/* 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 "drbd_int.h" #include "drbd_wrappers.h" /* We maintain a trivial check sum in our on disk activity log. * With that we can ensure correct operation even when the storage * device might do a partial (last) sector write while loosing power. */ struct __packed al_transaction { u32 magic; u32 tr_number; struct __packed { u32 pos; u32 extent; } updates[1 + AL_EXTENTS_PT]; u32 xor_sum; }; struct update_odbm_work { struct drbd_work w; unsigned int enr; }; struct update_al_work { struct drbd_work w; struct lc_element *al_ext; struct completion event; unsigned int enr; /* if old_enr != LC_FREE, write corresponding bitmap sector, too */ unsigned int old_enr; }; struct drbd_atodb_wait { atomic_t count; struct completion io_done; struct drbd_conf *mdev; int error; }; int w_al_write_transaction(struct drbd_conf *, struct drbd_work *, int); 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; struct drbd_md_io md_io; int ok; md_io.mdev = mdev; init_completion(&md_io.event); md_io.error = 0; if ((rw & WRITE) && !test_bit(MD_NO_BARRIER, &mdev->flags)) rw |= REQ_HARDBARRIER; rw |= REQ_UNPLUG | REQ_SYNC; retry: bio = bio_alloc(GFP_NOIO, 1); bio->bi_bdev = bdev->md_bdev; bio->bi_sector = sector; ok = (bio_add_page(bio, page, size, 0) == size); if (!ok) goto out; bio->bi_private = &md_io; bio->bi_end_io = drbd_md_io_complete; bio->bi_rw = rw; if (FAULT_ACTIVE(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) bio_endio(bio, -EIO); else submit_bio(rw, bio); wait_for_completion(&md_io.event); ok = bio_flagged(bio, BIO_UPTODATE) && md_io.error == 0; /* check for unsupported barrier op. * would rather check on EOPNOTSUPP, but that is not reliable. * don't try again for ANY return value != 0 */ if (unlikely((bio->bi_rw & REQ_HARDBARRIER) && !ok)) { /* Try again with no barrier */ dev_warn(DEV, "Barriers not supported on meta data device - disabling\n"); set_bit(MD_NO_BARRIER, &mdev->flags); rw &= ~REQ_HARDBARRIER; bio_put(bio); goto retry; } out: bio_put(bio); return ok; } int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev, sector_t sector, int rw) { int logical_block_size, mask, ok; int offset = 0; struct page *iop = mdev->md_io_page; D_ASSERT(mutex_is_locked(&mdev->md_io_mutex)); BUG_ON(!bdev->md_bdev); logical_block_size = bdev_logical_block_size(bdev->md_bdev); if (logical_block_size == 0) logical_block_size = MD_SECTOR_SIZE; /* in case logical_block_size != 512 [ s390 only? ] */ if (logical_block_size != MD_SECTOR_SIZE) { mask = (logical_block_size / MD_SECTOR_SIZE) - 1; D_ASSERT(mask == 1 || mask == 3 || mask == 7); D_ASSERT(logical_block_size == (mask+1) * MD_SECTOR_SIZE); offset = sector & mask; sector = sector & ~mask; iop = mdev->md_io_tmpp; if (rw & WRITE) { /* these are GFP_KERNEL pages, pre-allocated * on device initialization */ void *p = page_address(mdev->md_io_page); void *hp = page_address(mdev->md_io_tmpp); ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector, READ, logical_block_size); if (unlikely(!ok)) { dev_err(DEV, "drbd_md_sync_page_io(,%llus," "READ [logical_block_size!=512]) failed!\n", (unsigned long long)sector); return 0; } memcpy(hp + offset*MD_SECTOR_SIZE, p, MD_SECTOR_SIZE); } } if (sector < drbd_md_first_sector(bdev) || sector > 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"); ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, logical_block_size); if (unlikely(!ok)) { dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed!\n", (unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ"); return 0; } if (logical_block_size != MD_SECTOR_SIZE && !