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