Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 1008 insertions, 0 deletions

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
new file mode 100644
index 000000000..d31780075
--- /dev/null
+++ b/fs/ext4/mballoc-test.c
@@ -0,0 +1,1008 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test of ext4 multiblocks allocation.
+ */
+
+#include <kunit/test.h>
+#include <kunit/static_stub.h>
+#include <linux/fs_context.h>
+#include <linux/random.h>
+
+#include "ext4.h"
+#include "mballoc.h"
+
+struct mbt_grp_ctx {
+	struct buffer_head bitmap_bh;
+	/* desc and gd_bh are just the place holders for now */
+	struct ext4_group_desc desc;
+	struct buffer_head gd_bh;
+};
+
+struct mbt_ctx {
+	struct mbt_grp_ctx *grp_ctx;
+};
+
+struct mbt_ext4_super_block {
+	struct ext4_super_block es;
+	struct ext4_sb_info sbi;
+	struct mbt_ctx mbt_ctx;
+};
+
+#define MBT_SB(_sb) (container_of((_sb)->s_fs_info, struct mbt_ext4_super_block, sbi))
+#define MBT_CTX(_sb) (&MBT_SB(_sb)->mbt_ctx)
+#define MBT_GRP_CTX(_sb, _group) (&MBT_CTX(_sb)->grp_ctx[_group])
+
+static struct inode *mbt_alloc_inode(struct super_block *sb)
+{
+	struct ext4_inode_info *ei;
+
+	ei = kmalloc_obj(struct ext4_inode_info);
+	if (!ei)
+		return NULL;
+
+	INIT_LIST_HEAD(&ei->i_orphan);
+	init_rwsem(&ei->xattr_sem);
+	init_rwsem(&ei->i_data_sem);
+	inode_init_once(&ei->vfs_inode);
+	ext4_fc_init_inode(&ei->vfs_inode);
+
+	return &ei->vfs_inode;
+}
+
+static void mbt_free_inode(struct inode *inode)
+{
+	kfree(EXT4_I(inode));
+}
+
+static const struct super_operations mbt_sops = {
+	.alloc_inode	= mbt_alloc_inode,
+	.free_inode	= mbt_free_inode,
+};
+
+static int mbt_init_fs_context(struct fs_context *fc)
+{
+	return 0;
+}
+
+static struct file_system_type mbt_fs_type = {
+	.name			= "mballoc test",
+	.init_fs_context	= mbt_init_fs_context,
+	.kill_sb		= kill_anon_super,
+};
+
+static int mbt_mb_init(struct super_block *sb)
+{
+	ext4_fsblk_t block;
+	int ret;
+
+	/* needed by ext4_mb_init->bdev_rot(sb->s_bdev) */
+	sb->s_bdev = kzalloc_obj(*sb->s_bdev);
+	if (sb->s_bdev == NULL)
+		return -ENOMEM;
+
+	sb->s_bdev->bd_queue = kzalloc_obj(struct request_queue);
+	if (sb->s_bdev->bd_queue == NULL) {
+		kfree(sb->s_bdev);
+		return -ENOMEM;
+	}
+
+	/*
+	 * needed by ext4_mb_init->ext4_mb_init_backend-> sbi->s_buddy_cache =
+	 * new_inode(sb);
+	 */
+	INIT_LIST_HEAD(&sb->s_inodes);
+	sb->s_op = &mbt_sops;
+
+	ret = ext4_mb_init(sb);
+	if (ret != 0)
+		goto err_out;
+
+	block = ext4_count_free_clusters(sb);
+	ret = percpu_counter_init(&EXT4_SB(sb)->s_freeclusters_counter, block,
+				  GFP_KERNEL);
+	if (ret != 0)
+		goto err_mb_release;
+
+	ret = percpu_counter_init(&EXT4_SB(sb)->s_dirtyclusters_counter, 0,
+				  GFP_KERNEL);
+	if (ret != 0)
+		goto err_freeclusters;
+
+	return 0;
+
+err_freeclusters:
+	percpu_counter_destroy(&EXT4_SB(sb)->s_freeclusters_counter);
+err_mb_release:
+	ext4_mb_release(sb);
+err_out:
+	kfree(sb->s_bdev->bd_queue);
+	kfree(sb->s_bdev);
+	return ret;
+}
+
+static void mbt_mb_release(struct super_block *sb)
+{
+	percpu_counter_destroy(&EXT4_SB(sb)->s_dirtyclusters_counter);
+	percpu_counter_destroy(&EXT4_SB(sb)->s_freeclusters_counter);
+	ext4_mb_release(sb);
+	kfree(sb->s_bdev->bd_queue);
+	kfree(sb->s_bdev);
+}
+
+static int mbt_set(struct super_block *sb, struct fs_context *fc)
+{
+	return set_anon_super_fc(sb, fc);
+}
+
+static struct super_block *mbt_ext4_alloc_super_block(void)
+{
+	struct mbt_ext4_super_block *fsb;
+	struct super_block *sb;
+	struct fs_context *fc;
+	struct ext4_sb_info *sbi;
+
+	fsb = kzalloc_obj(*fsb);
+	if (fsb == NULL)
+		return NULL;
+
+	fc = fs_context_for_mount(&mbt_fs_type, 0);
+	if (IS_ERR(fc))
+		goto out;
+
+	sb = sget_fc(fc, NULL, mbt_set);
+	put_fs_context(fc);
+	if (IS_ERR(sb))
+		goto out;
+
+	sbi = &fsb->sbi;
+
+	sbi->s_blockgroup_lock =
+		kzalloc_obj(struct blockgroup_lock);
+	if (!sbi->s_blockgroup_lock)
+		goto out_deactivate;
+
+	bgl_lock_init(sbi->s_blockgroup_lock);
+
+	sbi->s_es = &fsb->es;
+	sbi->s_sb = sb;
+	sb->s_fs_info = sbi;
+
+	up_write(&sb->s_umount);
+	return sb;
+
+out_deactivate:
+	deactivate_locked_super(sb);
+out:
+	kfree(fsb);
+	return NULL;
+}
+
+static void mbt_ext4_free_super_block(struct super_block *sb)
+{
+	struct mbt_ext4_super_block *fsb = MBT_SB(sb);
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	kfree(sbi->s_blockgroup_lock);
+	deactivate_super(sb);
+	kfree(fsb);
+}
+
+struct mbt_ext4_block_layout {
+	unsigned char blocksize_bits;
+	unsigned int cluster_bits;
+	uint32_t blocks_per_group;
+	ext4_group_t group_count;
+	uint16_t desc_size;
+};
+
+static void mbt_init_sb_layout(struct super_block *sb,
+			       struct mbt_ext4_block_layout *layout)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+
+	sb->s_blocksize = 1UL << layout->blocksize_bits;
+	sb->s_blocksize_bits = layout->blocksize_bits;
+
+	sbi->s_groups_count = layout->group_count;
+	sbi->s_blocks_per_group = layout->blocks_per_group;
+	sbi->s_cluster_bits = layout->cluster_bits;
+	sbi->s_cluster_ratio = 1U << layout->cluster_bits;
+	sbi->s_clusters_per_group = layout->blocks_per_group >>
+				    layout->cluster_bits;
+	sbi->s_desc_size = layout->desc_size;
+	sbi->s_desc_per_block_bits =
+		sb->s_blocksize_bits - (fls(layout->desc_size) - 1);
+	sbi->s_desc_per_block = 1 << sbi->s_desc_per_block_bits;
+
+	es->s_first_data_block = cpu_to_le32(0);
+	es->s_blocks_count_lo = cpu_to_le32(layout->blocks_per_group *
+					    layout->group_count);
+}
+
+static int mbt_grp_ctx_init(struct super_block *sb,
+			    struct mbt_grp_ctx *grp_ctx)
+{
+	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
+
+	grp_ctx->bitmap_bh.b_data = kzalloc(EXT4_BLOCK_SIZE(sb), GFP_KERNEL);
+	if (grp_ctx->bitmap_bh.b_data == NULL)
+		return -ENOMEM;
+	mb_set_bits(grp_ctx->bitmap_bh.b_data, max, sb->s_blocksize * 8 - max);
+	ext4_free_group_clusters_set(sb, &grp_ctx->desc, max);
+
+	return 0;
+}
+
+static void mbt_grp_ctx_release(struct mbt_grp_ctx *grp_ctx)
+{
+	kfree(grp_ctx->bitmap_bh.b_data);
+	grp_ctx->bitmap_bh.b_data = NULL;
+}
+
+static void mbt_ctx_mark_used(struct super_block *sb, ext4_group_t group,
+			      unsigned int start, unsigned int len)
+{
+	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
+
+	mb_set_bits(grp_ctx->bitmap_bh.b_data, start, len);
+}
+
+static void *mbt_ctx_bitmap(struct super_block *sb, ext4_group_t group)
+{
+	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
+
+	return grp_ctx->bitmap_bh.b_data;
+}
+
+/* called after mbt_init_sb_layout */
+static int mbt_ctx_init(struct super_block *sb)
+{
+	struct mbt_ctx *ctx = MBT_CTX(sb);
+	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+
+	ctx->grp_ctx = kzalloc_objs(struct mbt_grp_ctx, ngroups);
+	if (ctx->grp_ctx == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < ngroups; i++)
+		if (mbt_grp_ctx_init(sb, &ctx->grp_ctx[i]))
+			goto out;
+
+	/*
+	 * first data block(first cluster in first group) is used by
+	 * metadata, mark it used to avoid to alloc data block at first
+	 * block which will fail ext4_sb_block_valid check.
