Re: [v3.7 Regression] [SCSI] sd: Implement support for WRITE SAME

From: Mike Snitzer
Date: Wed Dec 19 2012 - 14:57:57 EST

On Wed, Dec 19 2012 at 11:58am -0500,
Martin K. Petersen <martin.petersen@xxxxxxxxxx> wrote:

> >>>>> "Joseph" == Joseph Salisbury <joseph.salisbury@xxxxxxxxxxxxx> writes:
> Joseph> I captured the netconsole output from boot until I reproduced
> Joseph> the bug. The RIP points to kcryptd_crypt_write_io_submit() in
> Joseph> ~/drivers/md/dm-crypt.c. The output can be seen at:
> I'm thinking that dm-crypt should probably set max_write_same_sectors to
> 0. It doesn't really make much sense for a crypto driver to pass that
> command through.
> Mike, do you want to look into this?

Milan (cc'd) is more well-versed with dm-crypt. Though we likely need
to audit DM relative to WRITE SAME too (will do once I understand what
added safety/constraints are needed).

But do we know mount to somwhow be issuing WRITE SAME requests? Martin,
why is it you weren't able to reproduce (I haven't attempted yet)?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at