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 */
6
7
8/*
9 * mballoc.c contains the multiblocks allocation routines
10 */
11
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 <linux/freezer.h>
20#include <trace/events/ext4.h>
21#include <kunit/static_stub.h>
22
23/*
24 * MUSTDO:
25 * - test ext4_ext_search_left() and ext4_ext_search_right()
26 * - search for metadata in few groups
27 *
28 * TODO v4:
29 * - normalization should take into account whether file is still open
30 * - discard preallocations if no free space left (policy?)
31 * - don't normalize tails
32 * - quota
33 * - reservation for superuser
34 *
35 * TODO v3:
36 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
37 * - track min/max extents in each group for better group selection
38 * - mb_mark_used() may allocate chunk right after splitting buddy
39 * - tree of groups sorted by number of free blocks
40 * - error handling
41 */
42
43/*
44 * The allocation request involve request for multiple number of blocks
45 * near to the goal(block) value specified.
46 *
47 * During initialization phase of the allocator we decide to use the
48 * group preallocation or inode preallocation depending on the size of
49 * the file. The size of the file could be the resulting file size we
50 * would have after allocation, or the current file size, which ever
51 * is larger. If the size is less than sbi->s_mb_stream_request we
52 * select to use the group preallocation. The default value of
53 * s_mb_stream_request is 16 blocks. This can also be tuned via
54 * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
55 * terms of number of blocks.
56 *
57 * The main motivation for having small file use group preallocation is to
58 * ensure that we have small files closer together on the disk.
59 *
60 * First stage the allocator looks at the inode prealloc list,
61 * ext4_inode_info->i_prealloc_list, which contains list of prealloc
62 * spaces for this particular inode. The inode prealloc space is
63 * represented as:
64 *
65 * pa_lstart -> the logical start block for this prealloc space
66 * pa_pstart -> the physical start block for this prealloc space
67 * pa_len -> length for this prealloc space (in clusters)
68 * pa_free -> free space available in this prealloc space (in clusters)
69 *
70 * The inode preallocation space is used looking at the _logical_ start
71 * block. If only the logical file block falls within the range of prealloc
72 * space we will consume the particular prealloc space. This makes sure that
73 * we have contiguous physical blocks representing the file blocks
74 *
75 * The important thing to be noted in case of inode prealloc space is that
76 * we don't modify the values associated to inode prealloc space except
77 * pa_free.
78 *
79 * If we are not able to find blocks in the inode prealloc space and if we
80 * have the group allocation flag set then we look at the locality group
81 * prealloc space. These are per CPU prealloc list represented as
82 *
83 * ext4_sb_info.s_locality_groups[smp_processor_id()]
84 *
85 * The reason for having a per cpu locality group is to reduce the contention
86 * between CPUs. It is possible to get scheduled at this point.
87 *
88 * The locality group prealloc space is used looking at whether we have
89 * enough free space (pa_free) within the prealloc space.
90 *
91 * If we can't allocate blocks via inode prealloc or/and locality group
92 * prealloc then we look at the buddy cache. The buddy cache is represented
93 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
94 * mapped to the buddy and bitmap information regarding different
95 * groups. The buddy information is attached to buddy cache inode so that
96 * we can access them through the page cache. The information regarding
97 * each group is loaded via ext4_mb_load_buddy. The information involve
98 * block bitmap and buddy information. The information are stored in the
99 * inode as:
100 *
101 * { page }
102 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
103 *
104 *
105 * one block each for bitmap and buddy information. So for each group we
106 * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
107 * blocksize) blocks. So it can have information regarding groups_per_page
108 * which is blocks_per_page/2
109 *
110 * The buddy cache inode is not stored on disk. The inode is thrown
111 * away when the filesystem is unmounted.
112 *
113 * We look for count number of blocks in the buddy cache. If we were able
114 * to locate that many free blocks we return with additional information
115 * regarding rest of the contiguous physical block available
116 *
117 * Before allocating blocks via buddy cache we normalize the request
118 * blocks. This ensure we ask for more blocks that we needed. The extra
119 * blocks that we get after allocation is added to the respective prealloc
120 * list. In case of inode preallocation we follow a list of heuristics
121 * based on file size. This can be found in ext4_mb_normalize_request. If
122 * we are doing a group prealloc we try to normalize the request to
123 * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
124 * dependent on the cluster size; for non-bigalloc file systems, it is
125 * 512 blocks. This can be tuned via
126 * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
127 * terms of number of blocks. If we have mounted the file system with -O
128 * stripe=<value> option the group prealloc request is normalized to the
129 * smallest multiple of the stripe value (sbi->s_stripe) which is
130 * greater than the default mb_group_prealloc.
131 *
132 * If "mb_optimize_scan" mount option is set, we maintain in memory group info
133 * structures in two data structures:
134 *
135 * 1) Array of largest free order xarrays (sbi->s_mb_largest_free_orders)
136 *
137 * Locking: Writers use xa_lock, readers use rcu_read_lock.
138 *
139 * This is an array of xarrays where the index in the array represents the
140 * largest free order in the buddy bitmap of the participating group infos of
141 * that xarray. So, there are exactly MB_NUM_ORDERS(sb) (which means total
142 * number of buddy bitmap orders possible) number of xarrays. Group-infos are
143 * placed in appropriate xarrays.
144 *
145 * 2) Average fragment size xarrays (sbi->s_mb_avg_fragment_size)
146 *
147 * Locking: Writers use xa_lock, readers use rcu_read_lock.
148 *
149 * This is an array of xarrays where in the i-th xarray there are groups with
150 * average fragment size >= 2^i and < 2^(i+1). The average fragment size
151 * is computed as ext4_group_info->bb_free / ext4_group_info->bb_fragments.
152 * Note that we don't bother with a special xarray for completely empty
153 * groups so we only have MB_NUM_ORDERS(sb) xarrays. Group-infos are placed
154 * in appropriate xarrays.
155 *
156 * In xarray, the index is the block group number, the value is the block group
157 * information, and a non-empty value indicates the block group is present in
158 * the current xarray.
159 *
160 * When "mb_optimize_scan" mount option is set, mballoc consults the above data
161 * structures to decide the order in which groups are to be traversed for
162 * fulfilling an allocation request.
163 *
164 * At CR_POWER2_ALIGNED , we look for groups which have the largest_free_order
165 * >= the order of the request. We directly look at the largest free order list
166 * in the data structure (1) above where largest_free_order = order of the
167 * request. If that list is empty, we look at remaining list in the increasing
168 * order of largest_free_order. This allows us to perform CR_POWER2_ALIGNED
169 * lookup in O(1) time.
170 *
171 * At CR_GOAL_LEN_FAST, we only consider groups where
172 * average fragment size > request size. So, we lookup a group which has average
173 * fragment size just above or equal to request size using our average fragment
174 * size group lists (data structure 2) in O(1) time.
175 *
176 * At CR_BEST_AVAIL_LEN, we aim to optimize allocations which can't be satisfied
177 * in CR_GOAL_LEN_FAST. The fact that we couldn't find a group in
178 * CR_GOAL_LEN_FAST suggests that there is no BG that has avg
179 * fragment size > goal length. So before falling to the slower
180 * CR_GOAL_LEN_SLOW, in CR_BEST_AVAIL_LEN we proactively trim goal length and
181 * then use the same fragment lists as CR_GOAL_LEN_FAST to find a BG with a big
182 * enough average fragment size. This increases the chances of finding a
183 * suitable block group in O(1) time and results in faster allocation at the
184 * cost of reduced size of allocation.
185 *
186 * If "mb_optimize_scan" mount option is not set, mballoc traverses groups in
187 * linear order which requires O(N) search time for each CR_POWER2_ALIGNED and
188 * CR_GOAL_LEN_FAST phase.
189 *
190 * The regular allocator (using the buddy cache) supports a few tunables.
191 *
192 * /sys/fs/ext4/<partition>/mb_min_to_scan
193 * /sys/fs/ext4/<partition>/mb_max_to_scan
194 * /sys/fs/ext4/<partition>/mb_order2_req
195 * /sys/fs/ext4/<partition>/mb_max_linear_groups
196 *
197 * The regular allocator uses buddy scan only if the request len is power of
198 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
199 * value of s_mb_order2_reqs can be tuned via
200 * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
201 * stripe size (sbi->s_stripe), we try to search for contiguous block in
202 * stripe size. This should result in better allocation on RAID setups. If
203 * not, we search in the specific group using bitmap for best extents. The
204 * tunable min_to_scan and max_to_scan control the behaviour here.
205 * min_to_scan indicate how long the mballoc __must__ look for a best
206 * extent and max_to_scan indicates how long the mballoc __can__ look for a
207 * best extent in the found extents. Searching for the blocks starts with
208 * the group specified as the goal value in allocation context via
209 * ac_g_ex. Each group is first checked based on the criteria whether it
210 * can be used for allocation. ext4_mb_good_group explains how the groups are
211 * checked.
212 *
213 * When "mb_optimize_scan" is turned on, as mentioned above, the groups may not
214 * get traversed linearly. That may result in subsequent allocations being not
215 * close to each other. And so, the underlying device may get filled up in a
216 * non-linear fashion. While that may not matter on non-rotational devices, for
217 * rotational devices that may result in higher seek times. "mb_max_linear_groups"
218 * tells mballoc how many groups mballoc should search linearly before
219 * performing consulting above data structures for more efficient lookups. For
220 * non rotational devices, this value defaults to 0 and for rotational devices
221 * this is set to MB_DEFAULT_LINEAR_LIMIT.
222 *
223 * Both the prealloc space are getting populated as above. So for the first
224 * request we will hit the buddy cache which will result in this prealloc
225 * space getting filled. The prealloc space is then later used for the
226 * subsequent request.
227 */
228
229/*
230 * mballoc operates on the following data:
231 * - on-disk bitmap
232 * - in-core buddy (actually includes buddy and bitmap)
233 * - preallocation descriptors (PAs)
234 *
235 * there are two types of preallocations:
236 * - inode
237 * assiged to specific inode and can be used for this inode only.
238 * it describes part of inode's space preallocated to specific
239 * physical blocks. any block from that preallocated can be used
240 * independent. the descriptor just tracks number of blocks left
241 * unused. so, before taking some block from descriptor, one must
242 * make sure corresponded logical block isn't allocated yet. this
243 * also means that freeing any block within descriptor's range
244 * must discard all preallocated blocks.
245 * - locality group
246 * assigned to specific locality group which does not translate to
247 * permanent set of inodes: inode can join and leave group. space
248 * from this type of preallocation can be used for any inode. thus
249 * it's consumed from the beginning to the end.
250 *
251 * relation between them can be expressed as:
252 * in-core buddy = on-disk bitmap + preallocation descriptors
253 *
254 * this mean blocks mballoc considers used are:
255 * - allocated blocks (persistent)
256 * - preallocated blocks (non-persistent)
257 *
258 * consistency in mballoc world means that at any time a block is either
259 * free or used in ALL structures. notice: "any time" should not be read
260 * literally -- time is discrete and delimited by locks.
261 *
262 * to keep it simple, we don't use block numbers, instead we count number of
263 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
264 *
265 * all operations can be expressed as:
266 * - init buddy: buddy = on-disk + PAs
267 * - new PA: buddy += N; PA = N
268 * - use inode PA: on-disk += N; PA -= N
269 * - discard inode PA buddy -= on-disk - PA; PA = 0
270 * - use locality group PA on-disk += N; PA -= N
271 * - discard locality group PA buddy -= PA; PA = 0
272 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
273 * is used in real operation because we can't know actual used
274 * bits from PA, only from on-disk bitmap
275 *
276 * if we follow this strict logic, then all operations above should be atomic.
277 * given some of them can block, we'd have to use something like semaphores
278 * killing performance on high-end SMP hardware. let's try to relax it using
279 * the following knowledge:
280 * 1) if buddy is referenced, it's already initialized
281 * 2) while block is used in buddy and the buddy is referenced,
282 * nobody can re-allocate that block
283 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
284 * bit set and PA claims same block, it's OK. IOW, one can set bit in
285 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
286 * block
287 *
288 * so, now we're building a concurrency table:
289 * - init buddy vs.
290 * - new PA
291 * blocks for PA are allocated in the buddy, buddy must be referenced
292 * until PA is linked to allocation group to avoid concurrent buddy init
293 * - use inode PA
294 * we need to make sure that either on-disk bitmap or PA has uptodate data
295 * given (3) we care that PA-=N operation doesn't interfere with init
296 * - discard inode PA
297 * the simplest way would be to have buddy initialized by the discard
298 * - use locality group PA
299 * again PA-=N must be serialized with init
300 * - discard locality group PA
301 * the simplest way would be to have buddy initialized by the discard
302 * - new PA vs.
303 * - use inode PA
304 * i_data_sem serializes them
305 * - discard inode PA
306 * discard process must wait until PA isn't used by another process
307 * - use locality group PA
308 * some mutex should serialize them
309 * - discard locality group PA
310 * discard process must wait until PA isn't used by another process
311 * - use inode PA
312 * - use inode PA
313 * i_data_sem or another mutex should serializes them
314 * - discard inode PA
315 * discard process must wait until PA isn't used by another process
316 * - use locality group PA
317 * nothing wrong here -- they're different PAs covering different blocks
318 * - discard locality group PA
319 * discard process must wait until PA isn't used by another process
320 *
321 * now we're ready to make few consequences:
322 * - PA is referenced and while it is no discard is possible
323 * - PA is referenced until block isn't marked in on-disk bitmap
324 * - PA changes only after on-disk bitmap
325 * - discard must not compete with init. either init is done before
326 * any discard or they're serialized somehow
327 * - buddy init as sum of on-disk bitmap and PAs is done atomically
328 *
329 * a special case when we've used PA to emptiness. no need to modify buddy
330 * in this case, but we should care about concurrent init
331 *
332 */
333
334 /*
335 * Logic in few words:
336 *
337 * - allocation:
338 * load group
339 * find blocks
340 * mark bits in on-disk bitmap
341 * release group
342 *
343 * - use preallocation:
344 * find proper PA (per-inode or group)
345 * load group
346 * mark bits in on-disk bitmap
347 * release group
348 * release PA
349 *
350 * - free:
351 * load group
352 * mark bits in on-disk bitmap
353 * release group
354 *
355 * - discard preallocations in group:
356 * mark PAs deleted
357 * move them onto local list
358 * load on-disk bitmap
359 * load group
360 * remove PA from object (inode or locality group)
361 * mark free blocks in-core
362 *
363 * - discard inode's preallocations:
364 */
365
366/*
367 * Locking rules
368 *
369 * Locks:
370 * - bitlock on a group (group)
371 * - object (inode/locality) (object)
372 * - per-pa lock (pa)
373 * - cr_power2_aligned lists lock (cr_power2_aligned)
374 * - cr_goal_len_fast lists lock (cr_goal_len_fast)
375 *
376 * Paths:
377 * - new pa
378 * object
379 * group
380 *
381 * - find and use pa:
382 * pa
383 *
384 * - release consumed pa:
385 * pa
386 * group
387 * object
388 *
389 * - generate in-core bitmap:
390 * group
391 * pa
392 *
393 * - discard all for given object (inode, locality group):
394 * object
395 * pa
396 * group
397 *
398 * - discard all for given group:
399 * group
400 * pa
401 * group
402 * object
403 *
404 * - allocation path (ext4_mb_regular_allocator)
405 * group
406 * cr_power2_aligned/cr_goal_len_fast
407 */
408static struct kmem_cache *ext4_pspace_cachep;
409static struct kmem_cache *ext4_ac_cachep;
410static struct kmem_cache *ext4_free_data_cachep;
411
412/* We create slab caches for groupinfo data structures based on the
413 * superblock block size. There will be one per mounted filesystem for
414 * each unique s_blocksize_bits */
415#define NR_GRPINFO_CACHES 8
416static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
417
418static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
419 "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
420 "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
421 "ext4_groupinfo_64k", "ext4_groupinfo_128k"
422};
423
424static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
425 ext4_group_t group);
426static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
427
428static int ext4_mb_scan_group(struct ext4_allocation_context *ac,
429 ext4_group_t group);
430
431static int ext4_try_to_trim_range(struct super_block *sb,
432 struct ext4_buddy *e4b, ext4_grpblk_t start,
433 ext4_grpblk_t max, ext4_grpblk_t minblocks);
434
435/*
436 * The algorithm using this percpu seq counter goes below:
437 * 1. We sample the percpu discard_pa_seq counter before trying for block
438 * allocation in ext4_mb_new_blocks().
439 * 2. We increment this percpu discard_pa_seq counter when we either allocate
440 * or free these blocks i.e. while marking those blocks as used/free in
441 * mb_mark_used()/mb_free_blocks().
442 * 3. We also increment this percpu seq counter when we successfully identify
443 * that the bb_prealloc_list is not empty and hence proceed for discarding
444 * of those PAs inside ext4_mb_discard_group_preallocations().
445 *
446 * Now to make sure that the regular fast path of block allocation is not
447 * affected, as a small optimization we only sample the percpu seq counter
448 * on that cpu. Only when the block allocation fails and when freed blocks
449 * found were 0, that is when we sample percpu seq counter for all cpus using
450 * below function ext4_get_discard_pa_seq_sum(). This happens after making
451 * sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty.
452 */
453static DEFINE_PER_CPU(u64, discard_pa_seq);
454static inline u64 ext4_get_discard_pa_seq_sum(void)
455{
456 int __cpu;
457 u64 __seq = 0;
458
459 for_each_possible_cpu(__cpu)
460 __seq += per_cpu(discard_pa_seq, __cpu);
461 return __seq;
462}
463
464static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
465{
466#if BITS_PER_LONG == 64
467 *bit += ((unsigned long) addr & 7UL) << 3;
468 addr = (void *) ((unsigned long) addr & ~7UL);
469#elif BITS_PER_LONG == 32
470 *bit += ((unsigned long) addr & 3UL) << 3;
471 addr = (void *) ((unsigned long) addr & ~3UL);
472#else
473#error "how many bits you are?!"
474#endif
475 return addr;
476}
477
478static inline int mb_test_bit(int bit, void *addr)
479{
480 /*
481 * ext4_test_bit on architecture like powerpc
482 * needs unsigned long aligned address
483 */
484 addr = mb_correct_addr_and_bit(bit: &bit, addr);
485 return ext4_test_bit(nr: bit, addr);
486}
487
488static inline void mb_set_bit(int bit, void *addr)
489{
490 addr = mb_correct_addr_and_bit(bit: &bit, addr);
491 ext4_set_bit(nr: bit, addr);
492}
493
494static inline void mb_clear_bit(int bit, void *addr)
495{
496 addr = mb_correct_addr_and_bit(bit: &bit, addr);
497 ext4_clear_bit(nr: bit, addr);
498}
499
500static inline int mb_test_and_clear_bit(int bit, void *addr)
501{
502 addr = mb_correct_addr_and_bit(bit: &bit, addr);
503 return ext4_test_and_clear_bit(nr: bit, addr);
504}
505
506static inline int mb_find_next_zero_bit(void *addr, int max, int start)
507{
508 int fix = 0, ret, tmpmax;
509 addr = mb_correct_addr_and_bit(bit: &fix, addr);
510 tmpmax = max + fix;
511 start += fix;
512
513 ret = ext4_find_next_zero_bit(addr, size: tmpmax, offset: start) - fix;
514 if (ret > max)
515 return max;
516 return ret;
517}
518
519static inline int mb_find_next_bit(void *addr, int max, int start)
520{
521 int fix = 0, ret, tmpmax;
522 addr = mb_correct_addr_and_bit(bit: &fix, addr);
523 tmpmax = max + fix;
524 start += fix;
525
526 ret = ext4_find_next_bit(addr, size: tmpmax, offset: start) - fix;
527 if (ret > max)
528 return max;
529 return ret;
530}
531
532static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
533{
534 char *bb;
535
536 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
537 BUG_ON(max == NULL);
538
539 if (order > e4b->bd_blkbits + 1) {
540 *max = 0;
541 return NULL;
542 }
543
544 /* at order 0 we see each particular block */
545 if (order == 0) {
546 *max = 1 << (e4b->bd_blkbits + 3);
547 return e4b->bd_bitmap;
548 }
549
550 bb = e4b->bd_buddy + EXT4_SB(sb: e4b->bd_sb)->s_mb_offsets[order];
551 *max = EXT4_SB(sb: e4b->bd_sb)->s_mb_maxs[order];
552
553 return bb;
554}
555
556#ifdef DOUBLE_CHECK
557static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
558 int first, int count)
559{
560 int i;
561 struct super_block *sb = e4b->bd_sb;
562
563 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
564 return;
565 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
566 for (i = 0; i < count; i++) {
567 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
568 ext4_fsblk_t blocknr;
569
570 blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
571 blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
572 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
573 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
574 ext4_grp_locked_error(sb, e4b->bd_group,
575 inode ? inode->i_ino : 0,
576 blocknr,
577 "freeing block already freed "
578 "(bit %u)",
579 first + i);
580 }
581 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
582 }
583}
584
585static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
586{
587 int i;
588
589 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
590 return;
591 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
592 for (i = 0; i < count; i++) {
593 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
594 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
595 }
596}
597
598static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
599{
600 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
601 return;
602 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
603 unsigned char *b1, *b2;
604 int i;
605 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
606 b2 = (unsigned char *) bitmap;
607 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
608 if (b1[i] != b2[i]) {
609 ext4_msg(e4b->bd_sb, KERN_ERR,
610 "corruption in group %u "
611 "at byte %u(%u): %x in copy != %x "
612 "on disk/prealloc",
613 e4b->bd_group, i, i * 8, b1[i], b2[i]);
614 BUG();
615 }
616 }
617 }
618}
619
620static void mb_group_bb_bitmap_alloc(struct super_block *sb,
621 struct ext4_group_info *grp, ext4_group_t group)
622{
623 struct buffer_head *bh;
624
625 grp->bb_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS);
626 if (!grp->bb_bitmap)
627 return;
628
629 bh = ext4_read_block_bitmap(sb, group);
630 if (IS_ERR_OR_NULL(bh)) {
631 kfree(grp->bb_bitmap);
632 grp->bb_bitmap = NULL;
633 return;
634 }
635
636 memcpy(grp->bb_bitmap, bh->b_data, sb->s_blocksize);
637 put_bh(bh);
638}
639
640static void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
641{
642 kfree(grp->bb_bitmap);
643}
644
645#else
646static inline void mb_free_blocks_double(struct inode *inode,
647 struct ext4_buddy *e4b, int first, int count)
648{
649 return;
650}
651static inline void mb_mark_used_double(struct ext4_buddy *e4b,
652 int first, int count)
653{
654 return;
655}
656static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
657{
658 return;
659}
660
661static inline void mb_group_bb_bitmap_alloc(struct super_block *sb,
662 struct ext4_group_info *grp, ext4_group_t group)
663{
664 return;
665}
666
667static inline void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
668{
669 return;
670}
671#endif
672
673#ifdef AGGRESSIVE_CHECK
674
675#define MB_CHECK_ASSERT(assert) \
676do { \
677 if (!(assert)) { \
678 printk(KERN_EMERG \
679 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
680 function, file, line, # assert); \
681 BUG(); \
682 } \
683} while (0)
684
685static void __mb_check_buddy(struct ext4_buddy *e4b, char *file,
686 const char *function, int line)
687{
688 struct super_block *sb = e4b->bd_sb;
689 int order = e4b->bd_blkbits + 1;
690 int max;
691 int max2;
692 int i;
693 int j;
694 int k;
695 int count;
696 struct ext4_group_info *grp;
697 int fragments = 0;
698 int fstart;
699 struct list_head *cur;
700 void *buddy;
701 void *buddy2;
702
703 if (e4b->bd_info->bb_check_counter++ % 10)
704 return;
705
706 while (order > 1) {
707 buddy = mb_find_buddy(e4b, order, &max);
708 MB_CHECK_ASSERT(buddy);
709 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
710 MB_CHECK_ASSERT(buddy2);
711 MB_CHECK_ASSERT(buddy != buddy2);
712 MB_CHECK_ASSERT(max * 2 == max2);
713
714 count = 0;
715 for (i = 0; i < max; i++) {
716
717 if (mb_test_bit(i, buddy)) {
718 /* only single bit in buddy2 may be 0 */
719 if (!mb_test_bit(i << 1, buddy2)) {
720 MB_CHECK_ASSERT(
721 mb_test_bit((i<<1)+1, buddy2));
722 }
723 continue;
724 }
725
726 /* both bits in buddy2 must be 1 */
727 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
728 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
729
730 for (j = 0; j < (1 << order); j++) {
731 k = (i * (1 << order)) + j;
732 MB_CHECK_ASSERT(
733 !mb_test_bit(k, e4b->bd_bitmap));
734 }
735 count++;
736 }
737 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
738 order--;
739 }
740
741 fstart = -1;
742 buddy = mb_find_buddy(e4b, 0, &max);
743 for (i = 0; i < max; i++) {
744 if (!mb_test_bit(i, buddy)) {
745 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
746 if (fstart == -1) {
747 fragments++;
748 fstart = i;
749 }
750 continue;
751 }
752 fstart = -1;
753 /* check used bits only */
754 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
755 buddy2 = mb_find_buddy(e4b, j, &max2);
756 k = i >> j;
757 MB_CHECK_ASSERT(k < max2);
758 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
759 }
760 }
761 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
762 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
763
764 grp = ext4_get_group_info(sb, e4b->bd_group);
765 if (!grp)
766 return;
767 list_for_each(cur, &grp->bb_prealloc_list) {
768 ext4_group_t groupnr;
769 struct ext4_prealloc_space *pa;
770 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
771 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
772 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
773 for (i = 0; i < pa->pa_len; i++)
774 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
775 }
776}
777#undef MB_CHECK_ASSERT
778#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
779 __FILE__, __func__, __LINE__)
780#else
781#define mb_check_buddy(e4b)
782#endif
783
784/*
785 * Divide blocks started from @first with length @len into
786 * smaller chunks with power of 2 blocks.
787 * Clear the bits in bitmap which the blocks of the chunk(s) covered,
788 * then increase bb_counters[] for corresponded chunk size.
789 */
790static void ext4_mb_mark_free_simple(struct super_block *sb,
791 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
792 struct ext4_group_info *grp)
793{
794 struct ext4_sb_info *sbi = EXT4_SB(sb);
795 ext4_grpblk_t min;
796 ext4_grpblk_t max;
797 ext4_grpblk_t chunk;
798 unsigned int border;
799
800 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
801
802 border = 2 << sb->s_blocksize_bits;
803
804 while (len > 0) {
805 /* find how many blocks can be covered since this position */
806 max = ffs(first | border) - 1;
807
808 /* find how many blocks of power 2 we need to mark */
809 min = fls(x: len) - 1;
810
811 if (max < min)
812 min = max;
813 chunk = 1 << min;
814
815 /* mark multiblock chunks only */
816 grp->bb_counters[min]++;
817 if (min > 0)
818 mb_clear_bit(bit: first >> min,
819 addr: buddy + sbi->s_mb_offsets[min]);
820
821 len -= chunk;
822 first += chunk;
823 }
824}
825
826static int mb_avg_fragment_size_order(struct super_block *sb, ext4_grpblk_t len)
827{
828 int order;
829
830 /*
831 * We don't bother with a special lists groups with only 1 block free
832 * extents and for completely empty groups.
833 */
834 order = fls(x: len) - 2;
835 if (order < 0)
836 return 0;
837 if (order == MB_NUM_ORDERS(sb))
838 order--;
839 if (WARN_ON_ONCE(order > MB_NUM_ORDERS(sb)))
840 order = MB_NUM_ORDERS(sb) - 1;
841 return order;
842}
843
844/* Move group to appropriate avg_fragment_size list */
845static void
846mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
847{
848 struct ext4_sb_info *sbi = EXT4_SB(sb);
849 int new, old;
850
851 if (!test_opt2(sb, MB_OPTIMIZE_SCAN))
852 return;
853
854 old = grp->bb_avg_fragment_size_order;
855 new = grp->bb_fragments == 0 ? -1 :
856 mb_avg_fragment_size_order(sb, len: grp->bb_free / grp->bb_fragments);
857 if (new == old)
858 return;
859
860 if (old >= 0)
861 xa_erase(&sbi->s_mb_avg_fragment_size[old], index: grp->bb_group);
862
863 grp->bb_avg_fragment_size_order = new;
864 if (new >= 0) {
865 /*
866 * Cannot use __GFP_NOFAIL because we hold the group lock.
867 * Although allocation for insertion may fails, it's not fatal
868 * as we have linear traversal to fall back on.
869 */
870 int err = xa_insert(xa: &sbi->s_mb_avg_fragment_size[new],
871 index: grp->bb_group, entry: grp, GFP_ATOMIC);
872 if (err)
873 mb_debug(sb, "insert group: %u to s_mb_avg_fragment_size[%d] failed, err %d",
874 grp->bb_group, new, err);
875 }
876}
877
878static int ext4_mb_scan_groups_xa_range(struct ext4_allocation_context *ac,
879 struct xarray *xa,
880 ext4_group_t start, ext4_group_t end)
881{
882 struct super_block *sb = ac->ac_sb;
883 struct ext4_sb_info *sbi = EXT4_SB(sb);
884 enum criteria cr = ac->ac_criteria;
885 ext4_group_t ngroups = ext4_get_groups_count(sb);
886 unsigned long group = start;
887 struct ext4_group_info *grp;
888
889 if (WARN_ON_ONCE(end > ngroups || start >= end))
890 return 0;
891
892 xa_for_each_range(xa, group, grp, start, end - 1) {
893 int err;
894
895 if (sbi->s_mb_stats)
896 atomic64_inc(v: &sbi->s_bal_cX_groups_considered[cr]);
897
898 err = ext4_mb_scan_group(ac, group: grp->bb_group);
899 if (err || ac->ac_status != AC_STATUS_CONTINUE)
900 return err;
901
902 cond_resched();
903 }
904
905 return 0;
906}
907
908/*
909 * Find a suitable group of given order from the largest free orders xarray.
910 */
911static inline int
912ext4_mb_scan_groups_largest_free_order_range(struct ext4_allocation_context *ac,
913 int order, ext4_group_t start,
914 ext4_group_t end)
915{
916 struct xarray *xa = &EXT4_SB(sb: ac->ac_sb)->s_mb_largest_free_orders[order];
917
918 if (xa_empty(xa))
919 return 0;
920
921 return ext4_mb_scan_groups_xa_range(ac, xa, start, end);
922}
923
924/*
925 * Choose next group by traversing largest_free_order lists. Updates *new_cr if
926 * cr level needs an update.
927 */
928static int ext4_mb_scan_groups_p2_aligned(struct ext4_allocation_context *ac,
929 ext4_group_t group)
930{
931 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
932 int i;
933 int ret = 0;
934 ext4_group_t start, end;
935
936 start = group;
937 end = ext4_get_groups_count(sb: ac->ac_sb);
938wrap_around:
939 for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) {
940 ret = ext4_mb_scan_groups_largest_free_order_range(ac, order: i,
941 start, end);
942 if (ret || ac->ac_status != AC_STATUS_CONTINUE)
943 return ret;
944 }
945 if (start) {
946 end = start;
947 start = 0;
948 goto wrap_around;
949 }
950
951 if (sbi->s_mb_stats)
952 atomic64_inc(v: &sbi->s_bal_cX_failed[ac->ac_criteria]);
953
954 /* Increment cr and search again if no group is found */
955 ac->ac_criteria = CR_GOAL_LEN_FAST;
956 return ret;
957}
958
959/*
960 * Find a suitable group of given order from the average fragments xarray.
961 */
962static int
963ext4_mb_scan_groups_avg_frag_order_range(struct ext4_allocation_context *ac,
964 int order, ext4_group_t start,
965 ext4_group_t end)
966{
967 struct xarray *xa = &EXT4_SB(sb: ac->ac_sb)->s_mb_avg_fragment_size[order];
968
969 if (xa_empty(xa))
970 return 0;
971
972 return ext4_mb_scan_groups_xa_range(ac, xa, start, end);
973}
974
975/*
976 * Choose next group by traversing average fragment size list of suitable
977 * order. Updates *new_cr if cr level needs an update.
