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 <alex.zeffertt@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 1 insertions, 2 deletions

diff --git a/include/linux/magic.h b/include/linux/magic.h
index f7f3fdddbef0..439f6f3cb0c4 100644
--- a/include/linux/magic.h
+++ b/include/linux/magic.h
@@ -13,6 +13,7 @@
 #define EFS_SUPER_MAGIC         0x414A53
 #define EXT2_SUPER_MAGIC        0xEF53
 #define EXT3_SUPER_MAGIC        0xEF53
+#define XENFS_SUPER_MAGIC       0xabba1974
 #define EXT4_SUPER_MAGIC        0xEF53
 #define HPFS_SUPER_MAGIC        0xf995e849
 #define ISOFS_SUPER_MAGIC       0x9660
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 6369d89c25d5..f87f9614844d 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -136,8 +136,6 @@ struct xenbus_transaction
 /* Nil transaction ID. */
 #define XBT_NIL ((struct xenbus_transaction) { 0 })
 
-int __init xenbus_dev_init(void);
-
 char **xenbus_directory(struct xenbus_transaction t,
                         const char *dir, const char *node, unsigned int *num);
 void *xenbus_read(struct xenbus_transaction t,