[PATCH 0/3] xfs_io: enable extsize and stat -v support for ext4

[PATCH 0/3] xfs_io: enable extsize and stat -v support for ext4

[Ojaswin Mujoo]

Changes since rfc [1]

 * Patch 1: Don't add ext4 specific checks
 * Patch 2: Rather than adding a check for ext4, allow FS_IOC_GETXATTR
   to be called by any FS that supports it.

[1]
https://lore.kernel.org/linux-ext4/cover.1733902742.git.ojaswin@linux.ibm.com/T/#t

** Original Cover **

With ext4 extsize hints support being worked on, enable extsize 
command to be run on FSes other than xfs so ext4 can utilize it.
Also extend stat -v to perform FS_IOC_FSGETXATTR ioctl on ext4.

No funtional changes are intended for XFS.

Ojaswin Mujoo (3):
  include/linux.h: use linux/magic.h to get XFS_SUPER_MAGIC
  xfs_io: allow foreign FSes to show FS_IOC_FSGETXATTR details
  xfs_io: add extsize command support

 include/linux.h |  3 ++-
 io/open.c       |  2 +-
 io/stat.c       | 63 ++++++++++++++++++++++++++++---------------------
 3 files changed, 39 insertions(+), 29 deletions(-)

-- 
2.43.5

[PATCH 1/3] include/linux.h: use linux/magic.h to get XFS_SUPER_MAGIC

[Ojaswin Mujoo]

This avoids open coding the magic number

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
---
 include/linux.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux.h b/include/linux.h
index e9eb7bfb26a1..306a31e092a7 100644
--- a/include/linux.h
+++ b/include/linux.h
@@ -37,6 +37,7 @@
 #endif
 #include <unistd.h>
 #include <assert.h>
+#include <linux/magic.h> /* super block magic numbers */
 
 static __inline__ int xfsctl(const char *path, int fd, int cmd, void *p)
 {
@@ -60,7 +61,7 @@ static __inline__ int platform_test_xfs_fd(int fd)
 		return 0;
 	if (!S_ISREG(statbuf.st_mode) && !S_ISDIR(statbuf.st_mode))
 		return 0;
-	return (statfsbuf.f_type == 0x58465342);	/* XFSB */
+	return (statfsbuf.f_type == XFS_SUPER_MAGIC);
 }
 
 static __inline__ int platform_test_xfs_path(const char *path)
-- 
2.43.5

[PATCH 2/3] xfs_io: allow foreign FSes to show FS_IOC_FSGETXATTR details

[Ojaswin Mujoo]

Currently with stat we only show FS_IOC_FSGETXATTR details if the
filesystem is XFS. With extsize support also coming to ext4 and possibly
other filesystems, make sure to allow foreign FSes to display these details
when "stat" or "statx" is used.

(Thanks to Dave for suggesting implementation of print_extended_info())

Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
---
 io/stat.c | 63 +++++++++++++++++++++++++++++++------------------------
 1 file changed, 36 insertions(+), 27 deletions(-)

diff --git a/io/stat.c b/io/stat.c
index 326f2822e276..3ce3308d0562 100644
--- a/io/stat.c
+++ b/io/stat.c
@@ -98,30 +98,45 @@ print_file_info(void)
 }
 
