1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
4 * Written by Alex Tomas <alex@clusterfs.com>
9 * mballoc.c contains the multiblocks allocation routines
12 #include "ext4_jbd2.h"
14 #include <linux/log2.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/nospec.h>
18 #include <linux/backing-dev.h>
19 #include <linux/freezer.h>
20 #include <trace/events/ext4.h>
21 #include <kunit/static_stub.h>
25 * - test ext4_ext_search_left() and ext4_ext_search_right()
26 * - search for metadata in few groups
29 * - normalization should take into account whether file is still open
30 * - discard preallocations if no free space left (policy?)
31 * - don't normalize tails
33 * - reservation for superuser
36 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
37 * - track min/max extents in each group for better group selection
38 * - mb_mark_used() may allocate chunk right after splitting buddy
39 * - tree of groups sorted by number of free blocks
44 * The allocation request involve request for multiple number of blocks
45 * near to the goal(block) value specified.
47 * During initialization phase of the allocator we decide to use the
48 * group preallocation or inode preallocation depending on the size of
49 * the file. The size of the file could be the resulting file size we
50 * would have after allocation, or the current file size, which ever
51 * is larger. If the size is less than sbi->s_mb_stream_request we
52 * select to use the group preallocation. The default value of
53 * s_mb_stream_request is 16 blocks. This can also be tuned via
54 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
55 * terms of number of blocks.
57 * The main motivation for having small file use group preallocation is to
58 * ensure that we have small files closer together on the disk.
60 * First stage the allocator looks at the inode prealloc list,
61 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
62 * spaces for this particular inode. The inode prealloc space is
65 * pa_lstart -> the logical start block for this prealloc space
66 * pa_pstart -> the physical start block for this prealloc space
67 * pa_len -> length for this prealloc space (in clusters)
68 * pa_free -> free space available in this prealloc space (in clusters)
70 * The inode preallocation space is used looking at the _logical_ start
71 * block. If only the logical file block falls within the range of prealloc
72 * space we will consume the particular prealloc space. This makes sure that
73 * we have contiguous physical blocks representing the file blocks
75 * The important thing to be noted in case of inode prealloc space is that
76 * we don't modify the values associated to inode prealloc space except
79 * If we are not able to find blocks in the inode prealloc space and if we
80 * have the group allocation flag set then we look at the locality group
81 * prealloc space. These are per CPU prealloc list represented as
83 * ext4_sb_info.s_locality_groups[smp_processor_id()]
85 * The reason for having a per cpu locality group is to reduce the contention
86 * between CPUs. It is possible to get scheduled at this point.
88 * The locality group prealloc space is used looking at whether we have
89 * enough free space (pa_free) within the prealloc space.
91 * If we can't allocate blocks via inode prealloc or/and locality group
92 * prealloc then we look at the buddy cache. The buddy cache is represented
93 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
94 * mapped to the buddy and bitmap information regarding different
95 * groups. The buddy information is attached to buddy cache inode so that
96 * we can access them through the page cache. The information regarding
97 * each group is loaded via ext4_mb_load_buddy. The information involve
98 * block bitmap and buddy information. The information are stored in the
102 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
105 * one block each for bitmap and buddy information. So for each group we
106 * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
107 * blocksize) blocks. So it can have information regarding groups_per_page
108 * which is blocks_per_page/2
110 * The buddy cache inode is not stored on disk. The inode is thrown
111 * away when the filesystem is unmounted.
113 * We look for count number of blocks in the buddy cache. If we were able
114 * to locate that many free blocks we return with additional information
115 * regarding rest of the contiguous physical block available
117 * Before allocating blocks via buddy cache we normalize the request
118 * blocks. This ensure we ask for more blocks that we needed. The extra
119 * blocks that we get after allocation is added to the respective prealloc
120 * list. In case of inode preallocation we follow a list of heuristics
121 * based on file size. This can be found in ext4_mb_normalize_request. If
122 * we are doing a group prealloc we try to normalize the request to
123 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
124 * dependent on the cluster size; for non-bigalloc file systems, it is
125 * 512 blocks. This can be tuned via
126 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
127 * terms of number of blocks. If we have mounted the file system with -O
128 * stripe=<value> option the group prealloc request is normalized to the
129 * smallest multiple of the stripe value (sbi->s_stripe) which is
130 * greater than the default mb_group_prealloc.
132 * If "mb_optimize_scan" mount option is set, we maintain in memory group info
133 * structures in two data structures:
135 * 1) Array of largest free order lists (sbi->s_mb_largest_free_orders)
137 * Locking: sbi->s_mb_largest_free_orders_locks(array of rw locks)
139 * This is an array of lists where the index in the array represents the
140 * largest free order in the buddy bitmap of the participating group infos of
141 * that list. So, there are exactly MB_NUM_ORDERS(sb) (which means total
142 * number of buddy bitmap orders possible) number of lists. Group-infos are
143 * placed in appropriate lists.
145 * 2) Average fragment size lists (sbi->s_mb_avg_fragment_size)
147 * Locking: sbi->s_mb_avg_fragment_size_locks(array of rw locks)
149 * This is an array of lists where in the i-th list there are groups with
150 * average fragment size >= 2^i and < 2^(i+1). The average fragment size
151 * is computed as ext4_group_info->bb_free / ext4_group_info->bb_fragments.
152 * Note that we don't bother with a special list for completely empty groups
153 * so we only have MB_NUM_ORDERS(sb) lists.
155 * When "mb_optimize_scan" mount option is set, mballoc consults the above data
156 * structures to decide the order in which groups are to be traversed for
157 * fulfilling an allocation request.
159 * At CR_POWER2_ALIGNED , we look for groups which have the largest_free_order
160 * >= the order of the request. We directly look at the largest free order list
161 * in the data structure (1) above where largest_free_order = order of the
162 * request. If that list is empty, we look at remaining list in the increasing
163 * order of largest_free_order. This allows us to perform CR_POWER2_ALIGNED
164 * lookup in O(1) time.
166 * At CR_GOAL_LEN_FAST, we only consider groups where
167 * average fragment size > request size. So, we lookup a group which has average
168 * fragment size just above or equal to request size using our average fragment
169 * size group lists (data structure 2) in O(1) time.
171 * At CR_BEST_AVAIL_LEN, we aim to optimize allocations which can't be satisfied
172 * in CR_GOAL_LEN_FAST. The fact that we couldn't find a group in
173 * CR_GOAL_LEN_FAST suggests that there is no BG that has avg
174 * fragment size > goal length. So before falling to the slower
175 * CR_GOAL_LEN_SLOW, in CR_BEST_AVAIL_LEN we proactively trim goal length and
176 * then use the same fragment lists as CR_GOAL_LEN_FAST to find a BG with a big
177 * enough average fragment size. This increases the chances of finding a
178 * suitable block group in O(1) time and results in faster allocation at the
179 * cost of reduced size of allocation.
181 * If "mb_optimize_scan" mount option is not set, mballoc traverses groups in
182 * linear order which requires O(N) search time for each CR_POWER2_ALIGNED and
183 * CR_GOAL_LEN_FAST phase.
185 * The regular allocator (using the buddy cache) supports a few tunables.
187 * /sys/fs/ext4/<partition>/mb_min_to_scan
188 * /sys/fs/ext4/<partition>/mb_max_to_scan
189 * /sys/fs/ext4/<partition>/mb_order2_req
190 * /sys/fs/ext4/<partition>/mb_linear_limit
192 * The regular allocator uses buddy scan only if the request len is power of
193 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
194 * value of s_mb_order2_reqs can be tuned via
195 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
196 * stripe size (sbi->s_stripe), we try to search for contiguous block in
197 * stripe size. This should result in better allocation on RAID setups. If
198 * not, we search in the specific group using bitmap for best extents. The
199 * tunable min_to_scan and max_to_scan control the behaviour here.
200 * min_to_scan indicate how long the mballoc __must__ look for a best
201 * extent and max_to_scan indicates how long the mballoc __can__ look for a
202 * best extent in the found extents. Searching for the blocks starts with
203 * the group specified as the goal value in allocation context via
204 * ac_g_ex. Each group is first checked based on the criteria whether it
205 * can be used for allocation. ext4_mb_good_group explains how the groups are
208 * When "mb_optimize_scan" is turned on, as mentioned above, the groups may not
209 * get traversed linearly. That may result in subsequent allocations being not
210 * close to each other. And so, the underlying device may get filled up in a
211 * non-linear fashion. While that may not matter on non-rotational devices, for
212 * rotational devices that may result in higher seek times. "mb_linear_limit"
213 * tells mballoc how many groups mballoc should search linearly before
214 * performing consulting above data structures for more efficient lookups. For
215 * non rotational devices, this value defaults to 0 and for rotational devices
216 * this is set to MB_DEFAULT_LINEAR_LIMIT.
218 * Both the prealloc space are getting populated as above. So for the first
219 * request we will hit the buddy cache which will result in this prealloc
220 * space getting filled. The prealloc space is then later used for the
221 * subsequent request.
225 * mballoc operates on the following data:
227 * - in-core buddy (actually includes buddy and bitmap)
228 * - preallocation descriptors (PAs)
230 * there are two types of preallocations:
232 * assiged to specific inode and can be used for this inode only.
233 * it describes part of inode's space preallocated to specific
234 * physical blocks. any block from that preallocated can be used
235 * independent. the descriptor just tracks number of blocks left
236 * unused. so, before taking some block from descriptor, one must
237 * make sure corresponded logical block isn't allocated yet. this
238 * also means that freeing any block within descriptor's range
239 * must discard all preallocated blocks.
241 * assigned to specific locality group which does not translate to
242 * permanent set of inodes: inode can join and leave group. space
243 * from this type of preallocation can be used for any inode. thus
244 * it's consumed from the beginning to the end.
246 * relation between them can be expressed as:
247 * in-core buddy = on-disk bitmap + preallocation descriptors
249 * this mean blocks mballoc considers used are:
250 * - allocated blocks (persistent)
251 * - preallocated blocks (non-persistent)
253 * consistency in mballoc world means that at any time a block is either
254 * free or used in ALL structures. notice: "any time" should not be read
255 * literally -- time is discrete and delimited by locks.
257 * to keep it simple, we don't use block numbers, instead we count number of
258 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
260 * all operations can be expressed as:
261 * - init buddy: buddy = on-disk + PAs
262 * - new PA: buddy += N; PA = N
263 * - use inode PA: on-disk += N; PA -= N
264 * - discard inode PA buddy -= on-disk - PA; PA = 0
265 * - use locality group PA on-disk += N; PA -= N
266 * - discard locality group PA buddy -= PA; PA = 0
267 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
268 * is used in real operation because we can't know actual used
269 * bits from PA, only from on-disk bitmap
271 * if we follow this strict logic, then all operations above should be atomic.
272 * given some of them can block, we'd have to use something like semaphores
273 * killing performance on high-end SMP hardware. let's try to relax it using
274 * the following knowledge:
275 * 1) if buddy is referenced, it's already initialized
276 * 2) while block is used in buddy and the buddy is referenced,
277 * nobody can re-allocate that block
278 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
279 * bit set and PA claims same block, it's OK. IOW, one can set bit in
280 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
283 * so, now we're building a concurrency table:
286 * blocks for PA are allocated in the buddy, buddy must be referenced
287 * until PA is linked to allocation group to avoid concurrent buddy init
289 * we need to make sure that either on-disk bitmap or PA has uptodate data
290 * given (3) we care that PA-=N operation doesn't interfere with init
292 * the simplest way would be to have buddy initialized by the discard
293 * - use locality group PA
294 * again PA-=N must be serialized with init
295 * - discard locality group PA
296 * the simplest way would be to have buddy initialized by the discard
299 * i_data_sem serializes them
301 * discard process must wait until PA isn't used by another process
302 * - use locality group PA
303 * some mutex should serialize them
304 * - discard locality group PA
305 * discard process must wait until PA isn't used by another process
308 * i_data_sem or another mutex should serializes them
310 * discard process must wait until PA isn't used by another process
311 * - use locality group PA
312 * nothing wrong here -- they're different PAs covering different blocks
313 * - discard locality group PA
314 * discard process must wait until PA isn't used by another process
316 * now we're ready to make few consequences:
317 * - PA is referenced and while it is no discard is possible
318 * - PA is referenced until block isn't marked in on-disk bitmap
319 * - PA changes only after on-disk bitmap
320 * - discard must not compete with init. either init is done before
321 * any discard or they're serialized somehow
322 * - buddy init as sum of on-disk bitmap and PAs is done atomically
324 * a special case when we've used PA to emptiness. no need to modify buddy
325 * in this case, but we should care about concurrent init
330 * Logic in few words:
335 * mark bits in on-disk bitmap
338 * - use preallocation:
339 * find proper PA (per-inode or group)
341 * mark bits in on-disk bitmap
347 * mark bits in on-disk bitmap
350 * - discard preallocations in group:
352 * move them onto local list
353 * load on-disk bitmap
355 * remove PA from object (inode or locality group)
356 * mark free blocks in-core
358 * - discard inode's preallocations:
365 * - bitlock on a group (group)
366 * - object (inode/locality) (object)
368 * - cr_power2_aligned lists lock (cr_power2_aligned)
369 * - cr_goal_len_fast lists lock (cr_goal_len_fast)
379 * - release consumed pa:
384 * - generate in-core bitmap:
388 * - discard all for given object (inode, locality group):
393 * - discard all for given group:
399 * - allocation path (ext4_mb_regular_allocator)
401 * cr_power2_aligned/cr_goal_len_fast
403 static struct kmem_cache *ext4_pspace_cachep;
404 static struct kmem_cache *ext4_ac_cachep;
405 static struct kmem_cache *ext4_free_data_cachep;
407 /* We create slab caches for groupinfo data structures based on the
408 * superblock block size. There will be one per mounted filesystem for
409 * each unique s_blocksize_bits */
410 #define NR_GRPINFO_CACHES 8
411 static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
413 static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
414 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
415 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
416 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
419 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
421 static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
423 static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
424 ext4_group_t group, enum criteria cr);
426 static int ext4_try_to_trim_range(struct super_block *sb,
427 struct ext4_buddy *e4b, ext4_grpblk_t start,
428 ext4_grpblk_t max, ext4_grpblk_t minblocks);
431 * The algorithm using this percpu seq counter goes below:
432 * 1. We sample the percpu discard_pa_seq counter before trying for block
433 * allocation in ext4_mb_new_blocks().
434 * 2. We increment this percpu discard_pa_seq counter when we either allocate
435 * or free these blocks i.e. while marking those blocks as used/free in
436 * mb_mark_used()/mb_free_blocks().
437 * 3. We also increment this percpu seq counter when we successfully identify
438 * that the bb_prealloc_list is not empty and hence proceed for discarding
439 * of those PAs inside ext4_mb_discard_group_preallocations().
441 * Now to make sure that the regular fast path of block allocation is not
442 * affected, as a small optimization we only sample the percpu seq counter
443 * on that cpu. Only when the block allocation fails and when freed blocks
444 * found were 0, that is when we sample percpu seq counter for all cpus using
445 * below function ext4_get_discard_pa_seq_sum(). This happens after making
446 * sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty.
448 static DEFINE_PER_CPU(u64, discard_pa_seq);
449 static inline u64 ext4_get_discard_pa_seq_sum(void)
454 for_each_possible_cpu(__cpu)
455 __seq += per_cpu(discard_pa_seq, __cpu);
459 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
461 #if BITS_PER_LONG == 64
462 *bit += ((unsigned long) addr & 7UL) << 3;
463 addr = (void *) ((unsigned long) addr & ~7UL);
464 #elif BITS_PER_LONG == 32
465 *bit += ((unsigned long) addr & 3UL) << 3;
466 addr = (void *) ((unsigned long) addr & ~3UL);
468 #error "how many bits you are?!"
473 static inline int mb_test_bit(int bit, void *addr)
476 * ext4_test_bit on architecture like powerpc
477 * needs unsigned long aligned address
479 addr = mb_correct_addr_and_bit(&bit, addr);
480 return ext4_test_bit(bit, addr);
483 static inline void mb_set_bit(int bit, void *addr)
485 addr = mb_correct_addr_and_bit(&bit, addr);
486 ext4_set_bit(bit, addr);
489 static inline void mb_clear_bit(int bit, void *addr)
491 addr = mb_correct_addr_and_bit(&bit, addr);
492 ext4_clear_bit(bit, addr);
495 static inline int mb_test_and_clear_bit(int bit, void *addr)
497 addr = mb_correct_addr_and_bit(&bit, addr);
498 return ext4_test_and_clear_bit(bit, addr);
501 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
503 int fix = 0, ret, tmpmax;
504 addr = mb_correct_addr_and_bit(&fix, addr);
508 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
514 static inline int mb_find_next_bit(void *addr, int max, int start)
516 int fix = 0, ret, tmpmax;
517 addr = mb_correct_addr_and_bit(&fix, addr);
521 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
527 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
531 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
534 if (order > e4b->bd_blkbits + 1) {
539 /* at order 0 we see each particular block */
541 *max = 1 << (e4b->bd_blkbits + 3);
542 return e4b->bd_bitmap;
545 bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
546 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
552 static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
553 int first, int count)
556 struct super_block *sb = e4b->bd_sb;
558 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
560 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
561 for (i = 0; i < count; i++) {
562 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
563 ext4_fsblk_t blocknr;
565 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
566 blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
567 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
568 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
569 ext4_grp_locked_error(sb, e4b->bd_group,
570 inode ? inode->i_ino : 0,
572 "freeing block already freed "
576 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
580 static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
584 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
586 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
587 for (i = 0; i < count; i++) {
588 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
589 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
593 static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
595 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
597 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
598 unsigned char *b1, *b2;
600 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
601 b2 = (unsigned char *) bitmap;
602 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
603 if (b1[i] != b2[i]) {
604 ext4_msg(e4b->bd_sb, KERN_ERR,
605 "corruption in group %u "
606 "at byte %u(%u): %x in copy != %x "
608 e4b->bd_group, i, i * 8, b1[i], b2[i]);
615 static void mb_group_bb_bitmap_alloc(struct super_block *sb,
616 struct ext4_group_info *grp, ext4_group_t group)
618 struct buffer_head *bh;
620 grp->bb_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS);
624 bh = ext4_read_block_bitmap(sb, group);
625 if (IS_ERR_OR_NULL(bh)) {
626 kfree(grp->bb_bitmap);
627 grp->bb_bitmap = NULL;
631 memcpy(grp->bb_bitmap, bh->b_data, sb->s_blocksize);
635 static void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
637 kfree(grp->bb_bitmap);
641 static inline void mb_free_blocks_double(struct inode *inode,
642 struct ext4_buddy *e4b, int first, int count)
646 static inline void mb_mark_used_double(struct ext4_buddy *e4b,
647 int first, int count)
651 static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
656 static inline void mb_group_bb_bitmap_alloc(struct super_block *sb,
657 struct ext4_group_info *grp, ext4_group_t group)
662 static inline void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
668 #ifdef AGGRESSIVE_CHECK
670 #define MB_CHECK_ASSERT(assert) \
674 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
675 function, file, line, # assert); \
680 static void __mb_check_buddy(struct ext4_buddy *e4b, char *file,
681 const char *function, int line)
683 struct super_block *sb = e4b->bd_sb;
684 int order = e4b->bd_blkbits + 1;
691 struct ext4_group_info *grp;
694 struct list_head *cur;
698 if (e4b->bd_info->bb_check_counter++ % 10)
702 buddy = mb_find_buddy(e4b, order, &max);
703 MB_CHECK_ASSERT(buddy);
704 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
705 MB_CHECK_ASSERT(buddy2);
706 MB_CHECK_ASSERT(buddy != buddy2);
707 MB_CHECK_ASSERT(max * 2 == max2);
710 for (i = 0; i < max; i++) {
712 if (mb_test_bit(i, buddy)) {
713 /* only single bit in buddy2 may be 0 */
714 if (!mb_test_bit(i << 1, buddy2)) {
716 mb_test_bit((i<<1)+1, buddy2));
721 /* both bits in buddy2 must be 1 */
722 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
723 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
725 for (j = 0; j < (1 << order); j++) {
726 k = (i * (1 << order)) + j;
728 !mb_test_bit(k, e4b->bd_bitmap));
732 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
737 buddy = mb_find_buddy(e4b, 0, &max);
738 for (i = 0; i < max; i++) {
739 if (!mb_test_bit(i, buddy)) {
740 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
748 /* check used bits only */
749 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
750 buddy2 = mb_find_buddy(e4b, j, &max2);
752 MB_CHECK_ASSERT(k < max2);
753 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
756 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
757 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
759 grp = ext4_get_group_info(sb, e4b->bd_group);
762 list_for_each(cur, &grp->bb_prealloc_list) {
763 ext4_group_t groupnr;
764 struct ext4_prealloc_space *pa;
765 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
766 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
767 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
768 for (i = 0; i < pa->pa_len; i++)
769 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
772 #undef MB_CHECK_ASSERT
773 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
774 __FILE__, __func__, __LINE__)
776 #define mb_check_buddy(e4b)
780 * Divide blocks started from @first with length @len into
781 * smaller chunks with power of 2 blocks.
782 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
783 * then increase bb_counters[] for corresponded chunk size.
785 static void ext4_mb_mark_free_simple(struct super_block *sb,
786 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
787 struct ext4_group_info *grp)
789 struct ext4_sb_info *sbi = EXT4_SB(sb);
795 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
797 border = 2 << sb->s_blocksize_bits;
800 /* find how many blocks can be covered since this position */
801 max = ffs(first | border) - 1;
803 /* find how many blocks of power 2 we need to mark */
810 /* mark multiblock chunks only */
811 grp->bb_counters[min]++;
813 mb_clear_bit(first >> min,
814 buddy + sbi->s_mb_offsets[min]);
821 static int mb_avg_fragment_size_order(struct super_block *sb, ext4_grpblk_t len)
826 * We don't bother with a special lists groups with only 1 block free
827 * extents and for completely empty groups.
829 order = fls(len) - 2;
832 if (order == MB_NUM_ORDERS(sb))
837 /* Move group to appropriate avg_fragment_size list */
839 mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
841 struct ext4_sb_info *sbi = EXT4_SB(sb);
844 if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0)
847 new_order = mb_avg_fragment_size_order(sb,
848 grp->bb_free / grp->bb_fragments);
849 if (new_order == grp->bb_avg_fragment_size_order)
852 if (grp->bb_avg_fragment_size_order != -1) {
853 write_lock(&sbi->s_mb_avg_fragment_size_locks[
854 grp->bb_avg_fragment_size_order]);
855 list_del(&grp->bb_avg_fragment_size_node);
856 write_unlock(&sbi->s_mb_avg_fragment_size_locks[
857 grp->bb_avg_fragment_size_order]);
859 grp->bb_avg_fragment_size_order = new_order;
860 write_lock(&sbi->s_mb_avg_fragment_size_locks[
861 grp->bb_avg_fragment_size_order]);
862 list_add_tail(&grp->bb_avg_fragment_size_node,
863 &sbi->s_mb_avg_fragment_size[grp->bb_avg_fragment_size_order]);
864 write_unlock(&sbi->s_mb_avg_fragment_size_locks[
865 grp->bb_avg_fragment_size_order]);
869 * Choose next group by traversing largest_free_order lists. Updates *new_cr if
870 * cr level needs an update.
872 static void ext4_mb_choose_next_group_p2_aligned(struct ext4_allocation_context *ac,
873 enum criteria *new_cr, ext4_group_t *group)
875 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
876 struct ext4_group_info *iter;
879 if (ac->ac_status == AC_STATUS_FOUND)
882 if (unlikely(sbi->s_mb_stats && ac->ac_flags & EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED))
883 atomic_inc(&sbi->s_bal_p2_aligned_bad_suggestions);
885 for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) {
886 if (list_empty(&sbi->s_mb_largest_free_orders[i]))
888 read_lock(&sbi->s_mb_largest_free_orders_locks[i]);
889 if (list_empty(&sbi->s_mb_largest_free_orders[i])) {
890 read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
893 list_for_each_entry(iter, &sbi->s_mb_largest_free_orders[i],
894 bb_largest_free_order_node) {
896 atomic64_inc(&sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED]);
897 if (likely(ext4_mb_good_group(ac, iter->bb_group, CR_POWER2_ALIGNED))) {
898 *group = iter->bb_group;
899 ac->ac_flags |= EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED;
900 read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
904 read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
907 /* Increment cr and search again if no group is found */
908 *new_cr = CR_GOAL_LEN_FAST;
912 * Find a suitable group of given order from the average fragments list.
914 static struct ext4_group_info *
915 ext4_mb_find_good_group_avg_frag_lists(struct ext4_allocation_context *ac, int order)
917 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
918 struct list_head *frag_list = &sbi->s_mb_avg_fragment_size[order];
919 rwlock_t *frag_list_lock = &sbi->s_mb_avg_fragment_size_locks[order];
920 struct ext4_group_info *grp = NULL, *iter;
921 enum criteria cr = ac->ac_criteria;
923 if (list_empty(frag_list))
925 read_lock(frag_list_lock);
926 if (list_empty(frag_list)) {
927 read_unlock(frag_list_lock);
930 list_for_each_entry(iter, frag_list, bb_avg_fragment_size_node) {
932 atomic64_inc(&sbi->s_bal_cX_groups_considered[cr]);
933 if (likely(ext4_mb_good_group(ac, iter->bb_group, cr))) {
938 read_unlock(frag_list_lock);
943 * Choose next group by traversing average fragment size list of suitable
944 * order. Updates *new_cr if cr level needs an update.
946 static void ext4_mb_choose_next_group_goal_fast(struct ext4_allocation_context *ac,
947 enum criteria *new_cr, ext4_group_t *group)
949 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
950 struct ext4_group_info *grp = NULL;
953 if (unlikely(ac->ac_flags & EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED)) {
955 atomic_inc(&sbi->s_bal_goal_fast_bad_suggestions);
958 for (i = mb_avg_fragment_size_order(ac->ac_sb, ac->ac_g_ex.fe_len);
959 i < MB_NUM_ORDERS(ac->ac_sb); i++) {
960 grp = ext4_mb_find_good_group_avg_frag_lists(ac, i);
962 *group = grp->bb_group;
963 ac->ac_flags |= EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED;
969 * CR_BEST_AVAIL_LEN works based on the concept that we have
970 * a larger normalized goal len request which can be trimmed to
971 * a smaller goal len such that it can still satisfy original
972 * request len. However, allocation request for non-regular
973 * files never gets normalized.
974 * See function ext4_mb_normalize_request() (EXT4_MB_HINT_DATA).
976 if (ac->ac_flags & EXT4_MB_HINT_DATA)
977 *new_cr = CR_BEST_AVAIL_LEN;
979 *new_cr = CR_GOAL_LEN_SLOW;
983 * We couldn't find a group in CR_GOAL_LEN_FAST so try to find the highest free fragment
984 * order we have and proactively trim the goal request length to that order to
985 * find a suitable group faster.
987 * This optimizes allocation speed at the cost of slightly reduced
988 * preallocations. However, we make sure that we don't trim the request too
989 * much and fall to CR_GOAL_LEN_SLOW in that case.
991 static void ext4_mb_choose_next_group_best_avail(struct ext4_allocation_context *ac,
992 enum criteria *new_cr, ext4_group_t *group)
994 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
995 struct ext4_group_info *grp = NULL;
996 int i, order, min_order;
997 unsigned long num_stripe_clusters = 0;
999 if (unlikely(ac->ac_flags & EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED)) {
1000 if (sbi->s_mb_stats)
1001 atomic_inc(&sbi->s_bal_best_avail_bad_suggestions);
1005 * mb_avg_fragment_size_order() returns order in a way that makes
1006 * retrieving back the length using (1 << order) inaccurate. Hence, use
1007 * fls() instead since we need to know the actual length while modifying
1010 order = fls(ac->ac_g_ex.fe_len) - 1;
1011 min_order = order - sbi->s_mb_best_avail_max_trim_order;
1015 if (sbi->s_stripe > 0) {
1017 * We are assuming that stripe size is always a multiple of
1018 * cluster ratio otherwise __ext4_fill_super exists early.
1020 num_stripe_clusters = EXT4_NUM_B2C(sbi, sbi->s_stripe);
1021 if (1 << min_order < num_stripe_clusters)
1023 * We consider 1 order less because later we round
1024 * up the goal len to num_stripe_clusters
1026 min_order = fls(num_stripe_clusters) - 1;
1029 if (1 << min_order < ac->ac_o_ex.fe_len)
1030 min_order = fls(ac->ac_o_ex.fe_len);
1032 for (i = order; i >= min_order; i--) {
1035 * Scale down goal len to make sure we find something
1036 * in the free fragments list. Basically, reduce
1039 ac->ac_g_ex.fe_len = 1 << i;
1041 if (num_stripe_clusters > 0) {
1043 * Try to round up the adjusted goal length to
1044 * stripe size (in cluster units) multiple for
1047 ac->ac_g_ex.fe_len = roundup(ac->ac_g_ex.fe_len,
1048 num_stripe_clusters);
1051 frag_order = mb_avg_fragment_size_order(ac->ac_sb,
1052 ac->ac_g_ex.fe_len);
1054 grp = ext4_mb_find_good_group_avg_frag_lists(ac, frag_order);
1056 *group = grp->bb_group;
1057 ac->ac_flags |= EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED;
1062 /* Reset goal length to original goal length before falling into CR_GOAL_LEN_SLOW */
1063 ac->ac_g_ex.fe_len = ac->ac_orig_goal_len;
1064 *new_cr = CR_GOAL_LEN_SLOW;
1067 static inline int should_optimize_scan(struct ext4_allocation_context *ac)
1069 if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN)))
1071 if (ac->ac_criteria >= CR_GOAL_LEN_SLOW)
1073 if (!ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))
1079 * Return next linear group for allocation. If linear traversal should not be
1080 * performed, this function just returns the same group
1083 next_linear_group(struct ext4_allocation_context *ac, ext4_group_t group,
1084 ext4_group_t ngroups)
1086 if (!should_optimize_scan(ac))
1087 goto inc_and_return;
1089 if (ac->ac_groups_linear_remaining) {
1090 ac->ac_groups_linear_remaining--;
1091 goto inc_and_return;
1097 * Artificially restricted ngroups for non-extent
1098 * files makes group > ngroups possible on first loop.
1100 return group + 1 >= ngroups ? 0 : group + 1;
1104 * ext4_mb_choose_next_group: choose next group for allocation.
1106 * @ac Allocation Context
1107 * @new_cr This is an output parameter. If the there is no good group
1108 * available at current CR level, this field is updated to indicate
1109 * the new cr level that should be used.
1110 * @group This is an input / output parameter. As an input it indicates the
1111 * next group that the allocator intends to use for allocation. As
1112 * output, this field indicates the next group that should be used as
1113 * determined by the optimization functions.
1114 * @ngroups Total number of groups
1116 static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac,
1117 enum criteria *new_cr, ext4_group_t *group, ext4_group_t ngroups)
1119 *new_cr = ac->ac_criteria;
1121 if (!should_optimize_scan(ac) || ac->ac_groups_linear_remaining) {
1122 *group = next_linear_group(ac, *group, ngroups);
1126 if (*new_cr == CR_POWER2_ALIGNED) {
1127 ext4_mb_choose_next_group_p2_aligned(ac, new_cr, group);
1128 } else if (*new_cr == CR_GOAL_LEN_FAST) {
1129 ext4_mb_choose_next_group_goal_fast(ac, new_cr, group);
1130 } else if (*new_cr == CR_BEST_AVAIL_LEN) {
1131 ext4_mb_choose_next_group_best_avail(ac, new_cr, group);
1134 * TODO: For CR=2, we can arrange groups in an rb tree sorted by
1135 * bb_free. But until that happens, we should never come here.
1142 * Cache the order of the largest free extent we have available in this block
1146 mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
1148 struct ext4_sb_info *sbi = EXT4_SB(sb);
1151 for (i = MB_NUM_ORDERS(sb) - 1; i >= 0; i--)
1152 if (grp->bb_counters[i] > 0)
1154 /* No need to move between order lists? */
1155 if (!test_opt2(sb, MB_OPTIMIZE_SCAN) ||
1156 i == grp->bb_largest_free_order) {
1157 grp->bb_largest_free_order = i;
1161 if (grp->bb_largest_free_order >= 0) {
1162 write_lock(&sbi->s_mb_largest_free_orders_locks[
1163 grp->bb_largest_free_order]);
1164 list_del_init(&grp->bb_largest_free_order_node);
1165 write_unlock(&sbi->s_mb_largest_free_orders_locks[
1166 grp->bb_largest_free_order]);
1168 grp->bb_largest_free_order = i;
1169 if (grp->bb_largest_free_order >= 0 && grp->bb_free) {
1170 write_lock(&sbi->s_mb_largest_free_orders_locks[
1171 grp->bb_largest_free_order]);
1172 list_add_tail(&grp->bb_largest_free_order_node,
1173 &sbi->s_mb_largest_free_orders[grp->bb_largest_free_order]);
1174 write_unlock(&sbi->s_mb_largest_free_orders_locks[
1175 grp->bb_largest_free_order]);
1179 static noinline_for_stack
1180 void ext4_mb_generate_buddy(struct super_block *sb,
1181 void *buddy, void *bitmap, ext4_group_t group,
1182 struct ext4_group_info *grp)
1184 struct ext4_sb_info *sbi = EXT4_SB(sb);
1185 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
1186 ext4_grpblk_t i = 0;
1187 ext4_grpblk_t first;
1190 unsigned fragments = 0;
1191 unsigned long long period = get_cycles();
1193 /* initialize buddy from bitmap which is aggregation
1194 * of on-disk bitmap and preallocations */
1195 i = mb_find_next_zero_bit(bitmap, max, 0);
1196 grp->bb_first_free = i;
1200 i = mb_find_next_bit(bitmap, max, i);
1204 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
1206 grp->bb_counters[0]++;
1208 i = mb_find_next_zero_bit(bitmap, max, i);
1210 grp->bb_fragments = fragments;
1212 if (free != grp->bb_free) {
1213 ext4_grp_locked_error(sb, group, 0, 0,
1214 "block bitmap and bg descriptor "
1215 "inconsistent: %u vs %u free clusters",
1216 free, grp->bb_free);
1218 * If we intend to continue, we consider group descriptor
1219 * corrupt and update bb_free using bitmap value
1221 grp->bb_free = free;
1222 ext4_mark_group_bitmap_corrupted(sb, group,
1223 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1225 mb_set_largest_free_order(sb, grp);
1226 mb_update_avg_fragment_size(sb, grp);
1228 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
1230 period = get_cycles() - period;
1231 atomic_inc(&sbi->s_mb_buddies_generated);
1232 atomic64_add(period, &sbi->s_mb_generation_time);
1235 static void mb_regenerate_buddy(struct ext4_buddy *e4b)
1241 while ((buddy = mb_find_buddy(e4b, order++, &count)))
1242 mb_set_bits(buddy, 0, count);
1244 e4b->bd_info->bb_fragments = 0;
1245 memset(e4b->bd_info->bb_counters, 0,
1246 sizeof(*e4b->bd_info->bb_counters) *
1247 (e4b->bd_sb->s_blocksize_bits + 2));
1249 ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy,
1250 e4b->bd_bitmap, e4b->bd_group, e4b->bd_info);
1253 /* The buddy information is attached the buddy cache inode
1254 * for convenience. The information regarding each group
1255 * is loaded via ext4_mb_load_buddy. The information involve
1256 * block bitmap and buddy information. The information are
1257 * stored in the inode as
1260 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
1263 * one block each for bitmap and buddy information.
1264 * So for each group we take up 2 blocks. A page can
1265 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
1266 * So it can have information regarding groups_per_page which
1267 * is blocks_per_page/2
1269 * Locking note: This routine takes the block group lock of all groups
1270 * for this page; do not hold this lock when calling this routine!
1273 static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
1275 ext4_group_t ngroups;
1276 unsigned int blocksize;
1277 int blocks_per_page;
1278 int groups_per_page;
1281 ext4_group_t first_group, group;
1283 struct super_block *sb;
1284 struct buffer_head *bhs;
1285 struct buffer_head **bh = NULL;
1286 struct inode *inode;
1289 struct ext4_group_info *grinfo;
1291 inode = page->mapping->host;
1293 ngroups = ext4_get_groups_count(sb);
1294 blocksize = i_blocksize(inode);
1295 blocks_per_page = PAGE_SIZE / blocksize;
1297 mb_debug(sb, "init page %lu\n", page->index);
1299 groups_per_page = blocks_per_page >> 1;
1300 if (groups_per_page == 0)
1301 groups_per_page = 1;
1303 /* allocate buffer_heads to read bitmaps */
1304 if (groups_per_page > 1) {
1305 i = sizeof(struct buffer_head *) * groups_per_page;
1306 bh = kzalloc(i, gfp);
1312 first_group = page->index * blocks_per_page / 2;
1314 /* read all groups the page covers into the cache */
1315 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1316 if (group >= ngroups)
1319 grinfo = ext4_get_group_info(sb, group);
1323 * If page is uptodate then we came here after online resize
1324 * which added some new uninitialized group info structs, so
1325 * we must skip all initialized uptodate buddies on the page,
1326 * which may be currently in use by an allocating task.
1328 if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
1332 bh[i] = ext4_read_block_bitmap_nowait(sb, group, false);
1333 if (IS_ERR(bh[i])) {
1334 err = PTR_ERR(bh[i]);
1338 mb_debug(sb, "read bitmap for group %u\n", group);
1341 /* wait for I/O completion */
1342 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1347 err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
1352 first_block = page->index * blocks_per_page;
1353 for (i = 0; i < blocks_per_page; i++) {
1354 group = (first_block + i) >> 1;
1355 if (group >= ngroups)
1358 if (!bh[group - first_group])
1359 /* skip initialized uptodate buddy */
1362 if (!buffer_verified(bh[group - first_group]))
1363 /* Skip faulty bitmaps */
1368 * data carry information regarding this
1369 * particular group in the format specified
1373 data = page_address(page) + (i * blocksize);
1374 bitmap = bh[group - first_group]->b_data;
1377 * We place the buddy block and bitmap block
1380 grinfo = ext4_get_group_info(sb, group);
1382 err = -EFSCORRUPTED;
1385 if ((first_block + i) & 1) {
1386 /* this is block of buddy */
1387 BUG_ON(incore == NULL);
1388 mb_debug(sb, "put buddy for group %u in page %lu/%x\n",
1389 group, page->index, i * blocksize);
1390 trace_ext4_mb_buddy_bitmap_load(sb, group);
1391 grinfo->bb_fragments = 0;
1392 memset(grinfo->bb_counters, 0,
1393 sizeof(*grinfo->bb_counters) *
1394 (MB_NUM_ORDERS(sb)));
1396 * incore got set to the group block bitmap below
1398 ext4_lock_group(sb, group);
1399 /* init the buddy */
1400 memset(data, 0xff, blocksize);
1401 ext4_mb_generate_buddy(sb, data, incore, group, grinfo);
1402 ext4_unlock_group(sb, group);
1405 /* this is block of bitmap */
1406 BUG_ON(incore != NULL);
1407 mb_debug(sb, "put bitmap for group %u in page %lu/%x\n",
1408 group, page->index, i * blocksize);
1409 trace_ext4_mb_bitmap_load(sb, group);
1411 /* see comments in ext4_mb_put_pa() */
1412 ext4_lock_group(sb, group);
1413 memcpy(data, bitmap, blocksize);
1415 /* mark all preallocated blks used in in-core bitmap */
1416 ext4_mb_generate_from_pa(sb, data, group);
1417 WARN_ON_ONCE(!RB_EMPTY_ROOT(&grinfo->bb_free_root));
1418 ext4_unlock_group(sb, group);
1420 /* set incore so that the buddy information can be
1421 * generated using this
1426 SetPageUptodate(page);
1430 for (i = 0; i < groups_per_page; i++)
1439 * Lock the buddy and bitmap pages. This make sure other parallel init_group
1440 * on the same buddy page doesn't happen whild holding the buddy page lock.
1441 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
1442 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
1444 static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
1445 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
1447 struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
1448 int block, pnum, poff;
1449 int blocks_per_page;
1452 e4b->bd_buddy_page = NULL;
1453 e4b->bd_bitmap_page = NULL;
1455 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1457 * the buddy cache inode stores the block bitmap
1458 * and buddy information in consecutive blocks.
1459 * So for each group we need two blocks.
1462 pnum = block / blocks_per_page;
1463 poff = block % blocks_per_page;
1464 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1467 BUG_ON(page->mapping != inode->i_mapping);
1468 e4b->bd_bitmap_page = page;
1469 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1471 if (blocks_per_page >= 2) {
1472 /* buddy and bitmap are on the same page */
1476 /* blocks_per_page == 1, hence we need another page for the buddy */
1477 page = find_or_create_page(inode->i_mapping, block + 1, gfp);
1480 BUG_ON(page->mapping != inode->i_mapping);
1481 e4b->bd_buddy_page = page;
1485 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1487 if (e4b->bd_bitmap_page) {
1488 unlock_page(e4b->bd_bitmap_page);
1489 put_page(e4b->bd_bitmap_page);
1491 if (e4b->bd_buddy_page) {
1492 unlock_page(e4b->bd_buddy_page);
1493 put_page(e4b->bd_buddy_page);
1498 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1499 * block group lock of all groups for this page; do not hold the BG lock when
1500 * calling this routine!
1502 static noinline_for_stack
1503 int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1506 struct ext4_group_info *this_grp;
1507 struct ext4_buddy e4b;
1512 mb_debug(sb, "init group %u\n", group);
1513 this_grp = ext4_get_group_info(sb, group);
1515 return -EFSCORRUPTED;
1518 * This ensures that we don't reinit the buddy cache
1519 * page which map to the group from which we are already
1520 * allocating. If we are looking at the buddy cache we would
1521 * have taken a reference using ext4_mb_load_buddy and that
1522 * would have pinned buddy page to page cache.
1523 * The call to ext4_mb_get_buddy_page_lock will mark the
1526 ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp);
1527 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1529 * somebody initialized the group
1530 * return without doing anything
1535 page = e4b.bd_bitmap_page;
1536 ret = ext4_mb_init_cache(page, NULL, gfp);
1539 if (!PageUptodate(page)) {
1544 if (e4b.bd_buddy_page == NULL) {
1546 * If both the bitmap and buddy are in
1547 * the same page we don't need to force
1553 /* init buddy cache */
1554 page = e4b.bd_buddy_page;
1555 ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp);
1558 if (!PageUptodate(page)) {
1563 ext4_mb_put_buddy_page_lock(&e4b);
1568 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1569 * block group lock of all groups for this page; do not hold the BG lock when
1570 * calling this routine!
1572 static noinline_for_stack int
1573 ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1574 struct ext4_buddy *e4b, gfp_t gfp)
1576 int blocks_per_page;
1582 struct ext4_group_info *grp;
1583 struct ext4_sb_info *sbi = EXT4_SB(sb);
1584 struct inode *inode = sbi->s_buddy_cache;
1587 mb_debug(sb, "load group %u\n", group);
1589 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1590 grp = ext4_get_group_info(sb, group);
1592 return -EFSCORRUPTED;
1594 e4b->bd_blkbits = sb->s_blocksize_bits;
1597 e4b->bd_group = group;
1598 e4b->bd_buddy_page = NULL;
1599 e4b->bd_bitmap_page = NULL;
1601 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1603 * we need full data about the group
1604 * to make a good selection
1606 ret = ext4_mb_init_group(sb, group, gfp);
1612 * the buddy cache inode stores the block bitmap
1613 * and buddy information in consecutive blocks.
1614 * So for each group we need two blocks.
1617 pnum = block / blocks_per_page;
1618 poff = block % blocks_per_page;
1620 /* we could use find_or_create_page(), but it locks page
1621 * what we'd like to avoid in fast path ... */
1622 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1623 if (page == NULL || !PageUptodate(page)) {
1626 * drop the page reference and try
1627 * to get the page with lock. If we
1628 * are not uptodate that implies
1629 * somebody just created the page but
1630 * is yet to initialize the same. So
1631 * wait for it to initialize.
1634 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1636 if (WARN_RATELIMIT(page->mapping != inode->i_mapping,
1637 "ext4: bitmap's paging->mapping != inode->i_mapping\n")) {
1638 /* should never happen */
1643 if (!PageUptodate(page)) {
1644 ret = ext4_mb_init_cache(page, NULL, gfp);
1649 mb_cmp_bitmaps(e4b, page_address(page) +
1650 (poff * sb->s_blocksize));
1659 if (!PageUptodate(page)) {
1664 /* Pages marked accessed already */
1665 e4b->bd_bitmap_page = page;
1666 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1669 pnum = block / blocks_per_page;
1670 poff = block % blocks_per_page;
1672 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1673 if (page == NULL || !PageUptodate(page)) {
1676 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1678 if (WARN_RATELIMIT(page->mapping != inode->i_mapping,
1679 "ext4: buddy bitmap's page->mapping != inode->i_mapping\n")) {
1680 /* should never happen */
1685 if (!PageUptodate(page)) {
1686 ret = ext4_mb_init_cache(page, e4b->bd_bitmap,
1700 if (!PageUptodate(page)) {
1705 /* Pages marked accessed already */
1706 e4b->bd_buddy_page = page;
1707 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1714 if (e4b->bd_bitmap_page)
1715 put_page(e4b->bd_bitmap_page);
1717 e4b->bd_buddy = NULL;
1718 e4b->bd_bitmap = NULL;
1722 static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1723 struct ext4_buddy *e4b)
1725 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1728 static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1730 if (e4b->bd_bitmap_page)
1731 put_page(e4b->bd_bitmap_page);
1732 if (e4b->bd_buddy_page)
1733 put_page(e4b->bd_buddy_page);
1737 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1742 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1743 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1745 while (order <= e4b->bd_blkbits + 1) {
1746 bb = mb_find_buddy(e4b, order, &max);
1747 if (!mb_test_bit(block >> order, bb)) {
1748 /* this block is part of buddy of order 'order' */
1756 static void mb_clear_bits(void *bm, int cur, int len)
1762 if ((cur & 31) == 0 && (len - cur) >= 32) {
1763 /* fast path: clear whole word at once */
1764 addr = bm + (cur >> 3);
1769 mb_clear_bit(cur, bm);
1774 /* clear bits in given range
1775 * will return first found zero bit if any, -1 otherwise
1777 static int mb_test_and_clear_bits(void *bm, int cur, int len)
1784 if ((cur & 31) == 0 && (len - cur) >= 32) {
1785 /* fast path: clear whole word at once */
1786 addr = bm + (cur >> 3);
1787 if (*addr != (__u32)(-1) && zero_bit == -1)
1788 zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0);
1793 if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1)
1801 void mb_set_bits(void *bm, int cur, int len)
1807 if ((cur & 31) == 0 && (len - cur) >= 32) {
1808 /* fast path: set whole word at once */
1809 addr = bm + (cur >> 3);
1814 mb_set_bit(cur, bm);
1819 static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1821 if (mb_test_bit(*bit + side, bitmap)) {
1822 mb_clear_bit(*bit, bitmap);
1828 mb_set_bit(*bit, bitmap);
1833 static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1837 void *buddy = mb_find_buddy(e4b, order, &max);
1842 /* Bits in range [first; last] are known to be set since
1843 * corresponding blocks were allocated. Bits in range
1844 * (first; last) will stay set because they form buddies on
1845 * upper layer. We just deal with borders if they don't
1846 * align with upper layer and then go up.
1847 * Releasing entire group is all about clearing
1848 * single bit of highest order buddy.
1852 * ---------------------------------
1854 * ---------------------------------
1855 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1856 * ---------------------------------
1858 * \_____________________/
1860 * Neither [1] nor [6] is aligned to above layer.
1861 * Left neighbour [0] is free, so mark it busy,
1862 * decrease bb_counters and extend range to
1864 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1865 * mark [6] free, increase bb_counters and shrink range to
1867 * Then shift range to [0; 2], go up and do the same.
