Correct FDSize in /proc/[pid]/status.

In Linux, FDSize is fs/proc/array.c:task_state() => struct fdtable::max_fds,
which is set to the underlying array's length in fs/file.c:alloc_fdtable().

Follow-up changes:

- Remove FDTable.GetRefs() and FDTable.GetRefsVFS2(), which are unused.

- Reset FDTable.used to 0 during restore, since the subsequent calls to
  FDTable.setAll() increment it again, causing its value to be doubled. (After
  this CL, FDTable.used is only used to avoid reallocation in FDTable.GetFDs(),
  so this fix is not very visible.)

PiperOrigin-RevId: 331588190

1 files changed, 1 insertions, 1 deletions

diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go
index 356036b9b..ce87b0d47 100644
--- a/pkg/sentry/fsimpl/proc/task_files.go
+++ b/pkg/sentry/fsimpl/proc/task_files.go
@@ -543,7 +543,7 @@ func (s *statusData) Generate(ctx context.Context, buf *bytes.Buffer) error {
 	var vss, rss, data uint64
 	s.task.WithMuLocked(func(t *kernel.Task) {
 		if fdTable := t.FDTable(); fdTable != nil {
-			fds = fdTable.Size()
+			fds = fdTable.CurrentMaxFDs()
 		}
 		if mm := t.MemoryManager(); mm != nil {
 			vss = mm.VirtualMemorySize()