Re: [libvirt] [PATCH] util: Don't delete the original file for truncation
On Tue, Aug 21, 2018 at 10:49:28AM +0200, Marc Hartmayer wrote:
Truncate means that if a file exists it's length will be
truncated to
0, but the mode and the owner shall be unchanged. The current behavior
is that the original file is deleted and a new file is created. Let's
fix this by using O_TRUNC.
This is just describing what you've changed, leaving out why you are
trying todo this ?
The function virRotatingFileWriterDelete is now unused but may be
used
in the future and is therefore still defined.
Signed-off-by: Marc Hartmayer <mhartmay(a)linux.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy(a)linux.ibm.com>
---
Note:
This change has the (potentially unwanted) security effect that the
owner/group of the log file does not change. Before this patch the old
log file was deleted and the newly created log file was owned by the
virtlogd user. Now, if a user has created the log file before, he can
read the logs. If we don't wanna have this effect we can either
adjust/add a virtlogd API or do a chown within the calling driver
(e.g. QEMU driver).
Pre-creating the log file and/or messing around with ownership are
not things we ever intended to support.
Regards,
Daniel
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