[GFS2] Clean up invalidatepage/releasepage

This patch fixes some bugs relating to journaled data files by cleaning
up the gfs2_invalidatepage() and gfs2_releasepage() functions. We now
never block during gfs2_releasepage(), instead we always either release
or refuse to release depending on the status of the buffers.

This fixes Red Hat bugzillas #248969 and #252392.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 00ab6c070a15..d0e6b42c86e1 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -229,8 +229,10 @@ static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
                 list_del(&bd->bd_ail_st_list);
                 list_del(&bd->bd_ail_gl_list);
                 atomic_dec(&bd->bd_gl->gl_ail_count);
-                bh_ip = GFS2_I(bd->bd_bh->b_page->mapping->host);
-                gfs2_meta_cache_flush(bh_ip);
+                if (bd->bd_bh->b_page->mapping) {
+                        bh_ip = GFS2_I(bd->bd_bh->b_page->mapping->host);
+                        gfs2_meta_cache_flush(bh_ip);
+                }
                 brelse(bd->bd_bh);
         }
 }