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authorJuergen Gross <jgross@suse.com>2017-05-18 18:28:49 +0300
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2017-06-13 23:27:39 +0300
commita24fa22ce22ae302b3bf8f7008896d52d5d57b8d (patch)
tree06c125fb23f5bd7b61f10d0d21110b8ed7ebccca /drivers/block
parent71df1d7ccad1c36f7321d6b3b48f2ea42681c363 (diff)
downloadlinux-a24fa22ce22ae302b3bf8f7008896d52d5d57b8d.tar.xz
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>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/xen-blkback/blkback.c3
-rw-r--r--drivers/block/xen-blkback/xenbus.c1
2 files changed, 0 insertions, 4 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 726c32e35db9..6b14c509f3c7 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -609,8 +609,6 @@ int xen_blkif_schedule(void *arg)
unsigned long timeout;
int ret;
- xen_blkif_get(blkif);
-
set_freezable();
while (!kthread_should_stop()) {
if (try_to_freeze())
@@ -665,7 +663,6 @@ purge_gnt_list:
print_stats(ring);
ring->xenblkd = NULL;
- xen_blkif_put(blkif);
return 0;
}
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 4cdf0490983e..792da683e70d 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -255,7 +255,6 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif)
if (ring->xenblkd) {
kthread_stop(ring->xenblkd);
wake_up(&ring->shutdown_wq);
- ring->xenblkd = NULL;
}
/* The above kthread_stop() guarantees that at this point we