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
11struct 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
18struct mbt_ctx {
19 struct mbt_grp_ctx *grp_ctx;
20};
21
22struct 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
30static struct super_block *mbt_ext4_alloc_super_block(void)
31{
32 struct ext4_super_block *es = kzalloc(size: sizeof(*es), GFP_KERNEL);
33 struct ext4_sb_info *sbi = kzalloc(size: sizeof(*sbi), GFP_KERNEL);
34 struct mbt_ext4_super_block *fsb = kzalloc(size: 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
43out:
44 kfree(objp: fsb);
45 kfree(objp: sbi);
46 kfree(objp: es);
47 return NULL;
48}
49
50static 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(objp: sbi->s_es);
57 kfree(objp: sbi);
58 kfree(objp: fsb);
59}
60
61struct 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
69static 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
91static 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
101static void mbt_grp_ctx_release(struct mbt_grp_ctx *grp_ctx)
102{
103 kfree(objp: grp_ctx->bitmap_bh.b_data);
104 grp_ctx->bitmap_bh.b_data = NULL;
105}
106
107static 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(bm: grp_ctx->bitmap_bh.b_data, cur: start, len);
113}
114
115/* called after mbt_init_sb_layout */
116static 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(n: ngroups, size: 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, grp_ctx: &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(bm: ctx->grp_ctx[0].bitmap_bh.b_data, cur: 0, len: 1);
136
137 return 0;
138out:
139 while (i-- > 0)
140 mbt_grp_ctx_release(grp_ctx: &ctx->grp_ctx[i]);
141 kfree(objp: ctx->grp_ctx);
142 return -ENOMEM;
143}
144
145static 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(grp_ctx: &ctx->grp_ctx[i]);
152 kfree(objp: ctx->grp_ctx);
153}
154
155static struct buffer_head *
156ext4_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(bh: &grp_ctx->bitmap_bh);
163 return &grp_ctx->bitmap_bh;
164}
165
166static 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
173static struct ext4_group_desc *
174ext4_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
185static int
186ext4_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(bm: bitmap_bh->b_data, cur: 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
203static 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
238static 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
246static 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, group_no: 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, group_no: 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, group: goal_group, start: 0, EXT4_CLUSTERS_PER_GROUP(sb));
274 ar.goal = ext4_group_first_block_no(sb, group_no: 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, group: i, start: 0, EXT4_CLUSTERS_PER_GROUP(sb));
284 ar.goal = ext4_group_first_block_no(sb, group_no: 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, group: i, start: 0, EXT4_CLUSTERS_PER_GROUP(sb));
294 ar.goal = ext4_group_first_block_no(sb, group_no: 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
300static 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
324static void mbt_show_layout(const struct mbt_ext4_block_layout *layout,
325 char *desc)
326{
327 snprintf(buf: desc, KUNIT_PARAM_DESC_SIZE, fmt: "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}
333KUNIT_ARRAY_PARAM(mbt_layouts, mbt_test_layouts, mbt_show_layout);
334
335static struct kunit_case mbt_test_cases[] = {
336 KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
337 {}
338};
339
340static 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
347kunit_test_suites(&mbt_test_suite);
348
349MODULE_LICENSE("GPL");
350

source code of linux/fs/ext4/mballoc-test.c