From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760652AbZD0V5Z (ORCPT ); Mon, 27 Apr 2009 17:57:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757239AbZD0VzE (ORCPT ); Mon, 27 Apr 2009 17:55:04 -0400 Received: from mx2.redhat.com ([66.187.237.31]:41450 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756990AbZD0Vy7 (ORCPT ); Mon, 27 Apr 2009 17:54:59 -0400 From: Eric Paris Subject: [PATCH 09/12] fsnotify: allow groups to add private data to events To: linux-kernel@vger.kernel.org Cc: viro@zeniv.linux.org.uk, hch@infradead.org, alan@lxorguk.ukuu.org.uk, sfr@canb.auug.org.au, john@johnmccutchan.com, rlove@rlove.org, akpm@linux-foundation.org Date: Mon, 27 Apr 2009 17:53:50 -0400 Message-ID: <20090427215349.14161.52570.stgit@paris.rdu.redhat.com> In-Reply-To: <20090427215305.14161.33354.stgit@paris.rdu.redhat.com> References: <20090427215305.14161.33354.stgit@paris.rdu.redhat.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- fs/notify/dnotify/dnotify.c | 1 + fs/notify/notification.c | 37 ++++++++++++++++++++++++++++++++++--- include/linux/fsnotify_backend.h | 17 ++++++++++++++++- 3 files changed, 51 insertions(+), 4 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..3e6e364 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 +108,26 @@ 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_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. 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 +155,17 @@ 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 @@ -183,7 +208,7 @@ alloc_holder: mutex_unlock(&group->notification_mutex); if (holder != &event->holder) fsnotify_destroy_event_holder(holder); - return 0; + return -EEXIST; } } @@ -192,6 +217,8 @@ 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); @@ -256,6 +283,8 @@ void fsnotify_flush_notify(struct fsnotify_group *group) mutex_lock(&group->notification_mutex); while (!fsnotify_notify_queue_is_empty(group)) { event = fsnotify_remove_notify_event(group); + if (group->ops->free_event_priv) + group->ops->free_event_priv(group, event); fsnotify_put_event(event); /* matches fsnotify_add_notify_event */ } mutex_unlock(&group->notification_mutex); @@ -274,6 +303,8 @@ 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..de5c793 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -81,6 +81,7 @@ 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); }; /* @@ -158,6 +159,15 @@ 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 +206,8 @@ 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 */ }; /* @@ -299,13 +311,16 @@ extern struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct f 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 */ extern struct fsnotify_event *fsnotify_remove_notify_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 */