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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.rb_root)) {
16 node = rb_first_cached(&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_err(
23"em leak: em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx) refs %d",
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 int test_case_1(struct btrfs_fs_info *fs_info,
51 struct extent_map_tree *em_tree)
52{
53 struct extent_map *em;
54 u64 start = 0;
55 u64 len = SZ_8K;
56 int ret;
57
58 em = alloc_extent_map();
59 if (!em) {
60 test_std_err(TEST_ALLOC_EXTENT_MAP);
61 return -ENOMEM;
62 }
63
64 /* Add [0, 16K) */
65 em->start = 0;
66 em->len = SZ_16K;
67 em->block_start = 0;
68 em->block_len = SZ_16K;
69 write_lock(&em_tree->lock);
70 ret = add_extent_mapping(em_tree, em, 0);
71 write_unlock(&em_tree->lock);
72 if (ret < 0) {
73 test_err("cannot add extent range [0, 16K)");
74 goto out;
75 }
76 free_extent_map(em);
77
78 /* Add [16K, 20K) following [0, 16K) */
79 em = alloc_extent_map();
80 if (!em) {
81 test_std_err(TEST_ALLOC_EXTENT_MAP);
82 ret = -ENOMEM;
83 goto out;
84 }
85
86 em->start = SZ_16K;
87 em->len = SZ_4K;
88 em->block_start = SZ_32K; /* avoid merging */
89 em->block_len = SZ_4K;
90 write_lock(&em_tree->lock);
91 ret = add_extent_mapping(em_tree, em, 0);
92 write_unlock(&em_tree->lock);
93 if (ret < 0) {
94 test_err("cannot add extent range [16K, 20K)");
95 goto out;
96 }
97 free_extent_map(em);
98
99 em = alloc_extent_map();
100 if (!em) {
101 test_std_err(TEST_ALLOC_EXTENT_MAP);
102 ret = -ENOMEM;
103 goto out;
104 }
105
106 /* Add [0, 8K), should return [0, 16K) instead. */
107 em->start = start;
108 em->len = len;
109 em->block_start = start;
110 em->block_len = len;
111 write_lock(&em_tree->lock);
112 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len);
113 write_unlock(&em_tree->lock);
114 if (ret) {
115 test_err("case1 [%llu %llu]: ret %d", start, start + len, ret);
116 goto out;
117 }
118 if (em &&
119 (em->start != 0 || extent_map_end(em) != SZ_16K ||
120 em->block_start != 0 || em->block_len != SZ_16K)) {
121 test_err(
122"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu",
123 start, start + len, ret, em->start, em->len,
124 em->block_start, em->block_len);
125 ret = -EINVAL;
126 }
127 free_extent_map(em);
128out:
129 free_extent_map_tree(em_tree);
130
131 return ret;
132}
133
134/*
135 * Test scenario:
136 *
137 * Reading the inline ending up with EEXIST, ie. read an inline
138 * extent and discard page cache and read it again.
139 */
140static int test_case_2(struct btrfs_fs_info *fs_info,
141 struct extent_map_tree *em_tree)
142{
143 struct extent_map *em;
144 int ret;
145
146 em = alloc_extent_map();
147 if (!em) {
148 test_std_err(TEST_ALLOC_EXTENT_MAP);
149 return -ENOMEM;
150 }
151
152 /* Add [0, 1K) */
153 em->start = 0;
154 em->len = SZ_1K;
155 em->block_start = EXTENT_MAP_INLINE;
156 em->block_len = (u64)-1;
157 write_lock(&em_tree->lock);
158 ret = add_extent_mapping(em_tree, em, 0);
159 write_unlock(&em_tree->lock);
160 if (ret < 0) {
161 test_err("cannot add extent range [0, 1K)");
162 goto out;
163 }
164 free_extent_map(em);
165
166 /* Add [4K, 8K) following [0, 1K) */
167 em = alloc_extent_map();
168 if (!em) {
169 test_std_err(TEST_ALLOC_EXTENT_MAP);
