Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: remove sysctl
  9p: fix bad kconfig cross-dependency
  9p: soften invalidation in loose_mode
  9p: attach-per-user
  9p: rename uid and gid parameters
  9p: define session flags
  9p: Make transports dynamic

19 files changed, 689 insertions, 489 deletions

diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index cda6905cbe49..d6fd6c6e4244 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -35,12 +35,12 @@ For remote file server:
 
 For Plan 9 From User Space applications (http://swtch.com/plan9)
 
-	mount -t 9p `namespace`/acme /mnt/9 -o proto=unix,uname=$USER
+	mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
 
 OPTIONS
 =======
 
-  proto=name	select an alternative transport.  Valid options are
+  trans=name	select an alternative transport.  Valid options are
   		currently:
  			unix - specifying a named pipe mount point
  			tcp  - specifying a normal TCP/IP connection
@@ -68,9 +68,9 @@ OPTIONS
 			0x40 = display transport debug
 			0x80 = display allocation debug
 
-  rfdno=n	the file descriptor for reading with proto=fd
+  rfdno=n	the file descriptor for reading with trans=fd
 
-  wfdno=n	the file descriptor for writing with proto=fd
+  wfdno=n	the file descriptor for writing with trans=fd
 
   maxdata=n	the number of bytes to use for 9p packet payload (msize)
 
@@ -78,9 +78,9 @@ OPTIONS
 
   noextend	force legacy mode (no 9p2000.u semantics)
 
-  uid		attempt to mount as a particular uid
+  dfltuid	attempt to mount as a particular uid
 
-  gid		attempt to mount with a particular gid
+  dfltgid	attempt to mount with a particular gid
 
   afid		security channel - used by Plan 9 authentication protocols
 
@@ -88,6 +88,16 @@ OPTIONS
   		This can be used to share devices/named pipes/sockets between
 		hosts.  This functionality will be expanded in later versions.
 
+  access	there are three access modes.
+			user  = if a user tries to access a file on v9fs
+			        filesystem for the first time, v9fs sends an
+			        attach command (Tattach) for that user.
+				This is the default mode.
+			<uid> = allows only user with uid=<uid> to access
+				the files on the mounted filesystem
+			any   = v9fs does single attach and performs all
+				operations as one user
+
 RESOURCES
 =========
 
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index 15e05a15b575..b364da70ff28 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -1,6 +1,7 @@
 /*
  * V9FS FID Management
  *
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
  *  Copyright (C) 2005, 2006 by Eric Van Hensbergen <ericvh@gmail.com>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -34,9 +35,9 @@
 #include "fid.h"
 
 /**
- * v9fs_fid_insert - add a fid to a dentry
+ * v9fs_fid_add - add a fid to a dentry
+ * @dentry: dentry that the fid is being added to
  * @fid: fid to add
- * @dentry: dentry that it is being added to
  *
  */
 
@@ -66,52 +67,144 @@ int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
 }
 
 /**
- * v9fs_fid_lookup - return a locked fid from a dentry
+ * v9fs_fid_find - retrieve a fid that belongs to the specified uid
  * @dentry: dentry to look for fid in
- *
- * find a fid in the dentry, obtain its semaphore and return a reference to it.
- * code calling lookup is responsible for releasing lock
- *
- * TODO: only match fids that have the same uid as current user
+ * @uid: return fid that belongs to the specified user
+ * @any: if non-zero, return any fid associated with the dentry
  *
  */
 
-struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
+static struct p9_fid *v9fs_fid_find(struct dentry *dentry, u32 uid, int any)
 {
 	struct v9fs_dentry *dent;
-	struct p9_fid *fid;
-
-	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
-	dent = dentry->d_fsdata;
-	if (dent)
-		fid = list_entry(dent->fidlist.next, struct p9_fid, dlist);
-	else
-		fid = ERR_PTR(-EBADF);
+	struct p9_fid *fid, *ret;
+
+	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p) uid %d any %d\n",
+		dentry->d_iname, dentry, uid, any);
+	dent = (struct v9fs_dentry *) dentry->d_fsdata;
+	ret = NULL;
+	if (dent) {
+		spin_lock(&dent->lock);
+		list_for_each_entry(fid, &dent->fidlist, dlist) {
+			if (any || fid->uid == uid) {
+				ret = fid;
+				break;
+			}
+		}
+		spin_unlock(&dent->lock);
+	}
 
-	P9_DPRINTK(P9_DEBUG_VFS, " fid: %p\n", fid);
-	return fid;
+	return ret;
 }
 
 /**
- * v9fs_fid_clone - lookup the fid for a dentry, clone a private copy and
- * 	release it
+ * v9fs_fid_lookup - lookup for a fid, try to walk if not found
  * @dentry: dentry to look for fid in
  *
- * find a fid in the dentry and then clone to a new private fid
- *
- * TODO: only match fids that have the same uid as current user
- *
+ * Look for a fid in the specified dentry for the current user.
+ * If no fid is found, try to create one walking from a fid from the parent
+ * dentry (if it has one), or the root dentry. If the user haven't accessed
+ * the fs yet, attach now and walk from the root.
  */
 
-struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
+struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 {
-	struct p9_fid *ofid, *fid;
+	int i, n, l, clone, any, access;
+	u32 uid;
+	struct p9_fid *fid;
+	struct dentry *d, *ds;
+	struct v9fs_session_info *v9ses;
+	char **wnames, *uname;
+
+	v9ses = v9fs_inode2v9ses(dentry->d_inode);
+	access = v9ses->flags & V9FS_ACCESS_MASK;
+	switch (access) {
+	case V9FS_ACCESS_SINGLE:
+	case V9FS_ACCESS_USER:
+		uid = current->fsuid;
+		any = 0;
+		break;
+
+	case V9FS_ACCESS_ANY:
+		uid = v9ses->uid;
+		any = 1;
+		break;
+
+	default:
+		uid = ~0;
+		any = 0;
+		break;
+	}
 
-	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
-	ofid = v9fs_fid_lookup(dentry);
-	if (IS_ERR(ofid))
-		return ofid;
+	fid = v9fs_fid_find(dentry, uid, any);
+	if (fid)
+		return fid;
+
+	ds = dentry->d_parent;
+	fid = v9fs_fid_find(ds, uid, any);
+	if (!fid) { /* walk from the root */
+		n = 0;
+		for (ds = dentry; !IS_ROOT(ds); ds = ds->d_parent)
+			n++;
+
+		fid = v9fs_fid_find(ds, uid, any);
+		if (!fid) { /* the user is not attached to the fs yet */
+			if (access == V9FS_ACCESS_SINGLE)
+				return ERR_PTR(-EPERM);
+
+			if (v9fs_extended(v9ses))
+				uname = NULL;
+			else
+				uname = v9ses->uname;
+
+			fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
+				v9ses->aname);
+
+			if (IS_ERR(fid))
+				return fid;
+
+			v9fs_fid_add(ds, fid);
+		}
+	} else /* walk from the parent */
+		n = 1;
+
+	if (ds == dentry)
+		return fid;
+
+	wnames = kmalloc(sizeof(char *) * n, GFP_KERNEL);
+	if (!wnames)
+		return ERR_PTR(-ENOMEM);
+
+	for (d = dentry, i = n; i >= 0; i--, d = d->d_parent)
+		wnames[i] = (char *) d->d_name.name;
+
+	clone = 1;
+	i = 0;
+	while (i < n) {
+		l = min(n - i, P9_MAXWELEM);
+		fid = p9_client_walk(fid, l, &wnames[i], clone);
+		if (!fid) {
+			kfree(wnames);
+			return fid;
+		}
+
+		i += l;
+		clone = 0;
+	}
 
-	fid = p9_client_walk(ofid, 0, NULL, 1);
+	kfree(wnames);
+	v9fs_fid_add(dentry, fid);
 	return fid;
 }
+
+struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
+{
+	struct p9_fid *fid, *ret;
+
+	fid = v9fs_fid_lookup(dentry);
+	if (IS_ERR(fid))
+		return fid;
+
+	ret = p9_client_walk(fid, 0, NULL, 1);
+	return ret;
+}
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 0a7068e30ecb..873802de21cd 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -38,56 +38,41 @@
 
 /*
   * Option Parsing (code inspired by NFS code)
-  *
+  *  NOTE: each transport will parse its own options
   */
 
 enum {
 	/* Options that take integer arguments */
-	Opt_debug, Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid,
-	Opt_rfdno, Opt_wfdno,
+	Opt_debug, Opt_msize, Opt_dfltuid, Opt_dfltgid, Opt_afid,
 	/* String options */
-	Opt_uname, Opt_remotename,
+	Opt_uname, Opt_remotename, Opt_trans,
 	/* Options that take no arguments */
-	Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd, Opt_pci,
+	Opt_legacy, Opt_nodevmap,
 	/* Cache options */
 	Opt_cache_loose,
+	/* Access options */
+	Opt_access,
 	/* Error token */
 	Opt_err
 };
 
