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