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Message-Id: <1404231410-29852-10-git-send-email-philipp.reisner@linbit.com>
Date: Tue, 1 Jul 2014 18:16:39 +0200
From: Philipp Reisner <philipp.reisner@...bit.com>
To: linux-kernel@...r.kernel.org, Jens Axboe <axboe@...nel.dk>
Cc: drbd-dev@...ts.linbit.com
Subject: [PATCH 09/20] drbd: application writes may set-in-sync in protocol != C
From: Lars Ellenberg <lars.ellenberg@...bit.com>
If "dirty" blocks are written to during resync,
that brings them in-sync.
By explicitly requesting write-acks during resync even in protocol != C,
we now can actually respect this.
Signed-off-by: Philipp Reisner <philipp.reisner@...bit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@...bit.com>
---
drivers/block/drbd/drbd_interval.h | 4 ++-
drivers/block/drbd/drbd_main.c | 5 ++-
drivers/block/drbd/drbd_receiver.c | 3 ++
drivers/block/drbd/drbd_req.c | 68 ++++++++++++++++++++++----------------
4 files changed, 49 insertions(+), 31 deletions(-)
diff --git a/drivers/block/drbd/drbd_interval.h b/drivers/block/drbd/drbd_interval.h
index f38fcb0..f210543 100644
--- a/drivers/block/drbd/drbd_interval.h
+++ b/drivers/block/drbd/drbd_interval.h
@@ -10,7 +10,9 @@ struct drbd_interval {
unsigned int size; /* size in bytes */
sector_t end; /* highest interval end in subtree */
int local:1 /* local or remote request? */;
- int waiting:1;
+ int waiting:1; /* someone is waiting for this to complete */
+ int completed:1; /* this has been completed already;
+ * ignore for conflict detection */
};
static inline void drbd_clear_interval(struct drbd_interval *i)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 7c06024..7ada5d3 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1639,7 +1639,10 @@ int drbd_send_dblock(struct drbd_peer_device *peer_device, struct drbd_request *
if (peer_device->connection->agreed_pro_version >= 100) {
if (req->rq_state & RQ_EXP_RECEIVE_ACK)
dp_flags |= DP_SEND_RECEIVE_ACK;
- if (req->rq_state & RQ_EXP_WRITE_ACK)
+ /* During resync, request an explicit write ack,
+ * even in protocol != C */
+ if (req->rq_state & RQ_EXP_WRITE_ACK
+ || (dp_flags & DP_MAY_SET_IN_SYNC))
dp_flags |= DP_SEND_WRITE_ACK;
}
p->dp_flags = cpu_to_be32(dp_flags);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index b89e6fb..3a3c489 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1930,6 +1930,7 @@ static int e_end_block(struct drbd_work *w, int cancel)
}
dec_unacked(device);
}
+
/* we delete from the conflict detection hash _after_ we sent out the
* P_WRITE_ACK / P_NEG_ACK, to get the sequence number right. */
if (peer_req->flags & EE_IN_INTERVAL_TREE) {
@@ -2156,6 +2157,8 @@ static int handle_write_conflicts(struct drbd_device *device,
drbd_for_each_overlap(i, &device->write_requests, sector, size) {
if (i == &peer_req->i)
continue;
+ if (i->completed)
+ continue;
if (!i->local) {
/*
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 1ee7355..f07a724 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -92,6 +92,19 @@ static struct drbd_request *drbd_req_new(struct drbd_device *device,
return req;
}
+static void drbd_remove_request_interval(struct rb_root *root,
+ struct drbd_request *req)
+{
+ struct drbd_device *device = req->device;
+ struct drbd_interval *i = &req->i;
+
+ drbd_remove_interval(root, i);
+
+ /* Wake up any processes waiting for this request to complete. */
+ if (i->waiting)
+ wake_up(&device->misc_wait);
+}
+
void drbd_req_destroy(struct kref *kref)
{
struct drbd_request *req = container_of(kref, struct drbd_request, kref);
@@ -115,6 +128,20 @@ void drbd_req_destroy(struct kref *kref)
