On Thu, Sep 26, 2019 at 08:17:12AM -0400, Colin Walters wrote: > > > On Wed, Sep 25, 2019, at 10:56 AM, Chris Mason wrote: > > > The data is verified while being decompressed, but that's a fairly large > > fuzzing surface (all of zstd, zlib, and lzo). A lot of people will > > correctly argue that we already have that fuzzing surface today, but I'd > > rather not make a really easy way to stuff arbitrary bytes through the > > kernel decompression code until all the projects involved sign off. > > Right. So maybe have this start of as a BTRFS ioctl and require > privileges? I assume that's sufficient for what Omar wants. That was the first version of this series, but Dave requested that I make it generic [1]. > (Are there actually any other popular Linux filesystems that do transparent compression anyways?) A scan over the kernel tree shows that a few other filesystems do compression: - jffs2 - pstore (if you can call that a filesystem) - ubifs - cramfs (read-only) - erofs (read-only) - squashfs (read-only) None of the "mainstream" general-purpose filesystems have support, but that was also the case for reflink/dedupe before XFS added support. 1: https://lore.kernel.org/linux-fsdevel/20190905021012.GL7777@xxxxxxxxxxxxxxxxxxx/
