| Message ID | 1385642889-11513-1-git-send-email-wei.liu2@citrix.com |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 2013-11-28 at 12:48 +0000, Wei Liu wrote: > With the introduction of "xen-netback: Don't destroy the netdev until > the vif is shut down" (upstream commit id 279f438e36), vif disconnect > and free are separated. However in the backported verion reference > counting code was not correctly modified, and the reset of vif->tx_irq > was lost. If frontend goes through vif life cycle more than once the > reference counting is skewed. > > This patch adds back the missing tx_irq reset line. It also moves > several lines of the reference counting code to vif_free, so the moved > code corresponds to the counterpart in vif_alloc, thus the reference > counting is balanced. Is this a requirement of the bugfix or just to make reasoning about things easier? > 3.12 and onward versions are not affected by this bug, because reference > counting code was removed due to the introduction of 1:1 model. > > This pacth should be backported to all stable verions which are lower > than 3.12 and have 279f438e36. > > Reported-and-tested-by: Tomasz Wroblewski <tomasz.wroblewski@citrix.com> > Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> > Cc: Konrad Wilk <konrad.wilk@oracle.com> > Cc: David Vrabel <david.vrabel@citrix.com> > --- > drivers/net/xen-netback/interface.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c > index d28324a..342d4e5 100644 > --- a/drivers/net/xen-netback/interface.c > +++ b/drivers/net/xen-netback/interface.c > @@ -418,9 +418,6 @@ void xenvif_disconnect(struct xenvif *vif) > if (netif_carrier_ok(vif->dev)) > xenvif_carrier_off(vif); > > - atomic_dec(&vif->refcnt); > - wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); > - > if (vif->tx_irq) { > if (vif->tx_irq == vif->rx_irq) > unbind_from_irqhandler(vif->tx_irq, vif); > @@ -428,6 +425,7 @@ void xenvif_disconnect(struct xenvif *vif) > unbind_from_irqhandler(vif->tx_irq, vif); > unbind_from_irqhandler(vif->rx_irq, vif); > } > + vif->tx_irq = 0; > } > > xen_netbk_unmap_frontend_rings(vif); > @@ -435,6 +433,9 @@ void xenvif_disconnect(struct xenvif *vif) > > void xenvif_free(struct xenvif *vif) > { > + atomic_dec(&vif->refcnt); > + wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); > + > unregister_netdev(vif->dev); > > free_netdev(vif->dev); -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Nov 28, 2013 at 01:08:53PM +0000, Ian Campbell wrote: > On Thu, 2013-11-28 at 12:48 +0000, Wei Liu wrote: > > With the introduction of "xen-netback: Don't destroy the netdev until > > the vif is shut down" (upstream commit id 279f438e36), vif disconnect > > and free are separated. However in the backported verion reference > > counting code was not correctly modified, and the reset of vif->tx_irq > > was lost. If frontend goes through vif life cycle more than once the > > reference counting is skewed. > > > > This patch adds back the missing tx_irq reset line. It also moves > > several lines of the reference counting code to vif_free, so the moved > > code corresponds to the counterpart in vif_alloc, thus the reference > > counting is balanced. > > Is this a requirement of the bugfix or just to make reasoning about > things easier? > The latter. Wei. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Wei Liu <wei.liu2@citrix.com> Date: Thu, 28 Nov 2013 13:13:46 +0000 > On Thu, Nov 28, 2013 at 01:08:53PM +0000, Ian Campbell wrote: >> On Thu, 2013-11-28 at 12:48 +0000, Wei Liu wrote: >> > With the introduction of "xen-netback: Don't destroy the netdev until >> > the vif is shut down" (upstream commit id 279f438e36), vif disconnect >> > and free are separated. However in the backported verion reference >> > counting code was not correctly modified, and the reset of vif->tx_irq >> > was lost. If frontend goes through vif life cycle more than once the >> > reference counting is skewed. >> > >> > This patch adds back the missing tx_irq reset line. It also moves >> > several lines of the reference counting code to vif_free, so the moved >> > code corresponds to the counterpart in vif_alloc, thus the reference >> > counting is balanced. >> >> Is this a requirement of the bugfix or just to make reasoning about >> things easier? >> > > The latter. I've queued this up for -stable, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Nov 28, 2013 at 12:48:09PM +0000, Wei Liu wrote: > With the introduction of "xen-netback: Don't destroy the netdev