Reduce PANIC to ERROR in several xlog routines that are used in both

critical and noncritical contexts (an example of noncritical being
post-checkpoint removal of dead xlog segments).  In the critical cases
the CRIT_SECTION mechanism will cause ERROR to be promoted to PANIC
anyway, and in the noncritical cases we shouldn't let an error take
down the entire database.  Arguably there should be *no* explicit
PANIC errors in this module, only more START/END_CRIT_SECTION calls,
but I didn't go that far.  (Yet.)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 37f6b59..ceeb768 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.185 2005/04/15 18:48:10 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.186 2005/04/15 22:19:48 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1152,6 +1152,9 @@ XLogWrite(XLogwrtRqst WriteRqst)
        bool            ispartialpage;
        bool            use_existent;
 
+       /* We should always be inside a critical section here */
+       Assert(CritSectionCount > 0);
+
        /*
         * Update local LogwrtResult (caller probably did this already,
         * but...)
@@ -1501,6 +1504,11 @@ XLogFlush(XLogRecPtr record)
  * caller must *not* hold the lock at call.
  *
  * Returns FD of opened file.
+ *
+ * Note: errors here are ERROR not PANIC because we might or might not be
+ * inside a critical section (eg, during checkpoint there is no reason to
+ * take down the system on failure).  They will promote to PANIC if we are
+ * in a critical section.
  */
 static int
 XLogFileInit(uint32 log, uint32 seg,
@@ -1528,7 +1536,7 @@ XLogFileInit(uint32 log, uint32 seg,
                if (fd < 0)
                {
                        if (errno != ENOENT)
-                               ereport(PANIC,
+                               ereport(ERROR,
                                                (errcode_for_file_access(),
                                                 errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
                                                                path, log, seg)));
@@ -1551,7 +1559,7 @@ XLogFileInit(uint32 log, uint32 seg,
        fd = BasicOpenFile(tmppath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
                                           S_IRUSR | S_IWUSR);
        if (fd < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not create file \"%s\": %m", tmppath)));
 
@@ -1580,19 +1588,19 @@ XLogFileInit(uint32 log, uint32 seg,
                        /* if write didn't set errno, assume problem is no disk space */
                        errno = save_errno ? save_errno : ENOSPC;
 
-                       ereport(PANIC,
+                       ereport(ERROR,
                                        (errcode_for_file_access(),
                                 errmsg("could not write to file \"%s\": %m", tmppath)));
                }
        }
 
        if (pg_fsync(fd) != 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not fsync file \"%s\": %m", tmppath)));
 
        if (close(fd))
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not close file \"%s\": %m", tmppath)));
 
@@ -1622,7 +1630,7 @@ XLogFileInit(uint32 log, uint32 seg,
        fd = BasicOpenFile(path, O_RDWR | PG_BINARY | XLOG_SYNC_BIT,
                                           S_IRUSR | S_IWUSR);
        if (fd < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
                           path, log, seg)));
@@ -1659,7 +1667,7 @@ XLogFileCopy(uint32 log, uint32 seg,
        XLogFilePath(path, srcTLI, srclog, srcseg);
        srcfd = BasicOpenFile(path, O_RDONLY | PG_BINARY, 0);
        if (srcfd < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not open file \"%s\": %m", path)));
 
@@ -1674,7 +1682,7 @@ XLogFileCopy(uint32 log, uint32 seg,
        fd = BasicOpenFile(tmppath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
                                           S_IRUSR | S_IWUSR);
        if (fd < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not create file \"%s\": %m", tmppath)));
 
@@ -1687,11 +1695,11 @@ XLogFileCopy(uint32 log, uint32 seg,
                if ((int) read(srcfd, buffer, sizeof(buffer)) != (int) sizeof(buffer))
                {
                        if (errno != 0)
-                               ereport(PANIC,
+                               ereport(ERROR,
                                                (errcode_for_file_access(),
                                                 errmsg("could not read file \"%s\": %m", path)));
                        else
-                               ereport(PANIC,
+                               ereport(ERROR,
                                         (errmsg("not enough data in file \"%s\"", path)));
                }
                errno = 0;
@@ -1707,19 +1715,19 @@ XLogFileCopy(uint32 log, uint32 seg,
                        /* if write didn't set errno, assume problem is no disk space */
                        errno = save_errno ? save_errno : ENOSPC;
 
