Re: [Ext2-devel] [PATCH 1/9] extents for ext4

Mingming Cao
2006-08-14T16:26:38Z

On Sat, 2006-08-12 at 11:20 -0700, Randy.Dunlap wrote:
> On Sat, 12 Aug 2006 10:43:04 -0700 Darrick J. Wong wrote:
>
> > Randy.Dunlap wrote:
> >
> > > Uh, yes. Well, I don't really care for the "ext3dev" name, but
> > > I tried to ignore that "feature" and fix it up anyway.
> > > Feel free to ignore any parts that you don't want.
> >
> > Three nits to pick:
> >
> > > + renamed ext4 fs later, once ext3dev is mature and
> > > stabled.
> >
> > I think you want "stabilized", not "stabled".
> >
> > (Until someone writes horsefs, that is. ;))
> >
> > > + Other than extent maps and 48-bit block number,
> > > ext3dev also is
> >
> > "...48-bit block numbers..."
> >
> > > + By default the debugging output will be turned off.
> >
> > "By default, the..."
>
> Thanks, all fixed, although I think that the comma on the last
> one is optional.

Thanks, Randy and Darrick.

> New patch is below, although what I would
> really prefer to see is this:
>
> - Drop the "ext3dev" name. Use "ext4dev" temporarily, then
> switch to "ext4".
>

I think ext4dev is a better name too. Would you like to make that
changes as well?

Thanks,

Mingming
> ---
> From: Randy Dunlap <rdunlap@xenotime.net>
>
> Clean up help text and module names in ext4 & jbd2 Kconfig entries.
> Add "depends on EXPERIMENTAL".
>
> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
> ---
> fs/Kconfig | 59 ++++++++++++++++++++++++++++++-----------------------------
> 1 files changed, 30 insertions(+), 29 deletions(-)
>
> --- linux-2618-rc4-ext4.orig/fs/Kconfig
> +++ linux-2618-rc4-ext4/fs/Kconfig
> @@ -139,28 +139,29 @@ config EXT3_FS_SECURITY
> extended attributes for file security labels, say N.
>
> config EXT3DEV_FS
> - tristate "Developmenting extended fs support"
> + tristate "Ext3dev/ext4 extended fs support development (EXPERIMENTAL)"
> + depends on EXPERIMENTAL
> select JBD2
> help
> - Ext3dev is a precede filesystem toward next generation
> - of extended fs, based on ext3 filesystem code. It will be
> - renamed ext4 fs later once this ext3dev is mature and stabled.
> + Ext3dev is a predecessor filesystem of the next generation
> + extended fs ext4, based on ext3 filesystem code. It will be
> + renamed ext4 fs later, once ext3dev is mature and stabilized.
>
> Unlike the change from ext2 filesystem to ext3 filesystem,
> the on-disk format of ext3dev is not the same as ext3 any more:
> - it is based on extent maps and it support 48 bit physical block
> + it is based on extent maps and it supports 48-bit physical block
> numbers. These combined on-disk format changes will allow
> - ext3dev/ext4 to handle more than 16TB filesystem volume --
> - a hard limit that ext3 can not overcome without changing
> + ext3dev/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 number, ext3dev also is
> + Other than extent maps and 48-bit block numbers, ext3dev also is
> likely to have other new features such as persistent preallocation,
> - high resolution time stamps and larger file support etc. These
> + high resolution time stamps, and larger file support etc. These
> features will be added to ext3dev gradually.
>
> - To compile this file system support as a module, choose M here: the
> - module will be called ext2. Be aware however that the file system
> + To compile this file system support as a module, choose M here. The
> + module will be called ext3dev. 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.
>
> @@ -177,17 +178,17 @@ config EXT3DEV_FS_XATTR
>
> If unsure, say N.
>
> - You need this for POSIX ACL support on ext3.
> + You need this for POSIX ACL support on ext3dev/ext4.
>
> config EXT3DEV_FS_POSIX_ACL
> bool "Ext3dev POSIX Access Control Lists"
> depends on EXT3DEV_FS_XATTR
> select FS_POSIX_ACL
> help
> - Posix Access Control Lists (ACLs) support permissions for users and
> + POSIX Access Control Lists (ACLs) support permissions for users and
> groups beyond the owner/group/world scheme.
>
> - To learn more about Access Control Lists, visit the Posix ACLs for
> + To learn more about Access Control Lists, visit the POSIX ACLs for
> Linux website <http://acl.bestbits.at/>.
>
> If you don't know what Access Control Lists are, say N
> @@ -199,7 +200,7 @@ config EXT3DEV_FS_SECURITY
> Security labels support alternative access control models
> implemented by security modules like SELinux. This option
> enables an extended attribute handler for file security
> - labels in the ext3 filesystem.
> + labels in the ext3dev/ext4 filesystem.
>
> If you are not using a security module that requires using
> extended attributes for file security labels, say N.
> @@ -240,31 +241,31 @@ config JBD2
> tristate
> help
> This is a generic journaling layer for block devices that support
> - both 32 bit and 64 bit block numbers. It is currently used by
> - the ext3dev/ext4 file system, but it could also be used to add
> + both 32-bit and 64-bit block numbers. It is currently used by
> + the ext3dev/ext4 filesystem, but it could also be used to add
> journal support to other file systems or block devices such
> - as RAID or LVM.
> + as RAID or LVM.
>
> - If you are using the ext4, you need to say Y here. If you are not
> - using ext4 then you will probably want to say N.
> + If you are using ext3dev/ext4, you need to say Y here. If you are not
> + using ext3dev/ext4 then you will probably want to say N.
>
> - To compile this device as a module, choose M here: the module will be
> - called jbd. If you are compiling ext4 into the kernel,
> + To compile this device as a module, choose M here. The module will be
> + called jbd2. If you are compiling ext3dev/ext4 into the kernel,
> you cannot compile this code as a module.
>
> config JBD2_DEBUG
> - bool "JBD2 (ext4) debugging support"
> + bool "JBD2 (ext3dev/ext4) debugging support"
> depends on JBD2
> help
> - If you are using the ext4 journaled file system (or potentially any
> - other file system/device using JBD2), this option allows you to
> - enable debugging output while the system is running, in order to
> - help track down any problems you are having. By default the
> - debugging output will be turned off.
> + If you are using the ext3dev/ext4 journaled file system (or
> + potentially any other filesystem/device using JBD2), this option
> + allows you to enable debugging output while the system is running,
> + in order to help track down any problems you are having.
> + By default, the debugging output will be turned off.
>
> If you select Y here, then you will be able to turn on debugging
> with "echo N > /proc/sys/fs/jbd2-debug", where N is a number between
> - 1 and 5, the higher the number, the more debugging output is
> + 1 and 5. The higher the number, the more debugging output is
> generated. To turn debugging off again, do
> "echo 0 > /proc/sys/fs/jbd2-debug".
>