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 * The regular allocator (using the buddy cache) supports a few tunables.
132 * /sys/fs/ext4/<partition>/mb_min_to_scan
133 * /sys/fs/ext4/<partition>/mb_max_to_scan
134 * /sys/fs/ext4/<partition>/mb_order2_req
136 * The regular allocator uses buddy scan only if the request len is power of
137 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
138 * value of s_mb_order2_reqs can be tuned via
139 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
140 * stripe size (sbi->s_stripe), we try to search for contiguous block in
141 * stripe size. This should result in better allocation on RAID setups. If
142 * not, we search in the specific group using bitmap for best extents. The
143 * tunable min_to_scan and max_to_scan control the behaviour here.
144 * min_to_scan indicate how long the mballoc __must__ look for a best
145 * extent and max_to_scan indicates how long the mballoc __can__ look for a
146 * best extent in the found extents. Searching for the blocks starts with
147 * the group specified as the goal value in allocation context via
148 * ac_g_ex. Each group is first checked based on the criteria whether it
149 * can be used for allocation. ext4_mb_good_group explains how the groups are
152 * Both the prealloc space are getting populated as above. So for the first
153 * request we will hit the buddy cache which will result in this prealloc
154 * space getting filled. The prealloc space is then later used for the
155 * subsequent request.
159 * mballoc operates on the following data:
161 * - in-core buddy (actually includes buddy and bitmap)
162 * - preallocation descriptors (PAs)
164 * there are two types of preallocations:
166 * assiged to specific inode and can be used for this inode only.
167 * it describes part of inode's space preallocated to specific
168 * physical blocks. any block from that preallocated can be used
169 * independent. the descriptor just tracks number of blocks left
170 * unused. so, before taking some block from descriptor, one must
171 * make sure corresponded logical block isn't allocated yet. this
172 * also means that freeing any block within descriptor's range
173 * must discard all preallocated blocks.
175 * assigned to specific locality group which does not translate to
176 * permanent set of inodes: inode can join and leave group. space
177 * from this type of preallocation can be used for any inode. thus
178 * it's consumed from the beginning to the end.
180 * relation between them can be expressed as:
181 * in-core buddy = on-disk bitmap + preallocation descriptors
183 * this mean blocks mballoc considers used are:
184 * - allocated blocks (persistent)
185 * - preallocated blocks (non-persistent)
187 * consistency in mballoc world means that at any time a block is either
188 * free or used in ALL structures. notice: "any time" should not be read
189 * literally -- time is discrete and delimited by locks.
191 * to keep it simple, we don't use block numbers, instead we count number of
192 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
194 * all operations can be expressed as:
195 * - init buddy: buddy = on-disk + PAs
196 * - new PA: buddy += N; PA = N
197 * - use inode PA: on-disk += N; PA -= N
198 * - discard inode PA buddy -= on-disk - PA; PA = 0
199 * - use locality group PA on-disk += N; PA -= N
200 * - discard locality group PA buddy -= PA; PA = 0
201 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
202 * is used in real operation because we can't know actual used
203 * bits from PA, only from on-disk bitmap
205 * if we follow this strict logic, then all operations above should be atomic.
206 * given some of them can block, we'd have to use something like semaphores
207 * killing performance on high-end SMP hardware. let's try to relax it using
208 * the following knowledge:
209 * 1) if buddy is referenced, it's already initialized
210 * 2) while block is used in buddy and the buddy is referenced,
211 * nobody can re-allocate that block
212 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
213 * bit set and PA claims same block, it's OK. IOW, one can set bit in
214 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
217 * so, now we're building a concurrency table:
220 * blocks for PA are allocated in the buddy, buddy must be referenced
221 * until PA is linked to allocation group to avoid concurrent buddy init
223 * we need to make sure that either on-disk bitmap or PA has uptodate data
224 * given (3) we care that PA-=N operation doesn't interfere with init
226 * the simplest way would be to have buddy initialized by the discard
227 * - use locality group PA
228 * again PA-=N must be serialized with init
229 * - discard locality group PA
230 * the simplest way would be to have buddy initialized by the discard
233 * i_data_sem serializes them
235 * discard process must wait until PA isn't used by another process
236 * - use locality group PA
237 * some mutex should serialize them
238 * - discard locality group PA
239 * discard process must wait until PA isn't used by another process
242 * i_data_sem or another mutex should serializes them
244 * discard process must wait until PA isn't used by another process
245 * - use locality group PA
246 * nothing wrong here -- they're different PAs covering different blocks
247 * - discard locality group PA
248 * discard process must wait until PA isn't used by another process
250 * now we're ready to make few consequences:
251 * - PA is referenced and while it is no discard is possible
252 * - PA is referenced until block isn't marked in on-disk bitmap
253 * - PA changes only after on-disk bitmap
254 * - discard must not compete with init. either init is done before
255 * any discard or they're serialized somehow
256 * - buddy init as sum of on-disk bitmap and PAs is done atomically
258 * a special case when we've used PA to emptiness. no need to modify buddy
259 * in this case, but we should care about concurrent init
264 * Logic in few words:
269 * mark bits in on-disk bitmap
272 * - use preallocation:
273 * find proper PA (per-inode or group)
275 * mark bits in on-disk bitmap
281 * mark bits in on-disk bitmap
284 * - discard preallocations in group:
286 * move them onto local list
287 * load on-disk bitmap
289 * remove PA from object (inode or locality group)
290 * mark free blocks in-core
292 * - discard inode's preallocations:
299 * - bitlock on a group (group)
300 * - object (inode/locality) (object)
311 * - release consumed pa:
316 * - generate in-core bitmap:
320 * - discard all for given object (inode, locality group):
325 * - discard all for given group:
332 static struct kmem_cache *ext4_pspace_cachep;
333 static struct kmem_cache *ext4_ac_cachep;
334 static struct kmem_cache *ext4_free_data_cachep;
336 /* We create slab caches for groupinfo data structures based on the
337 * superblock block size. There will be one per mounted filesystem for
338 * each unique s_blocksize_bits */
339 #define NR_GRPINFO_CACHES 8
340 static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
342 static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
343 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
344 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
345 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
348 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
350 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
352 static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
355 * The algorithm using this percpu seq counter goes below:
356 * 1. We sample the percpu discard_pa_seq counter before trying for block
357 * allocation in ext4_mb_new_blocks().
358 * 2. We increment this percpu discard_pa_seq counter when we either allocate
359 * or free these blocks i.e. while marking those blocks as used/free in
360 * mb_mark_used()/mb_free_blocks().
361 * 3. We also increment this percpu seq counter when we successfully identify
362 * that the bb_prealloc_list is not empty and hence proceed for discarding
363 * of those PAs inside ext4_mb_discard_group_preallocations().
365 * Now to make sure that the regular fast path of block allocation is not
366 * affected, as a small optimization we only sample the percpu seq counter
367 * on that cpu. Only when the block allocation fails and when freed blocks
368 * found were 0, that is when we sample percpu seq counter for all cpus using
369 * below function ext4_get_discard_pa_seq_sum(). This happens after making
370 * sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty.
372 static DEFINE_PER_CPU(u64, discard_pa_seq);
373 static inline u64 ext4_get_discard_pa_seq_sum(void)
378 for_each_possible_cpu(__cpu)
379 __seq += per_cpu(discard_pa_seq, __cpu);
383 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
385 #if BITS_PER_LONG == 64
386 *bit += ((unsigned long) addr & 7UL) << 3;
387 addr = (void *) ((unsigned long) addr & ~7UL);
388 #elif BITS_PER_LONG == 32
389 *bit += ((unsigned long) addr & 3UL) << 3;
390 addr = (void *) ((unsigned long) addr & ~3UL);
392 #error "how many bits you are?!"
397 static inline int mb_test_bit(int bit, void *addr)
400 * ext4_test_bit on architecture like powerpc
401 * needs unsigned long aligned address
403 addr = mb_correct_addr_and_bit(&bit, addr);
404 return ext4_test_bit(bit, addr);
407 static inline void mb_set_bit(int bit, void *addr)
409 addr = mb_correct_addr_and_bit(&bit, addr);
410 ext4_set_bit(bit, addr);
413 static inline void mb_clear_bit(int bit, void *addr)
415 addr = mb_correct_addr_and_bit(&bit, addr);
416 ext4_clear_bit(bit, addr);
419 static inline int mb_test_and_clear_bit(int bit, void *addr)
421 addr = mb_correct_addr_and_bit(&bit, addr);
422 return ext4_test_and_clear_bit(bit, addr);
425 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
427 int fix = 0, ret, tmpmax;
428 addr = mb_correct_addr_and_bit(&fix, addr);
432 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
438 static inline int mb_find_next_bit(void *addr, int max, int start)
440 int fix = 0, ret, tmpmax;
441 addr = mb_correct_addr_and_bit(&fix, addr);
445 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
451 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
455 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
458 if (order > e4b->bd_blkbits + 1) {
463 /* at order 0 we see each particular block */
465 *max = 1 << (e4b->bd_blkbits + 3);
466 return e4b->bd_bitmap;
469 bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
470 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
476 static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
477 int first, int count)
480 struct super_block *sb = e4b->bd_sb;
482 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
484 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
485 for (i = 0; i < count; i++) {
486 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
487 ext4_fsblk_t blocknr;
489 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
490 blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
491 ext4_grp_locked_error(sb, e4b->bd_group,
492 inode ? inode->i_ino : 0,
494 "freeing block already freed "
497 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
498 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
500 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
504 static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
508 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
510 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
511 for (i = 0; i < count; i++) {
512 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
513 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
517 static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
519 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
521 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
522 unsigned char *b1, *b2;
524 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
525 b2 = (unsigned char *) bitmap;
526 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
527 if (b1[i] != b2[i]) {
528 ext4_msg(e4b->bd_sb, KERN_ERR,
529 "corruption in group %u "
530 "at byte %u(%u): %x in copy != %x "
532 e4b->bd_group, i, i * 8, b1[i], b2[i]);
539 static void mb_group_bb_bitmap_alloc(struct super_block *sb,
540 struct ext4_group_info *grp, ext4_group_t group)
542 struct buffer_head *bh;
544 grp->bb_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS);
548 bh = ext4_read_block_bitmap(sb, group);
549 if (IS_ERR_OR_NULL(bh)) {
550 kfree(grp->bb_bitmap);
551 grp->bb_bitmap = NULL;
555 memcpy(grp->bb_bitmap, bh->b_data, sb->s_blocksize);
559 static void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
561 kfree(grp->bb_bitmap);
565 static inline void mb_free_blocks_double(struct inode *inode,
566 struct ext4_buddy *e4b, int first, int count)
570 static inline void mb_mark_used_double(struct ext4_buddy *e4b,
571 int first, int count)
575 static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
580 static inline void mb_group_bb_bitmap_alloc(struct super_block *sb,
581 struct ext4_group_info *grp, ext4_group_t group)
586 static inline void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
592 #ifdef AGGRESSIVE_CHECK
594 #define MB_CHECK_ASSERT(assert) \
598 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
599 function, file, line, # assert); \
604 static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
605 const char *function, int line)
607 struct super_block *sb = e4b->bd_sb;
608 int order = e4b->bd_blkbits + 1;
615 struct ext4_group_info *grp;
618 struct list_head *cur;
622 if (e4b->bd_info->bb_check_counter++ % 10)
626 buddy = mb_find_buddy(e4b, order, &max);
627 MB_CHECK_ASSERT(buddy);
628 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
629 MB_CHECK_ASSERT(buddy2);
630 MB_CHECK_ASSERT(buddy != buddy2);
631 MB_CHECK_ASSERT(max * 2 == max2);
634 for (i = 0; i < max; i++) {
636 if (mb_test_bit(i, buddy)) {
637 /* only single bit in buddy2 may be 1 */
638 if (!mb_test_bit(i << 1, buddy2)) {
640 mb_test_bit((i<<1)+1, buddy2));
641 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
643 mb_test_bit(i << 1, buddy2));
648 /* both bits in buddy2 must be 1 */
649 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
650 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
652 for (j = 0; j < (1 << order); j++) {
653 k = (i * (1 << order)) + j;
655 !mb_test_bit(k, e4b->bd_bitmap));
659 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
664 buddy = mb_find_buddy(e4b, 0, &max);
665 for (i = 0; i < max; i++) {
666 if (!mb_test_bit(i, buddy)) {
667 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
675 /* check used bits only */
676 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
677 buddy2 = mb_find_buddy(e4b, j, &max2);
679 MB_CHECK_ASSERT(k < max2);
680 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
683 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
684 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
686 grp = ext4_get_group_info(sb, e4b->bd_group);
687 list_for_each(cur, &grp->bb_prealloc_list) {
688 ext4_group_t groupnr;
689 struct ext4_prealloc_space *pa;
690 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
691 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
692 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
693 for (i = 0; i < pa->pa_len; i++)
694 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
698 #undef MB_CHECK_ASSERT
699 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
700 __FILE__, __func__, __LINE__)
702 #define mb_check_buddy(e4b)
706 * Divide blocks started from @first with length @len into
707 * smaller chunks with power of 2 blocks.
708 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
709 * then increase bb_counters[] for corresponded chunk size.
711 static void ext4_mb_mark_free_simple(struct super_block *sb,
712 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
713 struct ext4_group_info *grp)
715 struct ext4_sb_info *sbi = EXT4_SB(sb);
721 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
723 border = 2 << sb->s_blocksize_bits;
726 /* find how many blocks can be covered since this position */
727 max = ffs(first | border) - 1;
729 /* find how many blocks of power 2 we need to mark */
736 /* mark multiblock chunks only */
737 grp->bb_counters[min]++;
739 mb_clear_bit(first >> min,
740 buddy + sbi->s_mb_offsets[min]);
748 * Cache the order of the largest free extent we have available in this block
752 mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
757 grp->bb_largest_free_order = -1; /* uninit */
759 bits = sb->s_blocksize_bits + 1;
760 for (i = bits; i >= 0; i--) {
761 if (grp->bb_counters[i] > 0) {
762 grp->bb_largest_free_order = i;
768 static noinline_for_stack
769 void ext4_mb_generate_buddy(struct super_block *sb,
770 void *buddy, void *bitmap, ext4_group_t group)
772 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
773 struct ext4_sb_info *sbi = EXT4_SB(sb);
774 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
779 unsigned fragments = 0;
780 unsigned long long period = get_cycles();
782 /* initialize buddy from bitmap which is aggregation
783 * of on-disk bitmap and preallocations */
784 i = mb_find_next_zero_bit(bitmap, max, 0);
785 grp->bb_first_free = i;
789 i = mb_find_next_bit(bitmap, max, i);
793 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
795 grp->bb_counters[0]++;
797 i = mb_find_next_zero_bit(bitmap, max, i);
799 grp->bb_fragments = fragments;
801 if (free != grp->bb_free) {
802 ext4_grp_locked_error(sb, group, 0, 0,
803 "block bitmap and bg descriptor "
804 "inconsistent: %u vs %u free clusters",
807 * If we intend to continue, we consider group descriptor
808 * corrupt and update bb_free using bitmap value
811 ext4_mark_group_bitmap_corrupted(sb, group,
812 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
814 mb_set_largest_free_order(sb, grp);
816 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
818 period = get_cycles() - period;
819 spin_lock(&sbi->s_bal_lock);
820 sbi->s_mb_buddies_generated++;
821 sbi->s_mb_generation_time += period;
822 spin_unlock(&sbi->s_bal_lock);
825 static void mb_regenerate_buddy(struct ext4_buddy *e4b)
831 while ((buddy = mb_find_buddy(e4b, order++, &count))) {
832 ext4_set_bits(buddy, 0, count);
834 e4b->bd_info->bb_fragments = 0;
835 memset(e4b->bd_info->bb_counters, 0,
836 sizeof(*e4b->bd_info->bb_counters) *
837 (e4b->bd_sb->s_blocksize_bits + 2));
839 ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy,
840 e4b->bd_bitmap, e4b->bd_group);
843 /* The buddy information is attached the buddy cache inode
844 * for convenience. The information regarding each group
845 * is loaded via ext4_mb_load_buddy. The information involve
846 * block bitmap and buddy information. The information are
847 * stored in the inode as
850 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
853 * one block each for bitmap and buddy information.
854 * So for each group we take up 2 blocks. A page can
855 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
856 * So it can have information regarding groups_per_page which
857 * is blocks_per_page/2
859 * Locking note: This routine takes the block group lock of all groups
860 * for this page; do not hold this lock when calling this routine!
863 static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
865 ext4_group_t ngroups;
871 ext4_group_t first_group, group;
873 struct super_block *sb;
874 struct buffer_head *bhs;
875 struct buffer_head **bh = NULL;
879 struct ext4_group_info *grinfo;
881 inode = page->mapping->host;
883 ngroups = ext4_get_groups_count(sb);
884 blocksize = i_blocksize(inode);
885 blocks_per_page = PAGE_SIZE / blocksize;
887 mb_debug(sb, "init page %lu\n", page->index);
889 groups_per_page = blocks_per_page >> 1;
890 if (groups_per_page == 0)
893 /* allocate buffer_heads to read bitmaps */
894 if (groups_per_page > 1) {
895 i = sizeof(struct buffer_head *) * groups_per_page;
896 bh = kzalloc(i, gfp);
904 first_group = page->index * blocks_per_page / 2;
906 /* read all groups the page covers into the cache */
907 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
908 if (group >= ngroups)
911 grinfo = ext4_get_group_info(sb, group);
913 * If page is uptodate then we came here after online resize
914 * which added some new uninitialized group info structs, so
915 * we must skip all initialized uptodate buddies on the page,
916 * which may be currently in use by an allocating task.
918 if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
922 bh[i] = ext4_read_block_bitmap_nowait(sb, group, false);
924 err = PTR_ERR(bh[i]);
928 mb_debug(sb, "read bitmap for group %u\n", group);
931 /* wait for I/O completion */
932 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
937 err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
942 first_block = page->index * blocks_per_page;
943 for (i = 0; i < blocks_per_page; i++) {
944 group = (first_block + i) >> 1;
945 if (group >= ngroups)
948 if (!bh[group - first_group])
949 /* skip initialized uptodate buddy */
952 if (!buffer_verified(bh[group - first_group]))
953 /* Skip faulty bitmaps */
958 * data carry information regarding this
959 * particular group in the format specified
963 data = page_address(page) + (i * blocksize);
964 bitmap = bh[group - first_group]->b_data;
967 * We place the buddy block and bitmap block
970 if ((first_block + i) & 1) {
971 /* this is block of buddy */
972 BUG_ON(incore == NULL);
973 mb_debug(sb, "put buddy for group %u in page %lu/%x\n",
974 group, page->index, i * blocksize);
975 trace_ext4_mb_buddy_bitmap_load(sb, group);
976 grinfo = ext4_get_group_info(sb, group);
977 grinfo->bb_fragments = 0;
978 memset(grinfo->bb_counters, 0,
979 sizeof(*grinfo->bb_counters) *
980 (sb->s_blocksize_bits+2));
982 * incore got set to the group block bitmap below
984 ext4_lock_group(sb, group);
986 memset(data, 0xff, blocksize);
987 ext4_mb_generate_buddy(sb, data, incore, group);
988 ext4_unlock_group(sb, group);
991 /* this is block of bitmap */
992 BUG_ON(incore != NULL);
993 mb_debug(sb, "put bitmap for group %u in page %lu/%x\n",
994 group, page->index, i * blocksize);
995 trace_ext4_mb_bitmap_load(sb, group);
997 /* see comments in ext4_mb_put_pa() */
998 ext4_lock_group(sb, group);
999 memcpy(data, bitmap, blocksize);
1001 /* mark all preallocated blks used in in-core bitmap */
1002 ext4_mb_generate_from_pa(sb, data, group);
1003 ext4_mb_generate_from_freelist(sb, data, group);
1004 ext4_unlock_group(sb, group);
1006 /* set incore so that the buddy information can be
1007 * generated using this
1012 SetPageUptodate(page);
1016 for (i = 0; i < groups_per_page; i++)
1025 * Lock the buddy and bitmap pages. This make sure other parallel init_group
1026 * on the same buddy page doesn't happen whild holding the buddy page lock.
1027 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
1028 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
1030 static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
1031 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
1033 struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
1034 int block, pnum, poff;
1035 int blocks_per_page;
1038 e4b->bd_buddy_page = NULL;
1039 e4b->bd_bitmap_page = NULL;
1041 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1043 * the buddy cache inode stores the block bitmap
1044 * and buddy information in consecutive blocks.
1045 * So for each group we need two blocks.
1048 pnum = block / blocks_per_page;
1049 poff = block % blocks_per_page;
1050 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1053 BUG_ON(page->mapping != inode->i_mapping);
1054 e4b->bd_bitmap_page = page;
1055 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1057 if (blocks_per_page >= 2) {
1058 /* buddy and bitmap are on the same page */
1063 pnum = block / blocks_per_page;
1064 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1067 BUG_ON(page->mapping != inode->i_mapping);
1068 e4b->bd_buddy_page = page;
1072 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1074 if (e4b->bd_bitmap_page) {
1075 unlock_page(e4b->bd_bitmap_page);
1076 put_page(e4b->bd_bitmap_page);
1078 if (e4b->bd_buddy_page) {
1079 unlock_page(e4b->bd_buddy_page);
1080 put_page(e4b->bd_buddy_page);
1085 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1086 * block group lock of all groups for this page; do not hold the BG lock when
1087 * calling this routine!
1089 static noinline_for_stack
1090 int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1093 struct ext4_group_info *this_grp;
1094 struct ext4_buddy e4b;
1099 mb_debug(sb, "init group %u\n", group);
1100 this_grp = ext4_get_group_info(sb, group);
1102 * This ensures that we don't reinit the buddy cache
1103 * page which map to the group from which we are already
1104 * allocating. If we are looking at the buddy cache we would
1105 * have taken a reference using ext4_mb_load_buddy and that
1106 * would have pinned buddy page to page cache.
1107 * The call to ext4_mb_get_buddy_page_lock will mark the
1110 ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp);
1111 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1113 * somebody initialized the group
1114 * return without doing anything
1119 page = e4b.bd_bitmap_page;
1120 ret = ext4_mb_init_cache(page, NULL, gfp);
1123 if (!PageUptodate(page)) {
1128 if (e4b.bd_buddy_page == NULL) {
1130 * If both the bitmap and buddy are in
1131 * the same page we don't need to force
1137 /* init buddy cache */
1138 page = e4b.bd_buddy_page;
1139 ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp);
1142 if (!PageUptodate(page)) {
1147 ext4_mb_put_buddy_page_lock(&e4b);
1152 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1153 * block group lock of all groups for this page; do not hold the BG lock when
1154 * calling this routine!
1156 static noinline_for_stack int
1157 ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1158 struct ext4_buddy *e4b, gfp_t gfp)
1160 int blocks_per_page;
1166 struct ext4_group_info *grp;
1167 struct ext4_sb_info *sbi = EXT4_SB(sb);
1168 struct inode *inode = sbi->s_buddy_cache;
1171 mb_debug(sb, "load group %u\n", group);
1173 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1174 grp = ext4_get_group_info(sb, group);
1176 e4b->bd_blkbits = sb->s_blocksize_bits;
1179 e4b->bd_group = group;
1180 e4b->bd_buddy_page = NULL;
1181 e4b->bd_bitmap_page = NULL;
1183 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1185 * we need full data about the group
1186 * to make a good selection
1188 ret = ext4_mb_init_group(sb, group, gfp);
1194 * the buddy cache inode stores the block bitmap
1195 * and buddy information in consecutive blocks.
1196 * So for each group we need two blocks.
1199 pnum = block / blocks_per_page;
1200 poff = block % blocks_per_page;
1202 /* we could use find_or_create_page(), but it locks page
1203 * what we'd like to avoid in fast path ... */
1204 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1205 if (page == NULL || !PageUptodate(page)) {
1208 * drop the page reference and try
1209 * to get the page with lock. If we
1210 * are not uptodate that implies
1211 * somebody just created the page but
1212 * is yet to initialize the same. So
1213 * wait for it to initialize.
1216 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1218 BUG_ON(page->mapping != inode->i_mapping);
1219 if (!PageUptodate(page)) {
1220 ret = ext4_mb_init_cache(page, NULL, gfp);
1225 mb_cmp_bitmaps(e4b, page_address(page) +
1226 (poff * sb->s_blocksize));
1235 if (!PageUptodate(page)) {
1240 /* Pages marked accessed already */
1241 e4b->bd_bitmap_page = page;
1242 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1245 pnum = block / blocks_per_page;
1246 poff = block % blocks_per_page;
1248 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1249 if (page == NULL || !PageUptodate(page)) {
1252 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1254 BUG_ON(page->mapping != inode->i_mapping);
1255 if (!PageUptodate(page)) {
1256 ret = ext4_mb_init_cache(page, e4b->bd_bitmap,
1270 if (!PageUptodate(page)) {
1275 /* Pages marked accessed already */
1276 e4b->bd_buddy_page = page;
1277 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1284 if (e4b->bd_bitmap_page)
1285 put_page(e4b->bd_bitmap_page);
1286 if (e4b->bd_buddy_page)
1287 put_page(e4b->bd_buddy_page);
1288 e4b->bd_buddy = NULL;
1289 e4b->bd_bitmap = NULL;
1293 static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1294 struct ext4_buddy *e4b)
1296 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1299 static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1301 if (e4b->bd_bitmap_page)
1302 put_page(e4b->bd_bitmap_page);
1303 if (e4b->bd_buddy_page)
1304 put_page(e4b->bd_buddy_page);
1308 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1311 int bb_incr = 1 << (e4b->bd_blkbits - 1);
1314 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1315 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1318 while (order <= e4b->bd_blkbits + 1) {
1320 if (!mb_test_bit(block, bb)) {
1321 /* this block is part of buddy of order 'order' */
1331 static void mb_clear_bits(void *bm, int cur, int len)
1337 if ((cur & 31) == 0 && (len - cur) >= 32) {
1338 /* fast path: clear whole word at once */
1339 addr = bm + (cur >> 3);
1344 mb_clear_bit(cur, bm);
1349 /* clear bits in given range
1350 * will return first found zero bit if any, -1 otherwise
1352 static int mb_test_and_clear_bits(void *bm, int cur, int len)
1359 if ((cur & 31) == 0 && (len - cur) >= 32) {
1360 /* fast path: clear whole word at once */
1361 addr = bm + (cur >> 3);
1362 if (*addr != (__u32)(-1) && zero_bit == -1)
1363 zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0);
1368 if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1)
1376 void ext4_set_bits(void *bm, int cur, int len)
1382 if ((cur & 31) == 0 && (len - cur) >= 32) {
1383 /* fast path: set whole word at once */
1384 addr = bm + (cur >> 3);
1389 mb_set_bit(cur, bm);
1394 static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1396 if (mb_test_bit(*bit + side, bitmap)) {
1397 mb_clear_bit(*bit, bitmap);
1403 mb_set_bit(*bit, bitmap);
1408 static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1412 void *buddy = mb_find_buddy(e4b, order, &max);
1417 /* Bits in range [first; last] are known to be set since
1418 * corresponding blocks were allocated. Bits in range
1419 * (first; last) will stay set because they form buddies on
1420 * upper layer. We just deal with borders if they don't
1421 * align with upper layer and then go up.
1422 * Releasing entire group is all about clearing
1423 * single bit of highest order buddy.
1427 * ---------------------------------
1429 * ---------------------------------
1430 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1431 * ---------------------------------
1433 * \_____________________/
1435 * Neither [1] nor [6] is aligned to above layer.
1436 * Left neighbour [0] is free, so mark it busy,
1437 * decrease bb_counters and extend range to
1439 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1440 * mark [6] free, increase bb_counters and shrink range to
1442 * Then shift range to [0; 2], go up and do the same.
1447 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1);
1449 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1);
1454 if (first == last || !(buddy2 = mb_find_buddy(e4b, order, &max))) {
1455 mb_clear_bits(buddy, first, last - first + 1);
1456 e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1465 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1466 int first, int count)
1468 int left_is_free = 0;
1469 int right_is_free = 0;
1471 int last = first + count - 1;
1472 struct super_block *sb = e4b->bd_sb;
1474 if (WARN_ON(count == 0))
1476 BUG_ON(last >= (sb->s_blocksize << 3));
1477 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1478 /* Don't bother if the block group is corrupt. */
1479 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1482 mb_check_buddy(e4b);
1483 mb_free_blocks_double(inode, e4b, first, count);
1485 this_cpu_inc(discard_pa_seq);
1486 e4b->bd_info->bb_free += count;
1487 if (first < e4b->bd_info->bb_first_free)
1488 e4b->bd_info->bb_first_free = first;
1490 /* access memory sequentially: check left neighbour,
1491 * clear range and then check right neighbour
1494 left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap);
1495 block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count);
1496 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1497 right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap);
1499 if (unlikely(block != -1)) {
1500 struct ext4_sb_info *sbi = EXT4_SB(sb);
1501 ext4_fsblk_t blocknr;
1503 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
1504 blocknr += EXT4_C2B(sbi, block);
1505 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1506 ext4_grp_locked_error(sb, e4b->bd_group,
1507 inode ? inode->i_ino : 0,
1509 "freeing already freed block (bit %u); block bitmap corrupt.",
1511 ext4_mark_group_bitmap_corrupted(
1513 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1515 mb_regenerate_buddy(e4b);
1519 /* let's maintain fragments counter */
1520 if (left_is_free && right_is_free)
1521 e4b->bd_info->bb_fragments--;
1522 else if (!left_is_free && !right_is_free)
1523 e4b->bd_info->bb_fragments++;
1525 /* buddy[0] == bd_bitmap is a special case, so handle
1526 * it right away and let mb_buddy_mark_free stay free of
1527 * zero order checks.
1528 * Check if neighbours are to be coaleasced,
1529 * adjust bitmap bb_counters and borders appropriately.
1532 first += !left_is_free;
1533 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
1536 last -= !right_is_free;
1537 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
1541 mb_buddy_mark_free(e4b, first >> 1, last >> 1);
1544 mb_set_largest_free_order(sb, e4b->bd_info);
1545 mb_check_buddy(e4b);
1548 static int mb_find_extent(struct ext4_buddy *e4b, int block,
1549 int needed, struct ext4_free_extent *ex)
1555 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1558 buddy = mb_find_buddy(e4b, 0, &max);
1559 BUG_ON(buddy == NULL);
1560 BUG_ON(block >= max);
1561 if (mb_test_bit(block, buddy)) {
1568 /* find actual order */
1569 order = mb_find_order_for_block(e4b, block);
1570 block = block >> order;
1572 ex->fe_len = 1 << order;
1573 ex->fe_start = block << order;
1574 ex->fe_group = e4b->bd_group;
1576 /* calc difference from given start */
1577 next = next - ex->fe_start;
1579 ex->fe_start += next;
1581 while (needed > ex->fe_len &&
1582 mb_find_buddy(e4b, order, &max)) {
1584 if (block + 1 >= max)
1587 next = (block + 1) * (1 << order);
1588 if (mb_test_bit(next, e4b->bd_bitmap))
1591 order = mb_find_order_for_block(e4b, next);
1593 block = next >> order;
1594 ex->fe_len += 1 << order;
1597 if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
1598 /* Should never happen! (but apparently sometimes does?!?) */
1600 ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0,
1601 "corruption or bug in mb_find_extent "
1602 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
1603 block, order, needed, ex->fe_group, ex->fe_start,
1604 ex->fe_len, ex->fe_logical);
1612 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1618 int start = ex->fe_start;
1619 int len = ex->fe_len;
1624 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1625 BUG_ON(e4b->bd_group != ex->fe_group);
1626 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1627 mb_check_buddy(e4b);
1628 mb_mark_used_double(e4b, start, len);
1630 this_cpu_inc(discard_pa_seq);
1631 e4b->bd_info->bb_free -= len;
1632 if (e4b->bd_info->bb_first_free == start)
1633 e4b->bd_info->bb_first_free += len;
1635 /* let's maintain fragments counter */
1637 mlen = !mb_test_bit(start - 1, e4b->bd_bitmap);
1638 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1639 max = !mb_test_bit(start + len, e4b->bd_bitmap);
1641 e4b->bd_info->bb_fragments++;
1642 else if (!mlen && !max)
1643 e4b->bd_info->bb_fragments--;
1645 /* let's maintain buddy itself */
1647 ord = mb_find_order_for_block(e4b, start);
1649 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1650 /* the whole chunk may be allocated at once! */
1652 buddy = mb_find_buddy(e4b, ord, &max);
1653 BUG_ON((start >> ord) >= max);
1654 mb_set_bit(start >> ord, buddy);
1655 e4b->bd_info->bb_counters[ord]--;
1662 /* store for history */
1664 ret = len | (ord << 16);
1666 /* we have to split large buddy */
1668 buddy = mb_find_buddy(e4b, ord, &max);
1669 mb_set_bit(start >> ord, buddy);
1670 e4b->bd_info->bb_counters[ord]--;
1673 cur = (start >> ord) & ~1U;
1674 buddy = mb_find_buddy(e4b, ord, &max);
1675 mb_clear_bit(cur, buddy);
1676 mb_clear_bit(cur + 1, buddy);
1677 e4b->bd_info->bb_counters[ord]++;
1678 e4b->bd_info->bb_counters[ord]++;
1680 mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
1682 ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
1683 mb_check_buddy(e4b);
1689 * Must be called under group lock!
1691 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1692 struct ext4_buddy *e4b)
1694 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1697 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1698 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1700 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1701 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1702 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1704 /* preallocation can change ac_b_ex, thus we store actually
1705 * allocated blocks for history */
1706 ac->ac_f_ex = ac->ac_b_ex;
1708 ac->ac_status = AC_STATUS_FOUND;
1709 ac->ac_tail = ret & 0xffff;
1710 ac->ac_buddy = ret >> 16;
1713 * take the page reference. We want the page to be pinned
1714 * so that we don't get a ext4_mb_init_cache_call for this
1715 * group until we update the bitmap. That would mean we
1716 * double allocate blocks. The reference is dropped
1717 * in ext4_mb_release_context
1719 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1720 get_page(ac->ac_bitmap_page);
1721 ac->ac_buddy_page = e4b->bd_buddy_page;
1722 get_page(ac->ac_buddy_page);
1723 /* store last allocated for subsequent stream allocation */
1724 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
1725 spin_lock(&sbi->s_md_lock);
1726 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1727 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1728 spin_unlock(&sbi->s_md_lock);
1731 * As we've just preallocated more space than
1732 * user requested originally, we store allocated
1733 * space in a special descriptor.
1735 if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
1736 ext4_mb_new_preallocation(ac);
1740 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1741 struct ext4_buddy *e4b,
1744 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1745 struct ext4_free_extent *bex = &ac->ac_b_ex;
1746 struct ext4_free_extent *gex = &ac->ac_g_ex;
1747 struct ext4_free_extent ex;
1750 if (ac->ac_status == AC_STATUS_FOUND)
1753 * We don't want to scan for a whole year
1755 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1756 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1757 ac->ac_status = AC_STATUS_BREAK;
1762 * Haven't found good chunk so far, let's continue
1764 if (bex->fe_len < gex->fe_len)
1767 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1768 && bex->fe_group == e4b->bd_group) {
1769 /* recheck chunk's availability - we don't know
1770 * when it was found (within this lock-unlock
1772 max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex);
1773 if (max >= gex->fe_len) {
1774 ext4_mb_use_best_found(ac, e4b);
1781 * The routine checks whether found extent is good enough. If it is,
1782 * then the extent gets marked used and flag is set to the context
1783 * to stop scanning. Otherwise, the extent is compared with the
1784 * previous found extent and if new one is better, then it's stored
1785 * in the context. Later, the best found extent will be used, if
1786 * mballoc can't find good enough extent.
