9p: transport API reorganization

This merges the mux.c (including the connection interface) with trans_fd
in preparation for transport API changes.  Ultimately, trans_fd will need
to be rewritten to clean it up and simplify the implementation, but this
reorganization is viewed as the first step.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

fs/9p/v9fs.c

@@ -3,7 +3,7 @@
  *
  *  This file contains functions assisting in mapping VFS to 9P2000
  *
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -31,7 +31,6 @@
 #include <linux/idr.h>
 #include <net/9p/9p.h>
 #include <net/9p/transport.h>
-#include <net/9p/conn.h>
 #include <net/9p/client.h>
 #include "v9fs.h"
 #include "v9fs_vfs.h"
@@ -43,11 +42,11 @@
 
 enum {
 	/* Options that take integer arguments */
-	Opt_debug, Opt_msize, Opt_dfltuid, Opt_dfltgid, Opt_afid,
+	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
 	/* String options */
 	Opt_uname, Opt_remotename, Opt_trans,
 	/* Options that take no arguments */
-	Opt_legacy, Opt_nodevmap,
+	Opt_nodevmap,
 	/* Cache options */
 	Opt_cache_loose,
 	/* Access options */
@@ -58,14 +57,11 @@ enum {
 
 static match_table_t tokens = {
 	{Opt_debug, "debug=%x"},
-	{Opt_msize, "msize=%u"},
 	{Opt_dfltuid, "dfltuid=%u"},
 	{Opt_dfltgid, "dfltgid=%u"},
 	{Opt_afid, "afid=%u"},
 	{Opt_uname, "uname=%s"},
 	{Opt_remotename, "aname=%s"},
-	{Opt_trans, "trans=%s"},
-	{Opt_legacy, "noextend"},
 	{Opt_nodevmap, "nodevmap"},
 	{Opt_cache_loose, "cache=loose"},
 	{Opt_cache_loose, "loose"},
@@ -85,16 +81,14 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 	char *options;
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
-	int option;
-	int ret;
+	int option = 0;
 	char *s, *e;
+	int ret;
 
 	/* setup defaults */
-	v9ses->maxdata = 8192;
 	v9ses->afid = ~0;
 	v9ses->debug = 0;
 	v9ses->cache = 0;
-	v9ses->trans = v9fs_default_trans();
 
 	if (!v9ses->options)
 		return;
@@ -106,7 +100,8 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 			continue;
 		token = match_token(p, tokens, args);
 		if (token < Opt_uname) {
-			if ((ret = match_int(&args[0], &option)) < 0) {
+			ret = match_int(&args[0], &option);
+			if (ret < 0) {
 				P9_DPRINTK(P9_DEBUG_ERROR,
 					"integer field, but no integer?\n");
 				continue;
@@ -119,9 +114,7 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 			p9_debug_level = option;
 #endif
 			break;
-		case Opt_msize:
-			v9ses->maxdata = option;
-			break;
+
 		case Opt_dfltuid:
 			v9ses->dfltuid = option;
 			break;
@@ -131,18 +124,12 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 		case Opt_afid:
 			v9ses->afid = option;
 			break;
-		case Opt_trans:
-			v9ses->trans = v9fs_match_trans(&args[0]);
-			break;
 		case Opt_uname:
 			match_strcpy(v9ses->uname, &args[0]);
 			break;
 		case Opt_remotename:
 			match_strcpy(v9ses->aname, &args[0]);
 			break;
-		case Opt_legacy:
-			v9ses->flags &= ~V9FS_EXTENDED;
-			break;
 		case Opt_nodevmap:
 			v9ses->nodev = 1;
 			break;
@@ -185,7 +172,6 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		  const char *dev_name, char *data)
 {
 	int retval = -EINVAL;
-	struct p9_trans *trans = NULL;
 	struct p9_fid *fid;
 
 	v9ses->uname = __getname();
@@ -207,24 +193,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	v9ses->options = kstrdup(data, GFP_KERNEL);
 	v9fs_parse_options(v9ses);
 
-	if (v9ses->trans == NULL) {
-		retval = -EPROTONOSUPPORT;
-		P9_DPRINTK(P9_DEBUG_ERROR,
-				"No transport defined or default transport\n");
-		goto error;
-	}
-
-	trans = v9ses->trans->create(dev_name, v9ses->options);
-	if (IS_ERR(trans)) {
-		retval = PTR_ERR(trans);
-		trans = NULL;
-		goto error;
-	}
-	if ((v9ses->maxdata+P9_IOHDRSZ) > v9ses->trans->maxsize)
-		v9ses->maxdata = v9ses->trans->maxsize-P9_IOHDRSZ;
-
-	v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
-		v9fs_extended(v9ses));
+	v9ses->clnt = p9_client_create(dev_name, v9ses->options);
 
 	if (IS_ERR(v9ses->clnt)) {
 		retval = PTR_ERR(v9ses->clnt);
@@ -236,6 +205,8 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	if (!v9ses->clnt->dotu)
 		v9ses->flags &= ~V9FS_EXTENDED;
 
+	v9ses->maxdata = v9ses->clnt->msize;
+
 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
 	if (!v9fs_extended(v9ses) &&
 		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {

fs/9p/v9fs.h

 /*
  * V9FS definitions.
  *
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -28,7 +28,6 @@
 
 struct v9fs_session_info {
 	/* options */
-	unsigned int maxdata;
 	unsigned char flags;	/* session flags */
 	unsigned char nodev;	/* set to 1 if no disable device mapping */
 	unsigned short debug;	/* debug level */
@@ -38,10 +37,10 @@ struct v9fs_session_info {
 	char *options;		/* copy of mount options */
 	char *uname;		/* user name to mount as */
 	char *aname;		/* name of remote hierarchy being mounted */
+	unsigned int maxdata;	/* max data for client interface */
 	unsigned int dfltuid;	/* default uid/muid for legacy support */
 	unsigned int dfltgid;	/* default gid for legacy support */
 	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
-	struct p9_trans_module *trans; /* 9p transport */
 	struct p9_client *clnt;	/* 9p client */
 	struct dentry *debugfs_dir;
 };

include/net/9p/client.h

@@ -3,6 +3,7 @@
  *
  * 9P Client Definitions
  *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -29,6 +30,7 @@ struct p9_client {
 	spinlock_t lock; /* protect client structure */
 	int msize;
 	unsigned char dotu;
+	struct p9_trans_module *trans_mod;
 	struct p9_trans *trans;
 	struct p9_conn *conn;
 
@@ -52,8 +54,7 @@ struct p9_fid {
 	struct list_head dlist;	/* list of all fids attached to a dentry */
 };
 
-struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
-								int dotu);
+struct p9_client *p9_client_create(const char *dev_name, char *options);
 void p9_client_destroy(struct p9_client *clnt);
 void p9_client_disconnect(struct p9_client *clnt);
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,

include/net/9p/conn.h

-/*
- * include/net/9p/conn.h
- *
- * Connection Definitions
- *
- *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2
- *  as published by the Free Software Foundation.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to:
- *  Free Software Foundation
- *  51 Franklin Street, Fifth Floor
- *  Boston, MA  02111-1301  USA
- *
- */
-
-#ifndef NET_9P_CONN_H
-#define NET_9P_CONN_H
-
-#undef P9_NONBLOCK
-
-struct p9_conn;
-struct p9_req;
-
-/**
- * p9_mux_req_callback - callback function that is called when the
- * response of a request is received. The callback is called from
- * a workqueue and shouldn't block.
- *
- * @req - request
- * @a - the pointer that was specified when the request was send to be
- *      passed to the callback
- */
-typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
-
-struct p9_conn *p9_conn_create(struct p9_trans *trans, int msize,
-							unsigned char *dotu);
-void p9_conn_destroy(struct p9_conn *);
-int p9_conn_rpc(struct p9_conn *m, struct p9_fcall *tc, struct p9_fcall **rc);
-
-#ifdef P9_NONBLOCK
-int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
-	p9_conn_req_callback cb, void *a);
-#endif /* P9_NONBLOCK */
-
-void p9_conn_cancel(struct p9_conn *m, int err);
-
-#endif /* NET_9P_CONN_H */

include/net/9p/transport.h

@@ -4,7 +4,7 @@
  * Transport Definition
  *
  *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
@@ -34,13 +34,12 @@ enum p9_trans_status {
 
 struct p9_trans {
 	enum p9_trans_status status;
+	int msize;
+	unsigned char extended;
 	void *priv;
-	int (*write) (struct p9_trans *, void *, int);
-	int (*read) (struct p9_trans *, void *, int);
 	void (*close) (struct p9_trans *);
-	unsigned int (*poll)(struct p9_trans *, struct poll_table_struct *);
 	int (*rpc) (struct p9_trans *t, struct p9_fcall *tc,
-				struct p9_fcall **rc, int msize, int dotu);
+							struct p9_fcall **rc);
 };
 
