOTSUPP
)
2778 ext4_msg(sb
, KERN_WARNING
, "discard request in"
2779 " group:%d block:%d count:%d failed"
2780 " with %d", entry
->efd_group
,
2781 entry
->efd_start_cluster
,
2782 entry
->efd_count
, err
);
2785 err
= ext4_mb_load_buddy(sb
, entry
->efd_group
, &e4b
);
2786 /* we expect to find existing buddy because it's pinned */
2791 /* there are blocks to put in buddy to make them really free */
2792 count
+= entry
->efd_count
;
2794 ext4_lock_group(sb
, entry
->efd_group
);
2795 /* Take it out of per group rb tree */
2796 rb_erase(&entry
->efd_node
, &(db
->bb_free_root
));
2797 mb_free_blocks(NULL
, &e4b
, entry
->efd_start_cluster
, entry
->efd_count
);
2800 * Clear the trimmed flag for the group so that the next
2801 * ext4_trim_fs can trim it.
2802 * If the volume is mounted with -o discard, online discard
2803 * is supported and the free blocks will be trimmed online.
2805 if (!test_opt(sb
, DISCARD
))
2806 EXT4_MB_GRP_CLEAR_TRIMMED(db
);
2808 if (!db
->bb_free_root
.rb_node
) {
2809 /* No more items in the per group rb tree
2810 * balance refcounts from ext4_mb_free_metadata()
2812 page_cache_release(e4b
.bd_buddy_page
);
2813 page_cache_release(e4b
.bd_bitmap_page
);
2815 ext4_unlock_group(sb
, entry
->efd_group
);
2816 kmem_cache_free(ext4_free_data_cachep
, entry
);
2817 ext4_mb_unload_buddy(&e4b
);
2819 mb_debug(1, "freed %u blocks in %u structures\n", count
, count2
);
2822 int __init
ext4_init_mballoc(void)
2824 ext4_pspace_cachep
= KMEM_CACHE(ext4_prealloc_space
,
2825 SLAB_RECLAIM_ACCOUNT
);
2826 if (ext4_pspace_cachep
== NULL
)
2829 ext4_ac_cachep
= KMEM_CACHE(ext4_allocation_context
,
2830 SLAB_RECLAIM_ACCOUNT
);
2831 if (ext4_ac_cachep
== NULL
) {
2832 kmem_cache_destroy(ext4_pspace_cachep
);
2836 ext4_free_data_cachep
= KMEM_CACHE(ext4_free_data
,
2837 SLAB_RECLAIM_ACCOUNT
);
2838 if (ext4_free_data_cachep
== NULL
) {
2839 kmem_cache_destroy(ext4_pspace_cachep
);
2840 kmem_cache_destroy(ext4_ac_cachep
);
2846 void ext4_exit_mballoc(void)
2849 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2850 * before destroying the slab cache.
2853 kmem_cache_destroy(ext4_pspace_cachep
);
2854 kmem_cache_destroy(ext4_ac_cachep
);
2855 kmem_cache_destroy(ext4_free_data_cachep
);
2856 ext4_groupinfo_destroy_slabs();
2861 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2862 * Returns 0 if success or error code
2864 static noinline_for_stack
int
2865 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2866 handle_t
*handle
, unsigned int reserv_clstrs
)
2868 struct buffer_head
*bitmap_bh
= NULL
;
2869 struct ext4_group_desc
*gdp
;
2870 struct buffer_head
*gdp_bh
;
2871 struct ext4_sb_info
*sbi
;
2872 struct super_block
*sb
;
2876 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2877 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2883 bitmap_bh
= ext4_read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2887 BUFFER_TRACE(bitmap_bh
, "getting write access");
2888 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2893 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2897 ext4_debug("using block group %u(%d)\n", ac
->ac_b_ex
.fe_group
,
2898 ext4_free_group_clusters(sb
, gdp
));
2900 BUFFER_TRACE(gdp_bh
, "get_write_access");
2901 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2905 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
2907 len
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
2908 if (!ext4_data_block_valid(sbi
, block
, len
)) {
2909 ext4_error(sb
, "Allocating blocks %llu-%llu which overlap "
2910 "fs metadata", block
, block
+len
);
2911 /* File system mounted not to panic on error
2912 * Fix the bitmap and repeat the block allocation
2913 * We leak some of the blocks here.
2915 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2916 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2917 ac
->ac_b_ex
.fe_len
);
2918 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2919 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2925 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2926 #ifdef AGGRESSIVE_CHECK
2929 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2930 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2931 bitmap_bh
->b_data
));
2935 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2936 ac
->ac_b_ex
.fe_len
);
2937 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2938 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2939 ext4_free_group_clusters_set(sb
, gdp
,
2940 ext4_free_clusters_after_init(sb
,
2941 ac
->ac_b_ex
.fe_group
, gdp
));
2943 len
= ext4_free_group_clusters(sb
, gdp
) - ac
->ac_b_ex
.fe_len
;
2944 ext4_free_group_clusters_set(sb
, gdp
, len
);
2945 ext4_block_bitmap_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
, bitmap_bh
);
2946 ext4_group_desc_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
);
2948 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2949 percpu_counter_sub(&sbi
->s_freeclusters_counter
, ac
->ac_b_ex
.fe_len
);
2951 * Now reduce the dirty block count also. Should not go negative
2953 if (!(ac
->ac_flags
& EXT4_MB_DELALLOC_RESERVED
))
2954 /* release all the reserved blocks if non delalloc */
2955 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
2958 if (sbi
->s_log_groups_per_flex
) {
2959 ext4_group_t flex_group
= ext4_flex_group(sbi
,
2960 ac
->ac_b_ex
.fe_group
);
2961 atomic64_sub(ac
->ac_b_ex
.fe_len
,
2962 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
2965 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2968 err
= ext4_handle_dirty_metadata(handle
, NULL
, gdp_bh
);
2976 * here we normalize request for locality group
2977 * Group request are normalized to s_mb_group_prealloc, which goes to
2978 * s_strip if we set the same via mount option.
2979 * s_mb_group_prealloc can be configured via
2980 * /sys/fs/ext4/<partition>/mb_group_prealloc
2982 * XXX: should we try to preallocate more than the group has now?
