ext3: make default data ordering mode configurable

This makes the defautl ext3 data ordering mode (when no explicit
ordering is set) configurable, so as to allow people to default to
'data=writeback' and get the resulting latency improvements.

This is a non-issue if a filesystem has been explicitly set to some
ordering (with 'tune2fs').

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 9e5b8e387e1e..599dbfe504c3 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -44,6 +44,12 @@
 #include "acl.h"
 #include "namei.h"
 
+#ifdef CONFIG_EXT3_DEFAULTS_TO_ORDERED
+  #define EXT3_MOUNT_DEFAULT_DATA_MODE EXT3_MOUNT_ORDERED_DATA
+#else
+  #define EXT3_MOUNT_DEFAULT_DATA_MODE EXT3_MOUNT_WRITEBACK_DATA
+#endif
+
 static int ext3_load_journal(struct super_block *, struct ext3_super_block *,
                              unsigned long journal_devnum);
 static int ext3_create_journal(struct super_block *, struct ext3_super_block *,
@@ -1919,7 +1925,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
                    cope, else JOURNAL_DATA */
                 if (journal_check_available_features
                     (sbi->s_journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE))
-                        set_opt(sbi->s_mount_opt, ORDERED_DATA);
+                        set_opt(sbi->s_mount_opt, DEFAULT_DATA_MODE);
                 else
                         set_opt(sbi->s_mount_opt, JOURNAL_DATA);
                 break;