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
27 * - test ext4_ext_search_left() and ext4_ext_search_right()
28 * - search for metadata in few groups
31 * - normalization should take into account whether file is still open
32 * - discard preallocations if no free space left (policy?)
33 * - don't normalize tails
35 * - reservation for superuser
38 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
39 * - track min/max extents in each group for better group selection
40 * - mb_mark_used() may allocate chunk right after splitting buddy
41 * - tree of groups sorted by number of free blocks
46 * The allocation request involve request for multiple number of blocks
47 * near to the goal(block) value specified.
49 * During initialization phase of the allocator we decide to use the group
50 * preallocation or inode preallocation depending on the size file. The
51 * size of the file could be the resulting file size we would have after
52 * allocation or the current file size which ever is larger. If the size is
53 * less that sbi->s_mb_stream_request we select the group
54 * preallocation. The default value of s_mb_stream_request is 16
55 * blocks. This can also be tuned via
56 * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms
57 * of number of blocks.
59 * The main motivation for having small file use group preallocation is to
60 * ensure that we have small file closer in the disk.
62 * First stage the allocator looks at the inode prealloc list
63 * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for
64 * this particular inode. The inode prealloc space is represented as:
66 * pa_lstart -> the logical start block for this prealloc space
67 * pa_pstart -> the physical start block for this prealloc space
68 * pa_len -> lenght for this prealloc space
69 * pa_free -> free space available in this prealloc space
71 * The inode preallocation space is used looking at the _logical_ start
72 * block. If only the logical file block falls within the range of prealloc
73 * space we will consume the particular prealloc space. This make sure that
74 * that the we have contiguous physical blocks representing the file blocks
76 * The important thing to be noted in case of inode prealloc space is that
77 * we don't modify the values associated to inode prealloc space except
80 * If we are not able to find blocks in the inode prealloc space and if we
81 * have the group allocation flag set then we look at the locality group
82 * prealloc space. These are per CPU prealloc list repreasented as
84 * ext4_sb_info.s_locality_groups[smp_processor_id()]
86 * The reason for having a per cpu locality group is to reduce the contention
87 * between CPUs. It is possible to get scheduled at this point.
89 * The locality group prealloc space is used looking at whether we have
90 * enough free space (pa_free) withing the prealloc space.
92 * If we can't allocate blocks via inode prealloc or/and locality group
93 * prealloc then we look at the buddy cache. The buddy cache is represented
94 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
95 * mapped to the buddy and bitmap information regarding different
96 * groups. The buddy information is attached to buddy cache inode so that
97 * we can access them through the page cache. The information regarding
98 * each group is loaded via ext4_mb_load_buddy. The information involve
99 * block bitmap and buddy information. The information are stored in the
103 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
106 * one block each for bitmap and buddy information. So for each group we
107 * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
108 * blocksize) blocks. So it can have information regarding groups_per_page
109 * which is blocks_per_page/2
111 * The buddy cache inode is not stored on disk. The inode is thrown
112 * away when the filesystem is unmounted.
114 * We look for count number of blocks in the buddy cache. If we were able
115 * to locate that many free blocks we return with additional information
116 * regarding rest of the contiguous physical block available
118 * Before allocating blocks via buddy cache we normalize the request
119 * blocks. This ensure we ask for more blocks that we needed. The extra
120 * blocks that we get after allocation is added to the respective prealloc
121 * list. In case of inode preallocation we follow a list of heuristics
122 * based on file size. This can be found in ext4_mb_normalize_request. If
123 * we are doing a group prealloc we try to normalize the request to
124 * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to
125 * 512 blocks. This can be tuned via
126 * /proc/fs/ext4/<partition/group_prealloc. The value is represented in
127 * terms of number of blocks. If we have mounted the file system with -O
128 * stripe=<value> option the group prealloc request is normalized to the
129 * stripe value (sbi->s_stripe)
131 * The regular allocator(using the buddy cache) support few tunables.
133 * /proc/fs/ext4/<partition>/min_to_scan
134 * /proc/fs/ext4/<partition>/max_to_scan
135 * /proc/fs/ext4/<partition>/order2_req
137 * The regular allocator use buddy scan only if the request len is power of
138 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
139 * value of s_mb_order2_reqs can be tuned via
140 * /proc/fs/ext4/<partition>/order2_req. If the request len is equal to
141 * stripe size (sbi->s_stripe), we try to search for contigous block in
142 * stripe size. This should result in better allocation on RAID setup. If
143 * not we search in the specific group using bitmap for best extents. The
144 * tunable min_to_scan and max_to_scan controll the behaviour here.
145 * min_to_scan indicate how long the mballoc __must__ look for a best
146 * extent and max_to_scanindicate how long the mballoc __can__ look for a
147 * best extent in the found extents. Searching for the blocks starts with
148 * the group specified as the goal value in allocation context via
149 * ac_g_ex. Each group is first checked based on the criteria whether it
150 * can used for allocation. ext4_mb_good_group explains how the groups are
153 * Both the prealloc space are getting populated as above. So for the first
154 * request we will hit the buddy cache which will result in this prealloc
155 * space getting filled. The prealloc space is then later used for the
156 * subsequent request.
160 * mballoc operates on the following data:
162 * - in-core buddy (actually includes buddy and bitmap)
163 * - preallocation descriptors (PAs)
165 * there are two types of preallocations:
167 * assiged to specific inode and can be used for this inode only.
168 * it describes part of inode's space preallocated to specific
169 * physical blocks. any block from that preallocated can be used
170 * independent. the descriptor just tracks number of blocks left
171 * unused. so, before taking some block from descriptor, one must
172 * make sure corresponded logical block isn't allocated yet. this
173 * also means that freeing any block within descriptor's range
174 * must discard all preallocated blocks.
176 * assigned to specific locality group which does not translate to
177 * permanent set of inodes: inode can join and leave group. space
178 * from this type of preallocation can be used for any inode. thus
179 * it's consumed from the beginning to the end.
181 * relation between them can be expressed as:
182 * in-core buddy = on-disk bitmap + preallocation descriptors
184 * this mean blocks mballoc considers used are:
185 * - allocated blocks (persistent)
186 * - preallocated blocks (non-persistent)
188 * consistency in mballoc world means that at any time a block is either
189 * free or used in ALL structures. notice: "any time" should not be read
190 * literally -- time is discrete and delimited by locks.
192 * to keep it simple, we don't use block numbers, instead we count number of
193 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
195 * all operations can be expressed as:
196 * - init buddy: buddy = on-disk + PAs
197 * - new PA: buddy += N; PA = N
198 * - use inode PA: on-disk += N; PA -= N
199 * - discard inode PA buddy -= on-disk - PA; PA = 0
200 * - use locality group PA on-disk += N; PA -= N
201 * - discard locality group PA buddy -= PA; PA = 0
202 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
203 * is used in real operation because we can't know actual used
204 * bits from PA, only from on-disk bitmap
206 * if we follow this strict logic, then all operations above should be atomic.
207 * given some of them can block, we'd have to use something like semaphores
208 * killing performance on high-end SMP hardware. let's try to relax it using
209 * the following knowledge:
210 * 1) if buddy is referenced, it's already initialized
211 * 2) while block is used in buddy and the buddy is referenced,
212 * nobody can re-allocate that block
213 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
214 * bit set and PA claims same block, it's OK. IOW, one can set bit in
215 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
218 * so, now we're building a concurrency table:
221 * blocks for PA are allocated in the buddy, buddy must be referenced
222 * until PA is linked to allocation group to avoid concurrent buddy init
224 * we need to make sure that either on-disk bitmap or PA has uptodate data
225 * given (3) we care that PA-=N operation doesn't interfere with init
227 * the simplest way would be to have buddy initialized by the discard
228 * - use locality group PA
229 * again PA-=N must be serialized with init
230 * - discard locality group PA
231 * the simplest way would be to have buddy initialized by the discard
234 * i_data_sem serializes them
236 * discard process must wait until PA isn't used by another process
237 * - use locality group PA
238 * some mutex should serialize them
239 * - discard locality group PA
240 * discard process must wait until PA isn't used by another process
243 * i_data_sem or another mutex should serializes them
245 * discard process must wait until PA isn't used by another process
246 * - use locality group PA
247 * nothing wrong here -- they're different PAs covering different blocks
248 * - discard locality group PA
249 * discard process must wait until PA isn't used by another process
251 * now we're ready to make few consequences:
252 * - PA is referenced and while it is no discard is possible
253 * - PA is referenced until block isn't marked in on-disk bitmap
254 * - PA changes only after on-disk bitmap
255 * - discard must not compete with init. either init is done before
256 * any discard or they're serialized somehow
257 * - buddy init as sum of on-disk bitmap and PAs is done atomically
259 * a special case when we've used PA to emptiness. no need to modify buddy
260 * in this case, but we should care about concurrent init
265 * Logic in few words:
270 * mark bits in on-disk bitmap
273 * - use preallocation:
274 * find proper PA (per-inode or group)
276 * mark bits in on-disk bitmap
282 * mark bits in on-disk bitmap
285 * - discard preallocations in group:
287 * move them onto local list
288 * load on-disk bitmap
290 * remove PA from object (inode or locality group)
291 * mark free blocks in-core
293 * - discard inode's preallocations:
300 * - bitlock on a group (group)
301 * - object (inode/locality) (object)
312 * - release consumed pa:
317 * - generate in-core bitmap:
321 * - discard all for given object (inode, locality group):
326 * - discard all for given group:
334 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
336 #if BITS_PER_LONG == 64
337 *bit += ((unsigned long) addr & 7UL) << 3;
338 addr = (void *) ((unsigned long) addr & ~7UL);
339 #elif BITS_PER_LONG == 32
340 *bit += ((unsigned long) addr & 3UL) << 3;
341 addr = (void *) ((unsigned long) addr & ~3UL);
343 #error "how many bits you are?!"
348 static inline int mb_test_bit(int bit, void *addr)
351 * ext4_test_bit on architecture like powerpc
352 * needs unsigned long aligned address
354 addr = mb_correct_addr_and_bit(&bit, addr);
355 return ext4_test_bit(bit, addr);
358 static inline void mb_set_bit(int bit, void *addr)
360 addr = mb_correct_addr_and_bit(&bit, addr);
361 ext4_set_bit(bit, addr);
364 static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr)
366 addr = mb_correct_addr_and_bit(&bit, addr);
367 ext4_set_bit_atomic(lock, bit, addr);
370 static inline void mb_clear_bit(int bit, void *addr)
372 addr = mb_correct_addr_and_bit(&bit, addr);
373 ext4_clear_bit(bit, addr);
376 static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
378 addr = mb_correct_addr_and_bit(&bit, addr);
379 ext4_clear_bit_atomic(lock, 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 BUG_ON(!ext4_is_group_locked(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);
449 ext4_error(sb, __func__, "double-free of inode"
450 " %lu's block %llu(bit %u in group %lu)\n",
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 BUG_ON(!ext4_is_group_locked(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 %lu "
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;
537 if (!test_opt(sb, MBALLOC))
541 static int mb_check_counter;
542 if (mb_check_counter++ % 100 != 0)
547 buddy = mb_find_buddy(e4b, order, &max);
548 MB_CHECK_ASSERT(buddy);
549 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
550 MB_CHECK_ASSERT(buddy2);
551 MB_CHECK_ASSERT(buddy != buddy2);
552 MB_CHECK_ASSERT(max * 2 == max2);
555 for (i = 0; i < max; i++) {
557 if (mb_test_bit(i, buddy)) {
558 /* only single bit in buddy2 may be 1 */
559 if (!mb_test_bit(i << 1, buddy2)) {
561 mb_test_bit((i<<1)+1, buddy2));
562 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
564 mb_test_bit(i << 1, buddy2));
569 /* both bits in buddy2 must be 0 */
570 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
571 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
573 for (j = 0; j < (1 << order); j++) {
574 k = (i * (1 << order)) + j;
576 !mb_test_bit(k, EXT4_MB_BITMAP(e4b)));
580 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
585 buddy = mb_find_buddy(e4b, 0, &max);
586 for (i = 0; i < max; i++) {
587 if (!mb_test_bit(i, buddy)) {
588 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
596 /* check used bits only */
597 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
598 buddy2 = mb_find_buddy(e4b, j, &max2);
600 MB_CHECK_ASSERT(k < max2);
601 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
604 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
605 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
607 grp = ext4_get_group_info(sb, e4b->bd_group);
608 buddy = mb_find_buddy(e4b, 0, &max);
609 list_for_each(cur, &grp->bb_prealloc_list) {
610 ext4_group_t groupnr;
611 struct ext4_prealloc_space *pa;
612 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
613 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
614 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
615 for (i = 0; i < pa->pa_len; i++)
616 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
620 #undef MB_CHECK_ASSERT
621 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
622 __FILE__, __func__, __LINE__)
624 #define mb_check_buddy(e4b)
627 /* FIXME!! need more doc */
628 static void ext4_mb_mark_free_simple(struct super_block *sb,
629 void *buddy, unsigned first, int len,
630 struct ext4_group_info *grp)
632 struct ext4_sb_info *sbi = EXT4_SB(sb);
635 unsigned short chunk;
636 unsigned short border;
638 BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb));
640 border = 2 << sb->s_blocksize_bits;
643 /* find how many blocks can be covered since this position */
644 max = ffs(first | border) - 1;
646 /* find how many blocks of power 2 we need to mark */
653 /* mark multiblock chunks only */
654 grp->bb_counters[min]++;
656 mb_clear_bit(first >> min,
657 buddy + sbi->s_mb_offsets[min]);
664 static void ext4_mb_generate_buddy(struct super_block *sb,
665 void *buddy, void *bitmap, ext4_group_t group)
667 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
668 unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
669 unsigned short i = 0;
670 unsigned short first;
673 unsigned fragments = 0;
674 unsigned long long period = get_cycles();
676 /* initialize buddy from bitmap which is aggregation
677 * of on-disk bitmap and preallocations */
678 i = mb_find_next_zero_bit(bitmap, max, 0);
679 grp->bb_first_free = i;
683 i = mb_find_next_bit(bitmap, max, i);
687 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
689 grp->bb_counters[0]++;
691 i = mb_find_next_zero_bit(bitmap, max, i);
693 grp->bb_fragments = fragments;
695 if (free != grp->bb_free) {
696 ext4_error(sb, __func__,
697 "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
698 group, free, grp->bb_free);
700 * If we intent to continue, we consider group descritor
701 * corrupt and update bb_free using bitmap value
706 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
708 period = get_cycles() - period;
709 spin_lock(&EXT4_SB(sb)->s_bal_lock);
710 EXT4_SB(sb)->s_mb_buddies_generated++;
711 EXT4_SB(sb)->s_mb_generation_time += period;
712 spin_unlock(&EXT4_SB(sb)->s_bal_lock);
715 /* The buddy information is attached the buddy cache inode
716 * for convenience. The information regarding each group
717 * is loaded via ext4_mb_load_buddy. The information involve
718 * block bitmap and buddy information. The information are
719 * stored in the inode as
722 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
725 * one block each for bitmap and buddy information.
726 * So for each group we take up 2 blocks. A page can
727 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
728 * So it can have information regarding groups_per_page which
729 * is blocks_per_page/2
732 static int ext4_mb_init_cache(struct page *page, char *incore)
739 ext4_group_t first_group;
741 struct super_block *sb;
742 struct buffer_head *bhs;
743 struct buffer_head **bh;
748 mb_debug("init page %lu\n", page->index);
750 inode = page->mapping->host;
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 >= EXT4_SB(sb)->s_groups_count)
779 desc = ext4_get_group_desc(sb, first_group + i, NULL);
784 bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc));
788 if (bh_uptodate_or_lock(bh[i]))
791 spin_lock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
792 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
793 ext4_init_block_bitmap(sb, bh[i],
794 first_group + i, desc);
795 set_buffer_uptodate(bh[i]);
796 unlock_buffer(bh[i]);
797 spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
800 spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
802 bh[i]->b_end_io = end_buffer_read_sync;
803 submit_bh(READ, bh[i]);
804 mb_debug("read bitmap for group %lu\n", first_group + i);
807 /* wait for I/O completion */
808 for (i = 0; i < groups_per_page && bh[i]; i++)
809 wait_on_buffer(bh[i]);
812 for (i = 0; i < groups_per_page && bh[i]; i++)
813 if (!buffer_uptodate(bh[i]))
817 first_block = page->index * blocks_per_page;
818 for (i = 0; i < blocks_per_page; i++) {
820 struct ext4_group_info *grinfo;
822 group = (first_block + i) >> 1;
823 if (group >= EXT4_SB(sb)->s_groups_count)
827 * data carry information regarding this
828 * particular group in the format specified
832 data = page_address(page) + (i * blocksize);
833 bitmap = bh[group - first_group]->b_data;
836 * We place the buddy block and bitmap block
839 if ((first_block + i) & 1) {
840 /* this is block of buddy */
841 BUG_ON(incore == NULL);
842 mb_debug("put buddy for group %u in page %lu/%x\n",
843 group, page->index, i * blocksize);
844 memset(data, 0xff, blocksize);
845 grinfo = ext4_get_group_info(sb, group);
846 grinfo->bb_fragments = 0;
847 memset(grinfo->bb_counters, 0,
848 sizeof(unsigned short)*(sb->s_blocksize_bits+2));
850 * incore got set to the group block bitmap below
852 ext4_mb_generate_buddy(sb, data, incore, group);
855 /* this is block of bitmap */
856 BUG_ON(incore != NULL);
857 mb_debug("put bitmap for group %u in page %lu/%x\n",
858 group, page->index, i * blocksize);
860 /* see comments in ext4_mb_put_pa() */
861 ext4_lock_group(sb, group);
862 memcpy(data, bitmap, blocksize);
864 /* mark all preallocated blks used in in-core bitmap */
865 ext4_mb_generate_from_pa(sb, data, group);
866 ext4_unlock_group(sb, group);
868 /* set incore so that the buddy information can be
869 * generated using this
874 SetPageUptodate(page);
878 for (i = 0; i < groups_per_page && bh[i]; i++)
886 static noinline_for_stack int
887 ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
888 struct ext4_buddy *e4b)
890 struct ext4_sb_info *sbi = EXT4_SB(sb);
891 struct inode *inode = sbi->s_buddy_cache;
899 mb_debug("load group %lu\n", group);
901 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
903 e4b->bd_blkbits = sb->s_blocksize_bits;
904 e4b->bd_info = ext4_get_group_info(sb, group);
906 e4b->bd_group = group;
907 e4b->bd_buddy_page = NULL;
908 e4b->bd_bitmap_page = NULL;
911 * the buddy cache inode stores the block bitmap
912 * and buddy information in consecutive blocks.
913 * So for each group we need two blocks.
916 pnum = block / blocks_per_page;
917 poff = block % blocks_per_page;
919 /* we could use find_or_create_page(), but it locks page
920 * what we'd like to avoid in fast path ... */
921 page = find_get_page(inode->i_mapping, pnum);
922 if (page == NULL || !PageUptodate(page)) {
924 page_cache_release(page);
925 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
927 BUG_ON(page->mapping != inode->i_mapping);
928 if (!PageUptodate(page)) {
929 ret = ext4_mb_init_cache(page, NULL);
934 mb_cmp_bitmaps(e4b, page_address(page) +
935 (poff * sb->s_blocksize));
940 if (page == NULL || !PageUptodate(page)) {
944 e4b->bd_bitmap_page = page;
945 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
946 mark_page_accessed(page);
949 pnum = block / blocks_per_page;
950 poff = block % blocks_per_page;
952 page = find_get_page(inode->i_mapping, pnum);
953 if (page == NULL || !PageUptodate(page)) {
955 page_cache_release(page);
956 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
958 BUG_ON(page->mapping != inode->i_mapping);
959 if (!PageUptodate(page)) {
960 ret = ext4_mb_init_cache(page, e4b->bd_bitmap);
969 if (page == NULL || !PageUptodate(page)) {
973 e4b->bd_buddy_page = page;
974 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
975 mark_page_accessed(page);
977 BUG_ON(e4b->bd_bitmap_page == NULL);
978 BUG_ON(e4b->bd_buddy_page == NULL);
983 if (e4b->bd_bitmap_page)
984 page_cache_release(e4b->bd_bitmap_page);
985 if (e4b->bd_buddy_page)
986 page_cache_release(e4b->bd_buddy_page);
987 e4b->bd_buddy = NULL;
988 e4b->bd_bitmap = NULL;
992 static void ext4_mb_release_desc(struct ext4_buddy *e4b)
994 if (e4b->bd_bitmap_page)
995 page_cache_release(e4b->bd_bitmap_page);
996 if (e4b->bd_buddy_page)
997 page_cache_release(e4b->bd_buddy_page);
1001 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1006 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
1007 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1009 bb = EXT4_MB_BUDDY(e4b);
1010 while (order <= e4b->bd_blkbits + 1) {
1012 if (!mb_test_bit(block, bb)) {
1013 /* this block is part of buddy of order 'order' */
1016 bb += 1 << (e4b->bd_blkbits - order);
1022 static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
1028 if ((cur & 31) == 0 && (len - cur) >= 32) {
1029 /* fast path: clear whole word at once */
1030 addr = bm + (cur >> 3);
1035 mb_clear_bit_atomic(lock, cur, bm);
1040 static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
1046 if ((cur & 31) == 0 && (len - cur) >= 32) {
1047 /* fast path: set whole word at once */
1048 addr = bm + (cur >> 3);
1053 mb_set_bit_atomic(lock, cur, bm);
1058 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1059 int first, int count)
1066 struct super_block *sb = e4b->bd_sb;
1068 BUG_ON(first + count > (sb->s_blocksize << 3));
1069 BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
1070 mb_check_buddy(e4b);
1071 mb_free_blocks_double(inode, e4b, first, count);
1073 e4b->bd_info->bb_free += count;
1074 if (first < e4b->bd_info->bb_first_free)
1075 e4b->bd_info->bb_first_free = first;
1077 /* let's maintain fragments counter */
1079 block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b));
1080 if (first + count < EXT4_SB(sb)->s_mb_maxs[0])
1081 max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b));
1083 e4b->bd_info->bb_fragments--;
1084 else if (!block && !max)
1085 e4b->bd_info->bb_fragments++;
1087 /* let's maintain buddy itself */
1088 while (count-- > 0) {
1092 if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) {
1093 ext4_fsblk_t blocknr;
1094 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
1097 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1098 ext4_unlock_group(sb, e4b->bd_group);
1099 ext4_error(sb, __func__, "double-free of inode"
1100 " %lu's block %llu(bit %u in group %lu)\n",
1101 inode ? inode->i_ino : 0, blocknr, block,
1103 ext4_lock_group(sb, e4b->bd_group);
1105 mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
1106 e4b->bd_info->bb_counters[order]++;
1108 /* start of the buddy */
1109 buddy = mb_find_buddy(e4b, order, &max);
1113 if (mb_test_bit(block, buddy) ||
1114 mb_test_bit(block + 1, buddy))
1117 /* both the buddies are free, try to coalesce them */
1118 buddy2 = mb_find_buddy(e4b, order + 1, &max);
1124 /* for special purposes, we don't set
1125 * free bits in bitmap */
1126 mb_set_bit(block, buddy);
1127 mb_set_bit(block + 1, buddy);
1129 e4b->bd_info->bb_counters[order]--;
1130 e4b->bd_info->bb_counters[order]--;
1134 e4b->bd_info->bb_counters[order]++;
1136 mb_clear_bit(block, buddy2);
1140 mb_check_buddy(e4b);
1143 static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
1144 int needed, struct ext4_free_extent *ex)
1151 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1154 buddy = mb_find_buddy(e4b, order, &max);
1155 BUG_ON(buddy == NULL);
1156 BUG_ON(block >= max);
1157 if (mb_test_bit(block, buddy)) {
1164 /* FIXME dorp order completely ? */
1165 if (likely(order == 0)) {
1166 /* find actual order */
1167 order = mb_find_order_for_block(e4b, block);
1168 block = block >> order;
1171 ex->fe_len = 1 << order;
1172 ex->fe_start = block << order;
1173 ex->fe_group = e4b->bd_group;
1175 /* calc difference from given start */
1176 next = next - ex->fe_start;
1178 ex->fe_start += next;
1180 while (needed > ex->fe_len &&
1181 (buddy = mb_find_buddy(e4b, order, &max))) {
1183 if (block + 1 >= max)
1186 next = (block + 1) * (1 << order);
1187 if (mb_test_bit(next, EXT4_MB_BITMAP(e4b)))
1190 ord = mb_find_order_for_block(e4b, next);
1193 block = next >> order;
1194 ex->fe_len += 1 << order;
1197 BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3)));
1201 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1207 int start = ex->fe_start;
1208 int len = ex->fe_len;
1213 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1214 BUG_ON(e4b->bd_group != ex->fe_group);
1215 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1216 mb_check_buddy(e4b);
1217 mb_mark_used_double(e4b, start, len);
1219 e4b->bd_info->bb_free -= len;
1220 if (e4b->bd_info->bb_first_free == start)
1221 e4b->bd_info->bb_first_free += len;
1223 /* let's maintain fragments counter */
1225 mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b));
1226 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1227 max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b));
1229 e4b->bd_info->bb_fragments++;
1230 else if (!mlen && !max)
1231 e4b->bd_info->bb_fragments--;
1233 /* let's maintain buddy itself */
1235 ord = mb_find_order_for_block(e4b, start);
1237 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1238 /* the whole chunk may be allocated at once! */
1240 buddy = mb_find_buddy(e4b, ord, &max);
1241 BUG_ON((start >> ord) >= max);
1242 mb_set_bit(start >> ord, buddy);
1243 e4b->bd_info->bb_counters[ord]--;
1250 /* store for history */
1252 ret = len | (ord << 16);
1254 /* we have to split large buddy */
1256 buddy = mb_find_buddy(e4b, ord, &max);
1257 mb_set_bit(start >> ord, buddy);
1258 e4b->bd_info->bb_counters[ord]--;
1261 cur = (start >> ord) & ~1U;
1262 buddy = mb_find_buddy(e4b, ord, &max);
1263 mb_clear_bit(cur, buddy);
1264 mb_clear_bit(cur + 1, buddy);
1265 e4b->bd_info->bb_counters[ord]++;
1266 e4b->bd_info->bb_counters[ord]++;
1269 mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group),
1270 EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
1271 mb_check_buddy(e4b);
1277 * Must be called under group lock!
1279 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1280 struct ext4_buddy *e4b)
1282 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1285 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1286 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1288 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1289 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1290 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1292 /* preallocation can change ac_b_ex, thus we store actually
1293 * allocated blocks for history */
1294 ac->ac_f_ex = ac->ac_b_ex;
1296 ac->ac_status = AC_STATUS_FOUND;
1297 ac->ac_tail = ret & 0xffff;
1298 ac->ac_buddy = ret >> 16;
1300 /* XXXXXXX: SUCH A HORRIBLE **CK */
1302 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1303 get_page(ac->ac_bitmap_page);
1304 ac->ac_buddy_page = e4b->bd_buddy_page;
1305 get_page(ac->ac_buddy_page);
1307 /* store last allocated for subsequent stream allocation */
1308 if ((ac->ac_flags & EXT4_MB_HINT_DATA)) {
1309 spin_lock(&sbi->s_md_lock);
1310 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1311 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1312 spin_unlock(&sbi->s_md_lock);
1317 * regular allocator, for general purposes allocation
1320 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1321 struct ext4_buddy *e4b,
1324 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1325 struct ext4_free_extent *bex = &ac->ac_b_ex;
1326 struct ext4_free_extent *gex = &ac->ac_g_ex;
1327 struct ext4_free_extent ex;
1331 * We don't want to scan for a whole year
1333 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1334 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1335 ac->ac_status = AC_STATUS_BREAK;
1340 * Haven't found good chunk so far, let's continue
1342 if (bex->fe_len < gex->fe_len)
1345 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1346 && bex->fe_group == e4b->bd_group) {
1347 /* recheck chunk's availability - we don't know
1348 * when it was found (within this lock-unlock
1350 max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex);
1351 if (max >= gex->fe_len) {
1352 ext4_mb_use_best_found(ac, e4b);
1359 * The routine checks whether found extent is good enough. If it is,
1360 * then the extent gets marked used and flag is set to the context
1361 * to stop scanning. Otherwise, the extent is compared with the
1362 * previous found extent and if new one is better, then it's stored
1363 * in the context. Later, the best found extent will be used, if
1364 * mballoc can't find good enough extent.
1366 * FIXME: real allocation policy is to be designed yet!
1368 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1369 struct ext4_free_extent *ex,
1370 struct ext4_buddy *e4b)
1372 struct ext4_free_extent *bex = &ac->ac_b_ex;
1373 struct ext4_free_extent *gex = &ac->ac_g_ex;
1375 BUG_ON(ex->fe_len <= 0);
1376 BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1377 BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1378 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1383 * The special case - take what you catch first
1385 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1387 ext4_mb_use_best_found(ac, e4b);
1392 * Let's check whether the chuck is good enough
1394 if (ex->fe_len == gex->fe_len) {
1396 ext4_mb_use_best_found(ac, e4b);
1401 * If this is first found extent, just store it in the context
1403 if (bex->fe_len == 0) {
1409 * If new found extent is better, store it in the context
1411 if (bex->fe_len < gex->fe_len) {
1412 /* if the request isn't satisfied, any found extent
1413 * larger than previous best one is better */
1414 if (ex->fe_len > bex->fe_len)
1416 } else if (ex->fe_len > gex->fe_len) {
1417 /* if the request is satisfied, then we try to find
1418 * an extent that still satisfy the request, but is
1419 * smaller than previous one */
1420 if (ex->fe_len < bex->fe_len)
1424 ext4_mb_check_limits(ac, e4b, 0);
1427 static int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1428 struct ext4_buddy *e4b)
1430 struct ext4_free_extent ex = ac->ac_b_ex;
1431 ext4_group_t group = ex.fe_group;
1435 BUG_ON(ex.fe_len <= 0);
1436 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1440 ext4_lock_group(ac->ac_sb, group);
1441 max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex);
1445 ext4_mb_use_best_found(ac, e4b);
1448 ext4_unlock_group(ac->ac_sb, group);
1449 ext4_mb_release_desc(e4b);
1454 static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1455 struct ext4_buddy *e4b)
1457 ext4_group_t group = ac->ac_g_ex.fe_group;
1460 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1461 struct ext4_super_block *es = sbi->s_es;
1462 struct ext4_free_extent ex;
1464 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1467 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1471 ext4_lock_group(ac->ac_sb, group);
1472 max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start,
1473 ac->ac_g_ex.fe_len, &ex);
1475 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1478 start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) +
1479 ex.fe_start + le32_to_cpu(es->s_first_data_block);
1480 /* use do_div to get remainder (would be 64-bit modulo) */
1481 if (do_div(start, sbi->s_stripe) == 0) {
1484 ext4_mb_use_best_found(ac, e4b);
1486 } else if (max >= ac->ac_g_ex.fe_len) {
1487 BUG_ON(ex.fe_len <= 0);
1488 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1489 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1492 ext4_mb_use_best_found(ac, e4b);
1493 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1494 /* Sometimes, caller may want to merge even small
1495 * number of blocks to an existing extent */
1496 BUG_ON(ex.fe_len <= 0);
1497 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1498 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1501 ext4_mb_use_best_found(ac, e4b);
1503 ext4_unlock_group(ac->ac_sb, group);
1504 ext4_mb_release_desc(e4b);
1510 * The routine scans buddy structures (not bitmap!) from given order
1511 * to max order and tries to find big enough chunk to satisfy the req
1513 static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1514 struct ext4_buddy *e4b)
1516 struct super_block *sb = ac->ac_sb;
1517 struct ext4_group_info *grp = e4b->bd_info;
1523 BUG_ON(ac->ac_2order <= 0);
1524 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1525 if (grp->bb_counters[i] == 0)
1528 buddy = mb_find_buddy(e4b, i, &max);
1529 BUG_ON(buddy == NULL);
1531 k = mb_find_next_zero_bit(buddy, max, 0);
1536 ac->ac_b_ex.fe_len = 1 << i;
1537 ac->ac_b_ex.fe_start = k << i;
1538 ac->ac_b_ex.fe_group = e4b->bd_group;
1540 ext4_mb_use_best_found(ac, e4b);
1542 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1544 if (EXT4_SB(sb)->s_mb_stats)
1545 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1552 * The routine scans the group and measures all found extents.
1553 * In order to optimize scanning, caller must pass number of
1554 * free blocks in the group, so the routine can know upper limit.
1556 static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1557 struct ext4_buddy *e4b)
1559 struct super_block *sb = ac->ac_sb;
1560 void *bitmap = EXT4_MB_BITMAP(e4b);
1561 struct ext4_free_extent ex;
1565 free = e4b->bd_info->bb_free;
1568 i = e4b->bd_info->bb_first_free;
1570 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
1571 i = mb_find_next_zero_bit(bitmap,
1572 EXT4_BLOCKS_PER_GROUP(sb), i);
1573 if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
1575 * IF we have corrupt bitmap, we won't find any
1576 * free blocks even though group info says we
1577 * we have free blocks
1579 ext4_error(sb, __func__, "%d free blocks as per "
1580 "group info. But bitmap says 0\n",
1585 mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex);
1586 BUG_ON(ex.fe_len <= 0);
1587 if (free < ex.fe_len) {
1588 ext4_error(sb, __func__, "%d free blocks as per "
1589 "group info. But got %d blocks\n",
1592 * The number of free blocks differs. This mostly
1593 * indicate that the bitmap is corrupt. So exit
1594 * without claiming the space.
1599 ext4_mb_measure_extent(ac, &ex, e4b);
1605 ext4_mb_check_limits(ac, e4b, 1);
1609 * This is a special case for storages like raid5
1610 * we try to find stripe-aligned chunks for stripe-size requests
1611 * XXX should do so at least for multiples of stripe size as well
1613 static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
1614 struct ext4_buddy *e4b)
1616 struct super_block *sb = ac->ac_sb;
1617 struct ext4_sb_info *sbi = EXT4_SB(sb);
1618 void *bitmap = EXT4_MB_BITMAP(e4b);
1619 struct ext4_free_extent ex;
1620 ext4_fsblk_t first_group_block;
1625 BUG_ON(sbi->s_stripe == 0);
1627 /* find first stripe-aligned block in group */
1628 first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb)
1629 + le32_to_cpu(sbi->s_es->s_first_data_block);
1630 a = first_group_block + sbi->s_stripe - 1;
1631 do_div(a, sbi->s_stripe);
1632 i = (a * sbi->s_stripe) - first_group_block;
1634 while (i < EXT4_BLOCKS_PER_GROUP(sb)) {
1635 if (!mb_test_bit(i, bitmap)) {
1636 max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex);
1637 if (max >= sbi->s_stripe) {
1640 ext4_mb_use_best_found(ac, e4b);
1648 static int ext4_mb_good_group(struct ext4_allocation_context *ac,
1649 ext4_group_t group, int cr)
1651 unsigned free, fragments;
1653 struct ext4_group_desc *desc;
1654 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1656 BUG_ON(cr < 0 || cr >= 4);
1657 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp));
1659 free = grp->bb_free;
1660 fragments = grp->bb_fragments;
1668 BUG_ON(ac->ac_2order == 0);
1669 /* If this group is uninitialized, skip it initially */
1670 desc = ext4_get_group_desc(ac->ac_sb, group, NULL);
1671 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
1674 bits = ac->ac_sb->s_blocksize_bits + 1;
1675 for (i = ac->ac_2order; i <= bits; i++)
1676 if (grp->bb_counters[i] > 0)
1680 if ((free / fragments) >= ac->ac_g_ex.fe_len)
1684 if (free >= ac->ac_g_ex.fe_len)
1696 static noinline_for_stack int
1697 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
1704 struct ext4_sb_info *sbi;
1705 struct super_block *sb;
1706 struct ext4_buddy e4b;
1711 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1713 /* first, try the goal */
1714 err = ext4_mb_find_by_goal(ac, &e4b);
1715 if (err || ac->ac_status == AC_STATUS_FOUND)
1718 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
1722 * ac->ac2_order is set only if the fe_len is a power of 2
1723 * if ac2_order is set we also set criteria to 0 so that we
1724 * try exact allocation using buddy.
1726 i = fls(ac->ac_g_ex.fe_len);
1729 * We search using buddy data only if the order of the request
1730 * is greater than equal to the sbi_s_mb_order2_reqs
1731 * You can tune it via /proc/fs/ext4/<partition>/order2_req
1733 if (i >= sbi->s_mb_order2_reqs) {
1735 * This should tell if fe_len is exactly power of 2
1737 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
1738 ac->ac_2order = i - 1;
1741 bsbits = ac->ac_sb->s_blocksize_bits;
1742 /* if stream allocation is enabled, use global goal */
1743 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
1744 isize = i_size_read(ac->ac_inode) >> bsbits;
1748 if (size < sbi->s_mb_stream_request &&
1749 (ac->ac_flags & EXT4_MB_HINT_DATA)) {
1750 /* TBD: may be hot point */
1751 spin_lock(&sbi->s_md_lock);
1752 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
1753 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
1754 spin_unlock(&sbi->s_md_lock);
1756 /* Let's just scan groups to find more-less suitable blocks */
1757 cr = ac->ac_2order ? 0 : 1;
1759 * cr == 0 try to get exact allocation,
1760 * cr == 3 try to get anything
1763 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
1764 ac->ac_criteria = cr;
1766 * searching for the right group start
1767 * from the goal value specified
1769 group = ac->ac_g_ex.fe_group;
1771 for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) {
1772 struct ext4_group_info *grp;
1773 struct ext4_group_desc *desc;
1775 if (group == EXT4_SB(sb)->s_groups_count)
1778 /* quick check to skip empty groups */
1779 grp = ext4_get_group_info(ac->ac_sb, group);
1780 if (grp->bb_free == 0)
1784 * if the group is already init we check whether it is
1785 * a good group and if not we don't load the buddy
1787 if (EXT4_MB_GRP_NEED_INIT(grp)) {
1789 * we need full data about the group
1790 * to make a good selection
1792 err = ext4_mb_load_buddy(sb, group, &e4b);
1795 ext4_mb_release_desc(&e4b);
1799 * If the particular group doesn't satisfy our
1800 * criteria we continue with the next group
1802 if (!ext4_mb_good_group(ac, group, cr))
1805 err = ext4_mb_load_buddy(sb, group, &e4b);
1809 ext4_lock_group(sb, group);
1810 if (!ext4_mb_good_group(ac, group, cr)) {
1811 /* someone did allocation from this group */
1812 ext4_unlock_group(sb, group);
1813 ext4_mb_release_desc(&e4b);
1817 ac->ac_groups_scanned++;
1818 desc = ext4_get_group_desc(sb, group, NULL);
1819 if (cr == 0 || (desc->bg_flags &
1820 cpu_to_le16(EXT4_BG_BLOCK_UNINIT) &&
1821 ac->ac_2order != 0))
1822 ext4_mb_simple_scan_group(ac, &e4b);
1824 ac->ac_g_ex.fe_len == sbi->s_stripe)
1825 ext4_mb_scan_aligned(ac, &e4b);
1827 ext4_mb_complex_scan_group(ac, &e4b);
1829 ext4_unlock_group(sb, group);
1830 ext4_mb_release_desc(&e4b);
1832 if (ac->ac_status != AC_STATUS_CONTINUE)
1837 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
1838 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1840 * We've been searching too long. Let's try to allocate
1841 * the best chunk we've found so far
1844 ext4_mb_try_best_found(ac, &e4b);
1845 if (ac->ac_status != AC_STATUS_FOUND) {
1847 * Someone more lucky has already allocated it.
