From f9295749388f82c8d2f485e99c72cd7c7876a99b Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 17 Jul 2008 12:54:14 -0400 Subject: [PATCH] btrfs_start_transaction: wait for commits in progress to finish btrfs_commit_transaction has to loop waiting for any writers in the transaction to finish before it can proceed. btrfs_start_transaction should be polite and not join a transaction that is in the process of being finished off. There are a few places that can't wait, basically the ones doing IO that might be needed to finish the transaction. For them, btrfs_join_transaction is added. Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 1 + fs/btrfs/file.c | 2 +- fs/btrfs/inode.c | 10 +++++----- fs/btrfs/transaction.c | 43 ++++++++++++++++++++++++++++++++++++++++--- fs/btrfs/transaction.h | 3 +++ 6 files changed, 51 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 4ddc8a8..acbce54 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -513,6 +513,7 @@ struct btrfs_fs_info { u64 alloc_start; struct btrfs_transaction *running_transaction; wait_queue_head_t transaction_throttle; + wait_queue_head_t transaction_wait; struct btrfs_super_block super_copy; struct btrfs_super_block super_for_commit; struct block_device *__bdev; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 66466d1..99bb385 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1291,6 +1291,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, mutex_init(&fs_info->cleaner_mutex); mutex_init(&fs_info->volume_mutex); init_waitqueue_head(&fs_info->transaction_throttle); + init_waitqueue_head(&fs_info->transaction_wait); #if 0 ret = add_hasher(fs_info, "crc32c"); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 3e4e5c2..d650589 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -251,7 +251,7 @@ static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans, end_of_last_block = start_pos + num_bytes - 1; lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS); - trans = btrfs_start_transaction(root, 1); + trans = btrfs_join_transaction(root, 1); if (!trans) { err = -ENOMEM; goto out_unlock; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index baf4601..0a68732 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -116,7 +116,7 @@ static int cow_file_range(struct inode *inode, u64 start, u64 end) struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; int ret = 0; - trans = btrfs_start_transaction(root, 1); + trans = btrfs_join_transaction(root, 1); BUG_ON(!trans); btrfs_set_trans_block_group(trans, inode); @@ -502,7 +502,7 @@ int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, return 0; } - trans = btrfs_start_transaction(root, 1); + trans = btrfs_join_transaction(root, 1); ordered_extent = btrfs_lookup_ordered_extent(inode, start); BUG_ON(!ordered_extent); @@ -1812,7 +1812,7 @@ int btrfs_write_inode(struct inode *inode, int wait) int ret = 0; if (wait) { - trans = btrfs_start_transaction(root, 1); + trans = btrfs_join_transaction(root, 1); btrfs_set_trans_block_group(trans, inode); ret = btrfs_commit_transaction(trans, root); } @@ -1830,7 +1830,7 @@ void btrfs_dirty_inode(struct inode *inode) struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; - trans = btrfs_start_transaction(root, 1); + trans = btrfs_join_transaction(root, 1); btrfs_set_trans_block_group(trans, inode); btrfs_update_inode(trans, root, inode); btrfs_end_transaction(trans, root); @@ -2395,7 +2395,7 @@ again: free_extent_map(em); em = NULL; btrfs_release_path(root, path); - trans = btrfs_start_transaction(root, 1); + trans = btrfs_join_transaction(root, 1); goto again; } write_extent_buffer(leaf, map + pg_offset, ptr, diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 86a5acc..0582390 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -62,6 +62,7 @@ static noinline int join_transaction(struct btrfs_root *root) init_waitqueue_head(&cur_trans->writer_wait); init_waitqueue_head(&cur_trans->commit_wait); cur_trans->in_commit = 0; + cur_trans->blocked = 0; cur_trans->use_count = 1; cur_trans->commit_done = 0; cur_trans->start_time = get_seconds(); @@ -99,14 +100,36 @@ static noinline int record_root_in_trans(struct btrfs_root *root) return 0; } -struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, - int num_blocks) +struct btrfs_trans_handle *start_transaction(struct btrfs_root *root, + int num_blocks, int join) { struct btrfs_trans_handle *h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); + struct btrfs_transaction *cur_trans; int ret; mutex_lock(&root->fs_info->trans_mutex); + cur_trans = root->fs_info->running_transaction; + if (cur_trans && cur_trans->blocked && !join) { + DEFINE_WAIT(wait); + cur_trans->use_count++; + while(1) { + prepare_to_wait(&root->fs_info->transaction_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (cur_trans->blocked) { + mutex_unlock(&root->fs_info->trans_mutex); + schedule(); + mutex_lock(&root->fs_info->trans_mutex); + finish_wait(&root->fs_info->transaction_wait, + &wait); + } else { + finish_wait(&root->fs_info->transaction_wait, + &wait); + break; + } + } + put_transaction(cur_trans); + } ret = join_transaction(root); BUG_ON(ret); @@ -123,6 +146,17 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, return h; } +struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, + int num_blocks) +{ + return start_transaction(root, num_blocks, 0); +} +struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root, + int num_blocks) +{ + return start_transaction(root, num_blocks, 1); +} + static noinline int wait_for_commit(struct btrfs_root *root, struct btrfs_transaction *commit) { @@ -156,7 +190,7 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, if (waitqueue_active(&cur_trans->writer_wait)) wake_up(&cur_trans->writer_wait); - if (cur_trans->in_commit && throttle) { + if (0 && cur_trans->in_commit && throttle) { DEFINE_WAIT(wait); mutex_unlock(&root->fs_info->trans_mutex); prepare_to_wait(&root->fs_info->transaction_throttle, &wait, @@ -617,6 +651,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, printk("commit trans %Lu\n", trans->transid); trans->transaction->in_commit = 1; + trans->transaction->blocked = 1; cur_trans = trans->transaction; if (cur_trans->list.prev != &root->fs_info->trans_list) { prev_trans = list_entry(cur_trans->list.prev, @@ -684,7 +719,9 @@ printk("commit trans %Lu\n", trans->transid); btrfs_copy_pinned(root, pinned_copy); + trans->transaction->blocked = 0; wake_up(&root->fs_info->transaction_throttle); + wake_up(&root->fs_info->transaction_wait); mutex_unlock(&root->fs_info->trans_mutex); ret = btrfs_write_and_wait_transaction(trans, root); diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 910350c..11fbdec 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -27,6 +27,7 @@ struct btrfs_transaction { int in_commit; int use_count; int commit_done; + int blocked; struct list_head list; struct extent_io_tree dirty_pages; unsigned long start_time; @@ -75,6 +76,8 @@ int btrfs_end_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root); struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, int num_blocks); +struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root, + int num_blocks); int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root); int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans, -- 2.7.4