In the bus_internal.h,I see
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Note: Buffer header lock (BM_LOCKED flag) must be held to examine or change tag, state or wait_backend_pgprocno fields.
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As we all know, this buffer header lock is implemented by a bit in state filed, and this state field is a atomic_u32 type, so in fact we don’t need to
hold buffer lock when we update state, this comment has error，right?
