HAMMER: panic: lockmgr: locking against myself

[Thomas Nikolajsen <thomas.nikolajsen@xxxxxxx>]

I get this panic consistently after 5-20 minutes when doing buildworld,
using nfs mount for /usr/src & /usr/obj and using hammer on nfs server.

Crash dump on leaf in crash/hammer/ask/*.13.

HAMMER PFSs are not used on nfs server
(unlike <https://bugs.dragonflybsd.org/issue1125>).

Retesting got another panic (like .13); on bootup a third panic occurred just after HAMMER:
*.14 and *.15 being uploaded to leaf.

 -thomas
-
#0  dumpsys () at ./machine/thread.h:83
#1  0xc02c64da in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:375
#2  0xc02c65fb in panic (fmt=0xc05235b7 "from debugger") at /usr/src/sys/kern/kern_shutdown.c:800
#3  0xc01648f5 in db_panic (addr=-1068756004, have_addr=0, count=-1, modif=0xc9dc53f8 "")
    at /usr/src/sys/ddb/db_command.c:447
#4  0xc0164f60 in db_command_loop () at /usr/src/sys/ddb/db_command.c:343
#5  0xc01674d8 in db_trap (type=3, code=0) at /usr/src/sys/ddb/db_trap.c:71
#6  0xc04c152f in kdb_trap (type=3, code=0, regs=0xc9dc54f0)
    at /usr/src/sys/platform/pc32/i386/db_interface.c:148
#7  0xc04d2db6 in trap (frame=0xc9dc54f0) at /usr/src/sys/platform/pc32/i386/trap.c:842
#8  0xc04c2247 in calltrap () at /usr/src/sys/platform/pc32/i386/exception.s:785
#9  0xc04c13dc in Debugger (msg=0xc0537b00 "panic") at ./cpu/cpufunc.h:73
#10 0xc02c65f2 in panic (fmt=0xc0567370 "lockmgr: locking against myself")
    at /usr/src/sys/kern/kern_shutdown.c:798
#11 0xc02bba9c in lockmgr (lkp=0xc12cf4e4, flags=131074) at /usr/src/sys/kern/kern_lock.c:348
#12 0xc02fc841 in regetblk (bp=0xc12cf3cc) at /usr/src/sys/sys/buf2.h:83
#13 0xc0430fdd in hammer_io_release (io=0xc9f8b680, flush=0)
    at /usr/src/sys/vfs/hammer/hammer_io.c:359
#14 0xc043816a in hammer_rel_buffer (buffer=0xc9f8b680, flush=0)
    at /usr/src/sys/vfs/hammer/hammer_ondisk.c:871
#15 0xc0431590 in hammer_io_inval (volume=0xc11707b0, zone2_offset=2305843240093351936)
    at /usr/src/sys/vfs/hammer/hammer_io.c:278
#16 0xc0438f33 in hammer_del_buffers (hmp=0xc9b13000, base_offset=2305843240093351936, 
    zone2_offset=2305843240093351936, bytes=8388608) at /usr/src/sys/vfs/hammer/hammer_ondisk.c:730
#17 0xc0425c3e in hammer_blockmap_reserve_complete (hmp=0xc9b13000, resv=0xc77d08b8)
    at /usr/src/sys/vfs/hammer/hammer_blockmap.c:594
#18 0xc0433b87 in hammer_rel_mem_record (record=0xca7ca368)
    at /usr/src/sys/vfs/hammer/hammer_object.c:434
#19 0xc04345b6 in hammer_ip_add_bulk (ip=0xca9ce448, file_offset=0, data=0xc15e0000, bytes=6688, 
    errorp=0xc9dc57e8) at /usr/src/sys/vfs/hammer/hammer_object.c:903
#20 0xc04401cd in hammer_vop_strategy (ap=0xc9dc5804)
    at /usr/src/sys/vfs/hammer/hammer_vnops.c:2611
#21 0xc0316e62 in vop_strategy (ops=0xc11f9af8, vp=0xca49db90, bio=0xc12bd5c4)
    at /usr/src/sys/kern/vfs_vopops.c:659
#22 0xc02fbabe in vn_strategy (vp=0xc066da0c, bio=0x7020) at /usr/src/sys/kern/vfs_bio.c:3089
#23 0xc02ff0fe in bwrite (bp=0xc12bd594) at /usr/src/sys/kern/vfs_bio.c:797
#24 0xc044160e in hammer_vop_write (ap=0xc9dc58d4) at /usr/src/sys/vfs/hammer/hammer_vnops.c:517
#25 0xc0316ebe in vop_write (ops=0xc11f9af8, vp=0xca49db90, uio=0xc9dc5954, ioflag=12, 
    cred=0xc11dcf98) at /usr/src/sys/kern/vfs_vopops.c:351
#26 0xc038f304 in nfsrv_write (nfsd=0xc11dcf18, slp=0xc11fef58, td=0xc11da038, mrq=0xc9dc5bac)
    at /usr/src/sys/vfs/nfs/nfs_serv.c:1105
#27 0xc039b871 in sys_nfssvc (uap=0xc9dc5cf0) at /usr/src/sys/vfs/nfs/nfs_syscalls.c:590