rbd: combine rbd sync watch/unwatch functions

The rbd_req_sync_watch() and rbd_req_sync_unwatch() functions are nearly identical. Combine them into a single function with a flag indicating whether a watch is to be initiated or torn down.

---
 drivers/block/rbd.c |   81
+++++++++++++++++----------------------------------
 1 file changed, 27 insertions(+), 54 deletions(-)

index a2f9df7..e1094ff 100644
@@ -1434,74 +1434,48 @@ static void rbd_watch_cb(u64 ver, u64 notify_id,

u8 opcode, void *data)
}

/*
- * Request sync osd watch
+ * Request sync osd watch/unwatch. The value of "start" determines
+ * whether a watch request is being initiated or torn down. */
-static int rbd_req_sync_watch(struct rbd_device *rbd_dev) +static int rbd_req_sync_watch(struct rbd_device *rbd_dev, bool start)
{
struct ceph_osd_req_op *op;
- struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
+ struct ceph_osd_request **linger_req = NULL;
+ __le64 version = 0;
int ret;

op = rbd_create_rw_op(CEPH_OSD_OP_WATCH, 0); if (!op)
return -ENOMEM;

- ret = ceph_osdc_create_event(osdc, rbd_watch_cb, 0,
- (void *)rbd_dev, &rbd_dev->watch_event);
- if (ret < 0)
- goto fail;
-
- op->watch.ver = cpu_to_le64(rbd_dev->header.obj_version);
- op->watch.cookie = cpu_to_le64(rbd_dev->watch_event->cookie);
- op->watch.flag = 1;
-
- ret = rbd_req_sync_op(rbd_dev,

-			      CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
-			      op,
-			      rbd_dev->header_name,
-			      0, 0, NULL,
-			      &rbd_dev->watch_request, NULL);

-
- if (ret < 0)
- goto fail_event;
-
- rbd_destroy_op(op);
- return 0;
-
-fail_event:
- ceph_osdc_cancel_event(rbd_dev->watch_event);
- rbd_dev->watch_event = NULL;
-fail:
- rbd_destroy_op(op);
- return ret;
-}
-
-/*
- * Request sync osd unwatch
- */
-static int rbd_req_sync_unwatch(struct rbd_device *rbd_dev) -{
- struct ceph_osd_req_op *op;
- int ret;
+ if (start) {
+ struct ceph_osd_client *osdc;

- op = rbd_create_rw_op(CEPH_OSD_OP_WATCH, 0);
- if (!op)
- return -ENOMEM;
+ osdc = &rbd_dev->rbd_client->client->osdc;
+ ret = ceph_osdc_create_event(osdc, rbd_watch_cb, 0, rbd_dev,
+ &rbd_dev->watch_event);
+ if (ret < 0)
+ goto done;
+ version = cpu_to_le64(rbd_dev->header.obj_version);
+ linger_req = &rbd_dev->watch_request;
+ }

- op->watch.ver = 0;
+ op->watch.ver = version;
op->watch.cookie = cpu_to_le64(rbd_dev->watch_event->cookie);
- op->watch.flag = 0;
+ op->watch.flag = (u8) start;

ret = rbd_req_sync_op(rbd_dev,
CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,

-			      op,
-			      rbd_dev->header_name,
-			      0, 0, NULL, NULL, NULL);

-
+ op, rbd_dev->header_name,
+ 0, 0, NULL, linger_req, NULL);

+ if (!start || ret < 0) {
+ ceph_osdc_cancel_event(rbd_dev->watch_event);
+ rbd_dev->watch_event = NULL;
+ }
+done:
rbd_destroy_op(op);
- ceph_osdc_cancel_event(rbd_dev->watch_event);
- rbd_dev->watch_event = NULL;
+
return ret;
}

@@ -3018,7 +2992,7 @@ static int rbd_init_watch_dev(struct rbd_device *rbd_dev)
int ret, rc;

do {
- ret = rbd_req_sync_watch(rbd_dev);
+ ret = rbd_req_sync_watch(rbd_dev, true);
if (ret == -ERANGE) {
rc = rbd_dev_refresh(rbd_dev, NULL);
if (rc < 0)
@@ -3729,8 +3703,7 @@ static void rbd_dev_release(struct device *dev)
rbd_dev->watch_request);
}
if (rbd_dev->watch_event)
- rbd_req_sync_unwatch(rbd_dev);
-
+ rbd_req_sync_watch(rbd_dev, false);

/* clean up and free blkdev */
rbd_free_disk(rbd_dev);

1.7.9.5