2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public Licens
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 * mballoc.c contains the multiblocks allocation routines
25 #include <linux/debugfs.h>
26 #include <trace/events/ext4.h>
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 -> lenght for this prealloc space
73 * pa_free -> free space available in this prealloc space
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 make sure that
78 * that the 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 repreasented 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) withing 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_CACHE_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. Default value of s_mb_group_prealloc is
129 * 512 blocks. This can be tuned via
130 * /sys/fs/ext4/<partition/mb_group_prealloc. The value is represented in
131 * terms of number of blocks. If we have mounted the file system with -O
132 * stripe=<value> option the group prealloc request is normalized to the
133 * stripe value (sbi->s_stripe)
135 * The regular allocator(using the buddy cache) supports few tunables.
137 * /sys/fs/ext4/<partition>/mb_min_to_scan
138 * /sys/fs/ext4/<partition>/mb_max_to_scan
139 * /sys/fs/ext4/<partition>/mb_order2_req
141 * The regular allocator uses buddy scan only if the request len is power of
142 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
143 * value of s_mb_order2_reqs can be tuned via
144 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
145 * stripe size (sbi->s_stripe), we try to search for contigous block in
146 * stripe size. This should result in better allocation on RAID setups. If
147 * not, we search in the specific group using bitmap for best extents. The
148 * tunable min_to_scan and max_to_scan control the behaviour here.
149 * min_to_scan indicate how long the mballoc __must__ look for a best
150 * extent and max_to_scan indicates how long the mballoc __can__ look for a
151 * best extent in the found extents. Searching for the blocks starts with
152 * the group specified as the goal value in allocation context via
153 * ac_g_ex. Each group is first checked based on the criteria whether it
154 * can used for allocation. ext4_mb_good_group explains how the groups are
157 * Both the prealloc space are getting populated as above. So for the first
158 * request we will hit the buddy cache which will result in this prealloc
159 * space getting filled. The prealloc space is then later used for the
160 * subsequent request.
164 * mballoc operates on the following data:
166 * - in-core buddy (actually includes buddy and bitmap)
167 * - preallocation descriptors (PAs)
169 * there are two types of preallocations:
171 * assiged to specific inode and can be used for this inode only.
172 * it describes part of inode's space preallocated to specific
173 * physical blocks. any block from that preallocated can be used
174 * independent. the descriptor just tracks number of blocks left
175 * unused. so, before taking some block from descriptor, one must
176 * make sure corresponded logical block isn't allocated yet. this
177 * also means that freeing any block within descriptor's range
178 * must discard all preallocated blocks.
180 * assigned to specific locality group which does not translate to
181 * permanent set of inodes: inode can join and leave group. space
182 * from this type of preallocation can be used for any inode. thus
183 * it's consumed from the beginning to the end.
185 * relation between them can be expressed as:
186 * in-core buddy = on-disk bitmap + preallocation descriptors
188 * this mean blocks mballoc considers used are:
189 * - allocated blocks (persistent)
190 * - preallocated blocks (non-persistent)
192 * consistency in mballoc world means that at any time a block is either
193 * free or used in ALL structures. notice: "any time" should not be read
194 * literally -- time is discrete and delimited by locks.
196 * to keep it simple, we don't use block numbers, instead we count number of
197 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
199 * all operations can be expressed as:
200 * - init buddy: buddy = on-disk + PAs
201 * - new PA: buddy += N; PA = N
202 * - use inode PA: on-disk += N; PA -= N
203 * - discard inode PA buddy -= on-disk - PA; PA = 0
204 * - use locality group PA on-disk += N; PA -= N
205 * - discard locality group PA buddy -= PA; PA = 0
206 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
207 * is used in real operation because we can't know actual used
208 * bits from PA, only from on-disk bitmap
210 * if we follow this strict logic, then all operations above should be atomic.
211 * given some of them can block, we'd have to use something like semaphores
212 * killing performance on high-end SMP hardware. let's try to relax it using
213 * the following knowledge:
214 * 1) if buddy is referenced, it's already initialized
215 * 2) while block is used in buddy and the buddy is referenced,
216 * nobody can re-allocate that block
217 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
218 * bit set and PA claims same block, it's OK. IOW, one can set bit in
219 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
222 * so, now we're building a concurrency table:
225 * blocks for PA are allocated in the buddy, buddy must be referenced
226 * until PA is linked to allocation group to avoid concurrent buddy init
228 * we need to make sure that either on-disk bitmap or PA has uptodate data
229 * given (3) we care that PA-=N operation doesn't interfere with init
231 * the simplest way would be to have buddy initialized by the discard
232 * - use locality group PA
233 * again PA-=N must be serialized with init
234 * - discard locality group PA
235 * the simplest way would be to have buddy initialized by the discard
238 * i_data_sem serializes them
240 * discard process must wait until PA isn't used by another process
241 * - use locality group PA
242 * some mutex should serialize them
243 * - discard locality group PA
244 * discard process must wait until PA isn't used by another process
247 * i_data_sem or another mutex should serializes them
249 * discard process must wait until PA isn't used by another process
250 * - use locality group PA
251 * nothing wrong here -- they're different PAs covering different blocks
252 * - discard locality group PA
253 * discard process must wait until PA isn't used by another process
255 * now we're ready to make few consequences:
256 * - PA is referenced and while it is no discard is possible
257 * - PA is referenced until block isn't marked in on-disk bitmap
258 * - PA changes only after on-disk bitmap
259 * - discard must not compete with init. either init is done before
260 * any discard or they're serialized somehow
261 * - buddy init as sum of on-disk bitmap and PAs is done atomically
263 * a special case when we've used PA to emptiness. no need to modify buddy
264 * in this case, but we should care about concurrent init
269 * Logic in few words:
274 * mark bits in on-disk bitmap
277 * - use preallocation:
278 * find proper PA (per-inode or group)
280 * mark bits in on-disk bitmap
286 * mark bits in on-disk bitmap
289 * - discard preallocations in group:
291 * move them onto local list
292 * load on-disk bitmap
294 * remove PA from object (inode or locality group)
295 * mark free blocks in-core
297 * - discard inode's preallocations:
304 * - bitlock on a group (group)
305 * - object (inode/locality) (object)
316 * - release consumed pa:
321 * - generate in-core bitmap:
325 * - discard all for given object (inode, locality group):
330 * - discard all for given group:
337 static struct kmem_cache *ext4_pspace_cachep;
338 static struct kmem_cache *ext4_ac_cachep;
339 static struct kmem_cache *ext4_free_ext_cachep;
340 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
342 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
344 static void release_blocks_on_commit(journal_t *journal, transaction_t *txn);
346 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
348 #if BITS_PER_LONG == 64
349 *bit += ((unsigned long) addr & 7UL) << 3;
350 addr = (void *) ((unsigned long) addr & ~7UL);
351 #elif BITS_PER_LONG == 32
352 *bit += ((unsigned long) addr & 3UL) << 3;
353 addr = (void *) ((unsigned long) addr & ~3UL);
355 #error "how many bits you are?!"
360 static inline int mb_test_bit(int bit, void *addr)
363 * ext4_test_bit on architecture like powerpc
364 * needs unsigned long aligned address
366 addr = mb_correct_addr_and_bit(&bit, addr);
367 return ext4_test_bit(bit, addr);
370 static inline void mb_set_bit(int bit, void *addr)
372 addr = mb_correct_addr_and_bit(&bit, addr);
373 ext4_set_bit(bit, addr);
376 static inline void mb_clear_bit(int bit, void *addr)
378 addr = mb_correct_addr_and_bit(&bit, addr);
379 ext4_clear_bit(bit, addr);
382 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
384 int fix = 0, ret, tmpmax;
385 addr = mb_correct_addr_and_bit(&fix, addr);
389 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
395 static inline int mb_find_next_bit(void *addr, int max, int start)
397 int fix = 0, ret, tmpmax;
398 addr = mb_correct_addr_and_bit(&fix, addr);
402 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
408 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
412 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
415 if (order > e4b->bd_blkbits + 1) {
420 /* at order 0 we see each particular block */
421 *max = 1 << (e4b->bd_blkbits + 3);
423 return EXT4_MB_BITMAP(e4b);
425 bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
426 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
432 static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
433 int first, int count)
436 struct super_block *sb = e4b->bd_sb;
438 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
440 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
441 for (i = 0; i < count; i++) {
442 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
443 ext4_fsblk_t blocknr;
444 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
445 blocknr += first + i;
447 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
448 ext4_grp_locked_error(sb, e4b->bd_group,
449 __func__, "double-free of inode"
450 " %lu's block %llu(bit %u in group %u)",
451 inode ? inode->i_ino : 0, blocknr,
452 first + i, e4b->bd_group);
454 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
458 static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
462 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
464 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
465 for (i = 0; i < count; i++) {
466 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
467 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
471 static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
473 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
474 unsigned char *b1, *b2;
476 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
477 b2 = (unsigned char *) bitmap;
478 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
479 if (b1[i] != b2[i]) {
480 printk(KERN_ERR "corruption in group %u "
481 "at byte %u(%u): %x in copy != %x "
482 "on disk/prealloc\n",
483 e4b->bd_group, i, i * 8, b1[i], b2[i]);
491 static inline void mb_free_blocks_double(struct inode *inode,
492 struct ext4_buddy *e4b, int first, int count)
496 static inline void mb_mark_used_double(struct ext4_buddy *e4b,
497 int first, int count)
501 static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
507 #ifdef AGGRESSIVE_CHECK
509 #define MB_CHECK_ASSERT(assert) \
513 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
514 function, file, line, # assert); \
519 static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
520 const char *function, int line)
522 struct super_block *sb = e4b->bd_sb;
523 int order = e4b->bd_blkbits + 1;
530 struct ext4_group_info *grp;
533 struct list_head *cur;
538 static int mb_check_counter;
539 if (mb_check_counter++ % 100 != 0)
544 buddy = mb_find_buddy(e4b, order, &max);
545 MB_CHECK_ASSERT(buddy);
546 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
547 MB_CHECK_ASSERT(buddy2);
548 MB_CHECK_ASSERT(buddy != buddy2);
549 MB_CHECK_ASSERT(max * 2 == max2);
552 for (i = 0; i < max; i++) {
554 if (mb_test_bit(i, buddy)) {
555 /* only single bit in buddy2 may be 1 */
556 if (!mb_test_bit(i << 1, buddy2)) {
558 mb_test_bit((i<<1)+1, buddy2));
559 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
561 mb_test_bit(i << 1, buddy2));
566 /* both bits in buddy2 must be 0 */
567 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
568 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
570 for (j = 0; j < (1 << order); j++) {
571 k = (i * (1 << order)) + j;
573 !mb_test_bit(k, EXT4_MB_BITMAP(e4b)));
577 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
582 buddy = mb_find_buddy(e4b, 0, &max);
583 for (i = 0; i < max; i++) {
584 if (!mb_test_bit(i, buddy)) {
585 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
593 /* check used bits only */
594 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
595 buddy2 = mb_find_buddy(e4b, j, &max2);
597 MB_CHECK_ASSERT(k < max2);
598 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
601 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
602 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
604 grp = ext4_get_group_info(sb, e4b->bd_group);
605 buddy = mb_find_buddy(e4b, 0, &max);
606 list_for_each(cur, &grp->bb_prealloc_list) {
607 ext4_group_t groupnr;
608 struct ext4_prealloc_space *pa;
609 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
610 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
611 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
612 for (i = 0; i < pa->pa_len; i++)
613 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
617 #undef MB_CHECK_ASSERT
618 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
619 __FILE__, __func__, __LINE__)
621 #define mb_check_buddy(e4b)
624 /* FIXME!! need more doc */
625 static void ext4_mb_mark_free_simple(struct super_block *sb,
626 void *buddy, unsigned first, int len,
627 struct ext4_group_info *grp)
629 struct ext4_sb_info *sbi = EXT4_SB(sb);
632 unsigned short chunk;
633 unsigned short border;
635 BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb));
637 border = 2 << sb->s_blocksize_bits;
640 /* find how many blocks can be covered since this position */
641 max = ffs(first | border) - 1;
643 /* find how many blocks of power 2 we need to mark */
650 /* mark multiblock chunks only */
651 grp->bb_counters[min]++;
653 mb_clear_bit(first >> min,
654 buddy + sbi->s_mb_offsets[min]);
661 static noinline_for_stack
662 void ext4_mb_generate_buddy(struct super_block *sb,
663 void *buddy, void *bitmap, ext4_group_t group)
665 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
666 unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
667 unsigned short i = 0;
668 unsigned short first;
671 unsigned fragments = 0;
672 unsigned long long period = get_cycles();
674 /* initialize buddy from bitmap which is aggregation
675 * of on-disk bitmap and preallocations */
676 i = mb_find_next_zero_bit(bitmap, max, 0);
677 grp->bb_first_free = i;
681 i = mb_find_next_bit(bitmap, max, i);
685 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
687 grp->bb_counters[0]++;
689 i = mb_find_next_zero_bit(bitmap, max, i);
691 grp->bb_fragments = fragments;
693 if (free != grp->bb_free) {
694 ext4_grp_locked_error(sb, group, __func__,
695 "EXT4-fs: group %u: %u blocks in bitmap, %u in gd",
696 group, free, grp->bb_free);
698 * If we intent to continue, we consider group descritor
699 * corrupt and update bb_free using bitmap value
704 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
706 period = get_cycles() - period;
707 spin_lock(&EXT4_SB(sb)->s_bal_lock);
708 EXT4_SB(sb)->s_mb_buddies_generated++;
709 EXT4_SB(sb)->s_mb_generation_time += period;
710 spin_unlock(&EXT4_SB(sb)->s_bal_lock);
713 /* The buddy information is attached the buddy cache inode
714 * for convenience. The information regarding each group
715 * is loaded via ext4_mb_load_buddy. The information involve
716 * block bitmap and buddy information. The information are
717 * stored in the inode as
720 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
723 * one block each for bitmap and buddy information.
