From: Derrick Stolee Date: Tue, 21 Aug 2018 13:53:44 GMT Subject: Re: [PATCH 3/9] midx: mark bad packed objects Message-ID: In-Reply-To: On 8/20/2018 5:23 PM, Stefan Beller wrote: > On Mon, Aug 20, 2018 at 9:52 AM Derrick Stolee wrote: >> When an object fails to decompress from a pack-file, we mark the object >> as 'bad' so we can retry with a different copy of the object (if such a >> copy exists). >> >> Before now, the multi-pack-index did not update the bad objects list for >> the pack-files it contains, and we did not check the bad objects list >> when reading an object. Now, do both. > This sounds like a bug fix unlike patches 1 & 2 that sound like > feature work(2) or making code more readable(1). > (After studying the code, this doesn't sound like a bug fix any more, > but a safety thing) It is a safety thing. One codepath that needs this includes this comment:             /*              * We're probably in deep shit, but let's try to fetch              * the required base anyway from another pack or loose.              * This is costly but should happen only in the presence              * of a corrupted pack, and is better than failing outright.              */ This goes back to 8eca0b47: implement some resilience against pack corruptions. The logic is tested in t5303-pack-corruption-resilience.sh, with the test title '... and a redundant pack allows for full recovery too'. > Is it worth having this on a separate track coming in > faster than the rest of this series? ds/multi-pack-index is cooking in 'next' until after 2.19.0, so I'm not sure it's worth splitting things up at this point. >> Signed-off-by: Derrick Stolee >> --- >> midx.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/midx.c b/midx.c >> index 6824acf5f8..7fa75a37a3 100644 >> --- a/midx.c >> +++ b/midx.c >> @@ -280,6 +280,16 @@ static int nth_midxed_pack_entry(struct multi_pack_index *m, struct pack_entry * >> if (!is_pack_valid(p)) >> return 0; >> >> + if (p->num_bad_objects) { >> + uint32_t i; > Is there a reason that i needs to be if 32 bits? > Would size_t (for iterating) or 'int' (as a default > like in many for loops) be ok, too? i is bounded by p->num_bad_objects, which is also uint32_t. Thanks, -Stolee