1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2011 STRATO. All rights reserved. 4 */ 5 6 #ifndef BTRFS_BACKREF_H 7 #define BTRFS_BACKREF_H 8 9 #include <linux/btrfs.h> 10 #include "ulist.h" 11 #include "disk-io.h" 12 #include "extent_io.h" 13 14 struct inode_fs_paths { 15 struct btrfs_path *btrfs_path; 16 struct btrfs_root *fs_root; 17 struct btrfs_data_container *fspath; 18 }; 19 20 typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root, 21 void *ctx); 22 23 int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, 24 struct btrfs_path *path, struct btrfs_key *found_key, 25 u64 *flags); 26 27 int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, 28 struct btrfs_key *key, struct btrfs_extent_item *ei, 29 u32 item_size, u64 *out_root, u8 *out_level); 30 31 int iterate_extent_inodes(struct btrfs_fs_info *fs_info, 32 u64 extent_item_objectid, 33 u64 extent_offset, int search_commit_root, 34 iterate_extent_inodes_t *iterate, void *ctx, 35 bool ignore_offset); 36 37 int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, 38 struct btrfs_path *path, 39 iterate_extent_inodes_t *iterate, void *ctx, 40 bool ignore_offset); 41 42 int paths_from_inode(u64 inum, struct inode_fs_paths *ipath); 43 44 int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, 45 struct btrfs_fs_info *fs_info, u64 bytenr, 46 u64 time_seq, struct ulist **leafs, 47 const u64 *extent_item_pos, bool ignore_offset); 48 int btrfs_find_all_roots(struct btrfs_trans_handle *trans, 49 struct btrfs_fs_info *fs_info, u64 bytenr, 50 u64 time_seq, struct ulist **roots, 51 bool skip_commit_root_sem); 52 char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, 53 u32 name_len, unsigned long name_off, 54 struct extent_buffer *eb_in, u64 parent, 55 char *dest, u32 size); 56 57 struct btrfs_data_container *init_data_container(u32 total_bytes); 58 struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, 59 struct btrfs_path *path); 60 void free_ipath(struct inode_fs_paths *ipath); 61 62 int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, 63 u64 start_off, struct btrfs_path *path, 64 struct btrfs_inode_extref **ret_extref, 65 u64 *found_off); 66 int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr, 67 struct ulist *roots, struct ulist *tmp_ulist); 68 69 int __init btrfs_prelim_ref_init(void); 70 void __cold btrfs_prelim_ref_exit(void); 71 72 struct prelim_ref { 73 struct rb_node rbnode; 74 u64 root_id; 75 struct btrfs_key key_for_search; 76 int level; 77 int count; 78 struct extent_inode_elem *inode_list; 79 u64 parent; 80 u64 wanted_disk_byte; 81 }; 82 83 /* 84 * Iterate backrefs of one extent. 85 * 86 * Now it only supports iteration of tree block in commit root. 87 */ 88 struct btrfs_backref_iter { 89 u64 bytenr; 90 struct btrfs_path *path; 91 struct btrfs_fs_info *fs_info; 92 struct btrfs_key cur_key; 93 u32 item_ptr; 94 u32 cur_ptr; 95 u32 end_ptr; 96 }; 97 98 struct btrfs_backref_iter *btrfs_backref_iter_alloc( 99 struct btrfs_fs_info *fs_info, gfp_t gfp_flag); 100 101 static inline void btrfs_backref_iter_free(struct btrfs_backref_iter *iter) 102 { 103 if (!iter) 104 return; 105 btrfs_free_path(iter->path); 106 kfree(iter); 107 } 108 109 static inline struct extent_buffer *btrfs_backref_get_eb( 110 struct btrfs_backref_iter *iter) 111 { 112 if (!iter) 113 return NULL; 114 return iter->path->nodes[0]; 115 } 116 117 /* 118 * For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data 119 * is btrfs_tree_block_info, without a btrfs_extent_inline_ref header. 120 * 121 * This helper determines if that's the case. 122 */ 123 static inline bool btrfs_backref_has_tree_block_info( 124 struct btrfs_backref_iter *iter) 125 { 126 if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY && 127 iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item)) 128 return true; 129 return false; 130 } 131 132 int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr); 133 134 int btrfs_backref_iter_next(struct btrfs_backref_iter *iter); 135 136 static inline bool btrfs_backref_iter_is_inline_ref( 137 struct btrfs_backref_iter *iter) 138 { 139 if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY || 140 iter->cur_key.type == BTRFS_METADATA_ITEM_KEY) 141 return true; 142 return false; 143 } 144 145 static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter) 146 { 147 iter->bytenr = 0; 148 iter->item_ptr = 0; 149 iter->cur_ptr = 0; 150 iter->end_ptr = 0; 151 btrfs_release_path(iter->path); 152 memset(&iter->cur_key, 0, sizeof(iter->cur_key)); 153 } 154 155 /* 156 * Backref cache related structures 157 * 158 * The whole objective of backref_cache is to build a bi-directional map 159 * of tree blocks (represented by backref_node) and all their parents. 160 */ 161 162 /* 163 * Represent a tree block in the backref cache 164 */ 165 struct btrfs_backref_node { 166 struct { 167 struct rb_node rb_node; 168 u64 bytenr; 169 }; /* Use rb_simple_node for search/insert */ 170 171 u64 new_bytenr; 172 /* Objectid of tree block owner, can be not uptodate */ 173 u64 owner; 174 /* Link to pending, changed or detached list */ 175 struct list_head list; 176 177 /* List of upper level edges, which link this node to its parents */ 178 struct list_head upper; 179 /* List of lower level edges, which link this node to its children */ 180 struct list_head lower; 181 182 /* NULL if this node is not tree root */ 183 struct btrfs_root *root; 184 /* Extent buffer got by COWing the block */ 185 struct extent_buffer *eb; 186 /* Level of the tree block */ 187 unsigned int level:8; 188 /* Is the block in a non-shareable tree */ 189 unsigned int cowonly:1; 190 /* 1 if no child node is in the cache */ 191 unsigned int lowest:1; 192 /* Is the extent buffer locked */ 193 unsigned int locked:1; 194 /* Has the block been processed */ 195 unsigned int processed:1; 196 /* Have backrefs of this block been checked */ 197 unsigned int checked:1; 198 /* 199 * 1 if corresponding block has been COWed but some upper level block 200 * pointers may not point to the new location 201 */ 202 unsigned int pending:1; 203 /* 1 if the backref node isn't connected to any other backref node */ 204 unsigned int detached:1; 205 206 /* 207 * For generic purpose backref cache, where we only care if it's a reloc 208 * root, doesn't care the source subvolid. 209 */ 210 unsigned int is_reloc_root:1; 211 }; 212 213 #define LOWER 0 214 #define UPPER 1 215 216 /* 217 * Represent an edge connecting upper and lower backref nodes. 218 */ 219 struct btrfs_backref_edge { 220 /* 221 * list[LOWER] is linked to btrfs_backref_node::upper of lower level 222 * node, and list[UPPER] is linked to btrfs_backref_node::lower of 223 * upper level node. 224 * 225 * Also, build_backref_tree() uses list[UPPER] for pending edges, before 226 * linking list[UPPER] to its upper level nodes. 227 */ 228 struct list_head list[2]; 229 230 /* Two related nodes */ 231 struct btrfs_backref_node *node[2]; 232 }; 233 234 struct btrfs_backref_cache { 235 /* Red black tree of all backref nodes in the cache */ 236 struct rb_root rb_root; 237 /* For passing backref nodes to btrfs_reloc_cow_block */ 238 struct btrfs_backref_node *path[BTRFS_MAX_LEVEL]; 239 /* 240 * List of blocks that have been COWed but some block pointers in upper 241 * level blocks may not reflect the new location 242 */ 243 struct list_head pending[BTRFS_MAX_LEVEL]; 244 /* List of backref nodes with no child node */ 245 struct list_head leaves; 246 /* List of blocks that have been COWed in current transaction */ 247 struct list_head changed; 248 /* List of detached backref node. */ 249 struct list_head detached; 250 251 u64 last_trans; 252 253 int nr_nodes; 254 int nr_edges; 255 256 /* List of unchecked backref edges during backref cache build */ 257 struct list_head pending_edge; 258 259 /* List of useless backref nodes during backref cache build */ 260 struct list_head useless_node; 261 262 struct btrfs_fs_info *fs_info; 263 264 /* 265 * Whether this cache is for relocation 266 * 267 * Reloction backref cache require more info for reloc root compared 268 * to generic backref cache. 