Re: bin/56728: iscsi redundancy doesn't work

[mlelstv%serpens.de@localhost (Michael van Elst)]

The following reply was made to PR bin/56728; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/56728: iscsi redundancy doesn't work
Date: Wed, 23 Feb 2022 03:58:57 -0000 (UTC)

 6bone%6bone.informatik.uni-leipzig.de@localhost writes:
 
 >On Tue, 22 Feb 2022, Michael van Elst wrote:
 
 >>
 >> Do you have any messages from that crash? A Backtrace ?
 >>
 
 >Does that help?
 
 
 >[ 98560.538286] sd3d: error reading fsbn 7415496930 of 
 >7415496930-7415496993 (sd3 bn 7415496930; cn 22490 tn 13 sn 6159)
 >[ 98591.063909] uvm_fault(0xffffffff81901bc0, 0xffff860067907000, 1) -> e
 >[ 98591.063909] fatal page fault in supervisor mode
 >[ 98591.063909] trap type 6 code 0 rip 0xffffffff8025381b cs 0x8 rflags 
 >0x10282 cr2 0xffff860067907070 ilevel 0 rsp 0xffff860396d57c20
 >[ 98591.063909] curlwp 0xffff8186f0a7c940 pid 0.390 lowest kstack 
 
 
 Looks like sd_diskstart is running with a NULL periph pointer.
 I don't see how that happens yet, but it is probably the result of
 detaching the sd device while in use. The detach message is
 probably not yet printed.
 
 So that's one problem.
 
 Detaching the sd device happens when no connection to the iscsi
 server exists and no connection cannot be re-established
 either.
 
 For multiple connections to an iscsi server you need to do something
 like:
 
 add_send_target    -> add target to list
 refresh_targets    -> get portals
 login              -> establish session (creates sd)
 add_connection     -> add redundant connection to session
 
 the man page doesn't look correct.
 
 # iscsictl add_send_target -a x.x.x.x
 Added Send Target 1
 # iscsictl refresh_targets
 OK
 # iscsictl list_targets
      1: iqn.2007-09.jp.ne.peach.istgt:pbulk1
         2: x.x.x.x:3260,1
      3: iqn.2007-09.jp.ne.peach.istgt:test
         4: x.x.x.x:3260,1
 # iscsictl login -P 4
 Created Session 2, Connection 1
 # iscsictl list_sessions
 Session 2: Target iqn.2007-09.jp.ne.peach.istgt:test
 # iscsictl add_connection -I 2
 Added Connection 2
 
 tcp        0      0  y.y.y.y.65330       x.x.x.x.3260         ESTABLISHED
 tcp        0      0  y.y.y.y.65331       x.x.x.x.3260         ESTABLISHED
 
 # tcpdrop y.y.y.y 65530 x.x.x.x 3260
 
 [ 793856.693477] S2C2: *** Connection Error, status=18, logout=2, state=3
 [ 793856.693477] S2C2: Write failed sock 0xffff8524621c5480 (ret: 32, req: 48, resid: 48)
 [ 793856.693477] S2C2: *** Connection Error, status=18, logout=-1, state=5
 [ 793858.693531] S2C2: Connection ReCreated successfully - status 0
 
 
 tcp        0      0  y.y.y.y.65329       x.x.x.x.3260         ESTABLISHED
 tcp        0      0  y.y.y.y.65331       x.x.x.x.3260         ESTABLISHED
 
 Not exactly the same (only a single target IP), but it shows how the
 connection gets re-established.