stack dumps after upgrade (easy workaround)

[aarcane]

after a zfs upgrade, I get the following errors in my dmesg log:

[148527.284812] SPL: Showing stack for process 25415
[148527.284824] Pid: 25415, comm: zfs Tainted: P 2.6.38-11-server #50-Ubuntu
[148527.284831] Call Trace:
[148527.284856] [] ? spl_debug_dumpstack+0x27/0x40 [spl]
[148527.284875] [] ? kmem_alloc_debug+0x11d/0x130 [spl]
[148527.284951] [] ? zfs_prop_set_special+0x235/0x3e0 [zfs]
[148527.284964] [] ? zprop_get_proptable+0x13/0x30 [zcommon]
[148527.285028] [] ? zfs_set_prop_nvlist+0x177/0x680 [zfs]
[148527.285093] [] ? zfs_ioc_set_prop+0x7b/0x130 [zfs]
[148527.285156] [] ? spa_open+0x13/0x20 [zfs]
[148527.285219] [] ? zfsdev_ioctl+0xf6/0x1b0 [zfs]
[148527.285230] [] ? do_vfs_ioctl+0x8f/0x320
[148527.285239] [] ? schedule+0x3ec/0x760
[148527.285247] [] ? sys_ioctl+0x91/0xa0
[148527.285255] [] ? system_call_fastpath+0x16/0x1b

repeatedly, with time differences of about 1 sec.

I fixed it easily by calling rmmod zfs znvpair zavl zunicode zcommon spl a few times before re-running rmmod zfs, but I think there should be a simple utility script that will rmmod these modules in the proper order (but that isn't called by default!) and modprobe zfs again. Either that, or zfs should refuse to load if the in-kernel version of spl doesn't match.

[behlendorf]

This warning was fixed by commit fa6e5ce which will appear in 0.6.0-rc6. It was harmless for the record.

As for a script to remove the modules if your using the upstream packaging (not the PPA) you can run /usr/libexec/zfs/zfs.sh -u to remove the entire module stack. It's part of the zfs-test package.