fs: dcache scale dentry refcount

[mirror_ubuntu-zesty-kernel.git] / include / linux / dcache.h

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 2feb624b67f1ded9ca25cb2ca41d9ec53a292ec5..b0ade2d4680577580a36cf73312af97463f02b06 100644 (file)
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -87,7 +87,7 @@ full_name_hash(const unsigned char *name, unsigned int len)
 #endif
 
 struct dentry {
-       atomic_t d_count;
+       unsigned int d_count;           /* protected by d_lock */
        unsigned int d_flags;           /* protected by d_lock */
        spinlock_t d_lock;              /* per dentry lock */
        int d_mounted;
@@ -297,17 +297,28 @@ extern char *dentry_path(struct dentry *, char *, int);
  *     needs and they take necessary precautions) you should hold dcache_lock
  *     and call dget_locked() instead of dget().
  */
- 
+static inline struct dentry *dget_dlock(struct dentry *dentry)
+{
+       if (dentry) {
+               BUG_ON(!dentry->d_count);
+               dentry->d_count++;
+       }
+       return dentry;
+}
 static inline struct dentry *dget(struct dentry *dentry)
 {
        if (dentry) {
-               BUG_ON(!atomic_read(&dentry->d_count));
-               atomic_inc(&dentry->d_count);
+               spin_lock(&dentry->d_lock);
+               dget_dlock(dentry);
+               spin_unlock(&dentry->d_lock);
        }
        return dentry;
 }
 
 extern struct dentry * dget_locked(struct dentry *);
+extern struct dentry * dget_locked_dlock(struct dentry *);
+
+extern struct dentry *dget_parent(struct dentry *dentry);
 
 /**
  *     d_unhashed -    is dentry hashed
@@ -338,16 +349,6 @@ static inline void dont_mount(struct dentry *dentry)
        spin_unlock(&dentry->d_lock);
 }
 
-static inline struct dentry *dget_parent(struct dentry *dentry)
-{
-       struct dentry *ret;
-
-       spin_lock(&dentry->d_lock);
-       ret = dget(dentry->d_parent);
-       spin_unlock(&dentry->d_lock);
-       return ret;
-}
-
 extern void dput(struct dentry *);
 
 static inline int d_mountpoint(struct dentry *dentry)