| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Copyright (C) 2007 Oracle. All rights reserved. |
| 4 | */ |
| 5 | |
| 6 | #include <linux/sched.h> |
| 7 | #include <linux/sched/signal.h> |
| 8 | #include <linux/pagemap.h> |
| 9 | #include <linux/writeback.h> |
| 10 | #include <linux/blkdev.h> |
| 11 | #include <linux/sort.h> |
| 12 | #include <linux/rcupdate.h> |
| 13 | #include <linux/kthread.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/ratelimit.h> |
| 16 | #include <linux/percpu_counter.h> |
| 17 | #include <linux/lockdep.h> |
| 18 | #include <linux/crc32c.h> |
| 19 | #include "ctree.h" |
| 20 | #include "extent-tree.h" |
| 21 | #include "transaction.h" |
| 22 | #include "disk-io.h" |
| 23 | #include "print-tree.h" |
| 24 | #include "volumes.h" |
| 25 | #include "raid56.h" |
| 26 | #include "locking.h" |
| 27 | #include "free-space-cache.h" |
| 28 | #include "free-space-tree.h" |
| 29 | #include "qgroup.h" |
| 30 | #include "ref-verify.h" |
| 31 | #include "space-info.h" |
| 32 | #include "block-rsv.h" |
| 33 | #include "discard.h" |
| 34 | #include "zoned.h" |
| 35 | #include "dev-replace.h" |
| 36 | #include "fs.h" |
| 37 | #include "accessors.h" |
| 38 | #include "root-tree.h" |
| 39 | #include "file-item.h" |
| 40 | #include "orphan.h" |
| 41 | #include "tree-checker.h" |
| 42 | #include "raid-stripe-tree.h" |
| 43 | |
| 44 | #undef SCRAMBLE_DELAYED_REFS |
| 45 | |
| 46 | |
| 47 | static int __btrfs_free_extent(struct btrfs_trans_handle *trans, |
| 48 | struct btrfs_delayed_ref_head *href, |
| 49 | struct btrfs_delayed_ref_node *node, |
| 50 | struct btrfs_delayed_extent_op *extra_op); |
| 51 | static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, |
| 52 | struct extent_buffer *leaf, |
| 53 | struct btrfs_extent_item *ei); |
| 54 | static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, |
| 55 | u64 parent, u64 root_objectid, |
| 56 | u64 flags, u64 owner, u64 offset, |
| 57 | struct btrfs_key *ins, int ref_mod, u64 oref_root); |
| 58 | static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, |
| 59 | struct btrfs_delayed_ref_node *node, |
| 60 | struct btrfs_delayed_extent_op *extent_op); |
| 61 | static int find_next_key(struct btrfs_path *path, int level, |
| 62 | struct btrfs_key *key); |
| 63 | |
| 64 | static int block_group_bits(struct btrfs_block_group *cache, u64 bits) |
| 65 | { |
| 66 | return (cache->flags & bits) == bits; |
| 67 | } |
| 68 | |
| 69 | /* simple helper to search for an existing data extent at a given offset */ |
| 70 | int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len) |
| 71 | { |
| 72 | struct btrfs_root *root = btrfs_extent_root(fs_info, start); |
| 73 | int ret; |
| 74 | struct btrfs_key key; |
| 75 | struct btrfs_path *path; |
| 76 | |
| 77 | path = btrfs_alloc_path(); |
| 78 | if (!path) |
| 79 | return -ENOMEM; |
| 80 | |
| 81 | key.objectid = start; |
| 82 | key.offset = len; |
| 83 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 84 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 85 | btrfs_free_path(path); |
| 86 | return ret; |
| 87 | } |
| 88 | |
| 89 | /* |
| 90 | * helper function to lookup reference count and flags of a tree block. |
| 91 | * |
| 92 | * the head node for delayed ref is used to store the sum of all the |
| 93 | * reference count modifications queued up in the rbtree. the head |
| 94 | * node may also store the extent flags to set. This way you can check |
| 95 | * to see what the reference count and extent flags would be if all of |
| 96 | * the delayed refs are not processed. |
| 97 | */ |
| 98 | int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans, |
| 99 | struct btrfs_fs_info *fs_info, u64 bytenr, |
| 100 | u64 offset, int metadata, u64 *refs, u64 *flags, |
| 101 | u64 *owning_root) |
| 102 | { |
| 103 | struct btrfs_root *extent_root; |
| 104 | struct btrfs_delayed_ref_head *head; |
| 105 | struct btrfs_delayed_ref_root *delayed_refs; |
| 106 | struct btrfs_path *path; |
| 107 | struct btrfs_key key; |
| 108 | u64 num_refs; |
| 109 | u64 extent_flags; |
| 110 | u64 owner = 0; |
| 111 | int ret; |
| 112 | |
| 113 | /* |
| 114 | * If we don't have skinny metadata, don't bother doing anything |
| 115 | * different |
| 116 | */ |
| 117 | if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) { |
| 118 | offset = fs_info->nodesize; |
| 119 | metadata = 0; |
| 120 | } |
| 121 | |
| 122 | path = btrfs_alloc_path(); |
| 123 | if (!path) |
| 124 | return -ENOMEM; |
| 125 | |
| 126 | search_again: |
| 127 | key.objectid = bytenr; |
| 128 | key.offset = offset; |
| 129 | if (metadata) |
| 130 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 131 | else |
| 132 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 133 | |
| 134 | extent_root = btrfs_extent_root(fs_info, bytenr); |
| 135 | ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| 136 | if (ret < 0) |
| 137 | goto out_free; |
| 138 | |
| 139 | if (ret > 0 && key.type == BTRFS_METADATA_ITEM_KEY) { |
| 140 | if (path->slots[0]) { |
| 141 | path->slots[0]--; |
| 142 | btrfs_item_key_to_cpu(path->nodes[0], &key, |
| 143 | path->slots[0]); |
| 144 | if (key.objectid == bytenr && |
| 145 | key.type == BTRFS_EXTENT_ITEM_KEY && |
| 146 | key.offset == fs_info->nodesize) |
| 147 | ret = 0; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | if (ret == 0) { |
| 152 | struct extent_buffer *leaf = path->nodes[0]; |
| 153 | struct btrfs_extent_item *ei; |
| 154 | const u32 item_size = btrfs_item_size(leaf, path->slots[0]); |
| 155 | |
| 156 | if (unlikely(item_size < sizeof(*ei))) { |
| 157 | ret = -EUCLEAN; |
| 158 | btrfs_err(fs_info, |
| 159 | "unexpected extent item size, has %u expect >= %zu", |
| 160 | item_size, sizeof(*ei)); |
| 161 | btrfs_abort_transaction(trans, ret); |
| 162 | goto out_free; |
| 163 | } |
| 164 | |
| 165 | ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 166 | num_refs = btrfs_extent_refs(leaf, ei); |
| 167 | if (unlikely(num_refs == 0)) { |
| 168 | ret = -EUCLEAN; |
| 169 | btrfs_err(fs_info, |
| 170 | "unexpected zero reference count for extent item (%llu %u %llu)", |
| 171 | key.objectid, key.type, key.offset); |
| 172 | btrfs_abort_transaction(trans, ret); |
| 173 | goto out_free; |
| 174 | } |
| 175 | extent_flags = btrfs_extent_flags(leaf, ei); |
| 176 | owner = btrfs_get_extent_owner_root(fs_info, leaf, path->slots[0]); |
| 177 | } else { |
| 178 | num_refs = 0; |
| 179 | extent_flags = 0; |
| 180 | ret = 0; |
| 181 | } |
| 182 | |
| 183 | delayed_refs = &trans->transaction->delayed_refs; |
| 184 | spin_lock(&delayed_refs->lock); |
| 185 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
| 186 | if (head) { |
| 187 | if (!mutex_trylock(&head->mutex)) { |
| 188 | refcount_inc(&head->refs); |
| 189 | spin_unlock(&delayed_refs->lock); |
| 190 | |
| 191 | btrfs_release_path(path); |
| 192 | |
| 193 | /* |
| 194 | * Mutex was contended, block until it's released and try |
| 195 | * again |
| 196 | */ |
| 197 | mutex_lock(&head->mutex); |
| 198 | mutex_unlock(&head->mutex); |
| 199 | btrfs_put_delayed_ref_head(head); |
| 200 | goto search_again; |
| 201 | } |
| 202 | spin_lock(&head->lock); |
| 203 | if (head->extent_op && head->extent_op->update_flags) |
| 204 | extent_flags |= head->extent_op->flags_to_set; |
| 205 | |
| 206 | num_refs += head->ref_mod; |
| 207 | spin_unlock(&head->lock); |
| 208 | mutex_unlock(&head->mutex); |
| 209 | } |
| 210 | spin_unlock(&delayed_refs->lock); |
| 211 | |
| 212 | WARN_ON(num_refs == 0); |
| 213 | if (refs) |
| 214 | *refs = num_refs; |
| 215 | if (flags) |
| 216 | *flags = extent_flags; |
| 217 | if (owning_root) |
| 218 | *owning_root = owner; |
| 219 | out_free: |
| 220 | btrfs_free_path(path); |
| 221 | return ret; |
| 222 | } |
| 223 | |
| 224 | /* |
| 225 | * Back reference rules. Back refs have three main goals: |
| 226 | * |
| 227 | * 1) differentiate between all holders of references to an extent so that |
| 228 | * when a reference is dropped we can make sure it was a valid reference |
| 229 | * before freeing the extent. |
| 230 | * |
| 231 | * 2) Provide enough information to quickly find the holders of an extent |
| 232 | * if we notice a given block is corrupted or bad. |
| 233 | * |
| 234 | * 3) Make it easy to migrate blocks for FS shrinking or storage pool |
| 235 | * maintenance. This is actually the same as #2, but with a slightly |
| 236 | * different use case. |
| 237 | * |
| 238 | * There are two kinds of back refs. The implicit back refs is optimized |
| 239 | * for pointers in non-shared tree blocks. For a given pointer in a block, |
| 240 | * back refs of this kind provide information about the block's owner tree |
| 241 | * and the pointer's key. These information allow us to find the block by |
| 242 | * b-tree searching. The full back refs is for pointers in tree blocks not |
| 243 | * referenced by their owner trees. The location of tree block is recorded |
| 244 | * in the back refs. Actually the full back refs is generic, and can be |
| 245 | * used in all cases the implicit back refs is used. The major shortcoming |
| 246 | * of the full back refs is its overhead. Every time a tree block gets |
| 247 | * COWed, we have to update back refs entry for all pointers in it. |
| 248 | * |
| 249 | * For a newly allocated tree block, we use implicit back refs for |
| 250 | * pointers in it. This means most tree related operations only involve |
| 251 | * implicit back refs. For a tree block created in old transaction, the |
| 252 | * only way to drop a reference to it is COW it. So we can detect the |
| 253 | * event that tree block loses its owner tree's reference and do the |
| 254 | * back refs conversion. |
| 255 | * |
| 256 | * When a tree block is COWed through a tree, there are four cases: |
| 257 | * |
| 258 | * The reference count of the block is one and the tree is the block's |
| 259 | * owner tree. Nothing to do in this case. |
| 260 | * |
| 261 | * The reference count of the block is one and the tree is not the |
| 262 | * block's owner tree. In this case, full back refs is used for pointers |
| 263 | * in the block. Remove these full back refs, add implicit back refs for |
| 264 | * every pointers in the new block. |
| 265 | * |
| 266 | * The reference count of the block is greater than one and the tree is |
| 267 | * the block's owner tree. In this case, implicit back refs is used for |
| 268 | * pointers in the block. Add full back refs for every pointers in the |
| 269 | * block, increase lower level extents' reference counts. The original |
| 270 | * implicit back refs are entailed to the new block. |
| 271 | * |
| 272 | * The reference count of the block is greater than one and the tree is |
| 273 | * not the block's owner tree. Add implicit back refs for every pointer in |
| 274 | * the new block, increase lower level extents' reference count. |
| 275 | * |
| 276 | * Back Reference Key composing: |
| 277 | * |
| 278 | * The key objectid corresponds to the first byte in the extent, |
| 279 | * The key type is used to differentiate between types of back refs. |
| 280 | * There are different meanings of the key offset for different types |
| 281 | * of back refs. |
| 282 | * |
| 283 | * File extents can be referenced by: |
| 284 | * |
| 285 | * - multiple snapshots, subvolumes, or different generations in one subvol |
| 286 | * - different files inside a single subvolume |
| 287 | * - different offsets inside a file (bookend extents in file.c) |
| 288 | * |
| 289 | * The extent ref structure for the implicit back refs has fields for: |
| 290 | * |
| 291 | * - Objectid of the subvolume root |
| 292 | * - objectid of the file holding the reference |
| 293 | * - original offset in the file |
| 294 | * - how many bookend extents |
| 295 | * |
| 296 | * The key offset for the implicit back refs is hash of the first |
| 297 | * three fields. |
| 298 | * |
| 299 | * The extent ref structure for the full back refs has field for: |
| 300 | * |
| 301 | * - number of pointers in the tree leaf |
| 302 | * |
| 303 | * The key offset for the implicit back refs is the first byte of |
| 304 | * the tree leaf |
| 305 | * |
| 306 | * When a file extent is allocated, The implicit back refs is used. |
| 307 | * the fields are filled in: |
| 308 | * |
| 309 | * (root_key.objectid, inode objectid, offset in file, 1) |
| 310 | * |
| 311 | * When a file extent is removed file truncation, we find the |
| 312 | * corresponding implicit back refs and check the following fields: |
| 313 | * |
| 314 | * (btrfs_header_owner(leaf), inode objectid, offset in file) |
| 315 | * |
| 316 | * Btree extents can be referenced by: |
| 317 | * |
| 318 | * - Different subvolumes |
| 319 | * |
| 320 | * Both the implicit back refs and the full back refs for tree blocks |
| 321 | * only consist of key. The key offset for the implicit back refs is |
| 322 | * objectid of block's owner tree. The key offset for the full back refs |
| 323 | * is the first byte of parent block. |
| 324 | * |
| 325 | * When implicit back refs is used, information about the lowest key and |
| 326 | * level of the tree block are required. These information are stored in |
| 327 | * tree block info structure. |
| 328 | */ |
| 329 | |
| 330 | /* |
| 331 | * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required, |
| 332 | * is_data == BTRFS_REF_TYPE_DATA, data type is requiried, |
| 333 | * is_data == BTRFS_REF_TYPE_ANY, either type is OK. |
| 334 | */ |
| 335 | int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb, |
| 336 | struct btrfs_extent_inline_ref *iref, |
| 337 | enum btrfs_inline_ref_type is_data) |
| 338 | { |
| 339 | struct btrfs_fs_info *fs_info = eb->fs_info; |
| 340 | int type = btrfs_extent_inline_ref_type(eb, iref); |
| 341 | u64 offset = btrfs_extent_inline_ref_offset(eb, iref); |
| 342 | |
| 343 | if (type == BTRFS_EXTENT_OWNER_REF_KEY) { |
| 344 | ASSERT(btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)); |
| 345 | return type; |
| 346 | } |
| 347 | |
| 348 | if (type == BTRFS_TREE_BLOCK_REF_KEY || |
| 349 | type == BTRFS_SHARED_BLOCK_REF_KEY || |
| 350 | type == BTRFS_SHARED_DATA_REF_KEY || |
| 351 | type == BTRFS_EXTENT_DATA_REF_KEY) { |
| 352 | if (is_data == BTRFS_REF_TYPE_BLOCK) { |
| 353 | if (type == BTRFS_TREE_BLOCK_REF_KEY) |
| 354 | return type; |
| 355 | if (type == BTRFS_SHARED_BLOCK_REF_KEY) { |
| 356 | ASSERT(fs_info); |
| 357 | /* |
| 358 | * Every shared one has parent tree block, |
| 359 | * which must be aligned to sector size. |
| 360 | */ |
| 361 | if (offset && IS_ALIGNED(offset, fs_info->sectorsize)) |
| 362 | return type; |
| 363 | } |
| 364 | } else if (is_data == BTRFS_REF_TYPE_DATA) { |
| 365 | if (type == BTRFS_EXTENT_DATA_REF_KEY) |
| 366 | return type; |
| 367 | if (type == BTRFS_SHARED_DATA_REF_KEY) { |
| 368 | ASSERT(fs_info); |
| 369 | /* |
| 370 | * Every shared one has parent tree block, |
| 371 | * which must be aligned to sector size. |
| 372 | */ |
| 373 | if (offset && |
| 374 | IS_ALIGNED(offset, fs_info->sectorsize)) |
| 375 | return type; |
| 376 | } |
| 377 | } else { |
| 378 | ASSERT(is_data == BTRFS_REF_TYPE_ANY); |
| 379 | return type; |
| 380 | } |
| 381 | } |
| 382 | |
| 383 | WARN_ON(1); |
| 384 | btrfs_print_leaf(eb); |
| 385 | btrfs_err(fs_info, |
| 386 | "eb %llu iref 0x%lx invalid extent inline ref type %d", |
| 387 | eb->start, (unsigned long)iref, type); |
| 388 | |
| 389 | return BTRFS_REF_TYPE_INVALID; |
| 390 | } |
| 391 | |
| 392 | u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset) |
| 393 | { |
| 394 | u32 high_crc = ~(u32)0; |
| 395 | u32 low_crc = ~(u32)0; |
| 396 | __le64 lenum; |
| 397 | |
| 398 | lenum = cpu_to_le64(root_objectid); |
| 399 | high_crc = crc32c(high_crc, &lenum, sizeof(lenum)); |
| 400 | lenum = cpu_to_le64(owner); |
| 401 | low_crc = crc32c(low_crc, &lenum, sizeof(lenum)); |
| 402 | lenum = cpu_to_le64(offset); |
| 403 | low_crc = crc32c(low_crc, &lenum, sizeof(lenum)); |
| 404 | |
| 405 | return ((u64)high_crc << 31) ^ (u64)low_crc; |
| 406 | } |
| 407 | |
| 408 | static u64 hash_extent_data_ref_item(struct extent_buffer *leaf, |
| 409 | struct btrfs_extent_data_ref *ref) |
| 410 | { |
| 411 | return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref), |
| 412 | btrfs_extent_data_ref_objectid(leaf, ref), |
| 413 | btrfs_extent_data_ref_offset(leaf, ref)); |
| 414 | } |
| 415 | |
| 416 | static int match_extent_data_ref(struct extent_buffer *leaf, |
| 417 | struct btrfs_extent_data_ref *ref, |
| 418 | u64 root_objectid, u64 owner, u64 offset) |
| 419 | { |
| 420 | if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid || |
| 421 | btrfs_extent_data_ref_objectid(leaf, ref) != owner || |
| 422 | btrfs_extent_data_ref_offset(leaf, ref) != offset) |
| 423 | return 0; |
| 424 | return 1; |
| 425 | } |
| 426 | |
| 427 | static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans, |
| 428 | struct btrfs_path *path, |
| 429 | u64 bytenr, u64 parent, |
| 430 | u64 root_objectid, |
| 431 | u64 owner, u64 offset) |
| 432 | { |
| 433 | struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr); |
| 434 | struct btrfs_key key; |
| 435 | struct btrfs_extent_data_ref *ref; |
| 436 | struct extent_buffer *leaf; |
| 437 | u32 nritems; |
| 438 | int recow; |
| 439 | int ret; |
| 440 | |
| 441 | key.objectid = bytenr; |
| 442 | if (parent) { |
| 443 | key.type = BTRFS_SHARED_DATA_REF_KEY; |
| 444 | key.offset = parent; |
| 445 | } else { |
| 446 | key.type = BTRFS_EXTENT_DATA_REF_KEY; |
| 447 | key.offset = hash_extent_data_ref(root_objectid, |
| 448 | owner, offset); |
| 449 | } |
| 450 | again: |
| 451 | recow = 0; |
| 452 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| 453 | if (ret < 0) |
| 454 | return ret; |
| 455 | |
| 456 | if (parent) { |
| 457 | if (ret) |
| 458 | return -ENOENT; |
| 459 | return 0; |
| 460 | } |
| 461 | |
| 462 | ret = -ENOENT; |
| 463 | leaf = path->nodes[0]; |
| 464 | nritems = btrfs_header_nritems(leaf); |
| 465 | while (1) { |
| 466 | if (path->slots[0] >= nritems) { |
| 467 | ret = btrfs_next_leaf(root, path); |
| 468 | if (ret) { |
| 469 | if (ret > 0) |
| 470 | return -ENOENT; |
| 471 | return ret; |
| 472 | } |
| 473 | |
| 474 | leaf = path->nodes[0]; |
| 475 | nritems = btrfs_header_nritems(leaf); |
| 476 | recow = 1; |
| 477 | } |
| 478 | |
| 479 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 480 | if (key.objectid != bytenr || |
| 481 | key.type != BTRFS_EXTENT_DATA_REF_KEY) |
| 482 | goto fail; |
| 483 | |
| 484 | ref = btrfs_item_ptr(leaf, path->slots[0], |
| 485 | struct btrfs_extent_data_ref); |
| 486 | |
| 487 | if (match_extent_data_ref(leaf, ref, root_objectid, |
| 488 | owner, offset)) { |
| 489 | if (recow) { |
| 490 | btrfs_release_path(path); |
| 491 | goto again; |
| 492 | } |
| 493 | ret = 0; |
| 494 | break; |
| 495 | } |
| 496 | path->slots[0]++; |
| 497 | } |
| 498 | fail: |
| 499 | return ret; |
| 500 | } |
| 501 | |
| 502 | static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans, |
| 503 | struct btrfs_path *path, |
| 504 | struct btrfs_delayed_ref_node *node, |
| 505 | u64 bytenr) |
| 506 | { |
| 507 | struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr); |
| 508 | struct btrfs_key key; |
| 509 | struct extent_buffer *leaf; |
| 510 | u64 owner = btrfs_delayed_ref_owner(node); |
| 511 | u64 offset = btrfs_delayed_ref_offset(node); |
| 512 | u32 size; |
| 513 | u32 num_refs; |
| 514 | int ret; |
| 515 | |
| 516 | key.objectid = bytenr; |
| 517 | if (node->parent) { |
| 518 | key.type = BTRFS_SHARED_DATA_REF_KEY; |
| 519 | key.offset = node->parent; |
| 520 | size = sizeof(struct btrfs_shared_data_ref); |
| 521 | } else { |
| 522 | key.type = BTRFS_EXTENT_DATA_REF_KEY; |
| 523 | key.offset = hash_extent_data_ref(node->ref_root, owner, offset); |
| 524 | size = sizeof(struct btrfs_extent_data_ref); |
| 525 | } |
| 526 | |
| 527 | ret = btrfs_insert_empty_item(trans, root, path, &key, size); |
| 528 | if (ret && ret != -EEXIST) |
| 529 | goto fail; |
| 530 | |
| 531 | leaf = path->nodes[0]; |
| 532 | if (node->parent) { |
| 533 | struct btrfs_shared_data_ref *ref; |
| 534 | ref = btrfs_item_ptr(leaf, path->slots[0], |
| 535 | struct btrfs_shared_data_ref); |
| 536 | if (ret == 0) { |
| 537 | btrfs_set_shared_data_ref_count(leaf, ref, node->ref_mod); |
| 538 | } else { |
| 539 | num_refs = btrfs_shared_data_ref_count(leaf, ref); |
| 540 | num_refs += node->ref_mod; |
| 541 | btrfs_set_shared_data_ref_count(leaf, ref, num_refs); |
| 542 | } |
| 543 | } else { |
| 544 | struct btrfs_extent_data_ref *ref; |
| 545 | while (ret == -EEXIST) { |
| 546 | ref = btrfs_item_ptr(leaf, path->slots[0], |
| 547 | struct btrfs_extent_data_ref); |
| 548 | if (match_extent_data_ref(leaf, ref, node->ref_root, |
| 549 | owner, offset)) |
| 550 | break; |
| 551 | btrfs_release_path(path); |
| 552 | key.offset++; |
| 553 | ret = btrfs_insert_empty_item(trans, root, path, &key, |
| 554 | size); |
| 555 | if (ret && ret != -EEXIST) |
| 556 | goto fail; |
| 557 | |
| 558 | leaf = path->nodes[0]; |
| 559 | } |
| 560 | ref = btrfs_item_ptr(leaf, path->slots[0], |
| 561 | struct btrfs_extent_data_ref); |
| 562 | if (ret == 0) { |
| 563 | btrfs_set_extent_data_ref_root(leaf, ref, node->ref_root); |
| 564 | btrfs_set_extent_data_ref_objectid(leaf, ref, owner); |
| 565 | btrfs_set_extent_data_ref_offset(leaf, ref, offset); |
| 566 | btrfs_set_extent_data_ref_count(leaf, ref, node->ref_mod); |
| 567 | } else { |
| 568 | num_refs = btrfs_extent_data_ref_count(leaf, ref); |
| 569 | num_refs += node->ref_mod; |
| 570 | btrfs_set_extent_data_ref_count(leaf, ref, num_refs); |
| 571 | } |
| 572 | } |
| 573 | btrfs_mark_buffer_dirty(trans, leaf); |
| 574 | ret = 0; |
| 575 | fail: |
| 576 | btrfs_release_path(path); |
| 577 | return ret; |
| 578 | } |
| 579 | |
| 580 | static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, |
| 581 | struct btrfs_root *root, |
| 582 | struct btrfs_path *path, |
| 583 | int refs_to_drop) |
| 584 | { |
| 585 | struct btrfs_key key; |
| 586 | struct btrfs_extent_data_ref *ref1 = NULL; |
| 587 | struct btrfs_shared_data_ref *ref2 = NULL; |
| 588 | struct extent_buffer *leaf; |
| 589 | u32 num_refs = 0; |
| 590 | int ret = 0; |
| 591 | |
| 592 | leaf = path->nodes[0]; |
| 593 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 594 | |
| 595 | if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { |
| 596 | ref1 = btrfs_item_ptr(leaf, path->slots[0], |
| 597 | struct btrfs_extent_data_ref); |
| 598 | num_refs = btrfs_extent_data_ref_count(leaf, ref1); |
| 599 | } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { |
| 600 | ref2 = btrfs_item_ptr(leaf, path->slots[0], |
| 601 | struct btrfs_shared_data_ref); |
| 602 | num_refs = btrfs_shared_data_ref_count(leaf, ref2); |
| 603 | } else { |
| 604 | btrfs_err(trans->fs_info, |
| 605 | "unrecognized backref key (%llu %u %llu)", |
| 606 | key.objectid, key.type, key.offset); |
| 607 | btrfs_abort_transaction(trans, -EUCLEAN); |
| 608 | return -EUCLEAN; |
| 609 | } |
| 610 | |
| 611 | BUG_ON(num_refs < refs_to_drop); |
| 612 | num_refs -= refs_to_drop; |
| 613 | |
| 614 | if (num_refs == 0) { |
| 615 | ret = btrfs_del_item(trans, root, path); |
| 616 | } else { |
| 617 | if (key.type == BTRFS_EXTENT_DATA_REF_KEY) |
| 618 | btrfs_set_extent_data_ref_count(leaf, ref1, num_refs); |
| 619 | else if (key.type == BTRFS_SHARED_DATA_REF_KEY) |
| 620 | btrfs_set_shared_data_ref_count(leaf, ref2, num_refs); |
| 621 | btrfs_mark_buffer_dirty(trans, leaf); |
| 622 | } |
| 623 | return ret; |
| 624 | } |
| 625 | |
| 626 | static noinline u32 extent_data_ref_count(struct btrfs_path *path, |
| 627 | struct btrfs_extent_inline_ref *iref) |
| 628 | { |
| 629 | struct btrfs_key key; |
| 630 | struct extent_buffer *leaf; |
| 631 | struct btrfs_extent_data_ref *ref1; |
| 632 | struct btrfs_shared_data_ref *ref2; |
| 633 | u32 num_refs = 0; |
| 634 | int type; |
| 635 | |
| 636 | leaf = path->nodes[0]; |
| 637 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 638 | |
| 639 | if (iref) { |
| 640 | /* |
| 641 | * If type is invalid, we should have bailed out earlier than |
| 642 | * this call. |
| 643 | */ |
| 644 | type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA); |
| 645 | ASSERT(type != BTRFS_REF_TYPE_INVALID); |
| 646 | if (type == BTRFS_EXTENT_DATA_REF_KEY) { |
| 647 | ref1 = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 648 | num_refs = btrfs_extent_data_ref_count(leaf, ref1); |
| 649 | } else { |
| 650 | ref2 = (struct btrfs_shared_data_ref *)(iref + 1); |
| 651 | num_refs = btrfs_shared_data_ref_count(leaf, ref2); |
| 652 | } |
| 653 | } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { |
| 654 | ref1 = btrfs_item_ptr(leaf, path->slots[0], |
| 655 | struct btrfs_extent_data_ref); |
| 656 | num_refs = btrfs_extent_data_ref_count(leaf, ref1); |
| 657 | } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { |
| 658 | ref2 = btrfs_item_ptr(leaf, path->slots[0], |
| 659 | struct btrfs_shared_data_ref); |
| 660 | num_refs = btrfs_shared_data_ref_count(leaf, ref2); |
| 661 | } else { |
| 662 | WARN_ON(1); |
| 663 | } |
| 664 | return num_refs; |
| 665 | } |
| 666 | |
| 667 | static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans, |
| 668 | struct btrfs_path *path, |
| 669 | u64 bytenr, u64 parent, |
| 670 | u64 root_objectid) |
| 671 | { |
| 672 | struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr); |
| 673 | struct btrfs_key key; |
| 674 | int ret; |
| 675 | |
| 676 | key.objectid = bytenr; |
| 677 | if (parent) { |
| 678 | key.type = BTRFS_SHARED_BLOCK_REF_KEY; |
| 679 | key.offset = parent; |
| 680 | } else { |
| 681 | key.type = BTRFS_TREE_BLOCK_REF_KEY; |
| 682 | key.offset = root_objectid; |
| 683 | } |
| 684 | |
| 685 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| 686 | if (ret > 0) |
| 687 | ret = -ENOENT; |
| 688 | return ret; |
| 689 | } |
| 690 | |
| 691 | static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans, |
| 692 | struct btrfs_path *path, |
| 693 | struct btrfs_delayed_ref_node *node, |
| 694 | u64 bytenr) |
| 695 | { |
| 696 | struct btrfs_root *root = btrfs_extent_root(trans->fs_info, bytenr); |
| 697 | struct btrfs_key key; |
| 698 | int ret; |
| 699 | |
| 700 | key.objectid = bytenr; |
| 701 | if (node->parent) { |
| 702 | key.type = BTRFS_SHARED_BLOCK_REF_KEY; |
| 703 | key.offset = node->parent; |
| 704 | } else { |
| 705 | key.type = BTRFS_TREE_BLOCK_REF_KEY; |
| 706 | key.offset = node->ref_root; |
| 707 | } |
| 708 | |
| 709 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); |
| 710 | btrfs_release_path(path); |
| 711 | return ret; |
| 712 | } |
| 713 | |
| 714 | static inline int extent_ref_type(u64 parent, u64 owner) |
| 715 | { |
| 716 | int type; |
| 717 | if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| 718 | if (parent > 0) |
| 719 | type = BTRFS_SHARED_BLOCK_REF_KEY; |
| 720 | else |
| 721 | type = BTRFS_TREE_BLOCK_REF_KEY; |
| 722 | } else { |
| 723 | if (parent > 0) |
| 724 | type = BTRFS_SHARED_DATA_REF_KEY; |
| 725 | else |
| 726 | type = BTRFS_EXTENT_DATA_REF_KEY; |
| 727 | } |
| 728 | return type; |
| 729 | } |
| 730 | |
| 731 | static int find_next_key(struct btrfs_path *path, int level, |
| 732 | struct btrfs_key *key) |
| 733 | |
| 734 | { |
| 735 | for (; level < BTRFS_MAX_LEVEL; level++) { |
| 736 | if (!path->nodes[level]) |
| 737 | break; |
| 738 | if (path->slots[level] + 1 >= |
| 739 | btrfs_header_nritems(path->nodes[level])) |
| 740 | continue; |
| 741 | if (level == 0) |
| 742 | btrfs_item_key_to_cpu(path->nodes[level], key, |
| 743 | path->slots[level] + 1); |
| 744 | else |
| 745 | btrfs_node_key_to_cpu(path->nodes[level], key, |
| 746 | path->slots[level] + 1); |
| 747 | return 0; |
| 748 | } |
| 749 | return 1; |
| 750 | } |
| 751 | |
| 752 | /* |
| 753 | * look for inline back ref. if back ref is found, *ref_ret is set |
| 754 | * to the address of inline back ref, and 0 is returned. |
| 755 | * |
| 756 | * if back ref isn't found, *ref_ret is set to the address where it |
| 757 | * should be inserted, and -ENOENT is returned. |
| 758 | * |
| 759 | * if insert is true and there are too many inline back refs, the path |
| 760 | * points to the extent item, and -EAGAIN is returned. |
| 761 | * |
| 762 | * NOTE: inline back refs are ordered in the same way that back ref |
| 763 | * items in the tree are ordered. |
| 764 | */ |
| 765 | static noinline_for_stack |
| 766 | int lookup_inline_extent_backref(struct btrfs_trans_handle *trans, |
| 767 | struct btrfs_path *path, |
| 768 | struct btrfs_extent_inline_ref **ref_ret, |
| 769 | u64 bytenr, u64 num_bytes, |
| 770 | u64 parent, u64 root_objectid, |
| 771 | u64 owner, u64 offset, int insert) |
| 772 | { |
| 773 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 774 | struct btrfs_root *root = btrfs_extent_root(fs_info, bytenr); |
| 775 | struct btrfs_key key; |
| 776 | struct extent_buffer *leaf; |
| 777 | struct btrfs_extent_item *ei; |
| 778 | struct btrfs_extent_inline_ref *iref; |
| 779 | u64 flags; |
| 780 | u64 item_size; |
| 781 | unsigned long ptr; |
| 782 | unsigned long end; |
| 783 | int extra_size; |
| 784 | int type; |
| 785 | int want; |
| 786 | int ret; |
| 787 | bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA); |
| 788 | int needed; |
| 789 | |
| 790 | key.objectid = bytenr; |
| 791 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 792 | key.offset = num_bytes; |
| 793 | |
| 794 | want = extent_ref_type(parent, owner); |
| 795 | if (insert) { |
| 796 | extra_size = btrfs_extent_inline_ref_size(want); |
| 797 | path->search_for_extension = 1; |
| 798 | path->keep_locks = 1; |
| 799 | } else |
| 800 | extra_size = -1; |
| 801 | |
| 802 | /* |
| 803 | * Owner is our level, so we can just add one to get the level for the |
| 804 | * block we are interested in. |
| 805 | */ |
| 806 | if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) { |
| 807 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 808 | key.offset = owner; |
| 809 | } |
| 810 | |
| 811 | again: |
| 812 | ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1); |
| 813 | if (ret < 0) |
| 814 | goto out; |
| 815 | |
| 816 | /* |
| 817 | * We may be a newly converted file system which still has the old fat |
| 818 | * extent entries for metadata, so try and see if we have one of those. |
| 819 | */ |
| 820 | if (ret > 0 && skinny_metadata) { |
| 821 | skinny_metadata = false; |
