Messages in this thread | | | Date | Tue, 13 Aug 2019 15:00:22 -0300 | From | Jason Gunthorpe <> | Subject | Re: [RFC PATCH v2 16/19] RDMA/uverbs: Add back pointer to system file object |
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On Tue, Aug 13, 2019 at 10:41:42AM -0700, Ira Weiny wrote:
> And I was pretty sure uverbs_destroy_ufile_hw() would take care of (or ensure > that some other thread is) destroying all the MR's we have associated with this > FD.
fd's can't be revoked, so destroy_ufile_hw() can't touch them. It deletes any underlying HW resources, but the FD persists.
> > This is why having a back pointer like this is so ugly, it creates a > > reference counting cycle > > Yep... I worked through this... and it was giving me fits... > > Anyway, the struct file is the only object in the core which was reasonable to > store this information in since that is what is passed around to other > processes...
It could be passed down in the uattr_bundle, once you are in file operations handle the file is guarenteed to exist, and we've now arranged things so the uattr_bundle flows into the umem, as umems can only be established under a system call.
Jason
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