drivers/md/bcache/util.h - third_party/linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */

 #ifndef _BCACHE_UTIL_H
 #define _BCACHE_UTIL_H

 #include <linux/blkdev.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/sched/clock.h>
 #include <linux/llist.h>
 #include <linux/ratelimit.h>
 #include <linux/vmalloc.h>
 #include <linux/workqueue.h>

 #include "closure.h"

 #define PAGE_SECTORS		(PAGE_SIZE / 512)

 struct closure;

 #ifdef CONFIG_BCACHE_DEBUG

 #define EBUG_ON(cond)			BUG_ON(cond)
 #define atomic_dec_bug(v)	BUG_ON(atomic_dec_return(v) < 0)
 #define atomic_inc_bug(v, i)	BUG_ON(atomic_inc_return(v) <= i)

 #else /* DEBUG */

 #define EBUG_ON(cond)			do { if (cond); } while (0)
 #define atomic_dec_bug(v)	atomic_dec(v)
 #define atomic_inc_bug(v, i)	atomic_inc(v)

 #endif

 #define DECLARE_HEAP(type, name)					\
 	struct {							\
 		size_t size, used;					\
 		type *data;						\
 	} name

 #define init_heap(heap, _size, gfp)					\
 ({									\
 	size_t _bytes;							\
 	(heap)->used = 0;						\
 	(heap)->size = (_size);						\
 	_bytes = (heap)->size * sizeof(*(heap)->data);			\
 	(heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
 	(heap)->data;							\
 })

 #define free_heap(heap)							\
 do {									\
 	kvfree((heap)->data);						\
 	(heap)->data = NULL;						\
 } while (0)

 #define heap_swap(h, i, j)	swap((h)->data[i], (h)->data[j])

 #define heap_sift(h, i, cmp)						\
 do {									\
 	size_t _r, _j = i;						\
 									\
 	for (; _j * 2 + 1 < (h)->used; _j = _r) {			\
 		_r = _j * 2 + 1;					\
 		if (_r + 1 < (h)->used &&				\
 		    cmp((h)->data[_r], (h)->data[_r + 1]))		\
 			_r++;						\
 									\
 		if (cmp((h)->data[_r], (h)->data[_j]))			\
 			break;						\
 		heap_swap(h, _r, _j);					\
 	}								\
 } while (0)

 #define heap_sift_down(h, i, cmp)					\
 do {									\
 	while (i) {							\
 		size_t p = (i - 1) / 2;					\
 		if (cmp((h)->data[i], (h)->data[p]))			\
 			break;						\
 		heap_swap(h, i, p);					\
 		i = p;							\
 	}								\
 } while (0)

 #define heap_add(h, d, cmp)						\
 ({									\
 	bool _r = !heap_full(h);					\
 	if (_r) {							\
 		size_t _i = (h)->used++;				\
 		(h)->data[_i] = d;					\
 									\
 		heap_sift_down(h, _i, cmp);				\
 		heap_sift(h, _i, cmp);					\
 	}								\
 	_r;								\
 })

 #define heap_pop(h, d, cmp)						\
 ({									\
 	bool _r = (h)->used;						\
 	if (_r) {							\
 		(d) = (h)->data[0];					\
 		(h)->used--;						\
 		heap_swap(h, 0, (h)->used);				\
 		heap_sift(h, 0, cmp);					\
 	}								\
 	_r;								\
 })

 #define heap_peek(h)	((h)->used ? (h)->data[0] : NULL)

 #define heap_full(h)	((h)->used == (h)->size)

 #define heap_empty(h)	((h)->used == 0)

 #define DECLARE_FIFO(type, name)					\
 	struct {							\
 		size_t front, back, size, mask;				\
 		type *data;						\
 	} name

 #define fifo_for_each(c, fifo, iter)					\
 	for (iter = (fifo)->front;					\
 	     c = (fifo)->data[iter], iter != (fifo)->back;		\
 	     iter = (iter + 1) & (fifo)->mask)

 #define __init_fifo(fifo, gfp)						\
 ({									\
 	size_t _allocated_size, _bytes;					\
 	BUG_ON(!(fifo)->size);						\
 									\
 	_allocated_size = roundup_pow_of_two((fifo)->size + 1);		\
 	_bytes = _allocated_size * sizeof(*(fifo)->data);		\
 									\
 	(fifo)->mask = _allocated_size - 1;				\
 	(fifo)->front = (fifo)->back = 0;				\
 									\
 	(fifo)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL);		\
 	(fifo)->data;							\
 })

 #define init_fifo_exact(fifo, _size, gfp)				\
 ({									\
 	(fifo)->size = (_size);						\
 	__init_fifo(fifo, gfp);						\
 })

