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
16struct extent_buffer;
17struct extent_changeset;
18struct btrfs_delayed_extent_op;
19struct btrfs_fs_info;
20struct btrfs_root;
21struct btrfs_ioctl_quota_ctl_args;
22struct btrfs_trans_handle;
23struct btrfs_delayed_ref_root;
24struct btrfs_inode;
25struct btrfs_transaction;
26struct btrfs_block_group;
27struct btrfs_qgroup_swapped_blocks;
28
29/*
30 * Btrfs qgroup overview
31 *
32 * Btrfs qgroup splits into 3 main part:
33 * 1) Reserve
34 * Reserve metadata/data space for incoming operations
35 * Affect how qgroup limit works
36 *
37 * 2) Trace
38 * Tell btrfs qgroup to trace dirty extents.
39 *
40 * Dirty extents including:
41 * - Newly allocated extents
42 * - Extents going to be deleted (in this trans)
43 * - Extents whose owner is going to be modified
44 *
45 * This is the main part affects whether qgroup numbers will stay
46 * consistent.
47 * Btrfs qgroup can trace clean extents and won't cause any problem,
48 * but it will consume extra CPU time, it should be avoided if possible.
49 *
50 * 3) Account
51 * Btrfs qgroup will updates its numbers, based on dirty extents traced
52 * in previous step.
53 *
54 * Normally at qgroup rescan and transaction commit time.
55 */
56
57/*
58 * Special performance optimization for balance.
59 *
60 * For balance, we need to swap subtree of subvolume and reloc trees.
61 * In theory, we need to trace all subtree blocks of both subvolume and reloc
62 * trees, since their owner has changed during such swap.
63 *
64 * However since balance has ensured that both subtrees are containing the
65 * same contents and have the same tree structures, such swap won't cause
66 * qgroup number change.
67 *
68 * But there is a race window between subtree swap and transaction commit,
69 * during that window, if we increase/decrease tree level or merge/split tree
70 * blocks, we still need to trace the original subtrees.
71 *
72 * So for balance, we use a delayed subtree tracing, whose workflow is:
73 *
74 * 1) Record the subtree root block get swapped.
75 *
76 * During subtree swap:
77 * O = Old tree blocks
78 * N = New tree blocks
79 * reloc tree subvolume tree X
80 * Root Root
81 * / \ / \
82 * NA OB OA OB
83 * / | | \ / | | \
84 * NC ND OE OF OC OD OE OF
85 *
86 * In this case, NA and OA are going to be swapped, record (NA, OA) into
87 * subvolume tree X.
88 *
89 * 2) After subtree swap.
90 * reloc tree subvolume tree X
91 * Root Root
92 * / \ / \
93 * OA OB NA OB
94 * / | | \ / | | \
95 * OC OD OE OF NC ND OE OF
96 *
97 * 3a) COW happens for OB
98 * If we are going to COW tree block OB, we check OB's bytenr against
99 * tree X's swapped_blocks structure.
100 * If it doesn't fit any, nothing will happen.
101 *
102 * 3b) COW happens for NA
103 * Check NA's bytenr against tree X's swapped_blocks, and get a hit.
104 * Then we do subtree scan on both subtrees OA and NA.
105 * Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).
106 *
107 * Then no matter what we do to subvolume tree X, qgroup numbers will
108 * still be correct.
109 * Then NA's record gets removed from X's swapped_blocks.
110 *
111 * 4) Transaction commit
112 * Any record in X's swapped_blocks gets removed, since there is no
113 * modification to the swapped subtrees, no need to trigger heavy qgroup
114 * subtree rescan for them.
115 */
116
117/*
118 * These flags share the flags field of the btrfs_qgroup_status_item with the
119 * persisted flags defined in btrfs_tree.h.
120 *
121 * To minimize the chance of collision with new persisted status flags, these
122 * count backwards from the MSB.
