Re: [PATCH 4.19 166/422] f2fs: fix memory leak of percpu counter in fill_super()

Hi!

From: Chao Yu yuchao0@huawei.com

[ Upstream commit 4a70e255449c9a13eed7a6eeecc85a1ea63cef76 ]

In fill_super -> init_percpu_info, we should destroy percpu counter in error path, otherwise memory allcoated for percpu counter will leak.

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 58931d55dc1d2..c5d28e92d146e 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2516,8 +2516,12 @@ static int init_percpu_info(struct f2fs_sb_info *sbi) if (err) return err;

• return percpu_counter_init(&sbi->total_valid_inode_count, 0,

• err = percpu_counter_init(&sbi->total_valid_inode_count, 0, GFP_KERNEL);
• if (err)

• percpu_counter_destroy(&sbi->alloc_valid_block_count);
  

• return err;

}

Are you sure this is good idea? Normally when _init() fails, the thing is not allocated, and there is nothing to destroy...

If you are right, there's same bug in fs/xfs/xfs_buf.c .

Best regards, Pavel