2984 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2986 struct super_block
*sb
= ac
->ac_sb
;
2987 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2990 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2991 mb_debug(1, "#%u: goal %u blocks for locality group\n",
2992 current
->pid
, ac
->ac_g_ex
.fe_len
);
2996 * Normalization means making request better in terms of
2997 * size and alignment
2999 static noinline_for_stack
void
3000 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
3001 struct ext4_allocation_request
*ar
)
3003 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3006 loff_t size
, start_off
;
3007 loff_t orig_size __maybe_unused
;
3009 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3010 struct ext4_prealloc_space
*pa
;
3012 /* do normalize only data requests, metadata requests
3013 do not need preallocation */
3014 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3017 /* sometime caller may want exact blocks */
3018 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3021 /* caller may indicate that preallocation isn't
3022 * required (it's a tail, for example) */
3023 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
3026 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
3027 ext4_mb_normalize_group_request(ac
);
3031 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3033 /* first, let's learn actual file size
3034 * given current request is allocated */
3035 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
3036 size
= size
<< bsbits
;
3037 if (size
< i_size_read(ac
->ac_inode
))
3038 size
= i_size_read(ac
->ac_inode
);
3041 /* max size of free chunks */
3044 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3045 (req <= (size) || max <= (chunk_size))
3047 /* first, try to predict filesize */
3048 /* XXX: should this table be tunable? */
3050 if (size
<= 16 * 1024) {
3052 } else if (size
<= 32 * 1024) {
3054 } else if (size
<= 64 * 1024) {
3056 } else if (size
<= 128 * 1024) {
3058 } else if (size
<= 256 * 1024) {
3060 } else if (size
<= 512 * 1024) {
3062 } else if (size
<= 1024 * 1024) {
3064 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
3065 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3066 (21 - bsbits
)) << 21;
3067 size
= 2 * 1024 * 1024;
3068 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
3069 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3070 (22 - bsbits
)) << 22;
3071 size
= 4 * 1024 * 1024;
3072 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
3073 (8<<20)>>bsbits
, max
, 8 * 1024)) {
3074 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3075 (23 - bsbits
)) << 23;
3076 size
= 8 * 1024 * 1024;
3078 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
3079 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
3081 size
= size
>> bsbits
;
3082 start
= start_off
>> bsbits
;
3084 /* don't cover already allocated blocks in selected range */
3085 if (ar
->pleft
&& start
<= ar
->lleft
) {
3086 size
-= ar
->lleft
+ 1 - start
;
3087 start
= ar
->lleft
+ 1;
3089 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
3090 size
-= start
+ size
- ar
->lright
;
3094 /* check we don't cross already preallocated blocks */
3096 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3101 spin_lock(&pa
->pa_lock
);
3102 if (pa
->pa_deleted
) {
3103 spin_unlock(&pa
->pa_lock
);
3107 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3110 /* PA must not overlap original request */
3111 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
3112 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
3114 /* skip PAs this normalized request doesn't overlap with */
3115 if (pa
->pa_lstart
>= end
|| pa_end
<= start
) {
3116 spin_unlock(&pa
->pa_lock
);
3119 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
3121 /* adjust start or end to be adjacent to this pa */
3122 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
3123 BUG_ON(pa_end
< start
);
3125 } else if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
3126 BUG_ON(pa
->pa_lstart
> end
);
3127 end
= pa
->pa_lstart
;
3129 spin_unlock(&pa
->pa_lock
);
3134 /* XXX: extra loop to check we really don't overlap preallocations */
3136 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3139 spin_lock(&pa
->pa_lock
);
3140 if (pa
->pa_deleted
== 0) {
3141 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3143 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3145 spin_unlock(&pa
->pa_lock
);
3149 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3150 start
> ac
->ac_o_ex
.fe_logical
) {
3151 ext4_msg(ac
->ac_sb
, KERN_ERR
,
3152 "start %lu, size %lu, fe_logical %lu",
3153 (unsigned long) start
, (unsigned long) size
,
3154 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3156 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3157 start
> ac
->ac_o_ex
.fe_logical
);
3158 BUG_ON(size
<= 0 || size
> EXT4_BLOCKS_PER_GROUP(ac
->ac_sb
));
3160 /* now prepare goal request */
3162 /* XXX: is it better to align blocks WRT to logical
3163 * placement or satisfy big request as is */
3164 ac
->ac_g_ex
.fe_logical
= start
;
3165 ac
->ac_g_ex
.fe_len
= EXT4_NUM_B2C(sbi
, size
);
3167 /* define goal start in order to merge */
3168 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3169 /* merge to the right */
3170 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3171 &ac
->ac_f_ex
.fe_group
,
3172 &ac
->ac_f_ex
.fe_start
);
3173 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3175 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3176 /* merge to the left */
3177 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3178 &ac
->ac_f_ex
.fe_group
,
3179 &ac
->ac_f_ex
.fe_start
);
3180 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3183 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3184 (unsigned) orig_size
, (unsigned) start
);
3187 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3189 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3191 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3192 atomic_inc(&sbi
->s_bal_reqs
);
3193 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3194 if (ac
->ac_b_ex
.fe_len
>= ac
->ac_o_ex
.fe_len
)
3195 atomic_inc(&sbi
->s_bal_success
);
3196 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3197 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3198 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3199 atomic_inc(&sbi
->s_bal_goals
);
3200 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3201 atomic_inc(&sbi
->s_bal_breaks
);
3204 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
)
3205 trace_ext4_mballoc_alloc(ac
);
3207 trace_ext4_mballoc_prealloc(ac
);
3211 * Called on failure; free up any blocks from the inode PA for this
3212 * context. We don't need this for MB_GROUP_PA because we only change
3213 * pa_free in ext4_mb_release_context(), but on failure, we've already
3214 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3216 static void ext4_discard_allocated_blocks(struct ext4_allocation_context
*ac
)
3218 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
3220 if (pa
&& pa
->pa_type
== MB_INODE_PA
)
3221 pa
->pa_free
+= ac
->ac_b_ex
.fe_len
;
3225 * use blocks preallocated to inode
3227 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3228 struct ext4_prealloc_space
*pa
)
3230 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3235 /* found preallocated blocks, use them */
3236 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3237 end
= min(pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
),
3238 start
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
));
3239 len
= EXT4_NUM_B2C(sbi
, end
- start
);
3240 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3241 &ac
->ac_b_ex
.fe_start
);
3242 ac
->ac_b_ex
.fe_len
= len
;
3243 ac
->ac_status
= AC_STATUS_FOUND
;
3246 BUG_ON(start
< pa
->pa_pstart
);
3247 BUG_ON(end
> pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
));
3248 BUG_ON(pa
->pa_free
< len
);
3251 mb_debug(1, "use %llu/%u from inode pa %p\n", start
, len
, pa
);
3255 * use blocks preallocated to locality group
3257 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3258 struct ext4_prealloc_space
*pa
)
3260 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3262 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3263 &ac
->ac_b_ex
.fe_group
,
3264 &ac
->ac_b_ex
.fe_start
);
3265 ac
->ac_b_ex
.fe_len
= len
;
3266 ac
->ac_status
= AC_STATUS_FOUND
;
3269 /* we don't correct pa_pstart or pa_plen here to avoid
3270 * possible race when the group is being loaded concurrently
3271 * instead we correct pa later, after blocks are marked
3272 * in on-disk bitmap -- see ext4_mb_release_context()
3273 * Other CPUs are prevented from allocating from this pa by lg_mutex
3275 mb_debug(1, "use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3279 * Return the prealloc space that have minimal distance
3280 * from the goal block. @cpa is the prealloc
3281 * space that is having currently known minimal distance
3282 * from the goal block.
3284 static struct ext4_prealloc_space
*
3285 ext4_mb_check_group_pa(ext4_fsblk_t goal_block
,
3286 struct ext4_prealloc_space
*pa
,
3287 struct ext4_prealloc_space
*cpa
)
3289 ext4_fsblk_t cur_distance
, new_distance
;
3292 atomic_inc(&pa
->pa_count
);
3295 cur_distance
= abs(goal_block
- cpa
->pa_pstart
);
3296 new_distance
= abs(goal_block
- pa
->pa_pstart
);
3298 if (cur_distance
<= new_distance
)
3301 /* drop the previous reference */
3302 atomic_dec(&cpa
->pa_count
);
3303 atomic_inc(&pa
->pa_count
);
3308 * search goal blocks in preallocated space
3310 static noinline_for_stack
int
3311 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3313 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3315 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3316 struct ext4_locality_group
*lg
;
3317 struct ext4_prealloc_space
*pa
, *cpa
= NULL
;
3318 ext4_fsblk_t goal_block
;
3320 /* only data can be preallocated */
3321 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3324 /* first, try per-file preallocation */
3326 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3328 /* all fields in this condition don't change,
3329 * so we can skip locking for them */
3330 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3331 ac
->ac_o_ex
.fe_logical
>= (pa
->pa_lstart
+
3332 EXT4_C2B(sbi
, pa
->pa_len
)))
3335 /* non-extent files can't have physical blocks past 2^32 */
3336 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)) &&
3337 (pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
) >
3338 EXT4_MAX_BLOCK_FILE_PHYS
))
3341 /* found preallocated blocks, use them */
3342 spin_lock(&pa
->pa_lock
);
3343 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3344 atomic_inc(&pa
->pa_count
);
3345 ext4_mb_use_inode_pa(ac
, pa
);
3346 spin_unlock(&pa
->pa_lock
);
3347 ac
->ac_criteria
= 10;
3351 spin_unlock(&pa
->pa_lock
);
3355 /* can we use group allocation? */
3356 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3359 /* inode may have no locality group for some reason */
3363 order
= fls(ac
->ac_o_ex
.fe_len
) - 1;
3364 if (order
> PREALLOC_TB_SIZE
- 1)
3365 /* The max size of hash table is PREALLOC_TB_SIZE */
3366 order
= PREALLOC_TB_SIZE
- 1;
3368 goal_block
= ext4_grp_offs_to_block(ac
->ac_sb
, &ac
->ac_g_ex
);
3370 * search for the prealloc space that is having
3371 * minimal distance from the goal block.
3373 for (i
= order
; i
< PREALLOC_TB_SIZE
; i
++) {
3375 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[i
],
3377 spin_lock(&pa
->pa_lock
);
3378 if (pa
->pa_deleted
== 0 &&
3379 pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3381 cpa
= ext4_mb_check_group_pa(goal_block
,
3384 spin_unlock(&pa
->pa_lock
);
3389 ext4_mb_use_group_pa(ac
, cpa
);
3390 ac
->ac_criteria
= 20;
3397 * the function goes through all block freed in the group
3398 * but not yet committed and marks them used in in-core bitmap.
3399 * buddy must be generated from this bitmap
3400 * Need to be called with the ext4 group lock held
3402 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
3406 struct ext4_group_info
*grp
;
3407 struct ext4_free_data
*entry
;
3409 grp
= ext4_get_group_info(sb
, group
);
3410 n
= rb_first(&(grp
->bb_free_root
));
3413 entry
= rb_entry(n
, struct ext4_free_data
, efd_node
);
3414 ext4_set_bits(bitmap
, entry
->efd_start_cluster
, entry
->efd_count
);
3421 * the function goes through all preallocation in this group and marks them
3422 * used in in-core bitmap. buddy must be generated from this bitmap
3423 * Need to be called with ext4 group lock held
3425 static noinline_for_stack
3426 void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3429 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3430 struct ext4_prealloc_space
*pa
;
3431 struct list_head
*cur
;
3432 ext4_group_t groupnr
;
3433 ext4_grpblk_t start
;
3434 int preallocated
= 0;
3437 /* all form of preallocation discards first load group,
3438 * so the only competing code is preallocation use.
3439 * we don't need any locking here
3440 * notice we do NOT ignore preallocations with pa_deleted
3441 * otherwise we could leave used blocks available for
3442 * allocation in buddy when concurrent ext4_mb_put_pa()
3443 * is dropping preallocation
3445 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3446 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3447 spin_lock(&pa
->pa_lock
);
3448 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3451 spin_unlock(&pa
->pa_lock
);
3452 if (unlikely(len
== 0))
3454 BUG_ON(groupnr
!= group
);
3455 ext4_set_bits(bitmap
, start
, len
);
3456 preallocated
+= len
;
3458 mb_debug(1, "prellocated %u for group %u\n", preallocated
, group
);
3461 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3463 struct ext4_prealloc_space
*pa
;
3464 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3466 BUG_ON(atomic_read(&pa
->pa_count
));
3467 BUG_ON(pa
->pa_deleted
== 0);
3468 kmem_cache_free(ext4_pspace_cachep
, pa
);
3472 * drops a reference to preallocated space descriptor
3473 * if this was the last reference and the space is consumed
3475 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3476 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3479 ext4_fsblk_t grp_blk
;
3481 /* in this short window concurrent discard can set pa_deleted */
3482 spin_lock(&pa
->pa_lock
);
3483 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0) {
3484 spin_unlock(&pa
->pa_lock
);
3488 if (pa
->pa_deleted
== 1) {
3489 spin_unlock(&pa
->pa_lock
);
3494 spin_unlock(&pa
->pa_lock
);
3496 grp_blk
= pa
->pa_pstart
;
3498 * If doing group-based preallocation, pa_pstart may be in the
3499 * next group when pa is used up
3501 if (pa
->pa_type
== MB_GROUP_PA
)
3504 grp
= ext4_get_group_number(sb
, grp_blk
);
3509 * P1 (buddy init) P2 (regular allocation)
3510 * find block B in PA
3511 * copy on-disk bitmap to buddy
3512 * mark B in on-disk bitmap
3513 * drop PA from group
3514 * mark all PAs in buddy
3516 * thus, P1 initializes buddy with B available. to prevent this
3517 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3520 ext4_lock_group(sb
, grp
);
3521 list_del(&pa
->pa_group_list
);
3522 ext4_unlock_group(sb
, grp
);
3524 spin_lock(pa
->pa_obj_lock
);
3525 list_del_rcu(&pa
->pa_inode_list
);
3526 spin_unlock(pa
->pa_obj_lock
);
3528 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3532 * creates new preallocated space for given inode
3534 static noinline_for_stack
int
3535 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3537 struct super_block
*sb
= ac
->ac_sb
;
3538 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3539 struct ext4_prealloc_space
*pa
;
3540 struct ext4_group_info
*grp
;
3541 struct ext4_inode_info
*ei
;
3543 /* preallocate only when found space is larger then requested */
3544 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3545 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3546 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3548 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3552 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3558 /* we can't allocate as much as normalizer wants.
3559 * so, found space must get proper lstart
3560 * to cover original request */
3561 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3562 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3564 /* we're limited by original request in that
3565 * logical block must be covered any way
3566 * winl is window we can move our chunk within */
3567 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3569 /* also, we should cover whole original request */
3570 wins
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
);
3572 /* the smallest one defines real window */
3573 win
= min(winl
, wins
);
3575 offs
= ac
->ac_o_ex
.fe_logical
%
3576 EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
3577 if (offs
&& offs
< win
)
3580 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
-
3581 EXT4_NUM_B2C(sbi
, win
);
3582 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3583 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3586 /* preallocation can change ac_b_ex, thus we store actually
3587 * allocated blocks for history */
3588 ac
->ac_f_ex
= ac
->ac_b_ex
;
3590 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3591 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3592 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3593 pa
->pa_free
= pa
->pa_len
;
3594 atomic_set(&pa
->pa_count
, 1);
3595 spin_lock_init(&pa
->pa_lock
);
3596 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3597 INIT_LIST_HEAD(&pa
->pa_group_list
);
3599 pa
->pa_type
= MB_INODE_PA
;
3601 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa
,
3602 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3603 trace_ext4_mb_new_inode_pa(ac
, pa
);
3605 ext4_mb_use_inode_pa(ac
, pa
);
3606 atomic_add(pa
->pa_free
, &sbi
->s_mb_preallocated
);
3608 ei
= EXT4_I(ac
->ac_inode
);
3609 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3611 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3612 pa
->pa_inode
= ac
->ac_inode
;
3614 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3615 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3616 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3618 spin_lock(pa
->pa_obj_lock
);
3619 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3620 spin_unlock(pa
->pa_obj_lock
);
3626 * creates new preallocated space for locality group inodes belongs to
3628 static noinline_for_stack
int
3629 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3631 struct super_block
*sb
= ac
->ac_sb
;
3632 struct ext4_locality_group
*lg
;
3633 struct ext4_prealloc_space
*pa
;
3634 struct ext4_group_info
*grp
;
3636 /* preallocate only when found space is larger then requested */
3637 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3638 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3639 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3641 BUG_ON(ext4_pspace_cachep
== NULL
);
3642 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3646 /* preallocation can change ac_b_ex, thus we store actually
3647 * allocated blocks for history */
3648 ac
->ac_f_ex
= ac
->ac_b_ex
;
3650 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3651 pa
->pa_lstart
= pa
->pa_pstart
;
3652 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3653 pa
->pa_free
= pa
->pa_len
;
3654 atomic_set(&pa
->pa_count
, 1);
3655 spin_lock_init(&pa
->pa_lock
);
3656 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3657 INIT_LIST_HEAD(&pa
->pa_group_list
);
3659 pa
->pa_type
= MB_GROUP_PA
;
3661 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa
,
3662 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3663 trace_ext4_mb_new_group_pa(ac
, pa
);
3665 ext4_mb_use_group_pa(ac
, pa
);
3666 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3668 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3672 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3673 pa
->pa_inode
= NULL
;
3675 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3676 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3677 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3680 * We will later add the new pa to the right bucket
3681 * after updating the pa_free in ext4_mb_release_context
3686 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3690 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3691 err
= ext4_mb_new_group_pa(ac
);
3693 err
= ext4_mb_new_inode_pa(ac
);
3698 * finds all unused blocks in on-disk bitmap, frees them in
3699 * in-core bitmap and buddy.
3700 * @pa must be unlinked from inode and group lists, so that
3701 * nobody else can find/use it.
3702 * the caller MUST hold group/inode locks.
3703 * TODO: optimize the case when there are no in-core structures yet
3705 static noinline_for_stack
int
3706 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3707 struct ext4_prealloc_space
*pa
)
3709 struct super_block
*sb
= e4b
->bd_sb
;
3710 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3715 unsigned long long grp_blk_start
;
3719 BUG_ON(pa
->pa_deleted
== 0);
3720 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3721 grp_blk_start
= pa
->pa_pstart
- EXT4_C2B(sbi
, bit
);
3722 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3723 end
= bit
+ pa
->pa_len
;
3726 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3729 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3730 mb_debug(1, " free preallocated %u/%u in group %u\n",
3731 (unsigned) ext4_group_first_block_no(sb
, group
) + bit
,
3732 (unsigned) next
- bit
, (unsigned) group
);
3735 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, next
- bit
);
3736 trace_ext4_mb_release_inode_pa(pa
, (grp_blk_start
+
3737 EXT4_C2B(sbi
, bit
)),
3739 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3742 if (free
!= pa
->pa_free
) {
3743 ext4_msg(e4b
->bd_sb
, KERN_CRIT
,
3744 "pa %p: logic %lu, phys. %lu, len %lu",
3745 pa
, (unsigned long) pa
->pa_lstart
,
3746 (unsigned long) pa
->pa_pstart
,
3747 (unsigned long) pa
->pa_len
);
3748 ext4_grp_locked_error(sb
, group
, 0, 0, "free %u, pa_free %u",
3751 * pa is already deleted so we use the value obtained
3752 * from the bitmap and continue.
