Re: Funny error with git gc...

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: May 23, 2009, 16:02 UTC
Message-ID: <alpine.LFD.2.01.0905230859290.3555@localhost.localdomain>
In-Reply-To: <alpine.DEB.1.00.0905231050480.9099@intel-tinevez-2-302>

On Sat, 23 May 2009, Johannes Schindelin wrote:

Show 18 quoted lines

> On Fri, 15 May 2009, Linus Torvalds wrote:
> 
> > On Fri, 15 May 2009, Johannes Schindelin wrote:
> > >  
> > >  	fd = mkstemp(template);
> > > +	if (fd < 0) {
> > > +		release_pack_memory((size_t)-1ll, -1);
> > > +		fd = mkstemp(template);
> > 
> > This is wrong. You can't use "template" twice. You need to re-initialize 
> > it. The first one will blow away the XXXX pattern.
> 
> Turns out that would be awkward, as the xmkstemp() function would have to 
> copy the template just in case mkstemp() fails due to too many open files, 
> and of course it would need to release the copy afterwards.
> 
> OTOH we cannot just use the initialized filename, because there 
> might be a race condition with another process, right?

Correct. You basically need to have the caller re-create the template. We already do that in some other cases: see odb_mkstemp(), or create_tempfile(). Both of them do that template re-creation on failure, and try again.

You could save off the template into a local temporary array, of course.

		Linus