jffs2: get rid of jffs2_sync_super
authorArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Mon, 7 May 2012 16:02:46 +0000 (19:02 +0300)
committerDavid Woodhouse <David.Woodhouse@intel.com>
Mon, 14 May 2012 04:24:23 +0000 (23:24 -0500)
commit208b14e507c00ff7f108e1a388dd3d8cc805a443
tree34ec5a82825cf87d2d9a2856bde10f722a22cd14
parente832579fd100eb4f9658bdfefd61caf86a6cbff1
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>
fs/jffs2/jffs2_fs_sb.h
fs/jffs2/os-linux.h
fs/jffs2/super.c
fs/jffs2/wbuf.c