[disk] Partition returns all list even if argument is False.

According to https://github.com/giampaolo/psutil/issues/906,
all BSD system returns same information `df` and `df -a`.

disk/disk_darwin.go

@@ -4,7 +4,6 @@ package disk
 
 import (
 	"context"
-	"path"
 
 	"github.com/shirou/gopsutil/internal/common"
 	"golang.org/x/sys/unix"
@@ -14,6 +13,8 @@ func Partitions(all bool) ([]PartitionStat, error) {
 	return PartitionsWithContext(context.Background(), all)
 }
 
+// PartitionsWithContext returns disk partition.
+// 'all' argument is ignored, see: https://github.com/giampaolo/psutil/issues/906
 func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, error) {
 	var ret []PartitionStat
 
@@ -69,11 +70,6 @@ func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, erro
 			Fstype:     common.ByteToString(stat.Fstypename[:]),
 			Opts:       opts,
 		}
-		if all == false {
-			if !path.IsAbs(d.Device) || !common.PathExists(d.Device) {
-				continue
-			}
-		}
 
 		ret = append(ret, d)
 	}

disk/disk_freebsd.go

@@ -6,7 +6,6 @@ import (
 	"bytes"
 	"context"
 	"encoding/binary"
-	"path"
 	"strconv"
 
 	"golang.org/x/sys/unix"
@@ -18,6 +17,8 @@ func Partitions(all bool) ([]PartitionStat, error) {
 	return PartitionsWithContext(context.Background(), all)
 }
 
+// PartitionsWithContext returns disk partition.
+// 'all' argument is ignored, see: https://github.com/giampaolo/psutil/issues/906
 func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, error) {
 	var ret []PartitionStat
 
@@ -89,11 +90,6 @@ func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, erro
 			Fstype:     common.ByteToString(stat.Fstypename[:]),
 			Opts:       opts,
 		}
-		if all == false {
-			if !path.IsAbs(d.Device) || !common.PathExists(d.Device) {
-				continue
-			}
-		}
 
 		ret = append(ret, d)
 	}

disk/disk_openbsd.go

@@ -6,7 +6,6 @@ import (
 	"bytes"
 	"context"
 	"encoding/binary"
-	"path"
 
 	"github.com/shirou/gopsutil/internal/common"
 	"golang.org/x/sys/unix"
@@ -16,6 +15,8 @@ func Partitions(all bool) ([]PartitionStat, error) {
 	return PartitionsWithContext(context.Background(), all)
 }
 
+// PartitionsWithContext returns disk partition.
+// 'all' argument is ignored, see: https://github.com/giampaolo/psutil/issues/906
 func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, error) {
 	var ret []PartitionStat
 
@@ -66,11 +67,6 @@ func PartitionsWithContext(ctx context.Context, all bool) ([]PartitionStat, erro
 			Fstype:     common.IntToString(stat.F_fstypename[:]),
 			Opts:       opts,
 		}
-		if all == false {
-			if !path.IsAbs(d.Device) || !common.PathExists(d.Device) {
-				continue
-			}
-		}
 
 		ret = append(ret, d)
 	}