xref: /linux/fs/bcachefs/util.h (revision 3e7819886281e077e82006fe4804b0d6b0f5643b)
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/sched/clock.h>
12 #include <linux/llist.h>
13 #include <linux/log2.h>
14 #include <linux/percpu.h>
15 #include <linux/preempt.h>
16 #include <linux/ratelimit.h>
17 #include <linux/slab.h>
18 #include <linux/vmalloc.h>
19 #include <linux/workqueue.h>
20 
21 #include "mean_and_variance.h"
22 
23 #include "darray.h"
24 #include "time_stats.h"
25 
26 struct closure;
27 
28 #ifdef CONFIG_BCACHEFS_DEBUG
29 #define EBUG_ON(cond)		BUG_ON(cond)
30 #else
31 #define EBUG_ON(cond)
32 #endif
33 
34 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
35 #define CPU_BIG_ENDIAN		0
36 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
37 #define CPU_BIG_ENDIAN		1
38 #endif
39 
40 /* type hackery */
41 
42 #define type_is_exact(_val, _type)					\
43 	__builtin_types_compatible_p(typeof(_val), _type)
44 
45 #define type_is(_val, _type)						\
46 	(__builtin_types_compatible_p(typeof(_val), _type) ||		\
47 	 __builtin_types_compatible_p(typeof(_val), const _type))
48 
49 /* Userspace doesn't align allocations as nicely as the kernel allocators: */
50 static inline size_t buf_pages(void *p, size_t len)
51 {
52 	return DIV_ROUND_UP(len +
53 			    ((unsigned long) p & (PAGE_SIZE - 1)),
54 			    PAGE_SIZE);
55 }
56 
57 #define HEAP(type)							\
58 struct {								\
59 	size_t size, used;						\
60 	type *data;							\
61 }
62 
63 #define DECLARE_HEAP(type, name) HEAP(type) name
64 
65 #define init_heap(heap, _size, gfp)					\
66 ({									\
67 	(heap)->used = 0;						\
68 	(heap)->size = (_size);						\
69 	(heap)->data = kvmalloc((heap)->size * sizeof((heap)->data[0]),\
70 				 (gfp));				\
71 })
72 
73 #define free_heap(heap)							\
74 do {									\
75 	kvfree((heap)->data);						\
76 	(heap)->data = NULL;						\
77 } while (0)
78 
79 #define heap_set_backpointer(h, i, _fn)					\
80 do {									\
81 	void (*fn)(typeof(h), size_t) = _fn;				\
82 	if (fn)								\
83 		fn(h, i);						\
84 } while (0)
85 
86 #define heap_swap(h, i, j, set_backpointer)				\
87 do {									\
88 	swap((h)->data[i], (h)->data[j]);				\
89 	heap_set_backpointer(h, i, set_backpointer);			\
90 	heap_set_backpointer(h, j, set_backpointer);			\
91 } while (0)
92 
93 #define heap_peek(h)							\
94 ({									\
95 	EBUG_ON(!(h)->used);						\
96 	(h)->data[0];							\
97 })
98 
99 #define heap_full(h)	((h)->used == (h)->size)
100 
101 #define heap_sift_down(h, i, cmp, set_backpointer)			\
102 do {									\
103 	size_t _c, _j = i;						\
104 									\
105 	for (; _j * 2 + 1 < (h)->used; _j = _c) {			\
106 		_c = _j * 2 + 1;					\
107 		if (_c + 1 < (h)->used &&				\
108 		    cmp(h, (h)->data[_c], (h)->data[_c + 1]) >= 0)	\
109 			_c++;						\
110 									\
111 		if (cmp(h, (h)->data[_c], (h)->data[_j]) >= 0)		\
112 			break;						\
113 		heap_swap(h, _c, _j, set_backpointer);			\
114 	}								\
115 } while (0)
116 
117 #define heap_sift_up(h, i, cmp, set_backpointer)			\
118 do {									\
119 	while (i) {							\
120 		size_t p = (i - 1) / 2;					\
121 		if (cmp(h, (h)->data[i], (h)->data[p]) >= 0)		\
122 			break;						\
123 		heap_swap(h, i, p, set_backpointer);			\
124 		i = p;							\
125 	}								\
126 } while (0)
127 
128 #define __heap_add(h, d, cmp, set_backpointer)				\
129 ({									\
130 	size_t _i = (h)->used++;					\
131 	(h)->data[_i] = d;						\
132 	heap_set_backpointer(h, _i, set_backpointer);			\
133 									\
134 	heap_sift_up(h, _i, cmp, set_backpointer);			\
135 	_i;								\
136 })
137 
138 #define heap_add(h, d, cmp, set_backpointer)				\
139 ({									\
140 	bool _r = !heap_full(h);					\
141 	if (_r)								\
142 		__heap_add(h, d, cmp, set_backpointer);			\
143 	_r;								\
144 })
145 
146 #define heap_add_or_replace(h, new, cmp, set_backpointer)		\
147 do {									\
148 	if (!heap_add(h, new, cmp, set_backpointer) &&			\
149 	    cmp(h, new, heap_peek(h)) >= 0) {				\
150 		(h)->data[0] = new;					\
151 		heap_set_backpointer(h, 0, set_backpointer);		\
152 		heap_sift_down(h, 0, cmp, set_backpointer);		\
153 	}								\
154 } while (0)
155 
156 #define heap_del(h, i, cmp, set_backpointer)				\
157 do {									\
158 	size_t _i = (i);						\
159 									\
160 	BUG_ON(_i >= (h)->used);					\
161 	(h)->used--;							\
162 	if ((_i) < (h)->used) {						\
163 		heap_swap(h, _i, (h)->used, set_backpointer);		\
164 		heap_sift_up(h, _i, cmp, set_backpointer);		\
165 		heap_sift_down(h, _i, cmp, set_backpointer);		\
166 	}								\
167 } while (0)
168 
169 #define heap_pop(h, d, cmp, set_backpointer)				\
170 ({									\
171 	bool _r = (h)->used;						\
172 	if (_r) {							\
173 		(d) = (h)->data[0];					\
174 		heap_del(h, 0, cmp, set_backpointer);			\
175 	}								\
176 	_r;								\
177 })
178 
179 #define heap_resort(heap, cmp, set_backpointer)				\
180 do {									\
181 	ssize_t _i;							\
182 	for (_i = (ssize_t) (heap)->used / 2 -  1; _i >= 0; --_i)	\
183 		heap_sift_down(heap, _i, cmp, set_backpointer);		\
184 } while (0)
185 
186 #define ANYSINT_MAX(t)							\
187 	((((t) 1 << (sizeof(t) * 8 - 2)) - (t) 1) * (t) 2 + (t) 1)
188 
189 #include "printbuf.h"
190 
191 #define prt_vprintf(_out, ...)		bch2_prt_vprintf(_out, __VA_ARGS__)
192 #define prt_printf(_out, ...)		bch2_prt_printf(_out, __VA_ARGS__)
193 #define printbuf_str(_buf)		bch2_printbuf_str(_buf)
194 #define printbuf_exit(_buf)		bch2_printbuf_exit(_buf)
195 
196 #define printbuf_tabstops_reset(_buf)	bch2_printbuf_tabstops_reset(_buf)
197 #define printbuf_tabstop_pop(_buf)	bch2_printbuf_tabstop_pop(_buf)
198 #define printbuf_tabstop_push(_buf, _n)	bch2_printbuf_tabstop_push(_buf, _n)
199 
200 #define printbuf_indent_add(_out, _n)	bch2_printbuf_indent_add(_out, _n)
201 #define printbuf_indent_sub(_out, _n)	bch2_printbuf_indent_sub(_out, _n)
202 
203 #define prt_newline(_out)		bch2_prt_newline(_out)
204 #define prt_tab(_out)			bch2_prt_tab(_out)
205 #define prt_tab_rjust(_out)		bch2_prt_tab_rjust(_out)
206 
207 #define prt_bytes_indented(...)		bch2_prt_bytes_indented(__VA_ARGS__)
208 #define prt_u64(_out, _v)		prt_printf(_out, "%llu", (u64) (_v))
209 #define prt_human_readable_u64(...)	bch2_prt_human_readable_u64(__VA_ARGS__)
210 #define prt_human_readable_s64(...)	bch2_prt_human_readable_s64(__VA_ARGS__)
211 #define prt_units_u64(...)		bch2_prt_units_u64(__VA_ARGS__)
212 #define prt_units_s64(...)		bch2_prt_units_s64(__VA_ARGS__)
213 #define prt_string_option(...)		bch2_prt_string_option(__VA_ARGS__)
214 #define prt_bitflags(...)		bch2_prt_bitflags(__VA_ARGS__)
215 #define prt_bitflags_vector(...)	bch2_prt_bitflags_vector(__VA_ARGS__)
216 
217 void bch2_pr_time_units(struct printbuf *, u64);
218 void bch2_prt_datetime(struct printbuf *, time64_t);
219 
220 #ifdef __KERNEL__
221 static inline void uuid_unparse_lower(u8 *uuid, char *out)
222 {
223 	sprintf(out, "%pUb", uuid);
224 }
225 #else
226 #include <uuid/uuid.h>
227 #endif
228 
229 static inline void pr_uuid(struct printbuf *out, u8 *uuid)
230 {
231 	char uuid_str[40];
232 
233 	uuid_unparse_lower(uuid, uuid_str);
234 	prt_printf(out, "%s", uuid_str);
235 }
236 
237 int bch2_strtoint_h(const char *, int *);
238 int bch2_strtouint_h(const char *, unsigned int *);
239 int bch2_strtoll_h(const char *, long long *);
240 int bch2_strtoull_h(const char *, unsigned long long *);
241 int bch2_strtou64_h(const char *, u64 *);
242 
243 static inline int bch2_strtol_h(const char *cp, long *res)
244 {
245 #if BITS_PER_LONG == 32
246 	return bch2_strtoint_h(cp, (int *) res);
247 #else
248 	return bch2_strtoll_h(cp, (long long *) res);
249 #endif
250 }
251 
252 static inline int bch2_strtoul_h(const char *cp, long *res)
253 {
254 #if BITS_PER_LONG == 32
255 	return bch2_strtouint_h(cp, (unsigned int *) res);
256 #else
257 	return bch2_strtoull_h(cp, (unsigned long long *) res);
258 #endif
259 }
260 
261 #define strtoi_h(cp, res)						\
262 	( type_is(*res, int)		? bch2_strtoint_h(cp, (void *) res)\
263 	: type_is(*res, long)		? bch2_strtol_h(cp, (void *) res)\
264 	: type_is(*res, long long)	? bch2_strtoll_h(cp, (void *) res)\
265 	: type_is(*res, unsigned)	? bch2_strtouint_h(cp, (void *) res)\
266 	: type_is(*res, unsigned long)	? bch2_strtoul_h(cp, (void *) res)\
267 	: type_is(*res, unsigned long long) ? bch2_strtoull_h(cp, (void *) res)\
268 	: -EINVAL)
269 
270 #define strtoul_safe(cp, var)						\
271 ({									\
272 	unsigned long _v;						\
273 	int _r = kstrtoul(cp, 10, &_v);					\
274 	if (!_r)							\
275 		var = _v;						\
276 	_r;								\
277 })
278 
279 #define strtoul_safe_clamp(cp, var, min, max)				\
280 ({									\
281 	unsigned long _v;						\
282 	int _r = kstrtoul(cp, 10, &_v);					\
283 	if (!_r)							\
284 		var = clamp_t(typeof(var), _v, min, max);		\
285 	_r;								\
286 })
287 
288 #define strtoul_safe_restrict(cp, var, min, max)			\
