nvme tcp receive errors

[Sagi Grimberg]

> Hi,

Hey Keith,

> While running a read-write mixed workload, we are observing errors like:
> 
>    nvme nvme4: queue 2 no space in request 0x1

This means that we get a data payload from a read request and
we don't have a bio/bvec space to store it, which means we
are probably not tracking the request iterator correctly if
tcpdump shows that we are getting the right data length.

> Based on tcpdump, all data for this queue is expected to satisfy the
> command request. I'm not familiar enough with the tcp interfaces, so
> could anyone provide pointers on how to debug this further?

What was the size of the I/O that you were using? Is this easily
reproducible?

Do you have the below applied:
ca1ff67d0fb1 ("nvme-tcp: fix possible data corruption with bio merges")
0dc9edaf80ea ("nvme-tcp: pass multipage bvec to request iov_iter")

I'm assuming yes if you are using the latest nvme tree...

Does the issue still happens when you revert 0dc9edaf80ea?