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 "ulist.h"
  10 #include "delayed-ref.h"
  11
  12 /*
  13  * Btrfs qgroup overview
  14  *
  15  * Btrfs qgroup splits into 3 main part:
  16  * 1) Reserve
  17  *    Reserve metadata/data space for incoming operations
  18  *    Affect how qgroup limit works
  19  *
  20  * 2) Trace
  21  *    Tell btrfs qgroup to trace dirty extents.
  22  *
  23  *    Dirty extents including:
  24  *    - Newly allocated extents
  25  *    - Extents going to be deleted (in this trans)
  26  *    - Extents whose owner is going to be modified
  27  *
  28  *    This is the main part affects whether qgroup numbers will stay
  29  *    consistent.
  30  *    Btrfs qgroup can trace clean extents and won't cause any problem,
  31  *    but it will consume extra CPU time, it should be avoided if possible.
  32  *
  33  * 3) Account
  34  *    Btrfs qgroup will updates its numbers, based on dirty extents traced
  35  *    in previous step.
  36  *
  37  *    Normally at qgroup rescan and transaction commit time.
  38  */
  39
  40 /*
  41  * Record a dirty extent, and info qgroup to update quota on it
  42  * TODO: Use kmem cache to alloc it.
  43  */
  44 struct btrfs_qgroup_extent_record {
  45         struct rb_node node;
  46         u64 bytenr;
  47         u64 num_bytes;
  48         struct ulist *old_roots;
  49 };
  50
  51 /*
  52  * Qgroup reservation types:
  53  *
  54  * DATA:
  55  *      space reserved for data
  56  *
  57  * META_PERTRANS:
  58  *      Space reserved for metadata (per-transaction)
  59  *      Due to the fact that qgroup data is only updated at transaction commit
  60  *      time, reserved space for metadata must be kept until transaction
  61  *      commits.
  62  *      Any metadata reserved that are used in btrfs_start_transaction() should
  63  *      be of this type.
  64  *
  65  * META_PREALLOC:
  66  *      There are cases where metadata space is reserved before starting
  67  *      transaction, and then btrfs_join_transaction() to get a trans handle.
  68  *      Any metadata reserved for such usage should be of this type.
  69  *      And after join_transaction() part (or all) of such reservation should
  70  *      be converted into META_PERTRANS.
  71  */
  72 enum btrfs_qgroup_rsv_type {
  73         BTRFS_QGROUP_RSV_DATA = 0,
  74         BTRFS_QGROUP_RSV_META_PERTRANS,
  75         BTRFS_QGROUP_RSV_META_PREALLOC,
  76         BTRFS_QGROUP_RSV_LAST,
  77 };
  78
  79 /*
  80  * Represents how many bytes we have reserved for this qgroup.
  81  *
  82  * Each type should have different reservation behavior.
  83  * E.g, data follows its io_tree flag modification, while
  84  * *currently* meta is just reserve-and-clear during transcation.
  85  *
  86  * TODO: Add new type for reservation which can survive transaction commit.
  87  * Currect metadata reservation behavior is not suitable for such case.
  88  */
  89 struct btrfs_qgroup_rsv {
  90         u64 values[BTRFS_QGROUP_RSV_LAST];
  91 };
  92
  93 /*
  94  * one struct for each qgroup, organized in fs_info->qgroup_tree.
  95  */
  96 struct btrfs_qgroup {
  97         u64 qgroupid;
  98
  99         /*
 100          * state
 101          */
 102         u64 rfer;       /* referenced */
 103         u64 rfer_cmpr;  /* referenced compressed */
 104         u64 excl;       /* exclusive */
 105         u64 excl_cmpr;  /* exclusive compressed */
 106
 107         /*
 108          * limits
 109          */
 110         u64 lim_flags;  /* which limits are set */
 111         u64 max_rfer;
 112         u64 max_excl;
 113         u64 rsv_rfer;
 114         u64 rsv_excl;
 115
 116         /*
 117          * reservation tracking
 118          */
 119         struct btrfs_qgroup_rsv rsv;
 120
 121         /*
 122          * lists
 123          */
 124         struct list_head groups;  /* groups this group is member of */
 125         struct list_head members; /* groups that are members of this group */
 126         struct list_head dirty;   /* dirty groups */
 127         struct rb_node node;      /* tree of qgroups */
 128
 129         /*
 130          * temp variables for accounting operations
 131          * Refer to qgroup_shared_accounting() for details.
 132          */
 133         u64 old_refcnt;
 134         u64 new_refcnt;
 135 };
 136
 137 /*
 138  * For qgroup event trace points only
 139  */
 140 #define QGROUP_RESERVE          (1<<0)
 141 #define QGROUP_RELEASE          (1<<1)
 142 #define QGROUP_FREE             (1<<2)
 143
 144 int btrfs_quota_enable(struct btrfs_fs_info *fs_info);
 145 int btrfs_quota_disable(struct btrfs_fs_info *fs_info);
 146 int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
 147 void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
 148 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
 149                                      bool interruptible);
 150 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
 151                               u64 dst);
 152 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
 153                               u64 dst);
 154 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
 155 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
 156 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
 157                        struct btrfs_qgroup_limit *limit);
 158 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
 159 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
 160 struct btrfs_delayed_extent_op;
 161
 162 /*
 163  * Inform qgroup to trace one dirty extent, its info is recorded in @record.
 164  * So qgroup can account it at transaction committing time.
 165  *
 166  * No lock version, caller must acquire delayed ref lock and allocated memory,
 167  * then call btrfs_qgroup_trace_extent_post() after exiting lock context.
 168  *
 169  * Return 0 for success insert
 170  * Return >0 for existing record, caller can free @record safely.
 171  * Error is not possible
 172  */
 173 int btrfs_qgroup_trace_extent_nolock(
 174                 struct btrfs_fs_info *fs_info,
 175                 struct btrfs_delayed_ref_root *delayed_refs,
 176                 struct btrfs_qgroup_extent_record *record);
 177
 178 /*
 179  * Post handler after qgroup_trace_extent_nolock().
 180  *
 181  * NOTE: Current qgroup does the expensive backref walk at transaction
 182  * committing time with TRANS_STATE_COMMIT_DOING, this blocks incoming
 183  * new transaction.
 184  * This is designed to allow btrfs_find_all_roots() to get correct new_roots
 185  * result.
 186  *
 187  * However for old_roots there is no need to do backref walk at that time,
 188  * since we search commit roots to walk backref and result will always be
 189  * correct.
 190  *
 191  * Due to the nature of no lock version, we can't do backref there.
 192  * So we must call btrfs_qgroup_trace_extent_post() after exiting
 193  * spinlock context.
 194  *
 195  * TODO: If we can fix and prove btrfs_find_all_roots() can get correct result
 196  * using current root, then we can move all expensive backref walk out of
 197  * transaction committing, but not now as qgroup accounting will be wrong again.
 198  */
 199 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
 200                                    struct btrfs_qgroup_extent_record *qrecord);
 201
 202 /*
 203  * Inform qgroup to trace one dirty extent, specified by @bytenr and
 204  * @num_bytes.
 205  * So qgroup can account it at commit trans time.
 206  *
 207  * Better encapsulated version, with memory allocation and backref walk for
 208  * commit roots.
 209  * So this can sleep.
 210  *
 211  * Return 0 if the operation is done.
 212  * Return <0 for error, like memory allocation failure or invalid parameter
 213  * (NULL trans)
 214  */
 215 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
 216                               u64 num_bytes, gfp_t gfp_flag);
 217
 218 /*
 219  * Inform qgroup to trace all leaf items of data
 220  *
 221  * Return 0 for success
 222  * Return <0 for error(ENOMEM)
 223  */
 224 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
 225                                   struct extent_buffer *eb);
 226 /*
 227  * Inform qgroup to trace a whole subtree, including all its child tree
 228  * blocks and data.
 229  * The root tree block is specified by @root_eb.
