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
 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					   BTRFS_QGROUP_RSV_META_PERTRANS,
406					   enforce, 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					   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			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			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