3755 atomic_add(free
, &sbi
->s_mb_discarded
);
3760 static noinline_for_stack
int
3761 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3762 struct ext4_prealloc_space
*pa
)
3764 struct super_block
*sb
= e4b
->bd_sb
;
3768 trace_ext4_mb_release_group_pa(sb
, pa
);
3769 BUG_ON(pa
->pa_deleted
== 0);
3770 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3771 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3772 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3773 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3774 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, pa
->pa_len
);
3780 * releases all preallocations in given group
3782 * first, we need to decide discard policy:
3783 * - when do we discard
3785 * - how many do we discard
3786 * 1) how many requested
3788 static noinline_for_stack
int
3789 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3790 ext4_group_t group
, int needed
)
3792 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3793 struct buffer_head
*bitmap_bh
= NULL
;
3794 struct ext4_prealloc_space
*pa
, *tmp
;
3795 struct list_head list
;
3796 struct ext4_buddy e4b
;
3801 mb_debug(1, "discard preallocation for group %u\n", group
);
3803 if (list_empty(&grp
->bb_prealloc_list
))
3806 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3807 if (bitmap_bh
== NULL
) {
3808 ext4_error(sb
, "Error reading block bitmap for %u", group
);
3812 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3814 ext4_error(sb
, "Error loading buddy information for %u", group
);
3820 needed
= EXT4_CLUSTERS_PER_GROUP(sb
) + 1;
3822 INIT_LIST_HEAD(&list
);
3824 ext4_lock_group(sb
, group
);
3825 list_for_each_entry_safe(pa
, tmp
,
3826 &grp
->bb_prealloc_list
, pa_group_list
) {
3827 spin_lock(&pa
->pa_lock
);
3828 if (atomic_read(&pa
->pa_count
)) {
3829 spin_unlock(&pa
->pa_lock
);
3833 if (pa
->pa_deleted
) {
3834 spin_unlock(&pa
->pa_lock
);
3838 /* seems this one can be freed ... */
3841 /* we can trust pa_free ... */
3842 free
+= pa
->pa_free
;
3844 spin_unlock(&pa
->pa_lock
);
3846 list_del(&pa
->pa_group_list
);
3847 list_add(&pa
->u
.pa_tmp_list
, &list
);
3850 /* if we still need more blocks and some PAs were used, try again */
3851 if (free
< needed
&& busy
) {
3853 ext4_unlock_group(sb
, group
);
3858 /* found anything to free? */
3859 if (list_empty(&list
)) {
3864 /* now free all selected PAs */
3865 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3867 /* remove from object (inode or locality group) */
3868 spin_lock(pa
->pa_obj_lock
);
3869 list_del_rcu(&pa
->pa_inode_list
);
3870 spin_unlock(pa
->pa_obj_lock
);
3872 if (pa
->pa_type
== MB_GROUP_PA
)
3873 ext4_mb_release_group_pa(&e4b
, pa
);
3875 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3877 list_del(&pa
->u
.pa_tmp_list
);
3878 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3882 ext4_unlock_group(sb
, group
);
3883 ext4_mb_unload_buddy(&e4b
);
3889 * releases all non-used preallocated blocks for given inode
3891 * It's important to discard preallocations under i_data_sem
3892 * We don't want another block to be served from the prealloc
3893 * space when we are discarding the inode prealloc space.
3895 * FIXME!! Make sure it is valid at all the call sites
3897 void ext4_discard_preallocations(struct inode
*inode
)
3899 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3900 struct super_block
*sb
= inode
->i_sb
;
3901 struct buffer_head
*bitmap_bh
= NULL
;
3902 struct ext4_prealloc_space
*pa
, *tmp
;
3903 ext4_group_t group
= 0;
3904 struct list_head list
;
3905 struct ext4_buddy e4b
;
3908 if (!S_ISREG(inode
->i_mode
)) {
3909 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3913 mb_debug(1, "discard preallocation for inode %lu\n", inode
->i_ino
);
3914 trace_ext4_discard_preallocations(inode
);
3916 INIT_LIST_HEAD(&list
);
3919 /* first, collect all pa's in the inode */
3920 spin_lock(&ei
->i_prealloc_lock
);
3921 while (!list_empty(&ei
->i_prealloc_list
)) {
3922 pa
= list_entry(ei
->i_prealloc_list
.next
,
3923 struct ext4_prealloc_space
, pa_inode_list
);
3924 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3925 spin_lock(&pa
->pa_lock
);
3926 if (atomic_read(&pa
->pa_count
)) {
3927 /* this shouldn't happen often - nobody should
3928 * use preallocation while we're discarding it */
3929 spin_unlock(&pa
->pa_lock
);
3930 spin_unlock(&ei
->i_prealloc_lock
);
3931 ext4_msg(sb
, KERN_ERR
,
3932 "uh-oh! used pa while discarding");
3934 schedule_timeout_uninterruptible(HZ
);
3938 if (pa
->pa_deleted
== 0) {
3940 spin_unlock(&pa
->pa_lock
);
3941 list_del_rcu(&pa
->pa_inode_list
);
3942 list_add(&pa
->u
.pa_tmp_list
, &list
);
3946 /* someone is deleting pa right now */
3947 spin_unlock(&pa
->pa_lock
);
3948 spin_unlock(&ei
->i_prealloc_lock
);
3950 /* we have to wait here because pa_deleted
3951 * doesn't mean pa is already unlinked from
3952 * the list. as we might be called from
3953 * ->clear_inode() the inode will get freed
3954 * and concurrent thread which is unlinking
3955 * pa from inode's list may access already
3956 * freed memory, bad-bad-bad */
3958 /* XXX: if this happens too often, we can
3959 * add a flag to force wait only in case
3960 * of ->clear_inode(), but not in case of
3961 * regular truncate */
3962 schedule_timeout_uninterruptible(HZ
);
3965 spin_unlock(&ei
->i_prealloc_lock
);
3967 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3968 BUG_ON(pa
->pa_type
!= MB_INODE_PA
);
3969 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
3971 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3973 ext4_error(sb
, "Error loading buddy information for %u",
3978 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3979 if (bitmap_bh
== NULL
) {
3980 ext4_error(sb
, "Error reading block bitmap for %u",
3982 ext4_mb_unload_buddy(&e4b
);
3986 ext4_lock_group(sb
, group
);
3987 list_del(&pa
->pa_group_list
);
3988 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3989 ext4_unlock_group(sb
, group
);
3991 ext4_mb_unload_buddy(&e4b
);
3994 list_del(&pa
->u
.pa_tmp_list
);
3995 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3999 #ifdef CONFIG_EXT4_DEBUG
4000 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4002 struct super_block
*sb
= ac
->ac_sb
;
4003 ext4_group_t ngroups
, i
;
4005 if (!ext4_mballoc_debug
||
4006 (EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
))
4009 ext4_msg(ac
->ac_sb
, KERN_ERR
, "Can't allocate:"
4010 " Allocation context details:");
4011 ext4_msg(ac
->ac_sb
, KERN_ERR
, "status %d flags %d",
4012 ac
->ac_status
, ac
->ac_flags
);
4013 ext4_msg(ac
->ac_sb
, KERN_ERR
, "orig %lu/%lu/%lu@%lu, "
4014 "goal %lu/%lu/%lu@%lu, "
4015 "best %lu/%lu/%lu@%lu cr %d",
4016 (unsigned long)ac
->ac_o_ex
.fe_group
,
4017 (unsigned long)ac
->ac_o_ex
.fe_start
,
4018 (unsigned long)ac
->ac_o_ex
.fe_len
,
4019 (unsigned long)ac
->ac_o_ex
.fe_logical
,
4020 (unsigned long)ac
->ac_g_ex
.fe_group
,
4021 (unsigned long)ac
->ac_g_ex
.fe_start
,
4022 (unsigned long)ac
->ac_g_ex
.fe_len
,
4023 (unsigned long)ac
->ac_g_ex
.fe_logical
,
4024 (unsigned long)ac
->ac_b_ex
.fe_group
,
4025 (unsigned long)ac
->ac_b_ex
.fe_start
,
4026 (unsigned long)ac
->ac_b_ex
.fe_len
,
4027 (unsigned long)ac
->ac_b_ex
.fe_logical
,
4028 (int)ac
->ac_criteria
);
4029 ext4_msg(ac
->ac_sb
, KERN_ERR
, "%d found", ac
->ac_found
);
4030 ext4_msg(ac
->ac_sb
, KERN_ERR
, "groups: ");
4031 ngroups
= ext4_get_groups_count(sb
);
4032 for (i
= 0; i
< ngroups
; i
++) {
4033 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
4034 struct ext4_prealloc_space
*pa
;
4035 ext4_grpblk_t start
;
4036 struct list_head
*cur
;
4037 ext4_lock_group(sb
, i
);
4038 list_for_each(cur
, &grp
->bb_prealloc_list
) {
4039 pa
= list_entry(cur
, struct ext4_prealloc_space
,
4041 spin_lock(&pa
->pa_lock
);
4042 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
4044 spin_unlock(&pa
->pa_lock
);
4045 printk(KERN_ERR
"PA:%u:%d:%u \n", i
,
4048 ext4_unlock_group(sb
, i
);
4050 if (grp
->bb_free
== 0)
4052 printk(KERN_ERR
"%u: %d/%d \n",
4053 i
, grp
->bb_free
, grp
->bb_fragments
);
4055 printk(KERN_ERR
"\n");
4058 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4065 * We use locality group preallocation for small size file. The size of the
4066 * file is determined by the current size or the resulting size after
4067 * allocation which ever is larger
4069 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4071 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
4073 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4074 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
4077 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
4080 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
4083 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
4084 isize
= (i_size_read(ac
->ac_inode
) + ac
->ac_sb
->s_blocksize
- 1)
4087 if ((size
== isize
) &&
4088 !ext4_fs_is_busy(sbi
) &&
4089 (atomic_read(&ac
->ac_inode
->i_writecount
) == 0)) {
4090 ac
->ac_flags
|= EXT4_MB_HINT_NOPREALLOC
;
4094 if (sbi
->s_mb_group_prealloc
<= 0) {
4095 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4099 /* don't use group allocation for large files */
4100 size
= max(size
, isize
);
4101 if (size
> sbi
->s_mb_stream_request
) {
4102 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4106 BUG_ON(ac
->ac_lg
!= NULL
);
4108 * locality group prealloc space are per cpu. The reason for having
4109 * per cpu locality group is to reduce the contention between block
4110 * request from multiple CPUs.
4112 ac
->ac_lg
= __this_cpu_ptr(sbi
->s_locality_groups
);
4114 /* we're going to use group allocation */
4115 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
4117 /* serialize all allocations in the group */
4118 mutex_lock(&ac
->ac_lg
->lg_mutex
);
4121 static noinline_for_stack
int
4122 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
4123 struct ext4_allocation_request
*ar
)
4125 struct super_block
*sb
= ar
->inode
->i_sb
;
4126 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4127 struct ext4_super_block
*es
= sbi
->s_es
;
4131 ext4_grpblk_t block
;
4133 /* we can't allocate > group size */
4136 /* just a dirty hack to filter too big requests */
4137 if (len
>= EXT4_CLUSTERS_PER_GROUP(sb
))
4138 len
= EXT4_CLUSTERS_PER_GROUP(sb
);
4140 /* start searching from the goal */
4142 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
4143 goal
>= ext4_blocks_count(es
))
4144 goal
= le32_to_cpu(es
->s_first_data_block
);
4145 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
4147 /* set up allocation goals */
4148 ac
->ac_b_ex
.fe_logical
= EXT4_LBLK_CMASK(sbi
, ar
->logical
);
4149 ac
->ac_status
= AC_STATUS_CONTINUE
;
4151 ac
->ac_inode
= ar
->inode
;
4152 ac
->ac_o_ex
.fe_logical
= ac
->ac_b_ex
.fe_logical
;
4153 ac
->ac_o_ex
.fe_group
= group
;
4154 ac
->ac_o_ex
.fe_start
= block
;
4155 ac
->ac_o_ex
.fe_len
= len
;
4156 ac
->ac_g_ex
= ac
->ac_o_ex
;
4157 ac
->ac_flags
= ar
->flags
;
4159 /* we have to define context: we'll we work with a file or
4160 * locality group. this is a policy, actually */
4161 ext4_mb_group_or_file(ac
);
4163 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4164 "left: %u/%u, right %u/%u to %swritable\n",
4165 (unsigned) ar
->len
, (unsigned) ar
->logical
,
4166 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
4167 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
4168 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
4169 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
4174 static noinline_for_stack
void
4175 ext4_mb_discard_lg_preallocations(struct super_block
*sb
,
4176 struct ext4_locality_group
*lg
,
4177 int order
, int total_entries
)
4179 ext4_group_t group
= 0;
4180 struct ext4_buddy e4b
;
4181 struct list_head discard_list
;
4182 struct ext4_prealloc_space
*pa
, *tmp
;
4184 mb_debug(1, "discard locality group preallocation\n");
4186 INIT_LIST_HEAD(&discard_list
);
4188 spin_lock(&lg
->lg_prealloc_lock
);
4189 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[order
],
4191 spin_lock(&pa
->pa_lock
);
4192 if (atomic_read(&pa
->pa_count
)) {
4194 * This is the pa that we just used
4195 * for block allocation. So don't
4198 spin_unlock(&pa
->pa_lock
);
4201 if (pa
->pa_deleted
) {
4202 spin_unlock(&pa
->pa_lock
);
4205 /* only lg prealloc space */
4206 BUG_ON(pa
->pa_type
!= MB_GROUP_PA
);
4208 /* seems this one can be freed ... */
4210 spin_unlock(&pa
->pa_lock
);
4212 list_del_rcu(&pa
->pa_inode_list
);
4213 list_add(&pa
->u
.pa_tmp_list
, &discard_list
);
4216 if (total_entries
<= 5) {
4218 * we want to keep only 5 entries
4219 * allowing it to grow to 8. This
4220 * mak sure we don't call discard
4221 * soon for this list.
4226 spin_unlock(&lg
->lg_prealloc_lock
);
4228 list_for_each_entry_safe(pa
, tmp
, &discard_list
, u
.pa_tmp_list
) {
4230 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
4231 if (ext4_mb_load_buddy(sb
, group
, &e4b
)) {
4232 ext4_error(sb
, "Error loading buddy information for %u",
4236 ext4_lock_group(sb
, group
);
4237 list_del(&pa
->pa_group_list
);
4238 ext4_mb_release_group_pa(&e4b
, pa
);
4239 ext4_unlock_group(sb
, group
);
4241 ext4_mb_unload_buddy(&e4b
);
4242 list_del(&pa
->u
.pa_tmp_list
);
4243 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4248 * We have incremented pa_count. So it cannot be freed at this
4249 * point. Also we hold lg_mutex. So no parallel allocation is
4250 * possible from this lg. That means pa_free cannot be updated.
4252 * A parallel ext4_mb_discard_group_preallocations is possible.
4253 * which can cause the lg_prealloc_list to be updated.
4256 static void ext4_mb_add_n_trim(struct ext4_allocation_context
*ac
)
4258 int order
, added
= 0, lg_prealloc_count
= 1;
4259 struct super_block
*sb
= ac
->ac_sb
;
4260 struct ext4_locality_group
*lg
= ac
->ac_lg
;
4261 struct ext4_prealloc_space
*tmp_pa
, *pa
= ac
->ac_pa
;
4263 order
= fls(pa
->pa_free
) - 1;
4264 if (order
> PREALLOC_TB_SIZE
- 1)
4265 /* The max size of hash table is PREALLOC_TB_SIZE */
4266 order
= PREALLOC_TB_SIZE
- 1;
4267 /* Add the prealloc space to lg */
4268 spin_lock(&lg
->lg_prealloc_lock
);
4269 list_for_each_entry_rcu(tmp_pa
, &lg
->lg_prealloc_list
[order
],
4271 spin_lock(&tmp_pa
->pa_lock
);
4272 if (tmp_pa
->pa_deleted
) {
4273 spin_unlock(&tmp_pa
->pa_lock
);
4276 if (!added
&& pa
->pa_free
< tmp_pa
->pa_free
) {
4277 /* Add to the tail of the previous entry */
4278 list_add_tail_rcu(&pa
->pa_inode_list
,
4279 &tmp_pa
->pa_inode_list
);
4282 * we want to count the total
4283 * number of entries in the list
4286 spin_unlock(&tmp_pa
->pa_lock
);
4287 lg_prealloc_count
++;
4290 list_add_tail_rcu(&pa
->pa_inode_list
,
4291 &lg
->lg_prealloc_list
[order
]);
4292 spin_unlock(&lg
->lg_prealloc_lock
);
4294 /* Now trim the list to be not more than 8 elements */
4295 if (lg_prealloc_count
> 8) {
4296 ext4_mb_discard_lg_preallocations(sb
, lg
,
4297 order
, lg_prealloc_count
);
4304 * release all resource we used in allocation
4306 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
4308 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4309 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
4311 if (pa
->pa_type
== MB_GROUP_PA
) {
4312 /* see comment in ext4_mb_use_group_pa() */
4313 spin_lock(&pa
->pa_lock
);
4314 pa
->pa_pstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4315 pa
->pa_lstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4316 pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
4317 pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
4318 spin_unlock(&pa
->pa_lock
);
4323 * We want to add the pa to the right bucket.
4324 * Remove it from the list and while adding
4325 * make sure the list to which we are adding
4328 if ((pa
->pa_type
== MB_GROUP_PA
) && likely(pa
->pa_free
)) {
4329 spin_lock(pa
->pa_obj_lock
);
4330 list_del_rcu(&pa
->pa_inode_list
);
4331 spin_unlock(pa
->pa_obj_lock
);
4332 ext4_mb_add_n_trim(ac
);
4334 ext4_mb_put_pa(ac
, ac
->ac_sb
, pa
);
4336 if (ac
->ac_bitmap_page
)
4337 page_cache_release(ac
->ac_bitmap_page
);
4338 if (ac
->ac_buddy_page
)
4339 page_cache_release(ac
->ac_buddy_page
);
4340 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
4341 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
4342 ext4_mb_collect_stats(ac
);
4346 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
4348 ext4_group_t i
, ngroups
= ext4_get_groups_count(sb
);
4352 trace_ext4_mb_discard_preallocations(sb
, needed
);
4353 for (i
= 0; i
< ngroups
&& needed
> 0; i
++) {
4354 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4363 * Main entry point into mballoc to allocate blocks
4364 * it tries to use preallocation first, then falls back
4365 * to usual allocation
4367 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4368 struct ext4_allocation_request
*ar
, int *errp
)
4371 struct ext4_allocation_context
*ac
= NULL
;
4372 struct ext4_sb_info
*sbi
;
4373 struct super_block
*sb
;
4374 ext4_fsblk_t block
= 0;
4375 unsigned int inquota
= 0;
4376 unsigned int reserv_clstrs
= 0;
4379 sb
= ar
->inode
->i_sb
;
4382 trace_ext4_request_blocks(ar
);
4384 /* Allow to use superuser reservation for quota file */
4385 if (IS_NOQUOTA(ar
->inode
))
4386 ar
->flags
|= EXT4_MB_USE_ROOT_BLOCKS
;
4389 * For delayed allocation, we could skip the ENOSPC and
4390 * EDQUOT check, as blocks and quotas have been already
4391 * reserved when data being copied into pagecache.
4393 if (ext4_test_inode_state(ar
->inode
, EXT4_STATE_DELALLOC_RESERVED
))
4394 ar
->flags
|= EXT4_MB_DELALLOC_RESERVED
;
4396 /* Without delayed allocation we need to verify
4397 * there is enough free blocks to do block allocation
4398 * and verify allocation doesn't exceed the quota limits.
4401 ext4_claim_free_clusters(sbi
, ar
->len
, ar
->flags
)) {
4403 /* let others to free the space */
4405 ar
->len
= ar
->len
>> 1;
4411 reserv_clstrs
= ar
->len
;
4412 if (ar
->flags
& EXT4_MB_USE_ROOT_BLOCKS
) {
4413 dquot_alloc_block_nofail(ar
->inode
,
4414 EXT4_C2B(sbi
, ar
->len
));
4417 dquot_alloc_block(ar
->inode
,
4418 EXT4_C2B(sbi
, ar
->len
))) {
4420 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4431 ac
= kmem_cache_zalloc(ext4_ac_cachep
, GFP_NOFS
);
4438 *errp
= ext4_mb_initialize_context(ac
, ar
);
4444 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4445 if (!ext4_mb_use_preallocated(ac
)) {
4446 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4447 ext4_mb_normalize_request(ac
, ar
);
4449 /* allocate space in core */
4450 *errp
= ext4_mb_regular_allocator(ac
);
4452 goto discard_and_exit
;
4454 /* as we've just preallocated more space than
4455 * user requested originally, we store allocated
4456 * space in a special descriptor */
4457 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4458 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4459 *errp
= ext4_mb_new_preallocation(ac
);
4462 ext4_discard_allocated_blocks(ac
);
4466 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4467 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
, reserv_clstrs
);
4468 if (*errp
== -EAGAIN
) {
4470 * drop the reference that we took
4471 * in ext4_mb_use_best_found
4473 ext4_mb_release_context(ac
);
4474 ac
->ac_b_ex
.fe_group
= 0;
4475 ac
->ac_b_ex
.fe_start
= 0;
4476 ac
->ac_b_ex
.fe_len
= 0;
4477 ac
->ac_status
= AC_STATUS_CONTINUE
;
4480 ext4_discard_allocated_blocks(ac
);
4483 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4484 ar
->len
= ac
->ac_b_ex
.fe_len
;
4487 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4495 ac
->ac_b_ex
.fe_len
= 0;
4497 ext4_mb_show_ac(ac
);
4499 ext4_mb_release_context(ac
);
4502 kmem_cache_free(ext4_ac_cachep
, ac
);
4503 if (inquota
&& ar
->len
< inquota
)
4504 dquot_free_block(ar
->inode
, EXT4_C2B(sbi
, inquota
- ar
->len
));
4506 if (!ext4_test_inode_state(ar
->inode
,
4507 EXT4_STATE_DELALLOC_RESERVED
))
4508 /* release all the reserved blocks if non delalloc */
4509 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
4513 trace_ext4_allocate_blocks(ar
, (unsigned long long)block
);
4519 * We can merge two free data extents only if the physical blocks
4520 * are contiguous, AND the extents were freed by the same transaction,
4521 * AND the blocks are associated with the same group.
4523 static int can_merge(struct ext4_free_data
*entry1
,
4524 struct ext4_free_data
*entry2
)
4526 if ((entry1
->efd_tid
== entry2
->efd_tid
) &&
4527 (entry1
->efd_group
== entry2
->efd_group
) &&
4528 ((entry1
->efd_start_cluster
+ entry1
->efd_count
) == entry2
->efd_start_cluster
))
4533 static noinline_for_stack
int
4534 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4535 struct ext4_free_data
*new_entry
)
4537 ext4_group_t group
= e4b
->bd_group
;
4538 ext4_grpblk_t cluster
;
4539 struct ext4_free_data
*entry
;
4540 struct ext4_group_info
*db
= e4b
->bd_info
;
4541 struct super_block
*sb
= e4b
->bd_sb
;
4542 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4543 struct rb_node
**n
= &db
->bb_free_root
.rb_node
, *node
;
4544 struct rb_node
*parent
= NULL
, *new_node
;
4546 BUG_ON(!ext4_handle_valid(handle
));
4547 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4548 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4550 new_node
= &new_entry
->efd_node
;
4551 cluster
= new_entry
->efd_start_cluster
;
4554 /* first free block exent. We need to
4555 protect buddy cache from being freed,
4556 * otherwise we'll refresh it from
4557 * on-disk bitmap and lose not-yet-available
4559 page_cache_get(e4b
->bd_buddy_page
);
4560 page_cache_get(e4b
->bd_bitmap_page
);
4564 entry
= rb_entry(parent
, struct ext4_free_data
, efd_node
);
4565 if (cluster
< entry
->efd_start_cluster
)
4567 else if (cluster
>= (entry
->efd_start_cluster
+ entry
->efd_count
))
4568 n
= &(*n
)->rb_right
;
4570 ext4_grp_locked_error(sb
, group
, 0,
4571 ext4_group_first_block_no(sb
, group
) +
4572 EXT4_C2B(sbi
, cluster
),
4573 "Block already on to-be-freed list");
4578 rb_link_node(new_node
, parent
, n
);
4579 rb_insert_color(new_node
, &db
->bb_free_root
);
4581 /* Now try to see the extent can be merged to left and right */
4582 node
= rb_prev(new_node
);
4584 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4585 if (can_merge(entry
, new_entry
) &&
4586 ext4_journal_callback_try_del(handle
, &entry
->efd_jce
)) {
4587 new_entry
->efd_start_cluster
= entry
->efd_start_cluster
;
4588 new_entry
->efd_count
+= entry
->efd_count
;
4589 rb_erase(node
, &(db
->bb_free_root
));
4590 kmem_cache_free(ext4_free_data_cachep
, entry
);
4594 node
= rb_next(new_node
);
4596 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4597 if (can_merge(new_entry
, entry
) &&
4598 ext4_journal_callback_try_del(handle
, &entry
->efd_jce
)) {
4599 new_entry
->efd_count
+= entry
->efd_count
;
4600 rb_erase(node
, &(db
->bb_free_root
));
4601 kmem_cache_free(ext4_free_data_cachep
, entry
);
4604 /* Add the extent to transaction's private list */
4605 ext4_journal_callback_add(handle
, ext4_free_data_callback
,
4606 &new_entry
->efd_jce
);
4611 * ext4_free_blocks() -- Free given blocks and update quota
4612 * @handle: handle for this transaction
4614 * @block: start physical block to free
4615 * @count: number of blocks to count
4616 * @flags: flags used by ext4_free_blocks
4618 void ext4_free_blocks(handle_t
*handle
, struct inode
*inode
,
4619 struct buffer_head
*bh
, ext4_fsblk_t block
,
4620 unsigned long count
, int flags
)
4622 struct buffer_head
*bitmap_bh
= NULL
;
4623 struct super_block
*sb
= inode
->i_sb
;
4624 struct ext4_group_desc
*gdp
;
4625 unsigned int overflow
;
4627 struct buffer_head
*gd_bh
;
4628 ext4_group_t block_group
;
4629 struct ext4_sb_info
*sbi
;
4630 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4631 struct ext4_buddy e4b
;
4632 unsigned int count_clusters
;
4639 BUG_ON(block
!= bh
->b_blocknr
);
4641 block
= bh
->b_blocknr
;
4645 if (!(flags
& EXT4_FREE_BLOCKS_VALIDATED
) &&
4646 !ext4_data_block_valid(sbi
, block
, count
)) {
4647 ext4_error(sb
, "Freeing blocks not in datazone - "
4648 "block = %llu, count = %lu", block
, count
);
4652 ext4_debug("freeing block %llu\n", block
);
4653 trace_ext4_free_blocks(inode
, block
, count
, flags
);
4655 if (flags
& EXT4_FREE_BLOCKS_FORGET
) {
4656 struct buffer_head
*tbh
= bh
;
4659 BUG_ON(bh
&& (count
> 1));
4661 for (i
= 0; i
< count
; i
++) {
4664 tbh
= sb_find_get_block(inode
->i_sb
,
4668 ext4_forget(handle
, flags
& EXT4_FREE_BLOCKS_METADATA
,
4669 inode
, tbh
, block
+ i
);
4674 * We need to make sure we don't reuse the freed block until
4675 * after the transaction is committed, which we can do by
4676 * treating the block as metadata, below. We make an
4677 * exception if the inode is to be written in writeback mode
4678 * since writeback mode has weak data consistency guarantees.
