/* drbd_actlog.c This file is part of DRBD by Philipp Reisner and Lars Ellenberg. Copyright (C) 2003-2008, LINBIT Information Technologies GmbH. Copyright (C) 2003-2008, Philipp Reisner . Copyright (C) 2003-2008, 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 "drbd_int.h" #include "drbd_wrappers.h" enum al_transaction_types { AL_TR_UPDATE = 0, AL_TR_INITIALIZED = 0xffff }; /* all fields on disc in big endian */ struct __packed al_transaction_on_disk { /* don't we all like magic */ __be32 magic; /* to identify the most recent transaction block * in the on disk ring buffer */ __be32 tr_number; /* checksum on the full 4k block, with this field set to 0. */ __be32 crc32c; /* type of transaction, special transaction types like: * purge-all, set-all-idle, set-all-active, ... to-be-defined * see also enum al_transaction_types */ __be16 transaction_type; /* we currently allow only a few thousand extents, * so 16bit will be enough for the slot number. */ /* how many updates in this transaction */ __be16 n_updates; /* maximum slot number, "al-extents" in drbd.conf speak. * Having this in each transaction should make reconfiguration * of that parameter easier. */ __be16 context_size; /* slot number the context starts with */ __be16 context_start_slot_nr; /* Some reserved bytes. Expected usage is a 64bit counter of * sectors-written since device creation, and other data generation tag * supporting usage */ __be32 __reserved[4]; /* --- 36 byte used --- */ /* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes * in one transaction, then use the remaining byte in the 4k block for * context information. "Flexible" number of updates per transaction * does not help, as we have to account for the case when all update * slots are used anyways, so it would only complicate code without * additional benefit. */ __be16 update_slot_nr[AL_UPDATES_PER_TRANSACTION]; /* but the extent number is 32bit, which at an extent size of 4 MiB * allows to cover device sizes of up to 2**54 Byte (16 PiB) */ __be32 update_extent_nr[AL_UPDATES_PER_TRANSACTION]; /* --- 420 bytes used (36 + 64*6) --- */ /* 4096 - 420 = 3676 = 919 * 4 */ __be32 context[AL_CONTEXT_PER_TRANSACTION]; }; struct update_odbm_work { struct drbd_work w; unsigned int enr; }; struct update_al_work { struct drbd_work w; struct completion event; int err; }; static int al_write_transaction(struct drbd_conf *mdev); void *drbd_md_get_buffer(struct drbd_conf *mdev) { int r; wait_event(mdev->misc_wait, (r = atomic_cmpxchg(&mdev->md_io_in_use, 0, 1)) == 0 || mdev->state.disk <= D_FAILED); return r ? NULL : page_address(mdev->md_io_page); } void drbd_md_put_buffer(struct drbd_conf *mdev) { if (atomic_dec_and_test(&mdev->md_io_in_use)) wake_up(&mdev->misc_wait); } static bool md_io_allowed(struct drbd_conf *mdev) { enum drbd_disk_state ds = mdev->state.disk; return ds >= D_NEGOTIATING || ds == D_ATTACHING; } void wait_until_done_or_disk_failure(struct drbd_conf *mdev, struct drbd_backing_dev *bdev, unsigned int *done) { long dt; rcu_read_lock(); dt = rcu_dereference(bdev->disk_conf)->disk_timeout; rcu_read_unlock(); dt = dt * HZ / 10; if (dt == 0) dt = MAX_SCHEDULE_TIMEOUT; dt = wait_event_timeout(mdev->misc_wait, *done || !md_io_allowed(mdev), dt); if (dt == 0) dev_err(DEV, "meta-data IO operation timed out\n"); } static int _drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev, struct page *page, sector_t sector, int rw, int size) { struct bio *bio; int err; mdev->md_io.done = 0; mdev->md_io.error = -ENODEV; if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags)) rw |= REQ_FUA | REQ_FLUSH; rw |= REQ_SYNC; bio = bio_alloc_drbd(GFP_NOIO); bio->bi_bdev = bdev->md_bdev; bio->bi_sector = sector; err = -EIO; if (bio_add_page(bio, page, size, 0) != size) goto out; bio->bi_private = &mdev->md_io; bio->bi_end_io = drbd_md_io_complete; bio->bi_rw = rw; if (!get_ldev_if_state(mdev, D_ATTACHING)) { /* Corresponding put_ldev in drbd_md_io_complete() */ dev_err(DEV, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n"); err = -ENODEV; goto out; } bio_get(bio); /* one bio_put() is in the completion handler */ atomic_inc(&mdev->md_io_in_use); /* drbd_md_put_buffer() is in the completion handler */ if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) bio_endio(bio, -EIO); else submit_bio(rw, bio); wait_until_done_or_disk_failure(mdev, bdev, &mdev->md_io.done); if (bio_flagged(bio, BIO_UPTODATE)) err = mdev->md_io.error; out: bio_put(bio); return err; } int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev, sector_t sector, int rw) { int err; struct page *iop = mdev->md_io_page; D_ASSERT(atomic_read(&mdev->md_io_in_use) == 1); BUG_ON(!bdev->md_bdev); dev_dbg(DEV, "meta_data io: %s [%d]:%s(,%llus,%s)\n", current->comm, current->pid, __func__, (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ"); if (sector < drbd_md_first_sector(bdev) || sector + 7 > drbd_md_last_sector(bdev)) dev_alert(DEV, "%s [%d]:%s(,%llus,%s) out of range md access!\n", current->comm, current->pid, __func__, (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ"); err = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, MD_BLOCK_SIZE); if (err) { dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n", (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ", err); } return err; } static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr) { struct lc_element *al_ext; struct lc_element *tmp; int wake; spin_lock_irq(&mdev->al_lock); tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT); if (unlikely(tmp != NULL)) { struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce); if (test_bit(BME_NO_WRITES, &bm_ext->flags)) { wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags); spin_unlock_irq(&mdev->al_lock); if (wake) wake_up(&mdev->al_wait); return NULL; } } al_ext = lc_get(mdev->act_log, enr); spin_unlock_irq(&mdev->al_lock); return al_ext; } void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i) { /* for bios crossing activity log extent boundaries, * we may need to activate two extents in one go */ unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); unsigned enr; bool locked = false; D_ASSERT(first <= last); D_ASSERT(atomic_read(&mdev->local_cnt) > 0); for (enr = first; enr <= last; enr++) wait_event(mdev->al_wait, _al_get(mdev, enr) != NULL); /* Serialize multiple transactions. * This uses test_and_set_bit, memory barrier is implicit. */ wait_event(mdev->al_wait, mdev->act_log->pending_changes == 0 || (locked = lc_try_lock_for_transaction(mdev->act_log))); if (locked) { /* drbd_al_write_transaction(mdev,al_ext,enr); * recurses into generic_make_request(), which * disallows recursion, bios being serialized on the * current->bio_tail list now. * we have to delegate updates to the activity log * to the worker thread. */ /* Double check: it may have been committed by someone else, * while we have been waiting for the lock. */ if (mdev->act_log->pending_changes) { bool write_al_updates; rcu_read_lock(); write_al_updates = rcu_dereference(mdev->ldev->disk_conf)->al_updates; rcu_read_unlock(); if (write_al_updates) { al_write_transaction(mdev); mdev->al_writ_cnt++; } spin_lock_irq(&mdev->al_lock); /* FIXME if (err) we need an "lc_cancel" here; */ lc_committed(mdev->act_log); spin_unlock_irq(&mdev->al_lock); } lc_unlock(mdev->act_log); wake_up(&mdev->al_wait); } } void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i) { /* for bios crossing activity log extent boundaries, * we may need to activate two extents in one go */ unsigned first = i->sector >> (AL_EXTENT_SHIFT-9); unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9); unsigned enr; struct lc_element *extent; unsigned long flags; D_ASSERT(first <= last); spin_lock_irqsave(&mdev->al_lock, flags); for (enr = first; enr <= last; enr++) { extent = lc_find(mdev->act_log, enr); if (!extent) { dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr); continue; } lc_put(mdev->act_log, extent); } spin_unlock_irqrestore(&mdev->al_lock, flags); wake_up(&mdev->al_wait); } #if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT) /* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT * are still coupled, or assume too much about their relation. * Code below will not work if this is violated. * Will be cleaned up with some followup patch. */ # error FIXME #endif static unsigned int al_extent_to_bm_page(unsigned int al_enr) { return al_enr >> /* bit to page */ ((PAGE_SHIFT + 3) - /* al extent number to bit */ (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)); } static unsigned int rs_extent_to_bm_page(unsigned int rs_enr) { return rs_enr >> /* bit to page */ ((PAGE_SHIFT + 3) - /* resync extent number to bit */ (BM_EXT_SHIFT - BM_BLOCK_SHIFT)); } static int _al_write_transaction(struct drbd_conf *mdev) { struct al_transaction_on_disk *buffer; struct lc_element *e; sector_t sector; int i, mx; unsigned extent_nr; unsigned crc = 0; int err = 0; if (!get_ldev(mdev)) { dev_err(DEV, "disk is %s, cannot start al transaction\n", drbd_disk_str(mdev->state.disk)); return -EIO; } /* The bitmap write may have failed, causing a state change. */ if (mdev->state.disk < D_INCONSISTENT) { dev_err(DEV, "disk is %s, cannot write al transaction\n", drbd_disk_str(mdev->state.disk)); put_ldev(mdev); return -EIO; } buffer = drbd_md_get_buffer(mdev); /* protects md_io_buffer, al_tr_cycle, ... */ if (!buffer) { dev_err(DEV, "disk failed while waiting for md_io buffer\n"); put_ldev(mdev); return -ENODEV; } memset(buffer, 0, sizeof(*buffer)); buffer->magic = cpu_to_be32(DRBD_AL_MAGIC); buffer->tr_number = cpu_to_be32(mdev->al_tr_number); i = 0; /* Even though no one can start to change this list * once we set the LC_LOCKED -- from drbd_al_begin_io(), * lc_try_lock_for_transaction() --, someone may still * be in the process of changing it. */ spin_lock_irq(&mdev->al_lock); list_for_each_entry(e, &mdev->act_log->to_be_changed, list) { if (i == AL_UPDATES_PER_TRANSACTION) { i++; break; } buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index); buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number); if (e->lc_number != LC_FREE) drbd_bm_mark_for_writeout(mdev, al_extent_to_bm_page(e->lc_number)); i++; } spin_unlock_irq(&mdev->al_lock); BUG_ON(i > AL_UPDATES_PER_TRANSACTION); buffer->n_updates = cpu_to_be16(i); for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) { buffer->update_slot_nr[i] = cpu_to_be16(-1); buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE); } buffer->context_size = cpu_to_be16(mdev->act_log->nr_elements); buffer->context_start_slot_nr = cpu_to_be16(mdev->al_tr_cycle); mx = min_t(int, AL_CONTEXT_PER_TRANSACTION, mdev->act_log->nr_elements - mdev->al_tr_cycle); for (i = 0; i < mx; i++) { unsigned idx = mdev->al_tr_cycle + i; extent_nr = lc_element_by_index(mdev->act_log, idx)->lc_number; buffer->context[i] = cpu_to_be32(extent_nr); } for (; i < AL_CONTEXT_PER_TRANSACTION; i++) buffer->context[i] = cpu_to_be32(LC_FREE); mdev->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION; if (mdev->al_tr_cycle >= mdev->act_log->nr_elements) mdev->al_tr_cycle = 0; sector = mdev->ldev->md.md_offset + mdev->ldev->md.al_offset + mdev->al_tr_pos * (MD_BLOCK_SIZE>>9); crc = crc32c(0, buffer, 4096); buffer->crc32c = cpu_to_be32(crc); if (drbd_bm_write_hinted(mdev)) err = -EIO; /* drbd_chk_io_error done already */ else if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) { err = -EIO; drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR); } else { /* advance ringbuffer position and transaction counter */ mdev->al_tr_pos = (mdev->al_tr_pos + 