Re: [PATCH] Use the correct size to set block max sectors
From: Joe Perches
Date: Thu May 26 2016 - 21:36:05 EST
dOn Thu, 2016-05-26 at 17:08 -0700, Long Li wrote:
> The block sector size should be in unit of 512 bytes, not in bytes.
Thanks. The patch subject should use something like:
[PATCH] sd: Use the correct size to set block max sectors
to show what subsystem is being modified.
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
[]
> @@ -2862,9 +2862,11 @@ static int sd_revalidate_disk(struct gendisk *disk)
> if (sdkp->opt_xfer_blocks &&
> sdkp->opt_xfer_blocks <= dev_max &&
> sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
> - sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_SIZE)
> - rw_max = q->limits.io_opt =
> + sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_SIZE) {
> + q->limits.io_opt =
> sdkp->opt_xfer_blocks * sdp->sector_size;
> + rw_max = (q->limits.io_opt >> 9);
> + }
> else
> rw_max = BLK_DEF_MAX_SECTORS;
And style trivia: it'd be more kernel style consistent as:
if (...
sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_SIZE) {
q->limits.io_opt = sdkp->opt_xfer_blocks * sdp->sector_size;
rw_max = q->limits.io_opt >> 9;
} else {
rw_max = BLK_DEF_MAX_SECTORS;
}
ie: no parentheses necessary around the shifted value and
braces around both arms.