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 ext4_grpblk_t max
= EXT4_CLUSTERS_PER_GROUP(sb
);
730 unsigned fragments
= 0;
731 unsigned long long period
= get_cycles();
733 /* initialize buddy from bitmap which is aggregation
734 * of on-disk bitmap and preallocations */
735 i
= mb_find_next_zero_bit(bitmap
, max
, 0);
736 grp
->bb_first_free
= i
;
740 i
= mb_find_next_bit(bitmap
, max
, i
);
744 ext4_mb_mark_free_simple(sb
, buddy
, first
, len
, grp
);
746 grp
->bb_counters
[0]++;
748 i
= mb_find_next_zero_bit(bitmap
, max
, i
);
750 grp
->bb_fragments
= fragments
;
752 if (free
!= grp
->bb_free
) {
753 ext4_grp_locked_error(sb
, group
, 0, 0,
754 "%u clusters in bitmap, %u in gd; "
755 "block bitmap corrupt.",
758 * If we intend to continue, we consider group descriptor
759 * corrupt and update bb_free using bitmap value
762 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT
, &grp
->bb_state
);
764 mb_set_largest_free_order(sb
, grp
);
766 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
, &(grp
->bb_state
));
768 period
= get_cycles() - period
;
769 spin_lock(&EXT4_SB(sb
)->s_bal_lock
);
770 EXT4_SB(sb
)->s_mb_buddies_generated
++;
771 EXT4_SB(sb
)->s_mb_generation_time
+= period
;
772 spin_unlock(&EXT4_SB(sb
)->s_bal_lock
);
775 static void mb_regenerate_buddy(struct ext4_buddy
*e4b
)
781 while ((buddy
= mb_find_buddy(e4b
, order
++, &count
))) {
782 ext4_set_bits(buddy
, 0, count
);
784 e4b
->bd_info
->bb_fragments
= 0;
785 memset(e4b
->bd_info
->bb_counters
, 0,
786 sizeof(*e4b
->bd_info
->bb_counters
) *
787 (e4b
->bd_sb
->s_blocksize_bits
+ 2));
789 ext4_mb_generate_buddy(e4b
->bd_sb
, e4b
->bd_buddy
,
790 e4b
->bd_bitmap
, e4b
->bd_group
);
793 /* The buddy information is attached the buddy cache inode
794 * for convenience. The information regarding each group
795 * is loaded via ext4_mb_load_buddy. The information involve
796 * block bitmap and buddy information. The information are
797 * stored in the inode as
800 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
803 * one block each for bitmap and buddy information.
804 * So for each group we take up 2 blocks. A page can
805 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
806 * So it can have information regarding groups_per_page which
807 * is blocks_per_page/2
809 * Locking note: This routine takes the block group lock of all groups
810 * for this page; do not hold this lock when calling this routine!
813 static int ext4_mb_init_cache(struct page
*page
, char *incore
)
815 ext4_group_t ngroups
;
821 ext4_group_t first_group
, group
;
823 struct super_block
*sb
;
824 struct buffer_head
*bhs
;
825 struct buffer_head
**bh
= NULL
;
829 struct ext4_group_info
*grinfo
;
831 mb_debug(1, "init page %lu\n", page
->index
);
833 inode
= page
->mapping
->host
;
835 ngroups
= ext4_get_groups_count(sb
);
836 blocksize
= 1 << inode
->i_blkbits
;
837 blocks_per_page
= PAGE_CACHE_SIZE
/ blocksize
;
839 groups_per_page
= blocks_per_page
>> 1;
840 if (groups_per_page
== 0)
843 /* allocate buffer_heads to read bitmaps */
844 if (groups_per_page
> 1) {
845 i
= sizeof(struct buffer_head
*) * groups_per_page
;
846 bh
= kzalloc(i
, GFP_NOFS
);
854 first_group
= page
->index
* blocks_per_page
/ 2;
856 /* read all groups the page covers into the cache */
857 for (i
= 0, group
= first_group
; i
< groups_per_page
; i
++, group
++) {
858 if (group
>= ngroups
)
861 grinfo
= ext4_get_group_info(sb
, group
);
863 * If page is uptodate then we came here after online resize
864 * which added some new uninitialized group info structs, so
865 * we must skip all initialized uptodate buddies on the page,
866 * which may be currently in use by an allocating task.
868 if (PageUptodate(page
) && !EXT4_MB_GRP_NEED_INIT(grinfo
)) {
872 if (!(bh
[i
] = ext4_read_block_bitmap_nowait(sb
, group
))) {
876 mb_debug(1, "read bitmap for group %u\n", group
);
879 /* wait for I/O completion */
880 for (i
= 0, group
= first_group
; i
< groups_per_page
; i
++, group
++) {
881 if (bh
[i
] && ext4_wait_block_bitmap(sb
, group
, bh
[i
])) {
887 first_block
= page
->index
* blocks_per_page
;
888 for (i
= 0; i
< blocks_per_page
; i
++) {
889 group
= (first_block
+ i
) >> 1;
890 if (group
>= ngroups
)
893 if (!bh
[group
- first_group
])
894 /* skip initialized uptodate buddy */
898 * data carry information regarding this
899 * particular group in the format specified
903 data
= page_address(page
) + (i
* blocksize
);
904 bitmap
= bh
[group
- first_group
]->b_data
;
907 * We place the buddy block and bitmap block
910 if ((first_block
+ i
) & 1) {
911 /* this is block of buddy */
912 BUG_ON(incore
== NULL
);
913 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
914 group
, page
->index
, i
* blocksize
);
915 trace_ext4_mb_buddy_bitmap_load(sb
, group
);
916 grinfo
= ext4_get_group_info(sb
, group
);
917 grinfo
->bb_fragments
= 0;
918 memset(grinfo
->bb_counters
, 0,
919 sizeof(*grinfo
->bb_counters
) *
920 (sb
->s_blocksize_bits
+2));
922 * incore got set to the group block bitmap below
924 ext4_lock_group(sb
, group
);
926 memset(data
, 0xff, blocksize
);
927 ext4_mb_generate_buddy(sb
, data
, incore
, group
);
928 ext4_unlock_group(sb
, group
);
931 /* this is block of bitmap */
932 BUG_ON(incore
!= NULL
);
933 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
934 group
, page
->index
, i
* blocksize
);
935 trace_ext4_mb_bitmap_load(sb
, group
);
937 /* see comments in ext4_mb_put_pa() */
938 ext4_lock_group(sb
, group
);
939 memcpy(data
, bitmap
, blocksize
);
941 /* mark all preallocated blks used in in-core bitmap */
942 ext4_mb_generate_from_pa(sb
, data
, group
);
943 ext4_mb_generate_from_freelist(sb
, data
, group
);
944 ext4_unlock_group(sb
, group
);
946 /* set incore so that the buddy information can be
947 * generated using this
952 SetPageUptodate(page
);
956 for (i
= 0; i
< groups_per_page
; i
++)
965 * Lock the buddy and bitmap pages. This make sure other parallel init_group
966 * on the same buddy page doesn't happen whild holding the buddy page lock.
967 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
968 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
970 static int ext4_mb_get_buddy_page_lock(struct super_block
*sb
,
971 ext4_group_t group
, struct ext4_buddy
*e4b
)
973 struct inode
*inode
= EXT4_SB(sb
)->s_buddy_cache
;
974 int block
, pnum
, poff
;
978 e4b
->bd_buddy_page
= NULL
;
979 e4b
->bd_bitmap_page
= NULL
;
981 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
983 * the buddy cache inode stores the block bitmap
984 * and buddy information in consecutive blocks.
985 * So for each group we need two blocks.
988 pnum
= block
/ blocks_per_page
;
989 poff
= block
% blocks_per_page
;
990 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
993 BUG_ON(page
->mapping
!= inode
->i_mapping
);
994 e4b
->bd_bitmap_page
= page
;
995 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
997 if (blocks_per_page
>= 2) {
998 /* buddy and bitmap are on the same page */
1003 pnum
= block
/ blocks_per_page
;
1004 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1007 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1008 e4b
->bd_buddy_page
= page
;
1012 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy
*e4b
)
1014 if (e4b
->bd_bitmap_page
) {
1015 unlock_page(e4b
->bd_bitmap_page
);
1016 page_cache_release(e4b
->bd_bitmap_page
);
1018 if (e4b
->bd_buddy_page
) {
1019 unlock_page(e4b
->bd_buddy_page
);
1020 page_cache_release(e4b
->bd_buddy_page
);
1025 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1026 * block group lock of all groups for this page; do not hold the BG lock when
1027 * calling this routine!
1029 static noinline_for_stack
1030 int ext4_mb_init_group(struct super_block
*sb
, ext4_group_t group
)
1033 struct ext4_group_info
*this_grp
;
1034 struct ext4_buddy e4b
;
1039 mb_debug(1, "init group %u\n", group
);
1040 this_grp
= ext4_get_group_info(sb
, group
);
1042 * This ensures that we don't reinit the buddy cache
1043 * page which map to the group from which we are already
1044 * allocating. If we are looking at the buddy cache we would
1045 * have taken a reference using ext4_mb_load_buddy and that
1046 * would have pinned buddy page to page cache.
1048 ret
= ext4_mb_get_buddy_page_lock(sb
, group
, &e4b
);
1049 if (ret
|| !EXT4_MB_GRP_NEED_INIT(this_grp
)) {
1051 * somebody initialized the group
1052 * return without doing anything
1057 page
= e4b
.bd_bitmap_page
;
1058 ret
= ext4_mb_init_cache(page
, NULL
);
1061 if (!PageUptodate(page
)) {
1065 mark_page_accessed(page
);
1067 if (e4b
.bd_buddy_page
== NULL
) {
1069 * If both the bitmap and buddy are in
1070 * the same page we don't need to force
1076 /* init buddy cache */
1077 page
= e4b
.bd_buddy_page
;
1078 ret
= ext4_mb_init_cache(page
, e4b
.bd_bitmap
);
1081 if (!PageUptodate(page
)) {
1085 mark_page_accessed(page
);
1087 ext4_mb_put_buddy_page_lock(&e4b
);
1092 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1093 * block group lock of all groups for this page; do not hold the BG lock when
1094 * calling this routine!
1096 static noinline_for_stack
int
1097 ext4_mb_load_buddy(struct super_block
*sb
, ext4_group_t group
,
1098 struct ext4_buddy
*e4b
)
1100 int blocks_per_page
;
1106 struct ext4_group_info
*grp
;
1107 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1108 struct inode
*inode
= sbi
->s_buddy_cache
;
1111 mb_debug(1, "load group %u\n", group
);
1113 blocks_per_page
= PAGE_CACHE_SIZE
/ sb
->s_blocksize
;
1114 grp
= ext4_get_group_info(sb
, group
);
1116 e4b
->bd_blkbits
= sb
->s_blocksize_bits
;
1119 e4b
->bd_group
= group
;
1120 e4b
->bd_buddy_page
= NULL
;
1121 e4b
->bd_bitmap_page
= NULL
;
1123 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
1125 * we need full data about the group
1126 * to make a good selection
1128 ret
= ext4_mb_init_group(sb
, group
);
1134 * the buddy cache inode stores the block bitmap
1135 * and buddy information in consecutive blocks.
1136 * So for each group we need two blocks.
1139 pnum
= block
/ blocks_per_page
;
1140 poff
= block
% blocks_per_page
;
1142 /* we could use find_or_create_page(), but it locks page
1143 * what we'd like to avoid in fast path ... */
1144 page
= find_get_page(inode
->i_mapping
, pnum
);
1145 if (page
== NULL
|| !PageUptodate(page
)) {
1148 * drop the page reference and try
1149 * to get the page with lock. If we
1150 * are not uptodate that implies
1151 * somebody just created the page but
1152 * is yet to initialize the same. So
1153 * wait for it to initialize.
1155 page_cache_release(page
);
1156 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1158 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1159 if (!PageUptodate(page
)) {
1160 ret
= ext4_mb_init_cache(page
, NULL
);
1165 mb_cmp_bitmaps(e4b
, page_address(page
) +
1166 (poff
* sb
->s_blocksize
));
1171 if (page
== NULL
|| !PageUptodate(page
)) {
1175 e4b
->bd_bitmap_page
= page
;
1176 e4b
->bd_bitmap
= page_address(page
) + (poff
* sb
->s_blocksize
);
1177 mark_page_accessed(page
);
1180 pnum
= block
/ blocks_per_page
;
1181 poff
= block
% blocks_per_page
;
1183 page
= find_get_page(inode
->i_mapping
, pnum
);
1184 if (page
== NULL
|| !PageUptodate(page
)) {
1186 page_cache_release(page
);
1187 page
= find_or_create_page(inode
->i_mapping
, pnum
, GFP_NOFS
);
1189 BUG_ON(page
->mapping
!= inode
->i_mapping
);
1190 if (!PageUptodate(page
)) {
1191 ret
= ext4_mb_init_cache(page
, e4b
->bd_bitmap
);
1200 if (page
== NULL
|| !PageUptodate(page
)) {
1204 e4b
->bd_buddy_page
= page
;
1205 e4b
->bd_buddy
= page_address(page
) + (poff
* sb
->s_blocksize
);
1206 mark_page_accessed(page
);
1208 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
1209 BUG_ON(e4b
->bd_buddy_page
== NULL
);
1215 page_cache_release(page
);
1216 if (e4b
->bd_bitmap_page
)
1217 page_cache_release(e4b
->bd_bitmap_page
);
1218 if (e4b
->bd_buddy_page
)
1219 page_cache_release(e4b
->bd_buddy_page
);
1220 e4b
->bd_buddy
= NULL
;
1221 e4b
->bd_bitmap
= NULL
;
1225 static void ext4_mb_unload_buddy(struct ext4_buddy
*e4b
)
1227 if (e4b
->bd_bitmap_page
)
1228 page_cache_release(e4b
->bd_bitmap_page
);
1229 if (e4b
->bd_buddy_page
)
1230 page_cache_release(e4b
->bd_buddy_page
);
1234 static int mb_find_order_for_block(struct ext4_buddy
*e4b
, int block
)
1239 BUG_ON(e4b
->bd_bitmap
== e4b
->bd_buddy
);
1240 BUG_ON(block
>= (1 << (e4b
->bd_blkbits
+ 3)));
1243 while (order
<= e4b
->bd_blkbits
+ 1) {
1245 if (!mb_test_bit(block
, bb
)) {
1246 /* this block is part of buddy of order 'order' */
1249 bb
+= 1 << (e4b
->bd_blkbits
- order
);
1255 static void mb_clear_bits(void *bm
, int cur
, int len
)
1261 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1262 /* fast path: clear whole word at once */
1263 addr
= bm
+ (cur
>> 3);
1268 mb_clear_bit(cur
, bm
);
1273 /* clear bits in given range
1274 * will return first found zero bit if any, -1 otherwise
1276 static int mb_test_and_clear_bits(void *bm
, int cur
, int len
)
1283 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1284 /* fast path: clear whole word at once */
1285 addr
= bm
+ (cur
>> 3);
1286 if (*addr
!= (__u32
)(-1) && zero_bit
== -1)
1287 zero_bit
= cur
+ mb_find_next_zero_bit(addr
, 32, 0);
1292 if (!mb_test_and_clear_bit(cur
, bm
) && zero_bit
== -1)
1300 void ext4_set_bits(void *bm
, int cur
, int len
)
1306 if ((cur
& 31) == 0 && (len
- cur
) >= 32) {
1307 /* fast path: set whole word at once */
1308 addr
= bm
+ (cur
>> 3);
1313 mb_set_bit(cur
, bm
);
1319 * _________________________________________________________________ */
1321 static inline int mb_buddy_adjust_border(int* bit
, void* bitmap
, int side
)
1323 if (mb_test_bit(*bit
+ side
, bitmap
)) {
1324 mb_clear_bit(*bit
, bitmap
);
1330 mb_set_bit(*bit
, bitmap
);
1335 static void mb_buddy_mark_free(struct ext4_buddy
*e4b
, int first
, int last
)
1339 void *buddy
= mb_find_buddy(e4b
, order
, &max
);
1344 /* Bits in range [first; last] are known to be set since
1345 * corresponding blocks were allocated. Bits in range
1346 * (first; last) will stay set because they form buddies on
1347 * upper layer. We just deal with borders if they don't
1348 * align with upper layer and then go up.
1349 * Releasing entire group is all about clearing
1350 * single bit of highest order buddy.
1354 * ---------------------------------
1356 * ---------------------------------
1357 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1358 * ---------------------------------
1360 * \_____________________/
1362 * Neither [1] nor [6] is aligned to above layer.
1363 * Left neighbour [0] is free, so mark it busy,
1364 * decrease bb_counters and extend range to
1366 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1367 * mark [6] free, increase bb_counters and shrink range to
1369 * Then shift range to [0; 2], go up and do the same.
1374 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&first
, buddy
, -1);
1376 e4b
->bd_info
->bb_counters
[order
] += mb_buddy_adjust_border(&last
, buddy
, 1);
1381 if (first
== last
|| !(buddy2
= mb_find_buddy(e4b
, order
, &max
))) {
1382 mb_clear_bits(buddy
, first
, last
- first
+ 1);
1383 e4b
->bd_info
->bb_counters
[order
- 1] += last
- first
+ 1;
1392 static void mb_free_blocks(struct inode
*inode
, struct ext4_buddy
*e4b
,
1393 int first
, int count
)
1395 int left_is_free
= 0;
1396 int right_is_free
= 0;
1398 int last
= first
+ count
- 1;
1399 struct super_block
*sb
= e4b
->bd_sb
;
1401 BUG_ON(last
>= (sb
->s_blocksize
<< 3));
1402 assert_spin_locked(ext4_group_lock_ptr(sb
, e4b
->bd_group
));
1403 /* Don't bother if the block group is corrupt. */
1404 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
)))
1407 mb_check_buddy(e4b
);
1408 mb_free_blocks_double(inode
, e4b
, first
, count
);
1410 e4b
->bd_info
->bb_free
+= count
;
1411 if (first
< e4b
->bd_info
->bb_first_free
)
1412 e4b
->bd_info
->bb_first_free
= first
;
1414 /* access memory sequentially: check left neighbour,
1415 * clear range and then check right neighbour
1418 left_is_free
= !mb_test_bit(first
- 1, e4b
->bd_bitmap
);
1419 block
= mb_test_and_clear_bits(e4b
->bd_bitmap
, first
, count
);
1420 if (last
+ 1 < EXT4_SB(sb
)->s_mb_maxs
[0])
1421 right_is_free
= !mb_test_bit(last
+ 1, e4b
->bd_bitmap
);
1423 if (unlikely(block
!= -1)) {
1424 ext4_fsblk_t blocknr
;
1426 blocknr
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1427 blocknr
+= EXT4_C2B(EXT4_SB(sb
), block
);
1428 ext4_grp_locked_error(sb
, e4b
->bd_group
,
1429 inode
? inode
->i_ino
: 0,
1431 "freeing already freed block "
1432 "(bit %u); block bitmap corrupt.",
1434 /* Mark the block group as corrupt. */
1435 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT
,
1436 &e4b
->bd_info
->bb_state
);
1437 mb_regenerate_buddy(e4b
);
1441 /* let's maintain fragments counter */
1442 if (left_is_free
&& right_is_free
)
1443 e4b
->bd_info
->bb_fragments
--;
1444 else if (!left_is_free
&& !right_is_free
)
1445 e4b
->bd_info
->bb_fragments
++;
1447 /* buddy[0] == bd_bitmap is a special case, so handle
1448 * it right away and let mb_buddy_mark_free stay free of
1449 * zero order checks.
1450 * Check if neighbours are to be coaleasced,
1451 * adjust bitmap bb_counters and borders appropriately.
1454 first
+= !left_is_free
;
1455 e4b
->bd_info
->bb_counters
[0] += left_is_free
? -1 : 1;
1458 last
-= !right_is_free
;
1459 e4b
->bd_info
->bb_counters
[0] += right_is_free
? -1 : 1;
1463 mb_buddy_mark_free(e4b
, first
>> 1, last
>> 1);
1466 mb_set_largest_free_order(sb
, e4b
->bd_info
);
1467 mb_check_buddy(e4b
);
1470 static int mb_find_extent(struct ext4_buddy
*e4b
, int block
,
1471 int needed
, struct ext4_free_extent
*ex
)
1477 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1480 buddy
= mb_find_buddy(e4b
, 0, &max
);
1481 BUG_ON(buddy
== NULL
);
1482 BUG_ON(block
>= max
);
1483 if (mb_test_bit(block
, buddy
)) {
1490 /* find actual order */
1491 order
= mb_find_order_for_block(e4b
, block
);
1492 block
= block
>> order
;
1494 ex
->fe_len
= 1 << order
;
1495 ex
->fe_start
= block
<< order
;
1496 ex
->fe_group
= e4b
->bd_group
;
1498 /* calc difference from given start */
1499 next
= next
- ex
->fe_start
;
1501 ex
->fe_start
+= next
;
1503 while (needed
> ex
->fe_len
&&
1504 mb_find_buddy(e4b
, order
, &max
)) {
1506 if (block
+ 1 >= max
)
1509 next
= (block
+ 1) * (1 << order
);
1510 if (mb_test_bit(next
, e4b
->bd_bitmap
))
1513 order
= mb_find_order_for_block(e4b
, next
);
1515 block
= next
>> order
;
1516 ex
->fe_len
+= 1 << order
;
1519 BUG_ON(ex
->fe_start
+ ex
->fe_len
> (1 << (e4b
->bd_blkbits
+ 3)));
1523 static int mb_mark_used(struct ext4_buddy
*e4b
, struct ext4_free_extent
*ex
)
1529 int start
= ex
->fe_start
;
1530 int len
= ex
->fe_len
;
1535 BUG_ON(start
+ len
> (e4b
->bd_sb
->s_blocksize
<< 3));
1536 BUG_ON(e4b
->bd_group
!= ex
->fe_group
);
1537 assert_spin_locked(ext4_group_lock_ptr(e4b
->bd_sb
, e4b
->bd_group
));
1538 mb_check_buddy(e4b
);
1539 mb_mark_used_double(e4b
, start
, len
);
1541 e4b
->bd_info
->bb_free
-= len
;
1542 if (e4b
->bd_info
->bb_first_free
== start
)
1543 e4b
->bd_info
->bb_first_free
+= len
;
1545 /* let's maintain fragments counter */
1547 mlen
= !mb_test_bit(start
- 1, e4b
->bd_bitmap
);
1548 if (start
+ len
< EXT4_SB(e4b
->bd_sb
)->s_mb_maxs
[0])
1549 max
= !mb_test_bit(start
+ len
, e4b
->bd_bitmap
);
1551 e4b
->bd_info
->bb_fragments
++;
1552 else if (!mlen
&& !max
)
1553 e4b
->bd_info
->bb_fragments
--;
1555 /* let's maintain buddy itself */
1557 ord
= mb_find_order_for_block(e4b
, start
);
1559 if (((start
>> ord
) << ord
) == start
&& len
>= (1 << ord
)) {
1560 /* the whole chunk may be allocated at once! */
1562 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1563 BUG_ON((start
>> ord
) >= max
);
1564 mb_set_bit(start
>> ord
, buddy
);
1565 e4b
->bd_info
->bb_counters
[ord
]--;
1572 /* store for history */
1574 ret
= len
| (ord
<< 16);
1576 /* we have to split large buddy */
1578 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1579 mb_set_bit(start
>> ord
, buddy
);
1580 e4b
->bd_info
->bb_counters
[ord
]--;
1583 cur
= (start
>> ord
) & ~1U;
1584 buddy
= mb_find_buddy(e4b
, ord
, &max
);
1585 mb_clear_bit(cur
, buddy
);
1586 mb_clear_bit(cur
+ 1, buddy
);
1587 e4b
->bd_info
->bb_counters
[ord
]++;
1588 e4b
->bd_info
->bb_counters
[ord
]++;
1590 mb_set_largest_free_order(e4b
->bd_sb
, e4b
->bd_info
);
1592 ext4_set_bits(e4b
->bd_bitmap
, ex
->fe_start
, len0
);
1593 mb_check_buddy(e4b
);
1599 * Must be called under group lock!
1601 static void ext4_mb_use_best_found(struct ext4_allocation_context
*ac
,
1602 struct ext4_buddy
*e4b
)
1604 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1607 BUG_ON(ac
->ac_b_ex
.fe_group
!= e4b
->bd_group
);
1608 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
1610 ac
->ac_b_ex
.fe_len
= min(ac
->ac_b_ex
.fe_len
, ac
->ac_g_ex
.fe_len
);
1611 ac
->ac_b_ex
.fe_logical
= ac
->ac_g_ex
.fe_logical
;
1612 ret
= mb_mark_used(e4b
, &ac
->ac_b_ex
);
1614 /* preallocation can change ac_b_ex, thus we store actually
1615 * allocated blocks for history */
1616 ac
->ac_f_ex
= ac
->ac_b_ex
;
1618 ac
->ac_status
= AC_STATUS_FOUND
;
1619 ac
->ac_tail
= ret
& 0xffff;
1620 ac
->ac_buddy
= ret
>> 16;
1623 * take the page reference. We want the page to be pinned
1624 * so that we don't get a ext4_mb_init_cache_call for this
1625 * group until we update the bitmap. That would mean we
1626 * double allocate blocks. The reference is dropped
1627 * in ext4_mb_release_context
1629 ac
->ac_bitmap_page
= e4b
->bd_bitmap_page
;
1630 get_page(ac
->ac_bitmap_page
);
1631 ac
->ac_buddy_page
= e4b
->bd_buddy_page
;
1632 get_page(ac
->ac_buddy_page
);
1633 /* store last allocated for subsequent stream allocation */
1634 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
1635 spin_lock(&sbi
->s_md_lock
);
1636 sbi
->s_mb_last_group
= ac
->ac_f_ex
.fe_group
;
1637 sbi
->s_mb_last_start
= ac
->ac_f_ex
.fe_start
;
1638 spin_unlock(&sbi
->s_md_lock
);
1643 * regular allocator, for general purposes allocation
1646 static void ext4_mb_check_limits(struct ext4_allocation_context
*ac
,
1647 struct ext4_buddy
*e4b
,
1650 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1651 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1652 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1653 struct ext4_free_extent ex
;
1656 if (ac
->ac_status
== AC_STATUS_FOUND
)
1659 * We don't want to scan for a whole year
1661 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
&&
1662 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1663 ac
->ac_status
= AC_STATUS_BREAK
;
1668 * Haven't found good chunk so far, let's continue
1670 if (bex
->fe_len
< gex
->fe_len
)
1673 if ((finish_group
|| ac
->ac_found
> sbi
->s_mb_min_to_scan
)
1674 && bex
->fe_group
== e4b
->bd_group
) {
1675 /* recheck chunk's availability - we don't know
1676 * when it was found (within this lock-unlock
1678 max
= mb_find_extent(e4b
, bex
->fe_start
, gex
->fe_len
, &ex
);
1679 if (max
>= gex
->fe_len
) {
1680 ext4_mb_use_best_found(ac
, e4b
);
1687 * The routine checks whether found extent is good enough. If it is,
1688 * then the extent gets marked used and flag is set to the context
1689 * to stop scanning. Otherwise, the extent is compared with the
1690 * previous found extent and if new one is better, then it's stored
1691 * in the context. Later, the best found extent will be used, if
1692 * mballoc can't find good enough extent.
1694 * FIXME: real allocation policy is to be designed yet!
1696 static void ext4_mb_measure_extent(struct ext4_allocation_context
*ac
,
1697 struct ext4_free_extent
*ex
,
1698 struct ext4_buddy
*e4b
)
1700 struct ext4_free_extent
*bex
= &ac
->ac_b_ex
;
1701 struct ext4_free_extent
*gex
= &ac
->ac_g_ex
;
1703 BUG_ON(ex
->fe_len
<= 0);
1704 BUG_ON(ex
->fe_len
> EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1705 BUG_ON(ex
->fe_start
>= EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
1706 BUG_ON(ac
->ac_status
!= AC_STATUS_CONTINUE
);
1711 * The special case - take what you catch first
1713 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
1715 ext4_mb_use_best_found(ac
, e4b
);
1720 * Let's check whether the chuck is good enough
1722 if (ex
->fe_len
== gex
->fe_len
) {
1724 ext4_mb_use_best_found(ac
, e4b
);
1729 * If this is first found extent, just store it in the context
1731 if (bex
->fe_len
== 0) {
1737 * If new found extent is better, store it in the context
1739 if (bex
->fe_len
< gex
->fe_len
) {
1740 /* if the request isn't satisfied, any found extent
1741 * larger than previous best one is better */
1742 if (ex
->fe_len
> bex
->fe_len
)
1744 } else if (ex
->fe_len
> gex
->fe_len
) {
1745 /* if the request is satisfied, then we try to find
1746 * an extent that still satisfy the request, but is
1747 * smaller than previous one */
1748 if (ex
->fe_len
< bex
->fe_len
)
1752 ext4_mb_check_limits(ac
, e4b
, 0);
1755 static noinline_for_stack
1756 int ext4_mb_try_best_found(struct ext4_allocation_context
*ac
,
1757 struct ext4_buddy
*e4b
)
1759 struct ext4_free_extent ex
= ac
->ac_b_ex
;
1760 ext4_group_t group
= ex
.fe_group
;
1764 BUG_ON(ex
.fe_len
<= 0);
1765 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1769 ext4_lock_group(ac
->ac_sb
, group
);
1770 max
= mb_find_extent(e4b
, ex
.fe_start
, ex
.fe_len
, &ex
);
1774 ext4_mb_use_best_found(ac
, e4b
);
1777 ext4_unlock_group(ac
->ac_sb
, group
);
1778 ext4_mb_unload_buddy(e4b
);
1783 static noinline_for_stack
1784 int ext4_mb_find_by_goal(struct ext4_allocation_context
*ac
,
1785 struct ext4_buddy
*e4b
)
1787 ext4_group_t group
= ac
->ac_g_ex
.fe_group
;
1790 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
1791 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1792 struct ext4_free_extent ex
;
1794 if (!(ac
->ac_flags
& EXT4_MB_HINT_TRY_GOAL
))
1796 if (grp
->bb_free
== 0)
1799 err
= ext4_mb_load_buddy(ac
->ac_sb
, group
, e4b
);
1803 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b
->bd_info
))) {
1804 ext4_mb_unload_buddy(e4b
);
1808 ext4_lock_group(ac
->ac_sb
, group
);
1809 max
= mb_find_extent(e4b
, ac
->ac_g_ex
.fe_start
,
1810 ac
->ac_g_ex
.fe_len
, &ex
);
1811 ex
.fe_logical
= 0xDEADFA11; /* debug value */
1813 if (max
>= ac
->ac_g_ex
.fe_len
&& ac
->ac_g_ex
.fe_len
== sbi
->s_stripe
) {
1816 start
= ext4_group_first_block_no(ac
->ac_sb
, e4b
->bd_group
) +
1818 /* use do_div to get remainder (would be 64-bit modulo) */
1819 if (do_div(start
, sbi
->s_stripe
) == 0) {
1822 ext4_mb_use_best_found(ac
, e4b
);
1824 } else if (max
>= ac
->ac_g_ex
.fe_len
) {
1825 BUG_ON(ex
.fe_len
<= 0);
1826 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1827 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1830 ext4_mb_use_best_found(ac
, e4b
);
1831 } else if (max
> 0 && (ac
->ac_flags
& EXT4_MB_HINT_MERGE
)) {
1832 /* Sometimes, caller may want to merge even small
1833 * number of blocks to an existing extent */
1834 BUG_ON(ex
.fe_len
<= 0);
1835 BUG_ON(ex
.fe_group
!= ac
->ac_g_ex
.fe_group
);
1836 BUG_ON(ex
.fe_start
!= ac
->ac_g_ex
.fe_start
);
1839 ext4_mb_use_best_found(ac
, e4b
);
1841 ext4_unlock_group(ac
->ac_sb
, group
);
1842 ext4_mb_unload_buddy(e4b
);
1848 * The routine scans buddy structures (not bitmap!) from given order
1849 * to max order and tries to find big enough chunk to satisfy the req
1851 static noinline_for_stack
1852 void ext4_mb_simple_scan_group(struct ext4_allocation_context
*ac
,
1853 struct ext4_buddy
*e4b
)
1855 struct super_block
*sb
= ac
->ac_sb
;
1856 struct ext4_group_info
*grp
= e4b
->bd_info
;
1862 BUG_ON(ac
->ac_2order
<= 0);
1863 for (i
= ac
->ac_2order
; i
<= sb
->s_blocksize_bits
+ 1; i
++) {
1864 if (grp
->bb_counters
[i
] == 0)
1867 buddy
= mb_find_buddy(e4b
, i
, &max
);
1868 BUG_ON(buddy
== NULL
);
1870 k
= mb_find_next_zero_bit(buddy
, max
, 0);
1875 ac
->ac_b_ex
.fe_len
= 1 << i
;
1876 ac
->ac_b_ex
.fe_start
= k
<< i
;
1877 ac
->ac_b_ex
.fe_group
= e4b
->bd_group
;
1879 ext4_mb_use_best_found(ac
, e4b
);
1881 BUG_ON(ac
->ac_b_ex
.fe_len
!= ac
->ac_g_ex
.fe_len
);
1883 if (EXT4_SB(sb
)->s_mb_stats
)
1884 atomic_inc(&EXT4_SB(sb
)->s_bal_2orders
);
1891 * The routine scans the group and measures all found extents.
1892 * In order to optimize scanning, caller must pass number of
1893 * free blocks in the group, so the routine can know upper limit.
1895 static noinline_for_stack
1896 void ext4_mb_complex_scan_group(struct ext4_allocation_context
*ac
,
1897 struct ext4_buddy
*e4b
)
1899 struct super_block
*sb
= ac
->ac_sb
;
1900 void *bitmap
= e4b
->bd_bitmap
;
1901 struct ext4_free_extent ex
;
1905 free
= e4b
->bd_info
->bb_free
;
1908 i
= e4b
->bd_info
->bb_first_free
;
1910 while (free
&& ac
->ac_status
== AC_STATUS_CONTINUE
) {
1911 i
= mb_find_next_zero_bit(bitmap
,
1912 EXT4_CLUSTERS_PER_GROUP(sb
), i
);
1913 if (i
>= EXT4_CLUSTERS_PER_GROUP(sb
)) {
1915 * IF we have corrupt bitmap, we won't find any
1916 * free blocks even though group info says we
1917 * we have free blocks
1919 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1920 "%d free clusters as per "
1921 "group info. But bitmap says 0",
1926 mb_find_extent(e4b
, i
, ac
->ac_g_ex
.fe_len
, &ex
);
1927 BUG_ON(ex
.fe_len
<= 0);
1928 if (free
< ex
.fe_len
) {
1929 ext4_grp_locked_error(sb
, e4b
->bd_group
, 0, 0,
1930 "%d free clusters as per "
1931 "group info. But got %d blocks",
1934 * The number of free blocks differs. This mostly
1935 * indicate that the bitmap is corrupt. So exit
1936 * without claiming the space.
1940 ex
.fe_logical
= 0xDEADC0DE; /* debug value */
1941 ext4_mb_measure_extent(ac
, &ex
, e4b
);
1947 ext4_mb_check_limits(ac
, e4b
, 1);
1951 * This is a special case for storages like raid5
1952 * we try to find stripe-aligned chunks for stripe-size-multiple requests
1954 static noinline_for_stack
1955 void ext4_mb_scan_aligned(struct ext4_allocation_context
*ac
,
1956 struct ext4_buddy
*e4b
)
1958 struct super_block
*sb
= ac
->ac_sb
;
1959 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
1960 void *bitmap
= e4b
->bd_bitmap
;
1961 struct ext4_free_extent ex
;
1962 ext4_fsblk_t first_group_block
;
1967 BUG_ON(sbi
->s_stripe
== 0);
1969 /* find first stripe-aligned block in group */
1970 first_group_block
= ext4_group_first_block_no(sb
, e4b
->bd_group
);
1972 a
= first_group_block
+ sbi
->s_stripe
- 1;
1973 do_div(a
, sbi
->s_stripe
);
1974 i
= (a
* sbi
->s_stripe
) - first_group_block
;
1976 while (i
< EXT4_CLUSTERS_PER_GROUP(sb
)) {
1977 if (!mb_test_bit(i
, bitmap
)) {
1978 max
= mb_find_extent(e4b
, i
, sbi
->s_stripe
, &ex
);
1979 if (max
>= sbi
->s_stripe
) {
1981 ex
.fe_logical
= 0xDEADF00D; /* debug value */
1983 ext4_mb_use_best_found(ac
, e4b
);
1991 /* This is now called BEFORE we load the buddy bitmap. */
1992 static int ext4_mb_good_group(struct ext4_allocation_context
*ac
,
1993 ext4_group_t group
, int cr
)
1995 unsigned free
, fragments
;
1996 int flex_size
= ext4_flex_bg_size(EXT4_SB(ac
->ac_sb
));
1997 struct ext4_group_info
*grp
= ext4_get_group_info(ac
->ac_sb
, group
);
1999 BUG_ON(cr
< 0 || cr
>= 4);
2001 free
= grp
->bb_free
;
2004 if (cr
<= 2 && free
< ac
->ac_g_ex
.fe_len
)
2007 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp
)))
2010 /* We only do this if the grp has never been initialized */
2011 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
2012 int ret
= ext4_mb_init_group(ac
->ac_sb
, group
);
2017 fragments
= grp
->bb_fragments
;
2023 BUG_ON(ac
->ac_2order
== 0);
2025 /* Avoid using the first bg of a flexgroup for data files */
2026 if ((ac
->ac_flags
& EXT4_MB_HINT_DATA
) &&
2027 (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) &&
2028 ((group
% flex_size
) == 0))
2031 if ((ac
->ac_2order
> ac
->ac_sb
->s_blocksize_bits
+1) ||
2032 (free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2035 if (grp
->bb_largest_free_order
< ac
->ac_2order
)
2040 if ((free
/ fragments
) >= ac
->ac_g_ex
.fe_len
)
2044 if (free
>= ac
->ac_g_ex
.fe_len
)
2056 static noinline_for_stack
int
2057 ext4_mb_regular_allocator(struct ext4_allocation_context
*ac
)
2059 ext4_group_t ngroups
, group
, i
;
2062 struct ext4_sb_info
*sbi
;
2063 struct super_block
*sb
;
2064 struct ext4_buddy e4b
;
2068 ngroups
= ext4_get_groups_count(sb
);
2069 /* non-extent files are limited to low blocks/groups */
2070 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)))
2071 ngroups
= sbi
->s_blockfile_groups
;
2073 BUG_ON(ac
->ac_status
== AC_STATUS_FOUND
);
2075 /* first, try the goal */
2076 err
= ext4_mb_find_by_goal(ac
, &e4b
);
2077 if (err
|| ac
->ac_status
== AC_STATUS_FOUND
)
2080 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
2084 * ac->ac2_order is set only if the fe_len is a power of 2
2085 * if ac2_order is set we also set criteria to 0 so that we
2086 * try exact allocation using buddy.
2088 i
= fls(ac
->ac_g_ex
.fe_len
);
2091 * We search using buddy data only if the order of the request
2092 * is greater than equal to the sbi_s_mb_order2_reqs
2093 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2095 if (i
>= sbi
->s_mb_order2_reqs
) {
2097 * This should tell if fe_len is exactly power of 2
2099 if ((ac
->ac_g_ex
.fe_len
& (~(1 << (i
- 1)))) == 0)
2100 ac
->ac_2order
= i
- 1;
2103 /* if stream allocation is enabled, use global goal */
2104 if (ac
->ac_flags
& EXT4_MB_STREAM_ALLOC
) {
2105 /* TBD: may be hot point */
2106 spin_lock(&sbi
->s_md_lock
);
2107 ac
->ac_g_ex
.fe_group
= sbi
->s_mb_last_group
;
2108 ac
->ac_g_ex
.fe_start
= sbi
->s_mb_last_start
;
2109 spin_unlock(&sbi
->s_md_lock
);
2112 /* Let's just scan groups to find more-less suitable blocks */
2113 cr
= ac
->ac_2order
? 0 : 1;
2115 * cr == 0 try to get exact allocation,
2116 * cr == 3 try to get anything
2119 for (; cr
< 4 && ac
->ac_status
== AC_STATUS_CONTINUE
; cr
++) {
2120 ac
->ac_criteria
= cr
;
2122 * searching for the right group start
2123 * from the goal value specified
2125 group
= ac
->ac_g_ex
.fe_group
;
2127 for (i
= 0; i
< ngroups
; group
++, i
++) {
2130 * Artificially restricted ngroups for non-extent
2131 * files makes group > ngroups possible on first loop.
2133 if (group
>= ngroups
)
2136 /* This now checks without needing the buddy page */
2137 if (!ext4_mb_good_group(ac
, group
, cr
))
2140 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2144 ext4_lock_group(sb
, group
);
2147 * We need to check again after locking the
2150 if (!ext4_mb_good_group(ac
, group
, cr
)) {
2151 ext4_unlock_group(sb
, group
);
2152 ext4_mb_unload_buddy(&e4b
);
2156 ac
->ac_groups_scanned
++;
2157 if (cr
== 0 && ac
->ac_2order
< sb
->s_blocksize_bits
+2)
2158 ext4_mb_simple_scan_group(ac
, &e4b
);
2159 else if (cr
== 1 && sbi
->s_stripe
&&
2160 !(ac
->ac_g_ex
.fe_len
% sbi
->s_stripe
))
2161 ext4_mb_scan_aligned(ac
, &e4b
);
2163 ext4_mb_complex_scan_group(ac
, &e4b
);
2165 ext4_unlock_group(sb
, group
);
2166 ext4_mb_unload_buddy(&e4b
);
2168 if (ac
->ac_status
!= AC_STATUS_CONTINUE
)
2173 if (ac
->ac_b_ex
.fe_len
> 0 && ac
->ac_status
!= AC_STATUS_FOUND
&&
2174 !(ac
->ac_flags
& EXT4_MB_HINT_FIRST
)) {
2176 * We've been searching too long. Let's try to allocate
2177 * the best chunk we've found so far
2180 ext4_mb_try_best_found(ac
, &e4b
);
2181 if (ac
->ac_status
!= AC_STATUS_FOUND
) {
2183 * Someone more lucky has already allocated it.
2184 * The only thing we can do is just take first
2186 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2188 ac
->ac_b_ex
.fe_group
= 0;
2189 ac
->ac_b_ex
.fe_start
= 0;
2190 ac
->ac_b_ex
.fe_len
= 0;
2191 ac
->ac_status
= AC_STATUS_CONTINUE
;
2192 ac
->ac_flags
|= EXT4_MB_HINT_FIRST
;
2194 atomic_inc(&sbi
->s_mb_lost_chunks
);
2202 static void *ext4_mb_seq_groups_start(struct seq_file
*seq
, loff_t
*pos
)
2204 struct super_block
*sb
= seq
->private;
2207 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2210 return (void *) ((unsigned long) group
);
2213 static void *ext4_mb_seq_groups_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2215 struct super_block
*sb
= seq
->private;
2219 if (*pos
< 0 || *pos
>= ext4_get_groups_count(sb
))
2222 return (void *) ((unsigned long) group
);
2225 static int ext4_mb_seq_groups_show(struct seq_file
*seq
, void *v
)
2227 struct super_block
*sb
= seq
->private;
2228 ext4_group_t group
= (ext4_group_t
) ((unsigned long) v
);
2230 int err
, buddy_loaded
= 0;
2231 struct ext4_buddy e4b
;
2232 struct ext4_group_info
*grinfo
;
2234 struct ext4_group_info info
;
2235 ext4_grpblk_t counters
[16];
2240 seq_printf(seq
, "#%-5s: %-5s %-5s %-5s "
2241 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2242 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2243 "group", "free", "frags", "first",
2244 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2245 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2247 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(sg
.info
.bb_counters
[0]) +
2248 sizeof(struct ext4_group_info
);
2249 grinfo
= ext4_get_group_info(sb
, group
);
2250 /* Load the group info in memory only if not already loaded. */
2251 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo
))) {
2252 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
2254 seq_printf(seq
, "#%-5u: I/O error\n", group
);
2260 memcpy(&sg
, ext4_get_group_info(sb
, group
), i
);
2263 ext4_mb_unload_buddy(&e4b
);
2265 seq_printf(seq
, "#%-5u: %-5u %-5u %-5u [", group
, sg
.info
.bb_free
,
2266 sg
.info
.bb_fragments
, sg
.info
.bb_first_free
);
2267 for (i
= 0; i
<= 13; i
++)
2268 seq_printf(seq
, " %-5u", i
<= sb
->s_blocksize_bits
+ 1 ?
2269 sg
.info
.bb_counters
[i
] : 0);
2270 seq_printf(seq
, " ]\n");
2275 static void ext4_mb_seq_groups_stop(struct seq_file
*seq
, void *v
)
2279 static const struct seq_operations ext4_mb_seq_groups_ops
= {
2280 .start
= ext4_mb_seq_groups_start
,
2281 .next
= ext4_mb_seq_groups_next
,
2282 .stop
= ext4_mb_seq_groups_stop
,
2283 .show
= ext4_mb_seq_groups_show
,
2286 static int ext4_mb_seq_groups_open(struct inode
*inode
, struct file
*file
)
2288 struct super_block
*sb
= PDE_DATA(inode
);
2291 rc
= seq_open(file
, &ext4_mb_seq_groups_ops
);
2293 struct seq_file
*m
= file
->private_data
;
2300 static const struct file_operations ext4_mb_seq_groups_fops
= {
2301 .owner
= THIS_MODULE
,
2302 .open
= ext4_mb_seq_groups_open
,
2304 .llseek
= seq_lseek
,
2305 .release
= seq_release
,
2308 static struct kmem_cache
*get_groupinfo_cache(int blocksize_bits
)
2310 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2311 struct kmem_cache
*cachep
= ext4_groupinfo_caches
[cache_index
];
2318 * Allocate the top-level s_group_info array for the specified number
2321 int ext4_mb_alloc_groupinfo(struct super_block
*sb
, ext4_group_t ngroups
)
2323 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2325 struct ext4_group_info
***new_groupinfo
;
2327 size
= (ngroups
+ EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2328 EXT4_DESC_PER_BLOCK_BITS(sb
);
2329 if (size
<= sbi
->s_group_info_size
)
2332 size
= roundup_pow_of_two(sizeof(*sbi
->s_group_info
) * size
);
2333 new_groupinfo
= ext4_kvzalloc(size
, GFP_KERNEL
);
2334 if (!new_groupinfo
) {
2335 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy meta group");
2338 if (sbi
->s_group_info
) {
2339 memcpy(new_groupinfo
, sbi
->s_group_info
,
2340 sbi
->s_group_info_size
* sizeof(*sbi
->s_group_info
));
2341 ext4_kvfree(sbi
->s_group_info
);
2343 sbi
->s_group_info
= new_groupinfo
;
2344 sbi
->s_group_info_size
= size
/ sizeof(*sbi
->s_group_info
);
2345 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2346 sbi
->s_group_info_size
);
2350 /* Create and initialize ext4_group_info data for the given group. */
2351 int ext4_mb_add_groupinfo(struct super_block
*sb
, ext4_group_t group
,
2352 struct ext4_group_desc
*desc
)
2356 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2357 struct ext4_group_info
**meta_group_info
;
2358 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2361 * First check if this group is the first of a reserved block.
2362 * If it's true, we have to allocate a new table of pointers
2363 * to ext4_group_info structures
2365 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2366 metalen
= sizeof(*meta_group_info
) <<
2367 EXT4_DESC_PER_BLOCK_BITS(sb
);
2368 meta_group_info
= kmalloc(metalen
, GFP_KERNEL
);
2369 if (meta_group_info
== NULL
) {
2370 ext4_msg(sb
, KERN_ERR
, "can't allocate mem "
2371 "for a buddy group");
2372 goto exit_meta_group_info
;
2374 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] =
2379 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)];
2380 i
= group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
2382 meta_group_info
[i
] = kmem_cache_zalloc(cachep
, GFP_KERNEL
);
2383 if (meta_group_info
[i
] == NULL
) {
2384 ext4_msg(sb
, KERN_ERR
, "can't allocate buddy mem");
2385 goto exit_group_info
;
2387 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT
,
2388 &(meta_group_info
[i
]->bb_state
));
2391 * initialize bb_free to be able to skip
2392 * empty groups without initialization
2394 if (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2395 meta_group_info
[i
]->bb_free
=
2396 ext4_free_clusters_after_init(sb
, group
, desc
);
2398 meta_group_info
[i
]->bb_free
=
2399 ext4_free_group_clusters(sb
, desc
);
2402 INIT_LIST_HEAD(&meta_group_info
[i
]->bb_prealloc_list
);
2403 init_rwsem(&meta_group_info
[i
]->alloc_sem
);
2404 meta_group_info
[i
]->bb_free_root
= RB_ROOT
;
2405 meta_group_info
[i
]->bb_largest_free_order
= -1; /* uninit */
2409 struct buffer_head
*bh
;
2410 meta_group_info
[i
]->bb_bitmap
=
2411 kmalloc(sb
->s_blocksize
, GFP_KERNEL
);
2412 BUG_ON(meta_group_info
[i
]->bb_bitmap
== NULL
);
2413 bh
= ext4_read_block_bitmap(sb
, group
);
2415 memcpy(meta_group_info
[i
]->bb_bitmap
, bh
->b_data
,
2424 /* If a meta_group_info table has been allocated, release it now */
2425 if (group
% EXT4_DESC_PER_BLOCK(sb
) == 0) {
2426 kfree(sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)]);
2427 sbi
->s_group_info
[group
>> EXT4_DESC_PER_BLOCK_BITS(sb
)] = NULL
;
2429 exit_meta_group_info
:
2431 } /* ext4_mb_add_groupinfo */
2433 static int ext4_mb_init_backend(struct super_block
*sb
)
2435 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2437 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2439 struct ext4_group_desc
*desc
;
2440 struct kmem_cache
*cachep
;
2442 err
= ext4_mb_alloc_groupinfo(sb
, ngroups
);
2446 sbi
->s_buddy_cache
= new_inode(sb
);
2447 if (sbi
->s_buddy_cache
== NULL
) {
2448 ext4_msg(sb
, KERN_ERR
, "can't get new inode");
2451 /* To avoid potentially colliding with an valid on-disk inode number,
2452 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2453 * not in the inode hash, so it should never be found by iget(), but
2454 * this will avoid confusion if it ever shows up during debugging. */
2455 sbi
->s_buddy_cache
->i_ino
= EXT4_BAD_INO
;
2456 EXT4_I(sbi
->s_buddy_cache
)->i_disksize
= 0;
2457 for (i
= 0; i
< ngroups
; i
++) {
2458 desc
= ext4_get_group_desc(sb
, i
, NULL
);
2460 ext4_msg(sb
, KERN_ERR
, "can't read descriptor %u", i
);
2463 if (ext4_mb_add_groupinfo(sb
, i
, desc
) != 0)
2470 cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2472 kmem_cache_free(cachep
, ext4_get_group_info(sb
, i
));
2473 i
= sbi
->s_group_info_size
;
2475 kfree(sbi
->s_group_info
[i
]);
2476 iput(sbi
->s_buddy_cache
);
2478 ext4_kvfree(sbi
->s_group_info
);
2482 static void ext4_groupinfo_destroy_slabs(void)
2486 for (i
= 0; i
< NR_GRPINFO_CACHES
; i
++) {
2487 if (ext4_groupinfo_caches
[i
])
2488 kmem_cache_destroy(ext4_groupinfo_caches
[i
]);
2489 ext4_groupinfo_caches
[i
] = NULL
;
2493 static int ext4_groupinfo_create_slab(size_t size
)
2495 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex
);
2497 int blocksize_bits
= order_base_2(size
);
2498 int cache_index
= blocksize_bits
- EXT4_MIN_BLOCK_LOG_SIZE
;
2499 struct kmem_cache
*cachep
;
2501 if (cache_index
>= NR_GRPINFO_CACHES
)
2504 if (unlikely(cache_index
< 0))
2507 mutex_lock(&ext4_grpinfo_slab_create_mutex
);
2508 if (ext4_groupinfo_caches
[cache_index
]) {
2509 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2510 return 0; /* Already created */
2513 slab_size
= offsetof(struct ext4_group_info
,
2514 bb_counters
[blocksize_bits
+ 2]);
2516 cachep
= kmem_cache_create(ext4_groupinfo_slab_names
[cache_index
],
2517 slab_size
, 0, SLAB_RECLAIM_ACCOUNT
,
2520 ext4_groupinfo_caches
[cache_index
] = cachep
;
2522 mutex_unlock(&ext4_grpinfo_slab_create_mutex
);
2525 "EXT4-fs: no memory for groupinfo slab cache\n");
2532 int ext4_mb_init(struct super_block
*sb
)
2534 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2540 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_offsets
);
2542 sbi
->s_mb_offsets
= kmalloc(i
, GFP_KERNEL
);
2543 if (sbi
->s_mb_offsets
== NULL
) {
2548 i
= (sb
->s_blocksize_bits
+ 2) * sizeof(*sbi
->s_mb_maxs
);
2549 sbi
->s_mb_maxs
= kmalloc(i
, GFP_KERNEL
);
2550 if (sbi
->s_mb_maxs
== NULL
) {
2555 ret
= ext4_groupinfo_create_slab(sb
->s_blocksize
);
2559 /* order 0 is regular bitmap */
2560 sbi
->s_mb_maxs
[0] = sb
->s_blocksize
<< 3;
2561 sbi
->s_mb_offsets
[0] = 0;
2565 max
= sb
->s_blocksize
<< 2;
2567 sbi
->s_mb_offsets
[i
] = offset
;
2568 sbi
->s_mb_maxs
[i
] = max
;
2569 offset
+= 1 << (sb
->s_blocksize_bits
- i
);
2572 } while (i
<= sb
->s_blocksize_bits
+ 1);
2574 spin_lock_init(&sbi
->s_md_lock
);
2575 spin_lock_init(&sbi
->s_bal_lock
);
2577 sbi
->s_mb_max_to_scan
= MB_DEFAULT_MAX_TO_SCAN
;
2578 sbi
->s_mb_min_to_scan
= MB_DEFAULT_MIN_TO_SCAN
;
2579 sbi
->s_mb_stats
= MB_DEFAULT_STATS
;
2580 sbi
->s_mb_stream_request
= MB_DEFAULT_STREAM_THRESHOLD
;
2581 sbi
->s_mb_order2_reqs
= MB_DEFAULT_ORDER2_REQS
;
2583 * The default group preallocation is 512, which for 4k block
2584 * sizes translates to 2 megabytes. However for bigalloc file
2585 * systems, this is probably too big (i.e, if the cluster size
2586 * is 1 megabyte, then group preallocation size becomes half a
2587 * gigabyte!). As a default, we will keep a two megabyte
2588 * group pralloc size for cluster sizes up to 64k, and after
2589 * that, we will force a minimum group preallocation size of
2590 * 32 clusters. This translates to 8 megs when the cluster
2591 * size is 256k, and 32 megs when the cluster size is 1 meg,
2592 * which seems reasonable as a default.