 static match_table_t tokens = {
 	{Opt_debug, "debug=%x"},
-	{Opt_port, "port=%u"},
 	{Opt_msize, "msize=%u"},
-	{Opt_uid, "uid=%u"},
-	{Opt_gid, "gid=%u"},
+	{Opt_dfltuid, "dfltuid=%u"},
+	{Opt_dfltgid, "dfltgid=%u"},
 	{Opt_afid, "afid=%u"},
-	{Opt_rfdno, "rfdno=%u"},
-	{Opt_wfdno, "wfdno=%u"},
 	{Opt_uname, "uname=%s"},
 	{Opt_remotename, "aname=%s"},
-	{Opt_unix, "proto=unix"},
-	{Opt_tcp, "proto=tcp"},
-	{Opt_fd, "proto=fd"},
-#ifdef CONFIG_PCI_9P
-	{Opt_pci, "proto=pci"},
-#endif
-	{Opt_tcp, "tcp"},
-	{Opt_unix, "unix"},
-	{Opt_fd, "fd"},
+	{Opt_trans, "trans=%s"},
 	{Opt_legacy, "noextend"},
 	{Opt_nodevmap, "nodevmap"},
 	{Opt_cache_loose, "cache=loose"},
 	{Opt_cache_loose, "loose"},
+	{Opt_access, "access=%s"},
 	{Opt_err, NULL}
 };
 
-extern struct p9_transport *p9pci_trans_create(void);
-
-/*
- *  Parse option string.
- */
-
 /**
  * v9fs_parse_options - parse mount options into session structure
  * @options: options string passed from mount
@@ -95,23 +80,21 @@ extern struct p9_transport *p9pci_trans_create(void);
  *
  */
 
-static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
+static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 {
-	char *p;
+	char *options = v9ses->options;
 	substring_t args[MAX_OPT_ARGS];
+	char *p;
 	int option;
 	int ret;
+	char *s, *e;
 
 	/* setup defaults */
-	v9ses->port = V9FS_PORT;
-	v9ses->maxdata = 9000;
-	v9ses->proto = PROTO_TCP;
-	v9ses->extended = 1;
+	v9ses->maxdata = 8192;
 	v9ses->afid = ~0;
 	v9ses->debug = 0;
-	v9ses->rfdno = ~0;
-	v9ses->wfdno = ~0;
 	v9ses->cache = 0;
+	v9ses->trans = v9fs_default_trans();
 
 	if (!options)
 		return;
@@ -135,47 +118,29 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
 			p9_debug_level = option;
 #endif
 			break;
-		case Opt_port:
-			v9ses->port = option;
-			break;
 		case Opt_msize:
 			v9ses->maxdata = option;
 			break;
-		case Opt_uid:
-			v9ses->uid = option;
+		case Opt_dfltuid:
+			v9ses->dfltuid = option;
 			break;
-		case Opt_gid:
-			v9ses->gid = option;
+		case Opt_dfltgid:
+			v9ses->dfltgid = option;
 			break;
 		case Opt_afid:
 			v9ses->afid = option;
 			break;
-		case Opt_rfdno:
-			v9ses->rfdno = option;
-			break;
-		case Opt_wfdno:
-			v9ses->wfdno = option;
-			break;
-		case Opt_tcp:
-			v9ses->proto = PROTO_TCP;
-			break;
-		case Opt_unix:
-			v9ses->proto = PROTO_UNIX;
-			break;
-		case Opt_pci:
-			v9ses->proto = PROTO_PCI;
-			break;
-		case Opt_fd:
-			v9ses->proto = PROTO_FD;
+		case Opt_trans:
+			v9ses->trans = v9fs_match_trans(&args[0]);
 			break;
 		case Opt_uname:
-			match_strcpy(v9ses->name, &args[0]);
+			match_strcpy(v9ses->uname, &args[0]);
 			break;
 		case Opt_remotename:
-			match_strcpy(v9ses->remotename, &args[0]);
+			match_strcpy(v9ses->aname, &args[0]);
 			break;
 		case Opt_legacy:
-			v9ses->extended = 0;
+			v9ses->flags &= ~V9FS_EXTENDED;
 			break;
 		case Opt_nodevmap:
 			v9ses->nodev = 1;
@@ -183,6 +148,22 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
 		case Opt_cache_loose:
 			v9ses->cache = CACHE_LOOSE;
 			break;
+
+		case Opt_access:
+			s = match_strdup(&args[0]);
+			v9ses->flags &= ~V9FS_ACCESS_MASK;
+			if (strcmp(s, "user") == 0)
+				v9ses->flags |= V9FS_ACCESS_USER;
+			else if (strcmp(s, "any") == 0)
+				v9ses->flags |= V9FS_ACCESS_ANY;
+			else {
+				v9ses->flags |= V9FS_ACCESS_SINGLE;
+				v9ses->uid = simple_strtol(s, &e, 10);
+				if (*e != '\0')
+					v9ses->uid = ~0;
+			}
+			break;
+
 		default:
 			continue;
 		}
@@ -201,56 +182,46 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		  const char *dev_name, char *data)
 {
 	int retval = -EINVAL;
-	struct p9_transport *trans;
+	struct p9_trans *trans = NULL;
 	struct p9_fid *fid;
 
