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, 253 insertions, 0 deletions

diff --git a/drivers/staging/lustre/lnet/selftest/timer.c b/drivers/staging/lustre/lnet/selftest/timer.c
new file mode 100644
index 000000000000..2c078550277b
--- /dev/null
+++ b/drivers/staging/lustre/lnet/selftest/timer.c
@@ -0,0 +1,253 @@
+/*
+ * 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.
+ *
+ * lnet/selftest/timer.c
+ *
+ * Author: Isaac Huang <isaac@clusterfs.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_LNET
+
+#include "selftest.h"
+
+
+/*
+ * Timers are implemented as a sorted queue of expiry times. The queue
+ * is slotted, with each slot holding timers which expire in a
+ * 2**STTIMER_MINPOLL (8) second period. The timers in each slot are
+ * sorted by increasing expiry time. The number of slots is 2**7 (128),
+ * to cover a time period of 1024 seconds into the future before wrapping.
+ */
+#define STTIMER_MINPOLL	3   /* log2 min poll interval (8 s) */
+#define STTIMER_SLOTTIME       (1 << STTIMER_MINPOLL)
+#define STTIMER_SLOTTIMEMASK   (~(STTIMER_SLOTTIME - 1))
+#define STTIMER_NSLOTS	       (1 << 7)
+#define STTIMER_SLOT(t)	       (&stt_data.stt_hash[(((t) >> STTIMER_MINPOLL) & \
+						    (STTIMER_NSLOTS - 1))])
+
+struct st_timer_data {
+	spinlock_t	 stt_lock;
+	/* start time of the slot processed previously */
+	cfs_time_t       stt_prev_slot;
+	struct list_head       stt_hash[STTIMER_NSLOTS];
+	int	      stt_shuttingdown;
+	wait_queue_head_t      stt_waitq;
+	int	      stt_nthreads;
+} stt_data;
+
+void
+stt_add_timer(stt_timer_t *timer)
+{
+	struct list_head *pos;
+
+	spin_lock(&stt_data.stt_lock);
+
+	LASSERT (stt_data.stt_nthreads > 0);
+	LASSERT (!stt_data.stt_shuttingdown);
+	LASSERT (timer->stt_func != NULL);
+	LASSERT (list_empty(&timer->stt_list));
+	LASSERT (cfs_time_after(timer->stt_expires, cfs_time_current_sec()));
+
+	/* a simple insertion sort */
+	list_for_each_prev (pos, STTIMER_SLOT(timer->stt_expires)) {
+		stt_timer_t *old = list_entry(pos, stt_timer_t, stt_list);
+
+		if (cfs_time_aftereq(timer->stt_expires, old->stt_expires))
+			break;
+	}
+	list_add(&timer->stt_list, pos);
+
+	spin_unlock(&stt_data.stt_lock);
+}
+
+/*
+ * The function returns whether it has deactivated a pending timer or not.
+ * (ie. del_timer() of an inactive timer returns 0, del_timer() of an
+ * active timer returns 1.)
+ *
+ * CAVEAT EMPTOR:
+ * When 0 is returned, it is possible that timer->stt_func _is_ running on
+ * another CPU.
+ */
+int
+stt_del_timer (stt_timer_t *timer)
+{
+	int ret = 0;
+
+	spin_lock(&stt_data.stt_lock);
+
+	LASSERT (stt_data.stt_nthreads > 0);
+	LASSERT (!stt_data.stt_shuttingdown);
+
+	if (!list_empty(&timer->stt_list)) {
+		ret = 1;
+		list_del_init(&timer->stt_list);
+	}
+
+	spin_unlock(&stt_data.stt_lock);
+	return ret;
+}
+
+/* called with stt_data.stt_lock held */
+int
+stt_expire_list (struct list_head *slot, cfs_time_t now)
+{
+	int	  expired = 0;
+	stt_timer_t *timer;
+
+	while (!list_empty(slot)) {
+		timer = list_entry(slot->next, stt_timer_t, stt_list);
+
+		if (cfs_time_after(timer->stt_expires, now))
+			break;
+
+		list_del_init(&timer->stt_list);
+		spin_unlock(&stt_data.stt_lock);
+
+		expired++;
+		(*timer->stt_func) (timer->stt_data);
+
+		spin_lock(&stt_data.stt_lock);
+	}
+
+	return expired;
+}
+
+int
+stt_check_timers (cfs_time_t *last)
+{
+	int	expired = 0;
+	cfs_time_t now;
+	cfs_time_t this_slot;
+
+	now = cfs_time_current_sec();
+	this_slot = now & STTIMER_SLOTTIMEMASK;
+
+	spin_lock(&stt_data.stt_lock);
+
+	while (cfs_time_aftereq(this_slot, *last)) {
+		expired += stt_expire_list(STTIMER_SLOT(this_slot), now);
+		this_slot = cfs_time_sub(this_slot, STTIMER_SLOTTIME);
+	}
+
+	*last = now & STTIMER_SLOTTIMEMASK;
+	spin_unlock(&stt_data.stt_lock);
+	return expired;
+}
+
+
+int
+stt_timer_main (void *arg)
+{
+	int rc = 0;
+	UNUSED(arg);
+
+	SET_BUT_UNUSED(rc);
+
+	cfs_block_allsigs();
+
+	while (!stt_data.stt_shuttingdown) {
+		stt_check_timers(&stt_data.stt_prev_slot);
+
+		rc = wait_event_timeout(stt_data.stt_waitq,
+					stt_data.stt_shuttingdown,
+					cfs_time_seconds(STTIMER_SLOTTIME));
+	}
+
+	spin_lock(&stt_data.stt_lock);
+	stt_data.stt_nthreads--;
+	spin_unlock(&stt_data.stt_lock);
+	return 0;
+}
+
+int
+stt_start_timer_thread (void)
+{
+	task_t *task;
+
+	LASSERT(!stt_data.stt_shuttingdown);
+
+	task = kthread_run(stt_timer_main, NULL, "st_timer");
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+
+	spin_lock(&stt_data.stt_lock);
+	stt_data.stt_nthreads++;
+	spin_unlock(&stt_data.stt_lock);
+	return 0;
+}
+
+
+int
+stt_startup (void)
+{
+	int rc = 0;
+	int i;
+
+	stt_data.stt_shuttingdown = 0;
+	stt_data.stt_prev_slot = cfs_time_current_sec() & STTIMER_SLOTTIMEMASK;
+
+	spin_lock_init(&stt_data.stt_lock);
+	for (i = 0; i < STTIMER_NSLOTS; i++)
+		INIT_LIST_HEAD(&stt_data.stt_hash[i]);
+
+	stt_data.stt_nthreads = 0;
+	init_waitqueue_head(&stt_data.stt_waitq);
+	rc = stt_start_timer_thread();
+	if (rc != 0)
+		CERROR ("Can't spawn timer thread: %d\n", rc);
+
+	return rc;
+}
+
+void
+stt_shutdown (void)
+{
+	int i;
+
+	spin_lock(&stt_data.stt_lock);
+
+	for (i = 0; i < STTIMER_NSLOTS; i++)
+		LASSERT (list_empty(&stt_data.stt_hash[i]));
+
+	stt_data.stt_shuttingdown = 1;
+
+	wake_up(&stt_data.stt_waitq);
+	lst_wait_until(stt_data.stt_nthreads == 0, stt_data.stt_lock,
+		       "waiting for %d threads to terminate\n",
+		       stt_data.stt_nthreads);
+
+	spin_unlock(&stt_data.stt_lock);
+}