| 1 | /* |
| 2 | * Copyright (C) 2007 Oracle. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public |
| 6 | * License v2 as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 11 | * General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public |
| 14 | * License along with this program; if not, write to the |
| 15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 16 | * Boston, MA 021110-1307, USA. |
| 17 | */ |
| 18 | #include <linux/sched.h> |
| 19 | #include <linux/pagemap.h> |
| 20 | #include <linux/writeback.h> |
| 21 | #include "hash.h" |
| 22 | #include "crc32c.h" |
| 23 | #include "ctree.h" |
| 24 | #include "disk-io.h" |
| 25 | #include "print-tree.h" |
| 26 | #include "transaction.h" |
| 27 | #include "volumes.h" |
| 28 | #include "locking.h" |
| 29 | #include "ref-cache.h" |
| 30 | |
| 31 | #define BLOCK_GROUP_DATA EXTENT_WRITEBACK |
| 32 | #define BLOCK_GROUP_METADATA EXTENT_UPTODATE |
| 33 | #define BLOCK_GROUP_SYSTEM EXTENT_NEW |
| 34 | |
| 35 | #define BLOCK_GROUP_DIRTY EXTENT_DIRTY |
| 36 | |
| 37 | static int finish_current_insert(struct btrfs_trans_handle *trans, struct |
| 38 | btrfs_root *extent_root); |
| 39 | static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
| 40 | btrfs_root *extent_root); |
| 41 | static struct btrfs_block_group_cache * |
| 42 | __btrfs_find_block_group(struct btrfs_root *root, |
| 43 | struct btrfs_block_group_cache *hint, |
| 44 | u64 search_start, int data, int owner); |
| 45 | |
| 46 | void maybe_lock_mutex(struct btrfs_root *root) |
| 47 | { |
| 48 | if (root != root->fs_info->extent_root && |
| 49 | root != root->fs_info->chunk_root && |
| 50 | root != root->fs_info->dev_root) { |
| 51 | mutex_lock(&root->fs_info->alloc_mutex); |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | void maybe_unlock_mutex(struct btrfs_root *root) |
| 56 | { |
| 57 | if (root != root->fs_info->extent_root && |
| 58 | root != root->fs_info->chunk_root && |
| 59 | root != root->fs_info->dev_root) { |
| 60 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | static int cache_block_group(struct btrfs_root *root, |
| 65 | struct btrfs_block_group_cache *block_group) |
| 66 | { |
| 67 | struct btrfs_path *path; |
| 68 | int ret; |
| 69 | struct btrfs_key key; |
| 70 | struct extent_buffer *leaf; |
| 71 | struct extent_io_tree *free_space_cache; |
| 72 | int slot; |
| 73 | u64 last = 0; |
| 74 | u64 hole_size; |
| 75 | u64 first_free; |
| 76 | int found = 0; |
| 77 | |
| 78 | if (!block_group) |
| 79 | return 0; |
| 80 | |
| 81 | root = root->fs_info->extent_root; |
| 82 | free_space_cache = &root->fs_info->free_space_cache; |
| 83 | |
| 84 | if (block_group->cached) |
| 85 | return 0; |
| 86 | |
| 87 | path = btrfs_alloc_path(); |
| 88 | if (!path) |
| 89 | return -ENOMEM; |
| 90 | |
| 91 | path->reada = 2; |
| 92 | /* |
| 93 | * we get into deadlocks with paths held by callers of this function. |
| 94 | * since the alloc_mutex is protecting things right now, just |
| 95 | * skip the locking here |
| 96 | */ |
| 97 | path->skip_locking = 1; |
| 98 | first_free = block_group->key.objectid; |
| 99 | key.objectid = block_group->key.objectid; |
| 100 | key.offset = 0; |
| 101 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| 102 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 103 | if (ret < 0) |
| 104 | return ret; |
| 105 | ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); |
| 106 | if (ret < 0) |
| 107 | return ret; |
| 108 | if (ret == 0) { |
| 109 | leaf = path->nodes[0]; |
| 110 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 111 | if (key.objectid + key.offset > first_free) |
| 112 | first_free = key.objectid + key.offset; |
| 113 | } |
| 114 | while(1) { |
| 115 | leaf = path->nodes[0]; |
| 116 | slot = path->slots[0]; |
| 117 | if (slot >= btrfs_header_nritems(leaf)) { |
| 118 | ret = btrfs_next_leaf(root, path); |
| 119 | if (ret < 0) |
| 120 | goto err; |
| 121 | if (ret == 0) { |
| 122 | continue; |
| 123 | } else { |
| 124 | break; |
| 125 | } |
| 126 | } |
| 127 | btrfs_item_key_to_cpu(leaf, &key, slot); |
| 128 | if (key.objectid < block_group->key.objectid) { |
| 129 | goto next; |
| 130 | } |
| 131 | if (key.objectid >= block_group->key.objectid + |
| 132 | block_group->key.offset) { |
| 133 | break; |
| 134 | } |
| 135 | |
| 136 | if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) { |
| 137 | if (!found) { |
| 138 | last = first_free; |
| 139 | found = 1; |
| 140 | } |
| 141 | if (key.objectid > last) { |
| 142 | hole_size = key.objectid - last; |
| 143 | set_extent_dirty(free_space_cache, last, |
| 144 | last + hole_size - 1, |
| 145 | GFP_NOFS); |
| 146 | } |
| 147 | last = key.objectid + key.offset; |
| 148 | } |
| 149 | next: |
| 150 | path->slots[0]++; |
| 151 | } |
| 152 | |
| 153 | if (!found) |
| 154 | last = first_free; |
| 155 | if (block_group->key.objectid + |
| 156 | block_group->key.offset > last) { |
| 157 | hole_size = block_group->key.objectid + |
| 158 | block_group->key.offset - last; |
| 159 | set_extent_dirty(free_space_cache, last, |
| 160 | last + hole_size - 1, GFP_NOFS); |
| 161 | } |
| 162 | block_group->cached = 1; |
| 163 | err: |
| 164 | btrfs_free_path(path); |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct |
| 169 | btrfs_fs_info *info, |
| 170 | u64 bytenr) |
| 171 | { |
| 172 | struct extent_io_tree *block_group_cache; |
| 173 | struct btrfs_block_group_cache *block_group = NULL; |
| 174 | u64 ptr; |
| 175 | u64 start; |
| 176 | u64 end; |
| 177 | int ret; |
| 178 | |
| 179 | bytenr = max_t(u64, bytenr, |
| 180 | BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE); |
| 181 | block_group_cache = &info->block_group_cache; |
| 182 | ret = find_first_extent_bit(block_group_cache, |
| 183 | bytenr, &start, &end, |
| 184 | BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA | |
| 185 | BLOCK_GROUP_SYSTEM); |
| 186 | if (ret) { |
| 187 | return NULL; |
| 188 | } |
| 189 | ret = get_state_private(block_group_cache, start, &ptr); |
| 190 | if (ret) |
| 191 | return NULL; |
| 192 | |
| 193 | block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr; |
| 194 | return block_group; |
| 195 | } |
| 196 | |
| 197 | struct btrfs_block_group_cache *btrfs_lookup_block_group(struct |
| 198 | btrfs_fs_info *info, |
| 199 | u64 bytenr) |
| 200 | { |
| 201 | struct extent_io_tree *block_group_cache; |
| 202 | struct btrfs_block_group_cache *block_group = NULL; |
| 203 | u64 ptr; |
| 204 | u64 start; |
| 205 | u64 end; |
| 206 | int ret; |
| 207 | |
| 208 | bytenr = max_t(u64, bytenr, |
| 209 | BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE); |
| 210 | block_group_cache = &info->block_group_cache; |
| 211 | ret = find_first_extent_bit(block_group_cache, |
| 212 | bytenr, &start, &end, |
| 213 | BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA | |
| 214 | BLOCK_GROUP_SYSTEM); |
| 215 | if (ret) { |
| 216 | return NULL; |
| 217 | } |
| 218 | ret = get_state_private(block_group_cache, start, &ptr); |
| 219 | if (ret) |
| 220 | return NULL; |
| 221 | |
| 222 | block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr; |
| 223 | if (block_group->key.objectid <= bytenr && bytenr < |
| 224 | block_group->key.objectid + block_group->key.offset) |
| 225 | return block_group; |
| 226 | return NULL; |
| 227 | } |
| 228 | |
| 229 | static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) |
| 230 | { |
| 231 | return (cache->flags & bits) == bits; |
| 232 | } |
| 233 | |
| 234 | static int noinline find_search_start(struct btrfs_root *root, |
| 235 | struct btrfs_block_group_cache **cache_ret, |
| 236 | u64 *start_ret, u64 num, int data) |
| 237 | { |
| 238 | int ret; |
| 239 | struct btrfs_block_group_cache *cache = *cache_ret; |
| 240 | struct extent_io_tree *free_space_cache; |
| 241 | struct extent_state *state; |
| 242 | u64 last; |
| 243 | u64 start = 0; |
| 244 | u64 cache_miss = 0; |
| 245 | u64 total_fs_bytes; |
| 246 | u64 search_start = *start_ret; |
| 247 | int wrapped = 0; |
| 248 | |
| 249 | WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); |
| 250 | total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); |
| 251 | free_space_cache = &root->fs_info->free_space_cache; |
| 252 | |
| 253 | if (!cache) |
| 254 | goto out; |
| 255 | |
| 256 | again: |
| 257 | ret = cache_block_group(root, cache); |
| 258 | if (ret) { |
| 259 | goto out; |
| 260 | } |
| 261 | |
| 262 | last = max(search_start, cache->key.objectid); |
| 263 | if (!block_group_bits(cache, data) || cache->ro) |
| 264 | goto new_group; |
| 265 | |
| 266 | spin_lock_irq(&free_space_cache->lock); |
| 267 | state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY); |
| 268 | while(1) { |
| 269 | if (!state) { |
| 270 | if (!cache_miss) |
| 271 | cache_miss = last; |
| 272 | spin_unlock_irq(&free_space_cache->lock); |
| 273 | goto new_group; |
| 274 | } |
| 275 | |
| 276 | start = max(last, state->start); |
| 277 | last = state->end + 1; |
| 278 | if (last - start < num) { |
| 279 | do { |
| 280 | state = extent_state_next(state); |
| 281 | } while(state && !(state->state & EXTENT_DIRTY)); |
| 282 | continue; |
| 283 | } |
| 284 | spin_unlock_irq(&free_space_cache->lock); |
| 285 | if (cache->ro) { |
| 286 | goto new_group; |
| 287 | } |
| 288 | if (start + num > cache->key.objectid + cache->key.offset) |
| 289 | goto new_group; |
| 290 | if (!block_group_bits(cache, data)) { |
| 291 | printk("block group bits don't match %Lu %d\n", cache->flags, data); |
| 292 | } |
| 293 | *start_ret = start; |
| 294 | return 0; |
| 295 | } |
| 296 | out: |
| 297 | cache = btrfs_lookup_block_group(root->fs_info, search_start); |
| 298 | if (!cache) { |
| 299 | printk("Unable to find block group for %Lu\n", search_start); |
| 300 | WARN_ON(1); |
| 301 | } |
| 302 | return -ENOSPC; |
| 303 | |
| 304 | new_group: |
| 305 | last = cache->key.objectid + cache->key.offset; |
| 306 | wrapped: |
| 307 | cache = btrfs_lookup_first_block_group(root->fs_info, last); |
| 308 | if (!cache || cache->key.objectid >= total_fs_bytes) { |
| 309 | no_cache: |
| 310 | if (!wrapped) { |
| 311 | wrapped = 1; |
| 312 | last = search_start; |
| 313 | goto wrapped; |
| 314 | } |
| 315 | goto out; |
| 316 | } |
| 317 | if (cache_miss && !cache->cached) { |
| 318 | cache_block_group(root, cache); |
| 319 | last = cache_miss; |
| 320 | cache = btrfs_lookup_first_block_group(root->fs_info, last); |
| 321 | } |
| 322 | cache_miss = 0; |
| 323 | cache = btrfs_find_block_group(root, cache, last, data, 0); |
| 324 | if (!cache) |
| 325 | goto no_cache; |
| 326 | *cache_ret = cache; |
| 327 | goto again; |
| 328 | } |
| 329 | |
| 330 | static u64 div_factor(u64 num, int factor) |
| 331 | { |
| 332 | if (factor == 10) |
| 333 | return num; |
| 334 | num *= factor; |
| 335 | do_div(num, 10); |
| 336 | return num; |
| 337 | } |
| 338 | |
| 339 | static int block_group_state_bits(u64 flags) |
| 340 | { |
| 341 | int bits = 0; |
| 342 | if (flags & BTRFS_BLOCK_GROUP_DATA) |
| 343 | bits |= BLOCK_GROUP_DATA; |
| 344 | if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| 345 | bits |= BLOCK_GROUP_METADATA; |
| 346 | if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| 347 | bits |= BLOCK_GROUP_SYSTEM; |
| 348 | return bits; |
| 349 | } |
| 350 | |
| 351 | static struct btrfs_block_group_cache * |
| 352 | __btrfs_find_block_group(struct btrfs_root *root, |
| 353 | struct btrfs_block_group_cache *hint, |
| 354 | u64 search_start, int data, int owner) |
| 355 | { |
| 356 | struct btrfs_block_group_cache *cache; |
| 357 | struct extent_io_tree *block_group_cache; |
| 358 | struct btrfs_block_group_cache *found_group = NULL; |
| 359 | struct btrfs_fs_info *info = root->fs_info; |
| 360 | u64 used; |
| 361 | u64 last = 0; |
| 362 | u64 start; |
| 363 | u64 end; |
| 364 | u64 free_check; |
| 365 | u64 ptr; |
| 366 | int bit; |
| 367 | int ret; |
| 368 | int full_search = 0; |
| 369 | int factor = 10; |
| 370 | int wrapped = 0; |
| 371 | |
| 372 | block_group_cache = &info->block_group_cache; |
| 373 | |
| 374 | if (data & BTRFS_BLOCK_GROUP_METADATA) |
| 375 | factor = 9; |
| 376 | |
| 377 | bit = block_group_state_bits(data); |
| 378 | |
| 379 | if (search_start) { |
| 380 | struct btrfs_block_group_cache *shint; |
| 381 | shint = btrfs_lookup_first_block_group(info, search_start); |
| 382 | if (shint && block_group_bits(shint, data) && !shint->ro) { |
| 383 | spin_lock(&shint->lock); |
| 384 | used = btrfs_block_group_used(&shint->item); |
| 385 | if (used + shint->pinned < |
| 386 | div_factor(shint->key.offset, factor)) { |
| 387 | spin_unlock(&shint->lock); |
| 388 | return shint; |
| 389 | } |
| 390 | spin_unlock(&shint->lock); |
| 391 | } |
| 392 | } |
| 393 | if (hint && !hint->ro && block_group_bits(hint, data)) { |
| 394 | spin_lock(&hint->lock); |
| 395 | used = btrfs_block_group_used(&hint->item); |
| 396 | if (used + hint->pinned < |
| 397 | div_factor(hint->key.offset, factor)) { |
| 398 | spin_unlock(&hint->lock); |
| 399 | return hint; |
| 400 | } |
| 401 | spin_unlock(&hint->lock); |
| 402 | last = hint->key.objectid + hint->key.offset; |
| 403 | } else { |
| 404 | if (hint) |
| 405 | last = max(hint->key.objectid, search_start); |
| 406 | else |
| 407 | last = search_start; |
| 408 | } |
| 409 | again: |
| 410 | while(1) { |
| 411 | ret = find_first_extent_bit(block_group_cache, last, |
| 412 | &start, &end, bit); |
| 413 | if (ret) |
| 414 | break; |
| 415 | |
| 416 | ret = get_state_private(block_group_cache, start, &ptr); |
| 417 | if (ret) { |
| 418 | last = end + 1; |
| 419 | continue; |
| 420 | } |
| 421 | |
| 422 | cache = (struct btrfs_block_group_cache *)(unsigned long)ptr; |
| 423 | spin_lock(&cache->lock); |
| 424 | last = cache->key.objectid + cache->key.offset; |
| 425 | used = btrfs_block_group_used(&cache->item); |
| 426 | |
| 427 | if (!cache->ro && block_group_bits(cache, data)) { |
| 428 | free_check = div_factor(cache->key.offset, factor); |
| 429 | if (used + cache->pinned < free_check) { |
| 430 | found_group = cache; |
| 431 | spin_unlock(&cache->lock); |
| 432 | goto found; |
| 433 | } |
| 434 | } |
| 435 | spin_unlock(&cache->lock); |
| 436 | cond_resched(); |
| 437 | } |
| 438 | if (!wrapped) { |
| 439 | last = search_start; |
| 440 | wrapped = 1; |
| 441 | goto again; |
| 442 | } |
| 443 | if (!full_search && factor < 10) { |
| 444 | last = search_start; |
| 445 | full_search = 1; |
| 446 | factor = 10; |
| 447 | goto again; |
| 448 | } |
| 449 | found: |
| 450 | return found_group; |
| 451 | } |
| 452 | |
| 453 | struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root, |
| 454 | struct btrfs_block_group_cache |
| 455 | *hint, u64 search_start, |
| 456 | int data, int owner) |
| 457 | { |
| 458 | |
| 459 | struct btrfs_block_group_cache *ret; |
| 460 | ret = __btrfs_find_block_group(root, hint, search_start, data, owner); |
| 461 | return ret; |
| 462 | } |
| 463 | static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation, |
| 464 | u64 owner, u64 owner_offset) |
| 465 | { |
| 466 | u32 high_crc = ~(u32)0; |
| 467 | u32 low_crc = ~(u32)0; |
| 468 | __le64 lenum; |
| 469 | lenum = cpu_to_le64(root_objectid); |
| 470 | high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum)); |
| 471 | lenum = cpu_to_le64(ref_generation); |
| 472 | low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); |
| 473 | if (owner >= BTRFS_FIRST_FREE_OBJECTID) { |
| 474 | lenum = cpu_to_le64(owner); |
| 475 | low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); |
| 476 | lenum = cpu_to_le64(owner_offset); |
| 477 | low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); |
| 478 | } |
| 479 | return ((u64)high_crc << 32) | (u64)low_crc; |
| 480 | } |
| 481 | |
| 482 | static int match_extent_ref(struct extent_buffer *leaf, |
| 483 | struct btrfs_extent_ref *disk_ref, |
| 484 | struct btrfs_extent_ref *cpu_ref) |
| 485 | { |
| 486 | int ret; |
| 487 | int len; |
| 488 | |
| 489 | if (cpu_ref->objectid) |
