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

DEFINITIONS

1. process_page_range
2. test_find_delalloc
3. check_eb_bitmap
4. __test_eb_bitmaps
5. test_eb_bitmaps
6. test_find_first_clear_extent_bit
7. btrfs_test_extent_io

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2013 Fusion IO.  All rights reserved.
   4  */
   5 
   6 #include <linux/pagemap.h>
   7 #include <linux/sched.h>
   8 #include <linux/slab.h>
   9 #include <linux/sizes.h>
  10 #include "btrfs-tests.h"
  11 #include "../ctree.h"
  12 #include "../extent_io.h"
  13 #include "../btrfs_inode.h"
  14 
  15 #define PROCESS_UNLOCK          (1 << 0)
  16 #define PROCESS_RELEASE         (1 << 1)
  17 #define PROCESS_TEST_LOCKED     (1 << 2)
  18 
  19 static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
  20                                        unsigned long flags)
  21 {
  22         int ret;
  23         struct page *pages[16];
  24         unsigned long index = start >> PAGE_SHIFT;
  25         unsigned long end_index = end >> PAGE_SHIFT;
  26         unsigned long nr_pages = end_index - index + 1;
  27         int i;
  28         int count = 0;
  29         int loops = 0;
  30 
  31         while (nr_pages > 0) {
  32                 ret = find_get_pages_contig(inode->i_mapping, index,
  33                                      min_t(unsigned long, nr_pages,
  34                                      ARRAY_SIZE(pages)), pages);
  35                 for (i = 0; i < ret; i++) {
  36                         if (flags & PROCESS_TEST_LOCKED &&
  37                             !PageLocked(pages[i]))
  38                                 count++;
  39                         if (flags & PROCESS_UNLOCK && PageLocked(pages[i]))
  40                                 unlock_page(pages[i]);
  41                         put_page(pages[i]);
  42                         if (flags & PROCESS_RELEASE)
  43                                 put_page(pages[i]);
  44                 }
  45                 nr_pages -= ret;
  46                 index += ret;
  47                 cond_resched();
  48                 loops++;
  49                 if (loops > 100000) {
  50                         printk(KERN_ERR
  51                 "stuck in a loop, start %llu, end %llu, nr_pages %lu, ret %d\n",
  52                                 start, end, nr_pages, ret);
  53                         break;
  54                 }
  55         }
  56         return count;
  57 }
  58 
  59 static int test_find_delalloc(u32 sectorsize)
  60 {
  61         struct inode *inode;
  62         struct extent_io_tree *tmp;
  63         struct page *page;
  64         struct page *locked_page = NULL;
  65         unsigned long index = 0;
  66         /* In this test we need at least 2 file extents at its maximum size */
  67         u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
  68         u64 total_dirty = 2 * max_bytes;
  69         u64 start, end, test_start;
  70         bool found;
  71         int ret = -EINVAL;
  72 
  73         test_msg("running find delalloc tests");
  74 
  75         inode = btrfs_new_test_inode();
  76         if (!inode) {
  77                 test_std_err(TEST_ALLOC_INODE);
  78                 return -ENOMEM;
  79         }
  80         tmp = &BTRFS_I(inode)->io_tree;
  81 
  82         /*
  83          * Passing NULL as we don't have fs_info but tracepoints are not used
  84          * at this point
  85          */
  86         extent_io_tree_init(NULL, tmp, IO_TREE_SELFTEST, NULL);
  87 
  88         /*
  89          * First go through and create and mark all of our pages dirty, we pin
  90          * everything to make sure our pages don't get evicted and screw up our
  91          * test.
  92          */
  93         for (index = 0; index < (total_dirty >> PAGE_SHIFT); index++) {
  94                 page = find_or_create_page(inode->i_mapping, index, GFP_KERNEL);
  95                 if (!page) {
  96                         test_err("failed to allocate test page");
  97                         ret = -ENOMEM;
  98                         goto out;
  99                 }
 100                 SetPageDirty(page);
 101                 if (index) {
 102                         unlock_page(page);
 103                 } else {
 104                         get_page(page);
 105                         locked_page = page;
 106                 }
 107         }
 108 
 109         /* Test this scenario
 110          * |--- delalloc ---|
 111          * |---  search  ---|
 112          */
 113         set_extent_delalloc(tmp, 0, sectorsize - 1, 0, NULL);
 114         start = 0;
 115         end = 0;
 116         found = find_lock_delalloc_range(inode, locked_page, &start,
 117                                          &end);
 118         if (!found) {
 119                 test_err("should have found at least one delalloc");
 120                 goto out_bits;
 121         }
 122         if (start != 0 || end != (sectorsize - 1)) {
 123                 test_err("expected start 0 end %u, got start %llu end %llu",
 124                         sectorsize - 1, start, end);
 125                 goto out_bits;
 126         }
 127         unlock_extent(tmp, start, end);
 128         unlock_page(locked_page);
 129         put_page(locked_page);
 130 
 131         /*
 132          * Test this scenario
 133          *
 134          * |--- delalloc ---|
 135          *           |--- search ---|
 136          */
 137         test_start = SZ_64M;
 138         locked_page = find_lock_page(inode->i_mapping,
 139                                      test_start >> PAGE_SHIFT);
 140         if (!locked_page) {
 141                 test_err("couldn't find the locked page");
 142                 goto out_bits;
 143         }
 144         set_extent_delalloc(tmp, sectorsize, max_bytes - 1, 0, NULL);
 145         start = test_start;
 146         end = 0;
 147         found = find_lock_delalloc_range(inode, locked_page, &start,
 148                                          &end);
 149         if (!found) {
 150                 test_err("couldn't find delalloc in our range");
 151                 goto out_bits;
 152         }
 153         if (start != test_start || end != max_bytes - 1) {
 154                 test_err("expected start %llu end %llu, got start %llu, end %llu",
 155                                 test_start, max_bytes - 1, start, end);
 156                 goto out_bits;
 157         }
 158         if (process_page_range(inode, start, end,
 159                                PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 160                 test_err("there were unlocked pages in the range");
 161                 goto out_bits;
 162         }
 163         unlock_extent(tmp, start, end);
 164         /* locked_page was unlocked above */
 165         put_page(locked_page);
 166 
 167         /*
 168          * Test this scenario
 169          * |--- delalloc ---|
 170          *                    |--- search ---|
 171          */
 172         test_start = max_bytes + sectorsize;
 173         locked_page = find_lock_page(inode->i_mapping, test_start >>
 174                                      PAGE_SHIFT);
 175         if (!locked_page) {
 176                 test_err("couldn't find the locked page");
 177                 goto out_bits;
 178         }
 179         start = test_start;
 180         end = 0;
 181         found = find_lock_delalloc_range(inode, locked_page, &start,
 182                                          &end);
 183         if (found) {
 184                 test_err("found range when we shouldn't have");
 185                 goto out_bits;
 186         }
 187         if (end != (u64)-1) {
 188                 test_err("did not return the proper end offset");
 189                 goto out_bits;
 190         }
 191 
 192         /*
 193          * Test this scenario
 194          * [------- delalloc -------|
 195          * [max_bytes]|-- search--|
 196          *
 197          * We are re-using our test_start from above since it works out well.
 198          */
 199         set_extent_delalloc(tmp, max_bytes, total_dirty - 1, 0, NULL);
 200         start = test_start;
 201         end = 0;
 202         found = find_lock_delalloc_range(inode, locked_page, &start,
 203                                          &end);
 204         if (!found) {
 205                 test_err("didn't find our range");
 206                 goto out_bits;
 207         }
 208         if (start != test_start || end != total_dirty - 1) {
 209                 test_err("expected start %llu end %llu, got start %llu end %llu",
 210                          test_start, total_dirty - 1, start, end);
 211                 goto out_bits;
 212         }
 213         if (process_page_range(inode, start, end,
 214                                PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
 215                 test_err("pages in range were not all locked");
 216                 goto out_bits;
 217         }
 218         unlock_extent(tmp, start, end);
 219 
 220         /*
 221          * Now to test where we run into a page that is no longer dirty in the
 222          * range we want to find.
 223          */
 224         page = find_get_page(inode->i_mapping,
 225                              (max_bytes + SZ_1M) >> PAGE_SHIFT);
 226         if (!page) {
 227                 test_err("couldn't find our page");
 228                 goto out_bits;
 229         }
 230         ClearPageDirty(page);
 231         put_page(page);
 232 
 233         /* We unlocked it in the previous test */
 234         lock_page(locked_page);
 235         start = test_start;
 236         end = 0;
 237         /*
 238          * Currently if we fail to find dirty pages in the delalloc range we
 239          * will adjust max_bytes down to PAGE_SIZE and then re-search.  If
 240          * this changes at any point in the future we will need to fix this
 241          * tests expected behavior.
