Improve workaround for do_image_wic race condition

[AGL/meta-agl.git] / meta-agl-core / classes / image_types_wic_workaround.bbclass

diff --git a/meta-agl-core/classes/image_types_wic_workaround.bbclass b/meta-agl-core/classes/image_types_wic_workaround.bbclass
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+++ b/meta-agl-core/classes/image_types_wic_workaround.bbclass
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+# This is a workaround for the race condition between do_image_wic and other
+# do_image_* tasks. It ensures that no other do_image_* task can be running and
+# reading the rootfs directory at the same time as do_image_wic is modifying
+# the /etc/fstab file in the rootfs directory.
+#
+# A much better fix has been submitted upstream [1], but we can't carry those
+# modifications to `scripts/lib/wic` from poky easily in meta-agl. So instead
+# we have this workaround until the upstream fix is accepted and backported.
+#
+# Serializing the image functions as done here impacts build speed but it's
+# better to be slow and correct than to be fast and wrong.
+#
+# [1]: https://lists.openembedded.org/g/openembedded-core/topic/patch_5_6_wic_copy_rootfs/79592787,
+#      https://lists.openembedded.org/g/openembedded-core/topic/patch_6_6_wic_optimise/79592788
+#      and related patches.
+#
+# Bug-AGL: SPEC-3621
+
+def get_workaround_wic_typedeps(d):
+    if d.getVar('USING_WIC'):
+        fstypes = d.getVar('IMAGE_FSTYPES').split()
+        basetypes = set()
+        for fs in fstypes:
+            # Add the basetype to our set of basetypes in use
+            t = fs.split('.')[0]
+            if t != "wic":
+                basetypes.add(t)
+        return ' '.join(basetypes)
+    else:
+        return ''
+
+IMAGE_TYPEDEP_wic += "${@get_workaround_wic_typedeps(d)}"