Add an option to allow disk syncing to be turned off

Bug: 27795746

Change-Id: I47447a8467c409db526483ac7e4a9394cd68578a
(cherry picked from commit fd9b918d2e49de4b7b7568aaa39f7e179752766d)
(cherry picked from commit 2c2deeb032f6c158cf4f782e1765a4a21af88cb3)

3 files changed, 13 insertions, 2 deletions

diff --git a/gpt.cc b/gpt.cc
index 18247c5..91fa18f 100644
--- a/gpt.cc
+++ b/gpt.cc
@@ -69,6 +69,7 @@ GPTData::GPTData(void) {
    state = gpt_valid;
    device = "";
    justLooking = 0;
+   syncing = 1;
    mainCrcOk = 0;
    secondCrcOk = 0;
    mainPartsCrcOk = 0;
@@ -93,6 +94,7 @@ GPTData::GPTData(string filename) {
    state = gpt_invalid;
    device = "";
    justLooking = 0;
+   syncing = 1;
    mainCrcOk = 0;
    secondCrcOk = 0;
    mainPartsCrcOk = 0;
@@ -128,6 +130,7 @@ GPTData & GPTData::operator=(const GPTData & orig) {
    diskSize = orig.diskSize;
    state = orig.state;
    justLooking = orig.justLooking;
+   syncing = orig.syncing;
    mainCrcOk = orig.mainCrcOk;
    secondCrcOk = orig.secondCrcOk;
    mainPartsCrcOk = orig.mainPartsCrcOk;
@@ -1142,7 +1145,7 @@ int GPTData::SaveGPTData(int quiet) {
          // original partition table from its cache. OTOH, such restoration might be
          // desirable if the error occurs later; but that seems unlikely unless the initial
          // write fails....
-         if (syncIt)
+         if (syncIt && syncing)
             myDisk.DiskSync();
 
          if (allOK) { // writes completed OK
@@ -1374,7 +1377,9 @@ int GPTData::DestroyGPT(void) {
             allOK = 0;
          } // if
       } // if
-      myDisk.DiskSync();
+      if (syncing) {
+         myDisk.DiskSync();
+      }
       myDisk.Close();
       cout << "GPT data structures destroyed! You may now partition the disk using fdisk or\n"
            << "other utilities.\n";
diff --git a/gpt.h b/gpt.h
index e9afd06..1c0eaaf 100644
--- a/gpt.h
+++ b/gpt.h
@@ -72,6 +72,7 @@ protected:
    uint64_t diskSize; // size of device, in blocks
    GPTValidity state; // is GPT valid?
    int justLooking; // Set to 1 if program launched with "-l" or if read-only
+   bool syncing; // Set to true if we should sync and reload the partition table
    int mainCrcOk;
    int secondCrcOk;
    int mainPartsCrcOk;
@@ -189,6 +190,7 @@ public:
    uint32_t ComputeAlignment(void); // Set alignment based on current partitions
    uint32_t GetAlignment(void) {return sectorAlignment;}
    void JustLooking(int i = 1) {justLooking = i;}
+   void TurnOffSyncing() {syncing = 0;}
    void BeQuiet(int i = 1) {beQuiet = i;}
    WhichToUse WhichWasUsed(void) {return whichWasUsed;}
 
diff --git a/gptcl.cc b/gptcl.cc
index e20048e..602be5c 100644
--- a/gptcl.cc
+++ b/gptcl.cc
@@ -86,6 +86,7 @@ int GPTDataCL::DoOptions(int argc, char* argv[]) {
       {"randomize-guids", 'G', POPT_ARG_NONE, NULL, 'G', "randomize disk and partition GUIDs", ""},
       {"hybrid", 'h', POPT_ARG_STRING, &hybrids, 'h', "create hybrid MBR", "partnum[:partnum...]"},
       {"info", 'i', POPT_ARG_INT, &infoPartNum, 'i', "show detailed information on partition", "partnum"},
+      {"skip-sync", 'j', POPT_ARG_NONE, NULL, 'j', "Don't atempt to sync and update the parittion table", ""},
       {"load-backup", 'l', POPT_ARG_STRING, &backupFile, 'l', "load GPT backup from file", "file"},
       {"list-types", 'L', POPT_ARG_NONE, NULL, 'L', "list known partition types", ""},
       {"gpttombr", 'm', POPT_ARG_STRING, &mbrParts, 'm', "convert GPT to MBR", "partnum[:partnum...]"},
@@ -260,6 +261,9 @@ int GPTDataCL::DoOptions(int argc, char* argv[]) {
                case 'i':
                   ShowPartDetails(infoPartNum - 1);
                   break;
+               case 'j':
+                  TurnOffSyncing();
+                  break;
                case 'l':
                   LoadBackupFile(backupFile, saveData, neverSaveData);
                   free(backupFile);