Alex Tomas | c9de560 | 2008-01-29 00:19:52 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com |
| 3 | * Written by Alex Tomas <alex@clusterfs.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public Licens |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| 17 | */ |
| 18 | |
| 19 | |
| 20 | /* |
| 21 | * mballoc.c contains the multiblocks allocation routines |
| 22 | */ |
| 23 | |
| 24 | #include <linux/time.h> |
| 25 | #include <linux/fs.h> |
| 26 | #include <linux/namei.h> |
| 27 | #include <linux/ext4_jbd2.h> |
| 28 | #include <linux/ext4_fs.h> |
| 29 | #include <linux/quotaops.h> |
| 30 | #include <linux/buffer_head.h> |
| 31 | #include <linux/module.h> |
| 32 | #include <linux/swap.h> |
| 33 | #include <linux/proc_fs.h> |
| 34 | #include <linux/pagemap.h> |
| 35 | #include <linux/seq_file.h> |
| 36 | #include <linux/version.h> |
| 37 | #include "group.h" |
| 38 | |
| 39 | /* |
| 40 | * MUSTDO: |
| 41 | * - test ext4_ext_search_left() and ext4_ext_search_right() |
| 42 | * - search for metadata in few groups |
| 43 | * |
| 44 | * TODO v4: |
| 45 | * - normalization should take into account whether file is still open |
| 46 | * - discard preallocations if no free space left (policy?) |
| 47 | * - don't normalize tails |
| 48 | * - quota |
| 49 | * - reservation for superuser |
| 50 | * |
| 51 | * TODO v3: |
| 52 | * - bitmap read-ahead (proposed by Oleg Drokin aka green) |
| 53 | * - track min/max extents in each group for better group selection |
| 54 | * - mb_mark_used() may allocate chunk right after splitting buddy |
| 55 | * - tree of groups sorted by number of free blocks |
| 56 | * - error handling |
| 57 | */ |
| 58 | |
| 59 | /* |
| 60 | * The allocation request involve request for multiple number of blocks |
| 61 | * near to the goal(block) value specified. |
| 62 | * |
| 63 | * During initialization phase of the allocator we decide to use the group |
| 64 | * preallocation or inode preallocation depending on the size file. The |
| 65 | * size of the file could be the resulting file size we would have after |
| 66 | * allocation or the current file size which ever is larger. If the size is |
| 67 | * less that sbi->s_mb_stream_request we select the group |
| 68 | * preallocation. The default value of s_mb_stream_request is 16 |
| 69 | * blocks. This can also be tuned via |
| 70 | * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms |
| 71 | * of number of blocks. |
| 72 | * |
| 73 | * The main motivation for having small file use group preallocation is to |
| 74 | * ensure that we have small file closer in the disk. |
| 75 | * |
| 76 | * First stage the allocator looks at the inode prealloc list |
| 77 | * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for |
| 78 | * this particular inode. The inode prealloc space is represented as: |
| 79 | * |
| 80 | * pa_lstart -> the logical start block for this prealloc space |
| 81 | * pa_pstart -> the physical start block for this prealloc space |
| 82 | * pa_len -> lenght for this prealloc space |
| 83 | * pa_free -> free space available in this prealloc space |
| 84 | * |
| 85 | * The inode preallocation space is used looking at the _logical_ start |
| 86 | * block. If only the logical file block falls within the range of prealloc |
| 87 | * space we will consume the particular prealloc space. This make sure that |
| 88 | * that the we have contiguous physical blocks representing the file blocks |
| 89 | * |
| 90 | * The important thing to be noted in case of inode prealloc space is that |
| 91 | * we don't modify the values associated to inode prealloc space except |
| 92 | * pa_free. |
| 93 | * |
| 94 | * If we are not able to find blocks in the inode prealloc space and if we |
| 95 | * have the group allocation flag set then we look at the locality group |
| 96 | * prealloc space. These are per CPU prealloc list repreasented as |
| 97 | * |
| 98 | * ext4_sb_info.s_locality_groups[smp_processor_id()] |
| 99 | * |
| 100 | * The reason for having a per cpu locality group is to reduce the contention |
| 101 | * between CPUs. It is possible to get scheduled at this point. |
| 102 | * |
| 103 | * The locality group prealloc space is used looking at whether we have |
| 104 | * enough free space (pa_free) withing the prealloc space. |
| 105 | * |
| 106 | * If we can't allocate blocks via inode prealloc or/and locality group |
| 107 | * prealloc then we look at the buddy cache. The buddy cache is represented |
| 108 | * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets |
| 109 | * mapped to the buddy and bitmap information regarding different |
| 110 | * groups. The buddy information is attached to buddy cache inode so that |
| 111 | * we can access them through the page cache. The information regarding |
| 112 | * each group is loaded via ext4_mb_load_buddy. The information involve |
| 113 | * block bitmap and buddy information. The information are stored in the |
| 114 | * inode as: |
| 115 | * |
| 116 | * { page } |
| 117 | * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]... |
| 118 | * |
| 119 | * |
| 120 | * one block each for bitmap and buddy information. So for each group we |
| 121 | * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE / |
| 122 | * blocksize) blocks. So it can have information regarding groups_per_page |
| 123 | * which is blocks_per_page/2 |
| 124 | * |
| 125 | * The buddy cache inode is not stored on disk. The inode is thrown |
| 126 | * away when the filesystem is unmounted. |
| 127 | * |
| 128 | * We look for count number of blocks in the buddy cache. If we were able |
| 129 | * to locate that many free blocks we return with additional information |
| 130 | * regarding rest of the contiguous physical block available |
| 131 | * |
| 132 | * Before allocating blocks via buddy cache we normalize the request |
| 133 | * blocks. This ensure we ask for more blocks that we needed. The extra |
| 134 | * blocks that we get after allocation is added to the respective prealloc |
| 135 | * list. In case of inode preallocation we follow a list of heuristics |
| 136 | * based on file size. This can be found in ext4_mb_normalize_request. If |
| 137 | * we are doing a group prealloc we try to normalize the request to |
| 138 | * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to |
| 139 | * 512 blocks. This can be tuned via |
| 140 | * /proc/fs/ext4/<partition/group_prealloc. The value is represented in |
| 141 | * terms of number of blocks. If we have mounted the file system with -O |
| 142 | * stripe=<value> option the group prealloc request is normalized to the |
| 143 | * stripe value (sbi->s_stripe) |
| 144 | * |
| 145 | * The regular allocator(using the buddy cache) support few tunables. |
| 146 | * |
| 147 | * /proc/fs/ext4/<partition>/min_to_scan |
| 148 | * /proc/fs/ext4/<partition>/max_to_scan |
| 149 | * /proc/fs/ext4/<partition>/order2_req |
| 150 | * |
| 151 | * The regular allocator use buddy scan only if the request len is power of |
| 152 | * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The |
| 153 | * value of s_mb_order2_reqs can be tuned via |
| 154 | * /proc/fs/ext4/<partition>/order2_req. If the request len is equal to |
| 155 | * stripe size (sbi->s_stripe), we try to search for contigous block in |
| 156 | * stripe size. This should result in better allocation on RAID setup. If |
| 157 | * not we search in the specific group using bitmap for best extents. The |
| 158 | * tunable min_to_scan and max_to_scan controll the behaviour here. |
| 159 | * min_to_scan indicate how long the mballoc __must__ look for a best |
| 160 | * extent and max_to_scanindicate how long the mballoc __can__ look for a |
| 161 | * best extent in the found extents. Searching for the blocks starts with |
| 162 | * the group specified as the goal value in allocation context via |
| 163 | * ac_g_ex. Each group is first checked based on the criteria whether it |
| 164 | * can used for allocation. ext4_mb_good_group explains how the groups are |
| 165 | * checked. |
| 166 | * |
| 167 | * Both the prealloc space are getting populated as above. So for the first |
| 168 | * request we will hit the buddy cache which will result in this prealloc |
| 169 | * space getting filled. The prealloc space is then later used for the |
| 170 | * subsequent request. |
| 171 | */ |
| 172 | |
| 173 | /* |
| 174 | * mballoc operates on the following data: |
| 175 | * - on-disk bitmap |
| 176 | * - in-core buddy (actually includes buddy and bitmap) |
| 177 | * - preallocation descriptors (PAs) |
| 178 | * |
| 179 | * there are two types of preallocations: |
| 180 | * - inode |
| 181 | * assiged to specific inode and can be used for this inode only. |
| 182 | * it describes part of inode's space preallocated to specific |
| 183 | * physical blocks. any block from that preallocated can be used |
| 184 | * independent. the descriptor just tracks number of blocks left |
| 185 | * unused. so, before taking some block from descriptor, one must |
| 186 | * make sure corresponded logical block isn't allocated yet. this |
| 187 | * also means that freeing any block within descriptor's range |
| 188 | * must discard all preallocated blocks. |
| 189 | * - locality group |
| 190 | * assigned to specific locality group which does not translate to |
| 191 | * permanent set of inodes: inode can join and leave group. space |
| 192 | * from this type of preallocation can be used for any inode. thus |
| 193 | * it's consumed from the beginning to the end. |
| 194 | * |
| 195 | * relation between them can be expressed as: |
| 196 | * in-core buddy = on-disk bitmap + preallocation descriptors |
| 197 | * |
| 198 | * this mean blocks mballoc considers used are: |
| 199 | * - allocated blocks (persistent) |
| 200 | * - preallocated blocks (non-persistent) |
| 201 | * |
| 202 | * consistency in mballoc world means that at any time a block is either |
| 203 | * free or used in ALL structures. notice: "any time" should not be read |
| 204 | * literally -- time is discrete and delimited by locks. |
| 205 | * |
| 206 | * to keep it simple, we don't use block numbers, instead we count number of |
| 207 | * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA. |
| 208 | * |
| 209 | * all operations can be expressed as: |
| 210 | * - init buddy: buddy = on-disk + PAs |
| 211 | * - new PA: buddy += N; PA = N |
| 212 | * - use inode PA: on-disk += N; PA -= N |
| 213 | * - discard inode PA buddy -= on-disk - PA; PA = 0 |
| 214 | * - use locality group PA on-disk += N; PA -= N |
| 215 | * - discard locality group PA buddy -= PA; PA = 0 |
| 216 | * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap |
| 217 | * is used in real operation because we can't know actual used |
| 218 | * bits from PA, only from on-disk bitmap |
| 219 | * |
| 220 | * if we follow this strict logic, then all operations above should be atomic. |
| 221 | * given some of them can block, we'd have to use something like semaphores |
| 222 | * killing performance on high-end SMP hardware. let's try to relax it using |
| 223 | * the following knowledge: |
| 224 | * 1) if buddy is referenced, it's already initialized |
| 225 | * 2) while block is used in buddy and the buddy is referenced, |
| 226 | * nobody can re-allocate that block |
| 227 | * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has |
| 228 | * bit set and PA claims same block, it's OK. IOW, one can set bit in |
| 229 | * on-disk bitmap if buddy has same bit set or/and PA covers corresponded |
| 230 | * block |
| 231 | * |
| 232 | * so, now we're building a concurrency table: |
| 233 | * - init buddy vs. |
| 234 | * - new PA |
| 235 | * blocks for PA are allocated in the buddy, buddy must be referenced |
| 236 | * until PA is linked to allocation group to avoid concurrent buddy init |
| 237 | * - use inode PA |
| 238 | * we need to make sure that either on-disk bitmap or PA has uptodate data |
| 239 | * given (3) we care that PA-=N operation doesn't interfere with init |
| 240 | * - discard inode PA |
| 241 | * the simplest way would be to have buddy initialized by the discard |
| 242 | * - use locality group PA |
| 243 | * again PA-=N must be serialized with init |
| 244 | * - discard locality group PA |
| 245 | * the simplest way would be to have buddy initialized by the discard |
| 246 | * - new PA vs. |
| 247 | * - use inode PA |
| 248 | * i_data_sem serializes them |
| 249 | * - discard inode PA |
| 250 | * discard process must wait until PA isn't used by another process |
| 251 | * - use locality group PA |
| 252 | * some mutex should serialize them |
| 253 | * - discard locality group PA |
| 254 | * discard process must wait until PA isn't used by another process |
| 255 | * - use inode PA |
| 256 | * - use inode PA |
| 257 | * i_data_sem or another mutex should serializes them |
| 258 | * - discard inode PA |
| 259 | * discard process must wait until PA isn't used by another process |
| 260 | * - use locality group PA |
| 261 | * nothing wrong here -- they're different PAs covering different blocks |
| 262 | * - discard locality group PA |
| 263 | * discard process must wait until PA isn't used by another process |
| 264 | * |
| 265 | * now we're ready to make few consequences: |
| 266 | * - PA is referenced and while it is no discard is possible |
| 267 | * - PA is referenced until block isn't marked in on-disk bitmap |
| 268 | * - PA changes only after on-disk bitmap |
| 269 | * - discard must not compete with init. either init is done before |
| 270 | * any discard or they're serialized somehow |
| 271 | * - buddy init as sum of on-disk bitmap and PAs is done atomically |
| 272 | * |
| 273 | * a special case when we've used PA to emptiness. no need to modify buddy |
| 274 | * in this case, but we should care about concurrent init |
| 275 | * |
| 276 | */ |
| 277 | |
| 278 | /* |
| 279 | * Logic in few words: |
| 280 | * |
| 281 | * - allocation: |
| 282 | * load group |
| 283 | * find blocks |
| 284 | * mark bits in on-disk bitmap |
| 285 | * release group |
| 286 | * |
| 287 | * - use preallocation: |
| 288 | * find proper PA (per-inode or group) |
| 289 | * load group |
| 290 | * mark bits in on-disk bitmap |
| 291 | * release group |
| 292 | * release PA |
| 293 | * |
| 294 | * - free: |
| 295 | * load group |
| 296 | * mark bits in on-disk bitmap |
| 297 | * release group |
| 298 | * |
| 299 | * - discard preallocations in group: |
| 300 | * mark PAs deleted |
| 301 | * move them onto local list |
| 302 | * load on-disk bitmap |
| 303 | * load group |
| 304 | * remove PA from object (inode or locality group) |
| 305 | * mark free blocks in-core |
| 306 | * |
| 307 | * - discard inode's preallocations: |
| 308 | */ |
| 309 | |
| 310 | /* |
| 311 | * Locking rules |
| 312 | * |
| 313 | * Locks: |
| 314 | * - bitlock on a group (group) |
| 315 | * - object (inode/locality) (object) |
| 316 | * - per-pa lock (pa) |
| 317 | * |
| 318 | * Paths: |
| 319 | * - new pa |
| 320 | * object |
| 321 | * group |
| 322 | * |
| 323 | * - find and use pa: |
| 324 | * pa |
| 325 | * |
| 326 | * - release consumed pa: |
| 327 | * pa |
| 328 | * group |
| 329 | * object |
| 330 | * |
| 331 | * - generate in-core bitmap: |
| 332 | * group |
| 333 | * pa |
| 334 | * |
| 335 | * - discard all for given object (inode, locality group): |
| 336 | * object |
| 337 | * pa |
| 338 | * group |
| 339 | * |
| 340 | * - discard all for given group: |
| 341 | * group |
| 342 | * pa |
| 343 | * group |
| 344 | * object |
| 345 | * |
| 346 | */ |
| 347 | |
| 348 | /* |
| 349 | * with AGGRESSIVE_CHECK allocator runs consistency checks over |
| 350 | * structures. these checks slow things down a lot |
| 351 | */ |
| 352 | #define AGGRESSIVE_CHECK__ |
| 353 | |
| 354 | /* |
| 355 | * with DOUBLE_CHECK defined mballoc creates persistent in-core |
| 356 | * bitmaps, maintains and uses them to check for double allocations |
| 357 | */ |
| 358 | #define DOUBLE_CHECK__ |
| 359 | |
| 360 | /* |
| 361 | */ |
| 362 | #define MB_DEBUG__ |
| 363 | #ifdef MB_DEBUG |
| 364 | #define mb_debug(fmt, a...) printk(fmt, ##a) |
| 365 | #else |
| 366 | #define mb_debug(fmt, a...) |
| 367 | #endif |
| 368 | |
| 369 | /* |
| 370 | * with EXT4_MB_HISTORY mballoc stores last N allocations in memory |
| 371 | * and you can monitor it in /proc/fs/ext4/<dev>/mb_history |
| 372 | */ |
| 373 | #define EXT4_MB_HISTORY |
| 374 | #define EXT4_MB_HISTORY_ALLOC 1 /* allocation */ |
| 375 | #define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */ |
| 376 | #define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */ |
| 377 | #define EXT4_MB_HISTORY_FREE 8 /* free */ |
| 378 | |
| 379 | #define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \ |
| 380 | EXT4_MB_HISTORY_PREALLOC) |
| 381 | |
| 382 | /* |
| 383 | * How long mballoc can look for a best extent (in found extents) |
| 384 | */ |
| 385 | #define MB_DEFAULT_MAX_TO_SCAN 200 |
| 386 | |
| 387 | /* |
| 388 | * How long mballoc must look for a best extent |
| 389 | */ |
| 390 | #define MB_DEFAULT_MIN_TO_SCAN 10 |
| 391 | |
| 392 | /* |
| 393 | * How many groups mballoc will scan looking for the best chunk |
| 394 | */ |
| 395 | #define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5 |
| 396 | |
| 397 | /* |
| 398 | * with 'ext4_mb_stats' allocator will collect stats that will be |
| 399 | * shown at umount. The collecting costs though! |
| 400 | */ |
| 401 | #define MB_DEFAULT_STATS 1 |
| 402 | |
| 403 | /* |
| 404 | * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served |
| 405 | * by the stream allocator, which purpose is to pack requests |
| 406 | * as close each to other as possible to produce smooth I/O traffic |
| 407 | * We use locality group prealloc space for stream request. |
| 408 | * We can tune the same via /proc/fs/ext4/<parition>/stream_req |
| 409 | */ |
| 410 | #define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */ |
| 411 | |
| 412 | /* |
| 413 | * for which requests use 2^N search using buddies |
| 414 | */ |
| 415 | #define MB_DEFAULT_ORDER2_REQS 2 |
| 416 | |
| 417 | /* |
| 418 | * default group prealloc size 512 blocks |
| 419 | */ |
| 420 | #define MB_DEFAULT_GROUP_PREALLOC 512 |
| 421 | |
| 422 | static struct kmem_cache *ext4_pspace_cachep; |
| 423 | |
| 424 | #ifdef EXT4_BB_MAX_BLOCKS |
| 425 | #undef EXT4_BB_MAX_BLOCKS |
| 426 | #endif |
| 427 | #define EXT4_BB_MAX_BLOCKS 30 |
| 428 | |
| 429 | struct ext4_free_metadata { |
| 430 | ext4_group_t group; |
| 431 | unsigned short num; |
| 432 | ext4_grpblk_t blocks[EXT4_BB_MAX_BLOCKS]; |
| 433 | struct list_head list; |
| 434 | }; |
| 435 | |
| 436 | struct ext4_group_info { |
| 437 | unsigned long bb_state; |
| 438 | unsigned long bb_tid; |
| 439 | struct ext4_free_metadata *bb_md_cur; |
| 440 | unsigned short bb_first_free; |
| 441 | unsigned short bb_free; |
| 442 | unsigned short bb_fragments; |
| 443 | struct list_head bb_prealloc_list; |
| 444 | #ifdef DOUBLE_CHECK |
| 445 | void *bb_bitmap; |
| 446 | #endif |
| 447 | unsigned short bb_counters[]; |
| 448 | }; |
| 449 | |
| 450 | #define EXT4_GROUP_INFO_NEED_INIT_BIT 0 |
| 451 | #define EXT4_GROUP_INFO_LOCKED_BIT 1 |
| 452 | |
| 453 | #define EXT4_MB_GRP_NEED_INIT(grp) \ |
| 454 | (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state))) |
| 455 | |
| 456 | |
| 457 | struct ext4_prealloc_space { |
| 458 | struct list_head pa_inode_list; |
| 459 | struct list_head pa_group_list; |
| 460 | union { |
| 461 | struct list_head pa_tmp_list; |
| 462 | struct rcu_head pa_rcu; |
| 463 | } u; |
| 464 | spinlock_t pa_lock; |
| 465 | atomic_t pa_count; |
| 466 | unsigned pa_deleted; |
| 467 | ext4_fsblk_t pa_pstart; /* phys. block */ |
| 468 | ext4_lblk_t pa_lstart; /* log. block */ |
| 469 | unsigned short pa_len; /* len of preallocated chunk */ |
| 470 | unsigned short pa_free; /* how many blocks are free */ |
| 471 | unsigned short pa_linear; /* consumed in one direction |
| 472 | * strictly, for grp prealloc */ |
| 473 | spinlock_t *pa_obj_lock; |
| 474 | struct inode *pa_inode; /* hack, for history only */ |
| 475 | }; |
| 476 | |
| 477 | |
| 478 | struct ext4_free_extent { |
| 479 | ext4_lblk_t fe_logical; |
| 480 | ext4_grpblk_t fe_start; |
| 481 | ext4_group_t fe_group; |
| 482 | int fe_len; |
| 483 | }; |
| 484 | |
| 485 | /* |
| 486 | * Locality group: |
| 487 | * we try to group all related changes together |
| 488 | * so that writeback can flush/allocate them together as well |
| 489 | */ |
| 490 | struct ext4_locality_group { |
| 491 | /* for allocator */ |
| 492 | struct mutex lg_mutex; /* to serialize allocates */ |
| 493 | struct list_head lg_prealloc_list;/* list of preallocations */ |
| 494 | spinlock_t lg_prealloc_lock; |
| 495 | }; |
| 496 | |
| 497 | struct ext4_allocation_context { |
| 498 | struct inode *ac_inode; |
| 499 | struct super_block *ac_sb; |
| 500 | |
| 501 | /* original request */ |
| 502 | struct ext4_free_extent ac_o_ex; |
| 503 | |
| 504 | /* goal request (after normalization) */ |
| 505 | struct ext4_free_extent ac_g_ex; |
| 506 | |
| 507 | /* the best found extent */ |
| 508 | struct ext4_free_extent ac_b_ex; |
| 509 | |
| 510 | /* copy of the bext found extent taken before preallocation efforts */ |
| 511 | struct ext4_free_extent ac_f_ex; |
| 512 | |
| 513 | /* number of iterations done. we have to track to limit searching */ |
| 514 | unsigned long ac_ex_scanned; |
| 515 | __u16 ac_groups_scanned; |
| 516 | __u16 ac_found; |
| 517 | __u16 ac_tail; |
| 518 | __u16 ac_buddy; |
| 519 | __u16 ac_flags; /* allocation hints */ |
| 520 | __u8 ac_status; |
| 521 | __u8 ac_criteria; |
| 522 | __u8 ac_repeats; |
| 523 | __u8 ac_2order; /* if request is to allocate 2^N blocks and |
| 524 | * N > 0, the field stores N, otherwise 0 */ |
| 525 | __u8 ac_op; /* operation, for history only */ |
| 526 | struct page *ac_bitmap_page; |
| 527 | struct page *ac_buddy_page; |
| 528 | struct ext4_prealloc_space *ac_pa; |
| 529 | struct ext4_locality_group *ac_lg; |
| 530 | }; |
| 531 | |
| 532 | #define AC_STATUS_CONTINUE 1 |
| 533 | #define AC_STATUS_FOUND 2 |
| 534 | #define AC_STATUS_BREAK 3 |
| 535 | |
| 536 | struct ext4_mb_history { |
| 537 | struct ext4_free_extent orig; /* orig allocation */ |
| 538 | struct ext4_free_extent goal; /* goal allocation */ |
| 539 | struct ext4_free_extent result; /* result allocation */ |
| 540 | unsigned pid; |
| 541 | unsigned ino; |
| 542 | __u16 found; /* how many extents have been found */ |
| 543 | __u16 groups; /* how many groups have been scanned */ |
| 544 | __u16 tail; /* what tail broke some buddy */ |
| 545 | __u16 buddy; /* buddy the tail ^^^ broke */ |
| 546 | __u16 flags; |
| 547 | __u8 cr:3; /* which phase the result extent was found at */ |
| 548 | __u8 op:4; |
| 549 | __u8 merged:1; |
| 550 | }; |
| 551 | |
| 552 | struct ext4_buddy { |
| 553 | struct page *bd_buddy_page; |
| 554 | void *bd_buddy; |
| 555 | struct page *bd_bitmap_page; |
| 556 | void *bd_bitmap; |
| 557 | struct ext4_group_info *bd_info; |
| 558 | struct super_block *bd_sb; |
| 559 | __u16 bd_blkbits; |
| 560 | ext4_group_t bd_group; |
| 561 | }; |
| 562 | #define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap) |
| 563 | #define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy) |
| 564 | |
| 565 | #ifndef EXT4_MB_HISTORY |
| 566 | static inline void ext4_mb_store_history(struct ext4_allocation_context *ac) |
| 567 | { |
| 568 | return; |
| 569 | } |
| 570 | #else |
| 571 | static void ext4_mb_store_history(struct ext4_allocation_context *ac); |
| 572 | #endif |
| 573 | |
| 574 | #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) |
| 575 | |
| 576 | static struct proc_dir_entry *proc_root_ext4; |
| 577 | struct buffer_head *read_block_bitmap(struct super_block *, ext4_group_t); |
| 578 | ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode, |
| 579 | ext4_fsblk_t goal, unsigned long *count, int *errp); |
| 580 | |
| 581 | static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, |
| 582 | ext4_group_t group); |
| 583 | static void ext4_mb_poll_new_transaction(struct super_block *, handle_t *); |
| 584 | static void ext4_mb_free_committed_blocks(struct super_block *); |
| 585 | static void ext4_mb_return_to_preallocation(struct inode *inode, |
| 586 | struct ext4_buddy *e4b, sector_t block, |
| 587 | int count); |
| 588 | static void ext4_mb_put_pa(struct ext4_allocation_context *, |
| 589 | struct super_block *, struct ext4_prealloc_space *pa); |
| 590 | static int ext4_mb_init_per_dev_proc(struct super_block *sb); |
| 591 | static int ext4_mb_destroy_per_dev_proc(struct super_block *sb); |
| 592 | |
| 593 | |
| 594 | static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group) |
| 595 | { |
| 596 | struct ext4_group_info *grinfo = ext4_get_group_info(sb, group); |
| 597 | |
| 598 | bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state)); |
| 599 | } |
| 600 | |
| 601 | static inline void ext4_unlock_group(struct super_block *sb, |
| 602 | ext4_group_t group) |
| 603 | { |
| 604 | struct ext4_group_info *grinfo = ext4_get_group_info(sb, group); |
| 605 | |
| 606 | bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state)); |
| 607 | } |
| 608 | |
| 609 | static inline int ext4_is_group_locked(struct super_block *sb, |
| 610 | ext4_group_t group) |
| 611 | { |
| 612 | struct ext4_group_info *grinfo = ext4_get_group_info(sb, group); |
| 613 | |
| 614 | return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT, |
| 615 | &(grinfo->bb_state)); |
| 616 | } |
| 617 | |
| 618 | static ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, |
| 619 | struct ext4_free_extent *fex) |
| 620 | { |
| 621 | ext4_fsblk_t block; |
| 622 | |
| 623 | block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb) |
| 624 | + fex->fe_start |
| 625 | + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); |
| 626 | return block; |
| 627 | } |
| 628 | |
| 629 | #if BITS_PER_LONG == 64 |
| 630 | #define mb_correct_addr_and_bit(bit, addr) \ |
| 631 | { \ |
| 632 | bit += ((unsigned long) addr & 7UL) << 3; \ |
| 633 | addr = (void *) ((unsigned long) addr & ~7UL); \ |
| 634 | } |
| 635 | #elif BITS_PER_LONG == 32 |
| 636 | #define mb_correct_addr_and_bit(bit, addr) \ |
| 637 | { \ |
| 638 | bit += ((unsigned long) addr & 3UL) << 3; \ |
| 639 | addr = (void *) ((unsigned long) addr & ~3UL); \ |
| 640 | } |
| 641 | #else |
| 642 | #error "how many bits you are?!" |
| 643 | #endif |
| 644 | |
| 645 | static inline int mb_test_bit(int bit, void *addr) |
| 646 | { |
| 647 | /* |
| 648 | * ext4_test_bit on architecture like powerpc |
| 649 | * needs unsigned long aligned address |
| 650 | */ |
| 651 | mb_correct_addr_and_bit(bit, addr); |
| 652 | return ext4_test_bit(bit, addr); |
| 653 | } |
| 654 | |
| 655 | static inline void mb_set_bit(int bit, void *addr) |
| 656 | { |
| 657 | mb_correct_addr_and_bit(bit, addr); |
| 658 | ext4_set_bit(bit, addr); |
| 659 | } |
| 660 | |
| 661 | static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr) |
| 662 | { |
| 663 | mb_correct_addr_and_bit(bit, addr); |
| 664 | ext4_set_bit_atomic(lock, bit, addr); |
| 665 | } |
| 666 | |
| 667 | static inline void mb_clear_bit(int bit, void *addr) |
| 668 | { |
| 669 | mb_correct_addr_and_bit(bit, addr); |
| 670 | ext4_clear_bit(bit, addr); |
| 671 | } |
| 672 | |
| 673 | static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr) |
| 674 | { |
| 675 | mb_correct_addr_and_bit(bit, addr); |
| 676 | ext4_clear_bit_atomic(lock, bit, addr); |
| 677 | } |
| 678 | |
| 679 | static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max) |
| 680 | { |
| 681 | char *bb; |
| 682 | |
| 683 | /* FIXME!! is this needed */ |
| 684 | BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b)); |
| 685 | BUG_ON(max == NULL); |
| 686 | |
| 687 | if (order > e4b->bd_blkbits + 1) { |
| 688 | *max = 0; |
| 689 | return NULL; |
| 690 | } |
| 691 | |
| 692 | /* at order 0 we see each particular block */ |
| 693 | *max = 1 << (e4b->bd_blkbits + 3); |
| 694 | if (order == 0) |
| 695 | return EXT4_MB_BITMAP(e4b); |
| 696 | |
| 697 | bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order]; |
| 698 | *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order]; |
| 699 | |
| 700 | return bb; |
| 701 | } |
| 702 | |
| 703 | #ifdef DOUBLE_CHECK |
| 704 | static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b, |
| 705 | int first, int count) |
| 706 | { |
| 707 | int i; |
| 708 | struct super_block *sb = e4b->bd_sb; |
| 709 | |
| 710 | if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
| 711 | return; |
| 712 | BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group)); |
| 713 | for (i = 0; i < count; i++) { |
| 714 | if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) { |
| 715 | ext4_fsblk_t blocknr; |
| 716 | blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb); |
| 717 | blocknr += first + i; |
| 718 | blocknr += |
| 719 | le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); |
| 720 | |
| 721 | ext4_error(sb, __FUNCTION__, "double-free of inode" |
| 722 | " %lu's block %llu(bit %u in group %lu)\n", |
| 723 | inode ? inode->i_ino : 0, blocknr, |
| 724 | first + i, e4b->bd_group); |
| 725 | } |
| 726 | mb_clear_bit(first + i, e4b->bd_info->bb_bitmap); |
| 727 | } |
| 728 | } |
| 729 | |
| 730 | static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count) |
| 731 | { |
| 732 | int i; |
| 733 | |
| 734 | if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
| 735 | return; |
| 736 | BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); |
| 737 | for (i = 0; i < count; i++) { |
| 738 | BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap)); |
| 739 | mb_set_bit(first + i, e4b->bd_info->bb_bitmap); |
| 740 | } |
| 741 | } |
| 742 | |
| 743 | static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
| 744 | { |
| 745 | if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) { |
| 746 | unsigned char *b1, *b2; |
| 747 | int i; |
| 748 | b1 = (unsigned char *) e4b->bd_info->bb_bitmap; |
| 749 | b2 = (unsigned char *) bitmap; |
| 750 | for (i = 0; i < e4b->bd_sb->s_blocksize; i++) { |
| 751 | if (b1[i] != b2[i]) { |
| 752 | printk("corruption in group %lu at byte %u(%u):" |
| 753 | " %x in copy != %x on disk/prealloc\n", |
| 754 | e4b->bd_group, i, i * 8, b1[i], b2[i]); |
| 755 | BUG(); |
| 756 | } |
| 757 | } |
| 758 | } |
| 759 | } |
| 760 | |
| 761 | #else |
| 762 | static inline void mb_free_blocks_double(struct inode *inode, |
| 763 | struct ext4_buddy *e4b, int first, int count) |
| 764 | { |
| 765 | return; |
| 766 | } |
| 767 | static inline void mb_mark_used_double(struct ext4_buddy *e4b, |
| 768 | int first, int count) |
| 769 | { |
| 770 | return; |
| 771 | } |
| 772 | static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
| 773 | { |
| 774 | return; |
| 775 | } |
| 776 | #endif |
| 777 | |
| 778 | #ifdef AGGRESSIVE_CHECK |
| 779 | |
| 780 | #define MB_CHECK_ASSERT(assert) \ |
| 781 | do { \ |
| 782 | if (!(assert)) { \ |
| 783 | printk(KERN_EMERG \ |
| 784 | "Assertion failure in %s() at %s:%d: \"%s\"\n", \ |
| 785 | function, file, line, # assert); \ |
| 786 | BUG(); \ |
| 787 | } \ |
| 788 | } while (0) |
| 789 | |
| 790 | static int __mb_check_buddy(struct ext4_buddy *e4b, char *file, |
| 791 | const char *function, int line) |
| 792 | { |
| 793 | struct super_block *sb = e4b->bd_sb; |
| 794 | int order = e4b->bd_blkbits + 1; |
| 795 | int max; |
| 796 | int max2; |
| 797 | int i; |
| 798 | int j; |
| 799 | int k; |
| 800 | int count; |
| 801 | struct ext4_group_info *grp; |
| 802 | int fragments = 0; |
| 803 | int fstart; |
| 804 | struct list_head *cur; |
| 805 | void *buddy; |
| 806 | void *buddy2; |
| 807 | |
| 808 | if (!test_opt(sb, MBALLOC)) |
| 809 | return 0; |
| 810 | |
| 811 | { |
| 812 | static int mb_check_counter; |
| 813 | if (mb_check_counter++ % 100 != 0) |
| 814 | return 0; |
| 815 | } |
| 816 | |
| 817 | while (order > 1) { |
| 818 | buddy = mb_find_buddy(e4b, order, &max); |
| 819 | MB_CHECK_ASSERT(buddy); |
| 820 | buddy2 = mb_find_buddy(e4b, order - 1, &max2); |
| 821 | MB_CHECK_ASSERT(buddy2); |
| 822 | MB_CHECK_ASSERT(buddy != buddy2); |
| 823 | MB_CHECK_ASSERT(max * 2 == max2); |
| 824 | |
| 825 | count = 0; |
| 826 | for (i = 0; i < max; i++) { |
| 827 | |
| 828 | if (mb_test_bit(i, buddy)) { |
| 829 | /* only single bit in buddy2 may be 1 */ |
| 830 | if (!mb_test_bit(i << 1, buddy2)) { |
| 831 | MB_CHECK_ASSERT( |
| 832 | mb_test_bit((i<<1)+1, buddy2)); |
| 833 | } else if (!mb_test_bit((i << 1) + 1, buddy2)) { |
| 834 | MB_CHECK_ASSERT( |
| 835 | mb_test_bit(i << 1, buddy2)); |
| 836 | } |
| 837 | continue; |
| 838 | } |
| 839 | |
| 840 | /* both bits in buddy2 must be 0 */ |
| 841 | MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2)); |
| 842 | MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2)); |
| 843 | |
| 844 | for (j = 0; j < (1 << order); j++) { |
| 845 | k = (i * (1 << order)) + j; |
| 846 | MB_CHECK_ASSERT( |
| 847 | !mb_test_bit(k, EXT4_MB_BITMAP(e4b))); |
| 848 | } |
| 849 | count++; |
| 850 | } |
| 851 | MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count); |
| 852 | order--; |
| 853 | } |
| 854 | |
| 855 | fstart = -1; |
| 856 | buddy = mb_find_buddy(e4b, 0, &max); |
| 857 | for (i = 0; i < max; i++) { |
| 858 | if (!mb_test_bit(i, buddy)) { |
| 859 | MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); |
| 860 | if (fstart == -1) { |
| 861 | fragments++; |
| 862 | fstart = i; |
| 863 | } |
| 864 | continue; |
| 865 | } |
| 866 | fstart = -1; |
| 867 | /* check used bits only */ |
| 868 | for (j = 0; j < e4b->bd_blkbits + 1; j++) { |
| 869 | buddy2 = mb_find_buddy(e4b, j, &max2); |
| 870 | k = i >> j; |
| 871 | MB_CHECK_ASSERT(k < max2); |
| 872 | MB_CHECK_ASSERT(mb_test_bit(k, buddy2)); |
| 873 | } |
| 874 | } |
| 875 | MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); |
| 876 | MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); |
| 877 | |
| 878 | grp = ext4_get_group_info(sb, e4b->bd_group); |
| 879 | buddy = mb_find_buddy(e4b, 0, &max); |
| 880 | list_for_each(cur, &grp->bb_prealloc_list) { |
| 881 | ext4_group_t groupnr; |
| 882 | struct ext4_prealloc_space *pa; |
| 883 | pa = list_entry(cur, struct ext4_prealloc_space, group_list); |
| 884 | ext4_get_group_no_and_offset(sb, pa->pstart, &groupnr, &k); |
| 885 | MB_CHECK_ASSERT(groupnr == e4b->bd_group); |
| 886 | for (i = 0; i < pa->len; i++) |
| 887 | MB_CHECK_ASSERT(mb_test_bit(k + i, buddy)); |
| 888 | } |
| 889 | return 0; |
| 890 | } |
| 891 | #undef MB_CHECK_ASSERT |
| 892 | #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \ |
| 893 | __FILE__, __FUNCTION__, __LINE__) |
| 894 | #else |
| 895 | #define mb_check_buddy(e4b) |
| 896 | #endif |
| 897 | |
| 898 | /* FIXME!! need more doc */ |
| 899 | static void ext4_mb_mark_free_simple(struct super_block *sb, |
| 900 | void *buddy, unsigned first, int len, |
| 901 | struct ext4_group_info *grp) |
| 902 | { |
| 903 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 904 | unsigned short min; |
| 905 | unsigned short max; |
| 906 | unsigned short chunk; |
| 907 | unsigned short border; |
| 908 | |
| 909 | BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb)); |
| 910 | |
| 911 | border = 2 << sb->s_blocksize_bits; |
| 912 | |
| 913 | while (len > 0) { |
| 914 | /* find how many blocks can be covered since this position */ |
| 915 | max = ffs(first | border) - 1; |
| 916 | |
| 917 | /* find how many blocks of power 2 we need to mark */ |
| 918 | min = fls(len) - 1; |
| 919 | |
| 920 | if (max < min) |
| 921 | min = max; |
| 922 | chunk = 1 << min; |
| 923 | |
| 924 | /* mark multiblock chunks only */ |
| 925 | grp->bb_counters[min]++; |
| 926 | if (min > 0) |
| 927 | mb_clear_bit(first >> min, |
| 928 | buddy + sbi->s_mb_offsets[min]); |
| 929 | |
| 930 | len -= chunk; |
| 931 | first += chunk; |
| 932 | } |
| 933 | } |
| 934 | |
| 935 | static void ext4_mb_generate_buddy(struct super_block *sb, |
| 936 | void *buddy, void *bitmap, ext4_group_t group) |
| 937 | { |
| 938 | struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| 939 | unsigned short max = EXT4_BLOCKS_PER_GROUP(sb); |
| 940 | unsigned short i = 0; |
| 941 | unsigned short first; |
| 942 | unsigned short len; |
| 943 | unsigned free = 0; |
| 944 | unsigned fragments = 0; |
| 945 | unsigned long long period = get_cycles(); |
| 946 | |
| 947 | /* initialize buddy from bitmap which is aggregation |
| 948 | * of on-disk bitmap and preallocations */ |
| 949 | i = ext4_find_next_zero_bit(bitmap, max, 0); |
| 950 | grp->bb_first_free = i; |
| 951 | while (i < max) { |
| 952 | fragments++; |
| 953 | first = i; |
| 954 | i = ext4_find_next_bit(bitmap, max, i); |
| 955 | len = i - first; |
| 956 | free += len; |
| 957 | if (len > 1) |
| 958 | ext4_mb_mark_free_simple(sb, buddy, first, len, grp); |
| 959 | else |
| 960 | grp->bb_counters[0]++; |
| 961 | if (i < max) |
| 962 | i = ext4_find_next_zero_bit(bitmap, max, i); |
| 963 | } |
| 964 | grp->bb_fragments = fragments; |
| 965 | |
| 966 | if (free != grp->bb_free) { |
| 967 | printk(KERN_DEBUG |
| 968 | "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n", |
| 969 | group, free, grp->bb_free); |
| 970 | grp->bb_free = free; |
| 971 | } |
| 972 | |
| 973 | clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); |
| 974 | |
| 975 | period = get_cycles() - period; |
| 976 | spin_lock(&EXT4_SB(sb)->s_bal_lock); |
| 977 | EXT4_SB(sb)->s_mb_buddies_generated++; |
| 978 | EXT4_SB(sb)->s_mb_generation_time += period; |
| 979 | spin_unlock(&EXT4_SB(sb)->s_bal_lock); |
| 980 | } |
| 981 | |
| 982 | /* The buddy information is attached the buddy cache inode |
| 983 | * for convenience. The information regarding each group |
| 984 | * is loaded via ext4_mb_load_buddy. The information involve |
| 985 | * block bitmap and buddy information. The information are |
| 986 | * stored in the inode as |
| 987 | * |
| 988 | * { page } |
| 989 | * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]... |
| 990 | * |
| 991 | * |
| 992 | * one block each for bitmap and buddy information. |
| 993 | * So for each group we take up 2 blocks. A page can |
| 994 | * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks. |
| 995 | * So it can have information regarding groups_per_page which |
| 996 | * is blocks_per_page/2 |
| 997 | */ |
| 998 | |
| 999 | static int ext4_mb_init_cache(struct page *page, char *incore) |
| 1000 | { |
| 1001 | int blocksize; |
| 1002 | int blocks_per_page; |
| 1003 | int groups_per_page; |
| 1004 | int err = 0; |
| 1005 | int i; |
| 1006 | ext4_group_t first_group; |
| 1007 | int first_block; |
| 1008 | struct super_block *sb; |
| 1009 | struct buffer_head *bhs; |
| 1010 | struct buffer_head **bh; |
| 1011 | struct inode *inode; |
| 1012 | char *data; |
| 1013 | char *bitmap; |
| 1014 | |
| 1015 | mb_debug("init page %lu\n", page->index); |
| 1016 | |
| 1017 | inode = page->mapping->host; |
| 1018 | sb = inode->i_sb; |
| 1019 | blocksize = 1 << inode->i_blkbits; |
| 1020 | blocks_per_page = PAGE_CACHE_SIZE / blocksize; |
| 1021 | |
| 1022 | groups_per_page = blocks_per_page >> 1; |
| 1023 | if (groups_per_page == 0) |
| 1024 | groups_per_page = 1; |
| 1025 | |
| 1026 | /* allocate buffer_heads to read bitmaps */ |
| 1027 | if (groups_per_page > 1) { |
| 1028 | err = -ENOMEM; |
| 1029 | i = sizeof(struct buffer_head *) * groups_per_page; |
| 1030 | bh = kzalloc(i, GFP_NOFS); |
| 1031 | if (bh == NULL) |
| 1032 | goto out; |
| 1033 | } else |
| 1034 | bh = &bhs; |
| 1035 | |
| 1036 | first_group = page->index * blocks_per_page / 2; |
| 1037 | |
| 1038 | /* read all groups the page covers into the cache */ |
| 1039 | for (i = 0; i < groups_per_page; i++) { |
| 1040 | struct ext4_group_desc *desc; |
| 1041 | |
| 1042 | if (first_group + i >= EXT4_SB(sb)->s_groups_count) |
| 1043 | break; |
| 1044 | |
| 1045 | err = -EIO; |
| 1046 | desc = ext4_get_group_desc(sb, first_group + i, NULL); |
| 1047 | if (desc == NULL) |
| 1048 | goto out; |
| 1049 | |
| 1050 | err = -ENOMEM; |
| 1051 | bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc)); |
| 1052 | if (bh[i] == NULL) |
| 1053 | goto out; |
| 1054 | |
| 1055 | if (bh_uptodate_or_lock(bh[i])) |
| 1056 | continue; |
| 1057 | |
| 1058 | if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
| 1059 | ext4_init_block_bitmap(sb, bh[i], |
| 1060 | first_group + i, desc); |
| 1061 | set_buffer_uptodate(bh[i]); |
| 1062 | unlock_buffer(bh[i]); |
| 1063 | continue; |
| 1064 | } |
| 1065 | get_bh(bh[i]); |
| 1066 | bh[i]->b_end_io = end_buffer_read_sync; |
| 1067 | submit_bh(READ, bh[i]); |
| 1068 | mb_debug("read bitmap for group %lu\n", first_group + i); |
| 1069 | } |
| 1070 | |
| 1071 | /* wait for I/O completion */ |
| 1072 | for (i = 0; i < groups_per_page && bh[i]; i++) |
| 1073 | wait_on_buffer(bh[i]); |
| 1074 | |
| 1075 | err = -EIO; |
| 1076 | for (i = 0; i < groups_per_page && bh[i]; i++) |
| 1077 | if (!buffer_uptodate(bh[i])) |
| 1078 | goto out; |
| 1079 | |
| 1080 | first_block = page->index * blocks_per_page; |
| 1081 | for (i = 0; i < blocks_per_page; i++) { |
| 1082 | int group; |
| 1083 | struct ext4_group_info *grinfo; |
| 1084 | |
| 1085 | group = (first_block + i) >> 1; |
| 1086 | if (group >= EXT4_SB(sb)->s_groups_count) |
| 1087 | break; |
| 1088 | |
| 1089 | /* |
| 1090 | * data carry information regarding this |
| 1091 | * particular group in the format specified |
| 1092 | * above |
| 1093 | * |
| 1094 | */ |
| 1095 | data = page_address(page) + (i * blocksize); |
| 1096 | bitmap = bh[group - first_group]->b_data; |
| 1097 | |
| 1098 | /* |
| 1099 | * We place the buddy block and bitmap block |
| 1100 | * close together |
| 1101 | */ |
| 1102 | if ((first_block + i) & 1) { |
| 1103 | /* this is block of buddy */ |
| 1104 | BUG_ON(incore == NULL); |
| 1105 | mb_debug("put buddy for group %u in page %lu/%x\n", |
| 1106 | group, page->index, i * blocksize); |
| 1107 | memset(data, 0xff, blocksize); |
| 1108 | grinfo = ext4_get_group_info(sb, group); |
| 1109 | grinfo->bb_fragments = 0; |
| 1110 | memset(grinfo->bb_counters, 0, |
| 1111 | sizeof(unsigned short)*(sb->s_blocksize_bits+2)); |
| 1112 | /* |
| 1113 | * incore got set to the group block bitmap below |
| 1114 | */ |
| 1115 | ext4_mb_generate_buddy(sb, data, incore, group); |
| 1116 | incore = NULL; |
| 1117 | } else { |
| 1118 | /* this is block of bitmap */ |
| 1119 | BUG_ON(incore != NULL); |
| 1120 | mb_debug("put bitmap for group %u in page %lu/%x\n", |
| 1121 | group, page->index, i * blocksize); |
| 1122 | |
| 1123 | /* see comments in ext4_mb_put_pa() */ |
| 1124 | ext4_lock_group(sb, group); |
| 1125 | memcpy(data, bitmap, blocksize); |
| 1126 | |
| 1127 | /* mark all preallocated blks used in in-core bitmap */ |
| 1128 | ext4_mb_generate_from_pa(sb, data, group); |
| 1129 | ext4_unlock_group(sb, group); |
| 1130 | |
| 1131 | /* set incore so that the buddy information can be |
| 1132 | * generated using this |
| 1133 | */ |
| 1134 | incore = data; |
| 1135 | } |
| 1136 | } |
| 1137 | SetPageUptodate(page); |
| 1138 | |
| 1139 | out: |
| 1140 | if (bh) { |
| 1141 | for (i = 0; i < groups_per_page && bh[i]; i++) |
| 1142 | brelse(bh[i]); |
| 1143 | if (bh != &bhs) |
| 1144 | kfree(bh); |
| 1145 | } |
| 1146 | return err; |
| 1147 | } |
| 1148 | |
| 1149 | static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, |
| 1150 | struct ext4_buddy *e4b) |
| 1151 | { |
| 1152 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 1153 | struct inode *inode = sbi->s_buddy_cache; |
| 1154 | int blocks_per_page; |
| 1155 | int block; |
| 1156 | int pnum; |
| 1157 | int poff; |
| 1158 | struct page *page; |
| 1159 | |
| 1160 | mb_debug("load group %lu\n", group); |
| 1161 | |
| 1162 | blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize; |
| 1163 | |
| 1164 | e4b->bd_blkbits = sb->s_blocksize_bits; |
| 1165 | e4b->bd_info = ext4_get_group_info(sb, group); |
| 1166 | e4b->bd_sb = sb; |
| 1167 | e4b->bd_group = group; |
| 1168 | e4b->bd_buddy_page = NULL; |
| 1169 | e4b->bd_bitmap_page = NULL; |
| 1170 | |
| 1171 | /* |
| 1172 | * the buddy cache inode stores the block bitmap |
| 1173 | * and buddy information in consecutive blocks. |
| 1174 | * So for each group we need two blocks. |
| 1175 | */ |
| 1176 | block = group * 2; |
| 1177 | pnum = block / blocks_per_page; |
| 1178 | poff = block % blocks_per_page; |
| 1179 | |
| 1180 | /* we could use find_or_create_page(), but it locks page |
| 1181 | * what we'd like to avoid in fast path ... */ |
| 1182 | page = find_get_page(inode->i_mapping, pnum); |
| 1183 | if (page == NULL || !PageUptodate(page)) { |
| 1184 | if (page) |
| 1185 | page_cache_release(page); |
| 1186 | page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); |
| 1187 | if (page) { |
| 1188 | BUG_ON(page->mapping != inode->i_mapping); |
| 1189 | if (!PageUptodate(page)) { |
| 1190 | ext4_mb_init_cache(page, NULL); |
| 1191 | mb_cmp_bitmaps(e4b, page_address(page) + |
| 1192 | (poff * sb->s_blocksize)); |
| 1193 | } |
| 1194 | unlock_page(page); |
| 1195 | } |
| 1196 | } |
| 1197 | if (page == NULL || !PageUptodate(page)) |
| 1198 | goto err; |
| 1199 | e4b->bd_bitmap_page = page; |
| 1200 | e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); |
| 1201 | mark_page_accessed(page); |
| 1202 | |
| 1203 | block++; |
| 1204 | pnum = block / blocks_per_page; |
| 1205 | poff = block % blocks_per_page; |
| 1206 | |
| 1207 | page = find_get_page(inode->i_mapping, pnum); |
| 1208 | if (page == NULL || !PageUptodate(page)) { |
| 1209 | if (page) |
| 1210 | page_cache_release(page); |
| 1211 | page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); |
| 1212 | if (page) { |
| 1213 | BUG_ON(page->mapping != inode->i_mapping); |
| 1214 | if (!PageUptodate(page)) |
| 1215 | ext4_mb_init_cache(page, e4b->bd_bitmap); |
| 1216 | |
| 1217 | unlock_page(page); |
| 1218 | } |
| 1219 | } |
| 1220 | if (page == NULL || !PageUptodate(page)) |
| 1221 | goto err; |
| 1222 | e4b->bd_buddy_page = page; |
| 1223 | e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize); |
| 1224 | mark_page_accessed(page); |
| 1225 | |
| 1226 | BUG_ON(e4b->bd_bitmap_page == NULL); |
| 1227 | BUG_ON(e4b->bd_buddy_page == NULL); |
| 1228 | |
| 1229 | return 0; |
| 1230 | |
| 1231 | err: |
| 1232 | if (e4b->bd_bitmap_page) |
| 1233 | page_cache_release(e4b->bd_bitmap_page); |
| 1234 | if (e4b->bd_buddy_page) |
| 1235 | page_cache_release(e4b->bd_buddy_page); |
| 1236 | e4b->bd_buddy = NULL; |
| 1237 | e4b->bd_bitmap = NULL; |
| 1238 | return -EIO; |
| 1239 | } |
| 1240 | |
| 1241 | static void ext4_mb_release_desc(struct ext4_buddy *e4b) |
| 1242 | { |
| 1243 | if (e4b->bd_bitmap_page) |
| 1244 | page_cache_release(e4b->bd_bitmap_page); |
| 1245 | if (e4b->bd_buddy_page) |
| 1246 | page_cache_release(e4b->bd_buddy_page); |
| 1247 | } |
| 1248 | |
| 1249 | |
| 1250 | static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) |
| 1251 | { |
| 1252 | int order = 1; |
| 1253 | void *bb; |
| 1254 | |
| 1255 | BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b)); |
| 1256 | BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); |
| 1257 | |
| 1258 | bb = EXT4_MB_BUDDY(e4b); |
| 1259 | while (order <= e4b->bd_blkbits + 1) { |
| 1260 | block = block >> 1; |
| 1261 | if (!mb_test_bit(block, bb)) { |
| 1262 | /* this block is part of buddy of order 'order' */ |
| 1263 | return order; |
| 1264 | } |
| 1265 | bb += 1 << (e4b->bd_blkbits - order); |
| 1266 | order++; |
| 1267 | } |
| 1268 | return 0; |
| 1269 | } |
| 1270 | |
| 1271 | static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len) |
| 1272 | { |
| 1273 | __u32 *addr; |
| 1274 | |
| 1275 | len = cur + len; |
| 1276 | while (cur < len) { |
| 1277 | if ((cur & 31) == 0 && (len - cur) >= 32) { |
| 1278 | /* fast path: clear whole word at once */ |
| 1279 | addr = bm + (cur >> 3); |
| 1280 | *addr = 0; |
| 1281 | cur += 32; |
| 1282 | continue; |
| 1283 | } |
| 1284 | mb_clear_bit_atomic(lock, cur, bm); |
| 1285 | cur++; |
| 1286 | } |
| 1287 | } |
| 1288 | |
| 1289 | static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len) |
| 1290 | { |
| 1291 | __u32 *addr; |
| 1292 | |
| 1293 | len = cur + len; |
| 1294 | while (cur < len) { |
| 1295 | if ((cur & 31) == 0 && (len - cur) >= 32) { |
| 1296 | /* fast path: set whole word at once */ |
| 1297 | addr = bm + (cur >> 3); |
| 1298 | *addr = 0xffffffff; |
| 1299 | cur += 32; |
| 1300 | continue; |
| 1301 | } |
| 1302 | mb_set_bit_atomic(lock, cur, bm); |
| 1303 | cur++; |
| 1304 | } |
| 1305 | } |
| 1306 | |
| 1307 | static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, |
| 1308 | int first, int count) |
| 1309 | { |
| 1310 | int block = 0; |
| 1311 | int max = 0; |
| 1312 | int order; |
| 1313 | void *buddy; |
| 1314 | void *buddy2; |
| 1315 | struct super_block *sb = e4b->bd_sb; |
| 1316 | |
| 1317 | BUG_ON(first + count > (sb->s_blocksize << 3)); |
| 1318 | BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group)); |
| 1319 | mb_check_buddy(e4b); |
| 1320 | mb_free_blocks_double(inode, e4b, first, count); |
| 1321 | |
| 1322 | e4b->bd_info->bb_free += count; |
| 1323 | if (first < e4b->bd_info->bb_first_free) |
| 1324 | e4b->bd_info->bb_first_free = first; |
| 1325 | |
| 1326 | /* let's maintain fragments counter */ |
| 1327 | if (first != 0) |
| 1328 | block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b)); |
| 1329 | if (first + count < EXT4_SB(sb)->s_mb_maxs[0]) |
| 1330 | max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b)); |
| 1331 | if (block && max) |
| 1332 | e4b->bd_info->bb_fragments--; |
| 1333 | else if (!block && !max) |
| 1334 | e4b->bd_info->bb_fragments++; |
| 1335 | |
| 1336 | /* let's maintain buddy itself */ |
| 1337 | while (count-- > 0) { |
| 1338 | block = first++; |
| 1339 | order = 0; |
| 1340 | |
| 1341 | if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) { |
| 1342 | ext4_fsblk_t blocknr; |
| 1343 | blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb); |
| 1344 | blocknr += block; |
| 1345 | blocknr += |
| 1346 | le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); |
| 1347 | |
| 1348 | ext4_error(sb, __FUNCTION__, "double-free of inode" |
| 1349 | " %lu's block %llu(bit %u in group %lu)\n", |
| 1350 | inode ? inode->i_ino : 0, blocknr, block, |
| 1351 | e4b->bd_group); |
| 1352 | } |
| 1353 | mb_clear_bit(block, EXT4_MB_BITMAP(e4b)); |
| 1354 | e4b->bd_info->bb_counters[order]++; |
| 1355 | |
| 1356 | /* start of the buddy */ |
| 1357 | buddy = mb_find_buddy(e4b, order, &max); |
| 1358 | |
| 1359 | do { |
| 1360 | block &= ~1UL; |
| 1361 | if (mb_test_bit(block, buddy) || |
| 1362 | mb_test_bit(block + 1, buddy)) |
| 1363 | break; |
| 1364 | |
| 1365 | /* both the buddies are free, try to coalesce them */ |
| 1366 | buddy2 = mb_find_buddy(e4b, order + 1, &max); |
| 1367 | |
| 1368 | if (!buddy2) |
| 1369 | break; |
| 1370 | |
| 1371 | if (order > 0) { |
| 1372 | /* for special purposes, we don't set |
| 1373 | * free bits in bitmap */ |
| 1374 | mb_set_bit(block, buddy); |
| 1375 | mb_set_bit(block + 1, buddy); |
| 1376 | } |
| 1377 | e4b->bd_info->bb_counters[order]--; |
| 1378 | e4b->bd_info->bb_counters[order]--; |
| 1379 | |
| 1380 | block = block >> 1; |
| 1381 | order++; |
| 1382 | e4b->bd_info->bb_counters[order]++; |
| 1383 | |
| 1384 | mb_clear_bit(block, buddy2); |
| 1385 | buddy = buddy2; |
| 1386 | } while (1); |
| 1387 | } |
| 1388 | mb_check_buddy(e4b); |
| 1389 | |
| 1390 | return 0; |
| 1391 | } |
| 1392 | |
| 1393 | static int mb_find_extent(struct ext4_buddy *e4b, int order, int block, |
| 1394 | int needed, struct ext4_free_extent *ex) |
| 1395 | { |
| 1396 | int next = block; |
| 1397 | int max; |
| 1398 | int ord; |
| 1399 | void *buddy; |
| 1400 | |
| 1401 | BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); |
| 1402 | BUG_ON(ex == NULL); |
| 1403 | |
| 1404 | buddy = mb_find_buddy(e4b, order, &max); |
| 1405 | BUG_ON(buddy == NULL); |
| 1406 | BUG_ON(block >= max); |
| 1407 | if (mb_test_bit(block, buddy)) { |
| 1408 | ex->fe_len = 0; |
| 1409 | ex->fe_start = 0; |
| 1410 | ex->fe_group = 0; |
| 1411 | return 0; |
| 1412 | } |
| 1413 | |
| 1414 | /* FIXME dorp order completely ? */ |
| 1415 | if (likely(order == 0)) { |
| 1416 | /* find actual order */ |
| 1417 | order = mb_find_order_for_block(e4b, block); |
| 1418 | block = block >> order; |
| 1419 | } |
| 1420 | |
| 1421 | ex->fe_len = 1 << order; |
| 1422 | ex->fe_start = block << order; |
| 1423 | ex->fe_group = e4b->bd_group; |
| 1424 | |
| 1425 | /* calc difference from given start */ |
| 1426 | next = next - ex->fe_start; |
| 1427 | ex->fe_len -= next; |
| 1428 | ex->fe_start += next; |
| 1429 | |
| 1430 | while (needed > ex->fe_len && |
| 1431 | (buddy = mb_find_buddy(e4b, order, &max))) { |
| 1432 | |
| 1433 | if (block + 1 >= max) |
| 1434 | break; |
| 1435 | |
| 1436 | next = (block + 1) * (1 << order); |
| 1437 | if (mb_test_bit(next, EXT4_MB_BITMAP(e4b))) |
| 1438 | break; |
| 1439 | |
| 1440 | ord = mb_find_order_for_block(e4b, next); |
| 1441 | |
| 1442 | order = ord; |
| 1443 | block = next >> order; |
| 1444 | ex->fe_len += 1 << order; |
| 1445 | } |
| 1446 | |
| 1447 | BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3))); |
| 1448 | return ex->fe_len; |
| 1449 | } |
| 1450 | |
| 1451 | static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) |
| 1452 | { |
| 1453 | int ord; |
| 1454 | int mlen = 0; |
| 1455 | int max = 0; |
| 1456 | int cur; |
| 1457 | int start = ex->fe_start; |
| 1458 | int len = ex->fe_len; |
| 1459 | unsigned ret = 0; |
| 1460 | int len0 = len; |
| 1461 | void *buddy; |
| 1462 | |
| 1463 | BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); |
| 1464 | BUG_ON(e4b->bd_group != ex->fe_group); |
| 1465 | BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); |
| 1466 | mb_check_buddy(e4b); |
| 1467 | mb_mark_used_double(e4b, start, len); |
| 1468 | |
| 1469 | e4b->bd_info->bb_free -= len; |
| 1470 | if (e4b->bd_info->bb_first_free == start) |
| 1471 | e4b->bd_info->bb_first_free += len; |
| 1472 | |
| 1473 | /* let's maintain fragments counter */ |
| 1474 | if (start != 0) |
| 1475 | mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b)); |
| 1476 | if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0]) |
| 1477 | max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b)); |
| 1478 | if (mlen && max) |
| 1479 | e4b->bd_info->bb_fragments++; |
| 1480 | else if (!mlen && !max) |
| 1481 | e4b->bd_info->bb_fragments--; |
| 1482 | |
| 1483 | /* let's maintain buddy itself */ |
| 1484 | while (len) { |
| 1485 | ord = mb_find_order_for_block(e4b, start); |
| 1486 | |
| 1487 | if (((start >> ord) << ord) == start && len >= (1 << ord)) { |
| 1488 | /* the whole chunk may be allocated at once! */ |
| 1489 | mlen = 1 << ord; |
| 1490 | buddy = mb_find_buddy(e4b, ord, &max); |
| 1491 | BUG_ON((start >> ord) >= max); |
| 1492 | mb_set_bit(start >> ord, buddy); |
| 1493 | e4b->bd_info->bb_counters[ord]--; |
| 1494 | start += mlen; |
| 1495 | len -= mlen; |
| 1496 | BUG_ON(len < 0); |
| 1497 | continue; |
| 1498 | } |
| 1499 | |
| 1500 | /* store for history */ |
| 1501 | if (ret == 0) |
| 1502 | ret = len | (ord << 16); |
| 1503 | |
| 1504 | /* we have to split large buddy */ |
| 1505 | BUG_ON(ord <= 0); |
| 1506 | buddy = mb_find_buddy(e4b, ord, &max); |
| 1507 | mb_set_bit(start >> ord, buddy); |
| 1508 | e4b->bd_info->bb_counters[ord]--; |
| 1509 | |
| 1510 | ord--; |
| 1511 | cur = (start >> ord) & ~1U; |
| 1512 | buddy = mb_find_buddy(e4b, ord, &max); |
| 1513 | mb_clear_bit(cur, buddy); |
| 1514 | mb_clear_bit(cur + 1, buddy); |
| 1515 | e4b->bd_info->bb_counters[ord]++; |
| 1516 | e4b->bd_info->bb_counters[ord]++; |
| 1517 | } |
| 1518 | |
| 1519 | mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group), |
| 1520 | EXT4_MB_BITMAP(e4b), ex->fe_start, len0); |
| 1521 | mb_check_buddy(e4b); |
| 1522 | |
| 1523 | return ret; |
| 1524 | } |
| 1525 | |
| 1526 | /* |
| 1527 | * Must be called under group lock! |
| 1528 | */ |
| 1529 | static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, |
| 1530 | struct ext4_buddy *e4b) |
| 1531 | { |
| 1532 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| 1533 | int ret; |
| 1534 | |
| 1535 | BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group); |
| 1536 | BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
| 1537 | |
| 1538 | ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len); |
| 1539 | ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical; |
| 1540 | ret = mb_mark_used(e4b, &ac->ac_b_ex); |
| 1541 | |
| 1542 | /* preallocation can change ac_b_ex, thus we store actually |
| 1543 | * allocated blocks for history */ |
| 1544 | ac->ac_f_ex = ac->ac_b_ex; |
| 1545 | |
| 1546 | ac->ac_status = AC_STATUS_FOUND; |
| 1547 | ac->ac_tail = ret & 0xffff; |
| 1548 | ac->ac_buddy = ret >> 16; |
| 1549 | |
| 1550 | /* XXXXXXX: SUCH A HORRIBLE **CK */ |
| 1551 | /*FIXME!! Why ? */ |
| 1552 | ac->ac_bitmap_page = e4b->bd_bitmap_page; |
| 1553 | get_page(ac->ac_bitmap_page); |
| 1554 | ac->ac_buddy_page = e4b->bd_buddy_page; |
| 1555 | get_page(ac->ac_buddy_page); |
| 1556 | |
| 1557 | /* store last allocated for subsequent stream allocation */ |
| 1558 | if ((ac->ac_flags & EXT4_MB_HINT_DATA)) { |
| 1559 | spin_lock(&sbi->s_md_lock); |
| 1560 | sbi->s_mb_last_group = ac->ac_f_ex.fe_group; |
| 1561 | sbi->s_mb_last_start = ac->ac_f_ex.fe_start; |
| 1562 | spin_unlock(&sbi->s_md_lock); |
| 1563 | } |
| 1564 | } |
| 1565 | |
| 1566 | /* |
| 1567 | * regular allocator, for general purposes allocation |
| 1568 | */ |
| 1569 | |
| 1570 | static void ext4_mb_check_limits(struct ext4_allocation_context *ac, |
| 1571 | struct ext4_buddy *e4b, |
| 1572 | int finish_group) |
| 1573 | { |
| 1574 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| 1575 | struct ext4_free_extent *bex = &ac->ac_b_ex; |
| 1576 | struct ext4_free_extent *gex = &ac->ac_g_ex; |
| 1577 | struct ext4_free_extent ex; |
| 1578 | int max; |
| 1579 | |
| 1580 | /* |
| 1581 | * We don't want to scan for a whole year |
| 1582 | */ |
| 1583 | if (ac->ac_found > sbi->s_mb_max_to_scan && |
| 1584 | !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| 1585 | ac->ac_status = AC_STATUS_BREAK; |
| 1586 | return; |
| 1587 | } |
| 1588 | |
| 1589 | /* |
| 1590 | * Haven't found good chunk so far, let's continue |
| 1591 | */ |
| 1592 | if (bex->fe_len < gex->fe_len) |
| 1593 | return; |
| 1594 | |
| 1595 | if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan) |
| 1596 | && bex->fe_group == e4b->bd_group) { |
| 1597 | /* recheck chunk's availability - we don't know |
| 1598 | * when it was found (within this lock-unlock |
| 1599 | * period or not) */ |
| 1600 | max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex); |
| 1601 | if (max >= gex->fe_len) { |
| 1602 | ext4_mb_use_best_found(ac, e4b); |
| 1603 | return; |
| 1604 | } |
| 1605 | } |
| 1606 | } |
| 1607 | |
| 1608 | /* |
| 1609 | * The routine checks whether found extent is good enough. If it is, |
| 1610 | * then the extent gets marked used and flag is set to the context |
| 1611 | * to stop scanning. Otherwise, the extent is compared with the |
| 1612 | * previous found extent and if new one is better, then it's stored |
| 1613 | * in the context. Later, the best found extent will be used, if |
| 1614 | * mballoc can't find good enough extent. |
| 1615 | * |
| 1616 | * FIXME: real allocation policy is to be designed yet! |
| 1617 | */ |
| 1618 | static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, |
| 1619 | struct ext4_free_extent *ex, |
| 1620 | struct ext4_buddy *e4b) |
| 1621 | { |
| 1622 | struct ext4_free_extent *bex = &ac->ac_b_ex; |
| 1623 | struct ext4_free_extent *gex = &ac->ac_g_ex; |
| 1624 | |
| 1625 | BUG_ON(ex->fe_len <= 0); |
| 1626 | BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
| 1627 | BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
| 1628 | BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); |
| 1629 | |
| 1630 | ac->ac_found++; |
| 1631 | |
| 1632 | /* |
| 1633 | * The special case - take what you catch first |
| 1634 | */ |
| 1635 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| 1636 | *bex = *ex; |
| 1637 | ext4_mb_use_best_found(ac, e4b); |
| 1638 | return; |
| 1639 | } |
| 1640 | |
| 1641 | /* |
| 1642 | * Let's check whether the chuck is good enough |
| 1643 | */ |
| 1644 | if (ex->fe_len == gex->fe_len) { |
| 1645 | *bex = *ex; |
| 1646 | ext4_mb_use_best_found(ac, e4b); |
| 1647 | return; |
| 1648 | } |
| 1649 | |
| 1650 | /* |
| 1651 | * If this is first found extent, just store it in the context |
| 1652 | */ |
| 1653 | if (bex->fe_len == 0) { |
| 1654 | *bex = *ex; |
| 1655 | return; |
| 1656 | } |
| 1657 | |
| 1658 | /* |
| 1659 | * If new found extent is better, store it in the context |
| 1660 | */ |
| 1661 | if (bex->fe_len < gex->fe_len) { |
| 1662 | /* if the request isn't satisfied, any found extent |
| 1663 | * larger than previous best one is better */ |
| 1664 | if (ex->fe_len > bex->fe_len) |
| 1665 | *bex = *ex; |
| 1666 | } else if (ex->fe_len > gex->fe_len) { |
| 1667 | /* if the request is satisfied, then we try to find |
| 1668 | * an extent that still satisfy the request, but is |
| 1669 | * smaller than previous one */ |
| 1670 | if (ex->fe_len < bex->fe_len) |
| 1671 | *bex = *ex; |
| 1672 | } |
| 1673 | |
| 1674 | ext4_mb_check_limits(ac, e4b, 0); |
| 1675 | } |
| 1676 | |
| 1677 | static int ext4_mb_try_best_found(struct ext4_allocation_context *ac, |
| 1678 | struct ext4_buddy *e4b) |
| 1679 | { |
| 1680 | struct ext4_free_extent ex = ac->ac_b_ex; |
| 1681 | ext4_group_t group = ex.fe_group; |
| 1682 | int max; |
| 1683 | int err; |
| 1684 | |
| 1685 | BUG_ON(ex.fe_len <= 0); |
| 1686 | err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
| 1687 | if (err) |
| 1688 | return err; |
| 1689 | |
| 1690 | ext4_lock_group(ac->ac_sb, group); |
| 1691 | max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex); |
| 1692 | |
| 1693 | if (max > 0) { |
| 1694 | ac->ac_b_ex = ex; |
| 1695 | ext4_mb_use_best_found(ac, e4b); |
| 1696 | } |
| 1697 | |
| 1698 | ext4_unlock_group(ac->ac_sb, group); |
| 1699 | ext4_mb_release_desc(e4b); |
| 1700 | |
| 1701 | return 0; |
| 1702 | } |
| 1703 | |
| 1704 | static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac, |
| 1705 | struct ext4_buddy *e4b) |
| 1706 | { |
| 1707 | ext4_group_t group = ac->ac_g_ex.fe_group; |
| 1708 | int max; |
| 1709 | int err; |
| 1710 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| 1711 | struct ext4_super_block *es = sbi->s_es; |
| 1712 | struct ext4_free_extent ex; |
| 1713 | |
| 1714 | if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL)) |
| 1715 | return 0; |
| 1716 | |
| 1717 | err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
| 1718 | if (err) |
