Re: [PATCH v4 9/9] block: add WARN_ON_ONCE() to bio_split() for sector alignment
From: Eric Biggers <ebiggers@kernel.org>
Date: 2021-07-23 17:30:49
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On Tue, Jul 06, 2021 at 10:29:43PM -0700, Satya Tangirala wrote:
From: Satya Tangirala <redacted> The number of sectors passed to bio_split() must be aligned to bio_required_sector_alignment(). All callers (other than bounce.c) have been updated to ensure this, so add a WARN_ON_ONCE() if the number of sectors is not aligned. (bounce.c was not updated since it's legacy code - any device that enables bounce buffering won't declare inline encryption support, so bounce.c will never see a bio with an encryption context).
The last sentence could say "so bounce.c will never see a bio with bio_required_sector_alignment() greater than the logical block size".
quoted hunk ↗ jump to hunk
Signed-off-by: Satya Tangirala <redacted> --- block/bio.c | 1 + 1 file changed, 1 insertion(+)diff --git a/block/bio.c b/block/bio.c index 1fab762e079b..4c7bfdeefe76 100644 --- a/block/bio.c +++ b/block/bio.c@@ -1435,6 +1435,7 @@ struct bio *bio_split(struct bio *bio, int sectors, BUG_ON(sectors <= 0); BUG_ON(sectors >= bio_sectors(bio)); + WARN_ON_ONCE(!IS_ALIGNED(sectors, bio_required_sector_alignment(bio))); /* Zone append commands cannot be split */ if (WARN_ON_ONCE(bio_op(bio) == REQ_OP_ZONE_APPEND))
Reviewed-by: Eric Biggers <redacted> - Eric