Back-patch fix for bogus clearing of BufferDirtiedByMe.

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 3f659ada4613e16e10779e3bec8ca0a14fc2bd77..8390feeaa4291430e160461457e4bd8540da1727 100644 (file)
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.81.2.2 2000/10/04 07:50:00 inoue Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.81.2.3 2000/10/22 20:33:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1656,7 +1656,6 @@ recheck:
                        }
                        /* Now we can do what we came for */
                        buf->flags &= ~(BM_DIRTY | BM_JUST_DIRTIED);
-                       ClearBufferDirtiedByMe(i, buf);
 
                        /*
                         * Release any refcount we may have.
@@ -1680,7 +1679,23 @@ recheck:
                         */
                        BufTableDelete(buf);
                }
+
+               /*
+                * Also check to see if BufferDirtiedByMe info for this buffer
+                * refers to the target relation, and clear it if so.  This is
+                * independent of whether the current contents of the buffer
+                * belong to the target relation!
+                *
+                * NOTE: we have no way to clear BufferDirtiedByMe info in other
+                * backends, but hopefully there are none with that bit set for
+                * this rel, since we hold exclusive lock on this rel.
+                */
+               if (BufferTagLastDirtied[i - 1].relId.relId == relid &&
+                       (BufferTagLastDirtied[i - 1].relId.dbId == MyDatabaseId ||
+                        BufferTagLastDirtied[i - 1].relId.dbId == (Oid) NULL))
+                       BufferDirtiedByMe[i - 1] = false;
        }
+
        SpinRelease(BufMgrLock);
 }
 
@@ -1726,7 +1741,6 @@ recheck:
                        }
                        /* Now we can do what we came for */
                        buf->flags &= ~(BM_DIRTY | BM_JUST_DIRTIED);
-                       ClearBufferDirtiedByMe(i, buf);
 
                        /*
                         * The thing should be free, if caller has checked that no
@@ -1738,7 +1752,20 @@ recheck:
                         */
                        BufTableDelete(buf);
                }
+
+               /*
+                * Also check to see if BufferDirtiedByMe info for this buffer
+                * refers to the target database, and clear it if so.  This is
+                * independent of whether the current contents of the buffer
+                * belong to the target database!
+                *
+                * (Actually, this is probably unnecessary, since I shouldn't have
+                * ever dirtied pages of the target database, but...)
+                */
+               if (BufferTagLastDirtied[i - 1].relId.dbId == dbid)
+                       BufferDirtiedByMe[i - 1] = false;
        }
+
        SpinRelease(BufMgrLock);
 }