| 1719 | return err; |
| 1720 | |
| 1721 | ext4_lock_group(ac->ac_sb, group); |
| 1722 | max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start, |
| 1723 | ac->ac_g_ex.fe_len, &ex); |
| 1724 | |
| 1725 | if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) { |
| 1726 | ext4_fsblk_t start; |
| 1727 | |
| 1728 | start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) + |
| 1729 | ex.fe_start + le32_to_cpu(es->s_first_data_block); |
| 1730 | /* use do_div to get remainder (would be 64-bit modulo) */ |
| 1731 | if (do_div(start, sbi->s_stripe) == 0) { |
| 1732 | ac->ac_found++; |
| 1733 | ac->ac_b_ex = ex; |
| 1734 | ext4_mb_use_best_found(ac, e4b); |
| 1735 | } |
| 1736 | } else if (max >= ac->ac_g_ex.fe_len) { |
| 1737 | BUG_ON(ex.fe_len <= 0); |
| 1738 | BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
| 1739 | BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
| 1740 | ac->ac_found++; |
| 1741 | ac->ac_b_ex = ex; |
| 1742 | ext4_mb_use_best_found(ac, e4b); |
| 1743 | } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) { |
| 1744 | /* Sometimes, caller may want to merge even small |
| 1745 | * number of blocks to an existing extent */ |
| 1746 | BUG_ON(ex.fe_len <= 0); |
| 1747 | BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
| 1748 | BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
| 1749 | ac->ac_found++; |
| 1750 | ac->ac_b_ex = ex; |
| 1751 | ext4_mb_use_best_found(ac, e4b); |
| 1752 | } |
| 1753 | ext4_unlock_group(ac->ac_sb, group); |
| 1754 | ext4_mb_release_desc(e4b); |
| 1755 | |
| 1756 | return 0; |
| 1757 | } |
| 1758 | |
| 1759 | /* |
| 1760 | * The routine scans buddy structures (not bitmap!) from given order |
| 1761 | * to max order and tries to find big enough chunk to satisfy the req |
| 1762 | */ |
| 1763 | static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, |
| 1764 | struct ext4_buddy *e4b) |
| 1765 | { |
| 1766 | struct super_block *sb = ac->ac_sb; |
| 1767 | struct ext4_group_info *grp = e4b->bd_info; |
| 1768 | void *buddy; |
| 1769 | int i; |
| 1770 | int k; |
| 1771 | int max; |
| 1772 | |
| 1773 | BUG_ON(ac->ac_2order <= 0); |
| 1774 | for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) { |
| 1775 | if (grp->bb_counters[i] == 0) |
| 1776 | continue; |
| 1777 | |
| 1778 | buddy = mb_find_buddy(e4b, i, &max); |
| 1779 | BUG_ON(buddy == NULL); |
| 1780 | |
| 1781 | k = ext4_find_next_zero_bit(buddy, max, 0); |
| 1782 | BUG_ON(k >= max); |
| 1783 | |
| 1784 | ac->ac_found++; |
| 1785 | |
| 1786 | ac->ac_b_ex.fe_len = 1 << i; |
| 1787 | ac->ac_b_ex.fe_start = k << i; |
| 1788 | ac->ac_b_ex.fe_group = e4b->bd_group; |
| 1789 | |
| 1790 | ext4_mb_use_best_found(ac, e4b); |
| 1791 | |
| 1792 | BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len); |
| 1793 | |
| 1794 | if (EXT4_SB(sb)->s_mb_stats) |
| 1795 | atomic_inc(&EXT4_SB(sb)->s_bal_2orders); |
| 1796 | |
| 1797 | break; |
| 1798 | } |
| 1799 | } |
| 1800 | |
| 1801 | /* |
| 1802 | * The routine scans the group and measures all found extents. |
| 1803 | * In order to optimize scanning, caller must pass number of |
| 1804 | * free blocks in the group, so the routine can know upper limit. |
| 1805 | */ |
| 1806 | static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, |
| 1807 | struct ext4_buddy *e4b) |
| 1808 | { |
| 1809 | struct super_block *sb = ac->ac_sb; |
| 1810 | void *bitmap = EXT4_MB_BITMAP(e4b); |
| 1811 | struct ext4_free_extent ex; |
| 1812 | int i; |
| 1813 | int free; |
| 1814 | |
| 1815 | free = e4b->bd_info->bb_free; |
| 1816 | BUG_ON(free <= 0); |
| 1817 | |
| 1818 | i = e4b->bd_info->bb_first_free; |
| 1819 | |
| 1820 | while (free && ac->ac_status == AC_STATUS_CONTINUE) { |
| 1821 | i = ext4_find_next_zero_bit(bitmap, |
| 1822 | EXT4_BLOCKS_PER_GROUP(sb), i); |
| 1823 | if (i >= EXT4_BLOCKS_PER_GROUP(sb)) { |
| 1824 | BUG_ON(free != 0); |
| 1825 | break; |
| 1826 | } |
| 1827 | |
| 1828 | mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex); |
| 1829 | BUG_ON(ex.fe_len <= 0); |
| 1830 | BUG_ON(free < ex.fe_len); |
| 1831 | |
| 1832 | ext4_mb_measure_extent(ac, &ex, e4b); |
| 1833 | |
| 1834 | i += ex.fe_len; |
| 1835 | free -= ex.fe_len; |
| 1836 | } |
| 1837 | |
| 1838 | ext4_mb_check_limits(ac, e4b, 1); |
| 1839 | } |
| 1840 | |
| 1841 | /* |
| 1842 | * This is a special case for storages like raid5 |
| 1843 | * we try to find stripe-aligned chunks for stripe-size requests |
| 1844 | * XXX should do so at least for multiples of stripe size as well |
| 1845 | */ |
| 1846 | static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, |
| 1847 | struct ext4_buddy *e4b) |
| 1848 | { |
| 1849 | struct super_block *sb = ac->ac_sb; |
| 1850 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 1851 | void *bitmap = EXT4_MB_BITMAP(e4b); |
| 1852 | struct ext4_free_extent ex; |
| 1853 | ext4_fsblk_t first_group_block; |
| 1854 | ext4_fsblk_t a; |
| 1855 | ext4_grpblk_t i; |
| 1856 | int max; |
| 1857 | |
| 1858 | BUG_ON(sbi->s_stripe == 0); |
| 1859 | |
| 1860 | /* find first stripe-aligned block in group */ |
| 1861 | first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb) |
| 1862 | + le32_to_cpu(sbi->s_es->s_first_data_block); |
| 1863 | a = first_group_block + sbi->s_stripe - 1; |
| 1864 | do_div(a, sbi->s_stripe); |
| 1865 | i = (a * sbi->s_stripe) - first_group_block; |
| 1866 | |
| 1867 | while (i < EXT4_BLOCKS_PER_GROUP(sb)) { |
| 1868 | if (!mb_test_bit(i, bitmap)) { |
| 1869 | max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex); |
| 1870 | if (max >= sbi->s_stripe) { |
| 1871 | ac->ac_found++; |
| 1872 | ac->ac_b_ex = ex; |
| 1873 | ext4_mb_use_best_found(ac, e4b); |
| 1874 | break; |
| 1875 | } |
| 1876 | } |
| 1877 | i += sbi->s_stripe; |
| 1878 | } |
| 1879 | } |
| 1880 | |
| 1881 | static int ext4_mb_good_group(struct ext4_allocation_context *ac, |
| 1882 | ext4_group_t group, int cr) |
| 1883 | { |
| 1884 | unsigned free, fragments; |
| 1885 | unsigned i, bits; |
| 1886 | struct ext4_group_desc *desc; |
| 1887 | struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
| 1888 | |
| 1889 | BUG_ON(cr < 0 || cr >= 4); |
| 1890 | BUG_ON(EXT4_MB_GRP_NEED_INIT(grp)); |
| 1891 | |
| 1892 | free = grp->bb_free; |
| 1893 | fragments = grp->bb_fragments; |
| 1894 | if (free == 0) |
| 1895 | return 0; |
| 1896 | if (fragments == 0) |
| 1897 | return 0; |
| 1898 | |
| 1899 | switch (cr) { |
| 1900 | case 0: |
| 1901 | BUG_ON(ac->ac_2order == 0); |
| 1902 | /* If this group is uninitialized, skip it initially */ |
| 1903 | desc = ext4_get_group_desc(ac->ac_sb, group, NULL); |
| 1904 | if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) |
| 1905 | return 0; |
| 1906 | |
| 1907 | bits = ac->ac_sb->s_blocksize_bits + 1; |
| 1908 | for (i = ac->ac_2order; i <= bits; i++) |
| 1909 | if (grp->bb_counters[i] > 0) |
| 1910 | return 1; |
| 1911 | break; |
| 1912 | case 1: |
| 1913 | if ((free / fragments) >= ac->ac_g_ex.fe_len) |
| 1914 | return 1; |
| 1915 | break; |
| 1916 | case 2: |
| 1917 | if (free >= ac->ac_g_ex.fe_len) |
| 1918 | return 1; |
| 1919 | break; |
| 1920 | case 3: |
| 1921 | return 1; |
| 1922 | default: |
| 1923 | BUG(); |
| 1924 | } |
| 1925 | |
| 1926 | return 0; |
| 1927 | } |
| 1928 | |
| 1929 | static int ext4_mb_regular_allocator(struct ext4_allocation_context *ac) |
| 1930 | { |
| 1931 | ext4_group_t group; |
| 1932 | ext4_group_t i; |
| 1933 | int cr; |
| 1934 | int err = 0; |
| 1935 | int bsbits; |
| 1936 | struct ext4_sb_info *sbi; |
| 1937 | struct super_block *sb; |
| 1938 | struct ext4_buddy e4b; |
| 1939 | loff_t size, isize; |
| 1940 | |
| 1941 | sb = ac->ac_sb; |
| 1942 | sbi = EXT4_SB(sb); |
| 1943 | BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
| 1944 | |
| 1945 | /* first, try the goal */ |
| 1946 | err = ext4_mb_find_by_goal(ac, &e4b); |
| 1947 | if (err || ac->ac_status == AC_STATUS_FOUND) |
| 1948 | goto out; |
| 1949 | |
| 1950 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| 1951 | goto out; |
| 1952 | |
| 1953 | /* |
| 1954 | * ac->ac2_order is set only if the fe_len is a power of 2 |
| 1955 | * if ac2_order is set we also set criteria to 0 so that we |
| 1956 | * try exact allocation using buddy. |
| 1957 | */ |
| 1958 | i = fls(ac->ac_g_ex.fe_len); |
| 1959 | ac->ac_2order = 0; |
| 1960 | /* |
| 1961 | * We search using buddy data only if the order of the request |
| 1962 | * is greater than equal to the sbi_s_mb_order2_reqs |
| 1963 | * You can tune it via /proc/fs/ext4/<partition>/order2_req |
| 1964 | */ |
| 1965 | if (i >= sbi->s_mb_order2_reqs) { |
| 1966 | /* |
| 1967 | * This should tell if fe_len is exactly power of 2 |
| 1968 | */ |
| 1969 | if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0) |
| 1970 | ac->ac_2order = i - 1; |
| 1971 | } |
| 1972 | |
| 1973 | bsbits = ac->ac_sb->s_blocksize_bits; |
| 1974 | /* if stream allocation is enabled, use global goal */ |
| 1975 | size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; |
| 1976 | isize = i_size_read(ac->ac_inode) >> bsbits; |
| 1977 | if (size < isize) |
| 1978 | size = isize; |
| 1979 | |
| 1980 | if (size < sbi->s_mb_stream_request && |
| 1981 | (ac->ac_flags & EXT4_MB_HINT_DATA)) { |
| 1982 | /* TBD: may be hot point */ |
| 1983 | spin_lock(&sbi->s_md_lock); |
| 1984 | ac->ac_g_ex.fe_group = sbi->s_mb_last_group; |
| 1985 | ac->ac_g_ex.fe_start = sbi->s_mb_last_start; |
| 1986 | spin_unlock(&sbi->s_md_lock); |
| 1987 | } |
| 1988 | |
| 1989 | /* searching for the right group start from the goal value specified */ |
| 1990 | group = ac->ac_g_ex.fe_group; |
| 1991 | |
| 1992 | /* Let's just scan groups to find more-less suitable blocks */ |
| 1993 | cr = ac->ac_2order ? 0 : 1; |
| 1994 | /* |
| 1995 | * cr == 0 try to get exact allocation, |
| 1996 | * cr == 3 try to get anything |
| 1997 | */ |
| 1998 | repeat: |
| 1999 | for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) { |
| 2000 | ac->ac_criteria = cr; |
| 2001 | for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) { |
| 2002 | struct ext4_group_info *grp; |
| 2003 | struct ext4_group_desc *desc; |
| 2004 | |
| 2005 | if (group == EXT4_SB(sb)->s_groups_count) |
| 2006 | group = 0; |
| 2007 | |
| 2008 | /* quick check to skip empty groups */ |
| 2009 | grp = ext4_get_group_info(ac->ac_sb, group); |
| 2010 | if (grp->bb_free == 0) |
| 2011 | continue; |
| 2012 | |
| 2013 | /* |
| 2014 | * if the group is already init we check whether it is |
| 2015 | * a good group and if not we don't load the buddy |
| 2016 | */ |
| 2017 | if (EXT4_MB_GRP_NEED_INIT(grp)) { |
| 2018 | /* |
| 2019 | * we need full data about the group |
| 2020 | * to make a good selection |
| 2021 | */ |
| 2022 | err = ext4_mb_load_buddy(sb, group, &e4b); |
| 2023 | if (err) |
| 2024 | goto out; |
| 2025 | ext4_mb_release_desc(&e4b); |
| 2026 | } |
| 2027 | |
| 2028 | /* |
| 2029 | * If the particular group doesn't satisfy our |
| 2030 | * criteria we continue with the next group |
| 2031 | */ |
| 2032 | if (!ext4_mb_good_group(ac, group, cr)) |
| 2033 | continue; |
| 2034 | |
| 2035 | err = ext4_mb_load_buddy(sb, group, &e4b); |
| 2036 | if (err) |
| 2037 | goto out; |
| 2038 | |
| 2039 | ext4_lock_group(sb, group); |
| 2040 | if (!ext4_mb_good_group(ac, group, cr)) { |
| 2041 | /* someone did allocation from this group */ |
| 2042 | ext4_unlock_group(sb, group); |
| 2043 | ext4_mb_release_desc(&e4b); |
| 2044 | continue; |
| 2045 | } |
| 2046 | |
| 2047 | ac->ac_groups_scanned++; |
| 2048 | desc = ext4_get_group_desc(sb, group, NULL); |
| 2049 | if (cr == 0 || (desc->bg_flags & |
| 2050 | cpu_to_le16(EXT4_BG_BLOCK_UNINIT) && |
| 2051 | ac->ac_2order != 0)) |
| 2052 | ext4_mb_simple_scan_group(ac, &e4b); |
| 2053 | else if (cr == 1 && |
| 2054 | ac->ac_g_ex.fe_len == sbi->s_stripe) |
| 2055 | ext4_mb_scan_aligned(ac, &e4b); |
| 2056 | else |
| 2057 | ext4_mb_complex_scan_group(ac, &e4b); |
| 2058 | |
| 2059 | ext4_unlock_group(sb, group); |
| 2060 | ext4_mb_release_desc(&e4b); |
| 2061 | |
| 2062 | if (ac->ac_status != AC_STATUS_CONTINUE) |
| 2063 | break; |
| 2064 | } |
| 2065 | } |
| 2066 | |
| 2067 | if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && |
| 2068 | !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| 2069 | /* |
| 2070 | * We've been searching too long. Let's try to allocate |
| 2071 | * the best chunk we've found so far |
| 2072 | */ |
| 2073 | |
| 2074 | ext4_mb_try_best_found(ac, &e4b); |
| 2075 | if (ac->ac_status != AC_STATUS_FOUND) { |
| 2076 | /* |
| 2077 | * Someone more lucky has already allocated it. |
| 2078 | * The only thing we can do is just take first |
| 2079 | * found block(s) |
| 2080 | printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n"); |
| 2081 | */ |
| 2082 | ac->ac_b_ex.fe_group = 0; |
| 2083 | ac->ac_b_ex.fe_start = 0; |
| 2084 | ac->ac_b_ex.fe_len = 0; |
| 2085 | ac->ac_status = AC_STATUS_CONTINUE; |
| 2086 | ac->ac_flags |= EXT4_MB_HINT_FIRST; |
| 2087 | cr = 3; |
| 2088 | atomic_inc(&sbi->s_mb_lost_chunks); |
| 2089 | goto repeat; |
| 2090 | } |
| 2091 | } |
| 2092 | out: |
| 2093 | return err; |
| 2094 | } |
| 2095 | |
| 2096 | #ifdef EXT4_MB_HISTORY |
| 2097 | struct ext4_mb_proc_session { |
| 2098 | struct ext4_mb_history *history; |
| 2099 | struct super_block *sb; |
| 2100 | int start; |
| 2101 | int max; |
| 2102 | }; |
| 2103 | |
| 2104 | static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s, |
| 2105 | struct ext4_mb_history *hs, |
| 2106 | int first) |
| 2107 | { |
| 2108 | if (hs == s->history + s->max) |
| 2109 | hs = s->history; |
| 2110 | if (!first && hs == s->history + s->start) |
| 2111 | return NULL; |
| 2112 | while (hs->orig.fe_len == 0) { |
| 2113 | hs++; |
| 2114 | if (hs == s->history + s->max) |
| 2115 | hs = s->history; |
| 2116 | if (hs == s->history + s->start) |
| 2117 | return NULL; |
| 2118 | } |
| 2119 | return hs; |
| 2120 | } |
| 2121 | |
| 2122 | static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos) |
| 2123 | { |
| 2124 | struct ext4_mb_proc_session *s = seq->private; |
| 2125 | struct ext4_mb_history *hs; |
| 2126 | int l = *pos; |
| 2127 | |
| 2128 | if (l == 0) |
| 2129 | return SEQ_START_TOKEN; |
| 2130 | hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1); |
| 2131 | if (!hs) |
| 2132 | return NULL; |
| 2133 | while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL); |
| 2134 | return hs; |
| 2135 | } |
| 2136 | |
| 2137 | static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v, |
| 2138 | loff_t *pos) |
| 2139 | { |
| 2140 | struct ext4_mb_proc_session *s = seq->private; |
| 2141 | struct ext4_mb_history *hs = v; |
| 2142 | |
| 2143 | ++*pos; |
| 2144 | if (v == SEQ_START_TOKEN) |
| 2145 | return ext4_mb_history_skip_empty(s, s->history + s->start, 1); |
| 2146 | else |
| 2147 | return ext4_mb_history_skip_empty(s, ++hs, 0); |
| 2148 | } |
| 2149 | |
| 2150 | static int ext4_mb_seq_history_show(struct seq_file *seq, void *v) |
| 2151 | { |
| 2152 | char buf[25], buf2[25], buf3[25], *fmt; |
| 2153 | struct ext4_mb_history *hs = v; |
| 2154 | |
| 2155 | if (v == SEQ_START_TOKEN) { |
| 2156 | seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s " |
| 2157 | "%-5s %-2s %-5s %-5s %-5s %-6s\n", |
| 2158 | "pid", "inode", "original", "goal", "result", "found", |
| 2159 | "grps", "cr", "flags", "merge", "tail", "broken"); |
| 2160 | return 0; |
| 2161 | } |
| 2162 | |
| 2163 | if (hs->op == EXT4_MB_HISTORY_ALLOC) { |
| 2164 | fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u " |
| 2165 | "%-5u %-5s %-5u %-6u\n"; |
| 2166 | sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group, |
| 2167 | hs->result.fe_start, hs->result.fe_len, |
| 2168 | hs->result.fe_logical); |
| 2169 | sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group, |
| 2170 | hs->orig.fe_start, hs->orig.fe_len, |
| 2171 | hs->orig.fe_logical); |
| 2172 | sprintf(buf3, "%lu/%d/%u@%u", hs->goal.fe_group, |
| 2173 | hs->goal.fe_start, hs->goal.fe_len, |
| 2174 | hs->goal.fe_logical); |
| 2175 | seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2, |
| 2176 | hs->found, hs->groups, hs->cr, hs->flags, |
| 2177 | hs->merged ? "M" : "", hs->tail, |
| 2178 | hs->buddy ? 1 << hs->buddy : 0); |
| 2179 | } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) { |
| 2180 | fmt = "%-5u %-8u %-23s %-23s %-23s\n"; |
| 2181 | sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group, |
| 2182 | hs->result.fe_start, hs->result.fe_len, |
| 2183 | hs->result.fe_logical); |
| 2184 | sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group, |
| 2185 | hs->orig.fe_start, hs->orig.fe_len, |
| 2186 | hs->orig.fe_logical); |
| 2187 | seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2); |
| 2188 | } else if (hs->op == EXT4_MB_HISTORY_DISCARD) { |
| 2189 | sprintf(buf2, "%lu/%d/%u", hs->result.fe_group, |
| 2190 | hs->result.fe_start, hs->result.fe_len); |
| 2191 | seq_printf(seq, "%-5u %-8u %-23s discard\n", |
| 2192 | hs->pid, hs->ino, buf2); |
| 2193 | } else if (hs->op == EXT4_MB_HISTORY_FREE) { |
| 2194 | sprintf(buf2, "%lu/%d/%u", hs->result.fe_group, |
| 2195 | hs->result.fe_start, hs->result.fe_len); |
| 2196 | seq_printf(seq, "%-5u %-8u %-23s free\n", |
| 2197 | hs->pid, hs->ino, buf2); |
| 2198 | } |
| 2199 | return 0; |
| 2200 | } |
| 2201 | |
| 2202 | static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v) |
| 2203 | { |
| 2204 | } |
| 2205 | |
| 2206 | static struct seq_operations ext4_mb_seq_history_ops = { |
| 2207 | .start = ext4_mb_seq_history_start, |
| 2208 | .next = ext4_mb_seq_history_next, |
| 2209 | .stop = ext4_mb_seq_history_stop, |
| 2210 | .show = ext4_mb_seq_history_show, |
| 2211 | }; |
| 2212 | |
| 2213 | static int ext4_mb_seq_history_open(struct inode *inode, struct file *file) |
| 2214 | { |
| 2215 | struct super_block *sb = PDE(inode)->data; |
| 2216 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2217 | struct ext4_mb_proc_session *s; |
| 2218 | int rc; |
| 2219 | int size; |
| 2220 | |
| 2221 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
| 2222 | if (s == NULL) |
| 2223 | return -ENOMEM; |
| 2224 | s->sb = sb; |
| 2225 | size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max; |
| 2226 | s->history = kmalloc(size, GFP_KERNEL); |
| 2227 | if (s->history == NULL) { |
| 2228 | kfree(s); |
| 2229 | return -ENOMEM; |
| 2230 | } |
| 2231 | |
| 2232 | spin_lock(&sbi->s_mb_history_lock); |
| 2233 | memcpy(s->history, sbi->s_mb_history, size); |
| 2234 | s->max = sbi->s_mb_history_max; |
| 2235 | s->start = sbi->s_mb_history_cur % s->max; |
| 2236 | spin_unlock(&sbi->s_mb_history_lock); |
| 2237 | |
| 2238 | rc = seq_open(file, &ext4_mb_seq_history_ops); |
| 2239 | if (rc == 0) { |
| 2240 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 2241 | m->private = s; |
| 2242 | } else { |
| 2243 | kfree(s->history); |
| 2244 | kfree(s); |
| 2245 | } |
| 2246 | return rc; |
| 2247 | |
| 2248 | } |
| 2249 | |
| 2250 | static int ext4_mb_seq_history_release(struct inode *inode, struct file *file) |
| 2251 | { |
| 2252 | struct seq_file *seq = (struct seq_file *)file->private_data; |
| 2253 | struct ext4_mb_proc_session *s = seq->private; |
| 2254 | kfree(s->history); |
| 2255 | kfree(s); |
| 2256 | return seq_release(inode, file); |
| 2257 | } |
| 2258 | |
| 2259 | static ssize_t ext4_mb_seq_history_write(struct file *file, |
| 2260 | const char __user *buffer, |
| 2261 | size_t count, loff_t *ppos) |
| 2262 | { |
| 2263 | struct seq_file *seq = (struct seq_file *)file->private_data; |
| 2264 | struct ext4_mb_proc_session *s = seq->private; |
| 2265 | struct super_block *sb = s->sb; |
| 2266 | char str[32]; |
| 2267 | int value; |
| 2268 | |
| 2269 | if (count >= sizeof(str)) { |
| 2270 | printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n", |
| 2271 | "mb_history", (int)sizeof(str)); |
| 2272 | return -EOVERFLOW; |
| 2273 | } |
| 2274 | |
| 2275 | if (copy_from_user(str, buffer, count)) |
| 2276 | return -EFAULT; |
| 2277 | |
| 2278 | value = simple_strtol(str, NULL, 0); |
| 2279 | if (value < 0) |
| 2280 | return -ERANGE; |
| 2281 | EXT4_SB(sb)->s_mb_history_filter = value; |
| 2282 | |
| 2283 | return count; |
| 2284 | } |
| 2285 | |
| 2286 | static struct file_operations ext4_mb_seq_history_fops = { |
| 2287 | .owner = THIS_MODULE, |
| 2288 | .open = ext4_mb_seq_history_open, |
| 2289 | .read = seq_read, |
| 2290 | .write = ext4_mb_seq_history_write, |
| 2291 | .llseek = seq_lseek, |
| 2292 | .release = ext4_mb_seq_history_release, |
| 2293 | }; |
| 2294 | |
| 2295 | static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) |
| 2296 | { |
| 2297 | struct super_block *sb = seq->private; |
| 2298 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2299 | ext4_group_t group; |
| 2300 | |
| 2301 | if (*pos < 0 || *pos >= sbi->s_groups_count) |
| 2302 | return NULL; |
| 2303 | |
| 2304 | group = *pos + 1; |
| 2305 | return (void *) group; |
| 2306 | } |
| 2307 | |
| 2308 | static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) |
