Free map to avoid resource leak issues

1. There are some places which didn't free map as
discovered by coverity.

CID 289661 (#1 of 1): Resource leak (RESOURCE_LEAK)12. leaked_storage: Variable mapl going out of scope leaks the storage it points to.
CID 289619 (#3 of 3): Resource leak (RESOURCE_LEAK)63. leaked_storage: Variable map going out of scope leaks the storage it points to.
CID 289618 (#1 of 1): Resource leak (RESOURCE_LEAK)26. leaked_storage: Variable map going out of scope leaks the storage it points to.
CID 289607 (#1 of 1): Resource leak (RESOURCE_LEAK)41. leaked_storage: Variable map going out of scope leaks the storage it points to.

2. If we call map_by_* inside a loop, then map_free
should be called in the same loop, and it is better
to set map to NULL after free.

3. And map_unlock is always called with map_lock,
if we don't call map_remove before map_unlock,
then the memory (allocated by  map_lock -> map_read
-> map_add -> xmalloc) could be leaked. So we
need to free it in map_unlock as well.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

Assemble.c

@@ -1851,8 +1851,8 @@ try_again:
 	if (rv == 1 && !pre_exist)
 		ioctl(mdfd, STOP_ARRAY, NULL);
 	free(devices);
-	map_unlock(&map);
 out:
+	map_unlock(&map);
 	if (rv == 0) {
 		wait_for(chosen_name, mdfd);
 		close(mdfd);

Detail.c

@@ -263,6 +263,7 @@ int Detail(char *dev, struct context *c)
 
 			if (st->ss->export_detail_super)
 				st->ss->export_detail_super(st);
+			map_free(map);
 		} else {
 			struct map_ent *mp, *map = NULL;
 			char nbuf[64];
@@ -277,6 +278,7 @@ int Detail(char *dev, struct context *c)
 				print_escape(mp->path+8);
 				putchar('\n');
 			}
+			map_free(map);
 		}
 		if (sra) {
 			struct mdinfo *mdi;

Incremental.c

@@ -1413,6 +1413,7 @@ restart:
 			sysfs_free(sra);
 		}
 	}
+	map_free(mapl);
 	return rv;
 }
 
@@ -1587,6 +1588,8 @@ static int Incremental_container(struct supertype *st, char *devname,
 
 		assemble_container_content(st, mdfd, ra, c,
 					   chosen_name, &result);
+		map_free(map);
+		map = NULL;
 		close(mdfd);
 	}
 	if (c->export && result) {
@@ -1663,6 +1666,7 @@ static int Incremental_container(struct supertype *st, char *devname,
 			close(sfd);
 	}
 	domain_free(domains);
+	map_free(map);
 	return 0;
 }
 

config.c

@@ -181,9 +181,10 @@ struct mddev_dev *load_containers(void)
 			}
 			d->next = rv;
 			rv = d;
+			map_free(map);
+			map = NULL;
 		}
 	free_mdstat(mdstat);
-	map_free(map);
 
 	return rv;
 }

mapfile.c

@@ -143,6 +143,8 @@ void map_unlock(struct map_ent **melp)
 		unlink(mapname[2]);
 		fclose(lf);
 	}
+	if (*melp)
+		map_free(*melp);
 	lf = NULL;
 }
 

mdadm.c

@@ -1885,6 +1885,8 @@ static int misc_scan(char devmode, struct context *c)
 			else
 				rv |= WaitClean(name, c->verbose);
 			put_md_name(name);
+			map_free(map);
+			map = NULL;
 		}
 	}
 	free_mdstat(ms);