Comment 24 for bug 656526

This is not a problem which anyone else (using Fedora, Debian, etc) has complained about. Nor have I ever seen the problem on Lucid on my Goobuntu laptop running Lucid or Precise.

What I would suggest is that you download the e2fsprogs sources, and then after you build it, build lib/ext2fs/tst_ismounted

cd lib/ext2fs
make tst_ismounted

This is a debugging program which uses the mechanism used by e2fsprogrs to determine whether a device is busy or not:

# ./tst_ismounted /dev/closure/u1
Device /dev/closure/u1 reports flags 00
# mount /dev/closure/u1
# ./tst_ismounted /dev/closure/u1
Device /dev/closure/u1 reports flags 11
 /dev/closure/u1 is apparently in use.
 /dev/closure/u1 is mounted.
 /dev/closure/u1 is mounted on /u1.
# umount /dev/closure/u1
# e2fsck -f /dev/closure/u1
e2fsck 1.43-WIP (21-Sep-2012)
Pass 1: Checking inodes, blocks, and sizes
^Z
[1]+ Stopped e2fsck -f /dev/closure/u1
# ./tst_ismounted /dev/closure/u1
Device /dev/closure/u1 reports flags 10
 /dev/closure/u1 is apparently in use.

# ./tst_ismounted /dev/sdb1
Device /dev/sdb1 reports flags 13
 /dev/sdb1 is apparently in use.
 /dev/sdb1 is mounted.
 /dev/sdb1 is the root filesystem.
 /dev/sdb1 is mounted on /.

# ./tst_ismounted /dev/sdb5
Device /dev/sdb5 reports flags 19
 /dev/sdb5 is apparently in use.
 /dev/sdb5 is mounted.
 /dev/sdb5 is a swap device.
 /dev/sdb5 is mounted on <swap>.