Obviously the created discard bio has to be aligned with logical block size.

This patch introduces the helper of bio_allowed_max_sectors() for this purpose.

Fixes: 744889b7cbb56a6 ("block: don't deal with discard limit in blkdev_issue_discard()") Fixes: a22c4d7e34402cc ("block: re-add discard_granularity and alignment checks") Reported-by: Rui Salvaterra rsalvaterra@gmail.com Cc: Rui Salvaterra rsalvaterra@gmail.com 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 Signed-off-by: Ming Lei ming.lei@redhat.com --- block/blk-lib.c | 3 +-- block/blk-merge.c | 3 ++- block/blk.h | 10 ++++++++++ 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c index 76f867ea9a9b..d56fd159d2e8 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -57,8 +57,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,

if (!req_sects) goto fail; - if (req_sects > UINT_MAX >> 9) - req_sects = UINT_MAX >> 9; + req_sects = min(req_sects, bio_allowed_max_sectors(q));

end_sect = sector + req_sects;

diff --git a/block/blk-merge.c b/block/blk-merge.c index 42a46744c11b..507fbaa6b4c0 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -90,7 +90,8 @@ static struct bio *blk_bio_discard_split(struct request_queue *q, /* Zero-sector (unknown) and one-sector granularities are the same. */ granularity = max(q->limits.discard_granularity >> 9, 1U);

- max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); + max_discard_sectors = min(q->limits.max_discard_sectors, + bio_allowed_max_sectors(q)); max_discard_sectors -= max_discard_sectors % granularity;

if (unlikely(!max_discard_sectors)) { diff --git a/block/blk.h b/block/blk.h index a1841b8ff129..2680aa4fcd88 100644 --- a/block/blk.h +++ b/block/blk.h @@ -396,6 +396,16 @@ static inline unsigned long blk_rq_deadline(struct request *rq) }

/* + * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size + * is defined as 'unsigned int', meantime it has to aligned to with logical + * block size which is the minimum accepted unit by hardware. + */ +static inline unsigned int bio_allowed_max_sectors(struct request_queue *q) +{ + return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9; +} + +/* * Internal io_context interface */ void get_io_context(struct io_context *ioc);