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Commit d4dabbe2 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
Browse files

drbd: disambiguation, s/P_DISCARD_WRITE/P_SUPERSEDED/ 



To avoid confusion with REQ_DISCARD aka TRIM, rename our
"discard concurrent write acks" from P_DISCARD_WRITE to P_SUPERSEDED.

At the same time, rename the drbd request event DISCARD_WRITE
to CONFLICT_RESOLVED. It already triggers both successful completion
or restart of the request, depending on our RQ_POSTPONED flag.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent 232fd3f4

drivers/block/drbd/drbd_int.h

+2 −2
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ enum drbd_packet { 
	P_RECV_ACK	      = 0x15, /* Used in protocol B */

	P_WRITE_ACK	      = 0x16, /* Used in protocol C */

	P_RS_WRITE_ACK	      = 0x17, /* Is a P_WRITE_ACK, additionally call set_in_sync(). */

	P_DISCARD_WRITE	      = 0x18, /* Used in proto C, two-primaries conflict detection */

	P_SUPERSEDED	      = 0x18, /* Used in proto C, two-primaries conflict detection */

	P_NEG_ACK	      = 0x19, /* Sent if local disk is unusable */

	P_NEG_DREPLY	      = 0x1a, /* Local disk is broken... */

	P_NEG_RS_DREPLY	      = 0x1b, /* Local disk is broken... */
@@ -335,7 +335,7 @@ struct p_data { 
 * commands which share a struct:

 *  p_block_ack:

 *   P_RECV_ACK (proto B), P_WRITE_ACK (proto C),

 *   P_DISCARD_WRITE (proto C, two-primaries conflict detection)

 *   P_SUPERSEDED (proto C, two-primaries conflict detection)

 *  p_block_req:

 *   P_DATA_REQUEST, P_RS_DATA_REQUEST

 */

drivers/block/drbd/drbd_main.c

+1 −1
Original line number Diff line number Diff line
@@ -3339,7 +3339,7 @@ const char *cmdname(enum drbd_packet cmd) 
		[P_RECV_ACK]	        = "RecvAck",

		[P_WRITE_ACK]	        = "WriteAck",

		[P_RS_WRITE_ACK]	= "RSWriteAck",

		[P_DISCARD_WRITE]        = "DiscardWrite",

		[P_SUPERSEDED]          = "Superseded",

		[P_NEG_ACK]	        = "NegAck",

		[P_NEG_DREPLY]	        = "NegDReply",

		[P_NEG_RS_DREPLY]	= "NegRSDReply",

drivers/block/drbd/drbd_receiver.c

+17 −16
Original line number Diff line number Diff line
@@ -425,7 +425,7 @@ static int drbd_finish_peer_reqs(struct drbd_conf *mdev) 
		drbd_free_net_peer_req(mdev, peer_req);



	/* possible callbacks here:

	 * e_end_block, and e_end_resync_block, e_send_discard_write.

	 * e_end_block, and e_end_resync_block, e_send_superseded.

	 * all ignore the last argument.

	 */

	list_for_each_entry_safe(peer_req, t, &work_list, w.list) {
@@ -1803,7 +1803,7 @@ static void restart_conflicting_writes(struct drbd_conf *mdev, 
			continue;

		/* as it is RQ_POSTPONED, this will cause it to

		 * be queued on the retry workqueue. */

		__req_mod(req, DISCARD_WRITE, NULL);

		__req_mod(req, CONFLICT_RESOLVED, NULL);

	}

}
@@ -1864,9 +1864,9 @@ static int e_send_ack(struct drbd_work *w, enum drbd_packet ack) 
	return err;

}



static int e_send_discard_write(struct drbd_work *w, int unused)

static int e_send_superseded(struct drbd_work *w, int unused)

{

	return e_send_ack(w, P_DISCARD_WRITE);

	return e_send_ack(w, P_SUPERSEDED);

}



static int e_send_retry_write(struct drbd_work *w, int unused)
@@ -1874,7 +1874,7 @@ static int e_send_retry_write(struct drbd_work *w, int unused) 
	struct drbd_tconn *tconn = w->mdev->tconn;



	return e_send_ack(w, tconn->agreed_pro_version >= 100 ?

			     P_RETRY_WRITE : P_DISCARD_WRITE);

			     P_RETRY_WRITE : P_SUPERSEDED);

}



static bool seq_greater(u32 a, u32 b)
@@ -2082,11 +2082,11 @@ static int handle_write_conflicts(struct drbd_conf *mdev, 
		if (resolve_conflicts) {

			/*

			 * If the peer request is fully contained within the

			 * overlapping request, it can be discarded; otherwise,

			 * it will be retried once all overlapping requests

			 * have completed.

			 * overlapping request, it can be considered overwritten

			 * and thus superseded; otherwise, it will be retried

			 * once all overlapping requests have completed.

			 */

			bool discard = i->sector <= sector && i->sector +

			bool superseded = i->sector <= sector && i->sector +

				       (i->size >> 9) >= sector + (size >> 9);



			if (!equal)
@@ -2095,10 +2095,10 @@ static int handle_write_conflicts(struct drbd_conf *mdev, 
					       "assuming %s came first\n",

					  (unsigned long long)i->sector, i->size,

					  (unsigned long long)sector, size,

					  discard ? "local" : "remote");

					  superseded ? "local" : "remote");



			inc_unacked(mdev);

			peer_req->w.cb = discard ? e_send_discard_write :

			peer_req->w.cb = superseded ? e_send_superseded :

						   e_send_retry_write;

			list_add_tail(&peer_req->w.list, &mdev->done_ee);

			wake_asender(mdev->tconn);
@@ -2119,8 +2119,9 @@ static int handle_write_conflicts(struct drbd_conf *mdev, 
			    !(req->rq_state & RQ_POSTPONED)) {

				/*

				 * Wait for the node with the discard flag to

				 * decide if this request will be discarded or

				 * retried.  Requests that are discarded will

				 * decide if this request has been superseded

				 * or needs to be retried.

				 * Requests that have been superseded will

				 * disappear from the write_requests tree.

				 *

				 * In addition, wait for the conflicting
@@ -4994,8 +4995,8 @@ static int got_BlockAck(struct drbd_tconn *tconn, struct packet_info *pi) 
	case P_RECV_ACK:

		what = RECV_ACKED_BY_PEER;

		break;

	case P_DISCARD_WRITE:

		what = DISCARD_WRITE;

	case P_SUPERSEDED:

		what = CONFLICT_RESOLVED;

		break;

	case P_RETRY_WRITE:

		what = POSTPONE_WRITE;
@@ -5220,7 +5221,7 @@ static struct asender_cmd asender_tbl[] = { 
	[P_RECV_ACK]	    = { sizeof(struct p_block_ack), got_BlockAck },

	[P_WRITE_ACK]	    = { sizeof(struct p_block_ack), got_BlockAck },

	[P_RS_WRITE_ACK]    = { sizeof(struct p_block_ack), got_BlockAck },

	[P_DISCARD_WRITE]   = { sizeof(struct p_block_ack), got_BlockAck },

	[P_SUPERSEDED]   = { sizeof(struct p_block_ack), got_BlockAck },

	[P_NEG_ACK]	    = { sizeof(struct p_block_ack), got_NegAck },

	[P_NEG_DREPLY]	    = { sizeof(struct p_block_ack), got_NegDReply },

	[P_NEG_RS_DREPLY]   = { sizeof(struct p_block_ack), got_NegRSDReply },

drivers/block/drbd/drbd_req.c

+3 −3
Original line number Diff line number Diff line
@@ -611,13 +611,13 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, 
				RQ_NET_DONE);

		break;



	case DISCARD_WRITE:

		/* for discarded conflicting writes of multiple primaries,

	case CONFLICT_RESOLVED:

		/* for superseded conflicting writes of multiple primaries,

		 * there is no need to keep anything in the tl, potential

		 * node crashes are covered by the activity log.

		 *

		 * If this request had been marked as RQ_POSTPONED before,

		 * it will actually not be discarded, but "restarted",

		 * it will actually not be completed, but "restarted",

		 * resubmitted from the retry worker context. */

		D_ASSERT(req->rq_state & RQ_NET_PENDING);

		D_ASSERT(req->rq_state & RQ_EXP_WRITE_ACK);

drivers/block/drbd/drbd_req.h

+1 −1
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ enum drbd_req_event { 
	RECV_ACKED_BY_PEER,

	WRITE_ACKED_BY_PEER,

	WRITE_ACKED_BY_PEER_AND_SIS, /* and set_in_sync */

	DISCARD_WRITE,

	CONFLICT_RESOLVED,

	POSTPONE_WRITE,

	NEG_ACKED,

	BARRIER_ACKED, /* in protocol A and B */