root/fs/btrfs/tests/extent-map-tests.c

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DEFINITIONS

This source file includes following definitions.
  1. free_extent_map_tree
  2. test_case_1
  3. test_case_2
  4. __test_case_3
  5. test_case_3
  6. __test_case_4
  7. test_case_4
  8. btrfs_test_extent_map
   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.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  */
  50 static 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);
 128 out:
 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  */
 140 static 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);
 216 out:
 217         free_extent_map_tree(em_tree);
 218 
 219         return ret;
 220 }
 221 
 222 static 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);
 283 out:
 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  */
 305 static 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 
 321 static 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);
 396 out:
 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  */
 427 static 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 
 440 int 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 
 477 out:
 478         kfree(em_tree);
 479         btrfs_free_dummy_fs_info(fs_info);
 480 
 481         return ret;
 482 }
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