mdopen: use small sequence number for uniquifying array names.

Rather than appending the md minor number, we now append a small
sequence number to make sure name in /dev/md/ that aren't LOCAL are
unique.  As the map file is locked while we do this, we are sure
of no losing any races.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 15 insertions, 0 deletions

diff --git a/mapfile.c b/mapfile.c
index 1c2dc52..6169d52 100644
--- a/mapfile.c
+++ b/mapfile.c
@@ -245,3 +245,18 @@ struct map_ent *map_by_devnum(struct map_ent **map, int devnum)
 			return mp;
 	return NULL;
 }
+
+struct map_ent *map_by_name(struct map_ent **map, char *name)
+{
+	struct map_ent *mp;
+	if (!*map)
+		map_read(map);
+
+	for (mp = *map ; mp ; mp = mp->next) {
+		if (strncmp(mp->path, "/dev/md/", 8) != 0)
+			continue;
+		if (strcmp(mp->path+8, name) == 0)
+			return mp;
+	}
+	return NULL;
+}