Messages in this thread |  | | From | "Michael Kelley (LINUX)" <> | Subject | RE: [PATCH 4/6] Drivers: hv: vmbus: Introduce vmbus_request_addr_match() | Date | Mon, 11 Apr 2022 02:31:59 +0000 |
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From: Andrea Parri <parri.andrea@gmail.com> Sent: Friday, April 8, 2022 1:38 PM > > > > > In the case where a specific match is required, and trans_id is > > > > valid but the addr's do not match, it looks like this function will > > > > return the addr that didn't match, without removing the entry. > > > > > > Yes, that is consistent with the description on vmbus_request_addr_match(): > > > > > > Returns the memory address stored at @trans_id, or VMBUS_RQST_ERROR if > > > @trans_id is not contained in the requestor. > > > > > > > > > > Shouldn't it return VMBUS_RQST_ERROR in that case? > > > > > > Can certainly be done, although I'm not sure to follow your concerns. Can > > > you elaborate? > > > > > > > Having the function return "success" when it failed to match is unexpected > > for me. There's only one invocation where we care about matching > > (in hv_compose_msi_msg). In that invocation the purpose for matching is to > > not remove the wrong entry, and the return value is ignored. So I think > > it all works correctly. > > You're reading it wrongly: the point is that there's nothing wrong in *not > removing the "wrong entry" (or in failing to match). In the mentioned use, > that means the channel callback has already processed "our" request, and > that we don't have to worry about the ID. (Otherwise, i.e. if we do match, > the callback will eventually scream "Invalid transaction".) > > > > Just thinking out loud, maybe vmbus_request_addr_match() should be > > renamed to vmbus_request_addr_remove(), and not have a return value? > > Mmh. We have vmbus_request_addr() that (always) removes the ID; it seems > a _remove() would just add to the confusion. And removing the return value > would mean duplicating most of vmbus_request_addr() in the "new" function. > So, I'm not convinced that's the right thing to do. I'm inclined to leave > this patch as is (and, as usual, happy to be proven wrong). >
I'll defer to your judgment. I don't see anything that broken with the patch as written, so I can live with it as is.
Michael
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