pgsql: bufmgr: Introduce FlushUnlockedBuffer

bufmgr: Introduce FlushUnlockedBuffer

There were several copies of code locking a buffer, flushing its contents, and
unlocking the buffer. It seems worth centralizing that into a helper function.

Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/fvfmkr5kk4nyex56ejgxj3uzi63isfxovp2biecb4bspbjrze7@az2pljabhnff

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/3c2b97b29ee33d5619779fd10e06eee07d4700da

Modified Files
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src/backend/storage/buffer/bufmgr.c | 36 ++++++++++++++++++++----------------
1 file changed, 20 insertions(+), 16 deletions(-)