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?
Hello,
I'm no expert, but I think that you should read i_node.i_flags and
check it for the flag EXT4_EXTENTS_FL to determine which inodes use
the old or the new (extents) method of allocation.
I'm not sure what your objective is, so hopefully this helps something =)
--
Felipe Monteiro de Carvalho
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 <[email protected]>
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" <[email protected]>
so newly mkfs'd filesystems w/ newer e2fsprogs shouldn't exhibit
what you see.
-Eric