-                       ereport(PANIC,
+                       ereport(ERROR,
                                        (errcode_for_file_access(),
                                 errmsg("could not write to file \"%s\": %m", tmppath)));
                }
        }
 
        if (pg_fsync(fd) != 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not fsync file \"%s\": %m", tmppath)));
 
        if (close(fd))
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not close file \"%s\": %m", tmppath)));
 
@@ -1729,7 +1737,7 @@ XLogFileCopy(uint32 log, uint32 seg,
         * Now move the segment into place with its final name.
         */
        if (!InstallXLogFileSegment(&log, &seg, tmppath, false, NULL, false))
-               elog(PANIC, "InstallXLogFileSegment should not have failed");
+               elog(ERROR, "InstallXLogFileSegment should not have failed");
 }
 
 /*
@@ -1806,14 +1814,14 @@ InstallXLogFileSegment(uint32 *log, uint32 *seg, char *tmppath,
         */
 #if HAVE_WORKING_LINK
        if (link(tmppath, path) < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not link file \"%s\" to \"%s\" (initialization of log file %u, segment %u): %m",
                                                tmppath, path, *log, *seg)));
        unlink(tmppath);
 #else
        if (rename(tmppath, path) < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not rename file \"%s\" to \"%s\" (initialization of log file %u, segment %u): %m",
                                                tmppath, path, *log, *seg)));
@@ -2205,6 +2213,12 @@ MoveOfflineLogs(uint32 log, uint32 seg, XLogRecPtr endptr,
                                                  (errmsg("recycled transaction log file \"%s\"",
                                                                  xlde->d_name)));
                                        (*nsegsrecycled)++;
+                                       /* Needn't recheck that slot on future iterations */
+                                       if (max_advance > 0)
+                                       {
+                                               NextLogSeg(endlogId, endlogSeg);
+                                               max_advance--;
+                                       }
                                }
                                else
                                {
@@ -2957,7 +2971,7 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
        fd = BasicOpenFile(tmppath, O_RDWR | O_CREAT | O_EXCL,
                                           S_IRUSR | S_IWUSR);
        if (fd < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not create file \"%s\": %m", tmppath)));
 
@@ -2976,7 +2990,7 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
        if (srcfd < 0)
        {
                if (errno != ENOENT)
-                       ereport(FATAL,
+                       ereport(ERROR,
                                        (errcode_for_file_access(),
                                         errmsg("could not open file \"%s\": %m", path)));
                /* Not there, so assume parent has no parents */
@@ -2988,7 +3002,7 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
                        errno = 0;
                        nbytes = (int) read(srcfd, buffer, sizeof(buffer));
                        if (nbytes < 0 || errno != 0)
-                               ereport(PANIC,
+                               ereport(ERROR,
                                                (errcode_for_file_access(),
                                                 errmsg("could not read file \"%s\": %m", path)));
                        if (nbytes == 0)
@@ -3010,7 +3024,7 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
                                 */
                                errno = save_errno ? save_errno : ENOSPC;
 
-                               ereport(PANIC,
+                               ereport(ERROR,
                                                (errcode_for_file_access(),
                                 errmsg("could not write to file \"%s\": %m", tmppath)));
                        }
@@ -3048,18 +3062,18 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
                /* if write didn't set errno, assume problem is no disk space */
                errno = save_errno ? save_errno : ENOSPC;
 
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not write to file \"%s\": %m", tmppath)));
        }
 
        if (pg_fsync(fd) != 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not fsync file \"%s\": %m", tmppath)));
 
        if (close(fd))
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not close file \"%s\": %m", tmppath)));
 
@@ -3076,14 +3090,14 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
         */
 #if HAVE_WORKING_LINK
        if (link(tmppath, path) < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not link file \"%s\" to \"%s\": %m",
                                                tmppath, path)));
        unlink(tmppath);
 #else
        if (rename(tmppath, path) < 0)
-               ereport(PANIC,
+               ereport(ERROR,
                                (errcode_for_file_access(),
                                 errmsg("could not rename file \"%s\" to \"%s\": %m",
                                                tmppath, path)));