Merge v1.2.1-master

Signed-off-by: Emile Vauge <emile@vauge.com>

vendor/github.com/prometheus/procfs/buddyinfo.go

@@ -0,0 +1,95 @@
+// Copyright 2017 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 (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// A BuddyInfo is the details parsed from /proc/buddyinfo.
+// The data is comprised of an array of free fragments of each size.
+// The sizes are 2^n*PAGE_SIZE, where n is the array index.
+type BuddyInfo struct {
+	Node  string
+	Zone  string
+	Sizes []float64
+}
+
+// NewBuddyInfo reads the buddyinfo statistics.
+func NewBuddyInfo() ([]BuddyInfo, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return nil, err
+	}
+
+	return fs.NewBuddyInfo()
+}
+
+// NewBuddyInfo reads the buddyinfo statistics from the specified `proc` filesystem.
+func (fs FS) NewBuddyInfo() ([]BuddyInfo, error) {
+	file, err := os.Open(fs.Path("buddyinfo"))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return parseBuddyInfo(file)
+}
+
+func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
+	var (
+		buddyInfo   = []BuddyInfo{}
+		scanner     = bufio.NewScanner(r)
+		bucketCount = -1
+	)
+
+	for scanner.Scan() {
+		var err error
+		line := scanner.Text()
+		parts := strings.Fields(string(line))
+
+		if len(parts) < 4 {
+			return nil, fmt.Errorf("invalid number of fields when parsing buddyinfo")
+		}
+
+		node := strings.TrimRight(parts[1], ",")
+		zone := strings.TrimRight(parts[3], ",")
+		arraySize := len(parts[4:])
+
+		if bucketCount == -1 {
+			bucketCount = arraySize
+		} else {
+			if bucketCount != arraySize {
+				return nil, fmt.Errorf("mismatch in number of buddyinfo buckets, previous count %d, new count %d", bucketCount, arraySize)
+			}
+		}
+
+		sizes := make([]float64, arraySize)
+		for i := 0; i < arraySize; i++ {
+			sizes[i], err = strconv.ParseFloat(parts[i+4], 64)
+			if err != nil {
+				return nil, fmt.Errorf("invalid value in buddyinfo: %s", err)
+			}
+		}
+
+		buddyInfo = append(buddyInfo, BuddyInfo{node, zone, sizes})
+	}
+
+	return buddyInfo, scanner.Err()
+}

vendor/github.com/prometheus/procfs/fs.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"path"
+
+	"github.com/prometheus/procfs/xfs"
 )
 
 // FS represents the pseudo-filesystem proc, which provides an interface to
@@ -27,14 +29,18 @@ func NewFS(mountPoint string) (FS, error) {
 	return FS(mountPoint), nil
 }
 
-func (fs FS) stat(p string) (os.FileInfo, error) {
-	return os.Stat(path.Join(string(fs), p))
+// Path returns the path of the given subsystem relative to the procfs root.
+func (fs FS) Path(p ...string) string {
+	return path.Join(append([]string{string(fs)}, p...)...)
 }
 
-func (fs FS) open(p string) (*os.File, error) {
-	return os.Open(path.Join(string(fs), p))
-}
+// XFSStats retrieves XFS filesystem runtime statistics.
+func (fs FS) XFSStats() (*xfs.Stats, error) {
+	f, err := os.Open(fs.Path("fs/xfs/stat"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
 
-func (fs FS) readlink(p string) (string, error) {
-	return os.Readlink(path.Join(string(fs), p))
+	return xfs.ParseStats(f)
 }

vendor/github.com/prometheus/procfs/ipvs.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"io/ioutil"
 	"net"
+	"os"
 	"strconv"
 	"strings"
 )
@@ -58,7 +59,7 @@ func NewIPVSStats() (IPVSStats, error) {
 
 // NewIPVSStats reads the IPVS statistics from the specified `proc` filesystem.
 func (fs FS) NewIPVSStats() (IPVSStats, error) {
-	file, err := fs.open("net/ip_vs_stats")
+	file, err := os.Open(fs.Path("net/ip_vs_stats"))
 	if err != nil {
 		return IPVSStats{}, err
 	}
@@ -127,7 +128,7 @@ func NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
 
 // NewIPVSBackendStatus reads and returns the status of all (virtual,real) server pairs from the specified `proc` filesystem.
 func (fs FS) NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
-	file, err := fs.open("net/ip_vs")
+	file, err := os.Open(fs.Path("net/ip_vs"))
 	if err != nil {
 		return nil, err
 	}

vendor/github.com/prometheus/procfs/mdstat.go

@@ -3,7 +3,6 @@ package procfs
 import (
 	"fmt"
 	"io/ioutil"
-	"path"
 	"regexp"
 	"strconv"
 	"strings"
@@ -32,36 +31,22 @@ type MDStat struct {
 
 // ParseMDStat parses an mdstat-file and returns a struct with the relevant infos.
 func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
-	mdStatusFilePath := path.Join(string(fs), "mdstat")
+	mdStatusFilePath := fs.Path("mdstat")
 	content, err := ioutil.ReadFile(mdStatusFilePath)
 	if err != nil {
 		return []MDStat{}, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
 	}
 
-	mdStatusFile := string(content)
-
-	lines := strings.Split(mdStatusFile, "\n")
-	var currentMD string
-
-	// Each md has at least the deviceline, statusline and one empty line afterwards
-	// so we will have probably something of the order len(lines)/3 devices
-	// so we use that for preallocation.
-	estimateMDs := len(lines) / 3
-	mdStates := make([]MDStat, 0, estimateMDs)
-
+	mdStates := []MDStat{}
+	lines := strings.Split(string(content), "\n")
 	for i, l := range lines {
 		if l == "" {
-			// Skip entirely empty lines.
 			continue
 		}
-
 		if l[0] == ' ' {
-			// Those lines are not the beginning of a md-section.
 			continue
 		}
-
 		if strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
-			// We aren't interested in lines with general info.
 			continue
 		}
 
@@ -69,32 +54,30 @@ func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
 		if len(mainLine) < 3 {
 			return mdStates, fmt.Errorf("error parsing mdline: %s", l)
 		}
-		currentMD = mainLine[0]      // name of md-device
-		activityState := mainLine[2] // activity status of said md-device
+		mdName := mainLine[0]
+		activityState := mainLine[2]
 
 		if len(lines) <= i+3 {
-			return mdStates, fmt.Errorf("error parsing %s: entry for %s has fewer lines than expected", mdStatusFilePath, currentMD)
+			return mdStates, fmt.Errorf(
+				"error parsing %s: too few lines for md device %s",
+				mdStatusFilePath,
+				mdName,
+			)
 		}
 
