fs/bcachefs/snapshot.h

   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_validate(struct bch_fs *, struct bkey_s_c,
   9                                enum bch_validate_flags);
  10
  11 #define bch2_bkey_ops_snapshot_tree ((struct bkey_ops) {        \
  12         .key_validate   = bch2_snapshot_tree_validate,          \
  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_validate(struct bch_fs *, struct bkey_s_c, enum bch_validate_flags);
  23 int bch2_mark_snapshot(struct btree_trans *, enum btree_id, unsigned,
  24                        struct bkey_s_c, struct bkey_s,
  25                        enum btree_iter_update_trigger_flags);
  26
  27 #define bch2_bkey_ops_snapshot ((struct bkey_ops) {             \
  28         .key_validate   = bch2_snapshot_validate,               \
  29         .val_to_text    = bch2_snapshot_to_text,                \
  30         .trigger        = bch2_mark_snapshot,                   \
  31         .min_val_size   = 24,                                   \
  32 })
  33
  34 static inline struct snapshot_t *__snapshot_t(struct snapshot_table *t, u32 id)
  35 {
  36         u32 idx = U32_MAX - id;
  37
  38         return likely(t && idx < t->nr)
  39                 ? &t->s[idx]
  40                 : NULL;
  41 }
  42
  43 static inline const struct snapshot_t *snapshot_t(struct bch_fs *c, u32 id)
  44 {
  45         return __snapshot_t(rcu_dereference(c->snapshots), id);
  46 }
  47
  48 static inline u32 bch2_snapshot_tree(struct bch_fs *c, u32 id)
  49 {
  50         rcu_read_lock();
  51         const struct snapshot_t *s = snapshot_t(c, id);
  52         id = s ? s->tree : 0;
  53         rcu_read_unlock();
  54
  55         return id;
  56 }
  57
  58 static inline u32 __bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
  59 {
  60         const struct snapshot_t *s = snapshot_t(c, id);
  61         return s ? s->parent : 0;
  62 }
  63
  64 static inline u32 bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
  65 {
  66         rcu_read_lock();
  67         id = __bch2_snapshot_parent_early(c, id);
  68         rcu_read_unlock();
  69
  70         return id;
  71 }
  72
  73 static inline u32 __bch2_snapshot_parent(struct bch_fs *c, u32 id)
  74 {
  75         const struct snapshot_t *s = snapshot_t(c, id);
  76         if (!s)
  77                 return 0;
  78
  79         u32 parent = s->parent;
  80         if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
  81             parent &&
  82             s->depth != snapshot_t(c, parent)->depth + 1)
  83                 panic("id %u depth=%u parent %u depth=%u\n",
  84                       id, snapshot_t(c, id)->depth,
  85                       parent, snapshot_t(c, parent)->depth);
  86
  87         return parent;
  88 }
  89
  90 static inline u32 bch2_snapshot_parent(struct bch_fs *c, u32 id)
  91 {
  92         rcu_read_lock();
  93         id = __bch2_snapshot_parent(c, id);
  94         rcu_read_unlock();
  95
  96         return id;
  97 }
  98
  99 static inline u32 bch2_snapshot_nth_parent(struct bch_fs *c, u32 id, u32 n)
 100 {
 101         rcu_read_lock();
 102         while (n--)
 103                 id = __bch2_snapshot_parent(c, id);
 104         rcu_read_unlock();
 105
 106         return id;
 107 }
 108
 109 u32 bch2_snapshot_skiplist_get(struct bch_fs *, u32);
 110
 111 static inline u32 bch2_snapshot_root(struct bch_fs *c, u32 id)
 112 {
 113         u32 parent;
 114
 115         rcu_read_lock();
 116         while ((parent = __bch2_snapshot_parent(c, id)))
 117                 id = parent;
 118         rcu_read_unlock();
 119
 120         return id;
 121 }
 122
 123 static inline u32 __bch2_snapshot_equiv(struct bch_fs *c, u32 id)
 124 {
 125         const struct snapshot_t *s = snapshot_t(c, id);
 126         return s ? s->equiv : 0;
 127 }
 128
 129 static inline u32 bch2_snapshot_equiv(struct bch_fs *c, u32 id)
 130 {
 131         rcu_read_lock();
 132         id = __bch2_snapshot_equiv(c, id);
 133         rcu_read_unlock();
 134
 135         return id;
 136 }
 137
 138 static inline int bch2_snapshot_is_internal_node(struct bch_fs *c, u32 id)
 139 {
 140         rcu_read_lock();
 141         const struct snapshot_t *s = snapshot_t(c, id);
 142         int ret = s ? s->children[0] : -BCH_ERR_invalid_snapshot_node;
