NFSv4.1 move deviceid cache to filelayout driver

[mv-sheeva.git] / fs / nfs / nfs4filelayoutdev.c

diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index f466fed2f46652cfb96c178b037fb10fdc819b97..f594ca35a99657c2c29d4ed03dd975349a27a367 100644 (file)
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -36,6 +36,30 @@
 
 #define NFSDBG_FACILITY                NFSDBG_PNFS_LD
 
+/*
+ * Device ID RCU cache. A device ID is unique per client ID and layout type.
+ */
+#define NFS4_FL_DEVICE_ID_HASH_BITS    5
+#define NFS4_FL_DEVICE_ID_HASH_SIZE    (1 << NFS4_FL_DEVICE_ID_HASH_BITS)
+#define NFS4_FL_DEVICE_ID_HASH_MASK    (NFS4_FL_DEVICE_ID_HASH_SIZE - 1)
+
+static inline u32
+nfs4_fl_deviceid_hash(struct nfs4_deviceid *id)
+{
+       unsigned char *cptr = (unsigned char *)id->data;
+       unsigned int nbytes = NFS4_DEVICEID4_SIZE;
+       u32 x = 0;
+
+       while (nbytes--) {
+               x *= 37;
+               x += *cptr++;
+       }
+       return x & NFS4_FL_DEVICE_ID_HASH_MASK;
+}
+
+static struct hlist_head filelayout_deviceid_cache[NFS4_FL_DEVICE_ID_HASH_SIZE];
+static DEFINE_SPINLOCK(filelayout_deviceid_lock);
+
 /*
  * Data server cache
  *
@@ -183,7 +207,7 @@ nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
        struct nfs4_pnfs_ds *ds;
        int i;
 
-       print_deviceid(&dsaddr->deviceid.de_id);
+       print_deviceid(&dsaddr->deviceid);
 
        for (i = 0; i < dsaddr->ds_num; i++) {
                ds = dsaddr->ds_list[i];
@@ -200,15 +224,6 @@ nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
        kfree(dsaddr);
 }
 
-void
-nfs4_fl_free_deviceid_callback(struct pnfs_deviceid_node *device)
-{
-       struct nfs4_file_layout_dsaddr *dsaddr =
-               container_of(device, struct nfs4_file_layout_dsaddr, deviceid);
-
-       nfs4_fl_free_deviceid(dsaddr);
-}
-
 static struct nfs4_pnfs_ds *
 nfs4_pnfs_ds_add(struct inode *inode, u32 ip_addr, u32 port)
 {
@@ -361,7 +376,7 @@ decode_device(struct inode *ino, struct pnfs_device *pdev)
        dsaddr->stripe_count = cnt;
        dsaddr->ds_num = num;
 
-       memcpy(&dsaddr->deviceid.de_id, &pdev->dev_id, sizeof(pdev->dev_id));
+       memcpy(&dsaddr->deviceid, &pdev->dev_id, sizeof(pdev->dev_id));
 
        /* Go back an read stripe indices */
        p = indicesp;
@@ -411,28 +426,37 @@ out_err:
 }
 
 /*
- * Decode the opaque device specified in 'dev'
- * and add it to the list of available devices.
- * If the deviceid is already cached, nfs4_add_deviceid will return
- * a pointer to the cached struct and throw away the new.
+ * Decode the opaque device specified in 'dev' and add it to the cache of
+ * available devices.
  */
-static struct nfs4_file_layout_dsaddr*
+static struct nfs4_file_layout_dsaddr *
 decode_and_add_device(struct inode *inode, struct pnfs_device *dev)
 {
-       struct nfs4_file_layout_dsaddr *dsaddr;
-       struct pnfs_deviceid_node *d;
+       struct nfs4_file_layout_dsaddr *d, *new;
+       long hash;
 
-       dsaddr = decode_device(inode, dev);
-       if (!dsaddr) {
+       new = decode_device(inode, dev);
+       if (!new) {
                printk(KERN_WARNING "%s: Could not decode or add device\n",
                        __func__);
                return NULL;
        }
 
-       d = pnfs_add_deviceid(NFS_SERVER(inode)->nfs_client->cl_devid_cache,
-                             &dsaddr->deviceid);
+       spin_lock(&filelayout_deviceid_lock);
+       d = nfs4_fl_find_get_deviceid(&new->deviceid);
+       if (d) {
+               spin_unlock(&filelayout_deviceid_lock);
+               nfs4_fl_free_deviceid(new);
+               return d;
+       }
+
+       INIT_HLIST_NODE(&new->node);
+       atomic_set(&new->ref, 1);
+       hash = nfs4_fl_deviceid_hash(&new->deviceid);
+       hlist_add_head_rcu(&new->node, &filelayout_deviceid_cache[hash]);
+       spin_unlock(&filelayout_deviceid_lock);
 
-       return container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
+       return new;
 }
 
 /*
@@ -507,14 +531,38 @@ out_free:
        return dsaddr;
 }
 
-struct nfs4_file_layout_dsaddr *
-nfs4_fl_find_get_deviceid(struct nfs_client *clp, struct nfs4_deviceid *id)
+void
+nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
 {
-       struct pnfs_deviceid_node *d;
+       if (atomic_dec_and_lock(&dsaddr->ref, &filelayout_deviceid_lock)) {
+               hlist_del_rcu(&dsaddr->node);
+               spin_unlock(&filelayout_deviceid_lock);
+
+               synchronize_rcu();
+               nfs4_fl_free_deviceid(dsaddr);
+       }
+}
 
-       d = pnfs_find_get_deviceid(clp->cl_devid_cache, id);
-       return (d == NULL) ? NULL :
-               container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
+struct nfs4_file_layout_dsaddr *
+nfs4_fl_find_get_deviceid(struct nfs4_deviceid *id)
+{
+       struct nfs4_file_layout_dsaddr *d;
+       struct hlist_node *n;
+       long hash = nfs4_fl_deviceid_hash(id);
+
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(d, n, &filelayout_deviceid_cache[hash], node) {
+               if (!memcmp(&d->deviceid, id, sizeof(*id))) {
+                       if (!atomic_inc_not_zero(&d->ref))
+                               goto fail;
+                       rcu_read_unlock();
+                       return d;
+               }
+       }
+fail:
+       rcu_read_unlock();
+       return NULL;
 }
 
 /*