[PATCH] PATCH 8/16: NFSD: RPC lists tidyup

Change sunrpc to use more list.h lists

The sunrpc client code uses home-grown doubly linked
lists to group
   - idle server threads
   - pending server sockets
   - waiting rpc tasks
   - all rpc tasks.

This patch converts all of these lists to <linux/list.h> lists and
also makes the list of all server sockets for a particular server into
a list.h list instead of a single-link list.

Possibly the least obvious change is replacing RPC_INIT_WAITQ
with RPC_WAITQ and INIT_RPC_WAITQ.  These follow the model of
LIST_HEAD and INIT_LIST_HEAD defined in list.h and are needed
to initialise the list_head in the rpc_waitq properly.

4 files changed, 34 insertions, 70 deletions

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index eee6756b842a..892565ca4721 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -34,13 +34,11 @@ struct rpc_message {
  * This is the RPC task struct
  */
 struct rpc_task {
-	struct rpc_task *	tk_prev;	/* wait queue links */
-	struct rpc_task *	tk_next;
+	struct list_head	tk_list;	/* wait queue links */
 #ifdef RPC_DEBUG
 	unsigned long		tk_magic;	/* 0xf00baa */
 #endif
-	struct rpc_task *	tk_next_task;	/* global list of tasks */
-	struct rpc_task *	tk_prev_task;	/* global list of tasks */
+	struct list_head	tk_task;	/* global list of tasks */
 	struct rpc_clnt *	tk_client;	/* RPC client */
 	struct rpc_rqst *	tk_rqstp;	/* RPC request */
 	int			tk_status;	/* result of last operation */
@@ -88,6 +86,20 @@ struct rpc_task {
 #define tk_auth			tk_client->cl_auth
 #define tk_xprt			tk_client->cl_xprt
 
+/* support walking a list of tasks on a wait queue */
+#define	task_for_each(task, pos, head) \
+	list_for_each(pos, head) \
+		if ((task=list_entry(pos, struct rpc_task, tk_list)),1)
+
+#define	task_for_first(task, head) \
+	if (!list_empty(head) &&  \
+	    ((task=list_entry((head)->next, struct rpc_task, tk_list)),1))
+
+/* .. and walking list of all tasks */
+#define	alltask_for_each(task, pos, head) \
+	list_for_each(pos, head) \
+		if ((task=list_entry(pos, struct rpc_task, tk_task)),1)
+
 typedef void			(*rpc_action)(struct rpc_task *);
 
 /*
@@ -133,16 +145,24 @@ typedef void			(*rpc_action)(struct rpc_task *);
  * RPC synchronization objects
  */
 struct rpc_wait_queue {
-	struct rpc_task *	task;
+	struct list_head	tasks;
 #ifdef RPC_DEBUG
 	char *			name;
 #endif
 };
 
 #ifndef RPC_DEBUG
-# define RPC_INIT_WAITQ(name)	((struct rpc_wait_queue) { NULL })
+# define RPC_WAITQ_INIT(var,qname) ((struct rpc_wait_queue) {LIST_HEAD_INIT(var)})
+# define RPC_WAITQ(var,qname)      struct rpc_wait_queue var = RPC_WAITQ_INIT(var.tasks,qname)
+# define INIT_RPC_WAITQ(ptr,qname) do { \
+	INIT_LIST_HEAD(&(ptr)->tasks); \
+	} while(0)
 #else
-# define RPC_INIT_WAITQ(name)	((struct rpc_wait_queue) { NULL, name })
+# define RPC_WAITQ_INIT(var,qname) ((struct rpc_wait_queue) {LIST_HEAD_INIT(var.tasks), qname})
+# define RPC_WAITQ(var,qname)      struct rpc_wait_queue var = RPC_WAITQ_INIT(var,qname)
+# define INIT_RPC_WAITQ(ptr,qname) do { \
+	INIT_LIST_HEAD(&(ptr)->tasks); (ptr)->name = qname; \
+	} while(0)
 #endif
 
 /*
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index f6439cb4facf..003b89a68852 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -27,8 +27,8 @@
  * We currently do not support more than one RPC program per daemon.
  */
 struct svc_serv {
-	struct svc_rqst *	sv_threads;	/* idle server threads */
-	struct svc_sock *	sv_sockets;	/* pending sockets */
+	struct list_head	sv_threads;	/* idle server threads */
+	struct list_head	sv_sockets;	/* pending sockets */
 	struct svc_program *	sv_program;	/* RPC program */
 	struct svc_stat *	sv_stats;	/* RPC statistics */
 	spinlock_t		sv_lock;
@@ -36,7 +36,7 @@ struct svc_serv {
 	unsigned int		sv_bufsz;	/* datagram buffer size */
 	unsigned int		sv_xdrsize;	/* XDR buffer size */
 
-	struct svc_sock *	sv_allsocks;	/* all sockets */
+	struct list_head	sv_allsocks;	/* all sockets */
 
 	char *			sv_name;	/* service name */
 };
@@ -89,8 +89,7 @@ struct svc_buf {
  * NOTE: First two items must be prev/next.
  */
 struct svc_rqst {
-	struct svc_rqst *	rq_prev;	/* idle list */
-	struct svc_rqst *	rq_next;
+	struct list_head	rq_list;	/* idle list */
 	struct svc_sock *	rq_sock;	/* socket */
 	struct sockaddr_in	rq_addr;	/* peer address */
 	int			rq_addrlen;
diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index 82d9678d4905..0c565502e272 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -13,12 +13,10 @@
 
 /*
  * RPC server socket.
- * NOTE: First two items must be prev/next.
  */
 struct svc_sock {
-	struct svc_sock *	sk_prev;	/* list of ready sockets */
-	struct svc_sock *	sk_next;
-	struct svc_sock *	sk_list;	/* list of all sockets */
+	struct list_head	sk_ready;	/* list of ready sockets */
+	struct list_head	sk_list;	/* list of all sockets */
 	struct socket *		sk_sock;	/* berkeley socket layer */
 	struct sock *		sk_sk;		/* INET layer */
 	spinlock_t		sk_lock;
diff --git a/include/linux/sunrpc/types.h b/include/linux/sunrpc/types.h
index 232ac45c725e..d524016fb4ba 100644
--- a/include/linux/sunrpc/types.h
+++ b/include/linux/sunrpc/types.h
@@ -12,60 +12,7 @@
 #include <linux/timer.h>
 #include <linux/tqueue.h>
 #include <linux/sunrpc/debug.h>
-
-/*
- * These are the RPC list manipulation primitives used everywhere.
- */
-struct rpc_listitem	{
-	struct rpc_listitem *	prev;
-	struct rpc_listitem *	next;
-};
-
-static __inline__ void
-__rpc_append_list(struct rpc_listitem **q, struct rpc_listitem *item)
-{
-	struct rpc_listitem	*next, *prev;
-
-	if (!(next = *q)) {
-		*q = item->next = item->prev = item;
-	} else {
-		prev = next->prev;
-		prev->next = item;
-		next->prev = item;
-		item->next = next;
-		item->prev = prev;
-	}
-}
-
-static __inline__ void
-__rpc_insert_list(struct rpc_listitem **q, struct rpc_listitem *item)
-{
-	__rpc_append_list(q, item);
-	*q = item;
-}
-
-static __inline__ void
-__rpc_remove_list(struct rpc_listitem **q, struct rpc_listitem *item)
-{
-	struct rpc_listitem	*prev = item->prev,
-				*next = item->next;
-
-	if (item != prev) {
-		next->prev = prev;
-		prev->next = next;
-	} else {
-		next = NULL;
-	}
-	if (*q == item)
-		*q = next;
-}
-
-#define rpc_insert_list(q, i) \
-      __rpc_insert_list((struct rpc_listitem **) q, (struct rpc_listitem *) i)
-#define rpc_append_list(q, i) \
-      __rpc_append_list((struct rpc_listitem **) q, (struct rpc_listitem *) i)
-#define rpc_remove_list(q, i) \
-      __rpc_remove_list((struct rpc_listitem **) q, (struct rpc_listitem *) i)
+#include <linux/list.h>
 
 /*
  * Shorthands