| 2309 | { |
| 2310 | struct super_block *sb = seq->private; |
| 2311 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2312 | ext4_group_t group; |
| 2313 | |
| 2314 | ++*pos; |
| 2315 | if (*pos < 0 || *pos >= sbi->s_groups_count) |
| 2316 | return NULL; |
| 2317 | group = *pos + 1; |
| 2318 | return (void *) group;; |
| 2319 | } |
| 2320 | |
| 2321 | static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) |
| 2322 | { |
| 2323 | struct super_block *sb = seq->private; |
| 2324 | long group = (long) v; |
| 2325 | int i; |
| 2326 | int err; |
| 2327 | struct ext4_buddy e4b; |
| 2328 | struct sg { |
| 2329 | struct ext4_group_info info; |
| 2330 | unsigned short counters[16]; |
| 2331 | } sg; |
| 2332 | |
| 2333 | group--; |
| 2334 | if (group == 0) |
| 2335 | seq_printf(seq, "#%-5s: %-5s %-5s %-5s " |
| 2336 | "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s " |
| 2337 | "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n", |
| 2338 | "group", "free", "frags", "first", |
| 2339 | "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6", |
| 2340 | "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13"); |
| 2341 | |
| 2342 | i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) + |
| 2343 | sizeof(struct ext4_group_info); |
| 2344 | err = ext4_mb_load_buddy(sb, group, &e4b); |
| 2345 | if (err) { |
| 2346 | seq_printf(seq, "#%-5lu: I/O error\n", group); |
| 2347 | return 0; |
| 2348 | } |
| 2349 | ext4_lock_group(sb, group); |
| 2350 | memcpy(&sg, ext4_get_group_info(sb, group), i); |
| 2351 | ext4_unlock_group(sb, group); |
| 2352 | ext4_mb_release_desc(&e4b); |
| 2353 | |
| 2354 | seq_printf(seq, "#%-5lu: %-5u %-5u %-5u [", group, sg.info.bb_free, |
| 2355 | sg.info.bb_fragments, sg.info.bb_first_free); |
| 2356 | for (i = 0; i <= 13; i++) |
| 2357 | seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ? |
| 2358 | sg.info.bb_counters[i] : 0); |
| 2359 | seq_printf(seq, " ]\n"); |
| 2360 | |
| 2361 | return 0; |
| 2362 | } |
| 2363 | |
| 2364 | static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v) |
| 2365 | { |
| 2366 | } |
| 2367 | |
| 2368 | static struct seq_operations ext4_mb_seq_groups_ops = { |
| 2369 | .start = ext4_mb_seq_groups_start, |
| 2370 | .next = ext4_mb_seq_groups_next, |
| 2371 | .stop = ext4_mb_seq_groups_stop, |
| 2372 | .show = ext4_mb_seq_groups_show, |
| 2373 | }; |
| 2374 | |
| 2375 | static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file) |
| 2376 | { |
| 2377 | struct super_block *sb = PDE(inode)->data; |
| 2378 | int rc; |
| 2379 | |
| 2380 | rc = seq_open(file, &ext4_mb_seq_groups_ops); |
| 2381 | if (rc == 0) { |
| 2382 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 2383 | m->private = sb; |
| 2384 | } |
| 2385 | return rc; |
| 2386 | |
| 2387 | } |
| 2388 | |
| 2389 | static struct file_operations ext4_mb_seq_groups_fops = { |
| 2390 | .owner = THIS_MODULE, |
| 2391 | .open = ext4_mb_seq_groups_open, |
| 2392 | .read = seq_read, |
| 2393 | .llseek = seq_lseek, |
| 2394 | .release = seq_release, |
| 2395 | }; |
| 2396 | |
| 2397 | static void ext4_mb_history_release(struct super_block *sb) |
| 2398 | { |
| 2399 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2400 | |
| 2401 | remove_proc_entry("mb_groups", sbi->s_mb_proc); |
| 2402 | remove_proc_entry("mb_history", sbi->s_mb_proc); |
| 2403 | |
| 2404 | kfree(sbi->s_mb_history); |
| 2405 | } |
| 2406 | |
| 2407 | static void ext4_mb_history_init(struct super_block *sb) |
| 2408 | { |
| 2409 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2410 | int i; |
| 2411 | |
| 2412 | if (sbi->s_mb_proc != NULL) { |
| 2413 | struct proc_dir_entry *p; |
| 2414 | p = create_proc_entry("mb_history", S_IRUGO, sbi->s_mb_proc); |
| 2415 | if (p) { |
| 2416 | p->proc_fops = &ext4_mb_seq_history_fops; |
| 2417 | p->data = sb; |
| 2418 | } |
| 2419 | p = create_proc_entry("mb_groups", S_IRUGO, sbi->s_mb_proc); |
| 2420 | if (p) { |
| 2421 | p->proc_fops = &ext4_mb_seq_groups_fops; |
| 2422 | p->data = sb; |
| 2423 | } |
| 2424 | } |
| 2425 | |
| 2426 | sbi->s_mb_history_max = 1000; |
| 2427 | sbi->s_mb_history_cur = 0; |
| 2428 | spin_lock_init(&sbi->s_mb_history_lock); |
| 2429 | i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history); |
| 2430 | sbi->s_mb_history = kmalloc(i, GFP_KERNEL); |
| 2431 | if (likely(sbi->s_mb_history != NULL)) |
| 2432 | memset(sbi->s_mb_history, 0, i); |
| 2433 | /* if we can't allocate history, then we simple won't use it */ |
| 2434 | } |
| 2435 | |
| 2436 | static void ext4_mb_store_history(struct ext4_allocation_context *ac) |
| 2437 | { |
| 2438 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| 2439 | struct ext4_mb_history h; |
| 2440 | |
| 2441 | if (unlikely(sbi->s_mb_history == NULL)) |
| 2442 | return; |
| 2443 | |
| 2444 | if (!(ac->ac_op & sbi->s_mb_history_filter)) |
| 2445 | return; |
| 2446 | |
| 2447 | h.op = ac->ac_op; |
| 2448 | h.pid = current->pid; |
| 2449 | h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0; |
| 2450 | h.orig = ac->ac_o_ex; |
| 2451 | h.result = ac->ac_b_ex; |
| 2452 | h.flags = ac->ac_flags; |
| 2453 | h.found = ac->ac_found; |
| 2454 | h.groups = ac->ac_groups_scanned; |
| 2455 | h.cr = ac->ac_criteria; |
| 2456 | h.tail = ac->ac_tail; |
| 2457 | h.buddy = ac->ac_buddy; |
| 2458 | h.merged = 0; |
| 2459 | if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) { |
| 2460 | if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && |
| 2461 | ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) |
| 2462 | h.merged = 1; |
| 2463 | h.goal = ac->ac_g_ex; |
| 2464 | h.result = ac->ac_f_ex; |
| 2465 | } |
| 2466 | |
| 2467 | spin_lock(&sbi->s_mb_history_lock); |
| 2468 | memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h)); |
| 2469 | if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max) |
| 2470 | sbi->s_mb_history_cur = 0; |
| 2471 | spin_unlock(&sbi->s_mb_history_lock); |
| 2472 | } |
| 2473 | |
| 2474 | #else |
| 2475 | #define ext4_mb_history_release(sb) |
| 2476 | #define ext4_mb_history_init(sb) |
| 2477 | #endif |
| 2478 | |
| 2479 | static int ext4_mb_init_backend(struct super_block *sb) |
| 2480 | { |
| 2481 | ext4_group_t i; |
| 2482 | int j, len, metalen; |
| 2483 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2484 | int num_meta_group_infos = |
| 2485 | (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >> |
| 2486 | EXT4_DESC_PER_BLOCK_BITS(sb); |
| 2487 | struct ext4_group_info **meta_group_info; |
| 2488 | |
| 2489 | /* An 8TB filesystem with 64-bit pointers requires a 4096 byte |
| 2490 | * kmalloc. A 128kb malloc should suffice for a 256TB filesystem. |
| 2491 | * So a two level scheme suffices for now. */ |
| 2492 | sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) * |
| 2493 | num_meta_group_infos, GFP_KERNEL); |
| 2494 | if (sbi->s_group_info == NULL) { |
| 2495 | printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n"); |
| 2496 | return -ENOMEM; |
| 2497 | } |
| 2498 | sbi->s_buddy_cache = new_inode(sb); |
| 2499 | if (sbi->s_buddy_cache == NULL) { |
| 2500 | printk(KERN_ERR "EXT4-fs: can't get new inode\n"); |
| 2501 | goto err_freesgi; |
| 2502 | } |
| 2503 | EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; |
| 2504 | |
| 2505 | metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb); |
| 2506 | for (i = 0; i < num_meta_group_infos; i++) { |
| 2507 | if ((i + 1) == num_meta_group_infos) |
| 2508 | metalen = sizeof(*meta_group_info) * |
| 2509 | (sbi->s_groups_count - |
| 2510 | (i << EXT4_DESC_PER_BLOCK_BITS(sb))); |
| 2511 | meta_group_info = kmalloc(metalen, GFP_KERNEL); |
| 2512 | if (meta_group_info == NULL) { |
| 2513 | printk(KERN_ERR "EXT4-fs: can't allocate mem for a " |
| 2514 | "buddy group\n"); |
| 2515 | goto err_freemeta; |
| 2516 | } |
| 2517 | sbi->s_group_info[i] = meta_group_info; |
| 2518 | } |
| 2519 | |
| 2520 | /* |
| 2521 | * calculate needed size. if change bb_counters size, |
| 2522 | * don't forget about ext4_mb_generate_buddy() |
| 2523 | */ |
| 2524 | len = sizeof(struct ext4_group_info); |
| 2525 | len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2); |
| 2526 | for (i = 0; i < sbi->s_groups_count; i++) { |
| 2527 | struct ext4_group_desc *desc; |
| 2528 | |
| 2529 | meta_group_info = |
| 2530 | sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)]; |
| 2531 | j = i & (EXT4_DESC_PER_BLOCK(sb) - 1); |
| 2532 | |
| 2533 | meta_group_info[j] = kzalloc(len, GFP_KERNEL); |
| 2534 | if (meta_group_info[j] == NULL) { |
| 2535 | printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n"); |
| 2536 | i--; |
| 2537 | goto err_freebuddy; |
| 2538 | } |
| 2539 | desc = ext4_get_group_desc(sb, i, NULL); |
| 2540 | if (desc == NULL) { |
| 2541 | printk(KERN_ERR |
| 2542 | "EXT4-fs: can't read descriptor %lu\n", i); |
| 2543 | goto err_freebuddy; |
| 2544 | } |
| 2545 | memset(meta_group_info[j], 0, len); |
| 2546 | set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, |
| 2547 | &(meta_group_info[j]->bb_state)); |
| 2548 | |
| 2549 | /* |
| 2550 | * initialize bb_free to be able to skip |
| 2551 | * empty groups without initialization |
| 2552 | */ |
| 2553 | if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
| 2554 | meta_group_info[j]->bb_free = |
| 2555 | ext4_free_blocks_after_init(sb, i, desc); |
| 2556 | } else { |
| 2557 | meta_group_info[j]->bb_free = |
| 2558 | le16_to_cpu(desc->bg_free_blocks_count); |
| 2559 | } |
| 2560 | |
| 2561 | INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list); |
| 2562 | |
| 2563 | #ifdef DOUBLE_CHECK |
| 2564 | { |
| 2565 | struct buffer_head *bh; |
| 2566 | meta_group_info[j]->bb_bitmap = |
| 2567 | kmalloc(sb->s_blocksize, GFP_KERNEL); |
| 2568 | BUG_ON(meta_group_info[j]->bb_bitmap == NULL); |
| 2569 | bh = read_block_bitmap(sb, i); |
| 2570 | BUG_ON(bh == NULL); |
| 2571 | memcpy(meta_group_info[j]->bb_bitmap, bh->b_data, |
| 2572 | sb->s_blocksize); |
| 2573 | put_bh(bh); |
| 2574 | } |
| 2575 | #endif |
| 2576 | |
| 2577 | } |
| 2578 | |
| 2579 | return 0; |
| 2580 | |
| 2581 | err_freebuddy: |
| 2582 | while (i >= 0) { |
| 2583 | kfree(ext4_get_group_info(sb, i)); |
| 2584 | i--; |
| 2585 | } |
| 2586 | i = num_meta_group_infos; |
| 2587 | err_freemeta: |
| 2588 | while (--i >= 0) |
| 2589 | kfree(sbi->s_group_info[i]); |
| 2590 | iput(sbi->s_buddy_cache); |
| 2591 | err_freesgi: |
| 2592 | kfree(sbi->s_group_info); |
| 2593 | return -ENOMEM; |
| 2594 | } |
| 2595 | |
| 2596 | int ext4_mb_init(struct super_block *sb, int needs_recovery) |
| 2597 | { |
| 2598 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2599 | unsigned i; |
| 2600 | unsigned offset; |
| 2601 | unsigned max; |
| 2602 | |
| 2603 | if (!test_opt(sb, MBALLOC)) |
| 2604 | return 0; |
| 2605 | |
| 2606 | i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short); |
| 2607 | |
| 2608 | sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL); |
| 2609 | if (sbi->s_mb_offsets == NULL) { |
| 2610 | clear_opt(sbi->s_mount_opt, MBALLOC); |
| 2611 | return -ENOMEM; |
| 2612 | } |
| 2613 | sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL); |
| 2614 | if (sbi->s_mb_maxs == NULL) { |
| 2615 | clear_opt(sbi->s_mount_opt, MBALLOC); |
| 2616 | kfree(sbi->s_mb_maxs); |
| 2617 | return -ENOMEM; |
| 2618 | } |
| 2619 | |
| 2620 | /* order 0 is regular bitmap */ |
| 2621 | sbi->s_mb_maxs[0] = sb->s_blocksize << 3; |
| 2622 | sbi->s_mb_offsets[0] = 0; |
| 2623 | |
| 2624 | i = 1; |
| 2625 | offset = 0; |
| 2626 | max = sb->s_blocksize << 2; |
| 2627 | do { |
| 2628 | sbi->s_mb_offsets[i] = offset; |
| 2629 | sbi->s_mb_maxs[i] = max; |
| 2630 | offset += 1 << (sb->s_blocksize_bits - i); |
| 2631 | max = max >> 1; |
| 2632 | i++; |
| 2633 | } while (i <= sb->s_blocksize_bits + 1); |
| 2634 | |
| 2635 | /* init file for buddy data */ |
| 2636 | i = ext4_mb_init_backend(sb); |
| 2637 | if (i) { |
| 2638 | clear_opt(sbi->s_mount_opt, MBALLOC); |
| 2639 | kfree(sbi->s_mb_offsets); |
| 2640 | kfree(sbi->s_mb_maxs); |
| 2641 | return i; |
| 2642 | } |
| 2643 | |
| 2644 | spin_lock_init(&sbi->s_md_lock); |
| 2645 | INIT_LIST_HEAD(&sbi->s_active_transaction); |
| 2646 | INIT_LIST_HEAD(&sbi->s_closed_transaction); |
| 2647 | INIT_LIST_HEAD(&sbi->s_committed_transaction); |
| 2648 | spin_lock_init(&sbi->s_bal_lock); |
| 2649 | |
| 2650 | sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; |
| 2651 | sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; |
| 2652 | sbi->s_mb_stats = MB_DEFAULT_STATS; |
| 2653 | sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD; |
| 2654 | sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; |
| 2655 | sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT; |
| 2656 | sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC; |
| 2657 | |
| 2658 | i = sizeof(struct ext4_locality_group) * NR_CPUS; |
| 2659 | sbi->s_locality_groups = kmalloc(i, GFP_KERNEL); |
| 2660 | if (sbi->s_locality_groups == NULL) { |
| 2661 | clear_opt(sbi->s_mount_opt, MBALLOC); |
| 2662 | kfree(sbi->s_mb_offsets); |
| 2663 | kfree(sbi->s_mb_maxs); |
| 2664 | return -ENOMEM; |
| 2665 | } |
| 2666 | for (i = 0; i < NR_CPUS; i++) { |
| 2667 | struct ext4_locality_group *lg; |
| 2668 | lg = &sbi->s_locality_groups[i]; |
| 2669 | mutex_init(&lg->lg_mutex); |
| 2670 | INIT_LIST_HEAD(&lg->lg_prealloc_list); |
| 2671 | spin_lock_init(&lg->lg_prealloc_lock); |
| 2672 | } |
| 2673 | |
| 2674 | ext4_mb_init_per_dev_proc(sb); |
| 2675 | ext4_mb_history_init(sb); |
| 2676 | |
| 2677 | printk("EXT4-fs: mballoc enabled\n"); |
| 2678 | return 0; |
| 2679 | } |
| 2680 | |
| 2681 | /* need to called with ext4 group lock (ext4_lock_group) */ |
| 2682 | static void ext4_mb_cleanup_pa(struct ext4_group_info *grp) |
| 2683 | { |
| 2684 | struct ext4_prealloc_space *pa; |
| 2685 | struct list_head *cur, *tmp; |
| 2686 | int count = 0; |
| 2687 | |
| 2688 | list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) { |
| 2689 | pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| 2690 | list_del(&pa->pa_group_list); |
| 2691 | count++; |
| 2692 | kfree(pa); |
| 2693 | } |
| 2694 | if (count) |
| 2695 | mb_debug("mballoc: %u PAs left\n", count); |
| 2696 | |
| 2697 | } |
| 2698 | |
| 2699 | int ext4_mb_release(struct super_block *sb) |
| 2700 | { |
| 2701 | ext4_group_t i; |
| 2702 | int num_meta_group_infos; |
| 2703 | struct ext4_group_info *grinfo; |
| 2704 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2705 | |
| 2706 | if (!test_opt(sb, MBALLOC)) |
| 2707 | return 0; |
| 2708 | |
| 2709 | /* release freed, non-committed blocks */ |
| 2710 | spin_lock(&sbi->s_md_lock); |
| 2711 | list_splice_init(&sbi->s_closed_transaction, |
| 2712 | &sbi->s_committed_transaction); |
| 2713 | list_splice_init(&sbi->s_active_transaction, |
| 2714 | &sbi->s_committed_transaction); |
| 2715 | spin_unlock(&sbi->s_md_lock); |
| 2716 | ext4_mb_free_committed_blocks(sb); |
| 2717 | |
| 2718 | if (sbi->s_group_info) { |
| 2719 | for (i = 0; i < sbi->s_groups_count; i++) { |
| 2720 | grinfo = ext4_get_group_info(sb, i); |
| 2721 | #ifdef DOUBLE_CHECK |
| 2722 | kfree(grinfo->bb_bitmap); |
| 2723 | #endif |
| 2724 | ext4_lock_group(sb, i); |
| 2725 | ext4_mb_cleanup_pa(grinfo); |
| 2726 | ext4_unlock_group(sb, i); |
| 2727 | kfree(grinfo); |
| 2728 | } |
| 2729 | num_meta_group_infos = (sbi->s_groups_count + |
| 2730 | EXT4_DESC_PER_BLOCK(sb) - 1) >> |
| 2731 | EXT4_DESC_PER_BLOCK_BITS(sb); |
| 2732 | for (i = 0; i < num_meta_group_infos; i++) |
| 2733 | kfree(sbi->s_group_info[i]); |
| 2734 | kfree(sbi->s_group_info); |
| 2735 | } |
| 2736 | kfree(sbi->s_mb_offsets); |
| 2737 | kfree(sbi->s_mb_maxs); |
| 2738 | if (sbi->s_buddy_cache) |
| 2739 | iput(sbi->s_buddy_cache); |
| 2740 | if (sbi->s_mb_stats) { |
| 2741 | printk(KERN_INFO |
| 2742 | "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n", |
| 2743 | atomic_read(&sbi->s_bal_allocated), |
| 2744 | atomic_read(&sbi->s_bal_reqs), |
| 2745 | atomic_read(&sbi->s_bal_success)); |
| 2746 | printk(KERN_INFO |
| 2747 | "EXT4-fs: mballoc: %u extents scanned, %u goal hits, " |
| 2748 | "%u 2^N hits, %u breaks, %u lost\n", |
| 2749 | atomic_read(&sbi->s_bal_ex_scanned), |
| 2750 | atomic_read(&sbi->s_bal_goals), |
| 2751 | atomic_read(&sbi->s_bal_2orders), |
| 2752 | atomic_read(&sbi->s_bal_breaks), |
| 2753 | atomic_read(&sbi->s_mb_lost_chunks)); |
| 2754 | printk(KERN_INFO |
| 2755 | "EXT4-fs: mballoc: %lu generated and it took %Lu\n", |
| 2756 | sbi->s_mb_buddies_generated++, |
| 2757 | sbi->s_mb_generation_time); |
| 2758 | printk(KERN_INFO |
| 2759 | "EXT4-fs: mballoc: %u preallocated, %u discarded\n", |
| 2760 | atomic_read(&sbi->s_mb_preallocated), |
| 2761 | atomic_read(&sbi->s_mb_discarded)); |
| 2762 | } |
| 2763 | |
| 2764 | kfree(sbi->s_locality_groups); |
| 2765 | |
| 2766 | ext4_mb_history_release(sb); |
| 2767 | ext4_mb_destroy_per_dev_proc(sb); |
| 2768 | |
| 2769 | return 0; |
| 2770 | } |
| 2771 | |
| 2772 | static void ext4_mb_free_committed_blocks(struct super_block *sb) |
| 2773 | { |
| 2774 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2775 | int err; |
| 2776 | int i; |
| 2777 | int count = 0; |
| 2778 | int count2 = 0; |
| 2779 | struct ext4_free_metadata *md; |
| 2780 | struct ext4_buddy e4b; |
| 2781 | |
| 2782 | if (list_empty(&sbi->s_committed_transaction)) |
| 2783 | return; |
| 2784 | |
| 2785 | /* there is committed blocks to be freed yet */ |
| 2786 | do { |
| 2787 | /* get next array of blocks */ |
| 2788 | md = NULL; |
| 2789 | spin_lock(&sbi->s_md_lock); |
| 2790 | if (!list_empty(&sbi->s_committed_transaction)) { |
| 2791 | md = list_entry(sbi->s_committed_transaction.next, |
| 2792 | struct ext4_free_metadata, list); |
| 2793 | list_del(&md->list); |
| 2794 | } |
| 2795 | spin_unlock(&sbi->s_md_lock); |
| 2796 | |
| 2797 | if (md == NULL) |
| 2798 | break; |
| 2799 | |
| 2800 | mb_debug("gonna free %u blocks in group %lu (0x%p):", |
| 2801 | md->num, md->group, md); |
| 2802 | |
| 2803 | err = ext4_mb_load_buddy(sb, md->group, &e4b); |
| 2804 | /* we expect to find existing buddy because it's pinned */ |
| 2805 | BUG_ON(err != 0); |
| 2806 | |
| 2807 | /* there are blocks to put in buddy to make them really free */ |
| 2808 | count += md->num; |
| 2809 | count2++; |
| 2810 | ext4_lock_group(sb, md->group); |
| 2811 | for (i = 0; i < md->num; i++) { |
| 2812 | mb_debug(" %u", md->blocks[i]); |
| 2813 | err = mb_free_blocks(NULL, &e4b, md->blocks[i], 1); |
| 2814 | BUG_ON(err != 0); |
| 2815 | } |
| 2816 | mb_debug("\n"); |
| 2817 | ext4_unlock_group(sb, md->group); |
| 2818 | |
| 2819 | /* balance refcounts from ext4_mb_free_metadata() */ |
| 2820 | page_cache_release(e4b.bd_buddy_page); |
| 2821 | page_cache_release(e4b.bd_bitmap_page); |
| 2822 | |
| 2823 | kfree(md); |
| 2824 | ext4_mb_release_desc(&e4b); |
| 2825 | |
| 2826 | } while (md); |
| 2827 | |
| 2828 | mb_debug("freed %u blocks in %u structures\n", count, count2); |
| 2829 | } |
| 2830 | |
| 2831 | #define EXT4_ROOT "ext4" |
| 2832 | #define EXT4_MB_STATS_NAME "stats" |
| 2833 | #define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan" |
| 2834 | #define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan" |
| 2835 | #define EXT4_MB_ORDER2_REQ "order2_req" |
| 2836 | #define EXT4_MB_STREAM_REQ "stream_req" |
| 2837 | #define EXT4_MB_GROUP_PREALLOC "group_prealloc" |
| 2838 | |
| 2839 | |
| 2840 | |
| 2841 | #define MB_PROC_VALUE_READ(name) \ |
| 2842 | static int ext4_mb_read_##name(char *page, char **start, \ |
| 2843 | off_t off, int count, int *eof, void *data) \ |
| 2844 | { \ |
| 2845 | struct ext4_sb_info *sbi = data; \ |
| 2846 | int len; \ |
| 2847 | *eof = 1; \ |
| 2848 | if (off != 0) \ |
| 2849 | return 0; \ |
| 2850 | len = sprintf(page, "%ld\n", sbi->s_mb_##name); \ |
| 2851 | *start = page; \ |
| 2852 | return len; \ |
| 2853 | } |
| 2854 | |
| 2855 | #define MB_PROC_VALUE_WRITE(name) \ |
| 2856 | static int ext4_mb_write_##name(struct file *file, \ |
| 2857 | const char __user *buf, unsigned long cnt, void *data) \ |
| 2858 | { \ |
| 2859 | struct ext4_sb_info *sbi = data; \ |
| 2860 | char str[32]; \ |
| 2861 | long value; \ |
| 2862 | if (cnt >= sizeof(str)) \ |
| 2863 | return -EINVAL; \ |
| 2864 | if (copy_from_user(str, buf, cnt)) \ |
| 2865 | return -EFAULT; \ |
| 2866 | value = simple_strtol(str, NULL, 0); \ |
| 2867 | if (value <= 0) \ |
| 2868 | return -ERANGE; \ |
| 2869 | sbi->s_mb_##name = value; \ |
| 2870 | return cnt; \ |
| 2871 | } |
| 2872 | |
| 2873 | MB_PROC_VALUE_READ(stats); |
| 2874 | MB_PROC_VALUE_WRITE(stats); |
| 2875 | MB_PROC_VALUE_READ(max_to_scan); |
| 2876 | MB_PROC_VALUE_WRITE(max_to_scan); |
| 2877 | MB_PROC_VALUE_READ(min_to_scan); |
| 2878 | MB_PROC_VALUE_WRITE(min_to_scan); |
| 2879 | MB_PROC_VALUE_READ(order2_reqs); |
| 2880 | MB_PROC_VALUE_WRITE(order2_reqs); |
| 2881 | MB_PROC_VALUE_READ(stream_request); |
| 2882 | MB_PROC_VALUE_WRITE(stream_request); |
| 2883 | MB_PROC_VALUE_READ(group_prealloc); |
