Commit bbae8bcc authored by Linus Torvalds's avatar Linus Torvalds

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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e0724bf6
...@@ -28,6 +28,25 @@ config EXT3_FS ...@@ -28,6 +28,25 @@ config EXT3_FS
To compile this file system support as a module, choose M here: the To compile this file system support as a module, choose M here: the
module will be called ext3. 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 config EXT3_FS_XATTR
bool "Ext3 extended attributes" bool "Ext3 extended attributes"
depends on EXT3_FS depends on EXT3_FS
......
...@@ -44,6 +44,12 @@ ...@@ -44,6 +44,12 @@
#include "acl.h" #include "acl.h"
#include "namei.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 *, static int ext3_load_journal(struct super_block *, struct ext3_super_block *,
unsigned long journal_devnum); unsigned long journal_devnum);
static int ext3_create_journal(struct super_block *, struct ext3_super_block *, 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) ...@@ -1919,7 +1925,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
cope, else JOURNAL_DATA */ cope, else JOURNAL_DATA */
if (journal_check_available_features if (journal_check_available_features
(sbi->s_journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)) (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 else
set_opt(sbi->s_mount_opt, JOURNAL_DATA); set_opt(sbi->s_mount_opt, JOURNAL_DATA);
break; break;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment