[dm-devel] [PATCH 10/14] libmultipath, multipathd: log failure setting sysfs attributes

[mwilck at suse.com]

From: Martin Wilck <mwilck at suse.com>

Failure to set a sysfs attribute is worth noting, normally.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 libmultipath/configure.c   | 18 +++++++++++++++---
 multipathd/fpin_handlers.c | 11 +++++++++--
 multipathd/main.c          | 38 +++++++++++++++++++++++++++++++-------
 3 files changed, 55 insertions(+), 12 deletions(-)

diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index 0607dba..4427f91 100644
--- a/libmultipath/configure.c
+++ b/libmultipath/configure.c
@@ -489,9 +489,15 @@ void trigger_partitions_udev_change(struct udev_device *dev,
 
 		devtype = udev_device_get_devtype(part);
 		if (devtype && !strcmp("partition", devtype)) {
+			ssize_t ret;
+
 			condlog(4, "%s: triggering %s event for %s", __func__,
 				action, syspath);
-			sysfs_attr_set_value(part, "uevent", action, len);
+			ret = sysfs_attr_set_value(part, "uevent", action, len);
+			if (ret != len)
+				log_sysfs_attr_set_value(2, ret,
+					"%s: failed to trigger %s uevent",
+					syspath, action);
 		}
 		udev_device_unref(part);
 	}
@@ -510,6 +516,7 @@ trigger_path_udev_change(struct path *pp, bool is_mpath)
 	 */
 	const char *action = is_mpath ? "change" : "add";
 	const char *env;
+	ssize_t len, ret;
 
 	if (!pp->udev)
 		return;
@@ -536,8 +543,13 @@ trigger_path_udev_change(struct path *pp, bool is_mpath)
 
 	condlog(3, "triggering %s uevent for %s (is %smultipath member)",
 		action, pp->dev, is_mpath ? "" : "no ");
-	sysfs_attr_set_value(pp->udev, "uevent",
-			     action, strlen(action));
+
+	len = strlen(action);
+	ret = sysfs_attr_set_value(pp->udev, "uevent", action, len);
+	if (ret != len)
+		log_sysfs_attr_set_value(2, ret,
+					 "%s: failed to trigger %s uevent",
+					 pp->dev, action);
 	trigger_partitions_udev_change(pp->udev, action,
 				       strlen(action));
 }
diff --git a/multipathd/fpin_handlers.c b/multipathd/fpin_handlers.c
index 384ae31..0019572 100644
--- a/multipathd/fpin_handlers.c
+++ b/multipathd/fpin_handlers.c
@@ -172,8 +172,15 @@ fpin_els_add_li_frame(struct fc_nl_event *fc_event)
 /*Sets the rport port_state to marginal*/
 static void fpin_set_rport_marginal(struct udev_device *rport_dev)
 {
-	sysfs_attr_set_value(rport_dev, "port_state",
-				"Marginal", strlen("Marginal"));
+	static const char marginal[] = "Marginal";
+	ssize_t ret;
+
+	ret = sysfs_attr_set_value(rport_dev, "port_state",
+				   marginal, sizeof(marginal) - 1);
+	if (ret != sizeof(marginal) - 1)
+		log_sysfs_attr_set_value(2, ret,
+					 "%s: failed to set port_state to marginal",
+					 udev_device_get_syspath(rport_dev));
 }
 
 /*Add the marginal devices info into the list*/
diff --git a/multipathd/main.c b/multipathd/main.c
index 68eca92..a160c82 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -911,14 +911,22 @@ rescan_path(struct udev_device *ud)
 {
 	ud = udev_device_get_parent_with_subsystem_devtype(ud, "scsi",
 							   "scsi_device");
-	if (ud)
-		sysfs_attr_set_value(ud, "rescan", "1", strlen("1"));
+	if (ud) {
+		ssize_t ret =
+			sysfs_attr_set_value(ud, "rescan", "1", strlen("1"));
+		if (ret != strlen("1"))
+			log_sysfs_attr_set_value(1, ret,
+						 "%s: failed to trigger rescan",
+						 udev_device_get_syspath(ud));
+	}
 }
 
 void
 handle_path_wwid_change(struct path *pp, struct vectors *vecs)
 {
 	struct udev_device *udd;
+	static const char add[] = "add";
+	ssize_t ret;
 
 	if (!pp || !pp->udev)
 		return;
@@ -929,8 +937,12 @@ handle_path_wwid_change(struct path *pp, struct vectors *vecs)
 		dm_fail_path(pp->mpp->alias, pp->dev_t);
 	}
 	rescan_path(udd);
-	sysfs_attr_set_value(udd, "uevent", "add", strlen("add"));
+	ret = sysfs_attr_set_value(udd, "uevent", add, sizeof(add) - 1);
 	udev_device_unref(udd);
+	if (ret != sizeof(add) - 1)
+		log_sysfs_attr_set_value(1, ret,
+					 "%s: failed to trigger add event",
+					 pp->dev);
 }
 
 bool
@@ -2003,9 +2015,14 @@ partial_retrigger_tick(vector pathvec)
 		    --pp->partial_retrigger_delay == 0) {
 			const char *msg = udev_device_get_is_initialized(pp->udev) ?
 					  "change" : "add";
+			ssize_t len = strlen(msg);
+			ssize_t ret = sysfs_attr_set_value(pp->udev, "uevent", msg,
+							   len);
 
-			sysfs_attr_set_value(pp->udev, "uevent", msg,
-					     strlen(msg));
+			if (len != ret)
+				log_sysfs_attr_set_value(2, ret,
+					"%s: failed to trigger %s event",
+					pp->dev, msg);
 		}
 	}
 }
@@ -2245,12 +2262,19 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks)
 
 	if (!pp->mpp && pp->initialized == INIT_MISSING_UDEV) {
 		if (pp->retriggers < retrigger_tries) {
+			static const char change[] = "change";
+			ssize_t ret;
+
 			condlog(2, "%s: triggering change event to reinitialize",
 				pp->dev);
 			pp->initialized = INIT_REQUESTED_UDEV;
 			pp->retriggers++;
-			sysfs_attr_set_value(pp->udev, "uevent", "change",
-					     strlen("change"));
+			ret = sysfs_attr_set_value(pp->udev, "uevent", change,
+						   sizeof(change) - 1);
+			if (ret != sizeof(change) - 1)
+				log_sysfs_attr_set_value(1, ret,
+							 "%s: failed to trigger change event",
+							 pp->dev);
 			return 0;
 		} else {
 			condlog(1, "%s: not initialized after %d udev retriggers",
-- 
2.36.1