gfs2: move GL_SKIP check from glops to do_promote

Before this patch, each individual "go_lock" glock operation (glop)
checked the GL_SKIP flag, and if set, would skip further processing.

This patch changes the logic so the go_lock caller, function go_promote,
checks the GL_SKIP flag before calling the go_lock op in the first place.
This avoids having to unnecessarily unlock gl_lockref.lock only to
re-lock it again.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -502,18 +502,20 @@ __acquires(&gl->gl_lockref.lock)
 			}
 			if (gh->gh_list.prev == &gl->gl_holders &&
 			    glops->go_lock) {
-				spin_unlock(&gl->gl_lockref.lock);
-				/* FIXME: eliminate this eventually */
-				ret = glops->go_lock(gh);
-				spin_lock(&gl->gl_lockref.lock);
-				if (ret) {
-					if (ret == 1)
-						return 2;
-					gh->gh_error = ret;
-					list_del_init(&gh->gh_list);
-					trace_gfs2_glock_queue(gh, 0);
-					gfs2_holder_wake(gh);
-					goto restart;
+				if (!(gh->gh_flags & GL_SKIP)) {
+					spin_unlock(&gl->gl_lockref.lock);
+					/* FIXME: eliminate this eventually */
+					ret = glops->go_lock(gh);
+					spin_lock(&gl->gl_lockref.lock);
+					if (ret) {
+						if (ret == 1)
+							return 2;
+						gh->gh_error = ret;
+						list_del_init(&gh->gh_list);
+						trace_gfs2_glock_queue(gh, 0);
+						gfs2_holder_wake(gh);
+						goto restart;
+					}
 				}
 				set_bit(HIF_HOLDER, &gh->gh_iflags);
 				trace_gfs2_promote(gh, 1);

fs/gfs2/glops.c

@@ -495,7 +495,7 @@ static int inode_go_lock(struct gfs2_holder *gh)
 	struct gfs2_inode *ip = gl->gl_object;
 	int error = 0;
 
-	if (!ip || (gh->gh_flags & GL_SKIP))
+	if (!ip)
 		return 0;
 
 	if (test_bit(GIF_INVALID, &ip->i_flags)) {

fs/gfs2/rgrp.c

@@ -1292,8 +1292,6 @@ int gfs2_rgrp_go_lock(struct gfs2_holder *gh)
 {
 	struct gfs2_rgrpd *rgd = gh->gh_gl->gl_object;
 
-	if (gh->gh_flags & GL_SKIP)
-		return 0;
 	return gfs2_rgrp_bh_get(rgd);
 }