 #define init_fifo(fifo, _size, gfp)					\
 ({									\
 	(fifo)->size = (_size);						\
 	if ((fifo)->size > 4)						\
 		(fifo)->size = roundup_pow_of_two((fifo)->size) - 1;	\
 	__init_fifo(fifo, gfp);						\
 })

 #define free_fifo(fifo)							\
 do {									\
 	kvfree((fifo)->data);						\
 	(fifo)->data = NULL;						\
 } while (0)

 #define fifo_used(fifo)		(((fifo)->back - (fifo)->front) & (fifo)->mask)
 #define fifo_free(fifo)		((fifo)->size - fifo_used(fifo))

 #define fifo_empty(fifo)	(!fifo_used(fifo))
 #define fifo_full(fifo)		(!fifo_free(fifo))

 #define fifo_front(fifo)	((fifo)->data[(fifo)->front])
 #define fifo_back(fifo)							\
 	((fifo)->data[((fifo)->back - 1) & (fifo)->mask])

 #define fifo_idx(fifo, p)	(((p) - &fifo_front(fifo)) & (fifo)->mask)

 #define fifo_push_back(fifo, i)						\
 ({									\
 	bool _r = !fifo_full((fifo));					\
 	if (_r) {							\
 		(fifo)->data[(fifo)->back++] = (i);			\
 		(fifo)->back &= (fifo)->mask;				\
 	}								\
 	_r;								\
 })

 #define fifo_pop_front(fifo, i)						\
 ({									\
 	bool _r = !fifo_empty((fifo));					\
 	if (_r) {							\
 		(i) = (fifo)->data[(fifo)->front++];			\
 		(fifo)->front &= (fifo)->mask;				\
 	}								\
 	_r;								\
 })

 #define fifo_push_front(fifo, i)					\
 ({									\
 	bool _r = !fifo_full((fifo));					\
 	if (_r) {							\
 		--(fifo)->front;					\
 		(fifo)->front &= (fifo)->mask;				\
 		(fifo)->data[(fifo)->front] = (i);			\
 	}								\
 	_r;								\
 })

 #define fifo_pop_back(fifo, i)						\
 ({									\
 	bool _r = !fifo_empty((fifo));					\
 	if (_r) {							\
 		--(fifo)->back;						\
 		(fifo)->back &= (fifo)->mask;				\
 		(i) = (fifo)->data[(fifo)->back]			\
 	}								\
 	_r;								\
 })

 #define fifo_push(fifo, i)	fifo_push_back(fifo, (i))
 #define fifo_pop(fifo, i)	fifo_pop_front(fifo, (i))

 #define fifo_swap(l, r)							\
 do {									\
 	swap((l)->front, (r)->front);					\
 	swap((l)->back, (r)->back);					\
 	swap((l)->size, (r)->size);					\
 	swap((l)->mask, (r)->mask);					\
 	swap((l)->data, (r)->data);					\
 } while (0)

 #define fifo_move(dest, src)						\
 do {									\
 	typeof(*((dest)->data)) _t;					\
 	while (!fifo_full(dest) &&					\
 	       fifo_pop(src, _t))					\
 		fifo_push(dest, _t);					\
 } while (0)

 /*
  * Simple array based allocator - preallocates a number of elements and you can
  * never allocate more than that, also has no locking.
  *
  * Handy because if you know you only need a fixed number of elements you don't
  * have to worry about memory allocation failure, and sometimes a mempool isn't
  * what you want.
  *
  * We treat the free elements as entries in a singly linked list, and the
  * freelist as a stack - allocating and freeing push and pop off the freelist.
  */

 #define DECLARE_ARRAY_ALLOCATOR(type, name, size)			\
 	struct {							\
 		type	*freelist;					\
 		type	data[size];					\
 	} name

 #define array_alloc(array)						\
 ({									\
 	typeof((array)->freelist) _ret = (array)->freelist;		\
 									\
 	if (_ret)							\
 		(array)->freelist = *((typeof((array)->freelist) *) _ret);\
 									\
 	_ret;								\
 })

 #define array_free(array, ptr)						\
 do {									\
 	typeof((array)->freelist) _ptr = ptr;				\
 									\
 	*((typeof((array)->freelist) *) _ptr) = (array)->freelist;	\
 	(array)->freelist = _ptr;					\
 } while (0)

 #define array_allocator_init(array)					\
 do {									\
 	typeof((array)->freelist) _i;					\
 									\
 	BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *));	\
 	(array)->freelist = NULL;					\
 									\
 	for (_i = (array)->data;					\
 	     _i < (array)->data + ARRAY_SIZE((array)->data);		\
 	     _i++)							\
 		array_free(array, _i);					\
 } while (0)

 #define array_freelist_empty(array)	((array)->freelist == NULL)

 #define ANYSINT_MAX(t)							\
 	((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)

 int bch_strtoint_h(const char *, int *);
 int bch_strtouint_h(const char *, unsigned int *);
 int bch_strtoll_h(const char *, long long *);
 int bch_strtoull_h(const char *, unsigned long long *);

 static inline int bch_strtol_h(const char *cp, long *res)
 {
 #if BITS_PER_LONG == 32
 	return bch_strtoint_h(cp, (int *) res);
 #else
 	return bch_strtoll_h(cp, (long long *) res);
 #endif
 }

 static inline int bch_strtoul_h(const char *cp, long *res)
 {
 #if BITS_PER_LONG == 32
 	return bch_strtouint_h(cp, (unsigned int *) res);
 #else
 	return bch_strtoull_h(cp, (unsigned long long *) res);
 #endif
 }

 #define strtoi_h(cp, res)						\
 	(__builtin_types_compatible_p(typeof(*res), int)		\
 	? bch_strtoint_h(cp, (void *) res)				\
 	: __builtin_types_compatible_p(typeof(*res), long)		\
 	? bch_strtol_h(cp, (void *) res)				\
 	: __builtin_types_compatible_p(typeof(*res), long long)		\
 	? bch_strtoll_h(cp, (void *) res)				\
 	: __builtin_types_compatible_p(typeof(*res), unsigned int)	\
 	? bch_strtouint_h(cp, (void *) res)				\
 	: __builtin_types_compatible_p(typeof(*res), unsigned long)	\
 	? bch_strtoul_h(cp, (void *) res)				\
 	: __builtin_types_compatible_p(typeof(*res), unsigned long long)\
 	? bch_strtoull_h(cp, (void *) res) : -EINVAL)

 #define strtoul_safe(cp, var)						\
 ({									\
 	unsigned long _v;						\
 	int _r = kstrtoul(cp, 10, &_v);					\
 	if (!_r)							\
 		var = _v;						\
 	_r;								\
 })

 #define strtoul_safe_clamp(cp, var, min, max)				\
 ({									\
 	unsigned long _v;						\
 	int _r = kstrtoul(cp, 10, &_v);					\
 	if (!_r)							\
 		var = clamp_t(typeof(var), _v, min, max);		\
 	_r;								\
 })

 #define snprint(buf, size, var)						\
 	snprintf(buf, size,						\
 		__builtin_types_compatible_p(typeof(var), int)		\
 		     ? "%i\n" :						\
 		__builtin_types_compatible_p(typeof(var), unsigned)	\
 		     ? "%u\n" :						\
 		__builtin_types_compatible_p(typeof(var), long)		\
 		     ? "%li\n" :					\
 		__builtin_types_compatible_p(typeof(var), unsigned long)\
 		     ? "%lu\n" :					\
 		__builtin_types_compatible_p(typeof(var), int64_t)	\
 		     ? "%lli\n" :					\
 		__builtin_types_compatible_p(typeof(var), uint64_t)	\
 		     ? "%llu\n" :					\
 		__builtin_types_compatible_p(typeof(var), const char *)	\
 		     ? "%s\n" : "%i\n", var)

 ssize_t bch_hprint(char *buf, int64_t v);

 bool bch_is_zero(const char *p, size_t n);
 int bch_parse_uuid(const char *s, char *uuid);

 struct time_stats {
 	spinlock_t	lock;
 	/*
 	 * all fields are in nanoseconds, averages are ewmas stored left shifted
 	 * by 8
 	 */
 	uint64_t	max_duration;
 	uint64_t	average_duration;
 	uint64_t	average_frequency;
 	uint64_t	last;
 };

 void bch_time_stats_update(struct time_stats *stats, uint64_t time);

 static inline unsigned local_clock_us(void)
 {
 	return local_clock() >> 10;
 }

 #define NSEC_PER_ns			1L
 #define NSEC_PER_us			NSEC_PER_USEC
 #define NSEC_PER_ms			NSEC_PER_MSEC
 #define NSEC_PER_sec			NSEC_PER_SEC

 #define __print_time_stat(stats, name, stat, units)			\
 	sysfs_print(name ## _ ## stat ## _ ## units,			\
 		    div_u64((stats)->stat >> 8, NSEC_PER_ ## units))

 #define sysfs_print_time_stats(stats, name,				\
 			       frequency_units,				\
 			       duration_units)				\
 do {									\
 	__print_time_stat(stats, name,					\
 			  average_frequency,	frequency_units);	\
 	__print_time_stat(stats, name,					\
 			  average_duration,	duration_units);	\
 	sysfs_print(name ## _ ##max_duration ## _ ## duration_units,	\
 			div_u64((stats)->max_duration, NSEC_PER_ ## duration_units));\
 									\
 	sysfs_print(name ## _last_ ## frequency_units, (stats)->last	\
 		    ? div_s64(local_clock() - (stats)->last,		\
 			      NSEC_PER_ ## frequency_units)		\
 		    : -1LL);						\
 } while (0)

 #define sysfs_time_stats_attribute(name,				\
 				   frequency_units,			\
 				   duration_units)			\
 read_attribute(name ## _average_frequency_ ## frequency_units);		\
 read_attribute(name ## _average_duration_ ## duration_units);		\
 read_attribute(name ## _max_duration_ ## duration_units);		\
 read_attribute(name ## _last_ ## frequency_units)

 #define sysfs_time_stats_attribute_list(name,				\
 					frequency_units,		\
 					duration_units)			\
 &sysfs_ ## name ## _average_frequency_ ## frequency_units,		\
 &sysfs_ ## name ## _average_duration_ ## duration_units,		\
 &sysfs_ ## name ## _max_duration_ ## duration_units,			\
 &sysfs_ ## name ## _last_ ## frequency_units,

 #define ewma_add(ewma, val, weight, factor)				\
 ({									\
 	(ewma) *= (weight) - 1;						\
 	(ewma) += (val) << factor;					\
 	(ewma) /= (weight);						\
 	(ewma) >> factor;						\
 })

 struct bch_ratelimit {
 	/* Next time we want to do some work, in nanoseconds */
 	uint64_t		next;

 	/*
 	 * Rate at which we want to do work, in units per second
 	 * The units here correspond to the units passed to bch_next_delay()
 	 */
 	uint32_t		rate;
 };

 static inline void bch_ratelimit_reset(struct bch_ratelimit *d)
 {
 	d->next = local_clock();
 }

 uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done);

 #define __DIV_SAFE(n, d, zero)						\
 ({									\
 	typeof(n) _n = (n);						\
 	typeof(d) _d = (d);						\
 	_d ? _n / _d : zero;						\
 })

 #define DIV_SAFE(n, d)	__DIV_SAFE(n, d, 0)

 #define container_of_or_null(ptr, type, member)				\
 ({									\
 	typeof(ptr) _ptr = ptr;						\
 	_ptr ? container_of(_ptr, type, member) : NULL;			\
 })

 #define RB_INSERT(root, new, member, cmp)				\
 ({									\
 	__label__ dup;							\
 	struct rb_node **n = &(root)->rb_node, *parent = NULL;		\
 	typeof(new) this;						\
 	int res, ret = -1;						\
 									\
 	while (*n) {							\
 		parent = *n;						\
 		this = container_of(*n, typeof(*(new)), member);	\
 		res = cmp(new, this);					\
 		if (!res)						\
 			goto dup;					\
 		n = res < 0						\
 			? &(*n)->rb_left				\
 			: &(*n)->rb_right;				\
 	}								\
 									\
 	rb_link_node(&(new)->member, parent, n);			\
 	rb_insert_color(&(new)->member, root);				\
 	ret = 0;							\
 dup:									\
 	ret;								\
 })

 #define RB_SEARCH(root, search, member, cmp)				\
 ({									\
 	struct rb_node *n = (root)->rb_node;				\
 	typeof(&(search)) this, ret = NULL;				\
 	int res;							\
 									\
 	while (n) {							\
 		this = container_of(n, typeof(search), member);		\
 		res = cmp(&(search), this);				\
 		if (!res) {						\
 			ret = this;					\
 			break;						\
 		}							\
 		n = res < 0						\
 			? n->rb_left					\
 			: n->rb_right;					\
 	}								\
 	ret;								\
 })

 #define RB_GREATER(root, search, member, cmp)				\
 ({									\
 	struct rb_node *n = (root)->rb_node;				\
 	typeof(&(search)) this, ret = NULL;				\
 	int res;							\
 									\
 	while (n) {							\
 		this = container_of(n, typeof(search), member);		\
 		res = cmp(&(search), this);				\
 		if (res < 0) {						\
 			ret = this;					\
 			n = n->rb_left;					\
 		} else							\
 			n = n->rb_right;				\
 	}								\
 	ret;								\
 })

 #define RB_FIRST(root, type, member)					\
 	container_of_or_null(rb_first(root), type, member)

 #define RB_LAST(root, type, member)					\
 	container_of_or_null(rb_last(root), type, member)

 #define RB_NEXT(ptr, member)						\
 	container_of_or_null(rb_next(&(ptr)->member), typeof(*ptr), member)

 #define RB_PREV(ptr, member)						\
 	container_of_or_null(rb_prev(&(ptr)->member), typeof(*ptr), member)

 /* Does linear interpolation between powers of two */
 static inline unsigned fract_exp_two(unsigned x, unsigned fract_bits)
 {
 	unsigned fract = x & ~(~0 << fract_bits);

 	x >>= fract_bits;
 	x   = 1 << x;
 	x  += (x * fract) >> fract_bits;

 	return x;
 }

 void bch_bio_map(struct bio *bio, void *base);
 int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask);

 static inline sector_t bdev_sectors(struct block_device *bdev)
 {
 	return bdev->bd_inode->i_size >> 9;
 }

 uint64_t bch_crc64_update(uint64_t, const void *, size_t);
 uint64_t bch_crc64(const void *, size_t);

 #endif /* _BCACHE_UTIL_H */
	/* SPDX-License-Identifier: GPL-2.0 */

	#ifndef _BCACHE_UTIL_H
	#define _BCACHE_UTIL_H

	#include <linux/blkdev.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/sched/clock.h>
	#include <linux/llist.h>
	#include <linux/ratelimit.h>
	#include <linux/vmalloc.h>
	#include <linux/workqueue.h>

	#include "closure.h"

	#define PAGE_SECTORS (PAGE_SIZE / 512)

	struct closure;

	#ifdef CONFIG_BCACHE_DEBUG

	#define EBUG_ON(cond) BUG_ON(cond)
	#define atomic_dec_bug(v) BUG_ON(atomic_dec_return(v) < 0)
	#define atomic_inc_bug(v, i) BUG_ON(atomic_inc_return(v) <= i)

	#else /* DEBUG */

	#define EBUG_ON(cond) do { if (cond); } while (0)
	#define atomic_dec_bug(v) atomic_dec(v)
	#define atomic_inc_bug(v, i) atomic_inc(v)

	#endif

	#define DECLARE_HEAP(type, name) \
	struct { \
	size_t size, used; \
	type *data; \
	} name

	#define init_heap(heap, _size, gfp) \
	({ \
	size_t _bytes; \
	(heap)->used = 0; \
	(heap)->size = (_size); \
	_bytes = (heap)->size * sizeof(*(heap)->data); \
	(heap)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL); \
	(heap)->data; \
	})

	#define free_heap(heap) \
	do { \
	kvfree((heap)->data); \
	(heap)->data = NULL; \
	} while (0)

	#define heap_swap(h, i, j) swap((h)->data[i], (h)->data[j])

	#define heap_sift(h, i, cmp) \
	do { \
	size_t _r, _j = i; \
	\
	for (; _j * 2 + 1 < (h)->used; _j = _r) { \
	_r = _j * 2 + 1; \
	if (_r + 1 < (h)->used && \
	cmp((h)->data[_r], (h)->data[_r + 1])) \
	_r++; \
	\
	if (cmp((h)->data[_r], (h)->data[_j])) \
	break; \
	heap_swap(h, _r, _j); \
	} \
	} while (0)

	#define heap_sift_down(h, i, cmp) \
	do { \
	while (i) { \
	size_t p = (i - 1) / 2; \
	if (cmp((h)->data[i], (h)->data[p])) \
	break; \
	heap_swap(h, i, p); \
	i = p; \
	} \
	} while (0)

	#define heap_add(h, d, cmp) \
	({ \
	bool _r = !heap_full(h); \
	if (_r) { \
	size_t _i = (h)->used++; \
	(h)->data[_i] = d; \
	\
	heap_sift_down(h, _i, cmp); \
	heap_sift(h, _i, cmp); \
	} \
	_r; \
	})

	#define heap_pop(h, d, cmp) \
	({ \
	bool _r = (h)->used; \
	if (_r) { \
	(d) = (h)->data[0]; \
	(h)->used--; \
	heap_swap(h, 0, (h)->used); \
	heap_sift(h, 0, cmp); \
	} \
	_r; \
	})

	#define heap_peek(h) ((h)->used ? (h)->data[0] : NULL)

	#define heap_full(h) ((h)->used == (h)->size)

	#define heap_empty(h) ((h)->used == 0)

	#define DECLARE_FIFO(type, name) \
	struct { \
	size_t front, back, size, mask; \
	type *data; \
	} name

	#define fifo_for_each(c, fifo, iter) \
	for (iter = (fifo)->front; \
	c = (fifo)->data[iter], iter != (fifo)->back; \
	iter = (iter + 1) & (fifo)->mask)

	#define __init_fifo(fifo, gfp) \
	({ \
	size_t _allocated_size, _bytes; \
	BUG_ON(!(fifo)->size); \
	\
	_allocated_size = roundup_pow_of_two((fifo)->size + 1); \
	_bytes = _allocated_size * sizeof(*(fifo)->data); \
	\
	(fifo)->mask = _allocated_size - 1; \
	(fifo)->front = (fifo)->back = 0; \
	\
	(fifo)->data = kvmalloc(_bytes, (gfp) & GFP_KERNEL); \
	(fifo)->data; \
	})

	#define init_fifo_exact(fifo, _size, gfp) \
	({ \
	(fifo)->size = (_size); \
	__init_fifo(fifo, gfp); \
	})

	#define init_fifo(fifo, _size, gfp) \
	({ \
	(fifo)->size = (_size); \
	if ((fifo)->size > 4) \
	(fifo)->size = roundup_pow_of_two((fifo)->size) - 1; \
	__init_fifo(fifo, gfp); \
	})

	#define free_fifo(fifo) \
	do { \
	kvfree((fifo)->data); \
	(fifo)->data = NULL; \
	} while (0)

	#define fifo_used(fifo) (((fifo)->back - (fifo)->front) & (fifo)->mask)
	#define fifo_free(fifo) ((fifo)->size - fifo_used(fifo))

	#define fifo_empty(fifo) (!fifo_used(fifo))
	#define fifo_full(fifo) (!fifo_free(fifo))

	#define fifo_front(fifo) ((fifo)->data[(fifo)->front])
	#define fifo_back(fifo) \
	((fifo)->data[((fifo)->back - 1) & (fifo)->mask])

	#define fifo_idx(fifo, p) (((p) - &fifo_front(fifo)) & (fifo)->mask)

	#define fifo_push_back(fifo, i) \
	({ \
	bool _r = !fifo_full((fifo)); \
	if (_r) { \
	(fifo)->data[(fifo)->back++] = (i); \
	(fifo)->back &= (fifo)->mask; \
	} \
	_r; \
	})

	#define fifo_pop_front(fifo, i) \
	({ \
	bool _r = !fifo_empty((fifo)); \
	if (_r) { \
	(i) = (fifo)->data[(fifo)->front++]; \
	(fifo)->front &= (fifo)->mask; \
	} \
	_r; \
	})

	#define fifo_push_front(fifo, i) \
	({ \
	bool _r = !fifo_full((fifo)); \
	if (_r) { \
	--(fifo)->front; \
	(fifo)->front &= (fifo)->mask; \
	(fifo)->data[(fifo)->front] = (i); \
	} \
	_r; \
	})

	#define fifo_pop_back(fifo, i) \
	({ \
	bool _r = !fifo_empty((fifo)); \
	if (_r) { \
	--(fifo)->back; \
	(fifo)->back &= (fifo)->mask; \
	(i) = (fifo)->data[(fifo)->back] \
	} \
	_r; \
	})

	#define fifo_push(fifo, i) fifo_push_back(fifo, (i))
	#define fifo_pop(fifo, i) fifo_pop_front(fifo, (i))

	#define fifo_swap(l, r) \
	do { \
	swap((l)->front, (r)->front); \
	swap((l)->back, (r)->back); \
	swap((l)->size, (r)->size); \
	swap((l)->mask, (r)->mask); \
	swap((l)->data, (r)->data); \
	} while (0)

	#define fifo_move(dest, src) \
	do { \
	typeof(*((dest)->data)) _t; \
	while (!fifo_full(dest) && \
	fifo_pop(src, _t)) \
	fifo_push(dest, _t); \
	} while (0)

	/*
	* Simple array based allocator - preallocates a number of elements and you can
	* never allocate more than that, also has no locking.
	*
	* Handy because if you know you only need a fixed number of elements you don't
	* have to worry about memory allocation failure, and sometimes a mempool isn't
	* what you want.
	*
	* We treat the free elements as entries in a singly linked list, and the
	* freelist as a stack - allocating and freeing push and pop off the freelist.
	*/

	#define DECLARE_ARRAY_ALLOCATOR(type, name, size) \
	struct { \
	type *freelist; \
	type data[size]; \
	} name

	#define array_alloc(array) \
	({ \
	typeof((array)->freelist) _ret = (array)->freelist; \
	\
	if (_ret) \
	(array)->freelist = ((typeof((array)->freelist) ) _ret);\
	\
	_ret; \
	})

	#define array_free(array, ptr) \
	do { \
	typeof((array)->freelist) _ptr = ptr; \
	\
	((typeof((array)->freelist) ) _ptr) = (array)->freelist; \
	(array)->freelist = _ptr; \
	} while (0)

	#define array_allocator_init(array) \
	do { \
	typeof((array)->freelist) _i; \
	\
	BUILD_BUG_ON(sizeof((array)->data[0]) < sizeof(void *)); \
	(array)->freelist = NULL; \
	\
	for (_i = (array)->data; \
	_i < (array)->data + ARRAY_SIZE((array)->data); \
	_i++) \
	array_free(array, _i); \
	} while (0)

