staging: add Lustre file system client support

Lustre is the most deployed distributed file system
in the HPC (High Performance Computing) world. The patch
adds its client side support.

The code is not very clean and needs to live in drivers/staging
for some time for continuing cleanup work. See
drivers/staging/lustre/TODO for details.

The code is based on Lustre master commit faefbfc04

commit faefbfc0460bc00f2ee4c1c1c86aa1e39b9eea49
Author: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Date:   Tue Apr 30 23:05:21 2013 +0400

    LU-3244 utils: tunefs.lustre should preserve virgin label

Plus a few under-review patches on Whamcloud gerrit:
3.8 kernel support:
http://review.whamcloud.com/#change,5973
http://review.whamcloud.com/#change,5974
http://review.whamcloud.com/#change,5768
http://review.whamcloud.com/#change,5781
http://review.whamcloud.com/#change,5763
http://review.whamcloud.com/#change,5613
http://review.whamcloud.com/#change,5655

3.9 kernel support:
http://review.whamcloud.com/#change,5898
http://review.whamcloud.com/#change,5899

Kconfig/Kbuild:
http://review.whamcloud.com/#change,4646
http://review.whamcloud.com/#change,4644

libcfs cleanup:
http://review.whamcloud.com/#change,2831
http://review.whamcloud.com/#change,4775
http://review.whamcloud.com/#change,4776
http://review.whamcloud.com/#change,4777
http://review.whamcloud.com/#change,4778
http://review.whamcloud.com/#change,4779
http://review.whamcloud.com/#change,4780

All starting/trailing whitespaces are removed, to match kernel
coding style. Also ran scripts/cleanfile on all lustre source files.

[maked the Kconfig depend on BROKEN as the recent procfs changes causes
this to fail - gregkh]

Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 250 insertions, 0 deletions

