From: The pNFS Team <linux-nfs@xxxxxxxxxxxxxxx>
Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
---
fs/nfs/pnfs.c | 141 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/nfs4_pnfs.h | 44 ++++++++++++++
include/linux/nfs_fs_sb.h | 1 +
include/linux/pnfs_xdr.h | 5 ++
4 files changed, 191 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 4c78277..e17835e 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -193,3 +193,144 @@ pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
EXPORT_SYMBOL(pnfs_unregister_layoutdriver);
EXPORT_SYMBOL(pnfs_register_layoutdriver);
+
+
+/* Device ID cache. Supports one layout type per struct nfs_client */
+int
+nfs4_alloc_init_deviceid_cache(struct nfs_client *clp,
+ void (*free_callback)(struct kref *))
+{
+ struct nfs4_deviceid_cache *c;
+
+ c = kzalloc(sizeof(struct nfs4_deviceid_cache), GFP_KERNEL);
+ if (!c)
+ return -ENOMEM;
+ spin_lock(&clp->cl_lock);
+ if (clp->cl_devid_cache != NULL) {
+ kref_get(&clp->cl_devid_cache->dc_kref);
+ spin_unlock(&clp->cl_lock);
+ dprintk("%s [kref [%d]]\n", __func__,
+ atomic_read(&clp->cl_devid_cache->dc_kref.refcount));
+ kfree(c);
+ } else {
+ int i;
+
+ spin_lock_init(&c->dc_lock);
+ for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE ; i++)
+ INIT_HLIST_HEAD(&c->dc_deviceids[i]);
+ kref_init(&c->dc_kref);
+ c->dc_free_callback = free_callback;
+ clp->cl_devid_cache = c;
+ spin_unlock(&clp->cl_lock);
+ dprintk("%s [new]\n", __func__);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(nfs4_alloc_init_deviceid_cache);
+
+void
+nfs4_init_deviceid_node(struct nfs4_deviceid *d)
+{
+ INIT_HLIST_NODE(&d->de_node);
+ kref_init(&d->de_kref);
+}
+EXPORT_SYMBOL(nfs4_init_deviceid_node);
+
+struct nfs4_deviceid *
+nfs4_find_deviceid(struct nfs4_deviceid_cache *c, struct pnfs_deviceid *id)
+{
+ struct nfs4_deviceid *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, NFS4_PNFS_DEVICEID4_SIZE)) {
+ rcu_read_unlock();
+ return d;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
+}
+EXPORT_SYMBOL(nfs4_find_deviceid);
+
+/*
+ * Add or kref_get a deviceid.
+ * GETDEVICEINFOs for same deviceid can race. If deviceid is found, discard new
+ */
+struct nfs4_deviceid *
+nfs4_add_deviceid(struct nfs4_deviceid_cache *c, struct nfs4_deviceid *new)
+{
+ struct nfs4_deviceid *d;
+ struct hlist_node *n;
+ long hash = nfs4_deviceid_hash(&new->de_id);
+
+ dprintk("--> %s hash %ld\n", __func__, hash);
+ spin_lock(&c->dc_lock);
+ hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[hash], de_node) {
+ if (!memcmp(&d->de_id, &new->de_id, NFS4_PNFS_DEVICEID4_SIZE)) {
+ spin_unlock(&c->dc_lock);
+ dprintk("%s [discard]\n", __func__);
+ c->dc_free_callback(&new->de_kref);
+ return d;
+ }
+ }
+ 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(nfs4_add_deviceid);
+
+static int
+nfs4_remove_deviceid(struct nfs4_deviceid_cache *c, long hash)
+{
+ struct nfs4_deviceid *d;
+ struct hlist_node *n;
+
+ dprintk("--> %s hash %ld\n", __func__, hash);
+ spin_lock(&c->dc_lock);
+ hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[hash], de_node) {
+ hlist_del_rcu(&d->de_node);
+ spin_unlock(&c->dc_lock);
+ synchronize_rcu();
+ dprintk("%s [%d]\n", __func__,
+ atomic_read(&d->de_kref.refcount));
+ kref_put(&d->de_kref, c->dc_free_callback);
+ return 1;
+ }
+ spin_unlock(&c->dc_lock);
+ return 0;
+}
+
+static void
+nfs4_free_deviceid_cache(struct kref *kref)
+{
+ struct nfs4_deviceid_cache *cache =
+ container_of(kref, struct nfs4_deviceid_cache, dc_kref);
+ long i;
+
+ for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i++)
+ while (nfs4_remove_deviceid(cache, i))
+ ;
+ kfree(cache);
+}
+
+void
+nfs4_put_deviceid_cache(struct nfs_client *clp)
+{
+ struct nfs4_deviceid_cache *tmp = clp->cl_devid_cache;
+ int refcount;
+
+ dprintk("--> %s cl_devid_cache %p\n", __func__, clp->cl_devid_cache);
+ spin_lock(&clp->cl_lock);
+ refcount = atomic_read(&clp->cl_devid_cache->dc_kref.refcount);
+ if (refcount == 1)
+ clp->cl_devid_cache = NULL;
+ spin_unlock(&clp->cl_lock);
+ dprintk("%s [%d]\n", __func__, refcount);
+ kref_put(&tmp->dc_kref, nfs4_free_deviceid_cache);
+}
+EXPORT_SYMBOL(nfs4_put_deviceid_cache);
diff --git a/include/linux/nfs4_pnfs.h b/include/linux/nfs4_pnfs.h
index 7240d7e..a3fa1d2 100644
--- a/include/linux/nfs4_pnfs.h
+++ b/include/linux/nfs4_pnfs.h
@@ -12,6 +12,7 @@
#ifndef LINUX_NFS4_PNFS_H
#define LINUX_NFS4_PNFS_H
+#include <linux/pnfs_xdr.h>
/* Per-layout driver specific registration structure */
struct pnfs_layoutdriver_type {
@@ -34,6 +35,49 @@ struct layoutdriver_io_operations {
struct layoutdriver_policy_operations {
};
+/*
+ * Device ID RCU cache. A device ID is unique per client ID and layout type.
+ */
+#define NFS4_DEVICE_ID_HASH_BITS 5
+#define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS)
+#define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1)
+
+static inline u32
+nfs4_deviceid_hash(struct pnfs_deviceid *id)
+{
+ unsigned char *cptr = (unsigned char *)id->data;
+ unsigned int nbytes = NFS4_PNFS_DEVICEID4_SIZE;
+ u32 x = 0;
+
+ while (nbytes--) {
+ x *= 37;
+ x += *cptr++;
+ }
+ return x & NFS4_DEVICE_ID_HASH_MASK;
+}
+
+struct nfs4_deviceid_cache {
+ spinlock_t dc_lock;
+ struct kref dc_kref;
+ void (*dc_free_callback)(struct kref *);
+ struct hlist_head dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
+};
+
+/* Device ID cache node */
+struct nfs4_deviceid {
+ struct hlist_node de_node;
+ struct pnfs_deviceid de_id;
+ struct kref de_kref;
+};
+
+extern int nfs4_alloc_init_deviceid_cache(struct nfs_client *,
+ void (*free_callback)(struct kref *));
+extern void nfs4_put_deviceid_cache(struct nfs_client *);
+extern void nfs4_init_deviceid_node(struct nfs4_deviceid *);
+extern struct nfs4_deviceid *nfs4_find_deviceid(struct nfs4_deviceid_cache *,
+ struct pnfs_deviceid *);
+extern struct nfs4_deviceid *nfs4_add_deviceid(struct nfs4_deviceid_cache *,
+ struct nfs4_deviceid *);
/* pNFS client callback functions.
* These operations allow the layout driver to access pNFS client
* specific information or call pNFS client->server operations.
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index e683128..4544b52 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -82,6 +82,7 @@ struct nfs_client {
/* The flags used for obtaining the clientid during EXCHANGE_ID */
u32 cl_exchange_flags;
struct nfs4_session *cl_session; /* sharred session */
+ struct nfs4_deviceid_cache *cl_devid_cache; /* pNFS deviceid cache */
#endif /* CONFIG_NFS_V4_1 */
#ifdef CONFIG_NFS_FSCACHE
diff --git a/include/linux/pnfs_xdr.h b/include/linux/pnfs_xdr.h
index bcbfbe0..1decc11 100644
--- a/include/linux/pnfs_xdr.h
+++ b/include/linux/pnfs_xdr.h
@@ -12,5 +12,10 @@
#ifndef LINUX_PNFS_XDR_H
#define LINUX_PNFS_XDR_H
+#define NFS4_PNFS_DEVICEID4_SIZE 16
+
+struct pnfs_deviceid {
+ char data[NFS4_PNFS_DEVICEID4_SIZE];
+};
#endif /* LINUX_PNFS_XDR_H */
--
1.6.2.5
--
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