724 * So for each group we take up 2 blocks. A page can
725 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
726 * So it can have information regarding groups_per_page which
727 * is blocks_per_page/2
730 static int ext4_mb_init_cache(struct page *page, char *incore)
732 ext4_group_t ngroups;
738 ext4_group_t first_group;
740 struct super_block *sb;
741 struct buffer_head *bhs;
742 struct buffer_head **bh;
747 mb_debug(1, "init page %lu\n", page->index);
749 inode = page->mapping->host;
751 ngroups = ext4_get_groups_count(sb);
752 blocksize = 1 << inode->i_blkbits;
753 blocks_per_page = PAGE_CACHE_SIZE / blocksize;
755 groups_per_page = blocks_per_page >> 1;
756 if (groups_per_page == 0)
759 /* allocate buffer_heads to read bitmaps */
760 if (groups_per_page > 1) {
762 i = sizeof(struct buffer_head *) * groups_per_page;
763 bh = kzalloc(i, GFP_NOFS);
769 first_group = page->index * blocks_per_page / 2;
771 /* read all groups the page covers into the cache */
772 for (i = 0; i < groups_per_page; i++) {
773 struct ext4_group_desc *desc;
775 if (first_group + i >= ngroups)
779 desc = ext4_get_group_desc(sb, first_group + i, NULL);
784 bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc));
788 if (bitmap_uptodate(bh[i]))
792 if (bitmap_uptodate(bh[i])) {
793 unlock_buffer(bh[i]);
796 ext4_lock_group(sb, first_group + i);
797 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
798 ext4_init_block_bitmap(sb, bh[i],
799 first_group + i, desc);
800 set_bitmap_uptodate(bh[i]);
801 set_buffer_uptodate(bh[i]);
802 ext4_unlock_group(sb, first_group + i);
803 unlock_buffer(bh[i]);
806 ext4_unlock_group(sb, first_group + i);
807 if (buffer_uptodate(bh[i])) {
809 * if not uninit if bh is uptodate,
810 * bitmap is also uptodate
812 set_bitmap_uptodate(bh[i]);
813 unlock_buffer(bh[i]);
818 * submit the buffer_head for read. We can
819 * safely mark the bitmap as uptodate now.
820 * We do it here so the bitmap uptodate bit
821 * get set with buffer lock held.
823 set_bitmap_uptodate(bh[i]);
824 bh[i]->b_end_io = end_buffer_read_sync;
825 submit_bh(READ, bh[i]);
826 mb_debug(1, "read bitmap for group %u\n", first_group + i);
829 /* wait for I/O completion */
830 for (i = 0; i < groups_per_page && bh[i]; i++)
831 wait_on_buffer(bh[i]);
834 for (i = 0; i < groups_per_page && bh[i]; i++)
835 if (!buffer_uptodate(bh[i]))
839 first_block = page->index * blocks_per_page;
841 memset(page_address(page), 0xff, PAGE_CACHE_SIZE);
842 for (i = 0; i < blocks_per_page; i++) {
844 struct ext4_group_info *grinfo;
846 group = (first_block + i) >> 1;
847 if (group >= ngroups)
851 * data carry information regarding this
852 * particular group in the format specified
856 data = page_address(page) + (i * blocksize);
857 bitmap = bh[group - first_group]->b_data;
860 * We place the buddy block and bitmap block
863 if ((first_block + i) & 1) {
864 /* this is block of buddy */
865 BUG_ON(incore == NULL);
866 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
867 group, page->index, i * blocksize);
868 grinfo = ext4_get_group_info(sb, group);
869 grinfo->bb_fragments = 0;
870 memset(grinfo->bb_counters, 0,
871 sizeof(unsigned short)*(sb->s_blocksize_bits+2));
873 * incore got set to the group block bitmap below
875 ext4_lock_group(sb, group);
876 ext4_mb_generate_buddy(sb, data, incore, group);
877 ext4_unlock_group(sb, group);
880 /* this is block of bitmap */
881 BUG_ON(incore != NULL);
882 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
883 group, page->index, i * blocksize);
885 /* see comments in ext4_mb_put_pa() */
886 ext4_lock_group(sb, group);
887 memcpy(data, bitmap, blocksize);
889 /* mark all preallocated blks used in in-core bitmap */
890 ext4_mb_generate_from_pa(sb, data, group);
891 ext4_mb_generate_from_freelist(sb, data, group);
892 ext4_unlock_group(sb, group);
894 /* set incore so that the buddy information can be
895 * generated using this
900 SetPageUptodate(page);
904 for (i = 0; i < groups_per_page && bh[i]; i++)
912 static noinline_for_stack int
913 ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
914 struct ext4_buddy *e4b)
922 struct ext4_group_info *grp;
923 struct ext4_sb_info *sbi = EXT4_SB(sb);
924 struct inode *inode = sbi->s_buddy_cache;
926 mb_debug(1, "load group %u\n", group);
928 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
929 grp = ext4_get_group_info(sb, group);
931 e4b->bd_blkbits = sb->s_blocksize_bits;
932 e4b->bd_info = ext4_get_group_info(sb, group);
934 e4b->bd_group = group;
935 e4b->bd_buddy_page = NULL;
936 e4b->bd_bitmap_page = NULL;
937 e4b->alloc_semp = &grp->alloc_sem;
939 /* Take the read lock on the group alloc
940 * sem. This would make sure a parallel
941 * ext4_mb_init_group happening on other
942 * groups mapped by the page is blocked
943 * till we are done with allocation
945 down_read(e4b->alloc_semp);
948 * the buddy cache inode stores the block bitmap
949 * and buddy information in consecutive blocks.
950 * So for each group we need two blocks.
953 pnum = block / blocks_per_page;
954 poff = block % blocks_per_page;
956 /* we could use find_or_create_page(), but it locks page
957 * what we'd like to avoid in fast path ... */
958 page = find_get_page(inode->i_mapping, pnum);
959 if (page == NULL || !PageUptodate(page)) {
962 * drop the page reference and try
963 * to get the page with lock. If we
964 * are not uptodate that implies
965 * somebody just created the page but
966 * is yet to initialize the same. So
967 * wait for it to initialize.
969 page_cache_release(page);
970 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
972 BUG_ON(page->mapping != inode->i_mapping);
973 if (!PageUptodate(page)) {
974 ret = ext4_mb_init_cache(page, NULL);
979 mb_cmp_bitmaps(e4b, page_address(page) +
980 (poff * sb->s_blocksize));
985 if (page == NULL || !PageUptodate(page)) {
989 e4b->bd_bitmap_page = page;
990 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
991 mark_page_accessed(page);
994 pnum = block / blocks_per_page;
995 poff = block % blocks_per_page;
997 page = find_get_page(inode->i_mapping, pnum);
998 if (page == NULL || !PageUptodate(page)) {
1000 page_cache_release(page);
1001 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
1003 BUG_ON(page->mapping != inode->i_mapping);
1004 if (!PageUptodate(page)) {
1005 ret = ext4_mb_init_cache(page, e4b->bd_bitmap);
1014 if (page == NULL || !PageUptodate(page)) {
1018 e4b->bd_buddy_page = page;
1019 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1020 mark_page_accessed(page);
1022 BUG_ON(e4b->bd_bitmap_page == NULL);
1023 BUG_ON(e4b->bd_buddy_page == NULL);
1028 if (e4b->bd_bitmap_page)
1029 page_cache_release(e4b->bd_bitmap_page);
1030 if (e4b->bd_buddy_page)
1031 page_cache_release(e4b->bd_buddy_page);
1032 e4b->bd_buddy = NULL;
1033 e4b->bd_bitmap = NULL;
1035 /* Done with the buddy cache */
1036 up_read(e4b->alloc_semp);
1040 static void ext4_mb_release_desc(struct ext4_buddy *e4b)
1042 if (e4b->bd_bitmap_page)
1043 page_cache_release(e4b->bd_bitmap_page);
1044 if (e4b->bd_buddy_page)
1045 page_cache_release(e4b->bd_buddy_page);
1046 /* Done with the buddy cache */
1047 if (e4b->alloc_semp)
1048 up_read(e4b->alloc_semp);
1052 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1057 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
1058 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1060 bb = EXT4_MB_BUDDY(e4b);
1061 while (order <= e4b->bd_blkbits + 1) {
1063 if (!mb_test_bit(block, bb)) {
1064 /* this block is part of buddy of order 'order' */
1067 bb += 1 << (e4b->bd_blkbits - order);
1073 static void mb_clear_bits(void *bm, int cur, int len)
1079 if ((cur & 31) == 0 && (len - cur) >= 32) {
1080 /* fast path: clear whole word at once */
1081 addr = bm + (cur >> 3);
1086 mb_clear_bit(cur, bm);
1091 static void mb_set_bits(void *bm, int cur, int len)
1097 if ((cur & 31) == 0 && (len - cur) >= 32) {
1098 /* fast path: set whole word at once */
1099 addr = bm + (cur >> 3);
1104 mb_set_bit(cur, bm);
1109 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1110 int first, int count)
1117 struct super_block *sb = e4b->bd_sb;
1119 BUG_ON(first + count > (sb->s_blocksize << 3));
1120 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1121 mb_check_buddy(e4b);
1122 mb_free_blocks_double(inode, e4b, first, count);
1124 e4b->bd_info->bb_free += count;
1125 if (first < e4b->bd_info->bb_first_free)
1126 e4b->bd_info->bb_first_free = first;
1128 /* let's maintain fragments counter */
1130 block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b));
1131 if (first + count < EXT4_SB(sb)->s_mb_maxs[0])
1132 max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b));
1134 e4b->bd_info->bb_fragments--;
1135 else if (!block && !max)
1136 e4b->bd_info->bb_fragments++;
1138 /* let's maintain buddy itself */
1139 while (count-- > 0) {
1143 if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) {
1144 ext4_fsblk_t blocknr;
1145 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
1148 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1149 ext4_grp_locked_error(sb, e4b->bd_group,
1150 __func__, "double-free of inode"
1151 " %lu's block %llu(bit %u in group %u)",
1152 inode ? inode->i_ino : 0, blocknr, block,
1155 mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
1156 e4b->bd_info->bb_counters[order]++;
1158 /* start of the buddy */
1159 buddy = mb_find_buddy(e4b, order, &max);
1163 if (mb_test_bit(block, buddy) ||
1164 mb_test_bit(block + 1, buddy))
1167 /* both the buddies are free, try to coalesce them */
1168 buddy2 = mb_find_buddy(e4b, order + 1, &max);
1174 /* for special purposes, we don't set
1175 * free bits in bitmap */
1176 mb_set_bit(block, buddy);
1177 mb_set_bit(block + 1, buddy);
1179 e4b->bd_info->bb_counters[order]--;
1180 e4b->bd_info->bb_counters[order]--;
1184 e4b->bd_info->bb_counters[order]++;
1186 mb_clear_bit(block, buddy2);
1190 mb_check_buddy(e4b);
1193 static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
1194 int needed, struct ext4_free_extent *ex)
1201 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1204 buddy = mb_find_buddy(e4b, order, &max);
1205 BUG_ON(buddy == NULL);
1206 BUG_ON(block >= max);
1207 if (mb_test_bit(block, buddy)) {
1214 /* FIXME dorp order completely ? */
1215 if (likely(order == 0)) {
1216 /* find actual order */
1217 order = mb_find_order_for_block(e4b, block);
1218 block = block >> order;
1221 ex->fe_len = 1 << order;
1222 ex->fe_start = block << order;
1223 ex->fe_group = e4b->bd_group;
1225 /* calc difference from given start */
1226 next = next - ex->fe_start;
1228 ex->fe_start += next;
1230 while (needed > ex->fe_len &&
1231 (buddy = mb_find_buddy(e4b, order, &max))) {
1233 if (block + 1 >= max)
1236 next = (block + 1) * (1 << order);
1237 if (mb_test_bit(next, EXT4_MB_BITMAP(e4b)))
1240 ord = mb_find_order_for_block(e4b, next);
1243 block = next >> order;
1244 ex->fe_len += 1 << order;
1247 BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3)));
1251 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1257 int start = ex->fe_start;
1258 int len = ex->fe_len;
1263 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1264 BUG_ON(e4b->bd_group != ex->fe_group);
1265 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1266 mb_check_buddy(e4b);
1267 mb_mark_used_double(e4b, start, len);
1269 e4b->bd_info->bb_free -= len;
1270 if (e4b->bd_info->bb_first_free == start)
1271 e4b->bd_info->bb_first_free += len;
1273 /* let's maintain fragments counter */
1275 mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b));
1276 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1277 max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b));
1279 e4b->bd_info->bb_fragments++;
1280 else if (!mlen && !max)
1281 e4b->bd_info->bb_fragments--;
1283 /* let's maintain buddy itself */
1285 ord = mb_find_order_for_block(e4b, start);
1287 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1288 /* the whole chunk may be allocated at once! */
1290 buddy = mb_find_buddy(e4b, ord, &max);
1291 BUG_ON((start >> ord) >= max);
1292 mb_set_bit(start >> ord, buddy);
1293 e4b->bd_info->bb_counters[ord]--;
1300 /* store for history */
1302 ret = len | (ord << 16);
1304 /* we have to split large buddy */
1306 buddy = mb_find_buddy(e4b, ord, &max);
1307 mb_set_bit(start >> ord, buddy);
1308 e4b->bd_info->bb_counters[ord]--;
1311 cur = (start >> ord) & ~1U;
1312 buddy = mb_find_buddy(e4b, ord, &max);
1313 mb_clear_bit(cur, buddy);
1314 mb_clear_bit(cur + 1, buddy);
1315 e4b->bd_info->bb_counters[ord]++;
1316 e4b->bd_info->bb_counters[ord]++;
1319 mb_set_bits(EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
1320 mb_check_buddy(e4b);
1326 * Must be called under group lock!
1328 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1329 struct ext4_buddy *e4b)
1331 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1334 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1335 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1337 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1338 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1339 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1341 /* preallocation can change ac_b_ex, thus we store actually
1342 * allocated blocks for history */
1343 ac->ac_f_ex = ac->ac_b_ex;
1345 ac->ac_status = AC_STATUS_FOUND;
1346 ac->ac_tail = ret & 0xffff;
1347 ac->ac_buddy = ret >> 16;
1350 * take the page reference. We want the page to be pinned
1351 * so that we don't get a ext4_mb_init_cache_call for this
1352 * group until we update the bitmap. That would mean we
1353 * double allocate blocks. The reference is dropped
1354 * in ext4_mb_release_context
1356 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1357 get_page(ac->ac_bitmap_page);
1358 ac->ac_buddy_page = e4b->bd_buddy_page;
1359 get_page(ac->ac_buddy_page);
1360 /* on allocation we use ac to track the held semaphore */
1361 ac->alloc_semp = e4b->alloc_semp;
1362 e4b->alloc_semp = NULL;
1363 /* store last allocated for subsequent stream allocation */
1364 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
1365 spin_lock(&sbi->s_md_lock);
1366 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1367 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1368 spin_unlock(&sbi->s_md_lock);
1373 * regular allocator, for general purposes allocation
1376 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1377 struct ext4_buddy *e4b,
1380 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1381 struct ext4_free_extent *bex = &ac->ac_b_ex;
1382 struct ext4_free_extent *gex = &ac->ac_g_ex;
1383 struct ext4_free_extent ex;
1386 if (ac->ac_status == AC_STATUS_FOUND)
1389 * We don't want to scan for a whole year
1391 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1392 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1393 ac->ac_status = AC_STATUS_BREAK;
1398 * Haven't found good chunk so far, let's continue
1400 if (bex->fe_len < gex->fe_len)
1403 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1404 && bex->fe_group == e4b->bd_group) {
1405 /* recheck chunk's availability - we don't know
1406 * when it was found (within this lock-unlock
1408 max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex);
1409 if (max >= gex->fe_len) {
1410 ext4_mb_use_best_found(ac, e4b);
1417 * The routine checks whether found extent is good enough. If it is,
1418 * then the extent gets marked used and flag is set to the context
1419 * to stop scanning. Otherwise, the extent is compared with the
1420 * previous found extent and if new one is better, then it's stored
1421 * in the context. Later, the best found extent will be used, if
1422 * mballoc can't find good enough extent.
