NFS: Generalise the nfs_client structure

Generalise the nfs_client structure by:

 (1) Moving nfs_client to a more general place (nfs_fs_sb.h).

 (2) Renaming its maintenance routines to be non-NFS4 specific.

 (3) Move those maintenance routines to a new non-NFS4 specific file (client.c)
     and move the declarations to internal.h.

 (4) Make nfs_find/get_client() take a full sockaddr_in to include the port
     number (will be required for NFS2/3).

 (5) Make nfs_find/get_client() take the NFS protocol version (again will be
     required to differentiate NFS2, 3 & 4 client records).

Also:

 (6) Make nfs_client construction proceed akin to inodes, marking them as under
     construction and providing a function to indicate completion.

 (7) Make nfs_get_client() wait interruptibly if it finds a client that it can
     share, but that client is currently being constructed.

 (8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 6 insertions, 122 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index fa51a7d..058811e 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -50,12 +50,12 @@
 #include "nfs4_fs.h"
 #include "callback.h"
 #include "delegation.h"
+#include "internal.h"
 
 #define OPENOWNER_POOL_SIZE	8
 
 const nfs4_stateid zero_stateid;
 
-static DEFINE_SPINLOCK(state_spinlock);
 static LIST_HEAD(nfs4_clientid_list);
 
 void
@@ -71,127 +71,11 @@ destroy_nfsv4_state(struct nfs_server *server)
 	kfree(server->mnt_path);
 	server->mnt_path = NULL;
 	if (server->nfs_client) {
-		nfs4_put_client(server->nfs_client);
+		nfs_put_client(server->nfs_client);
 		server->nfs_client = NULL;
 	}
 }
 
-/*
- * nfs4_get_client(): returns an empty client structure
- * nfs4_put_client(): drops reference to client structure
- *
- * Since these are allocated/deallocated very rarely, we don't
- * bother putting them in a slab cache...
- */
-static struct nfs_client *
-nfs4_alloc_client(struct in_addr *addr)
-{
-	struct nfs_client *clp;
-
-	if (nfs_callback_up() < 0)
-		return NULL;
-	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
-		nfs_callback_down();
-		return NULL;
-	}
-	memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
-	init_rwsem(&clp->cl_sem);
-	INIT_LIST_HEAD(&clp->cl_delegations);
-	INIT_LIST_HEAD(&clp->cl_state_owners);
-	INIT_LIST_HEAD(&clp->cl_unused);
-	spin_lock_init(&clp->cl_lock);
-	atomic_set(&clp->cl_count, 1);
-	INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
-	INIT_LIST_HEAD(&clp->cl_superblocks);
-	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
-	clp->cl_rpcclient = ERR_PTR(-EINVAL);
-	clp->cl_boot_time = CURRENT_TIME;
-	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
-	return clp;
-}
-
-static void
-nfs4_free_client(struct nfs_client *clp)
-{
-	struct nfs4_state_owner *sp;
-
-	while (!list_empty(&clp->cl_unused)) {
-		sp = list_entry(clp->cl_unused.next,
-				struct nfs4_state_owner,
-				so_list);
-		list_del(&sp->so_list);
-		kfree(sp);
-	}
-	BUG_ON(!list_empty(&clp->cl_state_owners));
-	nfs_idmap_delete(clp);
-	if (!IS_ERR(clp->cl_rpcclient))
-		rpc_shutdown_client(clp->cl_rpcclient);
-	kfree(clp);
-	nfs_callback_down();
-}
-
-static struct nfs_client *__nfs4_find_client(struct in_addr *addr)
-{
-	struct nfs_client *clp;
-	list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
-		if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
-			atomic_inc(&clp->cl_count);
-			return clp;
-		}
-	}
-	return NULL;
-}
-
-struct nfs_client *nfs4_find_client(struct in_addr *addr)
-{
-	struct nfs_client *clp;
-	spin_lock(&state_spinlock);
-	clp = __nfs4_find_client(addr);
-	spin_unlock(&state_spinlock);
-	return clp;
-}
-
-struct nfs_client *
-nfs4_get_client(struct in_addr *addr)
-{
-	struct nfs_client *clp, *new = NULL;
-
-	spin_lock(&state_spinlock);
-	for (;;) {
-		clp = __nfs4_find_client(addr);
-		if (clp != NULL)
-			break;
-		clp = new;
-		if (clp != NULL) {
-			list_add(&clp->cl_servers, &nfs4_clientid_list);
-			new = NULL;
-			break;
-		}
-		spin_unlock(&state_spinlock);
-		new = nfs4_alloc_client(addr);
-		spin_lock(&state_spinlock);
-		if (new == NULL)
-			break;
-	}
-	spin_unlock(&state_spinlock);
-	if (new)
-		nfs4_free_client(new);
-	return clp;
-}
-
-void
-nfs4_put_client(struct nfs_client *clp)
-{
-	if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
-		return;
-	list_del(&clp->cl_servers);
-	spin_unlock(&state_spinlock);
-	BUG_ON(!list_empty(&clp->cl_superblocks));
-	rpc_wake_up(&clp->cl_rpcwaitq);
-	nfs4_kill_renewd(clp);
-	nfs4_free_client(clp);
-}
-
 static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
 {
 	int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
@@ -771,11 +655,11 @@ static void nfs4_recover_state(struct nfs_client *clp)
 	__module_get(THIS_MODULE);
 	atomic_inc(&clp->cl_count);
 	task = kthread_run(reclaimer, clp, "%u.%u.%u.%u-reclaim",
-			NIPQUAD(clp->cl_addr));
+			NIPQUAD(clp->cl_addr.sin_addr));
 	if (!IS_ERR(task))
 		return;
 	nfs4_clear_recover_bit(clp);
-	nfs4_put_client(clp);
+	nfs_put_client(clp);
 	module_put(THIS_MODULE);
 }
 
@@ -970,12 +854,12 @@ out:
 	if (status == -NFS4ERR_CB_PATH_DOWN)
 		nfs_handle_cb_pathdown(clp);
 	nfs4_clear_recover_bit(clp);
-	nfs4_put_client(clp);
+	nfs_put_client(clp);
 	module_put_and_exit(0);
 	return 0;
 out_error:
 	printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
-				NIPQUAD(clp->cl_addr.s_addr), -status);
+				NIPQUAD(clp->cl_addr.sin_addr), -status);
 	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
 	goto out;
 }