 230  *
 231  * Normally used by relocation(tree block swap) and subvolume deletion.
 232  *
 233  * Return 0 for success
 234  * Return <0 for error(ENOMEM or tree search error)
 235  */
 236 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
 237                                struct extent_buffer *root_eb,
 238                                u64 root_gen, int root_level);
 239
 240 int btrfs_qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
 241                                 struct btrfs_block_group_cache *bg_cache,
 242                                 struct extent_buffer *src_parent, int src_slot,
 243                                 struct extent_buffer *dst_parent, int dst_slot,
 244                                 u64 last_snapshot);
 245 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
 246                                 u64 num_bytes, struct ulist *old_roots,
 247                                 struct ulist *new_roots);
 248 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans);
 249 int btrfs_run_qgroups(struct btrfs_trans_handle *trans);
 250 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 251                          u64 objectid, struct btrfs_qgroup_inherit *inherit);
 252 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
 253                                u64 ref_root, u64 num_bytes,
 254                                enum btrfs_qgroup_rsv_type type);
 255 static inline void btrfs_qgroup_free_delayed_ref(struct btrfs_fs_info *fs_info,
 256                                                  u64 ref_root, u64 num_bytes)
 257 {
 258         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 259                 return;
 260         trace_btrfs_qgroup_free_delayed_ref(fs_info, ref_root, num_bytes);
 261         btrfs_qgroup_free_refroot(fs_info, ref_root, num_bytes,
 262                                   BTRFS_QGROUP_RSV_DATA);
 263 }
 264
 265 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 266 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 267                                u64 rfer, u64 excl);
 268 #endif
 269
 270 /* New io_tree based accurate qgroup reserve API */
 271 int btrfs_qgroup_reserve_data(struct inode *inode,
 272                         struct extent_changeset **reserved, u64 start, u64 len);
 273 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len);
 274 int btrfs_qgroup_free_data(struct inode *inode,
 275                         struct extent_changeset *reserved, u64 start, u64 len);
 276
 277 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
 278                                 enum btrfs_qgroup_rsv_type type, bool enforce);
 279 /* Reserve metadata space for pertrans and prealloc type */
 280 static inline int btrfs_qgroup_reserve_meta_pertrans(struct btrfs_root *root,
 281                                 int num_bytes, bool enforce)
 282 {
 283         return __btrfs_qgroup_reserve_meta(root, num_bytes,
 284                         BTRFS_QGROUP_RSV_META_PERTRANS, enforce);
 285 }
 286 static inline int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root,
 287                                 int num_bytes, bool enforce)
 288 {
 289         return __btrfs_qgroup_reserve_meta(root, num_bytes,
 290                         BTRFS_QGROUP_RSV_META_PREALLOC, enforce);
 291 }
 292
 293 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
 294                              enum btrfs_qgroup_rsv_type type);
 295
 296 /* Free per-transaction meta reservation for error handling */
 297 static inline void btrfs_qgroup_free_meta_pertrans(struct btrfs_root *root,
 298                                                    int num_bytes)
 299 {
 300         __btrfs_qgroup_free_meta(root, num_bytes,
 301                         BTRFS_QGROUP_RSV_META_PERTRANS);
 302 }
 303
 304 /* Pre-allocated meta reservation can be freed at need */
 305 static inline void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root,
 306                                                    int num_bytes)
 307 {
 308         __btrfs_qgroup_free_meta(root, num_bytes,
 309                         BTRFS_QGROUP_RSV_META_PREALLOC);
 310 }
 311
 312 /*
 313  * Per-transaction meta reservation should be all freed at transaction commit
 314  * time
 315  */
 316 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root);
 317
 318 /*
 319  * Convert @num_bytes of META_PREALLOCATED reservation to META_PERTRANS.
 320  *
 321  * This is called when preallocated meta reservation needs to be used.
 322  * Normally after btrfs_join_transaction() call.
 323  */
 324 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes);
 325
 326 void btrfs_qgroup_check_reserved_leak(struct inode *inode);
 327
 328 #endif