Merge lp:~gl-az/percona-server/5.1-lru_dump_load_work into lp:percona-server/5.1

[George Ormond Lorch III]

- Launchpad Bug #686392 : Buffer pool dump may result in incomplete dump file.
  - Implemented simple temp file on save and rename to real file on successful dump.
  - Carried over one or two dump file sanity checks from Alexey K prior work.
- Launchpad Bug #712055 : Loading LRU dump prevents shutdown
    - Merged patch noted in bug and also implemented same logic when shutdown comes while performing actual dump. Was able to test and verify its effectiveness with a 1G buffer pool and innodb_auto_lru_dump.
    - Tried to create a test case for this issue but I don't think a proper 'success' case can be built due to the need for a sizable, existing ib_lru_dump file and the natural race conditions ump/that this works with (there is no guarantee that the preload won't finish before the shutdown signal comes).
- Launchpad Bug #713481 : Clean up messaging for LRU dump
    - It appears that PS 5.1 already has begin/end messages for lru restore. Added some verbage to the missing file message to make it not so scary.

Jenkins results at: http://jenkins.percona.com/view/Percona%20Server%205.1/job/percona-server-5.1-param/320/

I am unsure about the failures but they _look_ like Jenkins issues..

[Alexey Kopytov (akopytov)]

OK to merge, but please duplicate the MP description in the revision comment.

review: Approve

=== modified file 'Percona-Server/storage/innodb_plugin/buf/buf0lru.c'
--- Percona-Server/storage/innodb_plugin/buf/buf0lru.c	2011-11-24 16:33:30 +0000
+++ Percona-Server/storage/innodb_plugin/buf/buf0lru.c	2012-05-17 17:56:20 +0000
@@ -48,6 +48,7 @@
 #include "page0zip.h"
 #include "log0recv.h"
 #include "srv0srv.h"
+#include "srv0start.h"
 
 /** The number of blocks from the LRU_old pointer onward, including
 the block pointed to, must be buf_LRU_old_ratio/BUF_LRU_OLD_RATIO_DIV
@@ -2098,6 +2099,7 @@
 /********************************************************************//**
 Dump the LRU page list to the specific file. */
 #define LRU_DUMP_FILE "ib_lru_dump"
+#define LRU_DUMP_TEMP_FILE "ib_lru_dump.tmp"
 
 UNIV_INTERN
 ibool
@@ -2132,7 +2134,7 @@
 		goto end;
 	}
 
-	dump_file = os_file_create(LRU_DUMP_FILE, OS_FILE_OVERWRITE,
+	dump_file = os_file_create(LRU_DUMP_TEMP_FILE, OS_FILE_OVERWRITE,
 				OS_FILE_NORMAL, OS_DATA_FILE, &success);
 	if (!success) {
 		os_file_get_last_error(TRUE);
@@ -2156,6 +2158,13 @@
 		offset++;
 
 		if (offset == UNIV_PAGE_SIZE/4) {
+			if (srv_shutdown_state != SRV_SHUTDOWN_NONE) {
+				success = 0;
+				fprintf(stderr,
+					" InnoDB: stopped dumping lru pages"
+					" because of server shutdown.\n");
+				goto end;
+			}
 			success = os_file_write(LRU_DUMP_FILE, dump_file, buffer,
 					(buffers << UNIV_PAGE_SIZE_SHIFT) & 0xFFFFFFFFUL,
 					(buffers >> (32 - UNIV_PAGE_SIZE_SHIFT)),
@@ -2194,8 +2203,16 @@
 
 	ret = TRUE;
 end:
-	if (dump_file != -1)
+	if (dump_file != -1) {
+		if (success) {
+			success = os_file_flush(dump_file, TRUE);
+		}
 		os_file_close(dump_file);
+	}
+	if (success) {
+		success = os_file_rename(LRU_DUMP_TEMP_FILE,
+			LRU_DUMP_FILE);
+	}
 	if (buffer_base)
 		ut_free(buffer_base);
 
@@ -2241,6 +2258,7 @@
 	dump_record_t*	records = NULL;
 	ulint		size;
 	ulint		size_high;
+	ulint 		recsize = sizeof(dump_record_t);
 	ulint		length;
 
 	dump_file = os_file_create_simple_no_error_handling(
@@ -2248,7 +2266,15 @@
 	if (!success || !os_file_get_size(dump_file, &size, &size_high)) {
 		os_file_get_last_error(TRUE);
 		fprintf(stderr,
-			" InnoDB: cannot open %s\n", LRU_DUMP_FILE);
+			" InnoDB: cannot open %s,"
+			" buffer pool preload not done\n",
+			LRU_DUMP_FILE);
+		goto end;
+	}
+
+	if (size == 0 || size_high > 0 || size % recsize) {
+		fprintf(stderr, " InnoDB: broken LRU dump file,"
+			" buffer pool preload not done\n");
 		goto end;
 	}
 
@@ -2332,6 +2358,14 @@
 		if (offset % 16 == 15) {
 			os_aio_simulated_wake_handler_threads();
 			buf_flush_free_margin(FALSE);
+			/* skip loading of the rest of the file if we are
+ 			   terminating anyway*/
+			if (srv_shutdown_state != SRV_SHUTDOWN_NONE) {
+				fprintf(stderr,
+					" InnoDB: stopped loading LRU pages"
+					" because of server shutdown.\n");
+				break;
+			}
 		}
 
 		zip_size = fil_space_get_zip_size(space_id);