9p: consolidate transport structure

Right now there is a transport module structure which provides per-transport
type functions and data and a transport structure which contains per-instance
public data as well as function pointers to instance specific functions.

This patch moves public transport visible instance data to the client
structure (which in some cases had duplicate data) and consolidates the
functions into the transport module structure.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

fs/9p/v9fs.c

@@ -30,8 +30,8 @@
 #include <linux/parser.h>
 #include <linux/idr.h>
 #include <net/9p/9p.h>
-#include <net/9p/transport.h>
 #include <net/9p/client.h>
+#include <net/9p/transport.h>
 #include "v9fs.h"
 #include "v9fs_vfs.h"
 

include/net/9p/client.h

@@ -26,6 +26,22 @@
 #ifndef NET_9P_CLIENT_H
 #define NET_9P_CLIENT_H
 
+/**
+ * enum p9_trans_status - different states of underlying transports
+ * @Connected: transport is connected and healthy
+ * @Disconnected: transport has been disconnected
+ * @Hung: transport is connected by wedged
+ *
+ * This enumeration details the various states a transport
+ * instatiation can be in.
+ */
+
+enum p9_trans_status {
+	Connected,
+	Disconnected,
+	Hung,
+};
+
 /**
  * struct p9_client - per client instance state
  * @lock: protect @fidlist
@@ -48,7 +64,8 @@ struct p9_client {
 	int msize;
 	unsigned char dotu;
 	struct p9_trans_module *trans_mod;
-	struct p9_trans *trans;
+	enum p9_trans_status status;
+	void *trans;
 	struct p9_conn *conn;
 
 	struct p9_idpool *fidpool;

include/net/9p/transport.h

@@ -26,52 +26,6 @@
 #ifndef NET_9P_TRANSPORT_H
 #define NET_9P_TRANSPORT_H
 
-#include <linux/module.h>
-
-/**
- * enum p9_trans_status - different states of underlying transports
- * @Connected: transport is connected and healthy
- * @Disconnected: transport has been disconnected
- * @Hung: transport is connected by wedged
- *
- * This enumeration details the various states a transport
- * instatiation can be in.
- */
-
-enum p9_trans_status {
-	Connected,
-	Disconnected,
-	Hung,
-};
-
-/**
- * struct p9_trans - per-transport state and API
- * @status: transport &p9_trans_status
- * @msize: negotiated maximum packet size (duplicate from client)
- * @extended: negotiated protocol extensions (duplicate from client)
- * @priv: transport private data
- * @close: member function to disconnect and close the transport
- * @rpc: member function to issue a request to the transport
- *
- * This is the basic API for a transport instance.  It is used as
- * a handle by the client to issue requests.  This interface is currently
- * in flux during reorganization.
- *
- * Bugs: there is lots of duplicated data here and its not clear that
- * the member functions need to be per-instance versus per transport
- * module.
- */
-
-struct p9_trans {
-	enum p9_trans_status status;
-	int msize;
-	unsigned char extended;
-	void *priv;
-	void (*close) (struct p9_trans *);
-	int (*rpc) (struct p9_trans *t, struct p9_fcall *tc,
-							struct p9_fcall **rc);
-};
-
 /**
  * struct p9_trans_module - transport module interface
  * @list: used to maintain a list of currently available transports
@@ -79,12 +33,14 @@ struct p9_trans {
  * @maxsize: transport provided maximum packet size
  * @def: set if this transport should be considered the default
  * @create: member function to create a new connection on this transport
+ * @close: member function to disconnect and close the transport
+ * @rpc: member function to issue a request to the transport
  *
  * This is the basic API for a transport module which is registered by the
  * transport module with the 9P core network module and used by the client
  * to instantiate a new connection on a transport.
  *
- * Bugs: the transport module list isn't protected.
+ * BUGS: the transport module list isn't protected.
  */
 
 struct p9_trans_module {
@@ -92,8 +48,11 @@ struct p9_trans_module {
 	char *name;		/* name of transport */
 	int maxsize;		/* max message size of transport */
 	int def;		/* this transport should be default */
-	struct p9_trans * (*create)(const char *, char *, int, unsigned char);
 	struct module *owner;
+	int (*create)(struct p9_client *, const char *, char *);
+	void (*close) (struct p9_client *);
+	int (*rpc) (struct p9_client *t, struct p9_fcall *tc,
+							struct p9_fcall **rc);
 };
 
 void v9fs_register_trans(struct p9_trans_module *m);

net/9p/client.c

@@ -33,8 +33,8 @@
 #include <linux/uaccess.h>
 #include <net/9p/9p.h>
 #include <linux/parser.h>
-#include <net/9p/transport.h>
 #include <net/9p/client.h>
+#include <net/9p/transport.h>
 
 static struct p9_fid *p9_fid_create(struct p9_client *clnt);
 static void p9_fid_destroy(struct p9_fid *fid);
@@ -136,7 +136,7 @@ int
 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc,
 	struct p9_fcall **rc)
 {
-	return c->trans->rpc(c->trans, tc, rc);
+	return c->trans_mod->rpc(c, tc, rc);
 }
 
 struct p9_client *p9_client_create(const char *dev_name, char *options)
@@ -179,13 +179,9 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
 		clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 
 
-	clnt->trans = clnt->trans_mod->create(dev_name, options, clnt->msize,
-								clnt->dotu);
-	if (IS_ERR(clnt->trans)) {
-		err = PTR_ERR(clnt->trans);
-		clnt->trans = NULL;
+	err = clnt->trans_mod->create(clnt, dev_name, options);
+	if (err)
 		goto error;
-	}
 
 	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
@@ -233,11 +229,8 @@ void p9_client_destroy(struct p9_client *clnt)
 
 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 
-	if (clnt->trans) {
-		clnt->trans->close(clnt->trans);
-		kfree(clnt->trans);
-		clnt->trans = NULL;
-	}
+	if (clnt->trans_mod)
+		clnt->trans_mod->close(clnt);
 
 	v9fs_put_trans(clnt->trans_mod);
 
@@ -254,7 +247,7 @@ EXPORT_SYMBOL(p9_client_destroy);
 void p9_client_disconnect(struct p9_client *clnt)
 {
 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
-	clnt->trans->status = Disconnected;
+	clnt->status = Disconnected;
 }
 EXPORT_SYMBOL(p9_client_disconnect);
 

net/9p/mod.c

@@ -29,6 +29,7 @@
 #include <net/9p/9p.h>
 #include <linux/fs.h>
 #include <linux/parser.h>
+#include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>

net/9p/trans_virtio.c

@@ -41,6 +41,7 @@
 #include <linux/file.h>
 #include <net/9p/9p.h>
 #include <linux/parser.h>
+#include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include <linux/scatterlist.h>
 #include <linux/virtio.h>
@@ -55,7 +56,6 @@ static int chan_index;
 
 #define P9_INIT_MAXTAG	16
 
-
 /**
  * enum p9_req_status_t - virtio request status
  * @REQ_STATUS_IDLE: request slot unused
@@ -197,9 +197,9 @@ static unsigned int rest_of_page(void *data)
  *
  */
 
-static void p9_virtio_close(struct p9_trans *trans)
+static void p9_virtio_close(struct p9_client *client)
 {
-	struct virtio_chan *chan = trans->priv;
+	struct virtio_chan *chan = client->trans;
 	int count;
 	unsigned long flags;
 
@@ -215,7 +215,7 @@ static void p9_virtio_close(struct p9_trans *trans)
 	chan->inuse = false;
 	mutex_unlock(&virtio_9p_lock);
 