1848 * The only thing we can do is just take first
1850 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
1852 ac->ac_b_ex.fe_group = 0;
1853 ac->ac_b_ex.fe_start = 0;
1854 ac->ac_b_ex.fe_len = 0;
1855 ac->ac_status = AC_STATUS_CONTINUE;
1856 ac->ac_flags |= EXT4_MB_HINT_FIRST;
1858 atomic_inc(&sbi->s_mb_lost_chunks);
1866 #ifdef EXT4_MB_HISTORY
1867 struct ext4_mb_proc_session {
1868 struct ext4_mb_history *history;
1869 struct super_block *sb;
1874 static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s,
1875 struct ext4_mb_history *hs,
1878 if (hs == s->history + s->max)
1880 if (!first && hs == s->history + s->start)
1882 while (hs->orig.fe_len == 0) {
1884 if (hs == s->history + s->max)
1886 if (hs == s->history + s->start)
1892 static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos)
1894 struct ext4_mb_proc_session *s = seq->private;
1895 struct ext4_mb_history *hs;
1899 return SEQ_START_TOKEN;
1900 hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1);
1903 while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL);
1907 static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v,
1910 struct ext4_mb_proc_session *s = seq->private;
1911 struct ext4_mb_history *hs = v;
1914 if (v == SEQ_START_TOKEN)
1915 return ext4_mb_history_skip_empty(s, s->history + s->start, 1);
1917 return ext4_mb_history_skip_empty(s, ++hs, 0);
1920 static int ext4_mb_seq_history_show(struct seq_file *seq, void *v)
1922 char buf[25], buf2[25], buf3[25], *fmt;
1923 struct ext4_mb_history *hs = v;
1925 if (v == SEQ_START_TOKEN) {
1926 seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s "
1927 "%-5s %-2s %-5s %-5s %-5s %-6s\n",
1928 "pid", "inode", "original", "goal", "result", "found",
1929 "grps", "cr", "flags", "merge", "tail", "broken");
1933 if (hs->op == EXT4_MB_HISTORY_ALLOC) {
1934 fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
1935 "%-5u %-5s %-5u %-6u\n";
1936 sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
1937 hs->result.fe_start, hs->result.fe_len,
1938 hs->result.fe_logical);
1939 sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
1940 hs->orig.fe_start, hs->orig.fe_len,
1941 hs->orig.fe_logical);
1942 sprintf(buf3, "%lu/%d/%u@%u", hs->goal.fe_group,
1943 hs->goal.fe_start, hs->goal.fe_len,
1944 hs->goal.fe_logical);
1945 seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2,
1946 hs->found, hs->groups, hs->cr, hs->flags,
1947 hs->merged ? "M" : "", hs->tail,
1948 hs->buddy ? 1 << hs->buddy : 0);
1949 } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) {
1950 fmt = "%-5u %-8u %-23s %-23s %-23s\n";
1951 sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
1952 hs->result.fe_start, hs->result.fe_len,
1953 hs->result.fe_logical);
1954 sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
1955 hs->orig.fe_start, hs->orig.fe_len,
1956 hs->orig.fe_logical);
1957 seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2);
1958 } else if (hs->op == EXT4_MB_HISTORY_DISCARD) {
1959 sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
1960 hs->result.fe_start, hs->result.fe_len);
1961 seq_printf(seq, "%-5u %-8u %-23s discard\n",
1962 hs->pid, hs->ino, buf2);
1963 } else if (hs->op == EXT4_MB_HISTORY_FREE) {
1964 sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
1965 hs->result.fe_start, hs->result.fe_len);
1966 seq_printf(seq, "%-5u %-8u %-23s free\n",
1967 hs->pid, hs->ino, buf2);
1972 static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v)
1976 static struct seq_operations ext4_mb_seq_history_ops = {
1977 .start = ext4_mb_seq_history_start,
1978 .next = ext4_mb_seq_history_next,
1979 .stop = ext4_mb_seq_history_stop,
1980 .show = ext4_mb_seq_history_show,
1983 static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
1985 struct super_block *sb = PDE(inode)->data;
1986 struct ext4_sb_info *sbi = EXT4_SB(sb);
1987 struct ext4_mb_proc_session *s;
1991 if (unlikely(sbi->s_mb_history == NULL))
1993 s = kmalloc(sizeof(*s), GFP_KERNEL);
1997 size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max;
1998 s->history = kmalloc(size, GFP_KERNEL);
1999 if (s->history == NULL) {
2004 spin_lock(&sbi->s_mb_history_lock);
2005 memcpy(s->history, sbi->s_mb_history, size);
2006 s->max = sbi->s_mb_history_max;
2007 s->start = sbi->s_mb_history_cur % s->max;
2008 spin_unlock(&sbi->s_mb_history_lock);
2010 rc = seq_open(file, &ext4_mb_seq_history_ops);
2012 struct seq_file *m = (struct seq_file *)file->private_data;
2022 static int ext4_mb_seq_history_release(struct inode *inode, struct file *file)
2024 struct seq_file *seq = (struct seq_file *)file->private_data;
2025 struct ext4_mb_proc_session *s = seq->private;
2028 return seq_release(inode, file);
2031 static ssize_t ext4_mb_seq_history_write(struct file *file,
2032 const char __user *buffer,
2033 size_t count, loff_t *ppos)
2035 struct seq_file *seq = (struct seq_file *)file->private_data;
2036 struct ext4_mb_proc_session *s = seq->private;
2037 struct super_block *sb = s->sb;
2041 if (count >= sizeof(str)) {
2042 printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n",
2043 "mb_history", (int)sizeof(str));
2047 if (copy_from_user(str, buffer, count))
2050 value = simple_strtol(str, NULL, 0);
2053 EXT4_SB(sb)->s_mb_history_filter = value;
2058 static struct file_operations ext4_mb_seq_history_fops = {
2059 .owner = THIS_MODULE,
2060 .open = ext4_mb_seq_history_open,
2062 .write = ext4_mb_seq_history_write,
2063 .llseek = seq_lseek,
2064 .release = ext4_mb_seq_history_release,
2067 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2069 struct super_block *sb = seq->private;
2070 struct ext4_sb_info *sbi = EXT4_SB(sb);
2073 if (*pos < 0 || *pos >= sbi->s_groups_count)
2077 return (void *) group;
2080 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2082 struct super_block *sb = seq->private;
2083 struct ext4_sb_info *sbi = EXT4_SB(sb);
2087 if (*pos < 0 || *pos >= sbi->s_groups_count)
2090 return (void *) group;;
2093 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2095 struct super_block *sb = seq->private;
2096 long group = (long) v;
2099 struct ext4_buddy e4b;
2101 struct ext4_group_info info;
2102 unsigned short counters[16];
2107 seq_printf(seq, "#%-5s: %-5s %-5s %-5s "
2108 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2109 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2110 "group", "free", "frags", "first",
2111 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2112 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2114 i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2115 sizeof(struct ext4_group_info);
2116 err = ext4_mb_load_buddy(sb, group, &e4b);
2118 seq_printf(seq, "#%-5lu: I/O error\n", group);
2121 ext4_lock_group(sb, group);
2122 memcpy(&sg, ext4_get_group_info(sb, group), i);
2123 ext4_unlock_group(sb, group);
2124 ext4_mb_release_desc(&e4b);
2126 seq_printf(seq, "#%-5lu: %-5u %-5u %-5u [", group, sg.info.bb_free,
2127 sg.info.bb_fragments, sg.info.bb_first_free);
2128 for (i = 0; i <= 13; i++)
2129 seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ?
2130 sg.info.bb_counters[i] : 0);
2131 seq_printf(seq, " ]\n");
2136 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2140 static struct seq_operations ext4_mb_seq_groups_ops = {
2141 .start = ext4_mb_seq_groups_start,
2142 .next = ext4_mb_seq_groups_next,
2143 .stop = ext4_mb_seq_groups_stop,
2144 .show = ext4_mb_seq_groups_show,
2147 static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
2149 struct super_block *sb = PDE(inode)->data;
2152 rc = seq_open(file, &ext4_mb_seq_groups_ops);
2154 struct seq_file *m = (struct seq_file *)file->private_data;
2161 static struct file_operations ext4_mb_seq_groups_fops = {
2162 .owner = THIS_MODULE,
2163 .open = ext4_mb_seq_groups_open,
2165 .llseek = seq_lseek,
2166 .release = seq_release,
2169 static void ext4_mb_history_release(struct super_block *sb)
2171 struct ext4_sb_info *sbi = EXT4_SB(sb);
2173 remove_proc_entry("mb_groups", sbi->s_mb_proc);
2174 remove_proc_entry("mb_history", sbi->s_mb_proc);
2176 kfree(sbi->s_mb_history);
2179 static void ext4_mb_history_init(struct super_block *sb)
2181 struct ext4_sb_info *sbi = EXT4_SB(sb);
2184 if (sbi->s_mb_proc != NULL) {
2185 proc_create_data("mb_history", S_IRUGO, sbi->s_mb_proc,
2186 &ext4_mb_seq_history_fops, sb);
2187 proc_create_data("mb_groups", S_IRUGO, sbi->s_mb_proc,
2188 &ext4_mb_seq_groups_fops, sb);
2191 sbi->s_mb_history_max = 1000;
2192 sbi->s_mb_history_cur = 0;
2193 spin_lock_init(&sbi->s_mb_history_lock);
2194 i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
2195 sbi->s_mb_history = kzalloc(i, GFP_KERNEL);
2196 /* if we can't allocate history, then we simple won't use it */
2199 static noinline_for_stack void
2200 ext4_mb_store_history(struct ext4_allocation_context *ac)
2202 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2203 struct ext4_mb_history h;
2205 if (unlikely(sbi->s_mb_history == NULL))
2208 if (!(ac->ac_op & sbi->s_mb_history_filter))
2212 h.pid = current->pid;
2213 h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
2214 h.orig = ac->ac_o_ex;
2215 h.result = ac->ac_b_ex;
2216 h.flags = ac->ac_flags;
2217 h.found = ac->ac_found;
2218 h.groups = ac->ac_groups_scanned;
2219 h.cr = ac->ac_criteria;
2220 h.tail = ac->ac_tail;
2221 h.buddy = ac->ac_buddy;
2223 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
2224 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
2225 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
2227 h.goal = ac->ac_g_ex;
2228 h.result = ac->ac_f_ex;
2231 spin_lock(&sbi->s_mb_history_lock);
2232 memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
2233 if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
2234 sbi->s_mb_history_cur = 0;
2235 spin_unlock(&sbi->s_mb_history_lock);
2239 #define ext4_mb_history_release(sb)
2240 #define ext4_mb_history_init(sb)
2244 /* Create and initialize ext4_group_info data for the given group. */
2245 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
2246 struct ext4_group_desc *desc)
2250 struct ext4_sb_info *sbi = EXT4_SB(sb);
2251 struct ext4_group_info **meta_group_info;
2254 * First check if this group is the first of a reserved block.
2255 * If it's true, we have to allocate a new table of pointers
2256 * to ext4_group_info structures
2258 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2259 metalen = sizeof(*meta_group_info) <<
2260 EXT4_DESC_PER_BLOCK_BITS(sb);
2261 meta_group_info = kmalloc(metalen, GFP_KERNEL);
2262 if (meta_group_info == NULL) {
2263 printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
2265 goto exit_meta_group_info;
2267 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] =
2272 * calculate needed size. if change bb_counters size,
2273 * don't forget about ext4_mb_generate_buddy()
2275 len = offsetof(typeof(**meta_group_info),
2276 bb_counters[sb->s_blocksize_bits + 2]);
2279 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
2280 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
2282 meta_group_info[i] = kzalloc(len, GFP_KERNEL);
2283 if (meta_group_info[i] == NULL) {
2284 printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
2285 goto exit_group_info;
2287 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2288 &(meta_group_info[i]->bb_state));
2291 * initialize bb_free to be able to skip
2292 * empty groups without initialization
2294 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2295 meta_group_info[i]->bb_free =
2296 ext4_free_blocks_after_init(sb, group, desc);
2298 meta_group_info[i]->bb_free =
2299 le16_to_cpu(desc->bg_free_blocks_count);
2302 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
2306 struct buffer_head *bh;
2307 meta_group_info[i]->bb_bitmap =
2308 kmalloc(sb->s_blocksize, GFP_KERNEL);
2309 BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
2310 bh = ext4_read_block_bitmap(sb, group);
2312 memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
2321 /* If a meta_group_info table has been allocated, release it now */
2322 if (group % EXT4_DESC_PER_BLOCK(sb) == 0)
2323 kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
2324 exit_meta_group_info:
2326 } /* ext4_mb_add_groupinfo */
2329 * Add a group to the existing groups.
2330 * This function is used for online resize
2332 int ext4_mb_add_more_groupinfo(struct super_block *sb, ext4_group_t group,
2333 struct ext4_group_desc *desc)
2335 struct ext4_sb_info *sbi = EXT4_SB(sb);
2336 struct inode *inode = sbi->s_buddy_cache;
2337 int blocks_per_page;
2343 /* Add group based on group descriptor*/
2344 err = ext4_mb_add_groupinfo(sb, group, desc);
2349 * Cache pages containing dynamic mb_alloc datas (buddy and bitmap
2350 * datas) are set not up to date so that they will be re-initilaized
2351 * during the next call to ext4_mb_load_buddy
2354 /* Set buddy page as not up to date */
2355 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
2357 pnum = block / blocks_per_page;
2358 page = find_get_page(inode->i_mapping, pnum);
2360 ClearPageUptodate(page);
2361 page_cache_release(page);
2364 /* Set bitmap page as not up to date */
2366 pnum = block / blocks_per_page;
2367 page = find_get_page(inode->i_mapping, pnum);
2369 ClearPageUptodate(page);
2370 page_cache_release(page);
2377 * Update an existing group.
2378 * This function is used for online resize
2380 void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add)
2382 grp->bb_free += add;
2385 static int ext4_mb_init_backend(struct super_block *sb)
2389 struct ext4_sb_info *sbi = EXT4_SB(sb);
2390 struct ext4_super_block *es = sbi->s_es;
2391 int num_meta_group_infos;
2392 int num_meta_group_infos_max;
2394 struct ext4_group_info **meta_group_info;
2395 struct ext4_group_desc *desc;
2397 /* This is the number of blocks used by GDT */
2398 num_meta_group_infos = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) -
2399 1) >> EXT4_DESC_PER_BLOCK_BITS(sb);
2402 * This is the total number of blocks used by GDT including
2403 * the number of reserved blocks for GDT.
2404 * The s_group_info array is allocated with this value
2405 * to allow a clean online resize without a complex
2406 * manipulation of pointer.
2407 * The drawback is the unused memory when no resize
2408 * occurs but it's very low in terms of pages
2409 * (see comments below)
2410 * Need to handle this properly when META_BG resizing is allowed
2412 num_meta_group_infos_max = num_meta_group_infos +
2413 le16_to_cpu(es->s_reserved_gdt_blocks);
2416 * array_size is the size of s_group_info array. We round it
2417 * to the next power of two because this approximation is done
2418 * internally by kmalloc so we can have some more memory
2419 * for free here (e.g. may be used for META_BG resize).
2422 while (array_size < sizeof(*sbi->s_group_info) *
2423 num_meta_group_infos_max)
2424 array_size = array_size << 1;
2425 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2426 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2427 * So a two level scheme suffices for now. */
2428 sbi->s_group_info = kmalloc(array_size, GFP_KERNEL);
2429 if (sbi->s_group_info == NULL) {
2430 printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
2433 sbi->s_buddy_cache = new_inode(sb);
2434 if (sbi->s_buddy_cache == NULL) {
2435 printk(KERN_ERR "EXT4-fs: can't get new inode\n");
2438 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2440 metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb);
2441 for (i = 0; i < num_meta_group_infos; i++) {
2442 if ((i + 1) == num_meta_group_infos)
2443 metalen = sizeof(*meta_group_info) *
2444 (sbi->s_groups_count -
2445 (i << EXT4_DESC_PER_BLOCK_BITS(sb)));
2446 meta_group_info = kmalloc(metalen, GFP_KERNEL);
2447 if (meta_group_info == NULL) {
2448 printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
2452 sbi->s_group_info[i] = meta_group_info;
2455 for (i = 0; i < sbi->s_groups_count; i++) {
2456 desc = ext4_get_group_desc(sb, i, NULL);
2459 "EXT4-fs: can't read descriptor %lu\n", i);
2462 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
2470 kfree(ext4_get_group_info(sb, i));
2471 i = num_meta_group_infos;
2474 kfree(sbi->s_group_info[i]);
2475 iput(sbi->s_buddy_cache);
2477 kfree(sbi->s_group_info);
2481 int ext4_mb_init(struct super_block *sb, int needs_recovery)
2483 struct ext4_sb_info *sbi = EXT4_SB(sb);
2489 if (!test_opt(sb, MBALLOC))
2492 i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
2494 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2495 if (sbi->s_mb_offsets == NULL) {
2496 clear_opt(sbi->s_mount_opt, MBALLOC);
2499 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2500 if (sbi->s_mb_maxs == NULL) {
2501 clear_opt(sbi->s_mount_opt, MBALLOC);
2502 kfree(sbi->s_mb_maxs);
2506 /* order 0 is regular bitmap */
2507 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2508 sbi->s_mb_offsets[0] = 0;
2512 max = sb->s_blocksize << 2;
2514 sbi->s_mb_offsets[i] = offset;
2515 sbi->s_mb_maxs[i] = max;
2516 offset += 1 << (sb->s_blocksize_bits - i);
2519 } while (i <= sb->s_blocksize_bits + 1);
2521 /* init file for buddy data */
2522 ret = ext4_mb_init_backend(sb);
2524 clear_opt(sbi->s_mount_opt, MBALLOC);
2525 kfree(sbi->s_mb_offsets);
2526 kfree(sbi->s_mb_maxs);
2530 spin_lock_init(&sbi->s_md_lock);
2531 INIT_LIST_HEAD(&sbi->s_active_transaction);
2532 INIT_LIST_HEAD(&sbi->s_closed_transaction);
2533 INIT_LIST_HEAD(&sbi->s_committed_transaction);
2534 spin_lock_init(&sbi->s_bal_lock);
2536 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2537 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2538 sbi->s_mb_stats = MB_DEFAULT_STATS;
2539 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2540 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2541 sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
2542 sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
2544 i = sizeof(struct ext4_locality_group) * nr_cpu_ids;
2545 sbi->s_locality_groups = kmalloc(i, GFP_KERNEL);
2546 if (sbi->s_locality_groups == NULL) {
2547 clear_opt(sbi->s_mount_opt, MBALLOC);
2548 kfree(sbi->s_mb_offsets);
2549 kfree(sbi->s_mb_maxs);
2552 for (i = 0; i < nr_cpu_ids; i++) {
2553 struct ext4_locality_group *lg;
2554 lg = &sbi->s_locality_groups[i];
2555 mutex_init(&lg->lg_mutex);
2556 for (j = 0; j < PREALLOC_TB_SIZE; j++)
2557 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
2558 spin_lock_init(&lg->lg_prealloc_lock);
2561 ext4_mb_init_per_dev_proc(sb);
2562 ext4_mb_history_init(sb);
2564 printk(KERN_INFO "EXT4-fs: mballoc enabled\n");
2568 /* need to called with ext4 group lock (ext4_lock_group) */
2569 static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2571 struct ext4_prealloc_space *pa;
2572 struct list_head *cur, *tmp;
2575 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2576 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2577 list_del(&pa->pa_group_list);
2582 mb_debug("mballoc: %u PAs left\n", count);
2586 int ext4_mb_release(struct super_block *sb)
2589 int num_meta_group_infos;
2590 struct ext4_group_info *grinfo;
2591 struct ext4_sb_info *sbi = EXT4_SB(sb);
2593 if (!test_opt(sb, MBALLOC))
2596 /* release freed, non-committed blocks */
2597 spin_lock(&sbi->s_md_lock);
2598 list_splice_init(&sbi->s_closed_transaction,
2599 &sbi->s_committed_transaction);
2600 list_splice_init(&sbi->s_active_transaction,
2601 &sbi->s_committed_transaction);
2602 spin_unlock(&sbi->s_md_lock);
2603 ext4_mb_free_committed_blocks(sb);
2605 if (sbi->s_group_info) {
2606 for (i = 0; i < sbi->s_groups_count; i++) {
2607 grinfo = ext4_get_group_info(sb, i);
2609 kfree(grinfo->bb_bitmap);
2611 ext4_lock_group(sb, i);
2612 ext4_mb_cleanup_pa(grinfo);
2613 ext4_unlock_group(sb, i);
2616 num_meta_group_infos = (sbi->s_groups_count +
2617 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2618 EXT4_DESC_PER_BLOCK_BITS(sb);
2619 for (i = 0; i < num_meta_group_infos; i++)
2620 kfree(sbi->s_group_info[i]);
2621 kfree(sbi->s_group_info);
2623 kfree(sbi->s_mb_offsets);
2624 kfree(sbi->s_mb_maxs);
2625 if (sbi->s_buddy_cache)
2626 iput(sbi->s_buddy_cache);
2627 if (sbi->s_mb_stats) {
2629 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2630 atomic_read(&sbi->s_bal_allocated),
2631 atomic_read(&sbi->s_bal_reqs),
2632 atomic_read(&sbi->s_bal_success));
2634 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2635 "%u 2^N hits, %u breaks, %u lost\n",
2636 atomic_read(&sbi->s_bal_ex_scanned),
2637 atomic_read(&sbi->s_bal_goals),
2638 atomic_read(&sbi->s_bal_2orders),
2639 atomic_read(&sbi->s_bal_breaks),
2640 atomic_read(&sbi->s_mb_lost_chunks));
2642 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2643 sbi->s_mb_buddies_generated++,
2644 sbi->s_mb_generation_time);
2646 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2647 atomic_read(&sbi->s_mb_preallocated),
2648 atomic_read(&sbi->s_mb_discarded));
2651 kfree(sbi->s_locality_groups);
2653 ext4_mb_history_release(sb);
2654 ext4_mb_destroy_per_dev_proc(sb);
2659 static noinline_for_stack void
2660 ext4_mb_free_committed_blocks(struct super_block *sb)
2662 struct ext4_sb_info *sbi = EXT4_SB(sb);
2667 struct ext4_free_metadata *md;
2668 struct ext4_buddy e4b;
2670 if (list_empty(&sbi->s_committed_transaction))
2673 /* there is committed blocks to be freed yet */
2675 /* get next array of blocks */
2677 spin_lock(&sbi->s_md_lock);
2678 if (!list_empty(&sbi->s_committed_transaction)) {
2679 md = list_entry(sbi->s_committed_transaction.next,
2680 struct ext4_free_metadata, list);
2681 list_del(&md->list);
2683 spin_unlock(&sbi->s_md_lock);
2688 mb_debug("gonna free %u blocks in group %lu (0x%p):",
2689 md->num, md->group, md);
2691 err = ext4_mb_load_buddy(sb, md->group, &e4b);
2692 /* we expect to find existing buddy because it's pinned */
2695 /* there are blocks to put in buddy to make them really free */
2698 ext4_lock_group(sb, md->group);
2699 for (i = 0; i < md->num; i++) {
2700 mb_debug(" %u", md->blocks[i]);
2701 mb_free_blocks(NULL, &e4b, md->blocks[i], 1);
2704 ext4_unlock_group(sb, md->group);
2706 /* balance refcounts from ext4_mb_free_metadata() */
2707 page_cache_release(e4b.bd_buddy_page);
2708 page_cache_release(e4b.bd_bitmap_page);
2711 ext4_mb_release_desc(&e4b);
2715 mb_debug("freed %u blocks in %u structures\n", count, count2);
2718 #define EXT4_MB_STATS_NAME "stats"
2719 #define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
2720 #define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
2721 #define EXT4_MB_ORDER2_REQ "order2_req"
2722 #define EXT4_MB_STREAM_REQ "stream_req"
2723 #define EXT4_MB_GROUP_PREALLOC "group_prealloc"
2727 #define MB_PROC_FOPS(name) \
2728 static int ext4_mb_##name##_proc_show(struct seq_file *m, void *v) \
2730 struct ext4_sb_info *sbi = m->private; \
2732 seq_printf(m, "%ld\n", sbi->s_mb_##name); \
2736 static int ext4_mb_##name##_proc_open(struct inode *inode, struct file *file)\
2738 return single_open(file, ext4_mb_##name##_proc_show, PDE(inode)->data);\
2741 static ssize_t ext4_mb_##name##_proc_write(struct file *file, \
2742 const char __user *buf, size_t cnt, loff_t *ppos) \
2744 struct ext4_sb_info *sbi = PDE(file->f_path.dentry->d_inode)->data;\
2747 if (cnt >= sizeof(str)) \
2749 if (copy_from_user(str, buf, cnt)) \
2751 value = simple_strtol(str, NULL, 0); \
2754 sbi->s_mb_##name = value; \
2758 static const struct file_operations ext4_mb_##name##_proc_fops = { \
2759 .owner = THIS_MODULE, \
2760 .open = ext4_mb_##name##_proc_open, \
2762 .llseek = seq_lseek, \
2763 .release = single_release, \
2764 .write = ext4_mb_##name##_proc_write, \
2767 MB_PROC_FOPS(stats);
2768 MB_PROC_FOPS(max_to_scan);
2769 MB_PROC_FOPS(min_to_scan);
2770 MB_PROC_FOPS(order2_reqs);
2771 MB_PROC_FOPS(stream_request);
2772 MB_PROC_FOPS(group_prealloc);
2774 #define MB_PROC_HANDLER(name, var) \
2776 proc = proc_create_data(name, mode, sbi->s_mb_proc, \
2777 &ext4_mb_##var##_proc_fops, sbi); \
2778 if (proc == NULL) { \
2779 printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
2784 static int ext4_mb_init_per_dev_proc(struct super_block *sb)
2786 mode_t mode = S_IFREG | S_IRUGO | S_IWUSR;
2787 struct ext4_sb_info *sbi = EXT4_SB(sb);
2788 struct proc_dir_entry *proc;
2791 if (proc_root_ext4 == NULL) {
2792 sbi->s_mb_proc = NULL;
2795 bdevname(sb->s_bdev, devname);
2796 sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);
2798 MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats);
2799 MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan);
2800 MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, min_to_scan);
2801 MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ, order2_reqs);
2802 MB_PROC_HANDLER(EXT4_MB_STREAM_REQ, stream_request);
2803 MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, group_prealloc);
2808 printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname);
2809 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
2810 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
2811 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
2812 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
2813 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
2814 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
2815 remove_proc_entry(devname, proc_root_ext4);
2816 sbi->s_mb_proc = NULL;
2821 static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)
2823 struct ext4_sb_info *sbi = EXT4_SB(sb);
2826 if (sbi->s_mb_proc == NULL)
2829 bdevname(sb->s_bdev, devname);
2830 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
2831 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
2832 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
2833 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
2834 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
2835 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
2836 remove_proc_entry(devname, proc_root_ext4);
2841 int __init init_ext4_mballoc(void)
2843 ext4_pspace_cachep =
2844 kmem_cache_create("ext4_prealloc_space",
2845 sizeof(struct ext4_prealloc_space),
2846 0, SLAB_RECLAIM_ACCOUNT, NULL);
2847 if (ext4_pspace_cachep == NULL)
2851 kmem_cache_create("ext4_alloc_context",
2852 sizeof(struct ext4_allocation_context),
2853 0, SLAB_RECLAIM_ACCOUNT, NULL);
2854 if (ext4_ac_cachep == NULL) {
2855 kmem_cache_destroy(ext4_pspace_cachep);
2858 #ifdef CONFIG_PROC_FS
2859 proc_root_ext4 = proc_mkdir("fs/ext4", NULL);
2860 if (proc_root_ext4 == NULL)
2861 printk(KERN_ERR "EXT4-fs: Unable to create fs/ext4\n");
2866 void exit_ext4_mballoc(void)
2868 /* XXX: synchronize_rcu(); */
2869 kmem_cache_destroy(ext4_pspace_cachep);
2870 kmem_cache_destroy(ext4_ac_cachep);
2871 #ifdef CONFIG_PROC_FS
2872 remove_proc_entry("fs/ext4", NULL);
2878 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
2879 * Returns 0 if success or error code
2881 static noinline_for_stack int
2882 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
2885 struct buffer_head *bitmap_bh = NULL;
2886 struct ext4_super_block *es;
2887 struct ext4_group_desc *gdp;
2888 struct buffer_head *gdp_bh;
2889 struct ext4_sb_info *sbi;
2890 struct super_block *sb;
2894 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
2895 BUG_ON(ac->ac_b_ex.fe_len <= 0);
2903 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
2907 err = ext4_journal_get_write_access(handle, bitmap_bh);
2912 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
2916 ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group,
2917 gdp->bg_free_blocks_count);
2919 err = ext4_journal_get_write_access(handle, gdp_bh);
2923 block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb)
2924 + ac->ac_b_ex.fe_start
2925 + le32_to_cpu(es->s_first_data_block);
2927 len = ac->ac_b_ex.fe_len;
2928 if (in_range(ext4_block_bitmap(sb, gdp), block, len) ||
2929 in_range(ext4_inode_bitmap(sb, gdp), block, len) ||
2930 in_range(block, ext4_inode_table(sb, gdp),
2931 EXT4_SB(sb)->s_itb_per_group) ||
2932 in_range(block + len - 1, ext4_inode_table(sb, gdp),
2933 EXT4_SB(sb)->s_itb_per_group)) {
2934 ext4_error(sb, __func__,
2935 "Allocating block in system zone - block = %llu",
2937 /* File system mounted not to panic on error
2938 * Fix the bitmap and repeat the block allocation
2939 * We leak some of the blocks here.
2941 mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group),
2942 bitmap_bh->b_data, ac->ac_b_ex.fe_start,
2943 ac->ac_b_ex.fe_len);
2944 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
2949 #ifdef AGGRESSIVE_CHECK
2952 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
2953 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
2954 bitmap_bh->b_data));
2958 mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data,
2959 ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
2961 spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
2962 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2963 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
2964 gdp->bg_free_blocks_count =
2965 cpu_to_le16(ext4_free_blocks_after_init(sb,
2966 ac->ac_b_ex.fe_group,
2969 le16_add_cpu(&gdp->bg_free_blocks_count, -ac->ac_b_ex.fe_len);
2970 gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
2971 spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
2974 * free blocks account has already be reduced/reserved
2975 * at write_begin() time for delayed allocation
2976 * do not double accounting
2978 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED) &&
2979 ac->ac_o_ex.fe_len != ac->ac_b_ex.fe_len) {
2981 * we allocated less blocks than we calimed
2982 * Add the difference back
2984 percpu_counter_add(&sbi->s_freeblocks_counter,
2985 ac->ac_o_ex.fe_len - ac->ac_b_ex.fe_len);
2988 if (sbi->s_log_groups_per_flex) {
2989 ext4_group_t flex_group = ext4_flex_group(sbi,
2990 ac->ac_b_ex.fe_group);
2991 spin_lock(sb_bgl_lock(sbi, flex_group));
2992 sbi->s_flex_groups[flex_group].free_blocks -= ac->ac_b_ex.fe_len;
2993 spin_unlock(sb_bgl_lock(sbi, flex_group));
2996 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
2999 err = ext4_journal_dirty_metadata(handle, gdp_bh);
3008 * here we normalize request for locality group
3009 * Group request are normalized to s_strip size if we set the same via mount
3010 * option. If not we set it to s_mb_group_prealloc which can be configured via
3011 * /proc/fs/ext4/<partition>/group_prealloc
3013 * XXX: should we try to preallocate more than the group has now?
