Re: [PATCH] ext4: Fix ERR_PTR(0) in ext4_mkdir()

[Zhang Yi]

On 5/20/2026 3:46 PM, Hongling Zeng wrote:
> When mkdir succeeds, ext4_mkdir() returns ERR_PTR(0) which is incorrect.
> It should return NULL instead for success and ERR_PTR() only with
> negative error codes for failure.

This point is indeed very easy to overlook. However, why not modify
other file systems as well? Commit 88d5baf69082 made changes not only
to ext4.

Thanks,
Yi.

> 
> Fixes: 88d5baf69082 ("Change inode_operations.mkdir to return struct dentry *")
> Signed-off-by: Hongling Zeng <zenghongling@xxxxxxxxxx>
> ---
>  fs/ext4/namei.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
> index 4a47fbd8dd30..8cadaeb15b2b 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -3054,7 +3054,7 @@ static struct dentry *ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir,
>  out_retry:
>  	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
>  		goto retry;
> -	return ERR_PTR(err);
> +	return err ? ERR_PTR(err) : NULL;
>  }
>  
>  /*