Commit e87f2c26 authored by Al Viro's avatar Al Viro
Browse files

struct file: use anonymous union member for rcuhead and llist 



Once upon a time we couldn't afford anon unions; these days minimal
gcc version had been raised enough to take care of that.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent eacdf4ea

fs/file_table.c

+8 −8
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ static struct percpu_counter nr_files __cacheline_aligned_in_smp; 


static void file_free_rcu(struct rcu_head *head)

{

	struct file *f = container_of(head, struct file, f_u.fu_rcuhead);

	struct file *f = container_of(head, struct file, f_rcuhead);



	put_cred(f->f_cred);

	kmem_cache_free(filp_cachep, f);
@@ -56,7 +56,7 @@ static inline void file_free(struct file *f) 
	security_file_free(f);

	if (!(f->f_mode & FMODE_NOACCOUNT))

		percpu_counter_dec(&nr_files);

	call_rcu(&f->f_u.fu_rcuhead, file_free_rcu);

	call_rcu(&f->f_rcuhead, file_free_rcu);

}



/*
@@ -142,7 +142,7 @@ static struct file *__alloc_file(int flags, const struct cred *cred) 
	f->f_cred = get_cred(cred);

	error = security_file_alloc(f);

	if (unlikely(error)) {

		file_free_rcu(&f->f_u.fu_rcuhead);

		file_free_rcu(&f->f_rcuhead);

		return ERR_PTR(error);

	}
@@ -341,13 +341,13 @@ static void delayed_fput(struct work_struct *unused) 
	struct llist_node *node = llist_del_all(&delayed_fput_list);

	struct file *f, *t;



	llist_for_each_entry_safe(f, t, node, f_u.fu_llist)

	llist_for_each_entry_safe(f, t, node, f_llist)

		__fput(f);

}



static void ____fput(struct callback_head *work)

{

	__fput(container_of(work, struct file, f_u.fu_rcuhead));

	__fput(container_of(work, struct file, f_rcuhead));

}



/*
@@ -374,8 +374,8 @@ void fput(struct file *file) 
		struct task_struct *task = current;



		if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) {

			init_task_work(&file->f_u.fu_rcuhead, ____fput);

			if (!task_work_add(task, &file->f_u.fu_rcuhead, TWA_RESUME))

			init_task_work(&file->f_rcuhead, ____fput);

			if (!task_work_add(task, &file->f_rcuhead, TWA_RESUME))

				return;

			/*

			 * After this task has run exit_task_work(),
@@ -384,7 +384,7 @@ void fput(struct file *file) 
			 */

		}



		if (llist_add(&file->f_u.fu_llist, &delayed_fput_list))

		if (llist_add(&file->f_llist, &delayed_fput_list))

			schedule_delayed_work(&delayed_fput_work, 1);

	}

}

include/linux/fs.h

+3 −3
Original line number Diff line number Diff line
@@ -924,9 +924,9 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) 


struct file {

	union {

		struct llist_node	fu_llist;

		struct rcu_head 	fu_rcuhead;

	} f_u;

		struct llist_node	f_llist;

		struct rcu_head 	f_rcuhead;

	};

	struct path		f_path;

	struct inode		*f_inode;	/* cached value */

	const struct file_operations	*f_op;