Just like cifs and nfs, this short series enables rootfs support for 9p. Bellow is an example which mounts v9fs with tag 'r' as rootfs in qemu guest via virtio transport. $ qemu-system-x86_64 -enable-kvm -cpu host -m 1024 \ -virtfs local,path=$rootfs_dir,mount_tag=r,security_model=passthrough,id=r \ -kernel /path/to/linux/arch/x86/boot/bzImage -nographic \ -append "root=/dev/v9fs v9fsroot=r,trans=virtio rw console=ttyS0 3" v3: o rebase. v2: o use pr_err instead of printk. o ROOT_DEV is only set after checking. o cleanup DEFAULT_MNT_OPTS. o do not retry mount for fd and virtio transport. Changbin Du (3): 9p: add support for root file systems 9p: doc: move to a new dedicated folder 9p: doc: add v9fsroot description Changbin Du (3): 9p: add support for root file systems 9p: doc: move to a new dedicated folder 9p: doc: add v9fsroot description Documentation/filesystems/index.rst | 2 +- Documentation/filesystems/{ => v9fs}/9p.rst | 0 Documentation/filesystems/v9fs/index.rst | 12 ++++ Documentation/filesystems/v9fs/v9fsroot.rst | 52 +++++++++++++++++ MAINTAINERS | 8 ++- fs/9p/Kconfig | 6 ++ fs/9p/Makefile | 1 + fs/9p/v9fsroot.c | 64 +++++++++++++++++++++ include/linux/root_dev.h | 1 + init/do_mounts.c | 55 ++++++++++++++++++ 10 files changed, 199 insertions(+), 2 deletions(-) rename Documentation/filesystems/{ => v9fs}/9p.rst (100%) create mode 100644 Documentation/filesystems/v9fs/index.rst create mode 100644 Documentation/filesystems/v9fs/v9fsroot.rst create mode 100644 fs/9p/v9fsroot.c -- 2.30.2