apparent filesystem-related hangs

[Kris Kennaway]

On Sat, Apr 21, 2007 at 10:51:10PM -0400, Wes Morgan wrote:
> I have several filesystems built on top of a gconcat volume consisting of 
> 2 300gb and 1 500gb drive. The /usr partition constitutes the bulk of it. 
> The volume is sitting around 95% full, and twice I've had the system 
> become "hung" in what I believe are filesystem operations. It seems to 
> crop up when rtorrent tries to create files that would fill up the system, 
> but of course it doesn't actually reserve it until it is used. Any running 
> process remains responsive until it needs to access the disk.
> 
> The system was running a fairly recent 6.2-stable, March 29, but I've 
> since updated to the most recent -stable.
> 
> If anyone can give me some pointers as to how to tell exactly where these 
> processes are hanging, I can try to reproduce it... But it takes a while 
> to fsck the volume so I don't want to have to try too many things. If it's 
> not a known problem I can then submit a PR.


DEBUG_LOCKS, DEBUG_VFS_LOCKS, INVARIANTS, INVARIANT_SUPPORT, then
'show lockedvnods' and 'alltrace' from ddb via the serial console when
it hangs.

Kris