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   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/sched.h>
  21 #include <linux/writeback.h>
  22 #include <linux/pagemap.h>
  23 #include "ctree.h"
  24 #include "disk-io.h"
  25 #include "transaction.h"
  26
  27 static int total_trans = 0;
  28 extern struct kmem_cache *btrfs_trans_handle_cachep;
  29 extern struct kmem_cache *btrfs_transaction_cachep;
  30
  31 static struct workqueue_struct *trans_wq;
  32
  33 #define BTRFS_ROOT_TRANS_TAG 0
  34 #define BTRFS_ROOT_DEFRAG_TAG 1
  35
  36 static void put_transaction(struct btrfs_transaction *transaction)
  37 {
  38         WARN_ON(transaction->use_count == 0);
  39         transaction->use_count--;
  40         if (transaction->use_count == 0) {
  41                 WARN_ON(total_trans == 0);
  42                 total_trans--;
  43                 list_del_init(&transaction->list);
  44                 memset(transaction, 0, sizeof(*transaction));
  45                 kmem_cache_free(btrfs_transaction_cachep, transaction);
  46         }
  47 }
  48
  49 static int join_transaction(struct btrfs_root *root)
  50 {
  51         struct btrfs_transaction *cur_trans;
  52         cur_trans = root->fs_info->running_transaction;
  53         if (!cur_trans) {
  54                 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
  55                                              GFP_NOFS);
  56                 total_trans++;
  57                 BUG_ON(!cur_trans);
  58                 root->fs_info->generation++;
  59                 root->fs_info->running_transaction = cur_trans;
  60                 cur_trans->num_writers = 1;
  61                 cur_trans->num_joined = 0;
  62                 cur_trans->transid = root->fs_info->generation;
  63                 init_waitqueue_head(&cur_trans->writer_wait);
  64                 init_waitqueue_head(&cur_trans->commit_wait);
  65                 cur_trans->in_commit = 0;
  66                 cur_trans->use_count = 1;
  67                 cur_trans->commit_done = 0;
  68                 cur_trans->start_time = get_seconds();
  69                 list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
  70                 btrfs_ordered_inode_tree_init(&cur_trans->ordered_inode_tree);
  71                 extent_map_tree_init(&cur_trans->dirty_pages,
  72                                      root->fs_info->btree_inode->i_mapping,
  73                                      GFP_NOFS);
  74         } else {
  75                 cur_trans->num_writers++;
  76                 cur_trans->num_joined++;
  77         }
  78
  79         return 0;
  80 }
  81
  82 static int record_root_in_trans(struct btrfs_root *root)
  83 {
  84         u64 running_trans_id = root->fs_info->running_transaction->transid;
  85         if (root->ref_cows && root->last_trans < running_trans_id) {
  86                 WARN_ON(root == root->fs_info->extent_root);
  87                 if (root->root_item.refs != 0) {
  88                         radix_tree_tag_set(&root->fs_info->fs_roots_radix,
  89                                    (unsigned long)root->root_key.objectid,
  90                                    BTRFS_ROOT_TRANS_TAG);
  91                         radix_tree_tag_set(&root->fs_info->fs_roots_radix,
  92                                    (unsigned long)root->root_key.objectid,
  93                                    BTRFS_ROOT_DEFRAG_TAG);
  94                         root->commit_root = root->node;
  95                         extent_buffer_get(root->node);
  96                 } else {
  97                         WARN_ON(1);
  98                 }
  99                 root->last_trans = running_trans_id;
 100         }
 101         return 0;
 102 }
 103
 104 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
 105                                                    int num_blocks)
 106 {
 107         struct btrfs_trans_handle *h =
 108                 kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
 109         int ret;
 110
 111         mutex_lock(&root->fs_info->trans_mutex);
 112         ret = join_transaction(root);
 113         BUG_ON(ret);
 114
 115         record_root_in_trans(root);
 116         h->transid = root->fs_info->running_transaction->transid;
 117         h->transaction = root->fs_info->running_transaction;
 118         h->blocks_reserved = num_blocks;
 119         h->blocks_used = 0;
