[PATCH] xfs_io: add support for O_TMPFILE opens

[PATCH] xfs_io: add support for O_TMPFILE opens

[Christoph Hellwig]

Add a new -T argument to the open command that supports using the
O_TMPFILE flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/io/io.h b/io/io.h
index 6c3f627..0d2d768 100644
--- a/io/io.h
+++ b/io/io.h
@@ -35,6 +35,7 @@
 #define IO_TRUNC	(1<<6)
 #define IO_FOREIGN	(1<<7)
 #define IO_NONBLOCK	(1<<8)
+#define IO_TMPFILE	(1<<9)
 
 /*
  * Regular file I/O control
diff --git a/io/open.c b/io/open.c
index cc677e6..c97968e 100644
--- a/io/open.c
+++ b/io/open.c
@@ -22,6 +22,22 @@
 #include "init.h"
 #include "io.h"
 
+#ifndef __O_TMPFILE
+#if defined __alpha__
+#define __O_TMPFILE	0100000000
+#elif defined(__hppa__)
+#define __O_TMPFILE	 040000000
+#elif defined(__sparc__)
+#define __O_TMPFILE	 0x2000000
+#else
+#define __O_TMPFILE	 020000000
+#endif
+#endif /* __O_TMPFILE */
+
+#ifndef O_TMPFILE
+#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
+#endif
+
 static cmdinfo_t open_cmd;
 static cmdinfo_t stat_cmd;
 static cmdinfo_t close_cmd;
@@ -143,10 +159,13 @@ openfile(
 		oflags |= O_TRUNC;
 	if (flags & IO_NONBLOCK)
 		oflags |= O_NONBLOCK;
+	if (flags & IO_TMPFILE)
+		oflags |= O_TMPFILE;
 
 	fd = open(path, oflags, mode);
 	if (fd < 0) {
-		if ((errno == EISDIR) && (oflags & O_RDWR)) {
+		if (errno == EISDIR &&
+		    ((oflags & (O_RDWR|O_TMPFILE)) == O_RDWR)) {
 			/* make it as if we asked for O_RDONLY & try again */
 			oflags &= ~O_RDWR;
 			oflags |= O_RDONLY;
@@ -248,6 +267,7 @@ open_help(void)
 " -s -- open with O_SYNC\n"
 " -t -- open with O_TRUNC (truncate the file to zero length if it exists)\n"
 " -R -- mark the file as a realtime XFS file immediately after opening it\n"
+" -T -- open with O_TMPFILE (create a file not visible in the namespace)\n"
 " Note1: usually read/write direct IO requests must be blocksize aligned;\n"
 "        some kernels, however, allow sectorsize alignment for direct IO.\n"
 " Note2: the bmap for non-regular files can be obtained provided the file\n"
@@ -272,7 +292,7 @@ open_f(
 		return 0;
 	}
 
-	while ((c = getopt(argc, argv, "FRacdfm:nrstx")) != EOF) {
+	while ((c = getopt(argc, argv, "FRTacdfm:nrstx")) != EOF) {
 		switch (c) {
 		case 'F':
 			/* Ignored / deprecated now, handled automatically */
@@ -310,6 +330,9 @@ open_f(
 		case 'x':	/* backwards compatibility */
 			flags |= IO_REALTIME;
 			break;
+		case 'T':
+			flags |= IO_TMPFILE;
+			break;
 		default:
 			return command_usage(&open_cmd);
 		}
@@ -325,6 +348,11 @@ open_f(
 	if (!platform_test_xfs_fd(fd))
 		flags |= IO_FOREIGN;
 