| 490 | len = sizeof(*cpu_ref); |
| 491 | else |
| 492 | len = 2 * sizeof(u64); |
| 493 | ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref, |
| 494 | len); |
| 495 | return ret == 0; |
| 496 | } |
| 497 | |
| 498 | static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans, |
| 499 | struct btrfs_root *root, |
| 500 | struct btrfs_path *path, u64 bytenr, |
| 501 | u64 root_objectid, |
| 502 | u64 ref_generation, u64 owner, |
| 503 | u64 owner_offset, int del) |
| 504 | { |
| 505 | u64 hash; |
| 506 | struct btrfs_key key; |
| 507 | struct btrfs_key found_key; |
| 508 | struct btrfs_extent_ref ref; |
| 509 | struct extent_buffer *leaf; |
| 510 | struct btrfs_extent_ref *disk_ref; |
| 511 | int ret; |
| 512 | int ret2; |
| 513 | |
| 514 | btrfs_set_stack_ref_root(&ref, root_objectid); |
| 515 | btrfs_set_stack_ref_generation(&ref, ref_generation); |
| 516 | btrfs_set_stack_ref_objectid(&ref, owner); |
| 517 | btrfs_set_stack_ref_offset(&ref, owner_offset); |
| 518 | |
| 519 | hash = hash_extent_ref(root_objectid, ref_generation, owner, |
| 520 | owner_offset); |
| 521 | key.offset = hash; |
| 522 | key.objectid = bytenr; |
| 523 | key.type = BTRFS_EXTENT_REF_KEY; |
| 524 | |
| 525 | while (1) { |
| 526 | ret = btrfs_search_slot(trans, root, &key, path, |
| 527 | del ? -1 : 0, del); |
| 528 | if (ret < 0) |
| 529 | goto out; |
| 530 | leaf = path->nodes[0]; |
| 531 | if (ret != 0) { |
| 532 | u32 nritems = btrfs_header_nritems(leaf); |
| 533 | if (path->slots[0] >= nritems) { |
| 534 | ret2 = btrfs_next_leaf(root, path); |
| 535 | if (ret2) |
| 536 | goto out; |
| 537 | leaf = path->nodes[0]; |
| 538 | } |
| 539 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 540 | if (found_key.objectid != bytenr || |
| 541 | found_key.type != BTRFS_EXTENT_REF_KEY) |
| 542 | goto out; |
| 543 | key.offset = found_key.offset; |
| 544 | if (del) { |
| 545 | btrfs_release_path(root, path); |
| 546 | continue; |
| 547 | } |
| 548 | } |
| 549 | disk_ref = btrfs_item_ptr(path->nodes[0], |
| 550 | path->slots[0], |
| 551 | struct btrfs_extent_ref); |
| 552 | if (match_extent_ref(path->nodes[0], disk_ref, &ref)) { |
| 553 | ret = 0; |
| 554 | goto out; |
| 555 | } |
| 556 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 557 | key.offset = found_key.offset + 1; |
| 558 | btrfs_release_path(root, path); |
| 559 | } |
| 560 | out: |
| 561 | return ret; |
| 562 | } |
| 563 | |
| 564 | /* |
| 565 | * Back reference rules. Back refs have three main goals: |
| 566 | * |
| 567 | * 1) differentiate between all holders of references to an extent so that |
| 568 | * when a reference is dropped we can make sure it was a valid reference |
| 569 | * before freeing the extent. |
| 570 | * |
| 571 | * 2) Provide enough information to quickly find the holders of an extent |
| 572 | * if we notice a given block is corrupted or bad. |
| 573 | * |
| 574 | * 3) Make it easy to migrate blocks for FS shrinking or storage pool |
| 575 | * maintenance. This is actually the same as #2, but with a slightly |
| 576 | * different use case. |
| 577 | * |
| 578 | * File extents can be referenced by: |
| 579 | * |
| 580 | * - multiple snapshots, subvolumes, or different generations in one subvol |
| 581 | * - different files inside a single subvolume (in theory, not implemented yet) |
| 582 | * - different offsets inside a file (bookend extents in file.c) |
| 583 | * |
| 584 | * The extent ref structure has fields for: |
| 585 | * |
| 586 | * - Objectid of the subvolume root |
| 587 | * - Generation number of the tree holding the reference |
| 588 | * - objectid of the file holding the reference |
| 589 | * - offset in the file corresponding to the key holding the reference |
| 590 | * |
| 591 | * When a file extent is allocated the fields are filled in: |
| 592 | * (root_key.objectid, trans->transid, inode objectid, offset in file) |
| 593 | * |
| 594 | * When a leaf is cow'd new references are added for every file extent found |
| 595 | * in the leaf. It looks the same as the create case, but trans->transid |
| 596 | * will be different when the block is cow'd. |
| 597 | * |
| 598 | * (root_key.objectid, trans->transid, inode objectid, offset in file) |
| 599 | * |
| 600 | * When a file extent is removed either during snapshot deletion or file |
| 601 | * truncation, the corresponding back reference is found |
| 602 | * by searching for: |
| 603 | * |
| 604 | * (btrfs_header_owner(leaf), btrfs_header_generation(leaf), |
| 605 | * inode objectid, offset in file) |
| 606 | * |
| 607 | * Btree extents can be referenced by: |
| 608 | * |
| 609 | * - Different subvolumes |
| 610 | * - Different generations of the same subvolume |
| 611 | * |
| 612 | * Storing sufficient information for a full reverse mapping of a btree |
| 613 | * block would require storing the lowest key of the block in the backref, |
| 614 | * and it would require updating that lowest key either before write out or |
| 615 | * every time it changed. Instead, the objectid of the lowest key is stored |
| 616 | * along with the level of the tree block. This provides a hint |
| 617 | * about where in the btree the block can be found. Searches through the |
| 618 | * btree only need to look for a pointer to that block, so they stop one |
| 619 | * level higher than the level recorded in the backref. |
| 620 | * |
| 621 | * Some btrees do not do reference counting on their extents. These |
| 622 | * include the extent tree and the tree of tree roots. Backrefs for these |
| 623 | * trees always have a generation of zero. |
| 624 | * |
| 625 | * When a tree block is created, back references are inserted: |
| 626 | * |
| 627 | * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid) |
| 628 | * |
| 629 | * When a tree block is cow'd in a reference counted root, |
| 630 | * new back references are added for all the blocks it points to. |
| 631 | * These are of the form (trans->transid will have increased since creation): |
| 632 | * |
| 633 | * (root->root_key.objectid, trans->transid, level, lowest_key_objectid) |
| 634 | * |
| 635 | * Because the lowest_key_objectid and the level are just hints |
| 636 | * they are not used when backrefs are deleted. When a backref is deleted: |
| 637 | * |
| 638 | * if backref was for a tree root: |
| 639 | * root_objectid = root->root_key.objectid |
| 640 | * else |
| 641 | * root_objectid = btrfs_header_owner(parent) |
| 642 | * |
| 643 | * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0) |
| 644 | * |
| 645 | * Back Reference Key hashing: |
| 646 | * |
| 647 | * Back references have four fields, each 64 bits long. Unfortunately, |
| 648 | * This is hashed into a single 64 bit number and placed into the key offset. |
| 649 | * The key objectid corresponds to the first byte in the extent, and the |
| 650 | * key type is set to BTRFS_EXTENT_REF_KEY |
| 651 | */ |
| 652 | int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans, |
| 653 | struct btrfs_root *root, |
| 654 | struct btrfs_path *path, u64 bytenr, |
| 655 | u64 root_objectid, u64 ref_generation, |
| 656 | u64 owner, u64 owner_offset) |
| 657 | { |
| 658 | u64 hash; |
| 659 | struct btrfs_key key; |
| 660 | struct btrfs_extent_ref ref; |
| 661 | struct btrfs_extent_ref *disk_ref; |
| 662 | int ret; |
| 663 | |
| 664 | btrfs_set_stack_ref_root(&ref, root_objectid); |
| 665 | btrfs_set_stack_ref_generation(&ref, ref_generation); |
| 666 | btrfs_set_stack_ref_objectid(&ref, owner); |
| 667 | btrfs_set_stack_ref_offset(&ref, owner_offset); |
| 668 | |
| 669 | hash = hash_extent_ref(root_objectid, ref_generation, owner, |
| 670 | owner_offset); |
| 671 | key.offset = hash; |
| 672 | key.objectid = bytenr; |
| 673 | key.type = BTRFS_EXTENT_REF_KEY; |
| 674 | |
| 675 | ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref)); |
| 676 | while (ret == -EEXIST) { |
| 677 | disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| 678 | struct btrfs_extent_ref); |
| 679 | if (match_extent_ref(path->nodes[0], disk_ref, &ref)) |
| 680 | goto out; |
| 681 | key.offset++; |
| 682 | btrfs_release_path(root, path); |
| 683 | ret = btrfs_insert_empty_item(trans, root, path, &key, |
| 684 | sizeof(ref)); |
| 685 | } |
| 686 | if (ret) |
| 687 | goto out; |
| 688 | disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| 689 | struct btrfs_extent_ref); |
| 690 | write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref, |
| 691 | sizeof(ref)); |
| 692 | btrfs_mark_buffer_dirty(path->nodes[0]); |
| 693 | out: |
| 694 | btrfs_release_path(root, path); |
| 695 | return ret; |
| 696 | } |
| 697 | |
| 698 | static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
| 699 | struct btrfs_root *root, |
| 700 | u64 bytenr, u64 num_bytes, |
| 701 | u64 root_objectid, u64 ref_generation, |
| 702 | u64 owner, u64 owner_offset) |
| 703 | { |
| 704 | struct btrfs_path *path; |
| 705 | int ret; |
| 706 | struct btrfs_key key; |
| 707 | struct extent_buffer *l; |
| 708 | struct btrfs_extent_item *item; |
| 709 | u32 refs; |
| 710 | |
| 711 | WARN_ON(num_bytes < root->sectorsize); |
| 712 | path = btrfs_alloc_path(); |
| 713 | if (!path) |
| 714 | return -ENOMEM; |
| 715 | |
| 716 | path->reada = 1; |
| 717 | key.objectid = bytenr; |
| 718 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| 719 | key.offset = num_bytes; |
| 720 | ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
| 721 | 0, 1); |
| 722 | if (ret < 0) |
| 723 | return ret; |
| 724 | if (ret != 0) { |
| 725 | BUG(); |
| 726 | } |
| 727 | BUG_ON(ret != 0); |
| 728 | l = path->nodes[0]; |
| 729 | item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); |
| 730 | refs = btrfs_extent_refs(l, item); |
| 731 | btrfs_set_extent_refs(l, item, refs + 1); |
| 732 | btrfs_mark_buffer_dirty(path->nodes[0]); |
| 733 | |
| 734 | btrfs_release_path(root->fs_info->extent_root, path); |
| 735 | |
| 736 | path->reada = 1; |
| 737 | ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root, |
| 738 | path, bytenr, root_objectid, |
| 739 | ref_generation, owner, owner_offset); |
| 740 | BUG_ON(ret); |
| 741 | finish_current_insert(trans, root->fs_info->extent_root); |
| 742 | del_pending_extents(trans, root->fs_info->extent_root); |
| 743 | |
| 744 | btrfs_free_path(path); |
| 745 | return 0; |
| 746 | } |
| 747 | |
| 748 | int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
| 749 | struct btrfs_root *root, |
| 750 | u64 bytenr, u64 num_bytes, |
| 751 | u64 root_objectid, u64 ref_generation, |
| 752 | u64 owner, u64 owner_offset) |
| 753 | { |
| 754 | int ret; |
| 755 | |
| 756 | mutex_lock(&root->fs_info->alloc_mutex); |
| 757 | ret = __btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, |
| 758 | root_objectid, ref_generation, |
| 759 | owner, owner_offset); |
| 760 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 761 | return ret; |
| 762 | } |
| 763 | |
| 764 | int btrfs_extent_post_op(struct btrfs_trans_handle *trans, |
| 765 | struct btrfs_root *root) |
| 766 | { |
| 767 | finish_current_insert(trans, root->fs_info->extent_root); |
| 768 | del_pending_extents(trans, root->fs_info->extent_root); |
| 769 | return 0; |
| 770 | } |
| 771 | |
| 772 | static int lookup_extent_ref(struct btrfs_trans_handle *trans, |
| 773 | struct btrfs_root *root, u64 bytenr, |
| 774 | u64 num_bytes, u32 *refs) |
| 775 | { |
| 776 | struct btrfs_path *path; |
| 777 | int ret; |
| 778 | struct btrfs_key key; |
| 779 | struct extent_buffer *l; |
| 780 | struct btrfs_extent_item *item; |
| 781 | |
| 782 | WARN_ON(num_bytes < root->sectorsize); |
| 783 | path = btrfs_alloc_path(); |
| 784 | path->reada = 1; |
| 785 | key.objectid = bytenr; |
| 786 | key.offset = num_bytes; |
| 787 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| 788 | ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
| 789 | 0, 0); |
| 790 | if (ret < 0) |
| 791 | goto out; |
| 792 | if (ret != 0) { |
| 793 | btrfs_print_leaf(root, path->nodes[0]); |
| 794 | printk("failed to find block number %Lu\n", bytenr); |
| 795 | BUG(); |
| 796 | } |
| 797 | l = path->nodes[0]; |
| 798 | item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); |
| 799 | *refs = btrfs_extent_refs(l, item); |
| 800 | out: |
| 801 | btrfs_free_path(path); |
| 802 | return 0; |
| 803 | } |
| 804 | |
| 805 | |
| 806 | static int get_reference_status(struct btrfs_root *root, u64 bytenr, |
| 807 | u64 parent_gen, u64 ref_objectid, |
| 808 | u64 *min_generation, u32 *ref_count) |
| 809 | { |
| 810 | struct btrfs_root *extent_root = root->fs_info->extent_root; |
| 811 | struct btrfs_path *path; |
| 812 | struct extent_buffer *leaf; |
| 813 | struct btrfs_extent_ref *ref_item; |
| 814 | struct btrfs_key key; |
| 815 | struct btrfs_key found_key; |
| 816 | u64 root_objectid = root->root_key.objectid; |
| 817 | u64 ref_generation; |
| 818 | u32 nritems; |
| 819 | int ret; |
| 820 | |
| 821 | key.objectid = bytenr; |
| 822 | key.offset = 0; |
| 823 | key.type = BTRFS_EXTENT_ITEM_KEY; |
| 824 | |
| 825 | path = btrfs_alloc_path(); |
| 826 | mutex_lock(&root->fs_info->alloc_mutex); |
| 827 | ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| 828 | if (ret < 0) |
| 829 | goto out; |
| 830 | BUG_ON(ret == 0); |
| 831 | |
| 832 | leaf = path->nodes[0]; |
| 833 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 834 | |
| 835 | if (found_key.objectid != bytenr || |
| 836 | found_key.type != BTRFS_EXTENT_ITEM_KEY) { |
| 837 | ret = 1; |
| 838 | goto out; |
| 839 | } |
| 840 | |
| 841 | *ref_count = 0; |
| 842 | *min_generation = (u64)-1; |
| 843 | |
| 844 | while (1) { |
| 845 | leaf = path->nodes[0]; |
| 846 | nritems = btrfs_header_nritems(leaf); |
| 847 | if (path->slots[0] >= nritems) { |
| 848 | ret = btrfs_next_leaf(extent_root, path); |
| 849 | if (ret < 0) |
| 850 | goto out; |
| 851 | if (ret == 0) |
| 852 | continue; |
| 853 | break; |
| 854 | } |
| 855 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 856 | if (found_key.objectid != bytenr) |
| 857 | break; |
| 858 | |
| 859 | if (found_key.type != BTRFS_EXTENT_REF_KEY) { |
| 860 | path->slots[0]++; |
| 861 | continue; |
| 862 | } |
| 863 | |
| 864 | ref_item = btrfs_item_ptr(leaf, path->slots[0], |
| 865 | struct btrfs_extent_ref); |
| 866 | ref_generation = btrfs_ref_generation(leaf, ref_item); |
| 867 | /* |
| 868 | * For (parent_gen > 0 && parent_gen > ref_gen): |
| 869 | * |
| 870 | * we reach here through the oldest root, therefore |
| 871 | * all other reference from same snapshot should have |
| 872 | * a larger generation. |
| 873 | */ |
| 874 | if ((root_objectid != btrfs_ref_root(leaf, ref_item)) || |
| 875 | (parent_gen > 0 && parent_gen > ref_generation) || |
| 876 | (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID && |
| 877 | ref_objectid != btrfs_ref_objectid(leaf, ref_item))) { |
| 878 | if (ref_count) |
| 879 | *ref_count = 2; |
| 880 | break; |
| 881 | } |
| 882 | |
| 883 | *ref_count = 1; |
| 884 | if (*min_generation > ref_generation) |
| 885 | *min_generation = ref_generation; |
| 886 | |
| 887 | path->slots[0]++; |
| 888 | } |
| 889 | ret = 0; |
| 890 | out: |
| 891 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 892 | btrfs_free_path(path); |
| 893 | return ret; |
| 894 | } |
| 895 | |
| 896 | int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans, |
| 897 | struct btrfs_root *root, |
| 898 | struct btrfs_key *key, u64 bytenr) |
| 899 | { |
| 900 | struct btrfs_root *old_root; |
| 901 | struct btrfs_path *path = NULL; |
| 902 | struct extent_buffer *eb; |
| 903 | struct btrfs_file_extent_item *item; |
| 904 | u64 ref_generation; |
| 905 | u64 min_generation; |
| 906 | u64 extent_start; |
| 907 | u32 ref_count; |
| 908 | int level; |
| 909 | int ret; |
| 910 | |
| 911 | BUG_ON(trans == NULL); |
| 912 | BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY); |
| 913 | ret = get_reference_status(root, bytenr, 0, key->objectid, |
| 914 | &min_generation, &ref_count); |
| 915 | if (ret) |
