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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-05 20:11:24 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-05 20:11:24 +0300
commit687ee0ad4e897e29f4b41f7a20c866d74c5e0660 (patch)
treeb31a2af35c24a54823674cdd126993b80daeac67 /include/linux/rhashtable.h
parent3ddf40e8c31964b744ff10abb48c8e36a83ec6e7 (diff)
parent03a1eabc3f54469abd4f1784182851b2e29630cc (diff)
downloadlinux-687ee0ad4e897e29f4b41f7a20c866d74c5e0660.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: 1) BBR TCP congestion control, from Neal Cardwell, Yuchung Cheng and co. at Google. https://lwn.net/Articles/701165/ 2) Do TCP Small Queues for retransmits, from Eric Dumazet. 3) Support collect_md mode for all IPV4 and IPV6 tunnels, from Alexei Starovoitov. 4) Allow cls_flower to classify packets in ip tunnels, from Amir Vadai. 5) Support DSA tagging in older mv88e6xxx switches, from Andrew Lunn. 6) Support GMAC protocol in iwlwifi mwm, from Ayala Beker. 7) Support ndo_poll_controller in mlx5, from Calvin Owens. 8) Move VRF processing to an output hook and allow l3mdev to be loopback, from David Ahern. 9) Support SOCK_DESTROY for UDP sockets. Also from David Ahern. 10) Congestion control in RXRPC, from David Howells. 11) Support geneve RX offload in ixgbe, from Emil Tantilov. 12) When hitting pressure for new incoming TCP data SKBs, perform a partial rathern than a full purge of the OFO queue (which could be huge). From Eric Dumazet. 13) Convert XFRM state and policy lookups to RCU, from Florian Westphal. 14) Support RX network flow classification to igb, from Gangfeng Huang. 15) Hardware offloading of eBPF in nfp driver, from Jakub Kicinski. 16) New skbmod packet action, from Jamal Hadi Salim. 17) Remove some inefficiencies in snmp proc output, from Jia He. 18) Add FIB notifications to properly propagate route changes to hardware which is doing forwarding offloading. From Jiri Pirko. 19) New dsa driver for qca8xxx chips, from John Crispin. 20) Implement RFC7559 ipv6 router solicitation backoff, from Maciej Żenczykowski. 21) Add L3 mode to ipvlan, from Mahesh Bandewar. 22) Support 802.1ad in mlx4, from Moshe Shemesh. 23) Support hardware LRO in mediatek driver, from Nelson Chang. 24) Add TC offloading to mlx5, from Or Gerlitz. 25) Convert various drivers to ethtool ksettings interfaces, from Philippe Reynes. 26) TX max rate limiting for cxgb4, from Rahul Lakkireddy. 27) NAPI support for ath10k, from Rajkumar Manoharan. 28) Support XDP in mlx5, from Rana Shahout and Saeed Mahameed. 29) UDP replicast support in TIPC, from Richard Alpe. 30) Per-queue statistics for qed driver, from Sudarsana Reddy Kalluru. 31) Support BQL in thunderx driver, from Sunil Goutham. 32) TSO support in alx driver, from Tobias Regnery. 33) Add stream parser engine and use it in kcm. 34) Support async DHCP replies in ipconfig module, from Uwe Kleine-König. 35) DSA port fast aging for mv88e6xxx driver, from Vivien Didelot. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1715 commits) mlxsw: switchx2: Fix misuse of hard_header_len mlxsw: spectrum: Fix misuse of hard_header_len net/faraday: Stop NCSI device on shutdown net/ncsi: Introduce ncsi_stop_dev() net/ncsi: Rework the channel monitoring net/ncsi: Allow to extend NCSI request properties net/ncsi: Rework request index allocation net/ncsi: Don't probe on the reserved channel ID (0x1f) net/ncsi: Introduce NCSI_RESERVED_CHANNEL net/ncsi: Avoid unused-value build warning from ia64-linux-gcc net: Add netdev all_adj_list refcnt propagation to fix panic net: phy: Add Edge-rate driver for Microsemi PHYs. vmxnet3: Wake queue from reset work i40e: avoid NULL pointer dereference and recursive errors on early PCI error qed: Add RoCE ll2 & GSI support qed: Add support for memory registeration verbs qed: Add support for QP verbs qed: PD,PKEY and CQ verb support qed: Add support for RoCE hw init qede: Add qedr framework ...
