9p: don't bother with private lock in ->d_fsdata; dentry->d_lock will do just fine

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 6 insertions, 7 deletions

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index afd4724b2d92..71bc36a03e72 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -54,14 +54,13 @@ int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
                 if (!dent)
                         return -ENOMEM;
 
-                spin_lock_init(&dent->lock);
                 INIT_LIST_HEAD(&dent->fidlist);
                 dentry->d_fsdata = dent;
         }
 
-        spin_lock(&dent->lock);
+        spin_lock(&dentry->d_lock);
         list_add(&fid->dlist, &dent->fidlist);
-        spin_unlock(&dent->lock);
+        spin_unlock(&dentry->d_lock);
 
         return 0;
 }
@@ -85,14 +84,14 @@ static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
         dent = (struct v9fs_dentry *) dentry->d_fsdata;
         ret = NULL;
         if (dent) {
-                spin_lock(&dent->lock);
+                spin_lock(&dentry->d_lock);
                 list_for_each_entry(fid, &dent->fidlist, dlist) {
                         if (any || uid_eq(fid->uid, uid)) {
                                 ret = fid;
                                 break;
                         }
                 }
-                spin_unlock(&dent->lock);
+                spin_unlock(&dentry->d_lock);
         }
 
         return ret;
diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index bb0b6e7f58fc..469b5d517694 100644
--- a/fs/9p/fid.h
+++ b/fs/9p/fid.h
@@ -25,7 +25,6 @@
 
 /**
  * struct v9fs_dentry - 9p private data stored in dentry d_fsdata
- * @lock: protects the fidlist
  * @fidlist: list of FIDs currently associated with this dentry
  *
  * This structure defines the 9p private data associated with
@@ -35,11 +34,12 @@
  * inodes in order to more closely map functionality to the Plan 9
  * expected behavior for FID reclaimation and tracking.
  *
+ * Protected by ->d_lock of dentry it belongs to.
+ *
  * See Also: Mapping FIDs to Linux VFS model in
  * Design and Implementation of the Linux 9P File System documentation
  */
 struct v9fs_dentry {
-        spinlock_t lock; /* protect fidlist */
         struct list_head fidlist;
 };