untangle fsnotify_d_instantiate() a bit

First of all, don't bother calling it if inode is NULL -
that makes inode argument unused.  Moreover, do it *before*
dropping ->d_lock, not right after that (and don't bother
grabbing ->d_lock in it, of course).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/dcache.c

@@ -1750,8 +1750,9 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 	raw_write_seqcount_begin(&dentry->d_seq);
 	__d_set_inode_and_type(dentry, inode, add_flags);
 	raw_write_seqcount_end(&dentry->d_seq);
+	if (inode)
+		__fsnotify_d_instantiate(dentry);
 	spin_unlock(&dentry->d_lock);
-	fsnotify_d_instantiate(dentry, inode);
 }
 
 /**

include/linux/fsnotify.h

@@ -16,15 +16,6 @@
 #include <linux/slab.h>
 #include <linux/bug.h>
 
-/*
- * fsnotify_d_instantiate - instantiate a dentry for inode
- */
-static inline void fsnotify_d_instantiate(struct dentry *dentry,
-					  struct inode *inode)
-{
-	__fsnotify_d_instantiate(dentry, inode);
-}
-
 /* Notify this dentry's parent about a child's events. */
 static inline int fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
 {

include/linux/fsnotify_backend.h

@@ -293,14 +293,9 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 /*
  * fsnotify_d_instantiate - instantiate a dentry for inode
  */
-static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
+static inline void __fsnotify_d_instantiate(struct dentry *dentry)
 {
-	if (!inode)
-		return;
-
-	spin_lock(&dentry->d_lock);
 	__fsnotify_update_dcache_flags(dentry);
-	spin_unlock(&dentry->d_lock);
 }
 
 /* called from fsnotify listeners, such as fanotify or dnotify */
@@ -399,7 +394,7 @@ static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
 static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 {}
 
-static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
+static inline void __fsnotify_d_instantiate(struct dentry *dentry)
 {}
 
 static inline u32 fsnotify_get_cookie(void)