dcache-split-inode_lock

dcache_inode_lock can be replaced with per-inode locking. Use existing
inode->i_lock for this. This is slightly non-trivial because we sometimes
need to find the inode from the dentry, which requires d_inode to be
stabilised (either with refcount or d_lock).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 3 insertions, 13 deletions

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index e3bec299113a..1ca2e7fb7a86 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -186,7 +186,6 @@ d_iput:		no		no       yes
 
 #define DCACHE_FSNOTIFY_PARENT_WATCHED  0x0080 /* Parent inode is watched by some fsnotify listener */
 
-extern spinlock_t dcache_inode_lock;
 extern seqlock_t rename_lock;
 
 /**
@@ -303,23 +302,17 @@ extern char *dentry_path(struct dentry *, char *, int);
 /* Allocation counts.. */
 
 /**
- *      dget, dget_locked       -       get a reference to a dentry
+ *      dget, dget_dlock -      get a reference to a dentry
  *      @dentry: dentry to get a reference to
  *
  *      Given a dentry or %NULL pointer increment the reference count
  *      if appropriate and return the dentry. A dentry will not be 
- *      destroyed when it has references. dget() should never be
- *      called for dentries with zero reference counter. For these cases
- *      (preferably none, functions in dcache.c are sufficient for normal
- *      needs and they take necessary precautions) you should hold dcache_lock
- *      and call dget_locked() instead of dget().
+ *      destroyed when it has references.
  */
 static inline struct dentry *dget_dlock(struct dentry *dentry)
 {
-        if (dentry) {
-                BUG_ON(!dentry->d_count);
+        if (dentry)
                 dentry->d_count++;
-        }
         return dentry;
 }
 
@@ -333,9 +326,6 @@ static inline struct dentry *dget(struct dentry *dentry)
         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);
 
 /**