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Commit 08d0dabf authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
Browse files

drbd: application writes may set-in-sync in protocol != C 



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: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent 5d0b17f1

drivers/block/drbd/drbd_interval.h

+3 −1
Original line number Diff line number Diff line
@@ -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)

drivers/block/drbd/drbd_main.c

+4 −1
Original line number Diff line number Diff line
@@ -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);

drivers/block/drbd/drbd_receiver.c

+3 −0
Original line number Diff line number Diff line
@@ -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) {

			/*

drivers/block/drbd/drbd_req.c

+39 −29
Original line number Diff line number Diff line
@@ -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;