Re: commit 1643b43fbd breaks open(.., O_RDONLY|O_CREAT, ...) on fuse.

[Al Viro <viro@ZenIV.linux.org.uk>]

On Tue, Jun 07, 2016 at 04:27:28PM +0800, Yan, Zheng wrote:
> If the file does not exist and the caller has no permission to create
> file, syscall open() should return -EACCESS. But on fuse mount of
> 4.7-rc2 kernel, open() return -ENOENT.

Does the following fix your reproducer?

diff --git a/fs/namei.c b/fs/namei.c
index d7c0cac..28cb1cd 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2995,9 +2995,13 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
 			}
 			if (*opened & FILE_CREATED)
 				fsnotify_create(dir, dentry);
-			path->dentry = dentry;
-			path->mnt = nd->path.mnt;
-			return 1;
+			if (unlikely(d_is_negative(dentry))) {
+				error = -ENOENT;
+			} else {
+				path->dentry = dentry;
+				path->mnt = nd->path.mnt;
+				return 1;
+			}
 		}
 	}
 	dput(dentry);