From: Lars Ellenberg Date: Wed, 15 Dec 2010 07:59:11 +0000 (+0100) Subject: drbd: bitmap keep track of changes vs on-disk bitmap X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=19f843aa08e2d8f87a09b4c2edc43b00638423a8;p=deliverable%2Flinux.git drbd: bitmap keep track of changes vs on-disk bitmap When we set or clear bits in a bitmap page, also set a flag in the page->private pointer. This allows us to skip writes of unchanged pages. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c index e3f0f4d31d75..090fc2ce0df4 100644 --- a/drivers/block/drbd/drbd_actlog.c +++ b/drivers/block/drbd/drbd_actlog.c @@ -262,6 +262,33 @@ void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector) spin_unlock_irqrestore(&mdev->al_lock, flags); } +#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) - + /* al extent number to bit */ + (BM_EXT_SHIFT - BM_BLOCK_SHIFT)); +} + int w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused) { @@ -289,7 +316,7 @@ w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused) * For now, we must not write the transaction, * if we cannot write out the bitmap of the evicted extent. */ if (mdev->state.conn < C_CONNECTED && evicted != LC_FREE) - drbd_bm_write_sect(mdev, evicted/AL_EXT_PER_BM_SECT); + drbd_bm_write_page(mdev, al_extent_to_bm_page(evicted)); /* The bitmap write may have failed, causing a state change. */ if (mdev->state.disk < D_INCONSISTENT) { @@ -635,105 +662,6 @@ out_bio_put: 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 (drbd_insert_fault(mdev, DRBD_FAULT_MD_WR)) { - bios[i]->bi_rw = WRITE; - bio_endio(bios[i], -EIO); - } else { - submit_bio(WRITE, bios[i]); - } - } - - /* 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. @@ -813,7 +741,7 @@ static int w_update_odbm(struct drbd_conf *mdev, struct drbd_work *w, int unused return 1; } - drbd_bm_write_sect(mdev, udw->enr); + drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr)); put_ldev(mdev); kfree(udw); @@ -893,7 +821,6 @@ static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector, 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; @@ -912,7 +839,6 @@ static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector, 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 { diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c index 8d959ed6c2cc..72cd41a96ef9 100644 --- a/drivers/block/drbd/drbd_bitmap.c +++ b/drivers/block/drbd/drbd_bitmap.c @@ -70,8 +70,7 @@ struct drbd_bitmap { sector_t bm_dev_capacity; struct mutex bm_change; /* serializes resize operations */ - atomic_t bm_async_io; - wait_queue_head_t bm_io_wait; + wait_queue_head_t bm_io_wait; /* used to serialize IO of single pages */ unsigned long bm_flags; @@ -82,7 +81,7 @@ struct drbd_bitmap { /* definition of bits in bm_flags */ #define BM_LOCKED 0 -#define BM_MD_IO_ERROR 1 +// #define BM_MD_IO_ERROR 1 unused now. #define BM_P_VMALLOCED 2 static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, @@ -155,26 +154,117 @@ void drbd_bm_unlock(struct drbd_conf *mdev) mutex_unlock(&b->bm_change); } -static unsigned int bm_bit_to_page_idx(struct drbd_bitmap *b, u64 bitnr) +/* we store some "meta" info about our pages in page->private */ +/* at a granularity of 4k storage per bitmap bit: + * one peta byte storage: 1<<50 byte, 1<<38 * 4k storage blocks + * 1<<38 bits, + * 1<<23 4k bitmap pages. + * Use 24 bits as page index, covers 2 peta byte storage + * at a granularity of 4k per bit. + * Used to report the failed page idx on io error from the endio handlers. + */ +#define BM_PAGE_IDX_MASK ((1UL<<24)-1) +/* this page is currently read in, or written back */ +#define BM_PAGE_IO_LOCK 31 +/* if there has been