Centralize timestamp computation of control file on updates

This commit moves the timestamp computation of the control file within
the routine of src/common/ in charge of updating the backend's control
file, which is shared by multiple frontend tools (pg_rewind,
pg_checksums and pg_resetwal) and the backend itself.

This change has as direct effect to update the control file's timestamp
when writing the control file in pg_rewind and pg_checksums, something
that is helpful to keep track of control file updates for those
operations, something also tracked by the backend at startup within its
logs.  This part is arguably a bug, as ControlFileData->time should be
updated each time a new version of the control file is written, but this
is a behavior change so no backpatch is done.

Author: Amul Sul
Reviewed-by: Nathan Bossart, Michael Paquier, Bharath Rupireddy
Discussion: https://postgr.es/m/CAAJ_b97nd_ghRpyFV9Djf9RLXkoTbOUqnocq11WGq9TisX09Fw@mail.gmail.com

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index b54ec54970551b5c31b45660d150490923f83ede..b980c6ac21c7ccfda2b4bf82f20677ec303cb01d 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7339,7 +7339,7 @@ StartupXLOG(void)
                                ControlFile->backupEndPoint = ControlFile->minRecoveryPoint;
                        }
                }
-               ControlFile->time = (pg_time_t) time(NULL);
+
                /* No need to hold ControlFileLock yet, we aren't up far enough */
                UpdateControlFile();
 
@@ -8199,7 +8199,6 @@ StartupXLOG(void)
         */
        LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
        ControlFile->state = DB_IN_PRODUCTION;
-       ControlFile->time = (pg_time_t) time(NULL);
 
        SpinLockAcquire(&XLogCtl->info_lck);
        XLogCtl->SharedRecoveryState = RECOVERY_STATE_DONE;
@@ -9142,7 +9141,6 @@ CreateCheckPoint(int flags)
        {
                LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
                ControlFile->state = DB_SHUTDOWNING;
-               ControlFile->time = (pg_time_t) time(NULL);
                UpdateControlFile();
                LWLockRelease(ControlFileLock);
        }
@@ -9412,7 +9410,6 @@ CreateCheckPoint(int flags)
                ControlFile->state = DB_SHUTDOWNED;
        ControlFile->checkPoint = ProcLastRecPtr;
        ControlFile->checkPointCopy = checkPoint;
-       ControlFile->time = (pg_time_t) time(NULL);
        /* crash recovery should always recover to the end of WAL */
        ControlFile->minRecoveryPoint = InvalidXLogRecPtr;
        ControlFile->minRecoveryPointTLI = 0;
@@ -9539,7 +9536,6 @@ CreateEndOfRecoveryRecord(void)
         * changes to this point.
         */
        LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
-       ControlFile->time = (pg_time_t) time(NULL);
        ControlFile->minRecoveryPoint = recptr;
        ControlFile->minRecoveryPointTLI = xlrec.ThisTimeLineID;
        UpdateControlFile();
@@ -9740,7 +9736,6 @@ CreateRestartPoint(int flags)
                {
                        LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
                        ControlFile->state = DB_SHUTDOWNED_IN_RECOVERY;
-                       ControlFile->time = (pg_time_t) time(NULL);
                        UpdateControlFile();
                        LWLockRelease(ControlFileLock);
                }
@@ -9801,7 +9796,6 @@ CreateRestartPoint(int flags)
        {
                ControlFile->checkPoint = lastCheckPointRecPtr;
                ControlFile->checkPointCopy = lastCheckPoint;
-               ControlFile->time = (pg_time_t) time(NULL);
 
                /*
                 * Ensure minRecoveryPoint is past the checkpoint record.  Normally,

diff --git a/src/bin/pg_resetwal/pg_resetwal.c b/src/bin/pg_resetwal/pg_resetwal.c
index 84b6f70ad6a7c91ce0fd8ed831628155adac922c..c0ab392c3a2959ad7d90a70a95961baf50fb6d0c 100644 (file)
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -911,7 +911,6 @@ RewriteControlFile(void)
        ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
 
        ControlFile.state = DB_SHUTDOWNED;
-       ControlFile.time = (pg_time_t) time(NULL);
        ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
        ControlFile.minRecoveryPoint = 0;
        ControlFile.minRecoveryPointTLI = 0;

diff --git a/src/common/controldata_utils.c b/src/common/controldata_utils.c
index 7d4af7881ea50319a4a69818de28e06829387380..4ce097c05cea937fa1208f388408696169211e90 100644 (file)
--- a/src/common/controldata_utils.c
+++ b/src/common/controldata_utils.c
@@ -23,6 +23,7 @@
 #include <unistd.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <time.h>
 
 #include "access/xlog_internal.h"
 #include "catalog/pg_control.h"
@@ -168,6 +169,9 @@ update_controlfile(const char *DataDir,
        StaticAssertStmt(sizeof(ControlFileData) <= PG_CONTROL_FILE_SIZE,
                                         "sizeof(ControlFileData) exceeds PG_CONTROL_FILE_SIZE");
 
+       /* Update timestamp  */
+       ControlFile->time = (pg_time_t) time(NULL);
+
        /* Recalculate CRC of control file */
        INIT_CRC32C(ControlFile->crc);
        COMP_CRC32C(ControlFile->crc,