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

Pull vfs tmpfile updates from Al Viro:
 "Miklos' ->tmpfile() signature change; pass an unopened struct file to
  it, let it open the damn thing. Allows to add tmpfile support to FUSE"

* tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fuse: implement ->tmpfile()
  vfs: open inside ->tmpfile()
  vfs: move open right after ->tmpfile()
  vfs: make vfs_tmpfile() static
  ovl: use vfs_tmpfile_open() helper
  cachefiles: use vfs_tmpfile_open() helper
  cachefiles: only pass inode to *mark_inode_inuse() helpers
  cachefiles: tmpfile error handling cleanup
  hugetlbfs: cleanup mknod and tmpfile
  vfs: add vfs_tmpfile_open() helper

Documentation/filesystems/locking.rst

@@ -79,7 +79,8 @@ prototypes::
 	int (*atomic_open)(struct inode *, struct dentry *,
 				struct file *, unsigned open_flag,
 				umode_t create_mode);
-	int (*tmpfile) (struct inode *, struct dentry *, umode_t);
+	int (*tmpfile) (struct user_namespace *, struct inode *,
+			struct file *, umode_t);
 	int (*fileattr_set)(struct user_namespace *mnt_userns,
 			    struct dentry *dentry, struct fileattr *fa);
 	int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa);

Documentation/filesystems/porting.rst

@@ -933,3 +933,13 @@ to) and true - "keep going" (as 0 in old calling conventions).  Rationale:
 callers never looked at specific -E... values anyway.  ->iterate() and
 ->iterate_shared() instance require no changes at all, all filldir_t ones in
 the tree converted.
+
+---
+
+**mandatory**
+
+Calling conventions for ->tmpfile() have changed.  It now takes a struct
+file pointer instead of struct dentry pointer.  d_tmpfile() is similarly
+changed to simplify callers.  The passed file is in a non-open state and on
+success must be opened before returning (e.g. by calling
+finish_open_simple()).

Documentation/filesystems/vfs.rst

@@ -442,7 +442,7 @@ As of kernel 2.6.22, the following members are defined:
 		void (*update_time)(struct inode *, struct timespec *, int);
 		int (*atomic_open)(struct inode *, struct dentry *, struct file *,
 				   unsigned open_flag, umode_t create_mode);
-		int (*tmpfile) (struct user_namespace *, struct inode *, struct dentry *, umode_t);
+		int (*tmpfile) (struct user_namespace *, struct inode *, struct file *, umode_t);
 	        int (*set_acl)(struct user_namespace *, struct inode *, struct posix_acl *, int);
 		int (*fileattr_set)(struct user_namespace *mnt_userns,
 				    struct dentry *dentry, struct fileattr *fa);
@@ -592,7 +592,9 @@ otherwise noted.
 ``tmpfile``
 	called in the end of O_TMPFILE open().  Optional, equivalent to
 	atomically creating, opening and unlinking a file in given
-	directory.
+	directory.  On success needs to return with the file already
+	open; this can be done by calling finish_open_simple() right at
+	the end.
 
 ``fileattr_get``
 	called on ioctl(FS_IOC_GETFLAGS) and ioctl(FS_IOC_FSGETXATTR) to

fs/bad_inode.c

@@ -147,7 +147,7 @@ static int bad_inode_atomic_open(struct inode *inode, struct dentry *dentry,
 }
 
 static int bad_inode_tmpfile(struct user_namespace *mnt_userns,
-			     struct inode *inode, struct dentry *dentry,
+			     struct inode *inode, struct file *file,
 			     umode_t mode)
 {
 	return -EIO;

fs/btrfs/inode.c

@@ -10018,7 +10018,7 @@ static int btrfs_permission(struct user_namespace *mnt_userns,
 }
 
 static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-			 struct dentry *dentry, umode_t mode)
+			 struct file *file, umode_t mode)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 	struct btrfs_trans_handle *trans;
@@ -10026,7 +10026,7 @@ static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	struct inode *inode;
 	struct btrfs_new_inode_args new_inode_args = {
 		.dir = dir,
-		.dentry = dentry,
+		.dentry = file->f_path.dentry,
 		.orphan = true,
 	};
 	unsigned int trans_num_items;
@@ -10063,7 +10063,7 @@ static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	set_nlink(inode, 1);
 
 	if (!ret) {
-		d_tmpfile(dentry, inode);
+		d_tmpfile(file, inode);
 		unlock_new_inode(inode);
 		mark_inode_dirty(inode);
 	}
@@ -10075,7 +10075,7 @@ static int btrfs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 out_inode:
 	if (ret)
 		iput(inode);
-	return ret;
+	return finish_open_simple(file, ret);
 }
 
 void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)

fs/cachefiles/namei.c

@@ -15,9 +15,8 @@
  * file or directory.  The caller must hold the inode lock.
  */
 static bool __cachefiles_mark_inode_in_use(struct cachefiles_object *object,
-					   struct dentry *dentry)
+					   struct inode *inode)
 {
-	struct inode *inode = d_backing_inode(dentry);
 	bool can_use = false;
 
 	if (!(inode->i_flags & S_KERNEL_FILE)) {
@@ -26,21 +25,18 @@ static bool __cachefiles_mark_inode_in_use(struct cachefiles_object *object,
 		can_use = true;
 	} else {
 		trace_cachefiles_mark_failed(object, inode);
-		pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n",
-			  dentry, inode->i_ino);
 	}
 
 	return can_use;
 }
 
 static bool cachefiles_mark_inode_in_use(struct cachefiles_object *object,
-					 struct dentry *dentry)
+					 struct inode *inode)
 {
-	struct inode *inode = d_backing_inode(dentry);
 	bool can_use;
 
