From f70ab54cc6c3907b0727ba332b3976f80f3846d0 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 28 Jul 2010 10:18:37 -0400 Subject: fsnotify: fsnotify_add_notify_event should return an event Rather than the horrific void ** argument and such just to pass the fanotify_merge event back to the caller of fsnotify_add_notify_event() have those things return an event if it was different than the event suggusted to be added. Signed-off-by: Eric Paris --- fs/notify/fanotify/fanotify.c | 103 +++++++++++++++++++----------------------- 1 file changed, 46 insertions(+), 57 deletions(-) (limited to 'fs/notify/fanotify') diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index bbcfccd4a8ea..f3c40c0e2b86 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -30,65 +30,58 @@ static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new) return false; } -/* Note, if we return an event in *arg that a reference is being held... */ -static int fanotify_merge(struct list_head *list, - struct fsnotify_event *event, - void **arg) +/* and the list better be locked by something too! */ +static struct fsnotify_event *fanotify_merge(struct list_head *list, + struct fsnotify_event *event) { struct fsnotify_event_holder *test_holder; - struct fsnotify_event *test_event; + struct fsnotify_event *test_event = NULL; struct fsnotify_event *new_event; - struct fsnotify_event **return_event = (struct fsnotify_event **)arg; - int ret = 0; pr_debug("%s: list=%p event=%p\n", __func__, list, event); - *return_event = NULL; - - /* and the list better be locked by something too! */ list_for_each_entry_reverse(test_holder, list, event_list) { - test_event = test_holder->event; - if (should_merge(test_event, event)) { - fsnotify_get_event(test_event); - *return_event = test_event; - - ret = -EEXIST; - /* if they are exactly the same we are done */ - if (test_event->mask == event->mask) - goto out; - - /* - * if the refcnt == 1 this is the only queue - * for this event and so we can update the mask - * in place. - */ - if (atomic_read(&test_event->refcnt) == 1) { - test_event->mask |= event->mask; - goto out; - } - - /* can't allocate memory, merge was no possible */ - new_event = fsnotify_clone_event(test_event); - if (unlikely(!new_event)) { - ret = 0; - goto out; - } - - /* we didn't return the test_event, so drop that ref */ - fsnotify_put_event(test_event); - /* the reference we return on new_event is from clone */ - *return_event = new_event; - - /* build new event and replace it on the list */ - new_event->mask = (test_event->mask | event->mask); - fsnotify_replace_event(test_holder, new_event); - + if (should_merge(test_holder->event, event)) { + test_event = test_holder->event; break; } } -out: - return ret; + + if (!test_event) + return NULL; + + fsnotify_get_event(test_event); + + /* if they are exactly the same we are done */ + if (test_event->mask == event->mask) + return test_event; + + /* + * if the refcnt == 2 this is the only queue + * for this event and so we can update the mask + * in place. + */ + if (atomic_read(&test_event->refcnt) == 2) { + test_event->mask |= event->mask; + return test_event; + } + + new_event = fsnotify_clone_event(test_event); + + /* done with test_event */ + fsnotify_put_event(test_event); + + /* couldn't allocate memory, merge was not possible */ + if (unlikely(!new_event)) + return ERR_PTR(-ENOMEM); + + /* build new event and replace it on the list */ + new_event->mask = (test_event->mask | event->mask); + fsnotify_replace_event(test_holder, new_event); + + /* we hold a reference on new_event from clone_event */ + return new_event; } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS @@ -123,7 +116,7 @@ static int fanotify_get_response_from_access(struct fsnotify_group *group, static int fanotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event) { - int ret; + int ret = 0; struct fsnotify_event *notify_event = NULL; BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); @@ -138,13 +131,9 @@ static int fanotify_handle_event(struct fsnotify_group *group, struct fsnotify_e pr_debug("%s: group=%p event=%p\n", __func__, group, event); - ret = fsnotify_add_notify_event(group, event, NULL, fanotify_merge, - (void **)¬ify_event); - /* -EEXIST means this event was merged with another, not that it was an error */ - if (ret == -EEXIST) - ret = 0; - if (ret) - goto out; + notify_event = fsnotify_add_notify_event(group, event, NULL, fanotify_merge); + if (IS_ERR(notify_event)) + return PTR_ERR(notify_event); #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (event->mask & FAN_ALL_PERM_EVENTS) { @@ -155,9 +144,9 @@ static int fanotify_handle_event(struct fsnotify_group *group, struct fsnotify_e } #endif -out: if (notify_event) fsnotify_put_event(notify_event); + return ret; } -- cgit v1.2.1