Re: Processes getting stuck in state tmpfs

Could you test the patch attached.

It's also available here as seperate commits:
https://github.com/glk/freebsd-head/commits/tmpfs-rename

Thanks,
Gleb.

On (23/02/2012 21:20), Florian Smeets wrote:
> On 11.02.12 11:20, Gleb Kurtsou wrote:
> > On (10/02/2012 22:41), Florian Smeets wrote:
> >> Hi,
> >>
> >> if you set WRKDIRPREFIX to a tmpfs mountpoint and try to build audio/gsm
> >> from ports one of the mv processes gets stuck in state tmpfs quite
> >> often. Traces from a kernel with WITTNESS and DEBUG_VFS_LOCKS are
> >> available here http://tb.smeets.im/~flo/tmpfs.txt
> > 
> > It's because of incorrect vnode locking order in tmpfs_rename. Issue is
> > known and tmpfs is not the only file system suffering from it (e.g. ext2).
> > 
> > There two ways of working around it in tree:
> > * UFS: try locking vnode, unlock all vnodes on failure, restart,
> > relookup vnodes needed.
> > * ZFS: introduce directory entry locks to guarantee fvp won't disappear,
> > fdvp can be safely traversed, etc. That won't be easy..
> > 
> > UFS-way would be a good temporal solution, but I think we should work on
> > improving VOP_RENAME() in a long run.
> > 
> > I'll try to prepare a patch in several days.
> > 
> 
> Hey Gleb,
> 
> did you get anywhere with this?
> 
> Thanks,
> Florian
>