* NB: caller must not hold lock on metapage, nor on page, that's next to
* ovflbuf in the bucket chain. We don't acquire the lock on page that's
* prior to ovflbuf in chain if it is same as wbuf because the caller already
- * has a lock on same. This function releases the lock on wbuf and caller
- * is responsible for releasing the pin on same.
+ * has a lock on same.
*/
BlockNumber
_hash_freeovflpage(Relation rel, Buffer ovflbuf, Buffer wbuf,
- bool wbuf_dirty, BufferAccessStrategy bstrategy)
+ BufferAccessStrategy bstrategy)
{
HashMetaPage metap;
Buffer metabuf;
Assert(prevopaque->hasho_bucket == bucket);
prevopaque->hasho_nextblkno = nextblkno;
+ MarkBufferDirty(prevbuf);
if (prevblkno != writeblkno)
- {
- MarkBufferDirty(prevbuf);
_hash_relbuf(rel, prevbuf);
- }
- else
- {
- /* ensure to mark prevbuf as dirty */
- wbuf_dirty = true;
- }
}
-
- /* write and unlock the write buffer */
- if (wbuf_dirty)
- _hash_chgbufaccess(rel, wbuf, HASH_WRITE, HASH_NOLOCK);
- else
- _hash_chgbufaccess(rel, wbuf, HASH_READ, HASH_NOLOCK);
-
if (BlockNumberIsValid(nextblkno))
{
Buffer nextbuf = _hash_getbuf_with_strategy(rel,
* Tricky point here: if our read and write pages are adjacent in the
* bucket chain, our write lock on wbuf will conflict with
* _hash_freeovflpage's attempt to update the sibling links of the
- * removed page. In that case, we don't need to lock it again and we
- * always release the lock on wbuf in _hash_freeovflpage and then
- * retake it again here. This will not only simplify the code, but is
- * required to atomically log the changes which will be helpful when
- * we write WAL for hash indexes.
+ * removed page. In that case, we don't need to lock it again.
*/
rblkno = ropaque->hasho_prevblkno;
Assert(BlockNumberIsValid(rblkno));
/* free this overflow page (releases rbuf) */
- _hash_freeovflpage(rel, rbuf, wbuf, wbuf_dirty, bstrategy);
+ _hash_freeovflpage(rel, rbuf, wbuf, bstrategy);
+
+ if (wbuf_dirty)
+ MarkBufferDirty(wbuf);
/* are we freeing the page adjacent to wbuf? */
if (rblkno == wblkno)
{
/* retain the pin on primary bucket page till end of bucket scan */
- if (wblkno != bucket_blkno)
- _hash_dropbuf(rel, wbuf);
+ if (wblkno == bucket_blkno)
+ _hash_chgbufaccess(rel, wbuf, HASH_READ, HASH_NOLOCK);
+ else
+ _hash_relbuf(rel, wbuf);
return;
}
- /* lock the overflow page being written, then get the previous one */
- _hash_chgbufaccess(rel, wbuf, HASH_NOLOCK, HASH_WRITE);
-
rbuf = _hash_getbuf_with_strategy(rel,
rblkno,
HASH_WRITE,
/* hashovfl.c */
extern Buffer _hash_addovflpage(Relation rel, Buffer metabuf, Buffer buf, bool retain_pin);
extern BlockNumber _hash_freeovflpage(Relation rel, Buffer ovflbuf, Buffer wbuf,
- bool wbuf_dirty, BufferAccessStrategy bstrategy);
+ BufferAccessStrategy bstrategy);
extern void _hash_initbitmap(Relation rel, HashMetaPage metap,
BlockNumber blkno, ForkNumber forkNum);
extern void _hash_squeezebucket(Relation rel,