On Wed, Oct 10, 2018 at 09:12:54PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > A deduplication data corruption is exposed by fstests generic/505 on > XFS. It is caused by extending the block match range to include the > partial EOF block, but then allowing unknown data beyond EOF to be > considered a "match" to data in the destination file because the > comparison is only made to the end of the source file. This corrupts the > destination file when the source extent is shared with it. > > The VFS remapping prep functions only support whole block dedupe, but > we still need to appear to support whole file dedupe correctly. Hence > if the dedupe request includes the last block of the souce file, don't > include it in the actual dedupe operation. If the rest of the range > dedupes successfully, then reject the entire request. A subsequent > patch will enable us to shorten dedupe requests correctly. Ok, so this patch rejects whole file dedupe requests, and then a later patch adds support back in for it? Doesn't that leave a bisect landmine behind? Why separate the functionality like this? Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
