In the not too distant past, the VFS ACL infrastructure would return -EOPNOTSUPP on filesystems (like NFS) that set SB_POSIXACL but that don't supply a get_acl or get_inode_acl method. On more recent kernels this returns -ENODATA, which breaks one method of detecting when ACLs are supported. Fix __get_acl to also check whether the inode has a "get_(inode_)?acl" method and to just return -EOPNOTSUPP if not. Reported-by: Ondrej Valousek <ondrej.valousek.xm@xxxxxxxxxxx> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> --- This patch is another approach to fixing this issue. I don't care too much either way which approach we take, but this may fix the problem for other filesystems too. Should we take a belt and suspenders approach here and fix it in both places? --- fs/posix_acl.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/posix_acl.c b/fs/posix_acl.c index a05fe94970ce..4c7c62040c43 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -130,8 +130,12 @@ static struct posix_acl *__get_acl(struct mnt_idmap *idmap, if (!is_uncached_acl(acl)) return acl; - if (!IS_POSIXACL(inode)) - return NULL; + /* + * NB: checking this after checking for a cached ACL allows tmpfs + * (which doesn't specify a get_acl operation) to work properly. + */ + if (!IS_POSIXACL(inode) || (!inode->i_op->get_acl && !inode->i_op->get_inode_acl)) + return ERR_PTR(-EOPNOTSUPP); sentinel = uncached_acl_sentinel(current); p = acl_by_type(inode, type); --- base-commit: a48fa7efaf1161c1c898931fe4c7f0070964233a change-id: 20230908-acl-fix-6f8f86930f32 Best regards, -- Jeff Layton <jlayton@xxxxxxxxxx>
