GFS2: Don't cache iopen glocks

This patch makes GFS2 immediately reclaim/delete all iopen glocks
as soon as they're dequeued. This allows deleters to get an
EXclusive lock on iopen so files are deleted properly instead of
being set as unlinked.

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

fs/gfs2/inode.c

@@ -189,6 +189,7 @@ struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type,
 	return inode;
 
 fail_refresh:
+	ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
 	ip->i_iopen_gh.gh_gl->gl_object = NULL;
 	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 fail_iopen:

fs/gfs2/super.c

@@ -1444,6 +1444,7 @@ static void gfs2_evict_inode(struct inode *inode)
 	/* Must not read inode block until block type has been verified */
 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, &gh);
 	if (unlikely(error)) {
+		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 		goto out;
 	}
@@ -1514,8 +1515,10 @@ static void gfs2_evict_inode(struct inode *inode)
 	if (gfs2_rs_active(ip->i_res))
 		gfs2_rs_deltree(ip->i_res);
 
-	if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags))
+	if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
+		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
 		gfs2_glock_dq(&ip->i_iopen_gh);
+	}
 	gfs2_holder_uninit(&ip->i_iopen_gh);
 	gfs2_glock_dq_uninit(&gh);
 	if (error && error != GLR_TRYFAILED && error != -EROFS)
@@ -1534,6 +1537,7 @@ static void gfs2_evict_inode(struct inode *inode)
 	ip->i_gl = NULL;
 	if (ip->i_iopen_gh.gh_gl) {
 		ip->i_iopen_gh.gh_gl->gl_object = NULL;
+		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 	}
 }