Add FS handler for mountinfo (#757)

Add FS function handlers for parsing `mountinfo` data.

Signed-off-by: SuperQ <superq@gmail.com>

Author: SuperQ

mountinfo.go

@@ -177,3 +177,21 @@ func GetProcMounts(pid int) ([]*MountInfo, error) {
 	}
 	return parseMountInfo(data)
 }
+
+// GetMounts retrieves mountinfo information from `/proc/self/mountinfo`.
+func (fs FS) GetMounts() ([]*MountInfo, error) {
+	data, err := util.ReadFileNoStat(fs.proc.Path("self/mountinfo"))
+	if err != nil {
+		return nil, err
+	}
+	return parseMountInfo(data)
+}
+
+// GetProcMounts retrieves mountinfo information from a processes' `/proc/<pid>/mountinfo`.
+func (fs FS) GetProcMounts(pid int) ([]*MountInfo, error) {
+	data, err := util.ReadFileNoStat(fs.proc.Path(fmt.Sprintf("%d/mountinfo", pid)))
+	if err != nil {
+		return nil, err
+	}
+	return parseMountInfo(data)
+}

mountinfo_test.go

@@ -15,6 +15,8 @@ package procfs
 import (
 	"reflect"
 	"testing"
+
+	"github.com/google/go-cmp/cmp"
 )
 
 func TestMountInfo(t *testing.T) {
@@ -182,3 +184,188 @@ func TestMountInfo(t *testing.T) {
 		}
 	}
 }
+
+func TestFSMountInfo(t *testing.T) {
+	fs, err := NewFS(procTestFixtures)
+	if err != nil {
+		t.Fatalf("failed to open procfs: %v", err)
+	}
+
+	want := []*MountInfo{
+		{
+			MountID:        1,
+			ParentID:       1,
+			MajorMinorVer:  "0:5",
+			Root:           "/",
+			Options:        map[string]string{"/root": ""},
+			OptionalFields: map[string]string{"shared": "8"},
+			FSType:         "rootfs",
+			Source:         "rootfs",
+			SuperOptions:   map[string]string{"rw": ""},
+		},
+		{
+			MountID:        16,
+			ParentID:       21,
+			MajorMinorVer:  "0:16",
+			Root:           "/",
+			MountPoint:     "/sys",
+			Options:        map[string]string{"nodev": "", "noexec": "", "nosuid": "", "relatime": "", "rw": ""},
+			OptionalFields: map[string]string{"shared": "7"},
+			FSType:         "sysfs",
+			Source:         "sysfs",
+			SuperOptions:   map[string]string{"rw": ""},
+		},
+		{
+			MountID:        17,
+			ParentID:       21,
+			MajorMinorVer:  "0:4",
+			Root:           "/",
+			MountPoint:     "/proc",
+			Options:        map[string]string{"nodev": "", "noexec": "", "nosuid": "", "relatime": "", "rw": ""},
+			OptionalFields: map[string]string{"shared": "12"},
+			FSType:         "proc",
+			Source:         "proc",
+			SuperOptions:   map[string]string{"rw": ""},
+		},
+		{
+			MountID:        21,
+			MajorMinorVer:  "8:1",
+			Root:           "/",
+			MountPoint:     "/",
+			Options:        map[string]string{"relatime": "", "rw": ""},
+			OptionalFields: map[string]string{"shared": "1"},
+			FSType:         "ext4",
+			Source:         "/dev/sda1",
+			SuperOptions:   map[string]string{"data": "ordered", "errors": "remount-ro", "rw": ""},
+		},
+		{
+			MountID:        194,
+			ParentID:       21,
+			MajorMinorVer:  "0:42",
+			Root:           "/",
+			MountPoint:     "/mnt/nfs/test",
+			Options:        map[string]string{"rw": ""},
+			OptionalFields: map[string]string{"shared": "144"},
+			FSType:         "nfs4",
+			Source:         "192.168.1.1:/srv/test",
+			SuperOptions: map[string]string{
+				"acdirmax":   "60",
+				"acdirmin":   "30",
+				"acregmax":   "60",
+				"acregmin":   "3",
+				"addr":       "192.168.1.1",
+				"clientaddr": "192.168.1.5",
+				"hard":       "",
+				"local_lock": "none",
+				"namlen":     "255",
+				"port":       "0",
+				"proto":      "tcp",
+				"retrans":    "2",
+				"rsize":      "1048576",
+				"rw":         "",
+				"sec":        "sys",
+				"timeo":      "600",
+				"vers":       "4.0",
+				"wsize":      "1048576",
+			},
+		},
+		{
+			MountID:        177,
+			ParentID:       21,
+			MajorMinorVer:  "0:42",
+			Root:           "/",
+			MountPoint:     "/mnt/nfs/test",
+			Options:        map[string]string{"rw": ""},
+			OptionalFields: map[string]string{"shared": "130"},
+			FSType:         "nfs4",
+			Source:         "192.168.1.1:/srv/test",
+			SuperOptions: map[string]string{
+				"acdirmax":   "60",
+				"acdirmin":   "30",
+				"acregmax":   "60",
+				"acregmin":   "3",
+				"addr":       "192.168.1.1",
+				"clientaddr": "192.168.1.5",
+				"hard":       "",
+				"local_lock": "none",
+				"namlen":     "255",
+				"port":       "0",
+				"proto":      "tcp",
+				"retrans":    "2",
+				"rsize":      "1048576",
+				"rw":         "",
+				"sec":        "sys",
+				"timeo":      "600",
+				"vers":       "4.0",
+				"wsize":      "1048576",
+			},
+		},
+		{
+			MountID:        1398,
+			ParentID:       798,
+			MajorMinorVer:  "0:44",
+			Root:           "/",
+			MountPoint:     "/mnt/nfs/test",
+			Options:        map[string]string{"relatime": "", "rw": ""},
+			OptionalFields: map[string]string{"shared": "1154"},
+			FSType:         "nfs",
+			Source:         "192.168.1.1:/srv/test",
+			SuperOptions: map[string]string{
+				"addr":       "192.168.1.1",
+				"hard":       "",
+				"local_lock": "none",
+				"mountaddr":  "192.168.1.1",
+				"mountport":  "49602",
+				"mountproto": "udp",
+				"mountvers":  "3",
+				"namlen":     "255",
+				"proto":      "udp",
+				"retrans":    "3",
+				"rsize":      "32768",
+				"rw":         "",
+				"sec":        "sys",
+				"timeo":      "11",
+				"vers":       "3",
+				"wsize":      "32768",
+			},
+		},
+		{
+			MountID:        1128,
+			ParentID:       67,
+			MajorMinorVer:  "253:0",
+			Root:           "/var/lib/containers/storage/overlay",
+			MountPoint:     "/var/lib/containers/storage/overlay",
+			Options:        map[string]string{"relatime": "", "rw": ""},
+			OptionalFields: map[string]string{},
+			FSType:         "xfs",
+			Source:         "/dev/mapper/rhel-root",
+			SuperOptions: map[string]string{
+				"attr2":    "",
+				"inode64":  "",
+				"logbsize": "32k",
+				"logbufs":  "8",
+				"noquota":  "",
+				"rw":       "",
+				"seclabel": "",
+			},
+		},
+	}
+
+	got, err := fs.GetMounts()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Fatalf("unexpected mountpoints (-want +got):\n%s", diff)
+	}
+
+	got, err = fs.GetProcMounts(26231)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Fatalf("unexpected mountpoints (-want +got):\n%s", diff)
+	}
+}

testdata/fixtures.ttar

@@ -174,6 +174,18 @@ Max realtime priority     0                    0
 Max realtime timeout      unlimited            unlimited            us
 Mode: 644
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/proc/26231/mountinfo
+Lines: 8
+1 1 0:5 /  /root rw,nosuid shared:8 - rootfs rootfs rw
+16 21 0:16 / /sys rw,nosuid,nodev,noexec,relatime shared:7 - sysfs sysfs rw
+17 21 0:4 / /proc rw,nosuid,nodev,noexec,relatime shared:12 - proc proc rw
+21 0 8:1 / / rw,relatime shared:1 - ext4 /dev/sda1 rw,errors=remount-ro,data=ordered
+194 21 0:42 / /mnt/nfs/test rw shared:144 - nfs4 192.168.1.1:/srv/test rw,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.5,addr=192.168.1.1,local_lock=none
+177 21 0:42 / /mnt/nfs/test rw shared:130 - nfs4 192.168.1.1:/srv/test rw,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.5,addr=192.168.1.1,local_lock=none
+1398 798 0:44 / /mnt/nfs/test rw,relatime shared:1154 - nfs 192.168.1.1:/srv/test rw,vers=3,rsize=32768,wsize=32768,namlen=255,hard,proto=udp,timeo=11,retrans=3,sec=sys,mountaddr=192.168.1.1,mountvers=3,mountport=49602,mountproto=udp,local_lock=none,addr=192.168.1.1
+1128 67 253:0 /var/lib/containers/storage/overlay /var/lib/containers/storage/overlay rw,relatime - xfs /dev/mapper/rhel-root rw,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota
+Mode: 664
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Path: fixtures/proc/26231/mountstats
 Lines: 20
 device rootfs mounted on / with fstype rootfs