log0recv.c Add checksum to written pages to check that they are also read in unchanged

buf0buf.h	Add checksum to written pages to check that they are also read in unchanged
buf0flu.c	Add checksum to written pages to check that they are also read in unchanged
buf0buf.c	Add checksum to written pages to check that they are also read in unchanged

innobase/buf/buf0buf.c

@@ -204,7 +204,28 @@ ulint		buf_dbg_counter	= 0; /* This is used to insert validation
 ibool		buf_debug_prints = FALSE; /* If this is set TRUE,
 					the program prints info whenever
 					read-ahead or flush occurs */
-					
+
+/************************************************************************
+Calculates a page checksum which is stored to the page when it is written
+to a file. Note that we must be careful to calculate the same value
+on 32-bit and 64-bit architectures. */
+
+ulint
+buf_calc_page_checksum(
+/*===================*/
+		       /* out: checksum */
+	byte*    page) /* in: buffer page */
+{
+  ulint checksum;
+
+  checksum = ut_fold_binary(page, FIL_PAGE_FILE_FLUSH_LSN);
+  + ut_fold_binary(page + FIL_PAGE_DATA, UNIV_PAGE_SIZE - FIL_PAGE_DATA
+		   - FIL_PAGE_END_LSN);
+  checksum = checksum & 0xFFFFFFFF;
+
+  return(checksum);
+}
+
 /************************************************************************
 Initializes a buffer control block when the buf_pool is created. */
 static
@@ -1171,12 +1192,36 @@ buf_page_io_complete(
 	dulint		id;
 	dict_index_t*	index;
 	ulint		io_type;
+	ulint           checksum;
 
 	ut_ad(block);
 
 	io_type = block->io_fix;
 
 	if (io_type == BUF_IO_READ) {
+		checksum = buf_calc_page_checksum(block->frame);
+
+		/* From version 3.23.38 up we store the page checksum
+		   to the 4 upper bytes of the page end lsn field */
+
+		if ((mach_read_from_4(block->frame + FIL_PAGE_LSN + 4)
+		    != mach_read_from_4(block->frame + UNIV_PAGE_SIZE
+					- FIL_PAGE_END_LSN + 4))
+		    || (checksum != mach_read_from_4(block->frame
+                                        + UNIV_PAGE_SIZE
+					- FIL_PAGE_END_LSN)
+			&& mach_read_from_4(block->frame + FIL_PAGE_LSN)
+			    != mach_read_from_4(block->frame
+                                        + UNIV_PAGE_SIZE
+						- FIL_PAGE_END_LSN))) {
+		  fprintf(stderr,
+			  "InnoDB: Database page corruption or a failed\n"
+			  "InnoDB: file read of page %lu.\n", block->offset);
+		  fprintf(stderr,
+			  "InnoDB: You may have to recover from a backup.\n");
+		  exit(1);
+		}
+
 		if (recv_recovery_is_on()) {
 			recv_recover_page(TRUE, block->frame, block->space,
 								block->offset);
@@ -1208,17 +1253,8 @@ buf_page_io_complete(
 		ut_ad(buf_pool->n_pend_reads > 0);
 		buf_pool->n_pend_reads--;
 		buf_pool->n_pages_read++;
-/*		
-		if (0 != ut_dulint_cmp(
-				mach_read_from_8(block->frame + FIL_PAGE_LSN),
-				mach_read_from_8(block->frame + UNIV_PAGE_SIZE
-						- FIL_PAGE_END_LSN))) {
 
-			printf("DB error: file page corrupted!\n");
 
-			ut_error;
-		}
-*/
 		rw_lock_x_unlock_gen(&(block->lock), BUF_IO_READ);
 		rw_lock_x_unlock_gen(&(block->read_lock), BUF_IO_READ);
 

innobase/buf/buf0flu.c

@@ -222,6 +222,12 @@ buf_flush_write_block_low(
 	mach_write_to_8(block->frame + UNIV_PAGE_SIZE - FIL_PAGE_END_LSN,
 						block->newest_modification);
 
+	/* We overwrite the first 4 bytes of the end lsn field to store
+	a page checksum */
+
+	mach_write_to_4(block->frame + UNIV_PAGE_SIZE - FIL_PAGE_END_LSN,
+			buf_calc_page_checksum(block->frame));
+
 	fil_io(OS_FILE_WRITE | OS_AIO_SIMULATED_WAKE_LATER,
 		FALSE, block->space, block->offset, 0, UNIV_PAGE_SIZE,
 		 			(void*)block->frame, (void*)block);

innobase/include/buf0buf.h

@@ -342,6 +342,16 @@ buf_frame_get_modify_clock(
 /*=======================*/
 				/* out: value */
 	buf_frame_t*	frame);	/* in: pointer to a frame */
+/************************************************************************
+Calculates a page checksum which is stored to the page when it is written
+to a file. Note that we must be careful to calculate the same value
+on 32-bit and 64-bit architectures. */
+
+ulint
+buf_calc_page_checksum(
+/*===================*/
+		       /* out: checksum */
+	byte*   page); /* in: buffer page */
 /**************************************************************************
 Gets the page number of a pointer pointing within a buffer frame containing
 a file page. */

innobase/log/log0recv.c

@@ -882,12 +882,6 @@ recv_recover_page(
 		recv = UT_LIST_GET_NEXT(rec_list, recv);
 	}
 
-	/* If the following assert fails, the file page is incompletely
-	written, and a recovery from a backup is required */
-	
-	ut_a(0 == ut_dulint_cmp(mach_read_from_8(page + FIL_PAGE_LSN),
-				mach_read_from_8(page + UNIV_PAGE_SIZE
-							- FIL_PAGE_END_LSN)));
 	mutex_enter(&(recv_sys->mutex));
 	
 	recv_addr->state = RECV_PROCESSED;