Linux Audio

Check our new training course

Loading...
Note: File does not exist in v4.10.11.
  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _BCACHEFS_UTIL_H
  3#define _BCACHEFS_UTIL_H
  4
  5#include <linux/bio.h>
  6#include <linux/blkdev.h>
  7#include <linux/closure.h>
  8#include <linux/errno.h>
  9#include <linux/freezer.h>
 10#include <linux/kernel.h>
 11#include <linux/min_heap.h>
 12#include <linux/sched/clock.h>
 13#include <linux/llist.h>
 14#include <linux/log2.h>
 15#include <linux/percpu.h>
 16#include <linux/preempt.h>
 17#include <linux/ratelimit.h>
 18#include <linux/slab.h>
 19#include <linux/vmalloc.h>
 20#include <linux/workqueue.h>
 21
 22#include "mean_and_variance.h"
 23
 24#include "darray.h"
 25#include "time_stats.h"
 26
 27struct closure;
 28
 29#ifdef CONFIG_BCACHEFS_DEBUG
 30#define EBUG_ON(cond)		BUG_ON(cond)
 31#else
 32#define EBUG_ON(cond)
 33#endif
 34
 35#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 36#define CPU_BIG_ENDIAN		0
 37#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 38#define CPU_BIG_ENDIAN		1
 39#endif
 40
 41/* type hackery */
 42
 43#define type_is_exact(_val, _type)					\
 44	__builtin_types_compatible_p(typeof(_val), _type)
 45
 46#define type_is(_val, _type)						\
 47	(__builtin_types_compatible_p(typeof(_val), _type) ||		\
 48	 __builtin_types_compatible_p(typeof(_val), const _type))
 49
 50/* Userspace doesn't align allocations as nicely as the kernel allocators: */
 51static inline size_t buf_pages(void *p, size_t len)
 52{
 53	return DIV_ROUND_UP(len +
 54			    ((unsigned long) p & (PAGE_SIZE - 1)),
 55			    PAGE_SIZE);
 56}
 57
 58#define init_heap(heap, _size, gfp)					\
 59({									\
 60	(heap)->nr = 0;						\
 61	(heap)->size = (_size);						\
 62	(heap)->data = kvmalloc((heap)->size * sizeof((heap)->data[0]),\
 63				 (gfp));				\
 64})
 65
 66#define free_heap(heap)							\
 67do {									\
 68	kvfree((heap)->data);						\
 69	(heap)->data = NULL;						\
 70} while (0)
 71
 72#define ANYSINT_MAX(t)							\
 73	((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)
 74
 75#include "printbuf.h"
 76
 77#define prt_vprintf(_out, ...)		bch2_prt_vprintf(_out, __VA_ARGS__)
 78#define prt_printf(_out, ...)		bch2_prt_printf(_out, __VA_ARGS__)
 79#define printbuf_str(_buf)		bch2_printbuf_str(_buf)
 80#define printbuf_exit(_buf)		bch2_printbuf_exit(_buf)
 81
 82#define printbuf_tabstops_reset(_buf)	bch2_printbuf_tabstops_reset(_buf)
 83#define printbuf_tabstop_pop(_buf)	bch2_printbuf_tabstop_pop(_buf)
 84#define printbuf_tabstop_push(_buf, _n)	bch2_printbuf_tabstop_push(_buf, _n)
 85
 86#define printbuf_indent_add(_out, _n)	bch2_printbuf_indent_add(_out, _n)
 87#define printbuf_indent_sub(_out, _n)	bch2_printbuf_indent_sub(_out, _n)
 88
 89#define prt_newline(_out)		bch2_prt_newline(_out)
 90#define prt_tab(_out)			bch2_prt_tab(_out)
 91#define prt_tab_rjust(_out)		bch2_prt_tab_rjust(_out)
 92
 93#define prt_bytes_indented(...)		bch2_prt_bytes_indented(__VA_ARGS__)
 94#define prt_u64(_out, _v)		prt_printf(_out, "%llu", (u64) (_v))
 95#define prt_human_readable_u64(...)	bch2_prt_human_readable_u64(__VA_ARGS__)
 96#define prt_human_readable_s64(...)	bch2_prt_human_readable_s64(__VA_ARGS__)
 97#define prt_units_u64(...)		bch2_prt_units_u64(__VA_ARGS__)
 98#define prt_units_s64(...)		bch2_prt_units_s64(__VA_ARGS__)