until > the vif is shut down" (upstream commit id 279f438e36), vif disconnect > and free are separated. However in the backported verion reference > counting code was not correctly modified, and the reset of vif->tx_irq > was lost. If frontend goes through vif life cycle more than once the > reference counting is skewed. > > This patch adds back the missing tx_irq reset line. It also moves > several lines of the reference counting code to vif_free, so the moved > code corresponds to the counterpart in vif_alloc, thus the reference > counting is balanced. > > 3.12 and onward versions are not affected by this bug, because reference > counting code was removed due to the introduction of 1:1 model. > > This pacth should be backported to all stable verions which are lower > than 3.12 and have 279f438e36. What stable versions are those? 279f438e36 showed up in 3.12-rc2, and was not marked for stable inclusion, so what kernel would end up needing this patch? confused, greg k-h -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Nov 30, 2013 at 08:48:35PM -0800, Greg KH wrote: > On Thu, Nov 28, 2013 at 12:48:09PM +0000, Wei Liu wrote: > > With the introduction of "xen-netback: Don't destroy the netdev until > > the vif is shut down" (upstream commit id 279f438e36), vif disconnect > > and free are separated. However in the backported verion reference > > counting code was not correctly modified, and the reset of vif->tx_irq > > was lost. If frontend goes through vif life cycle more than once the > > reference counting is skewed. > > > > This patch adds back the missing tx_irq reset line. It also moves > > several lines of the reference counting code to vif_free, so the moved > > code corresponds to the counterpart in vif_alloc, thus the reference > > counting is balanced. > > > > 3.12 and onward versions are not affected by this bug, because reference > > counting code was removed due to the introduction of 1:1 model. > > > > This pacth should be backported to all stable verions which are lower > > than 3.12 and have 279f438e36. > > What stable versions are those? 279f438e36 showed up in 3.12-rc2, and > was not marked for stable inclusion, so what kernel would end up needing > this patch? > Greg, 279f438e36 was backported to at least stable branches 3.11.y: <13826815042174@kroah.org> commit id f495ddc46 3.10.y: <13828112161592@kroah.com> commit id a4626bf64 So at least those two need this patch. And I remeber 3.8.y.z extended stable branch maintained by Kamal also has the said commit. > confused, > Sorry, I should've stated cleared all versions. BTW the above patch applies to 3.11.y. I can provide backports to 3.10.y as well, if necessary. Wei. > greg k-h -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Dec 02, 2013 at 12:01:34PM +0000, Wei Liu wrote: > On Sat, Nov 30, 2013 at 08:48:35PM -0800, Greg KH wrote: > > On Thu, Nov 28, 2013 at 12:48:09PM +0000, Wei Liu wrote: > > > With the introduction of "xen-netback: Don't destroy the netdev until > > > the vif is shut down" (upstream commit id 279f438e36), vif disconnect > > > and free are separated. However in the backported verion reference > > > counting code was not correctly modified, and the reset of vif->tx_irq > > > was lost. If frontend goes through vif life cycle more than once the > > > reference counting is skewed. > > > > > > This patch adds back the missing tx_irq reset line. It also moves > > > several lines of the reference counting code to vif_free, so the moved > > > code corresponds to the counterpart in vif_alloc, thus the reference > > > counting is balanced. > > > > > > 3.12 and onward versions are not affected by this bug, because reference > > > counting code was removed due to the introduction of 1:1 model. > > > > > > This pacth should be backported to all stable verions which are lower > > > than 3.12 and have 279f438e36. > > > > What stable versions are those? 