xref: /linux/lib/kunit_iov_iter.c (revision d8c6b3fc918dd7b93c66e49ff8640746b84fbfe9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* I/O iterator tests.  This can only test kernel-backed iterator types.
3  *
4  * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/mm.h>
13 #include <linux/uio.h>
14 #include <linux/bvec.h>
15 #include <kunit/test.h>
16 
17 MODULE_DESCRIPTION("iov_iter testing");
18 MODULE_AUTHOR("David Howells <dhowells@redhat.com>");
19 MODULE_LICENSE("GPL");
20 
21 struct kvec_test_range {
22 	int	from, to;
23 };
24 
25 static const struct kvec_test_range kvec_test_ranges[] = {
26 	{ 0x00002, 0x00002 },
27 	{ 0x00027, 0x03000 },
28 	{ 0x05193, 0x18794 },
29 	{ 0x20000, 0x20000 },
30 	{ 0x20000, 0x24000 },
31 	{ 0x24000, 0x27001 },
32 	{ 0x29000, 0xffffb },
33 	{ 0xffffd, 0xffffe },
34 	{ -1 }
35 };
36 
37 static inline u8 pattern(unsigned long x)
38 {
39 	return x & 0xff;
40 }
41 
42 static void iov_kunit_unmap(void *data)
43 {
44 	vunmap(data);
45 }
46 
47 static void *__init iov_kunit_create_buffer(struct kunit *test,
48 					    struct page ***ppages,
49 					    size_t npages)
50 {
51 	struct page **pages;
52 	unsigned long got;
53 	void *buffer;
54 
55 	pages = kunit_kcalloc(test, npages, sizeof(struct page *), GFP_KERNEL);
56         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pages);
57 	*ppages = pages;
58 
59 	got = alloc_pages_bulk_array(GFP_KERNEL, npages, pages);
60 	if (got != npages) {
61 		release_pages(pages, got);
62 		KUNIT_ASSERT_EQ(test, got, npages);
63 	}
64 
65 	buffer = vmap(pages, npages, VM_MAP | VM_MAP_PUT_PAGES, PAGE_KERNEL);
66         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buffer);
67 
68 	kunit_add_action_or_reset(test, iov_kunit_unmap, buffer);
69 	return buffer;
70 }
71 
72 static void __init iov_kunit_load_kvec(struct kunit *test,
73 				       struct iov_iter *iter, int dir,
74 				       struct kvec *kvec, unsigned int kvmax,
75 				       void *buffer, size_t bufsize,
76 				       const struct kvec_test_range *pr)
77 {
78 	size_t size = 0;
79 	int i;
80 
81 	for (i = 0; i < kvmax; i++, pr++) {
82 		if (pr->from < 0)
83 			break;
84 		KUNIT_ASSERT_GE(test, pr->to, pr->from);
85 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
86 		kvec[i].iov_base = buffer + pr->from;
87 		kvec[i].iov_len = pr->to - pr->from;
88 		size += pr->to - pr->from;
89 	}
90 	KUNIT_ASSERT_LE(test, size, bufsize);
91 
92 	iov_iter_kvec(iter, dir, kvec, i, size);
93 }
94 
95 /*
96  * Test copying to a ITER_KVEC-type iterator.
97  */
98 static void __init iov_kunit_copy_to_kvec(struct kunit *test)
99 {
100 	const struct kvec_test_range *pr;
101 	struct iov_iter iter;
102 	struct page **spages, **bpages;
103 	struct kvec kvec[8];
104 	u8 *scratch, *buffer;
105 	size_t bufsize, npages, size, copied;
106 	int i, patt;
107 
108 	bufsize = 0x100000;
109 	npages = bufsize / PAGE_SIZE;
110 
111 	scratch = iov_kunit_create_buffer(test, &spages, npages);
112 	for (i = 0; i < bufsize; i++)
113 		scratch[i] = pattern(i);
114 
115 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
116 	memset(buffer, 0, bufsize);
117 
118 	iov_kunit_load_kvec(test, &iter, READ, kvec, ARRAY_SIZE(kvec),
119 			    buffer, bufsize, kvec_test_ranges);
120 	size = iter.count;
121 
122 	copied = copy_to_iter(scratch, size, &iter);
123 
124 	KUNIT_EXPECT_EQ(test, copied, size);
125 	KUNIT_EXPECT_EQ(test, iter.count, 0);
126 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
127 
128 	/* Build the expected image in the scratch buffer. */
129 	patt = 0;
130 	memset(scratch, 0, bufsize);
131 	for (pr = kvec_test_ranges; pr->from >= 0; pr++)
132 		for (i = pr->from; i < pr->to; i++)
133 			scratch[i] = pattern(patt++);
134 
135 	/* Compare the images */
136 	for (i = 0; i < bufsize; i++) {
137 		KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
138 		if (buffer[i] != scratch[i])
139 			return;
140 	}
141 
142 	KUNIT_SUCCEED();
143 }
144 
145 /*
146  * Test copying from a ITER_KVEC-type iterator.