 99#define prt_string_option(...)		bch2_prt_string_option(__VA_ARGS__)
100#define prt_bitflags(...)		bch2_prt_bitflags(__VA_ARGS__)
101#define prt_bitflags_vector(...)	bch2_prt_bitflags_vector(__VA_ARGS__)
102
103void bch2_pr_time_units(struct printbuf *, u64);
104void bch2_prt_datetime(struct printbuf *, time64_t);
105
106#ifdef __KERNEL__
107static inline void uuid_unparse_lower(u8 *uuid, char *out)
108{
109	sprintf(out, "%pUb", uuid);
110}
111#else
112#include <uuid/uuid.h>
113#endif
114
115static inline void pr_uuid(struct printbuf *out, u8 *uuid)
116{
117	char uuid_str[40];
118
119	uuid_unparse_lower(uuid, uuid_str);
120	prt_printf(out, "%s", uuid_str);
121}
122
123int bch2_strtoint_h(const char *, int *);
124int bch2_strtouint_h(const char *, unsigned int *);
125int bch2_strtoll_h(const char *, long long *);
126int bch2_strtoull_h(const char *, unsigned long long *);
127int bch2_strtou64_h(const char *, u64 *);
128
129static inline int bch2_strtol_h(const char *cp, long *res)
130{
131#if BITS_PER_LONG == 32
132	return bch2_strtoint_h(cp, (int *) res);
133#else
134	return bch2_strtoll_h(cp, (long long *) res);
135#endif
136}
137
138static inline int bch2_strtoul_h(const char *cp, long *res)
139{
140#if BITS_PER_LONG == 32
141	return bch2_strtouint_h(cp, (unsigned int *) res);
142#else
143	return bch2_strtoull_h(cp, (unsigned long long *) res);
144#endif
145}
146
147#define strtoi_h(cp, res)						\
148	( type_is(*res, int)		? bch2_strtoint_h(cp, (void *) res)\
149	: type_is(*res, long)		? bch2_strtol_h(cp, (void *) res)\
150	: type_is(*res, long long)	? bch2_strtoll_h(cp, (void *) res)\
151	: type_is(*res, unsigned)	? bch2_strtouint_h(cp, (void *) res)\
152	: type_is(*res, unsigned long)	? bch2_strtoul_h(cp, (void *) res)\
153	: type_is(*res, unsigned long long) ? bch2_strtoull_h(cp, (void *) res)\
154	: -EINVAL)
155
156#define strtoul_safe(cp, var)						\
157({									\
158	unsigned long _v;						\
159	int _r = kstrtoul(cp, 10, &_v);					\
160	if (!_r)							\
161		var = _v;						\
162	_r;								\
163})
164
165#define strtoul_safe_clamp(cp, var, min, max)				\
166({									\
167	unsigned long _v;						\
168	int _r = kstrtoul(cp, 10, &_v);					\
169	if (!_r)							\
170		var = clamp_t(typeof(var), _v, min, max);		\
171	_r;								\
172})
173
174#define strtoul_safe_restrict(cp, var, min, max)			\
175({									\
176	unsigned long _v;						\
177	int _r = kstrtoul(cp, 10, &_v);					\
178	if (!_r && _v >= min && _v <= max)				\
179		var = _v;						\
180	else								\
181		_r = -EINVAL;						\
182	_r;								\
183})
184
185#define snprint(out, var)						\
186	prt_printf(out,							\
187		   type_is(var, int)		? "%i\n"		\
188		 : type_is(var, unsigned)	? "%u\n"		\
189		 : type_is(var, long)		? "%li\n"		\
190		 : type_is(var, unsigned long)	? "%lu\n"		\
191		 : type_is(var, s64)		? "%lli\n"		\
192		 : type_is(var, u64)		? "%llu\n"		\
193		 : type_is(var, char *)		? "%s\n"		\
194		 : "%i\n", var)
195
196bool bch2_is_zero(const void *, size_t);
197
198u64 bch2_read_flag_list(const char *, const char * const[]);
199
200void bch2_prt_u64_base2_nbits(struct printbuf *, u64, unsigned);
201void bch2_prt_u64_base2(struct printbuf *, u64);
202
203void bch2_print_string_as_lines(const char *prefix, const char *lines);
