The BIO isuuing loop in __blkdev_issue_zeroout() was allocating BIOs with a maximum number of pages equal to
min(nr_sects, (sector_t)BIO_MAX_PAGES) This works since the BIO will always be limited to the absolute maximum number of pages, but can be ineficient as too many pages may be requested since variables with different units (number of sectors vs number of pages) are used in the min() operation. Fix this by correctly using the same unit (number of pages). Also remove a trailing space after the bit shift in the internal loop min() call. Signed-off-by: Damien Le Moal <[email protected]> --- block/blk-lib.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index e8caecd..7856447 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -307,14 +307,15 @@ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, ret = 0; while (nr_sects != 0) { - bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES), + bio = next_bio(bio, min((nr_sects << 9) >> PAGE_SHIFT, + (sector_t)BIO_MAX_PAGES), gfp_mask); bio->bi_iter.bi_sector = sector; bio->bi_bdev = bdev; bio_set_op_attrs(bio, REQ_OP_WRITE, 0); while (nr_sects != 0) { - sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects); + sz = min((sector_t) PAGE_SIZE >> 9, nr_sects); bi_size = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0); nr_sects -= bi_size >> 9; sector += bi_size >> 9; -- 2.9.4
