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 112c90e5d6SChris Mason #define TRANS_MAGIC 0xE1E10E 1279154b1bSChris Mason static void put_transaction(struct btrfs_transaction *transaction) 1379154b1bSChris Mason { 142c90e5d6SChris Mason WARN_ON(transaction->use_count == 0); 1579154b1bSChris Mason transaction->use_count--; 162c90e5d6SChris Mason WARN_ON(transaction->magic != TRANS_MAGIC); 1778fae27eSChris Mason if (transaction->use_count == 0) { 1878fae27eSChris Mason WARN_ON(total_trans == 0); 1978fae27eSChris Mason total_trans--; 202c90e5d6SChris Mason memset(transaction, 0, sizeof(*transaction)); 212c90e5d6SChris Mason kmem_cache_free(btrfs_transaction_cachep, transaction); 2279154b1bSChris Mason } 2378fae27eSChris Mason } 2479154b1bSChris Mason 2579154b1bSChris Mason static int join_transaction(struct btrfs_root *root) 2679154b1bSChris Mason { 2779154b1bSChris Mason struct btrfs_transaction *cur_trans; 2879154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 2979154b1bSChris Mason if (!cur_trans) { 302c90e5d6SChris Mason cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, 312c90e5d6SChris Mason GFP_NOFS); 3278fae27eSChris Mason total_trans++; 3379154b1bSChris Mason BUG_ON(!cur_trans); 3479154b1bSChris Mason root->fs_info->running_transaction = cur_trans; 3579154b1bSChris Mason cur_trans->num_writers = 0; 3679154b1bSChris Mason cur_trans->transid = root->root_key.offset + 1; 3779154b1bSChris Mason init_waitqueue_head(&cur_trans->writer_wait); 3879154b1bSChris Mason init_waitqueue_head(&cur_trans->commit_wait); 392c90e5d6SChris Mason cur_trans->magic = TRANS_MAGIC; 4079154b1bSChris Mason cur_trans->in_commit = 0; 41d5719762SChris Mason cur_trans->use_count = 1; 4279154b1bSChris Mason cur_trans->commit_done = 0; 4379154b1bSChris Mason } 4479154b1bSChris Mason cur_trans->num_writers++; 4579154b1bSChris Mason return 0; 4679154b1bSChris Mason } 4779154b1bSChris Mason 4879154b1bSChris Mason struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 4979154b1bSChris Mason int num_blocks) 5079154b1bSChris Mason { 512c90e5d6SChris Mason struct btrfs_trans_handle *h = 522c90e5d6SChris Mason kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); 5379154b1bSChris Mason int ret; 5479154b1bSChris Mason 5579154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 5679154b1bSChris Mason ret = join_transaction(root); 5779154b1bSChris Mason BUG_ON(ret); 5879154b1bSChris Mason h->transid = root->fs_info->running_transaction->transid; 5979154b1bSChris Mason h->transaction = root->fs_info->running_transaction; 6079154b1bSChris Mason h->blocks_reserved = num_blocks; 6179154b1bSChris Mason h->blocks_used = 0; 6279154b1bSChris Mason root->fs_info->running_transaction->use_count++; 6379154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 642c90e5d6SChris Mason h->magic = h->magic2 = TRANS_MAGIC; 6579154b1bSChris Mason return h; 6679154b1bSChris Mason } 6779154b1bSChris Mason 6879154b1bSChris Mason int btrfs_end_transaction(struct btrfs_trans_handle *trans, 6979154b1bSChris Mason struct btrfs_root *root) 7079154b1bSChris Mason { 7179154b1bSChris Mason struct btrfs_transaction *cur_trans; 722c90e5d6SChris Mason WARN_ON(trans->magic != TRANS_MAGIC); 732c90e5d6SChris Mason WARN_ON(trans->magic2 != TRANS_MAGIC); 7479154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 7579154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 76d5719762SChris Mason WARN_ON(cur_trans->num_writers < 1); 7779154b1bSChris Mason if (waitqueue_active(&cur_trans->writer_wait)) 7879154b1bSChris Mason wake_up(&cur_trans->writer_wait); 7979154b1bSChris Mason cur_trans->num_writers--; 8079154b1bSChris Mason put_transaction(cur_trans); 8179154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 82d6025579SChris Mason memset(trans, 0, sizeof(*trans)); 832c90e5d6SChris Mason kmem_cache_free(btrfs_trans_handle_cachep, trans); 8479154b1bSChris Mason return 0; 8579154b1bSChris Mason } 8679154b1bSChris Mason 8779154b1bSChris Mason 8879154b1bSChris Mason int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, 8979154b1bSChris Mason struct btrfs_root *root) 9079154b1bSChris Mason { 917cfcc17eSChris Mason filemap_write_and_wait(root->fs_info->btree_inode->i_mapping); 9279154b1bSChris Mason return 0; 9379154b1bSChris Mason } 9479154b1bSChris Mason 9579154b1bSChris Mason int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans, 9679154b1bSChris Mason struct btrfs_root *root) 9779154b1bSChris Mason { 9879154b1bSChris Mason int ret; 9979154b1bSChris Mason u64 old_extent_block; 10079154b1bSChris Mason struct btrfs_fs_info *fs_info = root->fs_info; 10179154b1bSChris Mason struct btrfs_root *tree_root = fs_info->tree_root; 10279154b1bSChris Mason struct btrfs_root *extent_root = fs_info->extent_root; 10379154b1bSChris Mason struct btrfs_root *inode_root = fs_info->inode_root; 10479154b1bSChris Mason 10579154b1bSChris Mason btrfs_set_root_blocknr(&inode_root->root_item, 10679154b1bSChris Mason inode_root->node->b_blocknr); 10779154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 10879154b1bSChris Mason &inode_root->root_key, 10979154b1bSChris Mason &inode_root->root_item); 11079154b1bSChris Mason BUG_ON(ret); 11179154b1bSChris Mason while(1) { 11279154b1bSChris Mason old_extent_block = btrfs_root_blocknr(&extent_root->root_item); 11379154b1bSChris Mason if (old_extent_block == extent_root->node->b_blocknr) 11479154b1bSChris Mason break; 11579154b1bSChris Mason btrfs_set_root_blocknr(&extent_root->root_item, 11679154b1bSChris Mason extent_root->node->b_blocknr); 11779154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 11879154b1bSChris Mason &extent_root->root_key, 11979154b1bSChris Mason &extent_root->root_item); 12079154b1bSChris Mason BUG_ON(ret); 12179154b1bSChris Mason } 12279154b1bSChris Mason return 0; 12379154b1bSChris Mason } 12479154b1bSChris Mason 12579154b1bSChris Mason static int wait_for_commit(struct btrfs_root *root, 12679154b1bSChris Mason struct btrfs_transaction *commit) 12779154b1bSChris Mason { 12879154b1bSChris Mason DEFINE_WAIT(wait); 12979154b1bSChris Mason while(!commit->commit_done) { 13079154b1bSChris Mason prepare_to_wait(&commit->commit_wait, &wait, 13179154b1bSChris Mason TASK_UNINTERRUPTIBLE); 13279154b1bSChris Mason if (commit->commit_done) 13379154b1bSChris Mason break; 13479154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 13579154b1bSChris Mason schedule(); 13679154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 13779154b1bSChris Mason } 13879154b1bSChris Mason finish_wait(&commit->commit_wait, &wait); 13979154b1bSChris Mason return 0; 14079154b1bSChris Mason } 14179154b1bSChris Mason 14279154b1bSChris Mason int btrfs_commit_transaction(struct btrfs_trans_handle *trans, 14379154b1bSChris Mason struct btrfs_root *root) 14479154b1bSChris Mason { 14579154b1bSChris Mason int ret = 0; 14678fae27eSChris Mason struct buffer_head *snap; 14779154b1bSChris Mason struct btrfs_key snap_key; 14879154b1bSChris Mason struct btrfs_transaction *cur_trans; 14979154b1bSChris Mason DEFINE_WAIT(wait); 15079154b1bSChris Mason 15179154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 15279154b1bSChris Mason if (trans->transaction->in_commit) { 1532c90e5d6SChris Mason printk("already in commit!, waiting\n"); 15479154b1bSChris Mason cur_trans = trans->transaction; 15579154b1bSChris Mason trans->transaction->use_count++; 