/* !(__linux__ && __KERNEL__) */
#endif
-struct cfs_hash_ops;
+/** disable debug */
+#define CFS_HASH_DEBUG_NONE 0
+/** record hash depth and output to console when it's too deep,
+ * computing overhead is low but consume more memory */
+#define CFS_HASH_DEBUG_1 1
+/** expensive, check key validation */
+#define CFS_HASH_DEBUG_2 2
+
+#define CFS_HASH_DEBUG_LEVEL CFS_HASH_DEBUG_NONE
+struct cfs_hash_ops;
+struct cfs_hash_lock_ops;
+struct cfs_hash_hlist_ops;
+
+typedef union {
+ cfs_rwlock_t rw; /**< rwlock */
+ cfs_spinlock_t spin; /**< spinlock */
+} cfs_hash_lock_t;
+
+/**
+ * cfs_hash_bucket is a container of:
+ * - lock, couter ...
+ * - array of hash-head starting from hsb_head[0], hash-head can be one of
+ * . cfs_hash_head_t
+ * . cfs_hash_head_dep_t
+ * . cfs_hash_dhead_t
+ * . cfs_hash_dhead_dep_t
+ * which depends on requirement of user
+ * - some extra bytes (caller can require it while creating hash)
+ */
typedef struct cfs_hash_bucket {
- cfs_hlist_head_t hsb_head; /* entries list */
- cfs_atomic_t hsb_count; /* current entries */
- cfs_rwlock_t hsb_rwlock; /* cfs_hash_bucket */
+ cfs_hash_lock_t hsb_lock; /**< bucket lock */
+ __u32 hsb_count; /**< current entries */
+ __u32 hsb_version; /**< change version */
+ unsigned int hsb_index; /**< index of bucket */
+ int hsb_depmax; /**< max depth on bucket */
+ char hsb_head[0]; /**< hash-head array */
} cfs_hash_bucket_t;
-#define CFS_MAX_HASH_NAME 16
+/**
+ * cfs_hash bucket descriptor, it's normally in stack of caller
+ */
+typedef struct cfs_hash_bd {
+ cfs_hash_bucket_t *bd_bucket; /**< address of bucket */
+ unsigned int bd_offset; /**< offset in bucket */
+} cfs_hash_bd_t;
+
+#define CFS_HASH_NAME_LEN 16 /**< default name length */
+#define CFS_HASH_BIGNAME_LEN 64 /**< bigname for param tree */
+
+#define CFS_HASH_BKT_BITS 3 /**< default bits of bucket */
+#define CFS_HASH_BITS_MAX 30 /**< max bits of bucket */
+#define CFS_HASH_BITS_MIN CFS_HASH_BKT_BITS
+
+/**
+ * common hash attributes.
+ */
+enum cfs_hash_tag {
+ /**
+ * don't need any lock, caller will protect operations with it's
+ * own lock. With this flag:
+ * . CFS_HASH_NO_BKTLOCK, CFS_HASH_RW_BKTLOCK, CFS_HASH_SPIN_BKTLOCK
+ * will be ignored.
+ * . Some functions will be disabled with this flag, i.e:
+ * cfs_hash_for_each_empty, cfs_hash_rehash
+ */
+ CFS_HASH_NO_LOCK = 1 << 0,
+ /** no bucket lock, use one spinlock to protect the whole hash */
+ CFS_HASH_NO_BKTLOCK = 1 << 1,
+ /** rwlock to protect bucket */
+ CFS_HASH_RW_BKTLOCK = 1 << 2,
+ /** spinlcok to protect bucket */
+ CFS_HASH_SPIN_BKTLOCK = 1 << 3,
+ /** always add new item to tail */
+ CFS_HASH_ADD_TAIL = 1 << 4,
+ /** hash-table doesn't have refcount on item */
+ CFS_HASH_NO_ITEMREF = 1 << 5,
+ /** big name for param-tree */
+ CFS_HASH_BIGNAME = 1 << 6,
+ /** track global count */
+ CFS_HASH_COUNTER = 1 << 7,
+ /** rehash item by new key */
+ CFS_HASH_REHASH_KEY = 1 << 8,
+ /** Enable dynamic hash resizing */
+ CFS_HASH_REHASH = 1 << 9,
+ /** can shrink hash-size */
+ CFS_HASH_SHRINK = 1 << 10,
+ /** assert hash is empty on exit */
+ CFS_HASH_ASSERT_EMPTY = 1 << 11,
+ /** record hlist depth */
+ CFS_HASH_DEPTH = 1 << 12,
+ /**
+ * rehash is always scheduled in a different thread, so current
+ * change on hash table is non-blocking
+ */
+ CFS_HASH_NBLK_CHANGE = 1 << 13,
+ /** NB, we typed hs_flags as __u16, please change it
+ * if you need to extend >=16 flags */
+};
+
+/** most used attributes */
+#define CFS_HASH_DEFAULT (CFS_HASH_RW_BKTLOCK | \
+ CFS_HASH_COUNTER | CFS_HASH_REHASH)
+
+/**
+ * cfs_hash is a hash-table implementation for general purpose, it can support:
+ * . two refcount modes
+ * hash-table with & without refcount
+ * . four lock modes
+ * nolock, one-spinlock, rw-bucket-lock, spin-bucket-lock
+ * . general operations
+ * lookup, add(add_tail or add_head), delete
+ * . rehash
+ * grows or shrink
+ * . iteration
+ * locked iteration and unlocked iteration
+ * . bigname
+ * support long name hash
+ * . debug
+ * trace max searching depth
+ *
+ * Rehash:
+ * When the htable grows or shrinks, a separate task (cfs_hash_rehash_worker)
+ * is spawned to handle the rehash in the background, it's possible that other
+ * processes can concurrently perform additions, deletions, and lookups
+ * without being blocked on rehash completion, because rehash will release
+ * the global wrlock for each bucket.
+ *
+ * rehash and iteration can't run at the same time because it's too tricky
+ * to keep both of them safe and correct.
+ * As they are relatively rare operations, so:
+ * . if iteration is in progress while we try to launch rehash, then
+ * it just giveup, iterator will launch rehash at the end.
+ * . if rehash is in progress while we try to iterate the hash table,
+ * then we just wait (shouldn't be very long time), anyway, nobody
+ * should expect iteration of whole hash-table to be non-blocking.
+ *
+ * During rehashing, a (key,object) pair may be in one of two buckets,
+ * depending on whether the worker task has yet to transfer the object
+ * to its new location in the table. Lookups and deletions need to search both
+ * locations; additions must take care to only insert into the new bucket.
+ */
typedef struct cfs_hash {
- int hs_cur_bits; /* current hash bits */
- int hs_cur_mask; /* current hash mask */
- int hs_min_bits; /* min hash bits */
- int hs_max_bits; /* max hash bits */
- int hs_min_theta; /* resize min threshold */
- int hs_max_theta; /* resize max threshold */
- int hs_flags; /* hash flags */
- cfs_atomic_t hs_count; /* current entries */
- cfs_atomic_t hs_rehash_count;/* resize count */
- struct cfs_hash_bucket **hs_buckets; /* hash buckets */
- struct cfs_hash_ops *hs_ops; /* hash operations */
- cfs_rwlock_t hs_rwlock; /* cfs_hash */
+ /** serialize with rehash, or serialize all operations if
+ * the hash-table has CFS_HASH_NO_BKTLOCK */
+ cfs_hash_lock_t hs_lock;
+ /** hash operations */
+ struct cfs_hash_ops *hs_ops;
+ /** hash lock operations */
+ struct cfs_hash_lock_ops *hs_lops;
+ /** hash list operations */
+ struct cfs_hash_hlist_ops *hs_hops;
+ /** hash buckets-table */
+ cfs_hash_bucket_t **hs_buckets;
+ /** total number of items on this hash-table */
+ cfs_atomic_t hs_count;
+ /** hash flags, see cfs_hash_tag for detail */
+ __u16 hs_flags;
+ /** # of extra-bytes for bucket, for user saving extended attributes */
+ __u16 hs_extra_bytes;
+ /** wants to iterate */
+ __u8 hs_iterating;
+ /** hash-table is dying */
+ __u8 hs_exiting;
+ /** current hash bits */
+ __u8 hs_cur_bits;
+ /** min hash bits */
+ __u8 hs_min_bits;
+ /** max hash bits */
+ __u8 hs_max_bits;
+ /** bits for rehash */
+ __u8 hs_rehash_bits;
+ /** bits for each bucket */
+ __u8 hs_bkt_bits;
+ /** resize min threshold */
+ __u16 hs_min_theta;
+ /** resize max threshold */
+ __u16 hs_max_theta;
+ /** resize count */
+ __u32 hs_rehash_count;
+ /** # of iterators (caller of cfs_hash_for_each_*) */
+ __u32 hs_iterators;
+ /** rehash workitem */
+ cfs_workitem_t hs_rehash_wi;
+ /** refcount on this hash table */
cfs_atomic_t hs_refcount;
- char hs_name[CFS_MAX_HASH_NAME];
+ /** rehash buckets-table */
+ cfs_hash_bucket_t **hs_rehash_buckets;
+#if CFS_HASH_DEBUG_LEVEL >= CFS_HASH_DEBUG_1
+ /** serialize debug members */
+ cfs_spinlock_t hs_dep_lock;
+ /** max depth */
+ unsigned int hs_dep_max;
+ /** id of the deepest bucket */
+ unsigned int hs_dep_bkt;
+ /** offset in the deepest bucket */
+ unsigned int hs_dep_off;
+ /** bits when we found the max depth */
+ unsigned int hs_dep_bits;
+ /** workitem to output max depth */
+ cfs_workitem_t hs_dep_wi;
+#endif
+ /** name of htable */
+ char hs_name[0];
} cfs_hash_t;
+typedef struct cfs_hash_lock_ops {
+ /** lock the hash table */
+ void (*hs_lock)(cfs_hash_lock_t *lock, int exclusive);
+ /** unlock the hash table */
+ void (*hs_unlock)(cfs_hash_lock_t *lock, int exclusive);
+ /** lock the hash bucket */
+ void (*hs_bkt_lock)(cfs_hash_lock_t *lock, int exclusive);
+ /** unlock the hash bucket */
+ void (*hs_bkt_unlock)(cfs_hash_lock_t *lock, int exclusive);
+} cfs_hash_lock_ops_t;
+
+typedef struct cfs_hash_hlist_ops {
+ /** return hlist_head of hash-head of @bd */
+ cfs_hlist_head_t *(*hop_hhead)(cfs_hash_t *hs, cfs_hash_bd_t *bd);
+ /** return hash-head size */
+ int (*hop_hhead_size)(cfs_hash_t *hs);
+ /** add @hnode to hash-head of @bd */
+ int (*hop_hnode_add)(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd, cfs_hlist_node_t *hnode);
+ /** remove @hnode from hash-head of @bd */
+ int (*hop_hnode_del)(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd, cfs_hlist_node_t *hnode);
+} cfs_hash_hlist_ops_t;
+
typedef struct cfs_hash_ops {
+ /** return hashed value from @key */
unsigned (*hs_hash)(cfs_hash_t *hs, void *key, unsigned mask);
+ /** return key address of @hnode */
void * (*hs_key)(cfs_hlist_node_t *hnode);
- int (*hs_compare)(void *key, cfs_hlist_node_t *hnode);
+ /** copy key from @hnode to @key */
+ void (*hs_keycpy)(cfs_hlist_node_t *hnode, void *key);
+ /** compare @key with key of @hnode */
+ int (*hs_keycmp)(void *key, cfs_hlist_node_t *hnode);
+ /** return object address of @hnode, i.e: container_of(...hnode) */
+ void * (*hs_object)(cfs_hlist_node_t *hnode);
+ /** get refcount of item, always called with holding bucket-lock */
void * (*hs_get)(cfs_hlist_node_t *hnode);
+ /** release refcount of item */
void * (*hs_put)(cfs_hlist_node_t *hnode);
+ /** release refcount of item, always called with holding bucket-lock */
+ void * (*hs_put_locked)(cfs_hlist_node_t *hnode);
+ /** it's called before removing of @hnode */
void (*hs_exit)(cfs_hlist_node_t *hnode);
} cfs_hash_ops_t;
-#define CFS_HASH_DEBUG 0x0001 /* Enable expensive debug checks */
-#define CFS_HASH_REHASH 0x0002 /* Enable dynamic hash resizing */
+/** total number of buckets in @hs */
+#define CFS_HASH_NBKT(hs) \
+ (1U << ((hs)->hs_cur_bits - (hs)->hs_bkt_bits))
+
+/** total number of buckets in @hs while rehashing */
+#define CFS_HASH_RH_NBKT(hs) \
+ (1U << ((hs)->hs_rehash_bits - (hs)->hs_bkt_bits))
-#define CFS_HOP(hs, op) (hs)->hs_ops->hs_ ## op
+/** number of hlist for in bucket */
+#define CFS_HASH_BKT_NHLIST(hs) (1U << (hs)->hs_bkt_bits)
+
+/** total number of hlist in @hs */
+#define CFS_HASH_NHLIST(hs) (1U << (hs)->hs_cur_bits)
+
+/** total number of hlist in @hs while rehashing */
+#define CFS_HASH_RH_NHLIST(hs) (1U << (hs)->hs_rehash_bits)
+
+static inline int
+cfs_hash_with_no_lock(cfs_hash_t *hs)
+{
+ /* caller will serialize all operations for this hash-table */
+ return (hs->hs_flags & CFS_HASH_NO_LOCK) != 0;
+}
+
+static inline int
+cfs_hash_with_no_bktlock(cfs_hash_t *hs)
+{
+ /* no bucket lock, one single lock to protect the hash-table */
+ return (hs->hs_flags & CFS_HASH_NO_BKTLOCK) != 0;
+}
+
+static inline int
+cfs_hash_with_rw_bktlock(cfs_hash_t *hs)
+{
+ /* rwlock to protect hash bucket */
+ return (hs->hs_flags & CFS_HASH_RW_BKTLOCK) != 0;
+}
+
+static inline int
+cfs_hash_with_spin_bktlock(cfs_hash_t *hs)
+{
+ /* spinlock to protect hash bucket */
+ return (hs->hs_flags & CFS_HASH_SPIN_BKTLOCK) != 0;
+}
+
+static inline int
+cfs_hash_with_add_tail(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_ADD_TAIL) != 0;
+}
+
+static inline int
+cfs_hash_with_no_itemref(cfs_hash_t *hs)
+{
+ /* hash-table doesn't keep refcount on item,
+ * item can't be removed from hash unless it's
+ * ZERO refcount */
+ return (hs->hs_flags & CFS_HASH_NO_ITEMREF) != 0;
+}
+
+static inline int
+cfs_hash_with_bigname(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_BIGNAME) != 0;
+}
+
+static inline int
+cfs_hash_with_counter(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_COUNTER) != 0;
+}
+
+static inline int
+cfs_hash_with_rehash(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_REHASH) != 0;
+}
+
+static inline int
+cfs_hash_with_rehash_key(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_REHASH_KEY) != 0;
+}
+
+static inline int
+cfs_hash_with_shrink(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_SHRINK) != 0;
+}
+
+static inline int
+cfs_hash_with_assert_empty(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_ASSERT_EMPTY) != 0;
+}
+
+static inline int
+cfs_hash_with_depth(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_DEPTH) != 0;
