Re: [PATCH] NFS: Revert pnfs ugliness from the generic NFS read code path

Benny Halevy
2011-11-14T11:12:52Z

On 2011-11-10 21:38, Trond Myklebust wrote:
> pNFS-specific code belongs in the pnfs layer. It should not be
> hijacking generic NFS read or write code paths.
>
> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
> ---
> fs/nfs/internal.h | 2 ++
> fs/nfs/pnfs.c | 26 +++++++++++++++++++++-----
> fs/nfs/read.c | 14 ++------------
> 3 files changed, 25 insertions(+), 17 deletions(-)
>
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index c1a1bd8..3f4d957 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -299,6 +299,8 @@ extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
> extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
> struct list_head *head);
>
> +extern void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
> + struct inode *inode);
> extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
> extern void nfs_readdata_release(struct nfs_read_data *rdata);
>
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index baf7353..8e672a2 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -1260,6 +1260,25 @@ pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
> }
> EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
>
> +static void pnfs_ld_handle_read_error(struct nfs_read_data *data)
> +{
> + struct nfs_pageio_descriptor pgio;
> +
> + put_lseg(data->lseg);
> + data->lseg = NULL;
> + dprintk("pnfs write error = %d\n", data->pnfs_error);

should be "read error", might as well fix this while you're at it :)

> +
> + nfs_pageio_init_read_mds(&pgio, data->inode);
> +
> + while (!list_empty(&data->pages)) {
> + struct nfs_page *req = nfs_list_entry(data->pages.next);
> +
> + nfs_list_remove_request(req);
> + nfs_pageio_add_request(&pgio, req);
> + }

What about pgio.pg_recoalesce?

Benny

> + nfs_pageio_complete(&pgio);
> +}
> +
> /*
> * Called by non rpc-based layout drivers
> */
> @@ -1268,11 +1287,8 @@ void pnfs_ld_read_done(struct nfs_read_data *data)
> if (likely(!data->pnfs_error)) {
> __nfs4_read_done_cb(data);
> data->mds_ops->rpc_call_done(&data->task, data);
> - } else {
> - put_lseg(data->lseg);
> - data->lseg = NULL;
> - dprintk("pnfs write error = %d\n", data->pnfs_error);
> - }
> + } else
> + pnfs_ld_handle_read_error(data);
> data->mds_ops->rpc_release(data);
> }
> EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index 8b48ec6..cfa175c 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -109,7 +109,7 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
> }
> }
>
> -static void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
> +void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
> struct inode *inode)
> {
> nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops,
> @@ -534,23 +534,13 @@ static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
> static void nfs_readpage_release_full(void *calldata)
> {
> struct nfs_read_data *data = calldata;
> - struct nfs_pageio_descriptor pgio;
>
> - if (data->pnfs_error) {
> - nfs_pageio_init_read_mds(&pgio, data->inode);
> - pgio.pg_recoalesce = 1;
> - }
> while (!list_empty(&data->pages)) {
> struct nfs_page *req = nfs_list_entry(data->pages.next);
>
> nfs_list_remove_request(req);
> - if (!data->pnfs_error)
> - nfs_readpage_release(req);
> - else
> - nfs_pageio_add_request(&pgio, req);
> + nfs_readpage_release(req);
> }
> - if (data->pnfs_error)
> - nfs_pageio_complete(&pgio);
> nfs_readdata_release(calldata);
> }
>