Re: [PATCH rc8-mm1] hotfix libata-scsi corruption

Jeff Garzik
2008-01-22T20:32:18Z

James Bottomley wrote:
> Actually, I don't think it's a smaller I/O issue. The SMART protocol
> specifically mandates that the transfers for SMART READ DATA and SMART
> READ LOG shall be 512 bytes). However, the pio transfer routine does
> seem to be assuming sector alignment as well, which will be where your
> problems are coming from. I think we need to specify sector minimum
> alignment for ata (but not atapi, which has its own non sector size pio
> routine). How about the attached?
>
> We have to do this for all ATA devices, because they'll likely all
> support SMART, and SMART is defined to be a PIO command.
>
> James
>
> ---
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 4bb268b..bc5cf6b 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -824,9 +824,6 @@ static void ata_scsi_sdev_config(struct scsi_device *sdev)
> * requests.
> */
> sdev->max_device_blocked = 1;
> -
> - /* set the min alignment */
> - blk_queue_update_dma_alignment(sdev->request_queue, ATA_DMA_PAD_SZ - 1);
> }
>
> static void ata_scsi_dev_config(struct scsi_device *sdev,
> @@ -842,7 +839,14 @@ static void ata_scsi_dev_config(struct scsi_device *sdev,
> if (dev->class == ATA_DEV_ATAPI) {
> struct request_queue *q = sdev->request_queue;
> blk_queue_max_hw_segments(q, q->max_hw_segments - 1);
> - }
> +
> + /* set the min alignment */
> + blk_queue_update_dma_alignment(sdev->request_queue,
> + ATA_DMA_PAD_SZ - 1);
> + } else
> + /* ATA devices must be sector aligned */
> + blk_queue_update_dma_alignment(sdev->request_queue,
> + ATA_SECT_SIZE - 1);
>
> if (dev->flags & ATA_DFLAG_AN)
> set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);

ACK

Unlike ATAPI, ATA is indeed all 512-byte alignment transfers (_not_
sector size, which may or may not be 512 bytes)

Does this apply to libata? libata + jejb dma alignment patch?

What tree...

Jeff