1) % (MD_AL_SECTORS*512/MD_BLOCK_SIZE); mdev->al_tr_number++; } drbd_md_put_buffer(mdev); put_ldev(mdev); return err; } static int w_al_write_transaction(struct drbd_work *w, int unused) { struct update_al_work *aw = container_of(w, struct update_al_work, w); struct drbd_conf *mdev = w->mdev; int err; err = _al_write_transaction(mdev); aw->err = err; complete(&aw->event); return err != -EIO ? err : 0; } /* Calls from worker context (see w_restart_disk_io()) need to write the transaction directly. Others came through generic_make_request(), those need to delegate it to the worker. */ static int al_write_transaction(struct drbd_conf *mdev) { struct update_al_work al_work; if (current == mdev->tconn->worker.task) return _al_write_transaction(mdev); init_completion(&al_work.event); al_work.w.cb = w_al_write_transaction; al_work.w.mdev = mdev; drbd_queue_work_front(&mdev->tconn->sender_work, &al_work.w); wait_for_completion(&al_work.event); return al_work.err; } static int _try_lc_del(struct drbd_conf *mdev, struct lc_element *al_ext) { int rv; spin_lock_irq(&mdev->al_lock); rv = (al_ext->refcnt == 0); if (likely(rv)) lc_del(mdev->act_log, al_ext); spin_unlock_irq(&mdev->al_lock); return rv; } /** * drbd_al_shrink() - Removes all active extents form the activity log * @mdev: DRBD device. * * Removes all active extents form the activity log, waiting until * the reference count of each entry dropped to 0 first, of course. * * You need to lock mdev->act_log with lc_try_lock() / lc_unlock() */ void drbd_al_shrink(struct drbd_conf *mdev) { struct lc_element *al_ext; int i; D_ASSERT(test_bit(__LC_LOCKED, &mdev->act_log->flags)); for (i = 0; i < mdev->act_log->nr_elements; i++) { al_ext = lc_element_by_index(mdev->act_log, i); if (al_ext->lc_number == LC_FREE) continue; wait_event(mdev->al_wait, _try_lc_del(mdev, al_ext)); } wake_up(&mdev->al_wait); } static int w_update_odbm(struct drbd_work *w, int unused) { struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w); struct drbd_conf *mdev = w->mdev; struct sib_info sib = { .sib_reason = SIB_SYNC_PROGRESS, }; if (!get_ldev(mdev)) { if (__ratelimit(&drbd_ratelimit_state)) dev_warn(DEV, "Can not update on disk bitmap, local IO disabled.\n"); kfree(udw); return 0; } drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr)); put_ldev(mdev); kfree(udw); if (drbd_bm_total_weight(mdev) <= mdev->rs_failed) { switch (mdev->state.conn) { case C_SYNC_SOURCE: case C_SYNC_TARGET: case C_PAUSED_SYNC_S: case C_PAUSED_SYNC_T: drbd_resync_finished(mdev); default: /* nothing to do */ break; } } drbd_bcast_event(mdev, &sib); return 0; } /* ATTENTION. The AL's extents are 4MB each, while the extents in the * resync LRU-cache are 16MB each. * The caller of this function has to hold an get_ldev() reference. * * TODO will be obsoleted once we have a caching lru of the on disk bitmap */ static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector, int count, int success) { struct lc_element *e; struct update_odbm_work *udw; unsigned int enr; D_ASSERT(atomic_read(&mdev->local_cnt)); /* I simply assume that a sector/size pair never crosses * a 16 MB extent border. (Currently this is true...) */ enr = BM_SECT_TO_EXT(sector); e = lc_get(mdev->resync, enr); if (e) { struct bm_extent *ext = lc_entry(e, struct bm_extent, lce); if (ext->lce.lc_number == enr) { if (success) ext->rs_left -= count; else ext->rs_failed += count; if (ext->rs_left < ext->rs_failed) { dev_warn(DEV, "BAD! sector=%llus enr=%u rs_left=%d " "rs_failed=%d count=%d cstate=%s\n", (unsigned long long)sector, ext->lce.lc_number, ext->rs_left, ext->rs_failed, count, drbd_conn_str(mdev->state.conn)); /* We don't expect to be able to clear more bits * than have been set when we originally counted * the set bits to cache that value in ext->rs_left. * Whatever the reason (disconnect during resync, * delayed local completion of an application write), * try to fix it up by recounting here. */ ext->rs_left = drbd_bm_e_weight(mdev, enr); } } else { /* Normally this element should be in the cache, * since drbd_rs_begin_io() pulled it already in. * * But maybe an application write finished, and we set * something outside the resync lru_cache in sync. */ int rs_left = drbd_bm_e_weight(mdev, enr); if (ext->flags != 0) { dev_warn(DEV, "changing resync lce: %d[%u;%02lx]" " -> %d[%u;00]\n", ext->lce.lc_number, ext->rs_left, ext->flags, enr, rs_left); ext->flags = 0; } if (ext->rs_failed) { dev_warn(DEV, "Kicking resync_lru element enr=%u " "out with rs_failed=%d\n", ext->lce.lc_number, ext->rs_failed); } ext->rs_left = rs_left; ext->rs_failed = success ? 0 : count; /* we don't keep a persistent log of the resync lru, * we can commit any change right away. */ lc_committed(mdev->resync); } lc_put(mdev->resync, &ext->lce); /* no race, we are within the al_lock! */ if (ext->rs_left == ext->rs_failed) { ext->rs_failed = 0; udw = kmalloc(sizeof(*udw), GFP_ATOMIC); if (udw) { udw->enr = ext->lce.lc_number; udw->w.cb = w_update_odbm; udw->w.mdev = mdev; drbd_queue_work_front(&mdev->tconn->sender_work, &udw->w); } else { dev_warn(DEV, "Could not kmalloc an udw\n"); } } } else { dev_err(DEV, "lc_get() failed! locked=%d/%d flags=%lu\n", mdev->resync_locked, mdev->resync->nr_elements, mdev->resync->flags); } } void drbd_advance_rs_marks(struct drbd_conf *mdev, unsigned long still_to_go) { unsigned long now = jiffies; unsigned long last = mdev->rs_mark_time[mdev->rs_last_mark]; int next = (mdev->rs_last_mark + 1) % DRBD_SYNC_MARKS; if (time_after_eq(now, last + DRBD_SYNC_MARK_STEP)) { if (mdev->rs_mark_left[mdev->rs_last_mark] != still_to_go && mdev->state.conn != C_PAUSED_SYNC_T && mdev->state.conn != C_PAUSED_SYNC_S) { mdev->rs_mark_time[next] = now; mdev->rs_mark_left[next] = still_to_go; mdev->rs_last_mark = next; } } } /* clear the bit corresponding to the piece of storage in question: * size byte of data starting from sector. Only clear a bits of the affected * one ore more _aligned_ BM_BLOCK_SIZE blocks. * * called by worker on C_SYNC_TARGET and receiver on SyncSource. * */ void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size, const char *file, const unsigned int line) { /* Is called from worker and receiver context _only_ */ unsigned long sbnr, ebnr, lbnr; unsigned long count = 0; sector_t esector, nr_sectors; int wake_up = 0; unsigned long flags; if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) { dev_err(DEV, "drbd_set_in_sync: sector=%llus size=%d nonsense!\n", (unsigned long long)sector, size); return; } nr_sectors = drbd_get_capacity(mdev->this_bdev); esector = sector + (size >> 9) - 1; if (!expect(sector < nr_sectors)) return; if (!expect(esector < nr_sectors)) esector = nr_sectors - 1; lbnr = BM_SECT_TO_BIT(nr_sectors-1); /* we clear it (in sync). * round up start sector, round down end sector. we make sure we only * clear full, aligned, BM_BLOCK_SIZE (4K) blocks */ if (unlikely(esector < BM_SECT_PER_BIT-1)) return; if (unlikely(esector == (nr_sectors-1))) ebnr = lbnr; else ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1)); sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1); if (sbnr > ebnr) return; /* * ok, (capacity & 7) != 0 sometimes, but who cares... * we count rs_{total,left} in bits, not sectors. */ count = drbd_bm_clear_bits(mdev, sbnr, ebnr); if (count && get_ldev(mdev)) { drbd_advance_rs_marks(mdev, drbd_bm_total_weight(mdev)); spin_lock_irqsave(&mdev->al_lock, flags); drbd_try_clear_on_disk_bm(mdev, sector, count, true); spin_unlock_irqrestore(&mdev->al_lock, flags); /* just wake_up unconditional now, various lc_chaged(), * lc_put() in drbd_try_clear_on_disk_bm(). */ wake_up = 1; put_ldev(mdev); } if (wake_up) wake_up(&mdev->al_wait); } /* * this is intended to set one request