+ tmpfs-disallow-config_tmpfs_inode64-on-s390.patch added to -mm tree

The patch titled
     Subject: tmpfs: disallow CONFIG_TMPFS_INODE64 on s390
has been added to the -mm tree.  Its filename is
     tmpfs-disallow-config_tmpfs_inode64-on-s390.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/tmpfs-disallow-config_tmpfs_inode64-on-s390.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/tmpfs-disallow-config_tmpfs_inode64-on-s390.patch

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------------------------------------------------------
From: Seth Forshee <redacted>
Subject: 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/20210205230620.518245-1-seth.forshee@canonical.com
Fixes: ea3271f7196c ("tmpfs: support 64-bit inums per-sb")
Signed-off-by: Seth Forshee <redacted>
Cc: Chris Down <chris@chrisdown.name>
Cc: Hugh Dickins <hughd@google.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <redacted>
Cc: <redacted>	[5.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/Kconfig~tmpfs-disallow-config_tmpfs_inode64-on-s390
+++ a/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

_

Patches currently in -mm which might be from seth.forshee@canonical.com are

tmpfs-disallow-config_tmpfs_inode64-on-s390.patch
tmpfs-dont-use-64-bit-inodes-by-defulat-with-32-bit-ino_t.patch