PWX-30476: Upgrade GetMounts call to use the latest (libopenstorage#2293

)

* PWX-30476: Upgrade GetMounts call to use the latest

Signed-off-by: pnookala-px <[email protected]>

* PWX-30476: Fix Test path

Signed-off-by: pnookala-px <[email protected]>

---------

Signed-off-by: pnookala-px <[email protected]>
Co-authored-by: Harsh Desai <[email protected]>

go.mod

@@ -25,6 +25,8 @@ require (
 	github.com/libopenstorage/gossip v0.0.0-20220309192431-44c895e0923e
 	github.com/libopenstorage/secrets v0.0.0-20200207034622-cdb443738c67
 	github.com/libopenstorage/systemutils v0.0.0-20160208220149-44ac83be3ce1
+	github.com/moby/sys/mount v0.2.0
+	github.com/moby/sys/mountinfo v0.4.0
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826
 	github.com/onsi/ginkgo v1.16.5
 	github.com/onsi/gomega v1.16.0
@@ -103,8 +105,6 @@ require (
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/mapstructure v1.3.3 // indirect
 	github.com/moby/locker v1.0.1 // indirect
-	github.com/moby/sys/mount v0.2.0 // indirect
-	github.com/moby/sys/mountinfo v0.4.0 // indirect
 	github.com/moby/sys/symlink v0.1.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect

pkg/mount/bind_mount.go

@@ -6,7 +6,7 @@ import (
 	"regexp"
 	"strings"
 
-	"github.com/docker/docker/pkg/mount"
+	"github.com/moby/sys/mountinfo"
 	"github.com/libopenstorage/openstorage/pkg/keylock"
 )
 
@@ -60,7 +60,7 @@ func (b *bindMounter) Load(rootSubstrings []*regexp.Regexp) error {
 	return b.load(rootSubstrings, bindFindMountPoint)
 }
 
-func bindFindMountPoint(sInfo *mount.Info, destination *regexp.Regexp, infos []*mount.Info) (bool, string, string) {
+func bindFindMountPoint(sInfo *mountinfo.Info, destination *regexp.Regexp, infos []*mountinfo.Info) (bool, string, string) {
 	for _, dInfo := range infos {
 		if !destination.MatchString(dInfo.Mountpoint) {
 			continue

pkg/mount/consistent_read.go

@@ -30,8 +30,9 @@ import (
 	"io"
 	"io/ioutil"
 	"strings"
+	"strconv"
 
-	"github.com/docker/docker/pkg/mount"
+	"github.com/moby/sys/mountinfo"
 )
 
 const (
@@ -58,7 +59,7 @@ var ErrLimitReached = errors.New("the read limit is reached")
 // Parse /proc/self/mountinfo because comparing Dev and ino does not work from
 // bind mounts. function is originally from
 // https://github.com/moby/sys/blob/65f80e71a828ef17e6f573176dc569e55f519937/mountinfo/mountinfo_linux.go
-func parseMountTable() ([]*mount.Info, error) {
+func parseMountTable() ([]*mountinfo.Info, error) {
 	mountInfoBytes, err := consistentRead("/proc/self/mountinfo", 3)
 	if err != nil {
 		return nil, err
@@ -90,43 +91,162 @@ func consistentRead(filename string, attempts int) ([]byte, error) {
 	return nil, fmt.Errorf("could not get consistent content of mount table after %d attempts", attempts)
 }
 
-func parseInfoFile(r io.Reader) ([]*mount.Info, error) {
+func parseInfoFile(r io.Reader) ([]*mountinfo.Info, error) {
 	var (
 		s   = bufio.NewScanner(r)
-		out = []*mount.Info{}
+		out = []*mountinfo.Info{}
 	)
 
