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From: Eric Sandeen <sandeen@redhat.com>
To: Subranshu Patel <spatel.ml@gmail.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: Block allocation in EXT4
Date: Mon, 26 Aug 2013 12:54:31 -0500	[thread overview]
Message-ID: <521B9657.1050308@redhat.com> (raw)
In-Reply-To: <CAEUQceiEUQOHf8ujjbJF2Q3HSvcqo7r=KOfgoCkFGB_tE6EdcA@mail.gmail.com>

On 8/26/13 10:55 AM, Subranshu Patel wrote:
>  In EXT4 it seems that both direct/indirect and extent tree based
> block allocation is used. I used debugfs and it seems that the root
> inode uses the direct/indirect block allocation. The other files and
> direcyories used extent based allocation.
> 
> Do all the EXT4 reserved inode (0 -11) use the direct/indirect
> allocation scheme?

Nope; looks like a leftover oddity from old mkfs.

mkfs-time created dirs weren't created w/ the extents flag until:

commit 1afb468b9a80031b39eab37272709f45727fb221
Author: Theodore Ts'o <tytso@mit.edu>
Date:   Fri Jun 10 13:58:18 2011 -0400

    libext2fs: create extent-based directories if the extents feature is enabled
    
    This allows mke2fs to create the root and lost+found directories using
    extents.
    
    Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

so newly mkfs'd filesystems w/ newer e2fsprogs shouldn't exhibit
what you see.

-Eric


      parent reply	other threads:[~2013-08-26 17:54 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-26 15:55 Block allocation in EXT4 Subranshu Patel
2013-08-26 17:45 ` Felipe Monteiro de Carvalho
2013-08-26 17:54 ` Eric Sandeen [this message]

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