204void bch2_print_string_as_lines_nonblocking(const char *prefix, const char *lines);
205
206typedef DARRAY(unsigned long) bch_stacktrace;
207int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *, unsigned, gfp_t);
208void bch2_prt_backtrace(struct printbuf *, bch_stacktrace *);
209int bch2_prt_task_backtrace(struct printbuf *, struct task_struct *, unsigned, gfp_t);
210
211static inline void prt_bdevname(struct printbuf *out, struct block_device *bdev)
212{
213#ifdef __KERNEL__
214	prt_printf(out, "%pg", bdev);
215#else
216	prt_str(out, bdev->name);
217#endif
218}
219
220void bch2_time_stats_to_text(struct printbuf *, struct bch2_time_stats *);
221
222#define ewma_add(ewma, val, weight)					\
223({									\
224	typeof(ewma) _ewma = (ewma);					\
225	typeof(weight) _weight = (weight);				\
226									\
227	(((_ewma << _weight) - _ewma) + (val)) >> _weight;		\
228})
229
230struct bch_ratelimit {
231	/* Next time we want to do some work, in nanoseconds */
232	u64			next;
233
234	/*
235	 * Rate at which we want to do work, in units per nanosecond
236	 * The units here correspond to the units passed to
237	 * bch2_ratelimit_increment()
238	 */
239	unsigned		rate;
240};
241
242static inline void bch2_ratelimit_reset(struct bch_ratelimit *d)
243{
244	d->next = local_clock();
245}
246
247u64 bch2_ratelimit_delay(struct bch_ratelimit *);
248void bch2_ratelimit_increment(struct bch_ratelimit *, u64);
249
250struct bch_pd_controller {
251	struct bch_ratelimit	rate;
252	unsigned long		last_update;
253
254	s64			last_actual;
255	s64			smoothed_derivative;
256
257	unsigned		p_term_inverse;
258	unsigned		d_smooth;
259	unsigned		d_term;
260
261	/* for exporting to sysfs (no effect on behavior) */
262	s64			last_derivative;
263	s64			last_proportional;
264	s64			last_change;
265	s64			last_target;
266
267	/*
268	 * If true, the rate will not increase if bch2_ratelimit_delay()
269	 * is not being called often enough.
270	 */
271	bool			backpressure;
272};
273
274void bch2_pd_controller_update(struct bch_pd_controller *, s64, s64, int);
275void bch2_pd_controller_init(struct bch_pd_controller *);
276void bch2_pd_controller_debug_to_text(struct printbuf *, struct bch_pd_controller *);
277
278#define sysfs_pd_controller_attribute(name)				\
279	rw_attribute(name##_rate);					\
280	rw_attribute(name##_rate_bytes);				\
281	rw_attribute(name##_rate_d_term);				\
282	rw_attribute(name##_rate_p_term_inverse);			\
283	read_attribute(name##_rate_debug)
284
285#define sysfs_pd_controller_files(name)					\
286	&sysfs_##name##_rate,						\
287	&sysfs_##name##_rate_bytes,					\
288	&sysfs_##name##_rate_d_term,					\
289	&sysfs_##name##_rate_p_term_inverse,				\
290	&sysfs_##name##_rate_debug
291
292#define sysfs_pd_controller_show(name, var)				\
293do {									\
294	sysfs_hprint(name##_rate,		(var)->rate.rate);	\
295	sysfs_print(name##_rate_bytes,		(var)->rate.rate);	\
296	sysfs_print(name##_rate_d_term,		(var)->d_term);		\
297	sysfs_print(name##_rate_p_term_inverse,	(var)->p_term_inverse);	\
298									\
299	if (attr == &sysfs_##name##_rate_debug)				\
300		bch2_pd_controller_debug_to_text(out, var);		\
301} while (0)
302
303#define sysfs_pd_controller_store(name, var)				\
304do {									\
305	sysfs_strtoul_clamp(name##_rate,				\
306			    (var)->rate.rate, 1, UINT_MAX);		\
307	sysfs_strtoul_clamp(name##_rate_bytes,				\
