drbd: Remove unused extern declarations

Commit b411b363 ("The DRBD driver") declared but never implemented
drbd_read_remote(), is_valid_ar_handle() and drbd_set_recv_tcq().
And commit 668700b4 ("drbd: Create a dedicated workqueue for sending acks on the control connection")
never implemented drbd_send_ping_wf().

Commit 2451fc3b ("drbd: Removed the BIO_RW_BARRIER support form the receiver/epoch code")
leave w_e_reissue() declaration unused.

Commit 8fe60551 ("drbd: Rename drbdd_init() -> drbd_receiver()")
rename drbdd_init() and leave unsued declaration. Also drbd_asender() is removed in
commit 1c03e520 ("drbd: Rename asender to ack_receiver").
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20240802095147.2788218-1-yuehaibing@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/drbd/drbd_int.h

@@ -297,10 +297,6 @@ struct drbd_epoch {
 	unsigned long flags;
 };
 
-/* Prototype declaration of function defined in drbd_receiver.c */
-int drbdd_init(struct drbd_thread *);
-int drbd_asender(struct drbd_thread *);
-
 /* drbd_epoch flag bits */
 enum {
 	DE_HAVE_BARRIER_NUMBER,
@@ -1390,9 +1386,6 @@ extern void conn_free_crypto(struct drbd_connection *connection);
 extern void do_submit(struct work_struct *ws);
 extern void __drbd_make_request(struct drbd_device *, struct bio *);
 void drbd_submit_bio(struct bio *bio);
-extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req);
-extern int is_valid_ar_handle(struct drbd_request *, sector_t);
-
 
 /* drbd_nl.c */
 
@@ -1474,7 +1467,6 @@ extern int w_resync_timer(struct drbd_work *, int);
 extern int w_send_write_hint(struct drbd_work *, int);
 extern int w_send_dblock(struct drbd_work *, int);
 extern int w_send_read_req(struct drbd_work *, int);
-extern int w_e_reissue(struct drbd_work *, int);
 extern int w_restart_disk_io(struct drbd_work *, int);
 extern int w_send_out_of_sync(struct drbd_work *, int);
 
@@ -1488,7 +1480,6 @@ extern int drbd_issue_discard_or_zero_out(struct drbd_device *device,
 		sector_t start, unsigned int nr_sectors, int flags);
 extern int drbd_receiver(struct drbd_thread *thi);
 extern int drbd_ack_receiver(struct drbd_thread *thi);
-extern void drbd_send_ping_wf(struct work_struct *ws);
 extern void drbd_send_acks_wf(struct work_struct *ws);
 extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device);
 extern bool drbd_rs_should_slow_down(struct drbd_peer_device *peer_device, sector_t sector,
@@ -1504,7 +1495,6 @@ extern void __drbd_free_peer_req(struct drbd_device *, struct drbd_peer_request
 #define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0)
 #define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1)
 extern struct page *drbd_alloc_pages(struct drbd_peer_device *, unsigned int, bool);
-extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled);
 extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed);
 extern int drbd_connected(struct drbd_peer_device *);