 struct p9_trans_module {
@@ -48,7 +47,7 @@ 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 *devname, char *options);
+	struct p9_trans * (*create)(const char *, char *, int, unsigned char);
 };
 
 void v9fs_register_trans(struct p9_trans_module *m);

net/9p/Makefile

@@ -4,7 +4,6 @@ obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
 
 9pnet-objs := \
 	mod.o \
-	mux.o \
 	client.o \
 	conv.o \
 	error.o \

net/9p/client.c

@@ -3,6 +3,7 @@
  *
  * 9P Client
  *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -25,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
+#include <linux/poll.h>
 #include <linux/idr.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
@@ -32,13 +34,82 @@
 #include <net/9p/9p.h>
 #include <linux/parser.h>
 #include <net/9p/transport.h>
-#include <net/9p/conn.h>
 #include <net/9p/client.h>
 
 static struct p9_fid *p9_fid_create(struct p9_client *clnt);
 static void p9_fid_destroy(struct p9_fid *fid);
 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu);
 
+/*
+  * Client Option Parsing (code inspired by NFS code)
+  *  - a little lazy - parse all client options
+  */
+
+enum {
+	Opt_msize,
+	Opt_trans,
+	Opt_legacy,
+	Opt_err,
+};
+
+static match_table_t tokens = {
+	{Opt_msize, "msize=%u"},
+	{Opt_legacy, "noextend"},
+	{Opt_trans, "trans=%s"},
+	{Opt_err, NULL},
+};
+
+/**
+ * v9fs_parse_options - parse mount options into session structure
+ * @options: options string passed from mount
+ * @v9ses: existing v9fs session information
+ *
+ */
+
+static void parse_opts(char *options, struct p9_client *clnt)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int option;
+	int ret;
+
+	clnt->trans_mod = v9fs_default_trans();
+	clnt->dotu = 1;
+	clnt->msize = 8192;
+
+	if (!options)
+		return;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+		token = match_token(p, tokens, args);
+		if (token < Opt_trans) {
+			ret = match_int(&args[0], &option);
+			if (ret < 0) {
+				P9_DPRINTK(P9_DEBUG_ERROR,
+					"integer field, but no integer?\n");
+				continue;
+			}
+		}
+		switch (token) {
+		case Opt_msize:
+			clnt->msize = option;
+			break;
+		case Opt_trans:
+			clnt->trans_mod = v9fs_match_trans(&args[0]);
+			break;
+		case Opt_legacy:
+			clnt->dotu = 0;
+			break;
+		default:
+			continue;
+		}
+	}
+}
+
+
 /**
  * p9_client_rpc - sends 9P request and waits until a response is available.
  *      The function can be interrupted.
@@ -50,14 +121,10 @@ int
 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc,
 	struct p9_fcall **rc)
 {
-	if (c->trans->rpc)
-		return c->trans->rpc(c->trans, tc, rc, c->msize, c->dotu);
-	else
-		return p9_conn_rpc(c->conn, tc, rc);
+	return c->trans->rpc(c->trans, tc, rc);
 }
 
-struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
-								   int dotu)
+struct p9_client *p9_client_create(const char *dev_name, char *options)
 {
 	int err, n;
 	struct p9_client *clnt;
@@ -71,12 +138,7 @@ struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
 	if (!clnt)
 		return ERR_PTR(-ENOMEM);
 
-	P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
-		clnt, trans, msize, dotu);
 	spin_lock_init(&clnt->lock);
-	clnt->trans = trans;
-	clnt->msize = msize;
-	clnt->dotu = dotu;
 	INIT_LIST_HEAD(&clnt->fidlist);
 	clnt->fidpool = p9_idpool_create();
 	if (!clnt->fidpool) {
@@ -85,13 +147,29 @@ struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
 		goto error;
 	}
 
-	clnt->conn = p9_conn_create(clnt->trans, clnt->msize, &clnt->dotu);
-	if (IS_ERR(clnt->conn)) {
-		err = PTR_ERR(clnt->conn);
-		clnt->conn = NULL;
+	parse_opts(options, clnt);
+	if (clnt->trans_mod == NULL) {
+		err = -EPROTONOSUPPORT;
+		P9_DPRINTK(P9_DEBUG_ERROR,
+				"No transport defined or default transport\n");
+		goto error;
+	}
+
+	P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
+		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;
 		goto error;
 	}
 
+	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
+		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
+
 	tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
 	if (IS_ERR(tc)) {
 		err = PTR_ERR(tc);
@@ -134,10 +212,6 @@ void p9_client_destroy(struct p9_client *clnt)
 	struct p9_fid *fid, *fidptr;
 
