diff options
Diffstat (limited to 'drivers/staging/lustre/lnet/libcfs/fail.c')
| -rw-r--r-- | drivers/staging/lustre/lnet/libcfs/fail.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lnet/libcfs/fail.c b/drivers/staging/lustre/lnet/libcfs/fail.c new file mode 100644 index 000000000000..dadaf7685cbd --- /dev/null +++ b/drivers/staging/lustre/lnet/libcfs/fail.c @@ -0,0 +1,139 @@ +/* + * 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 + * + * Please contact Oracle Corporation, Inc., 500 Oracle Parkway, Redwood Shores, + * CA 94065 USA or visit www.oracle.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, 2015, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Oracle Corporation, Inc. + */ + +#include "../../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); + +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 || cfs_rand() % 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; + } + } + + if ((set == CFS_FAIL_LOC_ORSET || set == CFS_FAIL_LOC_RESET) && + (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; + break; + default: + LASSERTF(0, "called with bad set %u\n", set); + break; + } + + return 1; +} +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; +} +EXPORT_SYMBOL(__cfs_fail_timeout_set); |