| 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 | |
| 19 | #include <linux/fs.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/writeback.h> |
| 23 | #include <linux/pagemap.h> |
| 24 | #include <linux/blkdev.h> |
| 25 | #include "ctree.h" |
| 26 | #include "disk-io.h" |
| 27 | #include "transaction.h" |
| 28 | #include "locking.h" |
| 29 | #include "tree-log.h" |
| 30 | |
| 31 | #define BTRFS_ROOT_TRANS_TAG 0 |
| 32 | |
| 33 | static noinline void put_transaction(struct btrfs_transaction *transaction) |
| 34 | { |
| 35 | WARN_ON(transaction->use_count == 0); |
| 36 | transaction->use_count--; |
| 37 | if (transaction->use_count == 0) { |
| 38 | list_del_init(&transaction->list); |
| 39 | memset(transaction, 0, sizeof(*transaction)); |
| 40 | kmem_cache_free(btrfs_transaction_cachep, transaction); |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | static noinline void switch_commit_root(struct btrfs_root *root) |
| 45 | { |
| 46 | free_extent_buffer(root->commit_root); |
| 47 | root->commit_root = btrfs_root_node(root); |
| 48 | } |
| 49 | |
| 50 | /* |
| 51 | * either allocate a new transaction or hop into the existing one |
| 52 | */ |
| 53 | static noinline int join_transaction(struct btrfs_root *root) |
| 54 | { |
| 55 | struct btrfs_transaction *cur_trans; |
| 56 | cur_trans = root->fs_info->running_transaction; |
| 57 | if (!cur_trans) { |
| 58 | cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, |
| 59 | GFP_NOFS); |
| 60 | BUG_ON(!cur_trans); |
| 61 | root->fs_info->generation++; |
| 62 | cur_trans->num_writers = 1; |
| 63 | cur_trans->num_joined = 0; |
| 64 | cur_trans->transid = root->fs_info->generation; |
| 65 | init_waitqueue_head(&cur_trans->writer_wait); |
| 66 | init_waitqueue_head(&cur_trans->commit_wait); |
| 67 | cur_trans->in_commit = 0; |
| 68 | cur_trans->blocked = 0; |
| 69 | cur_trans->use_count = 1; |
| 70 | cur_trans->commit_done = 0; |
| 71 | cur_trans->start_time = get_seconds(); |
| 72 | |
| 73 | cur_trans->delayed_refs.root = RB_ROOT; |
| 74 | cur_trans->delayed_refs.num_entries = 0; |
| 75 | cur_trans->delayed_refs.num_heads_ready = 0; |
| 76 | cur_trans->delayed_refs.num_heads = 0; |
| 77 | cur_trans->delayed_refs.flushing = 0; |
| 78 | cur_trans->delayed_refs.run_delayed_start = 0; |
| 79 | spin_lock_init(&cur_trans->delayed_refs.lock); |
| 80 | |
| 81 | INIT_LIST_HEAD(&cur_trans->pending_snapshots); |
| 82 | list_add_tail(&cur_trans->list, &root->fs_info->trans_list); |
| 83 | extent_io_tree_init(&cur_trans->dirty_pages, |
| 84 | root->fs_info->btree_inode->i_mapping, |
| 85 | GFP_NOFS); |
| 86 | spin_lock(&root->fs_info->new_trans_lock); |
| 87 | root->fs_info->running_transaction = cur_trans; |
| 88 | spin_unlock(&root->fs_info->new_trans_lock); |
| 89 | } else { |
| 90 | cur_trans->num_writers++; |
| 91 | cur_trans->num_joined++; |
| 92 | } |
| 93 | |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * this does all the record keeping required to make sure that a reference |
| 99 | * counted root is properly recorded in a given transaction. This is required |
| 100 | * to make sure the old root from before we joined the transaction is deleted |
| 101 | * when the transaction commits |
| 102 | */ |
| 103 | static noinline int record_root_in_trans(struct btrfs_trans_handle *trans, |
| 104 | struct btrfs_root *root) |
| 105 | { |
| 106 | if (root->ref_cows && root->last_trans < trans->transid) { |
| 107 | WARN_ON(root == root->fs_info->extent_root); |
| 108 | WARN_ON(root->commit_root != root->node); |
| 109 | |
| 110 | radix_tree_tag_set(&root->fs_info->fs_roots_radix, |
| 111 | (unsigned long)root->root_key.objectid, |
| 112 | BTRFS_ROOT_TRANS_TAG); |
| 113 | root->last_trans = trans->transid; |
| 114 | btrfs_init_reloc_root(trans, root); |
| 115 | } |
| 116 | return 0; |
| 117 | } |
| 118 | |
| 119 | int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, |
| 120 | struct btrfs_root *root) |
| 121 | { |
| 122 | if (!root->ref_cows) |
| 123 | return 0; |
| 124 | |
| 125 | mutex_lock(&root->fs_info->trans_mutex); |
| 126 | if (root->last_trans == trans->transid) { |
| 127 | mutex_unlock(&root->fs_info->trans_mutex); |
| 128 | return 0; |
| 129 | } |
| 130 | |
| 131 | record_root_in_trans(trans, root); |
| 132 | mutex_unlock(&root->fs_info->trans_mutex); |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | /* wait for commit against the current transaction to become unblocked |
| 137 | * when this is done, it is safe to start a new transaction, but the current |
| 138 | * transaction might not be fully on disk. |
| 139 | */ |
| 140 | static void wait_current_trans(struct btrfs_root *root) |
| 141 | { |
| 142 | struct btrfs_transaction *cur_trans; |
| 143 | |
| 144 | cur_trans = root->fs_info->running_transaction; |
| 145 | if (cur_trans && cur_trans->blocked) { |
| 146 | DEFINE_WAIT(wait); |
| 147 | cur_trans->use_count++; |
| 148 | while (1) { |
| 149 | prepare_to_wait(&root->fs_info->transaction_wait, &wait, |
| 150 | TASK_UNINTERRUPTIBLE); |
| 151 | if (!cur_trans->blocked) |
| 152 | break; |
| 153 | mutex_unlock(&root->fs_info->trans_mutex); |
| 154 | schedule(); |
| 155 | mutex_lock(&root->fs_info->trans_mutex); |
| 156 | } |
| 157 | finish_wait(&root->fs_info->transaction_wait, &wait); |
| 158 | put_transaction(cur_trans); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | enum btrfs_trans_type { |
| 163 | TRANS_START, |
| 164 | TRANS_JOIN, |
| 165 | TRANS_USERSPACE, |
| 166 | }; |
| 167 | |
| 168 | static int may_wait_transaction(struct btrfs_root *root, int type) |
| 169 | { |
| 170 | if (!root->fs_info->log_root_recovering && |
| 171 | ((type == TRANS_START && !root->fs_info->open_ioctl_trans) || |
| 172 | type == TRANS_USERSPACE)) |
| 173 | return 1; |
| 174 | return 0; |
| 175 | } |
| 176 | |
| 177 | static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root, |
| 178 | u64 num_items, int type) |
| 179 | { |
| 180 | struct btrfs_trans_handle *h; |
| 181 | struct btrfs_transaction *cur_trans; |
| 182 | int retries = 0; |
| 183 | int ret; |
| 184 | again: |
| 185 | h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); |
| 186 | if (!h) |
| 187 | return ERR_PTR(-ENOMEM); |
| 188 | |
| 189 | mutex_lock(&root->fs_info->trans_mutex); |
| 190 | if (may_wait_transaction(root, type)) |
| 191 | wait_current_trans(root); |
| 192 | |
| 193 | ret = join_transaction(root); |
| 194 | BUG_ON(ret); |
| 195 | |
| 196 | cur_trans = root->fs_info->running_transaction; |
| 197 | cur_trans->use_count++; |
| 198 | mutex_unlock(&root->fs_info->trans_mutex); |
| 199 | |
| 200 | h->transid = cur_trans->transid; |
| 201 | h->transaction = cur_trans; |
| 202 | h->blocks_used = 0; |
| 203 | h->block_group = 0; |
| 204 | h->bytes_reserved = 0; |
| 205 | h->delayed_ref_updates = 0; |
| 206 | h->block_rsv = NULL; |
| 207 | |
| 208 | smp_mb(); |
| 209 | if (cur_trans->blocked && may_wait_transaction(root, type)) { |
| 210 | btrfs_commit_transaction(h, root); |
| 211 | goto again; |
| 212 | } |
| 213 | |
| 214 | if (num_items > 0) { |
| 215 | ret = btrfs_trans_reserve_metadata(h, root, num_items, |
| 216 | &retries); |
| 217 | if (ret == -EAGAIN) { |
| 218 | btrfs_commit_transaction(h, root); |
| 219 | goto again; |
| 220 | } |
| 221 | if (ret < 0) { |
| 222 | btrfs_end_transaction(h, root); |
| 223 | return ERR_PTR(ret); |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | mutex_lock(&root->fs_info->trans_mutex); |
| 228 | record_root_in_trans(h, root); |
| 229 | mutex_unlock(&root->fs_info->trans_mutex); |
| 230 | |
| 231 | if (!current->journal_info && type != TRANS_USERSPACE) |
| 232 | current->journal_info = h; |
| 233 | return h; |
| 234 | } |
| 235 | |
| 236 | struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, |
| 237 | int num_items) |
| 238 | { |
| 239 | return start_transaction(root, num_items, TRANS_START); |
| 240 | } |
| 241 | struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root, |
| 242 | int num_blocks) |
| 243 | { |
| 244 | return start_transaction(root, 0, TRANS_JOIN); |
| 245 | } |
| 246 | |
| 247 | struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r, |
| 248 | int num_blocks) |
| 249 | { |
| 250 | return start_transaction(r, 0, TRANS_USERSPACE); |
| 251 | } |
| 252 | |
| 253 | /* wait for a transaction commit to be fully complete */ |
| 254 | static noinline int wait_for_commit(struct btrfs_root *root, |
| 255 | struct btrfs_transaction *commit) |
| 256 | { |
| 257 | DEFINE_WAIT(wait); |
| 258 | mutex_lock(&root->fs_info->trans_mutex); |
| 259 | while (!commit->commit_done) { |
| 260 | prepare_to_wait(&commit->commit_wait, &wait, |
| 261 | TASK_UNINTERRUPTIBLE); |
| 262 | if (commit->commit_done) |
| 263 | break; |
| 264 | mutex_unlock(&root->fs_info->trans_mutex); |
| 265 | schedule(); |
| 266 | mutex_lock(&root->fs_info->trans_mutex); |
| 267 | } |
| 268 | mutex_unlock(&root->fs_info->trans_mutex); |
| 269 | finish_wait(&commit->commit_wait, &wait); |
| 270 | return 0; |
| 271 | } |
| 272 | |
| 273 | #if 0 |
| 274 | /* |
| 275 | * rate limit against the drop_snapshot code. This helps to slow down new |
| 276 | * operations if the drop_snapshot code isn't able to keep up. |
| 277 | */ |
| 278 | static void throttle_on_drops(struct btrfs_root *root) |
| 279 | { |
| 280 | struct btrfs_fs_info *info = root->fs_info; |
| 281 | int harder_count = 0; |
| 282 | |
| 283 | harder: |
| 284 | if (atomic_read(&info->throttles)) { |
| 285 | DEFINE_WAIT(wait); |
| 286 | int thr; |
| 287 | thr = atomic_read(&info->throttle_gen); |
| 288 | |
| 289 | do { |
| 290 | prepare_to_wait(&info->transaction_throttle, |
| 291 | &wait, TASK_UNINTERRUPTIBLE); |
| 292 | if (!atomic_read(&info->throttles)) { |
| 293 | finish_wait(&info->transaction_throttle, &wait); |
| 294 | break; |
| 295 | } |
| 296 | schedule(); |
| 297 | finish_wait(&info->transaction_throttle, &wait); |
| 298 | } while (thr == atomic_read(&info->throttle_gen)); |
| 299 | harder_count++; |
| 300 | |
| 301 | if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 && |
| 302 | harder_count < 2) |
| 303 | goto harder; |
| 304 | |
| 305 | if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 && |
| 306 | harder_count < 10) |
| 307 | goto harder; |
| 308 | |
| 309 | if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 && |
| 310 | harder_count < 20) |
| 311 | goto harder; |
| 312 | } |
| 313 | } |
| 314 | #endif |
| 315 | |
| 316 | void btrfs_throttle(struct btrfs_root *root) |
| 317 | { |
| 318 | mutex_lock(&root->fs_info->trans_mutex); |
| 319 | if (!root->fs_info->open_ioctl_trans) |
| 320 | wait_current_trans(root); |
| 321 | mutex_unlock(&root->fs_info->trans_mutex); |
| 322 | } |
| 323 | |
| 324 | static int should_end_transaction(struct btrfs_trans_handle *trans, |
| 325 | struct btrfs_root *root) |
| 326 | { |
| 327 | int ret; |
| 328 | ret = btrfs_block_rsv_check(trans, root, |
| 329 | &root->fs_info->global_block_rsv, 0, 5); |
| 330 | return ret ? 1 : 0; |
| 331 | } |
| 332 | |
| 333 | int btrfs_should_end_transaction(struct btrfs_trans_handle *trans, |
| 334 | struct btrfs_root *root) |
| 335 | { |
| 336 | struct btrfs_transaction *cur_trans = trans->transaction; |
| 337 | int updates; |
| 338 | |
| 339 | if (cur_trans->blocked || cur_trans->delayed_refs.flushing) |
| 340 | return 1; |
| 341 | |
| 342 | updates = trans->delayed_ref_updates; |
| 343 | trans->delayed_ref_updates = 0; |
| 344 | if (updates) |
| 345 | btrfs_run_delayed_refs(trans, root, updates); |
| 346 | |
| 347 | return should_end_transaction(trans, root); |
| 348 | } |
| 349 | |
| 350 | static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, |
| 351 | struct btrfs_root *root, int throttle) |
| 352 | { |
| 353 | struct btrfs_transaction *cur_trans = trans->transaction; |
| 354 | struct btrfs_fs_info *info = root->fs_info; |
| 355 | int count = 0; |
| 356 | |
| 357 | while (count < 4) { |
| 358 | unsigned long cur = trans->delayed_ref_updates; |
| 359 | trans->delayed_ref_updates = 0; |
| 360 | if (cur && |
| 361 | trans->transaction->delayed_refs.num_heads_ready > 64) { |
| 362 | trans->delayed_ref_updates = 0; |
| 363 | |
| 364 | /* |
| 365 | * do a full flush if the transaction is trying |
| 366 | * to close |
| 367 | */ |
| 368 | if (trans->transaction->delayed_refs.flushing) |
| 369 | cur = 0; |
| 370 | btrfs_run_delayed_refs(trans, root, cur); |
| 371 | } else { |
| 372 | break; |
| 373 | } |
| 374 | count++; |
| 375 | } |
| 376 | |
| 377 | btrfs_trans_release_metadata(trans, root); |
| 378 | |
| 379 | if (!root->fs_info->open_ioctl_trans && |
| 380 | should_end_transaction(trans, root)) |
| 381 | trans->transaction->blocked = 1; |
| 382 | |
| 383 | if (cur_trans->blocked && !cur_trans->in_commit) { |
| 384 | if (throttle) |
| 385 | return btrfs_commit_transaction(trans, root); |
| 386 | else |
| 387 | wake_up_process(info->transaction_kthread); |
| 388 | } |
| 389 | |
| 390 | mutex_lock(&info->trans_mutex); |
| 391 | WARN_ON(cur_trans != info->running_transaction); |
| 392 | WARN_ON(cur_trans->num_writers < 1); |
| 393 | cur_trans->num_writers--; |
| 394 | |
| 395 | if (waitqueue_active(&cur_trans->writer_wait)) |
| 396 | wake_up(&cur_trans->writer_wait); |
| 397 | put_transaction(cur_trans); |
| 398 | mutex_unlock(&info->trans_mutex); |
| 399 | |
| 400 | if (current->journal_info == trans) |
| 401 | current->journal_info = NULL; |
| 402 | memset(trans, 0, sizeof(*trans)); |
| 403 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| 404 | |
| 405 | if (throttle) |
| 406 | btrfs_run_delayed_iputs(root); |
| 407 | |
| 408 | return 0; |
| 409 | } |
| 410 | |
| 411 | int btrfs_end_transaction(struct btrfs_trans_handle *trans, |
| 412 | struct btrfs_root *root) |
| 413 | { |
| 414 | return __btrfs_end_transaction(trans, root, 0); |
| 415 | } |
| 416 | |
| 417 | int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans, |
| 418 | struct btrfs_root *root) |
| 419 | { |
| 420 | return __btrfs_end_transaction(trans, root, 1); |
| 421 | } |
| 422 | |
| 423 | /* |
| 424 | * when btree blocks are allocated, they have some corresponding bits set for |
| 425 | * them in one of two extent_io trees. This is used to make sure all of |
| 426 | * those extents are sent to disk but does not wait on them |
| 427 | */ |
| 428 | int btrfs_write_marked_extents(struct btrfs_root *root, |
| 429 | struct extent_io_tree *dirty_pages, int mark) |
| 430 | { |
| 431 | int ret; |
| 432 | int err = 0; |
| 433 | int werr = 0; |
| 434 | struct page *page; |
| 435 | struct inode *btree_inode = root->fs_info->btree_inode; |
| 436 | u64 start = 0; |
| 437 | u64 end; |
| 438 | unsigned long index; |
| 439 | |
| 440 | while (1) { |
| 441 | ret = find_first_extent_bit(dirty_pages, start, &start, &end, |
| 442 | mark); |
| 443 | if (ret) |
| 444 | break; |
| 445 | while (start <= end) { |
| 446 | cond_resched(); |
| 447 | |
| 448 | index = start >> PAGE_CACHE_SHIFT; |
| 449 | start = (u64)(index + 1) << PAGE_CACHE_SHIFT; |
| 450 | page = find_get_page(btree_inode->i_mapping, index); |
| 451 | if (!page) |
| 452 | continue; |
| 453 | |
| 454 | btree_lock_page_hook(page); |
| 455 | if (!page->mapping) { |
| 456 | unlock_page(page); |
| 457 | page_cache_release(page); |
| 458 | continue; |
| 459 | } |
| 460 | |
| 461 | if (PageWriteback(page)) { |
| 462 | if (PageDirty(page)) |
| 463 | wait_on_page_writeback(page); |
| 464 | else { |
| 465 | unlock_page(page); |
| 466 | page_cache_release(page); |
| 467 | continue; |
| 468 | } |
| 469 | } |
| 470 | err = write_one_page(page, 0); |
| 471 | if (err) |
| 472 | werr = err; |
| 473 | page_cache_release(page); |
| 474 | } |
| 475 | } |
| 476 | if (err) |
| 477 | werr = err; |
| 478 | return werr; |
| 479 | } |
| 480 | |
| 481 | /* |
| 482 | * when btree blocks are allocated, they have some corresponding bits set for |
| 483 | * them in one of two extent_io trees. This is used to make sure all of |
| 484 | * those extents are on disk for transaction or log commit. We wait |
| 485 | * on all the pages and clear them from the dirty pages state tree |
| 486 | */ |
| 487 | int btrfs_wait_marked_extents(struct btrfs_root *root, |
| 488 | struct extent_io_tree *dirty_pages, int mark) |
| 489 | { |
| 490 | int ret; |
| 491 | int err = 0; |
| 492 | int werr = 0; |
| 493 | struct page *page; |
| 494 | struct inode *btree_inode = root->fs_info->btree_inode; |
| 495 | u64 start = 0; |
| 496 | u64 end; |
| 497 | unsigned long index; |
| 498 | |
| 499 | while (1) { |
| 500 | ret = find_first_extent_bit(dirty_pages, start, &start, &end, |
| 501 | mark); |
| 502 | if (ret) |
| 503 | break; |
| 504 | |
| 505 | clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS); |
| 506 | while (start <= end) { |
| 507 | index = start >> PAGE_CACHE_SHIFT; |
| 508 | start = (u64)(index + 1) << PAGE_CACHE_SHIFT; |
| 509 | page = find_get_page(btree_inode->i_mapping, index); |
| 510 | if (!page) |
| 511 | continue; |
| 512 | if (PageDirty(page)) { |
| 513 | btree_lock_page_hook(page); |
| 514 | wait_on_page_writeback(page); |
| 515 | err = write_one_page(page, 0); |
| 516 | if (err) |
| 517 | werr = err; |
| 518 | } |
| 519 | wait_on_page_writeback(page); |
| 520 | page_cache_release(page); |
| 521 | cond_resched(); |
| 522 | } |
| 523 | } |
| 524 | if (err) |
| 525 | werr = err; |
| 526 | return werr; |
| 527 | } |
| 528 | |
| 529 | /* |
| 530 | * when btree blocks are allocated, they have some corresponding bits set for |
| 531 | * them in one of two extent_io trees. This is used to make sure all of |
| 532 | * those extents are on disk for transaction or log commit |
| 533 | */ |
| 534 | int btrfs_write_and_wait_marked_extents(struct btrfs_root *root, |
| 535 | struct extent_io_tree *dirty_pages, int mark) |
| 536 | { |
| 537 | int ret; |
| 538 | int ret2; |
| 539 | |
| 540 | ret = btrfs_write_marked_extents(root, dirty_pages, mark); |
| 541 | ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark); |
| 542 | return ret || ret2; |
| 543 | } |
| 544 | |
| 545 | int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, |
| 546 | struct btrfs_root *root) |
| 547 | { |
| 548 | if (!trans || !trans->transaction) { |
| 549 | struct inode *btree_inode; |
| 550 | btree_inode = root->fs_info->btree_inode; |
| 551 | return filemap_write_and_wait(btree_inode->i_mapping); |
| 552 | } |
| 553 | return btrfs_write_and_wait_marked_extents(root, |
| 554 | &trans->transaction->dirty_pages, |
| 555 | EXTENT_DIRTY); |
| 556 | } |
| 557 | |
| 558 | /* |
| 559 | * this is used to update the root pointer in the tree of tree roots. |
| 560 | * |
| 561 | * But, in the case of the extent allocation tree, updating the root |
| 562 | * pointer may allocate blocks which may change the root of the extent |
| 563 | * allocation tree. |
| 564 | * |
| 565 | * So, this loops and repeats and makes sure the cowonly root didn't |
| 566 | * change while the root pointer was being updated in the metadata. |
| 567 | */ |
| 568 | static int update_cowonly_root(struct btrfs_trans_handle *trans, |
| 569 | struct btrfs_root *root) |
| 570 | { |
| 571 | int ret; |
| 572 | u64 old_root_bytenr; |
| 573 | u64 old_root_used; |
| 574 | struct btrfs_root *tree_root = root->fs_info->tree_root; |
| 575 | |
| 576 | old_root_used = btrfs_root_used(&root->root_item); |
| 577 | btrfs_write_dirty_block_groups(trans, root); |
| 578 | |
| 579 | while (1) { |
| 580 | old_root_bytenr = btrfs_root_bytenr(&root->root_item); |
| 581 | if (old_root_bytenr == root->node->start && |
| 582 | old_root_used == btrfs_root_used(&root->root_item)) |
| 583 | break; |
| 584 | |
| 585 | btrfs_set_root_node(&root->root_item, root->node); |
| 586 | ret = btrfs_update_root(trans, tree_root, |
| 587 | &root->root_key, |
| 588 | &root->root_item); |
| 589 | BUG_ON(ret); |
| 590 | |
| 591 | old_root_used = btrfs_root_used(&root->root_item); |
| 592 | ret = btrfs_write_dirty_block_groups(trans, root); |
| 593 | BUG_ON(ret); |
| 594 | } |
| 595 | |
| 596 | if (root != root->fs_info->extent_root) |
| 597 | switch_commit_root(root); |
| 598 | |
| 599 | return 0; |
| 600 | } |
| 601 | |
| 602 | /* |
| 603 | * update all the cowonly tree roots on disk |
| 604 | */ |
| 605 | static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans, |
| 606 | struct btrfs_root *root) |
| 607 | { |
| 608 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 609 | struct list_head *next; |
| 610 | struct extent_buffer *eb; |
| 611 | int ret; |
| 612 | |
| 613 | ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); |
| 614 | BUG_ON(ret); |
| 615 | |
| 616 | eb = btrfs_lock_root_node(fs_info->tree_root); |
| 617 | btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb); |
| 618 | btrfs_tree_unlock(eb); |
| 619 | free_extent_buffer(eb); |
| 620 | |
| 621 | ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); |
| 622 | BUG_ON(ret); |
| 623 | |
| 624 | while (!list_empty(&fs_info->dirty_cowonly_roots)) { |
| 625 | next = fs_info->dirty_cowonly_roots.next; |
