/*- * Copyright (c) 2009 Isilon Inc http://www.isilon.com/ * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD$ */ /** * @file * * Main header for failpoint facility. */ #ifndef _SYS_FAIL_H_ #define _SYS_FAIL_H_ #include #include #include #include #include #include #include #include #include #include /** * Failpoint return codes, used internally. * @ingroup failpoint_private */ enum fail_point_return_code { FAIL_POINT_RC_CONTINUE = 0, /**< Continue with normal execution */ FAIL_POINT_RC_RETURN, /**< FP evaluated to 'return' */ FAIL_POINT_RC_QUEUED, /**< sleep_fn will be called */ }; struct fail_point_entry; struct fail_point_setting; /** * Internal failpoint structure, tracking all the current details of the * failpoint. This structure is the core component shared between the * failure-injection code and the user-interface. * @ingroup failpoint_private */ struct fail_point { const char *fp_name; /* name of fail point */ const char *fp_location; /* file:line of fail point */ volatile int fp_ref_cnt; /** * protects fp_setting: while holding * a ref, fp_setting points to an * unfreed fail_point_setting */ struct fail_point_setting * volatile fp_setting; int fp_flags; /**< Function to call before sleep or pause */ void (*fp_pre_sleep_fn)(void *); /**< Arg for fp_pre_sleep_fn */ void *fp_pre_sleep_arg; /**< Function to call after waking from sleep or pause */ void (*fp_post_sleep_fn)(void *); /**< Arg for fp_post_sleep_fn */ void *fp_post_sleep_arg; }; #define FAIL_POINT_DYNAMIC_NAME 0x01 /**< Must free name on destroy */ /**< Use timeout path for sleep instead of msleep */ #define FAIL_POINT_USE_TIMEOUT_PATH 0x02 /**< If fail point is set to sleep, replace the sleep call with delay */ #define FAIL_POINT_NONSLEEPABLE 0x04 #define FAIL_POINT_CV_DESC "fp cv no iterators" #define FAIL_POINT_IS_OFF(fp) (__predict_true((fp)->fp_setting == NULL) || \ __predict_true(fail_point_is_off(fp))) __BEGIN_DECLS /* Private failpoint eval function -- use fail_point_eval() instead. */ enum fail_point_return_code fail_point_eval_nontrivial(struct fail_point *, int *ret); /** * @addtogroup failpoint * @{ */ /* * Initialize a fail-point. The name is formed in printf-like fashion * from "fmt" and the subsequent arguments. * Pair with fail_point_destroy(). */ void fail_point_init(struct fail_point *, const char *fmt, ...) __printflike(2, 3); /* Return true iff this fail point is set to off, false otherwise */ bool fail_point_is_off(struct fail_point *fp); /** * Set the pre-sleep function for a fail point * If fp_post_sleep_fn is specified, then FAIL_POINT_SLEEP will result in a * (*fp->fp_pre_sleep_fn)(fp->fp_pre_sleep_arg) call by the thread. */ static inline void fail_point_sleep_set_pre_func(struct fail_point *fp, void (*sleep_fn)(void *)) { fp->fp_pre_sleep_fn = sleep_fn; } static inline void fail_point_sleep_set_pre_arg(struct fail_point *fp, void *sleep_arg) { fp->fp_pre_sleep_arg = sleep_arg; } /** * Set the post-sleep function. This will be passed to timeout if we take * the timeout path. This must be set if you sleep using the timeout path. */ static inline void fail_point_sleep_set_post_func(struct fail_point *fp, void (*sleep_fn)(void *)) { fp->fp_post_sleep_fn = sleep_fn; } static inline void fail_point_sleep_set_post_arg(struct fail_point *fp, void *sleep_arg) { fp->fp_post_sleep_arg = sleep_arg; } /** * If the FAIL_POINT_USE_TIMEOUT flag is set on a failpoint, then * FAIL_POINT_SLEEP will result in a call to timeout instead of * msleep. Note that if you sleep while