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>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 04338009793a..a6f314249574 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -458,8 +458,7 @@ static void ext4_xattr_update_super_block(handle_t *handle,
 
         if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
                 EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR);
-                sb->s_dirt = 1;
-                ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
+                ext4_handle_dirty_super(handle, sb);
         }
 }