47 lines
1.3 KiB
Diff
47 lines
1.3 KiB
Diff
From: Al Viro <viro@zeniv.linux.org.uk>
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Date: Fri, 23 Feb 2018 22:07:35 -0500
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Subject: [PATCH 02/17] now lock_parent() can't run into killed dentry
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.16/older/patches-4.16.7-rt1.tar.xz
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Upstream commit 65d8eb5a8f5480756105173de147ef5d60163e2f
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all remaining callers hold either a reference or ->i_lock
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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fs/dcache.c | 13 +++----------
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1 file changed, 3 insertions(+), 10 deletions(-)
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--- a/fs/dcache.c
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+++ b/fs/dcache.c
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@@ -593,8 +593,6 @@ static inline struct dentry *lock_parent
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struct dentry *parent = dentry->d_parent;
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if (IS_ROOT(dentry))
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return NULL;
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- if (unlikely(dentry->d_lockref.count < 0))
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- return NULL;
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if (likely(spin_trylock(&parent->d_lock)))
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return parent;
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rcu_read_lock();
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@@ -614,16 +612,11 @@ static inline struct dentry *lock_parent
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spin_unlock(&parent->d_lock);
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goto again;
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}
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- if (parent != dentry) {
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+ rcu_read_unlock();
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+ if (parent != dentry)
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spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
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- if (unlikely(dentry->d_lockref.count < 0)) {
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- spin_unlock(&parent->d_lock);
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- parent = NULL;
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- }
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- } else {
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+ else
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parent = NULL;
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- }
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- rcu_read_unlock();
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return parent;
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}
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