147  */
148 static void __init iov_kunit_copy_from_kvec(struct kunit *test)
149 {
150 	const struct kvec_test_range *pr;
151 	struct iov_iter iter;
152 	struct page **spages, **bpages;
153 	struct kvec kvec[8];
154 	u8 *scratch, *buffer;
155 	size_t bufsize, npages, size, copied;
156 	int i, j;
157 
158 	bufsize = 0x100000;
159 	npages = bufsize / PAGE_SIZE;
160 
161 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
162 	for (i = 0; i < bufsize; i++)
163 		buffer[i] = pattern(i);
164 
165 	scratch = iov_kunit_create_buffer(test, &spages, npages);
166 	memset(scratch, 0, bufsize);
167 
168 	iov_kunit_load_kvec(test, &iter, WRITE, kvec, ARRAY_SIZE(kvec),
169 			    buffer, bufsize, kvec_test_ranges);
170 	size = min(iter.count, bufsize);
171 
172 	copied = copy_from_iter(scratch, size, &iter);
173 
174 	KUNIT_EXPECT_EQ(test, copied, size);
175 	KUNIT_EXPECT_EQ(test, iter.count, 0);
176 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
177 
178 	/* Build the expected image in the main buffer. */
179 	i = 0;
180 	memset(buffer, 0, bufsize);
181 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
182 		for (j = pr->from; j < pr->to; j++) {
183 			buffer[i++] = pattern(j);
184 			if (i >= bufsize)
185 				goto stop;
186 		}
187 	}
188 stop:
189 
190 	/* Compare the images */
191 	for (i = 0; i < bufsize; i++) {
192 		KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
193 		if (scratch[i] != buffer[i])
194 			return;
195 	}
196 
197 	KUNIT_SUCCEED();
198 }
199 
200 struct bvec_test_range {
201 	int	page, from, to;
202 };
203 
204 static const struct bvec_test_range bvec_test_ranges[] = {
205 	{ 0, 0x0002, 0x0002 },
206 	{ 1, 0x0027, 0x0893 },
207 	{ 2, 0x0193, 0x0794 },
208 	{ 3, 0x0000, 0x1000 },
209 	{ 4, 0x0000, 0x1000 },
210 	{ 5, 0x0000, 0x1000 },
211 	{ 6, 0x0000, 0x0ffb },
212 	{ 6, 0x0ffd, 0x0ffe },
213 	{ -1, -1, -1 }
214 };
215 
216 static void __init iov_kunit_load_bvec(struct kunit *test,
217 				       struct iov_iter *iter, int dir,
218 				       struct bio_vec *bvec, unsigned int bvmax,
219 				       struct page **pages, size_t npages,
220 				       size_t bufsize,
221 				       const struct bvec_test_range *pr)
222 {
223 	struct page *can_merge = NULL, *page;
224 	size_t size = 0;
225 	int i;
226 
227 	for (i = 0; i < bvmax; i++, pr++) {
228 		if (pr->from < 0)
229 			break;
230 		KUNIT_ASSERT_LT(test, pr->page, npages);
231 		KUNIT_ASSERT_LT(test, pr->page * PAGE_SIZE, bufsize);
232 		KUNIT_ASSERT_GE(test, pr->from, 0);
233 		KUNIT_ASSERT_GE(test, pr->to, pr->from);
234 		KUNIT_ASSERT_LE(test, pr->to, PAGE_SIZE);
235 
236 		page = pages[pr->page];
237 		if (pr->from == 0 && pr->from != pr->to && page == can_merge) {
238 			i--;
239 			bvec[i].bv_len += pr->to;
240 		} else {
241 			bvec_set_page(&bvec[i], page, pr->to - pr->from, pr->from);
242 		}
243 
244 		size += pr->to - pr->from;
245 		if ((pr->to & ~PAGE_MASK) == 0)
246 			can_merge = page + pr->to / PAGE_SIZE;
247 		else
248 			can_merge = NULL;
249 	}
250 
251 	iov_iter_bvec(iter, dir, bvec, i, size);
252 }
253 
254 /*
255  * Test copying to a ITER_BVEC-type iterator.
