arm64: dts: Revert "specify console via command line"
[linux/fpc-iii.git] / fs / ext4 / mballoc.c
blob51a78eb65f3cf64744dd82a7ed0735f350a4459f
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
4 * Written by Alex Tomas <alex@clusterfs.com>
5 */
8 /*
9 * mballoc.c contains the multiblocks allocation routines
12 #include "ext4_jbd2.h"
13 #include "mballoc.h"
14 #include <linux/log2.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/nospec.h>
18 #include <linux/backing-dev.h>
19 #include <trace/events/ext4.h>
21 #ifdef CONFIG_EXT4_DEBUG
22 ushort ext4_mballoc_debug __read_mostly;
24 module_param_named(mballoc_debug, ext4_mballoc_debug, ushort, 0644);
25 MODULE_PARM_DESC(mballoc_debug, "Debugging level for ext4's mballoc");
26 #endif
29 * MUSTDO:
30 * - test ext4_ext_search_left() and ext4_ext_search_right()
31 * - search for metadata in few groups
33 * TODO v4:
34 * - normalization should take into account whether file is still open
35 * - discard preallocations if no free space left (policy?)
36 * - don't normalize tails
37 * - quota
38 * - reservation for superuser
40 * TODO v3:
41 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
42 * - track min/max extents in each group for better group selection
43 * - mb_mark_used() may allocate chunk right after splitting buddy
44 * - tree of groups sorted by number of free blocks
45 * - error handling
49 * The allocation request involve request for multiple number of blocks
50 * near to the goal(block) value specified.
52 * During initialization phase of the allocator we decide to use the
53 * group preallocation or inode preallocation depending on the size of
54 * the file. The size of the file could be the resulting file size we
55 * would have after allocation, or the current file size, which ever
56 * is larger. If the size is less than sbi->s_mb_stream_request we
57 * select to use the group preallocation. The default value of
58 * s_mb_stream_request is 16 blocks. This can also be tuned via
59 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
60 * terms of number of blocks.
62 * The main motivation for having small file use group preallocation is to
63 * ensure that we have small files closer together on the disk.
65 * First stage the allocator looks at the inode prealloc list,
66 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
67 * spaces for this particular inode. The inode prealloc space is
68 * represented as:
70 * pa_lstart -> the logical start block for this prealloc space
71 * pa_pstart -> the physical start block for this prealloc space
72 * pa_len -> length for this prealloc space (in clusters)
73 * pa_free -> free space available in this prealloc space (in clusters)
75 * The inode preallocation space is used looking at the _logical_ start
76 * block. If only the logical file block falls within the range of prealloc
77 * space we will consume the particular prealloc space. This makes sure that
78 * we have contiguous physical blocks representing the file blocks
80 * The important thing to be noted in case of inode prealloc space is that
81 * we don't modify the values associated to inode prealloc space except
82 * pa_free.
84 * If we are not able to find blocks in the inode prealloc space and if we
85 * have the group allocation flag set then we look at the locality group
86 * prealloc space. These are per CPU prealloc list represented as
88 * ext4_sb_info.s_locality_groups[smp_processor_id()]
90 * The reason for having a per cpu locality group is to reduce the contention
91 * between CPUs. It is possible to get scheduled at this point.
93 * The locality group prealloc space is used looking at whether we have
94 * enough free space (pa_free) within the prealloc space.
96 * If we can't allocate blocks via inode prealloc or/and locality group
97 * prealloc then we look at the buddy cache. The buddy cache is represented
98 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
99 * mapped to the buddy and bitmap information regarding different
100 * groups. The buddy information is attached to buddy cache inode so that
101 * we can access them through the page cache. The information regarding
102 * each group is loaded via ext4_mb_load_buddy. The information involve
103 * block bitmap and buddy information. The information are stored in the
104 * inode as:
106 * { page }
107 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
110 * one block each for bitmap and buddy information. So for each group we
111 * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
112 * blocksize) blocks. So it can have information regarding groups_per_page
113 * which is blocks_per_page/2
115 * The buddy cache inode is not stored on disk. The inode is thrown
116 * away when the filesystem is unmounted.
118 * We look for count number of blocks in the buddy cache. If we were able
119 * to locate that many free blocks we return with additional information
120 * regarding rest of the contiguous physical block available
122 * Before allocating blocks via buddy cache we normalize the request
123 * blocks. This ensure we ask for more blocks that we needed. The extra
124 * blocks that we get after allocation is added to the respective prealloc
125 * list. In case of inode preallocation we follow a list of heuristics
126 * based on file size. This can be found in ext4_mb_normalize_request. If
127 * we are doing a group prealloc we try to normalize the request to
128 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
129 * dependent on the cluster size; for non-bigalloc file systems, it is
130 * 512 blocks. This can be tuned via
131 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
132 * terms of number of blocks. If we have mounted the file system with -O
133 * stripe=<value> option the group prealloc request is normalized to the
134 * the smallest multiple of the stripe value (sbi->s_stripe) which is
135 * greater than the default mb_group_prealloc.
137 * The regular allocator (using the buddy cache) supports a few tunables.
139 * /sys/fs/ext4/<partition>/mb_min_to_scan
140 * /sys/fs/ext4/<partition>/mb_max_to_scan
141 * /sys/fs/ext4/<partition>/mb_order2_req
143 * The regular allocator uses buddy scan only if the request len is power of
144 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
145 * value of s_mb_order2_reqs can be tuned via
146 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
147 * stripe size (sbi->s_stripe), we try to search for contiguous block in
148 * stripe size. This should result in better allocation on RAID setups. If
149 * not, we search in the specific group using bitmap for best extents. The
150 * tunable min_to_scan and max_to_scan control the behaviour here.
151 * min_to_scan indicate how long the mballoc __must__ look for a best
152 * extent and max_to_scan indicates how long the mballoc __can__ look for a
153 * best extent in the found extents. Searching for the blocks starts with
154 * the group specified as the goal value in allocation context via
155 * ac_g_ex. Each group is first checked based on the criteria whether it
156 * can be used for allocation. ext4_mb_good_group explains how the groups are
157 * checked.
159 * Both the prealloc space are getting populated as above. So for the first
160 * request we will hit the buddy cache which will result in this prealloc
161 * space getting filled. The prealloc space is then later used for the
162 * subsequent request.
166 * mballoc operates on the following data:
167 * - on-disk bitmap
168 * - in-core buddy (actually includes buddy and bitmap)
169 * - preallocation descriptors (PAs)
171 * there are two types of preallocations:
172 * - inode
173 * assiged to specific inode and can be used for this inode only.
174 * it describes part of inode's space preallocated to specific
175 * physical blocks. any block from that preallocated can be used
176 * independent. the descriptor just tracks number of blocks left
177 * unused. so, before taking some block from descriptor, one must
178 * make sure corresponded logical block isn't allocated yet. this
179 * also means that freeing any block within descriptor's range
180 * must discard all preallocated blocks.
181 * - locality group
182 * assigned to specific locality group which does not translate to
183 * permanent set of inodes: inode can join and leave group. space
184 * from this type of preallocation can be used for any inode. thus
185 * it's consumed from the beginning to the end.
187 * relation between them can be expressed as:
188 * in-core buddy = on-disk bitmap + preallocation descriptors
190 * this mean blocks mballoc considers used are:
191 * - allocated blocks (persistent)
192 * - preallocated blocks (non-persistent)
194 * consistency in mballoc world means that at any time a block is either
195 * free or used in ALL structures. notice: "any time" should not be read
196 * literally -- time is discrete and delimited by locks.
198 * to keep it simple, we don't use block numbers, instead we count number of
199 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
201 * all operations can be expressed as:
202 * - init buddy: buddy = on-disk + PAs
203 * - new PA: buddy += N; PA = N
204 * - use inode PA: on-disk += N; PA -= N
205 * - discard inode PA buddy -= on-disk - PA; PA = 0
206 * - use locality group PA on-disk += N; PA -= N
207 * - discard locality group PA buddy -= PA; PA = 0
208 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
209 * is used in real operation because we can't know actual used
210 * bits from PA, only from on-disk bitmap
212 * if we follow this strict logic, then all operations above should be atomic.
213 * given some of them can block, we'd have to use something like semaphores
214 * killing performance on high-end SMP hardware. let's try to relax it using
215 * the following knowledge:
216 * 1) if buddy is referenced, it's already initialized
217 * 2) while block is used in buddy and the buddy is referenced,
218 * nobody can re-allocate that block
219 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
220 * bit set and PA claims same block, it's OK. IOW, one can set bit in
221 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
222 * block
224 * so, now we're building a concurrency table:
225 * - init buddy vs.
226 * - new PA
227 * blocks for PA are allocated in the buddy, buddy must be referenced
228 * until PA is linked to allocation group to avoid concurrent buddy init
229 * - use inode PA
230 * we need to make sure that either on-disk bitmap or PA has uptodate data
231 * given (3) we care that PA-=N operation doesn't interfere with init
232 * - discard inode PA
233 * the simplest way would be to have buddy initialized by the discard
234 * - use locality group PA
235 * again PA-=N must be serialized with init
236 * - discard locality group PA
237 * the simplest way would be to have buddy initialized by the discard
238 * - new PA vs.
239 * - use inode PA
240 * i_data_sem serializes them
241 * - discard inode PA
242 * discard process must wait until PA isn't used by another process
243 * - use locality group PA
244 * some mutex should serialize them
245 * - discard locality group PA
246 * discard process must wait until PA isn't used by another process
247 * - use inode PA
248 * - use inode PA
249 * i_data_sem or another mutex should serializes them
250 * - discard inode PA
251 * discard process must wait until PA isn't used by another process
252 * - use locality group PA
253 * nothing wrong here -- they're different PAs covering different blocks
254 * - discard locality group PA
255 * discard process must wait until PA isn't used by another process
257 * now we're ready to make few consequences:
258 * - PA is referenced and while it is no discard is possible
259 * - PA is referenced until block isn't marked in on-disk bitmap
260 * - PA changes only after on-disk bitmap
261 * - discard must not compete with init. either init is done before
262 * any discard or they're serialized somehow
263 * - buddy init as sum of on-disk bitmap and PAs is done atomically
265 * a special case when we've used PA to emptiness. no need to modify buddy
266 * in this case, but we should care about concurrent init
271 * Logic in few words:
273 * - allocation:
274 * load group
275 * find blocks
276 * mark bits in on-disk bitmap
277 * release group
279 * - use preallocation:
280 * find proper PA (per-inode or group)
281 * load group
282 * mark bits in on-disk bitmap
283 * release group
284 * release PA
286 * - free:
287 * load group
288 * mark bits in on-disk bitmap
289 * release group
291 * - discard preallocations in group:
292 * mark PAs deleted
293 * move them onto local list
294 * load on-disk bitmap
295 * load group
296 * remove PA from object (inode or locality group)
297 * mark free blocks in-core
299 * - discard inode's preallocations:
303 * Locking rules
305 * Locks:
306 * - bitlock on a group (group)
307 * - object (inode/locality) (object)
308 * - per-pa lock (pa)
310 * Paths:
311 * - new pa
312 * object
313 * group
315 * - find and use pa:
316 * pa
318 * - release consumed pa:
319 * pa
320 * group
321 * object
323 * - generate in-core bitmap:
324 * group
325 * pa
327 * - discard all for given object (inode, locality group):
328 * object
329 * pa
330 * group
332 * - discard all for given group:
333 * group
334 * pa
335 * group
336 * object
339 static struct kmem_cache *ext4_pspace_cachep;
340 static struct kmem_cache *ext4_ac_cachep;
341 static struct kmem_cache *ext4_free_data_cachep;
343 /* We create slab caches for groupinfo data structures based on the
344 * superblock block size. There will be one per mounted filesystem for
345 * each unique s_blocksize_bits */
346 #define NR_GRPINFO_CACHES 8
347 static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
349 static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
350 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
351 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
352 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
355 static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
356 ext4_group_t group);
357 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
358 ext4_group_t group);
360 static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
362 #if BITS_PER_LONG == 64
363 *bit += ((unsigned long) addr & 7UL) << 3;
364 addr = (void *) ((unsigned long) addr & ~7UL);
365 #elif BITS_PER_LONG == 32
366 *bit += ((unsigned long) addr & 3UL) << 3;
367 addr = (void *) ((unsigned long) addr & ~3UL);
368 #else
369 #error "how many bits you are?!"
370 #endif
371 return addr;
374 static inline int mb_test_bit(int bit, void *addr)
377 * ext4_test_bit on architecture like powerpc
378 * needs unsigned long aligned address
380 addr = mb_correct_addr_and_bit(&bit, addr);
381 return ext4_test_bit(bit, addr);
384 static inline void mb_set_bit(int bit, void *addr)
386 addr = mb_correct_addr_and_bit(&bit, addr);
387 ext4_set_bit(bit, addr);
390 static inline void mb_clear_bit(int bit, void *addr)
392 addr = mb_correct_addr_and_bit(&bit, addr);
393 ext4_clear_bit(bit, addr);
396 static inline int mb_test_and_clear_bit(int bit, void *addr)
398 addr = mb_correct_addr_and_bit(&bit, addr);
399 return ext4_test_and_clear_bit(bit, addr);
402 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
404 int fix = 0, ret, tmpmax;
405 addr = mb_correct_addr_and_bit(&fix, addr);
406 tmpmax = max + fix;
407 start += fix;
409 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
410 if (ret > max)
411 return max;
412 return ret;
415 static inline int mb_find_next_bit(void *addr, int max, int start)
417 int fix = 0, ret, tmpmax;
418 addr = mb_correct_addr_and_bit(&fix, addr);
419 tmpmax = max + fix;
420 start += fix;
422 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
423 if (ret > max)
424 return max;
425 return ret;
428 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
430 char *bb;
432 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
433 BUG_ON(max == NULL);
435 if (order > e4b->bd_blkbits + 1) {
436 *max = 0;
437 return NULL;
440 /* at order 0 we see each particular block */
441 if (order == 0) {
442 *max = 1 << (e4b->bd_blkbits + 3);
443 return e4b->bd_bitmap;
446 bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
447 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
449 return bb;
452 #ifdef DOUBLE_CHECK
453 static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
454 int first, int count)
456 int i;
457 struct super_block *sb = e4b->bd_sb;
459 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
460 return;
461 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
462 for (i = 0; i < count; i++) {
463 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
464 ext4_fsblk_t blocknr;
466 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
467 blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
468 ext4_grp_locked_error(sb, e4b->bd_group,
469 inode ? inode->i_ino : 0,
470 blocknr,
471 "freeing block already freed "
472 "(bit %u)",
473 first + i);
474 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
475 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
477 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
481 static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
483 int i;
485 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
486 return;
487 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
488 for (i = 0; i < count; i++) {
489 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
490 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
494 static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
496 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
497 unsigned char *b1, *b2;
498 int i;
499 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
500 b2 = (unsigned char *) bitmap;
501 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
502 if (b1[i] != b2[i]) {
503 ext4_msg(e4b->bd_sb, KERN_ERR,
504 "corruption in group %u "
505 "at byte %u(%u): %x in copy != %x "
506 "on disk/prealloc",
507 e4b->bd_group, i, i * 8, b1[i], b2[i]);
508 BUG();
514 #else
515 static inline void mb_free_blocks_double(struct inode *inode,
516 struct ext4_buddy *e4b, int first, int count)
518 return;
520 static inline void mb_mark_used_double(struct ext4_buddy *e4b,
521 int first, int count)
523 return;
525 static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
527 return;
529 #endif
531 #ifdef AGGRESSIVE_CHECK
533 #define MB_CHECK_ASSERT(assert) \
534 do { \
535 if (!(assert)) { \
536 printk(KERN_EMERG \
537 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
538 function, file, line, # assert); \
539 BUG(); \
541 } while (0)
543 static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
544 const char *function, int line)
546 struct super_block *sb = e4b->bd_sb;
547 int order = e4b->bd_blkbits + 1;
548 int max;
549 int max2;
550 int i;
551 int j;
552 int k;
553 int count;
554 struct ext4_group_info *grp;
555 int fragments = 0;
556 int fstart;
557 struct list_head *cur;
558 void *buddy;
559 void *buddy2;
562 static int mb_check_counter;
563 if (mb_check_counter++ % 100 != 0)
564 return 0;
567 while (order > 1) {
568 buddy = mb_find_buddy(e4b, order, &max);
569 MB_CHECK_ASSERT(buddy);
570 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
571 MB_CHECK_ASSERT(buddy2);
572 MB_CHECK_ASSERT(buddy != buddy2);
573 MB_CHECK_ASSERT(max * 2 == max2);
575 count = 0;
576 for (i = 0; i < max; i++) {
578 if (mb_test_bit(i, buddy)) {
579 /* only single bit in buddy2 may be 1 */
580 if (!mb_test_bit(i << 1, buddy2)) {
581 MB_CHECK_ASSERT(
582 mb_test_bit((i<<1)+1, buddy2));
583 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
584 MB_CHECK_ASSERT(
585 mb_test_bit(i << 1, buddy2));
587 continue;
590 /* both bits in buddy2 must be 1 */
591 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
592 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
594 for (j = 0; j < (1 << order); j++) {
595 k = (i * (1 << order)) + j;
596 MB_CHECK_ASSERT(
597 !mb_test_bit(k, e4b->bd_bitmap));
599 count++;
601 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
602 order--;
605 fstart = -1;
606 buddy = mb_find_buddy(e4b, 0, &max);
607 for (i = 0; i < max; i++) {
608 if (!mb_test_bit(i, buddy)) {
609 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
610 if (fstart == -1) {
611 fragments++;
612 fstart = i;
614 continue;
616 fstart = -1;
617 /* check used bits only */
618 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
619 buddy2 = mb_find_buddy(e4b, j, &max2);
620 k = i >> j;
621 MB_CHECK_ASSERT(k < max2);
622 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
625 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
626 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
628 grp = ext4_get_group_info(sb, e4b->bd_group);
629 list_for_each(cur, &grp->bb_prealloc_list) {
630 ext4_group_t groupnr;
631 struct ext4_prealloc_space *pa;
632 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
633 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
634 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
635 for (i = 0; i < pa->pa_len; i++)
636 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
638 return 0;
640 #undef MB_CHECK_ASSERT
641 #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
642 __FILE__, __func__, __LINE__)
643 #else
644 #define mb_check_buddy(e4b)
645 #endif
648 * Divide blocks started from @first with length @len into
649 * smaller chunks with power of 2 blocks.
650 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
651 * then increase bb_counters[] for corresponded chunk size.
653 static void ext4_mb_mark_free_simple(struct super_block *sb,
654 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
655 struct ext4_group_info *grp)
657 struct ext4_sb_info *sbi = EXT4_SB(sb);
658 ext4_grpblk_t min;
659 ext4_grpblk_t max;
660 ext4_grpblk_t chunk;
661 unsigned int border;
663 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
665 border = 2 << sb->s_blocksize_bits;
667 while (len > 0) {
668 /* find how many blocks can be covered since this position */
669 max = ffs(first | border) - 1;
671 /* find how many blocks of power 2 we need to mark */
672 min = fls(len) - 1;
674 if (max < min)
675 min = max;
676 chunk = 1 << min;
678 /* mark multiblock chunks only */
679 grp->bb_counters[min]++;
680 if (min > 0)
681 mb_clear_bit(first >> min,
682 buddy + sbi->s_mb_offsets[min]);
684 len -= chunk;
685 first += chunk;
690 * Cache the order of the largest free extent we have available in this block
691 * group.