+	if ((flags & (IO_READONLY|IO_TMPFILE)) == (IO_READONLY|IO_TMPFILE)) {
+		fprintf(stderr, _("-T and -r options are incompatible\n"));
+		return -1;
+	}
+
 	addfile(argv[optind], fd, &geometry, flags);
 	return 0;
 }
@@ -731,7 +759,7 @@ open_init(void)
 	open_cmd.argmin = 0;
 	open_cmd.argmax = -1;
 	open_cmd.flags = CMD_NOMAP_OK | CMD_NOFILE_OK | CMD_FOREIGN_OK;
-	open_cmd.args = _("[-acdrstx] [path]");
+	open_cmd.args = _("[-acdrstxT] [path]");
 	open_cmd.oneline = _("open the file specified by path");
 	open_cmd.help = open_help;
 
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 9543b20..124360d 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -88,7 +88,7 @@ command for more details on any command.
 Display a list of all open files and (optionally) switch to an alternate
 current open file.
 .TP
-.BI "open [[ \-acdfrstR ] " path " ]"
+.BI "open [[ \-acdfrstRT ] " path " ]"
 Closes the current file, and opens the file specified by
 .I path
 instead. Without any arguments, displays statistics about the current
@@ -119,6 +119,14 @@ truncates on open (O_TRUNC).
 .B \-n
 opens in non-blocking mode if possible (O_NONBLOCK).
 .TP
+.B \-T
+create a temporary file not linked into the filesystem namepspace
+(O_TMPFILE).  The pathname passed must refer to a directory which
+is treated as virtual parent for the newly created invisible file.
+Can not be used together with the
+.B \-r
+option.
+.TP
 .B \-R
 marks the file as a realtime XFS file after
 opening it, if it is not already marked as such.

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_io: add support for O_TMPFILE opens

[Dave Chinner]

On Thu, Feb 20, 2014 at 02:00:00PM -0800, Christoph Hellwig wrote:
> Add a new -T argument to the open command that supports using the
> O_TMPFILE flag.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Can you also push this into the main CLI interface similar to how
all the other open flags can be specified? i.e.

$ xfs_io -d -c "pwrite 0 4k" foo

will open "foo" with O_DIRECT. Be nice just to be able to do

$ xfs_io -dT -c "pwrite 0 4k" foo/

to be able to test O_TMPFILE functionality

FWIW, any plans to add a "link" command to be able to link the
tmpfile into the namespace once it is created?

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_io: add support for O_TMPFILE opens

[Christoph Hellwig]

On Fri, Feb 21, 2014 at 09:15:18AM +1100, Dave Chinner wrote:
> Can you also push this into the main CLI interface similar to how
> all the other open flags can be specified?

Sure.

> FWIW, any plans to add a "link" command to be able to link the
> tmpfile into the namespace once it is created?

I was planning to do that, but as pointed out in my next mail it seems
we don't actually have any other namespace commands in xfs_io, so I'm
starting to wonder if it's the right place.

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

RE: [PATCH] xfs_io: add support for O_TMPFILE opens

[Shaun Gosse]

Very minor point, but you've got a typo in the documentation portion of your patch.

+create a temporary file not linked into the filesystem namepspace 

Should be "namespace" of course.

Cheers,
-Shaun

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_io: add support for O_TMPFILE opens

[Christoph Hellwig]

On Fri, Feb 21, 2014 at 12:16:58AM +0000, Shaun Gosse wrote:
> Very minor point, but you've got a typo in the documentation portion of your patch.
> 
> +create a temporary file not linked into the filesystem namepspace 
> 
> Should be "namespace" of course.

Thanks Shaun, I'll fix it for the next version.

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH v2] xfs_io: add support for O_TMPFILE opens

[Christoph Hellwig]

On Thu, Feb 20, 2014 at 02:00:00PM -0800, Christoph Hellwig wrote:
Add a new -T argument to the open command that supports using the
O_TMPFILE flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>

---

Changes from V1:
 - fix typo in the man page
 - add -T option to the main option parser
 - handle IO_TMPFILE in the file and stat commands

diff --git a/io/file.c b/io/file.c
index db85ffc..73b893f 100644
--- a/io/file.c
+++ b/io/file.c
@@ -36,7 +36,7 @@ print_fileio(
 	int		index,
 	int		braces)
 {
-	printf(_("%c%03d%c %-14s (%s,%s,%s,%s%s%s%s)\n"),
+	printf(_("%c%03d%c %-14s (%s,%s,%s,%s%s%s%s%s)\n"),
 		braces? '[' : ' ', index, braces? ']' : ' ', file->name,
 		file->flags & IO_FOREIGN ? _("foreign") : _("xfs"),
 		file->flags & IO_OSYNC ? _("sync") : _("non-sync"),
@@ -44,7 +44,8 @@ print_fileio(
 		file->flags & IO_READONLY ? _("read-only") : _("read-write"),
 		file->flags & IO_REALTIME ? _(",real-time") : "",
 		file->flags & IO_APPEND ? _(",append-only") : "",
-		file->flags & IO_NONBLOCK ? _(",non-block") : "");
+		file->flags & IO_NONBLOCK ? _(",non-block") : "",
+		file->flags & IO_TMPFILE ? _(",tmpfile") : "");
 }
 
 int
diff --git a/io/init.c b/io/init.c
index ef9e4cb..fd1a52f 100644
--- a/io/init.c
+++ b/io/init.c
@@ -136,7 +136,7 @@ init(
 	pagesize = getpagesize();
 	gettimeofday(&stopwatch, NULL);
 
-	while ((c = getopt(argc, argv, "ac:dFfmp:nrRstVx")) != EOF) {
+	while ((c = getopt(argc, argv, "ac:dFfmp:nrRstTVx")) != EOF) {
 		switch (c) {
 		case 'a':
 			flags |= IO_APPEND;
@@ -179,6 +179,8 @@ init(
 		case 'R':
 			flags |= IO_REALTIME;
 			break;
+		case 'T':
+			flags |= IO_TMPFILE;
 		case 'x':
 			expert = 1;
 			break;
diff --git a/io/io.h b/io/io.h
index 6c3f627..0d2d768 100644
--- a/io/io.h
+++ b/io/io.h
@@ -35,6 +35,7 @@
 #define IO_TRUNC	(1<<6)
 #define IO_FOREIGN	(1<<7)
 #define IO_NONBLOCK	(1<<8)
+#define IO_TMPFILE	(1<<9)
 
 /*
  * Regular file I/O control
diff --git a/io/open.c b/io/open.c
index cc677e6..6bb0d46 100644
--- a/io/open.c
+++ b/io/open.c
@@ -22,6 +22,22 @@
 #include "init.h"
 #include "io.h"
 
+#ifndef __O_TMPFILE
+#if defined __alpha__
+#define __O_TMPFILE	0100000000
+#elif defined(__hppa__)
+#define __O_TMPFILE	 040000000
+#elif defined(__sparc__)
+#define __O_TMPFILE	 0x2000000
+#else
+#define __O_TMPFILE	 020000000
+#endif
+#endif /* __O_TMPFILE */
+
+#ifndef O_TMPFILE
+#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
+#endif
+
 static cmdinfo_t open_cmd;
 static cmdinfo_t stat_cmd;
 static cmdinfo_t close_cmd;
@@ -77,13 +93,14 @@ stat_f(
 	int		verbose = (argc == 2 && !strcmp(argv[1], "-v"));
 
