On Tue, Sep 12, 2023 at 09:54:08PM +0300, Amir Goldstein wrote: > Overlayfs stores its files data in backing files on other filesystems. > > Factor out some common helpers to perform io to backing files, that will > later be reused by fuse passthrough code. > > Suggested-by: Miklos Szeredi <miklos@xxxxxxxxxx> > Link: https://lore.kernel.org/r/CAJfpeguhmZbjP3JLqtUy0AdWaHOkAPWeP827BBWwRFEAUgnUcQ@xxxxxxxxxxxxxx > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > --- > > Miklos, > > This is the re-factoring that you suggested in the FUSE passthrough > patches discussion linked above. > > This patch is based on the overlayfs prep patch set I just posted [1]. > > Although overlayfs currently is the only user of these backing file > helpers, I am sending this patch to a wider audience in case other > filesystem developers want to comment on the abstraction. > > We could perhaps later considering moving backing_file_open() helper > and related code to backing_file.c. > > In any case, if there are no objections, I plan to queue this work > for 6.7 via the overlayfs tree. > > Thanks, > Amir. > > [1] https://lore.kernel.org/linux-unionfs/20230912173653.3317828-1-amir73il@xxxxxxxxx/ > > > MAINTAINERS | 2 + > fs/Kconfig | 4 + > fs/Makefile | 1 + > fs/backing_file.c | 160 +++++++++++++++++++++++++++++++++++ > fs/overlayfs/Kconfig | 1 + > fs/overlayfs/file.c | 137 ++---------------------------- > fs/overlayfs/overlayfs.h | 2 - > fs/overlayfs/super.c | 11 +-- > include/linux/backing_file.h | 22 +++++ > 9 files changed, 199 insertions(+), 141 deletions(-) > create mode 100644 fs/backing_file.c > create mode 100644 include/linux/backing_file.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 90f13281d297..4e1d21773e0e 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -16092,7 +16092,9 @@ L: linux-unionfs@xxxxxxxxxxxxxxx > S: Supported > T: git git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git > F: Documentation/filesystems/overlayfs.rst > +F: fs/backing_file.c > F: fs/overlayfs/ > +F: include/linux/backing_file.h I'd like to do this slightly differently, please. All vfs infra goes through vfs trees but for new infra like this where someone steps up to be a maintainer we add a new section (like bpf or networking does): VFS [BACKING FILE] M: Miklos Szeredi <miklos@xxxxxxxxxx> M: Amir Goldstein <amir73il@xxxxxxxxx> F: fs/backing_file.c F: include/linux/backing_file.h L: linux-fsdevel@xxxxxxxxxxxxxxx S: Maintained
