nfs: we don't support removing system.nfs4_acl

The NFSv4 protocol doesn't have any notion of reomoving an attribute, so
removexattr(path,"system.nfs4_acl") doesn't make sense.

There's no documented return value.  Arguably it could be EOPNOTSUPP but
I'm a little worried an application might take that to mean that we
don't support ACLs or xattrs.  How about EINVAL?

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1002c4f66f3fa3bf1ed124a692209bda0a3cb3cc..c65c4b41e2c191dc05e875c070630ab588de63cd 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5889,6 +5889,9 @@ static int __nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t bufl
        unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE);
        int ret, i;
 
+       /* You can't remove system.nfs4_acl: */
+       if (buflen == 0)
+               return -EINVAL;
        if (!nfs4_server_supports_acls(server))
                return -EOPNOTSUPP;
        if (npages > ARRAY_SIZE(pages))