zfs/module
George Amanakis 6c6153e5b8 Avoid dirtying the final TXGs when exporting a pool
There are two codepaths than can dirty final TXGs:

1) If calling spa_export_common()->spa_unload()->
   spa_unload_log_sm_flush_all() after the spa_final_txg is set, then
   spa_sync()->spa_flush_metaslabs() may end up dirtying the final
   TXGs. Then we have the following panic:
   Call Trace:
    <TASK>
    dump_stack_lvl+0x46/0x62
    spl_panic+0xea/0x102 [spl]
    dbuf_dirty+0xcd6/0x11b0 [zfs]
    zap_lockdir_impl+0x321/0x590 [zfs]
    zap_lockdir+0xed/0x150 [zfs]
    zap_update+0x69/0x250 [zfs]
    feature_sync+0x5f/0x190 [zfs]
    space_map_alloc+0x83/0xc0 [zfs]
    spa_generate_syncing_log_sm+0x10b/0x2f0 [zfs]
    spa_flush_metaslabs+0xb2/0x350 [zfs]
    spa_sync_iterate_to_convergence+0x15a/0x320 [zfs]
    spa_sync+0x2e0/0x840 [zfs]
    txg_sync_thread+0x2b1/0x3f0 [zfs]
    thread_generic_wrapper+0x62/0xa0 [spl]
    kthread+0x127/0x150
    ret_from_fork+0x22/0x30
    </TASK>

2) Calling vdev_*_stop_all() for a second time in spa_unload() after
   spa_export_common() unnecessarily delays the final TXGs beyond what
   spa_final_txg is set at.

Fix this by performing the check and call for
spa_unload_log_sm_flush_all() before the spa_final_txg is set in
spa_export_common(). Also check if the spa_final_txg has already been
set in spa_unload() and skip those calls in this case.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
External-issue: https://www.illumos.org/issues/9081
Closes #13048 
Closes #13098
2022-02-23 16:47:33 -08:00
..
avl Fix various typos 2021-04-07 13:27:11 -07:00
icp Use fallthrough macro 2021-11-02 09:50:30 -07:00
lua Use fallthrough macro 2021-11-02 09:50:30 -07:00
nvpair Update `checkstyle` workflow env to ubuntu-20.04 2021-12-08 13:27:56 -08:00
os module: zfs: fix unused, remove argsused 2022-02-16 17:58:56 -08:00
spl Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
unicode Update `checkstyle` workflow env to ubuntu-20.04 2021-12-08 13:27:56 -08:00
zcommon Linux 5.16 compat: don't use XSTATE_XSAVE to save FPU state 2022-02-16 17:58:55 -08:00
zfs Avoid dirtying the final TXGs when exporting a pool 2022-02-23 16:47:33 -08:00
zstd Linux 5.16: Resolve ZSTD_isError symbol collision in Linux kernel 2021-12-07 13:14:24 -08:00
.gitignore Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
Kbuild.in Add zstd support to zfs 2020-08-20 10:30:06 -07:00
Makefile.bsd Restore FreeBSD resource usage accounting 2021-02-19 22:34:33 -08:00
Makefile.in Add support for $KERNEL_{CC,LD,LLVM} variables 2022-02-16 17:58:55 -08:00