693 static void
694 mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
696 int i;
697 int bits;
699 grp->bb_largest_free_order = -1; /* uninit */
701 bits = sb->s_blocksize_bits + 1;
702 for (i = bits; i >= 0; i--) {
703 if (grp->bb_counters[i] > 0) {
704 grp->bb_largest_free_order = i;
705 break;
710 static noinline_for_stack
711 void ext4_mb_generate_buddy(struct super_block *sb,
712 void *buddy, void *bitmap, ext4_group_t group)
714 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
715 struct ext4_sb_info *sbi = EXT4_SB(sb);
716 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
717 ext4_grpblk_t i = 0;
718 ext4_grpblk_t first;
719 ext4_grpblk_t len;
720 unsigned free = 0;
721 unsigned fragments = 0;
722 unsigned long long period = get_cycles();
724 /* initialize buddy from bitmap which is aggregation
725 * of on-disk bitmap and preallocations */
726 i = mb_find_next_zero_bit(bitmap, max, 0);
727 grp->bb_first_free = i;
728 while (i < max) {
729 fragments++;
730 first = i;
731 i = mb_find_next_bit(bitmap, max, i);
732 len = i - first;
733 free += len;
734 if (len > 1)
735 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
736 else
737 grp->bb_counters[0]++;
738 if (i < max)
739 i = mb_find_next_zero_bit(bitmap, max, i);
741 grp->bb_fragments = fragments;
743 if (free != grp->bb_free) {
744 ext4_grp_locked_error(sb, group, 0, 0,
745 "block bitmap and bg descriptor "
746 "inconsistent: %u vs %u free clusters",
747 free, grp->bb_free);
749 * If we intend to continue, we consider group descriptor
750 * corrupt and update bb_free using bitmap value
752 grp->bb_free = free;
753 ext4_mark_group_bitmap_corrupted(sb, group,
754 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
756 mb_set_largest_free_order(sb, grp);
758 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
760 period = get_cycles() - period;
761 spin_lock(&sbi->s_bal_lock);
762 sbi->s_mb_buddies_generated++;
763 sbi->s_mb_generation_time += period;
764 spin_unlock(&sbi->s_bal_lock);
767 static void mb_regenerate_buddy(struct ext4_buddy *e4b)
769 int count;
770 int order = 1;
771 void *buddy;
773 while ((buddy = mb_find_buddy(e4b, order++, &count))) {
774 ext4_set_bits(buddy, 0, count);
776 e4b->bd_info->bb_fragments = 0;
777 memset(e4b->bd_info->bb_counters, 0,
778 sizeof(*e4b->bd_info->bb_counters) *
779 (e4b->bd_sb->s_blocksize_bits + 2));
781 ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy,
782 e4b->bd_bitmap, e4b->bd_group);
785 /* The buddy information is attached the buddy cache inode
786 * for convenience. The information regarding each group
787 * is loaded via ext4_mb_load_buddy. The information involve
788 * block bitmap and buddy information. The information are
789 * stored in the inode as
791 * { page }
792 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
795 * one block each for bitmap and buddy information.
796 * So for each group we take up 2 blocks. A page can
797 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
798 * So it can have information regarding groups_per_page which
799 * is blocks_per_page/2
801 * Locking note: This routine takes the block group lock of all groups
802 * for this page; do not hold this lock when calling this routine!
805 static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
807 ext4_group_t ngroups;
808 int blocksize;
809 int blocks_per_page;
810 int groups_per_page;
811 int err = 0;
812 int i;
813 ext4_group_t first_group, group;
814 int first_block;
815 struct super_block *sb;
816 struct buffer_head *bhs;
817 struct buffer_head **bh = NULL;
818 struct inode *inode;
819 char *data;
820 char *bitmap;
821 struct ext4_group_info *grinfo;
823 mb_debug(1, "init page %lu\n", page->index);
825 inode = page->mapping->host;
826 sb = inode->i_sb;
827 ngroups = ext4_get_groups_count(sb);
828 blocksize = i_blocksize(inode);
829 blocks_per_page = PAGE_SIZE / blocksize;
831 groups_per_page = blocks_per_page >> 1;
832 if (groups_per_page == 0)
833 groups_per_page = 1;
835 /* allocate buffer_heads to read bitmaps */
836 if (groups_per_page > 1) {
837 i = sizeof(struct buffer_head *) * groups_per_page;
838 bh = kzalloc(i, gfp);
839 if (bh == NULL) {
840 err = -ENOMEM;
841 goto out;
843 } else
844 bh = &bhs;
846 first_group = page->index * blocks_per_page / 2;
848 /* read all groups the page covers into the cache */
849 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
850 if (group >= ngroups)
851 break;
853 grinfo = ext4_get_group_info(sb, group);
855 * If page is uptodate then we came here after online resize
856 * which added some new uninitialized group info structs, so
857 * we must skip all initialized uptodate buddies on the page,
858 * which may be currently in use by an allocating task.
860 if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) {
861 bh[i] = NULL;
862 continue;
864 bh[i] = ext4_read_block_bitmap_nowait(sb, group);
865 if (IS_ERR(bh[i])) {
866 err = PTR_ERR(bh[i]);
867 bh[i] = NULL;
868 goto out;
870 mb_debug(1, "read bitmap for group %u\n", group);
873 /* wait for I/O completion */
874 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
875 int err2;
877 if (!bh[i])
878 continue;
879 err2 = ext4_wait_block_bitmap(sb, group, bh[i]);
880 if (!err)
881 err = err2;
884 first_block = page->index * blocks_per_page;
885 for (i = 0; i < blocks_per_page; i++) {
886 group = (first_block + i) >> 1;
887 if (group >= ngroups)
888 break;
890 if (!bh[group - first_group])
891 /* skip initialized uptodate buddy */
892 continue;
894 if (!buffer_verified(bh[group - first_group]))
895 /* Skip faulty bitmaps */
896 continue;
897 err = 0;
900 * data carry information regarding this
901 * particular group in the format specified
902 * above
905 data = page_address(page) + (i * blocksize);
906 bitmap = bh[group - first_group]->b_data;
909 * We place the buddy block and bitmap block
910 * close together
912 if ((first_block + i) & 1) {
913 /* this is block of buddy */
914 BUG_ON(incore == NULL);
915 mb_debug(1, "put buddy for group %u in page %lu/%x\n",
916 group, page->index, i * blocksize);
917 trace_ext4_mb_buddy_bitmap_load(sb, group);
918 grinfo = ext4_get_group_info(sb, group);
919 grinfo->bb_fragments = 0;
920 memset(grinfo->bb_counters, 0,
921 sizeof(*grinfo->bb_counters) *
922 (sb->s_blocksize_bits+2));
924 * incore got set to the group block bitmap below
926 ext4_lock_group(sb, group);
927 /* init the buddy */
928 memset(data, 0xff, blocksize);
929 ext4_mb_generate_buddy(sb, data, incore, group);
930 ext4_unlock_group(sb, group);
931 incore = NULL;
932 } else {
933 /* this is block of bitmap */
934 BUG_ON(incore != NULL);
935 mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
936 group, page->index, i * blocksize);
937 trace_ext4_mb_bitmap_load(sb, group);
939 /* see comments in ext4_mb_put_pa() */
940 ext4_lock_group(sb, group);
941 memcpy(data, bitmap, blocksize);
943 /* mark all preallocated blks used in in-core bitmap */
944 ext4_mb_generate_from_pa(sb, data, group);
945 ext4_mb_generate_from_freelist(sb, data, group);
946 ext4_unlock_group(sb, group);
948 /* set incore so that the buddy information can be
949 * generated using this
951 incore = data;
954 SetPageUptodate(page);
956 out:
957 if (bh) {
958 for (i = 0; i < groups_per_page; i++)
959 brelse(bh[i]);
960 if (bh != &bhs)
961 kfree(bh);
963 return err;
967 * Lock the buddy and bitmap pages. This make sure other parallel init_group
968 * on the same buddy page doesn't happen whild holding the buddy page lock.
969 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
970 * are on the same page e4b->bd_buddy_page is NULL and return value is 0.
972 static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
973 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
975 struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
976 int block, pnum, poff;
977 int blocks_per_page;
978 struct page *page;
980 e4b->bd_buddy_page = NULL;
981 e4b->bd_bitmap_page = NULL;
983 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
985 * the buddy cache inode stores the block bitmap
986 * and buddy information in consecutive blocks.
987 * So for each group we need two blocks.
989 block = group * 2;
990 pnum = block / blocks_per_page;
991 poff = block % blocks_per_page;
992 page = find_or_create_page(inode->i_mapping, pnum, gfp);
993 if (!page)
994 return -ENOMEM;
995 BUG_ON(page->mapping != inode->i_mapping);
996 e4b->bd_bitmap_page = page;
997 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
999 if (blocks_per_page >= 2) {
1000 /* buddy and bitmap are on the same page */
1001 return 0;
1004 block++;
1005 pnum = block / blocks_per_page;
1006 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1007 if (!page)
1008 return -ENOMEM;
1009 BUG_ON(page->mapping != inode->i_mapping);
1010 e4b->bd_buddy_page = page;
1011 return 0;
1014 static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1016 if (e4b->bd_bitmap_page) {
1017 unlock_page(e4b->bd_bitmap_page);
1018 put_page(e4b->bd_bitmap_page);
1020 if (e4b->bd_buddy_page) {
1021 unlock_page(e4b->bd_buddy_page);
1022 put_page(e4b->bd_buddy_page);
1027 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1028 * block group lock of all groups for this page; do not hold the BG lock when
1029 * calling this routine!
1031 static noinline_for_stack
1032 int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1035 struct ext4_group_info *this_grp;
1036 struct ext4_buddy e4b;
1037 struct page *page;
1038 int ret = 0;
1040 might_sleep();
1041 mb_debug(1, "init group %u\n", group);
1042 this_grp = ext4_get_group_info(sb, group);
1044 * This ensures that we don't reinit the buddy cache
1045 * page which map to the group from which we are already
1046 * allocating. If we are looking at the buddy cache we would
1047 * have taken a reference using ext4_mb_load_buddy and that
1048 * would have pinned buddy page to page cache.
1049 * The call to ext4_mb_get_buddy_page_lock will mark the
1050 * page accessed.
1052 ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp);
1053 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1055 * somebody initialized the group
1056 * return without doing anything
1058 goto err;
1061 page = e4b.bd_bitmap_page;
1062 ret = ext4_mb_init_cache(page, NULL, gfp);
1063 if (ret)
1064 goto err;
1065 if (!PageUptodate(page)) {
1066 ret = -EIO;
1067 goto err;
1070 if (e4b.bd_buddy_page == NULL) {
1072 * If both the bitmap and buddy are in
1073 * the same page we don't need to force
1074 * init the buddy
1076 ret = 0;
1077 goto err;
1079 /* init buddy cache */
1080 page = e4b.bd_buddy_page;
1081 ret = ext4_mb_init_cache(page, e4b.bd_bitmap, gfp);
1082 if (ret)
1083 goto err;
1084 if (!PageUptodate(page)) {
1085 ret = -EIO;
1086 goto err;
1088 err:
1089 ext4_mb_put_buddy_page_lock(&e4b);
1090 return ret;
1094 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1095 * block group lock of all groups for this page; do not hold the BG lock when
1096 * calling this routine!
1098 static noinline_for_stack int
1099 ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1100 struct ext4_buddy *e4b, gfp_t gfp)
1102 int blocks_per_page;
1103 int block;
1104 int pnum;
1105 int poff;
1106 struct page *page;
1107 int ret;
1108 struct ext4_group_info *grp;
1109 struct ext4_sb_info *sbi = EXT4_SB(sb);
1110 struct inode *inode = sbi->s_buddy_cache;
1112 might_sleep();
1113 mb_debug(1, "load group %u\n", group);
1115 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1116 grp = ext4_get_group_info(sb, group);
1118 e4b->bd_blkbits = sb->s_blocksize_bits;
1119 e4b->bd_info = grp;
1120 e4b->bd_sb = sb;
1121 e4b->bd_group = group;
1122 e4b->bd_buddy_page = NULL;
1123 e4b->bd_bitmap_page = NULL;
1125 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1127 * we need full data about the group
1128 * to make a good selection
1130 ret = ext4_mb_init_group(sb, group, gfp);
1131 if (ret)
1132 return ret;
1136 * the buddy cache inode stores the block bitmap
1137 * and buddy information in consecutive blocks.
1138 * So for each group we need two blocks.
1140 block = group * 2;
1141 pnum = block / blocks_per_page;
1142 poff = block % blocks_per_page;
1144 /* we could use find_or_create_page(), but it locks page
1145 * what we'd like to avoid in fast path ... */
1146 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1147 if (page == NULL || !PageUptodate(page)) {
1148 if (page)
1150 * drop the page reference and try
1151 * to get the page with lock. If we
1152 * are not uptodate that implies
1153 * somebody just created the page but
1154 * is yet to initialize the same. So
1155 * wait for it to initialize.
1157 put_page(page);
1158 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1159 if (page) {
1160 BUG_ON(page->mapping != inode->i_mapping);
1161 if (!PageUptodate(page)) {
1162 ret = ext4_mb_init_cache(page, NULL, gfp);
1163 if (ret) {
1164 unlock_page(page);
1165 goto err;
1167 mb_cmp_bitmaps(e4b, page_address(page) +
1168 (poff * sb->s_blocksize));
1170 unlock_page(page);
1173 if (page == NULL) {
1174 ret = -ENOMEM;
1175 goto err;
1177 if (!PageUptodate(page)) {
1178 ret = -EIO;
1179 goto err;
1182 /* Pages marked accessed already */
1183 e4b->bd_bitmap_page = page;
1184 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1186 block++;
1187 pnum = block / blocks_per_page;
1188 poff = block % blocks_per_page;
1190 page = find_get_page_flags(inode->i_mapping, pnum, FGP_ACCESSED);
1191 if (page == NULL || !PageUptodate(page)) {
1192 if (page)
1193 put_page(page);
1194 page = find_or_create_page(inode->i_mapping, pnum, gfp);
1195 if (page) {
1196 BUG_ON(page->mapping != inode->i_mapping);
1197 if (!PageUptodate(page)) {
1198 ret = ext4_mb_init_cache(page, e4b->bd_bitmap,
1199 gfp);
1200 if (ret) {
1201 unlock_page(page);
1202 goto err;
1205 unlock_page(page);
1208 if (page == NULL) {
1209 ret = -ENOMEM;
1210 goto err;
1212 if (!PageUptodate(page)) {
1213 ret = -EIO;
1214 goto err;
1217 /* Pages marked accessed already */
1218 e4b->bd_buddy_page = page;
1219 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1221 BUG_ON(e4b->bd_bitmap_page == NULL);
1222 BUG_ON(e4b->bd_buddy_page == NULL);
1224 return 0;
1226 err:
1227 if (page)
1228 put_page(page);
1229 if (e4b->bd_bitmap_page)
1230 put_page(e4b->bd_bitmap_page);
1231 if (e4b->bd_buddy_page)
1232 put_page(e4b->bd_buddy_page);
1233 e4b->bd_buddy = NULL;
1234 e4b->bd_bitmap = NULL;
1235 return ret;
1238 static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1239 struct ext4_buddy *e4b)
1241 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1244 static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1246 if (e4b->bd_bitmap_page)
1247 put_page(e4b->bd_bitmap_page);
1248 if (e4b->bd_buddy_page)
1249 put_page(e4b->bd_buddy_page);
1253 static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1255 int order = 1;
1256 int bb_incr = 1 << (e4b->bd_blkbits - 1);
1257 void *bb;
1259 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1260 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1262 bb = e4b->bd_buddy;
1263 while (order <= e4b->bd_blkbits + 1) {
1264 block = block >> 1;
1265 if (!mb_test_bit(block, bb)) {
1266 /* this block is part of buddy of order 'order' */
1267 return order;
1269 bb += bb_incr;
1270 bb_incr >>= 1;
1271 order++;
1273 return 0;
1276 static void mb_clear_bits(void *bm, int cur, int len)
1278 __u32 *addr;
1280 len = cur + len;
1281 while (cur < len) {
1282 if ((cur & 31) == 0 && (len - cur) >= 32) {
1283 /* fast path: clear whole word at once */
1284 addr = bm + (cur >> 3);
1285 *addr = 0;
1286 cur += 32;
1287 continue;
1289 mb_clear_bit(cur, bm);
1290 cur++;
1294 /* clear bits in given range
1295 * will return first found zero bit if any, -1 otherwise
1297 static int mb_test_and_clear_bits(void *bm, int cur, int len)
1299 __u32 *addr;
1300 int zero_bit = -1;
1302 len = cur + len;
1303 while (cur < len) {
1304 if ((cur & 31) == 0 && (len - cur) >= 32) {
1305 /* fast path: clear whole word at once */
1306 addr = bm + (cur >> 3);
1307 if (*addr != (__u32)(-1) && zero_bit == -1)
1308 zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0);
1309 *addr = 0;
1310 cur += 32;
1311 continue;
1313 if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1)
1314 zero_bit = cur;
1315 cur++;
1318 return zero_bit;
1321 void ext4_set_bits(void *bm, int cur, int len)
1323 __u32 *addr;
1325 len = cur + len;
1326 while (cur < len) {
1327 if ((cur & 31) == 0 && (len - cur) >= 32) {
1328 /* fast path: set whole word at once */
1329 addr = bm + (cur >> 3);
1330 *addr = 0xffffffff;
1331 cur += 32;
1332 continue;
1334 mb_set_bit(cur, bm);
1335 cur++;
1340 * _________________________________________________________________ */
1342 static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1344 if (mb_test_bit(*bit + side, bitmap)) {
1345 mb_clear_bit(*bit, bitmap);
1346 (*bit) -= side;
1347 return 1;
1349 else {
1350 (*bit) += side;
1351 mb_set_bit(*bit, bitmap);
1352 return -1;
1356 static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1358 int max;
1359 int order = 1;
1360 void *buddy = mb_find_buddy(e4b, order, &max);
1362 while (buddy) {
1363 void *buddy2;
1365 /* Bits in range [first; last] are known to be set since
1366 * corresponding blocks were allocated. Bits in range
1367 * (first; last) will stay set because they form buddies on
1368 * upper layer. We just deal with borders if they don't
1369 * align with upper layer and then go up.
1370 * Releasing entire group is all about clearing
1371 * single bit of highest order buddy.
1374 /* Example:
1375 * ---------------------------------
1376 * | 1 | 1 | 1 | 1 |
1377 * ---------------------------------
1378 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1379 * ---------------------------------
1380 * 0 1 2 3 4 5 6 7
1381 * \_____________________/
1383 * Neither [1] nor [6] is aligned to above layer.
1384 * Left neighbour [0] is free, so mark it busy,
1385 * decrease bb_counters and extend range to
1386 * [0; 6]
1387 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1388 * mark [6] free, increase bb_counters and shrink range to
1389 * [0; 5].
1390 * Then shift range to [0; 2], go up and do the same.
