kern/67919: Why nobody take serious to fix this bug?

Uwe Doering gemini at geminix.org
Mon Oct 31 07:08:43 PST 2005


Maxim Konovalov wrote:
> [...]
> 
>>>I was told the patch is incorrect.  It works in certain cases but
>>>incorrect in general.
>>
>>Why is it incorrect ? I'm using it for year.
> 
> Because you can't just throw away any chunk of data (e.g. it could be
> a meta-data) without a risk to damage a filesystem.

I wonder, could it really be meta-data?  I was under the impression that 
meta-data is a filesystem property and is therefore dealt with in the 
filesystem code, through i/o buffers.  Isn't the VM pager responsible 
for handling object contents (files etc.), only?  If so, it would be 
unfortunate to throw away pages of data but it certainly wouldn't damage 
the filesystem.

As to our own experience: Since I provided the patch a year ago or so 
we've had tons of users bumping against the space limit of their 
respective disk containers (with the VM pager involved: Berkeley DB 3, 
for instance) but not a single instance where the filesystem had been 
damaged by this incident.  This is on the 4.x branch.

    Uwe
-- 
Uwe Doering         |  EscapeBox - Managed On-Demand UNIX Servers
gemini at geminix.org  |  http://www.escapebox.net


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