| 2884 | MB_PROC_VALUE_WRITE(group_prealloc); |
| 2885 | |
| 2886 | #define MB_PROC_HANDLER(name, var) \ |
| 2887 | do { \ |
| 2888 | proc = create_proc_entry(name, mode, sbi->s_mb_proc); \ |
| 2889 | if (proc == NULL) { \ |
| 2890 | printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \ |
| 2891 | goto err_out; \ |
| 2892 | } \ |
| 2893 | proc->data = sbi; \ |
| 2894 | proc->read_proc = ext4_mb_read_##var ; \ |
| 2895 | proc->write_proc = ext4_mb_write_##var; \ |
| 2896 | } while (0) |
| 2897 | |
| 2898 | static int ext4_mb_init_per_dev_proc(struct super_block *sb) |
| 2899 | { |
| 2900 | mode_t mode = S_IFREG | S_IRUGO | S_IWUSR; |
| 2901 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2902 | struct proc_dir_entry *proc; |
| 2903 | char devname[64]; |
| 2904 | |
| 2905 | snprintf(devname, sizeof(devname) - 1, "%s", |
| 2906 | bdevname(sb->s_bdev, devname)); |
| 2907 | sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4); |
| 2908 | |
| 2909 | MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats); |
| 2910 | MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan); |
| 2911 | MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, min_to_scan); |
| 2912 | MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ, order2_reqs); |
| 2913 | MB_PROC_HANDLER(EXT4_MB_STREAM_REQ, stream_request); |
| 2914 | MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, group_prealloc); |
| 2915 | |
| 2916 | return 0; |
| 2917 | |
| 2918 | err_out: |
| 2919 | printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname); |
| 2920 | remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc); |
| 2921 | remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc); |
| 2922 | remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc); |
| 2923 | remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc); |
| 2924 | remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc); |
| 2925 | remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc); |
| 2926 | remove_proc_entry(devname, proc_root_ext4); |
| 2927 | sbi->s_mb_proc = NULL; |
| 2928 | |
| 2929 | return -ENOMEM; |
| 2930 | } |
| 2931 | |
| 2932 | static int ext4_mb_destroy_per_dev_proc(struct super_block *sb) |
| 2933 | { |
| 2934 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 2935 | char devname[64]; |
| 2936 | |
| 2937 | if (sbi->s_mb_proc == NULL) |
| 2938 | return -EINVAL; |
| 2939 | |
| 2940 | snprintf(devname, sizeof(devname) - 1, "%s", |
| 2941 | bdevname(sb->s_bdev, devname)); |
| 2942 | remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc); |
| 2943 | remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc); |
| 2944 | remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc); |
| 2945 | remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc); |
| 2946 | remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc); |
| 2947 | remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc); |
| 2948 | remove_proc_entry(devname, proc_root_ext4); |
| 2949 | |
| 2950 | return 0; |
| 2951 | } |
| 2952 | |
| 2953 | int __init init_ext4_mballoc(void) |
| 2954 | { |
| 2955 | ext4_pspace_cachep = |
| 2956 | kmem_cache_create("ext4_prealloc_space", |
| 2957 | sizeof(struct ext4_prealloc_space), |
| 2958 | 0, SLAB_RECLAIM_ACCOUNT, NULL); |
| 2959 | if (ext4_pspace_cachep == NULL) |
| 2960 | return -ENOMEM; |
| 2961 | |
| 2962 | #ifdef CONFIG_PROC_FS |
| 2963 | proc_root_ext4 = proc_mkdir(EXT4_ROOT, proc_root_fs); |
| 2964 | if (proc_root_ext4 == NULL) |
| 2965 | printk(KERN_ERR "EXT4-fs: Unable to create %s\n", EXT4_ROOT); |
| 2966 | #endif |
| 2967 | |
| 2968 | return 0; |
| 2969 | } |
| 2970 | |
| 2971 | void exit_ext4_mballoc(void) |
| 2972 | { |
| 2973 | /* XXX: synchronize_rcu(); */ |
| 2974 | kmem_cache_destroy(ext4_pspace_cachep); |
| 2975 | #ifdef CONFIG_PROC_FS |
| 2976 | remove_proc_entry(EXT4_ROOT, proc_root_fs); |
| 2977 | #endif |
| 2978 | } |
| 2979 | |
| 2980 | |
| 2981 | /* |
| 2982 | * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps |
| 2983 | * Returns 0 if success or error code |
| 2984 | */ |
| 2985 | static int ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, |
| 2986 | handle_t *handle) |
| 2987 | { |
| 2988 | struct buffer_head *bitmap_bh = NULL; |
| 2989 | struct ext4_super_block *es; |
| 2990 | struct ext4_group_desc *gdp; |
| 2991 | struct buffer_head *gdp_bh; |
| 2992 | struct ext4_sb_info *sbi; |
| 2993 | struct super_block *sb; |
| 2994 | ext4_fsblk_t block; |
| 2995 | int err; |
| 2996 | |
| 2997 | BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| 2998 | BUG_ON(ac->ac_b_ex.fe_len <= 0); |
| 2999 | |
| 3000 | sb = ac->ac_sb; |
| 3001 | sbi = EXT4_SB(sb); |
| 3002 | es = sbi->s_es; |
| 3003 | |
| 3004 | ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group, |
| 3005 | gdp->bg_free_blocks_count); |
| 3006 | |
| 3007 | err = -EIO; |
| 3008 | bitmap_bh = read_block_bitmap(sb, ac->ac_b_ex.fe_group); |
| 3009 | if (!bitmap_bh) |
| 3010 | goto out_err; |
| 3011 | |
| 3012 | err = ext4_journal_get_write_access(handle, bitmap_bh); |
| 3013 | if (err) |
| 3014 | goto out_err; |
| 3015 | |
| 3016 | err = -EIO; |
| 3017 | gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh); |
| 3018 | if (!gdp) |
| 3019 | goto out_err; |
| 3020 | |
| 3021 | err = ext4_journal_get_write_access(handle, gdp_bh); |
| 3022 | if (err) |
| 3023 | goto out_err; |
| 3024 | |
| 3025 | block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb) |
| 3026 | + ac->ac_b_ex.fe_start |
| 3027 | + le32_to_cpu(es->s_first_data_block); |
| 3028 | |
| 3029 | if (block == ext4_block_bitmap(sb, gdp) || |
| 3030 | block == ext4_inode_bitmap(sb, gdp) || |
| 3031 | in_range(block, ext4_inode_table(sb, gdp), |
| 3032 | EXT4_SB(sb)->s_itb_per_group)) { |
| 3033 | |
| 3034 | ext4_error(sb, __FUNCTION__, |
| 3035 | "Allocating block in system zone - block = %llu", |
| 3036 | block); |
| 3037 | } |
| 3038 | #ifdef AGGRESSIVE_CHECK |
| 3039 | { |
| 3040 | int i; |
| 3041 | for (i = 0; i < ac->ac_b_ex.fe_len; i++) { |
| 3042 | BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i, |
| 3043 | bitmap_bh->b_data)); |
| 3044 | } |
| 3045 | } |
| 3046 | #endif |
| 3047 | mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data, |
| 3048 | ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len); |
| 3049 | |
| 3050 | spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group)); |
| 3051 | if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
| 3052 | gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); |
| 3053 | gdp->bg_free_blocks_count = |
| 3054 | cpu_to_le16(ext4_free_blocks_after_init(sb, |
| 3055 | ac->ac_b_ex.fe_group, |
| 3056 | gdp)); |
| 3057 | } |
| 3058 | gdp->bg_free_blocks_count = |
| 3059 | cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) |
| 3060 | - ac->ac_b_ex.fe_len); |
| 3061 | gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp); |
| 3062 | spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group)); |
| 3063 | percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len); |
| 3064 | |
| 3065 | err = ext4_journal_dirty_metadata(handle, bitmap_bh); |
| 3066 | if (err) |
| 3067 | goto out_err; |
| 3068 | err = ext4_journal_dirty_metadata(handle, gdp_bh); |
| 3069 | |
| 3070 | out_err: |
| 3071 | sb->s_dirt = 1; |
| 3072 | put_bh(bitmap_bh); |
| 3073 | return err; |
| 3074 | } |
| 3075 | |
| 3076 | /* |
| 3077 | * here we normalize request for locality group |
| 3078 | * Group request are normalized to s_strip size if we set the same via mount |
| 3079 | * option. If not we set it to s_mb_group_prealloc which can be configured via |
| 3080 | * /proc/fs/ext4/<partition>/group_prealloc |
| 3081 | * |
| 3082 | * XXX: should we try to preallocate more than the group has now? |
| 3083 | */ |
| 3084 | static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) |
| 3085 | { |
| 3086 | struct super_block *sb = ac->ac_sb; |
| 3087 | struct ext4_locality_group *lg = ac->ac_lg; |
| 3088 | |
| 3089 | BUG_ON(lg == NULL); |
| 3090 | if (EXT4_SB(sb)->s_stripe) |
| 3091 | ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe; |
| 3092 | else |
| 3093 | ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; |
| 3094 | mb_debug("#%u: goal %lu blocks for locality group\n", |
| 3095 | current->pid, ac->ac_g_ex.fe_len); |
| 3096 | } |
| 3097 | |
| 3098 | /* |
| 3099 | * Normalization means making request better in terms of |
| 3100 | * size and alignment |
| 3101 | */ |
| 3102 | static void ext4_mb_normalize_request(struct ext4_allocation_context *ac, |
| 3103 | struct ext4_allocation_request *ar) |
| 3104 | { |
| 3105 | int bsbits, max; |
| 3106 | ext4_lblk_t end; |
| 3107 | struct list_head *cur; |
| 3108 | loff_t size, orig_size, start_off; |
| 3109 | ext4_lblk_t start, orig_start; |
| 3110 | struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| 3111 | |
| 3112 | /* do normalize only data requests, metadata requests |
| 3113 | do not need preallocation */ |
| 3114 | if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| 3115 | return; |
| 3116 | |
| 3117 | /* sometime caller may want exact blocks */ |
| 3118 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| 3119 | return; |
| 3120 | |
| 3121 | /* caller may indicate that preallocation isn't |
| 3122 | * required (it's a tail, for example) */ |
| 3123 | if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC) |
| 3124 | return; |
| 3125 | |
| 3126 | if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) { |
| 3127 | ext4_mb_normalize_group_request(ac); |
| 3128 | return ; |
| 3129 | } |
| 3130 | |
| 3131 | bsbits = ac->ac_sb->s_blocksize_bits; |
| 3132 | |
| 3133 | /* first, let's learn actual file size |
| 3134 | * given current request is allocated */ |
| 3135 | size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; |
| 3136 | size = size << bsbits; |
| 3137 | if (size < i_size_read(ac->ac_inode)) |
| 3138 | size = i_size_read(ac->ac_inode); |
| 3139 | |
| 3140 | /* max available blocks in a free group */ |
| 3141 | max = EXT4_BLOCKS_PER_GROUP(ac->ac_sb) - 1 - 1 - |
| 3142 | EXT4_SB(ac->ac_sb)->s_itb_per_group; |
| 3143 | |
| 3144 | #define NRL_CHECK_SIZE(req, size, max,bits) \ |
| 3145 | (req <= (size) || max <= ((size) >> bits)) |
| 3146 | |
| 3147 | /* first, try to predict filesize */ |
| 3148 | /* XXX: should this table be tunable? */ |
| 3149 | start_off = 0; |
| 3150 | if (size <= 16 * 1024) { |
| 3151 | size = 16 * 1024; |
| 3152 | } else if (size <= 32 * 1024) { |
| 3153 | size = 32 * 1024; |
| 3154 | } else if (size <= 64 * 1024) { |
| 3155 | size = 64 * 1024; |
| 3156 | } else if (size <= 128 * 1024) { |
| 3157 | size = 128 * 1024; |
| 3158 | } else if (size <= 256 * 1024) { |
| 3159 | size = 256 * 1024; |
| 3160 | } else if (size <= 512 * 1024) { |
| 3161 | size = 512 * 1024; |
| 3162 | } else if (size <= 1024 * 1024) { |
| 3163 | size = 1024 * 1024; |
| 3164 | } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, bsbits)) { |
| 3165 | start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| 3166 | (20 - bsbits)) << 20; |
| 3167 | size = 1024 * 1024; |
| 3168 | } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, bsbits)) { |
| 3169 | start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| 3170 | (22 - bsbits)) << 22; |
| 3171 | size = 4 * 1024 * 1024; |
| 3172 | } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len, |
| 3173 | (8<<20)>>bsbits, max, bsbits)) { |
| 3174 | start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| 3175 | (23 - bsbits)) << 23; |
| 3176 | size = 8 * 1024 * 1024; |
| 3177 | } else { |
| 3178 | start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits; |
| 3179 | size = ac->ac_o_ex.fe_len << bsbits; |
| 3180 | } |
| 3181 | orig_size = size = size >> bsbits; |
| 3182 | orig_start = start = start_off >> bsbits; |
| 3183 | |
| 3184 | /* don't cover already allocated blocks in selected range */ |
| 3185 | if (ar->pleft && start <= ar->lleft) { |
| 3186 | size -= ar->lleft + 1 - start; |
| 3187 | start = ar->lleft + 1; |
| 3188 | } |
| 3189 | if (ar->pright && start + size - 1 >= ar->lright) |
| 3190 | size -= start + size - ar->lright; |
| 3191 | |
| 3192 | end = start + size; |
| 3193 | |
| 3194 | /* check we don't cross already preallocated blocks */ |
| 3195 | rcu_read_lock(); |
| 3196 | list_for_each_rcu(cur, &ei->i_prealloc_list) { |
| 3197 | struct ext4_prealloc_space *pa; |
| 3198 | unsigned long pa_end; |
| 3199 | |
| 3200 | pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list); |
| 3201 | |
| 3202 | if (pa->pa_deleted) |
| 3203 | continue; |
| 3204 | spin_lock(&pa->pa_lock); |
| 3205 | if (pa->pa_deleted) { |
| 3206 | spin_unlock(&pa->pa_lock); |
| 3207 | continue; |
| 3208 | } |
| 3209 | |
| 3210 | pa_end = pa->pa_lstart + pa->pa_len; |
| 3211 | |
| 3212 | /* PA must not overlap original request */ |
| 3213 | BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end || |
| 3214 | ac->ac_o_ex.fe_logical < pa->pa_lstart)); |
| 3215 | |
| 3216 | /* skip PA normalized request doesn't overlap with */ |
| 3217 | if (pa->pa_lstart >= end) { |
| 3218 | spin_unlock(&pa->pa_lock); |
| 3219 | continue; |
| 3220 | } |
| 3221 | if (pa_end <= start) { |
| 3222 | spin_unlock(&pa->pa_lock); |
| 3223 | continue; |
| 3224 | } |
| 3225 | BUG_ON(pa->pa_lstart <= start && pa_end >= end); |
| 3226 | |
| 3227 | if (pa_end <= ac->ac_o_ex.fe_logical) { |
| 3228 | BUG_ON(pa_end < start); |
| 3229 | start = pa_end; |
| 3230 | } |
| 3231 | |
| 3232 | if (pa->pa_lstart > ac->ac_o_ex.fe_logical) { |
| 3233 | BUG_ON(pa->pa_lstart > end); |
| 3234 | end = pa->pa_lstart; |
| 3235 | } |
| 3236 | spin_unlock(&pa->pa_lock); |
| 3237 | } |
| 3238 | rcu_read_unlock(); |
| 3239 | size = end - start; |
| 3240 | |
| 3241 | /* XXX: extra loop to check we really don't overlap preallocations */ |
| 3242 | rcu_read_lock(); |
| 3243 | list_for_each_rcu(cur, &ei->i_prealloc_list) { |
| 3244 | struct ext4_prealloc_space *pa; |
| 3245 | unsigned long pa_end; |
| 3246 | pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list); |
| 3247 | spin_lock(&pa->pa_lock); |
| 3248 | if (pa->pa_deleted == 0) { |
| 3249 | pa_end = pa->pa_lstart + pa->pa_len; |
| 3250 | BUG_ON(!(start >= pa_end || end <= pa->pa_lstart)); |
| 3251 | } |
| 3252 | spin_unlock(&pa->pa_lock); |
| 3253 | } |
| 3254 | rcu_read_unlock(); |
| 3255 | |
| 3256 | if (start + size <= ac->ac_o_ex.fe_logical && |
| 3257 | start > ac->ac_o_ex.fe_logical) { |
| 3258 | printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n", |
| 3259 | (unsigned long) start, (unsigned long) size, |
| 3260 | (unsigned long) ac->ac_o_ex.fe_logical); |
| 3261 | } |
| 3262 | BUG_ON(start + size <= ac->ac_o_ex.fe_logical && |
| 3263 | start > ac->ac_o_ex.fe_logical); |
| 3264 | BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
| 3265 | |
| 3266 | /* now prepare goal request */ |
| 3267 | |
| 3268 | /* XXX: is it better to align blocks WRT to logical |
| 3269 | * placement or satisfy big request as is */ |
| 3270 | ac->ac_g_ex.fe_logical = start; |
| 3271 | ac->ac_g_ex.fe_len = size; |
| 3272 | |
| 3273 | /* define goal start in order to merge */ |
| 3274 | if (ar->pright && (ar->lright == (start + size))) { |
| 3275 | /* merge to the right */ |
| 3276 | ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size, |
| 3277 | &ac->ac_f_ex.fe_group, |
| 3278 | &ac->ac_f_ex.fe_start); |
| 3279 | ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
| 3280 | } |
| 3281 | if (ar->pleft && (ar->lleft + 1 == start)) { |
| 3282 | /* merge to the left */ |
| 3283 | ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1, |
| 3284 | &ac->ac_f_ex.fe_group, |
| 3285 | &ac->ac_f_ex.fe_start); |
| 3286 | ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
| 3287 | } |
| 3288 | |
| 3289 | mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size, |
| 3290 | (unsigned) orig_size, (unsigned) start); |
| 3291 | } |
| 3292 | |
| 3293 | static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) |
| 3294 | { |
| 3295 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| 3296 | |
| 3297 | if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) { |
| 3298 | atomic_inc(&sbi->s_bal_reqs); |
| 3299 | atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); |
| 3300 | if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len) |
| 3301 | atomic_inc(&sbi->s_bal_success); |
| 3302 | atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); |
| 3303 | if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && |
| 3304 | ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) |
| 3305 | atomic_inc(&sbi->s_bal_goals); |
| 3306 | if (ac->ac_found > sbi->s_mb_max_to_scan) |
| 3307 | atomic_inc(&sbi->s_bal_breaks); |
| 3308 | } |
| 3309 | |
| 3310 | ext4_mb_store_history(ac); |
| 3311 | } |
| 3312 | |
| 3313 | /* |
| 3314 | * use blocks preallocated to inode |
| 3315 | */ |
| 3316 | static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac, |
| 3317 | struct ext4_prealloc_space *pa) |
| 3318 | { |
| 3319 | ext4_fsblk_t start; |
| 3320 | ext4_fsblk_t end; |
| 3321 | int len; |
| 3322 | |
| 3323 | /* found preallocated blocks, use them */ |
| 3324 | start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart); |
| 3325 | end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len); |
| 3326 | len = end - start; |
| 3327 | ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group, |
| 3328 | &ac->ac_b_ex.fe_start); |
| 3329 | ac->ac_b_ex.fe_len = len; |
| 3330 | ac->ac_status = AC_STATUS_FOUND; |
| 3331 | ac->ac_pa = pa; |
| 3332 | |
| 3333 | BUG_ON(start < pa->pa_pstart); |
| 3334 | BUG_ON(start + len > pa->pa_pstart + pa->pa_len); |
| 3335 | BUG_ON(pa->pa_free < len); |
| 3336 | pa->pa_free -= len; |
| 3337 | |
| 3338 | mb_debug("use %llu/%lu from inode pa %p\n", start, len, pa); |
| 3339 | } |
| 3340 | |
| 3341 | /* |
| 3342 | * use blocks preallocated to locality group |
| 3343 | */ |
| 3344 | static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, |
| 3345 | struct ext4_prealloc_space *pa) |
| 3346 | { |
| 3347 | unsigned len = ac->ac_o_ex.fe_len; |
| 3348 | |
| 3349 | ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart, |
| 3350 | &ac->ac_b_ex.fe_group, |
| 3351 | &ac->ac_b_ex.fe_start); |
| 3352 | ac->ac_b_ex.fe_len = len; |
| 3353 | ac->ac_status = AC_STATUS_FOUND; |
| 3354 | ac->ac_pa = pa; |
| 3355 | |
| 3356 | /* we don't correct pa_pstart or pa_plen here to avoid |
| 3357 | * possible race when tte group is being loaded concurrently |
| 3358 | * instead we correct pa later, after blocks are marked |
| 3359 | * in on-disk bitmap -- see ext4_mb_release_context() */ |
| 3360 | /* |
| 3361 | * FIXME!! but the other CPUs can look at this particular |
| 3362 | * pa and think that it have enought free blocks if we |
| 3363 | * don't update pa_free here right ? |
| 3364 | */ |
| 3365 | mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa); |
| 3366 | } |
| 3367 | |
| 3368 | /* |
| 3369 | * search goal blocks in preallocated space |
| 3370 | */ |
| 3371 | static int ext4_mb_use_preallocated(struct ext4_allocation_context *ac) |
| 3372 | { |
| 3373 | struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| 3374 | struct ext4_locality_group *lg; |
| 3375 | struct ext4_prealloc_space *pa; |
| 3376 | struct list_head *cur; |
| 3377 | |
| 3378 | /* only data can be preallocated */ |
| 3379 | if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| 3380 | return 0; |
| 3381 | |
| 3382 | /* first, try per-file preallocation */ |
| 3383 | rcu_read_lock(); |
| 3384 | list_for_each_rcu(cur, &ei->i_prealloc_list) { |
| 3385 | pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list); |
| 3386 | |
| 3387 | /* all fields in this condition don't change, |
| 3388 | * so we can skip locking for them */ |
| 3389 | if (ac->ac_o_ex.fe_logical < pa->pa_lstart || |
| 3390 | ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len) |
| 3391 | continue; |
| 3392 | |
| 3393 | /* found preallocated blocks, use them */ |
| 3394 | spin_lock(&pa->pa_lock); |
| 3395 | if (pa->pa_deleted == 0 && pa->pa_free) { |
| 3396 | atomic_inc(&pa->pa_count); |
| 3397 | ext4_mb_use_inode_pa(ac, pa); |
| 3398 | spin_unlock(&pa->pa_lock); |
| 3399 | ac->ac_criteria = 10; |
| 3400 | rcu_read_unlock(); |
| 3401 | return 1; |
| 3402 | } |
| 3403 | spin_unlock(&pa->pa_lock); |
| 3404 | } |
| 3405 | rcu_read_unlock(); |
| 3406 | |
| 3407 | /* can we use group allocation? */ |
| 3408 | if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)) |
| 3409 | return 0; |
| 3410 | |
| 3411 | /* inode may have no locality group for some reason */ |
| 3412 | lg = ac->ac_lg; |
| 3413 | if (lg == NULL) |
| 3414 | return 0; |
| 3415 | |
| 3416 | rcu_read_lock(); |
| 3417 | list_for_each_rcu(cur, &lg->lg_prealloc_list) { |
| 3418 | pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list); |
| 3419 | spin_lock(&pa->pa_lock); |
| 3420 | if (pa->pa_deleted == 0 && pa->pa_free >= ac->ac_o_ex.fe_len) { |
| 3421 | atomic_inc(&pa->pa_count); |
| 3422 | ext4_mb_use_group_pa(ac, pa); |