289 ({									\
290 	unsigned long _v;						\
291 	int _r = kstrtoul(cp, 10, &_v);					\
292 	if (!_r && _v >= min && _v <= max)				\
293 		var = _v;						\
294 	else								\
295 		_r = -EINVAL;						\
296 	_r;								\
297 })
298 
299 #define snprint(out, var)						\
300 	prt_printf(out,							\
301 		   type_is(var, int)		? "%i\n"		\
302 		 : type_is(var, unsigned)	? "%u\n"		\
303 		 : type_is(var, long)		? "%li\n"		\
304 		 : type_is(var, unsigned long)	? "%lu\n"		\
305 		 : type_is(var, s64)		? "%lli\n"		\
306 		 : type_is(var, u64)		? "%llu\n"		\
307 		 : type_is(var, char *)		? "%s\n"		\
308 		 : "%i\n", var)
309 
310 bool bch2_is_zero(const void *, size_t);
311 
312 u64 bch2_read_flag_list(char *, const char * const[]);
313 
314 void bch2_prt_u64_base2_nbits(struct printbuf *, u64, unsigned);
315 void bch2_prt_u64_base2(struct printbuf *, u64);
316 
317 void bch2_print_string_as_lines(const char *prefix, const char *lines);
318 void bch2_print_string_as_lines_nonblocking(const char *prefix, const char *lines);
319 
320 typedef DARRAY(unsigned long) bch_stacktrace;
321 int bch2_save_backtrace(bch_stacktrace *stack, struct task_struct *, unsigned, gfp_t);
322 void bch2_prt_backtrace(struct printbuf *, bch_stacktrace *);
323 int bch2_prt_task_backtrace(struct printbuf *, struct task_struct *, unsigned, gfp_t);
324 
325 static inline void prt_bdevname(struct printbuf *out, struct block_device *bdev)
326 {
327 #ifdef __KERNEL__
328 	prt_printf(out, "%pg", bdev);
329 #else
330 	prt_str(out, bdev->name);
331 #endif
332 }
333 
334 void bch2_time_stats_to_text(struct printbuf *, struct bch2_time_stats *);
335 
336 #define ewma_add(ewma, val, weight)					\
337 ({									\
338 	typeof(ewma) _ewma = (ewma);					\
339 	typeof(weight) _weight = (weight);				\
340 									\
341 	(((_ewma << _weight) - _ewma) + (val)) >> _weight;		\
342 })
343 
344 struct bch_ratelimit {
345 	/* Next time we want to do some work, in nanoseconds */
346 	u64			next;
347 
348 	/*
349 	 * Rate at which we want to do work, in units per nanosecond
350 	 * The units here correspond to the units passed to
351 	 * bch2_ratelimit_increment()
352 	 */
353 	unsigned		rate;
354 };
355 
356 static inline void bch2_ratelimit_reset(struct bch_ratelimit *d)
357 {
358 	d->next = local_clock();
359 }
360 
361 u64 bch2_ratelimit_delay(struct bch_ratelimit *);
362 void bch2_ratelimit_increment(struct bch_ratelimit *, u64);
363 
364 struct bch_pd_controller {
365 	struct bch_ratelimit	rate;
366 	unsigned long		last_update;
367 
368 	s64			last_actual;
369 	s64			smoothed_derivative;
370 
371 	unsigned		p_term_inverse;
372 	unsigned		d_smooth;
373 	unsigned		d_term;
374 
375 	/* for exporting to sysfs (no effect on behavior) */
376 	s64			last_derivative;
377 	s64			last_proportional;
378 	s64			last_change;
379 	s64			last_target;
380 
381 	/*
382 	 * If true, the rate will not increase if bch2_ratelimit_delay()
383 	 * is not being called often enough.
