mirror_zfs/module
Chunwei Chen 07012da668 Fix kernel panic due to tsd_exit in ZFS_EXIT(zsb)
The following panic would occur under certain heavy load:
[ 4692.202686] Kernel panic - not syncing: thread ffff8800c4f5dd60 terminating with rrw lock ffff8800da1b9c40 held
[ 4692.228053] CPU: 1 PID: 6250 Comm: mmap_deadlock Tainted: P           OE  3.18.10 #7

The culprit is that ZFS_EXIT(zsb) would call tsd_exit() every time, which
would purge all tsd data for the thread. However, ZFS_ENTER is designed to be
reentrant, so we cannot allow ZFS_EXIT to blindly purge tsd data.

Instead, we rely on the new behavior of tsd_set. When NULL is passed as the
new value to tsd_set, it will automatically remove the tsd entry specified the
the key for the current thread.

rrw_tsd_key and zfs_allow_log_key already calls tsd_set(key, NULL) when
they're done. The zfs_fsyncer_key relied on ZFS_EXIT(zsb) to call tsd_exit() to
do clean up. Now we explicitly call tsd_set(key, NULL) on them.

Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3247
2015-04-24 14:57:54 -07:00
..
avl Retire spl_module_init()/spl_module_fini() 2015-02-24 11:37:44 -08:00
nvpair Retire spl_module_init()/spl_module_fini() 2015-02-24 11:37:44 -08:00
unicode Retire spl_module_init()/spl_module_fini() 2015-02-24 11:37:44 -08:00
zcommon Change ASSERT(!"...") to cmn_err(CE_PANIC, ...) 2015-03-03 13:22:21 -08:00
zfs Fix kernel panic due to tsd_exit in ZFS_EXIT(zsb) 2015-04-24 14:57:54 -07:00
zpios Retire spl_module_init()/spl_module_fini() 2015-02-24 11:37:44 -08:00
.gitignore gitignore: anchor entries at their respective directory 2013-04-02 10:50:17 -07:00
Makefile.in Fix modules installation directory 2014-10-28 09:46:14 -07:00