From: Sagi Grimberg <sagi@grimberg.me>
To: Hao Wang <pkuwangh@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>, Linux-nvme@lists.infradead.org
Subject: Re: Data corruption when using multiple devices with NVMEoF TCP
Date: Mon, 11 Jan 2021 17:29:37 -0800 [thread overview]
Message-ID: <fcb56817-1f34-e307-e888-45ebb661c31d@grimberg.me> (raw)
In-Reply-To: <4684c86a-8cc7-c5ae-0d6b-9f0e7c59eda5@grimberg.me>
> Hey Hao,
>
>> Here is the entire log (and it's a new one, i.e. above snippet not
>> included):
>> https://drive.google.com/file/d/16ArIs5-Jw4P2f17A_ftKLm1A4LQUFpmg/view?usp=sharing
>>
>>
>> What I found is the data corruption does not always happen, especially
>> when I copy a small directory. So I guess a lot of log entries should
>> just look fine.
>
> So this seems to be a breakage that existed for some time now with
> multipage bvecs that you have been the first one to report. This
> seems to be related to bio merges, which is seems strange to me
> why this just now comes up, perhaps it is the combination with
> raid0 that triggers this, I'm not sure.
OK, I think I understand what is going on. With multipage bvecs
bios can split in the middle of a bvec entry, and then merge
back with another bio.
The issue is that we are not capping the last bvec entry send length
calculation in that.
I think that just this can also resolve the issue:
--
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 973d5d683180..c6b0a189a494 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -201,8 +201,9 @@ static inline size_t nvme_tcp_req_cur_offset(struct
nvme_tcp_request *req)
static inline size_t nvme_tcp_req_cur_length(struct nvme_tcp_request *req)
{
- return min_t(size_t, req->iter.bvec->bv_len - req->iter.iov_offset,
- req->pdu_len - req->pdu_sent);
+ return min_t(size_t, req->iter.count,
+ min_t(size_t, req->iter.bvec->bv_len -
req->iter.iov_offset,
+ req->pdu_len - req->pdu_sent));
}
static inline size_t nvme_tcp_pdu_data_left(struct nvme_tcp_request *req)
--
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next prev parent reply other threads:[~2021-01-12 1:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-22 18:09 Data corruption when using multiple devices with NVMEoF TCP Hao Wang
2020-12-22 19:29 ` Sagi Grimberg
2020-12-22 19:58 ` Hao Wang
2020-12-23 8:41 ` Sagi Grimberg
2020-12-23 8:43 ` Christoph Hellwig
2020-12-23 21:23 ` Sagi Grimberg
2020-12-23 22:23 ` Hao Wang
2020-12-24 1:51 ` Hao Wang
2020-12-24 2:57 ` Sagi Grimberg
2020-12-24 10:28 ` Hao Wang
2020-12-24 17:56 ` Sagi Grimberg
2020-12-25 7:49 ` Hao Wang
2020-12-25 9:05 ` Sagi Grimberg
[not found] ` <CAJS6Edgb+yCW5q5dA=MEkL0eYs4MXoopdiz72nhkxpkd5Fe_cA@mail.gmail.com>
2020-12-29 1:25 ` Sagi Grimberg
2021-01-06 1:53 ` Sagi Grimberg
2021-01-06 8:21 ` Hao Wang
2021-01-11 8:56 ` Hao Wang
2021-01-11 10:11 ` Sagi Grimberg
[not found] ` <CAJS6Edi9Es1zR9QC+=kwVjAFAGYrEru4vibW42ffyWoMDutFhQ@mail.gmail.com>
2021-01-12 0:36 ` Sagi Grimberg
2021-01-12 1:29 ` Sagi Grimberg [this message]
2021-01-12 2:22 ` Ming Lei
2021-01-12 6:49 ` Sagi Grimberg
2021-01-12 8:55 ` Hao Wang
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