swap space in file on inconsystent file system

[steve%prd.co.uk@localhost (Steve Blinkhorn)]

I have a remote server (about to be replaced, but still in service and
needs to stay that way until a replacement is fully commissioned) that
has just developed a single bad sector.  The result has been that
automatic backups using rsync have failed, and manual intervention is
needed.

There are also numerous sleeping processes that refuse to be killed,
almost all in the 'tstile' state (this is i386 7.0).

#top

140 processes: 133 sleeping, 5 zombie, 2 on CPU
CPU states:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt, 100% idle
Memory: 107M Act, 63M Inact, 6968K Wired, 13M Exec, 11M File, 160M Free
Swap: 1128M Total, 345M Used, 783M Free

Most of the swap space is in a file on the file system concerned.

fsck -n on the other file systems shows a small handful of unreferenced
files in /var (a separate file system), but no other issues.

I need to get this machine into a sane condition without being able to
access it in single user mode (because there is no remote console
access).

How should I proceed?

-- 
Steve Blinkhorn <steve%prd.co.uk@localhost>