Re: [PATCH] Btrfs: make sure fs_info is not null before its field is used in __btrfs_panic

[Li Zefan <lizefan@huawei.com>]

On 2012/12/7 23:42, Wang Sheng-Hui wrote:
> We should make sure fs_info is not null before we refer to its field.
> Add simple check here.

Why? Is there any caller passing NULL @fs_info to this function?

> 
> Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
> ---
>  fs/btrfs/super.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 915ac14..c6a3633 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -280,7 +280,7 @@ void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
>  	vaf.va = &args;
>  
>  	errstr = btrfs_decode_error(fs_info, errno, nbuf);
> -	if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)
> +	if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
>  		panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
>  			s_id, function, line, &vaf, errstr);
>  
>