Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932412AbWHWLfj (ORCPT ); Wed, 23 Aug 2006 07:35:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932389AbWHWLfG (ORCPT ); Wed, 23 Aug 2006 07:35:06 -0400 Received: from ns.miraclelinux.com ([219.118.163.66]:58712 "EHLO mail01.miraclelinux.com") by vger.kernel.org with ESMTP id S932407AbWHWLe6 (ORCPT ); Wed, 23 Aug 2006 07:34:58 -0400 Message-Id: <20060823113316.560762676@localhost.localdomain> References: <20060823113243.210352005@localhost.localdomain> Date: Wed, 23 Aug 2006 20:32:44 +0900 From: Akinobu Mita To: linux-kernel@vger.kernel.org Cc: akpm@osdl.org, okuji@enbug.org, Akinobu Mita Subject: [patch 1/5] fail-injection library Content-Disposition: inline; filename=should-fail.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4430 Lines: 165 This patch provides several functions for implement fail-injection capabilities. Signed-off-by: Akinobu Mita include/linux/should_fail.h | 44 ++++++++++++++++++++++++++++ lib/Kconfig.debug | 4 ++ lib/Makefile | 1 lib/should_fail.c | 69 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 118 insertions(+) Index: work-failmalloc/include/linux/should_fail.h =================================================================== --- /dev/null +++ work-failmalloc/include/linux/should_fail.h @@ -0,0 +1,44 @@ +#ifndef _LINUX_SHOULD_FAIL_H +#define _LINUX_SHOULD_FAIL_H + +#ifdef CONFIG_SHOULD_FAIL + +#include +#include + +struct should_fail_data { + + /* how often it should fail in percent. */ + unsigned long probability; + + /* the interval of failures. */ + unsigned long interval; + + /* + * how many times failures may happen at most. + * A value of '-1' means infinity. + */ + atomic_t times; + + /* + * the size of free space where memory can be allocated safely. + * A value of '0' means infinity. + */ + atomic_t space; + + unsigned long count; +}; + +#define DEFINE_SHOULD_FAIL(name) \ + struct should_fail_data name = { .times = ATOMIC_INIT(-1), } + +int should_fail(struct should_fail_data *data, unsigned long size); +int setup_should_fail(struct should_fail_data *data, char *str); + +#else + +#define should_fail(data, size) (0) + +#endif /* CONFIG_SHOULD_FAIL */ + +#endif /* _LINUX_SHOULD_FAIL_H */ Index: work-failmalloc/lib/should_fail.c =================================================================== --- /dev/null +++ work-failmalloc/lib/should_fail.c @@ -0,0 +1,69 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +int setup_should_fail(struct should_fail_data *data, char *str) +{ + unsigned long probability; + unsigned long interval; + int times; + int space; + + /* ",,," */ + if (sscanf(str, "%lu,%lu,%d,%d", &probability, &interval, ×, + &space) < 4) + return 0; + + data->probability = probability; + data->interval = interval; + atomic_set(&data->times, times); + atomic_set(&data->space, space); + + return 1; +} + +#define failure_probability(data) (data)->probability +#define failure_interval(data) (data)->interval +#define max_failures(data) (data)->times +#define current_space(data) (data)->space +#define atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0) + +/* + * This function is almost taken from failmalloc-1.0 + * http://www.nongnu.org/failmalloc/ + */ + +int should_fail(struct should_fail_data *data, unsigned long size) +{ + if (atomic_read(&max_failures(data)) == 0) + return 0; + + if (atomic_read(¤t_space(data)) > size) { + atomic_sub(size, ¤t_space(data)); + return 0; + } + + if (failure_interval(data) > 1) { + data->count++; + if (data->count % failure_interval(data)) + return 0; + } + + if (failure_probability(data) == 100 || + INT_MAX / 100 * failure_probability(data) > get_random_int()) + goto fail; + + return 0; + +fail: + + if (atomic_read(&max_failures(data)) != -1) + atomic_dec_not_zero(&max_failures(data)); + + return 1; +} Index: work-failmalloc/lib/Kconfig.debug =================================================================== --- work-failmalloc.orig/lib/Kconfig.debug +++ work-failmalloc/lib/Kconfig.debug @@ -368,3 +368,7 @@ config RCU_TORTURE_TEST at boot time (you probably don't). Say M if you want the RCU torture tests to build as a module. Say N if you are unsure. + +config SHOULD_FAIL + bool + Index: work-failmalloc/lib/Makefile =================================================================== --- work-failmalloc.orig/lib/Makefile +++ work-failmalloc/lib/Makefile @@ -51,6 +51,7 @@ obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o obj-$(CONFIG_SMP) += percpu_counter.o obj-$(CONFIG_SWIOTLB) += swiotlb.o +obj-$(CONFIG_SHOULD_FAIL) += should_fail.o hostprogs-y := gen_crc32table clean-files := crc32table.h -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/