Re: [RFC]swapfso and "ioctl" function for filesystems

[Robert Millan]

On Wed, Sep 03, 2008 at 02:25:51PM +0200, phcoder wrote:
> Robert Millan wrote:
> > On Wed, Sep 03, 2008 at 11:42:44AM +0200, phcoder wrote:
> >> Hello, all.
> >> For some FS sometimes additional functions are needed. It could be some
> >> type of control (e.g. in ZFS manage zpools) or preparation for OS
> >> booting (e.g. in FAT put IO.SYS and MSDOS.SYS at the begining of the
> >> root directory). While theese functions are quite specific to FS
> >> sometimes are important to implement.
> > 
> > What would be the purpose of that?  Please describe a use case.
> > 
> With ZFS or ext3cow: Suppose you made a huge mistake and installed
> unbootable kernel and have no backup in another file. But ZFS/ext3cow
> has its own backup. So ZFS/ext3cow driver may provide a call something like
> static grub_err_t zfs_timeback (int timeref);
> And anounce it like:
> add_funcs={
> {"timeback", zfs_timeback},
> {0, 0}
> };
> Then a module timeback.mod can suply a command like
> timeback <device> <date>
> which uses the function supplied by zfs and ext3cow.

Could this be made more transparent?  For example, with a variable.

Also, I'm worried that this occupies core image size for non-critical
functionality.

-- 
Robert Millan

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