From: Bart Van Assche <bart.vanassche@sandisk.com>
To: <mchristi@redhat.com>, <linux-scsi@vger.kernel.org>,
<target-devel@vger.kernel.org>, <socketpair@gmail.com>
Cc: <stable@vger.kernel.org>
Subject: Re: [PATCH 1/2] scsi: fix max discard sectors calculation
Date: Mon, 16 May 2016 15:44:48 -0700 [thread overview]
Message-ID: <573A4D60.7080902@sandisk.com> (raw)
In-Reply-To: <1463424410-17196-2-git-send-email-mchristi@redhat.com>
On 05/16/2016 11:46 AM, mchristi@redhat.com wrote:
> logical_block_size and max_blocks are 32 bits, so we can
> overflow when trying to convert SCSI device blocks to linux
> block layer sectors.
>
> Signed-off-by: Mike Christie <mchristi@redhat.com>
> Cc: stable@vger.kernel.org
>
> ---
> drivers/scsi/sd.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index f52b74c..1668e1d 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -690,7 +690,8 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
> - blk_queue_max_discard_sectors(q, max_blocks * (logical_block_size >> 9));
> + blk_queue_max_discard_sectors(q, (u64)max_blocks *
> + (logical_block_size >> 9));
Hello Mike,
As far as I can see max_blocks <= 0xffff (SD_MAX_WS10_BLOCKS) and 512 <=
logical_block_size <= 4096. How can max_blocks * (logical_block_size >>
9) be too large for a 32 bit integer?
Thanks,
Bart.
next prev parent reply other threads:[~2016-05-16 22:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1463424410-17196-1-git-send-email-mchristi@redhat.com>
2016-05-16 18:46 ` [PATCH 1/2] scsi: fix max discard sectors calculation mchristi
2016-05-16 22:44 ` Bart Van Assche [this message]
2016-05-17 3:46 ` Mike Christie
2016-05-16 18:46 ` [PATCH 2/2] target: " mchristi
2016-05-16 18:57 ` Bart Van Assche
2016-05-16 19:00 ` Mike Christie
2016-05-16 19:02 ` Martin K. Petersen
2016-05-17 18:16 ` Bart Van Assche
2016-05-17 21:49 ` Mike Christie
2016-05-18 16:56 ` Bart Van Assche
2016-05-18 17:17 ` Mike Christie
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