~ignacio-nin/percona-server/5.1-issue26684

# name       : sql_no_fcache.patch
# introduced : 12
# maintainer : Oleg
#
#!!! notice !!!
# Any small change to this file in the main branch
# should be done or reviewed by the maintainer!
diff -ruN a/client/mysqldump.c b/client/mysqldump.c
--- a/client/mysqldump.c	2010-07-28 16:47:58.264067653 +0400
+++ b/client/mysqldump.c	2010-07-28 16:47:59.604985656 +0400
@@ -132,6 +132,8 @@
 #endif
 static uint opt_protocol= 0;
 
+static my_bool server_supports_sql_no_fcache= FALSE;
+
 /*
 Dynamic_string wrapper functions. In this file use these
 wrappers, they will terminate the process if there is
@@ -1512,6 +1514,17 @@
     /* Don't switch charsets for 4.1 and earlier.  (bug#34192). */
     server_supports_switching_charsets= FALSE;
   } 
+  
+  /* Check to see if we support SQL_NO_FCACHE on this server. */ 
+  if (mysql_query(mysql, "SELECT SQL_NO_FCACHE NOW()") == 0)
+  {
+    MYSQL_RES *res = mysql_store_result(mysql);
+    if (res)
+    {
+      mysql_free_result(res);
+    }
+    server_supports_sql_no_fcache= TRUE;
+  }
   /*
     As we're going to set SQL_MODE, it would be lost on reconnect, so we
     cannot reconnect.
@@ -3175,7 +3188,12 @@
 
     /* now build the query string */
 
-    dynstr_append_checked(&query_string, "SELECT /*!40001 SQL_NO_CACHE */ * INTO OUTFILE '");
+    dynstr_append_checked(&query_string, "SELECT /*!40001 SQL_NO_CACHE */ ");
+    if (server_supports_sql_no_fcache)
+    {
+      dynstr_append_checked(&query_string, "/*!50084 SQL_NO_FCACHE */ ");
+    }
+    dynstr_append_checked(&query_string, "* INTO OUTFILE '");
     dynstr_append_checked(&query_string, filename);
     dynstr_append_checked(&query_string, "'");
 
@@ -3225,7 +3243,12 @@
       check_io(md_result_file);
     }
     
-    dynstr_append_checked(&query_string, "SELECT /*!40001 SQL_NO_CACHE */ * FROM ");
+    dynstr_append_checked(&query_string, "SELECT /*!40001 SQL_NO_CACHE */ ");
+    if (server_supports_sql_no_fcache)
+    {
+      dynstr_append_checked(&query_string, "/*!50084 SQL_NO_FCACHE */ ");
+    }
+    dynstr_append_checked(&query_string, "* FROM ");
     dynstr_append_checked(&query_string, result_table);
 