170 ret = -ENOMEM;
171 goto out;
172 }
173
174 em->start = SZ_4K;
175 em->len = SZ_4K;
176 em->block_start = SZ_4K;
177 em->block_len = SZ_4K;
178 write_lock(&em_tree->lock);
179 ret = add_extent_mapping(em_tree, em, 0);
180 write_unlock(&em_tree->lock);
181 if (ret < 0) {
182 test_err("cannot add extent range [4K, 8K)");
183 goto out;
184 }
185 free_extent_map(em);
186
187 em = alloc_extent_map();
188 if (!em) {
189 test_std_err(TEST_ALLOC_EXTENT_MAP);
190 ret = -ENOMEM;
191 goto out;
192 }
193
194 /* Add [0, 1K) */
195 em->start = 0;
196 em->len = SZ_1K;
197 em->block_start = EXTENT_MAP_INLINE;
198 em->block_len = (u64)-1;
199 write_lock(&em_tree->lock);
200 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len);
201 write_unlock(&em_tree->lock);
202 if (ret) {
203 test_err("case2 [0 1K]: ret %d", ret);
204 goto out;
205 }
206 if (em &&
207 (em->start != 0 || extent_map_end(em) != SZ_1K ||
208 em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1)) {
209 test_err(
210"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu",
211 ret, em->start, em->len, em->block_start,
212 em->block_len);
213 ret = -EINVAL;
214 }
215 free_extent_map(em);
216out:
217 free_extent_map_tree(em_tree);
218
219 return ret;
220}
221
222static int __test_case_3(struct btrfs_fs_info *fs_info,
223 struct extent_map_tree *em_tree, u64 start)
224{
225 struct extent_map *em;
226 u64 len = SZ_4K;
227 int ret;
228
229 em = alloc_extent_map();
230 if (!em) {
231 test_std_err(TEST_ALLOC_EXTENT_MAP);
232 return -ENOMEM;
233 }
234
235 /* Add [4K, 8K) */
236 em->start = SZ_4K;
237 em->len = SZ_4K;
238 em->block_start = SZ_4K;
239 em->block_len = SZ_4K;
240 write_lock(&em_tree->lock);
241 ret = add_extent_mapping(em_tree, em, 0);
242 write_unlock(&em_tree->lock);
243 if (ret < 0) {
244 test_err("cannot add extent range [4K, 8K)");
245 goto out;
246 }
247 free_extent_map(em);
248
249 em = alloc_extent_map();
250 if (!em) {
251 test_std_err(TEST_ALLOC_EXTENT_MAP);
252 ret = -ENOMEM;
253 goto out;
254 }
255
256 /* Add [0, 16K) */
257 em->start = 0;
258 em->len = SZ_16K;
259 em->block_start = 0;
260 em->block_len = SZ_16K;
261 write_lock(&em_tree->lock);
262 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
263 write_unlock(&em_tree->lock);
264 if (ret) {
265 test_err("case3 [0x%llx 0x%llx): ret %d",
266 start, start + len, ret);
267 goto out;
268 }
269 /*
270 * Since bytes within em are contiguous, em->block_start is identical to
271 * em->start.
272 */
273 if (em &&
274 (start < em->start || start + len > extent_map_end(em) ||
275 em->start != em->block_start || em->len != em->block_len)) {
276 test_err(
277"case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)",
278 start, start + len, ret, em->start, em->len,
279 em->block_start, em->block_len);
280 ret = -EINVAL;
281 }
282 free_extent_map(em);
283out:
284 free_extent_map_tree(em_tree);
285
286 return ret;
287}
288
289/*
290 * Test scenario:
291 *
292 * Suppose that no extent map has been loaded into memory yet.
293 * There is a file extent [0, 16K), two jobs are running concurrently
294 * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio
295 * read from [0, 4K) or [8K, 12K) or [12K, 16K).
296 *
297 * t1 goes ahead of t2 and adds em [4K, 8K) into tree.
298 *
299 * t1 t2
300 * cow_file_range() btrfs_get_extent()
301 * -> lookup_extent_mapping()
302 * -> add_extent_mapping()
303 * -> add_extent_mapping()
304 */
305static int test_case_3(struct btrfs_fs_info *fs_info,
306 struct extent_map_tree *em_tree)
307{
308 int ret;
309
310 ret = __test_case_3(fs_info, em_tree, 0);
311 if (ret)
312 return ret;
313 ret = __test_case_3(fs_info, em_tree, SZ_8K);
314 if (ret)
315 return ret;
316 ret = __test_case_3(fs_info, em_tree, (12 * SZ_1K));
317
318 return ret;
319}
320
321static int __test_case_4(struct btrfs_fs_info *fs_info,
322 struct extent_map_tree *em_tree, u64 start)
323{
324 struct extent_map *em;
325 u64 len = SZ_4K;
326 int ret;
327
328 em = alloc_extent_map();
329 if (!em) {
330 test_std_err(TEST_ALLOC_EXTENT_MAP);
331 return -ENOMEM;
332 }
333
334 /* Add [0K, 8K) */
335 em->start = 0;
336 em->len = SZ_8K;
337 em->block_start = 0;
338 em->block_len = SZ_8K;
339 write_lock(&em_tree->lock);
340 ret = add_extent_mapping(em_tree, em, 0);
341 write_unlock(&em_tree->lock);
342 if (ret < 0) {
343 test_err("cannot add extent range [0, 8K)");
344 goto out;
345 }
346 free_extent_map(em);
347
348 em = alloc_extent_map();
349 if (!em) {
350 test_std_err(TEST_ALLOC_EXTENT_MAP);
351 ret = -ENOMEM;
352 goto out;
353 }
354
355 /* Add [8K, 32K) */
356 em->start = SZ_8K;
357 em->len = 24 * SZ_1K;
358 em->block_start = SZ_16K; /* avoid merging */
359 em->block_len = 24 * SZ_1K;
360 write_lock(&em_tree->lock);
361 ret = add_extent_mapping(em_tree, em, 0);
362 write_unlock(&em_tree->lock);
363 if (ret < 0) {
364 test_err("cannot add extent range [8K, 32K)");
365 goto out;
366 }
367 free_extent_map(em);
368
369 em = alloc_extent_map();
370 if (!em) {
371 test_std_err(TEST_ALLOC_EXTENT_MAP);
372 ret = -ENOMEM;
373 goto out;
374 }
375 /* Add [0K, 32K) */
376 em->start = 0;
377 em->len = SZ_32K;
378 em->block_start = 0;
379 em->block_len = SZ_32K;
380 write_lock(&em_tree->lock);
381 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
382 write_unlock(&em_tree->lock);
383 if (ret) {
384 test_err("case4 [0x%llx 0x%llx): ret %d",
385 start, len, ret);
386 goto out;
387 }
388 if (em && (start < em->start || start + len > extent_map_end(em))) {
389 test_err(
390"case4 [0x%llx 0x%llx): ret %d, added wrong em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)",
391 start, len, ret, em->start, em->len, em->block_start,
392 em->block_len);
393 ret = -EINVAL;
394 }
395 free_extent_map(em);
396out:
397 free_extent_map_tree(em_tree);
398
399 return ret;
400}
401
402/*
403 * Test scenario:
404 *
405 * Suppose that no extent map has been loaded into memory yet.
406 * There is a file extent [0, 32K), two jobs are running concurrently
407 * against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio
408 * read from [0, 4K) or [4K, 8K).
409 *
410 * t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K).
411 *
412 * t1 t2
413 * btrfs_get_blocks_direct() btrfs_get_blocks_direct()
414 * -> btrfs_get_extent() -> btrfs_get_extent()
415 * -> lookup_extent_mapping()
416 * -> add_extent_mapping() -> lookup_extent_mapping()
417 * # load [0, 32K)
418 * -> btrfs_new_extent_direct()
419 * -> btrfs_drop_extent_cache()
420 * # split [0, 32K)
421 * -> add_extent_mapping()
422 * # add [8K, 32K)
423 * -> add_extent_mapping()
424 * # handle -EEXIST when adding
425 * # [0, 32K)
426 */
427static int test_case_4(struct btrfs_fs_info *fs_info,
428 struct extent_map_tree *em_tree)
429{
430 int ret;
431
432 ret = __test_case_4(fs_info, em_tree, 0);
433 if (ret)
434 return ret;
435 ret = __test_case_4(fs_info, em_tree, SZ_4K);
436
437 return ret;
438}
439
440int btrfs_test_extent_map(void)
441{
442 struct btrfs_fs_info *fs_info = NULL;
443 struct extent_map_tree *em_tree;
444 int ret = 0;
445
446 test_msg("running extent_map tests");
447
448 /*
449 * Note: the fs_info is not set up completely, we only need
450 * fs_info::fsid for the tracepoint.
451 */
452 fs_info = btrfs_alloc_dummy_fs_info(PAGE_SIZE, PAGE_SIZE);
453 if (!fs_info) {
454 test_std_err(TEST_ALLOC_FS_INFO);
455 return -ENOMEM;
456 }
457
458 em_tree = kzalloc(sizeof(*em_tree), GFP_KERNEL);
459 if (!em_tree) {
460 ret = -ENOMEM;
461 goto out;
462 }
463
464 extent_map_tree_init(em_tree);
465
466 ret = test_case_1(fs_info, em_tree);
467 if (ret)
468 goto out;
469 ret = test_case_2(fs_info, em_tree);
470 if (ret)
471 goto out;
472 ret = test_case_3(fs_info, em_tree);
473 if (ret)
474 goto out;
475 ret = test_case_4(fs_info, em_tree);
476
477out:
478 kfree(em_tree);
479 btrfs_free_dummy_fs_info(fs_info);
480
481 return ret;
482}