panic: getnewbuf: locked buf _at_ kern/vfs_bio.c:1879

With current from Aug 18 02:12 UTC:

panic: getnewbuf: locked buf
cpuid = 0;
KDB: enter: panic
[thread 100188]
Stopped at      kdb_enter+0x30: leave
db> where
kdb_enter(c08b36e7,0,c08ba5e1,d13198d4,100) at kdb_enter+0x30
panic(c08ba5e1,80012,0,c1e0d160,c1c2d000) at panic+0x156
getnewbuf(0,0,4000,4000,fffd0000) at getnewbuf+0x286
getblk(c1c2d000,fffffff4,ffffffff,4000,0) at getblk+0x408
breadn(c1c2d000,fffffff4,ffffffff,4000,0) at breadn+0x52
bread(c1c2d000,fffffff4,ffffffff,4000,0) at bread+0x4c
ffs_balloc_ufs2(c1c2d000,a4adeb,0,2dec,c1a31080) at ffs_balloc_ufs2+0x1573
ffs_write(d1319c0c,20002,c1e0d160,246,680003) at ffs_write+0x37d
vn_write(c1d7e50c,d1319c80,c1a31080,0,c1e0d160) at vn_write+0x256
dofilewrite(c1e0d160,c1d7e50c,1,8048cd9,1) at dofilewrite+0xcb
write(c1e0d160,d1319d14,c,d1319d3c,3) at write+0x69
syscall(804002f,bfbf002f,bfbf002f,8049568,bfbfebd4) at syscall+0x2a0
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (4, FreeBSD ELF32, write), eip = 0x280c162f, esp = 0xbfbfeb4c, ebp = 0xbfbfeb8c ---

-- 
Peter Holm