1394 if (first & 1)
1395 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1);
1396 if (!(last & 1))
1397 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1);
1398 if (first > last)
1399 break;
1400 order++;
1402 if (first == last || !(buddy2 = mb_find_buddy(e4b, order, &max))) {
1403 mb_clear_bits(buddy, first, last - first + 1);
1404 e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1405 break;
1407 first >>= 1;
1408 last >>= 1;
1409 buddy = buddy2;
1413 static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1414 int first, int count)
1416 int left_is_free = 0;
1417 int right_is_free = 0;
1418 int block;
1419 int last = first + count - 1;
1420 struct super_block *sb = e4b->bd_sb;
1422 if (WARN_ON(count == 0))
1423 return;
1424 BUG_ON(last >= (sb->s_blocksize << 3));
1425 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1426 /* Don't bother if the block group is corrupt. */
1427 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1428 return;
1430 mb_check_buddy(e4b);
1431 mb_free_blocks_double(inode, e4b, first, count);
1433 e4b->bd_info->bb_free += count;
1434 if (first < e4b->bd_info->bb_first_free)
1435 e4b->bd_info->bb_first_free = first;
1437 /* access memory sequentially: check left neighbour,
1438 * clear range and then check right neighbour
1440 if (first != 0)
1441 left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap);
1442 block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count);
1443 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1444 right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap);
1446 if (unlikely(block != -1)) {
1447 struct ext4_sb_info *sbi = EXT4_SB(sb);
1448 ext4_fsblk_t blocknr;
1450 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
1451 blocknr += EXT4_C2B(sbi, block);
1452 ext4_grp_locked_error(sb, e4b->bd_group,
1453 inode ? inode->i_ino : 0,
1454 blocknr,
1455 "freeing already freed block "
1456 "(bit %u); block bitmap corrupt.",
1457 block);
1458 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
1459 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1460 mb_regenerate_buddy(e4b);
1461 goto done;
1464 /* let's maintain fragments counter */
1465 if (left_is_free && right_is_free)
1466 e4b->bd_info->bb_fragments--;
1467 else if (!left_is_free && !right_is_free)
1468 e4b->bd_info->bb_fragments++;
1470 /* buddy[0] == bd_bitmap is a special case, so handle
1471 * it right away and let mb_buddy_mark_free stay free of
1472 * zero order checks.
1473 * Check if neighbours are to be coaleasced,
1474 * adjust bitmap bb_counters and borders appropriately.
1476 if (first & 1) {
1477 first += !left_is_free;
1478 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
1480 if (!(last & 1)) {
1481 last -= !right_is_free;
1482 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
1485 if (first <= last)
1486 mb_buddy_mark_free(e4b, first >> 1, last >> 1);
1488 done:
1489 mb_set_largest_free_order(sb, e4b->bd_info);
1490 mb_check_buddy(e4b);
1493 static int mb_find_extent(struct ext4_buddy *e4b, int block,
1494 int needed, struct ext4_free_extent *ex)
1496 int next = block;
1497 int max, order;
1498 void *buddy;
1500 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1501 BUG_ON(ex == NULL);
1503 buddy = mb_find_buddy(e4b, 0, &max);
1504 BUG_ON(buddy == NULL);
1505 BUG_ON(block >= max);
1506 if (mb_test_bit(block, buddy)) {
1507 ex->fe_len = 0;
1508 ex->fe_start = 0;
1509 ex->fe_group = 0;
1510 return 0;
1513 /* find actual order */
1514 order = mb_find_order_for_block(e4b, block);
1515 block = block >> order;
1517 ex->fe_len = 1 << order;
1518 ex->fe_start = block << order;
1519 ex->fe_group = e4b->bd_group;
1521 /* calc difference from given start */
1522 next = next - ex->fe_start;
1523 ex->fe_len -= next;
1524 ex->fe_start += next;
1526 while (needed > ex->fe_len &&
1527 mb_find_buddy(e4b, order, &max)) {
1529 if (block + 1 >= max)
1530 break;
1532 next = (block + 1) * (1 << order);
1533 if (mb_test_bit(next, e4b->bd_bitmap))
1534 break;
1536 order = mb_find_order_for_block(e4b, next);
1538 block = next >> order;
1539 ex->fe_len += 1 << order;
1542 if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
1543 /* Should never happen! (but apparently sometimes does?!?) */
1544 WARN_ON(1);
1545 ext4_error(e4b->bd_sb, "corruption or bug in mb_find_extent "
1546 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
1547 block, order, needed, ex->fe_group, ex->fe_start,
1548 ex->fe_len, ex->fe_logical);
1549 ex->fe_len = 0;
1550 ex->fe_start = 0;
1551 ex->fe_group = 0;
1553 return ex->fe_len;
1556 static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1558 int ord;
1559 int mlen = 0;
1560 int max = 0;
1561 int cur;
1562 int start = ex->fe_start;
1563 int len = ex->fe_len;
1564 unsigned ret = 0;
1565 int len0 = len;
1566 void *buddy;
1568 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1569 BUG_ON(e4b->bd_group != ex->fe_group);
1570 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1571 mb_check_buddy(e4b);
1572 mb_mark_used_double(e4b, start, len);
1574 e4b->bd_info->bb_free -= len;
1575 if (e4b->bd_info->bb_first_free == start)
1576 e4b->bd_info->bb_first_free += len;
1578 /* let's maintain fragments counter */
1579 if (start != 0)
1580 mlen = !mb_test_bit(start - 1, e4b->bd_bitmap);
1581 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1582 max = !mb_test_bit(start + len, e4b->bd_bitmap);
1583 if (mlen && max)
1584 e4b->bd_info->bb_fragments++;
1585 else if (!mlen && !max)
1586 e4b->bd_info->bb_fragments--;
1588 /* let's maintain buddy itself */
1589 while (len) {
1590 ord = mb_find_order_for_block(e4b, start);
1592 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1593 /* the whole chunk may be allocated at once! */
1594 mlen = 1 << ord;
1595 buddy = mb_find_buddy(e4b, ord, &max);
1596 BUG_ON((start >> ord) >= max);
1597 mb_set_bit(start >> ord, buddy);
1598 e4b->bd_info->bb_counters[ord]--;
1599 start += mlen;
1600 len -= mlen;
1601 BUG_ON(len < 0);
1602 continue;
1605 /* store for history */
1606 if (ret == 0)
1607 ret = len | (ord << 16);
1609 /* we have to split large buddy */
1610 BUG_ON(ord <= 0);
1611 buddy = mb_find_buddy(e4b, ord, &max);
1612 mb_set_bit(start >> ord, buddy);
1613 e4b->bd_info->bb_counters[ord]--;
1615 ord--;
1616 cur = (start >> ord) & ~1U;
1617 buddy = mb_find_buddy(e4b, ord, &max);
1618 mb_clear_bit(cur, buddy);
1619 mb_clear_bit(cur + 1, buddy);
1620 e4b->bd_info->bb_counters[ord]++;
1621 e4b->bd_info->bb_counters[ord]++;
1623 mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
1625 ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
1626 mb_check_buddy(e4b);
1628 return ret;
1632 * Must be called under group lock!
1634 static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1635 struct ext4_buddy *e4b)
1637 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1638 int ret;
1640 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1641 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1643 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1644 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1645 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1647 /* preallocation can change ac_b_ex, thus we store actually
1648 * allocated blocks for history */
1649 ac->ac_f_ex = ac->ac_b_ex;
1651 ac->ac_status = AC_STATUS_FOUND;
1652 ac->ac_tail = ret & 0xffff;
1653 ac->ac_buddy = ret >> 16;
1656 * take the page reference. We want the page to be pinned
1657 * so that we don't get a ext4_mb_init_cache_call for this
1658 * group until we update the bitmap. That would mean we
1659 * double allocate blocks. The reference is dropped
1660 * in ext4_mb_release_context
1662 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1663 get_page(ac->ac_bitmap_page);
1664 ac->ac_buddy_page = e4b->bd_buddy_page;
1665 get_page(ac->ac_buddy_page);
1666 /* store last allocated for subsequent stream allocation */
1667 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
1668 spin_lock(&sbi->s_md_lock);
1669 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1670 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1671 spin_unlock(&sbi->s_md_lock);
1676 * regular allocator, for general purposes allocation
1679 static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1680 struct ext4_buddy *e4b,
1681 int finish_group)
1683 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1684 struct ext4_free_extent *bex = &ac->ac_b_ex;
1685 struct ext4_free_extent *gex = &ac->ac_g_ex;
1686 struct ext4_free_extent ex;
1687 int max;
1689 if (ac->ac_status == AC_STATUS_FOUND)
1690 return;
1692 * We don't want to scan for a whole year
1694 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1695 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1696 ac->ac_status = AC_STATUS_BREAK;
1697 return;
1701 * Haven't found good chunk so far, let's continue
1703 if (bex->fe_len < gex->fe_len)
1704 return;
1706 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1707 && bex->fe_group == e4b->bd_group) {
1708 /* recheck chunk's availability - we don't know
1709 * when it was found (within this lock-unlock
1710 * period or not) */
1711 max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex);
1712 if (max >= gex->fe_len) {
1713 ext4_mb_use_best_found(ac, e4b);
1714 return;
1720 * The routine checks whether found extent is good enough. If it is,
1721 * then the extent gets marked used and flag is set to the context
1722 * to stop scanning. Otherwise, the extent is compared with the
1723 * previous found extent and if new one is better, then it's stored
1724 * in the context. Later, the best found extent will be used, if
1725 * mballoc can't find good enough extent.
1727 * FIXME: real allocation policy is to be designed yet!
1729 static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1730 struct ext4_free_extent *ex,
1731 struct ext4_buddy *e4b)
1733 struct ext4_free_extent *bex = &ac->ac_b_ex;
1734 struct ext4_free_extent *gex = &ac->ac_g_ex;
1736 BUG_ON(ex->fe_len <= 0);
1737 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1738 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
1739 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1741 ac->ac_found++;
1744 * The special case - take what you catch first
1746 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1747 *bex = *ex;
1748 ext4_mb_use_best_found(ac, e4b);
1749 return;
1753 * Let's check whether the chuck is good enough
1755 if (ex->fe_len == gex->fe_len) {
1756 *bex = *ex;
1757 ext4_mb_use_best_found(ac, e4b);
1758 return;
1762 * If this is first found extent, just store it in the context
1764 if (bex->fe_len == 0) {
1765 *bex = *ex;
1766 return;
1770 * If new found extent is better, store it in the context
1772 if (bex->fe_len < gex->fe_len) {
1773 /* if the request isn't satisfied, any found extent
1774 * larger than previous best one is better */
1775 if (ex->fe_len > bex->fe_len)
1776 *bex = *ex;
1777 } else if (ex->fe_len > gex->fe_len) {
1778 /* if the request is satisfied, then we try to find
1779 * an extent that still satisfy the request, but is
1780 * smaller than previous one */
1781 if (ex->fe_len < bex->fe_len)
1782 *bex = *ex;
1785 ext4_mb_check_limits(ac, e4b, 0);
1788 static noinline_for_stack
1789 int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1790 struct ext4_buddy *e4b)
1792 struct ext4_free_extent ex = ac->ac_b_ex;
1793 ext4_group_t group = ex.fe_group;
1794 int max;
1795 int err;
1797 BUG_ON(ex.fe_len <= 0);
1798 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1799 if (err)
1800 return err;
1802 ext4_lock_group(ac->ac_sb, group);
1803 max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex);
1805 if (max > 0) {
1806 ac->ac_b_ex = ex;
1807 ext4_mb_use_best_found(ac, e4b);
1810 ext4_unlock_group(ac->ac_sb, group);
1811 ext4_mb_unload_buddy(e4b);
1813 return 0;
1816 static noinline_for_stack
1817 int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1818 struct ext4_buddy *e4b)
1820 ext4_group_t group = ac->ac_g_ex.fe_group;
1821 int max;
1822 int err;
1823 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1824 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1825 struct ext4_free_extent ex;
1827 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1828 return 0;
1829 if (grp->bb_free == 0)
1830 return 0;
1832 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1833 if (err)
1834 return err;
1836 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) {
1837 ext4_mb_unload_buddy(e4b);
1838 return 0;
1841 ext4_lock_group(ac->ac_sb, group);
1842 max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
1843 ac->ac_g_ex.fe_len, &ex);
1844 ex.fe_logical = 0xDEADFA11; /* debug value */
1846 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1847 ext4_fsblk_t start;
1849 start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) +
1850 ex.fe_start;
1851 /* use do_div to get remainder (would be 64-bit modulo) */
1852 if (do_div(start, sbi->s_stripe) == 0) {
1853 ac->ac_found++;
1854 ac->ac_b_ex = ex;
1855 ext4_mb_use_best_found(ac, e4b);
1857 } else if (max >= ac->ac_g_ex.fe_len) {
1858 BUG_ON(ex.fe_len <= 0);
1859 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1860 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1861 ac->ac_found++;
1862 ac->ac_b_ex = ex;
1863 ext4_mb_use_best_found(ac, e4b);
1864 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1865 /* Sometimes, caller may want to merge even small
1866 * number of blocks to an existing extent */
1867 BUG_ON(ex.fe_len <= 0);
1868 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1869 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1870 ac->ac_found++;
1871 ac->ac_b_ex = ex;
1872 ext4_mb_use_best_found(ac, e4b);
1874 ext4_unlock_group(ac->ac_sb, group);
1875 ext4_mb_unload_buddy(e4b);
1877 return 0;
1881 * The routine scans buddy structures (not bitmap!) from given order
1882 * to max order and tries to find big enough chunk to satisfy the req
1884 static noinline_for_stack
1885 void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1886 struct ext4_buddy *e4b)
1888 struct super_block *sb = ac->ac_sb;
1889 struct ext4_group_info *grp = e4b->bd_info;
1890 void *buddy;
1891 int i;
1892 int k;
1893 int max;
1895 BUG_ON(ac->ac_2order <= 0);
1896 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1897 if (grp->bb_counters[i] == 0)
1898 continue;
1900 buddy = mb_find_buddy(e4b, i, &max);
1901 BUG_ON(buddy == NULL);
1903 k = mb_find_next_zero_bit(buddy, max, 0);
1904 BUG_ON(k >= max);
1906 ac->ac_found++;
1908 ac->ac_b_ex.fe_len = 1 << i;
1909 ac->ac_b_ex.fe_start = k << i;
1910 ac->ac_b_ex.fe_group = e4b->bd_group;
1912 ext4_mb_use_best_found(ac, e4b);
1914 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1916 if (EXT4_SB(sb)->s_mb_stats)
1917 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1919 break;
1924 * The routine scans the group and measures all found extents.
1925 * In order to optimize scanning, caller must pass number of
1926 * free blocks in the group, so the routine can know upper limit.
1928 static noinline_for_stack
1929 void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1930 struct ext4_buddy *e4b)
1932 struct super_block *sb = ac->ac_sb;
1933 void *bitmap = e4b->bd_bitmap;
1934 struct ext4_free_extent ex;
1935 int i;
1936 int free;
1938 free = e4b->bd_info->bb_free;
1939 BUG_ON(free <= 0);
1941 i = e4b->bd_info->bb_first_free;
1943 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
1944 i = mb_find_next_zero_bit(bitmap,
1945 EXT4_CLUSTERS_PER_GROUP(sb), i);
1946 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
1948 * IF we have corrupt bitmap, we won't find any
1949 * free blocks even though group info says we
1950 * we have free blocks
1952 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
1953 "%d free clusters as per "
1954 "group info. But bitmap says 0",
1955 free);
1956 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
1957 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1958 break;
1961 mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex);
1962 BUG_ON(ex.fe_len <= 0);
1963 if (free < ex.fe_len) {
1964 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
1965 "%d free clusters as per "
1966 "group info. But got %d blocks",
1967 free, ex.fe_len);
1968 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
1969 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1971 * The number of free blocks differs. This mostly
1972 * indicate that the bitmap is corrupt. So exit
1973 * without claiming the space.
1975 break;
1977 ex.fe_logical = 0xDEADC0DE; /* debug value */
1978 ext4_mb_measure_extent(ac, &ex, e4b);
1980 i += ex.fe_len;
1981 free -= ex.fe_len;
1984 ext4_mb_check_limits(ac, e4b, 1);
1988 * This is a special case for storages like raid5
1989 * we try to find stripe-aligned chunks for stripe-size-multiple requests
1991 static noinline_for_stack
1992 void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
1993 struct ext4_buddy *e4b)
1995 struct super_block *sb = ac->ac_sb;
1996 struct ext4_sb_info *sbi = EXT4_SB(sb);
1997 void *bitmap = e4b->bd_bitmap;
1998 struct ext4_free_extent ex;
1999 ext4_fsblk_t first_group_block;
2000 ext4_fsblk_t a;
2001 ext4_grpblk_t i;
2002 int max;
2004 BUG_ON(sbi->s_stripe == 0);
2006 /* find first stripe-aligned block in group */
2007 first_group_block = ext4_group_first_block_no(sb, e4b->bd_group);
2009 a = first_group_block + sbi->s_stripe - 1;
2010 do_div(a, sbi->s_stripe);
2011 i = (a * sbi->s_stripe) - first_group_block;
2013 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2014 if (!mb_test_bit(i, bitmap)) {
2015 max = mb_find_extent(e4b, i, sbi->s_stripe, &ex);
2016 if (max >= sbi->s_stripe) {
2017 ac->ac_found++;
2018 ex.fe_logical = 0xDEADF00D; /* debug value */
2019 ac->ac_b_ex = ex;
2020 ext4_mb_use_best_found(ac, e4b);
2021 break;
2024 i += sbi->s_stripe;
2029 * This is now called BEFORE we load the buddy bitmap.
2030 * Returns either 1 or 0 indicating that the group is either suitable
2031 * for the allocation or not. In addition it can also return negative
2032 * error code when something goes wrong.
2034 static int ext4_mb_good_group(struct ext4_allocation_context *ac,
2035 ext4_group_t group, int cr)
2037 unsigned free, fragments;
2038 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb));
2039 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
2041 BUG_ON(cr < 0 || cr >= 4);
2043 free = grp->bb_free;
2044 if (free == 0)
2045 return 0;
2046 if (cr <= 2 && free < ac->ac_g_ex.fe_len)
2047 return 0;
2049 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2050 return 0;
2052 /* We only do this if the grp has never been initialized */
2053 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2054 int ret = ext4_mb_init_group(ac->ac_sb, group, GFP_NOFS);
2055 if (ret)
2056 return ret;
2059 fragments = grp->bb_fragments;
2060 if (fragments == 0)
2061 return 0;
2063 switch (cr) {
2064 case 0:
2065 BUG_ON(ac->ac_2order == 0);
2067 /* Avoid using the first bg of a flexgroup for data files */
2068 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2069 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2070 ((group % flex_size) == 0))
2071 return 0;
2073 if ((ac->ac_2order > ac->ac_sb->s_blocksize_bits+1) ||
2074 (free / fragments) >= ac->ac_g_ex.fe_len)
2075 return 1;
2077 if (grp->bb_largest_free_order < ac->ac_2order)
2078 return 0;
2080 return 1;
2081 case 1:
2082 if ((free / fragments) >= ac->ac_g_ex.fe_len)
2083 return 1;
2084 break;
2085 case 2:
2086 if (free >= ac->ac_g_ex.fe_len)
2087 return 1;
2088 break;
2089 case 3:
2090 return 1;
2091 default:
2092 BUG();
2095 return 0;
2098 static noinline_for_stack int
2099 ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2101 ext4_group_t ngroups, group, i;
2102 int cr;
2103 int err = 0, first_err = 0;
2104 struct ext4_sb_info *sbi;
2105 struct super_block *sb;
2106 struct ext4_buddy e4b;
2108 sb = ac->ac_sb;
2109 sbi = EXT4_SB(sb);
2110 ngroups = ext4_get_groups_count(sb);
2111 /* non-extent files are limited to low blocks/groups */
2112 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)))
2113 ngroups = sbi->s_blockfile_groups;
2115 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2117 /* first, try the goal */
2118 err = ext4_mb_find_by_goal(ac, &e4b);
2119 if (err || ac->ac_status == AC_STATUS_FOUND)
2120 goto out;
2122 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2123 goto out;
2126 * ac->ac2_order is set only if the fe_len is a power of 2
2127 * if ac2_order is set we also set criteria to 0 so that we
2128 * try exact allocation using buddy.