+}
+
+static inline int
+cfs_hash_with_nblk_change(cfs_hash_t *hs)
+{
+ return (hs->hs_flags & CFS_HASH_NBLK_CHANGE) != 0;
+}
+
+static inline int
+cfs_hash_is_exiting(cfs_hash_t *hs)
+{ /* cfs_hash_destroy is called */
+ return hs->hs_exiting;
+}
+
+static inline int
+cfs_hash_is_rehashing(cfs_hash_t *hs)
+{ /* rehash is launched */
+ return hs->hs_rehash_bits != 0;
+}
+
+static inline int
+cfs_hash_is_iterating(cfs_hash_t *hs)
+{ /* someone is calling cfs_hash_for_each_* */
+ return hs->hs_iterating || hs->hs_iterators != 0;
+}
+
+static inline int
+cfs_hash_bkt_size(cfs_hash_t *hs)
+{
+ return offsetof(cfs_hash_bucket_t, hsb_head[0]) +
+ hs->hs_hops->hop_hhead_size(hs) * CFS_HASH_BKT_NHLIST(hs) +
+ hs->hs_extra_bytes;
+}
+
+#define CFS_HOP(hs, op) (hs)->hs_ops->hs_ ## op
static inline unsigned
cfs_hash_id(cfs_hash_t *hs, void *key, unsigned mask)
return CFS_HOP(hs, key)(hnode);
}
-/* Returns TRUE on a match. */
+static inline void
+cfs_hash_keycpy(cfs_hash_t *hs, cfs_hlist_node_t *hnode, void *key)
+{
+ if (CFS_HOP(hs, keycpy) != NULL)
+ CFS_HOP(hs, keycpy)(hnode, key);
+}
+
+/**
+ * Returns 1 on a match,
+ */
static inline int
-cfs_hash_compare(cfs_hash_t *hs, void *key, cfs_hlist_node_t *hnode)
+cfs_hash_keycmp(cfs_hash_t *hs, void *key, cfs_hlist_node_t *hnode)
+{
+ return CFS_HOP(hs, keycmp)(key, hnode);
+}
+
+static inline void *
+cfs_hash_object(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
{
- return CFS_HOP(hs, compare)(key, hnode);
+ return CFS_HOP(hs, object)(hnode);
}
static inline void *
}
static inline void *
+cfs_hash_put_locked(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
+{
+ LASSERT(CFS_HOP(hs, put_locked) != NULL);
+
+ return CFS_HOP(hs, put_locked)(hnode);
+}
+
+static inline void *
cfs_hash_put(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
{
+ LASSERT(CFS_HOP(hs, put) != NULL);
+
return CFS_HOP(hs, put)(hnode);
}
static inline void
cfs_hash_exit(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
{
- /* This is allowed to be a NOOP */
- if (CFS_HOP(hs, exit) != NULL)
- return CFS_HOP(hs, exit)(hnode);
+ if (CFS_HOP(hs, exit))
+ CFS_HOP(hs, exit)(hnode);
}
-/* Validate hnode references the correct key */
-static inline void
-__cfs_hash_key_validate(cfs_hash_t *hs, void *key,
- cfs_hlist_node_t *hnode)
+static inline void cfs_hash_lock(cfs_hash_t *hs, int excl)
{
- if (unlikely(hs->hs_flags & CFS_HASH_DEBUG))
- LASSERT(cfs_hash_compare(hs, key, hnode));
+ hs->hs_lops->hs_lock(&hs->hs_lock, excl);
}
-/* Validate hnode is in the correct bucket */
-static inline void
-__cfs_hash_bucket_validate(cfs_hash_t *hs, cfs_hash_bucket_t *hsb,
- cfs_hlist_node_t *hnode)
+static inline void cfs_hash_unlock(cfs_hash_t *hs, int excl)
{
- unsigned i;
+ hs->hs_lops->hs_unlock(&hs->hs_lock, excl);
+}
- if (unlikely(hs->hs_flags & CFS_HASH_DEBUG)) {
- i = cfs_hash_id(hs, cfs_hash_key(hs, hnode), hs->hs_cur_mask);
- LASSERT(hs->hs_buckets[i] == hsb);
- }
+static inline void cfs_hash_bd_lock(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd, int excl)
+{
+ hs->hs_lops->hs_bkt_lock(&bd->bd_bucket->hsb_lock, excl);
}
-static inline cfs_hlist_node_t *
-__cfs_hash_bucket_lookup(cfs_hash_t *hs,
- cfs_hash_bucket_t *hsb, void *key)
+static inline void cfs_hash_bd_unlock(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd, int excl)
{
- cfs_hlist_node_t *hnode;
+ hs->hs_lops->hs_bkt_unlock(&bd->bd_bucket->hsb_lock, excl);
+}
- cfs_hlist_for_each(hnode, &hsb->hsb_head)
- if (cfs_hash_compare(hs, key, hnode))
- return hnode;
+/**
+ * operations on cfs_hash bucket (bd: bucket descriptor),
+ * they are normally for hash-table without rehash
+ */
+void cfs_hash_bd_get(cfs_hash_t *hs, void *key, cfs_hash_bd_t *bd);
- return NULL;
+static inline void cfs_hash_bd_get_and_lock(cfs_hash_t *hs, void *key,
+ cfs_hash_bd_t *bd, int excl)
+{
+ cfs_hash_bd_get(hs, key, bd);
+ cfs_hash_bd_lock(hs, bd, excl);
}
static inline void *
-__cfs_hash_bucket_add(cfs_hash_t *hs,
- cfs_hash_bucket_t *hsb,
- cfs_hlist_node_t *hnode)
+cfs_hash_bd_extra_get(cfs_hash_t *hs, cfs_hash_bd_t *bd)
{
- cfs_hlist_add_head(hnode, &(hsb->hsb_head));
- cfs_atomic_inc(&hsb->hsb_count);
- cfs_atomic_inc(&hs->hs_count);
+ return (void *)bd->bd_bucket +
+ cfs_hash_bkt_size(hs) - hs->hs_extra_bytes;
+}
- return cfs_hash_get(hs, hnode);
+static inline __u32
+cfs_hash_bd_version_get(cfs_hash_bd_t *bd)
+{
+ /* need hold cfs_hash_bd_lock */
+ return bd->bd_bucket->hsb_version;
}
-static inline void *
-__cfs_hash_bucket_del(cfs_hash_t *hs,
- cfs_hash_bucket_t *hsb,
- cfs_hlist_node_t *hnode)
+static inline __u32
+cfs_hash_bd_count_get(cfs_hash_bd_t *bd)
+{
+ /* need hold cfs_hash_bd_lock */
+ return bd->bd_bucket->hsb_count;
+}
+
+static inline int
+cfs_hash_bd_depmax_get(cfs_hash_bd_t *bd)
{
- cfs_hlist_del_init(hnode);
- LASSERT(cfs_atomic_read(&hsb->hsb_count) > 0);
- cfs_atomic_dec(&hsb->hsb_count);
- LASSERT(cfs_atomic_read(&hs->hs_count) > 0);
- cfs_atomic_dec(&hs->hs_count);
+ return bd->bd_bucket->hsb_depmax;
+}
+
+static inline int
+cfs_hash_bd_compare(cfs_hash_bd_t *bd1, cfs_hash_bd_t *bd2)
+{
+ if (bd1->bd_bucket->hsb_index != bd2->bd_bucket->hsb_index)
+ return bd1->bd_bucket->hsb_index - bd2->bd_bucket->hsb_index;
+
+ if (bd1->bd_offset != bd2->bd_offset)
+ return bd1->bd_offset - bd2->bd_offset;
+
+ return 0;
+}
+
+void cfs_hash_bd_add_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode);
+void cfs_hash_bd_del_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode);
+void cfs_hash_bd_move_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd_old,
+ cfs_hash_bd_t *bd_new, cfs_hlist_node_t *hnode);
+
+static inline int cfs_hash_bd_dec_and_lock(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_atomic_t *condition)
+{
+ LASSERT(cfs_hash_with_spin_bktlock(hs));
+ return cfs_atomic_dec_and_lock(condition,
+ &bd->bd_bucket->hsb_lock.spin);
+}
+
+static inline cfs_hlist_head_t *cfs_hash_bd_hhead(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd)
+{
+ return hs->hs_hops->hop_hhead(hs, bd);
+}
+
+cfs_hlist_node_t *cfs_hash_bd_lookup_locked(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd, void *key);
+cfs_hlist_node_t *cfs_hash_bd_findadd_locked(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd, void *key,
+ cfs_hlist_node_t *hnode,
+ int insist_add);
+cfs_hlist_node_t *cfs_hash_bd_finddel_locked(cfs_hash_t *hs,
+ cfs_hash_bd_t *bd, void *key,
+ cfs_hlist_node_t *hnode);
+
+/**
+ * operations on cfs_hash bucket (bd: bucket descriptor),
+ * they are safe for hash-table with rehash
+ */
+void cfs_hash_dual_bd_get(cfs_hash_t *hs, void *key, cfs_hash_bd_t *bds);
+void cfs_hash_dual_bd_lock(cfs_hash_t *hs, cfs_hash_bd_t *bds, int excl);
+void cfs_hash_dual_bd_unlock(cfs_hash_t *hs, cfs_hash_bd_t *bds, int excl);
- return cfs_hash_put(hs, hnode);
+static inline void cfs_hash_dual_bd_get_and_lock(cfs_hash_t *hs, void *key,
+ cfs_hash_bd_t *bds, int excl)
+{
+ cfs_hash_dual_bd_get(hs, key, bds);
+ cfs_hash_dual_bd_lock(hs, bds, excl);
}
+cfs_hlist_node_t *cfs_hash_dual_bd_lookup_locked(cfs_hash_t *hs,
+ cfs_hash_bd_t *bds, void *key);
+cfs_hlist_node_t *cfs_hash_dual_bd_findadd_locked(cfs_hash_t *hs,
+ cfs_hash_bd_t *bds, void *key,
+ cfs_hlist_node_t *hnode,
+ int insist_add);
+cfs_hlist_node_t *cfs_hash_dual_bd_finddel_locked(cfs_hash_t *hs,
+ cfs_hash_bd_t *bds, void *key,
+ cfs_hlist_node_t *hnode);
+
/* Hash init/cleanup functions */
-cfs_hash_t *cfs_hash_create(char *name, unsigned int cur_bits,
- unsigned int max_bits,
- cfs_hash_ops_t *ops, int flags);
+cfs_hash_t *cfs_hash_create(char *name, unsigned cur_bits, unsigned max_bits,
+ unsigned bkt_bits, unsigned extra_bytes,
+ unsigned min_theta, unsigned max_theta,
+ cfs_hash_ops_t *ops, unsigned flags);
+
cfs_hash_t *cfs_hash_getref(cfs_hash_t *hs);
void cfs_hash_putref(cfs_hash_t *hs);
void *cfs_hash_del_key(cfs_hash_t *hs, void *key);
/* Hash lookup/for_each functions */
+#define CFS_HASH_LOOP_HOG 1024
+
+typedef int (*cfs_hash_for_each_cb_t)(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *node, void *data);
void *cfs_hash_lookup(cfs_hash_t *hs, void *key);
-typedef void (*cfs_hash_for_each_cb_t)(void *obj, void *data);
void cfs_hash_for_each(cfs_hash_t *hs, cfs_hash_for_each_cb_t, void *data);
void cfs_hash_for_each_safe(cfs_hash_t *hs, cfs_hash_for_each_cb_t, void *data);
-void cfs_hash_for_each_empty(cfs_hash_t *hs, cfs_hash_for_each_cb_t, void *data);
+int cfs_hash_for_each_nolock(cfs_hash_t *hs,
+ cfs_hash_for_each_cb_t, void *data);
+int cfs_hash_for_each_empty(cfs_hash_t *hs,
+ cfs_hash_for_each_cb_t, void *data);
void cfs_hash_for_each_key(cfs_hash_t *hs, void *key,
cfs_hash_for_each_cb_t, void *data);
typedef int (*cfs_hash_cond_opt_cb_t)(void *obj, void *data);
void cfs_hash_cond_del(cfs_hash_t *hs, cfs_hash_cond_opt_cb_t, void *data);
+void cfs_hash_hlist_for_each(cfs_hash_t *hs, unsigned hindex,
+ cfs_hash_for_each_cb_t, void *data);
+int cfs_hash_is_empty(cfs_hash_t *hs);
+__u64 cfs_hash_size_get(cfs_hash_t *hs);
+
/*
* Rehash - Theta is calculated to be the average chained
* hash depth assuming a perfectly uniform hash funcion.
*/
-int cfs_hash_rehash(cfs_hash_t *hs, int bits);
+void cfs_hash_rehash_cancel_locked(cfs_hash_t *hs);
+void cfs_hash_rehash_cancel(cfs_hash_t *hs);
+int cfs_hash_rehash(cfs_hash_t *hs, int do_rehash);
void cfs_hash_rehash_key(cfs_hash_t *hs, void *old_key,
void *new_key, cfs_hlist_node_t *hnode);
+#if CFS_HASH_DEBUG_LEVEL > CFS_HASH_DEBUG_1
+/* Validate hnode references the correct key */
+static inline void
+cfs_hash_key_validate(cfs_hash_t *hs, void *key,
+ cfs_hlist_node_t *hnode)
+{
+ LASSERT(cfs_hash_keycmp(hs, key, hnode));
+}
+
+/* Validate hnode is in the correct bucket */
+static inline void
+cfs_hash_bucket_validate(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ cfs_hash_bd_t bds[2];
+
+ cfs_hash_dual_bd_get(hs, cfs_hash_key(hs, hnode), bds);
+ LASSERT(bds[0].bd_bucket == bd->bd_bucket ||
+ bds[1].bd_bucket == bd->bd_bucket);
+}
+
+#else /* CFS_HASH_DEBUG_LEVEL > CFS_HASH_DEBUG_1 */
+
+static inline void
+cfs_hash_key_validate(cfs_hash_t *hs, void *key,
+ cfs_hlist_node_t *hnode) {}
+
+static inline void
+cfs_hash_bucket_validate(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode) {}
+
+#endif /* CFS_HASH_DEBUG_LEVEL */
#define CFS_HASH_THETA_BITS 10
+#define CFS_HASH_MIN_THETA (1U << (CFS_HASH_THETA_BITS - 1))
+#define CFS_HASH_MAX_THETA (1U << (CFS_HASH_THETA_BITS + 1))
/* Return integer component of theta */
static inline int __cfs_hash_theta_int(int theta)
static inline void __cfs_hash_set_theta(cfs_hash_t *hs, int min, int max)
{
LASSERT(min < max);
- hs->hs_min_theta = min;
- hs->hs_max_theta = max;
+ hs->hs_min_theta = (__u16)min;
+ hs->hs_max_theta = (__u16)max;
}
/* Generic debug formatting routines mainly for proc handler */
return ((unsigned)(key * CFS_GOLDEN_RATIO_PRIME_64) & mask);
}
-#define cfs_hash_for_each_bucket(hs, hsb, pos) \
- for (pos = 0; \
- pos <= hs->hs_cur_mask && \
- (hsb = hs->hs_buckets[pos]); \
- pos++)
+/** iterate over all buckets in @bds (array of cfs_hash_bd_t) */
+#define cfs_hash_for_each_bd(bds, n, i) \
+ for (i = 0; i < n && (bds)[i].bd_bucket != NULL; i++)
+
+/** iterate over all buckets of @hs */
+#define cfs_hash_for_each_bucket(hs, bd, pos) \
+ for (pos = 0; \
+ pos < CFS_HASH_NBKT(hs) && \
+ ((bd)->bd_bucket = (hs)->hs_buckets[pos]) != NULL; pos++)
+
+/** iterate over all hlist of bucket @bd */
+#define cfs_hash_bd_for_each_hlist(hs, bd, hlist) \
+ for ((bd)->bd_offset = 0; \
+ (bd)->bd_offset < CFS_HASH_BKT_NHLIST(hs) && \
+ (hlist = cfs_hash_bd_hhead(hs, bd)) != NULL; \
+ (bd)->bd_offset++)
-#define cfs_hash_for_each_bucket_restart(hs, hsb, pos) \
- for (/* pos=0 done once by caller */; \
- pos <= hs->hs_cur_mask && \
- (hsb = hs->hs_buckets[pos]); \
- pos++)
/* !__LIBCFS__HASH_H__ */
#endif
* - ignore hs_rwlock if without CFS_HASH_REHASH setting
* - buckets are allocated one by one(intead of contiguous memory),
* to avoid unnecessary cacheline conflict
+ *
+ * 2010-03-01: Liang Zhen <zhen.liang@sun.com>
+ * - "bucket" is a group of hlist_head now, user can speicify bucket size
+ * by bkt_bits of cfs_hash_create(), all hlist_heads in a bucket share
+ * one lock for reducing memory overhead.
+ *
+ * - support lockless hash, caller will take care of locks:
+ * avoid lock overhead for hash tables that are already protected
+ * by locking in the caller for another reason
+ *
+ * - support both spin_lock/rwlock for bucket:
+ * overhead of spinlock contention is lower than read/write
+ * contention of rwlock, so using spinlock to serialize operations on
+ * bucket is more reasonable for those frequently changed hash tables
+ *
+ * - support one-single lock mode:
+ * one lock to protect all hash operations to avoid overhead of
+ * multiple locks if hash table is always small
+ *
+ * - removed a lot of unnecessary addref & decref on hash element:
+ * addref & decref are atomic operations in many use-cases which
+ * are expensive.
+ *
+ * - support non-blocking cfs_hash_add() and cfs_hash_findadd():
+ * some lustre use-cases require these functions to be strictly
+ * non-blocking, we need to schedule required rehash on a different
+ * thread on those cases.
+ *
+ * - safer rehash on large hash table
+ * In old implementation, rehash function will exclusively lock the
+ * hash table and finish rehash in one batch, it's dangerous on SMP
+ * system because rehash millions of elements could take long time.
+ * New implemented rehash can release lock and relax CPU in middle
+ * of rehash, it's safe for another thread to search/change on the
+ * hash table even it's in rehasing.
+ *
+ * - support two different refcount modes
+ * . hash table has refcount on element
+ * . hash table doesn't change refcount on adding/removing element
+ *
+ * - support long name hash table (for param-tree)
+ *
+ * - fix a bug for cfs_hash_rehash_key:
+ * in old implementation, cfs_hash_rehash_key could screw up the
+ * hash-table because @key is overwritten without any protection.
+ * Now we need user to define hs_keycpy for those rehash enabled
+ * hash tables, cfs_hash_rehash_key will overwrite hash-key
+ * inside lock by calling hs_keycpy.
+ *
+ * - better hash iteration:
+ * Now we support both locked iteration & lockless iteration of hash
+ * table. Also, user can break the iteration by return 1 in callback.
*/
#include <libcfs/libcfs.h>
-static void cfs_hash_destroy(cfs_hash_t *hs);
+#if CFS_HASH_DEBUG_LEVEL >= CFS_HASH_DEBUG_1
+static unsigned int warn_on_depth = 0;
+CFS_MODULE_PARM(warn_on_depth, "i", uint, 0644,
+ "warning when hash depth is high.");
+#endif
+
+static inline void
+cfs_hash_nl_lock(cfs_hash_lock_t *lock, int exclusive) {}
+
+static inline void
+cfs_hash_nl_unlock(cfs_hash_lock_t *lock, int exclusive) {}
+
+static inline void
+cfs_hash_spin_lock(cfs_hash_lock_t *lock, int exclusive)
+{
+ cfs_spin_lock(&lock->spin);
+}
+
+static inline void
+cfs_hash_spin_unlock(cfs_hash_lock_t *lock, int exclusive)
+{
+ cfs_spin_unlock(&lock->spin);
+}
+
+static inline void
+cfs_hash_rw_lock(cfs_hash_lock_t *lock, int exclusive)
+{
+ if (!exclusive)
+ cfs_read_lock(&lock->rw);
+ else
+ cfs_write_lock(&lock->rw);
+}
+
+static inline void
+cfs_hash_rw_unlock(cfs_hash_lock_t *lock, int exclusive)
+{
+ if (!exclusive)
+ cfs_read_unlock(&lock->rw);
+ else
+ cfs_write_unlock(&lock->rw);
+}
+
+/** No lock hash */
+static cfs_hash_lock_ops_t cfs_hash_nl_lops =
+{
+ .hs_lock = cfs_hash_nl_lock,
+ .hs_unlock = cfs_hash_nl_unlock,
+ .hs_bkt_lock = cfs_hash_nl_lock,
+ .hs_bkt_unlock = cfs_hash_nl_unlock,
+};
+
+/** no bucket lock, one spinlock to protect everything */
+static cfs_hash_lock_ops_t cfs_hash_nbl_lops =
+{
+ .hs_lock = cfs_hash_spin_lock,
+ .hs_unlock = cfs_hash_spin_unlock,
+ .hs_bkt_lock = cfs_hash_nl_lock,
+ .hs_bkt_unlock = cfs_hash_nl_unlock,
+};
+
+/** spin bucket lock, rehash is enabled */
+static cfs_hash_lock_ops_t cfs_hash_bkt_spin_lops =
+{
+ .hs_lock = cfs_hash_rw_lock,
+ .hs_unlock = cfs_hash_rw_unlock,
+ .hs_bkt_lock = cfs_hash_spin_lock,
+ .hs_bkt_unlock = cfs_hash_spin_unlock,
+};
+
+/** rw bucket lock, rehash is enabled */
+static cfs_hash_lock_ops_t cfs_hash_bkt_rw_lops =
+{
+ .hs_lock = cfs_hash_rw_lock,
+ .hs_unlock = cfs_hash_rw_unlock,
+ .hs_bkt_lock = cfs_hash_rw_lock,
+ .hs_bkt_unlock = cfs_hash_rw_unlock,
+};
+
+/** spin bucket lock, rehash is disabled */
+static cfs_hash_lock_ops_t cfs_hash_nr_bkt_spin_lops =
+{
+ .hs_lock = cfs_hash_nl_lock,
+ .hs_unlock = cfs_hash_nl_unlock,
+ .hs_bkt_lock = cfs_hash_spin_lock,
+ .hs_bkt_unlock = cfs_hash_spin_unlock,
+};
+
+/** rw bucket lock, rehash is disabled */
+static cfs_hash_lock_ops_t cfs_hash_nr_bkt_rw_lops =
+{
+ .hs_lock = cfs_hash_nl_lock,
+ .hs_unlock = cfs_hash_nl_unlock,
+ .hs_bkt_lock = cfs_hash_rw_lock,
+ .hs_bkt_unlock = cfs_hash_rw_unlock,
+};
static void
-cfs_hash_rlock(cfs_hash_t *hs)
+cfs_hash_lock_setup(cfs_hash_t *hs)
{
- if ((hs->hs_flags & CFS_HASH_REHASH) != 0)
- cfs_read_lock(&hs->hs_rwlock);
+ if (cfs_hash_with_no_lock(hs)) {
+ hs->hs_lops = &cfs_hash_nl_lops;
+
+ } else if (cfs_hash_with_no_bktlock(hs)) {
+ hs->hs_lops = &cfs_hash_nbl_lops;
+ cfs_spin_lock_init(&hs->hs_lock.spin);
+
+ } else if (cfs_hash_with_rehash(hs)) {
+ cfs_rwlock_init(&hs->hs_lock.rw);
+
+ if (cfs_hash_with_rw_bktlock(hs))
+ hs->hs_lops = &cfs_hash_bkt_rw_lops;
+ else if (cfs_hash_with_spin_bktlock(hs))
+ hs->hs_lops = &cfs_hash_bkt_spin_lops;
+ else
+ LBUG();
+ } else {
+ if (cfs_hash_with_rw_bktlock(hs))
+ hs->hs_lops = &cfs_hash_nr_bkt_rw_lops;
+ else if (cfs_hash_with_spin_bktlock(hs))
+ hs->hs_lops = &cfs_hash_nr_bkt_spin_lops;
+ else
+ LBUG();
+ }
}
+/**
+ * Simple hash head without depth tracking
+ * new element is always added to head of hlist
+ */
+typedef struct {
+ cfs_hlist_head_t hh_head; /**< entries list */
+} cfs_hash_head_t;
+
+static int
+cfs_hash_hh_hhead_size(cfs_hash_t *hs)
+{
+ return sizeof(cfs_hash_head_t);
+}
+
+static cfs_hlist_head_t *
+cfs_hash_hh_hhead(cfs_hash_t *hs, cfs_hash_bd_t *bd)
+{
+ cfs_hash_head_t *head = (cfs_hash_head_t *)&bd->bd_bucket->hsb_head[0];
+
+ return &head[bd->bd_offset].hh_head;
+}
+
+static int
+cfs_hash_hh_hnode_add(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ cfs_hlist_add_head(hnode, cfs_hash_hh_hhead(hs, bd));
+ return -1; /* unknown depth */
+}
+
+static int
+cfs_hash_hh_hnode_del(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ cfs_hlist_del_init(hnode);
+ return -1; /* unknown depth */
+}
+
+/**
+ * Simple hash head with depth tracking
+ * new element is always added to head of hlist
+ */
+typedef struct {
+ cfs_hlist_head_t hd_head; /**< entries list */
+ unsigned int hd_depth; /**< list length */
+} cfs_hash_head_dep_t;
+
+static int
+cfs_hash_hd_hhead_size(cfs_hash_t *hs)
+{
+ return sizeof(cfs_hash_head_dep_t);
+}
+
+static cfs_hlist_head_t *
+cfs_hash_hd_hhead(cfs_hash_t *hs, cfs_hash_bd_t *bd)
+{
+ cfs_hash_head_dep_t *head;
+
+ head = (cfs_hash_head_dep_t *)&bd->bd_bucket->hsb_head[0];
+ return &head[bd->bd_offset].hd_head;
+}
+
+static int
+cfs_hash_hd_hnode_add(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ cfs_hash_head_dep_t *hh = container_of(cfs_hash_hd_hhead(hs, bd),
+ cfs_hash_head_dep_t, hd_head);
+ cfs_hlist_add_head(hnode, &hh->hd_head);
+ return ++hh->hd_depth;
+}
+
+static int
+cfs_hash_hd_hnode_del(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ cfs_hash_head_dep_t *hh = container_of(cfs_hash_hd_hhead(hs, bd),
+ cfs_hash_head_dep_t, hd_head);
+ cfs_hlist_del_init(hnode);
+ return --hh->hd_depth;
+}
+
+/**
+ * double links hash head without depth tracking
+ * new element is always added to tail of hlist
+ */
+typedef struct {
+ cfs_hlist_head_t dh_head; /**< entries list */
+ cfs_hlist_node_t *dh_tail; /**< the last entry */
+} cfs_hash_dhead_t;
+
+static int
+cfs_hash_dh_hhead_size(cfs_hash_t *hs)
+{
+ return sizeof(cfs_hash_dhead_t);
+}
+
+static cfs_hlist_head_t *
+cfs_hash_dh_hhead(cfs_hash_t *hs, cfs_hash_bd_t *bd)
+{
+ cfs_hash_dhead_t *head;
+
+ head = (cfs_hash_dhead_t *)&bd->bd_bucket->hsb_head[0];
+ return &head[bd->bd_offset].dh_head;
+}
+
+static int
+cfs_hash_dh_hnode_add(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ cfs_hash_dhead_t *dh = container_of(cfs_hash_dh_hhead(hs, bd),
+ cfs_hash_dhead_t, dh_head);
+
+ if (dh->dh_tail != NULL) /* not empty */
+ cfs_hlist_add_after(dh->dh_tail, hnode);
+ else /* empty list */
+ cfs_hlist_add_head(hnode, &dh->dh_head);
+ dh->dh_tail = hnode;
+ return -1; /* unknown depth */
+}
+
+static int
+cfs_hash_dh_hnode_del(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnd)
+{
+ cfs_hash_dhead_t *dh = container_of(cfs_hash_dh_hhead(hs, bd),
+ cfs_hash_dhead_t, dh_head);
+
+ if (hnd->next == NULL) { /* it's the tail */
+ dh->dh_tail = (hnd->pprev == &dh->dh_head.first) ? NULL :
+ container_of(hnd->pprev, cfs_hlist_node_t, next);
+ }
+ cfs_hlist_del_init(hnd);
+ return -1; /* unknown depth */
+}
+
+/**
+ * double links hash head with depth tracking
+ * new element is always added to tail of hlist
+ */
+typedef struct {
+ cfs_hlist_head_t dd_head; /**< entries list */
+ cfs_hlist_node_t *dd_tail; /**< the last entry */
+ unsigned int dd_depth; /**< list length */
+} cfs_hash_dhead_dep_t;
+
+static int
+cfs_hash_dd_hhead_size(cfs_hash_t *hs)
+{
+ return sizeof(cfs_hash_dhead_dep_t);
+}
+
+static cfs_hlist_head_t *
+cfs_hash_dd_hhead(cfs_hash_t *hs, cfs_hash_bd_t *bd)
+{
+ cfs_hash_dhead_dep_t *head;
+
+ head = (cfs_hash_dhead_dep_t *)&bd->bd_bucket->hsb_head[0];
+ return &head[bd->bd_offset].dd_head;
+}
+
+static int
+cfs_hash_dd_hnode_add(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ cfs_hash_dhead_dep_t *dh = container_of(cfs_hash_dd_hhead(hs, bd),
+ cfs_hash_dhead_dep_t, dd_head);
+
+ if (dh->dd_tail != NULL) /* not empty */
+ cfs_hlist_add_after(dh->dd_tail, hnode);
+ else /* empty list */
+ cfs_hlist_add_head(hnode, &dh->dd_head);
+ dh->dd_tail = hnode;
+ return ++dh->dd_depth;
+}
+
+static int
+cfs_hash_dd_hnode_del(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnd)
+{
+ cfs_hash_dhead_dep_t *dh = container_of(cfs_hash_dd_hhead(hs, bd),
+ cfs_hash_dhead_dep_t, dd_head);
+
+ if (hnd->next == NULL) { /* it's the tail */
+ dh->dd_tail = (hnd->pprev == &dh->dd_head.first) ? NULL :
+ container_of(hnd->pprev, cfs_hlist_node_t, next);
+ }
+ cfs_hlist_del_init(hnd);
+ return --dh->dd_depth;
+}
+
+static cfs_hash_hlist_ops_t cfs_hash_hh_hops = {
+ .hop_hhead = cfs_hash_hh_hhead,
+ .hop_hhead_size = cfs_hash_hh_hhead_size,
+ .hop_hnode_add = cfs_hash_hh_hnode_add,
+ .hop_hnode_del = cfs_hash_hh_hnode_del,
+};
+
+static cfs_hash_hlist_ops_t cfs_hash_hd_hops = {
+ .hop_hhead = cfs_hash_hd_hhead,
+ .hop_hhead_size = cfs_hash_hd_hhead_size,
+ .hop_hnode_add = cfs_hash_hd_hnode_add,
+ .hop_hnode_del = cfs_hash_hd_hnode_del,
+};
+
+static cfs_hash_hlist_ops_t cfs_hash_dh_hops = {
+ .hop_hhead = cfs_hash_dh_hhead,
+ .hop_hhead_size = cfs_hash_dh_hhead_size,
+ .hop_hnode_add = cfs_hash_dh_hnode_add,
+ .hop_hnode_del = cfs_hash_dh_hnode_del,
+};
+
+static cfs_hash_hlist_ops_t cfs_hash_dd_hops = {
+ .hop_hhead = cfs_hash_dd_hhead,
+ .hop_hhead_size = cfs_hash_dd_hhead_size,
+ .hop_hnode_add = cfs_hash_dd_hnode_add,
+ .hop_hnode_del = cfs_hash_dd_hnode_del,
+};
+
static void
-cfs_hash_runlock(cfs_hash_t *hs)
+cfs_hash_hlist_setup(cfs_hash_t *hs)
{
- if ((hs->hs_flags & CFS_HASH_REHASH) != 0)
- cfs_read_unlock(&hs->hs_rwlock);
+ if (cfs_hash_with_add_tail(hs)) {
+ hs->hs_hops = cfs_hash_with_depth(hs) ?
+ &cfs_hash_dd_hops : &cfs_hash_dh_hops;
+ } else {
+ hs->hs_hops = cfs_hash_with_depth(hs) ?
+ &cfs_hash_hd_hops : &cfs_hash_hh_hops;
+ }
}
static void
-cfs_hash_wlock(cfs_hash_t *hs)
+cfs_hash_bd_from_key(cfs_hash_t *hs, cfs_hash_bucket_t **bkts,
+ unsigned int bits, void *key, cfs_hash_bd_t *bd)
+{
+ unsigned int index = cfs_hash_id(hs, key, (1U << bits) - 1);
+
+ LASSERT(bits == hs->hs_cur_bits || bits == hs->hs_rehash_bits);
+
+ bd->bd_bucket = bkts[index & ((1U << (bits - hs->hs_bkt_bits)) - 1)];
+ bd->bd_offset = index >> (bits - hs->hs_bkt_bits);
+}
+
+void
+cfs_hash_bd_get(cfs_hash_t *hs, void *key, cfs_hash_bd_t *bd)
+{
+ /* NB: caller should hold hs->hs_rwlock if REHASH is set */
+ if (likely(hs->hs_rehash_buckets == NULL)) {
+ cfs_hash_bd_from_key(hs, hs->hs_buckets,
+ hs->hs_cur_bits, key, bd);
+ } else {
+ LASSERT(hs->hs_rehash_bits != 0);
+ cfs_hash_bd_from_key(hs, hs->hs_rehash_buckets,
+ hs->hs_rehash_bits, key, bd);
+ }
+}
+CFS_EXPORT_SYMBOL(cfs_hash_bd_get);
+
+static inline void
+cfs_hash_bd_dep_record(cfs_hash_t *hs, cfs_hash_bd_t *bd, int dep_cur)
+{
+ if (likely(dep_cur <= bd->bd_bucket->hsb_depmax))
+ return;
+
+ bd->bd_bucket->hsb_depmax = dep_cur;
+# if CFS_HASH_DEBUG_LEVEL >= CFS_HASH_DEBUG_1
+ if (likely(warn_on_depth == 0 ||
+ max(warn_on_depth, hs->hs_dep_max) >= dep_cur))
+ return;
+
+ cfs_spin_lock(&hs->hs_dep_lock);
+ hs->hs_dep_max = dep_cur;
+ hs->hs_dep_bkt = bd->bd_bucket->hsb_index;
+ hs->hs_dep_off = bd->bd_offset;
+ hs->hs_dep_bits = hs->hs_cur_bits;
+ cfs_spin_unlock(&hs->hs_dep_lock);
+
+ cfs_wi_schedule(&hs->hs_dep_wi);
+# endif
+}
+
+void
+cfs_hash_bd_add_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
+{
+ int rc;
+
+ rc = hs->hs_hops->hop_hnode_add(hs, bd, hnode);
+ cfs_hash_bd_dep_record(hs, bd, rc);
+ bd->bd_bucket->hsb_version++;
+ if (unlikely(bd->bd_bucket->hsb_version == 0))
+ bd->bd_bucket->hsb_version++;
+ bd->bd_bucket->hsb_count++;
+
+ if (cfs_hash_with_counter(hs))
+ cfs_atomic_inc(&hs->hs_count);
+ if (!cfs_hash_with_no_itemref(hs))
+ cfs_hash_get(hs, hnode);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_bd_add_locked);
+
+void
+cfs_hash_bd_del_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode)
{
- if ((hs->hs_flags & CFS_HASH_REHASH) != 0)
- cfs_write_lock(&hs->hs_rwlock);
+ hs->hs_hops->hop_hnode_del(hs, bd, hnode);
+
+ LASSERT(bd->bd_bucket->hsb_count > 0);
+ bd->bd_bucket->hsb_count--;
+ bd->bd_bucket->hsb_version++;
+ if (unlikely(bd->bd_bucket->hsb_version == 0))
+ bd->bd_bucket->hsb_version++;
+
+ if (cfs_hash_with_counter(hs)) {
+ LASSERT(cfs_atomic_read(&hs->hs_count) > 0);
+ cfs_atomic_dec(&hs->hs_count);
+ }
+ if (!cfs_hash_with_no_itemref(hs))
+ cfs_hash_put_locked(hs, hnode);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_bd_del_locked);
+
+void
+cfs_hash_bd_move_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd_old,
+ cfs_hash_bd_t *bd_new, cfs_hlist_node_t *hnode)
+{
+ cfs_hash_bucket_t *obkt = bd_old->bd_bucket;
+ cfs_hash_bucket_t *nbkt = bd_new->bd_bucket;
+ int rc;
+
+ if (cfs_hash_bd_compare(bd_old, bd_new) == 0)
+ return;
+
+ /* use cfs_hash_bd_hnode_add/del, to avoid atomic & refcount ops
+ * in cfs_hash_bd_del/add_locked */
+ hs->hs_hops->hop_hnode_del(hs, bd_old, hnode);
+ rc = hs->hs_hops->hop_hnode_add(hs, bd_new, hnode);
+ cfs_hash_bd_dep_record(hs, bd_new, rc);
+
+ LASSERT(obkt->hsb_count > 0);
+ obkt->hsb_count--;
+ obkt->hsb_version++;
+ if (unlikely(obkt->hsb_version == 0))
+ obkt->hsb_version++;
+ nbkt->hsb_count++;
+ nbkt->hsb_version++;
+ if (unlikely(nbkt->hsb_version == 0))
+ nbkt->hsb_version++;
}
+CFS_EXPORT_SYMBOL(cfs_hash_bd_move_locked);
+
+enum {
+ /** always set, for sanity (avoid ZERO intent) */
+ CFS_HS_LOOKUP_MASK_FIND = 1 << 0,
+ /** return entry with a ref */
+ CFS_HS_LOOKUP_MASK_REF = 1 << 1,
+ /** add entry if not existing */
+ CFS_HS_LOOKUP_MASK_ADD = 1 << 2,
+ /** delete entry, ignore other masks */
+ CFS_HS_LOOKUP_MASK_DEL = 1 << 3,
+};
+
+typedef enum cfs_hash_lookup_intent {
+ /** return item w/o refcount */
+ CFS_HS_LOOKUP_IT_PEEK = CFS_HS_LOOKUP_MASK_FIND,
+ /** return item with refcount */
+ CFS_HS_LOOKUP_IT_FIND = (CFS_HS_LOOKUP_MASK_FIND |
+ CFS_HS_LOOKUP_MASK_REF),
+ /** return item w/o refcount if existed, otherwise add */
+ CFS_HS_LOOKUP_IT_ADD = (CFS_HS_LOOKUP_MASK_FIND |
+ CFS_HS_LOOKUP_MASK_ADD),
+ /** return item with refcount if existed, otherwise add */
+ CFS_HS_LOOKUP_IT_FINDADD = (CFS_HS_LOOKUP_IT_FIND |
+ CFS_HS_LOOKUP_MASK_ADD),
+ /** delete if existed */
+ CFS_HS_LOOKUP_IT_FINDDEL = (CFS_HS_LOOKUP_MASK_FIND |
+ CFS_HS_LOOKUP_MASK_DEL)
+} cfs_hash_lookup_intent_t;
+
+static cfs_hlist_node_t *
+cfs_hash_bd_lookup_intent(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ void *key, cfs_hlist_node_t *hnode,
+ cfs_hash_lookup_intent_t intent)
+
+{
+ cfs_hlist_head_t *hhead = cfs_hash_bd_hhead(hs, bd);
+ cfs_hlist_node_t *ehnode;
+ cfs_hlist_node_t *match;
+ int intent_add = (intent & CFS_HS_LOOKUP_MASK_ADD) != 0;
+
+ /* with this function, we can avoid a lot of useless refcount ops,
+ * which are expensive atomic operations most time. */
+ match = intent_add ? NULL : hnode;
+ cfs_hlist_for_each(ehnode, hhead) {
+ if (!cfs_hash_keycmp(hs, key, ehnode))
+ continue;
+
+ if (match != NULL && match != ehnode) /* can't match */
+ continue;
+
+ /* match and ... */
+ if ((intent & CFS_HS_LOOKUP_MASK_DEL) != 0) {
+ cfs_hash_bd_del_locked(hs, bd, ehnode);
+ return ehnode;
+ }
+
+ /* caller wants refcount? */
+ if ((intent & CFS_HS_LOOKUP_MASK_REF) != 0)
+ cfs_hash_get(hs, ehnode);
+ return ehnode;
+ }
+ /* no match item */
+ if (!intent_add)
+ return NULL;
+
+ LASSERT(hnode != NULL);
+ cfs_hash_bd_add_locked(hs, bd, hnode);
+ return hnode;
+}
+
+cfs_hlist_node_t *
+cfs_hash_bd_lookup_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd, void *key)
+{
+ return cfs_hash_bd_lookup_intent(hs, bd, key, NULL,
+ CFS_HS_LOOKUP_IT_FIND);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_bd_lookup_locked);
+
+cfs_hlist_node_t *
+cfs_hash_bd_findadd_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ void *key, cfs_hlist_node_t *hnode,
+ int noref)
+{
+ return cfs_hash_bd_lookup_intent(hs, bd, key, hnode,
+ CFS_HS_LOOKUP_IT_ADD |
+ (!noref * CFS_HS_LOOKUP_MASK_REF));
+}
+CFS_EXPORT_SYMBOL(cfs_hash_bd_findadd_locked);
+
+cfs_hlist_node_t *
+cfs_hash_bd_finddel_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ void *key, cfs_hlist_node_t *hnode)
+{
+ /* hnode can be NULL, we find the first item with @key */
+ return cfs_hash_bd_lookup_intent(hs, bd, key, hnode,
+ CFS_HS_LOOKUP_IT_FINDDEL);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_bd_finddel_locked);
+
+static void
+cfs_hash_multi_bd_lock(cfs_hash_t *hs, cfs_hash_bd_t *bds,
+ unsigned n, int excl)
+{
+ cfs_hash_bucket_t *prev = NULL;
+ int i;
+
+ /**
+ * bds must be ascendantly ordered by bd->bd_bucket->hsb_index.
+ * NB: it's possible that several bds point to the same bucket but
+ * have different bd::bd_offset, so need take care of deadlock.
+ */
+ cfs_hash_for_each_bd(bds, n, i) {
+ if (prev == bds[i].bd_bucket)
+ continue;
+
+ LASSERT(prev == NULL ||
+ prev->hsb_index < bds[i].bd_bucket->hsb_index);
+ cfs_hash_bd_lock(hs, &bds[i], excl);
+ prev = bds[i].bd_bucket;
+ }
+}
+
+static void
+cfs_hash_multi_bd_unlock(cfs_hash_t *hs, cfs_hash_bd_t *bds,
+ unsigned n, int excl)
+{
+ cfs_hash_bucket_t *prev = NULL;
+ int i;
+
+ cfs_hash_for_each_bd(bds, n, i) {
+ if (prev != bds[i].bd_bucket) {
+ cfs_hash_bd_unlock(hs, &bds[i], excl);
+ prev = bds[i].bd_bucket;
+ }
+ }
+}
+
+static cfs_hlist_node_t *
+cfs_hash_multi_bd_lookup_locked(cfs_hash_t *hs, cfs_hash_bd_t *bds,
+ unsigned n, void *key)
+{
+ cfs_hlist_node_t *ehnode;
+ unsigned i;
+
+ cfs_hash_for_each_bd(bds, n, i) {
+ ehnode = cfs_hash_bd_lookup_intent(hs, &bds[i], key, NULL,
+ CFS_HS_LOOKUP_IT_FIND);
+ if (ehnode != NULL)
+ return ehnode;
+ }
+ return NULL;
+}
+
+static cfs_hlist_node_t *
+cfs_hash_multi_bd_findadd_locked(cfs_hash_t *hs,
+ cfs_hash_bd_t *bds, unsigned n, void *key,
+ cfs_hlist_node_t *hnode, int noref)
+{
+ cfs_hlist_node_t *ehnode;
+ int intent;
+ unsigned i;
+
+ LASSERT(hnode != NULL);
+ intent = CFS_HS_LOOKUP_IT_PEEK | (!noref * CFS_HS_LOOKUP_MASK_REF);
+
+ cfs_hash_for_each_bd(bds, n, i) {
+ ehnode = cfs_hash_bd_lookup_intent(hs, &bds[i], key,
+ NULL, intent);
+ if (ehnode != NULL)
+ return ehnode;
+ }
+
+ if (i == 1) { /* only one bucket */
+ cfs_hash_bd_add_locked(hs, &bds[0], hnode);
+ } else {
+ cfs_hash_bd_t mybd;
+
+ cfs_hash_bd_get(hs, key, &mybd);
+ cfs_hash_bd_add_locked(hs, &mybd, hnode);
+ }
+
+ return hnode;
+}
+
+static cfs_hlist_node_t *
+cfs_hash_multi_bd_finddel_locked(cfs_hash_t *hs, cfs_hash_bd_t *bds,
+ unsigned n, void *key, cfs_hlist_node_t *hnode)
+{
+ cfs_hlist_node_t *ehnode;
+ unsigned i;
+
+ cfs_hash_for_each_bd(bds, n, i) {
+ ehnode = cfs_hash_bd_lookup_intent(hs, &bds[i], key, hnode,
+ CFS_HS_LOOKUP_IT_FINDDEL);
+ if (ehnode != NULL)
+ return ehnode;
+ }
+ return NULL;
+}
+
+static void
+cfs_hash_bd_order(cfs_hash_bd_t *bd1, cfs_hash_bd_t *bd2)
+{
+ int rc;
+
+ if (bd2->bd_bucket == NULL)
+ return;
+
+ if (bd1->bd_bucket == NULL) {
+ *bd1 = *bd2;
+ bd2->bd_bucket = NULL;
+ return;
+ }
+
+ rc = cfs_hash_bd_compare(bd1, bd2);
+ if (rc == 0) {
+ bd2->bd_bucket = NULL;
+
+ } else if (rc > 0) { /* swab bd1 and bd2 */
+ cfs_hash_bd_t tmp;
+
+ tmp = *bd2;
+ *bd2 = *bd1;
+ *bd1 = tmp;
+ }
+}
+
+void
+cfs_hash_dual_bd_get(cfs_hash_t *hs, void *key, cfs_hash_bd_t *bds)
+{
+ /* NB: caller should hold hs_lock.rw if REHASH is set */
+ cfs_hash_bd_from_key(hs, hs->hs_buckets,
+ hs->hs_cur_bits, key, &bds[0]);
+ if (likely(hs->hs_rehash_buckets == NULL)) {
+ /* no rehash or not rehashing */
+ bds[1].bd_bucket = NULL;
+ return;
+ }
+
+ LASSERT(hs->hs_rehash_bits != 0);
+ cfs_hash_bd_from_key(hs, hs->hs_rehash_buckets,
+ hs->hs_rehash_bits, key, &bds[1]);
+
+ cfs_hash_bd_order(&bds[0], &bds[1]);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_dual_bd_get);
+
+void
+cfs_hash_dual_bd_lock(cfs_hash_t *hs, cfs_hash_bd_t *bds, int excl)
+{
+ cfs_hash_multi_bd_lock(hs, bds, 2, excl);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_dual_bd_lock);
+
+void
+cfs_hash_dual_bd_unlock(cfs_hash_t *hs, cfs_hash_bd_t *bds, int excl)
+{
+ cfs_hash_multi_bd_unlock(hs, bds, 2, excl);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_dual_bd_unlock);
+
+cfs_hlist_node_t *
+cfs_hash_dual_bd_lookup_locked(cfs_hash_t *hs, cfs_hash_bd_t *bds, void *key)
+{
+ return cfs_hash_multi_bd_lookup_locked(hs, bds, 2, key);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_dual_bd_lookup_locked);
+
+cfs_hlist_node_t *
+cfs_hash_dual_bd_findadd_locked(cfs_hash_t *hs, cfs_hash_bd_t *bds,
+ void *key, cfs_hlist_node_t *hnode,
+ int noref)
+{
+ return cfs_hash_multi_bd_findadd_locked(hs, bds, 2, key,
+ hnode, noref);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_dual_bd_findadd_locked);
+
+cfs_hlist_node_t *
+cfs_hash_dual_bd_finddel_locked(cfs_hash_t *hs, cfs_hash_bd_t *bds,
+ void *key, cfs_hlist_node_t *hnode)
+{
+ return cfs_hash_multi_bd_finddel_locked(hs, bds, 2, key, hnode);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_dual_bd_finddel_locked);
static void
-cfs_hash_wunlock(cfs_hash_t *hs)
+cfs_hash_buckets_free(cfs_hash_bucket_t **buckets,
+ int bkt_size, int prev_size, int size)
+{
+ int i;
+
+ for (i = prev_size; i < size; i++) {
+ if (buckets[i] != NULL)
+ LIBCFS_FREE(buckets[i], bkt_size);
+ }
+
+ LIBCFS_FREE(buckets, sizeof(buckets[0]) * size);
+}
+
+/*
+ * Create or grow bucket memory. Return old_buckets if no allocation was
+ * needed, the newly allocated buckets if allocation was needed and
+ * successful, and NULL on error.
+ */
+static cfs_hash_bucket_t **
+cfs_hash_buckets_realloc(cfs_hash_t *hs, cfs_hash_bucket_t **old_bkts,
+ unsigned int old_size, unsigned int new_size)
{
- if ((hs->hs_flags & CFS_HASH_REHASH) != 0)
- cfs_write_unlock(&hs->hs_rwlock);
+ cfs_hash_bucket_t **new_bkts;
+ int i;
+
+ LASSERT(old_size == 0 || old_bkts != NULL);
+
+ if (old_bkts != NULL && old_size == new_size)
+ return old_bkts;
+
+ LIBCFS_ALLOC(new_bkts, sizeof(new_bkts[0]) * new_size);
+ if (new_bkts == NULL)
+ return NULL;
+
+ if (old_bkts != NULL) {
+ memcpy(new_bkts, old_bkts,
+ min(old_size, new_size) * sizeof(*old_bkts));
+ }
+
+ for (i = old_size; i < new_size; i++) {
+ cfs_hlist_head_t *hhead;
+ cfs_hash_bd_t bd;
+
+ LIBCFS_ALLOC(new_bkts[i], cfs_hash_bkt_size(hs));
+ if (new_bkts[i] == NULL) {
+ cfs_hash_buckets_free(new_bkts, cfs_hash_bkt_size(hs),
+ old_size, new_size);
+ return NULL;
+ }
+
+ new_bkts[i]->hsb_index = i;
+ new_bkts[i]->hsb_version = 1; /* shouldn't be zero */
+ new_bkts[i]->hsb_depmax = -1; /* unknown */
+ bd.bd_bucket = new_bkts[i];
+ cfs_hash_bd_for_each_hlist(hs, &bd, hhead)
+ CFS_INIT_HLIST_HEAD(hhead);
+
+ if (cfs_hash_with_no_lock(hs) ||
+ cfs_hash_with_no_bktlock(hs))
+ continue;
+
+ if (cfs_hash_with_rw_bktlock(hs))
+ cfs_rwlock_init(&new_bkts[i]->hsb_lock.rw);
+ else if (cfs_hash_with_spin_bktlock(hs))
+ cfs_spin_lock_init(&new_bkts[i]->hsb_lock.spin);
+ else
+ LBUG(); /* invalid use-case */
+ }
+ return new_bkts;
}
/**
* @flags - CFS_HASH_REHASH enable synamic hash resizing
* - CFS_HASH_SORT enable chained hash sort
*/
+static int cfs_hash_rehash_worker(cfs_workitem_t *wi);
+
+#if CFS_HASH_DEBUG_LEVEL >= CFS_HASH_DEBUG_1
+static int cfs_hash_dep_print(cfs_workitem_t *wi)
+{
+ cfs_hash_t *hs = container_of(wi, cfs_hash_t, hs_dep_wi);
+ int dep;
+ int bkt;
+ int off;
+ int bits;
+
+ cfs_spin_lock(&hs->hs_dep_lock);
+ dep = hs->hs_dep_max;
+ bkt = hs->hs_dep_bkt;
+ off = hs->hs_dep_off;
+ bits = hs->hs_dep_bits;
+ cfs_spin_unlock(&hs->hs_dep_lock);
+
+ LCONSOLE_WARN("#### HASH %s (bits: %d): max depth %d at bucket %d/%d\n",
+ hs->hs_name, bits, dep, bkt, off);
+ cfs_spin_lock(&hs->hs_dep_lock);
+ hs->hs_dep_bits = 0; /* mark as workitem done */
+ cfs_spin_unlock(&hs->hs_dep_lock);
+ return 0;
+}
+
+static void cfs_hash_depth_wi_init(cfs_hash_t *hs)
+{
+ cfs_spin_lock_init(&hs->hs_dep_lock);
+ cfs_wi_init(&hs->hs_dep_wi, hs,
+ cfs_hash_dep_print, CFS_WI_SCHED_ANY);
+}
+
+static void cfs_hash_depth_wi_cancel(cfs_hash_t *hs)
+{
+ if (cfs_wi_cancel(&hs->hs_dep_wi))
+ return;
+
+ cfs_spin_lock(&hs->hs_dep_lock);
+ while (hs->hs_dep_bits != 0) {
+ cfs_spin_unlock(&hs->hs_dep_lock);
+ cfs_cond_resched();
+ cfs_spin_lock(&hs->hs_dep_lock);
+ }
+ cfs_spin_unlock(&hs->hs_dep_lock);
+}
+
+#else /* CFS_HASH_DEBUG_LEVEL < CFS_HASH_DEBUG_1 */
+
+static inline void cfs_hash_depth_wi_init(cfs_hash_t *hs) {}
+static inline void cfs_hash_depth_wi_cancel(cfs_hash_t *hs) {}
+
+#endif /* CFS_HASH_DEBUG_LEVEL >= CFS_HASH_DEBUG_1 */
+
cfs_hash_t *
-cfs_hash_create(char *name, unsigned int cur_bits,
- unsigned int max_bits, cfs_hash_ops_t *ops, int flags)
+cfs_hash_create(char *name, unsigned cur_bits, unsigned max_bits,
+ unsigned bkt_bits, unsigned extra_bytes,
+ unsigned min_theta, unsigned max_theta,
+ cfs_hash_ops_t *ops, unsigned flags)
{
- cfs_hash_t *hs;
- int i;
+ cfs_hash_t *hs;
+ int len;
+
ENTRY;
+ CLASSERT(CFS_HASH_THETA_BITS < 15);
+
LASSERT(name != NULL);
LASSERT(ops != NULL);
- /* The following ops are required for all hash table types */
- LASSERT(ops->hs_hash != NULL);
- LASSERT(ops->hs_key != NULL);
- LASSERT(ops->hs_compare != NULL);
+ LASSERT(ops->hs_key);
+ LASSERT(ops->hs_hash);
+ LASSERT(ops->hs_object);
+ LASSERT(ops->hs_keycmp);
LASSERT(ops->hs_get != NULL);
- LASSERT(ops->hs_put != NULL);
+ LASSERT(ops->hs_put_locked != NULL);
- LASSERT(cur_bits > 0);
- LASSERT(max_bits >= cur_bits);
- LASSERT(max_bits < 31);
- LASSERT(cur_bits == max_bits || (flags & CFS_HASH_REHASH) != 0);
+ if ((flags & CFS_HASH_REHASH) != 0)
+ flags |= CFS_HASH_COUNTER; /* must have counter */
- CFS_ALLOC_PTR(hs);
- if (!hs)
+ LASSERT(cur_bits > 0);
+ LASSERT(cur_bits >= bkt_bits);
+ LASSERT(max_bits >= cur_bits && max_bits < 31);
+ LASSERT(ergo((flags & CFS_HASH_REHASH) == 0, cur_bits == max_bits));
+ LASSERT(ergo((flags & CFS_HASH_REHASH) != 0,
+ (flags & CFS_HASH_NO_LOCK) == 0));
+ LASSERT(ergo((flags & CFS_HASH_REHASH_KEY) != 0,
+ ops->hs_keycpy != NULL));
+
+ len = (flags & CFS_HASH_BIGNAME) == 0 ?
+ CFS_HASH_NAME_LEN : CFS_HASH_BIGNAME_LEN;
+ LIBCFS_ALLOC(hs, offsetof(cfs_hash_t, hs_name[len]));
+ if (hs == NULL)
RETURN(NULL);
- strncpy(hs->hs_name, name, sizeof(hs->hs_name));
- hs->hs_name[sizeof(hs->hs_name) - 1] = '\0';
- cfs_atomic_set(&hs->hs_rehash_count, 0);
+ strncpy(hs->hs_name, name, len);
+ hs->hs_name[len - 1] = '\0';
+ hs->hs_flags = flags;
+
cfs_atomic_set(&hs->hs_refcount, 1);
cfs_atomic_set(&hs->hs_count, 0);
- cfs_rwlock_init(&hs->hs_rwlock);
- hs->hs_cur_bits = cur_bits;
- hs->hs_cur_mask = (1 << cur_bits) - 1;
- hs->hs_min_bits = cur_bits;
- hs->hs_max_bits = max_bits;
- /* XXX: need to fixup cfs_hash_rehash_bits() before this can be
- * anything other than 0.5 and 2.0 */
- hs->hs_min_theta = 1 << (CFS_HASH_THETA_BITS - 1);
- hs->hs_max_theta = 1 << (CFS_HASH_THETA_BITS + 1);
- hs->hs_ops = ops;
- hs->hs_flags = flags;
- /* theta * 1000 */
- __cfs_hash_set_theta(hs, 500, 2000);
+ cfs_hash_lock_setup(hs);
+ cfs_hash_hlist_setup(hs);
- LIBCFS_ALLOC(hs->hs_buckets,
- sizeof(*hs->hs_buckets) << hs->hs_cur_bits);
- if (hs->hs_buckets == NULL) {
- CFS_FREE_PTR(hs);
- RETURN(NULL);
- }
+ hs->hs_cur_bits = (__u8)cur_bits;
+ hs->hs_min_bits = (__u8)cur_bits;
+ hs->hs_max_bits = (__u8)max_bits;
+ hs->hs_bkt_bits = (__u8)bkt_bits;
- for (i = 0; i <= hs->hs_cur_mask; i++) {
- CFS_ALLOC_PTR(hs->hs_buckets[i]);
- if (hs->hs_buckets[i] == NULL) {
- cfs_hash_destroy(hs);
- return NULL;
- }
+ hs->hs_ops = ops;
+ hs->hs_extra_bytes = extra_bytes;
+ hs->hs_rehash_bits = 0;
+ cfs_wi_init(&hs->hs_rehash_wi, hs,
+ cfs_hash_rehash_worker, CFS_WI_SCHED_ANY);
+ cfs_hash_depth_wi_init(hs);
- CFS_INIT_HLIST_HEAD(&hs->hs_buckets[i]->hsb_head);
- cfs_rwlock_init(&hs->hs_buckets[i]->hsb_rwlock);
- cfs_atomic_set(&hs->hs_buckets[i]->hsb_count, 0);
- }
+ if (cfs_hash_with_rehash(hs))
+ __cfs_hash_set_theta(hs, min_theta, max_theta);
+
+ hs->hs_buckets = cfs_hash_buckets_realloc(hs, NULL, 0,
+ CFS_HASH_NBKT(hs));
+ if (hs->hs_buckets != NULL)
+ return hs;
- return hs;
+ LIBCFS_FREE(hs, offsetof(cfs_hash_t, hs_name[len]));
+ RETURN(NULL);
}
CFS_EXPORT_SYMBOL(cfs_hash_create);
static void
cfs_hash_destroy(cfs_hash_t *hs)
{
- cfs_hash_bucket_t *hsb;
cfs_hlist_node_t *hnode;
cfs_hlist_node_t *pos;
+ cfs_hash_bd_t bd;
int i;
ENTRY;
LASSERT(hs != NULL);
+ LASSERT(!cfs_hash_is_exiting(hs) &&
+ !cfs_hash_is_iterating(hs));
- cfs_hash_wlock(hs);
-
- cfs_hash_for_each_bucket(hs, hsb, i) {
- if (hsb == NULL)
- continue;
-
- cfs_write_lock(&hsb->hsb_rwlock);
- cfs_hlist_for_each_safe(hnode, pos, &(hsb->hsb_head)) {
- __cfs_hash_bucket_validate(hs, hsb, hnode);
- __cfs_hash_bucket_del(hs, hsb, hnode);
- cfs_hash_exit(hs, hnode);
+ /**
+ * prohibit further rehashes, don't need any lock because
+ * I'm the only (last) one can change it.
+ */
+ hs->hs_exiting = 1;
+ if (cfs_hash_with_rehash(hs))
+ cfs_hash_rehash_cancel(hs);
+
+ cfs_hash_depth_wi_cancel(hs);
+ /* rehash should be done/canceled */
+ LASSERT(hs->hs_buckets != NULL &&
+ hs->hs_rehash_buckets == NULL);
+
+ cfs_hash_for_each_bucket(hs, &bd, i) {
+ cfs_hlist_head_t *hhead;
+
+ LASSERT(bd.bd_bucket != NULL);
+ /* no need to take this lock, just for consistent code */
+ cfs_hash_bd_lock(hs, &bd, 1);
+
+ cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
+ cfs_hlist_for_each_safe(hnode, pos, hhead) {
+ LASSERTF(!cfs_hash_with_assert_empty(hs),
+ "hash %s bucket %u(%u) is not "
+ " empty: %u items left\n",
+ hs->hs_name, bd.bd_bucket->hsb_index,
+ bd.bd_offset, bd.bd_bucket->hsb_count);
+ /* can't assert key valicate, because we
+ * can interrupt rehash */
+ cfs_hash_bd_del_locked(hs, &bd, hnode);
+ cfs_hash_exit(hs, hnode);
+ }
}
-
- LASSERT(cfs_hlist_empty(&(hsb->hsb_head)));
- LASSERT(cfs_atomic_read(&hsb->hsb_count) == 0);
- cfs_write_unlock(&hsb->hsb_rwlock);
- CFS_FREE_PTR(hsb);
+ LASSERT(bd.bd_bucket->hsb_count == 0);
+ cfs_hash_bd_unlock(hs, &bd, 1);
+ cfs_cond_resched();
}
LASSERT(cfs_atomic_read(&hs->hs_count) == 0);
- cfs_hash_wunlock(hs);
- LIBCFS_FREE(hs->hs_buckets,
- sizeof(*hs->hs_buckets) << hs->hs_cur_bits);
- CFS_FREE_PTR(hs);
+ cfs_hash_buckets_free(hs->hs_buckets, cfs_hash_bkt_size(hs),
+ 0, CFS_HASH_NBKT(hs));
+ i = cfs_hash_with_bigname(hs) ?
+ CFS_HASH_BIGNAME_LEN : CFS_HASH_NAME_LEN;
+ LIBCFS_FREE(hs, offsetof(cfs_hash_t, hs_name[i]));
+
EXIT;
}
}
CFS_EXPORT_SYMBOL(cfs_hash_putref);
-static inline unsigned int
+static inline int
cfs_hash_rehash_bits(cfs_hash_t *hs)
{
- if (!(hs->hs_flags & CFS_HASH_REHASH))
- return 0;
+ if (cfs_hash_with_no_lock(hs) ||
+ !cfs_hash_with_rehash(hs))
+ return -EOPNOTSUPP;
+
+ if (unlikely(cfs_hash_is_exiting(hs)))
+ return -ESRCH;
+
+ if (unlikely(cfs_hash_is_rehashing(hs)))
+ return -EALREADY;
+
+ if (unlikely(cfs_hash_is_iterating(hs)))
+ return -EAGAIN;
/* XXX: need to handle case with max_theta != 2.0
* and the case with min_theta != 0.5 */
(__cfs_hash_theta(hs) > hs->hs_max_theta))
return hs->hs_cur_bits + 1;
+ if (!cfs_hash_with_shrink(hs))
+ return 0;
+
if ((hs->hs_cur_bits > hs->hs_min_bits) &&
(__cfs_hash_theta(hs) < hs->hs_min_theta))
return hs->hs_cur_bits - 1;
}
/**
+ * don't allow inline rehash if:
+ * - user wants non-blocking change (add/del) on hash table
+ * - too many elements
+ */
+static inline int
+cfs_hash_rehash_inline(cfs_hash_t *hs)
+{
+ return !cfs_hash_with_nblk_change(hs) &&
+ cfs_atomic_read(&hs->hs_count) < CFS_HASH_LOOP_HOG;
+}
+
+/**
* Add item @hnode to libcfs hash @hs using @key. The registered
* ops->hs_get function will be called when the item is added.
*/
void
cfs_hash_add(cfs_hash_t *hs, void *key, cfs_hlist_node_t *hnode)
{
- cfs_hash_bucket_t *hsb;
- int bits;
- unsigned i;
- ENTRY;
+ cfs_hash_bd_t bd;
+ int bits;
- __cfs_hash_key_validate(hs, key, hnode);
-
- cfs_hash_rlock(hs);
- i = cfs_hash_id(hs, key, hs->hs_cur_mask);
- hsb = hs->hs_buckets[i];
- LASSERT(i <= hs->hs_cur_mask);
LASSERT(cfs_hlist_unhashed(hnode));
- cfs_write_lock(&hsb->hsb_rwlock);
- __cfs_hash_bucket_add(hs, hsb, hnode);
- cfs_write_unlock(&hsb->hsb_rwlock);
+ cfs_hash_lock(hs, 0);
+ cfs_hash_bd_get_and_lock(hs, key, &bd, 1);
- bits = cfs_hash_rehash_bits(hs);
- cfs_hash_runlock(hs);
- if (bits)
- cfs_hash_rehash(hs, bits);
+ cfs_hash_key_validate(hs, key, hnode);
+ cfs_hash_bd_add_locked(hs, &bd, hnode);
- EXIT;
+ cfs_hash_bd_unlock(hs, &bd, 1);
+
+ bits = cfs_hash_rehash_bits(hs);
+ cfs_hash_unlock(hs, 0);
+ if (bits > 0)
+ cfs_hash_rehash(hs, cfs_hash_rehash_inline(hs));
}
CFS_EXPORT_SYMBOL(cfs_hash_add);
static cfs_hlist_node_t *
-cfs_hash_findadd_unique_hnode(cfs_hash_t *hs, void *key,
- cfs_hlist_node_t *hnode)
+cfs_hash_find_or_add(cfs_hash_t *hs, void *key,
+ cfs_hlist_node_t *hnode, int noref)
{
- int bits = 0;
- cfs_hlist_node_t *ehnode;
- cfs_hash_bucket_t *hsb;
- unsigned i;
- ENTRY;
+ cfs_hlist_node_t *ehnode;
+ cfs_hash_bd_t bds[2];
+ int bits = 0;
- __cfs_hash_key_validate(hs, key, hnode);
-
- cfs_hash_rlock(hs);
- i = cfs_hash_id(hs, key, hs->hs_cur_mask);
- hsb = hs->hs_buckets[i];
- LASSERT(i <= hs->hs_cur_mask);
LASSERT(cfs_hlist_unhashed(hnode));
- cfs_write_lock(&hsb->hsb_rwlock);
- ehnode = __cfs_hash_bucket_lookup(hs, hsb, key);
- if (ehnode) {
- cfs_hash_get(hs, ehnode);
- } else {
- __cfs_hash_bucket_add(hs, hsb, hnode);
- ehnode = hnode;
+ cfs_hash_lock(hs, 0);
+ cfs_hash_dual_bd_get_and_lock(hs, key, bds, 1);
+
+ cfs_hash_key_validate(hs, key, hnode);
+ ehnode = cfs_hash_dual_bd_findadd_locked(hs, bds, key,
+ hnode, noref);
+ cfs_hash_dual_bd_unlock(hs, bds, 1);
+
+ if (ehnode == hnode) /* new item added */
bits = cfs_hash_rehash_bits(hs);
- }
- cfs_write_unlock(&hsb->hsb_rwlock);
- cfs_hash_runlock(hs);
- if (bits)
- cfs_hash_rehash(hs, bits);
+ cfs_hash_unlock(hs, 0);
+ if (bits > 0)
+ cfs_hash_rehash(hs, cfs_hash_rehash_inline(hs));
- RETURN(ehnode);
+ return ehnode;
}
/**
int
cfs_hash_add_unique(cfs_hash_t *hs, void *key, cfs_hlist_node_t *hnode)
{
- cfs_hlist_node_t *ehnode;
- ENTRY;
-
- ehnode = cfs_hash_findadd_unique_hnode(hs, key, hnode);
- if (ehnode != hnode) {
- cfs_hash_put(hs, ehnode);
- RETURN(-EALREADY);
- }
- RETURN(0);
+ RETURN(cfs_hash_find_or_add(hs, key, hnode, 1) != hnode ?
+ -EALREADY : 0);
}
CFS_EXPORT_SYMBOL(cfs_hash_add_unique);
cfs_hash_findadd_unique(cfs_hash_t *hs, void *key,
cfs_hlist_node_t *hnode)
{
- cfs_hlist_node_t *ehnode;
- void *obj;
- ENTRY;
+ hnode = cfs_hash_find_or_add(hs, key, hnode, 0);
- ehnode = cfs_hash_findadd_unique_hnode(hs, key, hnode);
- obj = cfs_hash_get(hs, ehnode);
- cfs_hash_put(hs, ehnode);
- RETURN(obj);
+ return cfs_hash_object(hs, hnode);
}
CFS_EXPORT_SYMBOL(cfs_hash_findadd_unique);
void *
cfs_hash_del(cfs_hash_t *hs, void *key, cfs_hlist_node_t *hnode)
{
- cfs_hash_bucket_t *hsb;
- void *obj;
- unsigned i;
- ENTRY;
-
- __cfs_hash_key_validate(hs, key, hnode);
+ void *obj = NULL;
+ int bits = 0;
+ cfs_hash_bd_t bds[2];
- cfs_hash_rlock(hs);
- i = cfs_hash_id(hs, key, hs->hs_cur_mask);
- hsb = hs->hs_buckets[i];
- LASSERT(i <= hs->hs_cur_mask);
- LASSERT(!cfs_hlist_unhashed(hnode));
-
- cfs_write_lock(&hsb->hsb_rwlock);
- obj = __cfs_hash_bucket_del(hs, hsb, hnode);
- cfs_write_unlock(&hsb->hsb_rwlock);
- cfs_hash_runlock(hs);
-
- RETURN(obj);
-}
-CFS_EXPORT_SYMBOL(cfs_hash_del);
+ cfs_hash_lock(hs, 0);
+ cfs_hash_dual_bd_get_and_lock(hs, key, bds, 1);
-/**
- * Delete item from the libcfs hash @hs when @func return true.
- * The write lock being hold during loop for each bucket to avoid
- * any object be reference.
- */
-void
-cfs_hash_cond_del(cfs_hash_t *hs, cfs_hash_cond_opt_cb_t func, void *data)
-{
- cfs_hlist_node_t *hnode;
- cfs_hlist_node_t *pos;
- cfs_hash_bucket_t *hsb;
- int i;
- ENTRY;
+ if (bds[1].bd_bucket == NULL && hnode != NULL)
+ cfs_hash_bd_del_locked(hs, &bds[0], hnode);
+ else
+ hnode = cfs_hash_dual_bd_finddel_locked(hs, bds, key, hnode);
- cfs_hash_wlock(hs);
- cfs_hash_for_each_bucket(hs, hsb, i) {
- cfs_write_lock(&hsb->hsb_rwlock);
- cfs_hlist_for_each_safe(hnode, pos, &(hsb->hsb_head)) {
- __cfs_hash_bucket_validate(hs, hsb, hnode);
- if (func(cfs_hash_get(hs, hnode), data))
- __cfs_hash_bucket_del(hs, hsb, hnode);
- (void)cfs_hash_put(hs, hnode);
- }
- cfs_write_unlock(&hsb->hsb_rwlock);
+ if (hnode != NULL) {
+ obj = cfs_hash_object(hs, hnode);
+ bits = cfs_hash_rehash_bits(hs);
}
- cfs_hash_wunlock(hs);
- EXIT;
+ cfs_hash_dual_bd_unlock(hs, bds, 1);
+ cfs_hash_unlock(hs, 0);
+ if (bits > 0)
+ cfs_hash_rehash(hs, cfs_hash_rehash_inline(hs));
+
+ return obj;
}
-CFS_EXPORT_SYMBOL(cfs_hash_cond_del);
+CFS_EXPORT_SYMBOL(cfs_hash_del);
/**
* Delete item given @key in libcfs hash @hs. The first @key found in
void *
cfs_hash_del_key(cfs_hash_t *hs, void *key)
{
- void *obj = NULL;
- cfs_hlist_node_t *hnode;
- cfs_hash_bucket_t *hsb;
- unsigned i;
- ENTRY;
-
- cfs_hash_rlock(hs);
- i = cfs_hash_id(hs, key, hs->hs_cur_mask);
- hsb = hs->hs_buckets[i];
- LASSERT(i <= hs->hs_cur_mask);
-
- cfs_write_lock(&hsb->hsb_rwlock);
- hnode = __cfs_hash_bucket_lookup(hs, hsb, key);
- if (hnode)
- obj = __cfs_hash_bucket_del(hs, hsb, hnode);
-
- cfs_write_unlock(&hsb->hsb_rwlock);
- cfs_hash_runlock(hs);
-
- RETURN(obj);
+ return cfs_hash_del(hs, key, NULL);
}
CFS_EXPORT_SYMBOL(cfs_hash_del_key);
{
void *obj = NULL;
cfs_hlist_node_t *hnode;
- cfs_hash_bucket_t *hsb;
- unsigned i;
- ENTRY;
+ cfs_hash_bd_t bds[2];
- cfs_hash_rlock(hs);
- i = cfs_hash_id(hs, key, hs->hs_cur_mask);
- hsb = hs->hs_buckets[i];
- LASSERT(i <= hs->hs_cur_mask);
+ cfs_hash_lock(hs, 0);
+ cfs_hash_dual_bd_get_and_lock(hs, key, bds, 0);
- cfs_read_lock(&hsb->hsb_rwlock);
- hnode = __cfs_hash_bucket_lookup(hs, hsb, key);
- if (hnode)
- obj = cfs_hash_get(hs, hnode);
+ hnode = cfs_hash_dual_bd_lookup_locked(hs, bds, key);
+ if (hnode != NULL)
+ obj = cfs_hash_object(hs, hnode);
- cfs_read_unlock(&hsb->hsb_rwlock);
- cfs_hash_runlock(hs);
+ cfs_hash_dual_bd_unlock(hs, bds, 0);
+ cfs_hash_unlock(hs, 0);
- RETURN(obj);
+ return obj;
}
CFS_EXPORT_SYMBOL(cfs_hash_lookup);
+static void
+cfs_hash_for_each_enter(cfs_hash_t *hs)
+{
+ LASSERT(!cfs_hash_is_exiting(hs));
+
+ if (!cfs_hash_with_rehash(hs))
+ return;
+ /*
+ * NB: it's race on cfs_has_t::hs_iterating, but doesn't matter
+ * because it's just an unreliable signal to rehash-thread,
+ * rehash-thread will try to finsih rehash ASAP when seeing this.
+ */
+ hs->hs_iterating = 1;
+
+ cfs_hash_lock(hs, 1);
+ hs->hs_iterators++;
+
+ /* NB: iteration is mostly called by service thread,
+ * we tend to cancel pending rehash-requst, instead of
+ * blocking service thread, we will relaunch rehash request
+ * after iteration */
+ if (cfs_hash_is_rehashing(hs))
+ cfs_hash_rehash_cancel_locked(hs);
+ cfs_hash_unlock(hs, 1);
+}
+
+static void
+cfs_hash_for_each_exit(cfs_hash_t *hs)
+{
+ int remained;
+ int bits;
+
+ if (!cfs_hash_with_rehash(hs))
+ return;
+ cfs_hash_lock(hs, 1);
+ remained = --hs->hs_iterators;
+ bits = cfs_hash_rehash_bits(hs);
+ cfs_hash_unlock(hs, 1);
+ /* NB: it's race on cfs_has_t::hs_iterating, see above */
+ if (remained == 0)
+ hs->hs_iterating = 0;
+ if (bits > 0) {
+ cfs_hash_rehash(hs, cfs_atomic_read(&hs->hs_count) <
+ CFS_HASH_LOOP_HOG);
+ }
+}
+
/**
* For each item in the libcfs hash @hs call the passed callback @func
* and pass to it as an argument each hash item and the private @data.
- * Before each callback ops->hs_get will be called, and after each
- * callback ops->hs_put will be called. Finally, during the callback
- * the bucket lock is held so the callback must never sleep.
+ *
+ * a) the function may sleep!
+ * b) during the callback:
+ * . the bucket lock is held so the callback must never sleep.
+ * . if @removal_safe is true, use can remove current item by
+ * cfs_hash_bd_del_locked
*/
-void
-cfs_hash_for_each(cfs_hash_t *hs,
- cfs_hash_for_each_cb_t func, void *data)
+static __u64
+cfs_hash_for_each_tight(cfs_hash_t *hs, cfs_hash_for_each_cb_t func,
+ void *data, int remove_safe)
{
cfs_hlist_node_t *hnode;
- cfs_hash_bucket_t *hsb;
- void *obj;
+ cfs_hlist_node_t *pos;
+ cfs_hash_bd_t bd;
+ __u64 count = 0;
+ int excl = !!remove_safe;
+ int loop = 0;
int i;
ENTRY;
- cfs_hash_rlock(hs);
- cfs_hash_for_each_bucket(hs, hsb, i) {
- cfs_read_lock(&hsb->hsb_rwlock);
- cfs_hlist_for_each(hnode, &(hsb->hsb_head)) {
- __cfs_hash_bucket_validate(hs, hsb, hnode);
- obj = cfs_hash_get(hs, hnode);
- func(obj, data);
- (void)cfs_hash_put(hs, hnode);
+ cfs_hash_for_each_enter(hs);
+
+ cfs_hash_lock(hs, 0);
+ LASSERT(!cfs_hash_is_rehashing(hs));
+
+ cfs_hash_for_each_bucket(hs, &bd, i) {
+ cfs_hlist_head_t *hhead;
+
+ cfs_hash_bd_lock(hs, &bd, excl);
+ if (func == NULL) { /* only glimpse size */
+ count += bd.bd_bucket->hsb_count;
+ cfs_hash_bd_unlock(hs, &bd, excl);
+ continue;
+ }
+
+ cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
+ cfs_hlist_for_each_safe(hnode, pos, hhead) {
+ cfs_hash_bucket_validate(hs, &bd, hnode);
+ count++;
+ loop++;
+ if (func(hs, &bd, hnode, data)) {
+ cfs_hash_bd_unlock(hs, &bd, excl);
+ goto out;
+ }
+ }
}
- cfs_read_unlock(&hsb->hsb_rwlock);
+ cfs_hash_bd_unlock(hs, &bd, excl);
+ if (loop < CFS_HASH_LOOP_HOG)
+ continue;
+ loop = 0;
+ cfs_hash_unlock(hs, 0);
+ cfs_cond_resched();
+ cfs_hash_lock(hs, 0);
}
- cfs_hash_runlock(hs);
+ out:
+ cfs_hash_unlock(hs, 0);
- EXIT;
+ cfs_hash_for_each_exit(hs);
+ RETURN(count);
+}
+
+typedef struct {
+ cfs_hash_cond_opt_cb_t func;
+ void *arg;
+} cfs_hash_cond_arg_t;
+
+static int
+cfs_hash_cond_del_locked(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode, void *data)
+{
+ cfs_hash_cond_arg_t *cond = data;
+
+ if (cond->func(cfs_hash_object(hs, hnode), cond->arg))
+ cfs_hash_bd_del_locked(hs, bd, hnode);
+ return 0;
}
-CFS_EXPORT_SYMBOL(cfs_hash_for_each);
/**
- * For each item in the libcfs hash @hs call the passed callback @func
- * and pass to it as an argument each hash item and the private @data.
- * Before each callback ops->hs_get will be called, and after each
- * callback ops->hs_put will be called. During the callback the
- * bucket lock will not be held will allows for the current item
- * to be removed from the hash during the callback. However, care
- * should be taken to prevent other callers from operating on the
- * hash concurrently or list corruption may occur.
+ * Delete item from the libcfs hash @hs when @func return true.
+ * The write lock being hold during loop for each bucket to avoid
+ * any object be reference.
*/
void
+cfs_hash_cond_del(cfs_hash_t *hs, cfs_hash_cond_opt_cb_t func, void *data)
+{
+ cfs_hash_cond_arg_t arg = {
+ .func = func,
+ .arg = data,
+ };
+
+ cfs_hash_for_each_tight(hs, cfs_hash_cond_del_locked, &arg, 1);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_cond_del);
+
+void
+cfs_hash_for_each(cfs_hash_t *hs,
+ cfs_hash_for_each_cb_t func, void *data)
+{
+ cfs_hash_for_each_tight(hs, func, data, 0);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_for_each);
+
+void
cfs_hash_for_each_safe(cfs_hash_t *hs,
cfs_hash_for_each_cb_t func, void *data)
{
- cfs_hlist_node_t *hnode;
- cfs_hlist_node_t *pos;
- cfs_hash_bucket_t *hsb;
- void *obj;
- int i;
+ cfs_hash_for_each_tight(hs, func, data, 1);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_for_each_safe);
+
+static int
+cfs_hash_peek(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+ cfs_hlist_node_t *hnode, void *data)
+{
+ *(int *)data = 0;
+ return 1; /* return 1 to break the loop */
+}
+
+int
+cfs_hash_is_empty(cfs_hash_t *hs)
+{
+ int empty = 1;
+
+ cfs_hash_for_each_tight(hs, cfs_hash_peek, &empty, 0);
+ return empty;
+}
+CFS_EXPORT_SYMBOL(cfs_hash_is_empty);
+
+__u64
+cfs_hash_size_get(cfs_hash_t *hs)
+{
+ return cfs_hash_for_each_tight(hs, NULL, NULL, 0);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_size_get);
+
+/*
+ * cfs_hash_for_each_relax:
+ * Iterate the hash table and call @func on each item without
+ * any lock. This function can't guarantee to finish iteration
+ * if these features are enabled:
+ *
+ * a. if rehash_key is enabled, an item can be moved from
+ * one bucket to another bucket
+ * b. user can remove non-zero-ref item from hash-table,
+ * so the item can be removed from hash-table, even worse,
+ * it's possible that user changed key and insert to another
+ * hash bucket.
+ * there's no way for us to finish iteration correctly on previous
+ * two cases, so iteration has to be stopped on change.
+ */
+static int
+cfs_hash_for_each_relax(cfs_hash_t *hs, cfs_hash_for_each_cb_t func, void *data)
+{
+ cfs_hlist_node_t *hnode;
+ cfs_hlist_node_t *tmp;
+ void *obj;
+ cfs_hash_bd_t bd;
+ __u32 version;
+ int count = 0;
+ int stop_on_change;
+ int rc;
+ int i;
ENTRY;
- cfs_hash_rlock(hs);
- cfs_hash_for_each_bucket(hs, hsb, i) {
- cfs_read_lock(&hsb->hsb_rwlock);
- cfs_hlist_for_each_safe(hnode, pos, &(hsb->hsb_head)) {
- __cfs_hash_bucket_validate(hs, hsb, hnode);
- obj = cfs_hash_get(hs, hnode);
- cfs_read_unlock(&hsb->hsb_rwlock);
- func(obj, data);
- cfs_read_lock(&hsb->hsb_rwlock);
- (void)cfs_hash_put(hs, hnode);
+ stop_on_change = cfs_hash_with_rehash_key(hs) ||
+ !cfs_hash_with_no_itemref(hs) ||
+ CFS_HOP(hs, put_locked) == NULL;
+ cfs_hash_lock(hs, 0);
+ LASSERT(!cfs_hash_is_rehashing(hs));
+
+ cfs_hash_for_each_bucket(hs, &bd, i) {
+ cfs_hlist_head_t *hhead;
+
+ cfs_hash_bd_lock(hs, &bd, 0);
+ version = cfs_hash_bd_version_get(&bd);
+
+ cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
+ for (hnode = hhead->first; hnode != NULL;) {
+ cfs_hash_bucket_validate(hs, &bd, hnode);
+ obj = cfs_hash_get(hs, hnode);
+ cfs_hash_bd_unlock(hs, &bd, 0);
+ cfs_hash_unlock(hs, 0);
+
+ rc = func(hs, &bd, hnode, data);
+ if (stop_on_change)
+ (void)cfs_hash_put(hs, hnode);
+ cfs_cond_resched();
+ count++;
+
+ cfs_hash_lock(hs, 0);
+ cfs_hash_bd_lock(hs, &bd, 0);
+ if (!stop_on_change) {
+ tmp = hnode->next;
+ cfs_hash_put_locked(hs, hnode);
+ hnode = tmp;
+ } else { /* bucket changed? */
+ if (version !=
+ cfs_hash_bd_version_get(&bd))
+ break;
+ /* safe to continue because no change */
+ hnode = hnode->next;
+ }
+ if (rc) /* callback wants to break iteration */
+ break;
+ }
}
- cfs_read_unlock(&hsb->hsb_rwlock);
+ cfs_hash_bd_unlock(hs, &bd, 0);
}
- cfs_hash_runlock(hs);
- EXIT;
+ cfs_hash_unlock(hs, 0);
+
+ return count;
}
-CFS_EXPORT_SYMBOL(cfs_hash_for_each_safe);
+
+int
+cfs_hash_for_each_nolock(cfs_hash_t *hs,
+ cfs_hash_for_each_cb_t func, void *data)
+{
+ ENTRY;
+
+ if (cfs_hash_with_no_lock(hs) ||
+ cfs_hash_with_rehash_key(hs) ||
+ !cfs_hash_with_no_itemref(hs))
+ RETURN(-EOPNOTSUPP);
+
+ if (CFS_HOP(hs, get) == NULL ||
+ (CFS_HOP(hs, put) == NULL &&
+ CFS_HOP(hs, put_locked) == NULL))
+ RETURN(-EOPNOTSUPP);
+
+ cfs_hash_for_each_enter(hs);
+ cfs_hash_for_each_relax(hs, func, data);
+ cfs_hash_for_each_exit(hs);
+
+ RETURN(0);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_for_each_nolock);
/**
* For each hash bucket in the libcfs hash @hs call the passed callback
* items in to the hash. It is the callers responsibility to ensure
* the required locking is in place to prevent concurrent insertions.
*/
-void
+int
cfs_hash_for_each_empty(cfs_hash_t *hs,
cfs_hash_for_each_cb_t func, void *data)
{
- cfs_hlist_node_t *hnode;
- cfs_hash_bucket_t *hsb;
- cfs_hash_bucket_t **hsb_last = NULL;
- void *obj;
- int i = 0;
+ unsigned i = 0;
ENTRY;
-restart:
- cfs_hash_rlock(hs);
- /* If the hash table has changed since we last held lh_rwlock,
- * we need to start traversing the list from the start. */
- if (hs->hs_buckets != hsb_last) {
- i = 0;
- hsb_last = hs->hs_buckets;
- }
- cfs_hash_for_each_bucket_restart(hs, hsb, i) {
- cfs_write_lock(&hsb->hsb_rwlock);
- while (!cfs_hlist_empty(&hsb->hsb_head)) {
- hnode = hsb->hsb_head.first;
- __cfs_hash_bucket_validate(hs, hsb, hnode);
- obj = cfs_hash_get(hs, hnode);
- cfs_write_unlock(&hsb->hsb_rwlock);
- cfs_hash_runlock(hs);
- func(obj, data);
- (void)cfs_hash_put(hs, hnode);
- cfs_cond_resched();
- goto restart;
- }
- cfs_write_unlock(&hsb->hsb_rwlock);
+ if (cfs_hash_with_no_lock(hs))
+ return -EOPNOTSUPP;
+
+ if (CFS_HOP(hs, get) == NULL ||
+ (CFS_HOP(hs, put) == NULL &&
+ CFS_HOP(hs, put_locked) == NULL))
+ return -EOPNOTSUPP;
+
+ cfs_hash_for_each_enter(hs);
+ while (cfs_hash_for_each_relax(hs, func, data)) {
+ CDEBUG(D_INFO, "Try to empty hash: %s, loop: %u\n",
+ hs->hs_name, i++);
}
- cfs_hash_runlock(hs);
- EXIT;
+ cfs_hash_for_each_exit(hs);
+ RETURN(0);
}
CFS_EXPORT_SYMBOL(cfs_hash_for_each_empty);
+void
+cfs_hash_hlist_for_each(cfs_hash_t *hs, unsigned hindex,
+ cfs_hash_for_each_cb_t func, void *data)
+{
+ cfs_hlist_head_t *hhead;
+ cfs_hlist_node_t *hnode;
+ cfs_hash_bd_t bd;
+ ENTRY;
+
+ cfs_hash_for_each_enter(hs);
+ cfs_hash_lock(hs, 0);
+ if (hindex >= CFS_HASH_NHLIST(hs))
+ goto out;
+
+ bd.bd_bucket = hs->hs_buckets[hindex >> hs->hs_bkt_bits];
+ bd.bd_offset = hindex & (CFS_HASH_BKT_NHLIST(hs) - 1);
+
+ cfs_hash_bd_lock(hs, &bd, 0);
+ hhead = cfs_hash_bd_hhead(hs, &bd);
+ cfs_hlist_for_each(hnode, hhead) {
+ if (func(hs, &bd, hnode, data))
+ break;
+ }
+ cfs_hash_bd_unlock(hs, &bd, 0);
+ out:
+ cfs_hash_unlock(hs, 0);
+ cfs_hash_for_each_exit(hs);
+ EXIT;
+}
+
+CFS_EXPORT_SYMBOL(cfs_hash_hlist_for_each);
+
/*
* For each item in the libcfs hash @hs which matches the @key call
* the passed callback @func and pass to it as an argument each hash
- * item and the private @data. Before each callback ops->hs_get will
- * be called, and after each callback ops->hs_put will be called.
- * Finally, during the callback the bucket lock is held so the
- * callback must never sleep.
+ * item and the private @data. During the callback the bucket lock
+ * is held so the callback must never sleep.
*/
void
cfs_hash_for_each_key(cfs_hash_t *hs, void *key,
cfs_hash_for_each_cb_t func, void *data)
{
- cfs_hlist_node_t *hnode;
- cfs_hash_bucket_t *hsb;
- unsigned i;
+ cfs_hlist_node_t *hnode;
+ cfs_hash_bd_t bds[2];
+ unsigned i;
ENTRY;
- cfs_hash_rlock(hs);
- i = cfs_hash_id(hs, key, hs->hs_cur_mask);
- hsb = hs->hs_buckets[i];
- LASSERT(i <= hs->hs_cur_mask);
+ cfs_hash_lock(hs, 0);
- cfs_read_lock(&hsb->hsb_rwlock);
- cfs_hlist_for_each(hnode, &(hsb->hsb_head)) {
- __cfs_hash_bucket_validate(hs, hsb, hnode);
+ cfs_hash_dual_bd_get_and_lock(hs, key, bds, 0);
- if (!cfs_hash_compare(hs, key, hnode))
- continue;
+ cfs_hash_for_each_bd(bds, 2, i) {
+ cfs_hlist_head_t *hlist = cfs_hash_bd_hhead(hs, &bds[i]);
- func(cfs_hash_get(hs, hnode), data);
- (void)cfs_hash_put(hs, hnode);
+ cfs_hlist_for_each(hnode, hlist) {
+ cfs_hash_bucket_validate(hs, &bds[i], hnode);
+
+ if (cfs_hash_keycmp(hs, key, hnode)) {
+ if (func(hs, &bds[i], hnode, data))
+ break;
+ }
+ }
}
- cfs_read_unlock(&hsb->hsb_rwlock);
- cfs_hash_runlock(hs);
+ cfs_hash_dual_bd_unlock(hs, bds, 0);
+ cfs_hash_unlock(hs, 0);
EXIT;
}
* this approach assumes a reasonably uniform hashing function. The
* theta thresholds for @hs are tunable via cfs_hash_set_theta().
*/
-int
-cfs_hash_rehash(cfs_hash_t *hs, int bits)
-{
- cfs_hlist_node_t *hnode;
- cfs_hlist_node_t *pos;
- cfs_hash_bucket_t **old_buckets;
- cfs_hash_bucket_t **rehash_buckets;
- cfs_hash_bucket_t *hs_hsb;
- cfs_hash_bucket_t *rehash_hsb;
- int i;
- int theta;
- int old_mask;
- int old_bits;
- int new_mask = (1 << bits) - 1;
- int rc = 0;
- void *key;
- ENTRY;
+void
+cfs_hash_rehash_cancel_locked(cfs_hash_t *hs)
+{
+ int i;
- LASSERT(!cfs_in_interrupt());
- LASSERT(new_mask > 0);
- LASSERT((hs->hs_flags & CFS_HASH_REHASH) != 0);
+ /* need hold cfs_hash_lock(hs, 1) */
+ LASSERT(cfs_hash_with_rehash(hs) &&
+ !cfs_hash_with_no_lock(hs));
- LIBCFS_ALLOC(rehash_buckets, sizeof(*rehash_buckets) << bits);
- if (!rehash_buckets)
- RETURN(-ENOMEM);
+ if (!cfs_hash_is_rehashing(hs))
+ return;
- for (i = 0; i <= new_mask; i++) {
- CFS_ALLOC_PTR(rehash_buckets[i]);
- if (rehash_buckets[i] == NULL)
- GOTO(free, rc = -ENOMEM);
+ if (cfs_wi_cancel(&hs->hs_rehash_wi)) {
+ hs->hs_rehash_bits = 0;
+ return;
+ }
- CFS_INIT_HLIST_HEAD(&rehash_buckets[i]->hsb_head);
- cfs_rwlock_init(&rehash_buckets[i]->hsb_rwlock);
- cfs_atomic_set(&rehash_buckets[i]->hsb_count, 0);
+ for (i = 2; cfs_hash_is_rehashing(hs); i++) {
+ cfs_hash_unlock(hs, 1);
+ /* raise console warning while waiting too long */
+ CDEBUG(IS_PO2(i >> 3) ? D_WARNING : D_INFO,
+ "hash %s is still rehashing, rescheded %d\n",
+ hs->hs_name, i - 1);
+ cfs_cond_resched();
+ cfs_hash_lock(hs, 1);
}
+}
+CFS_EXPORT_SYMBOL(cfs_hash_rehash_cancel_locked);
- cfs_hash_wlock(hs);
+void
+cfs_hash_rehash_cancel(cfs_hash_t *hs)
+{
+ cfs_hash_lock(hs, 1);
+ cfs_hash_rehash_cancel_locked(hs);
+ cfs_hash_unlock(hs, 1);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_rehash_cancel);
- /*
- * Early return for multiple concurrent racing callers,
- * ensure we only trigger the rehash if it is still needed.
- */
- theta = __cfs_hash_theta(hs);
- if ((theta >= hs->hs_min_theta) && (theta <= hs->hs_max_theta)) {
- cfs_hash_wunlock(hs);
- GOTO(free, rc = -EALREADY);
+int
+cfs_hash_rehash(cfs_hash_t *hs, int do_rehash)
+{
+ int rc;
+ ENTRY;
+
+ LASSERT(cfs_hash_with_rehash(hs) && !cfs_hash_with_no_lock(hs));
+
+ cfs_hash_lock(hs, 1);
+
+ rc = cfs_hash_rehash_bits(hs);
+ if (rc <= 0) {
+ cfs_hash_unlock(hs, 1);
+ return rc;
}
- old_bits = hs->hs_cur_bits;
- old_buckets = hs->hs_buckets;
- old_mask = (1 << old_bits) - 1;
+ hs->hs_rehash_bits = rc;
+ if (!do_rehash) {
+ /* launch and return */
+ cfs_wi_schedule(&hs->hs_rehash_wi);
+ cfs_hash_unlock(hs, 1);
+ return 0;
+ }
- hs->hs_cur_bits = bits;
- hs->hs_cur_mask = (1 << bits) - 1;
- hs->hs_buckets = rehash_buckets;
- cfs_atomic_inc(&hs->hs_rehash_count);
+ /* rehash right now */
+ cfs_hash_unlock(hs, 1);
- for (i = 0; i <= old_mask; i++) {
- hs_hsb = old_buckets[i];
+ return cfs_hash_rehash_worker(&hs->hs_rehash_wi);
+}
+CFS_EXPORT_SYMBOL(cfs_hash_rehash);
- cfs_write_lock(&hs_hsb->hsb_rwlock);
- cfs_hlist_for_each_safe(hnode, pos, &(hs_hsb->hsb_head)) {
+static int
+cfs_hash_rehash_bd(cfs_hash_t *hs, cfs_hash_bd_t *old)
+{
+ cfs_hash_bd_t new;
+ cfs_hlist_head_t *hhead;
+ cfs_hlist_node_t *hnode;
+ cfs_hlist_node_t *pos;
+ void *key;
+ int c = 0;
+
+ /* hold cfs_hash_lock(hs, 1), so don't need any bucket lock */
+ cfs_hash_bd_for_each_hlist(hs, old, hhead) {
+ cfs_hlist_for_each_safe(hnode, pos, hhead) {
key = cfs_hash_key(hs, hnode);
- LASSERT(key);
-
+ LASSERT(key != NULL);
+ /* Validate hnode is in the correct bucket. */
+ cfs_hash_bucket_validate(hs, old, hnode);
/*
- * Validate hnode is in the correct bucket.
+ * Delete from old hash bucket; move to new bucket.
+ * ops->hs_key must be defined.
*/
- if (unlikely(hs->hs_flags & CFS_HASH_DEBUG))
- LASSERT(cfs_hash_id(hs, key, old_mask) == i);
+ cfs_hash_bd_from_key(hs, hs->hs_rehash_buckets,
+ hs->hs_rehash_bits, key, &new);
+ cfs_hash_bd_move_locked(hs, old, &new, hnode);
+ c++;
+ }
+ }
- /*
- * Delete from old hash bucket.
- */
- cfs_hlist_del(hnode);
- LASSERT(cfs_atomic_read(&hs_hsb->hsb_count) > 0);
- cfs_atomic_dec(&hs_hsb->hsb_count);
+ return c;
+}
- /*
- * Add to rehash bucket, ops->hs_key must be defined.
- */
- rehash_hsb = rehash_buckets[cfs_hash_id(hs, key,
- new_mask)];
- cfs_hlist_add_head(hnode, &(rehash_hsb->hsb_head));
- cfs_atomic_inc(&rehash_hsb->hsb_count);
+static int
+cfs_hash_rehash_worker(cfs_workitem_t *wi)
+{
+ cfs_hash_t *hs = container_of(wi, cfs_hash_t, hs_rehash_wi);
+ cfs_hash_bucket_t **bkts;
+ cfs_hash_bd_t bd;
+ unsigned int old_size;
+ unsigned int new_size;
+ int bsize;
+ int count = 0;
+ int rc = 0;
+ int i;
+ ENTRY;
+
+ LASSERT (hs != NULL && cfs_hash_with_rehash(hs));
+
+ cfs_hash_lock(hs, 0);
+ LASSERT(cfs_hash_is_rehashing(hs));
+
+ old_size = CFS_HASH_NBKT(hs);
+ new_size = CFS_HASH_RH_NBKT(hs);
+
+ cfs_hash_unlock(hs, 0);
+
+ /*
+ * don't need hs::hs_rwlock for hs::hs_buckets,
+ * because nobody can change bkt-table except me.
+ */
+ bkts = cfs_hash_buckets_realloc(hs, hs->hs_buckets,
+ old_size, new_size);
+ cfs_hash_lock(hs, 1);
+ if (bkts == NULL) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ if (bkts == hs->hs_buckets) {
+ bkts = NULL; /* do nothing */
+ goto out;
+ }
+
+ rc = __cfs_hash_theta(hs);
+ if ((rc >= hs->hs_min_theta) && (rc <= hs->hs_max_theta)) {
+ /* free the new allocated bkt-table */
+ old_size = new_size;
+ new_size = CFS_HASH_NBKT(hs);
+ rc = -EALREADY;
+ goto out;
+ }
+
+ LASSERT(hs->hs_rehash_buckets == NULL);
+ hs->hs_rehash_buckets = bkts;
+
+ rc = 0;
+ cfs_hash_for_each_bucket(hs, &bd, i) {
+ if (cfs_hash_is_exiting(hs)) {
+ rc = -ESRCH;
+ /* someone wants to destroy the hash, abort now */
+ if (old_size < new_size) /* OK to free old bkt-table */
+ break;
+ /* it's shrinking, need free new bkt-table */
+ hs->hs_rehash_buckets = NULL;
+ old_size = new_size;
+ new_size = CFS_HASH_NBKT(hs);
+ goto out;
+ }
+
+ count += cfs_hash_rehash_bd(hs, &bd);
+ if (count < CFS_HASH_LOOP_HOG ||
+ cfs_hash_is_iterating(hs)) { /* need to finish ASAP */
+ continue;
}
- LASSERT(cfs_hlist_empty(&(hs_hsb->hsb_head)));
- LASSERT(cfs_atomic_read(&hs_hsb->hsb_count) == 0);
- cfs_write_unlock(&hs_hsb->hsb_rwlock);
+ count = 0;
+ cfs_hash_unlock(hs, 1);
+ cfs_cond_resched();
+ cfs_hash_lock(hs, 1);
}
- cfs_hash_wunlock(hs);
- rehash_buckets = old_buckets;
- i = (1 << old_bits);
- bits = old_bits;
- free:
- while (--i >= 0)
- CFS_FREE_PTR(rehash_buckets[i]);
- LIBCFS_FREE(rehash_buckets, sizeof(*rehash_buckets) << bits);
- RETURN(rc);
+ hs->hs_rehash_count++;
+
+ bkts = hs->hs_buckets;
+ hs->hs_buckets = hs->hs_rehash_buckets;
+ hs->hs_rehash_buckets = NULL;
+
+ hs->hs_cur_bits = hs->hs_rehash_bits;
+ out:
+ hs->hs_rehash_bits = 0;
+ if (rc == -ESRCH)
+ cfs_wi_exit(wi); /* never be scheduled again */
+ bsize = cfs_hash_bkt_size(hs);
+ cfs_hash_unlock(hs, 1);
+ /* can't refer to @hs anymore because it could be destroyed */
+ if (bkts != NULL)
+ cfs_hash_buckets_free(bkts, bsize, new_size, old_size);
+ if (rc != 0)
+ CDEBUG(D_INFO, "early quit of of rehashing: %d\n", rc);
+ /* cfs_workitem require us to always return 0 */
+ RETURN(0);
}
-CFS_EXPORT_SYMBOL(cfs_hash_rehash);
/**
* Rehash the object referenced by @hnode in the libcfs hash @hs. The
* the registered cfs_hash_get() and cfs_hash_put() functions will
* not be called.
*/
-void cfs_hash_rehash_key(cfs_hash_t *hs, void *old_key, void *new_key,
- cfs_hlist_node_t *hnode)
+void cfs_hash_rehash_key(cfs_hash_t *hs, void *old_key,
+ void *new_key, cfs_hlist_node_t *hnode)
{
- cfs_hash_bucket_t *old_hsb;
- cfs_hash_bucket_t *new_hsb;
- unsigned i;
- unsigned j;
- ENTRY;
+ cfs_hash_bd_t bds[3];
+ cfs_hash_bd_t old_bds[2];
+ cfs_hash_bd_t new_bd;
- __cfs_hash_key_validate(hs, new_key, hnode);
LASSERT(!cfs_hlist_unhashed(hnode));
- cfs_hash_rlock(hs);
-
- i = cfs_hash_id(hs, old_key, hs->hs_cur_mask);
- old_hsb = hs->hs_buckets[i];
- LASSERT(i <= hs->hs_cur_mask);
-
- j = cfs_hash_id(hs, new_key, hs->hs_cur_mask);
- new_hsb = hs->hs_buckets[j];
- LASSERT(j <= hs->hs_cur_mask);
-
- if (i < j) { /* write_lock ordering */
- cfs_write_lock(&old_hsb->hsb_rwlock);
- cfs_write_lock(&new_hsb->hsb_rwlock);
- } else if (i > j) {
- cfs_write_lock(&new_hsb->hsb_rwlock);
- cfs_write_lock(&old_hsb->hsb_rwlock);
- } else { /* do nothing */
- cfs_hash_runlock(hs);
- EXIT;
- return;
- }
+ cfs_hash_lock(hs, 0);
- /*
- * Migrate item between hash buckets without calling
- * the cfs_hash_get() and cfs_hash_put() callback functions.
- */
- cfs_hlist_del(hnode);
- LASSERT(cfs_atomic_read(&old_hsb->hsb_count) > 0);
- cfs_atomic_dec(&old_hsb->hsb_count);
- cfs_hlist_add_head(hnode, &(new_hsb->hsb_head));
- cfs_atomic_inc(&new_hsb->hsb_count);
+ cfs_hash_dual_bd_get(hs, old_key, old_bds);
+ cfs_hash_bd_get(hs, new_key, &new_bd);
- cfs_write_unlock(&new_hsb->hsb_rwlock);
- cfs_write_unlock(&old_hsb->hsb_rwlock);
- cfs_hash_runlock(hs);
+ bds[0] = old_bds[0];
+ bds[1] = old_bds[1];
+ bds[2] = new_bd;
- EXIT;
+ /* NB: bds[0] and bds[1] are ordered already */
+ cfs_hash_bd_order(&bds[1], &bds[2]);
+ cfs_hash_bd_order(&bds[0], &bds[1]);
+
+ cfs_hash_multi_bd_lock(hs, bds, 3, 1);
+ if (likely(old_bds[1].bd_bucket == NULL)) {
+ cfs_hash_bd_move_locked(hs, &old_bds[0], &new_bd, hnode);
+ } else {
+ cfs_hash_dual_bd_finddel_locked(hs, old_bds, old_key, hnode);
+ cfs_hash_bd_add_locked(hs, &new_bd, hnode);
+ }
+ /* overwrite key inside locks, otherwise may screw up with
+ * other operations, i.e: rehash */
+ cfs_hash_keycpy(hs, new_key, hnode);
+
+ cfs_hash_multi_bd_unlock(hs, bds, 3, 1);
+ cfs_hash_unlock(hs, 0);
}
CFS_EXPORT_SYMBOL(cfs_hash_rehash_key);
int cfs_hash_debug_header(char *str, int size)
{
- return snprintf(str, size,
- "%-*s%6s%6s%6s%6s%6s%6s%6s%7s%6s%s\n", CFS_MAX_HASH_NAME,
+ return snprintf(str, size, "%-*s%6s%6s%6s%6s%6s%6s%6s%7s%8s%8s%8s%s\n",
+ CFS_HASH_BIGNAME_LEN,
"name", "cur", "min", "max", "theta", "t-min", "t-max",
- "flags", "rehash", "count", " distribution");
+ "flags", "rehash", "count", "maxdep", "maxdepb",
+ " distribution");
}
CFS_EXPORT_SYMBOL(cfs_hash_debug_header);
+static cfs_hash_bucket_t **
+cfs_hash_full_bkts(cfs_hash_t *hs)
+{
+ /* NB: caller should hold hs->hs_rwlock if REHASH is set */
+ if (hs->hs_rehash_buckets == NULL)
+ return hs->hs_buckets;
+
+ LASSERT(hs->hs_rehash_bits != 0);
+ return hs->hs_rehash_bits > hs->hs_cur_bits ?
+ hs->hs_rehash_buckets : hs->hs_buckets;
+}
+
+static unsigned int
+cfs_hash_full_nbkt(cfs_hash_t *hs)
+{
+ /* NB: caller should hold hs->hs_rwlock if REHASH is set */
+ if (hs->hs_rehash_buckets == NULL)
+ return CFS_HASH_NBKT(hs);
+
+ LASSERT(hs->hs_rehash_bits != 0);
+ return hs->hs_rehash_bits > hs->hs_cur_bits ?
+ CFS_HASH_RH_NBKT(hs) : CFS_HASH_NBKT(hs);
+}
+
int cfs_hash_debug_str(cfs_hash_t *hs, char *str, int size)
{
- cfs_hash_bucket_t *hsb;
+ int dist[8] = { 0, };
+ int maxdep = -1;
+ int maxdepb = -1;
+ int total = 0;
+ int c = 0;
int theta;
int i;
- int c = 0;
- int dist[8] = { 0, };
if (str == NULL || size == 0)
return 0;
- cfs_hash_rlock(hs);
+ cfs_hash_lock(hs, 0);
theta = __cfs_hash_theta(hs);
c += snprintf(str + c, size - c, "%-*s ",
- CFS_MAX_HASH_NAME, hs->hs_name);
+ CFS_HASH_BIGNAME_LEN, hs->hs_name);
c += snprintf(str + c, size - c, "%5d ", 1 << hs->hs_cur_bits);
c += snprintf(str + c, size - c, "%5d ", 1 << hs->hs_min_bits);
c += snprintf(str + c, size - c, "%5d ", 1 << hs->hs_max_bits);
__cfs_hash_theta_int(hs->hs_max_theta),
__cfs_hash_theta_frac(hs->hs_max_theta));
c += snprintf(str + c, size - c, " 0x%02x ", hs->hs_flags);
- c += snprintf(str + c, size - c, "%6d ",
- cfs_atomic_read(&hs->hs_rehash_count));
- c += snprintf(str + c, size - c, "%5d ",
- cfs_atomic_read(&hs->hs_count));
+ c += snprintf(str + c, size - c, "%6d ", hs->hs_rehash_count);
/*
* The distribution is a summary of the chained hash depth in
* Uniform hash distribution: 128/128/0/0/0/0/0/0
* Non-Uniform hash distribution: 128/125/0/0/0/0/2/1
*/
- cfs_hash_for_each_bucket(hs, hsb, i)
- dist[min(__cfs_fls(cfs_atomic_read(&hsb->hsb_count)/max(theta,1)),7)]++;
+ for (i = 0; i < cfs_hash_full_nbkt(hs); i++) {
+ cfs_hash_bd_t bd;
+
+ bd.bd_bucket = cfs_hash_full_bkts(hs)[i];
+ cfs_hash_bd_lock(hs, &bd, 0);
+ if (maxdep < bd.bd_bucket->hsb_depmax) {
+ maxdep = bd.bd_bucket->hsb_depmax;
+#ifdef __KERNEL__
+ maxdepb = cfs_ffz(~maxdep);
+#endif
+ }
+ total += bd.bd_bucket->hsb_count;
+ dist[min(__cfs_fls(bd.bd_bucket->hsb_count/max(theta,1)),7)]++;
+ cfs_hash_bd_unlock(hs, &bd, 0);
+ }
+ c += snprintf(str + c, size - c, "%7d ", total);
+ c += snprintf(str + c, size - c, "%7d ", maxdep);
+ c += snprintf(str + c, size - c, "%7d ", maxdepb);
for (i = 0; i < 8; i++)
c += snprintf(str + c, size - c, "%d%c", dist[i],
(i == 7) ? '\n' : '/');
- cfs_hash_runlock(hs);
+ cfs_hash_unlock(hs, 0);
return c;
}
git://git.whamcloud.com / fs / lustre-release.git / commitdiff