256  */
257 static void __init iov_kunit_copy_to_bvec(struct kunit *test)
258 {
259 	const struct bvec_test_range *pr;
260 	struct iov_iter iter;
261 	struct bio_vec bvec[8];
262 	struct page **spages, **bpages;
263 	u8 *scratch, *buffer;
264 	size_t bufsize, npages, size, copied;
265 	int i, b, patt;
266 
267 	bufsize = 0x100000;
268 	npages = bufsize / PAGE_SIZE;
269 
270 	scratch = iov_kunit_create_buffer(test, &spages, npages);
271 	for (i = 0; i < bufsize; i++)
272 		scratch[i] = pattern(i);
273 
274 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
275 	memset(buffer, 0, bufsize);
276 
277 	iov_kunit_load_bvec(test, &iter, READ, bvec, ARRAY_SIZE(bvec),
278 			    bpages, npages, bufsize, bvec_test_ranges);
279 	size = iter.count;
280 
281 	copied = copy_to_iter(scratch, size, &iter);
282 
283 	KUNIT_EXPECT_EQ(test, copied, size);
284 	KUNIT_EXPECT_EQ(test, iter.count, 0);
285 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
286 
287 	/* Build the expected image in the scratch buffer. */
288 	b = 0;
289 	patt = 0;
290 	memset(scratch, 0, bufsize);
291 	for (pr = bvec_test_ranges; pr->from >= 0; pr++, b++) {
292 		u8 *p = scratch + pr->page * PAGE_SIZE;
293 
294 		for (i = pr->from; i < pr->to; i++)
295 			p[i] = pattern(patt++);
296 	}
297 
298 	/* Compare the images */
299 	for (i = 0; i < bufsize; i++) {
300 		KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
301 		if (buffer[i] != scratch[i])
302 			return;
303 	}
304 
305 	KUNIT_SUCCEED();
306 }
307 
308 /*
309  * Test copying from a ITER_BVEC-type iterator.
310  */
311 static void __init iov_kunit_copy_from_bvec(struct kunit *test)
312 {
313 	const struct bvec_test_range *pr;
314 	struct iov_iter iter;
315 	struct bio_vec bvec[8];
316 	struct page **spages, **bpages;
317 	u8 *scratch, *buffer;
318 	size_t bufsize, npages, size, copied;
319 	int i, j;
320 
321 	bufsize = 0x100000;
322 	npages = bufsize / PAGE_SIZE;
323 
324 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
325 	for (i = 0; i < bufsize; i++)
326 		buffer[i] = pattern(i);
327 
328 	scratch = iov_kunit_create_buffer(test, &spages, npages);
329 	memset(scratch, 0, bufsize);
330 
331 	iov_kunit_load_bvec(test, &iter, WRITE, bvec, ARRAY_SIZE(bvec),
332 			    bpages, npages, bufsize, bvec_test_ranges);
333 	size = iter.count;
334 
335 	copied = copy_from_iter(scratch, size, &iter);
336 
337 	KUNIT_EXPECT_EQ(test, copied, size);
338 	KUNIT_EXPECT_EQ(test, iter.count, 0);
339 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
340 
341 	/* Build the expected image in the main buffer. */
342 	i = 0;
343 	memset(buffer, 0, bufsize);
344 	for (pr = bvec_test_ranges; pr->from >= 0; pr++) {
345 		size_t patt = pr->page * PAGE_SIZE;
346 
347 		for (j = pr->from; j < pr->to; j++) {
348 			buffer[i++] = pattern(patt + j);
349 			if (i >= bufsize)
350 				goto stop;
351 		}
352 	}
353 stop:
354 
355 	/* Compare the images */