384 	 */
385 	bool			backpressure;
386 };
387 
388 void bch2_pd_controller_update(struct bch_pd_controller *, s64, s64, int);
389 void bch2_pd_controller_init(struct bch_pd_controller *);
390 void bch2_pd_controller_debug_to_text(struct printbuf *, struct bch_pd_controller *);
391 
392 #define sysfs_pd_controller_attribute(name)				\
393 	rw_attribute(name##_rate);					\
394 	rw_attribute(name##_rate_bytes);				\
395 	rw_attribute(name##_rate_d_term);				\
396 	rw_attribute(name##_rate_p_term_inverse);			\
397 	read_attribute(name##_rate_debug)
398 
399 #define sysfs_pd_controller_files(name)					\
400 	&sysfs_##name##_rate,						\
401 	&sysfs_##name##_rate_bytes,					\
402 	&sysfs_##name##_rate_d_term,					\
403 	&sysfs_##name##_rate_p_term_inverse,				\
404 	&sysfs_##name##_rate_debug
405 
406 #define sysfs_pd_controller_show(name, var)				\
407 do {									\
408 	sysfs_hprint(name##_rate,		(var)->rate.rate);	\
409 	sysfs_print(name##_rate_bytes,		(var)->rate.rate);	\
410 	sysfs_print(name##_rate_d_term,		(var)->d_term);		\
411 	sysfs_print(name##_rate_p_term_inverse,	(var)->p_term_inverse);	\
412 									\
413 	if (attr == &sysfs_##name##_rate_debug)				\
414 		bch2_pd_controller_debug_to_text(out, var);		\
415 } while (0)
416 
417 #define sysfs_pd_controller_store(name, var)				\
418 do {									\
419 	sysfs_strtoul_clamp(name##_rate,				\
420 			    (var)->rate.rate, 1, UINT_MAX);		\
421 	sysfs_strtoul_clamp(name##_rate_bytes,				\
422 			    (var)->rate.rate, 1, UINT_MAX);		\
423 	sysfs_strtoul(name##_rate_d_term,	(var)->d_term);		\
424 	sysfs_strtoul_clamp(name##_rate_p_term_inverse,			\
425 			    (var)->p_term_inverse, 1, INT_MAX);		\
426 } while (0)
427 
428 #define container_of_or_null(ptr, type, member)				\
429 ({									\
430 	typeof(ptr) _ptr = ptr;						\
431 	_ptr ? container_of(_ptr, type, member) : NULL;			\
432 })
433 
434 /* Does linear interpolation between powers of two */
435 static inline unsigned fract_exp_two(unsigned x, unsigned fract_bits)
436 {
437 	unsigned fract = x & ~(~0 << fract_bits);
438 
439 	x >>= fract_bits;
440 	x   = 1 << x;
441 	x  += (x * fract) >> fract_bits;
442 
443 	return x;
444 }
445 
446 void bch2_bio_map(struct bio *bio, void *base, size_t);
447 int bch2_bio_alloc_pages(struct bio *, size_t, gfp_t);
448 
449 #define closure_bio_submit(bio, cl)					\
450 do {									\
451 	closure_get(cl);						\
452 	submit_bio(bio);						\
453 } while (0)
454 
455 #define kthread_wait(cond)						\
456 ({									\
457 	int _ret = 0;							\
458 									\
459 	while (1) {							\
460 		set_current_state(TASK_INTERRUPTIBLE);			\
461 		if (kthread_should_stop()) {				\
462 			_ret = -1;					\
463 			break;						\
464 		}							\
465 									\
466 		if (cond)						\
467 			break;						\
468 									\
469 		schedule();						\
470 	}								\
471 	set_current_state(TASK_RUNNING);				\
472 	_ret;								\
473 })
474 
475 #define kthread_wait_freezable(cond)					\
