[PATCH v2 08/18] multipathd: print extra default reply msg for busy devices

[Benjamin Marzinski <bmarzins@xxxxxxxxxx>]

If removing a multipath device fails because the device is in use,
return DM_FLUSH_BUSY from remove_functions, which causes cli_del_map()
to return -EBUSY, which will now print extra information in
default_reply().

Reviewed-by: Martin Wilck <mwilck@xxxxxxxx>
Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
---
 libmultipath/devmapper.c  | 14 +++++++-------
 libmultipath/devmapper.h  |  1 +
 multipathd/cli_handlers.c |  9 ++++++++-
 multipathd/uxlsnr.c       |  3 +++
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index 73bb6fe7..6bbe784d 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -1083,7 +1083,7 @@ int _dm_flush_map (const char * mapname, int need_sync, int deferred_remove,
 	/* If you aren't doing a deferred remove, make sure that no
 	 * devices are in use */
 	if (!do_deferred(deferred_remove) && partmap_in_use(mapname, NULL))
-			return DM_FLUSH_FAIL;
+			return DM_FLUSH_BUSY;
 
 	if (need_suspend &&
 	    dm_get_map(mapname, &mapsize, &params) == DMP_OK &&
@@ -1097,12 +1097,12 @@ int _dm_flush_map (const char * mapname, int need_sync, int deferred_remove,
 	free(params);
 	params = NULL;
 
-	if (dm_remove_partmaps(mapname, need_sync, deferred_remove))
-		return DM_FLUSH_FAIL;
+	if ((r = dm_remove_partmaps(mapname, need_sync, deferred_remove)))
+		return r;
 
 	if (!do_deferred(deferred_remove) && dm_get_opencount(mapname)) {
 		condlog(2, "%s: map in use", mapname);
-		return DM_FLUSH_FAIL;
+		return DM_FLUSH_BUSY;
 	}
 
 	do {
@@ -1506,7 +1506,7 @@ do_foreach_partmaps (const char * mapname,
 		    (p = strstr(params, dev_t)) &&
 		    !isdigit(*(p + strlen(dev_t)))
 		   ) {
-			if (partmap_func(names->name, data) != 0)
+			if ((r = partmap_func(names->name, data)) != 0)
 				goto out;
 		}
 
@@ -1538,12 +1538,12 @@ remove_partmap(const char *name, void *data)
 		if (!do_deferred(rd->deferred_remove) &&
 		    dm_get_opencount(name)) {
 			condlog(2, "%s: map in use", name);
-			return 1;
+			return DM_FLUSH_BUSY;
 		}
 	}
 	condlog(4, "partition map %s removed", name);
 	dm_device_remove(name, rd->need_sync, rd->deferred_remove);
-	return 0;
+	return DM_FLUSH_OK;
 }
 
 static int
diff --git a/libmultipath/devmapper.h b/libmultipath/devmapper.h
index 3fc8473b..fa9c6114 100644
--- a/libmultipath/devmapper.h
+++ b/libmultipath/devmapper.h
@@ -53,6 +53,7 @@ enum {
 	DM_FLUSH_OK = 0,
 	DM_FLUSH_FAIL,
 	DM_FLUSH_DEFERRED,
+	DM_FLUSH_BUSY,
 };
 
 int _dm_flush_map (const char *, int, int, int, int);
diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
index 9a0cd065..b49bc73a 100644
--- a/multipathd/cli_handlers.c
+++ b/multipathd/cli_handlers.c
@@ -31,6 +31,7 @@
 #include "foreign.h"
 #include "strbuf.h"
 #include "cli_handlers.h"
+#include "devmapper.h"
 
 static int
 show_paths (struct strbuf *reply, struct vectors *vecs, char *style, int pretty)
@@ -743,6 +744,7 @@ cli_del_map (void * v, struct strbuf *reply, void * data)
 	struct vectors * vecs = (struct vectors *)data;
 	char * param = get_keyparam(v, KEY_MAP);
 	struct multipath *mpp;
+	int r;
 
 	param = convert_dev(param, 0);
 	condlog(2, "%s: remove map (operator)", param);
@@ -752,7 +754,12 @@ cli_del_map (void * v, struct strbuf *reply, void * data)
 	if (!mpp)
 		return 1;
 
-	return flush_map(mpp, vecs);
+	r = flush_map(mpp, vecs);
+	if (r == DM_FLUSH_OK)
+		return 0;
+	else if (r == DM_FLUSH_BUSY)
+		return -EBUSY;
+	return 1;
 }
 
 static int
diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c
index 4df01666..707ed396 100644
--- a/multipathd/uxlsnr.c
+++ b/multipathd/uxlsnr.c
@@ -411,6 +411,9 @@ void default_reply(struct client *c, int r)
 	case -ETIMEDOUT:
 		append_strbuf_str(&c->reply, "timeout\n");
 		break;
+	case -EBUSY:
+		append_strbuf_str(&c->reply, "map or partition in use\n");
+		break;
 	}
 }
 
-- 
2.43.0