Boaz Harrosh wrote:
<snip>
>>
>>> Just to demonstrate what I mean a patch is attached. Just as an RFC, totally
>>> untested.
>> I can try this out and see what happens.
>>
>>
> Will not compile here is a cleaner one
Still in my queue. Hopefully I'll get to poke at this today.
Mike
>
> ---
> From: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
> Date: Wed, 12 Mar 2008 13:18:49 +0200
> Subject: [PATCH] scsi: Always complete BLOCK_PC commands
>
> Current code, in some IO combinations could wrongly retry
> a BLOCK_PC command in chunks. This was never intended.
> Fix it that BLOCK_PC will always complete atomically
>
> Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
> ---
> drivers/scsi/scsi_lib.c | 24 +++++++++++++-----------
> 1 files changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index ba21d97..4b8b57c 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -784,14 +784,20 @@ EXPORT_SYMBOL(scsi_release_buffers);
> * in req->data_len and req->next_rq->data_len. The upper-layer driver can
> * decide what to do with this information.
> */
> -void scsi_end_bidi_request(struct scsi_cmnd *cmd)
> +static void scsi_end_blk_request(struct scsi_cmnd *cmd)
> {
> struct request *req = cmd->request;
> unsigned int dlen = req->data_len;
> - unsigned int next_dlen = req->next_rq->data_len;
> + unsigned int next_dlen;
>
> - req->data_len = scsi_out(cmd)->resid;
> - req->next_rq->data_len = scsi_in(cmd)->resid;
> + if (blk_bidi_rq(req)) {
> + next_dlen = req->next_rq->data_len;
> + req->data_len = scsi_out(cmd)->resid;
> + req->next_rq->data_len = scsi_in(cmd)->resid;
> + } else {
> + next_dlen = 0;
> + req->data_len = scsi_get_resid(cmd);
> + }
>
> /* The req and req->next_rq have not been completed */
> BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen));
> @@ -866,15 +872,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
> req->sense_len = len;
> }
> }
> - if (scsi_bidi_cmnd(cmd)) {
> - /* will also release_buffers */
> - scsi_end_bidi_request(cmd);
> - return;
> - }
> - req->data_len = scsi_get_resid(cmd);
> + /* will also release_buffers */
> + scsi_end_blk_request(cmd);
> + return;
> }
>
> - BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */
> scsi_release_buffers(cmd);
>
> /*
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
