[Patch v2] lib/oe: copyhardlinktree - detect mount points

[Jason Plum <jplum@devonit.com>]

    lib/oe: copyhardlinktree - detect mount points
    Add function getmount to detect the mount point of the path, as
    os.stat(path).st_dev in copyhardlinktree fails in lxc containers
    to detect different paths as separate mounted filesystems
    (cp -l failure)

    Signed-off-by: Jason Plum <jplum@devonit.com>

diff --git a/meta/lib/oe/path.py b/meta/lib/oe/path.py
index 1310e38..f1905c3 100644
--- a/meta/lib/oe/path.py
+++ b/meta/lib/oe/path.py
@@ -90,7 +90,7 @@ def copyhardlinktree(src, dst):
     if os.path.isdir(src) and not len(os.listdir(src)):
         return

-    if (os.stat(src).st_dev ==  os.stat(dst).st_dev):
+    if (getmount(src) ==  getmount(dst)):
         # Need to copy directories only with tar first since cp will error if tw
         # writers try and create a directory at the same time
         cmd = 'cd %s; find . -type d -print | tar -cf - -C %s -p --files-from -
@@ -259,3 +259,12 @@ def realpath(file, root, use_physdir = True, loop_cnt = 100,
         raise

     return file
+
+def getmount(path):
+    """ Returns the mount point of the path, using realpath """
+    path = realpath(path)
+    while path != os.path.sep:
+        if os.path.ismount(path):
+            return path
+        path = os.path.abspath(os.path.join(path, os.pardir))
+    return path