 	inode_lock(inode);
-	can_use = __cachefiles_mark_inode_in_use(object, dentry);
+	can_use = __cachefiles_mark_inode_in_use(object, inode);
 	inode_unlock(inode);
 	return can_use;
 }
@@ -49,21 +45,17 @@ static bool cachefiles_mark_inode_in_use(struct cachefiles_object *object,
  * Unmark a backing inode.  The caller must hold the inode lock.
  */
 static void __cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
-					     struct dentry *dentry)
+					     struct inode *inode)
 {
-	struct inode *inode = d_backing_inode(dentry);
-
 	inode->i_flags &= ~S_KERNEL_FILE;
 	trace_cachefiles_mark_inactive(object, inode);
 }
 
 static void cachefiles_do_unmark_inode_in_use(struct cachefiles_object *object,
-					      struct dentry *dentry)
+					      struct inode *inode)
 {
-	struct inode *inode = d_backing_inode(dentry);
-
 	inode_lock(inode);
-	__cachefiles_unmark_inode_in_use(object, dentry);
+	__cachefiles_unmark_inode_in_use(object, inode);
 	inode_unlock(inode);
 }
 
@@ -77,14 +69,12 @@ void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
 	struct cachefiles_cache *cache = object->volume->cache;
 	struct inode *inode = file_inode(file);
 
-	if (inode) {
-		cachefiles_do_unmark_inode_in_use(object, file->f_path.dentry);
+	cachefiles_do_unmark_inode_in_use(object, inode);
 
-		if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {
-			atomic_long_add(inode->i_blocks, &cache->b_released);
-			if (atomic_inc_return(&cache->f_released))
-				cachefiles_state_changed(cache);
-		}
+	if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {
+		atomic_long_add(inode->i_blocks, &cache->b_released);
+		if (atomic_inc_return(&cache->f_released))
+			cachefiles_state_changed(cache);
 	}
 }
 
@@ -164,8 +154,11 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 	inode_lock(d_inode(subdir));
 	inode_unlock(d_inode(dir));
 
-	if (!__cachefiles_mark_inode_in_use(NULL, subdir))
+	if (!__cachefiles_mark_inode_in_use(NULL, d_inode(subdir))) {
+		pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n",
+			  subdir, d_inode(subdir)->i_ino);
 		goto mark_error;
+	}
 
 	inode_unlock(d_inode(subdir));
 
@@ -224,9 +217,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 void cachefiles_put_directory(struct dentry *dir)
 {
 	if (dir) {
-		inode_lock(dir->d_inode);
-		__cachefiles_unmark_inode_in_use(NULL, dir);
-		inode_unlock(dir->d_inode);
+		cachefiles_do_unmark_inode_in_use(NULL, d_inode(dir));
 		dput(dir);
 	}
 }
@@ -410,7 +401,7 @@ int cachefiles_bury_object(struct cachefiles_cache *cache,
 					    "Rename failed with error %d", ret);
 	}
 
-	__cachefiles_unmark_inode_in_use(object, rep);
+	__cachefiles_unmark_inode_in_use(object, d_inode(rep));
 	unlock_rename(cache->graveyard, dir);
 	dput(grave);
 	_leave(" = 0");
@@ -451,84 +442,72 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
 	const struct cred *saved_cred;
 	struct dentry *fan = volume->fanout[(u8)object->cookie->key_hash];
 	struct file *file;
-	struct path path;
+	const struct path parentpath = { .mnt = cache->mnt, .dentry = fan };
 	uint64_t ni_size;
 	long ret;
 
 
 	cachefiles_begin_secure(cache, &saved_cred);
 
-	path.mnt = cache->mnt;
 	ret = cachefiles_inject_write_error();
-	if (ret == 0)
-		path.dentry = vfs_tmpfile(&init_user_ns, fan, S_IFREG, O_RDWR);
-	else
-		path.dentry = ERR_PTR(ret);
-	if (IS_ERR(path.dentry)) {
-		trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(path.dentry),
+	if (ret == 0) {
+		file = vfs_tmpfile_open(&init_user_ns, &parentpath, S_IFREG,
+					O_RDWR | O_LARGEFILE | O_DIRECT,
+					cache->cache_cred);
+		ret = PTR_ERR_OR_ZERO(file);
+	}
+	if (ret) {
+		trace_cachefiles_vfs_error(object, d_inode(fan), ret,
 					   cachefiles_trace_tmpfile_error);
-		if (PTR_ERR(path.dentry) == -EIO)
+		if (ret == -EIO)
 			cachefiles_io_error_obj(object, "Failed to create tmpfile");
-		file = ERR_CAST(path.dentry);
-		goto out;
+		goto err;
 	}
 
-	trace_cachefiles_tmpfile(object, d_backing_inode(path.dentry));
+	trace_cachefiles_tmpfile(object, file_inode(file));
 
-	if (!cachefiles_mark_inode_in_use(object, path.dentry)) {
-		file = ERR_PTR(-EBUSY);
-		goto out_dput;
-	}
+	/* This is a newly created file with no other possible user */
+	if (!cachefiles_mark_inode_in_use(object, file_inode(file)))
+		WARN_ON(1);
 
 	ret = cachefiles_ondemand_init_object(object);
-	if (ret < 0) {
-		file = ERR_PTR(ret);
-		goto out_unuse;
-	}
+	if (ret < 0)
+		goto err_unuse;
 
 	ni_size = object->cookie->object_size;
 	ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE);
 
 	if (ni_size > 0) {
-		trace_cachefiles_trunc(object, d_backing_inode(path.dentry), 0, ni_size,
+		trace_cachefiles_trunc(object, file_inode(file), 0, ni_size,
 				       cachefiles_trunc_expand_tmpfile);
 		ret = cachefiles_inject_write_error();
 		if (ret == 0)
-			ret = vfs_truncate(&path, ni_size);
+			ret = vfs_truncate(&file->f_path, ni_size);
 		if (ret < 0) {
 			trace_cachefiles_vfs_error(
-				object, d_backing_inode(path.dentry), ret,
+				object, file_inode(file), ret,
 				cachefiles_trace_trunc_error);
-			file = ERR_PTR(ret);
-			goto out_unuse;
+			goto err_unuse;
 		}
 	}
 
