From cfa10b0f972005b38ed294bca66cebf2f65298ec Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
Date: Thu, 24 May 2018 14:48:33 -0500
Subject: [PATCH] xfs_io: add label command
This adds an online get/set/clear label command to xfs_io.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---
io/Makefile | 6 +--
io/init.c | 1 +
io/io.h | 1 +
io/label.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
man/man8/xfs_io.8 | 13 +++++++
5 files changed, 126 insertions(+), 3 deletions(-)
create mode 100644 io/label.c
Index: xfsprogs-4.5.0/io/Makefile
===================================================================
--- xfsprogs-4.5.0.orig/io/Makefile
+++ xfsprogs-4.5.0/io/Makefile
@@ -9,7 +9,7 @@ LTCOMMAND = xfs_io
LSRCFILES = xfs_bmap.sh xfs_freeze.sh xfs_mkfile.sh
HFILES = init.h io.h
CFILES = init.c \
- attr.c bmap.c file.c freeze.c fsync.c getrusage.c imap.c link.c \
+ attr.c bmap.c file.c freeze.c fsync.c getrusage.c imap.c label.c link.c \
mmap.c open.c parent.c pread.c prealloc.c pwrite.c seek.c shutdown.c \
sync.c truncate.c reflink.c
Index: xfsprogs-4.5.0/io/init.c
===================================================================
--- xfsprogs-4.5.0.orig/io/init.c
+++ xfsprogs-4.5.0/io/init.c
@@ -65,6 +65,7 @@ init_commands(void)
help_init();
imap_init();
inject_init();
+ label_init();
seek_init();
madvise_init();
mincore_init();
Index: xfsprogs-4.5.0/io/io.h
===================================================================
--- xfsprogs-4.5.0.orig/io/io.h
+++ xfsprogs-4.5.0/io/io.h
@@ -102,6 +102,7 @@ extern void getrusage_init(void);
extern void help_init(void);
extern void imap_init(void);
extern void inject_init(void);
+extern void label_init(void);
extern void mmap_init(void);
extern void open_init(void);
extern void parent_init(void);
Index: xfsprogs-4.5.0/io/label.c
===================================================================
--- /dev/null
+++ xfsprogs-4.5.0/io/label.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2018 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it would 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 the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include "platform_defs.h"
+#include "libxfs.h"
+#include "path.h"
+#include "command.h"
+#include "init.h"
+#include "io.h"
+
+#ifndef FS_IOC_GETFSLABEL
+/* Max chars for the interface; fs limits may differ */
+#define FSLABEL_MAX 256
+#define FS_IOC_GETFSLABEL _IOR(0x94, 49, char[FSLABEL_MAX])
+#define FS_IOC_SETFSLABEL _IOW(0x94, 50, char[FSLABEL_MAX])
+#endif
+
+static cmdinfo_t label_cmd;
+
+static void
+label_help(void)
+{
+ printf(_(
+"\n"
+" Manipulate or query the filesystem label while mounted.\n"
+"\n"
+" With no arguments, displays the current filesystem label.\n"
+" -s newlabel -- set the filesystem label to newlabel\n"
+" -c -- clear the filesystem label (sets to NULL string)\n"
+"\n"));
+}
+
+static int
+label_f(
+ int argc,
+ char **argv)
+{
+ int c;
+ int error;
+ char label[FSLABEL_MAX];
+
+ if (argc == 1) {
+ memset(label, 0, sizeof(label));
+ error = ioctl(file->fd, FS_IOC_GETFSLABEL, &label);
+ goto out;
+ }
+
+ while ((c = getopt(argc, argv, "cs:")) != EOF) {
+ switch (c) {
+ case 'c':
+ label[0] = '\0';
+ break;
+ case 's':
+ strncpy(label, optarg, sizeof(label));
+ break;
+ default:
+ return command_usage(&label_cmd);
+ }
+ }
+
+ /* Check for trailing arguments */
+ if (argc != optind)
+ return command_usage(&label_cmd);
+
+ error = ioctl(file->fd, FS_IOC_SETFSLABEL, label);
+out:
+ if (error) {
+ perror("label");
+ exitcode = 1;
+ } else {
+ printf("label = \"%s\"\n", label);
+ }
+
+ return 0;
+}
+
+void
+label_init(void)
+{
+ label_cmd.name = "label";
+ label_cmd.cfunc = label_f;
+ label_cmd.argmin = 0;
+ label_cmd.argmax = 3;
+ label_cmd.args = _("[-s label|-c]");
+ label_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
+ label_cmd.oneline =
+ _("query, set, or clear the filesystem label while mounted");
+ label_cmd.help = label_help;
+
+ add_command(&label_cmd);
+}
Index: xfsprogs-4.5.0/man/man8/xfs_io.8
===================================================================
--- xfsprogs-4.5.0.orig/man/man8/xfs_io.8
+++ xfsprogs-4.5.0/man/man8/xfs_io.8
@@ -812,7 +812,19 @@ verbose output will be printed.
.IP
.B [NOTE: Not currently operational on Linux.]
.PD
-
+.TP
+.BI "label" " " "[ -c | -s " label " ] "
+On filesystems that support online label manipulation, get, set, or clear the
+filesystem label. With no options, print the current filesystem label. The
+.B \-c
+option clears the filesystem label by setting it to the null string. The
+.BI "\-s " label
+option sets the filesystem label to
+.IR label .
+If the label is longer than the filesystem will accept,
+.B xfs_io
+will print an error message. XFS filesystem labels can be at most 12
+characters long.
.SH SEE ALSO
.BR mkfs.xfs (8),
.BR xfsctl (3),