From 6675700139a0f642097c1166b2f958b2e5439c57 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Wed, 22 Jun 2022 22:49:32 +0200 Subject: drbd: bm_page_async_io: fix spurious bitmap "IO error" on large volumes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We usually do all our bitmap IO in units of PAGE_SIZE. With very small or oddly sized external meta data, or with PAGE_SIZE != 4k, it can happen that our last on-disk bitmap page is not fully PAGE_SIZE aligned, so we may need to adjust the size of the IO. We used to do that with min_t(unsigned int, PAGE_SIZE, last_allowed_sector - current_offset); And for just the right diff, (unsigned int)(diff) will result in 0. A bio of length 0 will correctly be rejected with an IO error (and some scary WARN_ON_ONCE()) by the scsi layer. Do the calculation properly. Signed-off-by: Lars Ellenberg Signed-off-by: Christoph Böhmwalder Link: https://lore.kernel.org/r/20220622204932.196830-1-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_bitmap.c | 49 ++++++++++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 7 deletions(-) (limited to 'drivers/block/drbd/drbd_bitmap.c') diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c index 603f6828dd79..7d9db33363de 100644 --- a/drivers/block/drbd/drbd_bitmap.c +++ b/drivers/block/drbd/drbd_bitmap.c @@ -974,25 +974,58 @@ static void drbd_bm_endio(struct bio *bio) } } +/* For the layout, see comment above drbd_md_set_sector_offsets(). */ +static inline sector_t drbd_md_last_bitmap_sector(struct drbd_backing_dev *bdev) +{ + switch (bdev->md.meta_dev_idx) { + case DRBD_MD_INDEX_INTERNAL: + case DRBD_MD_INDEX_FLEX_INT: + return bdev->md.md_offset + bdev->md.al_offset -1; + case DRBD_MD_INDEX_FLEX_EXT: + default: + return bdev->md.md_offset + bdev->md.md_size_sect -1; + } +} + static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_hold(local) { struct drbd_device *device = ctx->device; enum req_op op = ctx->flags & BM_AIO_READ ? REQ_OP_READ : REQ_OP_WRITE; - struct bio *bio = bio_alloc_bioset(device->ldev->md_bdev, 1, op, - GFP_NOIO, &drbd_md_io_bio_set); struct drbd_bitmap *b = device->bitmap; + struct bio *bio; struct page *page; + sector_t last_bm_sect; + sector_t first_bm_sect; + sector_t on_disk_sector; unsigned int len; - sector_t on_disk_sector = - device->ldev->md.md_offset + device->ldev->md.bm_offset; - on_disk_sector += ((sector_t)page_nr) << (PAGE_SHIFT-9); + first_bm_sect = device->ldev->md.md_offset + device->ldev->md.bm_offset; + on_disk_sector = first_bm_sect + (((sector_t)page_nr) << (PAGE_SHIFT-SECTOR_SHIFT)); /* this might happen with very small * flexible external meta data device, * or with PAGE_SIZE > 4k */ - len = min_t(unsigned int, PAGE_SIZE, - (drbd_md_last_sector(device->ldev) - on_disk_sector + 1)<<9); + last_bm_sect = drbd_md_last_bitmap_sector(device->ldev); + if (first_bm_sect <= on_disk_sector && last_bm_sect >= on_disk_sector) { + sector_t len_sect = last_bm_sect - on_disk_sector + 1; + if (len_sect < PAGE_SIZE/SECTOR_SIZE) + len = (unsigned int)len_sect*SECTOR_SIZE; + else + len = PAGE_SIZE; + } else { + if (__ratelimit(&drbd_ratelimit_state)) { + drbd_err(device, "Invalid offset during on-disk bitmap access: " + "page idx %u, sector %llu\n", page_nr, on_disk_sector); + } + ctx->error = -EIO; + bm_set_page_io_err(b->bm_pages[page_nr]); + if (atomic_dec_and_test(&ctx->in_flight)) { + ctx->done = 1; + wake_up(&device->misc_wait); + kref_put(&ctx->kref, &drbd_bm_aio_ctx_destroy); + } + return; + } /* serialize IO on this page */ bm_page_lock_io(device, page_nr); @@ -1007,6 +1040,8 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho bm_store_page_idx(page, page_nr); } else page = b->bm_pages[page_nr]; + bio = bio_alloc_bioset(device->ldev->md_bdev, 1, op, GFP_NOIO, + &drbd_md_io_bio_set); bio->bi_iter.bi_sector = on_disk_sector; /* bio_add_page of a single page to an empty bio will always succeed, * according to api. Do we want to assert that? */ -- cgit v1.2.3