2022-05-20 17:22:17

by John Garry

Subject: [PATCH 4/4] libata-scsi: Cap ata_device->max_sectors according to shost->max_sectors

ATA devices (struct ata_device) have a max_sectors field which is
configured internally in libata. This is then used to (re)configure the
associated sdev request queue max_sectors value from how it is earlier set
in __scsi_init_queue(). In __scsi_init_queue() the max_sectors value is set
according to shost limits, which includes host DMA mapping limits.

Cap the ata_device max_sectors according to shost->max_sectors to respect
this shost limit.

Signed-off-by: John Garry <[email protected]>
---
drivers/ata/libata-scsi.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 06c9d90238d9..25fe89791641 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1036,6 +1036,7 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev)
dev->flags |= ATA_DFLAG_NO_UNLOAD;

/* configure max sectors */
+ dev->max_sectors = min(dev->max_sectors, sdev->host->max_sectors);
blk_queue_max_hw_sectors(q, dev->max_sectors);

if (dev->class == ATA_DEV_ATAPI) {
--
2.26.2

2022-05-22 11:37:04

by Damien Le Moal

Subject: Re: [PATCH 4/4] libata-scsi: Cap ata_device->max_sectors according to shost->max_sectors

On 5/20/22 17:23, John Garry wrote:
> ATA devices (struct ata_device) have a max_sectors field which is
> configured internally in libata. This is then used to (re)configure the
> associated sdev request queue max_sectors value from how it is earlier set
> in __scsi_init_queue(). In __scsi_init_queue() the max_sectors value is set
> according to shost limits, which includes host DMA mapping limits.
>
> Cap the ata_device max_sectors according to shost->max_sectors to respect
> this shost limit.
>
> Signed-off-by: John Garry <[email protected]>
> ---
> drivers/ata/libata-scsi.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 06c9d90238d9..25fe89791641 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -1036,6 +1036,7 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev)
> dev->flags |= ATA_DFLAG_NO_UNLOAD;
>
> /* configure max sectors */
> + dev->max_sectors = min(dev->max_sectors, sdev->host->max_sectors);
> blk_queue_max_hw_sectors(q, dev->max_sectors);
>
> if (dev->class == ATA_DEV_ATAPI) {

Acked-by: Damien Le Moal <[email protected]>

--
Damien Le Moal
Western Digital Research