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mballoc.c
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linux-6.19.14/fs/ext4/mballoc.c
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 * { folio } 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 folio can contain blocks_per_folio (folio_size / 107 * blocksize) blocks. So it can have information regarding groups_per_folio 108 * which is blocks_per_folio/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, addr); 485 return ext4_test_bit(bit, addr); 486} 487 488static inline void mb_set_bit(int bit, void *addr) 489{ 490 addr = mb_correct_addr_and_bit(&bit, addr); 491 ext4_set_bit(bit, addr); 492} 493 494static inline void mb_clear_bit(int bit, void *addr) 495{ 496 addr = mb_correct_addr_and_bit(&bit, addr); 497 ext4_clear_bit(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, addr); 503 return ext4_test_and_clear_bit(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(&fix, addr); 510 tmpmax = max + fix; 511 start += fix; 512 513 ret = ext4_find_next_zero_bit(addr, tmpmax, 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(&fix, addr); 523 tmpmax = max + fix; 524 start += fix; 525 526 ret = ext4_find_next_bit(addr, tmpmax, 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(e4b->bd_sb)->s_mb_offsets[order]; 551 *max = EXT4_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) 684 685/* 686 * Perform buddy integrity check with the following steps: 687 * 688 * 1. Top-down validation (from highest order down to order 1, excluding order-0 bitmap): 689 * For each pair of adjacent orders, if a higher-order bit is set (indicating a free block), 690 * at most one of the two corresponding lower-order bits may be clear (free). 691 * 692 * 2. Order-0 (bitmap) validation, performed on bit pairs: 693 * - If either bit in a pair is set (1, allocated), then all corresponding higher-order bits 694 * must not be free (0). 695 * - If both bits in a pair are clear (0, free), then exactly one of the corresponding 696 * higher-order bits must be free (0). 697 * 698 * 3. Preallocation (pa) list validation: 699 * For each preallocated block (pa) in the group: 700 * - Verify that pa_pstart falls within the bounds of this block group. 701 * - Ensure the corresponding bit(s) in the order-0 bitmap are marked as allocated (1). 702 */ 703static void __mb_check_buddy(struct ext4_buddy *e4b, char *file, 704 const char *function, int line) 705{ 706 struct super_block *sb = e4b->bd_sb; 707 int order = e4b->bd_blkbits + 1; 708 int max; 709 int max2; 710 int i; 711 int j; 712 int k; 713 int count; 714 struct ext4_group_info *grp; 715 int fragments = 0; 716 int fstart; 717 struct list_head *cur; 718 void *buddy; 719 void *buddy2; 720 721 if (e4b->bd_info->bb_check_counter++ % 10) 722 return; 723 724 while (order > 1) { 725 buddy = mb_find_buddy(e4b, order, &max); 726 MB_CHECK_ASSERT(buddy); 727 buddy2 = mb_find_buddy(e4b, order - 1, &max2); 728 MB_CHECK_ASSERT(buddy2); 729 MB_CHECK_ASSERT(buddy != buddy2); 730 MB_CHECK_ASSERT(max * 2 == max2); 731 732 count = 0; 733 for (i = 0; i < max; i++) { 734 735 if (mb_test_bit(i, buddy)) { 736 /* only single bit in buddy2 may be 0 */ 737 if (!mb_test_bit(i << 1, buddy2)) { 738 MB_CHECK_ASSERT( 739 mb_test_bit((i<<1)+1, buddy2)); 740 } 741 continue; 742 } 743 744 count++; 745 } 746 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count); 747 order--; 748 } 749 750 fstart = -1; 751 buddy = mb_find_buddy(e4b, 0, &max); 752 for (i = 0; i < max; i++) { 753 if (!mb_test_bit(i, buddy)) { 754 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); 755 if (fstart == -1) { 756 fragments++; 757 fstart = i; 758 } 759 } else { 760 fstart = -1; 761 } 762 if (!(i & 1)) { 763 int in_use, zero_bit_count = 0; 764 765 in_use = mb_test_bit(i, buddy) || mb_test_bit(i + 1, buddy); 766 for (j = 1; j < e4b->bd_blkbits + 2; j++) { 767 buddy2 = mb_find_buddy(e4b, j, &max2); 768 k = i >> j; 769 MB_CHECK_ASSERT(k < max2); 770 if (!mb_test_bit(k, buddy2)) 771 zero_bit_count++; 772 } 773 MB_CHECK_ASSERT(zero_bit_count == !in_use); 774 } 775 } 776 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); 777 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); 778 779 grp = ext4_get_group_info(sb, e4b->bd_group); 780 if (!grp) 781 return; 782 list_for_each(cur, &grp->bb_prealloc_list) { 783 ext4_group_t groupnr; 784 struct ext4_prealloc_space *pa; 785 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); 786 if (!pa->pa_len) 787 continue; 788 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k); 789 MB_CHECK_ASSERT(groupnr == e4b->bd_group); 790 for (i = 0; i < pa->pa_len; i++) 791 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy)); 792 } 793} 794#undef MB_CHECK_ASSERT 795#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \ 796 __FILE__, __func__, __LINE__) 797#else 798#define mb_check_buddy(e4b) 799#endif 800 801/* 802 * Divide blocks started from @first with length @len into 803 * smaller chunks with power of 2 blocks. 804 * Clear the bits in bitmap which the blocks of the chunk(s) covered, 805 * then increase bb_counters[] for corresponded chunk size. 806 */ 807static void ext4_mb_mark_free_simple(struct super_block *sb, 808 void *buddy, ext4_grpblk_t first, ext4_grpblk_t len, 809 struct ext4_group_info *grp) 810{ 811 struct ext4_sb_info *sbi = EXT4_SB(sb); 812 ext4_grpblk_t min; 813 ext4_grpblk_t max; 814 ext4_grpblk_t chunk; 815 unsigned int border; 816 817 BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb)); 818 819 border = 2 << sb->s_blocksize_bits; 820 821 while (len > 0) { 822 /* find how many blocks can be covered since this position */ 823 max = ffs(first | border) - 1; 824 825 /* find how many blocks of power 2 we need to mark */ 826 min = fls(len) - 1; 827 828 if (max < min) 829 min = max; 830 chunk = 1 << min; 831 832 /* mark multiblock chunks only */ 833 grp->bb_counters[min]++; 834 if (min > 0) 835 mb_clear_bit(first >> min, 836 buddy + sbi->s_mb_offsets[min]); 837 838 len -= chunk; 839 first += chunk; 840 } 841} 842 843static int mb_avg_fragment_size_order(struct super_block *sb, ext4_grpblk_t len) 844{ 845 int order; 846 847 /* 848 * We don't bother with a special lists groups with only 1 block free 849 * extents and for completely empty groups. 850 */ 851 order = fls(len) - 2; 852 if (order < 0) 853 return 0; 854 if (order == MB_NUM_ORDERS(sb)) 855 order--; 856 if (WARN_ON_ONCE(order > MB_NUM_ORDERS(sb))) 857 order = MB_NUM_ORDERS(sb) - 1; 858 return order; 859} 860 861/* Move group to appropriate avg_fragment_size list */ 862static void 863mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp) 864{ 865 struct ext4_sb_info *sbi = EXT4_SB(sb); 866 int new, old; 867 868 if (!test_opt2(sb, MB_OPTIMIZE_SCAN)) 869 return; 870 871 old = grp->bb_avg_fragment_size_order; 872 new = grp->bb_fragments == 0 ? -1 : 873 mb_avg_fragment_size_order(sb, grp->bb_free / grp->bb_fragments); 874 if (new == old) 875 return; 876 877 if (old >= 0) 878 xa_erase(&sbi->s_mb_avg_fragment_size[old], grp->bb_group); 879 880 grp->bb_avg_fragment_size_order = new; 881 if (new >= 0) { 882 /* 883 * Cannot use __GFP_NOFAIL because we hold the group lock. 884 * Although allocation for insertion may fails, it's not fatal 885 * as we have linear traversal to fall back on. 886 */ 887 int err = xa_insert(&sbi->s_mb_avg_fragment_size[new], 888 grp->bb_group, grp, GFP_ATOMIC); 889 if (err) 890 mb_debug(sb, "insert group: %u to s_mb_avg_fragment_size[%d] failed, err %d", 891 grp->bb_group, new, err); 892 } 893} 894 895static ext4_group_t ext4_get_allocation_groups_count( 896 struct ext4_allocation_context *ac) 897{ 898 ext4_group_t ngroups = ext4_get_groups_count(ac->ac_sb); 899 900 /* non-extent files are limited to low blocks/groups */ 901 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))) 902 ngroups = EXT4_SB(ac->ac_sb)->s_blockfile_groups; 903 904 /* Pairs with smp_wmb() in ext4_update_super() */ 905 smp_rmb(); 906 907 return ngroups; 908} 909 910static int ext4_mb_scan_groups_xa_range(struct ext4_allocation_context *ac, 911 struct xarray *xa, 912 ext4_group_t start, ext4_group_t end) 913{ 914 struct super_block *sb = ac->ac_sb; 915 struct ext4_sb_info *sbi = EXT4_SB(sb); 916 enum criteria cr = ac->ac_criteria; 917 ext4_group_t ngroups = ext4_get_allocation_groups_count(ac); 918 unsigned long group = start; 919 struct ext4_group_info *grp; 920 921 if (WARN_ON_ONCE(end > ngroups || start >= end)) 922 return 0; 923 924 xa_for_each_range(xa, group, grp, start, end - 1) { 925 int err; 926 927 if (sbi->s_mb_stats) 928 atomic64_inc(&sbi->s_bal_cX_groups_considered[cr]); 929 930 err = ext4_mb_scan_group(ac, grp->bb_group); 931 if (err || ac->ac_status != AC_STATUS_CONTINUE) 932 return err; 933 934 cond_resched(); 935 } 936 937 return 0; 938} 939 940/* 941 * Find a suitable group of given order from the largest free orders xarray. 942 */ 943static inline int 944ext4_mb_scan_groups_largest_free_order_range(struct ext4_allocation_context *ac, 945 int order, ext4_group_t start, 946 ext4_group_t end) 947{ 948 struct xarray *xa = &EXT4_SB(ac->ac_sb)->s_mb_largest_free_orders[order]; 949 950 if (xa_empty(xa)) 951 return 0; 952 953 return ext4_mb_scan_groups_xa_range(ac, xa, start, end); 954} 955 956/* 957 * Choose next group by traversing largest_free_order lists. Updates *new_cr if 958 * cr level needs an update. 959 */ 960static int ext4_mb_scan_groups_p2_aligned(struct ext4_allocation_context *ac, 961 ext4_group_t group) 962{ 963 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 964 int i; 965 int ret = 0; 966 ext4_group_t start, end; 967 968 start = group; 969 end = ext4_get_allocation_groups_count(ac); 970wrap_around: 971 for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) { 972 ret = ext4_mb_scan_groups_largest_free_order_range(ac, i, 973 start, end); 974 if (ret || ac->ac_status != AC_STATUS_CONTINUE) 975 return ret; 976 } 977 if (start) { 978 end = start; 979 start = 0; 980 goto wrap_around; 981 } 982 983 if (sbi->s_mb_stats) 984 atomic64_inc(&sbi->s_bal_cX_failed[ac->ac_criteria]); 985 986 /* Increment cr and search again if no group is found */ 987 ac->ac_criteria = CR_GOAL_LEN_FAST; 988 return ret; 989} 990 991/* 992 * Find a suitable group of given order from the average fragments xarray. 993 */ 994static int 995ext4_mb_scan_groups_avg_frag_order_range(struct ext4_allocation_context *ac, 996 int order, ext4_group_t start, 997 ext4_group_t end) 998{ 999 struct xarray *xa = &EXT4_SB(ac->ac_sb)->s_mb_avg_fragment_size[order]; 1000 1001 if (xa_empty(xa)) 1002 return 0; 1003 1004 return ext4_mb_scan_groups_xa_range(ac, xa, start, end); 1005} 1006 1007/* 1008 * Choose next group by traversing average fragment size list of suitable 1009 * order. Updates *new_cr if cr level needs an update. 1010 */ 1011static int ext4_mb_scan_groups_goal_fast(struct ext4_allocation_context *ac, 1012 ext4_group_t group) 1013{ 1014 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 1015 int i, ret = 0; 1016 ext4_group_t start, end; 1017 1018 start = group; 1019 end = ext4_get_allocation_groups_count(ac); 1020wrap_around: 1021 i = mb_avg_fragment_size_order(ac->ac_sb, ac->ac_g_ex.fe_len); 1022 for (; i < MB_NUM_ORDERS(ac->ac_sb); i++) { 1023 ret = ext4_mb_scan_groups_avg_frag_order_range(ac, i, 1024 start, end); 1025 if (ret || ac->ac_status != AC_STATUS_CONTINUE) 1026 return ret; 1027 } 1028 if (start) { 1029 end = start; 1030 start = 0; 1031 goto wrap_around; 1032 } 1033 1034 if (sbi->s_mb_stats) 1035 atomic64_inc(&sbi->s_bal_cX_failed[ac->ac_criteria]); 1036 /* 1037 * CR_BEST_AVAIL_LEN works based on the concept that we have 1038 * a larger normalized goal len request which can be trimmed to 1039 * a smaller goal len such that it can still satisfy original 1040 * request len. However, allocation request for non-regular 1041 * files never gets normalized. 1042 * See function ext4_mb_normalize_request() (EXT4_MB_HINT_DATA). 1043 */ 1044 if (ac->ac_flags & EXT4_MB_HINT_DATA) 1045 ac->ac_criteria = CR_BEST_AVAIL_LEN; 1046 else 1047 ac->ac_criteria = CR_GOAL_LEN_SLOW; 1048 1049 return ret; 1050} 1051 1052/* 1053 * We couldn't find a group in CR_GOAL_LEN_FAST so try to find the highest free fragment 1054 * order we have and proactively trim the goal request length to that order to 1055 * find a suitable group faster. 1056 * 1057 * This optimizes allocation speed at the cost of slightly reduced 1058 * preallocations. However, we make sure that we don't trim the request too 1059 * much and fall to CR_GOAL_LEN_SLOW in that case. 1060 */ 1061static int ext4_mb_scan_groups_best_avail(struct ext4_allocation_context *ac, 1062 ext4_group_t group) 1063{ 1064 int ret = 0; 1065 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 1066 int i, order, min_order; 1067 unsigned long num_stripe_clusters = 0; 1068 ext4_group_t start, end; 1069 1070 /* 1071 * mb_avg_fragment_size_order() returns order in a way that makes 1072 * retrieving back the length using (1 << order) inaccurate. Hence, use 1073 * fls() instead since we need to know the actual length while modifying 1074 * goal length. 1075 */ 1076 order = fls(ac->ac_g_ex.fe_len) - 1; 1077 if (WARN_ON_ONCE(order - 1 > MB_NUM_ORDERS(ac->ac_sb))) 1078 order = MB_NUM_ORDERS(ac->ac_sb); 1079 min_order = order - sbi->s_mb_best_avail_max_trim_order; 1080 if (min_order < 0) 1081 min_order = 0; 1082 1083 if (sbi->s_stripe > 0) { 1084 /* 1085 * We are assuming that stripe size is always a multiple of 1086 * cluster ratio otherwise __ext4_fill_super exists early. 1087 */ 1088 num_stripe_clusters = EXT4_NUM_B2C(sbi, sbi->s_stripe); 1089 if (1 << min_order < num_stripe_clusters) 1090 /* 1091 * We consider 1 order less because later we round 1092 * up the goal len to num_stripe_clusters 1093 */ 1094 min_order = fls(num_stripe_clusters) - 1; 1095 } 1096 1097 if (1 << min_order < ac->ac_o_ex.fe_len) 1098 min_order = fls(ac->ac_o_ex.fe_len); 1099 1100 start = group; 1101 end = ext4_get_allocation_groups_count(ac); 1102wrap_around: 1103 for (i = order; i >= min_order; i--) { 1104 int frag_order; 1105 /* 1106 * Scale down goal len to make sure we find something 1107 * in the free fragments list. Basically, reduce 1108 * preallocations. 1109 */ 1110 ac->ac_g_ex.fe_len = 1 << i; 1111 1112 if (num_stripe_clusters > 0) { 1113 /* 1114 * Try to round up the adjusted goal length to 1115 * stripe size (in cluster units) multiple for 1116 * efficiency. 1117 */ 1118 ac->ac_g_ex.fe_len = roundup(ac->ac_g_ex.fe_len, 1119 num_stripe_clusters); 1120 } 1121 1122 frag_order = mb_avg_fragment_size_order(ac->ac_sb, 1123 ac->ac_g_ex.fe_len); 1124 1125 ret = ext4_mb_scan_groups_avg_frag_order_range(ac, frag_order, 1126 start, end); 1127 if (ret || ac->ac_status != AC_STATUS_CONTINUE) 1128 return ret; 1129 } 1130 if (start) { 1131 end = start; 1132 start = 0; 1133 goto wrap_around; 1134 } 1135 1136 /* Reset goal length to original goal length before falling into CR_GOAL_LEN_SLOW */ 1137 ac->ac_g_ex.fe_len = ac->ac_orig_goal_len; 1138 if (sbi->s_mb_stats) 1139 atomic64_inc(&sbi->s_bal_cX_failed[ac->ac_criteria]); 1140 ac->ac_criteria = CR_GOAL_LEN_SLOW; 1141 1142 return ret; 1143} 1144 1145static inline int should_optimize_scan(struct ext4_allocation_context *ac) 1146{ 1147 if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN))) 1148 return 0; 1149 if (ac->ac_criteria >= CR_GOAL_LEN_SLOW) 1150 return 0; 1151 return 1; 1152} 1153 1154/* 1155 * next linear group for allocation. 1156 */ 1157static void next_linear_group(ext4_group_t *group, ext4_group_t ngroups) 1158{ 1159 /* 1160 * Artificially restricted ngroups for non-extent 1161 * files makes group > ngroups possible on first loop. 1162 */ 1163 *group = *group + 1 >= ngroups ? 0 : *group + 1; 1164} 1165 1166static int ext4_mb_scan_groups_linear(struct ext4_allocation_context *ac, 1167 ext4_group_t ngroups, ext4_group_t *start, ext4_group_t count) 1168{ 1169 int ret, i; 1170 enum criteria cr = ac->ac_criteria; 1171 struct super_block *sb = ac->ac_sb; 1172 struct ext4_sb_info *sbi = EXT4_SB(sb); 1173 ext4_group_t group = *start; 1174 1175 for (i = 0; i < count; i++, next_linear_group(&group, ngroups)) { 1176 ret = ext4_mb_scan_group(ac, group); 1177 if (ret || ac->ac_status != AC_STATUS_CONTINUE) 1178 return ret; 1179 cond_resched(); 1180 } 1181 1182 *start = group; 1183 if (count == ngroups) 1184 ac->ac_criteria++; 1185 1186 /* Processed all groups and haven't found blocks */ 1187 if (sbi->s_mb_stats && i == ngroups) 1188 atomic64_inc(&sbi->s_bal_cX_failed[cr]); 1189 1190 return 0; 1191} 1192 1193static int ext4_mb_scan_groups(struct ext4_allocation_context *ac) 1194{ 1195 int ret = 0; 1196 ext4_group_t start; 1197 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 1198 ext4_group_t ngroups = ext4_get_allocation_groups_count(ac); 1199 1200 /* searching for the right group start from the goal value specified */ 1201 start = ac->ac_g_ex.fe_group; 1202 if (start >= ngroups) 1203 start = 0; 1204 ac->ac_prefetch_grp = start; 1205 ac->ac_prefetch_nr = 0; 1206 1207 if (!should_optimize_scan(ac)) 1208 return ext4_mb_scan_groups_linear(ac, ngroups, &start, ngroups); 1209 1210 /* 1211 * Optimized scanning can return non adjacent groups which can cause 1212 * seek overhead for rotational disks. So try few linear groups before 1213 * trying optimized scan. 1214 */ 1215 if (sbi->s_mb_max_linear_groups) 1216 ret = ext4_mb_scan_groups_linear(ac, ngroups, &start, 1217 sbi->s_mb_max_linear_groups); 1218 if (ret || ac->ac_status != AC_STATUS_CONTINUE) 1219 return ret; 1220 1221 switch (ac->ac_criteria) { 1222 case CR_POWER2_ALIGNED: 1223 return ext4_mb_scan_groups_p2_aligned(ac, start); 1224 case CR_GOAL_LEN_FAST: 1225 return ext4_mb_scan_groups_goal_fast(ac, start); 1226 case CR_BEST_AVAIL_LEN: 1227 return ext4_mb_scan_groups_best_avail(ac, start); 1228 default: 1229 /* 1230 * TODO: For CR_GOAL_LEN_SLOW, we can arrange groups in an 1231 * rb tree sorted by bb_free. But until that happens, we should 1232 * never come here. 1233 */ 1234 WARN_ON(1); 1235 } 1236 1237 return 0; 1238} 1239 1240/* 1241 * Cache the order of the largest free extent we have available in this block 1242 * group. 1243 */ 1244static void 1245mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp) 1246{ 1247 struct ext4_sb_info *sbi = EXT4_SB(sb); 1248 int new, old = grp->bb_largest_free_order; 1249 1250 for (new = MB_NUM_ORDERS(sb) - 1; new >= 0; new--) 1251 if (grp->bb_counters[new] > 0) 1252 break; 1253 1254 /* No need to move between order lists? */ 1255 if (new == old) 1256 return; 1257 1258 if (old >= 0) { 1259 struct xarray *xa = &sbi->s_mb_largest_free_orders[old]; 1260 1261 if (!xa_empty(xa) && xa_load(xa, grp->bb_group)) 1262 xa_erase(xa, grp->bb_group); 1263 } 1264 1265 grp->bb_largest_free_order = new; 1266 if (test_opt2(sb, MB_OPTIMIZE_SCAN) && new >= 0 && grp->bb_free) { 1267 /* 1268 * Cannot use __GFP_NOFAIL because we hold the group lock. 1269 * Although allocation for insertion may fails, it's not fatal 1270 * as we have linear traversal to fall back on. 1271 */ 1272 int err = xa_insert(&sbi->s_mb_largest_free_orders[new], 1273 grp->bb_group, grp, GFP_ATOMIC); 1274 if (err) 1275 mb_debug(sb, "insert group: %u to s_mb_largest_free_orders[%d] failed, err %d", 1276 grp->bb_group, new, err); 1277 } 1278} 1279 1280static noinline_for_stack 1281void ext4_mb_generate_buddy(struct super_block *sb, 1282 void *buddy, void *bitmap, ext4_group_t group, 1283 struct ext4_group_info *grp) 1284{ 1285 struct ext4_sb_info *sbi = EXT4_SB(sb); 1286 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); 1287 ext4_grpblk_t i = 0; 1288 ext4_grpblk_t first; 1289 ext4_grpblk_t len; 1290 unsigned free = 0; 1291 unsigned fragments = 0; 1292 unsigned long long period = get_cycles(); 1293 1294 /* initialize buddy from bitmap which is aggregation 1295 * of on-disk bitmap and preallocations */ 1296 i = mb_find_next_zero_bit(bitmap, max, 0); 1297 grp->bb_first_free = i; 1298 while (i < max) { 1299 fragments++; 1300 first = i; 1301 i = mb_find_next_bit(bitmap, max, i); 1302 len = i - first; 1303 free += len; 1304 if (len > 1) 1305 ext4_mb_mark_free_simple(sb, buddy, first, len, grp); 1306 else 1307 grp->bb_counters[0]++; 1308 if (i < max) 1309 i = mb_find_next_zero_bit(bitmap, max, i); 1310 } 1311 grp->bb_fragments = fragments; 1312 1313 if (free != grp->bb_free) { 1314 ext4_grp_locked_error(sb, group, 0, 0, 1315 "block bitmap and bg descriptor " 1316 "inconsistent: %u vs %u free clusters", 1317 free, grp->bb_free); 1318 /* 1319 * If we intend to continue, we consider group descriptor 1320 * corrupt and update bb_free using bitmap value 1321 */ 1322 grp->bb_free = free; 1323 ext4_mark_group_bitmap_corrupted(sb, group, 1324 EXT4_GROUP_INFO_BBITMAP_CORRUPT); 1325 } 1326 mb_set_largest_free_order(sb, grp); 1327 mb_update_avg_fragment_size(sb, grp); 1328 1329 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); 1330 1331 period = get_cycles() - period; 1332 atomic_inc(&sbi->s_mb_buddies_generated); 1333 atomic64_add(period, &sbi->s_mb_generation_time); 1334} 1335 1336static void mb_regenerate_buddy(struct ext4_buddy *e4b) 1337{ 1338 int count; 1339 int order = 1; 1340 void *buddy; 1341 1342 while ((buddy = mb_find_buddy(e4b, order++, &count))) 1343 mb_set_bits(buddy, 0, count); 1344 1345 e4b->bd_info->bb_fragments = 0; 1346 memset(e4b->bd_info->bb_counters, 0, 1347 sizeof(*e4b->bd_info->bb_counters) * 1348 (e4b->bd_sb->s_blocksize_bits + 2)); 1349 1350 ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy, 1351 e4b->bd_bitmap, e4b->bd_group, e4b->bd_info); 1352} 1353 1354/* The buddy information is attached the buddy cache inode 1355 * for convenience. The information regarding each group 1356 * is loaded via ext4_mb_load_buddy. The information involve 1357 * block bitmap and buddy information. The information are 1358 * stored in the inode as 1359 * 1360 * { folio } 1361 * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... 1362 * 1363 * 1364 * one block each for bitmap and buddy information. 1365 * So for each group we take up 2 blocks. A folio can 1366 * contain blocks_per_folio (folio_size / blocksize) blocks. 1367 * So it can have information regarding groups_per_folio which 1368 * is blocks_per_folio/2 1369 * 1370 * Locking note: This routine takes the block group lock of all groups 1371 * for this folio; do not hold this lock when calling this routine! 1372 */ 1373static int ext4_mb_init_cache(struct folio *folio, char *incore, gfp_t gfp) 1374{ 1375 ext4_group_t ngroups; 1376 unsigned int blocksize; 1377 int blocks_per_folio; 1378 int groups_per_folio; 1379 int err = 0; 1380 int i; 1381 ext4_group_t first_group, group; 1382 int first_block; 1383 struct super_block *sb; 1384 struct buffer_head *bhs; 1385 struct buffer_head **bh = NULL; 1386 struct inode *inode; 1387 char *data; 1388 char *bitmap; 1389 struct ext4_group_info *grinfo; 1390 1391 inode = folio->mapping->host; 1392 sb = inode->i_sb; 1393 ngroups = ext4_get_groups_count(sb); 1394 blocksize = i_blocksize(inode); 1395 blocks_per_folio = folio_size(folio) / blocksize; 1396 WARN_ON_ONCE(!blocks_per_folio); 1397 groups_per_folio = DIV_ROUND_UP(blocks_per_folio, 2); 1398 1399 mb_debug(sb, "init folio %lu\n", folio->index); 1400 1401 /* allocate buffer_heads to read bitmaps */ 1402 if (groups_per_folio > 1) { 1403 i = sizeof(struct buffer_head *) * groups_per_folio; 1404 bh = kzalloc(i, gfp); 1405 if (bh == NULL) 1406 return -ENOMEM; 1407 } else 1408 bh = &bhs; 1409 1410 /* read all groups the folio covers into the cache */ 1411 first_group = EXT4_PG_TO_LBLK(inode, folio->index) / 2; 1412 for (i = 0, group = first_group; i < groups_per_folio; i++, group++) { 1413 if (group >= ngroups) 1414 break; 1415 1416 grinfo = ext4_get_group_info(sb, group); 1417 if (!grinfo) 1418 continue; 1419 /* 1420 * If folio is uptodate then we came here after online resize 1421 * which added some new uninitialized group info structs, so 1422 * we must skip all initialized uptodate buddies on the folio, 1423 * which may be currently in use by an allocating task. 1424 */ 1425 if (folio_test_uptodate(folio) && 1426 !EXT4_MB_GRP_NEED_INIT(grinfo)) { 1427 bh[i] = NULL; 1428 continue; 1429 } 1430 bh[i] = ext4_read_block_bitmap_nowait(sb, group, false); 1431 if (IS_ERR(bh[i])) { 1432 err = PTR_ERR(bh[i]); 1433 bh[i] = NULL; 1434 goto out; 1435 } 1436 mb_debug(sb, "read bitmap for group %u\n", group); 1437 } 1438 1439 /* wait for I/O completion */ 1440 for (i = 0, group = first_group; i < groups_per_folio; i++, group++) { 1441 int err2; 1442 1443 if (!bh[i]) 1444 continue; 1445 err2 = ext4_wait_block_bitmap(sb, group, bh[i]); 1446 if (!err) 1447 err = err2; 1448 } 1449 1450 first_block = EXT4_PG_TO_LBLK(inode, folio->index); 1451 for (i = 0; i < blocks_per_folio; i++) { 1452 group = (first_block + i) >> 1; 1453 if (group >= ngroups) 1454 break; 1455 1456 if (!bh[group - first_group]) 1457 /* skip initialized uptodate buddy */ 1458 continue; 1459 1460 if (!buffer_verified(bh[group - first_group])) 1461 /* Skip faulty bitmaps */ 1462 continue; 1463 err = 0; 1464 1465 /* 1466 * data carry information regarding this 1467 * particular group in the format specified 1468 * above 1469 * 1470 */ 1471 data = folio_address(folio) + (i * blocksize); 1472 bitmap = bh[group - first_group]->b_data; 1473 1474 /* 1475 * We place the buddy block and bitmap block 1476 * close together 1477 */ 1478 grinfo = ext4_get_group_info(sb, group); 1479 if (!grinfo) { 1480 err = -EFSCORRUPTED; 1481 goto out; 1482 } 1483 if ((first_block + i) & 1) { 1484 /* this is block of buddy */ 1485 BUG_ON(incore == NULL); 1486 mb_debug(sb, "put buddy for group %u in folio %lu/%x\n", 1487 group, folio->index, i * blocksize); 1488 trace_ext4_mb_buddy_bitmap_load(sb, group); 1489 grinfo->bb_fragments = 0; 1490 memset(grinfo->bb_counters, 0, 1491 sizeof(*grinfo->bb_counters) * 1492 (MB_NUM_ORDERS(sb))); 1493 /* 1494 * incore got set to the group block bitmap below 1495 */ 1496 ext4_lock_group(sb, group); 1497 /* init the buddy */ 1498 memset(data, 0xff, blocksize); 1499 ext4_mb_generate_buddy(sb, data, incore, group, grinfo); 1500 ext4_unlock_group(sb, group); 1501 incore = NULL; 1502 } else { 1503 /* this is block of bitmap */ 1504 BUG_ON(incore != NULL); 1505 mb_debug(sb, "put bitmap for group %u in folio %lu/%x\n", 1506 group, folio->index, i * blocksize); 1507 trace_ext4_mb_bitmap_load(sb, group); 1508 1509 /* see comments in ext4_mb_put_pa() */ 1510 ext4_lock_group(sb, group); 1511 memcpy(data, bitmap, blocksize); 1512 1513 /* mark all preallocated blks used in in-core bitmap */ 1514 ext4_mb_generate_from_pa(sb, data, group); 1515 WARN_ON_ONCE(!RB_EMPTY_ROOT(&grinfo->bb_free_root)); 1516 ext4_unlock_group(sb, group); 1517 1518 /* set incore so that the buddy information can be 1519 * generated using this 1520 */ 1521 incore = data; 1522 } 1523 } 1524 folio_mark_uptodate(folio); 1525 1526out: 1527 if (bh) { 1528 for (i = 0; i < groups_per_folio; i++) 1529 brelse(bh[i]); 1530 if (bh != &bhs) 1531 kfree(bh); 1532 } 1533 return err; 1534} 1535 1536/* 1537 * Lock the buddy and bitmap folios. This makes sure other parallel init_group 1538 * on the same buddy folio doesn't happen while holding the buddy folio lock. 1539 * Return locked buddy and bitmap folios on e4b struct. If buddy and bitmap 1540 * are on the same folio e4b->bd_buddy_folio is NULL and return value is 0. 1541 */ 1542static int ext4_mb_get_buddy_folio_lock(struct super_block *sb, 1543 ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp) 1544{ 1545 struct inode *inode = EXT4_SB(sb)->s_buddy_cache; 1546 int block, pnum; 1547 struct folio *folio; 1548 1549 e4b->bd_buddy_folio = NULL; 1550 e4b->bd_bitmap_folio = NULL; 1551 1552 /* 1553 * the buddy cache inode stores the block bitmap 1554 * and buddy information in consecutive blocks. 1555 * So for each group we need two blocks. 1556 */ 1557 block = group * 2; 1558 pnum = EXT4_LBLK_TO_PG(inode, block); 1559 folio = __filemap_get_folio(inode->i_mapping, pnum, 1560 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); 1561 if (IS_ERR(folio)) 1562 return PTR_ERR(folio); 1563 BUG_ON(folio->mapping != inode->i_mapping); 1564 WARN_ON_ONCE(folio_size(folio) < sb->s_blocksize); 1565 e4b->bd_bitmap_folio = folio; 1566 e4b->bd_bitmap = folio_address(folio) + 1567 offset_in_folio(folio, EXT4_LBLK_TO_B(inode, block)); 1568 1569 block++; 1570 pnum = EXT4_LBLK_TO_PG(inode, block); 1571 if (folio_contains(folio, pnum)) { 1572 /* buddy and bitmap are on the same folio */ 1573 return 0; 1574 } 1575 1576 /* we need another folio for the buddy */ 1577 folio = __filemap_get_folio(inode->i_mapping, pnum, 1578 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); 1579 if (IS_ERR(folio)) 1580 return PTR_ERR(folio); 1581 BUG_ON(folio->mapping != inode->i_mapping); 1582 WARN_ON_ONCE(folio_size(folio) < sb->s_blocksize); 1583 e4b->bd_buddy_folio = folio; 1584 return 0; 1585} 1586 1587static void ext4_mb_put_buddy_folio_lock(struct ext4_buddy *e4b) 1588{ 1589 if (e4b->bd_bitmap_folio) { 1590 folio_unlock(e4b->bd_bitmap_folio); 1591 folio_put(e4b->bd_bitmap_folio); 1592 } 1593 if (e4b->bd_buddy_folio) { 1594 folio_unlock(e4b->bd_buddy_folio); 1595 folio_put(e4b->bd_buddy_folio); 1596 } 1597} 1598 1599/* 1600 * Locking note: This routine calls ext4_mb_init_cache(), which takes the 1601 * block group lock of all groups for this folio; do not hold the BG lock when 1602 * calling this routine! 1603 */ 1604static noinline_for_stack 1605int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp) 1606{ 1607 1608 struct ext4_group_info *this_grp; 1609 struct ext4_buddy e4b; 1610 struct folio *folio; 1611 int ret = 0; 1612 1613 might_sleep(); 1614 mb_debug(sb, "init group %u\n", group); 1615 this_grp = ext4_get_group_info(sb, group); 1616 if (!this_grp) 1617 return -EFSCORRUPTED; 1618 1619 /* 1620 * This ensures that we don't reinit the buddy cache 1621 * folio which map to the group from which we are already 1622 * allocating. If we are looking at the buddy cache we would 1623 * have taken a reference using ext4_mb_load_buddy and that 1624 * would have pinned buddy folio to page cache. 1625 * The call to ext4_mb_get_buddy_folio_lock will mark the 1626 * folio accessed. 1627 */ 1628 ret = ext4_mb_get_buddy_folio_lock(sb, group, &e4b, gfp); 1629 if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) { 1630 /* 1631 * somebody initialized the group 1632 * return without doing anything 1633 */ 1634 goto err; 1635 } 1636 1637 folio = e4b.bd_bitmap_folio; 1638 ret = ext4_mb_init_cache(folio, NULL, gfp); 1639 if (ret) 1640 goto err; 1641 if (!folio_test_uptodate(folio)) { 1642 ret = -EIO; 1643 goto err; 1644 } 1645 1646 if (e4b.bd_buddy_folio == NULL) { 1647 /* 1648 * If both the bitmap and buddy are in 1649 * the same folio we don't need to force 1650 * init the buddy 1651 */ 1652 ret = 0; 1653 goto err; 1654 } 1655 /* init buddy cache */ 1656 folio = e4b.bd_buddy_folio; 1657 ret = ext4_mb_init_cache(folio, e4b.bd_bitmap, gfp); 1658 if (ret) 1659 goto err; 1660 if (!folio_test_uptodate(folio)) { 1661 ret = -EIO; 1662 goto err; 1663 } 1664err: 1665 ext4_mb_put_buddy_folio_lock(&e4b); 1666 return ret; 1667} 1668 1669/* 1670 * Locking note: This routine calls ext4_mb_init_cache(), which takes the 1671 * block group lock of all groups for this folio; do not hold the BG lock when 1672 * calling this routine! 1673 */ 1674static noinline_for_stack int 1675ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group, 1676 struct ext4_buddy *e4b, gfp_t gfp) 1677{ 1678 int block; 1679 int pnum; 1680 struct folio *folio; 1681 int ret; 1682 struct ext4_group_info *grp; 1683 struct ext4_sb_info *sbi = EXT4_SB(sb); 1684 struct inode *inode = sbi->s_buddy_cache; 1685 1686 might_sleep(); 1687 mb_debug(sb, "load group %u\n", group); 1688 1689 grp = ext4_get_group_info(sb, group); 1690 if (!grp) 1691 return -EFSCORRUPTED; 1692 1693 e4b->bd_blkbits = sb->s_blocksize_bits; 1694 e4b->bd_info = grp; 1695 e4b->bd_sb = sb; 1696 e4b->bd_group = group; 1697 e4b->bd_buddy_folio = NULL; 1698 e4b->bd_bitmap_folio = NULL; 1699 1700 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { 1701 /* 1702 * we need full data about the group 1703 * to make a good selection 1704 */ 1705 ret = ext4_mb_init_group(sb, group, gfp); 1706 if (ret) 1707 return ret; 1708 } 1709 1710 /* 1711 * the buddy cache inode stores the block bitmap 1712 * and buddy information in consecutive blocks. 1713 * So for each group we need two blocks. 1714 */ 1715 block = group * 2; 1716 pnum = EXT4_LBLK_TO_PG(inode, block); 1717 1718 /* Avoid locking the folio in the fast path ... */ 1719 folio = __filemap_get_folio(inode->i_mapping, pnum, FGP_ACCESSED, 0); 1720 if (IS_ERR(folio) || !folio_test_uptodate(folio) || folio_test_locked(folio)) { 1721 /* 1722 * folio_test_locked is employed to detect ongoing folio 1723 * migrations, since concurrent migrations can lead to 1724 * bitmap inconsistency. And if we are not uptodate that 1725 * implies somebody just created the folio but is yet to 1726 * initialize it. We can drop the folio reference and 1727 * try to get the folio with lock in both cases to avoid 1728 * concurrency. 1729 */ 1730 if (!IS_ERR(folio)) 1731 folio_put(folio); 1732 folio = __filemap_get_folio(inode->i_mapping, pnum, 1733 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); 1734 if (!IS_ERR(folio)) { 1735 if (WARN_RATELIMIT(folio->mapping != inode->i_mapping, 1736 "ext4: bitmap's mapping != inode->i_mapping\n")) { 1737 /* should never happen */ 1738 folio_unlock(folio); 1739 ret = -EINVAL; 1740 goto err; 1741 } 1742 if (!folio_test_uptodate(folio)) { 1743 ret = ext4_mb_init_cache(folio, NULL, gfp); 1744 if (ret) { 1745 folio_unlock(folio); 1746 goto err; 1747 } 1748 mb_cmp_bitmaps(e4b, folio_address(folio) + 1749 offset_in_folio(folio, 1750 EXT4_LBLK_TO_B(inode, block))); 1751 } 1752 folio_unlock(folio); 1753 } 1754 } 1755 if (IS_ERR(folio)) { 1756 ret = PTR_ERR(folio); 1757 goto err; 1758 } 1759 if (!folio_test_uptodate(folio)) { 1760 ret = -EIO; 1761 goto err; 1762 } 1763 1764 /* Folios marked accessed already */ 1765 e4b->bd_bitmap_folio = folio; 1766 e4b->bd_bitmap = folio_address(folio) + 1767 offset_in_folio(folio, EXT4_LBLK_TO_B(inode, block)); 1768 1769 block++; 1770 pnum = EXT4_LBLK_TO_PG(inode, block); 1771 /* buddy and bitmap are on the same folio? */ 1772 if (folio_contains(folio, pnum)) { 1773 folio_get(folio); 1774 goto update_buddy; 1775 } 1776 1777 /* we need another folio for the buddy */ 1778 folio = __filemap_get_folio(inode->i_mapping, pnum, FGP_ACCESSED, 0); 1779 if (IS_ERR(folio) || !folio_test_uptodate(folio) || folio_test_locked(folio)) { 1780 if (!IS_ERR(folio)) 1781 folio_put(folio); 1782 folio = __filemap_get_folio(inode->i_mapping, pnum, 1783 FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); 1784 if (!IS_ERR(folio)) { 1785 if (WARN_RATELIMIT(folio->mapping != inode->i_mapping, 1786 "ext4: buddy bitmap's mapping != inode->i_mapping\n")) { 1787 /* should never happen */ 1788 folio_unlock(folio); 1789 ret = -EINVAL; 1790 goto err; 1791 } 1792 if (!folio_test_uptodate(folio)) { 1793 ret = ext4_mb_init_cache(folio, e4b->bd_bitmap, 1794 gfp); 1795 if (ret) { 1796 folio_unlock(folio); 1797 goto err; 1798 } 1799 } 1800 folio_unlock(folio); 1801 } 1802 } 1803 if (IS_ERR(folio)) { 1804 ret = PTR_ERR(folio); 1805 goto err; 1806 } 1807 if (!folio_test_uptodate(folio)) { 1808 ret = -EIO; 1809 goto err; 1810 } 1811 1812update_buddy: 1813 /* Folios marked accessed already */ 1814 e4b->bd_buddy_folio = folio; 1815 e4b->bd_buddy = folio_address(folio) + 1816 offset_in_folio(folio, EXT4_LBLK_TO_B(inode, block)); 1817 1818 return 0; 1819 1820err: 1821 if (!IS_ERR_OR_NULL(folio)) 1822 folio_put(folio); 1823 if (e4b->bd_bitmap_folio) 1824 folio_put(e4b->bd_bitmap_folio); 1825 1826 e4b->bd_buddy = NULL; 1827 e4b->bd_bitmap = NULL; 1828 return ret; 1829} 1830 1831static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, 1832 struct ext4_buddy *e4b) 1833{ 1834 return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS); 1835} 1836 1837static void ext4_mb_unload_buddy(struct ext4_buddy *e4b) 1838{ 1839 if (e4b->bd_bitmap_folio) 1840 folio_put(e4b->bd_bitmap_folio); 1841 if (e4b->bd_buddy_folio) 1842 folio_put(e4b->bd_buddy_folio); 1843} 1844 1845 1846static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) 1847{ 1848 int order = 1, max; 1849 void *bb; 1850 1851 BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); 1852 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); 1853 1854 while (order <= e4b->bd_blkbits + 1) { 1855 bb = mb_find_buddy(e4b, order, &max); 1856 if (!mb_test_bit(block >> order, bb)) { 1857 /* this block is part of buddy of order 'order' */ 1858 return order; 1859 } 1860 order++; 1861 } 1862 return 0; 1863} 1864 1865static void mb_clear_bits(void *bm, int cur, int len) 1866{ 1867 __u32 *addr; 1868 1869 len = cur + len; 1870 while (cur < len) { 1871 if ((cur & 31) == 0 && (len - cur) >= 32) { 1872 /* fast path: clear whole word at once */ 1873 addr = bm + (cur >> 3); 1874 *addr = 0; 1875 cur += 32; 1876 continue; 1877 } 1878 mb_clear_bit(cur, bm); 1879 cur++; 1880 } 1881} 1882 1883/* clear bits in given range 1884 * will return first found zero bit if any, -1 otherwise 1885 */ 1886static int mb_test_and_clear_bits(void *bm, int cur, int len) 1887{ 1888 __u32 *addr; 1889 int zero_bit = -1; 1890 1891 len = cur + len; 1892 while (cur < len) { 1893 if ((cur & 31) == 0 && (len - cur) >= 32) { 1894 /* fast path: clear whole word at once */ 1895 addr = bm + (cur >> 3); 1896 if (*addr != (__u32)(-1) && zero_bit == -1) 1897 zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0); 1898 *addr = 0; 1899 cur += 32; 1900 continue; 1901 } 1902 if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1) 1903 zero_bit = cur; 1904 cur++; 1905 } 1906 1907 return zero_bit; 1908} 1909 1910void mb_set_bits(void *bm, int cur, int len) 1911{ 1912 __u32 *addr; 1913 1914 len = cur + len; 1915 while (cur < len) { 1916 if ((cur & 31) == 0 && (len - cur) >= 32) { 1917 /* fast path: set whole word at once */ 1918 addr = bm + (cur >> 3); 1919 *addr = 0xffffffff; 1920 cur += 32; 1921 continue; 1922 } 1923 mb_set_bit(cur, bm); 1924 cur++; 1925 } 1926} 1927 1928static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side) 1929{ 1930 if (mb_test_bit(*bit + side, bitmap)) { 1931 mb_clear_bit(*bit, bitmap); 1932 (*bit) -= side; 1933 return 1; 1934 } 1935 else { 1936 (*bit) += side; 1937 mb_set_bit(*bit, bitmap); 1938 return -1; 1939 } 1940} 1941 1942static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last) 1943{ 1944 int max; 1945 int order = 1; 1946 void *buddy = mb_find_buddy(e4b, order, &max); 1947 1948 while (buddy) { 1949 void *buddy2; 1950 1951 /* Bits in range [first; last] are known to be set since 1952 * corresponding blocks were allocated. Bits in range 1953 * (first; last) will stay set because they form buddies on 1954 * upper layer. We just deal with borders if they don't 1955 * align with upper layer and then go up. 1956 * Releasing entire group is all about clearing 1957 * single bit of highest order buddy. 1958 */ 1959 1960 /* Example: 1961 * --------------------------------- 1962 * | 1 | 1 | 1 | 1 | 1963 * --------------------------------- 1964 * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1965 * --------------------------------- 1966 * 0 1 2 3 4 5 6 7 1967 * \_____________________/ 1968 * 1969 * Neither [1] nor [6] is aligned to above layer. 1970 * Left neighbour [0] is free, so mark it busy, 1971 * decrease bb_counters and extend range to 1972 * [0; 6] 1973 * Right neighbour [7] is busy. It can't be coaleasced with [6], so 1974 * mark [6] free, increase bb_counters and shrink range to 1975 * [0; 5]. 1976 * Then shift range to [0; 2], go up and do the same. 1977 */ 1978 1979 1980 if (first & 1) 1981 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1); 1982 if (!(last & 1)) 1983 e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1); 1984 if (first > last) 1985 break; 1986 order++; 1987 1988 buddy2 = mb_find_buddy(e4b, order, &max); 1989 if (!buddy2) { 1990 mb_clear_bits(buddy, first, last - first + 1); 1991 e4b->bd_info->bb_counters[order - 1] += last - first + 1; 1992 break; 1993 } 1994 first >>= 1; 1995 last >>= 1; 1996 buddy = buddy2; 1997 } 1998} 1999 2000static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, 2001 int first, int count) 2002{ 2003 int left_is_free = 0; 2004 int right_is_free = 0; 2005 int block; 2006 int last = first + count - 1; 2007 struct super_block *sb = e4b->bd_sb; 2008 2009 if (WARN_ON(count == 0)) 2010 return; 2011 BUG_ON(last >= (sb->s_blocksize << 3)); 2012 assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); 2013 /* Don't bother if the block group is corrupt. */ 2014 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) 2015 return; 2016 2017 mb_check_buddy(e4b); 2018 mb_free_blocks_double(inode, e4b, first, count); 2019 2020 /* access memory sequentially: check left neighbour, 2021 * clear range and then check right neighbour 2022 */ 2023 if (first != 0) 2024 left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap); 2025 block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count); 2026 if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0]) 2027 right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap); 2028 2029 if (unlikely(block != -1)) { 2030 struct ext4_sb_info *sbi = EXT4_SB(sb); 2031 ext4_fsblk_t blocknr; 2032 2033 /* 2034 * Fastcommit replay can free already freed blocks which 2035 * corrupts allocation info. Regenerate it. 2036 */ 2037 if (sbi->s_mount_state & EXT4_FC_REPLAY) { 2038 mb_regenerate_buddy(e4b); 2039 goto check; 2040 } 2041 2042 blocknr = ext4_group_first_block_no(sb, e4b->bd_group); 2043 blocknr += EXT4_C2B(sbi, block); 2044 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, 2045 EXT4_GROUP_INFO_BBITMAP_CORRUPT); 2046 ext4_grp_locked_error(sb, e4b->bd_group, 2047 inode ? inode->i_ino : 0, blocknr, 2048 "freeing already freed block (bit %u); block bitmap corrupt.", 2049 block); 2050 return; 2051 } 2052 2053 this_cpu_inc(discard_pa_seq); 2054 e4b->bd_info->bb_free += count; 2055 if (first < e4b->bd_info->bb_first_free) 2056 e4b->bd_info->bb_first_free = first; 2057 2058 /* let's maintain fragments counter */ 2059 if (left_is_free && right_is_free) 2060 e4b->bd_info->bb_fragments--; 2061 else if (!left_is_free && !right_is_free) 2062 e4b->bd_info->bb_fragments++; 2063 2064 /* buddy[0] == bd_bitmap is a special case, so handle 2065 * it right away and let mb_buddy_mark_free stay free of 2066 * zero order checks. 2067 * Check if neighbours are to be coaleasced, 2068 * adjust bitmap bb_counters and borders appropriately. 2069 */ 2070 if (first & 1) { 2071 first += !left_is_free; 2072 e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1; 2073 } 2074 if (!(last & 1)) { 2075 last -= !right_is_free; 2076 e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1; 2077 } 2078 2079 if (first <= last) 2080 mb_buddy_mark_free(e4b, first >> 1, last >> 1); 2081 2082 mb_set_largest_free_order(sb, e4b->bd_info); 2083 mb_update_avg_fragment_size(sb, e4b->bd_info); 2084check: 2085 mb_check_buddy(e4b); 2086} 2087 2088static int mb_find_extent(struct ext4_buddy *e4b, int block, 2089 int needed, struct ext4_free_extent *ex) 2090{ 2091 int max, order, next; 2092 void *buddy; 2093 2094 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); 2095 BUG_ON(ex == NULL); 2096 2097 buddy = mb_find_buddy(e4b, 0, &max); 2098 BUG_ON(buddy == NULL); 2099 BUG_ON(block >= max); 2100 if (mb_test_bit(block, buddy)) { 2101 ex->fe_len = 0; 2102 ex->fe_start = 0; 2103 ex->fe_group = 0; 2104 return 0; 2105 } 2106 2107 /* find actual order */ 2108 order = mb_find_order_for_block(e4b, block); 2109 2110 ex->fe_len = (1 << order) - (block & ((1 << order) - 1)); 2111 ex->fe_start = block; 2112 ex->fe_group = e4b->bd_group; 2113 2114 block = block >> order; 2115 2116 while (needed > ex->fe_len && 2117 mb_find_buddy(e4b, order, &max)) { 2118 2119 if (block + 1 >= max) 2120 break; 2121 2122 next = (block + 1) * (1 << order); 2123 if (mb_test_bit(next, e4b->bd_bitmap)) 2124 break; 2125 2126 order = mb_find_order_for_block(e4b, next); 2127 2128 block = next >> order; 2129 ex->fe_len += 1 << order; 2130 } 2131 2132 if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) { 2133 /* Should never happen! (but apparently sometimes does?!?) */ 2134 WARN_ON(1); 2135 ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0, 2136 "corruption or bug in mb_find_extent " 2137 "block=%d, order=%d needed=%d ex=%u/%d/%d@%u", 2138 block, order, needed, ex->fe_group, ex->fe_start, 2139 ex->fe_len, ex->fe_logical); 2140 ex->fe_len = 0; 2141 ex->fe_start = 0; 2142 ex->fe_group = 0; 2143 } 2144 return ex->fe_len; 2145} 2146 2147static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) 2148{ 2149 int ord; 2150 int mlen = 0; 2151 int max = 0; 2152 int start = ex->fe_start; 2153 int len = ex->fe_len; 2154 unsigned ret = 0; 2155 int len0 = len; 2156 void *buddy; 2157 int ord_start, ord_end; 2158 2159 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); 2160 BUG_ON(e4b->bd_group != ex->fe_group); 2161 assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); 2162 mb_check_buddy(e4b); 2163 mb_mark_used_double(e4b, start, len); 2164 2165 this_cpu_inc(discard_pa_seq); 2166 e4b->bd_info->bb_free -= len; 2167 if (e4b->bd_info->bb_first_free == start) 2168 e4b->bd_info->bb_first_free += len; 2169 2170 /* let's maintain fragments counter */ 2171 if (start != 0) 2172 mlen = !mb_test_bit(start - 1, e4b->bd_bitmap); 2173 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0]) 2174 max = !mb_test_bit(start + len, e4b->bd_bitmap); 2175 if (mlen && max) 2176 e4b->bd_info->bb_fragments++; 2177 else if (!mlen && !max) 2178 e4b->bd_info->bb_fragments--; 2179 2180 /* let's maintain buddy itself */ 2181 while (len) { 2182 ord = mb_find_order_for_block(e4b, start); 2183 2184 if (((start >> ord) << ord) == start && len >= (1 << ord)) { 2185 /* the whole chunk may be allocated at once! */ 2186 mlen = 1 << ord; 2187 buddy = mb_find_buddy(e4b, ord, &max); 2188 BUG_ON((start >> ord) >= max); 2189 mb_set_bit(start >> ord, buddy); 2190 e4b->bd_info->bb_counters[ord]--; 2191 start += mlen; 2192 len -= mlen; 2193 BUG_ON(len < 0); 2194 continue; 2195 } 2196 2197 /* store for history */ 2198 if (ret == 0) 2199 ret = len | (ord << 16); 2200 2201 BUG_ON(ord <= 0); 2202 buddy = mb_find_buddy(e4b, ord, &max); 2203 mb_set_bit(start >> ord, buddy); 2204 e4b->bd_info->bb_counters[ord]--; 2205 2206 ord_start = (start >> ord) << ord; 2207 ord_end = ord_start + (1 << ord); 2208 /* first chunk */ 2209 if (start > ord_start) 2210 ext4_mb_mark_free_simple(e4b->bd_sb, e4b->bd_buddy, 2211 ord_start, start - ord_start, 2212 e4b->bd_info); 2213 2214 /* last chunk */ 2215 if (start + len < ord_end) { 2216 ext4_mb_mark_free_simple(e4b->bd_sb, e4b->bd_buddy, 2217 start + len, 2218 ord_end - (start + len), 2219 e4b->bd_info); 2220 break; 2221 } 2222 len = start + len - ord_end; 2223 start = ord_end; 2224 } 2225 mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info); 2226 2227 mb_update_avg_fragment_size(e4b->bd_sb, e4b->bd_info); 2228 mb_set_bits(e4b->bd_bitmap, ex->fe_start, len0); 2229 mb_check_buddy(e4b); 2230 2231 return ret; 2232} 2233 2234/* 2235 * Must be called under group lock! 2236 */ 2237static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, 2238 struct ext4_buddy *e4b) 2239{ 2240 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 2241 int ret; 2242 2243 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group); 2244 BUG_ON(ac->ac_status == AC_STATUS_FOUND); 2245 2246 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len); 2247 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical; 2248 ret = mb_mark_used(e4b, &ac->ac_b_ex); 2249 2250 /* preallocation can change ac_b_ex, thus we store actually 2251 * allocated blocks for history */ 2252 ac->ac_f_ex = ac->ac_b_ex; 2253 2254 ac->ac_status = AC_STATUS_FOUND; 2255 ac->ac_tail = ret & 0xffff; 2256 ac->ac_buddy = ret >> 16; 2257 2258 /* 2259 * take the folio reference. We want the folio to be pinned 2260 * so that we don't get a ext4_mb_init_cache_call for this 2261 * group until we update the bitmap. That would mean we 2262 * double allocate blocks. The reference is dropped 2263 * in ext4_mb_release_context 2264 */ 2265 ac->ac_bitmap_folio = e4b->bd_bitmap_folio; 2266 folio_get(ac->ac_bitmap_folio); 2267 ac->ac_buddy_folio = e4b->bd_buddy_folio; 2268 folio_get(ac->ac_buddy_folio); 2269 /* store last allocated for subsequent stream allocation */ 2270 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { 2271 int hash = ac->ac_inode->i_ino % sbi->s_mb_nr_global_goals; 2272 2273 WRITE_ONCE(sbi->s_mb_last_groups[hash], ac->ac_f_ex.fe_group); 2274 } 2275 2276 /* 2277 * As we've just preallocated more space than 2278 * user requested originally, we store allocated 2279 * space in a special descriptor. 2280 */ 2281 if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len) 2282 ext4_mb_new_preallocation(ac); 2283 2284} 2285 2286static void ext4_mb_check_limits(struct ext4_allocation_context *ac, 2287 struct ext4_buddy *e4b, 2288 int finish_group) 2289{ 2290 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 2291 struct ext4_free_extent *bex = &ac->ac_b_ex; 2292 struct ext4_free_extent *gex = &ac->ac_g_ex; 2293 2294 if (ac->ac_status == AC_STATUS_FOUND) 2295 return; 2296 /* 2297 * We don't want to scan for a whole year 2298 */ 2299 if (ac->ac_found > sbi->s_mb_max_to_scan && 2300 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { 2301 ac->ac_status = AC_STATUS_BREAK; 2302 return; 2303 } 2304 2305 /* 2306 * Haven't found good chunk so far, let's continue 2307 */ 2308 if (bex->fe_len < gex->fe_len) 2309 return; 2310 2311 if (finish_group || ac->ac_found > sbi->s_mb_min_to_scan) 2312 ext4_mb_use_best_found(ac, e4b); 2313} 2314 2315/* 2316 * The routine checks whether found extent is good enough. If it is, 2317 * then the extent gets marked used and flag is set to the context 2318 * to stop scanning. Otherwise, the extent is compared with the 2319 * previous found extent and if new one is better, then it's stored 2320 * in the context. Later, the best found extent will be used, if 2321 * mballoc can't find good enough extent. 2322 * 2323 * The algorithm used is roughly as follows: 2324 * 2325 * * If free extent found is exactly as big as goal, then 2326 * stop the scan and use it immediately 2327 * 2328 * * If free extent found is smaller than goal, then keep retrying 2329 * upto a max of sbi->s_mb_max_to_scan times (default 200). After 2330 * that stop scanning and use whatever we have. 2331 * 2332 * * If free extent found is bigger than goal, then keep retrying 2333 * upto a max of sbi->s_mb_min_to_scan times (default 10) before 2334 * stopping the scan and using the extent. 