Diffstat (limited to 'include/linux/rhashtable.h')
-rw-r--r--include/linux/rhashtable.h543
1 files changed, 429 insertions, 114 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 3eef0802a0cd..5c132d3188be 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -1,7 +1,7 @@
/*
* Resizable, Scalable, Concurrent Hash Table
*
- * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
+ * Copyright (c) 2015-2016 Herbert Xu <herbert@gondor.apana.org.au>
* Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch>
* Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
*
@@ -53,6 +53,11 @@ struct rhash_head {
struct rhash_head __rcu *next;
};
+struct rhlist_head {
+ struct rhash_head rhead;
+ struct rhlist_head __rcu *next;
+};
+
/**
* struct bucket_table - Table of hash buckets
* @size: Number of hash buckets
@@ -137,6 +142,7 @@ struct rhashtable_params {
* @key_len: Key length for hashfn
* @elasticity: Maximum chain length before rehash
* @p: Configuration parameters
+ * @rhlist: True if this is an rhltable
* @run_work: Deferred worker to expand/shrink asynchronously
* @mutex: Mutex to protect current/future table swapping
* @lock: Spin lock to protect walker list
@@ -147,12 +153,21 @@ struct rhashtable {
unsigned int key_len;
unsigned int elasticity;
struct rhashtable_params p;
+ bool rhlist;
struct work_struct run_work;
struct mutex mutex;
spinlock_t lock;
};
/**
+ * struct rhltable - Hash table with duplicate objects in a list
+ * @ht: Underlying rhtable
+ */
+struct rhltable {
+ struct rhashtable ht;
+};
+
+/**
* struct rhashtable_walker - Hash table walker
* @list: List entry on list of walkers
* @tbl: The table that we were walking over
@@ -163,9 +178,10 @@ struct rhashtable_walker {
};
/**
- * struct rhashtable_iter - Hash table iterator, fits into netlink cb
+ * struct rhashtable_iter - Hash table iterator
* @ht: Table to iterate through
* @p: Current pointer
+ * @list: Current hash list pointer
* @walker: Associated rhashtable walker
* @slot: Current slot
* @skip: Number of entries to skip in slot
@@ -173,7 +189,8 @@ struct rhashtable_walker {
struct rhashtable_iter {
struct rhashtable *ht;
struct rhash_head *p;
- struct rhashtable_walker *walker;
+ struct rhlist_head *list;
+ struct rhashtable_walker walker;
unsigned int slot;
unsigned int skip;
};
@@ -339,15 +356,14 @@ static inline int lockdep_rht_bucket_is_held(const struct bucket_table *tbl,
int rhashtable_init(struct rhashtable *ht,
const struct rhashtable_params *params);
+int rhltable_init(struct rhltable *hlt,
+ const struct rhashtable_params *params);
-struct bucket_table *rhashtable_insert_slow(struct rhashtable *ht,
- const void *key,
- struct rhash_head *obj,
- struct bucket_table *old_tbl);
-int rhashtable_insert_rehash(struct rhashtable *ht, struct bucket_table *tbl);
+void *rhashtable_insert_slow(struct rhashtable *ht, const void *key,
+ struct rhash_head *obj);
-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);
@@ -506,6 +522,31 @@ void rhashtable_destroy(struct rhashtable *ht);
rht_for_each_entry_rcu_continue(tpos, pos, (tbl)->buckets[hash],\
tbl, hash, member)
+/**
+ * rhl_for_each_rcu - iterate over rcu hash table list
+ * @pos: the &struct rlist_head to use as a loop cursor.
+ * @list: the head of the list
+ *
+ * This hash chain list-traversal primitive should be used on the
+ * list returned by rhltable_lookup.
+ */
+#define rhl_for_each_rcu(pos, list) \
+ for (pos = list; pos; pos = rcu_dereference_raw(pos->next))
+
+/**
+ * rhl_for_each_entry_rcu - iterate over rcu hash table list of given type
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rlist_head to use as a loop cursor.
+ * @list: the head of the list
+ * @member: name of the &struct rlist_head within the hashable struct.
+ *
+ * This hash chain list-traversal primitive should be used on the
+ * list returned by rhltable_lookup.
+ */
+#define rhl_for_each_entry_rcu(tpos, pos, list, member) \
+ for (pos = list; pos && rht_entry(tpos, pos, member); \
+ pos = rcu_dereference_raw(pos->next))
+
static inline int rhashtable_compare(struct rhashtable_compare_arg *arg,
const void *obj)
{
@@ -515,18 +556,8 @@ static inline int rhashtable_compare(struct rhashtable_compare_arg *arg,
return memcmp(ptr + ht->p.key_offset, arg->key, ht->p.key_len);
}
-/**
- * rhashtable_lookup_fast - search hash table, inlined version
- * @ht: hash table
- * @key: the pointer to the key
- * @params: hash table parameters
- *
- * Computes the hash value for the key and traverses the bucket chain looking
- * for a entry with an identical key. The first matching entry is returned.
- *
- * Returns the first entry on which the compare function returned true.
- */
-static inline void *rhashtable_lookup_fast(
+/* Internal function, do not use. */
+static inline struct rhash_head *__rhashtable_lookup(
struct rhashtable *ht, const void *key,
const struct rhashtable_params params)
{
@@ -538,8 +569,6 @@ static inline void *rhashtable_lookup_fast(
struct rhash_head *he;
unsigned int hash;
- rcu_read_lock();
-
tbl = rht_dereference_rcu(ht->tbl, ht);
restart:
hash = rht_key_hashfn(ht, tbl, key, params);
@@ -548,8 +577,7 @@ restart:
params.obj_cmpfn(&arg, rht_obj(ht, he)) :
rhashtable_compare(&arg, rht_obj(ht, he)))
continue;
- rcu_read_unlock();
- return rht_obj(ht, he);
+ return he;
}
/* Ensure we see any new tables. */
@@ -558,89 +586,165 @@ restart:
tbl = rht_dereference_rcu(tbl->future_tbl, ht);
if (unlikely(tbl))
goto restart;
- rcu_read_unlock();
return NULL;
}
-/* Internal function, please use rhashtable_insert_fast() instead */
-static inline int __rhashtable_insert_fast(
- struct rhashtable *ht, const void *key, struct rhash_head *obj,
+/**
+ * rhashtable_lookup - search hash table
+ * @ht: hash table
+ * @key: the pointer to the key
+ * @params: hash table parameters
+ *
+ * Computes the hash value for the key and traverses the bucket chain looking
+ * for a entry with an identical key. The first matching entry is returned.
+ *
+ * This must only be called under the RCU read lock.
+ *
+ * Returns the first entry on which the compare function returned true.
+ */
+static inline void *rhashtable_lookup(
+ struct rhashtable *ht, const void *key,
const struct rhashtable_params params)
{
+ struct rhash_head *he = __rhashtable_lookup(ht, key, params);
+
+ return he ? rht_obj(ht, he) : NULL;
+}
+
+/**
+ * rhashtable_lookup_fast - search hash table, without RCU read lock
+ * @ht: hash table
+ * @key: the pointer to the key
+ * @params: hash table parameters
+ *
+ * Computes the hash value for the key and traverses the bucket chain looking
+ * for a entry with an identical key. The first matching entry is returned.
+ *
+ * Only use this function when you have other mechanisms guaranteeing
+ * that the object won't go away after the RCU read lock is released.
+ *
+ * Returns the first entry on which the compare function returned true.
+ */
+static inline void *rhashtable_lookup_fast(
+ struct rhashtable *ht, const void *key,
+ const struct rhashtable_params params)
+{
+ void *obj;
+
+ rcu_read_lock();
+ obj = rhashtable_lookup(ht, key, params);
+ rcu_read_unlock();
+
+ return obj;
+}
+
+/**
+ * rhltable_lookup - search hash list table
+ * @hlt: hash table
+ * @key: the pointer to the key
+ * @params: hash table parameters
+ *
+ * Computes the hash value for the key and traverses the bucket chain looking
+ * for a entry with an identical key. All matching entries are returned
+ * in a list.
+ *
+ * This must only be called under the RCU read lock.
+ *
+ * Returns the list of entries that match the given key.
+ */
+static inline struct rhlist_head *rhltable_lookup(
+ struct rhltable *hlt, const void *key,
+ const struct rhashtable_params params)
+{
+ struct rhash_head *he = __rhashtable_lookup(&hlt->ht, key, params);
+
+ return he ? container_of(he, struct rhlist_head, rhead) : NULL;
+}
+
+/* Internal function, please use rhashtable_insert_fast() instead. This
+ * function returns the existing element already in hashes in there is a clash,
+ * otherwise it returns an error via ERR_PTR().
+ */
+static inline void *__rhashtable_insert_fast(
+ struct rhashtable *ht, const void *key, struct rhash_head *obj,
+ const struct rhashtable_params params, bool rhlist)
+{
struct rhashtable_compare_arg arg = {
.ht = ht,
.key = key,
};
- struct bucket_table *tbl, *new_tbl;
+ struct rhash_head __rcu **pprev;
+ struct bucket_table *tbl;
struct rhash_head *head;
spinlock_t *lock;
- unsigned int elasticity;
unsigned int hash;
- int err;
+ int elasticity;
+ void *data;
-restart:
rcu_read_lock();
tbl = rht_dereference_rcu(ht->tbl, ht);
+ hash = rht_head_hashfn(ht, tbl, obj, params);
+ lock = rht_bucket_lock(tbl, hash);
+ spin_lock_bh(lock);
- /* All insertions must grab the oldest table containing
- * the hashed bucket that is yet to be rehashed.
- */
- for (;;) {
- hash = rht_head_hashfn(ht, tbl, obj, params);
- lock = rht_bucket_lock(tbl, hash);
- spin_lock_bh(lock);
-
- if (tbl->rehash <= hash)
- break;
-
- spin_unlock_bh(lock);
- tbl = rht_dereference_rcu(tbl->future_tbl, ht);
- }
-
- new_tbl = rht_dereference_rcu(tbl->future_tbl, ht);
- if (unlikely(new_tbl)) {
- tbl = rhashtable_insert_slow(ht, key, obj, new_tbl);
- if (!IS_ERR_OR_NULL(tbl))
- goto slow_path;
-
- err = PTR_ERR(tbl);
- goto out;
- }
-
- err = -E2BIG;
- if (unlikely(rht_grow_above_max(ht, tbl)))
- goto out;
-
- if (unlikely(rht_grow_above_100(ht, tbl))) {
+ if (unlikely(rht_dereference_bucket(tbl->future_tbl, tbl, hash))) {
slow_path:
spin_unlock_bh(lock);
- err = rhashtable_insert_rehash(ht, tbl);
rcu_read_unlock();
- if (err)
- return err;
-
- goto restart;
+ return rhashtable_insert_slow(ht, key, obj);
}
- err = -EEXIST;
elasticity = ht->elasticity;
+ pprev = &tbl->buckets[hash];
rht_for_each(head, tbl, hash) {
- if (key &&
- unlikely(!(params.obj_cmpfn ?
- params.obj_cmpfn(&arg, rht_obj(ht, head)) :
- rhashtable_compare(&arg, rht_obj(ht, head)))))
+ struct rhlist_head *plist;
+ struct rhlist_head *list;
+
+ elasticity--;
+ if (!key ||
+ (params.obj_cmpfn ?
+ params.obj_cmpfn(&arg, rht_obj(ht, head)) :
+ rhashtable_compare(&arg, rht_obj(ht, head))))
+ continue;
+
+ data = rht_obj(ht, head);
+
+ if (!rhlist)
goto out;
- if (!--elasticity)
- goto slow_path;
+
+
+ list = container_of(obj, struct rhlist_head, rhead);
+ plist = container_of(head, struct rhlist_head, rhead);
+
+ RCU_INIT_POINTER(list->next, plist);
+ head = rht_dereference_bucket(head->next, tbl, hash);
+ RCU_INIT_POINTER(list->rhead.next, head);
+ rcu_assign_pointer(*pprev, obj);
+
+ goto good;
}
- err = 0;
+ if (elasticity <= 0)
+ goto slow_path;
+
+ data = ERR_PTR(-E2BIG);
+ if (unlikely(rht_grow_above_max(ht, tbl)))
+ goto out;
+
+ if (unlikely(rht_grow_above_100(ht, tbl)))
+ goto slow_path;
head = rht_dereference_bucket(tbl->buckets[hash], tbl, hash);
RCU_INIT_POINTER(obj->next, head);
+ if (rhlist) {
+ struct rhlist_head *list;
+
+ list = container_of(obj, struct rhlist_head, rhead);
+ RCU_INIT_POINTER(list->next, NULL);
+ }
rcu_assign_pointer(tbl->buckets[hash], obj);
@@ -648,11 +752,14 @@ slow_path:
if (rht_grow_above_75(ht, tbl))
schedule_work(&ht->run_work);
+good:
+ data = NULL;
+
out:
spin_unlock_bh(lock);
rcu_read_unlock();
- return err;
+ return data;
}
/**
@@ -675,7 +782,65 @@ static inline int rhashtable_insert_fast(
struct rhashtable *ht, struct rhash_head *obj,
const struct rhashtable_params params)
{
- return __rhashtable_insert_fast(ht, NULL, obj, params);
+ void *ret;
+
+ ret = __rhashtable_insert_fast(ht, NULL, obj, params, false);
+ if (IS_ERR(ret))
+ return PTR_ERR(ret);
+
+ return ret == NULL ? 0 : -EEXIST;
+}
+
+/**
+ * rhltable_insert_key - insert object into hash list table
+ * @hlt: hash list table
+ * @key: the pointer to the key
+ * @list: pointer to hash list head inside object
+ * @params: hash table parameters
+ *
+ * Will take a per bucket spinlock to protect against mutual mutations
+ * on the same bucket. Multiple insertions may occur in parallel unless
+ * they map to the same bucket lock.
+ *
+ * It is safe to call this function from atomic context.
+ *
+ * Will trigger an automatic deferred table resizing if the size grows
+ * beyond the watermark indicated by grow_decision() which can be passed
+ * to rhashtable_init().
+ */
+static inline int rhltable_insert_key(
+ struct rhltable *hlt, const void *key, struct rhlist_head *list,
+ const struct rhashtable_params params)
+{
+ return PTR_ERR(__rhashtable_insert_fast(&hlt->ht, key, &list->rhead,
+ params, true));
+}
+
+/**
+ * rhltable_insert - insert object into hash list table
+ * @hlt: hash list table
+ * @list: pointer to hash list head inside object
+ * @params: hash table parameters
+ *
+ * Will take a per bucket spinlock to protect against mutual mutations
+ * on the same bucket. Multiple insertions may occur in parallel unless
+ * they map to the same bucket lock.
+ *
+ * It is safe to call this function from atomic context.
+ *
+ * Will trigger an automatic deferred table resizing if the size grows
+ * beyond the watermark indicated by grow_decision() which can be passed
+ * to rhashtable_init().
+ */
+static inline int rhltable_insert(
+ struct rhltable *hlt, struct rhlist_head *list,
+ const struct rhashtable_params params)
+{
+ const char *key = rht_obj(&hlt->ht, &list->rhead);
+
+ key += params.key_offset;
+
+ return rhltable_insert_key(hlt, key, list, params);
}
/**
@@ -704,11 +869,16 @@ static inline int rhashtable_lookup_insert_fast(
const struct rhashtable_params params)
{
const char *key = rht_obj(ht, obj);
+ void *ret;
BUG_ON(ht->p.obj_hashfn);
- return __rhashtable_insert_fast(ht, key + ht->p.key_offset, obj,
- params);
+ ret = __rhashtable_insert_fast(ht, key + ht->p.key_offset, obj, params,
+ false);
+ if (IS_ERR(ret))
+ return PTR_ERR(ret);
+
+ return ret == NULL ? 0 : -EEXIST;
}
/**
@@ -737,15 +907,42 @@ static inline int rhashtable_lookup_insert_key(
struct rhashtable *ht, const void *key, struct rhash_head *obj,
const struct rhashtable_params params)
{
+ void *ret;
+
+ BUG_ON(!ht->p.obj_hashfn || !key);
+
+ ret = __rhashtable_insert_fast(ht, key, obj, params, false);
+ if (IS_ERR(ret))
+ return PTR_ERR(ret);
+
+ return ret == NULL ? 0 : -EEXIST;
+}
+
+/**
+ * rhashtable_lookup_get_insert_key - lookup and insert object into hash table
+ * @ht: hash table
+ * @obj: pointer to hash head inside object
+ * @params: hash table parameters
+ * @data: pointer to element data already in hashes
+ *
+ * Just like rhashtable_lookup_insert_key(), but this function returns the
+ * object if it exists, NULL if it does not and the insertion was successful,
+ * and an ERR_PTR otherwise.
