TCXB7-7251: Fix marker loss on in-place log truncation

source/dcautil/dca.c

@@ -1055,6 +1055,9 @@ static FileDescriptor* getFileDeltaInMemMapAndSearch(const int fd, const off_t s
     off_t offset_in_page_size_multiple ;
     unsigned int bytes_ignored = 0, bytes_ignored_main = 0, bytes_ignored_rotated = 0;
     off_t main_fsize = 0, rotated_fsize = 0;
+    // Log upload backs up and truncates in place, so the stored seek no longer refers
+    // to any data still present in this file.
+    const bool truncated = (seek_value > sb.st_size);
     // Find the nearest multiple of page size
     if (seek_value > 0 && PAGESIZE > 0)
     {
@@ -1186,9 +1189,19 @@ static FileDescriptor* getFileDeltaInMemMapAndSearch(const int fd, const off_t s
                 // No inode change (seek_value > sb.st_size or check_rotated path)
                 // Legacy behavior: read entire rotated + current from seek
                 rotated_fsize = rb.st_size;
-                main_fsize = sb.st_size - seek_value;
-                bytes_ignored_main = bytes_ignored;
-                addrcf = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, tmp_fd, offset_in_page_size_multiple);
+                if(truncated)
+                {
+                    // Stale seek points past the truncated file - read all of it
+                    main_fsize = sb.st_size;
+                    bytes_ignored_main = 0;
+                    addrcf = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, tmp_fd, 0);
+                }
+                else
+                {
+                    main_fsize = sb.st_size - seek_value;
+                    bytes_ignored_main = bytes_ignored;
+                    addrcf = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, tmp_fd, offset_in_page_size_multiple);
+                }
                 addrrf = mmap(NULL, rb.st_size, PROT_READ, MAP_PRIVATE, tmp_rd, 0);
             }
             if(tmp_rd != -1)
@@ -1216,6 +1229,16 @@ static FileDescriptor* getFileDeltaInMemMapAndSearch(const int fd, const off_t s
                 bytes_ignored_main = bytes_ignored;
                 main_fsize = sb.st_size - seek_value;
             }
+            else if(truncated)
+            {
+                // Truncated in place with no rotated file to fall back on - read the
+                // entire current file so its markers are still collected this cycle
+                T2Info("Log file %s truncated (seek %jd > size %jd), reading entire current file\n",
+                       logFile, (intmax_t)seek_value, (intmax_t)sb.st_size);
+                addrcf = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, tmp_fd, 0);
+                bytes_ignored_main = 0;
+                main_fsize = sb.st_size;
+            }
             else
             {
 

source/test/dcautils/dcautilTest.cpp

@@ -1771,6 +1771,91 @@ TEST_F(dcaTestFixture, getDCAResultsInVector_MultiRotation_IntermediateFile)
     Vector_Destroy(vecMarkerList, freeGMarker);
 }
 
+// TCXB7-7251: PARODUSlog.txt truncated in place by log upload with no rotated
+// backup available - stale seek must not cause the marker to be dropped.
+TEST_F(dcaTestFixture, getDCAResultsInVector_TruncatedInPlace_NoRotatedFile)
+{
+    GrepSeekProfile *gsProfile = (GrepSeekProfile *)malloc(sizeof(GrepSeekProfile));
+    gsProfile->logFileSeekMap = hash_map_create();
+    gsProfile->execCounter = 2;
+    long *tempnum;
+    double val = 5000;
+    tempnum = (long *)malloc(sizeof(long));
+    *tempnum = (long)val;
+    hash_map_put(gsProfile->logFileSeekMap, strdup("PARODUSlog.txt"), (void*)tempnum, free);
+
+    Vector* vecMarkerList = NULL;
+    Vector_Create(&vecMarkerList);
+    GrepMarker* marker = (GrepMarker*) malloc(sizeof(GrepMarker));
+    memset(marker, 0, sizeof(GrepMarker));
+    marker->markerName = strdup("SYS_INFO_LowQosEvntUpload");
+    marker->searchString = strdup("PARODUS: Low qos event");
+    marker->trimParam = true;
+    marker->regexParam = strdup("[0-9]+");
+    marker->logFile = strdup("PARODUSlog.txt");
+    marker->skipFreq = 0;
+    marker->paramType = strdup("grep");
+    marker->mType = MTYPE_COUNTER;
+    marker->u.count = 0;
+    marker->reportEmptyParam = true;
+    Vector_PushBack(vecMarkerList, (void*) marker);
+
+    //freeFileDescriptor
+    EXPECT_CALL(*g_fileIOMock, munmap(_, _))
+            .Times(1)
+            .WillOnce(Return(0));
+    EXPECT_CALL(*g_fileIOMock, close(_))
+            .Times(2)
+            .WillOnce(Return(0))
+            .WillOnce(Return(0));
+
+    //getLogFileDescriptor opens the current (truncated) file, then
+    //getRotatedLogFileDescriptor fails to open the missing .1 file
+    EXPECT_CALL(*g_fileIOMock, open(_,_))
+            .Times(2)
+            .WillOnce(Return(0))
+            .WillOnce(Return(-1));
+    EXPECT_CALL(*g_fileIOMock, fstat(_, _))
+        .Times(2)
+        .WillOnce([](int fd, struct stat* statbuf) {
+        statbuf->st_size = 800;      // Truncated file size, smaller than stored seek 5000
+        return 0;
+    })
+        .WillOnce([](int fd, struct stat* statbuf) {
+        statbuf->st_size = 800;
+        return 0;
+    });
+
+    //getDeltainmmapsearch - only the current file is staged, no rotated tmp file
+    EXPECT_CALL(*g_fileIOMock, mkstemp(_))
+            .Times(1)
+            .WillOnce(Return(0));
+    EXPECT_CALL(*g_systemMock, unlink(_))
+                .Times(1)
+                .WillOnce(Return(0));
+    EXPECT_CALL(*g_fileIOMock,sendfile(_,_,_,_))
+            .Times(1)
+            .WillOnce(Return(800));
+    EXPECT_CALL(*g_fileIOMock, mmap(_,_,_,_,_,_))
+                .Times(1)
+                .WillOnce([](void *addr, size_t length, int prot, int flags, int fd, off_t offset) {
+                    EXPECT_EQ(0, offset); // Entire current file read from offset 0 despite stale seek
+                    const char* test_str = "PARODUS: Low qos event, send success callback and delete\n";
+                    char* mapped_mem = (char*)malloc(length);
+                    memset(mapped_mem, 0, length);
+                    strncpy(mapped_mem, test_str, length - 1);
+                    return (void*)mapped_mem;
+                });
+
+    EXPECT_EQ(0, getDCAResultsInVector(gsProfile, vecMarkerList, false, "/opt/logs"));
+    EXPECT_EQ(1, marker->u.count); // Marker must still be captured despite the truncation
+
+    hash_map_destroy(gsProfile->logFileSeekMap, free);
+    gsProfile->logFileSeekMap = NULL;
+    free(gsProfile);
+    Vector_Destroy(vecMarkerList, freeGMarker);
+}
+
 TEST_F(dcaTestFixture, T2InitProperties)
 {
    EXPECT_CALL(*g_fileIOMock, fopen(_,_))