 120         h->block_group = NULL;
 121         h->alloc_exclude_nr = 0;
 122         h->alloc_exclude_start = 0;
 123         root->fs_info->running_transaction->use_count++;
 124         mutex_unlock(&root->fs_info->trans_mutex);
 125         return h;
 126 }
 127
 128 int btrfs_end_transaction(struct btrfs_trans_handle *trans,
 129                           struct btrfs_root *root)
 130 {
 131         struct btrfs_transaction *cur_trans;
 132
 133         mutex_lock(&root->fs_info->trans_mutex);
 134         cur_trans = root->fs_info->running_transaction;
 135         WARN_ON(cur_trans != trans->transaction);
 136         WARN_ON(cur_trans->num_writers < 1);
 137         cur_trans->num_writers--;
 138         if (waitqueue_active(&cur_trans->writer_wait))
 139                 wake_up(&cur_trans->writer_wait);
 140         put_transaction(cur_trans);
 141         mutex_unlock(&root->fs_info->trans_mutex);
 142         memset(trans, 0, sizeof(*trans));
 143         kmem_cache_free(btrfs_trans_handle_cachep, trans);
 144         return 0;
 145 }
 146
 147
 148 int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
 149                                      struct btrfs_root *root)
 150 {
 151         int ret;
 152         int err;
 153         int werr = 0;
 154         struct extent_map_tree *dirty_pages;
 155         struct page *page;
 156         struct inode *btree_inode = root->fs_info->btree_inode;
 157         u64 start;
 158         u64 end;
 159         unsigned long index;
 160
 161         if (!trans || !trans->transaction) {
 162                 return filemap_write_and_wait(btree_inode->i_mapping);
 163         }
 164         dirty_pages = &trans->transaction->dirty_pages;
 165         while(1) {
 166                 ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
 167                                             EXTENT_DIRTY);
 168                 if (ret)
 169                         break;
 170                 clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
 171                 while(start <= end) {
 172                         index = start >> PAGE_CACHE_SHIFT;
 173                         start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
 174                         page = find_lock_page(btree_inode->i_mapping, index);
 175                         if (!page)
 176                                 continue;
 177                         if (PageWriteback(page)) {
 178                                 if (PageDirty(page))
 179                                         wait_on_page_writeback(page);
 180                                 else {
 181                                         unlock_page(page);
 182                                         page_cache_release(page);
 183                                         continue;
 184                                 }
 185                         }
 186                         err = write_one_page(page, 0);
 187                         if (err)
 188                                 werr = err;
 189                         page_cache_release(page);
 190                 }
 191         }
 192         err = filemap_fdatawait(btree_inode->i_mapping);
 193         if (err)
 194                 werr = err;
 195         return werr;
 196 }
 197
 198 int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
 199                             struct btrfs_root *root)
 200 {
 201         int ret;
 202         u64 old_extent_block;
 203         struct btrfs_fs_info *fs_info = root->fs_info;
 204         struct btrfs_root *tree_root = fs_info->tree_root;
 205         struct btrfs_root *extent_root = fs_info->extent_root;
 206
 207         btrfs_write_dirty_block_groups(trans, extent_root);
 208         while(1) {
 209                 old_extent_block = btrfs_root_bytenr(&extent_root->root_item);
 210                 if (old_extent_block == extent_root->node->start)
 211                         break;
 212                 btrfs_set_root_bytenr(&extent_root->root_item,
 213                                       extent_root->node->start);
 214                 btrfs_set_root_level(&extent_root->root_item,
 215                                      btrfs_header_level(extent_root->node));
 216                 ret = btrfs_update_root(trans, tree_root,
 217                                         &extent_root->root_key,
 218                                         &extent_root->root_item);
 219                 BUG_ON(ret);