978 */
979static int ext4_mb_scan_groups_goal_fast(struct ext4_allocation_context *ac,
980 ext4_group_t group)
981{
982 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
983 int i, ret = 0;
984 ext4_group_t start, end;
985
986 start = group;
987 end = ext4_get_groups_count(sb: ac->ac_sb);
988wrap_around:
989 i = mb_avg_fragment_size_order(sb: ac->ac_sb, len: ac->ac_g_ex.fe_len);
990 for (; i < MB_NUM_ORDERS(ac->ac_sb); i++) {
991 ret = ext4_mb_scan_groups_avg_frag_order_range(ac, order: i,
992 start, end);
993 if (ret || ac->ac_status != AC_STATUS_CONTINUE)
994 return ret;
995 }
996 if (start) {
997 end = start;
998 start = 0;
999 goto wrap_around;
1000 }
1001
1002 if (sbi->s_mb_stats)
1003 atomic64_inc(v: &sbi->s_bal_cX_failed[ac->ac_criteria]);
1004 /*
1005 * CR_BEST_AVAIL_LEN works based on the concept that we have
1006 * a larger normalized goal len request which can be trimmed to
1007 * a smaller goal len such that it can still satisfy original
1008 * request len. However, allocation request for non-regular
1009 * files never gets normalized.
1010 * See function ext4_mb_normalize_request() (EXT4_MB_HINT_DATA).
1011 */
1012 if (ac->ac_flags & EXT4_MB_HINT_DATA)
1013 ac->ac_criteria = CR_BEST_AVAIL_LEN;
1014 else
1015 ac->ac_criteria = CR_GOAL_LEN_SLOW;
1016
1017 return ret;
1018}
1019
1020/*
1021 * We couldn't find a group in CR_GOAL_LEN_FAST so try to find the highest free fragment
1022 * order we have and proactively trim the goal request length to that order to
1023 * find a suitable group faster.
1024 *
1025 * This optimizes allocation speed at the cost of slightly reduced
1026 * preallocations. However, we make sure that we don't trim the request too
1027 * much and fall to CR_GOAL_LEN_SLOW in that case.
1028 */
1029static int ext4_mb_scan_groups_best_avail(struct ext4_allocation_context *ac,
1030 ext4_group_t group)
1031{
1032 int ret = 0;
1033 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
1034 int i, order, min_order;
1035 unsigned long num_stripe_clusters = 0;
1036 ext4_group_t start, end;
1037
1038 /*
1039 * mb_avg_fragment_size_order() returns order in a way that makes
1040 * retrieving back the length using (1 << order) inaccurate. Hence, use
1041 * fls() instead since we need to know the actual length while modifying
1042 * goal length.
1043 */
1044 order = fls(x: ac->ac_g_ex.fe_len) - 1;
1045 if (WARN_ON_ONCE(order - 1 > MB_NUM_ORDERS(ac->ac_sb)))
1046 order = MB_NUM_ORDERS(ac->ac_sb);
1047 min_order = order - sbi->s_mb_best_avail_max_trim_order;
1048 if (min_order < 0)
1049 min_order = 0;
1050
1051 if (sbi->s_stripe > 0) {
1052 /*
1053 * We are assuming that stripe size is always a multiple of
1054 * cluster ratio otherwise __ext4_fill_super exists early.
1055 */
1056 num_stripe_clusters = EXT4_NUM_B2C(sbi, sbi->s_stripe);
1057 if (1 << min_order < num_stripe_clusters)
1058 /*
1059 * We consider 1 order less because later we round
1060 * up the goal len to num_stripe_clusters
1061 */
1062 min_order = fls(x: num_stripe_clusters) - 1;
1063 }
1064
1065 if (1 << min_order < ac->ac_o_ex.fe_len)
1066 min_order = fls(x: ac->ac_o_ex.fe_len);
1067
1068 start = group;
1069 end = ext4_get_groups_count(sb: ac->ac_sb);
1070wrap_around:
1071 for (i = order; i >= min_order; i--) {
1072 int frag_order;
1073 /*
1074 * Scale down goal len to make sure we find something
1075 * in the free fragments list. Basically, reduce
1076 * preallocations.
1077 */
1078 ac->ac_g_ex.fe_len = 1 << i;
1079
1080 if (num_stripe_clusters > 0) {
1081 /*
1082 * Try to round up the adjusted goal length to
1083 * stripe size (in cluster units) multiple for
1084 * efficiency.
1085 */
1086 ac->ac_g_ex.fe_len = roundup(ac->ac_g_ex.fe_len,
1087 num_stripe_clusters);
1088 }
1089
1090 frag_order = mb_avg_fragment_size_order(sb: ac->ac_sb,
1091 len: ac->ac_g_ex.fe_len);
1092
1093 ret = ext4_mb_scan_groups_avg_frag_order_range(ac, order: frag_order,
1094 start, end);
1095 if (ret || ac->ac_status != AC_STATUS_CONTINUE)
1096 return ret;
1097 }
1098 if (start) {
1099 end = start;
1100 start = 0;
1101 goto wrap_around;
1102 }
1103
1104 /* Reset goal length to original goal length before falling into CR_GOAL_LEN_SLOW */
1105 ac->ac_g_ex.fe_len = ac->ac_orig_goal_len;
1106 if (sbi->s_mb_stats)
1107 atomic64_inc(v: &sbi->s_bal_cX_failed[ac->ac_criteria]);
1108 ac->ac_criteria = CR_GOAL_LEN_SLOW;
1109
1110 return ret;
1111}
1112
1113static inline int should_optimize_scan(struct ext4_allocation_context *ac)
1114{
1115 if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN)))
1116 return 0;
1117 if (ac->ac_criteria >= CR_GOAL_LEN_SLOW)
1118 return 0;
1119 if (!ext4_test_inode_flag(inode: ac->ac_inode, bit: EXT4_INODE_EXTENTS))
1120 return 0;
1121 return 1;
1122}
1123
1124/*
1125 * next linear group for allocation.
1126 */
1127static void next_linear_group(ext4_group_t *group, ext4_group_t ngroups)
1128{
1129 /*
1130 * Artificially restricted ngroups for non-extent
1131 * files makes group > ngroups possible on first loop.
1132 */
1133 *group = *group + 1 >= ngroups ? 0 : *group + 1;
1134}
1135
1136static int ext4_mb_scan_groups_linear(struct ext4_allocation_context *ac,
1137 ext4_group_t ngroups, ext4_group_t *start, ext4_group_t count)
1138{
1139 int ret, i;
1140 enum criteria cr = ac->ac_criteria;
1141 struct super_block *sb = ac->ac_sb;
1142 struct ext4_sb_info *sbi = EXT4_SB(sb);
1143 ext4_group_t group = *start;
1144
1145 for (i = 0; i < count; i++, next_linear_group(group: &group, ngroups)) {
1146 ret = ext4_mb_scan_group(ac, group);
1147 if (ret || ac->ac_status != AC_STATUS_CONTINUE)
1148 return ret;
1149 cond_resched();
1150 }
1151
1152 *start = group;
1153 if (count == ngroups)
1154 ac->ac_criteria++;
1155
1156 /* Processed all groups and haven't found blocks */
1157 if (sbi->s_mb_stats && i == ngroups)
1158 atomic64_inc(v: &sbi->s_bal_cX_failed[cr]);
1159
1160 return 0;
1161}
1162
1163static int ext4_mb_scan_groups(struct ext4_allocation_context *ac)
1164{
1165 int ret = 0;
1166 ext4_group_t start;
1167 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
1168 ext4_group_t ngroups = ext4_get_groups_count(sb: ac->ac_sb);
1169
1170 /* non-extent files are limited to low blocks/groups */
1171 if (!(ext4_test_inode_flag(inode: ac->ac_inode, bit: EXT4_INODE_EXTENTS)))
1172 ngroups = sbi->s_blockfile_groups;
1173
1174 /* searching for the right group start from the goal value specified */
1175 start = ac->ac_g_ex.fe_group;
1176 ac->ac_prefetch_grp = start;
1177 ac->ac_prefetch_nr = 0;
1178
1179 if (!should_optimize_scan(ac))
1180 return ext4_mb_scan_groups_linear(ac, ngroups, start: &start, count: ngroups);
1181
1182 /*
1183 * Optimized scanning can return non adjacent groups which can cause
1184 * seek overhead for rotational disks. So try few linear groups before
1185 * trying optimized scan.
1186 */
1187 if (sbi->s_mb_max_linear_groups)
1188 ret = ext4_mb_scan_groups_linear(ac, ngroups, start: &start,
1189 count: sbi->s_mb_max_linear_groups);
1190 if (ret || ac->ac_status != AC_STATUS_CONTINUE)
1191 return ret;
1192
1193 switch (ac->ac_criteria) {
1194 case CR_POWER2_ALIGNED:
1195 return ext4_mb_scan_groups_p2_aligned(ac, group: start);
1196 case CR_GOAL_LEN_FAST:
1197 return ext4_mb_scan_groups_goal_fast(ac, group: start);
1198 case CR_BEST_AVAIL_LEN:
1199 return ext4_mb_scan_groups_best_avail(ac, group: start);
1200 default:
1201 /*
1202 * TODO: For CR_GOAL_LEN_SLOW, we can arrange groups in an
1203 * rb tree sorted by bb_free. But until that happens, we should
1204 * never come here.
1205 */
1206 WARN_ON(1);
1207 }
1208
1209 return 0;
1210}
1211
1212/*
1213 * Cache the order of the largest free extent we have available in this block
1214 * group.
1215 */
1216static void
1217mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
1218{
1219 struct ext4_sb_info *sbi = EXT4_SB(sb);
1220 int new, old = grp->bb_largest_free_order;
1221
1222 for (new = MB_NUM_ORDERS(sb) - 1; new >= 0; new--)
1223 if (grp->bb_counters[new] > 0)
1224 break;
1225
1226 /* No need to move between order lists? */
1227 if (new == old)
1228 return;
1229
1230 if (old >= 0) {
1231 struct xarray *xa = &sbi->s_mb_largest_free_orders[old];
1232
1233 if (!xa_empty(xa) && xa_load(xa, index: grp->bb_group))
1234 xa_erase(xa, index: grp->bb_group);
1235 }
1236
1237 grp->bb_largest_free_order = new;
1238 if (test_opt2(sb, MB_OPTIMIZE_SCAN) && new >= 0 && grp->bb_free) {
1239 /*
1240 * Cannot use __GFP_NOFAIL because we hold the group lock.
1241 * Although allocation for insertion may fails, it's not fatal
1242 * as we have linear traversal to fall back on.
1243 */
1244 int err = xa_insert(xa: &sbi->s_mb_largest_free_orders[new],
1245 index: grp->bb_group, entry: grp, GFP_ATOMIC);
1246 if (err)
1247 mb_debug(sb, "insert group: %u to s_mb_largest_free_orders[%d] failed, err %d",
1248 grp->bb_group, new, err);
1249 }
1250}
1251
1252static noinline_for_stack
1253void ext4_mb_generate_buddy(struct super_block *sb,
1254 void *buddy, void *bitmap, ext4_group_t group,
1255 struct ext4_group_info *grp)
1256{
1257 struct ext4_sb_info *sbi = EXT4_SB(sb);
1258 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
1259 ext4_grpblk_t i = 0;
1260 ext4_grpblk_t first;
1261 ext4_grpblk_t len;
1262 unsigned free = 0;
1263 unsigned fragments = 0;
1264 unsigned long long period = get_cycles();
1265
1266 /* initialize buddy from bitmap which is aggregation
1267 * of on-disk bitmap and preallocations */
1268 i = mb_find_next_zero_bit(addr: bitmap, max, start: 0);
1269 grp->bb_first_free = i;
1270 while (i < max) {
1271 fragments++;
1272 first = i;
1273 i = mb_find_next_bit(addr: bitmap, max, start: i);
1274 len = i - first;
1275 free += len;
1276 if (len > 1)
1277 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
1278 else
1279 grp->bb_counters[0]++;
1280 if (i < max)
1281 i = mb_find_next_zero_bit(addr: bitmap, max, start: i);
1282 }
1283 grp->bb_fragments = fragments;
1284
1285 if (free != grp->bb_free) {
1286 ext4_grp_locked_error(sb, group, 0, 0,
1287 "block bitmap and bg descriptor "
1288 "inconsistent: %u vs %u free clusters",
1289 free, grp->bb_free);
1290 /*
1291 * If we intend to continue, we consider group descriptor
1292 * corrupt and update bb_free using bitmap value
1293 */
1294 grp->bb_free = free;
1295 ext4_mark_group_bitmap_corrupted(sb, block_group: group,
1296 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1297 }
1298 mb_set_largest_free_order(sb, grp);
1299 mb_update_avg_fragment_size(sb, grp);
1300
1301 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, addr: &(grp->bb_state));
1302
1303 period = get_cycles() - period;
1304 atomic_inc(v: &sbi->s_mb_buddies_generated);
1305 atomic64_add(i: period, v: &sbi->s_mb_generation_time);
1306}
1307
1308static void mb_regenerate_buddy(struct ext4_buddy *e4b)
1309{
1310 int count;
1311 int order = 1;
1312 void *buddy;
1313
1314 while ((buddy = mb_find_buddy(e4b, order: order++, max: &count)))
1315 mb_set_bits(bm: buddy, cur: 0, len: count);
1316
1317 e4b->bd_info->bb_fragments = 0;
1318 memset(s: e4b->bd_info->bb_counters, c: 0,
1319 n: sizeof(*e4b->bd_info->bb_counters) *
1320 (e4b->bd_sb->s_blocksize_bits + 2));
1321
1322 ext4_mb_generate_buddy(sb: e4b->bd_sb, buddy: e4b->bd_buddy,
1323 bitmap: e4b->bd_bitmap, group: e4b->bd_group, grp: e4b->bd_info);
1324}
1325
1326/* The buddy information is attached the buddy cache inode
1327 * for convenience. The information regarding each group
1328 * is loaded via ext4_mb_load_buddy. The information involve
1329 * block bitmap and buddy information. The information are
1330 * stored in the inode as
1331 *
1332 * { page }
1333 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
1334 *
1335 *
1336 * one block each for bitmap and buddy information.
1337 * So for each group we take up 2 blocks. A page can
1338 * contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
1339 * So it can have information regarding groups_per_page which
1340 * is blocks_per_page/2
1341 *
1342 * Locking note: This routine takes the block group lock of all groups
1343 * for this page; do not hold this lock when calling this routine!
1344 */
1345
1346static int ext4_mb_init_cache(struct folio *folio, char *incore, gfp_t gfp)
1347{
1348 ext4_group_t ngroups;
1349 unsigned int blocksize;
1350 int blocks_per_page;
1351 int groups_per_page;
1352 int err = 0;
1353 int i;
1354 ext4_group_t first_group, group;
1355 int first_block;
1356 struct super_block *sb;
1357 struct buffer_head *bhs;
1358 struct buffer_head **bh = NULL;
1359 struct inode *inode;
1360 char *data;
1361 char *bitmap;
1362 struct ext4_group_info *grinfo;
1363
1364 inode = folio->mapping->host;
1365 sb = inode->i_sb;
1366 ngroups = ext4_get_groups_count(sb);
1367 blocksize = i_blocksize(node: inode);
1368 blocks_per_page = PAGE_SIZE / blocksize;
1369
1370 mb_debug(sb, "init folio %lu\n", folio->index);
1371
1372 groups_per_page = blocks_per_page >> 1;
1373 if (groups_per_page == 0)
1374 groups_per_page = 1;
1375
1376 /* allocate buffer_heads to read bitmaps */
1377 if (groups_per_page > 1) {
1378 i = sizeof(struct buffer_head *) * groups_per_page;
1379 bh = kzalloc(i, gfp);
1380 if (bh == NULL)
1381 return -ENOMEM;
1382 } else
1383 bh = &bhs;
1384
1385 first_group = folio->index * blocks_per_page / 2;
1386
1387 /* read all groups the folio covers into the cache */
1388 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1389 if (group >= ngroups)
1390 break;
1391
1392 grinfo = ext4_get_group_info(sb, group);
1393 if (!grinfo)
1394 continue;
1395 /*
1396 * If page is uptodate then we came here after online resize
1397 * which added some new uninitialized group info structs, so
1398 * we must skip all initialized uptodate buddies on the folio,
1399 * which may be currently in use by an allocating task.
1400 */
1401 if (folio_test_uptodate(folio) &&
1402 !EXT4_MB_GRP_NEED_INIT(grinfo)) {
1403 bh[i] = NULL;
1404 continue;
1405 }
1406 bh[i] = ext4_read_block_bitmap_nowait(sb, block_group: group, ignore_locked: false);
1407 if (IS_ERR(ptr: bh[i])) {
1408 err = PTR_ERR(ptr: bh[i]);
1409 bh[i] = NULL;
1410 goto out;
1411 }
1412 mb_debug(sb, "read bitmap for group %u\n", group);
1413 }
1414
1415 /* wait for I/O completion */
1416 for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1417 int err2;
1418
1419 if (!bh[i])
1420 continue;
1421 err2 = ext4_wait_block_bitmap(sb, block_group: group, bh: bh[i]);
1422 if (!err)
1423 err = err2;
1424 }
1425
1426 first_block = folio->index * blocks_per_page;
1427 for (i = 0; i < blocks_per_page; i++) {
1428 group = (first_block + i) >> 1;
1429 if (group >= ngroups)
1430 break;
1431
1432 if (!bh[group - first_group])
1433 /* skip initialized uptodate buddy */
1434 continue;
1435
1436 if (!buffer_verified(bh: bh[group - first_group]))
1437 /* Skip faulty bitmaps */
1438 continue;
1439 err = 0;
1440
1441 /*
1442 * data carry information regarding this
1443 * particular group in the format specified
1444 * above
1445 *
1446 */
1447 data = folio_address(folio) + (i * blocksize);
1448 bitmap = bh[group - first_group]->b_data;
1449
1450 /*
1451 * We place the buddy block and bitmap block
1452 * close together
1453 */
1454 grinfo = ext4_get_group_info(sb, group);
1455 if (!grinfo) {
1456 err = -EFSCORRUPTED;
1457 goto out;
1458 }
1459 if ((first_block + i) & 1) {
1460 /* this is block of buddy */
1461 BUG_ON(incore == NULL);
1462 mb_debug(sb, "put buddy for group %u in folio %lu/%x\n",
1463 group, folio->index, i * blocksize);
1464 trace_ext4_mb_buddy_bitmap_load(sb, group);
1465 grinfo->bb_fragments = 0;
1466 memset(s: grinfo->bb_counters, c: 0,
1467 n: sizeof(*grinfo->bb_counters) *
1468 (MB_NUM_ORDERS(sb)));
1469 /*
1470 * incore got set to the group block bitmap below
1471 */
1472 ext4_lock_group(sb, group);
1473 /* init the buddy */
1474 memset(s: data, c: 0xff, n: blocksize);
1475 ext4_mb_generate_buddy(sb, buddy: data, bitmap: incore, group, grp: grinfo);
1476 ext4_unlock_group(sb, group);
1477 incore = NULL;
1478 } else {
1479 /* this is block of bitmap */
1480 BUG_ON(incore != NULL);
1481 mb_debug(sb, "put bitmap for group %u in folio %lu/%x\n",
1482 group, folio->index, i * blocksize);
1483 trace_ext4_mb_bitmap_load(sb, group);
1484
1485 /* see comments in ext4_mb_put_pa() */
1486 ext4_lock_group(sb, group);
1487 memcpy(to: data, from: bitmap, len: blocksize);
1488
1489 /* mark all preallocated blks used in in-core bitmap */
1490 ext4_mb_generate_from_pa(sb, bitmap: data, group);
1491 WARN_ON_ONCE(!RB_EMPTY_ROOT(&grinfo->bb_free_root));
1492 ext4_unlock_group(sb, group);
1493
1494 /* set incore so that the buddy information can be
1495 * generated using this
1496 */
1497 incore = data;
1498 }
1499 }
1500 folio_mark_uptodate(folio);
1501
1502out:
1503 if (bh) {
1504 for (i = 0; i < groups_per_page; i++)
1505 brelse(bh: bh[i]);
1506 if (bh != &bhs)
1507 kfree(objp: bh);
1508 }
1509 return err;
1510}
1511
1512/*
1513 * Lock the buddy and bitmap pages. This make sure other parallel init_group
1514 * on the same buddy page doesn't happen whild holding the buddy page lock.
1515 * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
1516 * are on the same page e4b->bd_buddy_folio is NULL and return value is 0.
1517 */
1518static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
1519 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
1520{
1521 struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
1522 int block, pnum, poff;
1523 int blocks_per_page;
1524 struct folio *folio;
1525
1526 e4b->bd_buddy_folio = NULL;
1527 e4b->bd_bitmap_folio = NULL;
1528
1529 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1530 /*
1531 * the buddy cache inode stores the block bitmap
1532 * and buddy information in consecutive blocks.
1533 * So for each group we need two blocks.
1534 */
1535 block = group * 2;
1536 pnum = block / blocks_per_page;
1537 poff = block % blocks_per_page;
1538 folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum,
1539 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1540 if (IS_ERR(ptr: folio))
1541 return PTR_ERR(ptr: folio);
1542 BUG_ON(folio->mapping != inode->i_mapping);
1543 e4b->bd_bitmap_folio = folio;
1544 e4b->bd_bitmap = folio_address(folio) + (poff * sb->s_blocksize);
1545
1546 if (blocks_per_page >= 2) {
1547 /* buddy and bitmap are on the same page */
1548 return 0;
1549 }
1550
1551 /* blocks_per_page == 1, hence we need another page for the buddy */
1552 folio = __filemap_get_folio(mapping: inode->i_mapping, index: block + 1,
1553 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1554 if (IS_ERR(ptr: folio))
1555 return PTR_ERR(ptr: folio);
1556 BUG_ON(folio->mapping != inode->i_mapping);
1557 e4b->bd_buddy_folio = folio;
1558 return 0;
1559}
1560
1561static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1562{
1563 if (e4b->bd_bitmap_folio) {
1564 folio_unlock(folio: e4b->bd_bitmap_folio);
1565 folio_put(folio: e4b->bd_bitmap_folio);
1566 }
1567 if (e4b->bd_buddy_folio) {
1568 folio_unlock(folio: e4b->bd_buddy_folio);
1569 folio_put(folio: e4b->bd_buddy_folio);
1570 }
1571}
1572
1573/*
1574 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1575 * block group lock of all groups for this page; do not hold the BG lock when
1576 * calling this routine!
1577 */
1578static noinline_for_stack
1579int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1580{
1581
1582 struct ext4_group_info *this_grp;
1583 struct ext4_buddy e4b;
1584 struct folio *folio;
1585 int ret = 0;
1586
1587 might_sleep();
1588 mb_debug(sb, "init group %u\n", group);
1589 this_grp = ext4_get_group_info(sb, group);
1590 if (!this_grp)
1591 return -EFSCORRUPTED;
1592
1593 /*
1594 * This ensures that we don't reinit the buddy cache
1595 * page which map to the group from which we are already
1596 * allocating. If we are looking at the buddy cache we would
1597 * have taken a reference using ext4_mb_load_buddy and that
1598 * would have pinned buddy page to page cache.
1599 * The call to ext4_mb_get_buddy_page_lock will mark the
1600 * page accessed.
1601 */
1602 ret = ext4_mb_get_buddy_page_lock(sb, group, e4b: &e4b, gfp);
1603 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1604 /*
1605 * somebody initialized the group
1606 * return without doing anything
1607 */
1608 goto err;
1609 }
1610
1611 folio = e4b.bd_bitmap_folio;
1612 ret = ext4_mb_init_cache(folio, NULL, gfp);
1613 if (ret)
1614 goto err;
1615 if (!folio_test_uptodate(folio)) {
1616 ret = -EIO;
1617 goto err;
1618 }
1619
1620 if (e4b.bd_buddy_folio == NULL) {
1621 /*
1622 * If both the bitmap and buddy are in
1623 * the same page we don't need to force
1624 * init the buddy
1625 */
1626 ret = 0;
1627 goto err;
1628 }
1629 /* init buddy cache */
1630 folio = e4b.bd_buddy_folio;
1631 ret = ext4_mb_init_cache(folio, incore: e4b.bd_bitmap, gfp);
1632 if (ret)
1633 goto err;
1634 if (!folio_test_uptodate(folio)) {
1635 ret = -EIO;
1636 goto err;
1637 }
1638err:
1639 ext4_mb_put_buddy_page_lock(e4b: &e4b);
1640 return ret;
1641}
1642
1643/*
1644 * Locking note: This routine calls ext4_mb_init_cache(), which takes the
1645 * block group lock of all groups for this page; do not hold the BG lock when
1646 * calling this routine!
1647 */
1648static noinline_for_stack int
1649ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1650 struct ext4_buddy *e4b, gfp_t gfp)
1651{
1652 int blocks_per_page;
1653 int block;
1654 int pnum;
1655 int poff;
1656 struct folio *folio;
1657 int ret;
1658 struct ext4_group_info *grp;
1659 struct ext4_sb_info *sbi = EXT4_SB(sb);
1660 struct inode *inode = sbi->s_buddy_cache;
1661
1662 might_sleep();
1663 mb_debug(sb, "load group %u\n", group);
1664
1665 blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1666 grp = ext4_get_group_info(sb, group);
1667 if (!grp)
1668 return -EFSCORRUPTED;
1669
1670 e4b->bd_blkbits = sb->s_blocksize_bits;
1671 e4b->bd_info = grp;
1672 e4b->bd_sb = sb;
1673 e4b->bd_group = group;
1674 e4b->bd_buddy_folio = NULL;
1675 e4b->bd_bitmap_folio = NULL;
1676
1677 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1678 /*
1679 * we need full data about the group
1680 * to make a good selection
1681 */
1682 ret = ext4_mb_init_group(sb, group, gfp);
1683 if (ret)
1684 return ret;
1685 }
1686
1687 /*
1688 * the buddy cache inode stores the block bitmap
1689 * and buddy information in consecutive blocks.
1690 * So for each group we need two blocks.
1691 */
1692 block = group * 2;
1693 pnum = block / blocks_per_page;
1694 poff = block % blocks_per_page;
1695
1696 /* Avoid locking the folio in the fast path ... */
1697 folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum, FGP_ACCESSED, gfp: 0);
1698 if (IS_ERR(ptr: folio) || !folio_test_uptodate(folio)) {
1699 if (!IS_ERR(ptr: folio))
1700 /*
1701 * drop the folio reference and try
1702 * to get the folio with lock. If we
1703 * are not uptodate that implies
1704 * somebody just created the folio but
1705 * is yet to initialize it. So
1706 * wait for it to initialize.
1707 */
1708 folio_put(folio);
1709 folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum,
1710 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1711 if (!IS_ERR(ptr: folio)) {
1712 if (WARN_RATELIMIT(folio->mapping != inode->i_mapping,
1713 "ext4: bitmap's mapping != inode->i_mapping\n")) {
1714 /* should never happen */
1715 folio_unlock(folio);
1716 ret = -EINVAL;
1717 goto err;
1718 }
1719 if (!folio_test_uptodate(folio)) {
1720 ret = ext4_mb_init_cache(folio, NULL, gfp);
1721 if (ret) {
1722 folio_unlock(folio);
1723 goto err;
1724 }
1725 mb_cmp_bitmaps(e4b, bitmap: folio_address(folio) +
1726 (poff * sb->s_blocksize));
1727 }
1728 folio_unlock(folio);
1729 }
1730 }
1731 if (IS_ERR(ptr: folio)) {
1732 ret = PTR_ERR(ptr: folio);
1733 goto err;
1734 }
1735 if (!folio_test_uptodate(folio)) {
1736 ret = -EIO;
1737 goto err;
1738 }
1739
1740 /* Folios marked accessed already */
1741 e4b->bd_bitmap_folio = folio;
1742 e4b->bd_bitmap = folio_address(folio) + (poff * sb->s_blocksize);
1743
1744 block++;
1745 pnum = block / blocks_per_page;
1746 poff = block % blocks_per_page;
1747
1748 folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum, FGP_ACCESSED, gfp: 0);
1749 if (IS_ERR(ptr: folio) || !folio_test_uptodate(folio)) {
1750 if (!IS_ERR(ptr: folio))
1751 folio_put(folio);
1752 folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum,
1753 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1754 if (!IS_ERR(ptr: folio)) {
1755 if (WARN_RATELIMIT(folio->mapping != inode->i_mapping,
1756 "ext4: buddy bitmap's mapping != inode->i_mapping\n")) {
1757 /* should never happen */
1758 folio_unlock(folio);
1759 ret = -EINVAL;
1760 goto err;
1761 }
1762 if (!folio_test_uptodate(folio)) {
1763 ret = ext4_mb_init_cache(folio, incore: e4b->bd_bitmap,
1764 gfp);
1765 if (ret) {
1766 folio_unlock(folio);
1767 goto err;
1768 }
1769 }
1770 folio_unlock(folio);
1771 }
1772 }
1773 if (IS_ERR(ptr: folio)) {
1774 ret = PTR_ERR(ptr: folio);
1775 goto err;
1776 }
1777 if (!folio_test_uptodate(folio)) {
1778 ret = -EIO;
1779 goto err;
1780 }
1781
1782 /* Folios marked accessed already */
1783 e4b->bd_buddy_folio = folio;
1784 e4b->bd_buddy = folio_address(folio) + (poff * sb->s_blocksize);
1785
1786 return 0;
1787
1788err:
1789 if (!IS_ERR_OR_NULL(ptr: folio))
1790 folio_put(folio);
1791 if (e4b->bd_bitmap_folio)
1792 folio_put(folio: e4b->bd_bitmap_folio);
1793
1794 e4b->bd_buddy = NULL;
1795 e4b->bd_bitmap = NULL;
1796 return ret;
1797}
1798
1799static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1800 struct ext4_buddy *e4b)
1801{
1802 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1803}
1804
1805static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1806{
1807 if (e4b->bd_bitmap_folio)
1808 folio_put(folio: e4b->bd_bitmap_folio);
1809 if (e4b->bd_buddy_folio)
1810 folio_put(folio: e4b->bd_buddy_folio);
1811}
1812
1813
1814static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1815{
1816 int order = 1, max;
1817 void *bb;
1818
1819 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1820 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1821
1822 while (order <= e4b->bd_blkbits + 1) {
1823 bb = mb_find_buddy(e4b, order, max: &max);
1824 if (!mb_test_bit(bit: block >> order, addr: bb)) {
1825 /* this block is part of buddy of order 'order' */
1826 return order;
1827 }
1828 order++;
1829 }
1830 return 0;
1831}
1832
1833static void mb_clear_bits(void *bm, int cur, int len)
1834{
1835 __u32 *addr;
1836
1837 len = cur + len;
1838 while (cur < len) {
1839 if ((cur & 31) == 0 && (len - cur) >= 32) {
1840 /* fast path: clear whole word at once */
1841 addr = bm + (cur >> 3);
1842 *addr = 0;
1843 cur += 32;
1844 continue;
1845 }
1846 mb_clear_bit(bit: cur, addr: bm);
1847 cur++;
1848 }
1849}
1850
1851/* clear bits in given range
1852 * will return first found zero bit if any, -1 otherwise
1853 */
1854static int mb_test_and_clear_bits(void *bm, int cur, int len)
1855{
1856 __u32 *addr;
1857 int zero_bit = -1;
1858
1859 len = cur + len;
1860 while (cur < len) {
1861 if ((cur & 31) == 0 && (len - cur) >= 32) {
1862 /* fast path: clear whole word at once */
1863 addr = bm + (cur >> 3);
1864 if (*addr != (__u32)(-1) && zero_bit == -1)
1865 zero_bit = cur + mb_find_next_zero_bit(addr, max: 32, start: 0);
1866 *addr = 0;
1867 cur += 32;
1868 continue;
1869 }
1870 if (!mb_test_and_clear_bit(bit: cur, addr: bm) && zero_bit == -1)
1871 zero_bit = cur;
1872 cur++;
1873 }
1874
1875 return zero_bit;
1876}
1877
1878void mb_set_bits(void *bm, int cur, int len)
1879{
1880 __u32 *addr;
1881
1882 len = cur + len;
1883 while (cur < len) {
1884 if ((cur & 31) == 0 && (len - cur) >= 32) {
1885 /* fast path: set whole word at once */
1886 addr = bm + (cur >> 3);
1887 *addr = 0xffffffff;
1888 cur += 32;
1889 continue;
1890 }
1891 mb_set_bit(bit: cur, addr: bm);
1892 cur++;
1893 }
1894}
1895
1896static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1897{
1898 if (mb_test_bit(bit: *bit + side, addr: bitmap)) {
1899 mb_clear_bit(bit: *bit, addr: bitmap);
1900 (*bit) -= side;
1901 return 1;
1902 }
1903 else {
1904 (*bit) += side;
1905 mb_set_bit(bit: *bit, addr: bitmap);
1906 return -1;
1907 }
1908}
1909
1910static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1911{
1912 int max;
1913 int order = 1;
1914 void *buddy = mb_find_buddy(e4b, order, max: &max);
1915
1916 while (buddy) {
1917 void *buddy2;
1918
1919 /* Bits in range [first; last] are known to be set since
1920 * corresponding blocks were allocated. Bits in range
1921 * (first; last) will stay set because they form buddies on
1922 * upper layer. We just deal with borders if they don't
1923 * align with upper layer and then go up.
