xref: /linux/fs/bcachefs/snapshot.h (revision af8e51644a70f612974a6e767fa7d896d3c23f88) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _BCACHEFS_SNAPSHOT_H
3 #define _BCACHEFS_SNAPSHOT_H
4 
5 enum bch_validate_flags;
6 
7 void bch2_snapshot_tree_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
8 int bch2_snapshot_tree_invalid(struct bch_fs *, struct bkey_s_c,
9 			       enum bch_validate_flags, struct printbuf *);
10 
11 #define bch2_bkey_ops_snapshot_tree ((struct bkey_ops) {	\
12 	.key_invalid	= bch2_snapshot_tree_invalid,		\
13 	.val_to_text	= bch2_snapshot_tree_to_text,		\
14 	.min_val_size	= 8,					\
15 })
16 
17 struct bkey_i_snapshot_tree *__bch2_snapshot_tree_create(struct btree_trans *);
18 
19 int bch2_snapshot_tree_lookup(struct btree_trans *, u32, struct bch_snapshot_tree *);
20 
21 void bch2_snapshot_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
22 int bch2_snapshot_invalid(struct bch_fs *, struct bkey_s_c,
23 			  enum bch_validate_flags, struct printbuf *);
24 int bch2_mark_snapshot(struct btree_trans *, enum btree_id, unsigned,
25 		       struct bkey_s_c, struct bkey_s,
26 		       enum btree_iter_update_trigger_flags);
27 
28 #define bch2_bkey_ops_snapshot ((struct bkey_ops) {		\
29 	.key_invalid	= bch2_snapshot_invalid,		\
30 	.val_to_text	= bch2_snapshot_to_text,		\
31 	.trigger	= bch2_mark_snapshot,			\
32 	.min_val_size	= 24,					\
33 })
34 
35 static inline struct snapshot_t *__snapshot_t(struct snapshot_table *t, u32 id)
36 {
37 	u32 idx = U32_MAX - id;
38 
39 	return likely(t && idx < t->nr)
40 		? &t->s[idx]
41 		: NULL;
42 }
43 
44 static inline const struct snapshot_t *snapshot_t(struct bch_fs *c, u32 id)
45 {
46 	return __snapshot_t(rcu_dereference(c->snapshots), id);
47 }
48 
49 static inline u32 bch2_snapshot_tree(struct bch_fs *c, u32 id)
50 {
51 	rcu_read_lock();
52 	const struct snapshot_t *s = snapshot_t(c, id);
53 	id = s ? s->tree : 0;
54 	rcu_read_unlock();
55 
56 	return id;
57 }
58 
59 static inline u32 __bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
60 {
61 	const struct snapshot_t *s = snapshot_t(c, id);
62 	return s ? s->parent : 0;
63 }
64 
65 static inline u32 bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
66 {
67 	rcu_read_lock();
68 	id = __bch2_snapshot_parent_early(c, id);
69 	rcu_read_unlock();
70 
71 	return id;
72 }
73 
74 static inline u32 __bch2_snapshot_parent(struct bch_fs *c, u32 id)
75 {
76 	const struct snapshot_t *s = snapshot_t(c, id);
77 	if (!s)
78 		return 0;
79 
80 	u32 parent = s->parent;
81 	if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
82 	    parent &&
83 	    s->depth != snapshot_t(c, parent)->depth + 1)
84 		panic("id %u depth=%u parent %u depth=%u\n",
85 		      id, snapshot_t(c, id)->depth,
86 		      parent, snapshot_t(c, parent)->depth);
87 
88 	return parent;
89 }
90 
91 static inline u32 bch2_snapshot_parent(struct bch_fs *c, u32 id)
92 {
93 	rcu_read_lock();
94 	id = __bch2_snapshot_parent(c, id);
95 	rcu_read_unlock();
96 
97 	return id;
98 }
99 
100 static inline u32 bch2_snapshot_nth_parent(struct bch_fs *c, u32 id, u32 n)
101 {
102 	rcu_read_lock();
103 	while (n--)
104 		id = __bch2_snapshot_parent(c, id);
105 	rcu_read_unlock();
106 
107 	return id;
108 }
109 
110 u32 bch2_snapshot_skiplist_get(struct bch_fs *, u32);
111 
112 static inline u32 bch2_snapshot_root(struct bch_fs *c, u32 id)
113 {
114 	u32 parent;
115 
116 	rcu_read_lock();
117 	while ((parent = __bch2_snapshot_parent(c, id)))
118 		id = parent;
119 	rcu_read_unlock();
120 
121 	return id;
122 }
123 
124 static inline u32 __bch2_snapshot_equiv(struct bch_fs *c, u32 id)
125 {
126 	const struct snapshot_t *s = snapshot_t(c, id);
127 	return s ? s->equiv : 0;
128 }
129 
130 static inline u32 bch2_snapshot_equiv(struct bch_fs *c, u32 id)
131 {
132 	rcu_read_lock();
133 	id = __bch2_snapshot_equiv(c, id);
134 	rcu_read_unlock();
135 
136 	return id;
137 }
138 
