fsnotify: allow groups to add private data to events

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>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Eric Paris
2009-05-21 17:01:50 -04:00
parent 47882c6f51
commit e4aff11736
3 changed files with 68 additions and 9 deletions

View File

@@ -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);
};
/*
@@ -157,6 +159,15 @@ struct fsnotify_event_holder {
struct list_head event_list;
};
/*
* 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
@@ -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 */