xfs
[Top] [All Lists]

Re: [RFC] add FIEMAP ioctl to efficiently map file allocation

To: David Chinner <dgc@xxxxxxx>
Subject: Re: [RFC] add FIEMAP ioctl to efficiently map file allocation
From: Andreas Dilger <adilger@xxxxxxxxxxxxx>
Date: Tue, 1 May 2007 15:32:36 -0700
Cc: Nicholas Miell <nmiell@xxxxxxxxxxx>, linux-ext4@xxxxxxxxxxxxxxx, linux-fsdevel@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx, hch@xxxxxxxxxxxxx
In-reply-to: <20070501142049.GG77450368@xxxxxxxxxxxxxxxxx>
Mail-followup-to: David Chinner <dgc@xxxxxxx>, Nicholas Miell <nmiell@xxxxxxxxxxx>, linux-ext4@xxxxxxxxxxxxxxx, linux-fsdevel@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx, hch@xxxxxxxxxxxxx
References: <20070412110550.GM5967@xxxxxxxxxxxxxxxxxxxx> <20070416112252.GJ48531920@xxxxxxxxxxxxxxxxx> <20070419002139.GK5967@xxxxxxxxxxxxxxxxxxxx> <20070419015426.GM48531920@xxxxxxxxxxxxxxxxx> <20070430224401.GX5967@xxxxxxxxxxxxxxxxxxxx> <20070501042254.GD77450368@xxxxxxxxxxxxxxxxx> <1177994346.3362.5.camel@entropy> <20070501142049.GG77450368@xxxxxxxxxxxxxxxxx>
Sender: xfs-bounce@xxxxxxxxxxx
User-agent: Mutt/1.4.1i
On May 02, 2007  00:20 +1000, David Chinner wrote:
> My point was that there is a difference between specification and
> implementation - if the specification says something is compulsory,
> then they must be implemented in the filesystem. This is easy
> enough to ensure by code review - we don't need additional interface
> complexity for this....

What you seem to be missing about my proposal is that the FLAG_INCOMPAT
is for future use by that part of the specification we haven't thought
of yet...  Having COMPAT/INCOMPAT flags has been very useful for ext2/3/4,
and is much better than having version numbers for the interface.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.


<Prev in Thread] Current Thread [Next in Thread>