Create: add error checking for 'write_init_super'.

[thirdparty/mdadm.git] / mdstat.c

diff --git a/mdstat.c b/mdstat.c
index c5a07b5ba9d651f8dec74d9acdf4d2168528541a..3d2edadb494dcad1a7db3528e493e60414741d8a 100644 (file)
--- a/mdstat.c
+++ b/mdstat.c
@@ -383,3 +383,36 @@ struct mdstat_ent *mdstat_by_component(char *name)
        }
        return NULL;
 }
+
+struct mdstat_ent *mdstat_by_subdev(char *subdev, int container)
+{
+       struct mdstat_ent *mdstat = mdstat_read(0, 0);
+
+       while (mdstat) {
+               struct mdstat_ent *ent;
+               char *pos;
+               /* metadata version must match:
+                *   external:[/-]md%d/%s
+                * where %d is 'container' and %s is 'subdev'
+                */
+               if (mdstat->metadata_version &&
+                   strncmp(mdstat->metadata_version, "external:", 9) == 0 &&
+                   strchr("/-", mdstat->metadata_version[9]) != NULL &&
+                   strncmp(mdstat->metadata_version+10, "md", 2) == 0 &&
+                   strtoul(mdstat->metadata_version+12, &pos, 10)
+                   == (unsigned)container &&
+                   pos > mdstat->metadata_version+12 &&
+                   *pos == '/' &&
+                   strcmp(pos+1, subdev) == 0
+                       ) {
+                       free_mdstat(mdstat->next);
+                       mdstat->next = NULL;
+                       return mdstat;
+               }
+               ent = mdstat;
+               mdstat = mdstat->next;
+               ent->next = NULL;
+               free_mdstat(ent);
+       }
+       return NULL;
+}