[GFS2] Drop log lock on I/O error & tidy up

This patch drops the log spinlock when an I/O error occurs
to avoid any possible problems in case of blocking or
recursion in the I/O error routine. It also has a few
cosmetic changes to tidy up various other files.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index da49973..fe46d563 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -226,8 +226,11 @@
 			gfs2_assert(sdp, bd->bd_ail == ai);
 
 			if (!buffer_busy(bh)) {
-				if (!buffer_uptodate(bh))
+				if (!buffer_uptodate(bh)) {
+					gfs2_log_unlock(sdp);
 					gfs2_io_error_bh(sdp, bh);
+					gfs2_log_lock(sdp);
+				}
 				list_move(&bd->bd_ail_st_list,
 					  &ai->ai_ail2_list);
 				continue;