[PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Chen Gang]

  if call xen_vbd_translate failed, the preq.dev will be not initialized.
  so use blkif->vbd.pdevice instead (still better to print relative info).

Signed-off-by: Chen Gang <gang.chen@asianux.com>
---
 drivers/block/xen-blkback/blkback.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index de1f319..6d1cc3d 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -904,7 +904,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 		pr_debug(DRV_PFX "access denied: %s of [%llu,%llu] on dev=%04x\n",
 			 operation == READ ? "read" : "write",
 			 preq.sector_number,
-			 preq.sector_number + preq.nr_sects, preq.dev);
+			 preq.sector_number + preq.nr_sects,
+			 blkif->vbd.pdevice);
 		goto fail_response;
 	}
 
-- 
1.7.7.6

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Jan Beulich]

>>> On 27.02.13 at 05:52, Chen Gang <gang.chen@asianux.com> wrote:

>   if call xen_vbd_translate failed, the preq.dev will be not initialized.
>   so use blkif->vbd.pdevice instead (still better to print relative info).
> 
> Signed-off-by: Chen Gang <gang.chen@asianux.com>

Acked-by: Jan Beulich <jbeulich@suse.com>

> ---
>  drivers/block/xen-blkback/blkback.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/block/xen-blkback/blkback.c 
> b/drivers/block/xen-blkback/blkback.c
> index de1f319..6d1cc3d 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -904,7 +904,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
>  		pr_debug(DRV_PFX "access denied: %s of [%llu,%llu] on dev=%04x\n",
>  			 operation == READ ? "read" : "write",
>  			 preq.sector_number,
> -			 preq.sector_number + preq.nr_sects, preq.dev);
> +			 preq.sector_number + preq.nr_sects,
> +			 blkif->vbd.pdevice);
>  		goto fail_response;
>  	}
>  
> -- 
> 1.7.7.6

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Roger Pau Monné]

On 27/02/13 05:52, Chen Gang wrote:
> 
>   if call xen_vbd_translate failed, the preq.dev will be not initialized.
>   so use blkif->vbd.pdevice instead (still better to print relative info).

preq.dev is initialized a a couple of lines prior to calling
xen_vbd_translate:

preq.dev           = req->u.rw.handle;

> Signed-off-by: Chen Gang <gang.chen@asianux.com>
> ---
>  drivers/block/xen-blkback/blkback.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
> index de1f319..6d1cc3d 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -904,7 +904,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
>  		pr_debug(DRV_PFX "access denied: %s of [%llu,%llu] on dev=%04x\n",
>  			 operation == READ ? "read" : "write",
>  			 preq.sector_number,
> -			 preq.sector_number + preq.nr_sects, preq.dev);
> +			 preq.sector_number + preq.nr_sects,
> +			 blkif->vbd.pdevice);
>  		goto fail_response;
>  	}
>  
> 

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Jan Beulich]

>>> On 27.02.13 at 05:52, Chen Gang <gang.chen@asianux.com> wrote:
>   if call xen_vbd_translate failed, the preq.dev will be not initialized.
>   so use blkif->vbd.pdevice instead (still better to print relative info).

You also could have mentioned that even before commit 
01c681d4c70d64cb72142a2823f27c4146a02e63 the value printed
here was bogus, as it was the guest provided value from
req->u.rw.handle rather than the actual device.

Jan

> Signed-off-by: Chen Gang <gang.chen@asianux.com>
> ---
>  drivers/block/xen-blkback/blkback.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/block/xen-blkback/blkback.c 
> b/drivers/block/xen-blkback/blkback.c
> index de1f319..6d1cc3d 100644
> --- a/drivers/block/xen-blkback/blkback.c
> +++ b/drivers/block/xen-blkback/blkback.c
> @@ -904,7 +904,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
>  		pr_debug(DRV_PFX "access denied: %s of [%llu,%llu] on dev=%04x\n",
>  			 operation == READ ? "read" : "write",
>  			 preq.sector_number,
> -			 preq.sector_number + preq.nr_sects, preq.dev);
> +			 preq.sector_number + preq.nr_sects,
> +			 blkif->vbd.pdevice);
>  		goto fail_response;
>  	}
>  
> -- 
> 1.7.7.6

