Re: zfs panic

On Wed, Jun 23, 2010 at 01:47:33PM -0700, Xin LI wrote:
> > 
> > panic: _sx_xlock_hard: recursed on non-recursive sx buf_hash_table.ht_locks[i].ht_lock _at_ /usr/src/sys/modules/zfs/../../cddl/contrib/opensolaris/uts/c
> > ommon/fs/zfs/arc.c:1626
> 
> Any chance to obtain a backtrace for the panic?

>From r209229:

db:0:kdb.enter.default>  bt
Tracing pid 3233 tid 100396 td 0xffffff013600f000
kdb_enter() at kdb_enter+0x3d
panic() at panic+0x1c8
_sx_xlock_hard() at _sx_xlock_hard+0x93
_sx_xlock() at _sx_xlock+0xaa
arc_buf_remove_ref() at arc_buf_remove_ref+0x7b
dbuf_rele() at dbuf_rele+0x15d
zfs_freebsd_reclaim() at zfs_freebsd_reclaim+0xe1
VOP_RECLAIM_APV() at VOP_RECLAIM_APV+0xe8
vgonel() at vgonel+0x186
vnlru_free() at vnlru_free+0x2f4
vfs_lowmem() at vfs_lowmem+0x31
kmem_malloc() at kmem_malloc+0x12c
page_alloc() at page_alloc+0x18
keg_alloc_slab() at keg_alloc_slab+0xe6
keg_fetch_slab() at keg_fetch_slab+0x18e
zone_fetch_slab() at zone_fetch_slab+0x4f
uma_zalloc_arg() at uma_zalloc_arg+0x56b
arc_get_data_buf() at arc_get_data_buf+0xaa
arc_read_nolock() at arc_read_nolock+0x1cb
arc_read() at arc_read+0x71
dbuf_read() at dbuf_read+0x4ea
dmu_buf_hold_array_by_dnode() at dmu_buf_hold_array_by_dnode+0x119
dmu_buf_hold_array() at dmu_buf_hold_array+0x57
dmu_read_uio() at dmu_read_uio+0x3f
zfs_freebsd_read() at zfs_freebsd_read+0x558
VOP_READ_APV() at VOP_READ_APV+0xe2
vn_read() at vn_read+0x1d0
dofileread() at dofileread+0x97
kern_preadv() at kern_preadv+0x6a
pread() at pread+0x52
syscallenter() at syscallenter+0x217
syscall() at syscall+0x39
Xfast_syscall() at Xfast_syscall+0xe1
--- syscall (475, FreeBSD ELF64, pread), rip = 0x80100c14c, rsp = 0x7fffffbfeb48, rbp = 0x2 ---

Thanks.