Description of problem:
write data to mount point after eject floppy in qemu-monitor cause floppy data lost 

Version-Release number of selected component (if applicable):


How reproducible:
100%

Steps to Reproduce:
1.start guest with floppy
eg:<commandLine> -drive file=/home/b.vfd,if=floppy,cache=none,format=raw
2.in the guest mount /dev/fd0 /mnt
3.mkdir /mnt/tt1 
4.mkdir /mnt/tt2
5.eject floppy in qemu-monitor (qemu)eject floppy0
6.umount /dev/fd0 in the guest #umount /dev/fd0
7,add floppy in qemu-monitor (qemu)change floppy0 /home/b.vfd
8.remount floppy  #mount /dev/fd0 /opt
  
Actual results:
two directories tt1 tt2 created in step 3/4 could not found in /dev/fd0

Expected results:
no data lost in floppy

Additional info: