summaryrefslogtreecommitdiff
path: root/fs/btrfs/tests/extent-map-tests.c
blob: 79e0a5f4d9c9a591e02f0a9854e9b09721170ffc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 Oracle.  All rights reserved.
 */

#include <linux/types.h>
#include "btrfs-tests.h"
#include "../ctree.h"

static void free_extent_map_tree(struct extent_map_tree *em_tree)
{
	struct extent_map *em;
	struct rb_node *node;

	while (!RB_EMPTY_ROOT(&em_tree->map)) {
		node = rb_first(&em_tree->map);
		em = rb_entry(node, struct extent_map, rb_node);
		remove_extent_mapping(em_tree, em);

#ifdef CONFIG_BTRFS_DEBUG
		if (refcount_read(&em->refs) != 1) {
			test_msg(
"em leak: em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx) refs %d\n",
				 em->start, em->len, em->block_start,
				 em->block_len, refcount_read(&em->refs));

			refcount_set(&em->refs, 1);
		}
#endif
		free_extent_map(em);
	}
}

/*
 * Test scenario:
 *
 * Suppose that no extent map has been loaded into memory yet, there is a file
 * extent [0, 16K), followed by another file extent [16K, 20K), two dio reads
 * are entering btrfs_get_extent() concurrently, t1 is reading [8K, 16K), t2 is
 * reading [0, 8K)
 *
 *     t1                            t2
 *  btrfs_get_extent()              btrfs_get_extent()
 *    -> lookup_extent_mapping()      ->lookup_extent_mapping()
 *    -> add_extent_mapping(0, 16K)
 *    -> return em
 *                                    ->add_extent_mapping(0, 16K)
 *                                    -> #handle -EEXIST
 */
static void test_case_1(struct extent_map_tree *em_tree)
{
	struct extent_map *em;
	u64 start = 0;
	u64 len = SZ_8K;
	int ret;

	em = alloc_extent_map();
	if (!em)
		/* Skip the test on error. */
		return;

	/* Add [0, 16K) */
	em->start = 0;
	em->len = SZ_16K;
	em->block_start = 0;
	em->block_len = SZ_16K;
	ret = add_extent_mapping(em_tree, em, 0);
	ASSERT(ret == 0);
	free_extent_map(em);

	/* Add [16K, 20K) following [0, 16K)  */
	em = alloc_extent_map();
	if (!em)
		goto out;

	em->start = SZ_16K;
	em->len = SZ_4K;
	em->block_start = SZ_32K; /* avoid merging */
	em->block_len = SZ_4K;
	ret = add_extent_mapping(em_tree, em, 0);
	ASSERT(ret == 0);
	free_extent_map(em);

	em = alloc_extent_map();
	if (!em)
		goto out;

	/* Add [0, 8K), should return [0, 16K) instead. */
	em->start = start;
	em->len = len;
	em->block_start = start;
	em->block_len = len;
	ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
	if (ret)
		test_msg("case1 [%llu %llu]: ret %d\n", start, start + len, ret);
	if (em &&
	    (em->start != 0 || extent_map_end(em) != SZ_16K ||
	     em->block_start != 0 || em->block_len != SZ_16K))
		test_msg(
"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n",
			 start, start + len, ret, em->start, em->len,
			 em->block_start, em->block_len);
	free_extent_map(em);
out:
	/* free memory */
	free_extent_map_tree(em_tree);
}

/*
 * Test scenario:
 *
 * Reading the inline ending up with EEXIST, ie. read an inline
 * extent and discard page cache and read it again.
 */
static void test_case_2(struct extent_map_tree *em_tree)
{
	struct extent_map *em;
	int ret;

	em = alloc_extent_map();
	if (!em)
		/* Skip the test on error. */
		return;

	/* Add [0, 1K) */
	em->start = 0;
	em->len = SZ_1K;
	em->block_start = EXTENT_MAP_INLINE;
	em->block_len = (u64)-1;
	ret = add_extent_mapping(em_tree, em, 0);
	ASSERT(ret == 0);
	free_extent_map(em);

	/* Add [4K, 4K) following [0, 1K)  */
	em = alloc_extent_map();
	if (!em)
		goto out;

	em->start = SZ_4K;
	em->len = SZ_4K;
	em->block_start = SZ_4K;
	em->block_len = SZ_4K;
	ret = add_extent_mapping(em_tree, em, 0);
	ASSERT(ret == 0);
	free_extent_map(em);

	em = alloc_extent_map();
	if (!em)
		goto out;

	/* Add [0, 1K) */
	em->start = 0;
	em->len = SZ_1K;
	em->block_start = EXTENT_MAP_INLINE;
	em->block_len = (u64)-1;
	ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
	if (ret)
		test_msg("case2 [0 1K]: ret %d\n", ret);
	if (em &&
	    (em->start != 0 || extent_map_end(em) != SZ_1K ||
	     em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1))
		test_msg(
"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n",
			 ret, em->start, em->len, em->block_start,
			 em->block_len);
	free_extent_map(em);
out:
	/* free memory */
	free_extent_map_tree(em_tree);
}

static void __test_case_3(struct extent_map_tree *em_tree, u64 start)
{
	struct extent_map *em;
	u64 len = SZ_4K;
	int ret;

	em = alloc_extent_map();
	if (!em)
		/* Skip this test on error. */
		return;

	/* Add [4K, 8K) */
	em->start = SZ_4K;
	em->len = SZ_4K;
	em->block_start = SZ_4K;
	em->block_len = SZ_4K;
	ret = add_extent_mapping(em_tree, em, 0);
	ASSERT(ret == 0);
	free_extent_map(em);

	em = alloc_extent_map();
	if (!em)
		goto out;

	/* Add [0, 16K) */
	em->start = 0;
	em->len = SZ_16K;
	em->block_start = 0;
	em->block_len = SZ_16K;
	ret = btrfs_add_extent_mapping(em_tree, &em, start, len);
	if (ret)
		test_msg("case3 [0x%llx 0x%llx): ret %d\n",
			 start, start + len, ret);
	/*
	 * Since bytes within em are contiguous, em->block_start is identical to
	 * em->start.
	 */
	if (em &&
	    (start < em->start || start + len > extent_map_end(em) ||
	     em->start != em->block_start || em->len != em->block_len))
		test_msg(
"case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n",
			 start, start + len, ret, em->start, em->len,
			 em->block_start, em->block_len);
	free_extent_map(em);
out:
	/* free memory */
	free_extent_map_tree(em_tree);
}

/*
 * Test scenario:
 *
 * Suppose that no extent map has been loaded into memory yet.
 * There is a file extent [0, 16K), two jobs are running concurrently
 * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio
 * read from [0, 4K) or [8K, 12K) or [12K, 16K).
 *
 * t1 goes ahead of t2 and adds em [4K, 8K) into tree.
 *
 *         t1                       t2
 *  cow_file_range()	     btrfs_get_extent()
 *                            -> lookup_extent_mapping()
 *   -> add_extent_mapping()
 *                            -> add_extent_mapping()
 */
static void test_case_3(struct extent_map_tree *em_tree)
{
	__test_case_3(em_tree, 0);
	__test_case_3(em_tree, SZ_8K);
	__test_case_3(em_tree, (12 * 1024ULL));
}

static void __test_case_4(struct extent_map_tree *em_tree, u64 start)
{
	struct extent_map *em;
	u64 len = SZ_4K;
	int ret;

	em = alloc_extent_map();
	if (!em)
		/* Skip this test on error. */
		return;

	/* Add [0K, 8K) */
	em->start = 0;
	em->len = SZ_8K;
	em->block_start = 0;
	em->block_len = SZ_8K;
	ret = add_extent_mapping(em_tree, em, 0);
	ASSERT(ret == 0);
	free_extent_map(em);

	em = alloc_extent_map();
	if (!em)
		goto out;

	/* Add [8K, 24K) */
	em->start = SZ_8K;
	em->len = 24 * 1024ULL;
	em->block_start = SZ_16K; /* avoid merging */
	em->block_len = 24 * 1024ULL;
	ret = add_extent_mapping(em_tree, em, 0);
	ASSERT(ret == 0);
	free_extent_map(em);

	em = alloc_extent_map();
	if (!em)
		goto out;
	/* Add [0K, 32K) */
	em->start = 0;
	em->len = SZ_32K;
	em->block_start = 0;
	em->block_len = SZ_32K;
	ret = btrfs_add_extent_mapping(em_tree, &em, start, len);
	if (ret)
		test_msg("case4 [0x%llx 0x%llx): ret %d\n",
			 start, len, ret);
	if (em &&
	    (start < em->start || start + len > extent_map_end(em)))
		test_msg(
"case4 [0x%llx 0x%llx): ret %d, added wrong em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n",
			 start, len, ret, em->start, em->len, em->block_start,
			 em->block_len);
	free_extent_map(em);
out:
	/* free memory */
	free_extent_map_tree(em_tree);
}

/*
 * Test scenario:
 *
 * Suppose that no extent map has been loaded into memory yet.
 * There is a file extent [0, 32K), two jobs are running concurrently
 * against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio
 * read from [0, 4K) or [4K, 8K).
 *
 * t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K).
 *
 *         t1                                t2
 *  btrfs_get_blocks_direct()	       btrfs_get_blocks_direct()
 *   -> btrfs_get_extent()              -> btrfs_get_extent()
 *       -> lookup_extent_mapping()
 *       -> add_extent_mapping()            -> lookup_extent_mapping()
 *          # load [0, 32K)
 *   -> btrfs_new_extent_direct()
 *       -> btrfs_drop_extent_cache()
 *          # split [0, 32K)
 *       -> add_extent_mapping()
 *          # add [8K, 32K)
 *                                          -> add_extent_mapping()
 *                                             # handle -EEXIST when adding
 *                                             # [0, 32K)
 */
static void test_case_4(struct extent_map_tree *em_tree)
{
	__test_case_4(em_tree, 0);
	__test_case_4(em_tree, SZ_4K);
}

int btrfs_test_extent_map(void)
{
	struct extent_map_tree *em_tree;

	test_msg("Running extent_map tests\n");

	em_tree = kzalloc(sizeof(*em_tree), GFP_KERNEL);
	if (!em_tree)
		/* Skip the test on error. */
		return 0;

	extent_map_tree_init(em_tree);

	test_case_1(em_tree);
	test_case_2(em_tree);
	test_case_3(em_tree);
	test_case_4(em_tree);

	kfree(em_tree);
	return 0;
}