| 626 | list_del_init(next); |
| 627 | root = list_entry(next, struct btrfs_root, dirty_list); |
| 628 | |
| 629 | update_cowonly_root(trans, root); |
| 630 | } |
| 631 | |
| 632 | down_write(&fs_info->extent_commit_sem); |
| 633 | switch_commit_root(fs_info->extent_root); |
| 634 | up_write(&fs_info->extent_commit_sem); |
| 635 | |
| 636 | return 0; |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * dead roots are old snapshots that need to be deleted. This allocates |
| 641 | * a dirty root struct and adds it into the list of dead roots that need to |
| 642 | * be deleted |
| 643 | */ |
| 644 | int btrfs_add_dead_root(struct btrfs_root *root) |
| 645 | { |
| 646 | mutex_lock(&root->fs_info->trans_mutex); |
| 647 | list_add(&root->root_list, &root->fs_info->dead_roots); |
| 648 | mutex_unlock(&root->fs_info->trans_mutex); |
| 649 | return 0; |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | * update all the cowonly tree roots on disk |
| 654 | */ |
| 655 | static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, |
| 656 | struct btrfs_root *root) |
| 657 | { |
| 658 | struct btrfs_root *gang[8]; |
| 659 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 660 | int i; |
| 661 | int ret; |
| 662 | int err = 0; |
| 663 | |
| 664 | while (1) { |
| 665 | ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix, |
| 666 | (void **)gang, 0, |
| 667 | ARRAY_SIZE(gang), |
| 668 | BTRFS_ROOT_TRANS_TAG); |
| 669 | if (ret == 0) |
| 670 | break; |
| 671 | for (i = 0; i < ret; i++) { |
| 672 | root = gang[i]; |
| 673 | radix_tree_tag_clear(&fs_info->fs_roots_radix, |
| 674 | (unsigned long)root->root_key.objectid, |
| 675 | BTRFS_ROOT_TRANS_TAG); |
| 676 | |
| 677 | btrfs_free_log(trans, root); |
| 678 | btrfs_update_reloc_root(trans, root); |
| 679 | btrfs_orphan_commit_root(trans, root); |
| 680 | |
| 681 | if (root->commit_root != root->node) { |
| 682 | switch_commit_root(root); |
| 683 | btrfs_set_root_node(&root->root_item, |
| 684 | root->node); |
| 685 | } |
| 686 | |
| 687 | err = btrfs_update_root(trans, fs_info->tree_root, |
| 688 | &root->root_key, |
| 689 | &root->root_item); |
| 690 | if (err) |
| 691 | break; |
| 692 | } |
| 693 | } |
| 694 | return err; |
| 695 | } |
| 696 | |
| 697 | /* |
| 698 | * defrag a given btree. If cacheonly == 1, this won't read from the disk, |
| 699 | * otherwise every leaf in the btree is read and defragged. |
| 700 | */ |
| 701 | int btrfs_defrag_root(struct btrfs_root *root, int cacheonly) |
| 702 | { |
| 703 | struct btrfs_fs_info *info = root->fs_info; |
| 704 | struct btrfs_trans_handle *trans; |
| 705 | int ret; |
| 706 | unsigned long nr; |
| 707 | |
| 708 | if (xchg(&root->defrag_running, 1)) |
| 709 | return 0; |
| 710 | |
| 711 | while (1) { |
| 712 | trans = btrfs_start_transaction(root, 0); |
| 713 | if (IS_ERR(trans)) |
| 714 | return PTR_ERR(trans); |
| 715 | |
| 716 | ret = btrfs_defrag_leaves(trans, root, cacheonly); |
| 717 | |
| 718 | nr = trans->blocks_used; |
| 719 | btrfs_end_transaction(trans, root); |
| 720 | btrfs_btree_balance_dirty(info->tree_root, nr); |
| 721 | cond_resched(); |
| 722 | |
| 723 | if (root->fs_info->closing || ret != -EAGAIN) |
| 724 | break; |
| 725 | } |
| 726 | root->defrag_running = 0; |
| 727 | return ret; |
| 728 | } |
| 729 | |
| 730 | #if 0 |
| 731 | /* |
| 732 | * when dropping snapshots, we generate a ton of delayed refs, and it makes |
| 733 | * sense not to join the transaction while it is trying to flush the current |
| 734 | * queue of delayed refs out. |
| 735 | * |
| 736 | * This is used by the drop snapshot code only |
| 737 | */ |
| 738 | static noinline int wait_transaction_pre_flush(struct btrfs_fs_info *info) |
| 739 | { |
| 740 | DEFINE_WAIT(wait); |
| 741 | |
| 742 | mutex_lock(&info->trans_mutex); |
| 743 | while (info->running_transaction && |
| 744 | info->running_transaction->delayed_refs.flushing) { |
| 745 | prepare_to_wait(&info->transaction_wait, &wait, |
| 746 | TASK_UNINTERRUPTIBLE); |
| 747 | mutex_unlock(&info->trans_mutex); |
| 748 | |
| 749 | schedule(); |
| 750 | |
| 751 | mutex_lock(&info->trans_mutex); |
| 752 | finish_wait(&info->transaction_wait, &wait); |
| 753 | } |
| 754 | mutex_unlock(&info->trans_mutex); |
| 755 | return 0; |
| 756 | } |
| 757 | |
| 758 | /* |
| 759 | * Given a list of roots that need to be deleted, call btrfs_drop_snapshot on |
| 760 | * all of them |
| 761 | */ |
| 762 | int btrfs_drop_dead_root(struct btrfs_root *root) |
| 763 | { |
| 764 | struct btrfs_trans_handle *trans; |
| 765 | struct btrfs_root *tree_root = root->fs_info->tree_root; |
| 766 | unsigned long nr; |
| 767 | int ret; |
| 768 | |
| 769 | while (1) { |
| 770 | /* |
| 771 | * we don't want to jump in and create a bunch of |
| 772 | * delayed refs if the transaction is starting to close |
| 773 | */ |
| 774 | wait_transaction_pre_flush(tree_root->fs_info); |
| 775 | trans = btrfs_start_transaction(tree_root, 1); |
| 776 | |
| 777 | /* |
| 778 | * we've joined a transaction, make sure it isn't |
| 779 | * closing right now |
| 780 | */ |
| 781 | if (trans->transaction->delayed_refs.flushing) { |
| 782 | btrfs_end_transaction(trans, tree_root); |
| 783 | continue; |
| 784 | } |