356 	for (i = 0; i < bufsize; i++) {
357 		KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
358 		if (scratch[i] != buffer[i])
359 			return;
360 	}
361 
362 	KUNIT_SUCCEED();
363 }
364 
365 static void iov_kunit_destroy_xarray(void *data)
366 {
367 	struct xarray *xarray = data;
368 
369 	xa_destroy(xarray);
370 	kfree(xarray);
371 }
372 
373 static void __init iov_kunit_load_xarray(struct kunit *test,
374 					 struct iov_iter *iter, int dir,
375 					 struct xarray *xarray,
376 					 struct page **pages, size_t npages)
377 {
378 	size_t size = 0;
379 	int i;
380 
381 	for (i = 0; i < npages; i++) {
382 		void *x = xa_store(xarray, i, pages[i], GFP_KERNEL);
383 
384 		KUNIT_ASSERT_FALSE(test, xa_is_err(x));
385 		size += PAGE_SIZE;
386 	}
387 	iov_iter_xarray(iter, dir, xarray, 0, size);
388 }
389 
390 static struct xarray *iov_kunit_create_xarray(struct kunit *test)
391 {
392 	struct xarray *xarray;
393 
394 	xarray = kzalloc(sizeof(struct xarray), GFP_KERNEL);
395 	xa_init(xarray);
396 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xarray);
397 	kunit_add_action_or_reset(test, iov_kunit_destroy_xarray, xarray);
398 	return xarray;
399 }
400 
401 /*
402  * Test copying to a ITER_XARRAY-type iterator.
403  */
404 static void __init iov_kunit_copy_to_xarray(struct kunit *test)
405 {
406 	const struct kvec_test_range *pr;
407 	struct iov_iter iter;
408 	struct xarray *xarray;
409 	struct page **spages, **bpages;
410 	u8 *scratch, *buffer;
411 	size_t bufsize, npages, size, copied;
412 	int i, patt;
413 
414 	bufsize = 0x100000;
415 	npages = bufsize / PAGE_SIZE;
416 
417 	xarray = iov_kunit_create_xarray(test);
418 
419 	scratch = iov_kunit_create_buffer(test, &spages, npages);
420 	for (i = 0; i < bufsize; i++)
421 		scratch[i] = pattern(i);
422 
423 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
424 	memset(buffer, 0, bufsize);
425 
426 	iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
427 
428 	i = 0;
429 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
430 		size = pr->to - pr->from;
431 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
432 
433 		iov_iter_xarray(&iter, READ, xarray, pr->from, size);
434 		copied = copy_to_iter(scratch + i, size, &iter);
435 
436 		KUNIT_EXPECT_EQ(test, copied, size);
437 		KUNIT_EXPECT_EQ(test, iter.count, 0);
438 		KUNIT_EXPECT_EQ(test, iter.iov_offset, size);
439 		i += size;
440 	}
441 
442 	/* Build the expected image in the scratch buffer. */
443 	patt = 0;
444 	memset(scratch, 0, bufsize);
445 	for (pr = kvec_test_ranges; pr->from >= 0; pr++)
446 		for (i = pr->from; i < pr->to; i++)
447 			scratch[i] = pattern(patt++);
448 
449 	/* Compare the images */
450 	for (i = 0; i < bufsize; i++) {
451 		KUNIT_EXPECT_EQ_MSG(test, buffer[i], scratch[i], "at i=%x", i);
452 		if (buffer[i] != scratch[i])
453 			return;
454 	}
455 
456 	KUNIT_SUCCEED();
457 }
458 
459 /*
460  * Test copying from a ITER_XARRAY-type iterator.
