From 1107ba885e46964316c083d441d5dd185b6c9e49 Mon Sep 17 00:00:00 2001 From: Alex Zeffertt Date: Wed, 7 Jan 2009 18:07:11 -0800 Subject: xen: add xenfs to allow usermode <-> Xen interaction The xenfs filesystem exports various interfaces to usermode. Initially this exports a file to allow usermode to interact with xenbus/xenstore. Traditionally this appeared in /proc/xen. Rather than extending procfs, this patch adds a backward-compat mountpoint on /proc/xen, and provides a xenfs filesystem which can be mounted there. Signed-off-by: Alex Zeffertt Signed-off-by: Jeremy Fitzhardinge Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/xen/xenfs/super.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 drivers/xen/xenfs/super.c (limited to 'drivers/xen/xenfs/super.c') diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c new file mode 100644 index 00000000000..515741a8e6b --- /dev/null +++ b/drivers/xen/xenfs/super.c @@ -0,0 +1,64 @@ +/* + * xenfs.c - a filesystem for passing info between the a domain and + * the hypervisor. + * + * 2008-10-07 Alex Zeffertt Replaced /proc/xen/xenbus with xenfs filesystem + * and /proc/xen compatibility mount point. + * Turned xenfs into a loadable module. + */ + +#include +#include +#include +#include +#include + +#include "xenfs.h" + +#include + +MODULE_DESCRIPTION("Xen filesystem"); +MODULE_LICENSE("GPL"); + +static int xenfs_fill_super(struct super_block *sb, void *data, int silent) +{ + static struct tree_descr xenfs_files[] = { + [2] = {"xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR}, + {""}, + }; + + return simple_fill_super(sb, XENFS_SUPER_MAGIC, xenfs_files); +} + +static int xenfs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, + void *data, struct vfsmount *mnt) +{ + return get_sb_single(fs_type, flags, data, xenfs_fill_super, mnt); +} + +static struct file_system_type xenfs_type = { + .owner = THIS_MODULE, + .name = "xenfs", + .get_sb = xenfs_get_sb, + .kill_sb = kill_litter_super, +}; + +static int __init xenfs_init(void) +{ + if (xen_pv_domain()) + return register_filesystem(&xenfs_type); + + printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n"); + return 0; +} + +static void __exit xenfs_exit(void) +{ + if (xen_pv_domain()) + unregister_filesystem(&xenfs_type); +} + +module_init(xenfs_init); +module_exit(xenfs_exit); + -- cgit v1.2.3-70-g09d2