xref: /openbmc/linux/fs/btrfs/qgroup.h (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
1 /*
2  * Copyright (C) 2014 Facebook.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #ifndef __BTRFS_QGROUP__
20 #define __BTRFS_QGROUP__
21 
22 #include "ulist.h"
23 #include "delayed-ref.h"
24 
25 /*
26  * Btrfs qgroup overview
27  *
28  * Btrfs qgroup splits into 3 main part:
29  * 1) Reserve
30  *    Reserve metadata/data space for incoming operations
31  *    Affect how qgroup limit works
32  *
33  * 2) Trace
34  *    Tell btrfs qgroup to trace dirty extents.
35  *
36  *    Dirty extents including:
37  *    - Newly allocated extents
38  *    - Extents going to be deleted (in this trans)
39  *    - Extents whose owner is going to be modified
40  *
41  *    This is the main part affects whether qgroup numbers will stay
42  *    consistent.
43  *    Btrfs qgroup can trace clean extents and won't cause any problem,
44  *    but it will consume extra CPU time, it should be avoided if possible.
45  *
46  * 3) Account
47  *    Btrfs qgroup will updates its numbers, based on dirty extents traced
48  *    in previous step.
49  *
50  *    Normally at qgroup rescan and transaction commit time.
51  */
52 
53 /*
54  * Record a dirty extent, and info qgroup to update quota on it
55  * TODO: Use kmem cache to alloc it.
56  */
57 struct btrfs_qgroup_extent_record {
58 	struct rb_node node;
59 	u64 bytenr;
60 	u64 num_bytes;
61 	struct ulist *old_roots;
62 };
63 
64 /*
65  * Qgroup reservation types:
66  *
67  * DATA:
68  *	space reserved for data
69  *
70  * META_PERTRANS:
71  * 	Space reserved for metadata (per-transaction)
72  * 	Due to the fact that qgroup data is only updated at transaction commit
73  * 	time, reserved space for metadata must be kept until transaction
74  * 	commits.
75  * 	Any metadata reserved that are used in btrfs_start_transaction() should
76  * 	be of this type.
77  *
78  * META_PREALLOC:
79  *	There are cases where metadata space is reserved before starting
80  *	transaction, and then btrfs_join_transaction() to get a trans handle.
81  *	Any metadata reserved for such usage should be of this type.
82  *	And after join_transaction() part (or all) of such reservation should
83  *	be converted into META_PERTRANS.
84  */
85 enum btrfs_qgroup_rsv_type {
86 	BTRFS_QGROUP_RSV_DATA = 0,
87 	BTRFS_QGROUP_RSV_META_PERTRANS,
88 	BTRFS_QGROUP_RSV_META_PREALLOC,
89 	BTRFS_QGROUP_RSV_LAST,
90 };
91 
92 /*
93  * Represents how many bytes we have reserved for this qgroup.
94  *
95  * Each type should have different reservation behavior.
96  * E.g, data follows its io_tree flag modification, while
97  * *currently* meta is just reserve-and-clear during transcation.
98  *
99  * TODO: Add new type for reservation which can survive transaction commit.
100  * Currect metadata reservation behavior is not suitable for such case.
101  */
102 struct btrfs_qgroup_rsv {
103 	u64 values[BTRFS_QGROUP_RSV_LAST];
104 };
105 
106 /*
107  * one struct for each qgroup, organized in fs_info->qgroup_tree.
108  */
109 struct btrfs_qgroup {
110 	u64 qgroupid;
111 
112 	/*
113 	 * state
114 	 */
115 	u64 rfer;	/* referenced */
116 	u64 rfer_cmpr;	/* referenced compressed */
117 	u64 excl;	/* exclusive */
118 	u64 excl_cmpr;	/* exclusive compressed */
119 
120 	/*
121 	 * limits
122 	 */
123 	u64 lim_flags;	/* which limits are set */
124 	u64 max_rfer;
125 	u64 max_excl;
126 	u64 rsv_rfer;
127 	u64 rsv_excl;
128 
129 	/*
130 	 * reservation tracking
131 	 */
132 	struct btrfs_qgroup_rsv rsv;
133 
134 	/*
135 	 * lists
136 	 */
137 	struct list_head groups;  /* groups this group is member of */
138 	struct list_head members; /* groups that are members of this group */
139 	struct list_head dirty;   /* dirty groups */
140 	struct rb_node node;	  /* tree of qgroups */
141 
142 	/*
143 	 * temp variables for accounting operations
144 	 * Refer to qgroup_shared_accounting() for details.
145 	 */
146 	u64 old_refcnt;
147 	u64 new_refcnt;
148 };
149 
150 /*
151  * For qgroup event trace points only
152  */
153 #define QGROUP_RESERVE		(1<<0)
154 #define QGROUP_RELEASE		(1<<1)
155 #define QGROUP_FREE		(1<<2)
156 
157 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
158 		       struct btrfs_fs_info *fs_info);
159 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
160 			struct btrfs_fs_info *fs_info);
161 int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
162 void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
163 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
164 				     bool interruptible);
165 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
166 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
167 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
168 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
169 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
170 			struct btrfs_fs_info *fs_info, u64 qgroupid);
171 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
172 			      struct btrfs_fs_info *fs_info, u64 qgroupid);
173 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
174 		       struct btrfs_fs_info *fs_info, u64 qgroupid,
175 		       struct btrfs_qgroup_limit *limit);
176 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
177 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
178 struct btrfs_delayed_extent_op;
179 
180 /*
181  * Inform qgroup to trace one dirty extent, its info is recorded in @record.
182  * So qgroup can account it at transaction committing time.
183  *
184  * No lock version, caller must acquire delayed ref lock and allocated memory,
185  * then call btrfs_qgroup_trace_extent_post() after exiting lock context.
186  *
187  * Return 0 for success insert
188  * Return >0 for existing record, caller can free @record safely.
189  * Error is not possible
190  */
191 int btrfs_qgroup_trace_extent_nolock(
192 		struct btrfs_fs_info *fs_info,
193 		struct btrfs_delayed_ref_root *delayed_refs,
194 		struct btrfs_qgroup_extent_record *record);
195 
196 /*
197  * Post handler after qgroup_trace_extent_nolock().
198  *
199  * NOTE: Current qgroup does the expensive backref walk at transaction
200  * committing time with TRANS_STATE_COMMIT_DOING, this blocks incoming
201  * new transaction.
202  * This is designed to allow btrfs_find_all_roots() to get correct new_roots
203  * result.
204  *
205  * However for old_roots there is no need to do backref walk at that time,
206  * since we search commit roots to walk backref and result will always be
207  * correct.
208  *
209  * Due to the nature of no lock version, we can't do backref there.
210  * So we must call btrfs_qgroup_trace_extent_post() after exiting
211  * spinlock context.
212  *
213  * TODO: If we can fix and prove btrfs_find_all_roots() can get correct result
214  * using current root, then we can move all expensive backref walk out of
215  * transaction committing, but not now as qgroup accounting will be wrong again.
216  */
217 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
218 				   struct btrfs_qgroup_extent_record *qrecord);
219 
220 /*
221  * Inform qgroup to trace one dirty extent, specified by @bytenr and
222  * @num_bytes.
223  * So qgroup can account it at commit trans time.
224  *
225  * Better encapsulated version, with memory allocation and backref walk for
226  * commit roots.
227  * So this can sleep.
228  *
229  * Return 0 if the operation is done.
230  * Return <0 for error, like memory allocation failure or invalid parameter
231  * (NULL trans)
232  */
233 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
234 		struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes,
235 		gfp_t gfp_flag);
236 
237 /*
238  * Inform qgroup to trace all leaf items of data
239  *
240  * Return 0 for success
241  * Return <0 for error(ENOMEM)
242  */
243 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
244 				  struct btrfs_fs_info *fs_info,
245 				  struct extent_buffer *eb);
246 /*
247  * Inform qgroup to trace a whole subtree, including all its child tree
248  * blocks and data.
249  * The root tree block is specified by @root_eb.
250  *
251  * Normally used by relocation(tree block swap) and subvolume deletion.
252  *
253  * Return 0 for success
254  * Return <0 for error(ENOMEM or tree search error)
255  */
256 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
257 			       struct btrfs_root *root,
258 			       struct extent_buffer *root_eb,
259 			       u64 root_gen, int root_level);
260 int
261 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
262 			    struct btrfs_fs_info *fs_info,
263 			    u64 bytenr, u64 num_bytes,
264 			    struct ulist *old_roots, struct ulist *new_roots);
265 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans);
266 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
267 		      struct btrfs_fs_info *fs_info);
268 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
269 			 struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
270 			 struct btrfs_qgroup_inherit *inherit);
271 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
272 			       u64 ref_root, u64 num_bytes,
273 			       enum btrfs_qgroup_rsv_type type);
274 static inline void btrfs_qgroup_free_delayed_ref(struct btrfs_fs_info *fs_info,
275 						 u64 ref_root, u64 num_bytes)
276 {
277 	trace_btrfs_qgroup_free_delayed_ref(fs_info, ref_root, num_bytes);
278 	btrfs_qgroup_free_refroot(fs_info, ref_root, num_bytes,
279 				  BTRFS_QGROUP_RSV_DATA);
280 }
281 
282 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
283 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
284 			       u64 rfer, u64 excl);
285 #endif
286 
287 /* New io_tree based accurate qgroup reserve API */
288 int btrfs_qgroup_reserve_data(struct inode *inode,
289 			struct extent_changeset **reserved, u64 start, u64 len);
290 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len);
291 int btrfs_qgroup_free_data(struct inode *inode,
292 			struct extent_changeset *reserved, u64 start, u64 len);
293 
294 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
295 				enum btrfs_qgroup_rsv_type type, bool enforce);
296 /* Reserve metadata space for pertrans and prealloc type */
297 static inline int btrfs_qgroup_reserve_meta_pertrans(struct btrfs_root *root,
298 				int num_bytes, bool enforce)
299 {
300 	return __btrfs_qgroup_reserve_meta(root, num_bytes,
301 			BTRFS_QGROUP_RSV_META_PERTRANS, enforce);
302 }
303 static inline int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root,
304 				int num_bytes, bool enforce)
305 {
306 	return __btrfs_qgroup_reserve_meta(root, num_bytes,
307 			BTRFS_QGROUP_RSV_META_PREALLOC, enforce);
308 }
309 
310 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
311 			     enum btrfs_qgroup_rsv_type type);
312 
313 /* Free per-transaction meta reservation for error handling */
314 static inline void btrfs_qgroup_free_meta_pertrans(struct btrfs_root *root,
315 						   int num_bytes)
316 {
317 	__btrfs_qgroup_free_meta(root, num_bytes,
318 			BTRFS_QGROUP_RSV_META_PERTRANS);
319 }
320 
321 /* Pre-allocated meta reservation can be freed at need */
322 static inline void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root,
323 						   int num_bytes)
324 {
325 	__btrfs_qgroup_free_meta(root, num_bytes,
326 			BTRFS_QGROUP_RSV_META_PREALLOC);
327 }
328 
329 /*
330  * Per-transaction meta reservation should be all freed at transaction commit
331  * time
332  */
333 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root);
334 
335 /*
336  * Convert @num_bytes of META_PREALLOCATED reservation to META_PERTRANS.
337  *
338  * This is called when preallocated meta reservation needs to be used.
339  * Normally after btrfs_join_transaction() call.
340  */
341 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes);
342 
343 void btrfs_qgroup_check_reserved_leak(struct inode *inode);
344 #endif /* __BTRFS_QGROUP__ */
345