id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
37191	FileBasedCache.touch() raises ValueError: I/O operation on closed file when the key is already expired	Daniel	Ayoub Bouaik	"FileBasedCache.touch() raises ValueError: I/O operation on closed file when called on a key whose timeout has already elapsed (but whose file hasn't been lazily cleaned up yet).

**Steps to reproduce:**

Use the following settings

{{{
CACHES = {
    ""default"": {
        ""BACKEND"": ""django.core.cache.backends.filebased.FileBasedCache"",
        ""LOCATION"": ""/var/tmp/django_cache"",
    },
}
}}}

Run the following (e.g. from the django shell)
{{{
from django.core.cache import cache

cache.add(""key"", ""value"", timeout=1)
time.sleep(2)
cache.touch(""key"", 60)
}}}

**Result:** The last `cache.touch` call raises ValueError: I/O operation on closed file

**Expected:** touch() to return False

**Stacktrace:**

{{{
Traceback (most recent call last):
  File ""<console>"", line 1, in <module>
  File "".../django_cache_test/.venv/lib/python3.13/site-packages/django/core/cache/backends/filebased.py"", line 76, in touch
    locks.unlock(f)
    ~~~~~~~~~~~~^^^
  File "".../django_cache_test/.venv/lib/python3.13/site-packages/django/core/files/locks.py"", line 127, in unlock
    fcntl.flock(_fd(f), fcntl.LOCK_UN)
                ~~~^^^
  File "".../django_cache_test/.venv/lib/python3.13/site-packages/django/core/files/locks.py"", line 27, in _fd
    return f.fileno() if hasattr(f, ""fileno"") else f
           ~~~~~~~~^^
ValueError: I/O operation on closed file
}}}


----


I assume the issue lies in the fileBasedCache class in `django/core/cache/backends/filebased.py`

{{{
try:
    locks.lock(f, locks.LOCK_EX)
    if self._is_expired(f):
        return False
    else:
        previous_value = pickle.loads(zlib.decompress(f.read()))
        f.seek(0)
        self._write_content(f, timeout, previous_value)
        return True
finally:
    locks.unlock(f)
}}}

`self._is_expired()` closes the file when it detects that the cache expired and returns False. The finally block is still executed and tries to access the previously closed file.
"	Bug	assigned	Core (Cache system)	6.0	Normal		cache, FileBasedCache, touch	Daniel	Accepted	1	0	0	0	1	0