On Fri, Jun 04, 2021 at 07:58:57PM +0000, Satya Tangirala wrote:
> Handle any error from blk_ksm_register() in the callers. Previously,
> the callers ignored the return value because blk_ksm_register() wouldn't
> fail as long as the request_queue didn't have integrity support too, but
> as this is no longer the case, it's safer for the callers to just handle
> the return value appropriately.
>
> Signed-off-by: Satya Tangirala <satyat@xxxxxxxxxx>
> ---
> drivers/mmc/core/crypto.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
> index 419a368f8402..cccd8c7d7e7a 100644
> --- a/drivers/mmc/core/crypto.c
> +++ b/drivers/mmc/core/crypto.c
> @@ -21,8 +21,17 @@ void mmc_crypto_set_initial_state(struct mmc_host *host)
>
> void mmc_crypto_setup_queue(struct request_queue *q, struct mmc_host *host)
> {
> - if (host->caps2 & MMC_CAP2_CRYPTO)
> - blk_ksm_register(&host->ksm, q);
> + if (host->caps2 & MMC_CAP2_CRYPTO) {
> + /*
> + * This WARN_ON should never trigger since &host->ksm won't be
> + * "empty" (i.e. will support at least 1 crypto capability), an
> + * MMC device's request queue doesn't support integrity, and
> + * it also satisfies all the block layer constraints (i.e.
> + * supports SG gaps, doesn't have chunk sectors, has a
> + * sufficiently large supported max_segments per bio)
> + */
> + WARN_ON(!blk_ksm_register(&host->ksm, q));
> + }
> }
There appear to be some MMC host drivers that set max_segments to 1, so this
explanation may not hold. It may hold for every driver that actually supports
crypto, though.
- Eric
