Commit 67804145 authored Mar 28, 2017 by Fam Zheng Committed by Martin K. Petersen Apr 07, 2017

scsi: sd: Consider max_xfer_blocks if opt_xfer_blocks is unusable



If device reports a small max_xfer_blocks and a zero opt_xfer_blocks, we
end up using BLK_DEF_MAX_SECTORS, which is wrong and r/w of that size
may get error.

[mkp: tweaked to avoid setting rw_max twice and added typecast]

Cc: <stable@vger.kernel.org> # v4.4+
Fixes: ca369d51 ("block/sd: Fix device-imposed transfer length limits")
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

parent a3902ee9

drivers/scsi/sd.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2956,7 +2956,8 @@ static int sd_revalidate_disk(struct gendisk *disk)
		q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
		rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
		} else
		rw_max = BLK_DEF_MAX_SECTORS;
		rw_max = min_not_zero(logical_to_sectors(sdp, dev_max),
		(sector_t)BLK_DEF_MAX_SECTORS);

		/* Combine with controller limits */
		q->limits.max_sectors = min(rw_max, queue_max_hw_sectors(q));

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