kern/145339: [zfs] deadlock after detaching block device from raidz pool

[Steve Polyack]

The following reply was made to PR kern/145339; it has been noted by GNATS.

From: Steve Polyack <korvus at comcast.net>
To: bug-followup at FreeBSD.org, Alex.Bakhtin at gmail.com
Cc:  
Subject: Re: kern/145339: [zfs] deadlock after detaching block device from
 raidz pool
Date: Thu, 22 Apr 2010 11:13:26 -0400

 I've seen a similar issue in the past while testing hot-removal of RAIDZ 
 members (glabeled siis(4)-attached devices).  After the /dev/ada* entry 
 would disappear, the /dev/label/diskXX entry would remain and crash 
 shortly down the line with ZFS IO.  Here's the panic info in case it is 
 relevant:
 
 Fatal trap 12: page fault while in kernel mode
 cpuid = 2; apic id = 14
 fault virtual address   = 0x48
 fault code              = supervisor write data, page not present
 instruction pointer     = 0x20:0xffffffff8035f375
 stack pointer           = 0x28:0xffffff800006db60
 frame pointer           = 0x28:0xffffff800006db70
 code segment            = base 0x0, limit 0xfffff, type 0x1b
                         = DPL 0, pres 1, long 1, def32 0, gran 1
 processor eflags        = interrupt enabled, resume, IOPL = 0
 current process         = 2 (g_event)
 [thread pid 2 tid 100014 ]
 Stopped at      _mtx_lock_flags+0x15:   lock cmpxchgq   %rsi,0x18(%rdi)
 
 db> bt
 Tracing pid 2 tid 100014 td 0xffffff00014d4ab0
 _mtx_lock_flags() at _mtx_lock_flags+0x15
 vdev_geom_release() at vdev_geom_release+0x33
 vdev_geom_orphan() at vdev_geom_orphan+0x15c
 g_run_events() at g_run_events+0x104
 g_event_procbody() at g_event_procbody+0x55
 fork_exit() at fork_exit+0x118
 fork_trampoline() at fork_trampoline+0xe
 --- trap 0, rip = 0, rsp = 0xffffff800006dd30, rbp = 0 ---