2335 * 2336 * 2337 * FIXME: real allocation policy is to be designed yet! 2338 */ 2339static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, 2340 struct ext4_free_extent *ex, 2341 struct ext4_buddy *e4b) 2342{ 2343 struct ext4_free_extent *bex = &ac->ac_b_ex; 2344 struct ext4_free_extent *gex = &ac->ac_g_ex; 2345 2346 BUG_ON(ex->fe_len <= 0); 2347 BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); 2348 BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); 2349 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); 2350 2351 ac->ac_found++; 2352 ac->ac_cX_found[ac->ac_criteria]++; 2353 2354 /* 2355 * The special case - take what you catch first 2356 */ 2357 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) { 2358 *bex = *ex; 2359 ext4_mb_use_best_found(ac, e4b); 2360 return; 2361 } 2362 2363 /* 2364 * Let's check whether the chuck is good enough 2365 */ 2366 if (ex->fe_len == gex->fe_len) { 2367 *bex = *ex; 2368 ext4_mb_use_best_found(ac, e4b); 2369 return; 2370 } 2371 2372 /* 2373 * If this is first found extent, just store it in the context 2374 */ 2375 if (bex->fe_len == 0) { 2376 *bex = *ex; 2377 return; 2378 } 2379 2380 /* 2381 * If new found extent is better, store it in the context 2382 */ 2383 if (bex->fe_len < gex->fe_len) { 2384 /* if the request isn't satisfied, any found extent 2385 * larger than previous best one is better */ 2386 if (ex->fe_len > bex->fe_len) 2387 *bex = *ex; 2388 } else if (ex->fe_len > gex->fe_len) { 2389 /* if the request is satisfied, then we try to find 2390 * an extent that still satisfy the request, but is 2391 * smaller than previous one */ 2392 if (ex->fe_len < bex->fe_len) 2393 *bex = *ex; 2394 } 2395 2396 ext4_mb_check_limits(ac, e4b, 0); 2397} 2398 2399static noinline_for_stack 2400void ext4_mb_try_best_found(struct ext4_allocation_context *ac, 2401 struct ext4_buddy *e4b) 2402{ 2403 struct ext4_free_extent ex = ac->ac_b_ex; 2404 ext4_group_t group = ex.fe_group; 2405 int max; 2406 int err; 2407 2408 BUG_ON(ex.fe_len <= 0); 2409 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); 2410 if (err) 2411 return; 2412 2413 ext4_lock_group(ac->ac_sb, group); 2414 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) 2415 goto out; 2416 2417 max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex); 2418 2419 if (max > 0) { 2420 ac->ac_b_ex = ex; 2421 ext4_mb_use_best_found(ac, e4b); 2422 } 2423 2424out: 2425 ext4_unlock_group(ac->ac_sb, group); 2426 ext4_mb_unload_buddy(e4b); 2427} 2428 2429static noinline_for_stack 2430int ext4_mb_find_by_goal(struct ext4_allocation_context *ac, 2431 struct ext4_buddy *e4b) 2432{ 2433 ext4_group_t group = ac->ac_g_ex.fe_group; 2434 int max; 2435 int err; 2436 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 2437 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); 2438 struct ext4_free_extent ex; 2439 2440 if (!grp) 2441 return -EFSCORRUPTED; 2442 if (!(ac->ac_flags & (EXT4_MB_HINT_TRY_GOAL | EXT4_MB_HINT_GOAL_ONLY))) 2443 return 0; 2444 if (grp->bb_free == 0) 2445 return 0; 2446 2447 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); 2448 if (err) { 2449 if (EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info) && 2450 !(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) 2451 return 0; 2452 return err; 2453 } 2454 2455 ext4_lock_group(ac->ac_sb, group); 2456 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) 2457 goto out; 2458 2459 max = mb_find_extent(e4b, ac->ac_g_ex.fe_start, 2460 ac->ac_g_ex.fe_len, &ex); 2461 ex.fe_logical = 0xDEADFA11; /* debug value */ 2462 2463 if (max >= ac->ac_g_ex.fe_len && 2464 ac->ac_g_ex.fe_len == EXT4_NUM_B2C(sbi, sbi->s_stripe)) { 2465 ext4_fsblk_t start; 2466 2467 start = ext4_grp_offs_to_block(ac->ac_sb, &ex); 2468 /* use do_div to get remainder (would be 64-bit modulo) */ 2469 if (do_div(start, sbi->s_stripe) == 0) { 2470 ac->ac_found++; 2471 ac->ac_b_ex = ex; 2472 ext4_mb_use_best_found(ac, e4b); 2473 } 2474 } else if (max >= ac->ac_g_ex.fe_len) { 2475 BUG_ON(ex.fe_len <= 0); 2476 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); 2477 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); 2478 ac->ac_found++; 2479 ac->ac_b_ex = ex; 2480 ext4_mb_use_best_found(ac, e4b); 2481 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) { 2482 /* Sometimes, caller may want to merge even small 2483 * number of blocks to an existing extent */ 2484 BUG_ON(ex.fe_len <= 0); 2485 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); 2486 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); 2487 ac->ac_found++; 2488 ac->ac_b_ex = ex; 2489 ext4_mb_use_best_found(ac, e4b); 2490 } 2491out: 2492 ext4_unlock_group(ac->ac_sb, group); 2493 ext4_mb_unload_buddy(e4b); 2494 2495 return 0; 2496} 2497 2498/* 2499 * The routine scans buddy structures (not bitmap!) from given order 2500 * to max order and tries to find big enough chunk to satisfy the req 2501 */ 2502static noinline_for_stack 2503void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, 2504 struct ext4_buddy *e4b) 2505{ 2506 struct super_block *sb = ac->ac_sb; 2507 struct ext4_group_info *grp = e4b->bd_info; 2508 void *buddy; 2509 int i; 2510 int k; 2511 int max; 2512 2513 BUG_ON(ac->ac_2order <= 0); 2514 for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) { 2515 if (grp->bb_counters[i] == 0) 2516 continue; 2517 2518 buddy = mb_find_buddy(e4b, i, &max); 2519 if (WARN_RATELIMIT(buddy == NULL, 2520 "ext4: mb_simple_scan_group: mb_find_buddy failed, (%d)\n", i)) 2521 continue; 2522 2523 k = mb_find_next_zero_bit(buddy, max, 0); 2524 if (k >= max) { 2525 ext4_mark_group_bitmap_corrupted(ac->ac_sb, 2526 e4b->bd_group, 2527 EXT4_GROUP_INFO_BBITMAP_CORRUPT); 2528 ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0, 2529 "%d free clusters of order %d. But found 0", 2530 grp->bb_counters[i], i); 2531 break; 2532 } 2533 ac->ac_found++; 2534 ac->ac_cX_found[ac->ac_criteria]++; 2535 2536 ac->ac_b_ex.fe_len = 1 << i; 2537 ac->ac_b_ex.fe_start = k << i; 2538 ac->ac_b_ex.fe_group = e4b->bd_group; 2539 2540 ext4_mb_use_best_found(ac, e4b); 2541 2542 BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len); 2543 2544 if (EXT4_SB(sb)->s_mb_stats) 2545 atomic_inc(&EXT4_SB(sb)->s_bal_2orders); 2546 2547 break; 2548 } 2549} 2550 2551/* 2552 * The routine scans the group and measures all found extents. 2553 * In order to optimize scanning, caller must pass number of 2554 * free blocks in the group, so the routine can know upper limit. 2555 */ 2556static noinline_for_stack 2557void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, 2558 struct ext4_buddy *e4b) 2559{ 2560 struct super_block *sb = ac->ac_sb; 2561 void *bitmap = e4b->bd_bitmap; 2562 struct ext4_free_extent ex; 2563 int i, j, freelen; 2564 int free; 2565 2566 free = e4b->bd_info->bb_free; 2567 if (WARN_ON(free <= 0)) 2568 return; 2569 2570 i = e4b->bd_info->bb_first_free; 2571 2572 while (free && ac->ac_status == AC_STATUS_CONTINUE) { 2573 i = mb_find_next_zero_bit(bitmap, 2574 EXT4_CLUSTERS_PER_GROUP(sb), i); 2575 if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) { 2576 /* 2577 * IF we have corrupt bitmap, we won't find any 2578 * free blocks even though group info says we 2579 * have free blocks 2580 */ 2581 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, 2582 EXT4_GROUP_INFO_BBITMAP_CORRUPT); 2583 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, 2584 "%d free clusters as per " 2585 "group info. But bitmap says 0", 2586 free); 2587 break; 2588 } 2589 2590 if (!ext4_mb_cr_expensive(ac->ac_criteria)) { 2591 /* 2592 * In CR_GOAL_LEN_FAST and CR_BEST_AVAIL_LEN, we are 2593 * sure that this group will have a large enough 2594 * continuous free extent, so skip over the smaller free 2595 * extents 2596 */ 2597 j = mb_find_next_bit(bitmap, 2598 EXT4_CLUSTERS_PER_GROUP(sb), i); 2599 freelen = j - i; 2600 2601 if (freelen < ac->ac_g_ex.fe_len) { 2602 i = j; 2603 free -= freelen; 2604 continue; 2605 } 2606 } 2607 2608 mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex); 2609 if (WARN_ON(ex.fe_len <= 0)) 2610 break; 2611 if (free < ex.fe_len) { 2612 ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, 2613 EXT4_GROUP_INFO_BBITMAP_CORRUPT); 2614 ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, 2615 "%d free clusters as per " 2616 "group info. But got %d blocks", 2617 free, ex.fe_len); 2618 /* 2619 * The number of free blocks differs. This mostly 2620 * indicate that the bitmap is corrupt. So exit 2621 * without claiming the space. 2622 */ 2623 break; 2624 } 2625 ex.fe_logical = 0xDEADC0DE; /* debug value */ 2626 ext4_mb_measure_extent(ac, &ex, e4b); 2627 2628 i += ex.fe_len; 2629 free -= ex.fe_len; 2630 } 2631 2632 ext4_mb_check_limits(ac, e4b, 1); 2633} 2634 2635/* 2636 * This is a special case for storages like raid5 2637 * we try to find stripe-aligned chunks for stripe-size-multiple requests 2638 */ 2639static noinline_for_stack 2640void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, 2641 struct ext4_buddy *e4b) 2642{ 2643 struct super_block *sb = ac->ac_sb; 2644 struct ext4_sb_info *sbi = EXT4_SB(sb); 2645 void *bitmap = e4b->bd_bitmap; 2646 struct ext4_free_extent ex; 2647 ext4_fsblk_t first_group_block; 2648 ext4_fsblk_t a; 2649 ext4_grpblk_t i, stripe; 2650 int max; 2651 2652 BUG_ON(sbi->s_stripe == 0); 2653 2654 /* find first stripe-aligned block in group */ 2655 first_group_block = ext4_group_first_block_no(sb, e4b->bd_group); 2656 2657 a = first_group_block + sbi->s_stripe - 1; 2658 do_div(a, sbi->s_stripe); 2659 i = (a * sbi->s_stripe) - first_group_block; 2660 2661 stripe = EXT4_NUM_B2C(sbi, sbi->s_stripe); 2662 i = EXT4_B2C(sbi, i); 2663 while (i < EXT4_CLUSTERS_PER_GROUP(sb)) { 2664 if (!mb_test_bit(i, bitmap)) { 2665 max = mb_find_extent(e4b, i, stripe, &ex); 2666 if (max >= stripe) { 2667 ac->ac_found++; 2668 ac->ac_cX_found[ac->ac_criteria]++; 2669 ex.fe_logical = 0xDEADF00D; /* debug value */ 2670 ac->ac_b_ex = ex; 2671 ext4_mb_use_best_found(ac, e4b); 2672 break; 2673 } 2674 } 2675 i += stripe; 2676 } 2677} 2678 2679static void __ext4_mb_scan_group(struct ext4_allocation_context *ac) 2680{ 2681 bool is_stripe_aligned; 2682 struct ext4_sb_info *sbi; 2683 enum criteria cr = ac->ac_criteria; 2684 2685 ac->ac_groups_scanned++; 2686 if (cr == CR_POWER2_ALIGNED) 2687 return ext4_mb_simple_scan_group(ac, ac->ac_e4b); 2688 2689 sbi = EXT4_SB(ac->ac_sb); 2690 is_stripe_aligned = false; 2691 if ((sbi->s_stripe >= sbi->s_cluster_ratio) && 2692 !(ac->ac_g_ex.fe_len % EXT4_NUM_B2C(sbi, sbi->s_stripe))) 2693 is_stripe_aligned = true; 2694 2695 if ((cr == CR_GOAL_LEN_FAST || cr == CR_BEST_AVAIL_LEN) && 2696 is_stripe_aligned) 2697 ext4_mb_scan_aligned(ac, ac->ac_e4b); 2698 2699 if (ac->ac_status == AC_STATUS_CONTINUE) 2700 ext4_mb_complex_scan_group(ac, ac->ac_e4b); 2701} 2702 2703/* 2704 * This is also called BEFORE we load the buddy bitmap. 2705 * Returns either 1 or 0 indicating that the group is either suitable 2706 * for the allocation or not. 2707 */ 2708static bool ext4_mb_good_group(struct ext4_allocation_context *ac, 2709 ext4_group_t group, enum criteria cr) 2710{ 2711 ext4_grpblk_t free, fragments; 2712 int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb)); 2713 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); 2714 2715 BUG_ON(cr < CR_POWER2_ALIGNED || cr >= EXT4_MB_NUM_CRS); 2716 2717 if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) 2718 return false; 2719 2720 free = grp->bb_free; 2721 if (free == 0) 2722 return false; 2723 2724 fragments = grp->bb_fragments; 2725 if (fragments == 0) 2726 return false; 2727 2728 switch (cr) { 2729 case CR_POWER2_ALIGNED: 2730 BUG_ON(ac->ac_2order == 0); 2731 2732 /* Avoid using the first bg of a flexgroup for data files */ 2733 if ((ac->ac_flags & EXT4_MB_HINT_DATA) && 2734 (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) && 2735 ((group % flex_size) == 0)) 2736 return false; 2737 2738 if (free < ac->ac_g_ex.fe_len) 2739 return false; 2740 2741 if (ac->ac_2order >= MB_NUM_ORDERS(ac->ac_sb)) 2742 return true; 2743 2744 if (grp->bb_largest_free_order < ac->ac_2order) 2745 return false; 2746 2747 return true; 2748 case CR_GOAL_LEN_FAST: 2749 case CR_BEST_AVAIL_LEN: 2750 if ((free / fragments) >= ac->ac_g_ex.fe_len) 2751 return true; 2752 break; 2753 case CR_GOAL_LEN_SLOW: 2754 if (free >= ac->ac_g_ex.fe_len) 2755 return true; 2756 break; 2757 case CR_ANY_FREE: 2758 return true; 2759 default: 2760 BUG(); 2761 } 2762 2763 return false; 2764} 2765 2766/* 2767 * This could return negative error code if something goes wrong 2768 * during ext4_mb_init_group(). This should not be called with 2769 * ext4_lock_group() held. 2770 * 2771 * Note: because we are conditionally operating with the group lock in 2772 * the EXT4_MB_STRICT_CHECK case, we need to fake out sparse in this 2773 * function using __acquire and __release. This means we need to be 2774 * super careful before messing with the error path handling via "goto 2775 * out"! 2776 */ 2777static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac, 2778 ext4_group_t group, enum criteria cr) 2779{ 2780 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); 2781 struct super_block *sb = ac->ac_sb; 2782 struct ext4_sb_info *sbi = EXT4_SB(sb); 2783 bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK; 2784 ext4_grpblk_t free; 2785 int ret = 0; 2786 2787 if (!grp) 2788 return -EFSCORRUPTED; 2789 if (sbi->s_mb_stats) 2790 atomic64_inc(&sbi->s_bal_cX_groups_considered[ac->ac_criteria]); 2791 if (should_lock) { 2792 ext4_lock_group(sb, group); 2793 __release(ext4_group_lock_ptr(sb, group)); 2794 } 2795 free = grp->bb_free; 2796 if (free == 0) 2797 goto out; 2798 /* 2799 * In all criterias except CR_ANY_FREE we try to avoid groups that 2800 * can't possibly satisfy the full goal request due to insufficient 2801 * free blocks. 2802 */ 2803 if (cr < CR_ANY_FREE && free < ac->ac_g_ex.fe_len) 2804 goto out; 2805 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) 2806 goto out; 2807 if (should_lock) { 2808 __acquire(ext4_group_lock_ptr(sb, group)); 2809 ext4_unlock_group(sb, group); 2810 } 2811 2812 /* We only do this if the grp has never been initialized */ 2813 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { 2814 struct ext4_group_desc *gdp = 2815 ext4_get_group_desc(sb, group, NULL); 2816 int ret; 2817 2818 /* 2819 * CR_POWER2_ALIGNED/CR_GOAL_LEN_FAST is a very optimistic 2820 * search to find large good chunks almost for free. If buddy 2821 * data is not ready, then this optimization makes no sense. But 2822 * we never skip the first block group in a flex_bg, since this 2823 * gets used for metadata block allocation, and we want to make 2824 * sure we locate metadata blocks in the first block group in 2825 * the flex_bg if possible. 2826 */ 2827 if (!ext4_mb_cr_expensive(cr) && 2828 (!sbi->s_log_groups_per_flex || 2829 ((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) && 2830 !(ext4_has_group_desc_csum(sb) && 2831 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) 2832 return 0; 2833 ret = ext4_mb_init_group(sb, group, GFP_NOFS); 2834 if (ret) 2835 return ret; 2836 } 2837 2838 if (should_lock) { 2839 ext4_lock_group(sb, group); 2840 __release(ext4_group_lock_ptr(sb, group)); 2841 } 2842 ret = ext4_mb_good_group(ac, group, cr); 2843out: 2844 if (should_lock) { 2845 __acquire(ext4_group_lock_ptr(sb, group)); 2846 ext4_unlock_group(sb, group); 2847 } 2848 return ret; 2849} 2850 2851/* 2852 * Start prefetching @nr block bitmaps starting at @group. 2853 * Return the next group which needs to be prefetched. 2854 */ 2855ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group, 2856 unsigned int nr, int *cnt) 2857{ 2858 ext4_group_t ngroups = ext4_get_groups_count(sb); 2859 struct buffer_head *bh; 2860 struct blk_plug plug; 2861 2862 blk_start_plug(&plug); 2863 while (nr-- > 0) { 2864 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, 2865 NULL); 2866 struct ext4_group_info *grp = ext4_get_group_info(sb, group); 2867 2868 /* 2869 * Prefetch block groups with free blocks; but don't 2870 * bother if it is marked uninitialized on disk, since 2871 * it won't require I/O to read. Also only try to 2872 * prefetch once, so we avoid getblk() call, which can 2873 * be expensive. 2874 */ 2875 if (gdp && grp && !EXT4_MB_GRP_TEST_AND_SET_READ(grp) && 2876 EXT4_MB_GRP_NEED_INIT(grp) && 2877 ext4_free_group_clusters(sb, gdp) > 0 ) { 2878 bh = ext4_read_block_bitmap_nowait(sb, group, true); 2879 if (bh && !IS_ERR(bh)) { 2880 if (!buffer_uptodate(bh) && cnt) 2881 (*cnt)++; 2882 brelse(bh); 2883 } 2884 } 2885 if (++group >= ngroups) 2886 group = 0; 2887 } 2888 blk_finish_plug(&plug); 2889 return group; 2890} 2891 2892/* 2893 * Batch reads of the block allocation bitmaps to get 2894 * multiple READs in flight; limit prefetching at inexpensive 2895 * CR, otherwise mballoc can spend a lot of time loading 2896 * imperfect groups 2897 */ 2898static void ext4_mb_might_prefetch(struct ext4_allocation_context *ac, 2899 ext4_group_t group) 2900{ 2901 struct ext4_sb_info *sbi; 2902 2903 if (ac->ac_prefetch_grp != group) 2904 return; 2905 2906 sbi = EXT4_SB(ac->ac_sb); 2907 if (ext4_mb_cr_expensive(ac->ac_criteria) || 2908 ac->ac_prefetch_ios < sbi->s_mb_prefetch_limit) { 2909 unsigned int nr = sbi->s_mb_prefetch; 2910 2911 if (ext4_has_feature_flex_bg(ac->ac_sb)) { 2912 nr = 1 << sbi->s_log_groups_per_flex; 2913 nr -= group & (nr - 1); 2914 nr = umin(nr, sbi->s_mb_prefetch); 2915 } 2916 2917 ac->ac_prefetch_nr = nr; 2918 ac->ac_prefetch_grp = ext4_mb_prefetch(ac->ac_sb, group, nr, 2919 &ac->ac_prefetch_ios); 2920 } 2921} 2922 2923/* 2924 * Prefetching reads the block bitmap into the buffer cache; but we 2925 * need to make sure that the buddy bitmap in the page cache has been 2926 * initialized. Note that ext4_mb_init_group() will block if the I/O 2927 * is not yet completed, or indeed if it was not initiated by 2928 * ext4_mb_prefetch did not start the I/O. 2929 * 2930 * TODO: We should actually kick off the buddy bitmap setup in a work 2931 * queue when the buffer I/O is completed, so that we don't block 2932 * waiting for the block allocation bitmap read to finish when 2933 * ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator(). 2934 */ 2935void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group, 2936 unsigned int nr) 2937{ 2938 struct ext4_group_desc *gdp; 2939 struct ext4_group_info *grp; 2940 2941 while (nr-- > 0) { 2942 if (!group) 2943 group = ext4_get_groups_count(sb); 2944 group--; 2945 gdp = ext4_get_group_desc(sb, group, NULL); 2946 grp = ext4_get_group_info(sb, group); 2947 2948 if (grp && gdp && EXT4_MB_GRP_NEED_INIT(grp) && 2949 ext4_free_group_clusters(sb, gdp) > 0) { 2950 if (ext4_mb_init_group(sb, group, GFP_NOFS)) 2951 break; 2952 } 2953 } 2954} 2955 2956static int ext4_mb_scan_group(struct ext4_allocation_context *ac, 2957 ext4_group_t group) 2958{ 2959 int ret; 2960 struct super_block *sb = ac->ac_sb; 2961 enum criteria cr = ac->ac_criteria; 2962 2963 ext4_mb_might_prefetch(ac, group); 2964 2965 /* prevent unnecessary buddy loading. */ 2966 if (cr < CR_ANY_FREE && spin_is_locked(ext4_group_lock_ptr(sb, group))) 2967 return 0; 2968 2969 /* This now checks without needing the buddy folio */ 2970 ret = ext4_mb_good_group_nolock(ac, group, cr); 2971 if (ret <= 0) { 2972 if (!ac->ac_first_err) 2973 ac->ac_first_err = ret; 2974 return 0; 2975 } 2976 2977 ret = ext4_mb_load_buddy(sb, group, ac->ac_e4b); 2978 if (ret) 2979 return ret; 2980 2981 /* skip busy group */ 2982 if (cr >= CR_ANY_FREE) 2983 ext4_lock_group(sb, group); 2984 else if (!ext4_try_lock_group(sb, group)) 2985 goto out_unload; 2986 2987 /* We need to check again after locking the block group. */ 2988 if (unlikely(!ext4_mb_good_group(ac, group, cr))) 2989 goto out_unlock; 2990 2991 __ext4_mb_scan_group(ac); 2992 2993out_unlock: 2994 ext4_unlock_group(sb, group); 2995out_unload: 2996 ext4_mb_unload_buddy(ac->ac_e4b); 2997 return ret; 2998} 2999 3000static noinline_for_stack int 3001ext4_mb_regular_allocator(struct ext4_allocation_context *ac) 3002{ 3003 ext4_group_t i; 3004 int err = 0; 3005 struct super_block *sb = ac->ac_sb; 3006 struct ext4_sb_info *sbi = EXT4_SB(sb); 3007 struct ext4_buddy e4b; 3008 3009 BUG_ON(ac->ac_status == AC_STATUS_FOUND); 3010 3011 /* first, try the goal */ 3012 err = ext4_mb_find_by_goal(ac, &e4b); 3013 if (err || ac->ac_status == AC_STATUS_FOUND) 3014 goto out; 3015 3016 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) 3017 goto out; 3018 3019 /* 3020 * ac->ac_2order is set only if the fe_len is a power of 2 3021 * if ac->ac_2order is set we also set criteria to CR_POWER2_ALIGNED 3022 * so that we try exact allocation using buddy. 3023 */ 3024 i = fls(ac->ac_g_ex.fe_len); 3025 ac->ac_2order = 0; 3026 /* 3027 * We search using buddy data only if the order of the request 3028 * is greater than equal to the sbi_s_mb_order2_reqs 3029 * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req 3030 * We also support searching for power-of-two requests only for 3031 * requests upto maximum buddy size we have constructed. 3032 */ 3033 if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) { 3034 if (is_power_of_2(ac->ac_g_ex.fe_len)) 3035 ac->ac_2order = array_index_nospec(i - 1, 3036 MB_NUM_ORDERS(sb)); 3037 } 3038 3039 /* if stream allocation is enabled, use global goal */ 3040 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { 3041 int hash = ac->ac_inode->i_ino % sbi->s_mb_nr_global_goals; 3042 3043 ac->ac_g_ex.fe_group = READ_ONCE(sbi->s_mb_last_groups[hash]); 3044 ac->ac_g_ex.fe_start = -1; 3045 ac->ac_flags &= ~EXT4_MB_HINT_TRY_GOAL; 3046 } 3047 3048 /* 3049 * Let's just scan groups to find more-less suitable blocks We 3050 * start with CR_GOAL_LEN_FAST, unless it is power of 2 3051 * aligned, in which case let's do that faster approach first. 3052 */ 3053 ac->ac_criteria = CR_GOAL_LEN_FAST; 3054 if (ac->ac_2order) 3055 ac->ac_criteria = CR_POWER2_ALIGNED; 3056 3057 ac->ac_e4b = &e4b; 3058 ac->ac_prefetch_ios = 0; 3059 ac->ac_first_err = 0; 3060repeat: 3061 while (ac->ac_criteria < EXT4_MB_NUM_CRS) { 3062 err = ext4_mb_scan_groups(ac); 3063 if (err) 3064 goto out; 3065 3066 if (ac->ac_status != AC_STATUS_CONTINUE) 3067 break; 3068 } 3069 3070 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && 3071 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { 3072 /* 3073 * We've been searching too long. Let's try to allocate 3074 * the best chunk we've found so far 3075 */ 3076 ext4_mb_try_best_found(ac, &e4b); 3077 if (ac->ac_status != AC_STATUS_FOUND) { 3078 int lost; 3079 3080 /* 3081 * Someone more lucky has already allocated it. 3082 * The only thing we can do is just take first 3083 * found block(s) 3084 */ 3085 lost = atomic_inc_return(&sbi->s_mb_lost_chunks); 3086 mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n", 3087 ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start, 3088 ac->ac_b_ex.fe_len, lost); 3089 3090 ac->ac_b_ex.fe_group = 0; 3091 ac->ac_b_ex.fe_start = 0; 3092 ac->ac_b_ex.fe_len = 0; 3093 ac->ac_status = AC_STATUS_CONTINUE; 3094 ac->ac_flags |= EXT4_MB_HINT_FIRST; 3095 ac->ac_criteria = CR_ANY_FREE; 3096 goto repeat; 3097 } 3098 } 3099 3100 if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND) { 3101 atomic64_inc(&sbi->s_bal_cX_hits[ac->ac_criteria]); 3102 if (ac->ac_flags & EXT4_MB_STREAM_ALLOC && 3103 ac->ac_b_ex.fe_group == ac->ac_g_ex.fe_group) 3104 atomic_inc(&sbi->s_bal_stream_goals); 3105 } 3106out: 3107 if (!err && ac->ac_status != AC_STATUS_FOUND && ac->ac_first_err) 3108 err = ac->ac_first_err; 3109 3110 mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n", 3111 ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status, 3112 ac->ac_flags, ac->ac_criteria, err); 3113 3114 if (ac->ac_prefetch_nr) 3115 ext4_mb_prefetch_fini(sb, ac->ac_prefetch_grp, ac->ac_prefetch_nr); 3116 3117 return err; 3118} 3119 3120static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) 3121{ 3122 struct super_block *sb = pde_data(file_inode(seq->file)); 3123 ext4_group_t group; 3124 3125 if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) 3126 return NULL; 3127 group = *pos + 1; 3128 return (void *) ((unsigned long) group); 3129} 3130 3131static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) 3132{ 3133 struct super_block *sb = pde_data(file_inode(seq->file)); 3134 ext4_group_t group; 3135 3136 ++*pos; 3137 if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) 3138 return NULL; 3139 group = *pos + 1; 3140 return (void *) ((unsigned long) group); 3141} 3142 3143static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) 3144{ 3145 struct super_block *sb = pde_data(file_inode(seq->file)); 3146 ext4_group_t group = (ext4_group_t) ((unsigned long) v); 3147 int i, err; 3148 char nbuf[16]; 3149 struct ext4_buddy e4b; 3150 struct ext4_group_info *grinfo; 3151 unsigned char blocksize_bits = min_t(unsigned char, 3152 sb->s_blocksize_bits, 3153 EXT4_MAX_BLOCK_LOG_SIZE); 3154 DEFINE_RAW_FLEX(struct ext4_group_info, sg, bb_counters, 3155 EXT4_MAX_BLOCK_LOG_SIZE + 2); 3156 3157 group--; 3158 if (group == 0) 3159 seq_puts(seq, "#group: free frags first [" 3160 " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 " 3161 " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n"); 3162 3163 i = (blocksize_bits + 2) * sizeof(sg->bb_counters[0]) + 3164 sizeof(struct ext4_group_info); 3165 3166 grinfo = ext4_get_group_info(sb, group); 3167 if (!grinfo) 3168 return 0; 3169 /* Load the group info in memory only if not already loaded. */ 3170 if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) { 3171 err = ext4_mb_load_buddy(sb, group, &e4b); 3172 if (err) { 3173 seq_printf(seq, "#%-5u: %s\n", group, ext4_decode_error(NULL, err, nbuf)); 3174 return 0; 3175 } 3176 ext4_mb_unload_buddy(&e4b); 3177 } 3178 3179 /* 3180 * We care only about free space counters in the group info and 3181 * these are safe to access even after the buddy has been unloaded 3182 */ 3183 memcpy(sg, grinfo, i); 3184 seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg->bb_free, 3185 sg->bb_fragments, sg->bb_first_free); 3186 for (i = 0; i <= 13; i++) 3187 seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ? 3188 sg->bb_counters[i] : 0); 3189 seq_puts(seq, " ]"); 3190 if (EXT4_MB_GRP_BBITMAP_CORRUPT(sg)) 3191 seq_puts(seq, " Block bitmap corrupted!"); 3192 seq_putc(seq, '\n'); 3193 return 0; 3194} 3195 3196static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v) 3197{ 3198} 3199 3200const struct seq_operations ext4_mb_seq_groups_ops = { 3201 .start = ext4_mb_seq_groups_start, 3202 .next = ext4_mb_seq_groups_next, 3203 .stop = ext4_mb_seq_groups_stop, 3204 .show = ext4_mb_seq_groups_show, 3205}; 3206 3207int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset) 3208{ 3209 struct super_block *sb = seq->private; 3210 struct ext4_sb_info *sbi = EXT4_SB(sb); 3211 3212 seq_puts(seq, "mballoc:\n"); 3213 if (!sbi->s_mb_stats) { 3214 seq_puts(seq, "\tmb stats collection turned off.\n"); 3215 seq_puts( 3216 seq, 3217 "\tTo enable, please write \"1\" to sysfs file mb_stats.