Re: Processes getting stuck in state tmpfs

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