New API: set-label, for setting a label on any filesystem.

Currently only ext2/3/4 and (newly) NTFS are supported.

This change also deprecates set-e2label.

TODO

@@ -381,10 +381,6 @@ More ntfs tools
 ntfsprogs actually has a lot more useful tools than we currently
 use.  Interesting ones are:
 
-ntfslabel: display or change filesystem label (we should unify all
-  set*label APIs into a single set_vfs_label which can deal with any
-  filesystem)
-
 ntfscluster: display file(s) that occupy a cluster or sector
 
 ntfsinfo: print various information about NTFS volume and files

daemon/Makefile.am

@@ -125,6 +125,7 @@ guestfsd_SOURCES = \
 	inotify.c \
 	internal.c \
 	is.c \
+	labels.c \
 	link.c \
 	ls.c \
 	luks.c \

daemon/daemon.h

@@ -132,6 +132,9 @@ extern int sync_disks (void);
 /*-- in ext2.c --*/
 extern int e2prog (char *name); /* Massive hack for RHEL 5. */
 
+/* Confirmed this is true up to ext4 from the Linux sources. */
+#define EXT2_LABEL_MAX 16
+
 /*-- in lvm.c --*/
 extern int lv_canonical (const char *device, char **ret);
 

daemon/ext2.c

@@ -29,9 +29,6 @@
 #include "c-ctype.h"
 #include "actions.h"
 
-/* Confirmed this is true up to ext4 from the Linux sources. */
-#define EXT2_LABEL_MAX 16
-
 #define MAX_ARGS 64
 
 /* Choose which tools like mke2fs to use.  For RHEL 5 (only) there
@@ -154,28 +151,7 @@ do_tune2fs_l (const char *device)
 int
 do_set_e2label (const char *device, const char *label)
 {
-  int r;
-  char *err;
-
-  char prog[] = "e2label";
-  if (e2prog (prog) == -1)
-    return -1;
-
-  if (strlen (label) > EXT2_LABEL_MAX) {
-    reply_with_error ("%s: ext2 labels are limited to %d bytes",
-                      label, EXT2_LABEL_MAX);
-    return -1;
-  }
-
-  r = command (NULL, &err, prog, device, label, NULL);
-  if (r == -1) {
-    reply_with_error ("%s", err);
-    free (err);
-    return -1;
-  }
-
-  free (err);
-  return 0;
+  return do_set_label (device, label);
 }
 
 char *

daemon/labels.c

@@ -0,0 +1,100 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2012 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"
+
+static int
+e2label (const char *device, const char *label)
+{
+  int r;
+  char *err;
+
+  char prog[] = "e2label";
+  if (e2prog (prog) == -1)
+    return -1;
+
+  if (strlen (label) > EXT2_LABEL_MAX) {
+    reply_with_error ("%s: ext2 labels are limited to %d bytes",
+                      label, EXT2_LABEL_MAX);
+    return -1;
+  }
+
+  r = command (NULL, &err, prog, device, label, NULL);
+  if (r == -1) {
+    reply_with_error ("%s", err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+  return 0;
+}
+
+static int
+ntfslabel (const char *device, const char *label)
+{
+  int r;
+  char *err;
+
+  /* XXX We should check if the label is longer than 128 unicode
+   * characters and return an error.  This is not so easy since we
+   * don't have the required libraries.
+   */
+  r = command (NULL, &err, "ntfslabel", device, label, NULL);
+  if (r == -1) {
+    reply_with_error ("%s", err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+  return 0;
+}
+
+int
+do_set_label (const char *device, const char *label)
+{
+  char *vfs_type;
+
+  /* How we set the label depends on the filesystem type. */
+  vfs_type = do_vfs_type (device);
+  if (vfs_type == NULL)
+    return -1;
+
+  if (STREQ (vfs_type, "ext2") || STREQ (vfs_type, "ext3")
+      || STREQ (vfs_type, "ext4"))
+    return e2label (device, label);
+
+  else if (STREQ (vfs_type, "ntfs"))
+    return ntfslabel (device, label);
+
+  else {
+    reply_with_error ("don't know how to set the label for '%s' filesystems",
+                      vfs_type);
+    return -1;
+  }
+}

generator/generator_actions.ml

@@ -3007,7 +3007,7 @@ The implementation uses the C<pvremove> command which refuses to
 wipe physical volumes that contain any volume groups, so you have
 to remove those first.");
 
