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 /* 104 * Record a dirty extent, and info qgroup to update quota on it 105 * TODO: Use kmem cache to alloc it. 106 */ 107 struct btrfs_qgroup_extent_record { 108 struct rb_node node; 109 u64 bytenr; 110 u64 num_bytes; 111 112 /* 113 * For qgroup reserved data space freeing. 114 * 115 * @data_rsv_refroot and @data_rsv will be recorded after 116 * BTRFS_ADD_DELAYED_EXTENT is called. 117 * And will be used to free reserved qgroup space at 118 * transaction commit time. 119 */ 120 u32 data_rsv; /* reserved data space needs to be freed */ 121 u64 data_rsv_refroot; /* which root the reserved data belongs to */ 122 struct ulist *old_roots; 123 }; 124 125 struct btrfs_qgroup_swapped_block { 126 struct rb_node node; 127 128 int level; 129 bool trace_leaf; 130 131 /* bytenr/generation of the tree block in subvolume tree after swap */ 132 u64 subvol_bytenr; 133 u64 subvol_generation; 134 135 /* bytenr/generation of the tree block in reloc tree after swap */ 136 u64 reloc_bytenr; 137 u64 reloc_generation; 138 139 u64 last_snapshot; 140 struct btrfs_key first_key; 141 }; 142 143 /* 144 * Qgroup reservation types: 145 * 146 * DATA: 147 * space reserved for data 148 * 149 * META_PERTRANS: 150 * Space reserved for metadata (per-transaction) 151 * Due to the fact that qgroup data is only updated at transaction commit 152 * time, reserved space for metadata must be kept until transaction 153 * commits. 154 * Any metadata reserved that are used in btrfs_start_transaction() should 155 * be of this type. 156 * 157 * META_PREALLOC: 158 * There are cases where metadata space is reserved before starting 159 * transaction, and then btrfs_join_transaction() to get a trans handle. 160 * Any metadata reserved for such usage should be of this type. 161 * And after join_transaction() part (or all) of such reservation should 162 * be converted into META_PERTRANS. 163 */ 164 enum btrfs_qgroup_rsv_type { 165 BTRFS_QGROUP_RSV_DATA, 166 BTRFS_QGROUP_RSV_META_PERTRANS, 167 BTRFS_QGROUP_RSV_META_PREALLOC, 168 BTRFS_QGROUP_RSV_LAST, 169 }; 170 171 /* 172 * Represents how many bytes we have reserved for this qgroup. 173 * 174 * Each type should have different reservation behavior. 175 * E.g, data follows its io_tree flag modification, while 176 * *currently* meta is just reserve-and-clear during transaction. 177 * 178 * TODO: Add new type for reservation which can survive transaction commit. 179 * Current metadata reservation behavior is not suitable for such case. 180 */ 181 struct btrfs_qgroup_rsv { 182 u64 values[BTRFS_QGROUP_RSV_LAST]; 183 }; 184 185 /* 186 * one struct for each qgroup, organized in fs_info->qgroup_tree. 187 */ 188 struct btrfs_qgroup { 189 u64 qgroupid; 190 191 /* 192 * state 193 */ 194 u64 rfer; /* referenced */ 195 u64 rfer_cmpr; /* referenced compressed */ 196 u64 excl; /* exclusive */ 197 u64 excl_cmpr; /* exclusive compressed */ 198 199 /* 200 * limits 201 */ 202 u64 lim_flags; /* which limits are set */ 203 u64 max_rfer; 204 u64 max_excl; 205 u64 rsv_rfer; 206 u64 rsv_excl; 207 208 /* 209 * reservation tracking 210 */ 211 struct btrfs_qgroup_rsv rsv; 212 213 /* 214 * lists 215 */ 216 struct list_head groups; /* groups this group is member of */ 217 struct list_head members; /* groups that are members of this group */ 218 struct list_head dirty; /* dirty groups */ 219 struct rb_node node; /* tree of qgroups */ 220 221 /* 222 * temp variables for accounting operations 223 * Refer to qgroup_shared_accounting() for details. 224 */ 225 u64 old_refcnt; 226 u64 new_refcnt; 227 228 /* 229 * Sysfs kobjectid 230 */ 231 struct kobject kobj; 232 }; 233 234 static inline u64 btrfs_qgroup_subvolid(u64 qgroupid) 235 { 236 return (qgroupid & ((1ULL << BTRFS_QGROUP_LEVEL_SHIFT) - 1)); 237 } 238 239 /* 240 * For qgroup event trace points only 241 */ 242 #define QGROUP_RESERVE (1<<0) 243 #define QGROUP_RELEASE (1<<1) 244 #define QGROUP_FREE (1<<2) 245 246 int btrfs_quota_enable(struct btrfs_fs_info *fs_info); 247 int btrfs_quota_disable(struct btrfs_fs_info *fs_info); 248 int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info); 249 void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info); 250 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info, 251 bool interruptible); 252 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, 253 u64 dst); 254 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, 255 u64 dst); 256 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid); 257 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid); 258 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid, 259 struct btrfs_qgroup_limit *limit); 260 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info); 261 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info); 262 struct btrfs_delayed_extent_op; 263 264 /* 265 * Inform qgroup to trace one dirty extent, its info is recorded in @record. 266 * So qgroup can account it at transaction committing time. 267 * 268 * No lock version, caller must acquire delayed ref lock and allocated memory, 269 * then call btrfs_qgroup_trace_extent_post() after exiting lock context. 270 * 271 * Return 0 for success insert 272 * Return >0 for existing record, caller can free @record safely. 273 * Error is not possible 274 */ 275 int btrfs_qgroup_trace_extent_nolock( 276 struct btrfs_fs_info *fs_info, 277 struct btrfs_delayed_ref_root *delayed_refs, 278 struct btrfs_qgroup_extent_record *record); 279 280 /* 281 * Post handler after qgroup_trace_extent_nolock(). 282 * 283 * NOTE: Current qgroup does the expensive backref walk at transaction 284 * committing time with TRANS_STATE_COMMIT_DOING, this blocks incoming 285 * new transaction. 286 * This is designed to allow btrfs_find_all_roots() to get correct new_roots 287 * result. 288 * 289 * However for old_roots there is no need to do backref walk at that time, 290 * since we search commit roots to walk backref and result will always be 291 * correct. 292 * 293 * Due to the nature of no lock version, we can't do backref there. 294 * So we must call btrfs_qgroup_trace_extent_post() after exiting 295 * spinlock context. 296 * 297 * TODO: If we can fix and prove btrfs_find_all_roots() can get correct result 298 * using current root, then we can move all expensive backref walk out of 299 * transaction committing, but not now as qgroup accounting will be wrong again. 300 */ 301 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info, 302 struct btrfs_qgroup_extent_record *qrecord); 303 304 /* 305 * Inform qgroup to trace one dirty extent, specified by @bytenr and 306 * @num_bytes. 307 * So qgroup can account it at commit trans time. 308 * 309 * Better encapsulated version, with memory allocation and backref walk for 310 * commit roots. 311 * So this can sleep. 312 * 313 * Return 0 if the operation is done. 314 * Return <0 for error, like memory allocation failure or invalid parameter 315 * (NULL trans) 316 */ 317 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr, 318 u64 num_bytes, gfp_t gfp_flag); 319 320 /* 321 * Inform qgroup to trace all leaf items of data 322 * 323 * Return 0 for success 324 * Return <0 for error(ENOMEM) 325 */ 326 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans, 327 struct extent_buffer *eb); 328 /* 329 * Inform qgroup to trace a whole subtree, including all its child tree 330 * blocks and data. 331 * The root tree block is specified by @root_eb. 332 * 333 * Normally used by relocation(tree block swap) and subvolume deletion. 334 * 335 * Return 0 for success 336 * Return <0 for error(ENOMEM or tree search error) 337 */ 338 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, 339 struct extent_buffer *root_eb, 340 u64 root_gen, int root_level); 341 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 342 u64 num_bytes, struct ulist *old_roots, 343 struct ulist *new_roots); 344 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans); 345 int btrfs_run_qgroups(struct btrfs_trans_handle *trans); 346 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid, 347 u64 objectid, struct btrfs_qgroup_inherit *inherit); 348 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info, 349 u64 ref_root, u64 num_bytes, 350 enum btrfs_qgroup_rsv_type type); 351 352 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 353 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid, 354 u64 rfer, u64 excl); 355 #endif 356 357 /* New io_tree based accurate qgroup reserve API */ 358 int btrfs_qgroup_reserve_data(struct btrfs_inode *inode, 359 struct extent_changeset **reserved, u64 start, u64 len); 360 int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len); 361 int btrfs_qgroup_free_data(struct btrfs_inode *inode, 362 struct extent_changeset *reserved, u64 start, 363 u64 len); 364 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, 365 enum btrfs_qgroup_rsv_type type, bool enforce); 366 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, 367 enum btrfs_qgroup_rsv_type type, bool enforce); 368 /* Reserve metadata space for pertrans and prealloc type */ 369 static inline int btrfs_qgroup_reserve_meta_pertrans(struct btrfs_root *root, 370 int num_bytes, bool enforce) 371 { 372 return __btrfs_qgroup_reserve_meta(root, num_bytes, 373 BTRFS_QGROUP_RSV_META_PERTRANS, enforce); 374 } 375 static inline int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root, 376 int num_bytes, bool enforce) 377 { 378 return __btrfs_qgroup_reserve_meta(root, num_bytes, 379 BTRFS_QGROUP_RSV_META_PREALLOC, enforce); 380 } 381 382 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes, 383 enum btrfs_qgroup_rsv_type type); 384 385 /* Free per-transaction meta reservation for error handling */ 386 static inline void btrfs_qgroup_free_meta_pertrans(struct btrfs_root *root, 387 int num_bytes) 388 { 389 __btrfs_qgroup_free_meta(root, num_bytes, 390 BTRFS_QGROUP_RSV_META_PERTRANS); 391 } 392 393 /* Pre-allocated meta reservation can be freed at need */ 394 static inline void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root, 395 int num_bytes) 396 { 397 __btrfs_qgroup_free_meta(root, num_bytes, 398 BTRFS_QGROUP_RSV_META_PREALLOC); 399 } 400 401 /* 402 * Per-transaction meta reservation should be all freed at transaction commit 403 * time 404 */ 405 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root); 406 407 /* 408 * Convert @num_bytes of META_PREALLOCATED reservation to META_PERTRANS. 409 * 410 * This is called when preallocated meta reservation needs to be used. 411 * Normally after btrfs_join_transaction() call. 412 */ 413 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes); 414 415 void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode); 416 417 /* btrfs_qgroup_swapped_blocks related functions */ 418 void btrfs_qgroup_init_swapped_blocks( 419 struct btrfs_qgroup_swapped_blocks *swapped_blocks); 420 421 void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root); 422 int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans, 423 struct btrfs_root *subvol_root, 424 struct btrfs_block_group *bg, 425 struct extent_buffer *subvol_parent, int subvol_slot, 426 struct extent_buffer *reloc_parent, int reloc_slot, 427 u64 last_snapshot); 428 int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans, 429 struct btrfs_root *root, struct extent_buffer *eb); 430 void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans); 431 bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info); 432 433 #endif 434