libblkid: reopen floppy without O_NONBLOCK

libblkid: reopen floppy without O_NONBLOCK

Vladimir Sementsov-Ogievskiy wrote:
> The commit "floppy: reintroduce O_NDELAY fix" was removed from kernel,
> so we faced the bug described and discussed here:
> https://bugzilla.suse.com/show_bug.cgi?id=3D1181018
>
> Discussion in kernel list on reverting the commit:
> https://www.spinics.net/lists/stable/msg493061.html
>
> In short, I can quote Jiri Kosina's comment:
>
>   opening floppy device node with O_NONBLOCK is asking for all kinds
>   of trouble
>
> So opening floppy with O_NONBLOCK in blkid leads to failure of blkid,
> probable failure of mount and unpleasant error messages in dmesg (see
> also patch 02 for details).

Based on patch from Vladimir.

CC: Jiri Kosina <jkosina@suse.cz>
Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Karel Zak <kzak@redhat.com>