this flag is set, you must * set fp_post_sleep_fn or an error will occur upon waking. */ static inline void fail_point_use_timeout_path(struct fail_point *fp, bool use_timeout, void (*post_sleep_fn)(void *)) { KASSERT(!use_timeout || post_sleep_fn != NULL || (post_sleep_fn == NULL && fp->fp_post_sleep_fn != NULL), ("Setting fp to use timeout, but not setting post_sleep_fn\n")); if (use_timeout) fp->fp_flags |= FAIL_POINT_USE_TIMEOUT_PATH; else fp->fp_flags &= ~FAIL_POINT_USE_TIMEOUT_PATH; if (post_sleep_fn != NULL) fp->fp_post_sleep_fn = post_sleep_fn; } /** * Free the resources used by a fail-point. Pair with fail_point_init(). */ void fail_point_destroy(struct fail_point *); /** * Evaluate a failpoint. */ static inline enum fail_point_return_code fail_point_eval(struct fail_point *fp, int *ret) { if (__predict_true(fp->fp_setting == NULL)) return (FAIL_POINT_RC_CONTINUE); return (fail_point_eval_nontrivial(fp, ret)); } __END_DECLS /* Declare a fail_point and its sysctl in a function. */ #define _FAIL_POINT_NAME(name) _fail_point_##name #define _FAIL_POINT_LOCATION() "(" __FILE__ ":" __XSTRING(__LINE__) ")" #define _FAIL_POINT_INIT(parent, name, flags) \ static struct fail_point _FAIL_POINT_NAME(name) = { \ .fp_name = #name, \ .fp_location = _FAIL_POINT_LOCATION(), \ .fp_ref_cnt = 0, \ .fp_setting = NULL, \ .fp_flags = (flags), \ .fp_pre_sleep_fn = NULL, \ .fp_pre_sleep_arg = NULL, \ .fp_post_sleep_fn = NULL, \ .fp_post_sleep_arg = NULL, \ }; \ SYSCTL_OID(parent, OID_AUTO, name, \ CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, \ &_FAIL_POINT_NAME(name), 0, fail_point_sysctl, \ "A", ""); \ SYSCTL_OID(parent, OID_AUTO, status_##name, \ CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, \ &_FAIL_POINT_NAME(name), 0, \ fail_point_sysctl_status, "A", ""); #define _FAIL_POINT_EVAL(name, cond, code...) \ int RETURN_VALUE; \ \ if (__predict_false(cond && \ fail_point_eval(&_FAIL_POINT_NAME(name), &RETURN_VALUE))) { \ \ code; \ \ } /** * Instantiate a failpoint which returns "RETURN_VALUE" from the function * when triggered. * @param parent The parent sysctl under which to locate the fp's sysctl * @param name The name of the failpoint in the sysctl tree (and printouts) * @return Instantly returns the RETURN_VALUE specified in the * failpoint, if triggered. */ #define KFAIL_POINT_RETURN(parent, name) \ KFAIL_POINT_CODE(parent, name, return RETURN_VALUE) /** * Instantiate a failpoint which returns (void) from the function when * triggered. * @param parent The parent sysctl under which to locate the sysctl * @param name The name of the failpoint in the sysctl tree (and printouts) * @return Instantly returns void, if triggered in the failpoint. */ #define KFAIL_POINT_RETURN_VOID(parent, name) \ KFAIL_POINT_CODE(parent, name, return) /** * Instantiate a failpoint which sets an error when triggered. * @param parent The parent sysctl under which to locate the sysctl * @param name The name of the failpoint in the sysctl tree (and * printouts) * @param error_var A variable to set to the failpoint's specified * return-value when triggered */ #define KFAIL_POINT_ERROR(parent, name, error_var) \ KFAIL_POINT_CODE(parent, name, (error_var) = RETURN_VALUE) /** * Instantiate a failpoint which sets an error and then goes to a * specified label in the function when triggered. * @param parent The parent sysctl under which to locate the sysctl * @param name The name of the failpoint in the sysctl tree (and * printouts) * @param error_var A variable to set to the failpoint's specified * return-value when triggered * @param label The location to goto when triggered. */ #define KFAIL_POINT_GOTO(parent, name, error_var, label) \ KFAIL_POINT_CODE(parent, name, (error_var) = RETURN_VALUE; goto label) /** * Instantiate a failpoint which sets its pre- and post-sleep callback * mechanisms. * @param parent The parent sysctl under which to locate the sysctl * @param name The name of the failpoint in the sysctl tree (and * printouts) * @param pre_func Function pointer to the pre-sleep function, which will be * called directly before going to sleep. * @param pre_arg Argument to the pre-sleep function * @param post_func Function pointer to the pot-sleep function, which will be * called directly before going to sleep. * @param post_arg Argument to the post-sleep function */ #define KFAIL_POINT_SLEEP_CALLBACKS(parent, name, pre_func, pre_arg, \ post_func, post_arg) \ KFAIL_POINT_CODE_SLEEP_CALLBACKS(parent, name, pre_func, \ pre_arg, post_func, post_arg, return RETURN_VALUE) /** * Instantiate a failpoint which runs arbitrary code when triggered, and sets * its pre- and post-sleep callback mechanisms * @param parent The parent sysctl under which to locate the sysctl * @param name The name of the failpoint in the sysctl tree (and * printouts) * @param pre_func Function pointer to the pre-sleep function, which will be * called directly before going to sleep. * @param pre_arg Argument to the pre-sleep function * @param post_func Function pointer to the pot-sleep function, which will be * called directly before going to sleep. * @param post_arg Argument to the post-sleep function * @param code The arbitrary code to run when triggered. Can reference * "RETURN_VALUE" if desired to extract the specified * user return-value when triggered. Note that this is * implemented with a do-while loop so be careful of * break and continue statements. */ #define KFAIL_POINT_CODE_SLEEP_CALLBACKS(parent, name, pre_func, pre_arg, \ post_func, post_arg, code...) \ do { \ _FAIL_POINT_INIT(parent, name) \ _FAIL_POINT_NAME(name).fp_pre_sleep_fn = pre_func; \ _FAIL_POINT_NAME(name).fp_pre_sleep_arg = pre_arg; \ _FAIL_POINT_NAME(name).fp_post_sleep_fn = post_func; \ _FAIL_POINT_NAME(name).fp_post_sleep_arg = post_arg; \ _FAIL_POINT_EVAL(name, true, code) \ } while (0) /** * Instantiate a failpoint which runs arbitrary code when triggered. * @param parent The parent sysctl under which to locate the sysctl * @param name The name of the failpoint in the sysctl tree * (and printouts) * @param code The arbitrary code to run when triggered. Can reference * "RETURN_VALUE" if desired to extract the specified * user return-value when triggered. Note that this is * implemented with a do-while loop so be careful of * break and continue statements. */ #define KFAIL_POINT_CODE(parent, name, code...) \ do { \ _FAIL_POINT_INIT(parent, name, 0) \ _FAIL_POINT_EVAL(name, true, code) \ } while (0) #define KFAIL_POINT_CODE_FLAGS(parent, name, flags, code...) \ do { \ _FAIL_POINT_INIT(parent, name, flags) \ _FAIL_POINT_EVAL(name, true, code) \ } while (0) #define KFAIL_POINT_CODE_COND(parent, name, cond, flags, code...) \ do { \ _FAIL_POINT_INIT(parent, name, flags) \ _FAIL_POINT_EVAL(name, cond, code) \ } while (0) /** * @} * (end group failpoint) */ #ifdef _KERNEL int fail_point_sysctl(SYSCTL_HANDLER_ARGS); int fail_point_sysctl_status(SYSCTL_HANDLER_ARGS); /* The fail point sysctl tree. */ SYSCTL_DECL(_debug_fail_point); #define DEBUG_FP _debug_fail_point #endif #endif /* _SYS_FAIL_H_ */