1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
4 * Written by Alex Tomas <alex@clusterfs.com>
9 * mballoc.c contains the multiblocks allocation routines
12 #include "ext4_jbd2.h"
14 #include <linux/log2.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/nospec.h>
18 #include <linux/backing-dev.h>
19 #include <trace/events/ext4.h>
23 * - test ext4_ext_search_left() and ext4_ext_search_right()
24 * - search for metadata in few groups
27 * - normalization should take into account whether file is still open
28 * - discard preallocations if no free space left (policy?)
29 * - don't normalize tails
31 * - reservation for superuser
34 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
35 * - track min/max extents in each group for better group selection
36 * - mb_mark_used() may allocate chunk right after splitting buddy
37 * - tree of groups sorted by number of free blocks
42 * The allocation request involve request for multiple number of blocks
43 * near to the goal(block) value specified.
45 * During initialization phase of the allocator we decide to use the
46 * group preallocation or inode preallocation depending on the size of
47 * the file. The size of the file could be the resulting file size we
48 * would have after allocation, or the current file size, which ever
49 * is larger. If the size is less than sbi->s_mb_stream_request we
50 * select to use the group preallocation. The default value of
51 * s_mb_stream_request is 16 blocks. This can also be tuned via
52 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
53 * terms of number of blocks.
55 * The main motivation for having small file use group preallocation is to
56 * ensure that we have small files closer together on the disk.
58 * First stage the allocator looks at the inode prealloc list,
59 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
60 * spaces for this particular inode. The inode prealloc space is
63 * pa_lstart -> the logical start block for this prealloc space
64 * pa_pstart -> the physical start block for this prealloc space
65 * pa_len -> length for this prealloc space (in clusters)
66 * pa_free -> free space available in this prealloc space (in clusters)
68 * The inode preallocation space is used looking at the _logical_ start
69 * block. If only the logical file block falls within the range of prealloc
70 * space we will consume the particular prealloc space. This makes sure that
71 * we have contiguous physical blocks representing the file blocks
73 * The important thing to be noted in case of inode prealloc space is that
74 * we don't modify the values associated to inode prealloc space except
77 * If we are not able to find blocks in the inode prealloc space and if we
78 * have the group allocation flag set then we look at the locality group
79 * prealloc space. These are per CPU prealloc list represented as
81 * ext4_sb_info.s_locality_groups[smp_processor_id()]
83 * The reason for having a per cpu locality group is to reduce the contention
84 * between CPUs. It is possible to get scheduled at this point.
86 * The locality group prealloc space is used looking at whether we have
87 * enough free space (pa_free) within the prealloc space.
89 * If we can't allocate blocks via inode prealloc or/and locality group
90 * prealloc then we look at the buddy cache. The buddy cache is represented
91 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
92 * mapped to the buddy and bitmap information regarding different
93 * groups. The buddy information is attached to buddy cache inode so that
94 * we can access them through the page cache. The information regarding
95 * each group is loaded via ext4_mb_load_buddy. The information involve
96 * block bitmap and buddy information. The information are stored in the
100 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
103 * one block each for bitmap and buddy information. So for each group we
104 * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
105 * blocksize) blocks. So it can have information regarding groups_per_page
106 * which is blocks_per_page/2
108 * The buddy cache inode is not stored on disk. The inode is thrown
109 * away when the filesystem is unmounted.
111 * We look for count number of blocks in the buddy cache. If we were able
112 * to locate that many free blocks we return with additional information
113 * regarding rest of the contiguous physical block available
115 * Before allocating blocks via buddy cache we normalize the request
116 * blocks. This ensure we ask for more blocks that we needed. The extra
117 * blocks that we get after allocation is added to the respective prealloc
118 * list. In case of inode preallocation we follow a list of heuristics
119 * based on file size. This can be found in ext4_mb_normalize_request. If
120 * we are doing a group prealloc we try to normalize the request to
121 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
122 * dependent on the cluster size; for non-bigalloc file systems, it is
123 * 512 blocks. This can be tuned via
124 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
125 * terms of number of blocks. If we have mounted the file system with -O
126 * stripe=<value> option the group prealloc request is normalized to the
127 * smallest multiple of the stripe value (sbi->s_stripe) which is
128 * greater than the default mb_group_prealloc.
130 * If "mb_optimize_scan" mount option is set, we maintain in memory group info
131 * structures in two data structures:
133 * 1) Array of largest free order lists (sbi->s_mb_largest_free_orders)
135 * Locking: sbi->s_mb_largest_free_orders_locks(array of rw locks)
137 * This is an array of lists where the index in the array represents the
138 * largest free order in the buddy bitmap of the participating group infos of
139 * that list. So, there are exactly MB_NUM_ORDERS(sb) (which means total
140 * number of buddy bitmap orders possible) number of lists. Group-infos are
141 * placed in appropriate lists.
143 * 2) Average fragment size rb tree (sbi->s_mb_avg_fragment_size_root)
145 * Locking: sbi->s_mb_rb_lock (rwlock)
147 * This is a red black tree consisting of group infos and the tree is sorted
148 * by average fragment sizes (which is calculated as ext4_group_info->bb_free
149 * / ext4_group_info->bb_fragments).
151 * When "mb_optimize_scan" mount option is set, mballoc consults the above data
152 * structures to decide the order in which groups are to be traversed for
153 * fulfilling an allocation request.
155 * At CR = 0, we look for groups which have the largest_free_order >= the order
156 * of the request. We directly look at the largest free order list in the data
157 * structure (1) above where largest_free_order = order of the request. If that
158 * list is empty, we look at remaining list in the increasing order of
159 * largest_free_order. This allows us to perform CR = 0 lookup in O(1) time.
161 * At CR = 1, we only consider groups where average fragment size > request
162 * size. So, we lookup a group which has average fragment size just above or
163 * equal to request size using our rb tree (data structure 2) in O(log N) time.
165 * If "mb_optimize_scan" mount option is not set, mballoc traverses groups in
166 * linear order which requires O(N) search time for each CR 0 and CR 1 phase.
168 * The regular allocator (using the buddy cache) supports a few tunables.
170 * /sys/fs/ext4/<partition>/mb_min_to_scan
171 * /sys/fs/ext4/<partition>/mb_max_to_scan
172 * /sys/fs/ext4/<partition>/mb_order2_req
173 * /sys/fs/ext4/<partition>/mb_linear_limit
175 * The regular allocator uses buddy scan only if the request len is power of
176 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
177 * value of s_mb_order2_reqs can be tuned via
178 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
179 * stripe size (sbi->s_stripe), we try to search for contiguous block in
180 * stripe size. This should result in better allocation on RAID setups. If
181 * not, we search in the specific group using bitmap for best extents. The
182 * tunable min_to_scan and max_to_scan control the behaviour here.
183 * min_to_scan indicate how long the mballoc __must__ look for a best
184 * extent and max_to_scan indicates how long the mballoc __can__ look for a
185 * best extent in the found extents. Searching for the blocks starts with
186 * the group specified as the goal value in allocation context via
187 * ac_g_ex. Each group is first checked based on the criteria whether it
188 * can be used for allocation. ext4_mb_good_group explains how the groups are
191 * When "mb_optimize_scan" is turned on, as mentioned above, the groups may not
192 * get traversed linearly. That may result in subsequent allocations being not
193 * close to each other. And so, the underlying device may get filled up in a
194 * non-linear fashion. While that may not matter on non-rotational devices, for
195 * rotational devices that may result in higher seek times. "mb_linear_limit"
196 * tells mballoc how many groups mballoc should search linearly before
197 * performing consulting above data structures for more efficient lookups. For
198 * non rotational devices, this value defaults to 0 and for rotational devices
199 * this is set to MB_DEFAULT_LINEAR_LIMIT.
201 * Both the prealloc space are getting populated as above. So for the first
202 * request we will hit the buddy cache which will result in this prealloc
203 * space getting filled. The prealloc space is then later used for the
204 * subsequent request.
208 * mballoc operates on the following data:
210 * - in-core buddy (actually includes buddy and bitmap)
211 * - preallocation descriptors (PAs)
213 * there are two types of preallocations:
215 * assiged to specific inode and can be used for this inode only.
216 * it describes part of inode's space preallocated to specific
217 * physical blocks. any block from that preallocated can be used
218 * independent. the descriptor just tracks number of blocks left
219 * unused. so, before taking some block from descriptor, one must
220 * make sure corresponded logical block isn't allocated yet. this
221 * also means that freeing any block within descriptor's range
222 * must discard all preallocated blocks.
224 * assigned to specific locality group which does not translate to
225 * permanent set of inodes: inode can join and leave group. space
226 * from this type of preallocation can be used for any inode. thus
227 * it's consumed from the beginning to the end.
229 * relation between them can be expressed as:
230 * in-core buddy = on-disk bitmap + preallocation descriptors
232 * this mean blocks mballoc considers used are:
233 * - allocated blocks (persistent)
234 * - preallocated blocks (non-persistent)
236 * consistency in mballoc world means that at any time a block is either
237 * free or used in ALL structures. notice: "any time" should not be read
238 * literally -- time is discrete and delimited by locks.
240 * to keep it simple, we don't use block numbers, instead we count number of
241 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
243 * all operations can be expressed as:
244 * - init buddy: buddy = on-disk + PAs
245 * - new PA: buddy += N; PA = N
246 * - use inode PA: on-disk += N; PA -= N
247 * - discard inode PA buddy -= on-disk - PA; PA = 0
248 * - use locality group PA on-disk += N; PA -= N
249 * - discard locality group PA buddy -= PA; PA = 0
250 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
251 * is used in real operation because we can't know actual used
252 * bits from PA, only from on-disk bitmap
254 * if we follow this strict logic, then all operations above should be atomic.
255 * given some of them can block, we'd have to use something like semaphores
256 * killing performance on high-end SMP hardware. let's try to relax it using
257 * the following knowledge:
258 * 1) if buddy is referenced, it's already initialized
259 * 2) while block is used in buddy and the buddy is referenced,
260 * nobody can re-allocate that block
261 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
262 * bit set and PA claims same block, it's OK. IOW, one can set bit in
263 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
266 * so, now we're building a concurrency table:
269 * blocks for PA are allocated in the buddy, buddy must be referenced
270 * until PA is linked to allocation group to avoid concurrent buddy init
272 * we need to make sure that either on-disk bitmap or PA has uptodate data
273 * given (3) we care that PA-=N operation doesn't interfere with init
275 * the simplest way would be to have buddy initialized by the discard
276 * - use locality group PA
277 * again PA-=N must be serialized with init
278 * - discard locality group PA
279 * the simplest way would be to have buddy initialized by the discard
282 * i_data_sem serializes them
284 * discard process must wait until PA isn't used by another process
285 * - use locality group PA
286 * some mutex should serialize them
287 * - discard locality group PA
288 * discard process must wait until PA isn't used by another process
291 * i_data_sem or another mutex should serializes them
293 * discard process must wait until PA isn't used by another process
294 * - use locality group PA
295 * nothing wrong here -- they're different PAs covering different blocks
296 * - discard locality group PA
297 * discard process must wait until PA isn't used by another process
299 * now we're ready to make few consequences:
300 * - PA is referenced and while it is no discard is possible
301 * - PA is referenced until block isn't marked in on-disk bitmap
302 * - PA changes only after on-disk bitmap
303 * - discard must not compete with init. either init is done before
304 * any discard or they're serialized somehow
305 * - buddy init as sum of on-disk bitmap and PAs is done atomically
307 * a special case when we've used PA to emptiness. no need to modify buddy
308 * in this case, but we should care about concurrent init
313 * Logic in few words:
318 * mark bits in on-disk bitmap
321 * - use preallocation:
322 * find proper PA (per-inode or group)
324 * mark bits in on-disk bitmap
330 * mark bits in on-disk bitmap
333 * - discard preallocations in group:
335 * move them onto local list
336 * load on-disk bitmap
338 * remove PA from object (inode or locality group)
339 * mark free blocks in-core
341 * - discard inode's preallocations:
348 * - bitlock on a group (group)
349 * - object (inode/locality) (object)
351 * - cr0 lists lock (cr0)
352 * - cr1 tree lock (cr1)
362 * - release consumed pa:
367 * - generate in-core bitmap:
371 * - discard all for given object (inode, locality group):
376 * - discard all for given group:
382 * - allocation path (ext4_mb_regular_allocator)
386 static struct kmem_cache *ext4_pspace_cachep;
387 static struct kmem_cache *ext4_ac_cachep;
388 static struct kmem_cache *ext4_free_data_cachep;
390 /* We create slab caches for groupinfo data structures based on the
391 * superblock block size. There will be one per mounted filesystem for
392 * each unique s_blocksize_bits */
393 #define NR_GRPINFO_CACHES 8
394 static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
396 static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
397 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
398 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
399 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
402 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
404 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
406 static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
408 static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
409 ext4_group_t group, int cr);
411 static int ext4_try_to_trim_range(struct super_block *sb,
412 struct ext4_buddy *e4b, ext4_grpblk_t start,
413 ext4_grpblk_t max, ext4_grpblk_t minblocks);
416 * The algorithm using this percpu seq counter goes below:
417 * 1. We sample the percpu discard_pa_seq counter before trying for block
418 * allocation in ext4_mb_new_blocks().
419 * 2. We increment this percpu discard_pa_seq counter when we either allocate
420 * or free these blocks i.e. while marking those blocks as used/free in
421 * mb_mark_used()/mb_free_blocks().
422 * 3. We also increment this percpu seq counter when we successfully identify
423 * that the bb_prealloc_list is not empty and hence proceed for discarding
424 * of those PAs inside ext4_mb_discard_group_preallocations().
426 * Now to make sure that the regular fast path of block allocation is not
427 * affected, as a small optimization we only sample the percpu seq counter
428 * on that cpu. Only when the block allocation fails and when freed blocks
429 * found were 0, that is when we sample percpu seq counter for all cpus using
430 * below function ext4_get_discard_pa_seq_sum(). This happens after making
431 * sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty.
433 static DEFINE_PER_CPU(u64, discard_pa_seq);
434 static inline u64 ext4_get_discard_pa_seq_sum(void)
439 for_each_possible_cpu(__cpu)
440 __seq += per_cpu(discard_pa_seq, __cpu);
444 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
446 #if BITS_PER_LONG == 64
447 *bit += ((unsigned long) addr & 7UL) << 3;
448 addr = (void *) ((unsigned long) addr & ~7UL);
449 #elif BITS_PER_LONG == 32
450 *bit += ((unsigned long) addr & 3UL) << 3;
451 addr = (void *) ((unsigned long) addr & ~3UL);
453 #error "how many bits you are?!"
458 static inline int mb_test_bit(int bit, void *addr)
461 * ext4_test_bit on architecture like powerpc
462 * needs unsigned long aligned address
464 addr = mb_correct_addr_and_bit(&bit, addr);
465 return ext4_test_bit(bit, addr);
468 static inline void mb_set_bit(int bit, void *addr)
470 addr = mb_correct_addr_and_bit(&bit, addr);
471 ext4_set_bit(bit, addr);
474 static inline void mb_clear_bit(int bit, void *addr)
476 addr = mb_correct_addr_and_bit(&bit, addr);
477 ext4_clear_bit(bit, addr);
480 static inline int mb_test_and_clear_bit(int bit, void *addr)
482 addr = mb_correct_addr_and_bit(&bit, addr);
483 return ext4_test_and_clear_bit(bit, addr);
486 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
488 int fix = 0, ret, tmpmax;
489 addr = mb_correct_addr_and_bit(&fix, addr);
493 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
499 static inline int mb_find_next_bit(void *addr, int max, int start)
501 int fix = 0, ret, tmpmax;
502 addr = mb_correct_addr_and_bit(&fix, addr);
506 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
512 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
516 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
519 if (order > e4b->bd_blkbits + 1) {
524 /* at order 0 we see each particular block */
526 *max = 1 << (e4b->bd_blkbits + 3);
527 return e4b->bd_bitmap;
530 bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
531 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
537 static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
538 int first, int count)
541 struct super_block *sb = e4b->bd_sb;
543 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
545 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
546 for (i = 0; i < count; i++) {
547 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
548 ext4_fsblk_t blocknr;
550 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
551 blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
552 ext4_grp_locked_error(sb, e4b->bd_group,
553 inode ? inode->i_ino : 0,
555 "freeing block already freed "
558 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
559 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
561 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
565 static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
569 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
571 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
572 for (i = 0; i < count; i++) {
573 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
574 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
578 static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
580 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
582 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
583 unsigned char *b1, *b2;
585 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
586 b2 = (unsigned char *) bitmap;
587 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
588 if (b1[i] != b2[i]) {
589 ext4_msg(e4b->bd_sb, KERN_ERR,
590 "corruption in group %u "
591 "at byte %u(%u): %x in copy != %x "
593 e4b->bd_group, i, i * 8, b1[i], b2[i]);
600 static void mb_group_bb_bitmap_alloc(struct super_block *sb,
601 struct ext4_group_info *grp, ext4_group_t group)
603 struct buffer_head *bh;
605 grp->bb_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS);
609 bh = ext4_read_block_bitmap(sb, group);
610 if (IS_ERR_OR_NULL(bh)) {
611 kfree(grp->bb_bitmap);
612 grp->bb_bitmap = NULL;
616 memcpy(grp->bb_bitmap, bh->b_data, sb->s_blocksize);
620 static void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
622 kfree(grp->bb_bitmap);
626 static inline void mb_free_blocks_double(struct inode *inode,
627 struct ext4_buddy *e4b, int first, int count)
631 static inline void mb_mark_used_double(struct ext4_buddy *e4b,
632 int first, int count)
636 static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
641 static inline void mb_group_bb_bitmap_alloc(struct super_block *sb,
642 struct ext4_group_info *grp, ext4_group_t group)
647 static inline void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
653 #ifdef AGGRESSIVE_CHECK
655 #define MB_CHECK_ASSERT(assert) \
659 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
660 function, file, line, # assert); \
665 static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
666 const char *function, int line)
668 struct super_block *sb = e4b->bd_sb;
669 int order = e4b->bd_blkbits + 1;
676 struct ext4_group_info *grp;
679 struct list_head *cur;
683 if (e4b->bd_info->bb_check_counter++ % 10)
687 buddy = mb_find_buddy(e4b, order, &max);
688 MB_CHECK_ASSERT(buddy);
689 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
690 MB_CHECK_ASSERT(buddy2);
691 MB_CHECK_ASSERT(buddy != buddy2);
692 MB_CHECK_ASSERT(max * 2 == max2);
695 for (i = 0; i < max; i++) {
697 if (mb_test_bit(i, buddy)) {
698 /* only single bit in buddy2 may be 1 */
699 if (!mb_test_bit(i << 1, buddy2)) {
701 mb_test_bit((i<<1)+1, buddy2));
702 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
704 mb_test_bit(i << 1, buddy2));
709 /* both bits in buddy2 must be 1 */
710 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
711 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
713 for (j = 0; j < (1 << order); j++) {
714 k = (i * (1 << order)) + j;
716 !mb_test_bit(k, e4b->bd_bitmap));
720 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
725 buddy = mb_find_buddy(e4b, 0, &max);
726 for (i = 0; i < max; i++) {
727 if (!mb_test_bit(i, buddy)) {
728 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
736 /* check used bits only */
737 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
738 buddy2 = mb_find_buddy(e4b, j, &max2);
740 MB_CHECK_ASSERT(k < max2);
741 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
744 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
745 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
747 grp = ext4_get_group_info(sb, e4b->bd_group);
748 list_for_each(cur, &grp->bb_prealloc_list) {
749 ext4_group_t groupnr;
750 struct ext4_prealloc_space *pa;
751 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
752 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
753 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
754 for (i = 0; i < pa->pa_len; i++)
755 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
759 #undef MB_CHECK_ASSERT
760 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
761 __FILE__, __func__, __LINE__)
763 #define mb_check_buddy(e4b)
767 * Divide blocks started from @first with length @len into
768 * smaller chunks with power of 2 blocks.
769 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
770 * then increase bb_counters[] for corresponded chunk size.
772 static void ext4_mb_mark_free_simple(struct super_block *sb,
773 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
774 struct ext4_group_info *grp)
776 struct ext4_sb_info *sbi = EXT4_SB(sb);
782 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
784 border = 2 << sb->s_blocksize_bits;
787 /* find how many blocks can be covered since this position */
788 max = ffs(first | border) - 1;
790 /* find how many blocks of power 2 we need to mark */
797 /* mark multiblock chunks only */
798 grp->bb_counters[min]++;
800 mb_clear_bit(first >> min,
801 buddy + sbi->s_mb_offsets[min]);
808 static void ext4_mb_rb_insert(struct rb_root *root, struct rb_node *new,
809 int (*cmp)(struct rb_node *, struct rb_node *))
811 struct rb_node **iter = &root->rb_node, *parent = NULL;
815 if (cmp(new, *iter) > 0)
816 iter = &((*iter)->rb_left);
818 iter = &((*iter)->rb_right);
821 rb_link_node(new, parent, iter);
822 rb_insert_color(new, root);
826 ext4_mb_avg_fragment_size_cmp(struct rb_node *rb1, struct rb_node *rb2)
828 struct ext4_group_info *grp1 = rb_entry(rb1,
829 struct ext4_group_info,
830 bb_avg_fragment_size_rb);
831 struct ext4_group_info *grp2 = rb_entry(rb2,
832 struct ext4_group_info,
833 bb_avg_fragment_size_rb);
834 int num_frags_1, num_frags_2;
836 num_frags_1 = grp1->bb_fragments ?