2594 sbi
->s_mb_group_prealloc
= max(MB_DEFAULT_GROUP_PREALLOC
>>
2595 sbi
->s_cluster_bits
, 32);
2597 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2598 * to the lowest multiple of s_stripe which is bigger than
2599 * the s_mb_group_prealloc as determined above. We want
2600 * the preallocation size to be an exact multiple of the
2601 * RAID stripe size so that preallocations don't fragment
2604 if (sbi
->s_stripe
> 1) {
2605 sbi
->s_mb_group_prealloc
= roundup(
2606 sbi
->s_mb_group_prealloc
, sbi
->s_stripe
);
2609 sbi
->s_locality_groups
= alloc_percpu(struct ext4_locality_group
);
2610 if (sbi
->s_locality_groups
== NULL
) {
2612 goto out_free_groupinfo_slab
;
2614 for_each_possible_cpu(i
) {
2615 struct ext4_locality_group
*lg
;
2616 lg
= per_cpu_ptr(sbi
->s_locality_groups
, i
);
2617 mutex_init(&lg
->lg_mutex
);
2618 for (j
= 0; j
< PREALLOC_TB_SIZE
; j
++)
2619 INIT_LIST_HEAD(&lg
->lg_prealloc_list
[j
]);
2620 spin_lock_init(&lg
->lg_prealloc_lock
);
2623 /* init file for buddy data */
2624 ret
= ext4_mb_init_backend(sb
);
2626 goto out_free_locality_groups
;
2629 proc_create_data("mb_groups", S_IRUGO
, sbi
->s_proc
,
2630 &ext4_mb_seq_groups_fops
, sb
);
2634 out_free_locality_groups
:
2635 free_percpu(sbi
->s_locality_groups
);
2636 sbi
->s_locality_groups
= NULL
;
2637 out_free_groupinfo_slab
:
2638 ext4_groupinfo_destroy_slabs();
2640 kfree(sbi
->s_mb_offsets
);
2641 sbi
->s_mb_offsets
= NULL
;
2642 kfree(sbi
->s_mb_maxs
);
2643 sbi
->s_mb_maxs
= NULL
;
2647 /* need to called with the ext4 group lock held */
2648 static void ext4_mb_cleanup_pa(struct ext4_group_info
*grp
)
2650 struct ext4_prealloc_space
*pa
;
2651 struct list_head
*cur
, *tmp
;
2654 list_for_each_safe(cur
, tmp
, &grp
->bb_prealloc_list
) {
2655 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
2656 list_del(&pa
->pa_group_list
);
2658 kmem_cache_free(ext4_pspace_cachep
, pa
);
2661 mb_debug(1, "mballoc: %u PAs left\n", count
);
2665 int ext4_mb_release(struct super_block
*sb
)
2667 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
2669 int num_meta_group_infos
;
2670 struct ext4_group_info
*grinfo
;
2671 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
2672 struct kmem_cache
*cachep
= get_groupinfo_cache(sb
->s_blocksize_bits
);
2675 remove_proc_entry("mb_groups", sbi
->s_proc
);
2677 if (sbi
->s_group_info
) {
2678 for (i
= 0; i
< ngroups
; i
++) {
2679 grinfo
= ext4_get_group_info(sb
, i
);
2681 kfree(grinfo
->bb_bitmap
);
2683 ext4_lock_group(sb
, i
);
2684 ext4_mb_cleanup_pa(grinfo
);
2685 ext4_unlock_group(sb
, i
);
2686 kmem_cache_free(cachep
, grinfo
);
2688 num_meta_group_infos
= (ngroups
+
2689 EXT4_DESC_PER_BLOCK(sb
) - 1) >>
2690 EXT4_DESC_PER_BLOCK_BITS(sb
);
2691 for (i
= 0; i
< num_meta_group_infos
; i
++)
2692 kfree(sbi
->s_group_info
[i
]);
2693 ext4_kvfree(sbi
->s_group_info
);
2695 kfree(sbi
->s_mb_offsets
);
2696 kfree(sbi
->s_mb_maxs
);
2697 if (sbi
->s_buddy_cache
)
2698 iput(sbi
->s_buddy_cache
);
2699 if (sbi
->s_mb_stats
) {
2700 ext4_msg(sb
, KERN_INFO
,
2701 "mballoc: %u blocks %u reqs (%u success)",
2702 atomic_read(&sbi
->s_bal_allocated
),
2703 atomic_read(&sbi
->s_bal_reqs
),
2704 atomic_read(&sbi
->s_bal_success
));
2705 ext4_msg(sb
, KERN_INFO
,
2706 "mballoc: %u extents scanned, %u goal hits, "
2707 "%u 2^N hits, %u breaks, %u lost",
2708 atomic_read(&sbi
->s_bal_ex_scanned
),
2709 atomic_read(&sbi
->s_bal_goals
),
2710 atomic_read(&sbi
->s_bal_2orders
),
2711 atomic_read(&sbi
->s_bal_breaks
),
2712 atomic_read(&sbi
->s_mb_lost_chunks
));
2713 ext4_msg(sb
, KERN_INFO
,
2714 "mballoc: %lu generated and it took %Lu",
2715 sbi
->s_mb_buddies_generated
,
2716 sbi
->s_mb_generation_time
);
2717 ext4_msg(sb
, KERN_INFO
,
2718 "mballoc: %u preallocated, %u discarded",
2719 atomic_read(&sbi
->s_mb_preallocated
),
2720 atomic_read(&sbi
->s_mb_discarded
));
2723 free_percpu(sbi
->s_locality_groups
);
2728 static inline int ext4_issue_discard(struct super_block
*sb
,
2729 ext4_group_t block_group
, ext4_grpblk_t cluster
, int count
)
2731 ext4_fsblk_t discard_block
;
2733 discard_block
= (EXT4_C2B(EXT4_SB(sb
), cluster
) +
2734 ext4_group_first_block_no(sb
, block_group
));
2735 count
= EXT4_C2B(EXT4_SB(sb
), count
);
2736 trace_ext4_discard_blocks(sb
,
2737 (unsigned long long) discard_block
, count
);
2738 return sb_issue_discard(sb
, discard_block
, count
, GFP_NOFS
, 0);
2742 * This function is called by the jbd2 layer once the commit has finished,
2743 * so we know we can free the blocks that were released with that commit.
2745 static void ext4_free_data_callback(struct super_block
*sb
,
2746 struct ext4_journal_cb_entry
*jce
,
2749 struct ext4_free_data
*entry
= (struct ext4_free_data
*)jce
;
2750 struct ext4_buddy e4b
;
2751 struct ext4_group_info
*db
;
2752 int err
, count
= 0, count2
= 0;
2754 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2755 entry
->efd_count
, entry
->efd_group
, entry
);
2757 if (test_opt(sb
, DISCARD
)) {
2758 err
= ext4_issue_discard(sb
, entry
->efd_group
,
2759 entry
->efd_start_cluster
,
2761 if (err
&& err
!= -EOPNOTSUPP
)
2762 ext4_msg(sb
, KERN_WARNING
, "discard request in"
2763 " group:%d block:%d count:%d failed"
2764 " with %d", entry
->efd_group
,
2765 entry
->efd_start_cluster
,
2766 entry
->efd_count
, err
);
2769 err
= ext4_mb_load_buddy(sb
, entry
->efd_group
, &e4b
);
2770 /* we expect to find existing buddy because it's pinned */
2775 /* there are blocks to put in buddy to make them really free */
2776 count
+= entry
->efd_count
;
2778 ext4_lock_group(sb
, entry
->efd_group
);
2779 /* Take it out of per group rb tree */
2780 rb_erase(&entry
->efd_node
, &(db
->bb_free_root
));
2781 mb_free_blocks(NULL
, &e4b
, entry
->efd_start_cluster
, entry
->efd_count
);
2784 * Clear the trimmed flag for the group so that the next
2785 * ext4_trim_fs can trim it.
2786 * If the volume is mounted with -o discard, online discard
2787 * is supported and the free blocks will be trimmed online.
2789 if (!test_opt(sb
, DISCARD
))
2790 EXT4_MB_GRP_CLEAR_TRIMMED(db
);
2792 if (!db
->bb_free_root
.rb_node
) {
2793 /* No more items in the per group rb tree
2794 * balance refcounts from ext4_mb_free_metadata()
2796 page_cache_release(e4b
.bd_buddy_page
);
2797 page_cache_release(e4b
.bd_bitmap_page
);
2799 ext4_unlock_group(sb
, entry
->efd_group
);
2800 kmem_cache_free(ext4_free_data_cachep
, entry
);
2801 ext4_mb_unload_buddy(&e4b
);
2803 mb_debug(1, "freed %u blocks in %u structures\n", count
, count2
);
2806 int __init
ext4_init_mballoc(void)
2808 ext4_pspace_cachep
= KMEM_CACHE(ext4_prealloc_space
,
2809 SLAB_RECLAIM_ACCOUNT
);
2810 if (ext4_pspace_cachep
== NULL
)
2813 ext4_ac_cachep
= KMEM_CACHE(ext4_allocation_context
,
2814 SLAB_RECLAIM_ACCOUNT
);
2815 if (ext4_ac_cachep
== NULL
) {
2816 kmem_cache_destroy(ext4_pspace_cachep
);
2820 ext4_free_data_cachep
= KMEM_CACHE(ext4_free_data
,
2821 SLAB_RECLAIM_ACCOUNT
);
2822 if (ext4_free_data_cachep
== NULL
) {
2823 kmem_cache_destroy(ext4_pspace_cachep
);
2824 kmem_cache_destroy(ext4_ac_cachep
);
2830 void ext4_exit_mballoc(void)
2833 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2834 * before destroying the slab cache.
2837 kmem_cache_destroy(ext4_pspace_cachep
);
2838 kmem_cache_destroy(ext4_ac_cachep
);
2839 kmem_cache_destroy(ext4_free_data_cachep
);
2840 ext4_groupinfo_destroy_slabs();
2845 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2846 * Returns 0 if success or error code
2848 static noinline_for_stack
int
2849 ext4_mb_mark_diskspace_used(struct ext4_allocation_context
*ac
,
2850 handle_t
*handle
, unsigned int reserv_clstrs
)
2852 struct buffer_head
*bitmap_bh
= NULL
;
2853 struct ext4_group_desc
*gdp
;
2854 struct buffer_head
*gdp_bh
;
2855 struct ext4_sb_info
*sbi
;
2856 struct super_block
*sb
;
2860 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
2861 BUG_ON(ac
->ac_b_ex
.fe_len
<= 0);
2867 bitmap_bh
= ext4_read_block_bitmap(sb
, ac
->ac_b_ex
.fe_group
);
2871 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
2876 gdp
= ext4_get_group_desc(sb
, ac
->ac_b_ex
.fe_group
, &gdp_bh
);
2880 ext4_debug("using block group %u(%d)\n", ac
->ac_b_ex
.fe_group
,
2881 ext4_free_group_clusters(sb
, gdp
));
2883 err
= ext4_journal_get_write_access(handle
, gdp_bh
);
2887 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
2889 len
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
2890 if (!ext4_data_block_valid(sbi
, block
, len
)) {
2891 ext4_error(sb
, "Allocating blocks %llu-%llu which overlap "
2892 "fs metadata", block
, block
+len
);
2893 /* File system mounted not to panic on error
2894 * Fix the bitmap and repeat the block allocation
2895 * We leak some of the blocks here.
2897 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2898 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2899 ac
->ac_b_ex
.fe_len
);
2900 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2901 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2907 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
2908 #ifdef AGGRESSIVE_CHECK
2911 for (i
= 0; i
< ac
->ac_b_ex
.fe_len
; i
++) {
2912 BUG_ON(mb_test_bit(ac
->ac_b_ex
.fe_start
+ i
,
2913 bitmap_bh
->b_data
));
2917 ext4_set_bits(bitmap_bh
->b_data
, ac
->ac_b_ex
.fe_start
,
2918 ac
->ac_b_ex
.fe_len
);
2919 if (gdp
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
)) {
2920 gdp
->bg_flags
&= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT
);
2921 ext4_free_group_clusters_set(sb
, gdp
,
2922 ext4_free_clusters_after_init(sb
,
2923 ac
->ac_b_ex
.fe_group
, gdp
));
2925 len
= ext4_free_group_clusters(sb
, gdp
) - ac
->ac_b_ex
.fe_len
;
2926 ext4_free_group_clusters_set(sb
, gdp
, len
);
2927 ext4_block_bitmap_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
, bitmap_bh
);
2928 ext4_group_desc_csum_set(sb
, ac
->ac_b_ex
.fe_group
, gdp
);
2930 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
2931 percpu_counter_sub(&sbi
->s_freeclusters_counter
, ac
->ac_b_ex
.fe_len
);
2933 * Now reduce the dirty block count also. Should not go negative
2935 if (!(ac
->ac_flags
& EXT4_MB_DELALLOC_RESERVED
))
2936 /* release all the reserved blocks if non delalloc */
2937 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
2940 if (sbi
->s_log_groups_per_flex
) {
2941 ext4_group_t flex_group
= ext4_flex_group(sbi
,
2942 ac
->ac_b_ex
.fe_group
);
2943 atomic64_sub(ac
->ac_b_ex
.fe_len
,
2944 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
2947 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
2950 err
= ext4_handle_dirty_metadata(handle
, NULL
, gdp_bh
);
2958 * here we normalize request for locality group
2959 * Group request are normalized to s_mb_group_prealloc, which goes to
2960 * s_strip if we set the same via mount option.
2961 * s_mb_group_prealloc can be configured via
2962 * /sys/fs/ext4/<partition>/mb_group_prealloc
2964 * XXX: should we try to preallocate more than the group has now?
