fix [t:2426], add test

git-svn-id: file:///svn/toku/tokudb@18290 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/logcursor.c

@@ -169,6 +169,8 @@ static int lc_create(TOKULOGCURSOR *lc, const char *log_dir) {
     return failresult;
 }
 
+static int lc_scan_from_beginning_of_file_to_find_last(TOKULOGCURSOR lc);
+
 int toku_logcursor_create(TOKULOGCURSOR *lc, const char *log_dir) {
     TOKULOGCURSOR cursor;
     int r = lc_create(&cursor, log_dir);
@@ -394,12 +396,22 @@ int toku_logcursor_last(TOKULOGCURSOR lc, struct log_entry **le) {
     }
     while (1) {
         // seek to end
-        r = fseek(lc->cur_fp, 0, SEEK_END);
-        assert(0==r);
+        r = fseek(lc->cur_fp, 0, SEEK_END);    assert(r==0);
         // read backward
         r = toku_log_fread_backward(lc->cur_fp, &(lc->entry));
-        if (r==0) 
+        if (r==0) // got a good entry
             break;
+        if (r>0) { 
+            // got an error, 
+            // probably a corrupted last log entry due to a crash
+            // try scanning forward from the beginning to find the last good entry
+            r = lc_scan_from_beginning_of_file_to_find_last(lc);
+            assert(r==0);
+            // try reading again
+            r = toku_log_fread_backward(lc->cur_fp, &(lc->entry));
+            if (r==0) // got a good entry
+                break;
+        }
         // move to previous file
         r = lc_close_cur_logfile(lc);
         if (r!=0) 
@@ -432,3 +444,29 @@ toku_logcursor_log_exists(const TOKULOGCURSOR lc) {
 
     return r;
 }
+
+// return a logcursor with the cur_fp pointing to the end of the last good entry
+static int lc_scan_from_beginning_of_file_to_find_last(TOKULOGCURSOR lc) {
+    struct log_entry le;
+    unsigned int version=0;
+    int r = 0;
+
+    r = fseek(lc->cur_fp, 0, SEEK_SET);                assert(r==0);
+    r = toku_read_logmagic(lc->cur_fp, &version);      assert(r==0);
+    
+    fpos_t last_good_pos;
+    r = fgetpos(lc->cur_fp, &last_good_pos);           assert(r==0);
+    while (1) {
+        if ( lc->entry_valid ) {
+            toku_log_free_log_entry_resources(&le);
+            lc->entry_valid = FALSE;
+        }
+        r = toku_log_fread(lc->cur_fp, &le);
+        if ( r!=0 ) break;
+        r = fgetpos(lc->cur_fp, &last_good_pos);       assert(r==0);
+    }
+    // now have position of last good entry - set cur_fp and return
+    r = fsetpos(lc->cur_fp, &last_good_pos);           assert(r==0);
+    return 0;
+}
+

newbrt/logformat.c

@@ -424,22 +424,23 @@ generate_log_reader (void) {
     fprintf(cf, "  };\n");
     fprintf(cf, "  return DB_BADFORMAT;\n"); // Should read past the record using the len field.
     fprintf(cf, "}\n\n");
-    fprintf2(cf, hf, "// Return 0 if there is something to read, return -1 if nothing to read, abort if an error.\n");
+    //fprintf2(cf, hf, "// Return 0 if there is something to read, return -1 if nothing to read, abort if an error.\n");
+    fprintf2(cf, hf, "// Return 0 if there is something to read, -1 if nothing to read, >0 on error\n");
     fprintf2(cf, hf, "int toku_log_fread_backward (FILE *infile, struct log_entry *le)");
     fprintf(hf, ";\n");
     fprintf(cf, "{\n");
     fprintf(cf, "  {\n    long pos = ftell(infile);\n    if (pos<=12) return -1;\n  }\n");
-    fprintf(cf, "  int r = fseek(infile, -4, SEEK_CUR);              assert(r==0);\n");
-    //fprintf(cf, "  if (r!=0) return errno;\n");
+    fprintf(cf, "  int r = fseek(infile, -4, SEEK_CUR); \n");//              assert(r==0);\n");
+    fprintf(cf, "  if (r!=0) return errno;\n");
     fprintf(cf, "  u_int32_t len;\n");
-    fprintf(cf, "  r = toku_fread_u_int32_t_nocrclen(infile, &len);  assert(r==0);\n");
-    //fprintf(cf, "  if (r!=0) return r;\n");
-    fprintf(cf, "  r = fseek(infile, -(int)len, SEEK_CUR) ;          assert(r==0);\n");
-    //fprintf(cf, "  if (r!=0) return errno;\n");
-    fprintf(cf, "  r = toku_log_fread(infile, le);                   assert(r==0);\n");
-    //fprintf(cf, "  if (r!=0) return r;\n");
-    fprintf(cf, "  r = fseek(infile, -(int)len, SEEK_CUR);           assert(r==0);\n");
-    //fprintf(cf, "  if (r!=0) return errno;\n");
+    fprintf(cf, "  r = toku_fread_u_int32_t_nocrclen(infile, &len); \n");//  assert(r==0);\n");
+    fprintf(cf, "  if (r!=0) return 1;\n");
+    fprintf(cf, "  r = fseek(infile, -(int)len, SEEK_CUR) ;  \n");//         assert(r==0);\n");
+    fprintf(cf, "  if (r!=0) return errno;\n");
+    fprintf(cf, "  r = toku_log_fread(infile, le); \n");//                   assert(r==0);\n");
+    fprintf(cf, "  if (r!=0) return 1;\n");
+    fprintf(cf, "  r = fseek(infile, -(int)len, SEEK_CUR); \n");//           assert(r==0);\n");
+    fprintf(cf, "  if (r!=0) return errno;\n");
     fprintf(cf, "  return 0;\n");
     fprintf(cf, "}\n\n");
 

newbrt/tests/recovery-bad-last-entry.c

+// test recovery of "hello" comments
+
+#include "test.h"
+#include "includes.h"
+
+#define TESTDIR "dir." __FILE__ 
+
+static const int magic_begin_end_checkpoint_sz = 77;  // leave this many bytes in file
+
+static int 
+run_test(void) {
+    int r;
+    int trim = 1;
+    struct stat st;
+
+    while ( 1 ) {
+        // setup the test dir
+        system("rm -rf " TESTDIR);
+        r = toku_os_mkdir(TESTDIR, S_IRWXU); assert(r == 0);
+
+        // create the log
+        TOKULOGGER logger;
+        BYTESTRING hello  = { strlen("hello"), "hello" };
+        BYTESTRING world  = { strlen("world"), "world" };
+        BYTESTRING there  = { strlen("there"), "there" };
+        r = toku_logger_create(&logger); assert(r == 0);
+        r = toku_logger_open(TESTDIR, logger); assert(r == 0);
+        LSN beginlsn;
+        // all logs must contain a valid checkpoint
+        r = toku_log_begin_checkpoint(logger, &beginlsn, TRUE, 0); assert(r == 0);
+        r = toku_log_end_checkpoint(logger, NULL, TRUE, beginlsn.lsn, 0); assert(r == 0);
+
+        r = toku_log_comment(logger, NULL, TRUE, 0, hello); assert(r == 0);
+        r = toku_log_comment(logger, NULL, TRUE, 0, world); assert(r == 0);
+        r = toku_log_begin_checkpoint(logger, &beginlsn, TRUE, 0); assert(r == 0);
+        r = toku_log_end_checkpoint(logger, NULL, TRUE, beginlsn.lsn, 0); assert(r == 0);
+        r = toku_log_comment(logger, NULL, TRUE, 0, hello); assert(r == 0);
+        r = toku_log_comment(logger, NULL, TRUE, 0, there); assert(r == 0);
+        r = toku_logger_close(&logger); assert(r == 0);
+
+        // redirect stderr
+        int devnul = open(DEV_NULL_FILE, O_WRONLY);
+        assert(devnul>=0);
+        r = toku_dup2(devnul, fileno(stderr)); 	    assert(r==fileno(stderr));
+        r = close(devnul);                      assert(r==0);
+
+        char fname[256];
+        sprintf(fname, "%s/%s", TESTDIR, "log000000000000.tokulog");
+
+        r = toku_stat(fname, &st); assert(r==0);
+        if ( st.st_size - trim > magic_begin_end_checkpoint_sz )
+            truncate(fname, st.st_size - trim);
+        else
+            break;
+        // run recovery
+        r = tokudb_recover(TESTDIR, TESTDIR, 0, 0, NULL, NULL, 0); 
+        assert(r == 0);
+        
+        trim += 1;
+    }
+    return 0;
+}
+
+int
+test_main(int UU(argc), const char *UU(argv[])) {
+    int r;
+    r = run_test();
+    return r;
+}