2130 i = fls(ac->ac_g_ex.fe_len);
2131 ac->ac_2order = 0;
2133 * We search using buddy data only if the order of the request
2134 * is greater than equal to the sbi_s_mb_order2_reqs
2135 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2136 * We also support searching for power-of-two requests only for
2137 * requests upto maximum buddy size we have constructed.
2139 if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
2141 * This should tell if fe_len is exactly power of 2
2143 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
2144 ac->ac_2order = array_index_nospec(i - 1,
2145 sb->s_blocksize_bits + 2);
2148 /* if stream allocation is enabled, use global goal */
2149 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2150 /* TBD: may be hot point */
2151 spin_lock(&sbi->s_md_lock);
2152 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2153 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2154 spin_unlock(&sbi->s_md_lock);
2157 /* Let's just scan groups to find more-less suitable blocks */
2158 cr = ac->ac_2order ? 0 : 1;
2160 * cr == 0 try to get exact allocation,
2161 * cr == 3 try to get anything
2163 repeat:
2164 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2165 ac->ac_criteria = cr;
2167 * searching for the right group start
2168 * from the goal value specified
2170 group = ac->ac_g_ex.fe_group;
2172 for (i = 0; i < ngroups; group++, i++) {
2173 int ret = 0;
2174 cond_resched();
2176 * Artificially restricted ngroups for non-extent
2177 * files makes group > ngroups possible on first loop.
2179 if (group >= ngroups)
2180 group = 0;
2182 /* This now checks without needing the buddy page */
2183 ret = ext4_mb_good_group(ac, group, cr);
2184 if (ret <= 0) {
2185 if (!first_err)
2186 first_err = ret;
2187 continue;
2190 err = ext4_mb_load_buddy(sb, group, &e4b);
2191 if (err)
2192 goto out;
2194 ext4_lock_group(sb, group);
2197 * We need to check again after locking the
2198 * block group
2200 ret = ext4_mb_good_group(ac, group, cr);
2201 if (ret <= 0) {
2202 ext4_unlock_group(sb, group);
2203 ext4_mb_unload_buddy(&e4b);
2204 if (!first_err)
2205 first_err = ret;
2206 continue;
2209 ac->ac_groups_scanned++;
2210 if (cr == 0)
2211 ext4_mb_simple_scan_group(ac, &e4b);
2212 else if (cr == 1 && sbi->s_stripe &&
2213 !(ac->ac_g_ex.fe_len % sbi->s_stripe))
2214 ext4_mb_scan_aligned(ac, &e4b);
2215 else
2216 ext4_mb_complex_scan_group(ac, &e4b);
2218 ext4_unlock_group(sb, group);
2219 ext4_mb_unload_buddy(&e4b);
2221 if (ac->ac_status != AC_STATUS_CONTINUE)
2222 break;
2226 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2227 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2229 * We've been searching too long. Let's try to allocate
2230 * the best chunk we've found so far
2233 ext4_mb_try_best_found(ac, &e4b);
2234 if (ac->ac_status != AC_STATUS_FOUND) {
2236 * Someone more lucky has already allocated it.
2237 * The only thing we can do is just take first
2238 * found block(s)
2239 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2241 ac->ac_b_ex.fe_group = 0;
2242 ac->ac_b_ex.fe_start = 0;
2243 ac->ac_b_ex.fe_len = 0;
2244 ac->ac_status = AC_STATUS_CONTINUE;
2245 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2246 cr = 3;
2247 atomic_inc(&sbi->s_mb_lost_chunks);
2248 goto repeat;
2251 out:
2252 if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
2253 err = first_err;
2254 return err;
2257 static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2259 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2260 ext4_group_t group;
2262 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2263 return NULL;
2264 group = *pos + 1;
2265 return (void *) ((unsigned long) group);
2268 static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2270 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2271 ext4_group_t group;
2273 ++*pos;
2274 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
2275 return NULL;
2276 group = *pos + 1;
2277 return (void *) ((unsigned long) group);
2280 static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2282 struct super_block *sb = PDE_DATA(file_inode(seq->file));
2283 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
2284 int i;
2285 int err, buddy_loaded = 0;
2286 struct ext4_buddy e4b;
2287 struct ext4_group_info *grinfo;
2288 unsigned char blocksize_bits = min_t(unsigned char,
2289 sb->s_blocksize_bits,
2290 EXT4_MAX_BLOCK_LOG_SIZE);
2291 struct sg {
2292 struct ext4_group_info info;
2293 ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
2294 } sg;
2296 group--;
2297 if (group == 0)
2298 seq_puts(seq, "#group: free frags first ["
2299 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
2300 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
2302 i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2303 sizeof(struct ext4_group_info);
2305 grinfo = ext4_get_group_info(sb, group);
2306 /* Load the group info in memory only if not already loaded. */
2307 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
2308 err = ext4_mb_load_buddy(sb, group, &e4b);
2309 if (err) {
2310 seq_printf(seq, "#%-5u: I/O error\n", group);
2311 return 0;
2313 buddy_loaded = 1;
2316 memcpy(&sg, ext4_get_group_info(sb, group), i);
2318 if (buddy_loaded)
2319 ext4_mb_unload_buddy(&e4b);
2321 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
2322 sg.info.bb_fragments, sg.info.bb_first_free);
2323 for (i = 0; i <= 13; i++)
2324 seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
2325 sg.info.bb_counters[i] : 0);
2326 seq_printf(seq, " ]\n");
2328 return 0;
2331 static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2335 const struct seq_operations ext4_mb_seq_groups_ops = {
2336 .start = ext4_mb_seq_groups_start,
2337 .next = ext4_mb_seq_groups_next,
2338 .stop = ext4_mb_seq_groups_stop,
2339 .show = ext4_mb_seq_groups_show,
2342 static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
2344 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2345 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
2347 BUG_ON(!cachep);
2348 return cachep;
2352 * Allocate the top-level s_group_info array for the specified number
2353 * of groups
2355 int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
2357 struct ext4_sb_info *sbi = EXT4_SB(sb);
2358 unsigned size;
2359 struct ext4_group_info ***old_groupinfo, ***new_groupinfo;
2361 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
2362 EXT4_DESC_PER_BLOCK_BITS(sb);
2363 if (size <= sbi->s_group_info_size)
2364 return 0;
2366 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
2367 new_groupinfo = kvzalloc(size, GFP_KERNEL);
2368 if (!new_groupinfo) {
2369 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
2370 return -ENOMEM;
2372 rcu_read_lock();
2373 old_groupinfo = rcu_dereference(sbi->s_group_info);
2374 if (old_groupinfo)
2375 memcpy(new_groupinfo, old_groupinfo,
2376 sbi->s_group_info_size * sizeof(*sbi->s_group_info));
2377 rcu_read_unlock();
2378 rcu_assign_pointer(sbi->s_group_info, new_groupinfo);
2379 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
2380 if (old_groupinfo)
2381 ext4_kvfree_array_rcu(old_groupinfo);
2382 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
2383 sbi->s_group_info_size);
2384 return 0;
2387 /* Create and initialize ext4_group_info data for the given group. */
2388 int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
2389 struct ext4_group_desc *desc)
2391 int i;
2392 int metalen = 0;
2393 int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb);
2394 struct ext4_sb_info *sbi = EXT4_SB(sb);
2395 struct ext4_group_info **meta_group_info;
2396 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2399 * First check if this group is the first of a reserved block.
2400 * If it's true, we have to allocate a new table of pointers
2401 * to ext4_group_info structures
2403 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2404 metalen = sizeof(*meta_group_info) <<
2405 EXT4_DESC_PER_BLOCK_BITS(sb);
2406 meta_group_info = kmalloc(metalen, GFP_NOFS);
2407 if (meta_group_info == NULL) {
2408 ext4_msg(sb, KERN_ERR, "can't allocate mem "
2409 "for a buddy group");
2410 goto exit_meta_group_info;
2412 rcu_read_lock();
2413 rcu_dereference(sbi->s_group_info)[idx] = meta_group_info;
2414 rcu_read_unlock();
2417 meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx);
2418 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
2420 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
2421 if (meta_group_info[i] == NULL) {
2422 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
2423 goto exit_group_info;
2425 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2426 &(meta_group_info[i]->bb_state));
2429 * initialize bb_free to be able to skip
2430 * empty groups without initialization
2432 if (ext4_has_group_desc_csum(sb) &&
2433 (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
2434 meta_group_info[i]->bb_free =
2435 ext4_free_clusters_after_init(sb, group, desc);
2436 } else {
2437 meta_group_info[i]->bb_free =
2438 ext4_free_group_clusters(sb, desc);
2441 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
2442 init_rwsem(&meta_group_info[i]->alloc_sem);
2443 meta_group_info[i]->bb_free_root = RB_ROOT;
2444 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
2446 #ifdef DOUBLE_CHECK
2448 struct buffer_head *bh;
2449 meta_group_info[i]->bb_bitmap =
2450 kmalloc(sb->s_blocksize, GFP_NOFS);
2451 BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
2452 bh = ext4_read_block_bitmap(sb, group);
2453 BUG_ON(IS_ERR_OR_NULL(bh));
2454 memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
2455 sb->s_blocksize);
2456 put_bh(bh);
2458 #endif
2460 return 0;
2462 exit_group_info:
2463 /* If a meta_group_info table has been allocated, release it now */
2464 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2465 struct ext4_group_info ***group_info;
2467 rcu_read_lock();
2468 group_info = rcu_dereference(sbi->s_group_info);
2469 kfree(group_info[idx]);
2470 group_info[idx] = NULL;
2471 rcu_read_unlock();
2473 exit_meta_group_info:
2474 return -ENOMEM;
2475 } /* ext4_mb_add_groupinfo */
2477 static int ext4_mb_init_backend(struct super_block *sb)
2479 ext4_group_t ngroups = ext4_get_groups_count(sb);
2480 ext4_group_t i;
2481 struct ext4_sb_info *sbi = EXT4_SB(sb);
2482 int err;
2483 struct ext4_group_desc *desc;
2484 struct ext4_group_info ***group_info;
2485 struct kmem_cache *cachep;
2487 err = ext4_mb_alloc_groupinfo(sb, ngroups);
2488 if (err)
2489 return err;
2491 sbi->s_buddy_cache = new_inode(sb);
2492 if (sbi->s_buddy_cache == NULL) {
2493 ext4_msg(sb, KERN_ERR, "can't get new inode");
2494 goto err_freesgi;
2496 /* To avoid potentially colliding with an valid on-disk inode number,
2497 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
2498 * not in the inode hash, so it should never be found by iget(), but
2499 * this will avoid confusion if it ever shows up during debugging. */
2500 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
2501 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2502 for (i = 0; i < ngroups; i++) {
2503 cond_resched();
2504 desc = ext4_get_group_desc(sb, i, NULL);
2505 if (desc == NULL) {
2506 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
2507 goto err_freebuddy;
2509 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
2510 goto err_freebuddy;
2513 return 0;
2515 err_freebuddy:
2516 cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2517 while (i-- > 0)
2518 kmem_cache_free(cachep, ext4_get_group_info(sb, i));
2519 i = sbi->s_group_info_size;
2520 rcu_read_lock();
2521 group_info = rcu_dereference(sbi->s_group_info);
2522 while (i-- > 0)
2523 kfree(group_info[i]);
2524 rcu_read_unlock();
2525 iput(sbi->s_buddy_cache);
2526 err_freesgi:
2527 rcu_read_lock();
2528 kvfree(rcu_dereference(sbi->s_group_info));
2529 rcu_read_unlock();
2530 return -ENOMEM;
2533 static void ext4_groupinfo_destroy_slabs(void)
2535 int i;
2537 for (i = 0; i < NR_GRPINFO_CACHES; i++) {
2538 kmem_cache_destroy(ext4_groupinfo_caches[i]);
2539 ext4_groupinfo_caches[i] = NULL;
2543 static int ext4_groupinfo_create_slab(size_t size)
2545 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
2546 int slab_size;
2547 int blocksize_bits = order_base_2(size);
2548 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
2549 struct kmem_cache *cachep;
2551 if (cache_index >= NR_GRPINFO_CACHES)
2552 return -EINVAL;
2554 if (unlikely(cache_index < 0))
2555 cache_index = 0;
2557 mutex_lock(&ext4_grpinfo_slab_create_mutex);
2558 if (ext4_groupinfo_caches[cache_index]) {
2559 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2560 return 0; /* Already created */
2563 slab_size = offsetof(struct ext4_group_info,
2564 bb_counters[blocksize_bits + 2]);
2566 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
2567 slab_size, 0, SLAB_RECLAIM_ACCOUNT,
2568 NULL);
2570 ext4_groupinfo_caches[cache_index] = cachep;
2572 mutex_unlock(&ext4_grpinfo_slab_create_mutex);
2573 if (!cachep) {
2574 printk(KERN_EMERG
2575 "EXT4-fs: no memory for groupinfo slab cache\n");
2576 return -ENOMEM;
2579 return 0;
2582 int ext4_mb_init(struct super_block *sb)
2584 struct ext4_sb_info *sbi = EXT4_SB(sb);
2585 unsigned i, j;
2586 unsigned offset, offset_incr;
2587 unsigned max;
2588 int ret;
2590 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
2592 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2593 if (sbi->s_mb_offsets == NULL) {
2594 ret = -ENOMEM;
2595 goto out;
2598 i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
2599 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2600 if (sbi->s_mb_maxs == NULL) {
2601 ret = -ENOMEM;
2602 goto out;
2605 ret = ext4_groupinfo_create_slab(sb->s_blocksize);
2606 if (ret < 0)
2607 goto out;
2609 /* order 0 is regular bitmap */
2610 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2611 sbi->s_mb_offsets[0] = 0;
2613 i = 1;
2614 offset = 0;
2615 offset_incr = 1 << (sb->s_blocksize_bits - 1);
2616 max = sb->s_blocksize << 2;
2617 do {
2618 sbi->s_mb_offsets[i] = offset;
2619 sbi->s_mb_maxs[i] = max;
2620 offset += offset_incr;
2621 offset_incr = offset_incr >> 1;
2622 max = max >> 1;
2623 i++;
2624 } while (i <= sb->s_blocksize_bits + 1);
2626 spin_lock_init(&sbi->s_md_lock);
2627 spin_lock_init(&sbi->s_bal_lock);
2628 sbi->s_mb_free_pending = 0;
2629 INIT_LIST_HEAD(&sbi->s_freed_data_list);
2631 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2632 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2633 sbi->s_mb_stats = MB_DEFAULT_STATS;
2634 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2635 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2637 * The default group preallocation is 512, which for 4k block
2638 * sizes translates to 2 megabytes. However for bigalloc file
2639 * systems, this is probably too big (i.e, if the cluster size
2640 * is 1 megabyte, then group preallocation size becomes half a
2641 * gigabyte!). As a default, we will keep a two megabyte
2642 * group pralloc size for cluster sizes up to 64k, and after
2643 * that, we will force a minimum group preallocation size of
2644 * 32 clusters. This translates to 8 megs when the cluster
2645 * size is 256k, and 32 megs when the cluster size is 1 meg,
2646 * which seems reasonable as a default.
2648 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
2649 sbi->s_cluster_bits, 32);
2651 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
2652 * to the lowest multiple of s_stripe which is bigger than
2653 * the s_mb_group_prealloc as determined above. We want
2654 * the preallocation size to be an exact multiple of the
2655 * RAID stripe size so that preallocations don't fragment
2656 * the stripes.
2658 if (sbi->s_stripe > 1) {
2659 sbi->s_mb_group_prealloc = roundup(
2660 sbi->s_mb_group_prealloc, sbi->s_stripe);
2663 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
2664 if (sbi->s_locality_groups == NULL) {
2665 ret = -ENOMEM;
2666 goto out;
2668 for_each_possible_cpu(i) {
2669 struct ext4_locality_group *lg;
2670 lg = per_cpu_ptr(sbi->s_locality_groups, i);
2671 mutex_init(&lg->lg_mutex);
2672 for (j = 0; j < PREALLOC_TB_SIZE; j++)
2673 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
2674 spin_lock_init(&lg->lg_prealloc_lock);
2677 /* init file for buddy data */
2678 ret = ext4_mb_init_backend(sb);
2679 if (ret != 0)
2680 goto out_free_locality_groups;
2682 return 0;
2684 out_free_locality_groups:
2685 free_percpu(sbi->s_locality_groups);
2686 sbi->s_locality_groups = NULL;
2687 out:
2688 kfree(sbi->s_mb_offsets);
2689 sbi->s_mb_offsets = NULL;
2690 kfree(sbi->s_mb_maxs);
2691 sbi->s_mb_maxs = NULL;
2692 return ret;
2695 /* need to called with the ext4 group lock held */
2696 static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2698 struct ext4_prealloc_space *pa;
2699 struct list_head *cur, *tmp;
2700 int count = 0;
2702 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2703 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2704 list_del(&pa->pa_group_list);
2705 count++;
2706 kmem_cache_free(ext4_pspace_cachep, pa);
2708 if (count)
2709 mb_debug(1, "mballoc: %u PAs left\n", count);
2713 int ext4_mb_release(struct super_block *sb)
2715 ext4_group_t ngroups = ext4_get_groups_count(sb);
2716 ext4_group_t i;
2717 int num_meta_group_infos;
2718 struct ext4_group_info *grinfo, ***group_info;
2719 struct ext4_sb_info *sbi = EXT4_SB(sb);
2720 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
2722 if (sbi->s_group_info) {
2723 for (i = 0; i < ngroups; i++) {
2724 cond_resched();
2725 grinfo = ext4_get_group_info(sb, i);
2726 #ifdef DOUBLE_CHECK
2727 kfree(grinfo->bb_bitmap);
2728 #endif
2729 ext4_lock_group(sb, i);
2730 ext4_mb_cleanup_pa(grinfo);
2731 ext4_unlock_group(sb, i);
2732 kmem_cache_free(cachep, grinfo);
2734 num_meta_group_infos = (ngroups +
2735 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2736 EXT4_DESC_PER_BLOCK_BITS(sb);
2737 rcu_read_lock();
2738 group_info = rcu_dereference(sbi->s_group_info);
2739 for (i = 0; i < num_meta_group_infos; i++)
2740 kfree(group_info[i]);
2741 kvfree(group_info);
2742 rcu_read_unlock();
2744 kfree(sbi->s_mb_offsets);
2745 kfree(sbi->s_mb_maxs);
2746 iput(sbi->s_buddy_cache);
2747 if (sbi->s_mb_stats) {
2748 ext4_msg(sb, KERN_INFO,
2749 "mballoc: %u blocks %u reqs (%u success)",
2750 atomic_read(&sbi->s_bal_allocated),
2751 atomic_read(&sbi->s_bal_reqs),
2752 atomic_read(&sbi->s_bal_success));
2753 ext4_msg(sb, KERN_INFO,
2754 "mballoc: %u extents scanned, %u goal hits, "
2755 "%u 2^N hits, %u breaks, %u lost",
2756 atomic_read(&sbi->s_bal_ex_scanned),
2757 atomic_read(&sbi->s_bal_goals),
2758 atomic_read(&sbi->s_bal_2orders),
2759 atomic_read(&sbi->s_bal_breaks),
2760 atomic_read(&sbi->s_mb_lost_chunks));
2761 ext4_msg(sb, KERN_INFO,
2762 "mballoc: %lu generated and it took %Lu",
2763 sbi->s_mb_buddies_generated,
2764 sbi->s_mb_generation_time);
2765 ext4_msg(sb, KERN_INFO,
2766 "mballoc: %u preallocated, %u discarded",
2767 atomic_read(&sbi->s_mb_preallocated),
2768 atomic_read(&sbi->s_mb_discarded));
2771 free_percpu(sbi->s_locality_groups);
2773 return 0;
2776 static inline int ext4_issue_discard(struct super_block *sb,
2777 ext4_group_t block_group, ext4_grpblk_t cluster, int count,
2778 struct bio **biop)
2780 ext4_fsblk_t discard_block;
2782 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
2783 ext4_group_first_block_no(sb, block_group));
2784 count = EXT4_C2B(EXT4_SB(sb), count);
2785 trace_ext4_discard_blocks(sb,
2786 (unsigned long long) discard_block, count);
2787 if (biop) {
2788 return __blkdev_issue_discard(sb->s_bdev,
2789 (sector_t)discard_block << (sb->s_blocksize_bits - 9),
2790 (sector_t)count << (sb->s_blocksize_bits - 9),
2791 GFP_NOFS, 0, biop);
2792 } else
2793 return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
2796 static void ext4_free_data_in_buddy(struct super_block *sb,
2797 struct ext4_free_data *entry)
2799 struct ext4_buddy e4b;
2800 struct ext4_group_info *db;
2801 int err, count = 0, count2 = 0;
2803 mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
2804 entry->efd_count, entry->efd_group, entry);
2806 err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
2807 /* we expect to find existing buddy because it's pinned */
2808 BUG_ON(err != 0);
2810 spin_lock(&EXT4_SB(sb)->s_md_lock);
2811 EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
2812 spin_unlock(&EXT4_SB(sb)->s_md_lock);
2814 db = e4b.bd_info;
2815 /* there are blocks to put in buddy to make them really free */
2816 count += entry->efd_count;
2817 count2++;
2818 ext4_lock_group(sb, entry->efd_group);
2819 /* Take it out of per group rb tree */
2820 rb_erase(&entry->efd_node, &(db->bb_free_root));
2821 mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count);
2824 * Clear the trimmed flag for the group so that the next
2825 * ext4_trim_fs can trim it.
