Version:           4.7 (using KDE 4.7.1) 
OS:                Linux

Hello,

Recently I had been experiencing a problem where .xsession-errors was being spammed by applications and filling up my / in less than an hour. In such a situation, KDE will prompt you saying my disk is full, please use a file manager to free up space. So I would open Dolphin, see .xsession-errors is huge, and delete it expecting things to get better. In general, they didn't. Here are some specific examples.

* The disk usage progress bar in Dolphin would still report 0 Bytes free.
* Dolphin would refuse to create new files reporting the disk was full.
* Rekonq would not be able to save bookmarks when it closed.
* KTorrent would not continue torrenting as the disk was full.
* Konsole would hang while openning. The UI would load, but it wouldn't create a new shell instance.
* Systemsettings would not report an error when trying to Apply a settings change.
* Rarely, applications would mangle their config files on closing.
* Could not logout or reboot via the KDE interface. The logout process would hang at a black screen with a mouse cursor.

It should be noted that ~80GiB of disk space would be available when this is happening. CLI tools are all able to work as expected.  KDE just doesn't seem to get the message that there is disk space again.

Reproducible: Always

Steps to Reproduce:
1. Fill up your hard disk somehow (perhaps create a very large file).
2. Notice KDE reports that your disk is full.
3. Cleanup some space.
4. Run various KDE apps.
5. Try to get the app to write to disk (eg save a file).
6. Notice they correctly report the disk is full.
7. Free up disk space.
8. Repeat step 5.

Actual Results:  
The KDE application will report that it cannot write to disk because the disk is full.

Expected Results:  
The KDE application successfully writes to disk.