On Thu, Dec 14, 2023 at 01:32:21PM -0800, Darrick J. Wong wrote: > > 1) xfs_rtallocate_extent extents the minlen and reduces the maxlen due > > ^^^^^^^ extends? Yes. I'm definitively talking about extents too much in my life :) > > Move aligning the min and maxlen out of xfs_rtallocate_extent and into > > a helper called directly by xfs_bmap_rtalloc. This allows just > > continuing with the allocation if we have to drop the alignment instead > > of going through the retry loop and also dropping the perfectly the > > minlen adjustment that didn't cause the problem, and then just use > > "...dropping the perfectly *usable* minlen adjustment..." ? > > > a single retry that drops both the minlen and alignment requirement > > when we really are out of space, thus consolidating cases (2) and (3) > > above. > > How can we drop the minlen requirement, won't that result in undersize > mapping allocations? Or is the subtlety here that for realtime files, > that's ok because we never have forced multi-rtx allocations like we do > for the data device? The rtalloc minlen is different from the bmap minlen. The bmap minlen is always 1 except for metadata XFS_BMAPI_CONTIG allocations, which obviosuly can't happen for RT allocations. The rtalloc minlen starts out as a single rtextent and is increases when we adjust the physical allocation location to better align with the previous extent.