2826 * If the volume is mounted with -o discard, online discard
2827 * is supported and the free blocks will be trimmed online.
2829 if (!test_opt(sb, DISCARD))
2830 EXT4_MB_GRP_CLEAR_TRIMMED(db);
2832 if (!db->bb_free_root.rb_node) {
2833 /* No more items in the per group rb tree
2834 * balance refcounts from ext4_mb_free_metadata()
2836 put_page(e4b.bd_buddy_page);
2837 put_page(e4b.bd_bitmap_page);
2839 ext4_unlock_group(sb, entry->efd_group);
2840 kmem_cache_free(ext4_free_data_cachep, entry);
2841 ext4_mb_unload_buddy(&e4b);
2843 mb_debug(1, "freed %u blocks in %u structures\n", count, count2);
2847 * This function is called by the jbd2 layer once the commit has finished,
2848 * so we know we can free the blocks that were released with that commit.
2850 void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
2852 struct ext4_sb_info *sbi = EXT4_SB(sb);
2853 struct ext4_free_data *entry, *tmp;
2854 struct bio *discard_bio = NULL;
2855 struct list_head freed_data_list;
2856 struct list_head *cut_pos = NULL;
2857 int err;
2859 INIT_LIST_HEAD(&freed_data_list);
2861 spin_lock(&sbi->s_md_lock);
2862 list_for_each_entry(entry, &sbi->s_freed_data_list, efd_list) {
2863 if (entry->efd_tid != commit_tid)
2864 break;
2865 cut_pos = &entry->efd_list;
2867 if (cut_pos)
2868 list_cut_position(&freed_data_list, &sbi->s_freed_data_list,
2869 cut_pos);
2870 spin_unlock(&sbi->s_md_lock);
2872 if (test_opt(sb, DISCARD)) {
2873 list_for_each_entry(entry, &freed_data_list, efd_list) {
2874 err = ext4_issue_discard(sb, entry->efd_group,
2875 entry->efd_start_cluster,
2876 entry->efd_count,
2877 &discard_bio);
2878 if (err && err != -EOPNOTSUPP) {
2879 ext4_msg(sb, KERN_WARNING, "discard request in"
2880 " group:%d block:%d count:%d failed"
2881 " with %d", entry->efd_group,
2882 entry->efd_start_cluster,
2883 entry->efd_count, err);
2884 } else if (err == -EOPNOTSUPP)
2885 break;
2888 if (discard_bio) {
2889 submit_bio_wait(discard_bio);
2890 bio_put(discard_bio);
2894 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
2895 ext4_free_data_in_buddy(sb, entry);
2898 int __init ext4_init_mballoc(void)
2900 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
2901 SLAB_RECLAIM_ACCOUNT);
2902 if (ext4_pspace_cachep == NULL)
2903 return -ENOMEM;
2905 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
2906 SLAB_RECLAIM_ACCOUNT);
2907 if (ext4_ac_cachep == NULL) {
2908 kmem_cache_destroy(ext4_pspace_cachep);
2909 return -ENOMEM;
2912 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
2913 SLAB_RECLAIM_ACCOUNT);
2914 if (ext4_free_data_cachep == NULL) {
2915 kmem_cache_destroy(ext4_pspace_cachep);
2916 kmem_cache_destroy(ext4_ac_cachep);
2917 return -ENOMEM;
2919 return 0;
2922 void ext4_exit_mballoc(void)
2925 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
2926 * before destroying the slab cache.
2928 rcu_barrier();
2929 kmem_cache_destroy(ext4_pspace_cachep);
2930 kmem_cache_destroy(ext4_ac_cachep);
2931 kmem_cache_destroy(ext4_free_data_cachep);
2932 ext4_groupinfo_destroy_slabs();
2937 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
2938 * Returns 0 if success or error code
2940 static noinline_for_stack int
2941 ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
2942 handle_t *handle, unsigned int reserv_clstrs)
2944 struct buffer_head *bitmap_bh = NULL;
2945 struct ext4_group_desc *gdp;
2946 struct buffer_head *gdp_bh;
2947 struct ext4_sb_info *sbi;
2948 struct super_block *sb;
2949 ext4_fsblk_t block;
2950 int err, len;
2952 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
2953 BUG_ON(ac->ac_b_ex.fe_len <= 0);
2955 sb = ac->ac_sb;
2956 sbi = EXT4_SB(sb);
2958 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
2959 if (IS_ERR(bitmap_bh)) {
2960 err = PTR_ERR(bitmap_bh);
2961 bitmap_bh = NULL;
2962 goto out_err;
2965 BUFFER_TRACE(bitmap_bh, "getting write access");
2966 err = ext4_journal_get_write_access(handle, bitmap_bh);
2967 if (err)
2968 goto out_err;
2970 err = -EIO;
2971 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
2972 if (!gdp)
2973 goto out_err;
2975 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
2976 ext4_free_group_clusters(sb, gdp));
2978 BUFFER_TRACE(gdp_bh, "get_write_access");
2979 err = ext4_journal_get_write_access(handle, gdp_bh);
2980 if (err)
2981 goto out_err;
2983 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
2985 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
2986 if (!ext4_data_block_valid(sbi, block, len)) {
2987 ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
2988 "fs metadata", block, block+len);
2989 /* File system mounted not to panic on error
2990 * Fix the bitmap and return EFSCORRUPTED
2991 * We leak some of the blocks here.
2993 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
2994 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
2995 ac->ac_b_ex.fe_len);
2996 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
2997 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
2998 if (!err)
2999 err = -EFSCORRUPTED;
3000 goto out_err;
3003 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3004 #ifdef AGGRESSIVE_CHECK
3006 int i;
3007 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3008 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3009 bitmap_bh->b_data));
3012 #endif
3013 ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,
3014 ac->ac_b_ex.fe_len);
3015 if (ext4_has_group_desc_csum(sb) &&
3016 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3017 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3018 ext4_free_group_clusters_set(sb, gdp,
3019 ext4_free_clusters_after_init(sb,
3020 ac->ac_b_ex.fe_group, gdp));
3022 len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
3023 ext4_free_group_clusters_set(sb, gdp, len);
3024 ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
3025 ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);
3027 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3028 percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len);
3030 * Now reduce the dirty block count also. Should not go negative
3032 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
3033 /* release all the reserved blocks if non delalloc */
3034 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
3035 reserv_clstrs);
3037 if (sbi->s_log_groups_per_flex) {
3038 ext4_group_t flex_group = ext4_flex_group(sbi,
3039 ac->ac_b_ex.fe_group);
3040 atomic64_sub(ac->ac_b_ex.fe_len,
3041 &sbi_array_rcu_deref(sbi, s_flex_groups,
3042 flex_group)->free_clusters);
3045 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
3046 if (err)
3047 goto out_err;
3048 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
3050 out_err:
3051 brelse(bitmap_bh);
3052 return err;
3056 * here we normalize request for locality group
3057 * Group request are normalized to s_mb_group_prealloc, which goes to
3058 * s_strip if we set the same via mount option.
3059 * s_mb_group_prealloc can be configured via
3060 * /sys/fs/ext4/<partition>/mb_group_prealloc
3062 * XXX: should we try to preallocate more than the group has now?
3064 static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3066 struct super_block *sb = ac->ac_sb;
3067 struct ext4_locality_group *lg = ac->ac_lg;
3069 BUG_ON(lg == NULL);
3070 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3071 mb_debug(1, "#%u: goal %u blocks for locality group\n",
3072 current->pid, ac->ac_g_ex.fe_len);
3076 * Normalization means making request better in terms of
3077 * size and alignment
3079 static noinline_for_stack void
3080 ext4_mb_normalize_request(struct ext4_allocation_context *ac,
3081 struct ext4_allocation_request *ar)
3083 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3084 int bsbits, max;
3085 ext4_lblk_t end;
3086 loff_t size, start_off;
3087 loff_t orig_size __maybe_unused;
3088 ext4_lblk_t start;
3089 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3090 struct ext4_prealloc_space *pa;
3092 /* do normalize only data requests, metadata requests
3093 do not need preallocation */
3094 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3095 return;
3097 /* sometime caller may want exact blocks */
3098 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3099 return;
3101 /* caller may indicate that preallocation isn't
3102 * required (it's a tail, for example) */
3103 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3104 return;
3106 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3107 ext4_mb_normalize_group_request(ac);
3108 return ;
3111 bsbits = ac->ac_sb->s_blocksize_bits;
3113 /* first, let's learn actual file size
3114 * given current request is allocated */
3115 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
3116 size = size << bsbits;
3117 if (size < i_size_read(ac->ac_inode))
3118 size = i_size_read(ac->ac_inode);
3119 orig_size = size;
3121 /* max size of free chunks */
3122 max = 2 << bsbits;
3124 #define NRL_CHECK_SIZE(req, size, max, chunk_size) \
3125 (req <= (size) || max <= (chunk_size))
3127 /* first, try to predict filesize */
3128 /* XXX: should this table be tunable? */
3129 start_off = 0;
3130 if (size <= 16 * 1024) {
3131 size = 16 * 1024;
3132 } else if (size <= 32 * 1024) {
3133 size = 32 * 1024;
3134 } else if (size <= 64 * 1024) {
3135 size = 64 * 1024;
3136 } else if (size <= 128 * 1024) {
3137 size = 128 * 1024;
3138 } else if (size <= 256 * 1024) {
3139 size = 256 * 1024;
3140 } else if (size <= 512 * 1024) {
3141 size = 512 * 1024;
3142 } else if (size <= 1024 * 1024) {
3143 size = 1024 * 1024;
3144 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
3145 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3146 (21 - bsbits)) << 21;
3147 size = 2 * 1024 * 1024;
3148 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
3149 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3150 (22 - bsbits)) << 22;
3151 size = 4 * 1024 * 1024;
3152 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3153 (8<<20)>>bsbits, max, 8 * 1024)) {
3154 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3155 (23 - bsbits)) << 23;
3156 size = 8 * 1024 * 1024;
3157 } else {
3158 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
3159 size = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
3160 ac->ac_o_ex.fe_len) << bsbits;
3162 size = size >> bsbits;
3163 start = start_off >> bsbits;
3165 /* don't cover already allocated blocks in selected range */
3166 if (ar->pleft && start <= ar->lleft) {
3167 size -= ar->lleft + 1 - start;
3168 start = ar->lleft + 1;
3170 if (ar->pright && start + size - 1 >= ar->lright)
3171 size -= start + size - ar->lright;
3174 * Trim allocation request for filesystems with artificially small
3175 * groups.
3177 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
3178 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
3180 end = start + size;
3182 /* check we don't cross already preallocated blocks */
3183 rcu_read_lock();
3184 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3185 ext4_lblk_t pa_end;
3187 if (pa->pa_deleted)
3188 continue;
3189 spin_lock(&pa->pa_lock);
3190 if (pa->pa_deleted) {
3191 spin_unlock(&pa->pa_lock);
3192 continue;
3195 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3196 pa->pa_len);
3198 /* PA must not overlap original request */
3199 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3200 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3202 /* skip PAs this normalized request doesn't overlap with */
3203 if (pa->pa_lstart >= end || pa_end <= start) {
3204 spin_unlock(&pa->pa_lock);
3205 continue;
3207 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3209 /* adjust start or end to be adjacent to this pa */
3210 if (pa_end <= ac->ac_o_ex.fe_logical) {
3211 BUG_ON(pa_end < start);
3212 start = pa_end;
3213 } else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3214 BUG_ON(pa->pa_lstart > end);
3215 end = pa->pa_lstart;
3217 spin_unlock(&pa->pa_lock);
3219 rcu_read_unlock();
3220 size = end - start;
3222 /* XXX: extra loop to check we really don't overlap preallocations */
3223 rcu_read_lock();
3224 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3225 ext4_lblk_t pa_end;
3227 spin_lock(&pa->pa_lock);
3228 if (pa->pa_deleted == 0) {
3229 pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
3230 pa->pa_len);
3231 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3233 spin_unlock(&pa->pa_lock);
3235 rcu_read_unlock();
3237 if (start + size <= ac->ac_o_ex.fe_logical &&
3238 start > ac->ac_o_ex.fe_logical) {
3239 ext4_msg(ac->ac_sb, KERN_ERR,
3240 "start %lu, size %lu, fe_logical %lu",
3241 (unsigned long) start, (unsigned long) size,
3242 (unsigned long) ac->ac_o_ex.fe_logical);
3243 BUG();
3245 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3247 /* now prepare goal request */
3249 /* XXX: is it better to align blocks WRT to logical
3250 * placement or satisfy big request as is */
3251 ac->ac_g_ex.fe_logical = start;
3252 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
3254 /* define goal start in order to merge */
3255 if (ar->pright && (ar->lright == (start + size))) {
3256 /* merge to the right */
3257 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3258 &ac->ac_f_ex.fe_group,
3259 &ac->ac_f_ex.fe_start);
3260 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3262 if (ar->pleft && (ar->lleft + 1 == start)) {
3263 /* merge to the left */
3264 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3265 &ac->ac_f_ex.fe_group,
3266 &ac->ac_f_ex.fe_start);
3267 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3270 mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size,
3271 (unsigned) orig_size, (unsigned) start);
3274 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3276 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3278 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3279 atomic_inc(&sbi->s_bal_reqs);
3280 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3281 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
3282 atomic_inc(&sbi->s_bal_success);
3283 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3284 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3285 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3286 atomic_inc(&sbi->s_bal_goals);
3287 if (ac->ac_found > sbi->s_mb_max_to_scan)
3288 atomic_inc(&sbi->s_bal_breaks);
3291 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
3292 trace_ext4_mballoc_alloc(ac);
3293 else
3294 trace_ext4_mballoc_prealloc(ac);
3298 * Called on failure; free up any blocks from the inode PA for this
3299 * context. We don't need this for MB_GROUP_PA because we only change
3300 * pa_free in ext4_mb_release_context(), but on failure, we've already
3301 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
3303 static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
3305 struct ext4_prealloc_space *pa = ac->ac_pa;
3306 struct ext4_buddy e4b;
3307 int err;
3309 if (pa == NULL) {
3310 if (ac->ac_f_ex.fe_len == 0)
3311 return;
3312 err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b);
3313 if (err) {
3315 * This should never happen since we pin the
3316 * pages in the ext4_allocation_context so
3317 * ext4_mb_load_buddy() should never fail.
3319 WARN(1, "mb_load_buddy failed (%d)", err);
3320 return;
3322 ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3323 mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start,
3324 ac->ac_f_ex.fe_len);
3325 ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group);
3326 ext4_mb_unload_buddy(&e4b);
3327 return;
3329 if (pa->pa_type == MB_INODE_PA)
3330 pa->pa_free += ac->ac_b_ex.fe_len;
3334 * use blocks preallocated to inode
3336 static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3337 struct ext4_prealloc_space *pa)
3339 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3340 ext4_fsblk_t start;
3341 ext4_fsblk_t end;
3342 int len;
3344 /* found preallocated blocks, use them */
3345 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3346 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
3347 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
3348 len = EXT4_NUM_B2C(sbi, end - start);
3349 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3350 &ac->ac_b_ex.fe_start);
3351 ac->ac_b_ex.fe_len = len;
3352 ac->ac_status = AC_STATUS_FOUND;
3353 ac->ac_pa = pa;
3355 BUG_ON(start < pa->pa_pstart);
3356 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
3357 BUG_ON(pa->pa_free < len);
3358 pa->pa_free -= len;
3360 mb_debug(1, "use %llu/%u from inode pa %p\n", start, len, pa);
3364 * use blocks preallocated to locality group
3366 static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3367 struct ext4_prealloc_space *pa)
3369 unsigned int len = ac->ac_o_ex.fe_len;
3371 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3372 &ac->ac_b_ex.fe_group,
3373 &ac->ac_b_ex.fe_start);
3374 ac->ac_b_ex.fe_len = len;
3375 ac->ac_status = AC_STATUS_FOUND;
3376 ac->ac_pa = pa;
3378 /* we don't correct pa_pstart or pa_plen here to avoid
3379 * possible race when the group is being loaded concurrently
3380 * instead we correct pa later, after blocks are marked
3381 * in on-disk bitmap -- see ext4_mb_release_context()
3382 * Other CPUs are prevented from allocating from this pa by lg_mutex
3384 mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3388 * Return the prealloc space that have minimal distance
3389 * from the goal block. @cpa is the prealloc
3390 * space that is having currently known minimal distance
3391 * from the goal block.
3393 static struct ext4_prealloc_space *
3394 ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
3395 struct ext4_prealloc_space *pa,
3396 struct ext4_prealloc_space *cpa)
3398 ext4_fsblk_t cur_distance, new_distance;
3400 if (cpa == NULL) {
3401 atomic_inc(&pa->pa_count);
3402 return pa;
3404 cur_distance = abs(goal_block - cpa->pa_pstart);
3405 new_distance = abs(goal_block - pa->pa_pstart);
3407 if (cur_distance <= new_distance)
3408 return cpa;
3410 /* drop the previous reference */
3411 atomic_dec(&cpa->pa_count);
3412 atomic_inc(&pa->pa_count);
3413 return pa;
3417 * search goal blocks in preallocated space
3419 static noinline_for_stack int
3420 ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
3422 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3423 int order, i;
3424 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3425 struct ext4_locality_group *lg;
3426 struct ext4_prealloc_space *pa, *cpa = NULL;
3427 ext4_fsblk_t goal_block;
3429 /* only data can be preallocated */
3430 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3431 return 0;
3433 /* first, try per-file preallocation */
3434 rcu_read_lock();
3435 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
3437 /* all fields in this condition don't change,
3438 * so we can skip locking for them */
3439 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3440 ac->ac_o_ex.fe_logical >= (pa->pa_lstart +
3441 EXT4_C2B(sbi, pa->pa_len)))
3442 continue;
3444 /* non-extent files can't have physical blocks past 2^32 */
3445 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) &&
3446 (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) >
3447 EXT4_MAX_BLOCK_FILE_PHYS))
3448 continue;
3450 /* found preallocated blocks, use them */
3451 spin_lock(&pa->pa_lock);
3452 if (pa->pa_deleted == 0 && pa->pa_free) {
3453 atomic_inc(&pa->pa_count);
3454 ext4_mb_use_inode_pa(ac, pa);
3455 spin_unlock(&pa->pa_lock);
3456 ac->ac_criteria = 10;
3457 rcu_read_unlock();
3458 return 1;
3460 spin_unlock(&pa->pa_lock);
3462 rcu_read_unlock();
3464 /* can we use group allocation? */
3465 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3466 return 0;
3468 /* inode may have no locality group for some reason */
3469 lg = ac->ac_lg;
3470 if (lg == NULL)
3471 return 0;
3472 order = fls(ac->ac_o_ex.fe_len) - 1;
3473 if (order > PREALLOC_TB_SIZE - 1)
3474 /* The max size of hash table is PREALLOC_TB_SIZE */
3475 order = PREALLOC_TB_SIZE - 1;
3477 goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex);
3479 * search for the prealloc space that is having
3480 * minimal distance from the goal block.