 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
-	if (clnt->conn) {
-		p9_conn_destroy(clnt->conn);
-		clnt->conn = NULL;
-	}
 
 	if (clnt->trans) {
 		clnt->trans->close(clnt->trans);
@@ -159,7 +233,6 @@ void p9_client_disconnect(struct p9_client *clnt)
 {
 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 	clnt->trans->status = Disconnected;
-	p9_conn_cancel(clnt->conn, -EIO);
 }
 EXPORT_SYMBOL(p9_client_disconnect);
 

net/9p/mod.c

@@ -106,15 +106,10 @@ EXPORT_SYMBOL(v9fs_default_trans);
  */
 static int __init init_p9(void)
 {
-	int ret;
+	int ret = 0;
 
 	p9_error_init();
 	printk(KERN_INFO "Installing 9P2000 support\n");
-	ret = p9_mux_global_init();
-	if (ret) {
-		printk(KERN_WARNING "9p: starting mux failed\n");
-		return ret;
-	}
 
 	return ret;
 }
@@ -126,7 +121,7 @@ static int __init init_p9(void)
 
 static void __exit exit_p9(void)
 {
-	p9_mux_global_exit();
+	printk(KERN_INFO "Unloading 9P2000 support\n");
 }
 
 module_init(init_p9)

net/9p/trans_virtio.c

@@ -130,29 +130,6 @@ static unsigned int rest_of_page(void *data)
 	return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE);
 }
 
-static int p9_virtio_write(struct p9_trans *trans, void *buf, int count)
-{
-	/* Only use the rpc mechanism for now */
-	return count;
-}
-
-static int p9_virtio_read(struct p9_trans *trans, void *buf, int count)
-{
-	/* Only use the rpc mechanism for now */
-	return 0;
-}
-
-/* The poll function is used by 9p transports to determine if there
- * is there is activity available on a particular channel.  In our case
- * we use it to wait for a callback from the input routines.
- */
-static unsigned int
-p9_virtio_poll(struct p9_trans *trans, struct poll_table_struct *pt)
-{
-	/* Only use the rpc mechanism for now */
-	return 0;
-}
-
 static void p9_virtio_close(struct p9_trans *trans)
 {
 	struct virtio_chan *chan = trans->priv;
@@ -214,8 +191,7 @@ 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,
-		int msize, int dotu)
+p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 {
 	int in, out;
 	int n, err, size;
@@ -225,7 +201,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc,
 	unsigned long flags;
 
 	if (*rc == NULL) {
-		*rc = kmalloc(sizeof(struct p9_fcall) + msize, GFP_KERNEL);
+		*rc = kmalloc(sizeof(struct p9_fcall) + t->msize, GFP_KERNEL);
 		if (!*rc)
 			return -ENOMEM;
 	}
@@ -248,7 +224,7 @@ 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, msize);
+	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, t->msize);
 
 	req->status = REQ_STATUS_SENT;
 
@@ -264,7 +240,7 @@ 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, dotu);
+	err = p9_deserialize_fcall(rdata, size, *rc, t->extended);
 	if (err < 0) {
 		P9_DPRINTK(P9_DEBUG_TRANS,
 			"9p debug: virtio rpc deserialize returned %d\n", err);
@@ -275,7 +251,7 @@ 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, dotu);
+		p9_printfcall(buf, sizeof(buf), *rc, t->extended);
 		printk(KERN_NOTICE ">>> %p %s\n", t, buf);
 	}
 #endif
@@ -337,7 +313,9 @@ fail:
  * alternate channels by matching devname versus a virtio_config entry.
  * We use a simple reference count mechanism to ensure that only a single
  * mount has a channel open at a time. */
-static struct p9_trans *p9_virtio_create(const char *devname, char *args)
+static struct p9_trans *
+p9_virtio_create(const char *devname, char *args, int msize,
+							unsigned char extended)
 {
 	struct p9_trans *trans;
 	struct virtio_chan *chan = channels;
@@ -374,11 +352,9 @@ static struct p9_trans *p9_virtio_create(const char *devname, char *args)
 		printk(KERN_ERR "9p: couldn't allocate transport\n");
 		return ERR_PTR(-ENOMEM);
 	}
-
-	trans->write = p9_virtio_write;
-	trans->read = p9_virtio_read;
+	trans->extended = extended;
+	trans->msize = msize;
 	trans->close = p9_virtio_close;
-	trans->poll = p9_virtio_poll;
 	trans->rpc = p9_virtio_rpc;
 	trans->priv = chan;