2966 static void ext4_mb_normalize_group_request(struct ext4_allocation_context
*ac
)
2968 struct super_block
*sb
= ac
->ac_sb
;
2969 struct ext4_locality_group
*lg
= ac
->ac_lg
;
2972 ac
->ac_g_ex
.fe_len
= EXT4_SB(sb
)->s_mb_group_prealloc
;
2973 mb_debug(1, "#%u: goal %u blocks for locality group\n",
2974 current
->pid
, ac
->ac_g_ex
.fe_len
);
2978 * Normalization means making request better in terms of
2979 * size and alignment
2981 static noinline_for_stack
void
2982 ext4_mb_normalize_request(struct ext4_allocation_context
*ac
,
2983 struct ext4_allocation_request
*ar
)
2985 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
2988 loff_t size
, start_off
;
2989 loff_t orig_size __maybe_unused
;
2991 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
2992 struct ext4_prealloc_space
*pa
;
2994 /* do normalize only data requests, metadata requests
2995 do not need preallocation */
2996 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
2999 /* sometime caller may want exact blocks */
3000 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
3003 /* caller may indicate that preallocation isn't
3004 * required (it's a tail, for example) */
3005 if (ac
->ac_flags
& EXT4_MB_HINT_NOPREALLOC
)
3008 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
) {
3009 ext4_mb_normalize_group_request(ac
);
3013 bsbits
= ac
->ac_sb
->s_blocksize_bits
;
3015 /* first, let's learn actual file size
3016 * given current request is allocated */
3017 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
3018 size
= size
<< bsbits
;
3019 if (size
< i_size_read(ac
->ac_inode
))
3020 size
= i_size_read(ac
->ac_inode
);
3023 /* max size of free chunks */
3026 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3027 (req <= (size) || max <= (chunk_size))
3029 /* first, try to predict filesize */
3030 /* XXX: should this table be tunable? */
3032 if (size
<= 16 * 1024) {
3034 } else if (size
<= 32 * 1024) {
3036 } else if (size
<= 64 * 1024) {
3038 } else if (size
<= 128 * 1024) {
3040 } else if (size
<= 256 * 1024) {
3042 } else if (size
<= 512 * 1024) {
3044 } else if (size
<= 1024 * 1024) {
3046 } else if (NRL_CHECK_SIZE(size
, 4 * 1024 * 1024, max
, 2 * 1024)) {
3047 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3048 (21 - bsbits
)) << 21;
3049 size
= 2 * 1024 * 1024;
3050 } else if (NRL_CHECK_SIZE(size
, 8 * 1024 * 1024, max
, 4 * 1024)) {
3051 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3052 (22 - bsbits
)) << 22;
3053 size
= 4 * 1024 * 1024;
3054 } else if (NRL_CHECK_SIZE(ac
->ac_o_ex
.fe_len
,
3055 (8<<20)>>bsbits
, max
, 8 * 1024)) {
3056 start_off
= ((loff_t
)ac
->ac_o_ex
.fe_logical
>>
3057 (23 - bsbits
)) << 23;
3058 size
= 8 * 1024 * 1024;
3060 start_off
= (loff_t
)ac
->ac_o_ex
.fe_logical
<< bsbits
;
3061 size
= ac
->ac_o_ex
.fe_len
<< bsbits
;
3063 size
= size
>> bsbits
;
3064 start
= start_off
>> bsbits
;
3066 /* don't cover already allocated blocks in selected range */
3067 if (ar
->pleft
&& start
<= ar
->lleft
) {
3068 size
-= ar
->lleft
+ 1 - start
;
3069 start
= ar
->lleft
+ 1;
3071 if (ar
->pright
&& start
+ size
- 1 >= ar
->lright
)
3072 size
-= start
+ size
- ar
->lright
;
3076 /* check we don't cross already preallocated blocks */
3078 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3083 spin_lock(&pa
->pa_lock
);
3084 if (pa
->pa_deleted
) {
3085 spin_unlock(&pa
->pa_lock
);
3089 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3092 /* PA must not overlap original request */
3093 BUG_ON(!(ac
->ac_o_ex
.fe_logical
>= pa_end
||
3094 ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
));
3096 /* skip PAs this normalized request doesn't overlap with */
3097 if (pa
->pa_lstart
>= end
|| pa_end
<= start
) {
3098 spin_unlock(&pa
->pa_lock
);
3101 BUG_ON(pa
->pa_lstart
<= start
&& pa_end
>= end
);
3103 /* adjust start or end to be adjacent to this pa */
3104 if (pa_end
<= ac
->ac_o_ex
.fe_logical
) {
3105 BUG_ON(pa_end
< start
);
3107 } else if (pa
->pa_lstart
> ac
->ac_o_ex
.fe_logical
) {
3108 BUG_ON(pa
->pa_lstart
> end
);
3109 end
= pa
->pa_lstart
;
3111 spin_unlock(&pa
->pa_lock
);
3116 /* XXX: extra loop to check we really don't overlap preallocations */
3118 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3121 spin_lock(&pa
->pa_lock
);
3122 if (pa
->pa_deleted
== 0) {
3123 pa_end
= pa
->pa_lstart
+ EXT4_C2B(EXT4_SB(ac
->ac_sb
),
3125 BUG_ON(!(start
>= pa_end
|| end
<= pa
->pa_lstart
));
3127 spin_unlock(&pa
->pa_lock
);
3131 if (start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3132 start
> ac
->ac_o_ex
.fe_logical
) {
3133 ext4_msg(ac
->ac_sb
, KERN_ERR
,
3134 "start %lu, size %lu, fe_logical %lu",
3135 (unsigned long) start
, (unsigned long) size
,
3136 (unsigned long) ac
->ac_o_ex
.fe_logical
);
3138 BUG_ON(start
+ size
<= ac
->ac_o_ex
.fe_logical
&&
3139 start
> ac
->ac_o_ex
.fe_logical
);
3140 BUG_ON(size
<= 0 || size
> EXT4_CLUSTERS_PER_GROUP(ac
->ac_sb
));
3142 /* now prepare goal request */
3144 /* XXX: is it better to align blocks WRT to logical
3145 * placement or satisfy big request as is */
3146 ac
->ac_g_ex
.fe_logical
= start
;
3147 ac
->ac_g_ex
.fe_len
= EXT4_NUM_B2C(sbi
, size
);
3149 /* define goal start in order to merge */
3150 if (ar
->pright
&& (ar
->lright
== (start
+ size
))) {
3151 /* merge to the right */
3152 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pright
- size
,
3153 &ac
->ac_f_ex
.fe_group
,
3154 &ac
->ac_f_ex
.fe_start
);
3155 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3157 if (ar
->pleft
&& (ar
->lleft
+ 1 == start
)) {
3158 /* merge to the left */
3159 ext4_get_group_no_and_offset(ac
->ac_sb
, ar
->pleft
+ 1,
3160 &ac
->ac_f_ex
.fe_group
,
3161 &ac
->ac_f_ex
.fe_start
);
3162 ac
->ac_flags
|= EXT4_MB_HINT_TRY_GOAL
;
3165 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size
,
3166 (unsigned) orig_size
, (unsigned) start
);
3169 static void ext4_mb_collect_stats(struct ext4_allocation_context
*ac
)
3171 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3173 if (sbi
->s_mb_stats
&& ac
->ac_g_ex
.fe_len
> 1) {
3174 atomic_inc(&sbi
->s_bal_reqs
);
3175 atomic_add(ac
->ac_b_ex
.fe_len
, &sbi
->s_bal_allocated
);
3176 if (ac
->ac_b_ex
.fe_len
>= ac
->ac_o_ex
.fe_len
)
3177 atomic_inc(&sbi
->s_bal_success
);
3178 atomic_add(ac
->ac_found
, &sbi
->s_bal_ex_scanned
);
3179 if (ac
->ac_g_ex
.fe_start
== ac
->ac_b_ex
.fe_start
&&
3180 ac
->ac_g_ex
.fe_group
== ac
->ac_b_ex
.fe_group
)
3181 atomic_inc(&sbi
->s_bal_goals
);
3182 if (ac
->ac_found
> sbi
->s_mb_max_to_scan
)
3183 atomic_inc(&sbi
->s_bal_breaks
);
3186 if (ac
->ac_op
== EXT4_MB_HISTORY_ALLOC
)
3187 trace_ext4_mballoc_alloc(ac
);
3189 trace_ext4_mballoc_prealloc(ac
);
3193 * Called on failure; free up any blocks from the inode PA for this
3194 * context. We don't need this for MB_GROUP_PA because we only change
3195 * pa_free in ext4_mb_release_context(), but on failure, we've already
3196 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3198 static void ext4_discard_allocated_blocks(struct ext4_allocation_context
*ac
)
3200 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
3202 if (pa
&& pa
->pa_type
== MB_INODE_PA
)
3203 pa
->pa_free
+= ac
->ac_b_ex
.fe_len
;
3207 * use blocks preallocated to inode
3209 static void ext4_mb_use_inode_pa(struct ext4_allocation_context
*ac
,
3210 struct ext4_prealloc_space
*pa
)
3212 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3217 /* found preallocated blocks, use them */
3218 start
= pa
->pa_pstart
+ (ac
->ac_o_ex
.fe_logical
- pa
->pa_lstart
);
3219 end
= min(pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
),
3220 start
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
));
3221 len
= EXT4_NUM_B2C(sbi
, end
- start
);
3222 ext4_get_group_no_and_offset(ac
->ac_sb
, start
, &ac
->ac_b_ex
.fe_group
,
3223 &ac
->ac_b_ex
.fe_start
);
3224 ac
->ac_b_ex
.fe_len
= len
;
3225 ac
->ac_status
= AC_STATUS_FOUND
;
3228 BUG_ON(start
< pa
->pa_pstart
);
3229 BUG_ON(end
> pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
));
3230 BUG_ON(pa
->pa_free
< len
);
3233 mb_debug(1, "use %llu/%u from inode pa %p\n", start
, len
, pa
);
3237 * use blocks preallocated to locality group
3239 static void ext4_mb_use_group_pa(struct ext4_allocation_context
*ac
,
3240 struct ext4_prealloc_space
*pa
)
3242 unsigned int len
= ac
->ac_o_ex
.fe_len
;
3244 ext4_get_group_no_and_offset(ac
->ac_sb
, pa
->pa_pstart
,
3245 &ac
->ac_b_ex
.fe_group
,
3246 &ac
->ac_b_ex
.fe_start
);
3247 ac
->ac_b_ex
.fe_len
= len
;
3248 ac
->ac_status
= AC_STATUS_FOUND
;
3251 /* we don't correct pa_pstart or pa_plen here to avoid
3252 * possible race when the group is being loaded concurrently
3253 * instead we correct pa later, after blocks are marked
3254 * in on-disk bitmap -- see ext4_mb_release_context()
3255 * Other CPUs are prevented from allocating from this pa by lg_mutex
3257 mb_debug(1, "use %u/%u from group pa %p\n", pa
->pa_lstart
-len
, len
, pa
);
3261 * Return the prealloc space that have minimal distance
3262 * from the goal block. @cpa is the prealloc
3263 * space that is having currently known minimal distance
3264 * from the goal block.
3266 static struct ext4_prealloc_space
*
3267 ext4_mb_check_group_pa(ext4_fsblk_t goal_block
,
3268 struct ext4_prealloc_space
*pa
,
3269 struct ext4_prealloc_space
*cpa
)
3271 ext4_fsblk_t cur_distance
, new_distance
;
3274 atomic_inc(&pa
->pa_count
);
3277 cur_distance
= abs(goal_block
- cpa
->pa_pstart
);
3278 new_distance
= abs(goal_block
- pa
->pa_pstart
);
3280 if (cur_distance
<= new_distance
)
3283 /* drop the previous reference */
3284 atomic_dec(&cpa
->pa_count
);
3285 atomic_inc(&pa
->pa_count
);
3290 * search goal blocks in preallocated space
3292 static noinline_for_stack
int
3293 ext4_mb_use_preallocated(struct ext4_allocation_context
*ac
)
3295 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
3297 struct ext4_inode_info
*ei
= EXT4_I(ac
->ac_inode
);
3298 struct ext4_locality_group
*lg
;
3299 struct ext4_prealloc_space
*pa
, *cpa
= NULL
;
3300 ext4_fsblk_t goal_block
;
3302 /* only data can be preallocated */
3303 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
3306 /* first, try per-file preallocation */
3308 list_for_each_entry_rcu(pa
, &ei
->i_prealloc_list
, pa_inode_list
) {
3310 /* all fields in this condition don't change,
3311 * so we can skip locking for them */
3312 if (ac
->ac_o_ex
.fe_logical
< pa
->pa_lstart
||
3313 ac
->ac_o_ex
.fe_logical
>= (pa
->pa_lstart
+
3314 EXT4_C2B(sbi
, pa
->pa_len
)))
3317 /* non-extent files can't have physical blocks past 2^32 */
3318 if (!(ext4_test_inode_flag(ac
->ac_inode
, EXT4_INODE_EXTENTS
)) &&
3319 (pa
->pa_pstart
+ EXT4_C2B(sbi
, pa
->pa_len
) >
3320 EXT4_MAX_BLOCK_FILE_PHYS
))
3323 /* found preallocated blocks, use them */
3324 spin_lock(&pa
->pa_lock
);
3325 if (pa
->pa_deleted
== 0 && pa
->pa_free
) {
3326 atomic_inc(&pa
->pa_count
);
3327 ext4_mb_use_inode_pa(ac
, pa
);
3328 spin_unlock(&pa
->pa_lock
);
3329 ac
->ac_criteria
= 10;
3333 spin_unlock(&pa
->pa_lock
);
3337 /* can we use group allocation? */
3338 if (!(ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
))
3341 /* inode may have no locality group for some reason */
3345 order
= fls(ac
->ac_o_ex
.fe_len
) - 1;
3346 if (order
> PREALLOC_TB_SIZE
- 1)
3347 /* The max size of hash table is PREALLOC_TB_SIZE */
3348 order
= PREALLOC_TB_SIZE
- 1;
3350 goal_block
= ext4_grp_offs_to_block(ac
->ac_sb
, &ac
->ac_g_ex
);
3352 * search for the prealloc space that is having
3353 * minimal distance from the goal block.
3355 for (i
= order
; i
< PREALLOC_TB_SIZE
; i
++) {
3357 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[i
],
3359 spin_lock(&pa
->pa_lock
);
3360 if (pa
->pa_deleted
== 0 &&
3361 pa
->pa_free
>= ac
->ac_o_ex
.fe_len
) {
3363 cpa
= ext4_mb_check_group_pa(goal_block
,
3366 spin_unlock(&pa
->pa_lock
);
3371 ext4_mb_use_group_pa(ac
, cpa
);
3372 ac
->ac_criteria
= 20;
3379 * the function goes through all block freed in the group
3380 * but not yet committed and marks them used in in-core bitmap.
3381 * buddy must be generated from this bitmap
3382 * Need to be called with the ext4 group lock held
3384 static void ext4_mb_generate_from_freelist(struct super_block
*sb
, void *bitmap
,
3388 struct ext4_group_info
*grp
;
3389 struct ext4_free_data
*entry
;
3391 grp
= ext4_get_group_info(sb
, group
);
3392 n
= rb_first(&(grp
->bb_free_root
));
3395 entry
= rb_entry(n
, struct ext4_free_data
, efd_node
);
3396 ext4_set_bits(bitmap
, entry
->efd_start_cluster
, entry
->efd_count
);
3403 * the function goes through all preallocation in this group and marks them
3404 * used in in-core bitmap. buddy must be generated from this bitmap
3405 * Need to be called with ext4 group lock held
3407 static noinline_for_stack
3408 void ext4_mb_generate_from_pa(struct super_block
*sb
, void *bitmap
,
3411 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3412 struct ext4_prealloc_space
*pa
;
3413 struct list_head
*cur
;
3414 ext4_group_t groupnr
;
3415 ext4_grpblk_t start
;
3416 int preallocated
= 0;
3419 /* all form of preallocation discards first load group,
3420 * so the only competing code is preallocation use.
3421 * we don't need any locking here
3422 * notice we do NOT ignore preallocations with pa_deleted
3423 * otherwise we could leave used blocks available for
3424 * allocation in buddy when concurrent ext4_mb_put_pa()
3425 * is dropping preallocation
3427 list_for_each(cur
, &grp
->bb_prealloc_list
) {
3428 pa
= list_entry(cur
, struct ext4_prealloc_space
, pa_group_list
);
3429 spin_lock(&pa
->pa_lock
);
3430 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
3433 spin_unlock(&pa
->pa_lock
);
3434 if (unlikely(len
== 0))
3436 BUG_ON(groupnr
!= group
);
3437 ext4_set_bits(bitmap
, start
, len
);
3438 preallocated
+= len
;
3440 mb_debug(1, "prellocated %u for group %u\n", preallocated
, group
);
3443 static void ext4_mb_pa_callback(struct rcu_head
*head
)
3445 struct ext4_prealloc_space
*pa
;
3446 pa
= container_of(head
, struct ext4_prealloc_space
, u
.pa_rcu
);
3448 BUG_ON(atomic_read(&pa
->pa_count
));
3449 BUG_ON(pa
->pa_deleted
== 0);
3450 kmem_cache_free(ext4_pspace_cachep
, pa
);
3454 * drops a reference to preallocated space descriptor
3455 * if this was the last reference and the space is consumed
3457 static void ext4_mb_put_pa(struct ext4_allocation_context
*ac
,
3458 struct super_block
*sb
, struct ext4_prealloc_space
*pa
)
3461 ext4_fsblk_t grp_blk
;
3463 /* in this short window concurrent discard can set pa_deleted */
3464 spin_lock(&pa
->pa_lock
);
3465 if (!atomic_dec_and_test(&pa
->pa_count
) || pa
->pa_free
!= 0) {
3466 spin_unlock(&pa
->pa_lock
);
3470 if (pa
->pa_deleted
== 1) {
3471 spin_unlock(&pa
->pa_lock
);
3476 spin_unlock(&pa
->pa_lock
);
3478 grp_blk
= pa
->pa_pstart
;
3480 * If doing group-based preallocation, pa_pstart may be in the
3481 * next group when pa is used up
3483 if (pa
->pa_type
== MB_GROUP_PA
)
3486 grp
= ext4_get_group_number(sb
, grp_blk
);
3491 * P1 (buddy init) P2 (regular allocation)
3492 * find block B in PA
3493 * copy on-disk bitmap to buddy
3494 * mark B in on-disk bitmap
3495 * drop PA from group
3496 * mark all PAs in buddy
3498 * thus, P1 initializes buddy with B available. to prevent this
3499 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3502 ext4_lock_group(sb
, grp
);
3503 list_del(&pa
->pa_group_list
);
3504 ext4_unlock_group(sb
, grp
);
3506 spin_lock(pa
->pa_obj_lock
);
3507 list_del_rcu(&pa
->pa_inode_list
);
3508 spin_unlock(pa
->pa_obj_lock
);
3510 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3514 * creates new preallocated space for given inode
3516 static noinline_for_stack
int
3517 ext4_mb_new_inode_pa(struct ext4_allocation_context
*ac
)
3519 struct super_block
*sb
= ac
->ac_sb
;
3520 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3521 struct ext4_prealloc_space
*pa
;
3522 struct ext4_group_info
*grp
;
3523 struct ext4_inode_info
*ei
;
3525 /* preallocate only when found space is larger then requested */
3526 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3527 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3528 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3530 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3534 if (ac
->ac_b_ex
.fe_len
< ac
->ac_g_ex
.fe_len
) {
3540 /* we can't allocate as much as normalizer wants.
3541 * so, found space must get proper lstart
3542 * to cover original request */
3543 BUG_ON(ac
->ac_g_ex
.fe_logical
> ac
->ac_o_ex
.fe_logical
);
3544 BUG_ON(ac
->ac_g_ex
.fe_len
< ac
->ac_o_ex
.fe_len
);
3546 /* we're limited by original request in that
3547 * logical block must be covered any way
3548 * winl is window we can move our chunk within */
3549 winl
= ac
->ac_o_ex
.fe_logical
- ac
->ac_g_ex
.fe_logical
;
3551 /* also, we should cover whole original request */
3552 wins
= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
- ac
->ac_o_ex
.fe_len
);
3554 /* the smallest one defines real window */
3555 win
= min(winl
, wins
);
3557 offs
= ac
->ac_o_ex
.fe_logical
%
3558 EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
3559 if (offs
&& offs
< win
)
3562 ac
->ac_b_ex
.fe_logical
= ac
->ac_o_ex
.fe_logical
-
3563 EXT4_NUM_B2C(sbi
, win
);
3564 BUG_ON(ac
->ac_o_ex
.fe_logical
< ac
->ac_b_ex
.fe_logical
);
3565 BUG_ON(ac
->ac_o_ex
.fe_len
> ac
->ac_b_ex
.fe_len
);
3568 /* preallocation can change ac_b_ex, thus we store actually
3569 * allocated blocks for history */
3570 ac
->ac_f_ex
= ac
->ac_b_ex
;
3572 pa
->pa_lstart
= ac
->ac_b_ex
.fe_logical
;
3573 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3574 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3575 pa
->pa_free
= pa
->pa_len
;
3576 atomic_set(&pa
->pa_count
, 1);
3577 spin_lock_init(&pa
->pa_lock
);
3578 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3579 INIT_LIST_HEAD(&pa
->pa_group_list
);
3581 pa
->pa_type
= MB_INODE_PA
;
3583 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa
,
3584 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3585 trace_ext4_mb_new_inode_pa(ac
, pa
);
3587 ext4_mb_use_inode_pa(ac
, pa
);
3588 atomic_add(pa
->pa_free
, &sbi
->s_mb_preallocated
);
3590 ei
= EXT4_I(ac
->ac_inode
);
3591 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3593 pa
->pa_obj_lock
= &ei
->i_prealloc_lock
;
3594 pa
->pa_inode
= ac
->ac_inode
;
3596 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3597 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3598 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3600 spin_lock(pa
->pa_obj_lock
);
3601 list_add_rcu(&pa
->pa_inode_list
, &ei
->i_prealloc_list
);
3602 spin_unlock(pa
->pa_obj_lock
);
3608 * creates new preallocated space for locality group inodes belongs to
3610 static noinline_for_stack
int
3611 ext4_mb_new_group_pa(struct ext4_allocation_context
*ac
)
3613 struct super_block
*sb
= ac
->ac_sb
;
3614 struct ext4_locality_group
*lg
;
3615 struct ext4_prealloc_space
*pa
;
3616 struct ext4_group_info
*grp
;
3618 /* preallocate only when found space is larger then requested */
3619 BUG_ON(ac
->ac_o_ex
.fe_len
>= ac
->ac_b_ex
.fe_len
);
3620 BUG_ON(ac
->ac_status
!= AC_STATUS_FOUND
);
3621 BUG_ON(!S_ISREG(ac
->ac_inode
->i_mode
));
3623 BUG_ON(ext4_pspace_cachep
== NULL
);
3624 pa
= kmem_cache_alloc(ext4_pspace_cachep
, GFP_NOFS
);
3628 /* preallocation can change ac_b_ex, thus we store actually
3629 * allocated blocks for history */
3630 ac
->ac_f_ex
= ac
->ac_b_ex
;
3632 pa
->pa_pstart
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
3633 pa
->pa_lstart
= pa
->pa_pstart
;
3634 pa
->pa_len
= ac
->ac_b_ex
.fe_len
;
3635 pa
->pa_free
= pa
->pa_len
;
3636 atomic_set(&pa
->pa_count
, 1);
3637 spin_lock_init(&pa
->pa_lock
);
3638 INIT_LIST_HEAD(&pa
->pa_inode_list
);
3639 INIT_LIST_HEAD(&pa
->pa_group_list
);
3641 pa
->pa_type
= MB_GROUP_PA
;
3643 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa
,
3644 pa
->pa_pstart
, pa
->pa_len
, pa
->pa_lstart
);
3645 trace_ext4_mb_new_group_pa(ac
, pa
);
3647 ext4_mb_use_group_pa(ac
, pa
);
3648 atomic_add(pa
->pa_free
, &EXT4_SB(sb
)->s_mb_preallocated
);
3650 grp
= ext4_get_group_info(sb
, ac
->ac_b_ex
.fe_group
);
3654 pa
->pa_obj_lock
= &lg
->lg_prealloc_lock
;
3655 pa
->pa_inode
= NULL
;
3657 ext4_lock_group(sb
, ac
->ac_b_ex
.fe_group
);
3658 list_add(&pa
->pa_group_list
, &grp
->bb_prealloc_list
);
3659 ext4_unlock_group(sb
, ac
->ac_b_ex
.fe_group
);
3662 * We will later add the new pa to the right bucket
3663 * after updating the pa_free in ext4_mb_release_context
3668 static int ext4_mb_new_preallocation(struct ext4_allocation_context
*ac
)
3672 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
3673 err
= ext4_mb_new_group_pa(ac
);
3675 err
= ext4_mb_new_inode_pa(ac
);
3680 * finds all unused blocks in on-disk bitmap, frees them in
3681 * in-core bitmap and buddy.
3682 * @pa must be unlinked from inode and group lists, so that
3683 * nobody else can find/use it.
3684 * the caller MUST hold group/inode locks.
3685 * TODO: optimize the case when there are no in-core structures yet
3687 static noinline_for_stack
int
3688 ext4_mb_release_inode_pa(struct ext4_buddy
*e4b
, struct buffer_head
*bitmap_bh
,
3689 struct ext4_prealloc_space
*pa
)
3691 struct super_block
*sb
= e4b
->bd_sb
;
3692 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
3697 unsigned long long grp_blk_start
;
3701 BUG_ON(pa
->pa_deleted
== 0);
3702 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3703 grp_blk_start
= pa
->pa_pstart
- EXT4_C2B(sbi
, bit
);
3704 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3705 end
= bit
+ pa
->pa_len
;
3708 bit
= mb_find_next_zero_bit(bitmap_bh
->b_data
, end
, bit
);
3711 next
= mb_find_next_bit(bitmap_bh
->b_data
, end
, bit
);
3712 mb_debug(1, " free preallocated %u/%u in group %u\n",
3713 (unsigned) ext4_group_first_block_no(sb
, group
) + bit
,
3714 (unsigned) next
- bit
, (unsigned) group
);
3717 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, next
- bit
);
3718 trace_ext4_mb_release_inode_pa(pa
, (grp_blk_start
+
3719 EXT4_C2B(sbi
, bit
)),
3721 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, next
- bit
);
3724 if (free
!= pa
->pa_free
) {
3725 ext4_msg(e4b
->bd_sb
, KERN_CRIT
,
3726 "pa %p: logic %lu, phys. %lu, len %lu",
3727 pa
, (unsigned long) pa
->pa_lstart
,
3728 (unsigned long) pa
->pa_pstart
,
3729 (unsigned long) pa
->pa_len
);
3730 ext4_grp_locked_error(sb
, group
, 0, 0, "free %u, pa_free %u",
3733 * pa is already deleted so we use the value obtained
3734 * from the bitmap and continue.
3737 atomic_add(free
, &sbi
->s_mb_discarded
);
3742 static noinline_for_stack
int
3743 ext4_mb_release_group_pa(struct ext4_buddy
*e4b
,
3744 struct ext4_prealloc_space
*pa
)
3746 struct super_block
*sb
= e4b
->bd_sb
;
3750 trace_ext4_mb_release_group_pa(sb
, pa
);
3751 BUG_ON(pa
->pa_deleted
== 0);
3752 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
, &group
, &bit
);
3753 BUG_ON(group
!= e4b
->bd_group
&& pa
->pa_len
!= 0);
3754 mb_free_blocks(pa
->pa_inode
, e4b
, bit
, pa
->pa_len
);
3755 atomic_add(pa
->pa_len
, &EXT4_SB(sb
)->s_mb_discarded
);
3756 trace_ext4_mballoc_discard(sb
, NULL
, group
, bit
, pa
->pa_len
);
3762 * releases all preallocations in given group
3764 * first, we need to decide discard policy:
3765 * - when do we discard
3767 * - how many do we discard
3768 * 1) how many requested
3770 static noinline_for_stack
int
3771 ext4_mb_discard_group_preallocations(struct super_block
*sb
,
3772 ext4_group_t group
, int needed
)
3774 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, group
);
3775 struct buffer_head
*bitmap_bh
= NULL
;
3776 struct ext4_prealloc_space
*pa
, *tmp
;
3777 struct list_head list
;
3778 struct ext4_buddy e4b
;
3783 mb_debug(1, "discard preallocation for group %u\n", group
);
3785 if (list_empty(&grp
->bb_prealloc_list
))
3788 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3789 if (bitmap_bh
== NULL
) {
3790 ext4_error(sb
, "Error reading block bitmap for %u", group
);
3794 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3796 ext4_error(sb
, "Error loading buddy information for %u", group
);
3802 needed
= EXT4_CLUSTERS_PER_GROUP(sb
) + 1;
3804 INIT_LIST_HEAD(&list
);
3806 ext4_lock_group(sb
, group
);
3807 list_for_each_entry_safe(pa
, tmp
,
3808 &grp
->bb_prealloc_list
, pa_group_list
) {
3809 spin_lock(&pa
->pa_lock
);
3810 if (atomic_read(&pa
->pa_count
)) {
3811 spin_unlock(&pa
->pa_lock
);
3815 if (pa
->pa_deleted
) {
3816 spin_unlock(&pa
->pa_lock
);
3820 /* seems this one can be freed ... */
3823 /* we can trust pa_free ... */
3824 free
+= pa
->pa_free
;
3826 spin_unlock(&pa
->pa_lock
);
3828 list_del(&pa
->pa_group_list
);
3829 list_add(&pa
->u
.pa_tmp_list
, &list
);
3832 /* if we still need more blocks and some PAs were used, try again */
3833 if (free
< needed
&& busy
) {
3835 ext4_unlock_group(sb
, group
);
3840 /* found anything to free? */
3841 if (list_empty(&list
)) {
3846 /* now free all selected PAs */
3847 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3849 /* remove from object (inode or locality group) */
3850 spin_lock(pa
->pa_obj_lock
);
3851 list_del_rcu(&pa
->pa_inode_list
);
3852 spin_unlock(pa
->pa_obj_lock
);
3854 if (pa
->pa_type
== MB_GROUP_PA
)
3855 ext4_mb_release_group_pa(&e4b
, pa
);
3857 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3859 list_del(&pa
->u
.pa_tmp_list
);
3860 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3864 ext4_unlock_group(sb
, group
);
3865 ext4_mb_unload_buddy(&e4b
);
3871 * releases all non-used preallocated blocks for given inode
3873 * It's important to discard preallocations under i_data_sem
3874 * We don't want another block to be served from the prealloc
3875 * space when we are discarding the inode prealloc space.
3877 * FIXME!! Make sure it is valid at all the call sites
3879 void ext4_discard_preallocations(struct inode
*inode
)
3881 struct ext4_inode_info
*ei
= EXT4_I(inode
);
3882 struct super_block
*sb
= inode
->i_sb
;
3883 struct buffer_head
*bitmap_bh
= NULL
;
3884 struct ext4_prealloc_space
*pa
, *tmp
;
3885 ext4_group_t group
= 0;
3886 struct list_head list
;
3887 struct ext4_buddy e4b
;
3890 if (!S_ISREG(inode
->i_mode
)) {
3891 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3895 mb_debug(1, "discard preallocation for inode %lu\n", inode
->i_ino
);
3896 trace_ext4_discard_preallocations(inode
);
3898 INIT_LIST_HEAD(&list
);
3901 /* first, collect all pa's in the inode */
3902 spin_lock(&ei
->i_prealloc_lock
);
3903 while (!list_empty(&ei
->i_prealloc_list
)) {
3904 pa
= list_entry(ei
->i_prealloc_list
.next
,
3905 struct ext4_prealloc_space
, pa_inode_list
);
3906 BUG_ON(pa
->pa_obj_lock
!= &ei
->i_prealloc_lock
);
3907 spin_lock(&pa
->pa_lock
);
3908 if (atomic_read(&pa
->pa_count
)) {
3909 /* this shouldn't happen often - nobody should
3910 * use preallocation while we're discarding it */
3911 spin_unlock(&pa
->pa_lock
);
3912 spin_unlock(&ei
->i_prealloc_lock
);
3913 ext4_msg(sb
, KERN_ERR
,
3914 "uh-oh! used pa while discarding");
3916 schedule_timeout_uninterruptible(HZ
);
3920 if (pa
->pa_deleted
== 0) {
3922 spin_unlock(&pa
->pa_lock
);
3923 list_del_rcu(&pa
->pa_inode_list
);
3924 list_add(&pa
->u
.pa_tmp_list
, &list
);
3928 /* someone is deleting pa right now */
3929 spin_unlock(&pa
->pa_lock
);
3930 spin_unlock(&ei
->i_prealloc_lock
);
3932 /* we have to wait here because pa_deleted
3933 * doesn't mean pa is already unlinked from
3934 * the list. as we might be called from
3935 * ->clear_inode() the inode will get freed
3936 * and concurrent thread which is unlinking
3937 * pa from inode's list may access already
3938 * freed memory, bad-bad-bad */
3940 /* XXX: if this happens too often, we can
3941 * add a flag to force wait only in case
3942 * of ->clear_inode(), but not in case of
3943 * regular truncate */
3944 schedule_timeout_uninterruptible(HZ
);
3947 spin_unlock(&ei
->i_prealloc_lock
);
3949 list_for_each_entry_safe(pa
, tmp
, &list
, u
.pa_tmp_list
) {
3950 BUG_ON(pa
->pa_type
!= MB_INODE_PA
);
3951 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
3953 err
= ext4_mb_load_buddy(sb
, group
, &e4b
);
3955 ext4_error(sb
, "Error loading buddy information for %u",
3960 bitmap_bh
= ext4_read_block_bitmap(sb
, group
);
3961 if (bitmap_bh
== NULL
) {
3962 ext4_error(sb
, "Error reading block bitmap for %u",
3964 ext4_mb_unload_buddy(&e4b
);
3968 ext4_lock_group(sb
, group
);
3969 list_del(&pa
->pa_group_list
);
3970 ext4_mb_release_inode_pa(&e4b
, bitmap_bh
, pa
);
3971 ext4_unlock_group(sb
, group
);
3973 ext4_mb_unload_buddy(&e4b
);
3976 list_del(&pa
->u
.pa_tmp_list
);
3977 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
3981 #ifdef CONFIG_EXT4_DEBUG
3982 static void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
3984 struct super_block
*sb
= ac
->ac_sb
;
3985 ext4_group_t ngroups
, i
;
3987 if (!ext4_mballoc_debug
||
3988 (EXT4_SB(sb
)->s_mount_flags
& EXT4_MF_FS_ABORTED
))
3991 ext4_msg(ac
->ac_sb
, KERN_ERR
, "Can't allocate:"
3992 " Allocation context details:");
3993 ext4_msg(ac
->ac_sb
, KERN_ERR
, "status %d flags %d",
3994 ac
->ac_status
, ac
->ac_flags
);
3995 ext4_msg(ac
->ac_sb
, KERN_ERR
, "orig %lu/%lu/%lu@%lu, "
3996 "goal %lu/%lu/%lu@%lu, "
3997 "best %lu/%lu/%lu@%lu cr %d",
3998 (unsigned long)ac
->ac_o_ex
.fe_group
,
3999 (unsigned long)ac
->ac_o_ex
.fe_start
,
4000 (unsigned long)ac
->ac_o_ex
.fe_len
,
4001 (unsigned long)ac
->ac_o_ex
.fe_logical
,
4002 (unsigned long)ac
->ac_g_ex
.fe_group
,
4003 (unsigned long)ac
->ac_g_ex
.fe_start
,
4004 (unsigned long)ac
->ac_g_ex
.fe_len
,
4005 (unsigned long)ac
->ac_g_ex
.fe_logical
,
4006 (unsigned long)ac
->ac_b_ex
.fe_group
,
4007 (unsigned long)ac
->ac_b_ex
.fe_start
,
4008 (unsigned long)ac
->ac_b_ex
.fe_len
,
4009 (unsigned long)ac
->ac_b_ex
.fe_logical
,
4010 (int)ac
->ac_criteria
);
4011 ext4_msg(ac
->ac_sb
, KERN_ERR
, "%d found", ac
->ac_found
);
4012 ext4_msg(ac
->ac_sb
, KERN_ERR
, "groups: ");
4013 ngroups
= ext4_get_groups_count(sb
);
4014 for (i
= 0; i
< ngroups
; i
++) {
4015 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, i
);
4016 struct ext4_prealloc_space
*pa
;
4017 ext4_grpblk_t start
;
4018 struct list_head
*cur
;
4019 ext4_lock_group(sb
, i
);
4020 list_for_each(cur
, &grp
->bb_prealloc_list
) {
4021 pa
= list_entry(cur
, struct ext4_prealloc_space
,
4023 spin_lock(&pa
->pa_lock
);
4024 ext4_get_group_no_and_offset(sb
, pa
->pa_pstart
,
4026 spin_unlock(&pa
->pa_lock
);
4027 printk(KERN_ERR
"PA:%u:%d:%u \n", i
,
4030 ext4_unlock_group(sb
, i
);
4032 if (grp
->bb_free
== 0)
4034 printk(KERN_ERR
"%u: %d/%d \n",
4035 i
, grp
->bb_free
, grp
->bb_fragments
);
4037 printk(KERN_ERR
"\n");
4040 static inline void ext4_mb_show_ac(struct ext4_allocation_context
*ac
)
4047 * We use locality group preallocation for small size file. The size of the
4048 * file is determined by the current size or the resulting size after
4049 * allocation which ever is larger
4051 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4053 static void ext4_mb_group_or_file(struct ext4_allocation_context
*ac
)
4055 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4056 int bsbits
= ac
->ac_sb
->s_blocksize_bits
;
4059 if (!(ac
->ac_flags
& EXT4_MB_HINT_DATA
))
4062 if (unlikely(ac
->ac_flags
& EXT4_MB_HINT_GOAL_ONLY
))
4065 size
= ac
->ac_o_ex
.fe_logical
+ EXT4_C2B(sbi
, ac
->ac_o_ex
.fe_len
);
4066 isize
= (i_size_read(ac
->ac_inode
) + ac
->ac_sb
->s_blocksize
- 1)
4069 if ((size
== isize
) &&
4070 !ext4_fs_is_busy(sbi
) &&
4071 (atomic_read(&ac
->ac_inode
->i_writecount
) == 0)) {
4072 ac
->ac_flags
|= EXT4_MB_HINT_NOPREALLOC
;
4076 if (sbi
->s_mb_group_prealloc
<= 0) {
4077 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4081 /* don't use group allocation for large files */
4082 size
= max(size
, isize
);
4083 if (size
> sbi
->s_mb_stream_request
) {
4084 ac
->ac_flags
|= EXT4_MB_STREAM_ALLOC
;
4088 BUG_ON(ac
->ac_lg
!= NULL
);
4090 * locality group prealloc space are per cpu. The reason for having
4091 * per cpu locality group is to reduce the contention between block
4092 * request from multiple CPUs.