| 822 | if (path->slots[0]) { |
| 823 | path->slots[0]--; |
| 824 | btrfs_item_key_to_cpu(path->nodes[0], &key, |
| 825 | path->slots[0]); |
| 826 | if (key.objectid == bytenr && |
| 827 | key.type == BTRFS_EXTENT_ITEM_KEY && |
| 828 | key.offset == num_bytes) |
| 829 | ret = 0; |
| 830 | } |
| 831 | if (ret) { |
| 832 | key.objectid = bytenr; |
| 833 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 834 | key.offset = num_bytes; |
| 835 | btrfs_release_path(path); |
| 836 | goto again; |
| 837 | } |
| 838 | } |
| 839 | |
| 840 | if (ret && !insert) { |
| 841 | ret = -ENOENT; |
| 842 | goto out; |
| 843 | } else if (WARN_ON(ret)) { |
| 844 | btrfs_print_leaf(path->nodes[0]); |
| 845 | btrfs_err(fs_info, |
| 846 | "extent item not found for insert, bytenr %llu num_bytes %llu parent %llu root_objectid %llu owner %llu offset %llu", |
| 847 | bytenr, num_bytes, parent, root_objectid, owner, |
| 848 | offset); |
| 849 | ret = -EUCLEAN; |
| 850 | goto out; |
| 851 | } |
| 852 | |
| 853 | leaf = path->nodes[0]; |
| 854 | item_size = btrfs_item_size(leaf, path->slots[0]); |
| 855 | if (unlikely(item_size < sizeof(*ei))) { |
| 856 | ret = -EUCLEAN; |
| 857 | btrfs_err(fs_info, |
| 858 | "unexpected extent item size, has %llu expect >= %zu", |
| 859 | item_size, sizeof(*ei)); |
| 860 | btrfs_abort_transaction(trans, ret); |
| 861 | goto out; |
| 862 | } |
| 863 | |
| 864 | ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 865 | flags = btrfs_extent_flags(leaf, ei); |
| 866 | |
| 867 | ptr = (unsigned long)(ei + 1); |
| 868 | end = (unsigned long)ei + item_size; |
| 869 | |
| 870 | if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) { |
| 871 | ptr += sizeof(struct btrfs_tree_block_info); |
| 872 | BUG_ON(ptr > end); |
| 873 | } |
| 874 | |
| 875 | if (owner >= BTRFS_FIRST_FREE_OBJECTID) |
| 876 | needed = BTRFS_REF_TYPE_DATA; |
| 877 | else |
| 878 | needed = BTRFS_REF_TYPE_BLOCK; |
| 879 | |
| 880 | ret = -ENOENT; |
| 881 | while (ptr < end) { |
| 882 | iref = (struct btrfs_extent_inline_ref *)ptr; |
| 883 | type = btrfs_get_extent_inline_ref_type(leaf, iref, needed); |
| 884 | if (type == BTRFS_EXTENT_OWNER_REF_KEY) { |
| 885 | ASSERT(btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)); |
| 886 | ptr += btrfs_extent_inline_ref_size(type); |
| 887 | continue; |
| 888 | } |
| 889 | if (type == BTRFS_REF_TYPE_INVALID) { |
| 890 | ret = -EUCLEAN; |
| 891 | goto out; |
| 892 | } |
| 893 | |
| 894 | if (want < type) |
| 895 | break; |
| 896 | if (want > type) { |
| 897 | ptr += btrfs_extent_inline_ref_size(type); |
| 898 | continue; |
| 899 | } |
| 900 | |
| 901 | if (type == BTRFS_EXTENT_DATA_REF_KEY) { |
| 902 | struct btrfs_extent_data_ref *dref; |
| 903 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 904 | if (match_extent_data_ref(leaf, dref, root_objectid, |
| 905 | owner, offset)) { |
| 906 | ret = 0; |
| 907 | break; |
| 908 | } |
| 909 | if (hash_extent_data_ref_item(leaf, dref) < |
| 910 | hash_extent_data_ref(root_objectid, owner, offset)) |
| 911 | break; |
| 912 | } else { |
| 913 | u64 ref_offset; |
| 914 | ref_offset = btrfs_extent_inline_ref_offset(leaf, iref); |
| 915 | if (parent > 0) { |
| 916 | if (parent == ref_offset) { |
| 917 | ret = 0; |
| 918 | break; |
| 919 | } |
| 920 | if (ref_offset < parent) |
| 921 | break; |
| 922 | } else { |
| 923 | if (root_objectid == ref_offset) { |
| 924 | ret = 0; |
| 925 | break; |
| 926 | } |
| 927 | if (ref_offset < root_objectid) |
| 928 | break; |
| 929 | } |
| 930 | } |
| 931 | ptr += btrfs_extent_inline_ref_size(type); |
| 932 | } |
| 933 | |
| 934 | if (unlikely(ptr > end)) { |
| 935 | ret = -EUCLEAN; |
| 936 | btrfs_print_leaf(path->nodes[0]); |
| 937 | btrfs_crit(fs_info, |
| 938 | "overrun extent record at slot %d while looking for inline extent for root %llu owner %llu offset %llu parent %llu", |
| 939 | path->slots[0], root_objectid, owner, offset, parent); |
| 940 | goto out; |
| 941 | } |
| 942 | |
| 943 | if (ret == -ENOENT && insert) { |
| 944 | if (item_size + extra_size >= |
| 945 | BTRFS_MAX_EXTENT_ITEM_SIZE(root)) { |
| 946 | ret = -EAGAIN; |
| 947 | goto out; |
| 948 | } |
| 949 | /* |
| 950 | * To add new inline back ref, we have to make sure |
| 951 | * there is no corresponding back ref item. |
| 952 | * For simplicity, we just do not add new inline back |
| 953 | * ref if there is any kind of item for this block |
| 954 | */ |
| 955 | if (find_next_key(path, 0, &key) == 0 && |
| 956 | key.objectid == bytenr && |
| 957 | key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) { |
| 958 | ret = -EAGAIN; |
| 959 | goto out; |
| 960 | } |
| 961 | } |
| 962 | *ref_ret = (struct btrfs_extent_inline_ref *)ptr; |
| 963 | out: |
| 964 | if (insert) { |
| 965 | path->keep_locks = 0; |
| 966 | path->search_for_extension = 0; |
| 967 | btrfs_unlock_up_safe(path, 1); |
| 968 | } |
| 969 | return ret; |
| 970 | } |
| 971 | |
| 972 | /* |
| 973 | * helper to add new inline back ref |
| 974 | */ |
| 975 | static noinline_for_stack |
| 976 | void setup_inline_extent_backref(struct btrfs_trans_handle *trans, |
| 977 | struct btrfs_path *path, |
| 978 | struct btrfs_extent_inline_ref *iref, |
| 979 | u64 parent, u64 root_objectid, |
| 980 | u64 owner, u64 offset, int refs_to_add, |
| 981 | struct btrfs_delayed_extent_op *extent_op) |
| 982 | { |
| 983 | struct extent_buffer *leaf; |
| 984 | struct btrfs_extent_item *ei; |
| 985 | unsigned long ptr; |
| 986 | unsigned long end; |
| 987 | unsigned long item_offset; |
| 988 | u64 refs; |
| 989 | int size; |
| 990 | int type; |
| 991 | |
| 992 | leaf = path->nodes[0]; |
| 993 | ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 994 | item_offset = (unsigned long)iref - (unsigned long)ei; |
| 995 | |
| 996 | type = extent_ref_type(parent, owner); |
| 997 | size = btrfs_extent_inline_ref_size(type); |
| 998 | |
| 999 | btrfs_extend_item(trans, path, size); |
| 1000 | |
| 1001 | ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 1002 | refs = btrfs_extent_refs(leaf, ei); |
| 1003 | refs += refs_to_add; |
| 1004 | btrfs_set_extent_refs(leaf, ei, refs); |
| 1005 | if (extent_op) |
| 1006 | __run_delayed_extent_op(extent_op, leaf, ei); |
| 1007 | |
| 1008 | ptr = (unsigned long)ei + item_offset; |
| 1009 | end = (unsigned long)ei + btrfs_item_size(leaf, path->slots[0]); |
| 1010 | if (ptr < end - size) |
| 1011 | memmove_extent_buffer(leaf, ptr + size, ptr, |
| 1012 | end - size - ptr); |
| 1013 | |
| 1014 | iref = (struct btrfs_extent_inline_ref *)ptr; |
| 1015 | btrfs_set_extent_inline_ref_type(leaf, iref, type); |
| 1016 | if (type == BTRFS_EXTENT_DATA_REF_KEY) { |
| 1017 | struct btrfs_extent_data_ref *dref; |
| 1018 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 1019 | btrfs_set_extent_data_ref_root(leaf, dref, root_objectid); |
| 1020 | btrfs_set_extent_data_ref_objectid(leaf, dref, owner); |
| 1021 | btrfs_set_extent_data_ref_offset(leaf, dref, offset); |
| 1022 | btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add); |
| 1023 | } else if (type == BTRFS_SHARED_DATA_REF_KEY) { |
| 1024 | struct btrfs_shared_data_ref *sref; |
| 1025 | sref = (struct btrfs_shared_data_ref *)(iref + 1); |
| 1026 | btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add); |
| 1027 | btrfs_set_extent_inline_ref_offset(leaf, iref, parent); |
| 1028 | } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) { |
| 1029 | btrfs_set_extent_inline_ref_offset(leaf, iref, parent); |
| 1030 | } else { |
| 1031 | btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid); |
| 1032 | } |
| 1033 | btrfs_mark_buffer_dirty(trans, leaf); |
| 1034 | } |
| 1035 | |
| 1036 | static int lookup_extent_backref(struct btrfs_trans_handle *trans, |
| 1037 | struct btrfs_path *path, |
| 1038 | struct btrfs_extent_inline_ref **ref_ret, |
| 1039 | u64 bytenr, u64 num_bytes, u64 parent, |
| 1040 | u64 root_objectid, u64 owner, u64 offset) |
| 1041 | { |
| 1042 | int ret; |
| 1043 | |
| 1044 | ret = lookup_inline_extent_backref(trans, path, ref_ret, bytenr, |
| 1045 | num_bytes, parent, root_objectid, |
| 1046 | owner, offset, 0); |
| 1047 | if (ret != -ENOENT) |
| 1048 | return ret; |
| 1049 | |
| 1050 | btrfs_release_path(path); |
| 1051 | *ref_ret = NULL; |
| 1052 | |
| 1053 | if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| 1054 | ret = lookup_tree_block_ref(trans, path, bytenr, parent, |
| 1055 | root_objectid); |
| 1056 | } else { |
| 1057 | ret = lookup_extent_data_ref(trans, path, bytenr, parent, |
| 1058 | root_objectid, owner, offset); |
| 1059 | } |
| 1060 | return ret; |
| 1061 | } |
| 1062 | |
| 1063 | /* |
| 1064 | * helper to update/remove inline back ref |
| 1065 | */ |
| 1066 | static noinline_for_stack int update_inline_extent_backref( |
| 1067 | struct btrfs_trans_handle *trans, |
| 1068 | struct btrfs_path *path, |
| 1069 | struct btrfs_extent_inline_ref *iref, |
| 1070 | int refs_to_mod, |
| 1071 | struct btrfs_delayed_extent_op *extent_op) |
| 1072 | { |
| 1073 | struct extent_buffer *leaf = path->nodes[0]; |
| 1074 | struct btrfs_fs_info *fs_info = leaf->fs_info; |
| 1075 | struct btrfs_extent_item *ei; |
| 1076 | struct btrfs_extent_data_ref *dref = NULL; |
| 1077 | struct btrfs_shared_data_ref *sref = NULL; |
| 1078 | unsigned long ptr; |
| 1079 | unsigned long end; |
| 1080 | u32 item_size; |
| 1081 | int size; |
| 1082 | int type; |
| 1083 | u64 refs; |
| 1084 | |
| 1085 | ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 1086 | refs = btrfs_extent_refs(leaf, ei); |
| 1087 | if (unlikely(refs_to_mod < 0 && refs + refs_to_mod <= 0)) { |
| 1088 | struct btrfs_key key; |
| 1089 | u32 extent_size; |
| 1090 | |
| 1091 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 1092 | if (key.type == BTRFS_METADATA_ITEM_KEY) |
| 1093 | extent_size = fs_info->nodesize; |
| 1094 | else |
| 1095 | extent_size = key.offset; |
| 1096 | btrfs_print_leaf(leaf); |
| 1097 | btrfs_err(fs_info, |
| 1098 | "invalid refs_to_mod for extent %llu num_bytes %u, has %d expect >= -%llu", |
| 1099 | key.objectid, extent_size, refs_to_mod, refs); |
| 1100 | return -EUCLEAN; |
| 1101 | } |
| 1102 | refs += refs_to_mod; |
| 1103 | btrfs_set_extent_refs(leaf, ei, refs); |
| 1104 | if (extent_op) |
| 1105 | __run_delayed_extent_op(extent_op, leaf, ei); |
| 1106 | |
| 1107 | type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY); |
| 1108 | /* |
| 1109 | * Function btrfs_get_extent_inline_ref_type() has already printed |
| 1110 | * error messages. |
| 1111 | */ |
| 1112 | if (unlikely(type == BTRFS_REF_TYPE_INVALID)) |
| 1113 | return -EUCLEAN; |
| 1114 | |
| 1115 | if (type == BTRFS_EXTENT_DATA_REF_KEY) { |
| 1116 | dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 1117 | refs = btrfs_extent_data_ref_count(leaf, dref); |
| 1118 | } else if (type == BTRFS_SHARED_DATA_REF_KEY) { |
| 1119 | sref = (struct btrfs_shared_data_ref *)(iref + 1); |
| 1120 | refs = btrfs_shared_data_ref_count(leaf, sref); |
| 1121 | } else { |
| 1122 | refs = 1; |
| 1123 | /* |
| 1124 | * For tree blocks we can only drop one ref for it, and tree |
| 1125 | * blocks should not have refs > 1. |
| 1126 | * |
| 1127 | * Furthermore if we're inserting a new inline backref, we |
| 1128 | * won't reach this path either. That would be |
| 1129 | * setup_inline_extent_backref(). |
| 1130 | */ |
| 1131 | if (unlikely(refs_to_mod != -1)) { |
| 1132 | struct btrfs_key key; |
| 1133 | |
| 1134 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 1135 | |
| 1136 | btrfs_print_leaf(leaf); |
| 1137 | btrfs_err(fs_info, |
| 1138 | "invalid refs_to_mod for tree block %llu, has %d expect -1", |
| 1139 | key.objectid, refs_to_mod); |
| 1140 | return -EUCLEAN; |
| 1141 | } |
| 1142 | } |
| 1143 | |
| 1144 | if (unlikely(refs_to_mod < 0 && refs < -refs_to_mod)) { |
| 1145 | struct btrfs_key key; |
| 1146 | u32 extent_size; |
| 1147 | |
| 1148 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 1149 | if (key.type == BTRFS_METADATA_ITEM_KEY) |
| 1150 | extent_size = fs_info->nodesize; |
| 1151 | else |
| 1152 | extent_size = key.offset; |
| 1153 | btrfs_print_leaf(leaf); |
| 1154 | btrfs_err(fs_info, |
| 1155 | "invalid refs_to_mod for backref entry, iref %lu extent %llu num_bytes %u, has %d expect >= -%llu", |
| 1156 | (unsigned long)iref, key.objectid, extent_size, |
| 1157 | refs_to_mod, refs); |
| 1158 | return -EUCLEAN; |
| 1159 | } |
| 1160 | refs += refs_to_mod; |
| 1161 | |
| 1162 | if (refs > 0) { |
| 1163 | if (type == BTRFS_EXTENT_DATA_REF_KEY) |
| 1164 | btrfs_set_extent_data_ref_count(leaf, dref, refs); |
| 1165 | else |
| 1166 | btrfs_set_shared_data_ref_count(leaf, sref, refs); |
| 1167 | } else { |
| 1168 | size = btrfs_extent_inline_ref_size(type); |
| 1169 | item_size = btrfs_item_size(leaf, path->slots[0]); |
| 1170 | ptr = (unsigned long)iref; |
| 1171 | end = (unsigned long)ei + item_size; |
| 1172 | if (ptr + size < end) |
| 1173 | memmove_extent_buffer(leaf, ptr, ptr + size, |
| 1174 | end - ptr - size); |
| 1175 | item_size -= size; |
| 1176 | btrfs_truncate_item(trans, path, item_size, 1); |
| 1177 | } |
| 1178 | btrfs_mark_buffer_dirty(trans, leaf); |
| 1179 | return 0; |
| 1180 | } |
| 1181 | |
| 1182 | static noinline_for_stack |
| 1183 | int insert_inline_extent_backref(struct btrfs_trans_handle *trans, |
| 1184 | struct btrfs_path *path, |
| 1185 | u64 bytenr, u64 num_bytes, u64 parent, |
| 1186 | u64 root_objectid, u64 owner, |
| 1187 | u64 offset, int refs_to_add, |
| 1188 | struct btrfs_delayed_extent_op *extent_op) |
| 1189 | { |
| 1190 | struct btrfs_extent_inline_ref *iref; |
| 1191 | int ret; |
| 1192 | |
| 1193 | ret = lookup_inline_extent_backref(trans, path, &iref, bytenr, |
| 1194 | num_bytes, parent, root_objectid, |
| 1195 | owner, offset, 1); |
| 1196 | if (ret == 0) { |
| 1197 | /* |
| 1198 | * We're adding refs to a tree block we already own, this |
| 1199 | * should not happen at all. |
| 1200 | */ |
| 1201 | if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| 1202 | btrfs_print_leaf(path->nodes[0]); |
| 1203 | btrfs_crit(trans->fs_info, |
| 1204 | "adding refs to an existing tree ref, bytenr %llu num_bytes %llu root_objectid %llu slot %u", |
| 1205 | bytenr, num_bytes, root_objectid, path->slots[0]); |
| 1206 | return -EUCLEAN; |
| 1207 | } |
| 1208 | ret = update_inline_extent_backref(trans, path, iref, |
| 1209 | refs_to_add, extent_op); |
| 1210 | } else if (ret == -ENOENT) { |
| 1211 | setup_inline_extent_backref(trans, path, iref, parent, |
| 1212 | root_objectid, owner, offset, |
| 1213 | refs_to_add, extent_op); |
| 1214 | ret = 0; |
| 1215 | } |
| 1216 | return ret; |
| 1217 | } |
| 1218 | |
| 1219 | static int remove_extent_backref(struct btrfs_trans_handle *trans, |
| 1220 | struct btrfs_root *root, |
| 1221 | struct btrfs_path *path, |
| 1222 | struct btrfs_extent_inline_ref *iref, |
| 1223 | int refs_to_drop, int is_data) |
| 1224 | { |
| 1225 | int ret = 0; |
| 1226 | |
| 1227 | BUG_ON(!is_data && refs_to_drop != 1); |
| 1228 | if (iref) |
| 1229 | ret = update_inline_extent_backref(trans, path, iref, |
| 1230 | -refs_to_drop, NULL); |
| 1231 | else if (is_data) |
| 1232 | ret = remove_extent_data_ref(trans, root, path, refs_to_drop); |
| 1233 | else |
| 1234 | ret = btrfs_del_item(trans, root, path); |
| 1235 | return ret; |
| 1236 | } |
| 1237 | |
| 1238 | static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len, |
| 1239 | u64 *discarded_bytes) |
| 1240 | { |
| 1241 | int j, ret = 0; |
| 1242 | u64 bytes_left, end; |
| 1243 | u64 aligned_start = ALIGN(start, 1 << SECTOR_SHIFT); |
| 1244 | |
| 1245 | /* Adjust the range to be aligned to 512B sectors if necessary. */ |
| 1246 | if (start != aligned_start) { |
| 1247 | len -= aligned_start - start; |
| 1248 | len = round_down(len, 1 << SECTOR_SHIFT); |
| 1249 | start = aligned_start; |
| 1250 | } |
| 1251 | |
| 1252 | *discarded_bytes = 0; |
| 1253 | |
| 1254 | if (!len) |
| 1255 | return 0; |
| 1256 | |
| 1257 | end = start + len; |
| 1258 | bytes_left = len; |
| 1259 | |
| 1260 | /* Skip any superblocks on this device. */ |
| 1261 | for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) { |
| 1262 | u64 sb_start = btrfs_sb_offset(j); |
| 1263 | u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE; |
| 1264 | u64 size = sb_start - start; |
| 1265 | |
| 1266 | if (!in_range(sb_start, start, bytes_left) && |
| 1267 | !in_range(sb_end, start, bytes_left) && |
| 1268 | !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE)) |
| 1269 | continue; |
| 1270 | |
| 1271 | /* |
| 1272 | * Superblock spans beginning of range. Adjust start and |
| 1273 | * try again. |
| 1274 | */ |
| 1275 | if (sb_start <= start) { |
| 1276 | start += sb_end - start; |
| 1277 | if (start > end) { |
| 1278 | bytes_left = 0; |
| 1279 | break; |
| 1280 | } |
| 1281 | bytes_left = end - start; |
| 1282 | continue; |
| 1283 | } |
| 1284 | |
| 1285 | if (size) { |
| 1286 | ret = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, |
| 1287 | size >> SECTOR_SHIFT, |
| 1288 | GFP_NOFS); |
| 1289 | if (!ret) |
| 1290 | *discarded_bytes += size; |
| 1291 | else if (ret != -EOPNOTSUPP) |
| 1292 | return ret; |
| 1293 | } |
| 1294 | |
| 1295 | start = sb_end; |
| 1296 | if (start > end) { |
| 1297 | bytes_left = 0; |
| 1298 | break; |
| 1299 | } |
| 1300 | bytes_left = end - start; |
| 1301 | } |
| 1302 | |
| 1303 | if (bytes_left) { |
| 1304 | ret = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, |
| 1305 | bytes_left >> SECTOR_SHIFT, |
| 1306 | GFP_NOFS); |
| 1307 | if (!ret) |
| 1308 | *discarded_bytes += bytes_left; |
| 1309 | } |
| 1310 | return ret; |
| 1311 | } |
| 1312 | |
| 1313 | static int do_discard_extent(struct btrfs_discard_stripe *stripe, u64 *bytes) |
| 1314 | { |
| 1315 | struct btrfs_device *dev = stripe->dev; |
| 1316 | struct btrfs_fs_info *fs_info = dev->fs_info; |
| 1317 | struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; |
| 1318 | u64 phys = stripe->physical; |
| 1319 | u64 len = stripe->length; |
| 1320 | u64 discarded = 0; |
| 1321 | int ret = 0; |
| 1322 | |
| 1323 | /* Zone reset on a zoned filesystem */ |
| 1324 | if (btrfs_can_zone_reset(dev, phys, len)) { |
| 1325 | u64 src_disc; |
| 1326 | |
| 1327 | ret = btrfs_reset_device_zone(dev, phys, len, &discarded); |
| 1328 | if (ret) |
| 1329 | goto out; |
| 1330 | |
| 1331 | if (!btrfs_dev_replace_is_ongoing(dev_replace) || |
| 1332 | dev != dev_replace->srcdev) |
| 1333 | goto out; |
| 1334 | |
| 1335 | src_disc = discarded; |
| 1336 | |
| 1337 | /* Send to replace target as well */ |
| 1338 | ret = btrfs_reset_device_zone(dev_replace->tgtdev, phys, len, |
| 1339 | &discarded); |
| 1340 | discarded += src_disc; |
| 1341 | } else if (bdev_max_discard_sectors(stripe->dev->bdev)) { |
| 1342 | ret = btrfs_issue_discard(dev->bdev, phys, len, &discarded); |
| 1343 | } else { |
| 1344 | ret = 0; |
| 1345 | *bytes = 0; |
| 1346 | } |
| 1347 | |
| 1348 | out: |
| 1349 | *bytes = discarded; |
| 1350 | return ret; |
| 1351 | } |
| 1352 | |
| 1353 | int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr, |
| 1354 | u64 num_bytes, u64 *actual_bytes) |
| 1355 | { |
| 1356 | int ret = 0; |
| 1357 | u64 discarded_bytes = 0; |
| 1358 | u64 end = bytenr + num_bytes; |
| 1359 | u64 cur = bytenr; |
| 1360 | |
| 1361 | /* |
| 1362 | * Avoid races with device replace and make sure the devices in the |
| 1363 | * stripes don't go away while we are discarding. |
| 1364 | */ |
| 1365 | btrfs_bio_counter_inc_blocked(fs_info); |
| 1366 | while (cur < end) { |
| 1367 | struct btrfs_discard_stripe *stripes; |
| 1368 | unsigned int num_stripes; |
| 1369 | int i; |
| 1370 | |
| 1371 | num_bytes = end - cur; |
| 1372 | stripes = btrfs_map_discard(fs_info, cur, &num_bytes, &num_stripes); |
| 1373 | if (IS_ERR(stripes)) { |
| 1374 | ret = PTR_ERR(stripes); |
| 1375 | if (ret == -EOPNOTSUPP) |
| 1376 | ret = 0; |
| 1377 | break; |
| 1378 | } |
| 1379 | |
| 1380 | for (i = 0; i < num_stripes; i++) { |
| 1381 | struct btrfs_discard_stripe *stripe = stripes + i; |
| 1382 | u64 bytes; |
| 1383 | |
| 1384 | if (!stripe->dev->bdev) { |
| 1385 | ASSERT(btrfs_test_opt(fs_info, DEGRADED)); |
| 1386 | continue; |
| 1387 | } |
| 1388 | |
| 1389 | if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, |
| 1390 | &stripe->dev->dev_state)) |
| 1391 | continue; |
| 1392 | |
| 1393 | ret = do_discard_extent(stripe, &bytes); |
| 1394 | if (ret) { |
| 1395 | /* |
| 1396 | * Keep going if discard is not supported by the |
| 1397 | * device. |
| 1398 | */ |
| 1399 | if (ret != -EOPNOTSUPP) |
| 1400 | break; |
| 1401 | ret = 0; |
| 1402 | } else { |
| 1403 | discarded_bytes += bytes; |
| 1404 | } |
| 1405 | } |
| 1406 | kfree(stripes); |
| 1407 | if (ret) |
| 1408 | break; |
| 1409 | cur += num_bytes; |
| 1410 | } |
| 1411 | btrfs_bio_counter_dec(fs_info); |
| 1412 | if (actual_bytes) |
| 1413 | *actual_bytes = discarded_bytes; |
| 1414 | return ret; |
| 1415 | } |
| 1416 | |
| 1417 | /* Can return -ENOMEM */ |
| 1418 | int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
| 1419 | struct btrfs_ref *generic_ref) |
| 1420 | { |
| 1421 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 1422 | int ret; |
| 1423 | |
| 1424 | ASSERT(generic_ref->type != BTRFS_REF_NOT_SET && |
| 1425 | generic_ref->action); |
| 1426 | BUG_ON(generic_ref->type == BTRFS_REF_METADATA && |
| 1427 | generic_ref->ref_root == BTRFS_TREE_LOG_OBJECTID); |
| 1428 | |
| 1429 | if (generic_ref->type == BTRFS_REF_METADATA) |
| 1430 | ret = btrfs_add_delayed_tree_ref(trans, generic_ref, NULL); |
| 1431 | else |
| 1432 | ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0); |
| 1433 | |
| 1434 | btrfs_ref_tree_mod(fs_info, generic_ref); |
| 1435 | |
| 1436 | return ret; |
| 1437 | } |
| 1438 | |
| 1439 | /* |
| 1440 | * Insert backreference for a given extent. |
| 1441 | * |
| 1442 | * The counterpart is in __btrfs_free_extent(), with examples and more details |
| 1443 | * how it works. |
| 1444 | * |
| 1445 | * @trans: Handle of transaction |
| 1446 | * |
| 1447 | * @node: The delayed ref node used to get the bytenr/length for |
| 1448 | * extent whose references are incremented. |
| 1449 | * |
| 1450 | * @extent_op Pointer to a structure, holding information necessary when |
| 1451 | * updating a tree block's flags |
| 1452 | * |
| 1453 | */ |
| 1454 | static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
| 1455 | struct btrfs_delayed_ref_node *node, |
| 1456 | struct btrfs_delayed_extent_op *extent_op) |
| 1457 | { |
| 1458 | struct btrfs_path *path; |
| 1459 | struct extent_buffer *leaf; |
| 1460 | struct btrfs_extent_item *item; |
| 1461 | struct btrfs_key key; |
| 1462 | u64 bytenr = node->bytenr; |
| 1463 | u64 num_bytes = node->num_bytes; |
| 1464 | u64 owner = btrfs_delayed_ref_owner(node); |
| 1465 | u64 offset = btrfs_delayed_ref_offset(node); |
| 1466 | u64 refs; |
| 1467 | int refs_to_add = node->ref_mod; |
| 1468 | int ret; |
| 1469 | |
| 1470 | path = btrfs_alloc_path(); |
| 1471 | if (!path) |
| 1472 | return -ENOMEM; |
| 1473 | |
| 1474 | /* this will setup the path even if it fails to insert the back ref */ |
| 1475 | ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes, |
| 1476 | node->parent, node->ref_root, owner, |
| 1477 | offset, refs_to_add, extent_op); |
| 1478 | if ((ret < 0 && ret != -EAGAIN) || !ret) |
| 1479 | goto out; |
| 1480 | |
| 1481 | /* |
| 1482 | * Ok we had -EAGAIN which means we didn't have space to insert and |
| 1483 | * inline extent ref, so just update the reference count and add a |
| 1484 | * normal backref. |
| 1485 | */ |
| 1486 | leaf = path->nodes[0]; |
| 1487 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 1488 | item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 1489 | refs = btrfs_extent_refs(leaf, item); |
| 1490 | btrfs_set_extent_refs(leaf, item, refs + refs_to_add); |
| 1491 | if (extent_op) |
| 1492 | __run_delayed_extent_op(extent_op, leaf, item); |
| 1493 | |
| 1494 | btrfs_mark_buffer_dirty(trans, leaf); |
| 1495 | btrfs_release_path(path); |
| 1496 | |
| 1497 | /* now insert the actual backref */ |
| 1498 | if (owner < BTRFS_FIRST_FREE_OBJECTID) |
| 1499 | ret = insert_tree_block_ref(trans, path, node, bytenr); |
| 1500 | else |
| 1501 | ret = insert_extent_data_ref(trans, path, node, bytenr); |
| 1502 | |
| 1503 | if (ret) |
| 1504 | btrfs_abort_transaction(trans, ret); |
| 1505 | out: |
| 1506 | btrfs_free_path(path); |
| 1507 | return ret; |
| 1508 | } |
| 1509 | |
| 1510 | static void free_head_ref_squota_rsv(struct btrfs_fs_info *fs_info, |
| 1511 | struct btrfs_delayed_ref_head *href) |
| 1512 | { |
| 1513 | u64 root = href->owning_root; |
| 1514 | |
| 1515 | /* |
| 1516 | * Don't check must_insert_reserved, as this is called from contexts |
| 1517 | * where it has already been unset. |
| 1518 | */ |
| 1519 | if (btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_SIMPLE || |
| 1520 | !href->is_data || !is_fstree(root)) |
| 1521 | return; |
| 1522 | |
| 1523 | btrfs_qgroup_free_refroot(fs_info, root, href->reserved_bytes, |
| 1524 | BTRFS_QGROUP_RSV_DATA); |
| 1525 | } |
| 1526 | |
| 1527 | static int run_delayed_data_ref(struct btrfs_trans_handle *trans, |
| 1528 | struct btrfs_delayed_ref_head *href, |
| 1529 | struct btrfs_delayed_ref_node *node, |
| 1530 | struct btrfs_delayed_extent_op *extent_op, |
| 1531 | bool insert_reserved) |
| 1532 | { |
| 1533 | int ret = 0; |
| 1534 | u64 parent = 0; |
| 1535 | u64 flags = 0; |
| 1536 | |
| 1537 | trace_run_delayed_data_ref(trans->fs_info, node); |
| 1538 | |
| 1539 | if (node->type == BTRFS_SHARED_DATA_REF_KEY) |
| 1540 | parent = node->parent; |
| 1541 | |
| 1542 | if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { |
| 1543 | struct btrfs_key key; |
| 1544 | struct btrfs_squota_delta delta = { |
| 1545 | .root = href->owning_root, |
| 1546 | .num_bytes = node->num_bytes, |
| 1547 | .is_data = true, |
| 1548 | .is_inc = true, |
| 1549 | .generation = trans->transid, |
| 1550 | }; |
| 1551 | u64 owner = btrfs_delayed_ref_owner(node); |
| 1552 | u64 offset = btrfs_delayed_ref_offset(node); |
| 1553 | |
| 1554 | if (extent_op) |
| 1555 | flags |= extent_op->flags_to_set; |
| 1556 | |
| 1557 | key.objectid = node->bytenr; |
| 1558 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 1559 | key.offset = node->num_bytes; |
| 1560 | |
| 1561 | ret = alloc_reserved_file_extent(trans, parent, node->ref_root, |
| 1562 | flags, owner, offset, &key, |
| 1563 | node->ref_mod, |
| 1564 | href->owning_root); |
| 1565 | free_head_ref_squota_rsv(trans->fs_info, href); |
| 1566 | if (!ret) |
| 1567 | ret = btrfs_record_squota_delta(trans->fs_info, &delta); |
| 1568 | } else if (node->action == BTRFS_ADD_DELAYED_REF) { |
| 1569 | ret = __btrfs_inc_extent_ref(trans, node, extent_op); |
| 1570 | } else if (node->action == BTRFS_DROP_DELAYED_REF) { |
| 1571 | ret = __btrfs_free_extent(trans, href, node, extent_op); |
| 1572 | } else { |
| 1573 | BUG(); |
| 1574 | } |
| 1575 | return ret; |
| 1576 | } |
| 1577 | |
| 1578 | static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, |
| 1579 | struct extent_buffer *leaf, |
| 1580 | struct btrfs_extent_item *ei) |
| 1581 | { |
| 1582 | u64 flags = btrfs_extent_flags(leaf, ei); |
| 1583 | if (extent_op->update_flags) { |
| 1584 | flags |= extent_op->flags_to_set; |
| 1585 | btrfs_set_extent_flags(leaf, ei, flags); |
| 1586 | } |
| 1587 | |
| 1588 | if (extent_op->update_key) { |
| 1589 | struct btrfs_tree_block_info *bi; |
| 1590 | BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)); |
| 1591 | bi = (struct btrfs_tree_block_info *)(ei + 1); |
| 1592 | btrfs_set_tree_block_key(leaf, bi, &extent_op->key); |
| 1593 | } |
| 1594 | } |
| 1595 | |
| 1596 | static int run_delayed_extent_op(struct btrfs_trans_handle *trans, |
| 1597 | struct btrfs_delayed_ref_head *head, |
| 1598 | struct btrfs_delayed_extent_op *extent_op) |
| 1599 | { |
| 1600 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 1601 | struct btrfs_root *root; |
| 1602 | struct btrfs_key key; |
| 1603 | struct btrfs_path *path; |
| 1604 | struct btrfs_extent_item *ei; |
| 1605 | struct extent_buffer *leaf; |
| 1606 | u32 item_size; |
| 1607 | int ret; |
| 1608 | int metadata = 1; |
| 1609 | |
| 1610 | if (TRANS_ABORTED(trans)) |
| 1611 | return 0; |
| 1612 | |
| 1613 | if (!btrfs_fs_incompat(fs_info, SKINNY_METADATA)) |
| 1614 | metadata = 0; |
| 1615 | |
| 1616 | path = btrfs_alloc_path(); |
| 1617 | if (!path) |
| 1618 | return -ENOMEM; |
| 1619 | |
| 1620 | key.objectid = head->bytenr; |
| 1621 | |
| 1622 | if (metadata) { |
| 1623 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 1624 | key.offset = head->level; |
| 1625 | } else { |
| 1626 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 1627 | key.offset = head->num_bytes; |
| 1628 | } |
| 1629 | |
| 1630 | root = btrfs_extent_root(fs_info, key.objectid); |
| 1631 | again: |
| 1632 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); |
| 1633 | if (ret < 0) { |
| 1634 | goto out; |
| 1635 | } else if (ret > 0) { |
| 1636 | if (metadata) { |
| 1637 | if (path->slots[0] > 0) { |
| 1638 | path->slots[0]--; |
| 1639 | btrfs_item_key_to_cpu(path->nodes[0], &key, |
| 1640 | path->slots[0]); |
| 1641 | if (key.objectid == head->bytenr && |
| 1642 | key.type == BTRFS_EXTENT_ITEM_KEY && |
| 1643 | key.offset == head->num_bytes) |
| 1644 | ret = 0; |
| 1645 | } |
| 1646 | if (ret > 0) { |
| 1647 | btrfs_release_path(path); |
| 1648 | metadata = 0; |
| 1649 | |
| 1650 | key.objectid = head->bytenr; |
| 1651 | key.offset = head->num_bytes; |
| 1652 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 1653 | goto again; |
| 1654 | } |
| 1655 | } else { |
| 1656 | ret = -EUCLEAN; |
| 1657 | btrfs_err(fs_info, |
| 1658 | "missing extent item for extent %llu num_bytes %llu level %d", |
| 1659 | head->bytenr, head->num_bytes, head->level); |
| 1660 | goto out; |
| 1661 | } |
| 1662 | } |
| 1663 | |
| 1664 | leaf = path->nodes[0]; |
| 1665 | item_size = btrfs_item_size(leaf, path->slots[0]); |
| 1666 | |
| 1667 | if (unlikely(item_size < sizeof(*ei))) { |
| 1668 | ret = -EUCLEAN; |
| 1669 | btrfs_err(fs_info, |
| 1670 | "unexpected extent item size, has %u expect >= %zu", |
| 1671 | item_size, sizeof(*ei)); |
| 1672 | btrfs_abort_transaction(trans, ret); |
| 1673 | goto out; |
| 1674 | } |
| 1675 | |
| 1676 | ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 1677 | __run_delayed_extent_op(extent_op, leaf, ei); |
| 1678 | |
| 1679 | btrfs_mark_buffer_dirty(trans, leaf); |
| 1680 | out: |
| 1681 | btrfs_free_path(path); |
| 1682 | return ret; |
| 1683 | } |
| 1684 | |
| 1685 | static int run_delayed_tree_ref(struct btrfs_trans_handle *trans, |
| 1686 | struct btrfs_delayed_ref_head *href, |
| 1687 | struct btrfs_delayed_ref_node *node, |
| 1688 | struct btrfs_delayed_extent_op *extent_op, |
| 1689 | bool insert_reserved) |
| 1690 | { |
| 1691 | int ret = 0; |
| 1692 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 1693 | u64 parent = 0; |
| 1694 | u64 ref_root = 0; |
| 1695 | |
| 1696 | trace_run_delayed_tree_ref(trans->fs_info, node); |
| 1697 | |
| 1698 | if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) |
| 1699 | parent = node->parent; |
| 1700 | ref_root = node->ref_root; |
| 1701 | |
| 1702 | if (unlikely(node->ref_mod != 1)) { |
| 1703 | btrfs_err(trans->fs_info, |
| 1704 | "btree block %llu has %d references rather than 1: action %d ref_root %llu parent %llu", |
| 1705 | node->bytenr, node->ref_mod, node->action, ref_root, |
| 1706 | parent); |
| 1707 | return -EUCLEAN; |
| 1708 | } |
| 1709 | if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { |
| 1710 | struct btrfs_squota_delta delta = { |
| 1711 | .root = href->owning_root, |
| 1712 | .num_bytes = fs_info->nodesize, |
| 1713 | .is_data = false, |
| 1714 | .is_inc = true, |
| 1715 | .generation = trans->transid, |
| 1716 | }; |
| 1717 | |
| 1718 | ret = alloc_reserved_tree_block(trans, node, extent_op); |
| 1719 | if (!ret) |
| 1720 | btrfs_record_squota_delta(fs_info, &delta); |
| 1721 | } else if (node->action == BTRFS_ADD_DELAYED_REF) { |
| 1722 | ret = __btrfs_inc_extent_ref(trans, node, extent_op); |
| 1723 | } else if (node->action == BTRFS_DROP_DELAYED_REF) { |
| 1724 | ret = __btrfs_free_extent(trans, href, node, extent_op); |
| 1725 | } else { |
| 1726 | BUG(); |
| 1727 | } |
| 1728 | return ret; |
| 1729 | } |
| 1730 | |
| 1731 | /* helper function to actually process a single delayed ref entry */ |
| 1732 | static int run_one_delayed_ref(struct btrfs_trans_handle *trans, |
| 1733 | struct btrfs_delayed_ref_head *href, |
| 1734 | struct btrfs_delayed_ref_node *node, |
| 1735 | struct btrfs_delayed_extent_op *extent_op, |
| 1736 | bool insert_reserved) |
| 1737 | { |
| 1738 | int ret = 0; |
| 1739 | |
| 1740 | if (TRANS_ABORTED(trans)) { |
| 1741 | if (insert_reserved) { |
| 1742 | btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1); |
| 1743 | free_head_ref_squota_rsv(trans->fs_info, href); |
| 1744 | } |
| 1745 | return 0; |
| 1746 | } |
| 1747 | |
| 1748 | if (node->type == BTRFS_TREE_BLOCK_REF_KEY || |
| 1749 | node->type == BTRFS_SHARED_BLOCK_REF_KEY) |
| 1750 | ret = run_delayed_tree_ref(trans, href, node, extent_op, |
| 1751 | insert_reserved); |
| 1752 | else if (node->type == BTRFS_EXTENT_DATA_REF_KEY || |
| 1753 | node->type == BTRFS_SHARED_DATA_REF_KEY) |
| 1754 | ret = run_delayed_data_ref(trans, href, node, extent_op, |
| 1755 | insert_reserved); |
| 1756 | else if (node->type == BTRFS_EXTENT_OWNER_REF_KEY) |
| 1757 | ret = 0; |
| 1758 | else |
| 1759 | BUG(); |
| 1760 | if (ret && insert_reserved) |
| 1761 | btrfs_pin_extent(trans, node->bytenr, node->num_bytes, 1); |
| 1762 | if (ret < 0) |
| 1763 | btrfs_err(trans->fs_info, |
| 1764 | "failed to run delayed ref for logical %llu num_bytes %llu type %u action %u ref_mod %d: %d", |
| 1765 | node->bytenr, node->num_bytes, node->type, |
| 1766 | node->action, node->ref_mod, ret); |
| 1767 | return ret; |
| 1768 | } |
| 1769 | |
| 1770 | static inline struct btrfs_delayed_ref_node * |
| 1771 | select_delayed_ref(struct btrfs_delayed_ref_head *head) |
| 1772 | { |
| 1773 | struct btrfs_delayed_ref_node *ref; |
| 1774 | |
| 1775 | if (RB_EMPTY_ROOT(&head->ref_tree.rb_root)) |
| 1776 | return NULL; |
| 1777 | |
| 1778 | /* |
| 1779 | * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first. |
| 1780 | * This is to prevent a ref count from going down to zero, which deletes |
| 1781 | * the extent item from the extent tree, when there still are references |
| 1782 | * to add, which would fail because they would not find the extent item. |
| 1783 | */ |
| 1784 | if (!list_empty(&head->ref_add_list)) |
| 1785 | return list_first_entry(&head->ref_add_list, |
| 1786 | struct btrfs_delayed_ref_node, add_list); |
| 1787 | |
| 1788 | ref = rb_entry(rb_first_cached(&head->ref_tree), |
| 1789 | struct btrfs_delayed_ref_node, ref_node); |
| 1790 | ASSERT(list_empty(&ref->add_list)); |
| 1791 | return ref; |
| 1792 | } |
| 1793 | |
| 1794 | static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, |
| 1795 | struct btrfs_delayed_ref_head *head) |
| 1796 | { |
| 1797 | spin_lock(&delayed_refs->lock); |
| 1798 | head->processing = false; |
| 1799 | delayed_refs->num_heads_ready++; |
| 1800 | spin_unlock(&delayed_refs->lock); |
| 1801 | btrfs_delayed_ref_unlock(head); |
| 1802 | } |
| 1803 | |
| 1804 | static struct btrfs_delayed_extent_op *cleanup_extent_op( |
| 1805 | struct btrfs_delayed_ref_head *head) |
| 1806 | { |
| 1807 | struct btrfs_delayed_extent_op *extent_op = head->extent_op; |
| 1808 | |
| 1809 | if (!extent_op) |
| 1810 | return NULL; |
| 1811 | |
| 1812 | if (head->must_insert_reserved) { |
| 1813 | head->extent_op = NULL; |
| 1814 | btrfs_free_delayed_extent_op(extent_op); |
| 1815 | return NULL; |
| 1816 | } |
| 1817 | return extent_op; |
| 1818 | } |
| 1819 | |
| 1820 | static int run_and_cleanup_extent_op(struct btrfs_trans_handle *trans, |
| 1821 | struct btrfs_delayed_ref_head *head) |
| 1822 | { |
| 1823 | struct btrfs_delayed_extent_op *extent_op; |
| 1824 | int ret; |
| 1825 | |
| 1826 | extent_op = cleanup_extent_op(head); |
| 1827 | if (!extent_op) |
| 1828 | return 0; |
| 1829 | head->extent_op = NULL; |
| 1830 | spin_unlock(&head->lock); |
| 1831 | ret = run_delayed_extent_op(trans, head, extent_op); |
| 1832 | btrfs_free_delayed_extent_op(extent_op); |
| 1833 | return ret ? ret : 1; |
| 1834 | } |
| 1835 | |
| 1836 | u64 btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info, |
| 1837 | struct btrfs_delayed_ref_root *delayed_refs, |
| 1838 | struct btrfs_delayed_ref_head *head) |
| 1839 | { |
| 1840 | u64 ret = 0; |
| 1841 | |
| 1842 | /* |
| 1843 | * We had csum deletions accounted for in our delayed refs rsv, we need |
| 1844 | * to drop the csum leaves for this update from our delayed_refs_rsv. |
| 1845 | */ |
| 1846 | if (head->total_ref_mod < 0 && head->is_data) { |
| 1847 | int nr_csums; |
| 1848 | |
| 1849 | spin_lock(&delayed_refs->lock); |
| 1850 | delayed_refs->pending_csums -= head->num_bytes; |
| 1851 | spin_unlock(&delayed_refs->lock); |
| 1852 | nr_csums = btrfs_csum_bytes_to_leaves(fs_info, head->num_bytes); |
| 1853 | |
| 1854 | btrfs_delayed_refs_rsv_release(fs_info, 0, nr_csums); |
| 1855 | |
| 1856 | ret = btrfs_calc_delayed_ref_csum_bytes(fs_info, nr_csums); |
| 1857 | } |
| 1858 | /* must_insert_reserved can be set only if we didn't run the head ref. */ |
| 1859 | if (head->must_insert_reserved) |
| 1860 | free_head_ref_squota_rsv(fs_info, head); |
| 1861 | |
| 1862 | return ret; |
| 1863 | } |
| 1864 | |
| 1865 | static int cleanup_ref_head(struct btrfs_trans_handle *trans, |
| 1866 | struct btrfs_delayed_ref_head *head, |
| 1867 | u64 *bytes_released) |
| 1868 | { |
| 1869 | |
| 1870 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 1871 | struct btrfs_delayed_ref_root *delayed_refs; |
| 1872 | int ret; |
| 1873 | |
| 1874 | delayed_refs = &trans->transaction->delayed_refs; |
| 1875 | |
| 1876 | ret = run_and_cleanup_extent_op(trans, head); |
| 1877 | if (ret < 0) { |
| 1878 | unselect_delayed_ref_head(delayed_refs, head); |
| 1879 | btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); |
| 1880 | return ret; |
| 1881 | } else if (ret) { |
| 1882 | return ret; |
| 1883 | } |
| 1884 | |
| 1885 | /* |
| 1886 | * Need to drop our head ref lock and re-acquire the delayed ref lock |
| 1887 | * and then re-check to make sure nobody got added. |
| 1888 | */ |
| 1889 | spin_unlock(&head->lock); |
| 1890 | spin_lock(&delayed_refs->lock); |
| 1891 | spin_lock(&head->lock); |
| 1892 | if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root) || head->extent_op) { |
| 1893 | spin_unlock(&head->lock); |
| 1894 | spin_unlock(&delayed_refs->lock); |
| 1895 | return 1; |
| 1896 | } |
| 1897 | btrfs_delete_ref_head(delayed_refs, head); |
| 1898 | spin_unlock(&head->lock); |
| 1899 | spin_unlock(&delayed_refs->lock); |
| 1900 | |
| 1901 | if (head->must_insert_reserved) { |
| 1902 | btrfs_pin_extent(trans, head->bytenr, head->num_bytes, 1); |
| 1903 | if (head->is_data) { |
| 1904 | struct btrfs_root *csum_root; |
| 1905 | |
| 1906 | csum_root = btrfs_csum_root(fs_info, head->bytenr); |
| 1907 | ret = btrfs_del_csums(trans, csum_root, head->bytenr, |
| 1908 | head->num_bytes); |
| 1909 | } |
| 1910 | } |
| 1911 | |
| 1912 | *bytes_released += btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head); |
| 1913 | |
| 1914 | trace_run_delayed_ref_head(fs_info, head, 0); |
| 1915 | btrfs_delayed_ref_unlock(head); |
| 1916 | btrfs_put_delayed_ref_head(head); |
| 1917 | return ret; |
| 1918 | } |
| 1919 | |
| 1920 | static struct btrfs_delayed_ref_head *btrfs_obtain_ref_head( |
| 1921 | struct btrfs_trans_handle *trans) |
| 1922 | { |
| 1923 | struct btrfs_delayed_ref_root *delayed_refs = |
| 1924 | &trans->transaction->delayed_refs; |
| 1925 | struct btrfs_delayed_ref_head *head = NULL; |
| 1926 | int ret; |
| 1927 | |
| 1928 | spin_lock(&delayed_refs->lock); |
| 1929 | head = btrfs_select_ref_head(delayed_refs); |
| 1930 | if (!head) { |
| 1931 | spin_unlock(&delayed_refs->lock); |
| 1932 | return head; |
| 1933 | } |
| 1934 | |
| 1935 | /* |
| 1936 | * Grab the lock that says we are going to process all the refs for |
| 1937 | * this head |
| 1938 | */ |
| 1939 | ret = btrfs_delayed_ref_lock(delayed_refs, head); |
| 1940 | spin_unlock(&delayed_refs->lock); |
| 1941 | |
| 1942 | /* |
| 1943 | * We may have dropped the spin lock to get the head mutex lock, and |
| 1944 | * that might have given someone else time to free the head. If that's |
| 1945 | * true, it has been removed from our list and we can move on. |
| 1946 | */ |
| 1947 | if (ret == -EAGAIN) |
| 1948 | head = ERR_PTR(-EAGAIN); |
| 1949 | |
| 1950 | return head; |
| 1951 | } |
| 1952 | |
| 1953 | static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans, |
| 1954 | struct btrfs_delayed_ref_head *locked_ref, |
| 1955 | u64 *bytes_released) |
| 1956 | { |
| 1957 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 1958 | struct btrfs_delayed_ref_root *delayed_refs; |
| 1959 | struct btrfs_delayed_extent_op *extent_op; |
| 1960 | struct btrfs_delayed_ref_node *ref; |
| 1961 | bool must_insert_reserved; |
| 1962 | int ret; |
| 1963 | |
| 1964 | delayed_refs = &trans->transaction->delayed_refs; |
| 1965 | |
| 1966 | lockdep_assert_held(&locked_ref->mutex); |
| 1967 | lockdep_assert_held(&locked_ref->lock); |
| 1968 | |
| 1969 | while ((ref = select_delayed_ref(locked_ref))) { |
| 1970 | if (ref->seq && |
| 1971 | btrfs_check_delayed_seq(fs_info, ref->seq)) { |
| 1972 | spin_unlock(&locked_ref->lock); |
| 1973 | unselect_delayed_ref_head(delayed_refs, locked_ref); |
| 1974 | return -EAGAIN; |
| 1975 | } |
| 1976 | |
| 1977 | rb_erase_cached(&ref->ref_node, &locked_ref->ref_tree); |
| 1978 | RB_CLEAR_NODE(&ref->ref_node); |
| 1979 | if (!list_empty(&ref->add_list)) |
| 1980 | list_del(&ref->add_list); |
| 1981 | /* |
| 1982 | * When we play the delayed ref, also correct the ref_mod on |
| 1983 | * head |
| 1984 | */ |
| 1985 | switch (ref->action) { |
| 1986 | case BTRFS_ADD_DELAYED_REF: |
| 1987 | case BTRFS_ADD_DELAYED_EXTENT: |
| 1988 | locked_ref->ref_mod -= ref->ref_mod; |
| 1989 | break; |
| 1990 | case BTRFS_DROP_DELAYED_REF: |
| 1991 | locked_ref->ref_mod += ref->ref_mod; |
| 1992 | break; |
| 1993 | default: |
| 1994 | WARN_ON(1); |
| 1995 | } |
| 1996 | atomic_dec(&delayed_refs->num_entries); |
| 1997 | |
| 1998 | /* |
| 1999 | * Record the must_insert_reserved flag before we drop the |
| 2000 | * spin lock. |
| 2001 | */ |
| 2002 | must_insert_reserved = locked_ref->must_insert_reserved; |
| 2003 | /* |
| 2004 | * Unsetting this on the head ref relinquishes ownership of |
| 2005 | * the rsv_bytes, so it is critical that every possible code |
| 2006 | * path from here forward frees all reserves including qgroup |
| 2007 | * reserve. |
| 2008 | */ |
| 2009 | locked_ref->must_insert_reserved = false; |
| 2010 | |
| 2011 | extent_op = locked_ref->extent_op; |
| 2012 | locked_ref->extent_op = NULL; |
| 2013 | spin_unlock(&locked_ref->lock); |
| 2014 | |
| 2015 | ret = run_one_delayed_ref(trans, locked_ref, ref, extent_op, |
| 2016 | must_insert_reserved); |
| 2017 | btrfs_delayed_refs_rsv_release(fs_info, 1, 0); |
| 2018 | *bytes_released += btrfs_calc_delayed_ref_bytes(fs_info, 1); |
| 2019 | |
| 2020 | btrfs_free_delayed_extent_op(extent_op); |
| 2021 | if (ret) { |
| 2022 | unselect_delayed_ref_head(delayed_refs, locked_ref); |
| 2023 | btrfs_put_delayed_ref(ref); |
| 2024 | return ret; |
| 2025 | } |
| 2026 | |
| 2027 | btrfs_put_delayed_ref(ref); |
| 2028 | cond_resched(); |
| 2029 | |
| 2030 | spin_lock(&locked_ref->lock); |
| 2031 | btrfs_merge_delayed_refs(fs_info, delayed_refs, locked_ref); |
| 2032 | } |
| 2033 | |
| 2034 | return 0; |
| 2035 | } |
| 2036 | |
| 2037 | /* |
| 2038 | * Returns 0 on success or if called with an already aborted transaction. |
| 2039 | * Returns -ENOMEM or -EIO on failure and will abort the transaction. |
| 2040 | */ |
| 2041 | static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, |
| 2042 | u64 min_bytes) |
| 2043 | { |
| 2044 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 2045 | struct btrfs_delayed_ref_root *delayed_refs; |
| 2046 | struct btrfs_delayed_ref_head *locked_ref = NULL; |
| 2047 | int ret; |
| 2048 | unsigned long count = 0; |
| 2049 | unsigned long max_count = 0; |
| 2050 | u64 bytes_processed = 0; |
| 2051 | |
| 2052 | delayed_refs = &trans->transaction->delayed_refs; |
| 2053 | if (min_bytes == 0) { |
| 2054 | max_count = delayed_refs->num_heads_ready; |
| 2055 | min_bytes = U64_MAX; |
| 2056 | } |
| 2057 | |
| 2058 | do { |
| 2059 | if (!locked_ref) { |
| 2060 | locked_ref = btrfs_obtain_ref_head(trans); |
| 2061 | if (IS_ERR_OR_NULL(locked_ref)) { |
| 2062 | if (PTR_ERR(locked_ref) == -EAGAIN) { |
| 2063 | continue; |
| 2064 | } else { |
| 2065 | break; |
| 2066 | } |
| 2067 | } |
| 2068 | count++; |
| 2069 | } |
| 2070 | /* |
| 2071 | * We need to try and merge add/drops of the same ref since we |
| 2072 | * can run into issues with relocate dropping the implicit ref |
| 2073 | * and then it being added back again before the drop can |
| 2074 | * finish. If we merged anything we need to re-loop so we can |
| 2075 | * get a good ref. |
| 2076 | * Or we can get node references of the same type that weren't |
| 2077 | * merged when created due to bumps in the tree mod seq, and |
| 2078 | * we need to merge them to prevent adding an inline extent |
| 2079 | * backref before dropping it (triggering a BUG_ON at |
| 2080 | * insert_inline_extent_backref()). |
| 2081 | */ |
| 2082 | spin_lock(&locked_ref->lock); |
| 2083 | btrfs_merge_delayed_refs(fs_info, delayed_refs, locked_ref); |
| 2084 | |
| 2085 | ret = btrfs_run_delayed_refs_for_head(trans, locked_ref, &bytes_processed); |
| 2086 | if (ret < 0 && ret != -EAGAIN) { |
| 2087 | /* |
| 2088 | * Error, btrfs_run_delayed_refs_for_head already |
| 2089 | * unlocked everything so just bail out |
| 2090 | */ |
| 2091 | return ret; |
| 2092 | } else if (!ret) { |
| 2093 | /* |
| 2094 | * Success, perform the usual cleanup of a processed |
| 2095 | * head |
| 2096 | */ |
| 2097 | ret = cleanup_ref_head(trans, locked_ref, &bytes_processed); |
| 2098 | if (ret > 0 ) { |
| 2099 | /* We dropped our lock, we need to loop. */ |
| 2100 | ret = 0; |
| 2101 | continue; |
| 2102 | } else if (ret) { |
| 2103 | return ret; |
| 2104 | } |
| 2105 | } |
| 2106 | |
| 2107 | /* |
| 2108 | * Either success case or btrfs_run_delayed_refs_for_head |
| 2109 | * returned -EAGAIN, meaning we need to select another head |
| 2110 | */ |
| 2111 | |
| 2112 | locked_ref = NULL; |
| 2113 | cond_resched(); |
| 2114 | } while ((min_bytes != U64_MAX && bytes_processed < min_bytes) || |
| 2115 | (max_count > 0 && count < max_count) || |
| 2116 | locked_ref); |
| 2117 | |
| 2118 | return 0; |
| 2119 | } |
| 2120 | |
| 2121 | #ifdef SCRAMBLE_DELAYED_REFS |
| 2122 | /* |
| 2123 | * Normally delayed refs get processed in ascending bytenr order. This |
| 2124 | * correlates in most cases to the order added. To expose dependencies on this |
| 2125 | * order, we start to process the tree in the middle instead of the beginning |
| 2126 | */ |
| 2127 | static u64 find_middle(struct rb_root *root) |
| 2128 | { |
| 2129 | struct rb_node *n = root->rb_node; |
| 2130 | struct btrfs_delayed_ref_node *entry; |
| 2131 | int alt = 1; |
| 2132 | u64 middle; |
| 2133 | u64 first = 0, last = 0; |
| 2134 | |
| 2135 | n = rb_first(root); |
| 2136 | if (n) { |
| 2137 | entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); |
| 2138 | first = entry->bytenr; |
| 2139 | } |
| 2140 | n = rb_last(root); |
| 2141 | if (n) { |
| 2142 | entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); |
| 2143 | last = entry->bytenr; |
| 2144 | } |
| 2145 | n = root->rb_node; |
| 2146 | |
| 2147 | while (n) { |
| 2148 | entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); |
| 2149 | WARN_ON(!entry->in_tree); |
| 2150 | |
| 2151 | middle = entry->bytenr; |
| 2152 | |
| 2153 | if (alt) |
| 2154 | n = n->rb_left; |
| 2155 | else |
| 2156 | n = n->rb_right; |
| 2157 | |
| 2158 | alt = 1 - alt; |
| 2159 | } |
| 2160 | return middle; |
| 2161 | } |
| 2162 | #endif |
| 2163 | |
| 2164 | /* |
| 2165 | * Start processing the delayed reference count updates and extent insertions |
| 2166 | * we have queued up so far. |
| 2167 | * |
| 2168 | * @trans: Transaction handle. |
| 2169 | * @min_bytes: How many bytes of delayed references to process. After this |
| 2170 | * many bytes we stop processing delayed references if there are |
| 2171 | * any more. If 0 it means to run all existing delayed references, |
| 2172 | * but not new ones added after running all existing ones. |
| 2173 | * Use (u64)-1 (U64_MAX) to run all existing delayed references |
| 2174 | * plus any new ones that are added. |
| 2175 | * |
| 2176 | * Returns 0 on success or if called with an aborted transaction |
| 2177 | * Returns <0 on error and aborts the transaction |
| 2178 | */ |
| 2179 | int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, u64 min_bytes) |
| 2180 | { |
| 2181 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 2182 | struct btrfs_delayed_ref_root *delayed_refs; |
| 2183 | int ret; |
| 2184 | |
| 2185 | /* We'll clean this up in btrfs_cleanup_transaction */ |
| 2186 | if (TRANS_ABORTED(trans)) |
| 2187 | return 0; |
| 2188 | |
| 2189 | if (test_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags)) |
| 2190 | return 0; |
| 2191 | |
| 2192 | delayed_refs = &trans->transaction->delayed_refs; |
| 2193 | again: |
| 2194 | #ifdef SCRAMBLE_DELAYED_REFS |
| 2195 | delayed_refs->run_delayed_start = find_middle(&delayed_refs->root); |
| 2196 | #endif |
| 2197 | ret = __btrfs_run_delayed_refs(trans, min_bytes); |
| 2198 | if (ret < 0) { |
| 2199 | btrfs_abort_transaction(trans, ret); |
| 2200 | return ret; |
| 2201 | } |
| 2202 | |
| 2203 | if (min_bytes == U64_MAX) { |
| 2204 | btrfs_create_pending_block_groups(trans); |
| 2205 | |
| 2206 | spin_lock(&delayed_refs->lock); |
| 2207 | if (RB_EMPTY_ROOT(&delayed_refs->href_root.rb_root)) { |
| 2208 | spin_unlock(&delayed_refs->lock); |
| 2209 | return 0; |
| 2210 | } |
| 2211 | spin_unlock(&delayed_refs->lock); |
| 2212 | |
| 2213 | cond_resched(); |
| 2214 | goto again; |
| 2215 | } |
| 2216 | |
| 2217 | return 0; |
| 2218 | } |
| 2219 | |
| 2220 | int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans, |
| 2221 | struct extent_buffer *eb, u64 flags) |
| 2222 | { |
| 2223 | struct btrfs_delayed_extent_op *extent_op; |
| 2224 | int ret; |
| 2225 | |
| 2226 | extent_op = btrfs_alloc_delayed_extent_op(); |
| 2227 | if (!extent_op) |
| 2228 | return -ENOMEM; |
| 2229 | |
| 2230 | extent_op->flags_to_set = flags; |
| 2231 | extent_op->update_flags = true; |
| 2232 | extent_op->update_key = false; |
| 2233 | |
| 2234 | ret = btrfs_add_delayed_extent_op(trans, eb->start, eb->len, |
| 2235 | btrfs_header_level(eb), extent_op); |
| 2236 | if (ret) |
| 2237 | btrfs_free_delayed_extent_op(extent_op); |
| 2238 | return ret; |
| 2239 | } |
| 2240 | |
| 2241 | static noinline int check_delayed_ref(struct btrfs_root *root, |
| 2242 | struct btrfs_path *path, |
| 2243 | u64 objectid, u64 offset, u64 bytenr) |
| 2244 | { |
| 2245 | struct btrfs_delayed_ref_head *head; |
| 2246 | struct btrfs_delayed_ref_node *ref; |
| 2247 | struct btrfs_delayed_ref_root *delayed_refs; |
| 2248 | struct btrfs_transaction *cur_trans; |
| 2249 | struct rb_node *node; |
| 2250 | int ret = 0; |
| 2251 | |
| 2252 | spin_lock(&root->fs_info->trans_lock); |
| 2253 | cur_trans = root->fs_info->running_transaction; |
| 2254 | if (cur_trans) |
| 2255 | refcount_inc(&cur_trans->use_count); |
| 2256 | spin_unlock(&root->fs_info->trans_lock); |
| 2257 | if (!cur_trans) |
| 2258 | return 0; |
| 2259 | |
| 2260 | delayed_refs = &cur_trans->delayed_refs; |
| 2261 | spin_lock(&delayed_refs->lock); |
| 2262 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
| 2263 | if (!head) { |
| 2264 | spin_unlock(&delayed_refs->lock); |
| 2265 | btrfs_put_transaction(cur_trans); |
| 2266 | return 0; |
| 2267 | } |
| 2268 | |
| 2269 | if (!mutex_trylock(&head->mutex)) { |
| 2270 | if (path->nowait) { |
| 2271 | spin_unlock(&delayed_refs->lock); |
| 2272 | btrfs_put_transaction(cur_trans); |
| 2273 | return -EAGAIN; |
| 2274 | } |
| 2275 | |
| 2276 | refcount_inc(&head->refs); |
| 2277 | spin_unlock(&delayed_refs->lock); |
| 2278 | |
| 2279 | btrfs_release_path(path); |
| 2280 | |
| 2281 | /* |
| 2282 | * Mutex was contended, block until it's released and let |
| 2283 | * caller try again |
| 2284 | */ |
| 2285 | mutex_lock(&head->mutex); |
| 2286 | mutex_unlock(&head->mutex); |
| 2287 | btrfs_put_delayed_ref_head(head); |
| 2288 | btrfs_put_transaction(cur_trans); |
| 2289 | return -EAGAIN; |
| 2290 | } |
| 2291 | spin_unlock(&delayed_refs->lock); |
| 2292 | |
| 2293 | spin_lock(&head->lock); |
| 2294 | /* |
| 2295 | * XXX: We should replace this with a proper search function in the |
| 2296 | * future. |
| 2297 | */ |
| 2298 | for (node = rb_first_cached(&head->ref_tree); node; |
| 2299 | node = rb_next(node)) { |
| 2300 | u64 ref_owner; |
| 2301 | u64 ref_offset; |
| 2302 | |
| 2303 | ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node); |
| 2304 | /* If it's a shared ref we know a cross reference exists */ |
| 2305 | if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) { |
| 2306 | ret = 1; |
| 2307 | break; |
| 2308 | } |
| 2309 | |
| 2310 | ref_owner = btrfs_delayed_ref_owner(ref); |
| 2311 | ref_offset = btrfs_delayed_ref_offset(ref); |
| 2312 | |
| 2313 | /* |
| 2314 | * If our ref doesn't match the one we're currently looking at |
| 2315 | * then we have a cross reference. |
| 2316 | */ |
| 2317 | if (ref->ref_root != btrfs_root_id(root) || |
| 2318 | ref_owner != objectid || ref_offset != offset) { |
| 2319 | ret = 1; |
| 2320 | break; |
| 2321 | } |
| 2322 | } |
| 2323 | spin_unlock(&head->lock); |
| 2324 | mutex_unlock(&head->mutex); |
| 2325 | btrfs_put_transaction(cur_trans); |
| 2326 | return ret; |
| 2327 | } |
| 2328 | |
| 2329 | static noinline int check_committed_ref(struct btrfs_root *root, |
| 2330 | struct btrfs_path *path, |
| 2331 | u64 objectid, u64 offset, u64 bytenr, |
| 2332 | bool strict) |
| 2333 | { |
| 2334 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 2335 | struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bytenr); |
| 2336 | struct extent_buffer *leaf; |
| 2337 | struct btrfs_extent_data_ref *ref; |
| 2338 | struct btrfs_extent_inline_ref *iref; |
| 2339 | struct btrfs_extent_item *ei; |
| 2340 | struct btrfs_key key; |
| 2341 | u32 item_size; |
| 2342 | u32 expected_size; |
| 2343 | int type; |
| 2344 | int ret; |
| 2345 | |
| 2346 | key.objectid = bytenr; |
| 2347 | key.offset = (u64)-1; |
| 2348 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 2349 | |
| 2350 | ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| 2351 | if (ret < 0) |
| 2352 | goto out; |
| 2353 | if (ret == 0) { |
| 2354 | /* |
| 2355 | * Key with offset -1 found, there would have to exist an extent |
| 2356 | * item with such offset, but this is out of the valid range. |
| 2357 | */ |
| 2358 | ret = -EUCLEAN; |
| 2359 | goto out; |
| 2360 | } |
| 2361 | |
| 2362 | ret = -ENOENT; |
| 2363 | if (path->slots[0] == 0) |
| 2364 | goto out; |
| 2365 | |
| 2366 | path->slots[0]--; |
| 2367 | leaf = path->nodes[0]; |
| 2368 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 2369 | |
| 2370 | if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY) |
| 2371 | goto out; |
| 2372 | |
| 2373 | ret = 1; |
| 2374 | item_size = btrfs_item_size(leaf, path->slots[0]); |
| 2375 | ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| 2376 | expected_size = sizeof(*ei) + btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY); |
| 2377 | |
| 2378 | /* No inline refs; we need to bail before checking for owner ref. */ |
| 2379 | if (item_size == sizeof(*ei)) |
| 2380 | goto out; |
| 2381 | |
| 2382 | /* Check for an owner ref; skip over it to the real inline refs. */ |
| 2383 | iref = (struct btrfs_extent_inline_ref *)(ei + 1); |
| 2384 | type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA); |
| 2385 | if (btrfs_fs_incompat(fs_info, SIMPLE_QUOTA) && type == BTRFS_EXTENT_OWNER_REF_KEY) { |
| 2386 | expected_size += btrfs_extent_inline_ref_size(BTRFS_EXTENT_OWNER_REF_KEY); |
| 2387 | iref = (struct btrfs_extent_inline_ref *)(iref + 1); |
| 2388 | } |
| 2389 | |
| 2390 | /* If extent item has more than 1 inline ref then it's shared */ |
| 2391 | if (item_size != expected_size) |
| 2392 | goto out; |
| 2393 | |
| 2394 | /* |
| 2395 | * If extent created before last snapshot => it's shared unless the |
| 2396 | * snapshot has been deleted. Use the heuristic if strict is false. |
| 2397 | */ |
| 2398 | if (!strict && |
| 2399 | (btrfs_extent_generation(leaf, ei) <= |
| 2400 | btrfs_root_last_snapshot(&root->root_item))) |
| 2401 | goto out; |
| 2402 | |
| 2403 | /* If this extent has SHARED_DATA_REF then it's shared */ |
| 2404 | type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA); |
| 2405 | if (type != BTRFS_EXTENT_DATA_REF_KEY) |
| 2406 | goto out; |
| 2407 | |
| 2408 | ref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 2409 | if (btrfs_extent_refs(leaf, ei) != |
| 2410 | btrfs_extent_data_ref_count(leaf, ref) || |
| 2411 | btrfs_extent_data_ref_root(leaf, ref) != btrfs_root_id(root) || |
| 2412 | btrfs_extent_data_ref_objectid(leaf, ref) != objectid || |
| 2413 | btrfs_extent_data_ref_offset(leaf, ref) != offset) |
| 2414 | goto out; |
| 2415 | |
| 2416 | ret = 0; |
| 2417 | out: |
| 2418 | return ret; |
| 2419 | } |
| 2420 | |
| 2421 | int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset, |
| 2422 | u64 bytenr, bool strict, struct btrfs_path *path) |
| 2423 | { |
| 2424 | int ret; |
| 2425 | |
| 2426 | do { |
| 2427 | ret = check_committed_ref(root, path, objectid, |
| 2428 | offset, bytenr, strict); |
| 2429 | if (ret && ret != -ENOENT) |
| 2430 | goto out; |
| 2431 | |
| 2432 | ret = check_delayed_ref(root, path, objectid, offset, bytenr); |
| 2433 | } while (ret == -EAGAIN); |
| 2434 | |
| 2435 | out: |
| 2436 | btrfs_release_path(path); |
| 2437 | if (btrfs_is_data_reloc_root(root)) |
| 2438 | WARN_ON(ret > 0); |
| 2439 | return ret; |
| 2440 | } |
| 2441 | |
| 2442 | static int __btrfs_mod_ref(struct btrfs_trans_handle *trans, |
| 2443 | struct btrfs_root *root, |
| 2444 | struct extent_buffer *buf, |
| 2445 | int full_backref, int inc) |
| 2446 | { |
| 2447 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 2448 | u64 parent; |
| 2449 | u64 ref_root; |
| 2450 | u32 nritems; |
| 2451 | struct btrfs_key key; |
| 2452 | struct btrfs_file_extent_item *fi; |
| 2453 | bool for_reloc = btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC); |
| 2454 | int i; |
| 2455 | int action; |
| 2456 | int level; |
| 2457 | int ret = 0; |
| 2458 | |
| 2459 | if (btrfs_is_testing(fs_info)) |
| 2460 | return 0; |
| 2461 | |
| 2462 | ref_root = btrfs_header_owner(buf); |
| 2463 | nritems = btrfs_header_nritems(buf); |
| 2464 | level = btrfs_header_level(buf); |
| 2465 | |
| 2466 | if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && level == 0) |
| 2467 | return 0; |
| 2468 | |
| 2469 | if (full_backref) |
| 2470 | parent = buf->start; |
| 2471 | else |
| 2472 | parent = 0; |
| 2473 | if (inc) |
| 2474 | action = BTRFS_ADD_DELAYED_REF; |
| 2475 | else |
| 2476 | action = BTRFS_DROP_DELAYED_REF; |
| 2477 | |
| 2478 | for (i = 0; i < nritems; i++) { |
| 2479 | struct btrfs_ref ref = { |
| 2480 | .action = action, |
| 2481 | .parent = parent, |
| 2482 | .ref_root = ref_root, |
| 2483 | }; |
| 2484 | |
| 2485 | if (level == 0) { |
| 2486 | btrfs_item_key_to_cpu(buf, &key, i); |
| 2487 | if (key.type != BTRFS_EXTENT_DATA_KEY) |
| 2488 | continue; |
| 2489 | fi = btrfs_item_ptr(buf, i, |
| 2490 | struct btrfs_file_extent_item); |
| 2491 | if (btrfs_file_extent_type(buf, fi) == |
| 2492 | BTRFS_FILE_EXTENT_INLINE) |
| 2493 | continue; |
| 2494 | ref.bytenr = btrfs_file_extent_disk_bytenr(buf, fi); |
| 2495 | if (ref.bytenr == 0) |
| 2496 | continue; |
| 2497 | |
| 2498 | ref.num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi); |
| 2499 | ref.owning_root = ref_root; |
| 2500 | |
| 2501 | key.offset -= btrfs_file_extent_offset(buf, fi); |
| 2502 | btrfs_init_data_ref(&ref, key.objectid, key.offset, |
| 2503 | btrfs_root_id(root), for_reloc); |
| 2504 | if (inc) |
| 2505 | ret = btrfs_inc_extent_ref(trans, &ref); |
| 2506 | else |
| 2507 | ret = btrfs_free_extent(trans, &ref); |
| 2508 | if (ret) |
| 2509 | goto fail; |
| 2510 | } else { |
| 2511 | /* We don't know the owning_root, leave as 0. */ |
| 2512 | ref.bytenr = btrfs_node_blockptr(buf, i); |
