On 20.03.2017 19:33, Peter Maydell wrote:
> On OpenBSD none of the ioctls probe_logical_blocksize() tries
> exist, so the variable sector_size is unused. Refactor the
> code to avoid this (and reduce the duplicated code).
>
> Signed-off-by: Peter Maydell
> ---
> The alternative would be to move the variable so it was
> local to a code block inside each #ifdef, but this seemed
> a bit nicer anyway.
>
> Tentatively tagged 'for-2.9' just because this is the only
> warning in the OpenBSD build, but I don't insist on it.
I'm fine with targeting 2.9.
> I've opted to retain the existing behaviour of "try every
> ioctl available and use the last one that works" rather
> than "stop as soon as something worked".
>
> ---
> block/file-posix.c | 28 ++--
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 53febd3..b980d23 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -219,28 +219,28 @@ static int probe_logical_blocksize(int fd, unsigned int
> *sector_size_p)
> {
> unsigned int sector_size;
> bool success = false;
> +int i;
>
> errno = ENOTSUP;
> -
> -/* Try a few ioctls to get the right size */
> +unsigned long ioctl_list[] = {
> #ifdef BLKSSZGET
> -if (ioctl(fd, BLKSSZGET, §or_size) >= 0) {
> -*sector_size_p = sector_size;
> -success = true;
> -}
> +BLKSSZGET,
> #endif
> #ifdef DKIOCGETBLOCKSIZE
> -if (ioctl(fd, DKIOCGETBLOCKSIZE, §or_size) >= 0) {
> -*sector_size_p = sector_size;
> -success = true;
> -}
> +DKIOCGETBLOCKSIZE,
> #endif
> #ifdef DIOCGSECTORSIZE
> -if (ioctl(fd, DIOCGSECTORSIZE, §or_size) >= 0) {
> -*sector_size_p = sector_size;
> -success = true;
> -}
> +DIOCGSECTORSIZE,
> #endif
> +};
> +
> +/* Try a few ioctls to get the right size */
> +for (i = 0; i < ARRAY_SIZE(ioctl_list); i++) {
On 32-bit, though:
./block/file-posix.c: In function ‘probe_logical_blocksize’:
./qemu/block/file-posix.c:229:19: error: comparison of unsigned
expression < 0 is always false [-Werror=type-limits]
A cast (int)ARRAY_SIZE() would fix that (I had the same problem once...).
Max
> +if (ioctl(fd, ioctl_list[i], §or_size) >= 0) {
> +*sector_size_p = sector_size;
> +success = true;
> +}
> +}
>
> return success ? 0 : -errno;
> }
>
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