diff --git a/config/spl-build.m4 b/config/spl-build.m4 index b0e334815..7d744db13 100644 --- a/config/spl-build.m4 +++ b/config/spl-build.m4 @@ -27,8 +27,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [ SPL_AC_TYPE_ATOMIC64_XCHG SPL_AC_TYPE_UINTPTR_T SPL_AC_2ARGS_REGISTER_SYSCTL - SPL_AC_SET_SHRINKER - SPL_AC_3ARGS_SHRINKER_CALLBACK + SPL_AC_SHRINKER_CALLBACK SPL_AC_PATH_IN_NAMEIDATA SPL_AC_TASK_CURR SPL_AC_CTL_UNNUMBERED @@ -885,37 +884,18 @@ AC_DEFUN([SPL_AC_2ARGS_REGISTER_SYSCTL], ]) ]) -dnl # -dnl # 2.6.23 API change -dnl # Old set_shrinker API replaced with register_shrinker -dnl # -AC_DEFUN([SPL_AC_SET_SHRINKER], [ - AC_MSG_CHECKING([whether set_shrinker() available]) - SPL_LINUX_TRY_COMPILE([ - #include - ],[ - return set_shrinker(DEFAULT_SEEKS, NULL); - ],[ - AC_MSG_RESULT([yes]) - AC_DEFINE(HAVE_SET_SHRINKER, 1, - [set_shrinker() available]) - ],[ - AC_MSG_RESULT([no]) - ]) -]) - -dnl # -dnl # 2.6.35 API change, -dnl # Add context to shrinker callback -dnl # -AC_DEFUN([SPL_AC_3ARGS_SHRINKER_CALLBACK], - [AC_MSG_CHECKING([whether shrinker callback wants 3 args]) +AC_DEFUN([SPL_AC_SHRINKER_CALLBACK],[ tmp_flags="$EXTRA_KCFLAGS" EXTRA_KCFLAGS="-Werror" + dnl # + dnl # 2.6.23 to 2.6.34 API change + dnl # ->shrink(int nr_to_scan, gfp_t gfp_mask) + dnl # + AC_MSG_CHECKING([whether old 2-argument shrinker exists]) SPL_LINUX_TRY_COMPILE([ #include - int shrinker_cb(struct shrinker *, int, unsigned int); + int shrinker_cb(int nr_to_scan, gfp_t gfp_mask); ],[ struct shrinker cache_shrinker = { .shrink = shrinker_cb, @@ -924,10 +904,86 @@ AC_DEFUN([SPL_AC_3ARGS_SHRINKER_CALLBACK], register_shrinker(&cache_shrinker); ],[ AC_MSG_RESULT(yes) - AC_DEFINE(HAVE_3ARGS_SHRINKER_CALLBACK, 1, - [shrinker callback wants 3 args]) + AC_DEFINE(HAVE_2ARGS_OLD_SHRINKER_CALLBACK, 1, + [old shrinker callback wants 2 args]) ],[ AC_MSG_RESULT(no) + dnl # + dnl # 2.6.35 - 2.6.39 API change + dnl # ->shrink(struct shrinker *, + dnl # int nr_to_scan, gfp_t gfp_mask) + dnl # + AC_MSG_CHECKING([whether old 3-argument shrinker exists]) + SPL_LINUX_TRY_COMPILE([ + #include + + int shrinker_cb(struct shrinker *, int nr_to_scan, + gfp_t gfp_mask); + ],[ + struct shrinker cache_shrinker = { + .shrink = shrinker_cb, + .seeks = DEFAULT_SEEKS, + }; + register_shrinker(&cache_shrinker); + ],[ + AC_MSG_RESULT(yes) + AC_DEFINE(HAVE_3ARGS_SHRINKER_CALLBACK, 1, + [old shrinker callback wants 3 args]) + ],[ + AC_MSG_RESULT(no) + dnl # + dnl # 3.0 - 3.11 API change + dnl # ->shrink(struct shrinker *, + dnl # struct shrink_control *sc) + dnl # + AC_MSG_CHECKING( + [whether new 2-argument shrinker exists]) + SPL_LINUX_TRY_COMPILE([ + #include + + int shrinker_cb(struct shrinker *, + struct shrink_control *sc); + ],[ + struct shrinker cache_shrinker = { + .shrink = shrinker_cb, + .seeks = DEFAULT_SEEKS, + }; + register_shrinker(&cache_shrinker); + ],[ + AC_MSG_RESULT(yes) + AC_DEFINE(HAVE_2ARGS_NEW_SHRINKER_CALLBACK, 1, + [new shrinker callback wants 2 args]) + ],[ + AC_MSG_RESULT(no) + dnl # + dnl # 3.12 API change, + dnl # ->shrink() is logically split in to + dnl # ->count_objects() and ->scan_objects() + dnl # + AC_MSG_CHECKING( + [whether ->count_objects callback exists]) + SPL_LINUX_TRY_COMPILE([ + #include + + unsigned long shrinker_cb( + struct shrinker *, + struct shrink_control *sc); + ],[ + struct shrinker cache_shrinker = { + .count_objects = shrinker_cb, + .scan_objects = shrinker_cb, + .seeks = DEFAULT_SEEKS, + }; + register_shrinker(&cache_shrinker); + ],[ + AC_MSG_RESULT(yes) + AC_DEFINE(HAVE_SPLIT_SHRINKER_CALLBACK, + 1, [->count_objects exists]) + ],[ + AC_MSG_ERROR(error) + ]) + ]) + ]) ]) EXTRA_KCFLAGS="$tmp_flags" ]) diff --git a/include/linux/mm_compat.h