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 License
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
24 #include "ext4_jbd2.h"
26 #include <linux/log2.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <linux/backing-dev.h>
30 #include <trace/events/ext4.h>
32 #ifdef CONFIG_EXT4_DEBUG
33 ushort ext4_mballoc_debug __read_mostly;
35 module_param_named(mballoc_debug, ext4_mballoc_debug, ushort, 0644);
36 MODULE_PARM_DESC(mballoc_debug, "Debugging level for ext4's mballoc");
41 * - test ext4_ext_search_left() and ext4_ext_search_right()
42 * - search for metadata in few groups
45 * - normalization should take into account whether file is still open
46 * - discard preallocations if no free space left (policy?)
47 * - don't normalize tails
49 * - reservation for superuser
52 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
53 * - track min/max extents in each group for better group selection
54 * - mb_mark_used() may allocate chunk right after splitting buddy
55 * - tree of groups sorted by number of free blocks
60 * The allocation request involve request for multiple number of blocks
61 * near to the goal(block) value specified.
63 * During initialization phase of the allocator we decide to use the
64 * group preallocation or inode preallocation depending on the size of
65 * the file. The size of the file could be the resulting file size we
66 * would have after allocation, or the current file size, which ever
67 * is larger. If the size is less than sbi->s_mb_stream_request we
68 * select to use the group preallocation. The default value of
69 * s_mb_stream_request is 16 blocks. This can also be tuned via
70 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
71 * terms of number of blocks.
73 * The main motivation for having small file use group preallocation is to
74 * ensure that we have small files closer together on the disk.
76 * First stage the allocator looks at the inode prealloc list,
77 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
78 * spaces for this particular inode. The inode prealloc space is
81 * pa_lstart -> the logical start block for this prealloc space
82 * pa_pstart -> the physical start block for this prealloc space
83 * pa_len -> length for this prealloc space (in clusters)
84 * pa_free -> free space available in this prealloc space (in clusters)
86 * The inode preallocation space is used looking at the _logical_ start
87 * block. If only the logical file block falls within the range of prealloc
88 * space we will consume the particular prealloc space. This makes sure that
89 * we have contiguous physical blocks representing the file blocks
91 * The important thing to be noted in case of inode prealloc space is that
92 * we don't modify the values associated to inode prealloc space except
95 * If we are not able to find blocks in the inode prealloc space and if we
96 * have the group allocation flag set then we look at the locality group
97 * prealloc space. These are per CPU prealloc list represented as
99 * ext4_sb_info.s_locality_groups[smp_processor_id()]
101 * The reason for having a per cpu locality group is to reduce the contention
102 * between CPUs. It is possible to get scheduled at this point.
104 * The locality group prealloc space is used looking at whether we have
105 * enough free space (pa_free) within the prealloc space.
107 * If we can't allocate blocks via inode prealloc or/and locality group
108 * prealloc then we look at the buddy cache. The buddy cache is represented
109 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
110 * mapped to the buddy and bitmap information regarding different
111 * groups. The buddy information is attached to buddy cache inode so that
112 * we can access them through the page cache. The information regarding
113 * each group is loaded via ext4_mb_load_buddy. The information involve
114 * block bitmap and buddy information. The information are stored in the
118 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
121 * one block each for bitmap and buddy information. So for each group we
122 * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
123 * blocksize) blocks. So it can have information regarding groups_per_page
124 * which is blocks_per_page/2
126 * The buddy cache inode is not stored on disk. The inode is thrown
127 * away when the filesystem is unmounted.
129 * We look for count number of blocks in the buddy cache. If we were able
130 * to locate that many free blocks we return with additional information
131 * regarding rest of the contiguous physical block available
133 * Before allocating blocks via buddy cache we normalize the request
134 * blocks. This ensure we ask for more blocks that we needed. The extra
135 * blocks that we get after allocation is added to the respective prealloc
136 * list. In case of inode preallocation we follow a list of heuristics
137 * based on file size. This can be found in ext4_mb_normalize_request. If
138 * we are doing a group prealloc we try to normalize the request to
139 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
140 * dependent on the cluster size; for non-bigalloc file systems, it is
141 * 512 blocks. This can be tuned via
142 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
143 * terms of number of blocks. If we have mounted the file system with -O
144 * stripe=<value> option the group prealloc request is normalized to the
145 * the smallest multiple of the stripe value (sbi->s_stripe) which is
146 * greater than the default mb_group_prealloc.
148 * The regular allocator (using the buddy cache) supports a few tunables.
150 * /sys/fs/ext4/<partition>/mb_min_to_scan
151 * /sys/fs/ext4/<partition>/mb_max_to_scan
152 * /sys/fs/ext4/<partition>/mb_order2_req
154 * The regular allocator uses buddy scan only if the request len is power of
155 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
156 * value of s_mb_order2_reqs can be tuned via
157 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
158 * stripe size (sbi->s_stripe), we try to search for contiguous block in
159 * stripe size. This should result in better allocation on RAID setups. If
160 * not, we search in the specific group using bitmap for best extents. The
161 * tunable min_to_scan and max_to_scan control the behaviour here.
162 * min_to_scan indicate how long the mballoc __must__ look for a best
163 * extent and max_to_scan indicates how long the mballoc __can__ look for a
164 * best extent in the found extents. Searching for the blocks starts with
165 * the group specified as the goal value in allocation context via
166 * ac_g_ex. Each group is first checked based on the criteria whether it
167 * can be used for allocation. ext4_mb_good_group explains how the groups are
170 * Both the prealloc space are getting populated as above. So for the first
171 * request we will hit the buddy cache which will result in this prealloc
172 * space getting filled. The prealloc space is then later used for the
173 * subsequent request.
177 * mballoc operates on the following data:
179 * - in-core buddy (actually includes buddy and bitmap)
180 * - preallocation descriptors (PAs)
182 * there are two types of preallocations:
184 * assiged to specific inode and can be used for this inode only.
185 * it describes part of inode's space preallocated to specific
186 * physical blocks. any block from that preallocated can be used
187 * independent. the descriptor just tracks number of blocks left
188 * unused. so, before taking some block from descriptor, one must
189 * make sure corresponded logical block isn't allocated yet. this
190 * also means that freeing any block within descriptor's range
191 * must discard all preallocated blocks.
193 * assigned to specific locality group which does not translate to
194 * permanent set of inodes: inode can join and leave group. space
195 * from this type of preallocation can be used for any inode. thus
196 * it's consumed from the beginning to the end.
198 * relation between them can be expressed as:
199 * in-core buddy = on-disk bitmap + preallocation descriptors
201 * this mean blocks mballoc considers used are:
202 * - allocated blocks (persistent)
203 * - preallocated blocks (non-persistent)
205 * consistency in mballoc world means that at any time a block is either
206 * free or used in ALL structures. notice: "any time" should not be read
207 * literally -- time is discrete and delimited by locks.
209 * to keep it simple, we don't use block numbers, instead we count number of
210 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
212 * all operations can be expressed as:
213 * - init buddy: buddy = on-disk + PAs
214 * - new PA: buddy += N; PA = N
215 * - use inode PA: on-disk += N; PA -= N
216 * - discard inode PA buddy -= on-disk - PA; PA = 0
217 * - use locality group PA on-disk += N; PA -= N
218 * - discard locality group PA buddy -= PA; PA = 0
219 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
220 * is used in real operation because we can't know actual used
221 * bits from PA, only from on-disk bitmap
223 * if we follow this strict logic, then all operations above should be atomic.
224 * given some of them can block, we'd have to use something like semaphores
225 * killing performance on high-end SMP hardware. let's try to relax it using
226 * the following knowledge:
227 * 1) if buddy is referenced, it's already initialized
228 * 2) while block is used in buddy and the buddy is referenced,
229 * nobody can re-allocate that block
230 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
231 * bit set and PA claims same block, it's OK. IOW, one can set bit in
232 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
235 * so, now we're building a concurrency table:
238 * blocks for PA are allocated in the buddy, buddy must be referenced
239 * until PA is linked to allocation group to avoid concurrent buddy init
241 * we need to make sure that either on-disk bitmap or PA has uptodate data
242 * given (3) we care that PA-=N operation doesn't interfere with init
244 * the simplest way would be to have buddy initialized by the discard
245 * - use locality group PA
246 * again PA-=N must be serialized with init
247 * - discard locality group PA
248 * the simplest way would be to have buddy initialized by the discard
251 * i_data_sem serializes them
253 * discard process must wait until PA isn't used by another process
254 * - use locality group PA
255 * some mutex should serialize them
256 * - discard locality group PA
257 * discard process must wait until PA isn't used by another process
260 * i_data_sem or another mutex should serializes them
262 * discard process must wait until PA isn't used by another process
263 * - use locality group PA
264 * nothing wrong here -- they're different PAs covering different blocks
265 * - discard locality group PA
266 * discard process must wait until PA isn't used by another process
268 * now we're ready to make few consequences:
269 * - PA is referenced and while it is no discard is possible
270 * - PA is referenced until block isn't marked in on-disk bitmap
271 * - PA changes only after on-disk bitmap
272 * - discard must not compete with init. either init is done before
273 * any discard or they're serialized somehow
274 * - buddy init as sum of on-disk bitmap and PAs is done atomically
276 * a special case when we've used PA to emptiness. no need to modify buddy
277 * in this case, but we should care about concurrent init
282 * Logic in few words:
287 * mark bits in on-disk bitmap
290 * - use preallocation:
291 * find proper PA (per-inode or group)
293 * mark bits in on-disk bitmap
299 * mark bits in on-disk bitmap
302 * - discard preallocations in group:
304 * move them onto local list
305 * load on-disk bitmap
307 * remove PA from object (inode or locality group)
308 * mark free blocks in-core
310 * - discard inode's preallocations:
317 * - bitlock on a group (group)
318 * - object (inode/locality) (object)
329 * - release consumed pa:
334 * - generate in-core bitmap:
338 * - discard all for given object (inode, locality group):
343 * - discard all for given group:
350 static struct kmem_cache *ext4_pspace_cachep;
351 static struct kmem_cache *ext4_ac_cachep;
352 static struct kmem_cache *ext4_free_data_cachep;
354 /* We create slab caches for groupinfo data structures based on the
355 * superblock block size. There will be one per mounted filesystem for
356 * each unique s_blocksize_bits */
357 #define NR_GRPINFO_CACHES 8
358 static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
360 static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
361 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
362 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
363 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
366 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
368 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
371 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
373 #if BITS_PER_LONG == 64
374 *bit += ((unsigned long) addr & 7UL) << 3;
375 addr = (void *) ((unsigned long) addr & ~7UL);
376 #elif BITS_PER_LONG == 32
377 *bit += ((unsigned long) addr & 3UL) << 3;
378 addr = (void *) ((unsigned long) addr & ~3UL);
380 #error "how many bits you are?!"
385 static inline int mb_test_bit(int bit, void *addr)
388 * ext4_test_bit on architecture like powerpc
389 * needs unsigned long aligned address
391 addr = mb_correct_addr_and_bit(&bit, addr);
392 return ext4_test_bit(bit, addr);
395 static inline void mb_set_bit(int bit, void *addr)
397 addr = mb_correct_addr_and_bit(&bit, addr);
398 ext4_set_bit(bit, addr);
401 static inline void mb_clear_bit(int bit, void *addr)
403 addr = mb_correct_addr_and_bit(&bit, addr);
404 ext4_clear_bit(bit, addr);
407 static inline int mb_test_and_clear_bit(int bit, void *addr)
409 addr = mb_correct_addr_and_bit(&bit, addr);
410 return ext4_test_and_clear_bit(bit, addr);
413 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
415 int fix = 0, ret, tmpmax;
416 addr = mb_correct_addr_and_bit(&fix, addr);
420 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
426 static inline int mb_find_next_bit(void *addr, int max, int start)
428 int fix = 0, ret, tmpmax;
429 addr = mb_correct_addr_and_bit(&fix, addr);
433 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
439 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
443 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
446 if (order > e4b->bd_blkbits + 1) {
451 /* at order 0 we see each particular block */
453 *max = 1 << (e4b->bd_blkbits + 3);
454 return e4b->bd_bitmap;
457 bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
458 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
464 static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
465 int first, int count)
468 struct super_block *sb = e4b->bd_sb;
470 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
472 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
473 for (i = 0; i < count; i++) {
474 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
475 ext4_fsblk_t blocknr;
477 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
478 blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
479 ext4_grp_locked_error(sb, e4b->bd_group,
480 inode ? inode->i_ino : 0,
482 "freeing block already freed "
486 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
490 static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
494 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
496 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
497 for (i = 0; i < count; i++) {
498 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
499 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
503 static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
505 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
506 unsigned char *b1, *b2;
508 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
509 b2 = (unsigned char *) bitmap;
510 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
511 if (b1[i] != b2[i]) {
512 ext4_msg(e4b->bd_sb, KERN_ERR,
513 "corruption in group %u "
514 "at byte %u(%u): %x in copy != %x "
516 e4b->bd_group, i, i * 8, b1[i], b2[i]);
524 static inline void mb_free_blocks_double(struct inode *inode,
525 struct ext4_buddy *e4b, int first, int count)
529 static inline void mb_mark_used_double(struct ext4_buddy *e4b,
530 int first, int count)
534 static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
540 #ifdef AGGRESSIVE_CHECK
542 #define MB_CHECK_ASSERT(assert) \
546 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
547 function, file, line, # assert); \
552 static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
553 const char *function, int line)
555 struct super_block *sb = e4b->bd_sb;
556 int order = e4b->bd_blkbits + 1;
563 struct ext4_group_info *grp;
566 struct list_head *cur;
571 static int mb_check_counter;
572 if (mb_check_counter++ % 100 != 0)
577 buddy = mb_find_buddy(e4b, order, &max);
578 MB_CHECK_ASSERT(buddy);
579 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
580 MB_CHECK_ASSERT(buddy2);
581 MB_CHECK_ASSERT(buddy != buddy2);
582 MB_CHECK_ASSERT(max * 2 == max2);
585 for (i = 0; i < max; i++) {
587 if (mb_test_bit(i, buddy)) {
588 /* only single bit in buddy2 may be 1 */
589 if (!mb_test_bit(i << 1, buddy2)) {
591 mb_test_bit((i<<1)+1, buddy2));
592 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
594 mb_test_bit(i << 1, buddy2));
599 /* both bits in buddy2 must be 1 */
600 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
601 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
603 for (j = 0; j < (1 << order); j++) {
604 k = (i * (1 << order)) + j;
606 !mb_test_bit(k, e4b->bd_bitmap));
610 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
615 buddy = mb_find_buddy(e4b, 0, &max);
616 for (i = 0; i < max; i++) {
617 if (!mb_test_bit(i, buddy)) {
618 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
626 /* check used bits only */
627 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
628 buddy2 = mb_find_buddy(e4b, j, &max2);
630 MB_CHECK_ASSERT(k < max2);
631 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
634 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
635 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
637 grp = ext4_get_group_info(sb, e4b->bd_group);
638 list_for_each(cur, &grp->bb_prealloc_list) {
639 ext4_group_t groupnr;
640 struct ext4_prealloc_space *pa;
641 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
642 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
643 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
644 for (i = 0; i < pa->pa_len; i++)
645 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
649 #undef MB_CHECK_ASSERT
650 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
651 __FILE__, __func__, __LINE__)
653 #define mb_check_buddy(e4b)
657 * Divide blocks started from @first with length @len into
658 * smaller chunks with power of 2 blocks.
659 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
660 * then increase bb_counters[] for corresponded chunk size.
662 static void ext4_mb_mark_free_simple(struct super_block *sb,
663 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
664 struct ext4_group_info *grp)
666 struct ext4_sb_info *sbi = EXT4_SB(sb);
672 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
674 border = 2 << sb->s_blocksize_bits;
677 /* find how many blocks can be covered since this position */
678 max = ffs(first | border) - 1;
680 /* find how many blocks of power 2 we need to mark */
687 /* mark multiblock chunks only */
688 grp->bb_counters[min]++;
690 mb_clear_bit(first >> min,
691 buddy + sbi->s_mb_offsets[min]);
699 * Cache the order of the largest free extent we have available in this block
703 mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
708 grp->bb_largest_free_order = -1; /* uninit */
710 bits = sb->s_blocksize_bits + 1;
711 for (i = bits; i >= 0; i--) {
712 if (grp->bb_counters[i] > 0) {
713 grp->bb_largest_free_order = i;
719 static noinline_for_stack
720 void ext4_mb_generate_buddy(struct super_block *sb,
721 void *buddy, void *bitmap, ext4_group_t group)
723 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
724 struct ext4_sb_info *sbi = EXT4_SB(sb);
725 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
730 unsigned fragments = 0;
731 unsigned long long period = get_cycles();
733 /* initialize buddy from bitmap which is aggregation
734 * of on-disk bitmap and preallocations */
735 i = mb_find_next_zero_bit(bitmap, max, 0);
736 grp->bb_first_free = i;
740 i = mb_find_next_bit(bitmap, max, i);
744 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
746 grp->bb_counters[0]++;
748 i = mb_find_next_zero_bit(bitmap, max, i);
750 grp->bb_fragments = fragments;
752 if (free != grp->bb_free) {
753 ext4_grp_locked_error(sb, group, 0, 0,
754 "block bitmap and bg descriptor "
755 "inconsistent: %u vs %u free clusters",
758 * If we intend to continue, we consider group descriptor
759 * corrupt and update bb_free using bitmap value
762 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
763 percpu_counter_sub(&sbi->s_freeclusters_counter,
765 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
767 mb_set_largest_free_order(sb, grp);
769 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
771 period = get_cycles() - period;
772 spin_lock(&EXT4_SB(sb)->s_bal_lock);
773 EXT4_SB(sb)->s_mb_buddies_generated++;
774 EXT4_SB(sb)->s_mb_generation_time += period;
775 spin_unlock(&EXT4_SB(sb)->s_bal_lock);
778 static void mb_regenerate_buddy(struct ext4_buddy *e4b)
784 while ((buddy = mb_find_buddy(e4b, order++, &count))) {
785 ext4_set_bits(buddy, 0, count);
787 e4b->bd_info->bb_fragments = 0;
788 memset(e4b->bd_info->bb_counters, 0,
789 sizeof(*e4b->bd_info->bb_counters) *
790 (e4b->bd_sb->s_blocksize_bits + 2));
792 ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy,
793 e4b->bd_bitmap, e4b->bd_group);
796 /* The buddy information is attached the buddy cache inode
797 * for convenience. The information regarding each group
798 * is loaded via ext4_mb_load_buddy. The information involve
799 * block bitmap and buddy information. The information are
800 * stored in the inode as
803 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
806 * one block each for bitmap and buddy information.
807 * So for each group we take up 2 blocks. A page can
808 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
809 * So it can have information regarding groups_per_page which
810 * is blocks_per_page/2
812 * Locking note: This routine takes the block group lock of all groups
813 * for this page; do not hold this lock when calling this routine!
816 static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
818 ext4_group_t ngroups;
824 ext4_group_t first_group, group;
826 struct super_block *sb;
827 struct buffer_head *bhs;
828 struct buffer_head **bh = NULL;
832 struct ext4_group_info *grinfo;
834 mb_debug(1, "init page %lu\n", page->index);
836 inode = page->mapping->host;
838 ngroups = ext4_get_groups_count(sb);
839 blocksize = i_blocksize(inode);
840 blocks_per_page = PAGE_SIZE / blocksize;
842 groups_per_page = blocks_per_page >> 1;
843 if (groups_per_page == 0)
846 /* allocate buffer_heads to read bitmaps */
847 if (groups_per_page > 1) {
848 i = sizeof(struct buffer_head *) * groups_per_page;
849 bh = kzalloc(i, gfp);
857 first_group = page->index * blocks_per_page / 2;
859 /* read all groups the page covers into the cache */
860 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
861 if (group >= ngroups)
864 grinfo = ext4_get_group_info(sb, group);
866 * If page is uptodate then we came here after online resize
867 * which added some new uninitialized group info structs, so
868 * we must skip all initialized uptodate buddies on the page,
869 * which may be currently in use by an allocating task.
871 if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
875 bh[i] = ext4_read_block_bitmap_nowait(sb, group);
877 err = PTR_ERR(bh[i]);
881 mb_debug(1, "read bitmap for group %u\n", group);
884 /* wait for I/O completion */
885 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
890 err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
895 first_block = page->index * blocks_per_page;
896 for (i = 0; i < blocks_per_page; i++) {
897 group = (first_block + i) >> 1;
898 if (group >= ngroups)
901 if (!bh[group - first_group])
902 /* skip initialized uptodate buddy */
905 if (!buffer_verified(bh[group - first_group]))
906 /* Skip faulty bitmaps */
911 * data carry information regarding this
912 * particular group in the format specified
916 data = page_address(page) + (i * blocksize);
917 bitmap = bh[group - first_group]->b_data;
920 * We place the buddy block and bitmap block
923 if ((first_block + i) & 1) {
924 /* this is block of buddy */
925 BUG_ON(incore == NULL);
926 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
927 group, page->index, i * blocksize);
928 trace_ext4_mb_buddy_bitmap_load(sb, group);
929 grinfo = ext4_get_group_info(sb, group);
930 grinfo->bb_fragments = 0;
931 memset(grinfo->bb_counters, 0,
932 sizeof(*grinfo->bb_counters) *
933 (sb->s_blocksize_bits+2));
935 * incore got set to the group block bitmap below
937 ext4_lock_group(sb, group);
939 memset(data, 0xff, blocksize);
940 ext4_mb_generate_buddy(sb, data, incore, group);
941 ext4_unlock_group(sb, group);
944 /* this is block of bitmap */
945 BUG_ON(incore != NULL);
946 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
947 group, page->index, i * blocksize);
948 trace_ext4_mb_bitmap_load(sb, group);
950 /* see comments in ext4_mb_put_pa() */
951 ext4_lock_group(sb, group);
952 memcpy(data, bitmap, blocksize);
954 /* mark all preallocated blks used in in-core bitmap */
955 ext4_mb_generate_from_pa(sb, data, group);
956 ext4_mb_generate_from_freelist(sb, data, group);
957 ext4_unlock_group(sb, group);
959 /* set incore so that the buddy information can be
960 * generated using this
965 SetPageUptodate(page);
969 for (i = 0; i < groups_per_page; i++)
978 * Lock the buddy and bitmap pages. This make sure other parallel init_group
979 * on the same buddy page doesn't happen whild holding the buddy page lock.
980 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
981 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
983 static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
984 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
986 struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
987 int block, pnum, poff;
991 e4b->bd_buddy_page = NULL;
992 e4b->bd_bitmap_page = NULL;
994 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
996 * the buddy cache inode stores the block bitmap
997 * and buddy information in consecutive blocks.
998 * So for each group we need two blocks.
1001 pnum = block / blocks_per_page;
1002 poff = block % blocks_per_page;
1003 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1006 BUG_ON(page->mapping != inode->i_mapping);
1007 e4b->bd_bitmap_page = page;
1008 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1010 if (blocks_per_page >= 2) {
1011 /* buddy and bitmap are on the same page */
1016 pnum = block / blocks_per_page;
1017 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1020 BUG_ON(page->mapping != inode->i_mapping);
1021 e4b->bd_buddy_page = page;
1025 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1027 if (e4b->bd_bitmap_page) {
1028 unlock_page(e4b->bd_bitmap_page);
1029 put_page(e4b->bd_bitmap_page);
1031 if (e4b->bd_buddy_page) {
1032 unlock_page(e4b->bd_buddy_page);
1033 put_page(e4b->bd_buddy_page);
1038 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1039 * block group lock of all groups for this page; do not hold the BG lock when
1040 * calling this routine!
1042 static noinline_for_stack
1043 int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1046 struct ext4_group_info *this_grp;
1047 struct ext4_buddy e4b;
1052 mb_debug(1, "init group %u\n", group);
1053 this_grp = ext4_get_group_info(sb, group);
1055 * This ensures that we don't reinit the buddy cache
1056 * page which map to the group from which we are already
1057 * allocating. If we are looking at the buddy cache we would
1058 * have taken a reference using ext4_mb_load_buddy and that
1059 * would have pinned buddy page to page cache.
1060 * The call to ext4_mb_get_buddy_page_lock will mark the
1063 ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp);
1064 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1066 * somebody initialized the group
1067 * return without doing anything
1072 page = e4b.bd_bitmap_page;
1073 ret = ext4_mb_init_cache(page, NULL, gfp);
1076 if (!PageUptodate(page)) {
1081 if (e4b.bd_buddy_page == NULL) {
1083 * If both the bitmap and buddy are in
1084 * the same page we don't need to force
1090 /* init buddy cache */
1091 page = e4b.bd_buddy_page;
1092 ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp);
1095 if (!PageUptodate(page)) {
1100 ext4_mb_put_buddy_page_lock(&e4b);
1105 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1106 * block group lock of all groups for this page; do not hold the BG lock when
1107 * calling this routine!
1109 static noinline_for_stack int
1110 ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1111 struct ext4_buddy *e4b, gfp_t gfp)
1113 int blocks_per_page;
1119 struct ext4_group_info *grp;
1120 struct ext4_sb_info *sbi = EXT4_SB(sb);
1121 struct inode *inode = sbi->s_buddy_cache;
1124 mb_debug(1, "load group %u\n", group);
1126 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1127 grp = ext4_get_group_info(sb, group);
1129 e4b->bd_blkbits = sb->s_blocksize_bits;
1132 e4b->bd_group = group;
1133 e4b->bd_buddy_page = NULL;
1134 e4b->bd_bitmap_page = NULL;
1136 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1138 * we need full data about the group
1139 * to make a good selection
1141 ret = ext4_mb_init_group(sb, group, gfp);
1147 * the buddy cache inode stores the block bitmap
1148 * and buddy information in consecutive blocks.
1149 * So for each group we need two blocks.
1152 pnum = block / blocks_per_page;
1153 poff = block % blocks_per_page;
1155 /* we could use find_or_create_page(), but it locks page
1156 * what we'd like to avoid in fast path ... */
1157 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1158 if (page == NULL || !PageUptodate(page)) {
1161 * drop the page reference and try
1162 * to get the page with lock. If we
1163 * are not uptodate that implies
1164 * somebody just created the page but
1165 * is yet to initialize the same. So
1166 * wait for it to initialize.
1169 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1171 BUG_ON(page->mapping != inode->i_mapping);
1172 if (!PageUptodate(page)) {
1173 ret = ext4_mb_init_cache(page, NULL, gfp);
1178 mb_cmp_bitmaps(e4b, page_address(page) +
1179 (poff * sb->s_blocksize));
1188 if (!PageUptodate(page)) {
1193 /* Pages marked accessed already */
1194 e4b->bd_bitmap_page = page;
1195 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1198 pnum = block / blocks_per_page;
1199 poff = block % blocks_per_page;
1201 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1202 if (page == NULL || !PageUptodate(page)) {
1205 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1207 BUG_ON(page->mapping != inode->i_mapping);
1208 if (!PageUptodate(page)) {
1209 ret = ext4_mb_init_cache(page, e4b->bd_bitmap,
1223 if (!PageUptodate(page)) {
1228 /* Pages marked accessed already */
1229 e4b->bd_buddy_page = page;
1230 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1232 BUG_ON(e4b->bd_bitmap_page == NULL);
1233 BUG_ON(e4b->bd_buddy_page == NULL);
1240 if (e4b->bd_bitmap_page)
1241 put_page(e4b->bd_bitmap_page);
1242 if (e4b->bd_buddy_page)
1243 put_page(e4b->bd_buddy_page);
1244 e4b->bd_buddy = NULL;
1245 e4b->bd_bitmap = NULL;
1249 static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1250 struct ext4_buddy *e4b)
1252 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1255 static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1257 if (e4b->bd_bitmap_page)
1258 put_page(e4b->bd_bitmap_page);
1259 if (e4b->bd_buddy_page)
1260 put_page(e4b->bd_buddy_page);
1264 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1267 int bb_incr = 1 << (e4b->bd_blkbits - 1);
1270 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1271 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1274 while (order <= e4b->bd_blkbits + 1) {
1276 if (!mb_test_bit(block, bb)) {
1277 /* this block is part of buddy of order 'order' */
1287 static void mb_clear_bits(void *bm, int cur, int len)
1293 if ((cur & 31) == 0 && (len - cur) >= 32) {
1294 /* fast path: clear whole word at once */
1295 addr = bm + (cur >> 3);
1300 mb_clear_bit(cur, bm);
1305 /* clear bits in given range
1306 * will return first found zero bit if any, -1 otherwise
1308 static int mb_test_and_clear_bits(void *bm, int cur, int len)
1315 if ((cur & 31) == 0 && (len - cur) >= 32) {
1316 /* fast path: clear whole word at once */
1317 addr = bm + (cur >> 3);
1318 if (*addr != (__u32)(-1) && zero_bit == -1)
1319 zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0);
1324 if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1)
1332 void ext4_set_bits(void *bm, int cur, int len)
1338 if ((cur & 31) == 0 && (len - cur) >= 32) {
1339 /* fast path: set whole word at once */
1340 addr = bm + (cur >> 3);
1345 mb_set_bit(cur, bm);
1351 * _________________________________________________________________ */
1353 static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1355 if (mb_test_bit(*bit + side, bitmap)) {
1356 mb_clear_bit(*bit, bitmap);
1362 mb_set_bit(*bit, bitmap);
1367 static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1371 void *buddy = mb_find_buddy(e4b, order, &max);
1376 /* Bits in range [first; last] are known to be set since
1377 * corresponding blocks were allocated. Bits in range
1378 * (first; last) will stay set because they form buddies on
1379 * upper layer. We just deal with borders if they don't
1380 * align with upper layer and then go up.
1381 * Releasing entire group is all about clearing
1382 * single bit of highest order buddy.
1386 * ---------------------------------
1388 * ---------------------------------
1389 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1390 * ---------------------------------
1392 * \_____________________/
1394 * Neither [1] nor [6] is aligned to above layer.
1395 * Left neighbour [0] is free, so mark it busy,
1396 * decrease bb_counters and extend range to
1398 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1399 * mark [6] free, increase bb_counters and shrink range to
1401 * Then shift range to [0; 2], go up and do the same.
1406 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1);
1408 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1);
1413 if (first == last || !(buddy2 = mb_find_buddy(e4b, order, &max))) {
1414 mb_clear_bits(buddy, first, last - first + 1);
1415 e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1424 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1425 int first, int count)
1427 int left_is_free = 0;
1428 int right_is_free = 0;
1430 int last = first + count - 1;
1431 struct super_block *sb = e4b->bd_sb;
1433 if (WARN_ON(count == 0))
1435 BUG_ON(last >= (sb->s_blocksize << 3));
1436 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1437 /* Don't bother if the block group is corrupt. */
1438 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1441 mb_check_buddy(e4b);
1442 mb_free_blocks_double(inode, e4b, first, count);
1444 e4b->bd_info->bb_free += count;
1445 if (first < e4b->bd_info->bb_first_free)
1446 e4b->bd_info->bb_first_free = first;
1448 /* access memory sequentially: check left neighbour,
1449 * clear range and then check right neighbour
1452 left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap);
1453 block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count);
1454 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1455 right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap);
1457 if (unlikely(block != -1)) {
1458 struct ext4_sb_info *sbi = EXT4_SB(sb);
1459 ext4_fsblk_t blocknr;
1461 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
1462 blocknr += EXT4_C2B(EXT4_SB(sb), block);
1463 ext4_grp_locked_error(sb, e4b->bd_group,
1464 inode ? inode->i_ino : 0,
1466 "freeing already freed block "
1467 "(bit %u); block bitmap corrupt.",
1469 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))
1470 percpu_counter_sub(&sbi->s_freeclusters_counter,
1471 e4b->bd_info->bb_free);
1472 /* Mark the block group as corrupt. */
1473 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1474 &e4b->bd_info->bb_state);
1475 mb_regenerate_buddy(e4b);
1479 /* let's maintain fragments counter */
1480 if (left_is_free && right_is_free)
1481 e4b->bd_info->bb_fragments--;
1482 else if (!left_is_free && !right_is_free)
1483 e4b->bd_info->bb_fragments++;
1485 /* buddy[0] == bd_bitmap is a special case, so handle
1486 * it right away and let mb_buddy_mark_free stay free of
1487 * zero order checks.
