Re: [PATCH 03/16] libceph: add ceph_osdc_call() single-page helper

From: Alex Elder <elder@ieee.org>
To: Ilya Dryomov <idryomov@gmail.com>, ceph-devel@vger.kernel.org
Subject: Re: [PATCH 03/16] libceph: add ceph_osdc_call() single-page helper
Date: Wed, 24 Aug 2016 14:37:58 -0500	[thread overview]
Message-ID: <d390f0ef-e8d1-d619-3c1f-41d626f84d2f@ieee.org> (raw)
In-Reply-To: <1472044720-29116-4-git-send-email-idryomov@gmail.com>

On 08/24/2016 08:18 AM, Ilya Dryomov wrote:
> From: Douglas Fuller <dfuller@redhat.com>
> 
> Add a convenience function to osd_client to send Ceph OSD
> 'class' ops. The interface assumes that the request and
> reply data each consist of single pages.

Looks good.

Reviewed-by: Alex Elder <elder@linaro.org>

> Signed-off-by: Douglas Fuller <dfuller@redhat.com>
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
> ---
>  include/linux/ceph/osd_client.h |  8 +++++++
>  net/ceph/osd_client.c           | 51 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 59 insertions(+)
> 
> diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
> index 19821a191732..96337b15a60d 100644
> --- a/include/linux/ceph/osd_client.h
> +++ b/include/linux/ceph/osd_client.h
> @@ -397,6 +397,14 @@ extern void ceph_osdc_sync(struct ceph_osd_client *osdc);
>  extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc);
>  void ceph_osdc_maybe_request_map(struct ceph_osd_client *osdc);
>  
> +int ceph_osdc_call(struct ceph_osd_client *osdc,
> +		   struct ceph_object_id *oid,
> +		   struct ceph_object_locator *oloc,
> +		   const char *class, const char *method,
> +		   unsigned int flags,
> +		   struct page *req_page, size_t req_len,
> +		   struct page *resp_page, size_t *resp_len);
> +
>  extern int ceph_osdc_readpages(struct ceph_osd_client *osdc,
>  			       struct ceph_vino vino,
>  			       struct ceph_file_layout *layout,
> diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
> index dd51ec8ce97f..fbc6b7090c65 100644
> --- a/net/ceph/osd_client.c
> +++ b/net/ceph/osd_client.c
> @@ -4027,6 +4027,57 @@ void ceph_osdc_maybe_request_map(struct ceph_osd_client *osdc)
>  EXPORT_SYMBOL(ceph_osdc_maybe_request_map);
>  
>  /*
> + * Execute an OSD class method on an object.
> + *
> + * @flags: CEPH_OSD_FLAG_*
> + * @resp_len: out param for reply length
> + */
> +int ceph_osdc_call(struct ceph_osd_client *osdc,
> +		   struct ceph_object_id *oid,
> +		   struct ceph_object_locator *oloc,
> +		   const char *class, const char *method,
> +		   unsigned int flags,
> +		   struct page *req_page, size_t req_len,
> +		   struct page *resp_page, size_t *resp_len)
> +{
> +	struct ceph_osd_request *req;
> +	int ret;
> +
> +	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
> +	if (!req)
> +		return -ENOMEM;
> +
> +	ceph_oid_copy(&req->r_base_oid, oid);
> +	ceph_oloc_copy(&req->r_base_oloc, oloc);
> +	req->r_flags = flags;
> +
> +	ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
> +	if (ret)
> +		goto out_put_req;
> +
> +	osd_req_op_cls_init(req, 0, CEPH_OSD_OP_CALL, class, method);
> +	if (req_page)
> +		osd_req_op_cls_request_data_pages(req, 0, &req_page, req_len,
> +						  0, false, false);
> +	if (resp_page)
> +		osd_req_op_cls_response_data_pages(req, 0, &resp_page,
> +						   PAGE_SIZE, 0, false, false);
> +
> +	ceph_osdc_start_request(osdc, req, false);
> +	ret = ceph_osdc_wait_request(osdc, req);
> +	if (ret >= 0) {
> +		ret = req->r_ops[0].rval;
> +		if (resp_page)
> +			*resp_len = req->r_ops[0].outdata_len;
> +	}
> +
> +out_put_req:
> +	ceph_osdc_put_request(req);
> +	return ret;
> +}
> +EXPORT_SYMBOL(ceph_osdc_call);
> +
> +/*
>   * init, shutdown
>   */
>  int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
> 