pnfs: CB_NOTIFY_DEVICEID
Note: This functionlaity is incomplete as all layout segments referring to
the 'to be removed device id' need to be reaped, and all in flight I/O drained.
[use be32 res in nfs4_callback_devicenotify]
[use nfs_client to qualify deviceid for cb_notify_deviceid]
[use global deviceid cache for CB_NOTIFY_DEVICEID]
[refactor device cache _lookup_deviceid]
[refactor device cache _find_get_deviceid]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[Bug in new global-device-cache code]
[layout_driver MUST set free_deviceid_node if using dev-cache]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
index 64a4b85..8fd3839 100644
--- a/fs/nfs/pnfs_dev.c
+++ b/fs/nfs/pnfs_dev.c
@@ -66,6 +66,23 @@
return x & NFS4_DEVICE_ID_HASH_MASK;
}
+static struct nfs4_deviceid_node *
+_lookup_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id,
+ long hash)
+{
+ struct nfs4_deviceid_node *d;
+ struct hlist_node *n;
+
+ hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node)
+ if (d->nfs_client == clp && !memcmp(&d->deviceid, id, sizeof(*id))) {
+ if (atomic_read(&d->ref))
+ return d;
+ else
+ continue;
+ }
+ return NULL;
+}
+
/*
* Lookup a deviceid in cache and get a reference count on it if found
*
@@ -73,27 +90,77 @@
* @id deviceid to look up
*/
struct nfs4_deviceid_node *
-nfs4_find_get_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
+_find_get_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id,
+ long hash)
{
struct nfs4_deviceid_node *d;
- struct hlist_node *n;
- long hash = nfs4_deviceid_hash(id);
rcu_read_lock();
- hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node) {
- if (d->nfs_client == clp && !memcmp(&d->deviceid, id, sizeof(*id))) {
- if (!atomic_inc_not_zero(&d->ref))
- goto fail;
- rcu_read_unlock();
- return d;
- }
- }
-fail:
+ d = _lookup_deviceid(clp, id, hash);
+ if (d && !atomic_inc_not_zero(&d->ref))
+ d = NULL;
rcu_read_unlock();
- return NULL;
+ return d;
+}
+
+struct nfs4_deviceid_node *
+nfs4_find_get_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
+{
+ return _find_get_deviceid(clp, id, nfs4_deviceid_hash(id));
}
EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
+/*
+ * Unhash and put deviceid
+ *
+ * @clp nfs_client associated with deviceid
+ * @id the deviceid to unhash
+ *
+ * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
+ */
+struct nfs4_deviceid_node *
+nfs4_unhash_put_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
+{
+ struct nfs4_deviceid_node *d;
+
+ spin_lock(&nfs4_deviceid_lock);
+ rcu_read_lock();
+ d = _lookup_deviceid(clp, id, nfs4_deviceid_hash(id));
+ rcu_read_unlock();
+ if (!d) {
+ spin_unlock(&nfs4_deviceid_lock);
+ return NULL;
+ }
+ hlist_del_init_rcu(&d->node);
+ spin_unlock(&nfs4_deviceid_lock);
+ synchronize_rcu();
+
+ /* balance the initial ref set in pnfs_insert_deviceid */
+ if (atomic_dec_and_test(&d->ref))
+ return d;
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(nfs4_unhash_put_deviceid);
+
+/*
+ * Delete a deviceid from cache
+ *
+ * @clp struct nfs_client qualifying the deviceid
+ * @id deviceid to delete
+ */
+void
+nfs4_delete_deviceid(const struct nfs_client *clp, const struct nfs4_deviceid *id)
+{
+ struct nfs4_deviceid_node *d;
+
+ d = nfs4_unhash_put_deviceid(clp, id);
+ if (!d)
+ return;
+ d->ld->free_deviceid_node(d);
+}
+EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
+
void
nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
const struct pnfs_layoutdriver_type *ld,
@@ -126,13 +193,13 @@
long hash;
spin_lock(&nfs4_deviceid_lock);
- d = nfs4_find_get_deviceid(new->nfs_client, &new->deviceid);
+ hash = nfs4_deviceid_hash(&new->deviceid);
+ d = _find_get_deviceid(new->nfs_client, &new->deviceid, hash);
if (d) {
spin_unlock(&nfs4_deviceid_lock);
return d;
}
- hash = nfs4_deviceid_hash(&new->deviceid);
hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
spin_unlock(&nfs4_deviceid_lock);
