On Thu, 2006-11-09 at 07:46 -0500, Jeff Garzik wrote:

sho@tnes.nec.co.jp wrote:

quoted

I have written the patches of ioctl for extent base online defragment
and the command which call it.
These patches are at the experimental stage so they need many
improvements.  But they work well so far as basic defragmenter,
which means they are worth enough to examine my trial.

- Specify the target area in a file using the following structure:
  struct ext3_ext_defrag_data {
	  loff_t start_offset; /* start offset to defrag in bytes */
	  loff_t defrag_size;  /* size of defrag in bytes */
  }
  It uses loff_t so that the size of the structure is identical on
  both 32 bits and 64 bits architecture.
  Block allocation, including searching for the free contiguous
  blocks, is implemented in kernel.

NAK the ioctl approach.

I agree it shouldn't go into mainline this way, but while the details of
the proper interface are debated, this implementation at least allows
the core function to be tested & reviewed.

People who like ioctls are just holdovers from non-Linux OS's.

	Jeff

Shaggy
-- 
David Kleikamp
IBM Linux Technology Center