-		active, total, size, err := evalStatusline(lines[i+1]) // parse statusline, always present
+		active, total, size, err := evalStatusline(lines[i+1])
 		if err != nil {
 			return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
 		}
 
-		//
-		// Now get the number of synced blocks.
-		//
-
-		// Get the line number of the syncing-line.
-		var j int
-		if strings.Contains(lines[i+2], "bitmap") { // then skip the bitmap line
+		// 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
-		} else {
-			j = i + 2
 		}
 
-		// If device is syncing at the moment, get the number of currently synced bytes,
-		// otherwise that number equals the size of the device.
+		// 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])
@@ -103,8 +86,14 @@ func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
 			}
 		}
 
-		mdStates = append(mdStates, MDStat{currentMD, activityState, active, total, size, syncedBlocks})
-
+		mdStates = append(mdStates, MDStat{
+			Name:          mdName,
+			ActivityState: activityState,
+			DisksActive:   active,
+			DisksTotal:    total,
+			BlocksTotal:   size,
+			BlocksSynced:  syncedBlocks,
+		})
 	}
 
 	return mdStates, nil
@@ -112,47 +101,38 @@ func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
 
 func evalStatusline(statusline string) (active, total, size int64, err error) {
 	matches := statuslineRE.FindStringSubmatch(statusline)
-
-	// +1 to make it more obvious that the whole string containing the info is also returned as matches[0].
-	if len(matches) != 3+1 {
-		return 0, 0, 0, fmt.Errorf("unexpected number matches found in statusline: %s", 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("%s in statusline: %s", err, statusline)
+		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("%s in statusline: %s", err, statusline)
+		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("%s in statusline: %s", err, statusline)
+		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
 	}
 
 	return active, total, size, nil
 }
 
-// Gets the size that has already been synced out of the sync-line.
-func evalBuildline(buildline string) (int64, error) {
+func evalBuildline(buildline string) (syncedBlocks int64, err error) {
 	matches := buildlineRE.FindStringSubmatch(buildline)
-
-	// +1 to make it more obvious that the whole string containing the info is also returned as matches[0].
-	if len(matches) < 1+1 {
-		return 0, fmt.Errorf("too few matches found in buildline: %s", buildline)
+	if len(matches) != 2 {
+		return 0, fmt.Errorf("unexpected buildline: %s", buildline)
 	}
 
-	if len(matches) > 1+1 {
-		return 0, fmt.Errorf("too many matches found in buildline: %s", buildline)
-	}
-
-	syncedSize, err := strconv.ParseInt(matches[1], 10, 64)
+	syncedBlocks, err = strconv.ParseInt(matches[1], 10, 64)
 	if err != nil {
 		return 0, fmt.Errorf("%s in buildline: %s", err, buildline)
 	}
 
