libceph: keep source rather than message osd op array

An osd request keeps a pointer to the osd operations (ops) array
that it builds in its request message.

In order to allow each op in the array to have its own distinct
data, we will need to keep track of each op's data, and that
information does not go over the wire.

As long as we're tracking the data we might as well just track the
entire (source) op definition for each of the ops.  And if we're
doing that, we'll have no more need to keep a pointer to the
wire-encoded version.

This patch makes the array of source ops be kept with the osd
request structure, and uses that instead of the version encoded in
the message in places where that was previously used.  The array
will be embedded in the request structure, and the maximum number of
ops we ever actually use is currently 2.  So reduce CEPH_OSD_MAX_OP
to 2 to reduce the size of the structure.

The result of doing this sort of ripples back up, and as a result
various function parameters and local variables become unnecessary.

Make r_num_ops be unsigned, and move the definition of struct
ceph_osd_req_op earlier to ensure it's defined where needed.

It does not yet add per-op data, that's coming soon.

This resolves:
    http://tracker.ceph.com/issues/4656

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

1 files changed, 34 insertions, 36 deletions

diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index af60dac1f9c0..f4c1a2a22a14 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -48,7 +48,7 @@ struct ceph_osd {
 };
 
 
-#define CEPH_OSD_MAX_OP 10
+#define CEPH_OSD_MAX_OP 2
 
 enum ceph_osd_data_type {
         CEPH_OSD_DATA_TYPE_NONE,
@@ -79,6 +79,34 @@ struct ceph_osd_data {
         };
 };
 
+struct ceph_osd_req_op {
+        u16 op;           /* CEPH_OSD_OP_* */
+        u32 payload_len;
+        union {
+                struct {
+                        u64 offset, length;
+                        u64 truncate_size;
+                        u32 truncate_seq;
+                } extent;
+                struct {
+                        const char *class_name;
+                        const char *method_name;
+                        const void *indata;
+                        u32 indata_len;
+                        __u8 class_len;
+                        __u8 method_len;
+                        __u8 argc;
+                } cls;
+                struct {
+                        u64 cookie;
+                        u64 ver;
+                        u32 prot_ver;
+                        u32 timeout;
+                        __u8 flag;
+                } watch;
+        };
+};
+
 /* an in-flight request */
 struct ceph_osd_request {
         u64             r_tid;              /* unique for this client */
@@ -95,10 +123,11 @@ struct ceph_osd_request {
         struct ceph_msg  *r_request, *r_reply;
         int               r_flags;     /* any additional flags for the osd */
         u32               r_sent;      /* >0 if r_request is sending/sent */
-        int               r_num_ops;
 
-        /* encoded message content */
-        struct ceph_osd_op *r_request_ops;
+        /* request osd ops array  */
+        unsigned int            r_num_ops;
+        struct ceph_osd_req_op  r_ops[CEPH_OSD_MAX_OP];
+
         /* these are updated on each send */
         __le32           *r_request_osdmap_epoch;
         __le32           *r_request_flags;
@@ -193,34 +222,6 @@ struct ceph_osd_client {
         struct workqueue_struct *notify_wq;
 };
 
-struct ceph_osd_req_op {
-        u16 op;           /* CEPH_OSD_OP_* */
-        u32 payload_len;
-        union {
-                struct {
-                        u64 offset, length;
-                        u64 truncate_size;
-                        u32 truncate_seq;
-                } extent;
-                struct {
-                        const char *class_name;
-                        const char *method_name;
-                        const void *indata;
-                        u32 indata_len;
-                        __u8 class_len;
-                        __u8 method_len;
-                        __u8 argc;
-                } cls;
-                struct {
-                        u64 cookie;
-                        u64 ver;
-                        u32 prot_ver;
-                        u32 timeout;
-                        __u8 flag;
-                } watch;
-        };
-};
-
 extern int ceph_osdc_init(struct ceph_osd_client *osdc,
                           struct ceph_client *client);
 extern void ceph_osdc_stop(struct ceph_osd_client *osdc);
@@ -249,8 +250,6 @@ extern struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *
                                                gfp_t gfp_flags);
 
 extern void ceph_osdc_build_request(struct ceph_osd_request *req, u64 off,
-                                    unsigned int num_ops,
-                                    struct ceph_osd_req_op *src_ops,
                                     struct ceph_snap_context *snapc,
                                     u64 snap_id,
                                     struct timespec *mtime);
@@ -259,8 +258,7 @@ extern struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *,
                                       struct ceph_file_layout *layout,
                                       struct ceph_vino vino,
                                       u64 offset, u64 *len,
-                                      int num_ops, struct ceph_osd_req_op *ops,
-                                      int opcode, int flags,
+                                      int num_ops, int opcode, int flags,
                                       struct ceph_snap_context *snapc,
                                       u32 truncate_seq, u64 truncate_size,
                                       bool use_mempool);