3482 for (i = order; i < PREALLOC_TB_SIZE; i++) {
3483 rcu_read_lock();
3484 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
3485 pa_inode_list) {
3486 spin_lock(&pa->pa_lock);
3487 if (pa->pa_deleted == 0 &&
3488 pa->pa_free >= ac->ac_o_ex.fe_len) {
3490 cpa = ext4_mb_check_group_pa(goal_block,
3491 pa, cpa);
3493 spin_unlock(&pa->pa_lock);
3495 rcu_read_unlock();
3497 if (cpa) {
3498 ext4_mb_use_group_pa(ac, cpa);
3499 ac->ac_criteria = 20;
3500 return 1;
3502 return 0;
3506 * the function goes through all block freed in the group
3507 * but not yet committed and marks them used in in-core bitmap.
3508 * buddy must be generated from this bitmap
3509 * Need to be called with the ext4 group lock held
3511 static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
3512 ext4_group_t group)
3514 struct rb_node *n;
3515 struct ext4_group_info *grp;
3516 struct ext4_free_data *entry;
3518 grp = ext4_get_group_info(sb, group);
3519 n = rb_first(&(grp->bb_free_root));
3521 while (n) {
3522 entry = rb_entry(n, struct ext4_free_data, efd_node);
3523 ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count);
3524 n = rb_next(n);
3526 return;
3530 * the function goes through all preallocation in this group and marks them
3531 * used in in-core bitmap. buddy must be generated from this bitmap
3532 * Need to be called with ext4 group lock held
3534 static noinline_for_stack
3535 void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3536 ext4_group_t group)
3538 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3539 struct ext4_prealloc_space *pa;
3540 struct list_head *cur;
3541 ext4_group_t groupnr;
3542 ext4_grpblk_t start;
3543 int preallocated = 0;
3544 int len;
3546 /* all form of preallocation discards first load group,
3547 * so the only competing code is preallocation use.
3548 * we don't need any locking here
3549 * notice we do NOT ignore preallocations with pa_deleted
3550 * otherwise we could leave used blocks available for
3551 * allocation in buddy when concurrent ext4_mb_put_pa()
3552 * is dropping preallocation
3554 list_for_each(cur, &grp->bb_prealloc_list) {
3555 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3556 spin_lock(&pa->pa_lock);
3557 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3558 &groupnr, &start);
3559 len = pa->pa_len;
3560 spin_unlock(&pa->pa_lock);
3561 if (unlikely(len == 0))
3562 continue;
3563 BUG_ON(groupnr != group);
3564 ext4_set_bits(bitmap, start, len);
3565 preallocated += len;
3567 mb_debug(1, "preallocated %u for group %u\n", preallocated, group);
3570 static void ext4_mb_pa_callback(struct rcu_head *head)
3572 struct ext4_prealloc_space *pa;
3573 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3575 BUG_ON(atomic_read(&pa->pa_count));
3576 BUG_ON(pa->pa_deleted == 0);
3577 kmem_cache_free(ext4_pspace_cachep, pa);
3581 * drops a reference to preallocated space descriptor
3582 * if this was the last reference and the space is consumed
3584 static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3585 struct super_block *sb, struct ext4_prealloc_space *pa)
3587 ext4_group_t grp;
3588 ext4_fsblk_t grp_blk;
3590 /* in this short window concurrent discard can set pa_deleted */
3591 spin_lock(&pa->pa_lock);
3592 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {
3593 spin_unlock(&pa->pa_lock);
3594 return;
3597 if (pa->pa_deleted == 1) {
3598 spin_unlock(&pa->pa_lock);
3599 return;
3602 pa->pa_deleted = 1;
3603 spin_unlock(&pa->pa_lock);
3605 grp_blk = pa->pa_pstart;
3607 * If doing group-based preallocation, pa_pstart may be in the
3608 * next group when pa is used up
3610 if (pa->pa_type == MB_GROUP_PA)
3611 grp_blk--;
3613 grp = ext4_get_group_number(sb, grp_blk);
3616 * possible race:
3618 * P1 (buddy init) P2 (regular allocation)
3619 * find block B in PA
3620 * copy on-disk bitmap to buddy
3621 * mark B in on-disk bitmap
3622 * drop PA from group
3623 * mark all PAs in buddy
3625 * thus, P1 initializes buddy with B available. to prevent this
3626 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3627 * against that pair
3629 ext4_lock_group(sb, grp);
3630 list_del(&pa->pa_group_list);
3631 ext4_unlock_group(sb, grp);
3633 spin_lock(pa->pa_obj_lock);
3634 list_del_rcu(&pa->pa_inode_list);
3635 spin_unlock(pa->pa_obj_lock);
3637 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3641 * creates new preallocated space for given inode
3643 static noinline_for_stack int
3644 ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
3646 struct super_block *sb = ac->ac_sb;
3647 struct ext4_sb_info *sbi = EXT4_SB(sb);
3648 struct ext4_prealloc_space *pa;
3649 struct ext4_group_info *grp;
3650 struct ext4_inode_info *ei;
3652 /* preallocate only when found space is larger then requested */
3653 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3654 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3655 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3657 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3658 if (pa == NULL)
3659 return -ENOMEM;
3661 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3662 int winl;
3663 int wins;
3664 int win;
3665 int offs;
3667 /* we can't allocate as much as normalizer wants.
3668 * so, found space must get proper lstart
3669 * to cover original request */
3670 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3671 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3673 /* we're limited by original request in that
3674 * logical block must be covered any way
3675 * winl is window we can move our chunk within */
3676 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
3678 /* also, we should cover whole original request */
3679 wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len);
3681 /* the smallest one defines real window */
3682 win = min(winl, wins);
3684 offs = ac->ac_o_ex.fe_logical %
3685 EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
3686 if (offs && offs < win)
3687 win = offs;
3689 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical -
3690 EXT4_NUM_B2C(sbi, win);
3691 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3692 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3695 /* preallocation can change ac_b_ex, thus we store actually
3696 * allocated blocks for history */
3697 ac->ac_f_ex = ac->ac_b_ex;
3699 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3700 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3701 pa->pa_len = ac->ac_b_ex.fe_len;
3702 pa->pa_free = pa->pa_len;
3703 atomic_set(&pa->pa_count, 1);
3704 spin_lock_init(&pa->pa_lock);
3705 INIT_LIST_HEAD(&pa->pa_inode_list);
3706 INIT_LIST_HEAD(&pa->pa_group_list);
3707 pa->pa_deleted = 0;
3708 pa->pa_type = MB_INODE_PA;
3710 mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa,
3711 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3712 trace_ext4_mb_new_inode_pa(ac, pa);
3714 ext4_mb_use_inode_pa(ac, pa);
3715 atomic_add(pa->pa_free, &sbi->s_mb_preallocated);
3717 ei = EXT4_I(ac->ac_inode);
3718 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3720 pa->pa_obj_lock = &ei->i_prealloc_lock;
3721 pa->pa_inode = ac->ac_inode;
3723 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3724 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3725 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3727 spin_lock(pa->pa_obj_lock);
3728 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3729 spin_unlock(pa->pa_obj_lock);
3731 return 0;
3735 * creates new preallocated space for locality group inodes belongs to
3737 static noinline_for_stack int
3738 ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
3740 struct super_block *sb = ac->ac_sb;
3741 struct ext4_locality_group *lg;
3742 struct ext4_prealloc_space *pa;
3743 struct ext4_group_info *grp;
3745 /* preallocate only when found space is larger then requested */
3746 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3747 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3748 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3750 BUG_ON(ext4_pspace_cachep == NULL);
3751 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3752 if (pa == NULL)
3753 return -ENOMEM;
3755 /* preallocation can change ac_b_ex, thus we store actually
3756 * allocated blocks for history */
3757 ac->ac_f_ex = ac->ac_b_ex;
3759 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3760 pa->pa_lstart = pa->pa_pstart;
3761 pa->pa_len = ac->ac_b_ex.fe_len;
3762 pa->pa_free = pa->pa_len;
3763 atomic_set(&pa->pa_count, 1);
3764 spin_lock_init(&pa->pa_lock);
3765 INIT_LIST_HEAD(&pa->pa_inode_list);
3766 INIT_LIST_HEAD(&pa->pa_group_list);
3767 pa->pa_deleted = 0;
3768 pa->pa_type = MB_GROUP_PA;
3770 mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa,
3771 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3772 trace_ext4_mb_new_group_pa(ac, pa);
3774 ext4_mb_use_group_pa(ac, pa);
3775 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3777 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3778 lg = ac->ac_lg;
3779 BUG_ON(lg == NULL);
3781 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3782 pa->pa_inode = NULL;
3784 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3785 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3786 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3789 * We will later add the new pa to the right bucket
3790 * after updating the pa_free in ext4_mb_release_context
3792 return 0;
3795 static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3797 int err;
3799 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3800 err = ext4_mb_new_group_pa(ac);
3801 else
3802 err = ext4_mb_new_inode_pa(ac);
3803 return err;
3807 * finds all unused blocks in on-disk bitmap, frees them in
3808 * in-core bitmap and buddy.
3809 * @pa must be unlinked from inode and group lists, so that
3810 * nobody else can find/use it.
3811 * the caller MUST hold group/inode locks.
3812 * TODO: optimize the case when there are no in-core structures yet
3814 static noinline_for_stack int
3815 ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
3816 struct ext4_prealloc_space *pa)
3818 struct super_block *sb = e4b->bd_sb;
3819 struct ext4_sb_info *sbi = EXT4_SB(sb);
3820 unsigned int end;
3821 unsigned int next;
3822 ext4_group_t group;
3823 ext4_grpblk_t bit;
3824 unsigned long long grp_blk_start;
3825 int free = 0;
3827 BUG_ON(pa->pa_deleted == 0);
3828 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3829 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
3830 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3831 end = bit + pa->pa_len;
3833 while (bit < end) {
3834 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
3835 if (bit >= end)
3836 break;
3837 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
3838 mb_debug(1, " free preallocated %u/%u in group %u\n",
3839 (unsigned) ext4_group_first_block_no(sb, group) + bit,
3840 (unsigned) next - bit, (unsigned) group);
3841 free += next - bit;
3843 trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);
3844 trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +
3845 EXT4_C2B(sbi, bit)),
3846 next - bit);
3847 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3848 bit = next + 1;
3850 if (free != pa->pa_free) {
3851 ext4_msg(e4b->bd_sb, KERN_CRIT,
3852 "pa %p: logic %lu, phys. %lu, len %lu",
3853 pa, (unsigned long) pa->pa_lstart,
3854 (unsigned long) pa->pa_pstart,
3855 (unsigned long) pa->pa_len);
3856 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
3857 free, pa->pa_free);
3859 * pa is already deleted so we use the value obtained
3860 * from the bitmap and continue.
3863 atomic_add(free, &sbi->s_mb_discarded);
3865 return 0;
3868 static noinline_for_stack int
3869 ext4_mb_release_group_pa(struct ext4_buddy *e4b,
3870 struct ext4_prealloc_space *pa)
3872 struct super_block *sb = e4b->bd_sb;
3873 ext4_group_t group;
3874 ext4_grpblk_t bit;
3876 trace_ext4_mb_release_group_pa(sb, pa);
3877 BUG_ON(pa->pa_deleted == 0);
3878 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3879 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3880 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3881 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3882 trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);
3884 return 0;
3888 * releases all preallocations in given group
3890 * first, we need to decide discard policy:
3891 * - when do we discard
3892 * 1) ENOSPC
3893 * - how many do we discard
3894 * 1) how many requested
3896 static noinline_for_stack int
3897 ext4_mb_discard_group_preallocations(struct super_block *sb,
3898 ext4_group_t group, int needed)
3900 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3901 struct buffer_head *bitmap_bh = NULL;
3902 struct ext4_prealloc_space *pa, *tmp;
3903 struct list_head list;
3904 struct ext4_buddy e4b;
3905 int err;
3906 int busy = 0;
3907 int free = 0;
3909 mb_debug(1, "discard preallocation for group %u\n", group);
3911 if (list_empty(&grp->bb_prealloc_list))
3912 return 0;
3914 bitmap_bh = ext4_read_block_bitmap(sb, group);
3915 if (IS_ERR(bitmap_bh)) {
3916 err = PTR_ERR(bitmap_bh);
3917 ext4_set_errno(sb, -err);
3918 ext4_error(sb, "Error %d reading block bitmap for %u",
3919 err, group);
3920 return 0;
3923 err = ext4_mb_load_buddy(sb, group, &e4b);
3924 if (err) {
3925 ext4_warning(sb, "Error %d loading buddy information for %u",
3926 err, group);
3927 put_bh(bitmap_bh);
3928 return 0;
3931 if (needed == 0)
3932 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
3934 INIT_LIST_HEAD(&list);
3935 repeat:
3936 ext4_lock_group(sb, group);
3937 list_for_each_entry_safe(pa, tmp,
3938 &grp->bb_prealloc_list, pa_group_list) {
3939 spin_lock(&pa->pa_lock);
3940 if (atomic_read(&pa->pa_count)) {
3941 spin_unlock(&pa->pa_lock);
3942 busy = 1;
3943 continue;
3945 if (pa->pa_deleted) {
3946 spin_unlock(&pa->pa_lock);
3947 continue;
3950 /* seems this one can be freed ... */
3951 pa->pa_deleted = 1;
3953 /* we can trust pa_free ... */
3954 free += pa->pa_free;
3956 spin_unlock(&pa->pa_lock);
3958 list_del(&pa->pa_group_list);
3959 list_add(&pa->u.pa_tmp_list, &list);
3962 /* if we still need more blocks and some PAs were used, try again */
3963 if (free < needed && busy) {
3964 busy = 0;
3965 ext4_unlock_group(sb, group);
3966 cond_resched();
3967 goto repeat;
3970 /* found anything to free? */
3971 if (list_empty(&list)) {
3972 BUG_ON(free != 0);
3973 goto out;
3976 /* now free all selected PAs */
3977 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3979 /* remove from object (inode or locality group) */
3980 spin_lock(pa->pa_obj_lock);
3981 list_del_rcu(&pa->pa_inode_list);
3982 spin_unlock(pa->pa_obj_lock);
3984 if (pa->pa_type == MB_GROUP_PA)
3985 ext4_mb_release_group_pa(&e4b, pa);
3986 else
3987 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
3989 list_del(&pa->u.pa_tmp_list);
3990 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3993 out:
3994 ext4_unlock_group(sb, group);
3995 ext4_mb_unload_buddy(&e4b);
3996 put_bh(bitmap_bh);
3997 return free;
4001 * releases all non-used preallocated blocks for given inode
4003 * It's important to discard preallocations under i_data_sem
4004 * We don't want another block to be served from the prealloc
4005 * space when we are discarding the inode prealloc space.
4007 * FIXME!! Make sure it is valid at all the call sites
4009 void ext4_discard_preallocations(struct inode *inode)
4011 struct ext4_inode_info *ei = EXT4_I(inode);
4012 struct super_block *sb = inode->i_sb;
4013 struct buffer_head *bitmap_bh = NULL;
4014 struct ext4_prealloc_space *pa, *tmp;
4015 ext4_group_t group = 0;
4016 struct list_head list;
4017 struct ext4_buddy e4b;
4018 int err;
4020 if (!S_ISREG(inode->i_mode)) {
4021 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
4022 return;
4025 mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino);
4026 trace_ext4_discard_preallocations(inode);
4028 INIT_LIST_HEAD(&list);
4030 repeat:
4031 /* first, collect all pa's in the inode */
4032 spin_lock(&ei->i_prealloc_lock);
4033 while (!list_empty(&ei->i_prealloc_list)) {
4034 pa = list_entry(ei->i_prealloc_list.next,
4035 struct ext4_prealloc_space, pa_inode_list);
4036 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
4037 spin_lock(&pa->pa_lock);
4038 if (atomic_read(&pa->pa_count)) {
4039 /* this shouldn't happen often - nobody should
4040 * use preallocation while we're discarding it */
4041 spin_unlock(&pa->pa_lock);
4042 spin_unlock(&ei->i_prealloc_lock);
4043 ext4_msg(sb, KERN_ERR,
4044 "uh-oh! used pa while discarding");
4045 WARN_ON(1);
4046 schedule_timeout_uninterruptible(HZ);
4047 goto repeat;
4050 if (pa->pa_deleted == 0) {
4051 pa->pa_deleted = 1;
4052 spin_unlock(&pa->pa_lock);
4053 list_del_rcu(&pa->pa_inode_list);
4054 list_add(&pa->u.pa_tmp_list, &list);
4055 continue;
4058 /* someone is deleting pa right now */
4059 spin_unlock(&pa->pa_lock);
4060 spin_unlock(&ei->i_prealloc_lock);
4062 /* we have to wait here because pa_deleted
4063 * doesn't mean pa is already unlinked from
4064 * the list. as we might be called from
4065 * ->clear_inode() the inode will get freed
4066 * and concurrent thread which is unlinking
4067 * pa from inode's list may access already
4068 * freed memory, bad-bad-bad */
4070 /* XXX: if this happens too often, we can
4071 * add a flag to force wait only in case
4072 * of ->clear_inode(), but not in case of
4073 * regular truncate */
4074 schedule_timeout_uninterruptible(HZ);
4075 goto repeat;
4077 spin_unlock(&ei->i_prealloc_lock);
4079 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4080 BUG_ON(pa->pa_type != MB_INODE_PA);
4081 group = ext4_get_group_number(sb, pa->pa_pstart);
4083 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4084 GFP_NOFS|__GFP_NOFAIL);
4085 if (err) {
4086 ext4_set_errno(sb, -err);
4087 ext4_error(sb, "Error %d loading buddy information for %u",
4088 err, group);
4089 continue;
4092 bitmap_bh = ext4_read_block_bitmap(sb, group);
4093 if (IS_ERR(bitmap_bh)) {
4094 err = PTR_ERR(bitmap_bh);
4095 ext4_set_errno(sb, -err);
4096 ext4_error(sb, "Error %d reading block bitmap for %u",
4097 err, group);
4098 ext4_mb_unload_buddy(&e4b);
4099 continue;
4102 ext4_lock_group(sb, group);
4103 list_del(&pa->pa_group_list);
4104 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4105 ext4_unlock_group(sb, group);
4107 ext4_mb_unload_buddy(&e4b);
4108 put_bh(bitmap_bh);
4110 list_del(&pa->u.pa_tmp_list);
4111 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4115 #ifdef CONFIG_EXT4_DEBUG
4116 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4118 struct super_block *sb = ac->ac_sb;
4119 ext4_group_t ngroups, i;
4121 if (!ext4_mballoc_debug ||
4122 (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED))
4123 return;
4125 ext4_msg(ac->ac_sb, KERN_ERR, "Can't allocate:"
4126 " Allocation context details:");
4127 ext4_msg(ac->ac_sb, KERN_ERR, "status %d flags %d",
4128 ac->ac_status, ac->ac_flags);
4129 ext4_msg(ac->ac_sb, KERN_ERR, "orig %lu/%lu/%lu@%lu, "
4130 "goal %lu/%lu/%lu@%lu, "
4131 "best %lu/%lu/%lu@%lu cr %d",
4132 (unsigned long)ac->ac_o_ex.fe_group,
4133 (unsigned long)ac->ac_o_ex.fe_start,
4134 (unsigned long)ac->ac_o_ex.fe_len,
4135 (unsigned long)ac->ac_o_ex.fe_logical,
4136 (unsigned long)ac->ac_g_ex.fe_group,
4137 (unsigned long)ac->ac_g_ex.fe_start,
4138 (unsigned long)ac->ac_g_ex.fe_len,
4139 (unsigned long)ac->ac_g_ex.fe_logical,
4140 (unsigned long)ac->ac_b_ex.fe_group,
4141 (unsigned long)ac->ac_b_ex.fe_start,
4142 (unsigned long)ac->ac_b_ex.fe_len,
4143 (unsigned long)ac->ac_b_ex.fe_logical,
4144 (int)ac->ac_criteria);
4145 ext4_msg(ac->ac_sb, KERN_ERR, "%d found", ac->ac_found);
4146 ext4_msg(ac->ac_sb, KERN_ERR, "groups: ");
4147 ngroups = ext4_get_groups_count(sb);
4148 for (i = 0; i < ngroups; i++) {
4149 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4150 struct ext4_prealloc_space *pa;
4151 ext4_grpblk_t start;
4152 struct list_head *cur;
4153 ext4_lock_group(sb, i);
4154 list_for_each(cur, &grp->bb_prealloc_list) {
4155 pa = list_entry(cur, struct ext4_prealloc_space,
4156 pa_group_list);
4157 spin_lock(&pa->pa_lock);
4158 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4159 NULL, &start);
4160 spin_unlock(&pa->pa_lock);
4161 printk(KERN_ERR "PA:%u:%d:%u \n", i,
4162 start, pa->pa_len);
4164 ext4_unlock_group(sb, i);
4166 if (grp->bb_free == 0)
4167 continue;
4168 printk(KERN_ERR "%u: %d/%d \n",
4169 i, grp->bb_free, grp->bb_fragments);
4171 printk(KERN_ERR "\n");
4173 #else
4174 static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4176 return;
4178 #endif
4181 * We use locality group preallocation for small size file. The size of the
4182 * file is determined by the current size or the resulting size after
4183 * allocation which ever is larger
4185 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
4187 static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4189 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4190 int bsbits = ac->ac_sb->s_blocksize_bits;
4191 loff_t size, isize;
4193 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4194 return;
4196 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4197 return;
4199 size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
4200 isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
4201 >> bsbits;
4203 if ((size == isize) && !ext4_fs_is_busy(sbi) &&
4204 !inode_is_open_for_write(ac->ac_inode)) {
4205 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
4206 return;
4209 if (sbi->s_mb_group_prealloc <= 0) {
4210 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4211 return;
4214 /* don't use group allocation for large files */
4215 size = max(size, isize);
4216 if (size > sbi->s_mb_stream_request) {
4217 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
4218 return;
4221 BUG_ON(ac->ac_lg != NULL);
4223 * locality group prealloc space are per cpu. The reason for having
4224 * per cpu locality group is to reduce the contention between block
4225 * request from multiple CPUs.
4227 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
4229 /* we're going to use group allocation */
4230 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4232 /* serialize all allocations in the group */
4233 mutex_lock(&ac->ac_lg->lg_mutex);
4236 static noinline_for_stack int
4237 ext4_mb_initialize_context(struct ext4_allocation_context *ac,
4238 struct ext4_allocation_request *ar)
4240 struct super_block *sb = ar->inode->i_sb;
4241 struct ext4_sb_info *sbi = EXT4_SB(sb);
4242 struct ext4_super_block *es = sbi->s_es;
4243 ext4_group_t group;
4244 unsigned int len;
4245 ext4_fsblk_t goal;
4246 ext4_grpblk_t block;
4248 /* we can't allocate > group size */
4249 len = ar->len;
4251 /* just a dirty hack to filter too big requests */
4252 if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
4253 len = EXT4_CLUSTERS_PER_GROUP(sb);
4255 /* start searching from the goal */
4256 goal = ar->goal;
4257 if (goal < le32_to_cpu(es->s_first_data_block) ||
4258 goal >= ext4_blocks_count(es))
4259 goal = le32_to_cpu(es->s_first_data_block);
4260 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4262 /* set up allocation goals */
4263 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
4264 ac->ac_status = AC_STATUS_CONTINUE;
4265 ac->ac_sb = sb;
4266 ac->ac_inode = ar->inode;
4267 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
4268 ac->ac_o_ex.fe_group = group;
4269 ac->ac_o_ex.fe_start = block;
4270 ac->ac_o_ex.fe_len = len;
4271 ac->ac_g_ex = ac->ac_o_ex;
4272 ac->ac_flags = ar->flags;
4274 /* we have to define context: we'll we work with a file or
4275 * locality group. this is a policy, actually */
4276 ext4_mb_group_or_file(ac);
4278 mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4279 "left: %u/%u, right %u/%u to %swritable\n",
4280 (unsigned) ar->len, (unsigned) ar->logical,
4281 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4282 (unsigned) ar->lleft, (unsigned) ar->pleft,
4283 (unsigned) ar->lright, (unsigned) ar->pright,
4284 inode_is_open_for_write(ar->inode) ? "" : "non-");
4285 return 0;
4289 static noinline_for_stack void
4290 ext4_mb_discard_lg_preallocations(struct super_block *sb,
4291 struct ext4_locality_group *lg,
4292 int order, int total_entries)
4294 ext4_group_t group = 0;
4295 struct ext4_buddy e4b;
4296 struct list_head discard_list;
4297 struct ext4_prealloc_space *pa, *tmp;
4299 mb_debug(1, "discard locality group preallocation\n");
4301 INIT_LIST_HEAD(&discard_list);
4303 spin_lock(&lg->lg_prealloc_lock);
4304 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
4305 pa_inode_list) {
4306 spin_lock(&pa->pa_lock);
4307 if (atomic_read(&pa->pa_count)) {
4309 * This is the pa that we just used
4310 * for block allocation. So don't
4311 * free that
4313 spin_unlock(&pa->pa_lock);
4314 continue;
4316 if (pa->pa_deleted) {
4317 spin_unlock(&pa->pa_lock);
4318 continue;
4320 /* only lg prealloc space */
4321 BUG_ON(pa->pa_type != MB_GROUP_PA);
4323 /* seems this one can be freed ... */
4324 pa->pa_deleted = 1;
4325 spin_unlock(&pa->pa_lock);
4327 list_del_rcu(&pa->pa_inode_list);
4328 list_add(&pa->u.pa_tmp_list, &discard_list);
4330 total_entries--;
4331 if (total_entries <= 5) {
4333 * we want to keep only 5 entries
4334 * allowing it to grow to 8. This
4335 * mak sure we don't call discard
4336 * soon for this list.
4338 break;
4341 spin_unlock(&lg->lg_prealloc_lock);
4343 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
4344 int err;
4346 group = ext4_get_group_number(sb, pa->pa_pstart);
4347 err = ext4_mb_load_buddy_gfp(sb, group, &e4b,
4348 GFP_NOFS|__GFP_NOFAIL);
4349 if (err) {
4350 ext4_set_errno(sb, -err);
4351 ext4_error(sb, "Error %d loading buddy information for %u",
4352 err, group);
4353 continue;
4355 ext4_lock_group(sb, group);
4356 list_del(&pa->pa_group_list);
4357 ext4_mb_release_group_pa(&e4b, pa);
4358 ext4_unlock_group(sb, group);
4360 ext4_mb_unload_buddy(&e4b);
4361 list_del(&pa->u.pa_tmp_list);
4362 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4367 * We have incremented pa_count. So it cannot be freed at this
4368 * point. Also we hold lg_mutex. So no parallel allocation is
4369 * possible from this lg. That means pa_free cannot be updated.
4371 * A parallel ext4_mb_discard_group_preallocations is possible.
4372 * which can cause the lg_prealloc_list to be updated.
4375 static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
4377 int order, added = 0, lg_prealloc_count = 1;
4378 struct super_block *sb = ac->ac_sb;
4379 struct ext4_locality_group *lg = ac->ac_lg;
4380 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
4382 order = fls(pa->pa_free) - 1;
4383 if (order > PREALLOC_TB_SIZE - 1)
4384 /* The max size of hash table is PREALLOC_TB_SIZE */
4385 order = PREALLOC_TB_SIZE - 1;
4386 /* Add the prealloc space to lg */
4387 spin_lock(&lg->lg_prealloc_lock);
4388 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
4389 pa_inode_list) {
4390 spin_lock(&tmp_pa->pa_lock);
4391 if (tmp_pa->pa_deleted) {
4392 spin_unlock(&tmp_pa->pa_lock);
4393 continue;
4395 if (!added && pa->pa_free < tmp_pa->pa_free) {
4396 /* Add to the tail of the previous entry */
4397 list_add_tail_rcu(&pa->pa_inode_list,
4398 &tmp_pa->pa_inode_list);
4399 added = 1;
4401 * we want to count the total
4402 * number of entries in the list
4405 spin_unlock(&tmp_pa->pa_lock);
4406 lg_prealloc_count++;
4408 if (!added)
4409 list_add_tail_rcu(&pa->pa_inode_list,
4410 &lg->lg_prealloc_list[order]);
4411 spin_unlock(&lg->lg_prealloc_lock);
4413 /* Now trim the list to be not more than 8 elements */
4414 if (lg_prealloc_count > 8) {
4415 ext4_mb_discard_lg_preallocations(sb, lg,
4416 order, lg_prealloc_count);
4417 return;
4419 return ;
4423 * release all resource we used in allocation
4425 static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4427 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4428 struct ext4_prealloc_space *pa = ac->ac_pa;
4429 if (pa) {
4430 if (pa->pa_type == MB_GROUP_PA) {
4431 /* see comment in ext4_mb_use_group_pa() */
4432 spin_lock(&pa->pa_lock);
4433 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4434 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4435 pa->pa_free -= ac->ac_b_ex.fe_len;
4436 pa->pa_len -= ac->ac_b_ex.fe_len;
4437 spin_unlock(&pa->pa_lock);
4440 if (pa) {
4442 * We want to add the pa to the right bucket.
4443 * Remove it from the list and while adding
4444 * make sure the list to which we are adding
4445 * doesn't grow big.
4447 if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) {
4448 spin_lock(pa->pa_obj_lock);
4449 list_del_rcu(&pa->pa_inode_list);
4450 spin_unlock(pa->pa_obj_lock);
4451 ext4_mb_add_n_trim(ac);
4453 ext4_mb_put_pa(ac, ac->ac_sb, pa);
4455 if (ac->ac_bitmap_page)
4456 put_page(ac->ac_bitmap_page);
4457 if (ac->ac_buddy_page)
4458 put_page(ac->ac_buddy_page);
4459 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4460 mutex_unlock(&ac->ac_lg->lg_mutex);
4461 ext4_mb_collect_stats(ac);
4462 return 0;
4465 static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4467 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4468 int ret;
4469 int freed = 0;
4471 trace_ext4_mb_discard_preallocations(sb, needed);
4472 for (i = 0; i < ngroups && needed > 0; i++) {
4473 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4474 freed += ret;
4475 needed -= ret;
4478 return freed;
4482 * Main entry point into mballoc to allocate blocks
4483 * it tries to use preallocation first, then falls back
4484 * to usual allocation
4486 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4487 struct ext4_allocation_request *ar, int *errp)
4489 int freed;
4490 struct ext4_allocation_context *ac = NULL;
4491 struct ext4_sb_info *sbi;
4492 struct super_block *sb;
4493 ext4_fsblk_t block = 0;
4494 unsigned int inquota = 0;
4495 unsigned int reserv_clstrs = 0;
4497 might_sleep();
4498 sb = ar->inode->i_sb;
4499 sbi = EXT4_SB(sb);
4501 trace_ext4_request_blocks(ar);
4503 /* Allow to use superuser reservation for quota file */
4504 if (ext4_is_quota_file(ar->inode))
4505 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
4507 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
4508 /* Without delayed allocation we need to verify
4509 * there is enough free blocks to do block allocation
4510 * and verify allocation doesn't exceed the quota limits.
4512 while (ar->len &&
4513 ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
4515 /* let others to free the space */
4516 cond_resched();
4517 ar->len = ar->len >> 1;
4519 if (!ar->len) {
4520 *errp = -ENOSPC;
4521 return 0;
4523 reserv_clstrs = ar->len;
4524 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
4525 dquot_alloc_block_nofail(ar->inode,
4526 EXT4_C2B(sbi, ar->len));
4527 } else {
4528 while (ar->len &&
4529 dquot_alloc_block(ar->inode,
4530 EXT4_C2B(sbi, ar->len))) {
4532 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4533 ar->len--;
4536 inquota = ar->len;
4537 if (ar->len == 0) {
4538 *errp = -EDQUOT;
4539 goto out;
4543 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
4544 if (!ac) {
4545 ar->len = 0;
4546 *errp = -ENOMEM;
4547 goto out;
4550 *errp = ext4_mb_initialize_context(ac, ar);
4551 if (*errp) {
4552 ar->len = 0;
4553 goto out;
4556 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4557 if (!ext4_mb_use_preallocated(ac)) {
4558 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4559 ext4_mb_normalize_request(ac, ar);
4560 repeat:
4561 /* allocate space in core */
4562 *errp = ext4_mb_regular_allocator(ac);
4563 if (*errp)
4564 goto discard_and_exit;
4566 /* as we've just preallocated more space than
4567 * user requested originally, we store allocated
4568 * space in a special descriptor */
4569 if (ac->ac_status == AC_STATUS_FOUND &&
4570 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4571 *errp = ext4_mb_new_preallocation(ac);
4572 if (*errp) {
4573 discard_and_exit:
4574 ext4_discard_allocated_blocks(ac);
4575 goto errout;
4578 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
4579 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
4580 if (*errp) {
4581 ext4_discard_allocated_blocks(ac);
4582 goto errout;
4583 } else {
4584 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4585 ar->len = ac->ac_b_ex.fe_len;
4587 } else {
4588 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
4589 if (freed)
4590 goto repeat;
4591 *errp = -ENOSPC;
4594 errout:
4595 if (*errp) {
4596 ac->ac_b_ex.fe_len = 0;
4597 ar->len = 0;
4598 ext4_mb_show_ac(ac);
4600 ext4_mb_release_context(ac);
4601 out:
4602 if (ac)
4603 kmem_cache_free(ext4_ac_cachep, ac);
4604 if (inquota && ar->len < inquota)
4605 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
4606 if (!ar->len) {
4607 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
4608 /* release all the reserved blocks if non delalloc */
4609 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
4610 reserv_clstrs);
4613 trace_ext4_allocate_blocks(ar, (unsigned long long)block);
4615 return block;
4619 * We can merge two free data extents only if the physical blocks
4620 * are contiguous, AND the extents were freed by the same transaction,
4621 * AND the blocks are associated with the same group.
4623 static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
4624 struct ext4_free_data *entry,
4625 struct ext4_free_data *new_entry,
4626 struct rb_root *entry_rb_root)
4628 if ((entry->efd_tid != new_entry->efd_tid) ||
4629 (entry->efd_group != new_entry->efd_group))
4630 return;
4631 if (entry->efd_start_cluster + entry->efd_count ==
4632 new_entry->efd_start_cluster) {
4633 new_entry->efd_start_cluster = entry->efd_start_cluster;
4634 new_entry->efd_count += entry->efd_count;
4635 } else if (new_entry->efd_start_cluster + new_entry->efd_count ==
4636 entry->efd_start_cluster) {
4637 new_entry->efd_count += entry->efd_count;
4638 } else
4639 return;
4640 spin_lock(&sbi->s_md_lock);
4641 list_del(&entry->efd_list);
4642 spin_unlock(&sbi->s_md_lock);
4643 rb_erase(&entry->efd_node, entry_rb_root);
4644 kmem_cache_free(ext4_free_data_cachep, entry);
4647 static noinline_for_stack int
4648 ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
4649 struct ext4_free_data *new_entry)
4651 ext4_group_t group = e4b->bd_group;
4652 ext4_grpblk_t cluster;
4653 ext4_grpblk_t clusters = new_entry->efd_count;
4654 struct ext4_free_data *entry;
4655 struct ext4_group_info *db = e4b->bd_info;
4656 struct super_block *sb = e4b->bd_sb;
4657 struct ext4_sb_info *sbi = EXT4_SB(sb);
4658 struct rb_node **n = &db->bb_free_root.rb_node, *node;
4659 struct rb_node *parent = NULL, *new_node;
4661 BUG_ON(!ext4_handle_valid(handle));
4662 BUG_ON(e4b->bd_bitmap_page == NULL);
4663 BUG_ON(e4b->bd_buddy_page == NULL);
4665 new_node = &new_entry->efd_node;
4666 cluster = new_entry->efd_start_cluster;
4668 if (!*n) {
4669 /* first free block exent. We need to
4670 protect buddy cache from being freed,
4671 * otherwise we'll refresh it from
4672 * on-disk bitmap and lose not-yet-available
4673 * blocks */
4674 get_page(e4b->bd_buddy_page);
4675 get_page(e4b->bd_bitmap_page);
4677 while (*n) {
4678 parent = *n;
4679 entry = rb_entry(parent, struct ext4_free_data, efd_node);
4680 if (cluster < entry->efd_start_cluster)
4681 n = &(*n)->rb_left;
4682 else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
4683 n = &(*n)->rb_right;
4684 else {
4685 ext4_grp_locked_error(sb, group, 0,
4686 ext4_group_first_block_no(sb, group) +
4687 EXT4_C2B(sbi, cluster),
4688 "Block already on to-be-freed list");
4689 return 0;
4693 rb_link_node(new_node, parent, n);
4694 rb_insert_color(new_node, &db->bb_free_root);
4696 /* Now try to see the extent can be merged to left and right */
4697 node = rb_prev(new_node);
4698 if (node) {
4699 entry = rb_entry(node, struct ext4_free_data, efd_node);
4700 ext4_try_merge_freed_extent(sbi, entry, new_entry,
4701 &(db->bb_free_root));
4704 node = rb_next(new_node);
4705 if (node) {
4706 entry = rb_entry(node, struct ext4_free_data, efd_node);
4707 ext4_try_merge_freed_extent(sbi, entry, new_entry,
4708 &(db->bb_free_root));
4711 spin_lock(&sbi->s_md_lock);
4712 list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list);
4713 sbi->s_mb_free_pending += clusters;
4714 spin_unlock(&sbi->s_md_lock);
4715 return 0;
4719 * ext4_free_blocks() -- Free given blocks and update quota
4720 * @handle: handle for this transaction
4721 * @inode: inode
4722 * @bh: optional buffer of the block to be freed
4723 * @block: starting physical block to be freed
4724 * @count: number of blocks to be freed
4725 * @flags: flags used by ext4_free_blocks
4727 void ext4_free_blocks(handle_t *handle, struct inode *inode,
4728 struct buffer_head *bh, ext4_fsblk_t block,
4729 unsigned long count, int flags)
4731 struct buffer_head *bitmap_bh = NULL;
4732 struct super_block *sb = inode->i_sb;
4733 struct ext4_group_desc *gdp;
4734 unsigned int overflow;
4735 ext4_grpblk_t bit;
4736 struct buffer_head *gd_bh;
4737 ext4_group_t block_group;
4738 struct ext4_sb_info *sbi;
4739 struct ext4_buddy e4b;
4740 unsigned int count_clusters;
4741 int err = 0;
4742 int ret;
4744 might_sleep();
4745 if (bh) {
4746 if (block)
4747 BUG_ON(block != bh->b_blocknr);
4748 else
4749 block = bh->b_blocknr;
4752 sbi = EXT4_SB(sb);
4753 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
4754 !ext4_data_block_valid(sbi, block, count)) {
4755 ext4_error(sb, "Freeing blocks not in datazone - "
4756 "block = %llu, count = %lu", block, count);
4757 goto error_return;
4760 ext4_debug("freeing block %llu\n", block);
4761 trace_ext4_free_blocks(inode, block, count, flags);
4763 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
4764 BUG_ON(count > 1);
4766 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
4767 inode, bh, block);
4771 * If the extent to be freed does not begin on a cluster
4772 * boundary, we need to deal with partial clusters at the
4773 * beginning and end of the extent. Normally we will free
4774 * blocks at the beginning or the end unless we are explicitly
4775 * requested to avoid doing so.
