Re: [HACKERS] [PATCH] Assert that the correct locks are held whencalling PageGetLSN()

So ... gistdoinsert can sometimes hold an exclusive lock, so we could do
this instead:

diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 0e499598a4..2ea19d2683 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -566,7 +566,8 @@ gistdoinsert(Relation r, IndexTuple itup, Size freespace, GISTSTATE *giststate)
        }
 
        stack->page = (Page) BufferGetPage(stack->buffer);
-       stack->lsn = PageGetLSN(stack->page);
+       stack->lsn = xlocked ?
+           PageGetLSN(stack->page) : BufferGetLSNAtomic(stack->buffer);
        Assert(!RelationNeedsWAL(state.r) || !XLogRecPtrIsInvalid(stack->lsn));
 
I suppose it doesn't really hurt all that much.  I admit I'm a bit
nervous about the fact that code is uncovered.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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