1924 * Releasing entire group is all about clearing
1925 * single bit of highest order buddy.
1926 */
1927
1928 /* Example:
1929 * ---------------------------------
1930 * | 1 | 1 | 1 | 1 |
1931 * ---------------------------------
1932 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1933 * ---------------------------------
1934 * 0 1 2 3 4 5 6 7
1935 * \_____________________/
1936 *
1937 * Neither [1] nor [6] is aligned to above layer.
1938 * Left neighbour [0] is free, so mark it busy,
1939 * decrease bb_counters and extend range to
1940 * [0; 6]
1941 * Right neighbour [7] is busy. It can't be coaleasced with [6], so
1942 * mark [6] free, increase bb_counters and shrink range to
1943 * [0; 5].
1944 * Then shift range to [0; 2], go up and do the same.
1945 */
1946
1947
1948 if (first & 1)
1949 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(bit: &first, bitmap: buddy, side: -1);
1950 if (!(last & 1))
1951 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(bit: &last, bitmap: buddy, side: 1);
1952 if (first > last)
1953 break;
1954 order++;
1955
1956 buddy2 = mb_find_buddy(e4b, order, max: &max);
1957 if (!buddy2) {
1958 mb_clear_bits(bm: buddy, cur: first, len: last - first + 1);
1959 e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1960 break;
1961 }
1962 first >>= 1;
1963 last >>= 1;
1964 buddy = buddy2;
1965 }
1966}
1967
1968static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1969 int first, int count)
1970{
1971 int left_is_free = 0;
1972 int right_is_free = 0;
1973 int block;
1974 int last = first + count - 1;
1975 struct super_block *sb = e4b->bd_sb;
1976
1977 if (WARN_ON(count == 0))
1978 return;
1979 BUG_ON(last >= (sb->s_blocksize << 3));
1980 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1981 /* Don't bother if the block group is corrupt. */
1982 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1983 return;
1984
1985 mb_check_buddy(e4b);
1986 mb_free_blocks_double(inode, e4b, first, count);
1987
1988 /* access memory sequentially: check left neighbour,
1989 * clear range and then check right neighbour
1990 */
1991 if (first != 0)
1992 left_is_free = !mb_test_bit(bit: first - 1, addr: e4b->bd_bitmap);
1993 block = mb_test_and_clear_bits(bm: e4b->bd_bitmap, cur: first, len: count);
1994 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1995 right_is_free = !mb_test_bit(bit: last + 1, addr: e4b->bd_bitmap);
1996
1997 if (unlikely(block != -1)) {
1998 struct ext4_sb_info *sbi = EXT4_SB(sb);
1999 ext4_fsblk_t blocknr;
2000
2001 /*
2002 * Fastcommit replay can free already freed blocks which
2003 * corrupts allocation info. Regenerate it.
2004 */
2005 if (sbi->s_mount_state & EXT4_FC_REPLAY) {
2006 mb_regenerate_buddy(e4b);
2007 goto check;
2008 }
2009
2010 blocknr = ext4_group_first_block_no(sb, group_no: e4b->bd_group);
2011 blocknr += EXT4_C2B(sbi, block);
2012 ext4_mark_group_bitmap_corrupted(sb, block_group: e4b->bd_group,
2013 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2014 ext4_grp_locked_error(sb, e4b->bd_group,
2015 inode ? inode->i_ino : 0, blocknr,
2016 "freeing already freed block (bit %u); block bitmap corrupt.",
2017 block);
2018 return;
2019 }
2020
2021 this_cpu_inc(discard_pa_seq);
2022 e4b->bd_info->bb_free += count;
2023 if (first < e4b->bd_info->bb_first_free)
2024 e4b->bd_info->bb_first_free = first;
2025
2026 /* let's maintain fragments counter */
2027 if (left_is_free && right_is_free)
2028 e4b->bd_info->bb_fragments--;
2029 else if (!left_is_free && !right_is_free)
2030 e4b->bd_info->bb_fragments++;
2031
2032 /* buddy[0] == bd_bitmap is a special case, so handle
2033 * it right away and let mb_buddy_mark_free stay free of
2034 * zero order checks.
2035 * Check if neighbours are to be coaleasced,
2036 * adjust bitmap bb_counters and borders appropriately.
2037 */
2038 if (first & 1) {
2039 first += !left_is_free;
2040 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
2041 }
2042 if (!(last & 1)) {
2043 last -= !right_is_free;
2044 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
2045 }
2046
2047 if (first <= last)
2048 mb_buddy_mark_free(e4b, first: first >> 1, last: last >> 1);
2049
2050 mb_set_largest_free_order(sb, grp: e4b->bd_info);
2051 mb_update_avg_fragment_size(sb, grp: e4b->bd_info);
2052check:
2053 mb_check_buddy(e4b);
2054}
2055
2056static int mb_find_extent(struct ext4_buddy *e4b, int block,
2057 int needed, struct ext4_free_extent *ex)
2058{
2059 int max, order, next;
2060 void *buddy;
2061
2062 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
2063 BUG_ON(ex == NULL);
2064
2065 buddy = mb_find_buddy(e4b, order: 0, max: &max);
2066 BUG_ON(buddy == NULL);
2067 BUG_ON(block >= max);
2068 if (mb_test_bit(bit: block, addr: buddy)) {
2069 ex->fe_len = 0;
2070 ex->fe_start = 0;
2071 ex->fe_group = 0;
2072 return 0;
2073 }
2074
2075 /* find actual order */
2076 order = mb_find_order_for_block(e4b, block);
2077
2078 ex->fe_len = (1 << order) - (block & ((1 << order) - 1));
2079 ex->fe_start = block;
2080 ex->fe_group = e4b->bd_group;
2081
2082 block = block >> order;
2083
2084 while (needed > ex->fe_len &&
2085 mb_find_buddy(e4b, order, max: &max)) {
2086
2087 if (block + 1 >= max)
2088 break;
2089
2090 next = (block + 1) * (1 << order);
2091 if (mb_test_bit(bit: next, addr: e4b->bd_bitmap))
2092 break;
2093
2094 order = mb_find_order_for_block(e4b, block: next);
2095
2096 block = next >> order;
2097 ex->fe_len += 1 << order;
2098 }
2099
2100 if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
2101 /* Should never happen! (but apparently sometimes does?!?) */
2102 WARN_ON(1);
2103 ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0,
2104 "corruption or bug in mb_find_extent "
2105 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
2106 block, order, needed, ex->fe_group, ex->fe_start,
2107 ex->fe_len, ex->fe_logical);
2108 ex->fe_len = 0;
2109 ex->fe_start = 0;
2110 ex->fe_group = 0;
2111 }
2112 return ex->fe_len;
2113}
2114
2115static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
2116{
2117 int ord;
2118 int mlen = 0;
2119 int max = 0;
2120 int start = ex->fe_start;
2121 int len = ex->fe_len;
2122 unsigned ret = 0;
2123 int len0 = len;
2124 void *buddy;
2125 int ord_start, ord_end;
2126
2127 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
2128 BUG_ON(e4b->bd_group != ex->fe_group);
2129 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
2130 mb_check_buddy(e4b);
2131 mb_mark_used_double(e4b, first: start, count: len);
2132
2133 this_cpu_inc(discard_pa_seq);
2134 e4b->bd_info->bb_free -= len;
2135 if (e4b->bd_info->bb_first_free == start)
2136 e4b->bd_info->bb_first_free += len;
2137
2138 /* let's maintain fragments counter */
2139 if (start != 0)
2140 mlen = !mb_test_bit(bit: start - 1, addr: e4b->bd_bitmap);
2141 if (start + len < EXT4_SB(sb: e4b->bd_sb)->s_mb_maxs[0])
2142 max = !mb_test_bit(bit: start + len, addr: e4b->bd_bitmap);
2143 if (mlen && max)
2144 e4b->bd_info->bb_fragments++;
2145 else if (!mlen && !max)
2146 e4b->bd_info->bb_fragments--;
2147
2148 /* let's maintain buddy itself */
2149 while (len) {
2150 ord = mb_find_order_for_block(e4b, block: start);
2151
2152 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
2153 /* the whole chunk may be allocated at once! */
2154 mlen = 1 << ord;
2155 buddy = mb_find_buddy(e4b, order: ord, max: &max);
2156 BUG_ON((start >> ord) >= max);
2157 mb_set_bit(bit: start >> ord, addr: buddy);
2158 e4b->bd_info->bb_counters[ord]--;
2159 start += mlen;
2160 len -= mlen;
2161 BUG_ON(len < 0);
2162 continue;
2163 }
2164
2165 /* store for history */
2166 if (ret == 0)
2167 ret = len | (ord << 16);
2168
2169 BUG_ON(ord <= 0);
2170 buddy = mb_find_buddy(e4b, order: ord, max: &max);
2171 mb_set_bit(bit: start >> ord, addr: buddy);
2172 e4b->bd_info->bb_counters[ord]--;
2173
2174 ord_start = (start >> ord) << ord;
2175 ord_end = ord_start + (1 << ord);
2176 /* first chunk */
2177 if (start > ord_start)
2178 ext4_mb_mark_free_simple(sb: e4b->bd_sb, buddy: e4b->bd_buddy,
2179 first: ord_start, len: start - ord_start,
2180 grp: e4b->bd_info);
2181
2182 /* last chunk */
2183 if (start + len < ord_end) {
2184 ext4_mb_mark_free_simple(sb: e4b->bd_sb, buddy: e4b->bd_buddy,
2185 first: start + len,
2186 len: ord_end - (start + len),
2187 grp: e4b->bd_info);
2188 break;
2189 }
2190 len = start + len - ord_end;
2191 start = ord_end;
2192 }
2193 mb_set_largest_free_order(sb: e4b->bd_sb, grp: e4b->bd_info);
2194
2195 mb_update_avg_fragment_size(sb: e4b->bd_sb, grp: e4b->bd_info);
2196 mb_set_bits(bm: e4b->bd_bitmap, cur: ex->fe_start, len: len0);
2197 mb_check_buddy(e4b);
2198
2199 return ret;
2200}
2201
2202/*
2203 * Must be called under group lock!
2204 */
2205static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
2206 struct ext4_buddy *e4b)
2207{
2208 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
2209 int ret;
2210
2211 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
2212 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2213
2214 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
2215 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
2216 ret = mb_mark_used(e4b, ex: &ac->ac_b_ex);
2217
2218 /* preallocation can change ac_b_ex, thus we store actually
2219 * allocated blocks for history */
2220 ac->ac_f_ex = ac->ac_b_ex;
2221
2222 ac->ac_status = AC_STATUS_FOUND;
2223 ac->ac_tail = ret & 0xffff;
2224 ac->ac_buddy = ret >> 16;
2225
2226 /*
2227 * take the page reference. We want the page to be pinned
2228 * so that we don't get a ext4_mb_init_cache_call for this
2229 * group until we update the bitmap. That would mean we
2230 * double allocate blocks. The reference is dropped
2231 * in ext4_mb_release_context
2232 */
2233 ac->ac_bitmap_folio = e4b->bd_bitmap_folio;
2234 folio_get(folio: ac->ac_bitmap_folio);
2235 ac->ac_buddy_folio = e4b->bd_buddy_folio;
2236 folio_get(folio: ac->ac_buddy_folio);
2237 /* store last allocated for subsequent stream allocation */
2238 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2239 int hash = ac->ac_inode->i_ino % sbi->s_mb_nr_global_goals;
2240
2241 WRITE_ONCE(sbi->s_mb_last_groups[hash], ac->ac_f_ex.fe_group);
2242 }
2243
2244 /*
2245 * As we've just preallocated more space than
2246 * user requested originally, we store allocated
2247 * space in a special descriptor.
2248 */
2249 if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
2250 ext4_mb_new_preallocation(ac);
2251
2252}
2253
2254static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
2255 struct ext4_buddy *e4b,
2256 int finish_group)
2257{
2258 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
2259 struct ext4_free_extent *bex = &ac->ac_b_ex;
2260 struct ext4_free_extent *gex = &ac->ac_g_ex;
2261
2262 if (ac->ac_status == AC_STATUS_FOUND)
2263 return;
2264 /*
2265 * We don't want to scan for a whole year
2266 */
2267 if (ac->ac_found > sbi->s_mb_max_to_scan &&
2268 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2269 ac->ac_status = AC_STATUS_BREAK;
2270 return;
2271 }
2272
2273 /*
2274 * Haven't found good chunk so far, let's continue
2275 */
2276 if (bex->fe_len < gex->fe_len)
2277 return;
2278
2279 if (finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
2280 ext4_mb_use_best_found(ac, e4b);
2281}
2282
2283/*
2284 * The routine checks whether found extent is good enough. If it is,
2285 * then the extent gets marked used and flag is set to the context
2286 * to stop scanning. Otherwise, the extent is compared with the
2287 * previous found extent and if new one is better, then it's stored
2288 * in the context. Later, the best found extent will be used, if
2289 * mballoc can't find good enough extent.
2290 *
2291 * The algorithm used is roughly as follows:
2292 *
2293 * * If free extent found is exactly as big as goal, then
2294 * stop the scan and use it immediately
2295 *
2296 * * If free extent found is smaller than goal, then keep retrying
2297 * upto a max of sbi->s_mb_max_to_scan times (default 200). After
2298 * that stop scanning and use whatever we have.
2299 *
2300 * * If free extent found is bigger than goal, then keep retrying
2301 * upto a max of sbi->s_mb_min_to_scan times (default 10) before
2302 * stopping the scan and using the extent.
2303 *
2304 *
2305 * FIXME: real allocation policy is to be designed yet!
2306 */
2307static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
2308 struct ext4_free_extent *ex,
2309 struct ext4_buddy *e4b)
2310{
2311 struct ext4_free_extent *bex = &ac->ac_b_ex;
2312 struct ext4_free_extent *gex = &ac->ac_g_ex;
2313
2314 BUG_ON(ex->fe_len <= 0);
2315 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2316 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2317 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
2318
2319 ac->ac_found++;
2320 ac->ac_cX_found[ac->ac_criteria]++;
2321
2322 /*
2323 * The special case - take what you catch first
2324 */
2325 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2326 *bex = *ex;
2327 ext4_mb_use_best_found(ac, e4b);
2328 return;
2329 }
2330
2331 /*
2332 * Let's check whether the chuck is good enough
2333 */
2334 if (ex->fe_len == gex->fe_len) {
2335 *bex = *ex;
2336 ext4_mb_use_best_found(ac, e4b);
2337 return;
2338 }
2339
2340 /*
2341 * If this is first found extent, just store it in the context
2342 */
2343 if (bex->fe_len == 0) {
2344 *bex = *ex;
2345 return;
2346 }
2347
2348 /*
2349 * If new found extent is better, store it in the context
2350 */
2351 if (bex->fe_len < gex->fe_len) {
2352 /* if the request isn't satisfied, any found extent
2353 * larger than previous best one is better */
2354 if (ex->fe_len > bex->fe_len)
2355 *bex = *ex;
2356 } else if (ex->fe_len > gex->fe_len) {
2357 /* if the request is satisfied, then we try to find
2358 * an extent that still satisfy the request, but is
2359 * smaller than previous one */
2360 if (ex->fe_len < bex->fe_len)
2361 *bex = *ex;
2362 }
2363
2364 ext4_mb_check_limits(ac, e4b, finish_group: 0);
2365}
2366
2367static noinline_for_stack
2368void ext4_mb_try_best_found(struct ext4_allocation_context *ac,
2369 struct ext4_buddy *e4b)
2370{
2371 struct ext4_free_extent ex = ac->ac_b_ex;
2372 ext4_group_t group = ex.fe_group;
2373 int max;
2374 int err;
2375
2376 BUG_ON(ex.fe_len <= 0);
2377 err = ext4_mb_load_buddy(sb: ac->ac_sb, group, e4b);
2378 if (err)
2379 return;
2380
2381 ext4_lock_group(sb: ac->ac_sb, group);
2382 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
2383 goto out;
2384
2385 max = mb_find_extent(e4b, block: ex.fe_start, needed: ex.fe_len, ex: &ex);
2386
2387 if (max > 0) {
2388 ac->ac_b_ex = ex;
2389 ext4_mb_use_best_found(ac, e4b);
2390 }
2391
2392out:
2393 ext4_unlock_group(sb: ac->ac_sb, group);
2394 ext4_mb_unload_buddy(e4b);
2395}
2396
2397static noinline_for_stack
2398int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
2399 struct ext4_buddy *e4b)
2400{
2401 ext4_group_t group = ac->ac_g_ex.fe_group;
2402 int max;
2403 int err;
2404 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
2405 struct ext4_group_info *grp = ext4_get_group_info(sb: ac->ac_sb, group);
2406 struct ext4_free_extent ex;
2407
2408 if (!grp)
2409 return -EFSCORRUPTED;
2410 if (!(ac->ac_flags & (EXT4_MB_HINT_TRY_GOAL | EXT4_MB_HINT_GOAL_ONLY)))
2411 return 0;
2412 if (grp->bb_free == 0)
2413 return 0;
2414
2415 err = ext4_mb_load_buddy(sb: ac->ac_sb, group, e4b);
2416 if (err)
2417 return err;
2418
2419 ext4_lock_group(sb: ac->ac_sb, group);
2420 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
2421 goto out;
2422
2423 max = mb_find_extent(e4b, block: ac->ac_g_ex.fe_start,
2424 needed: ac->ac_g_ex.fe_len, ex: &ex);
2425 ex.fe_logical = 0xDEADFA11; /* debug value */
2426
2427 if (max >= ac->ac_g_ex.fe_len &&
2428 ac->ac_g_ex.fe_len == EXT4_NUM_B2C(sbi, sbi->s_stripe)) {
2429 ext4_fsblk_t start;
2430
2431 start = ext4_grp_offs_to_block(sb: ac->ac_sb, fex: &ex);
2432 /* use do_div to get remainder (would be 64-bit modulo) */
2433 if (do_div(start, sbi->s_stripe) == 0) {
2434 ac->ac_found++;
2435 ac->ac_b_ex = ex;
2436 ext4_mb_use_best_found(ac, e4b);
2437 }
2438 } else if (max >= ac->ac_g_ex.fe_len) {
2439 BUG_ON(ex.fe_len <= 0);
2440 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2441 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2442 ac->ac_found++;
2443 ac->ac_b_ex = ex;
2444 ext4_mb_use_best_found(ac, e4b);
2445 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
2446 /* Sometimes, caller may want to merge even small
2447 * number of blocks to an existing extent */
2448 BUG_ON(ex.fe_len <= 0);
2449 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2450 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2451 ac->ac_found++;
2452 ac->ac_b_ex = ex;
2453 ext4_mb_use_best_found(ac, e4b);
2454 }
2455out:
2456 ext4_unlock_group(sb: ac->ac_sb, group);
2457 ext4_mb_unload_buddy(e4b);
2458
2459 return 0;
2460}
2461
2462/*
2463 * The routine scans buddy structures (not bitmap!) from given order
2464 * to max order and tries to find big enough chunk to satisfy the req
2465 */
2466static noinline_for_stack
2467void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
2468 struct ext4_buddy *e4b)
2469{
2470 struct super_block *sb = ac->ac_sb;
2471 struct ext4_group_info *grp = e4b->bd_info;
2472 void *buddy;
2473 int i;
2474 int k;
2475 int max;
2476
2477 BUG_ON(ac->ac_2order <= 0);
2478 for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) {
2479 if (grp->bb_counters[i] == 0)
2480 continue;
2481
2482 buddy = mb_find_buddy(e4b, order: i, max: &max);
2483 if (WARN_RATELIMIT(buddy == NULL,
2484 "ext4: mb_simple_scan_group: mb_find_buddy failed, (%d)\n", i))
2485 continue;
2486
2487 k = mb_find_next_zero_bit(addr: buddy, max, start: 0);
2488 if (k >= max) {
2489 ext4_mark_group_bitmap_corrupted(sb: ac->ac_sb,
2490 block_group: e4b->bd_group,
2491 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2492 ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0,
2493 "%d free clusters of order %d. But found 0",
2494 grp->bb_counters[i], i);
2495 break;
2496 }
2497 ac->ac_found++;
2498 ac->ac_cX_found[ac->ac_criteria]++;
2499
2500 ac->ac_b_ex.fe_len = 1 << i;
2501 ac->ac_b_ex.fe_start = k << i;
2502 ac->ac_b_ex.fe_group = e4b->bd_group;
2503
2504 ext4_mb_use_best_found(ac, e4b);
2505
2506 BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len);
2507
2508 if (EXT4_SB(sb)->s_mb_stats)
2509 atomic_inc(v: &EXT4_SB(sb)->s_bal_2orders);
2510
2511 break;
2512 }
2513}
2514
2515/*
2516 * The routine scans the group and measures all found extents.
2517 * In order to optimize scanning, caller must pass number of
2518 * free blocks in the group, so the routine can know upper limit.
2519 */
2520static noinline_for_stack
2521void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
2522 struct ext4_buddy *e4b)
2523{
2524 struct super_block *sb = ac->ac_sb;
2525 void *bitmap = e4b->bd_bitmap;
2526 struct ext4_free_extent ex;
2527 int i, j, freelen;
2528 int free;
2529
2530 free = e4b->bd_info->bb_free;
2531 if (WARN_ON(free <= 0))
2532 return;
2533
2534 i = e4b->bd_info->bb_first_free;
2535
2536 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
2537 i = mb_find_next_zero_bit(addr: bitmap,
2538 EXT4_CLUSTERS_PER_GROUP(sb), start: i);
2539 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
2540 /*
2541 * IF we have corrupt bitmap, we won't find any
2542 * free blocks even though group info says we
2543 * have free blocks
2544 */
2545 ext4_mark_group_bitmap_corrupted(sb, block_group: e4b->bd_group,
2546 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2547 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2548 "%d free clusters as per "
2549 "group info. But bitmap says 0",
2550 free);
2551 break;
2552 }
2553
2554 if (!ext4_mb_cr_expensive(cr: ac->ac_criteria)) {
2555 /*
2556 * In CR_GOAL_LEN_FAST and CR_BEST_AVAIL_LEN, we are
2557 * sure that this group will have a large enough
2558 * continuous free extent, so skip over the smaller free
2559 * extents
2560 */
2561 j = mb_find_next_bit(addr: bitmap,
2562 EXT4_CLUSTERS_PER_GROUP(sb), start: i);
2563 freelen = j - i;
2564
2565 if (freelen < ac->ac_g_ex.fe_len) {
2566 i = j;
2567 free -= freelen;
2568 continue;
2569 }
2570 }
2571
2572 mb_find_extent(e4b, block: i, needed: ac->ac_g_ex.fe_len, ex: &ex);
2573 if (WARN_ON(ex.fe_len <= 0))
2574 break;
2575 if (free < ex.fe_len) {
2576 ext4_mark_group_bitmap_corrupted(sb, block_group: e4b->bd_group,
2577 EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2578 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2579 "%d free clusters as per "
2580 "group info. But got %d blocks",
2581 free, ex.fe_len);
2582 /*
2583 * The number of free blocks differs. This mostly
2584 * indicate that the bitmap is corrupt. So exit
2585 * without claiming the space.
2586 */
2587 break;
2588 }
2589 ex.fe_logical = 0xDEADC0DE; /* debug value */
2590 ext4_mb_measure_extent(ac, ex: &ex, e4b);
2591
2592 i += ex.fe_len;
2593 free -= ex.fe_len;
2594 }
2595
2596 ext4_mb_check_limits(ac, e4b, finish_group: 1);
2597}
2598
2599/*
2600 * This is a special case for storages like raid5
2601 * we try to find stripe-aligned chunks for stripe-size-multiple requests
2602 */
2603static noinline_for_stack
2604void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
2605 struct ext4_buddy *e4b)
2606{
2607 struct super_block *sb = ac->ac_sb;
2608 struct ext4_sb_info *sbi = EXT4_SB(sb);
2609 void *bitmap = e4b->bd_bitmap;
2610 struct ext4_free_extent ex;
2611 ext4_fsblk_t first_group_block;
2612 ext4_fsblk_t a;
2613 ext4_grpblk_t i, stripe;
2614 int max;
2615
2616 BUG_ON(sbi->s_stripe == 0);
2617
2618 /* find first stripe-aligned block in group */
2619 first_group_block = ext4_group_first_block_no(sb, group_no: e4b->bd_group);
2620
2621 a = first_group_block + sbi->s_stripe - 1;
2622 do_div(a, sbi->s_stripe);
2623 i = (a * sbi->s_stripe) - first_group_block;
2624
2625 stripe = EXT4_NUM_B2C(sbi, sbi->s_stripe);
2626 i = EXT4_B2C(sbi, i);
2627 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2628 if (!mb_test_bit(bit: i, addr: bitmap)) {
2629 max = mb_find_extent(e4b, block: i, needed: stripe, ex: &ex);
2630 if (max >= stripe) {
2631 ac->ac_found++;
2632 ac->ac_cX_found[ac->ac_criteria]++;
2633 ex.fe_logical = 0xDEADF00D; /* debug value */
2634 ac->ac_b_ex = ex;
2635 ext4_mb_use_best_found(ac, e4b);
2636 break;
2637 }
2638 }
2639 i += stripe;
2640 }
2641}
2642
2643static void __ext4_mb_scan_group(struct ext4_allocation_context *ac)
2644{
2645 bool is_stripe_aligned;
2646 struct ext4_sb_info *sbi;
2647 enum criteria cr = ac->ac_criteria;
2648
2649 ac->ac_groups_scanned++;
2650 if (cr == CR_POWER2_ALIGNED)
2651 return ext4_mb_simple_scan_group(ac, e4b: ac->ac_e4b);
2652
2653 sbi = EXT4_SB(sb: ac->ac_sb);
2654 is_stripe_aligned = false;
2655 if ((sbi->s_stripe >= sbi->s_cluster_ratio) &&
2656 !(ac->ac_g_ex.fe_len % EXT4_NUM_B2C(sbi, sbi->s_stripe)))
2657 is_stripe_aligned = true;
2658
2659 if ((cr == CR_GOAL_LEN_FAST || cr == CR_BEST_AVAIL_LEN) &&
2660 is_stripe_aligned)
2661 ext4_mb_scan_aligned(ac, e4b: ac->ac_e4b);
2662
2663 if (ac->ac_status == AC_STATUS_CONTINUE)
2664 ext4_mb_complex_scan_group(ac, e4b: ac->ac_e4b);
2665}
2666
2667/*
2668 * This is also called BEFORE we load the buddy bitmap.
2669 * Returns either 1 or 0 indicating that the group is either suitable
2670 * for the allocation or not.
2671 */
2672static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
2673 ext4_group_t group, enum criteria cr)
2674{
2675 ext4_grpblk_t free, fragments;
2676 int flex_size = ext4_flex_bg_size(sbi: EXT4_SB(sb: ac->ac_sb));
2677 struct ext4_group_info *grp = ext4_get_group_info(sb: ac->ac_sb, group);
2678
2679 BUG_ON(cr < CR_POWER2_ALIGNED || cr >= EXT4_MB_NUM_CRS);
2680
2681 if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2682 return false;
2683
2684 free = grp->bb_free;
2685 if (free == 0)
2686 return false;
2687
2688 fragments = grp->bb_fragments;
2689 if (fragments == 0)
2690 return false;
2691
2692 switch (cr) {
2693 case CR_POWER2_ALIGNED:
2694 BUG_ON(ac->ac_2order == 0);
2695
2696 /* Avoid using the first bg of a flexgroup for data files */
2697 if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2698 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2699 ((group % flex_size) == 0))
2700 return false;
2701
2702 if (free < ac->ac_g_ex.fe_len)
2703 return false;
2704
2705 if (ac->ac_2order >= MB_NUM_ORDERS(ac->ac_sb))
2706 return true;
2707
2708 if (grp->bb_largest_free_order < ac->ac_2order)
2709 return false;
2710
2711 return true;
2712 case CR_GOAL_LEN_FAST:
2713 case CR_BEST_AVAIL_LEN:
2714 if ((free / fragments) >= ac->ac_g_ex.fe_len)
2715 return true;
2716 break;
2717 case CR_GOAL_LEN_SLOW:
2718 if (free >= ac->ac_g_ex.fe_len)
2719 return true;
2720 break;
2721 case CR_ANY_FREE:
2722 return true;
2723 default:
2724 BUG();
2725 }
2726
2727 return false;
2728}
2729
2730/*
2731 * This could return negative error code if something goes wrong
2732 * during ext4_mb_init_group(). This should not be called with
2733 * ext4_lock_group() held.
2734 *
2735 * Note: because we are conditionally operating with the group lock in
2736 * the EXT4_MB_STRICT_CHECK case, we need to fake out sparse in this
2737 * function using __acquire and __release. This means we need to be
2738 * super careful before messing with the error path handling via "goto
2739 * out"!
2740 */
2741static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac,
2742 ext4_group_t group, enum criteria cr)
2743{
2744 struct ext4_group_info *grp = ext4_get_group_info(sb: ac->ac_sb, group);
2745 struct super_block *sb = ac->ac_sb;
2746 struct ext4_sb_info *sbi = EXT4_SB(sb);
2747 bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK;
2748 ext4_grpblk_t free;
2749 int ret = 0;
2750
2751 if (!grp)
2752 return -EFSCORRUPTED;
2753 if (sbi->s_mb_stats)
2754 atomic64_inc(v: &sbi->s_bal_cX_groups_considered[ac->ac_criteria]);
2755 if (should_lock) {
2756 ext4_lock_group(sb, group);
2757 __release(ext4_group_lock_ptr(sb, group));
2758 }
2759 free = grp->bb_free;
2760 if (free == 0)
2761 goto out;
2762 /*
2763 * In all criterias except CR_ANY_FREE we try to avoid groups that
2764 * can't possibly satisfy the full goal request due to insufficient
2765 * free blocks.
2766 */
2767 if (cr < CR_ANY_FREE && free < ac->ac_g_ex.fe_len)
2768 goto out;
2769 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2770 goto out;
2771 if (should_lock) {
2772 __acquire(ext4_group_lock_ptr(sb, group));
2773 ext4_unlock_group(sb, group);
2774 }
2775
2776 /* We only do this if the grp has never been initialized */
2777 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2778 struct ext4_group_desc *gdp =
2779 ext4_get_group_desc(sb, block_group: group, NULL);
2780 int ret;
2781
2782 /*
2783 * CR_POWER2_ALIGNED/CR_GOAL_LEN_FAST is a very optimistic
2784 * search to find large good chunks almost for free. If buddy
2785 * data is not ready, then this optimization makes no sense. But
2786 * we never skip the first block group in a flex_bg, since this
2787 * gets used for metadata block allocation, and we want to make
2788 * sure we locate metadata blocks in the first block group in
2789 * the flex_bg if possible.
2790 */
2791 if (!ext4_mb_cr_expensive(cr) &&
2792 (!sbi->s_log_groups_per_flex ||
2793 ((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) &&
2794 !(ext4_has_group_desc_csum(sb) &&
2795 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))))
2796 return 0;
2797 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
2798 if (ret)
2799 return ret;
2800 }
2801
2802 if (should_lock) {
2803 ext4_lock_group(sb, group);
2804 __release(ext4_group_lock_ptr(sb, group));
2805 }
2806 ret = ext4_mb_good_group(ac, group, cr);
2807out:
2808 if (should_lock) {
2809 __acquire(ext4_group_lock_ptr(sb, group));
2810 ext4_unlock_group(sb, group);
2811 }
2812 return ret;
2813}
2814
2815/*
2816 * Start prefetching @nr block bitmaps starting at @group.
2817 * Return the next group which needs to be prefetched.
2818 */
2819ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group,
2820 unsigned int nr, int *cnt)
2821{
2822 ext4_group_t ngroups = ext4_get_groups_count(sb);
2823 struct buffer_head *bh;
2824 struct blk_plug plug;
2825
2826 blk_start_plug(&plug);
2827 while (nr-- > 0) {
2828 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, block_group: group,
2829 NULL);
2830 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
2831
2832 /*
2833 * Prefetch block groups with free blocks; but don't
2834 * bother if it is marked uninitialized on disk, since
2835 * it won't require I/O to read. Also only try to
2836 * prefetch once, so we avoid getblk() call, which can
2837 * be expensive.
2838 */
2839 if (gdp && grp && !EXT4_MB_GRP_TEST_AND_SET_READ(grp) &&
2840 EXT4_MB_GRP_NEED_INIT(grp) &&
2841 ext4_free_group_clusters(sb, bg: gdp) > 0 ) {
2842 bh = ext4_read_block_bitmap_nowait(sb, block_group: group, ignore_locked: true);
2843 if (bh && !IS_ERR(ptr: bh)) {
2844 if (!buffer_uptodate(bh) && cnt)
2845 (*cnt)++;
2846 brelse(bh);
2847 }
2848 }
2849 if (++group >= ngroups)
2850 group = 0;
2851 }
2852 blk_finish_plug(&plug);
2853 return group;
2854}
2855
2856/*
2857 * Batch reads of the block allocation bitmaps to get
2858 * multiple READs in flight; limit prefetching at inexpensive
2859 * CR, otherwise mballoc can spend a lot of time loading
2860 * imperfect groups
2861 */
2862static void ext4_mb_might_prefetch(struct ext4_allocation_context *ac,
2863 ext4_group_t group)
2864{
2865 struct ext4_sb_info *sbi;
2866
2867 if (ac->ac_prefetch_grp != group)
2868 return;
2869
2870 sbi = EXT4_SB(sb: ac->ac_sb);
2871 if (ext4_mb_cr_expensive(cr: ac->ac_criteria) ||
2872 ac->ac_prefetch_ios < sbi->s_mb_prefetch_limit) {
2873 unsigned int nr = sbi->s_mb_prefetch;
2874
2875 if (ext4_has_feature_flex_bg(sb: ac->ac_sb)) {
2876 nr = 1 << sbi->s_log_groups_per_flex;
2877 nr -= group & (nr - 1);
2878 nr = umin(nr, sbi->s_mb_prefetch);
2879 }
2880
2881 ac->ac_prefetch_nr = nr;
2882 ac->ac_prefetch_grp = ext4_mb_prefetch(sb: ac->ac_sb, group, nr,
2883 cnt: &ac->ac_prefetch_ios);
2884 }
2885}
2886
2887/*
2888 * Prefetching reads the block bitmap into the buffer cache; but we
2889 * need to make sure that the buddy bitmap in the page cache has been
2890 * initialized. Note that ext4_mb_init_group() will block if the I/O
2891 * is not yet completed, or indeed if it was not initiated by
2892 * ext4_mb_prefetch did not start the I/O.
2893 *
2894 * TODO: We should actually kick off the buddy bitmap setup in a work
2895 * queue when the buffer I/O is completed, so that we don't block
2896 * waiting for the block allocation bitmap read to finish when
2897 * ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator().
2898 */
2899void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
2900 unsigned int nr)
2901{
2902 struct ext4_group_desc *gdp;
2903 struct ext4_group_info *grp;
2904
2905 while (nr-- > 0) {
2906 if (!group)
2907 group = ext4_get_groups_count(sb);
2908 group--;
2909 gdp = ext4_get_group_desc(sb, block_group: group, NULL);
2910 grp = ext4_get_group_info(sb, group);
2911
2912 if (grp && gdp && EXT4_MB_GRP_NEED_INIT(grp) &&
2913 ext4_free_group_clusters(sb, bg: gdp) > 0) {
2914 if (ext4_mb_init_group(sb, group, GFP_NOFS))
2915 break;
2916 }
2917 }
2918}
2919
2920static int ext4_mb_scan_group(struct ext4_allocation_context *ac,
2921 ext4_group_t group)
2922{
2923 int ret;
2924 struct super_block *sb = ac->ac_sb;
2925 enum criteria cr = ac->ac_criteria;
2926
2927 ext4_mb_might_prefetch(ac, group);
2928
2929 /* prevent unnecessary buddy loading. */
2930 if (cr < CR_ANY_FREE && spin_is_locked(lock: ext4_group_lock_ptr(sb, group)))
2931 return 0;
2932
2933 /* This now checks without needing the buddy page */
2934 ret = ext4_mb_good_group_nolock(ac, group, cr);
2935 if (ret <= 0) {
2936 if (!ac->ac_first_err)
2937 ac->ac_first_err = ret;
2938 return 0;
2939 }
2940
2941 ret = ext4_mb_load_buddy(sb, group, e4b: ac->ac_e4b);
2942 if (ret)
2943 return ret;
2944
2945 /* skip busy group */
2946 if (cr >= CR_ANY_FREE)
2947 ext4_lock_group(sb, group);
2948 else if (!ext4_try_lock_group(sb, group))
2949 goto out_unload;
2950
2951 /* We need to check again after locking the block group. */
2952 if (unlikely(!ext4_mb_good_group(ac, group, cr)))
2953 goto out_unlock;
2954
2955 __ext4_mb_scan_group(ac);
2956
2957out_unlock:
2958 ext4_unlock_group(sb, group);
2959out_unload:
2960 ext4_mb_unload_buddy(e4b: ac->ac_e4b);
2961 return ret;
2962}
2963
2964static noinline_for_stack int
2965ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2966{
2967 ext4_group_t i;
2968 int err = 0;
2969 struct super_block *sb = ac->ac_sb;
2970 struct ext4_sb_info *sbi = EXT4_SB(sb);
2971 struct ext4_buddy e4b;
2972
2973 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2974
2975 /* first, try the goal */
2976 err = ext4_mb_find_by_goal(ac, e4b: &e4b);
2977 if (err || ac->ac_status == AC_STATUS_FOUND)
2978 goto out;
2979
2980 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2981 goto out;
2982
2983 /*
2984 * ac->ac_2order is set only if the fe_len is a power of 2
2985 * if ac->ac_2order is set we also set criteria to CR_POWER2_ALIGNED
2986 * so that we try exact allocation using buddy.
2987 */
2988 i = fls(x: ac->ac_g_ex.fe_len);
2989 ac->ac_2order = 0;
2990 /*
2991 * We search using buddy data only if the order of the request
2992 * is greater than equal to the sbi_s_mb_order2_reqs
2993 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2994 * We also support searching for power-of-two requests only for
2995 * requests upto maximum buddy size we have constructed.
2996 */
2997 if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) {
2998 if (is_power_of_2(n: ac->ac_g_ex.fe_len))
2999 ac->ac_2order = array_index_nospec(i - 1,
3000 MB_NUM_ORDERS(sb));
3001 }
3002
3003 /* if stream allocation is enabled, use global goal */
3004 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
3005 int hash = ac->ac_inode->i_ino % sbi->s_mb_nr_global_goals;
3006
3007 ac->ac_g_ex.fe_group = READ_ONCE(sbi->s_mb_last_groups[hash]);
3008 ac->ac_g_ex.fe_start = -1;
3009 ac->ac_flags &= ~EXT4_MB_HINT_TRY_GOAL;
3010 }
3011
3012 /*
3013 * Let's just scan groups to find more-less suitable blocks We
3014 * start with CR_GOAL_LEN_FAST, unless it is power of 2
3015 * aligned, in which case let's do that faster approach first.
3016 */
3017 ac->ac_criteria = CR_GOAL_LEN_FAST;
3018 if (ac->ac_2order)
3019 ac->ac_criteria = CR_POWER2_ALIGNED;
3020
3021 ac->ac_e4b = &e4b;
3022 ac->ac_prefetch_ios = 0;
3023 ac->ac_first_err = 0;
3024repeat:
3025 while (ac->ac_criteria < EXT4_MB_NUM_CRS) {
3026 err = ext4_mb_scan_groups(ac);
3027 if (err)
3028 goto out;
3029
3030 if (ac->ac_status != AC_STATUS_CONTINUE)
3031 break;
3032 }
3033
3034 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
3035 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
3036 /*
3037 * We've been searching too long. Let's try to allocate
3038 * the best chunk we've found so far
3039 */
3040 ext4_mb_try_best_found(ac, e4b: &e4b);
3041 if (ac->ac_status != AC_STATUS_FOUND) {
3042 int lost;
3043
3044 /*
3045 * Someone more lucky has already allocated it.
3046 * The only thing we can do is just take first
3047 * found block(s)
3048 */
3049 lost = atomic_inc_return(v: &sbi->s_mb_lost_chunks);
3050 mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n",
3051 ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start,
3052 ac->ac_b_ex.fe_len, lost);
3053
3054 ac->ac_b_ex.fe_group = 0;
3055 ac->ac_b_ex.fe_start = 0;
3056 ac->ac_b_ex.fe_len = 0;
3057 ac->ac_status = AC_STATUS_CONTINUE;
3058 ac->ac_flags |= EXT4_MB_HINT_FIRST;
3059 ac->ac_criteria = CR_ANY_FREE;
3060 goto repeat;
3061 }
3062 }
3063
3064 if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND) {
3065 atomic64_inc(v: &sbi->s_bal_cX_hits[ac->ac_criteria]);
3066 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC &&
3067 ac->ac_b_ex.fe_group == ac->ac_g_ex.fe_group)
3068 atomic_inc(v: &sbi->s_bal_stream_goals);
3069 }
3070out:
3071 if (!err && ac->ac_status != AC_STATUS_FOUND && ac->ac_first_err)
3072 err = ac->ac_first_err;
3073
3074 mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
3075 ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status,
3076 ac->ac_flags, ac->ac_criteria, err);
3077
3078 if (ac->ac_prefetch_nr)
3079 ext4_mb_prefetch_fini(sb, group: ac->ac_prefetch_grp, nr: ac->ac_prefetch_nr);
3080
3081 return err;
3082}
3083
3084static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
3085{
3086 struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3087 ext4_group_t group;
3088
3089 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
3090 return NULL;
3091 group = *pos + 1;
3092 return (void *) ((unsigned long) group);
3093}
3094
3095static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
3096{
3097 struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3098 ext4_group_t group;
3099
3100 ++*pos;
3101 if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
3102 return NULL;
3103 group = *pos + 1;
3104 return (void *) ((unsigned long) group);
3105}
3106
3107static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
3108{
3109 struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3110 ext4_group_t group = (ext4_group_t) ((unsigned long) v);
3111 int i, err;
3112 char nbuf[16];
3113 struct ext4_buddy e4b;
3114 struct ext4_group_info *grinfo;
3115 unsigned char blocksize_bits = min_t(unsigned char,
3116 sb->s_blocksize_bits,
3117 EXT4_MAX_BLOCK_LOG_SIZE);
3118 DEFINE_RAW_FLEX(struct ext4_group_info, sg, bb_counters,
3119 EXT4_MAX_BLOCK_LOG_SIZE + 2);
3120
3121 group--;
3122 if (group == 0)
3123 seq_puts(m: seq, s: "#group: free frags first ["
3124 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
3125 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
3126
3127 i = (blocksize_bits + 2) * sizeof(sg->bb_counters[0]) +
3128 sizeof(struct ext4_group_info);
3129
3130 grinfo = ext4_get_group_info(sb, group);
3131 if (!grinfo)
3132 return 0;
3133 /* Load the group info in memory only if not already loaded. */
3134 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
3135 err = ext4_mb_load_buddy(sb, group, e4b: &e4b);
3136 if (err) {
3137 seq_printf(m: seq, fmt: "#%-5u: %s\n", group, ext4_decode_error(NULL, errno: err, nbuf));
3138 return 0;
3139 }
3140 ext4_mb_unload_buddy(e4b: &e4b);
3141 }
3142
3143 /*
3144 * We care only about free space counters in the group info and
3145 * these are safe to access even after the buddy has been unloaded
3146 */
3147 memcpy(to: sg, from: grinfo, len: i);
3148 seq_printf(m: seq, fmt: "#%-5u: %-5u %-5u %-5u [", group, sg->bb_free,
3149 sg->bb_fragments, sg->bb_first_free);
3150 for (i = 0; i <= 13; i++)
3151 seq_printf(m: seq, fmt: " %-5u", i <= blocksize_bits + 1 ?
3152 sg->bb_counters[i] : 0);
3153 seq_puts(m: seq, s: " ]");
3154 if (EXT4_MB_GRP_BBITMAP_CORRUPT(sg))
3155 seq_puts(m: seq, s: " Block bitmap corrupted!");
3156 seq_putc(m: seq, c: '\n');
3157 return 0;
3158}
3159
3160static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
3161{
3162}
3163
3164const struct seq_operations ext4_mb_seq_groups_ops = {
3165 .start = ext4_mb_seq_groups_start,
3166 .next = ext4_mb_seq_groups_next,
3167 .stop = ext4_mb_seq_groups_stop,
3168 .show = ext4_mb_seq_groups_show,
3169};
3170
3171int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
3172{
3173 struct super_block *sb = seq->private;
3174 struct ext4_sb_info *sbi = EXT4_SB(sb);
3175
3176 seq_puts(m: seq, s: "mballoc:\n");
3177 if (!sbi->s_mb_stats) {
3178 seq_puts(m: seq, s: "\tmb stats collection turned off.\n");
3179 seq_puts(
3180 m: seq,
3181 s: "\tTo enable, please write \"1\" to sysfs file mb_stats.\n");
3182 return 0;
3183 }
3184 seq_printf(m: seq, fmt: "\treqs: %u\n", atomic_read(v: &sbi->s_bal_reqs));
3185 seq_printf(m: seq, fmt: "\tsuccess: %u\n", atomic_read(v: &sbi->s_bal_success));
3186
3187 seq_printf(m: seq, fmt: "\tgroups_scanned: %u\n",
3188 atomic_read(v: &sbi->s_bal_groups_scanned));
3189
3190 /* CR_POWER2_ALIGNED stats */
3191 seq_puts(m: seq, s: "\tcr_p2_aligned_stats:\n");
3192 seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3193 atomic64_read(v: &sbi->s_bal_cX_hits[CR_POWER2_ALIGNED]));
3194 seq_printf(
3195 m: seq, fmt: "\t\tgroups_considered: %llu\n",
3196 atomic64_read(
3197 v: &sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED]));
3198 seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3199 atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_POWER2_ALIGNED]));
3200 seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3201 atomic64_read(v: &sbi->s_bal_cX_failed[CR_POWER2_ALIGNED]));
3202
3203 /* CR_GOAL_LEN_FAST stats */
3204 seq_puts(m: seq, s: "\tcr_goal_fast_stats:\n");
3205 seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3206 atomic64_read(v: &sbi->s_bal_cX_hits[CR_GOAL_LEN_FAST]));
3207 seq_printf(m: seq, fmt: "\t\tgroups_considered: %llu\n",
3208 atomic64_read(
3209 v: &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_FAST]));
3210 seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3211 atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_FAST]));
3212 seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3213 atomic64_read(v: &sbi->s_bal_cX_failed[CR_GOAL_LEN_FAST]));
3214
3215 /* CR_BEST_AVAIL_LEN stats */
3216 seq_puts(m: seq, s: "\tcr_best_avail_stats:\n");
3217 seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3218 atomic64_read(v: &sbi->s_bal_cX_hits[CR_BEST_AVAIL_LEN]));
3219 seq_printf(
3220 m: seq, fmt: "\t\tgroups_considered: %llu\n",
3221 atomic64_read(
3222 v: &sbi->s_bal_cX_groups_considered[CR_BEST_AVAIL_LEN]));
3223 seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3224 atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_BEST_AVAIL_LEN]));
3225 seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3226 atomic64_read(v: &sbi->s_bal_cX_failed[CR_BEST_AVAIL_LEN]));
3227
3228 /* CR_GOAL_LEN_SLOW stats */
3229 seq_puts(m: seq, s: "\tcr_goal_slow_stats:\n");
3230 seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3231 atomic64_read(v: &sbi->s_bal_cX_hits[CR_GOAL_LEN_SLOW]));
3232 seq_printf(m: seq, fmt: "\t\tgroups_considered: %llu\n",
3233 atomic64_read(
3234 v: &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_SLOW]));
3235 seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3236 atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_SLOW]));
3237 seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3238 atomic64_read(v: &sbi->s_bal_cX_failed[CR_GOAL_LEN_SLOW]));
3239
3240 /* CR_ANY_FREE stats */
3241 seq_puts(m: seq, s: "\tcr_any_free_stats:\n");
3242 seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3243 atomic64_read(v: &sbi->s_bal_cX_hits[CR_ANY_FREE]));
3244 seq_printf(
3245 m: seq, fmt: "\t\tgroups_considered: %llu\n",
3246 atomic64_read(v: &sbi->s_bal_cX_groups_considered[CR_ANY_FREE]));
3247 seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3248 atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_ANY_FREE]));
3249 seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3250 atomic64_read(v: &sbi->s_bal_cX_failed[CR_ANY_FREE]));
3251
3252 /* Aggregates */
3253 seq_printf(m: seq, fmt: "\textents_scanned: %u\n",
3254 atomic_read(v: &sbi->s_bal_ex_scanned));
3255 seq_printf(m: seq, fmt: "\t\tgoal_hits: %u\n", atomic_read(v: &sbi->s_bal_goals));
3256 seq_printf(m: seq, fmt: "\t\tstream_goal_hits: %u\n",
3257 atomic_read(v: &sbi->s_bal_stream_goals));
3258 seq_printf(m: seq, fmt: "\t\tlen_goal_hits: %u\n",
3259 atomic_read(v: &sbi->s_bal_len_goals));
3260 seq_printf(m: seq, fmt: "\t\t2^n_hits: %u\n", atomic_read(v: &sbi->s_bal_2orders));
3261 seq_printf(m: seq, fmt: "\t\tbreaks: %u\n", atomic_read(v: &sbi->s_bal_breaks));
3262 seq_printf(m: seq, fmt: "\t\tlost: %u\n", atomic_read(v: &sbi->s_mb_lost_chunks));
3263 seq_printf(m: seq, fmt: "\tbuddies_generated: %u/%u\n",
3264 atomic_read(v: &sbi->s_mb_buddies_generated),
3265 ext4_get_groups_count(sb));
3266 seq_printf(m: seq, fmt: "\tbuddies_time_used: %llu\n",
3267 atomic64_read(v: &sbi->s_mb_generation_time));
3268 seq_printf(m: seq, fmt: "\tpreallocated: %u\n",
3269 atomic_read(v: &sbi->s_mb_preallocated));
3270 seq_printf(m: seq, fmt: "\tdiscarded: %u\n", atomic_read(v: &sbi->s_mb_discarded));
3271 return 0;
3272}
3273
3274static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos)
3275{
3276 struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3277 unsigned long position;
3278
3279 if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb))
3280 return NULL;
3281 position = *pos + 1;
3282 return (void *) ((unsigned long) position);
3283}
3284
3285static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos)
3286{
3287 struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3288 unsigned long position;
3289
3290 ++*pos;
3291 if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb))
3292 return NULL;
3293 position = *pos + 1;
3294 return (void *) ((unsigned long) position);
3295}
3296
3297static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v)
3298{
3299 struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3300 struct ext4_sb_info *sbi = EXT4_SB(sb);
3301 unsigned long position = ((unsigned long) v);
3302 struct ext4_group_info *grp;
3303 unsigned int count;
3304 unsigned long idx;
3305
3306 position--;
3307 if (position >= MB_NUM_ORDERS(sb)) {
3308 position -= MB_NUM_ORDERS(sb);
3309 if (position == 0)
3310 seq_puts(m: seq, s: "avg_fragment_size_lists:\n");
3311
3312 count = 0;
3313 xa_for_each(&sbi->s_mb_avg_fragment_size[position], idx, grp)
3314 count++;
3315 seq_printf(m: seq, fmt: "\tlist_order_%u_groups: %u\n",
3316 (unsigned int)position, count);
3317 return 0;
3318 }
3319
3320 if (position == 0) {
3321 seq_printf(m: seq, fmt: "optimize_scan: %d\n",
3322 test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0);
3323 seq_puts(m: seq, s: "max_free_order_lists:\n");
3324 }
3325 count = 0;
3326 xa_for_each(&sbi->s_mb_largest_free_orders[position], idx, grp)
3327 count++;
3328 seq_printf(m: seq, fmt: "\tlist_order_%u_groups: %u\n",
3329 (unsigned int)position, count);
3330
3331 return 0;
3332}
3333
3334static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v)
3335{
3336}
3337
3338const struct seq_operations ext4_mb_seq_structs_summary_ops = {
3339 .start = ext4_mb_seq_structs_summary_start,
3340 .next = ext4_mb_seq_structs_summary_next,
3341 .stop = ext4_mb_seq_structs_summary_stop,
3342 .show = ext4_mb_seq_structs_summary_show,
3343};
3344
3345static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
3346{
3347 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3348 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
3349
3350 BUG_ON(!cachep);
3351 return cachep;
3352}
3353
3354/*
3355 * Allocate the top-level s_group_info array for the specified number
3356 * of groups
3357 */
3358int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
3359{
3360 struct ext4_sb_info *sbi = EXT4_SB(sb);
3361 unsigned size;
3362 struct ext4_group_info ***old_groupinfo, ***new_groupinfo;
3363
3364 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
3365 EXT4_DESC_PER_BLOCK_BITS(sb);
3366 if (size <= sbi->s_group_info_size)
3367 return 0;
3368
3369 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
3370 new_groupinfo = kvzalloc(size, GFP_KERNEL);
3371 if (!new_groupinfo) {
3372 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
3373 return -ENOMEM;
3374 }
3375 rcu_read_lock();
3376 old_groupinfo = rcu_dereference(sbi->s_group_info);
3377 if (old_groupinfo)
3378 memcpy(to: new_groupinfo, from: old_groupinfo,
3379 len: sbi->s_group_info_size * sizeof(*sbi->s_group_info));
3380 rcu_read_unlock();
3381 rcu_assign_pointer(sbi->s_group_info, new_groupinfo);
3382 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
3383 if (old_groupinfo)
3384 ext4_kvfree_array_rcu(to_free: old_groupinfo);
3385 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
3386 sbi->s_group_info_size);
3387 return 0;
3388}
3389
3390/* Create and initialize ext4_group_info data for the given group. */
3391int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
3392 struct ext4_group_desc *desc)
3393{
3394 int i;
3395 int metalen = 0;
3396 int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb);
3397 struct ext4_sb_info *sbi = EXT4_SB(sb);
3398 struct ext4_group_info **meta_group_info;
3399 struct kmem_cache *cachep = get_groupinfo_cache(blocksize_bits: sb->s_blocksize_bits);
3400
3401 /*
3402 * First check if this group is the first of a reserved block.
3403 * If it's true, we have to allocate a new table of pointers
3404 * to ext4_group_info structures
3405 */
3406 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3407 metalen = sizeof(*meta_group_info) <<
3408 EXT4_DESC_PER_BLOCK_BITS(sb);
3409 meta_group_info = kmalloc(metalen, GFP_NOFS);
3410 if (meta_group_info == NULL) {
3411 ext4_msg(sb, KERN_ERR, "can't allocate mem "
3412 "for a buddy group");
3413 return -ENOMEM;
3414 }
3415 rcu_read_lock();
3416 rcu_dereference(sbi->s_group_info)[idx] = meta_group_info;
3417 rcu_read_unlock();
3418 }
3419
3420 meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx);
3421 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
3422
3423 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
3424 if (meta_group_info[i] == NULL) {
3425 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
3426 goto exit_group_info;
3427 }
3428 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
3429 addr: &(meta_group_info[i]->bb_state));
3430
3431 /*
3432 * initialize bb_free to be able to skip
3433 * empty groups without initialization
3434 */
3435 if (ext4_has_group_desc_csum(sb) &&
3436 (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3437 meta_group_info[i]->bb_free =
3438 ext4_free_clusters_after_init(sb, block_group: group, gdp: desc);
3439 } else {
3440 meta_group_info[i]->bb_free =
3441 ext4_free_group_clusters(sb, bg: desc);
3442 }
3443
3444 INIT_LIST_HEAD(list: &meta_group_info[i]->bb_prealloc_list);
3445 init_rwsem(&meta_group_info[i]->alloc_sem);
3446 meta_group_info[i]->bb_free_root = RB_ROOT;
3447 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
3448 meta_group_info[i]->bb_avg_fragment_size_order = -1; /* uninit */
3449 meta_group_info[i]->bb_group = group;
3450
3451 mb_group_bb_bitmap_alloc(sb, grp: meta_group_info[i], group);
3452 return 0;
3453
3454exit_group_info:
3455 /* If a meta_group_info table has been allocated, release it now */
3456 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3457 struct ext4_group_info ***group_info;
3458
3459 rcu_read_lock();
3460 group_info = rcu_dereference(sbi->s_group_info);
3461 kfree(objp: group_info[idx]);
3462 group_info[idx] = NULL;
3463 rcu_read_unlock();
3464 }
3465 return -ENOMEM;
3466} /* ext4_mb_add_groupinfo */
3467
3468static int ext4_mb_init_backend(struct super_block *sb)
3469{
3470 ext4_group_t ngroups = ext4_get_groups_count(sb);
3471 ext4_group_t i;
3472 struct ext4_sb_info *sbi = EXT4_SB(sb);
3473 int err;
3474 struct ext4_group_desc *desc;
3475 struct ext4_group_info ***group_info;
3476 struct kmem_cache *cachep;
3477
3478 err = ext4_mb_alloc_groupinfo(sb, ngroups);
3479 if (err)
3480 return err;
3481
3482 sbi->s_buddy_cache = new_inode(sb);
3483 if (sbi->s_buddy_cache == NULL) {
3484 ext4_msg(sb, KERN_ERR, "can't get new inode");
3485 goto err_freesgi;
3486 }
3487 /* To avoid potentially colliding with an valid on-disk inode number,
3488 * use EXT4_BAD_INO for the buddy cache inode number. This inode is
3489 * not in the inode hash, so it should never be found by iget(), but
3490 * this will avoid confusion if it ever shows up during debugging. */
3491 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
3492 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
3493 for (i = 0; i < ngroups; i++) {
3494 cond_resched();
3495 desc = ext4_get_group_desc(sb, block_group: i, NULL);
3496 if (desc == NULL) {
3497 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
3498 goto err_freebuddy;
3499 }
3500 if (ext4_mb_add_groupinfo(sb, group: i, desc) != 0)
3501 goto err_freebuddy;
3502 }
3503
3504 if (ext4_has_feature_flex_bg(sb)) {
3505 /* a single flex group is supposed to be read by a single IO.
3506 * 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is
3507 * unsigned integer, so the maximum shift is 32.
3508 */
3509 if (sbi->s_es->s_log_groups_per_flex >= 32) {
3510 ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group");
3511 goto err_freebuddy;
3512 }
3513 sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex,
3514 BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9));
3515 sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */
3516 } else {
3517 sbi->s_mb_prefetch = 32;
3518 }
3519 if (sbi->s_mb_prefetch > ext4_get_groups_count(sb))
3520 sbi->s_mb_prefetch = ext4_get_groups_count(sb);
3521 /*
3522 * now many real IOs to prefetch within a single allocation at
3523 * CR_POWER2_ALIGNED. Given CR_POWER2_ALIGNED is an CPU-related
3524 * optimization we shouldn't try to load too many groups, at some point
3525 * we should start to use what we've got in memory.
3526 * with an average random access time 5ms, it'd take a second to get
3527 * 200 groups (* N with flex_bg), so let's make this limit 4
3528 */
3529 sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4;
3530 if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb))
3531 sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb);
3532
3533 return 0;
3534
3535err_freebuddy:
3536 cachep = get_groupinfo_cache(blocksize_bits: sb->s_blocksize_bits);
3537 while (i-- > 0) {
3538 struct ext4_group_info *grp = ext4_get_group_info(sb, group: i);
3539
3540 if (grp)
3541 kmem_cache_free(s: cachep, objp: grp);
3542 }
3543 i = sbi->s_group_info_size;
3544 rcu_read_lock();
3545 group_info = rcu_dereference(sbi->s_group_info);
3546 while (i-- > 0)
3547 kfree(objp: group_info[i]);
3548 rcu_read_unlock();
3549 iput(sbi->s_buddy_cache);
3550err_freesgi:
3551 rcu_read_lock();
3552 kvfree(rcu_dereference(sbi->s_group_info));
3553 rcu_read_unlock();
3554 return -ENOMEM;
3555}
3556
3557static void ext4_groupinfo_destroy_slabs(void)
3558{
3559 int i;
3560
3561 for (i = 0; i < NR_GRPINFO_CACHES; i++) {
3562 kmem_cache_destroy(s: ext4_groupinfo_caches[i]);
3563 ext4_groupinfo_caches[i] = NULL;
3564 }
3565}
3566
3567static int ext4_groupinfo_create_slab(size_t size)
3568{
3569 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
3570 int slab_size;
3571 int blocksize_bits = order_base_2(size);
3572 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3573 struct kmem_cache *cachep;
3574
3575 if (cache_index >= NR_GRPINFO_CACHES)
3576 return -EINVAL;
3577
3578 if (unlikely(cache_index < 0))
3579 cache_index = 0;
3580
3581 mutex_lock(lock: &ext4_grpinfo_slab_create_mutex);
3582 if (ext4_groupinfo_caches[cache_index]) {
3583 mutex_unlock(lock: &ext4_grpinfo_slab_create_mutex);
3584 return 0; /* Already created */
3585 }
3586
3587 slab_size = offsetof(struct ext4_group_info,
3588 bb_counters[blocksize_bits + 2]);
3589
3590 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
3591 slab_size, 0, SLAB_RECLAIM_ACCOUNT,
3592 NULL);
3593
3594 ext4_groupinfo_caches[cache_index] = cachep;
3595
3596 mutex_unlock(lock: &ext4_grpinfo_slab_create_mutex);
3597 if (!cachep) {
3598 printk(KERN_EMERG
3599 "EXT4-fs: no memory for groupinfo slab cache\n");
3600 return -ENOMEM;
3601 }
3602
3603 return 0;
3604}
3605
3606static void ext4_discard_work(struct work_struct *work)
3607{
3608 struct ext4_sb_info *sbi = container_of(work,
3609 struct ext4_sb_info, s_discard_work);
3610 struct super_block *sb = sbi->s_sb;
3611 struct ext4_free_data *fd, *nfd;
3612 struct ext4_buddy e4b;
3613 LIST_HEAD(discard_list);
3614 ext4_group_t grp, load_grp;
3615 int err = 0;
3616
3617 spin_lock(lock: &sbi->s_md_lock);
3618 list_splice_init(list: &sbi->s_discard_list, head: &discard_list);
3619 spin_unlock(lock: &sbi->s_md_lock);
3620
3621 load_grp = UINT_MAX;
3622 list_for_each_entry_safe(fd, nfd, &discard_list, efd_list) {
3623 /*
3624 * If filesystem is umounting or no memory or suffering
3625 * from no space, give up the discard
3626 */
3627 if ((sb->s_flags & SB_ACTIVE) && !err &&
3628 !atomic_read(v: &sbi->s_retry_alloc_pending)) {
3629 grp = fd->efd_group;
3630 if (grp != load_grp) {
3631 if (load_grp != UINT_MAX)
3632 ext4_mb_unload_buddy(e4b: &e4b);
3633
3634 err = ext4_mb_load_buddy(sb, group: grp, e4b: &e4b);
3635 if (err) {
3636 kmem_cache_free(s: ext4_free_data_cachep, objp: fd);
3637 load_grp = UINT_MAX;
3638 continue;
3639 } else {
3640 load_grp = grp;
3641 }
3642 }
3643
3644 ext4_lock_group(sb, group: grp);
3645 ext4_try_to_trim_range(sb, e4b: &e4b, start: fd->efd_start_cluster,
3646 max: fd->efd_start_cluster + fd->efd_count - 1, minblocks: 1);
3647 ext4_unlock_group(sb, group: grp);
3648 }
3649 kmem_cache_free(s: ext4_free_data_cachep, objp: fd);
3650 }
3651
3652 if (load_grp != UINT_MAX)
3653 ext4_mb_unload_buddy(e4b: &e4b);
3654}
3655
3656static inline void ext4_mb_avg_fragment_size_destroy(struct ext4_sb_info *sbi)
3657{
3658 if (!sbi->s_mb_avg_fragment_size)
3659 return;
3660
3661 for (int i = 0; i < MB_NUM_ORDERS(sbi->s_sb); i++)
3662 xa_destroy(&sbi->s_mb_avg_fragment_size[i]);
3663
3664 kfree(objp: sbi->s_mb_avg_fragment_size);
3665 sbi->s_mb_avg_fragment_size = NULL;
3666}
3667
3668static inline void ext4_mb_largest_free_orders_destroy(struct ext4_sb_info *sbi)
3669{
3670 if (!sbi->s_mb_largest_free_orders)
3671 return;
3672
3673 for (int i = 0; i < MB_NUM_ORDERS(sbi->s_sb); i++)
3674 xa_destroy(&sbi->s_mb_largest_free_orders[i]);
3675
3676 kfree(objp: sbi->s_mb_largest_free_orders);
3677 sbi->s_mb_largest_free_orders = NULL;
3678}
3679
3680int ext4_mb_init(struct super_block *sb)
3681{
3682 struct ext4_sb_info *sbi = EXT4_SB(sb);
3683 unsigned i, j;
3684 unsigned offset, offset_incr;
3685 unsigned max;
3686 int ret;
3687
3688 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets);
3689
3690 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
3691 if (sbi->s_mb_offsets == NULL) {
3692 ret = -ENOMEM;
3693 goto out;
3694 }
3695
3696 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs);
3697 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
3698 if (sbi->s_mb_maxs == NULL) {
3699 ret = -ENOMEM;
3700 goto out;
3701 }
3702
3703 ret = ext4_groupinfo_create_slab(size: sb->s_blocksize);
3704 if (ret < 0)
3705 goto out;
3706
3707 /* order 0 is regular bitmap */
3708 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
3709 sbi->s_mb_offsets[0] = 0;
3710
3711 i = 1;
3712 offset = 0;
3713 offset_incr = 1 << (sb->s_blocksize_bits - 1);
3714 max = sb->s_blocksize << 2;
3715 do {
3716 sbi->s_mb_offsets[i] = offset;
3717 sbi->s_mb_maxs[i] = max;
3718 offset += offset_incr;
3719 offset_incr = offset_incr >> 1;
3720 max = max >> 1;
3721 i++;
3722 } while (i < MB_NUM_ORDERS(sb));
3723
3724 sbi->s_mb_avg_fragment_size =
3725 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct xarray),
3726 GFP_KERNEL);
3727 if (!sbi->s_mb_avg_fragment_size) {
3728 ret = -ENOMEM;
3729 goto out;
3730 }
3731 for (i = 0; i < MB_NUM_ORDERS(sb); i++)
3732 xa_init(xa: &sbi->s_mb_avg_fragment_size[i]);
3733
3734 sbi->s_mb_largest_free_orders =
3735 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct xarray),
3736 GFP_KERNEL);
3737 if (!sbi->s_mb_largest_free_orders) {
3738 ret = -ENOMEM;
3739 goto out;
3740 }
3741 for (i = 0; i < MB_NUM_ORDERS(sb); i++)
3742 xa_init(xa: &sbi->s_mb_largest_free_orders[i]);
3743
3744 spin_lock_init(&sbi->s_md_lock);
3745 atomic_set(v: &sbi->s_mb_free_pending, i: 0);
3746 INIT_LIST_HEAD(list: &sbi->s_freed_data_list[0]);
3747 INIT_LIST_HEAD(list: &sbi->s_freed_data_list[1]);
3748 INIT_LIST_HEAD(list: &sbi->s_discard_list);
3749 INIT_WORK(&sbi->s_discard_work, ext4_discard_work);
3750 atomic_set(v: &sbi->s_retry_alloc_pending, i: 0);
3751
3752 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
3753 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
3754 sbi->s_mb_stats = MB_DEFAULT_STATS;
3755 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
3756 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
3757 sbi->s_mb_best_avail_max_trim_order = MB_DEFAULT_BEST_AVAIL_TRIM_ORDER;
3758
3759 /*
3760 * The default group preallocation is 512, which for 4k block
3761 * sizes translates to 2 megabytes. However for bigalloc file
3762 * systems, this is probably too big (i.e, if the cluster size
3763 * is 1 megabyte, then group preallocation size becomes half a
3764 * gigabyte!). As a default, we will keep a two megabyte
3765 * group pralloc size for cluster sizes up to 64k, and after
3766 * that, we will force a minimum group preallocation size of
3767 * 32 clusters. This translates to 8 megs when the cluster
3768 * size is 256k, and 32 megs when the cluster size is 1 meg,
3769 * which seems reasonable as a default.
