diff options
| -rw-r--r-- | drivers/block/drbd/drbd_int.h | 5 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_main.c | 13 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_receiver.c | 47 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 55 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_req.h | 6 | ||||
| -rw-r--r-- | drivers/block/drbd/drbd_worker.c | 22 |
6 files changed, 139 insertions, 9 deletions
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 819f9d0bc875..74a7d0b70e2c 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -745,6 +745,8 @@ struct drbd_connection { unsigned current_tle_writes; /* writes seen within this tl epoch */ unsigned long last_reconnect_jif; + /* empty member on older kernels without blk_start_plug() */ + struct blk_plug receiver_plug; struct drbd_thread receiver; struct drbd_thread worker; struct drbd_thread ack_receiver; @@ -1131,7 +1133,8 @@ extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_sta extern int drbd_send_rs_deallocated(struct drbd_peer_device *, struct drbd_peer_request *); extern void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev); extern void drbd_device_cleanup(struct drbd_device *device); -void drbd_print_uuids(struct drbd_device *device, const char *text); +extern void drbd_print_uuids(struct drbd_device *device, const char *text); +extern void drbd_queue_unplug(struct drbd_device *device); extern void conn_md_sync(struct drbd_connection *connection); extern void drbd_md_write(struct drbd_device *device, void *buffer); diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index e2ed28d45ce1..a3b2ee74bba9 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -1952,6 +1952,19 @@ static void drbd_release(struct gendisk *gd, fmode_t mode) mutex_unlock(&drbd_main_mutex); } +/* need to hold resource->req_lock */ +void drbd_queue_unplug(struct drbd_device *device) +{ + if (device->state.pdsk >= D_INCONSISTENT && device->state.conn >= C_CONNECTED) { + D_ASSERT(device, device->state.role == R_PRIMARY); + if (test_and_clear_bit(UNPLUG_REMOTE, &device->flags)) { + drbd_queue_work_if_unqueued( + &first_peer_device(device)->connection->sender_work, + &device->unplug_work); + } + } +} + static void drbd_set_defaults(struct drbd_device *device) { /* Beware! The actual layout differs diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index ece6e5d7dc3f..1b3f439a3b23 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1194,6 +1194,14 @@ static int decode_header(struct drbd_connection *connection, void *header, struc return 0; } +static void drbd_unplug_all_devices(struct drbd_connection *connection) +{ + if (current->plug == &connection->receiver_plug) { + blk_finish_plug(&connection->receiver_plug); + blk_start_plug(&connection->receiver_plug); + } /* else: maybe just schedule() ?? */ +} + static int drbd_recv_header(struct drbd_connection *connection, struct packet_info *pi) { void *buffer = connection->data.rbuf; @@ -1209,6 +1217,36 @@ static int drbd_recv_header(struct drbd_connection *connection, struct packet_in return err; } +static int drbd_recv_header_maybe_unplug(struct drbd_connection *connection, struct packet_info *pi) +{ + void *buffer = connection->data.rbuf; + unsigned int size = drbd_header_size(connection); + int err; + + err = drbd_recv_short(connection->data.socket, buffer, size, MSG_NOSIGNAL|MSG_DONTWAIT); + if (err != size) { + /* If we have nothing in the receive buffer now, to reduce + * application latency, try to drain the backend queues as + * quickly as possible, and let remote TCP know what we have + * received so far. */ + if (err == -EAGAIN) { + drbd_tcp_quickack(connection->data.socket); + drbd_unplug_all_devices(connection); + } + if (err > 0) { + buffer += err; + size -= err; + } + err = drbd_recv_all_warn(connection, buffer, size); + if (err) + return err; + } + + err = decode_header(connection, connection->data.rbuf, pi); + connection->last_received = jiffies; + + return err; +} /* This is blkdev_issue_flush, but asynchronous. * We want to submit to all component volumes in parallel, * then wait for all completions. @@ -4882,8 +4920,8 @@ static void drbdd(struct drbd_connection *connection) struct data_cmd const *cmd; drbd_thread_current_set_cpu(&connection->receiver); - update_receiver_timing_details(connection, drbd_recv_header); - if (drbd_recv_header(connection, &pi)) + update_receiver_timing_details(connection, drbd_recv_header_maybe_unplug); + if (drbd_recv_header_maybe_unplug(connection, &pi)) goto err_out; cmd = &drbd_cmd_handler[pi.cmd]; @@ -5375,8 +5413,11 @@ int drbd_receiver(struct drbd_thread *thi) } } while (h == 0); - if (h > 0) + if (h > 0) { + blk_start_plug(&connection->receiver_plug); drbdd(connection); + blk_finish_plug(&connection->receiver_plug); + } conn_disconnect(connection); diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 447c975f5481..5cf43f13e7eb 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -1279,6 +1279,56 @@ static bool may_do_writes(struct drbd_device *device) return s.disk == D_UP_TO_DATE || s.pdsk == D_UP_TO_DATE; } +struct drbd_plug_cb { + struct blk_plug_cb cb; + struct drbd_request *most_recent_req; + /* do we need more? */ +}; + +static void drbd_unplug(struct blk_plug_cb *cb, bool from_schedule) +{ + struct drbd_plug_cb *plug = container_of(cb, struct drbd_plug_cb, cb); + struct drbd_resource *resource = plug->cb.data; + struct drbd_request *req = plug->most_recent_req; + + if (!req) + return; + + spin_lock_irq(&resource->req_lock); + /* In case the sender did not process it yet, raise the flag to + * have it followed with P_UNPLUG_REMOTE just after. */ + req->rq_state |= RQ_UNPLUG; + /* but also queue a generic unplug */ + drbd_queue_unplug(req->device); + spin_unlock_irq(&resource->req_lock); + kref_put(&req->kref, drbd_req_destroy); +} + +static struct drbd_plug_cb* drbd_check_plugged(struct drbd_resource *resource) +{ + /* A lot of text to say + * return (struct drbd_plug_cb*)blk_check_plugged(); */ + struct drbd_plug_cb *plug; + struct blk_plug_cb *cb = blk_check_plugged(drbd_unplug, resource, sizeof(*plug)); + + if (cb) + plug = container_of(cb, struct drbd_plug_cb, cb); + else + plug = NULL; + return plug; +} + +static void drbd_update_plug(struct drbd_plug_cb *plug, struct drbd_request *req) +{ + struct drbd_request *tmp = plug->most_recent_req; + /* Will be sent to some peer. + * Remember to tag it with UNPLUG_REMOTE on unplug */ + kref_get(&req->kref); + plug->most_recent_req = req; + if (tmp) + kref_put(&tmp->kref, drbd_req_destroy); +} + static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request *req) { struct drbd_resource *resource = device->resource; @@ -1287,6 +1337,8 @@ static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request bool no_remote = false; bool submit_private_bio = false; + struct drbd_plug_cb *plug = drbd_check_plugged(resource); + spin_lock_irq(&resource->req_lock); if (rw == WRITE) { /* This may temporarily give up the req_lock, @@ -1351,6 +1403,9 @@ static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request no_remote = true; } + if (plug != NULL && no_remote == false) + drbd_update_plug(plug, req); + /* If it took the fast path in drbd_request_prepare, add it here. * The slow path has added it already. */ if (list_empty(&req->req_pending_master_completion)) diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h index 9e1866ab238f..a2254f825601 100644 --- a/drivers/block/drbd/drbd_req.h +++ b/drivers/block/drbd/drbd_req.h @@ -212,6 +212,11 @@ enum drbd_req_state_bits { /* Should call drbd_al_complete_io() for this request... */ __RQ_IN_ACT_LOG, + /* This was the most recent request during some blk_finish_plug() + * or its implicit from-schedule equivalent. + * We may use it as hint to send a P_UNPLUG_REMOTE */ + __RQ_UNPLUG, + /* The peer has sent a retry ACK */ __RQ_POSTPONED, @@ -249,6 +254,7 @@ enum drbd_req_state_bits { #define RQ_WSAME (1UL << __RQ_WSAME) #define RQ_UNMAP (1UL << __RQ_UNMAP) #define RQ_IN_ACT_LOG (1UL << __RQ_IN_ACT_LOG) +#define RQ_UNPLUG (1UL << __RQ_UNPLUG) #define RQ_POSTPONED (1UL << __RQ_POSTPONED) #define RQ_COMPLETION_SUSP (1UL << __RQ_COMPLETION_SUSP) #define RQ_EXP_RECEIVE_ACK (1UL << __RQ_EXP_RECEIVE_ACK) diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index c268d886c4f0..2745db2255ed 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -1382,18 +1382,22 @@ static int drbd_send_barrier(struct drbd_connection *connection) return conn_send_command(connection, sock, P_BARRIER, sizeof(*p), NULL, 0); } +static int pd_send_unplug_remote(struct drbd_peer_device *pd) +{ + struct drbd_socket *sock = &pd->connection->data; + if (!drbd_prepare_command(pd, sock)) + return -EIO; + return drbd_send_command(pd, sock, P_UNPLUG_REMOTE, 0, NULL, 0); +} + int w_send_write_hint(struct drbd_work *w, int cancel) { struct drbd_device *device = container_of(w, struct drbd_device, unplug_work); - struct drbd_socket *sock; if (cancel) return 0; - sock = &first_peer_device(device)->connection->data; - if (!drbd_prepare_command(first_peer_device(device), sock)) - return -EIO; - return drbd_send_command(first_peer_device(device), sock, P_UNPLUG_REMOTE, 0, NULL, 0); + return pd_send_unplug_remote(first_peer_device(device)); } static void re_init_if_first_write(struct drbd_connection *connection, unsigned int epoch) @@ -1455,6 +1459,7 @@ int w_send_dblock(struct drbd_work *w, int cancel) struct drbd_device *device = req->device; struct drbd_peer_device *const peer_device = first_peer_device(device); struct drbd_connection *connection = peer_device->connection; + bool do_send_unplug = req->rq_state & RQ_UNPLUG; int err; if (unlikely(cancel)) { @@ -1470,6 +1475,9 @@ int w_send_dblock(struct drbd_work *w, int cancel) err = drbd_send_dblock(peer_device, req); req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK); + if (do_send_unplug && !err) + pd_send_unplug_remote(peer_device); + return err; } @@ -1484,6 +1492,7 @@ int w_send_read_req(struct drbd_work *w, int cancel) struct drbd_device *device = req->device; struct drbd_peer_device *const peer_device = first_peer_device(device); struct drbd_connection *connection = peer_device->connection; + bool do_send_unplug = req->rq_state & RQ_UNPLUG; int err; if (unlikely(cancel)) { @@ -1501,6 +1510,9 @@ int w_send_read_req(struct drbd_work *w, int cancel) req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK); + if (do_send_unplug && !err) + pd_send_unplug_remote(peer_device); + return err; } |