1488 * Check if neighbours are to be coaleasced,
1489 * adjust bitmap bb_counters and borders appropriately.
1492 first += !left_is_free;
1493 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
1496 last -= !right_is_free;
1497 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
1501 mb_buddy_mark_free(e4b, first >> 1, last >> 1);
1504 mb_set_largest_free_order(sb, e4b->bd_info);
1505 mb_check_buddy(e4b);
1508 static int mb_find_extent(struct ext4_buddy *e4b, int block,
1509 int needed, struct ext4_free_extent *ex)
1515 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1518 buddy = mb_find_buddy(e4b, 0, &max);
1519 BUG_ON(buddy == NULL);
1520 BUG_ON(block >= max);
1521 if (mb_test_bit(block, buddy)) {
1528 /* find actual order */
1529 order = mb_find_order_for_block(e4b, block);
1530 block = block >> order;
1532 ex->fe_len = 1 << order;
1533 ex->fe_start = block << order;
1534 ex->fe_group = e4b->bd_group;
1536 /* calc difference from given start */
1537 next = next - ex->fe_start;
1539 ex->fe_start += next;
1541 while (needed > ex->fe_len &&
1542 mb_find_buddy(e4b, order, &max)) {
1544 if (block + 1 >= max)
1547 next = (block + 1) * (1 << order);
1548 if (mb_test_bit(next, e4b->bd_bitmap))
1551 order = mb_find_order_for_block(e4b, next);
1553 block = next >> order;
1554 ex->fe_len += 1 << order;
1557 if (ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3))) {
1558 /* Should never happen! (but apparently sometimes does?!?) */
1560 ext4_error(e4b->bd_sb, "corruption or bug in mb_find_extent "
1561 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
1562 block, order, needed, ex->fe_group, ex->fe_start,
1563 ex->fe_len, ex->fe_logical);
1571 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1577 int start = ex->fe_start;
1578 int len = ex->fe_len;
1583 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1584 BUG_ON(e4b->bd_group != ex->fe_group);
1585 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1586 mb_check_buddy(e4b);
1587 mb_mark_used_double(e4b, start, len);
1589 e4b->bd_info->bb_free -= len;
1590 if (e4b->bd_info->bb_first_free == start)
1591 e4b->bd_info->bb_first_free += len;
1593 /* let's maintain fragments counter */
1595 mlen = !mb_test_bit(start - 1, e4b->bd_bitmap);
1596 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1597 max = !mb_test_bit(start + len, e4b->bd_bitmap);
1599 e4b->bd_info->bb_fragments++;
1600 else if (!mlen && !max)
1601 e4b->bd_info->bb_fragments--;
1603 /* let's maintain buddy itself */
1605 ord = mb_find_order_for_block(e4b, start);
1607 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1608 /* the whole chunk may be allocated at once! */
1610 buddy = mb_find_buddy(e4b, ord, &max);
1611 BUG_ON((start >> ord) >= max);
1612 mb_set_bit(start >> ord, buddy);
1613 e4b->bd_info->bb_counters[ord]--;
1620 /* store for history */
1622 ret = len | (ord << 16);
1624 /* we have to split large buddy */
1626 buddy = mb_find_buddy(e4b, ord, &max);
1627 mb_set_bit(start >> ord, buddy);
1628 e4b->bd_info->bb_counters[ord]--;
1631 cur = (start >> ord) & ~1U;
1632 buddy = mb_find_buddy(e4b, ord, &max);
1633 mb_clear_bit(cur, buddy);
1634 mb_clear_bit(cur + 1, buddy);
1635 e4b->bd_info->bb_counters[ord]++;
1636 e4b->bd_info->bb_counters[ord]++;
1638 mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
1640 ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
1641 mb_check_buddy(e4b);
1647 * Must be called under group lock!
1649 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1650 struct ext4_buddy *e4b)
1652 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1655 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1656 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1658 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1659 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1660 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1662 /* preallocation can change ac_b_ex, thus we store actually
1663 * allocated blocks for history */
1664 ac->ac_f_ex = ac->ac_b_ex;
1666 ac->ac_status = AC_STATUS_FOUND;
1667 ac->ac_tail = ret & 0xffff;
1668 ac->ac_buddy = ret >> 16;
1671 * take the page reference. We want the page to be pinned
1672 * so that we don't get a ext4_mb_init_cache_call for this
1673 * group until we update the bitmap. That would mean we
1674 * double allocate blocks. The reference is dropped
1675 * in ext4_mb_release_context
1677 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1678 get_page(ac->ac_bitmap_page);
1679 ac->ac_buddy_page = e4b->bd_buddy_page;
1680 get_page(ac->ac_buddy_page);
1681 /* store last allocated for subsequent stream allocation */
1682 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
1683 spin_lock(&sbi->s_md_lock);
1684 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1685 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1686 spin_unlock(&sbi->s_md_lock);
1691 * regular allocator, for general purposes allocation
1694 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1695 struct ext4_buddy *e4b,
1698 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1699 struct ext4_free_extent *bex = &ac->ac_b_ex;
1700 struct ext4_free_extent *gex = &ac->ac_g_ex;
1701 struct ext4_free_extent ex;
1704 if (ac->ac_status == AC_STATUS_FOUND)
1707 * We don't want to scan for a whole year
1709 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1710 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1711 ac->ac_status = AC_STATUS_BREAK;
1716 * Haven't found good chunk so far, let's continue
1718 if (bex->fe_len < gex->fe_len)
1721 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1722 && bex->fe_group == e4b->bd_group) {
1723 /* recheck chunk's availability - we don't know
1724 * when it was found (within this lock-unlock
1726 max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex);
1727 if (max >= gex->fe_len) {
1728 ext4_mb_use_best_found(ac, e4b);
1735 * The routine checks whether found extent is good enough. If it is,
1736 * then the extent gets marked used and flag is set to the context
1737 * to stop scanning. Otherwise, the extent is compared with the
1738 * previous found extent and if new one is better, then it's stored
1739 * in the context. Later, the best found extent will be used, if
1740 * mballoc can't find good enough extent.
1742 * FIXME: real allocation policy is to be designed yet!
1744 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1745 struct ext4_free_extent *ex,
1746 struct ext4_buddy *e4b)
1748 struct ext4_free_extent *bex = &ac->ac_b_ex;
1749 struct ext4_free_extent *gex = &ac->ac_g_ex;
1751 BUG_ON(ex->fe_len <= 0);
1752 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1753 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1754 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1759 * The special case - take what you catch first
1761 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1763 ext4_mb_use_best_found(ac, e4b);
1768 * Let's check whether the chuck is good enough
1770 if (ex->fe_len == gex->fe_len) {
1772 ext4_mb_use_best_found(ac, e4b);
1777 * If this is first found extent, just store it in the context
1779 if (bex->fe_len == 0) {
1785 * If new found extent is better, store it in the context
1787 if (bex->fe_len < gex->fe_len) {
1788 /* if the request isn't satisfied, any found extent
1789 * larger than previous best one is better */
1790 if (ex->fe_len > bex->fe_len)
1792 } else if (ex->fe_len > gex->fe_len) {
1793 /* if the request is satisfied, then we try to find
1794 * an extent that still satisfy the request, but is
1795 * smaller than previous one */
1796 if (ex->fe_len < bex->fe_len)
1800 ext4_mb_check_limits(ac, e4b, 0);
1803 static noinline_for_stack
1804 int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1805 struct ext4_buddy *e4b)
1807 struct ext4_free_extent ex = ac->ac_b_ex;
1808 ext4_group_t group = ex.fe_group;
1812 BUG_ON(ex.fe_len <= 0);
1813 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1817 ext4_lock_group(ac->ac_sb, group);
1818 max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex);
1822 ext4_mb_use_best_found(ac, e4b);
1825 ext4_unlock_group(ac->ac_sb, group);
1826 ext4_mb_unload_buddy(e4b);
1831 static noinline_for_stack
1832 int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1833 struct ext4_buddy *e4b)
1835 ext4_group_t group = ac->ac_g_ex.fe_group;
1838 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1839 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1840 struct ext4_free_extent ex;
1842 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1844 if (grp->bb_free == 0)
1847 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1851 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) {
1852 ext4_mb_unload_buddy(e4b);
1856 ext4_lock_group(ac->ac_sb, group);
1857 max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
1858 ac->ac_g_ex.fe_len, &ex);
1859 ex.fe_logical = 0xDEADFA11; /* debug value */
1861 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1864 start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) +
1866 /* use do_div to get remainder (would be 64-bit modulo) */
1867 if (do_div(start, sbi->s_stripe) == 0) {
1870 ext4_mb_use_best_found(ac, e4b);
1872 } else if (max >= ac->ac_g_ex.fe_len) {
1873 BUG_ON(ex.fe_len <= 0);
1874 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1875 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1878 ext4_mb_use_best_found(ac, e4b);
1879 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1880 /* Sometimes, caller may want to merge even small
1881 * number of blocks to an existing extent */
1882 BUG_ON(ex.fe_len <= 0);
1883 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1884 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1887 ext4_mb_use_best_found(ac, e4b);
1889 ext4_unlock_group(ac->ac_sb, group);
1890 ext4_mb_unload_buddy(e4b);
1896 * The routine scans buddy structures (not bitmap!) from given order
1897 * to max order and tries to find big enough chunk to satisfy the req
1899 static noinline_for_stack
1900 void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1901 struct ext4_buddy *e4b)
1903 struct super_block *sb = ac->ac_sb;
1904 struct ext4_group_info *grp = e4b->bd_info;
1910 BUG_ON(ac->ac_2order <= 0);
1911 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1912 if (grp->bb_counters[i] == 0)
1915 buddy = mb_find_buddy(e4b, i, &max);
1916 BUG_ON(buddy == NULL);
1918 k = mb_find_next_zero_bit(buddy, max, 0);
1923 ac->ac_b_ex.fe_len = 1 << i;
1924 ac->ac_b_ex.fe_start = k << i;
1925 ac->ac_b_ex.fe_group = e4b->bd_group;
1927 ext4_mb_use_best_found(ac, e4b);
1929 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1931 if (EXT4_SB(sb)->s_mb_stats)
1932 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1939 * The routine scans the group and measures all found extents.
1940 * In order to optimize scanning, caller must pass number of
1941 * free blocks in the group, so the routine can know upper limit.
1943 static noinline_for_stack
1944 void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1945 struct ext4_buddy *e4b)
1947 struct super_block *sb = ac->ac_sb;
1948 void *bitmap = e4b->bd_bitmap;
1949 struct ext4_free_extent ex;
1953 free = e4b->bd_info->bb_free;
1956 i = e4b->bd_info->bb_first_free;
1958 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
1959 i = mb_find_next_zero_bit(bitmap,
1960 EXT4_CLUSTERS_PER_GROUP(sb), i);
1961 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
1963 * IF we have corrupt bitmap, we won't find any
1964 * free blocks even though group info says we
1965 * we have free blocks
1967 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
1968 "%d free clusters as per "
1969 "group info. But bitmap says 0",
1974 mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex);
1975 BUG_ON(ex.fe_len <= 0);
1976 if (free < ex.fe_len) {
1977 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
1978 "%d free clusters as per "
1979 "group info. But got %d blocks",
1982 * The number of free blocks differs. This mostly
1983 * indicate that the bitmap is corrupt. So exit
1984 * without claiming the space.
1988 ex.fe_logical = 0xDEADC0DE; /* debug value */
1989 ext4_mb_measure_extent(ac, &ex, e4b);
1995 ext4_mb_check_limits(ac, e4b, 1);
1999 * This is a special case for storages like raid5
2000 * we try to find stripe-aligned chunks for stripe-size-multiple requests
2002 static noinline_for_stack
2003 void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
2004 struct ext4_buddy *e4b)
2006 struct super_block *sb = ac->ac_sb;
2007 struct ext4_sb_info *sbi = EXT4_SB(sb);
2008 void *bitmap = e4b->bd_bitmap;
2009 struct ext4_free_extent ex;
2010 ext4_fsblk_t first_group_block;
2015 BUG_ON(sbi->s_stripe == 0);
2017 /* find first stripe-aligned block in group */
2018 first_group_block = ext4_group_first_block_no(sb, e4b->bd_group);
2020 a = first_group_block + sbi->s_stripe - 1;
2021 do_div(a, sbi->s_stripe);
2022 i = (a * sbi->s_stripe) - first_group_block;
2024 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2025 if (!mb_test_bit(i, bitmap)) {
2026 max = mb_find_extent(e4b, i, sbi->s_stripe, &ex);
2027 if (max >= sbi->s_stripe) {
2029 ex.fe_logical = 0xDEADF00D; /* debug value */
2031 ext4_mb_use_best_found(ac, e4b);
2040 * This is now called BEFORE we load the buddy bitmap.
2041 * Returns either 1 or 0 indicating that the group is either suitable
2042 * for the allocation or not. In addition it can also return negative
2043 * error code when something goes wrong.
2045 static int ext4_mb_good_group(struct ext4_allocation_context *ac,
2046 ext4_group_t group, int cr)
2048 unsigned free, fragments;
2049 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
2050 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2052 BUG_ON(cr < 0 || cr >= 4);
2054 free = grp->bb_free;
2057 if (cr <= 2 && free < ac->ac_g_ex.fe_len)
2060 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2063 /* We only do this if the grp has never been initialized */
2064 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2065 int ret = ext4_mb_init_group(ac->ac_sb, group, GFP_NOFS);
2070 fragments = grp->bb_fragments;
2076 BUG_ON(ac->ac_2order == 0);
2078 /* Avoid using the first bg of a flexgroup for data files */
2079 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2080 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2081 ((group % flex_size) == 0))
2084 if ((ac->ac_2order > ac->ac_sb->s_blocksize_bits+1) ||
2085 (free / fragments) >= ac->ac_g_ex.fe_len)
2088 if (grp->bb_largest_free_order < ac->ac_2order)
2093 if ((free / fragments) >= ac->ac_g_ex.fe_len)
2097 if (free >= ac->ac_g_ex.fe_len)
2109 static noinline_for_stack int
2110 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2112 ext4_group_t ngroups, group, i;
2114 int err = 0, first_err = 0;
2115 struct ext4_sb_info *sbi;
2116 struct super_block *sb;
2117 struct ext4_buddy e4b;
2121 ngroups = ext4_get_groups_count(sb);
2122 /* non-extent files are limited to low blocks/groups */
2123 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)))
2124 ngroups = sbi->s_blockfile_groups;
2126 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2128 /* first, try the goal */
2129 err = ext4_mb_find_by_goal(ac, &e4b);
2130 if (err || ac->ac_status == AC_STATUS_FOUND)
2133 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2137 * ac->ac2_order is set only if the fe_len is a power of 2
2138 * if ac2_order is set we also set criteria to 0 so that we
2139 * try exact allocation using buddy.
2141 i = fls(ac->ac_g_ex.fe_len);
2144 * We search using buddy data only if the order of the request
2145 * is greater than equal to the sbi_s_mb_order2_reqs
2146 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2147 * We also support searching for power-of-two requests only for
2148 * requests upto maximum buddy size we have constructed.
2150 if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
2152 * This should tell if fe_len is exactly power of 2
2154 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
2155 ac->ac_2order = i - 1;
2158 /* if stream allocation is enabled, use global goal */
2159 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2160 /* TBD: may be hot point */
2161 spin_lock(&sbi->s_md_lock);
2162 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2163 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2164 spin_unlock(&sbi->s_md_lock);
2167 /* Let's just scan groups to find more-less suitable blocks */
2168 cr = ac->ac_2order ? 0 : 1;
2170 * cr == 0 try to get exact allocation,
2171 * cr == 3 try to get anything
2174 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2175 ac->ac_criteria = cr;
2177 * searching for the right group start
2178 * from the goal value specified
2180 group = ac->ac_g_ex.fe_group;
2182 for (i = 0; i < ngroups; group++, i++) {
2186 * Artificially restricted ngroups for non-extent
2187 * files makes group > ngroups possible on first loop.
2189 if (group >= ngroups)
2192 /* This now checks without needing the buddy page */
2193 ret = ext4_mb_good_group(ac, group, cr);
2200 err = ext4_mb_load_buddy(sb, group, &e4b);
2204 ext4_lock_group(sb, group);
2207 * We need to check again after locking the
2210 ret = ext4_mb_good_group(ac, group, cr);
2212 ext4_unlock_group(sb, group);
2213 ext4_mb_unload_buddy(&e4b);
2219 ac->ac_groups_scanned++;
2221 ext4_mb_simple_scan_group(ac, &e4b);
2222 else if (cr == 1 && sbi->s_stripe &&
2223 !(ac->ac_g_ex.fe_len % sbi->s_stripe))
2224 ext4_mb_scan_aligned(ac, &e4b);
2226 ext4_mb_complex_scan_group(ac, &e4b);
2228 ext4_unlock_group(sb, group);
2229 ext4_mb_unload_buddy(&e4b);
2231 if (ac->ac_status != AC_STATUS_CONTINUE)
2236 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2237 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2239 * We've been searching too long. Let's try to allocate
2240 * the best chunk we've found so far
2243 ext4_mb_try_best_found(ac, &e4b);
2244 if (ac->ac_status != AC_STATUS_FOUND) {
2246 * Someone more lucky has already allocated it.
2247 * The only thing we can do is just take first
2249 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2251 ac->ac_b_ex.fe_group = 0;
2252 ac->ac_b_ex.fe_start = 0;
2253 ac->ac_b_ex.fe_len = 0;
2254 ac->ac_status = AC_STATUS_CONTINUE;
2255 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2257 atomic_inc(&sbi->s_mb_lost_chunks);
2262 if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
2267 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2269 struct super_block *sb = seq->private;
2272 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2275 return (void *) ((unsigned long) group);
2278 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2280 struct super_block *sb = seq->private;
2284 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2287 return (void *) ((unsigned long) group);
2290 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2292 struct super_block *sb = seq->private;
2293 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
2295 int err, buddy_loaded = 0;
2296 struct ext4_buddy e4b;
2297 struct ext4_group_info *grinfo;
2299 struct ext4_group_info info;
2300 ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
2305 seq_puts(seq, "#group: free frags first ["
2306 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
2307 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
2309 i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2310 sizeof(struct ext4_group_info);
2311 grinfo = ext4_get_group_info(sb, group);
2312 /* Load the group info in memory only if not already loaded. */
2313 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
2314 err = ext4_mb_load_buddy(sb, group, &e4b);
2316 seq_printf(seq, "#%-5u: I/O error\n", group);
2322 memcpy(&sg, ext4_get_group_info(sb, group), i);
2325 ext4_mb_unload_buddy(&e4b);
2327 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
2328 sg.info.bb_fragments, sg.info.bb_first_free);
2329 for (i = 0; i <= 13; i++)
2330 seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ?
2331 sg.info.bb_counters[i] : 0);
2332 seq_printf(seq, " ]\n");
2337 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2341 static const struct seq_operations ext4_mb_seq_groups_ops = {
2342 .start = ext4_mb_seq_groups_start,
2343 .next = ext4_mb_seq_groups_next,
2344 .stop = ext4_mb_seq_groups_stop,
2345 .show = ext4_mb_seq_groups_show,
2348 static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
2350 struct super_block *sb = PDE_DATA(inode);
2353 rc = seq_open(file, &ext4_mb_seq_groups_ops);
2355 struct seq_file *m = file->private_data;
2362 const struct file_operations ext4_seq_mb_groups_fops = {
2363 .open = ext4_mb_seq_groups_open,
2365 .llseek = seq_lseek,
2366 .release = seq_release,
2369 static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
2371 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2372 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
2379 * Allocate the top-level s_group_info array for the specified number
2382 int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
2384 struct ext4_sb_info *sbi = EXT4_SB(sb);
2386 struct ext4_group_info ***new_groupinfo;
2388 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
2389 EXT4_DESC_PER_BLOCK_BITS(sb);
2390 if (size <= sbi->s_group_info_size)
2393 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
2394 new_groupinfo = kvzalloc(size, GFP_KERNEL);
2395 if (!new_groupinfo) {
2396 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
2399 if (sbi->s_group_info) {
2400 memcpy(new_groupinfo, sbi->s_group_info,
2401 sbi->s_group_info_size * sizeof(*sbi->s_group_info));
2402 kvfree(sbi->s_group_info);
2404 sbi->s_group_info = new_groupinfo;
2405 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
2406 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2407 sbi->s_group_info_size);
2411 /* Create and initialize ext4_group_info data for the given group. */
2412 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
2413 struct ext4_group_desc *desc)
2417 struct ext4_sb_info *sbi = EXT4_SB(sb);
2418 struct ext4_group_info **meta_group_info;
2419 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2422 * First check if this group is the first of a reserved block.
2423 * If it's true, we have to allocate a new table of pointers
2424 * to ext4_group_info structures
2426 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2427 metalen = sizeof(*meta_group_info) <<
2428 EXT4_DESC_PER_BLOCK_BITS(sb);
2429 meta_group_info = kmalloc(metalen, GFP_NOFS);
2430 if (meta_group_info == NULL) {
2431 ext4_msg(sb, KERN_ERR, "can't allocate mem "
2432 "for a buddy group");
2433 goto exit_meta_group_info;
2435 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] =
2440 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
2441 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
2443 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
2444 if (meta_group_info[i] == NULL) {
2445 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
2446 goto exit_group_info;
2448 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2449 &(meta_group_info[i]->bb_state));
2452 * initialize bb_free to be able to skip
2453 * empty groups without initialization
2455 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2456 meta_group_info[i]->bb_free =
2457 ext4_free_clusters_after_init(sb, group, desc);
2459 meta_group_info[i]->bb_free =
2460 ext4_free_group_clusters(sb, desc);
2463 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
2464 init_rwsem(&meta_group_info[i]->alloc_sem);
2465 meta_group_info[i]->bb_free_root = RB_ROOT;
2466 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
2470 struct buffer_head *bh;
2471 meta_group_info[i]->bb_bitmap =
2472 kmalloc(sb->s_blocksize, GFP_NOFS);
2473 BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
2474 bh = ext4_read_block_bitmap(sb, group);
2475 BUG_ON(IS_ERR_OR_NULL(bh));
2476 memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
2485 /* If a meta_group_info table has been allocated, release it now */
2486 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2487 kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
2488 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] = NULL;
2490 exit_meta_group_info:
2492 } /* ext4_mb_add_groupinfo */
2494 static int ext4_mb_init_backend(struct super_block *sb)
2496 ext4_group_t ngroups = ext4_get_groups_count(sb);
2498 struct ext4_sb_info *sbi = EXT4_SB(sb);
2500 struct ext4_group_desc *desc;
2501 struct kmem_cache *cachep;
2503 err = ext4_mb_alloc_groupinfo(sb, ngroups);
2507 sbi->s_buddy_cache = new_inode(sb);
2508 if (sbi->s_buddy_cache == NULL) {
2509 ext4_msg(sb, KERN_ERR, "can't get new inode");
2512 /* To avoid potentially colliding with an valid on-disk inode number,
2513 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2514 * not in the inode hash, so it should never be found by iget(), but
2515 * this will avoid confusion if it ever shows up during debugging. */
2516 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
2517 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2518 for (i = 0; i < ngroups; i++) {
2519 desc = ext4_get_group_desc(sb, i, NULL);
2521 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
2524 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
2531 cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2533 kmem_cache_free(cachep, ext4_get_group_info(sb, i));
2534 i = sbi->s_group_info_size;
2536 kfree(sbi->s_group_info[i]);
2537 iput(sbi->s_buddy_cache);
2539 kvfree(sbi->s_group_info);
2543 static void ext4_groupinfo_destroy_slabs(void)
2547 for (i = 0; i < NR_GRPINFO_CACHES; i++) {
2548 if (ext4_groupinfo_caches[i])
2549 kmem_cache_destroy(ext4_groupinfo_caches[i]);
2550 ext4_groupinfo_caches[i] = NULL;
2554 static int ext4_groupinfo_create_slab(size_t size)
2556 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
2558 int blocksize_bits = order_base_2(size);
2559 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2560 struct kmem_cache *cachep;
2562 if (cache_index >= NR_GRPINFO_CACHES)
2565 if (unlikely(cache_index < 0))
2568 mutex_lock(&ext4_grpinfo_slab_create_mutex);
2569 if (ext4_groupinfo_caches[cache_index]) {
2570 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2571 return 0; /* Already created */
2574 slab_size = offsetof(struct ext4_group_info,
2575 bb_counters[blocksize_bits + 2]);
2577 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
2578 slab_size, 0, SLAB_RECLAIM_ACCOUNT,
2581 ext4_groupinfo_caches[cache_index] = cachep;
2583 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2586 "EXT4-fs: no memory for groupinfo slab cache\n");
2593 int ext4_mb_init(struct super_block *sb)
2595 struct ext4_sb_info *sbi = EXT4_SB(sb);
2597 unsigned offset, offset_incr;
2601 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
2603 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2604 if (sbi->s_mb_offsets == NULL) {
2609 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
2610 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2611 if (sbi->s_mb_maxs == NULL) {
2616 ret = ext4_groupinfo_create_slab(sb->s_blocksize);
2620 /* order 0 is regular bitmap */
2621 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2622 sbi->s_mb_offsets[0] = 0;
2626 offset_incr = 1 << (sb->s_blocksize_bits - 1);
2627 max = sb->s_blocksize << 2;
2629 sbi->s_mb_offsets[i] = offset;
2630 sbi->s_mb_maxs[i] = max;
2631 offset += offset_incr;
2632 offset_incr = offset_incr >> 1;
2635 } while (i <= sb->s_blocksize_bits + 1);
2637 spin_lock_init(&sbi->s_md_lock);
2638 spin_lock_init(&sbi->s_bal_lock);
2639 sbi->s_mb_free_pending = 0;
2640 INIT_LIST_HEAD(&sbi->s_freed_data_list);
2642 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2643 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2644 sbi->s_mb_stats = MB_DEFAULT_STATS;
2645 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2646 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2648 * The default group preallocation is 512, which for 4k block
2649 * sizes translates to 2 megabytes. However for bigalloc file
2650 * systems, this is probably too big (i.e, if the cluster size
2651 * is 1 megabyte, then group preallocation size becomes half a
2652 * gigabyte!). As a default, we will keep a two megabyte
2653 * group pralloc size for cluster sizes up to 64k, and after
2654 * that, we will force a minimum group preallocation size of
2655 * 32 clusters. This translates to 8 megs when the cluster
2656 * size is 256k, and 32 megs when the cluster size is 1 meg,
2657 * which seems reasonable as a default.
2659 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
2660 sbi->s_cluster_bits, 32);
2662 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2663 * to the lowest multiple of s_stripe which is bigger than
2664 * the s_mb_group_prealloc as determined above. We want
2665 * the preallocation size to be an exact multiple of the
2666 * RAID stripe size so that preallocations don't fragment
2669 if (sbi->s_stripe > 1) {
2670 sbi->s_mb_group_prealloc = roundup(
2671 sbi->s_mb_group_prealloc, sbi->s_stripe);
2674 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
2675 if (sbi->s_locality_groups == NULL) {
2679 for_each_possible_cpu(i) {
2680 struct ext4_locality_group *lg;
2681 lg = per_cpu_ptr(sbi->s_locality_groups, i);
2682 mutex_init(&lg->lg_mutex);
2683 for (j = 0; j < PREALLOC_TB_SIZE; j++)
2684 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
2685 spin_lock_init(&lg->lg_prealloc_lock);
2688 /* init file for buddy data */
2689 ret = ext4_mb_init_backend(sb);
2691 goto out_free_locality_groups;
2695 out_free_locality_groups:
2696 free_percpu(sbi->s_locality_groups);
2697 sbi->s_locality_groups = NULL;
2699 kfree(sbi->s_mb_offsets);
2700 sbi->s_mb_offsets = NULL;
2701 kfree(sbi->s_mb_maxs);
2702 sbi->s_mb_maxs = NULL;
2706 /* need to called with the ext4 group lock held */
2707 static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2709 struct ext4_prealloc_space *pa;
2710 struct list_head *cur, *tmp;
2713 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2714 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2715 list_del(&pa->pa_group_list);
2717 kmem_cache_free(ext4_pspace_cachep, pa);
2720 mb_debug(1, "mballoc: %u PAs left\n", count);
2724 int ext4_mb_release(struct super_block *sb)
2726 ext4_group_t ngroups = ext4_get_groups_count(sb);
2728 int num_meta_group_infos;
2729 struct ext4_group_info *grinfo;
2730 struct ext4_sb_info *sbi = EXT4_SB(sb);
2731 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2733 if (sbi->s_group_info) {
2734 for (i = 0; i < ngroups; i++) {
2735 grinfo = ext4_get_group_info(sb, i);
2737 kfree(grinfo->bb_bitmap);
2739 ext4_lock_group(sb, i);
2740 ext4_mb_cleanup_pa(grinfo);
2741 ext4_unlock_group(sb, i);
2742 kmem_cache_free(cachep, grinfo);
2744 num_meta_group_infos = (ngroups +
2745 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2746 EXT4_DESC_PER_BLOCK_BITS(sb);
2747 for (i = 0; i < num_meta_group_infos; i++)
2748 kfree(sbi->s_group_info[i]);
2749 kvfree(sbi->s_group_info);
2751 kfree(sbi->s_mb_offsets);
2752 kfree(sbi->s_mb_maxs);
2753 iput(sbi->s_buddy_cache);
2754 if (sbi->s_mb_stats) {
2755 ext4_msg(sb, KERN_INFO,
2756 "mballoc: %u blocks %u reqs (%u success)",
2757 atomic_read(&sbi->s_bal_allocated),
2758 atomic_read(&sbi->s_bal_reqs),
2759 atomic_read(&sbi->s_bal_success));
2760 ext4_msg(sb, KERN_INFO,
2761 "mballoc: %u extents scanned, %u goal hits, "
2762 "%u 2^N hits, %u breaks, %u lost",
2763 atomic_read(&sbi->s_bal_ex_scanned),
2764 atomic_read(&sbi->s_bal_goals),
2765 atomic_read(&sbi->s_bal_2orders),
2766 atomic_read(&sbi->s_bal_breaks),
2767 atomic_read(&sbi->s_mb_lost_chunks));
2768 ext4_msg(sb, KERN_INFO,
2769 "mballoc: %lu generated and it took %Lu",
2770 sbi->s_mb_buddies_generated,
2771 sbi->s_mb_generation_time);
2772 ext4_msg(sb, KERN_INFO,
2773 "mballoc: %u preallocated, %u discarded",
2774 atomic_read(&sbi->s_mb_preallocated),
2775 atomic_read(&sbi->s_mb_discarded));
2778 free_percpu(sbi->s_locality_groups);
2783 static inline int ext4_issue_discard(struct super_block *sb,
2784 ext4_group_t block_group, ext4_grpblk_t cluster, int count,
2787 ext4_fsblk_t discard_block;
2789 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
2790 ext4_group_first_block_no(sb, block_group));
2791 count = EXT4_C2B(EXT4_SB(sb), count);
2792 trace_ext4_discard_blocks(sb,
2793 (unsigned long long) discard_block, count);
2795 return __blkdev_issue_discard(sb->s_bdev,
2796 (sector_t)discard_block << (sb->s_blocksize_bits - 9),
2797 (sector_t)count << (sb->s_blocksize_bits - 9),
2800 return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
2803 static void ext4_free_data_in_buddy(struct super_block *sb,
2804 struct ext4_free_data *entry)
2806 struct ext4_buddy e4b;
2807 struct ext4_group_info *db;
2808 int err, count = 0, count2 = 0;
2810 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2811 entry->efd_count, entry->efd_group, entry);
2813 err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
2814 /* we expect to find existing buddy because it's pinned */
2817 spin_lock(&EXT4_SB(sb)->s_md_lock);
2818 EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
2819 spin_unlock(&EXT4_SB(sb)->s_md_lock);
2822 /* there are blocks to put in buddy to make them really free */
2823 count += entry->efd_count;
2825 ext4_lock_group(sb, entry->efd_group);
2826 /* Take it out of per group rb tree */
2827 rb_erase(&entry->efd_node, &(db->bb_free_root));
2828 mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count);
2831 * Clear the trimmed flag for the group so that the next
2832 * ext4_trim_fs can trim it.
2833 * If the volume is mounted with -o discard, online discard
2834 * is supported and the free blocks will be trimmed online.
2836 if (!test_opt(sb, DISCARD))
2837 EXT4_MB_GRP_CLEAR_TRIMMED(db);
2839 if (!db->bb_free_root.rb_node) {
2840 /* No more items in the per group rb tree
2841 * balance refcounts from ext4_mb_free_metadata()
2843 put_page(e4b.bd_buddy_page);
2844 put_page(e4b.bd_bitmap_page);
2846 ext4_unlock_group(sb, entry->efd_group);
2847 kmem_cache_free(ext4_free_data_cachep, entry);
2848 ext4_mb_unload_buddy(&e4b);
2850 mb_debug(1, "freed %u blocks in %u structures\n", count, count2);
2854 * This function is called by the jbd2 layer once the commit has finished,
2855 * so we know we can free the blocks that were released with that commit.
2857 void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
2859 struct ext4_sb_info *sbi = EXT4_SB(sb);
2860 struct ext4_free_data *entry, *tmp;
2861 struct bio *discard_bio = NULL;
2862 struct list_head freed_data_list;
2863 struct list_head *cut_pos = NULL;
2866 INIT_LIST_HEAD(&freed_data_list);
2868 spin_lock(&sbi->s_md_lock);
2869 list_for_each_entry(entry, &sbi->s_freed_data_list, efd_list) {
2870 if (entry->efd_tid != commit_tid)
2872 cut_pos = &entry->efd_list;
2875 list_cut_position(&freed_data_list, &sbi->s_freed_data_list,
2877 spin_unlock(&sbi->s_md_lock);
2879 if (test_opt(sb, DISCARD)) {
2880 list_for_each_entry(entry, &freed_data_list, efd_list) {
2881 err = ext4_issue_discard(sb, entry->efd_group,
2882 entry->efd_start_cluster,
2885 if (err && err != -EOPNOTSUPP) {
2886 ext4_msg(sb, KERN_WARNING, "discard request in"
2887 " group:%d block:%d count:%d failed"
2888 " with %d", entry->efd_group,
2889 entry->efd_start_cluster,
2890 entry->efd_count, err);
2891 } else if (err == -EOPNOTSUPP)
2896 submit_bio_wait(discard_bio);
2899 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
2900 ext4_free_data_in_buddy(sb, entry);
2903 int __init ext4_init_mballoc(void)
2905 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
2906 SLAB_RECLAIM_ACCOUNT);
2907 if (ext4_pspace_cachep == NULL)
2910 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
2911 SLAB_RECLAIM_ACCOUNT);
2912 if (ext4_ac_cachep == NULL) {
2913 kmem_cache_destroy(ext4_pspace_cachep);
2917 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
2918 SLAB_RECLAIM_ACCOUNT);
2919 if (ext4_free_data_cachep == NULL) {
2920 kmem_cache_destroy(ext4_pspace_cachep);
2921 kmem_cache_destroy(ext4_ac_cachep);
2927 void ext4_exit_mballoc(void)
2930 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2931 * before destroying the slab cache.
2934 kmem_cache_destroy(ext4_pspace_cachep);
2935 kmem_cache_destroy(ext4_ac_cachep);
2936 kmem_cache_destroy(ext4_free_data_cachep);
2937 ext4_groupinfo_destroy_slabs();
2942 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2943 * Returns 0 if success or error code
2945 static noinline_for_stack int
2946 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
2947 handle_t *handle, unsigned int reserv_clstrs)
2949 struct buffer_head *bitmap_bh = NULL;
2950 struct ext4_group_desc *gdp;
2951 struct buffer_head *gdp_bh;
2952 struct ext4_sb_info *sbi;
2953 struct super_block *sb;
2957 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
2958 BUG_ON(ac->ac_b_ex.fe_len <= 0);
2963 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
2964 if (IS_ERR(bitmap_bh)) {
2965 err = PTR_ERR(bitmap_bh);
2970 BUFFER_TRACE(bitmap_bh, "getting write access");
2971 err = ext4_journal_get_write_access(handle, bitmap_bh);
2976 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
2980 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
2981 ext4_free_group_clusters(sb, gdp));
2983 BUFFER_TRACE(gdp_bh, "get_write_access");
2984 err = ext4_journal_get_write_access(handle, gdp_bh);
2988 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
2990 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
2991 if (!ext4_data_block_valid(sbi, block, len)) {
2992 ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
2993 "fs metadata", block, block+len);
2994 /* File system mounted not to panic on error
2995 * Fix the bitmap and return EFSCORRUPTED
2996 * We leak some of the blocks here.
2998 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
2999 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3000 ac->ac_b_ex.fe_len);
3001 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3002 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3004 err = -EFSCORRUPTED;
3008 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3009 #ifdef AGGRESSIVE_CHECK
3012 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3013 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3014 bitmap_bh->b_data));
3018 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3019 ac->ac_b_ex.fe_len);
3020 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
3021 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3022 ext4_free_group_clusters_set(sb, gdp,
3023 ext4_free_clusters_after_init(sb,
3024 ac->ac_b_ex.fe_group, gdp));
3026 len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
3027 ext4_free_group_clusters_set(sb, gdp, len);
3028 ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
3029 ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
3031 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3032 percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
3034 * Now reduce the dirty block count also. Should not go negative
3036 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
3037 /* release all the reserved blocks if non delalloc */
3038 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
3041 if (sbi->s_log_groups_per_flex) {
3042 ext4_group_t flex_group = ext4_flex_group(sbi,
3043 ac->ac_b_ex.fe_group);
3044 atomic64_sub(ac->ac_b_ex.fe_len,
3045 &sbi->s_flex_groups[flex_group].free_clusters);
3048 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3051 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
3059 * here we normalize request for locality group
3060 * Group request are normalized to s_mb_group_prealloc, which goes to
3061 * s_strip if we set the same via mount option.
3062 * s_mb_group_prealloc can be configured via
3063 * /sys/fs/ext4/<partition>/mb_group_prealloc
3065 * XXX: should we try to preallocate more than the group has now?
3067 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3069 struct super_block *sb = ac->ac_sb;
3070 struct ext4_locality_group *lg = ac->ac_lg;
3073 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3074 mb_debug(1, "#%u: goal %u blocks for locality group\n",
3075 current->pid, ac->ac_g_ex.fe_len);
3079 * Normalization means making request better in terms of
3080 * size and alignment
3082 static noinline_for_stack void
3083 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
3084 struct ext4_allocation_request *ar)
3086 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3089 loff_t size, start_off;
3090 loff_t orig_size __maybe_unused;
3092 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3093 struct ext4_prealloc_space *pa;
3095 /* do normalize only data requests, metadata requests
3096 do not need preallocation */
3097 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3100 /* sometime caller may want exact blocks */
3101 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3104 /* caller may indicate that preallocation isn't
3105 * required (it's a tail, for example) */
3106 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3109 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3110 ext4_mb_normalize_group_request(ac);
3114 bsbits = ac->ac_sb->s_blocksize_bits;
3116 /* first, let's learn actual file size
3117 * given current request is allocated */
3118 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
3119 size = size << bsbits;
3120 if (size < i_size_read(ac->ac_inode))
3121 size = i_size_read(ac->ac_inode);
3124 /* max size of free chunks */
3127 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3128 (req <= (size) || max <= (chunk_size))
3130 /* first, try to predict filesize */
3131 /* XXX: should this table be tunable? */
3133 if (size <= 16 * 1024) {
3135 } else if (size <= 32 * 1024) {
3137 } else if (size <= 64 * 1024) {
3139 } else if (size <= 128 * 1024) {
3141 } else if (size <= 256 * 1024) {
3143 } else if (size <= 512 * 1024) {
3145 } else if (size <= 1024 * 1024) {
3147 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
3148 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3149 (21 - bsbits)) << 21;
3150 size = 2 * 1024 * 1024;
3151 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
3152 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3153 (22 - bsbits)) << 22;
3154 size = 4 * 1024 * 1024;
3155 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3156 (8<<20)>>bsbits, max, 8 * 1024)) {
3157 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3158 (23 - bsbits)) << 23;
3159 size = 8 * 1024 * 1024;
3161 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
3162 size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
3163 ac->ac_o_ex.fe_len) << bsbits;
3165 size = size >> bsbits;
3166 start = start_off >> bsbits;
3168 /* don't cover already allocated blocks in selected range */
3169 if (ar->pleft && start <= ar->lleft) {
3170 size -= ar->lleft + 1 - start;
3171 start = ar->lleft + 1;
3173 if (ar->pright && start + size - 1 >= ar->lright)
3174 size -= start + size - ar->lright;
3177 * Trim allocation request for filesystems with artificially small
3180 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
3181 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
3185 /* check we don't cross already preallocated blocks */
3187 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3192 spin_lock(&pa->pa_lock);
3193 if (pa->pa_deleted) {
3194 spin_unlock(&pa->pa_lock);
3198 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3201 /* PA must not overlap original request */
3202 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3203 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3205 /* skip PAs this normalized request doesn't overlap with */
3206 if (pa->pa_lstart >= end || pa_end <= start) {
3207 spin_unlock(&pa->pa_lock);
3210 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3212 /* adjust start or end to be adjacent to this pa */
3213 if (pa_end <= ac->ac_o_ex.fe_logical) {
3214 BUG_ON(pa_end < start);
3216 } else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3217 BUG_ON(pa->pa_lstart > end);
3218 end = pa->pa_lstart;
3220 spin_unlock(&pa->pa_lock);
3225 /* XXX: extra loop to check we really don't overlap preallocations */
3227 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3230 spin_lock(&pa->pa_lock);
3231 if (pa->pa_deleted == 0) {
3232 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3234 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3236 spin_unlock(&pa->pa_lock);
3240 if (start + size <= ac->ac_o_ex.fe_logical &&
3241 start > ac->ac_o_ex.fe_logical) {
3242 ext4_msg(ac->ac_sb, KERN_ERR,
3243 "start %lu, size %lu, fe_logical %lu",
3244 (unsigned long) start, (unsigned long) size,
3245 (unsigned long) ac->ac_o_ex.fe_logical);
3248 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3250 /* now prepare goal request */
3252 /* XXX: is it better to align blocks WRT to logical
3253 * placement or satisfy big request as is */
3254 ac->ac_g_ex.fe_logical = start;
3255 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
3257 /* define goal start in order to merge */
3258 if (ar->pright && (ar->lright == (start + size))) {
3259 /* merge to the right */
3260 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3261 &ac->ac_f_ex.fe_group,
3262 &ac->ac_f_ex.fe_start);
3263 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3265 if (ar->pleft && (ar->lleft + 1 == start)) {
3266 /* merge to the left */
3267 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3268 &ac->ac_f_ex.fe_group,
3269 &ac->ac_f_ex.fe_start);
3270 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3273 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size,
3274 (unsigned) orig_size, (unsigned) start);
3277 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3279 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3281 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3282 atomic_inc(&sbi->s_bal_reqs);
3283 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3284 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
3285 atomic_inc(&sbi->s_bal_success);
3286 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3287 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3288 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3289 atomic_inc(&sbi->s_bal_goals);
3290 if (ac->ac_found > sbi->s_mb_max_to_scan)
3291 atomic_inc(&sbi->s_bal_breaks);
3294 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
3295 trace_ext4_mballoc_alloc(ac);
3297 trace_ext4_mballoc_prealloc(ac);
3301 * Called on failure; free up any blocks from the inode PA for this
3302 * context. We don't need this for MB_GROUP_PA because we only change
3303 * pa_free in ext4_mb_release_context(), but on failure, we've already
3304 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3306 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
3308 struct ext4_prealloc_space *pa = ac->ac_pa;
3309 struct ext4_buddy e4b;
3313 if (ac->ac_f_ex.fe_len == 0)
3315 err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
3318 * This should never happen since we pin the
3319 * pages in the ext4_allocation_context so
3320 * ext4_mb_load_buddy() should never fail.
3322 WARN(1, "mb_load_buddy failed (%d)", err);
3325 ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3326 mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
3327 ac->ac_f_ex.fe_len);
3328 ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3329 ext4_mb_unload_buddy(&e4b);
3332 if (pa->pa_type == MB_INODE_PA)
3333 pa->pa_free += ac->ac_b_ex.fe_len;
3337 * use blocks preallocated to inode
3339 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3340 struct ext4_prealloc_space *pa)
3342 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3347 /* found preallocated blocks, use them */
3348 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3349 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
3350 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
3351 len = EXT4_NUM_B2C(sbi, end - start);
3352 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3353 &ac->ac_b_ex.fe_start);
3354 ac->ac_b_ex.fe_len = len;
3355 ac->ac_status = AC_STATUS_FOUND;
3358 BUG_ON(start < pa->pa_pstart);
3359 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
3360 BUG_ON(pa->pa_free < len);
3363 mb_debug(1, "use %llu/%u from inode pa %p\n", start, len, pa);
3367 * use blocks preallocated to locality group
3369 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3370 struct ext4_prealloc_space *pa)
3372 unsigned int len = ac->ac_o_ex.fe_len;
3374 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3375 &ac->ac_b_ex.fe_group,
3376 &ac->ac_b_ex.fe_start);
3377 ac->ac_b_ex.fe_len = len;
3378 ac->ac_status = AC_STATUS_FOUND;
3381 /* we don't correct pa_pstart or pa_plen here to avoid
3382 * possible race when the group is being loaded concurrently
3383 * instead we correct pa later, after blocks are marked
3384 * in on-disk bitmap -- see ext4_mb_release_context()
3385 * Other CPUs are prevented from allocating from this pa by lg_mutex
3387 mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3391 * Return the prealloc space that have minimal distance
3392 * from the goal block. @cpa is the prealloc
3393 * space that is having currently known minimal distance
3394 * from the goal block.
3396 static struct ext4_prealloc_space *
3397 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
3398 struct ext4_prealloc_space *pa,
3399 struct ext4_prealloc_space *cpa)
3401 ext4_fsblk_t cur_distance, new_distance;
3404 atomic_inc(&pa->pa_count);
3407 cur_distance = abs(goal_block - cpa->pa_pstart);
3408 new_distance = abs(goal_block - pa->pa_pstart);
3410 if (cur_distance <= new_distance)
3413 /* drop the previous reference */
3414 atomic_dec(&cpa->pa_count);
3415 atomic_inc(&pa->pa_count);
3420 * search goal blocks in preallocated space
3422 static noinline_for_stack int
3423 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
3425 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3427 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3428 struct ext4_locality_group *lg;
3429 struct ext4_prealloc_space *pa, *cpa = NULL;
3430 ext4_fsblk_t goal_block;
3432 /* only data can be preallocated */
3433 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3436 /* first, try per-file preallocation */
3438 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3440 /* all fields in this condition don't change,
3441 * so we can skip locking for them */
3442 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3443 ac->ac_o_ex.fe_logical >= (pa->pa_lstart +
3444 EXT4_C2B(sbi, pa->pa_len)))
3447 /* non-extent files can't have physical blocks past 2^32 */
3448 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) &&
3449 (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) >
3450 EXT4_MAX_BLOCK_FILE_PHYS))
3453 /* found preallocated blocks, use them */
3454 spin_lock(&pa->pa_lock);
3455 if (pa->pa_deleted == 0 && pa->pa_free) {
3456 atomic_inc(&pa->pa_count);
3457 ext4_mb_use_inode_pa(ac, pa);
3458 spin_unlock(&pa->pa_lock);
3459 ac->ac_criteria = 10;
3463 spin_unlock(&pa->pa_lock);
3467 /* can we use group allocation? */
3468 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3471 /* inode may have no locality group for some reason */
3475 order = fls(ac->ac_o_ex.fe_len) - 1;
3476 if (order > PREALLOC_TB_SIZE - 1)
3477 /* The max size of hash table is PREALLOC_TB_SIZE */
3478 order = PREALLOC_TB_SIZE - 1;
3480 goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex);
3482 * search for the prealloc space that is having
3483 * minimal distance from the goal block.
