Re: [PATCH V3] mmc: Kill block requests if card is removed

[Sujit Reddy Thumma <sthumma@codeaurora.org>]

Hi Adrian/Per,

Any comments on this patch?

Thanks,
Sujit

On 12/1/2011 4:00 PM, Sujit Reddy Thumma wrote:
> Kill block requests when the host realizes that the card is
> removed from the slot and is sure that subsequent requests
> are bound to fail. Do this silently so that the block
> layer doesn't output unnecessary error messages.
>
> Signed-off-by: Sujit Reddy Thumma<sthumma@codeaurora.org>
>
> ---
> Changes in v3:
> 	- Dropped dependency on Per's patch and is now dependent
> 	on "[PATCH V4] mmc: allow upper layers to determine immediately
> 	if a card has been removed" by Adrian Hunter.
> 	- Modified commit text slightly as Adrian has
> 	implemented his own suggestion in a different patch.
>
> Changes in v2:
> 	- Changed the implementation with further comments from Adrian
> 	- Set the card removed flag in bus notifier callbacks
> 	- This patch is now dependent on patch from Per Forlin:
> 	http://thread.gmane.org/gmane.linux.kernel.mmc/11128/focus=11211
> ---
>   drivers/mmc/card/block.c |   14 +++++++++++++-
>   drivers/mmc/card/queue.c |    5 +++++
>   2 files changed, 18 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index c80bb6d..20350cb 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -119,6 +119,7 @@ enum mmc_blk_status {
>   	MMC_BLK_ABORT,
>   	MMC_BLK_DATA_ERR,
>   	MMC_BLK_ECC_ERR,
> +	MMC_BLK_NOMEDIUM,
>   };
>
>   module_param(perdev_minors, int, 0444);
> @@ -565,6 +566,7 @@ static int get_card_status(struct mmc_card *card, u32 *status, int retries)
>   	return err;
>   }
>
> +#define ERR_NOMEDIUM	3
>   #define ERR_RETRY	2
>   #define ERR_ABORT	1
>   #define ERR_CONTINUE	0
> @@ -648,8 +650,12 @@ static int mmc_blk_cmd_recovery(struct mmc_card *card, struct request *req,
>   	}
>
>   	/* We couldn't get a response from the card.  Give up. */
> -	if (err)
> +	if (err) {
> +		/* Check if the card is removed */
> +		if (mmc_detect_card_removed(card->host))
> +			return ERR_NOMEDIUM;
>   		return ERR_ABORT;
> +	}
>
>   	/* Flag ECC errors */
>   	if ((status&  R1_CARD_ECC_FAILED) ||
> @@ -922,6 +928,8 @@ static int mmc_blk_err_check(struct mmc_card *card,
>   			return MMC_BLK_RETRY;
>   		case ERR_ABORT:
>   			return MMC_BLK_ABORT;
> +		case ERR_NOMEDIUM:
> +			return MMC_BLK_NOMEDIUM;
>   		case ERR_CONTINUE:
>   			break;
>   		}
> @@ -1255,6 +1263,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
>   			if (!ret)
>   				goto start_new_req;
>   			break;
> +		case MMC_BLK_NOMEDIUM:
> +			goto cmd_abort;
>   		}
>
>   		if (ret) {
> @@ -1271,6 +1281,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
>
>    cmd_abort:
>   	spin_lock_irq(&md->lock);
> +	if (mmc_card_removed(card))
> +		req->cmd_flags |= REQ_QUIET;
>   	while (ret)
>   		ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
>   	spin_unlock_irq(&md->lock);
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index dcad59c..2517547 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -29,6 +29,8 @@
>    */
>   static int mmc_prep_request(struct request_queue *q, struct request *req)
>   {
> +	struct mmc_queue *mq = q->queuedata;
> +
>   	/*
>   	 * We only like normal block requests and discards.
>   	 */
> @@ -37,6 +39,9 @@ static int mmc_prep_request(struct request_queue *q, struct request *req)
>   		return BLKPREP_KILL;
>   	}
>
> +	if (mq&&  mmc_card_removed(mq->card))
> +		return BLKPREP_KILL;
> +
>   	req->cmd_flags |= REQ_DONTPREP;
>
>   	return BLKPREP_OK;