 220                 btrfs_write_dirty_block_groups(trans, extent_root);
 221         }
 222         return 0;
 223 }
 224
 225 static int wait_for_commit(struct btrfs_root *root,
 226                            struct btrfs_transaction *commit)
 227 {
 228         DEFINE_WAIT(wait);
 229         mutex_lock(&root->fs_info->trans_mutex);
 230         while(!commit->commit_done) {
 231                 prepare_to_wait(&commit->commit_wait, &wait,
 232                                 TASK_UNINTERRUPTIBLE);
 233                 if (commit->commit_done)
 234                         break;
 235                 mutex_unlock(&root->fs_info->trans_mutex);
 236                 schedule();
 237                 mutex_lock(&root->fs_info->trans_mutex);
 238         }
 239         mutex_unlock(&root->fs_info->trans_mutex);
 240         finish_wait(&commit->commit_wait, &wait);
 241         return 0;
 242 }
 243
 244 struct dirty_root {
 245         struct list_head list;
 246         struct btrfs_root *root;
 247         struct btrfs_root *latest_root;
 248 };
 249
 250 int btrfs_add_dead_root(struct btrfs_root *root,
 251                         struct btrfs_root *latest,
 252                         struct list_head *dead_list)
 253 {
 254         struct dirty_root *dirty;
 255
 256         dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
 257         if (!dirty)
 258                 return -ENOMEM;
 259         dirty->root = root;
 260         dirty->latest_root = latest;
 261         list_add(&dirty->list, dead_list);
 262         return 0;
 263 }
 264
 265 static int add_dirty_roots(struct btrfs_trans_handle *trans,
 266                            struct radix_tree_root *radix,
 267                            struct list_head *list)
 268 {
 269         struct dirty_root *dirty;
 270         struct btrfs_root *gang[8];
 271         struct btrfs_root *root;
 272         int i;
 273         int ret;
 274         int err = 0;
 275         u32 refs;
 276
 277         while(1) {
 278                 ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
 279                                                  ARRAY_SIZE(gang),
 280                                                  BTRFS_ROOT_TRANS_TAG);
 281                 if (ret == 0)
 282                         break;
 283                 for (i = 0; i < ret; i++) {
 284                         root = gang[i];
 285                         radix_tree_tag_clear(radix,
 286                                      (unsigned long)root->root_key.objectid,
 287                                      BTRFS_ROOT_TRANS_TAG);
 288                         if (root->commit_root == root->node) {
 289                                 WARN_ON(root->node->start !=
 290                                         btrfs_root_bytenr(&root->root_item));
 291                                 free_extent_buffer(root->commit_root);
 292                                 root->commit_root = NULL;
 293
 294                                 /* make sure to update the root on disk
 295                                  * so we get any updates to the block used
 296                                  * counts
 297                                  */
 298                                 err = btrfs_update_root(trans,
 299                                                 root->fs_info->tree_root,
 300                                                 &root->root_key,
 301                                                 &root->root_item);
 302                                 continue;
 303                         }
 304                         dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
 305                         BUG_ON(!dirty);
 306                         dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
 307                         BUG_ON(!dirty->root);
 308
 309                         memset(&root->root_item.drop_progress, 0,
 310                                sizeof(struct btrfs_disk_key));
 311                         root->root_item.drop_level = 0;
 312
 313                         memcpy(dirty->root, root, sizeof(*root));
 314                         dirty->root->node = root->commit_root;
 315                         dirty->latest_root = root;
 316                         root->commit_root = NULL;
 317
 318                         root->root_key.offset = root->fs_info->generation;
 319                         btrfs_set_root_bytenr(&root->root_item,
