summaryrefslogtreecommitdiffstats
path: root/libblkid/md.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--libblkid/md.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/libblkid/md.c b/libblkid/md.c
new file mode 100644
index 000000000..5eba94787
--- /dev/null
+++ b/libblkid/md.c
@@ -0,0 +1,154 @@
+/*
+ * Linux Software RAID (md) 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/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "topology.h"
+
+#ifndef MD_MAJOR
+#define MD_MAJOR 9
+#endif
+
+#ifndef _IOT__IOTBASE_uint32_t
+#define _IOT__IOTBASE_uint32_t IOT_SIMPLE(uint32_t)
+#endif
+#define _IOT_md_array_info _IOT (_IOTS(uint32_t), 18, 0, 0, 0, 0)
+#define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, struct md_array_info)
+
+struct md_array_info {
+ /*
+ * Generic constant information
+ */
+ uint32_t major_version;
+ uint32_t minor_version;
+ uint32_t patch_version;
+ uint32_t ctime;
+ uint32_t level;
+ uint32_t size;
+ uint32_t nr_disks;
+ uint32_t raid_disks;
+ uint32_t md_minor;
+ uint32_t not_persistent;
+
+ /*
+ * Generic state information
+ */
+ uint32_t utime; /* 0 Superblock update time */
+ uint32_t state; /* 1 State bits (clean, ...) */
+ uint32_t active_disks; /* 2 Number of currently active disks */
+ uint32_t working_disks; /* 3 Number of working disks */
+ uint32_t failed_disks; /* 4 Number of failed disks */
+ uint32_t spare_disks; /* 5 Number of spare disks */
+
+ /*
+ * Personality information
+ */
+ uint32_t layout; /* 0 the array's physical layout */
+ uint32_t chunk_size; /* 1 chunk size in bytes */
+
+};
+
+static int is_md_device(dev_t devno)
+{
+ if (major(devno) == MD_MAJOR)
+ return 1;
+ return blkid_driver_has_major("md", major(devno));
+}
+
+static int probe_md_tp(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ int fd = -1;
+ dev_t disk = 0;
+ dev_t devno = blkid_probe_get_devno(pr);
+ struct md_array_info md;
+
+ if (!devno)
+ goto nothing; /* probably not a block device */
+
+ if (!is_md_device(devno))
+ goto nothing;
+
+ if (blkid_devno_to_wholedisk(devno, NULL, 0, &disk))
+ goto nothing;
+
+ if (disk == devno)
+ fd = pr->fd;
+ else {
+ char *diskpath = blkid_devno_to_devname(disk);
+
+ if (!diskpath)
+ goto nothing;
+
+ fd = open(diskpath, O_RDONLY|O_CLOEXEC);
+ free(diskpath);
+
+ if (fd == -1)
+ goto nothing;
+ }
+
+ memset(&md, 0, sizeof(md));
+
+ if (ioctl(fd, GET_ARRAY_INFO, &md))
+ goto nothing;
+
+ if (fd >= 0 && fd != pr->fd) {
+ close(fd);
+ fd = -1;
+ }
+
+ /*
+ * Ignore levels we don't want aligned (e.g. linear)
+ * and deduct disk(s) from stripe width on RAID4/5/6
+ */
+ switch (md.level) {
+ case 6:
+ md.raid_disks--;
+ /* fallthrough */
+ case 5:
+ case 4:
+ md.raid_disks--;
+ /* fallthrough */
+ case 1:
+ case 0:
+ case 10:
+ break;
+ default:
+ goto nothing;
+ }
+
+ blkid_topology_set_minimum_io_size(pr, md.chunk_size);
+ blkid_topology_set_optimal_io_size(pr, md.chunk_size * md.raid_disks);
+
+ return 0;
+
+nothing:
+ if (fd >= 0 && fd != pr->fd)
+ close(fd);
+ return 1;
+}
+
+const struct blkid_idinfo md_tp_idinfo =
+{
+ .name = "md",
+ .probefunc = probe_md_tp,
+ .magics = BLKID_NONE_MAGIC
+};
+