* here unconditionally */
list_del_init(&req->tl_requests);
+ /* finally remove the request from the conflict detection
+ * respective block_id verification interval tree. */
+ if (!drbd_interval_empty(&req->i)) {
+ struct rb_root *root;
+
+ if (s & RQ_WRITE)
+ root = &device->write_requests;
+ else
+ root = &device->read_requests;
+ drbd_remove_request_interval(root, req);
+ } else if (s & (RQ_NET_MASK & ~RQ_NET_DONE) && req->i.size != 0)
+ drbd_err(device, "drbd_req_destroy: Logic BUG: interval empty, but: rq_state=0x%x, sect=%llu, size=%u\n",
+ s, (unsigned long long)req->i.sector, req->i.size);
+
/* if it was a write, we may have to set the corresponding
* bit(s) out-of-sync first. If it had a local part, we need to
* release the reference to the activity log. */
@@ -188,19 +215,6 @@ void complete_master_bio(struct drbd_device *device,
}
-static void drbd_remove_request_interval(struct rb_root *root,
- struct drbd_request *req)
-{
- struct drbd_device *device = req->device;
- struct drbd_interval *i = &req->i;
-
- drbd_remove_interval(root, i);
-
- /* Wake up any processes waiting for this request to complete. */
- if (i->waiting)
- wake_up(&device->misc_wait);
-}
-
/* Helper for __req_mod().
* Set m->bio to the master bio, if it is fit to be completed,
* or leave it alone (it is initialized to NULL in __req_mod),
@@ -254,18 +268,6 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m)
ok = (s & RQ_LOCAL_OK) || (s & RQ_NET_OK);
error = PTR_ERR(req->private_bio);
- /* remove the request from the conflict detection
- * respective block_id verification hash */
- if (!drbd_interval_empty(&req->i)) {
- struct rb_root *root;
-
- if (rw == WRITE)
- root = &device->write_requests;
- else
- root = &device->read_requests;
- drbd_remove_request_interval(root, req);
- }
-
/* Before we can signal completion to the upper layers,
* we may need to close the current transfer log epoch.
* We are within the request lock, so we can simply compare
@@ -301,7 +303,15 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m)
m->error = ok ? 0 : (error ?: -EIO);
m->bio = req->master_bio;
req->master_bio = NULL;
+ /* We leave it in the tree, to be able to verify later
+ * write-acks in protocol != C during resync.
+ * But we mark it as "complete", so it won't be counted as
+ * conflict in a multi-primary setup. */
+ req->i.completed = true;
}
+
+ if (req->i.waiting)
+ wake_up(&device->misc_wait);
}
static int drbd_req_put_completion_ref(struct drbd_request *req, struct bio_and_error *m, int put)
@@ -660,12 +670,13 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
case WRITE_ACKED_BY_PEER_AND_SIS:
req->rq_state |= RQ_NET_SIS;
case WRITE_ACKED_BY_PEER:
- D_ASSERT(device, req->rq_state & RQ_EXP_WRITE_ACK);
- /* protocol C; successfully written on peer.
+ /* Normal operation protocol C: successfully written on peer.
+ * During resync, even in protocol != C,
+ * we requested an explicit write ack anyways.
+ * Which means we cannot even assert anything here.
* Nothing more to do here.
* We want to keep the tl in place for all protocols, to cater
* for volatile write-back caches on lower level devices. */
-
goto ack_common;
case RECV_ACKED_BY_PEER:
D_ASSERT(device, req->rq_state & RQ_EXP_RECEIVE_ACK);
@@ -673,7 +684,6 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
* see also notes above in HANDED_OVER_TO_NETWORK about
* protocol != C */
ack_common:
- D_ASSERT(device, req->rq_state & RQ_NET_PENDING);
mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK);
break;
--
1.9.1
--
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