summaryrefslogtreecommitdiff
path: root/vendor/github.com/prometheus/procfs/mdstat.go
blob: 98e37aa8cafd02fefade81463bdb4323896e0804 (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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package procfs

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

var (
	statusLineRE   = regexp.MustCompile(`(\d+) blocks .*\[(\d+)/(\d+)\] \[[U_]+\]`)
	recoveryLineRE = 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 requires.
	DisksTotal int64
	// Number of failed disks.
	DisksFailed int64
	// Spare disks in the device.
	DisksSpare int64
	// Number of blocks the device holds.
	BlocksTotal int64
	// Number of blocks on the device that are in sync.
	BlocksSynced int64
}

// MDStat parses an mdstat-file (/proc/mdstat) and returns a slice of
// structs containing the relevant info.  More information available here:
// https://raid.wiki.kernel.org/index.php/Mdstat
func (fs FS) MDStat() ([]MDStat, error) {
	data, err := ioutil.ReadFile(fs.proc.Path("mdstat"))
	if err != nil {
		return nil, err
	}
	mdstat, err := parseMDStat(data)
	if err != nil {
		return nil, fmt.Errorf("error parsing mdstat %s: %s", fs.proc.Path("mdstat"), err)
	}
	return mdstat, nil
}

// parseMDStat parses data from mdstat file (/proc/mdstat) and returns a slice of
// structs containing the relevant info.
func parseMDStat(mdStatData []byte) ([]MDStat, error) {
	mdStats := []MDStat{}
	lines := strings.Split(string(mdStatData), "\n")

	for i, line := range lines {
		if strings.TrimSpace(line) == "" || line[0] == ' ' ||
			strings.HasPrefix(line, "Personalities") ||
			strings.HasPrefix(line, "unused") {
			continue
		}

		deviceFields := strings.Fields(line)
		if len(deviceFields) < 3 {
			return nil, fmt.Errorf("not enough fields in mdline (expected at least 3): %s", line)
		}
		mdName := deviceFields[0] // mdx
		state := deviceFields[2]  // active or inactive

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

		// Failed disks have the suffix (F) & Spare disks have the suffix (S).
		fail := int64(strings.Count(line, "(F)"))
		spare := int64(strings.Count(line, "(S)"))
		active, total, size, err := evalStatusLine(lines[i], lines[i+1])

		if err != nil {
			return nil, fmt.Errorf("error parsing md device lines: %s", err)
		}

		syncLineIdx := i + 2
		if strings.Contains(lines[i+2], "bitmap") { // skip bitmap line
			syncLineIdx++
		}

		// 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
		recovering := strings.Contains(lines[syncLineIdx], "recovery")
		resyncing := strings.Contains(lines[syncLineIdx], "resync")
		checking := strings.Contains(lines[syncLineIdx], "check")

		// Append recovery and resyncing state info.
		if recovering || resyncing || checking {
			if recovering {
				state = "recovering"
			} else if checking {
				state = "checking"
			} else {
				state = "resyncing"
			}

			// Handle case when resync=PENDING or resync=DELAYED.
			if strings.Contains(lines[syncLineIdx], "PENDING") ||
				strings.Contains(lines[syncLineIdx], "DELAYED") {
				syncedBlocks = 0
			} else {
				syncedBlocks, err = evalRecoveryLine(lines[syncLineIdx])
				if err != nil {
					return nil, fmt.Errorf("error parsing sync line in md device %s: %s", mdName, err)
				}
			}
		}

		mdStats = append(mdStats, MDStat{
			Name:          mdName,
			ActivityState: state,
			DisksActive:   active,
			DisksFailed:   fail,
			DisksSpare:    spare,
			DisksTotal:    total,
			BlocksTotal:   size,
			BlocksSynced:  syncedBlocks,
		})
	}

	return mdStats, nil
}

func evalStatusLine(deviceLine, statusLine string) (active, total, size int64, err error) {

	sizeStr := strings.Fields(statusLine)[0]
	size, err = strconv.ParseInt(sizeStr, 10, 64)
	if err != nil {
		return 0, 0, 0, fmt.Errorf("unexpected statusLine %s: %s", statusLine, err)
	}

	if strings.Contains(deviceLine, "raid0") || strings.Contains(deviceLine, "linear") {
		// In the device deviceLine, only disks have a number associated with them in [].
		total = int64(strings.Count(deviceLine, "["))
		return total, total, size, nil
	}

	if strings.Contains(deviceLine, "inactive") {
		return 0, 0, size, nil
	}

	matches := statusLineRE.FindStringSubmatch(statusLine)
	if len(matches) != 4 {
		return 0, 0, 0, fmt.Errorf("couldn't find all the substring matches: %s", statusLine)
	}

	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 evalRecoveryLine(recoveryLine string) (syncedBlocks int64, err error) {
	matches := recoveryLineRE.FindStringSubmatch(recoveryLine)
	if len(matches) != 2 {
		return 0, fmt.Errorf("unexpected recoveryLine: %s", recoveryLine)
	}

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

	return syncedBlocks, nil
}