Re: [GSoC 2013] Implement file system flags to scrub data blocks before deletion

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Fri, May 17, 2013 at 12:28:54AM -0500, Eric Haszlakiewicz wrote:
> 
>   Will the code that does the wiping be a part of the kernel, or
>   are you thinking to hand that off to a userland process?  (perhaps
>   similar to lfs_cleanerd)

This strikes me as a bad idea.  One of the major problems with our LFS
implementation is that it's almost impossible to keep the kernel and the
cleaner in sync while avoiding deadlock.

Another, of course, is the difficulty of maintaining our security model
while allowing the cleaner to access raw blocks, even with the bmap/mark
interface the cleaner uses.  It seems to me the kernel would have to do
the cleaning -- which would be easier today than it was for the LFS
code because we have better ways to defer activity in the kernel.

Thor