[pnfs] [PATCH 22/28] pnfs: pnfs_modify_new_request

[Benny Halevy]

On Mar. 11, 2008, 21:32 +0200, Fred Isaman <iisaman at citi.umich.edu> wrote:
> Add hook into nfs_page initialization to allow for setup of wb_private,
> and any other nfs_page fields that need twiddling.
> 
> Signed-off-by: Fred Isaman <iisaman at citi.umich.edu>
> ---
>  fs/nfs/pagelist.c         |    3 +++
>  fs/nfs/pnfs.c             |   20 ++++++++++++++++++++
>  fs/nfs/pnfs.h             |    2 ++
>  include/linux/nfs4_pnfs.h |    4 ++++
>  4 files changed, 29 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
> index 624083e..c49b59b 100644
> --- a/fs/nfs/pagelist.c
> +++ b/fs/nfs/pagelist.c
> @@ -90,6 +90,9 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
>  	req->wb_bytes   = count;
>  	req->wb_context = get_nfs_open_context(ctx);
>  	kref_init(&req->wb_kref);
> +#ifdef CONFIG_PNFS
> +	pnfs_modify_new_request(inode, req, fsdata);
> +#endif /* CONFIG_PNFS */

Please define a no-op version for the !defined(CONFIG_PNFS) case
and invoke unconditionally.

>  	return req;
>  }
>  
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index a4db86e..4c4927f 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -1928,6 +1928,26 @@ out_unlock:
>  	goto out;
>  }
>  
> +void pnfs_modify_new_request(struct inode *inode, struct nfs_page *req,
> +			     void *fsdata)
> +{
> +	struct nfs_server *nfss = NFS_SERVER(inode);
> +	struct pnfs_layout_segment *lseg = NULL;
> +	loff_t pos;
> +	unsigned count;
> +
> +	if (!nfss->pnfs_curr_ld || !nfss->pnfs_curr_ld->ld_io_ops ||
> +	    !nfss->pnfs_curr_ld->ld_io_ops->new_request)
> +		return;

this should be done at the inline wrapper.

> +
> +	pos = ((loff_t)req->wb_index << PAGE_CACHE_SHIFT) + req->wb_offset;
> +	count = req->wb_bytes;
> +	lseg = pnfs_find_get_lseg(inode, pos, count, IOMODE_RW);
> +	nfss->pnfs_curr_ld->ld_io_ops->new_request(lseg, req, pos, count,
> +						   fsdata);
> +	put_lseg(lseg);
> +}
> +
>  void pnfs_free_request_data(struct nfs_page *req)
>  {
>  	struct layoutdriver_io_operations *lo;
> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
> index 3860e38..9824f78 100644
> --- a/fs/nfs/pnfs.h
> +++ b/fs/nfs/pnfs.h
> @@ -48,6 +48,8 @@ void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *, struc
>  void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *);
>  void pnfs_update_layout_commit(struct inode *, struct list_head *, pgoff_t, unsigned int);
>  int pnfs_flush_one(struct inode *, struct list_head *, unsigned int, size_t, int);
> +void pnfs_modify_new_request(struct inode *inode, struct nfs_page *req,
> +			     void *fsdata);
>  void pnfs_free_request_data(struct nfs_page *req);
>  void pnfs_free_fsdata(void *fsdata);
>  ssize_t pnfs_file_write(struct file *, const char __user *, size_t, loff_t *);
> diff --git a/include/linux/nfs4_pnfs.h b/include/linux/nfs4_pnfs.h
> index 308a9fb..000e9eb 100644
> --- a/include/linux/nfs4_pnfs.h
> +++ b/include/linux/nfs4_pnfs.h
> @@ -141,6 +141,10 @@ struct layoutdriver_io_operations {
>  	int (*write_begin) (struct pnfs_layout_segment *lseg, struct page *page,
>  			    loff_t pos, unsigned count,
>  			    struct pnfs_fsdata **fsdata);
> +	/* Hook into nfs_create_request, for setting wb_private */
> +	void (*new_request)(struct pnfs_layout_segment *lseg,
> +			    struct nfs_page *req, loff_t pos, unsigned count,
> +			    struct pnfs_fsdata *fsdata);
>  	void (*free_request_data) (struct nfs_page *);
>  	void (*free_fsdata) (struct pnfs_fsdata *data);
>