Commit 8b84de79 authored by Alex Elder's avatar Alex Elder
Browse files

rbd: assign watch request more directly 



Both rbd_req_sync_op() and rbd_do_request() have a "linger"
parameter, which is the address of a pointer that should refer to
the osd request structure used to issue a request to an osd.

Only one case ever supplies a non-null "linger" argument: an
CEPH_OSD_OP_WATCH start.  And in that one case it is assigned
&rbd_dev->watch_request.

Within rbd_do_request() (where the assignment ultimately gets made)
we know the rbd_dev and therefore its watch_request field.  We
also know whether the op being sent is CEPH_OSD_OP_WATCH start.

Stop opaquely passing down the "linger" pointer, and instead just
assign the value directly inside rbd_do_request() when it's needed.

This makes it unnecessary for rbd_req_sync_watch() to make
arrangements to hold a value that's not available until a
bit later.  This more clearly separates setting up a watch
request from submitting it.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 5efea49a

drivers/block/rbd.c

+8 −12
Original line number Diff line number Diff line
@@ -1158,7 +1158,6 @@ static int rbd_do_request(struct request *rq, 
			  int coll_index,

			  void (*rbd_cb)(struct ceph_osd_request *,

					 struct ceph_msg *),

			  struct ceph_osd_request **linger_req,

			  u64 *ver)

{

	struct ceph_osd_client *osdc;
@@ -1210,9 +1209,9 @@ static int rbd_do_request(struct request *rq, 
	ceph_osdc_build_request(osd_req, ofs, len, 1, op,

				snapc, snapid, &mtime);



	if (linger_req) {

	if (op->op == CEPH_OSD_OP_WATCH && op->watch.flag) {

		ceph_osdc_set_request_linger(osdc, osd_req);

		*linger_req = osd_req;

		rbd_dev->watch_request = osd_req;

	}



	ret = ceph_osdc_start_request(osdc, osd_req, false);
@@ -1296,7 +1295,6 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev, 
			   const char *object_name,

			   u64 ofs, u64 inbound_size,

			   char *inbound,

			   struct ceph_osd_request **linger_req,

			   u64 *ver)

{

	int ret;
@@ -1317,7 +1315,7 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev, 
			  op,

			  NULL, 0,

			  NULL,

			  linger_req, ver);

			  ver);

	if (ret < 0)

		goto done;
@@ -1383,7 +1381,7 @@ static int rbd_do_op(struct request *rq, 
			     flags,

			     op,

			     coll, coll_index,

			     rbd_req_cb, 0, NULL);

			     rbd_req_cb, NULL);

	if (ret < 0)

		rbd_coll_end_req_index(rq, coll, coll_index,

					(s32)ret, seg_len);
@@ -1410,7 +1408,7 @@ static int rbd_req_sync_read(struct rbd_device *rbd_dev, 
		return -ENOMEM;



	ret = rbd_req_sync_op(rbd_dev, CEPH_OSD_FLAG_READ,

			       op, object_name, ofs, len, buf, NULL, ver);

			       op, object_name, ofs, len, buf, ver);

	rbd_osd_req_op_destroy(op);



	return ret;
@@ -1436,7 +1434,7 @@ static int rbd_req_sync_notify_ack(struct rbd_device *rbd_dev, 
			  CEPH_OSD_FLAG_READ,

			  op,

			  NULL, 0,

			  rbd_simple_req_cb, 0, NULL);

			  rbd_simple_req_cb, NULL);



	rbd_osd_req_op_destroy(op);
@@ -1469,7 +1467,6 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data) 
 */

static int rbd_req_sync_watch(struct rbd_device *rbd_dev, int start)

{

	struct ceph_osd_request **linger_req = NULL;

	struct ceph_osd_req_op *op;

	int ret = 0;
@@ -1481,7 +1478,6 @@ static int rbd_req_sync_watch(struct rbd_device *rbd_dev, int start) 
						&rbd_dev->watch_event);

		if (ret < 0)

			return ret;

		linger_req = &rbd_dev->watch_request;

	} else {

		rbd_assert(rbd_dev->watch_request != NULL);

	}
@@ -1493,7 +1489,7 @@ static int rbd_req_sync_watch(struct rbd_device *rbd_dev, int start) 
		ret = rbd_req_sync_op(rbd_dev,

			      CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,

			      op, rbd_dev->header_name,

			      0, 0, NULL, linger_req, NULL);

			      0, 0, NULL, NULL);



	/* Cancel the event if we're tearing down, or on error */
@@ -1537,7 +1533,7 @@ static int rbd_req_sync_exec(struct rbd_device *rbd_dev, 


	ret = rbd_req_sync_op(rbd_dev, CEPH_OSD_FLAG_READ, op,

			       object_name, 0, inbound_size, inbound,

			       NULL, ver);

			       ver);



	rbd_osd_req_op_destroy(op);

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