/* drbd_worker.c This file is part of DRBD by Philipp Reisner and Lars Ellenberg. Copyright (C) 2001-2008, LINBIT Information Technologies GmbH. Copyright (C) 1999-2008, Philipp Reisner . Copyright (C) 2002-2008, Lars Ellenberg . 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "drbd_int.h" #include "drbd_req.h" #define SLEEP_TIME (HZ/10) static int w_make_ov_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel); /* defined here: drbd_md_io_complete drbd_endio_sec drbd_endio_pri * more endio handlers: atodb_endio in drbd_actlog.c drbd_bm_async_io_complete in drbd_bitmap.c * For all these callbacks, note the following: * The callbacks will be called in irq context by the IDE drivers, * and in Softirqs/Tasklets/BH context by the SCSI drivers. * Try to get the locking right :) * */ /* About the global_state_lock Each state transition on an device holds a read lock. In case we have to evaluate the sync after dependencies, we grab a write lock, because we need stable states on all devices for that. */ rwlock_t global_state_lock; /* used for synchronous meta data and bitmap IO * submitted by drbd_md_sync_page_io() */ void drbd_md_io_complete(struct bio *bio, int error) { struct drbd_md_io *md_io; md_io = (struct drbd_md_io *)bio->bi_private; md_io->error = error; complete(&md_io->event); } /* reads on behalf of the partner, * "submitted" by the receiver */ void drbd_endio_read_sec_final(struct drbd_epoch_entry *e) __releases(local) { unsigned long flags = 0; struct drbd_conf *mdev = e->mdev; D_ASSERT(e->block_id != ID_VACANT); spin_lock_irqsave(&mdev->req_lock, flags); mdev->read_cnt += e->size >> 9; list_del(&e->w.list); if (list_empty(&mdev->read_ee)) wake_up(&mdev->ee_wait); if (test_bit(__EE_WAS_ERROR, &e->flags)) __drbd_chk_io_error(mdev, FALSE); spin_unlock_irqrestore(&mdev->req_lock, flags); drbd_queue_work(&mdev->data.work, &e->w); put_ldev(mdev); } static int is_failed_barrier(int ee_flags) { return (ee_flags & (EE_IS_BARRIER|EE_WAS_ERROR|EE_RESUBMITTED)) == (EE_IS_BARRIER|EE_WAS_ERROR); } /* writes on behalf of the partner, or resync writes, * "submitted" by the receiver, final stage. */ static void drbd_endio_write_sec_final(struct drbd_epoch_entry *e) __releases(local) { unsigned long flags = 0; struct drbd_conf *mdev = e->mdev; sector_t e_sector; int do_wake; int is_syncer_req; int do_al_complete_io; /* if this is a failed barrier request, disable use of barriers, * and schedule for resubmission */ if (is_failed_barrier(e->flags)) { drbd_bump_write_ordering(mdev, WO_bdev_flush); spin_lock_irqsave(&mdev->req_lock, flags); list_del(&e->w.list); e->flags = (e->flags & ~EE_WAS_ERROR) | EE_RESUBMITTED; e->w.cb = w_e_reissue; /* put_ldev actually happens below, once we come here again. */ __release(local); spin_unlock_irqrestore(&mdev->req_lock, flags); drbd_queue_work(&mdev->data.work, &e->w); return; } D_ASSERT(e->block_id != ID_VACANT); /* after we moved e to done_ee, * we may no longer access it, * it may be freed/reused already! * (as soon as we release the req_lock) */ e_sector = e->sector; do_al_complete_io = e->flags & EE_CALL_AL_COMPLETE_IO; is_syncer_req = is_syncer_block_id(e->block_id); spin_lock_irqsave(&mdev->req_lock, flags); mdev->writ_cnt += e->size >> 9; list_del(&e->w.list); /* has been on active_ee or sync_ee */ list_add_tail(&e->w.list, &mdev->done_ee); /* No hlist_del_init(&e->colision) here, we did not send the Ack yet, * neither did we wake possibly waiting conflicting requests. * done from "drbd_process_done_ee" within the appropriate w.cb * (e_end_block/e_end_resync_block) or from _drbd_clear_done_ee */ do_wake = is_syncer_req ? list_empty(&mdev->sync_ee) : list_empty(&mdev->active_ee); if (test_bit(__EE_WAS_ERROR, &e->flags)) __drbd_chk_io_error(mdev, FALSE); spin_unlock_irqrestore(&mdev->req_lock, flags); if (is_syncer_req) drbd_rs_complete_io(mdev, e_sector); if (do_wake) wake_up(&mdev->ee_wait); if (do_al_complete_io) drbd_al_complete_io(mdev, e_sector); wake_asender(mdev); put_ldev(mdev); } /* writes on behalf of the partner, or resync writes, * "submitted" by the receiver. */ void drbd_endio_sec(struct bio *bio, int error) { struct drbd_epoch_entry *e = bio->bi_private; struct drbd_conf *mdev = e->mdev; int uptodate = bio_flagged(bio, BIO_UPTODATE); int is_write = bio_data_dir(bio) == WRITE; if (error) dev_warn(DEV, "%s: error=%d s=%llus\n", is_write ? "write" : "read", error, (unsigned long long)e->sector); if (!error && !uptodate) { dev_warn(DEV, "%s: setting error to -EIO s=%llus\n", is_write ? "write" : "read", (unsigned long long)e->sector); /* strange behavior