btrfs: Init io_lock after cloning btrfs device struct
authorThomas Gleixner <tglx@linutronix.de>
Wed, 20 Feb 2013 19:06:20 +0000 (14:06 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 14 Mar 2013 18:29:42 +0000 (11:29 -0700)
commitd0e44ede196b82c0448776b4b0c7c59989e3bea8
treec2a31136a2dd6435b51ab37a03e9738ffd61f26a
parenta5646410c2d80c4dd4692f5f6bc2fcdfc3aa557b
btrfs: Init io_lock after cloning btrfs device struct

commit 1cba0cdf5e4dbcd9e5fa5b54d7a028e55e2ca057 upstream.

__btrfs_close_devices() clones btrfs device structs with
memcpy(). Some of the fields in the clone are reinitialized, but it's
missing to init io_lock. In mainline this goes unnoticed, but on RT it
leaves the plist pointing to the original about to be freed lock
struct.

Initialize io_lock after cloning, so no references to the original
struct are left.

Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/btrfs/volumes.c