package.bbclass: Preserve hard links!

Hard links were not being preserved in the move from the install image
-> package copy.  Again they were being discarded in the package ->
packages-split copy as well.

By preserving the hard links we have the potential to save a ton of rootfs
space.

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/meta/classes/package.bbclass b/meta/classes/package.bbclass
index 8f58ad03f1..0698f64515 100644
--- a/meta/classes/package.bbclass
+++ b/meta/classes/package.bbclass
@@ -323,7 +323,8 @@ python perform_packagecopy () {
         # Start by package population by taking a copy of the installed 
         # files to operate on
         os.system('rm -rf %s/*' % (dvar))
-        os.system('cp -pPR %s/* %s/' % (dest, dvar))
+        # Preserve sparse files and hard links
+        os.system('tar -cf - -C %s -ps . | tar -xf - -C %s' % (dest, dvar))
 }
 
 python populate_packages () {
@@ -383,6 +384,7 @@ python populate_packages () {
 
                 filesvar = bb.data.getVar('FILES', localdata, True) or ""
                 files = filesvar.split()
+                file_links = {}
                 for file in files:
                         if os.path.isabs(file):
                                 file = '.' + file
@@ -406,9 +408,23 @@ python populate_packages () {
                                 bb.mkdirhier(os.path.join(root,file))
                                 os.chmod(os.path.join(root,file), os.stat(file).st_mode)
                                 continue
+
                         fpath = os.path.join(root,file)
                         dpath = os.path.dirname(fpath)
                         bb.mkdirhier(dpath)
+
+                        # Check if this is a hardlink to something... if it is
+                        # attempt to preserve the link information, instead of copy.
+                        if not os.path.islink(file):
+                                s = os.stat(file)
+                                if s.st_nlink > 1:
+                                        file_reference = "%d_%d" % (s.st_dev, s.st_ino)
+                                        if file_reference not in file_links:
+                                                # Save the reference for next time...
+                                                file_links[file_reference] = fpath
+                                        else:
+                                                os.link(file_links[file_reference], fpath)
+                                                continue
                         ret = bb.copyfile(file, fpath)
                         if ret is False or ret == 0:
                                 raise bb.build.FuncFailed("File population failed")