ext4: fix the error handling process in extents_kunit_init).

The error processing in extents_kunit_init() is improper, causing
resource leakage.
Reconstruct the error handling process to prevent potential resource
leaks

Fixes: cb1e0c1 ("ext4: kunit tests for extent splitting and conversion")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20260330133035.287842-4-yebin@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Author: Ye Bin

fs/ext4/extents-test.c

@@ -225,34 +225,38 @@ static int extents_kunit_init(struct kunit *test)
 		(struct kunit_ext_test_param *)(test->param_value);
 	int err;
 
-	sb = sget(&ext_fs_type, NULL, ext_set, 0, NULL);
-	if (IS_ERR(sb))
-		return PTR_ERR(sb);
-
-	sb->s_blocksize = 4096;
-	sb->s_blocksize_bits = 12;
-
 	sbi = kzalloc_obj(struct ext4_sb_info);
 	if (sbi == NULL)
 		return -ENOMEM;
 
+	sb = sget(&ext_fs_type, NULL, ext_set, 0, NULL);
+	if (IS_ERR(sb)) {
+		kfree(sbi);
+		return PTR_ERR(sb);
+	}
+
 	sbi->s_sb = sb;
 	sb->s_fs_info = sbi;
 
+	sb->s_blocksize = 4096;
+	sb->s_blocksize_bits = 12;
+
 	if (!param || !param->disable_zeroout)
 		sbi->s_extent_max_zeroout_kb = 32;
 
+	err = ext4_es_register_shrinker(sbi);
+	if (err)
+		goto out_deactivate;
+
 	/* setup the mock inode */
 	k_ctx.k_ei = kzalloc_obj(struct ext4_inode_info);
-	if (k_ctx.k_ei == NULL)
-		return -ENOMEM;
+	if (k_ctx.k_ei == NULL) {
+		err = -ENOMEM;
+		goto out;
+	}
 	ei = k_ctx.k_ei;
 	inode = &ei->vfs_inode;
 
-	err = ext4_es_register_shrinker(sbi);
-	if (err)
-		return err;
-
 	ext4_es_init_tree(&ei->i_es_tree);
 	rwlock_init(&ei->i_es_lock);
 	INIT_LIST_HEAD(&ei->i_es_list);
@@ -267,8 +271,10 @@ static int extents_kunit_init(struct kunit *test)
 	inode->i_sb = sb;
 
 	k_ctx.k_data = kzalloc(EXT_DATA_LEN * 4096, GFP_KERNEL);
-	if (k_ctx.k_data == NULL)
-		return -ENOMEM;
+	if (k_ctx.k_data == NULL) {
+		err = -ENOMEM;
+		goto out;
+	}
 
 	/*
 	 * set the data area to a junk value
@@ -313,6 +319,20 @@ static int extents_kunit_init(struct kunit *test)
 	up_write(&sb->s_umount);
 
 	return 0;
+
+out:
+	kfree(k_ctx.k_ei);
+	k_ctx.k_ei = NULL;
+
+	kfree(k_ctx.k_data);
+	k_ctx.k_data = NULL;
+
+	ext4_es_unregister_shrinker(sbi);
+out_deactivate:
+	deactivate_locked_super(sb);
+	kfree(sbi);
+
+	return err;
 }
 
 /*