Release 4.16 drivers/staging/lustre/lnet/libcfs/fail.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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.gnu.org/licenses
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Oracle Corporation, Inc.
 */

#include <linux/libcfs/libcfs.h>


unsigned long cfs_fail_loc;
EXPORT_SYMBOL(cfs_fail_loc);


unsigned int cfs_fail_val;
EXPORT_SYMBOL(cfs_fail_val);


int cfs_fail_err;
EXPORT_SYMBOL(cfs_fail_err);

DECLARE_WAIT_QUEUE_HEAD(cfs_race_waitq);
EXPORT_SYMBOL(cfs_race_waitq);


int cfs_race_state;
EXPORT_SYMBOL(cfs_race_state);



int __cfs_fail_check_set(u32 id, u32 value, int set)
{
	static atomic_t cfs_fail_count = ATOMIC_INIT(0);

	LASSERT(!(id & CFS_FAIL_ONCE));

	if ((cfs_fail_loc & (CFS_FAILED | CFS_FAIL_ONCE)) ==
	    (CFS_FAILED | CFS_FAIL_ONCE)) {
		atomic_set(&cfs_fail_count, 0); /* paranoia */
		return 0;
	}

	/* Fail 1/cfs_fail_val times */
	if (cfs_fail_loc & CFS_FAIL_RAND) {
		if (cfs_fail_val < 2 || prandom_u32_max(cfs_fail_val) > 0)
			return 0;
	}

	/* Skip the first cfs_fail_val, then fail */
	if (cfs_fail_loc & CFS_FAIL_SKIP) {
		if (atomic_inc_return(&cfs_fail_count) <= cfs_fail_val)
			return 0;
	}

	/* check cfs_fail_val... */
	if (set == CFS_FAIL_LOC_VALUE) {
		if (cfs_fail_val != -1 && cfs_fail_val != value)
			return 0;
	}

	/* Fail cfs_fail_val times, overridden by FAIL_ONCE */
	if (cfs_fail_loc & CFS_FAIL_SOME &&
	    (!(cfs_fail_loc & CFS_FAIL_ONCE) || cfs_fail_val <= 1)) {
		int count = atomic_inc_return(&cfs_fail_count);

		if (count >= cfs_fail_val) {
			set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
			atomic_set(&cfs_fail_count, 0);
			/* we are lost race to increase  */
			if (count > cfs_fail_val)
				return 0;
		}
	}

	/* Take into account the current call for FAIL_ONCE for ORSET only,
         * as RESET is a new fail_loc, it does not change the current call
         */
	if ((set == CFS_FAIL_LOC_ORSET) && (value & CFS_FAIL_ONCE))
		set_bit(CFS_FAIL_ONCE_BIT, &cfs_fail_loc);
	/* Lost race to set CFS_FAILED_BIT. */
	if (test_and_set_bit(CFS_FAILED_BIT, &cfs_fail_loc)) {
		/* If CFS_FAIL_ONCE is valid, only one process can fail,
                 * otherwise multi-process can fail at the same time.
                 */
		if (cfs_fail_loc & CFS_FAIL_ONCE)
			return 0;
	}

	switch (set) {
	case CFS_FAIL_LOC_NOSET:
	case CFS_FAIL_LOC_VALUE:
		break;
	case CFS_FAIL_LOC_ORSET:
		cfs_fail_loc |= value & ~(CFS_FAILED | CFS_FAIL_ONCE);
		break;
	case CFS_FAIL_LOC_RESET:
		cfs_fail_loc = value;
		atomic_set(&cfs_fail_count, 0);
		break;
	default:
		LASSERTF(0, "called with bad set %u\n", set);
		break;
	}

	return 1;
}
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CommitProp
Peng Tao
289
95.07%
1
16.67%
Bobi Jam
8
2.63%
1
16.67%
Neil Brown
3
0.99%
1
16.67%
James Simmons
2
0.66%
1
16.67%
Oleg Drokin
1
0.33%
1
16.67%
Vitaly Fertman
1
0.33%
1
16.67%
Total
304
100.00%
6
100.00%

EXPORT_SYMBOL(__cfs_fail_check_set);



int __cfs_fail_timeout_set(u32 id, u32 value, int ms, int set)
{
	int ret;

	ret = __cfs_fail_check_set(id, value, set);
	if (ret && likely(ms > 0)) {
		CERROR("cfs_fail_timeout id %x sleeping for %dms\n",
		       id, ms);
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule_timeout(cfs_time_seconds(ms) / 1000);
		CERROR("cfs_fail_timeout id %x awake\n", id);
	}
	return ret;
}
Contributors
Person
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CommitProp
Peng Tao
69
88.46%
2
50.00%
Fan Yong
7
8.97%
1
25.00%
James Simmons
2
2.56%
1
25.00%
Total
78
100.00%
4
100.00%

EXPORT_SYMBOL(__cfs_fail_timeout_set);
Overall Contributors
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CommitProp
Peng Tao
394
88.94%
2
13.33%
James Simmons
17
3.84%
4
26.67%
Anil Belur
9
2.03%
1
6.67%
Bobi Jam
8
1.81%
1
6.67%
Fan Yong
7
1.58%
1
6.67%
Neil Brown
3
0.68%
1
6.67%
Oleg Drokin
2
0.45%
2
13.33%
Vitaly Fertman
1
0.23%
1
6.67%
Andreas Dilger
1
0.23%
1
6.67%
Greg Kroah-Hartman
1
0.23%
1
6.67%
Total
443
100.00%
15
100.00%
Directory: drivers/staging/lustre/lnet/libcfs

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