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; 879154b1bSChris Mason static void put_transaction(struct btrfs_transaction *transaction) 979154b1bSChris Mason { 1079154b1bSChris Mason transaction->use_count--; 1178fae27eSChris Mason if (transaction->use_count == 0) { 1278fae27eSChris Mason WARN_ON(total_trans == 0); 1378fae27eSChris Mason total_trans--; 1479154b1bSChris Mason kfree(transaction); 1579154b1bSChris Mason } 1678fae27eSChris Mason } 1779154b1bSChris Mason 1879154b1bSChris Mason static int join_transaction(struct btrfs_root *root) 1979154b1bSChris Mason { 2079154b1bSChris Mason struct btrfs_transaction *cur_trans; 2179154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 2279154b1bSChris Mason if (!cur_trans) { 2379154b1bSChris Mason cur_trans = kmalloc(sizeof(*cur_trans), GFP_NOFS); 2478fae27eSChris Mason total_trans++; 2579154b1bSChris Mason BUG_ON(!cur_trans); 2679154b1bSChris Mason root->fs_info->running_transaction = cur_trans; 2779154b1bSChris Mason cur_trans->num_writers = 0; 2879154b1bSChris Mason cur_trans->transid = root->root_key.offset + 1; 2979154b1bSChris Mason init_waitqueue_head(&cur_trans->writer_wait); 3079154b1bSChris Mason init_waitqueue_head(&cur_trans->commit_wait); 3179154b1bSChris Mason cur_trans->in_commit = 0; 32d5719762SChris Mason cur_trans->use_count = 1; 3379154b1bSChris Mason cur_trans->commit_done = 0; 3479154b1bSChris Mason } 3579154b1bSChris Mason cur_trans->num_writers++; 3679154b1bSChris Mason return 0; 3779154b1bSChris Mason } 3879154b1bSChris Mason 3979154b1bSChris Mason struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 4079154b1bSChris Mason int num_blocks) 4179154b1bSChris Mason { 4279154b1bSChris Mason struct btrfs_trans_handle *h = kmalloc(sizeof(*h), GFP_NOFS); 4379154b1bSChris Mason int ret; 4479154b1bSChris Mason 4579154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 4679154b1bSChris Mason ret = join_transaction(root); 4779154b1bSChris Mason BUG_ON(ret); 4879154b1bSChris Mason h->transid = root->fs_info->running_transaction->transid; 4979154b1bSChris Mason h->transaction = root->fs_info->running_transaction; 5079154b1bSChris Mason h->blocks_reserved = num_blocks; 5179154b1bSChris Mason h->blocks_used = 0; 5279154b1bSChris Mason root->fs_info->running_transaction->use_count++; 5379154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 5479154b1bSChris Mason return h; 5579154b1bSChris Mason } 5679154b1bSChris Mason 5779154b1bSChris Mason int btrfs_end_transaction(struct btrfs_trans_handle *trans, 5879154b1bSChris Mason struct btrfs_root *root) 5979154b1bSChris Mason { 6079154b1bSChris Mason struct btrfs_transaction *cur_trans; 6179154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 6279154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 63d5719762SChris Mason WARN_ON(cur_trans->num_writers < 1); 6479154b1bSChris Mason if (waitqueue_active(&cur_trans->writer_wait)) 6579154b1bSChris Mason wake_up(&cur_trans->writer_wait); 6679154b1bSChris Mason cur_trans->num_writers--; 6779154b1bSChris Mason put_transaction(cur_trans); 6879154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 69d6025579SChris Mason memset(trans, 0, sizeof(*trans)); 7079154b1bSChris Mason kfree(trans); 7179154b1bSChris Mason return 0; 7279154b1bSChris Mason } 7379154b1bSChris Mason 7479154b1bSChris Mason 7579154b1bSChris Mason int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, 7679154b1bSChris Mason struct btrfs_root *root) 7779154b1bSChris Mason { 78d98237b3SChris Mason filemap_write_and_wait(root->fs_info->btree_inode->i_mapping); 7979154b1bSChris Mason return 0; 8079154b1bSChris Mason } 8179154b1bSChris Mason 8279154b1bSChris Mason int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans, 8379154b1bSChris Mason struct btrfs_root *root) 8479154b1bSChris Mason { 8579154b1bSChris Mason int ret; 8679154b1bSChris Mason u64 old_extent_block; 8779154b1bSChris Mason struct btrfs_fs_info *fs_info = root->fs_info; 8879154b1bSChris Mason struct btrfs_root *tree_root = fs_info->tree_root; 8979154b1bSChris Mason struct btrfs_root *extent_root = fs_info->extent_root; 9079154b1bSChris Mason struct btrfs_root *inode_root = fs_info->inode_root; 9179154b1bSChris Mason 9279154b1bSChris Mason btrfs_set_root_blocknr(&inode_root->root_item, 9379154b1bSChris Mason inode_root->node->b_blocknr); 9479154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 9579154b1bSChris Mason &inode_root->root_key, 9679154b1bSChris Mason &inode_root->root_item); 9779154b1bSChris Mason BUG_ON(ret); 9879154b1bSChris Mason while(1) { 9979154b1bSChris Mason old_extent_block = btrfs_root_blocknr(&extent_root->root_item); 10079154b1bSChris Mason if (old_extent_block == extent_root->node->b_blocknr) 10179154b1bSChris Mason break; 10279154b1bSChris Mason btrfs_set_root_blocknr(&extent_root->root_item, 10379154b1bSChris Mason extent_root->node->b_blocknr); 10479154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 10579154b1bSChris Mason &extent_root->root_key, 10679154b1bSChris Mason &extent_root->root_item); 10779154b1bSChris Mason BUG_ON(ret); 10879154b1bSChris Mason } 10979154b1bSChris Mason return 0; 11079154b1bSChris Mason } 11179154b1bSChris Mason 11279154b1bSChris Mason static int wait_for_commit(struct btrfs_root *root, 11379154b1bSChris Mason struct btrfs_transaction *commit) 11479154b1bSChris Mason { 11579154b1bSChris Mason DEFINE_WAIT(wait); 11679154b1bSChris Mason while(!commit->commit_done) { 11779154b1bSChris Mason prepare_to_wait(&commit->commit_wait, &wait, 11879154b1bSChris Mason TASK_UNINTERRUPTIBLE); 11979154b1bSChris Mason if (commit->commit_done) 12079154b1bSChris Mason break; 12179154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 12279154b1bSChris Mason schedule(); 12379154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 12479154b1bSChris Mason } 12579154b1bSChris Mason finish_wait(&commit->commit_wait, &wait); 12679154b1bSChris Mason return 0; 12779154b1bSChris Mason } 12879154b1bSChris Mason 12979154b1bSChris Mason int btrfs_commit_transaction(struct btrfs_trans_handle *trans, 13079154b1bSChris Mason struct btrfs_root *root) 13179154b1bSChris Mason { 13279154b1bSChris Mason int ret = 0; 13378fae27eSChris Mason struct buffer_head *snap; 13479154b1bSChris Mason struct btrfs_key snap_key; 13579154b1bSChris Mason struct btrfs_transaction *cur_trans; 13679154b1bSChris Mason DEFINE_WAIT(wait); 13779154b1bSChris Mason 13879154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 13979154b1bSChris Mason if (trans->transaction->in_commit) { 14079154b1bSChris Mason cur_trans = trans->transaction; 14179154b1bSChris Mason trans->transaction->use_count++; 14279154b1bSChris Mason btrfs_end_transaction(trans, root); 14379154b1bSChris Mason ret = wait_for_commit(root, cur_trans); 14479154b1bSChris Mason BUG_ON(ret); 14579154b1bSChris Mason put_transaction(cur_trans); 14679154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 14779154b1bSChris Mason return 0; 14879154b1bSChris Mason } 14979154b1bSChris Mason while (trans->transaction->num_writers > 1) { 15079154b1bSChris Mason prepare_to_wait(&trans->transaction->writer_wait, &wait, 15179154b1bSChris Mason TASK_UNINTERRUPTIBLE); 15279154b1bSChris Mason if (trans->transaction->num_writers <= 1) 15379154b1bSChris Mason break; 15479154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 15579154b1bSChris Mason schedule(); 15679154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 15779154b1bSChris Mason } 15879154b1bSChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 15979154b1bSChris Mason 160d5719762SChris Mason if (root->node != root->commit_root) { 16179154b1bSChris Mason memcpy(&snap_key, &root->root_key, sizeof(snap_key)); 16279154b1bSChris Mason root->root_key.offset++; 163d5719762SChris Mason } 164d5719762SChris Mason 16579154b1bSChris Mason 16679154b1bSChris Mason if (btrfs_root_blocknr(&root->root_item) != root->node->b_blocknr) { 16779154b1bSChris Mason btrfs_set_root_blocknr(&root->root_item, root->node->b_blocknr); 16879154b1bSChris Mason ret = btrfs_insert_root(trans, root->fs_info->tree_root, 16979154b1bSChris Mason &root->root_key, &root->root_item); 17079154b1bSChris Mason BUG_ON(ret); 17179154b1bSChris Mason } 17279154b1bSChris Mason 17379154b1bSChris Mason ret = btrfs_commit_tree_roots(trans, root); 17479154b1bSChris Mason BUG_ON(ret); 17579154b1bSChris Mason 17678fae27eSChris Mason cur_trans = root->fs_info->running_transaction; 17778fae27eSChris Mason root->fs_info->running_transaction = NULL; 17878fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 17978fae27eSChris Mason 18079154b1bSChris Mason ret = btrfs_write_and_wait_transaction(trans, root); 18179154b1bSChris Mason BUG_ON(ret); 18279154b1bSChris Mason 18379154b1bSChris Mason write_ctree_super(trans, root); 18478fae27eSChris Mason btrfs_finish_extent_commit(trans, root); 18578fae27eSChris Mason mutex_lock(&root->fs_info->trans_mutex); 18679154b1bSChris Mason put_transaction(cur_trans); 18778fae27eSChris Mason put_transaction(cur_trans); 18878fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 18979154b1bSChris Mason kfree(trans); 19079154b1bSChris Mason 19179154b1bSChris Mason if (root->node != root->commit_root) { 19279154b1bSChris Mason trans = btrfs_start_transaction(root, 1); 19378fae27eSChris Mason snap = root->commit_root; 19479154b1bSChris Mason root->commit_root = root->node; 19579154b1bSChris Mason get_bh(root->node); 19679154b1bSChris Mason ret = btrfs_drop_snapshot(trans, root, snap); 19779154b1bSChris Mason BUG_ON(ret); 19879154b1bSChris Mason 19979154b1bSChris Mason ret = btrfs_del_root(trans, root->fs_info->tree_root, 20079154b1bSChris Mason &snap_key); 20122b0ebdaSChris Mason BUG_ON(ret); 20222b0ebdaSChris Mason root->fs_info->generation = root->root_key.offset + 1; 20322b0ebdaSChris Mason ret = btrfs_end_transaction(trans, root); 20422b0ebdaSChris Mason BUG_ON(ret); 20579154b1bSChris Mason } 20679154b1bSChris Mason 20779154b1bSChris Mason return ret; 20879154b1bSChris Mason } 20979154b1bSChris Mason 210