This was done to prevent boot time scanning of the block device.
Thanks
Tomas
On Mon, Aug 21, 2017 at 3:51 PM, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> On 21/08/17 00:39, Linus Walleij wrote:
>> This function is used by the block layer queue to bail out of
>> requests if the current request is an RPMB request.
>>
>> However this makes no sense: RPMB is only used from ioctl():s,
>> there are no RPMB accesses coming from the block layer.
>> An RPMB ioctl() always switches to the RPMB partition and
>> then back to the main partition before completing.
>>
>> The only (possible) use of this check must have been to
>> duct-tape over a race between RPMB ioctl()s colliding with
>> concurrent non-RPMB accesses to the same device.
>
> It was always possible to read / write (unsuccessfully) the rpmb block
> device. i.e. dd of=/dev/mmcblk0rpmb
>
> Actually one thing to look at is that it looks like it was blocking your
> IOCTL requests. i.e. wouldn't the IOCTL request also get killed.
>
>>
>> This could happen in the past because the RPMB device was
>> created as a separate block device/disk with its own submit
>> queue competing with the main partition, and submitting
>> requests in parallel. This is now gone as we removed the
>> offending RPMB block device in another patch.
>>
>> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
>> ---
>> ChangeLog v1->v5:
>> - Renumber to keep together with the rest of the series.
>> ---
>> drivers/mmc/core/block.c | 12 ------------
>> drivers/mmc/core/queue.c | 2 +-
>> drivers/mmc/core/queue.h | 2 --
>> 3 files changed, 1 insertion(+), 15 deletions(-)
>>
>> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
>> index 27e1cf07a7a2..61ea402f2569 100644
>> --- a/drivers/mmc/core/block.c
>> +++ b/drivers/mmc/core/block.c
>> @@ -1207,18 +1207,6 @@ static inline void mmc_blk_reset_success(struct mmc_blk_data *md, int type)
>> md->reset_done &= ~type;
>> }
>>
>> -int mmc_access_rpmb(struct mmc_queue *mq)
>> -{
>> - struct mmc_blk_data *md = mq->blkdata;
>> - /*
>> - * If this is a RPMB partition access, return ture
>> - */
>> - if (md && md->part_type == EXT_CSD_PART_CONFIG_ACC_RPMB)
>> - return true;
>> -
>> - return false;
>> -}
>> -
>> /*
>> * The non-block commands come back from the block layer after it queued it and
>> * processed it with all other requests and then they get issued in this
>> diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
>> index affa7370ba82..3baccbf16f3d 100644
>> --- a/drivers/mmc/core/queue.c
>> +++ b/drivers/mmc/core/queue.c
>> @@ -32,7 +32,7 @@ static int mmc_prep_request(struct request_queue *q, struct request *req)
>> {
>> struct mmc_queue *mq = q->queuedata;
>>
>> - if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
>> + if (mq && mmc_card_removed(mq->card))
>> return BLKPREP_KILL;
>>
>> req->rq_flags |= RQF_DONTPREP;
>> diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h
>> index a2b6a9fcab01..7649ed6cbef7 100644
>> --- a/drivers/mmc/core/queue.h
>> +++ b/drivers/mmc/core/queue.h
>> @@ -89,6 +89,4 @@ extern unsigned int mmc_queue_map_sg(struct mmc_queue *,
>> extern void mmc_queue_bounce_pre(struct mmc_queue_req *);
>> extern void mmc_queue_bounce_post(struct mmc_queue_req *);
>>
>> -extern int mmc_access_rpmb(struct mmc_queue *);
>> -
>> #endif
>>
>
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