 242          */
 243         found = find_lock_delalloc_range(inode, locked_page, &start,
 244                                          &end);
 245         if (!found) {
 246                 test_err("didn't find our range");
 247                 goto out_bits;
 248         }
 249         if (start != test_start && end != test_start + PAGE_SIZE - 1) {
 250                 test_err("expected start %llu end %llu, got start %llu end %llu",
 251                          test_start, test_start + PAGE_SIZE - 1, start, end);
 252                 goto out_bits;
 253         }
 254         if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED |
 255                                PROCESS_UNLOCK)) {
 256                 test_err("pages in range were not all locked");
 257                 goto out_bits;
 258         }
 259         ret = 0;
 260 out_bits:
 261         clear_extent_bits(tmp, 0, total_dirty - 1, (unsigned)-1);
 262 out:
 263         if (locked_page)
 264                 put_page(locked_page);
 265         process_page_range(inode, 0, total_dirty - 1,
 266                            PROCESS_UNLOCK | PROCESS_RELEASE);
 267         iput(inode);
 268         return ret;
 269 }
 270 
 271 static int check_eb_bitmap(unsigned long *bitmap, struct extent_buffer *eb,
 272                            unsigned long len)
 273 {
 274         unsigned long i;
 275 
 276         for (i = 0; i < len * BITS_PER_BYTE; i++) {
 277                 int bit, bit1;
 278 
 279                 bit = !!test_bit(i, bitmap);
 280                 bit1 = !!extent_buffer_test_bit(eb, 0, i);
 281                 if (bit1 != bit) {
 282                         test_err("bits do not match");
 283                         return -EINVAL;
 284                 }
 285 
 286                 bit1 = !!extent_buffer_test_bit(eb, i / BITS_PER_BYTE,
 287                                                 i % BITS_PER_BYTE);
 288                 if (bit1 != bit) {
 289                         test_err("offset bits do not match");
 290                         return -EINVAL;
 291                 }
 292         }
 293         return 0;
 294 }
 295 
 296 static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb,
 297                              unsigned long len)
 298 {
 299         unsigned long i, j;
 300         u32 x;
 301         int ret;
 302 
 303         memset(bitmap, 0, len);
 304         memzero_extent_buffer(eb, 0, len);
 305         if (memcmp_extent_buffer(eb, bitmap, 0, len) != 0) {
 306                 test_err("bitmap was not zeroed");
 307                 return -EINVAL;
 308         }
 309 
 310         bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
 311         extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
 312         ret = check_eb_bitmap(bitmap, eb, len);
 313         if (ret) {
 314                 test_err("setting all bits failed");
 315                 return ret;
 316         }
 317 
 318         bitmap_clear(bitmap, 0, len * BITS_PER_BYTE);
 319         extent_buffer_bitmap_clear(eb, 0, 0, len * BITS_PER_BYTE);
 320         ret = check_eb_bitmap(bitmap, eb, len);
 321         if (ret) {
 322                 test_err("clearing all bits failed");
 323                 return ret;
 324         }
 325 
 326         /* Straddling pages test */
 327         if (len > PAGE_SIZE) {
 328                 bitmap_set(bitmap,
 329                         (PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
 330                         sizeof(long) * BITS_PER_BYTE);
 331                 extent_buffer_bitmap_set(eb, PAGE_SIZE - sizeof(long) / 2, 0,
 332                                         sizeof(long) * BITS_PER_BYTE);
 333                 ret = check_eb_bitmap(bitmap, eb, len);
 334                 if (ret) {
 335                         test_err("setting straddling pages failed");
 336                         return ret;
 337                 }
 338 
 339                 bitmap_set(bitmap, 0, len * BITS_PER_BYTE);
 340                 bitmap_clear(bitmap,
 341                         (PAGE_SIZE - sizeof(long) / 2) * BITS_PER_BYTE,
 342                         sizeof(long) * BITS_PER_BYTE);
 343                 extent_buffer_bitmap_set(eb, 0, 0, len * BITS_PER_BYTE);
 344                 extent_buffer_bitmap_clear(eb, PAGE_SIZE - sizeof(long) / 2, 0,
 345                                         sizeof(long) * BITS_PER_BYTE);
 346                 ret = check_eb_bitmap(bitmap, eb, len);
 347                 if (ret) {
 348                         test_err("clearing straddling pages failed");
 349                         return ret;
 350                 }
 351         }
 352 
 353         /*
 354          * Generate a wonky pseudo-random bit pattern for the sake of not using
 355          * something repetitive that could miss some hypothetical off-by-n bug.
