From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Benjamin Marzinski <bmarzins@redhat.com>
Date: Tue, 16 Jun 2020 16:25:34 -0500
Subject: [PATCH] multipath: delegate flushing maps to multipathd

Since there can be problems with removing maps outside of multipathd,
multipath should attempt to delegate this command to multipathd.
However, multipathd doesn't attempt to suspend the device, in order
to avoid potential hangs. If delegating to multipathd fails, multipath
should try the remove itself.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 multipath/main.c      | 14 ++++++++++++++
 multipath/multipath.8 |  4 ++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/multipath/main.c b/multipath/main.c
index a2080029..612c6815 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -828,6 +828,20 @@ int delegate_to_multipathd(enum mpath_cmds cmd,
 	if (cmd == CMD_CREATE && conf->force_reload == FORCE_RELOAD_YES) {
 		p += snprintf(p, n, "reconfigure");
 	}
+	else if (cmd == CMD_FLUSH_ONE && dev && dev_type == DEV_DEVMAP) {
+		p += snprintf(p, n, "del map %s", dev);
+		/* multipathd doesn't try as hard, to avoid potentially
+		 * hanging. If it fails, retry with the regular multipath
+		 * command */
+		r = NOT_DELEGATED;
+	}
+	else if (cmd == CMD_FLUSH_ALL) {
+		p += snprintf(p, n, "del maps");
+		/* multipathd doesn't try as hard, to avoid potentially
+		 * hanging. If it fails, retry with the regular multipath
+		 * command */
+		r = NOT_DELEGATED;
+	}
 	/* Add other translations here */
 
 	if (strlen(command) == 0)
diff --git a/multipath/multipath.8 b/multipath/multipath.8
index 8befc45a..47a33f9b 100644
--- a/multipath/multipath.8
+++ b/multipath/multipath.8
@@ -125,11 +125,11 @@ the system.
 Other operation modes are chosen by using one of the following command line switches:
 .TP
 .B \-f
-Flush (remove) a multipath device map specified as parameter, if unused.
+Flush (remove) a multipath device map specified as parameter, if unused. This operation is delegated to the multipathd daemon if it's running.
 .
 .TP
 .B \-F
-Flush (remove) all unused multipath device maps.
+Flush (remove) all unused multipath device maps. This operation is delegated to the multipathd daemon if it's running.
 .
 .TP
 .B \-l
-- 
2.17.2