123 */
124#define BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN (1ULL << 63)
125#define BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING (1ULL << 62)
126
127#define BTRFS_QGROUP_DROP_SUBTREE_THRES_DEFAULT (3)
128
129/*
130 * Record a dirty extent, and info qgroup to update quota on it
131 */
132struct btrfs_qgroup_extent_record {
133 /*
134 * The bytenr of the extent is given by its index in the dirty_extents
135 * xarray of struct btrfs_delayed_ref_root left shifted by
136 * fs_info->sectorsize_bits.
137 */
138
139 u64 num_bytes;
140
141 /*
142 * For qgroup reserved data space freeing.
143 *
144 * @data_rsv_refroot and @data_rsv will be recorded after
145 * BTRFS_ADD_DELAYED_EXTENT is called.
146 * And will be used to free reserved qgroup space at
147 * transaction commit time.
148 */
149 u32 data_rsv; /* reserved data space needs to be freed */
150 u64 data_rsv_refroot; /* which root the reserved data belongs to */
151 struct ulist *old_roots;
152};
153
154struct btrfs_qgroup_swapped_block {
155 struct rb_node node;
156
157 int level;
158 bool trace_leaf;
159
160 /* bytenr/generation of the tree block in subvolume tree after swap */
161 u64 subvol_bytenr;
162 u64 subvol_generation;
163
164 /* bytenr/generation of the tree block in reloc tree after swap */
165 u64 reloc_bytenr;
166 u64 reloc_generation;
167
168 u64 last_snapshot;
169 struct btrfs_key first_key;
170};
171
172/*
173 * Qgroup reservation types:
174 *
175 * DATA:
176 * space reserved for data
177 *
178 * META_PERTRANS:
179 * Space reserved for metadata (per-transaction)
180 * Due to the fact that qgroup data is only updated at transaction commit
181 * time, reserved space for metadata must be kept until transaction
182 * commits.
183 * Any metadata reserved that are used in btrfs_start_transaction() should
184 * be of this type.
185 *
186 * META_PREALLOC:
187 * There are cases where metadata space is reserved before starting
188 * transaction, and then btrfs_join_transaction() to get a trans handle.
189 * Any metadata reserved for such usage should be of this type.
190 * And after join_transaction() part (or all) of such reservation should
191 * be converted into META_PERTRANS.
192 */
193enum btrfs_qgroup_rsv_type {
194 BTRFS_QGROUP_RSV_DATA,
195 BTRFS_QGROUP_RSV_META_PERTRANS,
196 BTRFS_QGROUP_RSV_META_PREALLOC,
197 BTRFS_QGROUP_RSV_LAST,
198};
199
200/*
201 * Represents how many bytes we have reserved for this qgroup.
202 *
203 * Each type should have different reservation behavior.
204 * E.g, data follows its io_tree flag modification, while
205 * *currently* meta is just reserve-and-clear during transaction.
206 *
207 * TODO: Add new type for reservation which can survive transaction commit.
208 * Current metadata reservation behavior is not suitable for such case.
209 */
210struct btrfs_qgroup_rsv {
211 u64 values[BTRFS_QGROUP_RSV_LAST];
212};
213
214/*
215 * one struct for each qgroup, organized in fs_info->qgroup_tree.
216 */
217struct btrfs_qgroup {
218 u64 qgroupid;
219
220 /*
221 * state
222 */
223 u64 rfer; /* referenced */
224 u64 rfer_cmpr; /* referenced compressed */
225 u64 excl; /* exclusive */
226 u64 excl_cmpr; /* exclusive compressed */
227
228 /*
229 * limits
230 */
231 u64 lim_flags; /* which limits are set */
232 u64 max_rfer;
233 u64 max_excl;
234 u64 rsv_rfer;
235 u64 rsv_excl;
236
237 /*
238 * reservation tracking
239 */
240 struct btrfs_qgroup_rsv rsv;
241
242 /*
243 * lists
244 */
245 struct list_head groups; /* groups this group is member of */
246 struct list_head members; /* groups that are members of this group */
247 struct list_head dirty; /* dirty groups */
248
249 /*
250 * For qgroup iteration usage.
251 *
252 * The iteration list should always be empty until qgroup_iterator_add()
253 * is called. And should be reset to empty after the iteration is
254 * finished.
255 */
256 struct list_head iterator;
257
258 /*
259 * For nested iterator usage.
260 *
261 * Here we support at most one level of nested iterator calls like:
262 *
263 * LIST_HEAD(all_qgroups);
264 * {
265 * LIST_HEAD(local_qgroups);
266 * qgroup_iterator_add(local_qgroups, qg);
267 * qgroup_iterator_nested_add(all_qgroups, qg);
268 * do_some_work(local_qgroups);
269 * qgroup_iterator_clean(local_qgroups);
270 * }
271 * do_some_work(all_qgroups);
272 * qgroup_iterator_nested_clean(all_qgroups);
273 */
274 struct list_head nested_iterator;
275 struct rb_node node; /* tree of qgroups */
276
277 /*
278 * temp variables for accounting operations
279 * Refer to qgroup_shared_accounting() for details.
280 */
281 u64 old_refcnt;
282 u64 new_refcnt;
283
284 /*
285 * Sysfs kobjectid
286 */
287 struct kobject kobj;
288};
289
290/* Glue structure to represent the relations between qgroups. */
291struct btrfs_qgroup_list {
292 struct list_head next_group;
293 struct list_head next_member;
294 struct btrfs_qgroup *group;
295 struct btrfs_qgroup *member;
296};
297
298struct btrfs_squota_delta {
299 /* The fstree root this delta counts against. */
300 u64 root;
301 /* The number of bytes in the extent being counted. */
302 u64 num_bytes;
303 /* The generation the extent was created in. */
304 u64 generation;
305 /* Whether we are using or freeing the extent. */
306 bool is_inc;
307 /* Whether the extent is data or metadata. */
308 bool is_data;
309};
310
311static inline u64 btrfs_qgroup_subvolid(u64 qgroupid)
312{
313 return (qgroupid & ((1ULL << BTRFS_QGROUP_LEVEL_SHIFT) - 1));
314}
315
316/*
317 * For qgroup event trace points only
318 */
319enum {
320 ENUM_BIT(QGROUP_RESERVE),
321 ENUM_BIT(QGROUP_RELEASE),
322 ENUM_BIT(QGROUP_FREE),
323};
324
325enum btrfs_qgroup_mode {
326 BTRFS_QGROUP_MODE_DISABLED,
327 BTRFS_QGROUP_MODE_FULL,
328 BTRFS_QGROUP_MODE_SIMPLE
329};
330
331enum btrfs_qgroup_mode btrfs_qgroup_mode(const struct btrfs_fs_info *fs_info);
332bool btrfs_qgroup_enabled(const struct btrfs_fs_info *fs_info);
333bool btrfs_qgroup_full_accounting(const struct btrfs_fs_info *fs_info);
334int btrfs_quota_enable(struct btrfs_fs_info *fs_info,
335 struct btrfs_ioctl_quota_ctl_args *quota_ctl_args);
336int btrfs_quota_disable(struct btrfs_fs_info *fs_info);
337int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
338void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
339int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
340 bool interruptible);
341int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, u64 dst,
342 struct btrfs_qgroup_list *prealloc);
343int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
344 u64 dst);
345int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
346int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
347int btrfs_qgroup_cleanup_dropped_subvolume(struct btrfs_fs_info *fs_info, u64 subvolid);
348int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
349 struct btrfs_qgroup_limit *limit);
350int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
351void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
352
353int btrfs_qgroup_trace_extent_nolock(
354 struct btrfs_fs_info *fs_info,
355 struct btrfs_delayed_ref_root *delayed_refs,
356 struct btrfs_qgroup_extent_record *record,
357 u64 bytenr);
358int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
359 struct btrfs_qgroup_extent_record *qrecord,
360 u64 bytenr);
361int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
362 u64 num_bytes);
363int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
364 struct extent_buffer *eb);
365int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
