tree 59dbb3bca55b7141ba0e0fda1031452ae87a6935
parent b52f75a595e8a70ee453bd6fb8023ee294f7a729
author Miao Xie <miaox@cn.fujitsu.com> 1321609380 +0800
committer David Sterba <dsterba@suse.cz> 1322675163 +0100

Btrfs: fix deadlock on metadata reservation when evicting a inode

When I ran the xfstests, I found the test tasks was blocked on meta-data
reservation.

By debugging, I found the reason of this bug:
   start transaction
        |
	v
   reserve meta-data space
	|
	v
   flush delay allocation -> iput inode -> evict inode
	^					|
	|					v
   wait for delay allocation flush <- reserve meta-data space

And besides that, the flush on evicting inode will block the thread, which
is reclaiming the memory, and make oom happen easily.

Fix this bug by skipping the flush step when evicting inode.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>