diff options
Diffstat (limited to 'drivers/block/drbd/drbd_req.c')
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 1332 |
1 files changed, 862 insertions, 470 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index c24379ffd4e3..d15826f6ee81 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* drbd_req.c @@ -7,19 +8,6 @@ Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>. Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>. - drbd is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. - - drbd is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with drbd; see the file COPYING. If not, write to - the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ @@ -31,59 +19,34 @@ #include "drbd_req.h" -static bool drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int size); - -/* Update disk stats at start of I/O request */ -static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req) -{ - const int rw = bio_data_dir(req->master_bio); - int cpu; - cpu = part_stat_lock(); - part_round_stats(cpu, &mdev->vdisk->part0); - part_stat_inc(cpu, &mdev->vdisk->part0, ios[rw]); - part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], req->i.size >> 9); - (void) cpu; /* The macro invocations above want the cpu argument, I do not like - the compiler warning about cpu only assigned but never used... */ - part_inc_in_flight(&mdev->vdisk->part0, rw); - part_stat_unlock(); -} - -/* Update disk stats when completing request upwards */ -static void _drbd_end_io_acct(struct drbd_conf *mdev, struct drbd_request *req) -{ - int rw = bio_data_dir(req->master_bio); - unsigned long duration = jiffies - req->start_time; - int cpu; - cpu = part_stat_lock(); - part_stat_add(cpu, &mdev->vdisk->part0, ticks[rw], duration); - part_round_stats(cpu, &mdev->vdisk->part0); - part_dec_in_flight(&mdev->vdisk->part0, rw); - part_stat_unlock(); -} +static bool drbd_may_do_local_read(struct drbd_device *device, sector_t sector, int size); -static struct drbd_request *drbd_req_new(struct drbd_conf *mdev, - struct bio *bio_src) +static struct drbd_request *drbd_req_new(struct drbd_device *device, struct bio *bio_src) { struct drbd_request *req; - req = mempool_alloc(drbd_request_mempool, GFP_NOIO); + req = mempool_alloc(&drbd_request_mempool, GFP_NOIO); if (!req) return NULL; + memset(req, 0, sizeof(*req)); - drbd_req_make_private_bio(req, bio_src); - req->rq_state = bio_data_dir(bio_src) == WRITE ? RQ_WRITE : 0; - req->w.mdev = mdev; - req->master_bio = bio_src; - req->epoch = 0; + req->rq_state = (bio_data_dir(bio_src) == WRITE ? RQ_WRITE : 0) + | (bio_op(bio_src) == REQ_OP_WRITE_ZEROES ? RQ_ZEROES : 0) + | (bio_op(bio_src) == REQ_OP_DISCARD ? RQ_UNMAP : 0); + req->device = device; + req->master_bio = bio_src; + req->epoch = 0; drbd_clear_interval(&req->i); - req->i.sector = bio_src->bi_sector; - req->i.size = bio_src->bi_size; + req->i.sector = bio_src->bi_iter.bi_sector; + req->i.size = bio_src->bi_iter.bi_size; req->i.local = true; req->i.waiting = false; INIT_LIST_HEAD(&req->tl_requests); INIT_LIST_HEAD(&req->w.list); + INIT_LIST_HEAD(&req->req_pending_master_completion); + INIT_LIST_HEAD(&req->req_pending_local); /* one reference to be put by __drbd_make_request */ atomic_set(&req->completion_ref, 1); @@ -92,29 +55,58 @@ static struct drbd_request *drbd_req_new(struct drbd_conf *mdev, 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); - struct drbd_conf *mdev = req->w.mdev; + struct drbd_device *device = req->device; const unsigned s = req->rq_state; if ((req->master_bio && !(s & RQ_POSTPONED)) || atomic_read(&req->completion_ref) || (s & RQ_LOCAL_PENDING) || ((s & RQ_NET_MASK) && !(s & RQ_NET_DONE))) { - dev_err(DEV, "drbd_req_destroy: Logic BUG rq_state = 0x%x, completion_ref = %d\n", + drbd_err(device, "drbd_req_destroy: Logic BUG rq_state = 0x%x, completion_ref = %d\n", s, atomic_read(&req->completion_ref)); return; } - /* remove it from the transfer log. - * well, only if it had been there in the first - * place... if it had not (local only or conflicting - * and never sent), it should still be "empty" as - * initialized in drbd_req_new(), so we can list_del() it - * here unconditionally */ + /* If called from mod_rq_state (expected normal case) or + * drbd_send_and_submit (the less likely normal path), this holds the + * req_lock, and req->tl_requests will typicaly be on ->transfer_log, + * though it may be still empty (never added to the transfer log). + * + * If called from do_retry(), we do NOT hold the req_lock, but we are + * still allowed to unconditionally list_del(&req->tl_requests), + * because it will be on a local on-stack list only. */ 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. */ @@ -130,12 +122,13 @@ void drbd_req_destroy(struct kref *kref) * before it even was submitted or sent. * In that case we do not want to touch the bitmap at all. */ + struct drbd_peer_device *peer_device = first_peer_device(device); if ((s & (RQ_POSTPONED|RQ_LOCAL_MASK|RQ_NET_MASK)) != RQ_POSTPONED) { if (!(s & RQ_NET_OK) || !(s & RQ_LOCAL_OK)) - drbd_set_out_of_sync(mdev, req->i.sector, req->i.size); + drbd_set_out_of_sync(peer_device, req->i.sector, req->i.size); if ((s & RQ_NET_OK) && (s & RQ_LOCAL_OK) && (s & RQ_NET_SIS)) - drbd_set_in_sync(mdev, req->i.sector, req->i.size); + drbd_set_in_sync(peer_device, req->i.sector, req->i.size); } /* one might be tempted to move the drbd_al_complete_io @@ -149,57 +142,47 @@ void drbd_req_destroy(struct kref *kref) * we would forget to resync the corresponding extent. */ if (s & RQ_IN_ACT_LOG) { - if (get_ldev_if_state(mdev, D_FAILED)) { - drbd_al_complete_io(mdev, &req->i); - put_ldev(mdev); - } else if (__ratelimit(&drbd_ratelimit_state)) { - dev_warn(DEV, "Should have called drbd_al_complete_io(, %llu, %u), " + if (get_ldev_if_state(device, D_FAILED)) { + drbd_al_complete_io(device, &req->i); + put_ldev(device); + } else if (drbd_ratelimit()) { + drbd_warn(device, "Should have called drbd_al_complete_io(, %llu, %u), " "but my Disk seems to have failed :(\n", (unsigned long long) req->i.sector, req->i.size); } } } - mempool_free(req, drbd_request_mempool); + mempool_free(req, &drbd_request_mempool); } -static void wake_all_senders(struct drbd_tconn *tconn) { - wake_up(&tconn->sender_work.q_wait); +static void wake_all_senders(struct drbd_connection *connection) +{ + wake_up(&connection->sender_work.q_wait); } /* must hold resource->req_lock */ -void start_new_tl_epoch(struct drbd_tconn *tconn) +void start_new_tl_epoch(struct drbd_connection *connection) { /* no point closing an epoch, if it is empty, anyways. */ - if (tconn->current_tle_writes == 0) + if (connection->current_tle_writes == 0) return; - tconn->current_tle_writes = 0; - atomic_inc(&tconn->current_tle_nr); - wake_all_senders(tconn); + connection->current_tle_writes = 0; + atomic_inc(&connection->current_tle_nr); + wake_all_senders(connection); } -void complete_master_bio(struct drbd_conf *mdev, +void complete_master_bio(struct drbd_device *device, struct bio_and_error *m) { - bio_endio(m->bio, m->error); - dec_ap_bio(mdev); + if (unlikely(m->error)) + m->bio->bi_status = errno_to_blk_status(m->error); + bio_endio(m->bio); + dec_ap_bio(device); } -static void drbd_remove_request_interval(struct rb_root *root, - struct drbd_request *req) -{ - struct drbd_conf *mdev = req->w.mdev; - 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(&mdev->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), @@ -210,8 +193,7 @@ static void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m) { const unsigned s = req->rq_state; - struct drbd_conf *mdev = req->w.mdev; - int rw; + struct drbd_device *device = req->device; int error, ok; /* we must not complete the master bio, while it is @@ -226,17 +208,15 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m) if ((s & RQ_LOCAL_PENDING && !