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From: David Vrabel <david.vrabel@citrix.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com,
	Konrad Rzeszutek Wilk <konrad@kernel.org>,
	stable@vger.kernel.org
Subject: Re: [Xen-devel] [PATCH 3/3] xen/blkback: Check for insane amounts of request on the ring.
Date: Mon, 28 Jan 2013 11:38:50 +0000	[thread overview]
Message-ID: <5106634A.2000308@citrix.com> (raw)
In-Reply-To: <20130125184323.GC1384@phenom.dumpdata.com>

On 25/01/13 18:43, Konrad Rzeszutek Wilk wrote:
> 
> Check that the ring does not have an insane amount of requests
> (more than there could fit on the ring).
[...]
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
[...]
> @@ -415,8 +415,12 @@ int xen_blkif_schedule(void *arg)
>  		blkif->waiting_reqs = 0;
>  		smp_mb(); /* clear flag *before* checking for work */
>  
> -		if (do_block_io_op(blkif))
> +		rc = do_block_io_op(blkif);
> +		if (rc > 0)
>  			blkif->waiting_reqs = 1;
> +		if (rc == -EACCES)
> +			wait_event_interruptible(blkif->shutdown_wq,
> +						 kthread_should_stop());

So if this happens then the backend silently stops processing any
further requests?  I think it should print an error and disconnect from
the front end.

David

  parent reply	other threads:[~2013-01-28 11:38 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-25 17:32 [PATCH] block backend fixes for v3.8 (and stable) v1 Konrad Rzeszutek Wilk
2013-01-25 17:32 ` [PATCH 1/3] xen/blkback: Don't trust the handle from the frontend Konrad Rzeszutek Wilk
2013-01-28 11:09   ` Jan Beulich
2013-01-25 17:32 ` [PATCH 2/3] xen/ring: Add a new macro to detect whether there is an overflow in requests and response Konrad Rzeszutek Wilk
2013-01-25 17:45   ` Roger Pau Monné
2013-01-25 18:29     ` [Xen-devel] " Konrad Rzeszutek Wilk
2013-01-25 18:41     ` Konrad Rzeszutek Wilk
2013-01-25 18:41   ` Konrad Rzeszutek Wilk
2013-01-25 17:32 ` [PATCH 3/3] xen/blkback: Check for insane amounts of request on the ring Konrad Rzeszutek Wilk
2013-01-25 18:43   ` Konrad Rzeszutek Wilk
2013-01-28 11:07     ` Jan Beulich
2013-01-28 11:38     ` David Vrabel [this message]
2013-01-28 15:44       ` [Xen-devel] " Konrad Rzeszutek Wilk
2013-01-28 16:03         ` David Vrabel
2013-01-28 16:13           ` Konrad Rzeszutek Wilk
     [not found]     ` <51066A1202000078000BA020@nat28.tlf.novell.com>
2013-01-28 15:42       ` Konrad Rzeszutek Wilk
     [not found]       ` <20130128154231.GF4838@konrad-lan.dumpdata.com>
2013-01-28 16:18         ` Jan Beulich
     [not found]         ` <5106B30302000078000BA2A2@nat28.tlf.novell.com>
2013-01-28 16:47           ` Konrad Rzeszutek Wilk

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