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