| Message ID | 20210325212609.492188-4-satyat@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ensure bios aren't split in middle of crypto data unit | expand |
On Thu, Mar 25, 2021 at 09:26:04PM +0000, Satya Tangirala wrote: > The size of any bio must be aligned to the data unit size of the bio crypt > context (if it exists) of that bio. This must also be ensured whenever a > bio is split. Introduce blk_crypto_bio_sectors_alignment() that returns > the required alignment in sectors. The number of sectors passed to > any call of bio_split() should be aligned to > blk_crypto_bio_sectors_alignment(). "should be aligned" => "must be aligned"? > +/* > + * Returns the alignment requirement for the number of sectors in this bio based > + * on its bi_crypt_context. Any bios split from this bio must follow this > + * alignment requirement as well. > + */ It would be helpful to expand this comment a bit to explictly mention that the size of the bio must be a multiple of the crypto data unit size that was selected by the submitter of the bio, which is the granularity of encryption/decryption. Keep in mind that people reading this code won't necessarily be familiar with inline encryption. - Eric
diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h index 0d36aae538d7..304e90ed99f5 100644 --- a/block/blk-crypto-internal.h +++ b/block/blk-crypto-internal.h @@ -60,6 +60,19 @@ static inline bool blk_crypto_rq_is_encrypted(struct request *rq) return rq->crypt_ctx; } +/* + * Returns the alignment requirement for the number of sectors in this bio based + * on its bi_crypt_context. Any bios split from this bio must follow this + * alignment requirement as well. + */ +static inline unsigned int blk_crypto_bio_sectors_alignment(struct bio *bio) +{ + if (!bio_has_crypt_ctx(bio)) + return 1; + return bio->bi_crypt_context->bc_key->crypto_cfg.data_unit_size >> + SECTOR_SHIFT; +} + #else /* CONFIG_BLK_INLINE_ENCRYPTION */ static inline bool bio_crypt_rq_ctx_compatible(struct request *rq, @@ -93,6 +106,11 @@ static inline bool blk_crypto_rq_is_encrypted(struct request *rq) return false; } +static inline unsigned int blk_crypto_bio_sectors_alignment(struct bio *bio) +{ + return 1; +} + #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
The size of any bio must be aligned to the data unit size of the bio crypt context (if it exists) of that bio. This must also be ensured whenever a bio is split. Introduce blk_crypto_bio_sectors_alignment() that returns the required alignment in sectors. The number of sectors passed to any call of bio_split() should be aligned to blk_crypto_bio_sectors_alignment(). Signed-off-by: Satya Tangirala <satyat@google.com> --- block/blk-crypto-internal.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)