 356          */
 357         x = 0;
 358         bitmap_clear(bitmap, 0, len * BITS_PER_BYTE);
 359         extent_buffer_bitmap_clear(eb, 0, 0, len * BITS_PER_BYTE);
 360         for (i = 0; i < len * BITS_PER_BYTE / 32; i++) {
 361                 x = (0x19660dULL * (u64)x + 0x3c6ef35fULL) & 0xffffffffU;
 362                 for (j = 0; j < 32; j++) {
 363                         if (x & (1U << j)) {
 364                                 bitmap_set(bitmap, i * 32 + j, 1);
 365                                 extent_buffer_bitmap_set(eb, 0, i * 32 + j, 1);
 366                         }
 367                 }
 368         }
 369 
 370         ret = check_eb_bitmap(bitmap, eb, len);
 371         if (ret) {
 372                 test_err("random bit pattern failed");
 373                 return ret;
 374         }
 375 
 376         return 0;
 377 }
 378 
 379 static int test_eb_bitmaps(u32 sectorsize, u32 nodesize)
 380 {
 381         struct btrfs_fs_info *fs_info;
 382         unsigned long len;
 383         unsigned long *bitmap = NULL;
 384         struct extent_buffer *eb = NULL;
 385         int ret;
 386 
 387         test_msg("running extent buffer bitmap tests");
 388 
 389         /*
 390          * In ppc64, sectorsize can be 64K, thus 4 * 64K will be larger than
 391          * BTRFS_MAX_METADATA_BLOCKSIZE.
 392          */
 393         len = (sectorsize < BTRFS_MAX_METADATA_BLOCKSIZE)
 394                 ? sectorsize * 4 : sectorsize;
 395 
 396         fs_info = btrfs_alloc_dummy_fs_info(len, len);
 397         if (!fs_info) {
 398                 test_std_err(TEST_ALLOC_FS_INFO);
 399                 return -ENOMEM;
 400         }
 401 
 402         bitmap = kmalloc(len, GFP_KERNEL);
 403         if (!bitmap) {
 404                 test_err("couldn't allocate test bitmap");
 405                 ret = -ENOMEM;
 406                 goto out;
 407         }
 408 
 409         eb = __alloc_dummy_extent_buffer(fs_info, 0, len);
 410         if (!eb) {
 411                 test_std_err(TEST_ALLOC_ROOT);
 412                 ret = -ENOMEM;
 413                 goto out;
 414         }
 415 
 416         ret = __test_eb_bitmaps(bitmap, eb, len);
 417         if (ret)
 418                 goto out;
 419 
 420         /* Do it over again with an extent buffer which isn't page-aligned. */
 421         free_extent_buffer(eb);
 422         eb = __alloc_dummy_extent_buffer(fs_info, nodesize / 2, len);
 423         if (!eb) {
 424                 test_std_err(TEST_ALLOC_ROOT);
 425                 ret = -ENOMEM;
 426                 goto out;
 427         }
 428 
 429         ret = __test_eb_bitmaps(bitmap, eb, len);
 430 out:
 431         free_extent_buffer(eb);
 432         kfree(bitmap);
 433         btrfs_free_dummy_fs_info(fs_info);
 434         return ret;
 435 }
 436 
 437 static int test_find_first_clear_extent_bit(void)
 438 {
 439         struct extent_io_tree tree;
 440         u64 start, end;
 441         int ret = -EINVAL;
 442 
 443         test_msg("running find_first_clear_extent_bit test");
 444 
 445         extent_io_tree_init(NULL, &tree, IO_TREE_SELFTEST, NULL);
 446 
 447         /* Test correct handling of empty tree */
 448         find_first_clear_extent_bit(&tree, 0, &start, &end, CHUNK_TRIMMED);
 449         if (start != 0 || end != -1) {
 450                 test_err(
 451         "error getting a range from completely empty tree: start %llu end %llu",
 452                          start, end);
 453                 goto out;
 454         }
 455         /*
 456          * Set 1M-4M alloc/discard and 32M-64M thus leaving a hole between
 457          * 4M-32M
 458          */
 459         set_extent_bits(&tree, SZ_1M, SZ_4M - 1,
 460                         CHUNK_TRIMMED | CHUNK_ALLOCATED);
 461 
 462         find_first_clear_extent_bit(&tree, SZ_512K, &start, &end,
 463                                     CHUNK_TRIMMED | CHUNK_ALLOCATED);