4094 ac
->ac_lg
= __this_cpu_ptr(sbi
->s_locality_groups
);
4096 /* we're going to use group allocation */
4097 ac
->ac_flags
|= EXT4_MB_HINT_GROUP_ALLOC
;
4099 /* serialize all allocations in the group */
4100 mutex_lock(&ac
->ac_lg
->lg_mutex
);
4103 static noinline_for_stack
int
4104 ext4_mb_initialize_context(struct ext4_allocation_context
*ac
,
4105 struct ext4_allocation_request
*ar
)
4107 struct super_block
*sb
= ar
->inode
->i_sb
;
4108 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4109 struct ext4_super_block
*es
= sbi
->s_es
;
4113 ext4_grpblk_t block
;
4115 /* we can't allocate > group size */
4118 /* just a dirty hack to filter too big requests */
4119 if (len
>= EXT4_CLUSTERS_PER_GROUP(sb
))
4120 len
= EXT4_CLUSTERS_PER_GROUP(sb
);
4122 /* start searching from the goal */
4124 if (goal
< le32_to_cpu(es
->s_first_data_block
) ||
4125 goal
>= ext4_blocks_count(es
))
4126 goal
= le32_to_cpu(es
->s_first_data_block
);
4127 ext4_get_group_no_and_offset(sb
, goal
, &group
, &block
);
4129 /* set up allocation goals */
4130 ac
->ac_b_ex
.fe_logical
= EXT4_LBLK_CMASK(sbi
, ar
->logical
);
4131 ac
->ac_status
= AC_STATUS_CONTINUE
;
4133 ac
->ac_inode
= ar
->inode
;
4134 ac
->ac_o_ex
.fe_logical
= ac
->ac_b_ex
.fe_logical
;
4135 ac
->ac_o_ex
.fe_group
= group
;
4136 ac
->ac_o_ex
.fe_start
= block
;
4137 ac
->ac_o_ex
.fe_len
= len
;
4138 ac
->ac_g_ex
= ac
->ac_o_ex
;
4139 ac
->ac_flags
= ar
->flags
;
4141 /* we have to define context: we'll we work with a file or
4142 * locality group. this is a policy, actually */
4143 ext4_mb_group_or_file(ac
);
4145 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4146 "left: %u/%u, right %u/%u to %swritable\n",
4147 (unsigned) ar
->len
, (unsigned) ar
->logical
,
4148 (unsigned) ar
->goal
, ac
->ac_flags
, ac
->ac_2order
,
4149 (unsigned) ar
->lleft
, (unsigned) ar
->pleft
,
4150 (unsigned) ar
->lright
, (unsigned) ar
->pright
,
4151 atomic_read(&ar
->inode
->i_writecount
) ? "" : "non-");
4156 static noinline_for_stack
void
4157 ext4_mb_discard_lg_preallocations(struct super_block
*sb
,
4158 struct ext4_locality_group
*lg
,
4159 int order
, int total_entries
)
4161 ext4_group_t group
= 0;
4162 struct ext4_buddy e4b
;
4163 struct list_head discard_list
;
4164 struct ext4_prealloc_space
*pa
, *tmp
;
4166 mb_debug(1, "discard locality group preallocation\n");
4168 INIT_LIST_HEAD(&discard_list
);
4170 spin_lock(&lg
->lg_prealloc_lock
);
4171 list_for_each_entry_rcu(pa
, &lg
->lg_prealloc_list
[order
],
4173 spin_lock(&pa
->pa_lock
);
4174 if (atomic_read(&pa
->pa_count
)) {
4176 * This is the pa that we just used
4177 * for block allocation. So don't
4180 spin_unlock(&pa
->pa_lock
);
4183 if (pa
->pa_deleted
) {
4184 spin_unlock(&pa
->pa_lock
);
4187 /* only lg prealloc space */
4188 BUG_ON(pa
->pa_type
!= MB_GROUP_PA
);
4190 /* seems this one can be freed ... */
4192 spin_unlock(&pa
->pa_lock
);
4194 list_del_rcu(&pa
->pa_inode_list
);
4195 list_add(&pa
->u
.pa_tmp_list
, &discard_list
);
4198 if (total_entries
<= 5) {
4200 * we want to keep only 5 entries
4201 * allowing it to grow to 8. This
4202 * mak sure we don't call discard
4203 * soon for this list.
4208 spin_unlock(&lg
->lg_prealloc_lock
);
4210 list_for_each_entry_safe(pa
, tmp
, &discard_list
, u
.pa_tmp_list
) {
4212 group
= ext4_get_group_number(sb
, pa
->pa_pstart
);
4213 if (ext4_mb_load_buddy(sb
, group
, &e4b
)) {
4214 ext4_error(sb
, "Error loading buddy information for %u",
4218 ext4_lock_group(sb
, group
);
4219 list_del(&pa
->pa_group_list
);
4220 ext4_mb_release_group_pa(&e4b
, pa
);
4221 ext4_unlock_group(sb
, group
);
4223 ext4_mb_unload_buddy(&e4b
);
4224 list_del(&pa
->u
.pa_tmp_list
);
4225 call_rcu(&(pa
)->u
.pa_rcu
, ext4_mb_pa_callback
);
4230 * We have incremented pa_count. So it cannot be freed at this
4231 * point. Also we hold lg_mutex. So no parallel allocation is
4232 * possible from this lg. That means pa_free cannot be updated.
4234 * A parallel ext4_mb_discard_group_preallocations is possible.
4235 * which can cause the lg_prealloc_list to be updated.
4238 static void ext4_mb_add_n_trim(struct ext4_allocation_context
*ac
)
4240 int order
, added
= 0, lg_prealloc_count
= 1;
4241 struct super_block
*sb
= ac
->ac_sb
;
4242 struct ext4_locality_group
*lg
= ac
->ac_lg
;
4243 struct ext4_prealloc_space
*tmp_pa
, *pa
= ac
->ac_pa
;
4245 order
= fls(pa
->pa_free
) - 1;
4246 if (order
> PREALLOC_TB_SIZE
- 1)
4247 /* The max size of hash table is PREALLOC_TB_SIZE */
4248 order
= PREALLOC_TB_SIZE
- 1;
4249 /* Add the prealloc space to lg */
4250 spin_lock(&lg
->lg_prealloc_lock
);
4251 list_for_each_entry_rcu(tmp_pa
, &lg
->lg_prealloc_list
[order
],
4253 spin_lock(&tmp_pa
->pa_lock
);
4254 if (tmp_pa
->pa_deleted
) {
4255 spin_unlock(&tmp_pa
->pa_lock
);
4258 if (!added
&& pa
->pa_free
< tmp_pa
->pa_free
) {
4259 /* Add to the tail of the previous entry */
4260 list_add_tail_rcu(&pa
->pa_inode_list
,
4261 &tmp_pa
->pa_inode_list
);
4264 * we want to count the total
4265 * number of entries in the list
4268 spin_unlock(&tmp_pa
->pa_lock
);
4269 lg_prealloc_count
++;
4272 list_add_tail_rcu(&pa
->pa_inode_list
,
4273 &lg
->lg_prealloc_list
[order
]);
4274 spin_unlock(&lg
->lg_prealloc_lock
);
4276 /* Now trim the list to be not more than 8 elements */
4277 if (lg_prealloc_count
> 8) {
4278 ext4_mb_discard_lg_preallocations(sb
, lg
,
4279 order
, lg_prealloc_count
);
4286 * release all resource we used in allocation
4288 static int ext4_mb_release_context(struct ext4_allocation_context
*ac
)
4290 struct ext4_sb_info
*sbi
= EXT4_SB(ac
->ac_sb
);
4291 struct ext4_prealloc_space
*pa
= ac
->ac_pa
;
4293 if (pa
->pa_type
== MB_GROUP_PA
) {
4294 /* see comment in ext4_mb_use_group_pa() */
4295 spin_lock(&pa
->pa_lock
);
4296 pa
->pa_pstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4297 pa
->pa_lstart
+= EXT4_C2B(sbi
, ac
->ac_b_ex
.fe_len
);
4298 pa
->pa_free
-= ac
->ac_b_ex
.fe_len
;
4299 pa
->pa_len
-= ac
->ac_b_ex
.fe_len
;
4300 spin_unlock(&pa
->pa_lock
);
4305 * We want to add the pa to the right bucket.
4306 * Remove it from the list and while adding
4307 * make sure the list to which we are adding
4310 if ((pa
->pa_type
== MB_GROUP_PA
) && likely(pa
->pa_free
)) {
4311 spin_lock(pa
->pa_obj_lock
);
4312 list_del_rcu(&pa
->pa_inode_list
);
4313 spin_unlock(pa
->pa_obj_lock
);
4314 ext4_mb_add_n_trim(ac
);
4316 ext4_mb_put_pa(ac
, ac
->ac_sb
, pa
);
4318 if (ac
->ac_bitmap_page
)
4319 page_cache_release(ac
->ac_bitmap_page
);
4320 if (ac
->ac_buddy_page
)
4321 page_cache_release(ac
->ac_buddy_page
);
4322 if (ac
->ac_flags
& EXT4_MB_HINT_GROUP_ALLOC
)
4323 mutex_unlock(&ac
->ac_lg
->lg_mutex
);
4324 ext4_mb_collect_stats(ac
);
4328 static int ext4_mb_discard_preallocations(struct super_block
*sb
, int needed
)
4330 ext4_group_t i
, ngroups
= ext4_get_groups_count(sb
);
4334 trace_ext4_mb_discard_preallocations(sb
, needed
);
4335 for (i
= 0; i
< ngroups
&& needed
> 0; i
++) {
4336 ret
= ext4_mb_discard_group_preallocations(sb
, i
, needed
);
4345 * Main entry point into mballoc to allocate blocks
4346 * it tries to use preallocation first, then falls back
4347 * to usual allocation
4349 ext4_fsblk_t
ext4_mb_new_blocks(handle_t
*handle
,
4350 struct ext4_allocation_request
*ar
, int *errp
)
4353 struct ext4_allocation_context
*ac
= NULL
;
4354 struct ext4_sb_info
*sbi
;
4355 struct super_block
*sb
;
4356 ext4_fsblk_t block
= 0;
4357 unsigned int inquota
= 0;
4358 unsigned int reserv_clstrs
= 0;
4361 sb
= ar
->inode
->i_sb
;
4364 trace_ext4_request_blocks(ar
);
4366 /* Allow to use superuser reservation for quota file */
4367 if (IS_NOQUOTA(ar
->inode
))
4368 ar
->flags
|= EXT4_MB_USE_ROOT_BLOCKS
;
4371 * For delayed allocation, we could skip the ENOSPC and
4372 * EDQUOT check, as blocks and quotas have been already
4373 * reserved when data being copied into pagecache.
4375 if (ext4_test_inode_state(ar
->inode
, EXT4_STATE_DELALLOC_RESERVED
))
4376 ar
->flags
|= EXT4_MB_DELALLOC_RESERVED
;
4378 /* Without delayed allocation we need to verify
4379 * there is enough free blocks to do block allocation
4380 * and verify allocation doesn't exceed the quota limits.
4383 ext4_claim_free_clusters(sbi
, ar
->len
, ar
->flags
)) {
4385 /* let others to free the space */
4387 ar
->len
= ar
->len
>> 1;
4393 reserv_clstrs
= ar
->len
;
4394 if (ar
->flags
& EXT4_MB_USE_ROOT_BLOCKS
) {
4395 dquot_alloc_block_nofail(ar
->inode
,
4396 EXT4_C2B(sbi
, ar
->len
));
4399 dquot_alloc_block(ar
->inode
,
4400 EXT4_C2B(sbi
, ar
->len
))) {
4402 ar
->flags
|= EXT4_MB_HINT_NOPREALLOC
;
4413 ac
= kmem_cache_zalloc(ext4_ac_cachep
, GFP_NOFS
);
4420 *errp
= ext4_mb_initialize_context(ac
, ar
);
4426 ac
->ac_op
= EXT4_MB_HISTORY_PREALLOC
;
4427 if (!ext4_mb_use_preallocated(ac
)) {
4428 ac
->ac_op
= EXT4_MB_HISTORY_ALLOC
;
4429 ext4_mb_normalize_request(ac
, ar
);
4431 /* allocate space in core */
4432 *errp
= ext4_mb_regular_allocator(ac
);
4434 goto discard_and_exit
;
4436 /* as we've just preallocated more space than
4437 * user requested originally, we store allocated
4438 * space in a special descriptor */
4439 if (ac
->ac_status
== AC_STATUS_FOUND
&&
4440 ac
->ac_o_ex
.fe_len
< ac
->ac_b_ex
.fe_len
)
4441 *errp
= ext4_mb_new_preallocation(ac
);
4444 ext4_discard_allocated_blocks(ac
);
4448 if (likely(ac
->ac_status
== AC_STATUS_FOUND
)) {
4449 *errp
= ext4_mb_mark_diskspace_used(ac
, handle
, reserv_clstrs
);
4450 if (*errp
== -EAGAIN
) {
4452 * drop the reference that we took
4453 * in ext4_mb_use_best_found
4455 ext4_mb_release_context(ac
);
4456 ac
->ac_b_ex
.fe_group
= 0;
4457 ac
->ac_b_ex
.fe_start
= 0;
4458 ac
->ac_b_ex
.fe_len
= 0;
4459 ac
->ac_status
= AC_STATUS_CONTINUE
;
4462 ext4_discard_allocated_blocks(ac
);
4465 block
= ext4_grp_offs_to_block(sb
, &ac
->ac_b_ex
);
4466 ar
->len
= ac
->ac_b_ex
.fe_len
;
4469 freed
= ext4_mb_discard_preallocations(sb
, ac
->ac_o_ex
.fe_len
);
4477 ac
->ac_b_ex
.fe_len
= 0;
4479 ext4_mb_show_ac(ac
);
4481 ext4_mb_release_context(ac
);
4484 kmem_cache_free(ext4_ac_cachep
, ac
);
4485 if (inquota
&& ar
->len
< inquota
)
4486 dquot_free_block(ar
->inode
, EXT4_C2B(sbi
, inquota
- ar
->len
));
4488 if (!ext4_test_inode_state(ar
->inode
,
4489 EXT4_STATE_DELALLOC_RESERVED
))
4490 /* release all the reserved blocks if non delalloc */
4491 percpu_counter_sub(&sbi
->s_dirtyclusters_counter
,
4495 trace_ext4_allocate_blocks(ar
, (unsigned long long)block
);
4501 * We can merge two free data extents only if the physical blocks
4502 * are contiguous, AND the extents were freed by the same transaction,
4503 * AND the blocks are associated with the same group.
4505 static int can_merge(struct ext4_free_data
*entry1
,
4506 struct ext4_free_data
*entry2
)
4508 if ((entry1
->efd_tid
== entry2
->efd_tid
) &&
4509 (entry1
->efd_group
== entry2
->efd_group
) &&
4510 ((entry1
->efd_start_cluster
+ entry1
->efd_count
) == entry2
->efd_start_cluster
))
4515 static noinline_for_stack
int
4516 ext4_mb_free_metadata(handle_t
*handle
, struct ext4_buddy
*e4b
,
4517 struct ext4_free_data
*new_entry
)
4519 ext4_group_t group
= e4b
->bd_group
;
4520 ext4_grpblk_t cluster
;
4521 struct ext4_free_data
*entry
;
4522 struct ext4_group_info
*db
= e4b
->bd_info
;
4523 struct super_block
*sb
= e4b
->bd_sb
;
4524 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4525 struct rb_node
**n
= &db
->bb_free_root
.rb_node
, *node
;
4526 struct rb_node
*parent
= NULL
, *new_node
;
4528 BUG_ON(!ext4_handle_valid(handle
));
4529 BUG_ON(e4b
->bd_bitmap_page
== NULL
);
4530 BUG_ON(e4b
->bd_buddy_page
== NULL
);
4532 new_node
= &new_entry
->efd_node
;
4533 cluster
= new_entry
->efd_start_cluster
;
4536 /* first free block exent. We need to
4537 protect buddy cache from being freed,
4538 * otherwise we'll refresh it from
4539 * on-disk bitmap and lose not-yet-available
4541 page_cache_get(e4b
->bd_buddy_page
);
4542 page_cache_get(e4b
->bd_bitmap_page
);
4546 entry
= rb_entry(parent
, struct ext4_free_data
, efd_node
);
4547 if (cluster
< entry
->efd_start_cluster
)
4549 else if (cluster
>= (entry
->efd_start_cluster
+ entry
->efd_count
))
4550 n
= &(*n
)->rb_right
;
4552 ext4_grp_locked_error(sb
, group
, 0,
4553 ext4_group_first_block_no(sb
, group
) +
4554 EXT4_C2B(sbi
, cluster
),
4555 "Block already on to-be-freed list");
4560 rb_link_node(new_node
, parent
, n
);
4561 rb_insert_color(new_node
, &db
->bb_free_root
);
4563 /* Now try to see the extent can be merged to left and right */
4564 node
= rb_prev(new_node
);
4566 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4567 if (can_merge(entry
, new_entry
) &&
4568 ext4_journal_callback_try_del(handle
, &entry
->efd_jce
)) {
4569 new_entry
->efd_start_cluster
= entry
->efd_start_cluster
;
4570 new_entry
->efd_count
+= entry
->efd_count
;
4571 rb_erase(node
, &(db
->bb_free_root
));
4572 kmem_cache_free(ext4_free_data_cachep
, entry
);
4576 node
= rb_next(new_node
);
4578 entry
= rb_entry(node
, struct ext4_free_data
, efd_node
);
4579 if (can_merge(new_entry
, entry
) &&
4580 ext4_journal_callback_try_del(handle
, &entry
->efd_jce
)) {
4581 new_entry
->efd_count
+= entry
->efd_count
;
4582 rb_erase(node
, &(db
->bb_free_root
));
4583 kmem_cache_free(ext4_free_data_cachep
, entry
);
4586 /* Add the extent to transaction's private list */
4587 ext4_journal_callback_add(handle
, ext4_free_data_callback
,
4588 &new_entry
->efd_jce
);
4593 * ext4_free_blocks() -- Free given blocks and update quota
4594 * @handle: handle for this transaction
4596 * @block: start physical block to free
4597 * @count: number of blocks to count
4598 * @flags: flags used by ext4_free_blocks
4600 void ext4_free_blocks(handle_t
*handle
, struct inode
*inode
,
4601 struct buffer_head
*bh
, ext4_fsblk_t block
,
4602 unsigned long count
, int flags
)
4604 struct buffer_head
*bitmap_bh
= NULL
;
4605 struct super_block
*sb
= inode
->i_sb
;
4606 struct ext4_group_desc
*gdp
;
4607 unsigned int overflow
;
4609 struct buffer_head
*gd_bh
;
4610 ext4_group_t block_group
;
4611 struct ext4_sb_info
*sbi
;
4612 struct ext4_inode_info
*ei
= EXT4_I(inode
);
4613 struct ext4_buddy e4b
;
4614 unsigned int count_clusters
;
4621 BUG_ON(block
!= bh
->b_blocknr
);
4623 block
= bh
->b_blocknr
;
4627 if (!(flags
& EXT4_FREE_BLOCKS_VALIDATED
) &&
4628 !ext4_data_block_valid(sbi
, block
, count
)) {
4629 ext4_error(sb
, "Freeing blocks not in datazone - "
4630 "block = %llu, count = %lu", block
, count
);
4634 ext4_debug("freeing block %llu\n", block
);
4635 trace_ext4_free_blocks(inode
, block
, count
, flags
);
4637 if (flags
& EXT4_FREE_BLOCKS_FORGET
) {
4638 struct buffer_head
*tbh
= bh
;
4641 BUG_ON(bh
&& (count
> 1));
4643 for (i
= 0; i
< count
; i
++) {
4646 tbh
= sb_find_get_block(inode
->i_sb
,
4650 ext4_forget(handle
, flags
& EXT4_FREE_BLOCKS_METADATA
,
4651 inode
, tbh
, block
+ i
);
4656 * We need to make sure we don't reuse the freed block until
4657 * after the transaction is committed, which we can do by
4658 * treating the block as metadata, below. We make an
4659 * exception if the inode is to be written in writeback mode
4660 * since writeback mode has weak data consistency guarantees.
