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authorLinus Torvalds <torvalds@linux-foundation.org>2015-02-10 20:01:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-10 20:01:30 -0800
commitc5ce28df0e7c01a1de23c36ebdefcd803f2b6cbb (patch)
tree9830baf38832769e1cf621708889111bbe3c93df /include/linux/rhashtable.h
parent29afc4e9a408f2304e09c6dd0dbcfbd2356d0faa (diff)
parent9399f0c51489ae8c16d6559b82a452fdc1895e91 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: 1) More iov_iter conversion work from Al Viro. [ The "crypto: switch af_alg_make_sg() to iov_iter" commit was wrong, and this pull actually adds an extra commit on top of the branch I'm pulling to fix that up, so that the pre-merge state is ok. - Linus ] 2) Various optimizations to the ipv4 forwarding information base trie lookup implementation. From Alexander Duyck. 3) Remove sock_iocb altogether, from CHristoph Hellwig. 4) Allow congestion control algorithm selection via routing metrics. From Daniel Borkmann. 5) Make ipv4 uncached route list per-cpu, from Eric Dumazet. 6) Handle rfs hash collisions more gracefully, also from Eric Dumazet. 7) Add xmit_more support to r8169, e1000, and e1000e drivers. From Florian Westphal. 8) Transparent Ethernet Bridging support for GRO, from Jesse Gross. 9) Add BPF packet actions to packet scheduler, from Jiri Pirko. 10) Add support for uniqu flow IDs to openvswitch, from Joe Stringer. 11) New NetCP ethernet driver, from Muralidharan Karicheri and Wingman Kwok. 12) More sanely handle out-of-window dupacks, which can result in serious ACK storms. From Neal Cardwell. 13) Various rhashtable bug fixes and enhancements, from Herbert Xu, Patrick McHardy, and Thomas Graf. 14) Support xmit_more in be2net, from Sathya Perla. 15) Group Policy extensions for vxlan, from Thomas Graf. 16) Remove Checksum Offload support for vxlan, from Tom Herbert. 17) Like ipv4, support lockless transmit over ipv6 UDP sockets. From Vlad Yasevich. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1494+1 commits) crypto: fix af_alg_make_sg() conversion to iov_iter ipv4: Namespecify TCP PMTU mechanism i40e: Fix for stats init function call in Rx setup tcp: don't include Fast Open option in SYN-ACK on pure SYN-data openvswitch: Only set TUNNEL_VXLAN_OPT if VXLAN-GBP metadata is set ipv6: Make __ipv6_select_ident static ipv6: Fix fragment id assignment on LE arches. bridge: Fix inability to add non-vlan fdb entry net: Mellanox: Delete unnecessary checks before the function call "vunmap" cxgb4: Add support in cxgb4 to get expansion rom version via ethtool ethtool: rename reserved1 memeber in ethtool_drvinfo for expansion ROM version net: dsa: Remove redundant phy_attach() IB/mlx4: Reset flow support for IB kernel ULPs IB/mlx4: Always use the correct port for mirrored multicast attachments net/bonding: Fix potential bad memory access during bonding events tipc: remove tipc_snprintf tipc: nl compat add noop and remove legacy nl framework tipc: convert legacy nl stats show to nl compat tipc: convert legacy nl net id get to nl compat tipc: convert legacy nl net id set to nl compat ...
Diffstat (limited to 'include/linux/rhashtable.h')
-rw-r--r--include/linux/rhashtable.h308
1 files changed, 231 insertions, 77 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index b93fd89b2e5e..58851275fed9 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -18,16 +18,45 @@
#ifndef _LINUX_RHASHTABLE_H
#define _LINUX_RHASHTABLE_H
-#include <linux/rculist.h>
+#include <linux/compiler.h>
+#include <linux/list_nulls.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.h>
+
+/*
+ * The end of the chain is marked with a special nulls marks which has
+ * the following format:
+ *
+ * +-------+-----------------------------------------------------+-+
+ * | Base | Hash |1|
+ * +-------+-----------------------------------------------------+-+
+ *
+ * Base (4 bits) : Reserved to distinguish between multiple tables.
+ * Specified via &struct rhashtable_params.nulls_base.
+ * Hash (27 bits): Full hash (unmasked) of first element added to bucket
+ * 1 (1 bit) : Nulls marker (always set)
+ *
+ * The remaining bits of the next pointer remain unused for now.