3770 */
3771 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
3772 sbi->s_cluster_bits, 32);
3773 /*
3774 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc
3775 * to the lowest multiple of s_stripe which is bigger than
3776 * the s_mb_group_prealloc as determined above. We want
3777 * the preallocation size to be an exact multiple of the
3778 * RAID stripe size so that preallocations don't fragment
3779 * the stripes.
3780 */
3781 if (sbi->s_stripe > 1) {
3782 sbi->s_mb_group_prealloc = roundup(
3783 sbi->s_mb_group_prealloc, EXT4_NUM_B2C(sbi, sbi->s_stripe));
3784 }
3785
3786 sbi->s_mb_nr_global_goals = umin(num_possible_cpus(),
3787 DIV_ROUND_UP(sbi->s_groups_count, 4));
3788 sbi->s_mb_last_groups = kcalloc(sbi->s_mb_nr_global_goals,
3789 sizeof(ext4_group_t), GFP_KERNEL);
3790 if (sbi->s_mb_last_groups == NULL) {
3791 ret = -ENOMEM;
3792 goto out;
3793 }
3794
3795 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
3796 if (sbi->s_locality_groups == NULL) {
3797 ret = -ENOMEM;
3798 goto out_free_last_groups;
3799 }
3800 for_each_possible_cpu(i) {
3801 struct ext4_locality_group *lg;
3802 lg = per_cpu_ptr(sbi->s_locality_groups, i);
3803 mutex_init(&lg->lg_mutex);
3804 for (j = 0; j < PREALLOC_TB_SIZE; j++)
3805 INIT_LIST_HEAD(list: &lg->lg_prealloc_list[j]);
3806 spin_lock_init(&lg->lg_prealloc_lock);
3807 }
3808
3809 if (bdev_nonrot(bdev: sb->s_bdev))
3810 sbi->s_mb_max_linear_groups = 0;
3811 else
3812 sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT;
3813 /* init file for buddy data */
3814 ret = ext4_mb_init_backend(sb);
3815 if (ret != 0)
3816 goto out_free_locality_groups;
3817
3818 return 0;
3819
3820out_free_locality_groups:
3821 free_percpu(pdata: sbi->s_locality_groups);
3822 sbi->s_locality_groups = NULL;
3823out_free_last_groups:
3824 kfree(objp: sbi->s_mb_last_groups);
3825 sbi->s_mb_last_groups = NULL;
3826out:
3827 ext4_mb_avg_fragment_size_destroy(sbi);
3828 ext4_mb_largest_free_orders_destroy(sbi);
3829 kfree(objp: sbi->s_mb_offsets);
3830 sbi->s_mb_offsets = NULL;
3831 kfree(objp: sbi->s_mb_maxs);
3832 sbi->s_mb_maxs = NULL;
3833 return ret;
3834}
3835
3836/* need to called with the ext4 group lock held */
3837static int ext4_mb_cleanup_pa(struct ext4_group_info *grp)
3838{
3839 struct ext4_prealloc_space *pa;
3840 struct list_head *cur, *tmp;
3841 int count = 0;
3842
3843 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
3844 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3845 list_del(entry: &pa->pa_group_list);
3846 count++;
3847 kmem_cache_free(s: ext4_pspace_cachep, objp: pa);
3848 }
3849 return count;
3850}
3851
3852void ext4_mb_release(struct super_block *sb)
3853{
3854 ext4_group_t ngroups = ext4_get_groups_count(sb);
3855 ext4_group_t i;
3856 int num_meta_group_infos;
3857 struct ext4_group_info *grinfo, ***group_info;
3858 struct ext4_sb_info *sbi = EXT4_SB(sb);
3859 struct kmem_cache *cachep = get_groupinfo_cache(blocksize_bits: sb->s_blocksize_bits);
3860 int count;
3861
3862 if (test_opt(sb, DISCARD)) {
3863 /*
3864 * wait the discard work to drain all of ext4_free_data
3865 */
3866 flush_work(work: &sbi->s_discard_work);
3867 WARN_ON_ONCE(!list_empty(&sbi->s_discard_list));
3868 }
3869
3870 if (sbi->s_group_info) {
3871 for (i = 0; i < ngroups; i++) {
3872 cond_resched();
3873 grinfo = ext4_get_group_info(sb, group: i);
3874 if (!grinfo)
3875 continue;
3876 mb_group_bb_bitmap_free(grp: grinfo);
3877 ext4_lock_group(sb, group: i);
3878 count = ext4_mb_cleanup_pa(grp: grinfo);
3879 if (count)
3880 mb_debug(sb, "mballoc: %d PAs left\n",
3881 count);
3882 ext4_unlock_group(sb, group: i);
3883 kmem_cache_free(s: cachep, objp: grinfo);
3884 }
3885 num_meta_group_infos = (ngroups +
3886 EXT4_DESC_PER_BLOCK(sb) - 1) >>
3887 EXT4_DESC_PER_BLOCK_BITS(sb);
3888 rcu_read_lock();
3889 group_info = rcu_dereference(sbi->s_group_info);
3890 for (i = 0; i < num_meta_group_infos; i++)
3891 kfree(objp: group_info[i]);
3892 kvfree(addr: group_info);
3893 rcu_read_unlock();
3894 }
3895 ext4_mb_avg_fragment_size_destroy(sbi);
3896 ext4_mb_largest_free_orders_destroy(sbi);
3897 kfree(objp: sbi->s_mb_offsets);
3898 kfree(objp: sbi->s_mb_maxs);
3899 iput(sbi->s_buddy_cache);
3900 if (sbi->s_mb_stats) {
3901 ext4_msg(sb, KERN_INFO,
3902 "mballoc: %u blocks %u reqs (%u success)",
3903 atomic_read(&sbi->s_bal_allocated),
3904 atomic_read(&sbi->s_bal_reqs),
3905 atomic_read(&sbi->s_bal_success));
3906 ext4_msg(sb, KERN_INFO,
3907 "mballoc: %u extents scanned, %u groups scanned, %u goal hits, "
3908 "%u 2^N hits, %u breaks, %u lost",
3909 atomic_read(&sbi->s_bal_ex_scanned),
3910 atomic_read(&sbi->s_bal_groups_scanned),
3911 atomic_read(&sbi->s_bal_goals),
3912 atomic_read(&sbi->s_bal_2orders),
3913 atomic_read(&sbi->s_bal_breaks),
3914 atomic_read(&sbi->s_mb_lost_chunks));
3915 ext4_msg(sb, KERN_INFO,
3916 "mballoc: %u generated and it took %llu",
3917 atomic_read(&sbi->s_mb_buddies_generated),
3918 atomic64_read(&sbi->s_mb_generation_time));
3919 ext4_msg(sb, KERN_INFO,
3920 "mballoc: %u preallocated, %u discarded",
3921 atomic_read(&sbi->s_mb_preallocated),
3922 atomic_read(&sbi->s_mb_discarded));
3923 }
3924
3925 free_percpu(pdata: sbi->s_locality_groups);
3926 kfree(objp: sbi->s_mb_last_groups);
3927}
3928
3929static inline int ext4_issue_discard(struct super_block *sb,
3930 ext4_group_t block_group, ext4_grpblk_t cluster, int count)
3931{
3932 ext4_fsblk_t discard_block;
3933
3934 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
3935 ext4_group_first_block_no(sb, group_no: block_group));
3936 count = EXT4_C2B(EXT4_SB(sb), count);
3937 trace_ext4_discard_blocks(sb,
3938 blk: (unsigned long long) discard_block, count);
3939
3940 return sb_issue_discard(sb, block: discard_block, nr_blocks: count, GFP_NOFS, flags: 0);
3941}
3942
3943static void ext4_free_data_in_buddy(struct super_block *sb,
3944 struct ext4_free_data *entry)
3945{
3946 struct ext4_buddy e4b;
3947 struct ext4_group_info *db;
3948 int err, count = 0;
3949
3950 mb_debug(sb, "gonna free %u blocks in group %u (0x%p):",
3951 entry->efd_count, entry->efd_group, entry);
3952
3953 err = ext4_mb_load_buddy(sb, group: entry->efd_group, e4b: &e4b);
3954 /* we expect to find existing buddy because it's pinned */
3955 BUG_ON(err != 0);
3956
3957 atomic_sub(i: entry->efd_count, v: &EXT4_SB(sb)->s_mb_free_pending);
3958 db = e4b.bd_info;
3959 /* there are blocks to put in buddy to make them really free */
3960 count += entry->efd_count;
3961 ext4_lock_group(sb, group: entry->efd_group);
3962 /* Take it out of per group rb tree */
3963 rb_erase(&entry->efd_node, &(db->bb_free_root));
3964 mb_free_blocks(NULL, e4b: &e4b, first: entry->efd_start_cluster, count: entry->efd_count);
3965
3966 /*
3967 * Clear the trimmed flag for the group so that the next
3968 * ext4_trim_fs can trim it.
3969 */
3970 EXT4_MB_GRP_CLEAR_TRIMMED(db);
3971
3972 if (!db->bb_free_root.rb_node) {
3973 /* No more items in the per group rb tree
3974 * balance refcounts from ext4_mb_free_metadata()
3975 */
3976 folio_put(folio: e4b.bd_buddy_folio);
3977 folio_put(folio: e4b.bd_bitmap_folio);
3978 }
3979 ext4_unlock_group(sb, group: entry->efd_group);
3980 ext4_mb_unload_buddy(e4b: &e4b);
3981
3982 mb_debug(sb, "freed %d blocks in 1 structures\n", count);
3983}
3984
3985/*
3986 * This function is called by the jbd2 layer once the commit has finished,
3987 * so we know we can free the blocks that were released with that commit.
3988 */
3989void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
3990{
3991 struct ext4_sb_info *sbi = EXT4_SB(sb);
3992 struct ext4_free_data *entry, *tmp;
3993 LIST_HEAD(freed_data_list);
3994 struct list_head *s_freed_head = &sbi->s_freed_data_list[commit_tid & 1];
3995 bool wake;
3996
3997 list_replace_init(old: s_freed_head, new: &freed_data_list);
3998
3999 list_for_each_entry(entry, &freed_data_list, efd_list)
4000 ext4_free_data_in_buddy(sb, entry);
4001
4002 if (test_opt(sb, DISCARD)) {
4003 spin_lock(lock: &sbi->s_md_lock);
4004 wake = list_empty(head: &sbi->s_discard_list);
4005 list_splice_tail(list: &freed_data_list, head: &sbi->s_discard_list);
4006 spin_unlock(lock: &sbi->s_md_lock);
4007 if (wake)
4008 queue_work(wq: system_dfl_wq, work: &sbi->s_discard_work);
4009 } else {
4010 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
4011 kmem_cache_free(s: ext4_free_data_cachep, objp: entry);
4012 }
4013}
4014
4015int __init ext4_init_mballoc(void)
4016{
4017 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
4018 SLAB_RECLAIM_ACCOUNT);
4019 if (ext4_pspace_cachep == NULL)
4020 goto out;
4021
4022 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
4023 SLAB_RECLAIM_ACCOUNT);
4024 if (ext4_ac_cachep == NULL)
4025 goto out_pa_free;
4026
4027 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
4028 SLAB_RECLAIM_ACCOUNT);
4029 if (ext4_free_data_cachep == NULL)
4030 goto out_ac_free;
4031
4032 return 0;
4033
4034out_ac_free:
4035 kmem_cache_destroy(s: ext4_ac_cachep);
4036out_pa_free:
4037 kmem_cache_destroy(s: ext4_pspace_cachep);
4038out:
4039 return -ENOMEM;
4040}
4041
4042void ext4_exit_mballoc(void)
4043{
4044 /*
4045 * Wait for completion of call_rcu()'s on ext4_pspace_cachep
4046 * before destroying the slab cache.
4047 */
4048 rcu_barrier();
4049 kmem_cache_destroy(s: ext4_pspace_cachep);
4050 kmem_cache_destroy(s: ext4_ac_cachep);
4051 kmem_cache_destroy(s: ext4_free_data_cachep);
4052 ext4_groupinfo_destroy_slabs();
4053}
4054
4055#define EXT4_MB_BITMAP_MARKED_CHECK 0x0001
4056#define EXT4_MB_SYNC_UPDATE 0x0002
4057static int
4058ext4_mb_mark_context(handle_t *handle, struct super_block *sb, bool state,
4059 ext4_group_t group, ext4_grpblk_t blkoff,
4060 ext4_grpblk_t len, int flags, ext4_grpblk_t *ret_changed)
4061{
4062 struct ext4_sb_info *sbi = EXT4_SB(sb);
4063 struct buffer_head *bitmap_bh = NULL;
4064 struct ext4_group_desc *gdp;
4065 struct buffer_head *gdp_bh;
4066 int err;
4067 unsigned int i, already, changed = len;
4068
4069 KUNIT_STATIC_STUB_REDIRECT(ext4_mb_mark_context,
4070 handle, sb, state, group, blkoff, len,
4071 flags, ret_changed);
4072
4073 if (ret_changed)
4074 *ret_changed = 0;
4075 bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
4076 if (IS_ERR(ptr: bitmap_bh))
4077 return PTR_ERR(ptr: bitmap_bh);
4078
4079 if (handle) {
4080 BUFFER_TRACE(bitmap_bh, "getting write access");
4081 err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
4082 EXT4_JTR_NONE);
4083 if (err)
4084 goto out_err;
4085 }
4086
4087 err = -EIO;
4088 gdp = ext4_get_group_desc(sb, block_group: group, bh: &gdp_bh);
4089 if (!gdp)
4090 goto out_err;
4091
4092 if (handle) {
4093 BUFFER_TRACE(gdp_bh, "get_write_access");
4094 err = ext4_journal_get_write_access(handle, sb, gdp_bh,
4095 EXT4_JTR_NONE);
4096 if (err)
4097 goto out_err;
4098 }
4099
4100 ext4_lock_group(sb, group);
4101 if (ext4_has_group_desc_csum(sb) &&
4102 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
4103 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
4104 ext4_free_group_clusters_set(sb, bg: gdp,
4105 count: ext4_free_clusters_after_init(sb, block_group: group, gdp));
4106 }
4107
4108 if (flags & EXT4_MB_BITMAP_MARKED_CHECK) {
4109 already = 0;
4110 for (i = 0; i < len; i++)
4111 if (mb_test_bit(bit: blkoff + i, addr: bitmap_bh->b_data) ==
4112 state)
4113 already++;
4114 changed = len - already;
4115 }
4116
4117 if (state) {
4118 mb_set_bits(bm: bitmap_bh->b_data, cur: blkoff, len);
4119 ext4_free_group_clusters_set(sb, bg: gdp,
4120 count: ext4_free_group_clusters(sb, bg: gdp) - changed);
4121 } else {
4122 mb_clear_bits(bm: bitmap_bh->b_data, cur: blkoff, len);
4123 ext4_free_group_clusters_set(sb, bg: gdp,
4124 count: ext4_free_group_clusters(sb, bg: gdp) + changed);
4125 }
4126
4127 ext4_block_bitmap_csum_set(sb, gdp, bh: bitmap_bh);
4128 ext4_group_desc_csum_set(sb, group, gdp);
4129 ext4_unlock_group(sb, group);
4130 if (ret_changed)
4131 *ret_changed = changed;
4132
4133 if (sbi->s_log_groups_per_flex) {
4134 ext4_group_t flex_group = ext4_flex_group(sbi, block_group: group);
4135 struct flex_groups *fg = sbi_array_rcu_deref(sbi,
4136 s_flex_groups, flex_group);
4137
4138 if (state)
4139 atomic64_sub(i: changed, v: &fg->free_clusters);
4140 else
4141 atomic64_add(i: changed, v: &fg->free_clusters);
4142 }
4143
4144 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
4145 if (err)
4146 goto out_err;
4147 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
4148 if (err)
4149 goto out_err;
4150
4151 if (flags & EXT4_MB_SYNC_UPDATE) {
4152 sync_dirty_buffer(bh: bitmap_bh);
4153 sync_dirty_buffer(bh: gdp_bh);
4154 }
4155
4156out_err:
4157 brelse(bh: bitmap_bh);
4158 return err;
4159}
4160
4161/*
4162 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
4163 * Returns 0 if success or error code
4164 */
4165static noinline_for_stack int
4166ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
4167 handle_t *handle, unsigned int reserv_clstrs)
4168{
4169 struct ext4_group_desc *gdp;
4170 struct ext4_sb_info *sbi;
4171 struct super_block *sb;
4172 ext4_fsblk_t block;
4173 int err, len;
4174 int flags = 0;
4175 ext4_grpblk_t changed;
4176
4177 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
4178 BUG_ON(ac->ac_b_ex.fe_len <= 0);
4179
4180 sb = ac->ac_sb;
4181 sbi = EXT4_SB(sb);
4182
4183 gdp = ext4_get_group_desc(sb, block_group: ac->ac_b_ex.fe_group, NULL);
4184 if (!gdp)
4185 return -EIO;
4186 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
4187 ext4_free_group_clusters(sb, gdp));
4188
4189 block = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
4190 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4191 if (!ext4_inode_block_valid(inode: ac->ac_inode, start_blk: block, count: len)) {
4192 ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
4193 "fs metadata", block, block+len);
4194 /* File system mounted not to panic on error
4195 * Fix the bitmap and return EFSCORRUPTED
4196 * We leak some of the blocks here.
4197 */
4198 err = ext4_mb_mark_context(handle, sb, state: true,
4199 group: ac->ac_b_ex.fe_group,
4200 blkoff: ac->ac_b_ex.fe_start,
4201 len: ac->ac_b_ex.fe_len,
4202 flags: 0, NULL);
4203 if (!err)
4204 err = -EFSCORRUPTED;
4205 return err;
4206 }
4207
4208#ifdef AGGRESSIVE_CHECK
4209 flags |= EXT4_MB_BITMAP_MARKED_CHECK;
4210#endif
4211 err = ext4_mb_mark_context(handle, sb, state: true, group: ac->ac_b_ex.fe_group,
4212 blkoff: ac->ac_b_ex.fe_start, len: ac->ac_b_ex.fe_len,
4213 flags, ret_changed: &changed);
4214
4215 if (err && changed == 0)
4216 return err;
4217
4218#ifdef AGGRESSIVE_CHECK
4219 BUG_ON(changed != ac->ac_b_ex.fe_len);
4220#endif
4221 percpu_counter_sub(fbc: &sbi->s_freeclusters_counter, amount: ac->ac_b_ex.fe_len);
4222 /*
4223 * Now reduce the dirty block count also. Should not go negative
4224 */
4225 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
4226 /* release all the reserved blocks if non delalloc */
4227 percpu_counter_sub(fbc: &sbi->s_dirtyclusters_counter,
4228 amount: reserv_clstrs);
4229
4230 return err;
4231}
4232
4233/*
4234 * Idempotent helper for Ext4 fast commit replay path to set the state of
4235 * blocks in bitmaps and update counters.
4236 */
4237void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
4238 int len, bool state)
4239{
4240 struct ext4_sb_info *sbi = EXT4_SB(sb);
4241 ext4_group_t group;
4242 ext4_grpblk_t blkoff;
4243 int err = 0;
4244 unsigned int clen, thisgrp_len;
4245
4246 while (len > 0) {
4247 ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &group, offsetp: &blkoff);
4248
4249 /*
4250 * Check to see if we are freeing blocks across a group
4251 * boundary.
4252 * In case of flex_bg, this can happen that (block, len) may
4253 * span across more than one group. In that case we need to
4254 * get the corresponding group metadata to work with.
4255 * For this we have goto again loop.
4256 */
4257 thisgrp_len = min_t(unsigned int, (unsigned int)len,
4258 EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
4259 clen = EXT4_NUM_B2C(sbi, thisgrp_len);
4260
4261 if (!ext4_sb_block_valid(sb, NULL, start_blk: block, count: thisgrp_len)) {
4262 ext4_error(sb, "Marking blocks in system zone - "
4263 "Block = %llu, len = %u",
4264 block, thisgrp_len);
4265 break;
4266 }
4267
4268 err = ext4_mb_mark_context(NULL, sb, state,
4269 group, blkoff, len: clen,
4270 EXT4_MB_BITMAP_MARKED_CHECK |
4271 EXT4_MB_SYNC_UPDATE,
4272 NULL);
4273 if (err)
4274 break;
4275
4276 block += thisgrp_len;
4277 len -= thisgrp_len;
4278 BUG_ON(len < 0);
4279 }
4280}
4281
4282/*
4283 * here we normalize request for locality group
4284 * Group request are normalized to s_mb_group_prealloc, which goes to
4285 * s_strip if we set the same via mount option.
4286 * s_mb_group_prealloc can be configured via
4287 * /sys/fs/ext4/<partition>/mb_group_prealloc
4288 *
4289 * XXX: should we try to preallocate more than the group has now?
4290 */
4291static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
4292{
4293 struct super_block *sb = ac->ac_sb;
4294 struct ext4_locality_group *lg = ac->ac_lg;
4295
4296 BUG_ON(lg == NULL);
4297 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
4298 mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len);
4299}
4300
4301/*
4302 * This function returns the next element to look at during inode
4303 * PA rbtree walk. We assume that we have held the inode PA rbtree lock
4304 * (ei->i_prealloc_lock)
4305 *
4306 * new_start The start of the range we want to compare
4307 * cur_start The existing start that we are comparing against
4308 * node The node of the rb_tree
4309 */
4310static inline struct rb_node*
4311ext4_mb_pa_rb_next_iter(ext4_lblk_t new_start, ext4_lblk_t cur_start, struct rb_node *node)
4312{
4313 if (new_start < cur_start)
4314 return node->rb_left;
4315 else
4316 return node->rb_right;
4317}
4318
4319static inline void
4320ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac,
4321 ext4_lblk_t start, loff_t end)
4322{
4323 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4324 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4325 struct ext4_prealloc_space *tmp_pa;
4326 ext4_lblk_t tmp_pa_start;
4327 loff_t tmp_pa_end;
4328 struct rb_node *iter;
4329
4330 read_lock(&ei->i_prealloc_lock);
4331 for (iter = ei->i_prealloc_node.rb_node; iter;
4332 iter = ext4_mb_pa_rb_next_iter(new_start: start, cur_start: tmp_pa_start, node: iter)) {
4333 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4334 pa_node.inode_node);
4335 tmp_pa_start = tmp_pa->pa_lstart;
4336 tmp_pa_end = pa_logical_end(sbi, pa: tmp_pa);
4337
4338 spin_lock(lock: &tmp_pa->pa_lock);
4339 if (tmp_pa->pa_deleted == 0)
4340 BUG_ON(!(start >= tmp_pa_end || end <= tmp_pa_start));
4341 spin_unlock(lock: &tmp_pa->pa_lock);
4342 }
4343 read_unlock(&ei->i_prealloc_lock);
4344}
4345
4346/*
4347 * Given an allocation context "ac" and a range "start", "end", check
4348 * and adjust boundaries if the range overlaps with any of the existing
4349 * preallocatoins stored in the corresponding inode of the allocation context.
4350 *
4351 * Parameters:
4352 * ac allocation context
4353 * start start of the new range
4354 * end end of the new range
4355 */
4356static inline void
4357ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac,
4358 ext4_lblk_t *start, loff_t *end)
4359{
4360 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4361 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4362 struct ext4_prealloc_space *tmp_pa = NULL, *left_pa = NULL, *right_pa = NULL;
4363 struct rb_node *iter;
4364 ext4_lblk_t new_start, tmp_pa_start, right_pa_start = -1;
4365 loff_t new_end, tmp_pa_end, left_pa_end = -1;
4366
4367 new_start = *start;
4368 new_end = *end;
4369
4370 /*
4371 * Adjust the normalized range so that it doesn't overlap with any
4372 * existing preallocated blocks(PAs). Make sure to hold the rbtree lock
4373 * so it doesn't change underneath us.
4374 */
4375 read_lock(&ei->i_prealloc_lock);
4376
4377 /* Step 1: find any one immediate neighboring PA of the normalized range */
4378 for (iter = ei->i_prealloc_node.rb_node; iter;
4379 iter = ext4_mb_pa_rb_next_iter(new_start: ac->ac_o_ex.fe_logical,
4380 cur_start: tmp_pa_start, node: iter)) {
4381 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4382 pa_node.inode_node);
4383 tmp_pa_start = tmp_pa->pa_lstart;
4384 tmp_pa_end = pa_logical_end(sbi, pa: tmp_pa);
4385
4386 /* PA must not overlap original request */
4387 spin_lock(lock: &tmp_pa->pa_lock);
4388 if (tmp_pa->pa_deleted == 0)
4389 BUG_ON(!(ac->ac_o_ex.fe_logical >= tmp_pa_end ||
4390 ac->ac_o_ex.fe_logical < tmp_pa_start));
4391 spin_unlock(lock: &tmp_pa->pa_lock);
4392 }
4393
4394 /*
4395 * Step 2: check if the found PA is left or right neighbor and
4396 * get the other neighbor
4397 */
4398 if (tmp_pa) {
4399 if (tmp_pa->pa_lstart < ac->ac_o_ex.fe_logical) {
4400 struct rb_node *tmp;
4401
4402 left_pa = tmp_pa;
4403 tmp = rb_next(&left_pa->pa_node.inode_node);
4404 if (tmp) {
4405 right_pa = rb_entry(tmp,
4406 struct ext4_prealloc_space,
4407 pa_node.inode_node);
4408 }
4409 } else {
4410 struct rb_node *tmp;
4411
4412 right_pa = tmp_pa;
4413 tmp = rb_prev(&right_pa->pa_node.inode_node);
4414 if (tmp) {
4415 left_pa = rb_entry(tmp,
4416 struct ext4_prealloc_space,
4417 pa_node.inode_node);
4418 }
4419 }
4420 }
4421
4422 /* Step 3: get the non deleted neighbors */
4423 if (left_pa) {
4424 for (iter = &left_pa->pa_node.inode_node;;
4425 iter = rb_prev(iter)) {
4426 if (!iter) {
4427 left_pa = NULL;
4428 break;
4429 }
4430
4431 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4432 pa_node.inode_node);
4433 left_pa = tmp_pa;
4434 spin_lock(lock: &tmp_pa->pa_lock);
4435 if (tmp_pa->pa_deleted == 0) {
4436 spin_unlock(lock: &tmp_pa->pa_lock);
4437 break;
4438 }
4439 spin_unlock(lock: &tmp_pa->pa_lock);
4440 }
4441 }
4442
4443 if (right_pa) {
4444 for (iter = &right_pa->pa_node.inode_node;;
4445 iter = rb_next(iter)) {
4446 if (!iter) {
4447 right_pa = NULL;
4448 break;
4449 }
4450
4451 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4452 pa_node.inode_node);
4453 right_pa = tmp_pa;
4454 spin_lock(lock: &tmp_pa->pa_lock);
4455 if (tmp_pa->pa_deleted == 0) {
4456 spin_unlock(lock: &tmp_pa->pa_lock);
4457 break;
4458 }
4459 spin_unlock(lock: &tmp_pa->pa_lock);
4460 }
4461 }
4462
4463 if (left_pa) {
4464 left_pa_end = pa_logical_end(sbi, pa: left_pa);
4465 BUG_ON(left_pa_end > ac->ac_o_ex.fe_logical);
4466 }
4467
4468 if (right_pa) {
4469 right_pa_start = right_pa->pa_lstart;
4470 BUG_ON(right_pa_start <= ac->ac_o_ex.fe_logical);
4471 }
4472
4473 /* Step 4: trim our normalized range to not overlap with the neighbors */
4474 if (left_pa) {
4475 if (left_pa_end > new_start)
4476 new_start = left_pa_end;
4477 }
4478
4479 if (right_pa) {
4480 if (right_pa_start < new_end)
4481 new_end = right_pa_start;
4482 }
4483 read_unlock(&ei->i_prealloc_lock);
4484
4485 /* XXX: extra loop to check we really don't overlap preallocations */
4486 ext4_mb_pa_assert_overlap(ac, start: new_start, end: new_end);
4487
4488 *start = new_start;
4489 *end = new_end;
4490}
4491
4492/*
4493 * Normalization means making request better in terms of
4494 * size and alignment
4495 */
4496static noinline_for_stack void
4497ext4_mb_normalize_request(struct ext4_allocation_context *ac,
4498 struct ext4_allocation_request *ar)
4499{
4500 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4501 struct ext4_super_block *es = sbi->s_es;
4502 int bsbits, max;
4503 loff_t size, start_off, end;
4504 loff_t orig_size __maybe_unused;
4505 ext4_lblk_t start;
4506
4507 /* do normalize only data requests, metadata requests
4508 do not need preallocation */
4509 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4510 return;
4511
4512 /* sometime caller may want exact blocks */
4513 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4514 return;
4515
4516 /* caller may indicate that preallocation isn't
4517 * required (it's a tail, for example) */
4518 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
4519 return;
4520
4521 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
4522 ext4_mb_normalize_group_request(ac);
4523 return ;
4524 }
4525
4526 bsbits = ac->ac_sb->s_blocksize_bits;
4527
4528 /* first, let's learn actual file size
4529 * given current request is allocated */
4530 size = extent_logical_end(sbi, fex: &ac->ac_o_ex);
4531 size = size << bsbits;
4532 if (size < i_size_read(inode: ac->ac_inode))
4533 size = i_size_read(inode: ac->ac_inode);
4534 orig_size = size;
4535
4536 /* max size of free chunks */
4537 max = 2 << bsbits;
4538
4539#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
4540 (req <= (size) || max <= (chunk_size))
4541
4542 /* first, try to predict filesize */
4543 /* XXX: should this table be tunable? */
4544 start_off = 0;
4545 if (size <= 16 * 1024) {
4546 size = 16 * 1024;
4547 } else if (size <= 32 * 1024) {
4548 size = 32 * 1024;
4549 } else if (size <= 64 * 1024) {
4550 size = 64 * 1024;
4551 } else if (size <= 128 * 1024) {
4552 size = 128 * 1024;
4553 } else if (size <= 256 * 1024) {
4554 size = 256 * 1024;
4555 } else if (size <= 512 * 1024) {
4556 size = 512 * 1024;
4557 } else if (size <= 1024 * 1024) {
4558 size = 1024 * 1024;
4559 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
4560 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4561 (21 - bsbits)) << 21;
4562 size = 2 * 1024 * 1024;
4563 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
4564 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4565 (22 - bsbits)) << 22;
4566 size = 4 * 1024 * 1024;
4567 } else if (NRL_CHECK_SIZE(EXT4_C2B(sbi, ac->ac_o_ex.fe_len),
4568 (8<<20)>>bsbits, max, 8 * 1024)) {
4569 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4570 (23 - bsbits)) << 23;
4571 size = 8 * 1024 * 1024;
4572 } else {
4573 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
4574 size = (loff_t) EXT4_C2B(sbi,
4575 ac->ac_o_ex.fe_len) << bsbits;
4576 }
4577 size = size >> bsbits;
4578 start = start_off >> bsbits;
4579
4580 /*
4581 * For tiny groups (smaller than 8MB) the chosen allocation
4582 * alignment may be larger than group size. Make sure the
4583 * alignment does not move allocation to a different group which
4584 * makes mballoc fail assertions later.
