libceph: combine initializing and setting osd data

This ends up being a rather large patch but what it's doing is
somewhat straightforward.

Basically, this is replacing two calls with one.  The first of the
two calls is initializing a struct ceph_osd_data with data (either a
page array, a page list, or a bio list); the second is setting an
osd request op so it associates that data with one of the op's
parameters.  In place of those two will be a single function that
initializes the op directly.

That means we sort of fan out a set of the needed functions:
    - extent ops with pages data
    - extent ops with pagelist data
    - extent ops with bio list data
and
    - class ops with page data for receiving a response

We also have define another one, but it's only used internally:
    - class ops with pagelist data for request parameters

Note that we *still* haven't gotten rid of the osd request's
r_data_in and r_data_out fields.  All the osd ops refer to them for
their data.  For now, these data fields are pointers assigned to the
appropriate r_data_* field when these new functions are called.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

2 files changed, 6 insertions, 9 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index cc57104..27d6207 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -245,7 +245,7 @@ static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg)
 	dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
 
 	/* unlock all pages, zeroing any data we didn't read */
-	osd_data = &req->r_data_in;
+	osd_data = osd_req_op_extent_osd_data(req, 0, false);
 	BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 	num_pages = calc_pages_for((u64)osd_data->alignment,
 					(u64)osd_data->length);
@@ -343,8 +343,7 @@ static int start_read(struct inode *inode, struct list_head *page_list, int max)
 		}
 		pages[i] = page;
 	}
-	BUG_ON(req->r_ops[0].extent.osd_data != &req->r_data_in);
-	ceph_osd_data_pages_init(req->r_ops[0].extent.osd_data, pages, len, 0,
+	osd_req_op_extent_osd_data_pages(req, 0, false, pages, len, 0,
 					false, false);
 	req->r_callback = finish_read;
 	req->r_inode = inode;
@@ -572,7 +571,7 @@ static void writepages_finish(struct ceph_osd_request *req,
 	long writeback_stat;
 	unsigned issued = ceph_caps_issued(ci);
 
-	osd_data = &req->r_data_out;
+	osd_data = osd_req_op_extent_osd_data(req, 0, true);
 	BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 	num_pages = calc_pages_for((u64)osd_data->alignment,
 					(u64)osd_data->length);
@@ -917,9 +916,8 @@ get_more_pages:
 		dout("writepages got %d pages at %llu~%llu\n",
 		     locked_pages, offset, len);
 
-		BUG_ON(req->r_ops[0].extent.osd_data != &req->r_data_out);
-		ceph_osd_data_pages_init(req->r_ops[0].extent.osd_data, pages,
-						len, 0, !!pool, false);
+		osd_req_op_extent_osd_data_pages(req, 0, true, pages, len, 0,
+							!!pool, false);
 
 		pages = NULL;	/* request message now owns the pages array */
 		pool = NULL;
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index cddc10f..0f9c409 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -574,8 +574,7 @@ more:
 			own_pages = true;
 		}
 	}
-	BUG_ON(req->r_ops[0].extent.osd_data != &req->r_data_out);
-	ceph_osd_data_pages_init(req->r_ops[0].extent.osd_data, pages, len,
+	osd_req_op_extent_osd_data_pages(req, 0, true, pages, len,
 					page_align, false, own_pages);
 
 	/* BUG_ON(vino.snap != CEPH_NOSNAP); */