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-rw-r--r--fs/notify/fanotify/fanotify.c40
-rw-r--r--fs/notify/fanotify/fanotify.h7
-rw-r--r--fs/notify/fanotify/fanotify_user.c7
-rw-r--r--fs/notify/inotify/inotify_fsnotify.c19
-rw-r--r--fs/notify/notification.c24
5 files changed, 52 insertions, 45 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 58772623f02a..0e792f5e3147 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -16,12 +16,6 @@ static bool should_merge(struct fsnotify_event *old_fsn,
{
struct fanotify_event_info *old, *new;
-#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- /* dont merge two permission events */
- if ((old_fsn->mask & FAN_ALL_PERM_EVENTS) &&
- (new_fsn->mask & FAN_ALL_PERM_EVENTS))
- return false;
-#endif
pr_debug("%s: old=%p new=%p\n", __func__, old_fsn, new_fsn);
old = FANOTIFY_E(old_fsn);
new = FANOTIFY_E(new_fsn);
@@ -34,14 +28,23 @@ static bool should_merge(struct fsnotify_event *old_fsn,
}
/* and the list better be locked by something too! */
-static struct fsnotify_event *fanotify_merge(struct list_head *list,
- struct fsnotify_event *event)
+static int fanotify_merge(struct list_head *list, struct fsnotify_event *event)
{
struct fsnotify_event *test_event;
bool do_merge = false;
pr_debug("%s: list=%p event=%p\n", __func__, list, event);
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ /*
+ * Don't merge a permission event with any other event so that we know
+ * the event structure we have created in fanotify_handle_event() is the
+ * one we should check for permission response.
+ */
+ if (event->mask & FAN_ALL_PERM_EVENTS)
+ return 0;
+#endif
+
list_for_each_entry_reverse(test_event, list, list) {
if (should_merge(test_event, event)) {
do_merge = true;
@@ -50,10 +53,10 @@ static struct fsnotify_event *fanotify_merge(struct list_head *list,
}
if (!do_merge)
- return NULL;
+ return 0;
test_event->mask |= event->mask;
- return test_event;
+ return 1;
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
@@ -149,7 +152,6 @@ static int fanotify_handle_event(struct fsnotify_group *group,
int ret = 0;
struct fanotify_event_info *event;
struct fsnotify_event *fsn_event;
- struct fsnotify_event *notify_fsn_event;
BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
@@ -188,21 +190,19 @@ static int fanotify_handle_event(struct fsnotify_group *group,
event->response = 0;
#endif
- notify_fsn_event = fsnotify_add_notify_event(group, fsn_event,
- fanotify_merge);
- if (notify_fsn_event) {
+ ret = fsnotify_add_notify_event(group, fsn_event, fanotify_merge);
+ if (ret) {
+ BUG_ON(mask & FAN_ALL_PERM_EVENTS);
/* Our event wasn't used in the end. Free it. */
fsnotify_destroy_event(group, fsn_event);
- if (IS_ERR(notify_fsn_event))
- return PTR_ERR(notify_fsn_event);
- /* We need to ask about a different events after a merge... */
- event = FANOTIFY_E(notify_fsn_event);
- fsn_event = notify_fsn_event;
+ ret = 0;
}
#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
- if (fsn_event->mask & FAN_ALL_PERM_EVENTS)
+ if (mask & FAN_ALL_PERM_EVENTS) {
ret = fanotify_get_response_from_access(group, event);
+ fsnotify_destroy_event(group, fsn_event);
+ }
#endif
return ret;
}
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 0e90174a116a..32a2f034fb94 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -4,6 +4,13 @@
extern struct kmem_cache *fanotify_event_cachep;
+/*
+ * Lifetime of the structure differs for normal and permission events. In both
+ * cases the structure is allocated in fanotify_handle_event(). For normal
+ * events the structure is freed immediately after reporting it to userspace.
+ * For permission events we free it only after we receive response from
+ * userspace.
+ */
struct fanotify_event_info {
struct fsnotify_event fse;
/*
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 1fd66abe5740..b6175fa11bf8 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -319,7 +319,12 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
if (IS_ERR(kevent))
break;
ret = copy_event_to_user(group, kevent, buf);
- fsnotify_destroy_event(group, kevent);
+ /*
+ * Permission events get destroyed after we
+ * receive response
+ */
+ if (!(kevent->mask & FAN_ALL_PERM_EVENTS))
+ fsnotify_destroy_event(group, kevent);
if (ret < 0)
break;
buf += ret;
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index aad1a35e9af1..d5ee56348bb8 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -53,15 +53,13 @@ static bool event_compare(struct fsnotify_event *old_fsn,
return false;
}
-static struct fsnotify_event *inotify_merge(struct list_head *list,
- struct fsnotify_event *event)
+static int inotify_merge(struct list_head *list,
+ struct fsnotify_event *event)
{
struct fsnotify_event *last_event;
last_event = list_entry(list->prev, struct fsnotify_event, list);
- if (!event_compare(last_event, event))
- return NULL;
- return last_event;
+ return event_compare(last_event, event);
}
int inotify_handle_event(struct fsnotify_group *group,
@@ -73,9 +71,8 @@ int inotify_handle_event(struct fsnotify_group *group,
{
struct inotify_inode_mark *i_mark;
struct inotify_event_info *event;
- struct fsnotify_event *added_event;
struct fsnotify_event *fsn_event;
- int ret = 0;
+ int ret;
int len = 0;
int alloc_len = sizeof(struct inotify_event_info);
@@ -110,18 +107,16 @@ int inotify_handle_event(struct fsnotify_group *group,
if (len)
strcpy(event->name, file_name);
- added_event = fsnotify_add_notify_event(group, fsn_event, inotify_merge);
- if (added_event) {
+ ret = fsnotify_add_notify_event(group, fsn_event, inotify_merge);
+ if (ret) {
/* Our event wasn't used in the end. Free it. */
fsnotify_destroy_event(group, fsn_event);
- if (IS_ERR(added_event))
- ret = PTR_ERR(added_event);
}
if (inode_mark->mask & IN_ONESHOT)
fsnotify_destroy_mark(inode_mark, group);
- return ret;
+ return 0;
}
static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group)
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 952237b8e2d2..18b3c4427dca 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -79,15 +79,15 @@ void fsnotify_destroy_event(struct fsnotify_group *group,
/*
* Add an event to the group notification queue. The group can later pull this
- * 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.
+ * event off the queue to deal with. The function returns 0 if the event was
+ * added to the queue, 1 if the event was merged with some other queued event.
*/
-struct fsnotify_event *fsnotify_add_notify_event(struct fsnotify_group *group,
- struct fsnotify_event *event,
- struct fsnotify_event *(*merge)(struct list_head *,
- struct fsnotify_event *))
+int fsnotify_add_notify_event(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ int (*merge)(struct list_head *,
+ struct fsnotify_event *))
{
- struct fsnotify_event *return_event = NULL;
+ int ret = 0;
struct list_head *list = &group->notification_list;
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
@@ -98,14 +98,14 @@ struct fsnotify_event *fsnotify_add_notify_event(struct fsnotify_group *group,
/* Queue overflow event only if it isn't already queued */
if (list_empty(&group->overflow_event.list))
event = &group->overflow_event;
- return_event = event;
+ ret = 1;
}
if (!list_empty(list) && merge) {
- return_event = merge(list, event);
- if (return_event) {
+ ret = merge(list, event);
+ if (ret) {
mutex_unlock(&group->notification_mutex);
- return return_event;
+ return ret;
}
}
@@ -115,7 +115,7 @@ struct fsnotify_event *fsnotify_add_notify_event(struct fsnotify_group *group,
wake_up(&group->notification_waitq);
kill_fasync(&group->fsn_fa, SIGIO, POLL_IN);
- return return_event;
+ return ret;
}
/*
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-15 18:02:48 +0300