Andriy Gapon 0451d4e97b MFV r309249: 3821 Race in rollback, zil close, and zil flush ... Note: there was a merge conflict resolved by me. illumos/illumos-gate@43297f973a 43297f973a https://www.illumos.org/issues/3821 We recently had nodes with some of the latest zfs bits panic on us in a rollback-heavy environment. The following is from my preliminary analysis: Let's look at where we died: > $C ffffff01ea6b9a10 taskq_dispatch+0x3a(0, fffffffff7d20450, ffffff5551dea920, 1) ffffff01ea6b9a60 zil_clean+0xce(ffffff4b7106c080, 7e0f1) ffffff01ea6b9aa0 dsl_pool_sync_done+0x47(ffffff4313065680, 7e0f1) ffffff01ea6b9b70 spa_sync+0x55f(ffffff4310c1d040, 7e0f1) ffffff01ea6b9c20 txg_sync_thread+0x20f(ffffff4313065680) ffffff01ea6b9c30 thread_start+8() If we dig in we can find that this dataset corresponds to a zone: > ffffff4b7106c080::print zilog_t zl_os->os_dsl_dataset->ds_dir->dd_myname zl_os->os_dsl_dataset->ds_dir->dd_myname = [ "8ffce16a-13c2-4efa-a233- 9e378e89877b" ] Okay so we have a null taskq pointer. That only happens during the calls to zil_open and zil_close. If we poke around we can see that we're actually in midst of a rollback: > ::pgrep zfs | ::printf "0x%x %s\\n" proc_t . p_user.u_psargs 0xffffff43262800a0 zfs rollback zones/15714eb6-f5ea-469f-ac6d- 4b8ab06213c2@marlin_init 0xffffff54e22a1028 zfs rollback zones/8ffce16a-13c2-4efa-a233- 9e378e89877b@marlin_init 0xffffff4362f3a058 zfs rollback zones/0ddb8e49-ca7e-42e1-8fdc- 4ac4ba8fe9f8@marlin_init 0xffffff5748e8d020 zfs rollback zones/426357b5-832d-4430-953e- 10cd45ff8e9f@marlin_init 0xffffff436b867008 zfs rollback zones/8f36bf37-8a9c-4a44-995c- 6d1b2751e6f5@marlin_init 0xffffff4381ad4090 zfs rollback zones/6c8eca18-fbd6-46dd-ac24- 2ed45cd0da70@marlin_init Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Dan Kimmel <dan.kimmel@delphix.com> Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com> Reviewed by: Andriy Gapon <avg@FreeBSD.org> Approved by: Richard Lowe <richlowe@richlowe.net> Author: George Wilson <george.wilson@delphix.com> MFC after: 3 weeks		2016-11-28 15:14:31 +00:00
..
boot/zfs	Bug 212114 - loader: zio_checksum_verify() must test spa for NULL pointer	2016-08-24 16:30:15 +00:00
compat/opensolaris	Remove PG_CACHED-related fields from struct vmmeter, because they are no	2016-11-22 18:13:46 +00:00
contrib/opensolaris	MFV r309249: 3821 Race in rollback, zil close, and zil flush	2016-11-28 15:14:31 +00:00
dev	Add tunable to disable destructive dtrace	2016-11-23 22:50:20 +00:00