of some lower level drivers... * fail the request by clearing the uptodate flag, * but do not return any error?! */ error = -EIO; } if (error) set_bit(__EE_WAS_ERROR, &e->flags); bio_put(bio); /* no need for the bio anymore */ if (atomic_dec_and_test(&e->pending_bios)) { if (is_write) drbd_endio_write_sec_final(e); else drbd_endio_read_sec_final(e); } } /* read, readA or write requests on R_PRIMARY coming from drbd_make_request */ void drbd_endio_pri(struct bio *bio, int error) { unsigned long flags; struct drbd_request *req = bio->bi_private; struct drbd_conf *mdev = req->mdev; struct bio_and_error m; enum drbd_req_event what; int uptodate = bio_flagged(bio, BIO_UPTODATE); if (!error && !uptodate) { dev_warn(DEV, "p %s: setting error to -EIO\n", bio_data_dir(bio) == WRITE ? "write" : "read"); /* strange behavior of some lower level drivers... * fail the request by clearing the uptodate flag, * but do not return any error?! */ error = -EIO; } /* to avoid recursion in __req_mod */ if (unlikely(error)) { what = (bio_data_dir(bio) == WRITE) ? write_completed_with_error : (bio_rw(bio) == READ) ? read_completed_with_error : read_ahead_completed_with_error; } else what = completed_ok; bio_put(req->private_bio); req->private_bio = ERR_PTR(error); spin_lock_irqsave(&mdev->req_lock, flags); __req_mod(req, what, &m); spin_unlock_irqrestore(&mdev->req_lock, flags); if (m.bio) complete_master_bio(mdev, &m); } int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_request *req = container_of(w, struct drbd_request, w); /* We should not detach for read io-error, * but try to WRITE the P_DATA_REPLY to the failed location, * to give the disk the chance to relocate that block */ spin_lock_irq(&mdev->req_lock); if (cancel || mdev->state.pdsk != D_UP_TO_DATE) { _req_mod(req, read_retry_remote_canceled); spin_unlock_irq(&mdev->req_lock); return 1; } spin_unlock_irq(&mdev->req_lock); return w_send_read_req(mdev, w, 0); } int w_resync_inactive(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { ERR_IF(cancel) return 1; dev_err(DEV, "resync inactive, but callback triggered??\n"); return 1; /* Simply ignore this! */ } void drbd_csum_ee(struct drbd_conf *mdev, struct crypto_hash *tfm, struct drbd_epoch_entry *e, void *digest) { struct hash_desc desc; struct scatterlist sg; struct page *page = e->pages; struct page *tmp; unsigned len; desc.tfm = tfm; desc.flags = 0; sg_init_table(&sg, 1); crypto_hash_init(&desc); while ((tmp = page_chain_next(page))) { /* all but the last page will be fully used */ sg_set_page(&sg, page, PAGE_SIZE, 0); crypto_hash_update(&desc, &sg, sg.length); page = tmp; } /* and now the last, possibly only partially used page */ len = e->size & (PAGE_SIZE - 1); sg_set_page(&sg, page, len ?: PAGE_SIZE, 0); crypto_hash_update(&desc, &sg, sg.length); crypto_hash_final(&desc, digest); } void drbd_csum_bio(struct drbd_conf *mdev, struct crypto_hash *tfm, struct bio *bio, void *digest) { struct hash_desc desc; struct scatterlist sg; struct bio_vec *bvec; int i; desc.tfm = tfm; desc.flags = 0; sg_init_table(&sg, 1); crypto_hash_init(&desc); __bio_for_each_segment(bvec, bio, i, 0) { sg_set_page(&sg, bvec->bv_page, bvec->bv_len, bvec->bv_offset); crypto_hash_update(&desc, &sg, sg.length); } crypto_hash_final(&desc, digest); } static int w_e_send_csum(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w); int digest_size; void *digest; int ok; D_ASSERT(e->block_id == DRBD_MAGIC + 0xbeef); if (unlikely(cancel)) { drbd_free_ee(mdev, e); return 1; } if (likely((e->flags & EE_WAS_ERROR) == 0)) { digest_size = crypto_hash_digestsize(mdev->csums_tfm); digest = kmalloc(digest_size, GFP_NOIO); if (digest) { drbd_csum_ee(mdev, mdev->csums_tfm, e, digest); inc_rs_pending(mdev); ok = drbd_send_drequest_csum(mdev, e->sector, e->size, digest, digest_size, P_CSUM_RS_REQUEST); kfree(digest); } else { dev_err(DEV, "kmalloc() of digest failed.\n"); ok = 0; } } else ok = 1; drbd_free_ee(mdev, e); if (unlikely(!ok)) dev_err(DEV, "drbd_send_drequest(..., csum) failed\n"); return ok; } #define GFP_TRY (__GFP_HIGHMEM | __GFP_NOWARN) static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size) { struct drbd_epoch_entry *e; if (!get_ldev(mdev)) return 0; /* GFP_TRY, because if there is no memory available right now, this may * be rescheduled for later. It is "only" background resync, after all. */ e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY); if (!e) goto fail; spin_lock_irq(&mdev->req_lock); list_add(&e->w.list, &mdev->read_ee); spin_unlock_irq(&mdev->req_lock); e->w.cb = w_e_send_csum; if (drbd_submit_ee(mdev, e, READ, DRBD_FAULT_RS_RD) == 