From: Lars Ellenberg Date: Thu, 20 Mar 2014 10:19:22 +0000 (+0100) Subject: drbd: application writes may set-in-sync in protocol != C X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=08d0dabf48ccf55e310b8ae9381858b477cabe2e;p=deliverable%2Flinux.git 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: Philipp Reisner Signed-off-by: Lars Ellenberg --- diff --git a/drivers/block/drbd/drbd_interval.h b/drivers/block/drbd/drbd_interval.h index f38fcb00c10d..f210543f05f4 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 7c060243ae46..7ada5d363064 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 b89e6fb468c6..3a3c4893ea26 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 1ee735590b61..f07a724998ea 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;