(rw & WRITE)) { void *p = page_address(mdev->md_io_page); void *hp = page_address(mdev->md_io_tmpp); memcpy(p, hp + offset*MD_SECTOR_SIZE, MD_SECTOR_SIZE); } return ok; } static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr) { struct lc_element *al_ext; struct lc_element *tmp; unsigned long al_flags = 0; 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)) { spin_unlock_irq(&mdev->al_lock); return NULL; } } al_ext = lc_get(mdev->act_log, enr); al_flags = mdev->act_log->flags; spin_unlock_irq(&mdev->al_lock); /* if (!al_ext) { if (al_flags & LC_STARVING) dev_warn(DEV, "Have to wait for LRU element (AL too small?)\n"); if (al_flags & LC_DIRTY) dev_warn(DEV, "Ongoing AL update (AL device too slow?)\n"); } */ return al_ext; } void drbd_al_begin_io(struct drbd_conf *mdev, sector_t sector) { unsigned int enr = (sector >> (AL_EXTENT_SHIFT-9)); struct lc_element *al_ext; struct update_al_work al_work; D_ASSERT(atomic_read(&mdev->local_cnt) > 0); wait_event(mdev->al_wait, (al_ext = _al_get(mdev, enr))); if (al_ext->lc_number != enr) { /* 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. */ init_completion(&al_work.event); al_work.al_ext = al_ext; al_work.enr = enr; al_work.old_enr = al_ext->lc_number; al_work.w.cb = w_al_write_transaction; drbd_queue_work_front(&mdev->data.work, &al_work.w); wait_for_completion(&al_work.event); mdev->al_writ_cnt++; spin_lock_irq(&mdev->al_lock); lc_changed(mdev->act_log, al_ext); spin_unlock_irq(&mdev->al_lock); wake_up(&mdev->al_wait); } } void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector) { unsigned int enr = (sector >> (AL_EXTENT_SHIFT-9)); struct lc_element *extent; unsigned long flags; spin_lock_irqsave(&mdev->al_lock, flags); extent = lc_find(mdev->act_log, enr); if (!extent) { spin_unlock_irqrestore(&mdev->al_lock, flags); dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr); return; } if (lc_put(mdev->act_log, extent) == 0) wake_up(&mdev->al_wait); spin_unlock_irqrestore(&mdev->al_lock, flags); } int w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused) { struct update_al_work *aw = container_of(w, struct update_al_work, w); struct lc_element *updated = aw->al_ext; const unsigned int new_enr = aw->enr; const unsigned int evicted = aw->old_enr; struct al_transaction *buffer; sector_t sector; int i, n, mx; unsigned int extent_nr; u32 xor_sum = 0; if (!get_ldev(mdev)) { dev_err(DEV, "get_ldev() failed in w_al_write_transaction\n"); complete(&((struct update_al_work *)w)->event); return 1; } /* do we have to do a bitmap write, first? * TODO reduce maximum latency: * submit both bios, then wait for both, * instead of doing two synchronous sector writes. */ if (mdev->state.conn < C_CONNECTED && evicted != LC_FREE) drbd_bm_write_sect(mdev, evicted/AL_EXT_PER_BM_SECT); mutex_lock(&mdev->md_io_mutex); /* protects md_io_page, al_tr_cycle, ... */ buffer = (struct al_transaction *)page_address(mdev->md_io_page); buffer->magic = __constant_cpu_to_be32(DRBD_MAGIC); buffer->tr_number = cpu_to_be32(mdev->al_tr_number); n = lc_index_of(mdev->act_log, updated); buffer->updates[0].pos = cpu_to_be32(n); buffer->updates[0].extent = cpu_to_be32(new_enr); xor_sum ^= new_enr; mx = min_t(int, AL_EXTENTS_PT, 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->updates[i+1].pos = cpu_to_be32(idx); buffer->updates[i+1].extent = cpu_to_be32(extent_nr); xor_sum ^= extent_nr; } for (; i < AL_EXTENTS_PT; i++) { buffer->updates[i+1].pos = __constant_cpu_to_be32(-1); buffer->updates[i+1].extent = __constant_cpu_to_be32(LC_FREE); xor_sum ^= LC_FREE; } mdev->al_tr_cycle += AL_EXTENTS_PT; if (mdev->al_tr_cycle >= mdev->act_log->nr_elements) mdev->al_tr_cycle = 0; buffer->xor_sum = cpu_to_be32(xor_sum); sector = mdev->ldev->md.md_offset + mdev->ldev->md.al_offset + mdev->al_tr_pos; if (!drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) drbd_chk_io_error(mdev, 1, TRUE); if (++mdev->al_tr_pos > div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT)) mdev->al_tr_pos = 0; D_ASSERT(mdev->al_tr_pos < MD_AL_MAX_SIZE); mdev->al_tr_number++; mutex_unlock(&mdev->md_io_mutex); complete(&((struct update_al_work *)w)->event); put_ldev(mdev); return 1; } /** * drbd_al_read_tr() - Read a single transaction from the on disk activity log * @mdev: DRBD device. * @bdev: Block device to read form. * @b: pointer to an al_transaction. * @index: On disk slot of the transaction to read. * * Returns -1 on IO error, 0 on checksum error and 1 upon success. */ static int drbd_al_read_tr(struct drbd_conf *mdev, struct drbd_backing_dev *bdev, struct al_transaction *b, int index) { sector_t sector; int rv, i; u32 xor_sum = 0; sector = bdev->md.md_offset + bdev->md.al_offset + index; /* Dont process error normally, * as this is done before disk is attached! */ if (!drbd_md_sync_page_io(mdev, bdev, sector, READ)) return -1; rv = (be32_to_cpu(b->magic) == DRBD_MAGIC); for (i = 0; i < AL_EXTENTS_PT + 1; i++) xor_sum ^= be32_to_cpu(b->updates[i].extent); rv &= (xor_sum == be32_to_cpu(b->xor_sum)); return rv; } /** * drbd_al_read_log() - Restores the activity log from its on disk representation. * @mdev: DRBD device. * @bdev: Block device to read form. * * Returns 1 on success, returns 0 when reading the log failed due to IO errors. */ int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev) { struct al_transaction *buffer; int i; int rv; int mx; int active_extents = 0; int transactions = 0; int found_valid = 0; int from = 0; int to = 0; u32 from_tnr = 0; u32 to_tnr = 0; u32 cnr; mx = div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT); /* lock out all other meta data io for now, * and make sure the page is mapped. */ mutex_lock(&mdev->md_io_mutex); buffer = page_address(mdev->md_io_page); /* Find the valid transaction in the log */ for (i = 0; i <= mx; i++) { rv = drbd_al_read_tr(mdev, bdev, buffer, i); if (rv == 0) continue; if (rv == -1) { mutex_unlock(&mdev->md_io_mutex); return 0; } cnr = be32_to_cpu(buffer->tr_number); if (++found_valid == 1) { from = i; to = i; from_tnr = cnr; to_tnr = cnr; continue; } if ((int)cnr - (int)from_tnr < 0) { D_ASSERT(from_tnr - cnr + i - from == mx+1); from = i; from_tnr = cnr; } if ((int)cnr - (int)to_tnr > 0) { D_ASSERT(cnr - to_tnr == i - to); to = i; to_tnr = cnr; } } if (!found_valid) { dev_warn(DEV, "No usable activity log found.\n"); mutex_unlock(&mdev->md_io_mutex); return 1; } /* Read the valid transactions. * dev_info(DEV, "Reading from %d to %d.\n",from,to); */ i = from; while (1) { int j, pos; unsigned int extent_nr; unsigned int trn; rv = drbd_al_read_tr(mdev, bdev, buffer, i); ERR_IF(rv == 0) goto cancel; if (rv == -1) { mutex_unlock(&mdev->md_io_mutex); return 0; } trn = be32_to_cpu(buffer->tr_number); spin_lock_irq(&mdev->al_lock); /* This loop runs backwards because in the cyclic elements there might be an old version of the updated element (in slot 0). So the element in slot 0 can overwrite old versions. */ for (j = AL_EXTENTS_PT; j >= 0; j--) { pos = be32_to_cpu(buffer->updates[j].pos); extent_nr = be32_to_cpu(buffer->updates[j].extent); if (extent_nr == LC_FREE) continue; lc_set(mdev->act_log, extent_nr, pos); active_extents++; } spin_unlock_irq(&mdev->al_lock); transactions++; cancel: if (i == to) break; i++; if (i > mx) i = 0; } mdev->al_tr_number = to_tnr+1; mdev->al_tr_pos = to; if (++mdev->al_tr_pos > div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT)) mdev->al_tr_pos = 0; /* ok, we are done with it */ mutex_unlock(&mdev->md_io_mutex); dev_info(DEV, "Found %d transactions (%d active extents) in activity log.\n", transactions, active_extents); return 1; } static void atodb_endio(struct bio *bio, int error) { struct drbd_atodb_wait *wc = bio->bi_private; struct drbd_conf *mdev = wc->mdev; struct page *page; int uptodate = bio_flagged(bio, BIO_UPTODATE); /* strange behavior of some lower level drivers... * fail the request by clearing the uptodate flag, * but do not return any error?! */ if (!error && !uptodate) error = -EIO; drbd_chk_io_error(mdev, error, TRUE); if (error && wc->error == 0) wc->error = error; if (atomic_dec_and_test(&wc->count)) complete(&wc->io_done); page = bio->bi_io_vec[0].bv_page; put_page(page); bio_put(bio); mdev->bm_writ_cnt++; put_ldev(mdev); } /* sector to word */ #define S2W(s) ((s)<<(BM_EXT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL)) /* activity log to on disk bitmap -- prepare bio unless that sector * is already covered by previously prepared bios */ static int atodb_prepare_unless_covered(struct drbd_conf *mdev, struct bio **bios, unsigned int enr, struct drbd_atodb_wait *wc) __must_hold(local) { struct bio *bio; struct page *page; sector_t on_disk_sector; unsigned int page_offset = PAGE_SIZE; int offset; int i = 0; int err = -ENOMEM; /* We always write aligned, full 4k blocks, * so we can ignore the logical_block_size (for now) */ enr &= ~7U; on_disk_sector = enr + mdev->ldev->md.md_offset + mdev->ldev->md.bm_offset; D_ASSERT(!(on_disk_sector & 7U)); /* Check if that enr is already covered by an already created bio. * Caution, bios[] is not NULL terminated, * but only initialized to all NULL. * For completely scattered activity log, * the last invocation iterates over all bios, * and finds the last NULL entry. */ while ((bio = bios[i])) { if (bio->bi_sector == on_disk_sector) return 0; i++; } /* bios[i] == NULL, the next not yet used slot */ /* GFP_KERNEL, we are not in the write-out path */ bio = bio_alloc(GFP_KERNEL, 1); if (bio == NULL) return -ENOMEM; if (i > 0) { const struct bio_vec *prev_bv = bios[i-1]->bi_io_vec; page_offset = prev_bv->bv_offset + prev_bv->bv_len; page = prev_bv->bv_page; } if (page_offset == PAGE_SIZE) { page = alloc_page(__GFP_HIGHMEM); if (page == NULL) goto out_bio_put; page_offset = 0; } else { get_page(page); } offset = S2W(enr); drbd_bm_get_lel(mdev, offset, min_t(size_t, S2W(8), drbd_bm_words(mdev) - offset), kmap(page) + page_offset); kunmap(page); bio->bi_private = wc; bio->bi_end_io = atodb_endio; bio->bi_bdev = mdev->ldev->md_bdev; bio->bi_sector = on_disk_sector; if (bio_add_page(bio, page, 4096, page_offset) != 4096) goto out_put_page; atomic_inc(&wc->count); /* we already know that we may do this... * get_ldev_if_state(mdev,D_ATTACHING); * just get the extra reference, so that the local_cnt reflects * the number of pending IO requests DRBD at its backing device. */ atomic_inc(&mdev->local_cnt); bios[i] = bio; return 0; out_put_page: err = -EINVAL; put_page(page); out_bio_put: bio_put(bio); return err; } /** * drbd_al_to_on_disk_bm() - * Writes bitmap parts covered by active AL extents * @mdev: DRBD device. * * Called when we detach (unconfigure) local storage, * or when we go from R_PRIMARY to R_SECONDARY role. */ void drbd_al_to_on_disk_bm(struct drbd_conf *mdev) { int i, nr_elements; unsigned int enr; struct bio **bios; struct drbd_atodb_wait wc; ERR_IF (!get_ldev_if_state(mdev, D_ATTACHING)) return; /* sorry, I don't have any act_log etc... */ wait_event(mdev->al_wait, lc_try_lock(mdev->act_log)); nr_elements = mdev->act_log->nr_elements; /* GFP_KERNEL, we are not in anyone's write-out path */ bios = kzalloc(sizeof(struct bio *) * nr_elements, GFP_KERNEL); if (!bios) goto submit_one_by_one; atomic_set(&wc.count, 0); init_completion(&wc.io_done); wc.mdev = mdev; wc.error = 0; for (i = 0; i < nr_elements; i++) { enr = lc_element_by_index(mdev->act_log, i)->lc_number; if (enr == LC_FREE) continue; /* next statement also does atomic_inc wc.count and local_cnt */ if (atodb_prepare_unless_covered(mdev, bios, enr/AL_EXT_PER_BM_SECT, &wc)) goto free_bios_submit_one_by_one; } /* unnecessary optimization? */ lc_unlock(mdev->act_log); wake_up(&mdev->al_wait); /* all prepared, submit them */ for (i = 0; i < nr_elements; i++) { if (bios[i] == NULL) break; if (FAULT_ACTIVE(mdev, DRBD_FAULT_MD_WR)) { bios[i]->bi_rw = WRITE; bio_endio(bios[i], -EIO); } else { submit_bio(WRITE, bios[i]); } } drbd_blk_run_queue(bdev_get_queue(mdev->ldev->md_bdev)); /* always (try to) flush bitmap to stable storage */ drbd_md_flush(mdev); /* In case we did not submit a single IO do not wait for * them to complete. ( Because we would wait forever here. ) * * In case we had IOs and they are already complete, there * is not point in waiting anyways. * Therefore this if () ... */ if (atomic_read(&wc.count)) wait_for_completion(&wc.io_done); put_ldev(mdev); kfree(bios); return; free_bios_submit_one_by_one: /* free everything by calling the endio callback directly. */ for (i = 0; i < nr_elements && bios[i]; i++) bio_endio(bios[i], 0); kfree(bios); submit_one_by_one: dev_warn(DEV, "Using the slow drbd_al_to_on_disk_bm()\n"); for (i = 0; i < mdev->act_log->nr_elements; i++) { enr = lc_element_by_index(mdev->act_log, i)->lc_number; if (enr == LC_FREE) continue; /* Really slow: if we have al-extents 16..19 active, * sector 4 will be written four times! Synchronous! */ drbd_bm_write_sect(mdev, enr/AL_EXT_PER_BM_SECT); } lc_unlock(mdev->act_log); wake_up(&mdev->al_wait); put_ldev(mdev); } /** * drbd_al_apply_to_bm() - Sets the bitmap to diry(1) where covered ba active AL extents * @mdev: DRBD device. */ void drbd_al_apply_to_bm(struct drbd_conf *mdev) { unsigned int enr; unsigned long add = 0; char ppb[10]; int i; wait_event(mdev->al_wait, lc_try_lock(mdev->act_log)); for (i = 0; i < mdev->act_log->nr_elements; i++) { enr = lc_element_by_index(mdev->act_log, i)->lc_number; if (enr == LC_FREE) continue; add += drbd_bm_ALe_set_all(mdev, enr); } lc_unlock(mdev->act_log); wake_up(&mdev->al_wait); dev_info(DEV, "Marked additional %s as out-of-sync based on AL.\n", ppsize(ppb, Bit2KB(add))); } 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_DIRTY, &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_conf *mdev, struct drbd_work *w, int unused) { struct update_odbm_work *udw = container_of(w, struct update_odbm_work, w); 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 1; } drbd_bm_write_sect(mdev, 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_sync_progress(mdev); return 1; } /* 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_err(DEV, "BAD! sector=%llus enr=%u rs_left=%d " "rs_failed=%d count=%d\n", (unsigned long long)sector, ext->lce.lc_number, ext->rs_left, ext->rs_failed, count); dump_stack(); lc_put(mdev->resync, &ext->lce); drbd_force_state(mdev, NS(conn, C_DISCONNECTING)); return; } } 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); set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags); } ext->rs_left = rs_left; ext->rs_failed = success ? 0 : count; lc_changed(mdev->resync, &ext->lce); } 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; drbd_queue_work_front(&mdev->data.work, &udw->w); } else { dev_warn(DEV, "Could not kmalloc an udw\n"); set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags); } } } else { dev_err(DEV, "lc_get() failed! locked=%d/%d flags=%lu\n", mdev->resync_locked, mdev->resync->nr_elements, mdev->resync->flags); } } /* 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 || (size & 0x1ff) != 0 || size > DRBD_MAX_SEGMENT_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; ERR_IF(sector >= nr_sectors) return; ERR_IF(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)) { 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)) { unsigned long tw = drbd_bm_total_weight(mdev); if (mdev->rs_mark_left[mdev->rs_last_mark] != tw && 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] = tw; mdev->rs_last_mark = next; } } 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_SEGMENT_SIZE/BM_BLOCK_SIZE bits. * * called by tl_clear and drbd_send_dblock (==drbd_make_request). * so this can be _any_ process. */ void __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, lbnr, flags; sector_t esector, nr_sectors; unsigned int enr, count; struct lc_element *e; if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_SEGMENT_SIZE) { dev_err(DEV, "sector: %llus, size: %d\n", (unsigned long long)sector, size); return; } if (!get_ldev(mdev)) return; /* no disk, no metadata, no bitmap to set bits in */ nr_sectors = drbd_get_capacity(mdev->this_bdev); esector = sector + (size >> 9) - 1; ERR_IF(sector >= nr_sectors) goto out; ERR_IF(esector >= nr_sectors) esector = (nr_sectors-1); lbnr = BM_SECT_TO_BIT(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); } 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_changed(mdev->resync, &bm_ext->lce); 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_DIRTY); } return bm_ext; } static int _is_in_al(struct drbd_conf *mdev, unsigned int enr) { struct lc_element *al_ext; int rv = 0; spin_lock_irq(&mdev->al_lock); if (unlikely(enr == mdev->act_log->new_number)) rv = 1; else { al_ext = lc_find(mdev->act_log, enr); if (al_ext) { if (al_ext->refcnt) rv = 1; } } spin_unlock_irq(&mdev->al_lock); /* if (unlikely(rv)) { dev_info(DEV, "Delaying sync read until app's write is done\n"); } */ 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; 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)); if (sig) { spin_lock_irq(&mdev->al_lock); if (lc_put(mdev->resync, &bm_ext->lce) == 0) { clear_bit(BME_NO_WRITES, &bm_ext->flags); mdev->resync_locked--; wake_up(&mdev->al_wait); } spin_unlock_irq(&mdev->al_lock); return -EINTR; } } 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_DIRTY); 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_changed(mdev->resync, &bm_ext->lce); 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 (unlikely(al_enr+i == mdev->act_log->new_number)) goto try_again; 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) { clear_bit(BME_LOCKED, &bm_ext->flags); clear_bit(BME_NO_WRITES, &bm_ext->flags); 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); 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 || (size & 0x1ff) != 0 || size > DRBD_MAX_SEGMENT_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; ERR_IF(sector >= nr_sectors) return; ERR_IF(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); }