	#define array_freelist_empty(array) ((array)->freelist == NULL)

	#define ANYSINT_MAX(t) \
	((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)

	int bch_strtoint_h(const char , int );
	int bch_strtouint_h(const char , unsigned int );
	int bch_strtoll_h(const char , long long );
	int bch_strtoull_h(const char , unsigned long long );

	static inline int bch_strtol_h(const char cp, long res)
	{
	#if BITS_PER_LONG == 32
	return bch_strtoint_h(cp, (int *) res);
	#else
	return bch_strtoll_h(cp, (long long *) res);
	#endif
	}

	static inline int bch_strtoul_h(const char cp, long res)
	{
	#if BITS_PER_LONG == 32
	return bch_strtouint_h(cp, (unsigned int *) res);
	#else
	return bch_strtoull_h(cp, (unsigned long long *) res);
	#endif
	}

	#define strtoi_h(cp, res) \
	(__builtin_types_compatible_p(typeof(*res), int) \
	? bch_strtoint_h(cp, (void *) res) \
	: __builtin_types_compatible_p(typeof(*res), long) \
	? bch_strtol_h(cp, (void *) res) \
	: __builtin_types_compatible_p(typeof(*res), long long) \
	? bch_strtoll_h(cp, (void *) res) \
	: __builtin_types_compatible_p(typeof(*res), unsigned int) \
	? bch_strtouint_h(cp, (void *) res) \
	: __builtin_types_compatible_p(typeof(*res), unsigned long) \
	? bch_strtoul_h(cp, (void *) res) \
	: __builtin_types_compatible_p(typeof(*res), unsigned long long)\
	? bch_strtoull_h(cp, (void *) res) : -EINVAL)

	#define strtoul_safe(cp, var) \
	({ \
	unsigned long _v; \
	int _r = kstrtoul(cp, 10, &_v); \
	if (!_r) \
	var = _v; \
	_r; \
	})

	#define strtoul_safe_clamp(cp, var, min, max) \
	({ \
	unsigned long _v; \
	int _r = kstrtoul(cp, 10, &_v); \
	if (!_r) \
	var = clamp_t(typeof(var), _v, min, max); \
	_r; \
	})

	#define snprint(buf, size, var) \
	snprintf(buf, size, \
	__builtin_types_compatible_p(typeof(var), int) \
	? "%i\n" : \
	__builtin_types_compatible_p(typeof(var), unsigned) \
	? "%u\n" : \
	__builtin_types_compatible_p(typeof(var), long) \
	? "%li\n" : \
	__builtin_types_compatible_p(typeof(var), unsigned long)\
	? "%lu\n" : \
	__builtin_types_compatible_p(typeof(var), int64_t) \
	? "%lli\n" : \
	__builtin_types_compatible_p(typeof(var), uint64_t) \
	? "%llu\n" : \
	__builtin_types_compatible_p(typeof(var), const char *) \
	? "%s\n" : "%i\n", var)

	ssize_t bch_hprint(char *buf, int64_t v);

	bool bch_is_zero(const char *p, size_t n);
	int bch_parse_uuid(const char s, char uuid);

	struct time_stats {
	spinlock_t lock;
	/*
	* all fields are in nanoseconds, averages are ewmas stored left shifted
	* by 8
	*/
	uint64_t max_duration;
	uint64_t average_duration;
	uint64_t average_frequency;
	uint64_t last;
	};

	void bch_time_stats_update(struct time_stats *stats, uint64_t time);

	static inline unsigned local_clock_us(void)
	{
	return local_clock() >> 10;
	}

	#define NSEC_PER_ns 1L
	#define NSEC_PER_us NSEC_PER_USEC
	#define NSEC_PER_ms NSEC_PER_MSEC
	#define NSEC_PER_sec NSEC_PER_SEC

	#define __print_time_stat(stats, name, stat, units) \
	sysfs_print(name ## _ ## stat ## _ ## units, \
	div_u64((stats)->stat >> 8, NSEC_PER_ ## units))

	#define sysfs_print_time_stats(stats, name, \
	frequency_units, \
	duration_units) \
	do { \
	__print_time_stat(stats, name, \
	average_frequency, frequency_units); \
	__print_time_stat(stats, name, \
	average_duration, duration_units); \
	sysfs_print(name ## _ ##max_duration ## _ ## duration_units, \
	div_u64((stats)->max_duration, NSEC_PER_ ## duration_units));\
	\
	sysfs_print(name ## _last_ ## frequency_units, (stats)->last \
	? div_s64(local_clock() - (stats)->last, \
	NSEC_PER_ ## frequency_units) \
	: -1LL); \
	} while (0)