4585 */
4586 start = max(start, rounddown(ac->ac_o_ex.fe_logical,
4587 (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
4588
4589 /* avoid unnecessary preallocation that may trigger assertions */
4590 if (start + size > EXT_MAX_BLOCKS)
4591 size = EXT_MAX_BLOCKS - start;
4592
4593 /* don't cover already allocated blocks in selected range */
4594 if (ar->pleft && start <= ar->lleft) {
4595 size -= ar->lleft + 1 - start;
4596 start = ar->lleft + 1;
4597 }
4598 if (ar->pright && start + size - 1 >= ar->lright)
4599 size -= start + size - ar->lright;
4600
4601 /*
4602 * Trim allocation request for filesystems with artificially small
4603 * groups.
4604 */
4605 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
4606 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
4607
4608 end = start + size;
4609
4610 ext4_mb_pa_adjust_overlap(ac, start: &start, end: &end);
4611
4612 size = end - start;
4613
4614 /*
4615 * In this function "start" and "size" are normalized for better
4616 * alignment and length such that we could preallocate more blocks.
4617 * This normalization is done such that original request of
4618 * ac->ac_o_ex.fe_logical & fe_len should always lie within "start" and
4619 * "size" boundaries.
4620 * (Note fe_len can be relaxed since FS block allocation API does not
4621 * provide gurantee on number of contiguous blocks allocation since that
4622 * depends upon free space left, etc).
4623 * In case of inode pa, later we use the allocated blocks
4624 * [pa_pstart + fe_logical - pa_lstart, fe_len/size] from the preallocated
4625 * range of goal/best blocks [start, size] to put it at the
4626 * ac_o_ex.fe_logical extent of this inode.
4627 * (See ext4_mb_use_inode_pa() for more details)
4628 */
4629 if (start + size <= ac->ac_o_ex.fe_logical ||
4630 start > ac->ac_o_ex.fe_logical) {
4631 ext4_msg(ac->ac_sb, KERN_ERR,
4632 "start %lu, size %lu, fe_logical %lu",
4633 (unsigned long) start, (unsigned long) size,
4634 (unsigned long) ac->ac_o_ex.fe_logical);
4635 BUG();
4636 }
4637 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
4638
4639 /* now prepare goal request */
4640
4641 /* XXX: is it better to align blocks WRT to logical
4642 * placement or satisfy big request as is */
4643 ac->ac_g_ex.fe_logical = start;
4644 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
4645 ac->ac_orig_goal_len = ac->ac_g_ex.fe_len;
4646
4647 /* define goal start in order to merge */
4648 if (ar->pright && (ar->lright == (start + size)) &&
4649 ar->pright >= size &&
4650 ar->pright - size >= le32_to_cpu(es->s_first_data_block)) {
4651 /* merge to the right */
4652 ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: ar->pright - size,
4653 blockgrpp: &ac->ac_g_ex.fe_group,
4654 offsetp: &ac->ac_g_ex.fe_start);
4655 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4656 }
4657 if (ar->pleft && (ar->lleft + 1 == start) &&
4658 ar->pleft + 1 < ext4_blocks_count(es)) {
4659 /* merge to the left */
4660 ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: ar->pleft + 1,
4661 blockgrpp: &ac->ac_g_ex.fe_group,
4662 offsetp: &ac->ac_g_ex.fe_start);
4663 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4664 }
4665
4666 mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size,
4667 orig_size, start);
4668}
4669
4670static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
4671{
4672 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4673
4674 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) {
4675 atomic_inc(v: &sbi->s_bal_reqs);
4676 atomic_add(i: ac->ac_b_ex.fe_len, v: &sbi->s_bal_allocated);
4677 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
4678 atomic_inc(v: &sbi->s_bal_success);
4679
4680 atomic_add(i: ac->ac_found, v: &sbi->s_bal_ex_scanned);
4681 for (int i=0; i<EXT4_MB_NUM_CRS; i++) {
4682 atomic_add(i: ac->ac_cX_found[i], v: &sbi->s_bal_cX_ex_scanned[i]);
4683 }
4684
4685 atomic_add(i: ac->ac_groups_scanned, v: &sbi->s_bal_groups_scanned);
4686 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
4687 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
4688 atomic_inc(v: &sbi->s_bal_goals);
4689 /* did we allocate as much as normalizer originally wanted? */
4690 if (ac->ac_f_ex.fe_len == ac->ac_orig_goal_len)
4691 atomic_inc(v: &sbi->s_bal_len_goals);
4692
4693 if (ac->ac_found > sbi->s_mb_max_to_scan)
4694 atomic_inc(v: &sbi->s_bal_breaks);
4695 }
4696
4697 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
4698 trace_ext4_mballoc_alloc(ac);
4699 else
4700 trace_ext4_mballoc_prealloc(ac);
4701}
4702
4703/*
4704 * Called on failure; free up any blocks from the inode PA for this
4705 * context. We don't need this for MB_GROUP_PA because we only change
4706 * pa_free in ext4_mb_release_context(), but on failure, we've already
4707 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
4708 */
4709static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
4710{
4711 struct ext4_prealloc_space *pa = ac->ac_pa;
4712 struct ext4_buddy e4b;
4713 int err;
4714
4715 if (pa == NULL) {
4716 if (ac->ac_f_ex.fe_len == 0)
4717 return;
4718 err = ext4_mb_load_buddy(sb: ac->ac_sb, group: ac->ac_f_ex.fe_group, e4b: &e4b);
4719 if (WARN_RATELIMIT(err,
4720 "ext4: mb_load_buddy failed (%d)", err))
4721 /*
4722 * This should never happen since we pin the
4723 * pages in the ext4_allocation_context so
4724 * ext4_mb_load_buddy() should never fail.
4725 */
4726 return;
4727 ext4_lock_group(sb: ac->ac_sb, group: ac->ac_f_ex.fe_group);
4728 mb_free_blocks(inode: ac->ac_inode, e4b: &e4b, first: ac->ac_f_ex.fe_start,
4729 count: ac->ac_f_ex.fe_len);
4730 ext4_unlock_group(sb: ac->ac_sb, group: ac->ac_f_ex.fe_group);
4731 ext4_mb_unload_buddy(e4b: &e4b);
4732 return;
4733 }
4734 if (pa->pa_type == MB_INODE_PA) {
4735 spin_lock(lock: &pa->pa_lock);
4736 pa->pa_free += ac->ac_b_ex.fe_len;
4737 spin_unlock(lock: &pa->pa_lock);
4738 }
4739}
4740
4741/*
4742 * use blocks preallocated to inode
4743 */
4744static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
4745 struct ext4_prealloc_space *pa)
4746{
4747 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4748 ext4_fsblk_t start;
4749 ext4_fsblk_t end;
4750 int len;
4751
4752 /* found preallocated blocks, use them */
4753 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
4754 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
4755 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
4756 len = EXT4_NUM_B2C(sbi, end - start);
4757 ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: start, blockgrpp: &ac->ac_b_ex.fe_group,
4758 offsetp: &ac->ac_b_ex.fe_start);
4759 ac->ac_b_ex.fe_len = len;
4760 ac->ac_status = AC_STATUS_FOUND;
4761 ac->ac_pa = pa;
4762
4763 BUG_ON(start < pa->pa_pstart);
4764 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
4765 BUG_ON(pa->pa_free < len);
4766 BUG_ON(ac->ac_b_ex.fe_len <= 0);
4767 pa->pa_free -= len;
4768
4769 mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa);
4770}
4771
4772/*
4773 * use blocks preallocated to locality group
4774 */
4775static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
4776 struct ext4_prealloc_space *pa)
4777{
4778 unsigned int len = ac->ac_o_ex.fe_len;
4779
4780 ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: pa->pa_pstart,
4781 blockgrpp: &ac->ac_b_ex.fe_group,
4782 offsetp: &ac->ac_b_ex.fe_start);
4783 ac->ac_b_ex.fe_len = len;
4784 ac->ac_status = AC_STATUS_FOUND;
4785 ac->ac_pa = pa;
4786
4787 /* we don't correct pa_pstart or pa_len here to avoid
4788 * possible race when the group is being loaded concurrently
4789 * instead we correct pa later, after blocks are marked
4790 * in on-disk bitmap -- see ext4_mb_release_context()
4791 * Other CPUs are prevented from allocating from this pa by lg_mutex
4792 */
4793 mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n",
4794 pa->pa_lstart, len, pa);
4795}
4796
4797/*
4798 * Return the prealloc space that have minimal distance
4799 * from the goal block. @cpa is the prealloc
4800 * space that is having currently known minimal distance
4801 * from the goal block.
4802 */
4803static struct ext4_prealloc_space *
4804ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
4805 struct ext4_prealloc_space *pa,
4806 struct ext4_prealloc_space *cpa)
4807{
4808 ext4_fsblk_t cur_distance, new_distance;
4809
4810 if (cpa == NULL) {
4811 atomic_inc(v: &pa->pa_count);
4812 return pa;
4813 }
4814 cur_distance = abs(goal_block - cpa->pa_pstart);
4815 new_distance = abs(goal_block - pa->pa_pstart);
4816
4817 if (cur_distance <= new_distance)
4818 return cpa;
4819
4820 /* drop the previous reference */
4821 atomic_dec(v: &cpa->pa_count);
4822 atomic_inc(v: &pa->pa_count);
4823 return pa;
4824}
4825
4826/*
4827 * check if found pa meets EXT4_MB_HINT_GOAL_ONLY
4828 */
4829static bool
4830ext4_mb_pa_goal_check(struct ext4_allocation_context *ac,
4831 struct ext4_prealloc_space *pa)
4832{
4833 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4834 ext4_fsblk_t start;
4835
4836 if (likely(!(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)))
4837 return true;
4838
4839 /*
4840 * If EXT4_MB_HINT_GOAL_ONLY is set, ac_g_ex will not be adjusted
4841 * in ext4_mb_normalize_request and will keep same with ac_o_ex
4842 * from ext4_mb_initialize_context. Choose ac_g_ex here to keep
4843 * consistent with ext4_mb_find_by_goal.
4844 */
4845 start = pa->pa_pstart +
4846 (ac->ac_g_ex.fe_logical - pa->pa_lstart);
4847 if (ext4_grp_offs_to_block(sb: ac->ac_sb, fex: &ac->ac_g_ex) != start)
4848 return false;
4849
4850 if (ac->ac_g_ex.fe_len > pa->pa_len -
4851 EXT4_B2C(sbi, ac->ac_g_ex.fe_logical - pa->pa_lstart))
4852 return false;
4853
4854 return true;
4855}
4856
4857/*
4858 * search goal blocks in preallocated space
4859 */
4860static noinline_for_stack bool
4861ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
4862{
4863 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4864 int order, i;
4865 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4866 struct ext4_locality_group *lg;
4867 struct ext4_prealloc_space *tmp_pa = NULL, *cpa = NULL;
4868 struct rb_node *iter;
4869 ext4_fsblk_t goal_block;
4870
4871 /* only data can be preallocated */
4872 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4873 return false;
4874
4875 /*
4876 * first, try per-file preallocation by searching the inode pa rbtree.
4877 *
4878 * Here, we can't do a direct traversal of the tree because
4879 * ext4_mb_discard_group_preallocation() can paralelly mark the pa
4880 * deleted and that can cause direct traversal to skip some entries.
4881 */
4882 read_lock(&ei->i_prealloc_lock);
4883
4884 if (RB_EMPTY_ROOT(&ei->i_prealloc_node)) {
4885 goto try_group_pa;
4886 }
4887
4888 /*
4889 * Step 1: Find a pa with logical start immediately adjacent to the
4890 * original logical start. This could be on the left or right.
4891 *
4892 * (tmp_pa->pa_lstart never changes so we can skip locking for it).
4893 */
4894 for (iter = ei->i_prealloc_node.rb_node; iter;
4895 iter = ext4_mb_pa_rb_next_iter(new_start: ac->ac_o_ex.fe_logical,
4896 cur_start: tmp_pa->pa_lstart, node: iter)) {
4897 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4898 pa_node.inode_node);
4899 }
4900
4901 /*
4902 * Step 2: The adjacent pa might be to the right of logical start, find
4903 * the left adjacent pa. After this step we'd have a valid tmp_pa whose
4904 * logical start is towards the left of original request's logical start
4905 */
4906 if (tmp_pa->pa_lstart > ac->ac_o_ex.fe_logical) {
4907 struct rb_node *tmp;
4908 tmp = rb_prev(&tmp_pa->pa_node.inode_node);
4909
4910 if (tmp) {
4911 tmp_pa = rb_entry(tmp, struct ext4_prealloc_space,
4912 pa_node.inode_node);
4913 } else {
4914 /*
4915 * If there is no adjacent pa to the left then finding
4916 * an overlapping pa is not possible hence stop searching
4917 * inode pa tree
4918 */
4919 goto try_group_pa;
4920 }
4921 }
4922
4923 BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical));
4924
4925 /*
4926 * Step 3: If the left adjacent pa is deleted, keep moving left to find
4927 * the first non deleted adjacent pa. After this step we should have a
4928 * valid tmp_pa which is guaranteed to be non deleted.
4929 */
4930 for (iter = &tmp_pa->pa_node.inode_node;; iter = rb_prev(iter)) {
4931 if (!iter) {
4932 /*
4933 * no non deleted left adjacent pa, so stop searching
4934 * inode pa tree
4935 */
4936 goto try_group_pa;
4937 }
4938 tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4939 pa_node.inode_node);
4940 spin_lock(lock: &tmp_pa->pa_lock);
4941 if (tmp_pa->pa_deleted == 0) {
4942 /*
4943 * We will keep holding the pa_lock from
4944 * this point on because we don't want group discard
4945 * to delete this pa underneath us. Since group
4946 * discard is anyways an ENOSPC operation it
4947 * should be okay for it to wait a few more cycles.
4948 */
4949 break;
4950 } else {
4951 spin_unlock(lock: &tmp_pa->pa_lock);
4952 }
4953 }
4954
4955 BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical));
4956 BUG_ON(tmp_pa->pa_deleted == 1);
4957
4958 /*
4959 * Step 4: We now have the non deleted left adjacent pa. Only this
4960 * pa can possibly satisfy the request hence check if it overlaps
4961 * original logical start and stop searching if it doesn't.
4962 */
4963 if (ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, pa: tmp_pa)) {
4964 spin_unlock(lock: &tmp_pa->pa_lock);
4965 goto try_group_pa;
4966 }
4967
4968 /* non-extent files can't have physical blocks past 2^32 */
4969 if (!(ext4_test_inode_flag(inode: ac->ac_inode, bit: EXT4_INODE_EXTENTS)) &&
4970 (tmp_pa->pa_pstart + EXT4_C2B(sbi, tmp_pa->pa_len) >
4971 EXT4_MAX_BLOCK_FILE_PHYS)) {
4972 /*
4973 * Since PAs don't overlap, we won't find any other PA to
4974 * satisfy this.
4975 */
4976 spin_unlock(lock: &tmp_pa->pa_lock);
4977 goto try_group_pa;
4978 }
4979
4980 if (tmp_pa->pa_free && likely(ext4_mb_pa_goal_check(ac, tmp_pa))) {
4981 atomic_inc(v: &tmp_pa->pa_count);
4982 ext4_mb_use_inode_pa(ac, pa: tmp_pa);
4983 spin_unlock(lock: &tmp_pa->pa_lock);
4984 read_unlock(&ei->i_prealloc_lock);
4985 return true;
4986 } else {
4987 /*
4988 * We found a valid overlapping pa but couldn't use it because
4989 * it had no free blocks. This should ideally never happen
4990 * because:
4991 *
4992 * 1. When a new inode pa is added to rbtree it must have
4993 * pa_free > 0 since otherwise we won't actually need
4994 * preallocation.
4995 *
4996 * 2. An inode pa that is in the rbtree can only have it's
4997 * pa_free become zero when another thread calls:
4998 * ext4_mb_new_blocks
4999 * ext4_mb_use_preallocated
5000 * ext4_mb_use_inode_pa
5001 *
5002 * 3. Further, after the above calls make pa_free == 0, we will
5003 * immediately remove it from the rbtree in:
5004 * ext4_mb_new_blocks
5005 * ext4_mb_release_context
5006 * ext4_mb_put_pa
5007 *
5008 * 4. Since the pa_free becoming 0 and pa_free getting removed
5009 * from tree both happen in ext4_mb_new_blocks, which is always
5010 * called with i_data_sem held for data allocations, we can be
5011 * sure that another process will never see a pa in rbtree with
5012 * pa_free == 0.
5013 */
5014 WARN_ON_ONCE(tmp_pa->pa_free == 0);
5015 }
5016 spin_unlock(lock: &tmp_pa->pa_lock);
5017try_group_pa:
5018 read_unlock(&ei->i_prealloc_lock);
5019
5020 /* can we use group allocation? */
5021 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
5022 return false;
5023
5024 /* inode may have no locality group for some reason */
5025 lg = ac->ac_lg;
5026 if (lg == NULL)
5027 return false;
5028 order = fls(x: ac->ac_o_ex.fe_len) - 1;
5029 if (order > PREALLOC_TB_SIZE - 1)
5030 /* The max size of hash table is PREALLOC_TB_SIZE */
5031 order = PREALLOC_TB_SIZE - 1;
5032
5033 goal_block = ext4_grp_offs_to_block(sb: ac->ac_sb, fex: &ac->ac_g_ex);
5034 /*
5035 * search for the prealloc space that is having
5036 * minimal distance from the goal block.
5037 */
5038 for (i = order; i < PREALLOC_TB_SIZE; i++) {
5039 rcu_read_lock();
5040 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[i],
5041 pa_node.lg_list) {
5042 spin_lock(lock: &tmp_pa->pa_lock);
5043 if (tmp_pa->pa_deleted == 0 &&
5044 tmp_pa->pa_free >= ac->ac_o_ex.fe_len) {
5045
5046 cpa = ext4_mb_check_group_pa(goal_block,
5047 pa: tmp_pa, cpa);
5048 }
5049 spin_unlock(lock: &tmp_pa->pa_lock);
5050 }
5051 rcu_read_unlock();
5052 }
5053 if (cpa) {
5054 ext4_mb_use_group_pa(ac, pa: cpa);
5055 return true;
5056 }
5057 return false;
5058}
5059
5060/*
5061 * the function goes through all preallocation in this group and marks them
5062 * used in in-core bitmap. buddy must be generated from this bitmap
5063 * Need to be called with ext4 group lock held
5064 */
5065static noinline_for_stack
5066void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
5067 ext4_group_t group)
5068{
5069 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
5070 struct ext4_prealloc_space *pa;
5071 struct list_head *cur;
5072 ext4_group_t groupnr;
5073 ext4_grpblk_t start;
5074 int preallocated = 0;
5075 int len;
5076
5077 if (!grp)
5078 return;
5079
5080 /* all form of preallocation discards first load group,
5081 * so the only competing code is preallocation use.
5082 * we don't need any locking here
5083 * notice we do NOT ignore preallocations with pa_deleted
5084 * otherwise we could leave used blocks available for
5085 * allocation in buddy when concurrent ext4_mb_put_pa()
5086 * is dropping preallocation
5087 */
5088 list_for_each(cur, &grp->bb_prealloc_list) {
5089 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
5090 spin_lock(lock: &pa->pa_lock);
5091 ext4_get_group_no_and_offset(sb, blocknr: pa->pa_pstart,
5092 blockgrpp: &groupnr, offsetp: &start);
5093 len = pa->pa_len;
5094 spin_unlock(lock: &pa->pa_lock);
5095 if (unlikely(len == 0))
5096 continue;
5097 BUG_ON(groupnr != group);
5098 mb_set_bits(bm: bitmap, cur: start, len);
5099 preallocated += len;
5100 }
5101 mb_debug(sb, "preallocated %d for group %u\n", preallocated, group);
5102}
5103
5104static void ext4_mb_mark_pa_deleted(struct super_block *sb,
5105 struct ext4_prealloc_space *pa)
5106{
5107 struct ext4_inode_info *ei;
5108
5109 if (pa->pa_deleted) {
5110 ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n",
5111 pa->pa_type, pa->pa_pstart, pa->pa_lstart,
5112 pa->pa_len);
5113 return;
5114 }
5115
5116 pa->pa_deleted = 1;
5117
5118 if (pa->pa_type == MB_INODE_PA) {
5119 ei = EXT4_I(pa->pa_inode);
5120 atomic_dec(v: &ei->i_prealloc_active);
5121 }
5122}
5123
5124static inline void ext4_mb_pa_free(struct ext4_prealloc_space *pa)
5125{
5126 BUG_ON(!pa);
5127 BUG_ON(atomic_read(&pa->pa_count));
5128 BUG_ON(pa->pa_deleted == 0);
5129 kmem_cache_free(s: ext4_pspace_cachep, objp: pa);
5130}
5131
5132static void ext4_mb_pa_callback(struct rcu_head *head)
5133{
5134 struct ext4_prealloc_space *pa;
5135
5136 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
5137 ext4_mb_pa_free(pa);
5138}
5139
5140/*
5141 * drops a reference to preallocated space descriptor
5142 * if this was the last reference and the space is consumed
5143 */
5144static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
5145 struct super_block *sb, struct ext4_prealloc_space *pa)
5146{
5147 ext4_group_t grp;
5148 ext4_fsblk_t grp_blk;
5149 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
5150
5151 /* in this short window concurrent discard can set pa_deleted */
5152 spin_lock(lock: &pa->pa_lock);
5153 if (!atomic_dec_and_test(v: &pa->pa_count) || pa->pa_free != 0) {
5154 spin_unlock(lock: &pa->pa_lock);
5155 return;
5156 }
5157
5158 if (pa->pa_deleted == 1) {
5159 spin_unlock(lock: &pa->pa_lock);
5160 return;
5161 }
5162
5163 ext4_mb_mark_pa_deleted(sb, pa);
5164 spin_unlock(lock: &pa->pa_lock);
5165
5166 grp_blk = pa->pa_pstart;
5167 /*
5168 * If doing group-based preallocation, pa_pstart may be in the
5169 * next group when pa is used up
5170 */
5171 if (pa->pa_type == MB_GROUP_PA)
5172 grp_blk--;
5173
5174 grp = ext4_get_group_number(sb, block: grp_blk);
5175
5176 /*
5177 * possible race:
5178 *
5179 * P1 (buddy init) P2 (regular allocation)
5180 * find block B in PA
5181 * copy on-disk bitmap to buddy
5182 * mark B in on-disk bitmap
5183 * drop PA from group
5184 * mark all PAs in buddy
5185 *
5186 * thus, P1 initializes buddy with B available. to prevent this
5187 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
5188 * against that pair
5189 */
5190 ext4_lock_group(sb, group: grp);
5191 list_del(entry: &pa->pa_group_list);
5192 ext4_unlock_group(sb, group: grp);
5193
5194 if (pa->pa_type == MB_INODE_PA) {
5195 write_lock(pa->pa_node_lock.inode_lock);
5196 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5197 write_unlock(pa->pa_node_lock.inode_lock);
5198 ext4_mb_pa_free(pa);
5199 } else {
5200 spin_lock(lock: pa->pa_node_lock.lg_lock);
5201 list_del_rcu(entry: &pa->pa_node.lg_list);
5202 spin_unlock(lock: pa->pa_node_lock.lg_lock);
5203 call_rcu(head: &(pa)->u.pa_rcu, func: ext4_mb_pa_callback);
5204 }
5205}
5206
5207static void ext4_mb_pa_rb_insert(struct rb_root *root, struct rb_node *new)
5208{
5209 struct rb_node **iter = &root->rb_node, *parent = NULL;
5210 struct ext4_prealloc_space *iter_pa, *new_pa;
5211 ext4_lblk_t iter_start, new_start;
5212
5213 while (*iter) {
5214 iter_pa = rb_entry(*iter, struct ext4_prealloc_space,
5215 pa_node.inode_node);
5216 new_pa = rb_entry(new, struct ext4_prealloc_space,
5217 pa_node.inode_node);
5218 iter_start = iter_pa->pa_lstart;
5219 new_start = new_pa->pa_lstart;
5220
5221 parent = *iter;
5222 if (new_start < iter_start)
5223 iter = &((*iter)->rb_left);
5224 else
5225 iter = &((*iter)->rb_right);
5226 }
5227
5228 rb_link_node(node: new, parent, rb_link: iter);
5229 rb_insert_color(new, root);
5230}
5231
5232/*
5233 * creates new preallocated space for given inode
5234 */
5235static noinline_for_stack void
5236ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
5237{
5238 struct super_block *sb = ac->ac_sb;
5239 struct ext4_sb_info *sbi = EXT4_SB(sb);
5240 struct ext4_prealloc_space *pa;
5241 struct ext4_group_info *grp;
5242 struct ext4_inode_info *ei;
5243
5244 /* preallocate only when found space is larger then requested */
5245 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
5246 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
5247 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
5248 BUG_ON(ac->ac_pa == NULL);
5249
5250 pa = ac->ac_pa;
5251
5252 if (ac->ac_b_ex.fe_len < ac->ac_orig_goal_len) {
5253 struct ext4_free_extent ex = {
5254 .fe_logical = ac->ac_g_ex.fe_logical,
5255 .fe_len = ac->ac_orig_goal_len,
5256 };
5257 loff_t orig_goal_end = extent_logical_end(sbi, fex: &ex);
5258 loff_t o_ex_end = extent_logical_end(sbi, fex: &ac->ac_o_ex);
5259
5260 /*
5261 * We can't allocate as much as normalizer wants, so we try
5262 * to get proper lstart to cover the original request, except
5263 * when the goal doesn't cover the original request as below:
5264 *
5265 * orig_ex:2045/2055(10), isize:8417280 -> normalized:0/2048
5266 * best_ex:0/200(200) -> adjusted: 1848/2048(200)
5267 */
5268 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
5269 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
5270
5271 /*
5272 * Use the below logic for adjusting best extent as it keeps
5273 * fragmentation in check while ensuring logical range of best
5274 * extent doesn't overflow out of goal extent:
5275 *
5276 * 1. Check if best ex can be kept at end of goal (before
5277 * cr_best_avail trimmed it) and still cover original start
5278 * 2. Else, check if best ex can be kept at start of goal and
5279 * still cover original end
5280 * 3. Else, keep the best ex at start of original request.
5281 */
5282 ex.fe_len = ac->ac_b_ex.fe_len;
5283
5284 ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len);
5285 if (ac->ac_o_ex.fe_logical >= ex.fe_logical)
5286 goto adjust_bex;
5287
5288 ex.fe_logical = ac->ac_g_ex.fe_logical;
5289 if (o_ex_end <= extent_logical_end(sbi, fex: &ex))
5290 goto adjust_bex;
5291
5292 ex.fe_logical = ac->ac_o_ex.fe_logical;
5293adjust_bex:
5294 ac->ac_b_ex.fe_logical = ex.fe_logical;
5295
5296 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
5297 BUG_ON(extent_logical_end(sbi, &ex) > orig_goal_end);
5298 }
5299
5300 pa->pa_lstart = ac->ac_b_ex.fe_logical;
5301 pa->pa_pstart = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
5302 pa->pa_len = ac->ac_b_ex.fe_len;
5303 pa->pa_free = pa->pa_len;
5304 spin_lock_init(&pa->pa_lock);
5305 INIT_LIST_HEAD(list: &pa->pa_group_list);
5306 pa->pa_deleted = 0;
5307 pa->pa_type = MB_INODE_PA;
5308
5309 mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
5310 pa->pa_len, pa->pa_lstart);
5311 trace_ext4_mb_new_inode_pa(ac, pa);
5312
5313 atomic_add(i: pa->pa_free, v: &sbi->s_mb_preallocated);
5314 ext4_mb_use_inode_pa(ac, pa);
5315
5316 ei = EXT4_I(ac->ac_inode);
5317 grp = ext4_get_group_info(sb, group: ac->ac_b_ex.fe_group);
5318 if (!grp)
5319 return;
5320
5321 pa->pa_node_lock.inode_lock = &ei->i_prealloc_lock;
5322 pa->pa_inode = ac->ac_inode;
5323
5324 list_add(new: &pa->pa_group_list, head: &grp->bb_prealloc_list);
5325
5326 write_lock(pa->pa_node_lock.inode_lock);
5327 ext4_mb_pa_rb_insert(root: &ei->i_prealloc_node, new: &pa->pa_node.inode_node);
5328 write_unlock(pa->pa_node_lock.inode_lock);
5329 atomic_inc(v: &ei->i_prealloc_active);
5330}
5331
5332/*
5333 * creates new preallocated space for locality group inodes belongs to
5334 */
5335static noinline_for_stack void
5336ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
5337{
5338 struct super_block *sb = ac->ac_sb;
5339 struct ext4_locality_group *lg;
5340 struct ext4_prealloc_space *pa;
5341 struct ext4_group_info *grp;
5342
5343 /* preallocate only when found space is larger then requested */
5344 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
5345 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
5346 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
5347 BUG_ON(ac->ac_pa == NULL);
5348
5349 pa = ac->ac_pa;
5350
5351 pa->pa_pstart = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
5352 pa->pa_lstart = pa->pa_pstart;
5353 pa->pa_len = ac->ac_b_ex.fe_len;
5354 pa->pa_free = pa->pa_len;
5355 spin_lock_init(&pa->pa_lock);
5356 INIT_LIST_HEAD(list: &pa->pa_node.lg_list);
5357 INIT_LIST_HEAD(list: &pa->pa_group_list);
5358 pa->pa_deleted = 0;
5359 pa->pa_type = MB_GROUP_PA;
5360
5361 mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
5362 pa->pa_len, pa->pa_lstart);
5363 trace_ext4_mb_new_group_pa(ac, pa);
5364
5365 ext4_mb_use_group_pa(ac, pa);
5366 atomic_add(i: pa->pa_free, v: &EXT4_SB(sb)->s_mb_preallocated);
5367
5368 grp = ext4_get_group_info(sb, group: ac->ac_b_ex.fe_group);
5369 if (!grp)
5370 return;
5371 lg = ac->ac_lg;
5372 BUG_ON(lg == NULL);
5373
5374 pa->pa_node_lock.lg_lock = &lg->lg_prealloc_lock;
5375 pa->pa_inode = NULL;
5376
5377 list_add(new: &pa->pa_group_list, head: &grp->bb_prealloc_list);
5378
5379 /*
5380 * We will later add the new pa to the right bucket
5381 * after updating the pa_free in ext4_mb_release_context
5382 */
5383}
5384
5385static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
5386{
5387 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
5388 ext4_mb_new_group_pa(ac);
5389 else
5390 ext4_mb_new_inode_pa(ac);
5391}
5392
5393/*
5394 * finds all unused blocks in on-disk bitmap, frees them in
5395 * in-core bitmap and buddy.
5396 * @pa must be unlinked from inode and group lists, so that
5397 * nobody else can find/use it.
5398 * the caller MUST hold group/inode locks.
5399 * TODO: optimize the case when there are no in-core structures yet
5400 */
5401static noinline_for_stack void
5402ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
5403 struct ext4_prealloc_space *pa)
5404{
5405 struct super_block *sb = e4b->bd_sb;
5406 struct ext4_sb_info *sbi = EXT4_SB(sb);
5407 unsigned int end;
5408 unsigned int next;
5409 ext4_group_t group;
5410 ext4_grpblk_t bit;
5411 unsigned long long grp_blk_start;
5412 int free = 0;
5413
5414 BUG_ON(pa->pa_deleted == 0);
5415 ext4_get_group_no_and_offset(sb, blocknr: pa->pa_pstart, blockgrpp: &group, offsetp: &bit);
5416 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
5417 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
5418 end = bit + pa->pa_len;
5419
5420 while (bit < end) {
5421 bit = mb_find_next_zero_bit(addr: bitmap_bh->b_data, max: end, start: bit);
5422 if (bit >= end)
5423 break;
5424 next = mb_find_next_bit(addr: bitmap_bh->b_data, max: end, start: bit);
5425 mb_debug(sb, "free preallocated %u/%u in group %u\n",
5426 (unsigned) ext4_group_first_block_no(sb, group) + bit,
5427 (unsigned) next - bit, (unsigned) group);
5428 free += next - bit;
5429
5430 trace_ext4_mballoc_discard(sb, NULL, group, start: bit, len: next - bit);
5431 trace_ext4_mb_release_inode_pa(pa, block: (grp_blk_start +
5432 EXT4_C2B(sbi, bit)),
5433 count: next - bit);
5434 mb_free_blocks(inode: pa->pa_inode, e4b, first: bit, count: next - bit);
5435 bit = next + 1;
5436 }
5437 if (free != pa->pa_free) {
5438 ext4_msg(e4b->bd_sb, KERN_CRIT,
5439 "pa %p: logic %lu, phys. %lu, len %d",
5440 pa, (unsigned long) pa->pa_lstart,
5441 (unsigned long) pa->pa_pstart,
5442 pa->pa_len);
5443 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
5444 free, pa->pa_free);
5445 /*
5446 * pa is already deleted so we use the value obtained
5447 * from the bitmap and continue.
5448 */
5449 }
5450 atomic_add(i: free, v: &sbi->s_mb_discarded);
5451}
5452
5453static noinline_for_stack void
5454ext4_mb_release_group_pa(struct ext4_buddy *e4b,
5455 struct ext4_prealloc_space *pa)
5456{
5457 struct super_block *sb = e4b->bd_sb;
5458 ext4_group_t group;
5459 ext4_grpblk_t bit;
5460
5461 trace_ext4_mb_release_group_pa(sb, pa);
5462 BUG_ON(pa->pa_deleted == 0);
5463 ext4_get_group_no_and_offset(sb, blocknr: pa->pa_pstart, blockgrpp: &group, offsetp: &bit);
5464 if (unlikely(group != e4b->bd_group && pa->pa_len != 0)) {
5465 ext4_warning(sb, "bad group: expected %u, group %u, pa_start %llu",
5466 e4b->bd_group, group, pa->pa_pstart);
5467 return;
5468 }
5469 mb_free_blocks(inode: pa->pa_inode, e4b, first: bit, count: pa->pa_len);
5470 atomic_add(i: pa->pa_len, v: &EXT4_SB(sb)->s_mb_discarded);
5471 trace_ext4_mballoc_discard(sb, NULL, group, start: bit, len: pa->pa_len);
5472}
5473
5474/*
5475 * releases all preallocations in given group
5476 *
5477 * first, we need to decide discard policy:
5478 * - when do we discard
5479 * 1) ENOSPC
5480 * - how many do we discard
5481 * 1) how many requested
5482 */
5483static noinline_for_stack int
5484ext4_mb_discard_group_preallocations(struct super_block *sb,
5485 ext4_group_t group, int *busy)
5486{
5487 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
5488 struct buffer_head *bitmap_bh = NULL;
5489 struct ext4_prealloc_space *pa, *tmp;
5490 LIST_HEAD(list);
5491 struct ext4_buddy e4b;
5492 struct ext4_inode_info *ei;
5493 int err;
5494 int free = 0;
5495
5496 if (!grp)
5497 return 0;
5498 mb_debug(sb, "discard preallocation for group %u\n", group);
5499 if (list_empty(head: &grp->bb_prealloc_list))
5500 goto out_dbg;
5501
5502 bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
5503 if (IS_ERR(ptr: bitmap_bh)) {
5504 err = PTR_ERR(ptr: bitmap_bh);
5505 ext4_error_err(sb, -err,
5506 "Error %d reading block bitmap for %u",
5507 err, group);
5508 goto out_dbg;
5509 }
5510
5511 err = ext4_mb_load_buddy(sb, group, e4b: &e4b);
5512 if (err) {
5513 ext4_warning(sb, "Error %d loading buddy information for %u",
5514 err, group);
5515 put_bh(bh: bitmap_bh);
5516 goto out_dbg;
5517 }
5518
5519 ext4_lock_group(sb, group);
5520 list_for_each_entry_safe(pa, tmp,
5521 &grp->bb_prealloc_list, pa_group_list) {
5522 spin_lock(lock: &pa->pa_lock);
5523 if (atomic_read(v: &pa->pa_count)) {
5524 spin_unlock(lock: &pa->pa_lock);
5525 *busy = 1;
5526 continue;
5527 }
5528 if (pa->pa_deleted) {
5529 spin_unlock(lock: &pa->pa_lock);
5530 continue;
5531 }
5532
5533 /* seems this one can be freed ... */
5534 ext4_mb_mark_pa_deleted(sb, pa);
5535
5536 if (!free)
5537 this_cpu_inc(discard_pa_seq);
5538
5539 /* we can trust pa_free ... */
5540 free += pa->pa_free;
5541
5542 spin_unlock(lock: &pa->pa_lock);
5543
5544 list_del(entry: &pa->pa_group_list);
5545 list_add(new: &pa->u.pa_tmp_list, head: &list);
5546 }
5547
5548 /* now free all selected PAs */
5549 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
5550
5551 /* remove from object (inode or locality group) */
5552 if (pa->pa_type == MB_GROUP_PA) {
5553 spin_lock(lock: pa->pa_node_lock.lg_lock);
5554 list_del_rcu(entry: &pa->pa_node.lg_list);
5555 spin_unlock(lock: pa->pa_node_lock.lg_lock);
5556 } else {
5557 write_lock(pa->pa_node_lock.inode_lock);
5558 ei = EXT4_I(pa->pa_inode);
5559 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5560 write_unlock(pa->pa_node_lock.inode_lock);
5561 }
5562
5563 list_del(entry: &pa->u.pa_tmp_list);
5564
5565 if (pa->pa_type == MB_GROUP_PA) {
5566 ext4_mb_release_group_pa(e4b: &e4b, pa);
5567 call_rcu(head: &(pa)->u.pa_rcu, func: ext4_mb_pa_callback);
5568 } else {
5569 ext4_mb_release_inode_pa(e4b: &e4b, bitmap_bh, pa);
5570 ext4_mb_pa_free(pa);
5571 }
5572 }
5573
5574 ext4_unlock_group(sb, group);
5575 ext4_mb_unload_buddy(e4b: &e4b);
5576 put_bh(bh: bitmap_bh);
5577out_dbg:
5578 mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
5579 free, group, grp->bb_free);
5580 return free;
5581}
5582
5583/*
5584 * releases all non-used preallocated blocks for given inode
5585 *
5586 * It's important to discard preallocations under i_data_sem
5587 * We don't want another block to be served from the prealloc
5588 * space when we are discarding the inode prealloc space.
5589 *
5590 * FIXME!! Make sure it is valid at all the call sites
5591 */
5592void ext4_discard_preallocations(struct inode *inode)
5593{
5594 struct ext4_inode_info *ei = EXT4_I(inode);
5595 struct super_block *sb = inode->i_sb;
5596 struct buffer_head *bitmap_bh = NULL;
5597 struct ext4_prealloc_space *pa, *tmp;
5598 ext4_group_t group = 0;
5599 LIST_HEAD(list);
5600 struct ext4_buddy e4b;
5601 struct rb_node *iter;
5602 int err;
5603
5604 if (!S_ISREG(inode->i_mode))
5605 return;
5606
5607 if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
5608 return;
5609
5610 mb_debug(sb, "discard preallocation for inode %lu\n",
5611 inode->i_ino);
5612 trace_ext4_discard_preallocations(inode,
5613 len: atomic_read(v: &ei->i_prealloc_active));
5614
5615repeat:
5616 /* first, collect all pa's in the inode */
5617 write_lock(&ei->i_prealloc_lock);
5618 for (iter = rb_first(&ei->i_prealloc_node); iter;
5619 iter = rb_next(iter)) {
5620 pa = rb_entry(iter, struct ext4_prealloc_space,
5621 pa_node.inode_node);
5622 BUG_ON(pa->pa_node_lock.inode_lock != &ei->i_prealloc_lock);
5623
5624 spin_lock(lock: &pa->pa_lock);
5625 if (atomic_read(v: &pa->pa_count)) {
5626 /* this shouldn't happen often - nobody should
5627 * use preallocation while we're discarding it */
5628 spin_unlock(lock: &pa->pa_lock);
5629 write_unlock(&ei->i_prealloc_lock);
5630 ext4_msg(sb, KERN_ERR,
5631 "uh-oh! used pa while discarding");
5632 WARN_ON(1);
5633 schedule_timeout_uninterruptible(HZ);
5634 goto repeat;
5635
5636 }
5637 if (pa->pa_deleted == 0) {
5638 ext4_mb_mark_pa_deleted(sb, pa);
5639 spin_unlock(lock: &pa->pa_lock);
5640 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5641 list_add(new: &pa->u.pa_tmp_list, head: &list);
5642 continue;
5643 }
5644
5645 /* someone is deleting pa right now */
5646 spin_unlock(lock: &pa->pa_lock);
5647 write_unlock(&ei->i_prealloc_lock);
5648
5649 /* we have to wait here because pa_deleted
5650 * doesn't mean pa is already unlinked from
5651 * the list. as we might be called from
5652 * ->clear_inode() the inode will get freed
5653 * and concurrent thread which is unlinking
5654 * pa from inode's list may access already
5655 * freed memory, bad-bad-bad */
5656
5657 /* XXX: if this happens too often, we can
5658 * add a flag to force wait only in case
5659 * of ->clear_inode(), but not in case of
5660 * regular truncate */
5661 schedule_timeout_uninterruptible(HZ);
5662 goto repeat;
5663 }
5664 write_unlock(&ei->i_prealloc_lock);
5665
5666 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
5667 BUG_ON(pa->pa_type != MB_INODE_PA);
5668 group = ext4_get_group_number(sb, block: pa->pa_pstart);
5669
5670 err = ext4_mb_load_buddy_gfp(sb, group, e4b: &e4b,
5671 GFP_NOFS|__GFP_NOFAIL);
5672 if (err) {
5673 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5674 err, group);
5675 continue;
5676 }
5677
5678 bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
5679 if (IS_ERR(ptr: bitmap_bh)) {
5680 err = PTR_ERR(ptr: bitmap_bh);
5681 ext4_error_err(sb, -err, "Error %d reading block bitmap for %u",
5682 err, group);
5683 ext4_mb_unload_buddy(e4b: &e4b);
5684 continue;
5685 }
5686
5687 ext4_lock_group(sb, group);
5688 list_del(entry: &pa->pa_group_list);
5689 ext4_mb_release_inode_pa(e4b: &e4b, bitmap_bh, pa);
5690 ext4_unlock_group(sb, group);
5691
5692 ext4_mb_unload_buddy(e4b: &e4b);
5693 put_bh(bh: bitmap_bh);
5694
5695 list_del(entry: &pa->u.pa_tmp_list);
5696 ext4_mb_pa_free(pa);
5697 }
5698}
5699
5700static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac)
5701{
5702 struct ext4_prealloc_space *pa;
5703
5704 BUG_ON(ext4_pspace_cachep == NULL);
5705 pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS);
5706 if (!pa)
5707 return -ENOMEM;
5708 atomic_set(v: &pa->pa_count, i: 1);
5709 ac->ac_pa = pa;
5710 return 0;
5711}
5712
5713static void ext4_mb_pa_put_free(struct ext4_allocation_context *ac)
5714{
5715 struct ext4_prealloc_space *pa = ac->ac_pa;
5716
5717 BUG_ON(!pa);
5718 ac->ac_pa = NULL;
5719 WARN_ON(!atomic_dec_and_test(&pa->pa_count));
5720 /*
5721 * current function is only called due to an error or due to
5722 * len of found blocks < len of requested blocks hence the PA has not
5723 * been added to grp->bb_prealloc_list. So we don't need to lock it
5724 */
5725 pa->pa_deleted = 1;
5726 ext4_mb_pa_free(pa);
5727}
5728
5729#ifdef CONFIG_EXT4_DEBUG
5730static inline void ext4_mb_show_pa(struct super_block *sb)
5731{
5732 ext4_group_t i, ngroups;
5733
5734 if (ext4_emergency_state(sb))
5735 return;
5736
5737 ngroups = ext4_get_groups_count(sb);
5738 mb_debug(sb, "groups: ");
5739 for (i = 0; i < ngroups; i++) {
5740 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
5741 struct ext4_prealloc_space *pa;
5742 ext4_grpblk_t start;
5743 struct list_head *cur;
5744
5745 if (!grp)
5746 continue;
5747 ext4_lock_group(sb, i);
5748 list_for_each(cur, &grp->bb_prealloc_list) {
5749 pa = list_entry(cur, struct ext4_prealloc_space,
5750 pa_group_list);
5751 spin_lock(&pa->pa_lock);
5752 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
5753 NULL, &start);
5754 spin_unlock(&pa->pa_lock);
5755 mb_debug(sb, "PA:%u:%d:%d\n", i, start,
5756 pa->pa_len);
5757 }
5758 ext4_unlock_group(sb, i);
5759 mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free,
5760 grp->bb_fragments);
5761 }
5762}
5763
5764static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5765{
5766 struct super_block *sb = ac->ac_sb;
5767
5768 if (ext4_emergency_state(sb))
5769 return;
5770
5771 mb_debug(sb, "Can't allocate:"
5772 " Allocation context details:");
5773 mb_debug(sb, "status %u flags 0x%x",
5774 ac->ac_status, ac->ac_flags);
5775 mb_debug(sb, "orig %lu/%lu/%lu@%lu, "
5776 "goal %lu/%lu/%lu@%lu, "
5777 "best %lu/%lu/%lu@%lu cr %d",
5778 (unsigned long)ac->ac_o_ex.fe_group,
5779 (unsigned long)ac->ac_o_ex.fe_start,
5780 (unsigned long)ac->ac_o_ex.fe_len,
5781 (unsigned long)ac->ac_o_ex.fe_logical,
5782 (unsigned long)ac->ac_g_ex.fe_group,
5783 (unsigned long)ac->ac_g_ex.fe_start,
5784 (unsigned long)ac->ac_g_ex.fe_len,
5785 (unsigned long)ac->ac_g_ex.fe_logical,
5786 (unsigned long)ac->ac_b_ex.fe_group,
5787 (unsigned long)ac->ac_b_ex.fe_start,
5788 (unsigned long)ac->ac_b_ex.fe_len,
5789 (unsigned long)ac->ac_b_ex.fe_logical,
5790 (int)ac->ac_criteria);
5791 mb_debug(sb, "%u found", ac->ac_found);
5792 mb_debug(sb, "used pa: %s, ", str_yes_no(ac->ac_pa));
5793 if (ac->ac_pa)
5794 mb_debug(sb, "pa_type %s\n", ac->ac_pa->pa_type == MB_GROUP_PA ?
5795 "group pa" : "inode pa");
5796 ext4_mb_show_pa(sb);
5797}
5798#else
5799static inline void ext4_mb_show_pa(struct super_block *sb)
5800{
5801}
5802static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5803{
5804 ext4_mb_show_pa(sb: ac->ac_sb);
5805}
5806#endif
5807
5808/*
5809 * We use locality group preallocation for small size file. The size of the
5810 * file is determined by the current size or the resulting size after
5811 * allocation which ever is larger
5812 *
5813 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
5814 */
5815static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
5816{
5817 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
5818 int bsbits = ac->ac_sb->s_blocksize_bits;
5819 loff_t size, isize;
5820 bool inode_pa_eligible, group_pa_eligible;
5821
5822 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
5823 return;
5824
5825 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
5826 return;
5827
5828 group_pa_eligible = sbi->s_mb_group_prealloc > 0;
5829 inode_pa_eligible = true;
5830 size = extent_logical_end(sbi, fex: &ac->ac_o_ex);
5831 isize = (i_size_read(inode: ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
5832 >> bsbits;
5833
5834 /* No point in using inode preallocation for closed files */
5835 if ((size == isize) && !ext4_fs_is_busy(sbi) &&
5836 !inode_is_open_for_write(inode: ac->ac_inode))
5837 inode_pa_eligible = false;
5838
5839 size = max(size, isize);
5840 /* Don't use group allocation for large files */
5841 if (size > sbi->s_mb_stream_request)
5842 group_pa_eligible = false;
5843
5844 if (!group_pa_eligible) {
5845 if (inode_pa_eligible)
5846 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
5847 else
5848 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
5849 return;
5850 }
5851
5852 BUG_ON(ac->ac_lg != NULL);
5853 /*
5854 * locality group prealloc space are per cpu. The reason for having
5855 * per cpu locality group is to reduce the contention between block
5856 * request from multiple CPUs.
5857 */
5858 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
5859
5860 /* we're going to use group allocation */
5861 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
5862
5863 /* serialize all allocations in the group */
5864 mutex_lock(lock: &ac->ac_lg->lg_mutex);
5865}
5866
5867static noinline_for_stack void
5868ext4_mb_initialize_context(struct ext4_allocation_context *ac,
5869 struct ext4_allocation_request *ar)
5870{
5871 struct super_block *sb = ar->inode->i_sb;
5872 struct ext4_sb_info *sbi = EXT4_SB(sb);
5873 struct ext4_super_block *es = sbi->s_es;
5874 ext4_group_t group;
5875 unsigned int len;
5876 ext4_fsblk_t goal;
5877 ext4_grpblk_t block;
5878
5879 /* we can't allocate > group size */
5880 len = ar->len;
5881
5882 /* just a dirty hack to filter too big requests */
5883 if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
5884 len = EXT4_CLUSTERS_PER_GROUP(sb);
5885
5886 /* start searching from the goal */
5887 goal = ar->goal;
5888 if (goal < le32_to_cpu(es->s_first_data_block) ||
5889 goal >= ext4_blocks_count(es))
5890 goal = le32_to_cpu(es->s_first_data_block);
5891 ext4_get_group_no_and_offset(sb, blocknr: goal, blockgrpp: &group, offsetp: &block);
5892
5893 /* set up allocation goals */
5894 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
5895 ac->ac_status = AC_STATUS_CONTINUE;
5896 ac->ac_sb = sb;
5897 ac->ac_inode = ar->inode;
5898 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
5899 ac->ac_o_ex.fe_group = group;
5900 ac->ac_o_ex.fe_start = block;
5901 ac->ac_o_ex.fe_len = len;
5902 ac->ac_g_ex = ac->ac_o_ex;
5903 ac->ac_orig_goal_len = ac->ac_g_ex.fe_len;
5904 ac->ac_flags = ar->flags;
5905
5906 /* we have to define context: we'll work with a file or
5907 * locality group. this is a policy, actually */
5908 ext4_mb_group_or_file(ac);
5909
5910 mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, "
5911 "left: %u/%u, right %u/%u to %swritable\n",
5912 (unsigned) ar->len, (unsigned) ar->logical,
5913 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
5914 (unsigned) ar->lleft, (unsigned) ar->pleft,
5915 (unsigned) ar->lright, (unsigned) ar->pright,
5916 inode_is_open_for_write(ar->inode) ? "" : "non-");
5917}
5918
5919static noinline_for_stack void
5920ext4_mb_discard_lg_preallocations(struct super_block *sb,
5921 struct ext4_locality_group *lg,
5922 int order, int total_entries)
5923{
5924 ext4_group_t group = 0;
5925 struct ext4_buddy e4b;
5926 LIST_HEAD(discard_list);
5927 struct ext4_prealloc_space *pa, *tmp;
5928
5929 mb_debug(sb, "discard locality group preallocation\n");
5930
5931 spin_lock(lock: &lg->lg_prealloc_lock);
5932 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
5933 pa_node.lg_list,
5934 lockdep_is_held(&lg->lg_prealloc_lock)) {
5935 spin_lock(lock: &pa->pa_lock);
5936 if (atomic_read(v: &pa->pa_count)) {
5937 /*
5938 * This is the pa that we just used
5939 * for block allocation. So don't
5940 * free that
5941 */
5942 spin_unlock(lock: &pa->pa_lock);
5943 continue;
5944 }
5945 if (pa->pa_deleted) {
5946 spin_unlock(lock: &pa->pa_lock);
5947 continue;
5948 }
5949 /* only lg prealloc space */
5950 BUG_ON(pa->pa_type != MB_GROUP_PA);
5951
5952 /* seems this one can be freed ... */
5953 ext4_mb_mark_pa_deleted(sb, pa);
5954 spin_unlock(lock: &pa->pa_lock);
5955
5956 list_del_rcu(entry: &pa->pa_node.lg_list);
5957 list_add(new: &pa->u.pa_tmp_list, head: &discard_list);
5958
5959 total_entries--;
5960 if (total_entries <= 5) {
5961 /*
5962 * we want to keep only 5 entries
5963 * allowing it to grow to 8. This
5964 * mak sure we don't call discard
5965 * soon for this list.
5966 */
5967 break;
5968 }
5969 }
5970 spin_unlock(lock: &lg->lg_prealloc_lock);
5971
5972 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
5973 int err;
5974
5975 group = ext4_get_group_number(sb, block: pa->pa_pstart);
5976 err = ext4_mb_load_buddy_gfp(sb, group, e4b: &e4b,
5977 GFP_NOFS|__GFP_NOFAIL);
5978 if (err) {
5979 ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5980 err, group);
5981 continue;
5982 }
5983 ext4_lock_group(sb, group);
5984 list_del(entry: &pa->pa_group_list);
5985 ext4_mb_release_group_pa(e4b: &e4b, pa);
5986 ext4_unlock_group(sb, group);
5987
5988 ext4_mb_unload_buddy(e4b: &e4b);
5989 list_del(entry: &pa->u.pa_tmp_list);
5990 call_rcu(head: &(pa)->u.pa_rcu, func: ext4_mb_pa_callback);
5991 }
5992}
5993
5994/*
5995 * We have incremented pa_count. So it cannot be freed at this
5996 * point. Also we hold lg_mutex. So no parallel allocation is
5997 * possible from this lg. That means pa_free cannot be updated.
5998 *
5999 * A parallel ext4_mb_discard_group_preallocations is possible.
6000 * which can cause the lg_prealloc_list to be updated.
6001 */
6002
6003static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
6004{
6005 int order, added = 0, lg_prealloc_count = 1;
6006 struct super_block *sb = ac->ac_sb;
6007 struct ext4_locality_group *lg = ac->ac_lg;
6008 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
6009
6010 order = fls(x: pa->pa_free) - 1;
6011 if (order > PREALLOC_TB_SIZE - 1)
6012 /* The max size of hash table is PREALLOC_TB_SIZE */
6013 order = PREALLOC_TB_SIZE - 1;
6014 /* Add the prealloc space to lg */
6015 spin_lock(lock: &lg->lg_prealloc_lock);
6016 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
6017 pa_node.lg_list,
6018 lockdep_is_held(&lg->lg_prealloc_lock)) {
6019 spin_lock(lock: &tmp_pa->pa_lock);
6020 if (tmp_pa->pa_deleted) {
6021 spin_unlock(lock: &tmp_pa->pa_lock);
6022 continue;
6023 }
6024 if (!added && pa->pa_free < tmp_pa->pa_free) {
6025 /* Add to the tail of the previous entry */
6026 list_add_tail_rcu(new: &pa->pa_node.lg_list,
6027 head: &tmp_pa->pa_node.lg_list);
6028 added = 1;
6029 /*
6030 * we want to count the total
6031 * number of entries in the list
6032 */
6033 }
6034 spin_unlock(lock: &tmp_pa->pa_lock);
6035 lg_prealloc_count++;
6036 }
6037 if (!added)
6038 list_add_tail_rcu(new: &pa->pa_node.lg_list,
6039 head: &lg->lg_prealloc_list[order]);
6040 spin_unlock(lock: &lg->lg_prealloc_lock);
6041
6042 /* Now trim the list to be not more than 8 elements */
6043 if (lg_prealloc_count > 8)
6044 ext4_mb_discard_lg_preallocations(sb, lg,
6045 order, total_entries: lg_prealloc_count);
6046}
6047
6048/*
6049 * release all resource we used in allocation
6050 */
6051static void ext4_mb_release_context(struct ext4_allocation_context *ac)
6052{
6053 struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
6054 struct ext4_prealloc_space *pa = ac->ac_pa;
6055 if (pa) {
6056 if (pa->pa_type == MB_GROUP_PA) {
6057 /* see comment in ext4_mb_use_group_pa() */
6058 spin_lock(lock: &pa->pa_lock);
6059 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
6060 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
6061 pa->pa_free -= ac->ac_b_ex.fe_len;
6062 pa->pa_len -= ac->ac_b_ex.fe_len;
6063 spin_unlock(lock: &pa->pa_lock);
6064
6065 /*
6066 * We want to add the pa to the right bucket.
6067 * Remove it from the list and while adding
6068 * make sure the list to which we are adding
6069 * doesn't grow big.
6070 */
6071 if (likely(pa->pa_free)) {
6072 spin_lock(lock: pa->pa_node_lock.lg_lock);
6073 list_del_rcu(entry: &pa->pa_node.lg_list);
6074 spin_unlock(lock: pa->pa_node_lock.lg_lock);
6075 ext4_mb_add_n_trim(ac);
6076 }
6077 }
6078
6079 ext4_mb_put_pa(ac, sb: ac->ac_sb, pa);
6080 }
6081 if (ac->ac_bitmap_folio)
6082 folio_put(folio: ac->ac_bitmap_folio);
6083 if (ac->ac_buddy_folio)
6084 folio_put(folio: ac->ac_buddy_folio);
6085 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
6086 mutex_unlock(lock: &ac->ac_lg->lg_mutex);
6087 ext4_mb_collect_stats(ac);
6088}
6089
6090static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
6091{
6092 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
6093 int ret;
6094 int freed = 0, busy = 0;
6095 int retry = 0;
6096
6097 trace_ext4_mb_discard_preallocations(sb, needed);
6098
6099 if (needed == 0)
6100 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
6101 repeat:
6102 for (i = 0; i < ngroups && needed > 0; i++) {
6103 ret = ext4_mb_discard_group_preallocations(sb, group: i, busy: &busy);
6104 freed += ret;
6105 needed -= ret;
6106 cond_resched();
6107 }
6108
6109 if (needed > 0 && busy && ++retry < 3) {
6110 busy = 0;
6111 goto repeat;
6112 }
6113
6114 return freed;
6115}
6116
6117static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb,
6118 struct ext4_allocation_context *ac, u64 *seq)
6119{
6120 int freed;
6121 u64 seq_retry = 0;
6122 bool ret = false;
6123
6124 freed = ext4_mb_discard_preallocations(sb, needed: ac->ac_o_ex.fe_len);
6125 if (freed) {
6126 ret = true;
6127 goto out_dbg;
6128 }
6129 seq_retry = ext4_get_discard_pa_seq_sum();
6130 if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) {
6131 ac->ac_flags |= EXT4_MB_STRICT_CHECK;
6132 *seq = seq_retry;
6133 ret = true;
6134 }
6135
6136out_dbg:
6137 mb_debug(sb, "freed %d, retry ? %s\n", freed, str_yes_no(ret));
6138 return ret;
6139}
6140
6141/*
6142 * Simple allocator for Ext4 fast commit replay path. It searches for blocks
6143 * linearly starting at the goal block and also excludes the blocks which
6144 * are going to be in use after fast commit replay.
6145 */
6146static ext4_fsblk_t
6147ext4_mb_new_blocks_simple(struct ext4_allocation_request *ar, int *errp)
6148{
6149 struct buffer_head *bitmap_bh;
6150 struct super_block *sb = ar->inode->i_sb;
6151 struct ext4_sb_info *sbi = EXT4_SB(sb);
6152 ext4_group_t group, nr;
6153 ext4_grpblk_t blkoff;
6154 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
6155 ext4_grpblk_t i = 0;
6156 ext4_fsblk_t goal, block;
6157 struct ext4_super_block *es = sbi->s_es;
6158
6159 goal = ar->goal;
6160 if (goal < le32_to_cpu(es->s_first_data_block) ||
6161 goal >= ext4_blocks_count(es))
6162 goal = le32_to_cpu(es->s_first_data_block);
6163
6164 ar->len = 0;
6165 ext4_get_group_no_and_offset(sb, blocknr: goal, blockgrpp: &group, offsetp: &blkoff);
6166 for (nr = ext4_get_groups_count(sb); nr > 0; nr--) {
6167 bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
6168 if (IS_ERR(ptr: bitmap_bh)) {
6169 *errp = PTR_ERR(ptr: bitmap_bh);
6170 pr_warn("Failed to read block bitmap\n");
6171 return 0;
6172 }
6173
6174 while (1) {
6175 i = mb_find_next_zero_bit(addr: bitmap_bh->b_data, max,
6176 start: blkoff);
6177 if (i >= max)
6178 break;
6179 if (ext4_fc_replay_check_excluded(sb,
6180 block: ext4_group_first_block_no(sb, group_no: group) +
6181 EXT4_C2B(sbi, i))) {
6182 blkoff = i + 1;
6183 } else
6184 break;
6185 }
6186 brelse(bh: bitmap_bh);
6187 if (i < max)
6188 break;
6189
6190 if (++group >= ext4_get_groups_count(sb))
6191 group = 0;
6192
6193 blkoff = 0;
6194 }
6195
6196 if (i >= max) {
6197 *errp = -ENOSPC;
6198 return 0;
6199 }
6200
6201 block = ext4_group_first_block_no(sb, group_no: group) + EXT4_C2B(sbi, i);
6202 ext4_mb_mark_bb(sb, block, len: 1, state: true);
6203 ar->len = 1;
6204
6205 *errp = 0;
6206 return block;
6207}
6208
6209/*
6210 * Main entry point into mballoc to allocate blocks
6211 * it tries to use preallocation first, then falls back
6212 * to usual allocation
6213 */
6214ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
6215 struct ext4_allocation_request *ar, int *errp)
6216{
6217 struct ext4_allocation_context *ac = NULL;
6218 struct ext4_sb_info *sbi;
6219 struct super_block *sb;
6220 ext4_fsblk_t block = 0;
6221 unsigned int inquota = 0;
6222 unsigned int reserv_clstrs = 0;
6223 int retries = 0;
6224 u64 seq;
6225
6226 might_sleep();
6227 sb = ar->inode->i_sb;
6228 sbi = EXT4_SB(sb);
6229
6230 trace_ext4_request_blocks(ar);
6231 if (sbi->s_mount_state & EXT4_FC_REPLAY)
6232 return ext4_mb_new_blocks_simple(ar, errp);
6233
6234 /* Allow to use superuser reservation for quota file */
6235 if (ext4_is_quota_file(inode: ar->inode))
6236 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
6237
6238 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
6239 /* Without delayed allocation we need to verify
6240 * there is enough free blocks to do block allocation
6241 * and verify allocation doesn't exceed the quota limits.
