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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
#!perl -w
#
# ActiveBlockDevTab -- descriptors of all block devices in /sys
# Copyright (C) 2005 Erik van Konijnenburg
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#
use strict;
use warnings;
use Base;
use Conf;
use ActiveBlockDev;
package ActiveBlockDevTab;
my $abdTab = undef;
my $abdList = undef;
sub init () {
if (defined ($abdTab)) {
return;
}
$abdTab = {};
my $blockdir;
my $blockPath = Conf::get('sysFs') . "/block";
if (! opendir ($blockdir, "$blockPath")) {
Base::fatal ("can't open directory $blockPath");
}
while (defined (my $entry = readdir ($blockdir))) {
next if $entry eq ".";
next if $entry eq "..";
oneBlockDev($blockPath, $entry);
}
if (! closedir ($blockdir)) {
Base::fatal ("could not read directory $blockPath");
}
$abdList = [values %{$abdTab}];
}
sub oneBlockDev ($$) {
my ($blockPath, $entry) = @_;
my $devno = Base::getStringFile("$blockPath/$entry/dev");
if (exists ($abdTab->{$devno})) {
Base::fatal ("found duplicate devno in $blockPath/$entry");
}
my $hw = readlink("$blockPath/$entry/device");
# failure results in undef, which is exactly how
# we want to represent absence of a hw device.
if (defined ($hw)) {
unless ($hw =~ s!^(\.\./)+devices/!!) {
# imagine localised linux (/sys/geraete ...)
Base::fatal ("bad device link in $blockPath/$entry");
}
}
my $descr = ActiveBlockDev->new (
name => $entry,
devno => $devno,
parent => undef,
hw => $hw,
);
$abdTab->{$devno} = $descr;
#
# Scan partitions.
# Note that these are only visible after someone
# read the a block from the device.
#
my $devdir;
if (! opendir ($devdir, "$blockPath/$entry")) {
Base::fatal ("can't open directory $blockPath/$entry");
}
while (defined (my $partition = readdir ($devdir))) {
next if $partition eq ".";
next if $partition eq "..";
next unless -d "$blockPath/$entry/$partition";
# there can be subdirectories in a blockdev
# other than partitions; eg /sys/block/sda/queue.
# a partition has major:minor, so has a dev file.
next unless -f "$blockPath/$entry/$partition/dev";
onePartition($blockPath, $entry, $partition, $descr);
}
if (! closedir ($devdir)) {
Base::fatal ("could not read directory $blockPath/$entry");
}
}
sub onePartition ($$$$) {
my ($blockPath, $entry, $partition, $parent) = @_;
my $dev = Base::getStringFile("$blockPath/$entry/$partition/dev");
if (exists ($abdTab->{$dev})) {
Base::fatal ("found duplicate devno in $blockPath/$entry/$partition");
}
$abdTab->{$dev} = ActiveBlockDev->new (
name => $partition,
devno => $dev,
parent => $parent,
hw => undef,
);
}
#
# all -- return list of all known active block devices.
#
sub all () {
init;
return $abdList;
}
#
# findByDevno -- given devno in format maj:min,
# return corresponding descriptor or undef.
#
sub findByDevno ($) {
my ($devno) = @_;
init;
return $abdTab->{$devno};
}
#
# findByPath -- given path to block device file in /dev,
# return corresponding descriptor or undef.
#
sub findByPath ($) {
my ($path) = @_;
my $devno = Base::devno ($path);
if (! defined ($devno)) {
return undef;
}
return findByDevno ($devno);
}
1;
|
