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[104.178.186.189]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7977e0eb111sm3509885a.89.2024.06.09.13.30.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 09 Jun 2024 13:30:27 -0700 (PDT) Date: Sun, 9 Jun 2024 16:30:25 -0400 From: Taylor Blau To: Junio C Hamano Cc: Jeff King , Kyle Lippincott , Git Mailing List Subject: Re: MSan failures in pack-bitmap Message-ID: References: <20240608081855.GA2390433@coredump.intra.peff.net> Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Sun, Jun 09, 2024 at 01:23:48PM -0700, Junio C Hamano wrote: > Taylor Blau writes: > > > I don't think the issue here is a corrupt on-disk bitmap or MIDX. The > > regression that Kyle reported was a logic issue reading a > > ordinary/non-corrupt MIDX file, not a result of some on-disk corruption. > > ... > > But I do not think that repository corruption is a likely outcome here, > > Yes, exactly. What I was asking was how on-disk corruption that > would result from the logic issue of reading a correct MIDX file. OK, I think I misunderstood your original email. > ... there is no reasonable work around here, is there? We do not > even know exactly what kind of breakage this will cause (which is > expected, as we would be "reading" a garbage value and basing future > actions on it)? I think the end-result would be that packs sent between client and server during fetches or pushes would be broken, resulting in index-pack failing to index them, thus causing one side or the other to (correctly) throw away the received pack. The only thing I can think of to avoid this would be to enable multi-pack reuse, which is only possible if your MIDX has a BTMP chunk. The other work around would be to disable pack-reuse altogether, which is very unfortunate. Thanks, Taylor