3485 for (i = order; i < PREALLOC_TB_SIZE; i++) {
3487 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
3489 spin_lock(&pa->pa_lock);
3490 if (pa->pa_deleted == 0 &&
3491 pa->pa_free >= ac->ac_o_ex.fe_len) {
3493 cpa = ext4_mb_check_group_pa(goal_block,
3496 spin_unlock(&pa->pa_lock);
3501 ext4_mb_use_group_pa(ac, cpa);
3502 ac->ac_criteria = 20;
3509 * the function goes through all block freed in the group
3510 * but not yet committed and marks them used in in-core bitmap.
3511 * buddy must be generated from this bitmap
3512 * Need to be called with the ext4 group lock held
3514 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
3518 struct ext4_group_info *grp;
3519 struct ext4_free_data *entry;
3521 grp = ext4_get_group_info(sb, group);
3522 n = rb_first(&(grp->bb_free_root));
3525 entry = rb_entry(n, struct ext4_free_data, efd_node);
3526 ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count);
3533 * the function goes through all preallocation in this group and marks them
3534 * used in in-core bitmap. buddy must be generated from this bitmap
3535 * Need to be called with ext4 group lock held
3537 static noinline_for_stack
3538 void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3541 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3542 struct ext4_prealloc_space *pa;
3543 struct list_head *cur;
3544 ext4_group_t groupnr;
3545 ext4_grpblk_t start;
3546 int preallocated = 0;
3549 /* all form of preallocation discards first load group,
3550 * so the only competing code is preallocation use.
3551 * we don't need any locking here
3552 * notice we do NOT ignore preallocations with pa_deleted
3553 * otherwise we could leave used blocks available for
3554 * allocation in buddy when concurrent ext4_mb_put_pa()
3555 * is dropping preallocation
3557 list_for_each(cur, &grp->bb_prealloc_list) {
3558 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3559 spin_lock(&pa->pa_lock);
3560 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3563 spin_unlock(&pa->pa_lock);
3564 if (unlikely(len == 0))
3566 BUG_ON(groupnr != group);
3567 ext4_set_bits(bitmap, start, len);
3568 preallocated += len;
3570 mb_debug(1, "preallocated %u for group %u\n", preallocated, group);
3573 static void ext4_mb_pa_callback(struct rcu_head *head)
3575 struct ext4_prealloc_space *pa;
3576 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3578 BUG_ON(atomic_read(&pa->pa_count));
3579 BUG_ON(pa->pa_deleted == 0);
3580 kmem_cache_free(ext4_pspace_cachep, pa);
3584 * drops a reference to preallocated space descriptor
3585 * if this was the last reference and the space is consumed
3587 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3588 struct super_block *sb, struct ext4_prealloc_space *pa)
3591 ext4_fsblk_t grp_blk;
3593 /* in this short window concurrent discard can set pa_deleted */
3594 spin_lock(&pa->pa_lock);
3595 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {
3596 spin_unlock(&pa->pa_lock);
3600 if (pa->pa_deleted == 1) {
3601 spin_unlock(&pa->pa_lock);
3606 spin_unlock(&pa->pa_lock);
3608 grp_blk = pa->pa_pstart;
3610 * If doing group-based preallocation, pa_pstart may be in the
3611 * next group when pa is used up
3613 if (pa->pa_type == MB_GROUP_PA)
3616 grp = ext4_get_group_number(sb, grp_blk);
3621 * P1 (buddy init) P2 (regular allocation)
3622 * find block B in PA
3623 * copy on-disk bitmap to buddy
3624 * mark B in on-disk bitmap
3625 * drop PA from group
3626 * mark all PAs in buddy
3628 * thus, P1 initializes buddy with B available. to prevent this
3629 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3632 ext4_lock_group(sb, grp);
3633 list_del(&pa->pa_group_list);
3634 ext4_unlock_group(sb, grp);
3636 spin_lock(pa->pa_obj_lock);
3637 list_del_rcu(&pa->pa_inode_list);
3638 spin_unlock(pa->pa_obj_lock);
3640 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3644 * creates new preallocated space for given inode
3646 static noinline_for_stack int
3647 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
3649 struct super_block *sb = ac->ac_sb;
3650 struct ext4_sb_info *sbi = EXT4_SB(sb);
3651 struct ext4_prealloc_space *pa;
3652 struct ext4_group_info *grp;
3653 struct ext4_inode_info *ei;
3655 /* preallocate only when found space is larger then requested */
3656 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3657 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3658 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3660 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3664 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3670 /* we can't allocate as much as normalizer wants.
3671 * so, found space must get proper lstart
3672 * to cover original request */
3673 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3674 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3676 /* we're limited by original request in that
3677 * logical block must be covered any way
3678 * winl is window we can move our chunk within */
3679 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
3681 /* also, we should cover whole original request */
3682 wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len);
3684 /* the smallest one defines real window */
3685 win = min(winl, wins);
3687 offs = ac->ac_o_ex.fe_logical %
3688 EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
3689 if (offs && offs < win)
3692 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical -
3693 EXT4_NUM_B2C(sbi, win);
3694 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3695 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3698 /* preallocation can change ac_b_ex, thus we store actually
3699 * allocated blocks for history */
3700 ac->ac_f_ex = ac->ac_b_ex;
3702 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3703 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3704 pa->pa_len = ac->ac_b_ex.fe_len;
3705 pa->pa_free = pa->pa_len;
3706 atomic_set(&pa->pa_count, 1);
3707 spin_lock_init(&pa->pa_lock);
3708 INIT_LIST_HEAD(&pa->pa_inode_list);
3709 INIT_LIST_HEAD(&pa->pa_group_list);
3711 pa->pa_type = MB_INODE_PA;
3713 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa,
3714 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3715 trace_ext4_mb_new_inode_pa(ac, pa);
3717 ext4_mb_use_inode_pa(ac, pa);
3718 atomic_add(pa->pa_free, &sbi->s_mb_preallocated);
3720 ei = EXT4_I(ac->ac_inode);
3721 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3723 pa->pa_obj_lock = &ei->i_prealloc_lock;
3724 pa->pa_inode = ac->ac_inode;
3726 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3727 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3728 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3730 spin_lock(pa->pa_obj_lock);
3731 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3732 spin_unlock(pa->pa_obj_lock);
3738 * creates new preallocated space for locality group inodes belongs to
3740 static noinline_for_stack int
3741 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
3743 struct super_block *sb = ac->ac_sb;
3744 struct ext4_locality_group *lg;
3745 struct ext4_prealloc_space *pa;
3746 struct ext4_group_info *grp;
3748 /* preallocate only when found space is larger then requested */
3749 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3750 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3751 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3753 BUG_ON(ext4_pspace_cachep == NULL);
3754 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3758 /* preallocation can change ac_b_ex, thus we store actually
3759 * allocated blocks for history */
3760 ac->ac_f_ex = ac->ac_b_ex;
3762 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3763 pa->pa_lstart = pa->pa_pstart;
3764 pa->pa_len = ac->ac_b_ex.fe_len;
3765 pa->pa_free = pa->pa_len;
3766 atomic_set(&pa->pa_count, 1);
3767 spin_lock_init(&pa->pa_lock);
3768 INIT_LIST_HEAD(&pa->pa_inode_list);
3769 INIT_LIST_HEAD(&pa->pa_group_list);
3771 pa->pa_type = MB_GROUP_PA;
3773 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa,
3774 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3775 trace_ext4_mb_new_group_pa(ac, pa);
3777 ext4_mb_use_group_pa(ac, pa);
3778 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3780 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3784 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3785 pa->pa_inode = NULL;
3787 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3788 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3789 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3792 * We will later add the new pa to the right bucket
3793 * after updating the pa_free in ext4_mb_release_context
3798 static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3802 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3803 err = ext4_mb_new_group_pa(ac);
3805 err = ext4_mb_new_inode_pa(ac);
3810 * finds all unused blocks in on-disk bitmap, frees them in
3811 * in-core bitmap and buddy.
3812 * @pa must be unlinked from inode and group lists, so that
3813 * nobody else can find/use it.
3814 * the caller MUST hold group/inode locks.
3815 * TODO: optimize the case when there are no in-core structures yet
3817 static noinline_for_stack int
3818 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
3819 struct ext4_prealloc_space *pa)
3821 struct super_block *sb = e4b->bd_sb;
3822 struct ext4_sb_info *sbi = EXT4_SB(sb);
3827 unsigned long long grp_blk_start;
3831 BUG_ON(pa->pa_deleted == 0);
3832 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3833 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
3834 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3835 end = bit + pa->pa_len;
3838 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
3841 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
3842 mb_debug(1, " free preallocated %u/%u in group %u\n",
3843 (unsigned) ext4_group_first_block_no(sb, group) + bit,
3844 (unsigned) next - bit, (unsigned) group);
3847 trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);
3848 trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +
3849 EXT4_C2B(sbi, bit)),
3851 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3854 if (free != pa->pa_free) {
3855 ext4_msg(e4b->bd_sb, KERN_CRIT,
3856 "pa %p: logic %lu, phys. %lu, len %lu",
3857 pa, (unsigned long) pa->pa_lstart,
3858 (unsigned long) pa->pa_pstart,
3859 (unsigned long) pa->pa_len);
3860 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
3863 * pa is already deleted so we use the value obtained
3864 * from the bitmap and continue.
3867 atomic_add(free, &sbi->s_mb_discarded);
3872 static noinline_for_stack int
3873 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
3874 struct ext4_prealloc_space *pa)
3876 struct super_block *sb = e4b->bd_sb;
3880 trace_ext4_mb_release_group_pa(sb, pa);
3881 BUG_ON(pa->pa_deleted == 0);
3882 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3883 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3884 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3885 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3886 trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);
3892 * releases all preallocations in given group
3894 * first, we need to decide discard policy:
3895 * - when do we discard
3897 * - how many do we discard
3898 * 1) how many requested
3900 static noinline_for_stack int
3901 ext4_mb_discard_group_preallocations(struct super_block *sb,
3902 ext4_group_t group, int needed)
3904 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3905 struct buffer_head *bitmap_bh = NULL;
3906 struct ext4_prealloc_space *pa, *tmp;
3907 struct list_head list;
3908 struct ext4_buddy e4b;
3913 mb_debug(1, "discard preallocation for group %u\n", group);
3915 if (list_empty(&grp->bb_prealloc_list))
3918 bitmap_bh = ext4_read_block_bitmap(sb, group);
3919 if (IS_ERR(bitmap_bh)) {
3920 err = PTR_ERR(bitmap_bh);
3921 ext4_error(sb, "Error %d reading block bitmap for %u",
3926 err = ext4_mb_load_buddy(sb, group, &e4b);
3928 ext4_warning(sb, "Error %d loading buddy information for %u",
3935 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
3937 INIT_LIST_HEAD(&list);
3939 ext4_lock_group(sb, group);
3940 list_for_each_entry_safe(pa, tmp,
3941 &grp->bb_prealloc_list, pa_group_list) {
3942 spin_lock(&pa->pa_lock);
3943 if (atomic_read(&pa->pa_count)) {
3944 spin_unlock(&pa->pa_lock);
3948 if (pa->pa_deleted) {
3949 spin_unlock(&pa->pa_lock);
3953 /* seems this one can be freed ... */
3956 /* we can trust pa_free ... */
3957 free += pa->pa_free;
3959 spin_unlock(&pa->pa_lock);
3961 list_del(&pa->pa_group_list);
3962 list_add(&pa->u.pa_tmp_list, &list);
3965 /* if we still need more blocks and some PAs were used, try again */
3966 if (free < needed && busy) {
3968 ext4_unlock_group(sb, group);
3973 /* found anything to free? */
3974 if (list_empty(&list)) {
3979 /* now free all selected PAs */
3980 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3982 /* remove from object (inode or locality group) */
3983 spin_lock(pa->pa_obj_lock);
3984 list_del_rcu(&pa->pa_inode_list);
3985 spin_unlock(pa->pa_obj_lock);
3987 if (pa->pa_type == MB_GROUP_PA)
3988 ext4_mb_release_group_pa(&e4b, pa);
3990 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
3992 list_del(&pa->u.pa_tmp_list);
3993 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3997 ext4_unlock_group(sb, group);
3998 ext4_mb_unload_buddy(&e4b);
4004 * releases all non-used preallocated blocks for given inode
4006 * It's important to discard preallocations under i_data_sem
4007 * We don't want another block to be served from the prealloc
4008 * space when we are discarding the inode prealloc space.
