Current code has an assumtion that fsnotify_notify_queue_is_empty() is
called to verify that queue is not empty before trying to peek or remove
an event from queue.
Remove this assumption by moving the fsnotify_notify_queue_is_empty()
into the functions, allow them to return NULL value and check return
value by all callers.
This is a prep patch for multi event queues.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/notify/fanotify/fanotify_user.c | 26 ++++++++++++++++----------
fs/notify/inotify/inotify_user.c | 5 ++---
fs/notify/notification.c | 6 ++++++
3 files changed, 24 insertions(+), 13 deletions(-)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index b78dd1f88f7c..8ff27d92d32c 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -100,24 +100,30 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group,
{
size_t event_size = FAN_EVENT_METADATA_LEN;
struct fanotify_event *event = NULL;
+ struct fsnotify_event *fsn_event;
unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
spin_lock(&group->notification_lock);
- if (fsnotify_notify_queue_is_empty(group))
+ fsn_event = fsnotify_peek_first_event(group);
+ if (!fsn_event)
goto out;
- if (fid_mode) {
- event_size += fanotify_event_info_len(fid_mode,
- FANOTIFY_E(fsnotify_peek_first_event(group)));
- }
+ event = FANOTIFY_E(fsn_event);
+ if (fid_mode)
+ event_size += fanotify_event_info_len(fid_mode, event);
if (event_size > count) {
event = ERR_PTR(-EINVAL);
goto out;
}
- event = FANOTIFY_E(fsnotify_remove_first_event(group));
+
+ /*
+ * Held the notification_lock the whole time, so this is the
+ * same event we peeked above.
+ */
+ fsnotify_remove_first_event(group);
if (fanotify_is_perm_event(event->mask))
FANOTIFY_PERM(event)->state = FAN_EVENT_REPORTED;
out:
@@ -573,6 +579,7 @@ static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t
static int fanotify_release(struct inode *ignored, struct file *file)
{
struct fsnotify_group *group = file->private_data;
+ struct fsnotify_event *fsn_event;
/*
* Stop new events from arriving in the notification queue. since
@@ -601,13 +608,12 @@ static int fanotify_release(struct inode *ignored, struct file *file)
* dequeue them and set the response. They will be freed once the
* response is consumed and fanotify_get_response() returns.
*/
- while (!fsnotify_notify_queue_is_empty(group)) {
- struct fanotify_event *event;
+ while ((fsn_event = fsnotify_remove_first_event(group))) {
+ struct fanotify_event *event = FANOTIFY_E(fsn_event);
- event = FANOTIFY_E(fsnotify_remove_first_event(group));
if (!(event->mask & FANOTIFY_PERM_EVENTS)) {
spin_unlock(&group->notification_lock);
- fsnotify_destroy_event(group, &event->fse);
+ fsnotify_destroy_event(group, fsn_event);
} else {
finish_permission_event(group, FANOTIFY_PERM(event),
FAN_ALLOW);
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 266d17e8ecb9..d8830be60a9b 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -146,10 +146,9 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
size_t event_size = sizeof(struct inotify_event);
struct fsnotify_event *event;
- if (fsnotify_notify_queue_is_empty(group))
- return NULL;
-
event = fsnotify_peek_first_event(group);
+ if (!event)
+ return NULL;
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 75d79d6d3ef0..fcac2d72cbf5 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -150,6 +150,9 @@ struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group)
assert_spin_locked(&group->notification_lock);
+ if (fsnotify_notify_queue_is_empty(group))
+ return NULL;
+
pr_debug("%s: group=%p\n", __func__, group);
event = list_first_entry(&group->notification_list,
@@ -166,6 +169,9 @@ struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group)
{
assert_spin_locked(&group->notification_lock);
+ if (fsnotify_notify_queue_is_empty(group))
+ return NULL;
+
return list_first_entry(&group->notification_list,
struct fsnotify_event, list);
}
--
2.25.1
