Messages in this thread | | | From | Manjong Lee <> | Subject | [Question]Question about the possibility of a problem in blk_mq_complete_remote. | Date | Sat, 25 Dec 2021 00:10:09 +0900 |
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Dear block layer developers.
While studying the block layer code, there is something I don't understand about the code. It's hard to understand by myself. So I'd like to ask for your help.
I think the error can occur when the target cpu is changed to online -> offline during the ipi operation due to the request complete process below.
However, since the return value is not checked in the code, it seems that a problem may occur.
So I wonder is this code the real problem or is there any other defense code?
Function path.
blk_mq_complete_request_remote blk_mq_complete_need_ipi << Check if the cpu of rq is online blk_mq_complete_send_ipi << Assume that the target cpu becomes offline here. smp_call_function_single_async << send ipi to cpu and return -ENXIO if cpu is offline but it doesn't check the return value.
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