Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 231 insertions, 0 deletions

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
new file mode 100644
index 0000000..c2e9cfd
--- /dev/null
+++ b/fs/nfs/callback.c
@@ -0,0 +1,231 @@
+/*
+ * linux/fs/nfs/callback.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback handling
+ */
+
+#include <linux/completion.h>
+#include <linux/ip.h>
+#include <linux/module.h>
+#include <linux/smp_lock.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/nfs_fs.h>
+#include <linux/mutex.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+
+#include <net/inet_sock.h>
+
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "internal.h"
+
+#define NFSDBG_FACILITY NFSDBG_CALLBACK
+
+struct nfs_callback_data {
+	unsigned int users;
+	struct svc_rqst *rqst;
+	struct task_struct *task;
+};
+
+static struct nfs_callback_data nfs_callback_info;
+static DEFINE_MUTEX(nfs_callback_mutex);
+static struct svc_program nfs4_callback_program;
+
+unsigned int nfs_callback_set_tcpport;
+unsigned short nfs_callback_tcpport;
+static const int nfs_set_port_min = 0;
+static const int nfs_set_port_max = 65535;
+
+/*
+ * If the kernel has IPv6 support available, always listen for
+ * both AF_INET and AF_INET6 requests.
+ */
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static const sa_family_t	nfs_callback_family = AF_INET6;
+#else
+static const sa_family_t	nfs_callback_family = AF_INET;
+#endif
+
+static int param_set_port(const char *val, struct kernel_param *kp)
+{
+	char *endp;
+	int num = simple_strtol(val, &endp, 0);
+	if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
+		return -EINVAL;
+	*((int *)kp->arg) = num;
+	return 0;
+}
+
+module_param_call(callback_tcpport, param_set_port, param_get_int,
+		 &nfs_callback_set_tcpport, 0644);
+
+/*
+ * This is the callback kernel thread.
+ */
+static int
+nfs_callback_svc(void *vrqstp)
+{
+	int err, preverr = 0;
+	struct svc_rqst *rqstp = vrqstp;
+
+	set_freezable();
+
+	/*
+	 * FIXME: do we really need to run this under the BKL? If so, please
+	 * add a comment about what it's intended to protect.
+	 */
+	lock_kernel();
+	while (!kthread_should_stop()) {
+		/*
+		 * Listen for a request on the socket
+		 */
+		err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
+		if (err == -EAGAIN || err == -EINTR) {
+			preverr = err;
+			continue;
+		}
+		if (err < 0) {
+			if (err != preverr) {
+				printk(KERN_WARNING "%s: unexpected error "
+					"from svc_recv (%d)\n", __func__, err);
+				preverr = err;
+			}
+			schedule_timeout_uninterruptible(HZ);
+			continue;
+		}
+		preverr = err;
+		svc_process(rqstp);
+	}
+	unlock_kernel();
+	return 0;
+}
+
+/*
+ * Bring up the callback thread if it is not already up.
+ */
+int nfs_callback_up(void)
+{
+	struct svc_serv *serv = NULL;
+	int ret = 0;
+
+	mutex_lock(&nfs_callback_mutex);
+	if (nfs_callback_info.users++ || nfs_callback_info.task != NULL)
+		goto out;
+	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE,
+				nfs_callback_family, NULL);
+	ret = -ENOMEM;
+	if (!serv)
+		goto out_err;
+
+	ret = svc_create_xprt(serv, "tcp", nfs_callback_set_tcpport,
+			      SVC_SOCK_ANONYMOUS);
+	if (ret <= 0)
+		goto out_err;
+	nfs_callback_tcpport = ret;
+	dprintk("NFS: Callback listener port = %u (af %u)\n",
+			nfs_callback_tcpport, nfs_callback_family);
+
+	nfs_callback_info.rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
+	if (IS_ERR(nfs_callback_info.rqst)) {
+		ret = PTR_ERR(nfs_callback_info.rqst);
+		nfs_callback_info.rqst = NULL;
+		goto out_err;
+	}
+
+	svc_sock_update_bufs(serv);
+
+	nfs_callback_info.task = kthread_run(nfs_callback_svc,
+					     nfs_callback_info.rqst,
+					     "nfsv4-svc");
+	if (IS_ERR(nfs_callback_info.task)) {
+		ret = PTR_ERR(nfs_callback_info.task);
+		svc_exit_thread(nfs_callback_info.rqst);
+		nfs_callback_info.rqst = NULL;
+		nfs_callback_info.task = NULL;
+		goto out_err;
+	}
+out:
+	/*
+	 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
+	 * svc_prepare_thread increments that. So we need to call svc_destroy
+	 * on both success and failure so that the refcount is 1 when the
+	 * thread exits.
+	 */
+	if (serv)
+		svc_destroy(serv);
+	mutex_unlock(&nfs_callback_mutex);
+	return ret;
+out_err:
+	dprintk("NFS: Couldn't create callback socket or server thread; "
+		"err = %d\n", ret);
+	nfs_callback_info.users--;
+	goto out;
+}
+
+/*
+ * Kill the callback thread if it's no longer being used.
+ */
+void nfs_callback_down(void)
+{
+	mutex_lock(&nfs_callback_mutex);
+	nfs_callback_info.users--;
+	if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) {
+		kthread_stop(nfs_callback_info.task);
+		svc_exit_thread(nfs_callback_info.rqst);
+		nfs_callback_info.rqst = NULL;
+		nfs_callback_info.task = NULL;
+	}
+	mutex_unlock(&nfs_callback_mutex);
+}
+
+static int nfs_callback_authenticate(struct svc_rqst *rqstp)
+{
+	struct nfs_client *clp;
+	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
+
+	/* Don't talk to strangers */
+	clp = nfs_find_client(svc_addr(rqstp), 4);
+	if (clp == NULL)
+		return SVC_DROP;
+
+	dprintk("%s: %s NFSv4 callback!\n", __func__,
+			svc_print_addr(rqstp, buf, sizeof(buf)));
+	nfs_put_client(clp);
+
+	switch (rqstp->rq_authop->flavour) {
+		case RPC_AUTH_NULL:
+			if (rqstp->rq_proc != CB_NULL)
+				return SVC_DENIED;
+			break;
+		case RPC_AUTH_UNIX:
+			break;
+		case RPC_AUTH_GSS:
+			/* FIXME: RPCSEC_GSS handling? */
+		default:
+			return SVC_DENIED;
+	}
+	return SVC_OK;
+}
+
+/*
+ * Define NFS4 callback program
+ */
+static struct svc_version *nfs4_callback_version[] = {
+	[1] = &nfs4_callback_version1,
+};
+
+static struct svc_stat nfs4_callback_stats;
+
+static struct svc_program nfs4_callback_program = {
+	.pg_prog = NFS4_CALLBACK,			/* RPC service number */
+	.pg_nvers = ARRAY_SIZE(nfs4_callback_version),	/* Number of entries */
+	.pg_vers = nfs4_callback_version,		/* version table */
+	.pg_name = "NFSv4 callback",			/* service name */
+	.pg_class = "nfs",				/* authentication class */
+	.pg_stats = &nfs4_callback_stats,
+	.pg_authenticate = nfs_callback_authenticate,
+};