From: Josef Bacik <jbacik@fusionio.com>
Date: Wed, 17 Apr 2013 16:16:59 +0000 (-0400)
Subject: Btrfs: fix lockdep warning
X-Git-Tag: firefly_0821_release~3680^2~310^2~45
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=62dbd7176e196cd042c5542696981b268264fe92;p=firefly-linux-kernel-4.4.55.git

Btrfs: fix lockdep warning

The locking order for stuff is

__sb_start_write
ordered_mutex

but with sync() we don't do __sb_start_write for some strange reason, which
means that our iput in wait_ordered_extents could start a transaction which does
the __sb_start_write while we're holding the ordered_mutex.  Fix this by using
delayed iput in sync.  Thanks,

Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 5dc54ae5ac81..a4807ced23cc 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -866,7 +866,7 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
 		return 0;
 	}
 
-	btrfs_wait_ordered_extents(root, 0);
+	btrfs_wait_ordered_extents(root, 1);
 
 	trans = btrfs_attach_transaction_barrier(root);
 	if (IS_ERR(trans)) {