diff options
| -rw-r--r-- | fs/notify/fsnotify.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index dd3fb0b17be7..d675e76251d3 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -205,6 +205,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, mnt = NULL; /* + * Optimization: srcu_read_lock() has a memory barrier which can + * be expensive. It protects walking the *_fsnotify_marks lists. + * However, if we do not walk the lists, we do not have to do + * SRCU because we have no references to any objects and do not + * need SRCU to keep them "alive". + */ + if (hlist_empty(&to_tell->i_fsnotify_marks) && + (!mnt || hlist_empty(&mnt->mnt_fsnotify_marks))) + return 0; + /* * if this is a modify event we may need to clear the ignored masks * otherwise return if neither the inode nor the vfsmount care about * this type of event. |