461  */
462 static void __init iov_kunit_copy_from_xarray(struct kunit *test)
463 {
464 	const struct kvec_test_range *pr;
465 	struct iov_iter iter;
466 	struct xarray *xarray;
467 	struct page **spages, **bpages;
468 	u8 *scratch, *buffer;
469 	size_t bufsize, npages, size, copied;
470 	int i, j;
471 
472 	bufsize = 0x100000;
473 	npages = bufsize / PAGE_SIZE;
474 
475 	xarray = iov_kunit_create_xarray(test);
476 
477 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
478 	for (i = 0; i < bufsize; i++)
479 		buffer[i] = pattern(i);
480 
481 	scratch = iov_kunit_create_buffer(test, &spages, npages);
482 	memset(scratch, 0, bufsize);
483 
484 	iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
485 
486 	i = 0;
487 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
488 		size = pr->to - pr->from;
489 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
490 
491 		iov_iter_xarray(&iter, WRITE, xarray, pr->from, size);
492 		copied = copy_from_iter(scratch + i, size, &iter);
493 
494 		KUNIT_EXPECT_EQ(test, copied, size);
495 		KUNIT_EXPECT_EQ(test, iter.count, 0);
496 		KUNIT_EXPECT_EQ(test, iter.iov_offset, size);
497 		i += size;
498 	}
499 
500 	/* Build the expected image in the main buffer. */
501 	i = 0;
502 	memset(buffer, 0, bufsize);
503 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
504 		for (j = pr->from; j < pr->to; j++) {
505 			buffer[i++] = pattern(j);
506 			if (i >= bufsize)
507 				goto stop;
508 		}
509 	}
510 stop:
511 
512 	/* Compare the images */
513 	for (i = 0; i < bufsize; i++) {
514 		KUNIT_EXPECT_EQ_MSG(test, scratch[i], buffer[i], "at i=%x", i);
515 		if (scratch[i] != buffer[i])
516 			return;
517 	}
518 
519 	KUNIT_SUCCEED();
520 }
521 
522 /*
523  * Test the extraction of ITER_KVEC-type iterators.
524  */
525 static void __init iov_kunit_extract_pages_kvec(struct kunit *test)
526 {
527 	const struct kvec_test_range *pr;
528 	struct iov_iter iter;
529 	struct page **bpages, *pagelist[8], **pages = pagelist;
530 	struct kvec kvec[8];
531 	u8 *buffer;
532 	ssize_t len;
533 	size_t bufsize, size = 0, npages;
534 	int i, from;
535 
536 	bufsize = 0x100000;
537 	npages = bufsize / PAGE_SIZE;
538 
539 	buffer = iov_kunit_create_buffer(test, &bpages, npages);
540 
541 	iov_kunit_load_kvec(test, &iter, READ, kvec, ARRAY_SIZE(kvec),
542 			    buffer, bufsize, kvec_test_ranges);
543 	size = iter.count;
544 
545 	pr = kvec_test_ranges;
546 	from = pr->from;
547 	do {
548 		size_t offset0 = LONG_MAX;
549 
550 		for (i = 0; i < ARRAY_SIZE(pagelist); i++)
551 			pagelist[i] = (void *)(unsigned long)0xaa55aa55aa55aa55ULL;
552 
553 		len = iov_iter_extract_pages(&iter, &pages, 100 * 1024,
554 					     ARRAY_SIZE(pagelist), 0, &offset0);
555 		KUNIT_EXPECT_GE(test, len, 0);
556 		if (len < 0)
557 			break;
558 		KUNIT_EXPECT_GE(test, (ssize_t)offset0, 0);
559 		KUNIT_EXPECT_LT(test, offset0, PAGE_SIZE);
560 		KUNIT_EXPECT_LE(test, len, size);
561 		KUNIT_EXPECT_EQ(test, iter.count, size - len);
562 		size -= len;
563 
564 		if (len == 0)
565 			break;
566 
567 		for (i = 0; i < ARRAY_SIZE(pagelist); i++) {
568 			struct page *p;
569 			ssize_t part = min_t(ssize_t, len, PAGE_SIZE - offset0);
570 			int ix;
571 
572 			KUNIT_ASSERT_GE(test, part, 0);
573 			while (from == pr->to) {
574 				pr++;
575 				from = pr->from;
576 				if (from < 0)
577 					goto stop;
578 			}
579 			ix = from / PAGE_SIZE;
580 			KUNIT_ASSERT_LT(test, ix, npages);
581 			p = bpages[ix];
582 			KUNIT_EXPECT_PTR_EQ(test, pagelist[i], p);
583 			KUNIT_EXPECT_EQ(test, offset0, from % PAGE_SIZE);
584 			from += part;
585 			len -= part;
586 			KUNIT_ASSERT_GE(test, len, 0);
587 			if (len == 0)
588 				break;
589 			offset0 = 0;
590 		}
591 
592 		if (test->status == KUNIT_FAILURE)
593 			break;
594 	} while (iov_iter_count(&iter) > 0);
595 
596 stop:
597 	KUNIT_EXPECT_EQ(test, size, 0);
598 	KUNIT_EXPECT_EQ(test, iter.count, 0);
599 	KUNIT_SUCCEED();
600 }
601 
602 /*
603  * Test the extraction of ITER_BVEC-type iterators.
