[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v5] Fixes to Xen pciback for 3.17.
On Mon, Jul 14, 2014 at 10:40:42AM -0700, Greg KH wrote: > On Mon, Jul 14, 2014 at 12:18:50PM -0400, Konrad Rzeszutek Wilk wrote: > > Greg: goto GHK > > > > This is v5 version of patches to fix some issues in Xen PCIback. > > > > One of the issues Xen PCI back has that patch: > > > > is fixing is that a deadlock can happen if the PCI device is > > assigned to a guest and we try to 'unbind' it from Xen 'pciback' driver. > > The issue is rather simple - the SysFS mechanism for the 'unbind' path > > takes a device lock and the code in Xen PCI uses the pci_reset_function > > which also takes the same lock. Solution is to use the lock-less version > > and mandate that callers of said function in Xen pciback take the lock. > > Easy enough. > > > > GHK: > > To guard against this happening in the future we also add an assert in the > > form of lockdep assertion. That is OK except that it looks ugly as we take > > it straight from the 'struct device' instead of using an appropriate macro. > > See: > > > > + lockdep_assert_held(&dev->dev.mutex); > > > > (in [PATCH v5 2/6] xen/pciback: Don't deadlock when unbinding). > > > > The patch: [PATCH v5 3/6] driver core: Provide an wrapper around the mutex > > to do. > > > > introduces a nice wrapper so it is bit cleaner. Greg, if you are OK with > > it could you kindly Ack it as I would prefer to put this patchset > > via the Xen tree. It would look now as: > > > > - lockdep_assert_held(&dev->dev.mutex); > > + device_lock_assert(&dev->dev); > > > > I can also squash it in "[PATCH v5 2/6] xen/pciback: Don't deadlock when > > unbinding." but since that one is going through the stable tree I wasn't > > sure whether you (Greg KH) would be OK with that. > > You have my ack now, and feel free to squash it into patch 2/6 if you > want, I don't mind having that in the stable trees. Fantastic! Thank you. > > thanks, > > greg k-h _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |