[Top] [All Lists]

Re: [PATCH 1/5] fallocate() implementation in i86, x86_64 and powerpc

To: "Amit K. Arora" <aarora@xxxxxxxxxxxxxxxxxx>
Subject: Re: [PATCH 1/5] fallocate() implementation in i86, x86_64 and powerpc
From: Mingming Cao <cmm@xxxxxxxxxx>
Date: Wed, 09 May 2007 10:07:25 -0700
Cc: torvalds@xxxxxxxx, akpm@xxxxxxxxxxxxxxxxxxxx, linux-fsdevel@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, linux-ext4@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx, suparna@xxxxxxxxxx
In-reply-to: <20070509160102.GA30745@xxxxxxxxxxxxxxxxxxxx>
Organization: IBM LTC
References: <20070329115126.GB7374@xxxxxxxxxxxxxxxxxxxx> <20070329101010.7a2b8783.akpm@xxxxxxxxxxxxxxxxxxxx> <20070330071417.GI355@xxxxxxxxxxxxxxxxxxxxxxxx> <20070417125514.GA7574@xxxxxxxxxxxxxxxxxxxx> <20070418130600.GW5967@xxxxxxxxxxxxxxxxxxxx> <20070420135146.GA21352@xxxxxxxxxxxxxxxxxxxx> <20070420145918.GY355@xxxxxxxxxxxxxxxxxxxxxxxx> <20070424121632.GA10136@xxxxxxxxxxxxxxxxxxxx> <20070426175056.GA25321@xxxxxxxxxxxxxxxxxxxx> <20070426180332.GA7209@xxxxxxxxxxxxxxxxxxxx> <20070509160102.GA30745@xxxxxxxxxxxxxxxxxxxx>
Reply-to: cmm@xxxxxxxxxx
Sender: xfs-bounce@xxxxxxxxxxx
On Wed, 2007-05-09 at 21:31 +0530, Amit K. Arora wrote:
> I have the updated patches ready which take care of Andrew's comments.
> Will run some tests and post them soon.
> But, before submitting these patches, I think it will be better to finalize
> on certain things which might be worth some discussion here:
> 1) Should the file size change when preallocation is done beyond EOF ?
>    - Andreas and Chris Wedgwood are in favor of not changing the
>      file size in this case. I also tend to agree with them. Does anyone
>      has an argument in favor of changing the filesize ?
>      If not, I will remove the code which changes the filesize, before I
>      resubmit the concerned ext4 patch.

If we chose not to update the file size beyong EOF, then for filesystem
without fallocate() support (ext2,3 currently), posix_fallocate() will
follow the hard way(zero-out) to do preallocation. Then we will get
different behavior on filesystems w/o fallocate() support. It make sense
to be consistent, IMO.

My point of view, preallocation is just a efficient way to allocating
blocks for files without zero-out, other than this, the new behavior
should be consistent with the old way: file size update,mtime/ctime,


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