update procfs to latest (#1335)

Updates for procfs refactoring

Signed-off-by: Paul Gier <pgier@redhat.com>

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

@@ -14,95 +14,24 @@
 package sysfs
 
 import (
-	"fmt"
-	"os"
-	"path/filepath"
-
-	"github.com/prometheus/procfs/bcache"
-	"github.com/prometheus/procfs/xfs"
+	"github.com/prometheus/procfs/internal/fs"
 )
 
 // FS represents the pseudo-filesystem sys, which provides an interface to
 // kernel data structures.
-type FS string
+type FS struct {
+	sys fs.FS
+}
 
 // DefaultMountPoint is the common mount point of the sys filesystem.
-const DefaultMountPoint = "/sys"
+const DefaultMountPoint = fs.DefaultSysMountPoint
 
 // NewFS returns a new FS mounted under the given mountPoint. It will error
 // if the mount point can't be read.
 func NewFS(mountPoint string) (FS, error) {
-	info, err := os.Stat(mountPoint)
+	fs, err := fs.NewFS(mountPoint)
 	if err != nil {
-		return "", fmt.Errorf("could not read %s: %s", mountPoint, err)
+		return FS{}, err
 	}
-	if !info.IsDir() {
-		return "", fmt.Errorf("mount point %s is not a directory", mountPoint)
-	}
-
-	return FS(mountPoint), nil
-}
-
-// Path returns the path of the given subsystem relative to the sys root.
-func (fs FS) Path(p ...string) string {
-	return filepath.Join(append([]string{string(fs)}, p...)...)
-}
-
-// XFSStats retrieves XFS filesystem runtime statistics for each mounted XFS
-// filesystem.  Only available on kernel 4.4+.  On older kernels, an empty
-// slice of *xfs.Stats will be returned.
-func (fs FS) XFSStats() ([]*xfs.Stats, error) {
-	matches, err := filepath.Glob(fs.Path("fs/xfs/*/stats/stats"))
-	if err != nil {
-		return nil, err
-	}
-
-	stats := make([]*xfs.Stats, 0, len(matches))
-	for _, m := range matches {
-		f, err := os.Open(m)
-		if err != nil {
-			return nil, err
-		}
-
-		// "*" used in glob above indicates the name of the filesystem.
-		name := filepath.Base(filepath.Dir(filepath.Dir(m)))
-
-		// File must be closed after parsing, regardless of success or
-		// failure.  Defer is not used because of the loop.
-		s, err := xfs.ParseStats(f)
-		_ = f.Close()
-		if err != nil {
-			return nil, err
-		}
-
-		s.Name = name
-		stats = append(stats, s)
-	}
-
-	return stats, nil
-}
-
-// BcacheStats retrieves bcache runtime statistics for each bcache.
-func (fs FS) BcacheStats() ([]*bcache.Stats, error) {
-	matches, err := filepath.Glob(fs.Path("fs/bcache/*-*"))
-	if err != nil {
-		return nil, err
-	}
-
-	stats := make([]*bcache.Stats, 0, len(matches))
-	for _, uuidPath := range matches {
-		// "*-*" in glob above indicates the name of the bcache.
-		name := filepath.Base(uuidPath)
-
-		// stats
-		s, err := bcache.GetStats(uuidPath)
-		if err != nil {
-			return nil, err
-		}
-
-		s.Name = name
-		stats = append(stats, s)
-	}
-
-	return stats, nil
+	return FS{fs}, nil
 }