Alasdair, I am not aware of any "cons" associated with this patch. Mikulas are you? Alasdair would like both "pros" and "cons" documented in the patch header. Here is a revised patch header that now documents why this patch is a prerequisite for snapshot-merge (specifically this patch: http://patchwork.kernel.org/patch/60708/): From: Mikulas Patocka <mpatocka@xxxxxxxxxx> The previous code selected one exception as "primary_pe", linked all other exceptions on it and used reference counting to wait until all exceptions are reallocated. All the complexity with exceptions linking and reference counting has been removed. Now, a bio is linked to one exception and when that exception is reallocated, the bio is retried to possibly wait for other exceptions. The new __origin_write() interface affords the snapshot-merge support, snapshot_merge_process() specifically, the ability to trigger exceptions in other snapshots without having a need for an associated bio (which snapshot-merge does not generate). As such this patch is a prerequisite for snapshot-merge. Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