837 grp1->bb_free / grp1->bb_fragments : 0;
838 num_frags_2 = grp2->bb_fragments ?
839 grp2->bb_free / grp2->bb_fragments : 0;
841 return (num_frags_2 - num_frags_1);
845 * Reinsert grpinfo into the avg_fragment_size tree with new average
849 mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
851 struct ext4_sb_info *sbi = EXT4_SB(sb);
853 if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0)
856 write_lock(&sbi->s_mb_rb_lock);
857 if (!RB_EMPTY_NODE(&grp->bb_avg_fragment_size_rb)) {
858 rb_erase(&grp->bb_avg_fragment_size_rb,
859 &sbi->s_mb_avg_fragment_size_root);
860 RB_CLEAR_NODE(&grp->bb_avg_fragment_size_rb);
863 ext4_mb_rb_insert(&sbi->s_mb_avg_fragment_size_root,
864 &grp->bb_avg_fragment_size_rb,
865 ext4_mb_avg_fragment_size_cmp);
866 write_unlock(&sbi->s_mb_rb_lock);
870 * Choose next group by traversing largest_free_order lists. Updates *new_cr if
871 * cr level needs an update.
873 static void ext4_mb_choose_next_group_cr0(struct ext4_allocation_context *ac,
874 int *new_cr, ext4_group_t *group, ext4_group_t ngroups)
876 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
877 struct ext4_group_info *iter, *grp;
880 if (ac->ac_status == AC_STATUS_FOUND)
883 if (unlikely(sbi->s_mb_stats && ac->ac_flags & EXT4_MB_CR0_OPTIMIZED))
884 atomic_inc(&sbi->s_bal_cr0_bad_suggestions);
887 for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) {
888 if (list_empty(&sbi->s_mb_largest_free_orders[i]))
890 read_lock(&sbi->s_mb_largest_free_orders_locks[i]);
891 if (list_empty(&sbi->s_mb_largest_free_orders[i])) {
892 read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
896 list_for_each_entry(iter, &sbi->s_mb_largest_free_orders[i],
897 bb_largest_free_order_node) {
899 atomic64_inc(&sbi->s_bal_cX_groups_considered[0]);
900 if (likely(ext4_mb_good_group(ac, iter->bb_group, 0))) {
905 read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
911 /* Increment cr and search again */
914 *group = grp->bb_group;
915 ac->ac_last_optimal_group = *group;
916 ac->ac_flags |= EXT4_MB_CR0_OPTIMIZED;
921 * Choose next group by traversing average fragment size tree. Updates *new_cr
922 * if cr lvel needs an update. Sets EXT4_MB_SEARCH_NEXT_LINEAR to indicate that
923 * the linear search should continue for one iteration since there's lock
924 * contention on the rb tree lock.
926 static void ext4_mb_choose_next_group_cr1(struct ext4_allocation_context *ac,
927 int *new_cr, ext4_group_t *group, ext4_group_t ngroups)
929 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
930 int avg_fragment_size, best_so_far;
931 struct rb_node *node, *found;
932 struct ext4_group_info *grp;
935 * If there is contention on the lock, instead of waiting for the lock
936 * to become available, just continue searching lineraly. We'll resume
937 * our rb tree search later starting at ac->ac_last_optimal_group.
939 if (!read_trylock(&sbi->s_mb_rb_lock)) {
940 ac->ac_flags |= EXT4_MB_SEARCH_NEXT_LINEAR;
944 if (unlikely(ac->ac_flags & EXT4_MB_CR1_OPTIMIZED)) {
946 atomic_inc(&sbi->s_bal_cr1_bad_suggestions);
947 /* We have found something at CR 1 in the past */
948 grp = ext4_get_group_info(ac->ac_sb, ac->ac_last_optimal_group);
949 for (found = rb_next(&grp->bb_avg_fragment_size_rb); found != NULL;
950 found = rb_next(found)) {
951 grp = rb_entry(found, struct ext4_group_info,
952 bb_avg_fragment_size_rb);
954 atomic64_inc(&sbi->s_bal_cX_groups_considered[1]);
955 if (likely(ext4_mb_good_group(ac, grp->bb_group, 1)))
961 node = sbi->s_mb_avg_fragment_size_root.rb_node;
966 grp = rb_entry(node, struct ext4_group_info,
967 bb_avg_fragment_size_rb);
968 avg_fragment_size = 0;
969 if (ext4_mb_good_group(ac, grp->bb_group, 1)) {
970 avg_fragment_size = grp->bb_fragments ?
971 grp->bb_free / grp->bb_fragments : 0;
972 if (!best_so_far || avg_fragment_size < best_so_far) {
973 best_so_far = avg_fragment_size;
977 if (avg_fragment_size > ac->ac_g_ex.fe_len)
978 node = node->rb_right;
980 node = node->rb_left;
985 grp = rb_entry(found, struct ext4_group_info,
986 bb_avg_fragment_size_rb);
987 *group = grp->bb_group;
988 ac->ac_flags |= EXT4_MB_CR1_OPTIMIZED;
993 read_unlock(&sbi->s_mb_rb_lock);
994 ac->ac_last_optimal_group = *group;
997 static inline int should_optimize_scan(struct ext4_allocation_context *ac)
999 if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN)))
1001 if (ac->ac_criteria >= 2)
1003 if (ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))
1009 * Return next linear group for allocation. If linear traversal should not be
1010 * performed, this function just returns the same group
1013 next_linear_group(struct ext4_allocation_context *ac, int group, int ngroups)
1015 if (!should_optimize_scan(ac))
1016 goto inc_and_return;
1018 if (ac->ac_groups_linear_remaining) {
1019 ac->ac_groups_linear_remaining--;
1020 goto inc_and_return;
1023 if (ac->ac_flags & EXT4_MB_SEARCH_NEXT_LINEAR) {
1024 ac->ac_flags &= ~EXT4_MB_SEARCH_NEXT_LINEAR;
1025 goto inc_and_return;
1031 * Artificially restricted ngroups for non-extent
1032 * files makes group > ngroups possible on first loop.
1034 return group + 1 >= ngroups ? 0 : group + 1;
1038 * ext4_mb_choose_next_group: choose next group for allocation.
1040 * @ac Allocation Context
1041 * @new_cr This is an output parameter. If the there is no good group
1042 * available at current CR level, this field is updated to indicate
1043 * the new cr level that should be used.
1044 * @group This is an input / output parameter. As an input it indicates the
1045 * next group that the allocator intends to use for allocation. As
1046 * output, this field indicates the next group that should be used as
1047 * determined by the optimization functions.
1048 * @ngroups Total number of groups
1050 static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac,
1051 int *new_cr, ext4_group_t *group, ext4_group_t ngroups)
1053 *new_cr = ac->ac_criteria;
1055 if (!should_optimize_scan(ac) || ac->ac_groups_linear_remaining)
1059 ext4_mb_choose_next_group_cr0(ac, new_cr, group, ngroups);
1060 } else if (*new_cr == 1) {
1061 ext4_mb_choose_next_group_cr1(ac, new_cr, group, ngroups);
1064 * TODO: For CR=2, we can arrange groups in an rb tree sorted by
1065 * bb_free. But until that happens, we should never come here.
1072 * Cache the order of the largest free extent we have available in this block
1076 mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
1078 struct ext4_sb_info *sbi = EXT4_SB(sb);
1081 if (test_opt2(sb, MB_OPTIMIZE_SCAN) && grp->bb_largest_free_order >= 0) {
1082 write_lock(&sbi->s_mb_largest_free_orders_locks[
1083 grp->bb_largest_free_order]);
1084 list_del_init(&grp->bb_largest_free_order_node);
1085 write_unlock(&sbi->s_mb_largest_free_orders_locks[
1086 grp->bb_largest_free_order]);
1088 grp->bb_largest_free_order = -1; /* uninit */
1090 for (i = MB_NUM_ORDERS(sb) - 1; i >= 0; i--) {
1091 if (grp->bb_counters[i] > 0) {
1092 grp->bb_largest_free_order = i;
1096 if (test_opt2(sb, MB_OPTIMIZE_SCAN) &&
1097 grp->bb_largest_free_order >= 0 && grp->bb_free) {
1098 write_lock(&sbi->s_mb_largest_free_orders_locks[
1099 grp->bb_largest_free_order]);
1100 list_add_tail(&grp->bb_largest_free_order_node,
1101 &sbi->s_mb_largest_free_orders[grp->bb_largest_free_order]);
1102 write_unlock(&sbi->s_mb_largest_free_orders_locks[
1103 grp->bb_largest_free_order]);
1107 static noinline_for_stack
1108 void ext4_mb_generate_buddy(struct super_block *sb,
1109 void *buddy, void *bitmap, ext4_group_t group)
1111 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1112 struct ext4_sb_info *sbi = EXT4_SB(sb);
1113 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
1114 ext4_grpblk_t i = 0;
1115 ext4_grpblk_t first;
1118 unsigned fragments = 0;
1119 unsigned long long period = get_cycles();
1121 /* initialize buddy from bitmap which is aggregation
1122 * of on-disk bitmap and preallocations */
1123 i = mb_find_next_zero_bit(bitmap, max, 0);
1124 grp->bb_first_free = i;
1128 i = mb_find_next_bit(bitmap, max, i);
1132 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
1134 grp->bb_counters[0]++;
1136 i = mb_find_next_zero_bit(bitmap, max, i);
1138 grp->bb_fragments = fragments;
1140 if (free != grp->bb_free) {
1141 ext4_grp_locked_error(sb, group, 0, 0,
1142 "block bitmap and bg descriptor "
1143 "inconsistent: %u vs %u free clusters",
1144 free, grp->bb_free);
1146 * If we intend to continue, we consider group descriptor
1147 * corrupt and update bb_free using bitmap value
1149 grp->bb_free = free;
1150 ext4_mark_group_bitmap_corrupted(sb, group,
1151 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1153 mb_set_largest_free_order(sb, grp);
1155 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
1157 period = get_cycles() - period;
1158 atomic_inc(&sbi->s_mb_buddies_generated);
1159 atomic64_add(period, &sbi->s_mb_generation_time);
1160 mb_update_avg_fragment_size(sb, grp);
1163 /* The buddy information is attached the buddy cache inode
1164 * for convenience. The information regarding each group
1165 * is loaded via ext4_mb_load_buddy. The information involve
1166 * block bitmap and buddy information. The information are
1167 * stored in the inode as
1170 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
1173 * one block each for bitmap and buddy information.
1174 * So for each group we take up 2 blocks. A page can
1175 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
1176 * So it can have information regarding groups_per_page which
1177 * is blocks_per_page/2
1179 * Locking note: This routine takes the block group lock of all groups
1180 * for this page; do not hold this lock when calling this routine!
1183 static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
1185 ext4_group_t ngroups;
1187 int blocks_per_page;
1188 int groups_per_page;
1191 ext4_group_t first_group, group;
1193 struct super_block *sb;
1194 struct buffer_head *bhs;
1195 struct buffer_head **bh = NULL;
1196 struct inode *inode;
1199 struct ext4_group_info *grinfo;
1201 inode = page->mapping->host;
1203 ngroups = ext4_get_groups_count(sb);
1204 blocksize = i_blocksize(inode);
1205 blocks_per_page = PAGE_SIZE / blocksize;
1207 mb_debug(sb, "init page %lu\n", page->index);
1209 groups_per_page = blocks_per_page >> 1;
1210 if (groups_per_page == 0)
1211 groups_per_page = 1;
1213 /* allocate buffer_heads to read bitmaps */
1214 if (groups_per_page > 1) {
1215 i = sizeof(struct buffer_head *) * groups_per_page;
1216 bh = kzalloc(i, gfp);
1224 first_group = page->index * blocks_per_page / 2;
1226 /* read all groups the page covers into the cache */
1227 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1228 if (group >= ngroups)
1231 grinfo = ext4_get_group_info(sb, group);
1233 * If page is uptodate then we came here after online resize
1234 * which added some new uninitialized group info structs, so
1235 * we must skip all initialized uptodate buddies on the page,
1236 * which may be currently in use by an allocating task.
1238 if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
1242 bh[i] = ext4_read_block_bitmap_nowait(sb, group, false);
1243 if (IS_ERR(bh[i])) {
1244 err = PTR_ERR(bh[i]);
1248 mb_debug(sb, "read bitmap for group %u\n", group);
1251 /* wait for I/O completion */
1252 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1257 err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
1262 first_block = page->index * blocks_per_page;
1263 for (i = 0; i < blocks_per_page; i++) {
1264 group = (first_block + i) >> 1;
1265 if (group >= ngroups)
1268 if (!bh[group - first_group])
1269 /* skip initialized uptodate buddy */
1272 if (!buffer_verified(bh[group - first_group]))
1273 /* Skip faulty bitmaps */
1278 * data carry information regarding this
1279 * particular group in the format specified
1283 data = page_address(page) + (i * blocksize);
1284 bitmap = bh[group - first_group]->b_data;
1287 * We place the buddy block and bitmap block
1290 if ((first_block + i) & 1) {
1291 /* this is block of buddy */
1292 BUG_ON(incore == NULL);
1293 mb_debug(sb, "put buddy for group %u in page %lu/%x\n",
1294 group, page->index, i * blocksize);
1295 trace_ext4_mb_buddy_bitmap_load(sb, group);
1296 grinfo = ext4_get_group_info(sb, group);
1297 grinfo->bb_fragments = 0;
1298 memset(grinfo->bb_counters, 0,
1299 sizeof(*grinfo->bb_counters) *
1300 (MB_NUM_ORDERS(sb)));
1302 * incore got set to the group block bitmap below
1304 ext4_lock_group(sb, group);
1305 /* init the buddy */
1306 memset(data, 0xff, blocksize);
1307 ext4_mb_generate_buddy(sb, data, incore, group);
1308 ext4_unlock_group(sb, group);
1311 /* this is block of bitmap */
1312 BUG_ON(incore != NULL);
1313 mb_debug(sb, "put bitmap for group %u in page %lu/%x\n",
1314 group, page->index, i * blocksize);
1315 trace_ext4_mb_bitmap_load(sb, group);
1317 /* see comments in ext4_mb_put_pa() */
1318 ext4_lock_group(sb, group);
1319 memcpy(data, bitmap, blocksize);
1321 /* mark all preallocated blks used in in-core bitmap */
1322 ext4_mb_generate_from_pa(sb, data, group);
1323 ext4_mb_generate_from_freelist(sb, data, group);
1324 ext4_unlock_group(sb, group);
1326 /* set incore so that the buddy information can be
1327 * generated using this
1332 SetPageUptodate(page);
1336 for (i = 0; i < groups_per_page; i++)
1345 * Lock the buddy and bitmap pages. This make sure other parallel init_group
1346 * on the same buddy page doesn't happen whild holding the buddy page lock.
1347 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
1348 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
1350 static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
1351 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
1353 struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
1354 int block, pnum, poff;
1355 int blocks_per_page;
1358 e4b->bd_buddy_page = NULL;
1359 e4b->bd_bitmap_page = NULL;
1361 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1363 * the buddy cache inode stores the block bitmap
1364 * and buddy information in consecutive blocks.
1365 * So for each group we need two blocks.
1368 pnum = block / blocks_per_page;
1369 poff = block % blocks_per_page;
1370 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1373 BUG_ON(page->mapping != inode->i_mapping);
1374 e4b->bd_bitmap_page = page;
1375 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1377 if (blocks_per_page >= 2) {
1378 /* buddy and bitmap are on the same page */
1383 pnum = block / blocks_per_page;
1384 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1387 BUG_ON(page->mapping != inode->i_mapping);
1388 e4b->bd_buddy_page = page;
1392 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1394 if (e4b->bd_bitmap_page) {
1395 unlock_page(e4b->bd_bitmap_page);
1396 put_page(e4b->bd_bitmap_page);
1398 if (e4b->bd_buddy_page) {
1399 unlock_page(e4b->bd_buddy_page);
1400 put_page(e4b->bd_buddy_page);
1405 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1406 * block group lock of all groups for this page; do not hold the BG lock when
1407 * calling this routine!
1409 static noinline_for_stack
1410 int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1413 struct ext4_group_info *this_grp;
1414 struct ext4_buddy e4b;
1419 mb_debug(sb, "init group %u\n", group);
1420 this_grp = ext4_get_group_info(sb, group);
1422 * This ensures that we don't reinit the buddy cache
1423 * page which map to the group from which we are already
1424 * allocating. If we are looking at the buddy cache we would
1425 * have taken a reference using ext4_mb_load_buddy and that
1426 * would have pinned buddy page to page cache.
1427 * The call to ext4_mb_get_buddy_page_lock will mark the
1430 ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp);
1431 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1433 * somebody initialized the group
1434 * return without doing anything
1439 page = e4b.bd_bitmap_page;
1440 ret = ext4_mb_init_cache(page, NULL, gfp);
1443 if (!PageUptodate(page)) {
1448 if (e4b.bd_buddy_page == NULL) {
1450 * If both the bitmap and buddy are in
1451 * the same page we don't need to force
1457 /* init buddy cache */
1458 page = e4b.bd_buddy_page;
1459 ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp);
1462 if (!PageUptodate(page)) {
1467 ext4_mb_put_buddy_page_lock(&e4b);
1472 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1473 * block group lock of all groups for this page; do not hold the BG lock when
1474 * calling this routine!
1476 static noinline_for_stack int
1477 ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1478 struct ext4_buddy *e4b, gfp_t gfp)
1480 int blocks_per_page;
1486 struct ext4_group_info *grp;
1487 struct ext4_sb_info *sbi = EXT4_SB(sb);
1488 struct inode *inode = sbi->s_buddy_cache;
1491 mb_debug(sb, "load group %u\n", group);
1493 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1494 grp = ext4_get_group_info(sb, group);
1496 e4b->bd_blkbits = sb->s_blocksize_bits;
1499 e4b->bd_group = group;
1500 e4b->bd_buddy_page = NULL;
1501 e4b->bd_bitmap_page = NULL;
1503 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1505 * we need full data about the group
1506 * to make a good selection
1508 ret = ext4_mb_init_group(sb, group, gfp);
1514 * the buddy cache inode stores the block bitmap
1515 * and buddy information in consecutive blocks.
1516 * So for each group we need two blocks.
1519 pnum = block / blocks_per_page;
1520 poff = block % blocks_per_page;
1522 /* we could use find_or_create_page(), but it locks page
1523 * what we'd like to avoid in fast path ... */
1524 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1525 if (page == NULL || !PageUptodate(page)) {
1528 * drop the page reference and try
1529 * to get the page with lock. If we
1530 * are not uptodate that implies
1531 * somebody just created the page but
1532 * is yet to initialize the same. So
1533 * wait for it to initialize.
1536 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1538 BUG_ON(page->mapping != inode->i_mapping);
1539 if (!PageUptodate(page)) {
1540 ret = ext4_mb_init_cache(page, NULL, gfp);
1545 mb_cmp_bitmaps(e4b, page_address(page) +
1546 (poff * sb->s_blocksize));
1555 if (!PageUptodate(page)) {
1560 /* Pages marked accessed already */
1561 e4b->bd_bitmap_page = page;
1562 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1565 pnum = block / blocks_per_page;
1566 poff = block % blocks_per_page;
1568 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1569 if (page == NULL || !PageUptodate(page)) {
1572 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1574 BUG_ON(page->mapping != inode->i_mapping);
1575 if (!PageUptodate(page)) {
1576 ret = ext4_mb_init_cache(page, e4b->bd_bitmap,
1590 if (!PageUptodate(page)) {
1595 /* Pages marked accessed already */
1596 e4b->bd_buddy_page = page;
1597 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1604 if (e4b->bd_bitmap_page)
1605 put_page(e4b->bd_bitmap_page);
1606 if (e4b->bd_buddy_page)
1607 put_page(e4b->bd_buddy_page);
1608 e4b->bd_buddy = NULL;
1609 e4b->bd_bitmap = NULL;
1613 static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1614 struct ext4_buddy *e4b)
1616 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1619 static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1621 if (e4b->bd_bitmap_page)
1622 put_page(e4b->bd_bitmap_page);
1623 if (e4b->bd_buddy_page)
1624 put_page(e4b->bd_buddy_page);
1628 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1633 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1634 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1636 while (order <= e4b->bd_blkbits + 1) {
1637 bb = mb_find_buddy(e4b, order, &max);
1638 if (!mb_test_bit(block >> order, bb)) {
1639 /* this block is part of buddy of order 'order' */
1647 static void mb_clear_bits(void *bm, int cur, int len)
1653 if ((cur & 31) == 0 && (len - cur) >= 32) {
1654 /* fast path: clear whole word at once */
1655 addr = bm + (cur >> 3);
1660 mb_clear_bit(cur, bm);
1665 /* clear bits in given range
1666 * will return first found zero bit if any, -1 otherwise
1668 static int mb_test_and_clear_bits(void *bm, int cur, int len)
1675 if ((cur & 31) == 0 && (len - cur) >= 32) {
1676 /* fast path: clear whole word at once */
1677 addr = bm + (cur >> 3);
1678 if (*addr != (__u32)(-1) && zero_bit == -1)
1679 zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0);
1684 if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1)
1692 void ext4_set_bits(void *bm, int cur, int len)
1698 if ((cur & 31) == 0 && (len - cur) >= 32) {
1699 /* fast path: set whole word at once */
1700 addr = bm + (cur >> 3);
1705 mb_set_bit(cur, bm);
1710 static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1712 if (mb_test_bit(*bit + side, bitmap)) {
1713 mb_clear_bit(*bit, bitmap);
1719 mb_set_bit(*bit, bitmap);
1724 static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1728 void *buddy = mb_find_buddy(e4b, order, &max);
1733 /* Bits in range [first; last] are known to be set since
1734 * corresponding blocks were allocated. Bits in range
1735 * (first; last) will stay set because they form buddies on
1736 * upper layer. We just deal with borders if they don't
1737 * align with upper layer and then go up.
