On Sun, 2012-05-27 at 13:32 +0800, Peng Tao wrote:
> To allow layout driver specific preparation for DIO.
>
> Signed-off-by: Peng Tao <tao.peng@xxxxxxx>
> ---
> fs/nfs/direct.c | 43 +++++++++++++++++++++++++++++++++++++++----
> fs/nfs/pnfs.h | 38 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 77 insertions(+), 4 deletions(-)
>
> diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
> index ad2775d..8e9c8e1 100644
> --- a/fs/nfs/direct.c
> +++ b/fs/nfs/direct.c
> @@ -383,6 +383,37 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
> return result < 0 ? (ssize_t) result : -EFAULT;
> }
>
> +static void nfs_direct_read_init(struct nfs_pageio_descriptor *pgio,
> + struct inode *inode, const struct iovec *iov,
> + unsigned long nr_segs, loff_t pos,
> + struct blk_plug *plug)
> +{
> + if (pnfs_dio_begin(inode, iov, nr_segs, pos, plug))
> + pnfs_pageio_init_read(pgio, inode,
> + &nfs_direct_read_completion_ops);
> + else
> + nfs_pageio_init_read_mds(pgio, inode,
> + &nfs_direct_read_completion_ops);
> +}
> +
> +static void nfs_direct_write_init(struct nfs_pageio_descriptor *pgio,
> + struct inode *inode, const struct iovec *iov,
> + unsigned long nr_segs, loff_t pos,
> + struct blk_plug *plug)
> +{
> + if (pnfs_dio_begin(inode, iov, nr_segs, pos, plug))
> + pnfs_pageio_init_write(pgio, inode, FLUSH_COND_STABLE,
> + &nfs_direct_write_completion_ops);
> + else
> + nfs_pageio_init_write_mds(pgio, inode, FLUSH_COND_STABLE,
> + &nfs_direct_write_completion_ops);
> +}
> +
> +static void nfs_dio_end(struct inode *inode, struct blk_plug *plug)
> +{
> + pnfs_dio_end(inode, plug);
> +}
> +
> static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
> const struct iovec *iov,
> unsigned long nr_segs,
> @@ -392,9 +423,10 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
> ssize_t result = -EINVAL;
> size_t requested_bytes = 0;
> unsigned long seg;
> + struct blk_plug plug;
> +
> + nfs_direct_read_init(&desc, dreq->inode, iov, nr_segs, pos, &plug);
>
> - nfs_pageio_init_read(&desc, dreq->inode,
> - &nfs_direct_read_completion_ops);
> get_dreq(dreq);
> desc.pg_dreq = dreq;
>
> @@ -410,6 +442,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
> }
>
> nfs_pageio_complete(&desc);
> + nfs_dio_end(dreq->inode, &plug);
Why can't you just put this in pg_init/pg_doio? There is already a flag
in the nfs_pageio_descriptor that tells you if more i/o is due (see
pg_moreio).
There should be no need to add extra callbacks in the generic code for
any of this.
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
��.n��������+%������w��{.n�����{��w��� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