\n"); 3218 return 0; 3219 } 3220 seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs)); 3221 seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success)); 3222 3223 seq_printf(seq, "\tgroups_scanned: %u\n", 3224 atomic_read(&sbi->s_bal_groups_scanned)); 3225 3226 /* CR_POWER2_ALIGNED stats */ 3227 seq_puts(seq, "\tcr_p2_aligned_stats:\n"); 3228 seq_printf(seq, "\t\thits: %llu\n", 3229 atomic64_read(&sbi->s_bal_cX_hits[CR_POWER2_ALIGNED])); 3230 seq_printf( 3231 seq, "\t\tgroups_considered: %llu\n", 3232 atomic64_read( 3233 &sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED])); 3234 seq_printf(seq, "\t\textents_scanned: %u\n", 3235 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_POWER2_ALIGNED])); 3236 seq_printf(seq, "\t\tuseless_loops: %llu\n", 3237 atomic64_read(&sbi->s_bal_cX_failed[CR_POWER2_ALIGNED])); 3238 3239 /* CR_GOAL_LEN_FAST stats */ 3240 seq_puts(seq, "\tcr_goal_fast_stats:\n"); 3241 seq_printf(seq, "\t\thits: %llu\n", 3242 atomic64_read(&sbi->s_bal_cX_hits[CR_GOAL_LEN_FAST])); 3243 seq_printf(seq, "\t\tgroups_considered: %llu\n", 3244 atomic64_read( 3245 &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_FAST])); 3246 seq_printf(seq, "\t\textents_scanned: %u\n", 3247 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_FAST])); 3248 seq_printf(seq, "\t\tuseless_loops: %llu\n", 3249 atomic64_read(&sbi->s_bal_cX_failed[CR_GOAL_LEN_FAST])); 3250 3251 /* CR_BEST_AVAIL_LEN stats */ 3252 seq_puts(seq, "\tcr_best_avail_stats:\n"); 3253 seq_printf(seq, "\t\thits: %llu\n", 3254 atomic64_read(&sbi->s_bal_cX_hits[CR_BEST_AVAIL_LEN])); 3255 seq_printf( 3256 seq, "\t\tgroups_considered: %llu\n", 3257 atomic64_read( 3258 &sbi->s_bal_cX_groups_considered[CR_BEST_AVAIL_LEN])); 3259 seq_printf(seq, "\t\textents_scanned: %u\n", 3260 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_BEST_AVAIL_LEN])); 3261 seq_printf(seq, "\t\tuseless_loops: %llu\n", 3262 atomic64_read(&sbi->s_bal_cX_failed[CR_BEST_AVAIL_LEN])); 3263 3264 /* CR_GOAL_LEN_SLOW stats */ 3265 seq_puts(seq, "\tcr_goal_slow_stats:\n"); 3266 seq_printf(seq, "\t\thits: %llu\n", 3267 atomic64_read(&sbi->s_bal_cX_hits[CR_GOAL_LEN_SLOW])); 3268 seq_printf(seq, "\t\tgroups_considered: %llu\n", 3269 atomic64_read( 3270 &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_SLOW])); 3271 seq_printf(seq, "\t\textents_scanned: %u\n", 3272 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_SLOW])); 3273 seq_printf(seq, "\t\tuseless_loops: %llu\n", 3274 atomic64_read(&sbi->s_bal_cX_failed[CR_GOAL_LEN_SLOW])); 3275 3276 /* CR_ANY_FREE stats */ 3277 seq_puts(seq, "\tcr_any_free_stats:\n"); 3278 seq_printf(seq, "\t\thits: %llu\n", 3279 atomic64_read(&sbi->s_bal_cX_hits[CR_ANY_FREE])); 3280 seq_printf( 3281 seq, "\t\tgroups_considered: %llu\n", 3282 atomic64_read(&sbi->s_bal_cX_groups_considered[CR_ANY_FREE])); 3283 seq_printf(seq, "\t\textents_scanned: %u\n", 3284 atomic_read(&sbi->s_bal_cX_ex_scanned[CR_ANY_FREE])); 3285 seq_printf(seq, "\t\tuseless_loops: %llu\n", 3286 atomic64_read(&sbi->s_bal_cX_failed[CR_ANY_FREE])); 3287 3288 /* Aggregates */ 3289 seq_printf(seq, "\textents_scanned: %u\n", 3290 atomic_read(&sbi->s_bal_ex_scanned)); 3291 seq_printf(seq, "\t\tgoal_hits: %u\n", atomic_read(&sbi->s_bal_goals)); 3292 seq_printf(seq, "\t\tstream_goal_hits: %u\n", 3293 atomic_read(&sbi->s_bal_stream_goals)); 3294 seq_printf(seq, "\t\tlen_goal_hits: %u\n", 3295 atomic_read(&sbi->s_bal_len_goals)); 3296 seq_printf(seq, "\t\t2^n_hits: %u\n", atomic_read(&sbi->s_bal_2orders)); 3297 seq_printf(seq, "\t\tbreaks: %u\n", atomic_read(&sbi->s_bal_breaks)); 3298 seq_printf(seq, "\t\tlost: %u\n", atomic_read(&sbi->s_mb_lost_chunks)); 3299 seq_printf(seq, "\tbuddies_generated: %u/%u\n", 3300 atomic_read(&sbi->s_mb_buddies_generated), 3301 ext4_get_groups_count(sb)); 3302 seq_printf(seq, "\tbuddies_time_used: %llu\n", 3303 atomic64_read(&sbi->s_mb_generation_time)); 3304 seq_printf(seq, "\tpreallocated: %u\n", 3305 atomic_read(&sbi->s_mb_preallocated)); 3306 seq_printf(seq, "\tdiscarded: %u\n", atomic_read(&sbi->s_mb_discarded)); 3307 return 0; 3308} 3309 3310static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos) 3311{ 3312 struct super_block *sb = pde_data(file_inode(seq->file)); 3313 unsigned long position; 3314 3315 if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb)) 3316 return NULL; 3317 position = *pos + 1; 3318 return (void *) ((unsigned long) position); 3319} 3320 3321static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos) 3322{ 3323 struct super_block *sb = pde_data(file_inode(seq->file)); 3324 unsigned long position; 3325 3326 ++*pos; 3327 if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb)) 3328 return NULL; 3329 position = *pos + 1; 3330 return (void *) ((unsigned long) position); 3331} 3332 3333static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v) 3334{ 3335 struct super_block *sb = pde_data(file_inode(seq->file)); 3336 struct ext4_sb_info *sbi = EXT4_SB(sb); 3337 unsigned long position = ((unsigned long) v); 3338 struct ext4_group_info *grp; 3339 unsigned int count; 3340 unsigned long idx; 3341 3342 position--; 3343 if (position >= MB_NUM_ORDERS(sb)) { 3344 position -= MB_NUM_ORDERS(sb); 3345 if (position == 0) 3346 seq_puts(seq, "avg_fragment_size_lists:\n"); 3347 3348 count = 0; 3349 xa_for_each(&sbi->s_mb_avg_fragment_size[position], idx, grp) 3350 count++; 3351 seq_printf(seq, "\tlist_order_%u_groups: %u\n", 3352 (unsigned int)position, count); 3353 return 0; 3354 } 3355 3356 if (position == 0) { 3357 seq_printf(seq, "optimize_scan: %d\n", 3358 test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0); 3359 seq_puts(seq, "max_free_order_lists:\n"); 3360 } 3361 count = 0; 3362 xa_for_each(&sbi->s_mb_largest_free_orders[position], idx, grp) 3363 count++; 3364 seq_printf(seq, "\tlist_order_%u_groups: %u\n", 3365 (unsigned int)position, count); 3366 3367 return 0; 3368} 3369 3370static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v) 3371{ 3372} 3373 3374const struct seq_operations ext4_mb_seq_structs_summary_ops = { 3375 .start = ext4_mb_seq_structs_summary_start, 3376 .next = ext4_mb_seq_structs_summary_next, 3377 .stop = ext4_mb_seq_structs_summary_stop, 3378 .show = ext4_mb_seq_structs_summary_show, 3379}; 3380 3381static struct kmem_cache *get_groupinfo_cache(int blocksize_bits) 3382{ 3383 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; 3384 struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index]; 3385 3386 BUG_ON(!cachep); 3387 return cachep; 3388} 3389 3390/* 3391 * Allocate the top-level s_group_info array for the specified number 3392 * of groups 3393 */ 3394int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups) 3395{ 3396 struct ext4_sb_info *sbi = EXT4_SB(sb); 3397 unsigned size; 3398 struct ext4_group_info ***old_groupinfo, ***new_groupinfo; 3399 3400 size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >> 3401 EXT4_DESC_PER_BLOCK_BITS(sb); 3402 if (size <= sbi->s_group_info_size) 3403 return 0; 3404 3405 size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size); 3406 new_groupinfo = kvzalloc(size, GFP_KERNEL); 3407 if (!new_groupinfo) { 3408 ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group"); 3409 return -ENOMEM; 3410 } 3411 rcu_read_lock(); 3412 old_groupinfo = rcu_dereference(sbi->s_group_info); 3413 if (old_groupinfo) 3414 memcpy(new_groupinfo, old_groupinfo, 3415 sbi->s_group_info_size * sizeof(*sbi->s_group_info)); 3416 rcu_read_unlock(); 3417 rcu_assign_pointer(sbi->s_group_info, new_groupinfo); 3418 sbi->s_group_info_size = size / sizeof(*sbi->s_group_info); 3419 if (old_groupinfo) 3420 ext4_kvfree_array_rcu(old_groupinfo); 3421 ext4_debug("allocated s_groupinfo array for %d meta_bg's\n", 3422 sbi->s_group_info_size); 3423 return 0; 3424} 3425 3426/* Create and initialize ext4_group_info data for the given group. */ 3427int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group, 3428 struct ext4_group_desc *desc) 3429{ 3430 int i; 3431 int metalen = 0; 3432 int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb); 3433 struct ext4_sb_info *sbi = EXT4_SB(sb); 3434 struct ext4_group_info **meta_group_info; 3435 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); 3436 3437 /* 3438 * First check if this group is the first of a reserved block. 3439 * If it's true, we have to allocate a new table of pointers 3440 * to ext4_group_info structures 3441 */ 3442 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { 3443 metalen = sizeof(*meta_group_info) << 3444 EXT4_DESC_PER_BLOCK_BITS(sb); 3445 meta_group_info = kmalloc(metalen, GFP_NOFS); 3446 if (meta_group_info == NULL) { 3447 ext4_msg(sb, KERN_ERR, "can't allocate mem " 3448 "for a buddy group"); 3449 return -ENOMEM; 3450 } 3451 rcu_read_lock(); 3452 rcu_dereference(sbi->s_group_info)[idx] = meta_group_info; 3453 rcu_read_unlock(); 3454 } 3455 3456 meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx); 3457 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1); 3458 3459 meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS); 3460 if (meta_group_info[i] == NULL) { 3461 ext4_msg(sb, KERN_ERR, "can't allocate buddy mem"); 3462 goto exit_group_info; 3463 } 3464 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, 3465 &(meta_group_info[i]->bb_state)); 3466 3467 /* 3468 * initialize bb_free to be able to skip 3469 * empty groups without initialization 3470 */ 3471 if (ext4_has_group_desc_csum(sb) && 3472 (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { 3473 meta_group_info[i]->bb_free = 3474 ext4_free_clusters_after_init(sb, group, desc); 3475 } else { 3476 meta_group_info[i]->bb_free = 3477 ext4_free_group_clusters(sb, desc); 3478 } 3479 3480 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list); 3481 init_rwsem(&meta_group_info[i]->alloc_sem); 3482 meta_group_info[i]->bb_free_root = RB_ROOT; 3483 meta_group_info[i]->bb_largest_free_order = -1; /* uninit */ 3484 meta_group_info[i]->bb_avg_fragment_size_order = -1; /* uninit */ 3485 meta_group_info[i]->bb_group = group; 3486 3487 mb_group_bb_bitmap_alloc(sb, meta_group_info[i], group); 3488 return 0; 3489 3490exit_group_info: 3491 /* If a meta_group_info table has been allocated, release it now */ 3492 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { 3493 struct ext4_group_info ***group_info; 3494 3495 rcu_read_lock(); 3496 group_info = rcu_dereference(sbi->s_group_info); 3497 kfree(group_info[idx]); 3498 group_info[idx] = NULL; 3499 rcu_read_unlock(); 3500 } 3501 return -ENOMEM; 3502} /* ext4_mb_add_groupinfo */ 3503 3504static int ext4_mb_init_backend(struct super_block *sb) 3505{ 3506 ext4_group_t ngroups = ext4_get_groups_count(sb); 3507 ext4_group_t i; 3508 struct ext4_sb_info *sbi = EXT4_SB(sb); 3509 int err; 3510 struct ext4_group_desc *desc; 3511 struct ext4_group_info ***group_info; 3512 struct kmem_cache *cachep; 3513 3514 err = ext4_mb_alloc_groupinfo(sb, ngroups); 3515 if (err) 3516 return err; 3517 3518 sbi->s_buddy_cache = new_inode(sb); 3519 if (sbi->s_buddy_cache == NULL) { 3520 ext4_msg(sb, KERN_ERR, "can't get new inode"); 3521 goto err_freesgi; 3522 } 3523 /* To avoid potentially colliding with an valid on-disk inode number, 3524 * use EXT4_BAD_INO for the buddy cache inode number. This inode is 3525 * not in the inode hash, so it should never be found by iget(), but 3526 * this will avoid confusion if it ever shows up during debugging. */ 3527 sbi->s_buddy_cache->i_ino = EXT4_BAD_INO; 3528 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; 3529 ext4_set_inode_mapping_order(sbi->s_buddy_cache); 3530 3531 for (i = 0; i < ngroups; i++) { 3532 cond_resched(); 3533 desc = ext4_get_group_desc(sb, i, NULL); 3534 if (desc == NULL) { 3535 ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i); 3536 goto err_freebuddy; 3537 } 3538 if (ext4_mb_add_groupinfo(sb, i, desc) != 0) 3539 goto err_freebuddy; 3540 } 3541 3542 if (ext4_has_feature_flex_bg(sb)) { 3543 /* a single flex group is supposed to be read by a single IO. 3544 * 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is 3545 * unsigned integer, so the maximum shift is 32. 3546 */ 3547 if (sbi->s_es->s_log_groups_per_flex >= 32) { 3548 ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group"); 3549 goto err_freebuddy; 3550 } 3551 sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex, 3552 BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9)); 3553 sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */ 3554 } else { 3555 sbi->s_mb_prefetch = 32; 3556 } 3557 if (sbi->s_mb_prefetch > ext4_get_groups_count(sb)) 3558 sbi->s_mb_prefetch = ext4_get_groups_count(sb); 3559 /* 3560 * now many real IOs to prefetch within a single allocation at 3561 * CR_POWER2_ALIGNED. Given CR_POWER2_ALIGNED is an CPU-related 3562 * optimization we shouldn't try to load too many groups, at some point 3563 * we should start to use what we've got in memory. 3564 * with an average random access time 5ms, it'd take a second to get 3565 * 200 groups (* N with flex_bg), so let's make this limit 4 3566 */ 3567 sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4; 3568 if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb)) 3569 sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb); 3570 3571 return 0; 3572 3573err_freebuddy: 3574 cachep = get_groupinfo_cache(sb->s_blocksize_bits); 3575 while (i-- > 0) { 3576 struct ext4_group_info *grp = ext4_get_group_info(sb, i); 3577 3578 if (grp) 3579 kmem_cache_free(cachep, grp); 3580 } 3581 i = sbi->s_group_info_size; 3582 rcu_read_lock(); 3583 group_info = rcu_dereference(sbi->s_group_info); 3584 while (i-- > 0) 3585 kfree(group_info[i]); 3586 rcu_read_unlock(); 3587 iput(sbi->s_buddy_cache); 3588err_freesgi: 3589 kvfree(rcu_access_pointer(sbi->s_group_info)); 3590 return -ENOMEM; 3591} 3592 3593static void ext4_groupinfo_destroy_slabs(void) 3594{ 3595 int i; 3596 3597 for (i = 0; i < NR_GRPINFO_CACHES; i++) { 3598 kmem_cache_destroy(ext4_groupinfo_caches[i]); 3599 ext4_groupinfo_caches[i] = NULL; 3600 } 3601} 3602 3603static int ext4_groupinfo_create_slab(size_t size) 3604{ 3605 static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex); 3606 int slab_size; 3607 int blocksize_bits = order_base_2(size); 3608 int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; 3609 struct kmem_cache *cachep; 3610 3611 if (cache_index >= NR_GRPINFO_CACHES) 3612 return -EINVAL; 3613 3614 if (unlikely(cache_index < 0)) 3615 cache_index = 0; 3616 3617 mutex_lock(&ext4_grpinfo_slab_create_mutex); 3618 if (ext4_groupinfo_caches[cache_index]) { 3619 mutex_unlock(&ext4_grpinfo_slab_create_mutex); 3620 return 0; /* Already created */ 3621 } 3622 3623 slab_size = offsetof(struct ext4_group_info, 3624 bb_counters[blocksize_bits + 2]); 3625 3626 cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index], 3627 slab_size, 0, SLAB_RECLAIM_ACCOUNT, 3628 NULL); 3629 3630 ext4_groupinfo_caches[cache_index] = cachep; 3631 3632 mutex_unlock(&ext4_grpinfo_slab_create_mutex); 3633 if (!cachep) { 3634 printk(KERN_EMERG 3635 "EXT4-fs: no memory for groupinfo slab cache\n"); 3636 return -ENOMEM; 3637 } 3638 3639 return 0; 3640} 3641 3642static void ext4_discard_work(struct work_struct *work) 3643{ 3644 struct ext4_sb_info *sbi = container_of(work, 3645 struct ext4_sb_info, s_discard_work); 3646 struct super_block *sb = sbi->s_sb; 3647 struct ext4_free_data *fd, *nfd; 3648 struct ext4_buddy e4b; 3649 LIST_HEAD(discard_list); 3650 ext4_group_t grp, load_grp; 3651 int err = 0; 3652 3653 spin_lock(&sbi->s_md_lock); 3654 list_splice_init(&sbi->s_discard_list, &discard_list); 3655 spin_unlock(&sbi->s_md_lock); 3656 3657 load_grp = UINT_MAX; 3658 list_for_each_entry_safe(fd, nfd, &discard_list, efd_list) { 3659 /* 3660 * If filesystem is umounting or no memory or suffering 3661 * from no space, give up the discard 3662 */ 3663 if ((sb->s_flags & SB_ACTIVE) && !err && 3664 !atomic_read(&sbi->s_retry_alloc_pending)) { 3665 grp = fd->efd_group; 3666 if (grp != load_grp) { 3667 if (load_grp != UINT_MAX) 3668 ext4_mb_unload_buddy(&e4b); 3669 3670 err = ext4_mb_load_buddy(sb, grp, &e4b); 3671 if (err) { 3672 kmem_cache_free(ext4_free_data_cachep, fd); 3673 load_grp = UINT_MAX; 3674 continue; 3675 } else { 3676 load_grp = grp; 3677 } 3678 } 3679 3680 ext4_lock_group(sb, grp); 3681 ext4_try_to_trim_range(sb, &e4b, fd->efd_start_cluster, 3682 fd->efd_start_cluster + fd->efd_count - 1, 1); 3683 ext4_unlock_group(sb, grp); 3684 } 3685 kmem_cache_free(ext4_free_data_cachep, fd); 3686 } 3687 3688 if (load_grp != UINT_MAX) 3689 ext4_mb_unload_buddy(&e4b); 3690} 3691 3692static inline void ext4_mb_avg_fragment_size_destroy(struct ext4_sb_info *sbi) 3693{ 3694 if (!sbi->s_mb_avg_fragment_size) 3695 return; 3696 3697 for (int i = 0; i < MB_NUM_ORDERS(sbi->s_sb); i++) 3698 xa_destroy(&sbi->s_mb_avg_fragment_size[i]); 3699 3700 kfree(sbi->s_mb_avg_fragment_size); 3701 sbi->s_mb_avg_fragment_size = NULL; 3702} 3703 3704static inline void ext4_mb_largest_free_orders_destroy(struct ext4_sb_info *sbi) 3705{ 3706 if (!sbi->s_mb_largest_free_orders) 3707 return; 3708 3709 for (int i = 0; i < MB_NUM_ORDERS(sbi->s_sb); i++) 3710 xa_destroy(&sbi->s_mb_largest_free_orders[i]); 3711 3712 kfree(sbi->s_mb_largest_free_orders); 3713 sbi->s_mb_largest_free_orders = NULL; 3714} 3715 3716int ext4_mb_init(struct super_block *sb) 3717{ 3718 struct ext4_sb_info *sbi = EXT4_SB(sb); 3719 unsigned i, j; 3720 unsigned offset, offset_incr; 3721 unsigned max; 3722 int ret; 3723 3724 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets); 3725 3726 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL); 3727 if (sbi->s_mb_offsets == NULL) { 3728 ret = -ENOMEM; 3729 goto out; 3730 } 3731 3732 i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs); 3733 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL); 3734 if (sbi->s_mb_maxs == NULL) { 3735 ret = -ENOMEM; 3736 goto out; 3737 } 3738 3739 ret = ext4_groupinfo_create_slab(sb->s_blocksize); 3740 if (ret < 0) 3741 goto out; 3742 3743 /* order 0 is regular bitmap */ 3744 sbi->s_mb_maxs[0] = sb->s_blocksize << 3; 3745 sbi->s_mb_offsets[0] = 0; 3746 3747 i = 1; 3748 offset = 0; 3749 offset_incr = 1 << (sb->s_blocksize_bits - 1); 3750 max = sb->s_blocksize << 2; 3751 do { 3752 sbi->s_mb_offsets[i] = offset; 3753 sbi->s_mb_maxs[i] = max; 3754 offset += offset_incr; 3755 offset_incr = offset_incr >> 1; 3756 max = max >> 1; 3757 i++; 3758 } while (i < MB_NUM_ORDERS(sb)); 3759 3760 sbi->s_mb_avg_fragment_size = 3761 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct xarray), 3762 GFP_KERNEL); 3763 if (!sbi->s_mb_avg_fragment_size) { 3764 ret = -ENOMEM; 3765 goto out; 3766 } 3767 for (i = 0; i < MB_NUM_ORDERS(sb); i++) 3768 xa_init(&sbi->s_mb_avg_fragment_size[i]); 3769 3770 sbi->s_mb_largest_free_orders = 3771 kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct xarray), 3772 GFP_KERNEL); 3773 if (!sbi->s_mb_largest_free_orders) { 3774 ret = -ENOMEM; 3775 goto out; 3776 } 3777 for (i = 0; i < MB_NUM_ORDERS(sb); i++) 3778 xa_init(&sbi->s_mb_largest_free_orders[i]); 3779 3780 spin_lock_init(&sbi->s_md_lock); 3781 atomic_set(&sbi->s_mb_free_pending, 0); 3782 INIT_LIST_HEAD(&sbi->s_freed_data_list[0]); 3783 INIT_LIST_HEAD(&sbi->s_freed_data_list[1]); 3784 INIT_LIST_HEAD(&sbi->s_discard_list); 3785 INIT_WORK(&sbi->s_discard_work, ext4_discard_work); 3786 atomic_set(&sbi->s_retry_alloc_pending, 0); 3787 3788 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; 3789 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; 3790 sbi->s_mb_stats = MB_DEFAULT_STATS; 3791 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD; 3792 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; 3793 sbi->s_mb_best_avail_max_trim_order = MB_DEFAULT_BEST_AVAIL_TRIM_ORDER; 3794 3795 /* 3796 * The default group preallocation is 512, which for 4k block 3797 * sizes translates to 2 megabytes. However for bigalloc file 3798 * systems, this is probably too big (i.e, if the cluster size 3799 * is 1 megabyte, then group preallocation size becomes half a 3800 * gigabyte!). As a default, we will keep a two megabyte 3801 * group pralloc size for cluster sizes up to 64k, and after 3802 * that, we will force a minimum group preallocation size of 3803 * 32 clusters. This translates to 8 megs when the cluster 3804 * size is 256k, and 32 megs when the cluster size is 1 meg, 3805 * which seems reasonable as a default. 3806 */ 3807 sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >> 3808 sbi->s_cluster_bits, 32); 3809 /* 3810 * If there is a s_stripe > 1, then we set the s_mb_group_prealloc 3811 * to the lowest multiple of s_stripe which is bigger than 3812 * the s_mb_group_prealloc as determined above. We want 3813 * the preallocation size to be an exact multiple of the 3814 * RAID stripe size so that preallocations don't fragment 3815 * the stripes. 3816 */ 3817 if (sbi->s_stripe > 1) { 3818 sbi->s_mb_group_prealloc = roundup( 3819 sbi->s_mb_group_prealloc, EXT4_NUM_B2C(sbi, sbi->s_stripe)); 3820 } 3821 3822 sbi->s_mb_nr_global_goals = umin(num_possible_cpus(), 3823 DIV_ROUND_UP(sbi->s_groups_count, 4)); 3824 sbi->s_mb_last_groups = kcalloc(sbi->s_mb_nr_global_goals, 3825 sizeof(ext4_group_t), GFP_KERNEL); 3826 if (sbi->s_mb_last_groups == NULL) { 3827 ret = -ENOMEM; 3828 goto out; 3829 } 3830 3831 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); 3832 if (sbi->s_locality_groups == NULL) { 3833 ret = -ENOMEM; 3834 goto out_free_last_groups; 3835 } 3836 for_each_possible_cpu(i) { 3837 struct ext4_locality_group *lg; 3838 lg = per_cpu_ptr(sbi->s_locality_groups, i); 3839 mutex_init(&lg->lg_mutex); 3840 for (j = 0; j < PREALLOC_TB_SIZE; j++) 3841 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]); 3842 spin_lock_init(&lg->lg_prealloc_lock); 3843 } 3844 3845 if (bdev_nonrot(sb->s_bdev)) 3846 sbi->s_mb_max_linear_groups = 0; 3847 else 3848 sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT; 3849 /* init file for buddy data */ 3850 ret = ext4_mb_init_backend(sb); 3851 if (ret != 0) 3852 goto out_free_locality_groups; 3853 3854 return 0; 3855 3856out_free_locality_groups: 3857 free_percpu(sbi->s_locality_groups); 3858 sbi->s_locality_groups = NULL; 3859out_free_last_groups: 3860 kfree(sbi->s_mb_last_groups); 3861 sbi->s_mb_last_groups = NULL; 3862out: 3863 ext4_mb_avg_fragment_size_destroy(sbi); 3864 ext4_mb_largest_free_orders_destroy(sbi); 3865 kfree(sbi->s_mb_offsets); 3866 sbi->s_mb_offsets = NULL; 3867 kfree(sbi->s_mb_maxs); 3868 sbi->s_mb_maxs = NULL; 3869 return ret; 3870} 3871 3872/* need to called with the ext4 group lock held */ 3873static int ext4_mb_cleanup_pa(struct ext4_group_info *grp) 3874{ 3875 struct ext4_prealloc_space *pa; 3876 struct list_head *cur, *tmp; 3877 int count = 0; 3878 3879 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) { 3880 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); 3881 list_del(&pa->pa_group_list); 3882 count++; 3883 kmem_cache_free(ext4_pspace_cachep, pa); 3884 } 3885 return count; 3886} 3887 3888void ext4_mb_release(struct super_block *sb) 3889{ 3890 ext4_group_t ngroups = ext4_get_groups_count(sb); 3891 ext4_group_t i; 3892 int num_meta_group_infos; 3893 struct ext4_group_info *grinfo, ***group_info; 3894 struct ext4_sb_info *sbi = EXT4_SB(sb); 3895 struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); 3896 int count; 3897 3898 /* 3899 * wait the discard work to drain all of ext4_free_data 3900 */ 3901 flush_work(&sbi->s_discard_work); 3902 WARN_ON_ONCE(!list_empty(&sbi->s_discard_list)); 3903 3904 group_info = rcu_access_pointer(sbi->s_group_info); 3905 if (group_info) { 3906 for (i = 0; i < ngroups; i++) { 3907 cond_resched(); 3908 grinfo = ext4_get_group_info(sb, i); 3909 if (!grinfo) 3910 continue; 3911 mb_group_bb_bitmap_free(grinfo); 3912 ext4_lock_group(sb, i); 3913 count = ext4_mb_cleanup_pa(grinfo); 3914 if (count) 3915 mb_debug(sb, "mballoc: %d PAs left\n", 3916 count); 3917 ext4_unlock_group(sb, i); 3918 kmem_cache_free(cachep, grinfo); 3919 } 3920 num_meta_group_infos = (ngroups + 3921 EXT4_DESC_PER_BLOCK(sb) - 1) >> 3922 EXT4_DESC_PER_BLOCK_BITS(sb); 3923 for (i = 0; i < num_meta_group_infos; i++) 3924 kfree(group_info[i]); 3925 kvfree(group_info); 3926 } 3927 ext4_mb_avg_fragment_size_destroy(sbi); 3928 ext4_mb_largest_free_orders_destroy(sbi); 3929 kfree(sbi->s_mb_offsets); 3930 kfree(sbi->s_mb_maxs); 3931 iput(sbi->s_buddy_cache); 3932 if (sbi->s_mb_stats) { 3933 ext4_msg(sb, KERN_INFO, 3934 "mballoc: %u blocks %u reqs (%u success)", 3935 atomic_read(&sbi->s_bal_allocated), 3936 atomic_read(&sbi->s_bal_reqs), 3937 atomic_read(&sbi->s_bal_success)); 3938 ext4_msg(sb, KERN_INFO, 3939 "mballoc: %u extents scanned, %u groups scanned, %u goal hits, " 3940 "%u 2^N hits, %u breaks, %u lost", 3941 atomic_read(&sbi->s_bal_ex_scanned), 3942 atomic_read(&sbi->s_bal_groups_scanned), 3943 atomic_read(&sbi->s_bal_goals), 3944 atomic_read(&sbi->s_bal_2orders), 3945 atomic_read(&sbi->s_bal_breaks), 3946 atomic_read(&sbi->s_mb_lost_chunks)); 3947 ext4_msg(sb, KERN_INFO, 3948 "mballoc: %u generated and it took %llu", 3949 atomic_read(&sbi->s_mb_buddies_generated), 3950 atomic64_read(&sbi->s_mb_generation_time)); 3951 ext4_msg(sb, KERN_INFO, 3952 "mballoc: %u preallocated, %u discarded", 3953 atomic_read(&sbi->s_mb_preallocated), 3954 atomic_read(&sbi->s_mb_discarded)); 3955 } 3956 3957 free_percpu(sbi->s_locality_groups); 3958 kfree(sbi->s_mb_last_groups); 3959} 3960 3961static inline int ext4_issue_discard(struct super_block *sb, 3962 ext4_group_t block_group, ext4_grpblk_t cluster, int count) 3963{ 3964 ext4_fsblk_t discard_block; 3965 3966 discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) + 3967 ext4_group_first_block_no(sb, block_group)); 3968 count = EXT4_C2B(EXT4_SB(sb), count); 3969 trace_ext4_discard_blocks(sb, 3970 (unsigned long long) discard_block, count); 3971 3972 return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0); 3973} 3974 3975static void ext4_free_data_in_buddy(struct super_block *sb, 3976 struct ext4_free_data *entry) 3977{ 3978 struct ext4_buddy e4b; 3979 struct ext4_group_info *db; 3980 int err, count = 0; 3981 3982 mb_debug(sb, "gonna free %u blocks in group %u (0x%p):", 3983 entry->efd_count, entry->efd_group, entry); 3984 3985 err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b); 3986 /* we expect to find existing buddy because it's pinned */ 3987 BUG_ON(err != 0); 3988 3989 atomic_sub(entry->efd_count, &EXT4_SB(sb)->s_mb_free_pending); 3990 db = e4b.bd_info; 3991 /* there are blocks to put in buddy to make them really free */ 3992 count += entry->efd_count; 3993 ext4_lock_group(sb, entry->efd_group); 3994 /* Take it out of per group rb tree */ 3995 rb_erase(&entry->efd_node, &(db->bb_free_root)); 3996 mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count); 3997 3998 /* 3999 * Clear the trimmed flag for the group so that the next 4000 * ext4_trim_fs can trim it. 4001 */ 4002 EXT4_MB_GRP_CLEAR_TRIMMED(db); 4003 4004 if (!db->bb_free_root.rb_node) { 4005 /* No more items in the per group rb tree 4006 * balance refcounts from ext4_mb_free_metadata() 4007 */ 4008 folio_put(e4b.bd_buddy_folio); 4009 folio_put(e4b.bd_bitmap_folio); 4010 } 4011 ext4_unlock_group(sb, entry->efd_group); 4012 ext4_mb_unload_buddy(&e4b); 4013 4014 mb_debug(sb, "freed %d blocks in 1 structures\n", count); 4015} 4016 4017/* 4018 * This function is called by the jbd2 layer once the commit has finished, 4019 * so we know we can free the blocks that were released with that commit. 4020 */ 4021void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid) 4022{ 4023 struct ext4_sb_info *sbi = EXT4_SB(sb); 4024 struct ext4_free_data *entry, *tmp; 4025 LIST_HEAD(freed_data_list); 4026 struct list_head *s_freed_head = &sbi->s_freed_data_list[commit_tid & 1]; 4027 bool wake; 4028 4029 list_replace_init(s_freed_head, &freed_data_list); 4030 4031 list_for_each_entry(entry, &freed_data_list, efd_list) 4032 ext4_free_data_in_buddy(sb, entry); 4033 4034 if (test_opt(sb, DISCARD)) { 4035 spin_lock(&sbi->s_md_lock); 4036 wake = list_empty(&sbi->s_discard_list); 4037 list_splice_tail(&freed_data_list, &sbi->s_discard_list); 4038 spin_unlock(&sbi->s_md_lock); 4039 if (wake) 4040 queue_work(system_dfl_wq, &sbi->s_discard_work); 4041 } else { 4042 list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list) 4043 kmem_cache_free(ext4_free_data_cachep, entry); 4044 } 4045} 4046 4047int __init ext4_init_mballoc(void) 4048{ 4049 ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space, 4050 SLAB_RECLAIM_ACCOUNT); 4051 if (ext4_pspace_cachep == NULL) 4052 goto out; 4053 4054 ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context, 4055 SLAB_RECLAIM_ACCOUNT); 4056 if (ext4_ac_cachep == NULL) 4057 goto out_pa_free; 4058 4059 ext4_free_data_cachep = KMEM_CACHE(ext4_free_data, 4060 SLAB_RECLAIM_ACCOUNT); 4061 if (ext4_free_data_cachep == NULL) 4062 goto out_ac_free; 4063 4064 return 0; 4065 4066out_ac_free: 4067 kmem_cache_destroy(ext4_ac_cachep); 4068out_pa_free: 4069 kmem_cache_destroy(ext4_pspace_cachep); 4070out: 4071 return -ENOMEM; 4072} 4073 4074void ext4_exit_mballoc(void) 4075{ 4076 /* 4077 * Wait for completion of call_rcu()'s on ext4_pspace_cachep 4078 * before destroying the slab cache. 4079 */ 4080 rcu_barrier(); 4081 kmem_cache_destroy(ext4_pspace_cachep); 4082 kmem_cache_destroy(ext4_ac_cachep); 4083 kmem_cache_destroy(ext4_free_data_cachep); 4084 ext4_groupinfo_destroy_slabs(); 4085} 4086 4087#define EXT4_MB_BITMAP_MARKED_CHECK 0x0001 4088#define EXT4_MB_SYNC_UPDATE 0x0002 4089int 4090ext4_mb_mark_context(handle_t *handle, struct super_block *sb, bool state, 4091 ext4_group_t group, ext4_grpblk_t blkoff, 4092 ext4_grpblk_t len, int flags, ext4_grpblk_t *ret_changed) 4093{ 4094 struct ext4_sb_info *sbi = EXT4_SB(sb); 4095 struct buffer_head *bitmap_bh = NULL; 4096 struct ext4_group_desc *gdp; 4097 struct buffer_head *gdp_bh; 4098 int err; 4099 unsigned int i, already, changed = len; 4100 4101 KUNIT_STATIC_STUB_REDIRECT(ext4_mb_mark_context, 4102 handle, sb, state, group, blkoff, len, 4103 flags, ret_changed); 4104 4105 if (ret_changed) 4106 *ret_changed = 0; 4107 bitmap_bh = ext4_read_block_bitmap(sb, group); 4108 if (IS_ERR(bitmap_bh)) 4109 return PTR_ERR(bitmap_bh); 4110 4111 if (handle) { 4112 BUFFER_TRACE(bitmap_bh, "getting write access"); 4113 err = ext4_journal_get_write_access(handle, sb, bitmap_bh, 4114 EXT4_JTR_NONE); 4115 if (err) 4116 goto out_err; 4117 } 4118 4119 err = -EIO; 4120 gdp = ext4_get_group_desc(sb, group, &gdp_bh); 4121 if (!gdp) 4122 goto out_err; 4123 4124 if (handle) { 4125 BUFFER_TRACE(gdp_bh, "get_write_access"); 4126 err = ext4_journal_get_write_access(handle, sb, gdp_bh, 4127 EXT4_JTR_NONE); 4128 if (err) 4129 goto out_err; 4130 } 4131 4132 ext4_lock_group(sb, group); 4133 if (ext4_has_group_desc_csum(sb) && 4134 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { 4135 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); 4136 ext4_free_group_clusters_set(sb, gdp, 4137 ext4_free_clusters_after_init(sb, group, gdp)); 4138 } 4139 4140 if (flags & EXT4_MB_BITMAP_MARKED_CHECK) { 4141 already = 0; 4142 for (i = 0; i < len; i++) 4143 if (mb_test_bit(blkoff + i, bitmap_bh->b_data) == 4144 state) 4145 already++; 4146 changed = len - already; 4147 } 4148 4149 if (state) { 4150 mb_set_bits(bitmap_bh->b_data, blkoff, len); 4151 ext4_free_group_clusters_set(sb, gdp, 4152 ext4_free_group_clusters(sb, gdp) - changed); 4153 } else { 4154 mb_clear_bits(bitmap_bh->b_data, blkoff, len); 4155 ext4_free_group_clusters_set(sb, gdp, 4156 ext4_free_group_clusters(sb, gdp) + changed); 4157 } 4158 4159 ext4_block_bitmap_csum_set(sb, gdp, bitmap_bh); 4160 ext4_group_desc_csum_set(sb, group, gdp); 4161 ext4_unlock_group(sb, group); 4162 if (ret_changed) 4163 *ret_changed = changed; 4164 4165 if (sbi->s_log_groups_per_flex) { 4166 ext4_group_t flex_group = ext4_flex_group(sbi, group); 4167 struct flex_groups *fg = sbi_array_rcu_deref(sbi, 4168 s_flex_groups, flex_group); 4169 4170 if (state) 4171 atomic64_sub(changed, &fg->free_clusters); 4172 else 4173 atomic64_add(changed, &fg->free_clusters); 4174 } 4175 4176 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); 4177 if (err) 4178 goto out_err; 4179 err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh); 4180 if (err) 4181 goto out_err; 4182 4183 if (flags & EXT4_MB_SYNC_UPDATE) { 4184 sync_dirty_buffer(bitmap_bh); 4185 sync_dirty_buffer(gdp_bh); 4186 } 4187 4188out_err: 4189 brelse(bitmap_bh); 4190 return err; 4191} 4192 4193/* 4194 * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps 4195 * Returns 0 if success or error code 4196 */ 4197static noinline_for_stack int 4198ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, handle_t *handle) 4199{ 4200 struct ext4_group_desc *gdp; 4201 struct ext4_sb_info *sbi; 4202 struct super_block *sb; 4203 ext4_fsblk_t block; 4204 int err, len; 4205 int flags = 0; 4206 ext4_grpblk_t changed; 4207 4208 BUG_ON(ac->ac_status != AC_STATUS_FOUND); 4209 BUG_ON(ac->ac_b_ex.fe_len <= 0); 4210 4211 sb = ac->ac_sb; 4212 sbi = EXT4_SB(sb); 4213 4214 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, NULL); 4215 if (!gdp) 4216 return -EIO; 4217 ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group, 4218 ext4_free_group_clusters(sb, gdp)); 4219 4220 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); 4221 len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len); 4222 if (!ext4_inode_block_valid(ac->ac_inode, block, len)) { 4223 ext4_error(sb, "Allocating blocks %llu-%llu which overlap " 4224 "fs metadata", block, block+len); 4225 /* File system mounted not to panic on error 4226 * Fix the bitmap and return EFSCORRUPTED 4227 * We leak some of the blocks here. 4228 */ 4229 err = ext4_mb_mark_context(handle, sb, true, 4230 ac->ac_b_ex.fe_group, 4231 ac->ac_b_ex.fe_start, 4232 ac->ac_b_ex.fe_len, 4233 0, NULL); 4234 if (!err) 4235 err = -EFSCORRUPTED; 4236 return err; 4237 } 4238 4239#ifdef AGGRESSIVE_CHECK 4240 flags |= EXT4_MB_BITMAP_MARKED_CHECK; 4241#endif 4242 err = ext4_mb_mark_context(handle, sb, true, ac->ac_b_ex.fe_group, 4243 ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len, 4244 flags, &changed); 4245 4246 if (err && changed == 0) 4247 return err; 4248 4249#ifdef AGGRESSIVE_CHECK 4250 BUG_ON(changed != ac->ac_b_ex.fe_len); 4251#endif 4252 percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len); 4253 4254 return err; 4255} 4256 4257/* 4258 * Idempotent helper for Ext4 fast commit replay path to set the state of 4259 * blocks in bitmaps and update counters. 4260 */ 4261void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, 4262 int len, bool state) 4263{ 4264 struct ext4_sb_info *sbi = EXT4_SB(sb); 4265 ext4_group_t group; 4266 ext4_grpblk_t blkoff; 4267 int err = 0; 4268 unsigned int clen, thisgrp_len; 4269 4270 while (len > 0) { 4271 ext4_get_group_no_and_offset(sb, block, &group, &blkoff); 4272 4273 /* 4274 * Check to see if we are freeing blocks across a group 4275 * boundary. 4276 * In case of flex_bg, this can happen that (block, len) may 4277 * span across more than one group. In that case we need to 4278 * get the corresponding group metadata to work with. 4279 * For this we have goto again loop. 4280 */ 4281 thisgrp_len = min_t(unsigned int, (unsigned int)len, 4282 EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff)); 4283 clen = EXT4_NUM_B2C(sbi, thisgrp_len); 4284 4285 if (!ext4_sb_block_valid(sb, NULL, block, thisgrp_len)) { 4286 ext4_error(sb, "Marking blocks in system zone - " 4287 "Block = %llu, len = %u", 4288 block, thisgrp_len); 4289 break; 4290 } 4291 4292 err = ext4_mb_mark_context(NULL, sb, state, 4293 group, blkoff, clen, 4294 EXT4_MB_BITMAP_MARKED_CHECK | 4295 EXT4_MB_SYNC_UPDATE, 4296 NULL); 4297 if (err) 4298 break; 4299 4300 block += thisgrp_len; 4301 len -= thisgrp_len; 4302 BUG_ON(len < 0); 4303 } 4304} 4305 4306/* 4307 * here we normalize request for locality group 4308 * Group request are normalized to s_mb_group_prealloc, which goes to 4309 * s_strip if we set the same via mount option. 4310 * s_mb_group_prealloc can be configured via 4311 * /sys/fs/ext4/<partition>/mb_group_prealloc 4312 * 4313 * XXX: should we try to preallocate more than the group has now? 4314 */ 4315static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) 4316{ 4317 struct super_block *sb = ac->ac_sb; 4318 struct ext4_locality_group *lg = ac->ac_lg; 4319 4320 BUG_ON(lg == NULL); 4321 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; 4322 mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len); 4323} 4324 4325/* 4326 * This function returns the next element to look at during inode 4327 * PA rbtree walk. We assume that we have held the inode PA rbtree lock 4328 * (ei->i_prealloc_lock) 4329 * 4330 * new_start The start of the range we want to compare 4331 * cur_start The existing start that we are comparing against 4332 * node The node of the rb_tree 4333 */ 4334static inline struct rb_node* 4335ext4_mb_pa_rb_next_iter(ext4_lblk_t new_start, ext4_lblk_t cur_start, struct rb_node *node) 4336{ 4337 if (new_start < cur_start) 4338 return node->rb_left; 4339 else 4340 return node->rb_right; 4341} 4342 4343static inline void 4344ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, 4345 ext4_lblk_t start, loff_t end) 4346{ 4347 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 4348 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); 4349 struct ext4_prealloc_space *tmp_pa; 4350 ext4_lblk_t tmp_pa_start; 4351 loff_t tmp_pa_end; 4352 struct rb_node *iter; 4353 4354 read_lock(&ei->i_prealloc_lock); 4355 for (iter = ei->i_prealloc_node.rb_node; iter; 4356 iter = ext4_mb_pa_rb_next_iter(start, tmp_pa_start, iter)) { 4357 tmp_pa = rb_entry(iter, struct ext4_prealloc_space, 4358 pa_node.inode_node); 4359 tmp_pa_start = tmp_pa->pa_lstart; 4360 tmp_pa_end = pa_logical_end(sbi, tmp_pa); 4361 4362 spin_lock(&tmp_pa->pa_lock); 4363 if (tmp_pa->pa_deleted == 0) 4364 BUG_ON(!(start >= tmp_pa_end || end <= tmp_pa_start)); 4365 spin_unlock(&tmp_pa->pa_lock); 4366 } 4367 read_unlock(&ei->i_prealloc_lock); 4368} 4369 4370/* 4371 * Given an allocation context "ac" and a range "start", "end", check 4372 * and adjust boundaries if the range overlaps with any of the existing 4373 * preallocatoins stored in the corresponding inode of the allocation context. 4374 * 4375 * Parameters: 4376 * ac allocation context 4377 * start start of the new range 4378 * end end of the new range 4379 */ 4380static inline void 4381ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, 4382 ext4_lblk_t *start, loff_t *end) 4383{ 4384 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); 4385 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 4386 struct ext4_prealloc_space *tmp_pa = NULL, *left_pa = NULL, *right_pa = NULL; 4387 struct rb_node *iter; 4388 ext4_lblk_t new_start, tmp_pa_start, right_pa_start = -1; 4389 loff_t new_end, tmp_pa_end, left_pa_end = -1; 4390 4391 new_start = *start; 4392 new_end = *end; 4393 4394 /* 4395 * Adjust the normalized range so that it doesn't overlap with any 4396 * existing preallocated blocks(PAs). Make sure to hold the rbtree lock 4397 * so it doesn't change underneath us. 4398 */ 4399 read_lock(&ei->i_prealloc_lock); 4400 4401 /* Step 1: find any one immediate neighboring PA of the normalized range */ 4402 for (iter = ei->i_prealloc_node.rb_node; iter; 4403 iter = ext4_mb_pa_rb_next_iter(ac->ac_o_ex.fe_logical, 4404 tmp_pa_start, iter)) { 4405 tmp_pa = rb_entry(iter, struct ext4_prealloc_space, 4406 pa_node.inode_node); 4407 tmp_pa_start = tmp_pa->pa_lstart; 4408 tmp_pa_end = pa_logical_end(sbi, tmp_pa); 4409 4410 /* PA must not overlap original request */ 4411 spin_lock(&tmp_pa->pa_lock); 4412 if (tmp_pa->pa_deleted == 0) 4413 BUG_ON(!(ac->ac_o_ex.fe_logical >= tmp_pa_end || 4414 ac->ac_o_ex.fe_logical < tmp_pa_start)); 4415 spin_unlock(&tmp_pa->pa_lock); 4416 } 4417 4418 /* 4419 * Step 2: check if the found PA is left or right neighbor and 4420 * get the other neighbor 4421 */ 4422 if (tmp_pa) { 4423 if (tmp_pa->pa_lstart < ac->ac_o_ex.fe_logical) { 4424 struct rb_node *tmp; 4425 4426 left_pa = tmp_pa; 4427 tmp = rb_next(&left_pa->pa_node.inode_node); 4428 if (tmp) { 4429 right_pa = rb_entry(tmp, 4430 struct ext4_prealloc_space, 4431 pa_node.inode_node); 4432 } 4433 } else { 4434 struct rb_node *tmp; 4435 4436 right_pa = tmp_pa; 4437 tmp = rb_prev(&right_pa->pa_node.inode_node); 4438 if (tmp) { 4439 left_pa = rb_entry(tmp, 4440 struct ext4_prealloc_space, 4441 pa_node.inode_node); 4442 } 4443 } 4444 } 4445 4446 /* Step 3: get the non deleted neighbors */ 4447 if (left_pa) { 4448 for (iter = &left_pa->pa_node.inode_node;; 4449 iter = rb_prev(iter)) { 4450 if (!iter) { 4451 left_pa = NULL; 4452 break; 4453 } 4454 4455 tmp_pa = rb_entry(iter, struct ext4_prealloc_space, 4456 pa_node.inode_node); 4457 left_pa = tmp_pa; 4458 spin_lock(&tmp_pa->pa_lock); 4459 if (tmp_pa->pa_deleted == 0) { 4460 spin_unlock(&tmp_pa->pa_lock); 4461 break; 4462 } 4463 spin_unlock(&tmp_pa->pa_lock); 4464 } 4465 } 4466 4467 if (right_pa) { 4468 for (iter = &right_pa->pa_node.inode_node;; 4469 iter = rb_next(iter)) { 4470 if (!iter) { 4471 right_pa = NULL; 4472 break; 4473 } 4474 4475 tmp_pa = rb_entry(iter, struct ext4_prealloc_space, 4476 pa_node.inode_node); 4477 right_pa = tmp_pa; 4478 spin_lock(&tmp_pa->pa_lock); 4479 if (tmp_pa->pa_deleted == 0) { 4480 spin_unlock(&tmp_pa->pa_lock); 4481 break; 4482 } 4483 spin_unlock(&tmp_pa->pa_lock); 4484 } 4485 } 4486 4487 if (left_pa) { 4488 left_pa_end = pa_logical_end(sbi, left_pa); 4489 BUG_ON(left_pa_end > ac->ac_o_ex.fe_logical); 4490 } 4491 4492 if (right_pa) { 4493 right_pa_start = right_pa->pa_lstart; 4494 BUG_ON(right_pa_start <= ac->ac_o_ex.fe_logical); 4495 } 4496 4497 /* Step 4: trim our normalized range to not overlap with the neighbors */ 4498 if (left_pa) { 4499 if (left_pa_end > new_start) 4500 new_start = left_pa_end; 4501 } 4502 4503 if (right_pa) { 4504 if (right_pa_start < new_end) 4505 new_end = right_pa_start; 4506 } 4507 read_unlock(&ei->i_prealloc_lock); 4508 4509 /* XXX: extra loop to check we really don't overlap preallocations */ 4510 ext4_mb_pa_assert_overlap(ac, new_start, new_end); 4511 4512 *start = new_start; 4513 *end = new_end; 4514} 4515 4516/* 4517 * Normalization means making request better in terms of 4518 * size and alignment 4519 */ 4520static noinline_for_stack void 4521ext4_mb_normalize_request(struct ext4_allocation_context *ac, 4522 struct ext4_allocation_request *ar) 4523{ 4524 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 4525 struct ext4_super_block *es = sbi->s_es; 4526 int bsbits, max; 4527 loff_t size, start_off, end; 4528 loff_t orig_size __maybe_unused; 4529 ext4_lblk_t start; 4530 4531 /* do normalize only data requests, metadata requests 4532 do not need preallocation */ 4533 if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) 4534 return; 4535 4536 /* sometime caller may want exact blocks */ 4537 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) 4538 return; 4539 4540 /* caller may indicate that preallocation isn't 4541 * required (it's a tail, for example) */ 4542 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC) 4543 return; 4544 4545 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) { 4546 ext4_mb_normalize_group_request(ac); 4547 return ; 4548 } 4549 4550 bsbits = ac->ac_sb->s_blocksize_bits; 4551 4552 /* first, let's learn actual file size 4553 * given current request is allocated */ 4554 size = extent_logical_end(sbi, &ac->ac_o_ex); 4555 size = size << bsbits; 4556 if (size < i_size_read(ac->ac_inode)) 4557 size = i_size_read(ac->ac_inode); 4558 orig_size = size; 4559 4560 /* max size of free chunks */ 4561 max = 2 << bsbits; 4562 4563#define NRL_CHECK_SIZE(req, size, max, chunk_size) \ 4564 (req <= (size) || max <= (chunk_size)) 4565 4566 /* first, try to predict filesize */ 4567 /* XXX: should this table be tunable? */ 4568 start_off = 0; 4569 if (size <= 16 * 1024) { 4570 size = 16 * 1024; 4571 } else if (size <= 32 * 1024) { 4572 size = 32 * 1024; 4573 } else if (size <= 64 * 1024) { 4574 size = 64 * 1024; 4575 } else if (size <= 128 * 1024) { 4576 size = 128 * 1024; 4577 } else if (size <= 256 * 1024) { 4578 size = 256 * 1024; 4579 } else if (size <= 512 * 1024) { 4580 size = 512 * 1024; 4581 } else if (size <= 1024 * 1024) { 4582 size = 1024 * 1024; 4583 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) { 4584 start_off = ((loff_t)ac->ac_o_ex.fe_logical >> 4585 (21 - bsbits)) << 21; 4586 size = 2 * 1024 * 1024; 4587 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) { 4588 start_off = ((loff_t)ac->ac_o_ex.fe_logical >> 4589 (22 - bsbits)) << 22; 4590 size = 4 * 1024 * 1024; 4591 } else if (NRL_CHECK_SIZE(EXT4_C2B(sbi, ac->ac_o_ex.fe_len), 4592 (8<<20)>>bsbits, max, 8 * 1024)) { 4593 start_off = ((loff_t)ac->ac_o_ex.fe_logical >> 4594 (23 - bsbits)) << 23; 4595 size = 8 * 1024 * 1024; 4596 } else { 4597 start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits; 4598 size = (loff_t) EXT4_C2B(sbi, 4599 ac->ac_o_ex.fe_len) << bsbits; 4600 } 4601 size = size >> bsbits; 4602 start = start_off >> bsbits; 4603 4604 /* 4605 * For tiny groups (smaller than 8MB) the chosen allocation 4606 * alignment may be larger than group size. Make sure the 4607 * alignment does not move allocation to a different group which 4608 * makes mballoc fail assertions later. 4609 */ 4610 start = max(start, rounddown(ac->ac_o_ex.fe_logical, 4611 (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb))); 4612 4613 /* avoid unnecessary preallocation that may trigger assertions */ 4614 if (start + size > EXT_MAX_BLOCKS) 4615 size = EXT_MAX_BLOCKS - start; 4616 4617 /* don't cover already allocated blocks in selected range */ 4618 if (ar->pleft && start <= ar->lleft) { 4619 size -= ar->lleft + 1 - start; 4620 start = ar->lleft + 1; 4621 } 4622 if (ar->pright && start + size - 1 >= ar->lright) 4623 size -= start + size - ar->lright; 4624 4625 /* 4626 * Trim allocation request for filesystems with artificially small 4627 * groups. 4628 */ 4629 if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) 4630 size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb); 4631 4632 end = start + size; 4633 4634 ext4_mb_pa_adjust_overlap(ac, &start, &end); 4635 4636 size = end - start; 4637 4638 /* 4639 * In this function "start" and "size" are normalized for better 4640 * alignment and length such that we could preallocate more blocks. 4641 * This normalization is done such that original request of 4642 * ac->ac_o_ex.fe_logical & fe_len should always lie within "start" and 4643 * "size" boundaries. 4644 * (Note fe_len can be relaxed since FS block allocation API does not 4645 * provide gurantee on number of contiguous blocks allocation since that 4646 * depends upon free space left, etc). 4647 * In case of inode pa, later we use the allocated blocks 4648 * [pa_pstart + fe_logical - pa_lstart, fe_len/size] from the preallocated 4649 * range of goal/best blocks [start, size] to put it at the 4650 * ac_o_ex.fe_logical extent of this inode. 4651 * (See ext4_mb_use_inode_pa() for more details) 4652 */ 4653 if (start + size <= ac->ac_o_ex.fe_logical || 4654 start > ac->ac_o_ex.fe_logical) { 4655 ext4_msg(ac->ac_sb, KERN_ERR, 4656 "start %lu, size %lu, fe_logical %lu", 4657 (unsigned long) start, (unsigned long) size, 4658 (unsigned long) ac->ac_o_ex.fe_logical); 4659 BUG(); 4660 } 4661 BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); 4662 4663 /* now prepare goal request */ 4664 4665 /* XXX: is it better to align blocks WRT to logical 4666 * placement or satisfy big request as is */ 4667 ac->ac_g_ex.fe_logical = start; 4668 ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size); 4669 ac->ac_orig_goal_len = ac->ac_g_ex.fe_len; 4670 4671 /* define goal start in order to merge */ 4672 if (ar->pright && (ar->lright == (start + size)) && 4673 ar->pright >= size && 4674 ar->pright - size >= le32_to_cpu(es->s_first_data_block)) { 4675 /* merge to the right */ 4676 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size, 4677 &ac->ac_g_ex.fe_group, 4678 &ac->ac_g_ex.fe_start); 4679 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; 4680 } 4681 if (ar->pleft && (ar->lleft + 1 == start) && 4682 ar->pleft + 1 < ext4_blocks_count(es)) { 4683 /* merge to the left */ 4684 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1, 4685 &ac->ac_g_ex.fe_group, 4686 &ac->ac_g_ex.fe_start); 4687 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; 4688 } 4689 4690 mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size, 4691 orig_size, start); 4692} 4693 4694static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) 4695{ 4696 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 4697 4698 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) { 4699 atomic_inc(&sbi->s_bal_reqs); 4700 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); 4701 if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len) 4702 atomic_inc(&sbi->s_bal_success); 4703 4704 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); 4705 for (int i=0; i<EXT4_MB_NUM_CRS; i++) { 4706 atomic_add(ac->ac_cX_found[i], &sbi->s_bal_cX_ex_scanned[i]); 4707 } 4708 4709 atomic_add(ac->ac_groups_scanned, &sbi->s_bal_groups_scanned); 4710 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && 4711 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) 4712 atomic_inc(&sbi->s_bal_goals); 4713 /* did we allocate as much as normalizer originally wanted? */ 4714 if (ac->ac_f_ex.fe_len == ac->ac_orig_goal_len) 4715 atomic_inc(&sbi->s_bal_len_goals); 4716 4717 if (ac->ac_found > sbi->s_mb_max_to_scan) 4718 atomic_inc(&sbi->s_bal_breaks); 4719 } 4720 4721 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) 4722 trace_ext4_mballoc_alloc(ac); 4723 else 4724 trace_ext4_mballoc_prealloc(ac); 4725} 4726 4727/* 4728 * Called on failure; free up any blocks from the inode PA for this 4729 * context. We don't need this for MB_GROUP_PA because we only change 4730 * pa_free in ext4_mb_release_context(), but on failure, we've already 4731 * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed. 4732 */ 4733static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac) 4734{ 4735 struct ext4_prealloc_space *pa = ac->ac_pa; 4736 struct ext4_buddy e4b; 4737 int err; 4738 4739 if (pa == NULL) { 4740 if (ac->ac_f_ex.fe_len == 0) 4741 return; 4742 err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b); 4743 if (WARN_RATELIMIT(err, 4744 "ext4: mb_load_buddy failed (%d)", err)) 4745 /* 4746 * This should never happen since we pin the 4747 * folios in the ext4_allocation_context so 4748 * ext4_mb_load_buddy() should never fail. 4749 */ 4750 return; 4751 ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group); 4752 mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start, 4753 ac->ac_f_ex.fe_len); 4754 ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group); 4755 ext4_mb_unload_buddy(&e4b); 4756 return; 4757 } 4758 if (pa->pa_type == MB_INODE_PA) { 4759 spin_lock(&pa->pa_lock); 4760 pa->pa_free += ac->ac_b_ex.fe_len; 4761 spin_unlock(&pa->pa_lock); 4762 } 4763} 4764 4765/* 4766 * use blocks preallocated to inode 4767 */ 4768static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac, 4769 struct ext4_prealloc_space *pa) 4770{ 4771 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 4772 ext4_fsblk_t start; 4773 ext4_fsblk_t end; 4774 int len; 4775 4776 /* found preallocated blocks, use them */ 4777 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart); 4778 end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len), 4779 start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len)); 4780 len = EXT4_NUM_B2C(sbi, end - start); 4781 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group, 4782 &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 BUG_ON(start < pa->pa_pstart); 4788 BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len)); 4789 BUG_ON(pa->pa_free < len); 4790 BUG_ON(ac->ac_b_ex.fe_len <= 0); 4791 pa->pa_free -= len; 4792 4793 mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa); 4794} 4795 4796/* 4797 * use blocks preallocated to locality group 4798 */ 4799static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, 4800 struct ext4_prealloc_space *pa) 4801{ 4802 unsigned int len = ac->ac_o_ex.fe_len; 4803 4804 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart, 4805 &ac->ac_b_ex.fe_group, 4806 &ac->ac_b_ex.fe_start); 4807 ac->ac_b_ex.fe_len = len; 4808 ac->ac_status = AC_STATUS_FOUND; 4809 ac->ac_pa = pa; 4810 4811 /* we don't correct pa_pstart or pa_len here to avoid 4812 * possible race when the group is being loaded concurrently 4813 * instead we correct pa later, after blocks are marked 4814 * in on-disk bitmap -- see ext4_mb_release_context() 4815 * Other CPUs are prevented from allocating from this pa by lg_mutex 4816 */ 4817 mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n", 4818 pa->pa_lstart, len, pa); 4819} 4820 4821/* 4822 * Return the prealloc space that have minimal distance 4823 * from the goal block. @cpa is the prealloc 4824 * space that is having currently known minimal distance 4825 * from the goal block. 4826 */ 4827static struct ext4_prealloc_space * 4828ext4_mb_check_group_pa(ext4_fsblk_t goal_block, 4829 struct ext4_prealloc_space *pa, 4830 struct ext4_prealloc_space *cpa) 4831{ 4832 ext4_fsblk_t cur_distance, new_distance; 4833 4834 if (cpa == NULL) { 4835 atomic_inc(&pa->pa_count); 4836 return pa; 4837 } 4838 cur_distance = abs(goal_block - cpa->pa_pstart); 4839 new_distance = abs(goal_block - pa->pa_pstart); 4840 4841 if (cur_distance <= new_distance) 4842 return cpa; 4843 4844 /* drop the previous reference */ 4845 atomic_dec(&cpa->pa_count); 4846 atomic_inc(&pa->pa_count); 4847 return pa; 4848} 4849 4850/* 4851 * check if found pa meets EXT4_MB_HINT_GOAL_ONLY 4852 */ 4853static bool 4854ext4_mb_pa_goal_check(struct ext4_allocation_context *ac, 4855 struct ext4_prealloc_space *pa) 4856{ 4857 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 4858 ext4_fsblk_t start; 4859 4860 if (likely(!(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))) 4861 return true; 4862 4863 /* 4864 * If EXT4_MB_HINT_GOAL_ONLY is set, ac_g_ex will not be adjusted 4865 * in ext4_mb_normalize_request and will keep same with ac_o_ex 4866 * from ext4_mb_initialize_context. Choose ac_g_ex here to keep 4867 * consistent with ext4_mb_find_by_goal. 4868 */ 4869 start = pa->pa_pstart + 4870 (ac->ac_g_ex.fe_logical - pa->pa_lstart); 4871 if (ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex) != start) 4872 return false; 4873 4874 if (ac->ac_g_ex.fe_len > pa->pa_len - 4875 EXT4_B2C(sbi, ac->ac_g_ex.fe_logical - pa->pa_lstart)) 4876 return false; 4877 4878 return true; 4879} 4880 4881/* 4882 * search goal blocks in preallocated space 4883 */ 4884static noinline_for_stack bool 4885ext4_mb_use_preallocated(struct ext4_allocation_context *ac) 4886{ 4887 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 4888 int order, i; 4889 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); 4890 struct ext4_locality_group *lg; 4891 struct ext4_prealloc_space *tmp_pa = NULL, *cpa = NULL; 4892 struct rb_node *iter; 4893 ext4_fsblk_t goal_block; 4894 4895 /* only data can be preallocated */ 4896 if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) 4897 return false; 4898 4899 /* 4900 * first, try per-file preallocation by searching the inode pa rbtree. 4901 * 4902 * Here, we can't do a direct traversal of the tree because 4903 * ext4_mb_discard_group_preallocation() can paralelly mark the pa 4904 * deleted and that can cause direct traversal to skip some entries. 4905 */ 4906 read_lock(&ei->i_prealloc_lock); 4907 4908 if (RB_EMPTY_ROOT(&ei->i_prealloc_node)) { 4909 goto try_group_pa; 4910 } 4911 4912 /* 4913 * Step 1: Find a pa with logical start immediately adjacent to the 4914 * original logical start. This could be on the left or right. 4915 * 4916 * (tmp_pa->pa_lstart never changes so we can skip locking for it). 4917 */ 4918 for (iter = ei->i_prealloc_node.rb_node; iter; 4919 iter = ext4_mb_pa_rb_next_iter(ac->ac_o_ex.fe_logical, 4920 tmp_pa->pa_lstart, iter)) { 4921 tmp_pa = rb_entry(iter, struct ext4_prealloc_space, 4922 pa_node.inode_node); 4923 } 4924 4925 /* 4926 * Step 2: The adjacent pa might be to the right of logical start, find 4927 * the left adjacent pa. After this step we'd have a valid tmp_pa whose 4928 * logical start is towards the left of original request's logical start 4929 */ 4930 if (tmp_pa->pa_lstart > ac->ac_o_ex.fe_logical) { 4931 struct rb_node *tmp; 4932 tmp = rb_prev(&tmp_pa->pa_node.inode_node); 4933 4934 if (tmp) { 4935 tmp_pa = rb_entry(tmp, struct ext4_prealloc_space, 4936 pa_node.inode_node); 4937 } else { 4938 /* 4939 * If there is no adjacent pa to the left then finding 4940 * an overlapping pa is not possible hence stop searching 4941 * inode pa tree 4942 */ 4943 goto try_group_pa; 4944 } 4945 } 4946 4947 BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical)); 4948 4949 /* 4950 * Step 3: If the left adjacent pa is deleted, keep moving left to find 4951 * the first non deleted adjacent pa. After this step we should have a 4952 * valid tmp_pa which is guaranteed to be non deleted. 4953 */ 4954 for (iter = &tmp_pa->pa_node.inode_node;; iter = rb_prev(iter)) { 4955 if (!iter) { 4956 /* 4957 * no non deleted left adjacent pa, so stop searching 4958 * inode pa tree 4959 */ 4960 goto try_group_pa; 4961 } 4962 tmp_pa = rb_entry(iter, struct ext4_prealloc_space, 4963 pa_node.inode_node); 4964 spin_lock(&tmp_pa->pa_lock); 4965 if (tmp_pa->pa_deleted == 0) { 4966 /* 4967 * We will keep holding the pa_lock from 4968 * this point on because we don't want group discard 4969 * to delete this pa underneath us. Since group 4970 * discard is anyways an ENOSPC operation it 4971 * should be okay for it to wait a few more cycles. 4972 */ 4973 break; 4974 } else { 4975 spin_unlock(&tmp_pa->pa_lock); 4976 } 4977 } 4978 4979 BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical)); 4980 BUG_ON(tmp_pa->pa_deleted == 1); 4981 4982 /* 4983 * Step 4: We now have the non deleted left adjacent pa. Only this 4984 * pa can possibly satisfy the request hence check if it overlaps 4985 * original logical start and stop searching if it doesn't. 4986 */ 4987 if (ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, tmp_pa)) { 4988 spin_unlock(&tmp_pa->pa_lock); 4989 goto try_group_pa; 4990 } 4991 4992 /* non-extent files can't have physical blocks past 2^32 */ 4993 if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) && 4994 (tmp_pa->pa_pstart + EXT4_C2B(sbi, tmp_pa->pa_len) > 4995 EXT4_MAX_BLOCK_FILE_PHYS)) { 4996 /* 4997 * Since PAs don't overlap, we won't find any other PA to 4998 * satisfy this. 4999 */ 5000 spin_unlock(&tmp_pa->pa_lock); 5001 goto try_group_pa; 5002 } 5003 5004 if (tmp_pa->pa_free && likely(ext4_mb_pa_goal_check(ac, tmp_pa))) { 5005 atomic_inc(&tmp_pa->pa_count); 5006 ext4_mb_use_inode_pa(ac, tmp_pa); 5007 spin_unlock(&tmp_pa->pa_lock); 5008 read_unlock(&ei->i_prealloc_lock); 5009 return true; 5010 } else { 5011 /* 5012 * We found a valid overlapping pa but couldn't use it because 5013 * it had no free blocks. This should ideally never happen 5014 * because: 5015 * 5016 * 1. When a new inode pa is added to rbtree it must have 5017 * pa_free > 0 since otherwise we won't actually need 5018 * preallocation. 5019 * 5020 * 2. An inode pa that is in the rbtree can only have it's 5021 * pa_free become zero when another thread calls: 5022 * ext4_mb_new_blocks 5023 * ext4_mb_use_preallocated 5024 * ext4_mb_use_inode_pa 5025 * 5026 * 3. Further, after the above calls make pa_free == 0, we will 5027 * immediately remove it from the rbtree in: 5028 * ext4_mb_new_blocks 5029 * ext4_mb_release_context 5030 * ext4_mb_put_pa 5031 * 5032 * 4. Since the pa_free becoming 0 and pa_free getting removed 5033 * from tree both happen in ext4_mb_new_blocks, which is always 5034 * called with i_data_sem held for data allocations, we can be 5035 * sure that another process will never see a pa in rbtree with 5036 * pa_free == 0. 5037 */ 5038 WARN_ON_ONCE(tmp_pa->pa_free == 0); 5039 } 5040 spin_unlock(&tmp_pa->pa_lock); 5041try_group_pa: 5042 read_unlock(&ei->i_prealloc_lock); 5043 5044 /* can we use group allocation? */ 5045 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)) 5046 return false; 5047 5048 /* inode may have no locality group for some reason */ 5049 lg = ac->ac_lg; 5050 if (lg == NULL) 5051 return false; 5052 order = fls(ac->ac_o_ex.fe_len) - 1; 5053 if (order > PREALLOC_TB_SIZE - 1) 5054 /* The max size of hash table is PREALLOC_TB_SIZE */ 5055 order = PREALLOC_TB_SIZE - 1; 5056 5057 goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex); 5058 /* 5059 * search for the prealloc space that is having 5060 * minimal distance from the goal block. 5061 */ 5062 for (i = order; i < PREALLOC_TB_SIZE; i++) { 5063 rcu_read_lock(); 5064 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[i], 5065 pa_node.lg_list) { 5066 spin_lock(&tmp_pa->pa_lock); 5067 if (tmp_pa->pa_deleted == 0 && 5068 tmp_pa->pa_free >= ac->ac_o_ex.fe_len) { 5069 5070 cpa = ext4_mb_check_group_pa(goal_block, 5071 tmp_pa, cpa); 5072 } 5073 spin_unlock(&tmp_pa->pa_lock); 5074 } 5075 rcu_read_unlock(); 5076 } 5077 if (cpa) { 5078 ext4_mb_use_group_pa(ac, cpa); 5079 return true; 5080 } 5081 return false; 5082} 5083 5084/* 5085 * the function goes through all preallocation in this group and marks them 5086 * used in in-core bitmap. buddy must be generated from this bitmap 5087 * Need to be called with ext4 group lock held 5088 */ 5089static noinline_for_stack 5090void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, 5091 ext4_group_t group) 5092{ 5093 struct ext4_group_info *grp = ext4_get_group_info(sb, group); 5094 struct ext4_prealloc_space *pa; 5095 struct list_head *cur; 5096 ext4_group_t groupnr; 5097 ext4_grpblk_t start; 5098 int preallocated = 0; 5099 int len; 5100 5101 if (!grp) 5102 return; 5103 5104 /* all form of preallocation discards first load group, 5105 * so the only competing code is preallocation use. 5106 * we don't need any locking here 5107 * notice we do NOT ignore preallocations with pa_deleted 5108 * otherwise we could leave used blocks available for 5109 * allocation in buddy when concurrent ext4_mb_put_pa() 5110 * is dropping preallocation 5111 */ 5112 list_for_each(cur, &grp->bb_prealloc_list) { 5113 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); 5114 spin_lock(&pa->pa_lock); 5115 ext4_get_group_no_and_offset(sb, pa->pa_pstart, 5116 &groupnr, &start); 5117 len = pa->pa_len; 5118 spin_unlock(&pa->pa_lock); 5119 if (unlikely(len == 0)) 5120 continue; 5121 BUG_ON(groupnr != group); 5122 mb_set_bits(bitmap, start, len); 5123 preallocated += len; 5124 } 5125 mb_debug(sb, "preallocated %d for group %u\n", preallocated, group); 5126} 5127 5128static void ext4_mb_mark_pa_deleted(struct super_block *sb, 5129 struct ext4_prealloc_space *pa) 5130{ 5131 struct ext4_inode_info *ei; 5132 5133 if (pa->pa_deleted) { 5134 ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n", 5135 pa->pa_type, pa->pa_pstart, pa->pa_lstart, 5136 pa->pa_len); 5137 return; 5138 } 5139 5140 pa->pa_deleted = 1; 5141 5142 if (pa->pa_type == MB_INODE_PA) { 5143 ei = EXT4_I(pa->pa_inode); 5144 atomic_dec(&ei->i_prealloc_active); 5145 } 5146} 5147 5148static inline void ext4_mb_pa_free(struct ext4_prealloc_space *pa) 5149{ 5150 BUG_ON(!pa); 5151 BUG_ON(atomic_read(&pa->pa_count)); 5152 BUG_ON(pa->pa_deleted == 0); 5153 kmem_cache_free(ext4_pspace_cachep, pa); 5154} 5155 5156static void ext4_mb_pa_callback(struct rcu_head *head) 5157{ 5158 struct ext4_prealloc_space *pa; 5159 5160 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu); 5161 ext4_mb_pa_free(pa); 5162} 5163 5164/* 5165 * drops a reference to preallocated space descriptor 5166 * if this was the last reference and the space is consumed 5167 */ 5168static void ext4_mb_put_pa(struct ext4_allocation_context *ac, 5169 struct super_block *sb, struct ext4_prealloc_space *pa) 5170{ 5171 ext4_group_t grp; 5172 ext4_fsblk_t grp_blk; 5173 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); 5174 5175 /* in this short window concurrent discard can set pa_deleted */ 5176 spin_lock(&pa->pa_lock); 5177 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) { 5178 spin_unlock(&pa->pa_lock); 5179 return; 5180 } 5181 5182 if (pa->pa_deleted == 1) { 5183 spin_unlock(&pa->pa_lock); 5184 return; 5185 } 5186 5187 ext4_mb_mark_pa_deleted(sb, pa); 5188 spin_unlock(&pa->pa_lock); 5189 5190 grp_blk = pa->pa_pstart; 5191 /* 5192 * If doing group-based preallocation, pa_pstart may be in the 5193 * next group when pa is used up 5194 */ 5195 if (pa->pa_type == MB_GROUP_PA) 5196 grp_blk--; 5197 5198 grp = ext4_get_group_number(sb, grp_blk); 5199 5200 /* 5201 * possible race: 5202 * 5203 * P1 (buddy init) P2 (regular allocation) 5204 * find block B in PA 5205 * copy on-disk bitmap to buddy 5206 * mark B in on-disk bitmap 5207 * drop PA from group 5208 * mark all PAs in buddy 5209 * 5210 * thus, P1 initializes buddy with B available. to prevent this 5211 * we make "copy" and "mark all PAs" atomic and serialize "drop PA" 5212 * against that pair 5213 */ 5214 ext4_lock_group(sb, grp); 5215 list_del(&pa->pa_group_list); 5216 ext4_unlock_group(sb, grp); 5217 5218 if (pa->pa_type == MB_INODE_PA) { 5219 write_lock(pa->pa_node_lock.inode_lock); 5220 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node); 5221 write_unlock(pa->pa_node_lock.inode_lock); 5222 ext4_mb_pa_free(pa); 5223 } else { 5224 spin_lock(pa->pa_node_lock.lg_lock); 5225 list_del_rcu(&pa->pa_node.lg_list); 5226 spin_unlock(pa->pa_node_lock.lg_lock); 5227 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); 5228 } 5229} 5230 5231static void ext4_mb_pa_rb_insert(struct rb_root *root, struct rb_node *new) 5232{ 5233 struct rb_node **iter = &root->rb_node, *parent = NULL; 5234 struct ext4_prealloc_space *iter_pa, *new_pa; 5235 ext4_lblk_t iter_start, new_start; 5236 5237 while (*iter) { 5238 iter_pa = rb_entry(*iter, struct ext4_prealloc_space, 5239 pa_node.inode_node); 5240 new_pa = rb_entry(new, struct ext4_prealloc_space, 5241 pa_node.inode_node); 5242 iter_start = iter_pa->pa_lstart; 5243 new_start = new_pa->pa_lstart; 5244 5245 parent = *iter; 5246 if (new_start < iter_start) 5247 iter = &((*iter)->rb_left); 5248 else 5249 iter = &((*iter)->rb_right); 5250 } 5251 5252 rb_link_node(new, parent, iter); 5253 rb_insert_color(new, root); 5254} 5255 5256/* 5257 * creates new preallocated space for given inode 5258 */ 5259static noinline_for_stack void 5260ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) 5261{ 5262 struct super_block *sb = ac->ac_sb; 5263 struct ext4_sb_info *sbi = EXT4_SB(sb); 5264 struct ext4_prealloc_space *pa; 5265 struct ext4_group_info *grp; 5266 struct ext4_inode_info *ei; 5267 5268 /* preallocate only when found space is larger then requested */ 5269 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); 5270 BUG_ON(ac->ac_status != AC_STATUS_FOUND); 5271 BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); 5272 BUG_ON(ac->ac_pa == NULL); 5273 5274 pa = ac->ac_pa; 5275 5276 if (ac->ac_b_ex.fe_len < ac->ac_orig_goal_len) { 5277 struct ext4_free_extent ex = { 5278 .fe_logical = ac->ac_g_ex.fe_logical, 5279 .fe_len = ac->ac_orig_goal_len, 5280 }; 5281 loff_t orig_goal_end = extent_logical_end(sbi, &ex); 5282 loff_t o_ex_end = extent_logical_end(sbi, &ac->ac_o_ex); 5283 5284 /* 5285 * We can't allocate as much as normalizer wants, so we try 5286 * to get proper lstart to cover the original request, except 5287 * when the goal doesn't cover the original request as below: 5288 * 5289 * orig_ex:2045/2055(10), isize:8417280 -> normalized:0/2048 5290 * best_ex:0/200(200) -> adjusted: 1848/2048(200) 5291 */ 5292 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); 5293 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); 5294 5295 /* 5296 * Use the below logic for adjusting best extent as it keeps 5297 * fragmentation in check while ensuring logical range of best 5298 * extent doesn't overflow out of goal extent: 5299 * 5300 * 1. Check if best ex can be kept at end of goal (before 5301 * cr_best_avail trimmed it) and still cover original start 5302 * 2. Else, check if best ex can be kept at start of goal and 5303 * still cover original end 5304 * 3. Else, keep the best ex at start of original request. 5305 */ 5306 ex.fe_len = ac->ac_b_ex.fe_len; 5307 5308 ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len); 5309 if (ac->ac_o_ex.fe_logical >= ex.fe_logical) 5310 goto adjust_bex; 5311 5312 ex.fe_logical = ac->ac_g_ex.fe_logical; 5313 if (o_ex_end <= extent_logical_end(sbi, &ex)) 5314 goto adjust_bex; 5315 5316 ex.fe_logical = ac->ac_o_ex.fe_logical; 5317adjust_bex: 5318 ac->ac_b_ex.fe_logical = ex.fe_logical; 5319 5320 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); 5321 BUG_ON(extent_logical_end(sbi, &ex) > orig_goal_end); 5322 } 5323 5324 pa->pa_lstart = ac->ac_b_ex.fe_logical; 5325 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); 5326 pa->pa_len = ac->ac_b_ex.fe_len; 5327 pa->pa_free = pa->pa_len; 5328 spin_lock_init(&pa->pa_lock); 5329 INIT_LIST_HEAD(&pa->pa_group_list); 5330 pa->pa_deleted = 0; 5331 pa->pa_type = MB_INODE_PA; 5332 5333 mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart, 5334 pa->pa_len, pa->pa_lstart); 5335 trace_ext4_mb_new_inode_pa(ac, pa); 5336 5337 atomic_add(pa->pa_free, &sbi->s_mb_preallocated); 5338 ext4_mb_use_inode_pa(ac, pa); 5339 5340 ei = EXT4_I(ac->ac_inode); 5341 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); 5342 if (!grp) 5343 return; 5344 5345 pa->pa_node_lock.inode_lock = &ei->i_prealloc_lock; 5346 pa->pa_inode = ac->ac_inode; 5347 5348 list_add(&pa->pa_group_list, &grp->bb_prealloc_list); 5349 5350 write_lock(pa->pa_node_lock.inode_lock); 5351 ext4_mb_pa_rb_insert(&ei->i_prealloc_node, &pa->pa_node.inode_node); 5352 write_unlock(pa->pa_node_lock.inode_lock); 5353 atomic_inc(&ei->i_prealloc_active); 5354} 5355 5356/* 5357 * creates new preallocated space for locality group inodes belongs to 5358 */ 5359static noinline_for_stack void 5360ext4_mb_new_group_pa(struct ext4_allocation_context *ac) 5361{ 5362 struct super_block *sb = ac->ac_sb; 5363 struct ext4_locality_group *lg; 5364 struct ext4_prealloc_space *pa; 5365 struct ext4_group_info *grp; 5366 5367 /* preallocate only when found space is larger then requested */ 5368 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); 5369 BUG_ON(ac->ac_status != AC_STATUS_FOUND); 5370 BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); 5371 BUG_ON(ac->ac_pa == NULL); 5372 5373 pa = ac->ac_pa; 5374 5375 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); 5376 pa->pa_lstart = pa->pa_pstart; 5377 pa->pa_len = ac->ac_b_ex.fe_len; 5378 pa->pa_free = pa->pa_len; 5379 spin_lock_init(&pa->pa_lock); 5380 INIT_LIST_HEAD(&pa->pa_node.lg_list); 5381 INIT_LIST_HEAD(&pa->pa_group_list); 5382 pa->pa_deleted = 0; 5383 pa->pa_type = MB_GROUP_PA; 5384 5385 mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart, 5386 pa->pa_len, pa->pa_lstart); 5387 trace_ext4_mb_new_group_pa(ac, pa); 5388 5389 ext4_mb_use_group_pa(ac, pa); 5390 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); 5391 5392 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); 5393 if (!grp) 5394 return; 5395 lg = ac->ac_lg; 5396 BUG_ON(lg == NULL); 5397 5398 pa->pa_node_lock.lg_lock = &lg->lg_prealloc_lock; 5399 pa->pa_inode = NULL; 5400 5401 list_add(&pa->pa_group_list, &grp->bb_prealloc_list); 5402 5403 /* 5404 * We will later add the new pa to the right bucket 5405 * after updating the pa_free in ext4_mb_release_context 5406 */ 5407} 5408 5409static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac) 5410{ 5411 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) 5412 ext4_mb_new_group_pa(ac); 5413 else 5414 ext4_mb_new_inode_pa(ac); 5415} 5416 5417/* 5418 * finds all unused blocks in on-disk bitmap, frees them in 5419 * in-core bitmap and buddy. 5420 * @pa must be unlinked from inode and group lists, so that 5421 * nobody else can find/use it. 5422 * the caller MUST hold group/inode locks. 5423 * TODO: optimize the case when there are no in-core structures yet 5424 */ 5425static noinline_for_stack void 5426ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, 5427 struct ext4_prealloc_space *pa) 5428{ 5429 struct super_block *sb = e4b->bd_sb; 5430 struct ext4_sb_info *sbi = EXT4_SB(sb); 5431 unsigned int end; 5432 unsigned int next; 5433 ext4_group_t group; 5434 ext4_grpblk_t bit; 5435 unsigned long long grp_blk_start; 5436 int free = 0; 5437 5438 BUG_ON(pa->pa_deleted == 0); 5439 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); 5440 grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit); 5441 BUG_ON(group != e4b->bd_group && pa->pa_len != 0); 5442 end = bit + pa->pa_len; 5443 5444 while (bit < end) { 5445 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit); 5446 if (bit >= end) 5447 break; 5448 next = mb_find_next_bit(bitmap_bh->b_data, end, bit); 5449 mb_debug(sb, "free preallocated %u/%u in group %u\n", 5450 (unsigned) ext4_group_first_block_no(sb, group) + bit, 5451 (unsigned) next - bit, (unsigned) group); 5452 free += next - bit; 5453 5454 trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit); 5455 trace_ext4_mb_release_inode_pa(pa, (grp_blk_start + 5456 EXT4_C2B(sbi, bit)), 5457 next - bit); 5458 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); 5459 bit = next + 1; 5460 } 5461 if (free != pa->pa_free) { 5462 ext4_msg(e4b->bd_sb, KERN_CRIT, 5463 "pa %p: logic %lu, phys. %lu, len %d", 5464 pa, (unsigned long) pa->pa_lstart, 5465 (unsigned long) pa->pa_pstart, 5466 pa->pa_len); 5467 ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u", 5468 free, pa->pa_free); 5469 /* 5470 * pa is already deleted so we use the value obtained 5471 * from the bitmap and continue. 5472 */ 5473 } 5474 atomic_add(free, &sbi->s_mb_discarded); 5475} 5476 5477static noinline_for_stack void 5478ext4_mb_release_group_pa(struct ext4_buddy *e4b, 5479 struct ext4_prealloc_space *pa) 5480{ 5481 struct super_block *sb = e4b->bd_sb; 5482 ext4_group_t group; 5483 ext4_grpblk_t bit; 5484 5485 trace_ext4_mb_release_group_pa(sb, pa); 5486 BUG_ON(pa->pa_deleted == 0); 5487 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); 5488 if (unlikely(group != e4b->bd_group && pa->pa_len != 0)) { 5489 ext4_warning(sb, "bad group: expected %u, group %u, pa_start %llu", 5490 e4b->bd_group, group, pa->pa_pstart); 5491 return; 5492 } 5493 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len); 5494 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded); 5495 trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len); 5496} 5497 5498/* 5499 * releases all preallocations in given group 5500 * 5501 * first, we need to decide discard policy: 5502 * - when do we discard 5503 * 1) ENOSPC 5504 * - how many do we discard 5505 * 1) how many requested 5506 */ 5507static noinline_for_stack int 5508ext4_mb_discard_group_preallocations(struct super_block *sb, 5509 ext4_group_t group, int *busy) 5510{ 5511 struct ext4_group_info *grp = ext4_get_group_info(sb, group); 5512 struct buffer_head *bitmap_bh = NULL; 5513 struct ext4_prealloc_space *pa, *tmp; 5514 LIST_HEAD(list); 5515 struct ext4_buddy e4b; 5516 struct ext4_inode_info *ei; 5517 int err; 5518 int free = 0; 5519 5520 if (!grp) 5521 return 0; 5522 mb_debug(sb, "discard preallocation for group %u\n", group); 5523 if (list_empty(&grp->bb_prealloc_list)) 5524 goto out_dbg; 5525 5526 bitmap_bh = ext4_read_block_bitmap(sb, group); 5527 if (IS_ERR(bitmap_bh)) { 5528 err = PTR_ERR(bitmap_bh); 5529 ext4_error_err(sb, -err, 5530 "Error %d reading block bitmap for %u", 5531 err, group); 5532 goto out_dbg; 5533 } 5534 5535 err = ext4_mb_load_buddy(sb, group, &e4b); 5536 if (err) { 5537 ext4_warning(sb, "Error %d loading buddy information for %u", 5538 err, group); 5539 put_bh(bitmap_bh); 5540 goto out_dbg; 5541 } 5542 5543 ext4_lock_group(sb, group); 5544 list_for_each_entry_safe(pa, tmp, 5545 &grp->bb_prealloc_list, pa_group_list) { 5546 spin_lock(&pa->pa_lock); 5547 if (atomic_read(&pa->pa_count)) { 5548 spin_unlock(&pa->pa_lock); 5549 *busy = 1; 5550 continue; 5551 } 5552 if (pa->pa_deleted) { 5553 spin_unlock(&pa->pa_lock); 5554 continue; 5555 } 5556 5557 /* seems this one can be freed ... */ 5558 ext4_mb_mark_pa_deleted(sb, pa); 5559 5560 if (!free) 5561 this_cpu_inc(discard_pa_seq); 5562 5563 /* we can trust pa_free ... */ 5564 free += pa->pa_free; 5565 5566 spin_unlock(&pa->pa_lock); 5567 5568 list_del(&pa->pa_group_list); 5569 list_add(&pa->u.pa_tmp_list, &list); 5570 } 5571 5572 /* now free all selected PAs */ 5573 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { 5574 5575 /* remove from object (inode or locality group) */ 5576 if (pa->pa_type == MB_GROUP_PA) { 5577 spin_lock(pa->pa_node_lock.lg_lock); 5578 list_del_rcu(&pa->pa_node.lg_list); 5579 spin_unlock(pa->pa_node_lock.lg_lock); 5580 } else { 5581 write_lock(pa->pa_node_lock.inode_lock); 5582 ei = EXT4_I(pa->pa_inode); 5583 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node); 5584 write_unlock(pa->pa_node_lock.inode_lock); 5585 } 5586 5587 list_del(&pa->u.pa_tmp_list); 5588 5589 if (pa->pa_type == MB_GROUP_PA) { 5590 ext4_mb_release_group_pa(&e4b, pa); 5591 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); 5592 } else { 5593 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); 5594 ext4_mb_pa_free(pa); 5595 } 5596 } 5597 5598 ext4_unlock_group(sb, group); 5599 ext4_mb_unload_buddy(&e4b); 5600 put_bh(bitmap_bh); 5601out_dbg: 5602 mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n", 5603 free, group, grp->bb_free); 5604 return free; 5605} 5606 5607/* 5608 * releases all non-used preallocated blocks for given inode 5609 * 5610 * It's important to discard preallocations under i_data_sem 5611 * We don't want another block to be served from the prealloc 5612 * space when we are discarding the inode prealloc space. 5613 * 5614 * FIXME!! Make sure it is valid at all the call sites 5615 */ 5616void ext4_discard_preallocations(struct inode *inode) 5617{ 5618 struct ext4_inode_info *ei = EXT4_I(inode); 5619 struct super_block *sb = inode->i_sb; 5620 struct buffer_head *bitmap_bh = NULL; 5621 struct ext4_prealloc_space *pa, *tmp; 5622 ext4_group_t group = 0; 5623 LIST_HEAD(list); 5624 struct ext4_buddy e4b; 5625 struct rb_node *iter; 5626 int err; 5627 5628 if (!S_ISREG(inode->i_mode)) 5629 return; 5630 5631 if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) 5632 return; 5633 5634 mb_debug(sb, "discard preallocation for inode %lu\n", 5635 inode->i_ino); 5636 trace_ext4_discard_preallocations(inode, 5637 atomic_read(&ei->i_prealloc_active)); 5638 5639repeat: 5640 /* first, collect all pa's in the inode */ 5641 write_lock(&ei->i_prealloc_lock); 5642 for (iter = rb_first(&ei->i_prealloc_node); iter; 5643 iter = rb_next(iter)) { 5644 pa = rb_entry(iter, struct ext4_prealloc_space, 5645 pa_node.inode_node); 5646 BUG_ON(pa->pa_node_lock.inode_lock != &ei->i_prealloc_lock); 5647 5648 spin_lock(&pa->pa_lock); 5649 if (atomic_read(&pa->pa_count)) { 5650 /* this shouldn't happen often - nobody should 5651 * use preallocation while we're discarding it */ 5652 spin_unlock(&pa->pa_lock); 5653 write_unlock(&ei->i_prealloc_lock); 5654 ext4_msg(sb, KERN_ERR, 5655 "uh-oh! used pa while discarding"); 5656 WARN_ON(1); 5657 schedule_timeout_uninterruptible(HZ); 5658 goto repeat; 5659 5660 } 5661 if (pa->pa_deleted == 0) { 5662 ext4_mb_mark_pa_deleted(sb, pa); 5663 spin_unlock(&pa->pa_lock); 5664 rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node); 5665 list_add(&pa->u.pa_tmp_list, &list); 5666 continue; 5667 } 5668 5669 /* someone is deleting pa right now */ 5670 spin_unlock(&pa->pa_lock); 5671 write_unlock(&ei->i_prealloc_lock); 5672 5673 /* we have to wait here because pa_deleted 5674 * doesn't mean pa is already unlinked from 5675 * the list. as we might be called from 5676 * ->clear_inode() the inode will get freed 5677 * and concurrent thread which is unlinking 5678 * pa from inode's list may access already 5679 * freed memory, bad-bad-bad */ 5680 5681 /* XXX: if this happens too often, we can 5682 * add a flag to force wait only in case 5683 * of ->clear_inode(), but not in case of 5684 * regular truncate */ 5685 schedule_timeout_uninterruptible(HZ); 5686 goto repeat; 5687 } 5688 write_unlock(&ei->i_prealloc_lock); 5689 5690 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { 5691 BUG_ON(pa->pa_type != MB_INODE_PA); 5692 group = ext4_get_group_number(sb, pa->pa_pstart); 5693 5694 err = ext4_mb_load_buddy_gfp(sb, group, &e4b, 5695 GFP_NOFS|__GFP_NOFAIL); 5696 if (err) { 5697 ext4_error_err(sb, -err, "Error %d loading buddy information for %u", 5698 err, group); 5699 continue; 5700 } 5701 5702 bitmap_bh = ext4_read_block_bitmap(sb, group); 5703 if (IS_ERR(bitmap_bh)) { 5704 err = PTR_ERR(bitmap_bh); 5705 ext4_error_err(sb, -err, "Error %d reading block bitmap for %u", 5706 err, group); 5707 ext4_mb_unload_buddy(&e4b); 5708 continue; 5709 } 5710 5711 ext4_lock_group(sb, group); 5712 list_del(&pa->pa_group_list); 5713 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); 5714 ext4_unlock_group(sb, group); 5715 5716 ext4_mb_unload_buddy(&e4b); 5717 put_bh(bitmap_bh); 5718 5719 list_del(&pa->u.pa_tmp_list); 5720 ext4_mb_pa_free(pa); 5721 } 5722} 5723 5724static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac) 5725{ 5726 struct ext4_prealloc_space *pa; 5727 5728 BUG_ON(ext4_pspace_cachep == NULL); 5729 pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS); 5730 if (!pa) 5731 return -ENOMEM; 5732 atomic_set(&pa->pa_count, 1); 5733 ac->ac_pa = pa; 5734 return 0; 5735} 5736 5737static void ext4_mb_pa_put_free(struct ext4_allocation_context *ac) 5738{ 5739 struct ext4_prealloc_space *pa = ac->ac_pa; 5740 5741 BUG_ON(!pa); 5742 ac->ac_pa = NULL; 5743 WARN_ON(!atomic_dec_and_test(&pa->pa_count)); 5744 /* 5745 * current function is only called due to an error or due to 5746 * len of found blocks < len of requested blocks hence the PA has not 5747 * been added to grp->bb_prealloc_list. So we don't need to lock it 5748 */ 5749 pa->pa_deleted = 1; 5750 ext4_mb_pa_free(pa); 5751} 5752 5753#ifdef CONFIG_EXT4_DEBUG 5754static inline void ext4_mb_show_pa(struct super_block *sb) 5755{ 5756 ext4_group_t i, ngroups; 5757 5758 if (ext4_emergency_state(sb)) 5759 return; 5760 5761 ngroups = ext4_get_groups_count(sb); 5762 mb_debug(sb, "groups: "); 5763 for (i = 0; i < ngroups; i++) { 5764 struct ext4_group_info *grp = ext4_get_group_info(sb, i); 5765 struct ext4_prealloc_space *pa; 5766 ext4_grpblk_t start; 5767 struct list_head *cur; 5768 5769 if (!grp) 5770 continue; 5771 ext4_lock_group(sb, i); 5772 list_for_each(cur, &grp->bb_prealloc_list) { 5773 pa = list_entry(cur, struct ext4_prealloc_space, 5774 pa_group_list); 5775 spin_lock(&pa->pa_lock); 5776 ext4_get_group_no_and_offset(sb, pa->pa_pstart, 5777 NULL, &start); 5778 spin_unlock(&pa->pa_lock); 5779 mb_debug(sb, "PA:%u:%d:%d\n", i, start, 5780 pa->pa_len); 5781 } 5782 ext4_unlock_group(sb, i); 5783 mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free, 5784 grp->bb_fragments); 5785 } 5786} 5787 5788static void ext4_mb_show_ac(struct ext4_allocation_context *ac) 5789{ 5790 struct super_block *sb = ac->ac_sb; 5791 5792 if (ext4_emergency_state(sb)) 5793 return; 5794 5795 mb_debug(sb, "Can't allocate:" 5796 " Allocation context details:"); 5797 mb_debug(sb, "status %u flags 0x%x", 5798 ac->ac_status, ac->ac_flags); 5799 mb_debug(sb, "orig %lu/%lu/%lu@%lu, " 5800 "goal %lu/%lu/%lu@%lu, " 5801 "best %lu/%lu/%lu@%lu cr %d", 5802 (unsigned long)ac->ac_o_ex.fe_group, 5803 (unsigned long)ac->ac_o_ex.fe_start, 5804 (unsigned long)ac->ac_o_ex.fe_len, 5805 (unsigned long)ac->ac_o_ex.fe_logical, 5806 (unsigned long)ac->ac_g_ex.fe_group, 5807 (unsigned long)ac->ac_g_ex.fe_start, 5808 (unsigned long)ac->ac_g_ex.fe_len, 5809 (unsigned long)ac->ac_g_ex.fe_logical, 5810 (unsigned long)ac->ac_b_ex.fe_group, 5811 (unsigned long)ac->ac_b_ex.fe_start, 5812 (unsigned long)ac->ac_b_ex.fe_len, 5813 (unsigned long)ac->ac_b_ex.fe_logical, 5814 (int)ac->ac_criteria); 5815 mb_debug(sb, "%u found", ac->ac_found); 5816 mb_debug(sb, "used pa: %s, ", str_yes_no(ac->ac_pa)); 5817 if (ac->ac_pa) 5818 mb_debug(sb, "pa_type %s\n", ac->ac_pa->pa_type == MB_GROUP_PA ? 5819 "group pa" : "inode pa"); 5820 ext4_mb_show_pa(sb); 5821} 5822#else 5823static inline void ext4_mb_show_pa(struct super_block *sb) 5824{ 5825} 5826static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac) 5827{ 5828 ext4_mb_show_pa(ac->ac_sb); 5829} 5830#endif 5831 5832/* 5833 * We use locality group preallocation for small size file. The size of the 5834 * file is determined by the current size or the resulting size after 5835 * allocation which ever is larger 5836 * 5837 * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req 5838 */ 5839static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) 5840{ 5841 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 5842 int bsbits = ac->ac_sb->s_blocksize_bits; 5843 loff_t size, isize; 5844 bool inode_pa_eligible, group_pa_eligible; 5845 5846 if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) 5847 return; 5848 5849 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) 5850 return; 5851 5852 group_pa_eligible = sbi->s_mb_group_prealloc > 0; 5853 inode_pa_eligible = true; 5854 size = extent_logical_end(sbi, &ac->ac_o_ex); 5855 isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1) 5856 >> bsbits; 5857 5858 /* No point in using inode preallocation for closed files */ 5859 if ((size == isize) && !ext4_fs_is_busy(sbi) && 5860 !inode_is_open_for_write(ac->ac_inode)) 5861 inode_pa_eligible = false; 5862 5863 size = max(size, isize); 5864 /* Don't use group allocation for large files */ 5865 if (size > sbi->s_mb_stream_request) 5866 group_pa_eligible = false; 5867 5868 if (!group_pa_eligible) { 5869 if (inode_pa_eligible) 5870 ac->ac_flags |= EXT4_MB_STREAM_ALLOC; 5871 else 5872 ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC; 5873 return; 5874 } 5875 5876 BUG_ON(ac->ac_lg != NULL); 5877 /* 5878 * locality group prealloc space are per cpu. The reason for having 5879 * per cpu locality group is to reduce the contention between block 5880 * request from multiple CPUs. 5881 */ 5882 ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups); 5883 5884 /* we're going to use group allocation */ 5885 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC; 5886 5887 /* serialize all allocations in the group */ 5888 mutex_lock(&ac->ac_lg->lg_mutex); 5889} 5890 5891static noinline_for_stack void 5892ext4_mb_initialize_context(struct ext4_allocation_context *ac, 5893 struct ext4_allocation_request *ar) 5894{ 5895 struct super_block *sb = ar->inode->i_sb; 5896 struct ext4_sb_info *sbi = EXT4_SB(sb); 5897 struct ext4_super_block *es = sbi->s_es; 5898 ext4_group_t group; 5899 unsigned int len; 5900 ext4_fsblk_t goal; 5901 ext4_grpblk_t block; 5902 5903 /* we can't allocate > group size */ 5904 len = ar->len; 5905 5906 /* just a dirty hack to filter too big requests */ 5907 if (len >= EXT4_CLUSTERS_PER_GROUP(sb)) 5908 len = EXT4_CLUSTERS_PER_GROUP(sb); 5909 5910 /* start searching from the goal */ 5911 goal = ar->goal; 5912 if (goal < le32_to_cpu(es->s_first_data_block) || 5913 goal >= ext4_blocks_count(es)) 5914 goal = le32_to_cpu(es->s_first_data_block); 5915 ext4_get_group_no_and_offset(sb, goal, &group, &block); 5916 5917 /* set up allocation goals */ 5918 ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical); 5919 ac->ac_status = AC_STATUS_CONTINUE; 5920 ac->ac_sb = sb; 5921 ac->ac_inode = ar->inode; 5922 ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical; 5923 ac->ac_o_ex.fe_group = group; 5924 ac->ac_o_ex.fe_start = block; 5925 ac->ac_o_ex.fe_len = len; 5926 ac->ac_g_ex = ac->ac_o_ex; 5927 ac->ac_orig_goal_len = ac->ac_g_ex.fe_len; 5928 ac->ac_flags = ar->flags; 5929 5930 /* we have to define context: we'll work with a file or 5931 * locality group. this is a policy, actually */ 5932 ext4_mb_group_or_file(ac); 5933 5934 mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, " 5935 "left: %u/%u, right %u/%u to %swritable\n", 5936 (unsigned) ar->len, (unsigned) ar->logical, 5937 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order, 5938 (unsigned) ar->lleft, (unsigned) ar->pleft, 5939 (unsigned) ar->lright, (unsigned) ar->pright, 5940 inode_is_open_for_write(ar->inode) ? "" : "non-"); 5941} 5942 5943static noinline_for_stack void 5944ext4_mb_discard_lg_preallocations(struct super_block *sb, 5945 struct ext4_locality_group *lg, 5946 int order, int total_entries) 5947{ 5948 ext4_group_t group = 0; 5949 struct ext4_buddy e4b; 5950 LIST_HEAD(discard_list); 5951 struct ext4_prealloc_space *pa, *tmp; 5952 5953 mb_debug(sb, "discard locality group preallocation\n"); 5954 5955 spin_lock(&lg->lg_prealloc_lock); 5956 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order], 5957 pa_node.lg_list, 5958 lockdep_is_held(&lg->lg_prealloc_lock)) { 5959 spin_lock(&pa->pa_lock); 5960 if (atomic_read(&pa->pa_count)) { 5961 /* 5962 * This is the pa that we just used 5963 * for block allocation. So don't 5964 * free that 5965 */ 5966 spin_unlock(&pa->pa_lock); 5967 continue; 5968 } 5969 if (pa->pa_deleted) { 5970 spin_unlock(&pa->pa_lock); 5971 continue; 5972 } 5973 /* only lg prealloc space */ 5974 BUG_ON(pa->pa_type != MB_GROUP_PA); 5975 5976 /* seems this one can be freed ... */ 5977 ext4_mb_mark_pa_deleted(sb, pa); 5978 spin_unlock(&pa->pa_lock); 5979 5980 list_del_rcu(&pa->pa_node.lg_list); 5981 list_add(&pa->u.pa_tmp_list, &discard_list); 5982 5983 total_entries--; 5984 if (total_entries <= 5) { 5985 /* 5986 * we want to keep only 5 entries 5987 * allowing it to grow to 8. This 5988 * mak sure we don't call discard 5989 * soon for this list. 5990 */ 5991 break; 5992 } 5993 } 5994 spin_unlock(&lg->lg_prealloc_lock); 5995 5996 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) { 5997 int err; 5998 5999 group = ext4_get_group_number(sb, pa->pa_pstart); 6000 err = ext4_mb_load_buddy_gfp(sb, group, &e4b, 6001 GFP_NOFS|__GFP_NOFAIL); 6002 if (err) { 6003 ext4_error_err(sb, -err, "Error %d loading buddy information for %u", 6004 err, group); 6005 continue; 6006 } 6007 ext4_lock_group(sb, group); 6008 list_del(&pa->pa_group_list); 6009 ext4_mb_release_group_pa(&e4b, pa); 6010 ext4_unlock_group(sb, group); 6011 6012 ext4_mb_unload_buddy(&e4b); 6013 list_del(&pa->u.pa_tmp_list); 6014 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); 6015 } 6016} 6017 6018/* 6019 * We have incremented pa_count. So it cannot be freed at this 6020 * point. Also we hold lg_mutex. So no parallel allocation is 6021 * possible from this lg. That means pa_free cannot be updated. 6022 * 6023 * A parallel ext4_mb_discard_group_preallocations is possible. 6024 * which can cause the lg_prealloc_list to be updated. 6025 */ 6026 6027static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac) 6028{ 6029 int order, added = 0, lg_prealloc_count = 1; 6030 struct super_block *sb = ac->ac_sb; 6031 struct ext4_locality_group *lg = ac->ac_lg; 6032 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa; 6033 6034 order = fls(pa->pa_free) - 1; 6035 if (order > PREALLOC_TB_SIZE - 1) 6036 /* The max size of hash table is PREALLOC_TB_SIZE */ 6037 order = PREALLOC_TB_SIZE - 1; 6038 /* Add the prealloc space to lg */ 6039 spin_lock(&lg->lg_prealloc_lock); 6040 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], 6041 pa_node.lg_list, 6042 lockdep_is_held(&lg->lg_prealloc_lock)) { 6043 spin_lock(&tmp_pa->pa_lock); 6044 if (tmp_pa->pa_deleted) { 6045 spin_unlock(&tmp_pa->pa_lock); 6046 continue; 6047 } 6048 if (!added && pa->pa_free < tmp_pa->pa_free) { 6049 /* Add to the tail of the previous entry */ 6050 list_add_tail_rcu(&pa->pa_node.lg_list, 6051 &tmp_pa->pa_node.lg_list); 6052 added = 1; 6053 /* 6054 * we want to count the total 6055 * number of entries in the list 6056 */ 6057 } 6058 spin_unlock(&tmp_pa->pa_lock); 6059 lg_prealloc_count++; 6060 } 6061 if (!added) 6062 list_add_tail_rcu(&pa->pa_node.lg_list, 6063 &lg->lg_prealloc_list[order]); 6064 spin_unlock(&lg->lg_prealloc_lock); 6065 6066 /* Now trim the list to be not more than 8 elements */ 6067 if (lg_prealloc_count > 8) 6068 ext4_mb_discard_lg_preallocations(sb, lg, 6069 order, lg_prealloc_count); 6070} 6071 6072/* 6073 * release all resource we used in allocation 6074 */ 6075static void ext4_mb_release_context(struct ext4_allocation_context *ac) 6076{ 6077 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); 6078 struct ext4_prealloc_space *pa = ac->ac_pa; 6079 if (pa) { 6080 if (pa->pa_type == MB_GROUP_PA) { 6081 /* see comment in ext4_mb_use_group_pa() */ 6082 spin_lock(&pa->pa_lock); 6083 pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); 6084 pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); 6085 pa->pa_free -= ac->ac_b_ex.fe_len; 6086 pa->pa_len -= ac->ac_b_ex.fe_len; 6087 spin_unlock(&pa->pa_lock); 6088 6089 /* 6090 * We want to add the pa to the right bucket. 6091 * Remove it from the list and while adding 6092 * make sure the list to which we are adding 6093 * doesn't grow big. 6094 */ 6095 if (likely(pa->pa_free)) { 6096 spin_lock(pa->pa_node_lock.lg_lock); 6097 list_del_rcu(&pa->pa_node.lg_list); 6098 spin_unlock(pa->pa_node_lock.lg_lock); 6099 ext4_mb_add_n_trim(ac); 6100 } 6101 } 6102 6103 ext4_mb_put_pa(ac, ac->ac_sb, pa); 6104 } 6105 if (ac->ac_bitmap_folio) 6106 folio_put(ac->ac_bitmap_folio); 6107 if (ac->ac_buddy_folio) 6108 folio_put(ac->ac_buddy_folio); 6109 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) 6110 mutex_unlock(&ac->ac_lg->lg_mutex); 6111 ext4_mb_collect_stats(ac); 6112} 6113 6114static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) 6115{ 6116 ext4_group_t i, ngroups = ext4_get_groups_count(sb); 6117 int ret; 6118 int freed = 0, busy = 0; 6119 int retry = 0; 6120 6121 trace_ext4_mb_discard_preallocations(sb, needed); 6122 6123 if (needed == 0) 6124 needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1; 6125 repeat: 6126 for (i = 0; i < ngroups && needed > 0; i++) { 6127 ret = ext4_mb_discard_group_preallocations(sb, i, &busy); 6128 freed += ret; 6129 needed -= ret; 6130 cond_resched(); 6131 } 6132 6133 if (needed > 0 && busy && ++retry < 3) { 6134 busy = 0; 6135 goto repeat; 6136 } 6137 6138 return freed; 6139} 6140 6141static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb, 6142 struct ext4_allocation_context *ac, u64 *seq) 6143{ 6144 int freed; 6145 u64 seq_retry = 0; 6146 bool ret = false; 6147 6148 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len); 6149 if (freed) { 6150 ret = true; 6151 goto out_dbg; 6152 } 6153 seq_retry = ext4_get_discard_pa_seq_sum(); 6154 if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) { 6155 ac->ac_flags |= EXT4_MB_STRICT_CHECK; 6156 *seq = seq_retry; 6157 ret = true; 6158 } 6159 6160out_dbg: 6161 mb_debug(sb, "freed %d, retry ? %s\n", freed, str_yes_no(ret)); 6162 return ret; 6163} 6164 6165/* 6166 * Simple allocator for Ext4 fast commit replay path. It searches for blocks 6167 * linearly starting at the goal block and also excludes the blocks which 6168 * are going to be in use after fast commit replay. 6169 */ 6170static ext4_fsblk_t 6171ext4_mb_new_blocks_simple(struct ext4_allocation_request *ar, int *errp) 6172{ 6173 struct buffer_head *bitmap_bh; 6174 struct super_block *sb = ar->inode->i_sb; 6175 struct ext4_sb_info *sbi = EXT4_SB(sb); 6176 ext4_group_t group, nr; 6177 ext4_grpblk_t blkoff; 6178 ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); 6179 ext4_grpblk_t i = 0; 6180 ext4_fsblk_t goal, block; 6181 struct ext4_super_block *es = sbi->s_es; 6182 6183 goal = ar->goal; 6184 if (goal < le32_to_cpu(es->s_first_data_block) || 6185 goal >= ext4_blocks_count(es)) 6186 goal = le32_to_cpu(es->s_first_data_block); 6187 6188 ar->len = 0; 6189 ext4_get_group_no_and_offset(sb, goal, &group, &blkoff); 6190 for (nr = ext4_get_groups_count(sb); nr > 0; nr--) { 6191 bitmap_bh = ext4_read_block_bitmap(sb, group); 6192 if (IS_ERR(bitmap_bh)) { 6193 *errp = PTR_ERR(bitmap_bh); 6194 pr_warn("Failed to read block bitmap\n"); 6195 return 0; 6196 } 6197 6198 while (1) { 6199 i = mb_find_next_zero_bit(bitmap_bh->b_data, max, 6200 blkoff); 6201 if (i >= max) 6202 break; 6203 if (ext4_fc_replay_check_excluded(sb, 6204 ext4_group_first_block_no(sb, group) + 6205 EXT4_C2B(sbi, i))) { 6206 blkoff = i + 1; 6207 } else 6208 break; 6209 } 6210 brelse(bitmap_bh); 6211 if (i < max) 6212 break; 6213 6214 if (++group >= ext4_get_groups_count(sb)) 6215 group = 0; 6216 6217 blkoff = 0; 6218 } 6219 6220 if (i >= max) { 6221 *errp = -ENOSPC; 6222 return 0; 6223 } 6224 6225 block = ext4_group_first_block_no(sb, group) + EXT4_C2B(sbi, i); 6226 ext4_mb_mark_bb(sb, block, 1, true); 6227 ar->len = 1; 6228 6229 *errp = 0; 6230 return block; 6231} 6232 6233/* 6234 * Main entry point into mballoc to allocate blocks 6235 * it tries to use preallocation first, then falls back 6236 * to usual allocation 6237 */ 6238ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, 6239 struct ext4_allocation_request *ar, int *errp) 6240{ 6241 struct ext4_allocation_context *ac = NULL; 6242 struct ext4_sb_info *sbi; 6243 struct super_block *sb; 6244 ext4_fsblk_t block = 0; 6245 unsigned int inquota = 0; 6246 unsigned int reserv_clstrs = 0; 6247 int retries = 0; 6248 u64 seq; 6249 6250 might_sleep(); 6251 sb = ar->inode->i_sb; 6252 sbi = EXT4_SB(sb); 6253 6254 trace_ext4_request_blocks(ar); 6255 if (sbi->s_mount_state & EXT4_FC_REPLAY) 6256 return ext4_mb_new_blocks_simple(ar, errp); 6257 6258 /* Allow to use superuser reservation for quota file */ 6259 if (ext4_is_quota_file(ar->inode)) 6260 ar->flags |= EXT4_MB_USE_ROOT_BLOCKS; 6261 6262 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) { 6263 /* Without delayed allocation we need to verify 6264 * there is enough free blocks to do block allocation 6265 * and verify allocation doesn't exceed the quota limits. 6266 */ 6267 while (ar->len && 6268 ext4_claim_free_clusters(sbi, ar->len, ar->flags)) { 6269 6270 /* let others to free the space */ 6271 cond_resched(); 6272 ar->len = ar->len >> 1; 6273 } 6274 if (!ar->len) { 6275 ext4_mb_show_pa(sb); 6276 *errp = -ENOSPC; 6277 return 0; 6278 } 6279 reserv_clstrs = ar->len; 6280 if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) { 6281 dquot_alloc_block_nofail(ar->inode, 6282 EXT4_C2B(sbi, ar->len)); 6283 } else { 6284 while (ar->len && 6285 dquot_alloc_block(ar->inode, 6286 EXT4_C2B(sbi, ar->len))) { 6287 6288 ar->flags |= EXT4_MB_HINT_NOPREALLOC; 6289 ar->len--; 6290 } 6291 } 6292 inquota = ar->len; 6293 if (ar->len == 0) { 6294 *errp = -EDQUOT; 6295 goto out; 6296 } 6297 } 6298 6299 ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS); 6300 if (!ac) { 6301 ar->len = 0; 6302 *errp = -ENOMEM; 6303 goto out; 6304 } 6305 6306 ext4_mb_initialize_context(ac, ar); 6307 6308 ac->ac_op = EXT4_MB_HISTORY_PREALLOC; 6309 seq = this_cpu_read(discard_pa_seq); 6310 if (!ext4_mb_use_preallocated(ac)) { 6311 ac->ac_op = EXT4_MB_HISTORY_ALLOC; 6312 ext4_mb_normalize_request(ac, ar); 6313 6314 *errp = ext4_mb_pa_alloc(ac); 6315 if (*errp) 6316 goto errout; 6317repeat: 6318 /* allocate space in core */ 6319 *errp = ext4_mb_regular_allocator(ac); 6320 /* 6321 * pa allocated above is added to grp->bb_prealloc_list only 6322 * when we were able to allocate some block i.e. when 6323 * ac->ac_status == AC_STATUS_FOUND. 6324 * And error from above mean ac->ac_status != AC_STATUS_FOUND 6325 * So we have to free this pa here itself. 6326 */ 6327 if (*errp) { 6328 ext4_mb_pa_put_free(ac); 6329 ext4_discard_allocated_blocks(ac); 6330 goto errout; 6331 } 6332 if (ac->ac_status == AC_STATUS_FOUND && 6333 ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len) 6334 ext4_mb_pa_put_free(ac); 6335 } 6336 if (likely(ac->ac_status == AC_STATUS_FOUND)) { 6337 *errp = ext4_mb_mark_diskspace_used(ac, handle); 6338 if (*errp) { 6339 ext4_discard_allocated_blocks(ac); 6340 goto errout; 6341 } else { 6342 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); 6343 ar->len = ac->ac_b_ex.fe_len; 6344 } 6345 } else { 6346 if (++retries < 3 && 6347 ext4_mb_discard_preallocations_should_retry(sb, ac, &seq)) 6348 goto repeat; 6349 /* 6350 * If block allocation fails then the pa allocated above 6351 * needs to be freed here itself. 6352 */ 6353 ext4_mb_pa_put_free(ac); 6354 *errp = -ENOSPC; 6355 } 6356 6357 if (*errp) { 6358errout: 6359 ac->ac_b_ex.fe_len = 0; 6360 ar->len = 0; 6361 ext4_mb_show_ac(ac); 6362 } 6363 ext4_mb_release_context(ac); 6364 kmem_cache_free(ext4_ac_cachep, ac); 6365out: 6366 if (inquota && ar->len < inquota) 6367 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len)); 6368 /* release any reserved blocks */ 6369 if (reserv_clstrs) 6370 percpu_counter_sub(&sbi->s_dirtyclusters_counter, reserv_clstrs); 6371 6372 trace_ext4_allocate_blocks(ar, (unsigned long long)block); 6373 6374 return block; 6375} 6376 6377/* 6378 * We can merge two free data extents only if the physical blocks 6379 * are contiguous, AND the extents were freed by the same transaction, 6380 * AND the blocks are associated with the same group. 6381 */ 6382static inline bool 6383ext4_freed_extents_can_be_merged(struct ext4_free_data *entry1, 6384 struct ext4_free_data *entry2) 6385{ 6386 if (entry1->efd_tid != entry2->efd_tid) 6387 return false; 6388 if (entry1->efd_start_cluster + entry1->efd_count != 6389 entry2->efd_start_cluster) 6390 return false; 6391 if (WARN_ON_ONCE(entry1->efd_group != entry2->efd_group)) 6392 return false; 6393 return true; 6394} 6395 6396static inline void 6397ext4_merge_freed_extents(struct ext4_sb_info *sbi, struct rb_root *root, 6398 struct ext4_free_data *entry1, 6399 struct ext4_free_data *entry2) 6400{ 6401 entry1->efd_count += entry2->efd_count; 6402 spin_lock(&sbi->s_md_lock); 6403 list_del(&entry2->efd_list); 6404 spin_unlock(&sbi->s_md_lock); 6405 rb_erase(&entry2->efd_node, root); 6406 kmem_cache_free(ext4_free_data_cachep, entry2); 6407} 6408 6409static inline void 6410ext4_try_merge_freed_extent_prev(struct ext4_sb_info *sbi, struct rb_root *root, 6411 struct ext4_free_data *entry) 6412{ 6413 struct ext4_free_data *prev; 6414 struct rb_node *node; 6415 6416 node = rb_prev(&entry->efd_node); 6417 if (!node) 6418 return; 6419 6420 prev = rb_entry(node, struct ext4_free_data, efd_node); 6421 if (ext4_freed_extents_can_be_merged(prev, entry)) 6422 ext4_merge_freed_extents(sbi, root, prev, entry); 6423} 6424 6425static inline void 6426ext4_try_merge_freed_extent_next(struct ext4_sb_info *sbi, struct rb_root *root, 6427 struct ext4_free_data *entry) 6428{ 6429 struct ext4_free_data *next; 6430 struct rb_node *node; 6431 6432 node = rb_next(&entry->efd_node); 6433 if (!node) 6434 return; 6435 6436 next = rb_entry(node, struct ext4_free_data, efd_node); 6437 if (ext4_freed_extents_can_be_merged(entry, next)) 6438 ext4_merge_freed_extents(sbi, root, entry, next); 6439} 6440 6441static noinline_for_stack void 6442ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, 6443 struct ext4_free_data *new_entry) 6444{ 6445 ext4_group_t group = e4b->bd_group; 6446 ext4_grpblk_t cluster; 6447 ext4_grpblk_t clusters = new_entry->efd_count; 6448 struct ext4_free_data *entry = NULL; 6449 struct ext4_group_info *db = e4b->bd_info; 6450 struct super_block *sb = e4b->bd_sb; 6451 struct ext4_sb_info *sbi = EXT4_SB(sb); 6452 struct rb_root *root = &db->bb_free_root; 6453 struct rb_node **n = &root->rb_node; 6454 struct rb_node *parent = NULL, *new_node; 6455 6456 BUG_ON(!ext4_handle_valid(handle)); 6457 BUG_ON(e4b->bd_bitmap_folio == NULL); 6458 BUG_ON(e4b->bd_buddy_folio == NULL); 6459 6460 new_node = &new_entry->efd_node; 6461 cluster = new_entry->efd_start_cluster; 6462 6463 if (!