308			    (var)->rate.rate, 1, UINT_MAX);		\
309	sysfs_strtoul(name##_rate_d_term,	(var)->d_term);		\
310	sysfs_strtoul_clamp(name##_rate_p_term_inverse,			\
311			    (var)->p_term_inverse, 1, INT_MAX);		\
312} while (0)
313
314#define container_of_or_null(ptr, type, member)				\
315({									\
316	typeof(ptr) _ptr = ptr;						\
317	_ptr ? container_of(_ptr, type, member) : NULL;			\
318})
319
320/* Does linear interpolation between powers of two */
321static inline unsigned fract_exp_two(unsigned x, unsigned fract_bits)
322{
323	unsigned fract = x & ~(~0 << fract_bits);
324
325	x >>= fract_bits;
326	x   = 1 << x;
327	x  += (x * fract) >> fract_bits;
328
329	return x;
330}
331
332void bch2_bio_map(struct bio *bio, void *base, size_t);
333int bch2_bio_alloc_pages(struct bio *, size_t, gfp_t);
334
335#define closure_bio_submit(bio, cl)					\
336do {									\
337	closure_get(cl);						\
338	submit_bio(bio);						\
339} while (0)
340
341#define kthread_wait(cond)						\
342({									\
343	int _ret = 0;							\
344									\
345	while (1) {							\
346		set_current_state(TASK_INTERRUPTIBLE);			\
347		if (kthread_should_stop()) {				\
348			_ret = -1;					\
349			break;						\
350		}							\
351									\
352		if (cond)						\
353			break;						\
354									\
355		schedule();						\
356	}								\
357	set_current_state(TASK_RUNNING);				\
358	_ret;								\
359})
360
361#define kthread_wait_freezable(cond)					\
362({									\
363	int _ret = 0;							\
364	while (1) {							\
365		set_current_state(TASK_INTERRUPTIBLE);			\
366		if (kthread_should_stop()) {				\
367			_ret = -1;					\
368			break;						\
369		}							\
370									\
371		if (cond)						\
372			break;						\
373									\
374		schedule();						\
375		try_to_freeze();					\
376	}								\
377	set_current_state(TASK_RUNNING);				\
378	_ret;								\
379})
380
381size_t bch2_rand_range(size_t);
382
383void memcpy_to_bio(struct bio *, struct bvec_iter, const void *);
384void memcpy_from_bio(void *, struct bio *, struct bvec_iter);
385
386static inline void memcpy_u64s_small(void *dst, const void *src,
387				     unsigned u64s)
388{
389	u64 *d = dst;
390	const u64 *s = src;
391
392	while (u64s--)
393		*d++ = *s++;
394}
395
396static inline void __memcpy_u64s(void *dst, const void *src,
397				 unsigned u64s)
398{
399#ifdef CONFIG_X86_64
400	long d0, d1, d2;
401
402	asm volatile("rep ; movsq"
403		     : "=&c" (d0), "=&D" (d1), "=&S" (d2)
404		     : "0" (u64s), "1" (dst), "2" (src)
405		     : "memory");
406#else
407	u64 *d = dst;
408	const u64 *s = src;
409
410	while (u64s--)
411		*d++ = *s++;
412#endif
413}
414
415static inline void memcpy_u64s(void *dst, const void *src,
416			       unsigned u64s)
417{
418	EBUG_ON(!(dst >= src + u64s * sizeof(u64) ||
419		 dst + u64s * sizeof(u64) <= src));
420
421	__memcpy_u64s(dst, src, u64s);
422}
423
424static inline void __memmove_u64s_down(void *dst, const void *src,
425				       unsigned u64s)
426{
427	__memcpy_u64s(dst, src, u64s);
428}
429
430static inline void memmove_u64s_down(void *dst, const void *src,
431				     unsigned u64s)
432{
433	EBUG_ON(dst > src);
434
435	__memmove_u64s_down(dst, src, u64s);
436}
437
438static inline void __memmove_u64s_down_small(void *dst, const void *src,
439				       unsigned u64s)
440{
441	memcpy_u64s_small(dst, src, u64s);
442}
443
444static inline void memmove_u64s_down_small(void *dst, const void *src,
445				     unsigned u64s)
446{
447	EBUG_ON(dst > src);
448
449	__memmove_u64s_down_small(dst, src, u64s);
450}
451
452static inline void __memmove_u64s_up_small(void *_dst, const void *_src,
453					   unsigned u64s)
454{
455	u64 *dst = (u64 *) _dst + u64s;
456	u64 *src = (u64 *) _src + u64s;
457
458	while (u64s--)
459		*--dst = *--src;
460}
461
462static inline void memmove_u64s_up_small(void *dst, const void *src,
463					 unsigned u64s)
464{
465	EBUG_ON(dst < src);
466
467	__memmove_u64s_up_small(dst, src, u64s);
468}
469
470static inline void __memmove_u64s_up(void *_dst, const void *_src,
471				     unsigned u64s)
472{
473	u64 *dst = (u64 *) _dst + u64s - 1;
474	u64 *src = (u64 *) _src + u64s - 1;
475
476#ifdef CONFIG_X86_64
477	long d0, d1, d2;
478
479	asm volatile("std ;\n"
480		     "rep ; movsq\n"
481		     "cld ;\n"
482		     : "=&c" (d0), "=&D" (d1), "=&S" (d2)
483		     : "0" (u64s), "1" (dst), "2" (src)
484		     : "memory");
485#else
486	while (u64s--)
487		*dst-- = *src--;
488#endif
489}
490
491static inline void memmove_u64s_up(void *dst, const void *src,
492				   unsigned u64s)
493{
494	EBUG_ON(dst < src);
495
496	__memmove_u64s_up(dst, src, u64s);
497}
498
499static inline void memmove_u64s(void *dst, const void *src,
500				unsigned u64s)
501{
502	if (dst < src)
503		__memmove_u64s_down(dst, src, u64s);
504	else
505		__memmove_u64s_up(dst, src, u64s);
506}
507
508/* Set the last few bytes up to a u64 boundary given an offset into a buffer. */
509static inline void memset_u64s_tail(void *s, int c, unsigned bytes)
510{
511	unsigned rem = round_up(bytes, sizeof(u64)) - bytes;
512
513	memset(s + bytes, c, rem);
514}
515
516/* just the memmove, doesn't update @_nr */
517#define __array_insert_item(_array, _nr, _pos)				\
518	memmove(&(_array)[(_pos) + 1],					\
519		&(_array)[(_pos)],					\
520		sizeof((_array)[0]) * ((_nr) - (_pos)))
521
522#define array_insert_item(_array, _nr, _pos, _new_item)			\
523do {									\
524	__array_insert_item(_array, _nr, _pos);				\
525	(_nr)++;							\
526	(_array)[(_pos)] = (_new_item);					\
527} while (0)
528
529#define array_remove_items(_array, _nr, _pos, _nr_to_remove)		\
530do {									\
531	(_nr) -= (_nr_to_remove);					\
532	memmove(&(_array)[(_pos)],					\
533		&(_array)[(_pos) + (_nr_to_remove)],			\
534		sizeof((_array)[0]) * ((_nr) - (_pos)));		\
535} while (0)
536
537#define array_remove_item(_array, _nr, _pos)				\
538	array_remove_items(_array, _nr, _pos, 1)
539
540static inline void __move_gap(void *array, size_t element_size,
541			      size_t nr, size_t size,
542			      size_t old_gap, size_t new_gap)
543{
544	size_t gap_end = old_gap + size - nr;
545
546	if (new_gap < old_gap) {
547		size_t move = old_gap - new_gap;
548
549		memmove(array + element_size * (gap_end - move),
550			array + element_size * (old_gap - move),
551				element_size * move);
552	} else if (new_gap > old_gap) {
553		size_t move = new_gap - old_gap;
554
555		memmove(array + element_size * old_gap,
556			array + element_size * gap_end,
557				element_size * move);
558	}
559}
560
561/* Move the gap in a gap buffer: */
562#define move_gap(_d, _new_gap)						\
563do {									\
564	BUG_ON(_new_gap > (_d)->nr);					\
565	BUG_ON((_d)->gap > (_d)->nr);					\
