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.
For internal consistency, this attribute must be updated after domap().
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
libmultipath/configure.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++-
libmultipath/discovery.c | 4 ++++
libmultipath/propsel.c | 15 ++++++++++++++
libmultipath/structs.h | 2 ++
4 files changed, 72 insertions(+), 1 deletion(-)
diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index 74b6f52a..55dbb261 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);
@@ -706,6 +712,48 @@ fail:
return 1;
}
+static void
+check_dh_state_changed(struct multipath *mp)
+{
+ struct config *conf;
+ struct path newp, *pp;
+ struct pathgroup *pg;
+ int i, j;
+
+ conf = get_multipath_config();
+
+ vector_foreach_slot (mp->pg, pg, j) {
+ vector_foreach_slot (pg->paths, pp, i) {
+ if (!pp->udev || !strlen(pp->dh_state) ||
+ (conf->retain_hwhandler == RETAIN_HWHANDLER_ON &&
+ strcmp(pp->dh_state, "detached")))
+ continue;
+
+ memset(&newp, 0, sizeof(newp));
+ memcpy(newp.dev, pp->dev, sizeof(newp.dev));
+ newp.udev = udev_device_ref(pp->udev);
+
+ if (pathinfo(&newp, conf, DI_SYSFS) == PATHINFO_OK) {
+ if (strncmp(newp.dh_state, pp->dh_state,
+ SCSI_DH_SIZE)) {
+ condlog(3, "%s: dh_state changed from %s to %s",
+ pp->dev,
+ pp->dh_state,
+ newp.dh_state);
+ memcpy(pp->dh_state, newp.dh_state,
+ SCSI_DH_SIZE);
+ }
+ } else
+ condlog(1, "%s: failed to update dh_state",
+ pp->dev);
+
+ udev_device_unref(newp.udev);
+ }
+ }
+
+ put_multipath_config(conf);
+}
+
/*
* Return value:
*/
@@ -828,6 +876,8 @@ int domap(struct multipath *mpp, char *params, int is_daemon)
}
}
dm_setgeometry(mpp);
+
+ check_dh_state_changed(mpp);
return DOMAP_OK;
}
return DOMAP_FAIL;
diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index 663c8eaa..8c0c6a9f 100644
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -1188,6 +1188,10 @@ scsi_sysfs_pathinfo (struct path * pp, vector hwtable)
condlog(3, "%s: tgt_node_name = %s",
pp->dev, pp->tgt_node_name);
+ if (sysfs_attr_get_value(parent, "dh_state",
+ pp->dh_state, sizeof(pp->dh_state)) >= 0)
+ condlog(3, "%s: dh_state = %s", pp->dev, pp->dh_state);
+
return 0;
}
diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index d609394e..d1b3d416 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -345,7 +345,22 @@ out:
int select_hwhandler(struct config *conf, struct multipath *mp)
{
char *origin;
+ struct path *pp;
+ char handler[SCSI_DH_SIZE+2];
+ int i;
+ if (mp->retain_hwhandler != RETAIN_HWHANDLER_OFF) {
+ vector_foreach_slot(mp->paths, pp, i) {
+ if (strlen(pp->dh_state) &&
+ strcmp(pp->dh_state, "detached")) {
+ snprintf(handler, sizeof(handler),
+ "1 %s", pp->dh_state);
+ mp->hwhandler = handler;
+ origin = "(setting: retained by kernel driver)";
+ goto out;
+ }
+ }
+ }
mp_set_hwe(hwhandler);
mp_set_conf(hwhandler);
mp_set_default(hwhandler, DEFAULT_HWHANDLER);
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index 8ea984d9..4203e2b0 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -22,6 +22,7 @@
#define SCSI_PRODUCT_SIZE 17
#define SCSI_REV_SIZE 5
#define SCSI_STATE_SIZE 19
+#define SCSI_DH_SIZE 9 /* must hold "detached" */
#define NO_PATH_RETRY_UNDEF 0
#define NO_PATH_RETRY_FAIL -1
@@ -205,6 +206,7 @@ struct path {
char rev[SCSI_REV_SIZE];
char serial[SERIAL_SIZE];
char tgt_node_name[NODE_NAME_SIZE];
+ char dh_state[SCSI_DH_SIZE];
unsigned long long size;
unsigned int checkint;
unsigned int tick;
--
2.13.1
--
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