 320                                               root->node->start);
 321                         btrfs_set_root_level(&root->root_item,
 322                                              btrfs_header_level(root->node));
 323                         err = btrfs_insert_root(trans, root->fs_info->tree_root,
 324                                                 &root->root_key,
 325                                                 &root->root_item);
 326                         if (err)
 327                                 break;
 328
 329                         refs = btrfs_root_refs(&dirty->root->root_item);
 330                         btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
 331                         err = btrfs_update_root(trans, root->fs_info->tree_root,
 332                                                 &dirty->root->root_key,
 333                                                 &dirty->root->root_item);
 334
 335                         BUG_ON(err);
 336                         if (refs == 1) {
 337                                 list_add(&dirty->list, list);
 338                         } else {
 339                                 WARN_ON(1);
 340                                 kfree(dirty->root);
 341                                 kfree(dirty);
 342                         }
 343                 }
 344         }
 345         return err;
 346 }
 347
 348 int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
 349 {
 350         struct btrfs_fs_info *info = root->fs_info;
 351         int ret;
 352         struct btrfs_trans_handle *trans;
 353         unsigned long nr;
 354
 355         if (root->defrag_running)
 356                 return 0;
 357         trans = btrfs_start_transaction(root, 1);
 358         while (1) {
 359                 root->defrag_running = 1;
 360                 ret = btrfs_defrag_leaves(trans, root, cacheonly);
 361                 nr = trans->blocks_used;
 362                 btrfs_end_transaction(trans, root);
 363                 mutex_unlock(&info->fs_mutex);
 364                 btrfs_btree_balance_dirty(info->tree_root, nr);
 365                 cond_resched();
 366
 367                 mutex_lock(&info->fs_mutex);
 368                 trans = btrfs_start_transaction(root, 1);
 369                 if (ret != -EAGAIN)
 370                         break;
 371         }
 372         root->defrag_running = 0;
 373         radix_tree_tag_clear(&info->fs_roots_radix,
 374                      (unsigned long)root->root_key.objectid,
 375                      BTRFS_ROOT_DEFRAG_TAG);
 376         btrfs_end_transaction(trans, root);
 377         return 0;
 378 }
 379
 380 int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
 381 {
 382         struct btrfs_root *gang[1];
 383         struct btrfs_root *root;
 384         int i;
 385         int ret;
 386         int err = 0;
 387         u64 last = 0;
 388
 389         while(1) {
 390                 ret = radix_tree_gang_lookup_tag(&info->fs_roots_radix,
 391                                                  (void **)gang, last,
 392                                                  ARRAY_SIZE(gang),
 393                                                  BTRFS_ROOT_DEFRAG_TAG);
 394                 if (ret == 0)
 395                         break;
 396                 for (i = 0; i < ret; i++) {
 397                         root = gang[i];
 398                         last = root->root_key.objectid + 1;
 399                         btrfs_defrag_root(root, 1);
 400                 }
 401         }
 402         btrfs_defrag_root(info->extent_root, 1);
 403         return err;
 404 }
 405
 406 static int drop_dirty_roots(struct btrfs_root *tree_root,
 407                             struct list_head *list)
 408 {
 409         struct dirty_root *dirty;
 410         struct btrfs_trans_handle *trans;
 411         unsigned long nr;
 412         u64 num_bytes;
 413         u64 bytes_used;
 414         int ret = 0;
 415         int err;
 416
 417         while(!list_empty(list)) {
 418                 struct btrfs_root *root;
 419
 420                 mutex_lock(&tree_root->fs_info->fs_mutex);
 421                 dirty = list_entry(list->next, struct dirty_root, list);
 422                 list_del_init(&dirty->list);
 423
 424                 num_bytes = btrfs_root_used(&dirty->root->root_item);
 425                 root = dirty->latest_root;
 426
 427                 while(1) {
