[Stgt-devel] [PATCH] fix no blkgetsize64

[Arne Redlich]

Pete Wyckoff <pw at osc.edu> writes:

> Fix build for old machines that do not have 64-bit BLKGETSIZE.
>
> Signed-off-by: Pete Wyckoff <pw at osc.edu>
> ---
>  usr/util.c |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)
>
> diff --git a/usr/util.c b/usr/util.c
> index 9f54820..54bf399 100644
> --- a/usr/util.c
> +++ b/usr/util.c
> @@ -101,11 +101,21 @@ int backed_file_open(char *path, int oflag, uint64_t *size)
>  	if (S_ISREG(st.st_mode))
>  		*size = st.st_size;
>  	else if (S_ISBLK(st.st_mode)) {
> +#ifdef BLKGETSIZE64
>  		err = ioctl(fd, BLKGETSIZE64, size);
>  		if (err < 0) {
>  			eprintf("Cannot get size, %m\n");
>  			goto close_fd;
>  		}
> +#else
> +		unsigned long usize;
> +		err = ioctl(fd, BLKGETSIZE, &usize);
> +		if (err < 0) {
> +			eprintf("Cannot get size (ulong), %m\n");
> +			goto close_fd;
> +		}
> +		*size = usize;
> +#endif

Unfortunately there's a minor but nasty bug in here: BLKGETSIZE64 returns
the size in bytes, while BLKGETSIZE returns the number of sectors -
cf. linux/fs.h.

Arne