On Mon, 2014-06-02 at 15:11 -0400, Martin K. Petersen wrote: > Until now the per-command transfer length has exclusively been gated by > the max_sectors parameter in the scsi_host template. Given that the size > of this parameter has been bumped to an unsigned int we have to be > careful not to exceed the target device's capabilities. > > If the if the device specifies a Maximum Transfer Length in the Block > Limits VPD we'll use that value. Otherwise we'll use 0xffffffff for > devices that have use_16_for_rw set and 0xffff for the rest. We then > combine the chosen disk limit with max_sectors in the host template. The > smaller of the two will be used to set the max_hw_sectors queue limit. > > Signed-off-by: Martin K. Petersen <[email protected]> > > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c > index 321faf603035..56018f37518d 100644 > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -2228,7 +2228,11 @@ got_data: > } > } > > - sdp->use_16_for_rw = (sdkp->capacity > 0xffffffff); > + if (sdkp->capacity > 0xffffffff) { > + sdp->use_16_for_rw = 1; > + sdkp->max_xfer_blocks = SD_MAX_XFER_BLOCKS; > + } else > + sdkp->max_xfer_blocks = SD_DEF_XFER_BLOCKS; > > /* Rescale capacity to 512-byte units */ > if (sector_size == 4096) > @@ -2540,6 +2544,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp) > { > unsigned int sector_sz = sdkp->device->sector_size; > const int vpd_len = 64; > + u32 max_xfer_length; > unsigned char *buffer = kmalloc(vpd_len, GFP_KERNEL); > > if (!buffer || > @@ -2547,6 +2552,10 @@ static void sd_read_block_limits(struct scsi_disk > *sdkp) > scsi_get_vpd_page(sdkp->device, 0xb0, buffer, vpd_len)) > goto out; > > + max_xfer_length = get_unaligned_be32(&buffer[8]); > + if (max_xfer_length) > + sdkp->max_xfer_blocks = max_xfer_length; > + > blk_queue_io_min(sdkp->disk->queue, > get_unaligned_be16(&buffer[6]) * sector_sz); > blk_queue_io_opt(sdkp->disk->queue, > @@ -2702,6 +2711,7 @@ static int sd_revalidate_disk(struct gendisk *disk) > struct scsi_device *sdp = sdkp->device; > unsigned char *buffer; > unsigned flush = 0; > + unsigned int max_xfer; > > SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, > "sd_revalidate_disk\n")); > @@ -2755,6 +2765,10 @@ static int sd_revalidate_disk(struct gendisk *disk) > > blk_queue_flush(sdkp->disk->queue, flush); > > + max_xfer = min_not_zero((unsigned int)sdp->host->max_sectors, > + (unsigned int)sdkp->max_xfer_blocks); > + max_xfer <<= ilog2(sdp->sector_size) - 9; > + blk_queue_max_hw_sectors(sdkp->disk->queue, max_xfer); > set_capacity(disk, sdkp->capacity); > sd_config_write_same(sdkp); > kfree(buffer); > diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h > index 620871efbf0a..4c3ab8377fd3 100644 > --- a/drivers/scsi/sd.h > +++ b/drivers/scsi/sd.h > @@ -44,6 +44,8 @@ enum { > }; > > enum { > + SD_DEF_XFER_BLOCKS = 0xffff, > + SD_MAX_XFER_BLOCKS = 0xffffffff, > SD_MAX_WS10_BLOCKS = 0xffff, > SD_MAX_WS16_BLOCKS = 0x7fffff, > }; > @@ -64,6 +66,7 @@ struct scsi_disk { > struct gendisk *disk; > atomic_t openers; > sector_t capacity; /* size in 512-byte sectors */ > + u32 max_xfer_blocks; > u32 max_ws_blocks; > u32 max_unmap_blocks; > u32 unmap_granularity; > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html
Looks good. Reviewed-by: Ewan D. Milne <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
