libceph: define source request op functions

The rbd code has a function that allocates and populates a
ceph_osd_req_op structure (the in-core version of an osd request
operation).  When reviewed, Josh suggested two things: that the
big varargs function might be better split into type-specific
functions; and that this functionality really belongs in the osd
client rather than rbd.

This patch implements both of Josh's suggestions.  It breaks
up the rbd function into separate functions and defines them
in the osd client module as exported interfaces.  Unlike the
rbd version, however, the functions don't allocate an osd_req_op
structure; they are provided the address of one and that is
initialized instead.

The rbd function has been eliminated and calls to it have been
replaced by calls to the new routines.  The rbd code now now use a
stack (struct) variable to hold the op rather than allocating and
freeing it each time.

For now only the capabilities used by rbd are implemented.
Implementing all the other osd op types, and making the rest of the
code use it will be done separately, in the next few patches.

Note that only the extent, cls, and watch portions of the
ceph_osd_req_op structure are currently used.  Delete the others
(xattr, pgls, and snap) from its definition so nobody thinks it's
actually implemented or needed.  We can add it back again later
if needed, when we know it's been tested.

This (and a few follow-on patches) resolves:
    http://tracker.ceph.com/issues/3861

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

1 files changed, 11 insertions, 15 deletions

diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index 1dab291b2dc..5fd2cbfcfd9 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -202,14 +202,6 @@ struct ceph_osd_req_op {
 			u32 truncate_seq;
 		} extent;
 		struct {
-			const char *name;
-			const void *val;
-			u32 name_len;
-			u32 value_len;
-			__u8 cmp_op;       /* CEPH_OSD_CMPXATTR_OP_* */
-			__u8 cmp_mode;     /* CEPH_OSD_CMPXATTR_MODE_* */
-		} xattr;
-		struct {
 			const char *class_name;
 			const char *method_name;
 			const void *indata;
@@ -220,13 +212,6 @@ struct ceph_osd_req_op {
 		} cls;
 		struct {
 			u64 cookie;
-			u64 count;
-		} pgls;
-	        struct {
-		        u64 snapid;
-	        } snap;
-		struct {
-			u64 cookie;
 			u64 ver;
 			u32 prot_ver;
 			u32 timeout;
@@ -244,6 +229,17 @@ extern void ceph_osdc_handle_reply(struct ceph_osd_client *osdc,
 extern void ceph_osdc_handle_map(struct ceph_osd_client *osdc,
 				 struct ceph_msg *msg);
 
+extern void osd_req_op_init(struct ceph_osd_req_op *op, u16 opcode);
+extern void osd_req_op_extent_init(struct ceph_osd_req_op *op, u16 opcode,
+					u64 offset, u64 length,
+					u64 truncate_size, u32 truncate_seq);
+extern void osd_req_op_cls_init(struct ceph_osd_req_op *op, u16 opcode,
+					const char *class, const char *method,
+					const void *request_data,
+					size_t request_data_size);
+extern void osd_req_op_watch_init(struct ceph_osd_req_op *op, u16 opcode,
+					u64 cookie, u64 version, int flag);
+
 extern struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
 					       struct ceph_snap_context *snapc,
 					       unsigned int num_op,