-  ("set_e2label", (RErr, [Device "device"; String "label"], []), 80, [],
+  ("set_e2label", (RErr, [Device "device"; String "label"], []), 80, [DeprecatedBy "set_label"],
    [InitBasicFS, Always, TestOutput (
       [["set_e2label"; "/dev/sda1"; "testlabel"];
        ["get_e2label"; "/dev/sda1"]], "testlabel")],
@@ -5698,7 +5698,7 @@ a file in the host and attach it as a device.");
 
   ("vfs_label", (RString "label", [Device "device"], []), 253, [],
    [InitBasicFS, Always, TestOutput (
-       [["set_e2label"; "/dev/sda1"; "LTEST"];
+       [["set_label"; "/dev/sda1"; "LTEST"];
         ["vfs_label"; "/dev/sda1"]], "LTEST")],
    "get the filesystem label",
    "\
@@ -6709,6 +6709,30 @@ Restore the C<backupfile> (from a previous call to
 C<guestfs_ntfsclone_out>) to C<device>, overwriting
 any existing contents of this device.");
 
+  ("set_label", (RErr, [Device "device"; String "label"], []), 310, [],
+   [InitBasicFS, Always, TestOutput (
+     [["set_label"; "/dev/sda1"; "testlabel"];
+      ["vfs_label"; "/dev/sda1"]], "testlabel");
+    InitPartition, IfAvailable "ntfs3g", TestOutput (
+     [["mkfs"; "ntfs"; "/dev/sda1"];
+      ["set_label"; "/dev/sda1"; "testlabel2"];
+      ["vfs_label"; "/dev/sda1"]], "testlabel2");
+    InitPartition, Always, TestLastFail (
+     [["zero"; "/dev/sda1"];
+      ["set_label"; "/dev/sda1"; "testlabel2"]])],
+   "set filesystem label",
+   "\
+Set the filesystem label on C<device> to C<label>.
+
+Only some filesystem types support labels, and libguestfs supports
+setting labels on only a subset of these.
+
+On ext2/3/4 filesystems, labels are limited to 16 bytes.
+
+On NTFS filesystems, labels are limited to 128 unicode characters.
+
+To read the label on a filesystem, call C<guestfs_vfs_label>.");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions

po/POTFILES.in

@@ -44,6 +44,7 @@ daemon/initrd.c
 daemon/inotify.c
 daemon/internal.c
 daemon/is.c
+daemon/labels.c
 daemon/link.c
 daemon/ls.c
 daemon/luks.c

src/MAX_PROC_NR

@@ -1 +1 @@
-309
+310

tests/guests/guest-aux/make-debian-img.sh

@@ -49,7 +49,7 @@ lvcreate home debian 32
 
 # Phony /boot filesystem.
 mkfs-opts ext2 /dev/sda1 blocksize:4096
-set-e2label /dev/sda1 BOOT
+set-label /dev/sda1 BOOT
 set-e2uuid /dev/sda1 01234567-0123-0123-0123-012345678901
 
 # Phony root and other filesystems.

tests/guests/guest-aux/make-fedora-img.pl

@@ -126,12 +126,12 @@ $g->lvcreate('LV3', 'VG', 64);
 
 # Phony /boot filesystem
 $g->mkfs_opts('ext2', $bootdev, blocksize => 4096);
-$g->set_e2label($bootdev, 'BOOT');
+$g->set_label($bootdev, 'BOOT');
 $g->set_e2uuid($bootdev, '01234567-0123-0123-0123-012345678901');
 
 # Phony root filesystem.
 $g->mkfs_opts('ext2', '/dev/VG/Root', blocksize => 4096);
-$g->set_e2label('/dev/VG/Root', 'ROOT');
+$g->set_label('/dev/VG/Root', 'ROOT');
 $g->set_e2uuid('/dev/VG/Root', '01234567-0123-0123-0123-012345678902');
 
 # Enough to fool inspection API.

tests/guests/guest-aux/make-ubuntu-img.sh

@@ -47,7 +47,7 @@ part-add /dev/sda p 524288    -64
 
 # Phony /boot filesystem.
 mkfs-opts ext2 /dev/sda1 blocksize:4096
-set-e2label /dev/sda1 BOOT
+set-label /dev/sda1 BOOT
 set-e2uuid /dev/sda1 01234567-0123-0123-0123-012345678901
 
 # Phony root filesystem (Ubuntu doesn't use LVM by default).