FIX: Verify if array name doesn't exist already

When e.g. array name (an) is correct and it is the same as container name (cn),
file element creation /dev/md/an will replace /dev/md/cn.
This can cause that user cannot access container using /dev/md/cn.

Verify during array creation if chosen name is not already existing
one.

[Changed to use map_by_name() rather than stat() to determine prior
 existence - NeilBrown]


Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 12 insertions, 0 deletions

diff --git a/Create.c b/Create.c
index 5d1548b2..90ff3edd 100644
--- a/Create.c
+++ b/Create.c
@@ -558,6 +558,18 @@ int Create(struct supertype *st, char *mddev,
 		map_unlock(&map);
 		return 1;
 	}
+	/* verify if chosen_name is not in use,
+	 * it could be in conflict with already existing device
+	 * e.g. container, array
+	 */
+	if (strncmp(chosen_name, "/dev/md/", 8) == 0
+	    && map_by_name(&map, chosen_name+8) != NULL) {
+		fprintf(stderr, Name ": Array name %s is in use already.\n",
+			chosen_name);
+		close(mdfd);
+		map_unlock(&map);
+		return 1;
+	}
 	mddev = chosen_name;
 
 	vers = md_get_version(mdfd);