(s & RQ_LOCAL_ABORTED)) || (s & RQ_NET_QUEUED) || (s & RQ_NET_PENDING) || (s & RQ_COMPLETION_SUSP)) { - dev_err(DEV, "drbd_req_complete: Logic BUG rq_state = 0x%x\n", s); + drbd_err(device, "drbd_req_complete: Logic BUG rq_state = 0x%x\n", s); return; } if (!req->master_bio) { - dev_err(DEV, "drbd_req_complete: Logic BUG, master_bio == NULL!\n"); + drbd_err(device, "drbd_req_complete: Logic BUG, master_bio == NULL!\n"); return; } - rw = bio_rw(req->master_bio); - /* * figure out whether to report success or failure. * @@ -253,18 +233,6 @@ 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 = &mdev->write_requests; - else - root = &mdev->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 @@ -272,12 +240,12 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m) * epoch number. If they match, increase the current_tle_nr, * and reset the transfer log epoch write_cnt. */ - if (rw == WRITE && - req->epoch == atomic_read(&mdev->tconn->current_tle_nr)) - start_new_tl_epoch(mdev->tconn); + if (op_is_write(bio_op(req->master_bio)) && + req->epoch == atomic_read(&first_peer_device(device)->connection->current_tle_nr)) + start_new_tl_epoch(first_peer_device(device)->connection); /* Update disk stats */ - _drbd_end_io_acct(mdev, req); + bio_end_io_acct(req->master_bio, req->start_jif); /* If READ failed, * have it be pushed back to the retry work queue, @@ -289,38 +257,154 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m) * because no path was available, in which case * it was not even added to the transfer_log. * - * READA may fail, and will not be retried. + * read-ahead may fail, and will not be retried. * * WRITE should have used all available paths already. */ - if (!ok && rw == READ && !list_empty(&req->tl_requests)) + if (!ok && + bio_op(req->master_bio) == REQ_OP_READ && + !(req->master_bio->bi_opf & REQ_RAHEAD) && + !list_empty(&req->tl_requests)) req->rq_state |= RQ_POSTPONED; if (!(req->rq_state & RQ_POSTPONED)) { 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); + + /* Either we are about to complete to upper layers, + * or we will restart this request. + * In either case, the request object will be destroyed soon, + * so better remove it from all lists. */ + list_del_init(&req->req_pending_master_completion); } -static int drbd_req_put_completion_ref(struct drbd_request *req, struct bio_and_error *m, int put) +/* still holds resource->req_lock */ +static void drbd_req_put_completion_ref(struct drbd_request *req, struct bio_and_error *m, int put) { - struct drbd_conf *mdev = req->w.mdev; - D_ASSERT(m || (req->rq_state & RQ_POSTPONED)); + struct drbd_device *device = req->device; + D_ASSERT(device, m || (req->rq_state & RQ_POSTPONED)); + + if (!put) + return; if (!atomic_sub_and_test(put, &req->completion_ref)) - return 0; + return; drbd_req_complete(req, m); + /* local completion may still come in later, + * we need to keep the req object around. */ + if (req->rq_state & RQ_LOCAL_ABORTED) + return; + if (req->rq_state & RQ_POSTPONED) { /* don't destroy the req object just yet, * but queue it for retry */ drbd_restart_request(req); - return 0; + return; } - return 1; + kref_put(&req->kref, drbd_req_destroy); +} + +static void set_if_null_req_next(struct drbd_peer_device *peer_device, struct drbd_request *req) +{ + struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; + if (!connection) + return; + if (connection->req_next == NULL) + connection->req_next = req; +} + +static void advance_conn_req_next(struct drbd_peer_device *peer_device, struct drbd_request *req) +{ + struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; + struct drbd_request *iter = req; + if (!connection) + return; + if (connection->req_next != req) + return; + + req = NULL; + list_for_each_entry_continue(iter, &connection->transfer_log, tl_requests) { + const unsigned int s = iter->rq_state; + + if (s & RQ_NET_QUEUED) { + req = iter; + break; + } + } + connection->req_next = req; +} + +static void set_if_null_req_ack_pending(struct drbd_peer_device *peer_device, struct drbd_request *req) +{ + struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; + if (!connection) + return; + if (connection->req_ack_pending == NULL) + connection->req_ack_pending = req; +} + +static void advance_conn_req_ack_pending(struct drbd_peer_device *peer_device, struct drbd_request *req) +{ + struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; + struct drbd_request *iter = req; + if (!connection) + return; + if (connection->req_ack_pending != req) + return; + + req = NULL; + list_for_each_entry_continue(iter, &connection->transfer_log, tl_requests) { + const unsigned int s = iter->rq_state; + + if ((s & RQ_NET_SENT) && (s & RQ_NET_PENDING)) { + req = iter; + break; + } + } + connection->req_ack_pending = req; +} + +static void set_if_null_req_not_net_done(struct drbd_peer_device *peer_device, struct drbd_request *req) +{ + struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; + if (!connection) + return; + if (connection->req_not_net_done == NULL) + connection->req_not_net_done = req; +} + +static void advance_conn_req_not_net_done(struct drbd_peer_device *peer_device, struct drbd_request *req) +{ + struct drbd_connection *connection = peer_device ? peer_device->connection : NULL; + struct drbd_request *iter = req; + if (!connection) + return; + if (connection->req_not_net_done != req) + return; + + req = NULL; + list_for_each_entry_continue(iter, &connection->transfer_log, tl_requests) { + const unsigned int s = iter->rq_state; + + if ((s & RQ_NET_SENT) && !(s & RQ_NET_DONE)) { + req = iter; + break; + } + } + connection->req_not_net_done = req; } /* I'd like this to be the only place that manipulates @@ -328,12 +412,12 @@ static int drbd_req_put_completion_ref(struct drbd_request *req, struct bio_and_ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, int clear, int set) { - struct drbd_conf *mdev = req->w.mdev; + struct drbd_device *device = req->device; + struct drbd_peer_device *peer_device = first_peer_device(device); unsigned s = req->rq_state; int c_put = 0; - int k_put = 0; - if (drbd_suspended(mdev) && !((s | clear) & RQ_COMPLETION_SUSP)) + if (drbd_suspended(device) && !((s | clear) & RQ_COMPLETION_SUSP)) set |= RQ_COMPLETION_SUSP; /* apply */ @@ -347,22 +431,33 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, /* intent: get references */ + kref_get(&req->kref); + if (!(s & RQ_LOCAL_PENDING) && (set & RQ_LOCAL_PENDING)) atomic_inc(&req->completion_ref); if (!(s & RQ_NET_PENDING) && (set & RQ_NET_PENDING)) { - inc_ap_pending(mdev); + inc_ap_pending(device); atomic_inc(&req->completion_ref); } - if (!(s & RQ_NET_QUEUED) && (set & RQ_NET_QUEUED)) + if (!(s & RQ_NET_QUEUED) && (set & RQ_NET_QUEUED)) { atomic_inc(&req->completion_ref); + set_if_null_req_next(peer_device, req); + } if (!(s & RQ_EXP_BARR_ACK) && (set & RQ_EXP_BARR_ACK)) kref_get(&req->kref); /* wait for the DONE */ - if (!(s & RQ_NET_SENT) && (set & RQ_NET_SENT)) - atomic_add(req->i.size >> 9, &mdev->ap_in_flight); + if (!(s & RQ_NET_SENT) && (set & RQ_NET_SENT)) { + /* 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 (req->rq_state & RQ_NET_PENDING) + set_if_null_req_ack_pending(peer_device, req); + } if (!(s & RQ_COMPLETION_SUSP) && (set & RQ_COMPLETION_SUSP)) atomic_inc(&req->completion_ref); @@ -373,69 +468,78 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, ++c_put; if (!(s & RQ_LOCAL_ABORTED) && (set & RQ_LOCAL_ABORTED)) { - D_ASSERT(req->rq_state & RQ_LOCAL_PENDING); - /* local completion may still come in later, - * we need to keep the req object around. */ - kref_get(&req->kref); + D_ASSERT(device, req->rq_state & RQ_LOCAL_PENDING); ++c_put; } if ((s & RQ_LOCAL_PENDING) && (clear & RQ_LOCAL_PENDING)) { if (req->rq_state & RQ_LOCAL_ABORTED) - ++k_put; + kref_put(&req->kref, drbd_req_destroy); else ++c_put; + list_del_init(&req->req_pending_local); } if ((s & RQ_NET_PENDING) && (clear & RQ_NET_PENDING)) { - dec_ap_pending(mdev); + dec_ap_pending(device); ++c_put; + req->acked_jif = jiffies; + advance_conn_req_ack_pending(peer_device, req); } - if ((s & RQ_NET_QUEUED) && (clear & RQ_NET_QUEUED)) + if ((s & RQ_NET_QUEUED) && (clear & RQ_NET_QUEUED)) { ++c_put; + advance_conn_req_next(peer_device, req); + } - if ((s & RQ_EXP_BARR_ACK) && !(s & RQ_NET_DONE) && (set & RQ_NET_DONE)) { - if (req->rq_state & RQ_NET_SENT) - atomic_sub(req->i.size >> 9, &mdev->ap_in_flight); - ++k_put; + if (!(s & RQ_NET_DONE) && (set & RQ_NET_DONE)) { + if (s & RQ_NET_SENT) + atomic_sub(req->i.size >> 9, &device->ap_in_flight); + if (s & RQ_EXP_BARR_ACK) + kref_put(&req->kref, drbd_req_destroy); + req->net_done_jif = jiffies; + + /* in ahead/behind mode, or just in case, + * before we finally destroy this request, + * the caching pointers must not reference it anymore */ + advance_conn_req_next(peer_device, req); + advance_conn_req_ack_pending(peer_device, req); + advance_conn_req_not_net_done(peer_device, req); } /* potentially complete and destroy */ - if (k_put || c_put) { - /* Completion does it's own kref_put. If we are going to - * kref_sub below, we need req to be still around then. */ - int at_least = k_put + !!c_put; - int refcount = atomic_read(&req->kref.refcount); - if (refcount < at_least) - dev_err(DEV, - "mod_rq_state: Logic BUG: %x -> %x: refcount = %d, should be >= %d\n", - s, req->rq_state, refcount, at_least); - } - /* If we made progress, retry conflicting peer requests, if any. */ if (req->i.waiting) - wake_up(&mdev->misc_wait); + wake_up(&device->misc_wait); - if (c_put) - k_put += drbd_req_put_completion_ref(req, m, c_put); - if (k_put) - kref_sub(&req->kref, k_put, drbd_req_destroy); + drbd_req_put_completion_ref(req, m, c_put); + kref_put(&req->kref, drbd_req_destroy); } -static void drbd_report_io_error(struct drbd_conf *mdev, struct drbd_request *req) +static void drbd_report_io_error(struct drbd_device *device, struct drbd_request *req) { - char b[BDEVNAME_SIZE]; - - if (!__ratelimit(&drbd_ratelimit_state)) + if (!drbd_ratelimit()) return; - dev_warn(DEV, "local %s IO error sector %llu+%u on %s\n", + drbd_warn(device, "local %s IO error sector %llu+%u on %pg\n", (req->rq_state & RQ_WRITE) ? "WRITE" : "READ", (unsigned long long)req->i.sector, req->i.size >> 9, - bdevname(mdev->ldev->backing_bdev, b)); + device->ldev->backing_bdev); +} + +/* Helper for HANDED_OVER_TO_NETWORK. + * Is this a protocol A write (neither WRITE_ACK nor RECEIVE_ACK expected)? + * Is it also still "PENDING"? + * --> If so, clear PENDING and set NET_OK below. + * If it is a protocol A write, but not RQ_PENDING anymore, neg-ack was faster + * (and we must not set RQ_NET_OK) */ +static inline bool is_pending_write_protocol_A(struct drbd_request *req) +{ + return (req->rq_state & + (RQ_WRITE|RQ_NET_PENDING|RQ_EXP_WRITE_ACK|RQ_EXP_RECEIVE_ACK)) + == (RQ_WRITE|RQ_NET_PENDING); } /* obviously this could be coded as many single functions @@ -449,11 +553,16 @@ static void drbd_report_io_error(struct drbd_conf *mdev, struct drbd_request *re * happen "atomically" within the req_lock, * and it enforces that we have to think in a very structured manner * about the "events" that may happen to a request during its life time ... + * + * + * peer_device == NULL means local disk */ int __req_mod(struct drbd_request *req, enum drbd_req_event what, + struct drbd_peer_device *peer_device, struct bio_and_error *m) { - struct drbd_conf *mdev = req->w.mdev; + struct drbd_device *const device = req->device; + struct drbd_connection *const connection = peer_device ? peer_device->connection : NULL; struct net_conf *nc; int p, rv = 0; @@ -462,7 +571,7 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, switch (what) { default: - dev_err(DEV, "LOGIC BUG in %s:%u\n", __FILE__ , __LINE__); + drbd_err(device, "LOGIC BUG in %s:%u\n", __FILE__ , __LINE__); break; /* does not happen... @@ -474,9 +583,9 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, case TO_BE_SENT: /* via network */ /* reached via __drbd_make_request * and from w_read_retry_remote */ - D_ASSERT(!(req->rq_state & RQ_NET_MASK)); + D_ASSERT(device, !(req->rq_state & RQ_NET_MASK)); rcu_read_lock(); - nc = rcu_dereference(mdev->tconn->net_conf); + nc = rcu_dereference(connection->net_conf); p = nc->wire_protocol; rcu_read_unlock(); req->rq_state |= @@ -487,15 +596,15 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, case TO_BE_SUBMITTED: /* locally */ /* reached via __drbd_make_request */ - D_ASSERT(!(req->rq_state & RQ_LOCAL_MASK)); + D_ASSERT(device, !(req->rq_state & RQ_LOCAL_MASK)); mod_rq_state(req, m, 0, RQ_LOCAL_PENDING); break; case COMPLETED_OK: if (req->rq_state & RQ_WRITE) - mdev->writ_cnt += req->i.size >> 9; + device->writ_cnt += req->i.size >> 9; else - mdev->read_cnt += req->i.size >> 9; + device->read_cnt += req->i.size >> 9; mod_rq_state(req, m, RQ_LOCAL_PENDING, RQ_LOCAL_COMPLETED|RQ_LOCAL_OK); @@ -506,23 +615,30 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, break; case WRITE_COMPLETED_WITH_ERROR: - drbd_report_io_error(mdev, req); - __drbd_chk_io_error(mdev, DRBD_WRITE_ERROR); + drbd_report_io_error(device, req); + __drbd_chk_io_error(device, DRBD_WRITE_ERROR); mod_rq_state(req, m, RQ_LOCAL_PENDING, RQ_LOCAL_COMPLETED); break; case READ_COMPLETED_WITH_ERROR: - drbd_set_out_of_sync(mdev, req->i.sector, req->i.size); - drbd_report_io_error(mdev, req); - __drbd_chk_io_error(mdev, DRBD_READ_ERROR); - /* fall through. */ + drbd_set_out_of_sync(peer_device, req->i.sector, req->i.size); + drbd_report_io_error(device, req); + __drbd_chk_io_error(device, DRBD_READ_ERROR); + fallthrough; case READ_AHEAD_COMPLETED_WITH_ERROR: - /* it is legal to fail READA, no __drbd_chk_io_error in that case. */ + /* it is legal to fail read-ahead, no __drbd_chk_io_error in that case. */ + mod_rq_state(req, m, RQ_LOCAL_PENDING, RQ_LOCAL_COMPLETED); + break; + + case DISCARD_COMPLETED_NOTSUPP: + case DISCARD_COMPLETED_WITH_ERROR: + /* I'd rather not detach from local disk just because it + * failed a REQ_OP_DISCARD. */ mod_rq_state(req, m, RQ_LOCAL_PENDING, RQ_LOCAL_COMPLETED); break; case QUEUE_FOR_NET_READ: - /* READ or READA, and + /* READ, and * no local disk, * or target area marked as invalid, * or just got an io-error. */ @@ -532,16 +648,17 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, /* So we can verify the handle in the answer packet. * Corresponding drbd_remove_request_interval is in * drbd_req_complete() */ - D_ASSERT(drbd_interval_empty(&req->i)); - drbd_insert_interval(&mdev->read_requests, &req->i); + D_ASSERT(device, drbd_interval_empty(&req->i)); + drbd_insert_interval(&device->read_requests, &req->i); - set_bit(UNPLUG_REMOTE, &mdev->flags); + set_bit(UNPLUG_REMOTE, &device->flags); - D_ASSERT(req->rq_state & RQ_NET_PENDING); - D_ASSERT((req->rq_state & RQ_LOCAL_MASK) == 0); + D_ASSERT(device, req->rq_state & RQ_NET_PENDING); + D_ASSERT(device, (req->rq_state & RQ_LOCAL_MASK) == 0); mod_rq_state(req, m, 0, RQ_NET_QUEUED); req->w.cb = w_send_read_req; - drbd_queue_work(&mdev->tconn->sender_work, &req->w); + drbd_queue_work(&connection->sender_work, + &req->w); break; case