+ */
+static inline void *rhashtable_lookup_get_insert_key(
+ struct rhashtable *ht, const void *key, struct rhash_head *obj,
+ const struct rhashtable_params params)
+{
BUG_ON(!ht->p.obj_hashfn || !key);
- return __rhashtable_insert_fast(ht, key, obj, params);
+ return __rhashtable_insert_fast(ht, key, obj, params, false);
}
/* Internal function, please use rhashtable_remove_fast() instead */
-static inline int __rhashtable_remove_fast(
+static inline int __rhashtable_remove_fast_one(
struct rhashtable *ht, struct bucket_table *tbl,
- struct rhash_head *obj, const struct rhashtable_params params)
+ struct rhash_head *obj, const struct rhashtable_params params,
+ bool rhlist)
{
struct rhash_head __rcu **pprev;
struct rhash_head *he;
@@ -760,39 +957,66 @@ static inline int __rhashtable_remove_fast(
pprev = &tbl->buckets[hash];
rht_for_each(he, tbl, hash) {
+ struct rhlist_head *list;
+
+ list = container_of(he, struct rhlist_head, rhead);
+
if (he != obj) {
+ struct rhlist_head __rcu **lpprev;
+
pprev = &he->next;
- continue;
+
+ if (!rhlist)
+ continue;
+
+ do {
+ lpprev = &list->next;
+ list = rht_dereference_bucket(list->next,
+ tbl, hash);
+ } while (list && obj != &list->rhead);
+
+ if (!list)
+ continue;
+
+ list = rht_dereference_bucket(list->next, tbl, hash);
+ RCU_INIT_POINTER(*lpprev, list);
+ err = 0;
+ break;
}
- rcu_assign_pointer(*pprev, obj->next);
- err = 0;
+ obj = rht_dereference_bucket(obj->next, tbl, hash);
+ err = 1;
+
+ if (rhlist) {
+ list = rht_dereference_bucket(list->next, tbl, hash);
+ if (list) {
+ RCU_INIT_POINTER(list->rhead.next, obj);
+ obj = &list->rhead;
+ err = 0;
+ }
+ }
+
+ rcu_assign_pointer(*pprev, obj);
break;
}
spin_unlock_bh(lock);
+ if (err > 0) {
+ atomic_dec(&ht->nelems);
+ if (unlikely(ht->p.automatic_shrinking &&
+ rht_shrink_below_30(ht, tbl)))
+ schedule_work(&ht->run_work);
+ err = 0;
+ }
+
return err;
}
-/**
- * rhashtable_remove_fast - remove object from hash table
- * @ht: hash table
- * @obj: pointer to hash head inside object
- * @params: hash table parameters
- *
- * Since the hash chain is single linked, the removal operation needs to
- * walk the bucket chain upon removal. The removal operation is thus
- * considerable slow if the hash table is not correctly sized.
- *
- * Will automatically shrink the table via rhashtable_expand() if the
- * shrink_decision function specified at rhashtable_init() returns true.
- *
- * Returns zero on success, -ENOENT if the entry could not be found.
- */
-static inline int rhashtable_remove_fast(
+/* Internal function, please use rhashtable_remove_fast() instead */
+static inline int __rhashtable_remove_fast(
struct rhashtable *ht, struct rhash_head *obj,
- const struct rhashtable_params params)
+ const struct rhashtable_params params, bool rhlist)
{
struct bucket_table *tbl;
int err;
@@ -806,24 +1030,60 @@ static inline int rhashtable_remove_fast(
* visible then that guarantees the entry to still be in
* the old tbl if it exists.
*/
- while ((err = __rhashtable_remove_fast(ht, tbl, obj, params)) &&
+ while ((err = __rhashtable_remove_fast_one(ht, tbl, obj, params,
+ rhlist)) &&
(tbl = rht_dereference_rcu(tbl->future_tbl, ht)))
;
- if (err)
- goto out;
-
- atomic_dec(&ht->nelems);
- if (unlikely(ht->p.automatic_shrinking &&
- rht_shrink_below_30(ht, tbl)))
- schedule_work(&ht->run_work);
-
-out:
rcu_read_unlock();
return err;
}
+/**
+ * rhashtable_remove_fast - remove object from hash table
+ * @ht: hash table
+ * @obj: pointer to hash head inside object
+ * @params: hash table parameters
+ *
+ * Since the hash chain is single linked, the removal operation needs to
+ * walk the bucket chain upon removal. The removal operation is thus
+ * considerable slow if the hash table is not correctly sized.
+ *
+ * Will automatically shrink the table via rhashtable_expand() if the
+ * shrink_decision function specified at rhashtable_init() returns true.
+ *
+ * Returns zero on success, -ENOENT if the entry could not be found.
+ */
+static inline int rhashtable_remove_fast(
+ struct rhashtable *ht, struct rhash_head *obj,
+ const struct rhashtable_params params)
+{
+ return __rhashtable_remove_fast(ht, obj, params, false);
+}
+
+/**
+ * rhltable_remove - remove object from hash list table
+ * @hlt: hash list table
+ * @list: pointer to hash list head inside object
+ * @params: hash table parameters
+ *
+ * Since the hash chain is single linked, the removal operation needs to
+ * walk the bucket chain upon removal. The removal operation is thus
+ * considerable slow if the hash table is not correctly sized.
+ *
+ * Will automatically shrink the table via rhashtable_expand() if the
+ * shrink_decision function specified at rhashtable_init() returns true.
+ *
+ * Returns zero on success, -ENOENT if the entry could not be found.
+ */
+static inline int rhltable_remove(
+ struct rhltable *hlt, struct rhlist_head *list,
+ const struct rhashtable_params params)
+{
+ return __rhashtable_remove_fast(&hlt->ht, &list->rhead, params, true);
+}
+
/* Internal function, please use rhashtable_replace_fast() instead */
static inline int __rhashtable_replace_fast(
struct rhashtable *ht, struct bucket_table *tbl,
@@ -906,4 +1166,59 @@ 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;
+}
+
+/**
+ * rhltable_walk_enter - Initialise an iterator
+ * @hlt: Table to walk over
+ * @iter: Hash table Iterator
+ *
+ * This function prepares a hash table walk.
+ *
+ * Note that if you restart a walk after rhashtable_walk_stop you
+ * may see the same object twice. Also, you may miss objects if
+ * there are removals in between rhashtable_walk_stop and the next
+ * call to rhashtable_walk_start.
+ *
+ * For a completely stable walk you should construct your own data
+ * structure outside the hash table.
+ *
+ * This function may sleep so you must not call it from interrupt
+ * context or with spin locks held.
+ *
+ * You must call rhashtable_walk_exit after this function returns.
+ */
+static inline void rhltable_walk_enter(struct rhltable *hlt,
+ struct rhashtable_iter *iter)
+{
+ return rhashtable_walk_enter(&hlt->ht, iter);
+}
+
+/**
+ * rhltable_free_and_destroy - free elements and destroy hash list table
+ * @hlt: the hash list table to destroy
+ * @free_fn: callback to release resources of element
+ * @arg: pointer passed to free_fn
+ *
+ * See documentation for rhashtable_free_and_destroy.
+ */
+static inline void rhltable_free_and_destroy(struct rhltable *hlt,
+ void (*free_fn)(void *ptr,
+ void *arg),
+ void *arg)
+{
+ return rhashtable_free_and_destroy(&hlt->ht, free_fn, arg);
+}
+
+static inline void rhltable_destroy(struct rhltable *hlt)
+{
+ return rhltable_free_and_destroy(hlt, NULL, NULL);
+}
+
#endif /* _LINUX_RHASHTABLE_H */