From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Benjamin Marzinski" Subject: Re: [PATCH v4 10/11] libmultipath: don't try to set hwhandler if it is retained Date: Thu, 22 Jun 2017 14:09:56 -0500 Message-ID: <20170622190956.GO2940@octiron.msp.redhat.com> References: <20170622145913.23714-1-mwilck@suse.com> <20170622145913.23714-11-mwilck@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20170622145913.23714-11-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: Martin Wilck Cc: dm-devel@redhat.com, Xose Vazquez Perez List-Id: dm-devel.ids On Thu, Jun 22, 2017 at 04:59:12PM +0200, Martin Wilck wrote: > Setting a device handler only works if retain_attached_hw_handler > is 'no', or if the kernel didn't auto-assign a handler. If this > is not the case, don't even attempt to set a different handler. > > This requires reading the sysfs "dh_state" path attribute. > > Signed-off-by: Martin Wilck ACK -Ben > --- > libmultipath/configure.c | 8 +++++++- > libmultipath/propsel.c | 35 +++++++++++++++++++++++++++++++++++ > 2 files changed, 42 insertions(+), 1 deletion(-) > > diff --git a/libmultipath/configure.c b/libmultipath/configure.c > index 74b6f52a..03874f47 100644 > --- a/libmultipath/configure.c > +++ b/libmultipath/configure.c > @@ -275,15 +275,21 @@ int setup_map(struct multipath *mpp, char *params, int params_size) > > /* > * properties selectors > + * > + * Ordering matters for some properties: > + * - features after no_path_retry and retain_hwhandler > + * - hwhandler after retain_hwhandler > + * No guarantee that this list is complete, check code in > + * propsel.c if in doubt. > */ > conf = get_multipath_config(); > select_pgfailback(conf, mpp); > select_pgpolicy(conf, mpp); > select_selector(conf, mpp); > - select_hwhandler(conf, mpp); > select_no_path_retry(conf, mpp); > select_retain_hwhandler(conf, mpp); > select_features(conf, mpp); > + select_hwhandler(conf, mpp); > select_rr_weight(conf, mpp); > select_minio(conf, mpp); > select_mode(conf, mpp); > diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c > index d609394e..a86207a0 100644 > --- a/libmultipath/propsel.c > +++ b/libmultipath/propsel.c > @@ -19,8 +19,10 @@ > #include "discovery.h" > #include "dict.h" > #include "util.h" > +#include "sysfs.h" > #include "prioritizers/alua_rtpg.h" > #include > +#include > > pgpolicyfn *pgpolicies[] = { > NULL, > @@ -342,9 +344,42 @@ out: > return 0; > } > > +static int get_dh_state(struct path *pp, char *value, size_t value_len) > +{ > + struct udev_device *ud; > + > + if (pp->udev == NULL) > + return -1; > + > + ud = udev_device_get_parent_with_subsystem_devtype( > + pp->udev, "scsi", "scsi_device"); > + if (ud == NULL) > + return -1; > + > + return sysfs_attr_get_value(ud, "dh_state", value, value_len); > +} > + > int select_hwhandler(struct config *conf, struct multipath *mp) > { > char *origin; > + struct path *pp; > + /* dh_state is no longer than "detached" */ > + char handler[12]; > + char *dh_state; > + int i; > + > + dh_state = &handler[2]; > + if (mp->retain_hwhandler != RETAIN_HWHANDLER_OFF) { > + vector_foreach_slot(mp->paths, pp, i) { > + if (get_dh_state(pp, dh_state, sizeof(handler) - 2) > 0 > + && strcmp(dh_state, "detached")) { > + memcpy(handler, "1 ", 2); > + mp->hwhandler = handler; > + origin = "(setting: retained by kernel driver)"; > + goto out; > + } > + } > + } > > mp_set_hwe(hwhandler); > mp_set_conf(hwhandler); > -- > 2.13.1