-
-/*
- * Device ID cache. Currently supports one layout type per struct nfs_client.
- * Add layout type to the lookup key to expand to support multiple types.
- */
-int
-pnfs_alloc_init_deviceid_cache(struct nfs_client *clp,
- void (*free_callback)(struct pnfs_deviceid_node *))
-{
- struct pnfs_deviceid_cache *c;
-
- c = kzalloc(sizeof(struct pnfs_deviceid_cache), GFP_KERNEL);
- if (!c)
- return -ENOMEM;
- spin_lock(&clp->cl_lock);
- if (clp->cl_devid_cache != NULL) {
- atomic_inc(&clp->cl_devid_cache->dc_ref);
- dprintk("%s [kref [%d]]\n", __func__,
- atomic_read(&clp->cl_devid_cache->dc_ref));
- kfree(c);
- } else {
- /* kzalloc initializes hlists */
- spin_lock_init(&c->dc_lock);
- atomic_set(&c->dc_ref, 1);
- c->dc_free_callback = free_callback;
- clp->cl_devid_cache = c;
- dprintk("%s [new]\n", __func__);
- }
- spin_unlock(&clp->cl_lock);
- return 0;
-}
-EXPORT_SYMBOL_GPL(pnfs_alloc_init_deviceid_cache);
-
-/*
- * Called from pnfs_layoutdriver_type->free_lseg
- * last layout segment reference frees deviceid
- */
-void
-pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
- struct pnfs_deviceid_node *devid)
-{
- struct nfs4_deviceid *id = &devid->de_id;
- struct pnfs_deviceid_node *d;
- struct hlist_node *n;
- long h = nfs4_deviceid_hash(id);
-
- dprintk("%s [%d]\n", __func__, atomic_read(&devid->de_ref));
- if (!atomic_dec_and_lock(&devid->de_ref, &c->dc_lock))
- return;
-
- hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[h], de_node)
- if (!memcmp(&d->de_id, id, sizeof(*id))) {
- hlist_del_rcu(&d->de_node);
- spin_unlock(&c->dc_lock);
- synchronize_rcu();
- c->dc_free_callback(devid);
- return;
- }
- spin_unlock(&c->dc_lock);
- /* Why wasn't it found in the list? */
- BUG();
-}
-EXPORT_SYMBOL_GPL(pnfs_put_deviceid);
-
-/* Find and reference a deviceid */
-struct pnfs_deviceid_node *
-pnfs_find_get_deviceid(struct pnfs_deviceid_cache *c, struct nfs4_deviceid *id)
-{
- struct pnfs_deviceid_node *d;
- struct hlist_node *n;
- long hash = nfs4_deviceid_hash(id);
-
- dprintk("--> %s hash %ld\n", __func__, hash);
- rcu_read_lock();
- hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[hash], de_node) {
- if (!memcmp(&d->de_id, id, sizeof(*id))) {
- if (!atomic_inc_not_zero(&d->de_ref)) {
- goto fail;
- } else {
- rcu_read_unlock();
- return d;
- }
- }
- }
-fail:
- rcu_read_unlock();
- return NULL;
-}
-EXPORT_SYMBOL_GPL(pnfs_find_get_deviceid);
-
-/*
- * Add a deviceid to the cache.
- * GETDEVICEINFOs for same deviceid can race. If deviceid is found, discard new
- */
-struct pnfs_deviceid_node *
-pnfs_add_deviceid(struct pnfs_deviceid_cache *c, struct pnfs_deviceid_node *new)
-{
- struct pnfs_deviceid_node *d;
- long hash = nfs4_deviceid_hash(&new->de_id);
-
- dprintk("--> %s hash %ld\n", __func__, hash);
- spin_lock(&c->dc_lock);
- d = pnfs_find_get_deviceid(c, &new->de_id);
- if (d) {
- spin_unlock(&c->dc_lock);
- dprintk("%s [discard]\n", __func__);
- c->dc_free_callback(new);
- return d;
- }
- INIT_HLIST_NODE(&new->de_node);
- atomic_set(&new->de_ref, 1);
- hlist_add_head_rcu(&new->de_node, &c->dc_deviceids[hash]);
- spin_unlock(&c->dc_lock);
- dprintk("%s [new]\n", __func__);
- return new;
-}
-EXPORT_SYMBOL_GPL(pnfs_add_deviceid);
-
-void
-pnfs_put_deviceid_cache(struct nfs_client *clp)
-{
- struct pnfs_deviceid_cache *local = clp->cl_devid_cache;
-
- dprintk("--> %s ({%d})\n", __func__, atomic_read(&local->dc_ref));
- if (atomic_dec_and_lock(&local->dc_ref, &clp->cl_lock)) {
- int i;
- /* Verify cache is empty */
- for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i++)
- BUG_ON(!hlist_empty(&local->dc_deviceids[i]));
- clp->cl_devid_cache = NULL;
- spin_unlock(&clp->cl_lock);
- kfree(local);
- }
-}
-EXPORT_SYMBOL_GPL(pnfs_put_deviceid_cache);