In other words, alua_rtpg_queue() must hold an sdev reference and a pg
reference before queueing rtpg work. If no rtpg work is queued no
additional references should be held when alua_rtpg_queue() returns. If
no rtpg work is queued, ensure that alua_rtpg_queue() only gives up the
sdev reference if that reference was obtained by the same
alua_rtpg_queue() call.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reported-by: Tang Junhui <tang.junhui@zte.com.cn> Cc: Hannes Reinecke <hare@suse.com> Cc: Tang Junhui <tang.junhui@zte.com.cn> Cc: <stable@vger.kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>