zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/nfs/pnfs_dev.c b/ap/os/linux/linux-3.4.x/fs/nfs/pnfs_dev.c
new file mode 100644
index 0000000..73f701f
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nfs/pnfs_dev.c
@@ -0,0 +1,278 @@
+/*
+ * Device operations for the pnfs client.
+ *
+ * Copyright (c) 2002
+ * The Regents of the University of Michigan
+ * All Rights Reserved
+ *
+ * Dean Hildebrand <dhildebz@umich.edu>
+ * Garth Goodson <Garth.Goodson@netapp.com>
+ *
+ * Permission is granted to use, copy, create derivative works, and
+ * redistribute this software and such derivative works for any purpose,
+ * so long as the name of the University of Michigan is not used in
+ * any advertising or publicity pertaining to the use or distribution
+ * of this software without specific, written prior authorization. If
+ * the above copyright notice or any other identification of the
+ * University of Michigan is included in any copy of any portion of
+ * this software, then the disclaimer below must also be included.
+ *
+ * This software is provided as is, without representation or warranty
+ * of any kind either express or implied, including without limitation
+ * the implied warranties of merchantability, fitness for a particular
+ * purpose, or noninfringement. The Regents of the University of
+ * Michigan shall not be liable for any damages, including special,
+ * indirect, incidental, or consequential damages, with respect to any
+ * claim arising out of or in connection with the use of the software,
+ * even if it has been or is hereafter advised of the possibility of
+ * such damages.
+ */
+
+#include <linux/export.h>
+#include "pnfs.h"
+
+#define NFSDBG_FACILITY NFSDBG_PNFS
+
+/*
+ * Device ID RCU cache. A device ID is unique per server 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 struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
+static DEFINE_SPINLOCK(nfs4_deviceid_lock);
+
+#ifdef NFS_DEBUG
+void
+nfs4_print_deviceid(const struct nfs4_deviceid *id)
+{
+ u32 *p = (u32 *)id;
+
+ dprintk("%s: device id= [%x%x%x%x]\n", __func__,
+ p[0], p[1], p[2], p[3]);
+}
+EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
+#endif
+
+static inline u32
+nfs4_deviceid_hash(const 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_DEVICE_ID_HASH_MASK;
+}
+
+static struct nfs4_deviceid_node *
+_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
+ 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->ld == ld && 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
+ *
+ * @clp nfs_client associated with deviceid
+ * @id deviceid to look up
+ */
+static struct nfs4_deviceid_node *
+_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
+ const struct nfs_client *clp, const struct nfs4_deviceid *id,
+ long hash)
+{
+ struct nfs4_deviceid_node *d;
+
+ rcu_read_lock();
+ d = _lookup_deviceid(ld, clp, id, hash);
+ if (d != NULL)
+ atomic_inc(&d->ref);
+ rcu_read_unlock();
+ return d;
+}
+
+struct nfs4_deviceid_node *
+nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
+ const struct nfs_client *clp, const struct nfs4_deviceid *id)
+{
+ return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
+}
+EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
+
+/*
+ * Remove a deviceid from cache
+ *
+ * @clp nfs_client associated with deviceid
+ * @id the deviceid to unhash
+ *
+ * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
+ */
+void
+nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
+ 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(ld, clp, id, nfs4_deviceid_hash(id));
+ rcu_read_unlock();
+ if (!d) {
+ spin_unlock(&nfs4_deviceid_lock);
+ return;
+ }
+ 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))
+ 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,
+ const struct nfs_client *nfs_client,
+ const struct nfs4_deviceid *id)
+{
+ INIT_HLIST_NODE(&d->node);
+ INIT_HLIST_NODE(&d->tmpnode);
+ d->ld = ld;
+ d->nfs_client = nfs_client;
+ d->flags = 0;
+ d->deviceid = *id;
+ atomic_set(&d->ref, 1);
+}
+EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
+
+/*
+ * Uniquely initialize and insert a deviceid node into cache
+ *
+ * @new new deviceid node
+ * Note that the caller must set up the following members:
+ * new->ld
+ * new->nfs_client
+ * new->deviceid
+ *
+ * @ret the inserted node, if none found, otherwise, the found entry.
+ */
+struct nfs4_deviceid_node *
+nfs4_insert_deviceid_node(struct nfs4_deviceid_node *new)
+{
+ struct nfs4_deviceid_node *d;
+ long hash;
+
+ spin_lock(&nfs4_deviceid_lock);
+ hash = nfs4_deviceid_hash(&new->deviceid);
+ d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash);
+ if (d) {
+ spin_unlock(&nfs4_deviceid_lock);
+ return d;
+ }
+
+ hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
+ spin_unlock(&nfs4_deviceid_lock);
+ atomic_inc(&new->ref);
+
+ return new;
+}
+EXPORT_SYMBOL_GPL(nfs4_insert_deviceid_node);
+
+/*
+ * Dereference a deviceid node and delete it when its reference count drops
+ * to zero.
+ *
+ * @d deviceid node to put
+ *
+ * return true iff the node was deleted
+ * Note that since the test for d->ref == 0 is sufficient to establish
+ * that the node is no longer hashed in the global device id cache.
+ */
+bool
+nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
+{
+ if (!atomic_dec_and_test(&d->ref))
+ return false;
+ d->ld->free_deviceid_node(d);
+ return true;
+}
+EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
+
+static void
+_deviceid_purge_client(const struct nfs_client *clp, long hash)
+{
+ struct nfs4_deviceid_node *d;
+ struct hlist_node *n;
+ HLIST_HEAD(tmp);
+
+ spin_lock(&nfs4_deviceid_lock);
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node)
+ if (d->nfs_client == clp && atomic_read(&d->ref)) {
+ hlist_del_init_rcu(&d->node);
+ hlist_add_head(&d->tmpnode, &tmp);
+ }
+ rcu_read_unlock();
+ spin_unlock(&nfs4_deviceid_lock);
+
+ if (hlist_empty(&tmp))
+ return;
+
+ synchronize_rcu();
+ while (!hlist_empty(&tmp)) {
+ d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
+ hlist_del(&d->tmpnode);
+ if (atomic_dec_and_test(&d->ref))
+ d->ld->free_deviceid_node(d);
+ }
+}
+
+void
+nfs4_deviceid_purge_client(const struct nfs_client *clp)
+{
+ long h;
+
+ if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
+ return;
+ for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
+ _deviceid_purge_client(clp, h);
+}
+
+/*
+ * Stop use of all deviceids associated with an nfs_client
+ */
+void
+nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
+{
+ struct nfs4_deviceid_node *d;
+ struct hlist_node *n;
+ int i;
+
+ rcu_read_lock();
+ for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
+ hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[i], node)
+ if (d->nfs_client == clp)
+ set_bit(NFS_DEVICEID_INVALID, &d->flags);
+ }
+ rcu_read_unlock();
+}