QUEUE_FOR_NET_WRITE: @@ -550,8 +667,8 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, /* Corresponding drbd_remove_request_interval is in * drbd_req_complete() */ - D_ASSERT(drbd_interval_empty(&req->i)); - drbd_insert_interval(&mdev->write_requests, &req->i); + D_ASSERT(device, drbd_interval_empty(&req->i)); + drbd_insert_interval(&device->write_requests, &req->i); /* NOTE * In case the req ended up on the transfer log before being @@ -570,28 +687,30 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, /* otherwise we may lose an unplug, which may cause some remote * io-scheduler timeout to expire, increasing maximum latency, * hurting performance. */ - set_bit(UNPLUG_REMOTE, &mdev->flags); + set_bit(UNPLUG_REMOTE, &device->flags); /* queue work item to send data */ - D_ASSERT(req->rq_state & RQ_NET_PENDING); + D_ASSERT(device, req->rq_state & RQ_NET_PENDING); mod_rq_state(req, m, 0, RQ_NET_QUEUED|RQ_EXP_BARR_ACK); req->w.cb = w_send_dblock; - drbd_queue_work(&mdev->tconn->sender_work, &req->w); + drbd_queue_work(&connection->sender_work, + &req->w); /* close the epoch, in case it outgrew the limit */ rcu_read_lock(); - nc = rcu_dereference(mdev->tconn->net_conf); + nc = rcu_dereference(connection->net_conf); p = nc->max_epoch_size; rcu_read_unlock(); - if (mdev->tconn->current_tle_writes >= p) - start_new_tl_epoch(mdev->tconn); + if (connection->current_tle_writes >= p) + start_new_tl_epoch(connection); break; case QUEUE_FOR_SEND_OOS: mod_rq_state(req, m, 0, RQ_NET_QUEUED); req->w.cb = w_send_out_of_sync; - drbd_queue_work(&mdev->tconn->sender_work, &req->w); + drbd_queue_work(&connection->sender_work, + &req->w); break; case READ_RETRY_REMOTE_CANCELED: @@ -604,18 +723,16 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, case HANDED_OVER_TO_NETWORK: /* assert something? */ - if (bio_data_dir(req->master_bio) == WRITE && - !(req->rq_state & (RQ_EXP_RECEIVE_ACK | RQ_EXP_WRITE_ACK))) { + if (is_pending_write_protocol_A(req)) /* this is what is dangerous about protocol A: * pretend it was successfully written on the peer. */ - if (req->rq_state & RQ_NET_PENDING) - mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK); - /* else: neg-ack was faster... */ - /* it is still not yet RQ_NET_DONE until the - * corresponding epoch barrier got acked as well, - * so we know what to dirty on connection loss */ - } - mod_rq_state(req, m, RQ_NET_QUEUED, RQ_NET_SENT); + mod_rq_state(req, m, RQ_NET_QUEUED|RQ_NET_PENDING, + RQ_NET_SENT|RQ_NET_OK); + else + mod_rq_state(req, m, RQ_NET_QUEUED, RQ_NET_SENT); + /* It is still not yet RQ_NET_DONE until the + * corresponding epoch barrier got acked as well, + * so we know what to dirty on connection loss. */ break; case OOS_HANDED_TO_NETWORK: @@ -639,41 +756,42 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, * If this request had been marked as RQ_POSTPONED before, * it will actually not be completed, but "restarted", * resubmitted from the retry worker context. */ - D_ASSERT(req->rq_state & RQ_NET_PENDING); - D_ASSERT(req->rq_state & RQ_EXP_WRITE_ACK); + D_ASSERT(device, req->rq_state & RQ_NET_PENDING); + D_ASSERT(device, req->rq_state & RQ_EXP_WRITE_ACK); mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_DONE|RQ_NET_OK); break; case WRITE_ACKED_BY_PEER_AND_SIS: req->rq_state |= RQ_NET_SIS; + fallthrough; case WRITE_ACKED_BY_PEER: - D_ASSERT(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(req->rq_state & RQ_EXP_RECEIVE_ACK); + D_ASSERT(device, req->rq_state & RQ_EXP_RECEIVE_ACK); /* protocol B; pretends to be successfully written on peer. * see also notes above in HANDED_OVER_TO_NETWORK about * protocol != C */ ack_common: - D_ASSERT(req->rq_state & RQ_NET_PENDING); mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK); break; case POSTPONE_WRITE: - D_ASSERT(req->rq_state & RQ_EXP_WRITE_ACK); + D_ASSERT(device, req->rq_state & RQ_EXP_WRITE_ACK); /* If this node has already detected the write conflict, the * worker will be waiting on misc_wait. Wake it up once this * request has completed locally. */ - D_ASSERT(req->rq_state & RQ_NET_PENDING); + D_ASSERT(device, req->rq_state & RQ_NET_PENDING); req->rq_state |= RQ_POSTPONED; if (req->i.waiting) - wake_up(&mdev->misc_wait); + wake_up(&device->misc_wait); /* Do not clear RQ_NET_PENDING. This request will make further * progress via restart_conflicting_writes() or * fail_postponed_requests(). Hopefully. */ @@ -701,9 +819,10 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, if (bio_data_dir(req->master_bio) == WRITE) rv = MR_WRITE; - get_ldev(mdev); /* always succeeds in this call path */ + get_ldev(device); /* always succeeds in this call path */ req->w.cb = w_restart_disk_io; - drbd_queue_work(&mdev->tconn->sender_work, &req->w); + drbd_queue_work(&connection->sender_work, + &req->w); break; case RESEND: @@ -719,17 +838,19 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, Throwing them out of the TL here by pretending we got a BARRIER_ACK. During connection handshake, we ensure that the peer was not rebooted. */ if (!(req->rq_state & RQ_NET_OK)) { - /* FIXME could this possibly be a req->w.cb == w_send_out_of_sync? + /* FIXME could this possibly be a req->dw.cb == w_send_out_of_sync? * in that case we must not set RQ_NET_PENDING. */ mod_rq_state(req, m, RQ_COMPLETION_SUSP, RQ_NET_QUEUED|RQ_NET_PENDING); if (req->w.cb) { - drbd_queue_work(&mdev->tconn->sender_work, &req->w); + /* w.cb expected to be w_send_dblock, or w_send_read_req */ + drbd_queue_work(&connection->sender_work, + &req->w); rv = req->rq_state & RQ_WRITE ? MR_WRITE : MR_READ; } /* else: FIXME can this happen? */ break; } - /* else, fall through to BARRIER_ACKED */ + fallthrough; /* to BARRIER_ACKED */ case BARRIER_ACKED: /* barrier ack for READ requests does not make sense */ @@ -740,7 +861,7 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, /* barrier came in before all requests were acked. * this is bad, because if the connection is lost now, * we won't be able to clean them up... */ - dev_err(DEV, "FIXME (BARRIER_ACKED but pending)\n"); + drbd_err(device, "FIXME (BARRIER_ACKED but pending)\n"); } /* Allowed to complete requests, even while suspended. * As this is called for all requests within a matching epoch, @@ -751,15 +872,15 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, break; case DATA_RECEIVED: - D_ASSERT(req->rq_state & RQ_NET_PENDING); + D_ASSERT(device, req->rq_state & RQ_NET_PENDING); mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK|RQ_NET_DONE); break; case QUEUE_AS_DRBD_BARRIER: - start_new_tl_epoch(mdev->tconn); + start_new_tl_epoch(connection); mod_rq_state(req, m, 0, RQ_NET_OK|RQ_NET_DONE); break; - }; + } return rv; } @@ -771,39 +892,37 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what, * since size may be bigger than BM_BLOCK_SIZE, * we may need to check several bits. */ -static bool drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int size) +static bool drbd_may_do_local_read(struct drbd_device *device, sector_t sector, int size) { unsigned long sbnr, ebnr; sector_t esector, nr_sectors; - if (mdev->state.disk == D_UP_TO_DATE) + if (device->state.disk == D_UP_TO_DATE) return true; - if (mdev->state.disk != D_INCONSISTENT) + if (device->state.disk != D_INCONSISTENT) return false; esector = sector + (size >> 9) - 1; - nr_sectors = drbd_get_capacity(mdev->this_bdev); - D_ASSERT(sector < nr_sectors); - D_ASSERT(esector < nr_sectors); + nr_sectors = get_capacity(device->vdisk); + D_ASSERT(device, sector < nr_sectors); + D_ASSERT(device, esector < nr_sectors); sbnr = BM_SECT_TO_BIT(sector); ebnr = BM_SECT_TO_BIT(esector); - return