1424 * FIXME: real allocation policy is to be designed yet!
1426 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1427 struct ext4_free_extent *ex,
1428 struct ext4_buddy *e4b)
1430 struct ext4_free_extent *bex = &ac->ac_b_ex;
1431 struct ext4_free_extent *gex = &ac->ac_g_ex;
1433 BUG_ON(ex->fe_len <= 0);
1434 BUG_ON(ex->fe_len > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1435 BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1436 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1441 * The special case - take what you catch first
1443 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1445 ext4_mb_use_best_found(ac, e4b);
1450 * Let's check whether the chuck is good enough
1452 if (ex->fe_len == gex->fe_len) {
1454 ext4_mb_use_best_found(ac, e4b);
1459 * If this is first found extent, just store it in the context
1461 if (bex->fe_len == 0) {
1467 * If new found extent is better, store it in the context
1469 if (bex->fe_len < gex->fe_len) {
1470 /* if the request isn't satisfied, any found extent
1471 * larger than previous best one is better */
1472 if (ex->fe_len > bex->fe_len)
1474 } else if (ex->fe_len > gex->fe_len) {
1475 /* if the request is satisfied, then we try to find
1476 * an extent that still satisfy the request, but is
1477 * smaller than previous one */
1478 if (ex->fe_len < bex->fe_len)
1482 ext4_mb_check_limits(ac, e4b, 0);
1485 static noinline_for_stack
1486 int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1487 struct ext4_buddy *e4b)
1489 struct ext4_free_extent ex = ac->ac_b_ex;
1490 ext4_group_t group = ex.fe_group;
1494 BUG_ON(ex.fe_len <= 0);
1495 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1499 ext4_lock_group(ac->ac_sb, group);
1500 max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex);
1504 ext4_mb_use_best_found(ac, e4b);
1507 ext4_unlock_group(ac->ac_sb, group);
1508 ext4_mb_release_desc(e4b);
1513 static noinline_for_stack
1514 int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1515 struct ext4_buddy *e4b)
1517 ext4_group_t group = ac->ac_g_ex.fe_group;
1520 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1521 struct ext4_super_block *es = sbi->s_es;
1522 struct ext4_free_extent ex;
1524 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1527 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1531 ext4_lock_group(ac->ac_sb, group);
1532 max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start,
1533 ac->ac_g_ex.fe_len, &ex);
1535 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1538 start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) +
1539 ex.fe_start + le32_to_cpu(es->s_first_data_block);
1540 /* use do_div to get remainder (would be 64-bit modulo) */
1541 if (do_div(start, sbi->s_stripe) == 0) {
1544 ext4_mb_use_best_found(ac, e4b);
1546 } else if (max >= ac->ac_g_ex.fe_len) {
1547 BUG_ON(ex.fe_len <= 0);
1548 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1549 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1552 ext4_mb_use_best_found(ac, e4b);
1553 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1554 /* Sometimes, caller may want to merge even small
1555 * number of blocks to an existing extent */
1556 BUG_ON(ex.fe_len <= 0);
1557 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1558 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1561 ext4_mb_use_best_found(ac, e4b);
1563 ext4_unlock_group(ac->ac_sb, group);
1564 ext4_mb_release_desc(e4b);
1570 * The routine scans buddy structures (not bitmap!) from given order
1571 * to max order and tries to find big enough chunk to satisfy the req
1573 static noinline_for_stack
1574 void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1575 struct ext4_buddy *e4b)
1577 struct super_block *sb = ac->ac_sb;
1578 struct ext4_group_info *grp = e4b->bd_info;
1584 BUG_ON(ac->ac_2order <= 0);
1585 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1586 if (grp->bb_counters[i] == 0)
1589 buddy = mb_find_buddy(e4b, i, &max);
1590 BUG_ON(buddy == NULL);
1592 k = mb_find_next_zero_bit(buddy, max, 0);
1597 ac->ac_b_ex.fe_len = 1 << i;
1598 ac->ac_b_ex.fe_start = k << i;
1599 ac->ac_b_ex.fe_group = e4b->bd_group;
1601 ext4_mb_use_best_found(ac, e4b);
1603 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1605 if (EXT4_SB(sb)->s_mb_stats)
1606 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1613 * The routine scans the group and measures all found extents.
1614 * In order to optimize scanning, caller must pass number of
1615 * free blocks in the group, so the routine can know upper limit.
1617 static noinline_for_stack
1618 void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1619 struct ext4_buddy *e4b)
1621 struct super_block *sb = ac->ac_sb;
1622 void *bitmap = EXT4_MB_BITMAP(e4b);
1623 struct ext4_free_extent ex;
1627 free = e4b->bd_info->bb_free;
1630 i = e4b->bd_info->bb_first_free;
1632 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
1633 i = mb_find_next_zero_bit(bitmap,
1634 EXT4_BLOCKS_PER_GROUP(sb), i);
1635 if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
1637 * IF we have corrupt bitmap, we won't find any
1638 * free blocks even though group info says we
1639 * we have free blocks
1641 ext4_grp_locked_error(sb, e4b->bd_group,
1642 __func__, "%d free blocks as per "
1643 "group info. But bitmap says 0",
1648 mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex);
1649 BUG_ON(ex.fe_len <= 0);
1650 if (free < ex.fe_len) {
1651 ext4_grp_locked_error(sb, e4b->bd_group,
1652 __func__, "%d free blocks as per "
1653 "group info. But got %d blocks",
1656 * The number of free blocks differs. This mostly
1657 * indicate that the bitmap is corrupt. So exit
1658 * without claiming the space.
1663 ext4_mb_measure_extent(ac, &ex, e4b);
1669 ext4_mb_check_limits(ac, e4b, 1);
1673 * This is a special case for storages like raid5
1674 * we try to find stripe-aligned chunks for stripe-size requests
1675 * XXX should do so at least for multiples of stripe size as well
1677 static noinline_for_stack
1678 void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
1679 struct ext4_buddy *e4b)
1681 struct super_block *sb = ac->ac_sb;
1682 struct ext4_sb_info *sbi = EXT4_SB(sb);
1683 void *bitmap = EXT4_MB_BITMAP(e4b);
1684 struct ext4_free_extent ex;
1685 ext4_fsblk_t first_group_block;
1690 BUG_ON(sbi->s_stripe == 0);
1692 /* find first stripe-aligned block in group */
1693 first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb)
1694 + le32_to_cpu(sbi->s_es->s_first_data_block);
1695 a = first_group_block + sbi->s_stripe - 1;
1696 do_div(a, sbi->s_stripe);
1697 i = (a * sbi->s_stripe) - first_group_block;
1699 while (i < EXT4_BLOCKS_PER_GROUP(sb)) {
1700 if (!mb_test_bit(i, bitmap)) {
1701 max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex);
1702 if (max >= sbi->s_stripe) {
1705 ext4_mb_use_best_found(ac, e4b);
1713 static int ext4_mb_good_group(struct ext4_allocation_context *ac,
1714 ext4_group_t group, int cr)
1716 unsigned free, fragments;
1718 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
1719 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1721 BUG_ON(cr < 0 || cr >= 4);
1722 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp));
1724 free = grp->bb_free;
1725 fragments = grp->bb_fragments;
1733 BUG_ON(ac->ac_2order == 0);
1735 /* Avoid using the first bg of a flexgroup for data files */
1736 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
1737 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
1738 ((group % flex_size) == 0))
1741 bits = ac->ac_sb->s_blocksize_bits + 1;
1742 for (i = ac->ac_2order; i <= bits; i++)
1743 if (grp->bb_counters[i] > 0)
1747 if ((free / fragments) >= ac->ac_g_ex.fe_len)
1751 if (free >= ac->ac_g_ex.fe_len)
1764 * lock the group_info alloc_sem of all the groups
1765 * belonging to the same buddy cache page. This
1766 * make sure other parallel operation on the buddy
1767 * cache doesn't happen whild holding the buddy cache
1770 int ext4_mb_get_buddy_cache_lock(struct super_block *sb, ext4_group_t group)
1774 int blocks_per_page;
1775 int groups_per_page;
1776 ext4_group_t ngroups = ext4_get_groups_count(sb);
1777 ext4_group_t first_group;
1778 struct ext4_group_info *grp;
1780 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
1782 * the buddy cache inode stores the block bitmap
1783 * and buddy information in consecutive blocks.
1784 * So for each group we need two blocks.
1787 pnum = block / blocks_per_page;
1788 first_group = pnum * blocks_per_page / 2;
1790 groups_per_page = blocks_per_page >> 1;
1791 if (groups_per_page == 0)
1792 groups_per_page = 1;
1793 /* read all groups the page covers into the cache */
1794 for (i = 0; i < groups_per_page; i++) {
1796 if ((first_group + i) >= ngroups)
1798 grp = ext4_get_group_info(sb, first_group + i);
1799 /* take all groups write allocation
1800 * semaphore. This make sure there is
1801 * no block allocation going on in any
1804 down_write_nested(&grp->alloc_sem, i);
1809 void ext4_mb_put_buddy_cache_lock(struct super_block *sb,
1810 ext4_group_t group, int locked_group)
1814 int blocks_per_page;
1815 ext4_group_t first_group;
1816 struct ext4_group_info *grp;
1818 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
1820 * the buddy cache inode stores the block bitmap
1821 * and buddy information in consecutive blocks.
1822 * So for each group we need two blocks.
1825 pnum = block / blocks_per_page;
1826 first_group = pnum * blocks_per_page / 2;
1827 /* release locks on all the groups */
1828 for (i = 0; i < locked_group; i++) {
1830 grp = ext4_get_group_info(sb, first_group + i);
1831 /* take all groups write allocation
1832 * semaphore. This make sure there is
1833 * no block allocation going on in any
1836 up_write(&grp->alloc_sem);
1841 static noinline_for_stack
1842 int ext4_mb_init_group(struct super_block *sb, ext4_group_t group)
1847 int blocks_per_page;
1848 int block, pnum, poff;
1849 int num_grp_locked = 0;
1850 struct ext4_group_info *this_grp;
1851 struct ext4_sb_info *sbi = EXT4_SB(sb);
1852 struct inode *inode = sbi->s_buddy_cache;
1853 struct page *page = NULL, *bitmap_page = NULL;
1855 mb_debug(1, "init group %u\n", group);
1856 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
1857 this_grp = ext4_get_group_info(sb, group);
1859 * This ensures we don't add group
1860 * to this buddy cache via resize
1862 num_grp_locked = ext4_mb_get_buddy_cache_lock(sb, group);
1863 if (!EXT4_MB_GRP_NEED_INIT(this_grp)) {
1865 * somebody initialized the group
1866 * return without doing anything
1872 * the buddy cache inode stores the block bitmap
1873 * and buddy information in consecutive blocks.
1874 * So for each group we need two blocks.
1877 pnum = block / blocks_per_page;
1878 poff = block % blocks_per_page;
1879 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
1881 BUG_ON(page->mapping != inode->i_mapping);
1882 ret = ext4_mb_init_cache(page, NULL);
1889 if (page == NULL || !PageUptodate(page)) {
1893 mark_page_accessed(page);
1895 bitmap = page_address(page) + (poff * sb->s_blocksize);
1897 /* init buddy cache */
1899 pnum = block / blocks_per_page;
1900 poff = block % blocks_per_page;
1901 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
1902 if (page == bitmap_page) {
1904 * If both the bitmap and buddy are in
1905 * the same page we don't need to force
1910 BUG_ON(page->mapping != inode->i_mapping);
1911 ret = ext4_mb_init_cache(page, bitmap);
1918 if (page == NULL || !PageUptodate(page)) {
1922 mark_page_accessed(page);
1924 ext4_mb_put_buddy_cache_lock(sb, group, num_grp_locked);
1926 page_cache_release(bitmap_page);
1928 page_cache_release(page);
1932 static noinline_for_stack int
1933 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
1935 ext4_group_t ngroups, group, i;
1939 struct ext4_sb_info *sbi;
1940 struct super_block *sb;
1941 struct ext4_buddy e4b;
1945 ngroups = ext4_get_groups_count(sb);
1946 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1948 /* first, try the goal */
1949 err = ext4_mb_find_by_goal(ac, &e4b);
1950 if (err || ac->ac_status == AC_STATUS_FOUND)
1953 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
1957 * ac->ac2_order is set only if the fe_len is a power of 2
1958 * if ac2_order is set we also set criteria to 0 so that we
1959 * try exact allocation using buddy.
1961 i = fls(ac->ac_g_ex.fe_len);
1964 * We search using buddy data only if the order of the request
1965 * is greater than equal to the sbi_s_mb_order2_reqs
1966 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
1968 if (i >= sbi->s_mb_order2_reqs) {
1970 * This should tell if fe_len is exactly power of 2
1972 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
1973 ac->ac_2order = i - 1;
1976 bsbits = ac->ac_sb->s_blocksize_bits;
1978 /* if stream allocation is enabled, use global goal */
1979 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
1980 /* TBD: may be hot point */
1981 spin_lock(&sbi->s_md_lock);
1982 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
1983 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
1984 spin_unlock(&sbi->s_md_lock);
1987 /* Let's just scan groups to find more-less suitable blocks */
1988 cr = ac->ac_2order ? 0 : 1;
1990 * cr == 0 try to get exact allocation,
1991 * cr == 3 try to get anything
1994 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
1995 ac->ac_criteria = cr;
1997 * searching for the right group start
1998 * from the goal value specified
2000 group = ac->ac_g_ex.fe_group;
2002 for (i = 0; i < ngroups; group++, i++) {
2003 struct ext4_group_info *grp;
2004 struct ext4_group_desc *desc;
2006 if (group == ngroups)
2009 /* quick check to skip empty groups */
2010 grp = ext4_get_group_info(sb, group);
2011 if (grp->bb_free == 0)
2015 * if the group is already init we check whether it is
2016 * a good group and if not we don't load the buddy
2018 if (EXT4_MB_GRP_NEED_INIT(grp)) {
2020 * we need full data about the group
2021 * to make a good selection
2023 err = ext4_mb_init_group(sb, group);
2029 * If the particular group doesn't satisfy our
2030 * criteria we continue with the next group
2032 if (!ext4_mb_good_group(ac, group, cr))
2035 err = ext4_mb_load_buddy(sb, group, &e4b);
2039 ext4_lock_group(sb, group);
2040 if (!ext4_mb_good_group(ac, group, cr)) {
2041 /* someone did allocation from this group */
2042 ext4_unlock_group(sb, group);
2043 ext4_mb_release_desc(&e4b);
2047 ac->ac_groups_scanned++;
2048 desc = ext4_get_group_desc(sb, group, NULL);
2050 ext4_mb_simple_scan_group(ac, &e4b);
2052 ac->ac_g_ex.fe_len == sbi->s_stripe)
2053 ext4_mb_scan_aligned(ac, &e4b);
2055 ext4_mb_complex_scan_group(ac, &e4b);
2057 ext4_unlock_group(sb, group);
2058 ext4_mb_release_desc(&e4b);
2060 if (ac->ac_status != AC_STATUS_CONTINUE)
2065 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2066 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2068 * We've been searching too long. Let's try to allocate
2069 * the best chunk we've found so far
2072 ext4_mb_try_best_found(ac, &e4b);
2073 if (ac->ac_status != AC_STATUS_FOUND) {
2075 * Someone more lucky has already allocated it.