-	file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT,
-				   d_backing_inode(path.dentry), cache->cache_cred);
-	if (IS_ERR(file)) {
-		trace_cachefiles_vfs_error(object, d_backing_inode(path.dentry),
-					   PTR_ERR(file),
-					   cachefiles_trace_open_error);
-		goto out_unuse;
-	}
+	ret = -EINVAL;
 	if (unlikely(!file->f_op->read_iter) ||
 	    unlikely(!file->f_op->write_iter)) {
 		fput(file);
 		pr_notice("Cache does not support read_iter and write_iter\n");
-		file = ERR_PTR(-EINVAL);
-		goto out_unuse;
+		goto err_unuse;
 	}
-
-	goto out_dput;
-
-out_unuse:
-	cachefiles_do_unmark_inode_in_use(object, path.dentry);
-out_dput:
-	dput(path.dentry);
 out:
 	cachefiles_end_secure(cache, saved_cred);
 	return file;
+
+err_unuse:
+	cachefiles_do_unmark_inode_in_use(object, file_inode(file));
+	fput(file);
+err:
+	file = ERR_PTR(ret);
+	goto out;
 }
 
 /*
@@ -569,8 +548,11 @@ static bool cachefiles_open_file(struct cachefiles_object *object,
 
 	_enter("%pd", dentry);
 
-	if (!cachefiles_mark_inode_in_use(object, dentry))
+	if (!cachefiles_mark_inode_in_use(object, d_inode(dentry))) {
+		pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n",
+			  dentry, d_inode(dentry)->i_ino);
 		return false;
+	}
 
 	/* We need to open a file interface onto a data file now as we can't do
 	 * it on demand because writeback called from do_exit() sees
@@ -624,7 +606,7 @@ static bool cachefiles_open_file(struct cachefiles_object *object,
 error_fput:
 	fput(file);
 error:
-	cachefiles_do_unmark_inode_in_use(object, dentry);
+	cachefiles_do_unmark_inode_in_use(object, d_inode(dentry));
 	dput(dentry);
 	return false;
 }

fs/dcache.c

@@ -3249,8 +3249,10 @@ void d_genocide(struct dentry *parent)
 
 EXPORT_SYMBOL(d_genocide);
 
-void d_tmpfile(struct dentry *dentry, struct inode *inode)
+void d_tmpfile(struct file *file, struct inode *inode)
 {
+	struct dentry *dentry = file->f_path.dentry;
+
 	inode_dec_link_count(inode);
 	BUG_ON(dentry->d_name.name != dentry->d_iname ||
 		!hlist_unhashed(&dentry->d_u.d_alias) ||

fs/ext2/namei.c

@@ -120,7 +120,7 @@ static int ext2_create (struct user_namespace * mnt_userns,
 }
 
 static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-			struct dentry *dentry, umode_t mode)
+			struct file *file, umode_t mode)
 {
 	struct inode *inode = ext2_new_inode(dir, mode, NULL);
 	if (IS_ERR(inode))
@@ -128,9 +128,9 @@ static int ext2_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 
 	ext2_set_file_ops(inode);
 	mark_inode_dirty(inode);
-	d_tmpfile(dentry, inode);
+	d_tmpfile(file, inode);
 	unlock_new_inode(inode);
-	return 0;
+	return finish_open_simple(file, 0);
 }
 
 static int ext2_mknod (struct user_namespace * mnt_userns, struct inode * dir,

fs/ext4/namei.c

@@ -2854,7 +2854,7 @@ static int ext4_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-			struct dentry *dentry, umode_t mode)
+			struct file *file, umode_t mode)
 {
 	handle_t *handle;
 	struct inode *inode;
@@ -2876,7 +2876,7 @@ static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 		inode->i_op = &ext4_file_inode_operations;
 		inode->i_fop = &ext4_file_operations;
 		ext4_set_aops(inode);
-		d_tmpfile(dentry, inode);
+		d_tmpfile(file, inode);
 		err = ext4_orphan_add(handle, inode);
 		if (err)
 			goto err_unlock_inode;
@@ -2887,7 +2887,7 @@ static int ext4_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 		ext4_journal_stop(handle);
 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
 		goto retry;
-	return err;
+	return finish_open_simple(file, err);
 err_unlock_inode:
 	ext4_journal_stop(handle);
 	unlock_new_inode(inode);

fs/f2fs/namei.c

@@ -845,7 +845,7 @@ static int f2fs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 static int __f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-			  struct dentry *dentry, umode_t mode, bool is_whiteout,
+			  struct file *file, umode_t mode, bool is_whiteout,
 			  struct inode **new_inode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
@@ -892,8 +892,8 @@ static int __f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 		inode->i_state |= I_LINKABLE;
 		spin_unlock(&inode->i_lock);
 	} else {
-		if (dentry)
-			d_tmpfile(dentry, inode);
+		if (file)
+			d_tmpfile(file, inode);
 		else
 			f2fs_i_links_write(inode, false);
 	}
@@ -915,16 +915,19 @@ static int __f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 static int f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-			struct dentry *dentry, umode_t mode)
+			struct file *file, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
+	int err;
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
 	if (!f2fs_is_checkpoint_ready(sbi))
 		return -ENOSPC;
 