worth of data out of sync. * affects at least 1 bit, * and at most 1+DRBD_MAX_BIO_SIZE/BM_BLOCK_SIZE bits. * * called by tl_clear and drbd_send_dblock (==drbd_make_request). * so this can be _any_ process. */ int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size, const char *file, const unsigned int line) { unsigned long sbnr, ebnr, flags; sector_t esector, nr_sectors; unsigned int enr, count = 0; struct lc_element *e; /* this should be an empty REQ_FLUSH */ if (size == 0) return 0; if (size < 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) { dev_err(DEV, "sector: %llus, size: %d\n", (unsigned long long)sector, size); return 0; } if (!get_ldev(mdev)) return 0; /* no disk, no metadata, no bitmap to set bits in */ nr_sectors = drbd_get_capacity(mdev->this_bdev); esector = sector + (size >> 9) - 1; if (!expect(sector < nr_sectors)) goto out; if (!expect(esector < nr_sectors)) esector = nr_sectors - 1; /* we set it out of sync, * we do not need to round anything here */ sbnr = BM_SECT_TO_BIT(sector); ebnr = BM_SECT_TO_BIT(esector); /* ok, (capacity & 7) != 0 sometimes, but who cares... * we count rs_{total,left} in bits, not sectors. */ spin_lock_irqsave(&mdev->al_lock, flags); count = drbd_bm_set_bits(mdev, sbnr, ebnr); enr = BM_SECT_TO_EXT(sector); e = lc_find(mdev->resync, enr); if (e) lc_entry(e, struct bm_extent, lce)->rs_left += count; spin_unlock_irqrestore(&mdev->al_lock, flags); out: put_ldev(mdev); return count; } static struct bm_extent *_bme_get(struct drbd_conf *mdev, unsigned int enr) { struct lc_element *e; struct bm_extent *bm_ext; int wakeup = 0; unsigned long rs_flags; spin_lock_irq(&mdev->al_lock); if (mdev->resync_locked > mdev->resync->nr_elements/2) { spin_unlock_irq(&mdev->al_lock); return NULL; } e = lc_get(mdev->resync, enr); bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; if (bm_ext) { if (bm_ext->lce.lc_number != enr) { bm_ext->rs_left = drbd_bm_e_weight(mdev, enr); bm_ext->rs_failed = 0; lc_committed(mdev->resync); wakeup = 1; } if (bm_ext->lce.refcnt == 1) mdev->resync_locked++; set_bit(BME_NO_WRITES, &bm_ext->flags); } rs_flags = mdev->resync->flags; spin_unlock_irq(&mdev->al_lock); if (wakeup) wake_up(&mdev->al_wait); if (!bm_ext) { if (rs_flags & LC_STARVING) dev_warn(DEV, "Have to wait for element" " (resync LRU too small?)\n"); BUG_ON(rs_flags & LC_LOCKED); } return bm_ext; } static int _is_in_al(struct drbd_conf *mdev, unsigned int enr) { int rv; spin_lock_irq(&mdev->al_lock); rv = lc_is_used(mdev->act_log, enr); spin_unlock_irq(&mdev->al_lock); return rv; } /** * drbd_rs_begin_io() - Gets an extent in the resync LRU cache and sets it to BME_LOCKED * @mdev: DRBD device. * @sector: The sector number. * * This functions sleeps on al_wait. Returns 0 on success, -EINTR if interrupted. */ int drbd_rs_begin_io(struct drbd_conf *mdev, sector_t sector) { unsigned int enr = BM_SECT_TO_EXT(sector); struct bm_extent *bm_ext; int i, sig; int sa = 200; /* Step aside 200 times, then grab the extent and let app-IO wait. 200 times -> 20 seconds. */ retry: sig = wait_event_interruptible(mdev->al_wait, (bm_ext = _bme_get(mdev, enr))); if (sig) return -EINTR; if (test_bit(BME_LOCKED, &bm_ext->flags)) return 0; for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { sig = wait_event_interruptible(mdev->al_wait, !_is_in_al(mdev, enr * AL_EXT_PER_BM_SECT + i) || test_bit(BME_PRIORITY, &bm_ext->flags)); if (sig || (test_bit(BME_PRIORITY, &bm_ext->flags) && sa)) { spin_lock_irq(&mdev->al_lock); if (lc_put(mdev->resync, &bm_ext->lce) == 0) { bm_ext->flags = 0; /* clears BME_NO_WRITES and eventually BME_PRIORITY */ mdev->resync_locked--; wake_up(&mdev->al_wait); } spin_unlock_irq(&mdev->al_lock); if (sig) return -EINTR; if (schedule_timeout_interruptible(HZ/10)) return -EINTR; if (sa && --sa == 0) dev_warn(DEV,"drbd_rs_begin_io() stepped aside for 20sec." "Resync stalled?\n"); goto retry; } } set_bit(BME_LOCKED, &bm_ext->flags); return 0; } /** * drbd_try_rs_begin_io() - Gets an extent in the resync LRU cache, does not sleep * @mdev: DRBD device. * @sector: The sector number. * * Gets an extent in the resync LRU cache, sets it to BME_NO_WRITES, then * tries to set it to BME_LOCKED. Returns 0 upon success, and -EAGAIN * if there is still application IO going on in this area. */ int drbd_try_rs_begin_io(struct drbd_conf *mdev, sector_t sector) { unsigned int enr = BM_SECT_TO_EXT(sector); const unsigned int al_enr = enr*AL_EXT_PER_BM_SECT; struct lc_element *e; struct bm_extent *bm_ext; int i; spin_lock_irq(&mdev->al_lock); if (mdev->resync_wenr != LC_FREE && mdev->resync_wenr != enr) { /* in case you have very heavy scattered io, it may * stall the syncer undefined if we give up the ref count * when we try again and requeue. * * if we don't give up the refcount, but the next time * we are scheduled this extent has been "synced" by new * application writes, we'd miss the lc_put on the * extent we keep the refcount on. * so we remembered which extent we had to try again, and * if the next requested one is something else, we do * the lc_put here... * we also have to wake_up */ e = lc_find(mdev->resync, mdev->resync_wenr); bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; if (bm_ext) { D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags)); D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags)); clear_bit(BME_NO_WRITES, &bm_ext->flags); mdev->resync_wenr = LC_FREE; if (lc_put(mdev->resync, &bm_ext->lce) == 0) mdev->resync_locked--; wake_up(&mdev->al_wait); } else { dev_alert(DEV, "LOGIC BUG\n"); } } /* TRY. */ e = lc_try_get(mdev->resync, enr); bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; if (bm_ext) { if (test_bit(BME_LOCKED, &bm_ext->flags)) goto proceed; if (!test_and_set_bit(BME_NO_WRITES, &bm_ext->flags)) { mdev->resync_locked++; } else { /* we did set the BME_NO_WRITES, * but then could not set BME_LOCKED, * so we tried again. * drop the extra reference. */ bm_ext->lce.refcnt--; D_ASSERT(bm_ext->lce.refcnt > 0); } goto check_al; } else { /* do we rather want to try later? */ if (mdev->resync_locked > mdev->resync->nr_elements-3) goto try_again; /* Do or do not. There is no try. -- Yoda */ e = lc_get(mdev->resync, enr); bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; if (!bm_ext) { const unsigned long rs_flags = mdev->resync->flags; if (rs_flags & LC_STARVING) dev_warn(DEV, "Have to wait for element" " (resync LRU too small?)\n"); BUG_ON(rs_flags & LC_LOCKED); goto try_again; } if (bm_ext->lce.lc_number != enr) { bm_ext->rs_left = drbd_bm_e_weight(mdev, enr); bm_ext->rs_failed = 0; lc_committed(mdev->resync); wake_up(&mdev->al_wait); D_ASSERT(test_bit(BME_LOCKED, &bm_ext->flags) == 0); } set_bit(BME_NO_WRITES, &bm_ext->flags); D_ASSERT(bm_ext->lce.refcnt == 1); mdev->resync_locked++; goto check_al; } check_al: for (i = 0; i < AL_EXT_PER_BM_SECT; i++) { if (lc_is_used(mdev->act_log, al_enr+i)) goto try_again; } set_bit(BME_LOCKED, &bm_ext->flags); proceed: mdev->resync_wenr = LC_FREE; spin_unlock_irq(&mdev->al_lock); return 0; try_again: if (bm_ext) mdev->resync_wenr = enr; spin_unlock_irq(&mdev->al_lock); return -EAGAIN; } void drbd_rs_complete_io(struct drbd_conf *mdev, sector_t sector) { unsigned int enr = BM_SECT_TO_EXT(sector); struct lc_element *e; struct bm_extent *bm_ext; unsigned long flags; spin_lock_irqsave(&mdev->al_lock, flags); e = lc_find(mdev->resync, enr); bm_ext = e ? lc_entry(e, struct bm_extent, lce) : NULL; if (!bm_ext) { spin_unlock_irqrestore(&mdev->al_lock, flags); if (__ratelimit(&drbd_ratelimit_state)) dev_err(DEV, "drbd_rs_complete_io() called, but extent not found\n"); return; } if (bm_ext->lce.refcnt == 0) { spin_unlock_irqrestore(&mdev->al_lock, flags); dev_err(DEV, "drbd_rs_complete_io(,%llu [=%u]) called, " "but refcnt is 0!?