1788 * FIXME: real allocation policy is to be designed yet!
1790 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1791 struct ext4_free_extent *ex,
1792 struct ext4_buddy *e4b)
1794 struct ext4_free_extent *bex = &ac->ac_b_ex;
1795 struct ext4_free_extent *gex = &ac->ac_g_ex;
1797 BUG_ON(ex->fe_len <= 0);
1798 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1799 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1800 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1805 * The special case - take what you catch first
1807 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1809 ext4_mb_use_best_found(ac, e4b);
1814 * Let's check whether the chuck is good enough
1816 if (ex->fe_len == gex->fe_len) {
1818 ext4_mb_use_best_found(ac, e4b);
1823 * If this is first found extent, just store it in the context
1825 if (bex->fe_len == 0) {
1831 * If new found extent is better, store it in the context
1833 if (bex->fe_len < gex->fe_len) {
1834 /* if the request isn't satisfied, any found extent
1835 * larger than previous best one is better */
1836 if (ex->fe_len > bex->fe_len)
1838 } else if (ex->fe_len > gex->fe_len) {
1839 /* if the request is satisfied, then we try to find
1840 * an extent that still satisfy the request, but is
1841 * smaller than previous one */
1842 if (ex->fe_len < bex->fe_len)
1846 ext4_mb_check_limits(ac, e4b, 0);
1849 static noinline_for_stack
1850 int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1851 struct ext4_buddy *e4b)
1853 struct ext4_free_extent ex = ac->ac_b_ex;
1854 ext4_group_t group = ex.fe_group;
1858 BUG_ON(ex.fe_len <= 0);
1859 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1863 ext4_lock_group(ac->ac_sb, group);
1864 max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex);
1868 ext4_mb_use_best_found(ac, e4b);
1871 ext4_unlock_group(ac->ac_sb, group);
1872 ext4_mb_unload_buddy(e4b);
1877 static noinline_for_stack
1878 int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1879 struct ext4_buddy *e4b)
1881 ext4_group_t group = ac->ac_g_ex.fe_group;
1884 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1885 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1886 struct ext4_free_extent ex;
1888 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1890 if (grp->bb_free == 0)
1893 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1897 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) {
1898 ext4_mb_unload_buddy(e4b);
1902 ext4_lock_group(ac->ac_sb, group);
1903 max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
1904 ac->ac_g_ex.fe_len, &ex);
1905 ex.fe_logical = 0xDEADFA11; /* debug value */
1907 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1910 start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) +
1912 /* use do_div to get remainder (would be 64-bit modulo) */
1913 if (do_div(start, sbi->s_stripe) == 0) {
1916 ext4_mb_use_best_found(ac, e4b);
1918 } else if (max >= ac->ac_g_ex.fe_len) {
1919 BUG_ON(ex.fe_len <= 0);
1920 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1921 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1924 ext4_mb_use_best_found(ac, e4b);
1925 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1926 /* Sometimes, caller may want to merge even small
1927 * number of blocks to an existing extent */
1928 BUG_ON(ex.fe_len <= 0);
1929 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1930 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1933 ext4_mb_use_best_found(ac, e4b);
1935 ext4_unlock_group(ac->ac_sb, group);
1936 ext4_mb_unload_buddy(e4b);
1942 * The routine scans buddy structures (not bitmap!) from given order
1943 * to max order and tries to find big enough chunk to satisfy the req
1945 static noinline_for_stack
1946 void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1947 struct ext4_buddy *e4b)
1949 struct super_block *sb = ac->ac_sb;
1950 struct ext4_group_info *grp = e4b->bd_info;
1956 BUG_ON(ac->ac_2order <= 0);
1957 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1958 if (grp->bb_counters[i] == 0)
1961 buddy = mb_find_buddy(e4b, i, &max);
1962 BUG_ON(buddy == NULL);
1964 k = mb_find_next_zero_bit(buddy, max, 0);
1966 ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0,
1967 "%d free clusters of order %d. But found 0",
1968 grp->bb_counters[i], i);
1969 ext4_mark_group_bitmap_corrupted(ac->ac_sb,
1971 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1976 ac->ac_b_ex.fe_len = 1 << i;
1977 ac->ac_b_ex.fe_start = k << i;
1978 ac->ac_b_ex.fe_group = e4b->bd_group;
1980 ext4_mb_use_best_found(ac, e4b);
1982 BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len);
1984 if (EXT4_SB(sb)->s_mb_stats)
1985 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1992 * The routine scans the group and measures all found extents.
1993 * In order to optimize scanning, caller must pass number of
1994 * free blocks in the group, so the routine can know upper limit.
1996 static noinline_for_stack
1997 void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1998 struct ext4_buddy *e4b)
2000 struct super_block *sb = ac->ac_sb;
2001 void *bitmap = e4b->bd_bitmap;
2002 struct ext4_free_extent ex;
2006 free = e4b->bd_info->bb_free;
2007 if (WARN_ON(free <= 0))
2010 i = e4b->bd_info->bb_first_free;
2012 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
2013 i = mb_find_next_zero_bit(bitmap,
2014 EXT4_CLUSTERS_PER_GROUP(sb), i);
2015 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
2017 * IF we have corrupt bitmap, we won't find any
2018 * free blocks even though group info says we
2021 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2022 "%d free clusters as per "
2023 "group info. But bitmap says 0",
2025 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
2026 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2030 mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex);
2031 if (WARN_ON(ex.fe_len <= 0))
2033 if (free < ex.fe_len) {
2034 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2035 "%d free clusters as per "
2036 "group info. But got %d blocks",
2038 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
2039 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2041 * The number of free blocks differs. This mostly
2042 * indicate that the bitmap is corrupt. So exit
2043 * without claiming the space.
2047 ex.fe_logical = 0xDEADC0DE; /* debug value */
2048 ext4_mb_measure_extent(ac, &ex, e4b);
2054 ext4_mb_check_limits(ac, e4b, 1);
2058 * This is a special case for storages like raid5
2059 * we try to find stripe-aligned chunks for stripe-size-multiple requests
2061 static noinline_for_stack
2062 void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
2063 struct ext4_buddy *e4b)
2065 struct super_block *sb = ac->ac_sb;
2066 struct ext4_sb_info *sbi = EXT4_SB(sb);
2067 void *bitmap = e4b->bd_bitmap;
2068 struct ext4_free_extent ex;
2069 ext4_fsblk_t first_group_block;
2074 BUG_ON(sbi->s_stripe == 0);
2076 /* find first stripe-aligned block in group */
2077 first_group_block = ext4_group_first_block_no(sb, e4b->bd_group);
2079 a = first_group_block + sbi->s_stripe - 1;
2080 do_div(a, sbi->s_stripe);
2081 i = (a * sbi->s_stripe) - first_group_block;
2083 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2084 if (!mb_test_bit(i, bitmap)) {
2085 max = mb_find_extent(e4b, i, sbi->s_stripe, &ex);
2086 if (max >= sbi->s_stripe) {
2088 ex.fe_logical = 0xDEADF00D; /* debug value */
2090 ext4_mb_use_best_found(ac, e4b);
2099 * This is also called BEFORE we load the buddy bitmap.
2100 * Returns either 1 or 0 indicating that the group is either suitable
2101 * for the allocation or not.
2103 static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
2104 ext4_group_t group, int cr)
2106 ext4_grpblk_t free, fragments;
2107 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
2108 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2110 BUG_ON(cr < 0 || cr >= 4);
2112 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2115 free = grp->bb_free;
2119 fragments = grp->bb_fragments;
2125 BUG_ON(ac->ac_2order == 0);
2127 /* Avoid using the first bg of a flexgroup for data files */
2128 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2129 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2130 ((group % flex_size) == 0))
2133 if (free < ac->ac_g_ex.fe_len)
2136 if (ac->ac_2order > ac->ac_sb->s_blocksize_bits+1)
2139 if (grp->bb_largest_free_order < ac->ac_2order)
2144 if ((free / fragments) >= ac->ac_g_ex.fe_len)
2148 if (free >= ac->ac_g_ex.fe_len)
2161 * This could return negative error code if something goes wrong
2162 * during ext4_mb_init_group(). This should not be called with
2163 * ext4_lock_group() held.
2165 static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac,
2166 ext4_group_t group, int cr)
2168 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2169 struct super_block *sb = ac->ac_sb;
2170 struct ext4_sb_info *sbi = EXT4_SB(sb);
2171 bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK;
2176 ext4_lock_group(sb, group);
2177 free = grp->bb_free;
2180 if (cr <= 2 && free < ac->ac_g_ex.fe_len)
2182 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2185 ext4_unlock_group(sb, group);
2187 /* We only do this if the grp has never been initialized */
2188 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2189 struct ext4_group_desc *gdp =
2190 ext4_get_group_desc(sb, group, NULL);
2193 /* cr=0/1 is a very optimistic search to find large
2194 * good chunks almost for free. If buddy data is not
2195 * ready, then this optimization makes no sense. But
2196 * we never skip the first block group in a flex_bg,
2197 * since this gets used for metadata block allocation,
2198 * and we want to make sure we locate metadata blocks
2199 * in the first block group in the flex_bg if possible.
2202 (!sbi->s_log_groups_per_flex ||
2203 ((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) &&
2204 !(ext4_has_group_desc_csum(sb) &&
2205 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))))
2207 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
2213 ext4_lock_group(sb, group);
2214 ret = ext4_mb_good_group(ac, group, cr);
2217 ext4_unlock_group(sb, group);
2222 * Start prefetching @nr block bitmaps starting at @group.
2223 * Return the next group which needs to be prefetched.
2225 ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group,
2226 unsigned int nr, int *cnt)
2228 ext4_group_t ngroups = ext4_get_groups_count(sb);
2229 struct buffer_head *bh;
2230 struct blk_plug plug;
2232 blk_start_plug(&plug);
2234 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group,
2236 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
2239 * Prefetch block groups with free blocks; but don't
2240 * bother if it is marked uninitialized on disk, since
2241 * it won't require I/O to read. Also only try to
2242 * prefetch once, so we avoid getblk() call, which can
2245 if (!EXT4_MB_GRP_TEST_AND_SET_READ(grp) &&
2246 EXT4_MB_GRP_NEED_INIT(grp) &&
2247 ext4_free_group_clusters(sb, gdp) > 0 &&
2248 !(ext4_has_group_desc_csum(sb) &&
2249 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) {
2250 bh = ext4_read_block_bitmap_nowait(sb, group, true);
2251 if (bh && !IS_ERR(bh)) {
2252 if (!buffer_uptodate(bh) && cnt)
2257 if (++group >= ngroups)
2260 blk_finish_plug(&plug);
2265 * Prefetching reads the block bitmap into the buffer cache; but we
2266 * need to make sure that the buddy bitmap in the page cache has been
2267 * initialized. Note that ext4_mb_init_group() will block if the I/O
2268 * is not yet completed, or indeed if it was not initiated by
2269 * ext4_mb_prefetch did not start the I/O.
2271 * TODO: We should actually kick off the buddy bitmap setup in a work
2272 * queue when the buffer I/O is completed, so that we don't block
2273 * waiting for the block allocation bitmap read to finish when
2274 * ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator().
2276 void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
2280 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group,
2282 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
2285 group = ext4_get_groups_count(sb);
2287 grp = ext4_get_group_info(sb, group);
2289 if (EXT4_MB_GRP_NEED_INIT(grp) &&
2290 ext4_free_group_clusters(sb, gdp) > 0 &&
2291 !(ext4_has_group_desc_csum(sb) &&
2292 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) {
2293 if (ext4_mb_init_group(sb, group, GFP_NOFS))
2299 static noinline_for_stack int
2300 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2302 ext4_group_t prefetch_grp = 0, ngroups, group, i;
2304 int err = 0, first_err = 0;
2305 unsigned int nr = 0, prefetch_ios = 0;
2306 struct ext4_sb_info *sbi;
2307 struct super_block *sb;
2308 struct ext4_buddy e4b;
2313 ngroups = ext4_get_groups_count(sb);
2314 /* non-extent files are limited to low blocks/groups */
2315 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)))
2316 ngroups = sbi->s_blockfile_groups;
2318 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2320 /* first, try the goal */
2321 err = ext4_mb_find_by_goal(ac, &e4b);
2322 if (err || ac->ac_status == AC_STATUS_FOUND)
2325 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2329 * ac->ac_2order is set only if the fe_len is a power of 2
2330 * if ac->ac_2order is set we also set criteria to 0 so that we
2331 * try exact allocation using buddy.
2333 i = fls(ac->ac_g_ex.fe_len);
2336 * We search using buddy data only if the order of the request
2337 * is greater than equal to the sbi_s_mb_order2_reqs
2338 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2339 * We also support searching for power-of-two requests only for
2340 * requests upto maximum buddy size we have constructed.
2342 if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
2344 * This should tell if fe_len is exactly power of 2
2346 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
2347 ac->ac_2order = array_index_nospec(i - 1,
2348 sb->s_blocksize_bits + 2);
2351 /* if stream allocation is enabled, use global goal */
2352 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2353 /* TBD: may be hot point */
2354 spin_lock(&sbi->s_md_lock);
2355 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2356 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2357 spin_unlock(&sbi->s_md_lock);
2360 /* Let's just scan groups to find more-less suitable blocks */
2361 cr = ac->ac_2order ? 0 : 1;
2363 * cr == 0 try to get exact allocation,
2364 * cr == 3 try to get anything
2367 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2368 ac->ac_criteria = cr;
2370 * searching for the right group start
2371 * from the goal value specified
2373 group = ac->ac_g_ex.fe_group;
2374 prefetch_grp = group;
2376 for (i = 0; i < ngroups; group++, i++) {
2380 * Artificially restricted ngroups for non-extent
2381 * files makes group > ngroups possible on first loop.
2383 if (group >= ngroups)
2387 * Batch reads of the block allocation bitmaps
2388 * to get multiple READs in flight; limit
2389 * prefetching at cr=0/1, otherwise mballoc can
2390 * spend a lot of time loading imperfect groups
2392 if ((prefetch_grp == group) &&
2394 prefetch_ios < sbi->s_mb_prefetch_limit)) {
2395 unsigned int curr_ios = prefetch_ios;
2397 nr = sbi->s_mb_prefetch;
2398 if (ext4_has_feature_flex_bg(sb)) {
2399 nr = 1 << sbi->s_log_groups_per_flex;
2400 nr -= group & (nr - 1);
2401 nr = min(nr, sbi->s_mb_prefetch);
2403 prefetch_grp = ext4_mb_prefetch(sb, group,
2405 if (prefetch_ios == curr_ios)
2409 /* This now checks without needing the buddy page */
2410 ret = ext4_mb_good_group_nolock(ac, group, cr);
2417 err = ext4_mb_load_buddy(sb, group, &e4b);
2421 ext4_lock_group(sb, group);
2424 * We need to check again after locking the
2427 ret = ext4_mb_good_group(ac, group, cr);
2429 ext4_unlock_group(sb, group);
2430 ext4_mb_unload_buddy(&e4b);
2434 ac->ac_groups_scanned++;
2436 ext4_mb_simple_scan_group(ac, &e4b);
2437 else if (cr == 1 && sbi->s_stripe &&
2438 !(ac->ac_g_ex.fe_len % sbi->s_stripe))
2439 ext4_mb_scan_aligned(ac, &e4b);
2441 ext4_mb_complex_scan_group(ac, &e4b);
2443 ext4_unlock_group(sb, group);
2444 ext4_mb_unload_buddy(&e4b);
2446 if (ac->ac_status != AC_STATUS_CONTINUE)
2451 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2452 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2454 * We've been searching too long. Let's try to allocate
2455 * the best chunk we've found so far
2457 ext4_mb_try_best_found(ac, &e4b);
2458 if (ac->ac_status != AC_STATUS_FOUND) {
2460 * Someone more lucky has already allocated it.
2461 * The only thing we can do is just take first
2464 lost = atomic_inc_return(&sbi->s_mb_lost_chunks);
2465 mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n",
2466 ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start,
2467 ac->ac_b_ex.fe_len, lost);
2469 ac->ac_b_ex.fe_group = 0;
2470 ac->ac_b_ex.fe_start = 0;
2471 ac->ac_b_ex.fe_len = 0;
2472 ac->ac_status = AC_STATUS_CONTINUE;
2473 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2479 if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
2482 mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
2483 ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status,
2484 ac->ac_flags, cr, err);
2487 ext4_mb_prefetch_fini(sb, prefetch_grp, nr);
2492 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2494 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2497 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2500 return (void *) ((unsigned long) group);
2503 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2505 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2509 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2512 return (void *) ((unsigned long) group);
2515 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2517 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2518 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
2520 int err, buddy_loaded = 0;
2521 struct ext4_buddy e4b;
2522 struct ext4_group_info *grinfo;
2523 unsigned char blocksize_bits = min_t(unsigned char,
2524 sb->s_blocksize_bits,
2525 EXT4_MAX_BLOCK_LOG_SIZE);
2527 struct ext4_group_info info;
2528 ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
2533 seq_puts(seq, "#group: free frags first ["
2534 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
2535 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
2537 i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2538 sizeof(struct ext4_group_info);
2540 grinfo = ext4_get_group_info(sb, group);
2541 /* Load the group info in memory only if not already loaded. */
2542 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
2543 err = ext4_mb_load_buddy(sb, group, &e4b);
2545 seq_printf(seq, "#%-5u: I/O error\n", group);
2551 memcpy(&sg, ext4_get_group_info(sb, group), i);
2554 ext4_mb_unload_buddy(&e4b);
2556 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
2557 sg.info.bb_fragments, sg.info.bb_first_free);
2558 for (i = 0; i <= 13; i++)
2559 seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
2560 sg.info.bb_counters[i] : 0);
2561 seq_puts(seq, " ]\n");
2566 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2570 const struct seq_operations ext4_mb_seq_groups_ops = {
2571 .start = ext4_mb_seq_groups_start,
2572 .next = ext4_mb_seq_groups_next,
2573 .stop = ext4_mb_seq_groups_stop,
2574 .show = ext4_mb_seq_groups_show,
2577 static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
2579 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2580 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
2587 * Allocate the top-level s_group_info array for the specified number
2590 int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
2592 struct ext4_sb_info *sbi = EXT4_SB(sb);
2594 struct ext4_group_info ***old_groupinfo, ***new_groupinfo;
2596 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
2597 EXT4_DESC_PER_BLOCK_BITS(sb);
2598 if (size <= sbi->s_group_info_size)
2601 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
2602 new_groupinfo = kvzalloc(size, GFP_KERNEL);
2603 if (!new_groupinfo) {
2604 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
2608 old_groupinfo = rcu_dereference(sbi->s_group_info);
2610 memcpy(new_groupinfo, old_groupinfo,
2611 sbi->s_group_info_size * sizeof(*sbi->s_group_info));
2613 rcu_assign_pointer(sbi->s_group_info, new_groupinfo);
2614 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
2616 ext4_kvfree_array_rcu(old_groupinfo);
2617 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2618 sbi->s_group_info_size);
2622 /* Create and initialize ext4_group_info data for the given group. */
2623 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
2624 struct ext4_group_desc *desc)
2628 int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb);
2629 struct ext4_sb_info *sbi = EXT4_SB(sb);
2630 struct ext4_group_info **meta_group_info;
2631 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2634 * First check if this group is the first of a reserved block.
2635 * If it's true, we have to allocate a new table of pointers
2636 * to ext4_group_info structures
2638 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2639 metalen = sizeof(*meta_group_info) <<
2640 EXT4_DESC_PER_BLOCK_BITS(sb);
2641 meta_group_info = kmalloc(metalen, GFP_NOFS);
2642 if (meta_group_info == NULL) {
2643 ext4_msg(sb, KERN_ERR, "can't allocate mem "
2644 "for a buddy group");
2645 goto exit_meta_group_info;
2648 rcu_dereference(sbi->s_group_info)[idx] = meta_group_info;
2652 meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx);
2653 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
2655 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
2656 if (meta_group_info[i] == NULL) {
2657 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
2658 goto exit_group_info;
2660 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2661 &(meta_group_info[i]->bb_state));
2664 * initialize bb_free to be able to skip
2665 * empty groups without initialization
2667 if (ext4_has_group_desc_csum(sb) &&
2668 (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
2669 meta_group_info[i]->bb_free =
2670 ext4_free_clusters_after_init(sb, group, desc);
2672 meta_group_info[i]->bb_free =
2673 ext4_free_group_clusters(sb, desc);
2676 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
2677 init_rwsem(&meta_group_info[i]->alloc_sem);
2678 meta_group_info[i]->bb_free_root = RB_ROOT;
2679 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
2681 mb_group_bb_bitmap_alloc(sb, meta_group_info[i], group);
2685 /* If a meta_group_info table has been allocated, release it now */
2686 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2687 struct ext4_group_info ***group_info;
2690 group_info = rcu_dereference(sbi->s_group_info);
2691 kfree(group_info[idx]);
2692 group_info[idx] = NULL;
2695 exit_meta_group_info:
2697 } /* ext4_mb_add_groupinfo */
2699 static int ext4_mb_init_backend(struct super_block *sb)
2701 ext4_group_t ngroups = ext4_get_groups_count(sb);
2703 struct ext4_sb_info *sbi = EXT4_SB(sb);
2705 struct ext4_group_desc *desc;
2706 struct ext4_group_info ***group_info;
2707 struct kmem_cache *cachep;
2709 err = ext4_mb_alloc_groupinfo(sb, ngroups);
2713 sbi->s_buddy_cache = new_inode(sb);
2714 if (sbi->s_buddy_cache == NULL) {
2715 ext4_msg(sb, KERN_ERR, "can't get new inode");
2718 /* To avoid potentially colliding with an valid on-disk inode number,
2719 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2720 * not in the inode hash, so it should never be found by iget(), but
2721 * this will avoid confusion if it ever shows up during debugging. */
2722 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
2723 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2724 for (i = 0; i < ngroups; i++) {
2726 desc = ext4_get_group_desc(sb, i, NULL);
2728 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
2731 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
2735 if (ext4_has_feature_flex_bg(sb)) {
2736 /* a single flex group is supposed to be read by a single IO.
2737 * 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is
2738 * unsigned integer, so the maximum shift is 32.
2740 if (sbi->s_es->s_log_groups_per_flex >= 32) {
2741 ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group");
2744 sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex,
2745 BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9));
2746 sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */
2748 sbi->s_mb_prefetch = 32;
2750 if (sbi->s_mb_prefetch > ext4_get_groups_count(sb))
2751 sbi->s_mb_prefetch = ext4_get_groups_count(sb);
2752 /* now many real IOs to prefetch within a single allocation at cr=0
2753 * given cr=0 is an CPU-related optimization we shouldn't try to
2754 * load too many groups, at some point we should start to use what
2755 * we've got in memory.
2756 * with an average random access time 5ms, it'd take a second to get
2757 * 200 groups (* N with flex_bg), so let's make this limit 4
2759 sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4;
2760 if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb))
2761 sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb);
2766 cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2768 kmem_cache_free(cachep, ext4_get_group_info(sb, i));
2769 i = sbi->s_group_info_size;
2771 group_info = rcu_dereference(sbi->s_group_info);
2773 kfree(group_info[i]);
2775 iput(sbi->s_buddy_cache);
2778 kvfree(rcu_dereference(sbi->s_group_info));
2783 static void ext4_groupinfo_destroy_slabs(void)
2787 for (i = 0; i < NR_GRPINFO_CACHES; i++) {
2788 kmem_cache_destroy(ext4_groupinfo_caches[i]);
2789 ext4_groupinfo_caches[i] = NULL;
2793 static int ext4_groupinfo_create_slab(size_t size)
2795 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
2797 int blocksize_bits = order_base_2(size);
2798 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2799 struct kmem_cache *cachep;
2801 if (cache_index >= NR_GRPINFO_CACHES)
2804 if (unlikely(cache_index < 0))
2807 mutex_lock(&ext4_grpinfo_slab_create_mutex);
2808 if (ext4_groupinfo_caches[cache_index]) {
2809 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2810 return 0; /* Already created */
2813 slab_size = offsetof(struct ext4_group_info,
2814 bb_counters[blocksize_bits + 2]);
2816 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
2817 slab_size, 0, SLAB_RECLAIM_ACCOUNT,
2820 ext4_groupinfo_caches[cache_index] = cachep;
2822 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2825 "EXT4-fs: no memory for groupinfo slab cache\n");
2832 int ext4_mb_init(struct super_block *sb)
2834 struct ext4_sb_info *sbi = EXT4_SB(sb);
2836 unsigned offset, offset_incr;
2840 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
2842 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2843 if (sbi->s_mb_offsets == NULL) {
2848 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
2849 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2850 if (sbi->s_mb_maxs == NULL) {
2855 ret = ext4_groupinfo_create_slab(sb->s_blocksize);
2859 /* order 0 is regular bitmap */
2860 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2861 sbi->s_mb_offsets[0] = 0;
2865 offset_incr = 1 << (sb->s_blocksize_bits - 1);
2866 max = sb->s_blocksize << 2;
2868 sbi->s_mb_offsets[i] = offset;
2869 sbi->s_mb_maxs[i] = max;
2870 offset += offset_incr;
2871 offset_incr = offset_incr >> 1;
2874 } while (i <= sb->s_blocksize_bits + 1);
2876 spin_lock_init(&sbi->s_md_lock);
2877 spin_lock_init(&sbi->s_bal_lock);
2878 sbi->s_mb_free_pending = 0;
2879 INIT_LIST_HEAD(&sbi->s_freed_data_list);
2881 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2882 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2883 sbi->s_mb_stats = MB_DEFAULT_STATS;
2884 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2885 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2886 sbi->s_mb_max_inode_prealloc = MB_DEFAULT_MAX_INODE_PREALLOC;
2888 * The default group preallocation is 512, which for 4k block
2889 * sizes translates to 2 megabytes. However for bigalloc file
2890 * systems, this is probably too big (i.e, if the cluster size
2891 * is 1 megabyte, then group preallocation size becomes half a
2892 * gigabyte!). As a default, we will keep a two megabyte
2893 * group pralloc size for cluster sizes up to 64k, and after
2894 * that, we will force a minimum group preallocation size of
2895 * 32 clusters. This translates to 8 megs when the cluster
2896 * size is 256k, and 32 megs when the cluster size is 1 meg,
2897 * which seems reasonable as a default.
2899 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
2900 sbi->s_cluster_bits, 32);
2902 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2903 * to the lowest multiple of s_stripe which is bigger than
2904 * the s_mb_group_prealloc as determined above. We want
2905 * the preallocation size to be an exact multiple of the
2906 * RAID stripe size so that preallocations don't fragment
2909 if (sbi->s_stripe > 1) {
2910 sbi->s_mb_group_prealloc = roundup(
2911 sbi->s_mb_group_prealloc, sbi->s_stripe);
2914 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
2915 if (sbi->s_locality_groups == NULL) {
2919 for_each_possible_cpu(i) {
2920 struct ext4_locality_group *lg;
2921 lg = per_cpu_ptr(sbi->s_locality_groups, i);
2922 mutex_init(&lg->lg_mutex);
2923 for (j = 0; j < PREALLOC_TB_SIZE; j++)
2924 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
2925 spin_lock_init(&lg->lg_prealloc_lock);
2928 /* init file for buddy data */
2929 ret = ext4_mb_init_backend(sb);
2931 goto out_free_locality_groups;
2935 out_free_locality_groups:
2936 free_percpu(sbi->s_locality_groups);
2937 sbi->s_locality_groups = NULL;
2939 kfree(sbi->s_mb_offsets);
2940 sbi->s_mb_offsets = NULL;
2941 kfree(sbi->s_mb_maxs);
2942 sbi->s_mb_maxs = NULL;
2946 /* need to called with the ext4 group lock held */
2947 static int ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2949 struct ext4_prealloc_space *pa;
2950 struct list_head *cur, *tmp;
2953 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2954 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2955 list_del(&pa->pa_group_list);
2957 kmem_cache_free(ext4_pspace_cachep, pa);
2962 int ext4_mb_release(struct super_block *sb)
2964 ext4_group_t ngroups = ext4_get_groups_count(sb);
2966 int num_meta_group_infos;
2967 struct ext4_group_info *grinfo, ***group_info;
2968 struct ext4_sb_info *sbi = EXT4_SB(sb);
2969 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2972 if (sbi->s_group_info) {
2973 for (i = 0; i < ngroups; i++) {
2975 grinfo = ext4_get_group_info(sb, i);
2976 mb_group_bb_bitmap_free(grinfo);
2977 ext4_lock_group(sb, i);
2978 count = ext4_mb_cleanup_pa(grinfo);
2980 mb_debug(sb, "mballoc: %d PAs left\n",
2982 ext4_unlock_group(sb, i);
2983 kmem_cache_free(cachep, grinfo);
2985 num_meta_group_infos = (ngroups +
2986 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2987 EXT4_DESC_PER_BLOCK_BITS(sb);
2989 group_info = rcu_dereference(sbi->s_group_info);
2990 for (i = 0; i < num_meta_group_infos; i++)
2991 kfree(group_info[i]);
2995 kfree(sbi->s_mb_offsets);
2996 kfree(sbi->s_mb_maxs);
2997 iput(sbi->s_buddy_cache);
2998 if (sbi->s_mb_stats) {
2999 ext4_msg(sb, KERN_INFO,
3000 "mballoc: %u blocks %u reqs (%u success)",
3001 atomic_read(&sbi->s_bal_allocated),
3002 atomic_read(&sbi->s_bal_reqs),
3003 atomic_read(&sbi->s_bal_success));
3004 ext4_msg(sb, KERN_INFO,
3005 "mballoc: %u extents scanned, %u goal hits, "
3006 "%u 2^N hits, %u breaks, %u lost",
3007 atomic_read(&sbi->s_bal_ex_scanned),
3008 atomic_read(&sbi->s_bal_goals),
3009 atomic_read(&sbi->s_bal_2orders),
3010 atomic_read(&sbi->s_bal_breaks),
3011 atomic_read(&sbi->s_mb_lost_chunks));
3012 ext4_msg(sb, KERN_INFO,
3013 "mballoc: %lu generated and it took %Lu",
3014 sbi->s_mb_buddies_generated,
3015 sbi->s_mb_generation_time);
3016 ext4_msg(sb, KERN_INFO,
3017 "mballoc: %u preallocated, %u discarded",
3018 atomic_read(&sbi->s_mb_preallocated),
3019 atomic_read(&sbi->s_mb_discarded));
3022 free_percpu(sbi->s_locality_groups);
3027 static inline int ext4_issue_discard(struct super_block *sb,
3028 ext4_group_t block_group, ext4_grpblk_t cluster, int count,
3031 ext4_fsblk_t discard_block;
3033 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
3034 ext4_group_first_block_no(sb, block_group));
3035 count = EXT4_C2B(EXT4_SB(sb), count);
3036 trace_ext4_discard_blocks(sb,
3037 (unsigned long long) discard_block, count);
3039 return __blkdev_issue_discard(sb->s_bdev,
3040 (sector_t)discard_block << (sb->s_blocksize_bits - 9),
3041 (sector_t)count << (sb->s_blocksize_bits - 9),
3044 return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
3047 static void ext4_free_data_in_buddy(struct super_block *sb,
3048 struct ext4_free_data *entry)
3050 struct ext4_buddy e4b;
3051 struct ext4_group_info *db;
3052 int err, count = 0, count2 = 0;
3054 mb_debug(sb, "gonna free %u blocks in group %u (0x%p):",
3055 entry->efd_count, entry->efd_group, entry);
3057 err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
3058 /* we expect to find existing buddy because it's pinned */
3061 spin_lock(&EXT4_SB(sb)->s_md_lock);
3062 EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
3063 spin_unlock(&EXT4_SB(sb)->s_md_lock);
3066 /* there are blocks to put in buddy to make them really free */
3067 count += entry->efd_count;
3069 ext4_lock_group(sb, entry->efd_group);
3070 /* Take it out of per group rb tree */
3071 rb_erase(&entry->efd_node, &(db->bb_free_root));
3072 mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count);
3075 * Clear the trimmed flag for the group so that the next
3076 * ext4_trim_fs can trim it.
3077 * If the volume is mounted with -o discard, online discard
3078 * is supported and the free blocks will be trimmed online.
3080 if (!test_opt(sb, DISCARD))
3081 EXT4_MB_GRP_CLEAR_TRIMMED(db);
3083 if (!db->bb_free_root.rb_node) {
3084 /* No more items in the per group rb tree
3085 * balance refcounts from ext4_mb_free_metadata()
3087 put_page(e4b.bd_buddy_page);
3088 put_page(e4b.bd_bitmap_page);
3090 ext4_unlock_group(sb, entry->efd_group);
3091 kmem_cache_free(ext4_free_data_cachep, entry);
3092 ext4_mb_unload_buddy(&e4b);
3094 mb_debug(sb, "freed %d blocks in %d structures\n", count,
3099 * This function is called by the jbd2 layer once the commit has finished,
3100 * so we know we can free the blocks that were released with that commit.
3102 void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
3104 struct ext4_sb_info *sbi = EXT4_SB(sb);
3105 struct ext4_free_data *entry, *tmp;
3106 struct bio *discard_bio = NULL;
3107 struct list_head freed_data_list;
3108 struct list_head *cut_pos = NULL;
3111 INIT_LIST_HEAD(&freed_data_list);
3113 spin_lock(&sbi->s_md_lock);
3114 list_for_each_entry(entry, &sbi->s_freed_data_list, efd_list) {
3115 if (entry->efd_tid != commit_tid)
3117 cut_pos = &entry->efd_list;
3120 list_cut_position(&freed_data_list, &sbi->s_freed_data_list,
3122 spin_unlock(&sbi->s_md_lock);
3124 if (test_opt(sb, DISCARD)) {
3125 list_for_each_entry(entry, &freed_data_list, efd_list) {
3126 err = ext4_issue_discard(sb, entry->efd_group,
3127 entry->efd_start_cluster,
3130 if (err && err != -EOPNOTSUPP) {
3131 ext4_msg(sb, KERN_WARNING, "discard request in"
3132 " group:%d block:%d count:%d failed"
3133 " with %d", entry->efd_group,
3134 entry->efd_start_cluster,
3135 entry->efd_count, err);
3136 } else if (err == -EOPNOTSUPP)
3141 submit_bio_wait(discard_bio);
3142 bio_put(discard_bio);
3146 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
3147 ext4_free_data_in_buddy(sb, entry);
3150 int __init ext4_init_mballoc(void)
3152 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
3153 SLAB_RECLAIM_ACCOUNT);
3154 if (ext4_pspace_cachep == NULL)
3157 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
3158 SLAB_RECLAIM_ACCOUNT);
3159 if (ext4_ac_cachep == NULL)
3162 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
3163 SLAB_RECLAIM_ACCOUNT);
3164 if (ext4_free_data_cachep == NULL)
3170 kmem_cache_destroy(ext4_ac_cachep);
3172 kmem_cache_destroy(ext4_pspace_cachep);
3177 void ext4_exit_mballoc(void)
3180 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
3181 * before destroying the slab cache.
