+static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data)
+{
+ struct rpc_message msg = {
+ .rpc_argp = &data->args,
+ .rpc_resp = &data->res,
+ .rpc_cred = data->cred,
+ };
+ struct rpc_task_setup task_setup_data = {
+ .rpc_message = &msg,
+ .callback_ops = &nfs_unlink_ops,
+ .callback_data = data,
+ .flags = RPC_TASK_ASYNC,
+ };
+ struct rpc_task *task;
+ struct dentry *alias;
+
+ alias = d_lookup(parent, &data->args.name);
+ if (alias != NULL) {
+ int ret = 0;
+
+ /*
+ * Hey, we raced with lookup... See if we need to transfer
+ * the sillyrename information to the aliased dentry.
+ */
+ nfs_free_dname(data);
+ spin_lock(&alias->d_lock);
+ if (alias->d_inode != NULL &&
+ !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
+ alias->d_fsdata = data;
+ alias->d_flags |= DCACHE_NFSFS_RENAMED;
+ ret = 1;
+ }
+ spin_unlock(&alias->d_lock);
+ nfs_dec_sillycount(dir);
+ dput(alias);
+ return ret;
+ }
+ data->dir = igrab(dir);
+ if (!data->dir) {
+ nfs_dec_sillycount(dir);
+ return 0;
+ }
+ nfs_sb_active(NFS_SERVER(dir));
+ data->args.fh = NFS_FH(dir);
+ nfs_fattr_init(&data->res.dir_attr);
+
+ NFS_PROTO(dir)->unlink_setup(&msg, dir);
+
+ task_setup_data.rpc_client = NFS_CLIENT(dir);
+ task = rpc_run_task(&task_setup_data);
+ if (!IS_ERR(task))
+ rpc_put_task(task);
+ return 1;
+}
+
+static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data)
+{
+ struct dentry *parent;
+ struct inode *dir;
+ int ret = 0;
+
+
+ parent = dget_parent(dentry);
+ if (parent == NULL)
+ goto out_free;
+ dir = parent->d_inode;
+ if (nfs_copy_dname(dentry, data) != 0)
+ goto out_dput;
+ /* Non-exclusive lock protects against concurrent lookup() calls */
+ spin_lock(&dir->i_lock);
+ if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) {
+ /* Deferred delete */
+ hlist_add_head(&data->list, &NFS_I(dir)->silly_list);
+ spin_unlock(&dir->i_lock);
+ ret = 1;
+ goto out_dput;
+ }
+ spin_unlock(&dir->i_lock);
+ ret = nfs_do_call_unlink(parent, dir, data);
+out_dput:
+ dput(parent);
+out_free:
+ return ret;
+}
+
+void nfs_block_sillyrename(struct dentry *dentry)
+{
+ struct nfs_inode *nfsi = NFS_I(dentry->d_inode);
+
+ wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1);
+}
+
+void nfs_unblock_sillyrename(struct dentry *dentry)
+{
+ struct inode *dir = dentry->d_inode;
+ struct nfs_inode *nfsi = NFS_I(dir);
+ struct nfs_unlinkdata *data;
+
+ atomic_inc(&nfsi->silly_count);
+ spin_lock(&dir->i_lock);
+ while (!hlist_empty(&nfsi->silly_list)) {
+ if (!atomic_inc_not_zero(&nfsi->silly_count))
+ break;
+ data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list);
+ hlist_del(&data->list);
+ spin_unlock(&dir->i_lock);
+ if (nfs_do_call_unlink(dentry, dir, data) == 0)
+ nfs_free_unlinkdata(data);
+ spin_lock(&dir->i_lock);
+ }
+ spin_unlock(&dir->i_lock);
+}
+