Fix bug in %r handling in recovery_end_command, it always came out as 0

because InRedo was cleared before recovery_end_command was executed.
Also, always take ControlFileLock when reading checkpoint location for
%r. That didn't matter before, but in 8.4 bgwriter is active during
recovery and can modify the control file concurrently.

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index d7aea24382df5167b11e35fc90d1d0285d7a3f47..43742370e8ae280703f5afe1f1b5058313eac863 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.345.2.7 2010/02/19 01:04:39 itagaki Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.345.2.8 2010/03/18 09:18:54 heikki Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2711,11 +2711,13 @@ RestoreArchivedFile(char *path, const char *xlogfname,
         */
        if (InRedo)
        {
+               LWLockAcquire(ControlFileLock, LW_SHARED);
                XLByteToSeg(ControlFile->checkPointCopy.redo,
                                        restartLog, restartSeg);
                XLogFileName(lastRestartPointFname,
                                         ControlFile->checkPointCopy.ThisTimeLineID,
                                         restartLog, restartSeg);
+               LWLockRelease(ControlFileLock);
                /* we shouldn't need anything earlier than last restart point */
                Assert(strcmp(lastRestartPointFname, xlogfname) <= 0);
        }
@@ -2905,28 +2907,14 @@ ExecuteRecoveryEndCommand(void)
         * Calculate the archive file cutoff point for use during log shipping
         * replication. All files earlier than this point can be deleted from the
         * archive, though there is no requirement to do so.
-        *
-        * We initialise this with the filename of an InvalidXLogRecPtr, which
-        * will prevent the deletion of any WAL files from the archive because of
-        * the alphabetic sorting property of WAL filenames.
-        *
-        * Once we have successfully located the redo pointer of the checkpoint
-        * from which we start recovery we never request a file prior to the redo
-        * pointer of the last restartpoint. When redo begins we know that we have
-        * successfully located it, so there is no need for additional status
-        * flags to signify the point when we can begin deleting WAL files from
-        * the archive.
         */
-       if (InRedo)
-       {
-               XLByteToSeg(ControlFile->checkPointCopy.redo,
-                                       restartLog, restartSeg);
-               XLogFileName(lastRestartPointFname,
-                                        ControlFile->checkPointCopy.ThisTimeLineID,
-                                        restartLog, restartSeg);
-       }
-       else
-               XLogFileName(lastRestartPointFname, 0, 0, 0);
+       LWLockAcquire(ControlFileLock, LW_SHARED);
+       XLByteToSeg(ControlFile->checkPointCopy.redo,
+                               restartLog, restartSeg);
+       XLogFileName(lastRestartPointFname,
+                                ControlFile->checkPointCopy.ThisTimeLineID,
+                                restartLog, restartSeg);
+       LWLockRelease(ControlFileLock);
 
        /*
         * construct the command to be executed