On Wed, Jul 25, 2018 at 09:40:09PM -0600, Jason Gunthorpe wrote: > From: Jason Gunthorpe <jgg@xxxxxxxxxxxx> > > The implementation of disassociation has had a long standing and serious > flaw, userspace cannot recover from it. Since all commands fail in the > kernel with EIO an application is unable to call ibv_destroy_XX, which > means the app cannot cleanup the memory. Ultimately this makes the feature > useless for a continually available system. > > A simple solution of having userspace understand that EIO means the kernel > is gone unfortunately does not work for several of the objects (such as CQ > and QP) that return data necessary for userspace to complete destruction > in a multi-threaded environment. > > Thus, this series completes the re-arrangement of the core code to permit > an uboject to exist on the IDR list without an associated HW object. When > this happens the destroy method can work as normal even after > disassociation. > > Overall this approach makes the code generally more uniform and typical as > several of the locking flows are made more explicit. We no longer rely on > an implicit SRCU based check of ib_dev in the command caller for > correctness, everything is contained within some kind of lock. > > This series does not remove the last roadblock for ioctl methods as the > ioctl methods can rely on data held inside the driver module that > registered the device. A followup series will be required to disconnect > the ioctl specs from the device data upon removal. > > Jason Gunthorpe (11): > IB/uverbs: Remove rdma_explicit_destroy() from the ioctl methods > IB/uverbs: Make the write path destroy methods use the same flow as > ioctl > IB/uverbs: Consolidate uobject destruction > IB/uverbs: Convert 'bool exclusive' into an enum > IB/uverbs: Allow RDMA_REMOVE_DESTROY to work concurrently with > disassociate > IB/uverbs: Allow uobject allocation to work concurrently with > disassociate > IB/uverbs: Lower the test for ongoing disassociation > IB/uverbs: Do not pass struct ib_device to the write based methods > IB/uverbs: Do not pass struct ib_device to the ioctl methods > IB/uverbs: Do not block disassociate during write() > IB/uverbs: Allow all DESTROY commands to succeed after disassociate Applied to for-next Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