-	return __f2fs_tmpfile(mnt_userns, dir, dentry, mode, false, NULL);
+	err = __f2fs_tmpfile(mnt_userns, dir, file, mode, false, NULL);
+
+	return finish_open_simple(file, err);
 }
 
 static int f2fs_create_whiteout(struct user_namespace *mnt_userns,

fs/fuse/dir.c

@@ -529,7 +529,7 @@ static int get_security_context(struct dentry *entry, umode_t mode,
  */
 static int fuse_create_open(struct inode *dir, struct dentry *entry,
 			    struct file *file, unsigned int flags,
-			    umode_t mode)
+			    umode_t mode, u32 opcode)
 {
 	int err;
 	struct inode *inode;
@@ -573,7 +573,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 		inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID;
 	}
 
-	args.opcode = FUSE_CREATE;
+	args.opcode = opcode;
 	args.nodeid = get_node_id(dir);
 	args.in_numargs = 2;
 	args.in_args[0].size = sizeof(inarg);
@@ -676,7 +676,7 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 	if (fc->no_create)
 		goto mknod;
 
-	err = fuse_create_open(dir, entry, file, flags, mode);
+	err = fuse_create_open(dir, entry, file, flags, mode, FUSE_CREATE);
 	if (err == -ENOSYS) {
 		fc->no_create = 1;
 		goto mknod;
@@ -802,6 +802,23 @@ static int fuse_create(struct user_namespace *mnt_userns, struct inode *dir,
 	return fuse_mknod(&init_user_ns, dir, entry, mode, 0);
 }
 
+static int fuse_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+			struct file *file, umode_t mode)
+{
+	struct fuse_conn *fc = get_fuse_conn(dir);
+	int err;
+
+	if (fc->no_tmpfile)
+		return -EOPNOTSUPP;
+
+	err = fuse_create_open(dir, file->f_path.dentry, file, file->f_flags, mode, FUSE_TMPFILE);
+	if (err == -ENOSYS) {
+		fc->no_tmpfile = 1;
+		err = -EOPNOTSUPP;
+	}
+	return err;
+}
+
 static int fuse_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 		      struct dentry *entry, umode_t mode)
 {
@@ -1913,6 +1930,7 @@ static const struct inode_operations fuse_dir_inode_operations = {
 	.setattr	= fuse_setattr,
 	.create		= fuse_create,
 	.atomic_open	= fuse_atomic_open,
+	.tmpfile	= fuse_tmpfile,
 	.mknod		= fuse_mknod,
 	.permission	= fuse_permission,
 	.getattr	= fuse_getattr,

fs/fuse/fuse_i.h

@@ -784,6 +784,9 @@ struct fuse_conn {
 	/* Does the filesystem support per inode DAX? */
 	unsigned int inode_dax:1;
 
+	/* Is tmpfile not implemented by fs? */
+	unsigned int no_tmpfile:1;
+
 	/** The number of requests waiting for completion */
 	atomic_t num_waiting;
 

fs/hugetlbfs/inode.c

@@ -1013,33 +1013,18 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 /*
  * File creation. Allocate an inode, and we're done..
  */
-static int do_hugetlbfs_mknod(struct inode *dir,
-			struct dentry *dentry,
-			umode_t mode,
-			dev_t dev,
-			bool tmpfile)
+static int hugetlbfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+			   struct dentry *dentry, umode_t mode, dev_t dev)
 {
 	struct inode *inode;
-	int error = -ENOSPC;
 
 	inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
-	if (inode) {
-		dir->i_ctime = dir->i_mtime = current_time(dir);
-		if (tmpfile) {
-			d_tmpfile(dentry, inode);
-		} else {
-			d_instantiate(dentry, inode);
-			dget(dentry);/* Extra count - pin the dentry in core */
-		}
-		error = 0;
-	}
-	return error;
-}
-
-static int hugetlbfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
-			   struct dentry *dentry, umode_t mode, dev_t dev)
-{
-	return do_hugetlbfs_mknod(dir, dentry, mode, dev, false);
+	if (!inode)
+		return -ENOSPC;
+	dir->i_ctime = dir->i_mtime = current_time(dir);
+	d_instantiate(dentry, inode);
+	dget(dentry);/* Extra count - pin the dentry in core */
+	return 0;
 }
 
 static int hugetlbfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
@@ -1060,10 +1045,17 @@ static int hugetlbfs_create(struct user_namespace *mnt_userns,
 }
 
 static int hugetlbfs_tmpfile(struct user_namespace *mnt_userns,
-			     struct inode *dir, struct dentry *dentry,
+			     struct inode *dir, struct file *file,
 			     umode_t mode)
 {
-	return do_hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0, true);
+	struct inode *inode;
+
+	inode = hugetlbfs_get_inode(dir->i_sb, dir, mode | S_IFREG, 0);
+	if (!inode)
+		return -ENOSPC;
+	dir->i_ctime = dir->i_mtime = current_time(dir);
+	d_tmpfile(file, inode);
+	return finish_open_simple(file, 0);
 }
 
 static int hugetlbfs_symlink(struct user_namespace *mnt_userns,

fs/minix/namei.c

@@ -53,16 +53,16 @@ static int minix_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 static int minix_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-			 struct dentry *dentry, umode_t mode)
+			 struct file *file, umode_t mode)
 {
 	int error;
 	struct inode *inode = minix_new_inode(dir, mode, &error);
 	if (inode) {
 		minix_set_inode(inode, 0);
 		mark_inode_dirty(inode);
-		d_tmpfile(dentry, inode);
+		d_tmpfile(file, inode);
 	}
-	return error;
+	return finish_open_simple(file, error);
 }
 
 static int minix_create(struct user_namespace *mnt_userns, struct inode *dir,

fs/namei.c

@@ -3583,72 +3583,94 @@ static int do_open(struct nameidata *nd,
  * On non-idmapped mounts or if permission checking is to be performed on the
  * raw inode simply passs init_user_ns.
  */
-struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns,
-			   struct dentry *dentry, umode_t mode, int open_flag)
+static int vfs_tmpfile(struct user_namespace *mnt_userns,
+		       const struct path *parentpath,
+		       struct file *file, umode_t mode)
 {
-	struct dentry *child = NULL;
-	struct inode *dir = dentry->d_inode;
+	struct dentry *child;
+	struct inode *dir = d_inode(parentpath->dentry);
 	struct inode *inode;
 	int error;
 