2076 * The only thing we can do is just take first
2078 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2080 ac->ac_b_ex.fe_group = 0;
2081 ac->ac_b_ex.fe_start = 0;
2082 ac->ac_b_ex.fe_len = 0;
2083 ac->ac_status = AC_STATUS_CONTINUE;
2084 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2086 atomic_inc(&sbi->s_mb_lost_chunks);
2094 #ifdef EXT4_MB_HISTORY
2095 struct ext4_mb_proc_session {
2096 struct ext4_mb_history *history;
2097 struct super_block *sb;
2102 static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s,
2103 struct ext4_mb_history *hs,
2106 if (hs == s->history + s->max)
2108 if (!first && hs == s->history + s->start)
2110 while (hs->orig.fe_len == 0) {
2112 if (hs == s->history + s->max)
2114 if (hs == s->history + s->start)
2120 static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos)
2122 struct ext4_mb_proc_session *s = seq->private;
2123 struct ext4_mb_history *hs;
2127 return SEQ_START_TOKEN;
2128 hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1);
2131 while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL);
2135 static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v,
2138 struct ext4_mb_proc_session *s = seq->private;
2139 struct ext4_mb_history *hs = v;
2142 if (v == SEQ_START_TOKEN)
2143 return ext4_mb_history_skip_empty(s, s->history + s->start, 1);
2145 return ext4_mb_history_skip_empty(s, ++hs, 0);
2148 static int ext4_mb_seq_history_show(struct seq_file *seq, void *v)
2150 char buf[25], buf2[25], buf3[25], *fmt;
2151 struct ext4_mb_history *hs = v;
2153 if (v == SEQ_START_TOKEN) {
2154 seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s "
2155 "%-5s %-2s %-6s %-5s %-5s %-6s\n",
2156 "pid", "inode", "original", "goal", "result", "found",
2157 "grps", "cr", "flags", "merge", "tail", "broken");
2161 if (hs->op == EXT4_MB_HISTORY_ALLOC) {
2162 fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
2163 "0x%04x %-5s %-5u %-6u\n";
2164 sprintf(buf2, "%u/%d/%u@%u", hs->result.fe_group,
2165 hs->result.fe_start, hs->result.fe_len,
2166 hs->result.fe_logical);
2167 sprintf(buf, "%u/%d/%u@%u", hs->orig.fe_group,
2168 hs->orig.fe_start, hs->orig.fe_len,
2169 hs->orig.fe_logical);
2170 sprintf(buf3, "%u/%d/%u@%u", hs->goal.fe_group,
2171 hs->goal.fe_start, hs->goal.fe_len,
2172 hs->goal.fe_logical);
2173 seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2,
2174 hs->found, hs->groups, hs->cr, hs->flags,
2175 hs->merged ? "M" : "", hs->tail,
2176 hs->buddy ? 1 << hs->buddy : 0);
2177 } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) {
2178 fmt = "%-5u %-8u %-23s %-23s %-23s\n";
2179 sprintf(buf2, "%u/%d/%u@%u", hs->result.fe_group,
2180 hs->result.fe_start, hs->result.fe_len,
2181 hs->result.fe_logical);
2182 sprintf(buf, "%u/%d/%u@%u", hs->orig.fe_group,
2183 hs->orig.fe_start, hs->orig.fe_len,
2184 hs->orig.fe_logical);
2185 seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2);
2186 } else if (hs->op == EXT4_MB_HISTORY_DISCARD) {
2187 sprintf(buf2, "%u/%d/%u", hs->result.fe_group,
2188 hs->result.fe_start, hs->result.fe_len);
2189 seq_printf(seq, "%-5u %-8u %-23s discard\n",
2190 hs->pid, hs->ino, buf2);
2191 } else if (hs->op == EXT4_MB_HISTORY_FREE) {
2192 sprintf(buf2, "%u/%d/%u", hs->result.fe_group,
2193 hs->result.fe_start, hs->result.fe_len);
2194 seq_printf(seq, "%-5u %-8u %-23s free\n",
2195 hs->pid, hs->ino, buf2);
2200 static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v)
2204 static struct seq_operations ext4_mb_seq_history_ops = {
2205 .start = ext4_mb_seq_history_start,
2206 .next = ext4_mb_seq_history_next,
2207 .stop = ext4_mb_seq_history_stop,
2208 .show = ext4_mb_seq_history_show,
2211 static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
2213 struct super_block *sb = PDE(inode)->data;
2214 struct ext4_sb_info *sbi = EXT4_SB(sb);
2215 struct ext4_mb_proc_session *s;
2219 if (unlikely(sbi->s_mb_history == NULL))
2221 s = kmalloc(sizeof(*s), GFP_KERNEL);
2225 size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max;
2226 s->history = kmalloc(size, GFP_KERNEL);
2227 if (s->history == NULL) {
2232 spin_lock(&sbi->s_mb_history_lock);
2233 memcpy(s->history, sbi->s_mb_history, size);
2234 s->max = sbi->s_mb_history_max;
2235 s->start = sbi->s_mb_history_cur % s->max;
2236 spin_unlock(&sbi->s_mb_history_lock);
2238 rc = seq_open(file, &ext4_mb_seq_history_ops);
2240 struct seq_file *m = (struct seq_file *)file->private_data;
2250 static int ext4_mb_seq_history_release(struct inode *inode, struct file *file)
2252 struct seq_file *seq = (struct seq_file *)file->private_data;
2253 struct ext4_mb_proc_session *s = seq->private;
2256 return seq_release(inode, file);
2259 static ssize_t ext4_mb_seq_history_write(struct file *file,
2260 const char __user *buffer,
2261 size_t count, loff_t *ppos)
2263 struct seq_file *seq = (struct seq_file *)file->private_data;
2264 struct ext4_mb_proc_session *s = seq->private;
2265 struct super_block *sb = s->sb;
2269 if (count >= sizeof(str)) {
2270 printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n",
2271 "mb_history", (int)sizeof(str));
2275 if (copy_from_user(str, buffer, count))
2278 value = simple_strtol(str, NULL, 0);
2281 EXT4_SB(sb)->s_mb_history_filter = value;
2286 static struct file_operations ext4_mb_seq_history_fops = {
2287 .owner = THIS_MODULE,
2288 .open = ext4_mb_seq_history_open,
2290 .write = ext4_mb_seq_history_write,
2291 .llseek = seq_lseek,
2292 .release = ext4_mb_seq_history_release,
2295 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2297 struct super_block *sb = seq->private;
2300 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2303 return (void *) ((unsigned long) group);
2306 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2308 struct super_block *sb = seq->private;
2312 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2315 return (void *) ((unsigned long) group);
2318 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2320 struct super_block *sb = seq->private;
2321 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
2324 struct ext4_buddy e4b;
2326 struct ext4_group_info info;
2327 unsigned short counters[16];
2332 seq_printf(seq, "#%-5s: %-5s %-5s %-5s "
2333 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2334 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2335 "group", "free", "frags", "first",
2336 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2337 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2339 i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2340 sizeof(struct ext4_group_info);
2341 err = ext4_mb_load_buddy(sb, group, &e4b);
2343 seq_printf(seq, "#%-5u: I/O error\n", group);
2346 ext4_lock_group(sb, group);
2347 memcpy(&sg, ext4_get_group_info(sb, group), i);
2348 ext4_unlock_group(sb, group);
2349 ext4_mb_release_desc(&e4b);
2351 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
2352 sg.info.bb_fragments, sg.info.bb_first_free);
2353 for (i = 0; i <= 13; i++)
2354 seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ?
2355 sg.info.bb_counters[i] : 0);
2356 seq_printf(seq, " ]\n");
2361 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2365 static struct seq_operations ext4_mb_seq_groups_ops = {
2366 .start = ext4_mb_seq_groups_start,
2367 .next = ext4_mb_seq_groups_next,
2368 .stop = ext4_mb_seq_groups_stop,
2369 .show = ext4_mb_seq_groups_show,
2372 static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
2374 struct super_block *sb = PDE(inode)->data;
2377 rc = seq_open(file, &ext4_mb_seq_groups_ops);
2379 struct seq_file *m = (struct seq_file *)file->private_data;
2386 static struct file_operations ext4_mb_seq_groups_fops = {
2387 .owner = THIS_MODULE,
2388 .open = ext4_mb_seq_groups_open,
2390 .llseek = seq_lseek,
2391 .release = seq_release,
2394 static void ext4_mb_history_release(struct super_block *sb)
2396 struct ext4_sb_info *sbi = EXT4_SB(sb);
2398 if (sbi->s_proc != NULL) {
2399 remove_proc_entry("mb_groups", sbi->s_proc);
2400 if (sbi->s_mb_history_max)
2401 remove_proc_entry("mb_history", sbi->s_proc);
2403 kfree(sbi->s_mb_history);
2406 static void ext4_mb_history_init(struct super_block *sb)
2408 struct ext4_sb_info *sbi = EXT4_SB(sb);
2411 if (sbi->s_proc != NULL) {
2412 if (sbi->s_mb_history_max)
2413 proc_create_data("mb_history", S_IRUGO, sbi->s_proc,
2414 &ext4_mb_seq_history_fops, sb);
2415 proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
2416 &ext4_mb_seq_groups_fops, sb);
2419 sbi->s_mb_history_cur = 0;
2420 spin_lock_init(&sbi->s_mb_history_lock);
2421 i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
2422 sbi->s_mb_history = i ? kzalloc(i, GFP_KERNEL) : NULL;
2423 /* if we can't allocate history, then we simple won't use it */
2426 static noinline_for_stack void
2427 ext4_mb_store_history(struct ext4_allocation_context *ac)
2429 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2430 struct ext4_mb_history h;
2432 if (sbi->s_mb_history == NULL)
2435 if (!(ac->ac_op & sbi->s_mb_history_filter))
2439 h.pid = current->pid;
2440 h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
2441 h.orig = ac->ac_o_ex;
2442 h.result = ac->ac_b_ex;
2443 h.flags = ac->ac_flags;
2444 h.found = ac->ac_found;
2445 h.groups = ac->ac_groups_scanned;
2446 h.cr = ac->ac_criteria;
2447 h.tail = ac->ac_tail;
2448 h.buddy = ac->ac_buddy;
2450 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
2451 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
2452 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
2454 h.goal = ac->ac_g_ex;
2455 h.result = ac->ac_f_ex;
2458 spin_lock(&sbi->s_mb_history_lock);
2459 memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
2460 if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
2461 sbi->s_mb_history_cur = 0;
2462 spin_unlock(&sbi->s_mb_history_lock);
2466 #define ext4_mb_history_release(sb)
2467 #define ext4_mb_history_init(sb)
2471 /* Create and initialize ext4_group_info data for the given group. */
2472 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
2473 struct ext4_group_desc *desc)
2477 struct ext4_sb_info *sbi = EXT4_SB(sb);
2478 struct ext4_group_info **meta_group_info;
2481 * First check if this group is the first of a reserved block.
2482 * If it's true, we have to allocate a new table of pointers
2483 * to ext4_group_info structures
2485 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2486 metalen = sizeof(*meta_group_info) <<
2487 EXT4_DESC_PER_BLOCK_BITS(sb);
2488 meta_group_info = kmalloc(metalen, GFP_KERNEL);
2489 if (meta_group_info == NULL) {
2490 printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
2492 goto exit_meta_group_info;
2494 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] =
2499 * calculate needed size. if change bb_counters size,
2500 * don't forget about ext4_mb_generate_buddy()
2502 len = offsetof(typeof(**meta_group_info),
2503 bb_counters[sb->s_blocksize_bits + 2]);
2506 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
2507 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
2509 meta_group_info[i] = kzalloc(len, GFP_KERNEL);
2510 if (meta_group_info[i] == NULL) {
2511 printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
2512 goto exit_group_info;
2514 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2515 &(meta_group_info[i]->bb_state));
2518 * initialize bb_free to be able to skip
2519 * empty groups without initialization
2521 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2522 meta_group_info[i]->bb_free =
2523 ext4_free_blocks_after_init(sb, group, desc);
2525 meta_group_info[i]->bb_free =
2526 ext4_free_blks_count(sb, desc);
2529 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
2530 init_rwsem(&meta_group_info[i]->alloc_sem);
2531 meta_group_info[i]->bb_free_root.rb_node = NULL;
2535 struct buffer_head *bh;
2536 meta_group_info[i]->bb_bitmap =
2537 kmalloc(sb->s_blocksize, GFP_KERNEL);
2538 BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
2539 bh = ext4_read_block_bitmap(sb, group);
2541 memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
2550 /* If a meta_group_info table has been allocated, release it now */
2551 if (group % EXT4_DESC_PER_BLOCK(sb) == 0)
2552 kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
2553 exit_meta_group_info:
2555 } /* ext4_mb_add_groupinfo */
2558 * Update an existing group.
2559 * This function is used for online resize
2561 void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add)
2563 grp->bb_free += add;
2566 static int ext4_mb_init_backend(struct super_block *sb)
2568 ext4_group_t ngroups = ext4_get_groups_count(sb);
2570 struct ext4_sb_info *sbi = EXT4_SB(sb);
2571 struct ext4_super_block *es = sbi->s_es;
2572 int num_meta_group_infos;
2573 int num_meta_group_infos_max;
2575 struct ext4_group_desc *desc;
2577 /* This is the number of blocks used by GDT */
2578 num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) -
2579 1) >> EXT4_DESC_PER_BLOCK_BITS(sb);
2582 * This is the total number of blocks used by GDT including
2583 * the number of reserved blocks for GDT.
2584 * The s_group_info array is allocated with this value
2585 * to allow a clean online resize without a complex
2586 * manipulation of pointer.
2587 * The drawback is the unused memory when no resize
2588 * occurs but it's very low in terms of pages
2589 * (see comments below)
2590 * Need to handle this properly when META_BG resizing is allowed
2592 num_meta_group_infos_max = num_meta_group_infos +
2593 le16_to_cpu(es->s_reserved_gdt_blocks);
2596 * array_size is the size of s_group_info array. We round it
2597 * to the next power of two because this approximation is done
2598 * internally by kmalloc so we can have some more memory
2599 * for free here (e.g. may be used for META_BG resize).
