@@ -154,9 +154,9 @@ GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
154154}
155155
156156/* -----------------------------------------------
157- *bt_page ()
157+ *bt_page_stats ()
158158 *
159- * Usage: SELECT * FROMbt_page ('t1_pkey', 1);
159+ * Usage: SELECT * FROMbt_page_stats ('t1_pkey', 1);
160160 * -----------------------------------------------
161161 */
162162Datum
@@ -202,13 +202,17 @@ bt_page_stats(PG_FUNCTION_ARGS)
202202CHECK_RELATION_BLOCK_RANGE (rel ,blkno );
203203
204204buffer = ReadBuffer (rel ,blkno );
205+ LockBuffer (buffer ,BUFFER_LOCK_SHARE );
205206
206207/* keep compiler quiet */
207208stat .btpo_prev = stat .btpo_next = InvalidBlockNumber ;
208209stat .btpo_flags = stat .free_size = stat .avg_item_size = 0 ;
209210
210211GetBTPageStatistics (blkno ,buffer ,& stat );
211212
213+ UnlockReleaseBuffer (buffer );
214+ relation_close (rel ,AccessShareLock );
215+
212216/* Build a tuple descriptor for our result type */
213217if (get_call_result_type (fcinfo ,NULL ,& tupleDesc )!= TYPEFUNC_COMPOSITE )
214218elog (ERROR ,"return type must be a row type" );
@@ -245,10 +249,6 @@ bt_page_stats(PG_FUNCTION_ARGS)
245249
246250result = HeapTupleGetDatum (tuple );
247251
248- ReleaseBuffer (buffer );
249-
250- relation_close (rel ,AccessShareLock );
251-
252252PG_RETURN_DATUM (result );
253253}
254254
@@ -320,6 +320,7 @@ bt_page_items(PG_FUNCTION_ARGS)
320320CHECK_RELATION_BLOCK_RANGE (rel ,blkno );
321321
322322buffer = ReadBuffer (rel ,blkno );
323+ LockBuffer (buffer ,BUFFER_LOCK_SHARE );
323324
324325/*
325326 * We copy the page into local storage to avoid holding pin on the
@@ -333,7 +334,7 @@ bt_page_items(PG_FUNCTION_ARGS)
333334uargs -> page = palloc (BLCKSZ );
334335memcpy (uargs -> page ,BufferGetPage (buffer ),BLCKSZ );
335336
336- ReleaseBuffer (buffer );
337+ UnlockReleaseBuffer (buffer );
337338relation_close (rel ,AccessShareLock );
338339
339340uargs -> offset = FirstOffsetNumber ;
@@ -464,6 +465,8 @@ bt_metap(PG_FUNCTION_ARGS)
464465errmsg ("cannot access temporary tables of other sessions" )));
465466
466467buffer = ReadBuffer (rel ,0 );
468+ LockBuffer (buffer ,BUFFER_LOCK_SHARE );
469+
467470page = BufferGetPage (buffer );
468471metad = BTPageGetMeta (page );
469472
@@ -490,8 +493,7 @@ bt_metap(PG_FUNCTION_ARGS)
490493
491494result = HeapTupleGetDatum (tuple );
492495
493- ReleaseBuffer (buffer );
494-
496+ UnlockReleaseBuffer (buffer );
495497relation_close (rel ,AccessShareLock );
496498
497499PG_RETURN_DATUM (result );