git: DragonFly_RELEASE_5_4 kernel - Fix rare vref() assertion
dillon at crater.dragonflybsd.org
Mon Dec 17 13:55:57 PST 2018
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date: Sat Dec 8 14:34:51 2018 -0800
kernel - Fix rare vref() assertion
* The VREF_TERMINATE flag gets cleared when a vnode is reactivated.
However, concurrent LK_SHARED locks on vnodes can race the v_state
test. Thus the code cannot assume that VREF_TERMINATE has been cleared
when v_state is VS_ACTIVE.
To avoid the race, we simply unconditionally clear VREF_TERMINATE on
a successful vget().
* Could be reproduced by running blogbench and synth together, both of
which generate extreme filesystem-intensive loads.
Summary of changes:
sys/kern/vfs_lock.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
DragonFly BSD source repository
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