*n) { 6464 /* first free block exent. We need to 6465 protect buddy cache from being freed, 6466 * otherwise we'll refresh it from 6467 * on-disk bitmap and lose not-yet-available 6468 * blocks */ 6469 folio_get(e4b->bd_buddy_folio); 6470 folio_get(e4b->bd_bitmap_folio); 6471 } 6472 while (*n) { 6473 parent = *n; 6474 entry = rb_entry(parent, struct ext4_free_data, efd_node); 6475 if (cluster < entry->efd_start_cluster) 6476 n = &(*n)->rb_left; 6477 else if (cluster >= (entry->efd_start_cluster + entry->efd_count)) 6478 n = &(*n)->rb_right; 6479 else { 6480 ext4_grp_locked_error(sb, group, 0, 6481 ext4_group_first_block_no(sb, group) + 6482 EXT4_C2B(sbi, cluster), 6483 "Block already on to-be-freed list"); 6484 kmem_cache_free(ext4_free_data_cachep, new_entry); 6485 return; 6486 } 6487 } 6488 6489 atomic_add(clusters, &sbi->s_mb_free_pending); 6490 if (!entry) 6491 goto insert; 6492 6493 /* Now try to see the extent can be merged to prev and next */ 6494 if (ext4_freed_extents_can_be_merged(new_entry, entry)) { 6495 entry->efd_start_cluster = cluster; 6496 entry->efd_count += new_entry->efd_count; 6497 kmem_cache_free(ext4_free_data_cachep, new_entry); 6498 ext4_try_merge_freed_extent_prev(sbi, root, entry); 6499 return; 6500 } 6501 if (ext4_freed_extents_can_be_merged(entry, new_entry)) { 6502 entry->efd_count += new_entry->efd_count; 6503 kmem_cache_free(ext4_free_data_cachep, new_entry); 6504 ext4_try_merge_freed_extent_next(sbi, root, entry); 6505 return; 6506 } 6507insert: 6508 rb_link_node(new_node, parent, n); 6509 rb_insert_color(new_node, root); 6510 6511 spin_lock(&sbi->s_md_lock); 6512 list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list[new_entry->efd_tid & 1]); 6513 spin_unlock(&sbi->s_md_lock); 6514} 6515 6516static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block, 6517 unsigned long count) 6518{ 6519 struct super_block *sb = inode->i_sb; 6520 ext4_group_t group; 6521 ext4_grpblk_t blkoff; 6522 6523 ext4_get_group_no_and_offset(sb, block, &group, &blkoff); 6524 ext4_mb_mark_context(NULL, sb, false, group, blkoff, count, 6525 EXT4_MB_BITMAP_MARKED_CHECK | 6526 EXT4_MB_SYNC_UPDATE, 6527 NULL); 6528} 6529 6530/** 6531 * ext4_mb_clear_bb() -- helper function for freeing blocks. 6532 * Used by ext4_free_blocks() 6533 * @handle: handle for this transaction 6534 * @inode: inode 6535 * @block: starting physical block to be freed 6536 * @count: number of blocks to be freed 6537 * @flags: flags used by ext4_free_blocks 6538 */ 6539static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode, 6540 ext4_fsblk_t block, unsigned long count, 6541 int flags) 6542{ 6543 struct super_block *sb = inode->i_sb; 6544 struct ext4_group_info *grp; 6545 unsigned int overflow; 6546 ext4_grpblk_t bit; 6547 ext4_group_t block_group; 6548 struct ext4_sb_info *sbi; 6549 struct ext4_buddy e4b; 6550 unsigned int count_clusters; 6551 int err = 0; 6552 int mark_flags = 0; 6553 ext4_grpblk_t changed; 6554 6555 sbi = EXT4_SB(sb); 6556 6557 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && 6558 !ext4_inode_block_valid(inode, block, count)) { 6559 ext4_error(sb, "Freeing blocks in system zone - " 6560 "Block = %llu, count = %lu", block, count); 6561 /* err = 0. ext4_std_error should be a no op */ 6562 goto error_out; 6563 } 6564 flags |= EXT4_FREE_BLOCKS_VALIDATED; 6565 6566do_more: 6567 overflow = 0; 6568 ext4_get_group_no_and_offset(sb, block, &block_group, &bit); 6569 6570 grp = ext4_get_group_info(sb, block_group); 6571 if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) 6572 return; 6573 6574 /* 6575 * Check to see if we are freeing blocks across a group 6576 * boundary. 6577 */ 6578 if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) { 6579 overflow = EXT4_C2B(sbi, bit) + count - 6580 EXT4_BLOCKS_PER_GROUP(sb); 6581 count -= overflow; 6582 /* The range changed so it's no longer validated */ 6583 flags &= ~EXT4_FREE_BLOCKS_VALIDATED; 6584 } 6585 count_clusters = EXT4_NUM_B2C(sbi, count); 6586 trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters); 6587 6588 /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */ 6589 err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b, 6590 GFP_NOFS|__GFP_NOFAIL); 6591 if (err) 6592 goto error_out; 6593 6594 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && 6595 !ext4_inode_block_valid(inode, block, count)) { 6596 ext4_error(sb, "Freeing blocks in system zone - " 6597 "Block = %llu, count = %lu", block, count); 6598 /* err = 0. ext4_std_error should be a no op */ 6599 goto error_clean; 6600 } 6601 6602#ifdef AGGRESSIVE_CHECK 6603 mark_flags |= EXT4_MB_BITMAP_MARKED_CHECK; 6604#endif 6605 err = ext4_mb_mark_context(handle, sb, false, block_group, bit, 6606 count_clusters, mark_flags, &changed); 6607 6608 6609 if (err && changed == 0) 6610 goto error_clean; 6611 6612#ifdef AGGRESSIVE_CHECK 6613 BUG_ON(changed != count_clusters); 6614#endif 6615 6616 /* 6617 * We need to make sure we don't reuse the freed block until after the 6618 * transaction is committed. We make an exception if the inode is to be 6619 * written in writeback mode since writeback mode has weak data 6620 * consistency guarantees. 6621 */ 6622 if (ext4_handle_valid(handle) && 6623 ((flags & EXT4_FREE_BLOCKS_METADATA) || 6624 !ext4_should_writeback_data(inode))) { 6625 struct ext4_free_data *new_entry; 6626 /* 6627 * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed 6628 * to fail. 6629 */ 6630 new_entry = kmem_cache_alloc(ext4_free_data_cachep, 6631 GFP_NOFS|__GFP_NOFAIL); 6632 new_entry->efd_start_cluster = bit; 6633 new_entry->efd_group = block_group; 6634 new_entry->efd_count = count_clusters; 6635 new_entry->efd_tid = handle->h_transaction->t_tid; 6636 6637 ext4_lock_group(sb, block_group); 6638 ext4_mb_free_metadata(handle, &e4b, new_entry); 6639 } else { 6640 if (test_opt(sb, DISCARD)) { 6641 err = ext4_issue_discard(sb, block_group, bit, 6642 count_clusters); 6643 /* 6644 * Ignore EOPNOTSUPP error. This is consistent with 6645 * what happens when using journal. 6646 */ 6647 if (err == -EOPNOTSUPP) 6648 err = 0; 6649 if (err) 6650 ext4_msg(sb, KERN_WARNING, "discard request in" 6651 " group:%u block:%d count:%lu failed" 6652 " with %d", block_group, bit, count, 6653 err); 6654 } 6655 6656 EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info); 6657 6658 ext4_lock_group(sb, block_group); 6659 mb_free_blocks(inode, &e4b, bit, count_clusters); 6660 } 6661 6662 ext4_unlock_group(sb, block_group); 6663 6664 /* 6665 * on a bigalloc file system, defer the s_freeclusters_counter 6666 * update to the caller (ext4_remove_space and friends) so they 6667 * can determine if a cluster freed here should be rereserved 6668 */ 6669 if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) { 6670 if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE)) 6671 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters)); 6672 percpu_counter_add(&sbi->s_freeclusters_counter, 6673 count_clusters); 6674 } 6675 6676 if (overflow && !err) { 6677 block += count; 6678 count = overflow; 6679 ext4_mb_unload_buddy(&e4b); 6680 /* The range changed so it's no longer validated */ 6681 flags &= ~EXT4_FREE_BLOCKS_VALIDATED; 6682 goto do_more; 6683 } 6684 6685error_clean: 6686 ext4_mb_unload_buddy(&e4b); 6687error_out: 6688 ext4_std_error(sb, err); 6689} 6690 6691/** 6692 * ext4_free_blocks() -- Free given blocks and update quota 6693 * @handle: handle for this transaction 6694 * @inode: inode 6695 * @bh: optional buffer of the block to be freed 6696 * @block: starting physical block to be freed 6697 * @count: number of blocks to be freed 6698 * @flags: flags used by ext4_free_blocks 6699 */ 6700void ext4_free_blocks(handle_t *handle, struct inode *inode, 6701 struct buffer_head *bh, ext4_fsblk_t block, 6702 unsigned long count, int flags) 6703{ 6704 struct super_block *sb = inode->i_sb; 6705 unsigned int overflow; 6706 struct ext4_sb_info *sbi; 6707 6708 sbi = EXT4_SB(sb); 6709 6710 if (bh) { 6711 if (block) 6712 BUG_ON(block != bh->b_blocknr); 6713 else 6714 block = bh->b_blocknr; 6715 } 6716 6717 if (sbi->s_mount_state & EXT4_FC_REPLAY) { 6718 ext4_free_blocks_simple(inode, block, EXT4_NUM_B2C(sbi, count)); 6719 return; 6720 } 6721 6722 might_sleep(); 6723 6724 if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && 6725 !ext4_inode_block_valid(inode, block, count)) { 6726 ext4_error(sb, "Freeing blocks not in datazone - " 6727 "block = %llu, count = %lu", block, count); 6728 return; 6729 } 6730 flags |= EXT4_FREE_BLOCKS_VALIDATED; 6731 6732 ext4_debug("freeing block %llu\n", block); 6733 trace_ext4_free_blocks(inode, block, count, flags); 6734 6735 if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) { 6736 BUG_ON(count > 1); 6737 6738 ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA, 6739 inode, bh, block); 6740 } 6741 6742 /* 6743 * If the extent to be freed does not begin on a cluster 6744 * boundary, we need to deal with partial clusters at the 6745 * beginning and end of the extent. Normally we will free 6746 * blocks at the beginning or the end unless we are explicitly 6747 * requested to avoid doing so. 6748 */ 6749 overflow = EXT4_PBLK_COFF(sbi, block); 6750 if (overflow) { 6751 if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) { 6752 overflow = sbi->s_cluster_ratio - overflow; 6753 block += overflow; 6754 if (count > overflow) 6755 count -= overflow; 6756 else 6757 return; 6758 } else { 6759 block -= overflow; 6760 count += overflow; 6761 } 6762 /* The range changed so it's no longer validated */ 6763 flags &= ~EXT4_FREE_BLOCKS_VALIDATED; 6764 } 6765 overflow = EXT4_LBLK_COFF(sbi, count); 6766 if (overflow) { 6767 if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) { 6768 if (count > overflow) 6769 count -= overflow; 6770 else 6771 return; 6772 } else 6773 count += sbi->s_cluster_ratio - overflow; 6774 /* The range changed so it's no longer validated */ 6775 flags &= ~EXT4_FREE_BLOCKS_VALIDATED; 6776 } 6777 6778 if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) { 6779 int i; 6780 int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA; 6781 6782 for (i = 0; i < count; i++) { 6783 cond_resched(); 6784 if (is_metadata) 6785 bh = sb_find_get_block_nonatomic(inode->i_sb, 6786 block + i); 6787 ext4_forget(handle, is_metadata, inode, bh, block + i); 6788 } 6789 } 6790 6791 ext4_mb_clear_bb(handle, inode, block, count, flags); 6792} 6793 6794/** 6795 * ext4_group_add_blocks() -- Add given blocks to an existing group 6796 * @handle: handle to this transaction 6797 * @sb: super block 6798 * @block: start physical block to add to the block group 6799 * @count: number of blocks to free 6800 * 6801 * This marks the blocks as free in the bitmap and buddy. 6802 */ 6803int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, 6804 ext4_fsblk_t block, unsigned long count) 6805{ 6806 ext4_group_t block_group; 6807 ext4_grpblk_t bit; 6808 struct ext4_sb_info *sbi = EXT4_SB(sb); 6809 struct ext4_buddy e4b; 6810 int err = 0; 6811 ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block); 6812 ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1); 6813 unsigned long cluster_count = last_cluster - first_cluster + 1; 6814 ext4_grpblk_t changed; 6815 6816 ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1); 6817 6818 if (cluster_count == 0) 6819 return 0; 6820 6821 ext4_get_group_no_and_offset(sb, block, &block_group, &bit); 6822 /* 6823 * Check to see if we are freeing blocks across a group 6824 * boundary. 6825 */ 6826 if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) { 6827 ext4_warning(sb, "too many blocks added to group %u", 6828 block_group); 6829 err = -EINVAL; 6830 goto error_out; 6831 } 6832 6833 err = ext4_mb_load_buddy(sb, block_group, &e4b); 6834 if (err) 6835 goto error_out; 6836 6837 if (!ext4_sb_block_valid(sb, NULL, block, count)) { 6838 ext4_error(sb, "Adding blocks in system zones - " 6839 "Block = %llu, count = %lu", 6840 block, count); 6841 err = -EINVAL; 6842 goto error_clean; 6843 } 6844 6845 err = ext4_mb_mark_context(handle, sb, false, block_group, bit, 6846 cluster_count, EXT4_MB_BITMAP_MARKED_CHECK, 6847 &changed); 6848 if (err && changed == 0) 6849 goto error_clean; 6850 6851 if (changed != cluster_count) 6852 ext4_error(sb, "bit already cleared in group %u", block_group); 6853 6854 ext4_lock_group(sb, block_group); 6855 mb_free_blocks(NULL, &e4b, bit, cluster_count); 6856 ext4_unlock_group(sb, block_group); 6857 percpu_counter_add(&sbi->s_freeclusters_counter, 6858 changed); 6859 6860error_clean: 6861 ext4_mb_unload_buddy(&e4b); 6862error_out: 6863 ext4_std_error(sb, err); 6864 return err; 6865} 6866 6867/** 6868 * ext4_trim_extent -- function to TRIM one single free extent in the group 6869 * @sb: super block for the file system 6870 * @start: starting block of the free extent in the alloc. group 6871 * @count: number of blocks to TRIM 6872 * @e4b: ext4 buddy for the group 6873 * 6874 * Trim "count" blocks starting at "start" in the "group". To assure that no 6875 * one will allocate those blocks, mark it as used in buddy bitmap. This must 6876 * be called with under the group lock. 6877 */ 6878static int ext4_trim_extent(struct super_block *sb, 6879 int start, int count, struct ext4_buddy *e4b) 6880__releases(bitlock) 6881__acquires(bitlock) 6882{ 6883 struct ext4_free_extent ex; 6884 ext4_group_t group = e4b->bd_group; 6885 int ret = 0; 6886 6887 trace_ext4_trim_extent(sb, group, start, count); 6888 6889 assert_spin_locked(ext4_group_lock_ptr(sb, group)); 6890 6891 ex.fe_start = start; 6892 ex.fe_group = group; 6893 ex.fe_len = count; 6894 6895 /* 6896 * Mark blocks used, so no one can reuse them while 6897 * being trimmed. 6898 */ 6899 mb_mark_used(e4b, &ex); 6900 ext4_unlock_group(sb, group); 6901 ret = ext4_issue_discard(sb, group, start, count); 6902 ext4_lock_group(sb, group); 6903 mb_free_blocks(NULL, e4b, start, ex.fe_len); 6904 return ret; 6905} 6906 6907static ext4_grpblk_t ext4_last_grp_cluster(struct super_block *sb, 6908 ext4_group_t grp) 6909{ 6910 unsigned long nr_clusters_in_group; 6911 6912 if (grp < (ext4_get_groups_count(sb) - 1)) 6913 nr_clusters_in_group = EXT4_CLUSTERS_PER_GROUP(sb); 6914 else 6915 nr_clusters_in_group = (ext4_blocks_count(EXT4_SB(sb)->s_es) - 6916 ext4_group_first_block_no(sb, grp)) 6917 >> EXT4_CLUSTER_BITS(sb); 6918 6919 return nr_clusters_in_group - 1; 6920} 6921 6922static bool ext4_trim_interrupted(void) 6923{ 6924 return fatal_signal_pending(current) || freezing(current); 6925} 6926 6927static int ext4_try_to_trim_range(struct super_block *sb, 6928 struct ext4_buddy *e4b, ext4_grpblk_t start, 6929 ext4_grpblk_t max, ext4_grpblk_t minblocks) 6930__acquires(ext4_group_lock_ptr(sb, e4b->bd_group)) 6931__releases(ext4_group_lock_ptr(sb, e4b->bd_group)) 6932{ 6933 ext4_grpblk_t next, count, free_count, last, origin_start; 6934 bool set_trimmed = false; 6935 void *bitmap; 6936 6937 if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) 6938 return 0; 6939 6940 last = ext4_last_grp_cluster(sb, e4b->bd_group); 6941 bitmap = e4b->bd_bitmap; 6942 if (start == 0 && max >= last) 6943 set_trimmed = true; 6944 origin_start = start; 6945 start = max(e4b->bd_info->bb_first_free, start); 6946 count = 0; 6947 free_count = 0; 6948 6949 while (start <= max) { 6950 start = mb_find_next_zero_bit(bitmap, max + 1, start); 6951 if (start > max) 6952 break; 6953 6954 next = mb_find_next_bit(bitmap, last + 1, start); 6955 if (origin_start == 0 && next >= last) 6956 set_trimmed = true; 6957 6958 if ((next - start) >= minblocks) { 6959 int ret = ext4_trim_extent(sb, start, next - start, e4b); 6960 6961 if (ret && ret != -EOPNOTSUPP) 6962 return count; 6963 count += next - start; 6964 } 6965 free_count += next - start; 6966 start = next + 1; 6967 6968 if (ext4_trim_interrupted()) 6969 return count; 6970 6971 if (need_resched()) { 6972 ext4_unlock_group(sb, e4b->bd_group); 6973 cond_resched(); 6974 ext4_lock_group(sb, e4b->bd_group); 6975 } 6976 6977 if ((e4b->bd_info->bb_free - free_count) < minblocks) 6978 break; 6979 } 6980 6981 if (set_trimmed) 6982 EXT4_MB_GRP_SET_TRIMMED(e4b->bd_info); 6983 6984 return count; 6985} 6986 6987/** 6988 * ext4_trim_all_free -- function to trim all free space in alloc. group 6989 * @sb: super block for file system 6990 * @group: group to be trimmed 6991 * @start: first group block to examine 6992 * @max: last group block to examine 6993 * @minblocks: minimum extent block count 6994 * 6995 * ext4_trim_all_free walks through group's block bitmap searching for free 6996 * extents. When the free extent is found, mark it as used in group buddy 6997 * bitmap. Then issue a TRIM command on this extent and free the extent in 6998 * the group buddy bitmap. 6999 */ 7000static ext4_grpblk_t 7001ext4_trim_all_free(struct super_block *sb, ext4_group_t group, 7002 ext4_grpblk_t start, ext4_grpblk_t max, 7003 ext4_grpblk_t minblocks) 7004{ 7005 struct ext4_buddy e4b; 7006 int ret; 7007 7008 trace_ext4_trim_all_free(sb, group, start, max); 7009 7010 ret = ext4_mb_load_buddy(sb, group, &e4b); 7011 if (ret) { 7012 ext4_warning(sb, "Error %d loading buddy information for %u", 7013 ret, group); 7014 return ret; 7015 } 7016 7017 ext4_lock_group(sb, group); 7018 7019 if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) || 7020 minblocks < EXT4_SB(sb)->s_last_trim_minblks) 7021 ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks); 7022 else 7023 ret = 0; 7024 7025 ext4_unlock_group(sb, group); 7026 ext4_mb_unload_buddy(&e4b); 7027 7028 ext4_debug("trimmed %d blocks in the group %d\n", 7029 ret, group); 7030 7031 return ret; 7032} 7033 7034/** 7035 * ext4_trim_fs() -- trim ioctl handle function 7036 * @sb: superblock for filesystem 7037 * @range: fstrim_range structure 7038 * 7039 * start: First Byte to trim 7040 * len: number of Bytes to trim from start 7041 * minlen: minimum extent length in Bytes 7042 * ext4_trim_fs goes through all allocation groups containing Bytes from 7043 * start to start+len. For each such a group ext4_trim_all_free function 7044 * is invoked to trim all free space. 7045 */ 7046int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) 7047{ 7048 unsigned int discard_granularity = bdev_discard_granularity(sb->s_bdev); 7049 struct ext4_group_info *grp; 7050 ext4_group_t group, first_group, last_group; 7051 ext4_grpblk_t cnt = 0, first_cluster, last_cluster; 7052 uint64_t start, end, minlen, trimmed = 0; 7053 ext4_fsblk_t first_data_blk = 7054 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); 7055 ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es); 7056 int ret = 0; 7057 7058 start = range->start >> sb->s_blocksize_bits; 7059 end = start + (range->len >> sb->s_blocksize_bits) - 1; 7060 minlen = EXT4_NUM_B2C(EXT4_SB(sb), 7061 range->minlen >> sb->s_blocksize_bits); 7062 7063 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) || 7064 start >= max_blks || 7065 range->len < sb->s_blocksize) 7066 return -EINVAL; 7067 /* No point to try to trim less than discard granularity */ 7068 if (range->minlen < discard_granularity) { 7069 minlen = EXT4_NUM_B2C(EXT4_SB(sb), 7070 discard_granularity >> sb->s_blocksize_bits); 7071 if (minlen > EXT4_CLUSTERS_PER_GROUP(sb)) 7072 goto out; 7073 } 7074 if (end >= max_blks - 1) 7075 end = max_blks - 1; 7076 if (end <= first_data_blk) 7077 goto out; 7078 if (start < first_data_blk) 7079 start = first_data_blk; 7080 7081 /* Determine first and last group to examine based on start and end */ 7082 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start, 7083 &first_group, &first_cluster); 7084 ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end, 7085 &last_group, &last_cluster); 7086 7087 /* end now represents the last cluster to discard in this group */ 7088 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; 7089 7090 for (group = first_group; group <= last_group; group++) { 7091 if (ext4_trim_interrupted()) 7092 break; 7093 grp = ext4_get_group_info(sb, group); 7094 if (!grp) 7095 continue; 7096 /* We only do this if the grp has never been initialized */ 7097 if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { 7098 ret = ext4_mb_init_group(sb, group, GFP_NOFS); 7099 if (ret) 7100 break; 7101 } 7102 7103 /* 7104 * For all the groups except the last one, last cluster will 7105 * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to 7106 * change it for the last group, note that last_cluster is 7107 * already computed earlier by ext4_get_group_no_and_offset() 7108 */ 7109 if (group == last_group) 7110 end = last_cluster; 7111 if (grp->bb_free >= minlen) { 7112 cnt = ext4_trim_all_free(sb, group, first_cluster, 7113 end, minlen); 7114 if (cnt < 0) { 7115 ret = cnt; 7116 break; 7117 } 7118 trimmed += cnt; 7119 } 7120 7121 /* 7122 * For every group except the first one, we are sure 7123 * that the first cluster to discard will be cluster #0. 7124 */ 7125 first_cluster = 0; 7126 } 7127 7128 if (!ret) 7129 EXT4_SB(sb)->s_last_trim_minblks = minlen; 7130 7131out: 7132 range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits; 7133 return ret; 7134} 7135 7136/* Iterate all the free extents in the group. */ 7137int 7138ext4_mballoc_query_range( 7139 struct super_block *sb, 7140 ext4_group_t group, 7141 ext4_grpblk_t first, 7142 ext4_grpblk_t end, 7143 ext4_mballoc_query_range_fn meta_formatter, 7144 ext4_mballoc_query_range_fn formatter, 7145 void *priv) 7146{ 7147 void *bitmap; 7148 ext4_grpblk_t start, next; 7149 struct ext4_buddy e4b; 7150 int error; 7151 7152 error = ext4_mb_load_buddy(sb, group, &e4b); 7153 if (error) 7154 return error; 7155 bitmap = e4b.bd_bitmap; 7156 7157 ext4_lock_group(sb, group); 7158 7159 start = max(e4b.bd_info->bb_first_free, first); 7160 if (end >= EXT4_CLUSTERS_PER_GROUP(sb)) 7161 end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; 7162 if (meta_formatter && start != first) { 7163 if (start > end) 7164 start = end; 7165 ext4_unlock_group(sb, group); 7166 error = meta_formatter(sb, group, first, start - first, 7167 priv); 7168 if (error) 7169 goto out_unload; 7170 ext4_lock_group(sb, group); 7171 } 7172 while (start <= end) { 7173 start = mb_find_next_zero_bit(bitmap, end + 1, start); 7174 if (start > end) 7175 break; 7176 next = mb_find_next_bit(bitmap, end + 1, start); 7177 7178 ext4_unlock_group(sb, group); 7179 error = formatter(sb, group, start, next - start, priv); 7180 if (error) 7181 goto out_unload; 7182 ext4_lock_group(sb, group); 7183 7184 start = next + 1; 7185 } 7186 7187 ext4_unlock_group(sb, group); 7188out_unload: 7189 ext4_mb_unload_buddy(&e4b); 7190 7191 return error; 7192} 7193 7194#if IS_ENABLED(CONFIG_EXT4_KUNIT_TESTS) 7195void mb_clear_bits_test(void *bm, int cur, int len) 7196{ 7197 mb_clear_bits(bm, cur, len); 7198} 7199EXPORT_SYMBOL_FOR_EXT4_TEST(mb_clear_bits_test); 7200 7201ext4_fsblk_t 7202ext4_mb_new_blocks_simple_test(struct ext4_allocation_request *ar, 7203 int *errp) 7204{ 7205 return ext4_mb_new_blocks_simple(ar, errp); 7206} 7207EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_new_blocks_simple_test); 7208 7209int mb_find_next_zero_bit_test(void *addr, int max, int start) 7210{ 7211 return mb_find_next_zero_bit(addr, max, start); 7212} 7213EXPORT_SYMBOL_FOR_EXT4_TEST(mb_find_next_zero_bit_test); 7214 7215int mb_find_next_bit_test(void *addr, int max, int start) 7216{ 7217 return mb_find_next_bit(addr, max, start); 7218} 7219EXPORT_SYMBOL_FOR_EXT4_TEST(mb_find_next_bit_test); 7220 7221void mb_clear_bit_test(int bit, void *addr) 7222{ 7223 mb_clear_bit(bit, addr); 7224} 7225EXPORT_SYMBOL_FOR_EXT4_TEST(mb_clear_bit_test); 7226 7227int mb_test_bit_test(int bit, void *addr) 7228{ 7229 return mb_test_bit(bit, addr); 7230} 7231EXPORT_SYMBOL_FOR_EXT4_TEST(mb_test_bit_test); 7232 7233int ext4_mb_mark_diskspace_used_test(struct ext4_allocation_context *ac, 7234 handle_t *handle) 7235{ 7236 return ext4_mb_mark_diskspace_used(ac, handle); 7237} 7238EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_mark_diskspace_used_test); 7239 7240int mb_mark_used_test(struct ext4_buddy *e4b, struct ext4_free_extent *ex) 7241{ 7242 return mb_mark_used(e4b, ex); 7243} 7244EXPORT_SYMBOL_FOR_EXT4_TEST(mb_mark_used_test); 7245 7246void ext4_mb_generate_buddy_test(struct super_block *sb, void *buddy, 7247 void *bitmap, ext4_group_t group, 7248 struct ext4_group_info *grp) 7249{ 7250 ext4_mb_generate_buddy(sb, buddy, bitmap, group, grp); 7251} 7252EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_generate_buddy_test); 7253 7254int ext4_mb_load_buddy_test(struct super_block *sb, ext4_group_t group, 7255 struct ext4_buddy *e4b) 7256{ 7257 return ext4_mb_load_buddy(sb, group, e4b); 7258} 7259EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_load_buddy_test); 7260 7261void ext4_mb_unload_buddy_test(struct ext4_buddy *e4b) 7262{ 7263 ext4_mb_unload_buddy(e4b); 7264} 7265EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_unload_buddy_test); 7266 7267void mb_free_blocks_test(struct inode *inode, struct ext4_buddy *e4b, 7268 int first, int count) 7269{ 7270 mb_free_blocks(inode, e4b, first, count); 7271} 7272EXPORT_SYMBOL_FOR_EXT4_TEST(mb_free_blocks_test); 7273 7274void ext4_free_blocks_simple_test(struct inode *inode, ext4_fsblk_t block, 7275 unsigned long count) 7276{ 7277 return ext4_free_blocks_simple(inode, block, count); 7278} 7279EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_free_blocks_simple_test); 7280 7281EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_wait_block_bitmap); 7282EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_init); 7283EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_get_group_desc); 7284EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_count_free_clusters); 7285EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_get_group_info); 7286EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_free_group_clusters_set); 7287EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_release); 7288EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_read_block_bitmap_nowait); 7289EXPORT_SYMBOL_FOR_EXT4_TEST(mb_set_bits); 7290EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_fc_init_inode); 7291EXPORT_SYMBOL_FOR_EXT4_TEST(ext4_mb_mark_context); 7292#endif
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