3184 kmem_cache_destroy(ext4_pspace_cachep);
3185 kmem_cache_destroy(ext4_ac_cachep);
3186 kmem_cache_destroy(ext4_free_data_cachep);
3187 ext4_groupinfo_destroy_slabs();
3192 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
3193 * Returns 0 if success or error code
3195 static noinline_for_stack int
3196 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
3197 handle_t *handle, unsigned int reserv_clstrs)
3199 struct buffer_head *bitmap_bh = NULL;
3200 struct ext4_group_desc *gdp;
3201 struct buffer_head *gdp_bh;
3202 struct ext4_sb_info *sbi;
3203 struct super_block *sb;
3207 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3208 BUG_ON(ac->ac_b_ex.fe_len <= 0);
3213 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
3214 if (IS_ERR(bitmap_bh)) {
3215 err = PTR_ERR(bitmap_bh);
3220 BUFFER_TRACE(bitmap_bh, "getting write access");
3221 err = ext4_journal_get_write_access(handle, bitmap_bh);
3226 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
3230 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
3231 ext4_free_group_clusters(sb, gdp));
3233 BUFFER_TRACE(gdp_bh, "get_write_access");
3234 err = ext4_journal_get_write_access(handle, gdp_bh);
3238 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3240 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
3241 if (!ext4_inode_block_valid(ac->ac_inode, block, len)) {
3242 ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
3243 "fs metadata", block, block+len);
3244 /* File system mounted not to panic on error
3245 * Fix the bitmap and return EFSCORRUPTED
3246 * We leak some of the blocks here.
3248 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3249 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3250 ac->ac_b_ex.fe_len);
3251 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3252 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3254 err = -EFSCORRUPTED;
3258 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3259 #ifdef AGGRESSIVE_CHECK
3262 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3263 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3264 bitmap_bh->b_data));
3268 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3269 ac->ac_b_ex.fe_len);
3270 if (ext4_has_group_desc_csum(sb) &&
3271 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3272 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3273 ext4_free_group_clusters_set(sb, gdp,
3274 ext4_free_clusters_after_init(sb,
3275 ac->ac_b_ex.fe_group, gdp));
3277 len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
3278 ext4_free_group_clusters_set(sb, gdp, len);
3279 ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
3280 ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
3282 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3283 percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
3285 * Now reduce the dirty block count also. Should not go negative
3287 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
3288 /* release all the reserved blocks if non delalloc */
3289 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
3292 if (sbi->s_log_groups_per_flex) {
3293 ext4_group_t flex_group = ext4_flex_group(sbi,
3294 ac->ac_b_ex.fe_group);
3295 atomic64_sub(ac->ac_b_ex.fe_len,
3296 &sbi_array_rcu_deref(sbi, s_flex_groups,
3297 flex_group)->free_clusters);
3300 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3303 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
3311 * Idempotent helper for Ext4 fast commit replay path to set the state of
3312 * blocks in bitmaps and update counters.
3314 void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
3317 struct buffer_head *bitmap_bh = NULL;
3318 struct ext4_group_desc *gdp;
3319 struct buffer_head *gdp_bh;
3320 struct ext4_sb_info *sbi = EXT4_SB(sb);
3322 ext4_grpblk_t blkoff;
3325 unsigned int clen, clen_changed, thisgrp_len;
3328 ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
3331 * Check to see if we are freeing blocks across a group
3333 * In case of flex_bg, this can happen that (block, len) may
3334 * span across more than one group. In that case we need to
3335 * get the corresponding group metadata to work with.
3336 * For this we have goto again loop.
3338 thisgrp_len = min_t(unsigned int, (unsigned int)len,
3339 EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
3340 clen = EXT4_NUM_B2C(sbi, thisgrp_len);
3342 bitmap_bh = ext4_read_block_bitmap(sb, group);
3343 if (IS_ERR(bitmap_bh)) {
3344 err = PTR_ERR(bitmap_bh);
3350 gdp = ext4_get_group_desc(sb, group, &gdp_bh);
3354 ext4_lock_group(sb, group);
3356 for (i = 0; i < clen; i++)
3357 if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) ==
3361 clen_changed = clen - already;
3363 ext4_set_bits(bitmap_bh->b_data, blkoff, clen);
3365 mb_test_and_clear_bits(bitmap_bh->b_data, blkoff, clen);
3366 if (ext4_has_group_desc_csum(sb) &&
3367 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3368 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3369 ext4_free_group_clusters_set(sb, gdp,
3370 ext4_free_clusters_after_init(sb, group, gdp));
3373 clen = ext4_free_group_clusters(sb, gdp) - clen_changed;
3375 clen = ext4_free_group_clusters(sb, gdp) + clen_changed;
3377 ext4_free_group_clusters_set(sb, gdp, clen);
3378 ext4_block_bitmap_csum_set(sb, group, gdp, bitmap_bh);
3379 ext4_group_desc_csum_set(sb, group, gdp);
3381 ext4_unlock_group(sb, group);
3383 if (sbi->s_log_groups_per_flex) {
3384 ext4_group_t flex_group = ext4_flex_group(sbi, group);
3385 struct flex_groups *fg = sbi_array_rcu_deref(sbi,
3386 s_flex_groups, flex_group);
3389 atomic64_sub(clen_changed, &fg->free_clusters);
3391 atomic64_add(clen_changed, &fg->free_clusters);
3395 err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh);
3398 sync_dirty_buffer(bitmap_bh);
3399 err = ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
3400 sync_dirty_buffer(gdp_bh);
3404 block += thisgrp_len;
3415 * here we normalize request for locality group
3416 * Group request are normalized to s_mb_group_prealloc, which goes to
3417 * s_strip if we set the same via mount option.
3418 * s_mb_group_prealloc can be configured via
3419 * /sys/fs/ext4/<partition>/mb_group_prealloc
3421 * XXX: should we try to preallocate more than the group has now?
3423 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3425 struct super_block *sb = ac->ac_sb;
3426 struct ext4_locality_group *lg = ac->ac_lg;
3429 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3430 mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len);
3434 * Normalization means making request better in terms of
3435 * size and alignment
3437 static noinline_for_stack void
3438 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
3439 struct ext4_allocation_request *ar)
3441 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3444 loff_t size, start_off;
3445 loff_t orig_size __maybe_unused;
3447 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3448 struct ext4_prealloc_space *pa;
3450 /* do normalize only data requests, metadata requests
3451 do not need preallocation */
3452 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3455 /* sometime caller may want exact blocks */
3456 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3459 /* caller may indicate that preallocation isn't
3460 * required (it's a tail, for example) */
3461 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3464 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3465 ext4_mb_normalize_group_request(ac);
3469 bsbits = ac->ac_sb->s_blocksize_bits;
3471 /* first, let's learn actual file size
3472 * given current request is allocated */
3473 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
3474 size = size << bsbits;
3475 if (size < i_size_read(ac->ac_inode))
3476 size = i_size_read(ac->ac_inode);
3479 /* max size of free chunks */
3482 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3483 (req <= (size) || max <= (chunk_size))
3485 /* first, try to predict filesize */
3486 /* XXX: should this table be tunable? */
3488 if (size <= 16 * 1024) {
3490 } else if (size <= 32 * 1024) {
3492 } else if (size <= 64 * 1024) {
3494 } else if (size <= 128 * 1024) {
3496 } else if (size <= 256 * 1024) {
3498 } else if (size <= 512 * 1024) {
3500 } else if (size <= 1024 * 1024) {
3502 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
3503 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3504 (21 - bsbits)) << 21;
3505 size = 2 * 1024 * 1024;
3506 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
3507 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3508 (22 - bsbits)) << 22;
3509 size = 4 * 1024 * 1024;
3510 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3511 (8<<20)>>bsbits, max, 8 * 1024)) {
3512 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3513 (23 - bsbits)) << 23;
3514 size = 8 * 1024 * 1024;
3516 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
3517 size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
3518 ac->ac_o_ex.fe_len) << bsbits;
3520 size = size >> bsbits;
3521 start = start_off >> bsbits;
3524 * For tiny groups (smaller than 8MB) the chosen allocation
3525 * alignment may be larger than group size. Make sure the
3526 * alignment does not move allocation to a different group which
3527 * makes mballoc fail assertions later.
3529 start = max(start, rounddown(ac->ac_o_ex.fe_logical,
3530 (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
3532 /* don't cover already allocated blocks in selected range */
3533 if (ar->pleft && start <= ar->lleft) {
3534 size -= ar->lleft + 1 - start;
3535 start = ar->lleft + 1;
3537 if (ar->pright && start + size - 1 >= ar->lright)
3538 size -= start + size - ar->lright;
3541 * Trim allocation request for filesystems with artificially small
3544 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
3545 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
3549 /* check we don't cross already preallocated blocks */
3551 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3556 spin_lock(&pa->pa_lock);
3557 if (pa->pa_deleted) {
3558 spin_unlock(&pa->pa_lock);
3562 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3565 /* PA must not overlap original request */
3566 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3567 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3569 /* skip PAs this normalized request doesn't overlap with */
3570 if (pa->pa_lstart >= end || pa_end <= start) {
3571 spin_unlock(&pa->pa_lock);
3574 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3576 /* adjust start or end to be adjacent to this pa */
3577 if (pa_end <= ac->ac_o_ex.fe_logical) {
3578 BUG_ON(pa_end < start);
3580 } else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3581 BUG_ON(pa->pa_lstart > end);
3582 end = pa->pa_lstart;
3584 spin_unlock(&pa->pa_lock);
3589 /* XXX: extra loop to check we really don't overlap preallocations */
3591 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3594 spin_lock(&pa->pa_lock);
3595 if (pa->pa_deleted == 0) {
3596 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3598 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3600 spin_unlock(&pa->pa_lock);
3604 if (start + size <= ac->ac_o_ex.fe_logical &&
3605 start > ac->ac_o_ex.fe_logical) {
3606 ext4_msg(ac->ac_sb, KERN_ERR,
3607 "start %lu, size %lu, fe_logical %lu",
3608 (unsigned long) start, (unsigned long) size,
3609 (unsigned long) ac->ac_o_ex.fe_logical);
3612 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3614 /* now prepare goal request */
3616 /* XXX: is it better to align blocks WRT to logical
3617 * placement or satisfy big request as is */
3618 ac->ac_g_ex.fe_logical = start;
3619 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
3621 /* define goal start in order to merge */
3622 if (ar->pright && (ar->lright == (start + size))) {
3623 /* merge to the right */
3624 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3625 &ac->ac_f_ex.fe_group,
3626 &ac->ac_f_ex.fe_start);
3627 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3629 if (ar->pleft && (ar->lleft + 1 == start)) {
3630 /* merge to the left */
3631 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3632 &ac->ac_f_ex.fe_group,
3633 &ac->ac_f_ex.fe_start);
3634 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3637 mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size,
3641 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3643 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3645 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3646 atomic_inc(&sbi->s_bal_reqs);
3647 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3648 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
3649 atomic_inc(&sbi->s_bal_success);
3650 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3651 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3652 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3653 atomic_inc(&sbi->s_bal_goals);
3654 if (ac->ac_found > sbi->s_mb_max_to_scan)
3655 atomic_inc(&sbi->s_bal_breaks);
3658 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
3659 trace_ext4_mballoc_alloc(ac);
3661 trace_ext4_mballoc_prealloc(ac);
3665 * Called on failure; free up any blocks from the inode PA for this
3666 * context. We don't need this for MB_GROUP_PA because we only change
3667 * pa_free in ext4_mb_release_context(), but on failure, we've already
3668 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3670 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
3672 struct ext4_prealloc_space *pa = ac->ac_pa;
3673 struct ext4_buddy e4b;
3677 if (ac->ac_f_ex.fe_len == 0)
3679 err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
3682 * This should never happen since we pin the
3683 * pages in the ext4_allocation_context so
3684 * ext4_mb_load_buddy() should never fail.
3686 WARN(1, "mb_load_buddy failed (%d)", err);
3689 ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3690 mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
3691 ac->ac_f_ex.fe_len);
3692 ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3693 ext4_mb_unload_buddy(&e4b);
3696 if (pa->pa_type == MB_INODE_PA)
3697 pa->pa_free += ac->ac_b_ex.fe_len;
3701 * use blocks preallocated to inode
3703 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3704 struct ext4_prealloc_space *pa)
3706 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3711 /* found preallocated blocks, use them */
3712 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3713 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
3714 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
3715 len = EXT4_NUM_B2C(sbi, end - start);
3716 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3717 &ac->ac_b_ex.fe_start);
3718 ac->ac_b_ex.fe_len = len;
3719 ac->ac_status = AC_STATUS_FOUND;
3722 BUG_ON(start < pa->pa_pstart);
3723 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
3724 BUG_ON(pa->pa_free < len);
3727 mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa);
3731 * use blocks preallocated to locality group
3733 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3734 struct ext4_prealloc_space *pa)
3736 unsigned int len = ac->ac_o_ex.fe_len;
3738 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3739 &ac->ac_b_ex.fe_group,
3740 &ac->ac_b_ex.fe_start);
3741 ac->ac_b_ex.fe_len = len;
3742 ac->ac_status = AC_STATUS_FOUND;
3745 /* we don't correct pa_pstart or pa_plen here to avoid
3746 * possible race when the group is being loaded concurrently
3747 * instead we correct pa later, after blocks are marked
3748 * in on-disk bitmap -- see ext4_mb_release_context()
3749 * Other CPUs are prevented from allocating from this pa by lg_mutex
3751 mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n",
3752 pa->pa_lstart-len, len, pa);
3756 * Return the prealloc space that have minimal distance
3757 * from the goal block. @cpa is the prealloc
3758 * space that is having currently known minimal distance
3759 * from the goal block.
3761 static struct ext4_prealloc_space *
3762 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
3763 struct ext4_prealloc_space *pa,
3764 struct ext4_prealloc_space *cpa)
3766 ext4_fsblk_t cur_distance, new_distance;
3769 atomic_inc(&pa->pa_count);
3772 cur_distance = abs(goal_block - cpa->pa_pstart);
3773 new_distance = abs(goal_block - pa->pa_pstart);
3775 if (cur_distance <= new_distance)
3778 /* drop the previous reference */
3779 atomic_dec(&cpa->pa_count);
3780 atomic_inc(&pa->pa_count);
3785 * search goal blocks in preallocated space
3787 static noinline_for_stack bool
3788 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
3790 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3792 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3793 struct ext4_locality_group *lg;
3794 struct ext4_prealloc_space *pa, *cpa = NULL;
3795 ext4_fsblk_t goal_block;
3797 /* only data can be preallocated */
3798 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3801 /* first, try per-file preallocation */
3803 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3805 /* all fields in this condition don't change,
3806 * so we can skip locking for them */
3807 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3808 ac->ac_o_ex.fe_logical >= (pa->pa_lstart +
3809 EXT4_C2B(sbi, pa->pa_len)))
3812 /* non-extent files can't have physical blocks past 2^32 */
3813 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) &&
3814 (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) >
3815 EXT4_MAX_BLOCK_FILE_PHYS))
3818 /* found preallocated blocks, use them */
3819 spin_lock(&pa->pa_lock);
3820 if (pa->pa_deleted == 0 && pa->pa_free) {
3821 atomic_inc(&pa->pa_count);
3822 ext4_mb_use_inode_pa(ac, pa);
3823 spin_unlock(&pa->pa_lock);
3824 ac->ac_criteria = 10;
3828 spin_unlock(&pa->pa_lock);
3832 /* can we use group allocation? */
3833 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3836 /* inode may have no locality group for some reason */
3840 order = fls(ac->ac_o_ex.fe_len) - 1;
3841 if (order > PREALLOC_TB_SIZE - 1)
3842 /* The max size of hash table is PREALLOC_TB_SIZE */
3843 order = PREALLOC_TB_SIZE - 1;
3845 goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex);
3847 * search for the prealloc space that is having
3848 * minimal distance from the goal block.
3850 for (i = order; i < PREALLOC_TB_SIZE; i++) {
3852 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
3854 spin_lock(&pa->pa_lock);
3855 if (pa->pa_deleted == 0 &&
3856 pa->pa_free >= ac->ac_o_ex.fe_len) {
3858 cpa = ext4_mb_check_group_pa(goal_block,
3861 spin_unlock(&pa->pa_lock);
3866 ext4_mb_use_group_pa(ac, cpa);
3867 ac->ac_criteria = 20;
3874 * the function goes through all block freed in the group
3875 * but not yet committed and marks them used in in-core bitmap.
3876 * buddy must be generated from this bitmap
3877 * Need to be called with the ext4 group lock held
3879 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
3883 struct ext4_group_info *grp;
3884 struct ext4_free_data *entry;
3886 grp = ext4_get_group_info(sb, group);
3887 n = rb_first(&(grp->bb_free_root));
3890 entry = rb_entry(n, struct ext4_free_data, efd_node);
3891 ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count);
3898 * the function goes through all preallocation in this group and marks them
3899 * used in in-core bitmap. buddy must be generated from this bitmap
3900 * Need to be called with ext4 group lock held
3902 static noinline_for_stack
3903 void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3906 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3907 struct ext4_prealloc_space *pa;
3908 struct list_head *cur;
3909 ext4_group_t groupnr;
3910 ext4_grpblk_t start;
3911 int preallocated = 0;
3914 /* all form of preallocation discards first load group,
3915 * so the only competing code is preallocation use.
3916 * we don't need any locking here
3917 * notice we do NOT ignore preallocations with pa_deleted
3918 * otherwise we could leave used blocks available for
3919 * allocation in buddy when concurrent ext4_mb_put_pa()
3920 * is dropping preallocation
3922 list_for_each(cur, &grp->bb_prealloc_list) {
3923 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3924 spin_lock(&pa->pa_lock);
3925 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3928 spin_unlock(&pa->pa_lock);
3929 if (unlikely(len == 0))
3931 BUG_ON(groupnr != group);
3932 ext4_set_bits(bitmap, start, len);
3933 preallocated += len;
3935 mb_debug(sb, "preallocated %d for group %u\n", preallocated, group);
3938 static void ext4_mb_mark_pa_deleted(struct super_block *sb,
3939 struct ext4_prealloc_space *pa)
3941 struct ext4_inode_info *ei;
3943 if (pa->pa_deleted) {
3944 ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n",
3945 pa->pa_type, pa->pa_pstart, pa->pa_lstart,
3952 if (pa->pa_type == MB_INODE_PA) {
3953 ei = EXT4_I(pa->pa_inode);
3954 atomic_dec(&ei->i_prealloc_active);
3958 static void ext4_mb_pa_callback(struct rcu_head *head)
3960 struct ext4_prealloc_space *pa;
3961 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3963 BUG_ON(atomic_read(&pa->pa_count));
3964 BUG_ON(pa->pa_deleted == 0);
3965 kmem_cache_free(ext4_pspace_cachep, pa);
3969 * drops a reference to preallocated space descriptor
3970 * if this was the last reference and the space is consumed
3972 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3973 struct super_block *sb, struct ext4_prealloc_space *pa)
3976 ext4_fsblk_t grp_blk;
3978 /* in this short window concurrent discard can set pa_deleted */
3979 spin_lock(&pa->pa_lock);
3980 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {
3981 spin_unlock(&pa->pa_lock);
3985 if (pa->pa_deleted == 1) {
3986 spin_unlock(&pa->pa_lock);
3990 ext4_mb_mark_pa_deleted(sb, pa);
3991 spin_unlock(&pa->pa_lock);
3993 grp_blk = pa->pa_pstart;
3995 * If doing group-based preallocation, pa_pstart may be in the
3996 * next group when pa is used up
3998 if (pa->pa_type == MB_GROUP_PA)
4001 grp = ext4_get_group_number(sb, grp_blk);
4006 * P1 (buddy init) P2 (regular allocation)
4007 * find block B in PA
4008 * copy on-disk bitmap to buddy
4009 * mark B in on-disk bitmap
4010 * drop PA from group
4011 * mark all PAs in buddy
4013 * thus, P1 initializes buddy with B available. to prevent this
4014 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
4017 ext4_lock_group(sb, grp);
4018 list_del(&pa->pa_group_list);
4019 ext4_unlock_group(sb, grp);
4021 spin_lock(pa->pa_obj_lock);
4022 list_del_rcu(&pa->pa_inode_list);
4023 spin_unlock(pa->pa_obj_lock);
4025 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4029 * creates new preallocated space for given inode
4031 static noinline_for_stack void
4032 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
4034 struct super_block *sb = ac->ac_sb;
4035 struct ext4_sb_info *sbi = EXT4_SB(sb);
4036 struct ext4_prealloc_space *pa;
4037 struct ext4_group_info *grp;
4038 struct ext4_inode_info *ei;
4040 /* preallocate only when found space is larger then requested */
4041 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
4042 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
4043 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
4044 BUG_ON(ac->ac_pa == NULL);
4048 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
4054 /* we can't allocate as much as normalizer wants.
4055 * so, found space must get proper lstart
4056 * to cover original request */
4057 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
4058 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
4060 /* we're limited by original request in that
4061 * logical block must be covered any way
4062 * winl is window we can move our chunk within */
4063 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
4065 /* also, we should cover whole original request */
4066 wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len);
4068 /* the smallest one defines real window */
4069 win = min(winl, wins);
4071 offs = ac->ac_o_ex.fe_logical %
4072 EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4073 if (offs && offs < win)
4076 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical -
4077 EXT4_NUM_B2C(sbi, win);
4078 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
4079 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
4082 /* preallocation can change ac_b_ex, thus we store actually
4083 * allocated blocks for history */
4084 ac->ac_f_ex = ac->ac_b_ex;
4086 pa->pa_lstart = ac->ac_b_ex.fe_logical;
4087 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4088 pa->pa_len = ac->ac_b_ex.fe_len;
4089 pa->pa_free = pa->pa_len;
4090 spin_lock_init(&pa->pa_lock);
4091 INIT_LIST_HEAD(&pa->pa_inode_list);
4092 INIT_LIST_HEAD(&pa->pa_group_list);
4094 pa->pa_type = MB_INODE_PA;
4096 mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
4097 pa->pa_len, pa->pa_lstart);
4098 trace_ext4_mb_new_inode_pa(ac, pa);
4100 ext4_mb_use_inode_pa(ac, pa);
4101 atomic_add(pa->pa_free, &sbi->s_mb_preallocated);
4103 ei = EXT4_I(ac->ac_inode);
4104 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
4106 pa->pa_obj_lock = &ei->i_prealloc_lock;
4107 pa->pa_inode = ac->ac_inode;
4109 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
4111 spin_lock(pa->pa_obj_lock);
4112 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
4113 spin_unlock(pa->pa_obj_lock);
4114 atomic_inc(&ei->i_prealloc_active);
4118 * creates new preallocated space for locality group inodes belongs to
4120 static noinline_for_stack void
4121 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
4123 struct super_block *sb = ac->ac_sb;
4124 struct ext4_locality_group *lg;
4125 struct ext4_prealloc_space *pa;
4126 struct ext4_group_info *grp;
4128 /* preallocate only when found space is larger then requested */
4129 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
4130 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
4131 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
4132 BUG_ON(ac->ac_pa == NULL);
4136 /* preallocation can change ac_b_ex, thus we store actually
4137 * allocated blocks for history */
4138 ac->ac_f_ex = ac->ac_b_ex;
4140 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4141 pa->pa_lstart = pa->pa_pstart;
4142 pa->pa_len = ac->ac_b_ex.fe_len;
4143 pa->pa_free = pa->pa_len;
4144 spin_lock_init(&pa->pa_lock);
4145 INIT_LIST_HEAD(&pa->pa_inode_list);
4146 INIT_LIST_HEAD(&pa->pa_group_list);
4148 pa->pa_type = MB_GROUP_PA;
4150 mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
4151 pa->pa_len, pa->pa_lstart);
4152 trace_ext4_mb_new_group_pa(ac, pa);
4154 ext4_mb_use_group_pa(ac, pa);
4155 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
4157 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
4161 pa->pa_obj_lock = &lg->lg_prealloc_lock;
4162 pa->pa_inode = NULL;
4164 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
4167 * We will later add the new pa to the right bucket
4168 * after updating the pa_free in ext4_mb_release_context
4172 static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
4174 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4175 ext4_mb_new_group_pa(ac);
4177 ext4_mb_new_inode_pa(ac);
4181 * finds all unused blocks in on-disk bitmap, frees them in
4182 * in-core bitmap and buddy.
4183 * @pa must be unlinked from inode and group lists, so that
4184 * nobody else can find/use it.
4185 * the caller MUST hold group/inode locks.
4186 * TODO: optimize the case when there are no in-core structures yet
4188 static noinline_for_stack int
4189 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
4190 struct ext4_prealloc_space *pa)
4192 struct super_block *sb = e4b->bd_sb;
4193 struct ext4_sb_info *sbi = EXT4_SB(sb);
4198 unsigned long long grp_blk_start;
4201 BUG_ON(pa->pa_deleted == 0);
4202 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
4203 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
4204 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
4205 end = bit + pa->pa_len;
4208 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
4211 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
4212 mb_debug(sb, "free preallocated %u/%u in group %u\n",
4213 (unsigned) ext4_group_first_block_no(sb, group) + bit,
4214 (unsigned) next - bit, (unsigned) group);
4217 trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);
4218 trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +
4219 EXT4_C2B(sbi, bit)),
4221 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
4224 if (free != pa->pa_free) {
4225 ext4_msg(e4b->bd_sb, KERN_CRIT,
4226 "pa %p: logic %lu, phys. %lu, len %d",
4227 pa, (unsigned long) pa->pa_lstart,
4228 (unsigned long) pa->pa_pstart,
4230 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
4233 * pa is already deleted so we use the value obtained
4234 * from the bitmap and continue.
4237 atomic_add(free, &sbi->s_mb_discarded);
4242 static noinline_for_stack int
4243 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
4244 struct ext4_prealloc_space *pa)
4246 struct super_block *sb = e4b->bd_sb;
4250 trace_ext4_mb_release_group_pa(sb, pa);
4251 BUG_ON(pa->pa_deleted == 0);
4252 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
4253 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
4254 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
4255 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
4256 trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);
4262 * releases all preallocations in given group
4264 * first, we need to decide discard policy:
4265 * - when do we discard
4267 * - how many do we discard
4268 * 1) how many requested
4270 static noinline_for_stack int
4271 ext4_mb_discard_group_preallocations(struct super_block *sb,
4272 ext4_group_t group, int *busy)
4274 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
4275 struct buffer_head *bitmap_bh = NULL;
4276 struct ext4_prealloc_space *pa, *tmp;
4277 struct list_head list;
4278 struct ext4_buddy e4b;
4282 mb_debug(sb, "discard preallocation for group %u\n", group);
4283 if (list_empty(&grp->bb_prealloc_list))
4286 bitmap_bh = ext4_read_block_bitmap(sb, group);
4287 if (IS_ERR(bitmap_bh)) {
4288 err = PTR_ERR(bitmap_bh);
4289 ext4_error_err(sb, -err,
4290 "Error %d reading block bitmap for %u",
4295 err = ext4_mb_load_buddy(sb, group, &e4b);
4297 ext4_warning(sb, "Error %d loading buddy information for %u",
4303 INIT_LIST_HEAD(&list);
4304 ext4_lock_group(sb, group);
4305 list_for_each_entry_safe(pa, tmp,
4306 &grp->bb_prealloc_list, pa_group_list) {
4307 spin_lock(&pa->pa_lock);
4308 if (atomic_read(&pa->pa_count)) {
4309 spin_unlock(&pa->pa_lock);
4313 if (pa->pa_deleted) {
4314 spin_unlock(&pa->pa_lock);
4318 /* seems this one can be freed ... */
4319 ext4_mb_mark_pa_deleted(sb, pa);
4322 this_cpu_inc(discard_pa_seq);
4324 /* we can trust pa_free ... */
4325 free += pa->pa_free;
4327 spin_unlock(&pa->pa_lock);
4329 list_del(&pa->pa_group_list);
4330 list_add(&pa->u.pa_tmp_list, &list);
4333 /* now free all selected PAs */
4334 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4336 /* remove from object (inode or locality group) */
4337 spin_lock(pa->pa_obj_lock);
4338 list_del_rcu(&pa->pa_inode_list);
4339 spin_unlock(pa->pa_obj_lock);
4341 if (pa->pa_type == MB_GROUP_PA)
4342 ext4_mb_release_group_pa(&e4b, pa);
4344 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4346 list_del(&pa->u.pa_tmp_list);
4347 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4350 ext4_unlock_group(sb, group);
4351 ext4_mb_unload_buddy(&e4b);
4354 mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
4355 free, group, grp->bb_free);
4360 * releases all non-used preallocated blocks for given inode
4362 * It's important to discard preallocations under i_data_sem
4363 * We don't want another block to be served from the prealloc
4364 * space when we are discarding the inode prealloc space.
4366 * FIXME!! Make sure it is valid at all the call sites
4368 void ext4_discard_preallocations(struct inode *inode, unsigned int needed)
4370 struct ext4_inode_info *ei = EXT4_I(inode);
4371 struct super_block *sb = inode->i_sb;
4372 struct buffer_head *bitmap_bh = NULL;
4373 struct ext4_prealloc_space *pa, *tmp;
4374 ext4_group_t group = 0;
4375 struct list_head list;
4376 struct ext4_buddy e4b;
4379 if (!S_ISREG(inode->i_mode)) {
4380 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
4384 if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
4387 mb_debug(sb, "discard preallocation for inode %lu\n",
4389 trace_ext4_discard_preallocations(inode,
4390 atomic_read(&ei->i_prealloc_active), needed);
4392 INIT_LIST_HEAD(&list);
4398 /* first, collect all pa's in the inode */
4399 spin_lock(&ei->i_prealloc_lock);
4400 while (!list_empty(&ei->i_prealloc_list) && needed) {
4401 pa = list_entry(ei->i_prealloc_list.prev,
4402 struct ext4_prealloc_space, pa_inode_list);
4403 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
4404 spin_lock(&pa->pa_lock);
4405 if (atomic_read(&pa->pa_count)) {
4406 /* this shouldn't happen often - nobody should
4407 * use preallocation while we're discarding it */
4408 spin_unlock(&pa->pa_lock);
4409 spin_unlock(&ei->i_prealloc_lock);
4410 ext4_msg(sb, KERN_ERR,
4411 "uh-oh! used pa while discarding");
4413 schedule_timeout_uninterruptible(HZ);
4417 if (pa->pa_deleted == 0) {
4418 ext4_mb_mark_pa_deleted(sb, pa);
4419 spin_unlock(&pa->pa_lock);
4420 list_del_rcu(&pa->pa_inode_list);
4421 list_add(&pa->u.pa_tmp_list, &list);
4426 /* someone is deleting pa right now */
4427 spin_unlock(&pa->pa_lock);
4428 spin_unlock(&ei->i_prealloc_lock);
4430 /* we have to wait here because pa_deleted
4431 * doesn't mean pa is already unlinked from
4432 * the list. as we might be called from
4433 * ->clear_inode() the inode will get freed
4434 * and concurrent thread which is unlinking
4435 * pa from inode's list may access already
4436 * freed memory, bad-bad-bad */
4438 /* XXX: if this happens too often, we can
4439 * add a flag to force wait only in case
4440 * of ->clear_inode(), but not in case of
4441 * regular truncate */
4442 schedule_timeout_uninterruptible(HZ);
4445 spin_unlock(&ei->i_prealloc_lock);
4447 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4448 BUG_ON(pa->pa_type != MB_INODE_PA);
4449 group = ext4_get_group_number(sb, pa->pa_pstart);
4451 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4452 GFP_NOFS|__GFP_NOFAIL);
4454 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
4459 bitmap_bh = ext4_read_block_bitmap(sb, group);
4460 if (IS_ERR(bitmap_bh)) {
4461 err = PTR_ERR(bitmap_bh);
4462 ext4_error_err(sb, -err, "Error %d reading block bitmap for %u",
4464 ext4_mb_unload_buddy(&e4b);
4468 ext4_lock_group(sb, group);
4469 list_del(&pa->pa_group_list);
4470 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4471 ext4_unlock_group(sb, group);
4473 ext4_mb_unload_buddy(&e4b);
4476 list_del(&pa->u.pa_tmp_list);
4477 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4481 static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac)
4483 struct ext4_prealloc_space *pa;
4485 BUG_ON(ext4_pspace_cachep == NULL);
4486 pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS);
4489 atomic_set(&pa->pa_count, 1);
4494 static void ext4_mb_pa_free(struct ext4_allocation_context *ac)
4496 struct ext4_prealloc_space *pa = ac->ac_pa;
4500 WARN_ON(!atomic_dec_and_test(&pa->pa_count));
4501 kmem_cache_free(ext4_pspace_cachep, pa);
4504 #ifdef CONFIG_EXT4_DEBUG
4505 static inline void ext4_mb_show_pa(struct super_block *sb)
4507 ext4_group_t i, ngroups;
4509 if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
4512 ngroups = ext4_get_groups_count(sb);
4513 mb_debug(sb, "groups: ");
4514 for (i = 0; i < ngroups; i++) {
4515 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4516 struct ext4_prealloc_space *pa;
4517 ext4_grpblk_t start;
4518 struct list_head *cur;
4519 ext4_lock_group(sb, i);
4520 list_for_each(cur, &grp->bb_prealloc_list) {
4521 pa = list_entry(cur, struct ext4_prealloc_space,
4523 spin_lock(&pa->pa_lock);
4524 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4526 spin_unlock(&pa->pa_lock);
4527 mb_debug(sb, "PA:%u:%d:%d\n", i, start,
4530 ext4_unlock_group(sb, i);
4531 mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free,
4536 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4538 struct super_block *sb = ac->ac_sb;
4540 if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
4543 mb_debug(sb, "Can't allocate:"
4544 " Allocation context details:");
4545 mb_debug(sb, "status %u flags 0x%x",
4546 ac->ac_status, ac->ac_flags);
4547 mb_debug(sb, "orig %lu/%lu/%lu@%lu, "
4548 "goal %lu/%lu/%lu@%lu, "
4549 "best %lu/%lu/%lu@%lu cr %d",
4550 (unsigned long)ac->ac_o_ex.fe_group,
4551 (unsigned long)ac->ac_o_ex.fe_start,
4552 (unsigned long)ac->ac_o_ex.fe_len,
4553 (unsigned long)ac->ac_o_ex.fe_logical,
4554 (unsigned long)ac->ac_g_ex.fe_group,
4555 (unsigned long)ac->ac_g_ex.fe_start,
4556 (unsigned long)ac->ac_g_ex.fe_len,
4557 (unsigned long)ac->ac_g_ex.fe_logical,
4558 (unsigned long)ac->ac_b_ex.fe_group,
4559 (unsigned long)ac->ac_b_ex.fe_start,
4560 (unsigned long)ac->ac_b_ex.fe_len,
4561 (unsigned long)ac->ac_b_ex.fe_logical,
4562 (int)ac->ac_criteria);
4563 mb_debug(sb, "%u found", ac->ac_found);
4564 ext4_mb_show_pa(sb);
4567 static inline void ext4_mb_show_pa(struct super_block *sb)
4571 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4573 ext4_mb_show_pa(ac->ac_sb);
4579 * We use locality group preallocation for small size file. The size of the
4580 * file is determined by the current size or the resulting size after
4581 * allocation which ever is larger
4583 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4585 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4587 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4588 int bsbits = ac->ac_sb->s_blocksize_bits;
4591 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4594 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4597 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
4598 isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
4601 if ((size == isize) && !ext4_fs_is_busy(sbi) &&
4602 !inode_is_open_for_write(ac->ac_inode)) {
4603 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
4607 if (sbi->s_mb_group_prealloc <= 0) {
4608 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4612 /* don't use group allocation for large files */
4613 size = max(size, isize);
4614 if (size > sbi->s_mb_stream_request) {
4615 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4619 BUG_ON(ac->ac_lg != NULL);
4621 * locality group prealloc space are per cpu. The reason for having
4622 * per cpu locality group is to reduce the contention between block
4623 * request from multiple CPUs.
