On 12/13/23 04:03, Jaegeuk Kim wrote: > On 12/12, Christoph Hellwig wrote: >> On Tue, Dec 12, 2023 at 10:19:31AM -0800, Bart Van Assche wrote: >>> "Fundamentally broken model" is your personal opinion. I don't know anyone >>> else than you who considers zoned writes as a broken model. >> >> No Bart, it is not. Talk to Damien, talk to Martin, to Jens. Or just >> look at all the patches you're sending to the list that play a never >> ending hac-a-mole trying to bandaid over reordering that should be >> perfectly fine. You're playing a long term losing game by trying to >> prevent reordering that you can't win. > > As one of users of zoned devices, I disagree this is a broken model, but even > better than the zone append model. When considering the filesystem performance, > it is essential to place the data per file to get better bandwidth. And for > NAND-based storage, filesystem is the right place to deal with the more efficient > garbage collecion based on the known data locations. That's why all the flash > storage vendors adopted it in the JEDEC. Agreed that zone append is nice, but > IMO, it's not practical for production. The work on btrfs is a counter argument to this statement. The initial zone support based on regular writes was going nowhere as trying to maintain ordering was too complex and/or too invasive. Using zone append for the data path solved and simplified many things. I do think that zone append has a narrower use case spectrum for applications relying on the raw block device directly. But for file systems, it definitely is an easier to use writing model for zoned storage. -- Damien Le Moal Western Digital Research
