ZoL #6981 stack trace

gistfile1.txt

[118631.700569] VERIFY3(0 == remove_reference(hdr, ((void *)0), tag)) failed (0 == 63)
[118631.702734] PANIC at arc.c:3076:arc_buf_destroy()
[118631.703816] Showing stack for process 7238
[118631.703824] CPU: 1 PID: 7238 Comm: z_rd_int_5 Tainted: P           O    4.9.59-v7+ #1047
[118631.703826] Hardware name: BCM2835
[118631.703847] [<8010fb3c>] (unwind_backtrace) from [<8010c058>] (show_stack+0x20/0x24)
[118631.703857] [<8010c058>] (show_stack) from [<80456764>] (dump_stack+0xd4/0x118)
[118631.703925] [<80456764>] (dump_stack) from [<7f138d80>] (spl_dumpstack+0x54/0x58 [spl])
[118631.704037] [<7f138d80>] (spl_dumpstack [spl]) from [<7f138e18>] (spl_panic+0x94/0xc8 [spl])
[118631.704591] [<7f138e18>] (spl_panic [spl]) from [<7f25b350>] (arc_buf_destroy+0x1a0/0x1b8 [zfs])
[118631.705496] [<7f25b350>] (arc_buf_destroy [zfs]) from [<7f261c3c>] (dbuf_read_done+0xa0/0xf4 [zfs])
[118631.706356] [<7f261c3c>] (dbuf_read_done [zfs]) from [<7f257830>] (arc_read_done+0x1dc/0x2fc [zfs])
[118631.707219] [<7f257830>] (arc_read_done [zfs]) from [<7f328aec>] (zio_done+0x3b8/0xf60 [zfs])
[118631.708092] [<7f328aec>] (zio_done [zfs]) from [<7f32644c>] (zio_execute+0xb8/0x12c [zfs])
[118631.708585] [<7f32644c>] (zio_execute [zfs]) from [<7f136b38>] (taskq_thread+0x298/0x490 [spl])
[118631.708646] [<7f136b38>] (taskq_thread [spl]) from [<8013c958>] (kthread+0x10c/0x124)
[118631.708656] [<8013c958>] (kthread) from [<80108148>] (ret_from_fork+0x14/0x2c)