4662 if (!ext4_should_writeback_data(inode
))
4663 flags
|= EXT4_FREE_BLOCKS_METADATA
;
4666 * If the extent to be freed does not begin on a cluster
4667 * boundary, we need to deal with partial clusters at the
4668 * beginning and end of the extent. Normally we will free
4669 * blocks at the beginning or the end unless we are explicitly
4670 * requested to avoid doing so.
4672 overflow
= EXT4_PBLK_COFF(sbi
, block
);
4674 if (flags
& EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER
) {
4675 overflow
= sbi
->s_cluster_ratio
- overflow
;
4677 if (count
> overflow
)
4686 overflow
= EXT4_LBLK_COFF(sbi
, count
);
4688 if (flags
& EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER
) {
4689 if (count
> overflow
)
4694 count
+= sbi
->s_cluster_ratio
- overflow
;
4699 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4701 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
4702 ext4_get_group_info(sb
, block_group
))))
4706 * Check to see if we are freeing blocks across a group
4709 if (EXT4_C2B(sbi
, bit
) + count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4710 overflow
= EXT4_C2B(sbi
, bit
) + count
-
4711 EXT4_BLOCKS_PER_GROUP(sb
);
4714 count_clusters
= EXT4_NUM_B2C(sbi
, count
);
4715 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4720 gdp
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4726 if (in_range(ext4_block_bitmap(sb
, gdp
), block
, count
) ||
4727 in_range(ext4_inode_bitmap(sb
, gdp
), block
, count
) ||
4728 in_range(block
, ext4_inode_table(sb
, gdp
),
4729 EXT4_SB(sb
)->s_itb_per_group
) ||
4730 in_range(block
+ count
- 1, ext4_inode_table(sb
, gdp
),
4731 EXT4_SB(sb
)->s_itb_per_group
)) {
4733 ext4_error(sb
, "Freeing blocks in system zone - "
4734 "Block = %llu, count = %lu", block
, count
);
4735 /* err = 0. ext4_std_error should be a no op */
4739 BUFFER_TRACE(bitmap_bh
, "getting write access");
4740 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4745 * We are about to modify some metadata. Call the journal APIs
4746 * to unshare ->b_data if a currently-committing transaction is
4749 BUFFER_TRACE(gd_bh
, "get_write_access");
4750 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4753 #ifdef AGGRESSIVE_CHECK
4756 for (i
= 0; i
< count_clusters
; i
++)
4757 BUG_ON(!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
));
4760 trace_ext4_mballoc_free(sb
, inode
, block_group
, bit
, count_clusters
);
4762 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4766 if ((flags
& EXT4_FREE_BLOCKS_METADATA
) && ext4_handle_valid(handle
)) {
4767 struct ext4_free_data
*new_entry
;
4769 * blocks being freed are metadata. these blocks shouldn't
4770 * be used until this transaction is committed
4773 new_entry
= kmem_cache_alloc(ext4_free_data_cachep
, GFP_NOFS
);
4776 * We use a retry loop because
4777 * ext4_free_blocks() is not allowed to fail.
4780 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
4783 new_entry
->efd_start_cluster
= bit
;
4784 new_entry
->efd_group
= block_group
;
4785 new_entry
->efd_count
= count_clusters
;
4786 new_entry
->efd_tid
= handle
->h_transaction
->t_tid
;
4788 ext4_lock_group(sb
, block_group
);
4789 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4790 ext4_mb_free_metadata(handle
, &e4b
, new_entry
);
4792 /* need to update group_info->bb_free and bitmap
4793 * with group lock held. generate_buddy look at
4794 * them with group lock_held
4796 if (test_opt(sb
, DISCARD
)) {
4797 err
= ext4_issue_discard(sb
, block_group
, bit
, count
);
4798 if (err
&& err
!= -EOPNOTSUPP
)
4799 ext4_msg(sb
, KERN_WARNING
, "discard request in"
4800 " group:%d block:%d count:%lu failed"
4801 " with %d", block_group
, bit
, count
,
4804 EXT4_MB_GRP_CLEAR_TRIMMED(e4b
.bd_info
);
4806 ext4_lock_group(sb
, block_group
);
4807 mb_clear_bits(bitmap_bh
->b_data
, bit
, count_clusters
);
4808 mb_free_blocks(inode
, &e4b
, bit
, count_clusters
);
4811 ret
= ext4_free_group_clusters(sb
, gdp
) + count_clusters
;
4812 ext4_free_group_clusters_set(sb
, gdp
, ret
);
4813 ext4_block_bitmap_csum_set(sb
, block_group
, gdp
, bitmap_bh
);
4814 ext4_group_desc_csum_set(sb
, block_group
, gdp
);
4815 ext4_unlock_group(sb
, block_group
);
4817 if (sbi
->s_log_groups_per_flex
) {
4818 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4819 atomic64_add(count_clusters
,
4820 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4823 if (flags
& EXT4_FREE_BLOCKS_RESERVE
&& ei
->i_reserved_data_blocks
) {
4824 percpu_counter_add(&sbi
->s_dirtyclusters_counter
,
4826 spin_lock(&ei
->i_block_reservation_lock
);
4827 if (flags
& EXT4_FREE_BLOCKS_METADATA
)
4828 ei
->i_reserved_meta_blocks
+= count_clusters
;
4830 ei
->i_reserved_data_blocks
+= count_clusters
;
4831 spin_unlock(&ei
->i_block_reservation_lock
);
4832 if (!(flags
& EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
))
4833 dquot_reclaim_block(inode
,
4834 EXT4_C2B(sbi
, count_clusters
));
4835 } else if (!(flags
& EXT4_FREE_BLOCKS_NO_QUOT_UPDATE
))
4836 dquot_free_block(inode
, EXT4_C2B(sbi
, count_clusters
));
4837 percpu_counter_add(&sbi
->s_freeclusters_counter
, count_clusters
);
4839 ext4_mb_unload_buddy(&e4b
);
4841 /* We dirtied the bitmap block */
4842 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4843 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4845 /* And the group descriptor block */
4846 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4847 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4851 if (overflow
&& !err
) {
4859 ext4_std_error(sb
, err
);
4864 * ext4_group_add_blocks() -- Add given blocks to an existing group
4865 * @handle: handle to this transaction
4867 * @block: start physical block to add to the block group
4868 * @count: number of blocks to free
4870 * This marks the blocks as free in the bitmap and buddy.
4872 int ext4_group_add_blocks(handle_t
*handle
, struct super_block
*sb
,
4873 ext4_fsblk_t block
, unsigned long count
)
4875 struct buffer_head
*bitmap_bh
= NULL
;
4876 struct buffer_head
*gd_bh
;
4877 ext4_group_t block_group
;
4880 struct ext4_group_desc
*desc
;
4881 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
4882 struct ext4_buddy e4b
;
4883 int err
= 0, ret
, blk_free_count
;
4884 ext4_grpblk_t blocks_freed
;
4886 ext4_debug("Adding block(s) %llu-%llu\n", block
, block
+ count
- 1);
4891 ext4_get_group_no_and_offset(sb
, block
, &block_group
, &bit
);
4893 * Check to see if we are freeing blocks across a group
4896 if (bit
+ count
> EXT4_BLOCKS_PER_GROUP(sb
)) {
4897 ext4_warning(sb
, "too much blocks added to group %u\n",
4903 bitmap_bh
= ext4_read_block_bitmap(sb
, block_group
);
4909 desc
= ext4_get_group_desc(sb
, block_group
, &gd_bh
);
4915 if (in_range(ext4_block_bitmap(sb
, desc
), block
, count
) ||
4916 in_range(ext4_inode_bitmap(sb
, desc
), block
, count
) ||
4917 in_range(block
, ext4_inode_table(sb
, desc
), sbi
->s_itb_per_group
) ||
4918 in_range(block
+ count
- 1, ext4_inode_table(sb
, desc
),
4919 sbi
->s_itb_per_group
)) {
4920 ext4_error(sb
, "Adding blocks in system zones - "
4921 "Block = %llu, count = %lu",
4927 BUFFER_TRACE(bitmap_bh
, "getting write access");
4928 err
= ext4_journal_get_write_access(handle
, bitmap_bh
);
4933 * We are about to modify some metadata. Call the journal APIs
4934 * to unshare ->b_data if a currently-committing transaction is
4937 BUFFER_TRACE(gd_bh
, "get_write_access");
4938 err
= ext4_journal_get_write_access(handle
, gd_bh
);
4942 for (i
= 0, blocks_freed
= 0; i
< count
; i
++) {
4943 BUFFER_TRACE(bitmap_bh
, "clear bit");
4944 if (!mb_test_bit(bit
+ i
, bitmap_bh
->b_data
)) {
4945 ext4_error(sb
, "bit already cleared for block %llu",
4946 (ext4_fsblk_t
)(block
+ i
));
4947 BUFFER_TRACE(bitmap_bh
, "bit already cleared");
4953 err
= ext4_mb_load_buddy(sb
, block_group
, &e4b
);
4958 * need to update group_info->bb_free and bitmap
4959 * with group lock held. generate_buddy look at
4960 * them with group lock_held
4962 ext4_lock_group(sb
, block_group
);
4963 mb_clear_bits(bitmap_bh
->b_data
, bit
, count
);
4964 mb_free_blocks(NULL
, &e4b
, bit
, count
);
4965 blk_free_count
= blocks_freed
+ ext4_free_group_clusters(sb
, desc
);
4966 ext4_free_group_clusters_set(sb
, desc
, blk_free_count
);
4967 ext4_block_bitmap_csum_set(sb
, block_group
, desc
, bitmap_bh
);
4968 ext4_group_desc_csum_set(sb
, block_group
, desc
);
4969 ext4_unlock_group(sb
, block_group
);
4970 percpu_counter_add(&sbi
->s_freeclusters_counter
,
4971 EXT4_NUM_B2C(sbi
, blocks_freed
));
4973 if (sbi
->s_log_groups_per_flex
) {
4974 ext4_group_t flex_group
= ext4_flex_group(sbi
, block_group
);
4975 atomic64_add(EXT4_NUM_B2C(sbi
, blocks_freed
),
4976 &sbi
->s_flex_groups
[flex_group
].free_clusters
);
4979 ext4_mb_unload_buddy(&e4b
);
4981 /* We dirtied the bitmap block */
4982 BUFFER_TRACE(bitmap_bh
, "dirtied bitmap block");
4983 err
= ext4_handle_dirty_metadata(handle
, NULL
, bitmap_bh
);
4985 /* And the group descriptor block */
4986 BUFFER_TRACE(gd_bh
, "dirtied group descriptor block");
4987 ret
= ext4_handle_dirty_metadata(handle
, NULL
, gd_bh
);
4993 ext4_std_error(sb
, err
);
4998 * ext4_trim_extent -- function to TRIM one single free extent in the group
4999 * @sb: super block for the file system
5000 * @start: starting block of the free extent in the alloc. group
5001 * @count: number of blocks to TRIM
5002 * @group: alloc. group we are working with
5003 * @e4b: ext4 buddy for the group
5005 * Trim "count" blocks starting at "start" in the "group". To assure that no
5006 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5007 * be called with under the group lock.
5009 static int ext4_trim_extent(struct super_block
*sb
, int start
, int count
,
5010 ext4_group_t group
, struct ext4_buddy
*e4b
)
5012 struct ext4_free_extent ex
;
5015 trace_ext4_trim_extent(sb
, group
, start
, count
);
5017 assert_spin_locked(ext4_group_lock_ptr(sb
, group
));
5019 ex
.fe_start
= start
;
5020 ex
.fe_group
= group
;
5024 * Mark blocks used, so no one can reuse them while
5027 mb_mark_used(e4b
, &ex
);
5028 ext4_unlock_group(sb
, group
);
5029 ret
= ext4_issue_discard(sb
, group
, start
, count
);
5030 ext4_lock_group(sb
, group
);
5031 mb_free_blocks(NULL
, e4b
, start
, ex
.fe_len
);
5036 * ext4_trim_all_free -- function to trim all free space in alloc. group
5037 * @sb: super block for file system
5038 * @group: group to be trimmed
5039 * @start: first group block to examine
5040 * @max: last group block to examine
5041 * @minblocks: minimum extent block count
5043 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5044 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5048 * ext4_trim_all_free walks through group's block bitmap searching for free
5049 * extents. When the free extent is found, mark it as used in group buddy
5050 * bitmap. Then issue a TRIM command on this extent and free the extent in
5051 * the group buddy bitmap. This is done until whole group is scanned.
5053 static ext4_grpblk_t
5054 ext4_trim_all_free(struct super_block
*sb
, ext4_group_t group
,
5055 ext4_grpblk_t start
, ext4_grpblk_t max
,
5056 ext4_grpblk_t minblocks
)
5059 ext4_grpblk_t next
, count
= 0, free_count
= 0;
5060 struct ext4_buddy e4b
;
5063 trace_ext4_trim_all_free(sb
, group
, start
, max
);
5065 ret
= ext4_mb_load_buddy(sb
, group
, &e4b
);
5067 ext4_error(sb
, "Error in loading buddy "
5068 "information for %u", group
);
5071 bitmap
= e4b
.bd_bitmap
;
5073 ext4_lock_group(sb
, group
);
5074 if (EXT4_MB_GRP_WAS_TRIMMED(e4b
.bd_info
) &&
5075 minblocks
>= atomic_read(&EXT4_SB(sb
)->s_last_trim_minblks
))
5078 start
= (e4b
.bd_info
->bb_first_free
> start
) ?
5079 e4b
.bd_info
->bb_first_free
: start
;
5081 while (start
<= max
) {
5082 start
= mb_find_next_zero_bit(bitmap
, max
+ 1, start
);
5085 next
= mb_find_next_bit(bitmap
, max
+ 1, start
);
5087 if ((next
- start
) >= minblocks
) {
5088 ret
= ext4_trim_extent(sb
, start
,
5089 next
- start
, group
, &e4b
);
5090 if (ret
&& ret
!= -EOPNOTSUPP
)
5093 count
+= next
- start
;
5095 free_count
+= next
- start
;
5098 if (fatal_signal_pending(current
)) {
5099 count
= -ERESTARTSYS
;
5103 if (need_resched()) {
5104 ext4_unlock_group(sb
, group
);
5106 ext4_lock_group(sb
, group
);
5109 if ((e4b
.bd_info
->bb_free
- free_count
) < minblocks
)
5115 EXT4_MB_GRP_SET_TRIMMED(e4b
.bd_info
);
5118 ext4_unlock_group(sb
, group
);
5119 ext4_mb_unload_buddy(&e4b
);
5121 ext4_debug("trimmed %d blocks in the group %d\n",
5128 * ext4_trim_fs() -- trim ioctl handle function
5129 * @sb: superblock for filesystem
5130 * @range: fstrim_range structure
5132 * start: First Byte to trim
5133 * len: number of Bytes to trim from start
5134 * minlen: minimum extent length in Bytes
5135 * ext4_trim_fs goes through all allocation groups containing Bytes from
5136 * start to start+len. For each such a group ext4_trim_all_free function
5137 * is invoked to trim all free space.
5139 int ext4_trim_fs(struct super_block
*sb
, struct fstrim_range
*range
)
5141 struct ext4_group_info
*grp
;
5142 ext4_group_t group
, first_group
, last_group
;
5143 ext4_grpblk_t cnt
= 0, first_cluster
, last_cluster
;
5144 uint64_t start
, end
, minlen
, trimmed
= 0;
5145 ext4_fsblk_t first_data_blk
=
5146 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
);
5147 ext4_fsblk_t max_blks
= ext4_blocks_count(EXT4_SB(sb
)->s_es
);
5150 start
= range
->start
>> sb
->s_blocksize_bits
;
5151 end
= start
+ (range
->len
>> sb
->s_blocksize_bits
) - 1;
5152 minlen
= EXT4_NUM_B2C(EXT4_SB(sb
),
5153 range
->minlen
>> sb
->s_blocksize_bits
);
5155 if (minlen
> EXT4_CLUSTERS_PER_GROUP(sb
) ||
5156 start
>= max_blks
||
5157 range
->len
< sb
->s_blocksize
)
5159 if (end
>= max_blks
)
5161 if (end
<= first_data_blk
)
5163 if (start
< first_data_blk
)
5164 start
= first_data_blk
;
5166 /* Determine first and last group to examine based on start and end */
5167 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) start
,
5168 &first_group
, &first_cluster
);
5169 ext4_get_group_no_and_offset(sb
, (ext4_fsblk_t
) end
,
5170 &last_group
, &last_cluster
);
5172 /* end now represents the last cluster to discard in this group */
5173 end
= EXT4_CLUSTERS_PER_GROUP(sb
) - 1;
5175 for (group
= first_group
; group
<= last_group
; group
++) {
5176 grp
= ext4_get_group_info(sb
, group
);
5177 /* We only do this if the grp has never been initialized */
5178 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp
))) {
5179 ret
= ext4_mb_init_group(sb
, group
);
5185 * For all the groups except the last one, last cluster will
5186 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5187 * change it for the last group, note that last_cluster is
5188 * already computed earlier by ext4_get_group_no_and_offset()
5190 if (group
== last_group
)
5193 if (grp
->bb_free
>= minlen
) {
5194 cnt
= ext4_trim_all_free(sb
, group
, first_cluster
,
5204 * For every group except the first one, we are sure
5205 * that the first cluster to discard will be cluster #0.
5211 atomic_set(&EXT4_SB(sb
)->s_last_trim_minblks
, minlen
);
5214 range
->len
= EXT4_C2B(EXT4_SB(sb
), trimmed
) << sb
->s_blocksize_bits
;