566									\
567	__move_gap((_d)->data, sizeof((_d)->data[0]),			\
568		   (_d)->nr, (_d)->size, (_d)->gap, _new_gap);		\
569	(_d)->gap = _new_gap;						\
570} while (0)
571
572#define bubble_sort(_base, _nr, _cmp)					\
573do {									\
574	ssize_t _i, _last;						\
575	bool _swapped = true;						\
576									\
577	for (_last= (ssize_t) (_nr) - 1; _last > 0 && _swapped; --_last) {\
578		_swapped = false;					\
579		for (_i = 0; _i < _last; _i++)				\
580			if (_cmp((_base)[_i], (_base)[_i + 1]) > 0) {	\
581				swap((_base)[_i], (_base)[_i + 1]);	\
582				_swapped = true;			\
583			}						\
584	}								\
585} while (0)
586
587#define per_cpu_sum(_p)							\
588({									\
589	typeof(*_p) _ret = 0;						\
590									\
591	int cpu;							\
592	for_each_possible_cpu(cpu)					\
593		_ret += *per_cpu_ptr(_p, cpu);				\
594	_ret;								\
595})
596
597static inline u64 percpu_u64_get(u64 __percpu *src)
598{
599	return per_cpu_sum(src);
600}
601
602static inline void percpu_u64_set(u64 __percpu *dst, u64 src)
603{
604	int cpu;
605
606	for_each_possible_cpu(cpu)
607		*per_cpu_ptr(dst, cpu) = 0;
608	this_cpu_write(*dst, src);
609}
610
611static inline void acc_u64s(u64 *acc, const u64 *src, unsigned nr)
612{
613	for (unsigned i = 0; i < nr; i++)
614		acc[i] += src[i];
615}
616
617static inline void acc_u64s_percpu(u64 *acc, const u64 __percpu *src,
618				   unsigned nr)
619{
620	int cpu;
621
622	for_each_possible_cpu(cpu)
623		acc_u64s(acc, per_cpu_ptr(src, cpu), nr);
624}
625
626static inline void percpu_memset(void __percpu *p, int c, size_t bytes)
627{
628	int cpu;
629
630	for_each_possible_cpu(cpu)
631		memset(per_cpu_ptr(p, cpu), c, bytes);
632}
633
634u64 *bch2_acc_percpu_u64s(u64 __percpu *, unsigned);
635
636#define cmp_int(l, r)		((l > r) - (l < r))
637
638static inline int u8_cmp(u8 l, u8 r)
639{
640	return cmp_int(l, r);
641}
642
643static inline int cmp_le32(__le32 l, __le32 r)
644{
645	return cmp_int(le32_to_cpu(l), le32_to_cpu(r));
646}
647
648#include <linux/uuid.h>
649
650#define QSTR(n) { { { .len = strlen(n) } }, .name = n }
651
652static inline bool qstr_eq(const struct qstr l, const struct qstr r)
653{
654	return l.len == r.len && !memcmp(l.name, r.name, l.len);
655}
656
657void bch2_darray_str_exit(darray_str *);
658int bch2_split_devs(const char *, darray_str *);
659
660#ifdef __KERNEL__
661
662__must_check
663static inline int copy_to_user_errcode(void __user *to, const void *from, unsigned long n)
664{
665	return copy_to_user(to, from, n) ? -EFAULT : 0;
666}
667
668__must_check
669static inline int copy_from_user_errcode(void *to, const void __user *from, unsigned long n)
670{
671	return copy_from_user(to, from, n) ? -EFAULT : 0;
672}
673
674#endif
675
676static inline void mod_bit(long nr, volatile unsigned long *addr, bool v)
677{
678	if (v)
679		set_bit(nr, addr);
680	else
681		clear_bit(nr, addr);
682}
683
684static inline void __set_bit_le64(size_t bit, __le64 *addr)
685{
686	addr[bit / 64] |= cpu_to_le64(BIT_ULL(bit % 64));
687}
688
689static inline void __clear_bit_le64(size_t bit, __le64 *addr)
690{
691	addr[bit / 64] &= ~cpu_to_le64(BIT_ULL(bit % 64));
692}
693
694static inline bool test_bit_le64(size_t bit, __le64 *addr)
695{
696	return (addr[bit / 64] & cpu_to_le64(BIT_ULL(bit % 64))) != 0;
697}
698
699#endif /* _BCACHEFS_UTIL_H */