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/ext4.h b/fs/ext4/ext4.h
index 19a4de5..8b56b53 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1860,6 +1860,12 @@
spin_unlock(ext4_group_lock_ptr(sb, group));
}
+static inline void ext4_mark_super_dirty(struct super_block *sb)
+{
+ if (EXT4_SB(sb)->s_journal == NULL)
+ sb->s_dirt =1;
+}
+
/*
* Inodes and files operations
*/