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

Pull vfs 'struct filename' updates from Al Viro:
 "[Mostly] sanitize struct filename handling"

* tag 'pull-filename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (68 commits)
  sysfs(2): fs_index() argument is _not_ a pathname
  alpha: switch osf_mount() to strndup_user()
  ksmbd: use CLASS(filename_kernel)
  mqueue: switch to CLASS(filename)
  user_statfs(): switch to CLASS(filename)
  statx: switch to CLASS(filename_maybe_null)
  quotactl_block(): switch to CLASS(filename)
  chroot(2): switch to CLASS(filename)
  move_mount(2): switch to CLASS(filename_maybe_null)
  namei.c: switch user pathname imports to CLASS(filename{,_flags})
  namei.c: convert getname_kernel() callers to CLASS(filename_kernel)
  do_f{chmod,chown,access}at(): use CLASS(filename_uflags)
  do_readlinkat(): switch to CLASS(filename_flags)
  do_sys_truncate(): switch to CLASS(filename)
  do_utimes_path(): switch to CLASS(filename_uflags)
  chdir(2): unspaghettify a bit...
  do_fchownat(): unspaghettify a bit...
  fspick(2): use CLASS(filename_flags)
  name_to_handle_at(): use CLASS(filename_uflags)
  vfs_open_tree(): use CLASS(filename_uflags)
  ...

Author: torvalds

Documentation/filesystems/porting.rst

@@ -1340,3 +1340,14 @@ The ->setlease() file_operation must now be explicitly set in order to provide
 support for leases. When set to NULL, the kernel will now return -EINVAL to
 attempts to set a lease. Filesystems that wish to use the kernel-internal lease
 implementation should set it to generic_setlease().
+
+---
+
+**mandatory**
+
+fs/namei.c primitives that consume filesystem references (do_renameat2(),
+do_linkat(), do_symlinkat(), do_mkdirat(), do_mknodat(), do_unlinkat()
+and do_rmdir()) are gone; they are replaced with non-consuming analogues
+(filename_renameat2(), etc.)
+Callers are adjusted - responsibility for dropping the filenames belongs
+to them now.

arch/alpha/kernel/osf_sys.c

@@ -454,42 +454,30 @@ static int
 osf_ufs_mount(const char __user *dirname,
 	      struct ufs_args __user *args, int flags)
 {
-	int retval;
-	struct cdfs_args tmp;
-	struct filename *devname;
+	struct ufs_args tmp;
+	char *devname __free(kfree) = NULL;
 
-	retval = -EFAULT;
 	if (copy_from_user(&tmp, args, sizeof(tmp)))
-		goto out;
-	devname = getname(tmp.devname);
-	retval = PTR_ERR(devname);
+		return -EFAULT;
+	devname = strndup_user(tmp.devname, PATH_MAX);
 	if (IS_ERR(devname))
-		goto out;
-	retval = do_mount(devname->name, dirname, "ext2", flags, NULL);
-	putname(devname);
- out:
-	return retval;
+		return PTR_ERR(devname);
+	return do_mount(devname, dirname, "ext2", flags, NULL);
 }
 
 static int
 osf_cdfs_mount(const char __user *dirname,
 	       struct cdfs_args __user *args, int flags)
 {
-	int retval;
 	struct cdfs_args tmp;
-	struct filename *devname;
+	char *devname __free(kfree) = NULL;
 
-	retval = -EFAULT;
 	if (copy_from_user(&tmp, args, sizeof(tmp)))
-		goto out;
-	devname = getname(tmp.devname);
-	retval = PTR_ERR(devname);
+		return -EFAULT;
+	devname = strndup_user(tmp.devname, PATH_MAX);
 	if (IS_ERR(devname))
-		goto out;
-	retval = do_mount(devname->name, dirname, "iso9660", flags, NULL);
-	putname(devname);
- out:
-	return retval;
+		return PTR_ERR(devname);
+	return do_mount(devname, dirname, "iso9660", flags, NULL);
 }
 
 static int

fs/coredump.c

@@ -895,11 +895,12 @@ static bool coredump_file(struct core_name *cn, struct coredump_params *cprm,
 	 * privs and don't want to unlink another user's coredump.
 	 */
 	if (!coredump_force_suid_safe(cprm)) {
+		CLASS(filename_kernel, name)(cn->corename);
 		/*
 		 * If it doesn't exist, that's fine. If there's some
 		 * other problem, we'll catch it at the filp_open().
 		 */
-		do_unlinkat(AT_FDCWD, getname_kernel(cn->corename));
+		filename_unlinkat(AT_FDCWD, name);
 	}
 
 	/*

fs/dcache.c

@@ -3297,10 +3297,6 @@ static void __init dcache_init(void)
 	runtime_const_init(ptr, dentry_hashtable);
 }
 
-/* SLAB cache for __getname() consumers */
-struct kmem_cache *names_cachep __ro_after_init;
-EXPORT_SYMBOL(names_cachep);
-
 void __init vfs_caches_init_early(void)
 {
 	int i;
@@ -3314,9 +3310,7 @@ void __init vfs_caches_init_early(void)
 
 void __init vfs_caches_init(void)
 {
-	names_cachep = kmem_cache_create_usercopy("names_cache", PATH_MAX, 0,
-			SLAB_HWCACHE_ALIGN|SLAB_PANIC, 0, PATH_MAX, NULL);
-
+	filename_init();
 	dcache_init();
 	inode_init();
 	files_init();