Description of problem:
Upgraded my fedora 22 installation from kernel 4.0.4-303.fc22.x86_64 to 4.2.3-200.fc22.x86_64 and now iscsi target no longer works.

i have a windows computer that uses the microsoft iscsi initiator and this worked just fine on my 4.0.4 kernel but with 4.2.3 i get the following errors in dmesg:
---
Got unknown iSCSI OpCode: 0x43
Cannot recover from unknown opcode while ERL=0, closing iSCSI connection.
---
repeatedly when ms iscsi intiator tries to connect and then the connection fails resulting in unavailable isci devices.

after a bit of searching i found the following discussion that i think describes the issue very well:
http://www.spinics.net/lists/target-devel/msg10611.html

looks like there is a kernel bug.


How reproducible:
setup targetcli on linux and use a windows computer as iscsi initiator.
with older kernels like 4.0.4 it works, but with newer 4.2.3 kernel initiator is unable to connect.


Actual results:
not possible to connect

Expected results:
connection should work as it did with older kernels.