4010 * FIXME!! Make sure it is valid at all the call sites
4012 void ext4_discard_preallocations(struct inode *inode)
4014 struct ext4_inode_info *ei = EXT4_I(inode);
4015 struct super_block *sb = inode->i_sb;
4016 struct buffer_head *bitmap_bh = NULL;
4017 struct ext4_prealloc_space *pa, *tmp;
4018 ext4_group_t group = 0;
4019 struct list_head list;
4020 struct ext4_buddy e4b;
4023 if (!S_ISREG(inode->i_mode)) {
4024 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
4028 mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino);
4029 trace_ext4_discard_preallocations(inode);
4031 INIT_LIST_HEAD(&list);
4034 /* first, collect all pa's in the inode */
4035 spin_lock(&ei->i_prealloc_lock);
4036 while (!list_empty(&ei->i_prealloc_list)) {
4037 pa = list_entry(ei->i_prealloc_list.next,
4038 struct ext4_prealloc_space, pa_inode_list);
4039 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
4040 spin_lock(&pa->pa_lock);
4041 if (atomic_read(&pa->pa_count)) {
4042 /* this shouldn't happen often - nobody should
4043 * use preallocation while we're discarding it */
4044 spin_unlock(&pa->pa_lock);
4045 spin_unlock(&ei->i_prealloc_lock);
4046 ext4_msg(sb, KERN_ERR,
4047 "uh-oh! used pa while discarding");
4049 schedule_timeout_uninterruptible(HZ);
4053 if (pa->pa_deleted == 0) {
4055 spin_unlock(&pa->pa_lock);
4056 list_del_rcu(&pa->pa_inode_list);
4057 list_add(&pa->u.pa_tmp_list, &list);
4061 /* someone is deleting pa right now */
4062 spin_unlock(&pa->pa_lock);
4063 spin_unlock(&ei->i_prealloc_lock);
4065 /* we have to wait here because pa_deleted
4066 * doesn't mean pa is already unlinked from
4067 * the list. as we might be called from
4068 * ->clear_inode() the inode will get freed
4069 * and concurrent thread which is unlinking
4070 * pa from inode's list may access already
4071 * freed memory, bad-bad-bad */
4073 /* XXX: if this happens too often, we can
4074 * add a flag to force wait only in case
4075 * of ->clear_inode(), but not in case of
4076 * regular truncate */
4077 schedule_timeout_uninterruptible(HZ);
4080 spin_unlock(&ei->i_prealloc_lock);
4082 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4083 BUG_ON(pa->pa_type != MB_INODE_PA);
4084 group = ext4_get_group_number(sb, pa->pa_pstart);
4086 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4087 GFP_NOFS|__GFP_NOFAIL);
4089 ext4_error(sb, "Error %d loading buddy information for %u",
4094 bitmap_bh = ext4_read_block_bitmap(sb, group);
4095 if (IS_ERR(bitmap_bh)) {
4096 err = PTR_ERR(bitmap_bh);
4097 ext4_error(sb, "Error %d reading block bitmap for %u",
4099 ext4_mb_unload_buddy(&e4b);
4103 ext4_lock_group(sb, group);
4104 list_del(&pa->pa_group_list);
4105 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4106 ext4_unlock_group(sb, group);
4108 ext4_mb_unload_buddy(&e4b);
4111 list_del(&pa->u.pa_tmp_list);
4112 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4116 #ifdef CONFIG_EXT4_DEBUG
4117 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4119 struct super_block *sb = ac->ac_sb;
4120 ext4_group_t ngroups, i;
4122 if (!ext4_mballoc_debug ||
4123 (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED))
4126 ext4_msg(ac->ac_sb, KERN_ERR, "Can't allocate:"
4127 " Allocation context details:");
4128 ext4_msg(ac->ac_sb, KERN_ERR, "status %d flags %d",
4129 ac->ac_status, ac->ac_flags);
4130 ext4_msg(ac->ac_sb, KERN_ERR, "orig %lu/%lu/%lu@%lu, "
4131 "goal %lu/%lu/%lu@%lu, "
4132 "best %lu/%lu/%lu@%lu cr %d",
4133 (unsigned long)ac->ac_o_ex.fe_group,
4134 (unsigned long)ac->ac_o_ex.fe_start,
4135 (unsigned long)ac->ac_o_ex.fe_len,
4136 (unsigned long)ac->ac_o_ex.fe_logical,
4137 (unsigned long)ac->ac_g_ex.fe_group,
4138 (unsigned long)ac->ac_g_ex.fe_start,
4139 (unsigned long)ac->ac_g_ex.fe_len,
4140 (unsigned long)ac->ac_g_ex.fe_logical,
4141 (unsigned long)ac->ac_b_ex.fe_group,
4142 (unsigned long)ac->ac_b_ex.fe_start,
4143 (unsigned long)ac->ac_b_ex.fe_len,
4144 (unsigned long)ac->ac_b_ex.fe_logical,
4145 (int)ac->ac_criteria);
4146 ext4_msg(ac->ac_sb, KERN_ERR, "%d found", ac->ac_found);
4147 ext4_msg(ac->ac_sb, KERN_ERR, "groups: ");
4148 ngroups = ext4_get_groups_count(sb);
4149 for (i = 0; i < ngroups; i++) {
4150 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4151 struct ext4_prealloc_space *pa;
4152 ext4_grpblk_t start;
4153 struct list_head *cur;
4154 ext4_lock_group(sb, i);
4155 list_for_each(cur, &grp->bb_prealloc_list) {
4156 pa = list_entry(cur, struct ext4_prealloc_space,
4158 spin_lock(&pa->pa_lock);
4159 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4161 spin_unlock(&pa->pa_lock);
4162 printk(KERN_ERR "PA:%u:%d:%u \n", i,
4165 ext4_unlock_group(sb, i);
4167 if (grp->bb_free == 0)
4169 printk(KERN_ERR "%u: %d/%d \n",
4170 i, grp->bb_free, grp->bb_fragments);
4172 printk(KERN_ERR "\n");
4175 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4182 * We use locality group preallocation for small size file. The size of the
4183 * file is determined by the current size or the resulting size after
4184 * allocation which ever is larger
4186 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4188 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4190 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4191 int bsbits = ac->ac_sb->s_blocksize_bits;
4194 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4197 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4200 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
4201 isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
4204 if ((size == isize) &&
4205 !ext4_fs_is_busy(sbi) &&
4206 (atomic_read(&ac->ac_inode->i_writecount) == 0)) {
4207 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
4211 if (sbi->s_mb_group_prealloc <= 0) {
4212 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4216 /* don't use group allocation for large files */
4217 size = max(size, isize);
4218 if (size > sbi->s_mb_stream_request) {
4219 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4223 BUG_ON(ac->ac_lg != NULL);
4225 * locality group prealloc space are per cpu. The reason for having
4226 * per cpu locality group is to reduce the contention between block
4227 * request from multiple CPUs.
4229 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
4231 /* we're going to use group allocation */
4232 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4234 /* serialize all allocations in the group */
4235 mutex_lock(&ac->ac_lg->lg_mutex);
4238 static noinline_for_stack int
4239 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
4240 struct ext4_allocation_request *ar)
4242 struct super_block *sb = ar->inode->i_sb;
4243 struct ext4_sb_info *sbi = EXT4_SB(sb);
4244 struct ext4_super_block *es = sbi->s_es;
4248 ext4_grpblk_t block;
4250 /* we can't allocate > group size */
4253 /* just a dirty hack to filter too big requests */
4254 if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
4255 len = EXT4_CLUSTERS_PER_GROUP(sb);
4257 /* start searching from the goal */
4259 if (goal < le32_to_cpu(es->s_first_data_block) ||
4260 goal >= ext4_blocks_count(es))
4261 goal = le32_to_cpu(es->s_first_data_block);
4262 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4264 /* set up allocation goals */
4265 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
4266 ac->ac_status = AC_STATUS_CONTINUE;
4268 ac->ac_inode = ar->inode;
4269 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
4270 ac->ac_o_ex.fe_group = group;
4271 ac->ac_o_ex.fe_start = block;
4272 ac->ac_o_ex.fe_len = len;
4273 ac->ac_g_ex = ac->ac_o_ex;
4274 ac->ac_flags = ar->flags;
4276 /* we have to define context: we'll we work with a file or
4277 * locality group. this is a policy, actually */
4278 ext4_mb_group_or_file(ac);
4280 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4281 "left: %u/%u, right %u/%u to %swritable\n",
4282 (unsigned) ar->len, (unsigned) ar->logical,
4283 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4284 (unsigned) ar->lleft, (unsigned) ar->pleft,
4285 (unsigned) ar->lright, (unsigned) ar->pright,
4286 atomic_read(&ar->inode->i_writecount) ? "" : "non-");
4291 static noinline_for_stack void
4292 ext4_mb_discard_lg_preallocations(struct super_block *sb,
4293 struct ext4_locality_group *lg,
4294 int order, int total_entries)
4296 ext4_group_t group = 0;
4297 struct ext4_buddy e4b;
4298 struct list_head discard_list;
4299 struct ext4_prealloc_space *pa, *tmp;
4301 mb_debug(1, "discard locality group preallocation\n");
4303 INIT_LIST_HEAD(&discard_list);
4305 spin_lock(&lg->lg_prealloc_lock);
4306 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
4308 spin_lock(&pa->pa_lock);
4309 if (atomic_read(&pa->pa_count)) {
4311 * This is the pa that we just used
4312 * for block allocation. So don't
4315 spin_unlock(&pa->pa_lock);
4318 if (pa->pa_deleted) {
4319 spin_unlock(&pa->pa_lock);
4322 /* only lg prealloc space */
4323 BUG_ON(pa->pa_type != MB_GROUP_PA);
4325 /* seems this one can be freed ... */
4327 spin_unlock(&pa->pa_lock);
4329 list_del_rcu(&pa->pa_inode_list);
4330 list_add(&pa->u.pa_tmp_list, &discard_list);
4333 if (total_entries <= 5) {
4335 * we want to keep only 5 entries
4336 * allowing it to grow to 8. This
4337 * mak sure we don't call discard
4338 * soon for this list.
4343 spin_unlock(&lg->lg_prealloc_lock);
4345 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
4348 group = ext4_get_group_number(sb, pa->pa_pstart);
4349 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4350 GFP_NOFS|__GFP_NOFAIL);
4352 ext4_error(sb, "Error %d loading buddy information for %u",
4356 ext4_lock_group(sb, group);
4357 list_del(&pa->pa_group_list);
4358 ext4_mb_release_group_pa(&e4b, pa);
4359 ext4_unlock_group(sb, group);
4361 ext4_mb_unload_buddy(&e4b);
4362 list_del(&pa->u.pa_tmp_list);
4363 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4368 * We have incremented pa_count. So it cannot be freed at this
4369 * point. Also we hold lg_mutex. So no parallel allocation is
4370 * possible from this lg. That means pa_free cannot be updated.
4372 * A parallel ext4_mb_discard_group_preallocations is possible.
4373 * which can cause the lg_prealloc_list to be updated.
4376 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
4378 int order, added = 0, lg_prealloc_count = 1;
4379 struct super_block *sb = ac->ac_sb;
4380 struct ext4_locality_group *lg = ac->ac_lg;
4381 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
4383 order = fls(pa->pa_free) - 1;
4384 if (order > PREALLOC_TB_SIZE - 1)
4385 /* The max size of hash table is PREALLOC_TB_SIZE */
4386 order = PREALLOC_TB_SIZE - 1;
4387 /* Add the prealloc space to lg */
4388 spin_lock(&lg->lg_prealloc_lock);
4389 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
4391 spin_lock(&tmp_pa->pa_lock);
4392 if (tmp_pa->pa_deleted) {
4393 spin_unlock(&tmp_pa->pa_lock);
4396 if (!added && pa->pa_free < tmp_pa->pa_free) {
4397 /* Add to the tail of the previous entry */
4398 list_add_tail_rcu(&pa->pa_inode_list,
4399 &tmp_pa->pa_inode_list);
4402 * we want to count the total
4403 * number of entries in the list
4406 spin_unlock(&tmp_pa->pa_lock);
4407 lg_prealloc_count++;
4410 list_add_tail_rcu(&pa->pa_inode_list,
4411 &lg->lg_prealloc_list[order]);
4412 spin_unlock(&lg->lg_prealloc_lock);
4414 /* Now trim the list to be not more than 8 elements */
4415 if (lg_prealloc_count > 8) {
4416 ext4_mb_discard_lg_preallocations(sb, lg,
4417 order, lg_prealloc_count);
4424 * release all resource we used in allocation
4426 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4428 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4429 struct ext4_prealloc_space *pa = ac->ac_pa;
4431 if (pa->pa_type == MB_GROUP_PA) {
4432 /* see comment in ext4_mb_use_group_pa() */
4433 spin_lock(&pa->pa_lock);
4434 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4435 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4436 pa->pa_free -= ac->ac_b_ex.fe_len;
4437 pa->pa_len -= ac->ac_b_ex.fe_len;
4438 spin_unlock(&pa->pa_lock);
4443 * We want to add the pa to the right bucket.
4444 * Remove it from the list and while adding
4445 * make sure the list to which we are adding
4448 if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) {
4449 spin_lock(pa->pa_obj_lock);
4450 list_del_rcu(&pa->pa_inode_list);
4451 spin_unlock(pa->pa_obj_lock);
4452 ext4_mb_add_n_trim(ac);
4454 ext4_mb_put_pa(ac, ac->ac_sb, pa);
4456 if (ac->ac_bitmap_page)
4457 put_page(ac->ac_bitmap_page);
4458 if (ac->ac_buddy_page)
4459 put_page(ac->ac_buddy_page);
4460 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4461 mutex_unlock(&ac->ac_lg->lg_mutex);
4462 ext4_mb_collect_stats(ac);
4466 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4468 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4472 trace_ext4_mb_discard_preallocations(sb, needed);
4473 for (i = 0; i < ngroups && needed > 0; i++) {
4474 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4483 * Main entry point into mballoc to allocate blocks
4484 * it tries to use preallocation first, then falls back
4485 * to usual allocation
4487 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4488 struct ext4_allocation_request *ar, int *errp)
4491 struct ext4_allocation_context *ac = NULL;
4492 struct ext4_sb_info *sbi;
4493 struct super_block *sb;
4494 ext4_fsblk_t block = 0;
4495 unsigned int inquota = 0;
4496 unsigned int reserv_clstrs = 0;
4499 sb = ar->inode->i_sb;
4502 trace_ext4_request_blocks(ar);
4504 /* Allow to use superuser reservation for quota file */
4505 if (ext4_is_quota_file(ar->inode))
4506 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
4508 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
4509 /* Without delayed allocation we need to verify
4510 * there is enough free blocks to do block allocation
4511 * and verify allocation doesn't exceed the quota limits.
4514 ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
4516 /* let others to free the space */
4518 ar->len = ar->len >> 1;
4524 reserv_clstrs = ar->len;
4525 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
4526 dquot_alloc_block_nofail(ar->inode,
4527 EXT4_C2B(sbi, ar->len));
4530 dquot_alloc_block(ar->inode,
4531 EXT4_C2B(sbi, ar->len))) {
4533 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4544 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
4551 *errp = ext4_mb_initialize_context(ac, ar);
4557 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4558 if (!ext4_mb_use_preallocated(ac)) {
4559 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4560 ext4_mb_normalize_request(ac, ar);
4562 /* allocate space in core */
4563 *errp = ext4_mb_regular_allocator(ac);
4565 goto discard_and_exit;
4567 /* as we've just preallocated more space than
4568 * user requested originally, we store allocated
4569 * space in a special descriptor */
4570 if (ac->ac_status == AC_STATUS_FOUND &&
4571 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4572 *errp = ext4_mb_new_preallocation(ac);
4575 ext4_discard_allocated_blocks(ac);
4579 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
4580 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
4582 ext4_discard_allocated_blocks(ac);
4585 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4586 ar->len = ac->ac_b_ex.fe_len;
4589 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
4597 ac->ac_b_ex.fe_len = 0;
4599 ext4_mb_show_ac(ac);
4601 ext4_mb_release_context(ac);
4604 kmem_cache_free(ext4_ac_cachep, ac);
4605 if (inquota && ar->len < inquota)
4606 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
4608 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
4609 /* release all the reserved blocks if non delalloc */
4610 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
4614 trace_ext4_allocate_blocks(ar, (unsigned long long)block);
4620 * We can merge two free data extents only if the physical blocks
4621 * are contiguous, AND the extents were freed by the same transaction,
4622 * AND the blocks are associated with the same group.
4624 static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
4625 struct ext4_free_data *entry,
4626 struct ext4_free_data *new_entry,
4627 struct rb_root *entry_rb_root)
4629 if ((entry->efd_tid != new_entry->efd_tid) ||
4630 (entry->efd_group != new_entry->efd_group))
4632 if (entry->efd_start_cluster + entry->efd_count ==
4633 new_entry->efd_start_cluster) {
4634 new_entry->efd_start_cluster = entry->efd_start_cluster;
4635 new_entry->efd_count += entry->efd_count;
4636 } else if (new_entry->efd_start_cluster + new_entry->efd_count ==
4637 entry->efd_start_cluster) {
4638 new_entry->efd_count += entry->efd_count;
4641 spin_lock(&sbi->s_md_lock);
4642 list_del(&entry->efd_list);
4643 spin_unlock(&sbi->s_md_lock);
4644 rb_erase(&entry->efd_node, entry_rb_root);
4645 kmem_cache_free(ext4_free_data_cachep, entry);
4648 static noinline_for_stack int
4649 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
4650 struct ext4_free_data *new_entry)
4652 ext4_group_t group = e4b->bd_group;
4653 ext4_grpblk_t cluster;
4654 ext4_grpblk_t clusters = new_entry->efd_count;
4655 struct ext4_free_data *entry;
4656 struct ext4_group_info *db = e4b->bd_info;
4657 struct super_block *sb = e4b->bd_sb;
4658 struct ext4_sb_info *sbi = EXT4_SB(sb);
4659 struct rb_node **n = &db->bb_free_root.rb_node, *node;
4660 struct rb_node *parent = NULL, *new_node;
4662 BUG_ON(!ext4_handle_valid(handle));
4663 BUG_ON(e4b->bd_bitmap_page == NULL);
4664 BUG_ON(e4b->bd_buddy_page == NULL);
4666 new_node = &new_entry->efd_node;
4667 cluster = new_entry->efd_start_cluster;
4670 /* first free block exent. We need to
4671 protect buddy cache from being freed,
4672 * otherwise we'll refresh it from
4673 * on-disk bitmap and lose not-yet-available
4675 get_page(e4b->bd_buddy_page);
4676 get_page(e4b->bd_bitmap_page);
4680 entry = rb_entry(parent, struct ext4_free_data, efd_node);
4681 if (cluster < entry->efd_start_cluster)
4683 else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
4684 n = &(*n)->rb_right;
4686 ext4_grp_locked_error(sb, group, 0,
4687 ext4_group_first_block_no(sb, group) +
4688 EXT4_C2B(sbi, cluster),
4689 "Block already on to-be-freed list");
4694 rb_link_node(new_node, parent, n);
4695 rb_insert_color(new_node, &db->bb_free_root);
4697 /* Now try to see the extent can be merged to left and right */
4698 node = rb_prev(new_node);
4700 entry = rb_entry(node, struct ext4_free_data, efd_node);
4701 ext4_try_merge_freed_extent(sbi, entry, new_entry,
4702 &(db->bb_free_root));
4705 node = rb_next(new_node);
4707 entry = rb_entry(node, struct ext4_free_data, efd_node);
4708 ext4_try_merge_freed_extent(sbi, entry, new_entry,
4709 &(db->bb_free_root));
4712 spin_lock(&sbi->s_md_lock);
4713 list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list);
4714 sbi->s_mb_free_pending += clusters;
4715 spin_unlock(&sbi->s_md_lock);
4720 * ext4_free_blocks() -- Free given blocks and update quota
4721 * @handle: handle for this transaction
4723 * @block: start physical block to free
4724 * @count: number of blocks to count
4725 * @flags: flags used by ext4_free_blocks
4727 void ext4_free_blocks(handle_t *handle, struct inode *inode,
4728 struct buffer_head *bh, ext4_fsblk_t block,
4729 unsigned long count, int flags)
4731 struct buffer_head *bitmap_bh = NULL;
4732 struct super_block *sb = inode->i_sb;
4733 struct ext4_group_desc *gdp;
4734 unsigned int overflow;
4736 struct buffer_head *gd_bh;
4737 ext4_group_t block_group;
4738 struct ext4_sb_info *sbi;
4739 struct ext4_buddy e4b;
4740 unsigned int count_clusters;
4747 BUG_ON(block != bh->b_blocknr);
4749 block = bh->b_blocknr;
4753 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
4754 !ext4_data_block_valid(sbi, block, count)) {
4755 ext4_error(sb, "Freeing blocks not in datazone - "
4756 "block = %llu, count = %lu", block, count);
4760 ext4_debug("freeing block %llu\n", block);
4761 trace_ext4_free_blocks(inode, block, count, flags);
4763 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
4766 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
4771 * If the extent to be freed does not begin on a cluster
4772 * boundary, we need to deal with partial clusters at the
4773 * beginning and end of the extent. Normally we will free
4774 * blocks at the beginning or the end unless we are explicitly
4775 * requested to avoid doing so.
