2006-10-06 04:58:14

by Randy Dunlap

[permalink] [raw]
Subject: Re: + ext4-enable.patch added to -mm tree

On Thu, 05 Oct 2006 17:36:11 -0700 [email protected] wrote:

> Subject: ext4: enable building of ext4
> From: Mingming Cao<[email protected]>
>
> Originally part of a patch from Mingming Cao and Randy Dunlap. Reorganized
> by Shaggy.
> ---
>
> fs/Kconfig | 75 +++++++++++++++++++++++++++++++++++++---
> fs/Makefile | 1
> include/linux/magic.h | 1
> 3 files changed, 73 insertions(+), 4 deletions(-)
>
> diff -puN fs/Kconfig~ext4-enable fs/Kconfig
> --- a/fs/Kconfig~ext4-enable
> +++ a/fs/Kconfig
> @@ -140,6 +140,73 @@ config EXT3_FS_SECURITY
> If you are not using a security module that requires using
> extended attributes for file security labels, say N.
>
> +config EXT4DEV_FS
> + tristate "Ext4dev/ext4 extended fs support development (EXPERIMENTAL)"
> + depends on EXPERIMENTAL
> + select JBD
> + help

ugh, I'm getting seasick from looking at that indentation.
I don't have an ext4 patchset ATM, but I'll fix that if no one
else does.

> + Ext4dev is a predecessor filesystem of the next generation
> + extended fs ext4, based on ext3 filesystem code. It will be
> + renamed ext4 fs later, once ext4dev is mature and stabilized.
> +
> + Unlike the change from ext2 filesystem to ext3 filesystem,
> + the on-disk format of ext4dev is not the same as ext3 any more:
> + it is based on extent maps and it supports 48-bit physical block
> + numbers. These combined on-disk format changes will allow
> + ext4dev/ext4 to handle more than 16 TB filesystem volumes --
> + a hard limit that ext3 cannot overcome without changing the
> + on-disk format.
> +
> + Other than extent maps and 48-bit block numbers, ext4dev also is
> + likely to have other new features such as persistent preallocation,
> + high resolution time stamps, and larger file support etc. These
> + features will be added to ext4dev gradually.
> +
> + To compile this file system support as a module, choose M here. The
> + module will be called ext4dev. Be aware, however, that the filesystem
> + of your root partition (the one containing the directory /) cannot
> + be compiled as a module, and so this could be dangerous.
> +
> + If unsure, say N.

---
~Randy


2006-10-06 05:07:52

by Andrew Morton

[permalink] [raw]
Subject: Re: + ext4-enable.patch added to -mm tree

On Thu, 5 Oct 2006 21:59:41 -0700
Randy Dunlap <[email protected]> wrote:

> > +config EXT4DEV_FS
> > + tristate "Ext4dev/ext4 extended fs support development (EXPERIMENTAL)"
> > + depends on EXPERIMENTAL
> > + select JBD
> > + help
>
> ugh, I'm getting seasick from looking at that indentation.
> I don't have an ext4 patchset ATM, but I'll fix that if no one
> else does.

That's someone's broken tab key again. I fixed up my copy of that patch.