On Mon, Jul 25, 2011 at 4:44 PM, Christoph Hellwig [off-list ref] wrote:

On Mon, Jul 25, 2011 at 09:02:25PM +0800, Wang Sheng-Hui wrote:

quoted

The patch is against 3.0

In the definition of struct journal_head, the comment for
the field "unsigned b_cow_tid" says the field tracks the
last transaction id in which this buffer has been cowed.

The correct fix is to simply remove the field, as it's entirely unused.

It's part of the ext4 snapshot patches, which are making their way into mainline
as slowly as one could expect them to.
This patch was merged for 2.6.39, so more users will be able to test
ext4 snapshots
independent module without having to patch their kernels, so that the
patches get proper
QA before they arrive to mainline.

Cheers,
Amir.