179154b1bSChris Mason #include <linux/module.h> 279154b1bSChris Mason #include <linux/fs.h> 379154b1bSChris Mason #include "ctree.h" 479154b1bSChris Mason #include "disk-io.h" 579154b1bSChris Mason #include "transaction.h" 679154b1bSChris Mason 778fae27eSChris Mason static int total_trans = 0; 82c90e5d6SChris Mason extern struct kmem_cache *btrfs_trans_handle_cachep; 92c90e5d6SChris Mason extern struct kmem_cache *btrfs_transaction_cachep; 102c90e5d6SChris Mason 110f7d52f4SChris Mason #define BTRFS_ROOT_TRANS_TAG 0 120f7d52f4SChris Mason 132c90e5d6SChris Mason #define TRANS_MAGIC 0xE1E10E 1479154b1bSChris Mason static void put_transaction(struct btrfs_transaction *transaction) 1579154b1bSChris Mason { 162c90e5d6SChris Mason WARN_ON(transaction->use_count == 0); 1779154b1bSChris Mason transaction->use_count--; 182c90e5d6SChris Mason WARN_ON(transaction->magic != TRANS_MAGIC); 1978fae27eSChris Mason if (transaction->use_count == 0) { 2078fae27eSChris Mason WARN_ON(total_trans == 0); 2178fae27eSChris Mason total_trans--; 222c90e5d6SChris Mason memset(transaction, 0, sizeof(*transaction)); 232c90e5d6SChris Mason kmem_cache_free(btrfs_transaction_cachep, transaction); 2479154b1bSChris Mason } 2578fae27eSChris Mason } 2679154b1bSChris Mason 2779154b1bSChris Mason static int join_transaction(struct btrfs_root *root) 2879154b1bSChris Mason { 2979154b1bSChris Mason struct btrfs_transaction *cur_trans; 3079154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 3179154b1bSChris Mason if (!cur_trans) { 322c90e5d6SChris Mason cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, 332c90e5d6SChris Mason GFP_NOFS); 3478fae27eSChris Mason total_trans++; 3579154b1bSChris Mason BUG_ON(!cur_trans); 360f7d52f4SChris Mason root->fs_info->generation++; 3779154b1bSChris Mason root->fs_info->running_transaction = cur_trans; 3879154b1bSChris Mason cur_trans->num_writers = 0; 390f7d52f4SChris Mason cur_trans->transid = root->fs_info->generation; 4079154b1bSChris Mason init_waitqueue_head(&cur_trans->writer_wait); 4179154b1bSChris Mason init_waitqueue_head(&cur_trans->commit_wait); 422c90e5d6SChris Mason cur_trans->magic = TRANS_MAGIC; 4379154b1bSChris Mason cur_trans->in_commit = 0; 44d5719762SChris Mason cur_trans->use_count = 1; 4579154b1bSChris Mason cur_trans->commit_done = 0; 4679154b1bSChris Mason } 4779154b1bSChris Mason cur_trans->num_writers++; 4879154b1bSChris Mason return 0; 4979154b1bSChris Mason } 5079154b1bSChris Mason 5179154b1bSChris Mason struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 5279154b1bSChris Mason int num_blocks) 5379154b1bSChris Mason { 542c90e5d6SChris Mason struct btrfs_trans_handle *h = 552c90e5d6SChris Mason kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); 5679154b1bSChris Mason int ret; 570f7d52f4SChris Mason u64 running_trans_id; 5879154b1bSChris Mason 5979154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 6079154b1bSChris Mason ret = join_transaction(root); 6179154b1bSChris Mason BUG_ON(ret); 620f7d52f4SChris Mason running_trans_id = root->fs_info->running_transaction->transid; 630f7d52f4SChris Mason 640f7d52f4SChris Mason if (root != root->fs_info->tree_root && root->last_trans < 650f7d52f4SChris Mason running_trans_id) { 660f7d52f4SChris Mason radix_tree_tag_set(&root->fs_info->fs_roots_radix, 672619ba1fSChris Mason (unsigned long)root->root_key.objectid, 682619ba1fSChris Mason BTRFS_ROOT_TRANS_TAG); 690f7d52f4SChris Mason root->commit_root = root->node; 700f7d52f4SChris Mason get_bh(root->node); 710f7d52f4SChris Mason } 720f7d52f4SChris Mason root->last_trans = running_trans_id; 730f7d52f4SChris Mason h->transid = running_trans_id; 7479154b1bSChris Mason h->transaction = root->fs_info->running_transaction; 7579154b1bSChris Mason h->blocks_reserved = num_blocks; 7679154b1bSChris Mason h->blocks_used = 0; 7779154b1bSChris Mason root->fs_info->running_transaction->use_count++; 7879154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 792c90e5d6SChris Mason h->magic = h->magic2 = TRANS_MAGIC; 8079154b1bSChris Mason return h; 8179154b1bSChris Mason } 8279154b1bSChris Mason 8379154b1bSChris Mason int btrfs_end_transaction(struct btrfs_trans_handle *trans, 8479154b1bSChris Mason struct btrfs_root *root) 8579154b1bSChris Mason { 8679154b1bSChris Mason struct btrfs_transaction *cur_trans; 87d6e4a428SChris Mason 882c90e5d6SChris Mason WARN_ON(trans->magic != TRANS_MAGIC); 892c90e5d6SChris Mason WARN_ON(trans->magic2 != TRANS_MAGIC); 9079154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 9179154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 92d5719762SChris Mason WARN_ON(cur_trans->num_writers < 1); 9379154b1bSChris Mason if (waitqueue_active(&cur_trans->writer_wait)) 9479154b1bSChris Mason wake_up(&cur_trans->writer_wait); 9579154b1bSChris Mason cur_trans->num_writers--; 9679154b1bSChris Mason put_transaction(cur_trans); 9779154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 98d6025579SChris Mason memset(trans, 0, sizeof(*trans)); 992c90e5d6SChris Mason kmem_cache_free(btrfs_trans_handle_cachep, trans); 10079154b1bSChris Mason return 0; 10179154b1bSChris Mason } 10279154b1bSChris Mason 10379154b1bSChris Mason 10479154b1bSChris Mason int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, 10579154b1bSChris Mason struct btrfs_root *root) 10679154b1bSChris Mason { 1077cfcc17eSChris Mason filemap_write_and_wait(root->fs_info->btree_inode->i_mapping); 10879154b1bSChris Mason return 0; 10979154b1bSChris Mason } 11079154b1bSChris Mason 11179154b1bSChris Mason int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans, 11279154b1bSChris Mason struct btrfs_root *root) 11379154b1bSChris Mason { 11479154b1bSChris Mason int ret; 11579154b1bSChris Mason u64 old_extent_block; 11679154b1bSChris Mason struct btrfs_fs_info *fs_info = root->fs_info; 11779154b1bSChris Mason struct btrfs_root *tree_root = fs_info->tree_root; 11879154b1bSChris Mason struct btrfs_root *extent_root = fs_info->extent_root; 1198352d8a4SChris Mason struct btrfs_root *dev_root = fs_info->dev_root; 12079154b1bSChris Mason 1218352d8a4SChris Mason if (btrfs_super_device_root(fs_info->disk_super) != 1228352d8a4SChris Mason bh_blocknr(dev_root->node)) { 1238352d8a4SChris Mason btrfs_set_super_device_root(fs_info->disk_super, 1248352d8a4SChris Mason bh_blocknr(dev_root->node)); 1258352d8a4SChris Mason } 12679154b1bSChris Mason while(1) { 12779154b1bSChris Mason old_extent_block = btrfs_root_blocknr(&extent_root->root_item); 1287eccb903SChris Mason if (old_extent_block == bh_blocknr(extent_root->node)) 12979154b1bSChris Mason break; 13079154b1bSChris Mason btrfs_set_root_blocknr(&extent_root->root_item, 1317eccb903SChris Mason bh_blocknr(extent_root->node)); 13279154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 13379154b1bSChris Mason &extent_root->root_key, 13479154b1bSChris Mason &extent_root->root_item); 13579154b1bSChris Mason BUG_ON(ret); 13679154b1bSChris Mason } 13779154b1bSChris Mason return 0; 13879154b1bSChris Mason } 13979154b1bSChris Mason 14079154b1bSChris Mason static int wait_for_commit(struct btrfs_root *root, 14179154b1bSChris Mason struct btrfs_transaction *commit) 14279154b1bSChris Mason { 14379154b1bSChris Mason DEFINE_WAIT(wait); 14479154b1bSChris Mason while(!commit->commit_done) { 14579154b1bSChris Mason prepare_to_wait(&commit->commit_wait, &wait, 14679154b1bSChris Mason TASK_UNINTERRUPTIBLE); 