mirror_zfs/module
Richard Elling 78fac8d925 Fix kstat state update during pool transition
When reading kstats, the health (aka state) of the pool is stored into
/proc/spl/kstat/zfs/POOLNAME/state via spa_state_to_name().
However, during import/export there is a case where the spa exists,
but the root vdev does not exist. This fix checks that case and sets
the state to "TRANSITIONING"

Unfortunately, it is not easy to reproduce a test for this. It was
detected randomly during ZTS runs while kstats were also being sampled
regularly. After this change, further testing did not trip on the case
and the TRANSITIONING state was collected at least once by the kstats.

For posterity, the backtrace prior to this fix is:
[Mon May 13 17:21:00 2019] RIP: 0010:spa_state_to_name+0x10/0xb0 [zfs]
...
Mon May 13 17:21:00 2019] Call Trace:
[Mon May 13 17:21:00 2019]  spa_state_data+0x1a/0x40 [zfs]
[Mon May 13 17:21:00 2019]  kstat_seq_show+0x117/0x440 [spl]
[Mon May 13 17:21:00 2019]  seq_read+0xe5/0x430
[Mon May 13 17:21:00 2019]  proc_reg_read+0x45/0x70
[Mon May 13 17:21:00 2019]  __vfs_read+0x1b/0x40
[Mon May 13 17:21:00 2019]  vfs_read+0x8e/0x130
[Mon May 13 17:21:00 2019]  SyS_read+0x55/0xc0
[Mon May 13 17:21:00 2019]  ? SyS_fcntl+0x5d/0xb0
[Mon May 13 17:21:00 2019]  do_syscall_64+0x73/0x130
[Mon May 13 17:21:00 2019]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Closes #8746
2019-05-23 14:28:53 -07:00
..
avl Update build system and packaging 2018-05-29 16:00:33 -07:00
icp Restructure vec_idx loops 2019-04-16 12:34:06 -07:00
lua Update build system and packaging 2018-05-29 16:00:33 -07:00
nvpair Use NV_ENCODE_NATIVE for nvlist encoding variable 2019-04-26 11:24:31 -07:00
spl Linux 5.2 compat: rw_tryupgrade() 2019-05-23 13:46:33 -07:00
unicode Update build system and packaging 2018-05-29 16:00:33 -07:00
zcommon Add TRIM support 2019-03-29 09:13:20 -07:00
zfs Fix kstat state update during pool transition 2019-05-23 14:28:53 -07:00
.gitignore Prepare SPL repo to merge with ZFS repo 2018-05-29 14:51:39 -07:00
Makefile.in Linux 5.0 compat: Fix SUBDIRs 2019-01-28 10:11:45 -08:00