1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2013 Fusion IO.  All rights reserved.
4  */
5 
6 #include <linux/pagemap.h>
7 #include <linux/sched.h>
8 #include <linux/slab.h>
9 #include <linux/sizes.h>
10 #include "btrfs-tests.h"
11 #include "../ctree.h"
12 #include "../extent_io.h"
13 #include "../btrfs_inode.h"
14 
15 #define PROCESS_UNLOCK		(1 << 0)
16 #define PROCESS_RELEASE		(1 << 1)
17 #define PROCESS_TEST_LOCKED	(1 << 2)
18 
process_page_range(struct inode * inode,u64 start,u64 end,unsigned long flags)19 static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
20 				       unsigned long flags)
21 {
22 	int ret;
23 	struct page *pages[16];
24 	unsigned long index = start >> PAGE_SHIFT;
25 	unsigned long end_index = end >> PAGE_SHIFT;
26 	unsigned long nr_pages = end_index - index + 1;
27 	int i;
28 	int count = 0;
29 	int loops = 0;
30 
31 	while (nr_pages > 0) {
32 		ret = find_get_pages_contig(inode->i_mapping, index,
33 				     min_t(unsigned long, nr_pages,
34 				     ARRAY_SIZE(pages)), pages);
35 		for (i = 0; i < ret; i++) {
36 			if (flags & PROCESS_TEST_LOCKED &&
37 			    !PageLocked(pages[i]))
38 				count++;
39 			if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
40 				unlock_page(pages[i]);
41 			put_page(pages[i]);
42 			if (flags & PROCESS_RELEASE)
43 				put_page(pages[i]);
44 		}
45 		nr_pages -= ret;
46 		index += ret;
47 		cond_resched();
48 		loops++;
49 		if (loops > 100000) {
50 			printk(KERN_ERR
51 		"stuck in a loop, start %llu, end %llu, nr_pages %lu, ret %d\n",
52 				start, end, nr_pages, ret);
53 			break;
54 		}
55 	}
56 	return count;
57 }
58 
test_find_delalloc(u32 sectorsize)59 static int test_find_delalloc(u32 sectorsize)
60 {
61 	struct inode *inode;
62 	struct extent_io_tree *tmp;
63 	struct page *page;
64 	struct page *locked_page = NULL;
65 	unsigned long index = 0;
66 	/* In this test we need at least 2 file extents at its maximum size */
67 	u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
68 	u64 total_dirty = 2 * max_bytes;
69 	u64 start, end, test_start;
70 	bool found;
71 	int ret = -EINVAL;
72 
73 	test_msg("running find delalloc tests");
74 
75 	inode = btrfs_new_test_inode();
76 	if (!inode) {
77 		test_std_err(TEST_ALLOC_INODE);
78 		return -ENOMEM;
79 	}
80 	tmp = &BTRFS_I(inode)->io_tree;
81 
82 	/*
83 	 * Passing NULL as we don't have fs_info but tracepoints are not used
84 	 * at this point
85 	 */
86 	extent_io_tree_init(NULL, tmp, IO_TREE_SELFTEST, NULL);
87 
88 	/*
89 	 * First go through and create and mark all of our pages dirty, we pin
90 	 * everything to make sure our pages don't get evicted and screw up our
91 	 * test.
92 	 */
93 	for (index = 0; index < (total_dirty >> PAGE_SHIFT); index++) {
94 		page = find_or_create_page(inode->i_mapping, index, GFP_KERNEL);
95 		if (!page) {
96 			test_err("failed to allocate test page");
97 			ret = -ENOMEM;
98 			goto out;
99 		}
100 		SetPageDirty(page);
101 		if (index) {
102 			unlock_page(page);
103 		} else {
104 			get_page(page);
105 			locked_page = page;
106 		}
107 	}
108 
109 	/* Test this scenario
110 	 * |--- delalloc ---|
111 	 * |---  search  ---|
112 	 */
113 	set_extent_delalloc(tmp, 0, sectorsize - 1, 0, NULL);
114 	start = 0;
115 	end = start + PAGE_SIZE - 1;
116 	found = find_lock_delalloc_range(inode, locked_page, &start,
117 					 &end);
118 	if (!found) {
119 		test_err("should have found at least one delalloc");
120 		goto out_bits;
121 	}
122 	if (start != 0 || end != (sectorsize - 1)) {
123 		test_err("expected start 0 end %u, got start %llu end %llu",
124 			sectorsize - 1, start, end);
125 		goto out_bits;
126 	}
127 	unlock_extent(tmp, start, end);
128 	unlock_page(locked_page);
129 	put_page(locked_page);
130 
131 	/*
132 	 * Test this scenario
133 	 *
134 	 * |--- delalloc ---|
135 	 *           |--- search ---|
136 	 */
137 	test_start = SZ_64M;
138 	locked_page = find_lock_page(inode->i_mapping,
139 				     test_start >> PAGE_SHIFT);
140 	if (!locked_page) {
141 		test_err("couldn't find the locked page");
142 		goto out_bits;
143 	}
144 	set_extent_delalloc(tmp, sectorsize, max_bytes - 1, 0, NULL);
145 	start = test_start;
146 	end = start + PAGE_SIZE - 1;
147 	found = find_lock_delalloc_range(inode, locked_page, &start,
148 					 &end);
149 	if (!found) {
150 		test_err("couldn't find delalloc in our range");
151 		goto out_bits;
152 	}
153 	if (start != test_start || end != max_bytes - 1) {
154 		test_err("expected start %llu end %llu, got start %llu, end %llu",
155 				test_start, max_bytes - 1, start, end);
156 		goto out_bits;
157 	}
158 	if (process_page_range(inode, start, end,
159 			       PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
160 		test_err("there were unlocked pages in the range");
161 		goto out_bits;
162 	}
163 	unlock_extent(tmp, start, end);
164 	/* locked_page was unlocked above */
165 	put_page(locked_page);
166 
167 	/*
168 	 * Test this scenario
169 	 * |--- delalloc ---|
170 	 *                    |--- search ---|
171 	 */
172 	test_start = max_bytes + sectorsize;
173 	locked_page = find_lock_page(inode->i_mapping, test_start >>
174 				     PAGE_SHIFT);
175 	if (!locked_page) {
176 		test_err("couldn't find the locked page");
177 		goto out_bits;
178 	}
179 	start = test_start;
180 	end = start + PAGE_SIZE - 1;
181 	found = find_lock_delalloc_range(inode, locked_page, &start,
182 					 &end);
183 	if (found) {
184 		test_err("found range when we shouldn't have");
185 		goto out_bits;
186 	}
187 	if (end != test_start + PAGE_SIZE - 1) {
188 		test_err("did not return the proper end offset");
189 		goto out_bits;
190 	}
191 
192 	/*
193 	 * Test this scenario
194 	 * [------- delalloc -------|
195 	 * [max_bytes]|-- search--|
196 	 *
197 	 * We are re-using our test_start from above since it works out well.
198 	 */
199 	set_extent_delalloc(tmp, max_bytes, total_dirty - 1, 0, NULL);
200 	start = test_start;
201 	end = start + PAGE_SIZE - 1;
202 	found = find_lock_delalloc_range(inode, locked_page, &start,
203 					 &end);
204 	if (!found) {
205 		test_err("didn't find our range");
206 		goto out_bits;
207 	}
208 	if (start != test_start || end != total_dirty - 1) {
209 		test_err("expected start %llu end %llu, got start %llu end %llu",
210 			 test_start, total_dirty - 1, start, end);
211 		goto out_bits;
212 	}
213 	if (process_page_range(inode, start, end,
214 			       PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
215 		test_err("pages in range were not all locked");
216 		goto out_bits;
217 	}
218 	unlock_extent(tmp, start, end);
219 
220 	/*
221 	 * Now to test where we run into a page that is no longer dirty in the
222 	 * range we want to find.
223 	 */
224 	page = find_get_page(inode->i_mapping,
225 			     (max_bytes + SZ_1M) >> PAGE_SHIFT);
226 	if (!page) {
227 		test_err("couldn't find our page");
228 		goto out_bits;
229 	}
230 	ClearPageDirty(page);
231 	put_page(page);
232 
233 	/* We unlocked it in the previous test */
234 	lock_page(locked_page);
235 	start = test_start;
236 	end = start + PAGE_SIZE - 1;
237 	/*
238 	 * Currently if we fail to find dirty pages in the delalloc range we
239 	 * will adjust max_bytes down to PAGE_SIZE and then re-search.  If
240 	 * this changes at any point in the future we will need to fix this
241 	 * tests expected behavior.
