On Sun, 2017-08-13 at 22:47 -0400, Mikulas Patocka wrote: > > On Wed, 9 Aug 2017, hch@xxxxxx wrote: > > > Does commit 615d22a51c04856efe62af6e1d5b450aaf5cc2c0 > > "block: Fix __blkdev_issue_zeroout loop" fix the issue for you? > > > > -- > > dm-devel mailing list > > dm-devel@xxxxxxxxxx > > https://www.redhat.com/mailman/listinfo/dm-devel > > I think that patch is incorrect. sector_t may be a 32-bit type and > nr_sects << 9 may overflow. > > static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects) > { > sector_t bytes = (nr_sects << 9) + PAGE_SIZE - 1; > > return min(bytes >> PAGE_SHIFT, (sector_t)BIO_MAX_PAGES); > } > > Mikulas Mikulas, Does the follwing patch fix the problem ? >From 947b3cf41e759b2b23f684e215e651d0c8037f88 Mon Sep 17 00:00:00 2001 From: Damien Le Moal <damien.lemoal@xxxxxxx> Date: Mon, 14 Aug 2017 13:01:16 +0900 Subject: [PATCH] block: Fix __blkdev_sectors_to_bio_pages() On 32bit systems where sector_t is a 32bits type, the calculation of bytes may overflow. Use the u64 type for the local calculation to avoid overflows. Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx> --- block/blk-lib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index 3fe0aec90597..ccf22dba21f0 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -269,9 +269,9 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev, */ static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects) { - sector_t bytes = (nr_sects << 9) + PAGE_SIZE - 1; + u64 bytes = ((u64)nr_sects << 9) + PAGE_SIZE - 1; - return min(bytes >> PAGE_SHIFT, (sector_t)BIO_MAX_PAGES); + return min(bytes >> PAGE_SHIFT, (u64)BIO_MAX_PAGES); } /** -- 2.13.4 -- Damien Le Moal Western Digital
