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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2017 Oracle. All rights reserved.
4 */
5
6#include <linux/types.h>
7#include "btrfs-tests.h"
8#include "../ctree.h"
9
10static void free_extent_map_tree(struct extent_map_tree *em_tree)
11{
12 struct extent_map *em;
13 struct rb_node *node;
14
15 while (!RB_EMPTY_ROOT(&em_tree->map)) {
16 node = rb_first(&em_tree->map);
17 em = rb_entry(node, struct extent_map, rb_node);
18 remove_extent_mapping(em_tree, em);
19
20#ifdef CONFIG_BTRFS_DEBUG
21 if (refcount_read(&em->refs) != 1) {
22 test_msg(
23"em leak: em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx) refs %d\n",
24 em->start, em->len, em->block_start,
25 em->block_len, refcount_read(&em->refs));
26
27 refcount_set(&em->refs, 1);
28 }
29#endif
30 free_extent_map(em);
31 }
32}
33
34/*
35 * Test scenario:
36 *
37 * Suppose that no extent map has been loaded into memory yet, there is a file
38 * extent [0, 16K), followed by another file extent [16K, 20K), two dio reads
39 * are entering btrfs_get_extent() concurrently, t1 is reading [8K, 16K), t2 is
40 * reading [0, 8K)
41 *
42 * t1 t2
43 * btrfs_get_extent() btrfs_get_extent()
44 * -> lookup_extent_mapping() ->lookup_extent_mapping()
45 * -> add_extent_mapping(0, 16K)
46 * -> return em
47 * ->add_extent_mapping(0, 16K)
48 * -> #handle -EEXIST
49 */
50static void test_case_1(struct extent_map_tree *em_tree)
51{
52 struct extent_map *em;
53 u64 start = 0;
54 u64 len = SZ_8K;
55 int ret;
56
57 em = alloc_extent_map();
58 if (!em)
59 /* Skip the test on error. */
60 return;
61
62 /* Add [0, 16K) */
63 em->start = 0;
64 em->len = SZ_16K;
65 em->block_start = 0;
66 em->block_len = SZ_16K;
67 ret = add_extent_mapping(em_tree, em, 0);
68 ASSERT(ret == 0);
69 free_extent_map(em);
70
71 /* Add [16K, 20K) following [0, 16K) */
72 em = alloc_extent_map();
73 if (!em)
74 goto out;
75
76 em->start = SZ_16K;
77 em->len = SZ_4K;
78 em->block_start = SZ_32K; /* avoid merging */
79 em->block_len = SZ_4K;
80 ret = add_extent_mapping(em_tree, em, 0);
81 ASSERT(ret == 0);
82 free_extent_map(em);
83
84 em = alloc_extent_map();
85 if (!em)
86 goto out;
87
88 /* Add [0, 8K), should return [0, 16K) instead. */
89 em->start = start;
90 em->len = len;
91 em->block_start = start;
92 em->block_len = len;
93 ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
94 if (ret)
95 test_msg("case1 [%llu %llu]: ret %d\n", start, start + len, ret);
96 if (em &&
97 (em->start != 0 || extent_map_end(em) != SZ_16K ||
98 em->block_start != 0 || em->block_len != SZ_16K))
99 test_msg(
100"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n",
101 start, start + len, ret, em->start, em->len,
102 em->block_start, em->block_len);
103 free_extent_map(em);
104out:
105 /* free memory */
106 free_extent_map_tree(em_tree);
107}
108
109/*
110 * Test scenario:
111 *
112 * Reading the inline ending up with EEXIST, ie. read an inline
113 * extent and discard page cache and read it again.
114 */
115static void test_case_2(struct extent_map_tree *em_tree)
116{
117 struct extent_map *em;
118 int ret;
119
120 em = alloc_extent_map();
121 if (!em)
122 /* Skip the test on error. */
123 return;
124
125 /* Add [0, 1K) */
126 em->start = 0;
127 em->len = SZ_1K;
128 em->block_start = EXTENT_MAP_INLINE;
129 em->block_len = (u64)-1;
130 ret = add_extent_mapping(em_tree, em, 0);
131 ASSERT(ret == 0);
132 free_extent_map(em);
133
134 /* Add [4K, 4K) following [0, 1K) */
135 em = alloc_extent_map();
136 if (!em)
137 goto out;
138
139 em->start = SZ_4K;
140 em->len = SZ_4K;
141 em->block_start = SZ_4K;
142 em->block_len = SZ_4K;
143 ret = add_extent_mapping(em_tree, em, 0);
144 ASSERT(ret == 0);
145 free_extent_map(em);
146
147 em = alloc_extent_map();
148 if (!em)
149 goto out;
150
151 /* Add [0, 1K) */
152 em->start = 0;
153 em->len = SZ_1K;
154 em->block_start = EXTENT_MAP_INLINE;
155 em->block_len = (u64)-1;
156 ret = btrfs_add_extent_mapping(em_tree, &em, em->start, em->len);
157 if (ret)
158 test_msg("case2 [0 1K]: ret %d\n", ret);
159 if (em &&
160 (em->start != 0 || extent_map_end(em) != SZ_1K ||
161 em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1))
162 test_msg(
163"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu\n",
164 ret, em->start, em->len, em->block_start,
165 em->block_len);
166 free_extent_map(em);
167out:
168 /* free memory */
169 free_extent_map_tree(em_tree);
170}
171
172static void __test_case_3(struct extent_map_tree *em_tree, u64 start)
173{
174 struct extent_map *em;
175 u64 len = SZ_4K;
176 int ret;
177
178 em = alloc_extent_map();
179 if (!em)
180 /* Skip this test on error. */
181 return;
182
183 /* Add [4K, 8K) */
184 em->start = SZ_4K;
185 em->len = SZ_4K;
186 em->block_start = SZ_4K;
187 em->block_len = SZ_4K;
188 ret = add_extent_mapping(em_tree, em, 0);
189 ASSERT(ret == 0);
190 free_extent_map(em);
191
192 em = alloc_extent_map();
193 if (!em)
194 goto out;
195
196 /* Add [0, 16K) */
197 em->start = 0;
198 em->len = SZ_16K;
199 em->block_start = 0;
200 em->block_len = SZ_16K;
201 ret = btrfs_add_extent_mapping(em_tree, &em, start, len);
202 if (ret)
203 test_msg("case3 [0x%llx 0x%llx): ret %d\n",
204 start, start + len, ret);
205 /*
206 * Since bytes within em are contiguous, em->block_start is identical to
207 * em->start.
