On Tue, Feb 28, 2017 at 08:31:50AM -0800, Darrick J. Wong wrote: > On Tue, Feb 28, 2017 at 04:15:02PM +0800, Eryu Guan wrote: > > On Fri, Feb 24, 2017 at 05:12:57PM -0800, Darrick J. Wong wrote: > > > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > > > > > If we reflink a file with N blocks to another file one block at a time, > > > does the destination file end up with the same number of extents as the > > > source file? In other words, does the filesystem succeed at combining > > > adjacent mappings into a maximal extents? > > > > I'm not sure if this is a standard behavior and applies to btrfs too? > > But btrfs is failing this test now: > > > > +f1 (1) != f2 (32) > > +s1 (1) != s2 (32) > > > > Fix test or btrfs? I'm taking it if btrfs is the one to be fixed :) > > btrfs has that weird behavior where it doesn't merge the adjacent > extents at all (at least not according to FIEMAP) until you remount the > filesystem. After the remount it's fine, but... WTF? :) > > So yes, the test is working as designed. btrfs needs fixing, or I guess > worst case we can _notrun it on btrfs. Thanks for the explanation! I'll take it as it is at this moment then. > > Snark aside, it was intended originally to make sure that XFS is > properly merging the extent records together; then it occurred to me to > rewrite it with fiemap and make it one of the generic reflink tests so > that ocfs2 can get tested too. Ah, that reminds me that I need to do testing with ocfs2 too, and test passed :) Thanks, Eryu -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
