libceph: distinguish page and bio requests

An osd request uses either pages or a bio list for its data.  Use a
union to record information about the two, and add a data type
tag to select between them.

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

1 files changed, 36 insertions, 20 deletions

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 1f8c7a7..591e1b0 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -122,7 +122,8 @@ void ceph_osdc_release_request(struct kref *kref)
 	}
 	if (req->r_reply)
 		ceph_msg_put(req->r_reply);
-	if (req->r_data.own_pages)
+	if (req->r_data.type == CEPH_OSD_DATA_TYPE_PAGES &&
+			req->r_data.own_pages)
 		ceph_release_page_vector(req->r_data.pages,
 					 req->r_data.num_pages);
 	ceph_put_snap_context(req->r_snapc);
@@ -188,6 +189,7 @@ struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
 	}
 	req->r_reply = msg;
 
+	req->r_data.type = CEPH_OSD_DATA_TYPE_NONE;
 	ceph_pagelist_init(&req->r_trail);
 
 	/* create request message; allow space for oid */
@@ -1739,12 +1741,17 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc,
 {
 	int rc = 0;
 
-	req->r_request->pages = req->r_data.pages;
-	req->r_request->page_count = req->r_data.num_pages;
-	req->r_request->page_alignment = req->r_data.alignment;
+	if (req->r_data.type == CEPH_OSD_DATA_TYPE_PAGES) {
+		req->r_request->pages = req->r_data.pages;
+		req->r_request->page_count = req->r_data.num_pages;
+		req->r_request->page_alignment = req->r_data.alignment;
 #ifdef CONFIG_BLOCK
-	req->r_request->bio = req->r_data.bio;
+	} else if (req->r_data.type == CEPH_OSD_DATA_TYPE_BIO) {
+		req->r_request->bio = req->r_data.bio;
 #endif
+	} else {
+		pr_err("unknown request data type %d\n", req->r_data.type);
+	}
 	req->r_request->trail = &req->r_trail;
 
 	register_request(osdc, req);
@@ -1944,6 +1951,7 @@ int ceph_osdc_readpages(struct ceph_osd_client *osdc,
 		return PTR_ERR(req);
 
 	/* it may be a short read due to an object boundary */
+	req->r_data.type = CEPH_OSD_DATA_TYPE_PAGES;
 	req->r_data.pages = pages;
 	req->r_data.num_pages = calc_pages_for(page_align, *plen);
 	req->r_data.alignment = page_align;
@@ -1987,6 +1995,7 @@ int ceph_osdc_writepages(struct ceph_osd_client *osdc, struct ceph_vino vino,
 		return PTR_ERR(req);
 
 	/* it may be a short write due to an object boundary */
+	req->r_data.type = CEPH_OSD_DATA_TYPE_PAGES;
 	req->r_data.pages = pages;
 	req->r_data.num_pages = calc_pages_for(page_align, len);
 	req->r_data.alignment = page_align;
@@ -2083,23 +2092,30 @@ static struct ceph_msg *get_reply(struct ceph_connection *con,
 	m = ceph_msg_get(req->r_reply);
 
 	if (data_len > 0) {
-		int want = calc_pages_for(req->r_data.alignment, data_len);
-
-		if (req->r_data.pages && unlikely(req->r_data.num_pages < want)) {
-			pr_warning("tid %lld reply has %d bytes %d pages, we"
-				   " had only %d pages ready\n", tid, data_len,
-				   want, req->r_data.num_pages);
-			*skip = 1;
-			ceph_msg_put(m);
-			m = NULL;
-			goto out;
-		}
-		m->pages = req->r_data.pages;
-		m->page_count = req->r_data.num_pages;
-		m->page_alignment = req->r_data.alignment;
+		if (req->r_data.type == CEPH_OSD_DATA_TYPE_PAGES) {
+			int want;
+
+			want = calc_pages_for(req->r_data.alignment, data_len);
+			if (req->r_data.pages &&
+				unlikely(req->r_data.num_pages < want)) {
+
+				pr_warning("tid %lld reply has %d bytes %d "
+					"pages, we had only %d pages ready\n",
+					tid, data_len, want,
+					req->r_data.num_pages);
+				*skip = 1;
+				ceph_msg_put(m);
+				m = NULL;
+				goto out;
+			}
+			m->pages = req->r_data.pages;
+			m->page_count = req->r_data.num_pages;
+			m->page_alignment = req->r_data.alignment;
 #ifdef CONFIG_BLOCK
-		m->bio = req->r_data.bio;
+		} else if (req->r_data.type == CEPH_OSD_DATA_TYPE_BIO) {
+			m->bio = req->r_data.bio;
 #endif
+		}
 	}
 	*skip = 0;
 	req->r_con_filling_msg = con->ops->get(con);