 428                         trans = btrfs_start_transaction(tree_root, 1);
 429                         ret = btrfs_drop_snapshot(trans, dirty->root);
 430                         if (ret != -EAGAIN) {
 431                                 break;
 432                         }
 433
 434                         err = btrfs_update_root(trans,
 435                                         tree_root,
 436                                         &dirty->root->root_key,
 437                                         &dirty->root->root_item);
 438                         if (err)
 439                                 ret = err;
 440                         nr = trans->blocks_used;
 441                         ret = btrfs_end_transaction(trans, tree_root);
 442                         BUG_ON(ret);
 443                         mutex_unlock(&tree_root->fs_info->fs_mutex);
 444                         btrfs_btree_balance_dirty(tree_root, nr);
 445                         cond_resched();
 446                         mutex_lock(&tree_root->fs_info->fs_mutex);
 447                 }
 448                 BUG_ON(ret);
 449
 450                 num_bytes -= btrfs_root_used(&dirty->root->root_item);
 451                 bytes_used = btrfs_root_used(&root->root_item);
 452                 if (num_bytes) {
 453                         record_root_in_trans(root);
 454                         btrfs_set_root_used(&root->root_item,
 455                                             bytes_used - num_bytes);
 456                 }
 457                 ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
 458                 if (ret) {
 459                         BUG();
 460                         break;
 461                 }
 462                 nr = trans->blocks_used;
 463                 ret = btrfs_end_transaction(trans, tree_root);
 464                 BUG_ON(ret);
 465
 466                 free_extent_buffer(dirty->root->node);
 467                 kfree(dirty->root);
 468                 kfree(dirty);
 469                 mutex_unlock(&tree_root->fs_info->fs_mutex);
 470
 471                 btrfs_btree_balance_dirty(tree_root, nr);
 472                 cond_resched();
 473         }
 474         return ret;
 475 }
 476
 477 int btrfs_write_ordered_inodes(struct btrfs_trans_handle *trans,
 478                                 struct btrfs_root *root)
 479 {
 480         struct btrfs_transaction *cur_trans = trans->transaction;
 481         struct inode *inode;
 482         u64 root_objectid = 0;
 483         u64 objectid = 0;
 484         u64 transid = trans->transid;
 485         int ret;
 486
 487 printk("write ordered trans %Lu\n", transid);
 488         while(1) {
 489                 ret = btrfs_find_first_ordered_inode(
 490                                 &cur_trans->ordered_inode_tree,
 491                                 &root_objectid, &objectid);
 492                 if (!ret)
 493                         break;
 494
 495                 mutex_unlock(&root->fs_info->trans_mutex);
 496                 mutex_unlock(&root->fs_info->fs_mutex);
 497                 inode = btrfs_ilookup(root->fs_info->sb, objectid,
 498                                       root_objectid);
 499                 if (inode) {
 500                         if (S_ISREG(inode->i_mode))
 501                                 filemap_fdatawrite(inode->i_mapping);
 502                         iput(inode);
 503                 }
 504                 mutex_lock(&root->fs_info->fs_mutex);
 505                 mutex_lock(&root->fs_info->trans_mutex);
 506         }
 507         while(1) {
 508                 root_objectid = 0;
 509                 objectid = 0;
 510                 ret = btrfs_find_del_first_ordered_inode(
 511                                 &cur_trans->ordered_inode_tree,
 512                                 &root_objectid, &objectid);
 513                 if (!ret)
 514                         break;
 515                 mutex_unlock(&root->fs_info->trans_mutex);
 516                 mutex_unlock(&root->fs_info->fs_mutex);
 517                 inode = btrfs_ilookup(root->fs_info->sb, objectid,
 518                                       root_objectid);
 519                 if (inode) {
 520                         if (S_ISREG(inode->i_mode))
 521                                 filemap_write_and_wait(inode->i_mapping);
 522                         iput(inode);
 523                 }
 524                 mutex_lock(&root->fs_info->fs_mutex);
