linux-kernel - Re: [PATCH v8 13/13] nvmet-passthru: support block accounting

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7954e8a4-6026-2210-7192-94a4e483facf@grimberg.me>
Date:   Mon, 9 Sep 2019 12:26:35 -0700
From:   Sagi Grimberg <sagi@...mberg.me>
To:     Logan Gunthorpe <logang@...tatee.com>,
        linux-kernel@...r.kernel.org, linux-nvme@...ts.infradead.org,
        linux-block@...r.kernel.org, linux-fsdevel@...r.kernel.org
Cc:     Chaitanya Kulkarni <Chaitanya.Kulkarni@....com>,
        Stephen Bates <sbates@...thlin.com>, Jens Axboe <axboe@...com>,
        Keith Busch <kbusch@...nel.org>,
        Max Gurtovoy <maxg@...lanox.com>,
        Christoph Hellwig <hch@....de>
Subject: Re: [PATCH v8 13/13] nvmet-passthru: support block accounting


>>> Support block disk accounting by setting the RQF_IO_STAT flag
>>> and gendisk in the request.
>>>
>>> After this change, IO counts will be reflected correctly in
>>> /proc/diskstats for drives being used by passthru.
>>>
>>> Signed-off-by: Logan Gunthorpe <logang@...tatee.com>
>>> ---
>>>    drivers/nvme/target/io-cmd-passthru.c | 5 ++++-
>>>    1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/nvme/target/io-cmd-passthru.c b/drivers/nvme/target/io-cmd-passthru.c
>>> index 7557927a3451..63f12750a80d 100644
>>> --- a/drivers/nvme/target/io-cmd-passthru.c
>>> +++ b/drivers/nvme/target/io-cmd-passthru.c
>>> @@ -410,6 +410,9 @@ static struct request *nvmet_passthru_blk_make_request(struct nvmet_req *req,
>>>    	if (unlikely(IS_ERR(rq)))
>>>    		return rq;
>>>    
>>> +	if (blk_queue_io_stat(q) && cmd->common.opcode != nvme_cmd_flush)
>>> +		rq->rq_flags |= RQF_IO_STAT;
> 
> Thanks for the review!
> 
>> Does flush has data bytes in the request? Why the special casing?
> 
> Well it was special cased in the vanilla blk account flow... But I think
> it's required to be special cased so the IO and in_flight counts don't
> count flushes (as they do not for regular block device traffic).

I think that the accounting exclude I/O that is yielded from the flush
sequence. Don't think its relevant here...