14779154b1bSChris Mason if (commit->commit_done) 14879154b1bSChris Mason break; 14979154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 15079154b1bSChris Mason schedule(); 15179154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 15279154b1bSChris Mason } 15379154b1bSChris Mason finish_wait(&commit->commit_wait, &wait); 15479154b1bSChris Mason return 0; 15579154b1bSChris Mason } 15679154b1bSChris Mason 1570f7d52f4SChris Mason struct dirty_root { 1580f7d52f4SChris Mason struct list_head list; 1590f7d52f4SChris Mason struct btrfs_key snap_key; 1600f7d52f4SChris Mason struct buffer_head *commit_root; 1610f7d52f4SChris Mason struct btrfs_root *root; 1620f7d52f4SChris Mason }; 1630f7d52f4SChris Mason 1640f7d52f4SChris Mason int add_dirty_roots(struct btrfs_trans_handle *trans, 1650f7d52f4SChris Mason struct radix_tree_root *radix, struct list_head *list) 1660f7d52f4SChris Mason { 1670f7d52f4SChris Mason struct dirty_root *dirty; 1680f7d52f4SChris Mason struct btrfs_root *gang[8]; 1690f7d52f4SChris Mason struct btrfs_root *root; 1700f7d52f4SChris Mason int i; 1710f7d52f4SChris Mason int ret; 1720f7d52f4SChris Mason int err; 1730f7d52f4SChris Mason while(1) { 1740f7d52f4SChris Mason ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0, 1750f7d52f4SChris Mason ARRAY_SIZE(gang), 1760f7d52f4SChris Mason BTRFS_ROOT_TRANS_TAG); 1770f7d52f4SChris Mason if (ret == 0) 1780f7d52f4SChris Mason break; 1790f7d52f4SChris Mason for (i = 0; i < ret; i++) { 1800f7d52f4SChris Mason root = gang[i]; 1812619ba1fSChris Mason radix_tree_tag_clear(radix, 1822619ba1fSChris Mason (unsigned long)root->root_key.objectid, 1830f7d52f4SChris Mason BTRFS_ROOT_TRANS_TAG); 1840f7d52f4SChris Mason if (root->commit_root == root->node) { 1857eccb903SChris Mason WARN_ON(bh_blocknr(root->node) != 1860f7d52f4SChris Mason btrfs_root_blocknr(&root->root_item)); 1870f7d52f4SChris Mason brelse(root->commit_root); 1880f7d52f4SChris Mason root->commit_root = NULL; 1890f7d52f4SChris Mason continue; 1900f7d52f4SChris Mason } 1910f7d52f4SChris Mason dirty = kmalloc(sizeof(*dirty), GFP_NOFS); 1920f7d52f4SChris Mason BUG_ON(!dirty); 1930f7d52f4SChris Mason memcpy(&dirty->snap_key, &root->root_key, 1940f7d52f4SChris Mason sizeof(root->root_key)); 1950f7d52f4SChris Mason dirty->commit_root = root->commit_root; 1960f7d52f4SChris Mason root->commit_root = NULL; 1970f7d52f4SChris Mason dirty->root = root; 1980f7d52f4SChris Mason root->root_key.offset = root->fs_info->generation; 1990f7d52f4SChris Mason btrfs_set_root_blocknr(&root->root_item, 2007eccb903SChris Mason bh_blocknr(root->node)); 2010f7d52f4SChris Mason err = btrfs_insert_root(trans, root->fs_info->tree_root, 2020f7d52f4SChris Mason &root->root_key, 2030f7d52f4SChris Mason &root->root_item); 2040f7d52f4SChris Mason BUG_ON(err); 2050f7d52f4SChris Mason list_add(&dirty->list, list); 2060f7d52f4SChris Mason } 2070f7d52f4SChris Mason } 2080f7d52f4SChris Mason return 0; 2090f7d52f4SChris Mason } 2100f7d52f4SChris Mason 2110f7d52f4SChris Mason int drop_dirty_roots(struct btrfs_root *tree_root, struct list_head *list) 2120f7d52f4SChris Mason { 2130f7d52f4SChris Mason struct dirty_root *dirty; 2140f7d52f4SChris Mason struct btrfs_trans_handle *trans; 2150f7d52f4SChris Mason int ret; 2160f7d52f4SChris Mason 2170f7d52f4SChris Mason while(!list_empty(list)) { 2180f7d52f4SChris Mason dirty = list_entry(list->next, struct dirty_root, list); 2190f7d52f4SChris Mason list_del_init(&dirty->list); 2200f7d52f4SChris Mason trans = btrfs_start_transaction(tree_root, 1); 2210f7d52f4SChris Mason ret = btrfs_drop_snapshot(trans, dirty->root, 2220f7d52f4SChris Mason dirty->commit_root); 2230f7d52f4SChris Mason BUG_ON(ret); 2240f7d52f4SChris Mason 2250f7d52f4SChris Mason ret = btrfs_del_root(trans, tree_root, &dirty->snap_key); 2260f7d52f4SChris Mason BUG_ON(ret); 2270f7d52f4SChris Mason ret = btrfs_end_transaction(trans, tree_root); 2280f7d52f4SChris Mason BUG_ON(ret); 2290f7d52f4SChris Mason kfree(dirty); 2300f7d52f4SChris Mason } 2310f7d52f4SChris Mason return 0; 2320f7d52f4SChris Mason } 2330f7d52f4SChris Mason 23479154b1bSChris Mason int btrfs_commit_transaction(struct btrfs_trans_handle *trans, 23579154b1bSChris Mason struct btrfs_root *root) 23679154b1bSChris Mason { 23779154b1bSChris Mason int ret = 0; 23879154b1bSChris Mason struct btrfs_transaction *cur_trans; 2390f7d52f4SChris Mason struct list_head dirty_fs_roots; 24079154b1bSChris Mason DEFINE_WAIT(wait); 24179154b1bSChris Mason 2420f7d52f4SChris Mason INIT_LIST_HEAD(&dirty_fs_roots); 243d6e4a428SChris Mason 24479154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 24579154b1bSChris Mason if (trans->transaction->in_commit) { 24679154b1bSChris Mason cur_trans = trans->transaction; 24779154b1bSChris Mason trans->transaction->use_count++; 24879154b1bSChris Mason btrfs_end_transaction(trans, root); 24979154b1bSChris Mason ret = wait_for_commit(root, cur_trans); 25079154b1bSChris Mason BUG_ON(ret); 25179154b1bSChris Mason put_transaction(cur_trans); 25279154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 25379154b1bSChris Mason return 0; 25479154b1bSChris Mason } 2552c90e5d6SChris Mason cur_trans = trans->transaction; 2562c90e5d6SChris Mason trans->transaction->in_commit = 1; 25779154b1bSChris Mason while (trans->transaction->num_writers > 1) { 2582c90e5d6SChris Mason WARN_ON(cur_trans != trans->transaction); 25979154b1bSChris Mason prepare_to_wait(&trans->transaction->writer_wait, &wait, 26079154b1bSChris Mason TASK_UNINTERRUPTIBLE); 26179154b1bSChris Mason if (trans->transaction->num_writers <= 1) 26279154b1bSChris Mason break; 26379154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 26479154b1bSChris Mason schedule(); 26579154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 2662c90e5d6SChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 26779154b1bSChris Mason } 26879154b1bSChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 2692c90e5d6SChris Mason WARN_ON(cur_trans != trans->transaction); 2700f7d52f4SChris Mason add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots); 27179154b1bSChris Mason ret = btrfs_commit_tree_roots(trans, root); 27279154b1bSChris Mason BUG_ON(ret); 27378fae27eSChris Mason cur_trans = root->fs_info->running_transaction; 27478fae27eSChris Mason root->fs_info->running_transaction = NULL; 2750f7d52f4SChris Mason btrfs_set_super_generation(root->fs_info->disk_super, 2760f7d52f4SChris Mason root->fs_info->generation + 1); 27778fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 27879154b1bSChris Mason ret = btrfs_write_and_wait_transaction(trans, root); 27979154b1bSChris Mason BUG_ON(ret); 28079154b1bSChris Mason 28179154b1bSChris Mason write_ctree_super(trans, root); 28278fae27eSChris Mason btrfs_finish_extent_commit(trans, root); 28378fae27eSChris Mason mutex_lock(&root->fs_info->trans_mutex); 2842c90e5d6SChris Mason cur_trans->commit_done = 1; 2852c90e5d6SChris Mason wake_up(&cur_trans->commit_wait); 28679154b1bSChris Mason put_transaction(cur_trans); 28778fae27eSChris Mason put_transaction(cur_trans); 28878fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 2892c90e5d6SChris Mason kmem_cache_free(btrfs_trans_handle_cachep, trans); 29079154b1bSChris Mason 2910f7d52f4SChris Mason drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots); 29279154b1bSChris Mason return ret; 29379154b1bSChris Mason } 29479154b1bSChris Mason 295