Re: [PATCH 3/4] repack: use tempfiles for signal cleanup
- From
Jeff King <peff@peff.net>
- Date
- Oct 22, 2022, 00:11 UTC
- Message-ID
- <Y1M1HFbmygJDZWYh@coredump.intra.peff.net>
- In-Reply-To
- <Y1MqPjnYoWcOgXo6@coredump.intra.peff.net>
On Fri, Oct 21, 2022 at 07:24:46PM -0400, Jeff King wrote:
Show 23 quoted lines
> > > @@ -1020,14 +1011,14 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
> > > fname_old = mkpathdup("%s-%s%s",
> > > packtmp, item->string, exts[ext].name);
> > >
> > > - if (data->exts[ext]) {
> > > + if (data->tempfiles[ext]) {
> > > struct stat statbuffer;
> > > if (!stat(fname_old, &statbuffer)) {
> > > statbuffer.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
> > > chmod(fname_old, statbuffer.st_mode);
> > > }
> > >
> > > - if (rename(fname_old, fname))
> > > + if (rename_tempfile(&data->tempfiles[ext], fname))
> > > die_errno(_("renaming '%s' failed"), fname_old);
> >
> > It now got a bit confusing that we have 'fname', 'fname_old', and
> > the tempfile. The path.buf used as the argument to register_tempfile()
> > matches what is used to compute fname_old above. I wonder if tempfile
> > API does not give us that name so that we can stop using fname_old here?
>
> It does, and we probably should use get_tempfile_path() in the error
> message here.Gah, this is not quite true. If the rename fails, we clean up the tempfile struct entirely, and that invalidates the pointer. I think it is OK to just report "fname" in this case, though, which is what most callers do. Arguably the tempfile API should leave the tempfile in place on a failed rename, letting the callers decide themselves how to handle things. In most cases they'll just exit anyway, which will clean up the tempfile.
I also didn't notice that we do some mode-twiddling on fname_old. But I think if the code becomes (inside this conditional block, once we stop using it in the other half):
const char *fname_old = get_tempfile_path(data->tempfiles[ext]);
then those lines don't even need to change.
-Peff