From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Wilck Subject: [PATCH 16/33] multipath: ignore -i if find_multipaths is set Date: Tue, 28 Feb 2017 17:23:12 +0100 Message-ID: <20170228162329.14517-17-mwilck@suse.com> References: <20170228162329.14517-1-mwilck@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170228162329.14517-1-mwilck@suse.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: dm-devel@redhat.com List-Id: dm-devel.ids multipath's logic for detecing new multipath devices with find_multipaths currently doesn't work reliably. If paths for a new device are added sequentially, the first one will be classified as non-multpath (and passed on to systemd for further processing) while subsequent ones will be seen as multipath devices. If the paths are added simultaneously (such as at udev trigger time after switching from the initrd to the rootfs, if device detection is already finished), whether or not additional paths will be seen when the udev rules for a given paths are processed is random. A proper implementation of this device detection would require some sort of information passing between multipathd and multipath, timeouts waiting for additional paths to appear when a single one is detected, retriggering of uevents if the status of a given paths changes, and more fine-grained treatment of "orphaned" paths in multipathd. All of that is currently non-existent. Currently, our only option is to rely on the wwids file for device setup with find_multipaths. In practice, that means that multipath maps will only be set up for such devices that have been set up manually by the user before. This is the behavior of multipath [-c|-u] without the "-i" option. But "-i" is useful for the !find_multipaths case, where the expectation is that all non-blacklisted devices are multipathed by default. Because we can't change the multipath invocation in the udev rules file depending on the find_multipaths setting, just ignore "-i" if find_multipaths is set. Signed-off-by: Martin Wilck --- multipath/main.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/multipath/main.c b/multipath/main.c index 8ce87a08..ed57135a 100644 --- a/multipath/main.c +++ b/multipath/main.c @@ -619,6 +619,16 @@ main (int argc, char *argv[]) } } + /* + * FIXME: new device detection with find_multipaths currently + * doesn't work reliably. + */ + if (cmd == CMD_VALID_PATH && + conf->find_multipaths && conf->ignore_wwids) { + condlog(2, "ignoring -i flag because find_multipath is set in multipath.conf"); + conf->ignore_wwids = 0; + } + if (getuid() != 0) { fprintf(stderr, "need to be root\n"); exit(1); -- 2.11.0