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),