366 struct extent_buffer *root_eb,
367 u64 root_gen, int root_level);
368int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
369 u64 num_bytes, struct ulist *old_roots,
370 struct ulist *new_roots);
371int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans);
372int btrfs_run_qgroups(struct btrfs_trans_handle *trans);
373int btrfs_qgroup_check_inherit(struct btrfs_fs_info *fs_info,
374 struct btrfs_qgroup_inherit *inherit,
375 size_t size);
376int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
377 u64 objectid, u64 inode_rootid,
378 struct btrfs_qgroup_inherit *inherit);
379void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
380 u64 ref_root, u64 num_bytes,
381 enum btrfs_qgroup_rsv_type type);
382
383#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
384int btrfs_verify_qgroup_counts(const struct btrfs_fs_info *fs_info, u64 qgroupid,
385 u64 rfer, u64 excl);
386#endif
387
388/* New io_tree based accurate qgroup reserve API */
389int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
390 struct extent_changeset **reserved, u64 start, u64 len);
391int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len, u64 *released);
392int btrfs_qgroup_free_data(struct btrfs_inode *inode,
393 struct extent_changeset *reserved, u64 start,
394 u64 len, u64 *freed);
395int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
396 enum btrfs_qgroup_rsv_type type, bool enforce);
397int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
398 enum btrfs_qgroup_rsv_type type, bool enforce,
399 bool noflush);
400/* Reserve metadata space for pertrans and prealloc type */
401static inline int btrfs_qgroup_reserve_meta_pertrans(struct btrfs_root *root,
402 int num_bytes, bool enforce)
403{
404 return __btrfs_qgroup_reserve_meta(root, num_bytes,
405 type: BTRFS_QGROUP_RSV_META_PERTRANS,
406 enforce, noflush: false);
407}
408static inline int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root,
409 int num_bytes, bool enforce,
410 bool noflush)
411{
412 return __btrfs_qgroup_reserve_meta(root, num_bytes,
413 type: BTRFS_QGROUP_RSV_META_PREALLOC,
414 enforce, noflush);
415}
416
417void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
418 enum btrfs_qgroup_rsv_type type);
419
420/* Free per-transaction meta reservation for error handling */
421static inline void btrfs_qgroup_free_meta_pertrans(struct btrfs_root *root,
422 int num_bytes)
423{
424 __btrfs_qgroup_free_meta(root, num_bytes,
425 type: BTRFS_QGROUP_RSV_META_PERTRANS);
426}
427
428/* Pre-allocated meta reservation can be freed at need */
429static inline void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root,
430 int num_bytes)
431{
432 __btrfs_qgroup_free_meta(root, num_bytes,
433 type: BTRFS_QGROUP_RSV_META_PREALLOC);
434}
435
436void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root);
437void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes);
438void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode);
439
440/* btrfs_qgroup_swapped_blocks related functions */
441void btrfs_qgroup_init_swapped_blocks(
442 struct btrfs_qgroup_swapped_blocks *swapped_blocks);
443
444void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root);
445int btrfs_qgroup_add_swapped_blocks(struct btrfs_root *subvol_root,
446 struct btrfs_block_group *bg,
447 struct extent_buffer *subvol_parent, int subvol_slot,
448 struct extent_buffer *reloc_parent, int reloc_slot,
449 u64 last_snapshot);
450int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
451 struct btrfs_root *root, struct extent_buffer *eb);
452void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans);
453bool btrfs_check_quota_leak(const struct btrfs_fs_info *fs_info);
454int btrfs_record_squota_delta(struct btrfs_fs_info *fs_info,
455 const struct btrfs_squota_delta *delta);
456
457#endif
458

source code of linux/fs/btrfs/qgroup.h