1 files changed, 119 insertions, 0 deletions
diff --git a/libblkid/src/topology/sysfs.c b/libblkid/src/topology/sysfs.c
new file mode 100644
index 000000000..a04b20a37
--- /dev/null
+++ b/libblkid/src/topology/sysfs.c
@@ -0,0 +1,119 @@
+/*
+ * sysfs based topology -- gathers topology information from Linux sysfs
+ *
+ * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ *
+ * For more information see Linux kernel Documentation/ABI/testing/sysfs-block.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "sysfs.h"
+#include "topology.h"
+
+/*
+ * Sysfs topology values (since 2.6.31, May 2009).
+ */
+static struct topology_val {
+
+	/* /sys/dev/block/<maj>:<min>/<ATTR> */
+	const char *attr;
+
+	/* functions to set probing resut */
+	int (*set_ulong)(blkid_probe, unsigned long);
+	int (*set_int)(blkid_probe, int);
+
+} topology_vals[] = {
+	{ "alignment_offset", NULL, blkid_topology_set_alignment_offset },
+	{ "queue/minimum_io_size", blkid_topology_set_minimum_io_size },
+	{ "queue/optimal_io_size", blkid_topology_set_optimal_io_size },
+	{ "queue/physical_block_size", blkid_topology_set_physical_sector_size },
+};
+
+static int probe_sysfs_tp(blkid_probe pr,
+		const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+	dev_t dev, disk = 0;
+	int rc;
+	struct sysfs_cxt sysfs = UL_SYSFSCXT_EMPTY,
+			 parent = UL_SYSFSCXT_EMPTY;
+	size_t i, count = 0;
+
+	dev = blkid_probe_get_devno(pr);
+	if (!dev || sysfs_init(&sysfs, dev, NULL) != 0)
+		return 1;
+
+	rc = 1;		/* nothing (default) */
+
+	for (i = 0; i < ARRAY_SIZE(topology_vals); i++) {
+		struct topology_val *val = &topology_vals[i];
+		int ok = sysfs_has_attribute(&sysfs, val->attr);
+
+		rc = 1;	/* nothing */
+
+		if (!ok) {
+			if (!disk) {
+				/*
+				 * Read atrributes from "disk" if the current
+				 * device is a partition.
+				 */
+				disk = blkid_probe_get_wholedisk_devno(pr);
+				if (disk && disk != dev) {
+					if (sysfs_init(&parent, disk, NULL) != 0)
+						goto done;
+
+					sysfs.parent = &parent;
+					ok = sysfs_has_attribute(&sysfs,
+								 val->attr);
+				}
+			}
+			if (!ok)
+				continue;	/* attribute does not exist */
+		}
+
+		if (val->set_ulong) {
+			uint64_t data;
+
+			if (sysfs_read_u64(&sysfs, val->attr, &data) != 0)
+				continue;
+			rc = val->set_ulong(pr, (unsigned long) data);
+
+		} else if (val->set_int) {
+			int64_t data;
+
+			if (sysfs_read_s64(&sysfs, val->attr, &data) != 0)
+				continue;
+			rc = val->set_int(pr, (int) data);
+		}
+
+		if (rc < 0)
+			goto done;	/* error */
+		if (rc == 0)
+			count++;
+	}
+
+done:
+	sysfs_deinit(&sysfs);
+	sysfs_deinit(&parent);
+
+	if (count)
+		return 0;		/* success */
+	return rc;			/* error or nothing */
+}
+
+const struct blkid_idinfo sysfs_tp_idinfo =
+{
+	.name		= "sysfs",
+	.probefunc	= probe_sysfs_tp,
+	.magics		= BLKID_NONE_MAGIC
+};
+