postgres.git / summary / log / commit / refs

commit    aa04e5c3c1b1ba27d5e726d9afc291f475051ec0
Author:   Robert Haas <rhaas@postgresql.org>
Date:     Thu Dec 22 18:54:40 2016 +0000
First released in: 10.0, 9.2.20, 9.3.16, 9.4.11, 9.5.6, 9.6.2

    Fix broken error check in _hash_doinsert.
    
    You can't just cast a HashMetaPage to a Page, because the meta page
    data is stored after the page header, not at offset 0.  Fortunately,
    this didn't break anything because it happens to find hashm_bsize
    at the offset at which it expects to find pd_pagesize_version, and
    the values are close enough to the same that this works out.
    
    Still, it's a bug, so back-patch to all supported versions.
    
    Mithun Cy, revised a bit by me.


 src/backend/access/hash/hashinsert.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/backend/access/hash/hashinsert.c b/src/backend/access/hash/hashinsert.c
index 63aaec9f906..b133d4d7b2a 100644
--- a/src/backend/access/hash/hashinsert.c
+++ b/src/backend/access/hash/hashinsert.c
@@ -34,6 +34,7 @@ _hash_doinsert(Relation rel, IndexTuple itup)
 	BlockNumber blkno;
 	BlockNumber oldblkno = InvalidBlockNumber;
 	bool		retry = false;
+	Page		metapage;
 	Page		page;
 	HashPageOpaque pageopaque;
 	Size		itemsz;
@@ -53,7 +54,8 @@ _hash_doinsert(Relation rel, IndexTuple itup)
 
 	/* Read the metapage */
 	metabuf = _hash_getbuf(rel, HASH_METAPAGE, HASH_READ, LH_META_PAGE);
-	metap = HashPageGetMeta(BufferGetPage(metabuf));
+	metapage = BufferGetPage(metabuf);
+	metap = HashPageGetMeta(metapage);
 
 	/*
 	 * Check whether the item can fit on a hash page at all. (Eventually, we
@@ -62,11 +64,11 @@ _hash_doinsert(Relation rel, IndexTuple itup)
 	 *
 	 * XXX this is useless code if we are only storing hash keys.
 	 */
-	if (itemsz > HashMaxItemSize((Page) metap))
+	if (itemsz > HashMaxItemSize(metapage))
 		ereport(ERROR,
 				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
 				 errmsg("index row size %zu exceeds hash maximum %zu",
-						itemsz, HashMaxItemSize((Page) metap)),
+						itemsz, HashMaxItemSize(metapage)),
 			errhint("Values larger than a buffer page cannot be indexed.")));
 
 	/*


[parent: 80ca22aa60a6]