4680 if (!ext4_should_writeback_data(inode
))
4681 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4684 * If the extent to be freed does not begin on a cluster
4685 * boundary, we need to deal with partial clusters at the
4686 * beginning and end of the extent. Normally we will free
4687 * blocks at the beginning or the end unless we are explicitly
4688 * requested to avoid doing so.
4690 overflow
= EXT4_PBLK_COFF(sbi
, block
);
4692 if (flags
& EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER
) {
4693 overflow
= sbi
->s_cluster_ratio
- overflow
;
4695 if (count
> overflow
)
4704 overflow
= EXT4_LBLK_COFF(sbi
, count
);
4706 if (flags
& EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER
) {
4707 if (count
> overflow
)
4712 count
+= sbi
->s_cluster_ratio
- overflow
;
4717 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4719 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
4720 ext4_get_group_info(sb
, block_group
))))
4724 * Check to see if we are freeing blocks across a group
4727 if (EXT4_C2B(sbi
, bit
) + count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4728 overflow
= EXT4_C2B(sbi
, bit
) + count
-
4729 EXT4_BLOCKS_PER_GROUP(sb
);
4732 count_clusters
= EXT4_NUM_B2C(sbi
, count
);
4733 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4738 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4744 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4745 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4746 in_range(block
, ext4_inode_table(sb
, gdp
),
4747 EXT4_SB(sb
)->s_itb_per_group
) ||
4748 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4749 EXT4_SB(sb
)->s_itb_per_group
)) {
4751 ext4_error(sb
, "Freeing blocks in system zone - "
4752 "Block = %llu, count = %lu", block
, count
);
4753 /* err = 0. ext4_std_error should be a no op */
4757 BUFFER_TRACE(bitmap_bh
, "getting write access");
4758 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4763 * We are about to modify some metadata. Call the journal APIs
4764 * to unshare ->b_data if a currently-committing transaction is
4767 BUFFER_TRACE(gd_bh
, "get_write_access");
4768 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4771 #ifdef AGGRESSIVE_CHECK
4774 for (i
= 0; i
< count_clusters
; i
++)
4775 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4778 trace_ext4_mballoc_free(sb
, inode
, block_group
, bit
, count_clusters
);
4780 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4784 if ((flags
& EXT4_FREE_BLOCKS_METADATA
) && ext4_handle_valid(handle
)) {
4785 struct ext4_free_data
*new_entry
;
4787 * blocks being freed are metadata. these blocks shouldn't
4788 * be used until this transaction is committed
4791 new_entry
= kmem_cache_alloc(ext4_free_data_cachep
, GFP_NOFS
);
4794 * We use a retry loop because
4795 * ext4_free_blocks() is not allowed to fail.
4798 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
4801 new_entry
->efd_start_cluster
= bit
;
4802 new_entry
->efd_group
= block_group
;
4803 new_entry
->efd_count
= count_clusters
;
4804 new_entry
->efd_tid
= handle
->h_transaction
->t_tid
;
4806 ext4_lock_group(sb
, block_group
);
4807 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4808 ext4_mb_free_metadata(handle
, &e4b
, new_entry
);
4810 /* need to update group_info->bb_free and bitmap
4811 * with group lock held. generate_buddy look at
4812 * them with group lock_held
4814 if (test_opt(sb
, DISCARD
)) {
4815 err
= ext4_issue_discard(sb
, block_group
, bit
, count
);
4816 if (err
&& err
!= -EOPNOTSUPP
)
4817 ext4_msg(sb
, KERN_WARNING
, "discard request in"
4818 " group:%d block:%d count:%lu failed"
4819 " with %d", block_group
, bit
, count
,
4822 EXT4_MB_GRP_CLEAR_TRIMMED(e4b
.bd_info
);
4824 ext4_lock_group(sb
, block_group
);
4825 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4826 mb_free_blocks(inode
, &e4b
, bit
, count_clusters
);
4829 ret
= ext4_free_group_clusters(sb
, gdp
) + count_clusters
;
4830 ext4_free_group_clusters_set(sb
, gdp
, ret
);
4831 ext4_block_bitmap_csum_set(sb
, block_group
, gdp
, bitmap_bh
);
4832 ext4_group_desc_csum_set(sb
, block_group
, gdp
);
4833 ext4_unlock_group(sb
, block_group
);
4835 if (sbi
->s_log_groups_per_flex
) {
4836 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4837 atomic64_add(count_clusters
,
4838 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4841 if (flags
& EXT4_FREE_BLOCKS_RESERVE
&& ei
->i_reserved_data_blocks
) {
4842 percpu_counter_add(&sbi
->s_dirtyclusters_counter
,
4844 spin_lock(&ei
->i_block_reservation_lock
);
4845 if (flags
& EXT4_FREE_BLOCKS_METADATA
)
4846 ei
->i_reserved_meta_blocks
+= count_clusters
;
4848 ei
->i_reserved_data_blocks
+= count_clusters
;
4849 spin_unlock(&ei
->i_block_reservation_lock
);
4850 if (!(flags
& EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
))
4851 dquot_reclaim_block(inode
,
4852 EXT4_C2B(sbi
, count_clusters
));
4853 } else if (!(flags
& EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
))
4854 dquot_free_block(inode
, EXT4_C2B(sbi
, count_clusters
));
4855 percpu_counter_add(&sbi
->s_freeclusters_counter
, count_clusters
);
4857 ext4_mb_unload_buddy(&e4b
);
4859 /* We dirtied the bitmap block */
4860 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4861 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4863 /* And the group descriptor block */
4864 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4865 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4869 if (overflow
&& !err
) {
4877 ext4_std_error(sb
, err
);
4882 * ext4_group_add_blocks() -- Add given blocks to an existing group
4883 * @handle: handle to this transaction
4885 * @block: start physical block to add to the block group
4886 * @count: number of blocks to free
4888 * This marks the blocks as free in the bitmap and buddy.
