[RFC PATCH v11 41/51] libceph: allow ceph_osdc_new_request to accept a multi-op read

Jeff Layton
2022-03-22T14:15:05Z

Currently we have some special-casing for multi-op writes, but in the
case of a read, we can't really handle it. All of the current multi-op
callers call it with CEPH_OSD_FLAG_WRITE set.

Have ceph_osdc_new_request check for CEPH_OSD_FLAG_READ and if it's set,
allocate multiple reply ops instead of multiple request ops. If neither
flag is set, return -EINVAL.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
net/ceph/osd_client.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index b67c56ddade7..5df1450cd30f 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1130,15 +1130,30 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
if (flags & CEPH_OSD_FLAG_WRITE)
req->r_data_offset = off;

- if (num_ops > 1)
+ if (num_ops > 1) {
+ int num_req_ops, num_rep_ops;
+
/*
- * This is a special case for ceph_writepages_start(), but it
- * also covers ceph_uninline_data(). If more multi-op request
- * use cases emerge, we will need a separate helper.
+ * If this is a multi-op write request, assume that we'll need
+ * request ops. If it's a multi-op read then assume we'll need
+ * reply ops. Anything else and call it -EINVAL.
*/
- r = __ceph_osdc_alloc_messages(req, GFP_NOFS, num_ops, 0);
- else
+ if (flags & CEPH_OSD_FLAG_WRITE) {
+ num_req_ops = num_ops;
+ num_rep_ops = 0;
+ } else if (flags & CEPH_OSD_FLAG_READ) {
+ num_req_ops = 0;
+ num_rep_ops = num_ops;
+ } else {
+ r = -EINVAL;
+ goto fail;
+ }
+
+ r = __ceph_osdc_alloc_messages(req, GFP_NOFS, num_req_ops,
+ num_rep_ops);
+ } else {
r = ceph_osdc_alloc_messages(req, GFP_NOFS);
+ }
if (r)
goto fail;

--
2.35.1