[dm-devel] RE: [PATCH 21/30] blk_end_request: changing cciss (take 4)

[Miller, Mike (OS Dev)]

>
> This patch converts cciss to use blk_end_request interfaces.
> Related 'uptodate' arguments are converted to 'error'.
>
> cciss is a little bit different from "normal" drivers.
> cciss directly calls bio_endio() and disk_stat_add() when
> completing request.  But those can be replaced with
> __end_that_request_first().
> After the replacement, request completion procedures of those
> drivers become like the following:
>     o end_that_request_first()
>     o add_disk_randomness()
>     o end_that_request_last()
> This can be converted to blk_end_request() by following the
> rule (a) mentioned in the patch subject "[PATCH 01/30]
> blk_end_request: add new request completion interface".
>
> Cc: Mike Miller <mike.miller at hp.com>
> Signed-off-by: Kiyoshi Ueda <k-ueda at ct.jp.nec.com>
> Signed-off-by: Jun'ichi Nomura <j-nomura at ce.jp.nec.com>
> ---
>  drivers/block/cciss.c |   25 +++----------------------
>  1 files changed, 3 insertions(+), 22 deletions(-)
>
> Index: 2.6.24-rc4/drivers/block/cciss.c
> ===================================================================
> --- 2.6.24-rc4.orig/drivers/block/cciss.c
> +++ 2.6.24-rc4/drivers/block/cciss.c
> @@ -1187,17 +1187,6 @@ static int cciss_ioctl(struct inode *ino
>         }
>  }
>
> -static inline void complete_buffers(struct bio *bio, int status) -{
> -       while (bio) {
> -               struct bio *xbh = bio->bi_next;
> -
> -               bio->bi_next = NULL;
> -               bio_endio(bio, status ? 0 : -EIO);
> -               bio = xbh;
> -       }
> -}
> -
>  static void cciss_check_queues(ctlr_info_t *h)  {
>         int start_queue = h->next_to_run; @@ -1263,21
> +1252,14 @@ static void cciss_softirq_done(struct re
>                 pci_unmap_page(h->pdev, temp64.val,
> cmd->SG[i].Len, ddir);
>         }
>
> -       complete_buffers(rq->bio, (rq->errors == 0));
> -
> -       if (blk_fs_request(rq)) {
> -               const int rw = rq_data_dir(rq);
> -
> -               disk_stat_add(rq->rq_disk, sectors[rw],
> rq->nr_sectors);
> -       }
> -
>  #ifdef CCISS_DEBUG
>         printk("Done with %p\n", rq);
>  #endif                         /* CCISS_DEBUG */
>
> -       add_disk_randomness(rq->rq_disk);
> +       if (blk_end_request(rq, (rq->errors == 0) ? 0 : -EIO,
> blk_rq_bytes(rq)))
> +               BUG();
> +
>         spin_lock_irqsave(&h->lock, flags);
> -       end_that_request_last(rq, (rq->errors == 0));
>         cmd_free(h, cmd, 1);
>         cciss_check_queues(h);
>         spin_unlock_irqrestore(&h->lock, flags); @@ -2544,7
> +2526,6 @@ after_error_processing:
>         }
>         cmd->rq->data_len = 0;
>         cmd->rq->completion_data = cmd;
> -       blk_add_trace_rq(cmd->rq->q, cmd->rq, BLK_TA_COMPLETE);

Why is this removed?

-- mikem

>         blk_complete_request(cmd->rq);
>  }
>
>