| 785 | |
| 786 | ret = btrfs_drop_snapshot(trans, root); |
| 787 | if (ret != -EAGAIN) |
| 788 | break; |
| 789 | |
| 790 | ret = btrfs_update_root(trans, tree_root, |
| 791 | &root->root_key, |
| 792 | &root->root_item); |
| 793 | if (ret) |
| 794 | break; |
| 795 | |
| 796 | nr = trans->blocks_used; |
| 797 | ret = btrfs_end_transaction(trans, tree_root); |
| 798 | BUG_ON(ret); |
| 799 | |
| 800 | btrfs_btree_balance_dirty(tree_root, nr); |
| 801 | cond_resched(); |
| 802 | } |
| 803 | BUG_ON(ret); |
| 804 | |
| 805 | ret = btrfs_del_root(trans, tree_root, &root->root_key); |
| 806 | BUG_ON(ret); |
| 807 | |
| 808 | nr = trans->blocks_used; |
| 809 | ret = btrfs_end_transaction(trans, tree_root); |
| 810 | BUG_ON(ret); |
| 811 | |
| 812 | free_extent_buffer(root->node); |
| 813 | free_extent_buffer(root->commit_root); |
| 814 | kfree(root); |
| 815 | |
| 816 | btrfs_btree_balance_dirty(tree_root, nr); |
| 817 | return ret; |
| 818 | } |
| 819 | #endif |
| 820 | |
| 821 | /* |
| 822 | * new snapshots need to be created at a very specific time in the |
| 823 | * transaction commit. This does the actual creation |
| 824 | */ |
| 825 | static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, |
| 826 | struct btrfs_fs_info *fs_info, |
| 827 | struct btrfs_pending_snapshot *pending) |
| 828 | { |
| 829 | struct btrfs_key key; |
| 830 | struct btrfs_root_item *new_root_item; |
| 831 | struct btrfs_root *tree_root = fs_info->tree_root; |
| 832 | struct btrfs_root *root = pending->root; |
| 833 | struct btrfs_root *parent_root; |
| 834 | struct inode *parent_inode; |
| 835 | struct dentry *dentry; |
| 836 | struct extent_buffer *tmp; |
| 837 | struct extent_buffer *old; |
| 838 | int ret; |
| 839 | int retries = 0; |
| 840 | u64 to_reserve = 0; |
| 841 | u64 index = 0; |
| 842 | u64 objectid; |
| 843 | |
| 844 | new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS); |
| 845 | if (!new_root_item) { |
| 846 | pending->error = -ENOMEM; |
| 847 | goto fail; |
| 848 | } |
| 849 | |
| 850 | ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid); |
| 851 | if (ret) { |
| 852 | pending->error = ret; |
| 853 | goto fail; |
| 854 | } |
| 855 | |
| 856 | btrfs_reloc_pre_snapshot(trans, pending, &to_reserve); |
| 857 | btrfs_orphan_pre_snapshot(trans, pending, &to_reserve); |
| 858 | |
| 859 | if (to_reserve > 0) { |
| 860 | ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv, |
| 861 | to_reserve, &retries); |
| 862 | if (ret) { |
| 863 | pending->error = ret; |
| 864 | goto fail; |
| 865 | } |
| 866 | } |
| 867 | |
| 868 | key.objectid = objectid; |
| 869 | key.offset = (u64)-1; |
| 870 | key.type = BTRFS_ROOT_ITEM_KEY; |
| 871 | |
| 872 | trans->block_rsv = &pending->block_rsv; |
| 873 | |
| 874 | dentry = pending->dentry; |
| 875 | parent_inode = dentry->d_parent->d_inode; |
| 876 | parent_root = BTRFS_I(parent_inode)->root; |
| 877 | record_root_in_trans(trans, parent_root); |
| 878 | |
| 879 | /* |
| 880 | * insert the directory item |
| 881 | */ |
| 882 | ret = btrfs_set_inode_index(parent_inode, &index); |
| 883 | BUG_ON(ret); |
| 884 | ret = btrfs_insert_dir_item(trans, parent_root, |
| 885 | dentry->d_name.name, dentry->d_name.len, |
| 886 | parent_inode->i_ino, &key, |
| 887 | BTRFS_FT_DIR, index); |
| 888 | BUG_ON(ret); |
| 889 | |
| 890 | btrfs_i_size_write(parent_inode, parent_inode->i_size + |
| 891 | dentry->d_name.len * 2); |
| 892 | ret = btrfs_update_inode(trans, parent_root, parent_inode); |
| 893 | BUG_ON(ret); |
| 894 | |
| 895 | record_root_in_trans(trans, root); |
| 896 | btrfs_set_root_last_snapshot(&root->root_item, trans->transid); |
| 897 | memcpy(new_root_item, &root->root_item, sizeof(*new_root_item)); |
| 898 | |
| 899 | old = btrfs_lock_root_node(root); |
| 900 | btrfs_cow_block(trans, root, old, NULL, 0, &old); |
| 901 | btrfs_set_lock_blocking(old); |
| 902 | |
| 903 | btrfs_copy_root(trans, root, old, &tmp, objectid); |
| 904 | btrfs_tree_unlock(old); |
| 905 | free_extent_buffer(old); |
| 906 | |
| 907 | btrfs_set_root_node(new_root_item, tmp); |
| 908 | /* record when the snapshot was created in key.offset */ |
| 909 | key.offset = trans->transid; |
| 910 | ret = btrfs_insert_root(trans, tree_root, &key, new_root_item); |
| 911 | btrfs_tree_unlock(tmp); |
| 912 | free_extent_buffer(tmp); |
| 913 | BUG_ON(ret); |
| 914 | |
| 915 | /* |
| 916 | * insert root back/forward references |
| 917 | */ |
| 918 | ret = btrfs_add_root_ref(trans, tree_root, objectid, |
| 919 | parent_root->root_key.objectid, |
| 920 | parent_inode->i_ino, index, |
| 921 | dentry->d_name.name, dentry->d_name.len); |
| 922 | BUG_ON(ret); |
| 923 | |
| 924 | key.offset = (u64)-1; |
| 925 | pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key); |
| 926 | BUG_ON(IS_ERR(pending->snap)); |
| 927 | |
| 928 | btrfs_reloc_post_snapshot(trans, pending); |
| 929 | btrfs_orphan_post_snapshot(trans, pending); |
| 930 | fail: |
| 931 | kfree(new_root_item); |
| 932 | btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1); |
| 933 | return 0; |
| 934 | } |
| 935 | |
| 936 | /* |
| 937 | * create all the snapshots we've scheduled for creation |
| 938 | */ |
| 939 | static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans, |
