[openembedded-core] [scarthgap] [PATCH v1 34/34] cve-update: Avoid NFS caching issues

["Het Patel -X (hetpat - E INFOCHIPS PRIVATE LIMITED at Cisco)" <hetpat@cisco.com>]

From: Paul Barker <paul@pbarker.dev>

When moving the updated CVE database file to the downloads directory,
ensure that it has a different inode number to the previous version of
this file.

We have seen "sqlite3.DatabaseError: database disk image is malformed"
exceptions on our autobuilder when trying to read the CVE database in
do_cve_check tasks. The context here is that the downloads directory
(where the updated database file is copied to) is shared between workers
as an NFS mount. Different autobuilder workers were seeing different
checksums for the database file, which indicates that a mix of both new
and stale data was being read. Forcing each new version of the database
file to have a different inode number will prevent stale data from being
read from local caches.

This should fix [YOCTO #16086].

Signed-off-by: Paul Barker <paul@pbarker.dev>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit f63622bbec1cfaca6d0b3e05e11466e4c10fa86e)
Signed-off-by: Het Patel <hetpat@cisco.com>
---
 meta/recipes-core/meta/cve-update-db-native.bb   | 9 +++++++--
 meta/recipes-core/meta/cve-update-nvd2-native.bb | 9 +++++++--
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/meta/recipes-core/meta/cve-update-db-native.bb b/meta/recipes-core/meta/cve-update-db-native.bb
index 6edf705704..b0272cdddd 100644
--- a/meta/recipes-core/meta/cve-update-db-native.bb
+++ b/meta/recipes-core/meta/cve-update-db-native.bb
@@ -78,8 +78,13 @@ python do_fetch() {
         shutil.copy2(db_file, db_tmp_file)
 
     if update_db_file(db_tmp_file, d):
-        # Update downloaded correctly, can swap files
-        shutil.move(db_tmp_file, db_file)
+        # Update downloaded correctly, we can swap files. To avoid potential
+        # NFS caching issues, ensure that the destination file has a new inode
+        # number. We do this in two steps as the downloads directory may be on
+        # a different filesystem to tmpdir we're working in.
+        new_file = "%s.new" % (db_file)
+        shutil.move(db_tmp_file, new_file)
+        os.rename(new_file, db_file)
     else:
         # Update failed, do not modify the database
         bb.warn("CVE database update failed")
diff --git a/meta/recipes-core/meta/cve-update-nvd2-native.bb b/meta/recipes-core/meta/cve-update-nvd2-native.bb
index abcbcffcc6..8c8148dd92 100644
--- a/meta/recipes-core/meta/cve-update-nvd2-native.bb
+++ b/meta/recipes-core/meta/cve-update-nvd2-native.bb
@@ -93,8 +93,13 @@ python do_fetch() {
         shutil.copy2(db_file, db_tmp_file)
 
     if update_db_file(db_tmp_file, d, database_time):
-        # Update downloaded correctly, can swap files
-        shutil.move(db_tmp_file, db_file)
+        # Update downloaded correctly, we can swap files. To avoid potential
+        # NFS caching issues, ensure that the destination file has a new inode
+        # number. We do this in two steps as the downloads directory may be on
+        # a different filesystem to tmpdir we're working in.
+        new_file = "%s.new" % (db_file)
+        shutil.move(db_tmp_file, new_file)
+        os.rename(new_file, db_file)
     else:
         # Update failed, do not modify the database
         bb.warn("CVE database update failed")