On Wed, 13 Aug 2003, Stephan Uphoff wrote:

> Wouldn't this be the ideal time to convert the VFS layer to file system
> internal locking ;-) ?

Uhm, why?

> However I think that it is possible even with the current VFS locking
> style to to put the suspend functionality inside a file system (gating
> below the VFS_ level).

I think I prefer the explicit calls. If we stall all locks, then ALL file
system access (not just writes) will stop. Yes, I realize that atime
updating can be a "write", but there are lots of other places where we
will want to still be able to read from a filesystem while we're
snapshotting. Consider taking a snapshot of the file system that contains
the snapshot program, for instance. :-)

From having worked with layered file systems, life is much easier if we do
the locking outside of the VOP calls.

Take care,

Bill