1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2014 Facebook. All rights reserved. 4 */ 5 6 #ifndef BTRFS_QGROUP_H 7 #define BTRFS_QGROUP_H 8 9 #include <linux/spinlock.h> 10 #include <linux/rbtree.h> 11 #include <linux/kobject.h> 12 #include "ulist.h" 13 #include "delayed-ref.h" 14 #include "misc.h" 15 16 /* 17 * Btrfs qgroup overview 18 * 19 * Btrfs qgroup splits into 3 main part: 20 * 1) Reserve 21 * Reserve metadata/data space for incoming operations 22 * Affect how qgroup limit works 23 * 24 * 2) Trace 25 * Tell btrfs qgroup to trace dirty extents. 26 * 27 * Dirty extents including: 28 * - Newly allocated extents 29 * - Extents going to be deleted (in this trans) 30 * - Extents whose owner is going to be modified 31 * 32 * This is the main part affects whether qgroup numbers will stay 33 * consistent. 34 * Btrfs qgroup can trace clean extents and won't cause any problem, 35 * but it will consume extra CPU time, it should be avoided if possible. 36 * 37 * 3) Account 38 * Btrfs qgroup will updates its numbers, based on dirty extents traced 39 * in previous step. 40 * 41 * Normally at qgroup rescan and transaction commit time. 42 */ 43 44 /* 45 * Special performance optimization for balance. 46 * 47 * For balance, we need to swap subtree of subvolume and reloc trees. 48 * In theory, we need to trace all subtree blocks of both subvolume and reloc 49 * trees, since their owner has changed during such swap. 50 * 51 * However since balance has ensured that both subtrees are containing the 52 * same contents and have the same tree structures, such swap won't cause 53 * qgroup number change. 54 * 55 * But there is a race window between subtree swap and transaction commit, 56 * during that window, if we increase/decrease tree level or merge/split tree 57 * blocks, we still need to trace the original subtrees. 58 * 59 * So for balance, we use a delayed subtree tracing, whose workflow is: 60 * 61 * 1) Record the subtree root block get swapped. 62 * 63 * During subtree swap: 64 * O = Old tree blocks 65 * N = New tree blocks 66 * reloc tree subvolume tree X 67 * Root Root 68 * / \ / \ 69 * NA OB OA OB 70 * / | | \ / | | \ 71 * NC ND OE OF OC OD OE OF 72 * 73 * In this case, NA and OA are going to be swapped, record (NA, OA) into 74 * subvolume tree X. 75 * 76 * 2) After subtree swap. 77 * reloc tree subvolume tree X 78 * Root Root 79 * / \ / \ 80 * OA OB NA OB 81 * / | | \ / | | \ 82 * OC OD OE OF NC ND OE OF 83 * 84 * 3a) COW happens for OB 85 * If we are going to COW tree block OB, we check OB's bytenr against 86 * tree X's swapped_blocks structure. 87 * If it doesn't fit any, nothing will happen. 88 * 89 * 3b) COW happens for NA 90 * Check NA's bytenr against tree X's swapped_blocks, and get a hit. 91 * Then we do subtree scan on both subtrees OA and NA. 92 * Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND). 93 * 94 * Then no matter what we do to subvolume tree X, qgroup numbers will 95 * still be correct. 96 * Then NA's record gets removed from X's swapped_blocks. 97 * 98 * 4) Transaction commit 99 * Any record in X's swapped_blocks gets removed, since there is no 100 * modification to the swapped subtrees, no need to trigger heavy qgroup 101 * subtree rescan for them. 102 */ 103 104 #define BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN (1UL << 3) 105 #define BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING (1UL << 4) 106 107 /* 108 * Record a dirty extent, and info qgroup to update quota on it 109 * TODO: Use kmem cache to alloc it. 110 */ 111 struct btrfs_qgroup_extent_record { 112 struct rb_node node; 113 u64 bytenr; 114 u64 num_bytes; 115 116 /* 117 * For qgroup reserved data space freeing. 118 * 119 * @data_rsv_refroot and @data_rsv will be recorded after 120 * BTRFS_ADD_DELAYED_EXTENT is called. 121 * And will be used to free reserved qgroup space at 122 * transaction commit time. 123 */ 124 u32 data_rsv; /* reserved data space needs to be freed */ 125 u64 data_rsv_refroot; /* which root the reserved data belongs to */ 126 struct ulist *old_roots; 127 }; 128 129 struct btrfs_qgroup_swapped_block { 130 struct rb_node node; 131 132 int level; 133 bool trace_leaf; 134 135 /* bytenr/generation of the tree block in subvolume tree after swap */ 136 u64 subvol_bytenr; 137 u64 subvol_generation; 138 139 /* bytenr/generation of the tree block in reloc tree after swap */ 140 u64 reloc_bytenr; 141 u64 reloc_generation; 142 143 u64 last_snapshot; 144 struct btrfs_key first_key; 145 }; 146 147 /* 148 * Qgroup reservation types: 149 * 150 * DATA: 151 * space reserved for data 152 * 153 * META_PERTRANS: 154 * Space reserved for metadata (per-transaction) 155 * Due to the fact that qgroup data is only updated at transaction commit 156 * time, reserved space for metadata must be kept until transaction 157 * commits. 158 * Any metadata reserved that are used in btrfs_start_transaction() should 159 * be of this type. 160 * 161 * META_PREALLOC: 162 * There are cases where metadata space is reserved before starting 163 * transaction, and then btrfs_join_transaction() to get a trans handle. 