 static void
-print_xfs_info(int verbose)
+print_extended_info(int verbose)
 {
-	struct dioattr	dio;
-	struct fsxattr	fsx, fsxa;
-
-	if ((xfsctl(file->name, file->fd, FS_IOC_FSGETXATTR, &fsx)) < 0 ||
-	    (xfsctl(file->name, file->fd, XFS_IOC_FSGETXATTRA, &fsxa)) < 0) {
-		perror("FS_IOC_FSGETXATTR");
-	} else {
-		printf(_("fsxattr.xflags = 0x%x "), fsx.fsx_xflags);
-		printxattr(fsx.fsx_xflags, verbose, 0, file->name, 1, 1);
-		printf(_("fsxattr.projid = %u\n"), fsx.fsx_projid);
-		printf(_("fsxattr.extsize = %u\n"), fsx.fsx_extsize);
-		printf(_("fsxattr.cowextsize = %u\n"), fsx.fsx_cowextsize);
-		printf(_("fsxattr.nextents = %u\n"), fsx.fsx_nextents);
-		printf(_("fsxattr.naextents = %u\n"), fsxa.fsx_nextents);
+	struct dioattr dio = {};
+	struct fsxattr fsx = {}, fsxa = {};
+
+	if ((ioctl(file->fd, FS_IOC_FSGETXATTR, &fsx)) < 0) {
+		perror("FS_IOC_GETXATTR");
+		exitcode = 1;
+		return;
 	}
+
+	printf(_("fsxattr.xflags = 0x%x "), fsx.fsx_xflags);
+	printxattr(fsx.fsx_xflags, verbose, 0, file->name, 1, 1);
+	printf(_("fsxattr.projid = %u\n"), fsx.fsx_projid);
+	printf(_("fsxattr.extsize = %u\n"), fsx.fsx_extsize);
+	printf(_("fsxattr.cowextsize = %u\n"), fsx.fsx_cowextsize);
+	printf(_("fsxattr.nextents = %u\n"), fsx.fsx_nextents);
+
+	/* Only XFS supports FS_IOC_FSGETXATTRA and XFS_IOC_DIOINFO */
+	if (file->flags & IO_FOREIGN)
+		return;
+
+	if ((ioctl(file->fd, XFS_IOC_FSGETXATTRA, &fsxa)) < 0) {
+		perror("XFS_IOC_GETXATTRA");
+		exitcode = 1;
+		return;
+	}
+
+	printf(_("fsxattr.naextents = %u\n"), fsxa.fsx_nextents);
+
 	if ((xfsctl(file->name, file->fd, XFS_IOC_DIOINFO, &dio)) < 0) {
 		perror("XFS_IOC_DIOINFO");
-	} else {
-		printf(_("dioattr.mem = 0x%x\n"), dio.d_mem);
-		printf(_("dioattr.miniosz = %u\n"), dio.d_miniosz);
-		printf(_("dioattr.maxiosz = %u\n"), dio.d_maxiosz);
+		exitcode = 1;
+		return;
 	}
+
+	printf(_("dioattr.mem = 0x%x\n"), dio.d_mem);
+	printf(_("dioattr.miniosz = %u\n"), dio.d_miniosz);
+	printf(_("dioattr.maxiosz = %u\n"), dio.d_maxiosz);
 }
 
 int
@@ -167,10 +182,7 @@ stat_f(
 		printf(_("stat.ctime = %s"), ctime(&st.st_ctime));
 	}
 
-	if (file->flags & IO_FOREIGN)
-		return 0;
-
-	print_xfs_info(verbose);
+	print_extended_info(verbose);
 
 	return 0;
 }
@@ -440,10 +452,7 @@ statx_f(
 				ctime((time_t *)&stx.stx_btime.tv_sec));
 	}
 
-	if (file->flags & IO_FOREIGN)
-		return 0;
-
-	print_xfs_info(verbose);
+	print_extended_info(verbose);
 
 	return 0;
 }
-- 
2.43.5

[PATCH 3/3] xfs_io: add extsize command support

[Ojaswin Mujoo]

extsize command is currently only supported with XFS filesystem.
Lift this restriction now that ext4 is also supporting extsize hints.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
---
 io/open.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io/open.c b/io/open.c
index a30dd89a1fd5..2582ff9b862e 100644
--- a/io/open.c
+++ b/io/open.c
@@ -997,7 +997,7 @@ open_init(void)
 	extsize_cmd.args = _("[-D | -R] [extsize]");
 	extsize_cmd.argmin = 0;
 	extsize_cmd.argmax = -1;
-	extsize_cmd.flags = CMD_NOMAP_OK;
+	extsize_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
 	extsize_cmd.oneline =
 		_("get/set preferred extent size (in bytes) for the open file");
 	extsize_cmd.help = extsize_help;
-- 
2.43.5

Re: [PATCH 1/3] include/linux.h: use linux/magic.h to get XFS_SUPER_MAGIC

[Christoph Hellwig]

On Sun, Dec 15, 2024 at 02:47:15PM +0530, Ojaswin Mujoo wrote:
> -	return (statfsbuf.f_type == 0x58465342);	/* XFSB */
> +	return (statfsbuf.f_type == XFS_SUPER_MAGIC);

Might be worth dropping the superfluous braces here while you're at it.

Otherwise looks good:

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

Re: [PATCH 1/3] include/linux.h: use linux/magic.h to get XFS_SUPER_MAGIC

[Ojaswin Mujoo]

On Mon, Dec 16, 2024 at 12:28:00AM -0800, Christoph Hellwig wrote:
> On Sun, Dec 15, 2024 at 02:47:15PM +0530, Ojaswin Mujoo wrote:
> > -	return (statfsbuf.f_type == 0x58465342);	/* XFSB */
> > +	return (statfsbuf.f_type == XFS_SUPER_MAGIC);
> 
> Might be worth dropping the superfluous braces here while you're at it.

Thanks for the review Christoph, I will fix the braces here.

regards,
ojaswin
> 
> Otherwise looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
>