Milan, > And the integrity profile is perfect interface for this, we register > own profile through the proper interface. (Any other solution for > per-sector metadata would be worse, I tried...) The DM use case seems a bit weird and I would like to take a closer look later (a storm took out my power and internet so I'm a bit logistically impaired right now). But the intent of the integrity infrastructure was to be able to carry arbitrary metadata pinned to an I/O. The callback hooks in the profile were really only intended for the case where the block layer itself needed to generate and verify. We already do sanity checking on the callback pointers in the prep function. I guess don't have a problem doing the same in the completion path. Fundamentally, though, the verify function should only ever be called if the profile has BLK_INTEGRITY_VERIFY set. Previously that was done in the prep function by only adding the verify endio hook when it was needed. Christoph's patch to kill the double endio changed that subtly (FWIW, Jens originally objected to having an integrity conditional in the regular bio completion path. That's why the verification handling abused the endio function). Anyway. So I think that the BLK_INTEGRITY_VERIFY logic needs to be carried over to __bio_integrity_endio()... -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
