From 505acceba17a4987fb445cce1eed792cf41e93c6 Mon Sep 17 00:00:00 2001
From: root <root@avtech.domain.avtechpulse.com>
Date: Thu, 1 Jan 1970 09:33:41 +0900
Subject: add mutex around remounting, and add debug messages

---
 device-functions.c | 12 ++++++++----
 flash.c            | 41 +++++++++++++++++++++++++----------------
 flash.h            |  3 +--
 3 files changed, 34 insertions(+), 22 deletions(-)

diff --git a/device-functions.c b/device-functions.c
index 20918a8..8bca0d7 100644
--- a/device-functions.c
+++ b/device-functions.c
@@ -4402,7 +4402,8 @@ void Main_update_shift_registers()
 
 int IO_Setup_RS232(int baud, char hardhand)
 {
-	remount_root_as_writeable ();
+	printf ("start writeable: rs232 change\n");
+	remount_root_as_writeable (TRUE);
 	FILE* configfile = fopen("/tmp/instgettyopts", "w");
 	if(configfile) {
 		fprintf(configfile, "OPTS=-L %s\n", hardhand ? "-h" : "");
@@ -4410,7 +4411,8 @@ int IO_Setup_RS232(int baud, char hardhand)
 		fclose(configfile);
 		system("systemctl --no-block restart inst-getty@ttyO5.service");
 	}
-	remount_root_as_not_writeable();
+	printf ("end writeable: rs232 change\n");
+	remount_root_as_writeable (FALSE);
 
 	globals.Flash.baud = baud;
 	globals.Flash.hardhand = hardhand;
@@ -4497,7 +4499,8 @@ int change_password(gchar *old_password, gchar *new_password)
 		int result;
 		result = OK;
 
-		remount_root_as_writeable ();
+		printf ("start writeable: password change\n");
+		remount_root_as_writeable (TRUE);
 
 		ctx = lu_start(user, lu_user, NULL, NULL, lu_prompt_console_quiet, NULL, &error);
 
@@ -4517,7 +4520,8 @@ int change_password(gchar *old_password, gchar *new_password)
 
 		lu_end(ctx);
 
-		remount_root_as_not_writeable ();
+		printf ("end writeable: password change\n");
+		remount_root_as_writeable (FALSE);
 
 		return result;
 	} else {
diff --git a/flash.c b/flash.c
index 38f42a2..ab5ebb2 100644
--- a/flash.c
+++ b/flash.c
@@ -308,23 +308,26 @@ hdrlengthok:
 }
 
 
-void remount_root_as_writeable ()
+void remount_root_as_writeable (gboolean start)
 {
 	gchar *cmd;
-	cmd = g_strdup_printf ("/usr/bin/mount -o remount,rw %s /", globals.HWDetect.remount_point);
-	printf ("%s\n",cmd);
-	system(cmd);
-	g_free (cmd);
-}
 
+	static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
+
+	if (start) {
+		g_static_mutex_lock (&mutex);
+		cmd = g_strdup_printf ("/usr/bin/mount -o remount,rw %s /", globals.HWDetect.remount_point);
+	} else {
+		cmd = g_strdup_printf ("/usr/bin/mount -o remount,ro %s /", globals.HWDetect.remount_point);
+	}
 
-void remount_root_as_not_writeable ()
-{
-	gchar *cmd;
-	cmd = g_strdup_printf ("/usr/bin/mount -o remount,ro %s /", globals.HWDetect.remount_point);
 	printf ("%s\n",cmd);
 	system(cmd);
 	g_free (cmd);
+
+	if (!start) {
+		g_static_mutex_unlock (&mutex);
+	}
 }
 
 
@@ -350,12 +353,14 @@ static int readUserBlock(FlashStruct *mem)
 			// if the backup was good overwrite the main file
 			if (!globals.Sys.shutdown_started) {
 				globals.Sys.flash_write_in_progress = TRUE;
-				remount_root_as_writeable ();
+				printf ("start writeable: copy from backup\n");
+				remount_root_as_writeable (TRUE);
 
 				persistence_copyfile(BACKUPFILE, MAINFILE);
 
 				globals.Sys.flash_write_in_progress = FALSE;
-				remount_root_as_not_writeable ();
+				printf ("end writeable: copy from backup\n");
+				remount_root_as_writeable (FALSE);
 			}
 			return sizeof(*mem);
 		}
@@ -384,17 +389,20 @@ void writeUserBlockNow(FlashStruct *mem, int addr, int numbytes)
 		if (!globals.Sys.shutdown_started) {
 
 			globals.Sys.flash_write_in_progress = TRUE;
-			remount_root_as_writeable ();
+			printf ("start writeable: make backup\n");
+			remount_root_as_writeable (TRUE);
 
 			bool backup_ok = persistence_copyfile(MAINFILE, BACKUPFILE);
 
 			globals.Sys.flash_write_in_progress = FALSE;
-			remount_root_as_not_writeable ();
+			printf ("end writeable: make backup\n");
+			remount_root_as_writeable (FALSE);
 
 			if (backup_ok && !globals.Sys.shutdown_started) {
 
 				globals.Sys.flash_write_in_progress = TRUE;
-				remount_root_as_writeable ();
+				printf ("start writeable: write to main config file\n");
+				remount_root_as_writeable (TRUE);
 
 				if (!persistence_freeze(MAINFILE, mem, addr, numbytes, sizeof(*mem), 0)) {
 					if (errno != PERSIST_ERR_COULDNTWRITE) {
@@ -404,7 +412,8 @@ void writeUserBlockNow(FlashStruct *mem, int addr, int numbytes)
 					}
 				}
 				globals.Sys.flash_write_in_progress = FALSE;
-				remount_root_as_not_writeable ();
+				printf ("end writeable: write to main config file\n");
+				remount_root_as_writeable (FALSE);
 			} else {
 				printf("Could not backup current file. **Write did not happen!!!**\n");
 			}
diff --git a/flash.h b/flash.h
index 3627275..d851182 100644
--- a/flash.h
+++ b/flash.h
@@ -8,8 +8,7 @@ void initFlash(FlashStruct *mem, gboolean reset_to_defaults, int starting_locati
 void writeUserBlock(FlashStruct *mem, int addr, int numbytes);
 void fixFlash(FlashStruct *mem);
 void stopFlashWriterThread();
-void remount_root_as_writeable();
-void remount_root_as_not_writeable();
+void remount_root_as_writeable(gboolean start);
 
 #endif
 
-- 
cgit