btrfs: move functions comments from qgroup.h to qgroup.c
[linux-2.6-block.git] / fs / btrfs / qgroup.h
CommitLineData
9888c340 1/* SPDX-License-Identifier: GPL-2.0 */
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2/*
3 * Copyright (C) 2014 Facebook. All rights reserved.
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4 */
5
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6#ifndef BTRFS_QGROUP_H
7#define BTRFS_QGROUP_H
fcebe456 8
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9#include <linux/spinlock.h>
10#include <linux/rbtree.h>
49e5fb46 11#include <linux/kobject.h>
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12#include "ulist.h"
13#include "delayed-ref.h"
e0a8b9a7 14#include "misc.h"
3368d001 15
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16/*
17 * Btrfs qgroup overview
18 *
19 * Btrfs qgroup splits into 3 main part:
20 * 1) Reserve
21 * Reserve metadata/data space for incoming operations
22 * Affect how qgroup limit works
23 *
24 * 2) Trace
25 * Tell btrfs qgroup to trace dirty extents.
26 *
27 * Dirty extents including:
28 * - Newly allocated extents
29 * - Extents going to be deleted (in this trans)
30 * - Extents whose owner is going to be modified
31 *
32 * This is the main part affects whether qgroup numbers will stay
33 * consistent.
34 * Btrfs qgroup can trace clean extents and won't cause any problem,
35 * but it will consume extra CPU time, it should be avoided if possible.
36 *
37 * 3) Account
38 * Btrfs qgroup will updates its numbers, based on dirty extents traced
39 * in previous step.
40 *
41 * Normally at qgroup rescan and transaction commit time.
42 */
43
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44/*
45 * Special performance optimization for balance.
46 *
47 * For balance, we need to swap subtree of subvolume and reloc trees.
48 * In theory, we need to trace all subtree blocks of both subvolume and reloc
49 * trees, since their owner has changed during such swap.
50 *
51 * However since balance has ensured that both subtrees are containing the
52 * same contents and have the same tree structures, such swap won't cause
53 * qgroup number change.
54 *
55 * But there is a race window between subtree swap and transaction commit,
56 * during that window, if we increase/decrease tree level or merge/split tree
57 * blocks, we still need to trace the original subtrees.
58 *
59 * So for balance, we use a delayed subtree tracing, whose workflow is:
60 *
61 * 1) Record the subtree root block get swapped.
62 *
63 * During subtree swap:
64 * O = Old tree blocks
65 * N = New tree blocks
66 * reloc tree subvolume tree X
67 * Root Root
68 * / \ / \
69 * NA OB OA OB
70 * / | | \ / | | \
71 * NC ND OE OF OC OD OE OF
72 *
73 * In this case, NA and OA are going to be swapped, record (NA, OA) into
74 * subvolume tree X.
75 *
76 * 2) After subtree swap.
77 * reloc tree subvolume tree X
78 * Root Root
79 * / \ / \
80 * OA OB NA OB
81 * / | | \ / | | \
82 * OC OD OE OF NC ND OE OF
83 *
84 * 3a) COW happens for OB
85 * If we are going to COW tree block OB, we check OB's bytenr against
86 * tree X's swapped_blocks structure.
87 * If it doesn't fit any, nothing will happen.
88 *
89 * 3b) COW happens for NA
90 * Check NA's bytenr against tree X's swapped_blocks, and get a hit.
91 * Then we do subtree scan on both subtrees OA and NA.
92 * Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).
93 *
94 * Then no matter what we do to subvolume tree X, qgroup numbers will
95 * still be correct.
96 * Then NA's record gets removed from X's swapped_blocks.
97 *
98 * 4) Transaction commit
99 * Any record in X's swapped_blocks gets removed, since there is no
100 * modification to the swapped subtrees, no need to trigger heavy qgroup
101 * subtree rescan for them.
102 */
103
e562a8bd 104#define BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN (1UL << 3)
e15e9f43 105#define BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING (1UL << 4)
e562a8bd 106
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107/*
108 * Record a dirty extent, and info qgroup to update quota on it
109 * TODO: Use kmem cache to alloc it.
110 */
111struct btrfs_qgroup_extent_record {
112 struct rb_node node;
113 u64 bytenr;
114 u64 num_bytes;
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115
116 /*
117 * For qgroup reserved data space freeing.
118 *
119 * @data_rsv_refroot and @data_rsv will be recorded after
120 * BTRFS_ADD_DELAYED_EXTENT is called.
121 * And will be used to free reserved qgroup space at
122 * transaction commit time.
123 */
124 u32 data_rsv; /* reserved data space needs to be freed */
125 u64 data_rsv_refroot; /* which root the reserved data belongs to */
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126 struct ulist *old_roots;
127};
128
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129struct btrfs_qgroup_swapped_block {
130 struct rb_node node;
131
132 int level;
133 bool trace_leaf;
134
135 /* bytenr/generation of the tree block in subvolume tree after swap */
136 u64 subvol_bytenr;
137 u64 subvol_generation;
138
139 /* bytenr/generation of the tree block in reloc tree after swap */
140 u64 reloc_bytenr;
141 u64 reloc_generation;
142
143 u64 last_snapshot;
144 struct btrfs_key first_key;
145};
146
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147/*
148 * Qgroup reservation types:
149 *
150 * DATA:
151 * space reserved for data
152 *
153 * META_PERTRANS:
154 * Space reserved for metadata (per-transaction)
155 * Due to the fact that qgroup data is only updated at transaction commit
156 * time, reserved space for metadata must be kept until transaction
157 * commits.
158 * Any metadata reserved that are used in btrfs_start_transaction() should
159 * be of this type.
160 *
161 * META_PREALLOC:
162 * There are cases where metadata space is reserved before starting
163 * transaction, and then btrfs_join_transaction() to get a trans handle.
164 * Any metadata reserved for such usage should be of this type.
165 * And after join_transaction() part (or all) of such reservation should
166 * be converted into META_PERTRANS.
167 */
d4e5c920 168enum btrfs_qgroup_rsv_type {
bbe339cc 169 BTRFS_QGROUP_RSV_DATA,
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170 BTRFS_QGROUP_RSV_META_PERTRANS,
171 BTRFS_QGROUP_RSV_META_PREALLOC,
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172 BTRFS_QGROUP_RSV_LAST,
173};
174
175/*
176 * Represents how many bytes we have reserved for this qgroup.
177 *
178 * Each type should have different reservation behavior.
179 * E.g, data follows its io_tree flag modification, while
52042d8e 180 * *currently* meta is just reserve-and-clear during transaction.
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181 *
182 * TODO: Add new type for reservation which can survive transaction commit.
52042d8e 183 * Current metadata reservation behavior is not suitable for such case.
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184 */
185struct btrfs_qgroup_rsv {
186 u64 values[BTRFS_QGROUP_RSV_LAST];
187};
188
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189/*
190 * one struct for each qgroup, organized in fs_info->qgroup_tree.
191 */
192struct btrfs_qgroup {
193 u64 qgroupid;
194
195 /*
196 * state
197 */
198 u64 rfer; /* referenced */
199 u64 rfer_cmpr; /* referenced compressed */
200 u64 excl; /* exclusive */
201 u64 excl_cmpr; /* exclusive compressed */
202
203 /*
204 * limits
205 */
206 u64 lim_flags; /* which limits are set */
207 u64 max_rfer;
208 u64 max_excl;
209 u64 rsv_rfer;
210 u64 rsv_excl;
211
212 /*
213 * reservation tracking
214 */
d4e5c920 215 struct btrfs_qgroup_rsv rsv;
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216
217 /*
218 * lists
219 */
220 struct list_head groups; /* groups this group is member of */
221 struct list_head members; /* groups that are members of this group */
222 struct list_head dirty; /* dirty groups */
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223
224 /*
225 * For qgroup iteration usage.
226 *
227 * The iteration list should always be empty until qgroup_iterator_add()
228 * is called. And should be reset to empty after the iteration is
229 * finished.
230 */
231 struct list_head iterator;
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232
233 /*
234 * For nested iterator usage.
235 *
236 * Here we support at most one level of nested iterator calls like:
237 *
238 * LIST_HEAD(all_qgroups);
239 * {
240 * LIST_HEAD(local_qgroups);
241 * qgroup_iterator_add(local_qgroups, qg);
242 * qgroup_iterator_nested_add(all_qgroups, qg);
243 * do_some_work(local_qgroups);
244 * qgroup_iterator_clean(local_qgroups);
245 * }
246 * do_some_work(all_qgroups);
247 * qgroup_iterator_nested_clean(all_qgroups);
248 */
249 struct list_head nested_iterator;
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250 struct rb_node node; /* tree of qgroups */
251
252 /*
253 * temp variables for accounting operations
254 * Refer to qgroup_shared_accounting() for details.
255 */
256 u64 old_refcnt;
257 u64 new_refcnt;
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258
259 /*
260 * Sysfs kobjectid
261 */
262 struct kobject kobj;
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263};
264
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265static inline u64 btrfs_qgroup_subvolid(u64 qgroupid)
266{
267 return (qgroupid & ((1ULL << BTRFS_QGROUP_LEVEL_SHIFT) - 1));
268}
269
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270/*
271 * For qgroup event trace points only
272 */
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273enum {
274 ENUM_BIT(QGROUP_RESERVE),
275 ENUM_BIT(QGROUP_RELEASE),
276 ENUM_BIT(QGROUP_FREE),
277};
81fb6f77 278
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279int btrfs_quota_enable(struct btrfs_fs_info *fs_info);
280int btrfs_quota_disable(struct btrfs_fs_info *fs_info);
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281int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
282void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
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283int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
284 bool interruptible);
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285int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
286 u64 dst);
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287int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
288 u64 dst);
49a05ecd 289int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
3efbee1d 290int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
f0042d5e 291int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
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292 struct btrfs_qgroup_limit *limit);
293int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
294void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
295struct btrfs_delayed_extent_op;
d1b8b94a 296
50b3e040 297int btrfs_qgroup_trace_extent_nolock(
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298 struct btrfs_fs_info *fs_info,
299 struct btrfs_delayed_ref_root *delayed_refs,
300 struct btrfs_qgroup_extent_record *record);
8949b9a1 301int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
fb235dc0 302 struct btrfs_qgroup_extent_record *qrecord);
a95f3aaf 303int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
e2896e79 304 u64 num_bytes);
33d1f05c 305int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
33d1f05c 306 struct extent_buffer *eb);
33d1f05c 307int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
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308 struct extent_buffer *root_eb,
309 u64 root_gen, int root_level);
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310int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
311 u64 num_bytes, struct ulist *old_roots,
312 struct ulist *new_roots);
460fb20a 313int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans);
280f8bd2 314int btrfs_run_qgroups(struct btrfs_trans_handle *trans);
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315int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
316 u64 objectid, struct btrfs_qgroup_inherit *inherit);
297d750b 317void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
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318 u64 ref_root, u64 num_bytes,
319 enum btrfs_qgroup_rsv_type type);
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320
321#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
322int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
323 u64 rfer, u64 excl);
324#endif
325
52472553 326/* New io_tree based accurate qgroup reserve API */
7661a3e0 327int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
364ecf36 328 struct extent_changeset **reserved, u64 start, u64 len);
72b7d15b 329int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len);
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330int btrfs_qgroup_free_data(struct btrfs_inode *inode,
331 struct extent_changeset *reserved, u64 start,
332 u64 len);
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333int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
334 enum btrfs_qgroup_rsv_type type, bool enforce);
733e03a0 335int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
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336 enum btrfs_qgroup_rsv_type type, bool enforce,
337 bool noflush);
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338/* Reserve metadata space for pertrans and prealloc type */
339static inline int btrfs_qgroup_reserve_meta_pertrans(struct btrfs_root *root,
340 int num_bytes, bool enforce)
341{
342 return __btrfs_qgroup_reserve_meta(root, num_bytes,
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343 BTRFS_QGROUP_RSV_META_PERTRANS,
344 enforce, false);
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345}
346static inline int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root,
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347 int num_bytes, bool enforce,
348 bool noflush)
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349{
350 return __btrfs_qgroup_reserve_meta(root, num_bytes,
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351 BTRFS_QGROUP_RSV_META_PREALLOC,
352 enforce, noflush);
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353}
354
355void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
356 enum btrfs_qgroup_rsv_type type);
357
358/* Free per-transaction meta reservation for error handling */
359static inline void btrfs_qgroup_free_meta_pertrans(struct btrfs_root *root,
360 int num_bytes)
361{
362 __btrfs_qgroup_free_meta(root, num_bytes,
363 BTRFS_QGROUP_RSV_META_PERTRANS);
364}
365
366/* Pre-allocated meta reservation can be freed at need */
367static inline void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root,
368 int num_bytes)
369{
370 __btrfs_qgroup_free_meta(root, num_bytes,
371 BTRFS_QGROUP_RSV_META_PREALLOC);
372}
373
733e03a0 374void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root);
64cfaef6 375void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes);
cfdd4592 376void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode);
9888c340 377
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378/* btrfs_qgroup_swapped_blocks related functions */
379void btrfs_qgroup_init_swapped_blocks(
380 struct btrfs_qgroup_swapped_blocks *swapped_blocks);
381
382void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root);
383int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
384 struct btrfs_root *subvol_root,
32da5386 385 struct btrfs_block_group *bg,
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386 struct extent_buffer *subvol_parent, int subvol_slot,
387 struct extent_buffer *reloc_parent, int reloc_slot,
388 u64 last_snapshot);
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389int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
390 struct btrfs_root *root, struct extent_buffer *eb);
81f7eb00 391void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans);
5958253c 392bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info);
370a11b8 393
9888c340 394#endif