Fixed MTP to work with TWRP

fs/ext3/xattr_security.c

@@ -0,0 +1,78 @@
+/*
+ * linux/fs/ext3/xattr_security.c
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include <linux/security.h>
+#include "ext3.h"
+#include "xattr.h"
+
+static size_t
+ext3_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
+			 const char *name, size_t name_len, int type)
+{
+	const size_t prefix_len = XATTR_SECURITY_PREFIX_LEN;
+	const size_t total_len = prefix_len + name_len + 1;
+
+
+	if (list && total_len <= list_size) {
+		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
+		memcpy(list+prefix_len, name, name_len);
+		list[prefix_len + name_len] = '\0';
+	}
+	return total_len;
+}
+
+static int
+ext3_xattr_security_get(struct dentry *dentry, const char *name,
+		void *buffer, size_t size, int type)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return ext3_xattr_get(dentry->d_inode, EXT3_XATTR_INDEX_SECURITY,
+			      name, buffer, size);
+}
+
+static int
+ext3_xattr_security_set(struct dentry *dentry, const char *name,
+		const void *value, size_t size, int flags, int type)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return ext3_xattr_set(dentry->d_inode, EXT3_XATTR_INDEX_SECURITY,
+			      name, value, size, flags);
+}
+
+static int ext3_initxattrs(struct inode *inode,
+			   const struct xattr *xattr_array,
+			   void *fs_info)
+{
+	const struct xattr *xattr;
+	handle_t *handle = fs_info;
+	int err = 0;
+
+	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+		err = ext3_xattr_set_handle(handle, inode,
+					    EXT3_XATTR_INDEX_SECURITY,
+					    xattr->name, xattr->value,
+					    xattr->value_len, 0);
+		if (err < 0)
+			break;
+	}
+	return err;
+}
+
+int
+ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
+		   const struct qstr *qstr)
+{
+	return security_inode_init_security(inode, dir, qstr,
+					    &ext3_initxattrs, handle);
+}
+
+const struct xattr_handler ext3_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.list	= ext3_xattr_security_list,
+	.get	= ext3_xattr_security_get,
+	.set	= ext3_xattr_security_set,
+};