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>
21 #ifdef CONFIG_EXT4_DEBUG
22 ushort ext4_mballoc_debug __read_mostly;
24 module_param_named(mballoc_debug, ext4_mballoc_debug, ushort, 0644);
25 MODULE_PARM_DESC(mballoc_debug, "Debugging level for ext4's mballoc");
30 * - test ext4_ext_search_left() and ext4_ext_search_right()
31 * - search for metadata in few groups
34 * - normalization should take into account whether file is still open
35 * - discard preallocations if no free space left (policy?)
36 * - don't normalize tails
38 * - reservation for superuser
41 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
42 * - track min/max extents in each group for better group selection
43 * - mb_mark_used() may allocate chunk right after splitting buddy
44 * - tree of groups sorted by number of free blocks
49 * The allocation request involve request for multiple number of blocks
50 * near to the goal(block) value specified.
52 * During initialization phase of the allocator we decide to use the
53 * group preallocation or inode preallocation depending on the size of
54 * the file. The size of the file could be the resulting file size we
55 * would have after allocation, or the current file size, which ever
56 * is larger. If the size is less than sbi->s_mb_stream_request we
57 * select to use the group preallocation. The default value of
58 * s_mb_stream_request is 16 blocks. This can also be tuned via
59 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
60 * terms of number of blocks.
62 * The main motivation for having small file use group preallocation is to
63 * ensure that we have small files closer together on the disk.
65 * First stage the allocator looks at the inode prealloc list,
66 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
67 * spaces for this particular inode. The inode prealloc space is
70 * pa_lstart -> the logical start block for this prealloc space
71 * pa_pstart -> the physical start block for this prealloc space
72 * pa_len -> length for this prealloc space (in clusters)
73 * pa_free -> free space available in this prealloc space (in clusters)
75 * The inode preallocation space is used looking at the _logical_ start
76 * block. If only the logical file block falls within the range of prealloc
77 * space we will consume the particular prealloc space. This makes sure that
78 * we have contiguous physical blocks representing the file blocks
80 * The important thing to be noted in case of inode prealloc space is that
81 * we don't modify the values associated to inode prealloc space except
84 * If we are not able to find blocks in the inode prealloc space and if we
85 * have the group allocation flag set then we look at the locality group
86 * prealloc space. These are per CPU prealloc list represented as
88 * ext4_sb_info.s_locality_groups[smp_processor_id()]
90 * The reason for having a per cpu locality group is to reduce the contention
91 * between CPUs. It is possible to get scheduled at this point.
93 * The locality group prealloc space is used looking at whether we have
94 * enough free space (pa_free) within the prealloc space.
96 * If we can't allocate blocks via inode prealloc or/and locality group
97 * prealloc then we look at the buddy cache. The buddy cache is represented
98 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
99 * mapped to the buddy and bitmap information regarding different
100 * groups. The buddy information is attached to buddy cache inode so that
101 * we can access them through the page cache. The information regarding
102 * each group is loaded via ext4_mb_load_buddy. The information involve
103 * block bitmap and buddy information. The information are stored in the
107 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
110 * one block each for bitmap and buddy information. So for each group we
111 * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
112 * blocksize) blocks. So it can have information regarding groups_per_page
113 * which is blocks_per_page/2
115 * The buddy cache inode is not stored on disk. The inode is thrown
116 * away when the filesystem is unmounted.
118 * We look for count number of blocks in the buddy cache. If we were able
119 * to locate that many free blocks we return with additional information
120 * regarding rest of the contiguous physical block available
122 * Before allocating blocks via buddy cache we normalize the request
123 * blocks. This ensure we ask for more blocks that we needed. The extra
124 * blocks that we get after allocation is added to the respective prealloc
125 * list. In case of inode preallocation we follow a list of heuristics
126 * based on file size. This can be found in ext4_mb_normalize_request. If
127 * we are doing a group prealloc we try to normalize the request to
128 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
129 * dependent on the cluster size; for non-bigalloc file systems, it is
130 * 512 blocks. This can be tuned via
131 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
132 * terms of number of blocks. If we have mounted the file system with -O
133 * stripe=<value> option the group prealloc request is normalized to the
134 * the smallest multiple of the stripe value (sbi->s_stripe) which is
135 * greater than the default mb_group_prealloc.
137 * The regular allocator (using the buddy cache) supports a few tunables.
139 * /sys/fs/ext4/<partition>/mb_min_to_scan
140 * /sys/fs/ext4/<partition>/mb_max_to_scan
141 * /sys/fs/ext4/<partition>/mb_order2_req
143 * The regular allocator uses buddy scan only if the request len is power of
144 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
145 * value of s_mb_order2_reqs can be tuned via
146 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
147 * stripe size (sbi->s_stripe), we try to search for contiguous block in
148 * stripe size. This should result in better allocation on RAID setups. If
149 * not, we search in the specific group using bitmap for best extents. The
150 * tunable min_to_scan and max_to_scan control the behaviour here.
151 * min_to_scan indicate how long the mballoc __must__ look for a best
152 * extent and max_to_scan indicates how long the mballoc __can__ look for a
153 * best extent in the found extents. Searching for the blocks starts with
154 * the group specified as the goal value in allocation context via
155 * ac_g_ex. Each group is first checked based on the criteria whether it
156 * can be used for allocation. ext4_mb_good_group explains how the groups are
159 * Both the prealloc space are getting populated as above. So for the first
160 * request we will hit the buddy cache which will result in this prealloc
161 * space getting filled. The prealloc space is then later used for the
162 * subsequent request.
166 * mballoc operates on the following data:
168 * - in-core buddy (actually includes buddy and bitmap)
169 * - preallocation descriptors (PAs)
171 * there are two types of preallocations:
173 * assiged to specific inode and can be used for this inode only.
174 * it describes part of inode's space preallocated to specific
175 * physical blocks. any block from that preallocated can be used
176 * independent. the descriptor just tracks number of blocks left
177 * unused. so, before taking some block from descriptor, one must
178 * make sure corresponded logical block isn't allocated yet. this
179 * also means that freeing any block within descriptor's range
180 * must discard all preallocated blocks.
182 * assigned to specific locality group which does not translate to
183 * permanent set of inodes: inode can join and leave group. space
184 * from this type of preallocation can be used for any inode. thus
185 * it's consumed from the beginning to the end.
187 * relation between them can be expressed as:
188 * in-core buddy = on-disk bitmap + preallocation descriptors
190 * this mean blocks mballoc considers used are:
191 * - allocated blocks (persistent)
192 * - preallocated blocks (non-persistent)
194 * consistency in mballoc world means that at any time a block is either
195 * free or used in ALL structures. notice: "any time" should not be read
196 * literally -- time is discrete and delimited by locks.
198 * to keep it simple, we don't use block numbers, instead we count number of
199 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
201 * all operations can be expressed as:
202 * - init buddy: buddy = on-disk + PAs
203 * - new PA: buddy += N; PA = N
204 * - use inode PA: on-disk += N; PA -= N
205 * - discard inode PA buddy -= on-disk - PA; PA = 0
206 * - use locality group PA on-disk += N; PA -= N
207 * - discard locality group PA buddy -= PA; PA = 0
208 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
209 * is used in real operation because we can't know actual used
210 * bits from PA, only from on-disk bitmap
212 * if we follow this strict logic, then all operations above should be atomic.
213 * given some of them can block, we'd have to use something like semaphores
214 * killing performance on high-end SMP hardware. let's try to relax it using
215 * the following knowledge:
216 * 1) if buddy is referenced, it's already initialized
217 * 2) while block is used in buddy and the buddy is referenced,
218 * nobody can re-allocate that block
219 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
220 * bit set and PA claims same block, it's OK. IOW, one can set bit in
221 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
224 * so, now we're building a concurrency table:
227 * blocks for PA are allocated in the buddy, buddy must be referenced
228 * until PA is linked to allocation group to avoid concurrent buddy init
230 * we need to make sure that either on-disk bitmap or PA has uptodate data
231 * given (3) we care that PA-=N operation doesn't interfere with init
233 * the simplest way would be to have buddy initialized by the discard
234 * - use locality group PA
235 * again PA-=N must be serialized with init
236 * - discard locality group PA
237 * the simplest way would be to have buddy initialized by the discard
240 * i_data_sem serializes them
242 * discard process must wait until PA isn't used by another process
243 * - use locality group PA
244 * some mutex should serialize them
245 * - discard locality group PA
246 * discard process must wait until PA isn't used by another process
249 * i_data_sem or another mutex should serializes them
251 * discard process must wait until PA isn't used by another process
252 * - use locality group PA
253 * nothing wrong here -- they're different PAs covering different blocks
254 * - discard locality group PA
255 * discard process must wait until PA isn't used by another process
257 * now we're ready to make few consequences:
258 * - PA is referenced and while it is no discard is possible
259 * - PA is referenced until block isn't marked in on-disk bitmap
260 * - PA changes only after on-disk bitmap
261 * - discard must not compete with init. either init is done before
262 * any discard or they're serialized somehow
263 * - buddy init as sum of on-disk bitmap and PAs is done atomically
265 * a special case when we've used PA to emptiness. no need to modify buddy
266 * in this case, but we should care about concurrent init
271 * Logic in few words:
276 * mark bits in on-disk bitmap
279 * - use preallocation:
280 * find proper PA (per-inode or group)
282 * mark bits in on-disk bitmap
288 * mark bits in on-disk bitmap
291 * - discard preallocations in group:
293 * move them onto local list
294 * load on-disk bitmap
296 * remove PA from object (inode or locality group)
297 * mark free blocks in-core
299 * - discard inode's preallocations:
306 * - bitlock on a group (group)
307 * - object (inode/locality) (object)
318 * - release consumed pa:
323 * - generate in-core bitmap:
327 * - discard all for given object (inode, locality group):
332 * - discard all for given group:
339 static struct kmem_cache *ext4_pspace_cachep;
340 static struct kmem_cache *ext4_ac_cachep;
341 static struct kmem_cache *ext4_free_data_cachep;
343 /* We create slab caches for groupinfo data structures based on the
344 * superblock block size. There will be one per mounted filesystem for
345 * each unique s_blocksize_bits */
346 #define NR_GRPINFO_CACHES 8
347 static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
349 static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
350 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
351 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
352 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
355 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
357 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
360 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
362 #if BITS_PER_LONG == 64
363 *bit += ((unsigned long) addr & 7UL) << 3;
364 addr = (void *) ((unsigned long) addr & ~7UL);
365 #elif BITS_PER_LONG == 32
366 *bit += ((unsigned long) addr & 3UL) << 3;
367 addr = (void *) ((unsigned long) addr & ~3UL);
369 #error "how many bits you are?!"
374 static inline int mb_test_bit(int bit, void *addr)
377 * ext4_test_bit on architecture like powerpc
378 * needs unsigned long aligned address
380 addr = mb_correct_addr_and_bit(&bit, addr);
381 return ext4_test_bit(bit, addr);
384 static inline void mb_set_bit(int bit, void *addr)
386 addr = mb_correct_addr_and_bit(&bit, addr);
387 ext4_set_bit(bit, addr);
390 static inline void mb_clear_bit(int bit, void *addr)
392 addr = mb_correct_addr_and_bit(&bit, addr);
393 ext4_clear_bit(bit, addr);
396 static inline int mb_test_and_clear_bit(int bit, void *addr)
398 addr = mb_correct_addr_and_bit(&bit, addr);
399 return ext4_test_and_clear_bit(bit, addr);
402 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
404 int fix = 0, ret, tmpmax;
405 addr = mb_correct_addr_and_bit(&fix, addr);
409 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
415 static inline int mb_find_next_bit(void *addr, int max, int start)
417 int fix = 0, ret, tmpmax;
418 addr = mb_correct_addr_and_bit(&fix, addr);
422 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
428 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
432 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
435 if (order > e4b->bd_blkbits + 1) {
440 /* at order 0 we see each particular block */
442 *max = 1 << (e4b->bd_blkbits + 3);
443 return e4b->bd_bitmap;
446 bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
447 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
453 static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
454 int first, int count)
457 struct super_block *sb = e4b->bd_sb;
459 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
461 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
462 for (i = 0; i < count; i++) {
463 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
464 ext4_fsblk_t blocknr;
466 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
467 blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
468 ext4_grp_locked_error(sb, e4b->bd_group,
469 inode ? inode->i_ino : 0,
471 "freeing block already freed "
474 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
475 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
477 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
481 static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
485 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
487 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
488 for (i = 0; i < count; i++) {
489 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
490 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
494 static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
496 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
497 unsigned char *b1, *b2;
499 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
500 b2 = (unsigned char *) bitmap;
501 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
502 if (b1[i] != b2[i]) {
503 ext4_msg(e4b->bd_sb, KERN_ERR,
504 "corruption in group %u "
505 "at byte %u(%u): %x in copy != %x "
507 e4b->bd_group, i, i * 8, b1[i], b2[i]);
515 static inline void mb_free_blocks_double(struct inode *inode,
516 struct ext4_buddy *e4b, int first, int count)
520 static inline void mb_mark_used_double(struct ext4_buddy *e4b,
521 int first, int count)
525 static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
531 #ifdef AGGRESSIVE_CHECK
533 #define MB_CHECK_ASSERT(assert) \
537 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
538 function, file, line, # assert); \
543 static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
544 const char *function, int line)
546 struct super_block *sb = e4b->bd_sb;
547 int order = e4b->bd_blkbits + 1;
554 struct ext4_group_info *grp;
557 struct list_head *cur;
562 static int mb_check_counter;
563 if (mb_check_counter++ % 100 != 0)
568 buddy = mb_find_buddy(e4b, order, &max);
569 MB_CHECK_ASSERT(buddy);
570 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
571 MB_CHECK_ASSERT(buddy2);
572 MB_CHECK_ASSERT(buddy != buddy2);
573 MB_CHECK_ASSERT(max * 2 == max2);
576 for (i = 0; i < max; i++) {
578 if (mb_test_bit(i, buddy)) {
579 /* only single bit in buddy2 may be 1 */
580 if (!mb_test_bit(i << 1, buddy2)) {
582 mb_test_bit((i<<1)+1, buddy2));
583 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
585 mb_test_bit(i << 1, buddy2));
590 /* both bits in buddy2 must be 1 */
591 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
592 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
594 for (j = 0; j < (1 << order); j++) {
595 k = (i * (1 << order)) + j;
597 !mb_test_bit(k, e4b->bd_bitmap));
601 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
606 buddy = mb_find_buddy(e4b, 0, &max);
607 for (i = 0; i < max; i++) {
608 if (!mb_test_bit(i, buddy)) {
609 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
617 /* check used bits only */
618 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
619 buddy2 = mb_find_buddy(e4b, j, &max2);
621 MB_CHECK_ASSERT(k < max2);
622 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
625 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
626 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
628 grp = ext4_get_group_info(sb, e4b->bd_group);
629 list_for_each(cur, &grp->bb_prealloc_list) {
630 ext4_group_t groupnr;
631 struct ext4_prealloc_space *pa;
632 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
633 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
634 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
635 for (i = 0; i < pa->pa_len; i++)
636 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
640 #undef MB_CHECK_ASSERT
641 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
642 __FILE__, __func__, __LINE__)
644 #define mb_check_buddy(e4b)
648 * Divide blocks started from @first with length @len into
649 * smaller chunks with power of 2 blocks.
650 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
651 * then increase bb_counters[] for corresponded chunk size.
653 static void ext4_mb_mark_free_simple(struct super_block *sb,
654 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
655 struct ext4_group_info *grp)
657 struct ext4_sb_info *sbi = EXT4_SB(sb);
663 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
665 border = 2 << sb->s_blocksize_bits;
668 /* find how many blocks can be covered since this position */
669 max = ffs(first | border) - 1;
671 /* find how many blocks of power 2 we need to mark */
678 /* mark multiblock chunks only */
679 grp->bb_counters[min]++;
681 mb_clear_bit(first >> min,
682 buddy + sbi->s_mb_offsets[min]);
690 * Cache the order of the largest free extent we have available in this block
694 mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
699 grp->bb_largest_free_order = -1; /* uninit */
701 bits = sb->s_blocksize_bits + 1;
702 for (i = bits; i >= 0; i--) {
703 if (grp->bb_counters[i] > 0) {
704 grp->bb_largest_free_order = i;
710 static noinline_for_stack
711 void ext4_mb_generate_buddy(struct super_block *sb,
712 void *buddy, void *bitmap, ext4_group_t group)
714 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
715 struct ext4_sb_info *sbi = EXT4_SB(sb);
716 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
721 unsigned fragments = 0;
722 unsigned long long period = get_cycles();
724 /* initialize buddy from bitmap which is aggregation
725 * of on-disk bitmap and preallocations */
726 i = mb_find_next_zero_bit(bitmap, max, 0);
727 grp->bb_first_free = i;
731 i = mb_find_next_bit(bitmap, max, i);
735 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
737 grp->bb_counters[0]++;
739 i = mb_find_next_zero_bit(bitmap, max, i);
741 grp->bb_fragments = fragments;
743 if (free != grp->bb_free) {
744 ext4_grp_locked_error(sb, group, 0, 0,
745 "block bitmap and bg descriptor "
746 "inconsistent: %u vs %u free clusters",
749 * If we intend to continue, we consider group descriptor
750 * corrupt and update bb_free using bitmap value
753 ext4_mark_group_bitmap_corrupted(sb, group,
754 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
756 mb_set_largest_free_order(sb, grp);
758 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
760 period = get_cycles() - period;
761 spin_lock(&sbi->s_bal_lock);
762 sbi->s_mb_buddies_generated++;
763 sbi->s_mb_generation_time += period;
764 spin_unlock(&sbi->s_bal_lock);
767 static void mb_regenerate_buddy(struct ext4_buddy *e4b)
773 while ((buddy = mb_find_buddy(e4b, order++, &count))) {
774 ext4_set_bits(buddy, 0, count);
776 e4b->bd_info->bb_fragments = 0;
777 memset(e4b->bd_info->bb_counters, 0,
778 sizeof(*e4b->bd_info->bb_counters) *
779 (e4b->bd_sb->s_blocksize_bits + 2));
781 ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy,
782 e4b->bd_bitmap, e4b->bd_group);
785 /* The buddy information is attached the buddy cache inode
786 * for convenience. The information regarding each group
787 * is loaded via ext4_mb_load_buddy. The information involve
788 * block bitmap and buddy information. The information are
789 * stored in the inode as
792 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
795 * one block each for bitmap and buddy information.
796 * So for each group we take up 2 blocks. A page can
797 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
798 * So it can have information regarding groups_per_page which
799 * is blocks_per_page/2
801 * Locking note: This routine takes the block group lock of all groups
802 * for this page; do not hold this lock when calling this routine!
805 static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
807 ext4_group_t ngroups;
813 ext4_group_t first_group, group;
815 struct super_block *sb;
816 struct buffer_head *bhs;
817 struct buffer_head **bh = NULL;
821 struct ext4_group_info *grinfo;
823 mb_debug(1, "init page %lu\n", page->index);
825 inode = page->mapping->host;
827 ngroups = ext4_get_groups_count(sb);
828 blocksize = i_blocksize(inode);
829 blocks_per_page = PAGE_SIZE / blocksize;
831 groups_per_page = blocks_per_page >> 1;
832 if (groups_per_page == 0)
835 /* allocate buffer_heads to read bitmaps */
836 if (groups_per_page > 1) {
837 i = sizeof(struct buffer_head *) * groups_per_page;
838 bh = kzalloc(i, gfp);
846 first_group = page->index * blocks_per_page / 2;
848 /* read all groups the page covers into the cache */
849 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
850 if (group >= ngroups)
853 grinfo = ext4_get_group_info(sb, group);
855 * If page is uptodate then we came here after online resize
856 * which added some new uninitialized group info structs, so
857 * we must skip all initialized uptodate buddies on the page,
858 * which may be currently in use by an allocating task.
860 if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
864 bh[i] = ext4_read_block_bitmap_nowait(sb, group);
866 err = PTR_ERR(bh[i]);
870 mb_debug(1, "read bitmap for group %u\n", group);
873 /* wait for I/O completion */
874 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
879 err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
884 first_block = page->index * blocks_per_page;
885 for (i = 0; i < blocks_per_page; i++) {
886 group = (first_block + i) >> 1;
887 if (group >= ngroups)
890 if (!bh[group - first_group])
891 /* skip initialized uptodate buddy */
894 if (!buffer_verified(bh[group - first_group]))
895 /* Skip faulty bitmaps */
900 * data carry information regarding this
901 * particular group in the format specified
905 data = page_address(page) + (i * blocksize);
906 bitmap = bh[group - first_group]->b_data;
909 * We place the buddy block and bitmap block
912 if ((first_block + i) & 1) {
913 /* this is block of buddy */
914 BUG_ON(incore == NULL);
915 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
916 group, page->index, i * blocksize);
917 trace_ext4_mb_buddy_bitmap_load(sb, group);
918 grinfo = ext4_get_group_info(sb, group);
919 grinfo->bb_fragments = 0;
920 memset(grinfo->bb_counters, 0,
921 sizeof(*grinfo->bb_counters) *
922 (sb->s_blocksize_bits+2));
924 * incore got set to the group block bitmap below
926 ext4_lock_group(sb, group);
928 memset(data, 0xff, blocksize);
929 ext4_mb_generate_buddy(sb, data, incore, group);
930 ext4_unlock_group(sb, group);
933 /* this is block of bitmap */
934 BUG_ON(incore != NULL);
935 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
936 group, page->index, i * blocksize);
937 trace_ext4_mb_bitmap_load(sb, group);
939 /* see comments in ext4_mb_put_pa() */
940 ext4_lock_group(sb, group);
941 memcpy(data, bitmap, blocksize);
943 /* mark all preallocated blks used in in-core bitmap */
944 ext4_mb_generate_from_pa(sb, data, group);
945 ext4_mb_generate_from_freelist(sb, data, group);
946 ext4_unlock_group(sb, group);
948 /* set incore so that the buddy information can be
949 * generated using this
954 SetPageUptodate(page);
958 for (i = 0; i < groups_per_page; i++)
967 * Lock the buddy and bitmap pages. This make sure other parallel init_group
968 * on the same buddy page doesn't happen whild holding the buddy page lock.
969 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
970 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
972 static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
973 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
975 struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
976 int block, pnum, poff;
980 e4b->bd_buddy_page = NULL;
981 e4b->bd_bitmap_page = NULL;
983 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
985 * the buddy cache inode stores the block bitmap
986 * and buddy information in consecutive blocks.
987 * So for each group we need two blocks.
990 pnum = block / blocks_per_page;
991 poff = block % blocks_per_page;
992 page = find_or_create_page(inode->i_mapping, pnum, gfp);
995 BUG_ON(page->mapping != inode->i_mapping);
996 e4b->bd_bitmap_page = page;
997 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
999 if (blocks_per_page >= 2) {
1000 /* buddy and bitmap are on the same page */
1005 pnum = block / blocks_per_page;
1006 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1009 BUG_ON(page->mapping != inode->i_mapping);
1010 e4b->bd_buddy_page = page;
1014 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1016 if (e4b->bd_bitmap_page) {
1017 unlock_page(e4b->bd_bitmap_page);
1018 put_page(e4b->bd_bitmap_page);
1020 if (e4b->bd_buddy_page) {
1021 unlock_page(e4b->bd_buddy_page);
1022 put_page(e4b->bd_buddy_page);
1027 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1028 * block group lock of all groups for this page; do not hold the BG lock when
1029 * calling this routine!
1031 static noinline_for_stack
1032 int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1035 struct ext4_group_info *this_grp;
1036 struct ext4_buddy e4b;
1041 mb_debug(1, "init group %u\n", group);
1042 this_grp = ext4_get_group_info(sb, group);
1044 * This ensures that we don't reinit the buddy cache
1045 * page which map to the group from which we are already
1046 * allocating. If we are looking at the buddy cache we would
1047 * have taken a reference using ext4_mb_load_buddy and that
1048 * would have pinned buddy page to page cache.
1049 * The call to ext4_mb_get_buddy_page_lock will mark the
1052 ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp);
1053 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1055 * somebody initialized the group
1056 * return without doing anything
1061 page = e4b.bd_bitmap_page;
1062 ret = ext4_mb_init_cache(page, NULL, gfp);
1065 if (!PageUptodate(page)) {
1070 if (e4b.bd_buddy_page == NULL) {
1072 * If both the bitmap and buddy are in
1073 * the same page we don't need to force
1079 /* init buddy cache */
1080 page = e4b.bd_buddy_page;
1081 ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp);
1084 if (!PageUptodate(page)) {
1089 ext4_mb_put_buddy_page_lock(&e4b);
1094 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1095 * block group lock of all groups for this page; do not hold the BG lock when
1096 * calling this routine!
1098 static noinline_for_stack int
1099 ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1100 struct ext4_buddy *e4b, gfp_t gfp)
1102 int blocks_per_page;
1108 struct ext4_group_info *grp;
1109 struct ext4_sb_info *sbi = EXT4_SB(sb);
1110 struct inode *inode = sbi->s_buddy_cache;
1113 mb_debug(1, "load group %u\n", group);
1115 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1116 grp = ext4_get_group_info(sb, group);
1118 e4b->bd_blkbits = sb->s_blocksize_bits;
1121 e4b->bd_group = group;
1122 e4b->bd_buddy_page = NULL;
1123 e4b->bd_bitmap_page = NULL;
1125 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1127 * we need full data about the group
1128 * to make a good selection
1130 ret = ext4_mb_init_group(sb, group, gfp);
1136 * the buddy cache inode stores the block bitmap
1137 * and buddy information in consecutive blocks.
1138 * So for each group we need two blocks.
1141 pnum = block / blocks_per_page;
1142 poff = block % blocks_per_page;
1144 /* we could use find_or_create_page(), but it locks page
1145 * what we'd like to avoid in fast path ... */
1146 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1147 if (page == NULL || !PageUptodate(page)) {
1150 * drop the page reference and try
1151 * to get the page with lock. If we
1152 * are not uptodate that implies
1153 * somebody just created the page but
1154 * is yet to initialize the same. So
1155 * wait for it to initialize.
1158 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1160 BUG_ON(page->mapping != inode->i_mapping);
1161 if (!PageUptodate(page)) {
1162 ret = ext4_mb_init_cache(page, NULL, gfp);
1167 mb_cmp_bitmaps(e4b, page_address(page) +
1168 (poff * sb->s_blocksize));
1177 if (!PageUptodate(page)) {
1182 /* Pages marked accessed already */
1183 e4b->bd_bitmap_page = page;
1184 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1187 pnum = block / blocks_per_page;
1188 poff = block % blocks_per_page;
1190 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1191 if (page == NULL || !PageUptodate(page)) {
1194 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1196 BUG_ON(page->mapping != inode->i_mapping);
1197 if (!PageUptodate(page)) {
1198 ret = ext4_mb_init_cache(page, e4b->bd_bitmap,
1212 if (!PageUptodate(page)) {
1217 /* Pages marked accessed already */
1218 e4b->bd_buddy_page = page;
1219 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1221 BUG_ON(e4b->bd_bitmap_page == NULL);
1222 BUG_ON(e4b->bd_buddy_page == NULL);
1229 if (e4b->bd_bitmap_page)
1230 put_page(e4b->bd_bitmap_page);
1231 if (e4b->bd_buddy_page)
1232 put_page(e4b->bd_buddy_page);
1233 e4b->bd_buddy = NULL;
1234 e4b->bd_bitmap = NULL;
1238 static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1239 struct ext4_buddy *e4b)
1241 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1244 static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1246 if (e4b->bd_bitmap_page)
1247 put_page(e4b->bd_bitmap_page);
1248 if (e4b->bd_buddy_page)
1249 put_page(e4b->bd_buddy_page);
1253 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1256 int bb_incr = 1 << (e4b->bd_blkbits - 1);
1259 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1260 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1263 while (order <= e4b->bd_blkbits + 1) {
1265 if (!mb_test_bit(block, bb)) {
1266 /* this block is part of buddy of order 'order' */
1276 static void mb_clear_bits(void *bm, int cur, int len)
1282 if ((cur & 31) == 0 && (len - cur) >= 32) {
1283 /* fast path: clear whole word at once */
1284 addr = bm + (cur >> 3);
1289 mb_clear_bit(cur, bm);
1294 /* clear bits in given range
1295 * will return first found zero bit if any, -1 otherwise
1297 static int mb_test_and_clear_bits(void *bm, int cur, int len)
1304 if ((cur & 31) == 0 && (len - cur) >= 32) {
1305 /* fast path: clear whole word at once */
1306 addr = bm + (cur >> 3);
1307 if (*addr != (__u32)(-1) && zero_bit == -1)
1308 zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0);
1313 if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1)
1321 void ext4_set_bits(void *bm, int cur, int len)
1327 if ((cur & 31) == 0 && (len - cur) >= 32) {
1328 /* fast path: set whole word at once */
1329 addr = bm + (cur >> 3);
1334 mb_set_bit(cur, bm);
1340 * _________________________________________________________________ */
1342 static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1344 if (mb_test_bit(*bit + side, bitmap)) {
1345 mb_clear_bit(*bit, bitmap);
1351 mb_set_bit(*bit, bitmap);
1356 static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1360 void *buddy = mb_find_buddy(e4b, order, &max);
1365 /* Bits in range [first; last] are known to be set since
1366 * corresponding blocks were allocated. Bits in range
1367 * (first; last) will stay set because they form buddies on
1368 * upper layer. We just deal with borders if they don't
1369 * align with upper layer and then go up.
1370 * Releasing entire group is all about clearing
1371 * single bit of highest order buddy.
1375 * ---------------------------------
1377 * ---------------------------------
1378 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1379 * ---------------------------------
1381 * \_____________________/
1383 * Neither [1] nor [6] is aligned to above layer.
1384 * Left neighbour [0] is free, so mark it busy,
1385 * decrease bb_counters and extend range to
1387 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1388 * mark [6] free, increase bb_counters and shrink range to
1390 * Then shift range to [0; 2], go up and do the same.
1395 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1);
1397 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1);
1402 if (first == last || !(buddy2 = mb_find_buddy(e4b, order, &max))) {
1403 mb_clear_bits(buddy, first, last - first + 1);
1404 e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1413 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1414 int first, int count)
1416 int left_is_free = 0;
1417 int right_is_free = 0;
1419 int last = first + count - 1;
1420 struct super_block *sb = e4b->bd_sb;
1422 if (WARN_ON(count == 0))
1424 BUG_ON(last >= (sb->s_blocksize << 3));
1425 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1426 /* Don't bother if the block group is corrupt. */
1427 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1430 mb_check_buddy(e4b);
1431 mb_free_blocks_double(inode, e4b, first, count);
1433 e4b->bd_info->bb_free += count;
1434 if (first < e4b->bd_info->bb_first_free)
1435 e4b->bd_info->bb_first_free = first;
1437 /* access memory sequentially: check left neighbour,
1438 * clear range and then check right neighbour
1441 left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap);
1442 block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count);
1443 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1444 right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap);
1446 if (unlikely(block != -1)) {
1447 struct ext4_sb_info *sbi = EXT4_SB(sb);
1448 ext4_fsblk_t blocknr;
1450 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
1451 blocknr += EXT4_C2B(sbi, block);
1452 ext4_grp_locked_error(sb, e4b->bd_group,
1453 inode ? inode->i_ino : 0,
1455 "freeing already freed block "
1456 "(bit %u); block bitmap corrupt.",
1458 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
1459 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1460 mb_regenerate_buddy(e4b);
1464 /* let's maintain fragments counter */
1465 if (left_is_free && right_is_free)
1466 e4b->bd_info->bb_fragments--;
1467 else if (!left_is_free && !right_is_free)
1468 e4b->bd_info->bb_fragments++;
1470 /* buddy[0] == bd_bitmap is a special case, so handle
1471 * it right away and let mb_buddy_mark_free stay free of
1472 * zero order checks.
1473 * Check if neighbours are to be coaleasced,
1474 * adjust bitmap bb_counters and borders appropriately.
1477 first += !left_is_free;
1478 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
1481 last -= !right_is_free;
1482 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
1486 mb_buddy_mark_free(e4b, first >> 1, last >> 1);
1489 mb_set_largest_free_order(sb, e4b->bd_info);
1490 mb_check_buddy(e4b);
1493 static int mb_find_extent(struct ext4_buddy *e4b, int block,
1494 int needed, struct ext4_free_extent *ex)
1500 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1503 buddy = mb_find_buddy(e4b, 0, &max);
1504 BUG_ON(buddy == NULL);
1505 BUG_ON(block >= max);
1506 if (mb_test_bit(block, buddy)) {
1513 /* find actual order */
1514 order = mb_find_order_for_block(e4b, block);
1515 block = block >> order;
1517 ex->fe_len = 1 << order;
1518 ex->fe_start = block << order;
1519 ex->fe_group = e4b->bd_group;
1521 /* calc difference from given start */
1522 next = next - ex->fe_start;
1524 ex->fe_start += next;
1526 while (needed > ex->fe_len &&
1527 mb_find_buddy(e4b, order, &max)) {
1529 if (block + 1 >= max)
1532 next = (block + 1) * (1 << order);
1533 if (mb_test_bit(next, e4b->bd_bitmap))
1536 order = mb_find_order_for_block(e4b, next);
1538 block = next >> order;
1539 ex->fe_len += 1 << order;
1542 if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
1543 /* Should never happen! (but apparently sometimes does?!?) */
1545 ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0,
1546 "corruption or bug in mb_find_extent "
1547 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
1548 block, order, needed, ex->fe_group, ex->fe_start,
1549 ex->fe_len, ex->fe_logical);
1557 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1563 int start = ex->fe_start;
1564 int len = ex->fe_len;
1569 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1570 BUG_ON(e4b->bd_group != ex->fe_group);
1571 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1572 mb_check_buddy(e4b);
1573 mb_mark_used_double(e4b, start, len);
1575 e4b->bd_info->bb_free -= len;
1576 if (e4b->bd_info->bb_first_free == start)
1577 e4b->bd_info->bb_first_free += len;
1579 /* let's maintain fragments counter */
1581 mlen = !mb_test_bit(start - 1, e4b->bd_bitmap);
1582 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1583 max = !mb_test_bit(start + len, e4b->bd_bitmap);
1585 e4b->bd_info->bb_fragments++;
1586 else if (!mlen && !max)
1587 e4b->bd_info->bb_fragments--;
1589 /* let's maintain buddy itself */
1591 ord = mb_find_order_for_block(e4b, start);
1593 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1594 /* the whole chunk may be allocated at once! */
1596 buddy = mb_find_buddy(e4b, ord, &max);
1597 BUG_ON((start >> ord) >= max);
1598 mb_set_bit(start >> ord, buddy);
1599 e4b->bd_info->bb_counters[ord]--;
1606 /* store for history */
1608 ret = len | (ord << 16);
1610 /* we have to split large buddy */
1612 buddy = mb_find_buddy(e4b, ord, &max);
1613 mb_set_bit(start >> ord, buddy);
1614 e4b->bd_info->bb_counters[ord]--;
1617 cur = (start >> ord) & ~1U;
1618 buddy = mb_find_buddy(e4b, ord, &max);
1619 mb_clear_bit(cur, buddy);
1620 mb_clear_bit(cur + 1, buddy);
1621 e4b->bd_info->bb_counters[ord]++;
1622 e4b->bd_info->bb_counters[ord]++;
1624 mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
1626 ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
1627 mb_check_buddy(e4b);
1633 * Must be called under group lock!
1635 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1636 struct ext4_buddy *e4b)
1638 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1641 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1642 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1644 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1645 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1646 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1648 /* preallocation can change ac_b_ex, thus we store actually
1649 * allocated blocks for history */
1650 ac->ac_f_ex = ac->ac_b_ex;
1652 ac->ac_status = AC_STATUS_FOUND;
1653 ac->ac_tail = ret & 0xffff;
1654 ac->ac_buddy = ret >> 16;
1657 * take the page reference. We want the page to be pinned
1658 * so that we don't get a ext4_mb_init_cache_call for this
1659 * group until we update the bitmap. That would mean we
1660 * double allocate blocks. The reference is dropped
1661 * in ext4_mb_release_context
1663 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1664 get_page(ac->ac_bitmap_page);
1665 ac->ac_buddy_page = e4b->bd_buddy_page;
1666 get_page(ac->ac_buddy_page);
1667 /* store last allocated for subsequent stream allocation */
1668 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
1669 spin_lock(&sbi->s_md_lock);
1670 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1671 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1672 spin_unlock(&sbi->s_md_lock);
1677 * regular allocator, for general purposes allocation
1680 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1681 struct ext4_buddy *e4b,
1684 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1685 struct ext4_free_extent *bex = &ac->ac_b_ex;
1686 struct ext4_free_extent *gex = &ac->ac_g_ex;
1687 struct ext4_free_extent ex;
1690 if (ac->ac_status == AC_STATUS_FOUND)
1693 * We don't want to scan for a whole year
1695 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1696 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1697 ac->ac_status = AC_STATUS_BREAK;
1702 * Haven't found good chunk so far, let's continue
1704 if (bex->fe_len < gex->fe_len)
1707 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1708 && bex->fe_group == e4b->bd_group) {
1709 /* recheck chunk's availability - we don't know
1710 * when it was found (within this lock-unlock
1712 max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex);
1713 if (max >= gex->fe_len) {
1714 ext4_mb_use_best_found(ac, e4b);
1721 * The routine checks whether found extent is good enough. If it is,
1722 * then the extent gets marked used and flag is set to the context
1723 * to stop scanning. Otherwise, the extent is compared with the
1724 * previous found extent and if new one is better, then it's stored
1725 * in the context. Later, the best found extent will be used, if
1726 * mballoc can't find good enough extent.
1728 * FIXME: real allocation policy is to be designed yet!
1730 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1731 struct ext4_free_extent *ex,
1732 struct ext4_buddy *e4b)
1734 struct ext4_free_extent *bex = &ac->ac_b_ex;
1735 struct ext4_free_extent *gex = &ac->ac_g_ex;
1737 BUG_ON(ex->fe_len <= 0);
1738 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1739 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1740 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1745 * The special case - take what you catch first
1747 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1749 ext4_mb_use_best_found(ac, e4b);
1754 * Let's check whether the chuck is good enough
1756 if (ex->fe_len == gex->fe_len) {
1758 ext4_mb_use_best_found(ac, e4b);
1763 * If this is first found extent, just store it in the context
1765 if (bex->fe_len == 0) {
1771 * If new found extent is better, store it in the context
1773 if (bex->fe_len < gex->fe_len) {
1774 /* if the request isn't satisfied, any found extent
1775 * larger than previous best one is better */
1776 if (ex->fe_len > bex->fe_len)
1778 } else if (ex->fe_len > gex->fe_len) {
1779 /* if the request is satisfied, then we try to find
1780 * an extent that still satisfy the request, but is
1781 * smaller than previous one */
1782 if (ex->fe_len < bex->fe_len)
1786 ext4_mb_check_limits(ac, e4b, 0);
1789 static noinline_for_stack
1790 int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1791 struct ext4_buddy *e4b)
1793 struct ext4_free_extent ex = ac->ac_b_ex;
1794 ext4_group_t group = ex.fe_group;
1798 BUG_ON(ex.fe_len <= 0);
1799 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1803 ext4_lock_group(ac->ac_sb, group);
1804 max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex);
1808 ext4_mb_use_best_found(ac, e4b);
1811 ext4_unlock_group(ac->ac_sb, group);
1812 ext4_mb_unload_buddy(e4b);
1817 static noinline_for_stack
1818 int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1819 struct ext4_buddy *e4b)
1821 ext4_group_t group = ac->ac_g_ex.fe_group;
1824 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1825 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1826 struct ext4_free_extent ex;
1828 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1830 if (grp->bb_free == 0)
1833 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1837 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) {
1838 ext4_mb_unload_buddy(e4b);
1842 ext4_lock_group(ac->ac_sb, group);
1843 max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
1844 ac->ac_g_ex.fe_len, &ex);
1845 ex.fe_logical = 0xDEADFA11; /* debug value */
1847 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1850 start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) +
1852 /* use do_div to get remainder (would be 64-bit modulo) */
1853 if (do_div(start, sbi->s_stripe) == 0) {
1856 ext4_mb_use_best_found(ac, e4b);
1858 } else if (max >= ac->ac_g_ex.fe_len) {
1859 BUG_ON(ex.fe_len <= 0);
1860 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1861 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1864 ext4_mb_use_best_found(ac, e4b);
1865 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1866 /* Sometimes, caller may want to merge even small
1867 * number of blocks to an existing extent */
1868 BUG_ON(ex.fe_len <= 0);
1869 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1870 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1873 ext4_mb_use_best_found(ac, e4b);
1875 ext4_unlock_group(ac->ac_sb, group);
1876 ext4_mb_unload_buddy(e4b);
1882 * The routine scans buddy structures (not bitmap!) from given order
1883 * to max order and tries to find big enough chunk to satisfy the req
1885 static noinline_for_stack
1886 void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1887 struct ext4_buddy *e4b)
1889 struct super_block *sb = ac->ac_sb;
1890 struct ext4_group_info *grp = e4b->bd_info;
1896 BUG_ON(ac->ac_2order <= 0);
1897 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1898 if (grp->bb_counters[i] == 0)
1901 buddy = mb_find_buddy(e4b, i, &max);
1902 BUG_ON(buddy == NULL);
1904 k = mb_find_next_zero_bit(buddy, max, 0);
1906 ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0,
1907 "%d free clusters of order %d. But found 0",
1908 grp->bb_counters[i], i);
1909 ext4_mark_group_bitmap_corrupted(ac->ac_sb,
1911 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1916 ac->ac_b_ex.fe_len = 1 << i;
1917 ac->ac_b_ex.fe_start = k << i;
1918 ac->ac_b_ex.fe_group = e4b->bd_group;
1920 ext4_mb_use_best_found(ac, e4b);
1922 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1924 if (EXT4_SB(sb)->s_mb_stats)
1925 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1932 * The routine scans the group and measures all found extents.
1933 * In order to optimize scanning, caller must pass number of
1934 * free blocks in the group, so the routine can know upper limit.
1936 static noinline_for_stack
1937 void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1938 struct ext4_buddy *e4b)
1940 struct super_block *sb = ac->ac_sb;
1941 void *bitmap = e4b->bd_bitmap;
1942 struct ext4_free_extent ex;
1946 free = e4b->bd_info->bb_free;
1947 if (WARN_ON(free <= 0))
1950 i = e4b->bd_info->bb_first_free;
1952 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
1953 i = mb_find_next_zero_bit(bitmap,
1954 EXT4_CLUSTERS_PER_GROUP(sb), i);
1955 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
1957 * IF we have corrupt bitmap, we won't find any
1958 * free blocks even though group info says we
1959 * we have free blocks
1961 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
1962 "%d free clusters as per "
1963 "group info. But bitmap says 0",
1965 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
1966 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1970 mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex);
1971 if (WARN_ON(ex.fe_len <= 0))
1973 if (free < ex.fe_len) {
1974 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
1975 "%d free clusters as per "
1976 "group info. But got %d blocks",
1978 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
1979 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1981 * The number of free blocks differs. This mostly
1982 * indicate that the bitmap is corrupt. So exit
1983 * without claiming the space.
1987 ex.fe_logical = 0xDEADC0DE; /* debug value */
1988 ext4_mb_measure_extent(ac, &ex, e4b);
1994 ext4_mb_check_limits(ac, e4b, 1);
1998 * This is a special case for storages like raid5
1999 * we try to find stripe-aligned chunks for stripe-size-multiple requests
2001 static noinline_for_stack
2002 void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
2003 struct ext4_buddy *e4b)
2005 struct super_block *sb = ac->ac_sb;
2006 struct ext4_sb_info *sbi = EXT4_SB(sb);
2007 void *bitmap = e4b->bd_bitmap;
2008 struct ext4_free_extent ex;
2009 ext4_fsblk_t first_group_block;
2014 BUG_ON(sbi->s_stripe == 0);
2016 /* find first stripe-aligned block in group */
2017 first_group_block = ext4_group_first_block_no(sb, e4b->bd_group);
2019 a = first_group_block + sbi->s_stripe - 1;
2020 do_div(a, sbi->s_stripe);
2021 i = (a * sbi->s_stripe) - first_group_block;
2023 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2024 if (!mb_test_bit(i, bitmap)) {
2025 max = mb_find_extent(e4b, i, sbi->s_stripe, &ex);
2026 if (max >= sbi->s_stripe) {
2028 ex.fe_logical = 0xDEADF00D; /* debug value */
2030 ext4_mb_use_best_found(ac, e4b);
2039 * This is now called BEFORE we load the buddy bitmap.
2040 * Returns either 1 or 0 indicating that the group is either suitable
2041 * for the allocation or not. In addition it can also return negative
2042 * error code when something goes wrong.
2044 static int ext4_mb_good_group(struct ext4_allocation_context *ac,
2045 ext4_group_t group, int cr)
2047 unsigned free, fragments;
2048 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
2049 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2051 BUG_ON(cr < 0 || cr >= 4);
2053 free = grp->bb_free;
2056 if (cr <= 2 && free < ac->ac_g_ex.fe_len)
2059 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2062 /* We only do this if the grp has never been initialized */
2063 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2064 int ret = ext4_mb_init_group(ac->ac_sb, group, GFP_NOFS);
2069 fragments = grp->bb_fragments;
2075 BUG_ON(ac->ac_2order == 0);
2077 /* Avoid using the first bg of a flexgroup for data files */
2078 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2079 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2080 ((group % flex_size) == 0))
2083 if ((ac->ac_2order > ac->ac_sb->s_blocksize_bits+1) ||
2084 (free / fragments) >= ac->ac_g_ex.fe_len)
2087 if (grp->bb_largest_free_order < ac->ac_2order)
2092 if ((free / fragments) >= ac->ac_g_ex.fe_len)
2096 if (free >= ac->ac_g_ex.fe_len)
2108 static noinline_for_stack int
2109 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2111 ext4_group_t ngroups, group, i;
2113 int err = 0, first_err = 0;
2114 struct ext4_sb_info *sbi;
2115 struct super_block *sb;
2116 struct ext4_buddy e4b;
2120 ngroups = ext4_get_groups_count(sb);
2121 /* non-extent files are limited to low blocks/groups */
2122 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)))
2123 ngroups = sbi->s_blockfile_groups;
2125 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2127 /* first, try the goal */
2128 err = ext4_mb_find_by_goal(ac, &e4b);
2129 if (err || ac->ac_status == AC_STATUS_FOUND)
2132 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2136 * ac->ac2_order is set only if the fe_len is a power of 2
2137 * if ac2_order is set we also set criteria to 0 so that we
2138 * try exact allocation using buddy.
2140 i = fls(ac->ac_g_ex.fe_len);
2143 * We search using buddy data only if the order of the request
2144 * is greater than equal to the sbi_s_mb_order2_reqs
2145 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2146 * We also support searching for power-of-two requests only for
2147 * requests upto maximum buddy size we have constructed.
2149 if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
2151 * This should tell if fe_len is exactly power of 2
2153 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
2154 ac->ac_2order = array_index_nospec(i - 1,
2155 sb->s_blocksize_bits + 2);
2158 /* if stream allocation is enabled, use global goal */
2159 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2160 /* TBD: may be hot point */
2161 spin_lock(&sbi->s_md_lock);
2162 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2163 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2164 spin_unlock(&sbi->s_md_lock);
2167 /* Let's just scan groups to find more-less suitable blocks */
2168 cr = ac->ac_2order ? 0 : 1;
2170 * cr == 0 try to get exact allocation,
2171 * cr == 3 try to get anything
2174 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2175 ac->ac_criteria = cr;
2177 * searching for the right group start
2178 * from the goal value specified
2180 group = ac->ac_g_ex.fe_group;
2182 for (i = 0; i < ngroups; group++, i++) {
2186 * Artificially restricted ngroups for non-extent
2187 * files makes group > ngroups possible on first loop.
2189 if (group >= ngroups)
2192 /* This now checks without needing the buddy page */
2193 ret = ext4_mb_good_group(ac, group, cr);
2200 err = ext4_mb_load_buddy(sb, group, &e4b);
2204 ext4_lock_group(sb, group);
2207 * We need to check again after locking the
2210 ret = ext4_mb_good_group(ac, group, cr);
2212 ext4_unlock_group(sb, group);
2213 ext4_mb_unload_buddy(&e4b);
2219 ac->ac_groups_scanned++;
2221 ext4_mb_simple_scan_group(ac, &e4b);
2222 else if (cr == 1 && sbi->s_stripe &&
2223 !(ac->ac_g_ex.fe_len % sbi->s_stripe))
2224 ext4_mb_scan_aligned(ac, &e4b);
2226 ext4_mb_complex_scan_group(ac, &e4b);
2228 ext4_unlock_group(sb, group);
2229 ext4_mb_unload_buddy(&e4b);
2231 if (ac->ac_status != AC_STATUS_CONTINUE)
2236 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2237 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2239 * We've been searching too long. Let's try to allocate
2240 * the best chunk we've found so far
2243 ext4_mb_try_best_found(ac, &e4b);
2244 if (ac->ac_status != AC_STATUS_FOUND) {
2246 * Someone more lucky has already allocated it.