1738 * Releasing entire group is all about clearing
1739 * single bit of highest order buddy.
1743 * ---------------------------------
1745 * ---------------------------------
1746 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1747 * ---------------------------------
1749 * \_____________________/
1751 * Neither [1] nor [6] is aligned to above layer.
1752 * Left neighbour [0] is free, so mark it busy,
1753 * decrease bb_counters and extend range to
1755 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1756 * mark [6] free, increase bb_counters and shrink range to
1758 * Then shift range to [0; 2], go up and do the same.
1763 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1);
1765 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1);
1770 if (first == last || !(buddy2 = mb_find_buddy(e4b, order, &max))) {
1771 mb_clear_bits(buddy, first, last - first + 1);
1772 e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1781 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1782 int first, int count)
1784 int left_is_free = 0;
1785 int right_is_free = 0;
1787 int last = first + count - 1;
1788 struct super_block *sb = e4b->bd_sb;
1790 if (WARN_ON(count == 0))
1792 BUG_ON(last >= (sb->s_blocksize << 3));
1793 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1794 /* Don't bother if the block group is corrupt. */
1795 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1798 mb_check_buddy(e4b);
1799 mb_free_blocks_double(inode, e4b, first, count);
1801 this_cpu_inc(discard_pa_seq);
1802 e4b->bd_info->bb_free += count;
1803 if (first < e4b->bd_info->bb_first_free)
1804 e4b->bd_info->bb_first_free = first;
1806 /* access memory sequentially: check left neighbour,
1807 * clear range and then check right neighbour
1810 left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap);
1811 block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count);
1812 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1813 right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap);
1815 if (unlikely(block != -1)) {
1816 struct ext4_sb_info *sbi = EXT4_SB(sb);
1817 ext4_fsblk_t blocknr;
1819 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
1820 blocknr += EXT4_C2B(sbi, block);
1821 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1822 ext4_grp_locked_error(sb, e4b->bd_group,
1823 inode ? inode->i_ino : 0,
1825 "freeing already freed block (bit %u); block bitmap corrupt.",
1827 ext4_mark_group_bitmap_corrupted(
1829 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1834 /* let's maintain fragments counter */
1835 if (left_is_free && right_is_free)
1836 e4b->bd_info->bb_fragments--;
1837 else if (!left_is_free && !right_is_free)
1838 e4b->bd_info->bb_fragments++;
1840 /* buddy[0] == bd_bitmap is a special case, so handle
1841 * it right away and let mb_buddy_mark_free stay free of
1842 * zero order checks.
1843 * Check if neighbours are to be coaleasced,
1844 * adjust bitmap bb_counters and borders appropriately.
1847 first += !left_is_free;
1848 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
1851 last -= !right_is_free;
1852 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
1856 mb_buddy_mark_free(e4b, first >> 1, last >> 1);
1859 mb_set_largest_free_order(sb, e4b->bd_info);
1860 mb_update_avg_fragment_size(sb, e4b->bd_info);
1861 mb_check_buddy(e4b);
1864 static int mb_find_extent(struct ext4_buddy *e4b, int block,
1865 int needed, struct ext4_free_extent *ex)
1871 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1874 buddy = mb_find_buddy(e4b, 0, &max);
1875 BUG_ON(buddy == NULL);
1876 BUG_ON(block >= max);
1877 if (mb_test_bit(block, buddy)) {
1884 /* find actual order */
1885 order = mb_find_order_for_block(e4b, block);
1886 block = block >> order;
1888 ex->fe_len = 1 << order;
1889 ex->fe_start = block << order;
1890 ex->fe_group = e4b->bd_group;
1892 /* calc difference from given start */
1893 next = next - ex->fe_start;
1895 ex->fe_start += next;
1897 while (needed > ex->fe_len &&
1898 mb_find_buddy(e4b, order, &max)) {
1900 if (block + 1 >= max)
1903 next = (block + 1) * (1 << order);
1904 if (mb_test_bit(next, e4b->bd_bitmap))
1907 order = mb_find_order_for_block(e4b, next);
1909 block = next >> order;
1910 ex->fe_len += 1 << order;
1913 if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
1914 /* Should never happen! (but apparently sometimes does?!?) */
1916 ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0,
1917 "corruption or bug in mb_find_extent "
1918 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
1919 block, order, needed, ex->fe_group, ex->fe_start,
1920 ex->fe_len, ex->fe_logical);
1928 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1934 int start = ex->fe_start;
1935 int len = ex->fe_len;
1940 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1941 BUG_ON(e4b->bd_group != ex->fe_group);
1942 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1943 mb_check_buddy(e4b);
1944 mb_mark_used_double(e4b, start, len);
1946 this_cpu_inc(discard_pa_seq);
1947 e4b->bd_info->bb_free -= len;
1948 if (e4b->bd_info->bb_first_free == start)
1949 e4b->bd_info->bb_first_free += len;
1951 /* let's maintain fragments counter */
1953 mlen = !mb_test_bit(start - 1, e4b->bd_bitmap);
1954 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1955 max = !mb_test_bit(start + len, e4b->bd_bitmap);
1957 e4b->bd_info->bb_fragments++;
1958 else if (!mlen && !max)
1959 e4b->bd_info->bb_fragments--;
1961 /* let's maintain buddy itself */
1963 ord = mb_find_order_for_block(e4b, start);
1965 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1966 /* the whole chunk may be allocated at once! */
1968 buddy = mb_find_buddy(e4b, ord, &max);
1969 BUG_ON((start >> ord) >= max);
1970 mb_set_bit(start >> ord, buddy);
1971 e4b->bd_info->bb_counters[ord]--;
1978 /* store for history */
1980 ret = len | (ord << 16);
1982 /* we have to split large buddy */
1984 buddy = mb_find_buddy(e4b, ord, &max);
1985 mb_set_bit(start >> ord, buddy);
1986 e4b->bd_info->bb_counters[ord]--;
1989 cur = (start >> ord) & ~1U;
1990 buddy = mb_find_buddy(e4b, ord, &max);
1991 mb_clear_bit(cur, buddy);
1992 mb_clear_bit(cur + 1, buddy);
1993 e4b->bd_info->bb_counters[ord]++;
1994 e4b->bd_info->bb_counters[ord]++;
1996 mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
1998 mb_update_avg_fragment_size(e4b->bd_sb, e4b->bd_info);
1999 ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
2000 mb_check_buddy(e4b);
2006 * Must be called under group lock!
2008 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
2009 struct ext4_buddy *e4b)
2011 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2014 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
2015 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2017 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
2018 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
2019 ret = mb_mark_used(e4b, &ac->ac_b_ex);
2021 /* preallocation can change ac_b_ex, thus we store actually
2022 * allocated blocks for history */
2023 ac->ac_f_ex = ac->ac_b_ex;
2025 ac->ac_status = AC_STATUS_FOUND;
2026 ac->ac_tail = ret & 0xffff;
2027 ac->ac_buddy = ret >> 16;
2030 * take the page reference. We want the page to be pinned
2031 * so that we don't get a ext4_mb_init_cache_call for this
2032 * group until we update the bitmap. That would mean we
2033 * double allocate blocks. The reference is dropped
2034 * in ext4_mb_release_context
2036 ac->ac_bitmap_page = e4b->bd_bitmap_page;
2037 get_page(ac->ac_bitmap_page);
2038 ac->ac_buddy_page = e4b->bd_buddy_page;
2039 get_page(ac->ac_buddy_page);
2040 /* store last allocated for subsequent stream allocation */
2041 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2042 spin_lock(&sbi->s_md_lock);
2043 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
2044 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
2045 spin_unlock(&sbi->s_md_lock);
2048 * As we've just preallocated more space than
2049 * user requested originally, we store allocated
2050 * space in a special descriptor.
2052 if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
2053 ext4_mb_new_preallocation(ac);
2057 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
2058 struct ext4_buddy *e4b,
2061 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2062 struct ext4_free_extent *bex = &ac->ac_b_ex;
2063 struct ext4_free_extent *gex = &ac->ac_g_ex;
2064 struct ext4_free_extent ex;
2067 if (ac->ac_status == AC_STATUS_FOUND)
2070 * We don't want to scan for a whole year
2072 if (ac->ac_found > sbi->s_mb_max_to_scan &&
2073 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2074 ac->ac_status = AC_STATUS_BREAK;
2079 * Haven't found good chunk so far, let's continue
2081 if (bex->fe_len < gex->fe_len)
2084 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
2085 && bex->fe_group == e4b->bd_group) {
2086 /* recheck chunk's availability - we don't know
2087 * when it was found (within this lock-unlock
2089 max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex);
2090 if (max >= gex->fe_len) {
2091 ext4_mb_use_best_found(ac, e4b);
2098 * The routine checks whether found extent is good enough. If it is,
2099 * then the extent gets marked used and flag is set to the context
2100 * to stop scanning. Otherwise, the extent is compared with the
2101 * previous found extent and if new one is better, then it's stored
2102 * in the context. Later, the best found extent will be used, if
2103 * mballoc can't find good enough extent.
2105 * FIXME: real allocation policy is to be designed yet!
2107 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
2108 struct ext4_free_extent *ex,
2109 struct ext4_buddy *e4b)
2111 struct ext4_free_extent *bex = &ac->ac_b_ex;
2112 struct ext4_free_extent *gex = &ac->ac_g_ex;
2114 BUG_ON(ex->fe_len <= 0);
2115 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2116 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2117 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
2122 * The special case - take what you catch first
2124 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2126 ext4_mb_use_best_found(ac, e4b);
2131 * Let's check whether the chuck is good enough
2133 if (ex->fe_len == gex->fe_len) {
2135 ext4_mb_use_best_found(ac, e4b);
2140 * If this is first found extent, just store it in the context
2142 if (bex->fe_len == 0) {
2148 * If new found extent is better, store it in the context
2150 if (bex->fe_len < gex->fe_len) {
2151 /* if the request isn't satisfied, any found extent
2152 * larger than previous best one is better */
2153 if (ex->fe_len > bex->fe_len)
2155 } else if (ex->fe_len > gex->fe_len) {
2156 /* if the request is satisfied, then we try to find
2157 * an extent that still satisfy the request, but is
2158 * smaller than previous one */
2159 if (ex->fe_len < bex->fe_len)
2163 ext4_mb_check_limits(ac, e4b, 0);
2166 static noinline_for_stack
2167 int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
2168 struct ext4_buddy *e4b)
2170 struct ext4_free_extent ex = ac->ac_b_ex;
2171 ext4_group_t group = ex.fe_group;
2175 BUG_ON(ex.fe_len <= 0);
2176 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
2180 ext4_lock_group(ac->ac_sb, group);
2181 max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex);
2185 ext4_mb_use_best_found(ac, e4b);
2188 ext4_unlock_group(ac->ac_sb, group);
2189 ext4_mb_unload_buddy(e4b);
2194 static noinline_for_stack
2195 int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
2196 struct ext4_buddy *e4b)
2198 ext4_group_t group = ac->ac_g_ex.fe_group;
2201 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2202 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2203 struct ext4_free_extent ex;
2205 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
2207 if (grp->bb_free == 0)
2210 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
2214 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) {
2215 ext4_mb_unload_buddy(e4b);
2219 ext4_lock_group(ac->ac_sb, group);
2220 max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
2221 ac->ac_g_ex.fe_len, &ex);
2222 ex.fe_logical = 0xDEADFA11; /* debug value */
2224 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
2227 start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) +
2229 /* use do_div to get remainder (would be 64-bit modulo) */
2230 if (do_div(start, sbi->s_stripe) == 0) {
2233 ext4_mb_use_best_found(ac, e4b);
2235 } else if (max >= ac->ac_g_ex.fe_len) {
2236 BUG_ON(ex.fe_len <= 0);
2237 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2238 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2241 ext4_mb_use_best_found(ac, e4b);
2242 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
2243 /* Sometimes, caller may want to merge even small
2244 * number of blocks to an existing extent */
2245 BUG_ON(ex.fe_len <= 0);
2246 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2247 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2250 ext4_mb_use_best_found(ac, e4b);
2252 ext4_unlock_group(ac->ac_sb, group);
2253 ext4_mb_unload_buddy(e4b);
2259 * The routine scans buddy structures (not bitmap!) from given order
2260 * to max order and tries to find big enough chunk to satisfy the req
2262 static noinline_for_stack
2263 void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
2264 struct ext4_buddy *e4b)
2266 struct super_block *sb = ac->ac_sb;
2267 struct ext4_group_info *grp = e4b->bd_info;
2273 BUG_ON(ac->ac_2order <= 0);
2274 for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) {
2275 if (grp->bb_counters[i] == 0)
2278 buddy = mb_find_buddy(e4b, i, &max);
2279 BUG_ON(buddy == NULL);
2281 k = mb_find_next_zero_bit(buddy, max, 0);
2283 ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0,
2284 "%d free clusters of order %d. But found 0",
2285 grp->bb_counters[i], i);
2286 ext4_mark_group_bitmap_corrupted(ac->ac_sb,
2288 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2293 ac->ac_b_ex.fe_len = 1 << i;
2294 ac->ac_b_ex.fe_start = k << i;
2295 ac->ac_b_ex.fe_group = e4b->bd_group;
2297 ext4_mb_use_best_found(ac, e4b);
2299 BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len);
2301 if (EXT4_SB(sb)->s_mb_stats)
2302 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
2309 * The routine scans the group and measures all found extents.
2310 * In order to optimize scanning, caller must pass number of
2311 * free blocks in the group, so the routine can know upper limit.
2313 static noinline_for_stack
2314 void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
2315 struct ext4_buddy *e4b)
2317 struct super_block *sb = ac->ac_sb;
2318 void *bitmap = e4b->bd_bitmap;
2319 struct ext4_free_extent ex;
2323 free = e4b->bd_info->bb_free;
2324 if (WARN_ON(free <= 0))
2327 i = e4b->bd_info->bb_first_free;
2329 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
2330 i = mb_find_next_zero_bit(bitmap,
2331 EXT4_CLUSTERS_PER_GROUP(sb), i);
2332 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
2334 * IF we have corrupt bitmap, we won't find any
2335 * free blocks even though group info says we
2338 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2339 "%d free clusters as per "
2340 "group info. But bitmap says 0",
2342 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
2343 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2347 mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex);
2348 if (WARN_ON(ex.fe_len <= 0))
2350 if (free < ex.fe_len) {
2351 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2352 "%d free clusters as per "
2353 "group info. But got %d blocks",
2355 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
2356 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2358 * The number of free blocks differs. This mostly
2359 * indicate that the bitmap is corrupt. So exit
2360 * without claiming the space.
2364 ex.fe_logical = 0xDEADC0DE; /* debug value */
2365 ext4_mb_measure_extent(ac, &ex, e4b);
2371 ext4_mb_check_limits(ac, e4b, 1);
2375 * This is a special case for storages like raid5
2376 * we try to find stripe-aligned chunks for stripe-size-multiple requests
2378 static noinline_for_stack
2379 void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
2380 struct ext4_buddy *e4b)
2382 struct super_block *sb = ac->ac_sb;
2383 struct ext4_sb_info *sbi = EXT4_SB(sb);
2384 void *bitmap = e4b->bd_bitmap;
2385 struct ext4_free_extent ex;
2386 ext4_fsblk_t first_group_block;
2391 BUG_ON(sbi->s_stripe == 0);
2393 /* find first stripe-aligned block in group */
2394 first_group_block = ext4_group_first_block_no(sb, e4b->bd_group);
2396 a = first_group_block + sbi->s_stripe - 1;
2397 do_div(a, sbi->s_stripe);
2398 i = (a * sbi->s_stripe) - first_group_block;
2400 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2401 if (!mb_test_bit(i, bitmap)) {
2402 max = mb_find_extent(e4b, i, sbi->s_stripe, &ex);
2403 if (max >= sbi->s_stripe) {
2405 ex.fe_logical = 0xDEADF00D; /* debug value */
2407 ext4_mb_use_best_found(ac, e4b);
2416 * This is also called BEFORE we load the buddy bitmap.
2417 * Returns either 1 or 0 indicating that the group is either suitable
2418 * for the allocation or not.
2420 static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
2421 ext4_group_t group, int cr)
2423 ext4_grpblk_t free, fragments;
2424 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
2425 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2427 BUG_ON(cr < 0 || cr >= 4);
2429 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2432 free = grp->bb_free;
2436 fragments = grp->bb_fragments;
2442 BUG_ON(ac->ac_2order == 0);
2444 /* Avoid using the first bg of a flexgroup for data files */
2445 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2446 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2447 ((group % flex_size) == 0))
2450 if (free < ac->ac_g_ex.fe_len)
2453 if (ac->ac_2order >= MB_NUM_ORDERS(ac->ac_sb))
2456 if (grp->bb_largest_free_order < ac->ac_2order)
2461 if ((free / fragments) >= ac->ac_g_ex.fe_len)
2465 if (free >= ac->ac_g_ex.fe_len)
2478 * This could return negative error code if something goes wrong
2479 * during ext4_mb_init_group(). This should not be called with
2480 * ext4_lock_group() held.
2482 * Note: because we are conditionally operating with the group lock in
2483 * the EXT4_MB_STRICT_CHECK case, we need to fake out sparse in this
2484 * function using __acquire and __release. This means we need to be
2485 * super careful before messing with the error path handling via "goto
2488 static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac,
2489 ext4_group_t group, int cr)
2491 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2492 struct super_block *sb = ac->ac_sb;
2493 struct ext4_sb_info *sbi = EXT4_SB(sb);
2494 bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK;
2498 if (sbi->s_mb_stats)
2499 atomic64_inc(&sbi->s_bal_cX_groups_considered[ac->ac_criteria]);
2501 ext4_lock_group(sb, group);
2502 __release(ext4_group_lock_ptr(sb, group));
2504 free = grp->bb_free;
2507 if (cr <= 2 && free < ac->ac_g_ex.fe_len)
2509 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2512 __acquire(ext4_group_lock_ptr(sb, group));
2513 ext4_unlock_group(sb, group);
2516 /* We only do this if the grp has never been initialized */
2517 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2518 struct ext4_group_desc *gdp =
2519 ext4_get_group_desc(sb, group, NULL);
2522 /* cr=0/1 is a very optimistic search to find large
2523 * good chunks almost for free. If buddy data is not
2524 * ready, then this optimization makes no sense. But
2525 * we never skip the first block group in a flex_bg,
2526 * since this gets used for metadata block allocation,
2527 * and we want to make sure we locate metadata blocks
2528 * in the first block group in the flex_bg if possible.
2531 (!sbi->s_log_groups_per_flex ||
2532 ((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) &&
2533 !(ext4_has_group_desc_csum(sb) &&
2534 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))))
2536 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
2542 ext4_lock_group(sb, group);
2543 __release(ext4_group_lock_ptr(sb, group));
2545 ret = ext4_mb_good_group(ac, group, cr);
2548 __acquire(ext4_group_lock_ptr(sb, group));
2549 ext4_unlock_group(sb, group);
2555 * Start prefetching @nr block bitmaps starting at @group.
2556 * Return the next group which needs to be prefetched.
2558 ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group,
2559 unsigned int nr, int *cnt)
2561 ext4_group_t ngroups = ext4_get_groups_count(sb);
2562 struct buffer_head *bh;
2563 struct blk_plug plug;
2565 blk_start_plug(&plug);
2567 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group,
2569 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
2572 * Prefetch block groups with free blocks; but don't
2573 * bother if it is marked uninitialized on disk, since
2574 * it won't require I/O to read. Also only try to
2575 * prefetch once, so we avoid getblk() call, which can
2578 if (!EXT4_MB_GRP_TEST_AND_SET_READ(grp) &&
2579 EXT4_MB_GRP_NEED_INIT(grp) &&
2580 ext4_free_group_clusters(sb, gdp) > 0 &&
2581 !(ext4_has_group_desc_csum(sb) &&
2582 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) {
2583 bh = ext4_read_block_bitmap_nowait(sb, group, true);
2584 if (bh && !IS_ERR(bh)) {
2585 if (!buffer_uptodate(bh) && cnt)
2590 if (++group >= ngroups)
2593 blk_finish_plug(&plug);
2598 * Prefetching reads the block bitmap into the buffer cache; but we
2599 * need to make sure that the buddy bitmap in the page cache has been
2600 * initialized. Note that ext4_mb_init_group() will block if the I/O
2601 * is not yet completed, or indeed if it was not initiated by
2602 * ext4_mb_prefetch did not start the I/O.
2604 * TODO: We should actually kick off the buddy bitmap setup in a work
2605 * queue when the buffer I/O is completed, so that we don't block
2606 * waiting for the block allocation bitmap read to finish when
2607 * ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator().
