[GFS2] Clean up journaled data writing

This patch cleans up the code for writing journaled data into the log.
It also removes the need to allocate a small "tag" structure for each
block written into the log. Instead we just keep count of the outstanding
I/O so that we can be sure that its all been written at the correct time.
Another result of this patch is that a number of ll_rw_block() calls
have become submit_bh() calls, closing some races at the same time.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --cc fs/gfs2/incore.h
Simple merge

diff --cc fs/gfs2/log.c
Simple merge

diff --cc fs/gfs2/log.h
Simple merge

diff --cc fs/gfs2/lops.c
Simple merge

diff --cc fs/gfs2/meta_io.c
Simple merge

diff --cc fs/gfs2/meta_io.h
Simple merge

diff --cc fs/gfs2/ops_address.c
Simple merge

diff --cc fs/gfs2/ops_fstype.c
Simple merge

diff --cc fs/gfs2/ops_inode.c
Simple merge

diff --cc fs/gfs2/ops_super.c
Simple merge