fix RebuildMap() to retrieve 'subarray' info

RebuildMap falsely returns container info for member arrays.  Retrieving
the subarray and container_dev details prior to ->load_super() changes the
result from:

md127 imsm 082c6371:74b5ce03:64972e41:6b0860d5 /dev/md/imsm
md126 imsm 082c6371:74b5ce03:64972e41:6b0860d5 /dev/md/vol0

...to:

md126 /md127/0 3e03aee2:78c3c593:1e8ecaf0:eefb53ed /dev/md/vol0
md127 imsm 082c6371:74b5ce03:64972e41:6b0860d5 /dev/md/imsm

Reported-by: Ignacy Kasperowicz <ignacy.kasperowicz@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/mapfile.c b/mapfile.c
index 601c4ccf378b53ae185e326b45aa6f884be167e3..a3038be55bdd3264fb8589cee9a05ad73dc53b5f 100644 (file)
--- a/mapfile.c
+++ b/mapfile.c
@@ -297,6 +297,34 @@ struct map_ent *map_by_name(struct map_ent **map, char *name)
        return NULL;
 }
 
+/* sets the proper subarray and container_dev according to the metadata
+ * version super_by_fd does this automatically, this routine is meant as
+ * a supplement for guess_super()
+ */
+static void set_member_info(struct supertype *st, struct mdstat_ent *ent)
+{
+       char version[strlen(ent->metadata_version)+1];
+
+       st->subarray[0] = '\0';
+
+       if (strncmp(ent->metadata_version, "external:", 9) != 0)
+               return;
+
+       strcpy(version, ent->metadata_version);
+
+       if (is_subarray(&version[9])) {
+               char *subarray = strrchr(version, '/');
+               char *name = &version[10];
+
+               if (!subarray)
+                       return;
+               *subarray++ = '\0';
+
+               st->container_dev = devname2devnum(name);
+               strncpy(st->subarray, subarray, sizeof(st->subarray));
+       }
+}
+
 void RebuildMap(void)
 {
        struct mdstat_ent *mdstat = mdstat_read(0, 0);
@@ -337,8 +365,10 @@ void RebuildMap(void)
                        st = guess_super(dfd);
                        if ( st == NULL)
                                ok = -1;
-                       else
+                       else {
+                               set_member_info(st, md);
                                ok = st->ss->load_super(st, dfd, NULL);
+                       }
                        close(dfd);
                        if (ok != 0)
                                continue;