Line data Source code
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 : #include "misc.h"
15 :
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 :
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 :
104 : #define BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN (1UL << 3)
105 : #define BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING (1UL << 4)
106 :
107 : /*
108 : * Record a dirty extent, and info qgroup to update quota on it
109 : * TODO: Use kmem cache to alloc it.
110 : */
111 : struct btrfs_qgroup_extent_record {
112 : struct rb_node node;
113 : u64 bytenr;
114 : u64 num_bytes;
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 */
126 : struct ulist *old_roots;
127 : };
128 :
129 : struct 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 :
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 : */
168 : enum btrfs_qgroup_rsv_type {
169 : BTRFS_QGROUP_RSV_DATA,
170 : BTRFS_QGROUP_RSV_META_PERTRANS,
171 : BTRFS_QGROUP_RSV_META_PREALLOC,
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
180 : * *currently* meta is just reserve-and-clear during transaction.
181 : *
182 : * TODO: Add new type for reservation which can survive transaction commit.
183 : * Current metadata reservation behavior is not suitable for such case.
184 : */
185 : struct btrfs_qgroup_rsv {
186 : u64 values[BTRFS_QGROUP_RSV_LAST];
187 : };
188 :
189 : /*
190 : * one struct for each qgroup, organized in fs_info->qgroup_tree.
191 : */
192 : struct 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 : */
215 : struct btrfs_qgroup_rsv rsv;
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 */
223 : struct rb_node node; /* tree of qgroups */
224 :
225 : /*
226 : * temp variables for accounting operations
227 : * Refer to qgroup_shared_accounting() for details.
228 : */
229 : u64 old_refcnt;
230 : u64 new_refcnt;
231 :
232 : /*
233 : * Sysfs kobjectid
234 : */
235 : struct kobject kobj;
236 : };
237 :
238 : static inline u64 btrfs_qgroup_subvolid(u64 qgroupid)
239 : {
240 0 : return (qgroupid & ((1ULL << BTRFS_QGROUP_LEVEL_SHIFT) - 1));
241 : }
242 :
243 : /*
244 : * For qgroup event trace points only
245 : */
246 : enum {
247 : ENUM_BIT(QGROUP_RESERVE),
248 : ENUM_BIT(QGROUP_RELEASE),
249 : ENUM_BIT(QGROUP_FREE),
250 : };
251 :
252 : int btrfs_quota_enable(struct btrfs_fs_info *fs_info);
253 : int btrfs_quota_disable(struct btrfs_fs_info *fs_info);
254 : int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
255 : void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
256 : int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
257 : bool interruptible);
258 : int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
259 : u64 dst);
260 : int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
261 : u64 dst);
262 : int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
263 : int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
264 : int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
265 : struct btrfs_qgroup_limit *limit);
266 : int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
267 : void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
268 : struct btrfs_delayed_extent_op;
269 :
270 : /*
271 : * Inform qgroup to trace one dirty extent, its info is recorded in @record.
272 : * So qgroup can account it at transaction committing time.
273 : *
274 : * No lock version, caller must acquire delayed ref lock and allocated memory,
275 : * then call btrfs_qgroup_trace_extent_post() after exiting lock context.
276 : *
277 : * Return 0 for success insert
278 : * Return >0 for existing record, caller can free @record safely.
279 : * Error is not possible
280 : */
281 : int btrfs_qgroup_trace_extent_nolock(
282 : struct btrfs_fs_info *fs_info,
283 : struct btrfs_delayed_ref_root *delayed_refs,
284 : struct btrfs_qgroup_extent_record *record);
285 :
286 : /*
287 : * Post handler after qgroup_trace_extent_nolock().
288 : *
289 : * NOTE: Current qgroup does the expensive backref walk at transaction
290 : * committing time with TRANS_STATE_COMMIT_DOING, this blocks incoming
291 : * new transaction.
292 : * This is designed to allow btrfs_find_all_roots() to get correct new_roots
293 : * result.
294 : *
295 : * However for old_roots there is no need to do backref walk at that time,
296 : * since we search commit roots to walk backref and result will always be
297 : * correct.
298 : *
299 : * Due to the nature of no lock version, we can't do backref there.
300 : * So we must call btrfs_qgroup_trace_extent_post() after exiting
301 : * spinlock context.
302 : *
303 : * TODO: If we can fix and prove btrfs_find_all_roots() can get correct result
304 : * using current root, then we can move all expensive backref walk out of
305 : * transaction committing, but not now as qgroup accounting will be wrong again.
306 : */
307 : int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
308 : struct btrfs_qgroup_extent_record *qrecord);
309 :
310 : /*
311 : * Inform qgroup to trace one dirty extent, specified by @bytenr and
312 : * @num_bytes.
313 : * So qgroup can account it at commit trans time.
314 : *
315 : * Better encapsulated version, with memory allocation and backref walk for
316 : * commit roots.
317 : * So this can sleep.
318 : *
319 : * Return 0 if the operation is done.
320 : * Return <0 for error, like memory allocation failure or invalid parameter
321 : * (NULL trans)
322 : */
323 : int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
324 : u64 num_bytes);
325 :
326 : /*
327 : * Inform qgroup to trace all leaf items of data
328 : *
329 : * Return 0 for success
330 : * Return <0 for error(ENOMEM)
331 : */
332 : int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
333 : struct extent_buffer *eb);
334 : /*
335 : * Inform qgroup to trace a whole subtree, including all its child tree
336 : * blocks and data.
337 : * The root tree block is specified by @root_eb.
338 : *
339 : * Normally used by relocation(tree block swap) and subvolume deletion.
340 : *
341 : * Return 0 for success
342 : * Return <0 for error(ENOMEM or tree search error)
343 : */
344 : int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
345 : struct extent_buffer *root_eb,
346 : u64 root_gen, int root_level);
347 : int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
348 : u64 num_bytes, struct ulist *old_roots,
349 : struct ulist *new_roots);
350 : int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans);
351 : int btrfs_run_qgroups(struct btrfs_trans_handle *trans);
352 : int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
353 : u64 objectid, struct btrfs_qgroup_inherit *inherit);
354 : void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
355 : u64 ref_root, u64 num_bytes,
356 : enum btrfs_qgroup_rsv_type type);
357 :
358 : #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
359 : int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
360 : u64 rfer, u64 excl);
361 : #endif
362 :
363 : /* New io_tree based accurate qgroup reserve API */
364 : int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
365 : struct extent_changeset **reserved, u64 start, u64 len);
366 : int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len);
367 : int btrfs_qgroup_free_data(struct btrfs_inode *inode,
368 : struct extent_changeset *reserved, u64 start,
369 : u64 len);
370 : int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
371 : enum btrfs_qgroup_rsv_type type, bool enforce);
372 : int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
373 : enum btrfs_qgroup_rsv_type type, bool enforce,
374 : bool noflush);
375 : /* Reserve metadata space for pertrans and prealloc type */
376 : static inline int btrfs_qgroup_reserve_meta_pertrans(struct btrfs_root *root,
377 : int num_bytes, bool enforce)
378 : {
379 0 : return __btrfs_qgroup_reserve_meta(root, num_bytes,
380 : BTRFS_QGROUP_RSV_META_PERTRANS,
381 : enforce, false);
382 : }
383 : static inline int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root,
384 : int num_bytes, bool enforce,
385 : bool noflush)
386 : {
387 0 : return __btrfs_qgroup_reserve_meta(root, num_bytes,
388 : BTRFS_QGROUP_RSV_META_PREALLOC,
389 : enforce, noflush);
390 : }
391 :
392 : void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
393 : enum btrfs_qgroup_rsv_type type);
394 :
395 : /* Free per-transaction meta reservation for error handling */
396 : static inline void btrfs_qgroup_free_meta_pertrans(struct btrfs_root *root,
397 : int num_bytes)
398 : {
399 0 : __btrfs_qgroup_free_meta(root, num_bytes,
400 : BTRFS_QGROUP_RSV_META_PERTRANS);
401 : }
402 :
403 : /* Pre-allocated meta reservation can be freed at need */
404 : static inline void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root,
405 : int num_bytes)
406 : {
407 0 : __btrfs_qgroup_free_meta(root, num_bytes,
408 : BTRFS_QGROUP_RSV_META_PREALLOC);
409 0 : }
410 :
411 : /*
412 : * Per-transaction meta reservation should be all freed at transaction commit
413 : * time
414 : */
415 : void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root);
416 :
417 : /*
418 : * Convert @num_bytes of META_PREALLOCATED reservation to META_PERTRANS.
419 : *
420 : * This is called when preallocated meta reservation needs to be used.
421 : * Normally after btrfs_join_transaction() call.
422 : */
423 : void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes);
424 :
425 : void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode);
426 :
427 : /* btrfs_qgroup_swapped_blocks related functions */
428 : void btrfs_qgroup_init_swapped_blocks(
429 : struct btrfs_qgroup_swapped_blocks *swapped_blocks);
430 :
431 : void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root);
432 : int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
433 : struct btrfs_root *subvol_root,
434 : struct btrfs_block_group *bg,
435 : struct extent_buffer *subvol_parent, int subvol_slot,
436 : struct extent_buffer *reloc_parent, int reloc_slot,
437 : u64 last_snapshot);
438 : int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
439 : struct btrfs_root *root, struct extent_buffer *eb);
440 : void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans);
441 : bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info);
442 :
443 : #endif
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