269 */ 270 unsigned int is_reloc; 271 }; 272 273 void btrfs_backref_init_cache(struct btrfs_fs_info *fs_info, 274 struct btrfs_backref_cache *cache, int is_reloc); 275 struct btrfs_backref_node *btrfs_backref_alloc_node( 276 struct btrfs_backref_cache *cache, u64 bytenr, int level); 277 struct btrfs_backref_edge *btrfs_backref_alloc_edge( 278 struct btrfs_backref_cache *cache); 279 280 #define LINK_LOWER (1 << 0) 281 #define LINK_UPPER (1 << 1) 282 static inline void btrfs_backref_link_edge(struct btrfs_backref_edge *edge, 283 struct btrfs_backref_node *lower, 284 struct btrfs_backref_node *upper, 285 int link_which) 286 { 287 ASSERT(upper && lower && upper->level == lower->level + 1); 288 edge->node[LOWER] = lower; 289 edge->node[UPPER] = upper; 290 if (link_which & LINK_LOWER) 291 list_add_tail(&edge->list[LOWER], &lower->upper); 292 if (link_which & LINK_UPPER) 293 list_add_tail(&edge->list[UPPER], &upper->lower); 294 } 295 296 static inline void btrfs_backref_free_node(struct btrfs_backref_cache *cache, 297 struct btrfs_backref_node *node) 298 { 299 if (node) { 300 ASSERT(list_empty(&node->list)); 301 ASSERT(list_empty(&node->lower)); 302 ASSERT(node->eb == NULL); 303 cache->nr_nodes--; 304 btrfs_put_root(node->root); 305 kfree(node); 306 } 307 } 308 309 static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache, 310 struct btrfs_backref_edge *edge) 311 { 312 if (edge) { 313 cache->nr_edges--; 314 kfree(edge); 315 } 316 } 317 318 static inline void btrfs_backref_unlock_node_buffer( 319 struct btrfs_backref_node *node) 320 { 321 if (node->locked) { 322 btrfs_tree_unlock(node->eb); 323 node->locked = 0; 324 } 325 } 326 327 static inline void btrfs_backref_drop_node_buffer( 328 struct btrfs_backref_node *node) 329 { 330 if (node->eb) { 331 btrfs_backref_unlock_node_buffer(node); 332 free_extent_buffer(node->eb); 333 node->eb = NULL; 334 } 335 } 336 337 /* 338 * Drop the backref node from cache without cleaning up its children 339 * edges. 340 * 341 * This can only be called on node without parent edges. 342 * The children edges are still kept as is. 343 */ 344 static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree, 345 struct btrfs_backref_node *node) 346 { 347 ASSERT(list_empty(&node->upper)); 348 349 btrfs_backref_drop_node_buffer(node); 350 list_del_init(&node->list); 351 list_del_init(&node->lower); 352 if (!RB_EMPTY_NODE(&node->rb_node)) 353 rb_erase(&node->rb_node, &tree->rb_root); 354 btrfs_backref_free_node(tree, node); 355 } 356 357 void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache, 358 struct btrfs_backref_node *node); 359 360 void btrfs_backref_release_cache(struct btrfs_backref_cache *cache); 361 362 static inline void btrfs_backref_panic(struct btrfs_fs_info *fs_info, 363 u64 bytenr, int errno) 364 { 365 btrfs_panic(fs_info, errno, 366 "Inconsistency in backref cache found at offset %llu", 367 bytenr); 368 } 369 370 int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache, 371 struct btrfs_path *path, 372 struct btrfs_backref_iter *iter, 373 struct btrfs_key *node_key, 374 struct btrfs_backref_node *cur); 375 376 int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache, 377 struct btrfs_backref_node *start); 378 379 void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache, 380 struct btrfs_backref_node *node); 381 382 #endif 383