devices: ignore lvm1 and pool devices

lib/filters/filter-signature.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2004 Luca Berra
+ * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "lib.h"
+#include "filter.h"
+
+#ifdef __linux__
+
+#define BUFSIZE 4096
+
+static int _ignore_signature(struct dev_filter *f __attribute__((unused)),
+		      struct device *dev)
+{
+	char buf[BUFSIZE];
+	int ret = 0;
+
+	if (!dev_open_readonly(dev)) {
+		stack;
+		return -1;
+	}
+
+	memset(buf, 0, BUFSIZE);
+
+	if (!dev_read(dev, 0, BUFSIZE, DEV_IO_SIGNATURES, buf)) {
+		log_debug_devs("%s: Skipping: error in signature detection",
+			       dev_name(dev));
+		ret = 0;
+		goto out;
+	}
+
+	if (dev_is_lvm1(dev, buf, BUFSIZE)) {
+		log_debug_devs("%s: Skipping lvm1 device", dev_name(dev));
+		ret = 0;
+		goto out;
+	}
+
+	if (dev_is_pool(dev, buf, BUFSIZE)) {
+		log_debug_devs("%s: Skipping gfs-pool device", dev_name(dev));
+		ret = 0;
+		goto out;
+	}
+	ret = 1;
+
+out:
+	dev_close(dev);
+
+	return ret;
+}
+
+static void _destroy(struct dev_filter *f)
+{
+	if (f->use_count)
+		log_error(INTERNAL_ERROR "Destroying signature filter while in use %u times.", f->use_count);
+
+	dm_free(f);
+}
+
+struct dev_filter *signature_filter_create(struct dev_types *dt)
+{
+	struct dev_filter *f;
+
+	if (!(f = dm_zalloc(sizeof(*f)))) {
+		log_error("md filter allocation failed");
+		return NULL;
+	}
+
+	f->passes_filter = _ignore_signature;
+	f->destroy = _destroy;
+	f->use_count = 0;
+	f->private = dt;
+
+	log_debug_devs("signature filter initialised.");
+
+	return f;
+}
+
+#else
+
+struct dev_filter *signature_filter_create(struct dev_types *dt)
+{
+	return NULL;
+}
+
+#endif

lib/filters/filter.h

@@ -31,6 +31,7 @@ struct dev_filter *persistent_filter_create(struct dev_types *dt,
 					    struct dev_filter *f,
 					    const char *file);
 struct dev_filter *sysfs_filter_create(void);
+struct dev_filter *signature_filter_create(struct dev_types *dt);
 
 struct dev_filter *internal_filter_create(void);
 int internal_filter_allow(struct dm_pool *mem, struct device *dev);