[RFC PATCH 18/35] libceph, rbd: Convert some page arrays to ceph_databuf

[David Howells <dhowells@redhat.com>]

Convert some miscellaneous page arrays to ceph_databuf containers.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Viacheslav Dubeyko <slava@dubeyko.com>
cc: Alex Markuze <amarkuze@redhat.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: ceph-devel@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
---
 drivers/block/rbd.c             | 12 ++++-----
 include/linux/ceph/osd_client.h |  3 +++
 net/ceph/osd_client.c           | 43 +++++++++++++++++++++------------
 3 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 078bb1e3e1da..eea12c7ab2a0 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_reply_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 d31e59bd128c..6e126e212271 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -482,6 +482,9 @@ 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 b4adb299f9cd..64a06267e7b3 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -182,6 +182,17 @@ 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,
@@ -5000,7 +5011,7 @@ 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);
@@ -5011,16 +5022,16 @@ 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_reply_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)
@@ -5029,10 +5040,11 @@ 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:
@@ -5246,12 +5258,12 @@ 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_req_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);
@@ -5260,16 +5272,17 @@ 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, src_oid->name, src_oid->name_len);
 	encode_oloc(&p, src_oloc);
 	ceph_encode_32(&p, truncate_seq);
 	ceph_encode_64(&p, truncate_size);
 	op->indata_len = PAGE_SIZE - (end - p);
+	ceph_databuf_added_data(dbuf, 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);