 464 
 465         if (start != 0 || end != SZ_1M - 1) {
 466                 test_err("error finding beginning range: start %llu end %llu",
 467                          start, end);
 468                 goto out;
 469         }
 470 
 471         /* Now add 32M-64M so that we have a hole between 4M-32M */
 472         set_extent_bits(&tree, SZ_32M, SZ_64M - 1,
 473                         CHUNK_TRIMMED | CHUNK_ALLOCATED);
 474 
 475         /*
 476          * Request first hole starting at 12M, we should get 4M-32M
 477          */
 478         find_first_clear_extent_bit(&tree, 12 * SZ_1M, &start, &end,
 479                                     CHUNK_TRIMMED | CHUNK_ALLOCATED);
 480 
 481         if (start != SZ_4M || end != SZ_32M - 1) {
 482                 test_err("error finding trimmed range: start %llu end %llu",
 483                          start, end);
 484                 goto out;
 485         }
 486 
 487         /*
 488          * Search in the middle of allocated range, should get the next one
 489          * available, which happens to be unallocated -> 4M-32M
 490          */
 491         find_first_clear_extent_bit(&tree, SZ_2M, &start, &end,
 492                                     CHUNK_TRIMMED | CHUNK_ALLOCATED);
 493 
 494         if (start != SZ_4M || end != SZ_32M - 1) {
 495                 test_err("error finding next unalloc range: start %llu end %llu",
 496                          start, end);
 497                 goto out;
 498         }
 499 
 500         /*
 501          * Set 64M-72M with CHUNK_ALLOC flag, then search for CHUNK_TRIMMED flag
 502          * being unset in this range, we should get the entry in range 64M-72M
 503          */
 504         set_extent_bits(&tree, SZ_64M, SZ_64M + SZ_8M - 1, CHUNK_ALLOCATED);
 505         find_first_clear_extent_bit(&tree, SZ_64M + SZ_1M, &start, &end,
 506                                     CHUNK_TRIMMED);
 507 
 508         if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
 509                 test_err("error finding exact range: start %llu end %llu",
 510                          start, end);
 511                 goto out;
 512         }
 513 
 514         find_first_clear_extent_bit(&tree, SZ_64M - SZ_8M, &start, &end,
 515                                     CHUNK_TRIMMED);
 516 
 517         /*
 518          * Search in the middle of set range whose immediate neighbour doesn't
 519          * have the bits set so it must be returned
 520          */
 521         if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
 522                 test_err("error finding next alloc range: start %llu end %llu",
 523                          start, end);
 524                 goto out;
 525         }
 526 
 527         /*
 528          * Search beyond any known range, shall return after last known range
 529          * and end should be -1
 530          */
 531         find_first_clear_extent_bit(&tree, -1, &start, &end, CHUNK_TRIMMED);
 532         if (start != SZ_64M + SZ_8M || end != -1) {
 533                 test_err(
 534                 "error handling beyond end of range search: start %llu end %llu",
 535                         start, end);
 536                 goto out;
 537         }
 538 
 539         ret = 0;
 540 out:
 541         clear_extent_bits(&tree, 0, (u64)-1, CHUNK_TRIMMED | CHUNK_ALLOCATED);
 542 
 543         return ret;
 544 }
 545 
 546 int btrfs_test_extent_io(u32 sectorsize, u32 nodesize)
 547 {
 548         int ret;
 549 
 550         test_msg("running extent I/O tests");
 551 
 552         ret = test_find_delalloc(sectorsize);
 553         if (ret)
 554                 goto out;
 555 
 556         ret = test_find_first_clear_extent_bit();
 557         if (ret)
 558                 goto out;
 559 
 560         ret = test_eb_bitmaps(sectorsize, nodesize);
 561 out:
 562         return ret;
 563 }