| 3423 | spin_unlock(&pa->pa_lock); |
| 3424 | ac->ac_criteria = 20; |
| 3425 | rcu_read_unlock(); |
| 3426 | return 1; |
| 3427 | } |
| 3428 | spin_unlock(&pa->pa_lock); |
| 3429 | } |
| 3430 | rcu_read_unlock(); |
| 3431 | |
| 3432 | return 0; |
| 3433 | } |
| 3434 | |
| 3435 | /* |
| 3436 | * the function goes through all preallocation in this group and marks them |
| 3437 | * used in in-core bitmap. buddy must be generated from this bitmap |
| 3438 | * Need to be called with ext4 group lock (ext4_lock_group) |
| 3439 | */ |
| 3440 | static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, |
| 3441 | ext4_group_t group) |
| 3442 | { |
| 3443 | struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| 3444 | struct ext4_prealloc_space *pa; |
| 3445 | struct list_head *cur; |
| 3446 | ext4_group_t groupnr; |
| 3447 | ext4_grpblk_t start; |
| 3448 | int preallocated = 0; |
| 3449 | int count = 0; |
| 3450 | int len; |
| 3451 | |
| 3452 | /* all form of preallocation discards first load group, |
| 3453 | * so the only competing code is preallocation use. |
| 3454 | * we don't need any locking here |
| 3455 | * notice we do NOT ignore preallocations with pa_deleted |
| 3456 | * otherwise we could leave used blocks available for |
| 3457 | * allocation in buddy when concurrent ext4_mb_put_pa() |
| 3458 | * is dropping preallocation |
| 3459 | */ |
| 3460 | list_for_each(cur, &grp->bb_prealloc_list) { |
| 3461 | pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| 3462 | spin_lock(&pa->pa_lock); |
| 3463 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
| 3464 | &groupnr, &start); |
| 3465 | len = pa->pa_len; |
| 3466 | spin_unlock(&pa->pa_lock); |
| 3467 | if (unlikely(len == 0)) |
| 3468 | continue; |
| 3469 | BUG_ON(groupnr != group); |
| 3470 | mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group), |
| 3471 | bitmap, start, len); |
| 3472 | preallocated += len; |
| 3473 | count++; |
| 3474 | } |
| 3475 | mb_debug("prellocated %u for group %lu\n", preallocated, group); |
| 3476 | } |
| 3477 | |
| 3478 | static void ext4_mb_pa_callback(struct rcu_head *head) |
| 3479 | { |
| 3480 | struct ext4_prealloc_space *pa; |
| 3481 | pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu); |
| 3482 | kmem_cache_free(ext4_pspace_cachep, pa); |
| 3483 | } |
| 3484 | |
| 3485 | /* |
| 3486 | * drops a reference to preallocated space descriptor |
| 3487 | * if this was the last reference and the space is consumed |
| 3488 | */ |
| 3489 | static void ext4_mb_put_pa(struct ext4_allocation_context *ac, |
| 3490 | struct super_block *sb, struct ext4_prealloc_space *pa) |
| 3491 | { |
| 3492 | unsigned long grp; |
| 3493 | |
| 3494 | if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) |
| 3495 | return; |
| 3496 | |
| 3497 | /* in this short window concurrent discard can set pa_deleted */ |
| 3498 | spin_lock(&pa->pa_lock); |
| 3499 | if (pa->pa_deleted == 1) { |
| 3500 | spin_unlock(&pa->pa_lock); |
| 3501 | return; |
| 3502 | } |
| 3503 | |
| 3504 | pa->pa_deleted = 1; |
| 3505 | spin_unlock(&pa->pa_lock); |
| 3506 | |
| 3507 | /* -1 is to protect from crossing allocation group */ |
| 3508 | ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL); |
| 3509 | |
| 3510 | /* |
| 3511 | * possible race: |
| 3512 | * |
| 3513 | * P1 (buddy init) P2 (regular allocation) |
| 3514 | * find block B in PA |
| 3515 | * copy on-disk bitmap to buddy |
| 3516 | * mark B in on-disk bitmap |
| 3517 | * drop PA from group |
| 3518 | * mark all PAs in buddy |
| 3519 | * |
| 3520 | * thus, P1 initializes buddy with B available. to prevent this |
| 3521 | * we make "copy" and "mark all PAs" atomic and serialize "drop PA" |
| 3522 | * against that pair |
| 3523 | */ |
| 3524 | ext4_lock_group(sb, grp); |
| 3525 | list_del(&pa->pa_group_list); |
| 3526 | ext4_unlock_group(sb, grp); |
| 3527 | |
| 3528 | spin_lock(pa->pa_obj_lock); |
| 3529 | list_del_rcu(&pa->pa_inode_list); |
| 3530 | spin_unlock(pa->pa_obj_lock); |
| 3531 | |
| 3532 | call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| 3533 | } |
| 3534 | |
| 3535 | /* |
| 3536 | * creates new preallocated space for given inode |
| 3537 | */ |
| 3538 | static int ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) |
| 3539 | { |
| 3540 | struct super_block *sb = ac->ac_sb; |
| 3541 | struct ext4_prealloc_space *pa; |
| 3542 | struct ext4_group_info *grp; |
| 3543 | struct ext4_inode_info *ei; |
| 3544 | |
| 3545 | /* preallocate only when found space is larger then requested */ |
| 3546 | BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
| 3547 | BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| 3548 | BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
| 3549 | |
| 3550 | pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); |
| 3551 | if (pa == NULL) |
| 3552 | return -ENOMEM; |
| 3553 | |
| 3554 | if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) { |
| 3555 | int winl; |
| 3556 | int wins; |
| 3557 | int win; |
| 3558 | int offs; |
| 3559 | |
| 3560 | /* we can't allocate as much as normalizer wants. |
| 3561 | * so, found space must get proper lstart |
| 3562 | * to cover original request */ |
| 3563 | BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); |
| 3564 | BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); |
| 3565 | |
| 3566 | /* we're limited by original request in that |
| 3567 | * logical block must be covered any way |
| 3568 | * winl is window we can move our chunk within */ |
| 3569 | winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical; |
| 3570 | |
| 3571 | /* also, we should cover whole original request */ |
| 3572 | wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len; |
| 3573 | |
| 3574 | /* the smallest one defines real window */ |
| 3575 | win = min(winl, wins); |
| 3576 | |
| 3577 | offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len; |
| 3578 | if (offs && offs < win) |
| 3579 | win = offs; |
| 3580 | |
| 3581 | ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win; |
| 3582 | BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); |
| 3583 | BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); |
| 3584 | } |
| 3585 | |
| 3586 | /* preallocation can change ac_b_ex, thus we store actually |
| 3587 | * allocated blocks for history */ |
| 3588 | ac->ac_f_ex = ac->ac_b_ex; |
| 3589 | |
| 3590 | pa->pa_lstart = ac->ac_b_ex.fe_logical; |
| 3591 | pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| 3592 | pa->pa_len = ac->ac_b_ex.fe_len; |
| 3593 | pa->pa_free = pa->pa_len; |
| 3594 | atomic_set(&pa->pa_count, 1); |
| 3595 | spin_lock_init(&pa->pa_lock); |
| 3596 | pa->pa_deleted = 0; |
| 3597 | pa->pa_linear = 0; |
| 3598 | |
| 3599 | mb_debug("new inode pa %p: %llu/%u for %u\n", pa, |
| 3600 | pa->pa_pstart, pa->pa_len, pa->pa_lstart); |
| 3601 | |
| 3602 | ext4_mb_use_inode_pa(ac, pa); |
| 3603 | atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); |
| 3604 | |
| 3605 | ei = EXT4_I(ac->ac_inode); |
| 3606 | grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
| 3607 | |
| 3608 | pa->pa_obj_lock = &ei->i_prealloc_lock; |
| 3609 | pa->pa_inode = ac->ac_inode; |
| 3610 | |
| 3611 | ext4_lock_group(sb, ac->ac_b_ex.fe_group); |
| 3612 | list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
| 3613 | ext4_unlock_group(sb, ac->ac_b_ex.fe_group); |
| 3614 | |
| 3615 | spin_lock(pa->pa_obj_lock); |
| 3616 | list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list); |
| 3617 | spin_unlock(pa->pa_obj_lock); |
| 3618 | |
| 3619 | return 0; |
| 3620 | } |
| 3621 | |
| 3622 | /* |
| 3623 | * creates new preallocated space for locality group inodes belongs to |
| 3624 | */ |
| 3625 | static int ext4_mb_new_group_pa(struct ext4_allocation_context *ac) |
| 3626 | { |
| 3627 | struct super_block *sb = ac->ac_sb; |
| 3628 | struct ext4_locality_group *lg; |
| 3629 | struct ext4_prealloc_space *pa; |
| 3630 | struct ext4_group_info *grp; |
| 3631 | |
| 3632 | /* preallocate only when found space is larger then requested */ |
| 3633 | BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
| 3634 | BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| 3635 | BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
| 3636 | |
| 3637 | BUG_ON(ext4_pspace_cachep == NULL); |
| 3638 | pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); |
| 3639 | if (pa == NULL) |
| 3640 | return -ENOMEM; |
| 3641 | |
| 3642 | /* preallocation can change ac_b_ex, thus we store actually |
| 3643 | * allocated blocks for history */ |
| 3644 | ac->ac_f_ex = ac->ac_b_ex; |
| 3645 | |
| 3646 | pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| 3647 | pa->pa_lstart = pa->pa_pstart; |
| 3648 | pa->pa_len = ac->ac_b_ex.fe_len; |
| 3649 | pa->pa_free = pa->pa_len; |
| 3650 | atomic_set(&pa->pa_count, 1); |
| 3651 | spin_lock_init(&pa->pa_lock); |
| 3652 | pa->pa_deleted = 0; |
| 3653 | pa->pa_linear = 1; |
| 3654 | |
| 3655 | mb_debug("new group pa %p: %llu/%u for %u\n", pa, |
| 3656 | pa->pa_pstart, pa->pa_len, pa->pa_lstart); |
| 3657 | |
| 3658 | ext4_mb_use_group_pa(ac, pa); |
| 3659 | atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); |
| 3660 | |
| 3661 | grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
| 3662 | lg = ac->ac_lg; |
| 3663 | BUG_ON(lg == NULL); |
| 3664 | |
| 3665 | pa->pa_obj_lock = &lg->lg_prealloc_lock; |
| 3666 | pa->pa_inode = NULL; |
| 3667 | |
| 3668 | ext4_lock_group(sb, ac->ac_b_ex.fe_group); |
| 3669 | list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
| 3670 | ext4_unlock_group(sb, ac->ac_b_ex.fe_group); |
| 3671 | |
| 3672 | spin_lock(pa->pa_obj_lock); |
| 3673 | list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list); |
| 3674 | spin_unlock(pa->pa_obj_lock); |
| 3675 | |
| 3676 | return 0; |
| 3677 | } |
| 3678 | |
| 3679 | static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac) |
| 3680 | { |
| 3681 | int err; |
| 3682 | |
| 3683 | if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
| 3684 | err = ext4_mb_new_group_pa(ac); |
| 3685 | else |
| 3686 | err = ext4_mb_new_inode_pa(ac); |
| 3687 | return err; |
| 3688 | } |
| 3689 | |
| 3690 | /* |
| 3691 | * finds all unused blocks in on-disk bitmap, frees them in |
| 3692 | * in-core bitmap and buddy. |
| 3693 | * @pa must be unlinked from inode and group lists, so that |
| 3694 | * nobody else can find/use it. |
| 3695 | * the caller MUST hold group/inode locks. |
| 3696 | * TODO: optimize the case when there are no in-core structures yet |
| 3697 | */ |
| 3698 | static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b, |
| 3699 | struct buffer_head *bitmap_bh, |
| 3700 | struct ext4_prealloc_space *pa) |
| 3701 | { |
| 3702 | struct ext4_allocation_context ac; |
| 3703 | struct super_block *sb = e4b->bd_sb; |
| 3704 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 3705 | unsigned long end; |
| 3706 | unsigned long next; |
| 3707 | ext4_group_t group; |
| 3708 | ext4_grpblk_t bit; |
| 3709 | sector_t start; |
| 3710 | int err = 0; |
| 3711 | int free = 0; |
| 3712 | |
| 3713 | BUG_ON(pa->pa_deleted == 0); |
| 3714 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
| 3715 | BUG_ON(group != e4b->bd_group && pa->pa_len != 0); |
| 3716 | end = bit + pa->pa_len; |
| 3717 | |
| 3718 | ac.ac_sb = sb; |
| 3719 | ac.ac_inode = pa->pa_inode; |
| 3720 | ac.ac_op = EXT4_MB_HISTORY_DISCARD; |
| 3721 | |
| 3722 | while (bit < end) { |
| 3723 | bit = ext4_find_next_zero_bit(bitmap_bh->b_data, end, bit); |
| 3724 | if (bit >= end) |
| 3725 | break; |
| 3726 | next = ext4_find_next_bit(bitmap_bh->b_data, end, bit); |
| 3727 | if (next > end) |
| 3728 | next = end; |
| 3729 | start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit + |
| 3730 | le32_to_cpu(sbi->s_es->s_first_data_block); |
| 3731 | mb_debug(" free preallocated %u/%u in group %u\n", |
| 3732 | (unsigned) start, (unsigned) next - bit, |
| 3733 | (unsigned) group); |
| 3734 | free += next - bit; |
| 3735 | |
| 3736 | ac.ac_b_ex.fe_group = group; |
| 3737 | ac.ac_b_ex.fe_start = bit; |
| 3738 | ac.ac_b_ex.fe_len = next - bit; |
| 3739 | ac.ac_b_ex.fe_logical = 0; |
| 3740 | ext4_mb_store_history(&ac); |
| 3741 | |
| 3742 | mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); |
| 3743 | bit = next + 1; |
| 3744 | } |
| 3745 | if (free != pa->pa_free) { |
| 3746 | printk(KERN_ERR "pa %p: logic %lu, phys. %lu, len %lu\n", |
| 3747 | pa, (unsigned long) pa->pa_lstart, |
| 3748 | (unsigned long) pa->pa_pstart, |
| 3749 | (unsigned long) pa->pa_len); |
| 3750 | printk(KERN_ERR "free %u, pa_free %u\n", free, pa->pa_free); |
| 3751 | } |
| 3752 | BUG_ON(free != pa->pa_free); |
| 3753 | atomic_add(free, &sbi->s_mb_discarded); |
| 3754 | |
| 3755 | return err; |
| 3756 | } |
| 3757 | |
| 3758 | static int ext4_mb_release_group_pa(struct ext4_buddy *e4b, |
| 3759 | struct ext4_prealloc_space *pa) |
| 3760 | { |
| 3761 | struct ext4_allocation_context ac; |
| 3762 | struct super_block *sb = e4b->bd_sb; |
| 3763 | ext4_group_t group; |
| 3764 | ext4_grpblk_t bit; |
| 3765 | |
| 3766 | ac.ac_op = EXT4_MB_HISTORY_DISCARD; |
| 3767 | |
| 3768 | BUG_ON(pa->pa_deleted == 0); |
| 3769 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
| 3770 | BUG_ON(group != e4b->bd_group && pa->pa_len != 0); |
| 3771 | mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len); |
| 3772 | atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded); |
| 3773 | |
| 3774 | ac.ac_sb = sb; |
| 3775 | ac.ac_inode = NULL; |
| 3776 | ac.ac_b_ex.fe_group = group; |
| 3777 | ac.ac_b_ex.fe_start = bit; |
| 3778 | ac.ac_b_ex.fe_len = pa->pa_len; |
| 3779 | ac.ac_b_ex.fe_logical = 0; |
| 3780 | ext4_mb_store_history(&ac); |
| 3781 | |
| 3782 | return 0; |
| 3783 | } |
| 3784 | |
| 3785 | /* |
| 3786 | * releases all preallocations in given group |
| 3787 | * |
| 3788 | * first, we need to decide discard policy: |
| 3789 | * - when do we discard |
| 3790 | * 1) ENOSPC |
| 3791 | * - how many do we discard |
| 3792 | * 1) how many requested |
| 3793 | */ |
| 3794 | static int ext4_mb_discard_group_preallocations(struct super_block *sb, |
| 3795 | ext4_group_t group, int needed) |
| 3796 | { |
| 3797 | struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| 3798 | struct buffer_head *bitmap_bh = NULL; |
| 3799 | struct ext4_prealloc_space *pa, *tmp; |
| 3800 | struct list_head list; |
| 3801 | struct ext4_buddy e4b; |
| 3802 | int err; |
| 3803 | int busy = 0; |
| 3804 | int free = 0; |
| 3805 | |
| 3806 | mb_debug("discard preallocation for group %lu\n", group); |
| 3807 | |
| 3808 | if (list_empty(&grp->bb_prealloc_list)) |
| 3809 | return 0; |
| 3810 | |
| 3811 | bitmap_bh = read_block_bitmap(sb, group); |
| 3812 | if (bitmap_bh == NULL) { |
| 3813 | /* error handling here */ |
| 3814 | ext4_mb_release_desc(&e4b); |
| 3815 | BUG_ON(bitmap_bh == NULL); |
| 3816 | } |
| 3817 | |
| 3818 | err = ext4_mb_load_buddy(sb, group, &e4b); |
| 3819 | BUG_ON(err != 0); /* error handling here */ |
| 3820 | |
| 3821 | if (needed == 0) |
| 3822 | needed = EXT4_BLOCKS_PER_GROUP(sb) + 1; |
| 3823 | |
| 3824 | grp = ext4_get_group_info(sb, group); |
| 3825 | INIT_LIST_HEAD(&list); |
| 3826 | |
| 3827 | repeat: |
| 3828 | ext4_lock_group(sb, group); |
| 3829 | list_for_each_entry_safe(pa, tmp, |
| 3830 | &grp->bb_prealloc_list, pa_group_list) { |
| 3831 | spin_lock(&pa->pa_lock); |
| 3832 | if (atomic_read(&pa->pa_count)) { |
| 3833 | spin_unlock(&pa->pa_lock); |
| 3834 | busy = 1; |
| 3835 | continue; |
| 3836 | } |
| 3837 | if (pa->pa_deleted) { |
| 3838 | spin_unlock(&pa->pa_lock); |
| 3839 | continue; |
| 3840 | } |
| 3841 | |
| 3842 | /* seems this one can be freed ... */ |
| 3843 | pa->pa_deleted = 1; |
| 3844 | |
| 3845 | /* we can trust pa_free ... */ |
| 3846 | free += pa->pa_free; |
| 3847 | |
| 3848 | spin_unlock(&pa->pa_lock); |
| 3849 | |
| 3850 | list_del(&pa->pa_group_list); |
| 3851 | list_add(&pa->u.pa_tmp_list, &list); |
| 3852 | } |
| 3853 | |
| 3854 | /* if we still need more blocks and some PAs were used, try again */ |
| 3855 | if (free < needed && busy) { |
| 3856 | busy = 0; |
| 3857 | ext4_unlock_group(sb, group); |
| 3858 | /* |
| 3859 | * Yield the CPU here so that we don't get soft lockup |
| 3860 | * in non preempt case. |
| 3861 | */ |
| 3862 | yield(); |
| 3863 | goto repeat; |
| 3864 | } |
| 3865 | |
| 3866 | /* found anything to free? */ |
| 3867 | if (list_empty(&list)) { |
| 3868 | BUG_ON(free != 0); |
| 3869 | goto out; |
| 3870 | } |
| 3871 | |
| 3872 | /* now free all selected PAs */ |
| 3873 | list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
| 3874 | |
| 3875 | /* remove from object (inode or locality group) */ |
| 3876 | spin_lock(pa->pa_obj_lock); |
| 3877 | list_del_rcu(&pa->pa_inode_list); |
| 3878 | spin_unlock(pa->pa_obj_lock); |
| 3879 | |
| 3880 | if (pa->pa_linear) |
| 3881 | ext4_mb_release_group_pa(&e4b, pa); |
| 3882 | else |
| 3883 | ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); |
| 3884 | |
| 3885 | list_del(&pa->u.pa_tmp_list); |
| 3886 | call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| 3887 | } |
| 3888 | |
| 3889 | out: |
| 3890 | ext4_unlock_group(sb, group); |
| 3891 | ext4_mb_release_desc(&e4b); |
| 3892 | put_bh(bitmap_bh); |
| 3893 | return free; |
| 3894 | } |
| 3895 | |
| 3896 | /* |
| 3897 | * releases all non-used preallocated blocks for given inode |
| 3898 | * |
| 3899 | * It's important to discard preallocations under i_data_sem |
| 3900 | * We don't want another block to be served from the prealloc |
| 3901 | * space when we are discarding the inode prealloc space. |
| 3902 | * |
| 3903 | * FIXME!! Make sure it is valid at all the call sites |
| 3904 | */ |
| 3905 | void ext4_mb_discard_inode_preallocations(struct inode *inode) |
| 3906 | { |
| 3907 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 3908 | struct super_block *sb = inode->i_sb; |
| 3909 | struct buffer_head *bitmap_bh = NULL; |
| 3910 | struct ext4_prealloc_space *pa, *tmp; |
| 3911 | ext4_group_t group = 0; |
| 3912 | struct list_head list; |
| 3913 | struct ext4_buddy e4b; |
| 3914 | int err; |
| 3915 | |
| 3916 | if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) { |
| 3917 | /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/ |
| 3918 | return; |
| 3919 | } |
| 3920 | |
| 3921 | mb_debug("discard preallocation for inode %lu\n", inode->i_ino); |
| 3922 | |
| 3923 | INIT_LIST_HEAD(&list); |
| 3924 | |
| 3925 | repeat: |
| 3926 | /* first, collect all pa's in the inode */ |
| 3927 | spin_lock(&ei->i_prealloc_lock); |
| 3928 | while (!list_empty(&ei->i_prealloc_list)) { |
| 3929 | pa = list_entry(ei->i_prealloc_list.next, |
| 3930 | struct ext4_prealloc_space, pa_inode_list); |
| 3931 | BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock); |
| 3932 | spin_lock(&pa->pa_lock); |
| 3933 | if (atomic_read(&pa->pa_count)) { |
| 3934 | /* this shouldn't happen often - nobody should |
| 3935 | * use preallocation while we're discarding it */ |
| 3936 | spin_unlock(&pa->pa_lock); |
| 3937 | spin_unlock(&ei->i_prealloc_lock); |
| 3938 | printk(KERN_ERR "uh-oh! used pa while discarding\n"); |
| 3939 | WARN_ON(1); |
| 3940 | schedule_timeout_uninterruptible(HZ); |
| 3941 | goto repeat; |
| 3942 | |
| 3943 | } |
| 3944 | if (pa->pa_deleted == 0) { |
| 3945 | pa->pa_deleted = 1; |
| 3946 | spin_unlock(&pa->pa_lock); |
| 3947 | list_del_rcu(&pa->pa_inode_list); |
| 3948 | list_add(&pa->u.pa_tmp_list, &list); |
| 3949 | continue; |
| 3950 | } |
| 3951 | |
| 3952 | /* someone is deleting pa right now */ |
| 3953 | spin_unlock(&pa->pa_lock); |
| 3954 | spin_unlock(&ei->i_prealloc_lock); |
| 3955 | |
| 3956 | /* we have to wait here because pa_deleted |
| 3957 | * doesn't mean pa is already unlinked from |
| 3958 | * the list. as we might be called from |
| 3959 | * ->clear_inode() the inode will get freed |
| 3960 | * and concurrent thread which is unlinking |
| 3961 | * pa from inode's list may access already |
| 3962 | * freed memory, bad-bad-bad */ |
| 3963 | |
| 3964 | /* XXX: if this happens too often, we can |
| 3965 | * add a flag to force wait only in case |
| 3966 | * of ->clear_inode(), but not in case of |
| 3967 | * regular truncate */ |
| 3968 | schedule_timeout_uninterruptible(HZ); |
| 3969 | goto repeat; |
| 3970 | } |
| 3971 | spin_unlock(&ei->i_prealloc_lock); |
| 3972 | |
| 3973 | list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
| 3974 | BUG_ON(pa->pa_linear != 0); |
| 3975 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL); |
| 3976 | |
| 3977 | err = ext4_mb_load_buddy(sb, group, &e4b); |
| 3978 | BUG_ON(err != 0); /* error handling here */ |
| 3979 | |
| 3980 | bitmap_bh = read_block_bitmap(sb, group); |
| 3981 | if (bitmap_bh == NULL) { |
| 3982 | /* error handling here */ |
| 3983 | ext4_mb_release_desc(&e4b); |
| 3984 | BUG_ON(bitmap_bh == NULL); |
| 3985 | } |
| 3986 | |
| 3987 | ext4_lock_group(sb, group); |
| 3988 | list_del(&pa->pa_group_list); |
