bitbake: parse: Improve/fix cache invalidation via mtime

We have been seeing obscure failures in devtool, particularly on newer
autobuilder workers where it appears the cache is assumed to be valid
when it shouldn't be.

We're using the 'seconds' granulation mtime field which is not really
a good way of telling if a file has changed. We can switch to the "ns"
version which is better however also add in inode number and size as
precautions. We already have all this data and tuples are fast so there
isn't really any cost to do so.

This hopefully fixes [YOCTO #15318].

(Bitbake rev: d9e5d313c79500e3c70ab9c3239b6b2180194f67)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/bitbake/lib/bb/parse/__init__.py b/bitbake/lib/bb/parse/__init__.py
index a4358f1374..7ffdaa6fd7 100644
--- a/bitbake/lib/bb/parse/__init__.py
+++ b/bitbake/lib/bb/parse/__init__.py
@@ -49,20 +49,23 @@ class SkipPackage(SkipRecipe):
 __mtime_cache = {}
 def cached_mtime(f):
     if f not in __mtime_cache:
-        __mtime_cache[f] = os.stat(f)[stat.ST_MTIME]
+        res = os.stat(f)
+        __mtime_cache[f] = (res.st_mtime_ns, res.st_size, res.st_ino)
     return __mtime_cache[f]
 
 def cached_mtime_noerror(f):
     if f not in __mtime_cache:
         try:
-            __mtime_cache[f] = os.stat(f)[stat.ST_MTIME]
+            res = os.stat(f)
+            __mtime_cache[f] = (res.st_mtime_ns, res.st_size, res.st_ino)
         except OSError:
             return 0
     return __mtime_cache[f]
 
 def check_mtime(f, mtime):
     try:
-        current_mtime = os.stat(f)[stat.ST_MTIME]
+        res = os.stat(f)
+        current_mtime = (res.st_mtime_ns, res.st_size, res.st_ino)
         __mtime_cache[f] = current_mtime
     except OSError:
         current_mtime = 0
@@ -70,7 +73,8 @@ def check_mtime(f, mtime):
 
 def update_mtime(f):
     try:
-        __mtime_cache[f] = os.stat(f)[stat.ST_MTIME]
+        res = os.stat(f)
+        __mtime_cache[f] = (res.st_mtime_ns, res.st_size, res.st_ino)
     except OSError:
         if f in __mtime_cache:
             del __mtime_cache[f]