The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 34ffec60b27aa81d04e274e71e4c6ef740f75fc7 Mon Sep 17 00:00:00 2001

From: Ming Lei ming.lei@redhat.com Date: Mon, 29 Oct 2018 20:57:19 +0800 Subject: [PATCH] block: make sure writesame bio is aligned with logical block size

Obviously the created writesame bio has to be aligned with logical block size, and use bio_allowed_max_sectors() to retrieve this number.

Cc: stable@vger.kernel.org Cc: Mike Snitzer snitzer@redhat.com Cc: Christoph Hellwig hch@lst.de Cc: Xiao Ni xni@redhat.com Cc: Mariusz Dabrowski mariusz.dabrowski@intel.com Fixes: b49a0871be31a745b2ef ("block: remove split code in blkdev_issue_{discard,write_same}") Tested-by: Rui Salvaterra rsalvaterra@gmail.com Signed-off-by: Ming Lei ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk

diff --git a/block/blk-lib.c b/block/blk-lib.c index d58d5d87dd88..e8b3bb9bf375 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -149,7 +149,7 @@ static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector, return -EOPNOTSUPP;

/* Ensure that max_write_same_sectors doesn't overflow bi_size */ - max_write_same_sectors = UINT_MAX >> 9; + max_write_same_sectors = bio_allowed_max_sectors(q);

while (nr_sects) { bio = blk_next_bio(bio, 1, gfp_mask);