From 1fa11e265fa2562fb713171b6a58e72bb7afd276 Mon Sep 17 00:00:00 2001 From: Arne Jansen Date: Mon, 6 Aug 2012 14:18:51 -0600 Subject: Btrfs: fix deadlock in wait_for_more_refs Commit a168650c introduced a waiting mechanism to prevent busy waiting in btrfs_run_delayed_refs. This can deadlock with btrfs_run_ordered_operations, where a tree_mod_seq is held while waiting for the io to complete, while the end_io calls btrfs_run_delayed_refs. This whole mechanism is unnecessary. If not enough runnable refs are available to satisfy count, just return as count is more like a guideline than a strict requirement. In case we have to run all refs, commit transaction makes sure that no other threads are working in the transaction anymore, so we just assert here that no refs are blocked. Signed-off-by: Arne Jansen Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'fs/btrfs/ctree.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 9d7621f271f..08e0b11ba0a 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -420,12 +420,6 @@ void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, } spin_unlock(&fs_info->tree_mod_seq_lock); - /* - * we removed the lowest blocker from the blocker list, so there may be - * more processible delayed refs. - */ - wake_up(&fs_info->tree_mod_seq_wait); - /* * anything that's lower than the lowest existing (read: blocked) * sequence number can be removed from the tree. -- cgit v1.2.3-70-g09d2 From b12a3b1ea209d9dec02731fba58c3dbe7d31cfd8 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 7 Aug 2012 15:34:49 -0400 Subject: Btrfs: don't run __tree_mod_log_free_eb on leaves When we split a leaf, we may end up inserting a new root on top of that leaf. The reflog code was incorrectly assuming the old root was always a node. This makes sure we skip over leaves. Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/btrfs/ctree.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 08e0b11ba0a..6d183f60d63 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -625,6 +625,9 @@ __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) u32 nritems; int ret; + if (btrfs_header_level(eb) == 0) + return; + nritems = btrfs_header_nritems(eb); for (i = nritems - 1; i >= 0; i--) { ret = tree_mod_log_insert_key_locked(fs_info, eb, i, -- cgit v1.2.3-70-g09d2