476 ({									\
477 	int _ret = 0;							\
478 	while (1) {							\
479 		set_current_state(TASK_INTERRUPTIBLE);			\
480 		if (kthread_should_stop()) {				\
481 			_ret = -1;					\
482 			break;						\
483 		}							\
484 									\
485 		if (cond)						\
486 			break;						\
487 									\
488 		schedule();						\
489 		try_to_freeze();					\
490 	}								\
491 	set_current_state(TASK_RUNNING);				\
492 	_ret;								\
493 })
494 
495 size_t bch2_rand_range(size_t);
496 
497 void memcpy_to_bio(struct bio *, struct bvec_iter, const void *);
498 void memcpy_from_bio(void *, struct bio *, struct bvec_iter);
499 
500 static inline void memcpy_u64s_small(void *dst, const void *src,
501 				     unsigned u64s)
502 {
503 	u64 *d = dst;
504 	const u64 *s = src;
505 
506 	while (u64s--)
507 		*d++ = *s++;
508 }
509 
510 static inline void __memcpy_u64s(void *dst, const void *src,
511 				 unsigned u64s)
512 {
513 #ifdef CONFIG_X86_64
514 	long d0, d1, d2;
515 
516 	asm volatile("rep ; movsq"
517 		     : "=&c" (d0), "=&D" (d1), "=&S" (d2)
518 		     : "0" (u64s), "1" (dst), "2" (src)
519 		     : "memory");
520 #else
521 	u64 *d = dst;
522 	const u64 *s = src;
523 
524 	while (u64s--)
525 		*d++ = *s++;
526 #endif
527 }
528 
529 static inline void memcpy_u64s(void *dst, const void *src,
530 			       unsigned u64s)
531 {
532 	EBUG_ON(!(dst >= src + u64s * sizeof(u64) ||
533 		 dst + u64s * sizeof(u64) <= src));
534 
535 	__memcpy_u64s(dst, src, u64s);
536 }
537 
538 static inline void __memmove_u64s_down(void *dst, const void *src,
539 				       unsigned u64s)
540 {
541 	__memcpy_u64s(dst, src, u64s);
542 }
543 
544 static inline void memmove_u64s_down(void *dst, const void *src,
545 				     unsigned u64s)
546 {
547 	EBUG_ON(dst > src);
548 
549 	__memmove_u64s_down(dst, src, u64s);
550 }
551 
552 static inline void __memmove_u64s_down_small(void *dst, const void *src,
553 				       unsigned u64s)
554 {
555 	memcpy_u64s_small(dst, src, u64s);
556 }
557 
558 static inline void memmove_u64s_down_small(void *dst, const void *src,
559 				     unsigned u64s)
560 {
561 	EBUG_ON(dst > src);
562 
563 	__memmove_u64s_down_small(dst, src, u64s);
564 }
565 
566 static inline void __memmove_u64s_up_small(void *_dst, const void *_src,
567 					   unsigned u64s)
568 {
569 	u64 *dst = (u64 *) _dst + u64s;
570 	u64 *src = (u64 *) _src + u64s;
571 
572 	while (u64s--)
573 		*--dst = *--src;
574 }
575 
576 static inline void memmove_u64s_up_small(void *dst, const void *src,
577 					 unsigned u64s)
578 {
579 	EBUG_ON(dst < src);
580 
581 	__memmove_u64s_up_small(dst, src, u64s);
582 }
583 
584 static inline void __memmove_u64s_up(void *_dst, const void *_src,
585 				     unsigned u64s)
586 {
587 	u64 *dst = (u64 *) _dst + u64s - 1;
588 	u64 *src = (u64 *) _src + u64s - 1;
589 
590 #ifdef CONFIG_X86_64
591 	long d0, d1, d2;
592 
593 	asm volatile("std ;\n"
594 		     "rep ; movsq\n"
595 		     "cld ;\n"
596 		     : "=&c" (d0), "=&D" (d1), "=&S" (d2)
597 		     : "0" (u64s), "1" (dst), "2" (src)
598 		     : "memory");
599 #else
600 	while (u64s--)
601 		*dst-- = *src--;
602 #endif
603 }
604 
605 static inline void memmove_u64s_up(void *dst, const void *src,
606 				   unsigned u64s)
607 {
608 	EBUG_ON(dst < src);
609 
610 	__memmove_u64s_up(dst, src, u64s);
611 }
612 
613 static inline void memmove_u64s(void *dst, const void *src,
614 				unsigned u64s)
615 {
616 	if (dst < src)
617 		__memmove_u64s_down(dst, src, u64s);
618 	else
619 		__memmove_u64s_up(dst, src, u64s);
620 }
621 
622 /* Set the last few bytes up to a u64 boundary given an offset into a buffer. */
623 static inline void memset_u64s_tail(void *s, int c, unsigned bytes)
624 {
625 	unsigned rem = round_up(bytes, sizeof(u64)) - bytes;
626 
627 	memset(s + bytes, c, rem);
628 }
629 
630 /* just the memmove, doesn't update @_nr */
631 #define __array_insert_item(_array, _nr, _pos)				\
632 	memmove(&(_array)[(_pos) + 1],					\
633 		&(_array)[(_pos)],					\
634 		sizeof((_array)[0]) * ((_nr) - (_pos)))
635 
636 #define array_insert_item(_array, _nr, _pos, _new_item)			\
637 do {									\
638 	__array_insert_item(_array, _nr, _pos);				\
639 	(_nr)++;							\
640 	(_array)[(_pos)] = (_new_item);					\
641 } while (0)
642 
643 #define array_remove_items(_array, _nr, _pos, _nr_to_remove)		\
644 do {									\
645 	(_nr) -= (_nr_to_remove);					\
646 	memmove(&(_array)[(_pos)],					\
647 		&(_array)[(_pos) + (_nr_to_remove)],			\
648 		sizeof((_array)[0]) * ((_nr) - (_pos)));		\
649 } while (0)
650 
651 #define array_remove_item(_array, _nr, _pos)				\
652 	array_remove_items(_array, _nr, _pos, 1)
653 
654 static inline void __move_gap(void *array, size_t element_size,
655 			      size_t nr, size_t size,
656 			      size_t old_gap, size_t new_gap)
657 {
658 	size_t gap_end = old_gap + size - nr;
659 
660 	if (new_gap < old_gap) {
661 		size_t move = old_gap - new_gap;
662 
663 		memmove(array + element_size * (gap_end - move),
664 			array + element_size * (old_gap - move),
665 				element_size * move);
666 	} else if (new_gap > old_gap) {
667 		size_t move = new_gap - old_gap;
668 
669 		memmove(array + element_size * old_gap,
670 			array + element_size * gap_end,
671 				element_size * move);
672 	}
673 }
674 
675 /* Move the gap in a gap buffer: */
676 #define move_gap(_d, _new_gap)						\
677 do {									\
678 	BUG_ON(_new_gap > (_d)->nr);					\
679 	BUG_ON((_d)->gap > (_d)->nr);					\
680 									\
681 	__move_gap((_d)->data, sizeof((_d)->data[0]),			\
682 		   (_d)->nr, (_d)->size, (_d)->gap, _new_gap);		\
683 	(_d)->gap = _new_gap;						\
684 } while (0)
685 
686 #define bubble_sort(_base, _nr, _cmp)					\
687 do {									\
688 	ssize_t _i, _last;						\
689 	bool _swapped = true;						\
690 									\
691 	for (_last= (ssize_t) (_nr) - 1; _last > 0 && _swapped; --_last) {\
