summaryrefslogtreecommitdiff
path: root/vendor/github.com/prometheus/procfs/mdstat.go
blob: d7a248c0dfc4b823c2ef7456bf1dae0839e6aaf6 (plain)
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
package procfs

import (
	"fmt"
	"io/ioutil"
	"regexp"
	"strconv"
	"strings"
)

var (
	statuslineRE = regexp.MustCompile(`(\d+) blocks .*\[(\d+)/(\d+)\] \[[U_]+\]`)
	buildlineRE  = regexp.MustCompile(`\((\d+)/\d+\)`)
)

// MDStat holds info parsed from /proc/mdstat.
type MDStat struct {
	// Name of the device.
	Name string
	// activity-state of the device.
	ActivityState string
	// Number of active disks.
	DisksActive int64
	// Total number of disks the device consists of.
	DisksTotal int64
	// Number of blocks the device holds.
	BlocksTotal int64
	// Number of blocks on the device that are in sync.
	BlocksSynced int64
}

// ParseMDStat parses an mdstat-file and returns a struct with the relevant infos.
func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
	mdStatusFilePath := fs.Path("mdstat")
	content, err := ioutil.ReadFile(mdStatusFilePath)
	if err != nil {
		return []MDStat{}, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
	}

	mdStates := []MDStat{}
	lines := strings.Split(string(content), "\n")
	for i, l := range lines {
		if l == "" {
			continue
		}
		if l[0] == ' ' {
			continue
		}
		if strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
			continue
		}

		mainLine := strings.Split(l, " ")
		if len(mainLine) < 3 {
			return mdStates, fmt.Errorf("error parsing mdline: %s", l)
		}
		mdName := mainLine[0]
		activityState := mainLine[2]

		if len(lines) <= i+3 {
			return mdStates, fmt.Errorf(
				"error parsing %s: too few lines for md device %s",
				mdStatusFilePath,
				mdName,
			)
		}

		active, total, size, err := evalStatusline(lines[i+1])
		if err != nil {
			return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
		}

		// j is the line number of the syncing-line.
		j := i + 2
		if strings.Contains(lines[i+2], "bitmap") { // skip bitmap line
			j = i + 3
		}

		// If device is syncing at the moment, get the number of currently
		// synced bytes, otherwise that number equals the size of the device.
		syncedBlocks := size
		if strings.Contains(lines[j], "recovery") || strings.Contains(lines[j], "resync") {
			syncedBlocks, err = evalBuildline(lines[j])
			if err != nil {
				return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
			}
		}

		mdStates = append(mdStates, MDStat{
			Name:          mdName,
			ActivityState: activityState,
			DisksActive:   active,
			DisksTotal:    total,
			BlocksTotal:   size,
			BlocksSynced:  syncedBlocks,
		})
	}

	return mdStates, nil
}

func evalStatusline(statusline string) (active, total, size int64, err error) {
	matches := statuslineRE.FindStringSubmatch(statusline)
	if len(matches) != 4 {
		return 0, 0, 0, fmt.Errorf("unexpected statusline: %s", statusline)
	}

	size, err = strconv.ParseInt(matches[1], 10, 64)
	if err != nil {
		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
	}

	total, err = strconv.ParseInt(matches[2], 10, 64)
	if err != nil {
		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
	}

	active, err = strconv.ParseInt(matches[3], 10, 64)
	if err != nil {
		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
	}

	return active, total, size, nil
}

func evalBuildline(buildline string) (syncedBlocks int64, err error) {
	matches := buildlineRE.FindStringSubmatch(buildline)
	if len(matches) != 2 {
		return 0, fmt.Errorf("unexpected buildline: %s", buildline)
	}

	syncedBlocks, err = strconv.ParseInt(matches[1], 10, 64)
	if err != nil {
		return 0, fmt.Errorf("%s in buildline: %s", err, buildline)
	}

	return syncedBlocks, nil
}