ext4: Clean up s_dirt handling
We don't need to set s_dirt in most of the ext4 code when journaling
is enabled. In ext3/4 some of the summary statistics for # of free
inodes, blocks, and directories are calculated from the per-block
group statistics when the file system is mounted or unmounted. As a
result the superblock doesn't have to be updated, either via the
journal or by setting s_dirt. There are a few exceptions, most
notably when resizing the file system, where the superblock needs to
be modified --- and in that case it should be done as a journalled
operation if possible, and s_dirt set only in no-journal mode.
This patch will optimize out some unneeded disk writes when using ext4
with a journal.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 25c4b31..ac37750 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -279,7 +279,7 @@
err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
if (!fatal)
fatal = err;
- sb->s_dirt = 1;
+ ext4_mark_super_dirty(sb);
} else
ext4_error(sb, "bit already cleared for inode %lu", ino);
@@ -965,7 +965,7 @@
percpu_counter_dec(&sbi->s_freeinodes_counter);
if (S_ISDIR(mode))
percpu_counter_inc(&sbi->s_dirs_counter);
- sb->s_dirt = 1;
+ ext4_mark_super_dirty(sb);
if (sbi->s_log_groups_per_flex) {
flex_group = ext4_flex_group(sbi, group);