139 static inline int bch2_snapshot_is_internal_node(struct bch_fs *c, u32 id)
140 {
141 	rcu_read_lock();
142 	const struct snapshot_t *s = snapshot_t(c, id);
143 	int ret = s ? s->children[0] : -BCH_ERR_invalid_snapshot_node;
144 	rcu_read_unlock();
145 
146 	return ret;
147 }
148 
149 static inline int bch2_snapshot_is_leaf(struct bch_fs *c, u32 id)
150 {
151 	int ret = bch2_snapshot_is_internal_node(c, id);
152 	if (ret < 0)
153 		return ret;
154 	return !ret;
155 }
156 
157 static inline u32 bch2_snapshot_depth(struct bch_fs *c, u32 parent)
158 {
159 	u32 depth;
160 
161 	rcu_read_lock();
162 	depth = parent ? snapshot_t(c, parent)->depth + 1 : 0;
163 	rcu_read_unlock();
164 
165 	return depth;
166 }
167 
168 bool __bch2_snapshot_is_ancestor(struct bch_fs *, u32, u32);
169 
170 static inline bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor)
171 {
172 	return id == ancestor
173 		? true
174 		: __bch2_snapshot_is_ancestor(c, id, ancestor);
175 }
176 
177 static inline bool bch2_snapshot_has_children(struct bch_fs *c, u32 id)
178 {
179 	rcu_read_lock();
180 	const struct snapshot_t *t = snapshot_t(c, id);
181 	bool ret = t && (t->children[0]|t->children[1]) != 0;
182 	rcu_read_unlock();
183 
184 	return ret;
185 }
186 
187 static inline bool snapshot_list_has_id(snapshot_id_list *s, u32 id)
188 {
189 	darray_for_each(*s, i)
190 		if (*i == id)
191 			return true;
192 	return false;
193 }
194 
195 static inline bool snapshot_list_has_ancestor(struct bch_fs *c, snapshot_id_list *s, u32 id)
196 {
197 	darray_for_each(*s, i)
198 		if (bch2_snapshot_is_ancestor(c, id, *i))
199 			return true;
200 	return false;
201 }
202 
203 static inline int snapshot_list_add(struct bch_fs *c, snapshot_id_list *s, u32 id)
204 {
205 	BUG_ON(snapshot_list_has_id(s, id));
206 	int ret = darray_push(s, id);
207 	if (ret)
208 		bch_err(c, "error reallocating snapshot_id_list (size %zu)", s->size);
209 	return ret;
210 }
211 
212 static inline int snapshot_list_add_nodup(struct bch_fs *c, snapshot_id_list *s, u32 id)
213 {
214 	int ret = snapshot_list_has_id(s, id)
215 		? 0
216 		: darray_push(s, id);
217 	if (ret)
218 		bch_err(c, "error reallocating snapshot_id_list (size %zu)", s->size);
219 	return ret;
220 }
221 
222 static inline int snapshot_list_merge(struct bch_fs *c, snapshot_id_list *dst, snapshot_id_list *src)
223 {
224 	darray_for_each(*src, i) {
225 		int ret = snapshot_list_add_nodup(c, dst, *i);
226 		if (ret)
227 			return ret;
228 	}
229 
230 	return 0;
231 }
232 
233 int bch2_snapshot_lookup(struct btree_trans *trans, u32 id,
234 			 struct bch_snapshot *s);
235 int bch2_snapshot_get_subvol(struct btree_trans *, u32,
236 			     struct bch_subvolume *);
237 
238 /* only exported for tests: */
239 int bch2_snapshot_node_create(struct btree_trans *, u32,
240 			      u32 *, u32 *, unsigned);
241 
242 int bch2_check_snapshot_trees(struct bch_fs *);
243 int bch2_check_snapshots(struct bch_fs *);
244 int bch2_reconstruct_snapshots(struct bch_fs *);
245 int bch2_check_key_has_snapshot(struct btree_trans *, struct btree_iter *, struct bkey_s_c);
246 
247 int bch2_snapshot_node_set_deleted(struct btree_trans *, u32);
248 void bch2_delete_dead_snapshots_work(struct work_struct *);
249 
250 int __bch2_key_has_snapshot_overwrites(struct btree_trans *, enum btree_id, struct bpos);
251 
252 static inline int bch2_key_has_snapshot_overwrites(struct btree_trans *trans,
253 					  enum btree_id id,
254 					  struct bpos pos)
255 {
256 	if (!btree_type_has_snapshots(id) ||
257 	    bch2_snapshot_is_leaf(trans->c, pos.snapshot) > 0)
258 		return 0;
259 
260 	return __bch2_key_has_snapshot_overwrites(trans, id, pos);
261 }
262 
263 int bch2_propagate_key_to_snapshot_leaves(struct btree_trans *, enum btree_id,
264 					  struct bkey_s_c, struct bpos *);
265 
266 int bch2_snapshots_read(struct bch_fs *);
267 void bch2_fs_snapshots_exit(struct bch_fs *);
268 
269 #endif /* _BCACHEFS_SNAPSHOT_H */
270