From a73f8844e1fc54c3762555c1cf1f71774142ca91 Mon Sep 17 00:00:00 2001
From: Jonathan Corbet <corbet@lwn.net>
Date: Wed, 8 Sep 2010 16:54:54 -0600
Subject: lglock: make lg_lock_global() actually lock globally
lg_lock_global() currently only acquires spinlocks for online CPUs, but
it's meant to lock all possible CPUs. Lglock-protected resources may be
associated with removed CPUs - and, indeed, that could happen with the
per-superblock open files lists.
At Nick's suggestion, change for_each_online_cpu() to
for_each_possible_cpu() to protect accesses to those resources.
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/lglock.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
(limited to 'include/linux/lglock.h')
diff --git a/include/linux/lglock.h b/include/linux/lglock.h
index b288cb713b9..f549056fb20 100644
--- a/include/linux/lglock.h
+++ b/include/linux/lglock.h
@@ -150,7 +150,7 @@
int i; \
preempt_disable(); \
rwlock_acquire(&name##_lock_dep_map, 0, 0, _RET_IP_); \
- for_each_online_cpu(i) { \
+ for_each_possible_cpu(i) { \
arch_spinlock_t *lock; \
lock = &per_cpu(name##_lock, i); \
arch_spin_lock(lock); \
@@ -161,7 +161,7 @@
void name##_global_unlock(void) { \
int i; \
rwlock_release(&name##_lock_dep_map, 1, _RET_IP_); \
- for_each_online_cpu(i) { \
+ for_each_possible_cpu(i) { \
arch_spinlock_t *lock; \
lock = &per_cpu(name##_lock, i); \
arch_spin_unlock(lock); \
--
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