4625 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
4627 /* we're going to use group allocation */
4628 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4630 /* serialize all allocations in the group */
4631 mutex_lock(&ac->ac_lg->lg_mutex);
4634 static noinline_for_stack int
4635 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
4636 struct ext4_allocation_request *ar)
4638 struct super_block *sb = ar->inode->i_sb;
4639 struct ext4_sb_info *sbi = EXT4_SB(sb);
4640 struct ext4_super_block *es = sbi->s_es;
4644 ext4_grpblk_t block;
4646 /* we can't allocate > group size */
4649 /* just a dirty hack to filter too big requests */
4650 if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
4651 len = EXT4_CLUSTERS_PER_GROUP(sb);
4653 /* start searching from the goal */
4655 if (goal < le32_to_cpu(es->s_first_data_block) ||
4656 goal >= ext4_blocks_count(es))
4657 goal = le32_to_cpu(es->s_first_data_block);
4658 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4660 /* set up allocation goals */
4661 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
4662 ac->ac_status = AC_STATUS_CONTINUE;
4664 ac->ac_inode = ar->inode;
4665 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
4666 ac->ac_o_ex.fe_group = group;
4667 ac->ac_o_ex.fe_start = block;
4668 ac->ac_o_ex.fe_len = len;
4669 ac->ac_g_ex = ac->ac_o_ex;
4670 ac->ac_flags = ar->flags;
4672 /* we have to define context: we'll work with a file or
4673 * locality group. this is a policy, actually */
4674 ext4_mb_group_or_file(ac);
4676 mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, "
4677 "left: %u/%u, right %u/%u to %swritable\n",
4678 (unsigned) ar->len, (unsigned) ar->logical,
4679 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4680 (unsigned) ar->lleft, (unsigned) ar->pleft,
4681 (unsigned) ar->lright, (unsigned) ar->pright,
4682 inode_is_open_for_write(ar->inode) ? "" : "non-");
4687 static noinline_for_stack void
4688 ext4_mb_discard_lg_preallocations(struct super_block *sb,
4689 struct ext4_locality_group *lg,
4690 int order, int total_entries)
4692 ext4_group_t group = 0;
4693 struct ext4_buddy e4b;
4694 struct list_head discard_list;
4695 struct ext4_prealloc_space *pa, *tmp;
4697 mb_debug(sb, "discard locality group preallocation\n");
4699 INIT_LIST_HEAD(&discard_list);
4701 spin_lock(&lg->lg_prealloc_lock);
4702 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
4704 lockdep_is_held(&lg->lg_prealloc_lock)) {
4705 spin_lock(&pa->pa_lock);
4706 if (atomic_read(&pa->pa_count)) {
4708 * This is the pa that we just used
4709 * for block allocation. So don't
4712 spin_unlock(&pa->pa_lock);
4715 if (pa->pa_deleted) {
4716 spin_unlock(&pa->pa_lock);
4719 /* only lg prealloc space */
4720 BUG_ON(pa->pa_type != MB_GROUP_PA);
4722 /* seems this one can be freed ... */
4723 ext4_mb_mark_pa_deleted(sb, pa);
4724 spin_unlock(&pa->pa_lock);
4726 list_del_rcu(&pa->pa_inode_list);
4727 list_add(&pa->u.pa_tmp_list, &discard_list);
4730 if (total_entries <= 5) {
4732 * we want to keep only 5 entries
4733 * allowing it to grow to 8. This
4734 * mak sure we don't call discard
4735 * soon for this list.
4740 spin_unlock(&lg->lg_prealloc_lock);
4742 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
4745 group = ext4_get_group_number(sb, pa->pa_pstart);
4746 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4747 GFP_NOFS|__GFP_NOFAIL);
4749 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
4753 ext4_lock_group(sb, group);
4754 list_del(&pa->pa_group_list);
4755 ext4_mb_release_group_pa(&e4b, pa);
4756 ext4_unlock_group(sb, group);
4758 ext4_mb_unload_buddy(&e4b);
4759 list_del(&pa->u.pa_tmp_list);
4760 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4765 * We have incremented pa_count. So it cannot be freed at this
4766 * point. Also we hold lg_mutex. So no parallel allocation is
4767 * possible from this lg. That means pa_free cannot be updated.
4769 * A parallel ext4_mb_discard_group_preallocations is possible.
4770 * which can cause the lg_prealloc_list to be updated.
4773 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
4775 int order, added = 0, lg_prealloc_count = 1;
4776 struct super_block *sb = ac->ac_sb;
4777 struct ext4_locality_group *lg = ac->ac_lg;
4778 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
4780 order = fls(pa->pa_free) - 1;
4781 if (order > PREALLOC_TB_SIZE - 1)
4782 /* The max size of hash table is PREALLOC_TB_SIZE */
4783 order = PREALLOC_TB_SIZE - 1;
4784 /* Add the prealloc space to lg */
4785 spin_lock(&lg->lg_prealloc_lock);
4786 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
4788 lockdep_is_held(&lg->lg_prealloc_lock)) {
4789 spin_lock(&tmp_pa->pa_lock);
4790 if (tmp_pa->pa_deleted) {
4791 spin_unlock(&tmp_pa->pa_lock);
4794 if (!added && pa->pa_free < tmp_pa->pa_free) {
4795 /* Add to the tail of the previous entry */
4796 list_add_tail_rcu(&pa->pa_inode_list,
4797 &tmp_pa->pa_inode_list);
4800 * we want to count the total
4801 * number of entries in the list
4804 spin_unlock(&tmp_pa->pa_lock);
4805 lg_prealloc_count++;
4808 list_add_tail_rcu(&pa->pa_inode_list,
4809 &lg->lg_prealloc_list[order]);
4810 spin_unlock(&lg->lg_prealloc_lock);
4812 /* Now trim the list to be not more than 8 elements */
4813 if (lg_prealloc_count > 8) {
4814 ext4_mb_discard_lg_preallocations(sb, lg,
4815 order, lg_prealloc_count);
4822 * if per-inode prealloc list is too long, trim some PA
4824 static void ext4_mb_trim_inode_pa(struct inode *inode)
4826 struct ext4_inode_info *ei = EXT4_I(inode);
4827 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4830 count = atomic_read(&ei->i_prealloc_active);
4831 delta = (sbi->s_mb_max_inode_prealloc >> 2) + 1;
4832 if (count > sbi->s_mb_max_inode_prealloc + delta) {
4833 count -= sbi->s_mb_max_inode_prealloc;
4834 ext4_discard_preallocations(inode, count);
4839 * release all resource we used in allocation
4841 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4843 struct inode *inode = ac->ac_inode;
4844 struct ext4_inode_info *ei = EXT4_I(inode);
4845 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4846 struct ext4_prealloc_space *pa = ac->ac_pa;
4848 if (pa->pa_type == MB_GROUP_PA) {
4849 /* see comment in ext4_mb_use_group_pa() */
4850 spin_lock(&pa->pa_lock);
4851 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4852 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4853 pa->pa_free -= ac->ac_b_ex.fe_len;
4854 pa->pa_len -= ac->ac_b_ex.fe_len;
4855 spin_unlock(&pa->pa_lock);
4858 * We want to add the pa to the right bucket.
4859 * Remove it from the list and while adding
4860 * make sure the list to which we are adding
4863 if (likely(pa->pa_free)) {
4864 spin_lock(pa->pa_obj_lock);
4865 list_del_rcu(&pa->pa_inode_list);
4866 spin_unlock(pa->pa_obj_lock);
4867 ext4_mb_add_n_trim(ac);
4871 if (pa->pa_type == MB_INODE_PA) {
4873 * treat per-inode prealloc list as a lru list, then try
4874 * to trim the least recently used PA.
4876 spin_lock(pa->pa_obj_lock);
4877 list_move(&pa->pa_inode_list, &ei->i_prealloc_list);
4878 spin_unlock(pa->pa_obj_lock);
4881 ext4_mb_put_pa(ac, ac->ac_sb, pa);
4883 if (ac->ac_bitmap_page)
4884 put_page(ac->ac_bitmap_page);
4885 if (ac->ac_buddy_page)
4886 put_page(ac->ac_buddy_page);
4887 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4888 mutex_unlock(&ac->ac_lg->lg_mutex);
4889 ext4_mb_collect_stats(ac);
4890 ext4_mb_trim_inode_pa(inode);
4894 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4896 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4898 int freed = 0, busy = 0;
4901 trace_ext4_mb_discard_preallocations(sb, needed);
4904 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
4906 for (i = 0; i < ngroups && needed > 0; i++) {
4907 ret = ext4_mb_discard_group_preallocations(sb, i, &busy);
4913 if (needed > 0 && busy && ++retry < 3) {
4921 static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb,
4922 struct ext4_allocation_context *ac, u64 *seq)
4928 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
4933 seq_retry = ext4_get_discard_pa_seq_sum();
4934 if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) {
4935 ac->ac_flags |= EXT4_MB_STRICT_CHECK;
4941 mb_debug(sb, "freed %d, retry ? %s\n", freed, ret ? "yes" : "no");
4945 static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle,
4946 struct ext4_allocation_request *ar, int *errp);
4949 * Main entry point into mballoc to allocate blocks
4950 * it tries to use preallocation first, then falls back
4951 * to usual allocation
4953 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4954 struct ext4_allocation_request *ar, int *errp)
4956 struct ext4_allocation_context *ac = NULL;
4957 struct ext4_sb_info *sbi;
4958 struct super_block *sb;
4959 ext4_fsblk_t block = 0;
4960 unsigned int inquota = 0;
4961 unsigned int reserv_clstrs = 0;
4966 sb = ar->inode->i_sb;
4969 trace_ext4_request_blocks(ar);
4970 if (sbi->s_mount_state & EXT4_FC_REPLAY)
4971 return ext4_mb_new_blocks_simple(handle, ar, errp);
4973 /* Allow to use superuser reservation for quota file */
4974 if (ext4_is_quota_file(ar->inode))
4975 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
4977 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
4978 /* Without delayed allocation we need to verify
4979 * there is enough free blocks to do block allocation
4980 * and verify allocation doesn't exceed the quota limits.
4983 ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
4985 /* let others to free the space */
4987 ar->len = ar->len >> 1;
4990 ext4_mb_show_pa(sb);
4994 reserv_clstrs = ar->len;
4995 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
4996 dquot_alloc_block_nofail(ar->inode,
4997 EXT4_C2B(sbi, ar->len));
5000 dquot_alloc_block(ar->inode,
5001 EXT4_C2B(sbi, ar->len))) {
5003 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
5014 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
5021 *errp = ext4_mb_initialize_context(ac, ar);
5027 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
5028 seq = this_cpu_read(discard_pa_seq);
5029 if (!ext4_mb_use_preallocated(ac)) {
5030 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
5031 ext4_mb_normalize_request(ac, ar);
5033 *errp = ext4_mb_pa_alloc(ac);
5037 /* allocate space in core */
5038 *errp = ext4_mb_regular_allocator(ac);
5040 * pa allocated above is added to grp->bb_prealloc_list only
5041 * when we were able to allocate some block i.e. when
5042 * ac->ac_status == AC_STATUS_FOUND.
5043 * And error from above mean ac->ac_status != AC_STATUS_FOUND
5044 * So we have to free this pa here itself.
5047 ext4_mb_pa_free(ac);
5048 ext4_discard_allocated_blocks(ac);
5051 if (ac->ac_status == AC_STATUS_FOUND &&
5052 ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len)
5053 ext4_mb_pa_free(ac);
5055 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
5056 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
5058 ext4_discard_allocated_blocks(ac);
5061 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
5062 ar->len = ac->ac_b_ex.fe_len;
5065 if (++retries < 3 &&
5066 ext4_mb_discard_preallocations_should_retry(sb, ac, &seq))
5069 * If block allocation fails then the pa allocated above
5070 * needs to be freed here itself.
5072 ext4_mb_pa_free(ac);
5078 ac->ac_b_ex.fe_len = 0;
5080 ext4_mb_show_ac(ac);
5082 ext4_mb_release_context(ac);
5085 kmem_cache_free(ext4_ac_cachep, ac);
5086 if (inquota && ar->len < inquota)
5087 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
5089 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
5090 /* release all the reserved blocks if non delalloc */
5091 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
5095 trace_ext4_allocate_blocks(ar, (unsigned long long)block);
5101 * We can merge two free data extents only if the physical blocks
5102 * are contiguous, AND the extents were freed by the same transaction,
5103 * AND the blocks are associated with the same group.
5105 static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
5106 struct ext4_free_data *entry,
5107 struct ext4_free_data *new_entry,
5108 struct rb_root *entry_rb_root)
5110 if ((entry->efd_tid != new_entry->efd_tid) ||
5111 (entry->efd_group != new_entry->efd_group))
5113 if (entry->efd_start_cluster + entry->efd_count ==
5114 new_entry->efd_start_cluster) {
5115 new_entry->efd_start_cluster = entry->efd_start_cluster;
5116 new_entry->efd_count += entry->efd_count;
5117 } else if (new_entry->efd_start_cluster + new_entry->efd_count ==
5118 entry->efd_start_cluster) {
5119 new_entry->efd_count += entry->efd_count;
5122 spin_lock(&sbi->s_md_lock);
5123 list_del(&entry->efd_list);
5124 spin_unlock(&sbi->s_md_lock);
5125 rb_erase(&entry->efd_node, entry_rb_root);
5126 kmem_cache_free(ext4_free_data_cachep, entry);
5129 static noinline_for_stack int
5130 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
5131 struct ext4_free_data *new_entry)
5133 ext4_group_t group = e4b->bd_group;
5134 ext4_grpblk_t cluster;
5135 ext4_grpblk_t clusters = new_entry->efd_count;
5136 struct ext4_free_data *entry;
5137 struct ext4_group_info *db = e4b->bd_info;
5138 struct super_block *sb = e4b->bd_sb;
5139 struct ext4_sb_info *sbi = EXT4_SB(sb);
5140 struct rb_node **n = &db->bb_free_root.rb_node, *node;
5141 struct rb_node *parent = NULL, *new_node;
5143 BUG_ON(!ext4_handle_valid(handle));
5144 BUG_ON(e4b->bd_bitmap_page == NULL);
5145 BUG_ON(e4b->bd_buddy_page == NULL);
5147 new_node = &new_entry->efd_node;
5148 cluster = new_entry->efd_start_cluster;
5151 /* first free block exent. We need to
5152 protect buddy cache from being freed,
5153 * otherwise we'll refresh it from
5154 * on-disk bitmap and lose not-yet-available
5156 get_page(e4b->bd_buddy_page);
5157 get_page(e4b->bd_bitmap_page);
5161 entry = rb_entry(parent, struct ext4_free_data, efd_node);
5162 if (cluster < entry->efd_start_cluster)
5164 else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
5165 n = &(*n)->rb_right;
5167 ext4_grp_locked_error(sb, group, 0,
5168 ext4_group_first_block_no(sb, group) +
5169 EXT4_C2B(sbi, cluster),
5170 "Block already on to-be-freed list");
5171 kmem_cache_free(ext4_free_data_cachep, new_entry);
5176 rb_link_node(new_node, parent, n);
5177 rb_insert_color(new_node, &db->bb_free_root);
5179 /* Now try to see the extent can be merged to left and right */
5180 node = rb_prev(new_node);
5182 entry = rb_entry(node, struct ext4_free_data, efd_node);
5183 ext4_try_merge_freed_extent(sbi, entry, new_entry,
5184 &(db->bb_free_root));
5187 node = rb_next(new_node);
5189 entry = rb_entry(node, struct ext4_free_data, efd_node);
5190 ext4_try_merge_freed_extent(sbi, entry, new_entry,
5191 &(db->bb_free_root));
5194 spin_lock(&sbi->s_md_lock);
5195 list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list);
5196 sbi->s_mb_free_pending += clusters;
5197 spin_unlock(&sbi->s_md_lock);
5202 * Simple allocator for Ext4 fast commit replay path. It searches for blocks
5203 * linearly starting at the goal block and also excludes the blocks which
5204 * are going to be in use after fast commit replay.