| 2513 | ref.num_bytes = fs_info->nodesize; |
| 2514 | |
| 2515 | btrfs_init_tree_ref(&ref, level - 1, |
| 2516 | btrfs_root_id(root), for_reloc); |
| 2517 | if (inc) |
| 2518 | ret = btrfs_inc_extent_ref(trans, &ref); |
| 2519 | else |
| 2520 | ret = btrfs_free_extent(trans, &ref); |
| 2521 | if (ret) |
| 2522 | goto fail; |
| 2523 | } |
| 2524 | } |
| 2525 | return 0; |
| 2526 | fail: |
| 2527 | return ret; |
| 2528 | } |
| 2529 | |
| 2530 | int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| 2531 | struct extent_buffer *buf, int full_backref) |
| 2532 | { |
| 2533 | return __btrfs_mod_ref(trans, root, buf, full_backref, 1); |
| 2534 | } |
| 2535 | |
| 2536 | int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| 2537 | struct extent_buffer *buf, int full_backref) |
| 2538 | { |
| 2539 | return __btrfs_mod_ref(trans, root, buf, full_backref, 0); |
| 2540 | } |
| 2541 | |
| 2542 | static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data) |
| 2543 | { |
| 2544 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 2545 | u64 flags; |
| 2546 | u64 ret; |
| 2547 | |
| 2548 | if (data) |
| 2549 | flags = BTRFS_BLOCK_GROUP_DATA; |
| 2550 | else if (root == fs_info->chunk_root) |
| 2551 | flags = BTRFS_BLOCK_GROUP_SYSTEM; |
| 2552 | else |
| 2553 | flags = BTRFS_BLOCK_GROUP_METADATA; |
| 2554 | |
| 2555 | ret = btrfs_get_alloc_profile(fs_info, flags); |
| 2556 | return ret; |
| 2557 | } |
| 2558 | |
| 2559 | static u64 first_logical_byte(struct btrfs_fs_info *fs_info) |
| 2560 | { |
| 2561 | struct rb_node *leftmost; |
| 2562 | u64 bytenr = 0; |
| 2563 | |
| 2564 | read_lock(&fs_info->block_group_cache_lock); |
| 2565 | /* Get the block group with the lowest logical start address. */ |
| 2566 | leftmost = rb_first_cached(&fs_info->block_group_cache_tree); |
| 2567 | if (leftmost) { |
| 2568 | struct btrfs_block_group *bg; |
| 2569 | |
| 2570 | bg = rb_entry(leftmost, struct btrfs_block_group, cache_node); |
| 2571 | bytenr = bg->start; |
| 2572 | } |
| 2573 | read_unlock(&fs_info->block_group_cache_lock); |
| 2574 | |
| 2575 | return bytenr; |
| 2576 | } |
| 2577 | |
| 2578 | static int pin_down_extent(struct btrfs_trans_handle *trans, |
| 2579 | struct btrfs_block_group *cache, |
| 2580 | u64 bytenr, u64 num_bytes, int reserved) |
| 2581 | { |
| 2582 | struct btrfs_fs_info *fs_info = cache->fs_info; |
| 2583 | |
| 2584 | spin_lock(&cache->space_info->lock); |
| 2585 | spin_lock(&cache->lock); |
| 2586 | cache->pinned += num_bytes; |
| 2587 | btrfs_space_info_update_bytes_pinned(fs_info, cache->space_info, |
| 2588 | num_bytes); |
| 2589 | if (reserved) { |
| 2590 | cache->reserved -= num_bytes; |
| 2591 | cache->space_info->bytes_reserved -= num_bytes; |
| 2592 | } |
| 2593 | spin_unlock(&cache->lock); |
| 2594 | spin_unlock(&cache->space_info->lock); |
| 2595 | |
| 2596 | set_extent_bit(&trans->transaction->pinned_extents, bytenr, |
| 2597 | bytenr + num_bytes - 1, EXTENT_DIRTY, NULL); |
| 2598 | return 0; |
| 2599 | } |
| 2600 | |
| 2601 | int btrfs_pin_extent(struct btrfs_trans_handle *trans, |
| 2602 | u64 bytenr, u64 num_bytes, int reserved) |
| 2603 | { |
| 2604 | struct btrfs_block_group *cache; |
| 2605 | |
| 2606 | cache = btrfs_lookup_block_group(trans->fs_info, bytenr); |
| 2607 | BUG_ON(!cache); /* Logic error */ |
| 2608 | |
| 2609 | pin_down_extent(trans, cache, bytenr, num_bytes, reserved); |
| 2610 | |
| 2611 | btrfs_put_block_group(cache); |
| 2612 | return 0; |
| 2613 | } |
| 2614 | |
| 2615 | int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans, |
| 2616 | const struct extent_buffer *eb) |
| 2617 | { |
| 2618 | struct btrfs_block_group *cache; |
| 2619 | int ret; |
| 2620 | |
| 2621 | cache = btrfs_lookup_block_group(trans->fs_info, eb->start); |
| 2622 | if (!cache) |
| 2623 | return -EINVAL; |
| 2624 | |
| 2625 | /* |
| 2626 | * Fully cache the free space first so that our pin removes the free space |
| 2627 | * from the cache. |
| 2628 | */ |
| 2629 | ret = btrfs_cache_block_group(cache, true); |
| 2630 | if (ret) |
| 2631 | goto out; |
| 2632 | |
| 2633 | pin_down_extent(trans, cache, eb->start, eb->len, 0); |
| 2634 | |
| 2635 | /* remove us from the free space cache (if we're there at all) */ |
| 2636 | ret = btrfs_remove_free_space(cache, eb->start, eb->len); |
| 2637 | out: |
| 2638 | btrfs_put_block_group(cache); |
| 2639 | return ret; |
| 2640 | } |
| 2641 | |
| 2642 | static int __exclude_logged_extent(struct btrfs_fs_info *fs_info, |
| 2643 | u64 start, u64 num_bytes) |
| 2644 | { |
| 2645 | int ret; |
| 2646 | struct btrfs_block_group *block_group; |
| 2647 | |
| 2648 | block_group = btrfs_lookup_block_group(fs_info, start); |
| 2649 | if (!block_group) |
| 2650 | return -EINVAL; |
| 2651 | |
| 2652 | ret = btrfs_cache_block_group(block_group, true); |
| 2653 | if (ret) |
| 2654 | goto out; |
| 2655 | |
| 2656 | ret = btrfs_remove_free_space(block_group, start, num_bytes); |
| 2657 | out: |
| 2658 | btrfs_put_block_group(block_group); |
| 2659 | return ret; |
| 2660 | } |
| 2661 | |
| 2662 | int btrfs_exclude_logged_extents(struct extent_buffer *eb) |
| 2663 | { |
| 2664 | struct btrfs_fs_info *fs_info = eb->fs_info; |
| 2665 | struct btrfs_file_extent_item *item; |
| 2666 | struct btrfs_key key; |
| 2667 | int found_type; |
| 2668 | int i; |
| 2669 | int ret = 0; |
| 2670 | |
| 2671 | if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) |
| 2672 | return 0; |
| 2673 | |
| 2674 | for (i = 0; i < btrfs_header_nritems(eb); i++) { |
| 2675 | btrfs_item_key_to_cpu(eb, &key, i); |
| 2676 | if (key.type != BTRFS_EXTENT_DATA_KEY) |
| 2677 | continue; |
| 2678 | item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); |
| 2679 | found_type = btrfs_file_extent_type(eb, item); |
| 2680 | if (found_type == BTRFS_FILE_EXTENT_INLINE) |
| 2681 | continue; |
| 2682 | if (btrfs_file_extent_disk_bytenr(eb, item) == 0) |
| 2683 | continue; |
| 2684 | key.objectid = btrfs_file_extent_disk_bytenr(eb, item); |
| 2685 | key.offset = btrfs_file_extent_disk_num_bytes(eb, item); |
| 2686 | ret = __exclude_logged_extent(fs_info, key.objectid, key.offset); |
| 2687 | if (ret) |
| 2688 | break; |
| 2689 | } |
| 2690 | |
| 2691 | return ret; |
| 2692 | } |
| 2693 | |
| 2694 | static void |
| 2695 | btrfs_inc_block_group_reservations(struct btrfs_block_group *bg) |
| 2696 | { |
| 2697 | atomic_inc(&bg->reservations); |
| 2698 | } |
| 2699 | |
| 2700 | /* |
| 2701 | * Returns the free cluster for the given space info and sets empty_cluster to |
| 2702 | * what it should be based on the mount options. |
| 2703 | */ |
| 2704 | static struct btrfs_free_cluster * |
| 2705 | fetch_cluster_info(struct btrfs_fs_info *fs_info, |
| 2706 | struct btrfs_space_info *space_info, u64 *empty_cluster) |
| 2707 | { |
| 2708 | struct btrfs_free_cluster *ret = NULL; |
| 2709 | |
| 2710 | *empty_cluster = 0; |
| 2711 | if (btrfs_mixed_space_info(space_info)) |
| 2712 | return ret; |
| 2713 | |
| 2714 | if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { |
| 2715 | ret = &fs_info->meta_alloc_cluster; |
| 2716 | if (btrfs_test_opt(fs_info, SSD)) |
| 2717 | *empty_cluster = SZ_2M; |
| 2718 | else |
| 2719 | *empty_cluster = SZ_64K; |
| 2720 | } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) && |
| 2721 | btrfs_test_opt(fs_info, SSD_SPREAD)) { |
| 2722 | *empty_cluster = SZ_2M; |
| 2723 | ret = &fs_info->data_alloc_cluster; |
| 2724 | } |
| 2725 | |
| 2726 | return ret; |
| 2727 | } |
| 2728 | |
| 2729 | static int unpin_extent_range(struct btrfs_fs_info *fs_info, |
| 2730 | u64 start, u64 end, |
| 2731 | const bool return_free_space) |
| 2732 | { |
| 2733 | struct btrfs_block_group *cache = NULL; |
| 2734 | struct btrfs_space_info *space_info; |
| 2735 | struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; |
| 2736 | struct btrfs_free_cluster *cluster = NULL; |
| 2737 | u64 len; |
| 2738 | u64 total_unpinned = 0; |
| 2739 | u64 empty_cluster = 0; |
| 2740 | bool readonly; |
| 2741 | int ret = 0; |
| 2742 | |
| 2743 | while (start <= end) { |
| 2744 | readonly = false; |
| 2745 | if (!cache || |
| 2746 | start >= cache->start + cache->length) { |
| 2747 | if (cache) |
| 2748 | btrfs_put_block_group(cache); |
| 2749 | total_unpinned = 0; |
| 2750 | cache = btrfs_lookup_block_group(fs_info, start); |
| 2751 | if (cache == NULL) { |
| 2752 | /* Logic error, something removed the block group. */ |
| 2753 | ret = -EUCLEAN; |
| 2754 | goto out; |
| 2755 | } |
| 2756 | |
| 2757 | cluster = fetch_cluster_info(fs_info, |
| 2758 | cache->space_info, |
| 2759 | &empty_cluster); |
| 2760 | empty_cluster <<= 1; |
| 2761 | } |
| 2762 | |
| 2763 | len = cache->start + cache->length - start; |
| 2764 | len = min(len, end + 1 - start); |
| 2765 | |
| 2766 | if (return_free_space) |
| 2767 | btrfs_add_free_space(cache, start, len); |
| 2768 | |
| 2769 | start += len; |
| 2770 | total_unpinned += len; |
| 2771 | space_info = cache->space_info; |
| 2772 | |
| 2773 | /* |
| 2774 | * If this space cluster has been marked as fragmented and we've |
| 2775 | * unpinned enough in this block group to potentially allow a |
| 2776 | * cluster to be created inside of it go ahead and clear the |
| 2777 | * fragmented check. |
| 2778 | */ |
| 2779 | if (cluster && cluster->fragmented && |
| 2780 | total_unpinned > empty_cluster) { |
| 2781 | spin_lock(&cluster->lock); |
| 2782 | cluster->fragmented = 0; |
| 2783 | spin_unlock(&cluster->lock); |
| 2784 | } |
| 2785 | |
| 2786 | spin_lock(&space_info->lock); |
| 2787 | spin_lock(&cache->lock); |
| 2788 | cache->pinned -= len; |
| 2789 | btrfs_space_info_update_bytes_pinned(fs_info, space_info, -len); |
| 2790 | space_info->max_extent_size = 0; |
| 2791 | if (cache->ro) { |
| 2792 | space_info->bytes_readonly += len; |
| 2793 | readonly = true; |
| 2794 | } else if (btrfs_is_zoned(fs_info)) { |
| 2795 | /* Need reset before reusing in a zoned block group */ |
| 2796 | btrfs_space_info_update_bytes_zone_unusable(fs_info, space_info, |
| 2797 | len); |
| 2798 | readonly = true; |
| 2799 | } |
| 2800 | spin_unlock(&cache->lock); |
| 2801 | if (!readonly && return_free_space && |
| 2802 | global_rsv->space_info == space_info) { |
| 2803 | spin_lock(&global_rsv->lock); |
| 2804 | if (!global_rsv->full) { |
| 2805 | u64 to_add = min(len, global_rsv->size - |
| 2806 | global_rsv->reserved); |
| 2807 | |
| 2808 | global_rsv->reserved += to_add; |
| 2809 | btrfs_space_info_update_bytes_may_use(fs_info, |
| 2810 | space_info, to_add); |
| 2811 | if (global_rsv->reserved >= global_rsv->size) |
| 2812 | global_rsv->full = 1; |
| 2813 | len -= to_add; |
| 2814 | } |
| 2815 | spin_unlock(&global_rsv->lock); |
| 2816 | } |
| 2817 | /* Add to any tickets we may have */ |
| 2818 | if (!readonly && return_free_space && len) |
| 2819 | btrfs_try_granting_tickets(fs_info, space_info); |
| 2820 | spin_unlock(&space_info->lock); |
| 2821 | } |
| 2822 | |
| 2823 | if (cache) |
| 2824 | btrfs_put_block_group(cache); |
| 2825 | out: |
| 2826 | return ret; |
| 2827 | } |
| 2828 | |
| 2829 | int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans) |
| 2830 | { |
| 2831 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 2832 | struct btrfs_block_group *block_group, *tmp; |
| 2833 | struct list_head *deleted_bgs; |
| 2834 | struct extent_io_tree *unpin; |
| 2835 | u64 start; |
| 2836 | u64 end; |
| 2837 | int ret; |
| 2838 | |
| 2839 | unpin = &trans->transaction->pinned_extents; |
| 2840 | |
| 2841 | while (!TRANS_ABORTED(trans)) { |
| 2842 | struct extent_state *cached_state = NULL; |
| 2843 | |
| 2844 | mutex_lock(&fs_info->unused_bg_unpin_mutex); |
| 2845 | if (!find_first_extent_bit(unpin, 0, &start, &end, |
| 2846 | EXTENT_DIRTY, &cached_state)) { |
| 2847 | mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| 2848 | break; |
| 2849 | } |
| 2850 | |
| 2851 | if (btrfs_test_opt(fs_info, DISCARD_SYNC)) |
| 2852 | ret = btrfs_discard_extent(fs_info, start, |
| 2853 | end + 1 - start, NULL); |
| 2854 | |
| 2855 | clear_extent_dirty(unpin, start, end, &cached_state); |
| 2856 | ret = unpin_extent_range(fs_info, start, end, true); |
| 2857 | BUG_ON(ret); |
| 2858 | mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| 2859 | free_extent_state(cached_state); |
| 2860 | cond_resched(); |
| 2861 | } |
| 2862 | |
| 2863 | if (btrfs_test_opt(fs_info, DISCARD_ASYNC)) { |
| 2864 | btrfs_discard_calc_delay(&fs_info->discard_ctl); |
| 2865 | btrfs_discard_schedule_work(&fs_info->discard_ctl, true); |
| 2866 | } |
| 2867 | |
| 2868 | /* |
| 2869 | * Transaction is finished. We don't need the lock anymore. We |
| 2870 | * do need to clean up the block groups in case of a transaction |
| 2871 | * abort. |
| 2872 | */ |
| 2873 | deleted_bgs = &trans->transaction->deleted_bgs; |
| 2874 | list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) { |
| 2875 | u64 trimmed = 0; |
| 2876 | |
| 2877 | ret = -EROFS; |
| 2878 | if (!TRANS_ABORTED(trans)) |
| 2879 | ret = btrfs_discard_extent(fs_info, |
| 2880 | block_group->start, |
| 2881 | block_group->length, |
| 2882 | &trimmed); |
| 2883 | |
| 2884 | list_del_init(&block_group->bg_list); |
| 2885 | btrfs_unfreeze_block_group(block_group); |
| 2886 | btrfs_put_block_group(block_group); |
| 2887 | |
| 2888 | if (ret) { |
| 2889 | const char *errstr = btrfs_decode_error(ret); |
| 2890 | btrfs_warn(fs_info, |
| 2891 | "discard failed while removing blockgroup: errno=%d %s", |
| 2892 | ret, errstr); |
| 2893 | } |
| 2894 | } |
| 2895 | |
| 2896 | return 0; |
| 2897 | } |
| 2898 | |
| 2899 | /* |
| 2900 | * Parse an extent item's inline extents looking for a simple quotas owner ref. |
| 2901 | * |
| 2902 | * @fs_info: the btrfs_fs_info for this mount |
| 2903 | * @leaf: a leaf in the extent tree containing the extent item |
| 2904 | * @slot: the slot in the leaf where the extent item is found |
| 2905 | * |
| 2906 | * Returns the objectid of the root that originally allocated the extent item |
| 2907 | * if the inline owner ref is expected and present, otherwise 0. |
| 2908 | * |
| 2909 | * If an extent item has an owner ref item, it will be the first inline ref |
| 2910 | * item. Therefore the logic is to check whether there are any inline ref |
| 2911 | * items, then check the type of the first one. |
| 2912 | */ |
| 2913 | u64 btrfs_get_extent_owner_root(struct btrfs_fs_info *fs_info, |
| 2914 | struct extent_buffer *leaf, int slot) |
| 2915 | { |
| 2916 | struct btrfs_extent_item *ei; |
| 2917 | struct btrfs_extent_inline_ref *iref; |
| 2918 | struct btrfs_extent_owner_ref *oref; |
| 2919 | unsigned long ptr; |
| 2920 | unsigned long end; |
| 2921 | int type; |
| 2922 | |
| 2923 | if (!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)) |
| 2924 | return 0; |
| 2925 | |
| 2926 | ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); |
| 2927 | ptr = (unsigned long)(ei + 1); |
| 2928 | end = (unsigned long)ei + btrfs_item_size(leaf, slot); |
| 2929 | |
| 2930 | /* No inline ref items of any kind, can't check type. */ |
| 2931 | if (ptr == end) |
| 2932 | return 0; |
| 2933 | |
| 2934 | iref = (struct btrfs_extent_inline_ref *)ptr; |
| 2935 | type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY); |
| 2936 | |
| 2937 | /* We found an owner ref, get the root out of it. */ |
| 2938 | if (type == BTRFS_EXTENT_OWNER_REF_KEY) { |
| 2939 | oref = (struct btrfs_extent_owner_ref *)(&iref->offset); |
| 2940 | return btrfs_extent_owner_ref_root_id(leaf, oref); |
| 2941 | } |
| 2942 | |
| 2943 | /* We have inline refs, but not an owner ref. */ |
| 2944 | return 0; |
| 2945 | } |
| 2946 | |
| 2947 | static int do_free_extent_accounting(struct btrfs_trans_handle *trans, |
| 2948 | u64 bytenr, struct btrfs_squota_delta *delta) |
| 2949 | { |
| 2950 | int ret; |
| 2951 | u64 num_bytes = delta->num_bytes; |
| 2952 | |
| 2953 | if (delta->is_data) { |
| 2954 | struct btrfs_root *csum_root; |
| 2955 | |
| 2956 | csum_root = btrfs_csum_root(trans->fs_info, bytenr); |
| 2957 | ret = btrfs_del_csums(trans, csum_root, bytenr, num_bytes); |
| 2958 | if (ret) { |
| 2959 | btrfs_abort_transaction(trans, ret); |
| 2960 | return ret; |
| 2961 | } |
| 2962 | |
| 2963 | ret = btrfs_delete_raid_extent(trans, bytenr, num_bytes); |
| 2964 | if (ret) { |
| 2965 | btrfs_abort_transaction(trans, ret); |
| 2966 | return ret; |
| 2967 | } |
| 2968 | } |
| 2969 | |
| 2970 | ret = btrfs_record_squota_delta(trans->fs_info, delta); |
| 2971 | if (ret) { |
| 2972 | btrfs_abort_transaction(trans, ret); |
| 2973 | return ret; |
| 2974 | } |
| 2975 | |
| 2976 | ret = add_to_free_space_tree(trans, bytenr, num_bytes); |
| 2977 | if (ret) { |
| 2978 | btrfs_abort_transaction(trans, ret); |
| 2979 | return ret; |
| 2980 | } |
| 2981 | |
| 2982 | ret = btrfs_update_block_group(trans, bytenr, num_bytes, false); |
| 2983 | if (ret) |
| 2984 | btrfs_abort_transaction(trans, ret); |
| 2985 | |
| 2986 | return ret; |
| 2987 | } |
| 2988 | |
| 2989 | #define abort_and_dump(trans, path, fmt, args...) \ |
| 2990 | ({ \ |
| 2991 | btrfs_abort_transaction(trans, -EUCLEAN); \ |
| 2992 | btrfs_print_leaf(path->nodes[0]); \ |
| 2993 | btrfs_crit(trans->fs_info, fmt, ##args); \ |
| 2994 | }) |
| 2995 | |
| 2996 | /* |
| 2997 | * Drop one or more refs of @node. |
| 2998 | * |
| 2999 | * 1. Locate the extent refs. |
| 3000 | * It's either inline in EXTENT/METADATA_ITEM or in keyed SHARED_* item. |
| 3001 | * Locate it, then reduce the refs number or remove the ref line completely. |
| 3002 | * |
| 3003 | * 2. Update the refs count in EXTENT/METADATA_ITEM |
| 3004 | * |
| 3005 | * Inline backref case: |
| 3006 | * |
| 3007 | * in extent tree we have: |
| 3008 | * |
| 3009 | * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82 |
| 3010 | * refs 2 gen 6 flags DATA |
| 3011 | * extent data backref root FS_TREE objectid 258 offset 0 count 1 |
| 3012 | * extent data backref root FS_TREE objectid 257 offset 0 count 1 |
| 3013 | * |
| 3014 | * This function gets called with: |
| 3015 | * |
| 3016 | * node->bytenr = 13631488 |
| 3017 | * node->num_bytes = 1048576 |
| 3018 | * root_objectid = FS_TREE |
| 3019 | * owner_objectid = 257 |
| 3020 | * owner_offset = 0 |
| 3021 | * refs_to_drop = 1 |
| 3022 | * |
| 3023 | * Then we should get some like: |
| 3024 | * |
| 3025 | * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 16201 itemsize 82 |
| 3026 | * refs 1 gen 6 flags DATA |
| 3027 | * extent data backref root FS_TREE objectid 258 offset 0 count 1 |
| 3028 | * |
| 3029 | * Keyed backref case: |
| 3030 | * |
| 3031 | * in extent tree we have: |
| 3032 | * |
| 3033 | * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24 |
| 3034 | * refs 754 gen 6 flags DATA |
| 3035 | * [...] |
| 3036 | * item 2 key (13631488 EXTENT_DATA_REF <HASH>) itemoff 3915 itemsize 28 |
| 3037 | * extent data backref root FS_TREE objectid 866 offset 0 count 1 |
| 3038 | * |
| 3039 | * This function get called with: |
| 3040 | * |
| 3041 | * node->bytenr = 13631488 |
| 3042 | * node->num_bytes = 1048576 |
| 3043 | * root_objectid = FS_TREE |
| 3044 | * owner_objectid = 866 |
| 3045 | * owner_offset = 0 |
| 3046 | * refs_to_drop = 1 |
| 3047 | * |
| 3048 | * Then we should get some like: |
| 3049 | * |
| 3050 | * item 0 key (13631488 EXTENT_ITEM 1048576) itemoff 3971 itemsize 24 |
| 3051 | * refs 753 gen 6 flags DATA |
| 3052 | * |
| 3053 | * And that (13631488 EXTENT_DATA_REF <HASH>) gets removed. |
| 3054 | */ |
| 3055 | static int __btrfs_free_extent(struct btrfs_trans_handle *trans, |
| 3056 | struct btrfs_delayed_ref_head *href, |
| 3057 | struct btrfs_delayed_ref_node *node, |
| 3058 | struct btrfs_delayed_extent_op *extent_op) |
| 3059 | { |
| 3060 | struct btrfs_fs_info *info = trans->fs_info; |
| 3061 | struct btrfs_key key; |
| 3062 | struct btrfs_path *path; |
| 3063 | struct btrfs_root *extent_root; |
| 3064 | struct extent_buffer *leaf; |
| 3065 | struct btrfs_extent_item *ei; |
| 3066 | struct btrfs_extent_inline_ref *iref; |
| 3067 | int ret; |
| 3068 | int is_data; |
| 3069 | int extent_slot = 0; |
| 3070 | int found_extent = 0; |
| 3071 | int num_to_del = 1; |
| 3072 | int refs_to_drop = node->ref_mod; |
| 3073 | u32 item_size; |
| 3074 | u64 refs; |
| 3075 | u64 bytenr = node->bytenr; |
| 3076 | u64 num_bytes = node->num_bytes; |
| 3077 | u64 owner_objectid = btrfs_delayed_ref_owner(node); |
| 3078 | u64 owner_offset = btrfs_delayed_ref_offset(node); |
| 3079 | bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA); |
| 3080 | u64 delayed_ref_root = href->owning_root; |
| 3081 | |
| 3082 | extent_root = btrfs_extent_root(info, bytenr); |
| 3083 | ASSERT(extent_root); |
| 3084 | |
| 3085 | path = btrfs_alloc_path(); |
| 3086 | if (!path) |
| 3087 | return -ENOMEM; |
| 3088 | |
| 3089 | is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID; |
| 3090 | |
| 3091 | if (!is_data && refs_to_drop != 1) { |
| 3092 | btrfs_crit(info, |
| 3093 | "invalid refs_to_drop, dropping more than 1 refs for tree block %llu refs_to_drop %u", |
| 3094 | node->bytenr, refs_to_drop); |
| 3095 | ret = -EINVAL; |
| 3096 | btrfs_abort_transaction(trans, ret); |
| 3097 | goto out; |
| 3098 | } |
| 3099 | |
| 3100 | if (is_data) |
| 3101 | skinny_metadata = false; |
| 3102 | |
| 3103 | ret = lookup_extent_backref(trans, path, &iref, bytenr, num_bytes, |
| 3104 | node->parent, node->ref_root, owner_objectid, |
| 3105 | owner_offset); |
| 3106 | if (ret == 0) { |
| 3107 | /* |
| 3108 | * Either the inline backref or the SHARED_DATA_REF/ |
| 3109 | * SHARED_BLOCK_REF is found |
| 3110 | * |
| 3111 | * Here is a quick path to locate EXTENT/METADATA_ITEM. |
| 3112 | * It's possible the EXTENT/METADATA_ITEM is near current slot. |
| 3113 | */ |
| 3114 | extent_slot = path->slots[0]; |
| 3115 | while (extent_slot >= 0) { |
| 3116 | btrfs_item_key_to_cpu(path->nodes[0], &key, |
| 3117 | extent_slot); |
| 3118 | if (key.objectid != bytenr) |
| 3119 | break; |
| 3120 | if (key.type == BTRFS_EXTENT_ITEM_KEY && |
| 3121 | key.offset == num_bytes) { |
| 3122 | found_extent = 1; |
| 3123 | break; |
| 3124 | } |
| 3125 | if (key.type == BTRFS_METADATA_ITEM_KEY && |
| 3126 | key.offset == owner_objectid) { |
| 3127 | found_extent = 1; |
| 3128 | break; |
| 3129 | } |
| 3130 | |
| 3131 | /* Quick path didn't find the EXTEMT/METADATA_ITEM */ |
| 3132 | if (path->slots[0] - extent_slot > 5) |
| 3133 | break; |
| 3134 | extent_slot--; |
| 3135 | } |
| 3136 | |
| 3137 | if (!found_extent) { |
| 3138 | if (iref) { |
| 3139 | abort_and_dump(trans, path, |
| 3140 | "invalid iref slot %u, no EXTENT/METADATA_ITEM found but has inline extent ref", |
| 3141 | path->slots[0]); |
| 3142 | ret = -EUCLEAN; |
| 3143 | goto out; |
| 3144 | } |
| 3145 | /* Must be SHARED_* item, remove the backref first */ |
| 3146 | ret = remove_extent_backref(trans, extent_root, path, |
| 3147 | NULL, refs_to_drop, is_data); |
| 3148 | if (ret) { |
| 3149 | btrfs_abort_transaction(trans, ret); |
| 3150 | goto out; |
| 3151 | } |
| 3152 | btrfs_release_path(path); |
| 3153 | |
| 3154 | /* Slow path to locate EXTENT/METADATA_ITEM */ |
| 3155 | key.objectid = bytenr; |
| 3156 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 3157 | key.offset = num_bytes; |
| 3158 | |
| 3159 | if (!is_data && skinny_metadata) { |
| 3160 | key.type = BTRFS_METADATA_ITEM_KEY; |
| 3161 | key.offset = owner_objectid; |
| 3162 | } |
| 3163 | |
| 3164 | ret = btrfs_search_slot(trans, extent_root, |
| 3165 | &key, path, -1, 1); |
| 3166 | if (ret > 0 && skinny_metadata && path->slots[0]) { |
| 3167 | /* |
| 3168 | * Couldn't find our skinny metadata item, |
| 3169 | * see if we have ye olde extent item. |
| 3170 | */ |
| 3171 | path->slots[0]--; |
| 3172 | btrfs_item_key_to_cpu(path->nodes[0], &key, |
| 3173 | path->slots[0]); |
| 3174 | if (key.objectid == bytenr && |
| 3175 | key.type == BTRFS_EXTENT_ITEM_KEY && |
| 3176 | key.offset == num_bytes) |
| 3177 | ret = 0; |
| 3178 | } |
| 3179 | |
| 3180 | if (ret > 0 && skinny_metadata) { |
| 3181 | skinny_metadata = false; |
| 3182 | key.objectid = bytenr; |
| 3183 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 3184 | key.offset = num_bytes; |
| 3185 | btrfs_release_path(path); |
| 3186 | ret = btrfs_search_slot(trans, extent_root, |
| 3187 | &key, path, -1, 1); |
| 3188 | } |
| 3189 | |
| 3190 | if (ret) { |
| 3191 | if (ret > 0) |
| 3192 | btrfs_print_leaf(path->nodes[0]); |
| 3193 | btrfs_err(info, |
| 3194 | "umm, got %d back from search, was looking for %llu, slot %d", |
| 3195 | ret, bytenr, path->slots[0]); |
| 3196 | } |
| 3197 | if (ret < 0) { |
| 3198 | btrfs_abort_transaction(trans, ret); |
| 3199 | goto out; |
| 3200 | } |
| 3201 | extent_slot = path->slots[0]; |
| 3202 | } |
| 3203 | } else if (WARN_ON(ret == -ENOENT)) { |
| 3204 | abort_and_dump(trans, path, |
| 3205 | "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu slot %d", |
| 3206 | bytenr, node->parent, node->ref_root, owner_objectid, |
| 3207 | owner_offset, path->slots[0]); |
| 3208 | goto out; |
| 3209 | } else { |
| 3210 | btrfs_abort_transaction(trans, ret); |
| 3211 | goto out; |
| 3212 | } |
| 3213 | |
| 3214 | leaf = path->nodes[0]; |
| 3215 | item_size = btrfs_item_size(leaf, extent_slot); |
| 3216 | if (unlikely(item_size < sizeof(*ei))) { |
| 3217 | ret = -EUCLEAN; |
| 3218 | btrfs_err(trans->fs_info, |
| 3219 | "unexpected extent item size, has %u expect >= %zu", |
| 3220 | item_size, sizeof(*ei)); |
| 3221 | btrfs_abort_transaction(trans, ret); |
| 3222 | goto out; |
| 3223 | } |
| 3224 | ei = btrfs_item_ptr(leaf, extent_slot, |
| 3225 | struct btrfs_extent_item); |
| 3226 | if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID && |
| 3227 | key.type == BTRFS_EXTENT_ITEM_KEY) { |
| 3228 | struct btrfs_tree_block_info *bi; |
| 3229 | |
| 3230 | if (item_size < sizeof(*ei) + sizeof(*bi)) { |
| 3231 | abort_and_dump(trans, path, |
| 3232 | "invalid extent item size for key (%llu, %u, %llu) slot %u owner %llu, has %u expect >= %zu", |
| 3233 | key.objectid, key.type, key.offset, |
| 3234 | path->slots[0], owner_objectid, item_size, |
| 3235 | sizeof(*ei) + sizeof(*bi)); |
| 3236 | ret = -EUCLEAN; |
| 3237 | goto out; |
| 3238 | } |
| 3239 | bi = (struct btrfs_tree_block_info *)(ei + 1); |
| 3240 | WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi)); |
| 3241 | } |
| 3242 | |
| 3243 | refs = btrfs_extent_refs(leaf, ei); |
| 3244 | if (refs < refs_to_drop) { |
| 3245 | abort_and_dump(trans, path, |
| 3246 | "trying to drop %d refs but we only have %llu for bytenr %llu slot %u", |
| 3247 | refs_to_drop, refs, bytenr, path->slots[0]); |
| 3248 | ret = -EUCLEAN; |
| 3249 | goto out; |
| 3250 | } |
| 3251 | refs -= refs_to_drop; |
| 3252 | |
| 3253 | if (refs > 0) { |
| 3254 | if (extent_op) |
| 3255 | __run_delayed_extent_op(extent_op, leaf, ei); |
| 3256 | /* |
| 3257 | * In the case of inline back ref, reference count will |
| 3258 | * be updated by remove_extent_backref |
| 3259 | */ |
| 3260 | if (iref) { |
| 3261 | if (!found_extent) { |
| 3262 | abort_and_dump(trans, path, |
| 3263 | "invalid iref, got inlined extent ref but no EXTENT/METADATA_ITEM found, slot %u", |
| 3264 | path->slots[0]); |
| 3265 | ret = -EUCLEAN; |
| 3266 | goto out; |
| 3267 | } |
| 3268 | } else { |
| 3269 | btrfs_set_extent_refs(leaf, ei, refs); |
| 3270 | btrfs_mark_buffer_dirty(trans, leaf); |
| 3271 | } |
| 3272 | if (found_extent) { |
| 3273 | ret = remove_extent_backref(trans, extent_root, path, |
| 3274 | iref, refs_to_drop, is_data); |
| 3275 | if (ret) { |
| 3276 | btrfs_abort_transaction(trans, ret); |
| 3277 | goto out; |
| 3278 | } |
| 3279 | } |
| 3280 | } else { |
| 3281 | struct btrfs_squota_delta delta = { |
| 3282 | .root = delayed_ref_root, |
| 3283 | .num_bytes = num_bytes, |
| 3284 | .is_data = is_data, |
| 3285 | .is_inc = false, |
| 3286 | .generation = btrfs_extent_generation(leaf, ei), |
| 3287 | }; |
| 3288 | |
| 3289 | /* In this branch refs == 1 */ |
| 3290 | if (found_extent) { |
| 3291 | if (is_data && refs_to_drop != |
| 3292 | extent_data_ref_count(path, iref)) { |
| 3293 | abort_and_dump(trans, path, |
| 3294 | "invalid refs_to_drop, current refs %u refs_to_drop %u slot %u", |
| 3295 | extent_data_ref_count(path, iref), |
| 3296 | refs_to_drop, path->slots[0]); |
| 3297 | ret = -EUCLEAN; |
| 3298 | goto out; |
| 3299 | } |
| 3300 | if (iref) { |
| 3301 | if (path->slots[0] != extent_slot) { |
| 3302 | abort_and_dump(trans, path, |
| 3303 | "invalid iref, extent item key (%llu %u %llu) slot %u doesn't have wanted iref", |
| 3304 | key.objectid, key.type, |
| 3305 | key.offset, path->slots[0]); |
| 3306 | ret = -EUCLEAN; |
| 3307 | goto out; |
| 3308 | } |
| 3309 | } else { |
| 3310 | /* |
| 3311 | * No inline ref, we must be at SHARED_* item, |
| 3312 | * And it's single ref, it must be: |
| 3313 | * | extent_slot ||extent_slot + 1| |
| 3314 | * [ EXTENT/METADATA_ITEM ][ SHARED_* ITEM ] |
| 3315 | */ |
| 3316 | if (path->slots[0] != extent_slot + 1) { |
| 3317 | abort_and_dump(trans, path, |
| 3318 | "invalid SHARED_* item slot %u, previous item is not EXTENT/METADATA_ITEM", |
| 3319 | path->slots[0]); |
| 3320 | ret = -EUCLEAN; |
| 3321 | goto out; |
| 3322 | } |
| 3323 | path->slots[0] = extent_slot; |
| 3324 | num_to_del = 2; |
| 3325 | } |
| 3326 | } |
| 3327 | /* |
| 3328 | * We can't infer the data owner from the delayed ref, so we need |
| 3329 | * to try to get it from the owning ref item. |
| 3330 | * |
| 3331 | * If it is not present, then that extent was not written under |
| 3332 | * simple quotas mode, so we don't need to account for its deletion. |
| 3333 | */ |
| 3334 | if (is_data) |
| 3335 | delta.root = btrfs_get_extent_owner_root(trans->fs_info, |
| 3336 | leaf, extent_slot); |
| 3337 | |
| 3338 | ret = btrfs_del_items(trans, extent_root, path, path->slots[0], |
| 3339 | num_to_del); |
| 3340 | if (ret) { |
| 3341 | btrfs_abort_transaction(trans, ret); |
| 3342 | goto out; |
| 3343 | } |
| 3344 | btrfs_release_path(path); |
| 3345 | |
| 3346 | ret = do_free_extent_accounting(trans, bytenr, &delta); |
| 3347 | } |
| 3348 | btrfs_release_path(path); |
| 3349 | |
| 3350 | out: |
| 3351 | btrfs_free_path(path); |
| 3352 | return ret; |
| 3353 | } |
| 3354 | |
| 3355 | /* |
| 3356 | * when we free an block, it is possible (and likely) that we free the last |
| 3357 | * delayed ref for that extent as well. This searches the delayed ref tree for |
| 3358 | * a given extent, and if there are no other delayed refs to be processed, it |