242 	 */
243 	found = find_lock_delalloc_range(inode, locked_page, &start,
244 					 &end);
245 	if (!found) {
246 		test_err("didn't find our range");
247 		goto out_bits;
248 	}
249 	if (start != test_start && end != test_start + PAGE_SIZE - 1) {
250 		test_err("expected start %llu end %llu, got start %llu end %llu",
251 			 test_start, test_start + PAGE_SIZE - 1, start, end);
252 		goto out_bits;
253 	}
254 	if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED |
255 			       PROCESS_UNLOCK)) {
256 		test_err("pages in range were not all locked");
257 		goto out_bits;
258 	}
259 	ret = 0;
260 out_bits:
261 	clear_extent_bits(tmp, 0, total_dirty - 1, (unsigned)-1);
262 out:
263 	if (locked_page)
264 		put_page(locked_page);
265 	process_page_range(inode, 0, total_dirty - 1,
266 			   PROCESS_UNLOCK | PROCESS_RELEASE);
267 	iput(inode);
268 	return ret;
269 }
270 
check_eb_bitmap(unsigned long * bitmap,struct extent_buffer * eb,unsigned long len)271 static int check_eb_bitmap(unsigned long *bitmap, struct extent_buffer *eb,
272 			   unsigned long len)
273 {
274 	unsigned long i;
275 
276 	for (i = 0; i < len * BITS_PER_BYTE; i++) {
277 		int bit, bit1;
278 
279 		bit = !!test_bit(i, bitmap);
280 		bit1 = !!extent_buffer_test_bit(eb, 0, i);
281 		if (bit1 != bit) {
282 			test_err("bits do not match");
283 			return -EINVAL;
284 		}
285 
286 		bit1 = !!extent_buffer_test_bit(eb, i / BITS_PER_BYTE,
287 						i % BITS_PER_BYTE);
288 		if (bit1 != bit) {
289 			test_err("offset bits do not match");
290 			return -EINVAL;
291 		}
292 	}
293 	return 0;
294 }
295 
__test_eb_bitmaps(unsigned long * bitmap,struct extent_buffer * eb,unsigned long len)296 static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb,
297 			     unsigned long len)
298 {
299 	unsigned long i, j;
300 	u32 x;
301 	int ret;
302 
303 	memset(bitmap, 0, len);
304 	memzero_extent_buffer(eb, 0, len);
305 	if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
306 		test_err("bitmap was not zeroed");
307 		return -EINVAL;
308 	}
309 
310 	bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
311 	extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
312 	ret = check_eb_bitmap(bitmap, eb, len);
313 	if (ret) {
314 		test_err("setting all bits failed");
315 		return ret;
316 	}
317 
318 	bitmap_clear(bitmap, 0, len * BITS_PER_BYTE);
319 	extent_buffer_bitmap_clear(eb, 0, 0, len * BITS_PER_BYTE);
320 	ret = check_eb_bitmap(bitmap, eb, len);
321 	if (ret) {
322 		test_err("clearing all bits failed");
323 		return ret;
324 	}
325 
326 	/* Straddling pages test */
327 	if (len > PAGE_SIZE) {
328 		bitmap_set(bitmap,
329 			(PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
330 			sizeof(long) * BITS_PER_BYTE);
331 		extent_buffer_bitmap_set(eb, PAGE_SIZE - sizeof(long) / 2, 0,
332 					sizeof(long) * BITS_PER_BYTE);
333 		ret = check_eb_bitmap(bitmap, eb, len);
334 		if (ret) {
335 			test_err("setting straddling pages failed");
336 			return ret;
337 		}
338 
339 		bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
340 		bitmap_clear(bitmap,
341 			(PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
342 			sizeof(long) * BITS_PER_BYTE);
343 		extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
344 		extent_buffer_bitmap_clear(eb, PAGE_SIZE - sizeof(long) / 2, 0,
345 					sizeof(long) * BITS_PER_BYTE);
346 		ret = check_eb_bitmap(bitmap, eb, len);
347 		if (ret) {
348 			test_err("clearing straddling pages failed");
349 			return ret;
350 		}
351 	}
352 
353 	/*
354 	 * Generate a wonky pseudo-random bit pattern for the sake of not using
355 	 * something repetitive that could miss some hypothetical off-by-n bug.
