fs: dcache remove dcache_lock

dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

1 files changed, 7 insertions, 4 deletions

diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 7380763595d3..69ad89b50489 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -329,9 +329,15 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 {
         struct dentry *parent;
 
-        assert_spin_locked(&dcache_lock);
         assert_spin_locked(&dentry->d_lock);
 
+        /*
+         * Serialisation of setting PARENT_WATCHED on the dentries is provided
+         * by d_lock. If inotify_inode_watched changes after we have taken
+         * d_lock, the following __fsnotify_update_child_dentry_flags call will
+         * find our entry, so it will spin until we complete here, and update
+         * us with the new state.
+         */
         parent = dentry->d_parent;
         if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode))
                 dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
@@ -341,15 +347,12 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 
 /*
  * fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
  */
 static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
 {
         if (!inode)
                 return;
 
-        assert_spin_locked(&dcache_lock);
-
         spin_lock(&dentry->d_lock);
         __fsnotify_update_dcache_flags(dentry);
         spin_unlock(&dentry->d_lock);