Messages in this thread Patch in this message | | | From | Eric Paris <> | Subject | [PATCH 10/13] fsnotify: allow groups to add private data to events | Date | Thu, 19 Mar 2009 14:05:47 -0400 |
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inotify needs per group information attached to events. This patch allows groups to attach private information and implements a callback so that information can be freed when an event is being destroyed.
Signed-off-by: Eric Paris <eparis@redhat.com> ---
fs/notify/dnotify/dnotify.c | 1 + fs/notify/notification.c | 31 +++++++++++++++++++++++++++---- include/linux/fsnotify_backend.h | 15 ++++++++++++++- 3 files changed, 42 insertions(+), 5 deletions(-)
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index f69e0c4..26c07c5 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -152,6 +152,7 @@ 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, }; void dnotify_flush(struct file *filp, fl_owner_t id) diff --git a/fs/notify/notification.c b/fs/notify/notification.c index ecab682..d71fc9b 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -71,6 +71,7 @@ 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(event_kmem_cache, event); } @@ -86,8 +87,23 @@ void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder) kmem_cache_free(event_holder_kmem_cache, holder); } +struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct fsnotify_group *group, struct fsnotify_event *event) +{ + struct fsnotify_event_private_data *lpriv; + struct fsnotify_event_private_data *priv = NULL; + + list_for_each_entry(lpriv, &event->private_data_list, event_list) { + if (lpriv->group == group) { + priv = lpriv; + break; + } + } + return priv; +} + /* - * check if 2 events contain the same information. + * check if 2 events contain the same information. we do not compare private data + * but at this moment that isn't a problem. */ static inline int event_compare(struct fsnotify_event *old, struct fsnotify_event *new) { @@ -111,10 +127,11 @@ static inline int event_compare(struct fsnotify_event *old, struct fsnotify_even } /* - * Add an event to the group notification queue. The group can later pull this - * event off the queue to deal with. + * Add events to the generic group notification queue. We test if the event + * is the same as the last event in the queue, and if so, we do not add it. + * Events added to this queue must be removed with fsnotify_remove_notif_event. */ -int fsnotify_add_notif_event(struct fsnotify_group *group, struct fsnotify_event *event) +int fsnotify_add_notif_event(struct fsnotify_group *group, struct fsnotify_event *event, struct fsnotify_event_private_data *priv) { struct fsnotify_event_holder *holder; struct list_head *list = &group->notification_list; @@ -166,6 +183,8 @@ int fsnotify_add_notif_event(struct fsnotify_group *group, struct fsnotify_event 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); @@ -230,6 +249,8 @@ void fsnotify_flush_notif(struct fsnotify_group *group) mutex_lock(&group->notification_mutex); while (fsnotify_check_notif_queue(group)) { event = fsnotify_remove_notif_event(group); + if (group->ops->free_event_priv) + group->ops->free_event_priv(group, event); fsnotify_put_event(event); } mutex_unlock(&group->notification_mutex); @@ -248,6 +269,8 @@ 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 467ced7..b575dd0 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -79,6 +79,7 @@ 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_group *group, struct fsnotify_event *event); }; /* @@ -130,6 +131,15 @@ 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. @@ -163,6 +173,8 @@ 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 */ }; /* @@ -238,10 +250,11 @@ extern void fsnotify_put_group(struct fsnotify_group *group); extern void fsnotify_get_event(struct fsnotify_event *event); extern void fsnotify_put_event(struct fsnotify_event *event); -extern int fsnotify_add_notif_event(struct fsnotify_group *group, struct fsnotify_event *event); +extern int fsnotify_add_notif_event(struct fsnotify_group *group, struct fsnotify_event *event, struct fsnotify_event_private_data *priv); extern int fsnotify_check_notif_queue(struct fsnotify_group *group); extern struct fsnotify_event *fsnotify_peek_notif_event(struct fsnotify_group *group); extern struct fsnotify_event *fsnotify_remove_notif_event(struct fsnotify_group *group); +extern struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct fsnotify_group *group, struct fsnotify_event *event); /* functions used to manipulate the marks attached to inodes */ extern void fsnotify_recalc_inode_mask(struct inode *inode);
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