208 */
209 if (em &&
210 (start < em->start || start + len > extent_map_end(em) ||
211 em->start != em->block_start || em->len != em->block_len))
212 test_msg(
213"case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n",
214 start, start + len, ret, em->start, em->len,
215 em->block_start, em->block_len);
216 free_extent_map(em);
217out:
218 /* free memory */
219 free_extent_map_tree(em_tree);
220}
221
222/*
223 * Test scenario:
224 *
225 * Suppose that no extent map has been loaded into memory yet.
226 * There is a file extent [0, 16K), two jobs are running concurrently
227 * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio
228 * read from [0, 4K) or [8K, 12K) or [12K, 16K).
229 *
230 * t1 goes ahead of t2 and adds em [4K, 8K) into tree.
231 *
232 * t1 t2
233 * cow_file_range() btrfs_get_extent()
234 * -> lookup_extent_mapping()
235 * -> add_extent_mapping()
236 * -> add_extent_mapping()
237 */
238static void test_case_3(struct extent_map_tree *em_tree)
239{
240 __test_case_3(em_tree, 0);
241 __test_case_3(em_tree, SZ_8K);
242 __test_case_3(em_tree, (12 * 1024ULL));
243}
244
245static void __test_case_4(struct extent_map_tree *em_tree, u64 start)
246{
247 struct extent_map *em;
248 u64 len = SZ_4K;
249 int ret;
250
251 em = alloc_extent_map();
252 if (!em)
253 /* Skip this test on error. */
254 return;
255
256 /* Add [0K, 8K) */
257 em->start = 0;
258 em->len = SZ_8K;
259 em->block_start = 0;
260 em->block_len = SZ_8K;
261 ret = add_extent_mapping(em_tree, em, 0);
262 ASSERT(ret == 0);
263 free_extent_map(em);
264
265 em = alloc_extent_map();
266 if (!em)
267 goto out;
268
269 /* Add [8K, 24K) */
270 em->start = SZ_8K;
271 em->len = 24 * 1024ULL;
272 em->block_start = SZ_16K; /* avoid merging */
273 em->block_len = 24 * 1024ULL;
274 ret = add_extent_mapping(em_tree, em, 0);
275 ASSERT(ret == 0);
276 free_extent_map(em);
277
278 em = alloc_extent_map();
279 if (!em)
280 goto out;
281 /* Add [0K, 32K) */
282 em->start = 0;
283 em->len = SZ_32K;
284 em->block_start = 0;
285 em->block_len = SZ_32K;
286 ret = btrfs_add_extent_mapping(em_tree, &em, start, len);
287 if (ret)
288 test_msg("case4 [0x%llx 0x%llx): ret %d\n",
289 start, len, ret);
290 if (em &&
291 (start < em->start || start + len > extent_map_end(em)))
292 test_msg(
293"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",
294 start, len, ret, em->start, em->len, em->block_start,
295 em->block_len);
296 free_extent_map(em);
297out:
298 /* free memory */
299 free_extent_map_tree(em_tree);
300}
301
302/*
303 * Test scenario:
304 *
305 * Suppose that no extent map has been loaded into memory yet.
306 * There is a file extent [0, 32K), two jobs are running concurrently
307 * against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio
308 * read from [0, 4K) or [4K, 8K).
309 *
310 * t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K).
311 *
312 * t1 t2
313 * btrfs_get_blocks_direct() btrfs_get_blocks_direct()
314 * -> btrfs_get_extent() -> btrfs_get_extent()
315 * -> lookup_extent_mapping()
316 * -> add_extent_mapping() -> lookup_extent_mapping()
317 * # load [0, 32K)
318 * -> btrfs_new_extent_direct()
319 * -> btrfs_drop_extent_cache()
320 * # split [0, 32K)
321 * -> add_extent_mapping()
322 * # add [8K, 32K)
323 * -> add_extent_mapping()
324 * # handle -EEXIST when adding
325 * # [0, 32K)
326 */
327static void test_case_4(struct extent_map_tree *em_tree)
328{
329 __test_case_4(em_tree, 0);
330 __test_case_4(em_tree, SZ_4K);
331}
332
333int btrfs_test_extent_map(void)
334{
335 struct extent_map_tree *em_tree;
336
337 test_msg("Running extent_map tests\n");
338
339 em_tree = kzalloc(sizeof(*em_tree), GFP_KERNEL);
340 if (!em_tree)
341 /* Skip the test on error. */
342 return 0;
343
344 extent_map_tree_init(em_tree);
345
346 test_case_1(em_tree);
347 test_case_2(em_tree);
348 test_case_3(em_tree);
349 test_case_4(em_tree);
350
351 kfree(em_tree);
352 return 0;
353}