jffs2: get rid of jffs2_sync_super

Currently JFFS2 file-system maps the VFS "superblock" abstraction to the
write-buffer. Namely, it uses VFS services to synchronize the write-buffer
periodically.

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 superblock 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 no matter what. 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.

This patch switches the JFFS2 write-buffer management from
'->write_super()'/'->s_dirt' to a delayed work. Instead of setting the 's_dirt'
flag we just schedule a delayed work for synchronizing the write-buffer.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 0 insertions, 13 deletions

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index b36aa950d2a6..61ea41389f90 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -63,18 +63,6 @@ static void jffs2_i_init_once(void *foo)
         inode_init_once(&f->vfs_inode);
 }
 
-static void jffs2_write_super(struct super_block *sb)
-{
-        struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
-
-        sb->s_dirt = 0;
-
-        if (!(sb->s_flags & MS_RDONLY)) {
-                jffs2_dbg(1, "%s()\n", __func__);
-                jffs2_flush_wbuf_gc(c, 0);
-        }
-}
-
 static const char *jffs2_compr_name(unsigned int compr)
 {
         switch (compr) {
@@ -263,7 +251,6 @@ static const struct super_operations jffs2_super_operations =
         .alloc_inode =  jffs2_alloc_inode,
         .destroy_inode =jffs2_destroy_inode,
         .put_super =    jffs2_put_super,
-        .write_super =  jffs2_write_super,
         .statfs =       jffs2_statfs,
         .remount_fs =   jffs2_remount_fs,
         .evict_inode =  jffs2_evict_inode,