164 * Any metadata reserved for such usage should be of this type. 165 * And after join_transaction() part (or all) of such reservation should 166 * be converted into META_PERTRANS. 167 */ 168 enum btrfs_qgroup_rsv_type { 169 BTRFS_QGROUP_RSV_DATA, 170 BTRFS_QGROUP_RSV_META_PERTRANS, 171 BTRFS_QGROUP_RSV_META_PREALLOC, 172 BTRFS_QGROUP_RSV_LAST, 173 }; 174 175 /* 176 * Represents how many bytes we have reserved for this qgroup. 177 * 178 * Each type should have different reservation behavior. 179 * E.g, data follows its io_tree flag modification, while 180 * *currently* meta is just reserve-and-clear during transaction. 181 * 182 * TODO: Add new type for reservation which can survive transaction commit. 183 * Current metadata reservation behavior is not suitable for such case. 184 */ 185 struct btrfs_qgroup_rsv { 186 u64 values[BTRFS_QGROUP_RSV_LAST]; 187 }; 188 189 /* 190 * one struct for each qgroup, organized in fs_info->qgroup_tree. 191 */ 192 struct btrfs_qgroup { 193 u64 qgroupid; 194 195 /* 196 * state 197 */ 198 u64 rfer; /* referenced */ 199 u64 rfer_cmpr; /* referenced compressed */ 200 u64 excl; /* exclusive */ 201 u64 excl_cmpr; /* exclusive compressed */ 202 203 /* 204 * limits 205 */ 206 u64 lim_flags; /* which limits are set */ 207 u64 max_rfer; 208 u64 max_excl; 209 u64 rsv_rfer; 210 u64 rsv_excl; 211 212 /* 213 * reservation tracking 214 */ 215 struct btrfs_qgroup_rsv rsv; 216 217 /* 218 * lists 219 */ 220 struct list_head groups; /* groups this group is member of */ 221 struct list_head members; /* groups that are members of this group */ 222 struct list_head dirty; /* dirty groups */ 223 224 /* 225 * For qgroup iteration usage. 226 * 227 * The iteration list should always be empty until qgroup_iterator_add() 228 * is called. And should be reset to empty after the iteration is 229 * finished. 230 */ 231 struct list_head iterator; 232 struct rb_node node; /* tree of qgroups */ 233 234 /* 235 * temp variables for accounting operations 236 * Refer to qgroup_shared_accounting() for details. 237 */ 238 u64 old_refcnt; 239 u64 new_refcnt; 240 241 /* 242 * Sysfs kobjectid 243 */ 244 struct kobject kobj; 245 }; 246 247 static inline u64 btrfs_qgroup_subvolid(u64 qgroupid) 248 { 249 return (qgroupid & ((1ULL << BTRFS_QGROUP_LEVEL_SHIFT) - 1)); 250 } 251 252 /* 253 * For qgroup event trace points only 254 */ 255 enum { 256 ENUM_BIT(QGROUP_RESERVE), 257 ENUM_BIT(QGROUP_RELEASE), 258 ENUM_BIT(QGROUP_FREE), 259 }; 260 261 int btrfs_quota_enable(struct btrfs_fs_info *fs_info); 262 int btrfs_quota_disable(struct btrfs_fs_info *fs_info); 263 int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info); 264 void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info); 265 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info, 266 bool interruptible); 267 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, 268 u64 dst); 269 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, 270 u64 dst); 271 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid); 272 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid); 273 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid, 274 struct btrfs_qgroup_limit *limit); 275 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info); 276 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info); 277 struct btrfs_delayed_extent_op; 278 279 /* 280 * Inform qgroup to trace one dirty extent, its info is recorded in @record. 281 * So qgroup can account it at transaction committing time. 282 * 283 * No lock version, caller must acquire delayed ref lock and allocated memory, 284 * then call btrfs_qgroup_trace_extent_post() after exiting lock context. 285 * 286 * Return 0 for success insert 287 * Return >0 for existing record, caller can free @record safely. 288 * Error is not possible 289 */ 290 int btrfs_qgroup_trace_extent_nolock( 291 struct btrfs_fs_info *fs_info, 292 struct btrfs_delayed_ref_root *delayed_refs, 293 struct btrfs_qgroup_extent_record *record); 294 295 /* 296 * Post handler after qgroup_trace_extent_nolock(). 297 * 298 * NOTE: Current qgroup does the expensive backref walk at transaction 299 * committing time with TRANS_STATE_COMMIT_DOING, this blocks incoming 300 * new transaction. 301 * This is designed to allow btrfs_find_all_roots() to get correct new_roots 302 * result. 303 * 304 * However for old_roots there is no need to do backref walk at that time, 305 * since we search commit roots to walk backref and result will always be 306 * correct. 307 * 308 * Due to the nature of no lock version, we can't do backref there. 309 * So we must call btrfs_qgroup_trace_extent_post() after exiting 310 * spinlock context. 311 * 312 * TODO: If we can fix and prove btrfs_find_all_roots() can get correct result 313 * using current root, then we can move all expensive backref walk out of 314 * transaction committing, but not now as qgroup accounting will be wrong again. 