 525                 mutex_lock(&root->fs_info->trans_mutex);
 526         }
 527 printk("done write ordered trans %Lu\n", transid);
 528         return 0;
 529 }
 530
 531 int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 532                              struct btrfs_root *root)
 533 {
 534         unsigned long joined = 0;
 535         unsigned long timeout = 1;
 536         struct btrfs_transaction *cur_trans;
 537         struct btrfs_transaction *prev_trans = NULL;
 538         struct list_head dirty_fs_roots;
 539         struct extent_map_tree *pinned_copy;
 540         DEFINE_WAIT(wait);
 541         int ret;
 542
 543         INIT_LIST_HEAD(&dirty_fs_roots);
 544
 545         mutex_lock(&root->fs_info->trans_mutex);
 546         if (trans->transaction->in_commit) {
 547                 cur_trans = trans->transaction;
 548                 trans->transaction->use_count++;
 549                 mutex_unlock(&root->fs_info->trans_mutex);
 550                 btrfs_end_transaction(trans, root);
 551
 552                 mutex_unlock(&root->fs_info->fs_mutex);
 553                 ret = wait_for_commit(root, cur_trans);
 554                 BUG_ON(ret);
 555
 556                 mutex_lock(&root->fs_info->trans_mutex);
 557                 put_transaction(cur_trans);
 558                 mutex_unlock(&root->fs_info->trans_mutex);
 559
 560                 mutex_lock(&root->fs_info->fs_mutex);
 561                 return 0;
 562         }
 563
 564         pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
 565         if (!pinned_copy)
 566                 return -ENOMEM;
 567
 568         extent_map_tree_init(pinned_copy,
 569                              root->fs_info->btree_inode->i_mapping, GFP_NOFS);
 570
 571         trans->transaction->in_commit = 1;
 572         cur_trans = trans->transaction;
 573         if (cur_trans->list.prev != &root->fs_info->trans_list) {
 574                 prev_trans = list_entry(cur_trans->list.prev,
 575                                         struct btrfs_transaction, list);
 576                 if (!prev_trans->commit_done) {
 577                         prev_trans->use_count++;
 578                         mutex_unlock(&root->fs_info->fs_mutex);
 579                         mutex_unlock(&root->fs_info->trans_mutex);
 580
 581                         wait_for_commit(root, prev_trans);
 582
 583                         mutex_lock(&root->fs_info->fs_mutex);
 584                         mutex_lock(&root->fs_info->trans_mutex);
 585                         put_transaction(prev_trans);
 586                 }
 587         }
 588
 589         do {
 590                 joined = cur_trans->num_joined;
 591                 WARN_ON(cur_trans != trans->transaction);
 592                 prepare_to_wait(&cur_trans->writer_wait, &wait,
 593                                 TASK_UNINTERRUPTIBLE);
 594
 595                 if (cur_trans->num_writers > 1)
 596                         timeout = MAX_SCHEDULE_TIMEOUT;
 597                 else
 598                         timeout = 1;
 599
 600                 mutex_unlock(&root->fs_info->fs_mutex);
 601                 mutex_unlock(&root->fs_info->trans_mutex);
 602
 603                 schedule_timeout(timeout);
 604
 605                 mutex_lock(&root->fs_info->fs_mutex);
 606                 mutex_lock(&root->fs_info->trans_mutex);
 607                 finish_wait(&cur_trans->writer_wait, &wait);
 608                 ret = btrfs_write_ordered_inodes(trans, root);
 609
 610         } while (cur_trans->num_writers > 1 ||
 611                  (cur_trans->num_joined != joined));
 612
 613         WARN_ON(cur_trans != trans->transaction);
 614
 615         ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
 616                               &dirty_fs_roots);
 617         BUG_ON(ret);
 618
 619         ret = btrfs_commit_tree_roots(trans, root);
 620         BUG_ON(ret);
 621
 622         cur_trans = root->fs_info->running_transaction;
 623         root->fs_info->running_transaction = NULL;
 624         btrfs_set_super_generation(&root->fs_info->super_copy,
 625                                    cur_trans->transid);
 626         btrfs_set_super_root(&root->fs_info->super_copy,
 627                              root->fs_info->tree_root->node->start);
 628         btrfs_set_super_root_level(&root->fs_info->super_copy,
 629                            btrfs_header_level(root->fs_info->tree_root->node));
