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, 22 insertions, 39 deletions

diff --git a/fs/open.c b/fs/open.c
index 446ab8ef04af..4b37c5912e6c 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -187,19 +187,13 @@ long do_ftruncate(struct file *file, loff_t length, int small)
 
 long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
 {
-	struct fd f;
-	int error;
-
 	if (length < 0)
 		return -EINVAL;
-	f = fdget(fd);
-	if (!fd_file(f))
+	CLASS(fd, f)(fd);
+	if (fd_empty(f))
 		return -EBADF;
 
-	error = do_ftruncate(fd_file(f), length, small);
-
-	fdput(f);
-	return error;
+	return do_ftruncate(fd_file(f), length, small);
 }
 
 SYSCALL_DEFINE2(ftruncate, unsigned int, fd, off_t, length)
@@ -349,14 +343,12 @@ EXPORT_SYMBOL_GPL(vfs_fallocate);
 
 int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
 {
-	struct fd f = fdget(fd);
-	int error = -EBADF;
+	CLASS(fd, f)(fd);
 
-	if (fd_file(f)) {
-		error = vfs_fallocate(fd_file(f), mode, offset, len);
-		fdput(f);
-	}
-	return error;
+	if (fd_empty(f))
+		return -EBADF;
+
+	return vfs_fallocate(fd_file(f), mode, offset, len);
 }
 
 SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
@@ -580,23 +572,18 @@ out:
 
 SYSCALL_DEFINE1(fchdir, unsigned int, fd)
 {
-	struct fd f = fdget_raw(fd);
+	CLASS(fd_raw, f)(fd);
 	int error;
 
-	error = -EBADF;
-	if (!fd_file(f))
-		goto out;
+	if (fd_empty(f))
+		return -EBADF;
 
-	error = -ENOTDIR;
 	if (!d_can_lookup(fd_file(f)->f_path.dentry))
-		goto out_putf;
+		return -ENOTDIR;
 
 	error = file_permission(fd_file(f), MAY_EXEC | MAY_CHDIR);
 	if (!error)
 		set_fs_pwd(current->fs, &fd_file(f)->f_path);
-out_putf:
-	fdput(f);
-out:
 	return error;
 }
 
@@ -671,14 +658,12 @@ int vfs_fchmod(struct file *file, umode_t mode)
 
 SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
 {
-	struct fd f = fdget(fd);
-	int err = -EBADF;
+	CLASS(fd, f)(fd);
 
-	if (fd_file(f)) {
-		err = vfs_fchmod(fd_file(f), mode);
-		fdput(f);
-	}
-	return err;
+	if (fd_empty(f))
+		return -EBADF;
+
+	return vfs_fchmod(fd_file(f), mode);
 }
 
 static int do_fchmodat(int dfd, const char __user *filename, umode_t mode,
@@ -865,14 +850,12 @@ int vfs_fchown(struct file *file, uid_t user, gid_t group)
 
 int ksys_fchown(unsigned int fd, uid_t user, gid_t group)
 {
-	struct fd f = fdget(fd);
-	int error = -EBADF;
+	CLASS(fd, f)(fd);
 
-	if (fd_file(f)) {
-		error = vfs_fchown(fd_file(f), user, group);
-		fdput(f);
-	}
-	return error;
+	if (fd_empty(f))
+		return -EBADF;
+
+	return vfs_fchown(fd_file(f), user, group);
 }
 
 SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)