0) return 1; drbd_free_ee(mdev, e); fail: put_ldev(mdev); return 2; } void resync_timer_fn(unsigned long data) { unsigned long flags; struct drbd_conf *mdev = (struct drbd_conf *) data; int queue; spin_lock_irqsave(&mdev->req_lock, flags); if (likely(!test_and_clear_bit(STOP_SYNC_TIMER, &mdev->flags))) { queue = 1; if (mdev->state.conn == C_VERIFY_S) mdev->resync_work.cb = w_make_ov_request; else mdev->resync_work.cb = w_make_resync_request; } else { queue = 0; mdev->resync_work.cb = w_resync_inactive; } spin_unlock_irqrestore(&mdev->req_lock, flags); /* harmless race: list_empty outside data.work.q_lock */ if (list_empty(&mdev->resync_work.list) && queue) drbd_queue_work(&mdev->data.work, &mdev->resync_work); } static int calc_resync_rate(struct drbd_conf *mdev) { int d = mdev->data_delay / 1000; /* us -> ms */ int td = mdev->sync_conf.throttle_th * 100; /* 0.1s -> ms */ int hd = mdev->sync_conf.hold_off_th * 100; /* 0.1s -> ms */ int cr = mdev->sync_conf.rate; return d <= td ? cr : d >= hd ? 0 : cr + (cr * (td - d) / (hd - td)); } int w_make_resync_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { unsigned long bit; sector_t sector; const sector_t capacity = drbd_get_capacity(mdev->this_bdev); int max_segment_size; int number, i, size, pe, mx; int align, queued, sndbuf; if (unlikely(cancel)) return 1; if (unlikely(mdev->state.conn < C_CONNECTED)) { dev_err(DEV, "Confused in w_make_resync_request()! cstate < Connected"); return 0; } if (mdev->state.conn != C_SYNC_TARGET) dev_err(DEV, "%s in w_make_resync_request\n", drbd_conn_str(mdev->state.conn)); if (!get_ldev(mdev)) { /* Since we only need to access mdev->rsync a get_ldev_if_state(mdev,D_FAILED) would be sufficient, but to continue resync with a broken disk makes no sense at all */ dev_err(DEV, "Disk broke down during resync!\n"); mdev->resync_work.cb = w_resync_inactive; return 1; } /* starting with drbd 8.3.8, we can handle multi-bio EEs, * if it should be necessary */ max_segment_size = mdev->agreed_pro_version < 94 ? queue_max_segment_size(mdev->rq_queue) : DRBD_MAX_SEGMENT_SIZE; mdev->c_sync_rate = calc_resync_rate(mdev); number = SLEEP_TIME * mdev->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ); pe = atomic_read(&mdev->rs_pending_cnt); mutex_lock(&mdev->data.mutex); if (mdev->data.socket) mx = mdev->data.socket->sk->sk_rcvbuf / sizeof(struct p_block_req); else mx = 1; mutex_unlock(&mdev->data.mutex); /* For resync rates >160MB/sec, allow more pending RS requests */ if (number > mx) mx = number; /* Limit the number of pending RS requests to no more than the peer's receive buffer */ if ((pe + number) > mx) { number = mx - pe; } for (i = 0; i < number; i++) { /* Stop generating RS requests, when half of the send buffer is filled */ mutex_lock(&mdev->data.mutex); if (mdev->data.socket) { queued = mdev->data.socket->sk->sk_wmem_queued; sndbuf = mdev->data.socket->sk->sk_sndbuf; } else { queued = 1; sndbuf = 0; } mutex_unlock(&mdev->data.mutex); if (queued > sndbuf / 2) goto requeue; next_sector: size = BM_BLOCK_SIZE; bit = drbd_bm_find_next(mdev, mdev->bm_resync_fo); if (bit == -1UL) { mdev->bm_resync_fo = drbd_bm_bits(mdev); mdev->resync_work.cb = w_resync_inactive; put_ldev(mdev); return 1; } sector = BM_BIT_TO_SECT(bit); if (drbd_try_rs_begin_io(mdev, sector)) { mdev->bm_resync_fo = bit; goto requeue; } mdev->bm_resync_fo = bit + 1; if (unlikely(drbd_bm_test_bit(mdev, bit) == 0)) { drbd_rs_complete_io(mdev, sector); goto next_sector; } #if DRBD_MAX_SEGMENT_SIZE > BM_BLOCK_SIZE /* try to find some adjacent bits. * we stop if we have already the maximum req size. * * Additionally always align bigger requests, in order to * be prepared for all stripe sizes of software RAIDs. */ align = 1; for (;;) { if (size + BM_BLOCK_SIZE > max_segment_size) break; /* Be always aligned */ if (sector & ((1<<(align+3))-1)) break; /* do not cross extent boundaries */ if (((bit+1) & BM_BLOCKS_PER_BM_EXT_MASK) == 0) break; /* now, is it actually dirty, after all? * caution, drbd_bm_test_bit is tri-state for some * obscure reason; ( b == 0 ) would get the out-of-band * only accidentally right because of the "oddly sized" * adjustment below */ if (drbd_bm_test_bit(mdev, bit+1) != 1) break; bit++; size += BM_BLOCK_SIZE; if ((BM_BLOCK_SIZE << align) <= size) align++; i++; } /* if we merged some, * reset the offset to start the next drbd_bm_find_next from */ if (size > BM_BLOCK_SIZE) mdev->bm_resync_fo = bit + 1; #endif /* adjust very last sectors, in case we are oddly sized */ if (sector + (size>>9) > capacity) size = (capacity-sector)<<9; if (mdev->agreed_pro_version >= 89 && mdev->csums_tfm) { switch (read_for_csum(mdev, sector, size)) { case 0: /* Disk failure*/ put_ldev(mdev); return 0; case 2: /* Allocation failed */ drbd_rs_complete_io(mdev, sector); mdev->bm_resync_fo = BM_SECT_TO_BIT(sector); goto requeue; /* case 1: everything ok */ } } else { inc_rs_pending(mdev); if (!drbd_send_drequest(mdev, P_RS_DATA_REQUEST, sector, size, ID_SYNCER)) { dev_err(DEV, "drbd_send_drequest() failed, aborting...\n"); dec_rs_pending(mdev); put_ldev(mdev); return 0; } } } if (mdev->bm_resync_fo >= drbd_bm_bits(mdev)) { /* last syncer _request_ was sent, * but the P_RS_DATA_REPLY not yet received. sync will end (and * next sync group will resume), as soon as we receive the last * resync data block, and the last bit is cleared. * until then resync "work" is "inactive" ... */ mdev->resync_work.cb = w_resync_inactive; put_ldev(mdev); return 1; } requeue: mod_timer(&mdev->resync_timer, jiffies + SLEEP_TIME); put_ldev(mdev); return 1; } static int w_make_ov_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { int number, i, size; sector_t sector; const sector_t capacity = drbd_get_capacity(mdev->this_bdev); if (unlikely(cancel)) return 1; if (unlikely(mdev->state.conn < C_CONNECTED)) { dev_err(DEV, "Confused in w_make_ov_request()! cstate < Connected"); return 0; } number = SLEEP_TIME*mdev->sync_conf.rate / ((BM_BLOCK_SIZE/1024)*HZ); if (atomic_read(&mdev->rs_pending_cnt) > number) goto requeue; number -= atomic_read(&mdev->rs_pending_cnt); sector = mdev->ov_position; for (i = 0; i < number; i++) { if (sector >= capacity) { mdev->resync_work.cb = w_resync_inactive; return 1; } size = BM_BLOCK_SIZE; if (drbd_try_rs_begin_io(mdev, sector)) { mdev->ov_position = sector; goto requeue; } if (sector + (size>>9) > capacity) size = (capacity-sector)<<9; inc_rs_pending(mdev); if (!drbd_send_ov_request(mdev, sector, size)) { dec_rs_pending(mdev); return 0; } sector += BM_SECT_PER_BIT; } mdev->ov_position = sector; requeue: mod_timer(&mdev->resync_timer, jiffies + SLEEP_TIME); return 1; } int w_ov_finished(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { kfree(w); ov_oos_print(mdev); drbd_resync_finished(mdev); return 1; } static int w_resync_finished(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { kfree(w); drbd_resync_finished(mdev); return 1; } int drbd_resync_finished(struct drbd_conf *mdev) { unsigned long db, dt, dbdt; unsigned long n_oos; union drbd_state os, ns; struct drbd_work *w; char *khelper_cmd = NULL; /* Remove all elements from the resync LRU. Since future actions * might set bits in the (main) bitmap, then the entries in the * resync LRU would be wrong. */ if (drbd_rs_del_all(mdev)) { /* In case this is not possible now, most probably because * there are P_RS_DATA_REPLY Packets lingering on the worker's * queue (or even the read operations for those packets * is not finished by now). Retry in 100ms. */ drbd_kick_lo(mdev); __set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(HZ / 10); w = kmalloc(sizeof(struct drbd_work), GFP_ATOMIC); if (w) { w->cb = w_resync_finished; drbd_queue_work(&mdev->data.work, w); return 1; } dev_err(DEV, "Warn failed to drbd_rs_del_all() and to kmalloc(w).\n"); } dt = (jiffies - mdev->rs_start - mdev->rs_paused) / HZ; if (dt <= 0) dt = 1; db = mdev->rs_total; dbdt = Bit2KB(db/dt); mdev->rs_paused /= HZ; if (!get_ldev(mdev)) goto out; spin_lock_irq(&mdev->req_lock); os = mdev->state; /* This protects us against multiple calls (that can happen in the presence of application IO), and against connectivity loss just before we arrive here. */ if (os.conn <= C_CONNECTED) goto out_unlock; ns = os; ns.conn = C_CONNECTED; dev_info(DEV, "%s done (total %lu sec; paused %lu sec; %lu K/sec)\n", (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) ? "Online verify " : "Resync", dt + mdev->rs_paused, mdev->rs_paused, dbdt); n_oos = drbd_bm_total_weight(mdev); if (os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) { if (n_oos) { dev_alert(DEV, "Online verify found %lu %dk block out of sync!\n", n_oos, Bit2KB(1)); khelper_cmd = "out-of-sync"; } } else { D_ASSERT((n_oos - mdev->rs_failed) == 0); if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) khelper_cmd = "after-resync-target"; if (mdev->csums_tfm && mdev->rs_total) { const unsigned long s = mdev->rs_same_csum; const unsigned long t = mdev->rs_total; const int ratio = (t == 0) ? 0 : (t < 100000) ? ((s*100)/t) : (s/(t/100)); dev_info(DEV, "%u %% had equal check sums, eliminated: %luK; " "transferred %luK total %luK\n", ratio, Bit2KB(mdev->rs_same_csum), Bit2KB(mdev->rs_total - mdev->rs_same_csum), Bit2KB(mdev->rs_total)); } } if (mdev->rs_failed) { dev_info(DEV, " %lu failed blocks\n", mdev->rs_failed); if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) { ns.disk = D_INCONSISTENT; ns.pdsk = D_UP_TO_DATE; } else { ns.disk = D_UP_TO_DATE; ns.pdsk = D_INCONSISTENT; } } else { ns.disk = D_UP_TO_DATE; ns.pdsk = D_UP_TO_DATE; if (os.conn == C_SYNC_TARGET || os.conn == C_PAUSED_SYNC_T) { if (mdev->p_uuid) { int i; for (i = UI_BITMAP ; i <= UI_HISTORY_END ; i++) _drbd_uuid_set(mdev, i, mdev->p_uuid[i]); drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_CURRENT]); _drbd_uuid_set(mdev, UI_CURRENT, mdev->p_uuid[UI_CURRENT]); } else { dev_err(DEV, "mdev->p_uuid is NULL! BUG\n"); } } drbd_uuid_set_bm(mdev, 0UL); if (mdev->p_uuid) { /* Now the two UUID sets are equal, update what we * know of the peer. */ int i; for (i = UI_CURRENT ; i <= UI_HISTORY_END ; i++) mdev->p_uuid[i] = mdev->ldev->md.uuid[i]; } } _drbd_set_state(mdev, ns, CS_VERBOSE, NULL); out_unlock: spin_unlock_irq(&mdev->req_lock); put_ldev(mdev); out: mdev->rs_total = 0; mdev->rs_failed = 0; mdev->rs_paused = 0; mdev->ov_start_sector = 0; if (test_and_clear_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags)) { dev_warn(DEV, "Writing the whole bitmap, due to failed kmalloc\n"); drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished"); } if (khelper_cmd) drbd_khelper(mdev, khelper_cmd); return 1; } /* helper */ static void move_to_net_ee_or_free(struct drbd_conf *mdev, struct drbd_epoch_entry *e) { if (drbd_ee_has_active_page(e)) { /* This might happen if sendpage() has not finished */ spin_lock_irq(&mdev->req_lock); list_add_tail(&e->w.list, &mdev->net_ee); spin_unlock_irq(&mdev->req_lock); } else drbd_free_ee(mdev, e); } /** * w_e_end_data_req() - Worker callback, to send a P_DATA_REPLY packet in response to a P_DATA_REQUEST * @mdev: DRBD device. * @w: work object. * @cancel: The connection will be closed anyways */ int w_e_end_data_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w); int ok; if (unlikely(cancel)) { drbd_free_ee(mdev, e); dec_unacked(mdev); return 1; } if (likely((e->flags & EE_WAS_ERROR) == 0)) { ok = drbd_send_block(mdev, P_DATA_REPLY, e); } else { if (__ratelimit(&drbd_ratelimit_state)) dev_err(DEV, "Sending NegDReply. sector=%llus.\n", (unsigned long long)e->sector); ok = drbd_send_ack(mdev, P_NEG_DREPLY, e); } dec_unacked(mdev); move_to_net_ee_or_free(mdev, e); if (unlikely(!ok)) dev_err(DEV, "drbd_send_block() failed\n"); return ok; } /** * w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUESTRS * @mdev: DRBD device. * @w: work object. * @cancel: The connection will be closed anyways */ int w_e_end_rsdata_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w); int ok; if (unlikely(cancel)) { drbd_free_ee(mdev, e); dec_unacked(mdev); return 1; } if (get_ldev_if_state(mdev, D_FAILED)) { drbd_rs_complete_io(mdev, e->sector); put_ldev(mdev); } if (likely((e->flags & EE_WAS_ERROR) == 0)) { if (likely(mdev->state.pdsk >= D_INCONSISTENT)) { inc_rs_pending(mdev); ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e); } else { if (__ratelimit(&drbd_ratelimit_state)) dev_err(DEV, "Not sending RSDataReply, " "partner DISKLESS!\n"); ok = 1; } } else { if (__ratelimit(&drbd_ratelimit_state)) dev_err(DEV, "Sending NegRSDReply. sector %llus.\n", (unsigned long long)e->sector); ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e); /* update resync data with failure */ drbd_rs_failed_io(mdev, e->sector, e->size); } dec_unacked(mdev); move_to_net_ee_or_free(mdev, e); if (unlikely(!ok)) dev_err(DEV, "drbd_send_block() failed\n"); return ok; } int w_e_end_csum_rs_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w); struct digest_info *di; int digest_size; void *digest = NULL; int ok, eq = 0; if (unlikely(cancel)) { drbd_free_ee(mdev, e); dec_unacked(mdev); return 1; } drbd_rs_complete_io(mdev, e->sector); di = (struct digest_info *)(unsigned long)e->block_id; if (likely((e->flags & EE_WAS_ERROR) == 0)) { /* quick hack to try to avoid a race against reconfiguration. * a real fix would be much more involved, * introducing more locking mechanisms */ if (mdev->csums_tfm) { digest_size = crypto_hash_digestsize(mdev->csums_tfm); D_ASSERT(digest_size == di->digest_size); digest = kmalloc(digest_size, GFP_NOIO); } if (digest) { drbd_csum_ee(mdev, mdev->csums_tfm, e, digest); eq = !memcmp(digest, di->digest, digest_size); kfree(digest); } if (eq) { drbd_set_in_sync(mdev, e->sector, e->size); /* rs_same_csums unit is BM_BLOCK_SIZE */ mdev->rs_same_csum += e->size >> BM_BLOCK_SHIFT; ok = drbd_send_ack(mdev, P_RS_IS_IN_SYNC, e); } else { inc_rs_pending(mdev); e->block_id = ID_SYNCER; ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e); } } else { ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e); if (__ratelimit(&drbd_ratelimit_state)) dev_err(DEV, "Sending NegDReply. I guess it gets messy.\n"); } dec_unacked(mdev); kfree(di); move_to_net_ee_or_free(mdev, e); if (unlikely(!ok)) dev_err(DEV, "drbd_send_block/ack() failed\n"); return ok; } int w_e_end_ov_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w); int digest_size; void *digest; int ok = 1; if (unlikely(cancel)) goto out; if (unlikely((e->flags & EE_WAS_ERROR) != 0)) goto out; digest_size = crypto_hash_digestsize(mdev->verify_tfm); /* FIXME if this allocation fails, online verify will not terminate! */ digest = kmalloc(digest_size, GFP_NOIO); if (digest) { drbd_csum_ee(mdev, mdev->verify_tfm, e, digest); inc_rs_pending(mdev); ok = drbd_send_drequest_csum(mdev, e->sector, e->size, digest, digest_size, P_OV_REPLY); if (!ok) dec_rs_pending(mdev); kfree(digest); } out: drbd_free_ee(mdev, e); dec_unacked(mdev); return ok; } void drbd_ov_oos_found(struct drbd_conf *mdev, sector_t sector, int size) { if (mdev->ov_last_oos_start + mdev->ov_last_oos_size == sector) { mdev->ov_last_oos_size += size>>9; } else { mdev->ov_last_oos_start = sector; mdev->ov_last_oos_size = size>>9; } drbd_set_out_of_sync(mdev, sector, size); set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags); } int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_epoch_entry *e = container_of(w, struct drbd_epoch_entry, w); struct digest_info *di; int digest_size; void *digest; int ok, eq = 0; if (unlikely(cancel)) { drbd_free_ee(mdev, e); dec_unacked(mdev); return 1; } /* after "cancel", because after drbd_disconnect/drbd_rs_cancel_all * the resync lru has been cleaned up already */ drbd_rs_complete_io(mdev, e->sector); di = (struct digest_info *)(unsigned long)e->block_id; if (likely((e->flags & EE_WAS_ERROR) == 0)) { digest_size = crypto_hash_digestsize(mdev->verify_tfm); digest = kmalloc(digest_size, GFP_NOIO); if (digest) { drbd_csum_ee(mdev, mdev->verify_tfm, e, digest); D_ASSERT(digest_size == di->digest_size); eq = !memcmp(digest, di->digest, digest_size); kfree(digest); } } else { ok = drbd_send_ack(mdev, P_NEG_RS_DREPLY, e); if (__ratelimit(&drbd_ratelimit_state)) dev_err(DEV, "Sending NegDReply. I guess it gets messy.\n"); } dec_unacked(mdev); kfree(di); if (!eq) drbd_ov_oos_found(mdev, e->sector, e->size); else ov_oos_print(mdev); ok = drbd_send_ack_ex(mdev, P_OV_RESULT, e->sector, e->size, eq ? ID_IN_SYNC : ID_OUT_OF_SYNC); drbd_free_ee(mdev, e); if (--mdev->ov_left == 0) { ov_oos_print(mdev); drbd_resync_finished(mdev); } return ok; } int w_prev_work_done(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_wq_barrier *b = container_of(w, struct drbd_wq_barrier, w); complete(&b->done); return 1; } int w_send_barrier(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_tl_epoch *b = container_of(w, struct drbd_tl_epoch, w); struct p_barrier *p = &mdev->data.sbuf.barrier; int ok = 1; /* really avoid racing with tl_clear. w.cb may have been referenced * just before it was reassigned and re-queued, so double check that. * actually, this race was harmless, since we only try to send the * barrier packet here, and otherwise do nothing with the object. * but compare with the head of w_clear_epoch */ spin_lock_irq(&mdev->req_lock); if (w->cb != w_send_barrier || mdev->state.conn < C_CONNECTED) cancel = 1; spin_unlock_irq(&mdev->req_lock); if (cancel) return 1; if (!drbd_get_data_sock(mdev)) return 0; p->barrier = b->br_number; /* inc_ap_pending was done where this was queued. * dec_ap_pending will be done in got_BarrierAck * or (on connection loss) in w_clear_epoch. */ ok = _drbd_send_cmd(mdev, mdev->data.socket, P_BARRIER, (struct p_header *)p, sizeof(*p), 0); drbd_put_data_sock(mdev); return ok; } int w_send_write_hint(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { if (cancel) return 1; return drbd_send_short_cmd(mdev, P_UNPLUG_REMOTE); } /** * w_send_dblock() - Worker callback to send a P_DATA packet in order to mirror a write request * @mdev: DRBD device. * @w: work object. * @cancel: The connection will be closed anyways */ int w_send_dblock(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_request *req = container_of(w, struct drbd_request, w); int ok; if (unlikely(cancel)) { req_mod(req, send_canceled); return 1; } ok = drbd_send_dblock(mdev, req); req_mod(req, ok ? handed_over_to_network : send_failed); return ok; } /** * w_send_read_req() - Worker callback to send a read request (P_DATA_REQUEST) packet * @mdev: DRBD device. * @w: work object. * @cancel: The connection will be closed anyways */ int w_send_read_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { struct drbd_request *req = container_of(w, struct drbd_request, w); int ok; if (unlikely(cancel)) { req_mod(req, send_canceled); return 1; } ok = drbd_send_drequest(mdev, P_DATA_REQUEST, req->sector, req->size, (unsigned long)req); if (!ok) { /* ?? we set C_TIMEOUT or C_BROKEN_PIPE in drbd_send(); * so this is probably redundant */ if (mdev->state.conn >= C_CONNECTED) drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE)); } req_mod(req, ok ? handed_over_to_network : send_failed); return ok; } static int _drbd_may_sync_now(struct drbd_conf *mdev) { struct drbd_conf *odev = mdev; while (1) { if (odev->sync_conf.after == -1) return 1; odev = minor_to_mdev(odev->sync_conf.after); ERR_IF(!odev) return 1; if ((odev->state.conn >= C_SYNC_SOURCE && odev->state.conn <= C_PAUSED_SYNC_T) || odev->state.aftr_isp || odev->state.peer_isp || odev->state.user_isp) return 0; } } /** * _drbd_pause_after() - Pause resync on all devices that may not resync now * @mdev: DRBD device. * * Called from process context only (admin command and after_state_ch). */ static int _drbd_pause_after(struct drbd_conf *mdev) { struct drbd_conf *odev; int i, rv = 0; for (i = 0; i < minor_count; i++) { odev = minor_to_mdev(i); if (!odev) continue; if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS) continue; if (!_drbd_may_sync_now(odev)) rv |= (__drbd_set_state(_NS(odev, aftr_isp, 1), CS_HARD, NULL) != SS_NOTHING_TO_DO); } return rv; } /** * _drbd_resume_next() - Resume resync on all devices that may resync now * @mdev: DRBD device. * * Called from process context only (admin command and worker). */ static int _drbd_resume_next(struct drbd_conf *mdev) { struct drbd_conf *odev; int i, rv = 0; for (i = 0; i < minor_count; i++) { odev = minor_to_mdev(i); if (!odev) continue; if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS) continue; if (odev->state.aftr_isp) { if (_drbd_may_sync_now(odev)) rv |= (__drbd_set_state(_NS(odev, aftr_isp, 0), CS_HARD, NULL) != SS_NOTHING_TO_DO) ; } } return rv; } void resume_next_sg(struct drbd_conf *mdev) { write_lock_irq(&global_state_lock); _drbd_resume_next(mdev); write_unlock_irq(&global_state_lock); } void suspend_other_sg(struct drbd_conf *mdev) { write_lock_irq(&global_state_lock); _drbd_pause_after(mdev); write_unlock_irq(&global_state_lock); } static int sync_after_error(struct drbd_conf *mdev, int o_minor) { struct drbd_conf *odev; if (o_minor == -1) return NO_ERROR; if (o_minor < -1 || minor_to_mdev(o_minor) == NULL) return ERR_SYNC_AFTER; /* check for loops */ odev = minor_to_mdev(o_minor); while (1) { if (odev == mdev) return ERR_SYNC_AFTER_CYCLE; /* dependency chain ends here, no cycles. */ if (odev->sync_conf.after == -1) return NO_ERROR; /* follow the dependency chain */ odev = minor_to_mdev(odev->sync_conf.after); } } int drbd_alter_sa(struct drbd_conf *mdev, int na) { int changes; int retcode; write_lock_irq(&global_state_lock); retcode = sync_after_error(mdev, na); if (retcode == NO_ERROR) { mdev->sync_conf.after = na; do { changes = _drbd_pause_after(mdev); changes |= _drbd_resume_next(mdev); } while (changes); } write_unlock_irq(&global_state_lock); return retcode; } static void ping_peer(struct drbd_conf *mdev) { clear_bit(GOT_PING_ACK, &mdev->flags); request_ping(mdev); wait_event(mdev->misc_wait, test_bit(GOT_PING_ACK, &mdev->flags) || mdev->state.conn < C_CONNECTED); } /** * drbd_start_resync() - Start the resync process * @mdev: DRBD device. * @side: Either C_SYNC_SOURCE or C_SYNC_TARGET * * This function might bring you directly into one of the * C_PAUSED_SYNC_* states. */ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side) { union drbd_state ns; int r; if (mdev->state.conn >= C_SYNC_SOURCE) { dev_err(DEV, "Resync already running!\n"); return; } /* In case a previous resync run was aborted by an IO error/detach on the peer. */ drbd_rs_cancel_all(mdev); if (side == C_SYNC_TARGET) { /* Since application IO was locked out during C_WF_BITMAP_T and C_WF_SYNC_UUID we are still unmodified. Before going to C_SYNC_TARGET we check that we might make the data inconsistent. */ r = drbd_khelper(mdev, "before-resync-target"); r = (r >> 8) & 0xff; if (r > 0) { dev_info(DEV, "before-resync-target handler returned %d, " "dropping connection.\n", r); drbd_force_state(mdev, NS(conn, C_DISCONNECTING)); return; } } drbd_state_lock(mdev); if (!get_ldev_if_state(mdev, D_NEGOTIATING)) { drbd_state_unlock(mdev); return; } if (side == C_SYNC_TARGET) { mdev->bm_resync_fo = 0; } else /* side == C_SYNC_SOURCE */ { u64 uuid; get_random_bytes(&uuid, sizeof(u64)); drbd_uuid_set(mdev, UI_BITMAP, uuid); drbd_send_sync_uuid(mdev, uuid); D_ASSERT(mdev->state.disk == D_UP_TO_DATE); } write_lock_irq(&global_state_lock); ns = mdev->state; ns.aftr_isp = !_drbd_may_sync_now(mdev); ns.conn = side; if (side == C_SYNC_TARGET) ns.disk = D_INCONSISTENT; else /* side == C_SYNC_SOURCE */ ns.pdsk = D_INCONSISTENT; r = __drbd_set_state(mdev, ns, CS_VERBOSE, NULL); ns = mdev->state; if (ns.conn < C_CONNECTED) r = SS_UNKNOWN_ERROR; if (r == SS_SUCCESS) { mdev->rs_total = mdev->rs_mark_left = drbd_bm_total_weight(mdev); mdev->rs_failed = 0; mdev->rs_paused = 0; mdev->rs_start = mdev->rs_mark_time = jiffies; mdev->rs_same_csum = 0; _drbd_pause_after(mdev); } write_unlock_irq(&global_state_lock); put_ldev(mdev); if (r == SS_SUCCESS) { dev_info(DEV, "Began resync as %s (will sync %lu KB [%lu bits set]).\n", drbd_conn_str(ns.conn), (unsigned long) mdev->rs_total << (BM_BLOCK_SHIFT-10), (unsigned long) mdev->rs_total); if (mdev->rs_total == 0) { /* Peer still reachable? Beware of failing before-resync-target handlers! */ ping_peer(mdev); drbd_resync_finished(mdev); } /* ns.conn may already be != mdev->state.conn, * we may have been paused in between, or become paused until * the timer triggers. * No matter, that is handled in resync_timer_fn() */ if (ns.conn == C_SYNC_TARGET) mod_timer(&mdev->resync_timer, jiffies); drbd_md_sync(mdev); } drbd_state_unlock(mdev); } int drbd_worker(struct drbd_thread *thi) { struct drbd_conf *mdev = thi->mdev; struct drbd_work *w = NULL; LIST_HEAD(work_list); int intr = 0, i; sprintf(current->comm, "drbd%d_worker", mdev_to_minor(mdev)); while (get_t_state(thi) == Running) { drbd_thread_current_set_cpu(mdev); if (down_trylock(&mdev->data.work.s)) { mutex_lock(&mdev->data.mutex); if (mdev->data.socket && !mdev->net_conf->no_cork) drbd_tcp_uncork(mdev->data.socket); mutex_unlock(&mdev->data.mutex); intr = down_interruptible(&mdev->data.work.s); mutex_lock(&mdev->data.mutex); if (mdev->data.socket && !mdev->net_conf->no_cork) drbd_tcp_cork(mdev->data.socket); mutex_unlock(&mdev->data.mutex); } if (intr) { D_ASSERT(intr == -EINTR); flush_signals(current); ERR_IF (get_t_state(thi) == Running) continue; break; } if (get_t_state(thi) != Running) break; /* With this break, we have done a down() but not consumed the entry from the list. The cleanup code takes care of this... */ w = NULL; spin_lock_irq(&mdev->data.work.q_lock); ERR_IF(list_empty(&mdev->data.work.q)) { /* something terribly wrong in our logic. * we were able to down() the semaphore, * but the list is empty... doh. * * what is the best thing to do now? * try again from scratch, restarting the receiver, * asender, whatnot? could break even more ugly, * e.g. when we are primary, but no good local data. * * I'll try to get away just starting over this loop. */ spin_unlock_irq(&mdev->data.work.q_lock); continue; } w = list_entry(mdev->data.work.q.next, struct drbd_work, list); list_del_init(&w->list); spin_unlock_irq(&mdev->data.work.q_lock); if (!w->cb(mdev, w, mdev->state.conn < C_CONNECTED)) { /* dev_warn(DEV, "worker: a callback failed! \n"); */ if (mdev->state.conn >= C_CONNECTED) drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE)); } } D_ASSERT(test_bit(DEVICE_DYING, &mdev->flags)); D_ASSERT(test_bit(CONFIG_PENDING, &mdev->flags)); spin_lock_irq(&mdev->data.work.q_lock); i = 0; while (!list_empty(&mdev->data.work.q)) { list_splice_init(&mdev->data.work.q, &work_list); spin_unlock_irq(&mdev->data.work.q_lock); while (!list_empty(&work_list)) { w = list_entry(work_list.next, struct drbd_work, list); list_del_init(&w->list); w->cb(mdev, w, 1); i++; /* dead debugging code */ } spin_lock_irq(&mdev->data.work.q_lock); } sema_init(&mdev->data.work.s, 0); /* DANGEROUS race: if someone did queue his work within the spinlock, * but up() ed outside the spinlock, we could get an up() on the * semaphore without corresponding list entry. * So don't do that. */ spin_unlock_irq(&mdev->data.work.q_lock); D_ASSERT(mdev->state.disk == D_DISKLESS && mdev->state.conn == C_STANDALONE); /* _drbd_set_state only uses stop_nowait. * wait here for the Exiting receiver. */ drbd_thread_stop(&mdev->receiver); drbd_mdev_cleanup(mdev); dev_info(DEV, "worker terminated\n"); clear_bit(DEVICE_DYING, &mdev->flags); clear_bit(CONFIG_PENDING, &mdev->flags); wake_up(&mdev->state_wait); return 0; }