fs/ufs: get rid of write_super

This patch makes UFS stop using the VFS '->write_super()' method along with
the 's_dirt' superblock flag, because they are on their way out.

The way we implement this is that we schedule a delay job instead relying on
's_dirt' and '->write_super()'.

The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblocks using the '->write_super()' call-back.  But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.

Tested using fsstress from the LTP project.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/ufs/ialloc.c b/fs/ufs/ialloc.c
index 4ec5c1085a87..e84cbe21b986 100644
--- a/fs/ufs/ialloc.c
+++ b/fs/ufs/ialloc.c
@@ -116,7 +116,7 @@ void ufs_free_inode (struct inode * inode)
         if (sb->s_flags & MS_SYNCHRONOUS)
                 ubh_sync_block(UCPI_UBH(ucpi));
         
-        sb->s_dirt = 1;
+        ufs_mark_sb_dirty(sb);
         unlock_super (sb);
         UFSD("EXIT\n");
 }
@@ -288,7 +288,7 @@ cg_found:
         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
         if (sb->s_flags & MS_SYNCHRONOUS)
                 ubh_sync_block(UCPI_UBH(ucpi));
-        sb->s_dirt = 1;
+        ufs_mark_sb_dirty(sb);
 
         inode->i_ino = cg * uspi->s_ipg + bit;
         inode_init_owner(inode, dir, mode);