279f438e36 showed up in 3.12-rc2, and > > was not marked for stable inclusion, so what kernel would end up needing > > this patch? > > > > Greg, > > 279f438e36 was backported to at least stable branches > > 3.11.y: <13826815042174@kroah.org> commit id f495ddc46 > 3.10.y: <13828112161592@kroah.com> commit id a4626bf64 > > So at least those two need this patch. > > And I remeber 3.8.y.z extended stable branch maintained by Kamal also > has the said commit. > > > confused, > > > > Sorry, I should've stated cleared all versions. > > BTW the above patch applies to 3.11.y. I can provide backports to 3.10.y > as well, if necessary. As 3.11.y is now dead, there's not much I can do with that one, but I could use a backport for 3.10.y, as this patch does not apply there, thanks. greg k-h -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Nov 28, 2013 at 12:48:09PM +0000, Wei Liu wrote: > With the introduction of "xen-netback: Don't destroy the netdev until > the vif is shut down" (upstream commit id 279f438e36), vif disconnect > and free are separated. However in the backported verion reference > counting code was not correctly modified, and the reset of vif->tx_irq > was lost. If frontend goes through vif life cycle more than once the > reference counting is skewed. > > This patch adds back the missing tx_irq reset line. It also moves > several lines of the reference counting code to vif_free, so the moved > code corresponds to the counterpart in vif_alloc, thus the reference > counting is balanced. > > 3.12 and onward versions are not affected by this bug, because reference > counting code was removed due to the introduction of 1:1 model. > > This pacth should be backported to all stable verions which are lower > than 3.12 and have 279f438e36. For some reason, I missed this patch. I'm queuing it now for the 3.11 kernel. Thank you! Cheers, -- Luis > > Reported-and-tested-by: Tomasz Wroblewski <tomasz.wroblewski@citrix.com> > Signed-off-by: Wei Liu <wei.liu2@citrix.com> > Cc: Ian Campbell <ian.campbell@citrix.com> > Cc: Konrad Wilk <konrad.wilk@oracle.com> > Cc: David Vrabel <david.vrabel@citrix.com> > --- > drivers/net/xen-netback/interface.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c > index d28324a..342d4e5 100644 > --- a/drivers/net/xen-netback/interface.c > +++ b/drivers/net/xen-netback/interface.c > @@ -418,9 +418,6 @@ void xenvif_disconnect(struct xenvif *vif) > if (netif_carrier_ok(vif->dev)) > xenvif_carrier_off(vif); > > - atomic_dec(&vif->refcnt); > - wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); > - > if (vif->tx_irq) { > if (vif->tx_irq == vif->rx_irq) > unbind_from_irqhandler(vif->tx_irq, vif); > @@ -428,6 +425,7 @@ void xenvif_disconnect(struct xenvif *vif) > unbind_from_irqhandler(vif->tx_irq, vif); > unbind_from_irqhandler(vif->rx_irq, vif); > } > + vif->tx_irq = 0; > } > > xen_netbk_unmap_frontend_rings(vif); > @@ -435,6 +433,9 @@ void xenvif_disconnect(struct xenvif *vif) > > void xenvif_free(struct xenvif *vif) > { > + atomic_dec(&vif->refcnt); > + wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); > + > unregister_netdev(vif->dev); > > free_netdev(vif->dev); > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index d28324a..342d4e5 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -418,9 +418,6 @@ void xenvif_disconnect(struct xenvif *vif) if (netif_carrier_ok(vif->dev)) xenvif_carrier_off(vif); - atomic_dec(&vif->refcnt); - wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); - if (vif->tx_irq) { if (vif->tx_irq == vif->rx_irq) unbind_from_irqhandler(vif->tx_irq, vif); @@ -428,6 +425,7 @@ void xenvif_disconnect(struct xenvif *vif) unbind_from_irqhandler(vif->tx_irq, vif); unbind_from_irqhandler(vif->rx_irq, vif); } + vif->tx_irq = 0; } xen_netbk_unmap_frontend_rings(vif); @@ -435,6 +433,9 @@ void xenvif_disconnect(struct xenvif *vif) void xenvif_free(struct xenvif *vif) { + atomic_dec(&vif->refcnt); + wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); + unregister_netdev(vif->dev); free_netdev(vif->dev);
With the introduction of "xen-netback: Don't destroy the netdev until the vif is shut down" (upstream commit id 279f438e36), vif disconnect and free are separated. However in the backported verion reference counting code was not correctly modified, and the reset of vif->tx_irq was lost. If frontend goes through vif life cycle more than once the reference counting is skewed. This patch adds back the missing tx_irq reset line. It also moves several lines of the reference counting code to vif_free, so the moved code corresponds to the counterpart in vif_alloc, thus the reference counting is balanced. 3.12 and onward versions are not affected by this bug, because reference counting code was removed due to the introduction of 1:1 model. This pacth should be backported to all stable verions which are lower than 3.12 and have 279f438e36. Reported-and-tested-by: Tomasz Wroblewski <tomasz.wroblewski@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> --- drivers/net/xen-netback/interface.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)