storage: unsafe key mangling for MVCCIterator

[sumeerbhola]

It can uncover bugs in code that misuses unsafe
keys. It uncovered the bug fixed in
https://github.com/cockroachdb/cockroach/pull/60460/files#diff-84108c53fd1e766ef8802b87b394981d3497d87c40d86e084f2ed77bba0ca71a

Release note: None

[cockroach-teamcity]

This change is 

[knz]

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @sumeerbhola)

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pkg/storage/intent_interleaving_iter.go, line 902 at r3 (raw file):

	if rand.Intn(2) == 0 {
		for _, b := range [3][]byte{i.keyBuf, i.rawKeyBuf, i.rawMVCCKeyBuf} {
			// for _, b := range [3][]byte{i.keyBuf, i.rawKeyBuf, i.rawMVCCKeyBuf} {

don't forget to remove this before it merges

[sumeerbhola]

I forgot to mark this Do Not Merge. I've done that now. I had not added reviewers since this was an experiment for which I needed a full set of CI test runs -- is there is a simpler way to do that without creating a PR?

[knz]

Creating a PR is fine but github gives you the option to mark it as "draft" now so perhaps you could use that.

[sumeerbhola]

This is ready for a look. Reviewable is confused because of the history of this PR and shows too many files -- if one selects "combine commits for review", it will look sane.

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @itsbilal, @nvanbenschoten, @petermattis, and @sumeerbhola)

[nvanbenschoten]

cool idea! Does this have a noticeable impact on racetest duration?

Reviewed 1 of 4 files at r3, 3 of 18 files at r4.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @itsbilal, @petermattis, and @sumeerbhola)

[sumeerbhola]

TFTR!

Does this have a noticeable impact on racetest duration?

The racetests run for this PR look fast enough, with the slowest taking 7s
https://teamcity.cockroachdb.com/viewLog.html?buildId=2691122&buildTypeId=Cockroach_UnitTests_Testrace&tab=testsInfo

Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @itsbilal, @knz, and @petermattis)

---

pkg/storage/intent_interleaving_iter.go, line 902 at r3 (raw file):

Previously, knz (kena) wrote…

don't forget to remove this before it merges

Done.

[sumeerbhola]

bors r+

[craig]

Build failed (retrying...):

• GitHub CI (Cockroach)

[craig]

Build succeeded:

• GitHub CI (Cockroach)