Re: [PATCH] fs: exfat: Fix corrupted error code handling in exfat_find_empty_entry()

[Sungjong Seo]

Hi, Haotian,

On 25. 12. 3. 16:08, Haotian Zhang wrote:
> exfat_find_empty_entry() stores the return value of
> exfat_alloc_cluster() in an unsigned int. When
> exfat_alloc_cluster() returns a negative errno, it is
> converted to a large positive value, which corrupts
> error propagation to the caller.
Have you ever encountered an actual error?
IMO, due to implicit type conversion, it should work as follows,
so, I don't think there will be any real issues.

int -> unsigned int -> int

Anyway, it makes sense to modify the type of ret from unsigned int to int.
What about changing the title and comment?

Thanks.
SJ

> 
> Change the type of ret to int so that negative errno
> values are preserved.
> 
> Fixes: 5f2aa075070c ("exfat: add inode operations")
> Signed-off-by: Haotian Zhang <vulab@xxxxxxxxxxx>
> ---
>  fs/exfat/namei.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
> index f5f1c4e8a29f..f2a87ecd79f9 100644
> --- a/fs/exfat/namei.c
> +++ b/fs/exfat/namei.c
> @@ -304,8 +304,8 @@ static int exfat_find_empty_entry(struct inode *inode,
>  		struct exfat_chain *p_dir, int num_entries,
>  		struct exfat_entry_set_cache *es)
>  {
> -	int dentry;
> -	unsigned int ret, last_clu;
> +	int dentry, ret;
> +	unsigned int last_clu;
>  	loff_t size = 0;
>  	struct exfat_chain clu;
>  	struct super_block *sb = inode->i_sb;