Re: Data corruption in kernel 5.1+ with iSER attached ramdisk

Stephen Rust
2019-12-02T18:42:28Z

Hi Ming,

> I may get one machine with Mellanox NIC, is it easy to setup & reproduce
> just in the local machine(both host and target are setup on same machine)?

Yes, I have reproduced locally on one machine (using the IP address of
the Mellanox NIC as the target IP), with iser enabled on the target,
and iscsiadm connected via iser.

e.g.:
target:
/iscsi/iqn.20.../0.0.0.0:3260> enable_iser true
iSER enable now: True

| | o- portals
....................................................................................................
[Portals: 1]
| | o- 0.0.0.0:3260
...................................................................................................
[iser]

client:
# iscsiadm -m node -o update --targetname <target> -n
iface.transport_name -v iser
# iscsiadm -m node --targetname <target> --login
# iscsiadm -m session
iser: [3] 172.16.XX.XX:3260,1
iqn.2003-01.org.linux-iscsi.x8664:sn.c46c084919b0 (non-flash)

> Please try to trace bio_add_page() a bit via 'bpftrace ./ilo.bt'.

Here is the output of this trace from a failed run:

# bpftrace lio.bt
modprobe: FATAL: Module kheaders not found.
Attaching 3 probes...
512 76
4096 0
4096 0
4096 0
4096 76
512 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
4096 0
^C

@start[14475]: 0
@start[14384]: 0
@start[6764]: 0
@start[14477]: 0
@start[7771]: 0
@start[13788]: 0
@start[6879]: 0
@start[11842]: 0
@start[7765]: 0
@start[7782]: 0
@start[14476]: 0
@start[14385]: 0
@start[14474]: 0
@start[11564]: 0
@start[7753]: 0
@start[7786]: 0
@start[7791]: 0
@start[6878]: 0
@start[7411]: 0
@start[14473]: 0
@start[11563]: 0
@start[7681]: 0
@start[7756]: 0

Thanks,
Steve