an IO error for this page */ +#define BM_PAGE_IO_ERROR 30 +/* this is to be able to intelligently skip disk IO, + * set if bits have been set since last IO. */ +#define BM_PAGE_NEED_WRITEOUT 29 +/* to mark for lazy writeout once syncer cleared all clearable bits, + * we if bits have been cleared since last IO. */ +#define BM_PAGE_LAZY_WRITEOUT 28 + +/* store_page_idx uses non-atomic assingment. It is only used directly after + * allocating the page. All other bm_set_page_* and bm_clear_page_* need to + * use atomic bit manipulation, as set_out_of_sync (and therefore bitmap + * changes) may happen from various contexts, and wait_on_bit/wake_up_bit + * requires it all to be atomic as well. */ +static void bm_store_page_idx(struct page *page, unsigned long idx) { - /* page_nr = (bitnr/8) >> PAGE_SHIFT; */ - unsigned int page_nr = bitnr >> (PAGE_SHIFT + 3); - BUG_ON(page_nr >= b->bm_number_of_pages); - return page_nr; + BUG_ON(0 != (idx & ~BM_PAGE_IDX_MASK)); + page_private(page) |= idx; } -/* word offset to long pointer */ -static unsigned long *__bm_map_paddr(struct drbd_bitmap *b, unsigned long offset, const enum km_type km) +static unsigned long bm_page_to_idx(struct page *page) { - struct page *page; - unsigned long page_nr; + return page_private(page) & BM_PAGE_IDX_MASK; +} + +/* As is very unlikely that the same page is under IO from more than one + * context, we can get away with a bit per page and one wait queue per bitmap. + */ +static void bm_page_lock_io(struct drbd_conf *mdev, int page_nr) +{ + struct drbd_bitmap *b = mdev->bitmap; + void *addr = &page_private(b->bm_pages[page_nr]); + wait_event(b->bm_io_wait, !test_and_set_bit(BM_PAGE_IO_LOCK, addr)); +} + +static void bm_page_unlock_io(struct drbd_conf *mdev, int page_nr) +{ + struct drbd_bitmap *b = mdev->bitmap; + void *addr = &page_private(b->bm_pages[page_nr]); + clear_bit(BM_PAGE_IO_LOCK, addr); + smp_mb__after_clear_bit(); + wake_up(&mdev->bitmap->bm_io_wait); +} + +/* set _before_ submit_io, so it may be reset due to being changed + * while this page is in flight... will get submitted later again */ +static void bm_set_page_unchanged(struct page *page) +{ + /* use cmpxchg? */ + clear_bit(BM_PAGE_NEED_WRITEOUT, &page_private(page)); + clear_bit(BM_PAGE_LAZY_WRITEOUT, &page_private(page)); +} + +static void bm_set_page_need_writeout(struct page *page) +{ + set_bit(BM_PAGE_NEED_WRITEOUT, &page_private(page)); +} + +static int bm_test_page_unchanged(struct page *page) +{ + volatile const unsigned long *addr = &page_private(page); + return (*addr & ((1UL<> PAGE_SHIFT; */ - page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3); + unsigned int page_nr = long_nr >> (PAGE_SHIFT - LN2_BPL + 3); BUG_ON(page_nr >= b->bm_number_of_pages); - page = b->bm_pages[page_nr]; + return page_nr; +} - return (unsigned long *) kmap_atomic(page, km); +static unsigned int bm_bit_to_page_idx(struct drbd_bitmap *b, u64 bitnr) +{ + /* page_nr = (bitnr/8) >> PAGE_SHIFT; */ + unsigned int page_nr = bitnr >> (PAGE_SHIFT + 3); + BUG_ON(page_nr >= b->bm_number_of_pages); + return page_nr; } static unsigned long *__bm_map_pidx(struct drbd_bitmap *b, unsigned int idx, const enum km_type km) @@ -188,11 +278,6 @@ static unsigned long *bm_map_pidx(struct drbd_bitmap *b, unsigned int idx) return __bm_map_pidx(b, idx, KM_IRQ1); } -static unsigned long * bm_map_paddr(struct drbd_bitmap *b, unsigned long offset) -{ - return __bm_map_paddr(b, offset, KM_IRQ1); -} - static void __bm_unmap(unsigned long *p_addr, const enum km_type km) { kunmap_atomic(p_addr, km); @@ -222,6 +307,7 @@ static void bm_unmap(unsigned long *p_addr) * to be able to report device specific. */ + static void bm_free_pages(struct page **pages, unsigned long number) { unsigned long i; @@ -289,6 +375,9 @@ static struct page **bm_realloc_pages(struct drbd_bitmap *b, unsigned long want) bm_vk_free(new_pages, vmalloced); return NULL; } + /* we want to know which page it is + * from the endio handlers */ + bm_store_page_idx(page, i); new_pages[i] = page; } } else { @@ -443,7 +532,7 @@ static unsigned long bm_count_bits(struct drbd_bitmap *b) while (offset < words) { i = do_now = min_t(size_t, words-offset, LWPP); - p_addr = __bm_map_paddr(b, offset, KM_USER0); + p_addr = __bm_map_pidx(b, bm_word_to_page_idx(b, offset), KM_USER0); bm = p_addr + MLPP(offset); while (i--) { bits += hweight_long(*bm++); @@ -472,6 +561,7 @@ static unsigned long bm_count_bits(struct drbd_bitmap *b) static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len) { unsigned long *p_addr, *bm; + unsigned int idx; size_t do_now, end; #define BM_SECTORS_PER_BIT (BM_BLOCK_SIZE/512) @@ -485,7 +575,8 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len) while (offset < end) { do_now = min_t(size_t, ALIGN(offset + 1, LWPP), end) - offset; - p_addr = bm_map_paddr(b, offset); + idx = bm_word_to_page_idx(b, offset); + p_addr = bm_map_pidx(b, idx); bm = p_addr + MLPP(offset); if (bm+do_now > p_addr + LWPP) { printk(KERN_ALERT "drbd: BUG BUG BUG! p_addr:%p bm:%p do_now:%d\n", @@ -494,6 +585,7 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len) } memset(bm, c, do_now * sizeof(long)); bm_unmap(p_addr); + bm_set_page_need_writeout(b->bm_pages[idx]); offset += do_now; } } @@ -604,7 +696,7 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits) bm_free_pages(opages + want, have - want); } - p_addr = bm_map_paddr(b, words); + p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, words)); bm = p_addr + MLPP(words); *bm = DRBD_MAGIC; bm_unmap(p_addr); @@ -616,7 +708,7 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits) bm_vk_free(opages, opages_vmalloced); if (!growing) b->bm_set = bm_count_bits(b); - dev_info(DEV, "resync bitmap: bits=%lu words=%lu\n", bits, words); + dev_info(DEV, "resync bitmap: bits=%lu words=%lu pages=%lu\n", bits, words, want); out: drbd_bm_unlock(mdev); @@ -686,6 +778,7 @@ void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, struct drbd_bitmap *b = mdev->bitmap; unsigned long *p_addr, *bm; unsigned long word, bits; + unsigned int idx; size_t end, do_now; end = offset + number; @@ -700,7 +793,8 @@ void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, spin_lock_irq(&b->bm_lock); while (offset < end) { do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset; - p_addr = bm_map_paddr(b, offset); + idx = bm_word_to_page_idx(b, offset); + p_addr = bm_map_pidx(b, idx); bm = p_addr + MLPP(offset); offset += do_now; while (do_now--) { @@ -710,6 +804,7 @@ void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, b->bm_set += hweight_long(word) - bits; } bm_unmap(p_addr); + bm_set_page_need_writeout(b->bm_pages[idx]); } /* with 32bit <-> 64bit cross-platform connect * this is only correct for current usage, @@ -748,7 +843,7 @@ void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, size_t number, else { while (offset < end) { do_now = min_t(size_t, ALIGN(offset+1, LWPP), end) - offset; - p_addr = bm_map_paddr(b, offset); + p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, offset)); bm = p_addr + MLPP(offset); offset += do_now; while (do_now--) @@ -786,9 +881,22 @@ void drbd_bm_clear_all(struct drbd_conf *mdev) spin_unlock_irq(&b->bm_lock); } +struct bm_aio_ctx { + struct drbd_conf *mdev; + atomic_t in_flight; + wait_queue_head_t io_wait; + unsigned flags; +#define