pkg/fileutils: move GetTotalUsedFds internal in daemon

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

pkg/fileutils/fileutils_darwin.go

@@ -1,27 +0,0 @@
-package fileutils // import "github.com/docker/docker/pkg/fileutils"
-
-import (
-	"bytes"
-	"os"
-	"os/exec"
-	"strconv"
-)
-
-// GetTotalUsedFds returns the number of used File Descriptors by executing
-// "lsof -lnP -Ff -p PID".
-//
-// It uses the "-F" option to only print file-descriptors (f), and the "-l",
-// "-n", and "-P" options to omit looking up user-names, host-names, and port-
-// names. See [LSOF(8)].
-//
-// Deprecated: this function is only used internally, and will be removed in the next release.
-//
-// [LSOF(8)]: https://opensource.apple.com/source/lsof/lsof-49/lsof/lsof.man.auto.html
-func GetTotalUsedFds() int {
-	output, err := exec.Command("lsof", "-lnP", "-Ff", "-p", strconv.Itoa(os.Getpid())).CombinedOutput()
-	if err != nil {
-		return -1
-	}
-
-	return bytes.Count(output, []byte("\nf")) // Count number of file descriptor fields in output.
-}

pkg/fileutils/fileutils_linux.go

@@ -1,65 +0,0 @@
-package fileutils
-
-import (
-	"context"
-	"fmt"
-	"io"
-	"os"
-
-	"github.com/containerd/containerd/tracing"
-	"github.com/containerd/log"
-	"golang.org/x/sys/unix"
-)
-
-// GetTotalUsedFds Returns the number of used File Descriptors by
-// reading it via /proc filesystem.
-//
-// Deprecated: this function is only used internally, and will be removed in the next release.
-func GetTotalUsedFds(ctx context.Context) int {
-	ctx, span := tracing.StartSpan(ctx, "GetTotalUsedFds")
-	defer span.End()
-
-	name := fmt.Sprintf("/proc/%d/fd", os.Getpid())
-
-	// Fast-path for Linux 6.2 (since [f1f1f2569901ec5b9d425f2e91c09a0e320768f3]).
-	// From the [Linux docs]:
-	//
-	// "The number of open files for the process is stored in 'size' member of
-	// stat() output for /proc/<pid>/fd for fast access."
-	//
-	// [Linux docs]: https://docs.kernel.org/filesystems/proc.html#proc-pid-fd-list-of-symlinks-to-open-files:
-	// [f1f1f2569901ec5b9d425f2e91c09a0e320768f3]: https://github.com/torvalds/linux/commit/f1f1f2569901ec5b9d425f2e91c09a0e320768f3
-	var stat unix.Stat_t
-	if err := unix.Stat(name, &stat); err == nil && stat.Size > 0 {
-		return int(stat.Size)
-	}
-
-	f, err := os.Open(name)
-	if err != nil {
-		log.G(ctx).WithError(err).Error("Error listing file descriptors")
-		return -1
-	}
-	defer f.Close()
-
-	var fdCount int
-	for {
-		select {
-		case <-ctx.Done():
-			log.G(ctx).WithError(ctx.Err()).Error("Context cancelled while counting file descriptors")
-			return -1
-		default:
-		}
-
-		names, err := f.Readdirnames(100)
-		fdCount += len(names)
-		if err == io.EOF {
-			break
-		} else if err != nil {
-			log.G(ctx).WithError(err).Error("Error listing file descriptors")
-			return -1
-		}
-	}
-	// Note that the slow path has 1 more file-descriptor, due to the open
-	// file-handle for /proc/<pid>/fd during the calculation.
-	return fdCount
-}

pkg/fileutils/fileutils_test.go

@@ -1,7 +1,6 @@
 package fileutils // import "github.com/docker/docker/pkg/fileutils"
 
 import (
-	"context"
 	"errors"
 	"os"
 	"path"
@@ -241,11 +240,3 @@ func TestCreateIfNotExistsFile(t *testing.T) {
 		t.Errorf("Should have been a file, seems it's not")
 	}
 }
-
-func BenchmarkGetTotalUsedFds(b *testing.B) {
-	ctx := context.Background()
-	b.ReportAllocs()
-	for i := 0; i < b.N; i++ {
-		_ = GetTotalUsedFds(ctx)
-	}
-}

pkg/fileutils/fileutils_windows.go

@@ -1,11 +0,0 @@
-package fileutils // import "github.com/docker/docker/pkg/fileutils"
-
-import "context"
-
-// GetTotalUsedFds Returns the number of used File Descriptors. Not supported
-// on Windows.
-//
-// Deprecated: this function is only used internally, and will be removed in the next release.
-func GetTotalUsedFds(ctx context.Context) int {
-	return -1
-}