356 	 */
357 	x = 0;
358 	bitmap_clear(bitmap, 0, len * BITS_PER_BYTE);
359 	extent_buffer_bitmap_clear(eb, 0, 0, len * BITS_PER_BYTE);
360 	for (i = 0; i < len * BITS_PER_BYTE / 32; i++) {
361 		x = (0x19660dULL * (u64)x + 0x3c6ef35fULL) & 0xffffffffU;
362 		for (j = 0; j < 32; j++) {
363 			if (x & (1U << j)) {
364 				bitmap_set(bitmap, i * 32 + j, 1);
365 				extent_buffer_bitmap_set(eb, 0, i * 32 + j, 1);
366 			}
367 		}
368 	}
369 
370 	ret = check_eb_bitmap(bitmap, eb, len);
371 	if (ret) {
372 		test_err("random bit pattern failed");
373 		return ret;
374 	}
375 
376 	return 0;
377 }
378 
test_eb_bitmaps(u32 sectorsize,u32 nodesize)379 static int test_eb_bitmaps(u32 sectorsize, u32 nodesize)
380 {
381 	struct btrfs_fs_info *fs_info;
382 	unsigned long *bitmap = NULL;
383 	struct extent_buffer *eb = NULL;
384 	int ret;
385 
386 	test_msg("running extent buffer bitmap tests");
387 
388 	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
389 	if (!fs_info) {
390 		test_std_err(TEST_ALLOC_FS_INFO);
391 		return -ENOMEM;
392 	}
393 
394 	bitmap = kmalloc(nodesize, GFP_KERNEL);
395 	if (!bitmap) {
396 		test_err("couldn't allocate test bitmap");
397 		ret = -ENOMEM;
398 		goto out;
399 	}
400 
401 	eb = __alloc_dummy_extent_buffer(fs_info, 0, nodesize);
402 	if (!eb) {
403 		test_std_err(TEST_ALLOC_ROOT);
404 		ret = -ENOMEM;
405 		goto out;
406 	}
407 
408 	ret = __test_eb_bitmaps(bitmap, eb, nodesize);
409 	if (ret)
410 		goto out;
411 
412 	free_extent_buffer(eb);
413 
414 	/*
415 	 * Test again for case where the tree block is sectorsize aligned but
416 	 * not nodesize aligned.
417 	 */
418 	eb = __alloc_dummy_extent_buffer(fs_info, sectorsize, nodesize);
419 	if (!eb) {
420 		test_std_err(TEST_ALLOC_ROOT);
421 		ret = -ENOMEM;
422 		goto out;
423 	}
424 
425 	ret = __test_eb_bitmaps(bitmap, eb, nodesize);
426 out:
427 	free_extent_buffer(eb);
428 	kfree(bitmap);
429 	btrfs_free_dummy_fs_info(fs_info);
430 	return ret;
431 }
432 
test_find_first_clear_extent_bit(void)433 static int test_find_first_clear_extent_bit(void)
434 {
435 	struct extent_io_tree tree;
436 	u64 start, end;
437 	int ret = -EINVAL;
438 
439 	test_msg("running find_first_clear_extent_bit test");
440 
441 	extent_io_tree_init(NULL, &tree, IO_TREE_SELFTEST, NULL);
442 
443 	/* Test correct handling of empty tree */
444 	find_first_clear_extent_bit(&tree, 0, &start, &end, CHUNK_TRIMMED);
445 	if (start != 0 || end != -1) {
446 		test_err(
447 	"error getting a range from completely empty tree: start %llu end %llu",
448 			 start, end);
449 		goto out;
450 	}
451 	/*
452 	 * Set 1M-4M alloc/discard and 32M-64M thus leaving a hole between
453 	 * 4M-32M
454 	 */
455 	set_extent_bits(&tree, SZ_1M, SZ_4M - 1,
456 			CHUNK_TRIMMED | CHUNK_ALLOCATED);
457 
458 	find_first_clear_extent_bit(&tree, SZ_512K, &start, &end,
459 				    CHUNK_TRIMMED | CHUNK_ALLOCATED);
460 
461 	if (start != 0 || end != SZ_1M - 1) {
462 		test_err("error finding beginning range: start %llu end %llu",
463 			 start, end);
464 		goto out;
465 	}
466 
467 	/* Now add 32M-64M so that we have a hole between 4M-32M */
468 	set_extent_bits(&tree, SZ_32M, SZ_64M - 1,
469 			CHUNK_TRIMMED | CHUNK_ALLOCATED);
470 
471 	/*
472 	 * Request first hole starting at 12M, we should get 4M-32M
473 	 */
474 	find_first_clear_extent_bit(&tree, 12 * SZ_1M, &start, &end,
475 				    CHUNK_TRIMMED | CHUNK_ALLOCATED);
476 
477 	if (start != SZ_4M || end != SZ_32M - 1) {
478 		test_err("error finding trimmed range: start %llu end %llu",
479 			 start, end);
480 		goto out;
481 	}
482 
483 	/*
484 	 * Search in the middle of allocated range, should get the next one
485 	 * available, which happens to be unallocated -> 4M-32M
486 	 */
487 	find_first_clear_extent_bit(&tree, SZ_2M, &start, &end,
488 				    CHUNK_TRIMMED | CHUNK_ALLOCATED);
489 
490 	if (start != SZ_4M || end != SZ_32M - 1) {
491 		test_err("error finding next unalloc range: start %llu end %llu",
492 			 start, end);
493 		goto out;
494 	}
495 
496 	/*
497 	 * Set 64M-72M with CHUNK_ALLOC flag, then search for CHUNK_TRIMMED flag
498 	 * being unset in this range, we should get the entry in range 64M-72M
499 	 */
500 	set_extent_bits(&tree, SZ_64M, SZ_64M + SZ_8M - 1, CHUNK_ALLOCATED);
501 	find_first_clear_extent_bit(&tree, SZ_64M + SZ_1M, &start, &end,
502 				    CHUNK_TRIMMED);
503 
504 	if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
505 		test_err("error finding exact range: start %llu end %llu",
506 			 start, end);
507 		goto out;
508 	}
509 
510 	find_first_clear_extent_bit(&tree, SZ_64M - SZ_8M, &start, &end,
511 				    CHUNK_TRIMMED);
512 
513 	/*
514 	 * Search in the middle of set range whose immediate neighbour doesn't
515 	 * have the bits set so it must be returned
516 	 */
517 	if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
518 		test_err("error finding next alloc range: start %llu end %llu",
519 			 start, end);
520 		goto out;
521 	}
522 
523 	/*
524 	 * Search beyond any known range, shall return after last known range
525 	 * and end should be -1
526 	 */
527 	find_first_clear_extent_bit(&tree, -1, &start, &end, CHUNK_TRIMMED);
528 	if (start != SZ_64M + SZ_8M || end != -1) {
529 		test_err(
530 		"error handling beyond end of range search: start %llu end %llu",
531 			start, end);
532 		goto out;
533 	}
534 
535 	ret = 0;
536 out:
537 	clear_extent_bits(&tree, 0, (u64)-1, CHUNK_TRIMMED | CHUNK_ALLOCATED);
538 
539 	return ret;
540 }
541 
btrfs_test_extent_io(u32 sectorsize,u32 nodesize)542 int btrfs_test_extent_io(u32 sectorsize, u32 nodesize)
543 {
544 	int ret;
545 
546 	test_msg("running extent I/O tests");
547 
548 	ret = test_find_delalloc(sectorsize);
549 	if (ret)
550 		goto out;
551 
552 	ret = test_find_first_clear_extent_bit();
553 	if (ret)
554 		goto out;
555 
556 	ret = test_eb_bitmaps(sectorsize, nodesize);
557 out:
558 	return ret;
559 }
560