[ZFS] umount at reboot crashes

[James R. Van Artsdalen]

FreeBSD bigback.housenet.jrv 8.0-BETA2 FreeBSD 8.0-BETA2 #0 r195757M:
Mon Jul 20 10:27:28 CDT 2009    
james at bigback.housenet.jrv:/usr/obj/usr/src/sys/BIGTEX  amd64

I have a system that almost always crashes whenever it receives a ZFS
replication package ("zfs recv") that either deleted or renames
filesystems, both operations requiring unmounting.  Sometimes it crashes
later in the "zfs recv", sometimes not until I reboot that system.

The sx_xlock() in frame 10 seems a common theme in these crashes.

The dump is available.

#0  doadump () at pcpu.h:223
223     pcpu.h: No such file or directory.
        in pcpu.h
(kgdb) #0  doadump () at pcpu.h:223
#1  0xffffffff801dfdec in db_fncall (dummy1=Variable "dummy1" is not
available.
)
    at /usr/src/sys/ddb/db_command.c:548
#2  0xffffffff801e0121 in db_command (last_cmdp=0xffffffff80bbd9e0,
cmd_table=Variable "cmd_table" is not available.

) at /usr/src/sys/ddb/db_command.c:445
#3  0xffffffff801e0370 in db_command_loop ()
    at /usr/src/sys/ddb/db_command.c:498
#4  0xffffffff801e2349 in db_trap (type=Variable "type" is not available.
) at /usr/src/sys/ddb/db_main.c:229
#5  0xffffffff805bab85 in kdb_trap (type=12, code=0, tf=0xffffff810f20a690)
    at /usr/src/sys/kern/subr_kdb.c:534
#6  0xffffffff8083cf7d in trap_fatal (frame=0xffffff810f20a690,
eva=Variable "eva" is not available.
)
    at /usr/src/sys/amd64/amd64/trap.c:847
#7  0xffffffff8083d2ed in trap_pfault (frame=0xffffff810f20a690, usermode=0)
    at /usr/src/sys/amd64/amd64/trap.c:768
#8  0xffffffff8083dce3 in trap (frame=0xffffff810f20a690)
    at /usr/src/sys/amd64/amd64/trap.c:494
#9  0xffffffff80823883 in calltrap ()
    at /usr/src/sys/amd64/amd64/exception.S:224
#10 0xffffffff80592e4a in _sx_xlock (sx=0x58, opts=0,
    file=0xffffffff810b4d68
"/usr/src/sys/modules/zfs/../../cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c",
line=1807) at /usr/src/sys/kern/kern_sx.c:284
#11 0xffffffff80ffa9d7 in dmu_buf_update_user (db_fake=0x0,
    old_user_ptr=0xffffff0148924468, user_ptr=0x0, user_data_ptr_ptr=0x0,
    evict_func=0)
    at
/usr/src/sys/modules/zfs/../../cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c:1807
#12 0xffffffff810401e8 in zfs_znode_dmu_fini (zp=0xffffff0148924468)
    at
/usr/src/sys/modules/zfs/../../cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c:551
#13 0xffffffff8105fcee in zfs_freebsd_reclaim (ap=Variable "ap" is not
available.
)
    at
/usr/src/sys/modules/zfs/../../cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c:4381
#14 0xffffffff8061ae05 in vgonel (vp=0xffffff014893f3b0) at vnode_if.h:830
#15 0xffffffff8061e975 in vflush (mp=0xffffff01468355e0, rootrefs=0,
flags=0,
    td=0xffffff01468a3000) at /usr/src/sys/kern/vfs_subr.c:2449
#16 0xffffffff8105a598 in zfs_umount (vfsp=0xffffff01468355e0, fflag=524288)
    at
/usr/src/sys/modules/zfs/../../cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:996
#17 0xffffffff80616336 in dounmount (mp=0xffffff01468355e0,
flags=524288, td=Variable "td" is not available.
)
    at /usr/src/sys/kern/vfs_mount.c:1289
#18 0xffffffff8061be54 in vfs_unmountall ()
    at /usr/src/sys/kern/vfs_subr.c:3141
#19 0xffffffff8058b58f in boot (howto=0)
    at /usr/src/sys/kern/kern_shutdown.c:401
#20 0xffffffff8058b8b8 in reboot (td=Variable "td" is not available.
)
    at /usr/src/sys/kern/kern_shutdown.c:173
#21 0xffffffff8083d4af in syscall (frame=0xffffff810f20ac80)
    at /usr/src/sys/amd64/amd64/trap.c:984
#22 0xffffffff80823b61 in Xfast_syscall ()
    at /usr/src/sys/amd64/amd64/exception.S:373
#23 0x000000080078f96c in ?? ()
Previous frame inner to this frame (corrupt stack?)