     if (where)
diff -ruN a/include/flashcache_ioctl.h b/include/flashcache_ioctl.h
--- a/include/flashcache_ioctl.h	1970-01-01 03:00:00.000000000 +0300
+++ b/include/flashcache_ioctl.h	2010-07-28 16:47:59.744079911 +0400
@@ -0,0 +1,53 @@
+/****************************************************************************
+ *  flashcache_ioctl.h
+ *  FlashCache: Device mapper target for block-level disk caching
+ *
+ *  Copyright 2010 Facebook, Inc.
+ *  Author: Mohan Srinivasan (mohan@facebook.com)
+ *
+ *  Based on DM-Cache:
+ *   Copyright (C) International Business Machines Corp., 2006
+ *   Author: Ming Zhao (mingzhao@ufl.edu)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ ****************************************************************************/
+
+#ifndef FLASHCACHE_IOCTL_H
+#define FLASHCACHE_IOCTL_H
+
+#include <linux/types.h>
+
+#define FLASHCACHE_IOCTL 0xfe
+
+enum {
+       FLASHCACHEADDNCPID_CMD=200,
+       FLASHCACHEDELNCPID_CMD,
+       FLASHCACHEDELNCALL_CMD,
+       FLASHCACHEADDWHITELIST_CMD,
+       FLASHCACHEDELWHITELIST_CMD,
+       FLASHCACHEDELWHITELISTALL_CMD,
+};
+
+#define FLASHCACHEADDNCPID     _IOW(FLASHCACHE_IOCTL, FLASHCACHEADDNCPID_CMD, pid_t)
+#define FLASHCACHEDELNCPID     _IOW(FLASHCACHE_IOCTL, FLASHCACHEDELNCPID_CMD, pid_t)
+#define FLASHCACHEDELNCALL     _IOW(FLASHCACHE_IOCTL, FLASHCACHEDELNCALL_CMD, pid_t)
+
+#define FLASHCACHEADDBLACKLIST         FLASHCACHEADDNCPID
+#define FLASHCACHEDELBLACKLIST         FLASHCACHEDELNCPID
+#define FLASHCACHEDELALLBLACKLIST      FLASHCACHEDELNCALL
+
+#define FLASHCACHEADDWHITELIST         _IOW(FLASHCACHE_IOCTL, FLASHCACHEADDWHITELIST_CMD, pid_t)
+#define FLASHCACHEDELWHITELIST         _IOW(FLASHCACHE_IOCTL, FLASHCACHEDELWHITELIST_CMD, pid_t)
+#define FLASHCACHEDELALLWHITELIST      _IOW(FLASHCACHE_IOCTL, FLASHCACHEDELWHITELISTALL_CMD, pid_t)
+
+#endif
diff -ruN a/mysql-test/r/mysqldump.result b/mysql-test/r/mysqldump.result
--- a/mysql-test/r/mysqldump.result	2010-07-28 16:47:58.334083833 +0400
+++ b/mysql-test/r/mysqldump.result	2010-07-28 16:48:14.805318437 +0400
@@ -1832,7 +1832,7 @@
 # Bug#21288 mysqldump segmentation fault when using --where
 #
 create table t1 (a int);
-mysqldump: Couldn't execute 'SELECT /*!40001 SQL_NO_CACHE */ * FROM `t1` WHERE xx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx': You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' at line 1 (1064)
+mysqldump: Couldn't execute 'SELECT /*!40001 SQL_NO_CACHE */ /*!50084 SQL_NO_FCACHE */ * FROM `t1` WHERE xx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx': You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' at line 1 (1064)
 mysqldump: Got error: 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' at line 1 when retrieving data from server
 
 /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
diff -ruN a/patch_info/sql_no_fcache.info b/patch_info/sql_no_fcache.info
--- a/patch_info/sql_no_fcache.info	1970-01-01 03:00:00.000000000 +0300
+++ b/patch_info/sql_no_fcache.info	2010-07-28 16:47:59.915439165 +0400
@@ -0,0 +1,6 @@
+File=sql_no_fcache.patch
+Name=Support for flashcache including the SQL_NO_FCACHE option that prevents blocks from being cached during a query.
+Version=1.0
+Author=Facebook
+License=GPL
+Comment=
diff -ruN a/sql/lex.h b/sql/lex.h
--- a/sql/lex.h	2010-07-28 16:47:58.575318748 +0400
+++ b/sql/lex.h	2010-07-28 16:48:00.134078469 +0400
@@ -500,6 +500,7 @@
   { "SQL_CACHE",        SYM(SQL_CACHE_SYM)},
   { "SQL_CALC_FOUND_ROWS", SYM(SQL_CALC_FOUND_ROWS)},
   { "SQL_NO_CACHE",	SYM(SQL_NO_CACHE_SYM)},
+  { "SQL_NO_FCACHE",   SYM(SQL_NO_FCACHE_SYM)},
   { "SQL_SMALL_RESULT", SYM(SQL_SMALL_RESULT)},
   { "SQL_THREAD",	SYM(SQL_THREAD)},
   { "SQL_TSI_FRAC_SECOND", SYM(FRAC_SECOND_SYM)},
diff -ruN a/sql/mysqld.cc b/sql/mysqld.cc
--- a/sql/mysqld.cc	2010-07-28 16:47:58.565318871 +0400
+++ b/sql/mysqld.cc	2010-07-28 16:48:03.004544367 +0400
@@ -45,6 +45,11 @@
 #define OPT_NDB_SHM_DEFAULT 0
 #endif
 #endif
+#if defined(__linux__)
+#include <mntent.h>
+#include <sys/statfs.h>
+#include "flashcache_ioctl.h"
+#endif//__linux__
 
 #ifndef DEFAULT_SKIP_THREAD_PRIORITY
 #define DEFAULT_SKIP_THREAD_PRIORITY 0
@@ -593,6 +598,11 @@
 ulong max_connections, max_connect_errors;
 uint  max_user_connections= 0;
 ulonglong denied_connections = 0;
+
+/* flashcache */
+int cachedev_fd;
+my_bool cachedev_enabled= FALSE;
+
 /**
   Limit of the total number of prepared statements in the server.
   Is necessary to protect the server against out-of-memory attacks.
@@ -4391,6 +4401,97 @@
 }
 #endif//DBUG_OFF
 
