1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/*
* 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 const struct topology_val {
/* /sys/dev/block/<maj>:<min>/<ATTR> */
const char * const attr;
/* functions to set probing result */
int (*set_ulong)(blkid_probe, unsigned long);
int (*set_int)(blkid_probe, int);
int (*set_u64)(blkid_probe, uint64_t);
} 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 },
{ "queue/dax", blkid_topology_set_dax },
{ "diskseq", .set_u64 = blkid_topology_set_diskseq },
};
static int probe_sysfs_tp(blkid_probe pr,
const struct blkid_idmag *mag __attribute__((__unused__)))
{
dev_t dev;
int rc, set_parent = 1;
struct path_cxt *pc;
size_t i, count = 0;
dev = blkid_probe_get_devno(pr);
if (!dev)
return 1;
pc = ul_new_sysfs_path(dev, NULL, NULL);
if (!pc)
return 1;
rc = 1; /* nothing (default) */
for (i = 0; i < ARRAY_SIZE(topology_vals); i++) {
const struct topology_val *val = &topology_vals[i];
int ok = ul_path_access(pc, F_OK, val->attr) == 0;
rc = 1; /* nothing */
if (!ok && set_parent) {
dev_t disk = blkid_probe_get_wholedisk_devno(pr);
set_parent = 0;
/*
* Read attributes from "disk" if the current device is
* a partition. Note that sysfs ul_path_* API is able
* to redirect requests to attributes if parent is set.
*/
if (disk && disk != dev) {
struct path_cxt *parent = ul_new_sysfs_path(disk, NULL, NULL);
if (!parent)
goto done;
sysfs_blkdev_set_parent(pc, parent);
ul_unref_path(parent);
/* try it again */
ok = ul_path_access(pc, F_OK, val->attr) == 0;
}
}
if (!ok)
continue; /* attribute does not exist */
if (val->set_ulong) {
uint64_t data;
if (ul_path_read_u64(pc, &data, val->attr) != 0)
continue;
rc = val->set_ulong(pr, (unsigned long) data);
} else if (val->set_int) {
int64_t data;
if (ul_path_read_s64(pc, &data, val->attr) != 0)
continue;
rc = val->set_int(pr, (int) data);
} else if (val->set_u64) {
uint64_t data;
if (ul_path_read_u64(pc, &data, val->attr) != 0)
continue;
rc = val->set_u64(pr, data);
}
if (rc < 0)
goto done; /* error */
if (rc == 0)
count++;
}
done:
ul_unref_path(pc); /* unref pc and 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
};
|