summary refs log tree commit diff
path: root/drivers/xen/xenfs
diff options
context:
space:
mode:
authorJeremy Fitzhardinge <jeremy@goop.org>2009-02-06 18:46:47 -0800
committerJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2009-03-30 09:59:20 -0700
commit818fd20673df82031e604bb784d836f1fc2e2451 (patch)
tree2517bba7961d62b650003fbf7e049f446bd9c3a1 /drivers/xen/xenfs
parent6d02c42698f99eccb290ac53d4f10ca883b9f90c (diff)
downloadlinux-818fd20673df82031e604bb784d836f1fc2e2451.tar.gz
xen: add "capabilities" file
The xenfs capabilities file allows usermode to determine what
capabilities the domain has.  The only one at present is "control_d"
in a privileged domain.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Diffstat (limited to 'drivers/xen/xenfs')
-rw-r--r--drivers/xen/xenfs/super.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index 515741a8e6b8..6559e0c752ce 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -20,10 +20,27 @@
 MODULE_DESCRIPTION("Xen filesystem");
 MODULE_LICENSE("GPL");
 
+static ssize_t capabilities_read(struct file *file, char __user *buf,
+				 size_t size, loff_t *off)
+{
+	char *tmp = "";
+
+	if (xen_initial_domain())
+		tmp = "control_d\n";
+
+	return simple_read_from_buffer(buf, size, off, tmp, strlen(tmp));
+}
+
+static const struct file_operations capabilities_file_ops = {
+	.read = capabilities_read,
+};
+
 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},
+		[1] = {},
+		{ "xenbus", &xenbus_file_ops, S_IRUSR|S_IWUSR },
+		{ "capabilities", &capabilities_file_ops, S_IRUGO },
 		{""},
 	};