15679154b1bSChris Mason btrfs_end_transaction(trans, root); 15779154b1bSChris Mason ret = wait_for_commit(root, cur_trans); 15879154b1bSChris Mason BUG_ON(ret); 15979154b1bSChris Mason put_transaction(cur_trans); 16079154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 16179154b1bSChris Mason return 0; 16279154b1bSChris Mason } 1632c90e5d6SChris Mason cur_trans = trans->transaction; 1642c90e5d6SChris Mason trans->transaction->in_commit = 1; 16579154b1bSChris Mason while (trans->transaction->num_writers > 1) { 1662c90e5d6SChris Mason WARN_ON(cur_trans != trans->transaction); 16779154b1bSChris Mason prepare_to_wait(&trans->transaction->writer_wait, &wait, 16879154b1bSChris Mason TASK_UNINTERRUPTIBLE); 16979154b1bSChris Mason if (trans->transaction->num_writers <= 1) 17079154b1bSChris Mason break; 17179154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 17279154b1bSChris Mason schedule(); 17379154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 1742c90e5d6SChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 17579154b1bSChris Mason } 17679154b1bSChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 1772c90e5d6SChris Mason WARN_ON(cur_trans != trans->transaction); 178d5719762SChris Mason if (root->node != root->commit_root) { 17979154b1bSChris Mason memcpy(&snap_key, &root->root_key, sizeof(snap_key)); 18079154b1bSChris Mason root->root_key.offset++; 181d5719762SChris Mason } 182d5719762SChris Mason 18379154b1bSChris Mason if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) { 18479154b1bSChris Mason btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr); 18579154b1bSChris Mason ret = btrfs_insert_root(trans, root->fs_info->tree_root, 18679154b1bSChris Mason &root->root_key, &root->root_item); 18779154b1bSChris Mason BUG_ON(ret); 18879154b1bSChris Mason } 18979154b1bSChris Mason 19079154b1bSChris Mason ret = btrfs_commit_tree_roots(trans, root); 19179154b1bSChris Mason BUG_ON(ret); 19278fae27eSChris Mason cur_trans = root->fs_info->running_transaction; 19378fae27eSChris Mason root->fs_info->running_transaction = NULL; 19478fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 19579154b1bSChris Mason ret = btrfs_write_and_wait_transaction(trans, root); 19679154b1bSChris Mason BUG_ON(ret); 19779154b1bSChris Mason 19879154b1bSChris Mason write_ctree_super(trans, root); 19978fae27eSChris Mason btrfs_finish_extent_commit(trans, root); 20078fae27eSChris Mason mutex_lock(&root->fs_info->trans_mutex); 2012c90e5d6SChris Mason cur_trans->commit_done = 1; 2022c90e5d6SChris Mason wake_up(&cur_trans->commit_wait); 20379154b1bSChris Mason put_transaction(cur_trans); 20478fae27eSChris Mason put_transaction(cur_trans); 20578fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 2062c90e5d6SChris Mason kmem_cache_free(btrfs_trans_handle_cachep, trans); 20779154b1bSChris Mason if (root->node != root->commit_root) { 20879154b1bSChris Mason trans = btrfs_start_transaction(root, 1); 20978fae27eSChris Mason snap = root->commit_root; 21079154b1bSChris Mason root->commit_root = root->node; 21179154b1bSChris Mason get_bh(root->node); 21279154b1bSChris Mason ret = btrfs_drop_snapshot(trans, root, snap); 21379154b1bSChris Mason BUG_ON(ret); 21479154b1bSChris Mason 21579154b1bSChris Mason ret = btrfs_del_root(trans, root->fs_info->tree_root, 21679154b1bSChris Mason &snap_key); 21722b0ebdaSChris Mason BUG_ON(ret); 21822b0ebdaSChris Mason root->fs_info->generation = root->root_key.offset + 1; 21922b0ebdaSChris Mason ret = btrfs_end_transaction(trans, root); 22022b0ebdaSChris Mason BUG_ON(ret); 22179154b1bSChris Mason } 22279154b1bSChris Mason return ret; 22379154b1bSChris Mason } 22479154b1bSChris Mason 225