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 10 static 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_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 */ 50 static void 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 /* Skip the test on error. */ 61 return; 62 63 /* Add [0, 16K) */ 64 em->start = 0; 65 em->len = SZ_16K; 66 em->block_start = 0; 67 em->block_len = SZ_16K; 68 ret = add_extent_mapping(em_tree, em, 0); 69 ASSERT(ret == 0); 70 free_extent_map(em); 71 72 /* Add [16K, 20K) following [0, 16K) */ 73 em = alloc_extent_map(); 74 if (!em) 75 goto out; 76 77 em->start = SZ_16K; 78 em->len = SZ_4K; 79 em->block_start = SZ_32K; /* avoid merging */ 80 em->block_len = SZ_4K; 81 ret = add_extent_mapping(em_tree, em, 0); 82 ASSERT(ret == 0); 83 free_extent_map(em); 84 85 em = alloc_extent_map(); 86 if (!em) 87 goto out; 88 89 /* Add [0, 8K), should return [0, 16K) instead. */ 90 em->start = start; 91 em->len = len; 92 em->block_start = start; 93 em->block_len = len; 94 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len); 95 if (ret) 96 test_err("case1 [%llu %llu]: ret %d", start, start + len, ret); 97 if (em && 98 (em->start != 0 || extent_map_end(em) != SZ_16K || 99 em->block_start != 0 || em->block_len != SZ_16K)) 100 test_err( 101 "case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu", 102 start, start + len, ret, em->start, em->len, 103 em->block_start, em->block_len); 104 free_extent_map(em); 105 out: 106 /* free memory */ 107 free_extent_map_tree(em_tree); 108 } 109 110 /* 111 * Test scenario: 112 * 113 * Reading the inline ending up with EEXIST, ie. read an inline 114 * extent and discard page cache and read it again. 115 */ 116 static void test_case_2(struct btrfs_fs_info *fs_info, 117 struct extent_map_tree *em_tree) 118 { 119 struct extent_map *em; 120 int ret; 121 122 em = alloc_extent_map(); 123 if (!em) 124 /* Skip the test on error. */ 125 return; 126 127 /* Add [0, 1K) */ 128 em->start = 0; 129 em->len = SZ_1K; 130 em->block_start = EXTENT_MAP_INLINE; 131 em->block_len = (u64)-1; 132 ret = add_extent_mapping(em_tree, em, 0); 133 ASSERT(ret == 0); 134 free_extent_map(em); 135 136 /* Add [4K, 4K) following [0, 1K) */ 137 em = alloc_extent_map(); 138 if (!em) 139 goto out; 140 141 em->start = SZ_4K; 142 em->len = SZ_4K; 143 em->block_start = SZ_4K; 144 em->block_len = SZ_4K; 145 ret = add_extent_mapping(em_tree, em, 0); 146 ASSERT(ret == 0); 147 free_extent_map(em); 148 149 em = alloc_extent_map(); 150 if (!em) 151 goto out; 152 153 /* Add [0, 1K) */ 154 em->start = 0; 155 em->len = SZ_1K; 156 em->block_start = EXTENT_MAP_INLINE; 157 em->block_len = (u64)-1; 158 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, em->start, em->len); 159 if (ret) 160 test_err("case2 [0 1K]: ret %d", ret); 161 if (em && 162 (em->start != 0 || extent_map_end(em) != SZ_1K || 163 em->block_start != EXTENT_MAP_INLINE || em->block_len != (u64)-1)) 164 test_err( 165 "case2 [0 1K]: ret %d return a wrong em (start %llu len %llu block_start %llu block_len %llu", 166 ret, em->start, em->len, em->block_start, 167 em->block_len); 168 free_extent_map(em); 169 out: 170 /* free memory */ 171 free_extent_map_tree(em_tree); 172 } 173 174 static void __test_case_3(struct btrfs_fs_info *fs_info, 175 struct extent_map_tree *em_tree, u64 start) 176 { 177 struct extent_map *em; 178 u64 len = SZ_4K; 179 int ret; 180 181 em = alloc_extent_map(); 182 if (!em) 183 /* Skip this test on error. */ 184 return; 185 186 /* Add [4K, 8K) */ 187 em->start = SZ_4K; 188 em->len = SZ_4K; 189 em->block_start = SZ_4K; 190 em->block_len = SZ_4K; 191 ret = add_extent_mapping(em_tree, em, 0); 192 ASSERT(ret == 0); 193 free_extent_map(em); 194 195 em = alloc_extent_map(); 196 if (!em) 197 goto out; 198 199 /* Add [0, 16K) */ 200 em->start = 0; 201 em->len = SZ_16K; 202 em->block_start = 0; 203 em->block_len = SZ_16K; 204 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len); 205 if (ret) 206 test_err("case3 [0x%llx 0x%llx): ret %d", 207 start, start + len, ret); 208 /* 209 * Since bytes within em are contiguous, em->block_start is identical to 210 * em->start. 