vfs/fsnotify: fsnotify_close can delay the final work in fput

[cascardo/linux.git] / fs / notify / notification.c

diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index c106cdd..d6c435a 100644 (file)
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -426,6 +426,19 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
        switch (data_type) {
        case FSNOTIFY_EVENT_FILE: {
                event->file = data;
+               /*
+                * if this file is about to disappear hold an extra reference
+                * until we return to __fput so we don't have to worry about
+                * future get/put destroying the file under us or generating
+                * additional events.  Notice that we change f_mode without
+                * holding f_lock.  This is safe since this is the only possible
+                * reference to this object in the kernel (it was about to be
+                * freed, remember?)
+                */
+               if (!atomic_long_read(&event->file->f_count)) {
+                       event->file->f_mode |= FMODE_NONOTIFY;
+                       get_file(event->file);
+               }
                get_file(event->file);
                break;
        }