[PATCH] Only retry mapping pages when ENOENT is returned

[Adin Scannell <adin@scannell.ca>]

# HG changeset patch
# User Adin Scannell <adin@scannell.ca>
# Date 1324094033 18000
# Node ID 14d42c7d8e0817040186cd01c46f034999fc5dff
# Parent  9dcc8557a0cb676b84e6788e03ab596bcfda7143
Only retry mapping pages when ENOENT is returned

If the return value from the ioctl() is not ENOENT, it's possible that err[i]
will not be updated and libxc will just loop forever.  Although it's unlikely
that err[i] would not be updated after the ioctl() gets through at least once,
it's better to be defensive.

diff -r 9dcc8557a0cb -r 14d42c7d8e08 tools/libxc/xc_linux_osdep.c
--- a/tools/libxc/xc_linux_osdep.c
+++ b/tools/libxc/xc_linux_osdep.c
@@ -232,7 +232,7 @@ static void *linux_privcmd_map_foreign_b
             do {
                 usleep(100);
                 rc = ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH_V2, &ioctlx);
-            } while ( rc < 0 && err[i] == -ENOENT );
+            } while ( rc < 0 && errno == ENOENT && err[i] == -ENOENT );
         }
     }