ZFS and kernel panic (not kmem_map too small)

[Kris Kennaway]

On Fri, May 11, 2007 at 05:24:15PM +0300, John Doe wrote:
> Hi, All.
> 
> I'm running 7-CURRENT (cvsuped and builded at Fri May 11 12:27:49 EEST
> 2007) on Intel S3000AH motherboard, Xeon 3050 2.13GHz with 1GB RAM.
> Using Areca ARC-1260 (16 port sata raid controller) with 16 400GB sata
> drives in JBOD mode.
> 
> Create zpool with
> # zpool create bfs radiz2 da0 da1 da2 da3 da4 da5 da6 da7 da8 da9 da10
> da11 da12 da13 da14 da15
> 
> # zfs create bfs/test
> 
> # zfs list
> NAME       USED  AVAIL  REFER  MOUNTPOINT
> bfs        286M  4.97T  49.5K  /bfs
> bfs/test   286M  4.97T   286M  /bfs/test
> 
> # zpool status -v
>  pool: bfs
> state: ONLINE
> scrub: none requested
> config:
> 
>        NAME        STATE     READ WRITE CKSUM
>        bfs         ONLINE       0     0     0
>          raidz2    ONLINE       0     0     0
>            da0     ONLINE       0     0     0
>            da1     ONLINE       0     0     0
>            da2     ONLINE       0     0     0
>            da3     ONLINE       0     0     0
>            da4     ONLINE       0     0     0
>            da5     ONLINE       0     0     0
>            da6     ONLINE       0     0     0
>            da7     ONLINE       0     0     0
>            da8     ONLINE       0     0     0
>            da9     ONLINE       0     0     0
>            da10    ONLINE       0     0     0
>            da11    ONLINE       0     0     0
>            da12    ONLINE       0     0     0
>            da13    ONLINE       0     0     0
>            da14    ONLINE       0     0     0
>            da15    ONLINE       0     0     0
> 
> errors: No known data errors
> 
> all seems fine, but i got kernel panic, while putting one file to zfs
> filesystem using ftp:
> 
> lock order reversal:
> 1st 0xffffff0031205938 zfs:&dr->dt.di.dr_mtx (zfs:&dr->dt.di.dr_mtx)
> @ 
> /usr/src/sys/modules/zfs/../../contrib/opensolaris/uts/common/fs/zfs/dbuf.c:1866
> 2nd 0xffffff002f9ce418 zfs:&db->db_mtx (zfs:&db->db_mtx) @
> /usr/src/sys/modules/zfs/../../contrib/opensolaris/uts/common/fs/zfs/dbuf.c:1837
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x3a
> witness_checkorder() at witness_checkorder+0x4f9
> _sx_xlock() at _sx_xlock+0x48
> dbuf_sync_list() at dbuf_sync_list+0x7e
> dbuf_sync_list() at dbuf_sync_list+0x114
> dnode_sync() at dnode_sync+0x1ec
> dmu_objset_sync() at dmu_objset_sync+0xec
> dsl_pool_sync() at dsl_pool_sync+0x65
> spa_sync() at spa_sync+0x309
> txg_sync_thread() at txg_sync_thread+0x166
> fork_exit() at fork_exit+0xaa
> fork_trampoline() at fork_trampoline+0xe
> --- trap 0, rip = 0, rsp = 0xffffffffaeeadd30, rbp = 0 ---
> panic: Bad link elm 0xffffff003b362400 prev->next != elm
> cpuid = 1
> KDB: enter: panic
> 
> how can I provide more information to fix this problem?

By providing a backtrace and all the other usual details?  See the
developers handbook if you are unfamiliar with how to report panics.

Kris