NFSv4.1 move deviceid cache to filelayout driver
No need for generic cache with only one user.
Keep a simple hash of deviceids in the filelayout driver.
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index f466fed..f594ca3 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -37,6 +37,30 @@
#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
*
* Data servers can be mapped to different device ids.
@@ -183,7 +207,7 @@
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 @@
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 @@
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 @@
}
/*
- * 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;
+ }
- return container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
+ 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 new;
}
/*
@@ -507,14 +531,38 @@
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);
- d = pnfs_find_get_deviceid(clp->cl_devid_cache, id);
- return (d == NULL) ? NULL :
- container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
+ synchronize_rcu();
+ nfs4_fl_free_deviceid(dsaddr);
+ }
+}
+
+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;
}
/*