| 916 | return ret; |
| 917 | |
| 918 | if (ref_count != 1) |
| 919 | return 1; |
| 920 | |
| 921 | old_root = root->dirty_root->root; |
| 922 | ref_generation = old_root->root_key.offset; |
| 923 | |
| 924 | /* all references are created in running transaction */ |
| 925 | if (min_generation > ref_generation) { |
| 926 | ret = 0; |
| 927 | goto out; |
| 928 | } |
| 929 | |
| 930 | path = btrfs_alloc_path(); |
| 931 | if (!path) { |
| 932 | ret = -ENOMEM; |
| 933 | goto out; |
| 934 | } |
| 935 | |
| 936 | path->skip_locking = 1; |
| 937 | /* if no item found, the extent is referenced by other snapshot */ |
| 938 | ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0); |
| 939 | if (ret) |
| 940 | goto out; |
| 941 | |
| 942 | eb = path->nodes[0]; |
| 943 | item = btrfs_item_ptr(eb, path->slots[0], |
| 944 | struct btrfs_file_extent_item); |
| 945 | if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG || |
| 946 | btrfs_file_extent_disk_bytenr(eb, item) != bytenr) { |
| 947 | ret = 1; |
| 948 | goto out; |
| 949 | } |
| 950 | |
| 951 | for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) { |
| 952 | if (level >= 0) { |
| 953 | eb = path->nodes[level]; |
| 954 | if (!eb) |
| 955 | continue; |
| 956 | extent_start = eb->start; |
| 957 | } else |
| 958 | extent_start = bytenr; |
| 959 | |
| 960 | ret = get_reference_status(root, extent_start, ref_generation, |
| 961 | 0, &min_generation, &ref_count); |
| 962 | if (ret) |
| 963 | goto out; |
| 964 | |
| 965 | if (ref_count != 1) { |
| 966 | ret = 1; |
| 967 | goto out; |
| 968 | } |
| 969 | if (level >= 0) |
| 970 | ref_generation = btrfs_header_generation(eb); |
| 971 | } |
| 972 | ret = 0; |
| 973 | out: |
| 974 | if (path) |
| 975 | btrfs_free_path(path); |
| 976 | return ret; |
| 977 | } |
| 978 | |
| 979 | int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| 980 | struct extent_buffer *buf, int cache_ref) |
| 981 | { |
| 982 | u64 bytenr; |
| 983 | u32 nritems; |
| 984 | struct btrfs_key key; |
| 985 | struct btrfs_file_extent_item *fi; |
| 986 | int i; |
| 987 | int level; |
| 988 | int ret; |
| 989 | int faili; |
| 990 | int nr_file_extents = 0; |
| 991 | |
| 992 | if (!root->ref_cows) |
| 993 | return 0; |
| 994 | |
| 995 | level = btrfs_header_level(buf); |
| 996 | nritems = btrfs_header_nritems(buf); |
| 997 | for (i = 0; i < nritems; i++) { |
| 998 | cond_resched(); |
| 999 | if (level == 0) { |
| 1000 | u64 disk_bytenr; |
| 1001 | btrfs_item_key_to_cpu(buf, &key, i); |
| 1002 | if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) |
| 1003 | continue; |
| 1004 | fi = btrfs_item_ptr(buf, i, |
| 1005 | struct btrfs_file_extent_item); |
| 1006 | if (btrfs_file_extent_type(buf, fi) == |
| 1007 | BTRFS_FILE_EXTENT_INLINE) |
| 1008 | continue; |
| 1009 | disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); |
| 1010 | if (disk_bytenr == 0) |
| 1011 | continue; |
| 1012 | |
| 1013 | if (buf != root->commit_root) |
| 1014 | nr_file_extents++; |
| 1015 | |
| 1016 | mutex_lock(&root->fs_info->alloc_mutex); |
| 1017 | ret = __btrfs_inc_extent_ref(trans, root, disk_bytenr, |
| 1018 | btrfs_file_extent_disk_num_bytes(buf, fi), |
| 1019 | root->root_key.objectid, trans->transid, |
| 1020 | key.objectid, key.offset); |
| 1021 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 1022 | if (ret) { |
| 1023 | faili = i; |
| 1024 | WARN_ON(1); |
| 1025 | goto fail; |
| 1026 | } |
| 1027 | } else { |
| 1028 | bytenr = btrfs_node_blockptr(buf, i); |
| 1029 | btrfs_node_key_to_cpu(buf, &key, i); |
| 1030 | |
| 1031 | mutex_lock(&root->fs_info->alloc_mutex); |
| 1032 | ret = __btrfs_inc_extent_ref(trans, root, bytenr, |
| 1033 | btrfs_level_size(root, level - 1), |
| 1034 | root->root_key.objectid, |
| 1035 | trans->transid, |
| 1036 | level - 1, key.objectid); |
| 1037 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 1038 | if (ret) { |
| 1039 | faili = i; |
| 1040 | WARN_ON(1); |
| 1041 | goto fail; |
| 1042 | } |
| 1043 | } |
| 1044 | } |
| 1045 | /* cache orignal leaf block's references */ |
| 1046 | if (level == 0 && cache_ref && buf != root->commit_root) { |
| 1047 | struct btrfs_leaf_ref *ref; |
| 1048 | struct btrfs_extent_info *info; |
| 1049 | |
| 1050 | ref = btrfs_alloc_leaf_ref(root, nr_file_extents); |
| 1051 | if (!ref) { |
| 1052 | WARN_ON(1); |
| 1053 | goto out; |
| 1054 | } |
| 1055 | |
| 1056 | ref->root_gen = root->root_key.offset; |
| 1057 | ref->bytenr = buf->start; |
| 1058 | ref->owner = btrfs_header_owner(buf); |
| 1059 | ref->generation = btrfs_header_generation(buf); |
| 1060 | ref->nritems = nr_file_extents; |
| 1061 | info = ref->extents; |
| 1062 | |
| 1063 | for (i = 0; nr_file_extents > 0 && i < nritems; i++) { |
| 1064 | u64 disk_bytenr; |
| 1065 | btrfs_item_key_to_cpu(buf, &key, i); |
| 1066 | if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) |
| 1067 | continue; |
| 1068 | fi = btrfs_item_ptr(buf, i, |
| 1069 | struct btrfs_file_extent_item); |
| 1070 | if (btrfs_file_extent_type(buf, fi) == |
| 1071 | BTRFS_FILE_EXTENT_INLINE) |
| 1072 | continue; |
| 1073 | disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); |
| 1074 | if (disk_bytenr == 0) |
| 1075 | continue; |
| 1076 | |
| 1077 | info->bytenr = disk_bytenr; |
| 1078 | info->num_bytes = |
| 1079 | btrfs_file_extent_disk_num_bytes(buf, fi); |
| 1080 | info->objectid = key.objectid; |
| 1081 | info->offset = key.offset; |
| 1082 | info++; |
| 1083 | } |
| 1084 | |
| 1085 | BUG_ON(!root->ref_tree); |
| 1086 | ret = btrfs_add_leaf_ref(root, ref); |
| 1087 | WARN_ON(ret); |
| 1088 | btrfs_free_leaf_ref(root, ref); |
| 1089 | } |
| 1090 | out: |
| 1091 | return 0; |
| 1092 | fail: |
| 1093 | WARN_ON(1); |
| 1094 | #if 0 |
| 1095 | for (i =0; i < faili; i++) { |
| 1096 | if (level == 0) { |
| 1097 | u64 disk_bytenr; |
| 1098 | btrfs_item_key_to_cpu(buf, &key, i); |
| 1099 | if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) |
| 1100 | continue; |
| 1101 | fi = btrfs_item_ptr(buf, i, |
| 1102 | struct btrfs_file_extent_item); |
| 1103 | if (btrfs_file_extent_type(buf, fi) == |
| 1104 | BTRFS_FILE_EXTENT_INLINE) |
| 1105 | continue; |
| 1106 | disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); |
| 1107 | if (disk_bytenr == 0) |
| 1108 | continue; |
| 1109 | err = btrfs_free_extent(trans, root, disk_bytenr, |
| 1110 | btrfs_file_extent_disk_num_bytes(buf, |
| 1111 | fi), 0); |
| 1112 | BUG_ON(err); |
| 1113 | } else { |
| 1114 | bytenr = btrfs_node_blockptr(buf, i); |
| 1115 | err = btrfs_free_extent(trans, root, bytenr, |
| 1116 | btrfs_level_size(root, level - 1), 0); |
| 1117 | BUG_ON(err); |
| 1118 | } |
| 1119 | } |
| 1120 | #endif |
| 1121 | return ret; |
| 1122 | } |
| 1123 | |
| 1124 | static int write_one_cache_group(struct btrfs_trans_handle *trans, |
| 1125 | struct btrfs_root *root, |
| 1126 | struct btrfs_path *path, |
| 1127 | struct btrfs_block_group_cache *cache) |
| 1128 | { |
| 1129 | int ret; |
| 1130 | int pending_ret; |
| 1131 | struct btrfs_root *extent_root = root->fs_info->extent_root; |
| 1132 | unsigned long bi; |
| 1133 | struct extent_buffer *leaf; |
| 1134 | |
| 1135 | ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); |
| 1136 | if (ret < 0) |
| 1137 | goto fail; |
| 1138 | BUG_ON(ret); |
| 1139 | |
| 1140 | leaf = path->nodes[0]; |
| 1141 | bi = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| 1142 | write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); |
| 1143 | btrfs_mark_buffer_dirty(leaf); |
| 1144 | btrfs_release_path(extent_root, path); |
| 1145 | fail: |
| 1146 | finish_current_insert(trans, extent_root); |
| 1147 | pending_ret = del_pending_extents(trans, extent_root); |
| 1148 | if (ret) |
| 1149 | return ret; |
| 1150 | if (pending_ret) |
| 1151 | return pending_ret; |
| 1152 | return 0; |
| 1153 | |
| 1154 | } |
| 1155 | |
| 1156 | int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, |
| 1157 | struct btrfs_root *root) |
| 1158 | { |
| 1159 | struct extent_io_tree *block_group_cache; |
| 1160 | struct btrfs_block_group_cache *cache; |
| 1161 | int ret; |
| 1162 | int err = 0; |
| 1163 | int werr = 0; |
| 1164 | struct btrfs_path *path; |
| 1165 | u64 last = 0; |
| 1166 | u64 start; |
| 1167 | u64 end; |
| 1168 | u64 ptr; |
| 1169 | |
| 1170 | block_group_cache = &root->fs_info->block_group_cache; |
| 1171 | path = btrfs_alloc_path(); |
| 1172 | if (!path) |
| 1173 | return -ENOMEM; |
| 1174 | |
| 1175 | mutex_lock(&root->fs_info->alloc_mutex); |
| 1176 | while(1) { |
| 1177 | ret = find_first_extent_bit(block_group_cache, last, |
| 1178 | &start, &end, BLOCK_GROUP_DIRTY); |
| 1179 | if (ret) |
| 1180 | break; |
| 1181 | |
| 1182 | last = end + 1; |
| 1183 | ret = get_state_private(block_group_cache, start, &ptr); |
| 1184 | if (ret) |
| 1185 | break; |
| 1186 | cache = (struct btrfs_block_group_cache *)(unsigned long)ptr; |
| 1187 | err = write_one_cache_group(trans, root, |
| 1188 | path, cache); |
| 1189 | /* |
| 1190 | * if we fail to write the cache group, we want |
| 1191 | * to keep it marked dirty in hopes that a later |
| 1192 | * write will work |
| 1193 | */ |
| 1194 | if (err) { |
| 1195 | werr = err; |
| 1196 | continue; |
| 1197 | } |
| 1198 | clear_extent_bits(block_group_cache, start, end, |
| 1199 | BLOCK_GROUP_DIRTY, GFP_NOFS); |
| 1200 | } |
| 1201 | btrfs_free_path(path); |
| 1202 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 1203 | return werr; |
| 1204 | } |
| 1205 | |
| 1206 | static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, |
| 1207 | u64 flags) |
| 1208 | { |
| 1209 | struct list_head *head = &info->space_info; |
| 1210 | struct list_head *cur; |
| 1211 | struct btrfs_space_info *found; |
| 1212 | list_for_each(cur, head) { |
| 1213 | found = list_entry(cur, struct btrfs_space_info, list); |
| 1214 | if (found->flags == flags) |
| 1215 | return found; |
| 1216 | } |
| 1217 | return NULL; |
| 1218 | |
| 1219 | } |
| 1220 | |
| 1221 | static int update_space_info(struct btrfs_fs_info *info, u64 flags, |
| 1222 | u64 total_bytes, u64 bytes_used, |
| 1223 | struct btrfs_space_info **space_info) |
| 1224 | { |
| 1225 | struct btrfs_space_info *found; |
| 1226 | |
| 1227 | found = __find_space_info(info, flags); |
| 1228 | if (found) { |
| 1229 | found->total_bytes += total_bytes; |
| 1230 | found->bytes_used += bytes_used; |
| 1231 | found->full = 0; |
| 1232 | *space_info = found; |
| 1233 | return 0; |
| 1234 | } |
| 1235 | found = kmalloc(sizeof(*found), GFP_NOFS); |
| 1236 | if (!found) |
| 1237 | return -ENOMEM; |
| 1238 | |
| 1239 | list_add(&found->list, &info->space_info); |
| 1240 | found->flags = flags; |
| 1241 | found->total_bytes = total_bytes; |
| 1242 | found->bytes_used = bytes_used; |
| 1243 | found->bytes_pinned = 0; |
| 1244 | found->full = 0; |
| 1245 | found->force_alloc = 0; |
| 1246 | *space_info = found; |
| 1247 | return 0; |
| 1248 | } |
| 1249 | |
| 1250 | static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) |
| 1251 | { |
| 1252 | u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 | |
| 1253 | BTRFS_BLOCK_GROUP_RAID1 | |
| 1254 | BTRFS_BLOCK_GROUP_RAID10 | |
| 1255 | BTRFS_BLOCK_GROUP_DUP); |
| 1256 | if (extra_flags) { |
| 1257 | if (flags & BTRFS_BLOCK_GROUP_DATA) |
| 1258 | fs_info->avail_data_alloc_bits |= extra_flags; |
| 1259 | if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| 1260 | fs_info->avail_metadata_alloc_bits |= extra_flags; |
| 1261 | if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| 1262 | fs_info->avail_system_alloc_bits |= extra_flags; |
| 1263 | } |
| 1264 | } |
| 1265 | |
| 1266 | static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags) |
| 1267 | { |
| 1268 | u64 num_devices = root->fs_info->fs_devices->num_devices; |
| 1269 | |
| 1270 | if (num_devices == 1) |
| 1271 | flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0); |
| 1272 | if (num_devices < 4) |
| 1273 | flags &= ~BTRFS_BLOCK_GROUP_RAID10; |
| 1274 | |
| 1275 | if ((flags & BTRFS_BLOCK_GROUP_DUP) && |
| 1276 | (flags & (BTRFS_BLOCK_GROUP_RAID1 | |
| 1277 | BTRFS_BLOCK_GROUP_RAID10))) { |
| 1278 | flags &= ~BTRFS_BLOCK_GROUP_DUP; |
| 1279 | } |
| 1280 | |
| 1281 | if ((flags & BTRFS_BLOCK_GROUP_RAID1) && |
| 1282 | (flags & BTRFS_BLOCK_GROUP_RAID10)) { |
| 1283 | flags &= ~BTRFS_BLOCK_GROUP_RAID1; |
| 1284 | } |
| 1285 | |
| 1286 | if ((flags & BTRFS_BLOCK_GROUP_RAID0) && |
| 1287 | ((flags & BTRFS_BLOCK_GROUP_RAID1) | |
| 1288 | (flags & BTRFS_BLOCK_GROUP_RAID10) | |
| 1289 | (flags & BTRFS_BLOCK_GROUP_DUP))) |
| 1290 | flags &= ~BTRFS_BLOCK_GROUP_RAID0; |
| 1291 | return flags; |
| 1292 | } |
| 1293 | |
| 1294 | static int do_chunk_alloc(struct btrfs_trans_handle *trans, |
| 1295 | struct btrfs_root *extent_root, u64 alloc_bytes, |
| 1296 | u64 flags, int force) |
| 1297 | { |
| 1298 | struct btrfs_space_info *space_info; |
| 1299 | u64 thresh; |
| 1300 | u64 start; |
| 1301 | u64 num_bytes; |
| 1302 | int ret; |
| 1303 | |
| 1304 | flags = reduce_alloc_profile(extent_root, flags); |
| 1305 | |
| 1306 | space_info = __find_space_info(extent_root->fs_info, flags); |
| 1307 | if (!space_info) { |
| 1308 | ret = update_space_info(extent_root->fs_info, flags, |
| 1309 | 0, 0, &space_info); |
| 1310 | BUG_ON(ret); |
| 1311 | } |
| 1312 | BUG_ON(!space_info); |
| 1313 | |
| 1314 | if (space_info->force_alloc) { |
| 1315 | force = 1; |
| 1316 | space_info->force_alloc = 0; |
| 1317 | } |
| 1318 | if (space_info->full) |
| 1319 | goto out; |
| 1320 | |
| 1321 | thresh = div_factor(space_info->total_bytes, 6); |
| 1322 | if (!force && |
| 1323 | (space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) < |
| 1324 | thresh) |
| 1325 | goto out; |
| 1326 | |
| 1327 | mutex_lock(&extent_root->fs_info->chunk_mutex); |
| 1328 | ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags); |
| 1329 | if (ret == -ENOSPC) { |
| 1330 | printk("space info full %Lu\n", flags); |
| 1331 | space_info->full = 1; |
| 1332 | goto out_unlock; |
| 1333 | } |
| 1334 | BUG_ON(ret); |
| 1335 | |
| 1336 | ret = btrfs_make_block_group(trans, extent_root, 0, flags, |
| 1337 | BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes); |
| 1338 | BUG_ON(ret); |
| 1339 | out_unlock: |
| 1340 | mutex_unlock(&extent_root->fs_info->chunk_mutex); |
| 1341 | out: |
| 1342 | return 0; |
| 1343 | } |
| 1344 | |
| 1345 | static int update_block_group(struct btrfs_trans_handle *trans, |
| 1346 | struct btrfs_root *root, |
| 1347 | u64 bytenr, u64 num_bytes, int alloc, |
| 1348 | int mark_free) |
| 1349 | { |
| 1350 | struct btrfs_block_group_cache *cache; |
| 1351 | struct btrfs_fs_info *info = root->fs_info; |
| 1352 | u64 total = num_bytes; |
| 1353 | u64 old_val; |
| 1354 | u64 byte_in_group; |
| 1355 | u64 start; |
| 1356 | u64 end; |
| 1357 | |
| 1358 | WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); |
| 1359 | while(total) { |
| 1360 | cache = btrfs_lookup_block_group(info, bytenr); |
| 1361 | if (!cache) { |
| 1362 | return -1; |
| 1363 | } |
| 1364 | byte_in_group = bytenr - cache->key.objectid; |
| 1365 | WARN_ON(byte_in_group > cache->key.offset); |
| 1366 | start = cache->key.objectid; |
| 1367 | end = start + cache->key.offset - 1; |
| 1368 | set_extent_bits(&info->block_group_cache, start, end, |
| 1369 | BLOCK_GROUP_DIRTY, GFP_NOFS); |
| 1370 | |
| 1371 | spin_lock(&cache->lock); |
| 1372 | old_val = btrfs_block_group_used(&cache->item); |
| 1373 | num_bytes = min(total, cache->key.offset - byte_in_group); |
| 1374 | if (alloc) { |
| 1375 | old_val += num_bytes; |
| 1376 | cache->space_info->bytes_used += num_bytes; |
| 1377 | btrfs_set_block_group_used(&cache->item, old_val); |
| 1378 | spin_unlock(&cache->lock); |
| 1379 | } else { |
| 1380 | old_val -= num_bytes; |
| 1381 | cache->space_info->bytes_used -= num_bytes; |
| 1382 | btrfs_set_block_group_used(&cache->item, old_val); |
| 1383 | spin_unlock(&cache->lock); |
| 1384 | if (mark_free) { |
| 1385 | set_extent_dirty(&info->free_space_cache, |