diff --git a/drivers/staging/lustre/lustre/ptlrpc/sec_gc.c b/drivers/staging/lustre/lustre/ptlrpc/sec_gc.c
new file mode 100644
index 000000000000..4c96a14a1bb6
--- /dev/null
+++ b/drivers/staging/lustre/lustre/ptlrpc/sec_gc.c
@@ -0,0 +1,250 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/ptlrpc/sec_gc.c
+ *
+ * Author: Eric Mei <ericm@clusterfs.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_SEC
+
+#include <linux/libcfs/libcfs.h>
+
+#include <obd_support.h>
+#include <obd_class.h>
+#include <lustre_net.h>
+#include <lustre_sec.h>
+
+#define SEC_GC_INTERVAL (30 * 60)
+
+
+static struct mutex sec_gc_mutex;
+static LIST_HEAD(sec_gc_list);
+static spinlock_t sec_gc_list_lock;
+
+static LIST_HEAD(sec_gc_ctx_list);
+static spinlock_t sec_gc_ctx_list_lock;
+
+static struct ptlrpc_thread sec_gc_thread;
+static atomic_t sec_gc_wait_del = ATOMIC_INIT(0);
+
+
+void sptlrpc_gc_add_sec(struct ptlrpc_sec *sec)
+{
+	LASSERT(sec->ps_policy->sp_cops->gc_ctx);
+	LASSERT(sec->ps_gc_interval > 0);
+	LASSERT(list_empty(&sec->ps_gc_list));
+
+	sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
+
+	spin_lock(&sec_gc_list_lock);
+	list_add_tail(&sec_gc_list, &sec->ps_gc_list);
+	spin_unlock(&sec_gc_list_lock);
+
+	CDEBUG(D_SEC, "added sec %p(%s)\n", sec, sec->ps_policy->sp_name);
+}
+EXPORT_SYMBOL(sptlrpc_gc_add_sec);
+
+void sptlrpc_gc_del_sec(struct ptlrpc_sec *sec)
+{
+	if (list_empty(&sec->ps_gc_list))
+		return;
+
+	might_sleep();
+
+	/* signal before list_del to make iteration in gc thread safe */
+	atomic_inc(&sec_gc_wait_del);
+
+	spin_lock(&sec_gc_list_lock);
+	list_del_init(&sec->ps_gc_list);
+	spin_unlock(&sec_gc_list_lock);
+
+	/* barrier */
+	mutex_lock(&sec_gc_mutex);
+	mutex_unlock(&sec_gc_mutex);
+
+	atomic_dec(&sec_gc_wait_del);
+
+	CDEBUG(D_SEC, "del sec %p(%s)\n", sec, sec->ps_policy->sp_name);
+}
+EXPORT_SYMBOL(sptlrpc_gc_del_sec);
+
+void sptlrpc_gc_add_ctx(struct ptlrpc_cli_ctx *ctx)
+{
+	LASSERT(list_empty(&ctx->cc_gc_chain));
+
+	CDEBUG(D_SEC, "hand over ctx %p(%u->%s)\n",
+	       ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
+	spin_lock(&sec_gc_ctx_list_lock);
+	list_add(&ctx->cc_gc_chain, &sec_gc_ctx_list);
+	spin_unlock(&sec_gc_ctx_list_lock);
+
+	thread_add_flags(&sec_gc_thread, SVC_SIGNAL);
+	wake_up(&sec_gc_thread.t_ctl_waitq);
+}
+EXPORT_SYMBOL(sptlrpc_gc_add_ctx);
+
+static void sec_process_ctx_list(void)
+{
+	struct ptlrpc_cli_ctx *ctx;
+
+	spin_lock(&sec_gc_ctx_list_lock);
+
+	while (!list_empty(&sec_gc_ctx_list)) {
+		ctx = list_entry(sec_gc_ctx_list.next,
+				     struct ptlrpc_cli_ctx, cc_gc_chain);
+		list_del_init(&ctx->cc_gc_chain);
+		spin_unlock(&sec_gc_ctx_list_lock);
+
+		LASSERT(ctx->cc_sec);
+		LASSERT(atomic_read(&ctx->cc_refcount) == 1);
+		CDEBUG(D_SEC, "gc pick up ctx %p(%u->%s)\n",
+		       ctx, ctx->cc_vcred.vc_uid, sec2target_str(ctx->cc_sec));
+		sptlrpc_cli_ctx_put(ctx, 1);
+
+		spin_lock(&sec_gc_ctx_list_lock);
+	}
+
+	spin_unlock(&sec_gc_ctx_list_lock);
+}
+
+static void sec_do_gc(struct ptlrpc_sec *sec)
+{
+	LASSERT(sec->ps_policy->sp_cops->gc_ctx);
+
+	if (unlikely(sec->ps_gc_next == 0)) {
+		CDEBUG(D_SEC, "sec %p(%s) has 0 gc time\n",
+		      sec, sec->ps_policy->sp_name);
+		return;
+	}
+
+	CDEBUG(D_SEC, "check on sec %p(%s)\n", sec, sec->ps_policy->sp_name);
+
+	if (cfs_time_after(sec->ps_gc_next, cfs_time_current_sec()))
+		return;
+
+	sec->ps_policy->sp_cops->gc_ctx(sec);
+	sec->ps_gc_next = cfs_time_current_sec() + sec->ps_gc_interval;
+}
+
+static int sec_gc_main(void *arg)
+{
+	struct ptlrpc_thread *thread = (struct ptlrpc_thread *) arg;
+	struct l_wait_info    lwi;
+
+	unshare_fs_struct();
+
+	/* Record that the thread is running */
+	thread_set_flags(thread, SVC_RUNNING);
+	wake_up(&thread->t_ctl_waitq);
+
+	while (1) {
+		struct ptlrpc_sec *sec;
+
+		thread_clear_flags(thread, SVC_SIGNAL);
+		sec_process_ctx_list();
+again:
+		/* go through sec list do gc.
+		 * FIXME here we iterate through the whole list each time which
+		 * is not optimal. we perhaps want to use balanced binary tree
+		 * to trace each sec as order of expiry time.
+		 * another issue here is we wakeup as fixed interval instead of
+		 * according to each sec's expiry time */
+		mutex_lock(&sec_gc_mutex);
+		list_for_each_entry(sec, &sec_gc_list, ps_gc_list) {
+			/* if someone is waiting to be deleted, let it
+			 * proceed as soon as possible. */
+			if (atomic_read(&sec_gc_wait_del)) {
+				CDEBUG(D_SEC, "deletion pending, start over\n");
+				mutex_unlock(&sec_gc_mutex);
+				goto again;
+			}
+
+			sec_do_gc(sec);
+		}
+		mutex_unlock(&sec_gc_mutex);
+
+		/* check ctx list again before sleep */
+		sec_process_ctx_list();
+
+		lwi = LWI_TIMEOUT(SEC_GC_INTERVAL * HZ, NULL, NULL);
+		l_wait_event(thread->t_ctl_waitq,
+			     thread_is_stopping(thread) ||
+			     thread_is_signal(thread),
+			     &lwi);
+
+		if (thread_test_and_clear_flags(thread, SVC_STOPPING))
+			break;
+	}
+
+	thread_set_flags(thread, SVC_STOPPED);
+	wake_up(&thread->t_ctl_waitq);
+	return 0;
+}
+
+int sptlrpc_gc_init(void)
+{
+	struct l_wait_info lwi = { 0 };
+	task_t *task;
+
+	mutex_init(&sec_gc_mutex);
+	spin_lock_init(&sec_gc_list_lock);
+	spin_lock_init(&sec_gc_ctx_list_lock);
+
+	/* initialize thread control */
+	memset(&sec_gc_thread, 0, sizeof(sec_gc_thread));
+	init_waitqueue_head(&sec_gc_thread.t_ctl_waitq);
+
+	task = kthread_run(sec_gc_main, &sec_gc_thread, "sptlrpc_gc");
+	if (IS_ERR(task)) {
+		CERROR("can't start gc thread: %ld\n", PTR_ERR(task));
+		return PTR_ERR(task);
+	}
+
+	l_wait_event(sec_gc_thread.t_ctl_waitq,
+		     thread_is_running(&sec_gc_thread), &lwi);
+	return 0;
+}
+
+void sptlrpc_gc_fini(void)
+{
+	struct l_wait_info lwi = { 0 };
+
+	thread_set_flags(&sec_gc_thread, SVC_STOPPING);
+	wake_up(&sec_gc_thread.t_ctl_waitq);
+
+	l_wait_event(sec_gc_thread.t_ctl_waitq,
+		     thread_is_stopped(&sec_gc_thread), &lwi);
+}