3015 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3017 struct super_block *sb = ac->ac_sb;
3018 struct ext4_locality_group *lg = ac->ac_lg;
3021 if (EXT4_SB(sb)->s_stripe)
3022 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe;
3024 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3025 mb_debug("#%u: goal %u blocks for locality group\n",
3026 current->pid, ac->ac_g_ex.fe_len);
3030 * Normalization means making request better in terms of
3031 * size and alignment
3033 static noinline_for_stack void
3034 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
3035 struct ext4_allocation_request *ar)
3039 loff_t size, orig_size, start_off;
3040 ext4_lblk_t start, orig_start;
3041 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3042 struct ext4_prealloc_space *pa;
3044 /* do normalize only data requests, metadata requests
3045 do not need preallocation */
3046 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3049 /* sometime caller may want exact blocks */
3050 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3053 /* caller may indicate that preallocation isn't
3054 * required (it's a tail, for example) */
3055 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3058 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3059 ext4_mb_normalize_group_request(ac);
3063 bsbits = ac->ac_sb->s_blocksize_bits;
3065 /* first, let's learn actual file size
3066 * given current request is allocated */
3067 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
3068 size = size << bsbits;
3069 if (size < i_size_read(ac->ac_inode))
3070 size = i_size_read(ac->ac_inode);
3072 /* max size of free chunks */
3075 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3076 (req <= (size) || max <= (chunk_size))
3078 /* first, try to predict filesize */
3079 /* XXX: should this table be tunable? */
3081 if (size <= 16 * 1024) {
3083 } else if (size <= 32 * 1024) {
3085 } else if (size <= 64 * 1024) {
3087 } else if (size <= 128 * 1024) {
3089 } else if (size <= 256 * 1024) {
3091 } else if (size <= 512 * 1024) {
3093 } else if (size <= 1024 * 1024) {
3095 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
3096 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3097 (21 - bsbits)) << 21;
3098 size = 2 * 1024 * 1024;
3099 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
3100 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3101 (22 - bsbits)) << 22;
3102 size = 4 * 1024 * 1024;
3103 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3104 (8<<20)>>bsbits, max, 8 * 1024)) {
3105 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3106 (23 - bsbits)) << 23;
3107 size = 8 * 1024 * 1024;
3109 start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
3110 size = ac->ac_o_ex.fe_len << bsbits;
3112 orig_size = size = size >> bsbits;
3113 orig_start = start = start_off >> bsbits;
3115 /* don't cover already allocated blocks in selected range */
3116 if (ar->pleft && start <= ar->lleft) {
3117 size -= ar->lleft + 1 - start;
3118 start = ar->lleft + 1;
3120 if (ar->pright && start + size - 1 >= ar->lright)
3121 size -= start + size - ar->lright;
3125 /* check we don't cross already preallocated blocks */
3127 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3128 unsigned long pa_end;
3132 spin_lock(&pa->pa_lock);
3133 if (pa->pa_deleted) {
3134 spin_unlock(&pa->pa_lock);
3138 pa_end = pa->pa_lstart + pa->pa_len;
3140 /* PA must not overlap original request */
3141 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3142 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3144 /* skip PA normalized request doesn't overlap with */
3145 if (pa->pa_lstart >= end) {
3146 spin_unlock(&pa->pa_lock);
3149 if (pa_end <= start) {
3150 spin_unlock(&pa->pa_lock);
3153 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3155 if (pa_end <= ac->ac_o_ex.fe_logical) {
3156 BUG_ON(pa_end < start);
3160 if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3161 BUG_ON(pa->pa_lstart > end);
3162 end = pa->pa_lstart;
3164 spin_unlock(&pa->pa_lock);
3169 /* XXX: extra loop to check we really don't overlap preallocations */
3171 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3172 unsigned long pa_end;
3173 spin_lock(&pa->pa_lock);
3174 if (pa->pa_deleted == 0) {
3175 pa_end = pa->pa_lstart + pa->pa_len;
3176 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3178 spin_unlock(&pa->pa_lock);
3182 if (start + size <= ac->ac_o_ex.fe_logical &&
3183 start > ac->ac_o_ex.fe_logical) {
3184 printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n",
3185 (unsigned long) start, (unsigned long) size,
3186 (unsigned long) ac->ac_o_ex.fe_logical);
3188 BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
3189 start > ac->ac_o_ex.fe_logical);
3190 BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3192 /* now prepare goal request */
3194 /* XXX: is it better to align blocks WRT to logical
3195 * placement or satisfy big request as is */
3196 ac->ac_g_ex.fe_logical = start;
3197 ac->ac_g_ex.fe_len = size;
3199 /* define goal start in order to merge */
3200 if (ar->pright && (ar->lright == (start + size))) {
3201 /* merge to the right */
3202 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3203 &ac->ac_f_ex.fe_group,
3204 &ac->ac_f_ex.fe_start);
3205 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3207 if (ar->pleft && (ar->lleft + 1 == start)) {
3208 /* merge to the left */
3209 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3210 &ac->ac_f_ex.fe_group,
3211 &ac->ac_f_ex.fe_start);
3212 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3215 mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size,
3216 (unsigned) orig_size, (unsigned) start);
3219 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3221 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3223 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3224 atomic_inc(&sbi->s_bal_reqs);
3225 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3226 if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
3227 atomic_inc(&sbi->s_bal_success);
3228 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3229 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3230 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3231 atomic_inc(&sbi->s_bal_goals);
3232 if (ac->ac_found > sbi->s_mb_max_to_scan)
3233 atomic_inc(&sbi->s_bal_breaks);
3236 ext4_mb_store_history(ac);
3240 * use blocks preallocated to inode
3242 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3243 struct ext4_prealloc_space *pa)
3249 /* found preallocated blocks, use them */
3250 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3251 end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len);
3253 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3254 &ac->ac_b_ex.fe_start);
3255 ac->ac_b_ex.fe_len = len;
3256 ac->ac_status = AC_STATUS_FOUND;
3259 BUG_ON(start < pa->pa_pstart);
3260 BUG_ON(start + len > pa->pa_pstart + pa->pa_len);
3261 BUG_ON(pa->pa_free < len);
3264 mb_debug("use %llu/%u from inode pa %p\n", start, len, pa);
3268 * use blocks preallocated to locality group
3270 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3271 struct ext4_prealloc_space *pa)
3273 unsigned int len = ac->ac_o_ex.fe_len;
3275 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3276 &ac->ac_b_ex.fe_group,
3277 &ac->ac_b_ex.fe_start);
3278 ac->ac_b_ex.fe_len = len;
3279 ac->ac_status = AC_STATUS_FOUND;
3282 /* we don't correct pa_pstart or pa_plen here to avoid
3283 * possible race when the group is being loaded concurrently
3284 * instead we correct pa later, after blocks are marked
3285 * in on-disk bitmap -- see ext4_mb_release_context()
3286 * Other CPUs are prevented from allocating from this pa by lg_mutex
3288 mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3292 * Return the prealloc space that have minimal distance
3293 * from the goal block. @cpa is the prealloc
3294 * space that is having currently known minimal distance
3295 * from the goal block.
3297 static struct ext4_prealloc_space *
3298 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
3299 struct ext4_prealloc_space *pa,
3300 struct ext4_prealloc_space *cpa)
3302 ext4_fsblk_t cur_distance, new_distance;
3305 atomic_inc(&pa->pa_count);
3308 cur_distance = abs(goal_block - cpa->pa_pstart);
3309 new_distance = abs(goal_block - pa->pa_pstart);
3311 if (cur_distance < new_distance)
3314 /* drop the previous reference */
3315 atomic_dec(&cpa->pa_count);
3316 atomic_inc(&pa->pa_count);
3321 * search goal blocks in preallocated space
3323 static noinline_for_stack int
3324 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
3327 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3328 struct ext4_locality_group *lg;
3329 struct ext4_prealloc_space *pa, *cpa = NULL;
3330 ext4_fsblk_t goal_block;
3332 /* only data can be preallocated */
3333 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3336 /* first, try per-file preallocation */
3338 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3340 /* all fields in this condition don't change,
3341 * so we can skip locking for them */
3342 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3343 ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len)
3346 /* found preallocated blocks, use them */
3347 spin_lock(&pa->pa_lock);
3348 if (pa->pa_deleted == 0 && pa->pa_free) {
3349 atomic_inc(&pa->pa_count);
3350 ext4_mb_use_inode_pa(ac, pa);
3351 spin_unlock(&pa->pa_lock);
3352 ac->ac_criteria = 10;
3356 spin_unlock(&pa->pa_lock);
3360 /* can we use group allocation? */
3361 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3364 /* inode may have no locality group for some reason */
3368 order = fls(ac->ac_o_ex.fe_len) - 1;
3369 if (order > PREALLOC_TB_SIZE - 1)
3370 /* The max size of hash table is PREALLOC_TB_SIZE */
3371 order = PREALLOC_TB_SIZE - 1;
3373 goal_block = ac->ac_g_ex.fe_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb) +
3374 ac->ac_g_ex.fe_start +
3375 le32_to_cpu(EXT4_SB(ac->ac_sb)->s_es->s_first_data_block);
3377 * search for the prealloc space that is having
3378 * minimal distance from the goal block.
3380 for (i = order; i < PREALLOC_TB_SIZE; i++) {
3382 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
3384 spin_lock(&pa->pa_lock);
3385 if (pa->pa_deleted == 0 &&
3386 pa->pa_free >= ac->ac_o_ex.fe_len) {
3388 cpa = ext4_mb_check_group_pa(goal_block,
3391 spin_unlock(&pa->pa_lock);
3396 ext4_mb_use_group_pa(ac, cpa);
3397 ac->ac_criteria = 20;
3404 * the function goes through all preallocation in this group and marks them
3405 * used in in-core bitmap. buddy must be generated from this bitmap
3406 * Need to be called with ext4 group lock (ext4_lock_group)
3408 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3411 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3412 struct ext4_prealloc_space *pa;
3413 struct list_head *cur;
3414 ext4_group_t groupnr;
3415 ext4_grpblk_t start;
3416 int preallocated = 0;
3420 /* all form of preallocation discards first load group,
3421 * so the only competing code is preallocation use.
3422 * we don't need any locking here
3423 * notice we do NOT ignore preallocations with pa_deleted
3424 * otherwise we could leave used blocks available for
3425 * allocation in buddy when concurrent ext4_mb_put_pa()
3426 * is dropping preallocation
3428 list_for_each(cur, &grp->bb_prealloc_list) {
3429 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3430 spin_lock(&pa->pa_lock);
3431 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3434 spin_unlock(&pa->pa_lock);
3435 if (unlikely(len == 0))
3437 BUG_ON(groupnr != group);
3438 mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
3439 bitmap, start, len);
3440 preallocated += len;
3443 mb_debug("prellocated %u for group %lu\n", preallocated, group);
3446 static void ext4_mb_pa_callback(struct rcu_head *head)
3448 struct ext4_prealloc_space *pa;
3449 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3450 kmem_cache_free(ext4_pspace_cachep, pa);
3454 * drops a reference to preallocated space descriptor
3455 * if this was the last reference and the space is consumed
3457 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3458 struct super_block *sb, struct ext4_prealloc_space *pa)
3462 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0)
3465 /* in this short window concurrent discard can set pa_deleted */
3466 spin_lock(&pa->pa_lock);
3467 if (pa->pa_deleted == 1) {
3468 spin_unlock(&pa->pa_lock);
3473 spin_unlock(&pa->pa_lock);
3475 /* -1 is to protect from crossing allocation group */
3476 ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL);
3481 * P1 (buddy init) P2 (regular allocation)
3482 * find block B in PA
3483 * copy on-disk bitmap to buddy
3484 * mark B in on-disk bitmap
3485 * drop PA from group
3486 * mark all PAs in buddy
3488 * thus, P1 initializes buddy with B available. to prevent this
3489 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3492 ext4_lock_group(sb, grp);
3493 list_del(&pa->pa_group_list);
3494 ext4_unlock_group(sb, grp);
3496 spin_lock(pa->pa_obj_lock);
3497 list_del_rcu(&pa->pa_inode_list);
3498 spin_unlock(pa->pa_obj_lock);
3500 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3504 * creates new preallocated space for given inode
3506 static noinline_for_stack int
3507 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
3509 struct super_block *sb = ac->ac_sb;
3510 struct ext4_prealloc_space *pa;
3511 struct ext4_group_info *grp;
3512 struct ext4_inode_info *ei;
3514 /* preallocate only when found space is larger then requested */
3515 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3516 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3517 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3519 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3523 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3529 /* we can't allocate as much as normalizer wants.
3530 * so, found space must get proper lstart
3531 * to cover original request */
3532 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3533 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3535 /* we're limited by original request in that
3536 * logical block must be covered any way
3537 * winl is window we can move our chunk within */
3538 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
3540 /* also, we should cover whole original request */
3541 wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len;
3543 /* the smallest one defines real window */
3544 win = min(winl, wins);
3546 offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len;
3547 if (offs && offs < win)
3550 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win;
3551 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3552 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3555 /* preallocation can change ac_b_ex, thus we store actually
3556 * allocated blocks for history */
3557 ac->ac_f_ex = ac->ac_b_ex;
3559 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3560 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3561 pa->pa_len = ac->ac_b_ex.fe_len;
3562 pa->pa_free = pa->pa_len;
3563 atomic_set(&pa->pa_count, 1);
3564 spin_lock_init(&pa->pa_lock);
3568 mb_debug("new inode pa %p: %llu/%u for %u\n", pa,
3569 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3571 ext4_mb_use_inode_pa(ac, pa);
3572 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3574 ei = EXT4_I(ac->ac_inode);
3575 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3577 pa->pa_obj_lock = &ei->i_prealloc_lock;
3578 pa->pa_inode = ac->ac_inode;
3580 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3581 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3582 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3584 spin_lock(pa->pa_obj_lock);
3585 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3586 spin_unlock(pa->pa_obj_lock);
3592 * creates new preallocated space for locality group inodes belongs to
3594 static noinline_for_stack int
3595 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
3597 struct super_block *sb = ac->ac_sb;
3598 struct ext4_locality_group *lg;
3599 struct ext4_prealloc_space *pa;
3600 struct ext4_group_info *grp;
3602 /* preallocate only when found space is larger then requested */
3603 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3604 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3605 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3607 BUG_ON(ext4_pspace_cachep == NULL);
3608 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3612 /* preallocation can change ac_b_ex, thus we store actually
3613 * allocated blocks for history */
3614 ac->ac_f_ex = ac->ac_b_ex;
3616 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3617 pa->pa_lstart = pa->pa_pstart;
3618 pa->pa_len = ac->ac_b_ex.fe_len;
3619 pa->pa_free = pa->pa_len;
3620 atomic_set(&pa->pa_count, 1);
3621 spin_lock_init(&pa->pa_lock);
3622 INIT_LIST_HEAD(&pa->pa_inode_list);
3626 mb_debug("new group pa %p: %llu/%u for %u\n", pa,
3627 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3629 ext4_mb_use_group_pa(ac, pa);
3630 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3632 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3636 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3637 pa->pa_inode = NULL;
3639 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3640 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3641 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3644 * We will later add the new pa to the right bucket
3645 * after updating the pa_free in ext4_mb_release_context
3650 static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3654 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3655 err = ext4_mb_new_group_pa(ac);
3657 err = ext4_mb_new_inode_pa(ac);
3662 * finds all unused blocks in on-disk bitmap, frees them in
3663 * in-core bitmap and buddy.
3664 * @pa must be unlinked from inode and group lists, so that
3665 * nobody else can find/use it.
3666 * the caller MUST hold group/inode locks.
3667 * TODO: optimize the case when there are no in-core structures yet
3669 static noinline_for_stack int
3670 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
3671 struct ext4_prealloc_space *pa,
3672 struct ext4_allocation_context *ac)
3674 struct super_block *sb = e4b->bd_sb;
3675 struct ext4_sb_info *sbi = EXT4_SB(sb);
3684 BUG_ON(pa->pa_deleted == 0);
3685 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3686 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3687 end = bit + pa->pa_len;
3691 ac->ac_inode = pa->pa_inode;
3692 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
3696 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
3699 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
3700 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
3701 le32_to_cpu(sbi->s_es->s_first_data_block);
3702 mb_debug(" free preallocated %u/%u in group %u\n",
3703 (unsigned) start, (unsigned) next - bit,
3708 ac->ac_b_ex.fe_group = group;
3709 ac->ac_b_ex.fe_start = bit;
3710 ac->ac_b_ex.fe_len = next - bit;
3711 ac->ac_b_ex.fe_logical = 0;
3712 ext4_mb_store_history(ac);
3715 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3718 if (free != pa->pa_free) {
3719 printk(KERN_CRIT "pa %p: logic %lu, phys. %lu, len %lu\n",
3720 pa, (unsigned long) pa->pa_lstart,
3721 (unsigned long) pa->pa_pstart,
3722 (unsigned long) pa->pa_len);
3723 ext4_error(sb, __func__, "free %u, pa_free %u\n",
3726 * pa is already deleted so we use the value obtained
3727 * from the bitmap and continue.
3730 atomic_add(free, &sbi->s_mb_discarded);
3735 static noinline_for_stack int
3736 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
3737 struct ext4_prealloc_space *pa,
3738 struct ext4_allocation_context *ac)
3740 struct super_block *sb = e4b->bd_sb;
3745 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
3747 BUG_ON(pa->pa_deleted == 0);
3748 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3749 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3750 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3751 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3755 ac->ac_inode = NULL;
3756 ac->ac_b_ex.fe_group = group;
3757 ac->ac_b_ex.fe_start = bit;
3758 ac->ac_b_ex.fe_len = pa->pa_len;
3759 ac->ac_b_ex.fe_logical = 0;
3760 ext4_mb_store_history(ac);
3767 * releases all preallocations in given group
3769 * first, we need to decide discard policy:
3770 * - when do we discard
3772 * - how many do we discard
3773 * 1) how many requested
3775 static noinline_for_stack int
3776 ext4_mb_discard_group_preallocations(struct super_block *sb,
3777 ext4_group_t group, int needed)
3779 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3780 struct buffer_head *bitmap_bh = NULL;
3781 struct ext4_prealloc_space *pa, *tmp;
3782 struct ext4_allocation_context *ac;
3783 struct list_head list;
3784 struct ext4_buddy e4b;
3789 mb_debug("discard preallocation for group %lu\n", group);
3791 if (list_empty(&grp->bb_prealloc_list))
3794 bitmap_bh = ext4_read_block_bitmap(sb, group);
3795 if (bitmap_bh == NULL) {
3796 ext4_error(sb, __func__, "Error in reading block "
3797 "bitmap for %lu\n", group);
3801 err = ext4_mb_load_buddy(sb, group, &e4b);
3803 ext4_error(sb, __func__, "Error in loading buddy "
3804 "information for %lu\n", group);
3810 needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
3812 INIT_LIST_HEAD(&list);
3813 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
3815 ext4_lock_group(sb, group);
3816 list_for_each_entry_safe(pa, tmp,
3817 &grp->bb_prealloc_list, pa_group_list) {
3818 spin_lock(&pa->pa_lock);
3819 if (atomic_read(&pa->pa_count)) {
3820 spin_unlock(&pa->pa_lock);
3824 if (pa->pa_deleted) {
3825 spin_unlock(&pa->pa_lock);
3829 /* seems this one can be freed ... */
3832 /* we can trust pa_free ... */
3833 free += pa->pa_free;
3835 spin_unlock(&pa->pa_lock);
3837 list_del(&pa->pa_group_list);
3838 list_add(&pa->u.pa_tmp_list, &list);
3841 /* if we still need more blocks and some PAs were used, try again */
3842 if (free < needed && busy) {
3844 ext4_unlock_group(sb, group);
3846 * Yield the CPU here so that we don't get soft lockup
3847 * in non preempt case.
3853 /* found anything to free? */
3854 if (list_empty(&list)) {
3859 /* now free all selected PAs */
3860 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3862 /* remove from object (inode or locality group) */
3863 spin_lock(pa->pa_obj_lock);
3864 list_del_rcu(&pa->pa_inode_list);
3865 spin_unlock(pa->pa_obj_lock);
3868 ext4_mb_release_group_pa(&e4b, pa, ac);
3870 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);
3872 list_del(&pa->u.pa_tmp_list);
3873 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3877 ext4_unlock_group(sb, group);
3879 kmem_cache_free(ext4_ac_cachep, ac);
3880 ext4_mb_release_desc(&e4b);
3886 * releases all non-used preallocated blocks for given inode
3888 * It's important to discard preallocations under i_data_sem
3889 * We don't want another block to be served from the prealloc
3890 * space when we are discarding the inode prealloc space.
3892 * FIXME!! Make sure it is valid at all the call sites
3894 void ext4_mb_discard_inode_preallocations(struct inode *inode)
3896 struct ext4_inode_info *ei = EXT4_I(inode);
3897 struct super_block *sb = inode->i_sb;
3898 struct buffer_head *bitmap_bh = NULL;
3899 struct ext4_prealloc_space *pa, *tmp;
3900 struct ext4_allocation_context *ac;
3901 ext4_group_t group = 0;
3902 struct list_head list;
3903 struct ext4_buddy e4b;
3906 if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) {
3907 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3911 mb_debug("discard preallocation for inode %lu\n", inode->i_ino);
3913 INIT_LIST_HEAD(&list);
3915 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
3917 /* first, collect all pa's in the inode */
3918 spin_lock(&ei->i_prealloc_lock);
3919 while (!list_empty(&ei->i_prealloc_list)) {
3920 pa = list_entry(ei->i_prealloc_list.next,
3921 struct ext4_prealloc_space, pa_inode_list);
3922 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
3923 spin_lock(&pa->pa_lock);
3924 if (atomic_read(&pa->pa_count)) {
3925 /* this shouldn't happen often - nobody should
3926 * use preallocation while we're discarding it */
3927 spin_unlock(&pa->pa_lock);
3928 spin_unlock(&ei->i_prealloc_lock);
3929 printk(KERN_ERR "uh-oh! used pa while discarding\n");
3931 schedule_timeout_uninterruptible(HZ);
3935 if (pa->pa_deleted == 0) {
3937 spin_unlock(&pa->pa_lock);
3938 list_del_rcu(&pa->pa_inode_list);
3939 list_add(&pa->u.pa_tmp_list, &list);
3943 /* someone is deleting pa right now */
3944 spin_unlock(&pa->pa_lock);
3945 spin_unlock(&ei->i_prealloc_lock);
3947 /* we have to wait here because pa_deleted
3948 * doesn't mean pa is already unlinked from
3949 * the list. as we might be called from
3950 * ->clear_inode() the inode will get freed
3951 * and concurrent thread which is unlinking
3952 * pa from inode's list may access already
3953 * freed memory, bad-bad-bad */
3955 /* XXX: if this happens too often, we can
3956 * add a flag to force wait only in case
3957 * of ->clear_inode(), but not in case of
3958 * regular truncate */
3959 schedule_timeout_uninterruptible(HZ);
3962 spin_unlock(&ei->i_prealloc_lock);
3964 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3965 BUG_ON(pa->pa_linear != 0);
3966 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
3968 err = ext4_mb_load_buddy(sb, group, &e4b);
3970 ext4_error(sb, __func__, "Error in loading buddy "
3971 "information for %lu\n", group);
3975 bitmap_bh = ext4_read_block_bitmap(sb, group);
3976 if (bitmap_bh == NULL) {
3977 ext4_error(sb, __func__, "Error in reading block "
3978 "bitmap for %lu\n", group);
3979 ext4_mb_release_desc(&e4b);
3983 ext4_lock_group(sb, group);
3984 list_del(&pa->pa_group_list);
3985 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);
3986 ext4_unlock_group(sb, group);
3988 ext4_mb_release_desc(&e4b);
3991 list_del(&pa->u.pa_tmp_list);
3992 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3995 kmem_cache_free(ext4_ac_cachep, ac);
3999 * finds all preallocated spaces and return blocks being freed to them
4000 * if preallocated space becomes full (no block is used from the space)
4001 * then the function frees space in buddy
4002 * XXX: at the moment, truncate (which is the only way to free blocks)
4003 * discards all preallocations
4005 static void ext4_mb_return_to_preallocation(struct inode *inode,
4006 struct ext4_buddy *e4b,
4007 sector_t block, int count)
4009 BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list));
4012 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4014 struct super_block *sb = ac->ac_sb;
4017 printk(KERN_ERR "EXT4-fs: Can't allocate:"
4018 " Allocation context details:\n");
4019 printk(KERN_ERR "EXT4-fs: status %d flags %d\n",
4020 ac->ac_status, ac->ac_flags);
4021 printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
4022 "best %lu/%lu/%lu@%lu cr %d\n",
4023 (unsigned long)ac->ac_o_ex.fe_group,
4024 (unsigned long)ac->ac_o_ex.fe_start,
4025 (unsigned long)ac->ac_o_ex.fe_len,
4026 (unsigned long)ac->ac_o_ex.fe_logical,
4027 (unsigned long)ac->ac_g_ex.fe_group,
4028 (unsigned long)ac->ac_g_ex.fe_start,
4029 (unsigned long)ac->ac_g_ex.fe_len,
4030 (unsigned long)ac->ac_g_ex.fe_logical,
4031 (unsigned long)ac->ac_b_ex.fe_group,
4032 (unsigned long)ac->ac_b_ex.fe_start,
4033 (unsigned long)ac->ac_b_ex.fe_len,
4034 (unsigned long)ac->ac_b_ex.fe_logical,
4035 (int)ac->ac_criteria);
4036 printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
4038 printk(KERN_ERR "EXT4-fs: groups: \n");
4039 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
4040 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4041 struct ext4_prealloc_space *pa;
4042 ext4_grpblk_t start;
4043 struct list_head *cur;
4044 ext4_lock_group(sb, i);
4045 list_for_each(cur, &grp->bb_prealloc_list) {
4046 pa = list_entry(cur, struct ext4_prealloc_space,
4048 spin_lock(&pa->pa_lock);
4049 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4051 spin_unlock(&pa->pa_lock);
4052 printk(KERN_ERR "PA:%lu:%d:%u \n", i,
4055 ext4_unlock_group(sb, i);
4057 if (grp->bb_free == 0)
4059 printk(KERN_ERR "%lu: %d/%d \n",
4060 i, grp->bb_free, grp->bb_fragments);
4062 printk(KERN_ERR "\n");
4065 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4072 * We use locality group preallocation for small size file. The size of the
4073 * file is determined by the current size or the resulting size after
4074 * allocation which ever is larger
4076 * One can tune this size via /proc/fs/ext4/<partition>/stream_req
4078 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4080 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4081 int bsbits = ac->ac_sb->s_blocksize_bits;
4084 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4087 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
4088 isize = i_size_read(ac->ac_inode) >> bsbits;
4089 size = max(size, isize);
4091 /* don't use group allocation for large files */
4092 if (size >= sbi->s_mb_stream_request)
4095 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4098 BUG_ON(ac->ac_lg != NULL);
4100 * locality group prealloc space are per cpu. The reason for having
4101 * per cpu locality group is to reduce the contention between block
4102 * request from multiple CPUs.
4104 ac->ac_lg = &sbi->s_locality_groups[get_cpu()];
4107 /* we're going to use group allocation */
4108 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4110 /* serialize all allocations in the group */
4111 mutex_lock(&ac->ac_lg->lg_mutex);
4114 static noinline_for_stack int
4115 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
4116 struct ext4_allocation_request *ar)
4118 struct super_block *sb = ar->inode->i_sb;
4119 struct ext4_sb_info *sbi = EXT4_SB(sb);
4120 struct ext4_super_block *es = sbi->s_es;
4124 ext4_grpblk_t block;
4126 /* we can't allocate > group size */
4129 /* just a dirty hack to filter too big requests */
4130 if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10)
4131 len = EXT4_BLOCKS_PER_GROUP(sb) - 10;
4133 /* start searching from the goal */
4135 if (goal < le32_to_cpu(es->s_first_data_block) ||
4136 goal >= ext4_blocks_count(es))
4137 goal = le32_to_cpu(es->s_first_data_block);
4138 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4140 /* set up allocation goals */
4141 ac->ac_b_ex.fe_logical = ar->logical;
4142 ac->ac_b_ex.fe_group = 0;
4143 ac->ac_b_ex.fe_start = 0;
4144 ac->ac_b_ex.fe_len = 0;
4145 ac->ac_status = AC_STATUS_CONTINUE;
4146 ac->ac_groups_scanned = 0;
4147 ac->ac_ex_scanned = 0;
4150 ac->ac_inode = ar->inode;
4151 ac->ac_o_ex.fe_logical = ar->logical;
4152 ac->ac_o_ex.fe_group = group;
4153 ac->ac_o_ex.fe_start = block;
4154 ac->ac_o_ex.fe_len = len;
4155 ac->ac_g_ex.fe_logical = ar->logical;
4156 ac->ac_g_ex.fe_group = group;
4157 ac->ac_g_ex.fe_start = block;
4158 ac->ac_g_ex.fe_len = len;
4159 ac->ac_f_ex.fe_len = 0;
4160 ac->ac_flags = ar->flags;
4162 ac->ac_criteria = 0;
4164 ac->ac_bitmap_page = NULL;
4165 ac->ac_buddy_page = NULL;
4168 /* we have to define context: we'll we work with a file or
4169 * locality group. this is a policy, actually */
4170 ext4_mb_group_or_file(ac);
4172 mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4173 "left: %u/%u, right %u/%u to %swritable\n",
4174 (unsigned) ar->len, (unsigned) ar->logical,
4175 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4176 (unsigned) ar->lleft, (unsigned) ar->pleft,
4177 (unsigned) ar->lright, (unsigned) ar->pright,
4178 atomic_read(&ar->inode->i_writecount) ? "" : "non-");
4183 static noinline_for_stack void
4184 ext4_mb_discard_lg_preallocations(struct super_block *sb,
4185 struct ext4_locality_group *lg,
4186 int order, int total_entries)
4188 ext4_group_t group = 0;
4189 struct ext4_buddy e4b;
4190 struct list_head discard_list;
4191 struct ext4_prealloc_space *pa, *tmp;
4192 struct ext4_allocation_context *ac;
4194 mb_debug("discard locality group preallocation\n");
4196 INIT_LIST_HEAD(&discard_list);
4197 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4199 spin_lock(&lg->lg_prealloc_lock);
4200 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
4202 spin_lock(&pa->pa_lock);
4203 if (atomic_read(&pa->pa_count)) {
4205 * This is the pa that we just used
4206 * for block allocation. So don't
4209 spin_unlock(&pa->pa_lock);
4212 if (pa->pa_deleted) {
4213 spin_unlock(&pa->pa_lock);
4216 /* only lg prealloc space */
4217 BUG_ON(!pa->pa_linear);
4219 /* seems this one can be freed ... */
4221 spin_unlock(&pa->pa_lock);
4223 list_del_rcu(&pa->pa_inode_list);
4224 list_add(&pa->u.pa_tmp_list, &discard_list);
4227 if (total_entries <= 5) {
4229 * we want to keep only 5 entries
4230 * allowing it to grow to 8. This
4231 * mak sure we don't call discard
4232 * soon for this list.
