[OE-core] [PATCH] wic: Fix (again) partition files UIDs on multi rootfs images

[Ricardo Ribalda Delgado]

Commit 450335ba5e73a375eb9932b4c4cf37979640dbfc copies the pseudo
database to the working directory in order to have ownership information
when the filesystem is generated.

Unfortunately this does not work anymore. The filenames on the database
are absolute and there is no information about the new directory.

Instead of fixing the database, we could redo a bit the way we patch the
fstab file. Now I am saving the old contents of fstab, modifying the
file and then reverting the changes on exit.

This is faster than the previous approach, although it can cause
indeterminism if the application is killed before finishing.

Signed-off-by: Ricardo Ribalda Delgado <ricardo at ribalda.com>
---
 scripts/lib/wic/plugins/imager/direct.py | 37 ++++++++----------------
 1 file changed, 12 insertions(+), 25 deletions(-)

diff --git a/scripts/lib/wic/plugins/imager/direct.py b/scripts/lib/wic/plugins/imager/direct.py
index 67addeff3e..91fc5e70f6 100644
--- a/scripts/lib/wic/plugins/imager/direct.py
+++ b/scripts/lib/wic/plugins/imager/direct.py
@@ -49,7 +49,6 @@ class DirectPlugin(ImagerPlugin):
 
         # parse possible 'rootfs=name' items
         self.rootfs_dir = dict(rdir.split('=') for rdir in rootfs_dir.split(' '))
-        self.replaced_rootfs_paths = {}
         self.bootimg_dir = bootimg_dir
         self.kernel_dir = kernel_dir
         self.native_sysroot = native_sysroot
@@ -59,6 +58,7 @@ class DirectPlugin(ImagerPlugin):
         self.compressor = options.compressor
         self.bmap = options.bmap
         self.no_fstab_update = options.no_fstab_update
+        self.original_fstab = None
 
         self.name = "%s-%s" % (os.path.splitext(os.path.basename(wks_file))[0],
                                strftime("%Y%m%d%H%M"))
@@ -104,24 +104,13 @@ class DirectPlugin(ImagerPlugin):
 
         with open(fstab_path) as fstab:
             fstab_lines = fstab.readlines()
+            self.original_fstab = fstab_lines.copy()
 
         if self._update_fstab(fstab_lines, self.parts):
-            # copy rootfs dir to workdir to update fstab
-            # as rootfs can be used by other tasks and can't be modified
-            new_pseudo = os.path.realpath(os.path.join(self.workdir, "pseudo"))
-            from_dir = os.path.join(os.path.join(image_rootfs, ".."), "pseudo")
-            from_dir = os.path.realpath(from_dir)
-            copyhardlinktree(from_dir, new_pseudo)
-            new_rootfs = os.path.realpath(os.path.join(self.workdir, "rootfs_copy"))
-            copyhardlinktree(image_rootfs, new_rootfs)
-            fstab_path = os.path.join(new_rootfs, 'etc/fstab')
-
-            os.unlink(fstab_path)
-
             with open(fstab_path, "w") as fstab:
                 fstab.writelines(fstab_lines)
-
-            return new_rootfs
+        else:
+            self.original_fstab = None
 
     def _update_fstab(self, fstab_lines, parts):
         """Assume partition order same as in wks"""
@@ -170,14 +159,8 @@ class DirectPlugin(ImagerPlugin):
         filesystems from the artifacts directly and combine them into
         a partitioned image.
         """
-        if self.no_fstab_update:
-            new_rootfs = None
-        else:
-            new_rootfs = self._write_fstab(self.rootfs_dir.get("ROOTFS_DIR"))
-        if new_rootfs:
-            # rootfs was copied to update fstab
-            self.replaced_rootfs_paths[new_rootfs] = self.rootfs_dir['ROOTFS_DIR']
-            self.rootfs_dir['ROOTFS_DIR'] = new_rootfs
+        if not self.no_fstab_update:
+            self._write_fstab(self.rootfs_dir.get("ROOTFS_DIR"))
 
         for part in self.parts:
             # get rootfs size from bitbake variable if it's not set in .ks file
@@ -253,8 +236,6 @@ class DirectPlugin(ImagerPlugin):
             else:
                 suffix = '["%s"]:' % (part.mountpoint or part.label)
             rootdir = part.rootfs_dir
-            if rootdir in self.replaced_rootfs_paths:
-                rootdir = self.replaced_rootfs_paths[rootdir]
             msg += '  ROOTFS_DIR%s%s\n' % (suffix.ljust(20), rootdir)
 
         msg += '  BOOTIMG_DIR:                  %s\n' % self.bootimg_dir
@@ -292,6 +273,12 @@ class DirectPlugin(ImagerPlugin):
             if os.path.isfile(path):
                 shutil.move(path, os.path.join(self.outdir, fname))
 
+        #Restore original fstab
+        if self.original_fstab:
+            fstab_path = self.rootfs_dir.get("ROOTFS_DIR") + "/etc/fstab"
+            with open(fstab_path, "w") as fstab:
+                fstab.writelines(self.original_fstab)
+
         # remove work directory
         shutil.rmtree(self.workdir, ignore_errors=True)
 
-- 
2.20.1