Re: [PATCH] reload into If-None-Match

On 13/07/2013 12:31 a.m., Tsantilas Christos wrote:
> Hi all,
>
> Finally I did not apply the last patch I posted because I found a bug.
> Squid hits an assertion in clientReplyContext::processExpired at
> client_side_reply.cc:245,
> assert(http->storeEntry()->lastmod >= 0);
>
> Moreover looking in the code I am seeing that objects which does not
> have a "Last-Modified" header are never stored in squid cache.
> So in the patch I am posting here I removed the part of the patch which
> allowed to use a stored entry which does not have Last-Modified header
> but have a strong etag. This is the part which causes the assertion .
> Alternatively we can just remove the assertion.
>
> However still I do not know how an entry with lastmod=-1 (no
> Last-Modified header) found in my cache and causes the above assertion.
>
> Any opinion on this?

I expect it will be the same way the no-Date objects find their way in.
By being stored there temporarily while in-use by a client then RELEASEd
only after completion. If shutdown terminates Squid before that RELEASE
happens, or anything else stops it completing, they can be treated as
normal cache objects after next DIRTY restart.

I think we need someone to do a bit of analysis and check that Squid is
using Date properly as modified timestamp when Last-Modified is missing.

BTW: when you commit this If-None-Match patch please mark it --fixes
squid:2112 and close http://bugs.squid-cache.org/show_bug.cgi?id=2112

Amos
Received on Fri Jul 12 2013 - 16:48:57 MDT