patch-1.3.82 linux/fs/nfs/nfsiod.c

• Lines: 129
• Date: Sat Mar 30 23:54:23 1996
• Orig file: v1.3.81/linux/fs/nfs/nfsiod.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.81/linux/fs/nfs/nfsiod.c linux/fs/nfs/nfsiod.c
@@ -0,0 +1,128 @@
+/*
+ * linux/fs/nfs/nfsiod.c
+ *
+ * Async NFS RPC call support.
+ *
+ * When a process wants to place an asynchronous RPC call, it reserves
+ * an nfsiod slot, fills in all necessary fields including the callback
+ * handler field, and enqueues the request.
+ *
+ * This will wake up nfsiod, which calls nfs_rpc_doio to collect the
+ * reply. It then dispatches the result to the caller via the callback
+ * function, including result value and request pointer. It then re-inserts
+ * itself into the free list.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sched.h>
+#include <linux/nfs_fs.h>
+#include <linux/errno.h>
+#include <linux/rpcsock.h>
+#include <linux/nfsiod.h>
+
+static struct nfsiod_req *	free_list = NULL;
+static int			active = 0;
+
+#undef DEBUG_NFSIOD
+#ifdef DEBUG_NFSIOD
+#define dprintk(args...)	printk(## args)
+#else
+#define dprintk(args...)	/* nothing */
+#endif
+
+
+/*
+ * Reserve an nfsiod slot and initialize the request struct
+ */
+struct nfsiod_req *
+nfsiod_reserve(struct nfs_server *server, nfsiod_done_fn_t callback)
+{
+	struct nfsiod_req	*req;
+
+	if (!(req = free_list)) {
+		dprintk("BIO: nfsiod_reserve: no free nfsiods\n");
+		return NULL;
+	}
+	free_list = req->rq_next;
+	memset(&req->rq_rpcreq, 0, sizeof(struct rpc_ioreq));
+
+	if (rpc_reserve(server->rsock, &req->rq_rpcreq, 1) < 0) {
+		dprintk("BIO: nfsiod_reserve failed to reserve RPC slot\n");
+		req->rq_next = free_list;
+		free_list = req;
+		return NULL;
+	}
+
+	req->rq_server = server;
+	req->rq_callback = callback;
+
+	return req;
+}
+
+void
+nfsiod_release(struct nfsiod_req *req)
+{
+	dprintk("BIO: nfsiod_release called\n");
+	rpc_release(req->rq_server->rsock, &req->rq_rpcreq);
+	memset(&req->rq_rpcreq, 0, sizeof(struct rpc_ioreq));
+	req->rq_next = free_list;
+	free_list = req;
+}
+
+/*
+ * Transmit a request and put it on nfsiod's list of pending requests.
+ */
+int
+nfsiod_enqueue(struct nfsiod_req *req)
+{
+	int	result;
+
+	dprintk("BIO: enqueuing request %p\n", &req->rq_rpcreq);
+	result = rpc_transmit(req->rq_server->rsock, &req->rq_rpcreq);
+	if (result < 0) {
+		dprintk("BIO: rpc_transmit returned %d\n", result);
+	} else {
+		dprintk("BIO: waking up nfsiod (%p)\n", req->rq_wait);
+		wake_up(&req->rq_wait);
+		schedule();
+	}
+	return result;
+}
+
+/*
+ * This is the main nfsiod loop.
+ */
+int
+nfsiod(void)
+{
+	struct nfsiod_req	request, *req = &request;
+	int			result;
+
+	dprintk("BIO: nfsiod %d starting\n", current->pid);
+	while (1) {
+		/* Insert request into free list */
+		memset(req, 0, sizeof(*req));
+		req->rq_next = free_list;
+		free_list = req;
+
+		/* Wait until user enqueues request */
+		dprintk("BIO: before: now %d nfsiod's active\n", active);
+		dprintk("BIO: nfsiod %d waiting\n", current->pid);
+		interruptible_sleep_on(&req->rq_wait);
+
+		if (current->signal & ~current->blocked)
+			break;
+		if (!req->rq_rpcreq.rq_slot)
+			continue;
+		dprintk("BIO: nfsiod %d woken up; calling nfs_rpc_doio.\n",
+				current->pid);
+		active++;
+		dprintk("BIO: before: now %d nfsiod's active\n", active);
+		result = nfs_rpc_doio(req->rq_server, &req->rq_rpcreq, 1);
+		req->rq_callback(result, req);
+		active--;
+	}
+
+	return 0;
+}