The implicit FILEID_INO32_GEN encoder was changed to be explicit, so we need to fix the detection. When mounting overlayfs with upperdir and lowerdir on different ext4 filesystems, the expected kmsg log is: overlayfs: "xino" feature enabled using 32 upper inode bits. But instead, since the regressing commit, the kmsg log was: overlayfs: "xino" feature enabled using 2 upper inode bits. Fixes: e21fc2038c1b9 ("exportfs: make ->encode_fh() a mandatory method for NFS export") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Amir Goldstein --- Miklos, I have queued up this fix. The regression has no serious impact on most users, because xino works pretty well either way. A nested overlayfs, where the lower overlayfs is nonsamefs ext4 would have less xino overflows, but this is a very corner case. Thanks, Amir. fs/overlayfs/util.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 3f1b763a8bb4c..2ea769f311c34 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -85,7 +85,10 @@ int ovl_can_decode_fh(struct super_block *sb) if (!exportfs_can_decode_fh(sb->s_export_op)) return 0; - return sb->s_export_op->encode_fh ? -1 : FILEID_INO32_GEN; + if (sb->s_export_op->encode_fh == generic_encode_ino32_fh) + return FILEID_INO32_GEN; + + return -1; } struct dentry *ovl_indexdir(struct super_block *sb) -- 2.53.0