+static inline struct nfs_rw_header *NFS_RW_HEADER(struct nfs_pgio_header *hdr)
+{
+ return container_of(hdr, struct nfs_rw_header, header);
+}
+
+/**
+ * nfs_rw_header_alloc - Allocate a header for a read or write
+ * @ops: Read or write function vector
+ */
+struct nfs_rw_header *nfs_rw_header_alloc(const struct nfs_rw_ops *ops)
+{
+ struct nfs_rw_header *header = ops->rw_alloc_header();
+
+ if (header) {
+ struct nfs_pgio_header *hdr = &header->header;
+
+ INIT_LIST_HEAD(&hdr->pages);
+ spin_lock_init(&hdr->lock);
+ atomic_set(&hdr->refcnt, 0);
+ hdr->rw_ops = ops;
+ }
+ return header;
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_alloc);
+
+/*
+ * nfs_rw_header_free - Free a read or write header
+ * @hdr: The header to free
+ */
+void nfs_rw_header_free(struct nfs_pgio_header *hdr)
+{
+ hdr->rw_ops->rw_free_header(NFS_RW_HEADER(hdr));
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_free);
+
+/**
+ * nfs_pgio_data_alloc - Allocate pageio data
+ * @hdr: The header making a request
+ * @pagecount: Number of pages to create
+ */
+static struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr,
+ unsigned int pagecount)
+{
+ struct nfs_pgio_data *data, *prealloc;
+
+ prealloc = &NFS_RW_HEADER(hdr)->rpc_data;
+ if (prealloc->header == NULL)
+ data = prealloc;
+ else
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ goto out;
+
+ if (nfs_pgarray_set(&data->pages, pagecount)) {
+ data->header = hdr;
+ atomic_inc(&hdr->refcnt);
+ } else {
+ if (data != prealloc)
+ kfree(data);
+ data = NULL;
+ }
+out:
+ return data;
+}
+
+/**
+ * nfs_pgio_data_release - Properly free pageio data
+ * @data: The data to release
+ */
+void nfs_pgio_data_release(struct nfs_pgio_data *data)
+{
+ struct nfs_pgio_header *hdr = data->header;
+ struct nfs_rw_header *pageio_header = NFS_RW_HEADER(hdr);
+
+ put_nfs_open_context(data->args.context);
+ if (data->pages.pagevec != data->pages.page_array)
+ kfree(data->pages.pagevec);
+ if (data == &pageio_header->rpc_data) {
+ data->header = NULL;
+ data = NULL;
+ }
+ if (atomic_dec_and_test(&hdr->refcnt))
+ hdr->completion_ops->completion(hdr);
+ /* Note: we only free the rpc_task after callbacks are done.
+ * See the comment in rpc_free_task() for why
+ */
+ kfree(data);
+}
+EXPORT_SYMBOL_GPL(nfs_pgio_data_release);
+
+/**
+ * nfs_pgio_rpcsetup - Set up arguments for a pageio call
+ * @data: The pageio data
+ * @count: Number of bytes to read
+ * @offset: Initial offset
+ * @how: How to commit data (writes only)
+ * @cinfo: Commit information for the call (writes only)
+ */
+static void nfs_pgio_rpcsetup(struct nfs_pgio_data *data,
+ unsigned int count, unsigned int offset,
+ int how, struct nfs_commit_info *cinfo)
+{
+ struct nfs_page *req = data->header->req;
+
+ /* Set up the RPC argument and reply structs
+ * NB: take care not to mess about with data->commit et al. */
+
+ data->args.fh = NFS_FH(data->header->inode);
+ data->args.offset = req_offset(req) + offset;
+ /* pnfs_set_layoutcommit needs this */
+ data->mds_offset = data->args.offset;
+ data->args.pgbase = req->wb_pgbase + offset;
+ data->args.pages = data->pages.pagevec;
+ data->args.count = count;
+ data->args.context = get_nfs_open_context(req->wb_context);
+ data->args.lock_context = req->wb_lock_context;
+ data->args.stable = NFS_UNSTABLE;
+ switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
+ case 0:
+ break;
+ case FLUSH_COND_STABLE:
+ if (nfs_reqs_to_commit(cinfo))
+ break;
+ default:
+ data->args.stable = NFS_FILE_SYNC;
+ }
+
+ data->res.fattr = &data->fattr;
+ data->res.count = count;
+ data->res.eof = 0;
+ data->res.verf = &data->verf;
+ nfs_fattr_init(&data->fattr);
+}
+
+/**
+ * nfs_pgio_prepare - Prepare pageio data to go over the wire
+ * @task: The current task
+ * @calldata: pageio data to prepare
+ */
+static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
+{
+ struct nfs_pgio_data *data = calldata;
+ int err;
+ err = NFS_PROTO(data->header->inode)->pgio_rpc_prepare(task, data);
+ if (err)
+ rpc_exit(task, err);
+}
+
+int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_data *data,
+ const struct rpc_call_ops *call_ops, int how, int flags)
+{
+ struct rpc_task *task;
+ struct rpc_message msg = {
+ .rpc_argp = &data->args,
+ .rpc_resp = &data->res,
+ .rpc_cred = data->header->cred,
+ };
+ struct rpc_task_setup task_setup_data = {
+ .rpc_client = clnt,
+ .task = &data->task,
+ .rpc_message = &msg,
+ .callback_ops = call_ops,
+ .callback_data = data,
+ .workqueue = nfsiod_workqueue,
+ .flags = RPC_TASK_ASYNC | flags,
+ };
+ int ret = 0;
+
+ data->header->rw_ops->rw_initiate(data, &msg, &task_setup_data, how);
+
+ dprintk("NFS: %5u initiated pgio call "
+ "(req %s/%llu, %u bytes @ offset %llu)\n",
+ data->task.tk_pid,
+ data->header->inode->i_sb->s_id,
+ (unsigned long long)NFS_FILEID(data->header->inode),
+ data->args.count,
+ (unsigned long long)data->args.offset);
+
+ task = rpc_run_task(&task_setup_data);
+ if (IS_ERR(task)) {
+ ret = PTR_ERR(task);
+ goto out;
+ }
+ if (how & FLUSH_SYNC) {
+ ret = rpc_wait_for_completion_task(task);
+ if (ret == 0)
+ ret = task->tk_status;
+ }
+ rpc_put_task(task);
+out:
+ return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
+
+/**
+ * nfs_pgio_error - Clean up from a pageio error
+ * @desc: IO descriptor
+ * @hdr: pageio header
+ */
+static int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
+ struct nfs_pgio_header *hdr)
+{
+ set_bit(NFS_IOHDR_REDO, &hdr->flags);
+ nfs_pgio_data_release(hdr->data);
+ hdr->data = NULL;
+ desc->pg_completion_ops->error_cleanup(&desc->pg_list);
+ return -ENOMEM;
+}
+
+/**
+ * nfs_pgio_release - Release pageio data
+ * @calldata: The pageio data to release
+ */
+static void nfs_pgio_release(void *calldata)
+{
+ struct nfs_pgio_data *data = calldata;
+ if (data->header->rw_ops->rw_release)
+ data->header->rw_ops->rw_release(data);
+ nfs_pgio_data_release(data);
+}
+