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From:   Dai Ngo <dai.ngo@oracle.com>
To:     trondmy@hammerspace.com
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 1/1] NFSv4: nfs4_proc_set_acl needs to restore NFS_CAP_UIDGID_NOMAP on error.
Date:   Thu, 13 May 2021 14:35:55 -0400
Message-Id: <20210513183555.28230-1-dai.ngo@oracle.com>
MIME-Version: 1.0
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Precedence: bulk

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.

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
 #

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
---
 fs/nfs/nfs4proc.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c65c4b41e2c1..e12630e3bb7c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5926,13 +5926,20 @@ static int __nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t bufl
 static int nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t buflen)
 {
 	struct nfs4_exception exception = { };
-	int err;
+	struct nfs_server *server = NFS_SERVER(inode);
+	int err, nomap;
+
+	nomap = server->caps & NFS_CAP_UIDGID_NOMAP;
 	do {
 		err = __nfs4_proc_set_acl(inode, buf, buflen);
 		trace_nfs4_set_acl(inode, err);
 		err = nfs4_handle_exception(NFS_SERVER(inode), err,
 				&exception);
 	} while (exception.retry);
+
+	/* if retry still fails then restore NFS_CAP_UIDGID_NOMAP setting */
+	if (err && nomap)
+		server->caps |= NFS_CAP_UIDGID_NOMAP;
 	return err;
 }
 
-- 
2.9.5