+	 */
+	mb_set_bits(ctx->grp_ctx[0].bitmap_bh.b_data, 0, 1);
+	ext4_free_group_clusters_set(sb, &ctx->grp_ctx[0].desc,
+				     EXT4_CLUSTERS_PER_GROUP(sb) - 1);
+
+	return 0;
+out:
+	while (i-- > 0)
+		mbt_grp_ctx_release(&ctx->grp_ctx[i]);
+	kfree(ctx->grp_ctx);
+	return -ENOMEM;
+}
+
+static void mbt_ctx_release(struct super_block *sb)
+{
+	struct mbt_ctx *ctx = MBT_CTX(sb);
+	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+
+	for (i = 0; i < ngroups; i++)
+		mbt_grp_ctx_release(&ctx->grp_ctx[i]);
+	kfree(ctx->grp_ctx);
+}
+
+static struct buffer_head *
+ext4_read_block_bitmap_nowait_stub(struct super_block *sb, ext4_group_t block_group,
+				   bool ignore_locked)
+{
+	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
+
+	/* paired with brelse from caller of ext4_read_block_bitmap_nowait */
+	get_bh(&grp_ctx->bitmap_bh);
+	return &grp_ctx->bitmap_bh;
+}
+
+static int ext4_wait_block_bitmap_stub(struct super_block *sb,
+				       ext4_group_t block_group,
+				       struct buffer_head *bh)
+{
+	/*
+	 * real ext4_wait_block_bitmap will set these flags and
+	 * functions like ext4_mb_init_cache will verify the flags.
+	 */
+	set_buffer_uptodate(bh);
+	set_bitmap_uptodate(bh);
+	set_buffer_verified(bh);
+	return 0;
+}
+
+static struct ext4_group_desc *
+ext4_get_group_desc_stub(struct super_block *sb, ext4_group_t block_group,
+			 struct buffer_head **bh)
+{
+	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, block_group);
+
+	if (bh != NULL)
+		*bh = &grp_ctx->gd_bh;
+
+	return &grp_ctx->desc;
+}
+
+static int
+ext4_mb_mark_context_stub(handle_t *handle, struct super_block *sb, bool state,
+			  ext4_group_t group, ext4_grpblk_t blkoff,
+			  ext4_grpblk_t len, int flags,
+			  ext4_grpblk_t *ret_changed)
+{
+	struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
+	struct buffer_head *bitmap_bh = &grp_ctx->bitmap_bh;
+
+	if (state)
+		mb_set_bits(bitmap_bh->b_data, blkoff, len);
+	else
+		mb_clear_bits_test(bitmap_bh->b_data, blkoff, len);
+
+	return 0;
+}
+
+#define TEST_GOAL_GROUP 1
+static int mbt_kunit_init(struct kunit *test)
+{
+	struct mbt_ext4_block_layout *layout =
+		(struct mbt_ext4_block_layout *)(test->param_value);
+	struct super_block *sb;
+	int ret;
+
+	sb = mbt_ext4_alloc_super_block();
+	if (sb == NULL)
+		return -ENOMEM;
+
+	mbt_init_sb_layout(sb, layout);
+
+	ret = mbt_ctx_init(sb);
+	if (ret != 0) {
+		mbt_ext4_free_super_block(sb);
+		return ret;
+	}
+
+	kunit_activate_static_stub(test,
+				   ext4_read_block_bitmap_nowait,
+				   ext4_read_block_bitmap_nowait_stub);
+	kunit_activate_static_stub(test,
+				   ext4_wait_block_bitmap,
+				   ext4_wait_block_bitmap_stub);
+	kunit_activate_static_stub(test,
+				   ext4_get_group_desc,
+				   ext4_get_group_desc_stub);
+	kunit_activate_static_stub(test,
+				   ext4_mb_mark_context,
+				   ext4_mb_mark_context_stub);
+
+	/* stub function will be called in mbt_mb_init->ext4_mb_init */
+	if (mbt_mb_init(sb) != 0) {
+		mbt_ctx_release(sb);
+		mbt_ext4_free_super_block(sb);
+		return -ENOMEM;
+	}
+
+	test->priv = sb;
+
+	return 0;
+}
+
+static void mbt_kunit_exit(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+
+	if (!sb)
+		return;
+
+	mbt_mb_release(sb);
+	mbt_ctx_release(sb);
+	mbt_ext4_free_super_block(sb);
+}
+
+static void test_new_blocks_simple(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct inode *inode;
+	struct ext4_allocation_request ar;
+	ext4_group_t i, goal_group = TEST_GOAL_GROUP;
+	int err = 0;