2247 * The only thing we can do is just take first
2249 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2251 ac->ac_b_ex.fe_group = 0;
2252 ac->ac_b_ex.fe_start = 0;
2253 ac->ac_b_ex.fe_len = 0;
2254 ac->ac_status = AC_STATUS_CONTINUE;
2255 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2257 atomic_inc(&sbi->s_mb_lost_chunks);
2262 if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
2267 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2269 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2272 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2275 return (void *) ((unsigned long) group);
2278 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2280 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2284 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2287 return (void *) ((unsigned long) group);
2290 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2292 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2293 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
2295 int err, buddy_loaded = 0;
2296 struct ext4_buddy e4b;
2297 struct ext4_group_info *grinfo;
2298 unsigned char blocksize_bits = min_t(unsigned char,
2299 sb->s_blocksize_bits,
2300 EXT4_MAX_BLOCK_LOG_SIZE);
2302 struct ext4_group_info info;
2303 ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
2308 seq_puts(seq, "#group: free frags first ["
2309 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
2310 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
2312 i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2313 sizeof(struct ext4_group_info);
2315 grinfo = ext4_get_group_info(sb, group);
2316 /* Load the group info in memory only if not already loaded. */
2317 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
2318 err = ext4_mb_load_buddy(sb, group, &e4b);
2320 seq_printf(seq, "#%-5u: I/O error\n", group);
2326 memcpy(&sg, ext4_get_group_info(sb, group), i);
2329 ext4_mb_unload_buddy(&e4b);
2331 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
2332 sg.info.bb_fragments, sg.info.bb_first_free);
2333 for (i = 0; i <= 13; i++)
2334 seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
2335 sg.info.bb_counters[i] : 0);
2336 seq_printf(seq, " ]\n");
2341 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2345 const struct seq_operations ext4_mb_seq_groups_ops = {
2346 .start = ext4_mb_seq_groups_start,
2347 .next = ext4_mb_seq_groups_next,
2348 .stop = ext4_mb_seq_groups_stop,
2349 .show = ext4_mb_seq_groups_show,
2352 static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
2354 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2355 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
2362 * Allocate the top-level s_group_info array for the specified number
2365 int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
2367 struct ext4_sb_info *sbi = EXT4_SB(sb);
2369 struct ext4_group_info ***old_groupinfo, ***new_groupinfo;
2371 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
2372 EXT4_DESC_PER_BLOCK_BITS(sb);
2373 if (size <= sbi->s_group_info_size)
2376 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
2377 new_groupinfo = kvzalloc(size, GFP_KERNEL);
2378 if (!new_groupinfo) {
2379 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
2383 old_groupinfo = rcu_dereference(sbi->s_group_info);
2385 memcpy(new_groupinfo, old_groupinfo,
2386 sbi->s_group_info_size * sizeof(*sbi->s_group_info));
2388 rcu_assign_pointer(sbi->s_group_info, new_groupinfo);
2389 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
2391 ext4_kvfree_array_rcu(old_groupinfo);
2392 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2393 sbi->s_group_info_size);
2397 /* Create and initialize ext4_group_info data for the given group. */
2398 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
2399 struct ext4_group_desc *desc)
2403 int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb);
2404 struct ext4_sb_info *sbi = EXT4_SB(sb);
2405 struct ext4_group_info **meta_group_info;
2406 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2409 * First check if this group is the first of a reserved block.
2410 * If it's true, we have to allocate a new table of pointers
2411 * to ext4_group_info structures
2413 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2414 metalen = sizeof(*meta_group_info) <<
2415 EXT4_DESC_PER_BLOCK_BITS(sb);
2416 meta_group_info = kmalloc(metalen, GFP_NOFS);
2417 if (meta_group_info == NULL) {
2418 ext4_msg(sb, KERN_ERR, "can't allocate mem "
2419 "for a buddy group");
2420 goto exit_meta_group_info;
2423 rcu_dereference(sbi->s_group_info)[idx] = meta_group_info;
2427 meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx);
2428 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
2430 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
2431 if (meta_group_info[i] == NULL) {
2432 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
2433 goto exit_group_info;
2435 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2436 &(meta_group_info[i]->bb_state));
2439 * initialize bb_free to be able to skip
2440 * empty groups without initialization
2442 if (ext4_has_group_desc_csum(sb) &&
2443 (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
2444 meta_group_info[i]->bb_free =
2445 ext4_free_clusters_after_init(sb, group, desc);
2447 meta_group_info[i]->bb_free =
2448 ext4_free_group_clusters(sb, desc);
2451 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
2452 init_rwsem(&meta_group_info[i]->alloc_sem);
2453 meta_group_info[i]->bb_free_root = RB_ROOT;
2454 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
2458 struct buffer_head *bh;
2459 meta_group_info[i]->bb_bitmap =
2460 kmalloc(sb->s_blocksize, GFP_NOFS);
2461 BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
2462 bh = ext4_read_block_bitmap(sb, group);
2463 BUG_ON(IS_ERR_OR_NULL(bh));
2464 memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
2473 /* If a meta_group_info table has been allocated, release it now */
2474 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2475 struct ext4_group_info ***group_info;
2478 group_info = rcu_dereference(sbi->s_group_info);
2479 kfree(group_info[idx]);
2480 group_info[idx] = NULL;
2483 exit_meta_group_info:
2485 } /* ext4_mb_add_groupinfo */
2487 static int ext4_mb_init_backend(struct super_block *sb)
2489 ext4_group_t ngroups = ext4_get_groups_count(sb);
2491 struct ext4_sb_info *sbi = EXT4_SB(sb);
2493 struct ext4_group_desc *desc;
2494 struct ext4_group_info ***group_info;
2495 struct kmem_cache *cachep;
2497 err = ext4_mb_alloc_groupinfo(sb, ngroups);
2501 sbi->s_buddy_cache = new_inode(sb);
2502 if (sbi->s_buddy_cache == NULL) {
2503 ext4_msg(sb, KERN_ERR, "can't get new inode");
2506 /* To avoid potentially colliding with an valid on-disk inode number,
2507 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2508 * not in the inode hash, so it should never be found by iget(), but
2509 * this will avoid confusion if it ever shows up during debugging. */
2510 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
2511 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2512 for (i = 0; i < ngroups; i++) {
2513 desc = ext4_get_group_desc(sb, i, NULL);
2515 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
2518 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
2525 cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2527 kmem_cache_free(cachep, ext4_get_group_info(sb, i));
2528 i = sbi->s_group_info_size;
2530 group_info = rcu_dereference(sbi->s_group_info);
2532 kfree(group_info[i]);
2534 iput(sbi->s_buddy_cache);
2537 kvfree(rcu_dereference(sbi->s_group_info));
2542 static void ext4_groupinfo_destroy_slabs(void)
2546 for (i = 0; i < NR_GRPINFO_CACHES; i++) {
2547 kmem_cache_destroy(ext4_groupinfo_caches[i]);
2548 ext4_groupinfo_caches[i] = NULL;
2552 static int ext4_groupinfo_create_slab(size_t size)
2554 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
2556 int blocksize_bits = order_base_2(size);
2557 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2558 struct kmem_cache *cachep;
2560 if (cache_index >= NR_GRPINFO_CACHES)
2563 if (unlikely(cache_index < 0))
2566 mutex_lock(&ext4_grpinfo_slab_create_mutex);
2567 if (ext4_groupinfo_caches[cache_index]) {
2568 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2569 return 0; /* Already created */
2572 slab_size = offsetof(struct ext4_group_info,
2573 bb_counters[blocksize_bits + 2]);
2575 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
2576 slab_size, 0, SLAB_RECLAIM_ACCOUNT,
2579 ext4_groupinfo_caches[cache_index] = cachep;
2581 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2584 "EXT4-fs: no memory for groupinfo slab cache\n");
2591 int ext4_mb_init(struct super_block *sb)
2593 struct ext4_sb_info *sbi = EXT4_SB(sb);
2595 unsigned offset, offset_incr;
2599 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
2601 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2602 if (sbi->s_mb_offsets == NULL) {
2607 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
2608 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2609 if (sbi->s_mb_maxs == NULL) {
2614 ret = ext4_groupinfo_create_slab(sb->s_blocksize);
2618 /* order 0 is regular bitmap */
2619 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2620 sbi->s_mb_offsets[0] = 0;
2624 offset_incr = 1 << (sb->s_blocksize_bits - 1);
2625 max = sb->s_blocksize << 2;
2627 sbi->s_mb_offsets[i] = offset;
2628 sbi->s_mb_maxs[i] = max;
2629 offset += offset_incr;
2630 offset_incr = offset_incr >> 1;
2633 } while (i <= sb->s_blocksize_bits + 1);
2635 spin_lock_init(&sbi->s_md_lock);
2636 spin_lock_init(&sbi->s_bal_lock);
2637 sbi->s_mb_free_pending = 0;
2638 INIT_LIST_HEAD(&sbi->s_freed_data_list);
2640 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2641 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2642 sbi->s_mb_stats = MB_DEFAULT_STATS;
2643 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2644 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2646 * The default group preallocation is 512, which for 4k block
2647 * sizes translates to 2 megabytes. However for bigalloc file
2648 * systems, this is probably too big (i.e, if the cluster size
2649 * is 1 megabyte, then group preallocation size becomes half a
2650 * gigabyte!). As a default, we will keep a two megabyte
2651 * group pralloc size for cluster sizes up to 64k, and after
2652 * that, we will force a minimum group preallocation size of
2653 * 32 clusters. This translates to 8 megs when the cluster
2654 * size is 256k, and 32 megs when the cluster size is 1 meg,
2655 * which seems reasonable as a default.
2657 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
2658 sbi->s_cluster_bits, 32);
2660 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2661 * to the lowest multiple of s_stripe which is bigger than
2662 * the s_mb_group_prealloc as determined above. We want
2663 * the preallocation size to be an exact multiple of the
2664 * RAID stripe size so that preallocations don't fragment
2667 if (sbi->s_stripe > 1) {
2668 sbi->s_mb_group_prealloc = roundup(
2669 sbi->s_mb_group_prealloc, sbi->s_stripe);
2672 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
2673 if (sbi->s_locality_groups == NULL) {
2677 for_each_possible_cpu(i) {
2678 struct ext4_locality_group *lg;
2679 lg = per_cpu_ptr(sbi->s_locality_groups, i);
2680 mutex_init(&lg->lg_mutex);
2681 for (j = 0; j < PREALLOC_TB_SIZE; j++)
2682 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
2683 spin_lock_init(&lg->lg_prealloc_lock);
2686 /* init file for buddy data */
2687 ret = ext4_mb_init_backend(sb);
2689 goto out_free_locality_groups;
2693 out_free_locality_groups:
2694 free_percpu(sbi->s_locality_groups);
2695 sbi->s_locality_groups = NULL;
2697 kfree(sbi->s_mb_offsets);
2698 sbi->s_mb_offsets = NULL;
2699 kfree(sbi->s_mb_maxs);
2700 sbi->s_mb_maxs = NULL;
2704 /* need to called with the ext4 group lock held */
2705 static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2707 struct ext4_prealloc_space *pa;
2708 struct list_head *cur, *tmp;
2711 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2712 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2713 list_del(&pa->pa_group_list);
2715 kmem_cache_free(ext4_pspace_cachep, pa);
2718 mb_debug(1, "mballoc: %u PAs left\n", count);
2722 int ext4_mb_release(struct super_block *sb)
2724 ext4_group_t ngroups = ext4_get_groups_count(sb);
2726 int num_meta_group_infos;
2727 struct ext4_group_info *grinfo, ***group_info;
2728 struct ext4_sb_info *sbi = EXT4_SB(sb);
2729 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2731 if (sbi->s_group_info) {
2732 for (i = 0; i < ngroups; i++) {
2733 grinfo = ext4_get_group_info(sb, i);
2735 kfree(grinfo->bb_bitmap);
2737 ext4_lock_group(sb, i);
2738 ext4_mb_cleanup_pa(grinfo);
2739 ext4_unlock_group(sb, i);
2740 kmem_cache_free(cachep, grinfo);
2742 num_meta_group_infos = (ngroups +
2743 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2744 EXT4_DESC_PER_BLOCK_BITS(sb);
2746 group_info = rcu_dereference(sbi->s_group_info);
2747 for (i = 0; i < num_meta_group_infos; i++)
2748 kfree(group_info[i]);
2752 kfree(sbi->s_mb_offsets);
2753 kfree(sbi->s_mb_maxs);
2754 iput(sbi->s_buddy_cache);
2755 if (sbi->s_mb_stats) {
2756 ext4_msg(sb, KERN_INFO,
2757 "mballoc: %u blocks %u reqs (%u success)",
2758 atomic_read(&sbi->s_bal_allocated),
2759 atomic_read(&sbi->s_bal_reqs),
2760 atomic_read(&sbi->s_bal_success));
2761 ext4_msg(sb, KERN_INFO,
2762 "mballoc: %u extents scanned, %u goal hits, "
2763 "%u 2^N hits, %u breaks, %u lost",
2764 atomic_read(&sbi->s_bal_ex_scanned),
2765 atomic_read(&sbi->s_bal_goals),
2766 atomic_read(&sbi->s_bal_2orders),
2767 atomic_read(&sbi->s_bal_breaks),
2768 atomic_read(&sbi->s_mb_lost_chunks));
2769 ext4_msg(sb, KERN_INFO,
2770 "mballoc: %lu generated and it took %Lu",
2771 sbi->s_mb_buddies_generated,
2772 sbi->s_mb_generation_time);
2773 ext4_msg(sb, KERN_INFO,
2774 "mballoc: %u preallocated, %u discarded",
2775 atomic_read(&sbi->s_mb_preallocated),
2776 atomic_read(&sbi->s_mb_discarded));
2779 free_percpu(sbi->s_locality_groups);
2784 static inline int ext4_issue_discard(struct super_block *sb,
2785 ext4_group_t block_group, ext4_grpblk_t cluster, int count,
2788 ext4_fsblk_t discard_block;
2790 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
2791 ext4_group_first_block_no(sb, block_group));
2792 count = EXT4_C2B(EXT4_SB(sb), count);
2793 trace_ext4_discard_blocks(sb,
2794 (unsigned long long) discard_block, count);
2796 return __blkdev_issue_discard(sb->s_bdev,
2797 (sector_t)discard_block << (sb->s_blocksize_bits - 9),
2798 (sector_t)count << (sb->s_blocksize_bits - 9),
2801 return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
2804 static void ext4_free_data_in_buddy(struct super_block *sb,
2805 struct ext4_free_data *entry)
2807 struct ext4_buddy e4b;
2808 struct ext4_group_info *db;
2809 int err, count = 0, count2 = 0;
2811 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2812 entry->efd_count, entry->efd_group, entry);
2814 err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
2815 /* we expect to find existing buddy because it's pinned */
2818 spin_lock(&EXT4_SB(sb)->s_md_lock);
2819 EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
2820 spin_unlock(&EXT4_SB(sb)->s_md_lock);
2823 /* there are blocks to put in buddy to make them really free */
2824 count += entry->efd_count;
2826 ext4_lock_group(sb, entry->efd_group);
2827 /* Take it out of per group rb tree */
2828 rb_erase(&entry->efd_node, &(db->bb_free_root));
2829 mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count);
2832 * Clear the trimmed flag for the group so that the next
2833 * ext4_trim_fs can trim it.
2834 * If the volume is mounted with -o discard, online discard
2835 * is supported and the free blocks will be trimmed online.
2837 if (!test_opt(sb, DISCARD))
2838 EXT4_MB_GRP_CLEAR_TRIMMED(db);
2840 if (!db->bb_free_root.rb_node) {
2841 /* No more items in the per group rb tree
2842 * balance refcounts from ext4_mb_free_metadata()
2844 put_page(e4b.bd_buddy_page);
2845 put_page(e4b.bd_bitmap_page);
2847 ext4_unlock_group(sb, entry->efd_group);
2848 kmem_cache_free(ext4_free_data_cachep, entry);
2849 ext4_mb_unload_buddy(&e4b);
2851 mb_debug(1, "freed %u blocks in %u structures\n", count, count2);
2855 * This function is called by the jbd2 layer once the commit has finished,
2856 * so we know we can free the blocks that were released with that commit.
2858 void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
2860 struct ext4_sb_info *sbi = EXT4_SB(sb);
2861 struct ext4_free_data *entry, *tmp;
2862 struct bio *discard_bio = NULL;
2863 struct list_head freed_data_list;
2864 struct list_head *cut_pos = NULL;
2867 INIT_LIST_HEAD(&freed_data_list);
2869 spin_lock(&sbi->s_md_lock);
2870 list_for_each_entry(entry, &sbi->s_freed_data_list, efd_list) {
2871 if (entry->efd_tid != commit_tid)
2873 cut_pos = &entry->efd_list;
2876 list_cut_position(&freed_data_list, &sbi->s_freed_data_list,
2878 spin_unlock(&sbi->s_md_lock);
2880 if (test_opt(sb, DISCARD)) {
2881 list_for_each_entry(entry, &freed_data_list, efd_list) {
2882 err = ext4_issue_discard(sb, entry->efd_group,
2883 entry->efd_start_cluster,
2886 if (err && err != -EOPNOTSUPP) {
2887 ext4_msg(sb, KERN_WARNING, "discard request in"
2888 " group:%d block:%d count:%d failed"
2889 " with %d", entry->efd_group,
2890 entry->efd_start_cluster,
2891 entry->efd_count, err);
2892 } else if (err == -EOPNOTSUPP)
2897 submit_bio_wait(discard_bio);
2898 bio_put(discard_bio);
2902 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
2903 ext4_free_data_in_buddy(sb, entry);
2906 int __init ext4_init_mballoc(void)
2908 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
2909 SLAB_RECLAIM_ACCOUNT);
2910 if (ext4_pspace_cachep == NULL)
2913 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
2914 SLAB_RECLAIM_ACCOUNT);
2915 if (ext4_ac_cachep == NULL) {
2916 kmem_cache_destroy(ext4_pspace_cachep);
2920 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
2921 SLAB_RECLAIM_ACCOUNT);
2922 if (ext4_free_data_cachep == NULL) {
2923 kmem_cache_destroy(ext4_pspace_cachep);
2924 kmem_cache_destroy(ext4_ac_cachep);
2930 void ext4_exit_mballoc(void)
2933 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2934 * before destroying the slab cache.
2937 kmem_cache_destroy(ext4_pspace_cachep);
2938 kmem_cache_destroy(ext4_ac_cachep);
2939 kmem_cache_destroy(ext4_free_data_cachep);
2940 ext4_groupinfo_destroy_slabs();
2945 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2946 * Returns 0 if success or error code
2948 static noinline_for_stack int
2949 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
2950 handle_t *handle, unsigned int reserv_clstrs)
2952 struct buffer_head *bitmap_bh = NULL;
2953 struct ext4_group_desc *gdp;
2954 struct buffer_head *gdp_bh;
2955 struct ext4_sb_info *sbi;
2956 struct super_block *sb;
2960 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
2961 BUG_ON(ac->ac_b_ex.fe_len <= 0);
2966 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
2967 if (IS_ERR(bitmap_bh)) {
2968 err = PTR_ERR(bitmap_bh);
2973 BUFFER_TRACE(bitmap_bh, "getting write access");
2974 err = ext4_journal_get_write_access(handle, bitmap_bh);
2979 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
2983 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
2984 ext4_free_group_clusters(sb, gdp));
2986 BUFFER_TRACE(gdp_bh, "get_write_access");
2987 err = ext4_journal_get_write_access(handle, gdp_bh);
2991 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
2993 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
2994 if (!ext4_inode_block_valid(ac->ac_inode, block, len)) {
2995 ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
2996 "fs metadata", block, block+len);
2997 /* File system mounted not to panic on error
2998 * Fix the bitmap and return EFSCORRUPTED
2999 * We leak some of the blocks here.
3001 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3002 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3003 ac->ac_b_ex.fe_len);
3004 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3005 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3007 err = -EFSCORRUPTED;
3011 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3012 #ifdef AGGRESSIVE_CHECK
3015 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3016 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3017 bitmap_bh->b_data));
3021 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3022 ac->ac_b_ex.fe_len);
3023 if (ext4_has_group_desc_csum(sb) &&
3024 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3025 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3026 ext4_free_group_clusters_set(sb, gdp,
3027 ext4_free_clusters_after_init(sb,
3028 ac->ac_b_ex.fe_group, gdp));
3030 len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
3031 ext4_free_group_clusters_set(sb, gdp, len);
3032 ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
3033 ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
3035 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3036 percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
3038 * Now reduce the dirty block count also. Should not go negative
3040 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
3041 /* release all the reserved blocks if non delalloc */
3042 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
3045 if (sbi->s_log_groups_per_flex) {
3046 ext4_group_t flex_group = ext4_flex_group(sbi,
3047 ac->ac_b_ex.fe_group);
3048 atomic64_sub(ac->ac_b_ex.fe_len,
3049 &sbi_array_rcu_deref(sbi, s_flex_groups,
3050 flex_group)->free_clusters);
3053 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3056 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
3064 * here we normalize request for locality group
3065 * Group request are normalized to s_mb_group_prealloc, which goes to
3066 * s_strip if we set the same via mount option.
3067 * s_mb_group_prealloc can be configured via
3068 * /sys/fs/ext4/<partition>/mb_group_prealloc
3070 * XXX: should we try to preallocate more than the group has now?
3072 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3074 struct super_block *sb = ac->ac_sb;
3075 struct ext4_locality_group *lg = ac->ac_lg;
3078 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3079 mb_debug(1, "#%u: goal %u blocks for locality group\n",
3080 current->pid, ac->ac_g_ex.fe_len);
3084 * Normalization means making request better in terms of
3085 * size and alignment
3087 static noinline_for_stack void
3088 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
3089 struct ext4_allocation_request *ar)
3091 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3092 struct ext4_super_block *es = sbi->s_es;
3095 loff_t size, start_off;
3096 loff_t orig_size __maybe_unused;
3098 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3099 struct ext4_prealloc_space *pa;
3101 /* do normalize only data requests, metadata requests
3102 do not need preallocation */
3103 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3106 /* sometime caller may want exact blocks */
3107 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3110 /* caller may indicate that preallocation isn't
3111 * required (it's a tail, for example) */
3112 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3115 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3116 ext4_mb_normalize_group_request(ac);
3120 bsbits = ac->ac_sb->s_blocksize_bits;
3122 /* first, let's learn actual file size
3123 * given current request is allocated */
3124 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
3125 size = size << bsbits;
3126 if (size < i_size_read(ac->ac_inode))
3127 size = i_size_read(ac->ac_inode);
3130 /* max size of free chunks */
3133 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3134 (req <= (size) || max <= (chunk_size))
3136 /* first, try to predict filesize */
3137 /* XXX: should this table be tunable? */
3139 if (size <= 16 * 1024) {
3141 } else if (size <= 32 * 1024) {
3143 } else if (size <= 64 * 1024) {
3145 } else if (size <= 128 * 1024) {
3147 } else if (size <= 256 * 1024) {
3149 } else if (size <= 512 * 1024) {
3151 } else if (size <= 1024 * 1024) {
3153 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
3154 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3155 (21 - bsbits)) << 21;
3156 size = 2 * 1024 * 1024;
3157 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
3158 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3159 (22 - bsbits)) << 22;
3160 size = 4 * 1024 * 1024;
3161 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3162 (8<<20)>>bsbits, max, 8 * 1024)) {
3163 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3164 (23 - bsbits)) << 23;
3165 size = 8 * 1024 * 1024;
3167 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
3168 size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
3169 ac->ac_o_ex.fe_len) << bsbits;
3171 size = size >> bsbits;
3172 start = start_off >> bsbits;
3175 * For tiny groups (smaller than 8MB) the chosen allocation
3176 * alignment may be larger than group size. Make sure the
3177 * alignment does not move allocation to a different group which
3178 * makes mballoc fail assertions later.
3180 start = max(start, rounddown(ac->ac_o_ex.fe_logical,
3181 (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
3183 /* don't cover already allocated blocks in selected range */
3184 if (ar->pleft && start <= ar->lleft) {
3185 size -= ar->lleft + 1 - start;
3186 start = ar->lleft + 1;
3188 if (ar->pright && start + size - 1 >= ar->lright)
3189 size -= start + size - ar->lright;
3192 * Trim allocation request for filesystems with artificially small
3195 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
3196 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
3200 /* check we don't cross already preallocated blocks */
3202 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3207 spin_lock(&pa->pa_lock);
3208 if (pa->pa_deleted) {
3209 spin_unlock(&pa->pa_lock);
3213 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3216 /* PA must not overlap original request */
3217 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3218 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3220 /* skip PAs this normalized request doesn't overlap with */
3221 if (pa->pa_lstart >= end || pa_end <= start) {
3222 spin_unlock(&pa->pa_lock);
3225 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3227 /* adjust start or end to be adjacent to this pa */
3228 if (pa_end <= ac->ac_o_ex.fe_logical) {
3229 BUG_ON(pa_end < start);
3231 } else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3232 BUG_ON(pa->pa_lstart > end);
3233 end = pa->pa_lstart;
3235 spin_unlock(&pa->pa_lock);
3240 /* XXX: extra loop to check we really don't overlap preallocations */
3242 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3245 spin_lock(&pa->pa_lock);
3246 if (pa->pa_deleted == 0) {
3247 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3249 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3251 spin_unlock(&pa->pa_lock);
3255 if (start + size <= ac->ac_o_ex.fe_logical &&
3256 start > ac->ac_o_ex.fe_logical) {
3257 ext4_msg(ac->ac_sb, KERN_ERR,
3258 "start %lu, size %lu, fe_logical %lu",
3259 (unsigned long) start, (unsigned long) size,
3260 (unsigned long) ac->ac_o_ex.fe_logical);
3263 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3265 /* now prepare goal request */
3267 /* XXX: is it better to align blocks WRT to logical
3268 * placement or satisfy big request as is */
3269 ac->ac_g_ex.fe_logical = start;
3270 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
3272 /* define goal start in order to merge */
3273 if (ar->pright && (ar->lright == (start + size)) &&
3274 ar->pright >= size &&
3275 ar->pright - size >= le32_to_cpu(es->s_first_data_block)) {
3276 /* merge to the right */
3277 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3278 &ac->ac_g_ex.fe_group,
3279 &ac->ac_g_ex.fe_start);
3280 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3282 if (ar->pleft && (ar->lleft + 1 == start) &&
3283 ar->pleft + 1 < ext4_blocks_count(es)) {
3284 /* merge to the left */
3285 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3286 &ac->ac_g_ex.fe_group,
3287 &ac->ac_g_ex.fe_start);
3288 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3291 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size,
3292 (unsigned) orig_size, (unsigned) start);
3295 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3297 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3299 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3300 atomic_inc(&sbi->s_bal_reqs);
3301 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3302 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
3303 atomic_inc(&sbi->s_bal_success);
3304 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3305 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3306 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3307 atomic_inc(&sbi->s_bal_goals);
3308 if (ac->ac_found > sbi->s_mb_max_to_scan)
3309 atomic_inc(&sbi->s_bal_breaks);
3312 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
3313 trace_ext4_mballoc_alloc(ac);
3315 trace_ext4_mballoc_prealloc(ac);
3319 * Called on failure; free up any blocks from the inode PA for this
3320 * context. We don't need this for MB_GROUP_PA because we only change
3321 * pa_free in ext4_mb_release_context(), but on failure, we've already
3322 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3324 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
3326 struct ext4_prealloc_space *pa = ac->ac_pa;
3327 struct ext4_buddy e4b;
3331 if (ac->ac_f_ex.fe_len == 0)
3333 err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
3336 * This should never happen since we pin the
3337 * pages in the ext4_allocation_context so
3338 * ext4_mb_load_buddy() should never fail.
3340 WARN(1, "mb_load_buddy failed (%d)", err);
3343 ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3344 mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
3345 ac->ac_f_ex.fe_len);
3346 ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3347 ext4_mb_unload_buddy(&e4b);
3350 if (pa->pa_type == MB_INODE_PA)
3351 pa->pa_free += ac->ac_b_ex.fe_len;
3355 * use blocks preallocated to inode
3357 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3358 struct ext4_prealloc_space *pa)
3360 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3365 /* found preallocated blocks, use them */
3366 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3367 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
3368 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
3369 len = EXT4_NUM_B2C(sbi, end - start);
3370 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3371 &ac->ac_b_ex.fe_start);
3372 ac->ac_b_ex.fe_len = len;
3373 ac->ac_status = AC_STATUS_FOUND;
3376 BUG_ON(start < pa->pa_pstart);
3377 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
3378 BUG_ON(pa->pa_free < len);
3379 BUG_ON(ac->ac_b_ex.fe_len <= 0);
3382 mb_debug(1, "use %llu/%u from inode pa %p\n", start, len, pa);
3386 * use blocks preallocated to locality group
3388 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3389 struct ext4_prealloc_space *pa)
3391 unsigned int len = ac->ac_o_ex.fe_len;
3393 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3394 &ac->ac_b_ex.fe_group,
3395 &ac->ac_b_ex.fe_start);
3396 ac->ac_b_ex.fe_len = len;
3397 ac->ac_status = AC_STATUS_FOUND;
3400 /* we don't correct pa_pstart or pa_plen here to avoid
3401 * possible race when the group is being loaded concurrently
3402 * instead we correct pa later, after blocks are marked
3403 * in on-disk bitmap -- see ext4_mb_release_context()
3404 * Other CPUs are prevented from allocating from this pa by lg_mutex
3406 mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3410 * Return the prealloc space that have minimal distance
3411 * from the goal block. @cpa is the prealloc
3412 * space that is having currently known minimal distance
3413 * from the goal block.
3415 static struct ext4_prealloc_space *
3416 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
3417 struct ext4_prealloc_space *pa,
3418 struct ext4_prealloc_space *cpa)
3420 ext4_fsblk_t cur_distance, new_distance;
3423 atomic_inc(&pa->pa_count);
3426 cur_distance = abs(goal_block - cpa->pa_pstart);
3427 new_distance = abs(goal_block - pa->pa_pstart);
3429 if (cur_distance <= new_distance)
3432 /* drop the previous reference */
3433 atomic_dec(&cpa->pa_count);
3434 atomic_inc(&pa->pa_count);
3439 * search goal blocks in preallocated space
3441 static noinline_for_stack int
3442 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
3444 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3446 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3447 struct ext4_locality_group *lg;
3448 struct ext4_prealloc_space *pa, *cpa = NULL;
3449 ext4_fsblk_t goal_block;
3451 /* only data can be preallocated */
3452 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3455 /* first, try per-file preallocation */
3457 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3459 /* all fields in this condition don't change,
3460 * so we can skip locking for them */
3461 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3462 ac->ac_o_ex.fe_logical >= (pa->pa_lstart +
3463 EXT4_C2B(sbi, pa->pa_len)))
3466 /* non-extent files can't have physical blocks past 2^32 */
3467 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) &&
3468 (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) >
3469 EXT4_MAX_BLOCK_FILE_PHYS))
3472 /* found preallocated blocks, use them */
3473 spin_lock(&pa->pa_lock);
3474 if (pa->pa_deleted == 0 && pa->pa_free) {
3475 atomic_inc(&pa->pa_count);
3476 ext4_mb_use_inode_pa(ac, pa);
3477 spin_unlock(&pa->pa_lock);
3478 ac->ac_criteria = 10;
3482 spin_unlock(&pa->pa_lock);
3486 /* can we use group allocation? */
3487 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3490 /* inode may have no locality group for some reason */
3494 order = fls(ac->ac_o_ex.fe_len) - 1;
3495 if (order > PREALLOC_TB_SIZE - 1)
3496 /* The max size of hash table is PREALLOC_TB_SIZE */
3497 order = PREALLOC_TB_SIZE - 1;
3499 goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex);
3501 * search for the prealloc space that is having
3502 * minimal distance from the goal block.
3504 for (i = order; i < PREALLOC_TB_SIZE; i++) {
3506 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
3508 spin_lock(&pa->pa_lock);
3509 if (pa->pa_deleted == 0 &&
3510 pa->pa_free >= ac->ac_o_ex.fe_len) {
3512 cpa = ext4_mb_check_group_pa(goal_block,
3515 spin_unlock(&pa->pa_lock);
3520 ext4_mb_use_group_pa(ac, cpa);
3521 ac->ac_criteria = 20;
3528 * the function goes through all block freed in the group
3529 * but not yet committed and marks them used in in-core bitmap.
3530 * buddy must be generated from this bitmap
3531 * Need to be called with the ext4 group lock held
3533 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
3537 struct ext4_group_info *grp;
3538 struct ext4_free_data *entry;
3540 grp = ext4_get_group_info(sb, group);
3541 n = rb_first(&(grp->bb_free_root));
3544 entry = rb_entry(n, struct ext4_free_data, efd_node);
3545 ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count);
3552 * the function goes through all preallocation in this group and marks them
3553 * used in in-core bitmap. buddy must be generated from this bitmap
3554 * Need to be called with ext4 group lock held
3556 static noinline_for_stack
3557 void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3560 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3561 struct ext4_prealloc_space *pa;
3562 struct list_head *cur;
3563 ext4_group_t groupnr;
3564 ext4_grpblk_t start;
3565 int preallocated = 0;
3568 /* all form of preallocation discards first load group,
3569 * so the only competing code is preallocation use.
3570 * we don't need any locking here
3571 * notice we do NOT ignore preallocations with pa_deleted
3572 * otherwise we could leave used blocks available for
3573 * allocation in buddy when concurrent ext4_mb_put_pa()
3574 * is dropping preallocation
3576 list_for_each(cur, &grp->bb_prealloc_list) {
3577 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3578 spin_lock(&pa->pa_lock);
3579 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3582 spin_unlock(&pa->pa_lock);
3583 if (unlikely(len == 0))
3585 BUG_ON(groupnr != group);
3586 ext4_set_bits(bitmap, start, len);
3587 preallocated += len;
3589 mb_debug(1, "preallocated %u for group %u\n", preallocated, group);
3592 static void ext4_mb_pa_callback(struct rcu_head *head)
3594 struct ext4_prealloc_space *pa;
3595 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3597 BUG_ON(atomic_read(&pa->pa_count));
3598 BUG_ON(pa->pa_deleted == 0);
3599 kmem_cache_free(ext4_pspace_cachep, pa);
3603 * drops a reference to preallocated space descriptor
3604 * if this was the last reference and the space is consumed
3606 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3607 struct super_block *sb, struct ext4_prealloc_space *pa)
3610 ext4_fsblk_t grp_blk;
3612 /* in this short window concurrent discard can set pa_deleted */
3613 spin_lock(&pa->pa_lock);
3614 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {
3615 spin_unlock(&pa->pa_lock);
3619 if (pa->pa_deleted == 1) {
3620 spin_unlock(&pa->pa_lock);
3625 spin_unlock(&pa->pa_lock);
3627 grp_blk = pa->pa_pstart;
3629 * If doing group-based preallocation, pa_pstart may be in the
3630 * next group when pa is used up
3632 if (pa->pa_type == MB_GROUP_PA)
3635 grp = ext4_get_group_number(sb, grp_blk);
3640 * P1 (buddy init) P2 (regular allocation)
3641 * find block B in PA
3642 * copy on-disk bitmap to buddy
3643 * mark B in on-disk bitmap
3644 * drop PA from group
3645 * mark all PAs in buddy
3647 * thus, P1 initializes buddy with B available. to prevent this
3648 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3651 ext4_lock_group(sb, grp);
3652 list_del(&pa->pa_group_list);
3653 ext4_unlock_group(sb, grp);
3655 spin_lock(pa->pa_obj_lock);
3656 list_del_rcu(&pa->pa_inode_list);
3657 spin_unlock(pa->pa_obj_lock);
3659 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3663 * creates new preallocated space for given inode
3665 static noinline_for_stack int
3666 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
3668 struct super_block *sb = ac->ac_sb;
3669 struct ext4_sb_info *sbi = EXT4_SB(sb);
3670 struct ext4_prealloc_space *pa;
3671 struct ext4_group_info *grp;
3672 struct ext4_inode_info *ei;
3674 /* preallocate only when found space is larger then requested */
3675 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3676 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3677 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3679 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3683 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3687 /* we can't allocate as much as normalizer wants.
3688 * so, found space must get proper lstart
3689 * to cover original request */
3690 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3691 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3694 * Use the below logic for adjusting best extent as it keeps
3695 * fragmentation in check while ensuring logical range of best
3696 * extent doesn't overflow out of goal extent:
3698 * 1. Check if best ex can be kept at end of goal and still
3699 * cover original start
3700 * 2. Else, check if best ex can be kept at start of goal and
3701 * still cover original start
3702 * 3. Else, keep the best ex at start of original request.
3704 new_bex_end = ac->ac_g_ex.fe_logical +
3705 EXT4_C2B(sbi, ac->ac_g_ex.fe_len);
3706 new_bex_start = new_bex_end - EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
3707 if (ac->ac_o_ex.fe_logical >= new_bex_start)
3710 new_bex_start = ac->ac_g_ex.fe_logical;
3712 new_bex_start + EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
3713 if (ac->ac_o_ex.fe_logical < new_bex_end)
3716 new_bex_start = ac->ac_o_ex.fe_logical;
3718 new_bex_start + EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
3721 ac->ac_b_ex.fe_logical = new_bex_start;
3723 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3724 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3725 BUG_ON(new_bex_end > (ac->ac_g_ex.fe_logical +
3726 EXT4_C2B(sbi, ac->ac_g_ex.fe_len)));
3729 /* preallocation can change ac_b_ex, thus we store actually
3730 * allocated blocks for history */
3731 ac->ac_f_ex = ac->ac_b_ex;
3733 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3734 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3735 pa->pa_len = ac->ac_b_ex.fe_len;
3736 pa->pa_free = pa->pa_len;
3737 atomic_set(&pa->pa_count, 1);
3738 spin_lock_init(&pa->pa_lock);
3739 INIT_LIST_HEAD(&pa->pa_inode_list);
3740 INIT_LIST_HEAD(&pa->pa_group_list);
3742 pa->pa_type = MB_INODE_PA;
3744 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa,
3745 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3746 trace_ext4_mb_new_inode_pa(ac, pa);
3748 ext4_mb_use_inode_pa(ac, pa);
3749 atomic_add(pa->pa_free, &sbi->s_mb_preallocated);
3751 ei = EXT4_I(ac->ac_inode);
3752 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3754 pa->pa_obj_lock = &ei->i_prealloc_lock;
3755 pa->pa_inode = ac->ac_inode;
3757 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3758 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3759 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3761 spin_lock(pa->pa_obj_lock);
3762 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3763 spin_unlock(pa->pa_obj_lock);
3769 * creates new preallocated space for locality group inodes belongs to
3771 static noinline_for_stack int
3772 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
3774 struct super_block *sb = ac->ac_sb;
3775 struct ext4_locality_group *lg;
3776 struct ext4_prealloc_space *pa;
3777 struct ext4_group_info *grp;
3779 /* preallocate only when found space is larger then requested */
3780 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3781 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3782 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3784 BUG_ON(ext4_pspace_cachep == NULL);
3785 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3789 /* preallocation can change ac_b_ex, thus we store actually
3790 * allocated blocks for history */
3791 ac->ac_f_ex = ac->ac_b_ex;
3793 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3794 pa->pa_lstart = pa->pa_pstart;
3795 pa->pa_len = ac->ac_b_ex.fe_len;
3796 pa->pa_free = pa->pa_len;
3797 atomic_set(&pa->pa_count, 1);
3798 spin_lock_init(&pa->pa_lock);
3799 INIT_LIST_HEAD(&pa->pa_inode_list);
3800 INIT_LIST_HEAD(&pa->pa_group_list);
3802 pa->pa_type = MB_GROUP_PA;
3804 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa,
3805 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3806 trace_ext4_mb_new_group_pa(ac, pa);
3808 ext4_mb_use_group_pa(ac, pa);
3809 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3811 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3815 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3816 pa->pa_inode = NULL;
3818 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3819 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3820 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3823 * We will later add the new pa to the right bucket
3824 * after updating the pa_free in ext4_mb_release_context
3829 static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3833 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3834 err = ext4_mb_new_group_pa(ac);
3836 err = ext4_mb_new_inode_pa(ac);
3841 * finds all unused blocks in on-disk bitmap, frees them in
3842 * in-core bitmap and buddy.
3843 * @pa must be unlinked from inode and group lists, so that
3844 * nobody else can find/use it.
3845 * the caller MUST hold group/inode locks.
3846 * TODO: optimize the case when there are no in-core structures yet
3848 static noinline_for_stack int
3849 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
3850 struct ext4_prealloc_space *pa)
3852 struct super_block *sb = e4b->bd_sb;
3853 struct ext4_sb_info *sbi = EXT4_SB(sb);
3858 unsigned long long grp_blk_start;
3861 BUG_ON(pa->pa_deleted == 0);
3862 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3863 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
3864 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3865 end = bit + pa->pa_len;
3868 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
3871 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
3872 mb_debug(1, " free preallocated %u/%u in group %u\n",
3873 (unsigned) ext4_group_first_block_no(sb, group) + bit,
3874 (unsigned) next - bit, (unsigned) group);
3877 trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);
3878 trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +
3879 EXT4_C2B(sbi, bit)),
3881 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3884 if (free != pa->pa_free) {
3885 ext4_msg(e4b->bd_sb, KERN_CRIT,
3886 "pa %p: logic %lu, phys. %lu, len %lu",
3887 pa, (unsigned long) pa->pa_lstart,
3888 (unsigned long) pa->pa_pstart,
3889 (unsigned long) pa->pa_len);
3890 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
3893 * pa is already deleted so we use the value obtained
3894 * from the bitmap and continue.
3897 atomic_add(free, &sbi->s_mb_discarded);
3902 static noinline_for_stack int
3903 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
3904 struct ext4_prealloc_space *pa)
3906 struct super_block *sb = e4b->bd_sb;
3910 trace_ext4_mb_release_group_pa(sb, pa);
3911 BUG_ON(pa->pa_deleted == 0);
3912 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3913 if (unlikely(group != e4b->bd_group && pa->pa_len != 0)) {
3914 ext4_warning(sb, "bad group: expected %u, group %u, pa_start %llu",
3915 e4b->bd_group, group, pa->pa_pstart);
3918 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3919 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3920 trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);
3926 * releases all preallocations in given group
3928 * first, we need to decide discard policy:
3929 * - when do we discard
3931 * - how many do we discard
3932 * 1) how many requested
3934 static noinline_for_stack int
3935 ext4_mb_discard_group_preallocations(struct super_block *sb,
3936 ext4_group_t group, int needed)
3938 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3939 struct buffer_head *bitmap_bh = NULL;
3940 struct ext4_prealloc_space *pa, *tmp;
3941 struct list_head list;
3942 struct ext4_buddy e4b;
3947 mb_debug(1, "discard preallocation for group %u\n", group);
3949 if (list_empty(&grp->bb_prealloc_list))
3952 bitmap_bh = ext4_read_block_bitmap(sb, group);
3953 if (IS_ERR(bitmap_bh)) {
3954 err = PTR_ERR(bitmap_bh);
3955 ext4_error(sb, "Error %d reading block bitmap for %u",
3960 err = ext4_mb_load_buddy(sb, group, &e4b);
3962 ext4_warning(sb, "Error %d loading buddy information for %u",
3969 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
3971 INIT_LIST_HEAD(&list);
3973 ext4_lock_group(sb, group);
3974 list_for_each_entry_safe(pa, tmp,
3975 &grp->bb_prealloc_list, pa_group_list) {
3976 spin_lock(&pa->pa_lock);
3977 if (atomic_read(&pa->pa_count)) {
3978 spin_unlock(&pa->pa_lock);
3982 if (pa->pa_deleted) {
3983 spin_unlock(&pa->pa_lock);
3987 /* seems this one can be freed ... */
3990 /* we can trust pa_free ... */
3991 free += pa->pa_free;
3993 spin_unlock(&pa->pa_lock);
3995 list_del(&pa->pa_group_list);
3996 list_add(&pa->u.pa_tmp_list, &list);
3999 /* if we still need more blocks and some PAs were used, try again */
4000 if (free < needed && busy) {
4002 ext4_unlock_group(sb, group);
4007 /* found anything to free? */
4008 if (list_empty(&list)) {
4013 /* now free all selected PAs */
4014 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4016 /* remove from object (inode or locality group) */
4017 spin_lock(pa->pa_obj_lock);
4018 list_del_rcu(&pa->pa_inode_list);
4019 spin_unlock(pa->pa_obj_lock);
4021 if (pa->pa_type == MB_GROUP_PA)
4022 ext4_mb_release_group_pa(&e4b, pa);
4024 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4026 list_del(&pa->u.pa_tmp_list);
4027 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4031 ext4_unlock_group(sb, group);
4032 ext4_mb_unload_buddy(&e4b);
4038 * releases all non-used preallocated blocks for given inode
4040 * It's important to discard preallocations under i_data_sem
4041 * We don't want another block to be served from the prealloc
4042 * space when we are discarding the inode prealloc space.
