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 779154b1bSChris Mason 879154b1bSChris Mason static void put_transaction(struct btrfs_transaction *transaction) 979154b1bSChris Mason { 1079154b1bSChris Mason transaction->use_count--; 1179154b1bSChris Mason if (transaction->use_count == 0) 1279154b1bSChris Mason kfree(transaction); 1379154b1bSChris Mason } 1479154b1bSChris Mason 1579154b1bSChris Mason static int join_transaction(struct btrfs_root *root) 1679154b1bSChris Mason { 1779154b1bSChris Mason struct btrfs_transaction *cur_trans; 1879154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 1979154b1bSChris Mason if (!cur_trans) { 2079154b1bSChris Mason cur_trans = kmalloc(sizeof(*cur_trans), GFP_NOFS); 2179154b1bSChris Mason BUG_ON(!cur_trans); 2279154b1bSChris Mason root->fs_info->running_transaction = cur_trans; 2379154b1bSChris Mason cur_trans->num_writers = 0; 2479154b1bSChris Mason cur_trans->transid = root->root_key.offset + 1; 2579154b1bSChris Mason init_waitqueue_head(&cur_trans->writer_wait); 2679154b1bSChris Mason init_waitqueue_head(&cur_trans->commit_wait); 2779154b1bSChris Mason cur_trans->in_commit = 0; 28d5719762SChris Mason cur_trans->use_count = 1; 2979154b1bSChris Mason cur_trans->commit_done = 0; 3079154b1bSChris Mason } 3179154b1bSChris Mason cur_trans->num_writers++; 3279154b1bSChris Mason return 0; 3379154b1bSChris Mason } 3479154b1bSChris Mason 3579154b1bSChris Mason struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 3679154b1bSChris Mason int num_blocks) 3779154b1bSChris Mason { 3879154b1bSChris Mason struct btrfs_trans_handle *h = kmalloc(sizeof(*h), GFP_NOFS); 3979154b1bSChris Mason int ret; 4079154b1bSChris Mason 4179154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 4279154b1bSChris Mason ret = join_transaction(root); 4379154b1bSChris Mason BUG_ON(ret); 4479154b1bSChris Mason h->transid = root->fs_info->running_transaction->transid; 4579154b1bSChris Mason h->transaction = root->fs_info->running_transaction; 4679154b1bSChris Mason h->blocks_reserved = num_blocks; 4779154b1bSChris Mason h->blocks_used = 0; 4879154b1bSChris Mason root->fs_info->running_transaction->use_count++; 4979154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 5079154b1bSChris Mason return h; 5179154b1bSChris Mason } 5279154b1bSChris Mason 5379154b1bSChris Mason int btrfs_end_transaction(struct btrfs_trans_handle *trans, 5479154b1bSChris Mason struct btrfs_root *root) 5579154b1bSChris Mason { 5679154b1bSChris Mason struct btrfs_transaction *cur_trans; 5779154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 5879154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 59d5719762SChris Mason WARN_ON(cur_trans->num_writers < 1); 6079154b1bSChris Mason if (waitqueue_active(&cur_trans->writer_wait)) 6179154b1bSChris Mason wake_up(&cur_trans->writer_wait); 6279154b1bSChris Mason cur_trans->num_writers--; 6379154b1bSChris Mason put_transaction(cur_trans); 6479154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 6579154b1bSChris Mason kfree(trans); 6679154b1bSChris Mason return 0; 6779154b1bSChris Mason } 6879154b1bSChris Mason 6979154b1bSChris Mason 7079154b1bSChris Mason int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, 7179154b1bSChris Mason struct btrfs_root *root) 7279154b1bSChris Mason { 7379154b1bSChris Mason filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping); 7479154b1bSChris Mason return 0; 7579154b1bSChris Mason } 7679154b1bSChris Mason 7779154b1bSChris Mason int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans, 7879154b1bSChris Mason struct btrfs_root *root) 7979154b1bSChris Mason { 8079154b1bSChris Mason int ret; 8179154b1bSChris Mason u64 old_extent_block; 8279154b1bSChris Mason struct btrfs_fs_info *fs_info = root->fs_info; 8379154b1bSChris Mason struct btrfs_root *tree_root = fs_info->tree_root; 8479154b1bSChris Mason struct btrfs_root *extent_root = fs_info->extent_root; 8579154b1bSChris Mason struct btrfs_root *inode_root = fs_info->inode_root; 8679154b1bSChris Mason 8779154b1bSChris Mason btrfs_set_root_blocknr(&inode_root->root_item, 8879154b1bSChris Mason inode_root->node->b_blocknr); 8979154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 9079154b1bSChris Mason &inode_root->root_key, 9179154b1bSChris Mason &inode_root->root_item); 9279154b1bSChris Mason BUG_ON(ret); 9379154b1bSChris Mason while(1) { 9479154b1bSChris Mason old_extent_block = btrfs_root_blocknr(&extent_root->root_item); 9579154b1bSChris Mason if (old_extent_block == extent_root->node->b_blocknr) 9679154b1bSChris Mason break; 9779154b1bSChris Mason btrfs_set_root_blocknr(&extent_root->root_item, 