-	kfree(trans);
+	client->trans = NULL;
 }
 
 /**
@@ -292,17 +292,17 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data,
  */
 
 static int
-p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
+p9_virtio_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
 {
 	int in, out;
 	int n, err, size;
-	struct virtio_chan *chan = t->priv;
+	struct virtio_chan *chan = c->trans;
 	char *rdata;
 	struct p9_req_t *req;
 	unsigned long flags;
 
 	if (*rc == NULL) {
-		*rc = kmalloc(sizeof(struct p9_fcall) + t->msize, GFP_KERNEL);
+		*rc = kmalloc(sizeof(struct p9_fcall) + c->msize, GFP_KERNEL);
 		if (!*rc)
 			return -ENOMEM;
 	}
@@ -325,7 +325,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc tag %d\n", n);
 
 	out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, tc->sdata, tc->size);
-	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, t->msize);
+	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, c->msize);
 
 	req->status = REQ_STATUS_SENT;
 
@@ -341,7 +341,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 
 	size = le32_to_cpu(*(__le32 *) rdata);
 
-	err = p9_deserialize_fcall(rdata, size, *rc, t->extended);
+	err = p9_deserialize_fcall(rdata, size, *rc, c->dotu);
 	if (err < 0) {
 		P9_DPRINTK(P9_DEBUG_TRANS,
 			"9p debug: virtio rpc deserialize returned %d\n", err);
@@ -352,8 +352,8 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 	if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 		char buf[150];
 
-		p9_printfcall(buf, sizeof(buf), *rc, t->extended);
-		printk(KERN_NOTICE ">>> %p %s\n", t, buf);
+		p9_printfcall(buf, sizeof(buf), *rc, c->dotu);
+		printk(KERN_NOTICE ">>> %p %s\n", c, buf);
 	}
 #endif
 
@@ -422,10 +422,9 @@ static int p9_virtio_probe(struct virtio_device *vdev)
 
 /**
  * p9_virtio_create - allocate a new virtio channel
+ * @client: client instance invoking this transport
  * @devname: string identifying the channel to connect to (unused)
  * @args: args passed from sys_mount() for per-transport options (unused)
- * @msize: requested maximum packet size
- * @extended: 9p2000.u enabled flag
  *
  * This sets up a transport channel for 9p communication.  Right now
  * we only match the first available channel, but eventually we couldlook up
@@ -441,11 +440,9 @@ static int p9_virtio_probe(struct virtio_device *vdev)
  *
  */
 
-static struct p9_trans *
-p9_virtio_create(const char *devname, char *args, int msize,
-							unsigned char extended)
+static int
+p9_virtio_create(struct p9_client *client, const char *devname, char *args)
 {
-	struct p9_trans *trans;
 	struct virtio_chan *chan = channels;
 	int index = 0;
 
@@ -463,30 +460,21 @@ p9_virtio_create(const char *devname, char *args, int msize,
 
 	if (index >= MAX_9P_CHAN) {
 		printk(KERN_ERR "9p: no channels available\n");
-		return ERR_PTR(-ENODEV);
+		return -ENODEV;
 	}
 
 	chan->tagpool = p9_idpool_create();
 	if (IS_ERR(chan->tagpool)) {
 		printk(KERN_ERR "9p: couldn't allocate tagpool\n");
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 	}
 	p9_idpool_get(chan->tagpool); /* reserve tag 0 */
 	chan->max_tag = 0;
 	chan->reqs = NULL;
 
-	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
-	if (!trans) {
-		printk(KERN_ERR "9p: couldn't allocate transport\n");
-		return ERR_PTR(-ENOMEM);
-	}
-	trans->extended = extended;
-	trans->msize = msize;
-	trans->close = p9_virtio_close;
-	trans->rpc = p9_virtio_rpc;
-	trans->priv = chan;
+	client->trans = (void *)chan;
 
-	return trans;
+	return 0;
 }
 
 /**
@@ -526,6 +514,8 @@ static struct virtio_driver p9_virtio_drv = {
 static struct p9_trans_module p9_virtio_trans = {
 	.name = "virtio",
 	.create = p9_virtio_create,
+	.close = p9_virtio_close,
+	.rpc = p9_virtio_rpc,
 	.maxsize = PAGE_SIZE*16,
 	.def = 0,
 	.owner = THIS_MODULE,