Ewan,
I like it, more generic than my patch. I never saw the other cases, so I
limited my
patch to WS16.
Acked-by: Bill Kuzeja <william.kuz...@stratus.com>
On Tue-09-19 at 12:14 Ewan D. Milne wrote:
> Some devices do not support a WRITE SAME / WRITE SAME(16) with the
> UNMAP
> bit set up to the length specified in the MAXIMUM WRITE SAME LENGTH
> field
> in the block limits VPD page (or, the field is zero, indicating there is
> no limit). Limit the length by the MAXIMUM UNMAP LBA COUNT value.
> Otherwise the command might be rejected.
>
> Signed-off-by: Ewan D. Milne <emi...@redhat.com>
> ---
> drivers/scsi/sd.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 6549e5c..fa07ac2 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -693,6 +693,7 @@ static void sd_config_discard(struct scsi_disk *sdkp,
> unsigned int mode)
> struct request_queue *q = sdkp->disk->queue;
> unsigned int logical_block_size = sdkp->device->sector_size;
> unsigned int max_blocks = 0;
> + u32 max_ws_blocks = sdkp->max_ws_blocks;
>
> q->limits.discard_alignment =
> sdkp->unmap_alignment * logical_block_size;
> @@ -701,6 +702,13 @@ static void sd_config_discard(struct scsi_disk *sdkp,
> unsigned int mode)
> sdkp->unmap_granularity * logical_block_size);
> sdkp->provisioning_mode = mode;
>
> + /*
> + * Some devices limit WRITE SAME / WRITE SAME(16) w/UNMAP
> + * by MAXIMUM UNMAP LBA COUNT instead of MAXIMUM WRITE
> SAME LENGTH.
> + * Use the smaller of the two values to avoid ILLEGAL REQUEST
> errors.
> + */
> + max_ws_blocks = min_not_zero(max_ws_blocks, sdkp-
> >max_unmap_blocks);
> +
> switch (mode) {
>
> case SD_LBP_FULL:
> @@ -715,17 +723,17 @@ static void sd_config_discard(struct scsi_disk *sdkp,
> unsigned int mode)
> break;
>
> case SD_LBP_WS16:
> - max_blocks = min_not_zero(sdkp->max_ws_blocks,
> + max_blocks = min_not_zero(max_ws_blocks,
> (u32)SD_MAX_WS16_BLOCKS);
> break;
>
> case SD_LBP_WS10:
> - max_blocks = min_not_zero(sdkp->max_ws_blocks,
> + max_blocks = min_not_zero(max_ws_blocks,
> (u32)SD_MAX_WS10_BLOCKS);
> break;
>
> case SD_LBP_ZERO:
> - max_blocks = min_not_zero(sdkp->max_ws_blocks,
> + max_blocks = min_not_zero(max_ws_blocks,
> (u32)SD_MAX_WS10_BLOCKS);
> break;
> }
> --
> 2.1.0