-	return syncedSize, nil
+	return syncedBlocks, nil
 }

vendor/github.com/prometheus/procfs/mountstats.go

@@ -0,0 +1,552 @@
+package procfs
+
+// While implementing parsing of /proc/[pid]/mountstats, this blog was used
+// heavily as a reference:
+//   https://utcc.utoronto.ca/~cks/space/blog/linux/NFSMountstatsIndex
+//
+// Special thanks to Chris Siebenmann for all of his posts explaining the
+// various statistics available for NFS.
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Constants shared between multiple functions.
+const (
+	deviceEntryLen = 8
+
+	fieldBytesLen  = 8
+	fieldEventsLen = 27
+
+	statVersion10 = "1.0"
+	statVersion11 = "1.1"
+
+	fieldTransport10Len = 10
+	fieldTransport11Len = 13
+)
+
+// A Mount is a device mount parsed from /proc/[pid]/mountstats.
+type Mount struct {
+	// Name of the device.
+	Device string
+	// The mount point of the device.
+	Mount string
+	// The filesystem type used by the device.
+	Type string
+	// If available additional statistics related to this Mount.
+	// Use a type assertion to determine if additional statistics are available.
+	Stats MountStats
+}
+
+// A MountStats is a type which contains detailed statistics for a specific
+// type of Mount.
+type MountStats interface {
+	mountStats()
+}
+
+// A MountStatsNFS is a MountStats implementation for NFSv3 and v4 mounts.
+type MountStatsNFS struct {
+	// The version of statistics provided.
+	StatVersion string
+	// The age of the NFS mount.
+	Age time.Duration
+	// Statistics related to byte counters for various operations.
+	Bytes NFSBytesStats
+	// Statistics related to various NFS event occurrences.
+	Events NFSEventsStats
+	// Statistics broken down by filesystem operation.
+	Operations []NFSOperationStats
+	// Statistics about the NFS RPC transport.
+	Transport NFSTransportStats
+}
+
+// mountStats implements MountStats.
+func (m MountStatsNFS) mountStats() {}
+
+// A NFSBytesStats contains statistics about the number of bytes read and written
+// by an NFS client to and from an NFS server.
+type NFSBytesStats struct {
+	// Number of bytes read using the read() syscall.
+	Read uint64
+	// Number of bytes written using the write() syscall.
+	Write uint64
+	// Number of bytes read using the read() syscall in O_DIRECT mode.
+	DirectRead uint64
+	// Number of bytes written using the write() syscall in O_DIRECT mode.
+	DirectWrite uint64
+	// Number of bytes read from the NFS server, in total.
+	ReadTotal uint64
+	// Number of bytes written to the NFS server, in total.
+	WriteTotal uint64
+	// Number of pages read directly via mmap()'d files.
+	ReadPages uint64
+	// Number of pages written directly via mmap()'d files.
+	WritePages uint64
+}
+
+// A NFSEventsStats contains statistics about NFS event occurrences.
+type NFSEventsStats struct {
+	// Number of times cached inode attributes are re-validated from the server.
+	InodeRevalidate uint64
+	// Number of times cached dentry nodes are re-validated from the server.
+	DnodeRevalidate uint64
+	// Number of times an inode cache is cleared.
+	DataInvalidate uint64
+	// Number of times cached inode attributes are invalidated.
+	AttributeInvalidate uint64
+	// Number of times files or directories have been open()'d.
+	VFSOpen uint64
+	// Number of times a directory lookup has occurred.
+	VFSLookup uint64
+	// Number of times permissions have been checked.
+	VFSAccess uint64
+	// Number of updates (and potential writes) to pages.
+	VFSUpdatePage uint64
+	// Number of pages read directly via mmap()'d files.
+	VFSReadPage uint64
+	// Number of times a group of pages have been read.
+	VFSReadPages uint64
+	// Number of pages written directly via mmap()'d files.
+	VFSWritePage uint64
+	// Number of times a group of pages have been written.
+	VFSWritePages uint64
+	// Number of times directory entries have been read with getdents().
+	VFSGetdents uint64
+	// Number of times attributes have been set on inodes.
+	VFSSetattr uint64
+	// Number of pending writes that have been forcefully flushed to the server.
+	VFSFlush uint64
+	// Number of times fsync() has been called on directories and files.
+	VFSFsync uint64
+	// Number of times locking has been attempted on a file.
+	VFSLock uint64
+	// Number of times files have been closed and released.
+	VFSFileRelease uint64
+	// Unknown.  Possibly unused.
+	CongestionWait uint64
+	// Number of times files have been truncated.
+	Truncation uint64
+	// Number of times a file has been grown due to writes beyond its existing end.
+	WriteExtension uint64
+	// Number of times a file was removed while still open by another process.
+	SillyRename uint64
+	// Number of times the NFS server gave less data than expected while reading.
+	ShortRead uint64
+	// Number of times the NFS server wrote less data than expected while writing.
+	ShortWrite uint64
+	// Number of times the NFS server indicated EJUKEBOX; retrieving data from
+	// offline storage.
+	JukeboxDelay uint64
+	// Number of NFS v4.1+ pNFS reads.
+	PNFSRead uint64
+	// Number of NFS v4.1+ pNFS writes.
+	PNFSWrite uint64
+}
+
+// A NFSOperationStats contains statistics for a single operation.
+type NFSOperationStats struct {
+	// The name of the operation.
+	Operation string
+	// Number of requests performed for this operation.
+	Requests uint64
+	// Number of times an actual RPC request has been transmitted for this operation.
+	Transmissions uint64
+	// Number of times a request has had a major timeout.
+	MajorTimeouts uint64
+	// Number of bytes sent for this operation, including RPC headers and payload.
+	BytesSent uint64
+	// Number of bytes received for this operation, including RPC headers and payload.
+	BytesReceived uint64
+	// Duration all requests spent queued for transmission before they were sent.
+	CumulativeQueueTime time.Duration
+	// Duration it took to get a reply back after the request was transmitted.
+	CumulativeTotalResponseTime time.Duration
+	// Duration from when a request was enqueued to when it was completely handled.
+	CumulativeTotalRequestTime time.Duration
+}
+
+// A NFSTransportStats contains statistics for the NFS mount RPC requests and
+// responses.
+type NFSTransportStats struct {
+	// The local port used for the NFS mount.
+	Port uint64
+	// Number of times the client has had to establish a connection from scratch
+	// to the NFS server.
+	Bind uint64
+	// Number of times the client has made a TCP connection to the NFS server.
+	Connect uint64
+	// Duration (in jiffies, a kernel internal unit of time) the NFS mount has
+	// spent waiting for connections to the server to be established.
+	ConnectIdleTime uint64
+	// Duration since the NFS mount last saw any RPC traffic.
+	IdleTime time.Duration
+	// Number of RPC requests for this mount sent to the NFS server.
+	Sends uint64
+	// Number of RPC responses for this mount received from the NFS server.
+	Receives uint64
+	// Number of times the NFS server sent a response with a transaction ID
+	// unknown to this client.
+	BadTransactionIDs uint64
+	// A running counter, incremented on each request as the current difference
+	// ebetween sends and receives.
+	CumulativeActiveRequests uint64
+	// A running counter, incremented on each request by the current backlog
+	// queue size.
+	CumulativeBacklog uint64
+
+	// Stats below only available with stat version 1.1.
+
+	// Maximum number of simultaneously active RPC requests ever used.
+	MaximumRPCSlotsUsed uint64
+	// A running counter, incremented on each request as the current size of the
+	// sending queue.
+	CumulativeSendingQueue uint64
+	// A running counter, incremented on each request as the current size of the
+	// pending queue.
+	CumulativePendingQueue uint64
+}
+
+// parseMountStats parses a /proc/[pid]/mountstats file and returns a slice
+// of Mount structures containing detailed information about each mount.
+// If available, statistics for each mount are parsed as well.
+func parseMountStats(r io.Reader) ([]*Mount, error) {
+	const (
+		device            = "device"
+		statVersionPrefix = "statvers="
+
+		nfs3Type = "nfs"
+		nfs4Type = "nfs4"
+	)
+
+	var mounts []*Mount
+
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		// Only look for device entries in this function
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) == 0 || ss[0] != device {
+			continue
+		}
+