+#if defined(__linux__)
+/*
+ * Auto detect if we support flash cache on the host system.
+ * This needs to be called before we setuid away from root
+ * to avoid permission problems on opening the device node.
+ */
+static void init_cachedev(void)
+{
+  struct statfs stfs_data_home_dir;
+  struct statfs stfs;
+  struct mntent *ent;
+  pid_t pid = getpid();
+  FILE *mounts;
+  char *error_message= NULL;
+
+  // disabled by default
+  cachedev_fd = -1;
+  cachedev_enabled= FALSE;
+
+  if (!mysql_data_home)
+  {
+    error_message= "mysql_data_home not set";
+    goto epilogue;
+  }
+
+  if (statfs(mysql_data_home, &stfs_data_home_dir) < 0)
+  {
+    error_message= "statfs failed";
+    goto epilogue;
+  }
+
+  mounts = setmntent("/etc/mtab", "r");
+  if (mounts == NULL)
+  {
+    error_message= "setmntent failed";
+    goto epilogue;
+  }
+
+  while ((ent = getmntent(mounts)) != NULL)
+  {
+    if (statfs(ent->mnt_dir, &stfs) < 0)
+      continue;
+    if (memcmp(&stfs.f_fsid, &stfs_data_home_dir.f_fsid, sizeof(fsid_t)) == 0)
+      break;
+  }
+  endmntent(mounts);
+
+  if (ent == NULL)
+  {
+    error_message= "getmntent loop failed";
+    goto epilogue;
+  }
+
+  cachedev_fd = open(ent->mnt_fsname, O_RDONLY);
+  if (cachedev_fd < 0)
+  {
+    error_message= "open flash device failed";
+    goto epilogue;
+  }
+
+  /* cleanup previous whitelistings */
+  if (ioctl(cachedev_fd, FLASHCACHEDELALLWHITELIST, &pid) < 0)
+  {
+    close(cachedev_fd);
+    cachedev_fd = -1;
+    error_message= "ioctl failed";
+  } else {
+    ioctl(cachedev_fd, FLASHCACHEADDWHITELIST, &pid);
+  }
+
+epilogue:
+  sql_print_information("Flashcache bypass: %s",
+      (cachedev_fd > 0) ? "enabled" : "disabled");
+  if (error_message)
+    sql_print_information("Flashcache setup error is : %s\n", error_message);
+  else
+    cachedev_enabled= TRUE;
+
+}
+
+static void cleanup_cachedev(void)
+{
+  pid_t pid = getpid();
+
+  if (cachedev_enabled) {
+    ioctl(cachedev_fd, FLASHCACHEDELWHITELIST, &pid);
+    close(cachedev_fd);
+    cachedev_fd = -1;
+  }
+}
+#endif//__linux__
 
 #ifdef __WIN__
 int win_main(int argc, char **argv)
@@ -4495,6 +4596,10 @@
   test_lc_time_sz();
 #endif
 
+#if defined(__linux__)
+  init_cachedev();
+#endif//__linux__
+
   /*
     We have enough space for fiddling with the argv, continue
   */
@@ -4696,6 +4801,10 @@
   clean_up_mutexes();
   my_end(opt_endinfo ? MY_CHECK_ERROR | MY_GIVE_INFO : 0);
 
+#if defined(__linux__)
+  cleanup_cachedev();
+#endif//__linux__
+
   exit(0);
   return(0);					/* purecov: deadcode */
 }
@@ -7853,6 +7962,7 @@
   {"Delayed_errors",           (char*) &delayed_insert_errors,  SHOW_LONG},
   {"Delayed_insert_threads",   (char*) &delayed_insert_threads, SHOW_LONG_NOFLUSH},
   {"Delayed_writes",           (char*) &delayed_insert_writes,  SHOW_LONG},
+  {"Flashcache_enabled",       (char*) &cachedev_enabled,       SHOW_BOOL },
   {"Flush_commands",           (char*) &refresh_version,        SHOW_LONG_NOFLUSH},
   {"Handler_commit",           (char*) offsetof(STATUS_VAR, ha_commit_count), SHOW_LONG_STATUS},
   {"Handler_delete",           (char*) offsetof(STATUS_VAR, ha_delete_count), SHOW_LONG_STATUS},
diff -ruN a/sql/mysql_priv.h b/sql/mysql_priv.h
--- a/sql/mysql_priv.h	2010-07-28 16:47:58.575318748 +0400
+++ b/sql/mysql_priv.h	2010-07-28 16:48:05.505952089 +0400
@@ -819,6 +819,8 @@
 */
 extern ulong server_id, concurrency;
 
+/* flashcache */
+extern int cachedev_fd;
 
 typedef my_bool (*qc_engine_callback)(THD *thd, char *table_key,
                                       uint key_length,
diff -ruN a/sql/sql_lex.cc b/sql/sql_lex.cc
--- a/sql/sql_lex.cc	2010-07-28 16:47:58.555318714 +0400
+++ b/sql/sql_lex.cc	2010-07-28 16:48:07.794069239 +0400
@@ -306,6 +306,7 @@
   lex->describe= 0;
   lex->subqueries= FALSE;
   lex->context_analysis_only= 0;
+  lex->disable_flashcache= FALSE;
   lex->derived_tables= 0;
   lex->lock_option= TL_READ;
   lex->safe_to_cache_query= 1;
diff -ruN a/sql/sql_lex.h b/sql/sql_lex.h
--- a/sql/sql_lex.h	2010-07-28 16:47:58.575318748 +0400
+++ b/sql/sql_lex.h	2010-07-28 16:48:08.405691834 +0400
@@ -1722,6 +1722,7 @@
 
   uint8 context_analysis_only;
   bool safe_to_cache_query;
+  bool disable_flashcache;
   bool subqueries, ignore;
   st_parsing_options parsing_options;
   Alter_info alter_info;
diff -ruN a/sql/sql_select.cc b/sql/sql_select.cc
--- a/sql/sql_select.cc	2010-07-28 16:47:58.555318714 +0400
+++ b/sql/sql_select.cc	2010-07-28 16:48:13.414069437 +0400
@@ -37,6 +37,12 @@
 #include <hash.h>
 #include <ft_global.h>
 
+#include <sys/syscall.h>
+#include <sys/ioctl.h>
+#if defined(__linux__)
+#include "flashcache_ioctl.h"
+#endif//__linux__
+
 const char *join_type_str[]={ "UNKNOWN","system","const","eq_ref","ref",
 			      "MAYBE_REF","ALL","range","index","fulltext",
 			      "ref_or_null","unique_subquery","index_subquery",
@@ -239,9 +245,20 @@
                    ulong setup_tables_done_option)
 {
   bool res;
+#if defined(__linux__)
+  pid_t pid;
+#endif
   register SELECT_LEX *select_lex = &lex->select_lex;
   DBUG_ENTER("handle_select");
 
+#if defined(__linux__)
+  if(lex->disable_flashcache && cachedev_fd > 0)
+  {
+    pid = syscall(SYS_gettid);
+    ioctl(cachedev_fd, FLASHCACHEADDNCPID, &pid);
+  }
+#endif//__linux__
+ 
   if (select_lex->master_unit()->is_union() || 
       select_lex->master_unit()->fake_select_lex)
     res= mysql_union(thd, lex, result, &lex->unit, setup_tables_done_option);
@@ -274,6 +291,12 @@
   if (unlikely(res))
     result->abort();
 
+#if defined(__linux__)
+  if (lex->disable_flashcache && cachedev_fd > 0)
+  {
+    ioctl(cachedev_fd, FLASHCACHEDELNCPID, &pid);
+  }
+#endif//__linux__ 
   DBUG_RETURN(res);
 }
 
diff -ruN a/sql/sql_yacc.yy b/sql/sql_yacc.yy
--- a/sql/sql_yacc.yy	2010-07-28 16:47:58.565318871 +0400
+++ b/sql/sql_yacc.yy	2010-07-28 16:48:14.205317990 +0400
@@ -1164,6 +1164,7 @@
 %token  SQL_CACHE_SYM
 %token  SQL_CALC_FOUND_ROWS
 %token  SQL_NO_CACHE_SYM
+%token  SQL_NO_FCACHE_SYM
 %token  SQL_SMALL_RESULT
 %token  SQL_SYM                       /* SQL-2003-R */
 %token  SQL_THREAD
@@ -6752,6 +6753,10 @@
             Lex->select_lex.options&= ~OPTION_TO_QUERY_CACHE;
             Lex->select_lex.sql_cache= SELECT_LEX::SQL_NO_CACHE;
           }
+	| SQL_NO_FCACHE_SYM
+	  {
+	    Lex->disable_flashcache= TRUE;
+	  }
         | SQL_CACHE_SYM
           {
             /*