2602 while (array_size < sizeof(*sbi->s_group_info) *
2603 num_meta_group_infos_max)
2604 array_size = array_size << 1;
2605 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2606 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2607 * So a two level scheme suffices for now. */
2608 sbi->s_group_info = kmalloc(array_size, GFP_KERNEL);
2609 if (sbi->s_group_info == NULL) {
2610 printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
2613 sbi->s_buddy_cache = new_inode(sb);
2614 if (sbi->s_buddy_cache == NULL) {
2615 printk(KERN_ERR "EXT4-fs: can't get new inode\n");
2618 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2619 for (i = 0; i < ngroups; i++) {
2620 desc = ext4_get_group_desc(sb, i, NULL);
2623 "EXT4-fs: can't read descriptor %u\n", i);
2626 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
2634 kfree(ext4_get_group_info(sb, i));
2635 i = num_meta_group_infos;
2637 kfree(sbi->s_group_info[i]);
2638 iput(sbi->s_buddy_cache);
2640 kfree(sbi->s_group_info);
2644 int ext4_mb_init(struct super_block *sb, int needs_recovery)
2646 struct ext4_sb_info *sbi = EXT4_SB(sb);
2652 i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
2654 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2655 if (sbi->s_mb_offsets == NULL) {
2659 i = (sb->s_blocksize_bits + 2) * sizeof(unsigned int);
2660 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2661 if (sbi->s_mb_maxs == NULL) {
2662 kfree(sbi->s_mb_offsets);
2666 /* order 0 is regular bitmap */
2667 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2668 sbi->s_mb_offsets[0] = 0;
2672 max = sb->s_blocksize << 2;
2674 sbi->s_mb_offsets[i] = offset;
2675 sbi->s_mb_maxs[i] = max;
2676 offset += 1 << (sb->s_blocksize_bits - i);
2679 } while (i <= sb->s_blocksize_bits + 1);
2681 /* init file for buddy data */
2682 ret = ext4_mb_init_backend(sb);
2684 kfree(sbi->s_mb_offsets);
2685 kfree(sbi->s_mb_maxs);
2689 spin_lock_init(&sbi->s_md_lock);
2690 spin_lock_init(&sbi->s_bal_lock);
2692 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2693 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2694 sbi->s_mb_stats = MB_DEFAULT_STATS;
2695 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2696 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2697 sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
2698 sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
2700 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
2701 if (sbi->s_locality_groups == NULL) {
2702 kfree(sbi->s_mb_offsets);
2703 kfree(sbi->s_mb_maxs);
2706 for_each_possible_cpu(i) {
2707 struct ext4_locality_group *lg;
2708 lg = per_cpu_ptr(sbi->s_locality_groups, i);
2709 mutex_init(&lg->lg_mutex);
2710 for (j = 0; j < PREALLOC_TB_SIZE; j++)
2711 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
2712 spin_lock_init(&lg->lg_prealloc_lock);
2715 ext4_mb_history_init(sb);
2718 sbi->s_journal->j_commit_callback = release_blocks_on_commit;
2720 printk(KERN_INFO "EXT4-fs: mballoc enabled\n");
2724 /* need to called with the ext4 group lock held */
2725 static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2727 struct ext4_prealloc_space *pa;
2728 struct list_head *cur, *tmp;
2731 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2732 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2733 list_del(&pa->pa_group_list);
2735 kmem_cache_free(ext4_pspace_cachep, pa);
2738 mb_debug(1, "mballoc: %u PAs left\n", count);
2742 int ext4_mb_release(struct super_block *sb)
2744 ext4_group_t ngroups = ext4_get_groups_count(sb);
2746 int num_meta_group_infos;
2747 struct ext4_group_info *grinfo;
2748 struct ext4_sb_info *sbi = EXT4_SB(sb);
2750 if (sbi->s_group_info) {
2751 for (i = 0; i < ngroups; i++) {
2752 grinfo = ext4_get_group_info(sb, i);
2754 kfree(grinfo->bb_bitmap);
2756 ext4_lock_group(sb, i);
2757 ext4_mb_cleanup_pa(grinfo);
2758 ext4_unlock_group(sb, i);
2761 num_meta_group_infos = (ngroups +
2762 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2763 EXT4_DESC_PER_BLOCK_BITS(sb);
2764 for (i = 0; i < num_meta_group_infos; i++)
2765 kfree(sbi->s_group_info[i]);
2766 kfree(sbi->s_group_info);
2768 kfree(sbi->s_mb_offsets);
2769 kfree(sbi->s_mb_maxs);
2770 if (sbi->s_buddy_cache)
2771 iput(sbi->s_buddy_cache);
2772 if (sbi->s_mb_stats) {
2774 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2775 atomic_read(&sbi->s_bal_allocated),
2776 atomic_read(&sbi->s_bal_reqs),
2777 atomic_read(&sbi->s_bal_success));
2779 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2780 "%u 2^N hits, %u breaks, %u lost\n",
2781 atomic_read(&sbi->s_bal_ex_scanned),
2782 atomic_read(&sbi->s_bal_goals),
2783 atomic_read(&sbi->s_bal_2orders),
2784 atomic_read(&sbi->s_bal_breaks),
2785 atomic_read(&sbi->s_mb_lost_chunks));
2787 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2788 sbi->s_mb_buddies_generated++,
2789 sbi->s_mb_generation_time);
2791 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2792 atomic_read(&sbi->s_mb_preallocated),
2793 atomic_read(&sbi->s_mb_discarded));
2796 free_percpu(sbi->s_locality_groups);
2797 ext4_mb_history_release(sb);
2803 * This function is called by the jbd2 layer once the commit has finished,
2804 * so we know we can free the blocks that were released with that commit.
2806 static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
2808 struct super_block *sb = journal->j_private;
2809 struct ext4_buddy e4b;
2810 struct ext4_group_info *db;
2811 int err, count = 0, count2 = 0;
2812 struct ext4_free_data *entry;
2813 ext4_fsblk_t discard_block;
2814 struct list_head *l, *ltmp;
2816 list_for_each_safe(l, ltmp, &txn->t_private_list) {
2817 entry = list_entry(l, struct ext4_free_data, list);
2819 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2820 entry->count, entry->group, entry);
2822 err = ext4_mb_load_buddy(sb, entry->group, &e4b);
2823 /* we expect to find existing buddy because it's pinned */
2827 /* there are blocks to put in buddy to make them really free */
2828 count += entry->count;
2830 ext4_lock_group(sb, entry->group);
2831 /* Take it out of per group rb tree */
2832 rb_erase(&entry->node, &(db->bb_free_root));
2833 mb_free_blocks(NULL, &e4b, entry->start_blk, entry->count);
2835 if (!db->bb_free_root.rb_node) {
2836 /* No more items in the per group rb tree
2837 * balance refcounts from ext4_mb_free_metadata()
2839 page_cache_release(e4b.bd_buddy_page);
2840 page_cache_release(e4b.bd_bitmap_page);
2842 ext4_unlock_group(sb, entry->group);
2843 discard_block = (ext4_fsblk_t) entry->group * EXT4_BLOCKS_PER_GROUP(sb)
2845 + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2846 trace_ext4_discard_blocks(sb, (unsigned long long)discard_block,
2848 sb_issue_discard(sb, discard_block, entry->count);
2850 kmem_cache_free(ext4_free_ext_cachep, entry);
2851 ext4_mb_release_desc(&e4b);
2854 mb_debug(1, "freed %u blocks in %u structures\n", count, count2);
2857 #ifdef CONFIG_EXT4_DEBUG
2858 u8 mb_enable_debug __read_mostly;
2860 static struct dentry *debugfs_dir;
2861 static struct dentry *debugfs_debug;
2863 static void __init ext4_create_debugfs_entry(void)
2865 debugfs_dir = debugfs_create_dir("ext4", NULL);
2867 debugfs_debug = debugfs_create_u8("mballoc-debug",
2873 static void ext4_remove_debugfs_entry(void)
2875 debugfs_remove(debugfs_debug);
2876 debugfs_remove(debugfs_dir);
2881 static void __init ext4_create_debugfs_entry(void)
2885 static void ext4_remove_debugfs_entry(void)
2891 int __init init_ext4_mballoc(void)
2893 ext4_pspace_cachep =
2894 kmem_cache_create("ext4_prealloc_space",
2895 sizeof(struct ext4_prealloc_space),
2896 0, SLAB_RECLAIM_ACCOUNT, NULL);
2897 if (ext4_pspace_cachep == NULL)
2901 kmem_cache_create("ext4_alloc_context",
2902 sizeof(struct ext4_allocation_context),
2903 0, SLAB_RECLAIM_ACCOUNT, NULL);
2904 if (ext4_ac_cachep == NULL) {
2905 kmem_cache_destroy(ext4_pspace_cachep);
2909 ext4_free_ext_cachep =
2910 kmem_cache_create("ext4_free_block_extents",
2911 sizeof(struct ext4_free_data),
2912 0, SLAB_RECLAIM_ACCOUNT, NULL);
2913 if (ext4_free_ext_cachep == NULL) {
2914 kmem_cache_destroy(ext4_pspace_cachep);
2915 kmem_cache_destroy(ext4_ac_cachep);
2918 ext4_create_debugfs_entry();
2922 void exit_ext4_mballoc(void)
2925 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2926 * before destroying the slab cache.
2929 kmem_cache_destroy(ext4_pspace_cachep);
2930 kmem_cache_destroy(ext4_ac_cachep);
2931 kmem_cache_destroy(ext4_free_ext_cachep);
2932 ext4_remove_debugfs_entry();
2937 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
2938 * Returns 0 if success or error code
2940 static noinline_for_stack int
2941 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
2942 handle_t *handle, unsigned int reserv_blks)
2944 struct buffer_head *bitmap_bh = NULL;
2945 struct ext4_super_block *es;
2946 struct ext4_group_desc *gdp;
2947 struct buffer_head *gdp_bh;
2948 struct ext4_sb_info *sbi;
2949 struct super_block *sb;
2953 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
2954 BUG_ON(ac->ac_b_ex.fe_len <= 0);
2962 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
2966 err = ext4_journal_get_write_access(handle, bitmap_bh);
2971 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
2975 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
2976 ext4_free_blks_count(sb, gdp));
2978 err = ext4_journal_get_write_access(handle, gdp_bh);
2982 block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb)
2983 + ac->ac_b_ex.fe_start
2984 + le32_to_cpu(es->s_first_data_block);
2986 len = ac->ac_b_ex.fe_len;
2987 if (!ext4_data_block_valid(sbi, block, len)) {
2988 ext4_error(sb, __func__,
2989 "Allocating blocks %llu-%llu which overlap "
2990 "fs metadata\n", block, block+len);
2991 /* File system mounted not to panic on error
2992 * Fix the bitmap and repeat the block allocation
2993 * We leak some of the blocks here.
2995 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
2996 mb_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
2997 ac->ac_b_ex.fe_len);
2998 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
2999 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3005 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3006 #ifdef AGGRESSIVE_CHECK
3009 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3010 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3011 bitmap_bh->b_data));
3015 mb_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,ac->ac_b_ex.fe_len);
3016 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
3017 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3018 ext4_free_blks_set(sb, gdp,
3019 ext4_free_blocks_after_init(sb,
3020 ac->ac_b_ex.fe_group, gdp));
3022 len = ext4_free_blks_count(sb, gdp) - ac->ac_b_ex.fe_len;
3023 ext4_free_blks_set(sb, gdp, len);
3024 gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
3026 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3027 percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
3029 * Now reduce the dirty block count also. Should not go negative
3031 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
3032 /* release all the reserved blocks if non delalloc */
3033 percpu_counter_sub(&sbi->s_dirtyblocks_counter, reserv_blks);
3035 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
3036 ac->ac_b_ex.fe_len);
3037 /* convert reserved quota blocks to real quota blocks */
3038 vfs_dq_claim_block(ac->ac_inode, ac->ac_b_ex.fe_len);
3041 if (sbi->s_log_groups_per_flex) {
3042 ext4_group_t flex_group = ext4_flex_group(sbi,
3043 ac->ac_b_ex.fe_group);
3044 atomic_sub(ac->ac_b_ex.fe_len,
3045 &sbi->s_flex_groups[flex_group].free_blocks);
3048 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3051 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
3060 * here we normalize request for locality group
3061 * Group request are normalized to s_strip size if we set the same via mount
3062 * option. If not we set it to s_mb_group_prealloc which can be configured via
3063 * /sys/fs/ext4/<partition>/mb_group_prealloc
3065 * XXX: should we try to preallocate more than the group has now?