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Jan Beulich]

>>> On 27.02.13 at 10:50, Roger Pau Monné<roger.pau@citrix.com> wrote:
> On 27/02/13 05:52, Chen Gang wrote:
>> 
>>   if call xen_vbd_translate failed, the preq.dev will be not initialized.
>>   so use blkif->vbd.pdevice instead (still better to print relative info).
> 
> preq.dev is initialized a a couple of lines prior to calling
> xen_vbd_translate:
> 
> preq.dev           = req->u.rw.handle;

Not anymore after 01c681d4c70d64cb72142a2823f27c4146a02e63
(in Konrad's tree).

Jan

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Chen Gang]

于 2013年02月27日 17:57, Jan Beulich 写道:
> You also could have mentioned that even before commit 
> 01c681d4c70d64cb72142a2823f27c4146a02e63 the value printed
> here was bogus, as it was the guest provided value from
> req->u.rw.handle rather than the actual device.

  pardon ?

  I guess what you said is :
    my patch seems ok, but the comments need improving.
    need add "additional info" in comments:
      "before commit 01c681d4c70d64cb72142a2823f27c4146a02e63
       the value printed here was bogus, as it was the guest
       provided value from req->u.rw.handle rather than the
       actual device".

  is it correct ?

  thanks.

-- 
Chen Gang

Asianux Corporation

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Jan Beulich]

>>> On 27.02.13 at 11:38, Chen Gang <gang.chen@asianux.com> wrote:
> 于 2013年02月27日 17:57, Jan Beulich 写道:
>> You also could have mentioned that even before commit 
>> 01c681d4c70d64cb72142a2823f27c4146a02e63 the value printed
>> here was bogus, as it was the guest provided value from
>> req->u.rw.handle rather than the actual device.
> 
>   pardon ?
> 
>   I guess what you said is :
>     my patch seems ok, but the comments need improving.
>     need add "additional info" in comments:
>       "before commit 01c681d4c70d64cb72142a2823f27c4146a02e63
>        the value printed here was bogus, as it was the guest
>        provided value from req->u.rw.handle rather than the
>        actual device".
> 
>   is it correct ?

Yes (and you might have missed the ACK that I had already sent
before this reply - that mail got bounced for your address).

Jan

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Konrad Rzeszutek Wilk]

On Wed, Feb 27, 2013 at 10:45:35AM +0000, Jan Beulich wrote:
> >>> On 27.02.13 at 11:38, Chen Gang <gang.chen@asianux.com> wrote:
> > 于 2013年02月27日 17:57, Jan Beulich 写道:
> >> You also could have mentioned that even before commit 
> >> 01c681d4c70d64cb72142a2823f27c4146a02e63 the value printed
> >> here was bogus, as it was the guest provided value from
> >> req->u.rw.handle rather than the actual device.
> > 
> >   pardon ?
> > 
> >   I guess what you said is :
> >     my patch seems ok, but the comments need improving.
> >     need add "additional info" in comments:
> >       "before commit 01c681d4c70d64cb72142a2823f27c4146a02e63
> >        the value printed here was bogus, as it was the guest
> >        provided value from req->u.rw.handle rather than the
> >        actual device".
> > 
> >   is it correct ?
> 
> Yes (and you might have missed the ACK that I had already sent
> before this reply - that mail got bounced for your address).

Yup. Chen, could you respin the patch with the extra comment and
the Ack from Jan please?

Thank you!
> 
> Jan

Re: [PATCH] drivers/block/xen-blkback: preq.dev is used without initialized

[Chen Gang]

于 2013年02月27日 23:40, Konrad Rzeszutek Wilk 写道:
> On Wed, Feb 27, 2013 at 10:45:35AM +0000, Jan Beulich wrote:
>> > 
>> > Yes (and you might have missed the ACK that I had already sent
>> > before this reply - that mail got bounced for your address).
> Yup. Chen, could you respin the patch with the extra comment and
> the Ack from Jan please?

  ok, I will send patch v2.

  :-)

-- 
Chen Gang

Asianux Corporation