Use --root instead of --aufs-root

When dumping Docker containers using the AUFS graph driver, we can
use the --root option instead of --aufs-root for specifying the
container's root.  This patch obviates the need for --aufs-root
and makes dump CLI more consistent with restore CLI.
Signed-off-by: Saied Kazemi <saied@google.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

crtools.c

@@ -172,7 +172,6 @@ int main(int argc, char *argv[])
 		{ "exec-cmd", no_argument, 0, 1059},
 		{ "manage-cgroups", no_argument, 0, 1060},
 		{ "cgroup-root", required_argument, 0, 1061},
-		{ "aufs-root", required_argument, 0, 1062},
 		{ },
 	};
 
@@ -401,9 +400,6 @@ int main(int argc, char *argv[])
 		case 'h':
 			usage_error = false;
 			goto usage;
-		case 1062:
-			opts.aufs_root = optarg;
-			break;
 		default:
 			goto usage;
 		}
@@ -556,9 +552,6 @@ usage:
 "     --exec-cmd         execute the command specified after '--' on successful\n"
 "                        restore making it the parent of the restored process\n"
 "\n"
-"* AUFS support (applicable to dump only):\n"
-"     --aufs-root        root pathname of the AUFS filesystem\n"
-"\n"
 "* Special resources support:\n"
 "  -x|--" USK_EXT_PARAM "      allow external unix connections\n"
 "     --" SK_EST_PARAM "  checkpoint/restore established TCP connections\n"

include/cr_options.h

@@ -61,7 +61,6 @@ struct cr_options {
 	char			*new_global_cg_root;
 	struct list_head	new_cgroup_roots;
 	bool			aufs;		/* auto-deteced, not via cli */
-	char			*aufs_root;
 };
 
 extern struct cr_options opts;

proc_parse.c

@@ -1742,25 +1742,12 @@ out:
  */
 int aufs_parse(struct mount_info *new)
 {
-	char *cp;
+	int ret = 0;
 
+	if (!strcmp(new->mountpoint, "./")) {
 		opts.aufs = true;
-
-	if (!opts.aufs_root || strcmp(new->mountpoint, "./"))
-		return 0;
-
-	cp = malloc(strlen(opts.aufs_root) + 1);
-	if (!cp) {
-		pr_err("Cannot allocate memory for %s\n", opts.aufs_root);
-		return -1;
+		ret = parse_aufs_branches(new);
 	}
-	strcpy(cp, opts.aufs_root);
 
-	pr_debug("Replacing %s with %s\n", new->root, opts.aufs_root);
-	free(new->root);
-	new->root = cp;
-
-	parse_aufs_branches(new);
-
-	return 0;
+	return ret;
 }

sysfs_parse.c

@@ -27,7 +27,7 @@
  * 90 61 0:33 / / rw,relatime - aufs none rw,si=4476a910a24617e6
  *
  * To handle this issue, the user has to specify the root of the AUFS
- * filesystem with the --aufs-root command line option.
+ * filesystem with the --root command line option.
  *
  * 2) /proc/<pid>/map_files: The symlinks are absolute pathnames of the
  * corresponding *physical* files in the branch they exist.  For example,
@@ -287,12 +287,12 @@ int fixup_aufs_vma_fd(struct vma_area *vma)
 		if (!vma->aufs_rpath)
 			return -1;
 		strcpy(vma->aufs_rpath, path);
-		if (opts.aufs_root) {
-			vma->aufs_fpath = xmalloc(strlen(opts.aufs_root) + 1 + len + 1);
+		if (opts.root) {
+			vma->aufs_fpath = xmalloc(strlen(opts.root) + 1 + len + 1);
 			if (!vma->aufs_fpath)
 				return -1;
 			/* skip ./ in path */
-			sprintf(vma->aufs_fpath, "%s/%s", opts.aufs_root, &path[2]);
+			sprintf(vma->aufs_fpath, "%s/%s", opts.root, &path[2]);
 		}
 		pr_debug("Saved AUFS paths %s and %s\n", vma->aufs_rpath, vma->aufs_fpath);
 	}