[PATCH AUTOSEL 4.4 1/3] NFSv4: nfs4_proc_set_acl needs to restore NFS_CAP_UIDGID_NOMAP on error.

Sasha Levin
2021-06-15T15:54:09Z

From: Dai Ngo <dai.ngo@oracle.com>

[ Upstream commit f8849e206ef52b584cd9227255f4724f0cc900bb ]

Currently if __nfs4_proc_set_acl fails with NFS4ERR_BADOWNER it
re-enables the idmapper by clearing NFS_CAP_UIDGID_NOMAP before
retrying again. The NFS_CAP_UIDGID_NOMAP remains cleared even if
the retry fails. This causes problem for subsequent setattr
requests for v4 server that does not have idmapping configured.

This patch modifies nfs4_proc_set_acl to detect NFS4ERR_BADOWNER
and NFS4ERR_BADNAME and skips the retry, since the kernel isn't
involved in encoding the ACEs, and return -EINVAL.

Steps to reproduce the problem:

# mount -o vers=4.1,sec=sys server:/export/test /tmp/mnt
# touch /tmp/mnt/file1
# chown 99 /tmp/mnt/file1
# nfs4_setfacl -a A::unknown.user@xyz.com:wrtncy /tmp/mnt/file1
Failed setxattr operation: Invalid argument
# chown 99 /tmp/mnt/file1
chown: changing ownership of ‘/tmp/mnt/file1’: Invalid argument
# umount /tmp/mnt
# mount -o vers=4.1,sec=sys server:/export/test /tmp/mnt
# chown 99 /tmp/mnt/file1
#

v2: detect NFS4ERR_BADOWNER and NFS4ERR_BADNAME and skip retry
in nfs4_proc_set_acl.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs4proc.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 92ca753723b5..e10bada12361 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4887,6 +4887,14 @@ static int nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t buflen
do {
err = __nfs4_proc_set_acl(inode, buf, buflen);
trace_nfs4_set_acl(inode, err);
+ if (err == -NFS4ERR_BADOWNER || err == -NFS4ERR_BADNAME) {
+ /*
+ * no need to retry since the kernel
+ * isn't involved in encoding the ACEs.
+ */
+ err = -EINVAL;
+ break;
+ }
err = nfs4_handle_exception(NFS_SERVER(inode), err,
&exception);
} while (exception.retry);
--
2.30.2