4777 overflow = EXT4_PBLK_COFF(sbi, block);
4779 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
4780 overflow = sbi->s_cluster_ratio - overflow;
4782 if (count > overflow)
4791 overflow = EXT4_LBLK_COFF(sbi, count);
4793 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
4794 if (count > overflow)
4799 count += sbi->s_cluster_ratio - overflow;
4802 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
4804 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
4806 for (i = 0; i < count; i++) {
4809 bh = sb_find_get_block(inode->i_sb, block + i);
4810 ext4_forget(handle, is_metadata, inode, bh, block + i);
4816 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4818 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
4819 ext4_get_group_info(sb, block_group))))
4823 * Check to see if we are freeing blocks across a group
4826 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4827 overflow = EXT4_C2B(sbi, bit) + count -
4828 EXT4_BLOCKS_PER_GROUP(sb);
4831 count_clusters = EXT4_NUM_B2C(sbi, count);
4832 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
4833 if (IS_ERR(bitmap_bh)) {
4834 err = PTR_ERR(bitmap_bh);
4838 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
4844 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4845 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4846 in_range(block, ext4_inode_table(sb, gdp),
4847 EXT4_SB(sb)->s_itb_per_group) ||
4848 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4849 EXT4_SB(sb)->s_itb_per_group)) {
4851 ext4_error(sb, "Freeing blocks in system zone - "
4852 "Block = %llu, count = %lu", block, count);
4853 /* err = 0. ext4_std_error should be a no op */
4857 BUFFER_TRACE(bitmap_bh, "getting write access");
4858 err = ext4_journal_get_write_access(handle, bitmap_bh);
4863 * We are about to modify some metadata. Call the journal APIs
4864 * to unshare ->b_data if a currently-committing transaction is
4867 BUFFER_TRACE(gd_bh, "get_write_access");
4868 err = ext4_journal_get_write_access(handle, gd_bh);
4871 #ifdef AGGRESSIVE_CHECK
4874 for (i = 0; i < count_clusters; i++)
4875 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4878 trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters);
4880 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
4881 err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b,
4882 GFP_NOFS|__GFP_NOFAIL);
4887 * We need to make sure we don't reuse the freed block until after the
4888 * transaction is committed. We make an exception if the inode is to be
4889 * written in writeback mode since writeback mode has weak data
4890 * consistency guarantees.
4892 if (ext4_handle_valid(handle) &&
4893 ((flags & EXT4_FREE_BLOCKS_METADATA) ||
4894 !ext4_should_writeback_data(inode))) {
4895 struct ext4_free_data *new_entry;
4897 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
4900 new_entry = kmem_cache_alloc(ext4_free_data_cachep,
4901 GFP_NOFS|__GFP_NOFAIL);
4902 new_entry->efd_start_cluster = bit;
4903 new_entry->efd_group = block_group;
4904 new_entry->efd_count = count_clusters;
4905 new_entry->efd_tid = handle->h_transaction->t_tid;
4907 ext4_lock_group(sb, block_group);
4908 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
4909 ext4_mb_free_metadata(handle, &e4b, new_entry);
4911 /* need to update group_info->bb_free and bitmap
4912 * with group lock held. generate_buddy look at
4913 * them with group lock_held
4915 if (test_opt(sb, DISCARD)) {
4916 err = ext4_issue_discard(sb, block_group, bit, count,
4918 if (err && err != -EOPNOTSUPP)
4919 ext4_msg(sb, KERN_WARNING, "discard request in"
4920 " group:%d block:%d count:%lu failed"
4921 " with %d", block_group, bit, count,
4924 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
4926 ext4_lock_group(sb, block_group);
4927 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
4928 mb_free_blocks(inode, &e4b, bit, count_clusters);
4931 ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
4932 ext4_free_group_clusters_set(sb, gdp, ret);
4933 ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
4934 ext4_group_desc_csum_set(sb, block_group, gdp);
4935 ext4_unlock_group(sb, block_group);
4937 if (sbi->s_log_groups_per_flex) {
4938 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
4939 atomic64_add(count_clusters,
4940 &sbi->s_flex_groups[flex_group].free_clusters);
4943 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
4944 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
4945 percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
4947 ext4_mb_unload_buddy(&e4b);
4949 /* We dirtied the bitmap block */
4950 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4951 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
4953 /* And the group descriptor block */
4954 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4955 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
4959 if (overflow && !err) {
4967 ext4_std_error(sb, err);
4972 * ext4_group_add_blocks() -- Add given blocks to an existing group
4973 * @handle: handle to this transaction
4975 * @block: start physical block to add to the block group
4976 * @count: number of blocks to free
4978 * This marks the blocks as free in the bitmap and buddy.
4980 int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
4981 ext4_fsblk_t block, unsigned long count)
4983 struct buffer_head *bitmap_bh = NULL;
4984 struct buffer_head *gd_bh;
4985 ext4_group_t block_group;
4988 struct ext4_group_desc *desc;
4989 struct ext4_sb_info *sbi = EXT4_SB(sb);
4990 struct ext4_buddy e4b;
4991 int err = 0, ret, blk_free_count;
4992 ext4_grpblk_t blocks_freed;
4994 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
4999 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
5001 * Check to see if we are freeing blocks across a group
5004 if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
5005 ext4_warning(sb, "too much blocks added to group %u",
5011 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
5012 if (IS_ERR(bitmap_bh)) {
5013 err = PTR_ERR(bitmap_bh);
5018 desc = ext4_get_group_desc(sb, block_group, &gd_bh);
5024 if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
5025 in_range(ext4_inode_bitmap(sb, desc), block, count) ||
5026 in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
5027 in_range(block + count - 1, ext4_inode_table(sb, desc),
5028 sbi->s_itb_per_group)) {
5029 ext4_error(sb, "Adding blocks in system zones - "
5030 "Block = %llu, count = %lu",
5036 BUFFER_TRACE(bitmap_bh, "getting write access");
5037 err = ext4_journal_get_write_access(handle, bitmap_bh);
5042 * We are about to modify some metadata. Call the journal APIs
5043 * to unshare ->b_data if a currently-committing transaction is
5046 BUFFER_TRACE(gd_bh, "get_write_access");
5047 err = ext4_journal_get_write_access(handle, gd_bh);
5051 for (i = 0, blocks_freed = 0; i < count; i++) {
5052 BUFFER_TRACE(bitmap_bh, "clear bit");
5053 if (!mb_test_bit(bit + i, bitmap_bh->b_data)) {
5054 ext4_error(sb, "bit already cleared for block %llu",
5055 (ext4_fsblk_t)(block + i));
5056 BUFFER_TRACE(bitmap_bh, "bit already cleared");
5062 err = ext4_mb_load_buddy(sb, block_group, &e4b);
5067 * need to update group_info->bb_free and bitmap
5068 * with group lock held. generate_buddy look at
5069 * them with group lock_held
5071 ext4_lock_group(sb, block_group);
5072 mb_clear_bits(bitmap_bh->b_data, bit, count);
5073 mb_free_blocks(NULL, &e4b, bit, count);
5074 blk_free_count = blocks_freed + ext4_free_group_clusters(sb, desc);
5075 ext4_free_group_clusters_set(sb, desc, blk_free_count);
5076 ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
5077 ext4_group_desc_csum_set(sb, block_group, desc);
5078 ext4_unlock_group(sb, block_group);
5079 percpu_counter_add(&sbi->s_freeclusters_counter,
5080 EXT4_NUM_B2C(sbi, blocks_freed));
5082 if (sbi->s_log_groups_per_flex) {
5083 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
5084 atomic64_add(EXT4_NUM_B2C(sbi, blocks_freed),
5085 &sbi->s_flex_groups[flex_group].free_clusters);
5088 ext4_mb_unload_buddy(&e4b);
5090 /* We dirtied the bitmap block */
5091 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
5092 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
5094 /* And the group descriptor block */
5095 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
5096 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
5102 ext4_std_error(sb, err);
5107 * ext4_trim_extent -- function to TRIM one single free extent in the group
5108 * @sb: super block for the file system
5109 * @start: starting block of the free extent in the alloc. group
5110 * @count: number of blocks to TRIM
5111 * @group: alloc. group we are working with
5112 * @e4b: ext4 buddy for the group
5114 * Trim "count" blocks starting at "start" in the "group". To assure that no
5115 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5116 * be called with under the group lock.
5118 static int ext4_trim_extent(struct super_block *sb, int start, int count,
5119 ext4_group_t group, struct ext4_buddy *e4b)
5123 struct ext4_free_extent ex;
5126 trace_ext4_trim_extent(sb, group, start, count);
5128 assert_spin_locked(ext4_group_lock_ptr(sb, group));
5130 ex.fe_start = start;
5131 ex.fe_group = group;
5135 * Mark blocks used, so no one can reuse them while
5138 mb_mark_used(e4b, &ex);
5139 ext4_unlock_group(sb, group);
5140 ret = ext4_issue_discard(sb, group, start, count, NULL);
5141 ext4_lock_group(sb, group);
5142 mb_free_blocks(NULL, e4b, start, ex.fe_len);
5147 * ext4_trim_all_free -- function to trim all free space in alloc. group
5148 * @sb: super block for file system
5149 * @group: group to be trimmed
5150 * @start: first group block to examine
5151 * @max: last group block to examine
5152 * @minblocks: minimum extent block count
5154 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5155 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5159 * ext4_trim_all_free walks through group's block bitmap searching for free
5160 * extents. When the free extent is found, mark it as used in group buddy
5161 * bitmap. Then issue a TRIM command on this extent and free the extent in
5162 * the group buddy bitmap. This is done until whole group is scanned.
5164 static ext4_grpblk_t
5165 ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
5166 ext4_grpblk_t start, ext4_grpblk_t max,
5167 ext4_grpblk_t minblocks)
5170 ext4_grpblk_t next, count = 0, free_count = 0;
5171 struct ext4_buddy e4b;
5174 trace_ext4_trim_all_free(sb, group, start, max);
5176 ret = ext4_mb_load_buddy(sb, group, &e4b);
5178 ext4_warning(sb, "Error %d loading buddy information for %u",
5182 bitmap = e4b.bd_bitmap;
5184 ext4_lock_group(sb, group);
5185 if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
5186 minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
5189 start = (e4b.bd_info->bb_first_free > start) ?
5190 e4b.bd_info->bb_first_free : start;
5192 while (start <= max) {
5193 start = mb_find_next_zero_bit(bitmap, max + 1, start);
5196 next = mb_find_next_bit(bitmap, max + 1, start);
5198 if ((next - start) >= minblocks) {
5199 ret = ext4_trim_extent(sb, start,
5200 next - start, group, &e4b);
5201 if (ret && ret != -EOPNOTSUPP)
5204 count += next - start;
5206 free_count += next - start;
5209 if (fatal_signal_pending(current)) {
5210 count = -ERESTARTSYS;
5214 if (need_resched()) {
5215 ext4_unlock_group(sb, group);
5217 ext4_lock_group(sb, group);
5220 if ((e4b.bd_info->bb_free - free_count) < minblocks)
5226 EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
5229 ext4_unlock_group(sb, group);
5230 ext4_mb_unload_buddy(&e4b);
5232 ext4_debug("trimmed %d blocks in the group %d\n",
5239 * ext4_trim_fs() -- trim ioctl handle function
5240 * @sb: superblock for filesystem
5241 * @range: fstrim_range structure
5243 * start: First Byte to trim
5244 * len: number of Bytes to trim from start
5245 * minlen: minimum extent length in Bytes
5246 * ext4_trim_fs goes through all allocation groups containing Bytes from
5247 * start to start+len. For each such a group ext4_trim_all_free function
5248 * is invoked to trim all free space.
5250 int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
5252 struct ext4_group_info *grp;
5253 ext4_group_t group, first_group, last_group;
5254 ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
5255 uint64_t start, end, minlen, trimmed = 0;
5256 ext4_fsblk_t first_data_blk =
5257 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
5258 ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es);
5261 start = range->start >> sb->s_blocksize_bits;
5262 end = start + (range->len >> sb->s_blocksize_bits) - 1;
5263 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
5264 range->minlen >> sb->s_blocksize_bits);
5266 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
5267 start >= max_blks ||
5268 range->len < sb->s_blocksize)
5270 if (end >= max_blks)
5272 if (end <= first_data_blk)
5274 if (start < first_data_blk)
5275 start = first_data_blk;
5277 /* Determine first and last group to examine based on start and end */
5278 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,
5279 &first_group, &first_cluster);
5280 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end,
5281 &last_group, &last_cluster);
5283 /* end now represents the last cluster to discard in this group */
5284 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5286 for (group = first_group; group <= last_group; group++) {
5287 grp = ext4_get_group_info(sb, group);
5288 /* We only do this if the grp has never been initialized */
5289 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
5290 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
5296 * For all the groups except the last one, last cluster will
5297 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5298 * change it for the last group, note that last_cluster is
5299 * already computed earlier by ext4_get_group_no_and_offset()
5301 if (group == last_group)
5304 if (grp->bb_free >= minlen) {
5305 cnt = ext4_trim_all_free(sb, group, first_cluster,
5315 * For every group except the first one, we are sure
5316 * that the first cluster to discard will be cluster #0.
5322 atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
5325 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
5329 /* Iterate all the free extents in the group. */
5331 ext4_mballoc_query_range(
5332 struct super_block *sb,
5334 ext4_grpblk_t start,
5336 ext4_mballoc_query_range_fn formatter,
5341 struct ext4_buddy e4b;
5344 error = ext4_mb_load_buddy(sb, group, &e4b);
5347 bitmap = e4b.bd_bitmap;
5349 ext4_lock_group(sb, group);
5351 start = (e4b.bd_info->bb_first_free > start) ?
5352 e4b.bd_info->bb_first_free : start;
5353 if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
5354 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5356 while (start <= end) {
5357 start = mb_find_next_zero_bit(bitmap, end + 1, start);
5360 next = mb_find_next_bit(bitmap, end + 1, start);
5362 ext4_unlock_group(sb, group);
5363 error = formatter(sb, group, start, next - start, priv);
5366 ext4_lock_group(sb, group);
5371 ext4_unlock_group(sb, group);
5373 ext4_mb_unload_buddy(&e4b);