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Re: tstile syndrome

In article <>,
Jason Thorpe  <> wrote:
>On Sep 1, 2009, at 9:32 AM, David Holland wrote:
>> Such as? Please give clear examples. Moving the locks to below the VFS
>> layer does not change any of the ordering constraints or any of the
>> hard problems (vnode recycle, rename, etc.) but only forces cutting
>> and pasting 30 copies of what was previously FS-independent code into
>> every FS.
>Not true at all.  In Mac OS X, there is no exposed vnode-level locking  
>at the VFS layer or in the VFS<->file system interface.  Everything is  
>handled at the lower layers.  The reason that you don't end up copy- 
>pasting 30 copies, etc. is because it gives you a chance to dump the  
>completely irrational locking protocol that currently exists.

How do you handle fs layering then? Which layer handles the locking?


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