NFSv4: fix open failure with O_ACCMODE flag
[ Upstream commit
b243874f6f9568b2daf1a00e9222cacdc15e159c ]
open() with O_ACCMODE|O_DIRECT flags secondly will fail.
Reproducer:
1. mount -t nfs -o vers=4.2 $server_ip:/ /mnt/
2. fd = open("/mnt/file", O_ACCMODE|O_DIRECT|O_CREAT)
3. close(fd)
4. fd = open("/mnt/file", O_ACCMODE|O_DIRECT)
Server nfsd4_decode_share_access() will fail with error nfserr_bad_xdr when
client use incorrect share access mode of 0.
Fix this by using NFS4_SHARE_ACCESS_BOTH share access mode in client,
just like firstly opening.
Fixes:
ce4ef7c0a8a05 ("NFS: Split out NFS v4 file operations")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>