On Wed, Mar 24, 2021 at 11:17:59AM -0700, Darrick J. Wong wrote: > On Wed, Mar 24, 2021 at 03:21:16PM +0100, Christoph Hellwig wrote: > > The legacy DMAPI fields were never set by upstream Linux XFS, and have no > > way to be read using the kernel APIs. So instead of bloating the in-core > > inode for them just copy them from the on-disk inode into the log when > > logging the inode. The only caveat is that we need to make sure to zero > > the fields for newly read or deleted inodes, which is solved using a new > > flag in the inode. > > How long ago /did/ non-upstream XFS have DMAPI support? Does it still > have it now? What's the cost of zeroing the fields? > > (Really what I'm saying is that I have so little clue of what dmevmask > and dmstate do that I don't really know what Magic Smoke comes out if > these fields get zeroed by an upstream kernel.) SuSE is shipping SGI patches for it in SLES12, their second newest release. Which is still supported AFAIK.
