rhashtable: Remove GFP flag from rhashtable_walk_init
The commit 8f6fd83c6c5ec66a4a70c728535ddcdfef4f3697 ("rhashtable:
accept GFP flags in rhashtable_walk_init") added a GFP flag argument
to rhashtable_walk_init because some users wish to use the walker
in an unsleepable context.
In fact we don't need to allocate memory in rhashtable_walk_init
at all. The walker is always paired with an iterator so we could
just stash ourselves there.
This patch does that by introducing a new enter function to replace
the existing init function. This way we don't have to churn all
the existing users again.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 5ba520b5..97e3cf0 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -489,10 +489,9 @@
EXPORT_SYMBOL_GPL(rhashtable_insert_slow);
/**
- * rhashtable_walk_init - Initialise an iterator
+ * rhashtable_walk_enter - Initialise an iterator
* @ht: Table to walk over
* @iter: Hash table Iterator
- * @gfp: GFP flags for allocations
*
* This function prepares a hash table walk.
*
@@ -507,30 +506,22 @@
* This function may sleep so you must not call it from interrupt
* context or with spin locks held.
*
- * You must call rhashtable_walk_exit if this function returns
- * successfully.
+ * You must call rhashtable_walk_exit after this function returns.
*/
-int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter,
- gfp_t gfp)
+void rhashtable_walk_enter(struct rhashtable *ht, struct rhashtable_iter *iter)
{
iter->ht = ht;
iter->p = NULL;
iter->slot = 0;
iter->skip = 0;
- iter->walker = kmalloc(sizeof(*iter->walker), gfp);
- if (!iter->walker)
- return -ENOMEM;
-
spin_lock(&ht->lock);
- iter->walker->tbl =
+ iter->walker.tbl =
rcu_dereference_protected(ht->tbl, lockdep_is_held(&ht->lock));
- list_add(&iter->walker->list, &iter->walker->tbl->walkers);
+ list_add(&iter->walker.list, &iter->walker.tbl->walkers);
spin_unlock(&ht->lock);
-
- return 0;
}
-EXPORT_SYMBOL_GPL(rhashtable_walk_init);
+EXPORT_SYMBOL_GPL(rhashtable_walk_enter);
/**
* rhashtable_walk_exit - Free an iterator
@@ -541,10 +532,9 @@
void rhashtable_walk_exit(struct rhashtable_iter *iter)
{
spin_lock(&iter->ht->lock);
- if (iter->walker->tbl)
- list_del(&iter->walker->list);
+ if (iter->walker.tbl)
+ list_del(&iter->walker.list);
spin_unlock(&iter->ht->lock);
- kfree(iter->walker);
}
EXPORT_SYMBOL_GPL(rhashtable_walk_exit);
@@ -570,12 +560,12 @@
rcu_read_lock();
spin_lock(&ht->lock);
- if (iter->walker->tbl)
- list_del(&iter->walker->list);
+ if (iter->walker.tbl)
+ list_del(&iter->walker.list);
spin_unlock(&ht->lock);
- if (!iter->walker->tbl) {
- iter->walker->tbl = rht_dereference_rcu(ht->tbl, ht);
+ if (!iter->walker.tbl) {
+ iter->walker.tbl = rht_dereference_rcu(ht->tbl, ht);
return -EAGAIN;
}
@@ -597,7 +587,7 @@
*/
void *rhashtable_walk_next(struct rhashtable_iter *iter)
{
- struct bucket_table *tbl = iter->walker->tbl;
+ struct bucket_table *tbl = iter->walker.tbl;
struct rhashtable *ht = iter->ht;
struct rhash_head *p = iter->p;
@@ -630,8 +620,8 @@
/* Ensure we see any new tables. */
smp_rmb();
- iter->walker->tbl = rht_dereference_rcu(tbl->future_tbl, ht);
- if (iter->walker->tbl) {
+ iter->walker.tbl = rht_dereference_rcu(tbl->future_tbl, ht);
+ if (iter->walker.tbl) {
iter->slot = 0;
iter->skip = 0;
return ERR_PTR(-EAGAIN);
@@ -651,7 +641,7 @@
__releases(RCU)
{
struct rhashtable *ht;
- struct bucket_table *tbl = iter->walker->tbl;
+ struct bucket_table *tbl = iter->walker.tbl;
if (!tbl)
goto out;
@@ -660,9 +650,9 @@
spin_lock(&ht->lock);
if (tbl->rehash < tbl->size)
- list_add(&iter->walker->list, &tbl->walkers);
+ list_add(&iter->walker.list, &tbl->walkers);
else
- iter->walker->tbl = NULL;
+ iter->walker.tbl = NULL;
spin_unlock(&ht->lock);
iter->p = NULL;