fs/btrfs/qgroup.h

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