fs/ext4/mballoc-test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * KUnit test of ext4 multiblocks allocation.
   4  */
   5
   6 #include <kunit/test.h>
   7 #include <kunit/static_stub.h>
   8
   9 #include "ext4.h"
  10
  11 struct mbt_grp_ctx {
  12         struct buffer_head bitmap_bh;
  13         /* desc and gd_bh are just the place holders for now */
  14         struct ext4_group_desc desc;
  15         struct buffer_head gd_bh;
  16 };
  17
  18 struct mbt_ctx {
  19         struct mbt_grp_ctx *grp_ctx;
  20 };
  21
  22 struct mbt_ext4_super_block {
  23         struct super_block sb;
  24         struct mbt_ctx mbt_ctx;
  25 };
  26
  27 #define MBT_CTX(_sb) (&(container_of((_sb), struct mbt_ext4_super_block, sb)->mbt_ctx))
  28 #define MBT_GRP_CTX(_sb, _group) (&MBT_CTX(_sb)->grp_ctx[_group])
  29
  30 static struct super_block *mbt_ext4_alloc_super_block(void)
  31 {
  32         struct ext4_super_block *es = kzalloc(sizeof(*es), GFP_KERNEL);
  33         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
  34         struct mbt_ext4_super_block *fsb = kzalloc(sizeof(*fsb), GFP_KERNEL);
  35
  36         if (fsb == NULL || sbi == NULL || es == NULL)
  37                 goto out;
  38
  39         sbi->s_es = es;
  40         fsb->sb.s_fs_info = sbi;
  41         return &fsb->sb;
  42
  43 out:
  44         kfree(fsb);
  45         kfree(sbi);
  46         kfree(es);
  47         return NULL;
  48 }
  49
  50 static void mbt_ext4_free_super_block(struct super_block *sb)
  51 {
  52         struct mbt_ext4_super_block *fsb =
  53                 container_of(sb, struct mbt_ext4_super_block, sb);
  54         struct ext4_sb_info *sbi = EXT4_SB(sb);
  55
  56         kfree(sbi->s_es);
  57         kfree(sbi);
  58         kfree(fsb);
  59 }
  60
  61 struct mbt_ext4_block_layout {
  62         unsigned char blocksize_bits;
  63         unsigned int cluster_bits;
  64         uint32_t blocks_per_group;
  65         ext4_group_t group_count;
  66         uint16_t desc_size;
  67 };
  68
  69 static void mbt_init_sb_layout(struct super_block *sb,
  70                                struct mbt_ext4_block_layout *layout)
  71 {
  72         struct ext4_sb_info *sbi = EXT4_SB(sb);
  73         struct ext4_super_block *es = sbi->s_es;
  74
  75         sb->s_blocksize = 1UL << layout->blocksize_bits;
  76         sb->s_blocksize_bits = layout->blocksize_bits;
  77
  78         sbi->s_groups_count = layout->group_count;
  79         sbi->s_blocks_per_group = layout->blocks_per_group;
  80         sbi->s_cluster_bits = layout->cluster_bits;
  81         sbi->s_cluster_ratio = 1U << layout->cluster_bits;
  82         sbi->s_clusters_per_group = layout->blocks_per_group >>
  83                                     layout->cluster_bits;
  84         sbi->s_desc_size = layout->desc_size;
  85
  86         es->s_first_data_block = cpu_to_le32(0);
  87         es->s_blocks_count_lo = cpu_to_le32(layout->blocks_per_group *
  88                                             layout->group_count);
  89 }
  90
  91 static int mbt_grp_ctx_init(struct super_block *sb,
  92                             struct mbt_grp_ctx *grp_ctx)
  93 {
  94         grp_ctx->bitmap_bh.b_data = kzalloc(EXT4_BLOCK_SIZE(sb), GFP_KERNEL);
  95         if (grp_ctx->bitmap_bh.b_data == NULL)
  96                 return -ENOMEM;
  97
  98         return 0;
  99 }
 100
 101 static void mbt_grp_ctx_release(struct mbt_grp_ctx *grp_ctx)
 102 {
 103         kfree(grp_ctx->bitmap_bh.b_data);
 104         grp_ctx->bitmap_bh.b_data = NULL;
 105 }
 106
 107 static void mbt_ctx_mark_used(struct super_block *sb, ext4_group_t group,
 108                               unsigned int start, unsigned int len)
 109 {
 110         struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
 111
 112         mb_set_bits(grp_ctx->bitmap_bh.b_data, start, len);
 113 }
 114
 115 /* called after mbt_init_sb_layout */
 116 static int mbt_ctx_init(struct super_block *sb)
 117 {
 118         struct mbt_ctx *ctx = MBT_CTX(sb);
 119         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
 120
 121         ctx->grp_ctx = kcalloc(ngroups, sizeof(struct mbt_grp_ctx),
 122                                GFP_KERNEL);
 123         if (ctx->grp_ctx == NULL)
 124                 return -ENOMEM;
 125
 126         for (i = 0; i < ngroups; i++)
 127                 if (mbt_grp_ctx_init(sb, &ctx->grp_ctx[i]))
 128                         goto out;
 129
 130         /*
 131          * first data block(first cluster in first group) is used by
 132          * metadata, mark it used to avoid to alloc data block at first
 133          * block which will fail ext4_sb_block_valid check.
