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authorHerbert Xu <herbert@gondor.apana.org.au>2016-08-18 16:50:56 +0800
committerDavid S. Miller <davem@davemloft.net>2016-08-19 14:40:24 -0700
commit246779dd090bd1b74d2652b3a6ca7759f593b27a (patch)
tree63526206a69c1ec56bc8490839504095ab0428f9
parent363dc396a5030ca82aa3e1a55b7d72965f968849 (diff)
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>
-rw-r--r--include/linux/rhashtable.h14
-rw-r--r--lib/rhashtable.c46
2 files changed, 29 insertions, 31 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 3eef0802a0cd..8b72ee710f95 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -173,7 +173,7 @@ struct rhashtable_walker {
struct rhashtable_iter {
struct rhashtable *ht;
struct rhash_head *p;
- struct rhashtable_walker *walker;
+ struct rhashtable_walker walker;
unsigned int slot;
unsigned int skip;
};
@@ -346,8 +346,8 @@ struct bucket_table *rhashtable_insert_slow(struct rhashtable *ht,
struct bucket_table *old_tbl);
int rhashtable_insert_rehash(struct rhashtable *ht, struct bucket_table *tbl);
-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);
void rhashtable_walk_exit(struct rhashtable_iter *iter);
int rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU);
void *rhashtable_walk_next(struct rhashtable_iter *iter);
@@ -906,4 +906,12 @@ static inline int rhashtable_replace_fast(
return err;
}
+/* Obsolete function, do not use in new code. */
+static inline int rhashtable_walk_init(struct rhashtable *ht,
+ struct rhashtable_iter *iter, gfp_t gfp)
+{
+ rhashtable_walk_enter(ht, iter);
+ return 0;
+}
+
#endif /* _LINUX_RHASHTABLE_H */
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 5ba520b544d7..97e3cf08142c 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -489,10 +489,9 @@ exit:
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 @@ EXPORT_SYMBOL_GPL(rhashtable_insert_slow);
* 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 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_init);
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 @@ int rhashtable_walk_start(struct rhashtable_iter *iter)
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 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_start);
*/
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 @@ next:
/* 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 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter)
__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 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter)
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;