2609 void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
2613 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group,
2615 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
2618 group = ext4_get_groups_count(sb);
2620 grp = ext4_get_group_info(sb, group);
2622 if (EXT4_MB_GRP_NEED_INIT(grp) &&
2623 ext4_free_group_clusters(sb, gdp) > 0 &&
2624 !(ext4_has_group_desc_csum(sb) &&
2625 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) {
2626 if (ext4_mb_init_group(sb, group, GFP_NOFS))
2632 static noinline_for_stack int
2633 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2635 ext4_group_t prefetch_grp = 0, ngroups, group, i;
2637 int err = 0, first_err = 0;
2638 unsigned int nr = 0, prefetch_ios = 0;
2639 struct ext4_sb_info *sbi;
2640 struct super_block *sb;
2641 struct ext4_buddy e4b;
2646 ngroups = ext4_get_groups_count(sb);
2647 /* non-extent files are limited to low blocks/groups */
2648 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)))
2649 ngroups = sbi->s_blockfile_groups;
2651 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2653 /* first, try the goal */
2654 err = ext4_mb_find_by_goal(ac, &e4b);
2655 if (err || ac->ac_status == AC_STATUS_FOUND)
2658 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2662 * ac->ac_2order is set only if the fe_len is a power of 2
2663 * if ac->ac_2order is set we also set criteria to 0 so that we
2664 * try exact allocation using buddy.
2666 i = fls(ac->ac_g_ex.fe_len);
2669 * We search using buddy data only if the order of the request
2670 * is greater than equal to the sbi_s_mb_order2_reqs
2671 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2672 * We also support searching for power-of-two requests only for
2673 * requests upto maximum buddy size we have constructed.
2675 if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) {
2677 * This should tell if fe_len is exactly power of 2
2679 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
2680 ac->ac_2order = array_index_nospec(i - 1,
2684 /* if stream allocation is enabled, use global goal */
2685 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2686 /* TBD: may be hot point */
2687 spin_lock(&sbi->s_md_lock);
2688 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2689 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2690 spin_unlock(&sbi->s_md_lock);
2693 /* Let's just scan groups to find more-less suitable blocks */
2694 cr = ac->ac_2order ? 0 : 1;
2696 * cr == 0 try to get exact allocation,
2697 * cr == 3 try to get anything
2700 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2701 ac->ac_criteria = cr;
2703 * searching for the right group start
2704 * from the goal value specified
2706 group = ac->ac_g_ex.fe_group;
2707 ac->ac_last_optimal_group = group;
2708 ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups;
2709 prefetch_grp = group;
2711 for (i = 0; i < ngroups; group = next_linear_group(ac, group, ngroups),
2713 int ret = 0, new_cr;
2717 ext4_mb_choose_next_group(ac, &new_cr, &group, ngroups);
2724 * Batch reads of the block allocation bitmaps
2725 * to get multiple READs in flight; limit
2726 * prefetching at cr=0/1, otherwise mballoc can
2727 * spend a lot of time loading imperfect groups
2729 if ((prefetch_grp == group) &&
2731 prefetch_ios < sbi->s_mb_prefetch_limit)) {
2732 unsigned int curr_ios = prefetch_ios;
2734 nr = sbi->s_mb_prefetch;
2735 if (ext4_has_feature_flex_bg(sb)) {
2736 nr = 1 << sbi->s_log_groups_per_flex;
2737 nr -= group & (nr - 1);
2738 nr = min(nr, sbi->s_mb_prefetch);
2740 prefetch_grp = ext4_mb_prefetch(sb, group,
2742 if (prefetch_ios == curr_ios)
2746 /* This now checks without needing the buddy page */
2747 ret = ext4_mb_good_group_nolock(ac, group, cr);
2754 err = ext4_mb_load_buddy(sb, group, &e4b);
2758 ext4_lock_group(sb, group);
2761 * We need to check again after locking the
2764 ret = ext4_mb_good_group(ac, group, cr);
2766 ext4_unlock_group(sb, group);
2767 ext4_mb_unload_buddy(&e4b);
2771 ac->ac_groups_scanned++;
2773 ext4_mb_simple_scan_group(ac, &e4b);
2774 else if (cr == 1 && sbi->s_stripe &&
2775 !(ac->ac_g_ex.fe_len % sbi->s_stripe))
2776 ext4_mb_scan_aligned(ac, &e4b);
2778 ext4_mb_complex_scan_group(ac, &e4b);
2780 ext4_unlock_group(sb, group);
2781 ext4_mb_unload_buddy(&e4b);
2783 if (ac->ac_status != AC_STATUS_CONTINUE)
2786 /* Processed all groups and haven't found blocks */
2787 if (sbi->s_mb_stats && i == ngroups)
2788 atomic64_inc(&sbi->s_bal_cX_failed[cr]);
2791 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2792 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2794 * We've been searching too long. Let's try to allocate
2795 * the best chunk we've found so far
2797 ext4_mb_try_best_found(ac, &e4b);
2798 if (ac->ac_status != AC_STATUS_FOUND) {
2800 * Someone more lucky has already allocated it.
2801 * The only thing we can do is just take first
2804 lost = atomic_inc_return(&sbi->s_mb_lost_chunks);
2805 mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n",
2806 ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start,
2807 ac->ac_b_ex.fe_len, lost);
2809 ac->ac_b_ex.fe_group = 0;
2810 ac->ac_b_ex.fe_start = 0;
2811 ac->ac_b_ex.fe_len = 0;
2812 ac->ac_status = AC_STATUS_CONTINUE;
2813 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2819 if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND)
2820 atomic64_inc(&sbi->s_bal_cX_hits[ac->ac_criteria]);
2822 if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
2825 mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
2826 ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status,
2827 ac->ac_flags, cr, err);
2830 ext4_mb_prefetch_fini(sb, prefetch_grp, nr);
2835 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2837 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2840 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2843 return (void *) ((unsigned long) group);
2846 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2848 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2852 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2855 return (void *) ((unsigned long) group);
2858 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2860 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2861 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
2863 int err, buddy_loaded = 0;
2864 struct ext4_buddy e4b;
2865 struct ext4_group_info *grinfo;
2866 unsigned char blocksize_bits = min_t(unsigned char,
2867 sb->s_blocksize_bits,
2868 EXT4_MAX_BLOCK_LOG_SIZE);
2870 struct ext4_group_info info;
2871 ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
2876 seq_puts(seq, "#group: free frags first ["
2877 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
2878 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
2880 i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2881 sizeof(struct ext4_group_info);
2883 grinfo = ext4_get_group_info(sb, group);
2884 /* Load the group info in memory only if not already loaded. */
2885 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
2886 err = ext4_mb_load_buddy(sb, group, &e4b);
2888 seq_printf(seq, "#%-5u: I/O error\n", group);
2894 memcpy(&sg, ext4_get_group_info(sb, group), i);
2897 ext4_mb_unload_buddy(&e4b);
2899 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
2900 sg.info.bb_fragments, sg.info.bb_first_free);
2901 for (i = 0; i <= 13; i++)
2902 seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
2903 sg.info.bb_counters[i] : 0);
2904 seq_puts(seq, " ]\n");
2909 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2913 const struct seq_operations ext4_mb_seq_groups_ops = {
2914 .start = ext4_mb_seq_groups_start,
2915 .next = ext4_mb_seq_groups_next,
2916 .stop = ext4_mb_seq_groups_stop,
2917 .show = ext4_mb_seq_groups_show,
2920 int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
2922 struct super_block *sb = (struct super_block *)seq->private;
2923 struct ext4_sb_info *sbi = EXT4_SB(sb);
2925 seq_puts(seq, "mballoc:\n");
2926 if (!sbi->s_mb_stats) {
2927 seq_puts(seq, "\tmb stats collection turned off.\n");
2928 seq_puts(seq, "\tTo enable, please write \"1\" to sysfs file mb_stats.\n");
2931 seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs));
2932 seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success));
2934 seq_printf(seq, "\tgroups_scanned: %u\n", atomic_read(&sbi->s_bal_groups_scanned));
2936 seq_puts(seq, "\tcr0_stats:\n");
2937 seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[0]));
2938 seq_printf(seq, "\t\tgroups_considered: %llu\n",
2939 atomic64_read(&sbi->s_bal_cX_groups_considered[0]));
2940 seq_printf(seq, "\t\tuseless_loops: %llu\n",
2941 atomic64_read(&sbi->s_bal_cX_failed[0]));
2942 seq_printf(seq, "\t\tbad_suggestions: %u\n",
2943 atomic_read(&sbi->s_bal_cr0_bad_suggestions));
2945 seq_puts(seq, "\tcr1_stats:\n");
2946 seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[1]));
2947 seq_printf(seq, "\t\tgroups_considered: %llu\n",
2948 atomic64_read(&sbi->s_bal_cX_groups_considered[1]));
2949 seq_printf(seq, "\t\tuseless_loops: %llu\n",
2950 atomic64_read(&sbi->s_bal_cX_failed[1]));
2951 seq_printf(seq, "\t\tbad_suggestions: %u\n",
2952 atomic_read(&sbi->s_bal_cr1_bad_suggestions));
2954 seq_puts(seq, "\tcr2_stats:\n");
2955 seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[2]));
2956 seq_printf(seq, "\t\tgroups_considered: %llu\n",
2957 atomic64_read(&sbi->s_bal_cX_groups_considered[2]));
2958 seq_printf(seq, "\t\tuseless_loops: %llu\n",
2959 atomic64_read(&sbi->s_bal_cX_failed[2]));
2961 seq_puts(seq, "\tcr3_stats:\n");
2962 seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[3]));
2963 seq_printf(seq, "\t\tgroups_considered: %llu\n",
2964 atomic64_read(&sbi->s_bal_cX_groups_considered[3]));
2965 seq_printf(seq, "\t\tuseless_loops: %llu\n",
2966 atomic64_read(&sbi->s_bal_cX_failed[3]));
2967 seq_printf(seq, "\textents_scanned: %u\n", atomic_read(&sbi->s_bal_ex_scanned));
2968 seq_printf(seq, "\t\tgoal_hits: %u\n", atomic_read(&sbi->s_bal_goals));
2969 seq_printf(seq, "\t\t2^n_hits: %u\n", atomic_read(&sbi->s_bal_2orders));
2970 seq_printf(seq, "\t\tbreaks: %u\n", atomic_read(&sbi->s_bal_breaks));
2971 seq_printf(seq, "\t\tlost: %u\n", atomic_read(&sbi->s_mb_lost_chunks));
2973 seq_printf(seq, "\tbuddies_generated: %u/%u\n",
2974 atomic_read(&sbi->s_mb_buddies_generated),
2975 ext4_get_groups_count(sb));
2976 seq_printf(seq, "\tbuddies_time_used: %llu\n",
2977 atomic64_read(&sbi->s_mb_generation_time));
2978 seq_printf(seq, "\tpreallocated: %u\n",
2979 atomic_read(&sbi->s_mb_preallocated));
2980 seq_printf(seq, "\tdiscarded: %u\n",
2981 atomic_read(&sbi->s_mb_discarded));
2985 static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos)
2986 __acquires(&EXT4_SB(sb)->s_mb_rb_lock)
2988 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2989 unsigned long position;
2991 read_lock(&EXT4_SB(sb)->s_mb_rb_lock);
2993 if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1)
2995 position = *pos + 1;
2996 return (void *) ((unsigned long) position);
2999 static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos)
3001 struct super_block *sb = PDE_DATA(file_inode(seq->file));
3002 unsigned long position;
3005 if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1)
3007 position = *pos + 1;
3008 return (void *) ((unsigned long) position);
3011 static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v)
3013 struct super_block *sb = PDE_DATA(file_inode(seq->file));
3014 struct ext4_sb_info *sbi = EXT4_SB(sb);
3015 unsigned long position = ((unsigned long) v);
3016 struct ext4_group_info *grp;
3018 unsigned int count, min, max;
3021 if (position >= MB_NUM_ORDERS(sb)) {
3022 seq_puts(seq, "fragment_size_tree:\n");
3023 n = rb_first(&sbi->s_mb_avg_fragment_size_root);
3025 seq_puts(seq, "\ttree_min: 0\n\ttree_max: 0\n\ttree_nodes: 0\n");
3028 grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb);
3029 min = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0;
3031 while (rb_next(n)) {
3035 grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb);
3036 max = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0;
3038 seq_printf(seq, "\ttree_min: %u\n\ttree_max: %u\n\ttree_nodes: %u\n",
3043 if (position == 0) {
3044 seq_printf(seq, "optimize_scan: %d\n",
3045 test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0);
3046 seq_puts(seq, "max_free_order_lists:\n");
3049 list_for_each_entry(grp, &sbi->s_mb_largest_free_orders[position],
3050 bb_largest_free_order_node)
3052 seq_printf(seq, "\tlist_order_%u_groups: %u\n",
3053 (unsigned int)position, count);
3058 static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v)
3059 __releases(&EXT4_SB(sb)->s_mb_rb_lock)
3061 struct super_block *sb = PDE_DATA(file_inode(seq->file));
3063 read_unlock(&EXT4_SB(sb)->s_mb_rb_lock);
3066 const struct seq_operations ext4_mb_seq_structs_summary_ops = {
3067 .start = ext4_mb_seq_structs_summary_start,
3068 .next = ext4_mb_seq_structs_summary_next,
3069 .stop = ext4_mb_seq_structs_summary_stop,
3070 .show = ext4_mb_seq_structs_summary_show,
3073 static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
3075 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3076 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
3083 * Allocate the top-level s_group_info array for the specified number
3086 int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
3088 struct ext4_sb_info *sbi = EXT4_SB(sb);
3090 struct ext4_group_info ***old_groupinfo, ***new_groupinfo;
3092 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
3093 EXT4_DESC_PER_BLOCK_BITS(sb);
3094 if (size <= sbi->s_group_info_size)
3097 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
3098 new_groupinfo = kvzalloc(size, GFP_KERNEL);
3099 if (!new_groupinfo) {
3100 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
3104 old_groupinfo = rcu_dereference(sbi->s_group_info);
3106 memcpy(new_groupinfo, old_groupinfo,
3107 sbi->s_group_info_size * sizeof(*sbi->s_group_info));
3109 rcu_assign_pointer(sbi->s_group_info, new_groupinfo);
3110 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
3112 ext4_kvfree_array_rcu(old_groupinfo);
3113 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
3114 sbi->s_group_info_size);
3118 /* Create and initialize ext4_group_info data for the given group. */
3119 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
3120 struct ext4_group_desc *desc)
3124 int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb);
3125 struct ext4_sb_info *sbi = EXT4_SB(sb);
3126 struct ext4_group_info **meta_group_info;
3127 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
3130 * First check if this group is the first of a reserved block.
3131 * If it's true, we have to allocate a new table of pointers
3132 * to ext4_group_info structures
3134 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3135 metalen = sizeof(*meta_group_info) <<
3136 EXT4_DESC_PER_BLOCK_BITS(sb);
3137 meta_group_info = kmalloc(metalen, GFP_NOFS);
3138 if (meta_group_info == NULL) {
3139 ext4_msg(sb, KERN_ERR, "can't allocate mem "
3140 "for a buddy group");
3141 goto exit_meta_group_info;
3144 rcu_dereference(sbi->s_group_info)[idx] = meta_group_info;
3148 meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx);
3149 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
3151 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
3152 if (meta_group_info[i] == NULL) {
3153 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
3154 goto exit_group_info;
3156 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
3157 &(meta_group_info[i]->bb_state));
3160 * initialize bb_free to be able to skip
3161 * empty groups without initialization
3163 if (ext4_has_group_desc_csum(sb) &&
3164 (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3165 meta_group_info[i]->bb_free =
3166 ext4_free_clusters_after_init(sb, group, desc);
3168 meta_group_info[i]->bb_free =
3169 ext4_free_group_clusters(sb, desc);
3172 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
3173 init_rwsem(&meta_group_info[i]->alloc_sem);
3174 meta_group_info[i]->bb_free_root = RB_ROOT;
3175 INIT_LIST_HEAD(&meta_group_info[i]->bb_largest_free_order_node);
3176 RB_CLEAR_NODE(&meta_group_info[i]->bb_avg_fragment_size_rb);
3177 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
3178 meta_group_info[i]->bb_group = group;
3180 mb_group_bb_bitmap_alloc(sb, meta_group_info[i], group);
3184 /* If a meta_group_info table has been allocated, release it now */
3185 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3186 struct ext4_group_info ***group_info;
3189 group_info = rcu_dereference(sbi->s_group_info);
3190 kfree(group_info[idx]);
3191 group_info[idx] = NULL;
3194 exit_meta_group_info:
3196 } /* ext4_mb_add_groupinfo */
3198 static int ext4_mb_init_backend(struct super_block *sb)
3200 ext4_group_t ngroups = ext4_get_groups_count(sb);
3202 struct ext4_sb_info *sbi = EXT4_SB(sb);
3204 struct ext4_group_desc *desc;
3205 struct ext4_group_info ***group_info;
3206 struct kmem_cache *cachep;
3208 err = ext4_mb_alloc_groupinfo(sb, ngroups);
3212 sbi->s_buddy_cache = new_inode(sb);
3213 if (sbi->s_buddy_cache == NULL) {
3214 ext4_msg(sb, KERN_ERR, "can't get new inode");
3217 /* To avoid potentially colliding with an valid on-disk inode number,
3218 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
3219 * not in the inode hash, so it should never be found by iget(), but
3220 * this will avoid confusion if it ever shows up during debugging. */
3221 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
3222 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
3223 for (i = 0; i < ngroups; i++) {
3225 desc = ext4_get_group_desc(sb, i, NULL);
3227 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
3230 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
3234 if (ext4_has_feature_flex_bg(sb)) {
3235 /* a single flex group is supposed to be read by a single IO.
3236 * 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is
3237 * unsigned integer, so the maximum shift is 32.
3239 if (sbi->s_es->s_log_groups_per_flex >= 32) {
3240 ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group");
3243 sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex,
3244 BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9));
3245 sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */
3247 sbi->s_mb_prefetch = 32;
3249 if (sbi->s_mb_prefetch > ext4_get_groups_count(sb))
3250 sbi->s_mb_prefetch = ext4_get_groups_count(sb);
3251 /* now many real IOs to prefetch within a single allocation at cr=0
3252 * given cr=0 is an CPU-related optimization we shouldn't try to
3253 * load too many groups, at some point we should start to use what
3254 * we've got in memory.
3255 * with an average random access time 5ms, it'd take a second to get
3256 * 200 groups (* N with flex_bg), so let's make this limit 4
3258 sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4;
3259 if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb))
3260 sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb);
3265 cachep = get_groupinfo_cache(sb->s_blocksize_bits);
3267 kmem_cache_free(cachep, ext4_get_group_info(sb, i));
3268 i = sbi->s_group_info_size;
3270 group_info = rcu_dereference(sbi->s_group_info);
3272 kfree(group_info[i]);
3274 iput(sbi->s_buddy_cache);
3277 kvfree(rcu_dereference(sbi->s_group_info));
3282 static void ext4_groupinfo_destroy_slabs(void)
3286 for (i = 0; i < NR_GRPINFO_CACHES; i++) {
3287 kmem_cache_destroy(ext4_groupinfo_caches[i]);
3288 ext4_groupinfo_caches[i] = NULL;
3292 static int ext4_groupinfo_create_slab(size_t size)
3294 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
3296 int blocksize_bits = order_base_2(size);
3297 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3298 struct kmem_cache *cachep;
3300 if (cache_index >= NR_GRPINFO_CACHES)
3303 if (unlikely(cache_index < 0))
3306 mutex_lock(&ext4_grpinfo_slab_create_mutex);
3307 if (ext4_groupinfo_caches[cache_index]) {
3308 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
3309 return 0; /* Already created */
3312 slab_size = offsetof(struct ext4_group_info,
3313 bb_counters[blocksize_bits + 2]);
3315 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
3316 slab_size, 0, SLAB_RECLAIM_ACCOUNT,
3319 ext4_groupinfo_caches[cache_index] = cachep;
3321 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
3324 "EXT4-fs: no memory for groupinfo slab cache\n");
3331 static void ext4_discard_work(struct work_struct *work)
3333 struct ext4_sb_info *sbi = container_of(work,
3334 struct ext4_sb_info, s_discard_work);
3335 struct super_block *sb = sbi->s_sb;
3336 struct ext4_free_data *fd, *nfd;
3337 struct ext4_buddy e4b;
3338 struct list_head discard_list;
3339 ext4_group_t grp, load_grp;
3342 INIT_LIST_HEAD(&discard_list);
3343 spin_lock(&sbi->s_md_lock);
3344 list_splice_init(&sbi->s_discard_list, &discard_list);
3345 spin_unlock(&sbi->s_md_lock);
3347 load_grp = UINT_MAX;
3348 list_for_each_entry_safe(fd, nfd, &discard_list, efd_list) {
3350 * If filesystem is umounting or no memory or suffering
3351 * from no space, give up the discard
3353 if ((sb->s_flags & SB_ACTIVE) && !err &&
3354 !atomic_read(&sbi->s_retry_alloc_pending)) {
3355 grp = fd->efd_group;
3356 if (grp != load_grp) {
3357 if (load_grp != UINT_MAX)
3358 ext4_mb_unload_buddy(&e4b);
3360 err = ext4_mb_load_buddy(sb, grp, &e4b);
3362 kmem_cache_free(ext4_free_data_cachep, fd);
3363 load_grp = UINT_MAX;
3370 ext4_lock_group(sb, grp);
3371 ext4_try_to_trim_range(sb, &e4b, fd->efd_start_cluster,
3372 fd->efd_start_cluster + fd->efd_count - 1, 1);
3373 ext4_unlock_group(sb, grp);
3375 kmem_cache_free(ext4_free_data_cachep, fd);
3378 if (load_grp != UINT_MAX)
3379 ext4_mb_unload_buddy(&e4b);
3382 int ext4_mb_init(struct super_block *sb)
3384 struct ext4_sb_info *sbi = EXT4_SB(sb);
3386 unsigned offset, offset_incr;
3390 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets);
3392 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
3393 if (sbi->s_mb_offsets == NULL) {
3398 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs);
3399 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
3400 if (sbi->s_mb_maxs == NULL) {
3405 ret = ext4_groupinfo_create_slab(sb->s_blocksize);
3409 /* order 0 is regular bitmap */
3410 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
3411 sbi->s_mb_offsets[0] = 0;
3415 offset_incr = 1 << (sb->s_blocksize_bits - 1);
3416 max = sb->s_blocksize << 2;
3418 sbi->s_mb_offsets[i] = offset;
3419 sbi->s_mb_maxs[i] = max;
3420 offset += offset_incr;
3421 offset_incr = offset_incr >> 1;
3424 } while (i < MB_NUM_ORDERS(sb));
3426 sbi->s_mb_avg_fragment_size_root = RB_ROOT;
3427 sbi->s_mb_largest_free_orders =
3428 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head),
3430 if (!sbi->s_mb_largest_free_orders) {
3434 sbi->s_mb_largest_free_orders_locks =
3435 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t),
3437 if (!sbi->s_mb_largest_free_orders_locks) {
3441 for (i = 0; i < MB_NUM_ORDERS(sb); i++) {
3442 INIT_LIST_HEAD(&sbi->s_mb_largest_free_orders[i]);
3443 rwlock_init(&sbi->s_mb_largest_free_orders_locks[i]);
3445 rwlock_init(&sbi->s_mb_rb_lock);
3447 spin_lock_init(&sbi->s_md_lock);
3448 sbi->s_mb_free_pending = 0;
3449 INIT_LIST_HEAD(&sbi->s_freed_data_list);
3450 INIT_LIST_HEAD(&sbi->s_discard_list);
3451 INIT_WORK(&sbi->s_discard_work, ext4_discard_work);
3452 atomic_set(&sbi->s_retry_alloc_pending, 0);
3454 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
3455 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
3456 sbi->s_mb_stats = MB_DEFAULT_STATS;
3457 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
3458 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
3459 sbi->s_mb_max_inode_prealloc = MB_DEFAULT_MAX_INODE_PREALLOC;
3461 * The default group preallocation is 512, which for 4k block
3462 * sizes translates to 2 megabytes. However for bigalloc file
3463 * systems, this is probably too big (i.e, if the cluster size
3464 * is 1 megabyte, then group preallocation size becomes half a
3465 * gigabyte!). As a default, we will keep a two megabyte
3466 * group pralloc size for cluster sizes up to 64k, and after
3467 * that, we will force a minimum group preallocation size of
3468 * 32 clusters. This translates to 8 megs when the cluster
3469 * size is 256k, and 32 megs when the cluster size is 1 meg,
3470 * which seems reasonable as a default.
3472 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
3473 sbi->s_cluster_bits, 32);
3475 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
3476 * to the lowest multiple of s_stripe which is bigger than
3477 * the s_mb_group_prealloc as determined above. We want
3478 * the preallocation size to be an exact multiple of the
3479 * RAID stripe size so that preallocations don't fragment
3482 if (sbi->s_stripe > 1) {
3483 sbi->s_mb_group_prealloc = roundup(
3484 sbi->s_mb_group_prealloc, sbi->s_stripe);
3487 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
3488 if (sbi->s_locality_groups == NULL) {
3492 for_each_possible_cpu(i) {
3493 struct ext4_locality_group *lg;
3494 lg = per_cpu_ptr(sbi->s_locality_groups, i);
3495 mutex_init(&lg->lg_mutex);
3496 for (j = 0; j < PREALLOC_TB_SIZE; j++)
3497 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
3498 spin_lock_init(&lg->lg_prealloc_lock);
3501 if (blk_queue_nonrot(bdev_get_queue(sb->s_bdev)))
3502 sbi->s_mb_max_linear_groups = 0;
3504 sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT;
3505 /* init file for buddy data */
3506 ret = ext4_mb_init_backend(sb);
3508 goto out_free_locality_groups;
3512 out_free_locality_groups:
3513 free_percpu(sbi->s_locality_groups);
3514 sbi->s_locality_groups = NULL;
3516 kfree(sbi->s_mb_largest_free_orders);
3517 kfree(sbi->s_mb_largest_free_orders_locks);
3518 kfree(sbi->s_mb_offsets);
3519 sbi->s_mb_offsets = NULL;
3520 kfree(sbi->s_mb_maxs);
3521 sbi->s_mb_maxs = NULL;
3525 /* need to called with the ext4 group lock held */
3526 static int ext4_mb_cleanup_pa(struct ext4_group_info *grp)
3528 struct ext4_prealloc_space *pa;
3529 struct list_head *cur, *tmp;
3532 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
3533 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3534 list_del(&pa->pa_group_list);
3536 kmem_cache_free(ext4_pspace_cachep, pa);
3541 int ext4_mb_release(struct super_block *sb)
3543 ext4_group_t ngroups = ext4_get_groups_count(sb);
3545 int num_meta_group_infos;
3546 struct ext4_group_info *grinfo, ***group_info;
3547 struct ext4_sb_info *sbi = EXT4_SB(sb);
3548 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
3551 if (test_opt(sb, DISCARD)) {
3553 * wait the discard work to drain all of ext4_free_data
3555 flush_work(&sbi->s_discard_work);
3556 WARN_ON_ONCE(!list_empty(&sbi->s_discard_list));
3559 if (sbi->s_group_info) {
3560 for (i = 0; i < ngroups; i++) {
3562 grinfo = ext4_get_group_info(sb, i);
3563 mb_group_bb_bitmap_free(grinfo);
3564 ext4_lock_group(sb, i);
3565 count = ext4_mb_cleanup_pa(grinfo);
3567 mb_debug(sb, "mballoc: %d PAs left\n",
3569 ext4_unlock_group(sb, i);
3570 kmem_cache_free(cachep, grinfo);
3572 num_meta_group_infos = (ngroups +
3573 EXT4_DESC_PER_BLOCK(sb) - 1) >>
3574 EXT4_DESC_PER_BLOCK_BITS(sb);
3576 group_info = rcu_dereference(sbi->s_group_info);
3577 for (i = 0; i < num_meta_group_infos; i++)
3578 kfree(group_info[i]);
3582 kfree(sbi->s_mb_largest_free_orders);
3583 kfree(sbi->s_mb_largest_free_orders_locks);
3584 kfree(sbi->s_mb_offsets);
3585 kfree(sbi->s_mb_maxs);
3586 iput(sbi->s_buddy_cache);
3587 if (sbi->s_mb_stats) {
3588 ext4_msg(sb, KERN_INFO,
3589 "mballoc: %u blocks %u reqs (%u success)",
3590 atomic_read(&sbi->s_bal_allocated),
3591 atomic_read(&sbi->s_bal_reqs),
3592 atomic_read(&sbi->s_bal_success));
3593 ext4_msg(sb, KERN_INFO,
3594 "mballoc: %u extents scanned, %u groups scanned, %u goal hits, "
3595 "%u 2^N hits, %u breaks, %u lost",
3596 atomic_read(&sbi->s_bal_ex_scanned),
3597 atomic_read(&sbi->s_bal_groups_scanned),
3598 atomic_read(&sbi->s_bal_goals),
3599 atomic_read(&sbi->s_bal_2orders),
3600 atomic_read(&sbi->s_bal_breaks),
3601 atomic_read(&sbi->s_mb_lost_chunks));
3602 ext4_msg(sb, KERN_INFO,
3603 "mballoc: %u generated and it took %llu",
3604 atomic_read(&sbi->s_mb_buddies_generated),
3605 atomic64_read(&sbi->s_mb_generation_time));
3606 ext4_msg(sb, KERN_INFO,
3607 "mballoc: %u preallocated, %u discarded",
3608 atomic_read(&sbi->s_mb_preallocated),
3609 atomic_read(&sbi->s_mb_discarded));
3612 free_percpu(sbi->s_locality_groups);
3617 static inline int ext4_issue_discard(struct super_block *sb,
3618 ext4_group_t block_group, ext4_grpblk_t cluster, int count,
3621 ext4_fsblk_t discard_block;
3623 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
3624 ext4_group_first_block_no(sb, block_group));
3625 count = EXT4_C2B(EXT4_SB(sb), count);
3626 trace_ext4_discard_blocks(sb,
3627 (unsigned long long) discard_block, count);
3629 return __blkdev_issue_discard(sb->s_bdev,
3630 (sector_t)discard_block << (sb->s_blocksize_bits - 9),
3631 (sector_t)count << (sb->s_blocksize_bits - 9),
3634 return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
3637 static void ext4_free_data_in_buddy(struct super_block *sb,
3638 struct ext4_free_data *entry)
3640 struct ext4_buddy e4b;
3641 struct ext4_group_info *db;
3642 int err, count = 0, count2 = 0;
3644 mb_debug(sb, "gonna free %u blocks in group %u (0x%p):",
3645 entry->efd_count, entry->efd_group, entry);
3647 err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
3648 /* we expect to find existing buddy because it's pinned */
3651 spin_lock(&EXT4_SB(sb)->s_md_lock);
3652 EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
3653 spin_unlock(&EXT4_SB(sb)->s_md_lock);
3656 /* there are blocks to put in buddy to make them really free */
3657 count += entry->efd_count;
3659 ext4_lock_group(sb, entry->efd_group);
3660 /* Take it out of per group rb tree */
3661 rb_erase(&entry->efd_node, &(db->bb_free_root));
3662 mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count);
3665 * Clear the trimmed flag for the group so that the next
3666 * ext4_trim_fs can trim it.
3667 * If the volume is mounted with -o discard, online discard
3668 * is supported and the free blocks will be trimmed online.
3670 if (!test_opt(sb, DISCARD))
3671 EXT4_MB_GRP_CLEAR_TRIMMED(db);
3673 if (!db->bb_free_root.rb_node) {
3674 /* No more items in the per group rb tree
3675 * balance refcounts from ext4_mb_free_metadata()
3677 put_page(e4b.bd_buddy_page);
3678 put_page(e4b.bd_bitmap_page);
3680 ext4_unlock_group(sb, entry->efd_group);
3681 ext4_mb_unload_buddy(&e4b);
3683 mb_debug(sb, "freed %d blocks in %d structures\n", count,
3688 * This function is called by the jbd2 layer once the commit has finished,
3689 * so we know we can free the blocks that were released with that commit.
3691 void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
3693 struct ext4_sb_info *sbi = EXT4_SB(sb);
3694 struct ext4_free_data *entry, *tmp;
3695 struct list_head freed_data_list;
3696 struct list_head *cut_pos = NULL;
3699 INIT_LIST_HEAD(&freed_data_list);
3701 spin_lock(&sbi->s_md_lock);
3702 list_for_each_entry(entry, &sbi->s_freed_data_list, efd_list) {
3703 if (entry->efd_tid != commit_tid)
3705 cut_pos = &entry->efd_list;
3708 list_cut_position(&freed_data_list, &sbi->s_freed_data_list,
3710 spin_unlock(&sbi->s_md_lock);
3712 list_for_each_entry(entry, &freed_data_list, efd_list)
3713 ext4_free_data_in_buddy(sb, entry);
3715 if (test_opt(sb, DISCARD)) {
3716 spin_lock(&sbi->s_md_lock);
3717 wake = list_empty(&sbi->s_discard_list);
3718 list_splice_tail(&freed_data_list, &sbi->s_discard_list);
3719 spin_unlock(&sbi->s_md_lock);
3721 queue_work(system_unbound_wq, &sbi->s_discard_work);
3723 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
3724 kmem_cache_free(ext4_free_data_cachep, entry);
3728 int __init ext4_init_mballoc(void)
3730 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
3731 SLAB_RECLAIM_ACCOUNT);
3732 if (ext4_pspace_cachep == NULL)
3735 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
3736 SLAB_RECLAIM_ACCOUNT);
3737 if (ext4_ac_cachep == NULL)
3740 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
3741 SLAB_RECLAIM_ACCOUNT);
3742 if (ext4_free_data_cachep == NULL)
3748 kmem_cache_destroy(ext4_ac_cachep);
3750 kmem_cache_destroy(ext4_pspace_cachep);
3755 void ext4_exit_mballoc(void)
3758 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
3759 * before destroying the slab cache.
3762 kmem_cache_destroy(ext4_pspace_cachep);
3763 kmem_cache_destroy(ext4_ac_cachep);
3764 kmem_cache_destroy(ext4_free_data_cachep);
3765 ext4_groupinfo_destroy_slabs();
3770 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
3771 * Returns 0 if success or error code
3773 static noinline_for_stack int
3774 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
3775 handle_t *handle, unsigned int reserv_clstrs)
3777 struct buffer_head *bitmap_bh = NULL;
3778 struct ext4_group_desc *gdp;
3779 struct buffer_head *gdp_bh;
3780 struct ext4_sb_info *sbi;
3781 struct super_block *sb;
3785 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3786 BUG_ON(ac->ac_b_ex.fe_len <= 0);
3791 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
3792 if (IS_ERR(bitmap_bh)) {
3793 err = PTR_ERR(bitmap_bh);
3798 BUFFER_TRACE(bitmap_bh, "getting write access");
3799 err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
3805 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
3809 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
3810 ext4_free_group_clusters(sb, gdp));
3812 BUFFER_TRACE(gdp_bh, "get_write_access");
3813 err = ext4_journal_get_write_access(handle, sb, gdp_bh, EXT4_JTR_NONE);
3817 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3819 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
3820 if (!ext4_inode_block_valid(ac->ac_inode, block, len)) {
3821 ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
3822 "fs metadata", block, block+len);
3823 /* File system mounted not to panic on error
3824 * Fix the bitmap and return EFSCORRUPTED
3825 * We leak some of the blocks here.
3827 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3828 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3829 ac->ac_b_ex.fe_len);
3830 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3831 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3833 err = -EFSCORRUPTED;
3837 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3838 #ifdef AGGRESSIVE_CHECK
3841 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3842 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3843 bitmap_bh->b_data));
3847 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3848 ac->ac_b_ex.fe_len);
3849 if (ext4_has_group_desc_csum(sb) &&
3850 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3851 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3852 ext4_free_group_clusters_set(sb, gdp,
3853 ext4_free_clusters_after_init(sb,
3854 ac->ac_b_ex.fe_group, gdp));
3856 len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
3857 ext4_free_group_clusters_set(sb, gdp, len);
3858 ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
3859 ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
3861 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3862 percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
3864 * Now reduce the dirty block count also. Should not go negative
3866 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
3867 /* release all the reserved blocks if non delalloc */
3868 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
3871 if (sbi->s_log_groups_per_flex) {
3872 ext4_group_t flex_group = ext4_flex_group(sbi,
3873 ac->ac_b_ex.fe_group);
3874 atomic64_sub(ac->ac_b_ex.fe_len,
3875 &sbi_array_rcu_deref(sbi, s_flex_groups,
3876 flex_group)->free_clusters);
3879 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3882 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
3890 * Idempotent helper for Ext4 fast commit replay path to set the state of
3891 * blocks in bitmaps and update counters.
3893 void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
3896 struct buffer_head *bitmap_bh = NULL;
3897 struct ext4_group_desc *gdp;
3898 struct buffer_head *gdp_bh;
3899 struct ext4_sb_info *sbi = EXT4_SB(sb);
3901 ext4_grpblk_t blkoff;
3904 unsigned int clen, clen_changed, thisgrp_len;
3907 ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
3910 * Check to see if we are freeing blocks across a group
3912 * In case of flex_bg, this can happen that (block, len) may
3913 * span across more than one group. In that case we need to
3914 * get the corresponding group metadata to work with.
3915 * For this we have goto again loop.
3917 thisgrp_len = min_t(unsigned int, (unsigned int)len,
3918 EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
3919 clen = EXT4_NUM_B2C(sbi, thisgrp_len);
3921 bitmap_bh = ext4_read_block_bitmap(sb, group);
3922 if (IS_ERR(bitmap_bh)) {
3923 err = PTR_ERR(bitmap_bh);
3929 gdp = ext4_get_group_desc(sb, group, &gdp_bh);
3933 ext4_lock_group(sb, group);
3935 for (i = 0; i < clen; i++)
3936 if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) ==
3940 clen_changed = clen - already;
3942 ext4_set_bits(bitmap_bh->b_data, blkoff, clen);
3944 mb_test_and_clear_bits(bitmap_bh->b_data, blkoff, clen);
3945 if (ext4_has_group_desc_csum(sb) &&
3946 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3947 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3948 ext4_free_group_clusters_set(sb, gdp,
3949 ext4_free_clusters_after_init(sb, group, gdp));
3952 clen = ext4_free_group_clusters(sb, gdp) - clen_changed;
3954 clen = ext4_free_group_clusters(sb, gdp) + clen_changed;
3956 ext4_free_group_clusters_set(sb, gdp, clen);
3957 ext4_block_bitmap_csum_set(sb, group, gdp, bitmap_bh);
3958 ext4_group_desc_csum_set(sb, group, gdp);
3960 ext4_unlock_group(sb, group);
3962 if (sbi->s_log_groups_per_flex) {
3963 ext4_group_t flex_group = ext4_flex_group(sbi, group);
3964 struct flex_groups *fg = sbi_array_rcu_deref(sbi,
3965 s_flex_groups, flex_group);
3968 atomic64_sub(clen_changed, &fg->free_clusters);
3970 atomic64_add(clen_changed, &fg->free_clusters);
3974 err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh);
3977 sync_dirty_buffer(bitmap_bh);
3978 err = ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
3979 sync_dirty_buffer(gdp_bh);
3983 block += thisgrp_len;
3994 * here we normalize request for locality group
3995 * Group request are normalized to s_mb_group_prealloc, which goes to
3996 * s_strip if we set the same via mount option.
3997 * s_mb_group_prealloc can be configured via
3998 * /sys/fs/ext4/<partition>/mb_group_prealloc
4000 * XXX: should we try to preallocate more than the group has now?
4002 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
4004 struct super_block *sb = ac->ac_sb;
4005 struct ext4_locality_group *lg = ac->ac_lg;
4008 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
4009 mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len);
4013 * Normalization means making request better in terms of
4014 * size and alignment
4016 static noinline_for_stack void
4017 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
4018 struct ext4_allocation_request *ar)
4020 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4023 loff_t size, start_off;
4024 loff_t orig_size __maybe_unused;
4026 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4027 struct ext4_prealloc_space *pa;
4029 /* do normalize only data requests, metadata requests
4030 do not need preallocation */
4031 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4034 /* sometime caller may want exact blocks */
4035 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4038 /* caller may indicate that preallocation isn't
4039 * required (it's a tail, for example) */
4040 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
4043 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
4044 ext4_mb_normalize_group_request(ac);
4048 bsbits = ac->ac_sb->s_blocksize_bits;
4050 /* first, let's learn actual file size
4051 * given current request is allocated */
4052 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
4053 size = size << bsbits;
4054 if (size < i_size_read(ac->ac_inode))
4055 size = i_size_read(ac->ac_inode);
4058 /* max size of free chunks */
4061 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
4062 (req <= (size) || max <= (chunk_size))
4064 /* first, try to predict filesize */
4065 /* XXX: should this table be tunable? */
4067 if (size <= 16 * 1024) {
4069 } else if (size <= 32 * 1024) {
4071 } else if (size <= 64 * 1024) {
4073 } else if (size <= 128 * 1024) {
4075 } else if (size <= 256 * 1024) {
4077 } else if (size <= 512 * 1024) {
4079 } else if (size <= 1024 * 1024) {
4081 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
4082 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4083 (21 - bsbits)) << 21;
4084 size = 2 * 1024 * 1024;
4085 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
4086 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4087 (22 - bsbits)) << 22;
4088 size = 4 * 1024 * 1024;
4089 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
4090 (8<<20)>>bsbits, max, 8 * 1024)) {
4091 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4092 (23 - bsbits)) << 23;
4093 size = 8 * 1024 * 1024;
4095 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
4096 size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
4097 ac->ac_o_ex.fe_len) << bsbits;
4099 size = size >> bsbits;
4100 start = start_off >> bsbits;
4103 * For tiny groups (smaller than 8MB) the chosen allocation
4104 * alignment may be larger than group size. Make sure the
4105 * alignment does not move allocation to a different group which
4106 * makes mballoc fail assertions later.
4108 start = max(start, rounddown(ac->ac_o_ex.fe_logical,
4109 (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
4111 /* don't cover already allocated blocks in selected range */
4112 if (ar->pleft && start <= ar->lleft) {
4113 size -= ar->lleft + 1 - start;
4114 start = ar->lleft + 1;
4116 if (ar->pright && start + size - 1 >= ar->lright)
4117 size -= start + size - ar->lright;
4120 * Trim allocation request for filesystems with artificially small
4123 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
4124 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
4128 /* check we don't cross already preallocated blocks */
4130 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
4135 spin_lock(&pa->pa_lock);
4136 if (pa->pa_deleted) {
4137 spin_unlock(&pa->pa_lock);
4141 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
4144 /* PA must not overlap original request */
4145 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
4146 ac->ac_o_ex.fe_logical < pa->pa_lstart));
4148 /* skip PAs this normalized request doesn't overlap with */
4149 if (pa->pa_lstart >= end || pa_end <= start) {
4150 spin_unlock(&pa->pa_lock);
4153 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
4155 /* adjust start or end to be adjacent to this pa */
4156 if (pa_end <= ac->ac_o_ex.fe_logical) {
4157 BUG_ON(pa_end < start);
4159 } else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
4160 BUG_ON(pa->pa_lstart > end);
4161 end = pa->pa_lstart;
4163 spin_unlock(&pa->pa_lock);
4168 /* XXX: extra loop to check we really don't overlap preallocations */
4170 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
4173 spin_lock(&pa->pa_lock);
4174 if (pa->pa_deleted == 0) {
4175 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
4177 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
4179 spin_unlock(&pa->pa_lock);
4183 if (start + size <= ac->ac_o_ex.fe_logical &&
4184 start > ac->ac_o_ex.fe_logical) {
4185 ext4_msg(ac->ac_sb, KERN_ERR,
4186 "start %lu, size %lu, fe_logical %lu",
4187 (unsigned long) start, (unsigned long) size,
4188 (unsigned long) ac->ac_o_ex.fe_logical);
4191 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
4193 /* now prepare goal request */
4195 /* XXX: is it better to align blocks WRT to logical
4196 * placement or satisfy big request as is */
4197 ac->ac_g_ex.fe_logical = start;
4198 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
4200 /* define goal start in order to merge */
4201 if (ar->pright && (ar->lright == (start + size))) {
4202 /* merge to the right */
4203 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
4204 &ac->ac_f_ex.fe_group,
4205 &ac->ac_f_ex.fe_start);
4206 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4208 if (ar->pleft && (ar->lleft + 1 == start)) {
4209 /* merge to the left */
4210 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
4211 &ac->ac_f_ex.fe_group,
4212 &ac->ac_f_ex.fe_start);
4213 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4216 mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size,
4220 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
4222 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4224 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) {
4225 atomic_inc(&sbi->s_bal_reqs);
4226 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
4227 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
4228 atomic_inc(&sbi->s_bal_success);
4229 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
4230 atomic_add(ac->ac_groups_scanned, &sbi->s_bal_groups_scanned);
4231 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
4232 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
4233 atomic_inc(&sbi->s_bal_goals);
4234 if (ac->ac_found > sbi->s_mb_max_to_scan)
4235 atomic_inc(&sbi->s_bal_breaks);
4238 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
4239 trace_ext4_mballoc_alloc(ac);
4241 trace_ext4_mballoc_prealloc(ac);
4245 * Called on failure; free up any blocks from the inode PA for this
4246 * context. We don't need this for MB_GROUP_PA because we only change
4247 * pa_free in ext4_mb_release_context(), but on failure, we've already
4248 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
4250 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
4252 struct ext4_prealloc_space *pa = ac->ac_pa;
4253 struct ext4_buddy e4b;
4257 if (ac->ac_f_ex.fe_len == 0)
4259 err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
4262 * This should never happen since we pin the
4263 * pages in the ext4_allocation_context so
4264 * ext4_mb_load_buddy() should never fail.
4266 WARN(1, "mb_load_buddy failed (%d)", err);
4269 ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
4270 mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
4271 ac->ac_f_ex.fe_len);
4272 ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
4273 ext4_mb_unload_buddy(&e4b);
4276 if (pa->pa_type == MB_INODE_PA)
4277 pa->pa_free += ac->ac_b_ex.fe_len;
4281 * use blocks preallocated to inode
4283 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
4284 struct ext4_prealloc_space *pa)
4286 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4291 /* found preallocated blocks, use them */
4292 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
4293 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
4294 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
4295 len = EXT4_NUM_B2C(sbi, end - start);
4296 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
4297 &ac->ac_b_ex.fe_start);
4298 ac->ac_b_ex.fe_len = len;
4299 ac->ac_status = AC_STATUS_FOUND;
4302 BUG_ON(start < pa->pa_pstart);
4303 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
4304 BUG_ON(pa->pa_free < len);
4307 mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa);
4311 * use blocks preallocated to locality group
4313 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
4314 struct ext4_prealloc_space *pa)
4316 unsigned int len = ac->ac_o_ex.fe_len;
4318 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
4319 &ac->ac_b_ex.fe_group,
4320 &ac->ac_b_ex.fe_start);
4321 ac->ac_b_ex.fe_len = len;
4322 ac->ac_status = AC_STATUS_FOUND;
4325 /* we don't correct pa_pstart or pa_plen here to avoid
4326 * possible race when the group is being loaded concurrently
4327 * instead we correct pa later, after blocks are marked
4328 * in on-disk bitmap -- see ext4_mb_release_context()
4329 * Other CPUs are prevented from allocating from this pa by lg_mutex
4331 mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n",
4332 pa->pa_lstart-len, len, pa);
4336 * Return the prealloc space that have minimal distance
4337 * from the goal block. @cpa is the prealloc
4338 * space that is having currently known minimal distance
4339 * from the goal block.
4341 static struct ext4_prealloc_space *
4342 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
4343 struct ext4_prealloc_space *pa,
4344 struct ext4_prealloc_space *cpa)
4346 ext4_fsblk_t cur_distance, new_distance;
4349 atomic_inc(&pa->pa_count);
4352 cur_distance = abs(goal_block - cpa->pa_pstart);
4353 new_distance = abs(goal_block - pa->pa_pstart);
4355 if (cur_distance <= new_distance)
4358 /* drop the previous reference */
4359 atomic_dec(&cpa->pa_count);
4360 atomic_inc(&pa->pa_count);
4365 * search goal blocks in preallocated space
4367 static noinline_for_stack bool
4368 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
4370 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4372 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4373 struct ext4_locality_group *lg;
4374 struct ext4_prealloc_space *pa, *cpa = NULL;
4375 ext4_fsblk_t goal_block;
4377 /* only data can be preallocated */
4378 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4381 /* first, try per-file preallocation */
4383 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
4385 /* all fields in this condition don't change,
4386 * so we can skip locking for them */
4387 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
4388 ac->ac_o_ex.fe_logical >= (pa->pa_lstart +
4389 EXT4_C2B(sbi, pa->pa_len)))
4392 /* non-extent files can't have physical blocks past 2^32 */
4393 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) &&
4394 (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) >
4395 EXT4_MAX_BLOCK_FILE_PHYS))
4398 /* found preallocated blocks, use them */
4399 spin_lock(&pa->pa_lock);
4400 if (pa->pa_deleted == 0 && pa->pa_free) {
4401 atomic_inc(&pa->pa_count);
4402 ext4_mb_use_inode_pa(ac, pa);
4403 spin_unlock(&pa->pa_lock);
4404 ac->ac_criteria = 10;
4408 spin_unlock(&pa->pa_lock);
4412 /* can we use group allocation? */
4413 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
4416 /* inode may have no locality group for some reason */
4420 order = fls(ac->ac_o_ex.fe_len) - 1;
4421 if (order > PREALLOC_TB_SIZE - 1)
4422 /* The max size of hash table is PREALLOC_TB_SIZE */
4423 order = PREALLOC_TB_SIZE - 1;
4425 goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex);
4427 * search for the prealloc space that is having
4428 * minimal distance from the goal block.
4430 for (i = order; i < PREALLOC_TB_SIZE; i++) {
4432 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
4434 spin_lock(&pa->pa_lock);
4435 if (pa->pa_deleted == 0 &&
4436 pa->pa_free >= ac->ac_o_ex.fe_len) {
4438 cpa = ext4_mb_check_group_pa(goal_block,
4441 spin_unlock(&pa->pa_lock);
4446 ext4_mb_use_group_pa(ac, cpa);
4447 ac->ac_criteria = 20;
4454 * the function goes through all block freed in the group
4455 * but not yet committed and marks them used in in-core bitmap.
4456 * buddy must be generated from this bitmap
4457 * Need to be called with the ext4 group lock held
4459 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
4463 struct ext4_group_info *grp;
4464 struct ext4_free_data *entry;
4466 grp = ext4_get_group_info(sb, group);
4467 n = rb_first(&(grp->bb_free_root));
4470 entry = rb_entry(n, struct ext4_free_data, efd_node);
4471 ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count);
4478 * the function goes through all preallocation in this group and marks them
4479 * used in in-core bitmap. buddy must be generated from this bitmap
4480 * Need to be called with ext4 group lock held
4482 static noinline_for_stack
4483 void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
4486 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
4487 struct ext4_prealloc_space *pa;
4488 struct list_head *cur;
4489 ext4_group_t groupnr;
4490 ext4_grpblk_t start;
4491 int preallocated = 0;
4494 /* all form of preallocation discards first load group,
4495 * so the only competing code is preallocation use.
4496 * we don't need any locking here
4497 * notice we do NOT ignore preallocations with pa_deleted
4498 * otherwise we could leave used blocks available for
4499 * allocation in buddy when concurrent ext4_mb_put_pa()
4500 * is dropping preallocation
4502 list_for_each(cur, &grp->bb_prealloc_list) {
4503 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
4504 spin_lock(&pa->pa_lock);
4505 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4508 spin_unlock(&pa->pa_lock);
4509 if (unlikely(len == 0))
4511 BUG_ON(groupnr != group);
4512 ext4_set_bits(bitmap, start, len);
4513 preallocated += len;
4515 mb_debug(sb, "preallocated %d for group %u\n", preallocated, group);
4518 static void ext4_mb_mark_pa_deleted(struct super_block *sb,
4519 struct ext4_prealloc_space *pa)
4521 struct ext4_inode_info *ei;
4523 if (pa->pa_deleted) {
4524 ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n",
4525 pa->pa_type, pa->pa_pstart, pa->pa_lstart,
4532 if (pa->pa_type == MB_INODE_PA) {
4533 ei = EXT4_I(pa->pa_inode);
4534 atomic_dec(&ei->i_prealloc_active);
4538 static void ext4_mb_pa_callback(struct rcu_head *head)
4540 struct ext4_prealloc_space *pa;
4541 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
4543 BUG_ON(atomic_read(&pa->pa_count));
4544 BUG_ON(pa->pa_deleted == 0);
4545 kmem_cache_free(ext4_pspace_cachep, pa);
4549 * drops a reference to preallocated space descriptor
4550 * if this was the last reference and the space is consumed
4552 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
4553 struct super_block *sb, struct ext4_prealloc_space *pa)
4556 ext4_fsblk_t grp_blk;
4558 /* in this short window concurrent discard can set pa_deleted */
4559 spin_lock(&pa->pa_lock);
4560 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {
4561 spin_unlock(&pa->pa_lock);
4565 if (pa->pa_deleted == 1) {
4566 spin_unlock(&pa->pa_lock);
4570 ext4_mb_mark_pa_deleted(sb, pa);
4571 spin_unlock(&pa->pa_lock);
4573 grp_blk = pa->pa_pstart;
4575 * If doing group-based preallocation, pa_pstart may be in the
4576 * next group when pa is used up
4578 if (pa->pa_type == MB_GROUP_PA)
4581 grp = ext4_get_group_number(sb, grp_blk);
4586 * P1 (buddy init) P2 (regular allocation)
4587 * find block B in PA
4588 * copy on-disk bitmap to buddy
4589 * mark B in on-disk bitmap
4590 * drop PA from group
4591 * mark all PAs in buddy
4593 * thus, P1 initializes buddy with B available. to prevent this
4594 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
4597 ext4_lock_group(sb, grp);
4598 list_del(&pa->pa_group_list);
4599 ext4_unlock_group(sb, grp);
4601 spin_lock(pa->pa_obj_lock);
4602 list_del_rcu(&pa->pa_inode_list);
4603 spin_unlock(pa->pa_obj_lock);
4605 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4609 * creates new preallocated space for given inode
4611 static noinline_for_stack void
4612 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
4614 struct super_block *sb = ac->ac_sb;
4615 struct ext4_sb_info *sbi = EXT4_SB(sb);
4616 struct ext4_prealloc_space *pa;
4617 struct ext4_group_info *grp;
4618 struct ext4_inode_info *ei;
4620 /* preallocate only when found space is larger then requested */
4621 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
4622 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
4623 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
4624 BUG_ON(ac->ac_pa == NULL);
4628 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
4634 /* we can't allocate as much as normalizer wants.
4635 * so, found space must get proper lstart
4636 * to cover original request */
4637 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
4638 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
4640 /* we're limited by original request in that
4641 * logical block must be covered any way
4642 * winl is window we can move our chunk within */
4643 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
4645 /* also, we should cover whole original request */
4646 wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len);
4648 /* the smallest one defines real window */
4649 win = min(winl, wins);
4651 offs = ac->ac_o_ex.fe_logical %
4652 EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4653 if (offs && offs < win)
4656 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical -
4657 EXT4_NUM_B2C(sbi, win);
4658 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
4659 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
4662 /* preallocation can change ac_b_ex, thus we store actually
4663 * allocated blocks for history */
4664 ac->ac_f_ex = ac->ac_b_ex;
4666 pa->pa_lstart = ac->ac_b_ex.fe_logical;
4667 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4668 pa->pa_len = ac->ac_b_ex.fe_len;
4669 pa->pa_free = pa->pa_len;
4670 spin_lock_init(&pa->pa_lock);
4671 INIT_LIST_HEAD(&pa->pa_inode_list);
4672 INIT_LIST_HEAD(&pa->pa_group_list);
4674 pa->pa_type = MB_INODE_PA;
4676 mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
4677 pa->pa_len, pa->pa_lstart);
4678 trace_ext4_mb_new_inode_pa(ac, pa);
4680 ext4_mb_use_inode_pa(ac, pa);
4681 atomic_add(pa->pa_free, &sbi->s_mb_preallocated);
4683 ei = EXT4_I(ac->ac_inode);
4684 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
4686 pa->pa_obj_lock = &ei->i_prealloc_lock;
4687 pa->pa_inode = ac->ac_inode;
4689 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
4691 spin_lock(pa->pa_obj_lock);
4692 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
4693 spin_unlock(pa->pa_obj_lock);
4694 atomic_inc(&ei->i_prealloc_active);
4698 * creates new preallocated space for locality group inodes belongs to
4700 static noinline_for_stack void
4701 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
4703 struct super_block *sb = ac->ac_sb;
4704 struct ext4_locality_group *lg;
4705 struct ext4_prealloc_space *pa;
4706 struct ext4_group_info *grp;
4708 /* preallocate only when found space is larger then requested */
4709 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
4710 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
4711 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
4712 BUG_ON(ac->ac_pa == NULL);
4716 /* preallocation can change ac_b_ex, thus we store actually
4717 * allocated blocks for history */
4718 ac->ac_f_ex = ac->ac_b_ex;
4720 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4721 pa->pa_lstart = pa->pa_pstart;
4722 pa->pa_len = ac->ac_b_ex.fe_len;
4723 pa->pa_free = pa->pa_len;
4724 spin_lock_init(&pa->pa_lock);
4725 INIT_LIST_HEAD(&pa->pa_inode_list);
4726 INIT_LIST_HEAD(&pa->pa_group_list);
4728 pa->pa_type = MB_GROUP_PA;
4730 mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
4731 pa->pa_len, pa->pa_lstart);
4732 trace_ext4_mb_new_group_pa(ac, pa);
4734 ext4_mb_use_group_pa(ac, pa);
4735 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
4737 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
4741 pa->pa_obj_lock = &lg->lg_prealloc_lock;
4742 pa->pa_inode = NULL;
4744 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
4747 * We will later add the new pa to the right bucket
4748 * after updating the pa_free in ext4_mb_release_context
4752 static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
4754 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4755 ext4_mb_new_group_pa(ac);
4757 ext4_mb_new_inode_pa(ac);
4761 * finds all unused blocks in on-disk bitmap, frees them in
4762 * in-core bitmap and buddy.
4763 * @pa must be unlinked from inode and group lists, so that
4764 * nobody else can find/use it.
4765 * the caller MUST hold group/inode locks.
4766 * TODO: optimize the case when there are no in-core structures yet
4768 static noinline_for_stack int
4769 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
4770 struct ext4_prealloc_space *pa)
4772 struct super_block *sb = e4b->bd_sb;
4773 struct ext4_sb_info *sbi = EXT4_SB(sb);
4778 unsigned long long grp_blk_start;
4781 BUG_ON(pa->pa_deleted == 0);
4782 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
4783 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
4784 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
4785 end = bit + pa->pa_len;
4788 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
4791 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
4792 mb_debug(sb, "free preallocated %u/%u in group %u\n",
4793 (unsigned) ext4_group_first_block_no(sb, group) + bit,
4794 (unsigned) next - bit, (unsigned) group);
4797 trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);
4798 trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +
4799 EXT4_C2B(sbi, bit)),
4801 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
4804 if (free != pa->pa_free) {
4805 ext4_msg(e4b->bd_sb, KERN_CRIT,
4806 "pa %p: logic %lu, phys. %lu, len %d",
4807 pa, (unsigned long) pa->pa_lstart,
4808 (unsigned long) pa->pa_pstart,
4810 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
4813 * pa is already deleted so we use the value obtained
4814 * from the bitmap and continue.
4817 atomic_add(free, &sbi->s_mb_discarded);
4822 static noinline_for_stack int
4823 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
4824 struct ext4_prealloc_space *pa)
4826 struct super_block *sb = e4b->bd_sb;
4830 trace_ext4_mb_release_group_pa(sb, pa);
4831 BUG_ON(pa->pa_deleted == 0);
4832 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
4833 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
4834 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
4835 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
4836 trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);
4842 * releases all preallocations in given group
4844 * first, we need to decide discard policy:
4845 * - when do we discard
4847 * - how many do we discard
4848 * 1) how many requested
4850 static noinline_for_stack int
4851 ext4_mb_discard_group_preallocations(struct super_block *sb,
4852 ext4_group_t group, int *busy)
4854 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
4855 struct buffer_head *bitmap_bh = NULL;
4856 struct ext4_prealloc_space *pa, *tmp;
4857 struct list_head list;
4858 struct ext4_buddy e4b;
4862 mb_debug(sb, "discard preallocation for group %u\n", group);
4863 if (list_empty(&grp->bb_prealloc_list))
4866 bitmap_bh = ext4_read_block_bitmap(sb, group);
4867 if (IS_ERR(bitmap_bh)) {
4868 err = PTR_ERR(bitmap_bh);
4869 ext4_error_err(sb, -err,
4870 "Error %d reading block bitmap for %u",
4875 err = ext4_mb_load_buddy(sb, group, &e4b);
4877 ext4_warning(sb, "Error %d loading buddy information for %u",
4883 INIT_LIST_HEAD(&list);
4884 ext4_lock_group(sb, group);
4885 list_for_each_entry_safe(pa, tmp,
4886 &grp->bb_prealloc_list, pa_group_list) {
4887 spin_lock(&pa->pa_lock);
4888 if (atomic_read(&pa->pa_count)) {
4889 spin_unlock(&pa->pa_lock);
4893 if (pa->pa_deleted) {
4894 spin_unlock(&pa->pa_lock);
4898 /* seems this one can be freed ... */
4899 ext4_mb_mark_pa_deleted(sb, pa);
4902 this_cpu_inc(discard_pa_seq);
4904 /* we can trust pa_free ... */
4905 free += pa->pa_free;
4907 spin_unlock(&pa->pa_lock);
4909 list_del(&pa->pa_group_list);
4910 list_add(&pa->u.pa_tmp_list, &list);
4913 /* now free all selected PAs */
4914 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4916 /* remove from object (inode or locality group) */
4917 spin_lock(pa->pa_obj_lock);
4918 list_del_rcu(&pa->pa_inode_list);
4919 spin_unlock(pa->pa_obj_lock);
4921 if (pa->pa_type == MB_GROUP_PA)
4922 ext4_mb_release_group_pa(&e4b, pa);
4924 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4926 list_del(&pa->u.pa_tmp_list);
4927 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4930 ext4_unlock_group(sb, group);
4931 ext4_mb_unload_buddy(&e4b);
4934 mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
4935 free, group, grp->bb_free);
4940 * releases all non-used preallocated blocks for given inode
4942 * It's important to discard preallocations under i_data_sem
4943 * We don't want another block to be served from the prealloc
4944 * space when we are discarding the inode prealloc space.
