consensus: don't call GetBlockPos in ReadBlockFromDisk without cs_main lock #22895

Commit ccd8ef65 "Reduce cs_main lock in ReadBlockFromDisk, only read GetBlockPos under the lock" in #11281 moved the cs_main lock from caller to ReadBlockFromDisk() for calling CBlockIndex::GetBlockPos(), but the second invocation doesn't have the lock, and IIUC there is no guarantee the compiler can know if state has changed.

Use the blockPos local variable instead, rename it to block_pos, and make it const.

Code-review ACK 350e034e64d175f3db4c85ddca42e76e279912f6

Good catch!

Code review ACK 350e034e64d175f3db4c85ddca42e76e279912f6.

Shouldn't there be a lock annotation to prevent this in the future?

Shouldn't there be a lock annotation to prevent this in the future?

Proposed in #22932.

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Conflicts

Reviewers, this pull request conflicts with the following ones:

• #9245 (Drop IO priority to idle while reading blocks for peer requests and startup verification by luke-jr)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

Code review ACK 350e034e64d175f3db4c85ddca42e76e279912f6