 	printf(_("fd.path = \"%s\"\n"), file->name);
-	printf(_("fd.flags = %s,%s,%s%s%s%s\n"),
+	printf(_("fd.flags = %s,%s,%s%s%s%s%s\n"),
 		file->flags & IO_OSYNC ? _("sync") : _("non-sync"),
 		file->flags & IO_DIRECT ? _("direct") : _("non-direct"),
 		file->flags & IO_READONLY ? _("read-only") : _("read-write"),
 		file->flags & IO_REALTIME ? _(",real-time") : "",
 		file->flags & IO_APPEND ? _(",append-only") : "",
-		file->flags & IO_NONBLOCK ? _(",non-block") : "");
+		file->flags & IO_NONBLOCK ? _(",non-block") : "",
+		file->flags & IO_TMPFILE ? _(",tmpfile") : "");
 	if (fstat64(file->fd, &st) < 0) {
 		perror("fstat64");
 	} else {
@@ -143,10 +160,13 @@ openfile(
 		oflags |= O_TRUNC;
 	if (flags & IO_NONBLOCK)
 		oflags |= O_NONBLOCK;
+	if (flags & IO_TMPFILE)
+		oflags |= O_TMPFILE;
 
 	fd = open(path, oflags, mode);
 	if (fd < 0) {
-		if ((errno == EISDIR) && (oflags & O_RDWR)) {
+		if (errno == EISDIR &&
+		    ((oflags & (O_RDWR|O_TMPFILE)) == O_RDWR)) {
 			/* make it as if we asked for O_RDONLY & try again */
 			oflags &= ~O_RDWR;
 			oflags |= O_RDONLY;
@@ -248,6 +268,7 @@ open_help(void)
 " -s -- open with O_SYNC\n"
 " -t -- open with O_TRUNC (truncate the file to zero length if it exists)\n"
 " -R -- mark the file as a realtime XFS file immediately after opening it\n"
+" -T -- open with O_TMPFILE (create a file not visible in the namespace)\n"
 " Note1: usually read/write direct IO requests must be blocksize aligned;\n"
 "        some kernels, however, allow sectorsize alignment for direct IO.\n"
 " Note2: the bmap for non-regular files can be obtained provided the file\n"
@@ -272,7 +293,7 @@ open_f(
 		return 0;
 	}
 
-	while ((c = getopt(argc, argv, "FRacdfm:nrstx")) != EOF) {
+	while ((c = getopt(argc, argv, "FRTacdfm:nrstx")) != EOF) {
 		switch (c) {
 		case 'F':
 			/* Ignored / deprecated now, handled automatically */
@@ -310,6 +331,9 @@ open_f(
 		case 'x':	/* backwards compatibility */
 			flags |= IO_REALTIME;
 			break;
+		case 'T':
+			flags |= IO_TMPFILE;
+			break;
 		default:
 			return command_usage(&open_cmd);
 		}
@@ -325,6 +349,11 @@ open_f(
 	if (!platform_test_xfs_fd(fd))
 		flags |= IO_FOREIGN;
 
+	if ((flags & (IO_READONLY|IO_TMPFILE)) == (IO_READONLY|IO_TMPFILE)) {
+		fprintf(stderr, _("-T and -r options are incompatible\n"));
+		return -1;
+	}
+
 	addfile(argv[optind], fd, &geometry, flags);
 	return 0;
 }
@@ -731,7 +760,7 @@ open_init(void)
 	open_cmd.argmin = 0;
 	open_cmd.argmax = -1;
 	open_cmd.flags = CMD_NOMAP_OK | CMD_NOFILE_OK | CMD_FOREIGN_OK;
-	open_cmd.args = _("[-acdrstx] [path]");
+	open_cmd.args = _("[-acdrstxT] [path]");
 	open_cmd.oneline = _("open the file specified by path");
 	open_cmd.help = open_help;
 