 630
 631         write_extent_buffer(root->fs_info->sb_buffer,
 632                             &root->fs_info->super_copy, 0,
 633                             sizeof(root->fs_info->super_copy));
 634
 635         btrfs_copy_pinned(root, pinned_copy);
 636
 637         mutex_unlock(&root->fs_info->trans_mutex);
 638         mutex_unlock(&root->fs_info->fs_mutex);
 639         ret = btrfs_write_and_wait_transaction(trans, root);
 640         BUG_ON(ret);
 641         write_ctree_super(trans, root);
 642
 643         mutex_lock(&root->fs_info->fs_mutex);
 644         btrfs_finish_extent_commit(trans, root, pinned_copy);
 645         mutex_lock(&root->fs_info->trans_mutex);
 646
 647         kfree(pinned_copy);
 648
 649         cur_trans->commit_done = 1;
 650         root->fs_info->last_trans_committed = cur_trans->transid;
 651         wake_up(&cur_trans->commit_wait);
 652         put_transaction(cur_trans);
 653         put_transaction(cur_trans);
 654
 655         if (root->fs_info->closing)
 656                 list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
 657         else
 658                 list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
 659
 660         mutex_unlock(&root->fs_info->trans_mutex);
 661         kmem_cache_free(btrfs_trans_handle_cachep, trans);
 662
 663         if (root->fs_info->closing) {
 664                 mutex_unlock(&root->fs_info->fs_mutex);
 665                 drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
 666                 mutex_lock(&root->fs_info->fs_mutex);
 667         }
 668         return ret;
 669 }
 670
 671 int btrfs_clean_old_snapshots(struct btrfs_root *root)
 672 {
 673         struct list_head dirty_roots;
 674         INIT_LIST_HEAD(&dirty_roots);
 675
 676         mutex_lock(&root->fs_info->trans_mutex);
 677         list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
 678         mutex_unlock(&root->fs_info->trans_mutex);
 679
 680         if (!list_empty(&dirty_roots)) {
 681                 drop_dirty_roots(root, &dirty_roots);
 682         }
 683         return 0;
 684 }
 685 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 686 void btrfs_transaction_cleaner(void *p)
 687 #else
 688 void btrfs_transaction_cleaner(struct work_struct *work)
 689 #endif
 690 {
 691 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 692         struct btrfs_fs_info *fs_info = p;
 693 #else
 694         struct btrfs_fs_info *fs_info = container_of(work,
 695                                                      struct btrfs_fs_info,
 696                                                      trans_work.work);
 697
 698 #endif
 699         struct btrfs_root *root = fs_info->tree_root;
 700         struct btrfs_transaction *cur;
 701         struct btrfs_trans_handle *trans;
 702         unsigned long now;
 703         unsigned long delay = HZ * 30;
 704         int ret;
 705
 706         mutex_lock(&root->fs_info->fs_mutex);
 707         mutex_lock(&root->fs_info->trans_mutex);
 708         cur = root->fs_info->running_transaction;
 709         if (!cur) {
 710                 mutex_unlock(&root->fs_info->trans_mutex);
 711                 goto out;
 712         }
 713         now = get_seconds();
 714         if (now < cur->start_time || now - cur->start_time < 30) {
 715                 mutex_unlock(&root->fs_info->trans_mutex);
 716                 delay = HZ * 5;
 717                 goto out;
 718         }
 719         mutex_unlock(&root->fs_info->trans_mutex);
 720         btrfs_defrag_dirty_roots(root->fs_info);
 721         trans = btrfs_start_transaction(root, 1);
 722         ret = btrfs_commit_transaction(trans, root);
 723 out:
 724         mutex_unlock(&root->fs_info->fs_mutex);
 725         btrfs_clean_old_snapshots(root);
 726         btrfs_transaction_queue_work(root, delay);
 727 }
 728
 729 void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
 730 {
 731         queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
 732 }
 733
 734 void btrfs_transaction_flush_work(struct btrfs_root *root)
 735 {
 736         cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
 737         flush_workqueue(trans_wq);
 738 }
 739
 740 void __init btrfs_init_transaction_sys(void)
 741 {
 742         trans_wq = create_workqueue("btrfs");
 743 }
 744
 745 void btrfs_exit_transaction_sys(void)
 746 {
 747         destroy_workqueue(trans_wq);
 748 }
 749