Reduce unnecessary PANIC to ERROR, improve a couple of comments.

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 6a656a3dbbd9bef429e0af8c762bbd09b0e8283a..42a4befba1ea04d69edb39bc16f7366056f33bf7 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.309 2008/05/14 14:02:57 mha Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.310 2008/05/16 19:15:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -67,6 +67,7 @@ bool      XLogArchiveMode = false;
 char      *XLogArchiveCommand = NULL;
 bool       fullPageWrites = true;
 bool       log_checkpoints = false;
+int        sync_method = DEFAULT_SYNC_METHOD;
 
 #ifdef WAL_DEBUG
 bool       XLOG_DEBUG = false;
@@ -88,8 +89,6 @@ bool      XLOG_DEBUG = false;
 /*
  * GUC support
  */
-int        sync_method = DEFAULT_SYNC_METHOD;
-
 const struct config_enum_entry sync_method_options[] = {
    {"fsync", SYNC_METHOD_FSYNC},
 #ifdef HAVE_FSYNC_WRITETHROUGH
@@ -1613,7 +1612,8 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible, bool xlog_switch)
         * have no open file or the wrong one.  However, we do not need to
         * fsync more than one file.
         */
-       if (sync_method != SYNC_METHOD_OPEN && sync_method != SYNC_METHOD_OPEN_DSYNC)
+       if (sync_method != SYNC_METHOD_OPEN &&
+           sync_method != SYNC_METHOD_OPEN_DSYNC)
        {
            if (openLogFile >= 0 &&
                !XLByteInPrevSeg(LogwrtResult.Write, openLogId, openLogSeg))
@@ -6340,10 +6340,10 @@ get_sync_bit(int method)
    switch (method)
    {
        /*
-        * Values for these sync options are defined even if they are not
-        * supported on the current platform. They are not included in
-        * the enum option array, and therefor will never be set if the
-        * platform doesn't support it.
+        * enum values for all sync options are defined even if they are not
+        * supported on the current platform.  But if not, they are not
+        * included in the enum option array, and therefore will never be seen
+        * here.
         */
        case SYNC_METHOD_FSYNC:
        case SYNC_METHOD_FSYNC_WRITETHROUGH:
@@ -6358,12 +6358,8 @@ get_sync_bit(int method)
            return OPEN_DATASYNC_FLAG;
 #endif
        default:
-           /* 
-            * This "can never happen", since the available values in
-            * new_sync_method are controlled by the available enum
-            * options.
-            */
-           elog(PANIC, "unrecognized wal_sync_method: %d", method);
+           /* can't happen (unless we are out of sync with option array) */
+           elog(ERROR, "unrecognized wal_sync_method: %d", method);
            return 0; /* silence warning */
    }
 }
@@ -6392,7 +6388,7 @@ assign_xlog_sync_method(int new_sync_method, bool doit, GucSource source)
                        (errcode_for_file_access(),
                         errmsg("could not fsync log file %u, segment %u: %m",
                                openLogId, openLogSeg)));
-           if (get_sync_bit(sync_method)  != get_sync_bit(new_sync_method))
+           if (get_sync_bit(sync_method) != get_sync_bit(new_sync_method))
                XLogFileClose();
        }
    }