gfs2: print mapping->nrpages in glock dump for address space glocks

This patch makes the glock dumps in debugfs print the number of pages
(nrpages) for address space glocks. This will aid in debugging.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -1978,7 +1978,13 @@ void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
 	char gflags_buf[32];
 	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	char fs_id_buf[sizeof(sdp->sd_fsname) + 7];
+	unsigned long nrpages = 0;
 
+	if (gl->gl_ops->go_flags & GLOF_ASPACE) {
+		struct address_space *mapping = gfs2_glock2aspace(gl);
+
+		nrpages = mapping->nrpages;
+	}
 	memset(fs_id_buf, 0, sizeof(fs_id_buf));
 	if (fsid && sdp) /* safety precaution */
 		sprintf(fs_id_buf, "fsid=%s: ", sdp->sd_fsname);
@@ -1987,7 +1993,8 @@ void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
 	if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
 		dtime = 0;
 	gfs2_print_dbg(seq, "%sG:  s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d "
-		       "v:%d r:%d m:%ld\n", fs_id_buf, state2str(gl->gl_state),
+		       "v:%d r:%d m:%ld p:%lu\n",
+		       fs_id_buf, state2str(gl->gl_state),
 		       gl->gl_name.ln_type,
 		       (unsigned long long)gl->gl_name.ln_number,
 		       gflags2str(gflags_buf, gl),
@@ -1995,7 +2002,7 @@ void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid)
 		       state2str(gl->gl_demote_state), dtime,
 		       atomic_read(&gl->gl_ail_count),
 		       atomic_read(&gl->gl_revokes),
-		  (int)gl->gl_lockref.count, gl->gl_hold_time);
+		       (int)gl->gl_lockref.count, gl->gl_hold_time, nrpages);
 
 	list_for_each_entry(gh, &gl->gl_holders, gh_list)
 		dump_holder(seq, gh, fs_id_buf);