[PATCH 5.10 016/104] tmpfs: disallow CONFIG_TMPFS_INODE64 on alpha

Greg Kroah-Hartman
2021-02-15T15:37:00Z

From: Seth Forshee <seth.forshee@canonical.com>

commit ad69c389ec110ea54f8b0c0884b255340ef1c736 upstream.

As with s390, alpha is a 64-bit architecture with a 32-bit ino_t. With
CONFIG_TMPFS_INODE64=y tmpfs mounts will get 64-bit inode numbers and
display "inode64" in the mount options, whereas passing "inode64" in the
mount options will fail. This leads to erroneous behaviours such as
this:

# mkdir mnt
# mount -t tmpfs nodev mnt
# mount -o remount,rw mnt
mount: /home/ubuntu/mnt: mount point not mounted or bad option.

Prevent CONFIG_TMPFS_INODE64 from being selected on alpha.

Link: https://lkml.kernel.org/r/20210208215726.608197-1-seth.forshee@canonical.com
Fixes: ea3271f7196c ("tmpfs: support 64-bit inums per-sb")
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: <stable@vger.kernel.org> [5.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -203,7 +203,7 @@ config TMPFS_XATTR

config TMPFS_INODE64
bool "Use 64-bit ino_t by default in tmpfs"
- depends on TMPFS && 64BIT && !S390
+ depends on TMPFS && 64BIT && !(S390 || ALPHA)
default n
help
tmpfs has historically used only inode numbers as wide as an unsigned