| 1386 | bytenr, bytenr + num_bytes - 1, |
| 1387 | GFP_NOFS); |
| 1388 | } |
| 1389 | } |
| 1390 | total -= num_bytes; |
| 1391 | bytenr += num_bytes; |
| 1392 | } |
| 1393 | return 0; |
| 1394 | } |
| 1395 | |
| 1396 | static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) |
| 1397 | { |
| 1398 | u64 start; |
| 1399 | u64 end; |
| 1400 | int ret; |
| 1401 | ret = find_first_extent_bit(&root->fs_info->block_group_cache, |
| 1402 | search_start, &start, &end, |
| 1403 | BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA | |
| 1404 | BLOCK_GROUP_SYSTEM); |
| 1405 | if (ret) |
| 1406 | return 0; |
| 1407 | return start; |
| 1408 | } |
| 1409 | |
| 1410 | |
| 1411 | static int update_pinned_extents(struct btrfs_root *root, |
| 1412 | u64 bytenr, u64 num, int pin) |
| 1413 | { |
| 1414 | u64 len; |
| 1415 | struct btrfs_block_group_cache *cache; |
| 1416 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 1417 | |
| 1418 | WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); |
| 1419 | if (pin) { |
| 1420 | set_extent_dirty(&fs_info->pinned_extents, |
| 1421 | bytenr, bytenr + num - 1, GFP_NOFS); |
| 1422 | } else { |
| 1423 | clear_extent_dirty(&fs_info->pinned_extents, |
| 1424 | bytenr, bytenr + num - 1, GFP_NOFS); |
| 1425 | } |
| 1426 | while (num > 0) { |
| 1427 | cache = btrfs_lookup_block_group(fs_info, bytenr); |
| 1428 | if (!cache) { |
| 1429 | u64 first = first_logical_byte(root, bytenr); |
| 1430 | WARN_ON(first < bytenr); |
| 1431 | len = min(first - bytenr, num); |
| 1432 | } else { |
| 1433 | len = min(num, cache->key.offset - |
| 1434 | (bytenr - cache->key.objectid)); |
| 1435 | } |
| 1436 | if (pin) { |
| 1437 | if (cache) { |
| 1438 | spin_lock(&cache->lock); |
| 1439 | cache->pinned += len; |
| 1440 | cache->space_info->bytes_pinned += len; |
| 1441 | spin_unlock(&cache->lock); |
| 1442 | } |
| 1443 | fs_info->total_pinned += len; |
| 1444 | } else { |
| 1445 | if (cache) { |
| 1446 | spin_lock(&cache->lock); |
| 1447 | cache->pinned -= len; |
| 1448 | cache->space_info->bytes_pinned -= len; |
| 1449 | spin_unlock(&cache->lock); |
| 1450 | } |
| 1451 | fs_info->total_pinned -= len; |
| 1452 | } |
| 1453 | bytenr += len; |
| 1454 | num -= len; |
| 1455 | } |
| 1456 | return 0; |
| 1457 | } |
| 1458 | |
| 1459 | int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy) |
| 1460 | { |
| 1461 | u64 last = 0; |
| 1462 | u64 start; |
| 1463 | u64 end; |
| 1464 | struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents; |
| 1465 | int ret; |
| 1466 | |
| 1467 | while(1) { |
| 1468 | ret = find_first_extent_bit(pinned_extents, last, |
| 1469 | &start, &end, EXTENT_DIRTY); |
| 1470 | if (ret) |
| 1471 | break; |
| 1472 | set_extent_dirty(copy, start, end, GFP_NOFS); |
| 1473 | last = end + 1; |
| 1474 | } |
| 1475 | return 0; |
| 1476 | } |
| 1477 | |
| 1478 | int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, |
| 1479 | struct btrfs_root *root, |
| 1480 | struct extent_io_tree *unpin) |
| 1481 | { |
| 1482 | u64 start; |
| 1483 | u64 end; |
| 1484 | int ret; |
| 1485 | struct extent_io_tree *free_space_cache; |
| 1486 | free_space_cache = &root->fs_info->free_space_cache; |
| 1487 | |
| 1488 | mutex_lock(&root->fs_info->alloc_mutex); |
| 1489 | while(1) { |
| 1490 | ret = find_first_extent_bit(unpin, 0, &start, &end, |
| 1491 | EXTENT_DIRTY); |
| 1492 | if (ret) |
| 1493 | break; |
| 1494 | update_pinned_extents(root, start, end + 1 - start, 0); |
| 1495 | clear_extent_dirty(unpin, start, end, GFP_NOFS); |
| 1496 | set_extent_dirty(free_space_cache, start, end, GFP_NOFS); |
| 1497 | if (need_resched()) { |
| 1498 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 1499 | cond_resched(); |
| 1500 | mutex_lock(&root->fs_info->alloc_mutex); |
| 1501 | } |
| 1502 | } |
| 1503 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 1504 | return 0; |
| 1505 | } |
| 1506 | |
| 1507 | static int finish_current_insert(struct btrfs_trans_handle *trans, |
| 1508 | struct btrfs_root *extent_root) |
| 1509 | { |
| 1510 | u64 start; |
| 1511 | u64 end; |
| 1512 | struct btrfs_fs_info *info = extent_root->fs_info; |
| 1513 | struct extent_buffer *eb; |
| 1514 | struct btrfs_path *path; |
| 1515 | struct btrfs_key ins; |
| 1516 | struct btrfs_disk_key first; |
| 1517 | struct btrfs_extent_item extent_item; |
| 1518 | int ret; |
| 1519 | int level; |
| 1520 | int err = 0; |
| 1521 | |
| 1522 | WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); |
| 1523 | btrfs_set_stack_extent_refs(&extent_item, 1); |
| 1524 | btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY); |
| 1525 | path = btrfs_alloc_path(); |
| 1526 | |
| 1527 | while(1) { |
| 1528 | ret = find_first_extent_bit(&info->extent_ins, 0, &start, |
| 1529 | &end, EXTENT_LOCKED); |
| 1530 | if (ret) |
| 1531 | break; |
| 1532 | |
| 1533 | ins.objectid = start; |
| 1534 | ins.offset = end + 1 - start; |
| 1535 | err = btrfs_insert_item(trans, extent_root, &ins, |
| 1536 | &extent_item, sizeof(extent_item)); |
| 1537 | clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED, |
| 1538 | GFP_NOFS); |
| 1539 | |
| 1540 | eb = btrfs_find_tree_block(extent_root, ins.objectid, |
| 1541 | ins.offset); |
| 1542 | |
| 1543 | if (!btrfs_buffer_uptodate(eb, trans->transid)) { |
| 1544 | mutex_unlock(&extent_root->fs_info->alloc_mutex); |
| 1545 | btrfs_read_buffer(eb, trans->transid); |
| 1546 | mutex_lock(&extent_root->fs_info->alloc_mutex); |
| 1547 | } |
| 1548 | |
| 1549 | btrfs_tree_lock(eb); |
| 1550 | level = btrfs_header_level(eb); |
| 1551 | if (level == 0) { |
| 1552 | btrfs_item_key(eb, &first, 0); |
| 1553 | } else { |
| 1554 | btrfs_node_key(eb, &first, 0); |
| 1555 | } |
| 1556 | btrfs_tree_unlock(eb); |
| 1557 | free_extent_buffer(eb); |
| 1558 | /* |
| 1559 | * the first key is just a hint, so the race we've created |
| 1560 | * against reading it is fine |
| 1561 | */ |
| 1562 | err = btrfs_insert_extent_backref(trans, extent_root, path, |
| 1563 | start, extent_root->root_key.objectid, |
| 1564 | 0, level, |
| 1565 | btrfs_disk_key_objectid(&first)); |
| 1566 | BUG_ON(err); |
| 1567 | if (need_resched()) { |
| 1568 | mutex_unlock(&extent_root->fs_info->alloc_mutex); |
| 1569 | cond_resched(); |
| 1570 | mutex_lock(&extent_root->fs_info->alloc_mutex); |
| 1571 | } |
| 1572 | } |
| 1573 | btrfs_free_path(path); |
| 1574 | return 0; |
| 1575 | } |
| 1576 | |
| 1577 | static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes, |
| 1578 | int pending) |
| 1579 | { |
| 1580 | int err = 0; |
| 1581 | |
| 1582 | WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); |
| 1583 | if (!pending) { |
| 1584 | struct extent_buffer *buf; |
| 1585 | buf = btrfs_find_tree_block(root, bytenr, num_bytes); |
| 1586 | if (buf) { |
| 1587 | if (btrfs_buffer_uptodate(buf, 0) && |
| 1588 | btrfs_try_tree_lock(buf)) { |
| 1589 | u64 transid = |
| 1590 | root->fs_info->running_transaction->transid; |
| 1591 | u64 header_transid = |
| 1592 | btrfs_header_generation(buf); |
| 1593 | if (header_transid == transid && |
| 1594 | !btrfs_header_flag(buf, |
| 1595 | BTRFS_HEADER_FLAG_WRITTEN)) { |
| 1596 | clean_tree_block(NULL, root, buf); |
| 1597 | btrfs_tree_unlock(buf); |
| 1598 | free_extent_buffer(buf); |
| 1599 | return 1; |
| 1600 | } |
| 1601 | btrfs_tree_unlock(buf); |
| 1602 | } |
| 1603 | free_extent_buffer(buf); |
| 1604 | } |
| 1605 | update_pinned_extents(root, bytenr, num_bytes, 1); |
| 1606 | } else { |
| 1607 | set_extent_bits(&root->fs_info->pending_del, |
| 1608 | bytenr, bytenr + num_bytes - 1, |
| 1609 | EXTENT_LOCKED, GFP_NOFS); |
| 1610 | } |
| 1611 | BUG_ON(err < 0); |
| 1612 | return 0; |
| 1613 | } |
| 1614 | |
| 1615 | /* |
| 1616 | * remove an extent from the root, returns 0 on success |
| 1617 | */ |
| 1618 | static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
| 1619 | *root, u64 bytenr, u64 num_bytes, |
| 1620 | u64 root_objectid, u64 ref_generation, |
| 1621 | u64 owner_objectid, u64 owner_offset, int pin, |
| 1622 | int mark_free) |
| 1623 | { |
| 1624 | struct btrfs_path *path; |
| 1625 | struct btrfs_key key; |
| 1626 | struct btrfs_fs_info *info = root->fs_info; |
| 1627 | struct btrfs_root *extent_root = info->extent_root; |
| 1628 | struct extent_buffer *leaf; |
| 1629 | int ret; |
| 1630 | int extent_slot = 0; |
| 1631 | int found_extent = 0; |
| 1632 | int num_to_del = 1; |
| 1633 | struct btrfs_extent_item *ei; |
| 1634 | u32 refs; |
| 1635 | |
| 1636 | WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); |
| 1637 | key.objectid = bytenr; |
| 1638 | btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| 1639 | key.offset = num_bytes; |
| 1640 | path = btrfs_alloc_path(); |
| 1641 | if (!path) |
| 1642 | return -ENOMEM; |
| 1643 | |
| 1644 | path->reada = 1; |
| 1645 | ret = lookup_extent_backref(trans, extent_root, path, |
| 1646 | bytenr, root_objectid, |
| 1647 | ref_generation, |
| 1648 | owner_objectid, owner_offset, 1); |
| 1649 | if (ret == 0) { |
| 1650 | struct btrfs_key found_key; |
| 1651 | extent_slot = path->slots[0]; |
| 1652 | while(extent_slot > 0) { |
| 1653 | extent_slot--; |
| 1654 | btrfs_item_key_to_cpu(path->nodes[0], &found_key, |
| 1655 | extent_slot); |
| 1656 | if (found_key.objectid != bytenr) |
| 1657 | break; |
| 1658 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
| 1659 | found_key.offset == num_bytes) { |
| 1660 | found_extent = 1; |
| 1661 | break; |
| 1662 | } |
| 1663 | if (path->slots[0] - extent_slot > 5) |
| 1664 | break; |
| 1665 | } |
| 1666 | if (!found_extent) |
| 1667 | ret = btrfs_del_item(trans, extent_root, path); |
| 1668 | } else { |
| 1669 | btrfs_print_leaf(extent_root, path->nodes[0]); |
| 1670 | WARN_ON(1); |
| 1671 | printk("Unable to find ref byte nr %Lu root %Lu " |
| 1672 | " gen %Lu owner %Lu offset %Lu\n", bytenr, |
| 1673 | root_objectid, ref_generation, owner_objectid, |
| 1674 | owner_offset); |
| 1675 | } |
| 1676 | if (!found_extent) { |
| 1677 | btrfs_release_path(extent_root, path); |
| 1678 | ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); |
| 1679 | if (ret < 0) |
| 1680 | return ret; |
| 1681 | BUG_ON(ret); |
| 1682 | extent_slot = path->slots[0]; |
| 1683 | } |
| 1684 | |
| 1685 | leaf = path->nodes[0]; |
| 1686 | ei = btrfs_item_ptr(leaf, extent_slot, |
| 1687 | struct btrfs_extent_item); |
| 1688 | refs = btrfs_extent_refs(leaf, ei); |
| 1689 | BUG_ON(refs == 0); |
| 1690 | refs -= 1; |
| 1691 | btrfs_set_extent_refs(leaf, ei, refs); |
| 1692 | |
| 1693 | btrfs_mark_buffer_dirty(leaf); |
| 1694 | |
| 1695 | if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) { |
| 1696 | /* if the back ref and the extent are next to each other |
| 1697 | * they get deleted below in one shot |
| 1698 | */ |
| 1699 | path->slots[0] = extent_slot; |
| 1700 | num_to_del = 2; |
| 1701 | } else if (found_extent) { |
| 1702 | /* otherwise delete the extent back ref */ |
| 1703 | ret = btrfs_del_item(trans, extent_root, path); |
| 1704 | BUG_ON(ret); |
| 1705 | /* if refs are 0, we need to setup the path for deletion */ |
| 1706 | if (refs == 0) { |
| 1707 | btrfs_release_path(extent_root, path); |
| 1708 | ret = btrfs_search_slot(trans, extent_root, &key, path, |
| 1709 | -1, 1); |
| 1710 | if (ret < 0) |
| 1711 | return ret; |
| 1712 | BUG_ON(ret); |
| 1713 | } |
| 1714 | } |
| 1715 | |
| 1716 | if (refs == 0) { |
| 1717 | u64 super_used; |
| 1718 | u64 root_used; |
| 1719 | |
| 1720 | if (pin) { |
| 1721 | ret = pin_down_bytes(root, bytenr, num_bytes, 0); |
| 1722 | if (ret > 0) |
| 1723 | mark_free = 1; |
| 1724 | BUG_ON(ret < 0); |
| 1725 | } |
| 1726 | |
| 1727 | /* block accounting for super block */ |
| 1728 | spin_lock_irq(&info->delalloc_lock); |
| 1729 | super_used = btrfs_super_bytes_used(&info->super_copy); |
| 1730 | btrfs_set_super_bytes_used(&info->super_copy, |
| 1731 | super_used - num_bytes); |
| 1732 | spin_unlock_irq(&info->delalloc_lock); |
| 1733 | |
| 1734 | /* block accounting for root item */ |
| 1735 | root_used = btrfs_root_used(&root->root_item); |
| 1736 | btrfs_set_root_used(&root->root_item, |
| 1737 | root_used - num_bytes); |
| 1738 | ret = btrfs_del_items(trans, extent_root, path, path->slots[0], |
| 1739 | num_to_del); |
| 1740 | if (ret) { |
| 1741 | return ret; |
| 1742 | } |
| 1743 | ret = update_block_group(trans, root, bytenr, num_bytes, 0, |
| 1744 | mark_free); |
| 1745 | BUG_ON(ret); |
| 1746 | } |
| 1747 | btrfs_free_path(path); |
| 1748 | finish_current_insert(trans, extent_root); |
| 1749 | return ret; |
| 1750 | } |
| 1751 | |
| 1752 | /* |
| 1753 | * find all the blocks marked as pending in the radix tree and remove |
| 1754 | * them from the extent map |
| 1755 | */ |
| 1756 | static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
| 1757 | btrfs_root *extent_root) |
| 1758 | { |
| 1759 | int ret; |
| 1760 | int err = 0; |
| 1761 | u64 start; |
| 1762 | u64 end; |
| 1763 | struct extent_io_tree *pending_del; |
| 1764 | struct extent_io_tree *pinned_extents; |
| 1765 | |
| 1766 | WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); |
| 1767 | pending_del = &extent_root->fs_info->pending_del; |
| 1768 | pinned_extents = &extent_root->fs_info->pinned_extents; |
| 1769 | |
| 1770 | while(1) { |
| 1771 | ret = find_first_extent_bit(pending_del, 0, &start, &end, |
| 1772 | EXTENT_LOCKED); |
| 1773 | if (ret) |
| 1774 | break; |
| 1775 | clear_extent_bits(pending_del, start, end, EXTENT_LOCKED, |
| 1776 | GFP_NOFS); |
| 1777 | if (!test_range_bit(&extent_root->fs_info->extent_ins, |
| 1778 | start, end, EXTENT_LOCKED, 0)) { |
| 1779 | update_pinned_extents(extent_root, start, |
| 1780 | end + 1 - start, 1); |
| 1781 | ret = __free_extent(trans, extent_root, |
| 1782 | start, end + 1 - start, |
| 1783 | extent_root->root_key.objectid, |
| 1784 | 0, 0, 0, 0, 0); |
| 1785 | } else { |
| 1786 | clear_extent_bits(&extent_root->fs_info->extent_ins, |
| 1787 | start, end, EXTENT_LOCKED, GFP_NOFS); |
| 1788 | } |
| 1789 | if (ret) |
| 1790 | err = ret; |
| 1791 | |
| 1792 | if (need_resched()) { |
| 1793 | mutex_unlock(&extent_root->fs_info->alloc_mutex); |
| 1794 | cond_resched(); |
| 1795 | mutex_lock(&extent_root->fs_info->alloc_mutex); |
| 1796 | } |
| 1797 | } |
| 1798 | return err; |
| 1799 | } |
| 1800 | |
| 1801 | /* |
| 1802 | * remove an extent from the root, returns 0 on success |
| 1803 | */ |
| 1804 | static int __btrfs_free_extent(struct btrfs_trans_handle *trans, |
| 1805 | struct btrfs_root *root, u64 bytenr, |
| 1806 | u64 num_bytes, u64 root_objectid, |
| 1807 | u64 ref_generation, u64 owner_objectid, |
| 1808 | u64 owner_offset, int pin) |
| 1809 | { |
| 1810 | struct btrfs_root *extent_root = root->fs_info->extent_root; |
| 1811 | int pending_ret; |
| 1812 | int ret; |
| 1813 | |
| 1814 | WARN_ON(num_bytes < root->sectorsize); |
| 1815 | if (!root->ref_cows) |
| 1816 | ref_generation = 0; |
| 1817 | |
| 1818 | if (root == extent_root) { |
| 1819 | pin_down_bytes(root, bytenr, num_bytes, 1); |
| 1820 | return 0; |
| 1821 | } |
| 1822 | ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid, |
| 1823 | ref_generation, owner_objectid, owner_offset, |
| 1824 | pin, pin == 0); |
| 1825 | |
| 1826 | finish_current_insert(trans, root->fs_info->extent_root); |
| 1827 | pending_ret = del_pending_extents(trans, root->fs_info->extent_root); |
| 1828 | return ret ? ret : pending_ret; |
| 1829 | } |
| 1830 | |
| 1831 | int btrfs_free_extent(struct btrfs_trans_handle *trans, |
| 1832 | struct btrfs_root *root, u64 bytenr, |
| 1833 | u64 num_bytes, u64 root_objectid, |
| 1834 | u64 ref_generation, u64 owner_objectid, |
| 1835 | u64 owner_offset, int pin) |
| 1836 | { |
| 1837 | int ret; |
| 1838 | |
| 1839 | maybe_lock_mutex(root); |
| 1840 | ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, |
| 1841 | root_objectid, ref_generation, |
| 1842 | owner_objectid, owner_offset, pin); |
| 1843 | maybe_unlock_mutex(root); |
| 1844 | return ret; |
| 1845 | } |
| 1846 | |