4044 * FIXME!! Make sure it is valid at all the call sites
4046 void ext4_discard_preallocations(struct inode *inode)
4048 struct ext4_inode_info *ei = EXT4_I(inode);
4049 struct super_block *sb = inode->i_sb;
4050 struct buffer_head *bitmap_bh = NULL;
4051 struct ext4_prealloc_space *pa, *tmp;
4052 ext4_group_t group = 0;
4053 struct list_head list;
4054 struct ext4_buddy e4b;
4057 if (!S_ISREG(inode->i_mode)) {
4058 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
4062 mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino);
4063 trace_ext4_discard_preallocations(inode);
4065 INIT_LIST_HEAD(&list);
4068 /* first, collect all pa's in the inode */
4069 spin_lock(&ei->i_prealloc_lock);
4070 while (!list_empty(&ei->i_prealloc_list)) {
4071 pa = list_entry(ei->i_prealloc_list.next,
4072 struct ext4_prealloc_space, pa_inode_list);
4073 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
4074 spin_lock(&pa->pa_lock);
4075 if (atomic_read(&pa->pa_count)) {
4076 /* this shouldn't happen often - nobody should
4077 * use preallocation while we're discarding it */
4078 spin_unlock(&pa->pa_lock);
4079 spin_unlock(&ei->i_prealloc_lock);
4080 ext4_msg(sb, KERN_ERR,
4081 "uh-oh! used pa while discarding");
4083 schedule_timeout_uninterruptible(HZ);
4087 if (pa->pa_deleted == 0) {
4089 spin_unlock(&pa->pa_lock);
4090 list_del_rcu(&pa->pa_inode_list);
4091 list_add(&pa->u.pa_tmp_list, &list);
4095 /* someone is deleting pa right now */
4096 spin_unlock(&pa->pa_lock);
4097 spin_unlock(&ei->i_prealloc_lock);
4099 /* we have to wait here because pa_deleted
4100 * doesn't mean pa is already unlinked from
4101 * the list. as we might be called from
4102 * ->clear_inode() the inode will get freed
4103 * and concurrent thread which is unlinking
4104 * pa from inode's list may access already
4105 * freed memory, bad-bad-bad */
4107 /* XXX: if this happens too often, we can
4108 * add a flag to force wait only in case
4109 * of ->clear_inode(), but not in case of
4110 * regular truncate */
4111 schedule_timeout_uninterruptible(HZ);
4114 spin_unlock(&ei->i_prealloc_lock);
4116 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4117 BUG_ON(pa->pa_type != MB_INODE_PA);
4118 group = ext4_get_group_number(sb, pa->pa_pstart);
4120 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4121 GFP_NOFS|__GFP_NOFAIL);
4123 ext4_error(sb, "Error %d loading buddy information for %u",
4128 bitmap_bh = ext4_read_block_bitmap(sb, group);
4129 if (IS_ERR(bitmap_bh)) {
4130 err = PTR_ERR(bitmap_bh);
4131 ext4_error(sb, "Error %d reading block bitmap for %u",
4133 ext4_mb_unload_buddy(&e4b);
4137 ext4_lock_group(sb, group);
4138 list_del(&pa->pa_group_list);
4139 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4140 ext4_unlock_group(sb, group);
4142 ext4_mb_unload_buddy(&e4b);
4145 list_del(&pa->u.pa_tmp_list);
4146 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4150 #ifdef CONFIG_EXT4_DEBUG
4151 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4153 struct super_block *sb = ac->ac_sb;
4154 ext4_group_t ngroups, i;
4156 if (!ext4_mballoc_debug ||
4157 (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED))
4160 ext4_msg(ac->ac_sb, KERN_ERR, "Can't allocate:"
4161 " Allocation context details:");
4162 ext4_msg(ac->ac_sb, KERN_ERR, "status %d flags %d",
4163 ac->ac_status, ac->ac_flags);
4164 ext4_msg(ac->ac_sb, KERN_ERR, "orig %lu/%lu/%lu@%lu, "
4165 "goal %lu/%lu/%lu@%lu, "
4166 "best %lu/%lu/%lu@%lu cr %d",
4167 (unsigned long)ac->ac_o_ex.fe_group,
4168 (unsigned long)ac->ac_o_ex.fe_start,
4169 (unsigned long)ac->ac_o_ex.fe_len,
4170 (unsigned long)ac->ac_o_ex.fe_logical,
4171 (unsigned long)ac->ac_g_ex.fe_group,
4172 (unsigned long)ac->ac_g_ex.fe_start,
4173 (unsigned long)ac->ac_g_ex.fe_len,
4174 (unsigned long)ac->ac_g_ex.fe_logical,
4175 (unsigned long)ac->ac_b_ex.fe_group,
4176 (unsigned long)ac->ac_b_ex.fe_start,
4177 (unsigned long)ac->ac_b_ex.fe_len,
4178 (unsigned long)ac->ac_b_ex.fe_logical,
4179 (int)ac->ac_criteria);
4180 ext4_msg(ac->ac_sb, KERN_ERR, "%d found", ac->ac_found);
4181 ext4_msg(ac->ac_sb, KERN_ERR, "groups: ");
4182 ngroups = ext4_get_groups_count(sb);
4183 for (i = 0; i < ngroups; i++) {
4184 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4185 struct ext4_prealloc_space *pa;
4186 ext4_grpblk_t start;
4187 struct list_head *cur;
4188 ext4_lock_group(sb, i);
4189 list_for_each(cur, &grp->bb_prealloc_list) {
4190 pa = list_entry(cur, struct ext4_prealloc_space,
4192 spin_lock(&pa->pa_lock);
4193 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4195 spin_unlock(&pa->pa_lock);
4196 printk(KERN_ERR "PA:%u:%d:%u \n", i,
4199 ext4_unlock_group(sb, i);
4201 if (grp->bb_free == 0)
4203 printk(KERN_ERR "%u: %d/%d \n",
4204 i, grp->bb_free, grp->bb_fragments);
4206 printk(KERN_ERR "\n");
4209 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4216 * We use locality group preallocation for small size file. The size of the
4217 * file is determined by the current size or the resulting size after
4218 * allocation which ever is larger
4220 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4222 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4224 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4225 int bsbits = ac->ac_sb->s_blocksize_bits;
4228 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4231 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4234 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
4235 isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
4238 if ((size == isize) &&
4239 !ext4_fs_is_busy(sbi) &&
4240 (atomic_read(&ac->ac_inode->i_writecount) == 0)) {
4241 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
4245 if (sbi->s_mb_group_prealloc <= 0) {
4246 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4250 /* don't use group allocation for large files */
4251 size = max(size, isize);
4252 if (size > sbi->s_mb_stream_request) {
4253 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4257 BUG_ON(ac->ac_lg != NULL);
4259 * locality group prealloc space are per cpu. The reason for having
4260 * per cpu locality group is to reduce the contention between block
4261 * request from multiple CPUs.
4263 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
4265 /* we're going to use group allocation */
4266 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4268 /* serialize all allocations in the group */
4269 mutex_lock(&ac->ac_lg->lg_mutex);
4272 static noinline_for_stack int
4273 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
4274 struct ext4_allocation_request *ar)
4276 struct super_block *sb = ar->inode->i_sb;
4277 struct ext4_sb_info *sbi = EXT4_SB(sb);
4278 struct ext4_super_block *es = sbi->s_es;
4282 ext4_grpblk_t block;
4284 /* we can't allocate > group size */
4287 /* just a dirty hack to filter too big requests */
4288 if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
4289 len = EXT4_CLUSTERS_PER_GROUP(sb);
4291 /* start searching from the goal */
4293 if (goal < le32_to_cpu(es->s_first_data_block) ||
4294 goal >= ext4_blocks_count(es))
4295 goal = le32_to_cpu(es->s_first_data_block);
4296 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4298 /* set up allocation goals */
4299 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
4300 ac->ac_status = AC_STATUS_CONTINUE;
4302 ac->ac_inode = ar->inode;
4303 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
4304 ac->ac_o_ex.fe_group = group;
4305 ac->ac_o_ex.fe_start = block;
4306 ac->ac_o_ex.fe_len = len;
4307 ac->ac_g_ex = ac->ac_o_ex;
4308 ac->ac_flags = ar->flags;
4310 /* we have to define context: we'll we work with a file or
4311 * locality group. this is a policy, actually */
4312 ext4_mb_group_or_file(ac);
4314 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4315 "left: %u/%u, right %u/%u to %swritable\n",
4316 (unsigned) ar->len, (unsigned) ar->logical,
4317 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4318 (unsigned) ar->lleft, (unsigned) ar->pleft,
4319 (unsigned) ar->lright, (unsigned) ar->pright,
4320 atomic_read(&ar->inode->i_writecount) ? "" : "non-");
4325 static noinline_for_stack void
4326 ext4_mb_discard_lg_preallocations(struct super_block *sb,
4327 struct ext4_locality_group *lg,
4328 int order, int total_entries)
4330 ext4_group_t group = 0;
4331 struct ext4_buddy e4b;
4332 struct list_head discard_list;
4333 struct ext4_prealloc_space *pa, *tmp;
4335 mb_debug(1, "discard locality group preallocation\n");
4337 INIT_LIST_HEAD(&discard_list);
4339 spin_lock(&lg->lg_prealloc_lock);
4340 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
4342 spin_lock(&pa->pa_lock);
4343 if (atomic_read(&pa->pa_count)) {
4345 * This is the pa that we just used
4346 * for block allocation. So don't
4349 spin_unlock(&pa->pa_lock);
4352 if (pa->pa_deleted) {
4353 spin_unlock(&pa->pa_lock);
4356 /* only lg prealloc space */
4357 BUG_ON(pa->pa_type != MB_GROUP_PA);
4359 /* seems this one can be freed ... */
4361 spin_unlock(&pa->pa_lock);
4363 list_del_rcu(&pa->pa_inode_list);
4364 list_add(&pa->u.pa_tmp_list, &discard_list);
4367 if (total_entries <= 5) {
4369 * we want to keep only 5 entries
4370 * allowing it to grow to 8. This
4371 * mak sure we don't call discard
4372 * soon for this list.
4377 spin_unlock(&lg->lg_prealloc_lock);
4379 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
4382 group = ext4_get_group_number(sb, pa->pa_pstart);
4383 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4384 GFP_NOFS|__GFP_NOFAIL);
4386 ext4_error(sb, "Error %d loading buddy information for %u",
4390 ext4_lock_group(sb, group);
4391 list_del(&pa->pa_group_list);
4392 ext4_mb_release_group_pa(&e4b, pa);
4393 ext4_unlock_group(sb, group);
4395 ext4_mb_unload_buddy(&e4b);
4396 list_del(&pa->u.pa_tmp_list);
4397 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4402 * We have incremented pa_count. So it cannot be freed at this
4403 * point. Also we hold lg_mutex. So no parallel allocation is
4404 * possible from this lg. That means pa_free cannot be updated.
4406 * A parallel ext4_mb_discard_group_preallocations is possible.
4407 * which can cause the lg_prealloc_list to be updated.
4410 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
4412 int order, added = 0, lg_prealloc_count = 1;
4413 struct super_block *sb = ac->ac_sb;
4414 struct ext4_locality_group *lg = ac->ac_lg;
4415 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
4417 order = fls(pa->pa_free) - 1;
4418 if (order > PREALLOC_TB_SIZE - 1)
4419 /* The max size of hash table is PREALLOC_TB_SIZE */
4420 order = PREALLOC_TB_SIZE - 1;
4421 /* Add the prealloc space to lg */
4422 spin_lock(&lg->lg_prealloc_lock);
4423 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
4425 spin_lock(&tmp_pa->pa_lock);
4426 if (tmp_pa->pa_deleted) {
4427 spin_unlock(&tmp_pa->pa_lock);
4430 if (!added && pa->pa_free < tmp_pa->pa_free) {
4431 /* Add to the tail of the previous entry */
4432 list_add_tail_rcu(&pa->pa_inode_list,
4433 &tmp_pa->pa_inode_list);
4436 * we want to count the total
4437 * number of entries in the list
4440 spin_unlock(&tmp_pa->pa_lock);
4441 lg_prealloc_count++;
4444 list_add_tail_rcu(&pa->pa_inode_list,
4445 &lg->lg_prealloc_list[order]);
4446 spin_unlock(&lg->lg_prealloc_lock);
4448 /* Now trim the list to be not more than 8 elements */
4449 if (lg_prealloc_count > 8) {
4450 ext4_mb_discard_lg_preallocations(sb, lg,
4451 order, lg_prealloc_count);
4458 * release all resource we used in allocation
4460 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4462 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4463 struct ext4_prealloc_space *pa = ac->ac_pa;
4465 if (pa->pa_type == MB_GROUP_PA) {
4466 /* see comment in ext4_mb_use_group_pa() */
4467 spin_lock(&pa->pa_lock);
4468 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4469 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4470 pa->pa_free -= ac->ac_b_ex.fe_len;
4471 pa->pa_len -= ac->ac_b_ex.fe_len;
4472 spin_unlock(&pa->pa_lock);
4477 * We want to add the pa to the right bucket.
4478 * Remove it from the list and while adding
4479 * make sure the list to which we are adding
4482 if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) {
4483 spin_lock(pa->pa_obj_lock);
4484 list_del_rcu(&pa->pa_inode_list);
4485 spin_unlock(pa->pa_obj_lock);
4486 ext4_mb_add_n_trim(ac);
4488 ext4_mb_put_pa(ac, ac->ac_sb, pa);
4490 if (ac->ac_bitmap_page)
4491 put_page(ac->ac_bitmap_page);
4492 if (ac->ac_buddy_page)
4493 put_page(ac->ac_buddy_page);
4494 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4495 mutex_unlock(&ac->ac_lg->lg_mutex);
4496 ext4_mb_collect_stats(ac);
4500 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4502 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4506 trace_ext4_mb_discard_preallocations(sb, needed);
4507 for (i = 0; i < ngroups && needed > 0; i++) {
4508 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4517 * Main entry point into mballoc to allocate blocks
4518 * it tries to use preallocation first, then falls back
4519 * to usual allocation
4521 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4522 struct ext4_allocation_request *ar, int *errp)
4525 struct ext4_allocation_context *ac = NULL;
4526 struct ext4_sb_info *sbi;
4527 struct super_block *sb;
4528 ext4_fsblk_t block = 0;
4529 unsigned int inquota = 0;
4530 unsigned int reserv_clstrs = 0;
4533 sb = ar->inode->i_sb;
4536 trace_ext4_request_blocks(ar);
4538 /* Allow to use superuser reservation for quota file */
4539 if (ext4_is_quota_file(ar->inode))
4540 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
4542 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
4543 /* Without delayed allocation we need to verify
4544 * there is enough free blocks to do block allocation
4545 * and verify allocation doesn't exceed the quota limits.
4548 ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
4550 /* let others to free the space */
4552 ar->len = ar->len >> 1;
4558 reserv_clstrs = ar->len;
4559 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
4560 dquot_alloc_block_nofail(ar->inode,
4561 EXT4_C2B(sbi, ar->len));
4564 dquot_alloc_block(ar->inode,
4565 EXT4_C2B(sbi, ar->len))) {
4567 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4578 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
4585 *errp = ext4_mb_initialize_context(ac, ar);
4591 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4592 if (!ext4_mb_use_preallocated(ac)) {
4593 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4594 ext4_mb_normalize_request(ac, ar);
4596 /* allocate space in core */
4597 *errp = ext4_mb_regular_allocator(ac);
4599 goto discard_and_exit;
4601 /* as we've just preallocated more space than
4602 * user requested originally, we store allocated
4603 * space in a special descriptor */
4604 if (ac->ac_status == AC_STATUS_FOUND &&
4605 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4606 *errp = ext4_mb_new_preallocation(ac);
4609 ext4_discard_allocated_blocks(ac);
4613 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
4614 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
4616 ext4_discard_allocated_blocks(ac);
4619 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4620 ar->len = ac->ac_b_ex.fe_len;
4623 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
4631 ac->ac_b_ex.fe_len = 0;
4633 ext4_mb_show_ac(ac);
4635 ext4_mb_release_context(ac);
4638 kmem_cache_free(ext4_ac_cachep, ac);
4639 if (inquota && ar->len < inquota)
4640 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
4642 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
4643 /* release all the reserved blocks if non delalloc */
4644 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
4648 trace_ext4_allocate_blocks(ar, (unsigned long long)block);
4654 * We can merge two free data extents only if the physical blocks
4655 * are contiguous, AND the extents were freed by the same transaction,
4656 * AND the blocks are associated with the same group.
4658 static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
4659 struct ext4_free_data *entry,
4660 struct ext4_free_data *new_entry,
4661 struct rb_root *entry_rb_root)
4663 if ((entry->efd_tid != new_entry->efd_tid) ||
4664 (entry->efd_group != new_entry->efd_group))
4666 if (entry->efd_start_cluster + entry->efd_count ==
4667 new_entry->efd_start_cluster) {
4668 new_entry->efd_start_cluster = entry->efd_start_cluster;
4669 new_entry->efd_count += entry->efd_count;
4670 } else if (new_entry->efd_start_cluster + new_entry->efd_count ==
4671 entry->efd_start_cluster) {
4672 new_entry->efd_count += entry->efd_count;
4675 spin_lock(&sbi->s_md_lock);
4676 list_del(&entry->efd_list);
4677 spin_unlock(&sbi->s_md_lock);
4678 rb_erase(&entry->efd_node, entry_rb_root);
4679 kmem_cache_free(ext4_free_data_cachep, entry);
4682 static noinline_for_stack int
4683 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
4684 struct ext4_free_data *new_entry)
4686 ext4_group_t group = e4b->bd_group;
4687 ext4_grpblk_t cluster;
4688 ext4_grpblk_t clusters = new_entry->efd_count;
4689 struct ext4_free_data *entry;
4690 struct ext4_group_info *db = e4b->bd_info;
4691 struct super_block *sb = e4b->bd_sb;
4692 struct ext4_sb_info *sbi = EXT4_SB(sb);
4693 struct rb_node **n = &db->bb_free_root.rb_node, *node;
4694 struct rb_node *parent = NULL, *new_node;
4696 BUG_ON(!ext4_handle_valid(handle));
4697 BUG_ON(e4b->bd_bitmap_page == NULL);
4698 BUG_ON(e4b->bd_buddy_page == NULL);
4700 new_node = &new_entry->efd_node;
4701 cluster = new_entry->efd_start_cluster;
4704 /* first free block exent. We need to
4705 protect buddy cache from being freed,
4706 * otherwise we'll refresh it from
4707 * on-disk bitmap and lose not-yet-available
4709 get_page(e4b->bd_buddy_page);
4710 get_page(e4b->bd_bitmap_page);
4714 entry = rb_entry(parent, struct ext4_free_data, efd_node);
4715 if (cluster < entry->efd_start_cluster)
4717 else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
4718 n = &(*n)->rb_right;
4720 ext4_grp_locked_error(sb, group, 0,
4721 ext4_group_first_block_no(sb, group) +
4722 EXT4_C2B(sbi, cluster),
4723 "Block already on to-be-freed list");
4724 kmem_cache_free(ext4_free_data_cachep, new_entry);
4729 rb_link_node(new_node, parent, n);
4730 rb_insert_color(new_node, &db->bb_free_root);
4732 /* Now try to see the extent can be merged to left and right */
4733 node = rb_prev(new_node);
4735 entry = rb_entry(node, struct ext4_free_data, efd_node);
4736 ext4_try_merge_freed_extent(sbi, entry, new_entry,
4737 &(db->bb_free_root));
4740 node = rb_next(new_node);
4742 entry = rb_entry(node, struct ext4_free_data, efd_node);
4743 ext4_try_merge_freed_extent(sbi, entry, new_entry,
4744 &(db->bb_free_root));
4747 spin_lock(&sbi->s_md_lock);
4748 list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list);
4749 sbi->s_mb_free_pending += clusters;
4750 spin_unlock(&sbi->s_md_lock);
4755 * ext4_free_blocks() -- Free given blocks and update quota
4756 * @handle: handle for this transaction
4758 * @block: start physical block to free
4759 * @count: number of blocks to count
4760 * @flags: flags used by ext4_free_blocks
4762 void ext4_free_blocks(handle_t *handle, struct inode *inode,
4763 struct buffer_head *bh, ext4_fsblk_t block,
4764 unsigned long count, int flags)
4766 struct buffer_head *bitmap_bh = NULL;
4767 struct super_block *sb = inode->i_sb;
4768 struct ext4_group_desc *gdp;
4769 unsigned int overflow;
4771 struct buffer_head *gd_bh;
4772 ext4_group_t block_group;
4773 struct ext4_sb_info *sbi;
4774 struct ext4_buddy e4b;
4775 unsigned int count_clusters;
4782 BUG_ON(block != bh->b_blocknr);
4784 block = bh->b_blocknr;
4788 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
4789 !ext4_inode_block_valid(inode, block, count)) {
4790 ext4_error(sb, "Freeing blocks not in datazone - "
4791 "block = %llu, count = %lu", block, count);
4795 ext4_debug("freeing block %llu\n", block);
4796 trace_ext4_free_blocks(inode, block, count, flags);
4798 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
4801 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
4806 * If the extent to be freed does not begin on a cluster
4807 * boundary, we need to deal with partial clusters at the
4808 * beginning and end of the extent. Normally we will free
4809 * blocks at the beginning or the end unless we are explicitly
4810 * requested to avoid doing so.
4812 overflow = EXT4_PBLK_COFF(sbi, block);
4814 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
4815 overflow = sbi->s_cluster_ratio - overflow;
4817 if (count > overflow)
4826 overflow = EXT4_LBLK_COFF(sbi, count);
4828 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
4829 if (count > overflow)
4834 count += sbi->s_cluster_ratio - overflow;
4837 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
4839 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
4841 for (i = 0; i < count; i++) {
4844 bh = sb_find_get_block(inode->i_sb, block + i);
4845 ext4_forget(handle, is_metadata, inode, bh, block + i);
4851 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4853 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
4854 ext4_get_group_info(sb, block_group))))
4858 * Check to see if we are freeing blocks across a group
4861 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4862 overflow = EXT4_C2B(sbi, bit) + count -
4863 EXT4_BLOCKS_PER_GROUP(sb);
4866 count_clusters = EXT4_NUM_B2C(sbi, count);
4867 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
4868 if (IS_ERR(bitmap_bh)) {
4869 err = PTR_ERR(bitmap_bh);
4873 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
4879 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4880 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4881 in_range(block, ext4_inode_table(sb, gdp),
4882 sbi->s_itb_per_group) ||
4883 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4884 sbi->s_itb_per_group)) {
4886 ext4_error(sb, "Freeing blocks in system zone - "
4887 "Block = %llu, count = %lu", block, count);
4888 /* err = 0. ext4_std_error should be a no op */
4892 BUFFER_TRACE(bitmap_bh, "getting write access");
4893 err = ext4_journal_get_write_access(handle, bitmap_bh);
4898 * We are about to modify some metadata. Call the journal APIs
4899 * to unshare ->b_data if a currently-committing transaction is
4902 BUFFER_TRACE(gd_bh, "get_write_access");
4903 err = ext4_journal_get_write_access(handle, gd_bh);
4906 #ifdef AGGRESSIVE_CHECK
4909 for (i = 0; i < count_clusters; i++)
4910 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4913 trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters);
4915 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
4916 err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b,
4917 GFP_NOFS|__GFP_NOFAIL);
4922 * We need to make sure we don't reuse the freed block until after the
4923 * transaction is committed. We make an exception if the inode is to be
4924 * written in writeback mode since writeback mode has weak data
4925 * consistency guarantees.
4927 if (ext4_handle_valid(handle) &&
4928 ((flags & EXT4_FREE_BLOCKS_METADATA) ||
4929 !ext4_should_writeback_data(inode))) {
4930 struct ext4_free_data *new_entry;
4932 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
4935 new_entry = kmem_cache_alloc(ext4_free_data_cachep,
4936 GFP_NOFS|__GFP_NOFAIL);
4937 new_entry->efd_start_cluster = bit;
4938 new_entry->efd_group = block_group;
4939 new_entry->efd_count = count_clusters;
4940 new_entry->efd_tid = handle->h_transaction->t_tid;
4942 ext4_lock_group(sb, block_group);
4943 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
4944 ext4_mb_free_metadata(handle, &e4b, new_entry);
4946 /* need to update group_info->bb_free and bitmap
4947 * with group lock held. generate_buddy look at
4948 * them with group lock_held
4950 if (test_opt(sb, DISCARD)) {
4951 err = ext4_issue_discard(sb, block_group, bit,
4952 count_clusters, NULL);
4953 if (err && err != -EOPNOTSUPP)
4954 ext4_msg(sb, KERN_WARNING, "discard request in"
4955 " group:%d block:%d count:%lu failed"
4956 " with %d", block_group, bit, count,
4959 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
4961 ext4_lock_group(sb, block_group);
4962 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
4963 mb_free_blocks(inode, &e4b, bit, count_clusters);
4966 ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
4967 ext4_free_group_clusters_set(sb, gdp, ret);
4968 ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
4969 ext4_group_desc_csum_set(sb, block_group, gdp);
4970 ext4_unlock_group(sb, block_group);
4972 if (sbi->s_log_groups_per_flex) {
4973 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
4974 atomic64_add(count_clusters,
4975 &sbi_array_rcu_deref(sbi, s_flex_groups,
4976 flex_group)->free_clusters);
4979 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
4980 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
4981 percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
4983 ext4_mb_unload_buddy(&e4b);
4985 /* We dirtied the bitmap block */
4986 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4987 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
4989 /* And the group descriptor block */
4990 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4991 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
4995 if (overflow && !err) {
5003 ext4_std_error(sb, err);
5008 * ext4_group_add_blocks() -- Add given blocks to an existing group
5009 * @handle: handle to this transaction
5011 * @block: start physical block to add to the block group
5012 * @count: number of blocks to free
5014 * This marks the blocks as free in the bitmap and buddy.
5016 int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
5017 ext4_fsblk_t block, unsigned long count)
5019 struct buffer_head *bitmap_bh = NULL;
5020 struct buffer_head *gd_bh;
5021 ext4_group_t block_group;
5024 struct ext4_group_desc *desc;
5025 struct ext4_sb_info *sbi = EXT4_SB(sb);
5026 struct ext4_buddy e4b;
5027 int err = 0, ret, free_clusters_count;
5028 ext4_grpblk_t clusters_freed;
5029 ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
5030 ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
5031 unsigned long cluster_count = last_cluster - first_cluster + 1;
5033 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
5038 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
5040 * Check to see if we are freeing blocks across a group
5043 if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
5044 ext4_warning(sb, "too many blocks added to group %u",
5050 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
5051 if (IS_ERR(bitmap_bh)) {
5052 err = PTR_ERR(bitmap_bh);
5057 desc = ext4_get_group_desc(sb, block_group, &gd_bh);
5063 if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
5064 in_range(ext4_inode_bitmap(sb, desc), block, count) ||
5065 in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
5066 in_range(block + count - 1, ext4_inode_table(sb, desc),
5067 sbi->s_itb_per_group)) {
5068 ext4_error(sb, "Adding blocks in system zones - "
5069 "Block = %llu, count = %lu",
5075 BUFFER_TRACE(bitmap_bh, "getting write access");
5076 err = ext4_journal_get_write_access(handle, bitmap_bh);
5081 * We are about to modify some metadata. Call the journal APIs
5082 * to unshare ->b_data if a currently-committing transaction is
5085 BUFFER_TRACE(gd_bh, "get_write_access");
5086 err = ext4_journal_get_write_access(handle, gd_bh);
5090 for (i = 0, clusters_freed = 0; i < cluster_count; i++) {
5091 BUFFER_TRACE(bitmap_bh, "clear bit");
5092 if (!mb_test_bit(bit + i, bitmap_bh->b_data)) {
5093 ext4_error(sb, "bit already cleared for block %llu",
5094 (ext4_fsblk_t)(block + i));
5095 BUFFER_TRACE(bitmap_bh, "bit already cleared");
5101 err = ext4_mb_load_buddy(sb, block_group, &e4b);
5106 * need to update group_info->bb_free and bitmap
5107 * with group lock held. generate_buddy look at
5108 * them with group lock_held
5110 ext4_lock_group(sb, block_group);
5111 mb_clear_bits(bitmap_bh->b_data, bit, cluster_count);
5112 mb_free_blocks(NULL, &e4b, bit, cluster_count);
5113 free_clusters_count = clusters_freed +
5114 ext4_free_group_clusters(sb, desc);
5115 ext4_free_group_clusters_set(sb, desc, free_clusters_count);
5116 ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
5117 ext4_group_desc_csum_set(sb, block_group, desc);
5118 ext4_unlock_group(sb, block_group);
5119 percpu_counter_add(&sbi->s_freeclusters_counter,
5122 if (sbi->s_log_groups_per_flex) {
5123 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
5124 atomic64_add(clusters_freed,
5125 &sbi_array_rcu_deref(sbi, s_flex_groups,
5126 flex_group)->free_clusters);
5129 ext4_mb_unload_buddy(&e4b);
5131 /* We dirtied the bitmap block */
5132 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
5133 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
5135 /* And the group descriptor block */
5136 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
5137 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
5143 ext4_std_error(sb, err);
5148 * ext4_trim_extent -- function to TRIM one single free extent in the group
5149 * @sb: super block for the file system
5150 * @start: starting block of the free extent in the alloc. group
5151 * @count: number of blocks to TRIM
5152 * @group: alloc. group we are working with
5153 * @e4b: ext4 buddy for the group
5155 * Trim "count" blocks starting at "start" in the "group". To assure that no
5156 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5157 * be called with under the group lock.
5159 static int ext4_trim_extent(struct super_block *sb, int start, int count,
5160 ext4_group_t group, struct ext4_buddy *e4b)
5164 struct ext4_free_extent ex;
5167 trace_ext4_trim_extent(sb, group, start, count);
5169 assert_spin_locked(ext4_group_lock_ptr(sb, group));
5171 ex.fe_start = start;
5172 ex.fe_group = group;
5176 * Mark blocks used, so no one can reuse them while
5179 mb_mark_used(e4b, &ex);
5180 ext4_unlock_group(sb, group);
5181 ret = ext4_issue_discard(sb, group, start, count, NULL);
5182 ext4_lock_group(sb, group);
5183 mb_free_blocks(NULL, e4b, start, ex.fe_len);
5188 * ext4_trim_all_free -- function to trim all free space in alloc. group
5189 * @sb: super block for file system
5190 * @group: group to be trimmed
5191 * @start: first group block to examine
5192 * @max: last group block to examine
5193 * @minblocks: minimum extent block count
5195 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5196 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5200 * ext4_trim_all_free walks through group's block bitmap searching for free
5201 * extents. When the free extent is found, mark it as used in group buddy
5202 * bitmap. Then issue a TRIM command on this extent and free the extent in
5203 * the group buddy bitmap. This is done until whole group is scanned.
5205 static ext4_grpblk_t
5206 ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
5207 ext4_grpblk_t start, ext4_grpblk_t max,
5208 ext4_grpblk_t minblocks)
5211 ext4_grpblk_t next, count = 0, free_count = 0;
5212 struct ext4_buddy e4b;
5215 trace_ext4_trim_all_free(sb, group, start, max);
5217 ret = ext4_mb_load_buddy(sb, group, &e4b);
5219 ext4_warning(sb, "Error %d loading buddy information for %u",
5223 bitmap = e4b.bd_bitmap;
5225 ext4_lock_group(sb, group);
5226 if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
5227 minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
5230 start = (e4b.bd_info->bb_first_free > start) ?
5231 e4b.bd_info->bb_first_free : start;
5233 while (start <= max) {
5234 start = mb_find_next_zero_bit(bitmap, max + 1, start);
5237 next = mb_find_next_bit(bitmap, max + 1, start);
5239 if ((next - start) >= minblocks) {
5240 ret = ext4_trim_extent(sb, start,
5241 next - start, group, &e4b);
5242 if (ret && ret != -EOPNOTSUPP)
5245 count += next - start;
5247 free_count += next - start;
5250 if (fatal_signal_pending(current)) {
5251 count = -ERESTARTSYS;
5255 if (need_resched()) {
5256 ext4_unlock_group(sb, group);
5258 ext4_lock_group(sb, group);
5261 if ((e4b.bd_info->bb_free - free_count) < minblocks)
5267 EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
5270 ext4_unlock_group(sb, group);
5271 ext4_mb_unload_buddy(&e4b);
5273 ext4_debug("trimmed %d blocks in the group %d\n",
5280 * ext4_trim_fs() -- trim ioctl handle function
5281 * @sb: superblock for filesystem
5282 * @range: fstrim_range structure
5284 * start: First Byte to trim
5285 * len: number of Bytes to trim from start
5286 * minlen: minimum extent length in Bytes
5287 * ext4_trim_fs goes through all allocation groups containing Bytes from
5288 * start to start+len. For each such a group ext4_trim_all_free function
5289 * is invoked to trim all free space.
5291 int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
5293 struct request_queue *q = bdev_get_queue(sb->s_bdev);
5294 struct ext4_group_info *grp;
5295 ext4_group_t group, first_group, last_group;
5296 ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
5297 uint64_t start, end, minlen, trimmed = 0;
5298 ext4_fsblk_t first_data_blk =
5299 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
5300 ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es);
5303 start = range->start >> sb->s_blocksize_bits;
5304 end = start + (range->len >> sb->s_blocksize_bits) - 1;
5305 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
5306 range->minlen >> sb->s_blocksize_bits);
5308 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
5309 start >= max_blks ||
5310 range->len < sb->s_blocksize)
5312 /* No point to try to trim less than discard granularity */
5313 if (range->minlen < q->limits.discard_granularity) {
5314 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
5315 q->limits.discard_granularity >> sb->s_blocksize_bits);
5316 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb))
5319 if (end >= max_blks)
5321 if (end <= first_data_blk)
5323 if (start < first_data_blk)
5324 start = first_data_blk;
5326 /* Determine first and last group to examine based on start and end */
5327 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,
5328 &first_group, &first_cluster);
5329 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end,
5330 &last_group, &last_cluster);
5332 /* end now represents the last cluster to discard in this group */
5333 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5335 for (group = first_group; group <= last_group; group++) {
5336 grp = ext4_get_group_info(sb, group);
5337 /* We only do this if the grp has never been initialized */
5338 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
5339 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
5345 * For all the groups except the last one, last cluster will
5346 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5347 * change it for the last group, note that last_cluster is
5348 * already computed earlier by ext4_get_group_no_and_offset()
5350 if (group == last_group)
5353 if (grp->bb_free >= minlen) {
5354 cnt = ext4_trim_all_free(sb, group, first_cluster,
5364 * For every group except the first one, we are sure
5365 * that the first cluster to discard will be cluster #0.
5371 atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
5374 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
5378 /* Iterate all the free extents in the group. */
5380 ext4_mballoc_query_range(
5381 struct super_block *sb,
5383 ext4_grpblk_t start,
5385 ext4_mballoc_query_range_fn formatter,
5390 struct ext4_buddy e4b;
5393 error = ext4_mb_load_buddy(sb, group, &e4b);
5396 bitmap = e4b.bd_bitmap;
5398 ext4_lock_group(sb, group);
5400 start = (e4b.bd_info->bb_first_free > start) ?
5401 e4b.bd_info->bb_first_free : start;
5402 if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
5403 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5405 while (start <= end) {
5406 start = mb_find_next_zero_bit(bitmap, end + 1, start);
5409 next = mb_find_next_bit(bitmap, end + 1, start);
5411 ext4_unlock_group(sb, group);
5412 error = formatter(sb, group, start, next - start, priv);
5415 ext4_lock_group(sb, group);
5420 ext4_unlock_group(sb, group);
5422 ext4_mb_unload_buddy(&e4b);