+		m, err := parseMount(ss)
+		if err != nil {
+			return nil, err
+		}
+
+		// Does this mount also possess statistics information?
+		if len(ss) > deviceEntryLen {
+			// Only NFSv3 and v4 are supported for parsing statistics
+			if m.Type != nfs3Type && m.Type != nfs4Type {
+				return nil, fmt.Errorf("cannot parse MountStats for fstype %q", m.Type)
+			}
+
+			statVersion := strings.TrimPrefix(ss[8], statVersionPrefix)
+
+			stats, err := parseMountStatsNFS(s, statVersion)
+			if err != nil {
+				return nil, err
+			}
+
+			m.Stats = stats
+		}
+
+		mounts = append(mounts, m)
+	}
+
+	return mounts, s.Err()
+}
+
+// parseMount parses an entry in /proc/[pid]/mountstats in the format:
+//   device [device] mounted on [mount] with fstype [type]
+func parseMount(ss []string) (*Mount, error) {
+	if len(ss) < deviceEntryLen {
+		return nil, fmt.Errorf("invalid device entry: %v", ss)
+	}
+
+	// Check for specific words appearing at specific indices to ensure
+	// the format is consistent with what we expect
+	format := []struct {
+		i int
+		s string
+	}{
+		{i: 0, s: "device"},
+		{i: 2, s: "mounted"},
+		{i: 3, s: "on"},
+		{i: 5, s: "with"},
+		{i: 6, s: "fstype"},
+	}
+
+	for _, f := range format {
+		if ss[f.i] != f.s {
+			return nil, fmt.Errorf("invalid device entry: %v", ss)
+		}
+	}
+
+	return &Mount{
+		Device: ss[1],
+		Mount:  ss[4],
+		Type:   ss[7],
+	}, nil
+}
+
+// parseMountStatsNFS parses a MountStatsNFS by scanning additional information
+// related to NFS statistics.
+func parseMountStatsNFS(s *bufio.Scanner, statVersion string) (*MountStatsNFS, error) {
+	// Field indicators for parsing specific types of data
+	const (
+		fieldAge        = "age:"
+		fieldBytes      = "bytes:"
+		fieldEvents     = "events:"
+		fieldPerOpStats = "per-op"
+		fieldTransport  = "xprt:"
+	)
+
+	stats := &MountStatsNFS{
+		StatVersion: statVersion,
+	}
+
+	for s.Scan() {
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) == 0 {
+			break
+		}
+		if len(ss) < 2 {
+			return nil, fmt.Errorf("not enough information for NFS stats: %v", ss)
+		}
+
+		switch ss[0] {
+		case fieldAge:
+			// Age integer is in seconds
+			d, err := time.ParseDuration(ss[1] + "s")
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Age = d
+		case fieldBytes:
+			bstats, err := parseNFSBytesStats(ss[1:])
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Bytes = *bstats
+		case fieldEvents:
+			estats, err := parseNFSEventsStats(ss[1:])
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Events = *estats
+		case fieldTransport:
+			if len(ss) < 3 {
+				return nil, fmt.Errorf("not enough information for NFS transport stats: %v", ss)
+			}
+
+			tstats, err := parseNFSTransportStats(ss[2:], statVersion)
+			if err != nil {
+				return nil, err
+			}
+
+			stats.Transport = *tstats
+		}
+
+		// When encountering "per-operation statistics", we must break this
+		// loop and parse them separately to ensure we can terminate parsing
+		// before reaching another device entry; hence why this 'if' statement
+		// is not just another switch case
+		if ss[0] == fieldPerOpStats {
+			break
+		}
+	}
+
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	// NFS per-operation stats appear last before the next device entry
+	perOpStats, err := parseNFSOperationStats(s)
+	if err != nil {
+		return nil, err
+	}
+
+	stats.Operations = perOpStats
+
+	return stats, nil
+}
+
+// parseNFSBytesStats parses a NFSBytesStats line using an input set of
+// integer fields.
+func parseNFSBytesStats(ss []string) (*NFSBytesStats, error) {
+	if len(ss) != fieldBytesLen {
+		return nil, fmt.Errorf("invalid NFS bytes stats: %v", ss)
+	}
+
+	ns := make([]uint64, 0, fieldBytesLen)
+	for _, s := range ss {
+		n, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		ns = append(ns, n)
+	}
+
+	return &NFSBytesStats{
+		Read:        ns[0],
+		Write:       ns[1],
+		DirectRead:  ns[2],
+		DirectWrite: ns[3],
+		ReadTotal:   ns[4],
+		WriteTotal:  ns[5],
+		ReadPages:   ns[6],
+		WritePages:  ns[7],
+	}, nil
+}
+
+// parseNFSEventsStats parses a NFSEventsStats line using an input set of
+// integer fields.
+func parseNFSEventsStats(ss []string) (*NFSEventsStats, error) {
+	if len(ss) != fieldEventsLen {
+		return nil, fmt.Errorf("invalid NFS events stats: %v", ss)
+	}
+
+	ns := make([]uint64, 0, fieldEventsLen)
+	for _, s := range ss {
+		n, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		ns = append(ns, n)
+	}
+
+	return &NFSEventsStats{
+		InodeRevalidate:     ns[0],
+		DnodeRevalidate:     ns[1],
+		DataInvalidate:      ns[2],
+		AttributeInvalidate: ns[3],
+		VFSOpen:             ns[4],
+		VFSLookup:           ns[5],
+		VFSAccess:           ns[6],
+		VFSUpdatePage:       ns[7],
+		VFSReadPage:         ns[8],
+		VFSReadPages:        ns[9],
+		VFSWritePage:        ns[10],
+		VFSWritePages:       ns[11],
+		VFSGetdents:         ns[12],
+		VFSSetattr:          ns[13],
+		VFSFlush:            ns[14],
+		VFSFsync:            ns[15],
+		VFSLock:             ns[16],
+		VFSFileRelease:      ns[17],
+		CongestionWait:      ns[18],
+		Truncation:          ns[19],
+		WriteExtension:      ns[20],
+		SillyRename:         ns[21],
+		ShortRead:           ns[22],
+		ShortWrite:          ns[23],
+		JukeboxDelay:        ns[24],
+		PNFSRead:            ns[25],
+		PNFSWrite:           ns[26],
+	}, nil
+}
+
+// parseNFSOperationStats parses a slice of NFSOperationStats by scanning
+// additional information about per-operation statistics until an empty
+// line is reached.
+func parseNFSOperationStats(s *bufio.Scanner) ([]NFSOperationStats, error) {
+	const (
+		// Number of expected fields in each per-operation statistics set
+		numFields = 9
+	)
+
+	var ops []NFSOperationStats
+
+	for s.Scan() {
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) == 0 {
+			// Must break when reading a blank line after per-operation stats to
+			// enable top-level function to parse the next device entry
+			break
+		}
+
+		if len(ss) != numFields {
+			return nil, fmt.Errorf("invalid NFS per-operations stats: %v", ss)
+		}
+
+		// Skip string operation name for integers
+		ns := make([]uint64, 0, numFields-1)
+		for _, st := range ss[1:] {
+			n, err := strconv.ParseUint(st, 10, 64)
+			if err != nil {
+				return nil, err
+			}
+
+			ns = append(ns, n)
+		}
+
+		ops = append(ops, NFSOperationStats{
+			Operation:                   strings.TrimSuffix(ss[0], ":"),
+			Requests:                    ns[0],
+			Transmissions:               ns[1],
+			MajorTimeouts:               ns[2],
+			BytesSent:                   ns[3],
+			BytesReceived:               ns[4],
+			CumulativeQueueTime:         time.Duration(ns[5]) * time.Millisecond,
+			CumulativeTotalResponseTime: time.Duration(ns[6]) * time.Millisecond,
+			CumulativeTotalRequestTime:  time.Duration(ns[7]) * time.Millisecond,
+		})
+	}
+
+	return ops, s.Err()
+}
+
+// parseNFSTransportStats parses a NFSTransportStats line using an input set of
+// integer fields matched to a specific stats version.
+func parseNFSTransportStats(ss []string, statVersion string) (*NFSTransportStats, error) {
+	switch statVersion {
+	case statVersion10:
+		if len(ss) != fieldTransport10Len {
+			return nil, fmt.Errorf("invalid NFS transport stats 1.0 statement: %v", ss)
+		}
+	case statVersion11:
+		if len(ss) != fieldTransport11Len {
+			return nil, fmt.Errorf("invalid NFS transport stats 1.1 statement: %v", ss)
+		}
+	default:
+		return nil, fmt.Errorf("unrecognized NFS transport stats version: %q", statVersion)
+	}
+
+	// Allocate enough for v1.1 stats since zero value for v1.1 stats will be okay
+	// in a v1.0 response
+	ns := make([]uint64, 0, fieldTransport11Len)
+	for _, s := range ss {
+		n, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		ns = append(ns, n)
+	}
+
+	return &NFSTransportStats{
+		Port:                     ns[0],
+		Bind:                     ns[1],
+		Connect:                  ns[2],
+		ConnectIdleTime:          ns[3],
+		IdleTime:                 time.Duration(ns[4]) * time.Second,
+		Sends:                    ns[5],
+		Receives:                 ns[6],
+		BadTransactionIDs:        ns[7],
+		CumulativeActiveRequests: ns[8],
+		CumulativeBacklog:        ns[9],
+		MaximumRPCSlotsUsed:      ns[10],
+		CumulativeSendingQueue:   ns[11],
+		CumulativePendingQueue:   ns[12],
+	}, nil
+}

vendor/github.com/prometheus/procfs/proc.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"path"
 	"strconv"
 	"strings"
 )
@@ -42,7 +41,7 @@ func NewProc(pid int) (Proc, error) {
 	return fs.NewProc(pid)
 }
 
-// AllProcs returns a list of all currently avaible processes under /proc.
+// AllProcs returns a list of all currently available processes under /proc.
 func AllProcs() (Procs, error) {
 	fs, err := NewFS(DefaultMountPoint)
 	if err != nil {
@@ -53,7 +52,7 @@ func AllProcs() (Procs, error) {
 
 // Self returns a process for the current process.
 func (fs FS) Self() (Proc, error) {
-	p, err := fs.readlink("self")
+	p, err := os.Readlink(fs.Path("self"))
 	if err != nil {
 		return Proc{}, err
 	}
@@ -66,15 +65,15 @@ func (fs FS) Self() (Proc, error) {
 
 // NewProc returns a process for the given pid.
 func (fs FS) NewProc(pid int) (Proc, error) {
-	if _, err := fs.stat(strconv.Itoa(pid)); err != nil {
+	if _, err := os.Stat(fs.Path(strconv.Itoa(pid))); err != nil {
 		return Proc{}, err
 	}
 	return Proc{PID: pid, fs: fs}, nil
 }
 
-// AllProcs returns a list of all currently avaible processes.
+// AllProcs returns a list of all currently available processes.
 func (fs FS) AllProcs() (Procs, error) {
-	d, err := fs.open("")
+	d, err := os.Open(fs.Path())
 	if err != nil {
 		return Procs{}, err
 	}
@@ -99,7 +98,7 @@ func (fs FS) AllProcs() (Procs, error) {
 
 // CmdLine returns the command line of a process.
 func (p Proc) CmdLine() ([]string, error) {
-	f, err := p.open("cmdline")
+	f, err := os.Open(p.path("cmdline"))
 	if err != nil {
 		return nil, err
 	}
@@ -117,10 +116,25 @@ func (p Proc) CmdLine() ([]string, error) {
 	return strings.Split(string(data[:len(data)-1]), string(byte(0))), nil
 }
 
+// Comm returns the command name of a process.
+func (p Proc) Comm() (string, error) {
+	f, err := os.Open(p.path("comm"))
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return "", err
+	}
+
+	return strings.TrimSpace(string(data)), nil
+}
+
 // Executable returns the absolute path of the executable command of a process.
 func (p Proc) Executable() (string, error) {
-	exe, err := p.readlink("exe")
-
+	exe, err := os.Readlink(p.path("exe"))
 	if os.IsNotExist(err) {
 		return "", nil
 	}
@@ -158,7 +172,7 @@ func (p Proc) FileDescriptorTargets() ([]string, error) {
 	targets := make([]string, len(names))
 
 	for i, name := range names {
-		target, err := p.readlink("fd/" + name)
+		target, err := os.Readlink(p.path("fd", name))
 		if err == nil {
 			targets[i] = target
 		}
@@ -178,8 +192,20 @@ func (p Proc) FileDescriptorsLen() (int, error) {
 	return len(fds), nil
 }
 
+// MountStats retrieves statistics and configuration for mount points in a
+// process's namespace.
+func (p Proc) MountStats() ([]*Mount, error) {
+	f, err := os.Open(p.path("mountstats"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return parseMountStats(f)
+}
+
 func (p Proc) fileDescriptors() ([]string, error) {
-	d, err := p.open("fd")
+	d, err := os.Open(p.path("fd"))
 	if err != nil {
 		return nil, err
 	}
@@ -193,10 +219,6 @@ func (p Proc) fileDescriptors() ([]string, error) {
 	return names, nil
 }
 
-func (p Proc) open(pa string) (*os.File, error) {
-	return p.fs.open(path.Join(strconv.Itoa(p.PID), pa))
-}
-
-func (p Proc) readlink(pa string) (string, error) {
-	return p.fs.readlink(path.Join(strconv.Itoa(p.PID), pa))
+func (p Proc) path(pa ...string) string {
+	return p.fs.Path(append([]string{strconv.Itoa(p.PID)}, pa...)...)
 }

vendor/github.com/prometheus/procfs/proc_io.go

@@ -3,6 +3,7 @@ package procfs
 import (
 	"fmt"
 	"io/ioutil"
+	"os"
 )
 
 // ProcIO models the content of /proc/<pid>/io.
@@ -29,7 +30,7 @@ type ProcIO struct {
 func (p Proc) NewIO() (ProcIO, error) {
 	pio := ProcIO{}
 
-	f, err := p.open("io")
+	f, err := os.Open(p.path("io"))
 	if err != nil {
 		return pio, err
 	}

vendor/github.com/prometheus/procfs/proc_limits.go

@@ -3,29 +3,56 @@ package procfs
 import (
 	"bufio"
 	"fmt"
+	"os"
 	"regexp"
 	"strconv"
 )
 
 // ProcLimits represents the soft limits for each of the process's resource
-// limits.
+// limits. For more information see getrlimit(2):
+// http://man7.org/linux/man-pages/man2/getrlimit.2.html.
 type ProcLimits struct {
-	CPUTime          int
-	FileSize         int
-	DataSize         int
-	StackSize        int
-	CoreFileSize     int
-	ResidentSet      int
-	Processes        int
-	OpenFiles        int
-	LockedMemory     int
-	AddressSpace     int
-	FileLocks        int
-	PendingSignals   int
-	MsqqueueSize     int
-	NicePriority     int
+	// CPU time limit in seconds.
+	CPUTime int
+	// Maximum size of files that the process may create.
+	FileSize int
+	// Maximum size of the process's data segment (initialized data,
+	// uninitialized data, and heap).
+	DataSize int
+	// Maximum size of the process stack in bytes.
+	StackSize int
+	// Maximum size of a core file.
+	CoreFileSize int
+	// Limit of the process's resident set in pages.
+	ResidentSet int
+	// Maximum number of processes that can be created for the real user ID of
+	// the calling process.
+	Processes int
+	// Value one greater than the maximum file descriptor number that can be
+	// opened by this process.
+	OpenFiles int
+	// Maximum number of bytes of memory that may be locked into RAM.
+	LockedMemory int
+	// Maximum size of the process's virtual memory address space in bytes.
+	AddressSpace int
+	// Limit on the combined number of flock(2) locks and fcntl(2) leases that
+	// this process may establish.
+	FileLocks int
+	// Limit of signals that may be queued for the real user ID of the calling
+	// process.
+	PendingSignals int
+	// Limit on the number of bytes that can be allocated for POSIX message
+	// queues for the real user ID of the calling process.
+	MsqqueueSize int
+	// Limit of the nice priority set using setpriority(2) or nice(2).
+	NicePriority int
+	// Limit of the real-time priority set using sched_setscheduler(2) or
+	// sched_setparam(2).
 	RealtimePriority int
-	RealtimeTimeout  int
+	// Limit (in microseconds) on the amount of CPU time that a process
+	// scheduled under a real-time scheduling policy may consume without making
+	// a blocking system call.
+	RealtimeTimeout int
 }
 
 const (
@@ -39,7 +66,7 @@ var (
 
 // NewLimits returns the current soft limits of the process.
 func (p Proc) NewLimits() (ProcLimits, error) {
-	f, err := p.open("limits")
+	f, err := os.Open(p.path("limits"))
 	if err != nil {
 		return ProcLimits{}, err
 	}
@@ -60,7 +87,7 @@ func (p Proc) NewLimits() (ProcLimits, error) {
 		case "Max cpu time":
 			l.CPUTime, err = parseInt(fields[1])
 		case "Max file size":
-			l.FileLocks, err = parseInt(fields[1])
+			l.FileSize, err = parseInt(fields[1])
 		case "Max data size":
 			l.DataSize, err = parseInt(fields[1])
 		case "Max stack size":
@@ -90,7 +117,6 @@ func (p Proc) NewLimits() (ProcLimits, error) {
 		case "Max realtime timeout":
 			l.RealtimeTimeout, err = parseInt(fields[1])
 		}
-
 		if err != nil {
 			return ProcLimits{}, err
 		}

vendor/github.com/prometheus/procfs/proc_stat.go

@@ -7,15 +7,15 @@ import (
 	"os"
 )
 
-// Originally, this USER_HZ value was dynamically retrieved via a sysconf call which
-// required cgo. However, that caused a lot of problems regarding
+// Originally, this USER_HZ value was dynamically retrieved via a sysconf call
+// which required cgo. However, that caused a lot of problems regarding
 // cross-compilation. Alternatives such as running a binary to determine the
-// value, or trying to derive it in some other way were all problematic.
-// After much research it was determined that USER_HZ is actually hardcoded to
-// 100 on all Go-supported platforms as of the time of this writing. This is
-// why we decided to hardcode it here as well. It is not impossible that there
-// could be systems with exceptions, but they should be very exotic edge cases,
-// and in that case, the worst outcome will be two misreported metrics.
+// value, or trying to derive it in some other way were all problematic.  After
+// much research it was determined that USER_HZ is actually hardcoded to 100 on
+// all Go-supported platforms as of the time of this writing. This is why we
+// decided to hardcode it here as well. It is not impossible that there could
+// be systems with exceptions, but they should be very exotic edge cases, and
+// in that case, the worst outcome will be two misreported metrics.
 //
 // See also the following discussions:
 //
@@ -91,7 +91,7 @@ type ProcStat struct {
 
 // NewStat returns the current status information of the process.
 func (p Proc) NewStat() (ProcStat, error) {
-	f, err := p.open("stat")
+	f, err := os.Open(p.path("stat"))
 	if err != nil {
 		return ProcStat{}, err
 	}

vendor/github.com/prometheus/procfs/stat.go

@@ -3,6 +3,7 @@ package procfs
 import (
 	"bufio"
 	"fmt"
+	"os"
 	"strconv"
 	"strings"
 )
@@ -25,7 +26,7 @@ func NewStat() (Stat, error) {
 
 // NewStat returns an information about current kernel/system statistics.
 func (fs FS) NewStat() (Stat, error) {
-	f, err := fs.open("stat")
+	f, err := os.Open(fs.Path("stat"))
 	if err != nil {
 		return Stat{}, err
 	}