4890 int ext4_group_add_blocks(handle_t
*handle
, struct super_block
*sb
,
4891 ext4_fsblk_t block
, unsigned long count
)
4893 struct buffer_head
*bitmap_bh
= NULL
;
4894 struct buffer_head
*gd_bh
;
4895 ext4_group_t block_group
;
4898 struct ext4_group_desc
*desc
;
4899 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4900 struct ext4_buddy e4b
;
4901 int err
= 0, ret
, blk_free_count
;
4902 ext4_grpblk_t blocks_freed
;
4904 ext4_debug("Adding block(s) %llu-%llu\n", block
, block
+ count
- 1);
4909 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4911 * Check to see if we are freeing blocks across a group
4914 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4915 ext4_warning(sb
, "too much blocks added to group %u\n",
4921 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4927 desc
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4933 if (in_range(ext4_block_bitmap(sb
, desc
), block
, count
) ||
4934 in_range(ext4_inode_bitmap(sb
, desc
), block
, count
) ||
4935 in_range(block
, ext4_inode_table(sb
, desc
), sbi
->s_itb_per_group
) ||
4936 in_range(block
+ count
- 1, ext4_inode_table(sb
, desc
),
4937 sbi
->s_itb_per_group
)) {
4938 ext4_error(sb
, "Adding blocks in system zones - "
4939 "Block = %llu, count = %lu",
4945 BUFFER_TRACE(bitmap_bh
, "getting write access");
4946 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4951 * We are about to modify some metadata. Call the journal APIs
4952 * to unshare ->b_data if a currently-committing transaction is
4955 BUFFER_TRACE(gd_bh
, "get_write_access");
4956 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4960 for (i
= 0, blocks_freed
= 0; i
< count
; i
++) {
4961 BUFFER_TRACE(bitmap_bh
, "clear bit");
4962 if (!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
)) {
4963 ext4_error(sb
, "bit already cleared for block %llu",
4964 (ext4_fsblk_t
)(block
+ i
));
4965 BUFFER_TRACE(bitmap_bh
, "bit already cleared");
4971 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4976 * need to update group_info->bb_free and bitmap
4977 * with group lock held. generate_buddy look at
4978 * them with group lock_held
4980 ext4_lock_group(sb
, block_group
);
4981 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4982 mb_free_blocks(NULL
, &e4b
, bit
, count
);
4983 blk_free_count
= blocks_freed
+ ext4_free_group_clusters(sb
, desc
);
4984 ext4_free_group_clusters_set(sb
, desc
, blk_free_count
);
4985 ext4_block_bitmap_csum_set(sb
, block_group
, desc
, bitmap_bh
);
4986 ext4_group_desc_csum_set(sb
, block_group
, desc
);
4987 ext4_unlock_group(sb
, block_group
);
4988 percpu_counter_add(&sbi
->s_freeclusters_counter
,
4989 EXT4_NUM_B2C(sbi
, blocks_freed
));
4991 if (sbi
->s_log_groups_per_flex
) {
4992 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4993 atomic64_add(EXT4_NUM_B2C(sbi
, blocks_freed
),
4994 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4997 ext4_mb_unload_buddy(&e4b
);
4999 /* We dirtied the bitmap block */
5000 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
5001 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
5003 /* And the group descriptor block */
5004 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
5005 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
5011 ext4_std_error(sb
, err
);
5016 * ext4_trim_extent -- function to TRIM one single free extent in the group
5017 * @sb: super block for the file system
5018 * @start: starting block of the free extent in the alloc. group
5019 * @count: number of blocks to TRIM
5020 * @group: alloc. group we are working with
5021 * @e4b: ext4 buddy for the group
5023 * Trim "count" blocks starting at "start" in the "group". To assure that no
5024 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5025 * be called with under the group lock.
5027 static int ext4_trim_extent(struct super_block
*sb
, int start
, int count
,
5028 ext4_group_t group
, struct ext4_buddy
*e4b
)
5032 struct ext4_free_extent ex
;
5035 trace_ext4_trim_extent(sb
, group
, start
, count
);
5037 assert_spin_locked(ext4_group_lock_ptr(sb
, group
));
5039 ex
.fe_start
= start
;
5040 ex
.fe_group
= group
;
5044 * Mark blocks used, so no one can reuse them while
5047 mb_mark_used(e4b
, &ex
);
5048 ext4_unlock_group(sb
, group
);
5049 ret
= ext4_issue_discard(sb
, group
, start
, count
);
5050 ext4_lock_group(sb
, group
);
5051 mb_free_blocks(NULL
, e4b
, start
, ex
.fe_len
);
5056 * ext4_trim_all_free -- function to trim all free space in alloc. group
5057 * @sb: super block for file system
5058 * @group: group to be trimmed
5059 * @start: first group block to examine
5060 * @max: last group block to examine
5061 * @minblocks: minimum extent block count
5063 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5064 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5068 * ext4_trim_all_free walks through group's block bitmap searching for free
5069 * extents. When the free extent is found, mark it as used in group buddy
5070 * bitmap. Then issue a TRIM command on this extent and free the extent in
5071 * the group buddy bitmap. This is done until whole group is scanned.
5073 static ext4_grpblk_t
5074 ext4_trim_all_free(struct super_block
*sb
, ext4_group_t group
,
5075 ext4_grpblk_t start
, ext4_grpblk_t max
,
5076 ext4_grpblk_t minblocks
)
5079 ext4_grpblk_t next
, count
= 0, free_count
= 0;
5080 struct ext4_buddy e4b
;
5083 trace_ext4_trim_all_free(sb
, group
, start
, max
);
5085 ret
= ext4_mb_load_buddy(sb
, group
, &e4b
);
5087 ext4_error(sb
, "Error in loading buddy "
5088 "information for %u", group
);
5091 bitmap
= e4b
.bd_bitmap
;
5093 ext4_lock_group(sb
, group
);
5094 if (EXT4_MB_GRP_WAS_TRIMMED(e4b
.bd_info
) &&
5095 minblocks
>= atomic_read(&EXT4_SB(sb
)->s_last_trim_minblks
))
5098 start
= (e4b
.bd_info
->bb_first_free
> start
) ?
5099 e4b
.bd_info
->bb_first_free
: start
;
5101 while (start
<= max
) {
5102 start
= mb_find_next_zero_bit(bitmap
, max
+ 1, start
);
5105 next
= mb_find_next_bit(bitmap
, max
+ 1, start
);
5107 if ((next
- start
) >= minblocks
) {
5108 ret
= ext4_trim_extent(sb
, start
,
5109 next
- start
, group
, &e4b
);
5110 if (ret
&& ret
!= -EOPNOTSUPP
)
5113 count
+= next
- start
;
5115 free_count
+= next
- start
;
5118 if (fatal_signal_pending(current
)) {
5119 count
= -ERESTARTSYS
;
5123 if (need_resched()) {
5124 ext4_unlock_group(sb
, group
);
5126 ext4_lock_group(sb
, group
);
5129 if ((e4b
.bd_info
->bb_free
- free_count
) < minblocks
)
5135 EXT4_MB_GRP_SET_TRIMMED(e4b
.bd_info
);
5138 ext4_unlock_group(sb
, group
);
5139 ext4_mb_unload_buddy(&e4b
);
5141 ext4_debug("trimmed %d blocks in the group %d\n",
5148 * ext4_trim_fs() -- trim ioctl handle function
5149 * @sb: superblock for filesystem
5150 * @range: fstrim_range structure
5152 * start: First Byte to trim
5153 * len: number of Bytes to trim from start
5154 * minlen: minimum extent length in Bytes
5155 * ext4_trim_fs goes through all allocation groups containing Bytes from
5156 * start to start+len. For each such a group ext4_trim_all_free function
5157 * is invoked to trim all free space.
5159 int ext4_trim_fs(struct super_block
*sb
, struct fstrim_range
*range
)
5161 struct ext4_group_info
*grp
;
5162 ext4_group_t group
, first_group
, last_group
;
5163 ext4_grpblk_t cnt
= 0, first_cluster
, last_cluster
;
5164 uint64_t start
, end
, minlen
, trimmed
= 0;
5165 ext4_fsblk_t first_data_blk
=
5166 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
5167 ext4_fsblk_t max_blks
= ext4_blocks_count(EXT4_SB(sb
)->s_es
);
5170 start
= range
->start
>> sb
->s_blocksize_bits
;
5171 end
= start
+ (range
->len
>> sb
->s_blocksize_bits
) - 1;
5172 minlen
= EXT4_NUM_B2C(EXT4_SB(sb
),
5173 range
->minlen
>> sb
->s_blocksize_bits
);
5175 if (minlen
> EXT4_CLUSTERS_PER_GROUP(sb
) ||
5176 start
>= max_blks
||
5177 range
->len
< sb
->s_blocksize
)
5179 if (end
>= max_blks
)
5181 if (end
<= first_data_blk
)
5183 if (start
< first_data_blk
)
5184 start
= first_data_blk
;
5186 /* Determine first and last group to examine based on start and end */
5187 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) start
,
5188 &first_group
, &first_cluster
);
5189 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) end
,
5190 &last_group
, &last_cluster
);
5192 /* end now represents the last cluster to discard in this group */
5193 end
= EXT4_CLUSTERS_PER_GROUP(sb
) - 1;
5195 for (group
= first_group
; group
<= last_group
; group
++) {
5196 grp
= ext4_get_group_info(sb
, group
);
5197 /* We only do this if the grp has never been initialized */
5198 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
5199 ret
= ext4_mb_init_group(sb
, group
);
5205 * For all the groups except the last one, last cluster will
5206 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5207 * change it for the last group, note that last_cluster is
5208 * already computed earlier by ext4_get_group_no_and_offset()
5210 if (group
== last_group
)
5213 if (grp
->bb_free
>= minlen
) {
5214 cnt
= ext4_trim_all_free(sb
, group
, first_cluster
,
5224 * For every group except the first one, we are sure
5225 * that the first cluster to discard will be cluster #0.
5231 atomic_set(&EXT4_SB(sb
)->s_last_trim_minblks
, minlen
);
5234 range
->len
= EXT4_C2B(EXT4_SB(sb
), trimmed
) << sb
->s_blocksize_bits
;