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 9543b20..7a92ff6 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -4,7 +4,7 @@ xfs_io \- debug the I/O path of an XFS filesystem
 .SH SYNOPSIS
 .B xfs_io
 [
-.B \-adfmrRstx
+.B \-adfmrRstxT
 ] [
 .B \-c
 .I cmd
@@ -88,7 +88,7 @@ command for more details on any command.
 Display a list of all open files and (optionally) switch to an alternate
 current open file.
 .TP
-.BI "open [[ \-acdfrstR ] " path " ]"
+.BI "open [[ \-acdfrstRT ] " path " ]"
 Closes the current file, and opens the file specified by
 .I path
 instead. Without any arguments, displays statistics about the current
@@ -119,6 +119,14 @@ truncates on open (O_TRUNC).
 .B \-n
 opens in non-blocking mode if possible (O_NONBLOCK).
 .TP
+.B \-T
+create a temporary file not linked into the filesystem namespace
+(O_TMPFILE).  The pathname passed must refer to a directory which
+is treated as virtual parent for the newly created invisible file.
+Can not be used together with the
+.B \-r
+option.
+.TP
 .B \-R
 marks the file as a realtime XFS file after
 opening it, if it is not already marked as such.

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH v2] xfs_io: add support for O_TMPFILE opens

[Dave Chinner]

On Thu, Feb 20, 2014 at 04:30:15PM -0800, Christoph Hellwig wrote:
> On Thu, Feb 20, 2014 at 02:00:00PM -0800, Christoph Hellwig wrote:
> Add a new -T argument to the open command that supports using the
> O_TMPFILE flag.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_io: add support for flink

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/io/Makefile b/io/Makefile
index eaeb5b2..c16af87 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -9,8 +9,8 @@ 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 mmap.c \
-	open.c parent.c pread.c prealloc.c pwrite.c seek.c shutdown.c \
+	attr.c bmap.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 seek.c shutdown.c \
 	truncate.c
 
 LLDLIBS = $(LIBXCMD) $(LIBHANDLE)
diff --git a/io/init.c b/io/init.c
index fd1a52f..7d7bb89 100644
--- a/io/init.c
+++ b/io/init.c
@@ -58,6 +58,7 @@ init_commands(void)
 	bmap_init();
 	fadvise_init();
 	file_init();
+	flink_init();
 	freeze_init();
 	fsync_init();
 	getrusage_init();
diff --git a/io/io.h b/io/io.h
index 0d2d768..1b3bca1 100644
--- a/io/io.h
+++ b/io/io.h
@@ -93,6 +93,7 @@ extern void		dump_buffer(off64_t, ssize_t);
 extern void		attr_init(void);
 extern void		bmap_init(void);
 extern void		file_init(void);
+extern void		flink_init(void);
 extern void		freeze_init(void);
 extern void		fsync_init(void);
 extern void		getrusage_init(void);
diff --git a/io/link.c b/io/link.c
new file mode 100644
index 0000000..49ca6a5
--- /dev/null
+++ b/io/link.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2014 Christoph Hellwig.
+ * 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 <xfs/xfs.h>
+#include <xfs/command.h>
+#include <xfs/input.h>
+#include "init.h"
+#include "io.h"
+
+#ifndef AT_EMPTY_PATH
+#define AT_EMPTY_PATH	0x1000
+#endif
+
+static cmdinfo_t flink_cmd;
+
+static void
+flink_help(void)
+{
+	printf(_(
+"\n"
+"link the open file descriptor into the filesystem\n"
+"\n"
+"\n"));
+}
+
+static int
+flink_f(
+	int		argc,
+	char		**argv)
+{
+	if (argc != 2)
+		return command_usage(&flink_cmd);
+
+	if (linkat(file->fd, "", AT_FDCWD, argv[1], AT_EMPTY_PATH) < 0) {
+		perror("flink");
+		return 0;
+	}
+	return 0;
+}
+
+void
+flink_init(void)
+{
+	flink_cmd.name = "flink";
+	flink_cmd.cfunc = flink_f;
+	flink_cmd.argmin = 1;
+	flink_cmd.argmax = 1;
+	flink_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
+	flink_cmd.args = _("filename");
+	flink_cmd.oneline =
+		_("link the open file descriptor into the filesystem");
+	flink_cmd.help = flink_help;
+
+	add_command(&flink_cmd);
+}
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 7a92ff6..7d0c792 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -638,6 +638,9 @@ Only available in expert mode and requires privileges.
 Undo the effects of a filesystem freeze operation.
 Only available in expert mode and requires privileges.
 .TP
+.B flink		
+Link the currently open file descriptor into the filesystem namespace.
+.TP
 .BI "inject [ " tag " ]"
 Inject errors into a filesystem to observe filesystem behavior at
 specific points under adverse conditions. Without the

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH] xfs_io: add support for flink

[Dave Chinner]

On Thu, Feb 20, 2014 at 04:49:33PM -0800, Christoph Hellwig wrote:
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
.....
> +static cmdinfo_t flink_cmd;
> +
> +static void
> +flink_help(void)
> +{
> +	printf(_(
> +"\n"
> +"link the open file descriptor into the filesystem\n"
> +"\n"
> +"\n"));
> +}

"link the open file descriptor to the supplied filename\n"

?

> +void
> +flink_init(void)
> +{
> +	flink_cmd.name = "flink";
> +	flink_cmd.cfunc = flink_f;
> +	flink_cmd.argmin = 1;
> +	flink_cmd.argmax = 1;
> +	flink_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
> +	flink_cmd.args = _("filename");
> +	flink_cmd.oneline =
> +		_("link the open file descriptor into the filesystem");
> +	flink_cmd.help = flink_help;
> +
> +	add_command(&flink_cmd);
> +}
> diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
> index 7a92ff6..7d0c792 100644
> --- a/man/man8/xfs_io.8
> +++ b/man/man8/xfs_io.8
> @@ -638,6 +638,9 @@ Only available in expert mode and requires privileges.
>  Undo the effects of a filesystem freeze operation.
>  Only available in expert mode and requires privileges.
>  .TP
> +.B flink		
> +Link the currently open file descriptor into the filesystem namespace.
> +.TP

And that needs to indicate that a filename needs to be provided,
too.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH v2] xfs_io: add support for flink

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/io/Makefile b/io/Makefile
index eaeb5b2..c16af87 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -9,8 +9,8 @@ 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 mmap.c \
-	open.c parent.c pread.c prealloc.c pwrite.c seek.c shutdown.c \
+	attr.c bmap.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 seek.c shutdown.c \
 	truncate.c
 
 LLDLIBS = $(LIBXCMD) $(LIBHANDLE)
diff --git a/io/init.c b/io/init.c
index fd1a52f..7d7bb89 100644
--- a/io/init.c
+++ b/io/init.c
@@ -58,6 +58,7 @@ init_commands(void)
 	bmap_init();
 	fadvise_init();
 	file_init();
+	flink_init();
 	freeze_init();
 	fsync_init();
 	getrusage_init();
diff --git a/io/io.h b/io/io.h
index 0d2d768..1b3bca1 100644
--- a/io/io.h
+++ b/io/io.h
@@ -93,6 +93,7 @@ extern void		dump_buffer(off64_t, ssize_t);
 extern void		attr_init(void);
 extern void		bmap_init(void);
 extern void		file_init(void);
+extern void		flink_init(void);
 extern void		freeze_init(void);
 extern void		fsync_init(void);
 extern void		getrusage_init(void);
diff --git a/io/link.c b/io/link.c
new file mode 100644
index 0000000..9c2d1f8
--- /dev/null
+++ b/io/link.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2014 Christoph Hellwig.
+ * 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 <xfs/xfs.h>
+#include <xfs/command.h>
+#include <xfs/input.h>
+#include "init.h"
+#include "io.h"
+
+#ifndef AT_EMPTY_PATH
+#define AT_EMPTY_PATH	0x1000
+#endif
+
+static cmdinfo_t flink_cmd;
+
+static void
+flink_help(void)
+{
+	printf(_(
+"\n"
+"link the open file descriptor to the supplied filename\n"
+"\n"
+"\n"));
+}
+
+static int
+flink_f(
+	int		argc,
+	char		**argv)
+{
+	if (argc != 2)
+		return command_usage(&flink_cmd);
+
+	if (linkat(file->fd, "", AT_FDCWD, argv[1], AT_EMPTY_PATH) < 0) {
+		perror("flink");
+		return 0;
+	}
+	return 0;
+}
+
+void
+flink_init(void)
+{
+	flink_cmd.name = "flink";
+	flink_cmd.cfunc = flink_f;
+	flink_cmd.argmin = 1;
+	flink_cmd.argmax = 1;
+	flink_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
+	flink_cmd.args = _("filename");
+	flink_cmd.oneline =
+		_("link the open file descriptor to the supplied filename");
+	flink_cmd.help = flink_help;
+
+	add_command(&flink_cmd);
+}
diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
index 7a92ff6..72f8210 100644
--- a/man/man8/xfs_io.8
+++ b/man/man8/xfs_io.8
@@ -638,6 +638,10 @@ Only available in expert mode and requires privileges.
 Undo the effects of a filesystem freeze operation.
 Only available in expert mode and requires privileges.
 .TP
+.BI "flink " path
+Reads a range of bytes in a specified blocksize from the given
+Link the currently open file descriptor into the filesystem namespace.
+.TP
 .BI "inject [ " tag " ]"
 Inject errors into a filesystem to observe filesystem behavior at
 specific points under adverse conditions. Without the

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH v2] xfs_io: add support for flink

[Dave Chinner]

On Tue, Feb 25, 2014 at 11:52:18AM -0800, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>
....
> --- a/man/man8/xfs_io.8
> +++ b/man/man8/xfs_io.8
> @@ -638,6 +638,10 @@ Only available in expert mode and requires privileges.
>  Undo the effects of a filesystem freeze operation.
>  Only available in expert mode and requires privileges.
>  .TP
> +.BI "flink " path
> +Reads a range of bytes in a specified blocksize from the given
> +Link the currently open file descriptor into the filesystem namespace.
> +.TP

Looks like some noise got into that hunk. Other than that:

Reviewed-by: Dave Chinner <dchinner@redhat.com>

I'll remove that extra line when I commit it.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH v2] xfs_io: add support for flink

[Christoph Hellwig]

On Wed, Feb 26, 2014 at 10:35:57AM +1100, Dave Chinner wrote:
> Looks like some noise got into that hunk. Other than that:
> 
> Reviewed-by: Dave Chinner <dchinner@redhat.com>
> 
> I'll remove that extra line when I commit it.

ping?

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH v2] xfs_io: add support for flink

[Dave Chinner]

On Thu, Mar 13, 2014 at 03:09:33AM -0700, Christoph Hellwig wrote:
> On Wed, Feb 26, 2014 at 10:35:57AM +1100, Dave Chinner wrote:
> > Looks like some noise got into that hunk. Other than that:
> > 
> > Reviewed-by: Dave Chinner <dchinner@redhat.com>
> > 
> > I'll remove that extra line when I commit it.
> 
> ping?

Sorry, I missed them in the last round of commits. I'll sort it out.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH v2] xfs_io: add support for flink

[Dave Chinner]

On Thu, Mar 13, 2014 at 09:21:08PM +1100, Dave Chinner wrote:
> On Thu, Mar 13, 2014 at 03:09:33AM -0700, Christoph Hellwig wrote:
> > On Wed, Feb 26, 2014 at 10:35:57AM +1100, Dave Chinner wrote:
> > > Looks like some noise got into that hunk. Other than that:
> > > 
> > > Reviewed-by: Dave Chinner <dchinner@redhat.com>
> > > 
> > > I'll remove that extra line when I commit it.
> > 
> > ping?
> 
> Sorry, I missed them in the last round of commits. I'll sort it out.

OK, committed and pushed - aa210c4 should be the new head.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs