bpo-39327: Close file descriptors as soon as possible in shutil.rmtree (GH-31384)

It fixes the "Text File Busy" OSError when using 'rmtree' on a windows-managed filesystem in via the VirtualBox shared folder (and possible other scenarios like a windows-managed network file system).

Author: smackware

Lib/shutil.py

@@ -648,13 +648,16 @@ def _rmtree_safe_fd(topfd, path, onerror):
  if is_dir:
  try:
  dirfd = os.open(entry.name, os.O_RDONLY, dir_fd=topfd)
+ dirfd_closed = False
  except OSError:
  onerror(os.open, fullname, sys.exc_info())
  else:
  try:
  if os.path.samestat(orig_st, os.fstat(dirfd)):
  _rmtree_safe_fd(dirfd, fullname, onerror)
  try:
+ os.close(dirfd)
+ dirfd_closed = True
  os.rmdir(entry.name, dir_fd=topfd)
  except OSError:
  onerror(os.rmdir, fullname, sys.exc_info())
@@ -668,7 +671,8 @@ def _rmtree_safe_fd(topfd, path, onerror):
  except OSError:
  onerror(os.path.islink, fullname, sys.exc_info())
  finally:
- os.close(dirfd)
+ if not dirfd_closed:
+ os.close(dirfd)
  else:
  try:
  os.unlink(entry.name, dir_fd=topfd)
@@ -711,13 +715,16 @@ def onerror(*args):
  return
  try:
  fd = os.open(path, os.O_RDONLY)
+ fd_closed = False
  except Exception:
  onerror(os.open, path, sys.exc_info())
  return
  try:
  if os.path.samestat(orig_st, os.fstat(fd)):
  _rmtree_safe_fd(fd, path, onerror)
  try:
+ os.close(fd)
+ fd_closed = True
  os.rmdir(path)
  except OSError:
  onerror(os.rmdir, path, sys.exc_info())
@@ -728,7 +735,8 @@ def onerror(*args):
  except OSError:
  onerror(os.path.islink, path, sys.exc_info())
  finally:
- os.close(fd)
+ if not fd_closed:
+ os.close(fd)
  else:
  try:
  if _rmtree_islink(path):

Misc/ACKS

@@ -429,6 +429,7 @@ Caleb Deveraux
 Catherine Devlin
 Scott Dial
 Alon Diamant
+Lital Natan
 Toby Dickenson
 Mark Dickinson
 Jack Diederich

Misc/NEWS.d/next/Library/2022-02-17-13-10-50.bpo-39327.ytIT7Z.rst

@@ -0,0 +1,2 @@
+:func:`shutil.rmtree` can now work with VirtualBox shared folders when
+running from the guest operating-system.