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-rw-r--r--libblkid/src/topology/lvm.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/libblkid/src/topology/lvm.c b/libblkid/src/topology/lvm.c
new file mode 100644
index 0000000..6ab7a50
--- /dev/null
+++ b/libblkid/src/topology/lvm.c
@@ -0,0 +1,144 @@
+/*
+ * lvm topology
+ * -- this is fallback for old systems where the topology information is not
+ * exported by sysfs
+ *
+ * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ *
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "topology.h"
+
+#ifndef LVM_BLK_MAJOR
+# define LVM_BLK_MAJOR 58
+#endif
+
+static int is_lvm_device(dev_t devno)
+{
+ if (major(devno) == LVM_BLK_MAJOR)
+ return 1;
+ return blkid_driver_has_major("lvm", major(devno));
+}
+
+static int probe_lvm_tp(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ const char *paths[] = {
+ "/usr/local/sbin/lvdisplay",
+ "/usr/sbin/lvdisplay",
+ "/sbin/lvdisplay"
+ };
+ int lvpipe[] = { -1, -1 }, stripes = 0, stripesize = 0;
+ FILE *stream = NULL;
+ char *cmd = NULL, *devname = NULL, buf[1024];
+ size_t i;
+ dev_t devno = blkid_probe_get_devno(pr);
+
+ if (!devno)
+ goto nothing; /* probably not a block device */
+ if (!is_lvm_device(devno))
+ goto nothing;
+
+ for (i = 0; i < ARRAY_SIZE(paths); i++) {
+ struct stat sb;
+ if (stat(paths[i], &sb) == 0) {
+ cmd = (char *) paths[i];
+ break;
+ }
+ }
+
+ if (!cmd)
+ goto nothing;
+
+ devname = blkid_devno_to_devname(devno);
+ if (!devname)
+ goto nothing;
+
+ if (pipe(lvpipe) < 0) {
+ DBG(LOWPROBE, ul_debug("Failed to open pipe: errno=%d", errno));
+ goto nothing;
+ }
+
+ switch (fork()) {
+ case 0:
+ {
+ char *lvargv[3];
+
+ /* Plumbing */
+ close(lvpipe[0]);
+
+ if (lvpipe[1] != STDOUT_FILENO)
+ dup2(lvpipe[1], STDOUT_FILENO);
+
+ if (drop_permissions() != 0)
+ exit(1);
+
+ lvargv[0] = cmd;
+ lvargv[1] = devname;
+ lvargv[2] = NULL;
+
+ execv(lvargv[0], lvargv);
+
+ DBG(LOWPROBE, ul_debug("Failed to execute %s: errno=%d", cmd, errno));
+ exit(1);
+ }
+ case -1:
+ DBG(LOWPROBE, ul_debug("Failed to forking: errno=%d", errno));
+ goto nothing;
+ default:
+ break;
+ }
+
+ stream = fdopen(lvpipe[0], "r" UL_CLOEXECSTR);
+ if (!stream)
+ goto nothing;
+
+ while (fgets(buf, sizeof(buf), stream) != NULL) {
+ if (!strncmp(buf, "Stripes", 7))
+ ignore_result( sscanf(buf, "Stripes %d", &stripes) );
+
+ if (!strncmp(buf, "Stripe size", 11))
+ ignore_result( sscanf(buf, "Stripe size (KByte) %d", &stripesize) );
+ }
+
+ if (!stripes)
+ goto nothing;
+
+ blkid_topology_set_minimum_io_size(pr, stripesize << 10);
+ blkid_topology_set_optimal_io_size(pr, (stripes * stripesize) << 10);
+
+ free(devname);
+ fclose(stream);
+ close(lvpipe[1]);
+ return 0;
+
+nothing:
+ free(devname);
+ if (stream)
+ fclose(stream);
+ else if (lvpipe[0] != -1)
+ close(lvpipe[0]);
+ if (lvpipe[1] != -1)
+ close(lvpipe[1]);
+ return 1;
+}
+
+const struct blkid_idinfo lvm_tp_idinfo =
+{
+ .name = "lvm",
+ .probefunc = probe_lvm_tp,
+ .magics = BLKID_NONE_MAGIC
+};
+