tmpfs: disallow CONFIG_TMPFS_INODE64 on s390

Currently there is an assumption in tmpfs that 64-bit architectures also
have a 64-bit ino_t.  This is not true on s390 which has 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, but passing the "inode64"
mount option will fail.  This leads to the following behavior:

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

As mount sees "inode64" in the mount options and thus passes it in the
options for the remount.

So prevent CONFIG_TMPFS_INODE64 from being selected on s390.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: ea3271f7196c ("tmpfs: support 64-bit inums per-sb")
Signed-off-by: Seth Forshee <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Cc: Chris Down <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Amir Goldstein <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: <[email protected]>	[5.9+]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/fs/Kconfig b/fs/Kconfig
index aa4c122823018b756cdc566c33e20dbf834dfb10..3347ec7bd83782e29dc6e3175fce4c33fedf20b9 100644 (file)
--- 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
+       depends on TMPFS && 64BIT && !S390
        default n
        help
          tmpfs has historically used only inode numbers as wide as an unsigned