 143         rcu_read_unlock();
 144
 145         return ret;
 146 }
 147
 148 static inline int bch2_snapshot_is_leaf(struct bch_fs *c, u32 id)
 149 {
 150         int ret = bch2_snapshot_is_internal_node(c, id);
 151         if (ret < 0)
 152                 return ret;
 153         return !ret;
 154 }
 155
 156 static inline u32 bch2_snapshot_depth(struct bch_fs *c, u32 parent)
 157 {
 158         u32 depth;
 159
 160         rcu_read_lock();
 161         depth = parent ? snapshot_t(c, parent)->depth + 1 : 0;
 162         rcu_read_unlock();
 163
 164         return depth;
 165 }
 166
 167 bool __bch2_snapshot_is_ancestor(struct bch_fs *, u32, u32);
 168
 169 static inline bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor)
 170 {
 171         return id == ancestor
 172                 ? true
 173                 : __bch2_snapshot_is_ancestor(c, id, ancestor);
 174 }
 175
 176 static inline bool bch2_snapshot_has_children(struct bch_fs *c, u32 id)
 177 {
 178         rcu_read_lock();
 179         const struct snapshot_t *t = snapshot_t(c, id);
 180         bool ret = t && (t->children[0]|t->children[1]) != 0;
 181         rcu_read_unlock();
 182
 183         return ret;
 184 }
 185
 186 static inline bool snapshot_list_has_id(snapshot_id_list *s, u32 id)
 187 {
 188         darray_for_each(*s, i)
 189                 if (*i == id)
 190                         return true;
 191         return false;
 192 }
 193
 194 static inline bool snapshot_list_has_ancestor(struct bch_fs *c, snapshot_id_list *s, u32 id)
 195 {
 196         darray_for_each(*s, i)
 197                 if (bch2_snapshot_is_ancestor(c, id, *i))
 198                         return true;
 199         return false;
 200 }
 201
 202 static inline int snapshot_list_add(struct bch_fs *c, snapshot_id_list *s, u32 id)
 203 {
 204         BUG_ON(snapshot_list_has_id(s, id));
 205         int ret = darray_push(s, id);
 206         if (ret)
 207                 bch_err(c, "error reallocating snapshot_id_list (size %zu)", s->size);
 208         return ret;
 209 }
 210
 211 static inline int snapshot_list_add_nodup(struct bch_fs *c, snapshot_id_list *s, u32 id)
 212 {
 213         int ret = snapshot_list_has_id(s, id)
 214                 ? 0
 215                 : darray_push(s, id);
 216         if (ret)
 217                 bch_err(c, "error reallocating snapshot_id_list (size %zu)", s->size);
 218         return ret;
 219 }
 220
 221 static inline int snapshot_list_merge(struct bch_fs *c, snapshot_id_list *dst, snapshot_id_list *src)
 222 {
 223         darray_for_each(*src, i) {
 224                 int ret = snapshot_list_add_nodup(c, dst, *i);
 225                 if (ret)
 226                         return ret;
 227         }
 228
 229         return 0;
 230 }
 231
 232 int bch2_snapshot_lookup(struct btree_trans *trans, u32 id,
 233                          struct bch_snapshot *s);
 234 int bch2_snapshot_get_subvol(struct btree_trans *, u32,
 235                              struct bch_subvolume *);
 236
 237 /* only exported for tests: */
 238 int bch2_snapshot_node_create(struct btree_trans *, u32,
 239                               u32 *, u32 *, unsigned);
 240
 241 int bch2_check_snapshot_trees(struct bch_fs *);
 242 int bch2_check_snapshots(struct bch_fs *);
 243 int bch2_reconstruct_snapshots(struct bch_fs *);
 244 int bch2_check_key_has_snapshot(struct btree_trans *, struct btree_iter *, struct bkey_s_c);
 245
 246 int bch2_snapshot_node_set_deleted(struct btree_trans *, u32);
 247 void bch2_delete_dead_snapshots_work(struct work_struct *);
 248
 249 int __bch2_key_has_snapshot_overwrites(struct btree_trans *, enum btree_id, struct bpos);
 250
 251 static inline int bch2_key_has_snapshot_overwrites(struct btree_trans *trans,
 252                                           enum btree_id id,
 253                                           struct bpos pos)
 254 {
 255         if (!btree_type_has_snapshots(id) ||
 256             bch2_snapshot_is_leaf(trans->c, pos.snapshot) > 0)
 257                 return 0;
 258
 259         return __bch2_key_has_snapshot_overwrites(trans, id, pos);
 260 }
 261
 262 int bch2_snapshots_read(struct bch_fs *);
 263 void bch2_fs_snapshots_exit(struct bch_fs *);
 264
 265 #endif /* _BCACHEFS_SNAPSHOT_H */