Re: [PATCH] xen: add xenfs to allow usermode <-> Xen interaction

[Ingo Molnar <mingo@elte.hu>]

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> [ Reviewers: This is in drivers/xen to keep it close to the code it is 
>   and will be using.  Would people prefer to see it in fs/xenfs? -J ]

> +config XENFS
> +	tristate "Xen filesystem"

there's about two dozen filesystems that live not in fs/*:

./net/socket.c:	register_filesystem(&sock_fs_type);
./net/sunrpc/rpc_pipe.c:	err = register_filesystem(&rpc_pipe_fs_type);
./security/selinux/selinuxfs.c:	err = register_filesystem(&sel_fs_type);
./security/inode.c:	retval = register_filesystem(&fs_type);
./security/smack/smackfs.c:	err = register_filesystem(&smk_fs_type);
./drivers/usb/core/inode.c:	retval = register_filesystem(&usb_fs_type);
./drivers/usb/gadget/inode.c:	status = register_filesystem (&gadgetfs_type);
./drivers/oprofile/oprofilefs.c:	return register_filesystem(&oprofilefs_type);
./drivers/misc/ibmasm/ibmasmfs.c:	return register_filesystem(&ibmasmfs_type);
./drivers/isdn/capi/capifs.c:	err = register_filesystem(&capifs_fs_type);
./drivers/infiniband/hw/ipath/ipath_fs.c:	return register_filesystem(&ipathfs_fs_type);
./drivers/infiniband/core/uverbs_main.c:	ret = register_filesystem(&uverbs_event_fs);
./mm/shmem.c:	error = register_filesystem(&tmpfs_fs_type);
./mm/tiny-shmem.c:	BUG_ON(register_filesystem(&tmpfs_fs_type) != 0);
./ipc/mqueue.c:	error = register_filesystem(&mqueue_fs_type);
./kernel/cpuset.c:	err = register_filesystem(&cpuset_fs_type);
./kernel/cgroup.c:	err = register_filesystem(&cgroup_fs_type);
./include/linux/fs.h:extern int register_filesystem(struct file_system_type *);
./arch/s390/hypfs/inode.c:	rc = register_filesystem(&hypfs_type);
./arch/ia64/kernel/perfmon.c:	int err = register_filesystem(&pfm_fs_type);
./arch/powerpc/platforms/cell/spufs/inode.c:	ret = register_filesystem(&spufs_type);

by the looks of it it wants to live in drivers/xen/. It's a minimalistic 
API-only filesystem.

Nevertheless it would be nice to have Acks from FS experts. Security, 
races, obsoleteness of approach, etc.

	Ingo