4777 overflow = EXT4_PBLK_COFF(sbi, block);
4778 if (overflow) {
4779 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
4780 overflow = sbi->s_cluster_ratio - overflow;
4781 block += overflow;
4782 if (count > overflow)
4783 count -= overflow;
4784 else
4785 return;
4786 } else {
4787 block -= overflow;
4788 count += overflow;
4791 overflow = EXT4_LBLK_COFF(sbi, count);
4792 if (overflow) {
4793 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
4794 if (count > overflow)
4795 count -= overflow;
4796 else
4797 return;
4798 } else
4799 count += sbi->s_cluster_ratio - overflow;
4802 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
4803 int i;
4804 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
4806 for (i = 0; i < count; i++) {
4807 cond_resched();
4808 if (is_metadata)
4809 bh = sb_find_get_block(inode->i_sb, block + i);
4810 ext4_forget(handle, is_metadata, inode, bh, block + i);
4814 do_more:
4815 overflow = 0;
4816 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4818 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(
4819 ext4_get_group_info(sb, block_group))))
4820 return;
4823 * Check to see if we are freeing blocks across a group
4824 * boundary.
4826 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4827 overflow = EXT4_C2B(sbi, bit) + count -
4828 EXT4_BLOCKS_PER_GROUP(sb);
4829 count -= overflow;
4831 count_clusters = EXT4_NUM_B2C(sbi, count);
4832 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
4833 if (IS_ERR(bitmap_bh)) {
4834 err = PTR_ERR(bitmap_bh);
4835 bitmap_bh = NULL;
4836 goto error_return;
4838 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
4839 if (!gdp) {
4840 err = -EIO;
4841 goto error_return;
4844 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4845 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4846 in_range(block, ext4_inode_table(sb, gdp),
4847 sbi->s_itb_per_group) ||
4848 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4849 sbi->s_itb_per_group)) {
4851 ext4_error(sb, "Freeing blocks in system zone - "
4852 "Block = %llu, count = %lu", block, count);
4853 /* err = 0. ext4_std_error should be a no op */
4854 goto error_return;
4857 BUFFER_TRACE(bitmap_bh, "getting write access");
4858 err = ext4_journal_get_write_access(handle, bitmap_bh);
4859 if (err)
4860 goto error_return;
4863 * We are about to modify some metadata. Call the journal APIs
4864 * to unshare ->b_data if a currently-committing transaction is
4865 * using it
4867 BUFFER_TRACE(gd_bh, "get_write_access");
4868 err = ext4_journal_get_write_access(handle, gd_bh);
4869 if (err)
4870 goto error_return;
4871 #ifdef AGGRESSIVE_CHECK
4873 int i;
4874 for (i = 0; i < count_clusters; i++)
4875 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4877 #endif
4878 trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters);
4880 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
4881 err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b,
4882 GFP_NOFS|__GFP_NOFAIL);
4883 if (err)
4884 goto error_return;
4887 * We need to make sure we don't reuse the freed block until after the
4888 * transaction is committed. We make an exception if the inode is to be
4889 * written in writeback mode since writeback mode has weak data
4890 * consistency guarantees.
4892 if (ext4_handle_valid(handle) &&
4893 ((flags & EXT4_FREE_BLOCKS_METADATA) ||
4894 !ext4_should_writeback_data(inode))) {
4895 struct ext4_free_data *new_entry;
4897 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
4898 * to fail.
4900 new_entry = kmem_cache_alloc(ext4_free_data_cachep,
4901 GFP_NOFS|__GFP_NOFAIL);
4902 new_entry->efd_start_cluster = bit;
4903 new_entry->efd_group = block_group;
4904 new_entry->efd_count = count_clusters;
4905 new_entry->efd_tid = handle->h_transaction->t_tid;
4907 ext4_lock_group(sb, block_group);
4908 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
4909 ext4_mb_free_metadata(handle, &e4b, new_entry);
4910 } else {
4911 /* need to update group_info->bb_free and bitmap
4912 * with group lock held. generate_buddy look at
4913 * them with group lock_held
4915 if (test_opt(sb, DISCARD)) {
4916 err = ext4_issue_discard(sb, block_group, bit, count,
4917 NULL);
4918 if (err && err != -EOPNOTSUPP)
4919 ext4_msg(sb, KERN_WARNING, "discard request in"
4920 " group:%d block:%d count:%lu failed"
4921 " with %d", block_group, bit, count,
4922 err);
4923 } else
4924 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
4926 ext4_lock_group(sb, block_group);
4927 mb_clear_bits(bitmap_bh->b_data, bit, count_clusters);
4928 mb_free_blocks(inode, &e4b, bit, count_clusters);
4931 ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
4932 ext4_free_group_clusters_set(sb, gdp, ret);
4933 ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
4934 ext4_group_desc_csum_set(sb, block_group, gdp);
4935 ext4_unlock_group(sb, block_group);
4937 if (sbi->s_log_groups_per_flex) {
4938 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
4939 atomic64_add(count_clusters,
4940 &sbi_array_rcu_deref(sbi, s_flex_groups,
4941 flex_group)->free_clusters);
4945 * on a bigalloc file system, defer the s_freeclusters_counter
4946 * update to the caller (ext4_remove_space and friends) so they
4947 * can determine if a cluster freed here should be rereserved
4949 if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
4950 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
4951 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
4952 percpu_counter_add(&sbi->s_freeclusters_counter,
4953 count_clusters);
4956 ext4_mb_unload_buddy(&e4b);
4958 /* We dirtied the bitmap block */
4959 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4960 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
4962 /* And the group descriptor block */
4963 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4964 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
4965 if (!err)
4966 err = ret;
4968 if (overflow && !err) {
4969 block += count;
4970 count = overflow;
4971 put_bh(bitmap_bh);
4972 goto do_more;
4974 error_return:
4975 brelse(bitmap_bh);
4976 ext4_std_error(sb, err);
4977 return;
4981 * ext4_group_add_blocks() -- Add given blocks to an existing group
4982 * @handle: handle to this transaction
4983 * @sb: super block
4984 * @block: start physical block to add to the block group
4985 * @count: number of blocks to free
4987 * This marks the blocks as free in the bitmap and buddy.
4989 int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
4990 ext4_fsblk_t block, unsigned long count)
4992 struct buffer_head *bitmap_bh = NULL;
4993 struct buffer_head *gd_bh;
4994 ext4_group_t block_group;
4995 ext4_grpblk_t bit;
4996 unsigned int i;
4997 struct ext4_group_desc *desc;
4998 struct ext4_sb_info *sbi = EXT4_SB(sb);
4999 struct ext4_buddy e4b;
5000 int err = 0, ret, free_clusters_count;
5001 ext4_grpblk_t clusters_freed;
5002 ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
5003 ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
5004 unsigned long cluster_count = last_cluster - first_cluster + 1;
5006 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
5008 if (count == 0)
5009 return 0;
5011 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
5013 * Check to see if we are freeing blocks across a group
5014 * boundary.
5016 if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
5017 ext4_warning(sb, "too many blocks added to group %u",
5018 block_group);
5019 err = -EINVAL;
5020 goto error_return;
5023 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
5024 if (IS_ERR(bitmap_bh)) {
5025 err = PTR_ERR(bitmap_bh);
5026 bitmap_bh = NULL;
5027 goto error_return;
5030 desc = ext4_get_group_desc(sb, block_group, &gd_bh);
5031 if (!desc) {
5032 err = -EIO;
5033 goto error_return;
5036 if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
5037 in_range(ext4_inode_bitmap(sb, desc), block, count) ||
5038 in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
5039 in_range(block + count - 1, ext4_inode_table(sb, desc),
5040 sbi->s_itb_per_group)) {
5041 ext4_error(sb, "Adding blocks in system zones - "
5042 "Block = %llu, count = %lu",
5043 block, count);
5044 err = -EINVAL;
5045 goto error_return;
5048 BUFFER_TRACE(bitmap_bh, "getting write access");
5049 err = ext4_journal_get_write_access(handle, bitmap_bh);
5050 if (err)
5051 goto error_return;
5054 * We are about to modify some metadata. Call the journal APIs
5055 * to unshare ->b_data if a currently-committing transaction is
5056 * using it
5058 BUFFER_TRACE(gd_bh, "get_write_access");
5059 err = ext4_journal_get_write_access(handle, gd_bh);
5060 if (err)
5061 goto error_return;
5063 for (i = 0, clusters_freed = 0; i < cluster_count; i++) {
5064 BUFFER_TRACE(bitmap_bh, "clear bit");
5065 if (!mb_test_bit(bit + i, bitmap_bh->b_data)) {
5066 ext4_error(sb, "bit already cleared for block %llu",
5067 (ext4_fsblk_t)(block + i));
5068 BUFFER_TRACE(bitmap_bh, "bit already cleared");
5069 } else {
5070 clusters_freed++;
5074 err = ext4_mb_load_buddy(sb, block_group, &e4b);
5075 if (err)
5076 goto error_return;
5079 * need to update group_info->bb_free and bitmap
5080 * with group lock held. generate_buddy look at
5081 * them with group lock_held
5083 ext4_lock_group(sb, block_group);
5084 mb_clear_bits(bitmap_bh->b_data, bit, cluster_count);
5085 mb_free_blocks(NULL, &e4b, bit, cluster_count);
5086 free_clusters_count = clusters_freed +
5087 ext4_free_group_clusters(sb, desc);
5088 ext4_free_group_clusters_set(sb, desc, free_clusters_count);
5089 ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
5090 ext4_group_desc_csum_set(sb, block_group, desc);
5091 ext4_unlock_group(sb, block_group);
5092 percpu_counter_add(&sbi->s_freeclusters_counter,
5093 clusters_freed);
5095 if (sbi->s_log_groups_per_flex) {
5096 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
5097 atomic64_add(clusters_freed,
5098 &sbi_array_rcu_deref(sbi, s_flex_groups,
5099 flex_group)->free_clusters);
5102 ext4_mb_unload_buddy(&e4b);
5104 /* We dirtied the bitmap block */
5105 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
5106 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
5108 /* And the group descriptor block */
5109 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
5110 ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
5111 if (!err)
5112 err = ret;
5114 error_return:
5115 brelse(bitmap_bh);
5116 ext4_std_error(sb, err);
5117 return err;
5121 * ext4_trim_extent -- function to TRIM one single free extent in the group
5122 * @sb: super block for the file system
5123 * @start: starting block of the free extent in the alloc. group
5124 * @count: number of blocks to TRIM
5125 * @group: alloc. group we are working with
5126 * @e4b: ext4 buddy for the group
5128 * Trim "count" blocks starting at "start" in the "group". To assure that no
5129 * one will allocate those blocks, mark it as used in buddy bitmap. This must
5130 * be called with under the group lock.
5132 static int ext4_trim_extent(struct super_block *sb, int start, int count,
5133 ext4_group_t group, struct ext4_buddy *e4b)
5134 __releases(bitlock)
5135 __acquires(bitlock)
5137 struct ext4_free_extent ex;
5138 int ret = 0;
5140 trace_ext4_trim_extent(sb, group, start, count);
5142 assert_spin_locked(ext4_group_lock_ptr(sb, group));
5144 ex.fe_start = start;
5145 ex.fe_group = group;
5146 ex.fe_len = count;
5149 * Mark blocks used, so no one can reuse them while
5150 * being trimmed.
5152 mb_mark_used(e4b, &ex);
5153 ext4_unlock_group(sb, group);
5154 ret = ext4_issue_discard(sb, group, start, count, NULL);
5155 ext4_lock_group(sb, group);
5156 mb_free_blocks(NULL, e4b, start, ex.fe_len);
5157 return ret;
5161 * ext4_trim_all_free -- function to trim all free space in alloc. group
5162 * @sb: super block for file system
5163 * @group: group to be trimmed
5164 * @start: first group block to examine
5165 * @max: last group block to examine
5166 * @minblocks: minimum extent block count
5168 * ext4_trim_all_free walks through group's buddy bitmap searching for free
5169 * extents. When the free block is found, ext4_trim_extent is called to TRIM
5170 * the extent.
5173 * ext4_trim_all_free walks through group's block bitmap searching for free
5174 * extents. When the free extent is found, mark it as used in group buddy
5175 * bitmap. Then issue a TRIM command on this extent and free the extent in
5176 * the group buddy bitmap. This is done until whole group is scanned.
5178 static ext4_grpblk_t
5179 ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
5180 ext4_grpblk_t start, ext4_grpblk_t max,
5181 ext4_grpblk_t minblocks)
5183 void *bitmap;
5184 ext4_grpblk_t next, count = 0, free_count = 0;
5185 struct ext4_buddy e4b;
5186 int ret = 0;
5188 trace_ext4_trim_all_free(sb, group, start, max);
5190 ret = ext4_mb_load_buddy(sb, group, &e4b);
5191 if (ret) {
5192 ext4_warning(sb, "Error %d loading buddy information for %u",
5193 ret, group);
5194 return ret;
5196 bitmap = e4b.bd_bitmap;
5198 ext4_lock_group(sb, group);
5199 if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
5200 minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
5201 goto out;
5203 start = (e4b.bd_info->bb_first_free > start) ?
5204 e4b.bd_info->bb_first_free : start;
5206 while (start <= max) {
5207 start = mb_find_next_zero_bit(bitmap, max + 1, start);
5208 if (start > max)
5209 break;
5210 next = mb_find_next_bit(bitmap, max + 1, start);
5212 if ((next - start) >= minblocks) {
5213 ret = ext4_trim_extent(sb, start,
5214 next - start, group, &e4b);
5215 if (ret && ret != -EOPNOTSUPP)
5216 break;
5217 ret = 0;
5218 count += next - start;
5220 free_count += next - start;
5221 start = next + 1;
5223 if (fatal_signal_pending(current)) {
5224 count = -ERESTARTSYS;
5225 break;
5228 if (need_resched()) {
5229 ext4_unlock_group(sb, group);
5230 cond_resched();
5231 ext4_lock_group(sb, group);
5234 if ((e4b.bd_info->bb_free - free_count) < minblocks)
5235 break;
5238 if (!ret) {
5239 ret = count;
5240 EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
5242 out:
5243 ext4_unlock_group(sb, group);
5244 ext4_mb_unload_buddy(&e4b);
5246 ext4_debug("trimmed %d blocks in the group %d\n",
5247 count, group);
5249 return ret;
5253 * ext4_trim_fs() -- trim ioctl handle function
5254 * @sb: superblock for filesystem
5255 * @range: fstrim_range structure
5257 * start: First Byte to trim
5258 * len: number of Bytes to trim from start
5259 * minlen: minimum extent length in Bytes
5260 * ext4_trim_fs goes through all allocation groups containing Bytes from
5261 * start to start+len. For each such a group ext4_trim_all_free function
5262 * is invoked to trim all free space.
5264 int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
5266 struct ext4_group_info *grp;
5267 ext4_group_t group, first_group, last_group;
5268 ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
5269 uint64_t start, end, minlen, trimmed = 0;
5270 ext4_fsblk_t first_data_blk =
5271 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
5272 ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es);
5273 int ret = 0;
5275 start = range->start >> sb->s_blocksize_bits;
5276 end = start + (range->len >> sb->s_blocksize_bits) - 1;
5277 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
5278 range->minlen >> sb->s_blocksize_bits);
5280 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
5281 start >= max_blks ||
5282 range->len < sb->s_blocksize)
5283 return -EINVAL;
5284 if (end >= max_blks)
5285 end = max_blks - 1;
5286 if (end <= first_data_blk)
5287 goto out;
5288 if (start < first_data_blk)
5289 start = first_data_blk;
5291 /* Determine first and last group to examine based on start and end */
5292 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start,
5293 &first_group, &first_cluster);
5294 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end,
5295 &last_group, &last_cluster);
5297 /* end now represents the last cluster to discard in this group */
5298 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5300 for (group = first_group; group <= last_group; group++) {
5301 grp = ext4_get_group_info(sb, group);
5302 /* We only do this if the grp has never been initialized */
5303 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
5304 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
5305 if (ret)
5306 break;
5310 * For all the groups except the last one, last cluster will
5311 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
5312 * change it for the last group, note that last_cluster is
5313 * already computed earlier by ext4_get_group_no_and_offset()
5315 if (group == last_group)
5316 end = last_cluster;
5318 if (grp->bb_free >= minlen) {
5319 cnt = ext4_trim_all_free(sb, group, first_cluster,
5320 end, minlen);
5321 if (cnt < 0) {
5322 ret = cnt;
5323 break;
5325 trimmed += cnt;
5329 * For every group except the first one, we are sure
5330 * that the first cluster to discard will be cluster #0.
5332 first_cluster = 0;
5335 if (!ret)
5336 atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
5338 out:
5339 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
5340 return ret;
5343 /* Iterate all the free extents in the group. */
5345 ext4_mballoc_query_range(
5346 struct super_block *sb,
5347 ext4_group_t group,
5348 ext4_grpblk_t start,
5349 ext4_grpblk_t end,
5350 ext4_mballoc_query_range_fn formatter,
5351 void *priv)
5353 void *bitmap;
5354 ext4_grpblk_t next;
5355 struct ext4_buddy e4b;
5356 int error;
5358 error = ext4_mb_load_buddy(sb, group, &e4b);
5359 if (error)
5360 return error;
5361 bitmap = e4b.bd_bitmap;
5363 ext4_lock_group(sb, group);
5365 start = (e4b.bd_info->bb_first_free > start) ?
5366 e4b.bd_info->bb_first_free : start;
5367 if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
5368 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
5370 while (start <= end) {
5371 start = mb_find_next_zero_bit(bitmap, end + 1, start);
5372 if (start > end)
5373 break;
5374 next = mb_find_next_bit(bitmap, end + 1, start);
5376 ext4_unlock_group(sb, group);
5377 error = formatter(sb, group, start, next - start, priv);
5378 if (error)
5379 goto out_unload;
5380 ext4_lock_group(sb, group);
5382 start = next + 1;
5385 ext4_unlock_group(sb, group);
5386 out_unload:
5387 ext4_mb_unload_buddy(&e4b);
5389 return error;