 	/* we want directory to be writable */
 	error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
 	if (error)
-		goto out_err;
-	error = -EOPNOTSUPP;
+		return error;
 	if (!dir->i_op->tmpfile)
-		goto out_err;
-	error = -ENOMEM;
-	child = d_alloc(dentry, &slash_name);
+		return -EOPNOTSUPP;
+	child = d_alloc(parentpath->dentry, &slash_name);
 	if (unlikely(!child))
-		goto out_err;
+		return -ENOMEM;
+	file->f_path.mnt = parentpath->mnt;
+	file->f_path.dentry = child;
 	mode = vfs_prepare_mode(mnt_userns, dir, mode, mode, mode);
-	error = dir->i_op->tmpfile(mnt_userns, dir, child, mode);
+	error = dir->i_op->tmpfile(mnt_userns, dir, file, mode);
+	dput(child);
 	if (error)
-		goto out_err;
-	error = -ENOENT;
-	inode = child->d_inode;
-	if (unlikely(!inode))
-		goto out_err;
-	if (!(open_flag & O_EXCL)) {
+		return error;
+	/* Don't check for other permissions, the inode was just created */
+	error = may_open(mnt_userns, &file->f_path, 0, file->f_flags);
+	if (error)
+		return error;
+	inode = file_inode(file);
+	if (!(file->f_flags & O_EXCL)) {
 		spin_lock(&inode->i_lock);
 		inode->i_state |= I_LINKABLE;
 		spin_unlock(&inode->i_lock);
 	}
 	ima_post_create_tmpfile(mnt_userns, inode);
-	return child;
+	return 0;
+}
 
-out_err:
-	dput(child);
-	return ERR_PTR(error);
+/**
+ * vfs_tmpfile_open - open a tmpfile for kernel internal use
+ * @mnt_userns:	user namespace of the mount the inode was found from
+ * @parentpath:	path of the base directory
+ * @mode:	mode of the new tmpfile
+ * @open_flag:	flags
+ * @cred:	credentials for open
+ *
+ * Create and open a temporary file.  The file is not accounted in nr_files,
+ * hence this is only for kernel internal use, and must not be installed into
+ * file tables or such.
+ */
+struct file *vfs_tmpfile_open(struct user_namespace *mnt_userns,
+			  const struct path *parentpath,
+			  umode_t mode, int open_flag, const struct cred *cred)
+{
+	struct file *file;
+	int error;
+
+	file = alloc_empty_file_noaccount(open_flag, cred);
+	if (!IS_ERR(file)) {
+		error = vfs_tmpfile(mnt_userns, parentpath, file, mode);
+		if (error) {
+			fput(file);
+			file = ERR_PTR(error);
+		}
+	}
+	return file;
 }
-EXPORT_SYMBOL(vfs_tmpfile);
+EXPORT_SYMBOL(vfs_tmpfile_open);
 
 static int do_tmpfile(struct nameidata *nd, unsigned flags,
 		const struct open_flags *op,
 		struct file *file)
 {
 	struct user_namespace *mnt_userns;
-	struct dentry *child;
 	struct path path;
 	int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);
+
 	if (unlikely(error))
 		return error;
 	error = mnt_want_write(path.mnt);
 	if (unlikely(error))
 		goto out;
 	mnt_userns = mnt_user_ns(path.mnt);
-	child = vfs_tmpfile(mnt_userns, path.dentry, op->mode, op->open_flag);
-	error = PTR_ERR(child);
-	if (IS_ERR(child))
+	error = vfs_tmpfile(mnt_userns, &path, file, op->mode);
+	if (error)
 		goto out2;
-	dput(path.dentry);
-	path.dentry = child;
-	audit_inode(nd->name, child, 0);
-	/* Don't check for other permissions, the inode was just created */
-	error = may_open(mnt_userns, &path, 0, op->open_flag);
-	if (!error)
-		error = vfs_open(&path, file);
+	audit_inode(nd->name, file->f_path.dentry, 0);
 out2:
 	mnt_drop_write(path.mnt);
 out:

fs/overlayfs/copy_up.c

@@ -193,11 +193,11 @@ static int ovl_copy_fileattr(struct inode *inode, const struct path *old,
 	return ovl_real_fileattr_set(new, &newfa);
 }
 
-static int ovl_copy_up_data(struct ovl_fs *ofs, const struct path *old,
-			    const struct path *new, loff_t len)
+static int ovl_copy_up_file(struct ovl_fs *ofs, struct dentry *dentry,
+			    struct file *new_file, loff_t len)
 {
+	struct path datapath;
 	struct file *old_file;
-	struct file *new_file;
 	loff_t old_pos = 0;
 	loff_t new_pos = 0;
 	loff_t cloned;
@@ -206,23 +206,18 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, const struct path *old,
 	bool skip_hole = false;
 	int error = 0;
 
-	if (len == 0)
-		return 0;
+	ovl_path_lowerdata(dentry, &datapath);
+	if (WARN_ON(datapath.dentry == NULL))
+		return -EIO;
 
-	old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY);
+	old_file = ovl_path_open(&datapath, O_LARGEFILE | O_RDONLY);
 	if (IS_ERR(old_file))
 		return PTR_ERR(old_file);
 
-	new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY);
-	if (IS_ERR(new_file)) {
-		error = PTR_ERR(new_file);
-		goto out_fput;
-	}
-
 	/* Try to use clone_file_range to clone up within the same fs */
 	cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0);
 	if (cloned == len)
-		goto out;
+		goto out_fput;
 	/* Couldn't clone, so now we try to copy the data */
 
 	/* Check if lower fs supports seek operation */
@@ -282,10 +277,8 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, const struct path *old,
 
 		len -= bytes;
 	}
-out:
 	if (!error && ovl_should_sync(ofs))
 		error = vfs_fsync(new_file, 0);
-	fput(new_file);
 out_fput:
 	fput(old_file);
 	return error;
@@ -556,30 +549,31 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c)
 	return err;
 }
 
-static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
+static int ovl_copy_up_data(struct ovl_copy_up_ctx *c, const struct path *temp)
 {
 	struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
-	struct inode *inode = d_inode(c->dentry);
-	struct path upperpath, datapath;
+	struct file *new_file;
 	int err;
 
-	ovl_path_upper(c->dentry, &upperpath);
-	if (WARN_ON(upperpath.dentry != NULL))
-		return -EIO;
+	if (!S_ISREG(c->stat.mode) || c->metacopy || !c->stat.size)
+		return 0;
 
-	upperpath.dentry = temp;
+	new_file = ovl_path_open(temp, O_LARGEFILE | O_WRONLY);
+	if (IS_ERR(new_file))
+		return PTR_ERR(new_file);
 
-	/*
-	 * Copy up data first and then xattrs. Writing data after
-	 * xattrs will remove security.capability xattr automatically.
-	 */
-	if (S_ISREG(c->stat.mode) && !c->metacopy) {
-		ovl_path_lowerdata(c->dentry, &datapath);
-		err = ovl_copy_up_data(ofs, &datapath, &upperpath,
-				       c->stat.size);
-		if (err)
-			return err;
-	}
+	err = ovl_copy_up_file(ofs, c->dentry, new_file, c->stat.size);
+	fput(new_file);
+
+	return err;
+}
+
+static int ovl_copy_up_metadata(struct ovl_copy_up_ctx *c, struct dentry *temp)
+{
+	struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
+	struct inode *inode = d_inode(c->dentry);
+	struct path upperpath = { .mnt = ovl_upper_mnt(ofs), .dentry = temp };
+	int err;
 
 	err = ovl_copy_xattr(c->dentry->d_sb, &c->lowerpath, temp);
 	if (err)
@@ -662,6 +656,7 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c)
 	struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
 	struct inode *inode;
 	struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir);
+	struct path path = { .mnt = ovl_upper_mnt(ofs) };
 	struct dentry *temp, *upper;
 	struct ovl_cu_creds cc;
 	int err;
@@ -688,7 +683,16 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c)
 	if (IS_ERR(temp))
 		goto unlock;
 
-	err = ovl_copy_up_inode(c, temp);
+	/*
+	 * Copy up data first and then xattrs. Writing data after
+	 * xattrs will remove security.capability xattr automatically.
+	 */
+	path.dentry = temp;
+	err = ovl_copy_up_data(c, &path);
+	if (err)
+		goto cleanup;
+
+	err = ovl_copy_up_metadata(c, temp);
 	if (err)
 		goto cleanup;
 
@@ -732,6 +736,7 @@ static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c)
 	struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
 	struct inode *udir = d_inode(c->destdir);
 	struct dentry *temp, *upper;
+	struct file *tmpfile;
 	struct ovl_cu_creds cc;
 	int err;
 
@@ -739,15 +744,22 @@ static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c)
 	if (err)
 		return err;
 
-	temp = ovl_do_tmpfile(ofs, c->workdir, c->stat.mode);
+	tmpfile = ovl_do_tmpfile(ofs, c->workdir, c->stat.mode);
 	ovl_revert_cu_creds(&cc);
 
-	if (IS_ERR(temp))
-		return PTR_ERR(temp);
+	if (IS_ERR(tmpfile))
+		return PTR_ERR(tmpfile);
 
-	err = ovl_copy_up_inode(c, temp);
+	temp = tmpfile->f_path.dentry;
+	if (!c->metacopy && c->stat.size) {
+		err = ovl_copy_up_file(ofs, c->dentry, tmpfile, c->stat.size);
+		if (err)
+			return err;
+	}
+
+	err = ovl_copy_up_metadata(c, temp);
 	if (err)
-		goto out_dput;
+		goto out_fput;
 
 	inode_lock_nested(udir, I_MUTEX_PARENT);
 
@@ -761,16 +773,14 @@ static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c)
 	inode_unlock(udir);
 
 	if (err)
-		goto out_dput;
+		goto out_fput;
 
 	if (!c->metacopy)
 		ovl_set_upperdata(d_inode(c->dentry));
-	ovl_inode_update(d_inode(c->dentry), temp);
+	ovl_inode_update(d_inode(c->dentry), dget(temp));
 
-	return 0;
-
-out_dput:
-	dput(temp);
+out_fput:
+	fput(tmpfile);
 	return err;
 }
 
@@ -899,7 +909,7 @@ static ssize_t ovl_getxattr_value(const struct path *path, char *name, char **va
 static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c)
 {
 	struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
-	struct path upperpath, datapath;
+	struct path upperpath;
 	int err;
 	char *capability = NULL;
 	ssize_t cap_size;
@@ -908,10 +918,6 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c)
 	if (WARN_ON(upperpath.dentry == NULL))
 		return -EIO;
 
