fs/nfs/nfs_subr.c

79  * The hash queues for the access to active and cached rnodes
81  * for each hash bucket is used to control access and to synchronize
82  * lookups, additions, and deletions from the hash queue.
89  * a hash queue and the exclusive lock to the hash queue be held.
90  * If an rnode is not hashed into a hash queue, then it is destroyed
92  * about the file.  The exclusive lock to the hash queue must be
93  * held in order to prevent a lookup in the hash queue from finding
95  * freelist.  The lookup in the hash queue will have the hash queue
103  * rnode is looked up in the hash queues, then either the rnode
108  * The hash queue lock might be held shared and it is possible that
115  * to the hash queue and the thread doing the lookup in the hash
116  * queue is holding either a shared or exclusive lock to the hash
121  *	hash bucket lock -> vnode lock
122  *	hash bucket lock -> freelist lock
154 static long nacache;	/* used strictly to size the number of hash queues */
2266  * into the hash queues.  If the rnode for this fhandle
2269  * Note: make_rnode() may upgrade the hash bucket lock to exclusive.
2328  * into the hash queues.  If the rnode for this fhandle
2331  * Note: make_rnode() may upgrade the hash bucket lock to exclusive.
2418  * This is a hash function in which seemingly obvious and harmless
2422  * rtablehash() implements Jenkins' one-at-a-time hash algorithm.  The
2425  *   http://burtleburtle.net/bob/hash/doobs.html
2430  * the hash algorithm still provides even distribution in all cases and with
2436 	ulong_t hash, len, i;
2441 	for (hash = 0, i = 0; i < len; i++) {
2442 		hash += key[i];
2443 		hash += (hash << 10);
2444 		hash ^= (hash >> 6);
2446 	hash += (hash << 3);
2447 	hash ^= (hash >> 11);
2448 	hash += (hash << 15);
2449 	return (hash & rtablemask);
2684 	 * accessible by it does not reside in the hash queues,
2712 		 * rnode is not in the rnode hash queues, so the
2740 	 * Lock the hash queue and then recheck the reference count
2812  * Put a rnode in the hash table.
2814  * The caller must be holding the exclusive hash queue lock.
2834  * Remove a rnode from the hash table.
2836  * The caller must be holding the hash queue lock.
2854  * Remove a rnode from the hash table.
2856  * The caller must not be holding the hash queue lock.
2870  * The caller must be holding the hash queue lock, either shared or exclusive.
2949  * Destroy inactive vnodes from the hash queues which belong to this
2969 			/* save the hash pointer before destroying */
3064 	 * Walk the hash queues looking for rnodes with page
3196 	 * holding the hash bucket locked.
3267 	 * rnode.  Remove each of these entries from the hash
3447 	 * Allocate and initialize the rnode hash queues
3535 	 * Deallocate the rnode hash queues
4571 		 * hash queues for the rnode.