Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...

1 files changed, 7 insertions, 14 deletions

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 044c7ba1cc48..9bc4a84bd309 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6476,7 +6476,6 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
 	struct cgroup *dst_cgrp = NULL;
 	struct css_set *cset;
 	struct super_block *sb;
-	struct file *f;
 
 	if (kargs->flags & CLONE_INTO_CGROUP)
 		cgroup_lock();
@@ -6493,14 +6492,14 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
 		return 0;
 	}
 
-	f = fget_raw(kargs->cgroup);
-	if (!f) {
+	CLASS(fd_raw, f)(kargs->cgroup);
+	if (fd_empty(f)) {
 		ret = -EBADF;
 		goto err;
 	}
-	sb = f->f_path.dentry->d_sb;
+	sb = fd_file(f)->f_path.dentry->d_sb;
 
-	dst_cgrp = cgroup_get_from_file(f);
+	dst_cgrp = cgroup_get_from_file(fd_file(f));
 	if (IS_ERR(dst_cgrp)) {
 		ret = PTR_ERR(dst_cgrp);
 		dst_cgrp = NULL;
@@ -6548,15 +6547,12 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
 	}
 
 	put_css_set(cset);
-	fput(f);
 	kargs->cgrp = dst_cgrp;
 	return ret;
 
 err:
 	cgroup_threadgroup_change_end(current);
 	cgroup_unlock();
-	if (f)
-		fput(f);
 	if (dst_cgrp)
 		cgroup_put(dst_cgrp);
 	put_css_set(cset);
@@ -6966,14 +6962,11 @@ EXPORT_SYMBOL_GPL(cgroup_get_from_path);
  */
 struct cgroup *cgroup_v1v2_get_from_fd(int fd)
 {
-	struct cgroup *cgrp;
-	struct fd f = fdget_raw(fd);
-	if (!fd_file(f))
+	CLASS(fd_raw, f)(fd);
+	if (fd_empty(f))
 		return ERR_PTR(-EBADF);
 
-	cgrp = cgroup_v1v2_get_from_file(fd_file(f));
-	fdput(f);
-	return cgrp;
+	return cgroup_v1v2_get_from_file(fd_file(f));
 }
 
 /**