All support is already there in the generic code, we just need to wire it up. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- fs/block_dev.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index a7df151f8aba..f50026ec00c7 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1739,6 +1739,8 @@ static int blkdev_open(struct inode * inode, struct file * filp) */ filp->f_flags |= O_LARGEFILE; + filp->f_mode |= FMODE_NOWAIT; + if (filp->f_flags & O_NDELAY) filp->f_mode |= FMODE_NDELAY; if (filp->f_flags & O_EXCL) @@ -1890,6 +1892,9 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) if (iocb->ki_pos >= size) return -ENOSPC; + if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT) == IOCB_NOWAIT) + return -EOPNOTSUPP; + iov_iter_truncate(from, size - iocb->ki_pos); blk_start_plug(&plug); -- 2.11.0