+ */
+#define RHT_BASE_BITS 4
+#define RHT_HASH_BITS 27
+#define RHT_BASE_SHIFT RHT_HASH_BITS
struct rhash_head {
struct rhash_head __rcu *next;
};
-#define INIT_HASH_HEAD(ptr) ((ptr)->next = NULL)
-
+/**
+ * struct bucket_table - Table of hash buckets
+ * @size: Number of hash buckets
+ * @locks_mask: Mask to apply before accessing locks[]
+ * @locks: Array of spinlocks protecting individual buckets
+ * @buckets: size * hash buckets
+ */
struct bucket_table {
size_t size;
+ unsigned int locks_mask;
+ spinlock_t *locks;
struct rhash_head __rcu *buckets[];
};
@@ -45,11 +74,16 @@ struct rhashtable;
* @hash_rnd: Seed to use while hashing
* @max_shift: Maximum number of shifts while expanding
* @min_shift: Minimum number of shifts while shrinking
+ * @nulls_base: Base value to generate nulls marker
+ * @locks_mul: Number of bucket locks to allocate per cpu (default: 128)
* @hashfn: Function to hash key
* @obj_hashfn: Function to hash object
* @grow_decision: If defined, may return true if table should expand
* @shrink_decision: If defined, may return true if table should shrink
- * @mutex_is_held: Must return true if protecting mutex is held
+ *
+ * Note: when implementing the grow and shrink decision function, min/max
+ * shift must be enforced, otherwise, resizing watermarks they set may be
+ * useless.
*/
struct rhashtable_params {
size_t nelem_hint;
@@ -59,36 +93,95 @@ struct rhashtable_params {
u32 hash_rnd;
size_t max_shift;
size_t min_shift;
+ u32 nulls_base;
+ size_t locks_mul;
rht_hashfn_t hashfn;
rht_obj_hashfn_t obj_hashfn;
bool (*grow_decision)(const struct rhashtable *ht,
size_t new_size);
bool (*shrink_decision)(const struct rhashtable *ht,
size_t new_size);
-#ifdef CONFIG_PROVE_LOCKING
- int (*mutex_is_held)(void *parent);
- void *parent;
-#endif
};
/**
* struct rhashtable - Hash table handle
* @tbl: Bucket table
+ * @future_tbl: Table under construction during expansion/shrinking
* @nelems: Number of elements in table
* @shift: Current size (1 << shift)
* @p: Configuration parameters
+ * @run_work: Deferred worker to expand/shrink asynchronously
+ * @mutex: Mutex to protect current/future table swapping
+ * @walkers: List of active walkers
+ * @being_destroyed: True if table is set up for destruction
*/
struct rhashtable {
struct bucket_table __rcu *tbl;
- size_t nelems;
- size_t shift;
+ struct bucket_table __rcu *future_tbl;
+ atomic_t nelems;
+ atomic_t shift;
struct rhashtable_params p;
+ struct work_struct run_work;
+ struct mutex mutex;
+ struct list_head walkers;
+ bool being_destroyed;
+};
+
+/**
+ * struct rhashtable_walker - Hash table walker
+ * @list: List entry on list of walkers
+ * @resize: Resize event occured
+ */
+struct rhashtable_walker {
+ struct list_head list;
+ bool resize;
};
+/**
+ * struct rhashtable_iter - Hash table iterator, fits into netlink cb
+ * @ht: Table to iterate through
+ * @p: Current pointer
+ * @walker: Associated rhashtable walker
+ * @slot: Current slot
+ * @skip: Number of entries to skip in slot
+ */
+struct rhashtable_iter {
+ struct rhashtable *ht;
+ struct rhash_head *p;
+ struct rhashtable_walker *walker;
+ unsigned int slot;
+ unsigned int skip;
+};
+
+static inline unsigned long rht_marker(const struct rhashtable *ht, u32 hash)
+{
+ return NULLS_MARKER(ht->p.nulls_base + hash);
+}
+
+#define INIT_RHT_NULLS_HEAD(ptr, ht, hash) \
+ ((ptr) = (typeof(ptr)) rht_marker(ht, hash))
+
+static inline bool rht_is_a_nulls(const struct rhash_head *ptr)
+{
+ return ((unsigned long) ptr & 1);
+}
+
+static inline unsigned long rht_get_nulls_value(const struct rhash_head *ptr)
+{
+ return ((unsigned long) ptr) >> 1;
+}
+
#ifdef CONFIG_PROVE_LOCKING
-int lockdep_rht_mutex_is_held(const struct rhashtable *ht);
+int lockdep_rht_mutex_is_held(struct rhashtable *ht);
+int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, u32 hash);
#else
-static inline int lockdep_rht_mutex_is_held(const struct rhashtable *ht)
+static inline int lockdep_rht_mutex_is_held(struct rhashtable *ht)
+{
+ return 1;
+}
+
+static inline int lockdep_rht_bucket_is_held(const struct bucket_table *tbl,
+ u32 hash)
{
return 1;
}
@@ -96,13 +189,8 @@ static inline int lockdep_rht_mutex_is_held(const struct rhashtable *ht)
int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params);
-u32 rhashtable_hashfn(const struct rhashtable *ht, const void *key, u32 len);
-u32 rhashtable_obj_hashfn(const struct rhashtable *ht, void *ptr);
-
void rhashtable_insert(struct rhashtable *ht, struct rhash_head *node);
bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *node);
-void rhashtable_remove_pprev(struct rhashtable *ht, struct rhash_head *obj,
- struct rhash_head __rcu **pprev);
bool rht_grow_above_75(const struct rhashtable *ht, size_t new_size);
bool rht_shrink_below_30(const struct rhashtable *ht, size_t new_size);
@@ -110,11 +198,23 @@ bool rht_shrink_below_30(const struct rhashtable *ht, size_t new_size);
int rhashtable_expand(struct rhashtable *ht);
int rhashtable_shrink(struct rhashtable *ht);
-void *rhashtable_lookup(const struct rhashtable *ht, const void *key);
-void *rhashtable_lookup_compare(const struct rhashtable *ht, u32 hash,
+void *rhashtable_lookup(struct rhashtable *ht, const void *key);
+void *rhashtable_lookup_compare(struct rhashtable *ht, const void *key,
bool (*compare)(void *, void *), void *arg);
-void rhashtable_destroy(const struct rhashtable *ht);
+bool rhashtable_lookup_insert(struct rhashtable *ht, struct rhash_head *obj);
+bool rhashtable_lookup_compare_insert(struct rhashtable *ht,
+ struct rhash_head *obj,
+ bool (*compare)(void *, void *),
+ void *arg);
+
+int rhashtable_walk_init(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);
+void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases(RCU);
+
+void rhashtable_destroy(struct rhashtable *ht);
#define rht_dereference(p, ht) \
rcu_dereference_protected(p, lockdep_rht_mutex_is_held(ht))
@@ -122,92 +222,146 @@ void rhashtable_destroy(const struct rhashtable *ht);
#define rht_dereference_rcu(p, ht) \
rcu_dereference_check(p, lockdep_rht_mutex_is_held(ht))
-#define rht_entry(ptr, type, member) container_of(ptr, type, member)
-#define rht_entry_safe(ptr, type, member) \
-({ \
- typeof(ptr) __ptr = (ptr); \
- __ptr ? rht_entry(__ptr, type, member) : NULL; \
-})
+#define rht_dereference_bucket(p, tbl, hash) \
+ rcu_dereference_protected(p, lockdep_rht_bucket_is_held(tbl, hash))
+
+#define rht_dereference_bucket_rcu(p, tbl, hash) \
+ rcu_dereference_check(p, lockdep_rht_bucket_is_held(tbl, hash))
-#define rht_next_entry_safe(pos, ht, member) \
-({ \
- pos ? rht_entry_safe(rht_dereference((pos)->member.next, ht), \
- typeof(*(pos)), member) : NULL; \
-})
+#define rht_entry(tpos, pos, member) \
+ ({ tpos = container_of(pos, typeof(*tpos), member); 1; })
+
+/**
+ * rht_for_each_continue - continue iterating over hash chain
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @head: the previous &struct rhash_head to continue from
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ */
+#define rht_for_each_continue(pos, head, tbl, hash) \
+ for (pos = rht_dereference_bucket(head, tbl, hash); \
+ !rht_is_a_nulls(pos); \
+ pos = rht_dereference_bucket((pos)->next, tbl, hash))
/**
* rht_for_each - iterate over hash chain
- * @pos: &struct rhash_head to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
*/
-#define rht_for_each(pos, head, ht) \
- for (pos = rht_dereference(head, ht); \
- pos; \
- pos = rht_dereference((pos)->next, ht))
+#define rht_for_each(pos, tbl, hash) \
+ rht_for_each_continue(pos, (tbl)->buckets[hash], tbl, hash)
+
+/**
+ * rht_for_each_entry_continue - continue iterating over hash chain
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @head: the previous &struct rhash_head to continue from
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
+ */
+#define rht_for_each_entry_continue(tpos, pos, head, tbl, hash, member) \
+ for (pos = rht_dereference_bucket(head, tbl, hash); \
+ (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
+ pos = rht_dereference_bucket((pos)->next, tbl, hash))
/**
* rht_for_each_entry - iterate over hash chain of given type
- * @pos: type * to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
- * @member: name of the rhash_head within the hashable struct.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
*/
-#define rht_for_each_entry(pos, head, ht, member) \
- for (pos = rht_entry_safe(rht_dereference(head, ht), \
- typeof(*(pos)), member); \
- pos; \
- pos = rht_next_entry_safe(pos, ht, member))
+#define rht_for_each_entry(tpos, pos, tbl, hash, member) \
+ rht_for_each_entry_continue(tpos, pos, (tbl)->buckets[hash], \
+ tbl, hash, member)
/**
* rht_for_each_entry_safe - safely iterate over hash chain of given type
- * @pos: type * to use as a loop cursor.
