[PATCH v2 06/14] vfs: add some allowed open flags to vfs_lookup_open()

[NeilBrown <neilb@ownmail.net>]

From: NeilBrown <neil@brown.name>

vfs_lookup_open() must allow:
  O_LARGEFILE so that large files can be opened.
  O_NONBLOCK so that break_lease() can be asked to return -EWOULDBLOCK.

Also O_NOFOLLOW as we don't/can't handle symlinks.  In fact we
should enforce O_NOFOLLOW for the same reason we enforce __O_REGULAR.

Signed-off-by: NeilBrown <neil@brown.name>
---
 fs/namei.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 0f69abb3743b..a08f37aca3e1 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4632,11 +4632,12 @@ struct file *vfs_lookup_open(struct path *parent, struct qstr *last,
 	int error = 0;
 
 	WARN_ONCE(mode & ~S_IALLUGO, "mode must only have permission bits");
-	WARN_ONCE(open_flag & ~(O_ACCMODE|O_CREAT|O_EXCL|O_TRUNC|__O_REGULAR),
+	WARN_ONCE(open_flag & ~(O_ACCMODE|O_CREAT|O_EXCL|O_TRUNC|__O_REGULAR|
+				O_NONBLOCK|O_LARGEFILE|O_NOFOLLOW),
 		  "open_flag has unsupported flags");
 
 	mode |= S_IFREG;
-	open_flag |= __O_REGULAR;
+	open_flag |= __O_REGULAR | O_NOFOLLOW;
 
 	error = lookup_noperm_common(last, parent->dentry);
 	if (error)
-- 
2.50.0.107.gf914562f5916.dirty