net/core: apply pm_runtime_set_memalloc_noio on network devices

Deadlock might be caused by allocating memory with GFP_KERNEL in
runtime_resume and runtime_suspend callback of network devices in iSCSI
situation, so mark network devices and its ancestor as 'memalloc_noio'
with the introduced pm_runtime_set_memalloc_noio().
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Decotigny <david.decotigny@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Jiri Kosina <jiri.kosina@suse.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

net/core/net-sysfs.c

@@ -21,6 +21,7 @@
 #include <linux/vmalloc.h>
 #include <linux/export.h>
 #include <linux/jiffies.h>
+#include <linux/pm_runtime.h>
 
 #include "net-sysfs.h"
 
@@ -1257,6 +1258,8 @@ void netdev_unregister_kobject(struct net_device * net)
 
 	remove_queue_kobjects(net);
 
+	pm_runtime_set_memalloc_noio(dev, false);
+
 	device_del(dev);
 }
 
@@ -1301,6 +1304,8 @@ int netdev_register_kobject(struct net_device *net)
 		return error;
 	}
 
+	pm_runtime_set_memalloc_noio(dev, true);
+
 	return error;
 }