From bbae8bcc49bc4d002221dab52c79a50a82e7cd1f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 6 Apr 2009 17:16:47 -0700 Subject: 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 --- fs/ext3/Kconfig | 19 +++++++++++++++++++ fs/ext3/super.c | 8 +++++++- 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/fs/ext3/Kconfig b/fs/ext3/Kconfig index 8e0cfe4..fb3c1a2 100644 --- a/fs/ext3/Kconfig +++ b/fs/ext3/Kconfig @@ -28,6 +28,25 @@ config EXT3_FS To compile this file system support as a module, choose M here: the module will be called ext3. +config EXT3_DEFAULTS_TO_ORDERED + bool "Default to 'data=ordered' in ext3 (legacy option)" + depends on EXT3_FS + help + If a filesystem does not explicitly specify a data ordering + mode, and the journal capability allowed it, ext3 used to + historically default to 'data=ordered'. + + That was a rather unfortunate choice, because it leads to all + kinds of latency problems, and the 'data=writeback' mode is more + appropriate these days. + + You should probably always answer 'n' here, and if you really + want to use 'data=ordered' mode, set it in the filesystem itself + with 'tune2fs -o journal_data_ordered'. + + But if you really want to enable the legacy default, you can do + so by answering 'y' to this question. + config EXT3_FS_XATTR bool "Ext3 extended attributes" depends on EXT3_FS diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 9e5b8e3..599dbfe 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; -- cgit v1.1