svn commit: r295800 - head/usr.bin/cap_mkdb

[Eric van Gyzen]

On 2/19/16 6:40 PM, Bryan Drewery wrote:
> On 2/19/2016 12:42 AM, Stefan Esser wrote:
>> Author: se
>> Date: Fri Feb 19 08:42:13 2016
>> New Revision: 295800
>> URL: https://svnweb.freebsd.org/changeset/base/295800
>>
>> Log:
>>    Remove O_SYNC from the options passed to dbmopen().
> Uh, this is a full revert of r293312's changes to cap_mkdb which were
> made for good reason. So this seems simply wrong without a better fix.
>
>>    
>>    The output file is created as a temporary file that is moved over the
>>    existing file after completion. Thus there is no need to immediately
>>    flush all created db records to the temporary file.
> This is not right either. Depending on the use of soft updates /
> journaling the data and metadata (file name / rename) may be written at
> different times. It is entirely possible to get a renamed file with no
> or junk content without an fsync. That's exactly what r293312 mentions
> in its commit message.

dwmalone@ plans to put the fsync() in the db close method, which makes a lot of 
sense, and would fix this in a better way.

     https://reviews.freebsd.org/D5186

This commit probably should have waited for D5186 to be committed, but at least 
that seems imminent.

Eric