315 */ 316 int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans, 317 struct btrfs_qgroup_extent_record *qrecord); 318 319 /* 320 * Inform qgroup to trace one dirty extent, specified by @bytenr and 321 * @num_bytes. 322 * So qgroup can account it at commit trans time. 323 * 324 * Better encapsulated version, with memory allocation and backref walk for 325 * commit roots. 326 * So this can sleep. 327 * 328 * Return 0 if the operation is done. 329 * Return <0 for error, like memory allocation failure or invalid parameter 330 * (NULL trans) 331 */ 332 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr, 333 u64 num_bytes); 334 335 /* 336 * Inform qgroup to trace all leaf items of data 337 * 338 * Return 0 for success 339 * Return <0 for error(ENOMEM) 340 */ 341 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans, 342 struct extent_buffer *eb); 343 /* 344 * Inform qgroup to trace a whole subtree, including all its child tree 345 * blocks and data. 346 * The root tree block is specified by @root_eb. 347 * 348 * Normally used by relocation(tree block swap) and subvolume deletion. 349 * 350 * Return 0 for success 351 * Return <0 for error(ENOMEM or tree search error) 352 */ 353 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, 354 struct extent_buffer *root_eb, 355 u64 root_gen, int root_level); 356 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 357 u64 num_bytes, struct ulist *old_roots, 358 struct ulist *new_roots); 359 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans); 360 int btrfs_run_qgroups(struct btrfs_trans_handle *trans); 361 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid, 362 u64 objectid, struct btrfs_qgroup_inherit *inherit); 363 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info, 364 u64 ref_root, u64 num_bytes, 365 enum btrfs_qgroup_rsv_type type); 366 367 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 368 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid, 369 u64 rfer, u64 excl); 370 #endif 371 372 /* New io_tree based accurate qgroup reserve API */ 373 int btrfs_qgroup_reserve_data(struct btrfs_inode *inode, 374 struct extent_changeset **reserved, u64 start, u64 len); 375 int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len, u64 *released); 376 int btrfs_qgroup_free_data(struct btrfs_inode *inode, 377 struct extent_changeset *reserved, u64 start, 378 u64 len, u64 *freed); 379 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, 380 enum btrfs_qgroup_rsv_type type, bool enforce); 381 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, 382 enum btrfs_qgroup_rsv_type type, bool enforce, 383 bool noflush); 384 /* Reserve metadata space for pertrans and prealloc type */ 385 static inline int btrfs_qgroup_reserve_meta_pertrans(struct btrfs_root *root, 386 int num_bytes, bool enforce) 387 { 388 return __btrfs_qgroup_reserve_meta(root, num_bytes, 389 BTRFS_QGROUP_RSV_META_PERTRANS, 390 enforce, false); 391 } 392 static inline int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root, 393 int num_bytes, bool enforce, 394 bool noflush) 395 { 396 return __btrfs_qgroup_reserve_meta(root, num_bytes, 397 BTRFS_QGROUP_RSV_META_PREALLOC, 398 enforce, noflush); 399 } 400 401 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes, 402 enum btrfs_qgroup_rsv_type type); 403 404 /* Free per-transaction meta reservation for error handling */ 405 static inline void btrfs_qgroup_free_meta_pertrans(struct btrfs_root *root, 406 int num_bytes) 407 { 408 __btrfs_qgroup_free_meta(root, num_bytes, 409 BTRFS_QGROUP_RSV_META_PERTRANS); 410 } 411 412 /* Pre-allocated meta reservation can be freed at need */ 413 static inline void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root, 414 int num_bytes) 415 { 416 __btrfs_qgroup_free_meta(root, num_bytes, 417 BTRFS_QGROUP_RSV_META_PREALLOC); 418 } 419 420 /* 421 * Per-transaction meta reservation should be all freed at transaction commit 422 * time 423 */ 424 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root); 425 426 /* 427 * Convert @num_bytes of META_PREALLOCATED reservation to META_PERTRANS. 428 * 429 * This is called when preallocated meta reservation needs to be used. 430 * Normally after btrfs_join_transaction() call. 431 */ 432 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes); 433 434 void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode); 435 436 /* btrfs_qgroup_swapped_blocks related functions */ 437 void btrfs_qgroup_init_swapped_blocks( 438 struct btrfs_qgroup_swapped_blocks *swapped_blocks); 439 440 void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root); 441 int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans, 442 struct btrfs_root *subvol_root, 443 struct btrfs_block_group *bg, 444 struct extent_buffer *subvol_parent, int subvol_slot, 445 struct extent_buffer *reloc_parent, int reloc_slot, 446 u64 last_snapshot); 447 int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans, 448 struct btrfs_root *root, struct extent_buffer *eb); 449 void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans); 450 bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info); 451 452 #endif 453