1 files changed, 227 insertions, 0 deletions
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
new file mode 100644
index 0000000..f732541
--- /dev/null
+++ b/fs/nfs/unlink.c
@@ -0,0 +1,227 @@
+/*
+ *  linux/fs/nfs/unlink.c
+ *
+ * nfs sillydelete handling
+ *
+ * NOTE: we rely on holding the BKL for list manipulation protection.
+ */
+
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/dcache.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+
+
+struct nfs_unlinkdata {
+	struct nfs_unlinkdata	*next;
+	struct dentry	*dir, *dentry;
+	struct qstr	name;
+	struct rpc_task	task;
+	struct rpc_cred	*cred;
+	unsigned int	count;
+};
+
+static struct nfs_unlinkdata	*nfs_deletes;
+static RPC_WAITQ(nfs_delete_queue, "nfs_delete_queue");
+
+/**
+ * nfs_detach_unlinkdata - Remove asynchronous unlink from global list
+ * @data: pointer to descriptor
+ */
+static inline void
+nfs_detach_unlinkdata(struct nfs_unlinkdata *data)
+{
+	struct nfs_unlinkdata	**q;
+
+	for (q = &nfs_deletes; *q != NULL; q = &((*q)->next)) {
+		if (*q == data) {
+			*q = data->next;
+			break;
+		}
+	}
+}
+
+/**
+ * nfs_put_unlinkdata - release data from a sillydelete operation.
+ * @data: pointer to unlink structure.
+ */
+static void
+nfs_put_unlinkdata(struct nfs_unlinkdata *data)
+{
+	if (--data->count == 0) {
+		nfs_detach_unlinkdata(data);
+		if (data->name.name != NULL)
+			kfree(data->name.name);
+		kfree(data);
+	}
+}
+
+#define NAME_ALLOC_LEN(len)	((len+16) & ~15)
+/**
+ * nfs_copy_dname - copy dentry name to data structure
+ * @dentry: pointer to dentry
+ * @data: nfs_unlinkdata
+ */
+static inline void
+nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data)
+{
+	char		*str;
+	int		len = dentry->d_name.len;
+
+	str = kmalloc(NAME_ALLOC_LEN(len), GFP_KERNEL);
+	if (!str)
+		return;
+	memcpy(str, dentry->d_name.name, len);
+	if (!data->name.len) {
+		data->name.len = len;
+		data->name.name = str;
+	} else
+		kfree(str);
+}
+
+/**
+ * nfs_async_unlink_init - Initialize the RPC info
+ * @task: rpc_task of the sillydelete
+ *
+ * We delay initializing RPC info until after the call to dentry_iput()
+ * in order to minimize races against rename().
+ */
+static void
+nfs_async_unlink_init(struct rpc_task *task)
+{
+	struct nfs_unlinkdata	*data = (struct nfs_unlinkdata *)task->tk_calldata;
+	struct dentry		*dir = data->dir;
+	struct rpc_message	msg = {
+		.rpc_cred	= data->cred,
+	};
+	int			status = -ENOENT;
+
+	if (!data->name.len)
+		goto out_err;
+
+	status = NFS_PROTO(dir->d_inode)->unlink_setup(&msg, dir, &data->name);
+	if (status < 0)
+		goto out_err;
+	nfs_begin_data_update(dir->d_inode);
+	rpc_call_setup(task, &msg, 0);
+	return;
+ out_err:
+	rpc_exit(task, status);
+}
+
+/**
+ * nfs_async_unlink_done - Sillydelete post-processing
+ * @task: rpc_task of the sillydelete
+ *
+ * Do the directory attribute update.
+ */
+static void
+nfs_async_unlink_done(struct rpc_task *task)
+{
+	struct nfs_unlinkdata	*data = (struct nfs_unlinkdata *)task->tk_calldata;
+	struct dentry		*dir = data->dir;
+	struct inode		*dir_i;
+
+	if (!dir)
+		return;
+	dir_i = dir->d_inode;
+	nfs_end_data_update(dir_i);
+	if (NFS_PROTO(dir_i)->unlink_done(dir, task))
+		return;
+	put_rpccred(data->cred);
+	data->cred = NULL;
+	dput(dir);
+}
+
+/**
+ * nfs_async_unlink_release - Release the sillydelete data.
+ * @task: rpc_task of the sillydelete
+ *
+ * We need to call nfs_put_unlinkdata as a 'tk_release' task since the
+ * rpc_task would be freed too.
+ */
+static void
+nfs_async_unlink_release(struct rpc_task *task)
+{
+	struct nfs_unlinkdata	*data = (struct nfs_unlinkdata *)task->tk_calldata;
+	nfs_put_unlinkdata(data);
+}
+
+/**
+ * nfs_async_unlink - asynchronous unlinking of a file
+ * @dentry: dentry to unlink
+ */
+int
+nfs_async_unlink(struct dentry *dentry)
+{
+	struct dentry	*dir = dentry->d_parent;
+	struct nfs_unlinkdata	*data;
+	struct rpc_task	*task;
+	struct rpc_clnt	*clnt = NFS_CLIENT(dir->d_inode);
+	int		status = -ENOMEM;
+
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		goto out;
+	memset(data, 0, sizeof(*data));
+
+	data->cred = rpcauth_lookupcred(clnt->cl_auth, 0);
+	if (IS_ERR(data->cred)) {
+		status = PTR_ERR(data->cred);
+		goto out_free;
+	}
+	data->dir = dget(dir);
+	data->dentry = dentry;
+
+	data->next = nfs_deletes;
+	nfs_deletes = data;
+	data->count = 1;
+
+	task = &data->task;
+	rpc_init_task(task, clnt, nfs_async_unlink_done , RPC_TASK_ASYNC);
+	task->tk_calldata = data;
+	task->tk_action = nfs_async_unlink_init;
+	task->tk_release = nfs_async_unlink_release;
+
+	spin_lock(&dentry->d_lock);
+	dentry->d_flags |= DCACHE_NFSFS_RENAMED;
+	spin_unlock(&dentry->d_lock);
+
+	rpc_sleep_on(&nfs_delete_queue, task, NULL, NULL);
+	status = 0;
+ out:
+	return status;
+out_free:
+	kfree(data);
+	return status;
+}
+
+/**
+ * nfs_complete_unlink - Initialize completion of the sillydelete
+ * @dentry: dentry to delete
+ *
+ * Since we're most likely to be called by dentry_iput(), we
+ * only use the dentry to find the sillydelete. We then copy the name
+ * into the qstr.
+ */
+void
+nfs_complete_unlink(struct dentry *dentry)
+{
+	struct nfs_unlinkdata	*data;
+
+	for(data = nfs_deletes; data != NULL; data = data->next) {
+		if (dentry == data->dentry)
+			break;
+	}
+	if (!data)
+		return;
+	data->count++;
+	nfs_copy_dname(dentry, data);
+	spin_lock(&dentry->d_lock);
+	dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
+	spin_unlock(&dentry->d_lock);
+	rpc_wake_up_task(&data->task);
+	nfs_put_unlinkdata(data);
+}