b/include/linux/mm_compat.h index cb1bef9a4..37c9b0875 100644 --- a/include/linux/mm_compat.h +++ b/include/linux/mm_compat.h @@ -148,107 +148,167 @@ extern shrink_icache_memory_t shrink_icache_memory_fn; #endif /* HAVE_SHRINK_ICACHE_MEMORY */ /* - * Linux 2.6. - 2.6. Shrinker API Compatibility. + * Due to frequent changes in the shrinker API the following + * compatibility wrappers should be used. They are as follows: + * + * SPL_SHRINKER_DECLARE is used to declare the shrinker which is + * passed to spl_register_shrinker()/spl_unregister_shrinker(). Use + * shrinker_name to set the shrinker variable name, shrinker_callback + * to set the callback function, and seek_cost to define the cost of + * reclaiming an object. + * + * SPL_SHRINKER_DECLARE(shrinker_name, shrinker_callback, seek_cost); + * + * SPL_SHRINKER_CALLBACK_FWD_DECLARE is used when a forward declaration + * of the shrinker callback function is required. Only the callback + * function needs to be passed. + * + * SPL_SHRINKER_CALLBACK_FWD_DECLARE(shrinker_callback); + * + * SPL_SHRINKER_CALLBACK_WRAPPER is used to declare the callback function + * which is registered with the shrinker. This function will call your + * custom shrinker which must use the following prototype. Notice the + * leading __'s, these must be appended to the callback_function name. + * + * int __shrinker_callback(struct shrinker *, struct shrink_control *) + * SPL_SHRINKER_CALLBACK_WRAPPER(shrinker_callback);a + * + * + * Example: + * + * SPL_SHRINKER_CALLBACK_FWD_DECLARE(my_shrinker_fn); + * SPL_SHRINKER_DECLARE(my_shrinker, my_shrinker_fn, 1); + * + * static int + * __my_shrinker_fn(struct shrinker *shrink, struct shrink_control *sc) + * { + * if (sc->nr_to_scan) { + * ...scan objects in the cache and reclaim them... + * } + * + * ...calculate number of objects in the cache... + * + * return (number of objects in the cache); + * } + * SPL_SHRINKER_CALLBACK_WRAPPER(my_shrinker_fn); */ -#ifdef HAVE_SET_SHRINKER -typedef struct spl_shrinker { - struct shrinker *shrinker; - shrinker_t fn; - int seeks; -} spl_shrinker_t; -static inline void -spl_register_shrinker(spl_shrinker_t *ss) -{ - ss->shrinker = set_shrinker(ss->seeks, ss->fn); +#define spl_register_shrinker(x) register_shrinker(x) +#define spl_unregister_shrinker(x) unregister_shrinker(x) + +/* + * Linux 2.6.23 - 2.6.34 Shrinker API Compatibility. + */ +#if defined(HAVE_2ARGS_OLD_SHRINKER_CALLBACK) +#define SPL_SHRINKER_DECLARE(s, x, y) \ +static struct shrinker s = { \ + .shrink = x, \ + .seeks = y \ } -static inline void -spl_unregister_shrinker(spl_shrinker_t *ss) -{ - remove_shrinker(ss->shrinker); +#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ +static int fn(int nr_to_scan, unsigned int gfp_mask) + +#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ +static int \ +fn(int nr_to_scan, unsigned int gfp_mask) \ +{ \ + struct shrink_control sc; \ + \ + sc.nr_to_scan = nr_to_scan; \ + sc.gfp_mask = gfp_mask; \ + \ + return (__ ## fn(NULL, &sc)); \ } -# define SPL_SHRINKER_DECLARE(s, x, y) \ - static spl_shrinker_t s = { \ - .shrinker = NULL, \ - .fn = x, \ - .seeks = y \ - } - -# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ - static int fn(int, unsigned int) -# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ -static int \ -fn(int nr_to_scan, unsigned int gfp_mask) \ -{ \ - struct shrink_control sc; \ - \ - sc.nr_to_scan = nr_to_scan; \ - sc.gfp_mask = gfp_mask; \ - \ - return __ ## fn(NULL, &sc); \ +/* + * Linux 2.6.35 to 2.6.39 Shrinker API Compatibility. + */ +#elif defined(HAVE_3ARGS_SHRINKER_CALLBACK) +#define SPL_SHRINKER_DECLARE(s, x, y) \ +static struct shrinker s = { \ + .shrink = x, \ + .seeks = y \ } +#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ +static int fn(struct shrinker *, int, unsigned int) + +#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ +static int \ +fn(struct shrinker *shrink, int nr_to_scan, unsigned int gfp_mask) \ +{ \ + struct shrink_control sc; \ + \ + sc.nr_to_scan = nr_to_scan; \ + sc.gfp_mask = gfp_mask; \ + \ + return (__ ## fn(shrink, &sc)); \ +} + +/* + * Linux 3.0 to 3.11 Shrinker API Compatibility. + */ +#elif defined(HAVE_2ARGS_NEW_SHRINKER_CALLBACK) +#define SPL_SHRINKER_DECLARE(s, x, y) \ +static struct shrinker s = { \ + .shrink = x, \ + .seeks = y \ +} + +#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ +static int fn(struct shrinker *, struct shrink_control *) + +#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ +static int \ +fn(struct shrinker *shrink, struct shrink_control *sc) \ +{ \ + return (__ ## fn(shrink, sc)); \ +} + +/* + * Linux 3.12 and later Shrinker API Compatibility. + */ +#elif defined(HAVE_SPLIT_SHRINKER_CALLBACK) +#define SPL_SHRINKER_DECLARE(s, x, y) \ +static struct shrinker s = { \ + .count_objects = x ## _count_objects, \ + .scan_objects = x ## _scan_objects, \ + .seeks = y \ +} + +#define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ +static unsigned long fn ## _count_objects(struct shrinker *, \ + struct shrink_control *); \ +static unsigned long fn ## _scan_objects(struct shrinker *, \ + struct shrink_control *) + +#define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ +static unsigned long \ +fn ## _count_objects(struct shrinker *shrink, struct shrink_control *sc)\ +{ \ + int __ret__; \ + \ + sc->nr_to_scan = 0; \ + __ret__ = __ ## fn(NULL, sc); \ + \ + /* Errors may not be returned and must be converted to zeros */ \ + return ((__ret__ < 0) ? 0 : __ret__); \ +} \ + \ +static unsigned long \ +fn ## _scan_objects(struct shrinker *shrink, struct shrink_control *sc) \ +{ \ + int __ret__; \ + \ + __ret__ = __ ## fn(NULL, sc); \ + return ((__ret__ < 0) ? SHRINK_STOP : __ret__); \ +} #else - -# define spl_register_shrinker(x) register_shrinker(x) -# define spl_unregister_shrinker(x) unregister_shrinker(x) -# define SPL_SHRINKER_DECLARE(s, x, y) \ - static struct shrinker s = { \ - .shrink = x, \ - .seeks = y \ - } - /* - * Linux 2.6. - 2.6. Shrinker API Compatibility. + * Linux 2.x to 2.6.22, or a newer shrinker API has been introduced. */ -# if defined(HAVE_SHRINK_CONTROL_STRUCT) -# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ - static int fn(struct shrinker *, struct shrink_control *) -# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ -static int \ -fn(struct shrinker *shrink, struct shrink_control *sc) { \ - return __ ## fn(shrink, sc); \ -} - -/* - * Linux 2.6. - 2.6. Shrinker API Compatibility. - */ -# elif defined(HAVE_3ARGS_SHRINKER_CALLBACK) -# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ - static int fn(struct shrinker *, int, unsigned int) -# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ -static int \ -fn(struct shrinker *shrink, int nr_to_scan, unsigned int gfp_mask) \ -{ \ - struct shrink_control sc; \ - \ - sc.nr_to_scan = nr_to_scan; \ - sc.gfp_mask = gfp_mask; \ - \ - return __ ## fn(shrink, &sc); \ -} - -/* - * Linux 2.6. - 2.6. Shrinker API Compatibility. - */ -# else -# define SPL_SHRINKER_CALLBACK_FWD_DECLARE(fn) \ - static int fn(int, unsigned int) -# define SPL_SHRINKER_CALLBACK_WRAPPER(fn) \ -static int \ -fn(int nr_to_scan, unsigned int gfp_mask) \ -{ \ - struct shrink_control sc; \ - \ - sc.nr_to_scan = nr_to_scan; \ - sc.gfp_mask = gfp_mask; \ - \ - return __ ## fn(NULL, &sc); \ -} - -# endif -#endif /* HAVE_SET_SHRINKER */ +#error "Unknown shrinker callback" +#endif #endif /* SPL_MM_COMPAT_H */