4946 * FIXME!! Make sure it is valid at all the call sites
4948 void ext4_discard_preallocations(struct inode *inode, unsigned int needed)
4950 struct ext4_inode_info *ei = EXT4_I(inode);
4951 struct super_block *sb = inode->i_sb;
4952 struct buffer_head *bitmap_bh = NULL;
4953 struct ext4_prealloc_space *pa, *tmp;
4954 ext4_group_t group = 0;
4955 struct list_head list;
4956 struct ext4_buddy e4b;
4959 if (!S_ISREG(inode->i_mode)) {
4960 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
4964 if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
4967 mb_debug(sb, "discard preallocation for inode %lu\n",
4969 trace_ext4_discard_preallocations(inode,
4970 atomic_read(&ei->i_prealloc_active), needed);
4972 INIT_LIST_HEAD(&list);
4978 /* first, collect all pa's in the inode */
4979 spin_lock(&ei->i_prealloc_lock);
4980 while (!list_empty(&ei->i_prealloc_list) && needed) {
4981 pa = list_entry(ei->i_prealloc_list.prev,
4982 struct ext4_prealloc_space, pa_inode_list);
4983 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
4984 spin_lock(&pa->pa_lock);
4985 if (atomic_read(&pa->pa_count)) {
4986 /* this shouldn't happen often - nobody should
4987 * use preallocation while we're discarding it */
4988 spin_unlock(&pa->pa_lock);
4989 spin_unlock(&ei->i_prealloc_lock);
4990 ext4_msg(sb, KERN_ERR,
4991 "uh-oh! used pa while discarding");
4993 schedule_timeout_uninterruptible(HZ);
4997 if (pa->pa_deleted == 0) {
4998 ext4_mb_mark_pa_deleted(sb, pa);
4999 spin_unlock(&pa->pa_lock);
5000 list_del_rcu(&pa->pa_inode_list);
5001 list_add(&pa->u.pa_tmp_list, &list);
5006 /* someone is deleting pa right now */
5007 spin_unlock(&pa->pa_lock);
5008 spin_unlock(&ei->i_prealloc_lock);
5010 /* we have to wait here because pa_deleted
5011 * doesn't mean pa is already unlinked from
5012 * the list. as we might be called from
5013 * ->clear_inode() the inode will get freed
5014 * and concurrent thread which is unlinking
5015 * pa from inode's list may access already
5016 * freed memory, bad-bad-bad */
5018 /* XXX: if this happens too often, we can
5019 * add a flag to force wait only in case
5020 * of ->clear_inode(), but not in case of
5021 * regular truncate */
5022 schedule_timeout_uninterruptible(HZ);
5025 spin_unlock(&ei->i_prealloc_lock);
5027 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
5028 BUG_ON(pa->pa_type != MB_INODE_PA);
5029 group = ext4_get_group_number(sb, pa->pa_pstart);
5031 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
5032 GFP_NOFS|__GFP_NOFAIL);
5034 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5039 bitmap_bh = ext4_read_block_bitmap(sb, group);
5040 if (IS_ERR(bitmap_bh)) {
5041 err = PTR_ERR(bitmap_bh);
5042 ext4_error_err(sb, -err, "Error %d reading block bitmap for %u",
5044 ext4_mb_unload_buddy(&e4b);
5048 ext4_lock_group(sb, group);
5049 list_del(&pa->pa_group_list);
5050 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
5051 ext4_unlock_group(sb, group);
5053 ext4_mb_unload_buddy(&e4b);
5056 list_del(&pa->u.pa_tmp_list);
5057 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
5061 static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac)
5063 struct ext4_prealloc_space *pa;
5065 BUG_ON(ext4_pspace_cachep == NULL);
5066 pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS);
5069 atomic_set(&pa->pa_count, 1);
5074 static void ext4_mb_pa_free(struct ext4_allocation_context *ac)
5076 struct ext4_prealloc_space *pa = ac->ac_pa;
5080 WARN_ON(!atomic_dec_and_test(&pa->pa_count));
5081 kmem_cache_free(ext4_pspace_cachep, pa);
5084 #ifdef CONFIG_EXT4_DEBUG
5085 static inline void ext4_mb_show_pa(struct super_block *sb)
5087 ext4_group_t i, ngroups;
5089 if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5092 ngroups = ext4_get_groups_count(sb);
5093 mb_debug(sb, "groups: ");
5094 for (i = 0; i < ngroups; i++) {
5095 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
5096 struct ext4_prealloc_space *pa;
5097 ext4_grpblk_t start;
5098 struct list_head *cur;
5099 ext4_lock_group(sb, i);
5100 list_for_each(cur, &grp->bb_prealloc_list) {
5101 pa = list_entry(cur, struct ext4_prealloc_space,
5103 spin_lock(&pa->pa_lock);
5104 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
5106 spin_unlock(&pa->pa_lock);
5107 mb_debug(sb, "PA:%u:%d:%d\n", i, start,
5110 ext4_unlock_group(sb, i);
5111 mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free,
5116 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5118 struct super_block *sb = ac->ac_sb;
5120 if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
5123 mb_debug(sb, "Can't allocate:"
5124 " Allocation context details:");
5125 mb_debug(sb, "status %u flags 0x%x",
5126 ac->ac_status, ac->ac_flags);
5127 mb_debug(sb, "orig %lu/%lu/%lu@%lu, "
5128 "goal %lu/%lu/%lu@%lu, "
5129 "best %lu/%lu/%lu@%lu cr %d",
5130 (unsigned long)ac->ac_o_ex.fe_group,
5131 (unsigned long)ac->ac_o_ex.fe_start,
5132 (unsigned long)ac->ac_o_ex.fe_len,
5133 (unsigned long)ac->ac_o_ex.fe_logical,
5134 (unsigned long)ac->ac_g_ex.fe_group,
5135 (unsigned long)ac->ac_g_ex.fe_start,
5136 (unsigned long)ac->ac_g_ex.fe_len,
5137 (unsigned long)ac->ac_g_ex.fe_logical,
5138 (unsigned long)ac->ac_b_ex.fe_group,
5139 (unsigned long)ac->ac_b_ex.fe_start,
5140 (unsigned long)ac->ac_b_ex.fe_len,
5141 (unsigned long)ac->ac_b_ex.fe_logical,
5142 (int)ac->ac_criteria);
5143 mb_debug(sb, "%u found", ac->ac_found);
5144 ext4_mb_show_pa(sb);
5147 static inline void ext4_mb_show_pa(struct super_block *sb)
5151 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5153 ext4_mb_show_pa(ac->ac_sb);
5159 * We use locality group preallocation for small size file. The size of the
5160 * file is determined by the current size or the resulting size after
5161 * allocation which ever is larger
5163 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
5165 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
5167 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
5168 int bsbits = ac->ac_sb->s_blocksize_bits;
5171 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
5174 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
5177 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
5178 isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
5181 if ((size == isize) && !ext4_fs_is_busy(sbi) &&
5182 !inode_is_open_for_write(ac->ac_inode)) {
5183 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
5187 if (sbi->s_mb_group_prealloc <= 0) {
5188 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
5192 /* don't use group allocation for large files */
5193 size = max(size, isize);
5194 if (size > sbi->s_mb_stream_request) {
5195 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
5199 BUG_ON(ac->ac_lg != NULL);
5201 * locality group prealloc space are per cpu. The reason for having
5202 * per cpu locality group is to reduce the contention between block
5203 * request from multiple CPUs.
5205 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
5207 /* we're going to use group allocation */
5208 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
5210 /* serialize all allocations in the group */
5211 mutex_lock(&ac->ac_lg->lg_mutex);
5214 static noinline_for_stack int
5215 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
5216 struct ext4_allocation_request *ar)
5218 struct super_block *sb = ar->inode->i_sb;
5219 struct ext4_sb_info *sbi = EXT4_SB(sb);
5220 struct ext4_super_block *es = sbi->s_es;
5224 ext4_grpblk_t block;
5226 /* we can't allocate > group size */
5229 /* just a dirty hack to filter too big requests */
5230 if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
5231 len = EXT4_CLUSTERS_PER_GROUP(sb);
5233 /* start searching from the goal */
5235 if (goal < le32_to_cpu(es->s_first_data_block) ||
5236 goal >= ext4_blocks_count(es))
5237 goal = le32_to_cpu(es->s_first_data_block);
5238 ext4_get_group_no_and_offset(sb, goal, &group, &block);
5240 /* set up allocation goals */
5241 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
5242 ac->ac_status = AC_STATUS_CONTINUE;
5244 ac->ac_inode = ar->inode;
5245 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
5246 ac->ac_o_ex.fe_group = group;
5247 ac->ac_o_ex.fe_start = block;
5248 ac->ac_o_ex.fe_len = len;
5249 ac->ac_g_ex = ac->ac_o_ex;
5250 ac->ac_flags = ar->flags;
5252 /* we have to define context: we'll work with a file or
5253 * locality group. this is a policy, actually */
5254 ext4_mb_group_or_file(ac);
5256 mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, "
5257 "left: %u/%u, right %u/%u to %swritable\n",
5258 (unsigned) ar->len, (unsigned) ar->logical,
5259 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
5260 (unsigned) ar->lleft, (unsigned) ar->pleft,
5261 (unsigned) ar->lright, (unsigned) ar->pright,
5262 inode_is_open_for_write(ar->inode) ? "" : "non-");
5267 static noinline_for_stack void
5268 ext4_mb_discard_lg_preallocations(struct super_block *sb,
5269 struct ext4_locality_group *lg,
5270 int order, int total_entries)
5272 ext4_group_t group = 0;
5273 struct ext4_buddy e4b;
5274 struct list_head discard_list;
5275 struct ext4_prealloc_space *pa, *tmp;
5277 mb_debug(sb, "discard locality group preallocation\n");
5279 INIT_LIST_HEAD(&discard_list);
5281 spin_lock(&lg->lg_prealloc_lock);
5282 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
5284 lockdep_is_held(&lg->lg_prealloc_lock)) {
5285 spin_lock(&pa->pa_lock);
5286 if (atomic_read(&pa->pa_count)) {
5288 * This is the pa that we just used
5289 * for block allocation. So don't
5292 spin_unlock(&pa->pa_lock);
5295 if (pa->pa_deleted) {
5296 spin_unlock(&pa->pa_lock);
5299 /* only lg prealloc space */
5300 BUG_ON(pa->pa_type != MB_GROUP_PA);
5302 /* seems this one can be freed ... */
5303 ext4_mb_mark_pa_deleted(sb, pa);
5304 spin_unlock(&pa->pa_lock);
5306 list_del_rcu(&pa->pa_inode_list);
5307 list_add(&pa->u.pa_tmp_list, &discard_list);
5310 if (total_entries <= 5) {
5312 * we want to keep only 5 entries
5313 * allowing it to grow to 8. This
5314 * mak sure we don't call discard
5315 * soon for this list.
5320 spin_unlock(&lg->lg_prealloc_lock);
5322 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
5325 group = ext4_get_group_number(sb, pa->pa_pstart);
5326 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
5327 GFP_NOFS|__GFP_NOFAIL);
5329 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5333 ext4_lock_group(sb, group);
5334 list_del(&pa->pa_group_list);
5335 ext4_mb_release_group_pa(&e4b, pa);
5336 ext4_unlock_group(sb, group);
5338 ext4_mb_unload_buddy(&e4b);
5339 list_del(&pa->u.pa_tmp_list);
5340 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
5345 * We have incremented pa_count. So it cannot be freed at this
5346 * point. Also we hold lg_mutex. So no parallel allocation is
5347 * possible from this lg. That means pa_free cannot be updated.
5349 * A parallel ext4_mb_discard_group_preallocations is possible.
5350 * which can cause the lg_prealloc_list to be updated.
5353 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
5355 int order, added = 0, lg_prealloc_count = 1;
5356 struct super_block *sb = ac->ac_sb;
5357 struct ext4_locality_group *lg = ac->ac_lg;
5358 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
5360 order = fls(pa->pa_free) - 1;
5361 if (order > PREALLOC_TB_SIZE - 1)
5362 /* The max size of hash table is PREALLOC_TB_SIZE */
5363 order = PREALLOC_TB_SIZE - 1;
5364 /* Add the prealloc space to lg */
5365 spin_lock(&lg->lg_prealloc_lock);
5366 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
5368 lockdep_is_held(&lg->lg_prealloc_lock)) {
5369 spin_lock(&tmp_pa->pa_lock);
5370 if (tmp_pa->pa_deleted) {
5371 spin_unlock(&tmp_pa->pa_lock);
5374 if (!added && pa->pa_free < tmp_pa->pa_free) {
5375 /* Add to the tail of the previous entry */
5376 list_add_tail_rcu(&pa->pa_inode_list,
5377 &tmp_pa->pa_inode_list);
5380 * we want to count the total
5381 * number of entries in the list
5384 spin_unlock(&tmp_pa->pa_lock);
5385 lg_prealloc_count++;
5388 list_add_tail_rcu(&pa->pa_inode_list,
5389 &lg->lg_prealloc_list[order]);
5390 spin_unlock(&lg->lg_prealloc_lock);
5392 /* Now trim the list to be not more than 8 elements */
5393 if (lg_prealloc_count > 8) {
5394 ext4_mb_discard_lg_preallocations(sb, lg,
5395 order, lg_prealloc_count);
5402 * if per-inode prealloc list is too long, trim some PA
5404 static void ext4_mb_trim_inode_pa(struct inode *inode)
5406 struct ext4_inode_info *ei = EXT4_I(inode);
5407 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5410 count = atomic_read(&ei->i_prealloc_active);
5411 delta = (sbi->s_mb_max_inode_prealloc >> 2) + 1;
5412 if (count > sbi->s_mb_max_inode_prealloc + delta) {
5413 count -= sbi->s_mb_max_inode_prealloc;
5414 ext4_discard_preallocations(inode, count);
5419 * release all resource we used in allocation
5421 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
5423 struct inode *inode = ac->ac_inode;
5424 struct ext4_inode_info *ei = EXT4_I(inode);
5425 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
5426 struct ext4_prealloc_space *pa = ac->ac_pa;
5428 if (pa->pa_type == MB_GROUP_PA) {
5429 /* see comment in ext4_mb_use_group_pa() */
5430 spin_lock(&pa->pa_lock);
5431 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
5432 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
5433 pa->pa_free -= ac->ac_b_ex.fe_len;
5434 pa->pa_len -= ac->ac_b_ex.fe_len;
5435 spin_unlock(&pa->pa_lock);
5438 * We want to add the pa to the right bucket.
5439 * Remove it from the list and while adding
5440 * make sure the list to which we are adding
5443 if (likely(pa->pa_free)) {
5444 spin_lock(pa->pa_obj_lock);
5445 list_del_rcu(&pa->pa_inode_list);
5446 spin_unlock(pa->pa_obj_lock);
5447 ext4_mb_add_n_trim(ac);
5451 if (pa->pa_type == MB_INODE_PA) {
5453 * treat per-inode prealloc list as a lru list, then try
5454 * to trim the least recently used PA.
5456 spin_lock(pa->pa_obj_lock);
5457 list_move(&pa->pa_inode_list, &ei->i_prealloc_list);
5458 spin_unlock(pa->pa_obj_lock);
5461 ext4_mb_put_pa(ac, ac->ac_sb, pa);
5463 if (ac->ac_bitmap_page)
5464 put_page(ac->ac_bitmap_page);
5465 if (ac->ac_buddy_page)
5466 put_page(ac->ac_buddy_page);
5467 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
5468 mutex_unlock(&ac->ac_lg->lg_mutex);
5469 ext4_mb_collect_stats(ac);
5470 ext4_mb_trim_inode_pa(inode);
5474 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
5476 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
5478 int freed = 0, busy = 0;
5481 trace_ext4_mb_discard_preallocations(sb, needed);
5484 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
5486 for (i = 0; i < ngroups && needed > 0; i++) {
5487 ret = ext4_mb_discard_group_preallocations(sb, i, &busy);
5493 if (needed > 0 && busy && ++retry < 3) {
5501 static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb,
5502 struct ext4_allocation_context *ac, u64 *seq)
5508 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
5513 seq_retry = ext4_get_discard_pa_seq_sum();
5514 if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) {
5515 ac->ac_flags |= EXT4_MB_STRICT_CHECK;
5521 mb_debug(sb, "freed %d, retry ? %s\n", freed, ret ? "yes" : "no");
5525 static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle,
5526 struct ext4_allocation_request *ar, int *errp);
5529 * Main entry point into mballoc to allocate blocks
5530 * it tries to use preallocation first, then falls back
5531 * to usual allocation
5533 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
5534 struct ext4_allocation_request *ar, int *errp)
5536 struct ext4_allocation_context *ac = NULL;
5537 struct ext4_sb_info *sbi;
5538 struct super_block *sb;
5539 ext4_fsblk_t block = 0;
5540 unsigned int inquota = 0;
5541 unsigned int reserv_clstrs = 0;
5545 sb = ar->inode->i_sb;
5548 trace_ext4_request_blocks(ar);
5549 if (sbi->s_mount_state & EXT4_FC_REPLAY)
5550 return ext4_mb_new_blocks_simple(handle, ar, errp);
5552 /* Allow to use superuser reservation for quota file */
5553 if (ext4_is_quota_file(ar->inode))
5554 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
5556 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
5557 /* Without delayed allocation we need to verify
5558 * there is enough free blocks to do block allocation
5559 * and verify allocation doesn't exceed the quota limits.
5562 ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
5564 /* let others to free the space */
5566 ar->len = ar->len >> 1;
5569 ext4_mb_show_pa(sb);
5573 reserv_clstrs = ar->len;
5574 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
5575 dquot_alloc_block_nofail(ar->inode,
5576 EXT4_C2B(sbi, ar->len));
5579 dquot_alloc_block(ar->inode,
5580 EXT4_C2B(sbi, ar->len))) {
5582 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
5593 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
5600 *errp = ext4_mb_initialize_context(ac, ar);
5606 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
5607 seq = this_cpu_read(discard_pa_seq);
5608 if (!ext4_mb_use_preallocated(ac)) {
5609 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
5610 ext4_mb_normalize_request(ac, ar);
5612 *errp = ext4_mb_pa_alloc(ac);
5616 /* allocate space in core */
5617 *errp = ext4_mb_regular_allocator(ac);
5619 * pa allocated above is added to grp->bb_prealloc_list only
5620 * when we were able to allocate some block i.e. when
5621 * ac->ac_status == AC_STATUS_FOUND.
5622 * And error from above mean ac->ac_status != AC_STATUS_FOUND
5623 * So we have to free this pa here itself.
5626 ext4_mb_pa_free(ac);
5627 ext4_discard_allocated_blocks(ac);
5630 if (ac->ac_status == AC_STATUS_FOUND &&
5631 ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len)
5632 ext4_mb_pa_free(ac);
5634 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
5635 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
5637 ext4_discard_allocated_blocks(ac);
5640 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
5641 ar->len = ac->ac_b_ex.fe_len;
5644 if (ext4_mb_discard_preallocations_should_retry(sb, ac, &seq))
5647 * If block allocation fails then the pa allocated above
5648 * needs to be freed here itself.
5650 ext4_mb_pa_free(ac);
5656 ac->ac_b_ex.fe_len = 0;
5658 ext4_mb_show_ac(ac);
5660 ext4_mb_release_context(ac);
5663 kmem_cache_free(ext4_ac_cachep, ac);
5664 if (inquota && ar->len < inquota)
5665 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
5667 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
5668 /* release all the reserved blocks if non delalloc */
5669 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
5673 trace_ext4_allocate_blocks(ar, (unsigned long long)block);
5679 * We can merge two free data extents only if the physical blocks
5680 * are contiguous, AND the extents were freed by the same transaction,
5681 * AND the blocks are associated with the same group.
5683 static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
5684 struct ext4_free_data *entry,
5685 struct ext4_free_data *new_entry,
5686 struct rb_root *entry_rb_root)
5688 if ((entry->efd_tid != new_entry->efd_tid) ||
5689 (entry->efd_group != new_entry->efd_group))
5691 if (entry->efd_start_cluster + entry->efd_count ==
5692 new_entry->efd_start_cluster) {
5693 new_entry->efd_start_cluster = entry->efd_start_cluster;
5694 new_entry->efd_count += entry->efd_count;
5695 } else if (new_entry->efd_start_cluster + new_entry->efd_count ==
5696 entry->efd_start_cluster) {
5697 new_entry->efd_count += entry->efd_count;
5700 spin_lock(&sbi->s_md_lock);
5701 list_del(&entry->efd_list);
5702 spin_unlock(&sbi->s_md_lock);
5703 rb_erase(&entry->efd_node, entry_rb_root);
5704 kmem_cache_free(ext4_free_data_cachep, entry);
5707 static noinline_for_stack int
5708 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
5709 struct ext4_free_data *new_entry)
5711 ext4_group_t group = e4b->bd_group;
5712 ext4_grpblk_t cluster;
5713 ext4_grpblk_t clusters = new_entry->efd_count;
5714 struct ext4_free_data *entry;
5715 struct ext4_group_info *db = e4b->bd_info;
5716 struct super_block *sb = e4b->bd_sb;
5717 struct ext4_sb_info *sbi = EXT4_SB(sb);
5718 struct rb_node **n = &db->bb_free_root.rb_node, *node;
5719 struct rb_node *parent = NULL, *new_node;
5721 BUG_ON(!ext4_handle_valid(handle));
5722 BUG_ON(e4b->bd_bitmap_page == NULL);
5723 BUG_ON(e4b->bd_buddy_page == NULL);
5725 new_node = &new_entry->efd_node;
5726 cluster = new_entry->efd_start_cluster;
5729 /* first free block exent. We need to
5730 protect buddy cache from being freed,
5731 * otherwise we'll refresh it from
5732 * on-disk bitmap and lose not-yet-available
5734 get_page(e4b->bd_buddy_page);
5735 get_page(e4b->bd_bitmap_page);
5739 entry = rb_entry(parent, struct ext4_free_data, efd_node);
5740 if (cluster < entry->efd_start_cluster)
5742 else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
5743 n = &(*n)->rb_right;
5745 ext4_grp_locked_error(sb, group, 0,
5746 ext4_group_first_block_no(sb, group) +
5747 EXT4_C2B(sbi, cluster),
5748 "Block already on to-be-freed list");
5749 kmem_cache_free(ext4_free_data_cachep, new_entry);
5754 rb_link_node(new_node, parent, n);
5755 rb_insert_color(new_node, &db->bb_free_root);
5757 /* Now try to see the extent can be merged to left and right */
5758 node = rb_prev(new_node);
5760 entry = rb_entry(node, struct ext4_free_data, efd_node);
5761 ext4_try_merge_freed_extent(sbi, entry, new_entry,
5762 &(db->bb_free_root));
5765 node = rb_next(new_node);
5767 entry = rb_entry(node, struct ext4_free_data, efd_node);
5768 ext4_try_merge_freed_extent(sbi, entry, new_entry,
5769 &(db->bb_free_root));
5772 spin_lock(&sbi->s_md_lock);
5773 list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list);
5774 sbi->s_mb_free_pending += clusters;
5775 spin_unlock(&sbi->s_md_lock);
5780 * Simple allocator for Ext4 fast commit replay path. It searches for blocks
5781 * linearly starting at the goal block and also excludes the blocks which
5782 * are going to be in use after fast commit replay.
5784 static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle,
5785 struct ext4_allocation_request *ar, int *errp)
5787 struct buffer_head *bitmap_bh;
5788 struct super_block *sb = ar->inode->i_sb;
5790 ext4_grpblk_t blkoff;
5791 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
5792 ext4_grpblk_t i = 0;
5793 ext4_fsblk_t goal, block;
5794 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5797 if (goal < le32_to_cpu(es->s_first_data_block) ||
5798 goal >= ext4_blocks_count(es))
5799 goal = le32_to_cpu(es->s_first_data_block);
5802 ext4_get_group_no_and_offset(sb, goal, &group, &blkoff);
5803 for (; group < ext4_get_groups_count(sb); group++) {
5804 bitmap_bh = ext4_read_block_bitmap(sb, group);
5805 if (IS_ERR(bitmap_bh)) {
5806 *errp = PTR_ERR(bitmap_bh);
5807 pr_warn("Failed to read block bitmap\n");
5811 ext4_get_group_no_and_offset(sb,
5812 max(ext4_group_first_block_no(sb, group), goal),
5815 i = mb_find_next_zero_bit(bitmap_bh->b_data, max,
5819 if (ext4_fc_replay_check_excluded(sb,
5820 ext4_group_first_block_no(sb, group) + i)) {
5830 if (group >= ext4_get_groups_count(sb) || i >= max) {
5835 block = ext4_group_first_block_no(sb, group) + i;
5836 ext4_mb_mark_bb(sb, block, 1, 1);
5842 static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
5843 unsigned long count)
5845 struct buffer_head *bitmap_bh;
5846 struct super_block *sb = inode->i_sb;
5847 struct ext4_group_desc *gdp;
5848 struct buffer_head *gdp_bh;
5850 ext4_grpblk_t blkoff;
5851 int already_freed = 0, err, i;
5853 ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
5854 bitmap_bh = ext4_read_block_bitmap(sb, group);
5855 if (IS_ERR(bitmap_bh)) {
5856 err = PTR_ERR(bitmap_bh);
5857 pr_warn("Failed to read block bitmap\n");
5860 gdp = ext4_get_group_desc(sb, group, &gdp_bh);
5864 for (i = 0; i < count; i++) {
5865 if (!mb_test_bit(blkoff + i, bitmap_bh->b_data))
5868 mb_clear_bits(bitmap_bh->b_data, blkoff, count);
5869 err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh);
5872 ext4_free_group_clusters_set(
5873 sb, gdp, ext4_free_group_clusters(sb, gdp) +
5874 count - already_freed);
5875 ext4_block_bitmap_csum_set(sb, group, gdp, bitmap_bh);
5876 ext4_group_desc_csum_set(sb, group, gdp);
5877 ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
5878 sync_dirty_buffer(bitmap_bh);
5879 sync_dirty_buffer(gdp_bh);
5884 * ext4_free_blocks() -- Free given blocks and update quota
5885 * @handle: handle for this transaction
5887 * @bh: optional buffer of the block to be freed
5888 * @block: starting physical block to be freed
5889 * @count: number of blocks to be freed
5890 * @flags: flags used by ext4_free_blocks
5892 void ext4_free_blocks(handle_t *handle, struct inode *inode,
5893 struct buffer_head *bh, ext4_fsblk_t block,
5894 unsigned long count, int flags)
5896 struct buffer_head *bitmap_bh = NULL;
5897 struct super_block *sb = inode->i_sb;
5898 struct ext4_group_desc *gdp;
5899 unsigned int overflow;
5901 struct buffer_head *gd_bh;
5902 ext4_group_t block_group;
5903 struct ext4_sb_info *sbi;
5904 struct ext4_buddy e4b;
5905 unsigned int count_clusters;
5911 if (sbi->s_mount_state & EXT4_FC_REPLAY) {
5912 ext4_free_blocks_simple(inode, block, count);
5919 BUG_ON(block != bh->b_blocknr);
5921 block = bh->b_blocknr;
5924 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
5925 !ext4_inode_block_valid(inode, block, count)) {
5926 ext4_error(sb, "Freeing blocks not in datazone - "
5927 "block = %llu, count = %lu", block, count);
5931 ext4_debug("freeing block %llu\n", block);
5932 trace_ext4_free_blocks(inode, block, count, flags);
5934 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
5937 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
5942 * If the extent to be freed does not begin on a cluster
5943 * boundary, we need to deal with partial clusters at the
5944 * beginning and end of the extent. Normally we will free
5945 * blocks at the beginning or the end unless we are explicitly
5946 * requested to avoid doing so.
5948 overflow = EXT4_PBLK_COFF(sbi, block);
5950 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
5951 overflow = sbi->s_cluster_ratio - overflow;
5953 if (count > overflow)
5962 overflow = EXT4_LBLK_COFF(sbi, count);
5964 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
5965 if (count > overflow)
5970 count += sbi->s_cluster_ratio - overflow;
5973 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
5975 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
5977 for (i = 0; i < count; i++) {
5980 bh = sb_find_get_block(inode->i_sb, block + i);
5981 ext4_forget(handle, is_metadata, inode, bh, block + i);
5987 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
5989 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
5990 ext4_get_group_info(sb, block_group))))
5994 * Check to see if we are freeing blocks across a group
5997 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
5998 overflow = EXT4_C2B(sbi, bit) + count -
5999 EXT4_BLOCKS_PER_GROUP(sb);
6002 count_clusters = EXT4_NUM_B2C(sbi, count);
6003 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
6004 if (IS_ERR(bitmap_bh)) {
6005 err = PTR_ERR(bitmap_bh);
6009 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
6015 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
6016 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
6017 in_range(block, ext4_inode_table(sb, gdp),
6018 sbi->s_itb_per_group) ||
6019 in_range(block + count - 1, ext4_inode_table(sb, gdp),
6020 sbi->s_itb_per_group)) {
6022 ext4_error(sb, "Freeing blocks in system zone - "
6023 "Block = %llu, count = %lu", block, count);
6024 /* err = 0. ext4_std_error should be a no op */
6028 BUFFER_TRACE(bitmap_bh, "getting write access");
6029 err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
6035 * We are about to modify some metadata. Call the journal APIs
6036 * to unshare ->b_data if a currently-committing transaction is
6039 BUFFER_TRACE(gd_bh, "get_write_access");
6040 err = ext4_journal_get_write_access(handle, sb, gd_bh, EXT4_JTR_NONE);
6043 #ifdef AGGRESSIVE_CHECK
6046 for (i = 0; i < count_clusters; i++)
6047 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
6050 trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters);
6052 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
6053 err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b,
6054 GFP_NOFS|__GFP_NOFAIL);
6059 * We need to make sure we don't reuse the freed block until after the
6060 * transaction is committed. We make an exception if the inode is to be
6061 * written in writeback mode since writeback mode has weak data
6062 * consistency guarantees.
6064 if (ext4_handle_valid(handle) &&
6065 ((flags & EXT4_FREE_BLOCKS_METADATA) ||
6066 !ext4_should_writeback_data(inode))) {
6067 struct ext4_free_data *new_entry;
6069 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
6072 new_entry = kmem_cache_alloc(ext4_free_data_cachep,
6073 GFP_NOFS|__GFP_NOFAIL);
6074 new_entry->efd_start_cluster = bit;
6075 new_entry->efd_group = block_group;
6076 new_entry->efd_count = count_clusters;
6077 new_entry->efd_tid = handle->h_transaction->t_tid;
6079 ext4_lock_group(sb, block_group);
6080 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
6081 ext4_mb_free_metadata(handle, &e4b, new_entry);
6083 /* need to update group_info->bb_free and bitmap
6084 * with group lock held. generate_buddy look at
6085 * them with group lock_held
6087 if (test_opt(sb, DISCARD)) {
6088 err = ext4_issue_discard(sb, block_group, bit, count,
6090 if (err && err != -EOPNOTSUPP)
6091 ext4_msg(sb, KERN_WARNING, "discard request in"
6092 " group:%d block:%d count:%lu failed"
6093 " with %d", block_group, bit, count,
6096 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
6098 ext4_lock_group(sb, block_group);
6099 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
6100 mb_free_blocks(inode, &e4b, bit, count_clusters);
6103 ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
6104 ext4_free_group_clusters_set(sb, gdp, ret);
6105 ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
6106 ext4_group_desc_csum_set(sb, block_group, gdp);
6107 ext4_unlock_group(sb, block_group);
6109 if (sbi->s_log_groups_per_flex) {
6110 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
6111 atomic64_add(count_clusters,
6112 &sbi_array_rcu_deref(sbi, s_flex_groups,
6113 flex_group)->free_clusters);
6117 * on a bigalloc file system, defer the s_freeclusters_counter
6118 * update to the caller (ext4_remove_space and friends) so they
6119 * can determine if a cluster freed here should be rereserved
6121 if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
6122 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
6123 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
6124 percpu_counter_add(&sbi->s_freeclusters_counter,
6128 ext4_mb_unload_buddy(&e4b);
6130 /* We dirtied the bitmap block */
6131 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
6132 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
6134 /* And the group descriptor block */
6135 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
6136 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
6140 if (overflow && !err) {
6148 ext4_std_error(sb, err);
6153 * ext4_group_add_blocks() -- Add given blocks to an existing group
6154 * @handle: handle to this transaction
6156 * @block: start physical block to add to the block group
6157 * @count: number of blocks to free
6159 * This marks the blocks as free in the bitmap and buddy.
6161 int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
6162 ext4_fsblk_t block, unsigned long count)
6164 struct buffer_head *bitmap_bh = NULL;
6165 struct buffer_head *gd_bh;
6166 ext4_group_t block_group;
6169 struct ext4_group_desc *desc;
6170 struct ext4_sb_info *sbi = EXT4_SB(sb);
6171 struct ext4_buddy e4b;
6172 int err = 0, ret, free_clusters_count;
6173 ext4_grpblk_t clusters_freed;
6174 ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
6175 ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
6176 unsigned long cluster_count = last_cluster - first_cluster + 1;
6178 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
6183 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
6185 * Check to see if we are freeing blocks across a group
6188 if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
6189 ext4_warning(sb, "too many blocks added to group %u",
6195 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
6196 if (IS_ERR(bitmap_bh)) {
6197 err = PTR_ERR(bitmap_bh);
6202 desc = ext4_get_group_desc(sb, block_group, &gd_bh);
6208 if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
6209 in_range(ext4_inode_bitmap(sb, desc), block, count) ||
6210 in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
6211 in_range(block + count - 1, ext4_inode_table(sb, desc),
6212 sbi->s_itb_per_group)) {
6213 ext4_error(sb, "Adding blocks in system zones - "
6214 "Block = %llu, count = %lu",
6220 BUFFER_TRACE(bitmap_bh, "getting write access");
6221 err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
6227 * We are about to modify some metadata. Call the journal APIs
6228 * to unshare ->b_data if a currently-committing transaction is
6231 BUFFER_TRACE(gd_bh, "get_write_access");
6232 err = ext4_journal_get_write_access(handle, sb, gd_bh, EXT4_JTR_NONE);
6236 for (i = 0, clusters_freed = 0; i < cluster_count; i++) {
6237 BUFFER_TRACE(bitmap_bh, "clear bit");
6238 if (!mb_test_bit(bit + i, bitmap_bh->b_data)) {
6239 ext4_error(sb, "bit already cleared for block %llu",
6240 (ext4_fsblk_t)(block + i));
6241 BUFFER_TRACE(bitmap_bh, "bit already cleared");
6247 err = ext4_mb_load_buddy(sb, block_group, &e4b);
6252 * need to update group_info->bb_free and bitmap
6253 * with group lock held. generate_buddy look at
6254 * them with group lock_held
6256 ext4_lock_group(sb, block_group);
6257 mb_clear_bits(bitmap_bh->b_data, bit, cluster_count);
6258 mb_free_blocks(NULL, &e4b, bit, cluster_count);
6259 free_clusters_count = clusters_freed +
6260 ext4_free_group_clusters(sb, desc);
6261 ext4_free_group_clusters_set(sb, desc, free_clusters_count);
6262 ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
6263 ext4_group_desc_csum_set(sb, block_group, desc);
6264 ext4_unlock_group(sb, block_group);
6265 percpu_counter_add(&sbi->s_freeclusters_counter,
6268 if (sbi->s_log_groups_per_flex) {
6269 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
6270 atomic64_add(clusters_freed,
6271 &sbi_array_rcu_deref(sbi, s_flex_groups,
6272 flex_group)->free_clusters);
6275 ext4_mb_unload_buddy(&e4b);
6277 /* We dirtied the bitmap block */
6278 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
6279 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
6281 /* And the group descriptor block */
6282 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
6283 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
6289 ext4_std_error(sb, err);
6294 * ext4_trim_extent -- function to TRIM one single free extent in the group
6295 * @sb: super block for the file system
6296 * @start: starting block of the free extent in the alloc. group
6297 * @count: number of blocks to TRIM
6298 * @e4b: ext4 buddy for the group
6300 * Trim "count" blocks starting at "start" in the "group". To assure that no
6301 * one will allocate those blocks, mark it as used in buddy bitmap. This must
6302 * be called with under the group lock.
6304 static int ext4_trim_extent(struct super_block *sb,
6305 int start, int count, struct ext4_buddy *e4b)
6309 struct ext4_free_extent ex;
6310 ext4_group_t group = e4b->bd_group;
6313 trace_ext4_trim_extent(sb, group, start, count);
6315 assert_spin_locked(ext4_group_lock_ptr(sb, group));
6317 ex.fe_start = start;
6318 ex.fe_group = group;
6322 * Mark blocks used, so no one can reuse them while
6325 mb_mark_used(e4b, &ex);
6326 ext4_unlock_group(sb, group);
6327 ret = ext4_issue_discard(sb, group, start, count, NULL);
6328 ext4_lock_group(sb, group);
6329 mb_free_blocks(NULL, e4b, start, ex.fe_len);
6333 static int ext4_try_to_trim_range(struct super_block *sb,
6334 struct ext4_buddy *e4b, ext4_grpblk_t start,
6335 ext4_grpblk_t max, ext4_grpblk_t minblocks)
6336 __acquires(ext4_group_lock_ptr(sb, e4b->bd_group))
6337 __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
6339 ext4_grpblk_t next, count, free_count;
6343 bitmap = e4b->bd_bitmap;
6344 start = (e4b->bd_info->bb_first_free > start) ?
6345 e4b->bd_info->bb_first_free : start;
6349 while (start <= max) {
6350 start = mb_find_next_zero_bit(bitmap, max + 1, start);
6353 next = mb_find_next_bit(bitmap, max + 1, start);
6355 if ((next - start) >= minblocks) {
6356 ret = ext4_trim_extent(sb, start, next - start, e4b);
6357 if (ret && ret != -EOPNOTSUPP)
6360 count += next - start;
6362 free_count += next - start;
6365 if (fatal_signal_pending(current)) {
6366 count = -ERESTARTSYS;
6370 if (need_resched()) {
6371 ext4_unlock_group(sb, e4b->bd_group);
6373 ext4_lock_group(sb, e4b->bd_group);
6376 if ((e4b->bd_info->bb_free - free_count) < minblocks)
6384 * ext4_trim_all_free -- function to trim all free space in alloc. group
6385 * @sb: super block for file system
6386 * @group: group to be trimmed
6387 * @start: first group block to examine
6388 * @max: last group block to examine
6389 * @minblocks: minimum extent block count
6390 * @set_trimmed: set the trimmed flag if at least one block is trimmed
6392 * ext4_trim_all_free walks through group's block bitmap searching for free
6393 * extents. When the free extent is found, mark it as used in group buddy
6394 * bitmap. Then issue a TRIM command on this extent and free the extent in
6395 * the group buddy bitmap.
6397 static ext4_grpblk_t
6398 ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
6399 ext4_grpblk_t start, ext4_grpblk_t max,
6400 ext4_grpblk_t minblocks, bool set_trimmed)
6402 struct ext4_buddy e4b;
6405 trace_ext4_trim_all_free(sb, group, start, max);
6407 ret = ext4_mb_load_buddy(sb, group, &e4b);
6409 ext4_warning(sb, "Error %d loading buddy information for %u",
6414 ext4_lock_group(sb, group);
6416 if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) ||
6417 minblocks < atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) {
6418 ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks);
6419 if (ret >= 0 && set_trimmed)
6420 EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
6425 ext4_unlock_group(sb, group);
6426 ext4_mb_unload_buddy(&e4b);
6428 ext4_debug("trimmed %d blocks in the group %d\n",
6435 * ext4_trim_fs() -- trim ioctl handle function
6436 * @sb: superblock for filesystem
6437 * @range: fstrim_range structure
6439 * start: First Byte to trim
6440 * len: number of Bytes to trim from start
6441 * minlen: minimum extent length in Bytes
6442 * ext4_trim_fs goes through all allocation groups containing Bytes from
6443 * start to start+len. For each such a group ext4_trim_all_free function
6444 * is invoked to trim all free space.
6446 int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
6448 struct request_queue *q = bdev_get_queue(sb->s_bdev);
6449 struct ext4_group_info *grp;
6450 ext4_group_t group, first_group, last_group;
6451 ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
6452 uint64_t start, end, minlen, trimmed = 0;
6453 ext4_fsblk_t first_data_blk =
6454 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
6455 ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es);
6456 bool whole_group, eof = false;
6459 start = range->start >> sb->s_blocksize_bits;
6460 end = start + (range->len >> sb->s_blocksize_bits) - 1;
6461 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
6462 range->minlen >> sb->s_blocksize_bits);
6464 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
6465 start >= max_blks ||
6466 range->len < sb->s_blocksize)
6468 /* No point to try to trim less than discard granularity */
6469 if (range->minlen < q->limits.discard_granularity) {
6470 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
6471 q->limits.discard_granularity >> sb->s_blocksize_bits);
6472 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb))
6475 if (end >= max_blks - 1) {
6479 if (end <= first_data_blk)
6481 if (start < first_data_blk)
6482 start = first_data_blk;
6484 /* Determine first and last group to examine based on start and end */
6485 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,
6486 &first_group, &first_cluster);
6487 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end,
6488 &last_group, &last_cluster);
6490 /* end now represents the last cluster to discard in this group */
6491 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
6494 for (group = first_group; group <= last_group; group++) {
6495 grp = ext4_get_group_info(sb, group);
6496 /* We only do this if the grp has never been initialized */
6497 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
6498 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
6504 * For all the groups except the last one, last cluster will
6505 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
6506 * change it for the last group, note that last_cluster is
6507 * already computed earlier by ext4_get_group_no_and_offset()
6509 if (group == last_group) {
6511 whole_group = eof ? true : end == EXT4_CLUSTERS_PER_GROUP(sb) - 1;
6513 if (grp->bb_free >= minlen) {
6514 cnt = ext4_trim_all_free(sb, group, first_cluster,
6515 end, minlen, whole_group);
6524 * For every group except the first one, we are sure
6525 * that the first cluster to discard will be cluster #0.
6531 atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
6534 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
6538 /* Iterate all the free extents in the group. */
6540 ext4_mballoc_query_range(
6541 struct super_block *sb,
6543 ext4_grpblk_t start,
6545 ext4_mballoc_query_range_fn formatter,
6550 struct ext4_buddy e4b;
6553 error = ext4_mb_load_buddy(sb, group, &e4b);
6556 bitmap = e4b.bd_bitmap;
6558 ext4_lock_group(sb, group);
6560 start = (e4b.bd_info->bb_first_free > start) ?
6561 e4b.bd_info->bb_first_free : start;
6562 if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
6563 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
6565 while (start <= end) {
6566 start = mb_find_next_zero_bit(bitmap, end + 1, start);
6569 next = mb_find_next_bit(bitmap, end + 1, start);
6571 ext4_unlock_group(sb, group);
6572 error = formatter(sb, group, start, next - start, priv);
6575 ext4_lock_group(sb, group);
6580 ext4_unlock_group(sb, group);
6582 ext4_mb_unload_buddy(&e4b);