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charset=us-ascii Content-Disposition: inline On Sat, Sep 20, 2025 at 09:11:02AM -0300, Augusto wrote: > Hello. > Thanks for reading that message. > Please excuse if here not was the correct area to contact you. > I use Linux with dm-cache writeback. You are the dm cache developer ? If yes > thanks very much for making it. > I want report an issue using dm-cache writeback with BTRFS. > If the dm-cache writeback is full will happen an partial write of files in > BTRFS file system and doing it create the terrible "Parent Transid Verify > Failed" that in some times is fatal error. > I understand that writeback cache can damage file system if not is done an > full flush to disk, but BTRFS is extremely fragile compared with others file > systems. > I want continue using dm-cache writeback in BTRFS file system. > Perhaps implementing an new feature in dm-cache that when the writeback > cache is full is done an partial flush to disk in reference for some files > in wb cache, but that partial number of files will be totally writen to disk > avoiding partial writen of any file that is the because happen errors in > BTRFS using wb cache. > In others words if the cache is full will be done writen some files to disk > with correct file size not doing partial flush to any file. > In moment I not see any dm cache command setting to avoid that issue. > Have an nice next week and excuse me if here not was the correct way to > contact you about it. > Please be specific about which DM targets you're using. Please run and share output from: lsblk mount dmsetup table But once you have that info, you'd do well to post any further questions you might have to dm-devel@lists.linux.dev (now cc'd). Thanks, Mike