1872 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1);
1874 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1);
1879 buddy2 = mb_find_buddy(e4b, order, &max);
1881 mb_clear_bits(buddy, first, last - first + 1);
1882 e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1891 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1892 int first, int count)
1894 int left_is_free = 0;
1895 int right_is_free = 0;
1897 int last = first + count - 1;
1898 struct super_block *sb = e4b->bd_sb;
1900 if (WARN_ON(count == 0))
1902 BUG_ON(last >= (sb->s_blocksize << 3));
1903 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1904 /* Don't bother if the block group is corrupt. */
1905 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1908 mb_check_buddy(e4b);
1909 mb_free_blocks_double(inode, e4b, first, count);
1911 /* access memory sequentially: check left neighbour,
1912 * clear range and then check right neighbour
1915 left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap);
1916 block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count);
1917 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1918 right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap);
1920 if (unlikely(block != -1)) {
1921 struct ext4_sb_info *sbi = EXT4_SB(sb);
1922 ext4_fsblk_t blocknr;
1925 * Fastcommit replay can free already freed blocks which
1926 * corrupts allocation info. Regenerate it.
1928 if (sbi->s_mount_state & EXT4_FC_REPLAY) {
1929 mb_regenerate_buddy(e4b);
1933 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
1934 blocknr += EXT4_C2B(sbi, block);
1935 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
1936 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1937 ext4_grp_locked_error(sb, e4b->bd_group,
1938 inode ? inode->i_ino : 0, blocknr,
1939 "freeing already freed block (bit %u); block bitmap corrupt.",
1944 this_cpu_inc(discard_pa_seq);
1945 e4b->bd_info->bb_free += count;
1946 if (first < e4b->bd_info->bb_first_free)
1947 e4b->bd_info->bb_first_free = first;
1949 /* let's maintain fragments counter */
1950 if (left_is_free && right_is_free)
1951 e4b->bd_info->bb_fragments--;
1952 else if (!left_is_free && !right_is_free)
1953 e4b->bd_info->bb_fragments++;
1955 /* buddy[0] == bd_bitmap is a special case, so handle
1956 * it right away and let mb_buddy_mark_free stay free of
1957 * zero order checks.
1958 * Check if neighbours are to be coaleasced,
1959 * adjust bitmap bb_counters and borders appropriately.
1962 first += !left_is_free;
1963 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
1966 last -= !right_is_free;
1967 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
1971 mb_buddy_mark_free(e4b, first >> 1, last >> 1);
1973 mb_set_largest_free_order(sb, e4b->bd_info);
1974 mb_update_avg_fragment_size(sb, e4b->bd_info);
1976 mb_check_buddy(e4b);
1979 static int mb_find_extent(struct ext4_buddy *e4b, int block,
1980 int needed, struct ext4_free_extent *ex)
1982 int max, order, next;
1985 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1988 buddy = mb_find_buddy(e4b, 0, &max);
1989 BUG_ON(buddy == NULL);
1990 BUG_ON(block >= max);
1991 if (mb_test_bit(block, buddy)) {
1998 /* find actual order */
1999 order = mb_find_order_for_block(e4b, block);
2001 ex->fe_len = (1 << order) - (block & ((1 << order) - 1));
2002 ex->fe_start = block;
2003 ex->fe_group = e4b->bd_group;
2005 block = block >> order;
2007 while (needed > ex->fe_len &&
2008 mb_find_buddy(e4b, order, &max)) {
2010 if (block + 1 >= max)
2013 next = (block + 1) * (1 << order);
2014 if (mb_test_bit(next, e4b->bd_bitmap))
2017 order = mb_find_order_for_block(e4b, next);
2019 block = next >> order;
2020 ex->fe_len += 1 << order;
2023 if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
2024 /* Should never happen! (but apparently sometimes does?!?) */
2026 ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0,
2027 "corruption or bug in mb_find_extent "
2028 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
2029 block, order, needed, ex->fe_group, ex->fe_start,
2030 ex->fe_len, ex->fe_logical);
2038 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
2044 int start = ex->fe_start;
2045 int len = ex->fe_len;
2051 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
2052 BUG_ON(e4b->bd_group != ex->fe_group);
2053 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
2054 mb_check_buddy(e4b);
2055 mb_mark_used_double(e4b, start, len);
2057 this_cpu_inc(discard_pa_seq);
2058 e4b->bd_info->bb_free -= len;
2059 if (e4b->bd_info->bb_first_free == start)
2060 e4b->bd_info->bb_first_free += len;
2062 /* let's maintain fragments counter */
2064 mlen = !mb_test_bit(start - 1, e4b->bd_bitmap);
2065 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
2066 max = !mb_test_bit(start + len, e4b->bd_bitmap);
2068 e4b->bd_info->bb_fragments++;
2069 else if (!mlen && !max)
2070 e4b->bd_info->bb_fragments--;
2072 /* let's maintain buddy itself */
2075 ord = mb_find_order_for_block(e4b, start);
2077 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
2078 /* the whole chunk may be allocated at once! */
2081 buddy = mb_find_buddy(e4b, ord, &max);
2084 BUG_ON((start >> ord) >= max);
2085 mb_set_bit(start >> ord, buddy);
2086 e4b->bd_info->bb_counters[ord]--;
2093 /* store for history */
2095 ret = len | (ord << 16);
2097 /* we have to split large buddy */
2099 buddy = mb_find_buddy(e4b, ord, &max);
2100 mb_set_bit(start >> ord, buddy);
2101 e4b->bd_info->bb_counters[ord]--;
2104 cur = (start >> ord) & ~1U;
2105 buddy = mb_find_buddy(e4b, ord, &max);
2106 mb_clear_bit(cur, buddy);
2107 mb_clear_bit(cur + 1, buddy);
2108 e4b->bd_info->bb_counters[ord]++;
2109 e4b->bd_info->bb_counters[ord]++;
2112 mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
2114 mb_update_avg_fragment_size(e4b->bd_sb, e4b->bd_info);
2115 mb_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
2116 mb_check_buddy(e4b);
2122 * Must be called under group lock!
2124 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
2125 struct ext4_buddy *e4b)
2127 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2130 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
2131 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2133 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
2134 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
2135 ret = mb_mark_used(e4b, &ac->ac_b_ex);
2137 /* preallocation can change ac_b_ex, thus we store actually
2138 * allocated blocks for history */
2139 ac->ac_f_ex = ac->ac_b_ex;
2141 ac->ac_status = AC_STATUS_FOUND;
2142 ac->ac_tail = ret & 0xffff;
2143 ac->ac_buddy = ret >> 16;
2146 * take the page reference. We want the page to be pinned
2147 * so that we don't get a ext4_mb_init_cache_call for this
2148 * group until we update the bitmap. That would mean we
2149 * double allocate blocks. The reference is dropped
2150 * in ext4_mb_release_context
2152 ac->ac_bitmap_page = e4b->bd_bitmap_page;
2153 get_page(ac->ac_bitmap_page);
2154 ac->ac_buddy_page = e4b->bd_buddy_page;
2155 get_page(ac->ac_buddy_page);
2156 /* store last allocated for subsequent stream allocation */
2157 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2158 spin_lock(&sbi->s_md_lock);
2159 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
2160 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
2161 spin_unlock(&sbi->s_md_lock);
2164 * As we've just preallocated more space than
2165 * user requested originally, we store allocated
2166 * space in a special descriptor.
2168 if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
2169 ext4_mb_new_preallocation(ac);
2173 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
2174 struct ext4_buddy *e4b,
2177 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2178 struct ext4_free_extent *bex = &ac->ac_b_ex;
2179 struct ext4_free_extent *gex = &ac->ac_g_ex;
2181 if (ac->ac_status == AC_STATUS_FOUND)
2184 * We don't want to scan for a whole year
2186 if (ac->ac_found > sbi->s_mb_max_to_scan &&
2187 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2188 ac->ac_status = AC_STATUS_BREAK;
2193 * Haven't found good chunk so far, let's continue
2195 if (bex->fe_len < gex->fe_len)
2198 if (finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
2199 ext4_mb_use_best_found(ac, e4b);
2203 * The routine checks whether found extent is good enough. If it is,
2204 * then the extent gets marked used and flag is set to the context
2205 * to stop scanning. Otherwise, the extent is compared with the
2206 * previous found extent and if new one is better, then it's stored
2207 * in the context. Later, the best found extent will be used, if
2208 * mballoc can't find good enough extent.
2210 * The algorithm used is roughly as follows:
2212 * * If free extent found is exactly as big as goal, then
2213 * stop the scan and use it immediately
2215 * * If free extent found is smaller than goal, then keep retrying
2216 * upto a max of sbi->s_mb_max_to_scan times (default 200). After
2217 * that stop scanning and use whatever we have.
2219 * * If free extent found is bigger than goal, then keep retrying
2220 * upto a max of sbi->s_mb_min_to_scan times (default 10) before
2221 * stopping the scan and using the extent.
2224 * FIXME: real allocation policy is to be designed yet!
2226 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
2227 struct ext4_free_extent *ex,
2228 struct ext4_buddy *e4b)
2230 struct ext4_free_extent *bex = &ac->ac_b_ex;
2231 struct ext4_free_extent *gex = &ac->ac_g_ex;
2233 BUG_ON(ex->fe_len <= 0);
2234 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2235 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2236 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
2239 ac->ac_cX_found[ac->ac_criteria]++;
2242 * The special case - take what you catch first
2244 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2246 ext4_mb_use_best_found(ac, e4b);
2251 * Let's check whether the chuck is good enough
2253 if (ex->fe_len == gex->fe_len) {
2255 ext4_mb_use_best_found(ac, e4b);
2260 * If this is first found extent, just store it in the context
2262 if (bex->fe_len == 0) {
2268 * If new found extent is better, store it in the context
2270 if (bex->fe_len < gex->fe_len) {
2271 /* if the request isn't satisfied, any found extent
2272 * larger than previous best one is better */
2273 if (ex->fe_len > bex->fe_len)
2275 } else if (ex->fe_len > gex->fe_len) {
2276 /* if the request is satisfied, then we try to find
2277 * an extent that still satisfy the request, but is
2278 * smaller than previous one */
2279 if (ex->fe_len < bex->fe_len)
2283 ext4_mb_check_limits(ac, e4b, 0);
2286 static noinline_for_stack
2287 void ext4_mb_try_best_found(struct ext4_allocation_context *ac,
2288 struct ext4_buddy *e4b)
2290 struct ext4_free_extent ex = ac->ac_b_ex;
2291 ext4_group_t group = ex.fe_group;
2295 BUG_ON(ex.fe_len <= 0);
2296 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
2300 ext4_lock_group(ac->ac_sb, group);
2301 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
2304 max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex);
2308 ext4_mb_use_best_found(ac, e4b);
2312 ext4_unlock_group(ac->ac_sb, group);
2313 ext4_mb_unload_buddy(e4b);
2316 static noinline_for_stack
2317 int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
2318 struct ext4_buddy *e4b)
2320 ext4_group_t group = ac->ac_g_ex.fe_group;
2323 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2324 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2325 struct ext4_free_extent ex;
2328 return -EFSCORRUPTED;
2329 if (!(ac->ac_flags & (EXT4_MB_HINT_TRY_GOAL | EXT4_MB_HINT_GOAL_ONLY)))
2331 if (grp->bb_free == 0)
2334 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
2338 ext4_lock_group(ac->ac_sb, group);
2339 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
2342 max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
2343 ac->ac_g_ex.fe_len, &ex);
2344 ex.fe_logical = 0xDEADFA11; /* debug value */
2346 if (max >= ac->ac_g_ex.fe_len &&
2347 ac->ac_g_ex.fe_len == EXT4_B2C(sbi, sbi->s_stripe)) {
2350 start = ext4_grp_offs_to_block(ac->ac_sb, &ex);
2351 /* use do_div to get remainder (would be 64-bit modulo) */
2352 if (do_div(start, sbi->s_stripe) == 0) {
2355 ext4_mb_use_best_found(ac, e4b);
2357 } else if (max >= ac->ac_g_ex.fe_len) {
2358 BUG_ON(ex.fe_len <= 0);
2359 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2360 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2363 ext4_mb_use_best_found(ac, e4b);
2364 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
2365 /* Sometimes, caller may want to merge even small
2366 * number of blocks to an existing extent */
2367 BUG_ON(ex.fe_len <= 0);
2368 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2369 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2372 ext4_mb_use_best_found(ac, e4b);
2375 ext4_unlock_group(ac->ac_sb, group);
2376 ext4_mb_unload_buddy(e4b);
2382 * The routine scans buddy structures (not bitmap!) from given order
2383 * to max order and tries to find big enough chunk to satisfy the req
2385 static noinline_for_stack
2386 void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
2387 struct ext4_buddy *e4b)
2389 struct super_block *sb = ac->ac_sb;
2390 struct ext4_group_info *grp = e4b->bd_info;
2396 BUG_ON(ac->ac_2order <= 0);
2397 for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) {
2398 if (grp->bb_counters[i] == 0)
2401 buddy = mb_find_buddy(e4b, i, &max);
2402 if (WARN_RATELIMIT(buddy == NULL,
2403 "ext4: mb_simple_scan_group: mb_find_buddy failed, (%d)\n", i))
2406 k = mb_find_next_zero_bit(buddy, max, 0);
2408 ext4_mark_group_bitmap_corrupted(ac->ac_sb,
2410 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2411 ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0,
2412 "%d free clusters of order %d. But found 0",
2413 grp->bb_counters[i], i);
2417 ac->ac_cX_found[ac->ac_criteria]++;
2419 ac->ac_b_ex.fe_len = 1 << i;
2420 ac->ac_b_ex.fe_start = k << i;
2421 ac->ac_b_ex.fe_group = e4b->bd_group;
2423 ext4_mb_use_best_found(ac, e4b);
2425 BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len);
2427 if (EXT4_SB(sb)->s_mb_stats)
2428 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
2435 * The routine scans the group and measures all found extents.
2436 * In order to optimize scanning, caller must pass number of
2437 * free blocks in the group, so the routine can know upper limit.
2439 static noinline_for_stack
2440 void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
2441 struct ext4_buddy *e4b)
2443 struct super_block *sb = ac->ac_sb;
2444 void *bitmap = e4b->bd_bitmap;
2445 struct ext4_free_extent ex;
2449 free = e4b->bd_info->bb_free;
2450 if (WARN_ON(free <= 0))
2453 i = e4b->bd_info->bb_first_free;
2455 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
2456 i = mb_find_next_zero_bit(bitmap,
2457 EXT4_CLUSTERS_PER_GROUP(sb), i);
2458 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
2460 * IF we have corrupt bitmap, we won't find any
2461 * free blocks even though group info says we
2464 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
2465 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2466 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2467 "%d free clusters as per "
2468 "group info. But bitmap says 0",
2473 if (!ext4_mb_cr_expensive(ac->ac_criteria)) {
2475 * In CR_GOAL_LEN_FAST and CR_BEST_AVAIL_LEN, we are
2476 * sure that this group will have a large enough
2477 * continuous free extent, so skip over the smaller free
2480 j = mb_find_next_bit(bitmap,
2481 EXT4_CLUSTERS_PER_GROUP(sb), i);
2484 if (freelen < ac->ac_g_ex.fe_len) {
2491 mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex);
2492 if (WARN_ON(ex.fe_len <= 0))
2494 if (free < ex.fe_len) {
2495 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
2496 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2497 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2498 "%d free clusters as per "
2499 "group info. But got %d blocks",
2502 * The number of free blocks differs. This mostly
2503 * indicate that the bitmap is corrupt. So exit
2504 * without claiming the space.
2508 ex.fe_logical = 0xDEADC0DE; /* debug value */
2509 ext4_mb_measure_extent(ac, &ex, e4b);
2515 ext4_mb_check_limits(ac, e4b, 1);
2519 * This is a special case for storages like raid5
2520 * we try to find stripe-aligned chunks for stripe-size-multiple requests
2522 static noinline_for_stack
2523 void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
2524 struct ext4_buddy *e4b)
2526 struct super_block *sb = ac->ac_sb;
2527 struct ext4_sb_info *sbi = EXT4_SB(sb);
2528 void *bitmap = e4b->bd_bitmap;
2529 struct ext4_free_extent ex;
2530 ext4_fsblk_t first_group_block;
2532 ext4_grpblk_t i, stripe;
2535 BUG_ON(sbi->s_stripe == 0);
2537 /* find first stripe-aligned block in group */
2538 first_group_block = ext4_group_first_block_no(sb, e4b->bd_group);
2540 a = first_group_block + sbi->s_stripe - 1;
2541 do_div(a, sbi->s_stripe);
2542 i = (a * sbi->s_stripe) - first_group_block;
2544 stripe = EXT4_B2C(sbi, sbi->s_stripe);
2545 i = EXT4_B2C(sbi, i);
2546 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2547 if (!mb_test_bit(i, bitmap)) {
2548 max = mb_find_extent(e4b, i, stripe, &ex);
2549 if (max >= stripe) {
2551 ac->ac_cX_found[ac->ac_criteria]++;
2552 ex.fe_logical = 0xDEADF00D; /* debug value */
2554 ext4_mb_use_best_found(ac, e4b);
2563 * This is also called BEFORE we load the buddy bitmap.
2564 * Returns either 1 or 0 indicating that the group is either suitable
2565 * for the allocation or not.
2567 static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
2568 ext4_group_t group, enum criteria cr)
2570 ext4_grpblk_t free, fragments;
2571 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
2572 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2574 BUG_ON(cr < CR_POWER2_ALIGNED || cr >= EXT4_MB_NUM_CRS);
2576 if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2579 free = grp->bb_free;
2583 fragments = grp->bb_fragments;
2588 case CR_POWER2_ALIGNED:
2589 BUG_ON(ac->ac_2order == 0);
2591 /* Avoid using the first bg of a flexgroup for data files */
2592 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2593 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2594 ((group % flex_size) == 0))
2597 if (free < ac->ac_g_ex.fe_len)
2600 if (ac->ac_2order >= MB_NUM_ORDERS(ac->ac_sb))
2603 if (grp->bb_largest_free_order < ac->ac_2order)
2607 case CR_GOAL_LEN_FAST:
2608 case CR_BEST_AVAIL_LEN:
2609 if ((free / fragments) >= ac->ac_g_ex.fe_len)
2612 case CR_GOAL_LEN_SLOW:
2613 if (free >= ac->ac_g_ex.fe_len)
2626 * This could return negative error code if something goes wrong
2627 * during ext4_mb_init_group(). This should not be called with
2628 * ext4_lock_group() held.
2630 * Note: because we are conditionally operating with the group lock in
2631 * the EXT4_MB_STRICT_CHECK case, we need to fake out sparse in this
2632 * function using __acquire and __release. This means we need to be
2633 * super careful before messing with the error path handling via "goto
2636 static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac,
2637 ext4_group_t group, enum criteria cr)
2639 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2640 struct super_block *sb = ac->ac_sb;
2641 struct ext4_sb_info *sbi = EXT4_SB(sb);
2642 bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK;
2647 return -EFSCORRUPTED;
2648 if (sbi->s_mb_stats)
2649 atomic64_inc(&sbi->s_bal_cX_groups_considered[ac->ac_criteria]);
2651 ext4_lock_group(sb, group);
2652 __release(ext4_group_lock_ptr(sb, group));
2654 free = grp->bb_free;
2658 * In all criterias except CR_ANY_FREE we try to avoid groups that
2659 * can't possibly satisfy the full goal request due to insufficient
2662 if (cr < CR_ANY_FREE && free < ac->ac_g_ex.fe_len)
2664 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2667 __acquire(ext4_group_lock_ptr(sb, group));
2668 ext4_unlock_group(sb, group);
2671 /* We only do this if the grp has never been initialized */
2672 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2673 struct ext4_group_desc *gdp =
2674 ext4_get_group_desc(sb, group, NULL);
2678 * cr=CR_POWER2_ALIGNED/CR_GOAL_LEN_FAST is a very optimistic
2679 * search to find large good chunks almost for free. If buddy
2680 * data is not ready, then this optimization makes no sense. But
2681 * we never skip the first block group in a flex_bg, since this
2682 * gets used for metadata block allocation, and we want to make
2683 * sure we locate metadata blocks in the first block group in
2684 * the flex_bg if possible.
2686 if (!ext4_mb_cr_expensive(cr) &&
2687 (!sbi->s_log_groups_per_flex ||
2688 ((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) &&
2689 !(ext4_has_group_desc_csum(sb) &&
2690 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))))
2692 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
2698 ext4_lock_group(sb, group);
2699 __release(ext4_group_lock_ptr(sb, group));
2701 ret = ext4_mb_good_group(ac, group, cr);
2704 __acquire(ext4_group_lock_ptr(sb, group));
2705 ext4_unlock_group(sb, group);
2711 * Start prefetching @nr block bitmaps starting at @group.
2712 * Return the next group which needs to be prefetched.
2714 ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group,
2715 unsigned int nr, int *cnt)
2717 ext4_group_t ngroups = ext4_get_groups_count(sb);
2718 struct buffer_head *bh;
2719 struct blk_plug plug;
2721 blk_start_plug(&plug);
2723 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group,
2725 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
2728 * Prefetch block groups with free blocks; but don't
2729 * bother if it is marked uninitialized on disk, since
2730 * it won't require I/O to read. Also only try to
2731 * prefetch once, so we avoid getblk() call, which can
2734 if (gdp && grp && !EXT4_MB_GRP_TEST_AND_SET_READ(grp) &&
2735 EXT4_MB_GRP_NEED_INIT(grp) &&
2736 ext4_free_group_clusters(sb, gdp) > 0 ) {
2737 bh = ext4_read_block_bitmap_nowait(sb, group, true);
2738 if (bh && !IS_ERR(bh)) {
2739 if (!buffer_uptodate(bh) && cnt)
2744 if (++group >= ngroups)
2747 blk_finish_plug(&plug);
2752 * Prefetching reads the block bitmap into the buffer cache; but we
2753 * need to make sure that the buddy bitmap in the page cache has been
2754 * initialized. Note that ext4_mb_init_group() will block if the I/O
2755 * is not yet completed, or indeed if it was not initiated by
2756 * ext4_mb_prefetch did not start the I/O.
2758 * TODO: We should actually kick off the buddy bitmap setup in a work
2759 * queue when the buffer I/O is completed, so that we don't block
2760 * waiting for the block allocation bitmap read to finish when
2761 * ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator().
2763 void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
2766 struct ext4_group_desc *gdp;
2767 struct ext4_group_info *grp;
2771 group = ext4_get_groups_count(sb);
2773 gdp = ext4_get_group_desc(sb, group, NULL);
2774 grp = ext4_get_group_info(sb, group);
2776 if (grp && gdp && EXT4_MB_GRP_NEED_INIT(grp) &&
2777 ext4_free_group_clusters(sb, gdp) > 0) {
2778 if (ext4_mb_init_group(sb, group, GFP_NOFS))
2784 static noinline_for_stack int
2785 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2787 ext4_group_t prefetch_grp = 0, ngroups, group, i;
2788 enum criteria new_cr, cr = CR_GOAL_LEN_FAST;
2789 int err = 0, first_err = 0;
2790 unsigned int nr = 0, prefetch_ios = 0;
2791 struct ext4_sb_info *sbi;
2792 struct super_block *sb;
2793 struct ext4_buddy e4b;
2798 ngroups = ext4_get_groups_count(sb);
2799 /* non-extent files are limited to low blocks/groups */
2800 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)))
2801 ngroups = sbi->s_blockfile_groups;
2803 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2805 /* first, try the goal */
2806 err = ext4_mb_find_by_goal(ac, &e4b);
2807 if (err || ac->ac_status == AC_STATUS_FOUND)
2810 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2814 * ac->ac_2order is set only if the fe_len is a power of 2
2815 * if ac->ac_2order is set we also set criteria to CR_POWER2_ALIGNED
2816 * so that we try exact allocation using buddy.
2818 i = fls(ac->ac_g_ex.fe_len);
2821 * We search using buddy data only if the order of the request
2822 * is greater than equal to the sbi_s_mb_order2_reqs
2823 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2824 * We also support searching for power-of-two requests only for
2825 * requests upto maximum buddy size we have constructed.
