rbd: don't assign extent info in rbd_req_sync_op()

Move the assignment of the extent offset and length and payload
length out of rbd_req_sync_op() and into its caller in the one spot
where a read (and note--no write) operation might be initiated.

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

1 files changed, 46 insertions, 26 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index c6917b11800b..235cda083137 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1025,19 +1025,15 @@ out_err:
         return NULL;
 }
 
-static struct ceph_osd_req_op *rbd_create_rw_op(int opcode, u32 payload_len)
+static struct ceph_osd_req_op *rbd_create_rw_op(int opcode, u64 ofs, u64 len)
 {
         struct ceph_osd_req_op *op;
 
         op = kzalloc(sizeof (*op), GFP_NOIO);
         if (!op)
                 return NULL;
-        /*
-         * op extent offset and length will be set later on
-         * after ceph_calc_file_object_mapping().
-         */
+
         op->op = opcode;
-        op->payload_len = payload_len;
 
         return op;
 }
@@ -1047,6 +1043,42 @@ static void rbd_destroy_op(struct ceph_osd_req_op *op)
         kfree(op);
 }
 
+struct ceph_osd_req_op *rbd_osd_req_op_create(u16 opcode, ...)
+{
+        struct ceph_osd_req_op *op;
+        va_list args;
+
+        op = kzalloc(sizeof (*op), GFP_NOIO);
+        if (!op)
+                return NULL;
+        op->op = opcode;
+        va_start(args, opcode);
+        switch (opcode) {
+        case CEPH_OSD_OP_READ:
+        case CEPH_OSD_OP_WRITE:
+                /* rbd_osd_req_op_create(READ, offset, length) */
+                /* rbd_osd_req_op_create(WRITE, offset, length) */
+                op->extent.offset = va_arg(args, u64);
+                op->extent.length = va_arg(args, u64);
+                if (opcode == CEPH_OSD_OP_WRITE)
+                        op->payload_len = op->extent.length;
+                break;
+        default:
+                rbd_warn(NULL, "unsupported opcode %hu\n", opcode);
+                kfree(op);
+                op = NULL;
+                break;
+        }
+        va_end(args);
+
+        return op;
+}
+
+static void rbd_osd_req_op_destroy(struct ceph_osd_req_op *op)
+{
+        kfree(op);
+}
+
 static void rbd_coll_end_req_index(struct request *rq,
                                    struct rbd_req_coll *coll,
                                    int index,
@@ -1262,13 +1294,6 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev,
         if (IS_ERR(pages))
                 return PTR_ERR(pages);
 
-        if (op->op == CEPH_OSD_OP_READ || op->op == CEPH_OSD_OP_WRITE) {
-                op->extent.offset = ofs;
-                op->extent.length = inbound_size;
-                if (op->op == CEPH_OSD_OP_WRITE)
-                        op->payload_len = inbound_size;
-        }
-
         ret = rbd_do_request(NULL, rbd_dev, NULL, CEPH_NOSNAP,
                           object_name, ofs, inbound_size, NULL,
                           pages, num_pages,
@@ -1304,7 +1329,6 @@ static int rbd_do_op(struct request *rq,
         u64 seg_len;
         int ret;
         struct ceph_osd_req_op *op;
-        u32 payload_len;
         int opcode;
         int flags;
         u64 snapid;
@@ -1319,22 +1343,17 @@ static int rbd_do_op(struct request *rq,
                 opcode = CEPH_OSD_OP_WRITE;
                 flags = CEPH_OSD_FLAG_WRITE|CEPH_OSD_FLAG_ONDISK;
                 snapid = CEPH_NOSNAP;
-                payload_len = seg_len;
         } else {
                 opcode = CEPH_OSD_OP_READ;
                 flags = CEPH_OSD_FLAG_READ;
                 rbd_assert(!snapc);
                 snapid = rbd_dev->spec->snap_id;
-                payload_len = 0;
         }
 
         ret = -ENOMEM;
-        op = rbd_create_rw_op(opcode, payload_len);
+        op = rbd_osd_req_op_create(opcode, seg_ofs, seg_len);
         if (!op)
                 goto done;
-        op->extent.offset = seg_ofs;
-        op->extent.length = seg_len;
-        op->payload_len = payload_len;
 
         /* we've taken care of segment sizes earlier when we
            cloned the bios. We should never have a segment
@@ -1352,7 +1371,7 @@ static int rbd_do_op(struct request *rq,
         if (ret < 0)
                 rbd_coll_end_req_index(rq, coll, coll_index,
                                         (s32)ret, seg_len);
-        rbd_destroy_op(op);
+        rbd_osd_req_op_destroy(op);
 done:
         kfree(seg_name);
         return ret;
@@ -1370,13 +1389,13 @@ static int rbd_req_sync_read(struct rbd_device *rbd_dev,
         struct ceph_osd_req_op *op;
         int ret;
 
-        op = rbd_create_rw_op(CEPH_OSD_OP_READ, 0);
+        op = rbd_osd_req_op_create(CEPH_OSD_OP_READ, ofs, len);
         if (!op)
                 return -ENOMEM;
 
         ret = rbd_req_sync_op(rbd_dev, CEPH_OSD_FLAG_READ,
                                op, object_name, ofs, len, buf, NULL, ver);
-        rbd_destroy_op(op);
+        rbd_osd_req_op_destroy(op);
 
         return ret;
 }
@@ -1391,7 +1410,7 @@ static int rbd_req_sync_notify_ack(struct rbd_device *rbd_dev,
         struct ceph_osd_req_op *op;
         int ret;
 
-        op = rbd_create_rw_op(CEPH_OSD_OP_NOTIFY_ACK, 0);
+        op = rbd_create_rw_op(CEPH_OSD_OP_NOTIFY_ACK, 0, 0);
         if (!op)
                 return -ENOMEM;
 
@@ -1442,7 +1461,7 @@ static int rbd_req_sync_watch(struct rbd_device *rbd_dev, int start)
         __le64 version = 0;
         int ret;
 
-        op = rbd_create_rw_op(CEPH_OSD_OP_WATCH, 0);
+        op = rbd_create_rw_op(CEPH_OSD_OP_WATCH, 0, 0);
         if (!op)
                 return -ENOMEM;
 
@@ -1505,9 +1524,10 @@ static int rbd_req_sync_exec(struct rbd_device *rbd_dev,
          * operation.
          */
         payload_size = class_name_len + method_name_len + outbound_size;
-        op = rbd_create_rw_op(CEPH_OSD_OP_CALL, payload_size);
+        op = rbd_create_rw_op(CEPH_OSD_OP_CALL, 0, 0);
         if (!op)
                 return -ENOMEM;
+        op->payload_len = payload_size;
 
         op->cls.class_name = class_name;
         op->cls.class_len = (__u8) class_name_len;