Must mutex_lock after dm_bufio_read, before dm_bufio_read error
handling, otherwise process_entry error path will return without
volume->read_threads_mutex held. This fixes potential double
mutex_unlock.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Susan LeGendre-McGhee <slegendr@redhat.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>