Re: [PATCH] btrfs-progs: fix btrfs quota rescan failed on PPC64 arch

[Eric Sandeen <sandeen@redhat.com>]

On 4/20/15 12:33 AM, xuw2015@gmail.com wrote:
> From: George Wang <xuw2015@gmail.com>
> 
> PPC64 arch use such following IOC values "
> \#define _IOC_NONE       1U
> \#define _IOC_READ       2U
> \#define _IOC_WRITE      4U
> " comparing to the default IOC values "
> \#define _IOC_NONE       0U
> \#define _IOC_READ       2U
> \#define _IOC_WRITE      1U"
> 
> This means the value "_IOW*" will be negative when we store it in the int
> variables. Such as the "BTRFS_IOC_QGROUP_CREATE", it will be "0x4010942e" on
> X86_64, but "0x8010942e" on PPC64.
> Notice that the IOC values are the "unsigned long" type, so we use the
> "unsigned long" to store it, and this can insure the comparison between the
> variable and BTRFS_IOC_* valid.

Looks good - very strange that the manpage states that the interface takes
an int.  :(  

But - an "unsigned int" would be enough, right?  I don't think it needs
to be an unsigned long.  *shrug*

Thanks,
-Eric

> Signed-off-by: George Wang <xuw2015@gmail.com>
> ---
>  cmds-quota.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/cmds-quota.c b/cmds-quota.c
> index 89cc89c..f6a1cfa 100644
> --- a/cmds-quota.c
> +++ b/cmds-quota.c
> @@ -109,7 +109,7 @@ static int cmd_quota_rescan(int argc, char **argv)
>  	int e;
>  	char *path = NULL;
>  	struct btrfs_ioctl_quota_rescan_args args;
> -	int ioctlnum = BTRFS_IOC_QUOTA_RESCAN;
> +	unsigned long ioctlnum = BTRFS_IOC_QUOTA_RESCAN;
>  	DIR *dirstream = NULL;
>  	int wait_for_completion = 0;
>  
>