From: Keith Busch Fix up the divisor calculating the number of zone sectors being read and handle a read that straddles the zone write pointer. The length is rounded up a sector boundary, so be sure to truncate any excess bytes off to avoid copying past the data segment. Fixes: 3451cf34f51bb70 ("null_blk: allow byte aligned memory offsets") Signed-off-by: Keith Busch --- drivers/block/null_blk/main.c | 5 ++++- drivers/block/null_blk/zoned.c | 2 +- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index f1e67962ecaeb..c7c0fb79a6bf6 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -1240,9 +1240,12 @@ static blk_status_t null_transfer(struct nullb *nullb, struct page *page, p = kmap_local_page(page) + off; if (!is_write) { - if (dev->zoned) + if (dev->zoned) { valid_len = null_zone_valid_read_len(nullb, pos >> SECTOR_SHIFT, len); + if (valid_len && valid_len != len) + valid_len -= pos & (SECTOR_SIZE - 1); + } if (valid_len) { copy_from_nullb(nullb, p, pos, valid_len); diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c index dbf292a8eae96..0ada35dc0989e 100644 --- a/drivers/block/null_blk/zoned.c +++ b/drivers/block/null_blk/zoned.c @@ -242,7 +242,7 @@ size_t null_zone_valid_read_len(struct nullb *nullb, { struct nullb_device *dev = nullb->dev; struct nullb_zone *zone = &dev->zones[null_zone_no(dev, sector)]; - unsigned int nr_sectors = DIV_ROUND_UP(len, SECTOR_SHIFT); + unsigned int nr_sectors = DIV_ROUND_UP(len, SECTOR_SIZE); /* Read must be below the write pointer position */ if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL || -- 2.47.3