| 940 | struct btrfs_fs_info *fs_info) |
| 941 | { |
| 942 | struct btrfs_pending_snapshot *pending; |
| 943 | struct list_head *head = &trans->transaction->pending_snapshots; |
| 944 | int ret; |
| 945 | |
| 946 | list_for_each_entry(pending, head, list) { |
| 947 | ret = create_pending_snapshot(trans, fs_info, pending); |
| 948 | BUG_ON(ret); |
| 949 | } |
| 950 | return 0; |
| 951 | } |
| 952 | |
| 953 | static void update_super_roots(struct btrfs_root *root) |
| 954 | { |
| 955 | struct btrfs_root_item *root_item; |
| 956 | struct btrfs_super_block *super; |
| 957 | |
| 958 | super = &root->fs_info->super_copy; |
| 959 | |
| 960 | root_item = &root->fs_info->chunk_root->root_item; |
| 961 | super->chunk_root = root_item->bytenr; |
| 962 | super->chunk_root_generation = root_item->generation; |
| 963 | super->chunk_root_level = root_item->level; |
| 964 | |
| 965 | root_item = &root->fs_info->tree_root->root_item; |
| 966 | super->root = root_item->bytenr; |
| 967 | super->generation = root_item->generation; |
| 968 | super->root_level = root_item->level; |
| 969 | } |
| 970 | |
| 971 | int btrfs_transaction_in_commit(struct btrfs_fs_info *info) |
| 972 | { |
| 973 | int ret = 0; |
| 974 | spin_lock(&info->new_trans_lock); |
| 975 | if (info->running_transaction) |
| 976 | ret = info->running_transaction->in_commit; |
| 977 | spin_unlock(&info->new_trans_lock); |
| 978 | return ret; |
| 979 | } |
| 980 | |
| 981 | int btrfs_transaction_blocked(struct btrfs_fs_info *info) |
| 982 | { |
| 983 | int ret = 0; |
| 984 | spin_lock(&info->new_trans_lock); |
| 985 | if (info->running_transaction) |
| 986 | ret = info->running_transaction->blocked; |
| 987 | spin_unlock(&info->new_trans_lock); |
| 988 | return ret; |
| 989 | } |
| 990 | |
| 991 | int btrfs_commit_transaction(struct btrfs_trans_handle *trans, |
| 992 | struct btrfs_root *root) |
| 993 | { |
| 994 | unsigned long joined = 0; |
| 995 | unsigned long timeout = 1; |
| 996 | struct btrfs_transaction *cur_trans; |
| 997 | struct btrfs_transaction *prev_trans = NULL; |
| 998 | DEFINE_WAIT(wait); |
| 999 | int ret; |
| 1000 | int should_grow = 0; |
| 1001 | unsigned long now = get_seconds(); |
| 1002 | int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT); |
| 1003 | |
| 1004 | btrfs_run_ordered_operations(root, 0); |
| 1005 | |
| 1006 | /* make a pass through all the delayed refs we have so far |
| 1007 | * any runnings procs may add more while we are here |
| 1008 | */ |
| 1009 | ret = btrfs_run_delayed_refs(trans, root, 0); |
| 1010 | BUG_ON(ret); |
| 1011 | |
| 1012 | btrfs_trans_release_metadata(trans, root); |
| 1013 | |
| 1014 | cur_trans = trans->transaction; |
| 1015 | /* |
| 1016 | * set the flushing flag so procs in this transaction have to |
| 1017 | * start sending their work down. |
| 1018 | */ |
| 1019 | cur_trans->delayed_refs.flushing = 1; |
| 1020 | |
| 1021 | ret = btrfs_run_delayed_refs(trans, root, 0); |
| 1022 | BUG_ON(ret); |
| 1023 | |
| 1024 | mutex_lock(&root->fs_info->trans_mutex); |
| 1025 | if (cur_trans->in_commit) { |
| 1026 | cur_trans->use_count++; |
| 1027 | mutex_unlock(&root->fs_info->trans_mutex); |
| 1028 | btrfs_end_transaction(trans, root); |
| 1029 | |
| 1030 | ret = wait_for_commit(root, cur_trans); |
| 1031 | BUG_ON(ret); |
| 1032 | |
| 1033 | mutex_lock(&root->fs_info->trans_mutex); |
| 1034 | put_transaction(cur_trans); |
| 1035 | mutex_unlock(&root->fs_info->trans_mutex); |
| 1036 | |
| 1037 | return 0; |
| 1038 | } |
| 1039 | |
| 1040 | trans->transaction->in_commit = 1; |
| 1041 | trans->transaction->blocked = 1; |
| 1042 | if (cur_trans->list.prev != &root->fs_info->trans_list) { |
| 1043 | prev_trans = list_entry(cur_trans->list.prev, |
| 1044 | struct btrfs_transaction, list); |
| 1045 | if (!prev_trans->commit_done) { |
| 1046 | prev_trans->use_count++; |
| 1047 | mutex_unlock(&root->fs_info->trans_mutex); |
| 1048 | |
| 1049 | wait_for_commit(root, prev_trans); |
| 1050 | |
| 1051 | mutex_lock(&root->fs_info->trans_mutex); |
| 1052 | put_transaction(prev_trans); |
| 1053 | } |
| 1054 | } |
| 1055 | |
| 1056 | if (now < cur_trans->start_time || now - cur_trans->start_time < 1) |
| 1057 | should_grow = 1; |
| 1058 | |
| 1059 | do { |
| 1060 | int snap_pending = 0; |
| 1061 | joined = cur_trans->num_joined; |
| 1062 | if (!list_empty(&trans->transaction->pending_snapshots)) |
| 1063 | snap_pending = 1; |
| 1064 | |
| 1065 | WARN_ON(cur_trans != trans->transaction); |
| 1066 | if (cur_trans->num_writers > 1) |
| 1067 | timeout = MAX_SCHEDULE_TIMEOUT; |
| 1068 | else if (should_grow) |
| 1069 | timeout = 1; |
| 1070 | |
| 1071 | mutex_unlock(&root->fs_info->trans_mutex); |
| 1072 | |
| 1073 | if (flush_on_commit || snap_pending) { |
| 1074 | btrfs_start_delalloc_inodes(root, 1); |
| 1075 | ret = btrfs_wait_ordered_extents(root, 0, 1); |
| 1076 | BUG_ON(ret); |
| 1077 | } |
| 1078 | |
| 1079 | /* |
| 1080 | * rename don't use btrfs_join_transaction, so, once we |
| 1081 | * set the transaction to blocked above, we aren't going |
| 1082 | * to get any new ordered operations. We can safely run |
| 1083 | * it here and no for sure that nothing new will be added |
| 1084 | * to the list |
| 1085 | */ |
