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fanotify: Move locking inside get_one_event()

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get_one_event() has a single caller and that just locks
notification_lock around the call. Move locking inside get_one_event()
as that will make using ->response field for permission event state
easier.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2019-01-08 13:52:31 +01:00
parent af6a511306
commit 8c5544666c
1 changed files with 13 additions and 19 deletions
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32
fs/notify/fanotify/fanotify_user.c
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@ -65,35 +65,32 @@ static int fanotify_event_info_len(struct fanotify_event *event)
* Get an fsnotify notification event if one exists and is small
* enough to fit in "count". Return an error pointer if the count
* is not large enough.
*
* Called with the group->notification_lock held.
*/
static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
size_t count)
{
size_t event_size = FAN_EVENT_METADATA_LEN;
struct fanotify_event *event;
assert_spin_locked(&group->notification_lock);
struct fsnotify_event *fsn_event = NULL;
pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
spin_lock(&group->notification_lock);
if (fsnotify_notify_queue_is_empty(group))
return NULL;
goto out;
if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
event = FANOTIFY_E(fsnotify_peek_first_event(group));
event_size += fanotify_event_info_len(event);
event_size += fanotify_event_info_len(
FANOTIFY_E(fsnotify_peek_first_event(group)));
}
if (event_size > count)
return ERR_PTR(-EINVAL);
/*
* Held the notification_lock the whole time, so this is the
* same event we peeked above
*/
return fsnotify_remove_first_event(group);
if (event_size > count) {
fsn_event = ERR_PTR(-EINVAL);
goto out;
}
fsn_event = fsnotify_remove_first_event(group);
out:
spin_unlock(&group->notification_lock);
return fsn_event;
}
static int create_fd(struct fsnotify_group *group,
@ -316,10 +313,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
add_wait_queue(&group->notification_waitq, &wait);
while (1) {
spin_lock(&group->notification_lock);
kevent = get_one_event(group, count);
spin_unlock(&group->notification_lock);
if (IS_ERR(kevent)) {
ret = PTR_ERR(kevent);
break;