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Re: Layered fs, vnode locking and v_vnlock removal

On Wed, Jun 02, 2010 at 12:54:53AM +0200, Adam Hamsik wrote:
> > 
> > In the long term VOP_xxxLOCK() should become part of the file systems.
> AFAIK there is a consensus between yamt@, ad@ and thorpej@ that
> locking should be moved down to the filesystems.
> There was some discussion about it here some time before.

There is a lurking problem making read/write atomically update the file
offset. I suspect that is currently covered by the vnode lock.
Might only affect O_APPEND - but I've seen systems get that wrong!

Not to mention the problem of correctly setting the file position
when read/write fault on a userspace address part way through a


David Laight:

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