[RFC PATCH 12/18] ceph: Convert some page arrays to ceph_databuf

[David Howells <dhowells@redhat.com>]

---
 drivers/block/rbd.c             | 12 +++---
 include/linux/ceph/osd_client.h |  3 ++
 net/ceph/osd_client.c           | 74 +++++++++++++++++++++------------
 3 files changed, 55 insertions(+), 34 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 1756973b696f..950b63eb41de 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2108,7 +2108,7 @@ static int rbd_obj_calc_img_extents(struct rbd_obj_request *obj_req,
 
 static int rbd_osd_setup_stat(struct ceph_osd_request *osd_req, int which)
 {
-	struct page **pages;
+	struct ceph_databuf *dbuf;
 
 	/*
 	 * The response data for a STAT call consists of:
@@ -2118,14 +2118,12 @@ static int rbd_osd_setup_stat(struct ceph_osd_request *osd_req, int which)
 	 *         le32 tv_nsec;
 	 *     } mtime;
 	 */
-	pages = ceph_alloc_page_vector(1, GFP_NOIO);
-	if (IS_ERR(pages))
-		return PTR_ERR(pages);
+	dbuf = ceph_databuf_alloc(1, 8 + sizeof(struct ceph_timespec), GFP_NOIO);
+	if (!dbuf)
+		return -ENOMEM;
 
 	osd_req_op_init(osd_req, which, CEPH_OSD_OP_STAT, 0);
-	osd_req_op_raw_data_in_pages(osd_req, which, pages,
-				     8 + sizeof(struct ceph_timespec),
-				     0, false, true);
+	osd_req_op_raw_data_in_databuf(osd_req, which, dbuf);
 	return 0;
 }
 
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index fd91c5d92600..fec78550d5ce 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -483,6 +483,9 @@ extern void osd_req_op_extent_osd_data_pages(struct ceph_osd_request *,
 					struct page **pages, u64 length,
 					u32 offset, bool pages_from_pool,
 					bool own_pages);
+void osd_req_op_raw_data_in_databuf(struct ceph_osd_request *osd_req,
+				    unsigned int which,
+				    struct ceph_databuf *databuf);
 extern void osd_req_op_extent_osd_data_pagelist(struct ceph_osd_request *,
 					unsigned int which,
 					struct ceph_pagelist *pagelist);
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 6bbd9fe780c3..c83ae9bb335e 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -181,6 +181,17 @@ osd_req_op_extent_osd_data(struct ceph_osd_request *osd_req,
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data);
 
+void osd_req_op_raw_data_in_databuf(struct ceph_osd_request *osd_req,
+				    unsigned int which,
+				    struct ceph_databuf *dbuf)
+{
+	struct ceph_osd_data *osd_data;
+
+	osd_data = osd_req_op_raw_data_in(osd_req, which);
+	ceph_osd_databuf_init(osd_data, dbuf);
+}
+EXPORT_SYMBOL(osd_req_op_raw_data_in_databuf);
+
 void osd_req_op_raw_data_in_pages(struct ceph_osd_request *osd_req,
 			unsigned int which, struct page **pages,
 			u64 length, u32 offset,
@@ -280,17 +291,16 @@ void osd_req_op_cls_request_data_pagelist(
 }
 EXPORT_SYMBOL(osd_req_op_cls_request_data_pagelist);
 
-static void osd_req_op_cls_request_data_pages(struct ceph_osd_request *osd_req,
-			unsigned int which, struct page **pages, u64 length,
-			u32 offset, bool pages_from_pool, bool own_pages)
+static void osd_req_op_cls_request_data_iter(
+			struct ceph_osd_request *osd_req,
+			unsigned int which, struct iov_iter *iter)
 {
 	struct ceph_osd_data *osd_data;
 
 	osd_data = osd_req_op_data(osd_req, which, cls, request_data);
-	ceph_osd_data_pages_init(osd_data, pages, length, offset,
-				pages_from_pool, own_pages);
-	osd_req->r_ops[which].cls.indata_len += length;
-	osd_req->r_ops[which].indata_len += length;
+	ceph_osd_iter_init(osd_data, iter);
+	osd_req->r_ops[which].cls.indata_len += iter->count;
+	osd_req->r_ops[which].indata_len += iter->count;
 }
 
 void osd_req_op_cls_response_databuf(struct ceph_osd_request *osd_req,
@@ -3017,10 +3027,12 @@ static void linger_commit_cb(struct ceph_osd_request *req)
 	if (!lreq->is_watch) {
 		struct ceph_osd_data *osd_data =
 		    osd_req_op_data(req, 0, notify, response_data);
-		void *p = page_address(osd_data->pages[0]);
+		void *p;
 
 		WARN_ON(req->r_ops[0].op != CEPH_OSD_OP_NOTIFY ||
-			osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
+			osd_data->type != CEPH_OSD_DATA_TYPE_PAGELIST);
+
+		p = kmap_ceph_databuf_page(osd_data->dbuf, 0);
 
 		/* make note of the notify_id */
 		if (req->r_ops[0].outdata_len >= sizeof(u64)) {
@@ -3030,6 +3042,8 @@ static void linger_commit_cb(struct ceph_osd_request *req)
 		} else {
 			dout("lreq %p no notify_id\n", lreq);
 		}
+
+		kunmap_local(p);
 	}
 
 out:
@@ -5032,7 +5046,7 @@ int ceph_osdc_list_watchers(struct ceph_osd_client *osdc,
 			    u32 *num_watchers)
 {
 	struct ceph_osd_request *req;
-	struct page **pages;
+	struct ceph_databuf *dbuf;
 	int ret;
 
 	req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
@@ -5043,16 +5057,16 @@ int ceph_osdc_list_watchers(struct ceph_osd_client *osdc,
 	ceph_oloc_copy(&req->r_base_oloc, oloc);
 	req->r_flags = CEPH_OSD_FLAG_READ;
 
-	pages = ceph_alloc_page_vector(1, GFP_NOIO);
-	if (IS_ERR(pages)) {
-		ret = PTR_ERR(pages);
+	dbuf = ceph_databuf_alloc(1, PAGE_SIZE, GFP_NOIO);
+	if (!dbuf) {
+		ret = -ENOMEM;
 		goto out_put_req;
 	}
 
 	osd_req_op_init(req, 0, CEPH_OSD_OP_LIST_WATCHERS, 0);
-	ceph_osd_data_pages_init(osd_req_op_data(req, 0, list_watchers,
-						 response_data),
-				 pages, PAGE_SIZE, 0, false, true);
+	ceph_osd_databuf_init(osd_req_op_data(req, 0, list_watchers,
+					      response_data),
+			      dbuf);
 
 	ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
 	if (ret)
@@ -5061,10 +5075,11 @@ int ceph_osdc_list_watchers(struct ceph_osd_client *osdc,
 	ceph_osdc_start_request(osdc, req);
 	ret = ceph_osdc_wait_request(osdc, req);
 	if (ret >= 0) {
-		void *p = page_address(pages[0]);
+		void *p = kmap_ceph_databuf_page(dbuf, 0);
 		void *const end = p + req->r_ops[0].outdata_len;
 
 		ret = decode_watchers(&p, end, watchers, num_watchers);
+		kunmap(p);
 	}
 
 out_put_req:
@@ -5111,6 +5126,8 @@ int ceph_osdc_call(struct ceph_osd_client *osdc,
 		   struct ceph_databuf *response)
 {
 	struct ceph_osd_request *req;
+	struct iov_iter iter;
+	struct bio_vec bv;
 	int ret;
 
 	if (req_len > PAGE_SIZE)
@@ -5128,9 +5145,11 @@ int ceph_osdc_call(struct ceph_osd_client *osdc,
 	if (ret)
 		goto out_put_req;
 
-	if (req_page)
-		osd_req_op_cls_request_data_pages(req, 0, &req_page, req_len,
-						  0, false, false);
+	if (req_page) {
+		bvec_set_page(&bv, req_page, 0, req_len);
+		iov_iter_bvec(&iter, ITER_SOURCE, &bv, 1, req_len);
+		osd_req_op_cls_request_data_iter(req, 0, &iter);
+	}
 	if (response)
 		osd_req_op_cls_response_databuf(req, 0, response);
 
@@ -5285,12 +5304,12 @@ int osd_req_op_copy_from_init(struct ceph_osd_request *req,
 			      u8 copy_from_flags)
 {
 	struct ceph_osd_req_op *op;
-	struct page **pages;
+	struct ceph_databuf *dbuf;
 	void *p, *end;
 
-	pages = ceph_alloc_page_vector(1, GFP_KERNEL);
-	if (IS_ERR(pages))
-		return PTR_ERR(pages);
+	dbuf = ceph_databuf_alloc(1, PAGE_SIZE, GFP_KERNEL);
+	if (!dbuf)
+		return -ENOMEM;
 
 	op = osd_req_op_init(req, 0, CEPH_OSD_OP_COPY_FROM2,
 			     dst_fadvise_flags);
@@ -5299,16 +5318,17 @@ int osd_req_op_copy_from_init(struct ceph_osd_request *req,
 	op->copy_from.flags = copy_from_flags;
 	op->copy_from.src_fadvise_flags = src_fadvise_flags;
 
-	p = page_address(pages[0]);
+	p = kmap_ceph_databuf_page(dbuf, 0);
 	end = p + PAGE_SIZE;
 	ceph_encode_string(&p, end, src_oid->name, src_oid->name_len);
 	encode_oloc(&p, end, src_oloc);
 	ceph_encode_32(&p, truncate_seq);
 	ceph_encode_64(&p, truncate_size);
 	op->indata_len = PAGE_SIZE - (end - p);
+	dbuf->length = op->indata_len;
+	kunmap_local(p);
 
-	ceph_osd_data_pages_init(&op->copy_from.osd_data, pages,
-				 op->indata_len, 0, false, true);
+	ceph_osd_databuf_init(&op->copy_from.osd_data, dbuf);
 	return 0;
 }
 EXPORT_SYMBOL(osd_req_op_copy_from_init);