| 3359 | * removes it from the tree. |
| 3360 | */ |
| 3361 | static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, |
| 3362 | u64 bytenr) |
| 3363 | { |
| 3364 | struct btrfs_delayed_ref_head *head; |
| 3365 | struct btrfs_delayed_ref_root *delayed_refs; |
| 3366 | int ret = 0; |
| 3367 | |
| 3368 | delayed_refs = &trans->transaction->delayed_refs; |
| 3369 | spin_lock(&delayed_refs->lock); |
| 3370 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
| 3371 | if (!head) |
| 3372 | goto out_delayed_unlock; |
| 3373 | |
| 3374 | spin_lock(&head->lock); |
| 3375 | if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root)) |
| 3376 | goto out; |
| 3377 | |
| 3378 | if (cleanup_extent_op(head) != NULL) |
| 3379 | goto out; |
| 3380 | |
| 3381 | /* |
| 3382 | * waiting for the lock here would deadlock. If someone else has it |
| 3383 | * locked they are already in the process of dropping it anyway |
| 3384 | */ |
| 3385 | if (!mutex_trylock(&head->mutex)) |
| 3386 | goto out; |
| 3387 | |
| 3388 | btrfs_delete_ref_head(delayed_refs, head); |
| 3389 | head->processing = false; |
| 3390 | |
| 3391 | spin_unlock(&head->lock); |
| 3392 | spin_unlock(&delayed_refs->lock); |
| 3393 | |
| 3394 | BUG_ON(head->extent_op); |
| 3395 | if (head->must_insert_reserved) |
| 3396 | ret = 1; |
| 3397 | |
| 3398 | btrfs_cleanup_ref_head_accounting(trans->fs_info, delayed_refs, head); |
| 3399 | mutex_unlock(&head->mutex); |
| 3400 | btrfs_put_delayed_ref_head(head); |
| 3401 | return ret; |
| 3402 | out: |
| 3403 | spin_unlock(&head->lock); |
| 3404 | |
| 3405 | out_delayed_unlock: |
| 3406 | spin_unlock(&delayed_refs->lock); |
| 3407 | return 0; |
| 3408 | } |
| 3409 | |
| 3410 | int btrfs_free_tree_block(struct btrfs_trans_handle *trans, |
| 3411 | u64 root_id, |
| 3412 | struct extent_buffer *buf, |
| 3413 | u64 parent, int last_ref) |
| 3414 | { |
| 3415 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 3416 | struct btrfs_block_group *bg; |
| 3417 | int ret; |
| 3418 | |
| 3419 | if (root_id != BTRFS_TREE_LOG_OBJECTID) { |
| 3420 | struct btrfs_ref generic_ref = { |
| 3421 | .action = BTRFS_DROP_DELAYED_REF, |
| 3422 | .bytenr = buf->start, |
| 3423 | .num_bytes = buf->len, |
| 3424 | .parent = parent, |
| 3425 | .owning_root = btrfs_header_owner(buf), |
| 3426 | .ref_root = root_id, |
| 3427 | }; |
| 3428 | |
| 3429 | /* |
| 3430 | * Assert that the extent buffer is not cleared due to |
| 3431 | * EXTENT_BUFFER_ZONED_ZEROOUT. Please refer |
| 3432 | * btrfs_clear_buffer_dirty() and btree_csum_one_bio() for |
| 3433 | * detail. |
| 3434 | */ |
| 3435 | ASSERT(btrfs_header_bytenr(buf) != 0); |
| 3436 | |
| 3437 | btrfs_init_tree_ref(&generic_ref, btrfs_header_level(buf), 0, false); |
| 3438 | btrfs_ref_tree_mod(fs_info, &generic_ref); |
| 3439 | ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL); |
| 3440 | if (ret < 0) |
| 3441 | return ret; |
| 3442 | } |
| 3443 | |
| 3444 | if (!last_ref) |
| 3445 | return 0; |
| 3446 | |
| 3447 | if (btrfs_header_generation(buf) != trans->transid) |
| 3448 | goto out; |
| 3449 | |
| 3450 | if (root_id != BTRFS_TREE_LOG_OBJECTID) { |
| 3451 | ret = check_ref_cleanup(trans, buf->start); |
| 3452 | if (!ret) |
| 3453 | goto out; |
| 3454 | } |
| 3455 | |
| 3456 | bg = btrfs_lookup_block_group(fs_info, buf->start); |
| 3457 | |
| 3458 | if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { |
| 3459 | pin_down_extent(trans, bg, buf->start, buf->len, 1); |
| 3460 | btrfs_put_block_group(bg); |
| 3461 | goto out; |
| 3462 | } |
| 3463 | |
| 3464 | /* |
| 3465 | * If there are tree mod log users we may have recorded mod log |
| 3466 | * operations for this node. If we re-allocate this node we |
| 3467 | * could replay operations on this node that happened when it |
| 3468 | * existed in a completely different root. For example if it |
| 3469 | * was part of root A, then was reallocated to root B, and we |
| 3470 | * are doing a btrfs_old_search_slot(root b), we could replay |
| 3471 | * operations that happened when the block was part of root A, |
| 3472 | * giving us an inconsistent view of the btree. |
| 3473 | * |
| 3474 | * We are safe from races here because at this point no other |
| 3475 | * node or root points to this extent buffer, so if after this |
| 3476 | * check a new tree mod log user joins we will not have an |
| 3477 | * existing log of operations on this node that we have to |
| 3478 | * contend with. |
| 3479 | */ |
| 3480 | |
| 3481 | if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags) |
| 3482 | || btrfs_is_zoned(fs_info)) { |
| 3483 | pin_down_extent(trans, bg, buf->start, buf->len, 1); |
| 3484 | btrfs_put_block_group(bg); |
| 3485 | goto out; |
| 3486 | } |
| 3487 | |
| 3488 | WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)); |
| 3489 | |
| 3490 | btrfs_add_free_space(bg, buf->start, buf->len); |
| 3491 | btrfs_free_reserved_bytes(bg, buf->len, 0); |
| 3492 | btrfs_put_block_group(bg); |
| 3493 | trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len); |
| 3494 | |
| 3495 | out: |
| 3496 | |
| 3497 | /* |
| 3498 | * Deleting the buffer, clear the corrupt flag since it doesn't |
| 3499 | * matter anymore. |
| 3500 | */ |
| 3501 | clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags); |
| 3502 | return 0; |
| 3503 | } |
| 3504 | |
| 3505 | /* Can return -ENOMEM */ |
| 3506 | int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref) |
| 3507 | { |
| 3508 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 3509 | int ret; |
| 3510 | |
| 3511 | if (btrfs_is_testing(fs_info)) |
| 3512 | return 0; |
| 3513 | |
| 3514 | /* |
| 3515 | * tree log blocks never actually go into the extent allocation |
| 3516 | * tree, just update pinning info and exit early. |
| 3517 | */ |
| 3518 | if (ref->ref_root == BTRFS_TREE_LOG_OBJECTID) { |
| 3519 | btrfs_pin_extent(trans, ref->bytenr, ref->num_bytes, 1); |
| 3520 | ret = 0; |
| 3521 | } else if (ref->type == BTRFS_REF_METADATA) { |
| 3522 | ret = btrfs_add_delayed_tree_ref(trans, ref, NULL); |
| 3523 | } else { |
| 3524 | ret = btrfs_add_delayed_data_ref(trans, ref, 0); |
| 3525 | } |
| 3526 | |
| 3527 | if (ref->ref_root != BTRFS_TREE_LOG_OBJECTID) |
| 3528 | btrfs_ref_tree_mod(fs_info, ref); |
| 3529 | |
| 3530 | return ret; |
| 3531 | } |
| 3532 | |
| 3533 | enum btrfs_loop_type { |
| 3534 | /* |
| 3535 | * Start caching block groups but do not wait for progress or for them |
| 3536 | * to be done. |
| 3537 | */ |
| 3538 | LOOP_CACHING_NOWAIT, |
| 3539 | |
| 3540 | /* |
| 3541 | * Wait for the block group free_space >= the space we're waiting for if |
| 3542 | * the block group isn't cached. |
| 3543 | */ |
| 3544 | LOOP_CACHING_WAIT, |
| 3545 | |
| 3546 | /* |
| 3547 | * Allow allocations to happen from block groups that do not yet have a |
| 3548 | * size classification. |
| 3549 | */ |
| 3550 | LOOP_UNSET_SIZE_CLASS, |
| 3551 | |
| 3552 | /* |
| 3553 | * Allocate a chunk and then retry the allocation. |
| 3554 | */ |
| 3555 | LOOP_ALLOC_CHUNK, |
| 3556 | |
| 3557 | /* |
| 3558 | * Ignore the size class restrictions for this allocation. |
| 3559 | */ |
| 3560 | LOOP_WRONG_SIZE_CLASS, |
| 3561 | |
| 3562 | /* |
| 3563 | * Ignore the empty size, only try to allocate the number of bytes |
| 3564 | * needed for this allocation. |
| 3565 | */ |
| 3566 | LOOP_NO_EMPTY_SIZE, |
| 3567 | }; |
| 3568 | |
| 3569 | static inline void |
| 3570 | btrfs_lock_block_group(struct btrfs_block_group *cache, |
| 3571 | int delalloc) |
| 3572 | { |
| 3573 | if (delalloc) |
| 3574 | down_read(&cache->data_rwsem); |
| 3575 | } |
| 3576 | |
| 3577 | static inline void btrfs_grab_block_group(struct btrfs_block_group *cache, |
| 3578 | int delalloc) |
| 3579 | { |
| 3580 | btrfs_get_block_group(cache); |
| 3581 | if (delalloc) |
| 3582 | down_read(&cache->data_rwsem); |
| 3583 | } |
| 3584 | |
| 3585 | static struct btrfs_block_group *btrfs_lock_cluster( |
| 3586 | struct btrfs_block_group *block_group, |
| 3587 | struct btrfs_free_cluster *cluster, |
| 3588 | int delalloc) |
| 3589 | __acquires(&cluster->refill_lock) |
| 3590 | { |
| 3591 | struct btrfs_block_group *used_bg = NULL; |
| 3592 | |
| 3593 | spin_lock(&cluster->refill_lock); |
| 3594 | while (1) { |
| 3595 | used_bg = cluster->block_group; |
| 3596 | if (!used_bg) |
| 3597 | return NULL; |
| 3598 | |
| 3599 | if (used_bg == block_group) |
| 3600 | return used_bg; |
| 3601 | |
| 3602 | btrfs_get_block_group(used_bg); |
| 3603 | |
| 3604 | if (!delalloc) |
| 3605 | return used_bg; |
| 3606 | |
| 3607 | if (down_read_trylock(&used_bg->data_rwsem)) |
| 3608 | return used_bg; |
| 3609 | |
| 3610 | spin_unlock(&cluster->refill_lock); |
| 3611 | |
| 3612 | /* We should only have one-level nested. */ |
| 3613 | down_read_nested(&used_bg->data_rwsem, SINGLE_DEPTH_NESTING); |
| 3614 | |
| 3615 | spin_lock(&cluster->refill_lock); |
| 3616 | if (used_bg == cluster->block_group) |
| 3617 | return used_bg; |
| 3618 | |
| 3619 | up_read(&used_bg->data_rwsem); |
| 3620 | btrfs_put_block_group(used_bg); |
| 3621 | } |
| 3622 | } |
| 3623 | |
| 3624 | static inline void |
| 3625 | btrfs_release_block_group(struct btrfs_block_group *cache, |
| 3626 | int delalloc) |
| 3627 | { |
| 3628 | if (delalloc) |
| 3629 | up_read(&cache->data_rwsem); |
| 3630 | btrfs_put_block_group(cache); |
| 3631 | } |
| 3632 | |
| 3633 | /* |
| 3634 | * Helper function for find_free_extent(). |
| 3635 | * |
| 3636 | * Return -ENOENT to inform caller that we need fallback to unclustered mode. |
| 3637 | * Return >0 to inform caller that we find nothing |
| 3638 | * Return 0 means we have found a location and set ffe_ctl->found_offset. |
| 3639 | */ |
| 3640 | static int find_free_extent_clustered(struct btrfs_block_group *bg, |
| 3641 | struct find_free_extent_ctl *ffe_ctl, |
| 3642 | struct btrfs_block_group **cluster_bg_ret) |
| 3643 | { |
| 3644 | struct btrfs_block_group *cluster_bg; |
| 3645 | struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr; |
| 3646 | u64 aligned_cluster; |
| 3647 | u64 offset; |
| 3648 | int ret; |
| 3649 | |
| 3650 | cluster_bg = btrfs_lock_cluster(bg, last_ptr, ffe_ctl->delalloc); |
| 3651 | if (!cluster_bg) |
| 3652 | goto refill_cluster; |
| 3653 | if (cluster_bg != bg && (cluster_bg->ro || |
| 3654 | !block_group_bits(cluster_bg, ffe_ctl->flags))) |
| 3655 | goto release_cluster; |
| 3656 | |
| 3657 | offset = btrfs_alloc_from_cluster(cluster_bg, last_ptr, |
| 3658 | ffe_ctl->num_bytes, cluster_bg->start, |
| 3659 | &ffe_ctl->max_extent_size); |
| 3660 | if (offset) { |
| 3661 | /* We have a block, we're done */ |
| 3662 | spin_unlock(&last_ptr->refill_lock); |
| 3663 | trace_btrfs_reserve_extent_cluster(cluster_bg, ffe_ctl); |
| 3664 | *cluster_bg_ret = cluster_bg; |
| 3665 | ffe_ctl->found_offset = offset; |
| 3666 | return 0; |
| 3667 | } |
| 3668 | WARN_ON(last_ptr->block_group != cluster_bg); |
| 3669 | |
| 3670 | release_cluster: |
| 3671 | /* |
| 3672 | * If we are on LOOP_NO_EMPTY_SIZE, we can't set up a new clusters, so |
| 3673 | * lets just skip it and let the allocator find whatever block it can |
| 3674 | * find. If we reach this point, we will have tried the cluster |
| 3675 | * allocator plenty of times and not have found anything, so we are |
| 3676 | * likely way too fragmented for the clustering stuff to find anything. |
| 3677 | * |
| 3678 | * However, if the cluster is taken from the current block group, |
| 3679 | * release the cluster first, so that we stand a better chance of |
| 3680 | * succeeding in the unclustered allocation. |
| 3681 | */ |
| 3682 | if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE && cluster_bg != bg) { |
| 3683 | spin_unlock(&last_ptr->refill_lock); |
| 3684 | btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc); |
| 3685 | return -ENOENT; |
| 3686 | } |
| 3687 | |
| 3688 | /* This cluster didn't work out, free it and start over */ |
| 3689 | btrfs_return_cluster_to_free_space(NULL, last_ptr); |
| 3690 | |
| 3691 | if (cluster_bg != bg) |
| 3692 | btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc); |
| 3693 | |
| 3694 | refill_cluster: |
| 3695 | if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE) { |
| 3696 | spin_unlock(&last_ptr->refill_lock); |
| 3697 | return -ENOENT; |
| 3698 | } |
| 3699 | |
| 3700 | aligned_cluster = max_t(u64, |
| 3701 | ffe_ctl->empty_cluster + ffe_ctl->empty_size, |
| 3702 | bg->full_stripe_len); |
| 3703 | ret = btrfs_find_space_cluster(bg, last_ptr, ffe_ctl->search_start, |
| 3704 | ffe_ctl->num_bytes, aligned_cluster); |
| 3705 | if (ret == 0) { |
| 3706 | /* Now pull our allocation out of this cluster */ |
| 3707 | offset = btrfs_alloc_from_cluster(bg, last_ptr, |
| 3708 | ffe_ctl->num_bytes, ffe_ctl->search_start, |
| 3709 | &ffe_ctl->max_extent_size); |
| 3710 | if (offset) { |
| 3711 | /* We found one, proceed */ |
| 3712 | spin_unlock(&last_ptr->refill_lock); |
| 3713 | ffe_ctl->found_offset = offset; |
| 3714 | trace_btrfs_reserve_extent_cluster(bg, ffe_ctl); |
| 3715 | return 0; |
| 3716 | } |
| 3717 | } |
| 3718 | /* |
| 3719 | * At this point we either didn't find a cluster or we weren't able to |
| 3720 | * allocate a block from our cluster. Free the cluster we've been |
| 3721 | * trying to use, and go to the next block group. |
| 3722 | */ |
| 3723 | btrfs_return_cluster_to_free_space(NULL, last_ptr); |
| 3724 | spin_unlock(&last_ptr->refill_lock); |
| 3725 | return 1; |
| 3726 | } |
| 3727 | |
| 3728 | /* |
| 3729 | * Return >0 to inform caller that we find nothing |
| 3730 | * Return 0 when we found an free extent and set ffe_ctrl->found_offset |
| 3731 | */ |
| 3732 | static int find_free_extent_unclustered(struct btrfs_block_group *bg, |
| 3733 | struct find_free_extent_ctl *ffe_ctl) |
| 3734 | { |
| 3735 | struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr; |
| 3736 | u64 offset; |
| 3737 | |
| 3738 | /* |
| 3739 | * We are doing an unclustered allocation, set the fragmented flag so |
| 3740 | * we don't bother trying to setup a cluster again until we get more |
| 3741 | * space. |
| 3742 | */ |
| 3743 | if (unlikely(last_ptr)) { |
| 3744 | spin_lock(&last_ptr->lock); |
| 3745 | last_ptr->fragmented = 1; |
| 3746 | spin_unlock(&last_ptr->lock); |
| 3747 | } |
| 3748 | if (ffe_ctl->cached) { |
| 3749 | struct btrfs_free_space_ctl *free_space_ctl; |
| 3750 | |
| 3751 | free_space_ctl = bg->free_space_ctl; |
| 3752 | spin_lock(&free_space_ctl->tree_lock); |
| 3753 | if (free_space_ctl->free_space < |
| 3754 | ffe_ctl->num_bytes + ffe_ctl->empty_cluster + |
| 3755 | ffe_ctl->empty_size) { |
| 3756 | ffe_ctl->total_free_space = max_t(u64, |
| 3757 | ffe_ctl->total_free_space, |
| 3758 | free_space_ctl->free_space); |
| 3759 | spin_unlock(&free_space_ctl->tree_lock); |
| 3760 | return 1; |
| 3761 | } |
| 3762 | spin_unlock(&free_space_ctl->tree_lock); |
| 3763 | } |
| 3764 | |
| 3765 | offset = btrfs_find_space_for_alloc(bg, ffe_ctl->search_start, |
| 3766 | ffe_ctl->num_bytes, ffe_ctl->empty_size, |
| 3767 | &ffe_ctl->max_extent_size); |
| 3768 | if (!offset) |
| 3769 | return 1; |
| 3770 | ffe_ctl->found_offset = offset; |
| 3771 | return 0; |
| 3772 | } |
| 3773 | |
| 3774 | static int do_allocation_clustered(struct btrfs_block_group *block_group, |
| 3775 | struct find_free_extent_ctl *ffe_ctl, |
| 3776 | struct btrfs_block_group **bg_ret) |
| 3777 | { |
| 3778 | int ret; |
| 3779 | |
| 3780 | /* We want to try and use the cluster allocator, so lets look there */ |
| 3781 | if (ffe_ctl->last_ptr && ffe_ctl->use_cluster) { |
| 3782 | ret = find_free_extent_clustered(block_group, ffe_ctl, bg_ret); |
| 3783 | if (ret >= 0) |
| 3784 | return ret; |
| 3785 | /* ret == -ENOENT case falls through */ |
| 3786 | } |
| 3787 | |
| 3788 | return find_free_extent_unclustered(block_group, ffe_ctl); |
| 3789 | } |
| 3790 | |
| 3791 | /* |
| 3792 | * Tree-log block group locking |
| 3793 | * ============================ |
| 3794 | * |
| 3795 | * fs_info::treelog_bg_lock protects the fs_info::treelog_bg which |
| 3796 | * indicates the starting address of a block group, which is reserved only |
| 3797 | * for tree-log metadata. |
| 3798 | * |
| 3799 | * Lock nesting |
| 3800 | * ============ |
| 3801 | * |
| 3802 | * space_info::lock |
| 3803 | * block_group::lock |
| 3804 | * fs_info::treelog_bg_lock |
| 3805 | */ |
| 3806 | |
| 3807 | /* |
| 3808 | * Simple allocator for sequential-only block group. It only allows sequential |
| 3809 | * allocation. No need to play with trees. This function also reserves the |
| 3810 | * bytes as in btrfs_add_reserved_bytes. |
| 3811 | */ |
| 3812 | static int do_allocation_zoned(struct btrfs_block_group *block_group, |
| 3813 | struct find_free_extent_ctl *ffe_ctl, |
| 3814 | struct btrfs_block_group **bg_ret) |
| 3815 | { |
| 3816 | struct btrfs_fs_info *fs_info = block_group->fs_info; |
| 3817 | struct btrfs_space_info *space_info = block_group->space_info; |
| 3818 | struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; |
| 3819 | u64 start = block_group->start; |
| 3820 | u64 num_bytes = ffe_ctl->num_bytes; |
| 3821 | u64 avail; |
| 3822 | u64 bytenr = block_group->start; |
| 3823 | u64 log_bytenr; |
| 3824 | u64 data_reloc_bytenr; |
| 3825 | int ret = 0; |
| 3826 | bool skip = false; |
| 3827 | |
| 3828 | ASSERT(btrfs_is_zoned(block_group->fs_info)); |
| 3829 | |
| 3830 | /* |
| 3831 | * Do not allow non-tree-log blocks in the dedicated tree-log block |
| 3832 | * group, and vice versa. |
| 3833 | */ |
| 3834 | spin_lock(&fs_info->treelog_bg_lock); |
| 3835 | log_bytenr = fs_info->treelog_bg; |
| 3836 | if (log_bytenr && ((ffe_ctl->for_treelog && bytenr != log_bytenr) || |
| 3837 | (!ffe_ctl->for_treelog && bytenr == log_bytenr))) |
| 3838 | skip = true; |
| 3839 | spin_unlock(&fs_info->treelog_bg_lock); |
| 3840 | if (skip) |
| 3841 | return 1; |
| 3842 | |
| 3843 | /* |
| 3844 | * Do not allow non-relocation blocks in the dedicated relocation block |
| 3845 | * group, and vice versa. |
| 3846 | */ |
| 3847 | spin_lock(&fs_info->relocation_bg_lock); |
| 3848 | data_reloc_bytenr = fs_info->data_reloc_bg; |
| 3849 | if (data_reloc_bytenr && |
| 3850 | ((ffe_ctl->for_data_reloc && bytenr != data_reloc_bytenr) || |
| 3851 | (!ffe_ctl->for_data_reloc && bytenr == data_reloc_bytenr))) |
| 3852 | skip = true; |
| 3853 | spin_unlock(&fs_info->relocation_bg_lock); |
| 3854 | if (skip) |
| 3855 | return 1; |
| 3856 | |
| 3857 | /* Check RO and no space case before trying to activate it */ |
| 3858 | spin_lock(&block_group->lock); |
| 3859 | if (block_group->ro || btrfs_zoned_bg_is_full(block_group)) { |
| 3860 | ret = 1; |
| 3861 | /* |
| 3862 | * May need to clear fs_info->{treelog,data_reloc}_bg. |
| 3863 | * Return the error after taking the locks. |
| 3864 | */ |
| 3865 | } |
| 3866 | spin_unlock(&block_group->lock); |
| 3867 | |
| 3868 | /* Metadata block group is activated at write time. */ |
| 3869 | if (!ret && (block_group->flags & BTRFS_BLOCK_GROUP_DATA) && |
| 3870 | !btrfs_zone_activate(block_group)) { |
| 3871 | ret = 1; |
| 3872 | /* |
| 3873 | * May need to clear fs_info->{treelog,data_reloc}_bg. |
| 3874 | * Return the error after taking the locks. |
| 3875 | */ |
| 3876 | } |
| 3877 | |
| 3878 | spin_lock(&space_info->lock); |
| 3879 | spin_lock(&block_group->lock); |
| 3880 | spin_lock(&fs_info->treelog_bg_lock); |
| 3881 | spin_lock(&fs_info->relocation_bg_lock); |
| 3882 | |
| 3883 | if (ret) |
| 3884 | goto out; |
| 3885 | |
| 3886 | ASSERT(!ffe_ctl->for_treelog || |
| 3887 | block_group->start == fs_info->treelog_bg || |
| 3888 | fs_info->treelog_bg == 0); |
| 3889 | ASSERT(!ffe_ctl->for_data_reloc || |
| 3890 | block_group->start == fs_info->data_reloc_bg || |
| 3891 | fs_info->data_reloc_bg == 0); |
| 3892 | |
| 3893 | if (block_group->ro || |
| 3894 | (!ffe_ctl->for_data_reloc && |
| 3895 | test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags))) { |
| 3896 | ret = 1; |
| 3897 | goto out; |
| 3898 | } |
| 3899 | |
| 3900 | /* |
| 3901 | * Do not allow currently using block group to be tree-log dedicated |
| 3902 | * block group. |
| 3903 | */ |
| 3904 | if (ffe_ctl->for_treelog && !fs_info->treelog_bg && |
| 3905 | (block_group->used || block_group->reserved)) { |
| 3906 | ret = 1; |
| 3907 | goto out; |
| 3908 | } |
| 3909 | |
| 3910 | /* |
| 3911 | * Do not allow currently used block group to be the data relocation |
| 3912 | * dedicated block group. |
| 3913 | */ |
| 3914 | if (ffe_ctl->for_data_reloc && !fs_info->data_reloc_bg && |
| 3915 | (block_group->used || block_group->reserved)) { |
| 3916 | ret = 1; |
| 3917 | goto out; |
| 3918 | } |
| 3919 | |
| 3920 | WARN_ON_ONCE(block_group->alloc_offset > block_group->zone_capacity); |
| 3921 | avail = block_group->zone_capacity - block_group->alloc_offset; |
| 3922 | if (avail < num_bytes) { |
| 3923 | if (ffe_ctl->max_extent_size < avail) { |
| 3924 | /* |
| 3925 | * With sequential allocator, free space is always |
| 3926 | * contiguous |
| 3927 | */ |
| 3928 | ffe_ctl->max_extent_size = avail; |
| 3929 | ffe_ctl->total_free_space = avail; |
| 3930 | } |
| 3931 | ret = 1; |
| 3932 | goto out; |
| 3933 | } |
| 3934 | |
| 3935 | if (ffe_ctl->for_treelog && !fs_info->treelog_bg) |
| 3936 | fs_info->treelog_bg = block_group->start; |
| 3937 | |
| 3938 | if (ffe_ctl->for_data_reloc) { |
| 3939 | if (!fs_info->data_reloc_bg) |
| 3940 | fs_info->data_reloc_bg = block_group->start; |
| 3941 | /* |
| 3942 | * Do not allow allocations from this block group, unless it is |
| 3943 | * for data relocation. Compared to increasing the ->ro, setting |
| 3944 | * the ->zoned_data_reloc_ongoing flag still allows nocow |
| 3945 | * writers to come in. See btrfs_inc_nocow_writers(). |
| 3946 | * |
| 3947 | * We need to disable an allocation to avoid an allocation of |
| 3948 | * regular (non-relocation data) extent. With mix of relocation |
| 3949 | * extents and regular extents, we can dispatch WRITE commands |
| 3950 | * (for relocation extents) and ZONE APPEND commands (for |
| 3951 | * regular extents) at the same time to the same zone, which |
| 3952 | * easily break the write pointer. |
| 3953 | * |
| 3954 | * Also, this flag avoids this block group to be zone finished. |
| 3955 | */ |
| 3956 | set_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags); |
| 3957 | } |
| 3958 | |
| 3959 | ffe_ctl->found_offset = start + block_group->alloc_offset; |
| 3960 | block_group->alloc_offset += num_bytes; |
| 3961 | spin_lock(&ctl->tree_lock); |
| 3962 | ctl->free_space -= num_bytes; |
| 3963 | spin_unlock(&ctl->tree_lock); |
| 3964 | |
| 3965 | /* |
| 3966 | * We do not check if found_offset is aligned to stripesize. The |
| 3967 | * address is anyway rewritten when using zone append writing. |
| 3968 | */ |
| 3969 | |
| 3970 | ffe_ctl->search_start = ffe_ctl->found_offset; |
| 3971 | |
| 3972 | out: |
| 3973 | if (ret && ffe_ctl->for_treelog) |
| 3974 | fs_info->treelog_bg = 0; |
| 3975 | if (ret && ffe_ctl->for_data_reloc) |
| 3976 | fs_info->data_reloc_bg = 0; |
| 3977 | spin_unlock(&fs_info->relocation_bg_lock); |
| 3978 | spin_unlock(&fs_info->treelog_bg_lock); |
| 3979 | spin_unlock(&block_group->lock); |
| 3980 | spin_unlock(&space_info->lock); |
| 3981 | return ret; |
| 3982 | } |
| 3983 | |
| 3984 | static int do_allocation(struct btrfs_block_group *block_group, |
| 3985 | struct find_free_extent_ctl *ffe_ctl, |
| 3986 | struct btrfs_block_group **bg_ret) |
| 3987 | { |
| 3988 | switch (ffe_ctl->policy) { |
| 3989 | case BTRFS_EXTENT_ALLOC_CLUSTERED: |
| 3990 | return do_allocation_clustered(block_group, ffe_ctl, bg_ret); |
| 3991 | case BTRFS_EXTENT_ALLOC_ZONED: |
| 3992 | return do_allocation_zoned(block_group, ffe_ctl, bg_ret); |
| 3993 | default: |
| 3994 | BUG(); |
| 3995 | } |
| 3996 | } |
| 3997 | |
| 3998 | static void release_block_group(struct btrfs_block_group *block_group, |
| 3999 | struct find_free_extent_ctl *ffe_ctl, |
| 4000 | int delalloc) |
| 4001 | { |
| 4002 | switch (ffe_ctl->policy) { |
| 4003 | case BTRFS_EXTENT_ALLOC_CLUSTERED: |
| 4004 | ffe_ctl->retry_uncached = false; |
| 4005 | break; |
| 4006 | case BTRFS_EXTENT_ALLOC_ZONED: |
| 4007 | /* Nothing to do */ |
| 4008 | break; |
| 4009 | default: |
| 4010 | BUG(); |
| 4011 | } |
| 4012 | |
| 4013 | BUG_ON(btrfs_bg_flags_to_raid_index(block_group->flags) != |
| 4014 | ffe_ctl->index); |
| 4015 | btrfs_release_block_group(block_group, delalloc); |
| 4016 | } |
| 4017 | |
| 4018 | static void found_extent_clustered(struct find_free_extent_ctl *ffe_ctl, |
| 4019 | struct btrfs_key *ins) |
| 4020 | { |
| 4021 | struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr; |
| 4022 | |
| 4023 | if (!ffe_ctl->use_cluster && last_ptr) { |
| 4024 | spin_lock(&last_ptr->lock); |
| 4025 | last_ptr->window_start = ins->objectid; |
| 4026 | spin_unlock(&last_ptr->lock); |
| 4027 | } |
| 4028 | } |
| 4029 | |
| 4030 | static void found_extent(struct find_free_extent_ctl *ffe_ctl, |
| 4031 | struct btrfs_key *ins) |
| 4032 | { |
| 4033 | switch (ffe_ctl->policy) { |
| 4034 | case BTRFS_EXTENT_ALLOC_CLUSTERED: |
| 4035 | found_extent_clustered(ffe_ctl, ins); |
| 4036 | break; |
| 4037 | case BTRFS_EXTENT_ALLOC_ZONED: |
| 4038 | /* Nothing to do */ |
| 4039 | break; |
| 4040 | default: |
| 4041 | BUG(); |
| 4042 | } |
| 4043 | } |
| 4044 | |
| 4045 | static int can_allocate_chunk_zoned(struct btrfs_fs_info *fs_info, |
| 4046 | struct find_free_extent_ctl *ffe_ctl) |
| 4047 | { |
| 4048 | /* Block group's activeness is not a requirement for METADATA block groups. */ |
| 4049 | if (!(ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA)) |
| 4050 | return 0; |
| 4051 | |
| 4052 | /* If we can activate new zone, just allocate a chunk and use it */ |
| 4053 | if (btrfs_can_activate_zone(fs_info->fs_devices, ffe_ctl->flags)) |
| 4054 | return 0; |
| 4055 | |
| 4056 | /* |
| 4057 | * We already reached the max active zones. Try to finish one block |
| 4058 | * group to make a room for a new block group. This is only possible |
| 4059 | * for a data block group because btrfs_zone_finish() may need to wait |
| 4060 | * for a running transaction which can cause a deadlock for metadata |
| 4061 | * allocation. |
| 4062 | */ |
| 4063 | if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA) { |
| 4064 | int ret = btrfs_zone_finish_one_bg(fs_info); |
| 4065 | |
| 4066 | if (ret == 1) |
| 4067 | return 0; |
| 4068 | else if (ret < 0) |
| 4069 | return ret; |
| 4070 | } |
| 4071 | |
| 4072 | /* |
| 4073 | * If we have enough free space left in an already active block group |
| 4074 | * and we can't activate any other zone now, do not allow allocating a |
| 4075 | * new chunk and let find_free_extent() retry with a smaller size. |
| 4076 | */ |
| 4077 | if (ffe_ctl->max_extent_size >= ffe_ctl->min_alloc_size) |
| 4078 | return -ENOSPC; |
| 4079 | |
| 4080 | /* |
| 4081 | * Even min_alloc_size is not left in any block groups. Since we cannot |
| 4082 | * activate a new block group, allocating it may not help. Let's tell a |
| 4083 | * caller to try again and hope it progress something by writing some |
| 4084 | * parts of the region. That is only possible for data block groups, |
| 4085 | * where a part of the region can be written. |
| 4086 | */ |
| 4087 | if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA) |
| 4088 | return -EAGAIN; |
| 4089 | |
| 4090 | /* |
| 4091 | * We cannot activate a new block group and no enough space left in any |
| 4092 | * block groups. So, allocating a new block group may not help. But, |
| 4093 | * there is nothing to do anyway, so let's go with it. |
| 4094 | */ |
| 4095 | return 0; |
| 4096 | } |
| 4097 | |
| 4098 | static int can_allocate_chunk(struct btrfs_fs_info *fs_info, |
| 4099 | struct find_free_extent_ctl *ffe_ctl) |
| 4100 | { |
| 4101 | switch (ffe_ctl->policy) { |
| 4102 | case BTRFS_EXTENT_ALLOC_CLUSTERED: |
| 4103 | return 0; |
| 4104 | case BTRFS_EXTENT_ALLOC_ZONED: |
| 4105 | return can_allocate_chunk_zoned(fs_info, ffe_ctl); |
| 4106 | default: |
| 4107 | BUG(); |
| 4108 | } |
| 4109 | } |
| 4110 | |
| 4111 | /* |
| 4112 | * Return >0 means caller needs to re-search for free extent |
| 4113 | * Return 0 means we have the needed free extent. |
| 4114 | * Return <0 means we failed to locate any free extent. |
| 4115 | */ |
| 4116 | static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info, |
| 4117 | struct btrfs_key *ins, |
| 4118 | struct find_free_extent_ctl *ffe_ctl, |
| 4119 | bool full_search) |
| 4120 | { |
| 4121 | struct btrfs_root *root = fs_info->chunk_root; |
| 4122 | int ret; |
| 4123 | |
| 4124 | if ((ffe_ctl->loop == LOOP_CACHING_NOWAIT) && |
| 4125 | ffe_ctl->have_caching_bg && !ffe_ctl->orig_have_caching_bg) |
| 4126 | ffe_ctl->orig_have_caching_bg = true; |
| 4127 | |
| 4128 | if (ins->objectid) { |
| 4129 | found_extent(ffe_ctl, ins); |
| 4130 | return 0; |
| 4131 | } |
| 4132 | |
| 4133 | if (ffe_ctl->loop >= LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg) |
| 4134 | return 1; |
| 4135 | |
| 4136 | ffe_ctl->index++; |
| 4137 | if (ffe_ctl->index < BTRFS_NR_RAID_TYPES) |
| 4138 | return 1; |
| 4139 | |
| 4140 | /* See the comments for btrfs_loop_type for an explanation of the phases. */ |
| 4141 | if (ffe_ctl->loop < LOOP_NO_EMPTY_SIZE) { |
| 4142 | ffe_ctl->index = 0; |
| 4143 | /* |
| 4144 | * We want to skip the LOOP_CACHING_WAIT step if we don't have |
| 4145 | * any uncached bgs and we've already done a full search |
| 4146 | * through. |
| 4147 | */ |
| 4148 | if (ffe_ctl->loop == LOOP_CACHING_NOWAIT && |
| 4149 | (!ffe_ctl->orig_have_caching_bg && full_search)) |
| 4150 | ffe_ctl->loop++; |
| 4151 | ffe_ctl->loop++; |
| 4152 | |
| 4153 | if (ffe_ctl->loop == LOOP_ALLOC_CHUNK) { |
| 4154 | struct btrfs_trans_handle *trans; |
| 4155 | int exist = 0; |
| 4156 | |
| 4157 | /* Check if allocation policy allows to create a new chunk */ |
| 4158 | ret = can_allocate_chunk(fs_info, ffe_ctl); |
| 4159 | if (ret) |
| 4160 | return ret; |
| 4161 | |
| 4162 | trans = current->journal_info; |
| 4163 | if (trans) |
| 4164 | exist = 1; |
| 4165 | else |
| 4166 | trans = btrfs_join_transaction(root); |
| 4167 | |
| 4168 | if (IS_ERR(trans)) { |
| 4169 | ret = PTR_ERR(trans); |
| 4170 | return ret; |
| 4171 | } |
| 4172 | |
| 4173 | ret = btrfs_chunk_alloc(trans, ffe_ctl->flags, |
| 4174 | CHUNK_ALLOC_FORCE_FOR_EXTENT); |
| 4175 | |
| 4176 | /* Do not bail out on ENOSPC since we can do more. */ |
| 4177 | if (ret == -ENOSPC) { |
| 4178 | ret = 0; |
| 4179 | ffe_ctl->loop++; |
| 4180 | } |
| 4181 | else if (ret < 0) |
| 4182 | btrfs_abort_transaction(trans, ret); |
| 4183 | else |
| 4184 | ret = 0; |
| 4185 | if (!exist) |
| 4186 | btrfs_end_transaction(trans); |
| 4187 | if (ret) |
| 4188 | return ret; |
| 4189 | } |
| 4190 | |
| 4191 | if (ffe_ctl->loop == LOOP_NO_EMPTY_SIZE) { |
| 4192 | if (ffe_ctl->policy != BTRFS_EXTENT_ALLOC_CLUSTERED) |
| 4193 | return -ENOSPC; |
| 4194 | |
| 4195 | /* |
| 4196 | * Don't loop again if we already have no empty_size and |
| 4197 | * no empty_cluster. |
| 4198 | */ |
| 4199 | if (ffe_ctl->empty_size == 0 && |
| 4200 | ffe_ctl->empty_cluster == 0) |
| 4201 | return -ENOSPC; |
| 4202 | ffe_ctl->empty_size = 0; |
| 4203 | ffe_ctl->empty_cluster = 0; |
| 4204 | } |
| 4205 | return 1; |
| 4206 | } |
| 4207 | return -ENOSPC; |
| 4208 | } |
| 4209 | |
| 4210 | static bool find_free_extent_check_size_class(struct find_free_extent_ctl *ffe_ctl, |
| 4211 | struct btrfs_block_group *bg) |
| 4212 | { |
| 4213 | if (ffe_ctl->policy == BTRFS_EXTENT_ALLOC_ZONED) |
| 4214 | return true; |
| 4215 | if (!btrfs_block_group_should_use_size_class(bg)) |
| 4216 | return true; |
| 4217 | if (ffe_ctl->loop >= LOOP_WRONG_SIZE_CLASS) |
| 4218 | return true; |
| 4219 | if (ffe_ctl->loop >= LOOP_UNSET_SIZE_CLASS && |
| 4220 | bg->size_class == BTRFS_BG_SZ_NONE) |
| 4221 | return true; |
| 4222 | return ffe_ctl->size_class == bg->size_class; |
| 4223 | } |
| 4224 | |
| 4225 | static int prepare_allocation_clustered(struct btrfs_fs_info *fs_info, |
| 4226 | struct find_free_extent_ctl *ffe_ctl, |
| 4227 | struct btrfs_space_info *space_info, |
| 4228 | struct btrfs_key *ins) |
| 4229 | { |
| 4230 | /* |
| 4231 | * If our free space is heavily fragmented we may not be able to make |
| 4232 | * big contiguous allocations, so instead of doing the expensive search |
| 4233 | * for free space, simply return ENOSPC with our max_extent_size so we |
| 4234 | * can go ahead and search for a more manageable chunk. |
| 4235 | * |
| 4236 | * If our max_extent_size is large enough for our allocation simply |
| 4237 | * disable clustering since we will likely not be able to find enough |
| 4238 | * space to create a cluster and induce latency trying. |
| 4239 | */ |
| 4240 | if (space_info->max_extent_size) { |
| 4241 | spin_lock(&space_info->lock); |
| 4242 | if (space_info->max_extent_size && |
| 4243 | ffe_ctl->num_bytes > space_info->max_extent_size) { |
| 4244 | ins->offset = space_info->max_extent_size; |
| 4245 | spin_unlock(&space_info->lock); |
| 4246 | return -ENOSPC; |
| 4247 | } else if (space_info->max_extent_size) { |
| 4248 | ffe_ctl->use_cluster = false; |
| 4249 | } |
| 4250 | spin_unlock(&space_info->lock); |
| 4251 | } |
| 4252 | |
| 4253 | ffe_ctl->last_ptr = fetch_cluster_info(fs_info, space_info, |
| 4254 | &ffe_ctl->empty_cluster); |
| 4255 | if (ffe_ctl->last_ptr) { |
| 4256 | struct btrfs_free_cluster *last_ptr = ffe_ctl->last_ptr; |
| 4257 | |
| 4258 | spin_lock(&last_ptr->lock); |
| 4259 | if (last_ptr->block_group) |
| 4260 | ffe_ctl->hint_byte = last_ptr->window_start; |
| 4261 | if (last_ptr->fragmented) { |
| 4262 | /* |
| 4263 | * We still set window_start so we can keep track of the |
| 4264 | * last place we found an allocation to try and save |
| 4265 | * some time. |
| 4266 | */ |
| 4267 | ffe_ctl->hint_byte = last_ptr->window_start; |
| 4268 | ffe_ctl->use_cluster = false; |
| 4269 | } |
| 4270 | spin_unlock(&last_ptr->lock); |
| 4271 | } |
| 4272 | |
| 4273 | return 0; |
| 4274 | } |
| 4275 | |
| 4276 | static int prepare_allocation_zoned(struct btrfs_fs_info *fs_info, |
| 4277 | struct find_free_extent_ctl *ffe_ctl) |
| 4278 | { |
| 4279 | if (ffe_ctl->for_treelog) { |
| 4280 | spin_lock(&fs_info->treelog_bg_lock); |
| 4281 | if (fs_info->treelog_bg) |
| 4282 | ffe_ctl->hint_byte = fs_info->treelog_bg; |
| 4283 | spin_unlock(&fs_info->treelog_bg_lock); |
| 4284 | } else if (ffe_ctl->for_data_reloc) { |
| 4285 | spin_lock(&fs_info->relocation_bg_lock); |
| 4286 | if (fs_info->data_reloc_bg) |
| 4287 | ffe_ctl->hint_byte = fs_info->data_reloc_bg; |
| 4288 | spin_unlock(&fs_info->relocation_bg_lock); |
| 4289 | } else if (ffe_ctl->flags & BTRFS_BLOCK_GROUP_DATA) { |
| 4290 | struct btrfs_block_group *block_group; |
| 4291 | |
| 4292 | spin_lock(&fs_info->zone_active_bgs_lock); |
| 4293 | list_for_each_entry(block_group, &fs_info->zone_active_bgs, active_bg_list) { |
| 4294 | /* |
| 4295 | * No lock is OK here because avail is monotinically |
| 4296 | * decreasing, and this is just a hint. |
| 4297 | */ |
| 4298 | u64 avail = block_group->zone_capacity - block_group->alloc_offset; |
| 4299 | |
| 4300 | if (block_group_bits(block_group, ffe_ctl->flags) && |
| 4301 | avail >= ffe_ctl->num_bytes) { |
| 4302 | ffe_ctl->hint_byte = block_group->start; |
| 4303 | break; |
| 4304 | } |
| 4305 | } |
| 4306 | spin_unlock(&fs_info->zone_active_bgs_lock); |
| 4307 | } |
| 4308 | |
| 4309 | return 0; |
| 4310 | } |
| 4311 | |
| 4312 | static int prepare_allocation(struct btrfs_fs_info *fs_info, |
| 4313 | struct find_free_extent_ctl *ffe_ctl, |
| 4314 | struct btrfs_space_info *space_info, |
| 4315 | struct btrfs_key *ins) |
| 4316 | { |
| 4317 | switch (ffe_ctl->policy) { |
| 4318 | case BTRFS_EXTENT_ALLOC_CLUSTERED: |
| 4319 | return prepare_allocation_clustered(fs_info, ffe_ctl, |
| 4320 | space_info, ins); |
| 4321 | case BTRFS_EXTENT_ALLOC_ZONED: |
| 4322 | return prepare_allocation_zoned(fs_info, ffe_ctl); |
| 4323 | default: |
| 4324 | BUG(); |
| 4325 | } |
| 4326 | } |
| 4327 | |
| 4328 | /* |
| 4329 | * walks the btree of allocated extents and find a hole of a given size. |
| 4330 | * The key ins is changed to record the hole: |
| 4331 | * ins->objectid == start position |
| 4332 | * ins->flags = BTRFS_EXTENT_ITEM_KEY |
| 4333 | * ins->offset == the size of the hole. |
| 4334 | * Any available blocks before search_start are skipped. |
| 4335 | * |
| 4336 | * If there is no suitable free space, we will record the max size of |
| 4337 | * the free space extent currently. |
| 4338 | * |
| 4339 | * The overall logic and call chain: |
| 4340 | * |
| 4341 | * find_free_extent() |
| 4342 | * |- Iterate through all block groups |
| 4343 | * | |- Get a valid block group |
| 4344 | * | |- Try to do clustered allocation in that block group |
| 4345 | * | |- Try to do unclustered allocation in that block group |
| 4346 | * | |- Check if the result is valid |
| 4347 | * | | |- If valid, then exit |
| 4348 | * | |- Jump to next block group |
| 4349 | * | |
| 4350 | * |- Push harder to find free extents |
| 4351 | * |- If not found, re-iterate all block groups |
| 4352 | */ |
| 4353 | static noinline int find_free_extent(struct btrfs_root *root, |
| 4354 | struct btrfs_key *ins, |
| 4355 | struct find_free_extent_ctl *ffe_ctl) |
| 4356 | { |
| 4357 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 4358 | int ret = 0; |
| 4359 | int cache_block_group_error = 0; |
| 4360 | struct btrfs_block_group *block_group = NULL; |
| 4361 | struct btrfs_space_info *space_info; |
| 4362 | bool full_search = false; |
| 4363 | |
| 4364 | WARN_ON(ffe_ctl->num_bytes < fs_info->sectorsize); |
| 4365 | |
| 4366 | ffe_ctl->search_start = 0; |
| 4367 | /* For clustered allocation */ |
| 4368 | ffe_ctl->empty_cluster = 0; |
| 4369 | ffe_ctl->last_ptr = NULL; |
| 4370 | ffe_ctl->use_cluster = true; |
| 4371 | ffe_ctl->have_caching_bg = false; |
| 4372 | ffe_ctl->orig_have_caching_bg = false; |
| 4373 | ffe_ctl->index = btrfs_bg_flags_to_raid_index(ffe_ctl->flags); |
| 4374 | ffe_ctl->loop = 0; |
| 4375 | ffe_ctl->retry_uncached = false; |
| 4376 | ffe_ctl->cached = 0; |
| 4377 | ffe_ctl->max_extent_size = 0; |
| 4378 | ffe_ctl->total_free_space = 0; |
| 4379 | ffe_ctl->found_offset = 0; |
| 4380 | ffe_ctl->policy = BTRFS_EXTENT_ALLOC_CLUSTERED; |
| 4381 | ffe_ctl->size_class = btrfs_calc_block_group_size_class(ffe_ctl->num_bytes); |
| 4382 | |
| 4383 | if (btrfs_is_zoned(fs_info)) |
| 4384 | ffe_ctl->policy = BTRFS_EXTENT_ALLOC_ZONED; |
| 4385 | |
| 4386 | ins->type = BTRFS_EXTENT_ITEM_KEY; |
| 4387 | ins->objectid = 0; |
| 4388 | ins->offset = 0; |
| 4389 | |
| 4390 | trace_find_free_extent(root, ffe_ctl); |
| 4391 | |
| 4392 | space_info = btrfs_find_space_info(fs_info, ffe_ctl->flags); |
| 4393 | if (!space_info) { |
| 4394 | btrfs_err(fs_info, "No space info for %llu", ffe_ctl->flags); |
| 4395 | return -ENOSPC; |
| 4396 | } |
| 4397 | |
| 4398 | ret = prepare_allocation(fs_info, ffe_ctl, space_info, ins); |
| 4399 | if (ret < 0) |
| 4400 | return ret; |
| 4401 | |
| 4402 | ffe_ctl->search_start = max(ffe_ctl->search_start, |
| 4403 | first_logical_byte(fs_info)); |
| 4404 | ffe_ctl->search_start = max(ffe_ctl->search_start, ffe_ctl->hint_byte); |
| 4405 | if (ffe_ctl->search_start == ffe_ctl->hint_byte) { |
| 4406 | block_group = btrfs_lookup_block_group(fs_info, |
| 4407 | ffe_ctl->search_start); |
| 4408 | /* |
| 4409 | * we don't want to use the block group if it doesn't match our |
| 4410 | * allocation bits, or if its not cached. |
| 4411 | * |
| 4412 | * However if we are re-searching with an ideal block group |
| 4413 | * picked out then we don't care that the block group is cached. |
| 4414 | */ |
| 4415 | if (block_group && block_group_bits(block_group, ffe_ctl->flags) && |
| 4416 | block_group->cached != BTRFS_CACHE_NO) { |
| 4417 | down_read(&space_info->groups_sem); |
| 4418 | if (list_empty(&block_group->list) || |
| 4419 | block_group->ro) { |
| 4420 | /* |
| 4421 | * someone is removing this block group, |
| 4422 | * we can't jump into the have_block_group |
| 4423 | * target because our list pointers are not |
| 4424 | * valid |
| 4425 | */ |
| 4426 | btrfs_put_block_group(block_group); |
| 4427 | up_read(&space_info->groups_sem); |
| 4428 | } else { |
| 4429 | ffe_ctl->index = btrfs_bg_flags_to_raid_index( |
| 4430 | block_group->flags); |
| 4431 | btrfs_lock_block_group(block_group, |
| 4432 | ffe_ctl->delalloc); |
| 4433 | ffe_ctl->hinted = true; |
| 4434 | goto have_block_group; |
| 4435 | } |
| 4436 | } else if (block_group) { |
| 4437 | btrfs_put_block_group(block_group); |
| 4438 | } |
| 4439 | } |
| 4440 | search: |
| 4441 | trace_find_free_extent_search_loop(root, ffe_ctl); |
| 4442 | ffe_ctl->have_caching_bg = false; |
| 4443 | if (ffe_ctl->index == btrfs_bg_flags_to_raid_index(ffe_ctl->flags) || |
| 4444 | ffe_ctl->index == 0) |
| 4445 | full_search = true; |
| 4446 | down_read(&space_info->groups_sem); |
| 4447 | list_for_each_entry(block_group, |
| 4448 | &space_info->block_groups[ffe_ctl->index], list) { |
| 4449 | struct btrfs_block_group *bg_ret; |
| 4450 | |
| 4451 | ffe_ctl->hinted = false; |
| 4452 | /* If the block group is read-only, we can skip it entirely. */ |
| 4453 | if (unlikely(block_group->ro)) { |
| 4454 | if (ffe_ctl->for_treelog) |
| 4455 | btrfs_clear_treelog_bg(block_group); |
| 4456 | if (ffe_ctl->for_data_reloc) |
| 4457 | btrfs_clear_data_reloc_bg(block_group); |
| 4458 | continue; |
| 4459 | } |
| 4460 | |
| 4461 | btrfs_grab_block_group(block_group, ffe_ctl->delalloc); |
| 4462 | ffe_ctl->search_start = block_group->start; |
| 4463 | |
| 4464 | /* |
| 4465 | * this can happen if we end up cycling through all the |
| 4466 | * raid types, but we want to make sure we only allocate |
| 4467 | * for the proper type. |
| 4468 | */ |
| 4469 | if (!block_group_bits(block_group, ffe_ctl->flags)) { |
| 4470 | u64 extra = BTRFS_BLOCK_GROUP_DUP | |
| 4471 | BTRFS_BLOCK_GROUP_RAID1_MASK | |
| 4472 | BTRFS_BLOCK_GROUP_RAID56_MASK | |
| 4473 | BTRFS_BLOCK_GROUP_RAID10; |
| 4474 | |
| 4475 | /* |
| 4476 | * if they asked for extra copies and this block group |
| 4477 | * doesn't provide them, bail. This does allow us to |
| 4478 | * fill raid0 from raid1. |
| 4479 | */ |
| 4480 | if ((ffe_ctl->flags & extra) && !(block_group->flags & extra)) |
| 4481 | goto loop; |
| 4482 | |
| 4483 | /* |
| 4484 | * This block group has different flags than we want. |
| 4485 | * It's possible that we have MIXED_GROUP flag but no |
| 4486 | * block group is mixed. Just skip such block group. |
| 4487 | */ |
| 4488 | btrfs_release_block_group(block_group, ffe_ctl->delalloc); |
| 4489 | continue; |
| 4490 | } |
| 4491 | |
| 4492 | have_block_group: |
| 4493 | trace_find_free_extent_have_block_group(root, ffe_ctl, block_group); |
| 4494 | ffe_ctl->cached = btrfs_block_group_done(block_group); |
| 4495 | if (unlikely(!ffe_ctl->cached)) { |
| 4496 | ffe_ctl->have_caching_bg = true; |
| 4497 | ret = btrfs_cache_block_group(block_group, false); |
| 4498 | |
| 4499 | /* |
| 4500 | * If we get ENOMEM here or something else we want to |
| 4501 | * try other block groups, because it may not be fatal. |
| 4502 | * However if we can't find anything else we need to |
| 4503 | * save our return here so that we return the actual |
| 4504 | * error that caused problems, not ENOSPC. |
| 4505 | */ |
| 4506 | if (ret < 0) { |
| 4507 | if (!cache_block_group_error) |
| 4508 | cache_block_group_error = ret; |
| 4509 | ret = 0; |
| 4510 | goto loop; |
| 4511 | } |
| 4512 | ret = 0; |
| 4513 | } |
| 4514 | |
| 4515 | if (unlikely(block_group->cached == BTRFS_CACHE_ERROR)) { |
| 4516 | if (!cache_block_group_error) |
| 4517 | cache_block_group_error = -EIO; |
| 4518 | goto loop; |
| 4519 | } |
| 4520 | |
| 4521 | if (!find_free_extent_check_size_class(ffe_ctl, block_group)) |
| 4522 | goto loop; |
| 4523 | |
| 4524 | bg_ret = NULL; |
| 4525 | ret = do_allocation(block_group, ffe_ctl, &bg_ret); |
| 4526 | if (ret > 0) |
| 4527 | goto loop; |
| 4528 | |
| 4529 | if (bg_ret && bg_ret != block_group) { |
| 4530 | btrfs_release_block_group(block_group, ffe_ctl->delalloc); |
| 4531 | block_group = bg_ret; |
| 4532 | } |
| 4533 | |
| 4534 | /* Checks */ |
| 4535 | ffe_ctl->search_start = round_up(ffe_ctl->found_offset, |
| 4536 | fs_info->stripesize); |
| 4537 | |
| 4538 | /* move on to the next group */ |
| 4539 | if (ffe_ctl->search_start + ffe_ctl->num_bytes > |
| 4540 | block_group->start + block_group->length) { |
| 4541 | btrfs_add_free_space_unused(block_group, |
| 4542 | ffe_ctl->found_offset, |
| 4543 | ffe_ctl->num_bytes); |
| 4544 | goto loop; |
| 4545 | } |
| 4546 | |
| 4547 | if (ffe_ctl->found_offset < ffe_ctl->search_start) |
| 4548 | btrfs_add_free_space_unused(block_group, |
| 4549 | ffe_ctl->found_offset, |
| 4550 | ffe_ctl->search_start - ffe_ctl->found_offset); |
| 4551 | |
| 4552 | ret = btrfs_add_reserved_bytes(block_group, ffe_ctl->ram_bytes, |
| 4553 | ffe_ctl->num_bytes, |
| 4554 | ffe_ctl->delalloc, |
| 4555 | ffe_ctl->loop >= LOOP_WRONG_SIZE_CLASS); |
| 4556 | if (ret == -EAGAIN) { |
| 4557 | btrfs_add_free_space_unused(block_group, |
| 4558 | ffe_ctl->found_offset, |
| 4559 | ffe_ctl->num_bytes); |
| 4560 | goto loop; |
| 4561 | } |
| 4562 | btrfs_inc_block_group_reservations(block_group); |
| 4563 | |
| 4564 | /* we are all good, lets return */ |
| 4565 | ins->objectid = ffe_ctl->search_start; |
| 4566 | ins->offset = ffe_ctl->num_bytes; |
| 4567 | |
| 4568 | trace_btrfs_reserve_extent(block_group, ffe_ctl); |
| 4569 | btrfs_release_block_group(block_group, ffe_ctl->delalloc); |
| 4570 | break; |
| 4571 | loop: |
| 4572 | if (!ffe_ctl->cached && ffe_ctl->loop > LOOP_CACHING_NOWAIT && |
| 4573 | !ffe_ctl->retry_uncached) { |
| 4574 | ffe_ctl->retry_uncached = true; |
| 4575 | btrfs_wait_block_group_cache_progress(block_group, |
| 4576 | ffe_ctl->num_bytes + |
| 4577 | ffe_ctl->empty_cluster + |
| 4578 | ffe_ctl->empty_size); |
| 4579 | goto have_block_group; |
| 4580 | } |
| 4581 | release_block_group(block_group, ffe_ctl, ffe_ctl->delalloc); |
| 4582 | cond_resched(); |
| 4583 | } |
| 4584 | up_read(&space_info->groups_sem); |
| 4585 | |
| 4586 | ret = find_free_extent_update_loop(fs_info, ins, ffe_ctl, full_search); |
| 4587 | if (ret > 0) |
| 4588 | goto search; |
| 4589 | |
| 4590 | if (ret == -ENOSPC && !cache_block_group_error) { |
| 4591 | /* |
| 4592 | * Use ffe_ctl->total_free_space as fallback if we can't find |
| 4593 | * any contiguous hole. |
| 4594 | */ |
| 4595 | if (!ffe_ctl->max_extent_size) |
| 4596 | ffe_ctl->max_extent_size = ffe_ctl->total_free_space; |
| 4597 | spin_lock(&space_info->lock); |
| 4598 | space_info->max_extent_size = ffe_ctl->max_extent_size; |
| 4599 | spin_unlock(&space_info->lock); |
| 4600 | ins->offset = ffe_ctl->max_extent_size; |
| 4601 | } else if (ret == -ENOSPC) { |
| 4602 | ret = cache_block_group_error; |
| 4603 | } |
| 4604 | return ret; |
| 4605 | } |
| 4606 | |
| 4607 | /* |
| 4608 | * Entry point to the extent allocator. Tries to find a hole that is at least |
| 4609 | * as big as @num_bytes. |
| 4610 | * |
| 4611 | * @root - The root that will contain this extent |
| 4612 | * |
| 4613 | * @ram_bytes - The amount of space in ram that @num_bytes take. This |
| 4614 | * is used for accounting purposes. This value differs |
| 4615 | * from @num_bytes only in the case of compressed extents. |
| 4616 | * |
| 4617 | * @num_bytes - Number of bytes to allocate on-disk. |
| 4618 | * |
| 4619 | * @min_alloc_size - Indicates the minimum amount of space that the |
| 4620 | * allocator should try to satisfy. In some cases |
| 4621 | * @num_bytes may be larger than what is required and if |
| 4622 | * the filesystem is fragmented then allocation fails. |
| 4623 | * However, the presence of @min_alloc_size gives a |
| 4624 | * chance to try and satisfy the smaller allocation. |
| 4625 | * |
| 4626 | * @empty_size - A hint that you plan on doing more COW. This is the |
| 4627 | * size in bytes the allocator should try to find free |
| 4628 | * next to the block it returns. This is just a hint and |
| 4629 | * may be ignored by the allocator. |
| 4630 | * |
| 4631 | * @hint_byte - Hint to the allocator to start searching above the byte |
| 4632 | * address passed. It might be ignored. |
| 4633 | * |
| 4634 | * @ins - This key is modified to record the found hole. It will |
| 4635 | * have the following values: |
| 4636 | * ins->objectid == start position |
| 4637 | * ins->flags = BTRFS_EXTENT_ITEM_KEY |
| 4638 | * ins->offset == the size of the hole. |
| 4639 | * |
| 4640 | * @is_data - Boolean flag indicating whether an extent is |
| 4641 | * allocated for data (true) or metadata (false) |
| 4642 | * |
| 4643 | * @delalloc - Boolean flag indicating whether this allocation is for |
| 4644 | * delalloc or not. If 'true' data_rwsem of block groups |
| 4645 | * is going to be acquired. |
| 4646 | * |
| 4647 | * |
| 4648 | * Returns 0 when an allocation succeeded or < 0 when an error occurred. In |
| 4649 | * case -ENOSPC is returned then @ins->offset will contain the size of the |
| 4650 | * largest available hole the allocator managed to find. |
| 4651 | */ |
| 4652 | int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes, |
| 4653 | u64 num_bytes, u64 min_alloc_size, |
| 4654 | u64 empty_size, u64 hint_byte, |
| 4655 | struct btrfs_key *ins, int is_data, int delalloc) |
| 4656 | { |
| 4657 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 4658 | struct find_free_extent_ctl ffe_ctl = {}; |
| 4659 | bool final_tried = num_bytes == min_alloc_size; |
| 4660 | u64 flags; |
| 4661 | int ret; |
| 4662 | bool for_treelog = (btrfs_root_id(root) == BTRFS_TREE_LOG_OBJECTID); |
| 4663 | bool for_data_reloc = (btrfs_is_data_reloc_root(root) && is_data); |
| 4664 | |
| 4665 | flags = get_alloc_profile_by_root(root, is_data); |
| 4666 | again: |
| 4667 | WARN_ON(num_bytes < fs_info->sectorsize); |
| 4668 | |
| 4669 | ffe_ctl.ram_bytes = ram_bytes; |
| 4670 | ffe_ctl.num_bytes = num_bytes; |
| 4671 | ffe_ctl.min_alloc_size = min_alloc_size; |
| 4672 | ffe_ctl.empty_size = empty_size; |
| 4673 | ffe_ctl.flags = flags; |
| 4674 | ffe_ctl.delalloc = delalloc; |
| 4675 | ffe_ctl.hint_byte = hint_byte; |
| 4676 | ffe_ctl.for_treelog = for_treelog; |
| 4677 | ffe_ctl.for_data_reloc = for_data_reloc; |
| 4678 | |
| 4679 | ret = find_free_extent(root, ins, &ffe_ctl); |
| 4680 | if (!ret && !is_data) { |
| 4681 | btrfs_dec_block_group_reservations(fs_info, ins->objectid); |
| 4682 | } else if (ret == -ENOSPC) { |
| 4683 | if (!final_tried && ins->offset) { |
| 4684 | num_bytes = min(num_bytes >> 1, ins->offset); |
| 4685 | num_bytes = round_down(num_bytes, |
| 4686 | fs_info->sectorsize); |
| 4687 | num_bytes = max(num_bytes, min_alloc_size); |
| 4688 | ram_bytes = num_bytes; |
| 4689 | if (num_bytes == min_alloc_size) |
| 4690 | final_tried = true; |
| 4691 | goto again; |
| 4692 | } else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { |
| 4693 | struct btrfs_space_info *sinfo; |
| 4694 | |
| 4695 | sinfo = btrfs_find_space_info(fs_info, flags); |
| 4696 | btrfs_err(fs_info, |
| 4697 | "allocation failed flags %llu, wanted %llu tree-log %d, relocation: %d", |
| 4698 | flags, num_bytes, for_treelog, for_data_reloc); |
| 4699 | if (sinfo) |
| 4700 | btrfs_dump_space_info(fs_info, sinfo, |
| 4701 | num_bytes, 1); |
| 4702 | } |
| 4703 | } |
| 4704 | |
| 4705 | return ret; |
| 4706 | } |
| 4707 | |
| 4708 | int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info, |
| 4709 | u64 start, u64 len, int delalloc) |
| 4710 | { |
| 4711 | struct btrfs_block_group *cache; |
| 4712 | |
| 4713 | cache = btrfs_lookup_block_group(fs_info, start); |
| 4714 | if (!cache) { |
| 4715 | btrfs_err(fs_info, "Unable to find block group for %llu", |
| 4716 | start); |
| 4717 | return -ENOSPC; |
| 4718 | } |
| 4719 | |
| 4720 | btrfs_add_free_space(cache, start, len); |
| 4721 | btrfs_free_reserved_bytes(cache, len, delalloc); |
| 4722 | trace_btrfs_reserved_extent_free(fs_info, start, len); |
| 4723 | |
| 4724 | btrfs_put_block_group(cache); |
| 4725 | return 0; |
| 4726 | } |
| 4727 | |
| 4728 | int btrfs_pin_reserved_extent(struct btrfs_trans_handle *trans, |
| 4729 | const struct extent_buffer *eb) |
| 4730 | { |
| 4731 | struct btrfs_block_group *cache; |
| 4732 | int ret = 0; |
| 4733 | |
| 4734 | cache = btrfs_lookup_block_group(trans->fs_info, eb->start); |
| 4735 | if (!cache) { |
| 4736 | btrfs_err(trans->fs_info, "unable to find block group for %llu", |
| 4737 | eb->start); |
| 4738 | return -ENOSPC; |
| 4739 | } |
| 4740 | |
| 4741 | ret = pin_down_extent(trans, cache, eb->start, eb->len, 1); |
| 4742 | btrfs_put_block_group(cache); |
| 4743 | return ret; |
| 4744 | } |
| 4745 | |
| 4746 | static int alloc_reserved_extent(struct btrfs_trans_handle *trans, u64 bytenr, |
| 4747 | u64 num_bytes) |
| 4748 | { |
| 4749 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 4750 | int ret; |
| 4751 | |
| 4752 | ret = remove_from_free_space_tree(trans, bytenr, num_bytes); |
| 4753 | if (ret) |
| 4754 | return ret; |
| 4755 | |
| 4756 | ret = btrfs_update_block_group(trans, bytenr, num_bytes, true); |
| 4757 | if (ret) { |
| 4758 | ASSERT(!ret); |
| 4759 | btrfs_err(fs_info, "update block group failed for %llu %llu", |
| 4760 | bytenr, num_bytes); |
| 4761 | return ret; |
| 4762 | } |
| 4763 | |
| 4764 | trace_btrfs_reserved_extent_alloc(fs_info, bytenr, num_bytes); |
| 4765 | return 0; |
| 4766 | } |
| 4767 | |
| 4768 | static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, |
| 4769 | u64 parent, u64 root_objectid, |
| 4770 | u64 flags, u64 owner, u64 offset, |
| 4771 | struct btrfs_key *ins, int ref_mod, u64 oref_root) |
| 4772 | { |
| 4773 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 4774 | struct btrfs_root *extent_root; |
| 4775 | int ret; |
| 4776 | struct btrfs_extent_item *extent_item; |
| 4777 | struct btrfs_extent_owner_ref *oref; |
| 4778 | struct btrfs_extent_inline_ref *iref; |
| 4779 | struct btrfs_path *path; |
| 4780 | struct extent_buffer *leaf; |
| 4781 | int type; |
| 4782 | u32 size; |
| 4783 | const bool simple_quota = (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE); |
| 4784 | |
| 4785 | if (parent > 0) |
| 4786 | type = BTRFS_SHARED_DATA_REF_KEY; |
| 4787 | else |
| 4788 | type = BTRFS_EXTENT_DATA_REF_KEY; |
| 4789 | |
| 4790 | size = sizeof(*extent_item); |
| 4791 | if (simple_quota) |
| 4792 | size += btrfs_extent_inline_ref_size(BTRFS_EXTENT_OWNER_REF_KEY); |
| 4793 | size += btrfs_extent_inline_ref_size(type); |
| 4794 | |
| 4795 | path = btrfs_alloc_path(); |
| 4796 | if (!path) |
| 4797 | return -ENOMEM; |
| 4798 | |
| 4799 | extent_root = btrfs_extent_root(fs_info, ins->objectid); |
| 4800 | ret = btrfs_insert_empty_item(trans, extent_root, path, ins, size); |
| 4801 | if (ret) { |
| 4802 | btrfs_free_path(path); |
| 4803 | return ret; |
| 4804 | } |
| 4805 | |
| 4806 | leaf = path->nodes[0]; |
| 4807 | extent_item = btrfs_item_ptr(leaf, path->slots[0], |
| 4808 | struct btrfs_extent_item); |
| 4809 | btrfs_set_extent_refs(leaf, extent_item, ref_mod); |
| 4810 | btrfs_set_extent_generation(leaf, extent_item, trans->transid); |
| 4811 | btrfs_set_extent_flags(leaf, extent_item, |
| 4812 | flags | BTRFS_EXTENT_FLAG_DATA); |
| 4813 | |
| 4814 | iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); |
| 4815 | if (simple_quota) { |
| 4816 | btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_EXTENT_OWNER_REF_KEY); |
| 4817 | oref = (struct btrfs_extent_owner_ref *)(&iref->offset); |
| 4818 | btrfs_set_extent_owner_ref_root_id(leaf, oref, oref_root); |
| 4819 | iref = (struct btrfs_extent_inline_ref *)(oref + 1); |
| 4820 | } |
| 4821 | btrfs_set_extent_inline_ref_type(leaf, iref, type); |
| 4822 | |
| 4823 | if (parent > 0) { |
| 4824 | struct btrfs_shared_data_ref *ref; |
| 4825 | ref = (struct btrfs_shared_data_ref *)(iref + 1); |
| 4826 | btrfs_set_extent_inline_ref_offset(leaf, iref, parent); |
| 4827 | btrfs_set_shared_data_ref_count(leaf, ref, ref_mod); |
| 4828 | } else { |
| 4829 | struct btrfs_extent_data_ref *ref; |
| 4830 | ref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| 4831 | btrfs_set_extent_data_ref_root(leaf, ref, root_objectid); |
| 4832 | btrfs_set_extent_data_ref_objectid(leaf, ref, owner); |
| 4833 | btrfs_set_extent_data_ref_offset(leaf, ref, offset); |
| 4834 | btrfs_set_extent_data_ref_count(leaf, ref, ref_mod); |
| 4835 | } |
| 4836 | |
| 4837 | btrfs_mark_buffer_dirty(trans, path->nodes[0]); |
| 4838 | btrfs_free_path(path); |
| 4839 | |
| 4840 | return alloc_reserved_extent(trans, ins->objectid, ins->offset); |
| 4841 | } |
| 4842 | |
| 4843 | static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, |
| 4844 | struct btrfs_delayed_ref_node *node, |
| 4845 | struct btrfs_delayed_extent_op *extent_op) |
| 4846 | { |
| 4847 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 4848 | struct btrfs_root *extent_root; |
| 4849 | int ret; |
| 4850 | struct btrfs_extent_item *extent_item; |
| 4851 | struct btrfs_key extent_key; |
| 4852 | struct btrfs_tree_block_info *block_info; |
| 4853 | struct btrfs_extent_inline_ref *iref; |
| 4854 | struct btrfs_path *path; |
| 4855 | struct extent_buffer *leaf; |
| 4856 | u32 size = sizeof(*extent_item) + sizeof(*iref); |
| 4857 | const u64 flags = (extent_op ? extent_op->flags_to_set : 0); |
| 4858 | /* The owner of a tree block is the level. */ |
| 4859 | int level = btrfs_delayed_ref_owner(node); |
| 4860 | bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA); |
| 4861 | |
| 4862 | extent_key.objectid = node->bytenr; |
| 4863 | if (skinny_metadata) { |
| 4864 | /* The owner of a tree block is the level. */ |
| 4865 | extent_key.offset = level; |
| 4866 | extent_key.type = BTRFS_METADATA_ITEM_KEY; |
| 4867 | } else { |
| 4868 | extent_key.offset = node->num_bytes; |
| 4869 | extent_key.type = BTRFS_EXTENT_ITEM_KEY; |
| 4870 | size += sizeof(*block_info); |
| 4871 | } |
| 4872 | |
| 4873 | path = btrfs_alloc_path(); |
| 4874 | if (!path) |
| 4875 | return -ENOMEM; |
| 4876 | |
| 4877 | extent_root = btrfs_extent_root(fs_info, extent_key.objectid); |
| 4878 | ret = btrfs_insert_empty_item(trans, extent_root, path, &extent_key, |
| 4879 | size); |
| 4880 | if (ret) { |
| 4881 | btrfs_free_path(path); |
| 4882 | return ret; |
| 4883 | } |
| 4884 | |
| 4885 | leaf = path->nodes[0]; |
| 4886 | extent_item = btrfs_item_ptr(leaf, path->slots[0], |
| 4887 | struct btrfs_extent_item); |
| 4888 | btrfs_set_extent_refs(leaf, extent_item, 1); |
| 4889 | btrfs_set_extent_generation(leaf, extent_item, trans->transid); |
| 4890 | btrfs_set_extent_flags(leaf, extent_item, |
| 4891 | flags | BTRFS_EXTENT_FLAG_TREE_BLOCK); |
| 4892 | |
| 4893 | if (skinny_metadata) { |
| 4894 | iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); |
| 4895 | } else { |
| 4896 | block_info = (struct btrfs_tree_block_info *)(extent_item + 1); |
| 4897 | btrfs_set_tree_block_key(leaf, block_info, &extent_op->key); |
| 4898 | btrfs_set_tree_block_level(leaf, block_info, level); |
| 4899 | iref = (struct btrfs_extent_inline_ref *)(block_info + 1); |
| 4900 | } |
| 4901 | |
| 4902 | if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) { |
| 4903 | btrfs_set_extent_inline_ref_type(leaf, iref, |
| 4904 | BTRFS_SHARED_BLOCK_REF_KEY); |
| 4905 | btrfs_set_extent_inline_ref_offset(leaf, iref, node->parent); |
| 4906 | } else { |
| 4907 | btrfs_set_extent_inline_ref_type(leaf, iref, |
| 4908 | BTRFS_TREE_BLOCK_REF_KEY); |
| 4909 | btrfs_set_extent_inline_ref_offset(leaf, iref, node->ref_root); |
| 4910 | } |
| 4911 | |
| 4912 | btrfs_mark_buffer_dirty(trans, leaf); |
| 4913 | btrfs_free_path(path); |
| 4914 | |
| 4915 | return alloc_reserved_extent(trans, node->bytenr, fs_info->nodesize); |
| 4916 | } |
| 4917 | |
| 4918 | int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans, |
| 4919 | struct btrfs_root *root, u64 owner, |
| 4920 | u64 offset, u64 ram_bytes, |
| 4921 | struct btrfs_key *ins) |
| 4922 | { |
| 4923 | struct btrfs_ref generic_ref = { |
| 4924 | .action = BTRFS_ADD_DELAYED_EXTENT, |
| 4925 | .bytenr = ins->objectid, |
| 4926 | .num_bytes = ins->offset, |
| 4927 | .owning_root = btrfs_root_id(root), |
| 4928 | .ref_root = btrfs_root_id(root), |
| 4929 | }; |
| 4930 | |
| 4931 | ASSERT(generic_ref.ref_root != BTRFS_TREE_LOG_OBJECTID); |
| 4932 | |
| 4933 | if (btrfs_is_data_reloc_root(root) && is_fstree(root->relocation_src_root)) |
| 4934 | generic_ref.owning_root = root->relocation_src_root; |
| 4935 | |
| 4936 | btrfs_init_data_ref(&generic_ref, owner, offset, 0, false); |
| 4937 | btrfs_ref_tree_mod(root->fs_info, &generic_ref); |
| 4938 | |
| 4939 | return btrfs_add_delayed_data_ref(trans, &generic_ref, ram_bytes); |
| 4940 | } |
| 4941 | |
| 4942 | /* |
| 4943 | * this is used by the tree logging recovery code. It records that |
| 4944 | * an extent has been allocated and makes sure to clear the free |
| 4945 | * space cache bits as well |
| 4946 | */ |
| 4947 | int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans, |
| 4948 | u64 root_objectid, u64 owner, u64 offset, |
| 4949 | struct btrfs_key *ins) |
| 4950 | { |
| 4951 | struct btrfs_fs_info *fs_info = trans->fs_info; |
| 4952 | int ret; |
| 4953 | struct btrfs_block_group *block_group; |
| 4954 | struct btrfs_space_info *space_info; |
| 4955 | struct btrfs_squota_delta delta = { |
| 4956 | .root = root_objectid, |
| 4957 | .num_bytes = ins->offset, |
| 4958 | .generation = trans->transid, |
| 4959 | .is_data = true, |
| 4960 | .is_inc = true, |
| 4961 | }; |
| 4962 | |
| 4963 | /* |
| 4964 | * Mixed block groups will exclude before processing the log so we only |
| 4965 | * need to do the exclude dance if this fs isn't mixed. |
| 4966 | */ |
| 4967 | if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) { |
| 4968 | ret = __exclude_logged_extent(fs_info, ins->objectid, |
| 4969 | ins->offset); |
| 4970 | if (ret) |
| 4971 | return ret; |
| 4972 | } |
| 4973 | |
| 4974 | block_group = btrfs_lookup_block_group(fs_info, ins->objectid); |
| 4975 | if (!block_group) |
| 4976 | return -EINVAL; |
| 4977 | |
| 4978 | space_info = block_group->space_info; |
| 4979 | spin_lock(&space_info->lock); |
| 4980 | spin_lock(&block_group->lock); |
| 4981 | space_info->bytes_reserved += ins->offset; |
| 4982 | block_group->reserved += ins->offset; |
| 4983 | spin_unlock(&block_group->lock); |
| 4984 | spin_unlock(&space_info->lock); |
| 4985 | |
| 4986 | ret = alloc_reserved_file_extent(trans, 0, root_objectid, 0, owner, |
| 4987 | offset, ins, 1, root_objectid); |
| 4988 | if (ret) |
| 4989 | btrfs_pin_extent(trans, ins->objectid, ins->offset, 1); |
| 4990 | ret = btrfs_record_squota_delta(fs_info, &delta); |
| 4991 | btrfs_put_block_group(block_group); |
| 4992 | return ret; |
| 4993 | } |
| 4994 | |
| 4995 | #ifdef CONFIG_BTRFS_DEBUG |
| 4996 | /* |
| 4997 | * Extra safety check in case the extent tree is corrupted and extent allocator |
| 4998 | * chooses to use a tree block which is already used and locked. |
| 4999 | */ |
| 5000 | static bool check_eb_lock_owner(const struct extent_buffer *eb) |
| 5001 | { |
| 5002 | if (eb->lock_owner == current->pid) { |
| 5003 | btrfs_err_rl(eb->fs_info, |
| 5004 | "tree block %llu owner %llu already locked by pid=%d, extent tree corruption detected", |
| 5005 | eb->start, btrfs_header_owner(eb), current->pid); |
| 5006 | return true; |
| 5007 | } |
| 5008 | return false; |
| 5009 | } |
| 5010 | #else |
| 5011 | static bool check_eb_lock_owner(struct extent_buffer *eb) |
| 5012 | { |
| 5013 | return false; |
| 5014 | } |
| 5015 | #endif |
| 5016 | |
| 5017 | static struct extent_buffer * |
| 5018 | btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| 5019 | u64 bytenr, int level, u64 owner, |
| 5020 | enum btrfs_lock_nesting nest) |
| 5021 | { |
| 5022 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 5023 | struct extent_buffer *buf; |
| 5024 | u64 lockdep_owner = owner; |
| 5025 | |
| 5026 | buf = btrfs_find_create_tree_block(fs_info, bytenr, owner, level); |
| 5027 | if (IS_ERR(buf)) |
| 5028 | return buf; |
| 5029 | |
| 5030 | if (check_eb_lock_owner(buf)) { |
| 5031 | free_extent_buffer(buf); |
| 5032 | return ERR_PTR(-EUCLEAN); |
| 5033 | } |
| 5034 | |
| 5035 | /* |
| 5036 | * The reloc trees are just snapshots, so we need them to appear to be |
| 5037 | * just like any other fs tree WRT lockdep. |
| 5038 | * |
| 5039 | * The exception however is in replace_path() in relocation, where we |
| 5040 | * hold the lock on the original fs root and then search for the reloc |
| 5041 | * root. At that point we need to make sure any reloc root buffers are |
| 5042 | * set to the BTRFS_TREE_RELOC_OBJECTID lockdep class in order to make |
| 5043 | * lockdep happy. |
| 5044 | */ |
| 5045 | if (lockdep_owner == BTRFS_TREE_RELOC_OBJECTID && |
| 5046 | !test_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &root->state)) |
| 5047 | lockdep_owner = BTRFS_FS_TREE_OBJECTID; |
| 5048 | |
| 5049 | /* btrfs_clear_buffer_dirty() accesses generation field. */ |
| 5050 | btrfs_set_header_generation(buf, trans->transid); |
| 5051 | |
| 5052 | /* |
| 5053 | * This needs to stay, because we could allocate a freed block from an |
| 5054 | * old tree into a new tree, so we need to make sure this new block is |
| 5055 | * set to the appropriate level and owner. |
| 5056 | */ |
| 5057 | btrfs_set_buffer_lockdep_class(lockdep_owner, buf, level); |
| 5058 | |
| 5059 | btrfs_tree_lock_nested(buf, nest); |
| 5060 | btrfs_clear_buffer_dirty(trans, buf); |
| 5061 | clear_bit(EXTENT_BUFFER_STALE, &buf->bflags); |
| 5062 | clear_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &buf->bflags); |
| 5063 | |
| 5064 | set_extent_buffer_uptodate(buf); |
| 5065 | |
| 5066 | memzero_extent_buffer(buf, 0, sizeof(struct btrfs_header)); |
| 5067 | btrfs_set_header_level(buf, level); |
| 5068 | btrfs_set_header_bytenr(buf, buf->start); |
| 5069 | btrfs_set_header_generation(buf, trans->transid); |
| 5070 | btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV); |
| 5071 | btrfs_set_header_owner(buf, owner); |
| 5072 | write_extent_buffer_fsid(buf, fs_info->fs_devices->metadata_uuid); |
| 5073 | write_extent_buffer_chunk_tree_uuid(buf, fs_info->chunk_tree_uuid); |
| 5074 | if (btrfs_root_id(root) == BTRFS_TREE_LOG_OBJECTID) { |
| 5075 | buf->log_index = root->log_transid % 2; |
| 5076 | /* |
| 5077 | * we allow two log transactions at a time, use different |
| 5078 | * EXTENT bit to differentiate dirty pages. |
| 5079 | */ |
| 5080 | if (buf->log_index == 0) |
| 5081 | set_extent_bit(&root->dirty_log_pages, buf->start, |
| 5082 | buf->start + buf->len - 1, |
| 5083 | EXTENT_DIRTY, NULL); |
| 5084 | else |
| 5085 | set_extent_bit(&root->dirty_log_pages, buf->start, |
| 5086 | buf->start + buf->len - 1, |
| 5087 | EXTENT_NEW, NULL); |
| 5088 | } else { |
| 5089 | buf->log_index = -1; |
| 5090 | set_extent_bit(&trans->transaction->dirty_pages, buf->start, |
| 5091 | buf->start + buf->len - 1, EXTENT_DIRTY, NULL); |
| 5092 | } |
| 5093 | /* this returns a buffer locked for blocking */ |
| 5094 | return buf; |
| 5095 | } |
| 5096 | |
| 5097 | /* |
| 5098 | * finds a free extent and does all the dirty work required for allocation |
| 5099 | * returns the tree buffer or an ERR_PTR on error. |
| 5100 | */ |
| 5101 | struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, |
| 5102 | struct btrfs_root *root, |
| 5103 | u64 parent, u64 root_objectid, |
| 5104 | const struct btrfs_disk_key *key, |
| 5105 | int level, u64 hint, |
| 5106 | u64 empty_size, |
| 5107 | u64 reloc_src_root, |
| 5108 | enum btrfs_lock_nesting nest) |
| 5109 | { |
| 5110 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 5111 | struct btrfs_key ins; |
| 5112 | struct btrfs_block_rsv *block_rsv; |
| 5113 | struct extent_buffer *buf; |
| 5114 | u64 flags = 0; |
| 5115 | int ret; |
| 5116 | u32 blocksize = fs_info->nodesize; |
| 5117 | bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA); |
| 5118 | u64 owning_root; |
| 5119 | |
| 5120 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
| 5121 | if (btrfs_is_testing(fs_info)) { |
| 5122 | buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr, |
| 5123 | level, root_objectid, nest); |
| 5124 | if (!IS_ERR(buf)) |
| 5125 | root->alloc_bytenr += blocksize; |
| 5126 | return buf; |
| 5127 | } |
| 5128 | #endif |
| 5129 | |
| 5130 | block_rsv = btrfs_use_block_rsv(trans, root, blocksize); |
| 5131 | if (IS_ERR(block_rsv)) |
| 5132 | return ERR_CAST(block_rsv); |
| 5133 | |
| 5134 | ret = btrfs_reserve_extent(root, blocksize, blocksize, blocksize, |
| 5135 | empty_size, hint, &ins, 0, 0); |
| 5136 | if (ret) |
| 5137 | goto out_unuse; |
| 5138 | |
| 5139 | buf = btrfs_init_new_buffer(trans, root, ins.objectid, level, |
| 5140 | root_objectid, nest); |
| 5141 | if (IS_ERR(buf)) { |
| 5142 | ret = PTR_ERR(buf); |
| 5143 | goto out_free_reserved; |
| 5144 | } |
| 5145 | owning_root = btrfs_header_owner(buf); |
| 5146 | |
| 5147 | if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) { |
| 5148 | if (parent == 0) |
| 5149 | parent = ins.objectid; |
| 5150 | flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| 5151 | owning_root = reloc_src_root; |
| 5152 | } else |
| 5153 | BUG_ON(parent > 0); |
| 5154 | |
| 5155 | if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { |
| 5156 | struct btrfs_delayed_extent_op *extent_op; |
| 5157 | struct btrfs_ref generic_ref = { |
| 5158 | .action = BTRFS_ADD_DELAYED_EXTENT, |
| 5159 | .bytenr = ins.objectid, |
| 5160 | .num_bytes = ins.offset, |
| 5161 | .parent = parent, |
| 5162 | .owning_root = owning_root, |
| 5163 | .ref_root = root_objectid, |
| 5164 | }; |
| 5165 | |
| 5166 | if (!skinny_metadata || flags != 0) { |
| 5167 | extent_op = btrfs_alloc_delayed_extent_op(); |
| 5168 | if (!extent_op) { |
| 5169 | ret = -ENOMEM; |
| 5170 | goto out_free_buf; |
| 5171 | } |
| 5172 | if (key) |
| 5173 | memcpy(&extent_op->key, key, sizeof(extent_op->key)); |
| 5174 | else |
| 5175 | memset(&extent_op->key, 0, sizeof(extent_op->key)); |
| 5176 | extent_op->flags_to_set = flags; |
| 5177 | extent_op->update_key = (skinny_metadata ? false : true); |
| 5178 | extent_op->update_flags = (flags != 0); |
| 5179 | } else { |
| 5180 | extent_op = NULL; |
| 5181 | } |
| 5182 | |
| 5183 | btrfs_init_tree_ref(&generic_ref, level, btrfs_root_id(root), false); |
| 5184 | btrfs_ref_tree_mod(fs_info, &generic_ref); |
| 5185 | ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, extent_op); |
| 5186 | if (ret) { |
| 5187 | btrfs_free_delayed_extent_op(extent_op); |
| 5188 | goto out_free_buf; |
| 5189 | } |
| 5190 | } |
| 5191 | return buf; |
| 5192 | |
| 5193 | out_free_buf: |
| 5194 | btrfs_tree_unlock(buf); |
| 5195 | free_extent_buffer(buf); |
| 5196 | out_free_reserved: |
| 5197 | btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0); |
| 5198 | out_unuse: |
| 5199 | btrfs_unuse_block_rsv(fs_info, block_rsv, blocksize); |
| 5200 | return ERR_PTR(ret); |
| 5201 | } |
| 5202 | |
| 5203 | struct walk_control { |
| 5204 | u64 refs[BTRFS_MAX_LEVEL]; |
| 5205 | u64 flags[BTRFS_MAX_LEVEL]; |
| 5206 | struct btrfs_key update_progress; |
| 5207 | struct btrfs_key drop_progress; |
| 5208 | int drop_level; |
| 5209 | int stage; |
| 5210 | int level; |
| 5211 | int shared_level; |
| 5212 | int update_ref; |
| 5213 | int keep_locks; |
| 5214 | int reada_slot; |
| 5215 | int reada_count; |
| 5216 | int restarted; |
| 5217 | /* Indicate that extent info needs to be looked up when walking the tree. */ |
| 5218 | int lookup_info; |
| 5219 | }; |
| 5220 | |
| 5221 | /* |
| 5222 | * This is our normal stage. We are traversing blocks the current snapshot owns |
| 5223 | * and we are dropping any of our references to any children we are able to, and |
| 5224 | * then freeing the block once we've processed all of the children. |
| 5225 | */ |
| 5226 | #define DROP_REFERENCE 1 |
| 5227 | |
| 5228 | /* |
| 5229 | * We enter this stage when we have to walk into a child block (meaning we can't |
| 5230 | * simply drop our reference to it from our current parent node) and there are |
| 5231 | * more than one reference on it. If we are the owner of any of the children |
| 5232 | * blocks from the current parent node then we have to do the FULL_BACKREF dance |
| 5233 | * on them in order to drop our normal ref and add the shared ref. |
| 5234 | */ |
| 5235 | #define UPDATE_BACKREF 2 |
| 5236 | |
| 5237 | /* |
| 5238 | * Decide if we need to walk down into this node to adjust the references. |
| 5239 | * |
| 5240 | * @root: the root we are currently deleting |
| 5241 | * @wc: the walk control for this deletion |
| 5242 | * @eb: the parent eb that we're currently visiting |
| 5243 | * @refs: the number of refs for wc->level - 1 |
| 5244 | * @flags: the flags for wc->level - 1 |
| 5245 | * @slot: the slot in the eb that we're currently checking |
| 5246 | * |
| 5247 | * This is meant to be called when we're evaluating if a node we point to at |
| 5248 | * wc->level should be read and walked into, or if we can simply delete our |
| 5249 | * reference to it. We return true if we should walk into the node, false if we |
| 5250 | * can skip it. |
| 5251 | * |
| 5252 | * We have assertions in here to make sure this is called correctly. We assume |
| 5253 | * that sanity checking on the blocks read to this point has been done, so any |
| 5254 | * corrupted file systems must have been caught before calling this function. |
| 5255 | */ |
| 5256 | static bool visit_node_for_delete(struct btrfs_root *root, struct walk_control *wc, |
| 5257 | struct extent_buffer *eb, u64 refs, u64 flags, int slot) |
| 5258 | { |
| 5259 | struct btrfs_key key; |
| 5260 | u64 generation; |
| 5261 | int level = wc->level; |
| 5262 | |
| 5263 | ASSERT(level > 0); |
| 5264 | ASSERT(wc->refs[level - 1] > 0); |
| 5265 | |
| 5266 | /* |
| 5267 | * The update backref stage we only want to skip if we already have |
| 5268 | * FULL_BACKREF set, otherwise we need to read. |
| 5269 | */ |
| 5270 | if (wc->stage == UPDATE_BACKREF) { |
| 5271 | if (level == 1 && flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| 5272 | return false; |
| 5273 | return true; |
| 5274 | } |
| 5275 | |
| 5276 | /* |
| 5277 | * We're the last ref on this block, we must walk into it and process |
| 5278 | * any refs it's pointing at. |
| 5279 | */ |
| 5280 | if (wc->refs[level - 1] == 1) |
| 5281 | return true; |
| 5282 | |
| 5283 | /* |
| 5284 | * If we're already FULL_BACKREF then we know we can just drop our |
| 5285 | * current reference. |
| 5286 | */ |
| 5287 | if (level == 1 && flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| 5288 | return false; |
| 5289 | |
| 5290 | /* |
| 5291 | * This block is older than our creation generation, we can drop our |
| 5292 | * reference to it. |
| 5293 | */ |
| 5294 | generation = btrfs_node_ptr_generation(eb, slot); |
| 5295 | if (!wc->update_ref || generation <= root->root_key.offset) |
| 5296 | return false; |
| 5297 | |
| 5298 | /* |
| 5299 | * This block was processed from a previous snapshot deletion run, we |
| 5300 | * can skip it. |
| 5301 | */ |
| 5302 | btrfs_node_key_to_cpu(eb, &key, slot); |
| 5303 | if (btrfs_comp_cpu_keys(&key, &wc->update_progress) < 0) |
| 5304 | return false; |
| 5305 | |
| 5306 | /* All other cases we need to wander into the node. */ |
| 5307 | return true; |
| 5308 | } |
| 5309 | |
| 5310 | static noinline void reada_walk_down(struct btrfs_trans_handle *trans, |
| 5311 | struct btrfs_root *root, |
| 5312 | struct walk_control *wc, |
| 5313 | struct btrfs_path *path) |
| 5314 | { |
| 5315 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 5316 | u64 bytenr; |
| 5317 | u64 generation; |
| 5318 | u64 refs; |
| 5319 | u64 flags; |
| 5320 | u32 nritems; |
| 5321 | struct extent_buffer *eb; |
| 5322 | int ret; |
| 5323 | int slot; |
| 5324 | int nread = 0; |
| 5325 | |
| 5326 | if (path->slots[wc->level] < wc->reada_slot) { |
| 5327 | wc->reada_count = wc->reada_count * 2 / 3; |
| 5328 | wc->reada_count = max(wc->reada_count, 2); |
| 5329 | } else { |
| 5330 | wc->reada_count = wc->reada_count * 3 / 2; |
| 5331 | wc->reada_count = min_t(int, wc->reada_count, |
| 5332 | BTRFS_NODEPTRS_PER_BLOCK(fs_info)); |
| 5333 | } |
| 5334 | |
| 5335 | eb = path->nodes[wc->level]; |
| 5336 | nritems = btrfs_header_nritems(eb); |
| 5337 | |
| 5338 | for (slot = path->slots[wc->level]; slot < nritems; slot++) { |
| 5339 | if (nread >= wc->reada_count) |
| 5340 | break; |
| 5341 | |
| 5342 | cond_resched(); |
| 5343 | bytenr = btrfs_node_blockptr(eb, slot); |
| 5344 | generation = btrfs_node_ptr_generation(eb, slot); |
| 5345 | |
| 5346 | if (slot == path->slots[wc->level]) |
| 5347 | goto reada; |
| 5348 | |
| 5349 | if (wc->stage == UPDATE_BACKREF && |
| 5350 | generation <= root->root_key.offset) |
| 5351 | continue; |
| 5352 | |
| 5353 | /* We don't lock the tree block, it's OK to be racy here */ |
| 5354 | ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, |
| 5355 | wc->level - 1, 1, &refs, |
| 5356 | &flags, NULL); |
| 5357 | /* We don't care about errors in readahead. */ |
| 5358 | if (ret < 0) |
| 5359 | continue; |
| 5360 | |
| 5361 | /* |
| 5362 | * This could be racey, it's conceivable that we raced and end |
| 5363 | * up with a bogus refs count, if that's the case just skip, if |
| 5364 | * we are actually corrupt we will notice when we look up |
| 5365 | * everything again with our locks. |
| 5366 | */ |
| 5367 | if (refs == 0) |
| 5368 | continue; |
| 5369 | |
| 5370 | /* If we don't need to visit this node don't reada. */ |
| 5371 | if (!visit_node_for_delete(root, wc, eb, refs, flags, slot)) |
| 5372 | continue; |
| 5373 | reada: |
| 5374 | btrfs_readahead_node_child(eb, slot); |
| 5375 | nread++; |
| 5376 | } |
| 5377 | wc->reada_slot = slot; |
| 5378 | } |
| 5379 | |
| 5380 | /* |
| 5381 | * helper to process tree block while walking down the tree. |
| 5382 | * |
| 5383 | * when wc->stage == UPDATE_BACKREF, this function updates |
| 5384 | * back refs for pointers in the block. |
| 5385 | * |
| 5386 | * NOTE: return value 1 means we should stop walking down. |
| 5387 | */ |
| 5388 | static noinline int walk_down_proc(struct btrfs_trans_handle *trans, |
| 5389 | struct btrfs_root *root, |
| 5390 | struct btrfs_path *path, |
| 5391 | struct walk_control *wc) |
| 5392 | { |
| 5393 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 5394 | int level = wc->level; |
| 5395 | struct extent_buffer *eb = path->nodes[level]; |
| 5396 | u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| 5397 | int ret; |
| 5398 | |
| 5399 | if (wc->stage == UPDATE_BACKREF && btrfs_header_owner(eb) != btrfs_root_id(root)) |
| 5400 | return 1; |
| 5401 | |
| 5402 | /* |
| 5403 | * when reference count of tree block is 1, it won't increase |
| 5404 | * again. once full backref flag is set, we never clear it. |
| 5405 | */ |
| 5406 | if (wc->lookup_info && |
| 5407 | ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) || |
| 5408 | (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) { |
| 5409 | ASSERT(path->locks[level]); |
| 5410 | ret = btrfs_lookup_extent_info(trans, fs_info, |
| 5411 | eb->start, level, 1, |
| 5412 | &wc->refs[level], |
| 5413 | &wc->flags[level], |
| 5414 | NULL); |
| 5415 | if (ret) |
| 5416 | return ret; |
| 5417 | if (unlikely(wc->refs[level] == 0)) { |
| 5418 | btrfs_err(fs_info, "bytenr %llu has 0 references, expect > 0", |
| 5419 | eb->start); |
| 5420 | return -EUCLEAN; |
| 5421 | } |
| 5422 | } |
| 5423 | |
| 5424 | if (wc->stage == DROP_REFERENCE) { |
| 5425 | if (wc->refs[level] > 1) |
| 5426 | return 1; |
| 5427 | |
| 5428 | if (path->locks[level] && !wc->keep_locks) { |
| 5429 | btrfs_tree_unlock_rw(eb, path->locks[level]); |
| 5430 | path->locks[level] = 0; |
| 5431 | } |
| 5432 | return 0; |
| 5433 | } |
| 5434 | |
| 5435 | /* wc->stage == UPDATE_BACKREF */ |
| 5436 | if (!(wc->flags[level] & flag)) { |
| 5437 | ASSERT(path->locks[level]); |
| 5438 | ret = btrfs_inc_ref(trans, root, eb, 1); |
| 5439 | if (ret) { |
| 5440 | btrfs_abort_transaction(trans, ret); |
| 5441 | return ret; |
| 5442 | } |
| 5443 | ret = btrfs_dec_ref(trans, root, eb, 0); |
| 5444 | if (ret) { |
| 5445 | btrfs_abort_transaction(trans, ret); |
| 5446 | return ret; |
| 5447 | } |
| 5448 | ret = btrfs_set_disk_extent_flags(trans, eb, flag); |
| 5449 | if (ret) { |
| 5450 | btrfs_abort_transaction(trans, ret); |
| 5451 | return ret; |
| 5452 | } |
| 5453 | wc->flags[level] |= flag; |
| 5454 | } |
| 5455 | |
| 5456 | /* |
| 5457 | * the block is shared by multiple trees, so it's not good to |
| 5458 | * keep the tree lock |
| 5459 | */ |
| 5460 | if (path->locks[level] && level > 0) { |
| 5461 | btrfs_tree_unlock_rw(eb, path->locks[level]); |
| 5462 | path->locks[level] = 0; |
| 5463 | } |
| 5464 | return 0; |
| 5465 | } |
| 5466 | |
| 5467 | /* |
| 5468 | * This is used to verify a ref exists for this root to deal with a bug where we |
| 5469 | * would have a drop_progress key that hadn't been updated properly. |
| 5470 | */ |
| 5471 | static int check_ref_exists(struct btrfs_trans_handle *trans, |
| 5472 | struct btrfs_root *root, u64 bytenr, u64 parent, |
| 5473 | int level) |
| 5474 | { |
| 5475 | struct btrfs_delayed_ref_root *delayed_refs; |
| 5476 | struct btrfs_delayed_ref_head *head; |
| 5477 | struct btrfs_path *path; |
| 5478 | struct btrfs_extent_inline_ref *iref; |
| 5479 | int ret; |
| 5480 | bool exists = false; |
| 5481 | |
| 5482 | path = btrfs_alloc_path(); |
| 5483 | if (!path) |
| 5484 | return -ENOMEM; |
| 5485 | again: |
| 5486 | ret = lookup_extent_backref(trans, path, &iref, bytenr, |
| 5487 | root->fs_info->nodesize, parent, |
| 5488 | btrfs_root_id(root), level, 0); |
| 5489 | if (ret != -ENOENT) { |
| 5490 | /* |
| 5491 | * If we get 0 then we found our reference, return 1, else |
| 5492 | * return the error if it's not -ENOENT; |
| 5493 | */ |
| 5494 | btrfs_free_path(path); |
| 5495 | return (ret < 0 ) ? ret : 1; |
| 5496 | } |
| 5497 | |
| 5498 | /* |
| 5499 | * We could have a delayed ref with this reference, so look it up while |
| 5500 | * we're holding the path open to make sure we don't race with the |
| 5501 | * delayed ref running. |
| 5502 | */ |
| 5503 | delayed_refs = &trans->transaction->delayed_refs; |
| 5504 | spin_lock(&delayed_refs->lock); |
| 5505 | head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); |
| 5506 | if (!head) |
| 5507 | goto out; |
| 5508 | if (!mutex_trylock(&head->mutex)) { |
| 5509 | /* |
| 5510 | * We're contended, means that the delayed ref is running, get a |
| 5511 | * reference and wait for the ref head to be complete and then |
| 5512 | * try again. |
| 5513 | */ |
| 5514 | refcount_inc(&head->refs); |
| 5515 | spin_unlock(&delayed_refs->lock); |
| 5516 | |
| 5517 | btrfs_release_path(path); |
| 5518 | |
| 5519 | mutex_lock(&head->mutex); |
| 5520 | mutex_unlock(&head->mutex); |
| 5521 | btrfs_put_delayed_ref_head(head); |
| 5522 | goto again; |
| 5523 | } |
| 5524 | |
| 5525 | exists = btrfs_find_delayed_tree_ref(head, root->root_key.objectid, parent); |
| 5526 | mutex_unlock(&head->mutex); |
| 5527 | out: |
| 5528 | spin_unlock(&delayed_refs->lock); |
| 5529 | btrfs_free_path(path); |
| 5530 | return exists ? 1 : 0; |
| 5531 | } |
| 5532 | |
| 5533 | /* |
| 5534 | * We may not have an uptodate block, so if we are going to walk down into this |
| 5535 | * block we need to drop the lock, read it off of the disk, re-lock it and |
| 5536 | * return to continue dropping the snapshot. |
| 5537 | */ |
| 5538 | static int check_next_block_uptodate(struct btrfs_trans_handle *trans, |
| 5539 | struct btrfs_root *root, |
| 5540 | struct btrfs_path *path, |
| 5541 | struct walk_control *wc, |
| 5542 | struct extent_buffer *next) |
| 5543 | { |
| 5544 | struct btrfs_tree_parent_check check = { 0 }; |
| 5545 | u64 generation; |
| 5546 | int level = wc->level; |
| 5547 | int ret; |
| 5548 | |
| 5549 | btrfs_assert_tree_write_locked(next); |
| 5550 | |
| 5551 | generation = btrfs_node_ptr_generation(path->nodes[level], path->slots[level]); |
| 5552 | |
| 5553 | if (btrfs_buffer_uptodate(next, generation, 0)) |
| 5554 | return 0; |
| 5555 | |
| 5556 | check.level = level - 1; |
| 5557 | check.transid = generation; |
| 5558 | check.owner_root = btrfs_root_id(root); |
| 5559 | check.has_first_key = true; |
| 5560 | btrfs_node_key_to_cpu(path->nodes[level], &check.first_key, path->slots[level]); |
| 5561 | |
| 5562 | btrfs_tree_unlock(next); |
| 5563 | if (level == 1) |
| 5564 | reada_walk_down(trans, root, wc, path); |
| 5565 | ret = btrfs_read_extent_buffer(next, &check); |
| 5566 | if (ret) { |
| 5567 | free_extent_buffer(next); |
| 5568 | return ret; |
| 5569 | } |
| 5570 | btrfs_tree_lock(next); |
| 5571 | wc->lookup_info = 1; |
| 5572 | return 0; |
| 5573 | } |
| 5574 | |
| 5575 | /* |
| 5576 | * If we determine that we don't have to visit wc->level - 1 then we need to |
| 5577 | * determine if we can drop our reference. |
| 5578 | * |
| 5579 | * If we are UPDATE_BACKREF then we will not, we need to update our backrefs. |
| 5580 | * |
| 5581 | * If we are DROP_REFERENCE this will figure out if we need to drop our current |
| 5582 | * reference, skipping it if we dropped it from a previous incompleted drop, or |
| 5583 | * dropping it if we still have a reference to it. |
| 5584 | */ |
| 5585 | static int maybe_drop_reference(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| 5586 | struct btrfs_path *path, struct walk_control *wc, |
| 5587 | struct extent_buffer *next, u64 owner_root) |
| 5588 | { |
| 5589 | struct btrfs_ref ref = { |
| 5590 | .action = BTRFS_DROP_DELAYED_REF, |
| 5591 | .bytenr = next->start, |
| 5592 | .num_bytes = root->fs_info->nodesize, |
| 5593 | .owning_root = owner_root, |
| 5594 | .ref_root = btrfs_root_id(root), |
| 5595 | }; |
| 5596 | int level = wc->level; |
| 5597 | int ret; |
| 5598 | |
| 5599 | /* We are UPDATE_BACKREF, we're not dropping anything. */ |
| 5600 | if (wc->stage == UPDATE_BACKREF) |
| 5601 | return 0; |
| 5602 | |
| 5603 | if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) { |
| 5604 | ref.parent = path->nodes[level]->start; |
| 5605 | } else { |
| 5606 | ASSERT(btrfs_root_id(root) == btrfs_header_owner(path->nodes[level])); |
| 5607 | if (btrfs_root_id(root) != btrfs_header_owner(path->nodes[level])) { |
| 5608 | btrfs_err(root->fs_info, "mismatched block owner"); |
| 5609 | return -EIO; |
| 5610 | } |
| 5611 | } |
| 5612 | |
| 5613 | /* |
| 5614 | * If we had a drop_progress we need to verify the refs are set as |
| 5615 | * expected. If we find our ref then we know that from here on out |
| 5616 | * everything should be correct, and we can clear the |
| 5617 | * ->restarted flag. |
| 5618 | */ |
| 5619 | if (wc->restarted) { |
| 5620 | ret = check_ref_exists(trans, root, next->start, ref.parent, |
| 5621 | level - 1); |
| 5622 | if (ret <= 0) |
| 5623 | return ret; |
| 5624 | ret = 0; |
| 5625 | wc->restarted = 0; |
| 5626 | } |
| 5627 | |
| 5628 | /* |
| 5629 | * Reloc tree doesn't contribute to qgroup numbers, and we have already |
| 5630 | * accounted them at merge time (replace_path), thus we could skip |
| 5631 | * expensive subtree trace here. |
| 5632 | */ |
| 5633 | if (btrfs_root_id(root) != BTRFS_TREE_RELOC_OBJECTID && |
| 5634 | wc->refs[level - 1] > 1) { |
| 5635 | u64 generation = btrfs_node_ptr_generation(path->nodes[level], |
| 5636 | path->slots[level]); |
| 5637 | |
| 5638 | ret = btrfs_qgroup_trace_subtree(trans, next, generation, level - 1); |
| 5639 | if (ret) { |
| 5640 | btrfs_err_rl(root->fs_info, |
| 5641 | "error %d accounting shared subtree, quota is out of sync, rescan required", |
| 5642 | ret); |
| 5643 | } |
| 5644 | } |
| 5645 | |
| 5646 | /* |
| 5647 | * We need to update the next key in our walk control so we can update |
| 5648 | * the drop_progress key accordingly. We don't care if find_next_key |
| 5649 | * doesn't find a key because that means we're at the end and are going |
| 5650 | * to clean up now. |
| 5651 | */ |
| 5652 | wc->drop_level = level; |
| 5653 | find_next_key(path, level, &wc->drop_progress); |
| 5654 | |
| 5655 | btrfs_init_tree_ref(&ref, level - 1, 0, false); |
| 5656 | return btrfs_free_extent(trans, &ref); |
| 5657 | } |
| 5658 | |
| 5659 | /* |
| 5660 | * helper to process tree block pointer. |
| 5661 | * |
| 5662 | * when wc->stage == DROP_REFERENCE, this function checks |
| 5663 | * reference count of the block pointed to. if the block |
| 5664 | * is shared and we need update back refs for the subtree |
| 5665 | * rooted at the block, this function changes wc->stage to |
| 5666 | * UPDATE_BACKREF. if the block is shared and there is no |
| 5667 | * need to update back, this function drops the reference |
| 5668 | * to the block. |
| 5669 | * |
| 5670 | * NOTE: return value 1 means we should stop walking down. |
| 5671 | */ |
| 5672 | static noinline int do_walk_down(struct btrfs_trans_handle *trans, |
| 5673 | struct btrfs_root *root, |
| 5674 | struct btrfs_path *path, |
| 5675 | struct walk_control *wc) |
| 5676 | { |
| 5677 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 5678 | u64 bytenr; |
| 5679 | u64 generation; |
| 5680 | u64 owner_root = 0; |
| 5681 | struct extent_buffer *next; |
| 5682 | int level = wc->level; |
| 5683 | int ret = 0; |
| 5684 | |
| 5685 | generation = btrfs_node_ptr_generation(path->nodes[level], |
| 5686 | path->slots[level]); |
| 5687 | /* |
| 5688 | * if the lower level block was created before the snapshot |
| 5689 | * was created, we know there is no need to update back refs |
| 5690 | * for the subtree |
| 5691 | */ |
| 5692 | if (wc->stage == UPDATE_BACKREF && |
| 5693 | generation <= root->root_key.offset) { |
| 5694 | wc->lookup_info = 1; |
| 5695 | return 1; |
| 5696 | } |
| 5697 | |
| 5698 | bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]); |
| 5699 | |
| 5700 | next = btrfs_find_create_tree_block(fs_info, bytenr, btrfs_root_id(root), |
| 5701 | level - 1); |
| 5702 | if (IS_ERR(next)) |
| 5703 | return PTR_ERR(next); |
| 5704 | |
| 5705 | btrfs_tree_lock(next); |
| 5706 | |
| 5707 | ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1, |
| 5708 | &wc->refs[level - 1], |
| 5709 | &wc->flags[level - 1], |
| 5710 | &owner_root); |
| 5711 | if (ret < 0) |
| 5712 | goto out_unlock; |
| 5713 | |
| 5714 | if (unlikely(wc->refs[level - 1] == 0)) { |
| 5715 | btrfs_err(fs_info, "bytenr %llu has 0 references, expect > 0", |
| 5716 | bytenr); |
| 5717 | ret = -EUCLEAN; |
| 5718 | goto out_unlock; |
| 5719 | } |
| 5720 | wc->lookup_info = 0; |
| 5721 | |
| 5722 | /* If we don't have to walk into this node skip it. */ |
| 5723 | if (!visit_node_for_delete(root, wc, path->nodes[level], |
| 5724 | wc->refs[level - 1], wc->flags[level - 1], |
| 5725 | path->slots[level])) |
| 5726 | goto skip; |
| 5727 | |
| 5728 | /* |
| 5729 | * We have to walk down into this node, and if we're currently at the |
| 5730 | * DROP_REFERNCE stage and this block is shared then we need to switch |
| 5731 | * to the UPDATE_BACKREF stage in order to convert to FULL_BACKREF. |
