kern/122087: [zfs][lor] exclusive sleep mutex struct mount mtx

[Francois Ranchin]

>Number:         122087
>Category:       kern
>Synopsis:       [zfs][lor] exclusive sleep mutex struct mount mtx
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Mar 25 19:20:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Francois Ranchin
>Release:        7.0-STABLE
>Organization:
>Environment:
FreeBSD noway.fyrou.net 7.0-STABLE FreeBSD 7.0-STABLE #0: Mon Mar 24 22:02:50 CET 2008     root at noway.fyrou.net:/usr/obj/usr/src/sys/NOWAY  i386

>Description:
Mar 24 23:14:31 noway kernel: lock order reversal:
Mar 24 23:14:31 noway kernel: 1st 0xc6124804 struct mount mtx (struct mount mtx) @ /usr/src/sys/modules/zfs/../../compat/opensolaris/kern/opensolaris_vfs.c:206
Mar 24 23:14:31 noway kernel: 2nd 0xc59cc010 sleep mtxpool (sleep mtxpool) @ /usr/src/sys/kern/kern_resource.c:1273
Mar 24 23:14:31 noway kernel: uma_zalloc_arg: zone "256" with the following non-sleepable locks held:
Mar 24 23:14:31 noway kernel: exclusive sleep mutex struct mount mtx r = 0 (0xc6124804) locked @ /usr/src/sys/modules/zfs/../../compat/opensolaris/kern/opensolaris_vfs.c:206
Mar 24 23:14:31 noway kernel: uma_zalloc_arg: zone "256" with the following non-sleepable locks held:
Mar 24 23:14:31 noway kernel: exclusive sleep mutex struct mount mtx r = 0 (0xc6124568) locked @ /usr/src/sys/modules/zfs/../../compat/opensolaris/kern/opensolaris_vfs.c:206

This messages comes after the 14th march 2008. I have played from this date to 24th with a debug kernel for testing the age driver from Pyun. And nerver seen. csup the 24th, compiled and installed with debuging active and seen these messages. 
>How-To-Repeat:
play with zfs,  I have an hourly snapshot running. One of them become undestroyable without panicing .
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: