Merge lp:~gaul/percona-data-recovery-tool-for-innodb/calculate-new-checksum-first into lp:percona-data-recovery-tool-for-innodb

[Andrew Gaul]

[Aleksandr Kuzminsky (akuzminsky)]

review: Approve

=== modified file 'include/innochecksum.h'
--- include/innochecksum.h	2010-09-21 07:54:13 +0000
+++ include/innochecksum.h	2012-08-02 22:57:21 +0000
@@ -134,6 +134,14 @@
     return(checksum);
 }
 
+/********************************************************************//**
+In versions < 4.0.14 and < 4.1.1 there was a bug that the checksum only
+looked at the first few bytes of the page. This calculates that old
+checksum.
+NOTE: we must first store the new formula checksum to
+FIL_PAGE_SPACE_OR_CHKSUM before calculating and storing this old checksum
+because this takes that field as an input!
+@return checksum */
 ulint
 buf_calc_page_old_checksum(
 /*=======================*/

=== modified file 'innochecksum.c'
--- innochecksum.c	2010-09-21 07:54:13 +0000
+++ innochecksum.c	2012-08-02 22:57:21 +0000
@@ -208,6 +208,35 @@
       	}
     }
 
+    /* now check the new method */
+    csum= buf_calc_page_new_checksum(p);
+    csumfield= mach_read_from_4(p + FIL_PAGE_SPACE_OR_CHKSUM);
+    if (debug)
+      printf("page %lu: new style: calculated = %lu; recorded = %lu\n", ct, csum, csumfield);
+    if (csumfield != 0 && csum != csumfield)
+    {
+      fprintf(stderr, "page %lu invalid (fails new style checksum)\n", ct);
+      fprintf(stderr, "page %lu: new style: calculated = 0x%X; recorded = 0x%X\n", ct, csum, csumfield);
+      if(fix_checksum){
+      	fprintf(stderr, "fixing new checksum of page %lu\n", ct);
+	// rewite recorded checksum with calculated one
+	fixed_chksum = mach_read_from_4((uchar*)&csum);
+	memcpy(p + FIL_PAGE_SPACE_OR_CHKSUM, &fixed_chksum, sizeof(fixed_chksum));
+	// move to beginning of the page
+	if(0 != fsetpos(f, &pos)){
+      		perror("couldn't set a position to the start of the page");
+		return 1;
+		}
+	if(1 != fwrite(p, UNIV_PAGE_SIZE, 1, f)){
+      		perror("couldn't update the page");
+		return 1;
+		}
+      	}
+      else{
+      	return 1;
+      	}
+    }
+
     /* check old method of checksumming */
     oldcsum= buf_calc_page_old_checksum(p);
     oldcsumfield= mach_read_from_4(p + UNIV_PAGE_SIZE - FIL_PAGE_END_LSN_OLD_CHKSUM);
@@ -238,35 +267,6 @@
       	}
     }
 
-    /* now check the new method */
-    csum= buf_calc_page_new_checksum(p);
-    csumfield= mach_read_from_4(p + FIL_PAGE_SPACE_OR_CHKSUM);
-    if (debug)
-      printf("page %lu: new style: calculated = %lu; recorded = %lu\n", ct, csum, csumfield);
-    if (csumfield != 0 && csum != csumfield)
-    {
-      fprintf(stderr, "page %lu invalid (fails new style checksum)\n", ct);
-      fprintf(stderr, "page %lu: new style: calculated = 0x%X; recorded = 0x%X\n", ct, csum, csumfield);
-      if(fix_checksum){
-      	fprintf(stderr, "fixing new checksum of page %lu\n", ct);
-	// rewite recorded checksum with calculated one
-	fixed_chksum = mach_read_from_4((uchar*)&csum);
-	memcpy(p + FIL_PAGE_SPACE_OR_CHKSUM, &fixed_chksum, sizeof(fixed_chksum));
-	// move to beginning of the page
-	if(0 != fsetpos(f, &pos)){
-      		perror("couldn't set a position to the start of the page");
-		return 1;
-		}
-	if(1 != fwrite(p, UNIV_PAGE_SIZE, 1, f)){
-      		perror("couldn't update the page");
-		return 1;
-		}
-      	}
-      else{
-      	return 1;
-      	}
-    }
-
     /* end if this was the last page we were supposed to check */
     if (use_end_page && (ct >= end_page))
       return 0;