 	for s.Scan() {
-		if err := s.Err(); err != nil {
+		var err error
+		if err = s.Err(); err != nil {
 			return nil, err
 		}
+		/*
+		   See http://man7.org/linux/man-pages/man5/proc.5.html
+
+		   36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue
+		   (1)(2)(3)   (4)   (5)      (6)      (7)   (8) (9)   (10)         (11)
+
+		   (1) mount ID:  unique identifier of the mount (may be reused after umount)
+		   (2) parent ID:  ID of parent (or of self for the top of the mount tree)
+		   (3) major:minor:  value of st_dev for files on filesystem
+		   (4) root:  root of the mount within the filesystem
+		   (5) mount point:  mount point relative to the process's root
+		   (6) mount options:  per mount options
+		   (7) optional fields:  zero or more fields of the form "tag[:value]"
+		   (8) separator:  marks the end of the optional fields
+		   (9) filesystem type:  name of filesystem of the form "type[.subtype]"
+		   (10) mount source:  filesystem specific information or "none"
+		   (11) super options:  per super block options
+
+		   In other words, we have:
+		    * 6 mandatory fields	(1)..(6)
+		    * 0 or more optional fields	(7)
+		    * a separator field		(8)
+		    * 3 mandatory fields	(9)..(11)
+		*/
+
+		text := s.Text()
+		fields := strings.Split(text, " ")
+		numFields := len(fields)
+		if numFields < 10 {
+			// should be at least 10 fields
+			return nil, fmt.Errorf("parsing '%s' failed: not enough fields (%d)", text, numFields)
+		}
+
+		// separator field
+		sepIdx := numFields - 4
+		// In Linux <= 3.9 mounting a cifs with spaces in a share
+		// name (like "//srv/My Docs") _may_ end up having a space
+		// in the last field of mountinfo (like "unc=//serv/My Docs").
+		// Since kernel 3.10-rc1, cifs option "unc=" is ignored,
+		// so spaces should not appear.
+		//
+		// Check for a separator, and work around the spaces bug
+		for fields[sepIdx] != "-" {
+			sepIdx--
+			if sepIdx == 5 {
+				return nil, fmt.Errorf("parsing '%s' failed: missing - separator", text)
+			}
+		}
 
-		var (
-			p              = &mount.Info{}
-			text           = s.Text()
-			optionalFields string
-		)
+		p := &mountinfo.Info{}
 
-		if _, err := fmt.Sscanf(text, mountinfoFormat,
-			&p.ID, &p.Parent, &p.Major, &p.Minor,
-			&p.Root, &p.Mountpoint, &p.Opts, &optionalFields); err != nil {
-			return nil, fmt.Errorf("Scanning '%s' failed: %s", text, err)
+		p.Mountpoint, err = unescape(fields[4])
+		if err != nil {
+			return nil, fmt.Errorf("parsing '%s' failed: mount point: %w", fields[4], err)
 		}
-		// Safe as mountinfo encodes mountpoints with spaces as \040.
-		index := strings.Index(text, " - ")
-		postSeparatorFields := strings.Fields(text[index+3:])
-		if len(postSeparatorFields) < 3 {
-			return nil, fmt.Errorf("Error found less than 3 fields post '-' in %q", text)
+		p.FSType, err = unescape(fields[sepIdx+1])
+		if err != nil {
+			return nil, fmt.Errorf("parsing '%s' failed: fstype: %w", fields[sepIdx+1], err)
 		}
+		p.Source, err = unescape(fields[sepIdx+2])
+		if err != nil {
+			return nil, fmt.Errorf("parsing '%s' failed: source: %w", fields[sepIdx+2], err)
+		}
+		p.VFSOptions = fields[sepIdx+3]
+
+		// ignore any numbers parsing errors, as there should not be any
+		p.ID, _ = strconv.Atoi(fields[0])
+		p.Parent, _ = strconv.Atoi(fields[1])
+		mm := strings.SplitN(fields[2], ":", 3)
+		if len(mm) != 2 {
+			return nil, fmt.Errorf("parsing '%s' failed: unexpected major:minor pair %s", text, mm)
+		}
+		p.Major, _ = strconv.Atoi(mm[0])
+		p.Minor, _ = strconv.Atoi(mm[1])
 
-		if optionalFields != "-" {
-			p.Optional = optionalFields
+		p.Root, err = unescape(fields[3])
+		if err != nil {
+			return nil, fmt.Errorf("parsing '%s' failed: root: %w", fields[3], err)
 		}
 
-		p.Fstype = postSeparatorFields[0]
-		p.Source = postSeparatorFields[1]
-		p.VfsOpts = strings.Join(postSeparatorFields[2:], " ")
+		p.Options = fields[5]
+
+		// zero or more optional fields
+		p.Optional = strings.Join(fields[6:sepIdx], " ")
+
 		out = append(out, p)
 	}
 	return out, nil
 }
+
+
+// A few specific characters in mountinfo path entries (root and mountpoint)
+// are escaped using a backslash followed by a character's ascii code in octal.
+//
+//	space              -- as \040
+//	tab (aka \t)       -- as \011
+//	newline (aka \n)   -- as \012
+//	backslash (aka \\) -- as \134
+//
+// This function converts path from mountinfo back, i.e. it unescapes the above sequences.
+func unescape(path string) (string, error) {
+	// try to avoid copying
+	if strings.IndexByte(path, '\\') == -1 {
+		return path, nil
+	}
+
+	// The following code is UTF-8 transparent as it only looks for some
+	// specific characters (backslash and 0..7) with values < utf8.RuneSelf,
+	// and everything else is passed through as is.
+	buf := make([]byte, len(path))
+	bufLen := 0
+	for i := 0; i < len(path); i++ {
+		if path[i] != '\\' {
+			buf[bufLen] = path[i]
+			bufLen++
+			continue
+		}
+		s := path[i:]
+		if len(s) < 4 {
+			// too short
+			return "", fmt.Errorf("bad escape sequence %q: too short", s)
+		}
+		c := s[1]
+		switch c {
+		case '0', '1', '2', '3', '4', '5', '6', '7':
+			v := c - '0'
+			for j := 2; j < 4; j++ { // one digit already; two more
+				if s[j] < '0' || s[j] > '7' {
+					return "", fmt.Errorf("bad escape sequence %q: not a digit", s[:3])
+				}
+				x := s[j] - '0'
+				v = (v << 3) | x
+			}
+			if v > 255 {
+				return "", fmt.Errorf("bad escape sequence %q: out of range" + s[:3])
+			}
+			buf[bufLen] = v
+			bufLen++
+			i += 3
+			continue
+		default:
+			return "", fmt.Errorf("bad escape sequence %q: not a digit" + s[:3])
+
+		}
+	}
+
+	return string(buf[:bufLen]), nil
+}

pkg/mount/device.go

@@ -8,7 +8,7 @@ import (
 	"regexp"
 	"strings"
 
-	"github.com/docker/docker/pkg/mount"
+	"github.com/moby/sys/mountinfo"
 	"github.com/libopenstorage/openstorage/pkg/keylock"
 )
 
@@ -68,7 +68,7 @@ func (m *deviceMounter) Load(devRegexes []*regexp.Regexp) error {
 	return m.load(devRegexes, deviceFindMountPoint)
 }
 
-func deviceFindMountPoint(info *mount.Info, destination *regexp.Regexp, infos []*mount.Info) (bool, string, string) {
+func deviceFindMountPoint(info *mountinfo.Info, destination *regexp.Regexp, infos []*mountinfo.Info) (bool, string, string) {
 	if destination.MatchString(info.Source) {
 		return true, info.Source, info.Source
 	}

pkg/mount/device_test.go

@@ -5,7 +5,7 @@ import (
 	"regexp"
 	"testing"
 
-	"github.com/docker/docker/pkg/mount"
+	"github.com/moby/sys/mountinfo"
 	"github.com/stretchr/testify/require"
 )
 