drbd_bm_count_bits(mdev, sbnr, ebnr) == 0; + return drbd_bm_count_bits(device, sbnr, ebnr) == 0; } -static bool remote_due_to_read_balancing(struct drbd_conf *mdev, sector_t sector, +static bool remote_due_to_read_balancing(struct drbd_device *device, sector_t sector, enum drbd_read_balancing rbm) { - struct backing_dev_info *bdi; int stripe_shift; switch (rbm) { case RB_CONGESTED_REMOTE: - bdi = &mdev->ldev->backing_bdev->bd_disk->queue->backing_dev_info; - return bdi_read_congested(bdi); + return false; case RB_LEAST_PENDING: - return atomic_read(&mdev->local_cnt) > - atomic_read(&mdev->ap_pending_cnt) + atomic_read(&mdev->rs_pending_cnt); + return atomic_read(&device->local_cnt) > + atomic_read(&device->ap_pending_cnt) + atomic_read(&device->rs_pending_cnt); case RB_32K_STRIPING: /* stripe_shift = 15 */ case RB_64K_STRIPING: case RB_128K_STRIPING: @@ -813,7 +932,7 @@ static bool remote_due_to_read_balancing(struct drbd_conf *mdev, sector_t sector stripe_shift = (rbm - RB_32K_STRIPING + 15); return (sector >> (stripe_shift - 9)) & 1; case RB_ROUND_ROBIN: - return test_and_change_bit(READ_BALANCE_RR, &mdev->flags); + return test_and_change_bit(READ_BALANCE_RR, &device->flags); case RB_PREFER_REMOTE: return true; case RB_PREFER_LOCAL: @@ -834,73 +953,80 @@ static bool remote_due_to_read_balancing(struct drbd_conf *mdev, sector_t sector static void complete_conflicting_writes(struct drbd_request *req) { DEFINE_WAIT(wait); - struct drbd_conf *mdev = req->w.mdev; + struct drbd_device *device = req->device; struct drbd_interval *i; sector_t sector = req->i.sector; int size = req->i.size; - i = drbd_find_overlap(&mdev->write_requests, sector, size); - if (!i) - return; - for (;;) { - prepare_to_wait(&mdev->misc_wait, &wait, TASK_UNINTERRUPTIBLE); - i = drbd_find_overlap(&mdev->write_requests, sector, size); - if (!i) + drbd_for_each_overlap(i, &device->write_requests, sector, size) { + /* Ignore, if already completed to upper layers. */ + if (i->completed) + continue; + /* Handle the first found overlap. After the schedule + * we have to restart the tree walk. */ + break; + } + if (!i) /* if any */ break; + /* Indicate to wake up device->misc_wait on progress. */ + prepare_to_wait(&device->misc_wait, &wait, TASK_UNINTERRUPTIBLE); i->waiting = true; - spin_unlock_irq(&mdev->tconn->req_lock); + spin_unlock_irq(&device->resource->req_lock); schedule(); - spin_lock_irq(&mdev->tconn->req_lock); + spin_lock_irq(&device->resource->req_lock); } - finish_wait(&mdev->misc_wait, &wait); + finish_wait(&device->misc_wait, &wait); } -/* called within req_lock and rcu_read_lock() */ -static void maybe_pull_ahead(struct drbd_conf *mdev) +/* called within req_lock */ +static void maybe_pull_ahead(struct drbd_device *device) { - struct drbd_tconn *tconn = mdev->tconn; + struct drbd_connection *connection = first_peer_device(device)->connection; struct net_conf *nc; bool congested = false; enum drbd_on_congestion on_congestion; rcu_read_lock(); - nc = rcu_dereference(tconn->net_conf); + nc = rcu_dereference(connection->net_conf); on_congestion = nc ? nc->on_congestion : OC_BLOCK; rcu_read_unlock(); if (on_congestion == OC_BLOCK || - tconn->agreed_pro_version < 96) + connection->agreed_pro_version < 96) return; + if (on_congestion == OC_PULL_AHEAD && device->state.conn == C_AHEAD) + return; /* nothing to do ... */ + /* If I don't even have good local storage, we can not reasonably try * to pull ahead of the peer. We also need the local reference to make - * sure mdev->act_log is there. + * sure device->act_log is there. */ - if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) + if (!get_ldev_if_state(device, D_UP_TO_DATE)) return; if (nc->cong_fill && - atomic_read(&mdev->ap_in_flight) >= nc->cong_fill) { - dev_info(DEV, "Congestion-fill threshold reached\n"); + atomic_read(&device->ap_in_flight) >= nc->cong_fill) { + drbd_info(device, "Congestion-fill threshold reached\n"); congested = true; } - if (mdev->act_log->used >= nc->cong_extents) { - dev_info(DEV, "Congestion-extents threshold reached\n"); + if (device->act_log->used >= nc->cong_extents) { + drbd_info(device, "Congestion-extents threshold reached\n"); congested = true; } if (congested) { /* start a new epoch for non-mirrored writes */ - start_new_tl_epoch(mdev->tconn); + start_new_tl_epoch(first_peer_device(device)->connection); if (on_congestion == OC_PULL_AHEAD) - _drbd_set_state(_NS(mdev, conn, C_AHEAD), 0, NULL); + _drbd_set_state(_NS(device, conn, C_AHEAD), 0, NULL); else /*nc->on_congestion == OC_DISCONNECT */ - _drbd_set_state(_NS(mdev, conn, C_DISCONNECTING), 0, NULL); + _drbd_set_state(_NS(device, conn, C_DISCONNECTING), 0, NULL); } - put_ldev(mdev); + put_ldev(device); } /* If this returns false, and req->private_bio is still set, @@ -914,19 +1040,19 @@ static void maybe_pull_ahead(struct drbd_conf *mdev) */ static bool do_remote_read(struct drbd_request *req) { - struct drbd_conf *mdev = req->w.mdev; + struct drbd_device *device = req->device; enum drbd_read_balancing rbm; if (req->private_bio) { - if (!drbd_may_do_local_read(mdev, + if (!drbd_may_do_local_read(device, req->i.sector, req->i.size)) { bio_put(req->private_bio); req->private_bio = NULL; - put_ldev(mdev); + put_ldev(device); } } - if (mdev->state.pdsk != D_UP_TO_DATE) + if (device->state.pdsk != D_UP_TO_DATE) return false; if (req->private_bio == NULL) @@ -936,17 +1062,17 @@ static bool do_remote_read(struct drbd_request *req) * protocol, pending requests etc. */ rcu_read_lock(); - rbm = rcu_dereference(mdev->ldev->disk_conf)->read_balancing; + rbm = rcu_dereference(device->ldev->disk_conf)->read_balancing; rcu_read_unlock(); if (rbm == RB_PREFER_LOCAL && req->private_bio) return false; /* submit locally */ - if (remote_due_to_read_balancing(mdev, req->i.sector, rbm)) { + if (remote_due_to_read_balancing(device, req->i.sector, rbm)) { if (req->private_bio) { bio_put(req->private_bio); req->private_bio = NULL; - put_ldev(mdev); + put_ldev(device); } return true; } @@ -954,16 +1080,35 @@ 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. */ static int drbd_process_write_request(struct drbd_request *req) { - struct drbd_conf *mdev = req->w.mdev; + struct drbd_device *device = req->device; + struct drbd_peer_device *peer_device = first_peer_device(device); int remote, send_oos; - remote = drbd_should_do_remote(mdev->state); - send_oos = drbd_should_send_out_of_sync(mdev->state); + remote = drbd_should_do_remote(device->state); + send_oos = drbd_should_send_out_of_sync(device->state); /* Need to replicate writes. Unless it is an empty flush, * which is better mapped to a DRBD P_BARRIER packet, @@ -973,59 +1118,79 @@ static int drbd_process_write_request(struct drbd_request *req) * replicating, in which case there is no point. */ if (unlikely(req->i.size == 0)) { /* The only size==0 bios we expect are empty flushes. */ - D_ASSERT(req->master_bio->bi_rw & REQ_FLUSH); + D_ASSERT(device, req->master_bio->bi_opf & REQ_PREFLUSH); if (remote) - _req_mod(req, QUEUE_AS_DRBD_BARRIER); + _req_mod(req, QUEUE_AS_DRBD_BARRIER, peer_device); return remote; } if (!remote && !send_oos) return 0; - D_ASSERT(!(remote && send_oos)); + D_ASSERT(device, !