Re: [PATCH] FAT/exFAT: Fix wrong size detection for files > 4GB

[Andrei Borzenkov <arvidjaar@gmail.com>]

24.08.2016 16:36, Carlo Caione пишет:
> From: Carlo Caione <carlo@endlessm.com>
> 
> For exFAT the file size can be > 4GB. The 'grub_fat_data' is still
> marking the 'file_size' as grub_ssize_t that is always 32bit when
> compiling for i386-pc also when using exFAT.
> 
> This is causing a problem when trying to open in loopback a > 4GB file
> from an exFAT partition.
> 
> Fix this modifying the size of the 'file_size' according to the
> MODE_EXFAT define.
> 
> Signed-off-by: Carlo Caione <carlo@endlessm.com>
> ---
>  grub-core/fs/fat.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/grub-core/fs/fat.c b/grub-core/fs/fat.c
> index 79fe864..d5212c2 100644
> --- a/grub-core/fs/fat.c
> +++ b/grub-core/fs/fat.c
> @@ -183,7 +183,11 @@ struct grub_fat_data
>    grub_uint32_t num_clusters;
>  
>    grub_uint8_t attr;
> -  grub_ssize_t file_size;
> +#ifndef MODE_EXFAT
> +  grub_uint32_t file_size;
> +#else
> +  grub_uint64_t file_size;
> +#endif
>    grub_uint32_t file_cluster;
>    grub_uint32_t cur_cluster_num;
>    grub_uint32_t cur_cluster;
> 

Looks correct except I'd use conditon "ifdef MODE_EXFAT", negative
condition looks strange in such cases.