9879154b1bSChris Mason extent_root->node->b_blocknr); 9979154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 10079154b1bSChris Mason &extent_root->root_key, 10179154b1bSChris Mason &extent_root->root_item); 10279154b1bSChris Mason BUG_ON(ret); 10379154b1bSChris Mason } 10479154b1bSChris Mason return 0; 10579154b1bSChris Mason } 10679154b1bSChris Mason 10779154b1bSChris Mason static int wait_for_commit(struct btrfs_root *root, 10879154b1bSChris Mason struct btrfs_transaction *commit) 10979154b1bSChris Mason { 11079154b1bSChris Mason DEFINE_WAIT(wait); 11179154b1bSChris Mason commit->use_count++; 11279154b1bSChris Mason while(!commit->commit_done) { 11379154b1bSChris Mason prepare_to_wait(&commit->commit_wait, &wait, 11479154b1bSChris Mason TASK_UNINTERRUPTIBLE); 11579154b1bSChris Mason if (commit->commit_done) 11679154b1bSChris Mason break; 11779154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 11879154b1bSChris Mason schedule(); 11979154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 12079154b1bSChris Mason } 12179154b1bSChris Mason finish_wait(&commit->commit_wait, &wait); 12279154b1bSChris Mason return 0; 12379154b1bSChris Mason } 12479154b1bSChris Mason 12579154b1bSChris Mason int btrfs_commit_transaction(struct btrfs_trans_handle *trans, 12679154b1bSChris Mason struct btrfs_root *root) 12779154b1bSChris Mason { 12879154b1bSChris Mason int ret = 0; 12979154b1bSChris Mason struct buffer_head *snap = root->commit_root; 13079154b1bSChris Mason struct btrfs_key snap_key; 13179154b1bSChris Mason struct btrfs_transaction *cur_trans; 13279154b1bSChris Mason DEFINE_WAIT(wait); 13379154b1bSChris Mason 13479154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 13579154b1bSChris Mason if (trans->transaction->in_commit) { 13679154b1bSChris Mason cur_trans = trans->transaction; 13779154b1bSChris Mason trans->transaction->use_count++; 13879154b1bSChris Mason btrfs_end_transaction(trans, root); 13979154b1bSChris Mason ret = wait_for_commit(root, cur_trans); 14079154b1bSChris Mason BUG_ON(ret); 14179154b1bSChris Mason put_transaction(cur_trans); 14279154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 14379154b1bSChris Mason return 0; 14479154b1bSChris Mason } 14579154b1bSChris Mason while (trans->transaction->num_writers > 1) { 14679154b1bSChris Mason prepare_to_wait(&trans->transaction->writer_wait, &wait, 14779154b1bSChris Mason TASK_UNINTERRUPTIBLE); 14879154b1bSChris Mason if (trans->transaction->num_writers <= 1) 14979154b1bSChris Mason break; 15079154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 15179154b1bSChris Mason schedule(); 15279154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 15379154b1bSChris Mason } 15479154b1bSChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 15579154b1bSChris Mason 15679154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 15779154b1bSChris Mason root->fs_info->running_transaction = NULL; 15879154b1bSChris Mason 159d5719762SChris Mason if (root->node != root->commit_root) { 16079154b1bSChris Mason memcpy(&snap_key, &root->root_key, sizeof(snap_key)); 16179154b1bSChris Mason root->root_key.offset++; 162d5719762SChris Mason } 163d5719762SChris Mason 164d5719762SChris Mason mutex_unlock(&root->fs_info->trans_mutex); 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 17679154b1bSChris Mason ret = btrfs_write_and_wait_transaction(trans, root); 17779154b1bSChris Mason BUG_ON(ret); 17879154b1bSChris Mason 17979154b1bSChris Mason write_ctree_super(trans, root); 18079154b1bSChris Mason btrfs_finish_extent_commit(trans, root->fs_info->extent_root); 18179154b1bSChris Mason btrfs_finish_extent_commit(trans, root->fs_info->tree_root); 18279154b1bSChris Mason put_transaction(cur_trans); 18379154b1bSChris Mason kfree(trans); 18479154b1bSChris Mason 18579154b1bSChris Mason if (root->node != root->commit_root) { 18679154b1bSChris Mason trans = btrfs_start_transaction(root, 1); 18779154b1bSChris Mason root->commit_root = root->node; 18879154b1bSChris Mason get_bh(root->node); 18979154b1bSChris Mason ret = btrfs_drop_snapshot(trans, root, snap); 19079154b1bSChris Mason BUG_ON(ret); 19179154b1bSChris Mason 19279154b1bSChris Mason ret = btrfs_del_root(trans, root->fs_info->tree_root, 19379154b1bSChris Mason &snap_key); 19479154b1bSChris Mason BUG_ON(ret); 19579154b1bSChris Mason root->fs_info->generation = root->root_key.offset + 1; 19679154b1bSChris Mason ret = btrfs_end_transaction(trans, root); 19779154b1bSChris Mason BUG_ON(ret); 19879154b1bSChris Mason } 19979154b1bSChris Mason 20079154b1bSChris Mason return ret; 20179154b1bSChris Mason } 20279154b1bSChris Mason 203