On Thu, Jan 29, 2015 at 1:54 PM, Brian King <brking@xxxxxxxxxxxxxxxxxx> wrote: > > The following patch fixes an issue observed with 4k sector disks > where the max_hw_sectors attribute was getting set too large in > sd_revalidate_disk. Since sdkp->max_xfer_blocks is in units > of SCSI logical blocks and queue_max_hw_sectors is in units of > 512 byte blocks, on a 4k sector disk, every time we went through > sd_revalidate_disk, we were taking the current value of > queue_max_hw_sectors and increasing it by a factor of 8. Fix > this by only shifting sdkp->max_xfer_blocks. > > Cc: stable<stable@xxxxxxxxxxxxxxx> > Signed-off-by: Brian King <brking@xxxxxxxxxxxxxxxxxx> > --- > > drivers/scsi/sd.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff -puN drivers/scsi/sd.c~sd_revalidate_4k drivers/scsi/sd.c > --- linux/drivers/scsi/sd.c~sd_revalidate_4k 2015-01-29 14:44:23.316171187 -0600 > +++ linux-bjking1/drivers/scsi/sd.c 2015-01-29 14:51:05.846126392 -0600 > @@ -2800,9 +2800,11 @@ static int sd_revalidate_disk(struct gen > */ > sd_set_flush_flag(sdkp); > > - max_xfer = min_not_zero(queue_max_hw_sectors(sdkp->disk->queue), > - sdkp->max_xfer_blocks); > + max_xfer = sdkp->max_xfer_blocks; > max_xfer <<= ilog2(sdp->sector_size) - 9; > + > + max_xfer = min_not_zero(queue_max_hw_sectors(sdkp->disk->queue), > + max_xfer); > blk_queue_max_hw_sectors(sdkp->disk->queue, max_xfer); > set_capacity(disk, sdkp->capacity); > sd_config_write_same(sdkp); Heh, nice find. Tested-by: Venkatesh Srinivas <venkateshs@xxxxxxxxxx> -- vs; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html