/*- * 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 /** * Failpoint types. * Don't change these without changing fail_type_strings in fail.c. * @ingroup failpoint_private */ enum fail_point_t { FAIL_POINT_OFF, /**< don't fail */ FAIL_POINT_PANIC, /**< panic */ FAIL_POINT_RETURN, /**< return an errorcode */ FAIL_POINT_BREAK, /**< break into the debugger */ FAIL_POINT_PRINT, /**< print a message */ FAIL_POINT_SLEEP, /**< sleep for some msecs */ FAIL_POINT_INVALID, /**< placeholder */ }; /** * 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 */ }; TAILQ_HEAD(fail_point_entries, fail_point_entry); /** * 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 */ struct fail_point_entries fp_entries; /**< list of entries */ int fp_flags; void (*fp_sleep_fn)(void *); /**< Function to call at end of * sleep for sleep failpoints */ void *fp_sleep_arg; /**< Arg for sleep_fn */ }; #define FAIL_POINT_DYNAMIC_NAME 0x01 /**< Must free name on destroy */ /** * Internal structure tracking a single term of a complete failpoint. * @ingroup failpoint_private */ struct fail_point_entry { enum fail_point_t fe_type; /**< type of entry */ int fe_arg; /**< argument to type (e.g. return value) */ int fe_prob; /**< likelihood of firing in millionths */ int fe_count; /**< number of times to fire, 0 means always */ TAILQ_ENTRY(fail_point_entry) fe_entries; /**< next entry in fail point */ }; /* 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); /** * Set the sleep function for a fail point * If sleep_fn is specified, then FAIL_POINT_SLEEP will result in a * (*fp->sleep_fn)(fp->sleep_arg) call by the timer thread. Otherwise, * if sleep_fn is NULL (default), then FAIL_POINT_SLEEP will result in the * fail_point_eval() call sleeping. */ static __inline void fail_point_sleep_set_func(struct fail_point *fp, void (*sleep_fn)(void *)) { fp->fp_sleep_fn = sleep_fn; } /** * Set the argument for the sleep function for a fail point */ static __inline void fail_point_sleep_set_arg(struct fail_point *fp, void *sleep_arg) { fp->fp_sleep_arg = sleep_arg; } /** * 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 (TAILQ_EMPTY(&fp->fp_entries)) { return (FAIL_POINT_RC_CONTINUE); } return (fail_point_eval_nontrivial(fp, ret)); } /* Declare a fail_point and its sysctl in a function. */ #define _FAIL_POINT_NAME(name) _fail_point_##name #define _STRINGIFY_HELPER(x) #x #define _STRINGIFY(x) _STRINGIFY_HELPER(x) #define _FAIL_POINT_LOCATION() __FILE__ ":" _STRINGIFY(__LINE__) /** * Instantiate a failpoint which returns "value" 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 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 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 */ #define KFAIL_POINT_CODE(parent, name, code) \ KFAIL_POINT_START(parent, name) { \ code; \ } FAIL_POINT_END /** * @} * (end group failpoint) */ /** * Internal macro to implement above #defines -- should not be used directly. * @ingroup failpoint_private */ #define KFAIL_POINT_START(parent, name) \ do { \ int RETURN_VALUE; \ static struct fail_point _FAIL_POINT_NAME(name) = { \ #name, \ _FAIL_POINT_LOCATION(), \ TAILQ_HEAD_INITIALIZER( \ _FAIL_POINT_NAME(name).fp_entries), \ 0, \ NULL, NULL, \ }; \ SYSCTL_OID(parent, OID_AUTO, name, \ CTLTYPE_STRING | CTLFLAG_RW, \ &_FAIL_POINT_NAME(name), 0, fail_point_sysctl, \ "A", ""); \ \ if (__predict_false( \ fail_point_eval(&_FAIL_POINT_NAME(name), \ &RETURN_VALUE))) { /** * Internal macro to implement above #defines -- should not be used directly. * @ingroup failpoint_private */ #define FAIL_POINT_END \ } \ } while (0) #ifdef _KERNEL int fail_point_sysctl(SYSCTL_HANDLER_ARGS); /* The fail point sysctl tree. */ SYSCTL_DECL(_debug_fail_point); #endif #define DEBUG_FP _debug_fail_point #endif /* _SYS_FAIL_H_ */