+	ext4_fsblk_t found;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	inode = kunit_kzalloc(test, sizeof(*inode), GFP_KERNEL);
+	if (!inode)
+		return;
+
+	inode->i_sb = sb;
+	ar.inode = inode;
+
+	/* get block at goal */
+	ar.goal = ext4_group_first_block_no(sb, goal_group);
+	found = ext4_mb_new_blocks_simple_test(&ar, &err);
+	KUNIT_ASSERT_EQ_MSG(test, ar.goal, found,
+		"failed to alloc block at goal, expected %llu found %llu",
+		ar.goal, found);
+
+	/* get block after goal in goal group */
+	ar.goal = ext4_group_first_block_no(sb, goal_group);
+	found = ext4_mb_new_blocks_simple_test(&ar, &err);
+	KUNIT_ASSERT_EQ_MSG(test, ar.goal + EXT4_C2B(sbi, 1), found,
+		"failed to alloc block after goal in goal group, expected %llu found %llu",
+		ar.goal + 1, found);
+
+	/* get block after goal group */
+	mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
+	ar.goal = ext4_group_first_block_no(sb, goal_group);
+	found = ext4_mb_new_blocks_simple_test(&ar, &err);
+	KUNIT_ASSERT_EQ_MSG(test,
+		ext4_group_first_block_no(sb, goal_group + 1), found,
+		"failed to alloc block after goal group, expected %llu found %llu",
+		ext4_group_first_block_no(sb, goal_group + 1), found);
+
+	/* get block before goal group */
+	for (i = goal_group; i < ext4_get_groups_count(sb); i++)
+		mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
+	ar.goal = ext4_group_first_block_no(sb, goal_group);
+	found = ext4_mb_new_blocks_simple_test(&ar, &err);
+	KUNIT_ASSERT_EQ_MSG(test,
+		ext4_group_first_block_no(sb, 0) + EXT4_C2B(sbi, 1), found,
+		"failed to alloc block before goal group, expected %llu found %llu",
+		ext4_group_first_block_no(sb, 0 + EXT4_C2B(sbi, 1)), found);
+
+	/* no block available, fail to allocate block */
+	for (i = 0; i < ext4_get_groups_count(sb); i++)
+		mbt_ctx_mark_used(sb, i, 0, EXT4_CLUSTERS_PER_GROUP(sb));
+	ar.goal = ext4_group_first_block_no(sb, goal_group);
+	found = ext4_mb_new_blocks_simple_test(&ar, &err);
+	KUNIT_ASSERT_NE_MSG(test, err, 0,
+		"unexpectedly get block when no block is available");
+}
+
+#define TEST_RANGE_COUNT 8
+
+struct test_range {
+	ext4_grpblk_t start;
+	ext4_grpblk_t len;
+};
+
+static void
+mbt_generate_test_ranges(struct super_block *sb, struct test_range *ranges,
+			 int count)
+{
+	ext4_grpblk_t start, len, max;
+	int i;
+
+	max = EXT4_CLUSTERS_PER_GROUP(sb) / count;
+	for (i = 0; i < count; i++) {
+		start = get_random_u32() % max;
+		len = get_random_u32() % max;
+		len = min(len, max - start);
+
+		ranges[i].start = start + i * max;
+		ranges[i].len = len;
+	}
+}
+
+static void
+validate_free_blocks_simple(struct kunit *test, struct super_block *sb,
+			    ext4_group_t goal_group, ext4_grpblk_t start,
+			    ext4_grpblk_t len)
+{
+	void *bitmap;
+	ext4_grpblk_t bit, max = EXT4_CLUSTERS_PER_GROUP(sb);
+	ext4_group_t i;
+
+	for (i = 0; i < ext4_get_groups_count(sb); i++) {
+		if (i == goal_group)
+			continue;
+
+		bitmap = mbt_ctx_bitmap(sb, i);
+		bit = mb_find_next_zero_bit_test(bitmap, max, 0);
+		KUNIT_ASSERT_EQ_MSG(test, bit, max,
+				    "free block on unexpected group %d", i);
+	}
+
+	bitmap = mbt_ctx_bitmap(sb, goal_group);
+	bit = mb_find_next_zero_bit_test(bitmap, max, 0);
+	KUNIT_ASSERT_EQ(test, bit, start);
+
+	bit = mb_find_next_bit_test(bitmap, max, bit + 1);
+	KUNIT_ASSERT_EQ(test, bit, start + len);
+}
+
+static void
+test_free_blocks_simple_range(struct kunit *test, ext4_group_t goal_group,
+			      ext4_grpblk_t start, ext4_grpblk_t len)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct inode *inode;
+	ext4_fsblk_t block;
+
+	inode = kunit_kzalloc(test, sizeof(*inode), GFP_KERNEL);
+	if (!inode)
+		return;
+	inode->i_sb = sb;
+
+	if (len == 0)
+		return;
+
+	block = ext4_group_first_block_no(sb, goal_group) +
+		EXT4_C2B(sbi, start);
+	ext4_free_blocks_simple_test(inode, block, len);
+	validate_free_blocks_simple(test, sb, goal_group, start, len);
+	mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
+}
+
+static void test_free_blocks_simple(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
+	ext4_group_t i;
+	struct test_range ranges[TEST_RANGE_COUNT];
+
+	for (i = 0; i < ext4_get_groups_count(sb); i++)
+		mbt_ctx_mark_used(sb, i, 0, max);
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_free_blocks_simple_range(test, TEST_GOAL_GROUP,
+			ranges[i].start, ranges[i].len);
+}
+
+static void
+test_mark_diskspace_used_range(struct kunit *test,
+			       struct ext4_allocation_context *ac,
+			       ext4_grpblk_t start,
+			       ext4_grpblk_t len)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	int ret;
+	void *bitmap;
+	ext4_grpblk_t i, max;
+
+	/* ext4_mb_mark_diskspace_used will BUG if len is 0 */
+	if (len == 0)
+		return;
+
+	ac->ac_b_ex.fe_group = TEST_GOAL_GROUP;
+	ac->ac_b_ex.fe_start = start;
+	ac->ac_b_ex.fe_len = len;
+
+	bitmap = mbt_ctx_bitmap(sb, TEST_GOAL_GROUP);
+	memset(bitmap, 0, sb->s_blocksize);
+	ret = ext4_mb_mark_diskspace_used_test(ac, NULL);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	max = EXT4_CLUSTERS_PER_GROUP(sb);
+	i = mb_find_next_bit_test(bitmap, max, 0);
+	KUNIT_ASSERT_EQ(test, i, start);
+	i = mb_find_next_zero_bit_test(bitmap, max, i + 1);
+	KUNIT_ASSERT_EQ(test, i, start + len);
+	i = mb_find_next_bit_test(bitmap, max, i + 1);
+	KUNIT_ASSERT_EQ(test, max, i);
+}
+
+static void test_mark_diskspace_used(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct inode *inode;
+	struct ext4_allocation_context ac;
+	struct test_range ranges[TEST_RANGE_COUNT];
+	int i;
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+
+	inode = kunit_kzalloc(test, sizeof(*inode), GFP_KERNEL);
+	if (!inode)
+		return;
+	inode->i_sb = sb;
+
+	ac.ac_status = AC_STATUS_FOUND;
+	ac.ac_sb = sb;
+	ac.ac_inode = inode;
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_mark_diskspace_used_range(test, &ac, ranges[i].start,
+					       ranges[i].len);
+}
+
+static void mbt_generate_buddy(struct super_block *sb, void *buddy,
+			       void *bitmap, struct ext4_group_info *grp)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	uint32_t order, off;
+	void *bb, *bb_h;
+	int max;
+
+	memset(buddy, 0xff, sb->s_blocksize);
+	memset(grp, 0, offsetof(struct ext4_group_info,
+				 bb_counters[MB_NUM_ORDERS(sb)]));
+
+	bb = bitmap;
+	max = EXT4_CLUSTERS_PER_GROUP(sb);
+	bb_h = buddy + sbi->s_mb_offsets[1];
+
+	off = mb_find_next_zero_bit_test(bb, max, 0);
+	grp->bb_first_free = off;
+	while (off < max) {
+		grp->bb_counters[0]++;
+		grp->bb_free++;
+
+		if (!(off & 1) && !mb_test_bit_test(off + 1, bb)) {
+			grp->bb_free++;
+			grp->bb_counters[0]--;
+			mb_clear_bit_test(off >> 1, bb_h);
+			grp->bb_counters[1]++;
+			grp->bb_largest_free_order = 1;
+			off++;
+		}
+
+		off = mb_find_next_zero_bit_test(bb, max, off + 1);
+	}
+
+	for (order = 1; order < MB_NUM_ORDERS(sb) - 1; order++) {
+		bb = buddy + sbi->s_mb_offsets[order];
+		bb_h = buddy + sbi->s_mb_offsets[order + 1];
+		max = max >> 1;
+		off = mb_find_next_zero_bit_test(bb, max, 0);
+
+		while (off < max) {
+			if (!(off & 1) && !mb_test_bit_test(off + 1, bb)) {
+				mb_set_bits(bb, off, 2);
+				grp->bb_counters[order] -= 2;
+				mb_clear_bit_test(off >> 1, bb_h);
+				grp->bb_counters[order + 1]++;
+				grp->bb_largest_free_order = order + 1;
+				off++;
+			}
+
+			off = mb_find_next_zero_bit_test(bb, max, off + 1);
+		}
+	}
+
+	max = EXT4_CLUSTERS_PER_GROUP(sb);
+	off = mb_find_next_zero_bit_test(bitmap, max, 0);
+	while (off < max) {
+		grp->bb_fragments++;
+
+		off = mb_find_next_bit_test(bitmap, max, off + 1);
+		if (off + 1 >= max)
+			break;
+
+		off = mb_find_next_zero_bit_test(bitmap, max, off + 1);
+	}
+}
+
+static void
+mbt_validate_group_info(struct kunit *test, struct ext4_group_info *grp1,
+			struct ext4_group_info *grp2)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	int i;
+
+	KUNIT_ASSERT_EQ(test, grp1->bb_first_free,
+			grp2->bb_first_free);
+	KUNIT_ASSERT_EQ(test, grp1->bb_fragments,
+			grp2->bb_fragments);
+	KUNIT_ASSERT_EQ(test, grp1->bb_free, grp2->bb_free);
+	KUNIT_ASSERT_EQ(test, grp1->bb_largest_free_order,
+			grp2->bb_largest_free_order);
+
+	for (i = 1; i < MB_NUM_ORDERS(sb); i++) {
+		KUNIT_ASSERT_EQ_MSG(test, grp1->bb_counters[i],
+				    grp2->bb_counters[i],
+				    "bb_counters[%d] diffs, expected %d, generated %d",
+				    i, grp1->bb_counters[i],
+				    grp2->bb_counters[i]);
+	}
+}
+
+static void
+do_test_generate_buddy(struct kunit *test, struct super_block *sb, void *bitmap,
+			   void *mbt_buddy, struct ext4_group_info *mbt_grp,
+			   void *ext4_buddy, struct ext4_group_info *ext4_grp)
+{
+	int i;
+
+	mbt_generate_buddy(sb, mbt_buddy, bitmap, mbt_grp);
+
+	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
+		ext4_grp->bb_counters[i] = 0;
+	/* needed by validation in ext4_mb_generate_buddy */
+	ext4_grp->bb_free = mbt_grp->bb_free;
+	memset(ext4_buddy, 0xff, sb->s_blocksize);
+	ext4_mb_generate_buddy_test(sb, ext4_buddy, bitmap, TEST_GOAL_GROUP,
+			       ext4_grp);
+
+	KUNIT_ASSERT_MEMEQ(test, mbt_buddy, ext4_buddy, sb->s_blocksize);
+	mbt_validate_group_info(test, mbt_grp, ext4_grp);
+}
+
+static void test_mb_generate_buddy(struct kunit *test)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	void *bitmap, *expected_bb, *generate_bb;
+	struct ext4_group_info *expected_grp, *generate_grp;
+	struct test_range ranges[TEST_RANGE_COUNT];
+	int i;
+
+	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
+	expected_bb = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_bb);
+	generate_bb = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, generate_bb);
+	expected_grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
+				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_grp);
+	generate_grp = ext4_get_group_info(sb, TEST_GOAL_GROUP);
+	KUNIT_ASSERT_NOT_NULL(test, generate_grp);
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++) {
+		mb_set_bits(bitmap, ranges[i].start, ranges[i].len);
+		do_test_generate_buddy(test, sb, bitmap, expected_bb,
+				       expected_grp, generate_bb, generate_grp);
+	}
+}
+
+static void
+test_mb_mark_used_range(struct kunit *test, struct ext4_buddy *e4b,
+			ext4_grpblk_t start, ext4_grpblk_t len, void *bitmap,
+			void *buddy, struct ext4_group_info *grp)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct ext4_free_extent ex;
+	int i;
+
+	/* mb_mark_used only accepts non-zero len */
+	if (len == 0)
+		return;
+
+	ex.fe_start = start;
+	ex.fe_len = len;
+	ex.fe_group = TEST_GOAL_GROUP;
+
+	ext4_lock_group(sb, TEST_GOAL_GROUP);
+	mb_mark_used_test(e4b, &ex);
+	ext4_unlock_group(sb, TEST_GOAL_GROUP);
+
+	mb_set_bits(bitmap, start, len);
+	/* bypass bb_free validatoin in ext4_mb_generate_buddy */
+	grp->bb_free -= len;
+	memset(buddy, 0xff, sb->s_blocksize);
+	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
+		grp->bb_counters[i] = 0;
+	ext4_mb_generate_buddy_test(sb, buddy, bitmap, 0, grp);
+
+	KUNIT_ASSERT_MEMEQ(test, buddy, e4b->bd_buddy, sb->s_blocksize);
+	mbt_validate_group_info(test, grp, e4b->bd_info);
+}
+
+static void test_mb_mark_used(struct kunit *test)
+{
+	struct ext4_buddy e4b;
+	struct super_block *sb = (struct super_block *)test->priv;
+	void *bitmap, *buddy;
+	struct ext4_group_info *grp;
+	int ret;
+	struct test_range ranges[TEST_RANGE_COUNT];
+	int i;
+
+	/* buddy cache assumes that each page contains at least one block */
+	if (sb->s_blocksize > PAGE_SIZE)
+		kunit_skip(test, "blocksize exceeds pagesize");
+
+	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
+	buddy = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy);
+	grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
+				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, grp);
+
+	ret = ext4_mb_load_buddy_test(sb, TEST_GOAL_GROUP, &e4b);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	grp->bb_free = EXT4_CLUSTERS_PER_GROUP(sb);
+	grp->bb_largest_free_order = -1;
+	grp->bb_avg_fragment_size_order = -1;
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_mb_mark_used_range(test, &e4b, ranges[i].start,
+					ranges[i].len, bitmap, buddy, grp);
+
+	ext4_mb_unload_buddy_test(&e4b);
+}
+
+static void
+test_mb_free_blocks_range(struct kunit *test, struct ext4_buddy *e4b,
+			  ext4_grpblk_t start, ext4_grpblk_t len, void *bitmap,
+			  void *buddy, struct ext4_group_info *grp)
+{
+	struct super_block *sb = (struct super_block *)test->priv;
+	int i;
+
+	/* mb_free_blocks will WARN if len is 0 */
+	if (len == 0)
+		return;
+
+	ext4_lock_group(sb, e4b->bd_group);
+	mb_free_blocks_test(NULL, e4b, start, len);
+	ext4_unlock_group(sb, e4b->bd_group);
+
+	mb_clear_bits_test(bitmap, start, len);
+	/* bypass bb_free validatoin in ext4_mb_generate_buddy */
+	grp->bb_free += len;
+	memset(buddy, 0xff, sb->s_blocksize);
+	for (i = 0; i < MB_NUM_ORDERS(sb); i++)
+		grp->bb_counters[i] = 0;
+	ext4_mb_generate_buddy_test(sb, buddy, bitmap, 0, grp);
+
+	KUNIT_ASSERT_MEMEQ(test, buddy, e4b->bd_buddy, sb->s_blocksize);
+	mbt_validate_group_info(test, grp, e4b->bd_info);
+
+}
+
+static void test_mb_free_blocks(struct kunit *test)
+{
+	struct ext4_buddy e4b;
+	struct super_block *sb = (struct super_block *)test->priv;
+	void *bitmap, *buddy;
+	struct ext4_group_info *grp;
+	struct ext4_free_extent ex;
+	int ret;
+	int i;
+	struct test_range ranges[TEST_RANGE_COUNT];
+
+	/* buddy cache assumes that each page contains at least one block */
+	if (sb->s_blocksize > PAGE_SIZE)
+		kunit_skip(test, "blocksize exceeds pagesize");
+
+	bitmap = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bitmap);
+	buddy = kunit_kzalloc(test, sb->s_blocksize, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy);
+	grp = kunit_kzalloc(test, offsetof(struct ext4_group_info,
+				bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, grp);
+
+	ret = ext4_mb_load_buddy_test(sb, TEST_GOAL_GROUP, &e4b);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ex.fe_start = 0;
+	ex.fe_len = EXT4_CLUSTERS_PER_GROUP(sb);
+	ex.fe_group = TEST_GOAL_GROUP;
+
+	ext4_lock_group(sb, TEST_GOAL_GROUP);
+	mb_mark_used_test(&e4b, &ex);
+	ext4_unlock_group(sb, TEST_GOAL_GROUP);
+
+	grp->bb_free = 0;
+	grp->bb_largest_free_order = -1;
+	grp->bb_avg_fragment_size_order = -1;
+	memset(bitmap, 0xff, sb->s_blocksize);
+
+	mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+	for (i = 0; i < TEST_RANGE_COUNT; i++)
+		test_mb_free_blocks_range(test, &e4b, ranges[i].start,
+					  ranges[i].len, bitmap, buddy, grp);
+
+	ext4_mb_unload_buddy_test(&e4b);
+}
+
+#define COUNT_FOR_ESTIMATE 100000
+static void test_mb_mark_used_cost(struct kunit *test)
+{
+	struct ext4_buddy e4b;
+	struct super_block *sb = (struct super_block *)test->priv;
+	struct ext4_free_extent ex;
+	int ret;
+	struct test_range ranges[TEST_RANGE_COUNT];
+	int i, j;
+	unsigned long start, end, all = 0;
+
+	/* buddy cache assumes that each page contains at least one block */
+	if (sb->s_blocksize > PAGE_SIZE)
+		kunit_skip(test, "blocksize exceeds pagesize");
+
+	ret = ext4_mb_load_buddy_test(sb, TEST_GOAL_GROUP, &e4b);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ex.fe_group = TEST_GOAL_GROUP;
+	for (j = 0; j < COUNT_FOR_ESTIMATE; j++) {
+		mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+		start = jiffies;
+		for (i = 0; i < TEST_RANGE_COUNT; i++) {
+			if (ranges[i].len == 0)
+				continue;
+
+			ex.fe_start = ranges[i].start;
+			ex.fe_len = ranges[i].len;
+			ext4_lock_group(sb, TEST_GOAL_GROUP);
+			mb_mark_used_test(&e4b, &ex);
+			ext4_unlock_group(sb, TEST_GOAL_GROUP);
+		}
+		end = jiffies;
+		all += (end - start);
+
+		for (i = 0; i < TEST_RANGE_COUNT; i++) {
+			if (ranges[i].len == 0)
+				continue;
+
+			ext4_lock_group(sb, TEST_GOAL_GROUP);
+			mb_free_blocks_test(NULL, &e4b, ranges[i].start,
+				       ranges[i].len);
+			ext4_unlock_group(sb, TEST_GOAL_GROUP);
+		}
+	}
+
+	kunit_info(test, "costed jiffies %lu\n", all);
+	ext4_mb_unload_buddy_test(&e4b);
+}
+
+static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
+	{
+		.blocksize_bits = 10,
+		.cluster_bits = 3,
+		.blocks_per_group = 8192,
+		.group_count = 4,
+		.desc_size = 64,
+	},
+	{
+		.blocksize_bits = 12,
+		.cluster_bits = 3,
+		.blocks_per_group = 8192,
+		.group_count = 4,
+		.desc_size = 64,
+	},
+	{
+		.blocksize_bits = 16,
+		.cluster_bits = 3,
+		.blocks_per_group = 8192,
+		.group_count = 4,
+		.desc_size = 64,
+	},
+};
+
+static void mbt_show_layout(const struct mbt_ext4_block_layout *layout,
+			    char *desc)
+{
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "block_bits=%d cluster_bits=%d "
+		 "blocks_per_group=%d group_count=%d desc_size=%d\n",
+		 layout->blocksize_bits, layout->cluster_bits,
+		 layout->blocks_per_group, layout->group_count,
+		 layout->desc_size);
+}
+KUNIT_ARRAY_PARAM(mbt_layouts, mbt_test_layouts, mbt_show_layout);
+
+static struct kunit_case mbt_test_cases[] = {
+	KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_free_blocks_simple, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mb_generate_buddy, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mb_mark_used, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mb_free_blocks, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM(test_mark_diskspace_used, mbt_layouts_gen_params),
+	KUNIT_CASE_PARAM_ATTR(test_mb_mark_used_cost, mbt_layouts_gen_params,
+			      { .speed = KUNIT_SPEED_SLOW }),
+	{}
+};
+
+static struct kunit_suite mbt_test_suite = {
+	.name = "ext4_mballoc_test",
+	.init = mbt_kunit_init,
+	.exit = mbt_kunit_exit,
+	.test_cases = mbt_test_cases,
+};
+
+kunit_test_suites(&mbt_test_suite);
+
+MODULE_LICENSE("GPL");