From 628d791b26062945fad4afa5985f6b84f46f16d4 Mon Sep 17 00:00:00 2001

From: Jiri Vymazal <jvymazal@redhat.com>

Date: Tue, 23 Jul 2019 11:28:31 +0200

Subject: [PATCH] Add "fsync" option for imjournal

The new option makes possible to force physical write of stateFile

to persistent storage, ensuring we do not lose/duplicate messages

in case of hard crash or power loss.

---

 plugins/imjournal/imjournal.c | 41 +++++++++++++++----

 1 file changed, 32 insertions(+), 9 deletitions(-)

diff --git a/plugins/imjournal/imjournal.c b/plugins/imjournal/imjournal.c

index 5739bf408c..6c8829243a 100644

--- a/plugins/imjournal/imjournal.c

+++ b/plugins/imjournal/imjournal.c

@@ -24,6 +24,7 @@

 #include "config.h"

 #include "rsyslog.h"

 #include <stdio.h>

+#include <dirent.h>

 #include <assert.h>

 #include <string.h>

 #include <stdarg.h>

@@ -81,6 +82,7 @@ static struct configSettings_s {

 	int bUseJnlPID;

 	char *dfltTag;

 	int bWorkAroundJournalBug;

+	int bFsync;

 } cs;

 static rsRetVal facilityHdlr(uchar **pp, void *pVal);

@@ -99,7 +99,8 @@ static struct cnfparamdescr modpdescr[] = {

 	{ "defaultfacility", eCmdHdlrString, 0 },

 	{ "usepidfromsystem", eCmdHdlrBinary, 0 },

 	{ "defaulttag", eCmdHdlrGetWord, 0 },

-	{ "workaroundjournalbug", eCmdHdlrBinary, 0 }

+	{ "workaroundjournalbug", eCmdHdlrBinary, 0 },

+	{ "fsync", eCmdHdlrBinary, 0 }

 };

 static struct cnfparamblk modpblk =

 	{ CNFPARAMBLK_VERSION,

@@ -437,7 +437,7 @@ persistJournalState(int trySave)

 persistJournalState(int trySave)

 {

 	DEFiRet;

-	FILE *sf; /* state file */

+	FILE *sf = NULL; /* state file */

 	char tmp_sf[MAXFNAME];

 	int ret = 0;

@@ -468,13 +468,6 @@ persistJournalState(int trySave)

 	ret = fputs(last_cursor, sf);

 	if (ret < 0) {

 		errmsg.LogError(errno, RS_RET_IO_ERROR, "imjournal: failed to save cursor to: '%s'", tmp_sf);

-		ret = fclose(sf);

-		ABORT_FINALIZE(RS_RET_IO_ERROR);

-	}

-

-	ret = fclose(sf);

-	if (ret < 0) {

-		errmsg.LogError(errno, RS_RET_IO_ERROR, "imjournal: fclose() failed for path: '%s'", tmp_sf);

 		ABORT_FINALIZE(RS_RET_IO_ERROR);

 	}

@@ -484,7 +477,30 @@ persistJournalState(int trySave)

 		ABORT_FINALIZE(RS_RET_IO_ERROR);

 	}

+	if (cs.bFsync) {

+		if (fsync(fileno(sf)) != 0) {

+			LogError(errno, RS_RET_IO_ERROR, "imjournal: fsync on '%s' failed", cs.stateFile);

+			ABORT_FINALIZE(RS_RET_IO_ERROR);

+		}

+		/* In order to guarantee physical write we need to force parent sync as well */

+		DIR *wd;

+		if (!(wd = opendir((char *)glbl.GetWorkDir()))) {

+			LogError(errno, RS_RET_IO_ERROR, "imjournal: failed to open '%s' directory", glbl.GetWorkDir());

+			ABORT_FINALIZE(RS_RET_IO_ERROR);

+		}

+		if (fsync(dirfd(wd)) != 0) {

+			LogError(errno, RS_RET_IO_ERROR, "imjournal: fsync on '%s' failed", glbl.GetWorkDir());

+			ABORT_FINALIZE(RS_RET_IO_ERROR);

+		}

+	}

+

 finalize_it:

+	if (sf != NULL) {

+		if (fclose(sf) == EOF) {

+			LogError(errno, RS_RET_IO_ERROR, "imjournal: fclose() failed for path: '%s'", tmp_sf);

+			iRet = RS_RET_IO_ERROR;

+		}

+	}

 	RETiRet;

 }

@@ -746,6 +747,8 @@ CODESTARTbeginCnfLoad

 	cs.iDfltFacility = DFLT_FACILITY;

 	cs.dfltTag = NULL;

 	cs.bUseJnlPID = 0;

+	cs.bWorkAroundJournalBug = 0;

+	cs.bFsync = 0;

 ENDbeginCnfLoad

@@ -943,6 +963,8 @@ CODESTARTsetModCnf

 			cs.dfltTag = (char *)es_str2cstr(pvals[i].val.d.estr, NULL);

 		} else if (!strcmp(modpblk.descr[i].name, "workaroundjournalbug")) {

 			cs.bWorkAroundJournalBug = (int) pvals[i].val.d.n;

+		} else if (!strcmp(modpblk.descr[i].name, "fsync")) {

+			cs.bFsync = (int) pvals[i].val.d.n;

 		} else {

 			dbgprintf("imjournal: program error, non-handled "

 				"param '%s' in beginCnfLoad\n", modpblk.descr[i].name);