@@ -21,8 +21,8 @@ func addMountEntry(t *testing.T, device string, mountpoint string) int {
 	_, err := os.Create(device)
 	require.NoError(t, err, "Failed to create test device: ", device)
 	index := len(testMounts)
-	info := &mount.Info{
-		Fstype:     "ext4",
+	info := &mountinfo.Info{
+		FSType:     "ext4",
 		Minor:      index,
 		Mountpoint: mountpoint,
 		Source:     device,

pkg/mount/mount.go

@@ -18,7 +18,7 @@ import (
 	"syscall"
 	"time"
 
-	"github.com/docker/docker/pkg/mount"
+	"github.com/moby/sys/mountinfo"
 	"github.com/libopenstorage/openstorage/pkg/chattr"
 	"github.com/libopenstorage/openstorage/pkg/keylock"
 	"github.com/libopenstorage/openstorage/pkg/options"
@@ -151,7 +151,7 @@ type Mounter struct {
 	trashLocation string
 }
 
-type findMountPoint func(source *mount.Info, destination *regexp.Regexp, mountInfo []*mount.Info) (bool, string, string)
+type findMountPoint func(source *mountinfo.Info, destination *regexp.Regexp, mountInfo []*mountinfo.Info) (bool, string, string)
 
 // DefaultMounter defaults to syscall implementation.
 type DefaultMounter struct {
@@ -398,7 +398,7 @@ func (m *Mounter) load(prefixes []*regexp.Regexp, fmp findMountPoint) error {
 			if !ok {
 				mount = &Info{
 					Device:     deviceSourcePath,
-					Fs:         v.Fstype,
+					Fs:         v.FSType,
 					Minor:      v.Minor,
 					Mountpoint: make([]*PathInfo, 0),
 				}
@@ -833,7 +833,7 @@ func New(
 
 // GetMounts is a wrapper over mount.GetMounts(). It is mainly used to add a switch
 // to enable device mounter tests.
-func GetMounts() ([]*mount.Info, error) {
+func GetMounts() ([]*mountinfo.Info, error) {
 	if os.Getenv(testDeviceEnv) != "" {
 		return testGetMounts()
 	}
@@ -842,12 +842,12 @@ func GetMounts() ([]*mount.Info, error) {
 
 var (
 	// testMounts is a global test list of mount table entries
-	testMounts []*mount.Info
+	testMounts []*mountinfo.Info
 )
 
 // testGetMounts is only used in tests to get the test list of mount table
 // entries
-func testGetMounts() ([]*mount.Info, error) {
+func testGetMounts() ([]*mountinfo.Info, error) {
 	var err error
 	if len(testMounts) == 0 {
 		testMounts, err = parseMountTable()

pkg/mount/nfs.go

@@ -9,7 +9,7 @@ import (
 	"regexp"
 	"strings"
 
-	"github.com/docker/docker/pkg/mount"
+	"github.com/moby/sys/mountinfo"
 	"github.com/libopenstorage/openstorage/pkg/keylock"
 )
 
@@ -83,8 +83,8 @@ func (m *nfsMounter) serverExists(server string) bool {
 
 // normalizeSource - NFS source is returned as IP:share or just :share
 // normalize that to always IP:share
-func (m *nfsMounter) normalizeSource(info *mount.Info, host string) {
-	if info.Fstype != "nfs" {
+func (m *nfsMounter) normalizeSource(info *mountinfo.Info, host string) {
+	if info.FSType != "nfs" {
 		return
 	}
 
@@ -110,10 +110,10 @@ MountLoop:
 	for _, v := range info {
 		host := "localhost"
 		if len(m.servers) != 0 {
-			if !strings.HasPrefix(v.Fstype, "nfs") {
+			if !strings.HasPrefix(v.FSType, "nfs") {
 				continue
 			}
-			matches := re.FindStringSubmatch(v.VfsOpts)
+			matches := re.FindStringSubmatch(v.VFSOptions)
 			if len(matches) != 2 {
 				continue
 			}
@@ -128,7 +128,7 @@ MountLoop:
 		if !ok {
 			mount = &Info{
 				Device:     v.Source,
-				Fs:         v.Fstype,
+				Fs:         v.FSType,
 				Minor:      v.Minor,
 				Mountpoint: make([]*PathInfo, 0),
 			}