New API: Implement set-uuid for ext2/3/4 and XFS (RHBZ#986877).

Also includes tests.

daemon/Makefile.am

@@ -168,6 +168,7 @@ guestfsd_SOURCES = \
 	upload.c \
 	utimens.c \
 	utsname.c \
+	uuids.c \
 	wc.c \
 	xattr.c \
 	xfs.c \

daemon/blkid.c

@@ -29,7 +29,7 @@
 
 GUESTFSD_EXT_CMD(str_blkid, blkid);
 
-static char *
+char *
 get_blkid_tag (const char *device, const char *tag)
 {
   char *out;

daemon/daemon.h

@@ -207,6 +207,9 @@ extern int sync_disks (void);
 #define EXT2_LABEL_MAX 16
 extern int fstype_is_extfs (const char *fstype);
 
+/*-- in blkid.c --*/
+extern char *get_blkid_tag (const char *device, const char *tag);
+
 /*-- in lvm.c --*/
 extern int lv_canonical (const char *device, char **ret);
 

daemon/uuids.c

@@ -0,0 +1,101 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2013 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "daemon.h"
+#include "actions.h"
+#include "optgroups.h"
+
+GUESTFSD_EXT_CMD(str_tune2fs, tune2fs);
+GUESTFSD_EXT_CMD(str_xfs_admin, xfs_admin);
+
+static int
+e2uuid (const char *device, const char *uuid)
+{
+  int r;
+  CLEANUP_FREE char *err = NULL;
+
+  /* Don't allow the magic values here.  If callers want to do this
+   * we'll add alternate set_uuid_* calls.
+   */
+  if (STREQ (uuid, "clear") || STREQ (uuid, "random") ||
+      STREQ (uuid, "time")) {
+    reply_with_error ("e2: invalid new UUID");
+    return -1;
+  }
+
+  r = command (NULL, &err, str_tune2fs, "-U", uuid, device, NULL);
+  if (r == -1) {
+    reply_with_error ("%s", err);
+    return -1;
+  }
+
+  return 0;
+}
+
+static int
+xfsuuid (const char *device, const char *uuid)
+{
+  int r;
+  CLEANUP_FREE char *err = NULL;
+
+  /* Don't allow special values. */
+  if (STREQ (uuid, "nil") || STREQ (uuid, "generate")) {
+    reply_with_error ("xfs: invalid new UUID");
+    return -1;
+  }
+
+  r = command (NULL, &err, str_xfs_admin, "-U", uuid, device, NULL);
+  if (r == -1) {
+    reply_with_error ("%s", err);
+    return -1;
+  }
+
+  return 0;
+}
+
+int
+do_set_uuid (const char *device, const char *uuid)
+{
+  int r;
+
+  /* How we set the UUID depends on the filesystem type. */
+  CLEANUP_FREE char *vfs_type = get_blkid_tag (device, "TYPE");
+  if (vfs_type == NULL)
+    return -1;
+
+  if (fstype_is_extfs (vfs_type))
+    r = e2uuid (device, uuid);
+
+  else if (STREQ (vfs_type, "xfs"))
+    r = xfsuuid (device, uuid);
+
+  else {
+    reply_with_error ("don't know how to set the UUID for '%s' filesystems",
+                      vfs_type);
+    r = -1;
+  }
+
+  return r;
+}

generator/actions.ml

@@ -4742,6 +4742,7 @@ C<device>." };
     name = "set_e2uuid";
     style = RErr, [Device "device"; String "uuid"], [];
     proc_nr = Some 82;
+    deprecated_by = Some "set_uuid";
     tests =
       (let uuid = uuidgen () in [
         InitBasicFS, Always, TestResultString (
@@ -4764,8 +4765,8 @@ C<device> to C<uuid>.  The format of the UUID and alternatives
 such as C<clear>, C<random> and C<time> are described in the
 L<tune2fs(8)> manpage.
 
-You can use either C<guestfs_tune2fs_l> or C<guestfs_get_e2uuid>
-to return the existing UUID of a filesystem." };
+You can use C<guestfs_vfs_uuid> to return the existing UUID
+of a filesystem." };
 
   { defaults with
     name = "get_e2uuid";
@@ -11338,6 +11339,24 @@ converting a readonly filesystem to be read-write, or vice-versa.
 Note that at the moment you must supply the \"optional\" C<rw>
 parameter.  In future we may allow other flags to be adjusted." };
 
+  { defaults with
+    name = "set_uuid";
+    style = RErr, [Device "device"; String "uuid"], [];
+    proc_nr = Some 403;
+    tests =
+      (let uuid = uuidgen () in [
+        InitBasicFS, Always, TestResultString (
+          [["set_uuid"; "/dev/sda1"; uuid];
+           ["vfs_uuid"; "/dev/sda1"]], uuid), [];
+      ]);
+    shortdesc = "set the filesystem UUID";
+    longdesc = "\
+Set the filesystem UIUD on C<device> to C<label>.
+
+Only some filesystem types support setting UUIDs.
+
+To read the UUID on a filesystem, call C<guestfs_vfs_uuid>." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.

po/POTFILES

@@ -92,6 +92,7 @@ daemon/umask.c
 daemon/upload.c
 daemon/utimens.c
 daemon/utsname.c
+daemon/uuids.c
 daemon/wc.c
 daemon/xattr.c
 daemon/xfs.c

src/MAX_PROC_NR

@@ -1 +1 @@
-402
+403

tests/xfs/test-xfs-misc.pl

@@ -46,5 +46,12 @@ my $label = $g->vfs_label ("/dev/sda1");
 die "unexpected label: expecting 'newlabel' but got '$label'"
     unless $label eq "newlabel";
 
+# Setting UUID.
+my $newuuid = "01234567-0123-0123-0123-0123456789ab";
+$g->set_uuid ("/dev/sda1", $newuuid);
+my $uuid = $g->vfs_uuid ("/dev/sda1");
+die "unexpected UUID: expecting '$newuuid' but got '$uuid'"
+    unless $uuid eq $newuuid;
+
 $g->shutdown ();
 $g->close ();