xen/blkback: don't use xen_blkif_get() in xen-blkback kthread
authorJuergen Gross <jgross@suse.com>
Thu, 18 May 2017 15:28:49 +0000 (17:28 +0200)
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tue, 13 Jun 2017 20:27:39 +0000 (16:27 -0400)
commita24fa22ce22ae302b3bf8f7008896d52d5d57b8d
tree06c125fb23f5bd7b61f10d0d21110b8ed7ebccca
parent71df1d7ccad1c36f7321d6b3b48f2ea42681c363
xen/blkback: don't use xen_blkif_get() in xen-blkback kthread

There is no need to use xen_blkif_get()/xen_blkif_put() in the kthread
of xen-blkback. Thread stopping is synchronous and using the blkif
reference counting in the kthread will avoid to ever let the reference
count drop to zero at the end of an I/O running concurrent to
disconnecting and multiple rings.

Setting ring->xenblkd to NULL after stopping the kthread isn't needed
as the kthread does this already.

Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Steven Haigh <netwiz@crc.id.au>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
drivers/block/xen-blkback/blkback.c
drivers/block/xen-blkback/xenbus.c