(remote && send_oos)); if (remote) { - _req_mod(req, TO_BE_SENT); - _req_mod(req, QUEUE_FOR_NET_WRITE); - } else if (drbd_set_out_of_sync(mdev, req->i.sector, req->i.size)) - _req_mod(req, QUEUE_FOR_SEND_OOS); + _req_mod(req, TO_BE_SENT, peer_device); + _req_mod(req, QUEUE_FOR_NET_WRITE, peer_device); + } else if (drbd_set_out_of_sync(peer_device, req->i.sector, req->i.size)) + _req_mod(req, QUEUE_FOR_SEND_OOS, peer_device); return remote; } +static void drbd_process_discard_or_zeroes_req(struct drbd_request *req, int flags) +{ + int err = drbd_issue_discard_or_zero_out(req->device, + req->i.sector, req->i.size >> 9, flags); + if (err) + req->private_bio->bi_status = BLK_STS_IOERR; + bio_endio(req->private_bio); +} + static void drbd_submit_req_private_bio(struct drbd_request *req) { - struct drbd_conf *mdev = req->w.mdev; + struct drbd_device *device = req->device; struct bio *bio = req->private_bio; - const int rw = bio_rw(bio); + unsigned int type; - bio->bi_bdev = mdev->ldev->backing_bdev; + if (bio_op(bio) != REQ_OP_READ) + type = DRBD_FAULT_DT_WR; + else if (bio->bi_opf & REQ_RAHEAD) + type = DRBD_FAULT_DT_RA; + else + type = DRBD_FAULT_DT_RD; /* State may have changed since we grabbed our reference on the * ->ldev member. Double check, and short-circuit to endio. * In case the last activity log transaction failed to get on * stable storage, and this is a WRITE, we may not even submit * this bio. */ - if (get_ldev(mdev)) { - if (drbd_insert_fault(mdev, - rw == WRITE ? DRBD_FAULT_DT_WR - : rw == READ ? DRBD_FAULT_DT_RD - : DRBD_FAULT_DT_RA)) - bio_endio(bio, -EIO); + if (get_ldev(device)) { + if (drbd_insert_fault(device, type)) + bio_io_error(bio); + else if (bio_op(bio) == REQ_OP_WRITE_ZEROES) + drbd_process_discard_or_zeroes_req(req, EE_ZEROOUT | + ((bio->bi_opf & REQ_NOUNMAP) ? 0 : EE_TRIM)); + else if (bio_op(bio) == REQ_OP_DISCARD) + drbd_process_discard_or_zeroes_req(req, EE_TRIM); else - generic_make_request(bio); - put_ldev(mdev); + submit_bio_noacct(bio); + put_ldev(device); } else - bio_endio(bio, -EIO); + bio_io_error(bio); } -static void drbd_queue_write(struct drbd_conf *mdev, struct drbd_request *req) +static void drbd_queue_write(struct drbd_device *device, struct drbd_request *req) { - spin_lock(&mdev->submit.lock); - list_add_tail(&req->tl_requests, &mdev->submit.writes); - spin_unlock(&mdev->submit.lock); - queue_work(mdev->submit.wq, &mdev->submit.worker); + spin_lock_irq(&device->resource->req_lock); + list_add_tail(&req->tl_requests, &device->submit.writes); + list_add_tail(&req->req_pending_master_completion, + &device->pending_master_completion[1 /* WRITE */]); + spin_unlock_irq(&device->resource->req_lock); + queue_work(device->submit.wq, &device->submit.worker); + /* do_submit() may sleep internally on al_wait, too */ + wake_up(&device->al_wait); } /* returns the new drbd_request pointer, if the caller is expected to @@ -1033,51 +1198,132 @@ static void drbd_queue_write(struct drbd_conf *mdev, struct drbd_request *req) * request on the submitter thread. * Returns ERR_PTR(-ENOMEM) if we cannot allocate a drbd_request. */ -struct drbd_request * -drbd_request_prepare(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time) +static struct drbd_request * +drbd_request_prepare(struct drbd_device *device, struct bio *bio) { const int rw = bio_data_dir(bio); struct drbd_request *req; /* allocate outside of all locks; */ - req = drbd_req_new(mdev, bio); + req = drbd_req_new(device, bio); if (!req) { - dec_ap_bio(mdev); + dec_ap_bio(device); /* only pass the error to the upper layers. * if user cannot handle io errors, that's not our business. */ - dev_err(DEV, "could not kmalloc() req\n"); - bio_endio(bio, -ENOMEM); + drbd_err(device, "could not kmalloc() req\n"); + bio->bi_status = BLK_STS_RESOURCE; + bio_endio(bio); return ERR_PTR(-ENOMEM); } - req->start_time = start_time; - if (!get_ldev(mdev)) { - bio_put(req->private_bio); - req->private_bio = NULL; + /* Update disk stats */ + req->start_jif = bio_start_io_acct(req->master_bio); + + if (get_ldev(device)) { + req->private_bio = bio_alloc_clone(device->ldev->backing_bdev, + bio, GFP_NOIO, + &drbd_io_bio_set); + req->private_bio->bi_private = req; + req->private_bio->bi_end_io = drbd_request_endio; } - /* Update disk stats */ - _drbd_start_io_acct(mdev, req); + /* process discards always from our submitter thread */ + if (bio_op(bio) == REQ_OP_WRITE_ZEROES || + bio_op(bio) == REQ_OP_DISCARD) + goto queue_for_submitter_thread; if (rw == WRITE && req->private_bio && req->i.size - && !test_bit(AL_SUSPENDED, &mdev->flags)) { - if (!drbd_al_begin_io_fastpath(mdev, &req->i)) { - drbd_queue_write(mdev, req); - return NULL; - } + && !test_bit(AL_SUSPENDED, &device->flags)) { + if (!drbd_al_begin_io_fastpath(device, &req->i)) + goto queue_for_submitter_thread; req->rq_state |= RQ_IN_ACT_LOG; + req->in_actlog_jif = jiffies; } - return req; + + queue_for_submitter_thread: + atomic_inc(&device->ap_actlog_cnt); + drbd_queue_write(device, req); + return NULL; +} + +/* Require at least one path to current data. + * We don't want to allow writes on C_STANDALONE D_INCONSISTENT: + * We would not allow to read what was written, + * we would not have bumped the data generation uuids, + * we would cause data divergence for all the wrong reasons. + * + * If we don't see at least one D_UP_TO_DATE, we will fail this request, + * which either returns EIO, or, if OND_SUSPEND_IO is set, suspends IO, + * and queues for retry later. + */ +static bool may_do_writes(struct drbd_device *device) +{ + const union drbd_dev_state s = device->state; + 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; + + kfree(cb); + 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); + kref_put(&req->kref, drbd_req_destroy); + spin_unlock_irq(&resource->req_lock); +} + +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_conf *mdev, struct drbd_request *req) +static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request *req) { - const int rw = bio_rw(req->master_bio); + struct drbd_resource *resource = device->resource; + struct drbd_peer_device *peer_device = first_peer_device(device); + const int rw = bio_data_dir(req->master_bio); struct bio_and_error m = { NULL, }; bool no_remote = false; + bool submit_private_bio = false; - spin_lock_irq(&mdev->tconn->req_lock); + spin_lock_irq(&resource->req_lock); if (rw == WRITE) { /* This may temporarily give up the req_lock, * but will re-aquire it before it returns here. @@ -1087,22 +1333,22 @@ static void drbd_send_and_submit(struct drbd_conf *mdev, struct drbd_request *re /* check for congestion, and potentially stop sending * full data updates, but start sending "dirty bits" only. */ - maybe_pull_ahead(mdev); + maybe_pull_ahead(device); } - if (drbd_suspended(mdev)) { + if (drbd_suspended(device)) { /* push back and retry: */ req->rq_state |= RQ_POSTPONED; if (req->private_bio) { bio_put(req->private_bio); req->private_bio = NULL; - put_ldev(mdev); + put_ldev(device); } goto out; } - /* We fail READ/READA early, if we can not serve it. + /* We fail READ early, if we can not serve it. * We must do this before req is registered on any lists. * Otherwise, drbd_req_complete() will queue failed READ for retry. */ if (rw != WRITE) { @@ -1111,288 +1357,434 @@ static void drbd_send_and_submit(struct drbd_conf *mdev, struct drbd_request *re } /* which transfer log epoch does this belong to? */ - req->epoch = atomic_read(&mdev->tconn->current_tle_nr); + req->epoch = atomic_read(&first_peer_device(device)->connection->current_tle_nr); /* no point in adding empty flushes to the transfer log, * they are mapped to drbd barriers already. */ if (likely(req->i.size!