Merge tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull dcache updates from Al Viro:
 "Change of locking rules for __dentry_kill(), regularized refcounting
  rules in that area, assorted cleanups and removal of weird corner
  cases (e.g. now ->d_iput() on child is always called before the parent
  might hit __dentry_kill(), etc)"

* tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  dcache: remove unnecessary NULL check in dget_dlock()
  kill DCACHE_MAY_FREE
  __d_unalias() doesn't use inode argument
  d_alloc_parallel(): in-lookup hash insertion doesn't need an RCU variant
  get rid of DCACHE_GENOCIDE
  d_genocide(): move the extern into fs/internal.h
  simple_fill_super(): don't bother with d_genocide() on failure
  nsfs: use d_make_root()
  d_alloc_pseudo(): move setting ->d_op there from the (sole) caller
  kill d_instantate_anon(), fold __d_instantiate_anon() into remaining caller
  retain_dentry(): introduce a trimmed-down lockless variant
  __dentry_kill(): new locking scheme
  d_prune_aliases(): use a shrink list
  switch select_collect{,2}() to use of to_shrink_list()
  to_shrink_list(): call only if refcount is 0
  fold dentry_kill() into dput()
  don't try to cut corners in shrink_lock_dentry()
  fold the call of retain_dentry() into fast_dput()
  Call retain_dentry() with refcount 0
  dentry_kill(): don't bother with retain_dentry() on slow path
  ...

1 files changed, 14 insertions, 56 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 8e6dbe9e0b65..c9f9590f056b 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1242,63 +1242,34 @@ static inline void _nfsd_symlink(struct dentry *parent, const char *name,
 
 #endif
 
-static void clear_ncl(struct inode *inode)
+static void clear_ncl(struct dentry *dentry)
 {
+	struct inode *inode = d_inode(dentry);
 	struct nfsdfs_client *ncl = inode->i_private;
 
+	spin_lock(&inode->i_lock);
 	inode->i_private = NULL;
+	spin_unlock(&inode->i_lock);
 	kref_put(&ncl->cl_ref, ncl->cl_release);
 }
 
-static struct nfsdfs_client *__get_nfsdfs_client(struct inode *inode)
-{
-	struct nfsdfs_client *nc = inode->i_private;
-
-	if (nc)
-		kref_get(&nc->cl_ref);
-	return nc;
-}
-
 struct nfsdfs_client *get_nfsdfs_client(struct inode *inode)
 {
 	struct nfsdfs_client *nc;
 
-	inode_lock_shared(inode);
-	nc = __get_nfsdfs_client(inode);
-	inode_unlock_shared(inode);
+	spin_lock(&inode->i_lock);
+	nc = inode->i_private;
+	if (nc)
+		kref_get(&nc->cl_ref);
+	spin_unlock(&inode->i_lock);
 	return nc;
 }
-/* from __rpc_unlink */
-static void nfsdfs_remove_file(struct inode *dir, struct dentry *dentry)
-{
-	int ret;
-
-	clear_ncl(d_inode(dentry));
-	dget(dentry);
-	ret = simple_unlink(dir, dentry);
-	d_drop(dentry);
-	fsnotify_unlink(dir, dentry);
-	dput(dentry);
-	WARN_ON_ONCE(ret);
-}
-
-static void nfsdfs_remove_files(struct dentry *root)
-{
-	struct dentry *dentry, *tmp;
-
-	list_for_each_entry_safe(dentry, tmp, &root->d_subdirs, d_child) {
-		if (!simple_positive(dentry)) {
-			WARN_ON_ONCE(1); /* I think this can't happen? */
-			continue;
-		}
-		nfsdfs_remove_file(d_inode(root), dentry);
-	}
-}
 
 /* XXX: cut'n'paste from simple_fill_super; figure out if we could share
  * code instead. */
 static  int nfsdfs_create_files(struct dentry *root,
 				const struct tree_descr *files,
+				struct nfsdfs_client *ncl,
 				struct dentry **fdentries)
 {
 	struct inode *dir = d_inode(root);
@@ -1317,8 +1288,9 @@ static  int nfsdfs_create_files(struct dentry *root,
 			dput(dentry);
 			goto out;
 		}
+		kref_get(&ncl->cl_ref);
 		inode->i_fop = files->ops;
-		inode->i_private = __get_nfsdfs_client(dir);
+		inode->i_private = ncl;
 		d_add(dentry, inode);
 		fsnotify_create(dir, dentry);
 		if (fdentries)
@@ -1327,7 +1299,6 @@ static  int nfsdfs_create_files(struct dentry *root,
 	inode_unlock(dir);
 	return 0;
 out:
-	nfsdfs_remove_files(root);
 	inode_unlock(dir);
 	return -ENOMEM;
 }
@@ -1347,7 +1318,7 @@ struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
 	dentry = nfsd_mkdir(nn->nfsd_client_dir, ncl, name);
 	if (IS_ERR(dentry)) /* XXX: tossing errors? */
 		return NULL;
-	ret = nfsdfs_create_files(dentry, files, fdentries);
+	ret = nfsdfs_create_files(dentry, files, ncl, fdentries);
 	if (ret) {
 		nfsd_client_rmdir(dentry);
 		return NULL;
@@ -1358,20 +1329,7 @@ struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
 /* Taken from __rpc_rmdir: */
 void nfsd_client_rmdir(struct dentry *dentry)
 {
-	struct inode *dir = d_inode(dentry->d_parent);
-	struct inode *inode = d_inode(dentry);
-	int ret;
-
-	inode_lock(dir);
-	nfsdfs_remove_files(dentry);
-	clear_ncl(inode);
-	dget(dentry);
-	ret = simple_rmdir(dir, dentry);
-	WARN_ON_ONCE(ret);
-	d_drop(dentry);
-	fsnotify_rmdir(dir, dentry);
-	dput(dentry);
-	inode_unlock(dir);
+	simple_recursive_removal(dentry, clear_ncl);
 }
 
 static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)