Re: [Patch v2 15/15] CIFS: Add direct I/O functions to file_operations

[Pavel Shilovsky]

2018-05-30 12:48 GMT-07:00 Long Li <longli@xxxxxxxxxxxxxxxxx>:
> From: Long Li <longli@xxxxxxxxxxxxx>
>
> With direct read/write functions implemented, add them to file_operations.
> When mounting with "cache=none", CIFS uses direct I/O.
>
> Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> ---
>  fs/cifs/cifsfs.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index 62f1662..e84f8c2 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -1113,9 +1113,8 @@ const struct file_operations cifs_file_strict_ops = {
>  };
>
>  const struct file_operations cifs_file_direct_ops = {
> -       /* BB reevaluate whether they can be done with directio, no cache */
> -       .read_iter = cifs_user_readv,
> -       .write_iter = cifs_user_writev,
> +       .read_iter = cifs_direct_readv,
> +       .write_iter = cifs_direct_writev,

I would postpone making this change until we have asynchronous I/O
support for direct mode.

--
Best regards,
Pavel Shilovsky