4237 spin_unlock(&lg->lg_prealloc_lock);
4239 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
4241 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
4242 if (ext4_mb_load_buddy(sb, group, &e4b)) {
4243 ext4_error(sb, __func__, "Error in loading buddy "
4244 "information for %lu\n", group);
4247 ext4_lock_group(sb, group);
4248 list_del(&pa->pa_group_list);
4249 ext4_mb_release_group_pa(&e4b, pa, ac);
4250 ext4_unlock_group(sb, group);
4252 ext4_mb_release_desc(&e4b);
4253 list_del(&pa->u.pa_tmp_list);
4254 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4257 kmem_cache_free(ext4_ac_cachep, ac);
4261 * We have incremented pa_count. So it cannot be freed at this
4262 * point. Also we hold lg_mutex. So no parallel allocation is
4263 * possible from this lg. That means pa_free cannot be updated.
4265 * A parallel ext4_mb_discard_group_preallocations is possible.
4266 * which can cause the lg_prealloc_list to be updated.
4269 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
4271 int order, added = 0, lg_prealloc_count = 1;
4272 struct super_block *sb = ac->ac_sb;
4273 struct ext4_locality_group *lg = ac->ac_lg;
4274 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
4276 order = fls(pa->pa_free) - 1;
4277 if (order > PREALLOC_TB_SIZE - 1)
4278 /* The max size of hash table is PREALLOC_TB_SIZE */
4279 order = PREALLOC_TB_SIZE - 1;
4280 /* Add the prealloc space to lg */
4282 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
4284 spin_lock(&tmp_pa->pa_lock);
4285 if (tmp_pa->pa_deleted) {
4286 spin_unlock(&pa->pa_lock);
4289 if (!added && pa->pa_free < tmp_pa->pa_free) {
4290 /* Add to the tail of the previous entry */
4291 list_add_tail_rcu(&pa->pa_inode_list,
4292 &tmp_pa->pa_inode_list);
4295 * we want to count the total
4296 * number of entries in the list
4299 spin_unlock(&tmp_pa->pa_lock);
4300 lg_prealloc_count++;
4303 list_add_tail_rcu(&pa->pa_inode_list,
4304 &lg->lg_prealloc_list[order]);
4307 /* Now trim the list to be not more than 8 elements */
4308 if (lg_prealloc_count > 8) {
4309 ext4_mb_discard_lg_preallocations(sb, lg,
4310 order, lg_prealloc_count);
4317 * release all resource we used in allocation
4319 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4321 struct ext4_prealloc_space *pa = ac->ac_pa;
4323 if (pa->pa_linear) {
4324 /* see comment in ext4_mb_use_group_pa() */
4325 spin_lock(&pa->pa_lock);
4326 pa->pa_pstart += ac->ac_b_ex.fe_len;
4327 pa->pa_lstart += ac->ac_b_ex.fe_len;
4328 pa->pa_free -= ac->ac_b_ex.fe_len;
4329 pa->pa_len -= ac->ac_b_ex.fe_len;
4330 spin_unlock(&pa->pa_lock);
4332 * We want to add the pa to the right bucket.
4333 * Remove it from the list and while adding
4334 * make sure the list to which we are adding
4337 if (likely(pa->pa_free)) {
4338 spin_lock(pa->pa_obj_lock);
4339 list_del_rcu(&pa->pa_inode_list);
4340 spin_unlock(pa->pa_obj_lock);
4341 ext4_mb_add_n_trim(ac);
4344 ext4_mb_put_pa(ac, ac->ac_sb, pa);
4346 if (ac->ac_bitmap_page)
4347 page_cache_release(ac->ac_bitmap_page);
4348 if (ac->ac_buddy_page)
4349 page_cache_release(ac->ac_buddy_page);
4350 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4351 mutex_unlock(&ac->ac_lg->lg_mutex);
4352 ext4_mb_collect_stats(ac);
4356 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4362 for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) {
4363 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4372 * Main entry point into mballoc to allocate blocks
4373 * it tries to use preallocation first, then falls back
4374 * to usual allocation
4376 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4377 struct ext4_allocation_request *ar, int *errp)
4379 struct ext4_allocation_context *ac = NULL;
4380 struct ext4_sb_info *sbi;
4381 struct super_block *sb;
4382 ext4_fsblk_t block = 0;
4386 sb = ar->inode->i_sb;
4389 if (!test_opt(sb, MBALLOC)) {
4390 block = ext4_old_new_blocks(handle, ar->inode, ar->goal,
4394 if (!EXT4_I(ar->inode)->i_delalloc_reserved_flag) {
4396 * With delalloc we already reserved the blocks
4398 if (ext4_claim_free_blocks(sbi, ar->len)) {
4403 while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
4404 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4413 if (EXT4_I(ar->inode)->i_delalloc_reserved_flag)
4414 ar->flags |= EXT4_MB_DELALLOC_RESERVED;
4416 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4423 ext4_mb_poll_new_transaction(sb, handle);
4425 *errp = ext4_mb_initialize_context(ac, ar);
4431 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4432 if (!ext4_mb_use_preallocated(ac)) {
4433 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4434 ext4_mb_normalize_request(ac, ar);
4436 /* allocate space in core */
4437 ext4_mb_regular_allocator(ac);
4439 /* as we've just preallocated more space than
4440 * user requested orinally, we store allocated
4441 * space in a special descriptor */
4442 if (ac->ac_status == AC_STATUS_FOUND &&
4443 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4444 ext4_mb_new_preallocation(ac);
4447 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
4448 *errp = ext4_mb_mark_diskspace_used(ac, handle);
4449 if (*errp == -EAGAIN) {
4450 ac->ac_b_ex.fe_group = 0;
4451 ac->ac_b_ex.fe_start = 0;
4452 ac->ac_b_ex.fe_len = 0;
4453 ac->ac_status = AC_STATUS_CONTINUE;
4456 ac->ac_b_ex.fe_len = 0;
4458 ext4_mb_show_ac(ac);
4460 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4461 ar->len = ac->ac_b_ex.fe_len;
4464 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
4468 ac->ac_b_ex.fe_len = 0;
4470 ext4_mb_show_ac(ac);
4473 ext4_mb_release_context(ac);
4476 kmem_cache_free(ext4_ac_cachep, ac);
4478 if (ar->len < inquota)
4479 DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
4483 static void ext4_mb_poll_new_transaction(struct super_block *sb,
4486 struct ext4_sb_info *sbi = EXT4_SB(sb);
4488 if (sbi->s_last_transaction == handle->h_transaction->t_tid)
4491 /* new transaction! time to close last one and free blocks for
4492 * committed transaction. we know that only transaction can be
4493 * active, so previos transaction can be being logged and we
4494 * know that transaction before previous is known to be already
4495 * logged. this means that now we may free blocks freed in all
4496 * transactions before previous one. hope I'm clear enough ... */
4498 spin_lock(&sbi->s_md_lock);
4499 if (sbi->s_last_transaction != handle->h_transaction->t_tid) {
4500 mb_debug("new transaction %lu, old %lu\n",
4501 (unsigned long) handle->h_transaction->t_tid,
4502 (unsigned long) sbi->s_last_transaction);
4503 list_splice_init(&sbi->s_closed_transaction,
4504 &sbi->s_committed_transaction);
4505 list_splice_init(&sbi->s_active_transaction,
4506 &sbi->s_closed_transaction);
4507 sbi->s_last_transaction = handle->h_transaction->t_tid;
4509 spin_unlock(&sbi->s_md_lock);
4511 ext4_mb_free_committed_blocks(sb);
4514 static noinline_for_stack int
4515 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
4516 ext4_group_t group, ext4_grpblk_t block, int count)
4518 struct ext4_group_info *db = e4b->bd_info;
4519 struct super_block *sb = e4b->bd_sb;
4520 struct ext4_sb_info *sbi = EXT4_SB(sb);
4521 struct ext4_free_metadata *md;
4524 BUG_ON(e4b->bd_bitmap_page == NULL);
4525 BUG_ON(e4b->bd_buddy_page == NULL);
4527 ext4_lock_group(sb, group);
4528 for (i = 0; i < count; i++) {
4530 if (md && db->bb_tid != handle->h_transaction->t_tid) {
4531 db->bb_md_cur = NULL;
4536 ext4_unlock_group(sb, group);
4537 md = kmalloc(sizeof(*md), GFP_NOFS);
4543 ext4_lock_group(sb, group);
4544 if (db->bb_md_cur == NULL) {
4545 spin_lock(&sbi->s_md_lock);
4546 list_add(&md->list, &sbi->s_active_transaction);
4547 spin_unlock(&sbi->s_md_lock);
4548 /* protect buddy cache from being freed,
4549 * otherwise we'll refresh it from
4550 * on-disk bitmap and lose not-yet-available
4552 page_cache_get(e4b->bd_buddy_page);
4553 page_cache_get(e4b->bd_bitmap_page);
4555 db->bb_tid = handle->h_transaction->t_tid;
4556 mb_debug("new md 0x%p for group %lu\n",
4564 BUG_ON(md->num >= EXT4_BB_MAX_BLOCKS);
4565 md->blocks[md->num] = block + i;
4567 if (md->num == EXT4_BB_MAX_BLOCKS) {
4568 /* no more space, put full container on a sb's list */
4569 db->bb_md_cur = NULL;
4572 ext4_unlock_group(sb, group);
4577 * Main entry point into mballoc to free blocks
4579 void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
4580 unsigned long block, unsigned long count,
4581 int metadata, unsigned long *freed)
4583 struct buffer_head *bitmap_bh = NULL;
4584 struct super_block *sb = inode->i_sb;
4585 struct ext4_allocation_context *ac = NULL;
4586 struct ext4_group_desc *gdp;
4587 struct ext4_super_block *es;
4588 unsigned long overflow;
4590 struct buffer_head *gd_bh;
4591 ext4_group_t block_group;
4592 struct ext4_sb_info *sbi;
4593 struct ext4_buddy e4b;
4599 ext4_mb_poll_new_transaction(sb, handle);
4602 es = EXT4_SB(sb)->s_es;
4603 if (block < le32_to_cpu(es->s_first_data_block) ||
4604 block + count < block ||
4605 block + count > ext4_blocks_count(es)) {
4606 ext4_error(sb, __func__,
4607 "Freeing blocks not in datazone - "
4608 "block = %lu, count = %lu", block, count);
4612 ext4_debug("freeing block %lu\n", block);
4614 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4616 ac->ac_op = EXT4_MB_HISTORY_FREE;
4617 ac->ac_inode = inode;
4623 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4626 * Check to see if we are freeing blocks across a group
4629 if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4630 overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
4633 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
4638 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
4644 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4645 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4646 in_range(block, ext4_inode_table(sb, gdp),
4647 EXT4_SB(sb)->s_itb_per_group) ||
4648 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4649 EXT4_SB(sb)->s_itb_per_group)) {
4651 ext4_error(sb, __func__,
4652 "Freeing blocks in system zone - "
4653 "Block = %lu, count = %lu", block, count);
4654 /* err = 0. ext4_std_error should be a no op */
4658 BUFFER_TRACE(bitmap_bh, "getting write access");
4659 err = ext4_journal_get_write_access(handle, bitmap_bh);
4664 * We are about to modify some metadata. Call the journal APIs
4665 * to unshare ->b_data if a currently-committing transaction is
4668 BUFFER_TRACE(gd_bh, "get_write_access");
4669 err = ext4_journal_get_write_access(handle, gd_bh);
4673 err = ext4_mb_load_buddy(sb, block_group, &e4b);
4677 #ifdef AGGRESSIVE_CHECK
4680 for (i = 0; i < count; i++)
4681 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4684 mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
4687 /* We dirtied the bitmap block */
4688 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4689 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
4692 ac->ac_b_ex.fe_group = block_group;
4693 ac->ac_b_ex.fe_start = bit;
4694 ac->ac_b_ex.fe_len = count;
4695 ext4_mb_store_history(ac);
4699 /* blocks being freed are metadata. these blocks shouldn't
4700 * be used until this transaction is committed */
4701 ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
4703 ext4_lock_group(sb, block_group);
4704 mb_free_blocks(inode, &e4b, bit, count);
4705 ext4_mb_return_to_preallocation(inode, &e4b, block, count);
4706 ext4_unlock_group(sb, block_group);
4709 spin_lock(sb_bgl_lock(sbi, block_group));
4710 le16_add_cpu(&gdp->bg_free_blocks_count, count);
4711 gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
4712 spin_unlock(sb_bgl_lock(sbi, block_group));
4713 percpu_counter_add(&sbi->s_freeblocks_counter, count);
4715 if (sbi->s_log_groups_per_flex) {
4716 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
4717 spin_lock(sb_bgl_lock(sbi, flex_group));
4718 sbi->s_flex_groups[flex_group].free_blocks += count;
4719 spin_unlock(sb_bgl_lock(sbi, flex_group));
4722 ext4_mb_release_desc(&e4b);
4726 /* And the group descriptor block */
4727 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4728 ret = ext4_journal_dirty_metadata(handle, gd_bh);
4732 if (overflow && !err) {
4741 ext4_std_error(sb, err);
4743 kmem_cache_free(ext4_ac_cachep, ac);