	#define sysfs_time_stats_attribute(name, \
	frequency_units, \
	duration_units) \
	read_attribute(name ## _average_frequency_ ## frequency_units); \
	read_attribute(name ## _average_duration_ ## duration_units); \
	read_attribute(name ## _max_duration_ ## duration_units); \
	read_attribute(name ## _last_ ## frequency_units)

	#define sysfs_time_stats_attribute_list(name, \
	frequency_units, \
	duration_units) \
	&sysfs_ ## name ## _average_frequency_ ## frequency_units, \
	&sysfs_ ## name ## _average_duration_ ## duration_units, \
	&sysfs_ ## name ## _max_duration_ ## duration_units, \
	&sysfs_ ## name ## _last_ ## frequency_units,

	#define ewma_add(ewma, val, weight, factor) \
	({ \
	(ewma) *= (weight) - 1; \
	(ewma) += (val) << factor; \
	(ewma) /= (weight); \
	(ewma) >> factor; \
	})

	struct bch_ratelimit {
	/* Next time we want to do some work, in nanoseconds */
	uint64_t next;

	/*
	* Rate at which we want to do work, in units per second
	* The units here correspond to the units passed to bch_next_delay()
	*/
	uint32_t rate;
	};

	static inline void bch_ratelimit_reset(struct bch_ratelimit *d)
	{
	d->next = local_clock();
	}

	uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done);

	#define __DIV_SAFE(n, d, zero) \
	({ \
	typeof(n) _n = (n); \
	typeof(d) _d = (d); \
	_d ? _n / _d : zero; \
	})

	#define DIV_SAFE(n, d) __DIV_SAFE(n, d, 0)

	#define container_of_or_null(ptr, type, member) \
	({ \
	typeof(ptr) _ptr = ptr; \
	_ptr ? container_of(_ptr, type, member) : NULL; \
	})

	#define RB_INSERT(root, new, member, cmp) \
	({ \
	__label__ dup; \
	struct rb_node *n = &(root)->rb_node, parent = NULL; \
	typeof(new) this; \
	int res, ret = -1; \
	\
	while (*n) { \
	parent = *n; \
	this = container_of(n, typeof((new)), member); \
	res = cmp(new, this); \
	if (!res) \
	goto dup; \
	n = res < 0 \
	? &(*n)->rb_left \
	: &(*n)->rb_right; \
	} \
	\
	rb_link_node(&(new)->member, parent, n); \
	rb_insert_color(&(new)->member, root); \
	ret = 0; \
	dup: \
	ret; \
	})

	#define RB_SEARCH(root, search, member, cmp) \
	({ \
	struct rb_node *n = (root)->rb_node; \
	typeof(&(search)) this, ret = NULL; \
	int res; \
	\
	while (n) { \
	this = container_of(n, typeof(search), member); \
	res = cmp(&(search), this); \
	if (!res) { \
	ret = this; \
	break; \
	} \
	n = res < 0 \
	? n->rb_left \
	: n->rb_right; \
	} \
	ret; \
	})

	#define RB_GREATER(root, search, member, cmp) \
	({ \
	struct rb_node *n = (root)->rb_node; \
	typeof(&(search)) this, ret = NULL; \
	int res; \
	\
	while (n) { \
	this = container_of(n, typeof(search), member); \
	res = cmp(&(search), this); \
	if (res < 0) { \
	ret = this; \
	n = n->rb_left; \
	} else \
	n = n->rb_right; \
	} \
	ret; \
	})

	#define RB_FIRST(root, type, member) \
	container_of_or_null(rb_first(root), type, member)

	#define RB_LAST(root, type, member) \
	container_of_or_null(rb_last(root), type, member)

	#define RB_NEXT(ptr, member) \
	container_of_or_null(rb_next(&(ptr)->member), typeof(*ptr), member)

	#define RB_PREV(ptr, member) \
	container_of_or_null(rb_prev(&(ptr)->member), typeof(*ptr), member)

	/* Does linear interpolation between powers of two */
	static inline unsigned fract_exp_two(unsigned x, unsigned fract_bits)
	{
	unsigned fract = x & ~(~0 << fract_bits);

	x >>= fract_bits;
	x = 1 << x;
	x += (x * fract) >> fract_bits;

	return x;
	}

	void bch_bio_map(struct bio bio, void base);
	int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask);

	static inline sector_t bdev_sectors(struct block_device *bdev)
	{
	return bdev->bd_inode->i_size >> 9;
	}

	uint64_t bch_crc64_update(uint64_t, const void *, size_t);
	uint64_t bch_crc64(const void *, size_t);

	#endif /* _BCACHE_UTIL_H */