Bug 1374550

Description of problem:

If logrotate is using copytruncate, and the copy fails (for example, due to disk full), logrotate can leave behind partially written files.  Unfortunately, these partially written files prevent logrotate from rotating the affected log file again, requiring manual assistance.

Version-Release number of selected component (if applicable):

logrotate-3.8.6-7.el7_2.x86_64

How reproducible:

Every time (albeit requiring a disk full or close to disk full situation)

Steps to Reproduce:
1. echo foobar > /var/log/foobar.log

2. dd if=/dev/zero of=/var/log/fill-this-disk
   (wait for it to fill the disk and eventually fail)

3. logrotate -f /etc/logrotate.conf

   Fails for foobar.log with:
   error: error writing to /var/log/foobar.log.1: No space left on device

Actual results:

After following the steps above, logrotate cannot rotate foobar.log any longer.  Even once the disk-full situation is addressed (for this example just rm /var/log/fill-this-disk), it will always fail to rotate that log file with:

  error: error creating output file /var/log/foobar.log.1: File exists

Filling the whole disk via dd is just an example to force the problem to happen.  It can happen naturally if the log file in question is large enough.

Expected results:

If logrotate created foobar.log.1 and could not successfully write to it, it should clean up after itself and delete it.

Additional info:

This is the config I used for foobar.log:

# cat /etc/logrotate.d/foobar
/var/log/foobar.log {
    rotate 10
    size 10M
    create
    copytruncate
}

Note that essentially the same thing happens using "delaycompress".  Using the above config, remove "copytruncate" and add "compress" and "delaycompress" and follow these steps:

1. echo "foobar" > /var/log/foobar.log
2. logrotate -f /etc/logrotate.conf
3. dd if=/dev/zero of=/var/log/fill-this-disk
2. logrotate -f /etc/logrotate.conf
4. rm /var/log/fill-this-disk

# logrotate -f /etc/logrotate.conf
error: error creating output file /var/log/foobar.log.1.gz: File exists