=0)) { if (rw == WRITE) - mdev->tconn->current_tle_writes++; + first_peer_device(device)->connection->current_tle_writes++; - list_add_tail(&req->tl_requests, &mdev->tconn->transfer_log); + list_add_tail(&req->tl_requests, &first_peer_device(device)->connection->transfer_log); } if (rw == WRITE) { + if (req->private_bio && !may_do_writes(device)) { + bio_put(req->private_bio); + req->private_bio = NULL; + put_ldev(device); + goto nodata; + } if (!drbd_process_write_request(req)) no_remote = true; } else { /* We either have a private_bio, or we can read from remote. * Otherwise we had done the goto nodata above. */ if (req->private_bio == NULL) { - _req_mod(req, TO_BE_SENT); - _req_mod(req, QUEUE_FOR_NET_READ); + _req_mod(req, TO_BE_SENT, peer_device); + _req_mod(req, QUEUE_FOR_NET_READ, peer_device); } else no_remote = true; } + if (no_remote == false) { + struct drbd_plug_cb *plug = drbd_check_plugged(resource); + if (plug) + 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)) + list_add_tail(&req->req_pending_master_completion, + &device->pending_master_completion[rw == WRITE]); if (req->private_bio) { /* needs to be marked within the same spinlock */ - _req_mod(req, TO_BE_SUBMITTED); + req->pre_submit_jif = jiffies; + list_add_tail(&req->req_pending_local, + &device->pending_completion[rw == WRITE]); + _req_mod(req, TO_BE_SUBMITTED, NULL); /* but we need to give up the spinlock to submit */ - spin_unlock_irq(&mdev->tconn->req_lock); - drbd_submit_req_private_bio(req); - spin_lock_irq(&mdev->tconn->req_lock); + submit_private_bio = true; } else if (no_remote) { nodata: - if (__ratelimit(&drbd_ratelimit_state)) - dev_err(DEV, "IO ERROR: neither local nor remote data, sector %llu+%u\n", + if (drbd_ratelimit()) + drbd_err(device, "IO ERROR: neither local nor remote data, sector %llu+%u\n", (unsigned long long)req->i.sector, req->i.size >> 9); /* A write may have been queued for send_oos, however. * So we can not simply free it, we must go through drbd_req_put_completion_ref() */ } out: - if (drbd_req_put_completion_ref(req, &m, 1)) - kref_put(&req->kref, drbd_req_destroy); - spin_unlock_irq(&mdev->tconn->req_lock); - + drbd_req_put_completion_ref(req, &m, 1); + spin_unlock_irq(&resource->req_lock); + + /* Even though above is a kref_put(), this is safe. + * As long as we still need to submit our private bio, + * we hold a completion ref, and the request cannot disappear. + * If however this request did not even have a private bio to submit + * (e.g. remote read), req may already be invalid now. + * That's why we cannot check on req->private_bio. */ + if (submit_private_bio) + drbd_submit_req_private_bio(req); if (m.bio) - complete_master_bio(mdev, &m); + complete_master_bio(device, &m); } -void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time) +void __drbd_make_request(struct drbd_device *device, struct bio *bio) { - struct drbd_request *req = drbd_request_prepare(mdev, bio, start_time); + struct drbd_request *req = drbd_request_prepare(device, bio); if (IS_ERR_OR_NULL(req)) return; - drbd_send_and_submit(mdev, req); + drbd_send_and_submit(device, req); } -static void submit_fast_path(struct drbd_conf *mdev, struct list_head *incoming) +static void submit_fast_path(struct drbd_device *device, struct list_head *incoming) { + struct blk_plug plug; struct drbd_request *req, *tmp; + + blk_start_plug(&plug); list_for_each_entry_safe(req, tmp, incoming, tl_requests) { const int rw = bio_data_dir(req->master_bio); if (rw == WRITE /* rw != WRITE should not even end up here! */ && req->private_bio && req->i.size - && !test_bit(AL_SUSPENDED, &mdev->flags)) { - if (!drbd_al_begin_io_fastpath(mdev, &req->i)) + && !test_bit(AL_SUSPENDED, &device->flags)) { + if (!drbd_al_begin_io_fastpath(device, &req->i)) continue; req->rq_state |= RQ_IN_ACT_LOG; + req->in_actlog_jif = jiffies; + atomic_dec(&device->ap_actlog_cnt); } list_del_init(&req->tl_requests); - drbd_send_and_submit(mdev, req); + drbd_send_and_submit(device, req); } + blk_finish_plug(&plug); } -static bool prepare_al_transaction_nonblock(struct drbd_conf *mdev, +static bool prepare_al_transaction_nonblock(struct drbd_device *device, struct list_head *incoming, - struct list_head *pending) + struct list_head *pending, + struct list_head *later) { - struct drbd_request *req, *tmp; + struct drbd_request *req; int wake = 0; int err; - spin_lock_irq(&mdev->al_lock); - list_for_each_entry_safe(req, tmp, incoming, tl_requests) { - err = drbd_al_begin_io_nonblock(mdev, &req->i); + spin_lock_irq(&device->al_lock); + while ((req = list_first_entry_or_null(incoming, struct drbd_request, tl_requests))) { + err = drbd_al_begin_io_nonblock(device, &req->i); + if (err == -ENOBUFS) + break; if (err == -EBUSY) wake = 1; if (err) - continue; - req->rq_state |= RQ_IN_ACT_LOG; - list_move_tail(&req->tl_requests, pending); + list_move_tail(&req->tl_requests, later); + else + list_move_tail(&req->tl_requests, pending); } - spin_unlock_irq(&mdev->al_lock); + spin_unlock_irq(&device->al_lock); if (wake) - wake_up(&mdev->al_wait); - + wake_up(&device->al_wait); return !list_empty(pending); } +static void send_and_submit_pending(struct drbd_device *device, struct list_head *pending) +{ + struct blk_plug plug; + struct drbd_request *req; + + blk_start_plug(&plug); + while ((req = list_first_entry_or_null(pending, struct drbd_request, tl_requests))) { + req->rq_state |= RQ_IN_ACT_LOG; + req->in_actlog_jif = jiffies; + atomic_dec(&device->ap_actlog_cnt); + list_del_init(&req->tl_requests); + drbd_send_and_submit(device, req); + } + blk_finish_plug(&plug); +} + void do_submit(struct work_struct *ws) { - struct drbd_conf *mdev = container_of(ws, struct drbd_conf, submit.worker); - LIST_HEAD(incoming); - LIST_HEAD(pending); - struct drbd_request *req, *tmp; + struct drbd_device *device = container_of(ws, struct drbd_device, submit.worker); + LIST_HEAD(incoming); /* from drbd_make_request() */ + LIST_HEAD(pending); /* to be submitted after next AL-transaction commit */ + LIST_HEAD(busy); /* blocked by resync requests */ + + /* grab new incoming requests */ + spin_lock_irq(&device->resource->req_lock); + list_splice_tail_init(&device->submit.writes, &incoming); + spin_unlock_irq(&device->resource->req_lock); for (;;) { - spin_lock(&mdev->submit.lock); - list_splice_tail_init(&mdev->submit.writes, &incoming); - spin_unlock(&mdev->submit.lock); + DEFINE_WAIT(wait); - submit_fast_path(mdev, &incoming); + /* move used-to-be-busy back to front of incoming */ + list_splice_init(&busy, &incoming); + submit_fast_path(device, &incoming); if (list_empty(&incoming)) break; - wait_event(mdev->al_wait, prepare_al_transaction_nonblock(mdev, &incoming, &pending)); - /* Maybe more was queued, while we prepared the transaction? - * Try to stuff them into this transaction as well. - * Be strictly non-blocking here, no wait_event, we already - * have something to commit. - * Stop if we don't make any more progres. - */ for (;;) { + prepare_to_wait(&device->al_wait, &wait, TASK_UNINTERRUPTIBLE); + + list_splice_init(&busy, &incoming); + prepare_al_transaction_nonblock(device, &incoming, &pending, &busy); + if (!list_empty(&pending)) + break; + + schedule(); + + /* If all currently "hot" activity log extents are kept busy by + * incoming requests, we still must not totally starve new + * requests to "cold" extents. + * Something left on &incoming means there had not been + * enough update slots available, and the activity log + * has been marked as "starving". + * + * Try again now, without looking for new requests, + * effectively blocking all new requests until we made + * at least _some_ progress with what we currently have. + */ + if (!list_empty(&incoming)) + continue; + + /* Nothing moved to pending, but nothing left + * on incoming: all moved to busy! + * Grab new and iterate. */ + spin_lock_irq(&device->resource->req_lock); + list_splice_tail_init(&device->submit.writes, &incoming); + spin_unlock_irq(&device->resource->req_lock); + } + finish_wait(&device->al_wait, &wait); + + /* If the transaction was full, before all incoming requests + * had been processed, skip ahead to commit, and iterate + * without splicing in more incoming requests from upper layers. + * + * Else, if all incoming have been processed, + * they have become either "pending" (to be submitted after + * next transaction commit) or "busy" (blocked by resync). + * + * Maybe more was queued, while we prepared the transaction? + * Try to stuff those into this transaction as well. + * Be strictly non-blocking here, + * we already have something to commit. + * + * Commit if we don't make any more progres. + */ + + while (list_empty(&incoming)) { LIST_HEAD(more_pending); LIST_HEAD(more_incoming); bool made_progress; /* It is ok to look outside the lock, * it's only an optimization anyways */ - if (list_empty(&mdev->submit.writes)) + if (list_empty(&device->submit.writes)) break; - spin_lock(&mdev->submit.lock); - list_splice_tail_init(&mdev->submit.writes, &more_incoming); - spin_unlock(&mdev->submit.lock); + spin_lock_irq(&device->resource->req_lock); + list_splice_tail_init(&device->submit.writes, &more_incoming); + spin_unlock_irq(&device->resource->req_lock); if (list_empty(&more_incoming)) break; - made_progress = prepare_al_transaction_nonblock(mdev, &more_incoming, &more_pending); + made_progress = prepare_al_transaction_nonblock(device, &more_incoming, &more_pending, &busy); list_splice_tail_init(&more_pending, &pending); list_splice_tail_init(&more_incoming, &incoming); - if (!made_progress) break; } - drbd_al_begin_io_commit(mdev, false); - list_for_each_entry_safe(req, tmp, &pending, tl_requests) { - list_del_init(&req->tl_requests); - drbd_send_and_submit(mdev, req); - } + drbd_al_begin_io_commit(device); + send_and_submit_pending(device, &pending); } } -void drbd_make_request(struct request_queue *q, struct bio *bio) +void drbd_submit_bio(struct bio *bio) { - struct drbd_conf *mdev = (struct drbd_conf *) q->queuedata; - unsigned long start_time; + struct drbd_device *device = bio->bi_bdev->bd_disk->private_data; - start_time = jiffies; + bio = bio_split_to_limits(bio); + if (!bio) + return; /* * what we "blindly" assume: */ - D_ASSERT(IS_ALIGNED(bio->bi_size, 512)); + D_ASSERT(device, IS_ALIGNED(bio->bi_iter.bi_size, 512)); - inc_ap_bio(mdev); - __drbd_make_request(mdev, bio, start_time); + inc_ap_bio(device); + __drbd_make_request(device, bio); } -/* This is called by bio_add_page(). - * - * q->max_hw_sectors and other global limits are already enforced there. - * - * We need to call down to our lower level device, - * in case it has special restrictions. - * - * We also may need to enforce configured max-bio-bvecs limits. - * - * As long as the BIO is empty we have to allow at least one bvec, - * regardless of size and offset, so no need to ask lower levels. - */ -int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec) +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_conf *mdev = (struct drbd_conf *) q->queuedata; - unsigned int bio_size = bvm->bi_size; - int limit = DRBD_MAX_BIO_SIZE; - int backing_limit; - - if (bio_size && get_ldev(mdev)) { - struct request_queue * const b = - mdev->ldev->backing_bdev->bd_disk->queue; - if (b->merge_bvec_fn) { - backing_limit = b->merge_bvec_fn(b, bvm, bvec); - limit = min(limit, backing_limit); - } - put_ldev(mdev); + 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; } - return limit; -} -struct drbd_request *find_oldest_request(struct drbd_tconn *tconn) -{ - /* Walk the transfer log, - * and find the oldest not yet completed request */ - struct drbd_request *r; - list_for_each_entry(r, &tconn->transfer_log, tl_requests) { - if (atomic_read(&r->completion_ref)) - return r; + /* 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; } - return NULL; + + /* 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; } -void request_timer_fn(unsigned long data) +/* 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(struct timer_list *t) { - struct drbd_conf *mdev = (struct drbd_conf *) data; - struct drbd_tconn *tconn = mdev->tconn; - struct drbd_request *req; /* oldest request */ + struct drbd_device *device = timer_container_of(device, t, + request_timer); + struct drbd_connection *connection = first_peer_device(device)->connection; + struct drbd_request *req_read, *req_write, *req_peer; /* oldest request */ struct net_conf *nc; + 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(tconn->net_conf); - if (nc && mdev->state.conn >= C_WF_REPORT_PARAMS) - ent = nc->timeout * HZ/10 * nc->ko_count; + nc = rcu_dereference(connection->net_conf); + if (nc && device->state.conn >= C_WF_REPORT_PARAMS) { + ko_count = nc->ko_count; + timeout = nc->timeout; + } - if (get_ldev(mdev)) { /* implicit state.disk >= D_INCONSISTENT */ - dt = rcu_dereference(mdev->ldev->disk_conf)->disk_timeout * HZ / 10; - put_ldev(mdev); + if (get_ldev(device)) { /* implicit state.disk >= D_INCONSISTENT */ + dt = rcu_dereference(device->ldev->disk_conf)->disk_timeout * HZ / 10; + put_ldev(device); } rcu_read_unlock(); + + ent = timeout * HZ/10 * ko_count; et = min_not_zero(dt, ent); if (!et) return; /* Recurring timer stopped */ now = jiffies; + nt = now + et; - spin_lock_irq(&tconn->req_lock); - req = find_oldest_request(tconn); - if (!req) { - spin_unlock_irq(&tconn->req_lock); - mod_timer(&mdev->request_timer, now + et); - return; - } + 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); - /* 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. + /* maybe the oldest request waiting for the peer is in fact still + * 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(). */ - if (ent && req->rq_state & RQ_NET_PENDING && - time_after(now, req->start_time + ent) && - !time_in_range(now, tconn->last_reconnect_jif, tconn->last_reconnect_jif + ent)) { - dev_warn(DEV, "Remote failed to finish a request within ko-count * timeout\n"); - _drbd_set_state(_NS(mdev, conn, C_TIMEOUT), CS_VERBOSE | CS_HARD, NULL); - } - if (dt && req->rq_state & RQ_LOCAL_PENDING && req->w.mdev == mdev && - time_after(now, req->start_time + dt) && - !time_in_range(now, mdev->last_reattach_jif, mdev->last_reattach_jif + dt)) { - dev_warn(DEV, "Local backing device failed to meet the disk-timeout\n"); - __drbd_chk_io_error(mdev, DRBD_FORCE_DETACH); + + /* 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) + req_peer = NULL; + + /* do we have something to evaluate? */ + if (req_peer == NULL && req_write == NULL && req_read == NULL) + goto out; + + oldest_submit_jif = + (req_write && req_read) + ? ( time_before(req_write->pre_submit_jif, req_read->pre_submit_jif) + ? req_write->pre_submit_jif : req_read->pre_submit_jif ) + : req_write ? req_write->pre_submit_jif + : req_read ? req_read->pre_submit_jif : now; + + 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)) { + drbd_warn(device, "Local backing device failed to meet the disk-timeout\n"); + __drbd_chk_io_error(device, DRBD_FORCE_DETACH); } - nt = (time_after(now, req->start_time + et) ? now : req->start_time) + et; - spin_unlock_irq(&tconn->req_lock); - mod_timer(&mdev->request_timer, nt); + + /* Reschedule timer for the nearest not already expired timeout. + * Fallback to now + min(effective network timeout, disk timeout). */ + ent = (ent && req_peer && time_before(now, req_peer->pre_send_jif + ent)) + ? req_peer->pre_send_jif + ent : now + et; + dt = (dt && oldest_submit_jif != now && time_before(now, oldest_submit_jif + dt)) + ? oldest_submit_jif + dt : now + et; + nt = time_before(ent, dt) ? ent : dt; +out: + spin_unlock_irq(&device->resource->req_lock); + mod_timer(&device->request_timer, nt); } |