Hi,
On Sun, 10 Aug 2008, Nicolas Pitre wrote:
> On Fri, 8 Aug 2008, Johannes Schindelin wrote:
>
> > In any case, the pack is too large for me to let my computer repack
> > everything, when only one object needs repacking.
>
> By that you mean you cannot/don't want to use repack -f, right?
Right. However, I had a relatively fast machine standing nearby today,
so that scp was not too painful.
> There _could_ be a way to hack pack-objects so not to reuse bad objects.
> However I don't want that to impact the code too much for an event that
> hopefully should almost never happens, especially if using -f does work
> around it already.
>
> Well, let's see.
>
> [...]
>
> OK, here's what the patch to allow repacking without -f and still using
> redundant objects in presence of pack corruption might look like.
> Please tell me if that works for you.
The testing took quite a while unfortunately, mainly because I followed
Shawn's advice, and added not only a loose object, but also a single pack
with the single object in it, and a newer timestamp.
This resulted in my CPU being hogged when Git tried to read the object. I
do not know exactly what is happening, but I suspect an infinite loop due
to the funny interaction between a valid and a corrupt pack containing the
same object. Or maybe the issue described later in this mail.
Only when I removed the pack did things actually go further, so there is
still a bug lurking.
Your patch worked _almost_:
> offset += entry->in_pack_header_size;
> datalen -= entry->in_pack_header_size;
> + if (!pack_to_stdout && p->index_version == 1 &&
> + check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
> + die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
This needs to be an error(), obviously.
> + if (entry->delta)
> + reused_delta--;
> + goto no_reuse;
> + }
> +
> if (type == OBJ_OFS_DELTA) {
> off_t ofs = entry->idx.offset - entry->delta->idx.offset;
> unsigned pos = sizeof(dheader) - 1;
With that, it took quite a while, then it told me about the corrupt
object.
And then it hangs in the loop sha1_file.c:1511. The function inflate()
returns Z_BUF_ERROR, and nothing is read.
Oh, and it still tries to access the same corrupt pack.
Thanks,
Dscho
P.S.: I have to wrap up my work at my current (interim) job, and will be
moving in the next days, so do not expect too much from my side before
Monday.
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
