kern/44377: union whiteouts don't work on ffs -o log

[pooka%iki.fi@localhost]

>Number:         44377
>Category:       kern
>Synopsis:       union whiteouts don't work on ffs -o log
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jan 12 17:50:00 +0000 2011
>Originator:     Antti Kantee
>Release:        
>Organization:
>Environment:
>Description:
(gdb) bt
#0  0xbb8710d7 in _lwp_kill () from /usr/lib/libc.so.12
#1  0xbb87108e in raise () from /usr/lib/libc.so.12
#2  0xbb870914 in abort () from /usr/lib/libc.so.12
#3  0xbb8c7c01 in rumpuser_exit (rv=0) at rumpuser.c:517
#4  0xbb963490 in cpu_reboot (howto=4, bootstr=0x0) at rump.c:530
#5  0xbb931ed8 in panic (
    fmt=0xbb96b678 "kernel %sassertion \"%s\" failed: file \"%s\", line %d")
    at /usr/allsrc/src/sys/rump/librump/rumpkern/../../../kern/subr_prf.c:302
#6  0xbb9156ec in kern_assert (t=0xbb9e383b "diagnostic ", 
    f=0xbb9e37f8 
"/usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_wapbl.c", l=1617, 
e=0xbb9e3e30 "rw_lock_held(&wl->wl_rwlock)")
    at 
/usr/allsrc/src/sys/rump/librump/rumpkern/../../../lib/libkern/kern_assert.c:50
#7  0xbb9af13e in wapbl_jlock_assert (wl=0xbb6bf110)
    at /usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_wapbl.c:1617
#8  0xbb9ad830 in wapbl_add_buf (wl=0xbb6bf110, bp=0xbb6ca840)
    at /usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_wapbl.c:919
#9  0xbb9df7b8 in bdwrite (bp=0xbb6ca840)
    at /usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_bio.c:918
#10 0xbb9df3cf in bwrite (bp=0xbb6ca840)
    at /usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_bio.c:805
#11 0xbb9df605 in vn_bwrite (v=0xbfbfcc54)
    at /usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_bio.c:883
#12 0xbb928302 in VOP_BWRITE (bp=0xbb6ca840)
    at /usr/allsrc/src/sys/rump/librump/rumpkern/../../../kern/vnode_if.c:86
#13 0xbbb9d8c9 in ufs_direnter (dvp=0xbb67e198, tvp=0x0, dirp=0xbb6fbe70, 
    cnp=0xbfbfce18, newdirbp=0x0)
    at 
/usr/allsrc/src/sys/rump/fs/lib/libffs/../../../../ufs/ufs/ufs_lookup.c:936
#14 0xbbbaafe6 in ufs_whiteout (v=0xbfbfcdbc)
    at 
/usr/allsrc/src/sys/rump/fs/lib/libffs/../../../../ufs/ufs/ufs_vnops.c:907
#15 0xbb929d3a in VOP_WHITEOUT (dvp=0xbb67e198, cnp=0xbfbfce18, flags=1)
    at /usr/allsrc/src/sys/rump/librump/rumpkern/../../../kern/vnode_if.c:1353
#16 0xbbb0a38b in union_mkwhiteout (um=0xbb6d3280, dvp=0xbb67e198, 
    cnp=0xbfbfcf08, path=0xbb602218 "tensti")
    at 
/usr/allsrc/src/sys/rump/fs/lib/libunion/../../../../fs/union/union_subr.c:921
#17 0xbbb075e4 in union_remove (v=0xbfbfceac)
    at 
/usr/allsrc/src/sys/rump/fs/lib/libunion/../../../../fs/union/union_vnops.c:1169
#18 0xbb92908e in VOP_REMOVE (dvp=0xbb67e040, vp=0xbb6f9f0c, cnp=0xbfbfcf08)
    at /usr/allsrc/src/sys/rump/librump/rumpkern/../../../kern/vnode_if.c:728
#19 0xbb9c38d0 in do_sys_unlink (arg=0x8069e28 "tensti", seg=UIO_USERSPACE)
    at 
/usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_syscalls.c:2273
#20 0xbb9c37b8 in sys_unlink (l=0xb9cb3b00, uap=0xbfbfcfdc, retval=0xbfbfcfd4)
    at 
/usr/allsrc/src/sys/rump/librump/rumpvfs/../../../kern/vfs_syscalls.c:2216
#21 0xbb958e67 in sy_call (sy=0xbb9794f8, l=0xb9cb3b00, uap=0xbfbfcfdc, 
    rval=0xbfbfcfd4)
    at /usr/allsrc/src/sys/rump/librump/rumpkern/../../../sys/syscallvar.h:61
#22 0xbb958e28 in rsys_syscall (num=10, data=0xbfbfcfdc, dlen=4, 
    retval=0xbfbfcfd4) at rump_syscalls.c:42
#23 0xbb95913e in rump_sys_unlink (path=0x8069e28 "tensti")
    at rump_syscalls.c:180
#24 0x0804c941 in basic (tc=0x806e7fc, mp=0x8069e83 "/mnt") at t_union.c:108
#25 0x0804ced9 in atfu_ffslog_basic_body (tc=0x806e7fc) at t_union.c:116
#26 0x08065dad in atf_tc_run ()
#27 0x08064c56 in atf_tp_main ()
#28 0x0804da95 in main (argc=858980355, argv=0x1) at t_union.c:118
(gdb) quit

>How-To-Repeat:
run tests/fs/vfs/t_union
(to be added soon'ish)
>Fix: