I'm going over the write code carefully preparing for wave4, and came
across some code I traced to this patch.
Why is this needed? Why doesn't the pg_bsize check in
nfs_pageio_do_add_request() prevent this from ever being invoked?
Fred
On Sat, Feb 20, 2010 at 4:06 PM, Benny Halevy <bhalevy@xxxxxxxxxxx> wrote:
> We coalesce pages based on the strip size that may be bigger
> than the server can handle in one write (and even exceed the
> maximum RPC message size on the server)
>
> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
> ---
> fs/nfs/nfs4proc.c | 7 +++++++
> fs/nfs/write.c | 8 ++++++++
> include/linux/nfs_xdr.h | 1 +
> 3 files changed, 16 insertions(+), 0 deletions(-)
>
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 8132a96..93b1963 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -3180,6 +3180,13 @@ static int pnfs4_write_done(struct rpc_task *task, struct nfs_write_data *data)
> struct nfs_client *client = mds_svr->nfs_client;
> int status = task->tk_status >= 0 ? 0 : task->tk_status;
>
> + /* restore original count after retry? */
> + if (data->pdata.orig_count) {
> + dprintk("%s: restoring original count %u\n", __func__,
> + data->pdata.orig_count);
> + data->args.count = data->pdata.orig_count;
> + }
> +
> if (data->pdata.pnfsflags & PNFS_NO_RPC)
> return 0;
>
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index 90ce78e..fee6f00 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -1108,6 +1108,14 @@ void nfs_write_prepare(struct rpc_task *task, void *calldata)
> #ifdef CONFIG_PNFS
> if (data->fldata.ds_nfs_client)
> clp = data->fldata.ds_nfs_client;
> + else if (data->args.count > NFS_SERVER(data->inode)->wsize) {
> + /* retrying via MDS? */
> + data->pdata.orig_count = data->args.count;
> + data->args.count = NFS_SERVER(data->inode)->wsize;
> + dprintk("%s: trimmed count %u to wsize %u\n", __func__,
> + data->pdata.orig_count, data->args.count);
> + } else
> + data->pdata.orig_count = 0;
> #endif /* CONFIG_PNFS */
>
> if (nfs4_setup_sequence(clp, &data->args.seq_args,
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index efc4ca0..13ccd48 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -970,6 +970,7 @@ struct nfs_page;
> struct pnfs_call_data {
> struct pnfs_layout_segment *lseg;
> const struct rpc_call_ops *call_ops;
> + u32 orig_count; /* for retry via MDS */
> int pnfs_error;
> u8 pnfsflags;
> u8 how; /* for FLUSH_STABLE */
> --
> 1.6.4.4
>
> _______________________________________________
> pNFS mailing list
> pNFS@xxxxxxxxxxxxx
> http://linux-nfs.org/cgi-bin/mailman/listinfo/pnfs
>
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