From ad0fcd4eb68059de02e1766948263c71b8a5b1dc Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 23 Jul 2012 15:46:23 -0400 Subject: [PATCH] nfs: explicitly reject LOCK_MAND flock() requests We have no mechanism to emulate LOCK_MAND locks on NFSv4, so explicitly return -EINVAL if someone requests it. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust --- fs/nfs/file.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 1557978ca7b3..b039a17ee941 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -834,6 +834,15 @@ int nfs_flock(struct file *filp, int cmd, struct file_lock *fl) if (!(fl->fl_flags & FL_FLOCK)) return -ENOLCK; + /* + * The NFSv4 protocol doesn't support LOCK_MAND, which is not part of + * any standard. In principle we might be able to support LOCK_MAND + * on NFSv2/3 since NLMv3/4 support DOS share modes, but for now the + * NFS code is not set up for it. + */ + if (fl->fl_type & LOCK_MAND) + return -EINVAL; + if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK) is_local = 1; -- 2.39.5