2827 if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) {
2828 if (is_power_of_2(ac->ac_g_ex.fe_len))
2829 ac->ac_2order = array_index_nospec(i - 1,
2833 /* if stream allocation is enabled, use global goal */
2834 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2835 /* TBD: may be hot point */
2836 spin_lock(&sbi->s_md_lock);
2837 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2838 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2839 spin_unlock(&sbi->s_md_lock);
2843 * Let's just scan groups to find more-less suitable blocks We
2844 * start with CR_GOAL_LEN_FAST, unless it is power of 2
2845 * aligned, in which case let's do that faster approach first.
2848 cr = CR_POWER2_ALIGNED;
2850 for (; cr < EXT4_MB_NUM_CRS && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2851 ac->ac_criteria = cr;
2853 * searching for the right group start
2854 * from the goal value specified
2856 group = ac->ac_g_ex.fe_group;
2857 ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups;
2858 prefetch_grp = group;
2860 for (i = 0, new_cr = cr; i < ngroups; i++,
2861 ext4_mb_choose_next_group(ac, &new_cr, &group, ngroups)) {
2871 * Batch reads of the block allocation bitmaps
2872 * to get multiple READs in flight; limit
2873 * prefetching at inexpensive CR, otherwise mballoc
2874 * can spend a lot of time loading imperfect groups
2876 if ((prefetch_grp == group) &&
2877 (ext4_mb_cr_expensive(cr) ||
2878 prefetch_ios < sbi->s_mb_prefetch_limit)) {
2879 nr = sbi->s_mb_prefetch;
2880 if (ext4_has_feature_flex_bg(sb)) {
2881 nr = 1 << sbi->s_log_groups_per_flex;
2882 nr -= group & (nr - 1);
2883 nr = min(nr, sbi->s_mb_prefetch);
2885 prefetch_grp = ext4_mb_prefetch(sb, group,
2889 /* This now checks without needing the buddy page */
2890 ret = ext4_mb_good_group_nolock(ac, group, cr);
2897 err = ext4_mb_load_buddy(sb, group, &e4b);
2901 ext4_lock_group(sb, group);
2904 * We need to check again after locking the
2907 ret = ext4_mb_good_group(ac, group, cr);
2909 ext4_unlock_group(sb, group);
2910 ext4_mb_unload_buddy(&e4b);
2914 ac->ac_groups_scanned++;
2915 if (cr == CR_POWER2_ALIGNED)
2916 ext4_mb_simple_scan_group(ac, &e4b);
2918 bool is_stripe_aligned = sbi->s_stripe &&
2919 !(ac->ac_g_ex.fe_len %
2920 EXT4_B2C(sbi, sbi->s_stripe));
2922 if ((cr == CR_GOAL_LEN_FAST ||
2923 cr == CR_BEST_AVAIL_LEN) &&
2925 ext4_mb_scan_aligned(ac, &e4b);
2927 if (ac->ac_status == AC_STATUS_CONTINUE)
2928 ext4_mb_complex_scan_group(ac, &e4b);
2931 ext4_unlock_group(sb, group);
2932 ext4_mb_unload_buddy(&e4b);
2934 if (ac->ac_status != AC_STATUS_CONTINUE)
2937 /* Processed all groups and haven't found blocks */
2938 if (sbi->s_mb_stats && i == ngroups)
2939 atomic64_inc(&sbi->s_bal_cX_failed[cr]);
2941 if (i == ngroups && ac->ac_criteria == CR_BEST_AVAIL_LEN)
2942 /* Reset goal length to original goal length before
2943 * falling into CR_GOAL_LEN_SLOW */
2944 ac->ac_g_ex.fe_len = ac->ac_orig_goal_len;
2947 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2948 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2950 * We've been searching too long. Let's try to allocate
2951 * the best chunk we've found so far
2953 ext4_mb_try_best_found(ac, &e4b);
2954 if (ac->ac_status != AC_STATUS_FOUND) {
2956 * Someone more lucky has already allocated it.
2957 * The only thing we can do is just take first
2960 lost = atomic_inc_return(&sbi->s_mb_lost_chunks);
2961 mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n",
2962 ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start,
2963 ac->ac_b_ex.fe_len, lost);
2965 ac->ac_b_ex.fe_group = 0;
2966 ac->ac_b_ex.fe_start = 0;
2967 ac->ac_b_ex.fe_len = 0;
2968 ac->ac_status = AC_STATUS_CONTINUE;
2969 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2975 if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND)
2976 atomic64_inc(&sbi->s_bal_cX_hits[ac->ac_criteria]);
2978 if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
2981 mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
2982 ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status,
2983 ac->ac_flags, cr, err);
2986 ext4_mb_prefetch_fini(sb, prefetch_grp, nr);
2991 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2993 struct super_block *sb = pde_data(file_inode(seq->file));
2996 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2999 return (void *) ((unsigned long) group);
3002 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
3004 struct super_block *sb = pde_data(file_inode(seq->file));
3008 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
3011 return (void *) ((unsigned long) group);
3014 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
3016 struct super_block *sb = pde_data(file_inode(seq->file));
3017 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
3020 struct ext4_buddy e4b;
3021 struct ext4_group_info *grinfo;
3022 unsigned char blocksize_bits = min_t(unsigned char,
3023 sb->s_blocksize_bits,
3024 EXT4_MAX_BLOCK_LOG_SIZE);
3026 struct ext4_group_info info;
3027 ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
3032 seq_puts(seq, "#group: free frags first ["
3033 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
3034 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
3036 i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
3037 sizeof(struct ext4_group_info);
3039 grinfo = ext4_get_group_info(sb, group);
3042 /* Load the group info in memory only if not already loaded. */
3043 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
3044 err = ext4_mb_load_buddy(sb, group, &e4b);
3046 seq_printf(seq, "#%-5u: %s\n", group, ext4_decode_error(NULL, err, nbuf));
3049 ext4_mb_unload_buddy(&e4b);
3053 * We care only about free space counters in the group info and
3054 * these are safe to access even after the buddy has been unloaded
3056 memcpy(&sg, grinfo, i);
3057 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
3058 sg.info.bb_fragments, sg.info.bb_first_free);
3059 for (i = 0; i <= 13; i++)
3060 seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
3061 sg.info.bb_counters[i] : 0);
3062 seq_puts(seq, " ]");
3063 if (EXT4_MB_GRP_BBITMAP_CORRUPT(&sg.info))
3064 seq_puts(seq, " Block bitmap corrupted!");
3065 seq_puts(seq, "\n");
3070 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
3074 const struct seq_operations ext4_mb_seq_groups_ops = {
3075 .start = ext4_mb_seq_groups_start,
3076 .next = ext4_mb_seq_groups_next,
3077 .stop = ext4_mb_seq_groups_stop,
3078 .show = ext4_mb_seq_groups_show,
3081 int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
3083 struct super_block *sb = seq->private;
3084 struct ext4_sb_info *sbi = EXT4_SB(sb);
3086 seq_puts(seq, "mballoc:\n");
3087 if (!sbi->s_mb_stats) {
3088 seq_puts(seq, "\tmb stats collection turned off.\n");
3091 "\tTo enable, please write \"1\" to sysfs file mb_stats.\n");
3094 seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs));
3095 seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success));
3097 seq_printf(seq, "\tgroups_scanned: %u\n",
3098 atomic_read(&sbi->s_bal_groups_scanned));
3100 /* CR_POWER2_ALIGNED stats */
3101 seq_puts(seq, "\tcr_p2_aligned_stats:\n");
3102 seq_printf(seq, "\t\thits: %llu\n",
3103 atomic64_read(&sbi->s_bal_cX_hits[CR_POWER2_ALIGNED]));
3105 seq, "\t\tgroups_considered: %llu\n",
3107 &sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED]));
3108 seq_printf(seq, "\t\textents_scanned: %u\n",
3109 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_POWER2_ALIGNED]));
3110 seq_printf(seq, "\t\tuseless_loops: %llu\n",
3111 atomic64_read(&sbi->s_bal_cX_failed[CR_POWER2_ALIGNED]));
3112 seq_printf(seq, "\t\tbad_suggestions: %u\n",
3113 atomic_read(&sbi->s_bal_p2_aligned_bad_suggestions));
3115 /* CR_GOAL_LEN_FAST stats */
3116 seq_puts(seq, "\tcr_goal_fast_stats:\n");
3117 seq_printf(seq, "\t\thits: %llu\n",
3118 atomic64_read(&sbi->s_bal_cX_hits[CR_GOAL_LEN_FAST]));
3119 seq_printf(seq, "\t\tgroups_considered: %llu\n",
3121 &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_FAST]));
3122 seq_printf(seq, "\t\textents_scanned: %u\n",
3123 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_FAST]));
3124 seq_printf(seq, "\t\tuseless_loops: %llu\n",
3125 atomic64_read(&sbi->s_bal_cX_failed[CR_GOAL_LEN_FAST]));
3126 seq_printf(seq, "\t\tbad_suggestions: %u\n",
3127 atomic_read(&sbi->s_bal_goal_fast_bad_suggestions));
3129 /* CR_BEST_AVAIL_LEN stats */
3130 seq_puts(seq, "\tcr_best_avail_stats:\n");
3131 seq_printf(seq, "\t\thits: %llu\n",
3132 atomic64_read(&sbi->s_bal_cX_hits[CR_BEST_AVAIL_LEN]));
3134 seq, "\t\tgroups_considered: %llu\n",
3136 &sbi->s_bal_cX_groups_considered[CR_BEST_AVAIL_LEN]));
3137 seq_printf(seq, "\t\textents_scanned: %u\n",
3138 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_BEST_AVAIL_LEN]));
3139 seq_printf(seq, "\t\tuseless_loops: %llu\n",
3140 atomic64_read(&sbi->s_bal_cX_failed[CR_BEST_AVAIL_LEN]));
3141 seq_printf(seq, "\t\tbad_suggestions: %u\n",
3142 atomic_read(&sbi->s_bal_best_avail_bad_suggestions));
3144 /* CR_GOAL_LEN_SLOW stats */
3145 seq_puts(seq, "\tcr_goal_slow_stats:\n");
3146 seq_printf(seq, "\t\thits: %llu\n",
3147 atomic64_read(&sbi->s_bal_cX_hits[CR_GOAL_LEN_SLOW]));
3148 seq_printf(seq, "\t\tgroups_considered: %llu\n",
3150 &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_SLOW]));
3151 seq_printf(seq, "\t\textents_scanned: %u\n",
3152 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_SLOW]));
3153 seq_printf(seq, "\t\tuseless_loops: %llu\n",
3154 atomic64_read(&sbi->s_bal_cX_failed[CR_GOAL_LEN_SLOW]));
3156 /* CR_ANY_FREE stats */
3157 seq_puts(seq, "\tcr_any_free_stats:\n");
3158 seq_printf(seq, "\t\thits: %llu\n",
3159 atomic64_read(&sbi->s_bal_cX_hits[CR_ANY_FREE]));
3161 seq, "\t\tgroups_considered: %llu\n",
3162 atomic64_read(&sbi->s_bal_cX_groups_considered[CR_ANY_FREE]));
3163 seq_printf(seq, "\t\textents_scanned: %u\n",
3164 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_ANY_FREE]));
3165 seq_printf(seq, "\t\tuseless_loops: %llu\n",
3166 atomic64_read(&sbi->s_bal_cX_failed[CR_ANY_FREE]));
3169 seq_printf(seq, "\textents_scanned: %u\n",
3170 atomic_read(&sbi->s_bal_ex_scanned));
3171 seq_printf(seq, "\t\tgoal_hits: %u\n", atomic_read(&sbi->s_bal_goals));
3172 seq_printf(seq, "\t\tlen_goal_hits: %u\n",
3173 atomic_read(&sbi->s_bal_len_goals));
3174 seq_printf(seq, "\t\t2^n_hits: %u\n", atomic_read(&sbi->s_bal_2orders));
3175 seq_printf(seq, "\t\tbreaks: %u\n", atomic_read(&sbi->s_bal_breaks));
3176 seq_printf(seq, "\t\tlost: %u\n", atomic_read(&sbi->s_mb_lost_chunks));
3177 seq_printf(seq, "\tbuddies_generated: %u/%u\n",
3178 atomic_read(&sbi->s_mb_buddies_generated),
3179 ext4_get_groups_count(sb));
3180 seq_printf(seq, "\tbuddies_time_used: %llu\n",
3181 atomic64_read(&sbi->s_mb_generation_time));
3182 seq_printf(seq, "\tpreallocated: %u\n",
3183 atomic_read(&sbi->s_mb_preallocated));
3184 seq_printf(seq, "\tdiscarded: %u\n", atomic_read(&sbi->s_mb_discarded));
3188 static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos)
3189 __acquires(&EXT4_SB(sb)->s_mb_rb_lock)
3191 struct super_block *sb = pde_data(file_inode(seq->file));
3192 unsigned long position;
3194 if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb))
3196 position = *pos + 1;
3197 return (void *) ((unsigned long) position);
3200 static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos)
3202 struct super_block *sb = pde_data(file_inode(seq->file));
3203 unsigned long position;
3206 if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb))
3208 position = *pos + 1;
3209 return (void *) ((unsigned long) position);
3212 static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v)
3214 struct super_block *sb = pde_data(file_inode(seq->file));
3215 struct ext4_sb_info *sbi = EXT4_SB(sb);
3216 unsigned long position = ((unsigned long) v);
3217 struct ext4_group_info *grp;
3221 if (position >= MB_NUM_ORDERS(sb)) {
3222 position -= MB_NUM_ORDERS(sb);
3224 seq_puts(seq, "avg_fragment_size_lists:\n");
3227 read_lock(&sbi->s_mb_avg_fragment_size_locks[position]);
3228 list_for_each_entry(grp, &sbi->s_mb_avg_fragment_size[position],
3229 bb_avg_fragment_size_node)
3231 read_unlock(&sbi->s_mb_avg_fragment_size_locks[position]);
3232 seq_printf(seq, "\tlist_order_%u_groups: %u\n",
3233 (unsigned int)position, count);
3237 if (position == 0) {
3238 seq_printf(seq, "optimize_scan: %d\n",
3239 test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0);
3240 seq_puts(seq, "max_free_order_lists:\n");
3243 read_lock(&sbi->s_mb_largest_free_orders_locks[position]);
3244 list_for_each_entry(grp, &sbi->s_mb_largest_free_orders[position],
3245 bb_largest_free_order_node)
3247 read_unlock(&sbi->s_mb_largest_free_orders_locks[position]);
3248 seq_printf(seq, "\tlist_order_%u_groups: %u\n",
3249 (unsigned int)position, count);
3254 static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v)
3258 const struct seq_operations ext4_mb_seq_structs_summary_ops = {
3259 .start = ext4_mb_seq_structs_summary_start,
3260 .next = ext4_mb_seq_structs_summary_next,
3261 .stop = ext4_mb_seq_structs_summary_stop,
3262 .show = ext4_mb_seq_structs_summary_show,
3265 static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
3267 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3268 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
3275 * Allocate the top-level s_group_info array for the specified number
3278 int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
3280 struct ext4_sb_info *sbi = EXT4_SB(sb);
3282 struct ext4_group_info ***old_groupinfo, ***new_groupinfo;
3284 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
3285 EXT4_DESC_PER_BLOCK_BITS(sb);
3286 if (size <= sbi->s_group_info_size)
3289 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
3290 new_groupinfo = kvzalloc(size, GFP_KERNEL);
3291 if (!new_groupinfo) {
3292 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
3296 old_groupinfo = rcu_dereference(sbi->s_group_info);
3298 memcpy(new_groupinfo, old_groupinfo,
3299 sbi->s_group_info_size * sizeof(*sbi->s_group_info));
3301 rcu_assign_pointer(sbi->s_group_info, new_groupinfo);
3302 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
3304 ext4_kvfree_array_rcu(old_groupinfo);
3305 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
3306 sbi->s_group_info_size);
3310 /* Create and initialize ext4_group_info data for the given group. */
3311 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
3312 struct ext4_group_desc *desc)
3316 int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb);
3317 struct ext4_sb_info *sbi = EXT4_SB(sb);
3318 struct ext4_group_info **meta_group_info;
3319 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
3322 * First check if this group is the first of a reserved block.
3323 * If it's true, we have to allocate a new table of pointers
3324 * to ext4_group_info structures
3326 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3327 metalen = sizeof(*meta_group_info) <<
3328 EXT4_DESC_PER_BLOCK_BITS(sb);
3329 meta_group_info = kmalloc(metalen, GFP_NOFS);
3330 if (meta_group_info == NULL) {
3331 ext4_msg(sb, KERN_ERR, "can't allocate mem "
3332 "for a buddy group");
3336 rcu_dereference(sbi->s_group_info)[idx] = meta_group_info;
3340 meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx);
3341 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
3343 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
3344 if (meta_group_info[i] == NULL) {
3345 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
3346 goto exit_group_info;
3348 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
3349 &(meta_group_info[i]->bb_state));
3352 * initialize bb_free to be able to skip
3353 * empty groups without initialization
3355 if (ext4_has_group_desc_csum(sb) &&
3356 (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3357 meta_group_info[i]->bb_free =
3358 ext4_free_clusters_after_init(sb, group, desc);
3360 meta_group_info[i]->bb_free =
3361 ext4_free_group_clusters(sb, desc);
3364 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
3365 init_rwsem(&meta_group_info[i]->alloc_sem);
3366 meta_group_info[i]->bb_free_root = RB_ROOT;
3367 INIT_LIST_HEAD(&meta_group_info[i]->bb_largest_free_order_node);
3368 INIT_LIST_HEAD(&meta_group_info[i]->bb_avg_fragment_size_node);
3369 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
3370 meta_group_info[i]->bb_avg_fragment_size_order = -1; /* uninit */
3371 meta_group_info[i]->bb_group = group;
3373 mb_group_bb_bitmap_alloc(sb, meta_group_info[i], group);
3377 /* If a meta_group_info table has been allocated, release it now */
3378 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3379 struct ext4_group_info ***group_info;
3382 group_info = rcu_dereference(sbi->s_group_info);
3383 kfree(group_info[idx]);
3384 group_info[idx] = NULL;
3388 } /* ext4_mb_add_groupinfo */
3390 static int ext4_mb_init_backend(struct super_block *sb)
3392 ext4_group_t ngroups = ext4_get_groups_count(sb);
3394 struct ext4_sb_info *sbi = EXT4_SB(sb);
3396 struct ext4_group_desc *desc;
3397 struct ext4_group_info ***group_info;
3398 struct kmem_cache *cachep;
3400 err = ext4_mb_alloc_groupinfo(sb, ngroups);
3404 sbi->s_buddy_cache = new_inode(sb);
3405 if (sbi->s_buddy_cache == NULL) {
3406 ext4_msg(sb, KERN_ERR, "can't get new inode");
3409 /* To avoid potentially colliding with an valid on-disk inode number,
3410 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
3411 * not in the inode hash, so it should never be found by iget(), but
3412 * this will avoid confusion if it ever shows up during debugging. */
3413 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
3414 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
3415 for (i = 0; i < ngroups; i++) {
3417 desc = ext4_get_group_desc(sb, i, NULL);
3419 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
3422 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
3426 if (ext4_has_feature_flex_bg(sb)) {
3427 /* a single flex group is supposed to be read by a single IO.
3428 * 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is
3429 * unsigned integer, so the maximum shift is 32.
3431 if (sbi->s_es->s_log_groups_per_flex >= 32) {
3432 ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group");
3435 sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex,
3436 BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9));
3437 sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */
3439 sbi->s_mb_prefetch = 32;
3441 if (sbi->s_mb_prefetch > ext4_get_groups_count(sb))
3442 sbi->s_mb_prefetch = ext4_get_groups_count(sb);
3443 /* now many real IOs to prefetch within a single allocation at cr=0
3444 * given cr=0 is an CPU-related optimization we shouldn't try to
3445 * load too many groups, at some point we should start to use what
3446 * we've got in memory.
3447 * with an average random access time 5ms, it'd take a second to get
3448 * 200 groups (* N with flex_bg), so let's make this limit 4
3450 sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4;
3451 if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb))
3452 sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb);
3457 cachep = get_groupinfo_cache(sb->s_blocksize_bits);
3459 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
3462 kmem_cache_free(cachep, grp);
3464 i = sbi->s_group_info_size;
3466 group_info = rcu_dereference(sbi->s_group_info);
3468 kfree(group_info[i]);
3470 iput(sbi->s_buddy_cache);
3473 kvfree(rcu_dereference(sbi->s_group_info));
3478 static void ext4_groupinfo_destroy_slabs(void)
3482 for (i = 0; i < NR_GRPINFO_CACHES; i++) {
3483 kmem_cache_destroy(ext4_groupinfo_caches[i]);
3484 ext4_groupinfo_caches[i] = NULL;
3488 static int ext4_groupinfo_create_slab(size_t size)
3490 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
3492 int blocksize_bits = order_base_2(size);
3493 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3494 struct kmem_cache *cachep;
3496 if (cache_index >= NR_GRPINFO_CACHES)
3499 if (unlikely(cache_index < 0))
3502 mutex_lock(&ext4_grpinfo_slab_create_mutex);
3503 if (ext4_groupinfo_caches[cache_index]) {
3504 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
3505 return 0; /* Already created */
3508 slab_size = offsetof(struct ext4_group_info,
3509 bb_counters[blocksize_bits + 2]);
3511 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
3512 slab_size, 0, SLAB_RECLAIM_ACCOUNT,
3515 ext4_groupinfo_caches[cache_index] = cachep;
3517 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
3520 "EXT4-fs: no memory for groupinfo slab cache\n");
3527 static void ext4_discard_work(struct work_struct *work)
3529 struct ext4_sb_info *sbi = container_of(work,
3530 struct ext4_sb_info, s_discard_work);
3531 struct super_block *sb = sbi->s_sb;
3532 struct ext4_free_data *fd, *nfd;
3533 struct ext4_buddy e4b;
3534 LIST_HEAD(discard_list);
3535 ext4_group_t grp, load_grp;
3538 spin_lock(&sbi->s_md_lock);
3539 list_splice_init(&sbi->s_discard_list, &discard_list);
3540 spin_unlock(&sbi->s_md_lock);
3542 load_grp = UINT_MAX;
3543 list_for_each_entry_safe(fd, nfd, &discard_list, efd_list) {
3545 * If filesystem is umounting or no memory or suffering
3546 * from no space, give up the discard
3548 if ((sb->s_flags & SB_ACTIVE) && !err &&
3549 !atomic_read(&sbi->s_retry_alloc_pending)) {
3550 grp = fd->efd_group;
3551 if (grp != load_grp) {
3552 if (load_grp != UINT_MAX)
3553 ext4_mb_unload_buddy(&e4b);
3555 err = ext4_mb_load_buddy(sb, grp, &e4b);
3557 kmem_cache_free(ext4_free_data_cachep, fd);
3558 load_grp = UINT_MAX;
3565 ext4_lock_group(sb, grp);
3566 ext4_try_to_trim_range(sb, &e4b, fd->efd_start_cluster,
3567 fd->efd_start_cluster + fd->efd_count - 1, 1);
3568 ext4_unlock_group(sb, grp);
3570 kmem_cache_free(ext4_free_data_cachep, fd);
3573 if (load_grp != UINT_MAX)
3574 ext4_mb_unload_buddy(&e4b);
3577 int ext4_mb_init(struct super_block *sb)
3579 struct ext4_sb_info *sbi = EXT4_SB(sb);
3581 unsigned offset, offset_incr;
3585 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets);
3587 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
3588 if (sbi->s_mb_offsets == NULL) {
3593 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs);
3594 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
3595 if (sbi->s_mb_maxs == NULL) {
3600 ret = ext4_groupinfo_create_slab(sb->s_blocksize);
3604 /* order 0 is regular bitmap */
3605 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
3606 sbi->s_mb_offsets[0] = 0;
3610 offset_incr = 1 << (sb->s_blocksize_bits - 1);
3611 max = sb->s_blocksize << 2;
3613 sbi->s_mb_offsets[i] = offset;
3614 sbi->s_mb_maxs[i] = max;
3615 offset += offset_incr;
3616 offset_incr = offset_incr >> 1;
3619 } while (i < MB_NUM_ORDERS(sb));
3621 sbi->s_mb_avg_fragment_size =
3622 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head),
3624 if (!sbi->s_mb_avg_fragment_size) {
3628 sbi->s_mb_avg_fragment_size_locks =
3629 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t),
3631 if (!sbi->s_mb_avg_fragment_size_locks) {
3635 for (i = 0; i < MB_NUM_ORDERS(sb); i++) {
3636 INIT_LIST_HEAD(&sbi->s_mb_avg_fragment_size[i]);
3637 rwlock_init(&sbi->s_mb_avg_fragment_size_locks[i]);
3639 sbi->s_mb_largest_free_orders =
3640 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head),
3642 if (!sbi->s_mb_largest_free_orders) {
3646 sbi->s_mb_largest_free_orders_locks =
3647 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t),
3649 if (!sbi->s_mb_largest_free_orders_locks) {
3653 for (i = 0; i < MB_NUM_ORDERS(sb); i++) {
3654 INIT_LIST_HEAD(&sbi->s_mb_largest_free_orders[i]);
3655 rwlock_init(&sbi->s_mb_largest_free_orders_locks[i]);
3658 spin_lock_init(&sbi->s_md_lock);
3659 sbi->s_mb_free_pending = 0;
3660 INIT_LIST_HEAD(&sbi->s_freed_data_list[0]);
3661 INIT_LIST_HEAD(&sbi->s_freed_data_list[1]);
3662 INIT_LIST_HEAD(&sbi->s_discard_list);
3663 INIT_WORK(&sbi->s_discard_work, ext4_discard_work);
3664 atomic_set(&sbi->s_retry_alloc_pending, 0);
3666 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
3667 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
3668 sbi->s_mb_stats = MB_DEFAULT_STATS;
3669 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
3670 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
3671 sbi->s_mb_best_avail_max_trim_order = MB_DEFAULT_BEST_AVAIL_TRIM_ORDER;
3674 * The default group preallocation is 512, which for 4k block
3675 * sizes translates to 2 megabytes. However for bigalloc file
3676 * systems, this is probably too big (i.e, if the cluster size
3677 * is 1 megabyte, then group preallocation size becomes half a
3678 * gigabyte!). As a default, we will keep a two megabyte
3679 * group pralloc size for cluster sizes up to 64k, and after
3680 * that, we will force a minimum group preallocation size of
3681 * 32 clusters. This translates to 8 megs when the cluster
3682 * size is 256k, and 32 megs when the cluster size is 1 meg,
3683 * which seems reasonable as a default.
3685 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
3686 sbi->s_cluster_bits, 32);
3688 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
3689 * to the lowest multiple of s_stripe which is bigger than
3690 * the s_mb_group_prealloc as determined above. We want
3691 * the preallocation size to be an exact multiple of the
3692 * RAID stripe size so that preallocations don't fragment
3695 if (sbi->s_stripe > 1) {
3696 sbi->s_mb_group_prealloc = roundup(
3697 sbi->s_mb_group_prealloc, EXT4_B2C(sbi, sbi->s_stripe));
3700 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
3701 if (sbi->s_locality_groups == NULL) {
3705 for_each_possible_cpu(i) {
3706 struct ext4_locality_group *lg;
3707 lg = per_cpu_ptr(sbi->s_locality_groups, i);
3708 mutex_init(&lg->lg_mutex);
3709 for (j = 0; j < PREALLOC_TB_SIZE; j++)
3710 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
3711 spin_lock_init(&lg->lg_prealloc_lock);
3714 if (bdev_nonrot(sb->s_bdev))
3715 sbi->s_mb_max_linear_groups = 0;
3717 sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT;
3718 /* init file for buddy data */
3719 ret = ext4_mb_init_backend(sb);
3721 goto out_free_locality_groups;
3725 out_free_locality_groups:
3726 free_percpu(sbi->s_locality_groups);
3727 sbi->s_locality_groups = NULL;
3729 kfree(sbi->s_mb_avg_fragment_size);
3730 kfree(sbi->s_mb_avg_fragment_size_locks);
3731 kfree(sbi->s_mb_largest_free_orders);
3732 kfree(sbi->s_mb_largest_free_orders_locks);
3733 kfree(sbi->s_mb_offsets);
3734 sbi->s_mb_offsets = NULL;
3735 kfree(sbi->s_mb_maxs);
3736 sbi->s_mb_maxs = NULL;
3740 /* need to called with the ext4 group lock held */
3741 static int ext4_mb_cleanup_pa(struct ext4_group_info *grp)
3743 struct ext4_prealloc_space *pa;
3744 struct list_head *cur, *tmp;
3747 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
3748 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3749 list_del(&pa->pa_group_list);
3751 kmem_cache_free(ext4_pspace_cachep, pa);
3756 void ext4_mb_release(struct super_block *sb)
3758 ext4_group_t ngroups = ext4_get_groups_count(sb);
3760 int num_meta_group_infos;
3761 struct ext4_group_info *grinfo, ***group_info;
3762 struct ext4_sb_info *sbi = EXT4_SB(sb);
3763 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
3766 if (test_opt(sb, DISCARD)) {
3768 * wait the discard work to drain all of ext4_free_data
3770 flush_work(&sbi->s_discard_work);
3771 WARN_ON_ONCE(!list_empty(&sbi->s_discard_list));
3774 if (sbi->s_group_info) {
3775 for (i = 0; i < ngroups; i++) {
3777 grinfo = ext4_get_group_info(sb, i);
3780 mb_group_bb_bitmap_free(grinfo);
3781 ext4_lock_group(sb, i);
3782 count = ext4_mb_cleanup_pa(grinfo);
3784 mb_debug(sb, "mballoc: %d PAs left\n",
3786 ext4_unlock_group(sb, i);
3787 kmem_cache_free(cachep, grinfo);
3789 num_meta_group_infos = (ngroups +
3790 EXT4_DESC_PER_BLOCK(sb) - 1) >>
3791 EXT4_DESC_PER_BLOCK_BITS(sb);
3793 group_info = rcu_dereference(sbi->s_group_info);
3794 for (i = 0; i < num_meta_group_infos; i++)
3795 kfree(group_info[i]);
3799 kfree(sbi->s_mb_avg_fragment_size);
3800 kfree(sbi->s_mb_avg_fragment_size_locks);
3801 kfree(sbi->s_mb_largest_free_orders);
3802 kfree(sbi->s_mb_largest_free_orders_locks);
3803 kfree(sbi->s_mb_offsets);
3804 kfree(sbi->s_mb_maxs);
3805 iput(sbi->s_buddy_cache);
3806 if (sbi->s_mb_stats) {
3807 ext4_msg(sb, KERN_INFO,
3808 "mballoc: %u blocks %u reqs (%u success)",
3809 atomic_read(&sbi->s_bal_allocated),
3810 atomic_read(&sbi->s_bal_reqs),
3811 atomic_read(&sbi->s_bal_success));
3812 ext4_msg(sb, KERN_INFO,
3813 "mballoc: %u extents scanned, %u groups scanned, %u goal hits, "
3814 "%u 2^N hits, %u breaks, %u lost",
3815 atomic_read(&sbi->s_bal_ex_scanned),
3816 atomic_read(&sbi->s_bal_groups_scanned),
3817 atomic_read(&sbi->s_bal_goals),
3818 atomic_read(&sbi->s_bal_2orders),
3819 atomic_read(&sbi->s_bal_breaks),
3820 atomic_read(&sbi->s_mb_lost_chunks));
3821 ext4_msg(sb, KERN_INFO,
3822 "mballoc: %u generated and it took %llu",
3823 atomic_read(&sbi->s_mb_buddies_generated),
3824 atomic64_read(&sbi->s_mb_generation_time));
3825 ext4_msg(sb, KERN_INFO,
3826 "mballoc: %u preallocated, %u discarded",
3827 atomic_read(&sbi->s_mb_preallocated),
3828 atomic_read(&sbi->s_mb_discarded));
3831 free_percpu(sbi->s_locality_groups);
3834 static inline int ext4_issue_discard(struct super_block *sb,
3835 ext4_group_t block_group, ext4_grpblk_t cluster, int count)
3837 ext4_fsblk_t discard_block;
3839 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
3840 ext4_group_first_block_no(sb, block_group));
3841 count = EXT4_C2B(EXT4_SB(sb), count);
3842 trace_ext4_discard_blocks(sb,
3843 (unsigned long long) discard_block, count);
3845 return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
3848 static void ext4_free_data_in_buddy(struct super_block *sb,
3849 struct ext4_free_data *entry)
3851 struct ext4_buddy e4b;
3852 struct ext4_group_info *db;
3855 mb_debug(sb, "gonna free %u blocks in group %u (0x%p):",
3856 entry->efd_count, entry->efd_group, entry);
3858 err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
3859 /* we expect to find existing buddy because it's pinned */
3862 spin_lock(&EXT4_SB(sb)->s_md_lock);
3863 EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
3864 spin_unlock(&EXT4_SB(sb)->s_md_lock);
3867 /* there are blocks to put in buddy to make them really free */
3868 count += entry->efd_count;
3869 ext4_lock_group(sb, entry->efd_group);
3870 /* Take it out of per group rb tree */
3871 rb_erase(&entry->efd_node, &(db->bb_free_root));
3872 mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count);
3875 * Clear the trimmed flag for the group so that the next
3876 * ext4_trim_fs can trim it.
3877 * If the volume is mounted with -o discard, online discard
3878 * is supported and the free blocks will be trimmed online.
3880 if (!test_opt(sb, DISCARD))
3881 EXT4_MB_GRP_CLEAR_TRIMMED(db);
3883 if (!db->bb_free_root.rb_node) {
3884 /* No more items in the per group rb tree
3885 * balance refcounts from ext4_mb_free_metadata()
3887 put_page(e4b.bd_buddy_page);
3888 put_page(e4b.bd_bitmap_page);
3890 ext4_unlock_group(sb, entry->efd_group);
3891 ext4_mb_unload_buddy(&e4b);
3893 mb_debug(sb, "freed %d blocks in 1 structures\n", count);
3897 * This function is called by the jbd2 layer once the commit has finished,
3898 * so we know we can free the blocks that were released with that commit.
3900 void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
3902 struct ext4_sb_info *sbi = EXT4_SB(sb);
3903 struct ext4_free_data *entry, *tmp;
3904 LIST_HEAD(freed_data_list);
3905 struct list_head *s_freed_head = &sbi->s_freed_data_list[commit_tid & 1];
3908 list_replace_init(s_freed_head, &freed_data_list);
3910 list_for_each_entry(entry, &freed_data_list, efd_list)
3911 ext4_free_data_in_buddy(sb, entry);
3913 if (test_opt(sb, DISCARD)) {
3914 spin_lock(&sbi->s_md_lock);
3915 wake = list_empty(&sbi->s_discard_list);
3916 list_splice_tail(&freed_data_list, &sbi->s_discard_list);
3917 spin_unlock(&sbi->s_md_lock);
3919 queue_work(system_unbound_wq, &sbi->s_discard_work);
3921 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
3922 kmem_cache_free(ext4_free_data_cachep, entry);
3926 int __init ext4_init_mballoc(void)
3928 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
3929 SLAB_RECLAIM_ACCOUNT);
3930 if (ext4_pspace_cachep == NULL)
3933 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
3934 SLAB_RECLAIM_ACCOUNT);
3935 if (ext4_ac_cachep == NULL)
3938 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
3939 SLAB_RECLAIM_ACCOUNT);
3940 if (ext4_free_data_cachep == NULL)
3946 kmem_cache_destroy(ext4_ac_cachep);
3948 kmem_cache_destroy(ext4_pspace_cachep);
3953 void ext4_exit_mballoc(void)
3956 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
3957 * before destroying the slab cache.
3960 kmem_cache_destroy(ext4_pspace_cachep);
3961 kmem_cache_destroy(ext4_ac_cachep);
3962 kmem_cache_destroy(ext4_free_data_cachep);
3963 ext4_groupinfo_destroy_slabs();
3966 #define EXT4_MB_BITMAP_MARKED_CHECK 0x0001
3967 #define EXT4_MB_SYNC_UPDATE 0x0002
3969 ext4_mb_mark_context(handle_t *handle, struct super_block *sb, bool state,
3970 ext4_group_t group, ext4_grpblk_t blkoff,
3971 ext4_grpblk_t len, int flags, ext4_grpblk_t *ret_changed)
3973 struct ext4_sb_info *sbi = EXT4_SB(sb);
3974 struct buffer_head *bitmap_bh = NULL;
3975 struct ext4_group_desc *gdp;
3976 struct buffer_head *gdp_bh;
3978 unsigned int i, already, changed = len;
3980 KUNIT_STATIC_STUB_REDIRECT(ext4_mb_mark_context,
3981 handle, sb, state, group, blkoff, len,
3982 flags, ret_changed);
3986 bitmap_bh = ext4_read_block_bitmap(sb, group);
3987 if (IS_ERR(bitmap_bh))
3988 return PTR_ERR(bitmap_bh);
3991 BUFFER_TRACE(bitmap_bh, "getting write access");
3992 err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
3999 gdp = ext4_get_group_desc(sb, group, &gdp_bh);
4004 BUFFER_TRACE(gdp_bh, "get_write_access");
4005 err = ext4_journal_get_write_access(handle, sb, gdp_bh,
4011 ext4_lock_group(sb, group);
4012 if (ext4_has_group_desc_csum(sb) &&
4013 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
4014 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
4015 ext4_free_group_clusters_set(sb, gdp,
4016 ext4_free_clusters_after_init(sb, group, gdp));
4019 if (flags & EXT4_MB_BITMAP_MARKED_CHECK) {
4021 for (i = 0; i < len; i++)
4022 if (mb_test_bit(blkoff + i, bitmap_bh->b_data) ==
4025 changed = len - already;
4029 mb_set_bits(bitmap_bh->b_data, blkoff, len);
4030 ext4_free_group_clusters_set(sb, gdp,
4031 ext4_free_group_clusters(sb, gdp) - changed);
4033 mb_clear_bits(bitmap_bh->b_data, blkoff, len);
4034 ext4_free_group_clusters_set(sb, gdp,
4035 ext4_free_group_clusters(sb, gdp) + changed);
4038 ext4_block_bitmap_csum_set(sb, gdp, bitmap_bh);
4039 ext4_group_desc_csum_set(sb, group, gdp);
4040 ext4_unlock_group(sb, group);
4042 *ret_changed = changed;
4044 if (sbi->s_log_groups_per_flex) {
4045 ext4_group_t flex_group = ext4_flex_group(sbi, group);
4046 struct flex_groups *fg = sbi_array_rcu_deref(sbi,
4047 s_flex_groups, flex_group);
4050 atomic64_sub(changed, &fg->free_clusters);
4052 atomic64_add(changed, &fg->free_clusters);
4055 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
4058 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
4062 if (flags & EXT4_MB_SYNC_UPDATE) {
4063 sync_dirty_buffer(bitmap_bh);
4064 sync_dirty_buffer(gdp_bh);
4073 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
4074 * Returns 0 if success or error code
4076 static noinline_for_stack int
4077 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
4078 handle_t *handle, unsigned int reserv_clstrs)
4080 struct ext4_group_desc *gdp;
4081 struct ext4_sb_info *sbi;
4082 struct super_block *sb;
4086 ext4_grpblk_t changed;
4088 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
4089 BUG_ON(ac->ac_b_ex.fe_len <= 0);
4094 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, NULL);
4097 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
4098 ext4_free_group_clusters(sb, gdp));
4100 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4101 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4102 if (!ext4_inode_block_valid(ac->ac_inode, block, len)) {
4103 ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
4104 "fs metadata", block, block+len);
4105 /* File system mounted not to panic on error
4106 * Fix the bitmap and return EFSCORRUPTED
4107 * We leak some of the blocks here.
4109 err = ext4_mb_mark_context(handle, sb, true,
4110 ac->ac_b_ex.fe_group,
4111 ac->ac_b_ex.fe_start,
4115 err = -EFSCORRUPTED;
4119 #ifdef AGGRESSIVE_CHECK
4120 flags |= EXT4_MB_BITMAP_MARKED_CHECK;
4122 err = ext4_mb_mark_context(handle, sb, true, ac->ac_b_ex.fe_group,
4123 ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len,
4126 if (err && changed == 0)
4129 #ifdef AGGRESSIVE_CHECK
4130 BUG_ON(changed != ac->ac_b_ex.fe_len);
4132 percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
4134 * Now reduce the dirty block count also. Should not go negative
4136 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
4137 /* release all the reserved blocks if non delalloc */
4138 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
4145 * Idempotent helper for Ext4 fast commit replay path to set the state of
4146 * blocks in bitmaps and update counters.
4148 void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
4149 int len, bool state)
4151 struct ext4_sb_info *sbi = EXT4_SB(sb);
4153 ext4_grpblk_t blkoff;
4155 unsigned int clen, thisgrp_len;
4158 ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
4161 * Check to see if we are freeing blocks across a group
4163 * In case of flex_bg, this can happen that (block, len) may
4164 * span across more than one group. In that case we need to
4165 * get the corresponding group metadata to work with.
4166 * For this we have goto again loop.
4168 thisgrp_len = min_t(unsigned int, (unsigned int)len,
4169 EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
4170 clen = EXT4_NUM_B2C(sbi, thisgrp_len);
4172 if (!ext4_sb_block_valid(sb, NULL, block, thisgrp_len)) {
4173 ext4_error(sb, "Marking blocks in system zone - "
4174 "Block = %llu, len = %u",
4175 block, thisgrp_len);
4179 err = ext4_mb_mark_context(NULL, sb, state,
4180 group, blkoff, clen,
4181 EXT4_MB_BITMAP_MARKED_CHECK |
4182 EXT4_MB_SYNC_UPDATE,
4187 block += thisgrp_len;
4194 * here we normalize request for locality group
4195 * Group request are normalized to s_mb_group_prealloc, which goes to
4196 * s_strip if we set the same via mount option.
4197 * s_mb_group_prealloc can be configured via
4198 * /sys/fs/ext4/<partition>/mb_group_prealloc
4200 * XXX: should we try to preallocate more than the group has now?
4202 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
4204 struct super_block *sb = ac->ac_sb;
4205 struct ext4_locality_group *lg = ac->ac_lg;
4208 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
4209 mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len);
4213 * This function returns the next element to look at during inode
4214 * PA rbtree walk. We assume that we have held the inode PA rbtree lock
4215 * (ei->i_prealloc_lock)
4217 * new_start The start of the range we want to compare
4218 * cur_start The existing start that we are comparing against
4219 * node The node of the rb_tree
4221 static inline struct rb_node*
4222 ext4_mb_pa_rb_next_iter(ext4_lblk_t new_start, ext4_lblk_t cur_start, struct rb_node *node)
4224 if (new_start < cur_start)
4225 return node->rb_left;
4227 return node->rb_right;
4231 ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac,
4232 ext4_lblk_t start, loff_t end)
4234 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4235 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4236 struct ext4_prealloc_space *tmp_pa;
4237 ext4_lblk_t tmp_pa_start;
4239 struct rb_node *iter;
4241 read_lock(&ei->i_prealloc_lock);
4242 for (iter = ei->i_prealloc_node.rb_node; iter;
4243 iter = ext4_mb_pa_rb_next_iter(start, tmp_pa_start, iter)) {
4244 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4245 pa_node.inode_node);
4246 tmp_pa_start = tmp_pa->pa_lstart;
4247 tmp_pa_end = pa_logical_end(sbi, tmp_pa);
4249 spin_lock(&tmp_pa->pa_lock);
4250 if (tmp_pa->pa_deleted == 0)
4251 BUG_ON(!(start >= tmp_pa_end || end <= tmp_pa_start));
4252 spin_unlock(&tmp_pa->pa_lock);
4254 read_unlock(&ei->i_prealloc_lock);
4258 * Given an allocation context "ac" and a range "start", "end", check
4259 * and adjust boundaries if the range overlaps with any of the existing
4260 * preallocatoins stored in the corresponding inode of the allocation context.
4263 * ac allocation context
4264 * start start of the new range
4265 * end end of the new range
4268 ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac,
4269 ext4_lblk_t *start, loff_t *end)
4271 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4272 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4273 struct ext4_prealloc_space *tmp_pa = NULL, *left_pa = NULL, *right_pa = NULL;
4274 struct rb_node *iter;
4275 ext4_lblk_t new_start, tmp_pa_start, right_pa_start = -1;
4276 loff_t new_end, tmp_pa_end, left_pa_end = -1;
4282 * Adjust the normalized range so that it doesn't overlap with any
4283 * existing preallocated blocks(PAs). Make sure to hold the rbtree lock
4284 * so it doesn't change underneath us.
4286 read_lock(&ei->i_prealloc_lock);
4288 /* Step 1: find any one immediate neighboring PA of the normalized range */
4289 for (iter = ei->i_prealloc_node.rb_node; iter;
4290 iter = ext4_mb_pa_rb_next_iter(ac->ac_o_ex.fe_logical,
4291 tmp_pa_start, iter)) {
4292 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4293 pa_node.inode_node);
4294 tmp_pa_start = tmp_pa->pa_lstart;
4295 tmp_pa_end = pa_logical_end(sbi, tmp_pa);
4297 /* PA must not overlap original request */
4298 spin_lock(&tmp_pa->pa_lock);
4299 if (tmp_pa->pa_deleted == 0)
4300 BUG_ON(!(ac->ac_o_ex.fe_logical >= tmp_pa_end ||
4301 ac->ac_o_ex.fe_logical < tmp_pa_start));
4302 spin_unlock(&tmp_pa->pa_lock);
4306 * Step 2: check if the found PA is left or right neighbor and
4307 * get the other neighbor
4310 if (tmp_pa->pa_lstart < ac->ac_o_ex.fe_logical) {
4311 struct rb_node *tmp;
4314 tmp = rb_next(&left_pa->pa_node.inode_node);
4316 right_pa = rb_entry(tmp,
4317 struct ext4_prealloc_space,
4318 pa_node.inode_node);
4321 struct rb_node *tmp;
4324 tmp = rb_prev(&right_pa->pa_node.inode_node);
4326 left_pa = rb_entry(tmp,
4327 struct ext4_prealloc_space,
4328 pa_node.inode_node);
4333 /* Step 3: get the non deleted neighbors */
4335 for (iter = &left_pa->pa_node.inode_node;;
4336 iter = rb_prev(iter)) {
4342 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4343 pa_node.inode_node);
4345 spin_lock(&tmp_pa->pa_lock);
4346 if (tmp_pa->pa_deleted == 0) {
4347 spin_unlock(&tmp_pa->pa_lock);
4350 spin_unlock(&tmp_pa->pa_lock);
4355 for (iter = &right_pa->pa_node.inode_node;;
4356 iter = rb_next(iter)) {
4362 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4363 pa_node.inode_node);
4365 spin_lock(&tmp_pa->pa_lock);
4366 if (tmp_pa->pa_deleted == 0) {
4367 spin_unlock(&tmp_pa->pa_lock);
4370 spin_unlock(&tmp_pa->pa_lock);
4375 left_pa_end = pa_logical_end(sbi, left_pa);
4376 BUG_ON(left_pa_end > ac->ac_o_ex.fe_logical);
4380 right_pa_start = right_pa->pa_lstart;
4381 BUG_ON(right_pa_start <= ac->ac_o_ex.fe_logical);
4384 /* Step 4: trim our normalized range to not overlap with the neighbors */
4386 if (left_pa_end > new_start)
4387 new_start = left_pa_end;
4391 if (right_pa_start < new_end)
4392 new_end = right_pa_start;
4394 read_unlock(&ei->i_prealloc_lock);
4396 /* XXX: extra loop to check we really don't overlap preallocations */
4397 ext4_mb_pa_assert_overlap(ac, new_start, new_end);
4404 * Normalization means making request better in terms of
4405 * size and alignment
4407 static noinline_for_stack void
4408 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
4409 struct ext4_allocation_request *ar)
4411 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4412 struct ext4_super_block *es = sbi->s_es;
4414 loff_t size, start_off, end;
4415 loff_t orig_size __maybe_unused;
4418 /* do normalize only data requests, metadata requests
4419 do not need preallocation */
4420 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4423 /* sometime caller may want exact blocks */
4424 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4427 /* caller may indicate that preallocation isn't
4428 * required (it's a tail, for example) */
4429 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
4432 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
4433 ext4_mb_normalize_group_request(ac);
4437 bsbits = ac->ac_sb->s_blocksize_bits;
4439 /* first, let's learn actual file size
4440 * given current request is allocated */
4441 size = extent_logical_end(sbi, &ac->ac_o_ex);
4442 size = size << bsbits;
4443 if (size < i_size_read(ac->ac_inode))
4444 size = i_size_read(ac->ac_inode);
4447 /* max size of free chunks */
4450 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
4451 (req <= (size) || max <= (chunk_size))
4453 /* first, try to predict filesize */
4454 /* XXX: should this table be tunable? */
4456 if (size <= 16 * 1024) {
4458 } else if (size <= 32 * 1024) {
4460 } else if (size <= 64 * 1024) {
4462 } else if (size <= 128 * 1024) {
4464 } else if (size <= 256 * 1024) {
4466 } else if (size <= 512 * 1024) {
4468 } else if (size <= 1024 * 1024) {
4470 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
4471 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4472 (21 - bsbits)) << 21;
4473 size = 2 * 1024 * 1024;
4474 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
4475 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4476 (22 - bsbits)) << 22;
4477 size = 4 * 1024 * 1024;
4478 } else if (NRL_CHECK_SIZE(EXT4_C2B(sbi, ac->ac_o_ex.fe_len),
4479 (8<<20)>>bsbits, max, 8 * 1024)) {
4480 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4481 (23 - bsbits)) << 23;
4482 size = 8 * 1024 * 1024;
4484 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
4485 size = (loff_t) EXT4_C2B(sbi,
4486 ac->ac_o_ex.fe_len) << bsbits;
4488 size = size >> bsbits;
4489 start = start_off >> bsbits;
4492 * For tiny groups (smaller than 8MB) the chosen allocation
4493 * alignment may be larger than group size. Make sure the
4494 * alignment does not move allocation to a different group which
4495 * makes mballoc fail assertions later.
4497 start = max(start, rounddown(ac->ac_o_ex.fe_logical,
4498 (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
4500 /* avoid unnecessary preallocation that may trigger assertions */
4501 if (start + size > EXT_MAX_BLOCKS)
4502 size = EXT_MAX_BLOCKS - start;
4504 /* don't cover already allocated blocks in selected range */
4505 if (ar->pleft && start <= ar->lleft) {
4506 size -= ar->lleft + 1 - start;
4507 start = ar->lleft + 1;
4509 if (ar->pright && start + size - 1 >= ar->lright)
4510 size -= start + size - ar->lright;
4513 * Trim allocation request for filesystems with artificially small
4516 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
4517 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
4521 ext4_mb_pa_adjust_overlap(ac, &start, &end);
4526 * In this function "start" and "size" are normalized for better
4527 * alignment and length such that we could preallocate more blocks.
4528 * This normalization is done such that original request of
4529 * ac->ac_o_ex.fe_logical & fe_len should always lie within "start" and
4530 * "size" boundaries.
4531 * (Note fe_len can be relaxed since FS block allocation API does not
4532 * provide gurantee on number of contiguous blocks allocation since that
4533 * depends upon free space left, etc).
4534 * In case of inode pa, later we use the allocated blocks
4535 * [pa_pstart + fe_logical - pa_lstart, fe_len/size] from the preallocated
4536 * range of goal/best blocks [start, size] to put it at the
4537 * ac_o_ex.fe_logical extent of this inode.
4538 * (See ext4_mb_use_inode_pa() for more details)
4540 if (start + size <= ac->ac_o_ex.fe_logical ||
4541 start > ac->ac_o_ex.fe_logical) {
4542 ext4_msg(ac->ac_sb, KERN_ERR,
4543 "start %lu, size %lu, fe_logical %lu",
4544 (unsigned long) start, (unsigned long) size,
4545 (unsigned long) ac->ac_o_ex.fe_logical);
4548 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
4550 /* now prepare goal request */
4552 /* XXX: is it better to align blocks WRT to logical
4553 * placement or satisfy big request as is */
4554 ac->ac_g_ex.fe_logical = start;
4555 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
4556 ac->ac_orig_goal_len = ac->ac_g_ex.fe_len;
4558 /* define goal start in order to merge */
4559 if (ar->pright && (ar->lright == (start + size)) &&
4560 ar->pright >= size &&
4561 ar->pright - size >= le32_to_cpu(es->s_first_data_block)) {
4562 /* merge to the right */
4563 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
4564 &ac->ac_g_ex.fe_group,
4565 &ac->ac_g_ex.fe_start);
4566 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4568 if (ar->pleft && (ar->lleft + 1 == start) &&
4569 ar->pleft + 1 < ext4_blocks_count(es)) {
4570 /* merge to the left */
4571 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
4572 &ac->ac_g_ex.fe_group,
4573 &ac->ac_g_ex.fe_start);
4574 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4577 mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size,
4581 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
4583 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4585 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) {
4586 atomic_inc(&sbi->s_bal_reqs);
4587 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
4588 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
4589 atomic_inc(&sbi->s_bal_success);
4591 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
4592 for (int i=0; i<EXT4_MB_NUM_CRS; i++) {
4593 atomic_add(ac->ac_cX_found[i], &sbi->s_bal_cX_ex_scanned[i]);
4596 atomic_add(ac->ac_groups_scanned, &sbi->s_bal_groups_scanned);
4597 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
4598 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
4599 atomic_inc(&sbi->s_bal_goals);
4600 /* did we allocate as much as normalizer originally wanted? */
4601 if (ac->ac_f_ex.fe_len == ac->ac_orig_goal_len)
4602 atomic_inc(&sbi->s_bal_len_goals);
4604 if (ac->ac_found > sbi->s_mb_max_to_scan)
4605 atomic_inc(&sbi->s_bal_breaks);
4608 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
4609 trace_ext4_mballoc_alloc(ac);
4611 trace_ext4_mballoc_prealloc(ac);
4615 * Called on failure; free up any blocks from the inode PA for this
4616 * context. We don't need this for MB_GROUP_PA because we only change
4617 * pa_free in ext4_mb_release_context(), but on failure, we've already
4618 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
4620 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
4622 struct ext4_prealloc_space *pa = ac->ac_pa;
4623 struct ext4_buddy e4b;
4627 if (ac->ac_f_ex.fe_len == 0)
4629 err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
4630 if (WARN_RATELIMIT(err,
4631 "ext4: mb_load_buddy failed (%d)", err))
4633 * This should never happen since we pin the
4634 * pages in the ext4_allocation_context so
4635 * ext4_mb_load_buddy() should never fail.
4638 ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
4639 mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
4640 ac->ac_f_ex.fe_len);
4641 ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
4642 ext4_mb_unload_buddy(&e4b);
4645 if (pa->pa_type == MB_INODE_PA) {
4646 spin_lock(&pa->pa_lock);
4647 pa->pa_free += ac->ac_b_ex.fe_len;
4648 spin_unlock(&pa->pa_lock);
4653 * use blocks preallocated to inode
4655 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
4656 struct ext4_prealloc_space *pa)
4658 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4663 /* found preallocated blocks, use them */
4664 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
4665 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
4666 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
4667 len = EXT4_NUM_B2C(sbi, end - start);
4668 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
4669 &ac->ac_b_ex.fe_start);
4670 ac->ac_b_ex.fe_len = len;
4671 ac->ac_status = AC_STATUS_FOUND;
4674 BUG_ON(start < pa->pa_pstart);
4675 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
4676 BUG_ON(pa->pa_free < len);
4677 BUG_ON(ac->ac_b_ex.fe_len <= 0);
4680 mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa);
4684 * use blocks preallocated to locality group
4686 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
4687 struct ext4_prealloc_space *pa)
4689 unsigned int len = ac->ac_o_ex.fe_len;
4691 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
4692 &ac->ac_b_ex.fe_group,
4693 &ac->ac_b_ex.fe_start);
4694 ac->ac_b_ex.fe_len = len;
4695 ac->ac_status = AC_STATUS_FOUND;
4698 /* we don't correct pa_pstart or pa_len here to avoid
4699 * possible race when the group is being loaded concurrently
4700 * instead we correct pa later, after blocks are marked
4701 * in on-disk bitmap -- see ext4_mb_release_context()
4702 * Other CPUs are prevented from allocating from this pa by lg_mutex
4704 mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n",
4705 pa->pa_lstart, len, pa);
4709 * Return the prealloc space that have minimal distance
4710 * from the goal block. @cpa is the prealloc
4711 * space that is having currently known minimal distance
4712 * from the goal block.
4714 static struct ext4_prealloc_space *
4715 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
4716 struct ext4_prealloc_space *pa,
4717 struct ext4_prealloc_space *cpa)
4719 ext4_fsblk_t cur_distance, new_distance;
4722 atomic_inc(&pa->pa_count);
4725 cur_distance = abs(goal_block - cpa->pa_pstart);
4726 new_distance = abs(goal_block - pa->pa_pstart);
4728 if (cur_distance <= new_distance)
4731 /* drop the previous reference */
4732 atomic_dec(&cpa->pa_count);
4733 atomic_inc(&pa->pa_count);
4738 * check if found pa meets EXT4_MB_HINT_GOAL_ONLY
4741 ext4_mb_pa_goal_check(struct ext4_allocation_context *ac,
4742 struct ext4_prealloc_space *pa)
4744 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4747 if (likely(!(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)))
4751 * If EXT4_MB_HINT_GOAL_ONLY is set, ac_g_ex will not be adjusted
4752 * in ext4_mb_normalize_request and will keep same with ac_o_ex
4753 * from ext4_mb_initialize_context. Choose ac_g_ex here to keep
4754 * consistent with ext4_mb_find_by_goal.
4756 start = pa->pa_pstart +
4757 (ac->ac_g_ex.fe_logical - pa->pa_lstart);
4758 if (ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex) != start)
4761 if (ac->ac_g_ex.fe_len > pa->pa_len -
4762 EXT4_B2C(sbi, ac->ac_g_ex.fe_logical - pa->pa_lstart))
4769 * search goal blocks in preallocated space
4771 static noinline_for_stack bool
4772 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
4774 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4776 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4777 struct ext4_locality_group *lg;
4778 struct ext4_prealloc_space *tmp_pa = NULL, *cpa = NULL;
4779 struct rb_node *iter;
4780 ext4_fsblk_t goal_block;
4782 /* only data can be preallocated */
4783 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4787 * first, try per-file preallocation by searching the inode pa rbtree.
4789 * Here, we can't do a direct traversal of the tree because
4790 * ext4_mb_discard_group_preallocation() can paralelly mark the pa
4791 * deleted and that can cause direct traversal to skip some entries.
4793 read_lock(&ei->i_prealloc_lock);
4795 if (RB_EMPTY_ROOT(&ei->i_prealloc_node)) {
4800 * Step 1: Find a pa with logical start immediately adjacent to the
4801 * original logical start. This could be on the left or right.
4803 * (tmp_pa->pa_lstart never changes so we can skip locking for it).
4805 for (iter = ei->i_prealloc_node.rb_node; iter;
4806 iter = ext4_mb_pa_rb_next_iter(ac->ac_o_ex.fe_logical,
4807 tmp_pa->pa_lstart, iter)) {
4808 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4809 pa_node.inode_node);
4813 * Step 2: The adjacent pa might be to the right of logical start, find
4814 * the left adjacent pa. After this step we'd have a valid tmp_pa whose
4815 * logical start is towards the left of original request's logical start
4817 if (tmp_pa->pa_lstart > ac->ac_o_ex.fe_logical) {
4818 struct rb_node *tmp;
4819 tmp = rb_prev(&tmp_pa->pa_node.inode_node);
4822 tmp_pa = rb_entry(tmp, struct ext4_prealloc_space,
4823 pa_node.inode_node);
4826 * If there is no adjacent pa to the left then finding
4827 * an overlapping pa is not possible hence stop searching
4834 BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical));
4837 * Step 3: If the left adjacent pa is deleted, keep moving left to find
4838 * the first non deleted adjacent pa. After this step we should have a
4839 * valid tmp_pa which is guaranteed to be non deleted.
4841 for (iter = &tmp_pa->pa_node.inode_node;; iter = rb_prev(iter)) {
4844 * no non deleted left adjacent pa, so stop searching
4849 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4850 pa_node.inode_node);
4851 spin_lock(&tmp_pa->pa_lock);
4852 if (tmp_pa->pa_deleted == 0) {
4854 * We will keep holding the pa_lock from
4855 * this point on because we don't want group discard
4856 * to delete this pa underneath us. Since group
4857 * discard is anyways an ENOSPC operation it
4858 * should be okay for it to wait a few more cycles.
4862 spin_unlock(&tmp_pa->pa_lock);
4866 BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical));
4867 BUG_ON(tmp_pa->pa_deleted == 1);
4870 * Step 4: We now have the non deleted left adjacent pa. Only this
4871 * pa can possibly satisfy the request hence check if it overlaps
4872 * original logical start and stop searching if it doesn't.
4874 if (ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, tmp_pa)) {
4875 spin_unlock(&tmp_pa->pa_lock);
4879 /* non-extent files can't have physical blocks past 2^32 */
4880 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) &&
4881 (tmp_pa->pa_pstart + EXT4_C2B(sbi, tmp_pa->pa_len) >
4882 EXT4_MAX_BLOCK_FILE_PHYS)) {
4884 * Since PAs don't overlap, we won't find any other PA to
4887 spin_unlock(&tmp_pa->pa_lock);
4891 if (tmp_pa->pa_free && likely(ext4_mb_pa_goal_check(ac, tmp_pa))) {
4892 atomic_inc(&tmp_pa->pa_count);
4893 ext4_mb_use_inode_pa(ac, tmp_pa);
4894 spin_unlock(&tmp_pa->pa_lock);
4895 read_unlock(&ei->i_prealloc_lock);
4899 * We found a valid overlapping pa but couldn't use it because
4900 * it had no free blocks. This should ideally never happen
4903 * 1. When a new inode pa is added to rbtree it must have
4904 * pa_free > 0 since otherwise we won't actually need
4907 * 2. An inode pa that is in the rbtree can only have it's
4908 * pa_free become zero when another thread calls:
4909 * ext4_mb_new_blocks
4910 * ext4_mb_use_preallocated
4911 * ext4_mb_use_inode_pa
4913 * 3. Further, after the above calls make pa_free == 0, we will
4914 * immediately remove it from the rbtree in:
4915 * ext4_mb_new_blocks
4916 * ext4_mb_release_context
4919 * 4. Since the pa_free becoming 0 and pa_free getting removed
4920 * from tree both happen in ext4_mb_new_blocks, which is always
4921 * called with i_data_sem held for data allocations, we can be
4922 * sure that another process will never see a pa in rbtree with
4925 WARN_ON_ONCE(tmp_pa->pa_free == 0);
4927 spin_unlock(&tmp_pa->pa_lock);
4929 read_unlock(&ei->i_prealloc_lock);
4931 /* can we use group allocation? */
4932 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
4935 /* inode may have no locality group for some reason */
4939 order = fls(ac->ac_o_ex.fe_len) - 1;
4940 if (order > PREALLOC_TB_SIZE - 1)
4941 /* The max size of hash table is PREALLOC_TB_SIZE */
4942 order = PREALLOC_TB_SIZE - 1;
4944 goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex);
4946 * search for the prealloc space that is having
4947 * minimal distance from the goal block.
4949 for (i = order; i < PREALLOC_TB_SIZE; i++) {
4951 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[i],
4953 spin_lock(&tmp_pa->pa_lock);
4954 if (tmp_pa->pa_deleted == 0 &&
4955 tmp_pa->pa_free >= ac->ac_o_ex.fe_len) {
4957 cpa = ext4_mb_check_group_pa(goal_block,
4960 spin_unlock(&tmp_pa->pa_lock);
4965 ext4_mb_use_group_pa(ac, cpa);
4972 * the function goes through all preallocation in this group and marks them
4973 * used in in-core bitmap. buddy must be generated from this bitmap
4974 * Need to be called with ext4 group lock held
4976 static noinline_for_stack
4977 void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
4980 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
4981 struct ext4_prealloc_space *pa;
4982 struct list_head *cur;
4983 ext4_group_t groupnr;
4984 ext4_grpblk_t start;
4985 int preallocated = 0;
4991 /* all form of preallocation discards first load group,
4992 * so the only competing code is preallocation use.
4993 * we don't need any locking here
4994 * notice we do NOT ignore preallocations with pa_deleted
4995 * otherwise we could leave used blocks available for
4996 * allocation in buddy when concurrent ext4_mb_put_pa()
4997 * is dropping preallocation
4999 list_for_each(cur, &grp->bb_prealloc_list) {
5000 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
5001 spin_lock(&pa->pa_lock);
5002 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
5005 spin_unlock(&pa->pa_lock);
5006 if (unlikely(len == 0))
5008 BUG_ON(groupnr != group);
5009 mb_set_bits(bitmap, start, len);
5010 preallocated += len;
5012 mb_debug(sb, "preallocated %d for group %u\n", preallocated, group);
5015 static void ext4_mb_mark_pa_deleted(struct super_block *sb,
5016 struct ext4_prealloc_space *pa)
5018 struct ext4_inode_info *ei;
5020 if (pa->pa_deleted) {
5021 ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n",
5022 pa->pa_type, pa->pa_pstart, pa->pa_lstart,
5029 if (pa->pa_type == MB_INODE_PA) {
5030 ei = EXT4_I(pa->pa_inode);
5031 atomic_dec(&ei->i_prealloc_active);
5035 static inline void ext4_mb_pa_free(struct ext4_prealloc_space *pa)
5038 BUG_ON(atomic_read(&pa->pa_count));
5039 BUG_ON(pa->pa_deleted == 0);
5040 kmem_cache_free(ext4_pspace_cachep, pa);
5043 static void ext4_mb_pa_callback(struct rcu_head *head)
5045 struct ext4_prealloc_space *pa;
5047 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
5048 ext4_mb_pa_free(pa);
5052 * drops a reference to preallocated space descriptor
5053 * if this was the last reference and the space is consumed
5055 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
5056 struct super_block *sb, struct ext4_prealloc_space *pa)
5059 ext4_fsblk_t grp_blk;
5060 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
5062 /* in this short window concurrent discard can set pa_deleted */
5063 spin_lock(&pa->pa_lock);
5064 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {
5065 spin_unlock(&pa->pa_lock);
5069 if (pa->pa_deleted == 1) {
5070 spin_unlock(&pa->pa_lock);
5074 ext4_mb_mark_pa_deleted(sb, pa);
5075 spin_unlock(&pa->pa_lock);
5077 grp_blk = pa->pa_pstart;
5079 * If doing group-based preallocation, pa_pstart may be in the
5080 * next group when pa is used up
5082 if (pa->pa_type == MB_GROUP_PA)
5085 grp = ext4_get_group_number(sb, grp_blk);
5090 * P1 (buddy init) P2 (regular allocation)
5091 * find block B in PA
5092 * copy on-disk bitmap to buddy
5093 * mark B in on-disk bitmap
5094 * drop PA from group
5095 * mark all PAs in buddy
5097 * thus, P1 initializes buddy with B available. to prevent this
5098 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
5101 ext4_lock_group(sb, grp);
5102 list_del(&pa->pa_group_list);
5103 ext4_unlock_group(sb, grp);
5105 if (pa->pa_type == MB_INODE_PA) {
5106 write_lock(pa->pa_node_lock.inode_lock);
5107 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5108 write_unlock(pa->pa_node_lock.inode_lock);
5109 ext4_mb_pa_free(pa);
5111 spin_lock(pa->pa_node_lock.lg_lock);
5112 list_del_rcu(&pa->pa_node.lg_list);
5113 spin_unlock(pa->pa_node_lock.lg_lock);
5114 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
5118 static void ext4_mb_pa_rb_insert(struct rb_root *root, struct rb_node *new)
5120 struct rb_node **iter = &root->rb_node, *parent = NULL;
5121 struct ext4_prealloc_space *iter_pa, *new_pa;
5122 ext4_lblk_t iter_start, new_start;
5125 iter_pa = rb_entry(*iter, struct ext4_prealloc_space,
5126 pa_node.inode_node);
5127 new_pa = rb_entry(new, struct ext4_prealloc_space,
5128 pa_node.inode_node);
5129 iter_start = iter_pa->pa_lstart;
5130 new_start = new_pa->pa_lstart;
5133 if (new_start < iter_start)
5134 iter = &((*iter)->rb_left);
5136 iter = &((*iter)->rb_right);
5139 rb_link_node(new, parent, iter);
5140 rb_insert_color(new, root);
5144 * creates new preallocated space for given inode
5146 static noinline_for_stack void
5147 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
5149 struct super_block *sb = ac->ac_sb;
5150 struct ext4_sb_info *sbi = EXT4_SB(sb);
5151 struct ext4_prealloc_space *pa;
5152 struct ext4_group_info *grp;
5153 struct ext4_inode_info *ei;
5155 /* preallocate only when found space is larger then requested */
5156 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
5157 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
5158 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
5159 BUG_ON(ac->ac_pa == NULL);
5163 if (ac->ac_b_ex.fe_len < ac->ac_orig_goal_len) {
5164 struct ext4_free_extent ex = {
5165 .fe_logical = ac->ac_g_ex.fe_logical,
5166 .fe_len = ac->ac_orig_goal_len,
5168 loff_t orig_goal_end = extent_logical_end(sbi, &ex);
5169 loff_t o_ex_end = extent_logical_end(sbi, &ac->ac_o_ex);
5172 * We can't allocate as much as normalizer wants, so we try
5173 * to get proper lstart to cover the original request, except
5174 * when the goal doesn't cover the original request as below:
5176 * orig_ex:2045/2055(10), isize:8417280 -> normalized:0/2048
5177 * best_ex:0/200(200) -> adjusted: 1848/2048(200)
5179 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
5180 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
5183 * Use the below logic for adjusting best extent as it keeps
5184 * fragmentation in check while ensuring logical range of best
5185 * extent doesn't overflow out of goal extent:
5187 * 1. Check if best ex can be kept at end of goal (before
5188 * cr_best_avail trimmed it) and still cover original start
5189 * 2. Else, check if best ex can be kept at start of goal and
5190 * still cover original end
5191 * 3. Else, keep the best ex at start of original request.
5193 ex.fe_len = ac->ac_b_ex.fe_len;
5195 ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len);
5196 if (ac->ac_o_ex.fe_logical >= ex.fe_logical)
5199 ex.fe_logical = ac->ac_g_ex.fe_logical;
5200 if (o_ex_end <= extent_logical_end(sbi, &ex))
5203 ex.fe_logical = ac->ac_o_ex.fe_logical;
5205 ac->ac_b_ex.fe_logical = ex.fe_logical;
5207 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
5208 BUG_ON(extent_logical_end(sbi, &ex) > orig_goal_end);
5211 pa->pa_lstart = ac->ac_b_ex.fe_logical;
5212 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
5213 pa->pa_len = ac->ac_b_ex.fe_len;
5214 pa->pa_free = pa->pa_len;
5215 spin_lock_init(&pa->pa_lock);
5216 INIT_LIST_HEAD(&pa->pa_group_list);
5218 pa->pa_type = MB_INODE_PA;
5220 mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
5221 pa->pa_len, pa->pa_lstart);
5222 trace_ext4_mb_new_inode_pa(ac, pa);
5224 atomic_add(pa->pa_free, &sbi->s_mb_preallocated);
5225 ext4_mb_use_inode_pa(ac, pa);
5227 ei = EXT4_I(ac->ac_inode);
5228 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
5232 pa->pa_node_lock.inode_lock = &ei->i_prealloc_lock;
5233 pa->pa_inode = ac->ac_inode;
5235 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
5237 write_lock(pa->pa_node_lock.inode_lock);
5238 ext4_mb_pa_rb_insert(&ei->i_prealloc_node, &pa->pa_node.inode_node);
5239 write_unlock(pa->pa_node_lock.inode_lock);
5240 atomic_inc(&ei->i_prealloc_active);
5244 * creates new preallocated space for locality group inodes belongs to
5246 static noinline_for_stack void
5247 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
5249 struct super_block *sb = ac->ac_sb;
5250 struct ext4_locality_group *lg;
5251 struct ext4_prealloc_space *pa;
5252 struct ext4_group_info *grp;
5254 /* preallocate only when found space is larger then requested */
5255 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
5256 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
5257 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
5258 BUG_ON(ac->ac_pa == NULL);
5262 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
5263 pa->pa_lstart = pa->pa_pstart;
5264 pa->pa_len = ac->ac_b_ex.fe_len;
5265 pa->pa_free = pa->pa_len;
5266 spin_lock_init(&pa->pa_lock);
5267 INIT_LIST_HEAD(&pa->pa_node.lg_list);
5268 INIT_LIST_HEAD(&pa->pa_group_list);
5270 pa->pa_type = MB_GROUP_PA;
5272 mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
5273 pa->pa_len, pa->pa_lstart);
5274 trace_ext4_mb_new_group_pa(ac, pa);
5276 ext4_mb_use_group_pa(ac, pa);
5277 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
5279 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
5285 pa->pa_node_lock.lg_lock = &lg->lg_prealloc_lock;
5286 pa->pa_inode = NULL;
5288 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
5291 * We will later add the new pa to the right bucket
5292 * after updating the pa_free in ext4_mb_release_context
5296 static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
5298 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
5299 ext4_mb_new_group_pa(ac);
5301 ext4_mb_new_inode_pa(ac);
5305 * finds all unused blocks in on-disk bitmap, frees them in
5306 * in-core bitmap and buddy.
5307 * @pa must be unlinked from inode and group lists, so that
5308 * nobody else can find/use it.
5309 * the caller MUST hold group/inode locks.
5310 * TODO: optimize the case when there are no in-core structures yet
5312 static noinline_for_stack void
5313 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
5314 struct ext4_prealloc_space *pa)
5316 struct super_block *sb = e4b->bd_sb;
5317 struct ext4_sb_info *sbi = EXT4_SB(sb);
5322 unsigned long long grp_blk_start;
5325 BUG_ON(pa->pa_deleted == 0);
5326 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
5327 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
5328 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
5329 end = bit + pa->pa_len;
5332 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
5335 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
5336 mb_debug(sb, "free preallocated %u/%u in group %u\n",
5337 (unsigned) ext4_group_first_block_no(sb, group) + bit,
5338 (unsigned) next - bit, (unsigned) group);
5341 trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);
5342 trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +
5343 EXT4_C2B(sbi, bit)),
5345 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
5348 if (free != pa->pa_free) {
5349 ext4_msg(e4b->bd_sb, KERN_CRIT,
5350 "pa %p: logic %lu, phys. %lu, len %d",
5351 pa, (unsigned long) pa->pa_lstart,
5352 (unsigned long) pa->pa_pstart,
5354 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
5357 * pa is already deleted so we use the value obtained
5358 * from the bitmap and continue.
5361 atomic_add(free, &sbi->s_mb_discarded);
5364 static noinline_for_stack void
5365 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
5366 struct ext4_prealloc_space *pa)
5368 struct super_block *sb = e4b->bd_sb;
5372 trace_ext4_mb_release_group_pa(sb, pa);
5373 BUG_ON(pa->pa_deleted == 0);
5374 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
5375 if (unlikely(group != e4b->bd_group && pa->pa_len != 0)) {
5376 ext4_warning(sb, "bad group: expected %u, group %u, pa_start %llu",
5377 e4b->bd_group, group, pa->pa_pstart);
5380 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
5381 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
5382 trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);
5386 * releases all preallocations in given group
5388 * first, we need to decide discard policy:
5389 * - when do we discard
5391 * - how many do we discard
5392 * 1) how many requested
5394 static noinline_for_stack int
5395 ext4_mb_discard_group_preallocations(struct super_block *sb,
5396 ext4_group_t group, int *busy)
5398 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
5399 struct buffer_head *bitmap_bh = NULL;
5400 struct ext4_prealloc_space *pa, *tmp;
5402 struct ext4_buddy e4b;
5403 struct ext4_inode_info *ei;
5409 mb_debug(sb, "discard preallocation for group %u\n", group);
5410 if (list_empty(&grp->bb_prealloc_list))
5413 bitmap_bh = ext4_read_block_bitmap(sb, group);
5414 if (IS_ERR(bitmap_bh)) {
5415 err = PTR_ERR(bitmap_bh);
5416 ext4_error_err(sb, -err,
5417 "Error %d reading block bitmap for %u",
5422 err = ext4_mb_load_buddy(sb, group, &e4b);
5424 ext4_warning(sb, "Error %d loading buddy information for %u",
5430 ext4_lock_group(sb, group);
5431 list_for_each_entry_safe(pa, tmp,
5432 &grp->bb_prealloc_list, pa_group_list) {
5433 spin_lock(&pa->pa_lock);
5434 if (atomic_read(&pa->pa_count)) {
5435 spin_unlock(&pa->pa_lock);
5439 if (pa->pa_deleted) {
5440 spin_unlock(&pa->pa_lock);
5444 /* seems this one can be freed ... */
5445 ext4_mb_mark_pa_deleted(sb, pa);
5448 this_cpu_inc(discard_pa_seq);
5450 /* we can trust pa_free ... */
5451 free += pa->pa_free;
5453 spin_unlock(&pa->pa_lock);
5455 list_del(&pa->pa_group_list);
5456 list_add(&pa->u.pa_tmp_list, &list);
5459 /* now free all selected PAs */
5460 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
5462 /* remove from object (inode or locality group) */
5463 if (pa->pa_type == MB_GROUP_PA) {
5464 spin_lock(pa->pa_node_lock.lg_lock);
5465 list_del_rcu(&pa->pa_node.lg_list);
5466 spin_unlock(pa->pa_node_lock.lg_lock);
5468 write_lock(pa->pa_node_lock.inode_lock);
5469 ei = EXT4_I(pa->pa_inode);
5470 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5471 write_unlock(pa->pa_node_lock.inode_lock);
5474 list_del(&pa->u.pa_tmp_list);
5476 if (pa->pa_type == MB_GROUP_PA) {
5477 ext4_mb_release_group_pa(&e4b, pa);
5478 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
5480 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
5481 ext4_mb_pa_free(pa);
5485 ext4_unlock_group(sb, group);
5486 ext4_mb_unload_buddy(&e4b);
5489 mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
5490 free, group, grp->bb_free);
5495 * releases all non-used preallocated blocks for given inode
5497 * It's important to discard preallocations under i_data_sem
5498 * We don't want another block to be served from the prealloc
5499 * space when we are discarding the inode prealloc space.
5501 * FIXME!! Make sure it is valid at all the call sites
5503 void ext4_discard_preallocations(struct inode *inode)
5505 struct ext4_inode_info *ei = EXT4_I(inode);
5506 struct super_block *sb = inode->i_sb;
5507 struct buffer_head *bitmap_bh = NULL;
5508 struct ext4_prealloc_space *pa, *tmp;
5509 ext4_group_t group = 0;
5511 struct ext4_buddy e4b;
5512 struct rb_node *iter;
5515 if (!S_ISREG(inode->i_mode))
5518 if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
5521 mb_debug(sb, "discard preallocation for inode %lu\n",
5523 trace_ext4_discard_preallocations(inode,
5524 atomic_read(&ei->i_prealloc_active));
5527 /* first, collect all pa's in the inode */
5528 write_lock(&ei->i_prealloc_lock);
5529 for (iter = rb_first(&ei->i_prealloc_node); iter;
5530 iter = rb_next(iter)) {
5531 pa = rb_entry(iter, struct ext4_prealloc_space,
5532 pa_node.inode_node);
5533 BUG_ON(pa->pa_node_lock.inode_lock != &ei->i_prealloc_lock);
5535 spin_lock(&pa->pa_lock);
5536 if (atomic_read(&pa->pa_count)) {
5537 /* this shouldn't happen often - nobody should
5538 * use preallocation while we're discarding it */
5539 spin_unlock(&pa->pa_lock);
5540 write_unlock(&ei->i_prealloc_lock);
5541 ext4_msg(sb, KERN_ERR,
5542 "uh-oh! used pa while discarding");
5544 schedule_timeout_uninterruptible(HZ);
5548 if (pa->pa_deleted == 0) {
5549 ext4_mb_mark_pa_deleted(sb, pa);
5550 spin_unlock(&pa->pa_lock);
5551 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5552 list_add(&pa->u.pa_tmp_list, &list);
5556 /* someone is deleting pa right now */
5557 spin_unlock(&pa->pa_lock);
5558 write_unlock(&ei->i_prealloc_lock);
5560 /* we have to wait here because pa_deleted
5561 * doesn't mean pa is already unlinked from
5562 * the list. as we might be called from
5563 * ->clear_inode() the inode will get freed
5564 * and concurrent thread which is unlinking
5565 * pa from inode's list may access already
5566 * freed memory, bad-bad-bad */
5568 /* XXX: if this happens too often, we can
5569 * add a flag to force wait only in case
5570 * of ->clear_inode(), but not in case of
5571 * regular truncate */
5572 schedule_timeout_uninterruptible(HZ);
5575 write_unlock(&ei->i_prealloc_lock);
5577 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
5578 BUG_ON(pa->pa_type != MB_INODE_PA);
5579 group = ext4_get_group_number(sb, pa->pa_pstart);
5581 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
5582 GFP_NOFS|__GFP_NOFAIL);
5584 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5589 bitmap_bh = ext4_read_block_bitmap(sb, group);
5590 if (IS_ERR(bitmap_bh)) {
5591 err = PTR_ERR(bitmap_bh);
5592 ext4_error_err(sb, -err, "Error %d reading block bitmap for %u",
5594 ext4_mb_unload_buddy(&e4b);
5598 ext4_lock_group(sb, group);
5599 list_del(&pa->pa_group_list);
5600 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
5601 ext4_unlock_group(sb, group);
5603 ext4_mb_unload_buddy(&e4b);
5606 list_del(&pa->u.pa_tmp_list);
5607 ext4_mb_pa_free(pa);
5611 static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac)
5613 struct ext4_prealloc_space *pa;
5615 BUG_ON(ext4_pspace_cachep == NULL);
5616 pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS);
5619 atomic_set(&pa->pa_count, 1);
5624 static void ext4_mb_pa_put_free(struct ext4_allocation_context *ac)
5626 struct ext4_prealloc_space *pa = ac->ac_pa;
5630 WARN_ON(!atomic_dec_and_test(&pa->pa_count));
5632 * current function is only called due to an error or due to
5633 * len of found blocks < len of requested blocks hence the PA has not
5634 * been added to grp->bb_prealloc_list. So we don't need to lock it
5637 ext4_mb_pa_free(pa);
5640 #ifdef CONFIG_EXT4_DEBUG
5641 static inline void ext4_mb_show_pa(struct super_block *sb)
5643 ext4_group_t i, ngroups;
5645 if (ext4_forced_shutdown(sb))
5648 ngroups = ext4_get_groups_count(sb);
5649 mb_debug(sb, "groups: ");
5650 for (i = 0; i < ngroups; i++) {
5651 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
5652 struct ext4_prealloc_space *pa;
5653 ext4_grpblk_t start;
5654 struct list_head *cur;
5658 ext4_lock_group(sb, i);
5659 list_for_each(cur, &grp->bb_prealloc_list) {
5660 pa = list_entry(cur, struct ext4_prealloc_space,
5662 spin_lock(&pa->pa_lock);
5663 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
5665 spin_unlock(&pa->pa_lock);
5666 mb_debug(sb, "PA:%u:%d:%d\n", i, start,
5669 ext4_unlock_group(sb, i);
5670 mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free,
5675 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5677 struct super_block *sb = ac->ac_sb;
5679 if (ext4_forced_shutdown(sb))
5682 mb_debug(sb, "Can't allocate:"
5683 " Allocation context details:");
5684 mb_debug(sb, "status %u flags 0x%x",
5685 ac->ac_status, ac->ac_flags);
5686 mb_debug(sb, "orig %lu/%lu/%lu@%lu, "
5687 "goal %lu/%lu/%lu@%lu, "
5688 "best %lu/%lu/%lu@%lu cr %d",
5689 (unsigned long)ac->ac_o_ex.fe_group,
5690 (unsigned long)ac->ac_o_ex.fe_start,
5691 (unsigned long)ac->ac_o_ex.fe_len,
5692 (unsigned long)ac->ac_o_ex.fe_logical,
5693 (unsigned long)ac->ac_g_ex.fe_group,
5694 (unsigned long)ac->ac_g_ex.fe_start,
5695 (unsigned long)ac->ac_g_ex.fe_len,
5696 (unsigned long)ac->ac_g_ex.fe_logical,
5697 (unsigned long)ac->ac_b_ex.fe_group,
5698 (unsigned long)ac->ac_b_ex.fe_start,
5699 (unsigned long)ac->ac_b_ex.fe_len,
5700 (unsigned long)ac->ac_b_ex.fe_logical,
5701 (int)ac->ac_criteria);
5702 mb_debug(sb, "%u found", ac->ac_found);
5703 mb_debug(sb, "used pa: %s, ", ac->ac_pa ? "yes" : "no");
5705 mb_debug(sb, "pa_type %s\n", ac->ac_pa->pa_type == MB_GROUP_PA ?
5706 "group pa" : "inode pa");
5707 ext4_mb_show_pa(sb);
5710 static inline void ext4_mb_show_pa(struct super_block *sb)
5713 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5715 ext4_mb_show_pa(ac->ac_sb);
5720 * We use locality group preallocation for small size file. The size of the
5721 * file is determined by the current size or the resulting size after
5722 * allocation which ever is larger
5724 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
5726 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
5728 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
5729 int bsbits = ac->ac_sb->s_blocksize_bits;
5731 bool inode_pa_eligible, group_pa_eligible;
5733 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
5736 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
5739 group_pa_eligible = sbi->s_mb_group_prealloc > 0;
5740 inode_pa_eligible = true;
5741 size = extent_logical_end(sbi, &ac->ac_o_ex);
5742 isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
5745 /* No point in using inode preallocation for closed files */
5746 if ((size == isize) && !ext4_fs_is_busy(sbi) &&
5747 !inode_is_open_for_write(ac->ac_inode))
5748 inode_pa_eligible = false;
5750 size = max(size, isize);
5751 /* Don't use group allocation for large files */
5752 if (size > sbi->s_mb_stream_request)
5753 group_pa_eligible = false;
5755 if (!group_pa_eligible) {
5756 if (inode_pa_eligible)
5757 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
5759 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
5763 BUG_ON(ac->ac_lg != NULL);
5765 * locality group prealloc space are per cpu. The reason for having
5766 * per cpu locality group is to reduce the contention between block
5767 * request from multiple CPUs.
5769 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
5771 /* we're going to use group allocation */
5772 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
5774 /* serialize all allocations in the group */
5775 mutex_lock(&ac->ac_lg->lg_mutex);
5778 static noinline_for_stack void
5779 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
5780 struct ext4_allocation_request *ar)
5782 struct super_block *sb = ar->inode->i_sb;
5783 struct ext4_sb_info *sbi = EXT4_SB(sb);
5784 struct ext4_super_block *es = sbi->s_es;
5788 ext4_grpblk_t block;
5790 /* we can't allocate > group size */
5793 /* just a dirty hack to filter too big requests */
5794 if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
5795 len = EXT4_CLUSTERS_PER_GROUP(sb);
5797 /* start searching from the goal */
5799 if (goal < le32_to_cpu(es->s_first_data_block) ||
5800 goal >= ext4_blocks_count(es))
5801 goal = le32_to_cpu(es->s_first_data_block);
5802 ext4_get_group_no_and_offset(sb, goal, &group, &block);
5804 /* set up allocation goals */
5805 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
5806 ac->ac_status = AC_STATUS_CONTINUE;
5808 ac->ac_inode = ar->inode;
5809 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
5810 ac->ac_o_ex.fe_group = group;
5811 ac->ac_o_ex.fe_start = block;
5812 ac->ac_o_ex.fe_len = len;
5813 ac->ac_g_ex = ac->ac_o_ex;
5814 ac->ac_orig_goal_len = ac->ac_g_ex.fe_len;
5815 ac->ac_flags = ar->flags;
5817 /* we have to define context: we'll work with a file or
5818 * locality group. this is a policy, actually */
5819 ext4_mb_group_or_file(ac);
5821 mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, "
5822 "left: %u/%u, right %u/%u to %swritable\n",
5823 (unsigned) ar->len, (unsigned) ar->logical,
5824 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
5825 (unsigned) ar->lleft, (unsigned) ar->pleft,
5826 (unsigned) ar->lright, (unsigned) ar->pright,
5827 inode_is_open_for_write(ar->inode) ? "" : "non-");
5830 static noinline_for_stack void
5831 ext4_mb_discard_lg_preallocations(struct super_block *sb,
5832 struct ext4_locality_group *lg,
5833 int order, int total_entries)
5835 ext4_group_t group = 0;
5836 struct ext4_buddy e4b;
5837 LIST_HEAD(discard_list);
5838 struct ext4_prealloc_space *pa, *tmp;
5840 mb_debug(sb, "discard locality group preallocation\n");
5842 spin_lock(&lg->lg_prealloc_lock);
5843 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
5845 lockdep_is_held(&lg->lg_prealloc_lock)) {
5846 spin_lock(&pa->pa_lock);
5847 if (atomic_read(&pa->pa_count)) {
5849 * This is the pa that we just used
5850 * for block allocation. So don't
5853 spin_unlock(&pa->pa_lock);
5856 if (pa->pa_deleted) {
5857 spin_unlock(&pa->pa_lock);
5860 /* only lg prealloc space */
5861 BUG_ON(pa->pa_type != MB_GROUP_PA);
5863 /* seems this one can be freed ... */
5864 ext4_mb_mark_pa_deleted(sb, pa);
5865 spin_unlock(&pa->pa_lock);
5867 list_del_rcu(&pa->pa_node.lg_list);
5868 list_add(&pa->u.pa_tmp_list, &discard_list);
5871 if (total_entries <= 5) {
5873 * we want to keep only 5 entries
5874 * allowing it to grow to 8. This
5875 * mak sure we don't call discard
5876 * soon for this list.
5881 spin_unlock(&lg->lg_prealloc_lock);
5883 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
5886 group = ext4_get_group_number(sb, pa->pa_pstart);
5887 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
5888 GFP_NOFS|__GFP_NOFAIL);
5890 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5894 ext4_lock_group(sb, group);
5895 list_del(&pa->pa_group_list);
5896 ext4_mb_release_group_pa(&e4b, pa);
5897 ext4_unlock_group(sb, group);
5899 ext4_mb_unload_buddy(&e4b);
5900 list_del(&pa->u.pa_tmp_list);
5901 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
5906 * We have incremented pa_count. So it cannot be freed at this
5907 * point. Also we hold lg_mutex. So no parallel allocation is
5908 * possible from this lg. That means pa_free cannot be updated.
5910 * A parallel ext4_mb_discard_group_preallocations is possible.
5911 * which can cause the lg_prealloc_list to be updated.
5914 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
5916 int order, added = 0, lg_prealloc_count = 1;
5917 struct super_block *sb = ac->ac_sb;
5918 struct ext4_locality_group *lg = ac->ac_lg;
5919 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
5921 order = fls(pa->pa_free) - 1;
5922 if (order > PREALLOC_TB_SIZE - 1)
5923 /* The max size of hash table is PREALLOC_TB_SIZE */
5924 order = PREALLOC_TB_SIZE - 1;
5925 /* Add the prealloc space to lg */
5926 spin_lock(&lg->lg_prealloc_lock);
5927 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
5929 lockdep_is_held(&lg->lg_prealloc_lock)) {
5930 spin_lock(&tmp_pa->pa_lock);
5931 if (tmp_pa->pa_deleted) {
5932 spin_unlock(&tmp_pa->pa_lock);
5935 if (!added && pa->pa_free < tmp_pa->pa_free) {
5936 /* Add to the tail of the previous entry */
5937 list_add_tail_rcu(&pa->pa_node.lg_list,
5938 &tmp_pa->pa_node.lg_list);
5941 * we want to count the total
5942 * number of entries in the list
5945 spin_unlock(&tmp_pa->pa_lock);
5946 lg_prealloc_count++;
5949 list_add_tail_rcu(&pa->pa_node.lg_list,
5950 &lg->lg_prealloc_list[order]);
5951 spin_unlock(&lg->lg_prealloc_lock);
5953 /* Now trim the list to be not more than 8 elements */
5954 if (lg_prealloc_count > 8)
5955 ext4_mb_discard_lg_preallocations(sb, lg,
5956 order, lg_prealloc_count);
5960 * release all resource we used in allocation
5962 static void ext4_mb_release_context(struct ext4_allocation_context *ac)
5964 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
5965 struct ext4_prealloc_space *pa = ac->ac_pa;
5967 if (pa->pa_type == MB_GROUP_PA) {
5968 /* see comment in ext4_mb_use_group_pa() */
5969 spin_lock(&pa->pa_lock);
5970 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
5971 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
5972 pa->pa_free -= ac->ac_b_ex.fe_len;
5973 pa->pa_len -= ac->ac_b_ex.fe_len;
5974 spin_unlock(&pa->pa_lock);
5977 * We want to add the pa to the right bucket.
5978 * Remove it from the list and while adding
5979 * make sure the list to which we are adding
5982 if (likely(pa->pa_free)) {
5983 spin_lock(pa->pa_node_lock.lg_lock);
5984 list_del_rcu(&pa->pa_node.lg_list);
5985 spin_unlock(pa->pa_node_lock.lg_lock);
5986 ext4_mb_add_n_trim(ac);
5990 ext4_mb_put_pa(ac, ac->ac_sb, pa);
5992 if (ac->ac_bitmap_page)
5993 put_page(ac->ac_bitmap_page);
5994 if (ac->ac_buddy_page)
5995 put_page(ac->ac_buddy_page);
5996 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
5997 mutex_unlock(&ac->ac_lg->lg_mutex);
5998 ext4_mb_collect_stats(ac);
6001 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
6003 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
6005 int freed = 0, busy = 0;
6008 trace_ext4_mb_discard_preallocations(sb, needed);
6011 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
6013 for (i = 0; i < ngroups && needed > 0; i++) {
6014 ret = ext4_mb_discard_group_preallocations(sb, i, &busy);
6020 if (needed > 0 && busy && ++retry < 3) {
6028 static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb,
6029 struct ext4_allocation_context *ac, u64 *seq)
6035 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
6040 seq_retry = ext4_get_discard_pa_seq_sum();
6041 if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) {
6042 ac->ac_flags |= EXT4_MB_STRICT_CHECK;
6048 mb_debug(sb, "freed %d, retry ? %s\n", freed, ret ? "yes" : "no");
6053 * Simple allocator for Ext4 fast commit replay path. It searches for blocks
6054 * linearly starting at the goal block and also excludes the blocks which
6055 * are going to be in use after fast commit replay.
6058 ext4_mb_new_blocks_simple(struct ext4_allocation_request *ar, int *errp)
6060 struct buffer_head *bitmap_bh;
6061 struct super_block *sb = ar->inode->i_sb;
6062 struct ext4_sb_info *sbi = EXT4_SB(sb);
6063 ext4_group_t group, nr;
6064 ext4_grpblk_t blkoff;
6065 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
6066 ext4_grpblk_t i = 0;
6067 ext4_fsblk_t goal, block;
6068 struct ext4_super_block *es = sbi->s_es;
6071 if (goal < le32_to_cpu(es->s_first_data_block) ||
6072 goal >= ext4_blocks_count(es))
6073 goal = le32_to_cpu(es->s_first_data_block);
6076 ext4_get_group_no_and_offset(sb, goal, &group, &blkoff);
6077 for (nr = ext4_get_groups_count(sb); nr > 0; nr--) {
6078 bitmap_bh = ext4_read_block_bitmap(sb, group);
6079 if (IS_ERR(bitmap_bh)) {
6080 *errp = PTR_ERR(bitmap_bh);
6081 pr_warn("Failed to read block bitmap\n");
6086 i = mb_find_next_zero_bit(bitmap_bh->b_data, max,
6090 if (ext4_fc_replay_check_excluded(sb,
6091 ext4_group_first_block_no(sb, group) +
6092 EXT4_C2B(sbi, i))) {
6101 if (++group >= ext4_get_groups_count(sb))
6112 block = ext4_group_first_block_no(sb, group) + EXT4_C2B(sbi, i);
6113 ext4_mb_mark_bb(sb, block, 1, true);
6120 * Main entry point into mballoc to allocate blocks
6121 * it tries to use preallocation first, then falls back
6122 * to usual allocation
6124 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
6125 struct ext4_allocation_request *ar, int *errp)
6127 struct ext4_allocation_context *ac = NULL;
6128 struct ext4_sb_info *sbi;
6129 struct super_block *sb;
6130 ext4_fsblk_t block = 0;
6131 unsigned int inquota = 0;
6132 unsigned int reserv_clstrs = 0;
6137 sb = ar->inode->i_sb;
6140 trace_ext4_request_blocks(ar);
6141 if (sbi->s_mount_state & EXT4_FC_REPLAY)
6142 return ext4_mb_new_blocks_simple(ar, errp);
6144 /* Allow to use superuser reservation for quota file */
6145 if (ext4_is_quota_file(ar->inode))
6146 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
6148 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
6149 /* Without delayed allocation we need to verify
6150 * there is enough free blocks to do block allocation
6151 * and verify allocation doesn't exceed the quota limits.
6154 ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
6156 /* let others to free the space */
6158 ar->len = ar->len >> 1;
6161 ext4_mb_show_pa(sb);
6165 reserv_clstrs = ar->len;
6166 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
6167 dquot_alloc_block_nofail(ar->inode,
6168 EXT4_C2B(sbi, ar->len));
6171 dquot_alloc_block(ar->inode,
6172 EXT4_C2B(sbi, ar->len))) {
6174 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
6185 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
6192 ext4_mb_initialize_context(ac, ar);
6194 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
6195 seq = this_cpu_read(discard_pa_seq);
6196 if (!ext4_mb_use_preallocated(ac)) {
6197 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
6198 ext4_mb_normalize_request(ac, ar);
6200 *errp = ext4_mb_pa_alloc(ac);
6204 /* allocate space in core */
6205 *errp = ext4_mb_regular_allocator(ac);
6207 * pa allocated above is added to grp->bb_prealloc_list only
6208 * when we were able to allocate some block i.e. when
6209 * ac->ac_status == AC_STATUS_FOUND.
6210 * And error from above mean ac->ac_status != AC_STATUS_FOUND
6211 * So we have to free this pa here itself.
6214 ext4_mb_pa_put_free(ac);
6215 ext4_discard_allocated_blocks(ac);
6218 if (ac->ac_status == AC_STATUS_FOUND &&
6219 ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len)
6220 ext4_mb_pa_put_free(ac);
6222 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
6223 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
6225 ext4_discard_allocated_blocks(ac);
6228 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
6229 ar->len = ac->ac_b_ex.fe_len;
6232 if (++retries < 3 &&
6233 ext4_mb_discard_preallocations_should_retry(sb, ac, &seq))
6236 * If block allocation fails then the pa allocated above
6237 * needs to be freed here itself.
6239 ext4_mb_pa_put_free(ac);
6245 ac->ac_b_ex.fe_len = 0;
6247 ext4_mb_show_ac(ac);
6249 ext4_mb_release_context(ac);
6250 kmem_cache_free(ext4_ac_cachep, ac);
6252 if (inquota && ar->len < inquota)
6253 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
6255 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
6256 /* release all the reserved blocks if non delalloc */
6257 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
6261 trace_ext4_allocate_blocks(ar, (unsigned long long)block);
6267 * We can merge two free data extents only if the physical blocks
6268 * are contiguous, AND the extents were freed by the same transaction,
6269 * AND the blocks are associated with the same group.
6271 static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
6272 struct ext4_free_data *entry,
6273 struct ext4_free_data *new_entry,
6274 struct rb_root *entry_rb_root)
6276 if ((entry->efd_tid != new_entry->efd_tid) ||
6277 (entry->efd_group != new_entry->efd_group))
6279 if (entry->efd_start_cluster + entry->efd_count ==
6280 new_entry->efd_start_cluster) {
6281 new_entry->efd_start_cluster = entry->efd_start_cluster;
6282 new_entry->efd_count += entry->efd_count;
6283 } else if (new_entry->efd_start_cluster + new_entry->efd_count ==
6284 entry->efd_start_cluster) {
6285 new_entry->efd_count += entry->efd_count;
6288 spin_lock(&sbi->s_md_lock);
6289 list_del(&entry->efd_list);
6290 spin_unlock(&sbi->s_md_lock);
6291 rb_erase(&entry->efd_node, entry_rb_root);
6292 kmem_cache_free(ext4_free_data_cachep, entry);
6295 static noinline_for_stack void
6296 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
6297 struct ext4_free_data *new_entry)
6299 ext4_group_t group = e4b->bd_group;
6300 ext4_grpblk_t cluster;
6301 ext4_grpblk_t clusters = new_entry->efd_count;
6302 struct ext4_free_data *entry;
6303 struct ext4_group_info *db = e4b->bd_info;
6304 struct super_block *sb = e4b->bd_sb;
6305 struct ext4_sb_info *sbi = EXT4_SB(sb);
6306 struct rb_node **n = &db->bb_free_root.rb_node, *node;
6307 struct rb_node *parent = NULL, *new_node;
6309 BUG_ON(!ext4_handle_valid(handle));
6310 BUG_ON(e4b->bd_bitmap_page == NULL);
6311 BUG_ON(e4b->bd_buddy_page == NULL);
6313 new_node = &new_entry->efd_node;
6314 cluster = new_entry->efd_start_cluster;
6317 /* first free block exent. We need to
6318 protect buddy cache from being freed,
6319 * otherwise we'll refresh it from
6320 * on-disk bitmap and lose not-yet-available
6322 get_page(e4b->bd_buddy_page);
6323 get_page(e4b->bd_bitmap_page);
6327 entry = rb_entry(parent, struct ext4_free_data, efd_node);
6328 if (cluster < entry->efd_start_cluster)
6330 else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
6331 n = &(*n)->rb_right;
6333 ext4_grp_locked_error(sb, group, 0,
6334 ext4_group_first_block_no(sb, group) +
6335 EXT4_C2B(sbi, cluster),
6336 "Block already on to-be-freed list");
6337 kmem_cache_free(ext4_free_data_cachep, new_entry);
6342 rb_link_node(new_node, parent, n);
6343 rb_insert_color(new_node, &db->bb_free_root);
6345 /* Now try to see the extent can be merged to left and right */
6346 node = rb_prev(new_node);
6348 entry = rb_entry(node, struct ext4_free_data, efd_node);
6349 ext4_try_merge_freed_extent(sbi, entry, new_entry,
6350 &(db->bb_free_root));
6353 node = rb_next(new_node);
6355 entry = rb_entry(node, struct ext4_free_data, efd_node);
6356 ext4_try_merge_freed_extent(sbi, entry, new_entry,
6357 &(db->bb_free_root));
6360 spin_lock(&sbi->s_md_lock);
6361 list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list[new_entry->efd_tid & 1]);
6362 sbi->s_mb_free_pending += clusters;
6363 spin_unlock(&sbi->s_md_lock);
6366 static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
6367 unsigned long count)
6369 struct super_block *sb = inode->i_sb;
6371 ext4_grpblk_t blkoff;
6373 ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
6374 ext4_mb_mark_context(NULL, sb, false, group, blkoff, count,
6375 EXT4_MB_BITMAP_MARKED_CHECK |
6376 EXT4_MB_SYNC_UPDATE,
6381 * ext4_mb_clear_bb() -- helper function for freeing blocks.
6382 * Used by ext4_free_blocks()
6383 * @handle: handle for this transaction
6385 * @block: starting physical block to be freed
6386 * @count: number of blocks to be freed
6387 * @flags: flags used by ext4_free_blocks
6389 static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
6390 ext4_fsblk_t block, unsigned long count,
6393 struct super_block *sb = inode->i_sb;
6394 struct ext4_group_info *grp;
6395 unsigned int overflow;
6397 ext4_group_t block_group;
6398 struct ext4_sb_info *sbi;
6399 struct ext4_buddy e4b;
6400 unsigned int count_clusters;
6403 ext4_grpblk_t changed;
6407 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6408 !ext4_inode_block_valid(inode, block, count)) {
6409 ext4_error(sb, "Freeing blocks in system zone - "
6410 "Block = %llu, count = %lu", block, count);
6411 /* err = 0. ext4_std_error should be a no op */
6414 flags |= EXT4_FREE_BLOCKS_VALIDATED;
6418 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
6420 grp = ext4_get_group_info(sb, block_group);
6421 if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
6425 * Check to see if we are freeing blocks across a group
6428 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
6429 overflow = EXT4_C2B(sbi, bit) + count -
6430 EXT4_BLOCKS_PER_GROUP(sb);
6432 /* The range changed so it's no longer validated */
6433 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6435 count_clusters = EXT4_NUM_B2C(sbi, count);
6436 trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters);
6438 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
6439 err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b,
6440 GFP_NOFS|__GFP_NOFAIL);
6444 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6445 !ext4_inode_block_valid(inode, block, count)) {
6446 ext4_error(sb, "Freeing blocks in system zone - "
6447 "Block = %llu, count = %lu", block, count);
6448 /* err = 0. ext4_std_error should be a no op */
6452 #ifdef AGGRESSIVE_CHECK
6453 mark_flags |= EXT4_MB_BITMAP_MARKED_CHECK;
6455 err = ext4_mb_mark_context(handle, sb, false, block_group, bit,
6456 count_clusters, mark_flags, &changed);
6459 if (err && changed == 0)
6462 #ifdef AGGRESSIVE_CHECK
6463 BUG_ON(changed != count_clusters);
6467 * We need to make sure we don't reuse the freed block until after the
6468 * transaction is committed. We make an exception if the inode is to be
6469 * written in writeback mode since writeback mode has weak data
6470 * consistency guarantees.
6472 if (ext4_handle_valid(handle) &&
6473 ((flags & EXT4_FREE_BLOCKS_METADATA) ||
6474 !ext4_should_writeback_data(inode))) {
6475 struct ext4_free_data *new_entry;
6477 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
6480 new_entry = kmem_cache_alloc(ext4_free_data_cachep,
6481 GFP_NOFS|__GFP_NOFAIL);
6482 new_entry->efd_start_cluster = bit;
6483 new_entry->efd_group = block_group;
6484 new_entry->efd_count = count_clusters;
6485 new_entry->efd_tid = handle->h_transaction->t_tid;
6487 ext4_lock_group(sb, block_group);
6488 ext4_mb_free_metadata(handle, &e4b, new_entry);
6490 if (test_opt(sb, DISCARD)) {
6491 err = ext4_issue_discard(sb, block_group, bit,
6494 * Ignore EOPNOTSUPP error. This is consistent with
6495 * what happens when using journal.
6497 if (err == -EOPNOTSUPP)
6500 ext4_msg(sb, KERN_WARNING, "discard request in"
6501 " group:%u block:%d count:%lu failed"
6502 " with %d", block_group, bit, count,
6505 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
6507 ext4_lock_group(sb, block_group);
6508 mb_free_blocks(inode, &e4b, bit, count_clusters);
6511 ext4_unlock_group(sb, block_group);
6514 * on a bigalloc file system, defer the s_freeclusters_counter
6515 * update to the caller (ext4_remove_space and friends) so they
6516 * can determine if a cluster freed here should be rereserved
6518 if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
6519 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
6520 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
6521 percpu_counter_add(&sbi->s_freeclusters_counter,
6525 if (overflow && !err) {
6528 ext4_mb_unload_buddy(&e4b);
6529 /* The range changed so it's no longer validated */
6530 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6535 ext4_mb_unload_buddy(&e4b);
6537 ext4_std_error(sb, err);
6541 * ext4_free_blocks() -- Free given blocks and update quota
6542 * @handle: handle for this transaction
6544 * @bh: optional buffer of the block to be freed
6545 * @block: starting physical block to be freed
6546 * @count: number of blocks to be freed
6547 * @flags: flags used by ext4_free_blocks
6549 void ext4_free_blocks(handle_t *handle, struct inode *inode,
6550 struct buffer_head *bh, ext4_fsblk_t block,
6551 unsigned long count, int flags)
6553 struct super_block *sb = inode->i_sb;
6554 unsigned int overflow;
6555 struct ext4_sb_info *sbi;
6561 BUG_ON(block != bh->b_blocknr);
6563 block = bh->b_blocknr;
6566 if (sbi->s_mount_state & EXT4_FC_REPLAY) {
6567 ext4_free_blocks_simple(inode, block, EXT4_NUM_B2C(sbi, count));
6573 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6574 !ext4_inode_block_valid(inode, block, count)) {
6575 ext4_error(sb, "Freeing blocks not in datazone - "
6576 "block = %llu, count = %lu", block, count);
6579 flags |= EXT4_FREE_BLOCKS_VALIDATED;
6581 ext4_debug("freeing block %llu\n", block);
6582 trace_ext4_free_blocks(inode, block, count, flags);
6584 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
6587 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
6592 * If the extent to be freed does not begin on a cluster
6593 * boundary, we need to deal with partial clusters at the
6594 * beginning and end of the extent. Normally we will free
6595 * blocks at the beginning or the end unless we are explicitly
6596 * requested to avoid doing so.
6598 overflow = EXT4_PBLK_COFF(sbi, block);
6600 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
6601 overflow = sbi->s_cluster_ratio - overflow;
6603 if (count > overflow)
6611 /* The range changed so it's no longer validated */
6612 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6614 overflow = EXT4_LBLK_COFF(sbi, count);
6616 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
6617 if (count > overflow)
6622 count += sbi->s_cluster_ratio - overflow;
6623 /* The range changed so it's no longer validated */
6624 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6627 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
6629 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
6631 for (i = 0; i < count; i++) {
6634 bh = sb_find_get_block(inode->i_sb, block + i);
6635 ext4_forget(handle, is_metadata, inode, bh, block + i);
6639 ext4_mb_clear_bb(handle, inode, block, count, flags);
6643 * ext4_group_add_blocks() -- Add given blocks to an existing group
6644 * @handle: handle to this transaction
6646 * @block: start physical block to add to the block group
6647 * @count: number of blocks to free
6649 * This marks the blocks as free in the bitmap and buddy.
6651 int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
6652 ext4_fsblk_t block, unsigned long count)
6654 ext4_group_t block_group;
6656 struct ext4_sb_info *sbi = EXT4_SB(sb);
6657 struct ext4_buddy e4b;
6659 ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
6660 ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
6661 unsigned long cluster_count = last_cluster - first_cluster + 1;
6662 ext4_grpblk_t changed;
6664 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
6666 if (cluster_count == 0)
6669 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
6671 * Check to see if we are freeing blocks across a group
6674 if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
6675 ext4_warning(sb, "too many blocks added to group %u",
6681 err = ext4_mb_load_buddy(sb, block_group, &e4b);
6685 if (!ext4_sb_block_valid(sb, NULL, block, count)) {
6686 ext4_error(sb, "Adding blocks in system zones - "
6687 "Block = %llu, count = %lu",
6693 err = ext4_mb_mark_context(handle, sb, false, block_group, bit,
6694 cluster_count, EXT4_MB_BITMAP_MARKED_CHECK,
6696 if (err && changed == 0)
6699 if (changed != cluster_count)
6700 ext4_error(sb, "bit already cleared in group %u", block_group);
6702 ext4_lock_group(sb, block_group);
6703 mb_free_blocks(NULL, &e4b, bit, cluster_count);
6704 ext4_unlock_group(sb, block_group);
6705 percpu_counter_add(&sbi->s_freeclusters_counter,
6709 ext4_mb_unload_buddy(&e4b);
6711 ext4_std_error(sb, err);
6716 * ext4_trim_extent -- function to TRIM one single free extent in the group
6717 * @sb: super block for the file system
6718 * @start: starting block of the free extent in the alloc. group
6719 * @count: number of blocks to TRIM
6720 * @e4b: ext4 buddy for the group
6722 * Trim "count" blocks starting at "start" in the "group". To assure that no
6723 * one will allocate those blocks, mark it as used in buddy bitmap. This must
6724 * be called with under the group lock.
6726 static int ext4_trim_extent(struct super_block *sb,
6727 int start, int count, struct ext4_buddy *e4b)
6731 struct ext4_free_extent ex;
6732 ext4_group_t group = e4b->bd_group;
6735 trace_ext4_trim_extent(sb, group, start, count);
6737 assert_spin_locked(ext4_group_lock_ptr(sb, group));
6739 ex.fe_start = start;
6740 ex.fe_group = group;
6744 * Mark blocks used, so no one can reuse them while
6747 mb_mark_used(e4b, &ex);
6748 ext4_unlock_group(sb, group);
6749 ret = ext4_issue_discard(sb, group, start, count);
6750 ext4_lock_group(sb, group);
6751 mb_free_blocks(NULL, e4b, start, ex.fe_len);
6755 static ext4_grpblk_t ext4_last_grp_cluster(struct super_block *sb,
6758 unsigned long nr_clusters_in_group;
6760 if (grp < (ext4_get_groups_count(sb) - 1))
6761 nr_clusters_in_group = EXT4_CLUSTERS_PER_GROUP(sb);
6763 nr_clusters_in_group = (ext4_blocks_count(EXT4_SB(sb)->s_es) -
6764 ext4_group_first_block_no(sb, grp))
6765 >> EXT4_CLUSTER_BITS(sb);
6767 return nr_clusters_in_group - 1;
6770 static bool ext4_trim_interrupted(void)
6772 return fatal_signal_pending(current) || freezing(current);
6775 static int ext4_try_to_trim_range(struct super_block *sb,
6776 struct ext4_buddy *e4b, ext4_grpblk_t start,
6777 ext4_grpblk_t max, ext4_grpblk_t minblocks)
6778 __acquires(ext4_group_lock_ptr(sb, e4b->bd_group))
6779 __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
6781 ext4_grpblk_t next, count, free_count, last, origin_start;
6782 bool set_trimmed = false;
6785 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
6788 last = ext4_last_grp_cluster(sb, e4b->bd_group);
6789 bitmap = e4b->bd_bitmap;
6790 if (start == 0 && max >= last)
6792 origin_start = start;
6793 start = max(e4b->bd_info->bb_first_free, start);
6797 while (start <= max) {
6798 start = mb_find_next_zero_bit(bitmap, max + 1, start);
6802 next = mb_find_next_bit(bitmap, last + 1, start);
6803 if (origin_start == 0 && next >= last)
6806 if ((next - start) >= minblocks) {
6807 int ret = ext4_trim_extent(sb, start, next - start, e4b);
6809 if (ret && ret != -EOPNOTSUPP)
6811 count += next - start;
6813 free_count += next - start;
6816 if (ext4_trim_interrupted())
6819 if (need_resched()) {
6820 ext4_unlock_group(sb, e4b->bd_group);
6822 ext4_lock_group(sb, e4b->bd_group);
6825 if ((e4b->bd_info->bb_free - free_count) < minblocks)
6830 EXT4_MB_GRP_SET_TRIMMED(e4b->bd_info);
6836 * ext4_trim_all_free -- function to trim all free space in alloc. group
6837 * @sb: super block for file system
6838 * @group: group to be trimmed
6839 * @start: first group block to examine
6840 * @max: last group block to examine
6841 * @minblocks: minimum extent block count
6843 * ext4_trim_all_free walks through group's block bitmap searching for free
6844 * extents. When the free extent is found, mark it as used in group buddy
6845 * bitmap. Then issue a TRIM command on this extent and free the extent in
6846 * the group buddy bitmap.
6848 static ext4_grpblk_t
6849 ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
6850 ext4_grpblk_t start, ext4_grpblk_t max,
6851 ext4_grpblk_t minblocks)
6853 struct ext4_buddy e4b;
6856 trace_ext4_trim_all_free(sb, group, start, max);
6858 ret = ext4_mb_load_buddy(sb, group, &e4b);
6860 ext4_warning(sb, "Error %d loading buddy information for %u",
6865 ext4_lock_group(sb, group);
6867 if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) ||
6868 minblocks < EXT4_SB(sb)->s_last_trim_minblks)
6869 ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks);
6873 ext4_unlock_group(sb, group);
6874 ext4_mb_unload_buddy(&e4b);
6876 ext4_debug("trimmed %d blocks in the group %d\n",
6883 * ext4_trim_fs() -- trim ioctl handle function
6884 * @sb: superblock for filesystem
6885 * @range: fstrim_range structure
6887 * start: First Byte to trim
6888 * len: number of Bytes to trim from start
6889 * minlen: minimum extent length in Bytes
6890 * ext4_trim_fs goes through all allocation groups containing Bytes from
6891 * start to start+len. For each such a group ext4_trim_all_free function
6892 * is invoked to trim all free space.
6894 int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
6896 unsigned int discard_granularity = bdev_discard_granularity(sb->s_bdev);
6897 struct ext4_group_info *grp;
6898 ext4_group_t group, first_group, last_group;
6899 ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
6900 uint64_t start, end, minlen, trimmed = 0;
6901 ext4_fsblk_t first_data_blk =
6902 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
6903 ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es);
6906 start = range->start >> sb->s_blocksize_bits;
6907 end = start + (range->len >> sb->s_blocksize_bits) - 1;
6908 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
6909 range->minlen >> sb->s_blocksize_bits);
6911 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
6912 start >= max_blks ||
6913 range->len < sb->s_blocksize)
6915 /* No point to try to trim less than discard granularity */
6916 if (range->minlen < discard_granularity) {
6917 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
6918 discard_granularity >> sb->s_blocksize_bits);
6919 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb))
6922 if (end >= max_blks - 1)
6924 if (end <= first_data_blk)
6926 if (start < first_data_blk)
6927 start = first_data_blk;
6929 /* Determine first and last group to examine based on start and end */
6930 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,
6931 &first_group, &first_cluster);
6932 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end,
6933 &last_group, &last_cluster);
6935 /* end now represents the last cluster to discard in this group */
6936 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
6938 for (group = first_group; group <= last_group; group++) {
6939 if (ext4_trim_interrupted())
6941 grp = ext4_get_group_info(sb, group);
6944 /* We only do this if the grp has never been initialized */
6945 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
6946 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
6952 * For all the groups except the last one, last cluster will
6953 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
6954 * change it for the last group, note that last_cluster is
6955 * already computed earlier by ext4_get_group_no_and_offset()
6957 if (group == last_group)
6959 if (grp->bb_free >= minlen) {
6960 cnt = ext4_trim_all_free(sb, group, first_cluster,
6970 * For every group except the first one, we are sure
6971 * that the first cluster to discard will be cluster #0.
6977 EXT4_SB(sb)->s_last_trim_minblks = minlen;
6980 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
6984 /* Iterate all the free extents in the group. */
6986 ext4_mballoc_query_range(
6987 struct super_block *sb,
6989 ext4_grpblk_t start,
6991 ext4_mballoc_query_range_fn formatter,
6996 struct ext4_buddy e4b;
6999 error = ext4_mb_load_buddy(sb, group, &e4b);
7002 bitmap = e4b.bd_bitmap;
7004 ext4_lock_group(sb, group);
7006 start = max(e4b.bd_info->bb_first_free, start);
7007 if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
7008 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
7010 while (start <= end) {
7011 start = mb_find_next_zero_bit(bitmap, end + 1, start);
7014 next = mb_find_next_bit(bitmap, end + 1, start);
7016 ext4_unlock_group(sb, group);
7017 error = formatter(sb, group, start, next - start, priv);
7020 ext4_lock_group(sb, group);
7025 ext4_unlock_group(sb, group);
7027 ext4_mb_unload_buddy(&e4b);
7032 #ifdef CONFIG_EXT4_KUNIT_TESTS
7033 #include "mballoc-test.c"