diff options
Diffstat (limited to 'drivers/block/drbd/drbd_req.c')
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 147 |
1 files changed, 117 insertions, 30 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 3ae2c0086563..2255dcfebd2b 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -453,12 +453,12 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, kref_get(&req->kref); /* wait for the DONE */ if (!(s & RQ_NET_SENT) && (set & RQ_NET_SENT)) { - /* potentially already completed in the asender thread */ + /* potentially already completed in the ack_receiver thread */ if (!(s & RQ_NET_DONE)) { atomic_add(req->i.size >> 9, &device->ap_in_flight); set_if_null_req_not_net_done(peer_device, req); } - if (s & RQ_NET_PENDING) + if (req->rq_state & RQ_NET_PENDING) set_if_null_req_ack_pending(peer_device, req); } @@ -1095,6 +1095,24 @@ static bool do_remote_read(struct drbd_request *req) return false; } +bool drbd_should_do_remote(union drbd_dev_state s) +{ + return s.pdsk == D_UP_TO_DATE || + (s.pdsk >= D_INCONSISTENT && + s.conn >= C_WF_BITMAP_T && + s.conn < C_AHEAD); + /* Before proto 96 that was >= CONNECTED instead of >= C_WF_BITMAP_T. + That is equivalent since before 96 IO was frozen in the C_WF_BITMAP* + states. */ +} + +static bool drbd_should_send_out_of_sync(union drbd_dev_state s) +{ + return s.conn == C_AHEAD || s.conn == C_WF_BITMAP_S; + /* pdsk = D_INCONSISTENT as a consequence. Protocol 96 check not necessary + since we enter state C_AHEAD only if proto >= 96 */ +} + /* returns number of connections (== 1, for drbd 8.4) * expected to actually write this data, * which does NOT include those that we are L_AHEAD for. */ @@ -1149,7 +1167,6 @@ drbd_submit_req_private_bio(struct drbd_request *req) * stable storage, and this is a WRITE, we may not even submit * this bio. */ if (get_ldev(device)) { - req->pre_submit_jif = jiffies; if (drbd_insert_fault(device, rw == WRITE ? DRBD_FAULT_DT_WR : rw == READ ? DRBD_FAULT_DT_RD @@ -1293,6 +1310,7 @@ static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request &device->pending_master_completion[rw == WRITE]); if (req->private_bio) { /* needs to be marked within the same spinlock */ + req->pre_submit_jif = jiffies; list_add_tail(&req->req_pending_local, &device->pending_completion[rw == WRITE]); _req_mod(req, TO_BE_SUBMITTED); @@ -1513,6 +1531,78 @@ blk_qc_t drbd_make_request(struct request_queue *q, struct bio *bio) return BLK_QC_T_NONE; } +static bool net_timeout_reached(struct drbd_request *net_req, + struct drbd_connection *connection, + unsigned long now, unsigned long ent, + unsigned int ko_count, unsigned int timeout) +{ + struct drbd_device *device = net_req->device; + + if (!time_after(now, net_req->pre_send_jif + ent)) + return false; + + if (time_in_range(now, connection->last_reconnect_jif, connection->last_reconnect_jif + ent)) + return false; + + if (net_req->rq_state & RQ_NET_PENDING) { + drbd_warn(device, "Remote failed to finish a request within %ums > ko-count (%u) * timeout (%u * 0.1s)\n", + jiffies_to_msecs(now - net_req->pre_send_jif), ko_count, timeout); + return true; + } + + /* We received an ACK already (or are using protocol A), + * but are waiting for the epoch closing barrier ack. + * Check if we sent the barrier already. We should not blame the peer + * for being unresponsive, if we did not even ask it yet. */ + if (net_req->epoch == connection->send.current_epoch_nr) { + drbd_warn(device, + "We did not send a P_BARRIER for %ums > ko-count (%u) * timeout (%u * 0.1s); drbd kernel thread blocked?\n", + jiffies_to_msecs(now - net_req->pre_send_jif), ko_count, timeout); + return false; + } + + /* Worst case: we may have been blocked for whatever reason, then + * suddenly are able to send a lot of requests (and epoch separating + * barriers) in quick succession. + * The timestamp of the net_req may be much too old and not correspond + * to the sending time of the relevant unack'ed barrier packet, so + * would trigger a spurious timeout. The latest barrier packet may + * have a too recent timestamp to trigger the timeout, potentially miss + * a timeout. Right now we don't have a place to conveniently store + * these timestamps. + * But in this particular situation, the application requests are still + * completed to upper layers, DRBD should still "feel" responsive. + * No need yet to kill this connection, it may still recover. + * If not, eventually we will have queued enough into the network for + * us to block. From that point of view, the timestamp of the last sent + * barrier packet is relevant enough. + */ + if (time_after(now, connection->send.last_sent_barrier_jif + ent)) { + drbd_warn(device, "Remote failed to answer a P_BARRIER (sent at %lu jif; now=%lu jif) within %ums > ko-count (%u) * timeout (%u * 0.1s)\n", + connection->send.last_sent_barrier_jif, now, + jiffies_to_msecs(now - connection->send.last_sent_barrier_jif), ko_count, timeout); + return true; + } + return false; +} + +/* A request is considered timed out, if + * - we have some effective timeout from the configuration, + * with some state restrictions applied, + * - the oldest request is waiting for a response from the network + * resp. the local disk, + * - the oldest request is in fact older than the effective timeout, + * - the connection was established (resp. disk was attached) + * for longer than the timeout already. + * Note that for 32bit jiffies and very stable connections/disks, + * we may have a wrap around, which is catched by + * !time_in_range(now, last_..._jif, last_..._jif + timeout). + * + * Side effect: once per 32bit wrap-around interval, which means every + * ~198 days with 250 HZ, we have a window where the timeout would need + * to expire twice (worst case) to become effective. Good enough. + */ + void request_timer_fn(unsigned long data) { struct drbd_device *device = (struct drbd_device *) data; @@ -1522,11 +1612,14 @@ void request_timer_fn(unsigned long data) unsigned long oldest_submit_jif; unsigned long ent = 0, dt = 0, et, nt; /* effective timeout = ko_count * timeout */ unsigned long now; + unsigned int ko_count = 0, timeout = 0; rcu_read_lock(); nc = rcu_dereference(connection->net_conf); - if (nc && device->state.conn >= C_WF_REPORT_PARAMS) - ent = nc->timeout * HZ/10 * nc->ko_count; + if (nc && device->state.conn >= C_WF_REPORT_PARAMS) { + ko_count = nc->ko_count; + timeout = nc->timeout; + } if (get_ldev(device)) { /* implicit state.disk >= D_INCONSISTENT */ dt = rcu_dereference(device->ldev->disk_conf)->disk_timeout * HZ / 10; @@ -1534,6 +1627,8 @@ void request_timer_fn(unsigned long data) } rcu_read_unlock(); + + ent = timeout * HZ/10 * ko_count; et = min_not_zero(dt, ent); if (!et) @@ -1545,11 +1640,22 @@ void request_timer_fn(unsigned long data) spin_lock_irq(&device->resource->req_lock); req_read = list_first_entry_or_null(&device->pending_completion[0], struct drbd_request, req_pending_local); req_write = list_first_entry_or_null(&device->pending_completion[1], struct drbd_request, req_pending_local); - req_peer = connection->req_not_net_done; + /* maybe the oldest request waiting for the peer is in fact still - * blocking in tcp sendmsg */ - if (!req_peer && connection->req_next && connection->req_next->pre_send_jif) - req_peer = connection->req_next; + * blocking in tcp sendmsg. That's ok, though, that's handled via the + * socket send timeout, requesting a ping, and bumping ko-count in + * we_should_drop_the_connection(). + */ + + /* check the oldest request we did successfully sent, + * but which is still waiting for an ACK. */ + req_peer = connection->req_ack_pending; + + /* if we don't have such request (e.g. protocoll A) + * check the oldest requests which is still waiting on its epoch + * closing barrier ack. */ + if (!req_peer) + req_peer = connection->req_not_net_done; /* evaluate the oldest peer request only in one timer! */ if (req_peer && req_peer->device != device) @@ -1566,28 +1672,9 @@ void request_timer_fn(unsigned long data) : req_write ? req_write->pre_submit_jif : req_read ? req_read->pre_submit_jif : now; - /* The request is considered timed out, if - * - we have some effective timeout from the configuration, - * with above state restrictions applied, - * - the oldest request is waiting for a response from the network - * resp. the local disk, - * - the oldest request is in fact older than the effective timeout, - * - the connection was established (resp. disk was attached) - * for longer than the timeout already. - * Note that for 32bit jiffies and very stable connections/disks, - * we may have a wrap around, which is catched by - * !time_in_range(now, last_..._jif, last_..._jif + timeout). - * - * Side effect: once per 32bit wrap-around interval, which means every - * ~198 days with 250 HZ, we have a window where the timeout would need - * to expire twice (worst case) to become effective. Good enough. - */ - if (ent && req_peer && - time_after(now, req_peer->pre_send_jif + ent) && - !time_in_range(now, connection->last_reconnect_jif, connection->last_reconnect_jif + ent)) { - drbd_warn(device, "Remote failed to finish a request within ko-count * timeout\n"); + if (ent && req_peer && net_timeout_reached(req_peer, connection, now, ent, ko_count, timeout)) _conn_request_state(connection, NS(conn, C_TIMEOUT), CS_VERBOSE | CS_HARD); - } + if (dt && oldest_submit_jif != now && time_after(now, oldest_submit_jif + dt) && !time_in_range(now, device->last_reattach_jif, device->last_reattach_jif + dt)) { |