| 1086 | btrfs_run_ordered_operations(root, 1); |
| 1087 | |
| 1088 | prepare_to_wait(&cur_trans->writer_wait, &wait, |
| 1089 | TASK_UNINTERRUPTIBLE); |
| 1090 | |
| 1091 | smp_mb(); |
| 1092 | if (cur_trans->num_writers > 1 || should_grow) |
| 1093 | schedule_timeout(timeout); |
| 1094 | |
| 1095 | mutex_lock(&root->fs_info->trans_mutex); |
| 1096 | finish_wait(&cur_trans->writer_wait, &wait); |
| 1097 | } while (cur_trans->num_writers > 1 || |
| 1098 | (should_grow && cur_trans->num_joined != joined)); |
| 1099 | |
| 1100 | ret = create_pending_snapshots(trans, root->fs_info); |
| 1101 | BUG_ON(ret); |
| 1102 | |
| 1103 | ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); |
| 1104 | BUG_ON(ret); |
| 1105 | |
| 1106 | WARN_ON(cur_trans != trans->transaction); |
| 1107 | |
| 1108 | /* btrfs_commit_tree_roots is responsible for getting the |
| 1109 | * various roots consistent with each other. Every pointer |
| 1110 | * in the tree of tree roots has to point to the most up to date |
| 1111 | * root for every subvolume and other tree. So, we have to keep |
| 1112 | * the tree logging code from jumping in and changing any |
| 1113 | * of the trees. |
| 1114 | * |
| 1115 | * At this point in the commit, there can't be any tree-log |
| 1116 | * writers, but a little lower down we drop the trans mutex |
| 1117 | * and let new people in. By holding the tree_log_mutex |
| 1118 | * from now until after the super is written, we avoid races |
| 1119 | * with the tree-log code. |
| 1120 | */ |
| 1121 | mutex_lock(&root->fs_info->tree_log_mutex); |
| 1122 | |
| 1123 | ret = commit_fs_roots(trans, root); |
| 1124 | BUG_ON(ret); |
| 1125 | |
| 1126 | /* commit_fs_roots gets rid of all the tree log roots, it is now |
| 1127 | * safe to free the root of tree log roots |
| 1128 | */ |
| 1129 | btrfs_free_log_root_tree(trans, root->fs_info); |
| 1130 | |
| 1131 | ret = commit_cowonly_roots(trans, root); |
| 1132 | BUG_ON(ret); |
| 1133 | |
| 1134 | btrfs_prepare_extent_commit(trans, root); |
| 1135 | |
| 1136 | cur_trans = root->fs_info->running_transaction; |
| 1137 | spin_lock(&root->fs_info->new_trans_lock); |
| 1138 | root->fs_info->running_transaction = NULL; |
| 1139 | spin_unlock(&root->fs_info->new_trans_lock); |
| 1140 | |
| 1141 | btrfs_set_root_node(&root->fs_info->tree_root->root_item, |
| 1142 | root->fs_info->tree_root->node); |
| 1143 | switch_commit_root(root->fs_info->tree_root); |
| 1144 | |
| 1145 | btrfs_set_root_node(&root->fs_info->chunk_root->root_item, |
| 1146 | root->fs_info->chunk_root->node); |
| 1147 | switch_commit_root(root->fs_info->chunk_root); |
| 1148 | |
| 1149 | update_super_roots(root); |
| 1150 | |
| 1151 | if (!root->fs_info->log_root_recovering) { |
| 1152 | btrfs_set_super_log_root(&root->fs_info->super_copy, 0); |
| 1153 | btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0); |
| 1154 | } |
| 1155 | |
| 1156 | memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy, |
| 1157 | sizeof(root->fs_info->super_copy)); |
| 1158 | |
| 1159 | trans->transaction->blocked = 0; |
| 1160 | |
| 1161 | wake_up(&root->fs_info->transaction_wait); |
| 1162 | |
| 1163 | mutex_unlock(&root->fs_info->trans_mutex); |
| 1164 | ret = btrfs_write_and_wait_transaction(trans, root); |
| 1165 | BUG_ON(ret); |
| 1166 | write_ctree_super(trans, root, 0); |
| 1167 | |
| 1168 | /* |
| 1169 | * the super is written, we can safely allow the tree-loggers |
| 1170 | * to go about their business |
| 1171 | */ |
| 1172 | mutex_unlock(&root->fs_info->tree_log_mutex); |
| 1173 | |
| 1174 | btrfs_finish_extent_commit(trans, root); |
| 1175 | |
| 1176 | mutex_lock(&root->fs_info->trans_mutex); |
| 1177 | |
| 1178 | cur_trans->commit_done = 1; |
| 1179 | |
| 1180 | root->fs_info->last_trans_committed = cur_trans->transid; |
| 1181 | |
| 1182 | wake_up(&cur_trans->commit_wait); |
| 1183 | |
| 1184 | put_transaction(cur_trans); |
| 1185 | put_transaction(cur_trans); |
| 1186 | |
| 1187 | mutex_unlock(&root->fs_info->trans_mutex); |
| 1188 | |
| 1189 | if (current->journal_info == trans) |
| 1190 | current->journal_info = NULL; |
| 1191 | |
| 1192 | kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| 1193 | |
| 1194 | if (current != root->fs_info->transaction_kthread) |
| 1195 | btrfs_run_delayed_iputs(root); |
| 1196 | |
| 1197 | return ret; |
| 1198 | } |
| 1199 | |
| 1200 | /* |
| 1201 | * interface function to delete all the snapshots we have scheduled for deletion |
| 1202 | */ |
| 1203 | int btrfs_clean_old_snapshots(struct btrfs_root *root) |
| 1204 | { |
| 1205 | LIST_HEAD(list); |
| 1206 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 1207 | |
| 1208 | mutex_lock(&fs_info->trans_mutex); |
| 1209 | list_splice_init(&fs_info->dead_roots, &list); |
| 1210 | mutex_unlock(&fs_info->trans_mutex); |
| 1211 | |
| 1212 | while (!list_empty(&list)) { |
| 1213 | root = list_entry(list.next, struct btrfs_root, root_list); |
| 1214 | list_del(&root->root_list); |
| 1215 | |
| 1216 | if (btrfs_header_backref_rev(root->node) < |
| 1217 | BTRFS_MIXED_BACKREF_REV) |
| 1218 | btrfs_drop_snapshot(root, NULL, 0); |
| 1219 | else |
| 1220 | btrfs_drop_snapshot(root, NULL, 1); |
| 1221 | } |
| 1222 | return 0; |
| 1223 | } |