From fcbf455842eac10c331a866f559bb3875bcb8c37 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 13 Aug 2015 00:12:07 -0300
Subject: [PATCH] Fix unitialized variables
As complained by clang, reported by Andres Freund. Brown paper bag bug
in ccc4c074994d.
Add some comments, too.
Backpatch to 9.5, like that one.
---
src/backend/access/brin/brin_pageops.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/src/backend/access/brin/brin_pageops.c b/src/backend/access/brin/brin_pageops.c
index 875544e336c..6a2fd474d9a 100644
--- a/src/backend/access/brin/brin_pageops.c
+++ b/src/backend/access/brin/brin_pageops.c
@@ -86,6 +86,7 @@ brin_doupdate(Relation idxrel, BlockNumber pagesPerRange,
{
LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
newbuf = InvalidBuffer;
+ extended = false;
}
oldpage = BufferGetPage(oldbuf);
oldlp = PageGetItemId(oldpage, oldoff);
@@ -335,9 +336,8 @@ brin_doinsert(Relation idxrel, BlockNumber pagesPerRange,
brinRevmapExtend(revmap, heapBlk);
/*
- * Obtain a locked buffer to insert the new tuple. Note
- * brin_getinsertbuffer ensures there's enough space in the returned
- * buffer.
+ * Acquire lock on buffer supplied by caller, if any. If it doesn't have
+ * enough space, unpin it to obtain a new one below.
*/
if (BufferIsValid(*buffer))
{
@@ -354,12 +354,18 @@ brin_doinsert(Relation idxrel, BlockNumber pagesPerRange,
}
}
+ /*
+ * If we still don't have a usable buffer, have brin_getinsertbuffer
+ * obtain one for us.
+ */
if (!BufferIsValid(*buffer))
{
*buffer = brin_getinsertbuffer(idxrel, InvalidBuffer, itemsz, &extended);
Assert(BufferIsValid(*buffer));
Assert(extended || br_page_get_freespace(BufferGetPage(*buffer)) >= itemsz);
}
+ else
+ extended = false;
/* Now obtain lock on revmap buffer */
revmapbuf = brinLockRevmapPageForUpdate(revmap, heapBlk);
@@ -367,6 +373,7 @@ brin_doinsert(Relation idxrel, BlockNumber pagesPerRange,
page = BufferGetPage(*buffer);
blk = BufferGetBlockNumber(*buffer);
+ /* Execute the actual insertion */
START_CRIT_SECTION();
if (extended)
brin_page_init(BufferGetPage(*buffer), BRIN_PAGETYPE_REGULAR);
--
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