[PATCH] ext4: implement filesystem specific alloc_inode in unit test

From: Kemeng Shi
Date: Fri Mar 22 2024 - 03:59:21 EST


We expect inode with ext4_info_info type as following:
mbt_kunit_init
mbt_mb_init
ext4_mb_init
ext4_mb_init_backend
sbi->s_buddy_cache = new_inode(sb);
EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;

Implement alloc_inode ionde with ext4_inode_info type to avoid
out-of-bounds write.

Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
fs/ext4/mballoc-test.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index 044ca5238f41..49aabcfe6b46 100644
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -30,7 +30,31 @@ struct mbt_ext4_super_block {
#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(sizeof(struct ext4_inode_info), GFP_KERNEL);
+ 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 void mbt_kill_sb(struct super_block *sb)
--
2.30.0