BM_AIO_COPY_PAGES 1 + int error; +}; + +/* bv_page may be a copy, or may be the original */ static void bm_async_io_complete(struct bio *bio, int error) { - struct drbd_bitmap *b = bio->bi_private; + struct bm_aio_ctx *ctx = bio->bi_private; + struct drbd_conf *mdev = ctx->mdev; + struct drbd_bitmap *b = mdev->bitmap; + unsigned int idx = bm_page_to_idx(bio->bi_io_vec[0].bv_page); int uptodate = bio_flagged(bio, BIO_UPTODATE); @@ -799,35 +907,79 @@ static void bm_async_io_complete(struct bio *bio, int error) if (!error && !uptodate) error = -EIO; + if (!bm_test_page_unchanged(b->bm_pages[idx])) + dev_info(DEV, "bitmap page idx %u changed during IO!\n", idx); + if (error) { - /* doh. what now? - * for now, set all bits, and flag MD_IO_ERROR */ - __set_bit(BM_MD_IO_ERROR, &b->bm_flags); + /* ctx error will hold the completed-last non-zero error code, + * in case error codes differ. */ + ctx->error = error; + bm_set_page_io_err(b->bm_pages[idx]); + /* Not identical to on disk version of it. + * Is BM_PAGE_IO_ERROR enough? */ + if (__ratelimit(&drbd_ratelimit_state)) + dev_err(DEV, "IO ERROR %d on bitmap page idx %u\n", + error, idx); + } else { + bm_clear_page_io_err(b->bm_pages[idx]); + dynamic_dev_dbg(DEV, "bitmap page idx %u completed\n", idx); } - if (atomic_dec_and_test(&b->bm_async_io)) - wake_up(&b->bm_io_wait); + + bm_page_unlock_io(mdev, idx); + + /* FIXME give back to page pool */ + if (ctx->flags & BM_AIO_COPY_PAGES) + put_page(bio->bi_io_vec[0].bv_page); bio_put(bio); + + if (atomic_dec_and_test(&ctx->in_flight)) + wake_up(&ctx->io_wait); } -static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int page_nr, int rw) __must_hold(local) +static void bm_page_io_async(struct bm_aio_ctx *ctx, int page_nr, int rw) __must_hold(local) { /* we are process context. we always get a bio */ struct bio *bio = bio_alloc(GFP_KERNEL, 1); + struct drbd_conf *mdev = ctx->mdev; + struct drbd_bitmap *b = mdev->bitmap; + struct page *page; unsigned int len; + sector_t on_disk_sector = mdev->ldev->md.md_offset + mdev->ldev->md.bm_offset; on_disk_sector += ((sector_t)page_nr) << (PAGE_SHIFT-9); /* this might happen with very small - * flexible external meta data device */ + * flexible external meta data device, + * or with PAGE_SIZE > 4k */ len = min_t(unsigned int, PAGE_SIZE, (drbd_md_last_sector(mdev->ldev) - on_disk_sector + 1)<<9); + /* serialize IO on this page */ + bm_page_lock_io(mdev, page_nr); + /* before memcpy and submit, + * so it can be redirtied any time */ + bm_set_page_unchanged(b->bm_pages[page_nr]); + + if (ctx->flags & BM_AIO_COPY_PAGES) { + /* FIXME alloc_page is good enough for now, but actually needs + * to use pre-allocated page pool */ + void *src, *dest; + page = alloc_page(__GFP_HIGHMEM|__GFP_WAIT); + dest = kmap_atomic(page, KM_USER0); + src = kmap_atomic(b->bm_pages[page_nr], KM_USER1); + memcpy(dest, src, PAGE_SIZE); + kunmap_atomic(src, KM_USER1); + kunmap_atomic(dest, KM_USER0); + bm_store_page_idx(page, page_nr); + } else + page = b->bm_pages[page_nr]; + bio->bi_bdev = mdev->ldev->md_bdev; bio->bi_sector = on_disk_sector; - bio_add_page(bio, b->bm_pages[page_nr], len, 0); - bio->bi_private = b; + bio_add_page(bio, page, len, 0); + bio->bi_private = ctx; bio->bi_end_io = bm_async_io_complete; if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD)) { @@ -841,36 +993,72 @@ static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int /* * bm_rw: read/write the whole bitmap from/to its on disk location. */ -static int bm_rw(struct drbd_conf *mdev, int rw) __must_hold(local) +static int bm_rw(struct drbd_conf *mdev, int rw, unsigned lazy_writeout_upper_idx) __must_hold(local) { + struct bm_aio_ctx ctx = + { .flags = lazy_writeout_upper_idx ? BM_AIO_COPY_PAGES : 0 }; struct drbd_bitmap *b = mdev->bitmap; - /* sector_t sector; */ - int bm_words, num_pages, i; + int last_page, i, count = 0; unsigned long now; char ppb[10]; int err = 0; - WARN_ON(!bm_is_locked(b)); - - /* no spinlock here, the drbd_bm_lock should be enough! */ + /* + * We are protected against bitmap disappearing/resizing by holding an + * ldev reference (caller must have called get_ldev()). + * For read/write, we are protected against changes to the bitmap by + * the bitmap lock (see drbd_bitmap_io). + * For lazy writeout, we don't care for ongoing changes to the bitmap, + * as we submit copies of pages anyways. + */ + if (!ctx.flags) + WARN_ON(!bm_is_locked(b)); - bm_words = drbd_bm_words(mdev); - num_pages = (bm_words*sizeof(long) + PAGE_SIZE-1) >> PAGE_SHIFT; + /* because of the "extra long to catch oob access" we allocate in + * drbd_bm_resize, bm_number_of_pages -1 is not necessarily the page + * containing the last _relevant_ bitmap word */ + last_page = bm_word_to_page_idx(b, b->bm_words - 1); now = jiffies; - atomic_set(&b->bm_async_io, num_pages); - __clear_bit(BM_MD_IO_ERROR, &b->bm_flags); + ctx.mdev = mdev; + atomic_set(&ctx.in_flight, 1); /* one extra ref */ + init_waitqueue_head(&ctx.io_wait); + ctx.error = 0; /* let the layers below us try to merge these bios... */ - for (i = 0; i < num_pages; i++) - bm_page_io_async(mdev, b, i, rw); + for (i = 0; i <= last_page; i++) { + /* ignore completely unchanged pages */ + if (lazy_writeout_upper_idx && i == lazy_writeout_upper_idx) + break; + if (rw & WRITE) { + if (bm_test_page_unchanged(b->bm_pages[i])) { + dynamic_dev_dbg(DEV, "skipped bm write for idx %u\n", i); + continue; + } + /* during lazy writeout, + * ignore those pages not marked for lazy writeout. */ + if (lazy_writeout_upper_idx && + !bm_test_page_lazy_writeout(b->bm_pages[i])) { + dynamic_dev_dbg(DEV, "skipped bm lazy write for idx %u\n", i); + continue; + } + } + atomic_inc(&ctx.in_flight); + bm_page_io_async(&ctx, i, rw); + ++count; + cond_resched(); + } - wait_event(b->bm_io_wait, atomic_read(&b->bm_async_io) == 0); + atomic_dec(&ctx.in_flight); /* drop the extra ref */ + wait_event(ctx.io_wait, atomic_read(&ctx.in_flight) == 0); + dev_info(DEV, "bitmap %s of %u pages took %lu jiffies\n", + rw == WRITE ? "WRITE" : "READ", + count, jiffies - now); - if (test_bit(BM_MD_IO_ERROR, &b->bm_flags)) { + if (ctx.error) { dev_alert(DEV, "we had at least one MD IO ERROR during bitmap IO\n"); drbd_chk_io_error(mdev, 1, true); - err = -EIO; + err = -EIO; /* ctx.error ? */ } now = jiffies; @@ -895,55 +1083,63 @@ static int bm_rw(struct drbd_conf *mdev, int rw) __must_hold(local) */ int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local) { - return bm_rw(mdev, READ); + return bm_rw(mdev, READ, 0); } /** * drbd_bm_write() - Write the whole bitmap to its on disk location. * @mdev: DRBD device. + * + * Will only write pages that have changed since last IO. */ int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local) { - return bm_rw(mdev, WRITE); + return bm_rw(mdev, WRITE, 0); } /** - * drbd_bm_write_sect: Writes a 512 (MD_SECTOR_SIZE) byte piece of the bitmap + * drbd_bm_lazy_write_out() - Write bitmap pages 0 to @upper_idx-1, if they have changed. * @mdev: DRBD device. - * @enr: Extent number in the resync lru (happens to be sector offset) + * @upper_idx: 0: write all changed pages; +ve: page index to stop scanning for changed pages + */ +int drbd_bm_write_lazy(struct drbd_conf *mdev, unsigned upper_idx) __must_hold(local) +{ + return bm_rw(mdev, WRITE, upper_idx); +} + + +/** + * drbd_bm_write_page: Writes a PAGE_SIZE aligned piece of bitmap + * @mdev: DRBD device. + * @idx: bitmap page index * - * The BM_EXT_SIZE is on purpose exactly the amount of the bitmap covered - * by a single sector write. Therefore enr == sector offset from the - * start of the bitmap. + * We don't want to special case on logical_block_size of the underlaying + * device, so we submit PAGE_SIZE aligned pieces containing the requested enr. + * Note that on "most" systems, PAGE_SIZE is 4k. */ -int drbd_bm_write_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local) +int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(local) { - sector_t on_disk_sector = enr + mdev->ldev->md.md_offset - + mdev->ldev->md.bm_offset; - int bm_words, num_words, offset; - int err = 0; + struct bm_aio_ctx ctx = { .flags = BM_AIO_COPY_PAGES, }; - mutex_lock(&mdev->md_io_mutex); - bm_words = drbd_bm_words(mdev); - offset = S2W(enr); /* word offset into bitmap */ - num_words = min(S2W(1), bm_words - offset); - if (num_words < S2W(1)) - memset(page_address(mdev->md_io_page), 0, MD_SECTOR_SIZE); - drbd_bm_get_lel(mdev, offset, num_words, - page_address(mdev->md_io_page)); - if (!drbd_md_sync_page_io(mdev, mdev->ldev, on_disk_sector, WRITE)) { - int i; - err = -EIO; - dev_err(DEV, "IO ERROR writing bitmap sector %lu " - "(meta-disk sector %llus)\n", - enr, (unsigned long long)on_disk_sector); - drbd_chk_io_error(mdev, 1, true); - for (i = 0; i < AL_EXT_PER_BM_SECT; i++) - drbd_bm_ALe_set_all(mdev, enr*AL_EXT_PER_BM_SECT+i); + if (bm_test_page_unchanged(mdev->bitmap->bm_pages[idx])) { + dev_info(DEV, "skipped bm page write for idx %u\n", idx); + return 0; } + + ctx.mdev = mdev; + atomic_set(&ctx.in_flight, 1); + init_waitqueue_head(&ctx.io_wait); + + bm_page_io_async(&ctx, idx, WRITE_SYNC); + wait_event(ctx.io_wait, atomic_read(&ctx.in_flight) == 0); + + if (ctx.error) + drbd_chk_io_error(mdev, 1, true); + /* that should force detach, so the in memory bitmap will be + * gone in a moment as well. */ + mdev->bm_writ_cnt++; - mutex_unlock(&mdev->md_io_mutex); - return err; + return ctx.error; } /* NOTE @@ -965,10 +1161,9 @@ static unsigned long __bm_find_next(struct drbd_conf *mdev, unsigned long bm_fo, dev_err(DEV, "bm_fo=%lu bm_bits=%lu\n", bm_fo, b->bm_bits); } else { while (bm_fo < b->bm_bits) { - unsigned long offset; - bit_offset = bm_fo & ~BPP_MASK; /* bit offset of the page */ - offset = bit_offset >> LN2_BPL; /* word offset of the page */ - p_addr = __bm_map_paddr(b, offset, km); + /* bit offset of the first bit in the page */ + bit_offset = bm_fo & ~BPP_MASK; + p_addr = __bm_map_pidx(b, bm_bit_to_page_idx(b, bm_fo), km); if (find_zero_bit) i = generic_find_next_zero_le_bit(p_addr, PAGE_SIZE*8, bm_fo & BPP_MASK); @@ -1048,8 +1243,9 @@ static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, struct drbd_bitmap *b = mdev->bitmap; unsigned long *p_addr = NULL; unsigned long bitnr; - unsigned long last_page_nr = -1UL; + unsigned int last_page_nr = -1U; int c = 0; + int changed_total = 0; if (e >= b->bm_bits) { dev_err(DEV, "ASSERT FAILED: bit_s=%lu bit_e=%lu bm_bits=%lu\n", @@ -1057,12 +1253,17 @@ static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, e = b->bm_bits ? b->bm_bits -1 : 0; } for (bitnr = s; bitnr <= e; bitnr++) { - unsigned long offset = bitnr>>LN2_BPL; - unsigned long page_nr = offset >> (PAGE_SHIFT - LN2_BPL + 3); + unsigned int page_nr = bm_bit_to_page_idx(b, bitnr); if (page_nr != last_page_nr) { if (p_addr) __bm_unmap(p_addr, km); - p_addr = __bm_map_paddr(b, offset, km); + if (c < 0) + bm_set_page_lazy_writeout(b->bm_pages[last_page_nr]); + else if (c > 0) + bm_set_page_need_writeout(b->bm_pages[last_page_nr]); + changed_total += c; + c = 0; + p_addr = __bm_map_pidx(b, page_nr, km); last_page_nr = page_nr; } if (val) @@ -1072,8 +1273,13 @@ static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s, } if (p_addr) __bm_unmap(p_addr, km); - b->bm_set += c; - return c; + if (c < 0) + bm_set_page_lazy_writeout(b->bm_pages[last_page_nr]); + else if (c > 0) + bm_set_page_need_writeout(b->bm_pages[last_page_nr]); + changed_total += c; + b->bm_set += changed_total; + return changed_total; } /* returns number of bits actually changed. @@ -1211,8 +1417,7 @@ int drbd_bm_test_bit(struct drbd_conf *mdev, const unsigned long bitnr) if (bm_is_locked(b)) bm_print_lock_info(mdev); if (bitnr < b->bm_bits) { - unsigned long offset = bitnr>>LN2_BPL; - p_addr = bm_map_paddr(b, offset); + p_addr = bm_map_pidx(b, bm_bit_to_page_idx(b, bitnr)); i = generic_test_le_bit(bitnr & BPP_MASK, p_addr) ? 1 : 0; bm_unmap(p_addr); } else if (bitnr == b->bm_bits) { @@ -1231,10 +1436,10 @@ int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsi { unsigned long flags; struct drbd_bitmap *b = mdev->bitmap; - unsigned long *p_addr = NULL, page_nr = -1; + unsigned long *p_addr = NULL; unsigned long bitnr; + unsigned int page_nr = -1U; int c = 0; - size_t w; /* If this is called without a bitmap, that is a bug. But just to be * robust in case we screwed up elsewhere, in that case pretend there @@ -1247,12 +1452,12 @@ int drbd_bm_count_bits(struct drbd_conf *mdev, const unsigned long s, const unsi if (bm_is_locked(b)) bm_print_lock_info(mdev); for (bitnr = s; bitnr <= e; bitnr++) { - w = bitnr >> LN2_BPL; - if (page_nr != w >> (PAGE_SHIFT - LN2_BPL + 3)) { - page_nr = w >> (PAGE_SHIFT - LN2_BPL + 3); + unsigned int idx = bm_bit_to_page_idx(b, bitnr); + if (page_nr != idx) { + page_nr = idx; if (p_addr) bm_unmap(p_addr); - p_addr = bm_map_paddr(b, w); + p_addr = bm_map_pidx(b, idx); } ERR_IF (bitnr >= b->bm_bits) { dev_err(DEV, "bitnr=%lu bm_bits=%lu\n", bitnr, b->bm_bits); @@ -1300,7 +1505,7 @@ int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr) count = 0; if (s < b->bm_words) { int n = e-s; - p_addr = bm_map_paddr(b, s); + p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, s)); bm = p_addr + MLPP(s); while (n--) count += hweight_long(*bm++); @@ -1335,7 +1540,7 @@ unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, unsigned long al_enr) count = 0; if (s < b->bm_words) { i = do_now = e-s; - p_addr = bm_map_paddr(b, s); + p_addr = bm_map_pidx(b, bm_word_to_page_idx(b, s)); bm = p_addr + MLPP(s); while (i--) { count += hweight_long(*bm); diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index f6da48bb8c70..74cc50a21822 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -833,7 +833,7 @@ enum { CRASHED_PRIMARY, /* This node was a crashed primary. * Gets cleared when the state.conn * goes into C_CONNECTED state. */ - WRITE_BM_AFTER_RESYNC, /* A kmalloc() during resync failed */ + NO_BARRIER_SUPP, /* underlying block device doesn't implement barriers */ CONSIDER_RESYNC, MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */ @@ -1428,7 +1428,7 @@ extern void _drbd_bm_set_bits(struct drbd_conf *mdev, const unsigned long s, const unsigned long e); extern int drbd_bm_test_bit(struct drbd_conf *mdev, unsigned long bitnr); extern int drbd_bm_e_weight(struct drbd_conf *mdev, unsigned long enr); -extern int drbd_bm_write_sect(struct drbd_conf *mdev, unsigned long enr) __must_hold(local); +extern int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(local); extern int drbd_bm_read(struct drbd_conf *mdev) __must_hold(local); extern int drbd_bm_write(struct drbd_conf *mdev) __must_hold(local); extern unsigned long drbd_bm_ALe_set_all(struct drbd_conf *mdev, @@ -1446,7 +1446,7 @@ extern int drbd_bm_rs_done(struct drbd_conf *mdev); /* for receive_bitmap */ extern void drbd_bm_merge_lel(struct drbd_conf *mdev, size_t offset, size_t number, unsigned long *buffer); -/* for _drbd_send_bitmap and drbd_bm_write_sect */ +/* for _drbd_send_bitmap */ extern void drbd_bm_get_lel(struct drbd_conf *mdev, size_t offset, size_t number, unsigned long *buffer); @@ -1641,7 +1641,6 @@ extern int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, #define drbd_set_out_of_sync(mdev, sector, size) \ __drbd_set_out_of_sync(mdev, sector, size, __FILE__, __LINE__) extern void drbd_al_apply_to_bm(struct drbd_conf *mdev); -extern void drbd_al_to_on_disk_bm(struct drbd_conf *mdev); extern void drbd_al_shrink(struct drbd_conf *mdev); diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 67fffad213ec..57ed7181742d 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -1289,6 +1289,26 @@ static void abw_start_sync(struct drbd_conf *mdev, int rv) } } +int drbd_bitmap_io_from_worker(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *), char *why) +{ + int rv; + + D_ASSERT(current == mdev->worker.task); + + /* open coded non-blocking drbd_suspend_io(mdev); */ + set_bit(SUSPEND_IO, &mdev->flags); + if (!is_susp(mdev->state)) + D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0); + + drbd_bm_lock(mdev, why); + rv = io_fn(mdev); + drbd_bm_unlock(mdev); + + drbd_resume_io(mdev); + + return rv; +} + /** * after_state_ch() - Perform after state change actions that may sleep * @mdev: DRBD device. @@ -1404,7 +1424,12 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os, /* D_DISKLESS Peer becomes secondary */ if (os.peer == R_PRIMARY && ns.peer == R_SECONDARY) - drbd_al_to_on_disk_bm(mdev); + drbd_bitmap_io_from_worker(mdev, &drbd_bm_write, "demote diskless peer"); + put_ldev(mdev); + } + + if (os.role == R_PRIMARY && ns.role == R_SECONDARY && get_ldev(mdev)) { + drbd_bitmap_io_from_worker(mdev, &drbd_bm_write, "demote"); put_ldev(mdev); } diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 2f0724982143..77dc022eaf6b 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -407,10 +407,8 @@ drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, int force) } } - if ((new_role == R_SECONDARY) && get_ldev(mdev)) { - drbd_al_to_on_disk_bm(mdev); - put_ldev(mdev); - } + /* writeout of activity log covered areas of the bitmap + * to stable storage done in after state change already */ if (mdev->state.conn >= C_WF_REPORT_PARAMS) { /* if this was forced, we should consider sync */ @@ -1174,7 +1172,10 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp if (cp_discovered) { drbd_al_apply_to_bm(mdev); - drbd_al_to_on_disk_bm(mdev); + if (drbd_bitmap_io(mdev, &drbd_bm_write, "crashed primary apply AL")) { + retcode = ERR_IO_MD_DISK; + goto force_diskless_dec; + } } if (_drbd_bm_total_weight(mdev) == drbd_bm_bits(mdev)) diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 9fe3e890da0f..d17f2ed777ce 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -907,10 +907,8 @@ out: drbd_md_sync(mdev); - if (test_and_clear_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags)) { - dev_info(DEV, "Writing the whole bitmap\n"); - drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished"); - } + dev_info(DEV, "Writing changed bitmap pages\n"); + drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished"); if (khelper_cmd) drbd_khelper(mdev, khelper_cmd); @@ -1127,7 +1125,6 @@ void drbd_ov_oos_found(struct drbd_conf *mdev, sector_t sector, int size) 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)