diff options
| -rw-r--r-- | fs/notify/dnotify/dnotify.c | 1 | ||||
| -rw-r--r-- | fs/notify/notification.c | 52 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 24 |
3 files changed, 68 insertions, 9 deletions
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index d9d80f5..12f9e6b 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -183,6 +183,7 @@ static struct fsnotify_ops dnotify_fsnotify_ops = { .should_send_event = dnotify_should_send_event, .free_group_priv = NULL, .freeing_mark = dnotify_freeing_mark, + .free_event_priv = NULL, }; /* diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 346f6e5..959b73e 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -90,6 +90,8 @@ void fsnotify_put_event(struct fsnotify_event *event) if (event->data_type == FSNOTIFY_EVENT_PATH) path_put(&event->path); + BUG_ON(!list_empty(&event->private_data_list)); + kfree(event->file_name); kmem_cache_free(fsnotify_event_cachep, event); } @@ -106,7 +108,29 @@ void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder) } /* - * check if 2 events contain the same information. + * Find the private data that the group previously attached to this event when + * the group added the event to the notification queue (fsnotify_add_notify_event) + */ +struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group, struct fsnotify_event *event) +{ + struct fsnotify_event_private_data *lpriv; + struct fsnotify_event_private_data *priv = NULL; + + assert_spin_locked(&event->lock); + + list_for_each_entry(lpriv, &event->private_data_list, event_list) { + if (lpriv->group == group) { + priv = lpriv; + list_del(&priv->event_list); + break; + } + } + return priv; +} + +/* + * Check if 2 events contain the same information. We do not compare private data + * but at this moment that isn't a problem for any know fsnotify listeners. */ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new) { @@ -134,13 +158,17 @@ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new * event off the queue to deal with. If the event is successfully added to the * group's notification queue, a reference is taken on event. */ -int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event) +int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, + struct fsnotify_event_private_data *priv) { struct fsnotify_event_holder *holder = NULL; struct list_head *list = &group->notification_list; struct fsnotify_event_holder *last_holder; struct fsnotify_event *last_event; + /* easy to tell if priv was attached to the event */ + INIT_LIST_HEAD(&priv->event_list); + /* * There is one fsnotify_event_holder embedded inside each fsnotify_event. * Check if we expect to be able to use that holder. If not alloc a new @@ -158,8 +186,11 @@ alloc_holder: mutex_lock(&group->notification_mutex); - if (group->q_len >= group->max_events) + if (group->q_len >= group->max_events) { event = &q_overflow_event; + /* sorry, no private data on the overflow event */ + priv = NULL; + } spin_lock(&event->lock); @@ -183,7 +214,7 @@ alloc_holder: mutex_unlock(&group->notification_mutex); if (holder != &event->holder) fsnotify_destroy_event_holder(holder); - return 0; + return -EEXIST; } } @@ -192,6 +223,8 @@ alloc_holder: fsnotify_get_event(event); list_add_tail(&holder->event_list, list); + if (priv) + list_add_tail(&priv->event_list, &event->private_data_list); spin_unlock(&event->lock); mutex_unlock(&group->notification_mutex); @@ -252,10 +285,19 @@ struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group) void fsnotify_flush_notify(struct fsnotify_group *group) { struct fsnotify_event *event; + struct fsnotify_event_private_data *priv; mutex_lock(&group->notification_mutex); while (!fsnotify_notify_queue_is_empty(group)) { event = fsnotify_remove_notify_event(group); + /* if they don't implement free_event_priv they better not have attached any */ + if (group->ops->free_event_priv) { + spin_lock(&event->lock); + priv = fsnotify_remove_priv_from_event(group, event); + spin_unlock(&event->lock); + if (priv) + group->ops->free_event_priv(priv); + } fsnotify_put_event(event); /* matches fsnotify_add_notify_event */ } mutex_unlock(&group->notification_mutex); @@ -274,6 +316,8 @@ static void initialize_event(struct fsnotify_event *event) event->inode = NULL; event->data_type = FSNOTIFY_EVENT_NONE; + INIT_LIST_HEAD(&event->private_data_list); + event->to_tell = NULL; event->file_name = NULL; diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index b78b557..efdf9e4 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -63,6 +63,7 @@ struct fsnotify_group; struct fsnotify_event; struct fsnotify_mark_entry; +struct fsnotify_event_private_data; /* * Each group much define these ops. The fsnotify infrastructure will call @@ -81,6 +82,7 @@ struct fsnotify_ops { int (*handle_event)(struct fsnotify_group *group, struct fsnotify_event *event); void (*free_group_priv)(struct fsnotify_group *group); void (*freeing_mark)(struct fsnotify_mark_entry *entry, struct fsnotify_group *group); + void (*free_event_priv)(struct fsnotify_event_private_data *priv); }; /* @@ -158,6 +160,15 @@ struct fsnotify_event_holder { }; /* + * Inotify needs to tack data onto an event. This struct lets us later find the + * correct private data of the correct group. + */ +struct fsnotify_event_private_data { + struct fsnotify_group *group; + struct list_head event_list; +}; + +/* * all of the information about the original object we want to now send to * a group. If you want to carry more info from the accessing task to the * listener this structure is where you need to be adding fields. @@ -196,6 +207,8 @@ struct fsnotify_event { u32 sync_cookie; /* used to corrolate events, namely inotify mv events */ char *file_name; size_t name_len; + + struct list_head private_data_list; /* groups can store private data here */ }; /* @@ -294,17 +307,18 @@ extern void fsnotify_put_group(struct fsnotify_group *group); /* take a reference to an event */ extern void fsnotify_get_event(struct fsnotify_event *event); extern void fsnotify_put_event(struct fsnotify_event *event); -/* find private data previously attached to an event */ -extern struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct fsnotify_group *group, - struct fsnotify_event *event); +/* find private data previously attached to an event and unlink it */ +extern struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group, + struct fsnotify_event *event); /* attach the event to the group notification queue */ -extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event); +extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, + struct fsnotify_event_private_data *priv); /* true if the group notification queue is empty */ extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); /* return, but do not dequeue the first event on the notification queue */ extern struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group); -/* reutnr AND dequeue the first event on the notification queue */ +/* return AND dequeue the first event on the notification queue */ extern struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group); /* functions used to manipulate the marks attached to inodes */ |
