devices file: warn about missing multipath entry

Warn if a scsi device is listed in the devices file that
is used by a multipath device that is not listed.  This
will happen if a scsi device is listed in the devices
file and then an mpath device is set up to use it.

The way to correct this would be to remove the devices
file entry for the component device and add a new entry
for the multipath device.

1 files changed, 18 insertions, 1 deletions

diff --git a/lib/filters/filter-mpath.c b/lib/filters/filter-mpath.c
index 7644a5b0a..fc7cc51fa 100644
--- a/lib/filters/filter-mpath.c
+++ b/lib/filters/filter-mpath.c
@@ -15,6 +15,7 @@
 #include "base/memory/zalloc.h"
 #include "lib/misc/lib.h"
 #include "lib/filters/filter.h"
+#include "lib/device/device_id.h"
 
 #ifdef __linux__
 
@@ -22,11 +23,27 @@
 
 static int _ignore_mpath_component(struct cmd_context *cmd, struct dev_filter *f, struct device *dev, const char *use_filter_name)
 {
+	dev_t mpath_devno = 0;
+
 	dev->filtered_flags &= ~DEV_FILTERED_MPATH_COMPONENT;
 
-	if (dev_is_mpath_component(cmd, dev)) {
+	if (dev_is_mpath_component(cmd, dev, &mpath_devno)) {
 		log_debug_devs("%s: Skipping mpath component device", dev_name(dev));
 		dev->filtered_flags |= DEV_FILTERED_MPATH_COMPONENT;
+
+		/*
+		 * Warn about misconfig where an mpath component is
+		 * in the devices file, but its mpath device is not.
+		 */
+		if ((dev->flags & DEV_MATCHED_USE_ID) && mpath_devno) {
+			if (!get_du_for_devno(cmd, mpath_devno)) {
+				struct device *mpath_dev = dev_cache_get_by_devt(cmd, mpath_devno);
+				log_warn("WARNING: devices file is missing %s (%d:%d) using multipath component %s.",
+					 mpath_dev ? dev_name(mpath_dev) : "unknown",
+					 (int)MAJOR(mpath_devno), (int)MINOR(mpath_devno), dev_name(dev));
+			}
+		}
+
 		return 0;
 	}