| 1847 | static u64 stripe_align(struct btrfs_root *root, u64 val) |
| 1848 | { |
| 1849 | u64 mask = ((u64)root->stripesize - 1); |
| 1850 | u64 ret = (val + mask) & ~mask; |
| 1851 | return ret; |
| 1852 | } |
| 1853 | |
| 1854 | /* |
| 1855 | * walks the btree of allocated extents and find a hole of a given size. |
| 1856 | * The key ins is changed to record the hole: |
| 1857 | * ins->objectid == block start |
| 1858 | * ins->flags = BTRFS_EXTENT_ITEM_KEY |
| 1859 | * ins->offset == number of blocks |
| 1860 | * Any available blocks before search_start are skipped. |
| 1861 | */ |
| 1862 | static int noinline find_free_extent(struct btrfs_trans_handle *trans, |
| 1863 | struct btrfs_root *orig_root, |
| 1864 | u64 num_bytes, u64 empty_size, |
| 1865 | u64 search_start, u64 search_end, |
| 1866 | u64 hint_byte, struct btrfs_key *ins, |
| 1867 | u64 exclude_start, u64 exclude_nr, |
| 1868 | int data) |
| 1869 | { |
| 1870 | int ret; |
| 1871 | u64 orig_search_start; |
| 1872 | struct btrfs_root * root = orig_root->fs_info->extent_root; |
| 1873 | struct btrfs_fs_info *info = root->fs_info; |
| 1874 | u64 total_needed = num_bytes; |
| 1875 | u64 *last_ptr = NULL; |
| 1876 | struct btrfs_block_group_cache *block_group; |
| 1877 | int full_scan = 0; |
| 1878 | int wrapped = 0; |
| 1879 | int chunk_alloc_done = 0; |
| 1880 | int empty_cluster = 2 * 1024 * 1024; |
| 1881 | int allowed_chunk_alloc = 0; |
| 1882 | |
| 1883 | WARN_ON(num_bytes < root->sectorsize); |
| 1884 | btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); |
| 1885 | |
| 1886 | if (orig_root->ref_cows || empty_size) |
| 1887 | allowed_chunk_alloc = 1; |
| 1888 | |
| 1889 | if (data & BTRFS_BLOCK_GROUP_METADATA) { |
| 1890 | last_ptr = &root->fs_info->last_alloc; |
| 1891 | empty_cluster = 256 * 1024; |
| 1892 | } |
| 1893 | |
| 1894 | if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) { |
| 1895 | last_ptr = &root->fs_info->last_data_alloc; |
| 1896 | } |
| 1897 | |
| 1898 | if (last_ptr) { |
| 1899 | if (*last_ptr) |
| 1900 | hint_byte = *last_ptr; |
| 1901 | else { |
| 1902 | empty_size += empty_cluster; |
| 1903 | } |
| 1904 | } |
| 1905 | |
| 1906 | search_start = max(search_start, first_logical_byte(root, 0)); |
| 1907 | orig_search_start = search_start; |
| 1908 | |
| 1909 | if (search_end == (u64)-1) |
| 1910 | search_end = btrfs_super_total_bytes(&info->super_copy); |
| 1911 | |
| 1912 | if (hint_byte) { |
| 1913 | block_group = btrfs_lookup_first_block_group(info, hint_byte); |
| 1914 | if (!block_group) |
| 1915 | hint_byte = search_start; |
| 1916 | block_group = btrfs_find_block_group(root, block_group, |
| 1917 | hint_byte, data, 1); |
| 1918 | if (last_ptr && *last_ptr == 0 && block_group) |
| 1919 | hint_byte = block_group->key.objectid; |
| 1920 | } else { |
| 1921 | block_group = btrfs_find_block_group(root, |
| 1922 | trans->block_group, |
| 1923 | search_start, data, 1); |
| 1924 | } |
| 1925 | search_start = max(search_start, hint_byte); |
| 1926 | |
| 1927 | total_needed += empty_size; |
| 1928 | |
| 1929 | check_failed: |
| 1930 | if (!block_group) { |
| 1931 | block_group = btrfs_lookup_first_block_group(info, |
| 1932 | search_start); |
| 1933 | if (!block_group) |
| 1934 | block_group = btrfs_lookup_first_block_group(info, |
| 1935 | orig_search_start); |
| 1936 | } |
| 1937 | if (full_scan && !chunk_alloc_done) { |
| 1938 | if (allowed_chunk_alloc) { |
| 1939 | do_chunk_alloc(trans, root, |
| 1940 | num_bytes + 2 * 1024 * 1024, data, 1); |
| 1941 | allowed_chunk_alloc = 0; |
| 1942 | } else if (block_group && block_group_bits(block_group, data)) { |
| 1943 | block_group->space_info->force_alloc = 1; |
| 1944 | } |
| 1945 | chunk_alloc_done = 1; |
| 1946 | } |
| 1947 | ret = find_search_start(root, &block_group, &search_start, |
| 1948 | total_needed, data); |
| 1949 | if (ret == -ENOSPC && last_ptr && *last_ptr) { |
| 1950 | *last_ptr = 0; |
| 1951 | block_group = btrfs_lookup_first_block_group(info, |
| 1952 | orig_search_start); |
| 1953 | search_start = orig_search_start; |
| 1954 | ret = find_search_start(root, &block_group, &search_start, |
| 1955 | total_needed, data); |
| 1956 | } |
| 1957 | if (ret == -ENOSPC) |
| 1958 | goto enospc; |
| 1959 | if (ret) |
| 1960 | goto error; |
| 1961 | |
| 1962 | if (last_ptr && *last_ptr && search_start != *last_ptr) { |
| 1963 | *last_ptr = 0; |
| 1964 | if (!empty_size) { |
| 1965 | empty_size += empty_cluster; |
| 1966 | total_needed += empty_size; |
| 1967 | } |
| 1968 | block_group = btrfs_lookup_first_block_group(info, |
| 1969 | orig_search_start); |
| 1970 | search_start = orig_search_start; |
| 1971 | ret = find_search_start(root, &block_group, |
| 1972 | &search_start, total_needed, data); |
| 1973 | if (ret == -ENOSPC) |
| 1974 | goto enospc; |
| 1975 | if (ret) |
| 1976 | goto error; |
| 1977 | } |
| 1978 | |
| 1979 | search_start = stripe_align(root, search_start); |
| 1980 | ins->objectid = search_start; |
| 1981 | ins->offset = num_bytes; |
| 1982 | |
| 1983 | if (ins->objectid + num_bytes >= search_end) |
| 1984 | goto enospc; |
| 1985 | |
| 1986 | if (ins->objectid + num_bytes > |
| 1987 | block_group->key.objectid + block_group->key.offset) { |
| 1988 | search_start = block_group->key.objectid + |
| 1989 | block_group->key.offset; |
| 1990 | goto new_group; |
| 1991 | } |
| 1992 | |
| 1993 | if (test_range_bit(&info->extent_ins, ins->objectid, |
| 1994 | ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) { |
| 1995 | search_start = ins->objectid + num_bytes; |
| 1996 | goto new_group; |
| 1997 | } |
| 1998 | |
| 1999 | if (test_range_bit(&info->pinned_extents, ins->objectid, |
| 2000 | ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) { |
| 2001 | search_start = ins->objectid + num_bytes; |
| 2002 | goto new_group; |
| 2003 | } |
| 2004 | |
| 2005 | if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start && |
| 2006 | ins->objectid < exclude_start + exclude_nr)) { |
| 2007 | search_start = exclude_start + exclude_nr; |
| 2008 | goto new_group; |
| 2009 | } |
| 2010 | |
| 2011 | if (!(data & BTRFS_BLOCK_GROUP_DATA)) { |
| 2012 | block_group = btrfs_lookup_block_group(info, ins->objectid); |
| 2013 | if (block_group) |
| 2014 | trans->block_group = block_group; |
| 2015 | } |
| 2016 | ins->offset = num_bytes; |
| 2017 | if (last_ptr) { |
| 2018 | *last_ptr = ins->objectid + ins->offset; |
| 2019 | if (*last_ptr == |
| 2020 | btrfs_super_total_bytes(&root->fs_info->super_copy)) { |
| 2021 | *last_ptr = 0; |
| 2022 | } |
| 2023 | } |
| 2024 | return 0; |
| 2025 | |
| 2026 | new_group: |
| 2027 | if (search_start + num_bytes >= search_end) { |
| 2028 | enospc: |
| 2029 | search_start = orig_search_start; |
| 2030 | if (full_scan) { |
| 2031 | ret = -ENOSPC; |
| 2032 | goto error; |
| 2033 | } |
| 2034 | if (wrapped) { |
| 2035 | if (!full_scan) |
| 2036 | total_needed -= empty_size; |
| 2037 | full_scan = 1; |
| 2038 | } else |
| 2039 | wrapped = 1; |
| 2040 | } |
| 2041 | block_group = btrfs_lookup_first_block_group(info, search_start); |
| 2042 | cond_resched(); |
| 2043 | block_group = btrfs_find_block_group(root, block_group, |
| 2044 | search_start, data, 0); |
| 2045 | goto check_failed; |
| 2046 | |
| 2047 | error: |
| 2048 | return ret; |
| 2049 | } |
| 2050 | |
| 2051 | static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans, |
| 2052 | struct btrfs_root *root, |
| 2053 | u64 num_bytes, u64 min_alloc_size, |
| 2054 | u64 empty_size, u64 hint_byte, |
| 2055 | u64 search_end, struct btrfs_key *ins, |
| 2056 | u64 data) |
| 2057 | { |
| 2058 | int ret; |
| 2059 | u64 search_start = 0; |
| 2060 | u64 alloc_profile; |
| 2061 | struct btrfs_fs_info *info = root->fs_info; |
| 2062 | |
| 2063 | if (data) { |
| 2064 | alloc_profile = info->avail_data_alloc_bits & |
| 2065 | info->data_alloc_profile; |
| 2066 | data = BTRFS_BLOCK_GROUP_DATA | alloc_profile; |
| 2067 | } else if (root == root->fs_info->chunk_root) { |
| 2068 | alloc_profile = info->avail_system_alloc_bits & |
| 2069 | info->system_alloc_profile; |
| 2070 | data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile; |
| 2071 | } else { |
| 2072 | alloc_profile = info->avail_metadata_alloc_bits & |
| 2073 | info->metadata_alloc_profile; |
| 2074 | data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile; |
| 2075 | } |
| 2076 | again: |
| 2077 | data = reduce_alloc_profile(root, data); |
| 2078 | /* |
| 2079 | * the only place that sets empty_size is btrfs_realloc_node, which |
| 2080 | * is not called recursively on allocations |
| 2081 | */ |
| 2082 | if (empty_size || root->ref_cows) { |
| 2083 | if (!(data & BTRFS_BLOCK_GROUP_METADATA)) { |
| 2084 | ret = do_chunk_alloc(trans, root->fs_info->extent_root, |
| 2085 | 2 * 1024 * 1024, |
| 2086 | BTRFS_BLOCK_GROUP_METADATA | |
| 2087 | (info->metadata_alloc_profile & |
| 2088 | info->avail_metadata_alloc_bits), 0); |
| 2089 | BUG_ON(ret); |
| 2090 | } |
| 2091 | ret = do_chunk_alloc(trans, root->fs_info->extent_root, |
| 2092 | num_bytes + 2 * 1024 * 1024, data, 0); |
| 2093 | BUG_ON(ret); |
| 2094 | } |
| 2095 | |
| 2096 | WARN_ON(num_bytes < root->sectorsize); |
| 2097 | ret = find_free_extent(trans, root, num_bytes, empty_size, |
| 2098 | search_start, search_end, hint_byte, ins, |
| 2099 | trans->alloc_exclude_start, |
| 2100 | trans->alloc_exclude_nr, data); |
| 2101 | |
| 2102 | if (ret == -ENOSPC && num_bytes > min_alloc_size) { |
| 2103 | num_bytes = num_bytes >> 1; |
| 2104 | num_bytes = max(num_bytes, min_alloc_size); |
| 2105 | do_chunk_alloc(trans, root->fs_info->extent_root, |
| 2106 | num_bytes, data, 1); |
| 2107 | goto again; |
| 2108 | } |
| 2109 | if (ret) { |
| 2110 | printk("allocation failed flags %Lu\n", data); |
| 2111 | BUG(); |
| 2112 | } |
| 2113 | clear_extent_dirty(&root->fs_info->free_space_cache, |
| 2114 | ins->objectid, ins->objectid + ins->offset - 1, |
| 2115 | GFP_NOFS); |
| 2116 | return 0; |
| 2117 | } |
| 2118 | |
| 2119 | int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len) |
| 2120 | { |
| 2121 | maybe_lock_mutex(root); |
| 2122 | set_extent_dirty(&root->fs_info->free_space_cache, |
| 2123 | start, start + len - 1, GFP_NOFS); |
| 2124 | maybe_unlock_mutex(root); |
| 2125 | return 0; |
| 2126 | } |
| 2127 | |
| 2128 | int btrfs_reserve_extent(struct btrfs_trans_handle *trans, |
| 2129 | struct btrfs_root *root, |
| 2130 | u64 num_bytes, u64 min_alloc_size, |
| 2131 | u64 empty_size, u64 hint_byte, |
| 2132 | u64 search_end, struct btrfs_key *ins, |
| 2133 | u64 data) |
| 2134 | { |
| 2135 | int ret; |
| 2136 | maybe_lock_mutex(root); |
| 2137 | ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, |
| 2138 | empty_size, hint_byte, search_end, ins, |
| 2139 | data); |
| 2140 | maybe_unlock_mutex(root); |
| 2141 | return ret; |
| 2142 | } |
| 2143 | |
| 2144 | static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, |
| 2145 | struct btrfs_root *root, |
| 2146 | u64 root_objectid, u64 ref_generation, |
| 2147 | u64 owner, u64 owner_offset, |
| 2148 | struct btrfs_key *ins) |
| 2149 | { |
| 2150 | int ret; |
| 2151 | int pending_ret; |
| 2152 | u64 super_used; |
| 2153 | u64 root_used; |
| 2154 | u64 num_bytes = ins->offset; |
| 2155 | u32 sizes[2]; |
| 2156 | struct btrfs_fs_info *info = root->fs_info; |
| 2157 | struct btrfs_root *extent_root = info->extent_root; |
| 2158 | struct btrfs_extent_item *extent_item; |
| 2159 | struct btrfs_extent_ref *ref; |
| 2160 | struct btrfs_path *path; |
| 2161 | struct btrfs_key keys[2]; |
| 2162 | |
| 2163 | /* block accounting for super block */ |
| 2164 | spin_lock_irq(&info->delalloc_lock); |
| 2165 | super_used = btrfs_super_bytes_used(&info->super_copy); |
| 2166 | btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes); |
| 2167 | spin_unlock_irq(&info->delalloc_lock); |
| 2168 | |
| 2169 | /* block accounting for root item */ |
| 2170 | root_used = btrfs_root_used(&root->root_item); |
| 2171 | btrfs_set_root_used(&root->root_item, root_used + num_bytes); |
| 2172 | |
| 2173 | if (root == extent_root) { |
| 2174 | set_extent_bits(&root->fs_info->extent_ins, ins->objectid, |
| 2175 | ins->objectid + ins->offset - 1, |
| 2176 | EXTENT_LOCKED, GFP_NOFS); |
| 2177 | goto update_block; |
| 2178 | } |
| 2179 | |
| 2180 | memcpy(&keys[0], ins, sizeof(*ins)); |
| 2181 | keys[1].offset = hash_extent_ref(root_objectid, ref_generation, |
| 2182 | owner, owner_offset); |
| 2183 | keys[1].objectid = ins->objectid; |
| 2184 | keys[1].type = BTRFS_EXTENT_REF_KEY; |
| 2185 | sizes[0] = sizeof(*extent_item); |
| 2186 | sizes[1] = sizeof(*ref); |
| 2187 | |
| 2188 | path = btrfs_alloc_path(); |
| 2189 | BUG_ON(!path); |
| 2190 | |
| 2191 | ret = btrfs_insert_empty_items(trans, extent_root, path, keys, |
| 2192 | sizes, 2); |
| 2193 | |
| 2194 | BUG_ON(ret); |
| 2195 | extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| 2196 | struct btrfs_extent_item); |
| 2197 | btrfs_set_extent_refs(path->nodes[0], extent_item, 1); |
| 2198 | ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, |
| 2199 | struct btrfs_extent_ref); |
| 2200 | |
| 2201 | btrfs_set_ref_root(path->nodes[0], ref, root_objectid); |
| 2202 | btrfs_set_ref_generation(path->nodes[0], ref, ref_generation); |
| 2203 | btrfs_set_ref_objectid(path->nodes[0], ref, owner); |
| 2204 | btrfs_set_ref_offset(path->nodes[0], ref, owner_offset); |
| 2205 | |
| 2206 | btrfs_mark_buffer_dirty(path->nodes[0]); |
| 2207 | |
| 2208 | trans->alloc_exclude_start = 0; |
| 2209 | trans->alloc_exclude_nr = 0; |
| 2210 | btrfs_free_path(path); |
| 2211 | finish_current_insert(trans, extent_root); |
| 2212 | pending_ret = del_pending_extents(trans, extent_root); |
| 2213 | |
| 2214 | if (ret) |
| 2215 | goto out; |
| 2216 | if (pending_ret) { |
| 2217 | ret = pending_ret; |
| 2218 | goto out; |
| 2219 | } |
| 2220 | |
| 2221 | update_block: |
| 2222 | ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0); |
| 2223 | if (ret) { |
| 2224 | printk("update block group failed for %Lu %Lu\n", |
| 2225 | ins->objectid, ins->offset); |
| 2226 | BUG(); |
| 2227 | } |
| 2228 | out: |
| 2229 | return ret; |
| 2230 | } |
| 2231 | |
| 2232 | int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, |
| 2233 | struct btrfs_root *root, |
| 2234 | u64 root_objectid, u64 ref_generation, |
| 2235 | u64 owner, u64 owner_offset, |
| 2236 | struct btrfs_key *ins) |
| 2237 | { |
| 2238 | int ret; |
| 2239 | maybe_lock_mutex(root); |
| 2240 | ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid, |
| 2241 | ref_generation, owner, |
| 2242 | owner_offset, ins); |
| 2243 | maybe_unlock_mutex(root); |
| 2244 | return ret; |
| 2245 | } |
| 2246 | /* |
| 2247 | * finds a free extent and does all the dirty work required for allocation |
| 2248 | * returns the key for the extent through ins, and a tree buffer for |
| 2249 | * the first block of the extent through buf. |
| 2250 | * |
| 2251 | * returns 0 if everything worked, non-zero otherwise. |
| 2252 | */ |
| 2253 | int btrfs_alloc_extent(struct btrfs_trans_handle *trans, |
| 2254 | struct btrfs_root *root, |
| 2255 | u64 num_bytes, u64 min_alloc_size, |
| 2256 | u64 root_objectid, u64 ref_generation, |
| 2257 | u64 owner, u64 owner_offset, |
| 2258 | u64 empty_size, u64 hint_byte, |
| 2259 | u64 search_end, struct btrfs_key *ins, u64 data) |
| 2260 | { |
| 2261 | int ret; |
| 2262 | |
| 2263 | maybe_lock_mutex(root); |
| 2264 | |
| 2265 | ret = __btrfs_reserve_extent(trans, root, num_bytes, |
| 2266 | min_alloc_size, empty_size, hint_byte, |
| 2267 | search_end, ins, data); |
| 2268 | BUG_ON(ret); |
| 2269 | ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid, |
| 2270 | ref_generation, owner, |
| 2271 | owner_offset, ins); |
| 2272 | BUG_ON(ret); |
| 2273 | |
| 2274 | maybe_unlock_mutex(root); |
| 2275 | return ret; |
| 2276 | } |
| 2277 | |
| 2278 | struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, |
| 2279 | struct btrfs_root *root, |
