Now that we have cleaned up journal_async_commit, it's safe to enable
it all the time. But we only want to do so if ext4-specific INCOMPAT
features are enabled, since otherwise we will prevent the filesystem
from being mounted using ext3.
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
---
Documentation/filesystems/ext4.txt | 8 ++++++--
fs/ext4/super.c | 26 ++++++++++++++++++++++++--
2 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 3e329db..4f8d73a 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -135,8 +135,12 @@ ro Mount filesystem read only. Note that ext4 will
writes to the filesystem.
journal_async_commit Commit block can be written to disk without waiting
- for descriptor blocks. If enabled older kernels cannot
- mount the device.
+ for descriptor blocks. This mount option will be
+ automatically enabled if ext4-specific INCOMPAT
+ features are present in the file system.
+
+nojournal_async_commit Disable the journal_async_commit option, even
+ for ext4 filesystems.
journal=update Update the ext4 file system's journal to the current
format.
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f1815d3..f644a5c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -75,6 +75,15 @@ static int ext4_unfreeze(struct super_block *sb);
static void ext4_write_super(struct super_block *sb);
static int ext4_freeze(struct super_block *sb);
+/*
+ * If ext4 filesystem features are enabled, then enable async_commits
+ * by default.
+ */
+#define ASYNC_COMMIT_DEFAULT(sb) (EXT4_HAS_INCOMPAT_FEATURE(sb, \
+ (EXT4_FEATURE_INCOMPAT_EXTENTS| \
+ EXT4_FEATURE_INCOMPAT_64BIT| \
+ EXT4_FEATURE_INCOMPAT_FLEX_BG)))
+
ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
struct ext4_group_desc *bg)
@@ -845,8 +854,13 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
*/
seq_puts(seq, ",barrier=");
seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
- if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
- seq_puts(seq, ",journal_async_commit");
+ if (ASYNC_COMMIT_DEFAULT(sb)) {
+ if (!test_opt(sb, JOURNAL_ASYNC_COMMIT))
+ seq_puts(seq, ",nojournal_async_commit");
+ } else {
+ if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
+ seq_puts(seq, ",journal_async_commit");
+ }
if (test_opt(sb, NOBH))
seq_puts(seq, ",nobh");
if (test_opt(sb, I_VERSION))
@@ -1050,6 +1064,7 @@ enum {
Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
Opt_journal_update, Opt_journal_dev,
Opt_journal_checksum, Opt_journal_async_commit,
+ Opt_nojournal_async_commit,
Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
Opt_data_err_abort, Opt_data_err_ignore, Opt_mb_history_length,
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
@@ -1092,6 +1107,7 @@ static const match_table_t tokens = {
{Opt_journal_dev, "journal_dev=%u"},
{Opt_journal_checksum, "journal_checksum"},
{Opt_journal_async_commit, "journal_async_commit"},
+ {Opt_nojournal_async_commit, "nojournal_async_commit"},
{Opt_abort, "abort"},
{Opt_data_journal, "data=journal"},
{Opt_data_ordered, "data=ordered"},
@@ -1284,6 +1300,9 @@ static int parse_options(char *options, struct super_block *sb,
case Opt_journal_async_commit:
set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
break;
+ case Opt_nojournal_async_commit:
+ clear_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
+ break;
case Opt_noload:
set_opt(sbi->s_mount_opt, NOLOAD);
break;
@@ -2422,6 +2441,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
*/
set_opt(sbi->s_mount_opt, DELALLOC);
+ if (ASYNC_COMMIT_DEFAULT(sb))
+ set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
+
if (!parse_options((char *) data, sb, &journal_devnum,
&journal_ioprio, NULL, 0))
goto failed_mount;
--
1.6.3.2.1.gb9f7d.dirty
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
