pgsql: hash: Fix write-ahead logging bugs related to init forks.

hash: Fix write-ahead logging bugs related to init forks.

One, logging for CREATE INDEX was oblivious to the fact that when
an unlogged table is created, *only* operations on the init fork
should be logged.

Two, init fork buffers need to be flushed after they are written;
otherwise, a filesystem-level copy following recovery may do the
wrong thing. (There may be a better fix for this issue than the
one used here, but this is transposed from the similar logic already
present in XLogReadBufferForRedoExtended, and a broader refactoring
after beta2 seems inadvisable.)

Amit Kapila, reviewed by Ashutosh Sharma, Kyotaro Horiguchi,
and Michael Paquier

Discussion: http://postgr.es/m/CAA4eK1JpcMsEtOL_J7WODumeEfyrPi7FPYHeVdS7fyyrCrgp4w@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/09c2e7cd2ff0b884625c37ce8249832820c58710

Modified Files
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src/backend/access/hash/hash_xlog.c | 27 +++++++++++++++++++++++++++
src/backend/access/hash/hashpage.c | 23 ++++++++++++++++-------
2 files changed, 43 insertions(+), 7 deletions(-)