GFS2: filesystem hang caused by incorrect lock order
authorBob Peterson <rpeterso@redhat.com>
Thu, 17 Mar 2011 20:19:58 +0000 (16:19 -0400)
committerSteven Whitehouse <swhiteho@redhat.com>
Mon, 18 Apr 2011 14:23:50 +0000 (15:23 +0100)
commit44ad37d69b2cc421d5b5c7ad7fed16230685b092
tree3632c63eef9e159947316f18d48054f082c0578e
parent001e8e8df4283dd4ef7a0297c012fce364c05cf1
GFS2: filesystem hang caused by incorrect lock order

This patch fixes a deadlock in GFS2 where two processes are trying
to reclaim an unlinked dinode:
One holds the inode glock and calls gfs2_lookup_by_inum trying to look
up the inode, which it can't, due to I_FREEING.  The other has set
I_FREEING from vfs and is at the beginning of gfs2_delete_inode
waiting for the glock, which is held by the first.  The solution is to
add a new non_block parameter to the gfs2_iget function that causes it
to return -ENOENT if the inode is being freed.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
fs/gfs2/dir.c
fs/gfs2/inode.c
fs/gfs2/inode.h
fs/gfs2/ops_fstype.c
fs/gfs2/rgrp.c
fs/gfs2/super.c