Hi everyone, This third patchriver contains for the realtime modernization project. There are five main parts to this effort -- adding a metadata directory tree; sharding the realtime volume into allocation groups to reduce metadata lock contention; adding reverse mapping; adding reflink; and adding the one piece needed to make quotas work on realtime. This brings the robustness of the realtime volume up to par with the data volume. Christoph Hellwig has recently taken an interest in getting this feature merged to better support zoned storage and garbage collection. This river is much smaller than last year's, as we've recently collaborated to get a bunch of the typedef abuses and casting problems corrected. In theory this can also be used to support things like pmem and cxl.mem via multi-volume XFSes where the fs metadata lives on cheap(er) flash storage so that the pmem can be the exclusive backing of file data on the rt volume. --D
