From 180591bcfed1a2cec048abb21d3dab840625caab Mon Sep 17 00:00:00 2001 From: Yan Zheng Date: Tue, 6 Jan 2009 09:58:06 -0500 Subject: [PATCH] Btrfs: Use btrfs_join_transaction to avoid deadlocks during snapshot creation Snapshot creation happens at a specific time during transaction commit. We need to make sure the code called by snapshot creation doesn't wait for the running transaction to commit. This changes btrfs_delete_inode and finish_pending_snaps to use btrfs_join_transaction instead of btrfs_start_transaction to avoid deadlocks. It would be better if btrfs_delete_inode didn't use the join, but the call path that triggers it is: btrfs_commit_transaction->create_pending_snapshots-> create_pending_snapshot->btrfs_lookup_dentry-> fixup_tree_root_location->btrfs_read_fs_root-> btrfs_read_fs_root_no_name->btrfs_orphan_cleanup->iput This will be fixed in a later patch by moving the orphan cleanup to the cleaner thread. Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 2 +- fs/btrfs/transaction.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 1b35ea63b6c..c0ca9c3723c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2886,7 +2886,7 @@ void btrfs_delete_inode(struct inode *inode) btrfs_wait_ordered_range(inode, 0, (u64)-1); btrfs_i_size_write(inode, 0); - trans = btrfs_start_transaction(root, 1); + trans = btrfs_join_transaction(root, 1); btrfs_set_trans_block_group(trans, inode); ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, 0); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 56ab1f5ea11..8a08f944334 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -800,7 +800,7 @@ static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info, parent_inode = pending->dentry->d_parent->d_inode; parent_root = BTRFS_I(parent_inode)->root; - trans = btrfs_start_transaction(parent_root, 1); + trans = btrfs_join_transaction(parent_root, 1); /* * insert the directory item