Re: [PATCH] block: Don't allow illegal discard requests

From	Jan Kara <jack@suse.cz>
Newsgroups	linux.kernel
Subject	Re: [PATCH] block: Don't allow illegal discard requests
Date	2015-11-04 15:20 +0100
Message-ID	<qr74R-1xu-7@gated-at.bofh.it> (permalink)
References	<qr2oy-6Ys-7@gated-at.bofh.it> <qr4A2-8gn-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Wed 04-11-15 03:30:19, Christoph Hellwig wrote:
> On Wed, Nov 04, 2015 at 10:18:41AM +0100, Jan Kara wrote:
> > Currently blkdev_issue_discard() doesn't check that submitted discard
> > request matches granularity required by the underlying device.
> > Submitting such requests to the device can have unexpected consequences
> > (e.g. brd driver just discards more / less data depending on how exactly
> > the request is aligned). So test that submitted discard request has the
> > granularity required by the driver.
> 
> How is this going to work with stacked drivers?  I think brd needs to
> be fixed to take care of the granularity itself, just like we did for
> request based drivers.

So you mean that a stacked driver would split a discard request so that it
is no longer of the required granularity? OK, makes sense. I'll add the
check directly into brd itself.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH] block: Don't allow illegal discard requests Jan Kara <jack@suse.com> - 2015-11-04 10:20 +0100
  Re: [PATCH] block: Don't allow illegal discard requests kbuild test robot <lkp@intel.com> - 2015-11-04 11:50 +0100
  Re: [PATCH] block: Don't allow illegal discard requests kbuild test robot <lkp@intel.com> - 2015-11-04 11:50 +0100
  Re: [PATCH] block: Don't allow illegal discard requests kbuild test robot <lkp@intel.com> - 2015-11-04 12:00 +0100
  Re: [PATCH] block: Don't allow illegal discard requests Christoph Hellwig <hch@infradead.org> - 2015-11-04 12:40 +0100
    Re: [PATCH] block: Don't allow illegal discard requests Jan Kara <jack@suse.cz> - 2015-11-04 15:20 +0100

csiph-web