Re: [PATCH v2] SUNRPC: skip dead but not buried clients on PipeFS events

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25.04.2012 21:30, J. Bruce Fields написал:
On Fri, Apr 20, 2012 at 06:11:02PM +0400, Stanislav Kinsbursky wrote:
v2: atomic_inc_return() was replaced by atomic_inc_not_zero().

These clients can't be safely dereferenced if their counter in 0.
I'm pretty confused by how these notifiers work....

rpc_release_client decrements cl_count to zero temporarily, to have it
immediately re-incremented by rpc_free_auth.

So if we're called concurrently with rpc_release_client then it's sort
of random whether someone gets this callback.

Is that a problem?

Also, is this an existing bug?  (In which case Trond should take it
now.)

Sorry, I was mistaken in previous letter.
Yes, this is an existent bug.
I.e. without this patch notifier can dereference a client, which is actually dead already, but haven't deleted itself from the client's list. And then notifier will try to work with this client and even release it at the end.

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