 134          */
 135         mb_set_bits(ctx->grp_ctx[0].bitmap_bh.b_data, 0, 1);
 136
 137         return 0;
 138 out:
 139         while (i-- > 0)
 140                 mbt_grp_ctx_release(&ctx->grp_ctx[i]);
 141         kfree(ctx->grp_ctx);
 142         return -ENOMEM;
 143 }
 144
 145 static void mbt_ctx_release(struct super_block *sb)
 146 {
 147         struct mbt_ctx *ctx = MBT_CTX(sb);
 148         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
 149
 150         for (i = 0; i < ngroups; i++)
 151                 mbt_grp_ctx_release(&ctx->grp_ctx[i]);
 152         kfree(ctx->grp_ctx);
 153 }
 154
 155 static struct buffer_head *
 156 ext4_read_block_bitmap_nowait_stub(struct super_block *sb, ext4_group_t block_group,
 157                                    bool ignore_locked)
 158 {
 159         struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
 160
 161         /* paired with brelse from caller of ext4_read_block_bitmap_nowait */
 162         get_bh(&grp_ctx->bitmap_bh);
 163         return &grp_ctx->bitmap_bh;
 164 }
 165
 166 static int ext4_wait_block_bitmap_stub(struct super_block *sb,
 167                                        ext4_group_t block_group,
 168                                        struct buffer_head *bh)
 169 {
 170         return 0;
 171 }
 172
 173 static struct ext4_group_desc *
 174 ext4_get_group_desc_stub(struct super_block *sb, ext4_group_t block_group,
 175                          struct buffer_head **bh)
 176 {
 177         struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
 178
 179         if (bh != NULL)
 180                 *bh = &grp_ctx->gd_bh;
 181
 182         return &grp_ctx->desc;
 183 }
 184
 185 static int
 186 ext4_mb_mark_context_stub(handle_t *handle, struct super_block *sb, bool state,
 187                           ext4_group_t group, ext4_grpblk_t blkoff,
 188                           ext4_grpblk_t len, int flags,
 189                           ext4_grpblk_t *ret_changed)
 190 {
 191         struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
 192         struct buffer_head *bitmap_bh = &grp_ctx->bitmap_bh;
 193
 194         if (state)
 195                 mb_set_bits(bitmap_bh->b_data, blkoff, len);
 196         else
 197                 mb_clear_bits(bitmap_bh->b_data, blkoff, len);
 198
 199         return 0;
 200 }
 201
 202 #define TEST_GOAL_GROUP 1
 203 static int mbt_kunit_init(struct kunit *test)
 204 {
 205         struct mbt_ext4_block_layout *layout =
 206                 (struct mbt_ext4_block_layout *)(test->param_value);
 207         struct super_block *sb;
 208         int ret;
 209
 210         sb = mbt_ext4_alloc_super_block();
 211         if (sb == NULL)
 212                 return -ENOMEM;
 213
 214         mbt_init_sb_layout(sb, layout);
 215
 216         ret = mbt_ctx_init(sb);
 217         if (ret != 0) {
 218                 mbt_ext4_free_super_block(sb);
 219                 return ret;
 220         }
 221
 222         test->priv = sb;
 223         kunit_activate_static_stub(test,
 224                                    ext4_read_block_bitmap_nowait,
 225                                    ext4_read_block_bitmap_nowait_stub);
 226         kunit_activate_static_stub(test,
 227                                    ext4_wait_block_bitmap,
 228                                    ext4_wait_block_bitmap_stub);
 229         kunit_activate_static_stub(test,
 230                                    ext4_get_group_desc,
 231                                    ext4_get_group_desc_stub);
 232         kunit_activate_static_stub(test,
 233                                    ext4_mb_mark_context,
 234                                    ext4_mb_mark_context_stub);
 235         return 0;
 236 }
 237
 238 static void mbt_kunit_exit(struct kunit *test)
 239 {
 240         struct super_block *sb = (struct super_block *)test->priv;
 241
 242         mbt_ctx_release(sb);
 243         mbt_ext4_free_super_block(sb);
 244 }
 245
 246 static void test_new_blocks_simple(struct kunit *test)
 247 {
 248         struct super_block *sb = (struct super_block *)test->priv;
 249         struct inode inode = { .i_sb = sb, };
 250         struct ext4_allocation_request ar;
 251         ext4_group_t i, goal_group = TEST_GOAL_GROUP;
 252         int err = 0;
 253         ext4_fsblk_t found;
 254         struct ext4_sb_info *sbi = EXT4_SB(sb);
 255
 256         ar.inode = &inode;
 257
 258         /* get block at goal */
 259         ar.goal = ext4_group_first_block_no(sb, goal_group);
 260         found = ext4_mb_new_blocks_simple(&ar, &err);
 261         KUNIT_ASSERT_EQ_MSG(test, ar.goal, found,
 262                 "failed to alloc block at goal, expected %llu found %llu",
 263                 ar.goal, found);
 264
 265         /* get block after goal in goal group */
 266         ar.goal = ext4_group_first_block_no(sb, goal_group);
 267         found = ext4_mb_new_blocks_simple(&ar, &err);
 268         KUNIT_ASSERT_EQ_MSG(test, ar.goal + EXT4_C2B(sbi, 1), found,
 269                 "failed to alloc block after goal in goal group, expected %llu found %llu",
 270                 ar.goal + 1, found);
 271
 272         /* get block after goal group */
 273         mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
 274         ar.goal = ext4_group_first_block_no(sb, goal_group);
 275         found = ext4_mb_new_blocks_simple(&ar, &err);
 276         KUNIT_ASSERT_EQ_MSG(test,
 277                 ext4_group_first_block_no(sb, goal_group + 1), found,
 278                 "failed to alloc block after goal group, expected %llu found %llu",
 279                 ext4_group_first_block_no(sb, goal_group + 1), found);
 280
 281         /* get block before goal group */
 282         for (i = goal_group; i < ext4_get_groups_count(sb); i++)
 283                 mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
 284         ar.goal = ext4_group_first_block_no(sb, goal_group);
 285         found = ext4_mb_new_blocks_simple(&ar, &err);
 286         KUNIT_ASSERT_EQ_MSG(test,
 287                 ext4_group_first_block_no(sb, 0) + EXT4_C2B(sbi, 1), found,
 288                 "failed to alloc block before goal group, expected %llu found %llu",
 289                 ext4_group_first_block_no(sb, 0 + EXT4_C2B(sbi, 1)), found);
 290
 291         /* no block available, fail to allocate block */
 292         for (i = 0; i < ext4_get_groups_count(sb); i++)
 293                 mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
 294         ar.goal = ext4_group_first_block_no(sb, goal_group);
 295         found = ext4_mb_new_blocks_simple(&ar, &err);
 296         KUNIT_ASSERT_NE_MSG(test, err, 0,
 297                 "unexpectedly get block when no block is available");
 298 }
 299
 300 static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
 301         {
 302                 .blocksize_bits = 10,
 303                 .cluster_bits = 3,
 304                 .blocks_per_group = 8192,
 305                 .group_count = 4,
 306                 .desc_size = 64,
 307         },
 308         {
 309                 .blocksize_bits = 12,
 310                 .cluster_bits = 3,
 311                 .blocks_per_group = 8192,
 312                 .group_count = 4,
 313                 .desc_size = 64,
 314         },
 315         {
 316                 .blocksize_bits = 16,
 317                 .cluster_bits = 3,
 318                 .blocks_per_group = 8192,
 319                 .group_count = 4,
 320                 .desc_size = 64,
 321         },
 322 };
 323
 324 static void mbt_show_layout(const struct mbt_ext4_block_layout *layout,
 325                             char *desc)
 326 {
 327         snprintf(desc, KUNIT_PARAM_DESC_SIZE, "block_bits=%d cluster_bits=%d "
 328                  "blocks_per_group=%d group_count=%d desc_size=%d\n",
 329                  layout->blocksize_bits, layout->cluster_bits,
 330                  layout->blocks_per_group, layout->group_count,
 331                  layout->desc_size);
 332 }
 333 KUNIT_ARRAY_PARAM(mbt_layouts, mbt_test_layouts, mbt_show_layout);
 334
 335 static struct kunit_case mbt_test_cases[] = {
 336         KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
 337         {}
 338 };
 339
 340 static struct kunit_suite mbt_test_suite = {
 341         .name = "ext4_mballoc_test",
 342         .init = mbt_kunit_init,
 343         .exit = mbt_kunit_exit,
 344         .test_cases = mbt_test_cases,
 345 };
 346
 347 kunit_test_suites(&mbt_test_suite);
 348
 349 MODULE_LICENSE("GPL");