From: Miklos Szeredi <mszeredi@xxxxxxx>
Since now the shrink list is private and nobody can free the dentry while
it is on the shrink list, we can remove RCU protection from this.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
(cherry picked from commit 60942f2f235ce7b817166cdf355eed729094834d)
---
fs/dcache.c | 27 ++++-----------------------
1 file changed, 4 insertions(+), 23 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 752db63..d20bae3 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -795,23 +795,9 @@ static void shrink_dentry_list(struct list_head *list)
{
struct dentry *dentry, *parent;
- rcu_read_lock();
- for (;;) {
- dentry = list_entry_rcu(list->prev, struct dentry, d_lru);
- if (&dentry->d_lru == list)
- break; /* empty */
-
- /*
- * Get the dentry lock, and re-verify that the dentry is
- * this on the shrinking list. If it is, we know that
- * DCACHE_SHRINK_LIST and DCACHE_LRU_LIST are set.
- */
+ while (!list_empty(list)) {
+ dentry = list_entry(list->prev, struct dentry, d_lru);
spin_lock(&dentry->d_lock);
- if (dentry != list_entry(list->prev, struct dentry, d_lru)) {
- spin_unlock(&dentry->d_lock);
- continue;
- }
-
/*
* The dispose list is isolated and dentries are not accounted
* to the LRU here, so we can simply remove it from the list
@@ -827,23 +813,20 @@ static void shrink_dentry_list(struct list_head *list)
spin_unlock(&dentry->d_lock);
continue;
}
- rcu_read_unlock();
parent = dentry_kill(dentry, 0);
/*
* If dentry_kill returns NULL, we have nothing more to do.
*/
- if (!parent) {
- rcu_read_lock();
+ if (!parent)
continue;
- }
+
if (unlikely(parent == dentry)) {
/*
* trylocks have failed and d_lock has been held the
* whole time, so it could not have been added to any
* other lists. Just add it back to the shrink list.
*/
- rcu_read_lock();
d_shrink_add(dentry, list);
spin_unlock(&dentry->d_lock);
continue;
@@ -857,9 +840,7 @@ static void shrink_dentry_list(struct list_head *list)
dentry = parent;
while (dentry && !lockref_put_or_lock(&dentry->d_lockref))
dentry = dentry_kill(dentry, 1);
- rcu_read_lock();
}
- rcu_read_unlock();
}
static enum lru_status
--
1.8.3.1
--
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