3067 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3069 struct super_block *sb = ac->ac_sb;
3070 struct ext4_locality_group *lg = ac->ac_lg;
3073 if (EXT4_SB(sb)->s_stripe)
3074 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe;
3076 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3077 mb_debug(1, "#%u: goal %u blocks for locality group\n",
3078 current->pid, ac->ac_g_ex.fe_len);
3082 * Normalization means making request better in terms of
3083 * size and alignment
3085 static noinline_for_stack void
3086 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
3087 struct ext4_allocation_request *ar)
3091 loff_t size, orig_size, start_off;
3092 ext4_lblk_t start, orig_start;
3093 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3094 struct ext4_prealloc_space *pa;
3096 /* do normalize only data requests, metadata requests
3097 do not need preallocation */
3098 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3101 /* sometime caller may want exact blocks */
3102 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3105 /* caller may indicate that preallocation isn't
3106 * required (it's a tail, for example) */
3107 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3110 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3111 ext4_mb_normalize_group_request(ac);
3115 bsbits = ac->ac_sb->s_blocksize_bits;
3117 /* first, let's learn actual file size
3118 * given current request is allocated */
3119 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
3120 size = size << bsbits;
3121 if (size < i_size_read(ac->ac_inode))
3122 size = i_size_read(ac->ac_inode);
3124 /* max size of free chunks */
3127 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3128 (req <= (size) || max <= (chunk_size))
3130 /* first, try to predict filesize */
3131 /* XXX: should this table be tunable? */
3133 if (size <= 16 * 1024) {
3135 } else if (size <= 32 * 1024) {
3137 } else if (size <= 64 * 1024) {
3139 } else if (size <= 128 * 1024) {
3141 } else if (size <= 256 * 1024) {
3143 } else if (size <= 512 * 1024) {
3145 } else if (size <= 1024 * 1024) {
3147 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
3148 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3149 (21 - bsbits)) << 21;
3150 size = 2 * 1024 * 1024;
3151 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
3152 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3153 (22 - bsbits)) << 22;
3154 size = 4 * 1024 * 1024;
3155 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3156 (8<<20)>>bsbits, max, 8 * 1024)) {
3157 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3158 (23 - bsbits)) << 23;
3159 size = 8 * 1024 * 1024;
3161 start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
3162 size = ac->ac_o_ex.fe_len << bsbits;
3164 orig_size = size = size >> bsbits;
3165 orig_start = start = start_off >> bsbits;
3167 /* don't cover already allocated blocks in selected range */
3168 if (ar->pleft && start <= ar->lleft) {
3169 size -= ar->lleft + 1 - start;
3170 start = ar->lleft + 1;
3172 if (ar->pright && start + size - 1 >= ar->lright)
3173 size -= start + size - ar->lright;
3177 /* check we don't cross already preallocated blocks */
3179 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3184 spin_lock(&pa->pa_lock);
3185 if (pa->pa_deleted) {
3186 spin_unlock(&pa->pa_lock);
3190 pa_end = pa->pa_lstart + pa->pa_len;
3192 /* PA must not overlap original request */
3193 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3194 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3196 /* skip PA normalized request doesn't overlap with */
3197 if (pa->pa_lstart >= end) {
3198 spin_unlock(&pa->pa_lock);
3201 if (pa_end <= start) {
3202 spin_unlock(&pa->pa_lock);
3205 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3207 if (pa_end <= ac->ac_o_ex.fe_logical) {
3208 BUG_ON(pa_end < start);
3212 if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3213 BUG_ON(pa->pa_lstart > end);
3214 end = pa->pa_lstart;
3216 spin_unlock(&pa->pa_lock);
3221 /* XXX: extra loop to check we really don't overlap preallocations */
3223 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3225 spin_lock(&pa->pa_lock);
3226 if (pa->pa_deleted == 0) {
3227 pa_end = pa->pa_lstart + pa->pa_len;
3228 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3230 spin_unlock(&pa->pa_lock);
3234 if (start + size <= ac->ac_o_ex.fe_logical &&
3235 start > ac->ac_o_ex.fe_logical) {
3236 printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n",
3237 (unsigned long) start, (unsigned long) size,
3238 (unsigned long) ac->ac_o_ex.fe_logical);
3240 BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
3241 start > ac->ac_o_ex.fe_logical);
3242 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3244 /* now prepare goal request */
3246 /* XXX: is it better to align blocks WRT to logical
3247 * placement or satisfy big request as is */
3248 ac->ac_g_ex.fe_logical = start;
3249 ac->ac_g_ex.fe_len = size;
3251 /* define goal start in order to merge */
3252 if (ar->pright && (ar->lright == (start + size))) {
3253 /* merge to the right */
3254 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3255 &ac->ac_f_ex.fe_group,
3256 &ac->ac_f_ex.fe_start);
3257 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3259 if (ar->pleft && (ar->lleft + 1 == start)) {
3260 /* merge to the left */
3261 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3262 &ac->ac_f_ex.fe_group,
3263 &ac->ac_f_ex.fe_start);
3264 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3267 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size,
3268 (unsigned) orig_size, (unsigned) start);
3271 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3273 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3275 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3276 atomic_inc(&sbi->s_bal_reqs);
3277 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3278 if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
3279 atomic_inc(&sbi->s_bal_success);
3280 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3281 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3282 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3283 atomic_inc(&sbi->s_bal_goals);
3284 if (ac->ac_found > sbi->s_mb_max_to_scan)
3285 atomic_inc(&sbi->s_bal_breaks);
3288 ext4_mb_store_history(ac);
3292 * use blocks preallocated to inode
3294 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3295 struct ext4_prealloc_space *pa)
3301 /* found preallocated blocks, use them */
3302 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3303 end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len);
3305 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3306 &ac->ac_b_ex.fe_start);
3307 ac->ac_b_ex.fe_len = len;
3308 ac->ac_status = AC_STATUS_FOUND;
3311 BUG_ON(start < pa->pa_pstart);
3312 BUG_ON(start + len > pa->pa_pstart + pa->pa_len);
3313 BUG_ON(pa->pa_free < len);
3316 mb_debug(1, "use %llu/%u from inode pa %p\n", start, len, pa);
3320 * use blocks preallocated to locality group
3322 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3323 struct ext4_prealloc_space *pa)
3325 unsigned int len = ac->ac_o_ex.fe_len;
3327 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3328 &ac->ac_b_ex.fe_group,
3329 &ac->ac_b_ex.fe_start);
3330 ac->ac_b_ex.fe_len = len;
3331 ac->ac_status = AC_STATUS_FOUND;
3334 /* we don't correct pa_pstart or pa_plen here to avoid
3335 * possible race when the group is being loaded concurrently
3336 * instead we correct pa later, after blocks are marked
3337 * in on-disk bitmap -- see ext4_mb_release_context()
3338 * Other CPUs are prevented from allocating from this pa by lg_mutex
3340 mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3344 * Return the prealloc space that have minimal distance
3345 * from the goal block. @cpa is the prealloc
3346 * space that is having currently known minimal distance
3347 * from the goal block.
3349 static struct ext4_prealloc_space *
3350 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
3351 struct ext4_prealloc_space *pa,
3352 struct ext4_prealloc_space *cpa)
3354 ext4_fsblk_t cur_distance, new_distance;
3357 atomic_inc(&pa->pa_count);
3360 cur_distance = abs(goal_block - cpa->pa_pstart);
3361 new_distance = abs(goal_block - pa->pa_pstart);
3363 if (cur_distance < new_distance)
3366 /* drop the previous reference */
3367 atomic_dec(&cpa->pa_count);
3368 atomic_inc(&pa->pa_count);
3373 * search goal blocks in preallocated space
3375 static noinline_for_stack int
3376 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
3379 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3380 struct ext4_locality_group *lg;
3381 struct ext4_prealloc_space *pa, *cpa = NULL;
3382 ext4_fsblk_t goal_block;
3384 /* only data can be preallocated */
3385 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3388 /* first, try per-file preallocation */
3390 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3392 /* all fields in this condition don't change,
3393 * so we can skip locking for them */
3394 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3395 ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len)
3398 /* found preallocated blocks, use them */
3399 spin_lock(&pa->pa_lock);
3400 if (pa->pa_deleted == 0 && pa->pa_free) {
3401 atomic_inc(&pa->pa_count);
3402 ext4_mb_use_inode_pa(ac, pa);
3403 spin_unlock(&pa->pa_lock);
3404 ac->ac_criteria = 10;
3408 spin_unlock(&pa->pa_lock);
3412 /* can we use group allocation? */
3413 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3416 /* inode may have no locality group for some reason */
3420 order = fls(ac->ac_o_ex.fe_len) - 1;
3421 if (order > PREALLOC_TB_SIZE - 1)
3422 /* The max size of hash table is PREALLOC_TB_SIZE */
3423 order = PREALLOC_TB_SIZE - 1;
3425 goal_block = ac->ac_g_ex.fe_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb) +
3426 ac->ac_g_ex.fe_start +
3427 le32_to_cpu(EXT4_SB(ac->ac_sb)->s_es->s_first_data_block);
3429 * search for the prealloc space that is having
3430 * minimal distance from the goal block.
3432 for (i = order; i < PREALLOC_TB_SIZE; i++) {
3434 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
3436 spin_lock(&pa->pa_lock);
3437 if (pa->pa_deleted == 0 &&
3438 pa->pa_free >= ac->ac_o_ex.fe_len) {
3440 cpa = ext4_mb_check_group_pa(goal_block,
3443 spin_unlock(&pa->pa_lock);
3448 ext4_mb_use_group_pa(ac, cpa);
3449 ac->ac_criteria = 20;
3456 * the function goes through all block freed in the group
3457 * but not yet committed and marks them used in in-core bitmap.
3458 * buddy must be generated from this bitmap
3459 * Need to be called with the ext4 group lock held
3461 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
3465 struct ext4_group_info *grp;
3466 struct ext4_free_data *entry;
3468 grp = ext4_get_group_info(sb, group);
3469 n = rb_first(&(grp->bb_free_root));
3472 entry = rb_entry(n, struct ext4_free_data, node);
3473 mb_set_bits(bitmap, entry->start_blk, entry->count);
3480 * the function goes through all preallocation in this group and marks them
3481 * used in in-core bitmap. buddy must be generated from this bitmap
3482 * Need to be called with ext4 group lock held
3484 static noinline_for_stack
3485 void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3488 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3489 struct ext4_prealloc_space *pa;
3490 struct list_head *cur;
3491 ext4_group_t groupnr;
3492 ext4_grpblk_t start;
3493 int preallocated = 0;
3497 /* all form of preallocation discards first load group,
3498 * so the only competing code is preallocation use.
3499 * we don't need any locking here
3500 * notice we do NOT ignore preallocations with pa_deleted
3501 * otherwise we could leave used blocks available for
3502 * allocation in buddy when concurrent ext4_mb_put_pa()
3503 * is dropping preallocation
3505 list_for_each(cur, &grp->bb_prealloc_list) {
3506 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3507 spin_lock(&pa->pa_lock);
3508 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3511 spin_unlock(&pa->pa_lock);
3512 if (unlikely(len == 0))
3514 BUG_ON(groupnr != group);
3515 mb_set_bits(bitmap, start, len);
3516 preallocated += len;
3519 mb_debug(1, "prellocated %u for group %u\n", preallocated, group);
3522 static void ext4_mb_pa_callback(struct rcu_head *head)
3524 struct ext4_prealloc_space *pa;
3525 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3526 kmem_cache_free(ext4_pspace_cachep, pa);
3530 * drops a reference to preallocated space descriptor
3531 * if this was the last reference and the space is consumed
3533 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3534 struct super_block *sb, struct ext4_prealloc_space *pa)
3537 ext4_fsblk_t grp_blk;
3539 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0)
3542 /* in this short window concurrent discard can set pa_deleted */
3543 spin_lock(&pa->pa_lock);
3544 if (pa->pa_deleted == 1) {
3545 spin_unlock(&pa->pa_lock);
3550 spin_unlock(&pa->pa_lock);
3552 grp_blk = pa->pa_pstart;
3554 * If doing group-based preallocation, pa_pstart may be in the
3555 * next group when pa is used up
3557 if (pa->pa_type == MB_GROUP_PA)
3560 ext4_get_group_no_and_offset(sb, grp_blk, &grp, NULL);
3565 * P1 (buddy init) P2 (regular allocation)
3566 * find block B in PA
3567 * copy on-disk bitmap to buddy
3568 * mark B in on-disk bitmap
3569 * drop PA from group
3570 * mark all PAs in buddy
3572 * thus, P1 initializes buddy with B available. to prevent this
3573 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3576 ext4_lock_group(sb, grp);
3577 list_del(&pa->pa_group_list);
3578 ext4_unlock_group(sb, grp);
3580 spin_lock(pa->pa_obj_lock);
3581 list_del_rcu(&pa->pa_inode_list);
3582 spin_unlock(pa->pa_obj_lock);
3584 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3588 * creates new preallocated space for given inode
3590 static noinline_for_stack int
3591 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
3593 struct super_block *sb = ac->ac_sb;
3594 struct ext4_prealloc_space *pa;
3595 struct ext4_group_info *grp;
3596 struct ext4_inode_info *ei;
3598 /* preallocate only when found space is larger then requested */
3599 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3600 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3601 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3603 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3607 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3613 /* we can't allocate as much as normalizer wants.
3614 * so, found space must get proper lstart
3615 * to cover original request */
3616 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3617 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3619 /* we're limited by original request in that
3620 * logical block must be covered any way
3621 * winl is window we can move our chunk within */
3622 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
3624 /* also, we should cover whole original request */
3625 wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len;
3627 /* the smallest one defines real window */
3628 win = min(winl, wins);
3630 offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len;
3631 if (offs && offs < win)
3634 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win;
3635 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3636 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3639 /* preallocation can change ac_b_ex, thus we store actually
3640 * allocated blocks for history */
3641 ac->ac_f_ex = ac->ac_b_ex;
3643 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3644 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3645 pa->pa_len = ac->ac_b_ex.fe_len;
3646 pa->pa_free = pa->pa_len;
3647 atomic_set(&pa->pa_count, 1);
3648 spin_lock_init(&pa->pa_lock);
3649 INIT_LIST_HEAD(&pa->pa_inode_list);
3650 INIT_LIST_HEAD(&pa->pa_group_list);
3652 pa->pa_type = MB_INODE_PA;
3654 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa,
3655 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3656 trace_ext4_mb_new_inode_pa(ac, pa);
3658 ext4_mb_use_inode_pa(ac, pa);
3659 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3661 ei = EXT4_I(ac->ac_inode);
3662 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3664 pa->pa_obj_lock = &ei->i_prealloc_lock;
3665 pa->pa_inode = ac->ac_inode;
3667 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3668 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3669 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3671 spin_lock(pa->pa_obj_lock);
3672 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3673 spin_unlock(pa->pa_obj_lock);
3679 * creates new preallocated space for locality group inodes belongs to
3681 static noinline_for_stack int
3682 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
3684 struct super_block *sb = ac->ac_sb;
3685 struct ext4_locality_group *lg;
3686 struct ext4_prealloc_space *pa;
3687 struct ext4_group_info *grp;
3689 /* preallocate only when found space is larger then requested */
3690 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3691 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3692 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3694 BUG_ON(ext4_pspace_cachep == NULL);
3695 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3699 /* preallocation can change ac_b_ex, thus we store actually
3700 * allocated blocks for history */
3701 ac->ac_f_ex = ac->ac_b_ex;
3703 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3704 pa->pa_lstart = pa->pa_pstart;
3705 pa->pa_len = ac->ac_b_ex.fe_len;
3706 pa->pa_free = pa->pa_len;
3707 atomic_set(&pa->pa_count, 1);
3708 spin_lock_init(&pa->pa_lock);
3709 INIT_LIST_HEAD(&pa->pa_inode_list);
3710 INIT_LIST_HEAD(&pa->pa_group_list);
3712 pa->pa_type = MB_GROUP_PA;
3714 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa,
3715 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3716 trace_ext4_mb_new_group_pa(ac, pa);
3718 ext4_mb_use_group_pa(ac, pa);
3719 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3721 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3725 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3726 pa->pa_inode = NULL;
3728 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3729 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3730 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3733 * We will later add the new pa to the right bucket
3734 * after updating the pa_free in ext4_mb_release_context
3739 static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3743 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3744 err = ext4_mb_new_group_pa(ac);
3746 err = ext4_mb_new_inode_pa(ac);
3751 * finds all unused blocks in on-disk bitmap, frees them in
3752 * in-core bitmap and buddy.
3753 * @pa must be unlinked from inode and group lists, so that
3754 * nobody else can find/use it.
3755 * the caller MUST hold group/inode locks.
3756 * TODO: optimize the case when there are no in-core structures yet
3758 static noinline_for_stack int
3759 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
3760 struct ext4_prealloc_space *pa,
3761 struct ext4_allocation_context *ac)
3763 struct super_block *sb = e4b->bd_sb;
3764 struct ext4_sb_info *sbi = EXT4_SB(sb);
3769 unsigned long long grp_blk_start;
3774 BUG_ON(pa->pa_deleted == 0);
3775 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3776 grp_blk_start = pa->pa_pstart - bit;
3777 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3778 end = bit + pa->pa_len;
3782 ac->ac_inode = pa->pa_inode;
3783 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
3787 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
3790 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
3791 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
3792 le32_to_cpu(sbi->s_es->s_first_data_block);
3793 mb_debug(1, " free preallocated %u/%u in group %u\n",
3794 (unsigned) start, (unsigned) next - bit,
3799 ac->ac_b_ex.fe_group = group;
3800 ac->ac_b_ex.fe_start = bit;
3801 ac->ac_b_ex.fe_len = next - bit;
3802 ac->ac_b_ex.fe_logical = 0;
3803 ext4_mb_store_history(ac);
3806 trace_ext4_mb_release_inode_pa(ac, pa, grp_blk_start + bit,
3808 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3811 if (free != pa->pa_free) {
3812 printk(KERN_CRIT "pa %p: logic %lu, phys. %lu, len %lu\n",
3813 pa, (unsigned long) pa->pa_lstart,
3814 (unsigned long) pa->pa_pstart,
3815 (unsigned long) pa->pa_len);
3816 ext4_grp_locked_error(sb, group,
3817 __func__, "free %u, pa_free %u",
3820 * pa is already deleted so we use the value obtained
3821 * from the bitmap and continue.
3824 atomic_add(free, &sbi->s_mb_discarded);
3829 static noinline_for_stack int
3830 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
3831 struct ext4_prealloc_space *pa,
3832 struct ext4_allocation_context *ac)
3834 struct super_block *sb = e4b->bd_sb;
3839 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
3841 trace_ext4_mb_release_group_pa(ac, pa);
3842 BUG_ON(pa->pa_deleted == 0);
3843 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3844 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3845 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3846 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3850 ac->ac_inode = NULL;
3851 ac->ac_b_ex.fe_group = group;
3852 ac->ac_b_ex.fe_start = bit;
3853 ac->ac_b_ex.fe_len = pa->pa_len;
3854 ac->ac_b_ex.fe_logical = 0;
3855 ext4_mb_store_history(ac);
3862 * releases all preallocations in given group
3864 * first, we need to decide discard policy:
3865 * - when do we discard
3867 * - how many do we discard
3868 * 1) how many requested
3870 static noinline_for_stack int
3871 ext4_mb_discard_group_preallocations(struct super_block *sb,
3872 ext4_group_t group, int needed)
3874 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3875 struct buffer_head *bitmap_bh = NULL;
3876 struct ext4_prealloc_space *pa, *tmp;
3877 struct ext4_allocation_context *ac;
3878 struct list_head list;
3879 struct ext4_buddy e4b;
3884 mb_debug(1, "discard preallocation for group %u\n", group);
3886 if (list_empty(&grp->bb_prealloc_list))
3889 bitmap_bh = ext4_read_block_bitmap(sb, group);
3890 if (bitmap_bh == NULL) {
3891 ext4_error(sb, __func__, "Error in reading block "
3892 "bitmap for %u", group);
3896 err = ext4_mb_load_buddy(sb, group, &e4b);
3898 ext4_error(sb, __func__, "Error in loading buddy "
3899 "information for %u", group);
3905 needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
3907 INIT_LIST_HEAD(&list);
3908 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
3912 ext4_lock_group(sb, group);
3913 list_for_each_entry_safe(pa, tmp,
3914 &grp->bb_prealloc_list, pa_group_list) {
3915 spin_lock(&pa->pa_lock);
3916 if (atomic_read(&pa->pa_count)) {
3917 spin_unlock(&pa->pa_lock);
3921 if (pa->pa_deleted) {
3922 spin_unlock(&pa->pa_lock);
3926 /* seems this one can be freed ... */
3929 /* we can trust pa_free ... */
3930 free += pa->pa_free;
3932 spin_unlock(&pa->pa_lock);
3934 list_del(&pa->pa_group_list);
3935 list_add(&pa->u.pa_tmp_list, &list);
3938 /* if we still need more blocks and some PAs were used, try again */
3939 if (free < needed && busy) {
3941 ext4_unlock_group(sb, group);
3943 * Yield the CPU here so that we don't get soft lockup
3944 * in non preempt case.
3950 /* found anything to free? */
3951 if (list_empty(&list)) {
3956 /* now free all selected PAs */
3957 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3959 /* remove from object (inode or locality group) */
3960 spin_lock(pa->pa_obj_lock);
3961 list_del_rcu(&pa->pa_inode_list);
3962 spin_unlock(pa->pa_obj_lock);
3964 if (pa->pa_type == MB_GROUP_PA)
3965 ext4_mb_release_group_pa(&e4b, pa, ac);
3967 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);
3969 list_del(&pa->u.pa_tmp_list);
3970 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3974 ext4_unlock_group(sb, group);
3976 kmem_cache_free(ext4_ac_cachep, ac);
3977 ext4_mb_release_desc(&e4b);
3983 * releases all non-used preallocated blocks for given inode
3985 * It's important to discard preallocations under i_data_sem
3986 * We don't want another block to be served from the prealloc
3987 * space when we are discarding the inode prealloc space.
3989 * FIXME!! Make sure it is valid at all the call sites
3991 void ext4_discard_preallocations(struct inode *inode)
3993 struct ext4_inode_info *ei = EXT4_I(inode);
3994 struct super_block *sb = inode->i_sb;
3995 struct buffer_head *bitmap_bh = NULL;
3996 struct ext4_prealloc_space *pa, *tmp;
3997 struct ext4_allocation_context *ac;
3998 ext4_group_t group = 0;
3999 struct list_head list;
4000 struct ext4_buddy e4b;
4003 if (!S_ISREG(inode->i_mode)) {
4004 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
4008 mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino);
4009 trace_ext4_discard_preallocations(inode);
4011 INIT_LIST_HEAD(&list);
4013 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4016 ac->ac_inode = inode;
4019 /* first, collect all pa's in the inode */
4020 spin_lock(&ei->i_prealloc_lock);
4021 while (!list_empty(&ei->i_prealloc_list)) {
4022 pa = list_entry(ei->i_prealloc_list.next,
4023 struct ext4_prealloc_space, pa_inode_list);
4024 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
4025 spin_lock(&pa->pa_lock);
4026 if (atomic_read(&pa->pa_count)) {
4027 /* this shouldn't happen often - nobody should
4028 * use preallocation while we're discarding it */
4029 spin_unlock(&pa->pa_lock);
4030 spin_unlock(&ei->i_prealloc_lock);
4031 printk(KERN_ERR "uh-oh! used pa while discarding\n");
4033 schedule_timeout_uninterruptible(HZ);
4037 if (pa->pa_deleted == 0) {
4039 spin_unlock(&pa->pa_lock);
4040 list_del_rcu(&pa->pa_inode_list);
4041 list_add(&pa->u.pa_tmp_list, &list);
4045 /* someone is deleting pa right now */
4046 spin_unlock(&pa->pa_lock);
4047 spin_unlock(&ei->i_prealloc_lock);
4049 /* we have to wait here because pa_deleted
4050 * doesn't mean pa is already unlinked from
4051 * the list. as we might be called from
4052 * ->clear_inode() the inode will get freed
4053 * and concurrent thread which is unlinking
4054 * pa from inode's list may access already
4055 * freed memory, bad-bad-bad */
4057 /* XXX: if this happens too often, we can
4058 * add a flag to force wait only in case
4059 * of ->clear_inode(), but not in case of
4060 * regular truncate */
4061 schedule_timeout_uninterruptible(HZ);
4064 spin_unlock(&ei->i_prealloc_lock);
4066 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4067 BUG_ON(pa->pa_type != MB_INODE_PA);
4068 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
4070 err = ext4_mb_load_buddy(sb, group, &e4b);
4072 ext4_error(sb, __func__, "Error in loading buddy "
4073 "information for %u", group);
4077 bitmap_bh = ext4_read_block_bitmap(sb, group);
4078 if (bitmap_bh == NULL) {
4079 ext4_error(sb, __func__, "Error in reading block "
4080 "bitmap for %u", group);
4081 ext4_mb_release_desc(&e4b);
4085 ext4_lock_group(sb, group);
4086 list_del(&pa->pa_group_list);
4087 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);
4088 ext4_unlock_group(sb, group);
4090 ext4_mb_release_desc(&e4b);
4093 list_del(&pa->u.pa_tmp_list);
4094 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4097 kmem_cache_free(ext4_ac_cachep, ac);
4101 * finds all preallocated spaces and return blocks being freed to them
4102 * if preallocated space becomes full (no block is used from the space)
4103 * then the function frees space in buddy
4104 * XXX: at the moment, truncate (which is the only way to free blocks)
4105 * discards all preallocations
4107 static void ext4_mb_return_to_preallocation(struct inode *inode,
4108 struct ext4_buddy *e4b,
4109 sector_t block, int count)
4111 BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list));
4113 #ifdef CONFIG_EXT4_DEBUG
4114 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4116 struct super_block *sb = ac->ac_sb;
4117 ext4_group_t ngroups, i;
4119 printk(KERN_ERR "EXT4-fs: Can't allocate:"
4120 " Allocation context details:\n");
4121 printk(KERN_ERR "EXT4-fs: status %d flags %d\n",
4122 ac->ac_status, ac->ac_flags);
4123 printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
4124 "best %lu/%lu/%lu@%lu cr %d\n",
4125 (unsigned long)ac->ac_o_ex.fe_group,
4126 (unsigned long)ac->ac_o_ex.fe_start,
4127 (unsigned long)ac->ac_o_ex.fe_len,
4128 (unsigned long)ac->ac_o_ex.fe_logical,
4129 (unsigned long)ac->ac_g_ex.fe_group,
4130 (unsigned long)ac->ac_g_ex.fe_start,
4131 (unsigned long)ac->ac_g_ex.fe_len,
4132 (unsigned long)ac->ac_g_ex.fe_logical,
4133 (unsigned long)ac->ac_b_ex.fe_group,
4134 (unsigned long)ac->ac_b_ex.fe_start,
4135 (unsigned long)ac->ac_b_ex.fe_len,
4136 (unsigned long)ac->ac_b_ex.fe_logical,
4137 (int)ac->ac_criteria);
4138 printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
4140 printk(KERN_ERR "EXT4-fs: groups: \n");
4141 ngroups = ext4_get_groups_count(sb);
4142 for (i = 0; i < ngroups; i++) {
4143 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4144 struct ext4_prealloc_space *pa;
4145 ext4_grpblk_t start;
4146 struct list_head *cur;
4147 ext4_lock_group(sb, i);
4148 list_for_each(cur, &grp->bb_prealloc_list) {
4149 pa = list_entry(cur, struct ext4_prealloc_space,
4151 spin_lock(&pa->pa_lock);
4152 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4154 spin_unlock(&pa->pa_lock);
4155 printk(KERN_ERR "PA:%u:%d:%u \n", i,
4158 ext4_unlock_group(sb, i);
4160 if (grp->bb_free == 0)
4162 printk(KERN_ERR "%u: %d/%d \n",
4163 i, grp->bb_free, grp->bb_fragments);
4165 printk(KERN_ERR "\n");
4168 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4175 * We use locality group preallocation for small size file. The size of the
4176 * file is determined by the current size or the resulting size after
4177 * allocation which ever is larger
4179 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4181 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4183 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4184 int bsbits = ac->ac_sb->s_blocksize_bits;
4187 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4190 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4193 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
4194 isize = i_size_read(ac->ac_inode) >> bsbits;
4195 size = max(size, isize);
4197 /* don't use group allocation for large files */
4198 if (size >= sbi->s_mb_stream_request) {
4199 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4203 BUG_ON(ac->ac_lg != NULL);
4205 * locality group prealloc space are per cpu. The reason for having
4206 * per cpu locality group is to reduce the contention between block
4207 * request from multiple CPUs.
4209 ac->ac_lg = per_cpu_ptr(sbi->s_locality_groups, raw_smp_processor_id());
4211 /* we're going to use group allocation */
4212 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4214 /* serialize all allocations in the group */
4215 mutex_lock(&ac->ac_lg->lg_mutex);
4218 static noinline_for_stack int
4219 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
4220 struct ext4_allocation_request *ar)
4222 struct super_block *sb = ar->inode->i_sb;
4223 struct ext4_sb_info *sbi = EXT4_SB(sb);
4224 struct ext4_super_block *es = sbi->s_es;
4228 ext4_grpblk_t block;
4230 /* we can't allocate > group size */
4233 /* just a dirty hack to filter too big requests */
4234 if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10)
4235 len = EXT4_BLOCKS_PER_GROUP(sb) - 10;
4237 /* start searching from the goal */
4239 if (goal < le32_to_cpu(es->s_first_data_block) ||
4240 goal >= ext4_blocks_count(es))
4241 goal = le32_to_cpu(es->s_first_data_block);
4242 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4244 /* set up allocation goals */
4245 memset(ac, 0, sizeof(struct ext4_allocation_context));
4246 ac->ac_b_ex.fe_logical = ar->logical;
4247 ac->ac_status = AC_STATUS_CONTINUE;
4249 ac->ac_inode = ar->inode;
4250 ac->ac_o_ex.fe_logical = ar->logical;
4251 ac->ac_o_ex.fe_group = group;
4252 ac->ac_o_ex.fe_start = block;
4253 ac->ac_o_ex.fe_len = len;
4254 ac->ac_g_ex.fe_logical = ar->logical;
4255 ac->ac_g_ex.fe_group = group;
4256 ac->ac_g_ex.fe_start = block;
4257 ac->ac_g_ex.fe_len = len;
4258 ac->ac_flags = ar->flags;
4260 /* we have to define context: we'll we work with a file or
4261 * locality group. this is a policy, actually */
4262 ext4_mb_group_or_file(ac);
4264 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4265 "left: %u/%u, right %u/%u to %swritable\n",
4266 (unsigned) ar->len, (unsigned) ar->logical,
4267 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4268 (unsigned) ar->lleft, (unsigned) ar->pleft,
4269 (unsigned) ar->lright, (unsigned) ar->pright,
4270 atomic_read(&ar->inode->i_writecount) ? "" : "non-");
4275 static noinline_for_stack void
4276 ext4_mb_discard_lg_preallocations(struct super_block *sb,
4277 struct ext4_locality_group *lg,
4278 int order, int total_entries)
4280 ext4_group_t group = 0;
4281 struct ext4_buddy e4b;
4282 struct list_head discard_list;
4283 struct ext4_prealloc_space *pa, *tmp;
4284 struct ext4_allocation_context *ac;
4286 mb_debug(1, "discard locality group preallocation\n");
4288 INIT_LIST_HEAD(&discard_list);
4289 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4293 spin_lock(&lg->lg_prealloc_lock);
4294 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
4296 spin_lock(&pa->pa_lock);
4297 if (atomic_read(&pa->pa_count)) {
4299 * This is the pa that we just used
4300 * for block allocation. So don't
4303 spin_unlock(&pa->pa_lock);
4306 if (pa->pa_deleted) {
4307 spin_unlock(&pa->pa_lock);
4310 /* only lg prealloc space */
4311 BUG_ON(pa->pa_type != MB_GROUP_PA);
4313 /* seems this one can be freed ... */
4315 spin_unlock(&pa->pa_lock);
4317 list_del_rcu(&pa->pa_inode_list);
4318 list_add(&pa->u.pa_tmp_list, &discard_list);
4321 if (total_entries <= 5) {
4323 * we want to keep only 5 entries
4324 * allowing it to grow to 8. This
4325 * mak sure we don't call discard
4326 * soon for this list.
4331 spin_unlock(&lg->lg_prealloc_lock);
4333 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
4335 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
4336 if (ext4_mb_load_buddy(sb, group, &e4b)) {
4337 ext4_error(sb, __func__, "Error in loading buddy "
4338 "information for %u", group);
4341 ext4_lock_group(sb, group);
4342 list_del(&pa->pa_group_list);
4343 ext4_mb_release_group_pa(&e4b, pa, ac);
4344 ext4_unlock_group(sb, group);
4346 ext4_mb_release_desc(&e4b);
4347 list_del(&pa->u.pa_tmp_list);
4348 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4351 kmem_cache_free(ext4_ac_cachep, ac);
4355 * We have incremented pa_count. So it cannot be freed at this
4356 * point. Also we hold lg_mutex. So no parallel allocation is
4357 * possible from this lg. That means pa_free cannot be updated.
4359 * A parallel ext4_mb_discard_group_preallocations is possible.
4360 * which can cause the lg_prealloc_list to be updated.
4363 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
4365 int order, added = 0, lg_prealloc_count = 1;
4366 struct super_block *sb = ac->ac_sb;
4367 struct ext4_locality_group *lg = ac->ac_lg;
4368 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
4370 order = fls(pa->pa_free) - 1;
4371 if (order > PREALLOC_TB_SIZE - 1)
4372 /* The max size of hash table is PREALLOC_TB_SIZE */
4373 order = PREALLOC_TB_SIZE - 1;
4374 /* Add the prealloc space to lg */
4376 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
4378 spin_lock(&tmp_pa->pa_lock);
4379 if (tmp_pa->pa_deleted) {
4380 spin_unlock(&tmp_pa->pa_lock);
4383 if (!added && pa->pa_free < tmp_pa->pa_free) {
4384 /* Add to the tail of the previous entry */
4385 list_add_tail_rcu(&pa->pa_inode_list,
4386 &tmp_pa->pa_inode_list);
4389 * we want to count the total
4390 * number of entries in the list
4393 spin_unlock(&tmp_pa->pa_lock);
4394 lg_prealloc_count++;
4397 list_add_tail_rcu(&pa->pa_inode_list,
4398 &lg->lg_prealloc_list[order]);
4401 /* Now trim the list to be not more than 8 elements */
4402 if (lg_prealloc_count > 8) {
4403 ext4_mb_discard_lg_preallocations(sb, lg,
4404 order, lg_prealloc_count);
4411 * release all resource we used in allocation
4413 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4415 struct ext4_prealloc_space *pa = ac->ac_pa;
4417 if (pa->pa_type == MB_GROUP_PA) {
4418 /* see comment in ext4_mb_use_group_pa() */
4419 spin_lock(&pa->pa_lock);
4420 pa->pa_pstart += ac->ac_b_ex.fe_len;
4421 pa->pa_lstart += ac->ac_b_ex.fe_len;
4422 pa->pa_free -= ac->ac_b_ex.fe_len;
4423 pa->pa_len -= ac->ac_b_ex.fe_len;
4424 spin_unlock(&pa->pa_lock);
4428 up_read(ac->alloc_semp);
4431 * We want to add the pa to the right bucket.
4432 * Remove it from the list and while adding
4433 * make sure the list to which we are adding
4434 * doesn't grow big. We need to release
4435 * alloc_semp before calling ext4_mb_add_n_trim()
4437 if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) {
4438 spin_lock(pa->pa_obj_lock);
4439 list_del_rcu(&pa->pa_inode_list);
4440 spin_unlock(pa->pa_obj_lock);
4441 ext4_mb_add_n_trim(ac);
4443 ext4_mb_put_pa(ac, ac->ac_sb, pa);
4445 if (ac->ac_bitmap_page)
4446 page_cache_release(ac->ac_bitmap_page);
4447 if (ac->ac_buddy_page)
4448 page_cache_release(ac->ac_buddy_page);
4449 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4450 mutex_unlock(&ac->ac_lg->lg_mutex);
4451 ext4_mb_collect_stats(ac);
4455 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4457 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4461 trace_ext4_mb_discard_preallocations(sb, needed);
4462 for (i = 0; i < ngroups && needed > 0; i++) {
4463 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4472 * Main entry point into mballoc to allocate blocks
4473 * it tries to use preallocation first, then falls back
4474 * to usual allocation
4476 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4477 struct ext4_allocation_request *ar, int *errp)
4480 struct ext4_allocation_context *ac = NULL;
4481 struct ext4_sb_info *sbi;
4482 struct super_block *sb;
4483 ext4_fsblk_t block = 0;
4484 unsigned int inquota = 0;
4485 unsigned int reserv_blks = 0;
4487 sb = ar->inode->i_sb;
4490 trace_ext4_request_blocks(ar);
4493 * For delayed allocation, we could skip the ENOSPC and
4494 * EDQUOT check, as blocks and quotas have been already
4495 * reserved when data being copied into pagecache.
4497 if (EXT4_I(ar->inode)->i_delalloc_reserved_flag)
4498 ar->flags |= EXT4_MB_DELALLOC_RESERVED;
4500 /* Without delayed allocation we need to verify
4501 * there is enough free blocks to do block allocation
4502 * and verify allocation doesn't exceed the quota limits.
4504 while (ar->len && ext4_claim_free_blocks(sbi, ar->len)) {
4505 /* let others to free the space */
4507 ar->len = ar->len >> 1;
4513 reserv_blks = ar->len;
4514 while (ar->len && vfs_dq_alloc_block(ar->inode, ar->len)) {
4515 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4525 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4532 *errp = ext4_mb_initialize_context(ac, ar);
4538 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4539 if (!ext4_mb_use_preallocated(ac)) {
4540 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4541 ext4_mb_normalize_request(ac, ar);
4543 /* allocate space in core */
4544 ext4_mb_regular_allocator(ac);
4546 /* as we've just preallocated more space than
4547 * user requested orinally, we store allocated
4548 * space in a special descriptor */
4549 if (ac->ac_status == AC_STATUS_FOUND &&
4550 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4551 ext4_mb_new_preallocation(ac);
4553 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
4554 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_blks);
4555 if (*errp == -EAGAIN) {
4557 * drop the reference that we took
4558 * in ext4_mb_use_best_found
4560 ext4_mb_release_context(ac);
4561 ac->ac_b_ex.fe_group = 0;
4562 ac->ac_b_ex.fe_start = 0;
4563 ac->ac_b_ex.fe_len = 0;
4564 ac->ac_status = AC_STATUS_CONTINUE;
4567 ac->ac_b_ex.fe_len = 0;
4569 ext4_mb_show_ac(ac);
4571 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4572 ar->len = ac->ac_b_ex.fe_len;
4575 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
4579 ac->ac_b_ex.fe_len = 0;
4581 ext4_mb_show_ac(ac);
4584 ext4_mb_release_context(ac);
4587 kmem_cache_free(ext4_ac_cachep, ac);
4589 if (inquota && ar->len < inquota)
4590 vfs_dq_free_block(ar->inode, inquota - ar->len);
4593 if (!EXT4_I(ar->inode)->i_delalloc_reserved_flag)
4594 /* release all the reserved blocks if non delalloc */
4595 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
4599 trace_ext4_allocate_blocks(ar, (unsigned long long)block);
4605 * We can merge two free data extents only if the physical blocks
4606 * are contiguous, AND the extents were freed by the same transaction,
4607 * AND the blocks are associated with the same group.
4609 static int can_merge(struct ext4_free_data *entry1,
4610 struct ext4_free_data *entry2)
4612 if ((entry1->t_tid == entry2->t_tid) &&
4613 (entry1->group == entry2->group) &&
4614 ((entry1->start_blk + entry1->count) == entry2->start_blk))
4619 static noinline_for_stack int
4620 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
4621 struct ext4_free_data *new_entry)
4623 ext4_grpblk_t block;
4624 struct ext4_free_data *entry;
4625 struct ext4_group_info *db = e4b->bd_info;
4626 struct super_block *sb = e4b->bd_sb;
4627 struct ext4_sb_info *sbi = EXT4_SB(sb);
4628 struct rb_node **n = &db->bb_free_root.rb_node, *node;
4629 struct rb_node *parent = NULL, *new_node;
4631 BUG_ON(!ext4_handle_valid(handle));
4632 BUG_ON(e4b->bd_bitmap_page == NULL);
4633 BUG_ON(e4b->bd_buddy_page == NULL);
4635 new_node = &new_entry->node;
4636 block = new_entry->start_blk;
4639 /* first free block exent. We need to
4640 protect buddy cache from being freed,
4641 * otherwise we'll refresh it from
4642 * on-disk bitmap and lose not-yet-available
4644 page_cache_get(e4b->bd_buddy_page);
4645 page_cache_get(e4b->bd_bitmap_page);
4649 entry = rb_entry(parent, struct ext4_free_data, node);
4650 if (block < entry->start_blk)
4652 else if (block >= (entry->start_blk + entry->count))
4653 n = &(*n)->rb_right;
4655 ext4_grp_locked_error(sb, e4b->bd_group, __func__,
4656 "Double free of blocks %d (%d %d)",
4657 block, entry->start_blk, entry->count);
4662 rb_link_node(new_node, parent, n);
4663 rb_insert_color(new_node, &db->bb_free_root);
4665 /* Now try to see the extent can be merged to left and right */
4666 node = rb_prev(new_node);
4668 entry = rb_entry(node, struct ext4_free_data, node);
4669 if (can_merge(entry, new_entry)) {
4670 new_entry->start_blk = entry->start_blk;
4671 new_entry->count += entry->count;
4672 rb_erase(node, &(db->bb_free_root));
4673 spin_lock(&sbi->s_md_lock);
4674 list_del(&entry->list);
4675 spin_unlock(&sbi->s_md_lock);
4676 kmem_cache_free(ext4_free_ext_cachep, entry);
4680 node = rb_next(new_node);
4682 entry = rb_entry(node, struct ext4_free_data, node);
4683 if (can_merge(new_entry, entry)) {
4684 new_entry->count += entry->count;
4685 rb_erase(node, &(db->bb_free_root));
4686 spin_lock(&sbi->s_md_lock);
4687 list_del(&entry->list);
4688 spin_unlock(&sbi->s_md_lock);
4689 kmem_cache_free(ext4_free_ext_cachep, entry);
4692 /* Add the extent to transaction's private list */
4693 spin_lock(&sbi->s_md_lock);
4694 list_add(&new_entry->list, &handle->h_transaction->t_private_list);
4695 spin_unlock(&sbi->s_md_lock);
4700 * Main entry point into mballoc to free blocks
4702 void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
4703 ext4_fsblk_t block, unsigned long count,
4704 int metadata, unsigned long *freed)
4706 struct buffer_head *bitmap_bh = NULL;
4707 struct super_block *sb = inode->i_sb;
4708 struct ext4_allocation_context *ac = NULL;
4709 struct ext4_group_desc *gdp;
4710 struct ext4_super_block *es;
4711 unsigned int overflow;
4713 struct buffer_head *gd_bh;
4714 ext4_group_t block_group;
4715 struct ext4_sb_info *sbi;
4716 struct ext4_buddy e4b;
4723 es = EXT4_SB(sb)->s_es;
4724 if (block < le32_to_cpu(es->s_first_data_block) ||
4725 block + count < block ||
4726 block + count > ext4_blocks_count(es)) {
4727 ext4_error(sb, __func__,
4728 "Freeing blocks not in datazone - "
4729 "block = %llu, count = %lu", block, count);
4733 ext4_debug("freeing block %llu\n", block);
4734 trace_ext4_free_blocks(inode, block, count, metadata);
4736 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4738 ac->ac_op = EXT4_MB_HISTORY_FREE;
4739 ac->ac_inode = inode;
4745 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4748 * Check to see if we are freeing blocks across a group
4751 if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4752 overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
4755 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
4760 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
4766 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4767 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4768 in_range(block, ext4_inode_table(sb, gdp),
4769 EXT4_SB(sb)->s_itb_per_group) ||
4770 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4771 EXT4_SB(sb)->s_itb_per_group)) {
4773 ext4_error(sb, __func__,
4774 "Freeing blocks in system zone - "
4775 "Block = %llu, count = %lu", block, count);
4776 /* err = 0. ext4_std_error should be a no op */
4780 BUFFER_TRACE(bitmap_bh, "getting write access");
4781 err = ext4_journal_get_write_access(handle, bitmap_bh);
4786 * We are about to modify some metadata. Call the journal APIs
4787 * to unshare ->b_data if a currently-committing transaction is
4790 BUFFER_TRACE(gd_bh, "get_write_access");
4791 err = ext4_journal_get_write_access(handle, gd_bh);
4794 #ifdef AGGRESSIVE_CHECK
4797 for (i = 0; i < count; i++)
4798 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4802 ac->ac_b_ex.fe_group = block_group;
4803 ac->ac_b_ex.fe_start = bit;
4804 ac->ac_b_ex.fe_len = count;
4805 ext4_mb_store_history(ac);
4808 err = ext4_mb_load_buddy(sb, block_group, &e4b);
4811 if (metadata && ext4_handle_valid(handle)) {
4812 struct ext4_free_data *new_entry;
4814 * blocks being freed are metadata. these blocks shouldn't
4815 * be used until this transaction is committed
4817 new_entry = kmem_cache_alloc(ext4_free_ext_cachep, GFP_NOFS);
4818 new_entry->start_blk = bit;
4819 new_entry->group = block_group;
4820 new_entry->count = count;
4821 new_entry->t_tid = handle->h_transaction->t_tid;
4823 ext4_lock_group(sb, block_group);
4824 mb_clear_bits(bitmap_bh->b_data, bit, count);
4825 ext4_mb_free_metadata(handle, &e4b, new_entry);
4827 /* need to update group_info->bb_free and bitmap
4828 * with group lock held. generate_buddy look at
4829 * them with group lock_held
4831 ext4_lock_group(sb, block_group);
4832 mb_clear_bits(bitmap_bh->b_data, bit, count);
4833 mb_free_blocks(inode, &e4b, bit, count);
4834 ext4_mb_return_to_preallocation(inode, &e4b, block, count);
4837 ret = ext4_free_blks_count(sb, gdp) + count;
4838 ext4_free_blks_set(sb, gdp, ret);
4839 gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
4840 ext4_unlock_group(sb, block_group);
4841 percpu_counter_add(&sbi->s_freeblocks_counter, count);
4843 if (sbi->s_log_groups_per_flex) {
4844 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
4845 atomic_add(count, &sbi->s_flex_groups[flex_group].free_blocks);
4848 ext4_mb_release_desc(&e4b);
4852 /* We dirtied the bitmap block */
4853 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4854 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
4856 /* And the group descriptor block */
4857 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4858 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
4862 if (overflow && !err) {
4871 ext4_std_error(sb, err);
4873 kmem_cache_free(ext4_ac_cachep, ac);