6242 */
6243 while (ar->len &&
6244 ext4_claim_free_clusters(sbi, nclusters: ar->len, flags: ar->flags)) {
6245
6246 /* let others to free the space */
6247 cond_resched();
6248 ar->len = ar->len >> 1;
6249 }
6250 if (!ar->len) {
6251 ext4_mb_show_pa(sb);
6252 *errp = -ENOSPC;
6253 return 0;
6254 }
6255 reserv_clstrs = ar->len;
6256 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
6257 dquot_alloc_block_nofail(inode: ar->inode,
6258 EXT4_C2B(sbi, ar->len));
6259 } else {
6260 while (ar->len &&
6261 dquot_alloc_block(inode: ar->inode,
6262 EXT4_C2B(sbi, ar->len))) {
6263
6264 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
6265 ar->len--;
6266 }
6267 }
6268 inquota = ar->len;
6269 if (ar->len == 0) {
6270 *errp = -EDQUOT;
6271 goto out;
6272 }
6273 }
6274
6275 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
6276 if (!ac) {
6277 ar->len = 0;
6278 *errp = -ENOMEM;
6279 goto out;
6280 }
6281
6282 ext4_mb_initialize_context(ac, ar);
6283
6284 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
6285 seq = this_cpu_read(discard_pa_seq);
6286 if (!ext4_mb_use_preallocated(ac)) {
6287 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
6288 ext4_mb_normalize_request(ac, ar);
6289
6290 *errp = ext4_mb_pa_alloc(ac);
6291 if (*errp)
6292 goto errout;
6293repeat:
6294 /* allocate space in core */
6295 *errp = ext4_mb_regular_allocator(ac);
6296 /*
6297 * pa allocated above is added to grp->bb_prealloc_list only
6298 * when we were able to allocate some block i.e. when
6299 * ac->ac_status == AC_STATUS_FOUND.
6300 * And error from above mean ac->ac_status != AC_STATUS_FOUND
6301 * So we have to free this pa here itself.
6302 */
6303 if (*errp) {
6304 ext4_mb_pa_put_free(ac);
6305 ext4_discard_allocated_blocks(ac);
6306 goto errout;
6307 }
6308 if (ac->ac_status == AC_STATUS_FOUND &&
6309 ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len)
6310 ext4_mb_pa_put_free(ac);
6311 }
6312 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
6313 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
6314 if (*errp) {
6315 ext4_discard_allocated_blocks(ac);
6316 goto errout;
6317 } else {
6318 block = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
6319 ar->len = ac->ac_b_ex.fe_len;
6320 }
6321 } else {
6322 if (++retries < 3 &&
6323 ext4_mb_discard_preallocations_should_retry(sb, ac, seq: &seq))
6324 goto repeat;
6325 /*
6326 * If block allocation fails then the pa allocated above
6327 * needs to be freed here itself.
6328 */
6329 ext4_mb_pa_put_free(ac);
6330 *errp = -ENOSPC;
6331 }
6332
6333 if (*errp) {
6334errout:
6335 ac->ac_b_ex.fe_len = 0;
6336 ar->len = 0;
6337 ext4_mb_show_ac(ac);
6338 }
6339 ext4_mb_release_context(ac);
6340 kmem_cache_free(s: ext4_ac_cachep, objp: ac);
6341out:
6342 if (inquota && ar->len < inquota)
6343 dquot_free_block(inode: ar->inode, EXT4_C2B(sbi, inquota - ar->len));
6344 if (!ar->len) {
6345 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
6346 /* release all the reserved blocks if non delalloc */
6347 percpu_counter_sub(fbc: &sbi->s_dirtyclusters_counter,
6348 amount: reserv_clstrs);
6349 }
6350
6351 trace_ext4_allocate_blocks(ar, block: (unsigned long long)block);
6352
6353 return block;
6354}
6355
6356/*
6357 * We can merge two free data extents only if the physical blocks
6358 * are contiguous, AND the extents were freed by the same transaction,
6359 * AND the blocks are associated with the same group.
6360 */
6361static inline bool
6362ext4_freed_extents_can_be_merged(struct ext4_free_data *entry1,
6363 struct ext4_free_data *entry2)
6364{
6365 if (entry1->efd_tid != entry2->efd_tid)
6366 return false;
6367 if (entry1->efd_start_cluster + entry1->efd_count !=
6368 entry2->efd_start_cluster)
6369 return false;
6370 if (WARN_ON_ONCE(entry1->efd_group != entry2->efd_group))
6371 return false;
6372 return true;
6373}
6374
6375static inline void
6376ext4_merge_freed_extents(struct ext4_sb_info *sbi, struct rb_root *root,
6377 struct ext4_free_data *entry1,
6378 struct ext4_free_data *entry2)
6379{
6380 entry1->efd_count += entry2->efd_count;
6381 spin_lock(lock: &sbi->s_md_lock);
6382 list_del(entry: &entry2->efd_list);
6383 spin_unlock(lock: &sbi->s_md_lock);
6384 rb_erase(&entry2->efd_node, root);
6385 kmem_cache_free(s: ext4_free_data_cachep, objp: entry2);
6386}
6387
6388static inline void
6389ext4_try_merge_freed_extent_prev(struct ext4_sb_info *sbi, struct rb_root *root,
6390 struct ext4_free_data *entry)
6391{
6392 struct ext4_free_data *prev;
6393 struct rb_node *node;
6394
6395 node = rb_prev(&entry->efd_node);
6396 if (!node)
6397 return;
6398
6399 prev = rb_entry(node, struct ext4_free_data, efd_node);
6400 if (ext4_freed_extents_can_be_merged(entry1: prev, entry2: entry))
6401 ext4_merge_freed_extents(sbi, root, entry1: prev, entry2: entry);
6402}
6403
6404static inline void
6405ext4_try_merge_freed_extent_next(struct ext4_sb_info *sbi, struct rb_root *root,
6406 struct ext4_free_data *entry)
6407{
6408 struct ext4_free_data *next;
6409 struct rb_node *node;
6410
6411 node = rb_next(&entry->efd_node);
6412 if (!node)
6413 return;
6414
6415 next = rb_entry(node, struct ext4_free_data, efd_node);
6416 if (ext4_freed_extents_can_be_merged(entry1: entry, entry2: next))
6417 ext4_merge_freed_extents(sbi, root, entry1: entry, entry2: next);
6418}
6419
6420static noinline_for_stack void
6421ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
6422 struct ext4_free_data *new_entry)
6423{
6424 ext4_group_t group = e4b->bd_group;
6425 ext4_grpblk_t cluster;
6426 ext4_grpblk_t clusters = new_entry->efd_count;
6427 struct ext4_free_data *entry = NULL;
6428 struct ext4_group_info *db = e4b->bd_info;
6429 struct super_block *sb = e4b->bd_sb;
6430 struct ext4_sb_info *sbi = EXT4_SB(sb);
6431 struct rb_root *root = &db->bb_free_root;
6432 struct rb_node **n = &root->rb_node;
6433 struct rb_node *parent = NULL, *new_node;
6434
6435 BUG_ON(!ext4_handle_valid(handle));
6436 BUG_ON(e4b->bd_bitmap_folio == NULL);
6437 BUG_ON(e4b->bd_buddy_folio == NULL);
6438
6439 new_node = &new_entry->efd_node;
6440 cluster = new_entry->efd_start_cluster;
6441
6442 if (!*n) {
6443 /* first free block exent. We need to
6444 protect buddy cache from being freed,
6445 * otherwise we'll refresh it from
6446 * on-disk bitmap and lose not-yet-available
6447 * blocks */
6448 folio_get(folio: e4b->bd_buddy_folio);
6449 folio_get(folio: e4b->bd_bitmap_folio);
6450 }
6451 while (*n) {
6452 parent = *n;
6453 entry = rb_entry(parent, struct ext4_free_data, efd_node);
6454 if (cluster < entry->efd_start_cluster)
6455 n = &(*n)->rb_left;
6456 else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
6457 n = &(*n)->rb_right;
6458 else {
6459 ext4_grp_locked_error(sb, group, 0,
6460 ext4_group_first_block_no(sb, group) +
6461 EXT4_C2B(sbi, cluster),
6462 "Block already on to-be-freed list");
6463 kmem_cache_free(s: ext4_free_data_cachep, objp: new_entry);
6464 return;
6465 }
6466 }
6467
6468 atomic_add(i: clusters, v: &sbi->s_mb_free_pending);
6469 if (!entry)
6470 goto insert;
6471
6472 /* Now try to see the extent can be merged to prev and next */
6473 if (ext4_freed_extents_can_be_merged(entry1: new_entry, entry2: entry)) {
6474 entry->efd_start_cluster = cluster;
6475 entry->efd_count += new_entry->efd_count;
6476 kmem_cache_free(s: ext4_free_data_cachep, objp: new_entry);
6477 ext4_try_merge_freed_extent_prev(sbi, root, entry);
6478 return;
6479 }
6480 if (ext4_freed_extents_can_be_merged(entry1: entry, entry2: new_entry)) {
6481 entry->efd_count += new_entry->efd_count;
6482 kmem_cache_free(s: ext4_free_data_cachep, objp: new_entry);
6483 ext4_try_merge_freed_extent_next(sbi, root, entry);
6484 return;
6485 }
6486insert:
6487 rb_link_node(node: new_node, parent, rb_link: n);
6488 rb_insert_color(new_node, root);
6489
6490 spin_lock(lock: &sbi->s_md_lock);
6491 list_add_tail(new: &new_entry->efd_list, head: &sbi->s_freed_data_list[new_entry->efd_tid & 1]);
6492 spin_unlock(lock: &sbi->s_md_lock);
6493}
6494
6495static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
6496 unsigned long count)
6497{
6498 struct super_block *sb = inode->i_sb;
6499 ext4_group_t group;
6500 ext4_grpblk_t blkoff;
6501
6502 ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &group, offsetp: &blkoff);
6503 ext4_mb_mark_context(NULL, sb, state: false, group, blkoff, len: count,
6504 EXT4_MB_BITMAP_MARKED_CHECK |
6505 EXT4_MB_SYNC_UPDATE,
6506 NULL);
6507}
6508
6509/**
6510 * ext4_mb_clear_bb() -- helper function for freeing blocks.
6511 * Used by ext4_free_blocks()
6512 * @handle: handle for this transaction
6513 * @inode: inode
6514 * @block: starting physical block to be freed
6515 * @count: number of blocks to be freed
6516 * @flags: flags used by ext4_free_blocks
6517 */
6518static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
6519 ext4_fsblk_t block, unsigned long count,
6520 int flags)
6521{
6522 struct super_block *sb = inode->i_sb;
6523 struct ext4_group_info *grp;
6524 unsigned int overflow;
6525 ext4_grpblk_t bit;
6526 ext4_group_t block_group;
6527 struct ext4_sb_info *sbi;
6528 struct ext4_buddy e4b;
6529 unsigned int count_clusters;
6530 int err = 0;
6531 int mark_flags = 0;
6532 ext4_grpblk_t changed;
6533
6534 sbi = EXT4_SB(sb);
6535
6536 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6537 !ext4_inode_block_valid(inode, start_blk: block, count)) {
6538 ext4_error(sb, "Freeing blocks in system zone - "
6539 "Block = %llu, count = %lu", block, count);
6540 /* err = 0. ext4_std_error should be a no op */
6541 goto error_out;
6542 }
6543 flags |= EXT4_FREE_BLOCKS_VALIDATED;
6544
6545do_more:
6546 overflow = 0;
6547 ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &block_group, offsetp: &bit);
6548
6549 grp = ext4_get_group_info(sb, group: block_group);
6550 if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
6551 return;
6552
6553 /*
6554 * Check to see if we are freeing blocks across a group
6555 * boundary.
6556 */
6557 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
6558 overflow = EXT4_C2B(sbi, bit) + count -
6559 EXT4_BLOCKS_PER_GROUP(sb);
6560 count -= overflow;
6561 /* The range changed so it's no longer validated */
6562 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6563 }
6564 count_clusters = EXT4_NUM_B2C(sbi, count);
6565 trace_ext4_mballoc_free(sb, inode, group: block_group, start: bit, len: count_clusters);
6566
6567 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
6568 err = ext4_mb_load_buddy_gfp(sb, group: block_group, e4b: &e4b,
6569 GFP_NOFS|__GFP_NOFAIL);
6570 if (err)
6571 goto error_out;
6572
6573 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6574 !ext4_inode_block_valid(inode, start_blk: block, count)) {
6575 ext4_error(sb, "Freeing blocks in system zone - "
6576 "Block = %llu, count = %lu", block, count);
6577 /* err = 0. ext4_std_error should be a no op */
6578 goto error_clean;
6579 }
6580
6581#ifdef AGGRESSIVE_CHECK
6582 mark_flags |= EXT4_MB_BITMAP_MARKED_CHECK;
6583#endif
6584 err = ext4_mb_mark_context(handle, sb, state: false, group: block_group, blkoff: bit,
6585 len: count_clusters, flags: mark_flags, ret_changed: &changed);
6586
6587
6588 if (err && changed == 0)
6589 goto error_clean;
6590
6591#ifdef AGGRESSIVE_CHECK
6592 BUG_ON(changed != count_clusters);
6593#endif
6594
6595 /*
6596 * We need to make sure we don't reuse the freed block until after the
6597 * transaction is committed. We make an exception if the inode is to be
6598 * written in writeback mode since writeback mode has weak data
6599 * consistency guarantees.
6600 */
6601 if (ext4_handle_valid(handle) &&
6602 ((flags & EXT4_FREE_BLOCKS_METADATA) ||
6603 !ext4_should_writeback_data(inode))) {
6604 struct ext4_free_data *new_entry;
6605 /*
6606 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
6607 * to fail.
6608 */
6609 new_entry = kmem_cache_alloc(ext4_free_data_cachep,
6610 GFP_NOFS|__GFP_NOFAIL);
6611 new_entry->efd_start_cluster = bit;
6612 new_entry->efd_group = block_group;
6613 new_entry->efd_count = count_clusters;
6614 new_entry->efd_tid = handle->h_transaction->t_tid;
6615
6616 ext4_lock_group(sb, group: block_group);
6617 ext4_mb_free_metadata(handle, e4b: &e4b, new_entry);
6618 } else {
6619 if (test_opt(sb, DISCARD)) {
6620 err = ext4_issue_discard(sb, block_group, cluster: bit,
6621 count: count_clusters);
6622 /*
6623 * Ignore EOPNOTSUPP error. This is consistent with
6624 * what happens when using journal.
6625 */
6626 if (err == -EOPNOTSUPP)
6627 err = 0;
6628 if (err)
6629 ext4_msg(sb, KERN_WARNING, "discard request in"
6630 " group:%u block:%d count:%lu failed"
6631 " with %d", block_group, bit, count,
6632 err);
6633 }
6634
6635 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
6636
6637 ext4_lock_group(sb, group: block_group);
6638 mb_free_blocks(inode, e4b: &e4b, first: bit, count: count_clusters);
6639 }
6640
6641 ext4_unlock_group(sb, group: block_group);
6642
6643 /*
6644 * on a bigalloc file system, defer the s_freeclusters_counter
6645 * update to the caller (ext4_remove_space and friends) so they
6646 * can determine if a cluster freed here should be rereserved
6647 */
6648 if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
6649 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
6650 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
6651 percpu_counter_add(fbc: &sbi->s_freeclusters_counter,
6652 amount: count_clusters);
6653 }
6654
6655 if (overflow && !err) {
6656 block += count;
6657 count = overflow;
6658 ext4_mb_unload_buddy(e4b: &e4b);
6659 /* The range changed so it's no longer validated */
6660 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6661 goto do_more;
6662 }
6663
6664error_clean:
6665 ext4_mb_unload_buddy(e4b: &e4b);
6666error_out:
6667 ext4_std_error(sb, err);
6668}
6669
6670/**
6671 * ext4_free_blocks() -- Free given blocks and update quota
6672 * @handle: handle for this transaction
6673 * @inode: inode
6674 * @bh: optional buffer of the block to be freed
6675 * @block: starting physical block to be freed
6676 * @count: number of blocks to be freed
6677 * @flags: flags used by ext4_free_blocks
6678 */
6679void ext4_free_blocks(handle_t *handle, struct inode *inode,
6680 struct buffer_head *bh, ext4_fsblk_t block,
6681 unsigned long count, int flags)
6682{
6683 struct super_block *sb = inode->i_sb;
6684 unsigned int overflow;
6685 struct ext4_sb_info *sbi;
6686
6687 sbi = EXT4_SB(sb);
6688
6689 if (bh) {
6690 if (block)
6691 BUG_ON(block != bh->b_blocknr);
6692 else
6693 block = bh->b_blocknr;
6694 }
6695
6696 if (sbi->s_mount_state & EXT4_FC_REPLAY) {
6697 ext4_free_blocks_simple(inode, block, EXT4_NUM_B2C(sbi, count));
6698 return;
6699 }
6700
6701 might_sleep();
6702
6703 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6704 !ext4_inode_block_valid(inode, start_blk: block, count)) {
6705 ext4_error(sb, "Freeing blocks not in datazone - "
6706 "block = %llu, count = %lu", block, count);
6707 return;
6708 }
6709 flags |= EXT4_FREE_BLOCKS_VALIDATED;
6710
6711 ext4_debug("freeing block %llu\n", block);
6712 trace_ext4_free_blocks(inode, block, count, flags);
6713
6714 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
6715 BUG_ON(count > 1);
6716
6717 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
6718 inode, bh, block);
6719 }
6720
6721 /*
6722 * If the extent to be freed does not begin on a cluster
6723 * boundary, we need to deal with partial clusters at the
6724 * beginning and end of the extent. Normally we will free
6725 * blocks at the beginning or the end unless we are explicitly
6726 * requested to avoid doing so.
6727 */
6728 overflow = EXT4_PBLK_COFF(sbi, block);
6729 if (overflow) {
6730 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
6731 overflow = sbi->s_cluster_ratio - overflow;
6732 block += overflow;
6733 if (count > overflow)
6734 count -= overflow;
6735 else
6736 return;
6737 } else {
6738 block -= overflow;
6739 count += overflow;
6740 }
6741 /* The range changed so it's no longer validated */
6742 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6743 }
6744 overflow = EXT4_LBLK_COFF(sbi, count);
6745 if (overflow) {
6746 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
6747 if (count > overflow)
6748 count -= overflow;
6749 else
6750 return;
6751 } else
6752 count += sbi->s_cluster_ratio - overflow;
6753 /* The range changed so it's no longer validated */
6754 flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6755 }
6756
6757 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
6758 int i;
6759 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
6760
6761 for (i = 0; i < count; i++) {
6762 cond_resched();
6763 if (is_metadata)
6764 bh = sb_find_get_block_nonatomic(sb: inode->i_sb,
6765 block: block + i);
6766 ext4_forget(handle, is_metadata, inode, bh, block + i);
6767 }
6768 }
6769
6770 ext4_mb_clear_bb(handle, inode, block, count, flags);
6771}
6772
6773/**
6774 * ext4_group_add_blocks() -- Add given blocks to an existing group
6775 * @handle: handle to this transaction
6776 * @sb: super block
6777 * @block: start physical block to add to the block group
6778 * @count: number of blocks to free
6779 *
6780 * This marks the blocks as free in the bitmap and buddy.
6781 */
6782int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
6783 ext4_fsblk_t block, unsigned long count)
6784{
6785 ext4_group_t block_group;
6786 ext4_grpblk_t bit;
6787 struct ext4_sb_info *sbi = EXT4_SB(sb);
6788 struct ext4_buddy e4b;
6789 int err = 0;
6790 ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
6791 ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
6792 unsigned long cluster_count = last_cluster - first_cluster + 1;
6793 ext4_grpblk_t changed;
6794
6795 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
6796
6797 if (cluster_count == 0)
6798 return 0;
6799
6800 ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &block_group, offsetp: &bit);
6801 /*
6802 * Check to see if we are freeing blocks across a group
6803 * boundary.
6804 */
6805 if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
6806 ext4_warning(sb, "too many blocks added to group %u",
6807 block_group);
6808 err = -EINVAL;
6809 goto error_out;
6810 }
6811
6812 err = ext4_mb_load_buddy(sb, group: block_group, e4b: &e4b);
6813 if (err)
6814 goto error_out;
6815
6816 if (!ext4_sb_block_valid(sb, NULL, start_blk: block, count)) {
6817 ext4_error(sb, "Adding blocks in system zones - "
6818 "Block = %llu, count = %lu",
6819 block, count);
6820 err = -EINVAL;
6821 goto error_clean;
6822 }
6823
6824 err = ext4_mb_mark_context(handle, sb, state: false, group: block_group, blkoff: bit,
6825 len: cluster_count, EXT4_MB_BITMAP_MARKED_CHECK,
6826 ret_changed: &changed);
6827 if (err && changed == 0)
6828 goto error_clean;
6829
6830 if (changed != cluster_count)
6831 ext4_error(sb, "bit already cleared in group %u", block_group);
6832
6833 ext4_lock_group(sb, group: block_group);
6834 mb_free_blocks(NULL, e4b: &e4b, first: bit, count: cluster_count);
6835 ext4_unlock_group(sb, group: block_group);
6836 percpu_counter_add(fbc: &sbi->s_freeclusters_counter,
6837 amount: changed);
6838
6839error_clean:
6840 ext4_mb_unload_buddy(e4b: &e4b);
6841error_out:
6842 ext4_std_error(sb, err);
6843 return err;
6844}
6845
6846/**
6847 * ext4_trim_extent -- function to TRIM one single free extent in the group
6848 * @sb: super block for the file system
6849 * @start: starting block of the free extent in the alloc. group
6850 * @count: number of blocks to TRIM
6851 * @e4b: ext4 buddy for the group
6852 *
6853 * Trim "count" blocks starting at "start" in the "group". To assure that no
6854 * one will allocate those blocks, mark it as used in buddy bitmap. This must
6855 * be called with under the group lock.
6856 */
6857static int ext4_trim_extent(struct super_block *sb,
6858 int start, int count, struct ext4_buddy *e4b)
6859__releases(bitlock)
6860__acquires(bitlock)
6861{
6862 struct ext4_free_extent ex;
6863 ext4_group_t group = e4b->bd_group;
6864 int ret = 0;
6865
6866 trace_ext4_trim_extent(sb, group, start, len: count);
6867
6868 assert_spin_locked(ext4_group_lock_ptr(sb, group));
6869
6870 ex.fe_start = start;
6871 ex.fe_group = group;
6872 ex.fe_len = count;
6873
6874 /*
6875 * Mark blocks used, so no one can reuse them while
6876 * being trimmed.
6877 */
6878 mb_mark_used(e4b, ex: &ex);
6879 ext4_unlock_group(sb, group);
6880 ret = ext4_issue_discard(sb, block_group: group, cluster: start, count);
6881 ext4_lock_group(sb, group);
6882 mb_free_blocks(NULL, e4b, first: start, count: ex.fe_len);
6883 return ret;
6884}
6885
6886static ext4_grpblk_t ext4_last_grp_cluster(struct super_block *sb,
6887 ext4_group_t grp)
6888{
6889 unsigned long nr_clusters_in_group;
6890
6891 if (grp < (ext4_get_groups_count(sb) - 1))
6892 nr_clusters_in_group = EXT4_CLUSTERS_PER_GROUP(sb);
6893 else
6894 nr_clusters_in_group = (ext4_blocks_count(es: EXT4_SB(sb)->s_es) -
6895 ext4_group_first_block_no(sb, group_no: grp))
6896 >> EXT4_CLUSTER_BITS(sb);
6897
6898 return nr_clusters_in_group - 1;
6899}
6900
6901static bool ext4_trim_interrupted(void)
6902{
6903 return fatal_signal_pending(current) || freezing(current);
6904}
6905
6906static int ext4_try_to_trim_range(struct super_block *sb,
6907 struct ext4_buddy *e4b, ext4_grpblk_t start,
6908 ext4_grpblk_t max, ext4_grpblk_t minblocks)
6909__acquires(ext4_group_lock_ptr(sb, e4b->bd_group))
6910__releases(ext4_group_lock_ptr(sb, e4b->bd_group))
6911{
6912 ext4_grpblk_t next, count, free_count, last, origin_start;
6913 bool set_trimmed = false;
6914 void *bitmap;
6915
6916 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
6917 return 0;
6918
6919 last = ext4_last_grp_cluster(sb, grp: e4b->bd_group);
6920 bitmap = e4b->bd_bitmap;
6921 if (start == 0 && max >= last)
6922 set_trimmed = true;
6923 origin_start = start;
6924 start = max(e4b->bd_info->bb_first_free, start);
6925 count = 0;
6926 free_count = 0;
6927
6928 while (start <= max) {
6929 start = mb_find_next_zero_bit(addr: bitmap, max: max + 1, start);
6930 if (start > max)
6931 break;
6932
6933 next = mb_find_next_bit(addr: bitmap, max: last + 1, start);
6934 if (origin_start == 0 && next >= last)
6935 set_trimmed = true;
6936
6937 if ((next - start) >= minblocks) {
6938 int ret = ext4_trim_extent(sb, start, count: next - start, e4b);
6939
6940 if (ret && ret != -EOPNOTSUPP)
6941 return count;
6942 count += next - start;
6943 }
6944 free_count += next - start;
6945 start = next + 1;
6946
6947 if (ext4_trim_interrupted())
6948 return count;
6949
6950 if (need_resched()) {
6951 ext4_unlock_group(sb, group: e4b->bd_group);
6952 cond_resched();
6953 ext4_lock_group(sb, group: e4b->bd_group);
6954 }
6955
6956 if ((e4b->bd_info->bb_free - free_count) < minblocks)
6957 break;
6958 }
6959
6960 if (set_trimmed)
6961 EXT4_MB_GRP_SET_TRIMMED(e4b->bd_info);
6962
6963 return count;
6964}
6965
6966/**
6967 * ext4_trim_all_free -- function to trim all free space in alloc. group
6968 * @sb: super block for file system
6969 * @group: group to be trimmed
6970 * @start: first group block to examine
6971 * @max: last group block to examine
6972 * @minblocks: minimum extent block count
6973 *
6974 * ext4_trim_all_free walks through group's block bitmap searching for free
6975 * extents. When the free extent is found, mark it as used in group buddy
6976 * bitmap. Then issue a TRIM command on this extent and free the extent in
6977 * the group buddy bitmap.
6978 */
6979static ext4_grpblk_t
6980ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
6981 ext4_grpblk_t start, ext4_grpblk_t max,
6982 ext4_grpblk_t minblocks)
6983{
6984 struct ext4_buddy e4b;
6985 int ret;
6986
6987 trace_ext4_trim_all_free(sb, group, start, len: max);
6988
6989 ret = ext4_mb_load_buddy(sb, group, e4b: &e4b);
6990 if (ret) {
6991 ext4_warning(sb, "Error %d loading buddy information for %u",
6992 ret, group);
6993 return ret;
6994 }
6995
6996 ext4_lock_group(sb, group);
6997
6998 if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) ||
6999 minblocks < EXT4_SB(sb)->s_last_trim_minblks)
7000 ret = ext4_try_to_trim_range(sb, e4b: &e4b, start, max, minblocks);
7001 else
7002 ret = 0;
7003
7004 ext4_unlock_group(sb, group);
7005 ext4_mb_unload_buddy(e4b: &e4b);
7006
7007 ext4_debug("trimmed %d blocks in the group %d\n",
7008 ret, group);
7009
7010 return ret;
7011}
7012
7013/**
7014 * ext4_trim_fs() -- trim ioctl handle function
7015 * @sb: superblock for filesystem
7016 * @range: fstrim_range structure
7017 *
7018 * start: First Byte to trim
7019 * len: number of Bytes to trim from start
7020 * minlen: minimum extent length in Bytes
7021 * ext4_trim_fs goes through all allocation groups containing Bytes from
7022 * start to start+len. For each such a group ext4_trim_all_free function
7023 * is invoked to trim all free space.
7024 */
7025int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
7026{
7027 unsigned int discard_granularity = bdev_discard_granularity(bdev: sb->s_bdev);
7028 struct ext4_group_info *grp;
7029 ext4_group_t group, first_group, last_group;
7030 ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
7031 uint64_t start, end, minlen, trimmed = 0;
7032 ext4_fsblk_t first_data_blk =
7033 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
7034 ext4_fsblk_t max_blks = ext4_blocks_count(es: EXT4_SB(sb)->s_es);
7035 int ret = 0;
7036
7037 start = range->start >> sb->s_blocksize_bits;
7038 end = start + (range->len >> sb->s_blocksize_bits) - 1;
7039 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
7040 range->minlen >> sb->s_blocksize_bits);
7041
7042 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
7043 start >= max_blks ||
7044 range->len < sb->s_blocksize)
7045 return -EINVAL;
7046 /* No point to try to trim less than discard granularity */
7047 if (range->minlen < discard_granularity) {
7048 minlen = EXT4_NUM_B2C(EXT4_SB(sb),
7049 discard_granularity >> sb->s_blocksize_bits);
7050 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb))
7051 goto out;
7052 }
7053 if (end >= max_blks - 1)
7054 end = max_blks - 1;
7055 if (end <= first_data_blk)
7056 goto out;
7057 if (start < first_data_blk)
7058 start = first_data_blk;
7059
7060 /* Determine first and last group to examine based on start and end */
7061 ext4_get_group_no_and_offset(sb, blocknr: (ext4_fsblk_t) start,
7062 blockgrpp: &first_group, offsetp: &first_cluster);
7063 ext4_get_group_no_and_offset(sb, blocknr: (ext4_fsblk_t) end,
7064 blockgrpp: &last_group, offsetp: &last_cluster);
7065
7066 /* end now represents the last cluster to discard in this group */
7067 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
7068
7069 for (group = first_group; group <= last_group; group++) {
7070 if (ext4_trim_interrupted())
7071 break;
7072 grp = ext4_get_group_info(sb, group);
7073 if (!grp)
7074 continue;
7075 /* We only do this if the grp has never been initialized */
7076 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
7077 ret = ext4_mb_init_group(sb, group, GFP_NOFS);
7078 if (ret)
7079 break;
7080 }
7081
7082 /*
7083 * For all the groups except the last one, last cluster will
7084 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
7085 * change it for the last group, note that last_cluster is
7086 * already computed earlier by ext4_get_group_no_and_offset()
7087 */
7088 if (group == last_group)
7089 end = last_cluster;
7090 if (grp->bb_free >= minlen) {
7091 cnt = ext4_trim_all_free(sb, group, start: first_cluster,
7092 max: end, minblocks: minlen);
7093 if (cnt < 0) {
7094 ret = cnt;
7095 break;
7096 }
7097 trimmed += cnt;
7098 }
7099
7100 /*
7101 * For every group except the first one, we are sure
7102 * that the first cluster to discard will be cluster #0.
7103 */
7104 first_cluster = 0;
7105 }
7106
7107 if (!ret)
7108 EXT4_SB(sb)->s_last_trim_minblks = minlen;
7109
7110out:
7111 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
7112 return ret;
7113}
7114
7115/* Iterate all the free extents in the group. */
7116int
7117ext4_mballoc_query_range(
7118 struct super_block *sb,
7119 ext4_group_t group,
7120 ext4_grpblk_t first,
7121 ext4_grpblk_t end,
7122 ext4_mballoc_query_range_fn meta_formatter,
7123 ext4_mballoc_query_range_fn formatter,
7124 void *priv)
7125{
7126 void *bitmap;
7127 ext4_grpblk_t start, next;
7128 struct ext4_buddy e4b;
7129 int error;
7130
7131 error = ext4_mb_load_buddy(sb, group, e4b: &e4b);
7132 if (error)
7133 return error;
7134 bitmap = e4b.bd_bitmap;
7135
7136 ext4_lock_group(sb, group);
7137
7138 start = max(e4b.bd_info->bb_first_free, first);
7139 if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
7140 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
7141 if (meta_formatter && start != first) {
7142 if (start > end)
7143 start = end;
7144 ext4_unlock_group(sb, group);
7145 error = meta_formatter(sb, group, first, start - first,
7146 priv);
7147 if (error)
7148 goto out_unload;
7149 ext4_lock_group(sb, group);
7150 }
7151 while (start <= end) {
7152 start = mb_find_next_zero_bit(addr: bitmap, max: end + 1, start);
7153 if (start > end)
7154 break;
7155 next = mb_find_next_bit(addr: bitmap, max: end + 1, start);
7156
7157 ext4_unlock_group(sb, group);
7158 error = formatter(sb, group, start, next - start, priv);
7159 if (error)
7160 goto out_unload;
7161 ext4_lock_group(sb, group);
7162
7163 start = next + 1;
7164 }
7165
7166 ext4_unlock_group(sb, group);
7167out_unload:
7168 ext4_mb_unload_buddy(e4b: &e4b);
7169
7170 return error;
7171}
7172
7173#ifdef CONFIG_EXT4_KUNIT_TESTS
7174#include "mballoc-test.c"
7175#endif
7176