-	ovl_path_lowerdata(c->dentry, &datapath);
-	if (WARN_ON(datapath.dentry == NULL))
-		return -EIO;
-
 	if (c->stat.size) {
 		err = cap_size = ovl_getxattr_value(&upperpath, XATTR_NAME_CAPS,
 						    &capability);
@@ -919,7 +925,7 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c)
 			goto out;
 	}
 
-	err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size);
+	err = ovl_copy_up_data(c, &upperpath);
 	if (err)
 		goto out_free;
 

fs/overlayfs/overlayfs.h

@@ -310,14 +310,16 @@ static inline int ovl_do_whiteout(struct ovl_fs *ofs,
 	return err;
 }
 
-static inline struct dentry *ovl_do_tmpfile(struct ovl_fs *ofs,
-					    struct dentry *dentry, umode_t mode)
+static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs,
+					  struct dentry *dentry, umode_t mode)
 {
-	struct dentry *ret = vfs_tmpfile(ovl_upper_mnt_userns(ofs), dentry, mode, 0);
-	int err = PTR_ERR_OR_ZERO(ret);
+	struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry };
+	struct file *file = vfs_tmpfile_open(ovl_upper_mnt_userns(ofs), &path, mode,
+					O_LARGEFILE | O_WRONLY, current_cred());
+	int err = PTR_ERR_OR_ZERO(file);
 
 	pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
-	return ret;
+	return file;
 }
 
 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,

fs/overlayfs/super.c

@@ -15,6 +15,7 @@
 #include <linux/seq_file.h>
 #include <linux/posix_acl_xattr.h>
 #include <linux/exportfs.h>
+#include <linux/file.h>
 #include "overlayfs.h"
 
 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
@@ -1369,7 +1370,8 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
 			    const struct path *workpath)
 {
 	struct vfsmount *mnt = ovl_upper_mnt(ofs);
-	struct dentry *temp, *workdir;
+	struct dentry *workdir;
+	struct file *tmpfile;
 	bool rename_whiteout;
 	bool d_type;
 	int fh_type;
@@ -1405,10 +1407,10 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
 		pr_warn("upper fs needs to support d_type.\n");
 
 	/* Check if upper/work fs supports O_TMPFILE */
-	temp = ovl_do_tmpfile(ofs, ofs->workdir, S_IFREG | 0);
-	ofs->tmpfile = !IS_ERR(temp);
+	tmpfile = ovl_do_tmpfile(ofs, ofs->workdir, S_IFREG | 0);
+	ofs->tmpfile = !IS_ERR(tmpfile);
 	if (ofs->tmpfile)
-		dput(temp);
+		fput(tmpfile);
 	else
 		pr_warn("upper fs does not support tmpfile.\n");
 

fs/ramfs/inode.c

@@ -146,15 +146,15 @@ static int ramfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 static int ramfs_tmpfile(struct user_namespace *mnt_userns,
-			 struct inode *dir, struct dentry *dentry, umode_t mode)
+			 struct inode *dir, struct file *file, umode_t mode)
 {
 	struct inode *inode;
 
 	inode = ramfs_get_inode(dir->i_sb, dir, mode, 0);
 	if (!inode)
 		return -ENOSPC;
-	d_tmpfile(dentry, inode);
-	return 0;
+	d_tmpfile(file, inode);
+	return finish_open_simple(file, 0);
 }
 
 static const struct inode_operations ramfs_dir_inode_operations = {

fs/ubifs/dir.c

@@ -424,8 +424,9 @@ static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
 }
 
 static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-			 struct dentry *dentry, umode_t mode)
+			 struct file *file, umode_t mode)
 {
+	struct dentry *dentry = file->f_path.dentry;
 	struct inode *inode;
 	struct ubifs_info *c = dir->i_sb->s_fs_info;
 	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
@@ -475,7 +476,7 @@ static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 
 	mutex_lock(&ui->ui_mutex);
 	insert_inode_hash(inode);
-	d_tmpfile(dentry, inode);
+	d_tmpfile(file, inode);
 	ubifs_assert(c, ui->dirty);
 
 	instantiated = 1;
@@ -489,7 +490,7 @@ static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 
 	ubifs_release_budget(c, &req);
 
-	return 0;
+	return finish_open_simple(file, 0);
 
 out_cancel:
 	unlock_2_inodes(dir, inode);

fs/udf/namei.c

@@ -626,7 +626,7 @@ static int udf_create(struct user_namespace *mnt_userns, struct inode *dir,
 }
 
 static int udf_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-		       struct dentry *dentry, umode_t mode)
+		       struct file *file, umode_t mode)
 {
 	struct inode *inode = udf_new_inode(dir, mode);
 
@@ -640,9 +640,9 @@ static int udf_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	inode->i_op = &udf_file_inode_operations;
 	inode->i_fop = &udf_file_operations;
 	mark_inode_dirty(inode);
-	d_tmpfile(dentry, inode);
+	d_tmpfile(file, inode);
 	unlock_new_inode(inode);
-	return 0;
+	return finish_open_simple(file, 0);
 }
 
 static int udf_mknod(struct user_namespace *mnt_userns, struct inode *dir,

fs/xfs/xfs_iops.c

@@ -167,7 +167,7 @@ xfs_generic_create(
 	struct dentry	*dentry,
 	umode_t		mode,
 	dev_t		rdev,
-	bool		tmpfile)	/* unnamed file */
+	struct file	*tmpfile)	/* unnamed file */
 {
 	struct inode	*inode;
 	struct xfs_inode *ip = NULL;
@@ -234,7 +234,7 @@ xfs_generic_create(
 		 * d_tmpfile can immediately set it back to zero.
 		 */
 		set_nlink(inode, 1);
-		d_tmpfile(dentry, inode);
+		d_tmpfile(tmpfile, inode);
 	} else
 		d_instantiate(dentry, inode);
 
@@ -261,7 +261,7 @@ xfs_vn_mknod(
 	umode_t			mode,
 	dev_t			rdev)
 {
-	return xfs_generic_create(mnt_userns, dir, dentry, mode, rdev, false);
+	return xfs_generic_create(mnt_userns, dir, dentry, mode, rdev, NULL);
 }
 
 STATIC int
@@ -272,7 +272,7 @@ xfs_vn_create(
 	umode_t			mode,
 	bool			flags)
 {
-	return xfs_generic_create(mnt_userns, dir, dentry, mode, 0, false);
+	return xfs_generic_create(mnt_userns, dir, dentry, mode, 0, NULL);
 }
 
 STATIC int
@@ -283,7 +283,7 @@ xfs_vn_mkdir(
 	umode_t			mode)
 {
 	return xfs_generic_create(mnt_userns, dir, dentry, mode | S_IFDIR, 0,
-				  false);
+				  NULL);
 }
 
 STATIC struct dentry *
@@ -1090,10 +1090,12 @@ STATIC int
 xfs_vn_tmpfile(
 	struct user_namespace	*mnt_userns,
 	struct inode		*dir,
-	struct dentry		*dentry,
+	struct file		*file,
 	umode_t			mode)
 {
-	return xfs_generic_create(mnt_userns, dir, dentry, mode, 0, true);
+	int err = xfs_generic_create(mnt_userns, dir, file->f_path.dentry, mode, 0, file);
+
+	return finish_open_simple(file, err);
 }
 
 static const struct inode_operations xfs_inode_operations = {

include/linux/dcache.h

@@ -16,6 +16,7 @@
 #include <linux/wait.h>
 
 struct path;
+struct file;
 struct vfsmount;
 
 /*
@@ -250,7 +251,7 @@ extern struct dentry * d_make_root(struct inode *);
 /* <clickety>-<click> the ramfs-type tree */
 extern void d_genocide(struct dentry *);
 
-extern void d_tmpfile(struct dentry *, struct inode *);
+extern void d_tmpfile(struct file *, struct inode *);
 
 extern struct dentry *d_find_alias(struct inode *);
 extern void d_prune_aliases(struct inode *);

include/linux/fs.h

@@ -2004,8 +2004,9 @@ static inline int vfs_whiteout(struct user_namespace *mnt_userns,
 			 WHITEOUT_DEV);
 }
 
-struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns,
-			   struct dentry *dentry, umode_t mode, int open_flag);
+struct file *vfs_tmpfile_open(struct user_namespace *mnt_userns,
+			const struct path *parentpath,
+			umode_t mode, int open_flag, const struct cred *cred);
 
 int vfs_mkobj(struct dentry *, umode_t,
 		int (*f)(struct dentry *, umode_t, void *),
@@ -2170,7 +2171,7 @@ struct inode_operations {
 			   struct file *, unsigned open_flag,
 			   umode_t create_mode);
 	int (*tmpfile) (struct user_namespace *, struct inode *,
-			struct dentry *, umode_t);
+			struct file *, umode_t);
 	int (*set_acl)(struct user_namespace *, struct inode *,
 		       struct posix_acl *, int);
 	int (*fileattr_set)(struct user_namespace *mnt_userns,
@@ -2783,6 +2784,15 @@ extern int finish_open(struct file *file, struct dentry *dentry,
 			int (*open)(struct inode *, struct file *));
 extern int finish_no_open(struct file *file, struct dentry *dentry);
 
+/* Helper for the simple case when original dentry is used */
+static inline int finish_open_simple(struct file *file, int error)
+{
+	if (error)
+		return error;
+
+	return finish_open(file, file->f_path.dentry, NULL);
+}
+
 /* fs/dcache.c */
 extern void __init vfs_caches_init_early(void);
 extern void __init vfs_caches_init(void);

include/uapi/linux/fuse.h

@@ -194,6 +194,9 @@
  *  - add FUSE_SECURITY_CTX init flag
  *  - add security context to create, mkdir, symlink, and mknod requests
  *  - add FUSE_HAS_INODE_DAX, FUSE_ATTR_DAX
+ *
+ *  7.37
+ *  - add FUSE_TMPFILE
  */
 
 #ifndef _LINUX_FUSE_H
@@ -229,7 +232,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 36
+#define FUSE_KERNEL_MINOR_VERSION 37
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -537,6 +540,7 @@ enum fuse_opcode {
 	FUSE_SETUPMAPPING	= 48,
 	FUSE_REMOVEMAPPING	= 49,
 	FUSE_SYNCFS		= 50,
+	FUSE_TMPFILE		= 51,
 
 	/* CUSE specific operations */
 	CUSE_INIT		= 4096,

mm/shmem.c

@@ -2916,7 +2916,7 @@ shmem_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 
 static int
 shmem_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
-	      struct dentry *dentry, umode_t mode)
+	      struct file *file, umode_t mode)
 {
 	struct inode *inode;
 	int error = -ENOSPC;
@@ -2931,9 +2931,9 @@ shmem_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 		error = simple_acl_create(dir, inode);
 		if (error)
 			goto out_iput;
-		d_tmpfile(dentry, inode);
+		d_tmpfile(file, inode);
 	}
-	return error;
+	return finish_open_simple(file, error);
 out_iput:
 	iput(inode);
 	return error;