fs: support RWF_NOWAIT for buffered reads

This is based on the old idea and code from Milosz Tanski.  With the aio
nowait code it becomes mostly trivial now.  Buffered writes continue to
return -EOPNOTSUPP if RWF_NOWAIT is passed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 0 insertions, 6 deletions

diff --git a/fs/aio.c b/fs/aio.c
index dcad3a66748c..d93daa076726 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1593,12 +1593,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 		goto out_put_req;
 	}
 
-	if ((req->common.ki_flags & IOCB_NOWAIT) &&
-			!(req->common.ki_flags & IOCB_DIRECT)) {
-		ret = -EOPNOTSUPP;
-		goto out_put_req;
-	}
-
 	ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
 	if (unlikely(ret)) {
 		pr_debug("EFAULT: aio_key\n");