Re: Ext2/3 block remapping tool

[Andreas Dilger <adilger@clusterfs.com>]

On May 01, 2007  11:28 -0400, Theodore Tso wrote:
> On Tue, May 01, 2007 at 12:01:42AM -0600, Andreas Dilger wrote:
> > Except one other issue with online shrinking is that we need to move
> > inodes on occasion and this poses a bunch of other problems over just
> > remapping the data blocks.
> 
> Well, I did say "necessary", and not "sufficient".  But yes, moving
> inodes, especially if the inode is currently open gets interesting.  I
> don't think there are that many user space applications that would
> notice or care if the st_ino of an open file changed out from under
> them, but there are obviously userspace applications, such as tar,
> that would most definitely care.

I think "rm -r" does a LOT of this kind of operation, like:

stat(.); stat(foo); chdir(foo); stat(.); unlink(*); chdir(..); stat(.)

I think "find" does the same to avoid security problems with malicious
path manipulation.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.