| 5732 | */ |
| 5733 | if (wc->stage == DROP_REFERENCE && wc->refs[level - 1] > 1) { |
| 5734 | wc->stage = UPDATE_BACKREF; |
| 5735 | wc->shared_level = level - 1; |
| 5736 | } |
| 5737 | |
| 5738 | ret = check_next_block_uptodate(trans, root, path, wc, next); |
| 5739 | if (ret) |
| 5740 | return ret; |
| 5741 | |
| 5742 | level--; |
| 5743 | ASSERT(level == btrfs_header_level(next)); |
| 5744 | if (level != btrfs_header_level(next)) { |
| 5745 | btrfs_err(root->fs_info, "mismatched level"); |
| 5746 | ret = -EIO; |
| 5747 | goto out_unlock; |
| 5748 | } |
| 5749 | path->nodes[level] = next; |
| 5750 | path->slots[level] = 0; |
| 5751 | path->locks[level] = BTRFS_WRITE_LOCK; |
| 5752 | wc->level = level; |
| 5753 | if (wc->level == 1) |
| 5754 | wc->reada_slot = 0; |
| 5755 | return 0; |
| 5756 | skip: |
| 5757 | ret = maybe_drop_reference(trans, root, path, wc, next, owner_root); |
| 5758 | if (ret) |
| 5759 | goto out_unlock; |
| 5760 | wc->refs[level - 1] = 0; |
| 5761 | wc->flags[level - 1] = 0; |
| 5762 | wc->lookup_info = 1; |
| 5763 | ret = 1; |
| 5764 | |
| 5765 | out_unlock: |
| 5766 | btrfs_tree_unlock(next); |
| 5767 | free_extent_buffer(next); |
| 5768 | |
| 5769 | return ret; |
| 5770 | } |
| 5771 | |
| 5772 | /* |
| 5773 | * helper to process tree block while walking up the tree. |
| 5774 | * |
| 5775 | * when wc->stage == DROP_REFERENCE, this function drops |
| 5776 | * reference count on the block. |
| 5777 | * |
| 5778 | * when wc->stage == UPDATE_BACKREF, this function changes |
| 5779 | * wc->stage back to DROP_REFERENCE if we changed wc->stage |
| 5780 | * to UPDATE_BACKREF previously while processing the block. |
| 5781 | * |
| 5782 | * NOTE: return value 1 means we should stop walking up. |
| 5783 | */ |
| 5784 | static noinline int walk_up_proc(struct btrfs_trans_handle *trans, |
| 5785 | struct btrfs_root *root, |
| 5786 | struct btrfs_path *path, |
| 5787 | struct walk_control *wc) |
| 5788 | { |
| 5789 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 5790 | int ret = 0; |
| 5791 | int level = wc->level; |
| 5792 | struct extent_buffer *eb = path->nodes[level]; |
| 5793 | u64 parent = 0; |
| 5794 | |
| 5795 | if (wc->stage == UPDATE_BACKREF) { |
| 5796 | ASSERT(wc->shared_level >= level); |
| 5797 | if (level < wc->shared_level) |
| 5798 | goto out; |
| 5799 | |
| 5800 | ret = find_next_key(path, level + 1, &wc->update_progress); |
| 5801 | if (ret > 0) |
| 5802 | wc->update_ref = 0; |
| 5803 | |
| 5804 | wc->stage = DROP_REFERENCE; |
| 5805 | wc->shared_level = -1; |
| 5806 | path->slots[level] = 0; |
| 5807 | |
| 5808 | /* |
| 5809 | * check reference count again if the block isn't locked. |
| 5810 | * we should start walking down the tree again if reference |
| 5811 | * count is one. |
| 5812 | */ |
| 5813 | if (!path->locks[level]) { |
| 5814 | ASSERT(level > 0); |
| 5815 | btrfs_tree_lock(eb); |
| 5816 | path->locks[level] = BTRFS_WRITE_LOCK; |
| 5817 | |
| 5818 | ret = btrfs_lookup_extent_info(trans, fs_info, |
| 5819 | eb->start, level, 1, |
| 5820 | &wc->refs[level], |
| 5821 | &wc->flags[level], |
| 5822 | NULL); |
| 5823 | if (ret < 0) { |
| 5824 | btrfs_tree_unlock_rw(eb, path->locks[level]); |
| 5825 | path->locks[level] = 0; |
| 5826 | return ret; |
| 5827 | } |
| 5828 | if (unlikely(wc->refs[level] == 0)) { |
| 5829 | btrfs_tree_unlock_rw(eb, path->locks[level]); |
| 5830 | btrfs_err(fs_info, "bytenr %llu has 0 references, expect > 0", |
| 5831 | eb->start); |
| 5832 | return -EUCLEAN; |
| 5833 | } |
| 5834 | if (wc->refs[level] == 1) { |
| 5835 | btrfs_tree_unlock_rw(eb, path->locks[level]); |
| 5836 | path->locks[level] = 0; |
| 5837 | return 1; |
| 5838 | } |
| 5839 | } |
| 5840 | } |
| 5841 | |
| 5842 | /* wc->stage == DROP_REFERENCE */ |
| 5843 | ASSERT(path->locks[level] || wc->refs[level] == 1); |
| 5844 | |
| 5845 | if (wc->refs[level] == 1) { |
| 5846 | if (level == 0) { |
| 5847 | if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| 5848 | ret = btrfs_dec_ref(trans, root, eb, 1); |
| 5849 | else |
| 5850 | ret = btrfs_dec_ref(trans, root, eb, 0); |
| 5851 | if (ret) { |
| 5852 | btrfs_abort_transaction(trans, ret); |
| 5853 | return ret; |
| 5854 | } |
| 5855 | if (is_fstree(btrfs_root_id(root))) { |
| 5856 | ret = btrfs_qgroup_trace_leaf_items(trans, eb); |
| 5857 | if (ret) { |
| 5858 | btrfs_err_rl(fs_info, |
| 5859 | "error %d accounting leaf items, quota is out of sync, rescan required", |
| 5860 | ret); |
| 5861 | } |
| 5862 | } |
| 5863 | } |
| 5864 | /* Make block locked assertion in btrfs_clear_buffer_dirty happy. */ |
| 5865 | if (!path->locks[level]) { |
| 5866 | btrfs_tree_lock(eb); |
| 5867 | path->locks[level] = BTRFS_WRITE_LOCK; |
| 5868 | } |
| 5869 | btrfs_clear_buffer_dirty(trans, eb); |
| 5870 | } |
| 5871 | |
| 5872 | if (eb == root->node) { |
| 5873 | if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| 5874 | parent = eb->start; |
| 5875 | else if (btrfs_root_id(root) != btrfs_header_owner(eb)) |
| 5876 | goto owner_mismatch; |
| 5877 | } else { |
| 5878 | if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| 5879 | parent = path->nodes[level + 1]->start; |
| 5880 | else if (btrfs_root_id(root) != |
| 5881 | btrfs_header_owner(path->nodes[level + 1])) |
| 5882 | goto owner_mismatch; |
| 5883 | } |
| 5884 | |
| 5885 | ret = btrfs_free_tree_block(trans, btrfs_root_id(root), eb, parent, |
| 5886 | wc->refs[level] == 1); |
| 5887 | if (ret < 0) |
| 5888 | btrfs_abort_transaction(trans, ret); |
| 5889 | out: |
| 5890 | wc->refs[level] = 0; |
| 5891 | wc->flags[level] = 0; |
| 5892 | return ret; |
| 5893 | |
| 5894 | owner_mismatch: |
| 5895 | btrfs_err_rl(fs_info, "unexpected tree owner, have %llu expect %llu", |
| 5896 | btrfs_header_owner(eb), btrfs_root_id(root)); |
| 5897 | return -EUCLEAN; |
| 5898 | } |
| 5899 | |
| 5900 | /* |
| 5901 | * walk_down_tree consists of two steps. |
| 5902 | * |
| 5903 | * walk_down_proc(). Look up the reference count and reference of our current |
| 5904 | * wc->level. At this point path->nodes[wc->level] should be populated and |
| 5905 | * uptodate, and in most cases should already be locked. If we are in |
| 5906 | * DROP_REFERENCE and our refcount is > 1 then we've entered a shared node and |
| 5907 | * we can walk back up the tree. If we are UPDATE_BACKREF we have to set |
| 5908 | * FULL_BACKREF on this node if it's not already set, and then do the |
| 5909 | * FULL_BACKREF conversion dance, which is to drop the root reference and add |
| 5910 | * the shared reference to all of this nodes children. |
| 5911 | * |
| 5912 | * do_walk_down(). This is where we actually start iterating on the children of |
| 5913 | * our current path->nodes[wc->level]. For DROP_REFERENCE that means dropping |
| 5914 | * our reference to the children that return false from visit_node_for_delete(), |
| 5915 | * which has various conditions where we know we can just drop our reference |
| 5916 | * without visiting the node. For UPDATE_BACKREF we will skip any children that |
| 5917 | * visit_node_for_delete() returns false for, only walking down when necessary. |
| 5918 | * The bulk of the work for UPDATE_BACKREF occurs in the walk_up_tree() part of |
| 5919 | * snapshot deletion. |
| 5920 | */ |
| 5921 | static noinline int walk_down_tree(struct btrfs_trans_handle *trans, |
| 5922 | struct btrfs_root *root, |
| 5923 | struct btrfs_path *path, |
| 5924 | struct walk_control *wc) |
| 5925 | { |
| 5926 | int level = wc->level; |
| 5927 | int ret = 0; |
| 5928 | |
| 5929 | wc->lookup_info = 1; |
| 5930 | while (level >= 0) { |
| 5931 | ret = walk_down_proc(trans, root, path, wc); |
| 5932 | if (ret) |
| 5933 | break; |
| 5934 | |
| 5935 | if (level == 0) |
| 5936 | break; |
| 5937 | |
| 5938 | if (path->slots[level] >= |
| 5939 | btrfs_header_nritems(path->nodes[level])) |
| 5940 | break; |
| 5941 | |
| 5942 | ret = do_walk_down(trans, root, path, wc); |
| 5943 | if (ret > 0) { |
| 5944 | path->slots[level]++; |
| 5945 | continue; |
| 5946 | } else if (ret < 0) |
| 5947 | break; |
| 5948 | level = wc->level; |
| 5949 | } |
| 5950 | return (ret == 1) ? 0 : ret; |
| 5951 | } |
| 5952 | |
| 5953 | /* |
| 5954 | * walk_up_tree() is responsible for making sure we visit every slot on our |
| 5955 | * current node, and if we're at the end of that node then we call |
| 5956 | * walk_up_proc() on our current node which will do one of a few things based on |
| 5957 | * our stage. |
| 5958 | * |
| 5959 | * UPDATE_BACKREF. If we wc->level is currently less than our wc->shared_level |
| 5960 | * then we need to walk back up the tree, and then going back down into the |
| 5961 | * other slots via walk_down_tree to update any other children from our original |
| 5962 | * wc->shared_level. Once we're at or above our wc->shared_level we can switch |
| 5963 | * back to DROP_REFERENCE, lookup the current nodes refs and flags, and carry on. |
| 5964 | * |
| 5965 | * DROP_REFERENCE. If our refs == 1 then we're going to free this tree block. |
| 5966 | * If we're level 0 then we need to btrfs_dec_ref() on all of the data extents |
| 5967 | * in our current leaf. After that we call btrfs_free_tree_block() on the |
| 5968 | * current node and walk up to the next node to walk down the next slot. |
| 5969 | */ |
| 5970 | static noinline int walk_up_tree(struct btrfs_trans_handle *trans, |
| 5971 | struct btrfs_root *root, |
| 5972 | struct btrfs_path *path, |
| 5973 | struct walk_control *wc, int max_level) |
| 5974 | { |
| 5975 | int level = wc->level; |
| 5976 | int ret; |
| 5977 | |
| 5978 | path->slots[level] = btrfs_header_nritems(path->nodes[level]); |
| 5979 | while (level < max_level && path->nodes[level]) { |
| 5980 | wc->level = level; |
| 5981 | if (path->slots[level] + 1 < |
| 5982 | btrfs_header_nritems(path->nodes[level])) { |
| 5983 | path->slots[level]++; |
| 5984 | return 0; |
| 5985 | } else { |
| 5986 | ret = walk_up_proc(trans, root, path, wc); |
| 5987 | if (ret > 0) |
| 5988 | return 0; |
| 5989 | if (ret < 0) |
| 5990 | return ret; |
| 5991 | |
| 5992 | if (path->locks[level]) { |
| 5993 | btrfs_tree_unlock_rw(path->nodes[level], |
| 5994 | path->locks[level]); |
| 5995 | path->locks[level] = 0; |
| 5996 | } |
| 5997 | free_extent_buffer(path->nodes[level]); |
| 5998 | path->nodes[level] = NULL; |
| 5999 | level++; |
| 6000 | } |
| 6001 | } |
| 6002 | return 1; |
| 6003 | } |
| 6004 | |
| 6005 | /* |
| 6006 | * drop a subvolume tree. |
| 6007 | * |
| 6008 | * this function traverses the tree freeing any blocks that only |
| 6009 | * referenced by the tree. |
| 6010 | * |
| 6011 | * when a shared tree block is found. this function decreases its |
| 6012 | * reference count by one. if update_ref is true, this function |
| 6013 | * also make sure backrefs for the shared block and all lower level |
| 6014 | * blocks are properly updated. |
| 6015 | * |
| 6016 | * If called with for_reloc == 0, may exit early with -EAGAIN |
| 6017 | */ |
| 6018 | int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) |
| 6019 | { |
| 6020 | const bool is_reloc_root = (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID); |
| 6021 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 6022 | struct btrfs_path *path; |
| 6023 | struct btrfs_trans_handle *trans; |
| 6024 | struct btrfs_root *tree_root = fs_info->tree_root; |
| 6025 | struct btrfs_root_item *root_item = &root->root_item; |
| 6026 | struct walk_control *wc; |
| 6027 | struct btrfs_key key; |
| 6028 | const u64 rootid = btrfs_root_id(root); |
| 6029 | int ret = 0; |
| 6030 | int level; |
| 6031 | bool root_dropped = false; |
| 6032 | bool unfinished_drop = false; |
| 6033 | |
| 6034 | btrfs_debug(fs_info, "Drop subvolume %llu", btrfs_root_id(root)); |
| 6035 | |
| 6036 | path = btrfs_alloc_path(); |
| 6037 | if (!path) { |
| 6038 | ret = -ENOMEM; |
| 6039 | goto out; |
| 6040 | } |
| 6041 | |
| 6042 | wc = kzalloc(sizeof(*wc), GFP_NOFS); |
| 6043 | if (!wc) { |
| 6044 | btrfs_free_path(path); |
| 6045 | ret = -ENOMEM; |
| 6046 | goto out; |
| 6047 | } |
| 6048 | |
| 6049 | /* |
| 6050 | * Use join to avoid potential EINTR from transaction start. See |
| 6051 | * wait_reserve_ticket and the whole reservation callchain. |
| 6052 | */ |
| 6053 | if (for_reloc) |
| 6054 | trans = btrfs_join_transaction(tree_root); |
| 6055 | else |
| 6056 | trans = btrfs_start_transaction(tree_root, 0); |
| 6057 | if (IS_ERR(trans)) { |
| 6058 | ret = PTR_ERR(trans); |
| 6059 | goto out_free; |
| 6060 | } |
| 6061 | |
| 6062 | ret = btrfs_run_delayed_items(trans); |
| 6063 | if (ret) |
| 6064 | goto out_end_trans; |
| 6065 | |
| 6066 | /* |
| 6067 | * This will help us catch people modifying the fs tree while we're |
| 6068 | * dropping it. It is unsafe to mess with the fs tree while it's being |
| 6069 | * dropped as we unlock the root node and parent nodes as we walk down |
| 6070 | * the tree, assuming nothing will change. If something does change |
| 6071 | * then we'll have stale information and drop references to blocks we've |
| 6072 | * already dropped. |
| 6073 | */ |
| 6074 | set_bit(BTRFS_ROOT_DELETING, &root->state); |
| 6075 | unfinished_drop = test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state); |
| 6076 | |
| 6077 | if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { |
| 6078 | level = btrfs_header_level(root->node); |
| 6079 | path->nodes[level] = btrfs_lock_root_node(root); |
| 6080 | path->slots[level] = 0; |
| 6081 | path->locks[level] = BTRFS_WRITE_LOCK; |
| 6082 | memset(&wc->update_progress, 0, |
| 6083 | sizeof(wc->update_progress)); |
| 6084 | } else { |
| 6085 | btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); |
| 6086 | memcpy(&wc->update_progress, &key, |
| 6087 | sizeof(wc->update_progress)); |
| 6088 | |
| 6089 | level = btrfs_root_drop_level(root_item); |
| 6090 | BUG_ON(level == 0); |
| 6091 | path->lowest_level = level; |
| 6092 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 6093 | path->lowest_level = 0; |
| 6094 | if (ret < 0) |
| 6095 | goto out_end_trans; |
| 6096 | |
| 6097 | WARN_ON(ret > 0); |
| 6098 | ret = 0; |
| 6099 | |
| 6100 | /* |
| 6101 | * unlock our path, this is safe because only this |
| 6102 | * function is allowed to delete this snapshot |
| 6103 | */ |
| 6104 | btrfs_unlock_up_safe(path, 0); |
| 6105 | |
| 6106 | level = btrfs_header_level(root->node); |
| 6107 | while (1) { |
| 6108 | btrfs_tree_lock(path->nodes[level]); |
| 6109 | path->locks[level] = BTRFS_WRITE_LOCK; |
| 6110 | |
| 6111 | /* |
| 6112 | * btrfs_lookup_extent_info() returns 0 for success, |
| 6113 | * or < 0 for error. |
| 6114 | */ |
| 6115 | ret = btrfs_lookup_extent_info(trans, fs_info, |
| 6116 | path->nodes[level]->start, |
| 6117 | level, 1, &wc->refs[level], |
| 6118 | &wc->flags[level], NULL); |
| 6119 | if (ret < 0) |
| 6120 | goto out_end_trans; |
| 6121 | |
| 6122 | BUG_ON(wc->refs[level] == 0); |
| 6123 | |
| 6124 | if (level == btrfs_root_drop_level(root_item)) |
| 6125 | break; |
| 6126 | |
| 6127 | btrfs_tree_unlock(path->nodes[level]); |
| 6128 | path->locks[level] = 0; |
| 6129 | WARN_ON(wc->refs[level] != 1); |
| 6130 | level--; |
| 6131 | } |
| 6132 | } |
| 6133 | |
| 6134 | wc->restarted = test_bit(BTRFS_ROOT_DEAD_TREE, &root->state); |
| 6135 | wc->level = level; |
| 6136 | wc->shared_level = -1; |
| 6137 | wc->stage = DROP_REFERENCE; |
| 6138 | wc->update_ref = update_ref; |
| 6139 | wc->keep_locks = 0; |
| 6140 | wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info); |
| 6141 | |
| 6142 | while (1) { |
| 6143 | |
| 6144 | ret = walk_down_tree(trans, root, path, wc); |
| 6145 | if (ret < 0) { |
| 6146 | btrfs_abort_transaction(trans, ret); |
| 6147 | break; |
| 6148 | } |
| 6149 | |
| 6150 | ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL); |
| 6151 | if (ret < 0) { |
| 6152 | btrfs_abort_transaction(trans, ret); |
| 6153 | break; |
| 6154 | } |
| 6155 | |
| 6156 | if (ret > 0) { |
| 6157 | BUG_ON(wc->stage != DROP_REFERENCE); |
| 6158 | ret = 0; |
| 6159 | break; |
| 6160 | } |
| 6161 | |
| 6162 | if (wc->stage == DROP_REFERENCE) { |
| 6163 | wc->drop_level = wc->level; |
| 6164 | btrfs_node_key_to_cpu(path->nodes[wc->drop_level], |
| 6165 | &wc->drop_progress, |
| 6166 | path->slots[wc->drop_level]); |
| 6167 | } |
| 6168 | btrfs_cpu_key_to_disk(&root_item->drop_progress, |
| 6169 | &wc->drop_progress); |
| 6170 | btrfs_set_root_drop_level(root_item, wc->drop_level); |
| 6171 | |
| 6172 | BUG_ON(wc->level == 0); |
| 6173 | if (btrfs_should_end_transaction(trans) || |
| 6174 | (!for_reloc && btrfs_need_cleaner_sleep(fs_info))) { |
| 6175 | ret = btrfs_update_root(trans, tree_root, |
| 6176 | &root->root_key, |
| 6177 | root_item); |
| 6178 | if (ret) { |
| 6179 | btrfs_abort_transaction(trans, ret); |
| 6180 | goto out_end_trans; |
| 6181 | } |
| 6182 | |
| 6183 | if (!is_reloc_root) |
| 6184 | btrfs_set_last_root_drop_gen(fs_info, trans->transid); |
| 6185 | |
| 6186 | btrfs_end_transaction_throttle(trans); |
| 6187 | if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) { |
| 6188 | btrfs_debug(fs_info, |
| 6189 | "drop snapshot early exit"); |
| 6190 | ret = -EAGAIN; |
| 6191 | goto out_free; |
| 6192 | } |
| 6193 | |
| 6194 | /* |
| 6195 | * Use join to avoid potential EINTR from transaction |
| 6196 | * start. See wait_reserve_ticket and the whole |
| 6197 | * reservation callchain. |
| 6198 | */ |
| 6199 | if (for_reloc) |
| 6200 | trans = btrfs_join_transaction(tree_root); |
| 6201 | else |
| 6202 | trans = btrfs_start_transaction(tree_root, 0); |
| 6203 | if (IS_ERR(trans)) { |
| 6204 | ret = PTR_ERR(trans); |
| 6205 | goto out_free; |
| 6206 | } |
| 6207 | } |
| 6208 | } |
| 6209 | btrfs_release_path(path); |
| 6210 | if (ret) |
| 6211 | goto out_end_trans; |
| 6212 | |
| 6213 | ret = btrfs_del_root(trans, &root->root_key); |
| 6214 | if (ret) { |
| 6215 | btrfs_abort_transaction(trans, ret); |
| 6216 | goto out_end_trans; |
| 6217 | } |
| 6218 | |
| 6219 | if (!is_reloc_root) { |
| 6220 | ret = btrfs_find_root(tree_root, &root->root_key, path, |
| 6221 | NULL, NULL); |
| 6222 | if (ret < 0) { |
| 6223 | btrfs_abort_transaction(trans, ret); |
| 6224 | goto out_end_trans; |
| 6225 | } else if (ret > 0) { |
| 6226 | ret = 0; |
| 6227 | /* |
| 6228 | * If we fail to delete the orphan item this time |
| 6229 | * around, it'll get picked up the next time. |
| 6230 | * |
| 6231 | * The most common failure here is just -ENOENT. |
| 6232 | */ |
| 6233 | btrfs_del_orphan_item(trans, tree_root, btrfs_root_id(root)); |
| 6234 | } |
| 6235 | } |
| 6236 | |
| 6237 | /* |
| 6238 | * This subvolume is going to be completely dropped, and won't be |
| 6239 | * recorded as dirty roots, thus pertrans meta rsv will not be freed at |
| 6240 | * commit transaction time. So free it here manually. |
| 6241 | */ |
| 6242 | btrfs_qgroup_convert_reserved_meta(root, INT_MAX); |
| 6243 | btrfs_qgroup_free_meta_all_pertrans(root); |
| 6244 | |
| 6245 | if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) |
| 6246 | btrfs_add_dropped_root(trans, root); |
| 6247 | else |
| 6248 | btrfs_put_root(root); |
| 6249 | root_dropped = true; |
| 6250 | out_end_trans: |
| 6251 | if (!is_reloc_root) |
| 6252 | btrfs_set_last_root_drop_gen(fs_info, trans->transid); |
| 6253 | |
| 6254 | btrfs_end_transaction_throttle(trans); |
| 6255 | out_free: |
| 6256 | kfree(wc); |
| 6257 | btrfs_free_path(path); |
| 6258 | out: |
| 6259 | if (!ret && root_dropped) { |
| 6260 | ret = btrfs_qgroup_cleanup_dropped_subvolume(fs_info, rootid); |
| 6261 | if (ret < 0) |
| 6262 | btrfs_warn_rl(fs_info, |
| 6263 | "failed to cleanup qgroup 0/%llu: %d", |
| 6264 | rootid, ret); |
| 6265 | ret = 0; |
| 6266 | } |
| 6267 | /* |
| 6268 | * We were an unfinished drop root, check to see if there are any |
| 6269 | * pending, and if not clear and wake up any waiters. |
| 6270 | */ |
| 6271 | if (!ret && unfinished_drop) |
| 6272 | btrfs_maybe_wake_unfinished_drop(fs_info); |
| 6273 | |
| 6274 | /* |
| 6275 | * So if we need to stop dropping the snapshot for whatever reason we |
| 6276 | * need to make sure to add it back to the dead root list so that we |
| 6277 | * keep trying to do the work later. This also cleans up roots if we |
| 6278 | * don't have it in the radix (like when we recover after a power fail |
| 6279 | * or unmount) so we don't leak memory. |
| 6280 | */ |
| 6281 | if (!for_reloc && !root_dropped) |
| 6282 | btrfs_add_dead_root(root); |
| 6283 | return ret; |
| 6284 | } |
| 6285 | |
| 6286 | /* |
| 6287 | * drop subtree rooted at tree block 'node'. |
| 6288 | * |
| 6289 | * NOTE: this function will unlock and release tree block 'node' |
| 6290 | * only used by relocation code |
| 6291 | */ |
| 6292 | int btrfs_drop_subtree(struct btrfs_trans_handle *trans, |
| 6293 | struct btrfs_root *root, |
| 6294 | struct extent_buffer *node, |
| 6295 | struct extent_buffer *parent) |
| 6296 | { |
| 6297 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 6298 | struct btrfs_path *path; |
| 6299 | struct walk_control *wc; |
| 6300 | int level; |
| 6301 | int parent_level; |
| 6302 | int ret = 0; |
| 6303 | |
| 6304 | BUG_ON(btrfs_root_id(root) != BTRFS_TREE_RELOC_OBJECTID); |
| 6305 | |
| 6306 | path = btrfs_alloc_path(); |
| 6307 | if (!path) |
| 6308 | return -ENOMEM; |
| 6309 | |
| 6310 | wc = kzalloc(sizeof(*wc), GFP_NOFS); |
| 6311 | if (!wc) { |
| 6312 | btrfs_free_path(path); |
| 6313 | return -ENOMEM; |
| 6314 | } |
| 6315 | |
| 6316 | btrfs_assert_tree_write_locked(parent); |
| 6317 | parent_level = btrfs_header_level(parent); |
| 6318 | atomic_inc(&parent->refs); |
| 6319 | path->nodes[parent_level] = parent; |
| 6320 | path->slots[parent_level] = btrfs_header_nritems(parent); |
| 6321 | |
| 6322 | btrfs_assert_tree_write_locked(node); |
| 6323 | level = btrfs_header_level(node); |
| 6324 | path->nodes[level] = node; |
| 6325 | path->slots[level] = 0; |
| 6326 | path->locks[level] = BTRFS_WRITE_LOCK; |
| 6327 | |
| 6328 | wc->refs[parent_level] = 1; |
| 6329 | wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| 6330 | wc->level = level; |
| 6331 | wc->shared_level = -1; |
| 6332 | wc->stage = DROP_REFERENCE; |
| 6333 | wc->update_ref = 0; |
| 6334 | wc->keep_locks = 1; |
| 6335 | wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info); |
| 6336 | |
| 6337 | while (1) { |
| 6338 | ret = walk_down_tree(trans, root, path, wc); |
| 6339 | if (ret < 0) |
| 6340 | break; |
| 6341 | |
| 6342 | ret = walk_up_tree(trans, root, path, wc, parent_level); |
| 6343 | if (ret) { |
| 6344 | if (ret > 0) |
| 6345 | ret = 0; |
| 6346 | break; |
| 6347 | } |
| 6348 | } |
| 6349 | |
| 6350 | kfree(wc); |
| 6351 | btrfs_free_path(path); |
| 6352 | return ret; |
| 6353 | } |
| 6354 | |
| 6355 | /* |
| 6356 | * Unpin the extent range in an error context and don't add the space back. |
| 6357 | * Errors are not propagated further. |
| 6358 | */ |
| 6359 | void btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, u64 start, u64 end) |
| 6360 | { |
| 6361 | unpin_extent_range(fs_info, start, end, false); |
| 6362 | } |
| 6363 | |
| 6364 | /* |
| 6365 | * It used to be that old block groups would be left around forever. |
| 6366 | * Iterating over them would be enough to trim unused space. Since we |
| 6367 | * now automatically remove them, we also need to iterate over unallocated |
| 6368 | * space. |
| 6369 | * |
| 6370 | * We don't want a transaction for this since the discard may take a |
| 6371 | * substantial amount of time. We don't require that a transaction be |
| 6372 | * running, but we do need to take a running transaction into account |
| 6373 | * to ensure that we're not discarding chunks that were released or |
| 6374 | * allocated in the current transaction. |
| 6375 | * |
| 6376 | * Holding the chunks lock will prevent other threads from allocating |
| 6377 | * or releasing chunks, but it won't prevent a running transaction |
| 6378 | * from committing and releasing the memory that the pending chunks |
| 6379 | * list head uses. For that, we need to take a reference to the |
| 6380 | * transaction and hold the commit root sem. We only need to hold |
| 6381 | * it while performing the free space search since we have already |
| 6382 | * held back allocations. |
| 6383 | */ |
| 6384 | static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed) |
| 6385 | { |
| 6386 | u64 start = BTRFS_DEVICE_RANGE_RESERVED, len = 0, end = 0; |
| 6387 | int ret; |
| 6388 | |
| 6389 | *trimmed = 0; |
| 6390 | |
| 6391 | /* Discard not supported = nothing to do. */ |
| 6392 | if (!bdev_max_discard_sectors(device->bdev)) |
| 6393 | return 0; |
| 6394 | |
| 6395 | /* Not writable = nothing to do. */ |
| 6396 | if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) |
| 6397 | return 0; |
| 6398 | |
| 6399 | /* No free space = nothing to do. */ |
| 6400 | if (device->total_bytes <= device->bytes_used) |
| 6401 | return 0; |
| 6402 | |
| 6403 | ret = 0; |
| 6404 | |
| 6405 | while (1) { |
| 6406 | struct btrfs_fs_info *fs_info = device->fs_info; |
| 6407 | u64 bytes; |
| 6408 | |
| 6409 | ret = mutex_lock_interruptible(&fs_info->chunk_mutex); |
| 6410 | if (ret) |
| 6411 | break; |
| 6412 | |
| 6413 | find_first_clear_extent_bit(&device->alloc_state, start, |
| 6414 | &start, &end, |
| 6415 | CHUNK_TRIMMED | CHUNK_ALLOCATED); |
| 6416 | |
| 6417 | /* Check if there are any CHUNK_* bits left */ |
| 6418 | if (start > device->total_bytes) { |
| 6419 | WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); |
| 6420 | btrfs_warn_in_rcu(fs_info, |
| 6421 | "ignoring attempt to trim beyond device size: offset %llu length %llu device %s device size %llu", |
| 6422 | start, end - start + 1, |
| 6423 | btrfs_dev_name(device), |
| 6424 | device->total_bytes); |
| 6425 | mutex_unlock(&fs_info->chunk_mutex); |
| 6426 | ret = 0; |
| 6427 | break; |
| 6428 | } |
| 6429 | |
| 6430 | /* Ensure we skip the reserved space on each device. */ |
| 6431 | start = max_t(u64, start, BTRFS_DEVICE_RANGE_RESERVED); |
| 6432 | |
| 6433 | /* |
| 6434 | * If find_first_clear_extent_bit find a range that spans the |
| 6435 | * end of the device it will set end to -1, in this case it's up |
| 6436 | * to the caller to trim the value to the size of the device. |
| 6437 | */ |
| 6438 | end = min(end, device->total_bytes - 1); |
| 6439 | |
| 6440 | len = end - start + 1; |
| 6441 | |
| 6442 | /* We didn't find any extents */ |
| 6443 | if (!len) { |
| 6444 | mutex_unlock(&fs_info->chunk_mutex); |
| 6445 | ret = 0; |
| 6446 | break; |
| 6447 | } |
| 6448 | |
| 6449 | ret = btrfs_issue_discard(device->bdev, start, len, |
| 6450 | &bytes); |
| 6451 | if (!ret) |
| 6452 | set_extent_bit(&device->alloc_state, start, |
| 6453 | start + bytes - 1, CHUNK_TRIMMED, NULL); |
| 6454 | mutex_unlock(&fs_info->chunk_mutex); |
| 6455 | |
| 6456 | if (ret) |
| 6457 | break; |
| 6458 | |
| 6459 | start += len; |
| 6460 | *trimmed += bytes; |
| 6461 | |
| 6462 | if (fatal_signal_pending(current)) { |
| 6463 | ret = -ERESTARTSYS; |
| 6464 | break; |
| 6465 | } |
| 6466 | |
| 6467 | cond_resched(); |
| 6468 | } |
| 6469 | |
| 6470 | return ret; |
| 6471 | } |
| 6472 | |
| 6473 | /* |
| 6474 | * Trim the whole filesystem by: |
| 6475 | * 1) trimming the free space in each block group |
| 6476 | * 2) trimming the unallocated space on each device |
| 6477 | * |
| 6478 | * This will also continue trimming even if a block group or device encounters |
| 6479 | * an error. The return value will be the last error, or 0 if nothing bad |
| 6480 | * happens. |
| 6481 | */ |
| 6482 | int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) |
| 6483 | { |
| 6484 | struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; |
| 6485 | struct btrfs_block_group *cache = NULL; |
| 6486 | struct btrfs_device *device; |
| 6487 | u64 group_trimmed; |
| 6488 | u64 range_end = U64_MAX; |
| 6489 | u64 start; |
| 6490 | u64 end; |
| 6491 | u64 trimmed = 0; |
| 6492 | u64 bg_failed = 0; |
| 6493 | u64 dev_failed = 0; |
| 6494 | int bg_ret = 0; |
| 6495 | int dev_ret = 0; |
| 6496 | int ret = 0; |
| 6497 | |
| 6498 | if (range->start == U64_MAX) |
| 6499 | return -EINVAL; |
| 6500 | |
| 6501 | /* |
| 6502 | * Check range overflow if range->len is set. |
| 6503 | * The default range->len is U64_MAX. |
| 6504 | */ |
| 6505 | if (range->len != U64_MAX && |
| 6506 | check_add_overflow(range->start, range->len, &range_end)) |
| 6507 | return -EINVAL; |
| 6508 | |
| 6509 | cache = btrfs_lookup_first_block_group(fs_info, range->start); |
| 6510 | for (; cache; cache = btrfs_next_block_group(cache)) { |
| 6511 | if (cache->start >= range_end) { |
| 6512 | btrfs_put_block_group(cache); |
| 6513 | break; |
| 6514 | } |
| 6515 | |
| 6516 | start = max(range->start, cache->start); |
| 6517 | end = min(range_end, cache->start + cache->length); |
| 6518 | |
| 6519 | if (end - start >= range->minlen) { |
| 6520 | if (!btrfs_block_group_done(cache)) { |
| 6521 | ret = btrfs_cache_block_group(cache, true); |
| 6522 | if (ret) { |
| 6523 | bg_failed++; |
| 6524 | bg_ret = ret; |
| 6525 | continue; |
| 6526 | } |
| 6527 | } |
| 6528 | ret = btrfs_trim_block_group(cache, |
| 6529 | &group_trimmed, |
| 6530 | start, |
| 6531 | end, |
| 6532 | range->minlen); |
| 6533 | |
| 6534 | trimmed += group_trimmed; |
| 6535 | if (ret) { |
| 6536 | bg_failed++; |
| 6537 | bg_ret = ret; |
| 6538 | continue; |
| 6539 | } |
| 6540 | } |
| 6541 | } |
| 6542 | |
| 6543 | if (bg_failed) |
| 6544 | btrfs_warn(fs_info, |
| 6545 | "failed to trim %llu block group(s), last error %d", |
| 6546 | bg_failed, bg_ret); |
| 6547 | |
| 6548 | mutex_lock(&fs_devices->device_list_mutex); |
| 6549 | list_for_each_entry(device, &fs_devices->devices, dev_list) { |
| 6550 | if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) |
| 6551 | continue; |
| 6552 | |
| 6553 | ret = btrfs_trim_free_extents(device, &group_trimmed); |
| 6554 | |
| 6555 | trimmed += group_trimmed; |
| 6556 | if (ret) { |
| 6557 | dev_failed++; |
| 6558 | dev_ret = ret; |
| 6559 | break; |
| 6560 | } |
| 6561 | } |
| 6562 | mutex_unlock(&fs_devices->device_list_mutex); |
| 6563 | |
| 6564 | if (dev_failed) |
| 6565 | btrfs_warn(fs_info, |
| 6566 | "failed to trim %llu device(s), last error %d", |
| 6567 | dev_failed, dev_ret); |
| 6568 | range->len = trimmed; |
| 6569 | if (bg_ret) |
| 6570 | return bg_ret; |
| 6571 | return dev_ret; |
| 6572 | } |