5206 static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle,
5207 struct ext4_allocation_request *ar, int *errp)
5209 struct buffer_head *bitmap_bh;
5210 struct super_block *sb = ar->inode->i_sb;
5212 ext4_grpblk_t blkoff;
5213 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
5214 ext4_grpblk_t i = 0;
5215 ext4_fsblk_t goal, block;
5216 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5219 if (goal < le32_to_cpu(es->s_first_data_block) ||
5220 goal >= ext4_blocks_count(es))
5221 goal = le32_to_cpu(es->s_first_data_block);
5224 ext4_get_group_no_and_offset(sb, goal, &group, &blkoff);
5225 for (; group < ext4_get_groups_count(sb); group++) {
5226 bitmap_bh = ext4_read_block_bitmap(sb, group);
5227 if (IS_ERR(bitmap_bh)) {
5228 *errp = PTR_ERR(bitmap_bh);
5229 pr_warn("Failed to read block bitmap\n");
5233 ext4_get_group_no_and_offset(sb,
5234 max(ext4_group_first_block_no(sb, group), goal),
5237 i = mb_find_next_zero_bit(bitmap_bh->b_data, max,
5241 if (ext4_fc_replay_check_excluded(sb,
5242 ext4_group_first_block_no(sb, group) + i)) {
5252 if (group >= ext4_get_groups_count(sb) || i >= max) {
5257 block = ext4_group_first_block_no(sb, group) + i;
5258 ext4_mb_mark_bb(sb, block, 1, 1);
5264 static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
5265 unsigned long count)
5267 struct buffer_head *bitmap_bh;
5268 struct super_block *sb = inode->i_sb;
5269 struct ext4_group_desc *gdp;
5270 struct buffer_head *gdp_bh;
5272 ext4_grpblk_t blkoff;
5273 int already_freed = 0, err, i;
5275 ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
5276 bitmap_bh = ext4_read_block_bitmap(sb, group);
5277 if (IS_ERR(bitmap_bh)) {
5278 err = PTR_ERR(bitmap_bh);
5279 pr_warn("Failed to read block bitmap\n");
5282 gdp = ext4_get_group_desc(sb, group, &gdp_bh);
5286 for (i = 0; i < count; i++) {
5287 if (!mb_test_bit(blkoff + i, bitmap_bh->b_data))
5290 mb_clear_bits(bitmap_bh->b_data, blkoff, count);
5291 err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh);
5294 ext4_free_group_clusters_set(
5295 sb, gdp, ext4_free_group_clusters(sb, gdp) +
5296 count - already_freed);
5297 ext4_block_bitmap_csum_set(sb, group, gdp, bitmap_bh);
5298 ext4_group_desc_csum_set(sb, group, gdp);
5299 ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
5300 sync_dirty_buffer(bitmap_bh);
5301 sync_dirty_buffer(gdp_bh);
5306 * ext4_free_blocks() -- Free given blocks and update quota
5307 * @handle: handle for this transaction
5309 * @bh: optional buffer of the block to be freed
5310 * @block: starting physical block to be freed
5311 * @count: number of blocks to be freed
5312 * @flags: flags used by ext4_free_blocks
5314 void ext4_free_blocks(handle_t *handle, struct inode *inode,
5315 struct buffer_head *bh, ext4_fsblk_t block,
5316 unsigned long count, int flags)
5318 struct buffer_head *bitmap_bh = NULL;
5319 struct super_block *sb = inode->i_sb;
5320 struct ext4_group_desc *gdp;
5321 unsigned int overflow;
5323 struct buffer_head *gd_bh;
5324 ext4_group_t block_group;
5325 struct ext4_sb_info *sbi;
5326 struct ext4_buddy e4b;
5327 unsigned int count_clusters;
5333 if (sbi->s_mount_state & EXT4_FC_REPLAY) {
5334 ext4_free_blocks_simple(inode, block, count);
5341 BUG_ON(block != bh->b_blocknr);
5343 block = bh->b_blocknr;
5346 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
5347 !ext4_inode_block_valid(inode, block, count)) {
5348 ext4_error(sb, "Freeing blocks not in datazone - "
5349 "block = %llu, count = %lu", block, count);
5353 ext4_debug("freeing block %llu\n", block);
5354 trace_ext4_free_blocks(inode, block, count, flags);
5356 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
5359 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
5364 * If the extent to be freed does not begin on a cluster
5365 * boundary, we need to deal with partial clusters at the
5366 * beginning and end of the extent. Normally we will free
5367 * blocks at the beginning or the end unless we are explicitly
5368 * requested to avoid doing so.
5370 overflow = EXT4_PBLK_COFF(sbi, block);
5372 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
5373 overflow = sbi->s_cluster_ratio - overflow;
5375 if (count > overflow)
5384 overflow = EXT4_LBLK_COFF(sbi, count);
5386 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
5387 if (count > overflow)
5392 count += sbi->s_cluster_ratio - overflow;
5395 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
5397 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
5399 for (i = 0; i < count; i++) {
5402 bh = sb_find_get_block(inode->i_sb, block + i);
5403 ext4_forget(handle, is_metadata, inode, bh, block + i);
5409 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
5411 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
5412 ext4_get_group_info(sb, block_group))))
5416 * Check to see if we are freeing blocks across a group
5419 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
5420 overflow = EXT4_C2B(sbi, bit) + count -
5421 EXT4_BLOCKS_PER_GROUP(sb);
5424 count_clusters = EXT4_NUM_B2C(sbi, count);
5425 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
5426 if (IS_ERR(bitmap_bh)) {
5427 err = PTR_ERR(bitmap_bh);
5431 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
5437 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
5438 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
5439 in_range(block, ext4_inode_table(sb, gdp),
5440 sbi->s_itb_per_group) ||
5441 in_range(block + count - 1, ext4_inode_table(sb, gdp),
5442 sbi->s_itb_per_group)) {
5444 ext4_error(sb, "Freeing blocks in system zone - "
5445 "Block = %llu, count = %lu", block, count);
5446 /* err = 0. ext4_std_error should be a no op */
5450 BUFFER_TRACE(bitmap_bh, "getting write access");
5451 err = ext4_journal_get_write_access(handle, bitmap_bh);
5456 * We are about to modify some metadata. Call the journal APIs
5457 * to unshare ->b_data if a currently-committing transaction is
5460 BUFFER_TRACE(gd_bh, "get_write_access");
5461 err = ext4_journal_get_write_access(handle, gd_bh);
5464 #ifdef AGGRESSIVE_CHECK
5467 for (i = 0; i < count_clusters; i++)
5468 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
5471 trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters);
5473 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
5474 err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b,
5475 GFP_NOFS|__GFP_NOFAIL);
5480 * We need to make sure we don't reuse the freed block until after the
5481 * transaction is committed. We make an exception if the inode is to be
5482 * written in writeback mode since writeback mode has weak data
5483 * consistency guarantees.
5485 if (ext4_handle_valid(handle) &&
5486 ((flags & EXT4_FREE_BLOCKS_METADATA) ||
5487 !ext4_should_writeback_data(inode))) {
5488 struct ext4_free_data *new_entry;
5490 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
5493 new_entry = kmem_cache_alloc(ext4_free_data_cachep,
5494 GFP_NOFS|__GFP_NOFAIL);
5495 new_entry->efd_start_cluster = bit;
5496 new_entry->efd_group = block_group;
5497 new_entry->efd_count = count_clusters;
5498 new_entry->efd_tid = handle->h_transaction->t_tid;
5500 ext4_lock_group(sb, block_group);
5501 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
5502 ext4_mb_free_metadata(handle, &e4b, new_entry);
5504 /* need to update group_info->bb_free and bitmap
5505 * with group lock held. generate_buddy look at
5506 * them with group lock_held
5508 if (test_opt(sb, DISCARD)) {
5509 err = ext4_issue_discard(sb, block_group, bit, count,
5511 if (err && err != -EOPNOTSUPP)
5512 ext4_msg(sb, KERN_WARNING, "discard request in"
5513 " group:%d block:%d count:%lu failed"
5514 " with %d", block_group, bit, count,
5517 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
5519 ext4_lock_group(sb, block_group);
5520 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
5521 mb_free_blocks(inode, &e4b, bit, count_clusters);
5524 ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
5525 ext4_free_group_clusters_set(sb, gdp, ret);
5526 ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
5527 ext4_group_desc_csum_set(sb, block_group, gdp);
5528 ext4_unlock_group(sb, block_group);
5530 if (sbi->s_log_groups_per_flex) {
5531 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
5532 atomic64_add(count_clusters,
5533 &sbi_array_rcu_deref(sbi, s_flex_groups,
5534 flex_group)->free_clusters);
5538 * on a bigalloc file system, defer the s_freeclusters_counter
5539 * update to the caller (ext4_remove_space and friends) so they
5540 * can determine if a cluster freed here should be rereserved
5542 if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
5543 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
5544 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
5545 percpu_counter_add(&sbi->s_freeclusters_counter,
5549 ext4_mb_unload_buddy(&e4b);
5551 /* We dirtied the bitmap block */
5552 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
5553 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
5555 /* And the group descriptor block */
5556 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
5557 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
5561 if (overflow && !err) {
5569 ext4_std_error(sb, err);
5574 * ext4_group_add_blocks() -- Add given blocks to an existing group
5575 * @handle: handle to this transaction
5577 * @block: start physical block to add to the block group
5578 * @count: number of blocks to free
5580 * This marks the blocks as free in the bitmap and buddy.
5582 int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
5583 ext4_fsblk_t block, unsigned long count)
5585 struct buffer_head *bitmap_bh = NULL;
5586 struct buffer_head *gd_bh;
5587 ext4_group_t block_group;
5590 struct ext4_group_desc *desc;
5591 struct ext4_sb_info *sbi = EXT4_SB(sb);
5592 struct ext4_buddy e4b;
5593 int err = 0, ret, free_clusters_count;
5594 ext4_grpblk_t clusters_freed;
5595 ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
5596 ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
5597 unsigned long cluster_count = last_cluster - first_cluster + 1;
5599 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
5604 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
5606 * Check to see if we are freeing blocks across a group
5609 if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
5610 ext4_warning(sb, "too many blocks added to group %u",
5616 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
5617 if (IS_ERR(bitmap_bh)) {
5618 err = PTR_ERR(bitmap_bh);
5623 desc = ext4_get_group_desc(sb, block_group, &gd_bh);
5629 if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
5630 in_range(ext4_inode_bitmap(sb, desc), block, count) ||
5631 in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
5632 in_range(block + count - 1, ext4_inode_table(sb, desc),
5633 sbi->s_itb_per_group)) {
5634 ext4_error(sb, "Adding blocks in system zones - "
5635 "Block = %llu, count = %lu",
5641 BUFFER_TRACE(bitmap_bh, "getting write access");
5642 err = ext4_journal_get_write_access(handle, bitmap_bh);
5647 * We are about to modify some metadata. Call the journal APIs
5648 * to unshare ->b_data if a currently-committing transaction is
5651 BUFFER_TRACE(gd_bh, "get_write_access");
5652 err = ext4_journal_get_write_access(handle, gd_bh);
5656 for (i = 0, clusters_freed = 0; i < cluster_count; i++) {
5657 BUFFER_TRACE(bitmap_bh, "clear bit");
5658 if (!mb_test_bit(bit + i, bitmap_bh->b_data)) {
5659 ext4_error(sb, "bit already cleared for block %llu",
5660 (ext4_fsblk_t)(block + i));
5661 BUFFER_TRACE(bitmap_bh, "bit already cleared");
5667 err = ext4_mb_load_buddy(sb, block_group, &e4b);
5672 * need to update group_info->bb_free and bitmap
5673 * with group lock held. generate_buddy look at
5674 * them with group lock_held
5676 ext4_lock_group(sb, block_group);
5677 mb_clear_bits(bitmap_bh->b_data, bit, cluster_count);
5678 mb_free_blocks(NULL, &e4b, bit, cluster_count);
5679 free_clusters_count = clusters_freed +
5680 ext4_free_group_clusters(sb, desc);
5681 ext4_free_group_clusters_set(sb, desc, free_clusters_count);
5682 ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
5683 ext4_group_desc_csum_set(sb, block_group, desc);
5684 ext4_unlock_group(sb, block_group);
5685 percpu_counter_add(&sbi->s_freeclusters_counter,
5688 if (sbi->s_log_groups_per_flex) {
5689 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
5690 atomic64_add(clusters_freed,
5691 &sbi_array_rcu_deref(sbi, s_flex_groups,
5692 flex_group)->free_clusters);
5695 ext4_mb_unload_buddy(&e4b);
5697 /* We dirtied the bitmap block */
5698 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
5699 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
5701 /* And the group descriptor block */
5702 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
5703 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
5709 ext4_std_error(sb, err);
5714 * ext4_trim_extent -- function to TRIM one single free extent in the group
5715 * @sb: super block for the file system
5716 * @start: starting block of the free extent in the alloc. group
5717 * @count: number of blocks to TRIM
5718 * @group: alloc. group we are working with
5719 * @e4b: ext4 buddy for the group
5721 * Trim "count" blocks starting at "start" in the "group". To assure that no
5722 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5723 * be called with under the group lock.
5725 static int ext4_trim_extent(struct super_block *sb, int start, int count,
5726 ext4_group_t group, struct ext4_buddy *e4b)
5730 struct ext4_free_extent ex;
5733 trace_ext4_trim_extent(sb, group, start, count);
5735 assert_spin_locked(ext4_group_lock_ptr(sb, group));
5737 ex.fe_start = start;
5738 ex.fe_group = group;
5742 * Mark blocks used, so no one can reuse them while
5745 mb_mark_used(e4b, &ex);
5746 ext4_unlock_group(sb, group);
5747 ret = ext4_issue_discard(sb, group, start, count, NULL);
5748 ext4_lock_group(sb, group);
5749 mb_free_blocks(NULL, e4b, start, ex.fe_len);
5754 * ext4_trim_all_free -- function to trim all free space in alloc. group
5755 * @sb: super block for file system
5756 * @group: group to be trimmed
5757 * @start: first group block to examine
5758 * @max: last group block to examine
5759 * @minblocks: minimum extent block count
5761 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5762 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5766 * ext4_trim_all_free walks through group's block bitmap searching for free
5767 * extents. When the free extent is found, mark it as used in group buddy
5768 * bitmap. Then issue a TRIM command on this extent and free the extent in
5769 * the group buddy bitmap. This is done until whole group is scanned.
5771 static ext4_grpblk_t
5772 ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
5773 ext4_grpblk_t start, ext4_grpblk_t max,
5774 ext4_grpblk_t minblocks)
5777 ext4_grpblk_t next, count = 0, free_count = 0;
5778 struct ext4_buddy e4b;
5781 trace_ext4_trim_all_free(sb, group, start, max);
5783 ret = ext4_mb_load_buddy(sb, group, &e4b);
5785 ext4_warning(sb, "Error %d loading buddy information for %u",
5789 bitmap = e4b.bd_bitmap;
5791 ext4_lock_group(sb, group);
5792 if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
5793 minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
5796 start = (e4b.bd_info->bb_first_free > start) ?
5797 e4b.bd_info->bb_first_free : start;
5799 while (start <= max) {
5800 start = mb_find_next_zero_bit(bitmap, max + 1, start);
5803 next = mb_find_next_bit(bitmap, max + 1, start);
5805 if ((next - start) >= minblocks) {
5806 ret = ext4_trim_extent(sb, start,
5807 next - start, group, &e4b);
5808 if (ret && ret != -EOPNOTSUPP)
5811 count += next - start;
5813 free_count += next - start;
5816 if (fatal_signal_pending(current)) {
5817 count = -ERESTARTSYS;
5821 if (need_resched()) {
5822 ext4_unlock_group(sb, group);
5824 ext4_lock_group(sb, group);
5827 if ((e4b.bd_info->bb_free - free_count) < minblocks)
5833 EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
5836 ext4_unlock_group(sb, group);
5837 ext4_mb_unload_buddy(&e4b);
5839 ext4_debug("trimmed %d blocks in the group %d\n",
5846 * ext4_trim_fs() -- trim ioctl handle function
5847 * @sb: superblock for filesystem
5848 * @range: fstrim_range structure
5850 * start: First Byte to trim
5851 * len: number of Bytes to trim from start
5852 * minlen: minimum extent length in Bytes
5853 * ext4_trim_fs goes through all allocation groups containing Bytes from
5854 * start to start+len. For each such a group ext4_trim_all_free function
5855 * is invoked to trim all free space.
5857 int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
5859 struct request_queue *q = bdev_get_queue(sb->s_bdev);
5860 struct ext4_group_info *grp;
5861 ext4_group_t group, first_group, last_group;
5862 ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
5863 uint64_t start, end, minlen, trimmed = 0;
5864 ext4_fsblk_t first_data_blk =
5865 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
5866 ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es);
5869 start = range->start >> sb->s_blocksize_bits;
5870 end = start + (range->len >> sb->s_blocksize_bits) - 1;
5871 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
5872 range->minlen >> sb->s_blocksize_bits);
5874 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
5875 start >= max_blks ||
5876 range->len < sb->s_blocksize)
5878 /* No point to try to trim less than discard granularity */
5879 if (range->minlen < q->limits.discard_granularity) {
5880 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
5881 q->limits.discard_granularity >> sb->s_blocksize_bits);
5882 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb))
5885 if (end >= max_blks)
5887 if (end <= first_data_blk)
5889 if (start < first_data_blk)
5890 start = first_data_blk;
5892 /* Determine first and last group to examine based on start and end */
5893 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,
5894 &first_group, &first_cluster);
5895 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end,
5896 &last_group, &last_cluster);
5898 /* end now represents the last cluster to discard in this group */
5899 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5901 for (group = first_group; group <= last_group; group++) {
5902 grp = ext4_get_group_info(sb, group);
5903 /* We only do this if the grp has never been initialized */
5904 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
5905 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
5911 * For all the groups except the last one, last cluster will
5912 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5913 * change it for the last group, note that last_cluster is
5914 * already computed earlier by ext4_get_group_no_and_offset()
5916 if (group == last_group)
5919 if (grp->bb_free >= minlen) {
5920 cnt = ext4_trim_all_free(sb, group, first_cluster,
5930 * For every group except the first one, we are sure
5931 * that the first cluster to discard will be cluster #0.
5937 atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
5940 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
5944 /* Iterate all the free extents in the group. */
5946 ext4_mballoc_query_range(
5947 struct super_block *sb,
5949 ext4_grpblk_t start,
5951 ext4_mballoc_query_range_fn formatter,
5956 struct ext4_buddy e4b;
5959 error = ext4_mb_load_buddy(sb, group, &e4b);
5962 bitmap = e4b.bd_bitmap;
5964 ext4_lock_group(sb, group);
5966 start = (e4b.bd_info->bb_first_free > start) ?
5967 e4b.bd_info->bb_first_free : start;
5968 if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
5969 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5971 while (start <= end) {
5972 start = mb_find_next_zero_bit(bitmap, end + 1, start);
5975 next = mb_find_next_bit(bitmap, end + 1, start);
5977 ext4_unlock_group(sb, group);
5978 error = formatter(sb, group, start, next - start, priv);
5981 ext4_lock_group(sb, group);
5986 ext4_unlock_group(sb, group);
5988 ext4_mb_unload_buddy(&e4b);