On 25/04/22 06:36PM, Joanne Koong wrote:
> On Sun, Apr 20, 2025 at 6:34 PM John Groves <John@groves.net> wrote:
> >
> > * FUSE_DAX_FMAP flag in INIT request/reply
> >
> > * fuse_conn->famfs_iomap (enable famfs-mapped files) to denote a
> > famfs-enabled connection
> >
> > Signed-off-by: John Groves <john@groves.net>
> > ---
> > fs/fuse/fuse_i.h | 3 +++
> > fs/fuse/inode.c | 5 +++++
> > include/uapi/linux/fuse.h | 2 ++
> > 3 files changed, 10 insertions(+)
> >
> > diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> > index e04d160fa995..b2c563b1a1c8 100644
> > --- a/fs/fuse/fuse_i.h
> > +++ b/fs/fuse/fuse_i.h
> > @@ -870,6 +870,9 @@ struct fuse_conn {
> > /* Use io_uring for communication */
> > unsigned int io_uring;
> >
> > + /* dev_dax_iomap support for famfs */
> > + unsigned int famfs_iomap:1;
> > +
> > /** Maximum stack depth for passthrough backing files */
> > int max_stack_depth;
> >
> > diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
> > index 29147657a99f..5c6947b12503 100644
> > --- a/fs/fuse/inode.c
> > +++ b/fs/fuse/inode.c
> > @@ -1392,6 +1392,9 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
> > }
> > if (flags & FUSE_OVER_IO_URING && fuse_uring_enabled())
> > fc->io_uring = 1;
> > + if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) &&
> > + flags & FUSE_DAX_FMAP)
> > + fc->famfs_iomap = 1;
> > } else {
> > ra_pages = fc->max_read / PAGE_SIZE;
> > fc->no_lock = 1;
> > @@ -1450,6 +1453,8 @@ void fuse_send_init(struct fuse_mount *fm)
> > flags |= FUSE_SUBMOUNTS;
> > if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH))
> > flags |= FUSE_PASSTHROUGH;
> > + if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX))
> > + flags |= FUSE_DAX_FMAP;
> >
> > /*
> > * This is just an information flag for fuse server. No need to check
> > diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
> > index 5e0eb41d967e..f9e14180367a 100644
> > --- a/include/uapi/linux/fuse.h
> > +++ b/include/uapi/linux/fuse.h
> > @@ -435,6 +435,7 @@ struct fuse_file_lock {
> > * of the request ID indicates resend requests
> > * FUSE_ALLOW_IDMAP: allow creation of idmapped mounts
> > * FUSE_OVER_IO_URING: Indicate that client supports io-uring
> > + * FUSE_DAX_FMAP: kernel supports dev_dax_iomap (aka famfs) fmaps
> > */
> > #define FUSE_ASYNC_READ (1 << 0)
> > #define FUSE_POSIX_LOCKS (1 << 1)
> > @@ -482,6 +483,7 @@ struct fuse_file_lock {
> > #define FUSE_DIRECT_IO_RELAX FUSE_DIRECT_IO_ALLOW_MMAP
> > #define FUSE_ALLOW_IDMAP (1ULL << 40)
> > #define FUSE_OVER_IO_URING (1ULL << 41)
> > +#define FUSE_DAX_FMAP (1ULL << 42)
>
> There's also a protocol changelog at the top of this file that tracks
> any updates made to the uapi. We should probably also update that to
> include this?
Another good catch, thanks Joanne! Adding that in -next
John