OSError on cache.delete [Errno 13] Permission denied

[grantjenks]

File "/home/grantj/repos/xxx/env27/lib/python2.7/site-packages/diskcache/djangocache.py", line 77, in delete
    self._cache.delete(key)
  File "/home/grantj/repos/xxx/env27/lib/python2.7/site-packages/diskcache/fanout.py", line 123, in delete
    return self.__delitem__(key)
  File "/home/grantj/repos/xxx/env27/lib/python2.7/site-packages/diskcache/fanout.py", line 111, in __delitem__
    return self._shards[index].__delitem__(key)
  File "/home/grantj/repos/xxx/env27/lib/python2.7/site-packages/diskcache/core.py", line 737, in __delitem__
    return self._delete(rowid, version, filename)
  File "/home/grantj/repos/xxx/env27/lib/python2.7/site-packages/diskcache/core.py", line 763, in _delete
    self._remove(filename)
  File "/home/grantj/repos/xxx/env27/lib/python2.7/site-packages/diskcache/core.py", line 790, in _remove
    os.remove(full_path)

OSError: [Errno 13] Permission denied: '/tmp/xxx-cache/003/e6/be/87b78c58d79c1a502b05ce645db8.val'

This is an odd error. On one particular server I get transient [Errno 13] Permission denied errors.

[grantjenks]

Hit it again. Odd that it hits on os.remove. I was able to reproduce in the shell on the server. But I screwed up while debugging and lost the reference. When it happens again it's worth debugging on the server. The key format is:

'thread-question-summary-%d-%s' % (thread_id, 'en')

[grantjenks]

This is odd:

In [23]: !ls -al /tmp/xxx-cache/000/8f/17/
total 16
drwxr-xr-x  2 grantj root 4096 Mar 23 19:55 .
drwxr-xr-x 48 grantj root 4096 Mar 27 15:12 ..
-rw-r--r--  1 grantj root 5740 Mar 23 19:55 cdc864e3de42f9a7578953f5f0c7.val

In [24]: !ls -al /tmp/xxx-cache/000/8f/f3/
total 12
drwxr-xr-x  2 root   root 4096 Mar 26 23:57 .
drwxr-xr-x 48 grantj root 4096 Mar 27 15:12 ..
-rw-r--r--  1 root   root 2732 Mar 26 23:57 c6f9cfb2aad602bb9a59db9ec183.val

Some cache values are stored as root. Not all are. Only the ones here. How does that happen?

If it now tries to delete the key at 000/8f/f3 then it raises OSError.

[grantjenks]

Attempted fix:

sudo find /tmp/xxx-cache/ -user root -type d -exec chown grantj:root {} \;
sudo find /tmp/xxx-cache/ -user root -type f -exec chown grantj:grantj {} \;

We'll see. It's otherwise very odd. Maybe I was debugging something and running uwsgi manually as root? I'm not sure.

[grantjenks]

Error happened again. I think it may be the crontab. Some management commands are run under root. I very much doubt this is a DiskCache bug.