Re: [RFC PATCH v1 21/57] sunrpc: Remove PAGE_SIZE compile-time constant assumption

[Ryan Roberts <ryan.roberts@arm.com>]

+ Chuck Lever, Jeff Layton

This was a rather tricky series to get the recipients correct for and my script
did not realize that "supporter" was a pseudonym for "maintainer" so you were
missed off the original post. Appologies!

More context in cover letter:
https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/


On 14/10/2024 11:58, Ryan Roberts wrote:
> To prepare for supporting boot-time page size selection, refactor code
> to remove assumptions about PAGE_SIZE being compile-time constant. Code
> intended to be equivalent when compile-time page size is active.
> 
> Updated array sizes in various structs to contain enough entries for the
> smallest supported page size.
> 
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
> 
> ***NOTE***
> Any confused maintainers may want to read the cover note here for context:
> https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/
> 
>  include/linux/sunrpc/svc.h      | 8 +++++---
>  include/linux/sunrpc/svc_rdma.h | 4 ++--
>  include/linux/sunrpc/svcsock.h  | 2 +-
>  3 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
> index a7d0406b9ef59..dda44018b8f36 100644
> --- a/include/linux/sunrpc/svc.h
> +++ b/include/linux/sunrpc/svc.h
> @@ -160,6 +160,8 @@ extern u32 svc_max_payload(const struct svc_rqst *rqstp);
>   */
>  #define RPCSVC_MAXPAGES		((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \
>  				+ 2 + 1)
> +#define RPCSVC_MAXPAGES_MAX	((RPCSVC_MAXPAYLOAD+PAGE_SIZE_MIN-1)/PAGE_SIZE_MIN \
> +				+ 2 + 1)
>  
>  /*
>   * The context of a single thread, including the request currently being
> @@ -190,14 +192,14 @@ struct svc_rqst {
>  	struct xdr_stream	rq_res_stream;
>  	struct page		*rq_scratch_page;
>  	struct xdr_buf		rq_res;
> -	struct page		*rq_pages[RPCSVC_MAXPAGES + 1];
> +	struct page		*rq_pages[RPCSVC_MAXPAGES_MAX + 1];
>  	struct page *		*rq_respages;	/* points into rq_pages */
>  	struct page *		*rq_next_page; /* next reply page to use */
>  	struct page *		*rq_page_end;  /* one past the last page */
>  
>  	struct folio_batch	rq_fbatch;
> -	struct kvec		rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
> -	struct bio_vec		rq_bvec[RPCSVC_MAXPAGES];
> +	struct kvec		rq_vec[RPCSVC_MAXPAGES_MAX]; /* generally useful.. */
> +	struct bio_vec		rq_bvec[RPCSVC_MAXPAGES_MAX];
>  
>  	__be32			rq_xid;		/* transmission id */
>  	u32			rq_prog;	/* program number */
> diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
> index d33bab33099ab..7c6441e8d6f7a 100644
> --- a/include/linux/sunrpc/svc_rdma.h
> +++ b/include/linux/sunrpc/svc_rdma.h
> @@ -200,7 +200,7 @@ struct svc_rdma_recv_ctxt {
>  	struct svc_rdma_pcl	rc_reply_pcl;
>  
>  	unsigned int		rc_page_count;
> -	struct page		*rc_pages[RPCSVC_MAXPAGES];
> +	struct page		*rc_pages[RPCSVC_MAXPAGES_MAX];
>  };
>  
>  /*
> @@ -242,7 +242,7 @@ struct svc_rdma_send_ctxt {
>  	void			*sc_xprt_buf;
>  	int			sc_page_count;
>  	int			sc_cur_sge_no;
> -	struct page		*sc_pages[RPCSVC_MAXPAGES];
> +	struct page		*sc_pages[RPCSVC_MAXPAGES_MAX];
>  	struct ib_sge		sc_sges[];
>  };
>  
> diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
> index 7c78ec6356b92..6c6bcc82685a3 100644
> --- a/include/linux/sunrpc/svcsock.h
> +++ b/include/linux/sunrpc/svcsock.h
> @@ -40,7 +40,7 @@ struct svc_sock {
>  
>  	struct completion	sk_handshake_done;
>  
> -	struct page *		sk_pages[RPCSVC_MAXPAGES];	/* received data */
> +	struct page *		sk_pages[RPCSVC_MAXPAGES_MAX];	/* received data */
>  };
>  
>  static inline u32 svc_sock_reclen(struct svc_sock *svsk)