| 2280 | u64 bytenr, u32 blocksize) |
| 2281 | { |
| 2282 | struct extent_buffer *buf; |
| 2283 | |
| 2284 | buf = btrfs_find_create_tree_block(root, bytenr, blocksize); |
| 2285 | if (!buf) |
| 2286 | return ERR_PTR(-ENOMEM); |
| 2287 | btrfs_set_header_generation(buf, trans->transid); |
| 2288 | btrfs_tree_lock(buf); |
| 2289 | clean_tree_block(trans, root, buf); |
| 2290 | btrfs_set_buffer_uptodate(buf); |
| 2291 | set_extent_dirty(&trans->transaction->dirty_pages, buf->start, |
| 2292 | buf->start + buf->len - 1, GFP_NOFS); |
| 2293 | trans->blocks_used++; |
| 2294 | return buf; |
| 2295 | } |
| 2296 | |
| 2297 | /* |
| 2298 | * helper function to allocate a block for a given tree |
| 2299 | * returns the tree buffer or NULL. |
| 2300 | */ |
| 2301 | struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, |
| 2302 | struct btrfs_root *root, |
| 2303 | u32 blocksize, |
| 2304 | u64 root_objectid, |
| 2305 | u64 ref_generation, |
| 2306 | u64 first_objectid, |
| 2307 | int level, |
| 2308 | u64 hint, |
| 2309 | u64 empty_size) |
| 2310 | { |
| 2311 | struct btrfs_key ins; |
| 2312 | int ret; |
| 2313 | struct extent_buffer *buf; |
| 2314 | |
| 2315 | ret = btrfs_alloc_extent(trans, root, blocksize, blocksize, |
| 2316 | root_objectid, ref_generation, |
| 2317 | level, first_objectid, empty_size, hint, |
| 2318 | (u64)-1, &ins, 0); |
| 2319 | if (ret) { |
| 2320 | BUG_ON(ret > 0); |
| 2321 | return ERR_PTR(ret); |
| 2322 | } |
| 2323 | |
| 2324 | buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize); |
| 2325 | return buf; |
| 2326 | } |
| 2327 | |
| 2328 | static int noinline drop_leaf_ref_no_cache(struct btrfs_trans_handle *trans, |
| 2329 | struct btrfs_root *root, |
| 2330 | struct extent_buffer *leaf) |
| 2331 | { |
| 2332 | u64 leaf_owner; |
| 2333 | u64 leaf_generation; |
| 2334 | struct btrfs_key key; |
| 2335 | struct btrfs_file_extent_item *fi; |
| 2336 | int i; |
| 2337 | int nritems; |
| 2338 | int ret; |
| 2339 | |
| 2340 | BUG_ON(!btrfs_is_leaf(leaf)); |
| 2341 | nritems = btrfs_header_nritems(leaf); |
| 2342 | leaf_owner = btrfs_header_owner(leaf); |
| 2343 | leaf_generation = btrfs_header_generation(leaf); |
| 2344 | |
| 2345 | for (i = 0; i < nritems; i++) { |
| 2346 | u64 disk_bytenr; |
| 2347 | cond_resched(); |
| 2348 | |
| 2349 | btrfs_item_key_to_cpu(leaf, &key, i); |
| 2350 | if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) |
| 2351 | continue; |
| 2352 | fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); |
| 2353 | if (btrfs_file_extent_type(leaf, fi) == |
| 2354 | BTRFS_FILE_EXTENT_INLINE) |
| 2355 | continue; |
| 2356 | /* |
| 2357 | * FIXME make sure to insert a trans record that |
| 2358 | * repeats the snapshot del on crash |
| 2359 | */ |
| 2360 | disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| 2361 | if (disk_bytenr == 0) |
| 2362 | continue; |
| 2363 | |
| 2364 | mutex_lock(&root->fs_info->alloc_mutex); |
| 2365 | ret = __btrfs_free_extent(trans, root, disk_bytenr, |
| 2366 | btrfs_file_extent_disk_num_bytes(leaf, fi), |
| 2367 | leaf_owner, leaf_generation, |
| 2368 | key.objectid, key.offset, 0); |
| 2369 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 2370 | |
| 2371 | atomic_inc(&root->fs_info->throttle_gen); |
| 2372 | wake_up(&root->fs_info->transaction_throttle); |
| 2373 | cond_resched(); |
| 2374 | |
| 2375 | BUG_ON(ret); |
| 2376 | } |
| 2377 | return 0; |
| 2378 | } |
| 2379 | |
| 2380 | static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans, |
| 2381 | struct btrfs_root *root, |
| 2382 | struct btrfs_leaf_ref *ref) |
| 2383 | { |
| 2384 | int i; |
| 2385 | int ret; |
| 2386 | struct btrfs_extent_info *info = ref->extents; |
| 2387 | |
| 2388 | for (i = 0; i < ref->nritems; i++) { |
| 2389 | mutex_lock(&root->fs_info->alloc_mutex); |
| 2390 | ret = __btrfs_free_extent(trans, root, |
| 2391 | info->bytenr, info->num_bytes, |
| 2392 | ref->owner, ref->generation, |
| 2393 | info->objectid, info->offset, 0); |
| 2394 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 2395 | |
| 2396 | atomic_inc(&root->fs_info->throttle_gen); |
| 2397 | wake_up(&root->fs_info->transaction_throttle); |
| 2398 | cond_resched(); |
| 2399 | |
| 2400 | BUG_ON(ret); |
| 2401 | info++; |
| 2402 | } |
| 2403 | |
| 2404 | return 0; |
| 2405 | } |
| 2406 | |
| 2407 | int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len, |
| 2408 | u32 *refs) |
| 2409 | { |
| 2410 | int ret; |
| 2411 | |
| 2412 | ret = lookup_extent_ref(NULL, root, start, len, refs); |
| 2413 | BUG_ON(ret); |
| 2414 | |
| 2415 | #if 0 // some debugging code in case we see problems here |
| 2416 | /* if the refs count is one, it won't get increased again. But |
| 2417 | * if the ref count is > 1, someone may be decreasing it at |
| 2418 | * the same time we are. |
| 2419 | */ |
| 2420 | if (*refs != 1) { |
| 2421 | struct extent_buffer *eb = NULL; |
| 2422 | eb = btrfs_find_create_tree_block(root, start, len); |
| 2423 | if (eb) |
| 2424 | btrfs_tree_lock(eb); |
| 2425 | |
| 2426 | mutex_lock(&root->fs_info->alloc_mutex); |
| 2427 | ret = lookup_extent_ref(NULL, root, start, len, refs); |
| 2428 | BUG_ON(ret); |
| 2429 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 2430 | |
| 2431 | if (eb) { |
| 2432 | btrfs_tree_unlock(eb); |
| 2433 | free_extent_buffer(eb); |
| 2434 | } |
| 2435 | if (*refs == 1) { |
| 2436 | printk("block %llu went down to one during drop_snap\n", |
| 2437 | (unsigned long long)start); |
| 2438 | } |
| 2439 | |
| 2440 | } |
| 2441 | #endif |
| 2442 | |
| 2443 | cond_resched(); |
| 2444 | return ret; |
| 2445 | } |
| 2446 | |
| 2447 | /* |
| 2448 | * helper function for drop_snapshot, this walks down the tree dropping ref |
| 2449 | * counts as it goes. |
| 2450 | */ |
| 2451 | static int noinline walk_down_tree(struct btrfs_trans_handle *trans, |
| 2452 | struct btrfs_root *root, |
| 2453 | struct btrfs_path *path, int *level) |
| 2454 | { |
| 2455 | u64 root_owner; |
| 2456 | u64 root_gen; |
| 2457 | u64 bytenr; |
| 2458 | u64 ptr_gen; |
| 2459 | struct extent_buffer *next; |
| 2460 | struct extent_buffer *cur; |
| 2461 | struct extent_buffer *parent; |
| 2462 | struct btrfs_leaf_ref *ref; |
| 2463 | u32 blocksize; |
| 2464 | int ret; |
| 2465 | u32 refs; |
| 2466 | |
| 2467 | WARN_ON(*level < 0); |
| 2468 | WARN_ON(*level >= BTRFS_MAX_LEVEL); |
| 2469 | ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start, |
| 2470 | path->nodes[*level]->len, &refs); |
| 2471 | BUG_ON(ret); |
| 2472 | if (refs > 1) |
| 2473 | goto out; |
| 2474 | |
| 2475 | /* |
| 2476 | * walk down to the last node level and free all the leaves |
| 2477 | */ |
| 2478 | while(*level >= 0) { |
| 2479 | WARN_ON(*level < 0); |
| 2480 | WARN_ON(*level >= BTRFS_MAX_LEVEL); |
| 2481 | cur = path->nodes[*level]; |
| 2482 | |
| 2483 | if (btrfs_header_level(cur) != *level) |
| 2484 | WARN_ON(1); |
| 2485 | |
| 2486 | if (path->slots[*level] >= |
| 2487 | btrfs_header_nritems(cur)) |
| 2488 | break; |
| 2489 | if (*level == 0) { |
| 2490 | ret = drop_leaf_ref_no_cache(trans, root, cur); |
| 2491 | BUG_ON(ret); |
| 2492 | break; |
| 2493 | } |
| 2494 | bytenr = btrfs_node_blockptr(cur, path->slots[*level]); |
| 2495 | ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); |
| 2496 | blocksize = btrfs_level_size(root, *level - 1); |
| 2497 | |
| 2498 | ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs); |
| 2499 | BUG_ON(ret); |
| 2500 | if (refs != 1) { |
| 2501 | parent = path->nodes[*level]; |
| 2502 | root_owner = btrfs_header_owner(parent); |
| 2503 | root_gen = btrfs_header_generation(parent); |
| 2504 | path->slots[*level]++; |
| 2505 | |
| 2506 | mutex_lock(&root->fs_info->alloc_mutex); |
| 2507 | ret = __btrfs_free_extent(trans, root, bytenr, |
| 2508 | blocksize, root_owner, |
| 2509 | root_gen, 0, 0, 1); |
| 2510 | BUG_ON(ret); |
| 2511 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 2512 | |
| 2513 | atomic_inc(&root->fs_info->throttle_gen); |
| 2514 | wake_up(&root->fs_info->transaction_throttle); |
| 2515 | cond_resched(); |
| 2516 | |
| 2517 | continue; |
| 2518 | } |
| 2519 | /* |
| 2520 | * at this point, we have a single ref, and since the |
| 2521 | * only place referencing this extent is a dead root |
| 2522 | * the reference count should never go higher. |
| 2523 | * So, we don't need to check it again |
| 2524 | */ |
| 2525 | if (*level == 1) { |
| 2526 | struct btrfs_key key; |
| 2527 | btrfs_node_key_to_cpu(cur, &key, path->slots[*level]); |
| 2528 | ref = btrfs_lookup_leaf_ref(root, bytenr); |
| 2529 | if (ref) { |
| 2530 | ret = drop_leaf_ref(trans, root, ref); |
| 2531 | BUG_ON(ret); |
| 2532 | btrfs_remove_leaf_ref(root, ref); |
| 2533 | btrfs_free_leaf_ref(root, ref); |
| 2534 | *level = 0; |
| 2535 | break; |
| 2536 | } |
| 2537 | if (printk_ratelimit()) |
| 2538 | printk("leaf ref miss for bytenr %llu\n", |
| 2539 | (unsigned long long)bytenr); |
| 2540 | } |
| 2541 | next = btrfs_find_tree_block(root, bytenr, blocksize); |
| 2542 | if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) { |
| 2543 | free_extent_buffer(next); |
| 2544 | |
| 2545 | next = read_tree_block(root, bytenr, blocksize, |
| 2546 | ptr_gen); |
| 2547 | cond_resched(); |
| 2548 | #if 0 |
| 2549 | /* |
| 2550 | * this is a debugging check and can go away |
| 2551 | * the ref should never go all the way down to 1 |
| 2552 | * at this point |
| 2553 | */ |
| 2554 | ret = lookup_extent_ref(NULL, root, bytenr, blocksize, |
| 2555 | &refs); |
| 2556 | BUG_ON(ret); |
| 2557 | WARN_ON(refs != 1); |
| 2558 | #endif |
| 2559 | } |
| 2560 | WARN_ON(*level <= 0); |
| 2561 | if (path->nodes[*level-1]) |
| 2562 | free_extent_buffer(path->nodes[*level-1]); |
| 2563 | path->nodes[*level-1] = next; |
| 2564 | *level = btrfs_header_level(next); |
| 2565 | path->slots[*level] = 0; |
| 2566 | cond_resched(); |
| 2567 | } |
| 2568 | out: |
| 2569 | WARN_ON(*level < 0); |
| 2570 | WARN_ON(*level >= BTRFS_MAX_LEVEL); |
| 2571 | |
| 2572 | if (path->nodes[*level] == root->node) { |
| 2573 | parent = path->nodes[*level]; |
| 2574 | bytenr = path->nodes[*level]->start; |
| 2575 | } else { |
| 2576 | parent = path->nodes[*level + 1]; |
| 2577 | bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]); |
| 2578 | } |
| 2579 | |
| 2580 | blocksize = btrfs_level_size(root, *level); |
| 2581 | root_owner = btrfs_header_owner(parent); |
| 2582 | root_gen = btrfs_header_generation(parent); |
| 2583 | |
| 2584 | mutex_lock(&root->fs_info->alloc_mutex); |
| 2585 | ret = __btrfs_free_extent(trans, root, bytenr, blocksize, |
| 2586 | root_owner, root_gen, 0, 0, 1); |
| 2587 | free_extent_buffer(path->nodes[*level]); |
| 2588 | path->nodes[*level] = NULL; |
| 2589 | *level += 1; |
| 2590 | BUG_ON(ret); |
| 2591 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 2592 | |
| 2593 | cond_resched(); |
| 2594 | return 0; |
| 2595 | } |
| 2596 | |
| 2597 | /* |
| 2598 | * helper for dropping snapshots. This walks back up the tree in the path |
| 2599 | * to find the first node higher up where we haven't yet gone through |
| 2600 | * all the slots |
| 2601 | */ |
| 2602 | static int noinline walk_up_tree(struct btrfs_trans_handle *trans, |
| 2603 | struct btrfs_root *root, |
| 2604 | struct btrfs_path *path, int *level) |
| 2605 | { |
| 2606 | u64 root_owner; |
| 2607 | u64 root_gen; |
| 2608 | struct btrfs_root_item *root_item = &root->root_item; |
| 2609 | int i; |
| 2610 | int slot; |
| 2611 | int ret; |
| 2612 | |
| 2613 | for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { |
| 2614 | slot = path->slots[i]; |
| 2615 | if (slot < btrfs_header_nritems(path->nodes[i]) - 1) { |
| 2616 | struct extent_buffer *node; |
| 2617 | struct btrfs_disk_key disk_key; |
| 2618 | node = path->nodes[i]; |
| 2619 | path->slots[i]++; |
| 2620 | *level = i; |
| 2621 | WARN_ON(*level == 0); |
| 2622 | btrfs_node_key(node, &disk_key, path->slots[i]); |
| 2623 | memcpy(&root_item->drop_progress, |
| 2624 | &disk_key, sizeof(disk_key)); |
| 2625 | root_item->drop_level = i; |
| 2626 | return 0; |
| 2627 | } else { |
| 2628 | if (path->nodes[*level] == root->node) { |
| 2629 | root_owner = root->root_key.objectid; |
| 2630 | root_gen = |
| 2631 | btrfs_header_generation(path->nodes[*level]); |
| 2632 | } else { |
| 2633 | struct extent_buffer *node; |
| 2634 | node = path->nodes[*level + 1]; |
| 2635 | root_owner = btrfs_header_owner(node); |
| 2636 | root_gen = btrfs_header_generation(node); |
| 2637 | } |
| 2638 | ret = btrfs_free_extent(trans, root, |
| 2639 | path->nodes[*level]->start, |
| 2640 | path->nodes[*level]->len, |
| 2641 | root_owner, root_gen, 0, 0, 1); |
| 2642 | BUG_ON(ret); |
| 2643 | free_extent_buffer(path->nodes[*level]); |
| 2644 | path->nodes[*level] = NULL; |
| 2645 | *level = i + 1; |
| 2646 | } |
| 2647 | } |
| 2648 | return 1; |
| 2649 | } |
| 2650 | |
| 2651 | /* |
| 2652 | * drop the reference count on the tree rooted at 'snap'. This traverses |
| 2653 | * the tree freeing any blocks that have a ref count of zero after being |
| 2654 | * decremented. |
| 2655 | */ |
| 2656 | int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root |
| 2657 | *root) |
| 2658 | { |
| 2659 | int ret = 0; |
| 2660 | int wret; |
| 2661 | int level; |
| 2662 | struct btrfs_path *path; |
| 2663 | int i; |
| 2664 | int orig_level; |
| 2665 | struct btrfs_root_item *root_item = &root->root_item; |
| 2666 | |
| 2667 | WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex)); |
| 2668 | path = btrfs_alloc_path(); |
| 2669 | BUG_ON(!path); |
| 2670 | |
| 2671 | level = btrfs_header_level(root->node); |
| 2672 | orig_level = level; |
| 2673 | if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { |
| 2674 | path->nodes[level] = root->node; |
| 2675 | extent_buffer_get(root->node); |
| 2676 | path->slots[level] = 0; |
| 2677 | } else { |
| 2678 | struct btrfs_key key; |
| 2679 | struct btrfs_disk_key found_key; |
| 2680 | struct extent_buffer *node; |
| 2681 | |
| 2682 | btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); |
| 2683 | level = root_item->drop_level; |
| 2684 | path->lowest_level = level; |
| 2685 | wret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 2686 | if (wret < 0) { |
| 2687 | ret = wret; |
| 2688 | goto out; |
| 2689 | } |
| 2690 | node = path->nodes[level]; |
| 2691 | btrfs_node_key(node, &found_key, path->slots[level]); |
| 2692 | WARN_ON(memcmp(&found_key, &root_item->drop_progress, |
| 2693 | sizeof(found_key))); |
| 2694 | /* |
| 2695 | * unlock our path, this is safe because only this |
| 2696 | * function is allowed to delete this snapshot |
| 2697 | */ |
| 2698 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
| 2699 | if (path->nodes[i] && path->locks[i]) { |
| 2700 | path->locks[i] = 0; |
| 2701 | btrfs_tree_unlock(path->nodes[i]); |
| 2702 | } |
| 2703 | } |
| 2704 | } |
| 2705 | while(1) { |
| 2706 | wret = walk_down_tree(trans, root, path, &level); |
| 2707 | if (wret > 0) |
| 2708 | break; |
| 2709 | if (wret < 0) |
| 2710 | ret = wret; |
| 2711 | |
| 2712 | wret = walk_up_tree(trans, root, path, &level); |
| 2713 | if (wret > 0) |
| 2714 | break; |
| 2715 | if (wret < 0) |
| 2716 | ret = wret; |
| 2717 | if (trans->transaction->in_commit) { |
| 2718 | ret = -EAGAIN; |
| 2719 | break; |
| 2720 | } |
| 2721 | atomic_inc(&root->fs_info->throttle_gen); |
| 2722 | wake_up(&root->fs_info->transaction_throttle); |
| 2723 | } |
| 2724 | for (i = 0; i <= orig_level; i++) { |
| 2725 | if (path->nodes[i]) { |
| 2726 | free_extent_buffer(path->nodes[i]); |
| 2727 | path->nodes[i] = NULL; |
| 2728 | } |
| 2729 | } |
| 2730 | out: |
| 2731 | btrfs_free_path(path); |
| 2732 | return ret; |
| 2733 | } |
| 2734 | |
| 2735 | int btrfs_free_block_groups(struct btrfs_fs_info *info) |
| 2736 | { |
| 2737 | u64 start; |
| 2738 | u64 end; |
| 2739 | u64 ptr; |
| 2740 | int ret; |
| 2741 | |
| 2742 | mutex_lock(&info->alloc_mutex); |
| 2743 | while(1) { |
