X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=daemon%2Fdaemon.h;h=70f0beef9decbd640c8514dee05b0d2540e5a69f;hb=826020fe18bf2eee43f8afea392874bb88c0650a;hp=c3b9120932eaee6b23bffc8c988afe68f77f90cd;hpb=875dc84cc01dacb1e254e294a66e179b96fbdbc6;p=libguestfs.git

diff --git a/daemon/daemon.h b/daemon/daemon.h
index c3b9120..70f0bee 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -139,7 +139,13 @@ extern void reply (xdrproc_t xdrp, char *ret);
 
 /* Helper for functions which need either an absolute path in the
  * mounted filesystem, OR a /dev/ device which exists.
+ *
  * NB. Cannot be used for FileIn functions.
+ *
+ * NB #2: Functions which mix filenames and device paths should be
+ * avoided, and existing functions should be deprecated.  This is
+ * because we intend in future to make device parameters a distinct
+ * type from filenames.
  */
 #define NEED_ROOT_OR_IS_DEVICE(path,errcode) \
   do {									\
@@ -156,11 +162,22 @@ extern void reply (xdrproc_t xdrp, char *ret);
  * (2) You must not change directory!  cwd must always be "/", otherwise
  *     we can't escape our own chroot.
  * (3) All paths specified must be absolute.
- * (4) CHROOT_OUT does not affect errno.
+ * (4) Neither macro affects errno.
  */
-#define CHROOT_IN chroot ("/sysroot");
-#define CHROOT_OUT \
-  do { int old_errno = errno; chroot ("."); errno = old_errno; } while (0)
+#define CHROOT_IN				\
+  do {						\
+    int __old_errno = errno;			\
+    if (chroot ("/sysroot") == -1)		\
+      perror ("CHROOT_IN: sysroot");		\
+    errno = __old_errno;			\
+  } while (0)
+#define CHROOT_OUT				\
+  do {						\
+    int __old_errno = errno;			\
+    if (chroot (".") == -1)			\
+      perror ("CHROOT_OUT: .");			\
+    errno = __old_errno;			\
+  } while (0)
 
 /* Marks functions which are not implemented.
  * NB. Cannot be used for FileIn functions.