fuse: allow kernel to access "direct_io" files

Allow the kernel read and write on "direct_io" files.  This is
necessary for nfs export and execute support.

The implementation is simple: if an access from the kernel is
detected, don't perform get_user_pages(), just use the kernel address
provided by the requester to copy from/to the userspace filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 06da05261e0..8b8eebc5614 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1032,6 +1032,7 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
 		fuse_put_request(fc, req);
 		return -ENOMEM;
 	}
+	req->out.argpages = 1;
 	req->num_pages = 1;
 	req->pages[0] = page;
 	fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR);