[PATCH AUTOSEL 5.4 34/37] nfs: we don't support removing system.nfs4_acl

Sasha Levin
2021-03-17T01:02:35Z

From: "J. Bruce Fields" <bfields@redhat.com>

[ Upstream commit 4f8be1f53bf615102d103c0509ffa9596f65b718 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4proc.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 30e44b33040a..fa181c3ba5cd 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5754,6 +5754,9 @@ 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))
--
2.30.1