[PATCH v9 2/9] block: blk-crypto: relax alignment requirements for bvecs in bios

Satya Tangirala
2021-06-04T21:09:33Z

blk-crypto only accepted bios whose bvecs' offsets and lengths were aligned
to the crypto data unit size, since blk-crypto-fallback required that to
work correctly.

Now that the blk-crypto-fallback has been updated to work without that
assumption, we relax the alignment requirement - blk-crypto now only needs
the total size of the bio to be aligned to the crypto data unit size.

Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
---
block/blk-crypto.c | 19 ++-----------------
1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index c5bdaafffa29..06f81e64151d 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -200,22 +200,6 @@ bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
return !bc1 || bio_crypt_dun_is_contiguous(bc1, bc1_bytes, bc2->bc_dun);
}

-/* Check that all I/O segments are data unit aligned. */
-static bool bio_crypt_check_alignment(struct bio *bio)
-{
- const unsigned int data_unit_size =
- bio->bi_crypt_context->bc_key->crypto_cfg.data_unit_size;
- struct bvec_iter iter;
- struct bio_vec bv;
-
- bio_for_each_segment(bv, bio, iter) {
- if (!IS_ALIGNED(bv.bv_len | bv.bv_offset, data_unit_size))
- return false;
- }
-
- return true;
-}
-
blk_status_t __blk_crypto_init_request(struct request *rq)
{
return blk_ksm_get_slot_for_key(rq->q->ksm, rq->crypt_ctx->bc_key,
@@ -271,7 +255,8 @@ bool __blk_crypto_bio_prep(struct bio **bio_ptr)
goto fail;
}

- if (!bio_crypt_check_alignment(bio)) {
+ if (!IS_ALIGNED(bio->bi_iter.bi_size,
+ bc_key->crypto_cfg.data_unit_size)) {
bio->bi_status = BLK_STS_IOERR;
goto fail;
}
--
2.32.0.rc1.229.g3e70b5a671-goog