cli: ensure that 'snapshot save' is fsync safe and also only writes to the requested file on success #7698
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…o the requested file on success
rboyer
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…o the requested file on success (#7698)
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Now we will write to
${user_requested_file}.unverifiedinitially. When that's complete we ensure the bytes have hit the disk (fsync) and have to pass the snapshot verification process on re-read BEFORE we actually rename it to the actual${user_requested_file}.This ensures that the snapshot filename only ever either exists and is verified or never exists.