692 		_swapped = false;					\
693 		for (_i = 0; _i < _last; _i++)				\
694 			if (_cmp((_base)[_i], (_base)[_i + 1]) > 0) {	\
695 				swap((_base)[_i], (_base)[_i + 1]);	\
696 				_swapped = true;			\
697 			}						\
698 	}								\
699 } while (0)
700 
701 static inline u64 percpu_u64_get(u64 __percpu *src)
702 {
703 	u64 ret = 0;
704 	int cpu;
705 
706 	for_each_possible_cpu(cpu)
707 		ret += *per_cpu_ptr(src, cpu);
708 	return ret;
709 }
710 
711 static inline void percpu_u64_set(u64 __percpu *dst, u64 src)
712 {
713 	int cpu;
714 
715 	for_each_possible_cpu(cpu)
716 		*per_cpu_ptr(dst, cpu) = 0;
717 	this_cpu_write(*dst, src);
718 }
719 
720 static inline void acc_u64s(u64 *acc, const u64 *src, unsigned nr)
721 {
722 	unsigned i;
723 
724 	for (i = 0; i < nr; i++)
725 		acc[i] += src[i];
726 }
727 
728 static inline void acc_u64s_percpu(u64 *acc, const u64 __percpu *src,
729 				   unsigned nr)
730 {
731 	int cpu;
732 
733 	for_each_possible_cpu(cpu)
734 		acc_u64s(acc, per_cpu_ptr(src, cpu), nr);
735 }
736 
737 static inline void percpu_memset(void __percpu *p, int c, size_t bytes)
738 {
739 	int cpu;
740 
741 	for_each_possible_cpu(cpu)
742 		memset(per_cpu_ptr(p, cpu), c, bytes);
743 }
744 
745 u64 *bch2_acc_percpu_u64s(u64 __percpu *, unsigned);
746 
747 #define cmp_int(l, r)		((l > r) - (l < r))
748 
749 static inline int u8_cmp(u8 l, u8 r)
750 {
751 	return cmp_int(l, r);
752 }
753 
754 static inline int cmp_le32(__le32 l, __le32 r)
755 {
756 	return cmp_int(le32_to_cpu(l), le32_to_cpu(r));
757 }
758 
759 #include <linux/uuid.h>
760 
761 #define QSTR(n) { { { .len = strlen(n) } }, .name = n }
762 
763 static inline bool qstr_eq(const struct qstr l, const struct qstr r)
764 {
765 	return l.len == r.len && !memcmp(l.name, r.name, l.len);
766 }
767 
768 void bch2_darray_str_exit(darray_str *);
769 int bch2_split_devs(const char *, darray_str *);
770 
771 #ifdef __KERNEL__
772 
773 __must_check
774 static inline int copy_to_user_errcode(void __user *to, const void *from, unsigned long n)
775 {
776 	return copy_to_user(to, from, n) ? -EFAULT : 0;
777 }
778 
779 __must_check
780 static inline int copy_from_user_errcode(void *to, const void __user *from, unsigned long n)
781 {
782 	return copy_from_user(to, from, n) ? -EFAULT : 0;
783 }
784 
785 #endif
786 
787 static inline void mod_bit(long nr, volatile unsigned long *addr, bool v)
788 {
789 	if (v)
790 		set_bit(nr, addr);
791 	else
792 		clear_bit(nr, addr);
793 }
794 
795 static inline void __set_bit_le64(size_t bit, __le64 *addr)
796 {
797 	addr[bit / 64] |= cpu_to_le64(BIT_ULL(bit % 64));
798 }
799 
800 static inline void __clear_bit_le64(size_t bit, __le64 *addr)
801 {
802 	addr[bit / 64] &= ~cpu_to_le64(BIT_ULL(bit % 64));
803 }
804 
805 static inline bool test_bit_le64(size_t bit, __le64 *addr)
806 {
807 	return (addr[bit / 64] & cpu_to_le64(BIT_ULL(bit % 64))) != 0;
808 }
809 
810 #endif /* _BCACHEFS_UTIL_H */
811