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: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index e5c9853..91b7324 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -197,7 +197,7 @@
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 @@
* 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
*/
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 85d95ec..328ce80 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -3339,7 +3339,7 @@
[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+ [P_SUPERSEDED] = "Superseded",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",
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index d507700..afab66b 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -425,7 +425,7 @@
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 @@
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 @@
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 @@
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 @@
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 @@
"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 @@
!(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 @@
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 @@
[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 },
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 6776857..266ef24 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -611,13 +611,13 @@
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);
diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index 9611713..016de6b 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -97,7 +97,7 @@
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 */