| 3989 | ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); |
| 3990 | ext4_unlock_group(sb, group); |
| 3991 | |
| 3992 | ext4_mb_release_desc(&e4b); |
| 3993 | put_bh(bitmap_bh); |
| 3994 | |
| 3995 | list_del(&pa->u.pa_tmp_list); |
| 3996 | call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| 3997 | } |
| 3998 | } |
| 3999 | |
| 4000 | /* |
| 4001 | * finds all preallocated spaces and return blocks being freed to them |
| 4002 | * if preallocated space becomes full (no block is used from the space) |
| 4003 | * then the function frees space in buddy |
| 4004 | * XXX: at the moment, truncate (which is the only way to free blocks) |
| 4005 | * discards all preallocations |
| 4006 | */ |
| 4007 | static void ext4_mb_return_to_preallocation(struct inode *inode, |
| 4008 | struct ext4_buddy *e4b, |
| 4009 | sector_t block, int count) |
| 4010 | { |
| 4011 | BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list)); |
| 4012 | } |
| 4013 | #ifdef MB_DEBUG |
| 4014 | static void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
| 4015 | { |
| 4016 | struct super_block *sb = ac->ac_sb; |
| 4017 | ext4_group_t i; |
| 4018 | |
| 4019 | printk(KERN_ERR "EXT4-fs: Can't allocate:" |
| 4020 | " Allocation context details:\n"); |
| 4021 | printk(KERN_ERR "EXT4-fs: status %d flags %d\n", |
| 4022 | ac->ac_status, ac->ac_flags); |
| 4023 | printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, " |
| 4024 | "best %lu/%lu/%lu@%lu cr %d\n", |
| 4025 | (unsigned long)ac->ac_o_ex.fe_group, |
| 4026 | (unsigned long)ac->ac_o_ex.fe_start, |
| 4027 | (unsigned long)ac->ac_o_ex.fe_len, |
| 4028 | (unsigned long)ac->ac_o_ex.fe_logical, |
| 4029 | (unsigned long)ac->ac_g_ex.fe_group, |
| 4030 | (unsigned long)ac->ac_g_ex.fe_start, |
| 4031 | (unsigned long)ac->ac_g_ex.fe_len, |
| 4032 | (unsigned long)ac->ac_g_ex.fe_logical, |
| 4033 | (unsigned long)ac->ac_b_ex.fe_group, |
| 4034 | (unsigned long)ac->ac_b_ex.fe_start, |
| 4035 | (unsigned long)ac->ac_b_ex.fe_len, |
| 4036 | (unsigned long)ac->ac_b_ex.fe_logical, |
| 4037 | (int)ac->ac_criteria); |
| 4038 | printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned, |
| 4039 | ac->ac_found); |
| 4040 | printk(KERN_ERR "EXT4-fs: groups: \n"); |
| 4041 | for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { |
| 4042 | struct ext4_group_info *grp = ext4_get_group_info(sb, i); |
| 4043 | struct ext4_prealloc_space *pa; |
| 4044 | ext4_grpblk_t start; |
| 4045 | struct list_head *cur; |
| 4046 | ext4_lock_group(sb, i); |
| 4047 | list_for_each(cur, &grp->bb_prealloc_list) { |
| 4048 | pa = list_entry(cur, struct ext4_prealloc_space, |
| 4049 | pa_group_list); |
| 4050 | spin_lock(&pa->pa_lock); |
| 4051 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
| 4052 | NULL, &start); |
| 4053 | spin_unlock(&pa->pa_lock); |
| 4054 | printk(KERN_ERR "PA:%lu:%d:%u \n", i, |
| 4055 | start, pa->pa_len); |
| 4056 | } |
| 4057 | ext4_lock_group(sb, i); |
| 4058 | |
| 4059 | if (grp->bb_free == 0) |
| 4060 | continue; |
| 4061 | printk(KERN_ERR "%lu: %d/%d \n", |
| 4062 | i, grp->bb_free, grp->bb_fragments); |
| 4063 | } |
| 4064 | printk(KERN_ERR "\n"); |
| 4065 | } |
| 4066 | #else |
| 4067 | static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
| 4068 | { |
| 4069 | return; |
| 4070 | } |
| 4071 | #endif |
| 4072 | |
| 4073 | /* |
| 4074 | * We use locality group preallocation for small size file. The size of the |
| 4075 | * file is determined by the current size or the resulting size after |
| 4076 | * allocation which ever is larger |
| 4077 | * |
| 4078 | * One can tune this size via /proc/fs/ext4/<partition>/stream_req |
| 4079 | */ |
| 4080 | static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) |
| 4081 | { |
| 4082 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| 4083 | int bsbits = ac->ac_sb->s_blocksize_bits; |
| 4084 | loff_t size, isize; |
| 4085 | |
| 4086 | if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| 4087 | return; |
| 4088 | |
| 4089 | size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len; |
| 4090 | isize = i_size_read(ac->ac_inode) >> bsbits; |
| 4091 | size = max(size, isize); |
| 4092 | |
| 4093 | /* don't use group allocation for large files */ |
| 4094 | if (size >= sbi->s_mb_stream_request) |
| 4095 | return; |
| 4096 | |
| 4097 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| 4098 | return; |
| 4099 | |
| 4100 | BUG_ON(ac->ac_lg != NULL); |
| 4101 | /* |
| 4102 | * locality group prealloc space are per cpu. The reason for having |
| 4103 | * per cpu locality group is to reduce the contention between block |
| 4104 | * request from multiple CPUs. |
| 4105 | */ |
| 4106 | ac->ac_lg = &sbi->s_locality_groups[get_cpu()]; |
| 4107 | put_cpu(); |
| 4108 | |
| 4109 | /* we're going to use group allocation */ |
| 4110 | ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC; |
| 4111 | |
| 4112 | /* serialize all allocations in the group */ |
| 4113 | mutex_lock(&ac->ac_lg->lg_mutex); |
| 4114 | } |
| 4115 | |
| 4116 | static int ext4_mb_initialize_context(struct ext4_allocation_context *ac, |
| 4117 | struct ext4_allocation_request *ar) |
| 4118 | { |
| 4119 | struct super_block *sb = ar->inode->i_sb; |
| 4120 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 4121 | struct ext4_super_block *es = sbi->s_es; |
| 4122 | ext4_group_t group; |
| 4123 | unsigned long len; |
| 4124 | unsigned long goal; |
| 4125 | ext4_grpblk_t block; |
| 4126 | |
| 4127 | /* we can't allocate > group size */ |
| 4128 | len = ar->len; |
| 4129 | |
| 4130 | /* just a dirty hack to filter too big requests */ |
| 4131 | if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10) |
| 4132 | len = EXT4_BLOCKS_PER_GROUP(sb) - 10; |
| 4133 | |
| 4134 | /* start searching from the goal */ |
| 4135 | goal = ar->goal; |
| 4136 | if (goal < le32_to_cpu(es->s_first_data_block) || |
| 4137 | goal >= ext4_blocks_count(es)) |
| 4138 | goal = le32_to_cpu(es->s_first_data_block); |
| 4139 | ext4_get_group_no_and_offset(sb, goal, &group, &block); |
| 4140 | |
| 4141 | /* set up allocation goals */ |
| 4142 | ac->ac_b_ex.fe_logical = ar->logical; |
| 4143 | ac->ac_b_ex.fe_group = 0; |
| 4144 | ac->ac_b_ex.fe_start = 0; |
| 4145 | ac->ac_b_ex.fe_len = 0; |
| 4146 | ac->ac_status = AC_STATUS_CONTINUE; |
| 4147 | ac->ac_groups_scanned = 0; |
| 4148 | ac->ac_ex_scanned = 0; |
| 4149 | ac->ac_found = 0; |
| 4150 | ac->ac_sb = sb; |
| 4151 | ac->ac_inode = ar->inode; |
| 4152 | ac->ac_o_ex.fe_logical = ar->logical; |
| 4153 | ac->ac_o_ex.fe_group = group; |
| 4154 | ac->ac_o_ex.fe_start = block; |
| 4155 | ac->ac_o_ex.fe_len = len; |
| 4156 | ac->ac_g_ex.fe_logical = ar->logical; |
| 4157 | ac->ac_g_ex.fe_group = group; |
| 4158 | ac->ac_g_ex.fe_start = block; |
| 4159 | ac->ac_g_ex.fe_len = len; |
| 4160 | ac->ac_f_ex.fe_len = 0; |
| 4161 | ac->ac_flags = ar->flags; |
| 4162 | ac->ac_2order = 0; |
| 4163 | ac->ac_criteria = 0; |
| 4164 | ac->ac_pa = NULL; |
| 4165 | ac->ac_bitmap_page = NULL; |
| 4166 | ac->ac_buddy_page = NULL; |
| 4167 | ac->ac_lg = NULL; |
| 4168 | |
| 4169 | /* we have to define context: we'll we work with a file or |
| 4170 | * locality group. this is a policy, actually */ |
| 4171 | ext4_mb_group_or_file(ac); |
| 4172 | |
| 4173 | mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, " |
| 4174 | "left: %u/%u, right %u/%u to %swritable\n", |
| 4175 | (unsigned) ar->len, (unsigned) ar->logical, |
| 4176 | (unsigned) ar->goal, ac->ac_flags, ac->ac_2order, |
| 4177 | (unsigned) ar->lleft, (unsigned) ar->pleft, |
| 4178 | (unsigned) ar->lright, (unsigned) ar->pright, |
| 4179 | atomic_read(&ar->inode->i_writecount) ? "" : "non-"); |
| 4180 | return 0; |
| 4181 | |
| 4182 | } |
| 4183 | |
| 4184 | /* |
| 4185 | * release all resource we used in allocation |
| 4186 | */ |
| 4187 | static int ext4_mb_release_context(struct ext4_allocation_context *ac) |
| 4188 | { |
| 4189 | if (ac->ac_pa) { |
| 4190 | if (ac->ac_pa->pa_linear) { |
| 4191 | /* see comment in ext4_mb_use_group_pa() */ |
| 4192 | spin_lock(&ac->ac_pa->pa_lock); |
| 4193 | ac->ac_pa->pa_pstart += ac->ac_b_ex.fe_len; |
| 4194 | ac->ac_pa->pa_lstart += ac->ac_b_ex.fe_len; |
| 4195 | ac->ac_pa->pa_free -= ac->ac_b_ex.fe_len; |
| 4196 | ac->ac_pa->pa_len -= ac->ac_b_ex.fe_len; |
| 4197 | spin_unlock(&ac->ac_pa->pa_lock); |
| 4198 | } |
| 4199 | ext4_mb_put_pa(ac, ac->ac_sb, ac->ac_pa); |
| 4200 | } |
| 4201 | if (ac->ac_bitmap_page) |
| 4202 | page_cache_release(ac->ac_bitmap_page); |
| 4203 | if (ac->ac_buddy_page) |
| 4204 | page_cache_release(ac->ac_buddy_page); |
| 4205 | if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
| 4206 | mutex_unlock(&ac->ac_lg->lg_mutex); |
| 4207 | ext4_mb_collect_stats(ac); |
| 4208 | return 0; |
| 4209 | } |
| 4210 | |
| 4211 | static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) |
| 4212 | { |
| 4213 | ext4_group_t i; |
| 4214 | int ret; |
| 4215 | int freed = 0; |
| 4216 | |
| 4217 | for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) { |
| 4218 | ret = ext4_mb_discard_group_preallocations(sb, i, needed); |
| 4219 | freed += ret; |
| 4220 | needed -= ret; |
| 4221 | } |
| 4222 | |
| 4223 | return freed; |
| 4224 | } |
| 4225 | |
| 4226 | /* |
| 4227 | * Main entry point into mballoc to allocate blocks |
| 4228 | * it tries to use preallocation first, then falls back |
| 4229 | * to usual allocation |
| 4230 | */ |
| 4231 | ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, |
| 4232 | struct ext4_allocation_request *ar, int *errp) |
| 4233 | { |
| 4234 | struct ext4_allocation_context ac; |
| 4235 | struct ext4_sb_info *sbi; |
| 4236 | struct super_block *sb; |
| 4237 | ext4_fsblk_t block = 0; |
| 4238 | int freed; |
| 4239 | int inquota; |
| 4240 | |
| 4241 | sb = ar->inode->i_sb; |
| 4242 | sbi = EXT4_SB(sb); |
| 4243 | |
| 4244 | if (!test_opt(sb, MBALLOC)) { |
| 4245 | block = ext4_new_blocks_old(handle, ar->inode, ar->goal, |
| 4246 | &(ar->len), errp); |
| 4247 | return block; |
| 4248 | } |
| 4249 | |
| 4250 | while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) { |
| 4251 | ar->flags |= EXT4_MB_HINT_NOPREALLOC; |
| 4252 | ar->len--; |
| 4253 | } |
| 4254 | if (ar->len == 0) { |
| 4255 | *errp = -EDQUOT; |
| 4256 | return 0; |
| 4257 | } |
| 4258 | inquota = ar->len; |
| 4259 | |
| 4260 | ext4_mb_poll_new_transaction(sb, handle); |
| 4261 | |
| 4262 | *errp = ext4_mb_initialize_context(&ac, ar); |
| 4263 | if (*errp) { |
| 4264 | ar->len = 0; |
| 4265 | goto out; |
| 4266 | } |
| 4267 | |
| 4268 | ac.ac_op = EXT4_MB_HISTORY_PREALLOC; |
| 4269 | if (!ext4_mb_use_preallocated(&ac)) { |
| 4270 | |
| 4271 | ac.ac_op = EXT4_MB_HISTORY_ALLOC; |
| 4272 | ext4_mb_normalize_request(&ac, ar); |
| 4273 | |
| 4274 | repeat: |
| 4275 | /* allocate space in core */ |
| 4276 | ext4_mb_regular_allocator(&ac); |
| 4277 | |
| 4278 | /* as we've just preallocated more space than |
| 4279 | * user requested orinally, we store allocated |
| 4280 | * space in a special descriptor */ |
| 4281 | if (ac.ac_status == AC_STATUS_FOUND && |
| 4282 | ac.ac_o_ex.fe_len < ac.ac_b_ex.fe_len) |
| 4283 | ext4_mb_new_preallocation(&ac); |
| 4284 | } |
| 4285 | |
| 4286 | if (likely(ac.ac_status == AC_STATUS_FOUND)) { |
| 4287 | ext4_mb_mark_diskspace_used(&ac, handle); |
| 4288 | *errp = 0; |
| 4289 | block = ext4_grp_offs_to_block(sb, &ac.ac_b_ex); |
| 4290 | ar->len = ac.ac_b_ex.fe_len; |
| 4291 | } else { |
| 4292 | freed = ext4_mb_discard_preallocations(sb, ac.ac_o_ex.fe_len); |
| 4293 | if (freed) |
| 4294 | goto repeat; |
| 4295 | *errp = -ENOSPC; |
| 4296 | ac.ac_b_ex.fe_len = 0; |
| 4297 | ar->len = 0; |
| 4298 | ext4_mb_show_ac(&ac); |
| 4299 | } |
| 4300 | |
| 4301 | ext4_mb_release_context(&ac); |
| 4302 | |
| 4303 | out: |
| 4304 | if (ar->len < inquota) |
| 4305 | DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len); |
| 4306 | |
| 4307 | return block; |
| 4308 | } |
| 4309 | static void ext4_mb_poll_new_transaction(struct super_block *sb, |
| 4310 | handle_t *handle) |
| 4311 | { |
| 4312 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 4313 | |
| 4314 | if (sbi->s_last_transaction == handle->h_transaction->t_tid) |
| 4315 | return; |
| 4316 | |
| 4317 | /* new transaction! time to close last one and free blocks for |
| 4318 | * committed transaction. we know that only transaction can be |
| 4319 | * active, so previos transaction can be being logged and we |
| 4320 | * know that transaction before previous is known to be already |
| 4321 | * logged. this means that now we may free blocks freed in all |
| 4322 | * transactions before previous one. hope I'm clear enough ... */ |
| 4323 | |
| 4324 | spin_lock(&sbi->s_md_lock); |
| 4325 | if (sbi->s_last_transaction != handle->h_transaction->t_tid) { |
| 4326 | mb_debug("new transaction %lu, old %lu\n", |
| 4327 | (unsigned long) handle->h_transaction->t_tid, |
| 4328 | (unsigned long) sbi->s_last_transaction); |
| 4329 | list_splice_init(&sbi->s_closed_transaction, |
| 4330 | &sbi->s_committed_transaction); |
| 4331 | list_splice_init(&sbi->s_active_transaction, |
| 4332 | &sbi->s_closed_transaction); |
| 4333 | sbi->s_last_transaction = handle->h_transaction->t_tid; |
| 4334 | } |
| 4335 | spin_unlock(&sbi->s_md_lock); |
| 4336 | |
| 4337 | ext4_mb_free_committed_blocks(sb); |
| 4338 | } |
| 4339 | |
| 4340 | static int ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, |
| 4341 | ext4_group_t group, ext4_grpblk_t block, int count) |
| 4342 | { |
| 4343 | struct ext4_group_info *db = e4b->bd_info; |
| 4344 | struct super_block *sb = e4b->bd_sb; |
| 4345 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 4346 | struct ext4_free_metadata *md; |
| 4347 | int i; |
| 4348 | |
| 4349 | BUG_ON(e4b->bd_bitmap_page == NULL); |
| 4350 | BUG_ON(e4b->bd_buddy_page == NULL); |
| 4351 | |
| 4352 | ext4_lock_group(sb, group); |
| 4353 | for (i = 0; i < count; i++) { |
| 4354 | md = db->bb_md_cur; |
| 4355 | if (md && db->bb_tid != handle->h_transaction->t_tid) { |
| 4356 | db->bb_md_cur = NULL; |
| 4357 | md = NULL; |
| 4358 | } |
| 4359 | |
| 4360 | if (md == NULL) { |
| 4361 | ext4_unlock_group(sb, group); |
| 4362 | md = kmalloc(sizeof(*md), GFP_NOFS); |
| 4363 | if (md == NULL) |
| 4364 | return -ENOMEM; |
| 4365 | md->num = 0; |
| 4366 | md->group = group; |
| 4367 | |
| 4368 | ext4_lock_group(sb, group); |
| 4369 | if (db->bb_md_cur == NULL) { |
| 4370 | spin_lock(&sbi->s_md_lock); |
| 4371 | list_add(&md->list, &sbi->s_active_transaction); |
| 4372 | spin_unlock(&sbi->s_md_lock); |
| 4373 | /* protect buddy cache from being freed, |
| 4374 | * otherwise we'll refresh it from |
| 4375 | * on-disk bitmap and lose not-yet-available |
| 4376 | * blocks */ |
| 4377 | page_cache_get(e4b->bd_buddy_page); |
| 4378 | page_cache_get(e4b->bd_bitmap_page); |
| 4379 | db->bb_md_cur = md; |
| 4380 | db->bb_tid = handle->h_transaction->t_tid; |
| 4381 | mb_debug("new md 0x%p for group %lu\n", |
| 4382 | md, md->group); |
| 4383 | } else { |
| 4384 | kfree(md); |
| 4385 | md = db->bb_md_cur; |
| 4386 | } |
| 4387 | } |
| 4388 | |
| 4389 | BUG_ON(md->num >= EXT4_BB_MAX_BLOCKS); |
| 4390 | md->blocks[md->num] = block + i; |
| 4391 | md->num++; |
| 4392 | if (md->num == EXT4_BB_MAX_BLOCKS) { |
| 4393 | /* no more space, put full container on a sb's list */ |
| 4394 | db->bb_md_cur = NULL; |
| 4395 | } |
| 4396 | } |
| 4397 | ext4_unlock_group(sb, group); |
| 4398 | return 0; |
| 4399 | } |
| 4400 | |
| 4401 | /* |
| 4402 | * Main entry point into mballoc to free blocks |
| 4403 | */ |
| 4404 | void ext4_mb_free_blocks(handle_t *handle, struct inode *inode, |
| 4405 | unsigned long block, unsigned long count, |
| 4406 | int metadata, unsigned long *freed) |
| 4407 | { |
| 4408 | struct buffer_head *bitmap_bh = 0; |
| 4409 | struct super_block *sb = inode->i_sb; |
| 4410 | struct ext4_allocation_context ac; |
| 4411 | struct ext4_group_desc *gdp; |
| 4412 | struct ext4_super_block *es; |
| 4413 | unsigned long overflow; |
| 4414 | ext4_grpblk_t bit; |
| 4415 | struct buffer_head *gd_bh; |
| 4416 | ext4_group_t block_group; |
| 4417 | struct ext4_sb_info *sbi; |
| 4418 | struct ext4_buddy e4b; |
| 4419 | int err = 0; |
| 4420 | int ret; |
| 4421 | |
| 4422 | *freed = 0; |
| 4423 | |
| 4424 | ext4_mb_poll_new_transaction(sb, handle); |
| 4425 | |
| 4426 | sbi = EXT4_SB(sb); |
| 4427 | es = EXT4_SB(sb)->s_es; |
| 4428 | if (block < le32_to_cpu(es->s_first_data_block) || |
| 4429 | block + count < block || |
| 4430 | block + count > ext4_blocks_count(es)) { |
| 4431 | ext4_error(sb, __FUNCTION__, |
| 4432 | "Freeing blocks not in datazone - " |
| 4433 | "block = %lu, count = %lu", block, count); |
| 4434 | goto error_return; |
| 4435 | } |
| 4436 | |
| 4437 | ext4_debug("freeing block %lu\n", block); |
| 4438 | |
| 4439 | ac.ac_op = EXT4_MB_HISTORY_FREE; |
| 4440 | ac.ac_inode = inode; |
| 4441 | ac.ac_sb = sb; |
| 4442 | |
| 4443 | do_more: |
| 4444 | overflow = 0; |
| 4445 | ext4_get_group_no_and_offset(sb, block, &block_group, &bit); |
| 4446 | |
| 4447 | /* |
| 4448 | * Check to see if we are freeing blocks across a group |
| 4449 | * boundary. |
| 4450 | */ |
| 4451 | if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) { |
| 4452 | overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb); |
| 4453 | count -= overflow; |
| 4454 | } |
| 4455 | bitmap_bh = read_block_bitmap(sb, block_group); |
| 4456 | if (!bitmap_bh) |
| 4457 | goto error_return; |
| 4458 | gdp = ext4_get_group_desc(sb, block_group, &gd_bh); |
| 4459 | if (!gdp) |
| 4460 | goto error_return; |
| 4461 | |
| 4462 | if (in_range(ext4_block_bitmap(sb, gdp), block, count) || |
| 4463 | in_range(ext4_inode_bitmap(sb, gdp), block, count) || |
| 4464 | in_range(block, ext4_inode_table(sb, gdp), |
| 4465 | EXT4_SB(sb)->s_itb_per_group) || |
| 4466 | in_range(block + count - 1, ext4_inode_table(sb, gdp), |
| 4467 | EXT4_SB(sb)->s_itb_per_group)) { |
| 4468 | |
| 4469 | ext4_error(sb, __FUNCTION__, |
| 4470 | "Freeing blocks in system zone - " |
| 4471 | "Block = %lu, count = %lu", block, count); |
| 4472 | } |
| 4473 | |
| 4474 | BUFFER_TRACE(bitmap_bh, "getting write access"); |
| 4475 | err = ext4_journal_get_write_access(handle, bitmap_bh); |
| 4476 | if (err) |
| 4477 | goto error_return; |
| 4478 | |
| 4479 | /* |
| 4480 | * We are about to modify some metadata. Call the journal APIs |
| 4481 | * to unshare ->b_data if a currently-committing transaction is |
| 4482 | * using it |
| 4483 | */ |
| 4484 | BUFFER_TRACE(gd_bh, "get_write_access"); |
| 4485 | err = ext4_journal_get_write_access(handle, gd_bh); |
| 4486 | if (err) |
| 4487 | goto error_return; |
| 4488 | |
| 4489 | err = ext4_mb_load_buddy(sb, block_group, &e4b); |
| 4490 | if (err) |
| 4491 | goto error_return; |
| 4492 | |
| 4493 | #ifdef AGGRESSIVE_CHECK |
| 4494 | { |
| 4495 | int i; |
| 4496 | for (i = 0; i < count; i++) |
| 4497 | BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data)); |
| 4498 | } |
| 4499 | #endif |
| 4500 | mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data, |
| 4501 | bit, count); |
| 4502 | |
| 4503 | /* We dirtied the bitmap block */ |
| 4504 | BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); |
| 4505 | err = ext4_journal_dirty_metadata(handle, bitmap_bh); |
| 4506 | |
| 4507 | ac.ac_b_ex.fe_group = block_group; |
| 4508 | ac.ac_b_ex.fe_start = bit; |
| 4509 | ac.ac_b_ex.fe_len = count; |
| 4510 | ext4_mb_store_history(&ac); |
| 4511 | |
| 4512 | if (metadata) { |
| 4513 | /* blocks being freed are metadata. these blocks shouldn't |
| 4514 | * be used until this transaction is committed */ |
| 4515 | ext4_mb_free_metadata(handle, &e4b, block_group, bit, count); |
| 4516 | } else { |
| 4517 | ext4_lock_group(sb, block_group); |
| 4518 | err = mb_free_blocks(inode, &e4b, bit, count); |
| 4519 | ext4_mb_return_to_preallocation(inode, &e4b, block, count); |
| 4520 | ext4_unlock_group(sb, block_group); |
| 4521 | BUG_ON(err != 0); |
| 4522 | } |
| 4523 | |
| 4524 | spin_lock(sb_bgl_lock(sbi, block_group)); |
| 4525 | gdp->bg_free_blocks_count = |
| 4526 | cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) + count); |
| 4527 | gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); |
| 4528 | spin_unlock(sb_bgl_lock(sbi, block_group)); |
| 4529 | percpu_counter_add(&sbi->s_freeblocks_counter, count); |
| 4530 | |
| 4531 | ext4_mb_release_desc(&e4b); |
| 4532 | |
| 4533 | *freed += count; |
| 4534 | |
| 4535 | /* And the group descriptor block */ |
| 4536 | BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); |
| 4537 | ret = ext4_journal_dirty_metadata(handle, gd_bh); |
| 4538 | if (!err) |
| 4539 | err = ret; |
| 4540 | |
| 4541 | if (overflow && !err) { |
| 4542 | block += count; |
| 4543 | count = overflow; |
| 4544 | put_bh(bitmap_bh); |
| 4545 | goto do_more; |
| 4546 | } |
| 4547 | sb->s_dirt = 1; |
| 4548 | error_return: |
| 4549 | brelse(bitmap_bh); |
| 4550 | ext4_std_error(sb, err); |
| 4551 | return; |
| 4552 | } |