diff mbox

[5/5] xfs_io: add label command

Message ID ef558e14-5b31-4c5a-a07c-3d2ac67dd993@redhat.com (mailing list archive)
State Superseded
Headers show

Commit Message

Eric Sandeen May 14, 2018, 5:43 p.m. UTC 
This adds a get/set label command to xfs_io.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
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Comments

Dave Chinner May 15, 2018, 4:32 a.m. UTC | #1 
On Mon, May 14, 2018 at 12:43:20PM -0500, Eric Sandeen wrote:
> This adds a get/set label command to xfs_io.
....
> +static int
> +label_f(
> +	int		argc,
> +	char		**argv)
> +{
> +	int		error;
> +	char		label[FSLABEL_MAX];
> +
> +	if (argc == 1) {
> +		memset(&label, 0, sizeof(label));
> +		error = ioctl(file->fd, FS_IOC_GET_FSLABEL, &label);
> +	} else {
> +		strncpy(label, argv[1], sizeof(label));
> +		error = ioctl(file->fd, FS_IOC_SET_FSLABEL, &label);
> +	}
> +
> +	if (error)
> +		perror("label");

Need to set exitcode = 1 here so that xfs_io fails with a non-zero
exit status....

> +	else
> +		printf("label = \"%s\"\n", label);
> +
> +	return error;

Because this isn't the exit status - this is the "continue
processing the next command" return value. i.e. return 0 if we want
to continue, non-zero if we want to abort further CLI processing....

Cheers,

Dave.
Eric Sandeen May 15, 2018, 3:06 p.m. UTC | #2 
On 5/14/18 11:32 PM, Dave Chinner wrote:
> On Mon, May 14, 2018 at 12:43:20PM -0500, Eric Sandeen wrote:
>> This adds a get/set label command to xfs_io.
> ....
>> +static int
>> +label_f(
>> +	int		argc,
>> +	char		**argv)
>> +{
>> +	int		error;
>> +	char		label[FSLABEL_MAX];
>> +
>> +	if (argc == 1) {
>> +		memset(&label, 0, sizeof(label));
>> +		error = ioctl(file->fd, FS_IOC_GET_FSLABEL, &label);
>> +	} else {
>> +		strncpy(label, argv[1], sizeof(label));
>> +		error = ioctl(file->fd, FS_IOC_SET_FSLABEL, &label);
>> +	}
>> +
>> +	if (error)
>> +		perror("label");
> 
> Need to set exitcode = 1 here so that xfs_io fails with a non-zero
> exit status....
> 
>> +	else
>> +		printf("label = \"%s\"\n", label);
>> +
>> +	return error;
> 
> Because this isn't the exit status - this is the "continue
> processing the next command" return value. i.e. return 0 if we want
> to continue, non-zero if we want to abort further CLI processing....

Hm, ok.  Today we only set exitcode for bmap, fiemap, freeze/thaw, and
imap.  It's really consistently used at all, and needs an audit I guess.

Maybe we should add an io_error() which sets it automatically, or something.

Anyway, I can add it here.

-Eric
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Dave Chinner May 16, 2018, 12:57 a.m. UTC | #3 
On Tue, May 15, 2018 at 10:06:53AM -0500, Eric Sandeen wrote:
> 
> 
> On 5/14/18 11:32 PM, Dave Chinner wrote:
> >On Mon, May 14, 2018 at 12:43:20PM -0500, Eric Sandeen wrote:
> >>This adds a get/set label command to xfs_io.
> >....
> >>+static int
> >>+label_f(
> >>+	int		argc,
> >>+	char		**argv)
> >>+{
> >>+	int		error;
> >>+	char		label[FSLABEL_MAX];
> >>+
> >>+	if (argc == 1) {
> >>+		memset(&label, 0, sizeof(label));
> >>+		error = ioctl(file->fd, FS_IOC_GET_FSLABEL, &label);
> >>+	} else {
> >>+		strncpy(label, argv[1], sizeof(label));
> >>+		error = ioctl(file->fd, FS_IOC_SET_FSLABEL, &label);
> >>+	}
> >>+
> >>+	if (error)
> >>+		perror("label");
> >
> >Need to set exitcode = 1 here so that xfs_io fails with a non-zero
> >exit status....
> >
> >>+	else
> >>+		printf("label = \"%s\"\n", label);
> >>+
> >>+	return error;
> >
> >Because this isn't the exit status - this is the "continue
> >processing the next command" return value. i.e. return 0 if we want
> >to continue, non-zero if we want to abort further CLI processing....
> 
> Hm, ok.  Today we only set exitcode for bmap, fiemap, freeze/thaw, and
> imap.  It's really consistently used at all, and needs an audit I guess.

You mean the audit I did 6 months ago?

https://www.spinics.net/lists/linux-xfs/msg13605.html

(which is why I know what the exitcode rules are. :)

The patch is still sitting around somewhere here....

Cheers,

Dave.
diff mbox

Patch

diff --git a/io/Makefile b/io/Makefile
index 88e4751..b40156d 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -10,9 +10,9 @@  LSRCFILES = xfs_bmap.sh xfs_freeze.sh xfs_mkfile.sh
 HFILES = init.h io.h
 CFILES = init.c \
 	attr.c bmap.c cowextsize.c encrypt.c file.c freeze.c fsync.c \
-	getrusage.c imap.c link.c mmap.c open.c parent.c pread.c prealloc.c \
-	pwrite.c reflink.c scrub.c seek.c shutdown.c stat.c swapext.c sync.c \
-	truncate.c utimes.c
+	getrusage.c imap.c label.c link.c mmap.c open.c parent.c pread.c \
+	prealloc.c pwrite.c reflink.c scrub.c seek.c shutdown.c stat.c \
+	swapext.c sync.c truncate.c utimes.c
 
 LLDLIBS = $(LIBXCMD) $(LIBHANDLE) $(LIBFROG) $(LIBPTHREAD)
 LTDEPENDENCIES = $(LIBXCMD) $(LIBHANDLE) $(LIBFROG)
diff --git a/io/init.c b/io/init.c
index 0336c96..612962e 100644
--- a/io/init.c
+++ b/io/init.c
@@ -72,6 +72,7 @@  init_commands(void)
 	help_init();
 	imap_init();
 	inject_init();
+	label_init();
 	log_writes_init();
 	madvise_init();
 	mincore_init();
diff --git a/io/io.h b/io/io.h
index a267636..7f8197c 100644
--- a/io/io.h
+++ b/io/io.h
@@ -109,6 +109,7 @@  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);
diff --git a/io/label.c b/io/label.c
new file mode 100644
index 0000000..acab67f
--- /dev/null
+++ b/io/label.c
@@ -0,0 +1,74 @@ 
+/*
+ * 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_GET_FSLABEL
+/* Max chars for the interface; fs limits may differ */
+#define FSLABEL_MAX 256
+#define FS_IOC_GET_FSLABEL		_IOR(0x94, 49, char[FSLABEL_MAX])
+#define FS_IOC_SET_FSLABEL		_IOW(0x94, 50, char[FSLABEL_MAX])
+#endif
+
+static cmdinfo_t label_cmd;
+
+static int
+label_f(
+	int		argc,
+	char		**argv)
+{
+	int		error;
+	char		label[FSLABEL_MAX];
+
+	if (argc == 1) {
+		memset(&label, 0, sizeof(label));
+		error = ioctl(file->fd, FS_IOC_GET_FSLABEL, &label);
+	} else {
+		strncpy(label, argv[1], sizeof(label));
+		error = ioctl(file->fd, FS_IOC_SET_FSLABEL, &label);
+	}
+
+	if (error)
+		perror("label");
+	else
+		printf("label = \"%s\"\n", label);
+
+	return error;
+}
+
+void
+label_init(void)
+{
+	label_cmd.name = "label";
+	label_cmd.cfunc = label_f;
+	label_cmd.argmin = 0;
+	label_cmd.argmax = 1;
+	label_cmd.args = _("[label]");
+	label_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
+	label_cmd.oneline =
+		_("query or set the filesystem label while mounted");
+
+	add_command(&label_cmd);
+}
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index c3ab532..52b983d 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -1175,6 +1175,16 @@  This is intended to be equivalent to the shell command:
 See the
 .B log_writes
 command.
+.TP
+.BI "label" " " [ " label " ]
+On  filesystems  that  support  online label manipulation, set or get the
+filesystem label.  With no options, get the current filesystem label.
+With one option, set 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),