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Prevent segfault after mmap failure #58
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the previous returned error will cause the db library to panic? if that is the case, shouldnt we fix that behavior instead?
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like if db fails on mmap, then all following calls into it should return mmap failure error instead of causing pancis?
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As far as I can tell, the reason is panics after returning the error is that calling
unmap
invalidatesdb.meta0
and/ordb.meta1
. So we could also fix this by modifying the logic to never access those variables ifmmap
fails, and put the db in an "error" state, as you suggested.That's probably a better solution than attempting to remap the old db. Just recently we received a bug report where it seems the remap failed as well, causing a panic. The one advantage of remapping is that you can still read from the db, you just can't write any more. But seeing as it's a failure state anyway, I don't think being able to read the db adds a ton of value.
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@lukechampine
You are right. I am fine with your current solution as I mentioned. But, I want to make sure this does fix the original issue. Also we need to have sort of a test for this ideally.
thank you!