vendor/github.com/prometheus/procfs/xfs/parse.go

@@ -0,0 +1,361 @@
+// Copyright 2017 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 xfs
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"strconv"
+	"strings"
+)
+
+// ParseStats parses a Stats from an input io.Reader, using the format
+// found in /proc/fs/xfs/stat.
+func ParseStats(r io.Reader) (*Stats, error) {
+	const (
+		// Fields parsed into stats structures.
+		fieldExtentAlloc = "extent_alloc"
+		fieldAbt         = "abt"
+		fieldBlkMap      = "blk_map"
+		fieldBmbt        = "bmbt"
+		fieldDir         = "dir"
+		fieldTrans       = "trans"
+		fieldIg          = "ig"
+		fieldLog         = "log"
+		fieldRw          = "rw"
+		fieldAttr        = "attr"
+		fieldIcluster    = "icluster"
+		fieldVnodes      = "vnodes"
+		fieldBuf         = "buf"
+		fieldXpc         = "xpc"
+
+		// Unimplemented at this time due to lack of documentation.
+		fieldPushAil = "push_ail"
+		fieldXstrat  = "xstrat"
+		fieldAbtb2   = "abtb2"
+		fieldAbtc2   = "abtc2"
+		fieldBmbt2   = "bmbt2"
+		fieldIbt2    = "ibt2"
+		fieldFibt2   = "fibt2"
+		fieldQm      = "qm"
+		fieldDebug   = "debug"
+	)
+
+	var xfss Stats
+
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		// Expect at least a string label and a single integer value, ex:
+		//   - abt 0
+		//   - rw 1 2
+		ss := strings.Fields(string(s.Bytes()))
+		if len(ss) < 2 {
+			continue
+		}
+		label := ss[0]
+
+		// Extended precision counters are uint64 values.
+		if label == fieldXpc {
+			us, err := parseUint64s(ss[1:])
+			if err != nil {
+				return nil, err
+			}
+
+			xfss.ExtendedPrecision, err = extendedPrecisionStats(us)
+			if err != nil {
+				return nil, err
+			}
+
+			continue
+		}
+
+		// All other counters are uint32 values.
+		us, err := parseUint32s(ss[1:])
+		if err != nil {
+			return nil, err
+		}
+
+		switch label {
+		case fieldExtentAlloc:
+			xfss.ExtentAllocation, err = extentAllocationStats(us)
+		case fieldAbt:
+			xfss.AllocationBTree, err = btreeStats(us)
+		case fieldBlkMap:
+			xfss.BlockMapping, err = blockMappingStats(us)
+		case fieldBmbt:
+			xfss.BlockMapBTree, err = btreeStats(us)
+		case fieldDir:
+			xfss.DirectoryOperation, err = directoryOperationStats(us)
+		case fieldTrans:
+			xfss.Transaction, err = transactionStats(us)
+		case fieldIg:
+			xfss.InodeOperation, err = inodeOperationStats(us)
+		case fieldLog:
+			xfss.LogOperation, err = logOperationStats(us)
+		case fieldRw:
+			xfss.ReadWrite, err = readWriteStats(us)
+		case fieldAttr:
+			xfss.AttributeOperation, err = attributeOperationStats(us)
+		case fieldIcluster:
+			xfss.InodeClustering, err = inodeClusteringStats(us)
+		case fieldVnodes:
+			xfss.Vnode, err = vnodeStats(us)
+		case fieldBuf:
+			xfss.Buffer, err = bufferStats(us)
+		}
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &xfss, s.Err()
+}
+
+// extentAllocationStats builds an ExtentAllocationStats from a slice of uint32s.
+func extentAllocationStats(us []uint32) (ExtentAllocationStats, error) {
+	if l := len(us); l != 4 {
+		return ExtentAllocationStats{}, fmt.Errorf("incorrect number of values for XFS extent allocation stats: %d", l)
+	}
+
+	return ExtentAllocationStats{
+		ExtentsAllocated: us[0],
+		BlocksAllocated:  us[1],
+		ExtentsFreed:     us[2],
+		BlocksFreed:      us[3],
+	}, nil
+}
+
+// btreeStats builds a BTreeStats from a slice of uint32s.
+func btreeStats(us []uint32) (BTreeStats, error) {
+	if l := len(us); l != 4 {
+		return BTreeStats{}, fmt.Errorf("incorrect number of values for XFS btree stats: %d", l)
+	}
+
+	return BTreeStats{
+		Lookups:         us[0],
+		Compares:        us[1],
+		RecordsInserted: us[2],
+		RecordsDeleted:  us[3],
+	}, nil
+}
+
+// BlockMappingStat builds a BlockMappingStats from a slice of uint32s.
+func blockMappingStats(us []uint32) (BlockMappingStats, error) {
+	if l := len(us); l != 7 {
+		return BlockMappingStats{}, fmt.Errorf("incorrect number of values for XFS block mapping stats: %d", l)
+	}
+
+	return BlockMappingStats{
+		Reads:                us[0],
+		Writes:               us[1],
+		Unmaps:               us[2],
+		ExtentListInsertions: us[3],
+		ExtentListDeletions:  us[4],
+		ExtentListLookups:    us[5],
+		ExtentListCompares:   us[6],
+	}, nil
+}
+
+// DirectoryOperationStats builds a DirectoryOperationStats from a slice of uint32s.
+func directoryOperationStats(us []uint32) (DirectoryOperationStats, error) {
+	if l := len(us); l != 4 {
+		return DirectoryOperationStats{}, fmt.Errorf("incorrect number of values for XFS directory operation stats: %d", l)
+	}
+
+	return DirectoryOperationStats{
+		Lookups:  us[0],
+		Creates:  us[1],
+		Removes:  us[2],
+		Getdents: us[3],
+	}, nil
+}
+
+// TransactionStats builds a TransactionStats from a slice of uint32s.
+func transactionStats(us []uint32) (TransactionStats, error) {
+	if l := len(us); l != 3 {
+		return TransactionStats{}, fmt.Errorf("incorrect number of values for XFS transaction stats: %d", l)
+	}
+
+	return TransactionStats{
+		Sync:  us[0],
+		Async: us[1],
+		Empty: us[2],
+	}, nil
+}
+
+// InodeOperationStats builds an InodeOperationStats from a slice of uint32s.
+func inodeOperationStats(us []uint32) (InodeOperationStats, error) {
+	if l := len(us); l != 7 {
+		return InodeOperationStats{}, fmt.Errorf("incorrect number of values for XFS inode operation stats: %d", l)
+	}
+
+	return InodeOperationStats{
+		Attempts:        us[0],
+		Found:           us[1],
+		Recycle:         us[2],
+		Missed:          us[3],
+		Duplicate:       us[4],
+		Reclaims:        us[5],
+		AttributeChange: us[6],
+	}, nil
+}
+
+// LogOperationStats builds a LogOperationStats from a slice of uint32s.
+func logOperationStats(us []uint32) (LogOperationStats, error) {
+	if l := len(us); l != 5 {
+		return LogOperationStats{}, fmt.Errorf("incorrect number of values for XFS log operation stats: %d", l)
+	}
+
+	return LogOperationStats{
+		Writes:            us[0],
+		Blocks:            us[1],
+		NoInternalBuffers: us[2],
+		Force:             us[3],
+		ForceSleep:        us[4],
+	}, nil
+}
+
+// ReadWriteStats builds a ReadWriteStats from a slice of uint32s.
+func readWriteStats(us []uint32) (ReadWriteStats, error) {
+	if l := len(us); l != 2 {
+		return ReadWriteStats{}, fmt.Errorf("incorrect number of values for XFS read write stats: %d", l)
+	}
+
+	return ReadWriteStats{
+		Read:  us[0],
+		Write: us[1],
+	}, nil
+}
+
+// AttributeOperationStats builds an AttributeOperationStats from a slice of uint32s.
+func attributeOperationStats(us []uint32) (AttributeOperationStats, error) {
+	if l := len(us); l != 4 {
+		return AttributeOperationStats{}, fmt.Errorf("incorrect number of values for XFS attribute operation stats: %d", l)
+	}
+
+	return AttributeOperationStats{
+		Get:    us[0],
+		Set:    us[1],
+		Remove: us[2],
+		List:   us[3],
+	}, nil
+}
+
+// InodeClusteringStats builds an InodeClusteringStats from a slice of uint32s.
+func inodeClusteringStats(us []uint32) (InodeClusteringStats, error) {
+	if l := len(us); l != 3 {
+		return InodeClusteringStats{}, fmt.Errorf("incorrect number of values for XFS inode clustering stats: %d", l)
+	}
+
+	return InodeClusteringStats{
+		Iflush:     us[0],
+		Flush:      us[1],
+		FlushInode: us[2],
+	}, nil
+}
+
+// VnodeStats builds a VnodeStats from a slice of uint32s.
+func vnodeStats(us []uint32) (VnodeStats, error) {
+	// The attribute "Free" appears to not be available on older XFS
+	// stats versions.  Therefore, 7 or 8 elements may appear in
+	// this slice.
+	l := len(us)
+	log.Println(l)
+	if l != 7 && l != 8 {
+		return VnodeStats{}, fmt.Errorf("incorrect number of values for XFS vnode stats: %d", l)
+	}
+
+	s := VnodeStats{
+		Active:   us[0],
+		Allocate: us[1],
+		Get:      us[2],
+		Hold:     us[3],
+		Release:  us[4],
+		Reclaim:  us[5],
+		Remove:   us[6],
+	}
+
+	// Skip adding free, unless it is present. The zero value will
+	// be used in place of an actual count.
+	if l == 7 {
+		return s, nil
+	}
+
+	s.Free = us[7]
+	return s, nil
+}
+
+// BufferStats builds a BufferStats from a slice of uint32s.
+func bufferStats(us []uint32) (BufferStats, error) {
+	if l := len(us); l != 9 {
+		return BufferStats{}, fmt.Errorf("incorrect number of values for XFS buffer stats: %d", l)
+	}
+
+	return BufferStats{
+		Get:             us[0],
+		Create:          us[1],
+		GetLocked:       us[2],
+		GetLockedWaited: us[3],
+		BusyLocked:      us[4],
+		MissLocked:      us[5],
+		PageRetries:     us[6],
+		PageFound:       us[7],
+		GetRead:         us[8],
+	}, nil
+}
+
+// ExtendedPrecisionStats builds an ExtendedPrecisionStats from a slice of uint32s.
+func extendedPrecisionStats(us []uint64) (ExtendedPrecisionStats, error) {
+	if l := len(us); l != 3 {
+		return ExtendedPrecisionStats{}, fmt.Errorf("incorrect number of values for XFS extended precision stats: %d", l)
+	}
+
+	return ExtendedPrecisionStats{
+		FlushBytes: us[0],
+		WriteBytes: us[1],
+		ReadBytes:  us[2],
+	}, nil
+}
+
+// parseUint32s parses a slice of strings into a slice of uint32s.
+func parseUint32s(ss []string) ([]uint32, error) {
+	us := make([]uint32, 0, len(ss))
+	for _, s := range ss {
+		u, err := strconv.ParseUint(s, 10, 32)
+		if err != nil {
+			return nil, err
+		}
+
+		us = append(us, uint32(u))
+	}
+
+	return us, nil
+}
+
+// parseUint64s parses a slice of strings into a slice of uint64s.
+func parseUint64s(ss []string) ([]uint64, error) {
+	us := make([]uint64, 0, len(ss))
+	for _, s := range ss {
+		u, err := strconv.ParseUint(s, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+
+		us = append(us, u)
+	}
+
+	return us, nil
+}

vendor/github.com/prometheus/procfs/xfs/xfs.go

@@ -0,0 +1,158 @@
+// Copyright 2017 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 xfs provides access to statistics exposed by the XFS filesystem.
+package xfs
+
+// Stats contains XFS filesystem runtime statistics, parsed from
+// /proc/fs/xfs/stat.
+//
+// The names and meanings of each statistic were taken from
+// http://xfs.org/index.php/Runtime_Stats and xfs_stats.h in the Linux
+// kernel source. Most counters are uint32s (same data types used in
+// xfs_stats.h), but some of the "extended precision stats" are uint64s.
+type Stats struct {
+	ExtentAllocation   ExtentAllocationStats
+	AllocationBTree    BTreeStats
+	BlockMapping       BlockMappingStats
+	BlockMapBTree      BTreeStats
+	DirectoryOperation DirectoryOperationStats
+	Transaction        TransactionStats
+	InodeOperation     InodeOperationStats
+	LogOperation       LogOperationStats
+	ReadWrite          ReadWriteStats
+	AttributeOperation AttributeOperationStats
+	InodeClustering    InodeClusteringStats
+	Vnode              VnodeStats
+	Buffer             BufferStats
+	ExtendedPrecision  ExtendedPrecisionStats
+}
+
+// ExtentAllocationStats contains statistics regarding XFS extent allocations.
+type ExtentAllocationStats struct {
+	ExtentsAllocated uint32
+	BlocksAllocated  uint32
+	ExtentsFreed     uint32
+	BlocksFreed      uint32
+}
+
+// BTreeStats contains statistics regarding an XFS internal B-tree.
+type BTreeStats struct {
+	Lookups         uint32
+	Compares        uint32
+	RecordsInserted uint32
+	RecordsDeleted  uint32
+}
+
+// BlockMappingStats contains statistics regarding XFS block maps.
+type BlockMappingStats struct {
+	Reads                uint32
+	Writes               uint32
+	Unmaps               uint32
+	ExtentListInsertions uint32
+	ExtentListDeletions  uint32
+	ExtentListLookups    uint32
+	ExtentListCompares   uint32
+}
+
+// DirectoryOperationStats contains statistics regarding XFS directory entries.
+type DirectoryOperationStats struct {
+	Lookups  uint32
+	Creates  uint32
+	Removes  uint32
+	Getdents uint32
+}
+
+// TransactionStats contains statistics regarding XFS metadata transactions.
+type TransactionStats struct {
+	Sync  uint32
+	Async uint32
+	Empty uint32
+}
+
+// InodeOperationStats contains statistics regarding XFS inode operations.
+type InodeOperationStats struct {
+	Attempts        uint32
+	Found           uint32
+	Recycle         uint32
+	Missed          uint32
+	Duplicate       uint32
+	Reclaims        uint32
+	AttributeChange uint32
+}
+
+// LogOperationStats contains statistics regarding the XFS log buffer.
+type LogOperationStats struct {
+	Writes            uint32
+	Blocks            uint32
+	NoInternalBuffers uint32
+	Force             uint32
+	ForceSleep        uint32
+}
+
+// ReadWriteStats contains statistics regarding the number of read and write
+// system calls for XFS filesystems.
+type ReadWriteStats struct {
+	Read  uint32
+	Write uint32
+}
+
+// AttributeOperationStats contains statistics regarding manipulation of
+// XFS extended file attributes.
+type AttributeOperationStats struct {
+	Get    uint32
+	Set    uint32
+	Remove uint32
+	List   uint32
+}
+
+// InodeClusteringStats contains statistics regarding XFS inode clustering
+// operations.
+type InodeClusteringStats struct {
+	Iflush     uint32
+	Flush      uint32
+	FlushInode uint32
+}
+
+// VnodeStats contains statistics regarding XFS vnode operations.
+type VnodeStats struct {
+	Active   uint32
+	Allocate uint32
+	Get      uint32
+	Hold     uint32
+	Release  uint32
+	Reclaim  uint32
+	Remove   uint32
+	Free     uint32
+}
+
+// BufferStats contains statistics regarding XFS read/write I/O buffers.
+type BufferStats struct {
+	Get             uint32
+	Create          uint32
+	GetLocked       uint32
+	GetLockedWaited uint32
+	BusyLocked      uint32
+	MissLocked      uint32
+	PageRetries     uint32
+	PageFound       uint32
+	GetRead         uint32
+}
+
+// ExtendedPrecisionStats contains high precision counters used to track the
+// total number of bytes read, written, or flushed, during XFS operations.
+type ExtendedPrecisionStats struct {
+	FlushBytes uint64
+	WriteBytes uint64
+	ReadBytes  uint64
+}