rbdmap: unmap RBDMAPFILE images unless called with unmap-all

When called with a "map" parameter, the rbdmap script iterates the list
of images present in RBDMAPFILE (/etc/ceph/rbdmap), and maps each entry.
When called with "unmap", rbdmap currently iterates *all* mapped RBD
images and unmaps each one, regardless of whether it's listed in the
RBDMAPFILE or not.

This commit adds functionality such that only RBD images listed in the
configuration file are unmapped. This behaviour is the new default for
"rbdmap unmap". A new "unmap-all" parameter is added to offer the old
unmap-all-rbd-images behaviour, which is used by the systemd service.

Fixes: http://tracker.ceph.com/issues/18884

Signed-off-by: David Disseldorp <[email protected]>

src/rbdmap

@@ -1,15 +1,6 @@
 #!/bin/bash
 
 do_map() {
-
-        # default to reasonable value if RBDMAPFILE not set in environment
-        printenv RBDMAPFILE >/dev/null || local RBDMAPFILE=/etc/ceph/rbdmap
-
-	if [ ! -f "$RBDMAPFILE" ]; then
-		logger -p "daemon.warning" -t rbdmap "No $RBDMAPFILE found."
-		exit 0
-	fi
-
 	# Read /etc/rbdtab to create non-existant mapping
 	RET=0
 	while read DEV PARAMS; do
@@ -65,7 +56,33 @@ do_map() {
 
 }
 
-do_unmap() {
+unmount_unmap() {
+	local rbd_dev=$1
+	local mnt=$(findmnt --mtab --source ${rbd_dev} --noheadings \
+							| awk '{print $1'})
+
+	logger -p "daemon.debug" -t rbdmap "Unmapping '${rbd_dev}'"
+	if [ -n "${mnt}" ]; then
+	    logger -p "daemon.debug" -t rbdmap "Unmounting '${mnt}'"
+	    umount "${mnt}" >>/dev/null 2>&1
+	fi
+	if mountpoint -q "${mnt}"; then
+	    ## Un-mounting failed.
+	    logger -p "daemon.warning" -t rbdmap "Failed to unmount '${mnt}'"
+	    return 1
+	fi
+	## Un-mapping.
+	rbd unmap $rbd_dev >>/dev/null 2>&1
+	if [ $? -ne 0 ]; then
+	    logger -p "daemon.warning" -t rbdmap "Failed to unmap '${mnt}'"
+	    return 1
+	fi
+	logger -p "daemon.debug" -t rbdmap "Unmapped '${rbd_dev}'"
+
+	return 0
+}
+
+do_unmap_all() {
 	RET=0
 	## Unmount and unmap all rbd devices
 	if ls /dev/rbd[0-9]* >/dev/null 2>&1; then
@@ -81,31 +98,57 @@ do_unmap() {
 			    fi
 			done
 
-			logger -p "daemon.debug" -t rbdmap "Unmapping '${DEV}'"
-			MNT=$(findmnt --mtab --source ${DEV} --noheadings | awk '{print $1'})
-			if [ -n "${MNT}" ]; then
-			    logger -p "daemon.debug" -t rbdmap "Unmounting '${MNT}'"
-			    umount "${MNT}" >>/dev/null 2>&1
-			fi
-			if mountpoint -q "${MNT}"; then
-			    ## Un-mounting failed.
-			    logger -p "daemon.warning" -t rbdmap "Failed to unmount '${MNT}'"
-			    RET=$((${RET}+1))
-			    continue
-			fi
-			## Un-mapping.
-			rbd unmap $DEV >>/dev/null 2>&1
-			if [ $? -ne 0 ]; then
-			    logger -p "daemon.warning" -t rbdmap "Failed to unmap '${MNT}'"
-			    RET=$((${RET}+$?))
-			    continue
-			fi
-			logger -p "daemon.debug" -t rbdmap "Unmapped '${DEV}'"
+			unmount_unmap "$DEV" || RET=$((${RET}+$?))
+
 		done
 	fi
 	exit ${RET}
 }
 
+do_unmap() {
+	RET=0
+	## skip if nothing is mapped
+	ls /dev/rbd[0-9]* >/dev/null 2>&1 || exit ${RET}
+
+	# Read /etc/rbdtab to create non-existant mapping
+	while read DEV PARAMS; do
+		case "$DEV" in
+		  ""|\#*)
+			continue
+			;;
+		  */*)
+			;;
+		  *)
+			DEV=rbd/$DEV
+			;;
+		esac
+
+		MAP_RV="$(readlink -f /dev/rbd/$DEV)"
+		if [ ! -b $MAP_RV ]; then
+			logger -p "daemon.debug" -t rbdmap "$DEV not mapped, skipping unmap"
+			continue
+		fi
+
+		## pre-unmapping
+		if [ -x "/etc/ceph/rbd.d/${DEV}" ]; then
+			logger -p "daemon.debug" -t rbdmap "Running pre-unmap hook '/etc/ceph/rbd.d/${DEV}'"
+			/etc/ceph/rbd.d/${DEV} unmap "/dev/rbd/${DEV}"
+		fi
+
+		unmount_unmap "$MAP_RV" || RET=$((${RET}+$?))
+
+	done < $RBDMAPFILE
+	exit ${RET}
+}
+
+# default to reasonable value if RBDMAPFILE not set in environment
+RBDMAPFILE="${RBDMAPFILE:-/etc/ceph/rbdmap}"
+
+if [ ! -f "$RBDMAPFILE" ]; then
+	logger -p "daemon.warning" -t rbdmap "No $RBDMAPFILE found."
+	exit 0
+fi
+
 case "$1" in
   map)
 	do_map
@@ -114,6 +157,11 @@ case "$1" in
   unmap)
 	do_unmap
 	;;
+
+  unmap-all)
+	do_unmap_all
+	;;
+
   *)
-	echo "Usage: rbdmap map | unmap"
+	echo "Usage: rbdmap map | unmap | unmap-all"
 esac

systemd/rbdmap.service

@@ -11,7 +11,7 @@ Type=oneshot
 RemainAfterExit=yes
 ExecStart=/usr/bin/rbdmap map
 ExecReload=/usr/bin/rbdmap map
-ExecStop=/usr/bin/rbdmap unmap
+ExecStop=/usr/bin/rbdmap unmap-all
 
 [Install]
 WantedBy=multi-user.target