Path: csiph.com!news.mixmin.net!aioe.org!news.servidellagleba.it!bofh.it!news.nic.it!robomod From: Ben Hutchings Newsgroups: linux.kernel Subject: [PATCH 3.16 045/306] dm mpath: check if path's request_queue is dying in activate_path() Date: Thu, 16 Feb 2017 01:10:02 +0100 Message-ID: References: X-Original-To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 X-Mailer: LinuxStableQueue (scripts by bwh) X-Sa-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-Sa-Exim-Mail-From: ben@decadent.org.uk X-Sa-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 39 Organization: linux.* mail to news gateway X-Original-Cc: akpm@linux-foundation.org, "Mike Snitzer" , "Bart Van Assche" X-Original-Date: Wed, 15 Feb 2017 22:41:40 +0000 X-Original-Message-ID: X-Original-References: X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1582082 3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mike Snitzer commit f10e06b744074824fb8ec7066bc03ecc90918f5b upstream. If pg_init_retries is set and a request is queued against a multipath device with all underlying block device request_queues in the "dying" state then an infinite loop is triggered because activate_path() never succeeds and hence never calls pg_init_done(). This change avoids that device removal triggers an infinite loop by failing the activate_path() which causes the "dying" path to be failed. Reported-by: Bart Van Assche Signed-off-by: Mike Snitzer Signed-off-by: Ben Hutchings --- drivers/md/dm-mpath.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -1196,10 +1196,10 @@ static void activate_path(struct work_st { struct pgpath *pgpath = container_of(work, struct pgpath, activate_path.work); + struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); - if (pgpath->is_active) - scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), - pg_init_done, pgpath); + if (pgpath->is_active && !blk_queue_dying(q)) + scsi_dh_activate(q, pg_init_done, pgpath); else pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED); }