GFS2: Clean up releasepage
authorSteven Whitehouse <swhiteho@redhat.com>
Tue, 26 Nov 2013 13:21:08 +0000 (13:21 +0000)
committerSteven Whitehouse <swhiteho@redhat.com>
Fri, 3 Jan 2014 09:58:41 +0000 (09:58 +0000)
For historical reasons, we drop and retake the log lock in ->releasepage()
however, since there is no reason why we cannot hold the log lock over
the whole function, this allows some simplification. In particular,
pinning a buffer is only ever done under the log lock, so it is possible
here to remove the test for pinned buffers in the second loop, since it
is impossible for that to happen (it is also tested in the first loop).

As a result, two tests made later in the second loop become constants
and can also be reduced to the only possible branch. So the net result
is to remove various bits of unreachable code and make this more
readable.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
fs/gfs2/aops.c

index 73f3e4ee403793e1ae39c75b5d652f64c6a4b52a..cf858dad75d9a6d3580a486d56c0f46f55146336 100644 (file)
@@ -1080,30 +1080,22 @@ int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
                bh = bh->b_this_page;
        } while(bh != head);
        spin_unlock(&sdp->sd_ail_lock);
-       gfs2_log_unlock(sdp);
 
        head = bh = page_buffers(page);
        do {
-               gfs2_log_lock(sdp);
                bd = bh->b_private;
                if (bd) {
                        gfs2_assert_warn(sdp, bd->bd_bh == bh);
-                       if (!list_empty(&bd->bd_list)) {
-                               if (!buffer_pinned(bh))
-                                       list_del_init(&bd->bd_list);
-                               else
-                                       bd = NULL;
-                       }
-                       if (bd)
-                               bd->bd_bh = NULL;
+                       if (!list_empty(&bd->bd_list))
+                               list_del_init(&bd->bd_list);
+                       bd->bd_bh = NULL;
                        bh->b_private = NULL;
-               }
-               gfs2_log_unlock(sdp);
-               if (bd)
                        kmem_cache_free(gfs2_bufdata_cachep, bd);
+               }
 
                bh = bh->b_this_page;
        } while (bh != head);
+       gfs2_log_unlock(sdp);
 
        return try_to_free_buffers(page);