From ff302db965b57c141297911ea647d36d11fedfbe Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 2 Apr 2019 10:07:45 +1100 Subject: rhashtable: allow rht_bucket_var to return NULL. Rather than returning a pointer to a static nulls, rht_bucket_var() now returns NULL if the bucket doesn't exist. This will make the next patch, which stores a bitlock in the bucket pointer, somewhat cleaner. This change involves introducing __rht_bucket_nested() which is like rht_bucket_nested(), but doesn't provide the static nulls, and changing rht_bucket_nested() to call this and possible provide a static nulls - as is still needed for the non-var case. Signed-off-by: NeilBrown Signed-off-by: David S. Miller --- include/linux/rhashtable.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'include/linux/rhashtable.h') diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index 86dfa417848d..0c9175aeab8a 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -265,6 +265,8 @@ void rhashtable_destroy(struct rhashtable *ht); struct rhash_head __rcu **rht_bucket_nested(const struct bucket_table *tbl, unsigned int hash); +struct rhash_head __rcu **__rht_bucket_nested(const struct bucket_table *tbl, + unsigned int hash); struct rhash_head __rcu **rht_bucket_nested_insert(struct rhashtable *ht, struct bucket_table *tbl, unsigned int hash); @@ -294,7 +296,7 @@ static inline struct rhash_head __rcu *const *rht_bucket( static inline struct rhash_head __rcu **rht_bucket_var( struct bucket_table *tbl, unsigned int hash) { - return unlikely(tbl->nest) ? rht_bucket_nested(tbl, hash) : + return unlikely(tbl->nest) ? __rht_bucket_nested(tbl, hash) : &tbl->buckets[hash]; } @@ -890,6 +892,8 @@ static inline int __rhashtable_remove_fast_one( spin_lock_bh(lock); pprev = rht_bucket_var(tbl, hash); + if (!pprev) + goto out; rht_for_each_from(he, *pprev, tbl, hash) { struct rhlist_head *list; @@ -934,6 +938,7 @@ static inline int __rhashtable_remove_fast_one( break; } +out: spin_unlock_bh(lock); if (err > 0) { @@ -1042,6 +1047,8 @@ static inline int __rhashtable_replace_fast( spin_lock_bh(lock); pprev = rht_bucket_var(tbl, hash); + if (!pprev) + goto out; rht_for_each_from(he, *pprev, tbl, hash) { if (he != obj_old) { pprev = &he->next; @@ -1053,7 +1060,7 @@ static inline int __rhashtable_replace_fast( err = 0; break; } - +out: spin_unlock_bh(lock); return err; -- cgit