raw-posix: Fetch max sectors for host block device

This is sometimes a useful value we should count in.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2016-06-03 10:07:02 +08:00 committed by Kevin Wolf
parent 107d433cbb
commit 6f6071745b

View file

@ -729,9 +729,33 @@ static void raw_reopen_abort(BDRVReopenState *state)
state->opaque = NULL;
}
static int hdev_get_max_transfer_length(int fd)
{
#ifdef BLKSECTGET
int max_sectors = 0;
if (ioctl(fd, BLKSECTGET, &max_sectors) == 0) {
return max_sectors;
} else {
return -errno;
}
#else
return -ENOSYS;
#endif
}
static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
{
BDRVRawState *s = bs->opaque;
struct stat st;
if (!fstat(s->fd, &st)) {
if (S_ISBLK(st.st_mode)) {
int ret = hdev_get_max_transfer_length(s->fd);
if (ret >= 0) {
bs->bl.max_transfer_length = ret;
}
}
}
raw_probe_alignment(bs, s->fd, errp);
bs->bl.min_mem_alignment = s->buf_align;