604  */
605 static void __init iov_kunit_extract_pages_bvec(struct kunit *test)
606 {
607 	const struct bvec_test_range *pr;
608 	struct iov_iter iter;
609 	struct page **bpages, *pagelist[8], **pages = pagelist;
610 	struct bio_vec bvec[8];
611 	ssize_t len;
612 	size_t bufsize, size = 0, npages;
613 	int i, from;
614 
615 	bufsize = 0x100000;
616 	npages = bufsize / PAGE_SIZE;
617 
618 	iov_kunit_create_buffer(test, &bpages, npages);
619 	iov_kunit_load_bvec(test, &iter, READ, bvec, ARRAY_SIZE(bvec),
620 			    bpages, npages, bufsize, bvec_test_ranges);
621 	size = iter.count;
622 
623 	pr = bvec_test_ranges;
624 	from = pr->from;
625 	do {
626 		size_t offset0 = LONG_MAX;
627 
628 		for (i = 0; i < ARRAY_SIZE(pagelist); i++)
629 			pagelist[i] = (void *)(unsigned long)0xaa55aa55aa55aa55ULL;
630 
631 		len = iov_iter_extract_pages(&iter, &pages, 100 * 1024,
632 					     ARRAY_SIZE(pagelist), 0, &offset0);
633 		KUNIT_EXPECT_GE(test, len, 0);
634 		if (len < 0)
635 			break;
636 		KUNIT_EXPECT_GE(test, (ssize_t)offset0, 0);
637 		KUNIT_EXPECT_LT(test, offset0, PAGE_SIZE);
638 		KUNIT_EXPECT_LE(test, len, size);
639 		KUNIT_EXPECT_EQ(test, iter.count, size - len);
640 		size -= len;
641 
642 		if (len == 0)
643 			break;
644 
645 		for (i = 0; i < ARRAY_SIZE(pagelist); i++) {
646 			struct page *p;
647 			ssize_t part = min_t(ssize_t, len, PAGE_SIZE - offset0);
648 			int ix;
649 
650 			KUNIT_ASSERT_GE(test, part, 0);
651 			while (from == pr->to) {
652 				pr++;
653 				from = pr->from;
654 				if (from < 0)
655 					goto stop;
656 			}
657 			ix = pr->page + from / PAGE_SIZE;
658 			KUNIT_ASSERT_LT(test, ix, npages);
659 			p = bpages[ix];
660 			KUNIT_EXPECT_PTR_EQ(test, pagelist[i], p);
661 			KUNIT_EXPECT_EQ(test, offset0, from % PAGE_SIZE);
662 			from += part;
663 			len -= part;
664 			KUNIT_ASSERT_GE(test, len, 0);
665 			if (len == 0)
666 				break;
667 			offset0 = 0;
668 		}
669 
670 		if (test->status == KUNIT_FAILURE)
671 			break;
672 	} while (iov_iter_count(&iter) > 0);
673 
674 stop:
675 	KUNIT_EXPECT_EQ(test, size, 0);
676 	KUNIT_EXPECT_EQ(test, iter.count, 0);
677 	KUNIT_SUCCEED();
678 }
679 
680 /*
681  * Test the extraction of ITER_XARRAY-type iterators.
682  */
683 static void __init iov_kunit_extract_pages_xarray(struct kunit *test)
684 {
685 	const struct kvec_test_range *pr;
686 	struct iov_iter iter;
687 	struct xarray *xarray;
688 	struct page **bpages, *pagelist[8], **pages = pagelist;
689 	ssize_t len;
690 	size_t bufsize, size = 0, npages;
691 	int i, from;
692 
693 	bufsize = 0x100000;
694 	npages = bufsize / PAGE_SIZE;
695 
696 	xarray = iov_kunit_create_xarray(test);
697 
698 	iov_kunit_create_buffer(test, &bpages, npages);
699 	iov_kunit_load_xarray(test, &iter, READ, xarray, bpages, npages);
700 
701 	for (pr = kvec_test_ranges; pr->from >= 0; pr++) {
702 		from = pr->from;
703 		size = pr->to - from;
704 		KUNIT_ASSERT_LE(test, pr->to, bufsize);
705 
706 		iov_iter_xarray(&iter, WRITE, xarray, from, size);
707 
708 		do {
709 			size_t offset0 = LONG_MAX;
710 
711 			for (i = 0; i < ARRAY_SIZE(pagelist); i++)
712 				pagelist[i] = (void *)(unsigned long)0xaa55aa55aa55aa55ULL;
713 
714 			len = iov_iter_extract_pages(&iter, &pages, 100 * 1024,
715 						     ARRAY_SIZE(pagelist), 0, &offset0);
716 			KUNIT_EXPECT_GE(test, len, 0);
717 			if (len < 0)
718 				break;
719 			KUNIT_EXPECT_LE(test, len, size);
720 			KUNIT_EXPECT_EQ(test, iter.count, size - len);
721 			if (len == 0)
722 				break;
723 			size -= len;
724 			KUNIT_EXPECT_GE(test, (ssize_t)offset0, 0);
725 			KUNIT_EXPECT_LT(test, offset0, PAGE_SIZE);
726 
727 			for (i = 0; i < ARRAY_SIZE(pagelist); i++) {
728 				struct page *p;
729 				ssize_t part = min_t(ssize_t, len, PAGE_SIZE - offset0);
730 				int ix;
731 
732 				KUNIT_ASSERT_GE(test, part, 0);
733 				ix = from / PAGE_SIZE;
734 				KUNIT_ASSERT_LT(test, ix, npages);
735 				p = bpages[ix];
736 				KUNIT_EXPECT_PTR_EQ(test, pagelist[i], p);
737 				KUNIT_EXPECT_EQ(test, offset0, from % PAGE_SIZE);
738 				from += part;
739 				len -= part;
740 				KUNIT_ASSERT_GE(test, len, 0);
741 				if (len == 0)
742 					break;
743 				offset0 = 0;
744 			}
745 
746 			if (test->status == KUNIT_FAILURE)
747 				goto stop;
748 		} while (iov_iter_count(&iter) > 0);
749 
750 		KUNIT_EXPECT_EQ(test, size, 0);
751 		KUNIT_EXPECT_EQ(test, iter.count, 0);
752 		KUNIT_EXPECT_EQ(test, iter.iov_offset, pr->to - pr->from);
753 	}
754 
755 stop:
756 	KUNIT_SUCCEED();
757 }
758 
759 static struct kunit_case __refdata iov_kunit_cases[] = {
760 	KUNIT_CASE(iov_kunit_copy_to_kvec),
761 	KUNIT_CASE(iov_kunit_copy_from_kvec),
762 	KUNIT_CASE(iov_kunit_copy_to_bvec),
763 	KUNIT_CASE(iov_kunit_copy_from_bvec),
764 	KUNIT_CASE(iov_kunit_copy_to_xarray),
765 	KUNIT_CASE(iov_kunit_copy_from_xarray),
766 	KUNIT_CASE(iov_kunit_extract_pages_kvec),
767 	KUNIT_CASE(iov_kunit_extract_pages_bvec),
768 	KUNIT_CASE(iov_kunit_extract_pages_xarray),
769 	{}
770 };
771 
772 static struct kunit_suite iov_kunit_suite = {
773 	.name = "iov_iter",
774 	.test_cases = iov_kunit_cases,
775 };
776 
777 kunit_test_suites(&iov_kunit_suite);
778