| Message ID | 20210604195900.2096121-3-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 Fri, Jun 04, 2021 at 07:58:52PM +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() must be aligned to blk_crypto_bio_sectors_alignment(). > > Signed-off-by: Satya Tangirala <satyat@google.com> > --- > block/blk-crypto-internal.h | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h > index 0d36aae538d7..7f1535cc7e7c 100644 > --- a/block/blk-crypto-internal.h > +++ b/block/blk-crypto-internal.h > @@ -60,6 +60,21 @@ 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. Note that a bio must contain a whole number of > + * crypto data units (which is selected by the submitter of bio), since > + * encryption/decryption can only be performed on a complete crypto data unit. > + */ > +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 +108,11 @@ 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 */ Looks fine, but I think we should rework the comment to be a bit easier to understand. Maybe: /* * Return the number of sectors to which the size of this bio (and any bios * split from it) must be aligned based on its encryption context. */ static inline unsigned int blk_crypto_bio_sectors_alignment(struct bio *bio) { if (!bio_has_crypt_ctx(bio)) return 1; /* * If the bio has an encryption context, its size must be aligned to its * crypto data unit size (which the submitter of the bio selected), as * encryption/decryption can only be done on complete crypto data units. */ return bio->bi_crypt_context->bc_key->crypto_cfg.data_unit_size >> SECTOR_SHIFT; }
diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h index 0d36aae538d7..7f1535cc7e7c 100644 --- a/block/blk-crypto-internal.h +++ b/block/blk-crypto-internal.h @@ -60,6 +60,21 @@ 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. Note that a bio must contain a whole number of + * crypto data units (which is selected by the submitter of bio), since + * encryption/decryption can only be performed on a complete crypto data unit. + */ +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 +108,11 @@ 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() must be aligned to blk_crypto_bio_sectors_alignment(). Signed-off-by: Satya Tangirala <satyat@google.com> --- block/blk-crypto-internal.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)