| 2744 | ret = find_first_extent_bit(&info->block_group_cache, 0, |
| 2745 | &start, &end, (unsigned int)-1); |
| 2746 | if (ret) |
| 2747 | break; |
| 2748 | ret = get_state_private(&info->block_group_cache, start, &ptr); |
| 2749 | if (!ret) |
| 2750 | kfree((void *)(unsigned long)ptr); |
| 2751 | clear_extent_bits(&info->block_group_cache, start, |
| 2752 | end, (unsigned int)-1, GFP_NOFS); |
| 2753 | } |
| 2754 | while(1) { |
| 2755 | ret = find_first_extent_bit(&info->free_space_cache, 0, |
| 2756 | &start, &end, EXTENT_DIRTY); |
| 2757 | if (ret) |
| 2758 | break; |
| 2759 | clear_extent_dirty(&info->free_space_cache, start, |
| 2760 | end, GFP_NOFS); |
| 2761 | } |
| 2762 | mutex_unlock(&info->alloc_mutex); |
| 2763 | return 0; |
| 2764 | } |
| 2765 | |
| 2766 | static unsigned long calc_ra(unsigned long start, unsigned long last, |
| 2767 | unsigned long nr) |
| 2768 | { |
| 2769 | return min(last, start + nr - 1); |
| 2770 | } |
| 2771 | |
| 2772 | static int noinline relocate_inode_pages(struct inode *inode, u64 start, |
| 2773 | u64 len) |
| 2774 | { |
| 2775 | u64 page_start; |
| 2776 | u64 page_end; |
| 2777 | unsigned long last_index; |
| 2778 | unsigned long i; |
| 2779 | struct page *page; |
| 2780 | struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; |
| 2781 | struct file_ra_state *ra; |
| 2782 | unsigned long total_read = 0; |
| 2783 | unsigned long ra_pages; |
| 2784 | struct btrfs_ordered_extent *ordered; |
| 2785 | struct btrfs_trans_handle *trans; |
| 2786 | |
| 2787 | ra = kzalloc(sizeof(*ra), GFP_NOFS); |
| 2788 | |
| 2789 | mutex_lock(&inode->i_mutex); |
| 2790 | i = start >> PAGE_CACHE_SHIFT; |
| 2791 | last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; |
| 2792 | |
| 2793 | ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages; |
| 2794 | |
| 2795 | file_ra_state_init(ra, inode->i_mapping); |
| 2796 | |
| 2797 | for (; i <= last_index; i++) { |
| 2798 | if (total_read % ra_pages == 0) { |
| 2799 | btrfs_force_ra(inode->i_mapping, ra, NULL, i, |
| 2800 | calc_ra(i, last_index, ra_pages)); |
| 2801 | } |
| 2802 | total_read++; |
| 2803 | again: |
| 2804 | if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) |
| 2805 | goto truncate_racing; |
| 2806 | page = grab_cache_page(inode->i_mapping, i); |
| 2807 | if (!page) { |
| 2808 | goto out_unlock; |
| 2809 | } |
| 2810 | if (!PageUptodate(page)) { |
| 2811 | btrfs_readpage(NULL, page); |
| 2812 | lock_page(page); |
| 2813 | if (!PageUptodate(page)) { |
| 2814 | unlock_page(page); |
| 2815 | page_cache_release(page); |
| 2816 | goto out_unlock; |
| 2817 | } |
| 2818 | } |
| 2819 | wait_on_page_writeback(page); |
| 2820 | |
| 2821 | page_start = (u64)page->index << PAGE_CACHE_SHIFT; |
| 2822 | page_end = page_start + PAGE_CACHE_SIZE - 1; |
| 2823 | lock_extent(io_tree, page_start, page_end, GFP_NOFS); |
| 2824 | |
| 2825 | ordered = btrfs_lookup_ordered_extent(inode, page_start); |
| 2826 | if (ordered) { |
| 2827 | unlock_extent(io_tree, page_start, page_end, GFP_NOFS); |
| 2828 | unlock_page(page); |
| 2829 | page_cache_release(page); |
| 2830 | btrfs_start_ordered_extent(inode, ordered, 1); |
| 2831 | btrfs_put_ordered_extent(ordered); |
| 2832 | goto again; |
| 2833 | } |
| 2834 | set_page_extent_mapped(page); |
| 2835 | |
| 2836 | /* |
| 2837 | * make sure page_mkwrite is called for this page if userland |
| 2838 | * wants to change it from mmap |
| 2839 | */ |
| 2840 | clear_page_dirty_for_io(page); |
| 2841 | |
| 2842 | btrfs_set_extent_delalloc(inode, page_start, page_end); |
| 2843 | set_page_dirty(page); |
| 2844 | |
| 2845 | unlock_extent(io_tree, page_start, page_end, GFP_NOFS); |
| 2846 | unlock_page(page); |
| 2847 | page_cache_release(page); |
| 2848 | } |
| 2849 | |
| 2850 | out_unlock: |
| 2851 | /* we have to start the IO in order to get the ordered extents |
| 2852 | * instantiated. This allows the relocation to code to wait |
| 2853 | * for all the ordered extents to hit the disk. |
| 2854 | * |
| 2855 | * Otherwise, it would constantly loop over the same extents |
| 2856 | * because the old ones don't get deleted until the IO is |
| 2857 | * started |
| 2858 | */ |
| 2859 | btrfs_fdatawrite_range(inode->i_mapping, start, start + len - 1, |
| 2860 | WB_SYNC_NONE); |
| 2861 | kfree(ra); |
| 2862 | trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1); |
| 2863 | if (trans) { |
| 2864 | btrfs_end_transaction(trans, BTRFS_I(inode)->root); |
| 2865 | mark_inode_dirty(inode); |
| 2866 | } |
| 2867 | mutex_unlock(&inode->i_mutex); |
| 2868 | return 0; |
| 2869 | |
| 2870 | truncate_racing: |
| 2871 | vmtruncate(inode, inode->i_size); |
| 2872 | balance_dirty_pages_ratelimited_nr(inode->i_mapping, |
| 2873 | total_read); |
| 2874 | goto out_unlock; |
| 2875 | } |
| 2876 | |
| 2877 | /* |
| 2878 | * The back references tell us which tree holds a ref on a block, |
| 2879 | * but it is possible for the tree root field in the reference to |
| 2880 | * reflect the original root before a snapshot was made. In this |
| 2881 | * case we should search through all the children of a given root |
| 2882 | * to find potential holders of references on a block. |
| 2883 | * |
| 2884 | * Instead, we do something a little less fancy and just search |
| 2885 | * all the roots for a given key/block combination. |
| 2886 | */ |
| 2887 | static int find_root_for_ref(struct btrfs_root *root, |
| 2888 | struct btrfs_path *path, |
| 2889 | struct btrfs_key *key0, |
| 2890 | int level, |
| 2891 | int file_key, |
| 2892 | struct btrfs_root **found_root, |
| 2893 | u64 bytenr) |
| 2894 | { |
| 2895 | struct btrfs_key root_location; |
| 2896 | struct btrfs_root *cur_root = *found_root; |
| 2897 | struct btrfs_file_extent_item *file_extent; |
| 2898 | u64 root_search_start = BTRFS_FS_TREE_OBJECTID; |
| 2899 | u64 found_bytenr; |
| 2900 | int ret; |
| 2901 | |
| 2902 | root_location.offset = (u64)-1; |
| 2903 | root_location.type = BTRFS_ROOT_ITEM_KEY; |
| 2904 | path->lowest_level = level; |
| 2905 | path->reada = 0; |
| 2906 | while(1) { |
| 2907 | ret = btrfs_search_slot(NULL, cur_root, key0, path, 0, 0); |
| 2908 | found_bytenr = 0; |
| 2909 | if (ret == 0 && file_key) { |
| 2910 | struct extent_buffer *leaf = path->nodes[0]; |
| 2911 | file_extent = btrfs_item_ptr(leaf, path->slots[0], |
| 2912 | struct btrfs_file_extent_item); |
| 2913 | if (btrfs_file_extent_type(leaf, file_extent) == |
| 2914 | BTRFS_FILE_EXTENT_REG) { |
| 2915 | found_bytenr = |
| 2916 | btrfs_file_extent_disk_bytenr(leaf, |
| 2917 | file_extent); |
| 2918 | } |
| 2919 | } else if (!file_key) { |
| 2920 | if (path->nodes[level]) |
| 2921 | found_bytenr = path->nodes[level]->start; |
| 2922 | } |
| 2923 | |
| 2924 | btrfs_release_path(cur_root, path); |
| 2925 | |
| 2926 | if (found_bytenr == bytenr) { |
| 2927 | *found_root = cur_root; |
| 2928 | ret = 0; |
| 2929 | goto out; |
| 2930 | } |
| 2931 | ret = btrfs_search_root(root->fs_info->tree_root, |
| 2932 | root_search_start, &root_search_start); |
| 2933 | if (ret) |
| 2934 | break; |
| 2935 | |
| 2936 | root_location.objectid = root_search_start; |
| 2937 | cur_root = btrfs_read_fs_root_no_name(root->fs_info, |
| 2938 | &root_location); |
| 2939 | if (!cur_root) { |
| 2940 | ret = 1; |
| 2941 | break; |
| 2942 | } |
| 2943 | } |
| 2944 | out: |
| 2945 | path->lowest_level = 0; |
| 2946 | return ret; |
| 2947 | } |
| 2948 | |
| 2949 | /* |
| 2950 | * note, this releases the path |
| 2951 | */ |
| 2952 | static int noinline relocate_one_reference(struct btrfs_root *extent_root, |
| 2953 | struct btrfs_path *path, |
| 2954 | struct btrfs_key *extent_key, |
| 2955 | u64 *last_file_objectid, |
| 2956 | u64 *last_file_offset, |
| 2957 | u64 *last_file_root, |
| 2958 | u64 last_extent) |
| 2959 | { |
| 2960 | struct inode *inode; |
| 2961 | struct btrfs_root *found_root; |
| 2962 | struct btrfs_key root_location; |
| 2963 | struct btrfs_key found_key; |
| 2964 | struct btrfs_extent_ref *ref; |
| 2965 | u64 ref_root; |
| 2966 | u64 ref_gen; |
| 2967 | u64 ref_objectid; |
| 2968 | u64 ref_offset; |
| 2969 | int ret; |
| 2970 | int level; |
| 2971 | |
| 2972 | WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); |
| 2973 | |
| 2974 | ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| 2975 | struct btrfs_extent_ref); |
| 2976 | ref_root = btrfs_ref_root(path->nodes[0], ref); |
| 2977 | ref_gen = btrfs_ref_generation(path->nodes[0], ref); |
| 2978 | ref_objectid = btrfs_ref_objectid(path->nodes[0], ref); |
| 2979 | ref_offset = btrfs_ref_offset(path->nodes[0], ref); |
| 2980 | btrfs_release_path(extent_root, path); |
| 2981 | |
| 2982 | root_location.objectid = ref_root; |
| 2983 | if (ref_gen == 0) |
| 2984 | root_location.offset = 0; |
| 2985 | else |
| 2986 | root_location.offset = (u64)-1; |
| 2987 | root_location.type = BTRFS_ROOT_ITEM_KEY; |
| 2988 | |
| 2989 | found_root = btrfs_read_fs_root_no_name(extent_root->fs_info, |
| 2990 | &root_location); |
| 2991 | BUG_ON(!found_root); |
| 2992 | mutex_unlock(&extent_root->fs_info->alloc_mutex); |
| 2993 | |
| 2994 | if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) { |
| 2995 | found_key.objectid = ref_objectid; |
| 2996 | found_key.type = BTRFS_EXTENT_DATA_KEY; |
| 2997 | found_key.offset = ref_offset; |
| 2998 | level = 0; |
| 2999 | |
| 3000 | if (last_extent == extent_key->objectid && |
| 3001 | *last_file_objectid == ref_objectid && |
| 3002 | *last_file_offset == ref_offset && |
| 3003 | *last_file_root == ref_root) |
| 3004 | goto out; |
| 3005 | |
| 3006 | ret = find_root_for_ref(extent_root, path, &found_key, |
| 3007 | level, 1, &found_root, |
| 3008 | extent_key->objectid); |
| 3009 | |
| 3010 | if (ret) |
| 3011 | goto out; |
| 3012 | |
| 3013 | if (last_extent == extent_key->objectid && |
| 3014 | *last_file_objectid == ref_objectid && |
| 3015 | *last_file_offset == ref_offset && |
| 3016 | *last_file_root == ref_root) |
| 3017 | goto out; |
| 3018 | |
| 3019 | inode = btrfs_iget_locked(extent_root->fs_info->sb, |
| 3020 | ref_objectid, found_root); |
| 3021 | if (inode->i_state & I_NEW) { |
| 3022 | /* the inode and parent dir are two different roots */ |
| 3023 | BTRFS_I(inode)->root = found_root; |
| 3024 | BTRFS_I(inode)->location.objectid = ref_objectid; |
| 3025 | BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; |
| 3026 | BTRFS_I(inode)->location.offset = 0; |
| 3027 | btrfs_read_locked_inode(inode); |
| 3028 | unlock_new_inode(inode); |
| 3029 | |
| 3030 | } |
| 3031 | /* this can happen if the reference is not against |
| 3032 | * the latest version of the tree root |
| 3033 | */ |
| 3034 | if (is_bad_inode(inode)) |
| 3035 | goto out; |
| 3036 | |
| 3037 | *last_file_objectid = inode->i_ino; |
| 3038 | *last_file_root = found_root->root_key.objectid; |
| 3039 | *last_file_offset = ref_offset; |
| 3040 | |
| 3041 | relocate_inode_pages(inode, ref_offset, extent_key->offset); |
| 3042 | iput(inode); |
| 3043 | } else { |
| 3044 | struct btrfs_trans_handle *trans; |
| 3045 | struct extent_buffer *eb; |
| 3046 | int needs_lock = 0; |
| 3047 | |
| 3048 | eb = read_tree_block(found_root, extent_key->objectid, |
| 3049 | extent_key->offset, 0); |
| 3050 | btrfs_tree_lock(eb); |
| 3051 | level = btrfs_header_level(eb); |
| 3052 | |
| 3053 | if (level == 0) |
| 3054 | btrfs_item_key_to_cpu(eb, &found_key, 0); |
| 3055 | else |
| 3056 | btrfs_node_key_to_cpu(eb, &found_key, 0); |
| 3057 | |
| 3058 | btrfs_tree_unlock(eb); |
| 3059 | free_extent_buffer(eb); |
| 3060 | |
| 3061 | ret = find_root_for_ref(extent_root, path, &found_key, |
| 3062 | level, 0, &found_root, |
| 3063 | extent_key->objectid); |
| 3064 | |
| 3065 | if (ret) |
| 3066 | goto out; |
| 3067 | |
| 3068 | /* |
| 3069 | * right here almost anything could happen to our key, |
| 3070 | * but that's ok. The cow below will either relocate it |
| 3071 | * or someone else will have relocated it. Either way, |
| 3072 | * it is in a different spot than it was before and |
| 3073 | * we're happy. |
| 3074 | */ |
| 3075 | |
| 3076 | trans = btrfs_start_transaction(found_root, 1); |
| 3077 | |
| 3078 | if (found_root == extent_root->fs_info->extent_root || |
| 3079 | found_root == extent_root->fs_info->chunk_root || |
| 3080 | found_root == extent_root->fs_info->dev_root) { |
| 3081 | needs_lock = 1; |
| 3082 | mutex_lock(&extent_root->fs_info->alloc_mutex); |
| 3083 | } |
| 3084 | |
| 3085 | path->lowest_level = level; |
| 3086 | path->reada = 2; |
| 3087 | ret = btrfs_search_slot(trans, found_root, &found_key, path, |
| 3088 | 0, 1); |
| 3089 | path->lowest_level = 0; |
| 3090 | btrfs_release_path(found_root, path); |
| 3091 | |
| 3092 | if (found_root == found_root->fs_info->extent_root) |
| 3093 | btrfs_extent_post_op(trans, found_root); |
| 3094 | if (needs_lock) |
| 3095 | mutex_unlock(&extent_root->fs_info->alloc_mutex); |
| 3096 | |
| 3097 | btrfs_end_transaction(trans, found_root); |
| 3098 | |
| 3099 | } |
| 3100 | out: |
| 3101 | mutex_lock(&extent_root->fs_info->alloc_mutex); |
| 3102 | return 0; |
| 3103 | } |
| 3104 | |
| 3105 | static int noinline del_extent_zero(struct btrfs_root *extent_root, |
| 3106 | struct btrfs_path *path, |
| 3107 | struct btrfs_key *extent_key) |
| 3108 | { |
| 3109 | int ret; |
| 3110 | struct btrfs_trans_handle *trans; |
| 3111 | |
| 3112 | trans = btrfs_start_transaction(extent_root, 1); |
| 3113 | ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1); |
| 3114 | if (ret > 0) { |
| 3115 | ret = -EIO; |
| 3116 | goto out; |
| 3117 | } |
| 3118 | if (ret < 0) |
| 3119 | goto out; |
| 3120 | ret = btrfs_del_item(trans, extent_root, path); |
| 3121 | out: |
| 3122 | btrfs_end_transaction(trans, extent_root); |
| 3123 | return ret; |
| 3124 | } |
| 3125 | |
| 3126 | static int noinline relocate_one_extent(struct btrfs_root *extent_root, |
| 3127 | struct btrfs_path *path, |
| 3128 | struct btrfs_key *extent_key) |
| 3129 | { |
| 3130 | struct btrfs_key key; |
| 3131 | struct btrfs_key found_key; |
| 3132 | struct extent_buffer *leaf; |
| 3133 | u64 last_file_objectid = 0; |
| 3134 | u64 last_file_root = 0; |
| 3135 | u64 last_file_offset = (u64)-1; |
| 3136 | u64 last_extent = 0; |
| 3137 | u32 nritems; |
| 3138 | u32 item_size; |
| 3139 | int ret = 0; |
| 3140 | |
| 3141 | if (extent_key->objectid == 0) { |
| 3142 | ret = del_extent_zero(extent_root, path, extent_key); |
| 3143 | goto out; |
| 3144 | } |
| 3145 | key.objectid = extent_key->objectid; |
| 3146 | key.type = BTRFS_EXTENT_REF_KEY; |
| 3147 | key.offset = 0; |
| 3148 | |
| 3149 | while(1) { |
| 3150 | ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| 3151 | |
| 3152 | if (ret < 0) |
| 3153 | goto out; |
| 3154 | |
| 3155 | ret = 0; |
| 3156 | leaf = path->nodes[0]; |
| 3157 | nritems = btrfs_header_nritems(leaf); |
| 3158 | if (path->slots[0] == nritems) { |
| 3159 | ret = btrfs_next_leaf(extent_root, path); |
| 3160 | if (ret > 0) { |
| 3161 | ret = 0; |
| 3162 | goto out; |
| 3163 | } |
| 3164 | if (ret < 0) |
| 3165 | goto out; |
| 3166 | leaf = path->nodes[0]; |
| 3167 | } |
| 3168 | |
| 3169 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 3170 | if (found_key.objectid != extent_key->objectid) { |
| 3171 | break; |
| 3172 | } |
| 3173 | |
| 3174 | if (found_key.type != BTRFS_EXTENT_REF_KEY) { |
| 3175 | break; |
| 3176 | } |
| 3177 | |
| 3178 | key.offset = found_key.offset + 1; |
| 3179 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| 3180 | |
| 3181 | ret = relocate_one_reference(extent_root, path, extent_key, |
| 3182 | &last_file_objectid, |
| 3183 | &last_file_offset, |
| 3184 | &last_file_root, last_extent); |
| 3185 | if (ret) |
| 3186 | goto out; |
| 3187 | last_extent = extent_key->objectid; |
| 3188 | } |
| 3189 | ret = 0; |
| 3190 | out: |
| 3191 | btrfs_release_path(extent_root, path); |
| 3192 | return ret; |
| 3193 | } |
| 3194 | |
| 3195 | static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) |
| 3196 | { |
| 3197 | u64 num_devices; |
| 3198 | u64 stripped = BTRFS_BLOCK_GROUP_RAID0 | |
| 3199 | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; |
| 3200 | |
| 3201 | num_devices = root->fs_info->fs_devices->num_devices; |
| 3202 | if (num_devices == 1) { |
| 3203 | stripped |= BTRFS_BLOCK_GROUP_DUP; |
| 3204 | stripped = flags & ~stripped; |
| 3205 | |
| 3206 | /* turn raid0 into single device chunks */ |
| 3207 | if (flags & BTRFS_BLOCK_GROUP_RAID0) |
| 3208 | return stripped; |
| 3209 | |
| 3210 | /* turn mirroring into duplication */ |
| 3211 | if (flags & (BTRFS_BLOCK_GROUP_RAID1 | |
| 3212 | BTRFS_BLOCK_GROUP_RAID10)) |
| 3213 | return stripped | BTRFS_BLOCK_GROUP_DUP; |
| 3214 | return flags; |
| 3215 | } else { |
| 3216 | /* they already had raid on here, just return */ |
| 3217 | if (flags & stripped) |
| 3218 | return flags; |
| 3219 | |
| 3220 | stripped |= BTRFS_BLOCK_GROUP_DUP; |
| 3221 | stripped = flags & ~stripped; |
| 3222 | |
| 3223 | /* switch duplicated blocks with raid1 */ |
| 3224 | if (flags & BTRFS_BLOCK_GROUP_DUP) |
| 3225 | return stripped | BTRFS_BLOCK_GROUP_RAID1; |
| 3226 | |
| 3227 | /* turn single device chunks into raid0 */ |
| 3228 | return stripped | BTRFS_BLOCK_GROUP_RAID0; |
| 3229 | } |
| 3230 | return flags; |
| 3231 | } |
| 3232 | |
| 3233 | int __alloc_chunk_for_shrink(struct btrfs_root *root, |
| 3234 | struct btrfs_block_group_cache *shrink_block_group, |
| 3235 | int force) |
| 3236 | { |
| 3237 | struct btrfs_trans_handle *trans; |
| 3238 | u64 new_alloc_flags; |
| 3239 | u64 calc; |
| 3240 | |
| 3241 | spin_lock(&shrink_block_group->lock); |
| 3242 | if (btrfs_block_group_used(&shrink_block_group->item) > 0) { |
| 3243 | spin_unlock(&shrink_block_group->lock); |
| 3244 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3245 | |
| 3246 | trans = btrfs_start_transaction(root, 1); |
| 3247 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3248 | spin_lock(&shrink_block_group->lock); |
| 3249 | |
| 3250 | new_alloc_flags = update_block_group_flags(root, |
| 3251 | shrink_block_group->flags); |
| 3252 | if (new_alloc_flags != shrink_block_group->flags) { |
| 3253 | calc = |
| 3254 | btrfs_block_group_used(&shrink_block_group->item); |
| 3255 | } else { |
| 3256 | calc = shrink_block_group->key.offset; |
| 3257 | } |
| 3258 | spin_unlock(&shrink_block_group->lock); |
| 3259 | |
| 3260 | do_chunk_alloc(trans, root->fs_info->extent_root, |
| 3261 | calc + 2 * 1024 * 1024, new_alloc_flags, force); |
| 3262 | |
| 3263 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3264 | btrfs_end_transaction(trans, root); |
| 3265 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3266 | } else |
| 3267 | spin_unlock(&shrink_block_group->lock); |
| 3268 | return 0; |
| 3269 | } |
| 3270 | |
| 3271 | int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start) |
| 3272 | { |
| 3273 | struct btrfs_trans_handle *trans; |
| 3274 | struct btrfs_root *tree_root = root->fs_info->tree_root; |
| 3275 | struct btrfs_path *path; |
| 3276 | u64 cur_byte; |
| 3277 | u64 total_found; |
| 3278 | u64 shrink_last_byte; |
| 3279 | struct btrfs_block_group_cache *shrink_block_group; |
| 3280 | struct btrfs_fs_info *info = root->fs_info; |
| 3281 | struct btrfs_key key; |
| 3282 | struct btrfs_key found_key; |
| 3283 | struct extent_buffer *leaf; |
| 3284 | u32 nritems; |
| 3285 | int ret; |
| 3286 | int progress; |
| 3287 | |
| 3288 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3289 | shrink_block_group = btrfs_lookup_block_group(root->fs_info, |
| 3290 | shrink_start); |
| 3291 | BUG_ON(!shrink_block_group); |
| 3292 | |
| 3293 | shrink_last_byte = shrink_block_group->key.objectid + |
| 3294 | shrink_block_group->key.offset; |
| 3295 | |
| 3296 | shrink_block_group->space_info->total_bytes -= |
| 3297 | shrink_block_group->key.offset; |
| 3298 | path = btrfs_alloc_path(); |
| 3299 | root = root->fs_info->extent_root; |
| 3300 | path->reada = 2; |
| 3301 | |
| 3302 | printk("btrfs relocating block group %llu flags %llu\n", |
| 3303 | (unsigned long long)shrink_start, |
| 3304 | (unsigned long long)shrink_block_group->flags); |
| 3305 | |
| 3306 | __alloc_chunk_for_shrink(root, shrink_block_group, 1); |
| 3307 | |
| 3308 | again: |
| 3309 | |
| 3310 | shrink_block_group->ro = 1; |
| 3311 | |
| 3312 | total_found = 0; |
| 3313 | progress = 0; |
| 3314 | key.objectid = shrink_start; |
| 3315 | key.offset = 0; |
| 3316 | key.type = 0; |
| 3317 | cur_byte = key.objectid; |
| 3318 | |
| 3319 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3320 | |
| 3321 | btrfs_start_delalloc_inodes(root); |
| 3322 | btrfs_wait_ordered_extents(tree_root, 0); |
| 3323 | |
| 3324 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3325 | |
| 3326 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 3327 | if (ret < 0) |
| 3328 | goto out; |
| 3329 | |
| 3330 | ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); |
| 3331 | if (ret < 0) |
| 3332 | goto out; |
| 3333 | |
| 3334 | if (ret == 0) { |
| 3335 | leaf = path->nodes[0]; |
| 3336 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 3337 | if (found_key.objectid + found_key.offset > shrink_start && |
| 3338 | found_key.objectid < shrink_last_byte) { |
| 3339 | cur_byte = found_key.objectid; |
| 3340 | key.objectid = cur_byte; |
| 3341 | } |
| 3342 | } |
| 3343 | btrfs_release_path(root, path); |
| 3344 | |
| 3345 | while(1) { |
| 3346 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 3347 | if (ret < 0) |
| 3348 | goto out; |
| 3349 | |
| 3350 | next: |
| 3351 | leaf = path->nodes[0]; |
| 3352 | nritems = btrfs_header_nritems(leaf); |
| 3353 | if (path->slots[0] >= nritems) { |
| 3354 | ret = btrfs_next_leaf(root, path); |
| 3355 | if (ret < 0) |
| 3356 | goto out; |
| 3357 | if (ret == 1) { |
| 3358 | ret = 0; |
| 3359 | break; |
| 3360 | } |
| 3361 | leaf = path->nodes[0]; |
| 3362 | nritems = btrfs_header_nritems(leaf); |
| 3363 | } |
| 3364 | |
| 3365 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 3366 | |
| 3367 | if (found_key.objectid >= shrink_last_byte) |
| 3368 | break; |
| 3369 | |
| 3370 | if (progress && need_resched()) { |
| 3371 | memcpy(&key, &found_key, sizeof(key)); |
| 3372 | cond_resched(); |
| 3373 | btrfs_release_path(root, path); |
| 3374 | btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 3375 | progress = 0; |
| 3376 | goto next; |
| 3377 | } |
| 3378 | progress = 1; |
| 3379 | |
| 3380 | if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY || |
| 3381 | found_key.objectid + found_key.offset <= cur_byte) { |
| 3382 | memcpy(&key, &found_key, sizeof(key)); |
| 3383 | key.offset++; |
| 3384 | path->slots[0]++; |
| 3385 | goto next; |
| 3386 | } |
| 3387 | |
| 3388 | total_found++; |
| 3389 | cur_byte = found_key.objectid + found_key.offset; |
| 3390 | key.objectid = cur_byte; |
| 3391 | btrfs_release_path(root, path); |
| 3392 | ret = relocate_one_extent(root, path, &found_key); |
| 3393 | __alloc_chunk_for_shrink(root, shrink_block_group, 0); |
| 3394 | } |
| 3395 | |
| 3396 | btrfs_release_path(root, path); |
| 3397 | |
| 3398 | if (total_found > 0) { |
| 3399 | printk("btrfs relocate found %llu last extent was %llu\n", |
| 3400 | (unsigned long long)total_found, |
| 3401 | (unsigned long long)found_key.objectid); |
| 3402 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3403 | trans = btrfs_start_transaction(tree_root, 1); |
| 3404 | btrfs_commit_transaction(trans, tree_root); |
| 3405 | |
| 3406 | btrfs_clean_old_snapshots(tree_root); |
| 3407 | |
| 3408 | btrfs_start_delalloc_inodes(root); |
| 3409 | btrfs_wait_ordered_extents(tree_root, 0); |
| 3410 | |
| 3411 | trans = btrfs_start_transaction(tree_root, 1); |
| 3412 | btrfs_commit_transaction(trans, tree_root); |
| 3413 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3414 | goto again; |
| 3415 | } |
| 3416 | |
| 3417 | /* |
| 3418 | * we've freed all the extents, now remove the block |
| 3419 | * group item from the tree |
| 3420 | */ |
| 3421 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3422 | |
| 3423 | trans = btrfs_start_transaction(root, 1); |
| 3424 | |
| 3425 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3426 | memcpy(&key, &shrink_block_group->key, sizeof(key)); |
| 3427 | |
| 3428 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| 3429 | if (ret > 0) |
| 3430 | ret = -EIO; |
| 3431 | if (ret < 0) { |
| 3432 | btrfs_end_transaction(trans, root); |
| 3433 | goto out; |
| 3434 | } |
| 3435 | |
| 3436 | clear_extent_bits(&info->block_group_cache, key.objectid, |
| 3437 | key.objectid + key.offset - 1, |
| 3438 | (unsigned int)-1, GFP_NOFS); |
| 3439 | |
| 3440 | |
| 3441 | clear_extent_bits(&info->free_space_cache, |
| 3442 | key.objectid, key.objectid + key.offset - 1, |
| 3443 | (unsigned int)-1, GFP_NOFS); |
| 3444 | |
| 3445 | /* |
| 3446 | memset(shrink_block_group, 0, sizeof(*shrink_block_group)); |
| 3447 | kfree(shrink_block_group); |
| 3448 | */ |
| 3449 | |
| 3450 | btrfs_del_item(trans, root, path); |
| 3451 | btrfs_release_path(root, path); |
| 3452 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3453 | btrfs_commit_transaction(trans, root); |
| 3454 | |
| 3455 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3456 | |
| 3457 | /* the code to unpin extents might set a few bits in the free |
| 3458 | * space cache for this range again |
| 3459 | */ |
| 3460 | clear_extent_bits(&info->free_space_cache, |
| 3461 | key.objectid, key.objectid + key.offset - 1, |
| 3462 | (unsigned int)-1, GFP_NOFS); |
| 3463 | out: |
| 3464 | btrfs_free_path(path); |
| 3465 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3466 | return ret; |
| 3467 | } |
| 3468 | |
| 3469 | int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path, |
| 3470 | struct btrfs_key *key) |
| 3471 | { |
| 3472 | int ret = 0; |
| 3473 | struct btrfs_key found_key; |
| 3474 | struct extent_buffer *leaf; |
| 3475 | int slot; |
| 3476 | |
| 3477 | ret = btrfs_search_slot(NULL, root, key, path, 0, 0); |
| 3478 | if (ret < 0) |
| 3479 | goto out; |
| 3480 | |
| 3481 | while(1) { |
| 3482 | slot = path->slots[0]; |
| 3483 | leaf = path->nodes[0]; |
| 3484 | if (slot >= btrfs_header_nritems(leaf)) { |
| 3485 | ret = btrfs_next_leaf(root, path); |
| 3486 | if (ret == 0) |
| 3487 | continue; |
| 3488 | if (ret < 0) |
| 3489 | goto out; |
| 3490 | break; |
| 3491 | } |
| 3492 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
| 3493 | |
| 3494 | if (found_key.objectid >= key->objectid && |
| 3495 | found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { |
| 3496 | ret = 0; |
| 3497 | goto out; |
| 3498 | } |
| 3499 | path->slots[0]++; |
| 3500 | } |
| 3501 | ret = -ENOENT; |
| 3502 | out: |
| 3503 | return ret; |
| 3504 | } |
| 3505 | |
| 3506 | int btrfs_read_block_groups(struct btrfs_root *root) |
| 3507 | { |
| 3508 | struct btrfs_path *path; |
| 3509 | int ret; |
| 3510 | int bit; |
| 3511 | struct btrfs_block_group_cache *cache; |
| 3512 | struct btrfs_fs_info *info = root->fs_info; |
| 3513 | struct btrfs_space_info *space_info; |
| 3514 | struct extent_io_tree *block_group_cache; |
| 3515 | struct btrfs_key key; |
| 3516 | struct btrfs_key found_key; |
| 3517 | struct extent_buffer *leaf; |
| 3518 | |
| 3519 | block_group_cache = &info->block_group_cache; |
| 3520 | root = info->extent_root; |
| 3521 | key.objectid = 0; |
| 3522 | key.offset = 0; |
| 3523 | btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY); |
| 3524 | path = btrfs_alloc_path(); |
| 3525 | if (!path) |
| 3526 | return -ENOMEM; |
| 3527 | |
| 3528 | mutex_lock(&root->fs_info->alloc_mutex); |
| 3529 | while(1) { |
| 3530 | ret = find_first_block_group(root, path, &key); |
| 3531 | if (ret > 0) { |
| 3532 | ret = 0; |
| 3533 | goto error; |
| 3534 | } |
| 3535 | if (ret != 0) |
| 3536 | goto error; |
| 3537 | |
| 3538 | leaf = path->nodes[0]; |
| 3539 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| 3540 | cache = kzalloc(sizeof(*cache), GFP_NOFS); |
| 3541 | if (!cache) { |
| 3542 | ret = -ENOMEM; |
| 3543 | break; |
| 3544 | } |
| 3545 | |
| 3546 | spin_lock_init(&cache->lock); |
| 3547 | read_extent_buffer(leaf, &cache->item, |
| 3548 | btrfs_item_ptr_offset(leaf, path->slots[0]), |
| 3549 | sizeof(cache->item)); |
| 3550 | memcpy(&cache->key, &found_key, sizeof(found_key)); |
| 3551 | |
| 3552 | key.objectid = found_key.objectid + found_key.offset; |
| 3553 | btrfs_release_path(root, path); |
| 3554 | cache->flags = btrfs_block_group_flags(&cache->item); |
| 3555 | bit = 0; |
| 3556 | if (cache->flags & BTRFS_BLOCK_GROUP_DATA) { |
| 3557 | bit = BLOCK_GROUP_DATA; |
| 3558 | } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { |
| 3559 | bit = BLOCK_GROUP_SYSTEM; |
| 3560 | } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) { |
| 3561 | bit = BLOCK_GROUP_METADATA; |
| 3562 | } |
| 3563 | set_avail_alloc_bits(info, cache->flags); |
| 3564 | |
| 3565 | ret = update_space_info(info, cache->flags, found_key.offset, |
| 3566 | btrfs_block_group_used(&cache->item), |
| 3567 | &space_info); |
| 3568 | BUG_ON(ret); |
| 3569 | cache->space_info = space_info; |
| 3570 | |
| 3571 | /* use EXTENT_LOCKED to prevent merging */ |
| 3572 | set_extent_bits(block_group_cache, found_key.objectid, |
| 3573 | found_key.objectid + found_key.offset - 1, |
| 3574 | EXTENT_LOCKED, GFP_NOFS); |
| 3575 | set_state_private(block_group_cache, found_key.objectid, |
| 3576 | (unsigned long)cache); |
| 3577 | set_extent_bits(block_group_cache, found_key.objectid, |
| 3578 | found_key.objectid + found_key.offset - 1, |
| 3579 | bit | EXTENT_LOCKED, GFP_NOFS); |
| 3580 | if (key.objectid >= |
| 3581 | btrfs_super_total_bytes(&info->super_copy)) |
| 3582 | break; |
| 3583 | } |
| 3584 | ret = 0; |
| 3585 | error: |
| 3586 | btrfs_free_path(path); |
| 3587 | mutex_unlock(&root->fs_info->alloc_mutex); |
| 3588 | return ret; |
| 3589 | } |
| 3590 | |
| 3591 | int btrfs_make_block_group(struct btrfs_trans_handle *trans, |
| 3592 | struct btrfs_root *root, u64 bytes_used, |
| 3593 | u64 type, u64 chunk_objectid, u64 chunk_offset, |
| 3594 | u64 size) |
| 3595 | { |
| 3596 | int ret; |
| 3597 | int bit = 0; |
| 3598 | struct btrfs_root *extent_root; |
| 3599 | struct btrfs_block_group_cache *cache; |
| 3600 | struct extent_io_tree *block_group_cache; |
| 3601 | |
| 3602 | WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); |
| 3603 | extent_root = root->fs_info->extent_root; |
| 3604 | block_group_cache = &root->fs_info->block_group_cache; |
| 3605 | |
| 3606 | cache = kzalloc(sizeof(*cache), GFP_NOFS); |
| 3607 | BUG_ON(!cache); |
| 3608 | cache->key.objectid = chunk_offset; |
| 3609 | cache->key.offset = size; |
| 3610 | spin_lock_init(&cache->lock); |
| 3611 | btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY); |
| 3612 | |
| 3613 | btrfs_set_block_group_used(&cache->item, bytes_used); |
| 3614 | btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); |
| 3615 | cache->flags = type; |
| 3616 | btrfs_set_block_group_flags(&cache->item, type); |
| 3617 | |
| 3618 | ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, |
| 3619 | &cache->space_info); |
| 3620 | BUG_ON(ret); |
| 3621 | |
| 3622 | bit = block_group_state_bits(type); |
| 3623 | set_extent_bits(block_group_cache, chunk_offset, |
| 3624 | chunk_offset + size - 1, |
| 3625 | EXTENT_LOCKED, GFP_NOFS); |
| 3626 | set_state_private(block_group_cache, chunk_offset, |
| 3627 | (unsigned long)cache); |
| 3628 | set_extent_bits(block_group_cache, chunk_offset, |
| 3629 | chunk_offset + size - 1, |
| 3630 | bit | EXTENT_LOCKED, GFP_NOFS); |
| 3631 | |
| 3632 | ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, |
| 3633 | sizeof(cache->item)); |
| 3634 | BUG_ON(ret); |
| 3635 | |
| 3636 | finish_current_insert(trans, extent_root); |
| 3637 | ret = del_pending_extents(trans, extent_root); |
| 3638 | BUG_ON(ret); |
| 3639 | set_avail_alloc_bits(extent_root->fs_info, type); |
| 3640 | |
| 3641 | return 0; |
| 3642 | } |