2015-11-04 18:59:47

by Stephen Hemminger

Subject: [PATCH] overlayfs: move super block magic number to magic.h

The overlayfs file system is not recognized by programs
like tail because the magic number is not in standard header location.

Move it so that the value will propagate on for the GNU library
and utilities. Needs to go in the fstatfs manual page as well.

Signed-off-by: Stephen Hemminger <[email protected]>
---
fs/overlayfs/super.c | 2 --
include/uapi/linux/magic.h | 1 +
2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index e38ee0f..a389675 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -24,8 +24,6 @@ MODULE_AUTHOR("Miklos Szeredi <[email protected]>");
MODULE_DESCRIPTION("Overlay filesystem");
MODULE_LICENSE("GPL");

-#define OVERLAYFS_SUPER_MAGIC 0x794c7630
-
struct ovl_config {
char *lowerdir;
char *upperdir;
diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h
index accb036..63ccb03 100644
--- a/include/uapi/linux/magic.h
+++ b/include/uapi/linux/magic.h
@@ -31,6 +31,7 @@
#define PSTOREFS_MAGIC 0x6165676C
#define EFIVARFS_MAGIC 0xde5e81e4
#define HOSTFS_SUPER_MAGIC 0x00c0ffee
+#define OVERLAYFS_SUPER_MAGIC 0x794c7630

#define MINIX_SUPER_MAGIC 0x137F /* minix v1 fs, 14 char names */
#define MINIX_SUPER_MAGIC2 0x138F /* minix v1 fs, 30 char names */
--
2.1.4

2015-11-10 16:13:10

by Miklos Szeredi

Subject: Re: [PATCH] overlayfs: move super block magic number to magic.h

On Wed, Nov 4, 2015 at 7:59 PM, Stephen Hemminger
<[email protected]> wrote:
> The overlayfs file system is not recognized by programs
> like tail because the magic number is not in standard header location.
>
> Move it so that the value will propagate on for the GNU library
> and utilities. Needs to go in the fstatfs manual page as well.
>
> Signed-off-by: Stephen Hemminger <[email protected]>

Thanks, pushed to

git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git overlayfs-next

Miklos