\n", (unsigned long long)sector, enr); return; } if (lc_put(mdev->resync, &bm_ext->lce) == 0) { bm_ext->flags = 0; /* clear BME_LOCKED, BME_NO_WRITES and BME_PRIORITY */ mdev->resync_locked--; wake_up(&mdev->al_wait); } spin_unlock_irqrestore(&mdev->al_lock, flags); } /** * drbd_rs_cancel_all() - Removes all extents from the resync LRU (even BME_LOCKED) * @mdev: DRBD device. */ void drbd_rs_cancel_all(struct drbd_conf *mdev) { spin_lock_irq(&mdev->al_lock); if (get_ldev_if_state(mdev, D_FAILED)) { /* Makes sure ->resync is there. */ lc_reset(mdev->resync); put_ldev(mdev); } mdev->resync_locked = 0; mdev->resync_wenr = LC_FREE; spin_unlock_irq(&mdev->al_lock); wake_up(&mdev->al_wait); } /** * drbd_rs_del_all() - Gracefully remove all extents from the resync LRU * @mdev: DRBD device. * * Returns 0 upon success, -EAGAIN if at least one reference count was * not zero. */ int drbd_rs_del_all(struct drbd_conf *mdev) { struct lc_element *e; struct bm_extent *bm_ext; int i; spin_lock_irq(&mdev->al_lock); if (get_ldev_if_state(mdev, D_FAILED)) { /* ok, ->resync is there. */ for (i = 0; i < mdev->resync->nr_elements; i++) { e = lc_element_by_index(mdev->resync, i); bm_ext = lc_entry(e, struct bm_extent, lce); if (bm_ext->lce.lc_number == LC_FREE) continue; if (bm_ext->lce.lc_number == mdev->resync_wenr) { dev_info(DEV, "dropping %u in drbd_rs_del_all, apparently" " got 'synced' by application io\n", mdev->resync_wenr); D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags)); D_ASSERT(test_bit(BME_NO_WRITES, &bm_ext->flags)); clear_bit(BME_NO_WRITES, &bm_ext->flags); mdev->resync_wenr = LC_FREE; lc_put(mdev->resync, &bm_ext->lce); } if (bm_ext->lce.refcnt != 0) { dev_info(DEV, "Retrying drbd_rs_del_all() later. " "refcnt=%d\n", bm_ext->lce.refcnt); put_ldev(mdev); spin_unlock_irq(&mdev->al_lock); return -EAGAIN; } D_ASSERT(!test_bit(BME_LOCKED, &bm_ext->flags)); D_ASSERT(!test_bit(BME_NO_WRITES, &bm_ext->flags)); lc_del(mdev->resync, &bm_ext->lce); } D_ASSERT(mdev->resync->used == 0); put_ldev(mdev); } spin_unlock_irq(&mdev->al_lock); wake_up(&mdev->al_wait); return 0; } /** * drbd_rs_failed_io() - Record information on a failure to resync the specified blocks * @mdev: DRBD device. * @sector: The sector number. * @size: Size of failed IO operation, in byte. */ void drbd_rs_failed_io(struct drbd_conf *mdev, sector_t sector, int size) { /* Is called from worker and receiver context _only_ */ unsigned long sbnr, ebnr, lbnr; unsigned long count; sector_t esector, nr_sectors; int wake_up = 0; if (size <= 0 || !IS_ALIGNED(size, 512) || size > DRBD_MAX_BIO_SIZE) { dev_err(DEV, "drbd_rs_failed_io: sector=%llus size=%d nonsense!\n", (unsigned long long)sector, size); return; } nr_sectors = drbd_get_capacity(mdev->this_bdev); esector = sector + (size >> 9) - 1; if (!expect(sector < nr_sectors)) return; if (!expect(esector < nr_sectors)) esector = nr_sectors - 1; lbnr = BM_SECT_TO_BIT(nr_sectors-1); /* * round up start sector, round down end sector. we make sure we only * handle full, aligned, BM_BLOCK_SIZE (4K) blocks */ if (unlikely(esector < BM_SECT_PER_BIT-1)) return; if (unlikely(esector == (nr_sectors-1))) ebnr = lbnr; else ebnr = BM_SECT_TO_BIT(esector - (BM_SECT_PER_BIT-1)); sbnr = BM_SECT_TO_BIT(sector + BM_SECT_PER_BIT-1); if (sbnr > ebnr) return; /* * ok, (capacity & 7) != 0 sometimes, but who cares... * we count rs_{total,left} in bits, not sectors. */ spin_lock_irq(&mdev->al_lock); count = drbd_bm_count_bits(mdev, sbnr, ebnr); if (count) { mdev->rs_failed += count; if (get_ldev(mdev)) { drbd_try_clear_on_disk_bm(mdev, sector, count, false); put_ldev(mdev); } /* just wake_up unconditional now, various lc_chaged(), * lc_put() in drbd_try_clear_on_disk_bm(). */ wake_up = 1; } spin_unlock_irq(&mdev->al_lock); if (wake_up) wake_up(&mdev->al_wait); }