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Re: WAPBL patch for testing

On Sat, Nov 08, 2008 at 09:58:09AM +0100, Juergen Hannken-Illjes wrote:
> On Fri, Nov 07, 2008 at 07:45:53PM -0800, Bill Stouder-Studenmund wrote:
> > On Fri, Oct 31, 2008 at 03:10:24PM -0400, Thor Lancelot Simon wrote:
> > > code used the same notion of a "transaction"?  I was very surprised
> > > to see that wapbl brought in an a whole new idea of a "fs transaction"
> > > when the snapshot code already seemed to have one.
> > 
> > I think one issue is that wapbl predates fss. Yes, it only got released 
> > recently, but it is older.
> > 
> > Also, I believe wapbl and fss really do have different ideas about what 
> > their transactions are. wapbl always needs to copy blocks and the snapshot 
> > code only needs to copy blocks if they change for the first time since the 
> > last snapshot. Likewise, wapbl never allocates blocks (it just writes a 
> > copy to the journal) and the snapshot code allocates new blocks in the fs.
> Snapshots don't have transactions.  We have fstrans for file system
> suspension and here it helps to get the file system into a consistent
> and quiet state.

Well, that clearly explins why they have different ideas of a transaction. 

Take care,


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