211 */ 212 if (em && 213 (start < em->start || start + len > extent_map_end(em) || 214 em->start != em->block_start || em->len != em->block_len)) 215 test_err( 216 "case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)", 217 start, start + len, ret, em->start, em->len, 218 em->block_start, em->block_len); 219 free_extent_map(em); 220 out: 221 /* free memory */ 222 free_extent_map_tree(em_tree); 223 } 224 225 /* 226 * Test scenario: 227 * 228 * Suppose that no extent map has been loaded into memory yet. 229 * There is a file extent [0, 16K), two jobs are running concurrently 230 * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio 231 * read from [0, 4K) or [8K, 12K) or [12K, 16K). 232 * 233 * t1 goes ahead of t2 and adds em [4K, 8K) into tree. 234 * 235 * t1 t2 236 * cow_file_range() btrfs_get_extent() 237 * -> lookup_extent_mapping() 238 * -> add_extent_mapping() 239 * -> add_extent_mapping() 240 */ 241 static void test_case_3(struct btrfs_fs_info *fs_info, 242 struct extent_map_tree *em_tree) 243 { 244 __test_case_3(fs_info, em_tree, 0); 245 __test_case_3(fs_info, em_tree, SZ_8K); 246 __test_case_3(fs_info, em_tree, (12 * 1024ULL)); 247 } 248 249 static void __test_case_4(struct btrfs_fs_info *fs_info, 250 struct extent_map_tree *em_tree, u64 start) 251 { 252 struct extent_map *em; 253 u64 len = SZ_4K; 254 int ret; 255 256 em = alloc_extent_map(); 257 if (!em) 258 /* Skip this test on error. */ 259 return; 260 261 /* Add [0K, 8K) */ 262 em->start = 0; 263 em->len = SZ_8K; 264 em->block_start = 0; 265 em->block_len = SZ_8K; 266 ret = add_extent_mapping(em_tree, em, 0); 267 ASSERT(ret == 0); 268 free_extent_map(em); 269 270 em = alloc_extent_map(); 271 if (!em) 272 goto out; 273 274 /* Add [8K, 24K) */ 275 em->start = SZ_8K; 276 em->len = 24 * 1024ULL; 277 em->block_start = SZ_16K; /* avoid merging */ 278 em->block_len = 24 * 1024ULL; 279 ret = add_extent_mapping(em_tree, em, 0); 280 ASSERT(ret == 0); 281 free_extent_map(em); 282 283 em = alloc_extent_map(); 284 if (!em) 285 goto out; 286 /* Add [0K, 32K) */ 287 em->start = 0; 288 em->len = SZ_32K; 289 em->block_start = 0; 290 em->block_len = SZ_32K; 291 ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len); 292 if (ret) 293 test_err("case4 [0x%llx 0x%llx): ret %d", 294 start, len, ret); 295 if (em && 296 (start < em->start || start + len > extent_map_end(em))) 297 test_err( 298 "case4 [0x%llx 0x%llx): ret %d, added wrong em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)", 299 start, len, ret, em->start, em->len, em->block_start, 300 em->block_len); 301 free_extent_map(em); 302 out: 303 /* free memory */ 304 free_extent_map_tree(em_tree); 305 } 306 307 /* 308 * Test scenario: 309 * 310 * Suppose that no extent map has been loaded into memory yet. 311 * There is a file extent [0, 32K), two jobs are running concurrently 312 * against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio 313 * read from [0, 4K) or [4K, 8K). 314 * 315 * t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K). 316 * 317 * t1 t2 318 * btrfs_get_blocks_direct() btrfs_get_blocks_direct() 319 * -> btrfs_get_extent() -> btrfs_get_extent() 320 * -> lookup_extent_mapping() 321 * -> add_extent_mapping() -> lookup_extent_mapping() 322 * # load [0, 32K) 323 * -> btrfs_new_extent_direct() 324 * -> btrfs_drop_extent_cache() 325 * # split [0, 32K) 326 * -> add_extent_mapping() 327 * # add [8K, 32K) 328 * -> add_extent_mapping() 329 * # handle -EEXIST when adding 330 * # [0, 32K) 331 */ 332 static void test_case_4(struct btrfs_fs_info *fs_info, 333 struct extent_map_tree *em_tree) 334 { 335 __test_case_4(fs_info, em_tree, 0); 336 __test_case_4(fs_info, em_tree, SZ_4K); 337 } 338 339 int btrfs_test_extent_map(void) 340 { 341 struct btrfs_fs_info *fs_info = NULL; 342 struct extent_map_tree *em_tree; 343 344 test_msg("running extent_map tests"); 345 346 /* 347 * Note: the fs_info is not set up completely, we only need 348 * fs_info::fsid for the tracepoint. 349 */ 350 fs_info = btrfs_alloc_dummy_fs_info(PAGE_SIZE, PAGE_SIZE); 351 if (!fs_info) { 352 test_msg("Couldn't allocate dummy fs info"); 353 return -ENOMEM; 354 } 355 356 em_tree = kzalloc(sizeof(*em_tree), GFP_KERNEL); 357 if (!em_tree) 358 /* Skip the test on error. */ 359 goto out; 360 361 extent_map_tree_init(em_tree); 362 363 test_case_1(fs_info, em_tree); 364 test_case_2(fs_info, em_tree); 365 test_case_3(fs_info, em_tree); 366 test_case_4(fs_info, em_tree); 367 368 kfree(em_tree); 369 out: 370 btrfs_free_dummy_fs_info(fs_info); 371 372 return 0; 373 } 374