Support non-extent mapped block based/whole file dedupe
Opened this issue · 2 comments
I've implemented FIDEDUPERANGE for ZFS recently (PR is not accepted yet, but ongoing), however, FIEMAP support is not likely to happen anytime soon.
Right now, all forms of checksumming require the extent map, even whole file dedupe (right now to test zfs dedupe i pipe in the results of fdupes). They simply do different ranges of extends (all of them, some of them, you name it).
It would be nice to support simple block based and whole-file dedupe that did not require extent mapping ioctl to work.
The deduperange ioctl works on offset/sizes anyway.
I'm happy to implement this if folks are willing to consider the patches.
I could simply make a fake extent map, or i could make it use different non-extent based code paths when fiemap fails.
Hello @dberlin
This sounds like an interesting usecase
Thank you for your work on openzfs
I will take the time to review your code, if you want this feature merged as soon as possible!
If not, I will work on that later
Great. I'll send a PR that makes a fake extent map for now, and you can take a look and tell me whether you want me to take a different approach or not :)