diff options
| -rw-r--r-- | fs/kernfs/file.c | 47 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 2 |
2 files changed, 21 insertions, 28 deletions
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 22e7481e7b63..7d9138d2be3b 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -38,18 +38,16 @@ struct kernfs_open_node { struct list_head files; /* goes through kernfs_open_file.list */ }; -/* - * kernfs_notify() may be called from any context and bounces notifications - * through a work item. To minimize space overhead in kernfs_node, the - * pending queue is implemented as a singly linked list of kernfs_nodes. - * The list is terminated with the self pointer so that whether a - * kernfs_node is on the list or not can be determined by testing the next - * pointer for NULL. +/** + * attribute_to_node - get kernfs_node object corresponding to a kernfs attribute + * @ptr: &struct kernfs_elem_attr + * @type: struct kernfs_node + * @member: name of member (i.e attr) */ -#define KERNFS_NOTIFY_EOL ((void *)&kernfs_notify_list) +#define attribute_to_node(ptr, type, member) \ + container_of(ptr, type, member) -static DEFINE_SPINLOCK(kernfs_notify_lock); -static struct kernfs_node *kernfs_notify_list = KERNFS_NOTIFY_EOL; +static LLIST_HEAD(kernfs_notify_list); /** * kernfs_deref_open_node - Get kernfs_open_node corresponding to @kn. @@ -902,18 +900,16 @@ static void kernfs_notify_workfn(struct work_struct *work) struct kernfs_node *kn; struct kernfs_super_info *info; struct kernfs_root *root; + struct llist_node *free; + struct kernfs_elem_attr *attr; repeat: /* pop one off the notify_list */ - spin_lock_irq(&kernfs_notify_lock); - kn = kernfs_notify_list; - if (kn == KERNFS_NOTIFY_EOL) { - spin_unlock_irq(&kernfs_notify_lock); + free = llist_del_first(&kernfs_notify_list); + if (free == NULL) return; - } - kernfs_notify_list = kn->attr.notify_next; - kn->attr.notify_next = NULL; - spin_unlock_irq(&kernfs_notify_lock); + attr = llist_entry(free, struct kernfs_elem_attr, notify_next); + kn = attribute_to_node(attr, struct kernfs_node, attr); root = kernfs_root(kn); /* kick fsnotify */ down_write(&root->kernfs_rwsem); @@ -969,12 +965,14 @@ repeat: void kernfs_notify(struct kernfs_node *kn) { static DECLARE_WORK(kernfs_notify_work, kernfs_notify_workfn); - unsigned long flags; struct kernfs_open_node *on; if (WARN_ON(kernfs_type(kn) != KERNFS_FILE)) return; + /* Because we are using llist for kernfs_notify_list */ + WARN_ON_ONCE(in_nmi()); + /* kick poll immediately */ rcu_read_lock(); on = rcu_dereference(kn->attr.open); @@ -985,14 +983,9 @@ void kernfs_notify(struct kernfs_node *kn) rcu_read_unlock(); /* schedule work to kick fsnotify */ - spin_lock_irqsave(&kernfs_notify_lock, flags); - if (!kn->attr.notify_next) { - kernfs_get(kn); - kn->attr.notify_next = kernfs_notify_list; - kernfs_notify_list = kn; - schedule_work(&kernfs_notify_work); - } - spin_unlock_irqrestore(&kernfs_notify_lock, flags); + kernfs_get(kn); + llist_add(&kn->attr.notify_next, &kernfs_notify_list); + schedule_work(&kernfs_notify_work); } EXPORT_SYMBOL_GPL(kernfs_notify); diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 13f54f078a52..2dd9c8df0f4f 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -116,7 +116,7 @@ struct kernfs_elem_attr { const struct kernfs_ops *ops; struct kernfs_open_node __rcu *open; loff_t size; - struct kernfs_node *notify_next; /* for kernfs_notify() */ + struct llist_node notify_next; /* for kernfs_notify() */ }; /* |