- * @n: type * to use for temporary next object storage
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
- * @member: name of the rhash_head within the hashable struct.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @next: the &struct rhash_head to use as next in loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
*
* This hash chain list-traversal primitive allows for the looped code to
* remove the loop cursor from the list.
*/
-#define rht_for_each_entry_safe(pos, n, head, ht, member) \
- for (pos = rht_entry_safe(rht_dereference(head, ht), \
- typeof(*(pos)), member), \
- n = rht_next_entry_safe(pos, ht, member); \
- pos; \
- pos = n, \
- n = rht_next_entry_safe(pos, ht, member))
+#define rht_for_each_entry_safe(tpos, pos, next, tbl, hash, member) \
+ for (pos = rht_dereference_bucket((tbl)->buckets[hash], tbl, hash), \
+ next = !rht_is_a_nulls(pos) ? \
+ rht_dereference_bucket(pos->next, tbl, hash) : NULL; \
+ (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
+ pos = next, \
+ next = !rht_is_a_nulls(pos) ? \
+ rht_dereference_bucket(pos->next, tbl, hash) : NULL)
+
+/**
+ * rht_for_each_rcu_continue - continue iterating over rcu hash chain
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @head: the previous &struct rhash_head to continue from
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ *
+ * This hash chain list-traversal primitive may safely run concurrently with
+ * the _rcu mutation primitives such as rhashtable_insert() as long as the
+ * traversal is guarded by rcu_read_lock().
+ */
+#define rht_for_each_rcu_continue(pos, head, tbl, hash) \
+ for (({barrier(); }), \
+ pos = rht_dereference_bucket_rcu(head, tbl, hash); \
+ !rht_is_a_nulls(pos); \
+ pos = rcu_dereference_raw(pos->next))
/**
* rht_for_each_rcu - iterate over rcu hash chain
- * @pos: &struct rhash_head to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ *
+ * This hash chain list-traversal primitive may safely run concurrently with
+ * the _rcu mutation primitives such as rhashtable_insert() as long as the
+ * traversal is guarded by rcu_read_lock().
+ */
+#define rht_for_each_rcu(pos, tbl, hash) \
+ rht_for_each_rcu_continue(pos, (tbl)->buckets[hash], tbl, hash)
+
+/**
+ * rht_for_each_entry_rcu_continue - continue iterating over rcu hash chain
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @head: the previous &struct rhash_head to continue from
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
*
* This hash chain list-traversal primitive may safely run concurrently with
- * the _rcu fkht mutation primitives such as rht_insert() as long as the
+ * the _rcu mutation primitives such as rhashtable_insert() as long as the
* traversal is guarded by rcu_read_lock().
*/
-#define rht_for_each_rcu(pos, head, ht) \
- for (pos = rht_dereference_rcu(head, ht); \
- pos; \
- pos = rht_dereference_rcu((pos)->next, ht))
+#define rht_for_each_entry_rcu_continue(tpos, pos, head, tbl, hash, member) \
+ for (({barrier(); }), \
+ pos = rht_dereference_bucket_rcu(head, tbl, hash); \
+ (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
+ pos = rht_dereference_bucket_rcu(pos->next, tbl, hash))
/**
* rht_for_each_entry_rcu - iterate over rcu hash chain of given type
- * @pos: type * to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @member: name of the rhash_head within the hashable struct.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
*
* This hash chain list-traversal primitive may safely run concurrently with
- * the _rcu fkht mutation primitives such as rht_insert() as long as the
+ * the _rcu mutation primitives such as rhashtable_insert() as long as the
* traversal is guarded by rcu_read_lock().
*/
-#define rht_for_each_entry_rcu(pos, head, member) \
- for (pos = rht_entry_safe(rcu_dereference_raw(head), \
- typeof(*(pos)), member); \
- pos; \
- pos = rht_entry_safe(rcu_dereference_raw((pos)->member.next), \
- typeof(*(pos)), member))
+#define rht_for_each_entry_rcu(tpos, pos, tbl, hash, member) \
+ rht_for_each_entry_rcu_continue(tpos, pos, (tbl)->buckets[hash],\
+ tbl, hash, member)
#endif /* _LINUX_RHASHTABLE_H */