-	v9ses->name = __getname();
-	if (!v9ses->name)
+	v9ses->uname = __getname();
+	if (!v9ses->uname)
 		return ERR_PTR(-ENOMEM);
 
-	v9ses->remotename = __getname();
-	if (!v9ses->remotename) {
-		__putname(v9ses->name);
+	v9ses->aname = __getname();
+	if (!v9ses->aname) {
+		__putname(v9ses->uname);
 		return ERR_PTR(-ENOMEM);
 	}
 
-	strcpy(v9ses->name, V9FS_DEFUSER);
-	strcpy(v9ses->remotename, V9FS_DEFANAME);
-
-	v9fs_parse_options(data, v9ses);
-
-	switch (v9ses->proto) {
-	case PROTO_TCP:
-		trans = p9_trans_create_tcp(dev_name, v9ses->port);
-		break;
-	case PROTO_UNIX:
-		trans = p9_trans_create_unix(dev_name);
-		*v9ses->remotename = 0;
-		break;
-	case PROTO_FD:
-		trans = p9_trans_create_fd(v9ses->rfdno, v9ses->wfdno);
-		*v9ses->remotename = 0;
-		break;
-#ifdef CONFIG_PCI_9P
-	case PROTO_PCI:
-		trans = p9pci_trans_create();
-		*v9ses->remotename = 0;
-		break;
-#endif
-	default:
-		printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
-		retval = -ENOPROTOOPT;
+	v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
+	strcpy(v9ses->uname, V9FS_DEFUSER);
+	strcpy(v9ses->aname, V9FS_DEFANAME);
+	v9ses->uid = ~0;
+	v9ses->dfltuid = V9FS_DEFUID;
+	v9ses->dfltgid = V9FS_DEFGID;
+	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,
-		v9ses->extended);
+	v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
+		v9fs_extended(v9ses));
 
 	if (IS_ERR(v9ses->clnt)) {
 		retval = PTR_ERR(v9ses->clnt);
@@ -259,8 +230,20 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		goto error;
 	}
 
-	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->name,
-							v9ses->remotename);
+	if (!v9ses->clnt->dotu)
+		v9ses->flags &= ~V9FS_EXTENDED;
+
+	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
+	if (!v9fs_extended(v9ses) &&
+		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
+
+		v9ses->flags &= ~V9FS_ACCESS_MASK;
+		v9ses->flags |= V9FS_ACCESS_ANY;
+		v9ses->uid = ~0;
+	}
+
+	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
+							v9ses->aname);
 	if (IS_ERR(fid)) {
 		retval = PTR_ERR(fid);
 		fid = NULL;
@@ -268,6 +251,11 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		goto error;
 	}
 
+	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
+		fid->uid = v9ses->uid;
+	else
+		fid->uid = ~0;
+
 	return fid;
 
 error:
@@ -288,8 +276,9 @@ void v9fs_session_close(struct v9fs_session_info *v9ses)
 		v9ses->clnt = NULL;
 	}
 
-	__putname(v9ses->name);
-	__putname(v9ses->remotename);
+	__putname(v9ses->uname);
+	__putname(v9ses->aname);
+	kfree(v9ses->options);
 }
 
 /**
@@ -311,7 +300,7 @@ extern int v9fs_error_init(void);
 static int __init init_v9fs(void)
 {
 	printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
-
+	/* TODO: Setup list of registered trasnport modules */
 	return register_filesystem(&v9fs_fs_type);
 }
 
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index abc4b1668ace..db4b4193f2e2 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -29,31 +29,30 @@
 struct v9fs_session_info {
 	/* options */
 	unsigned int maxdata;
-	unsigned char extended;	/* set to 1 if we are using UNIX extensions */
+	unsigned char flags;	/* session flags */
 	unsigned char nodev;	/* set to 1 if no disable device mapping */
-	unsigned short port;	/* port to connect to */
 	unsigned short debug;	/* debug level */
-	unsigned short proto;	/* protocol to use */
 	unsigned int afid;	/* authentication fid */
-	unsigned int rfdno;	/* read file descriptor number */
-	unsigned int wfdno;	/* write file descriptor number */
 	unsigned int cache;	/* cache mode */
 
-	char *name;		/* user name to mount as */
-	char *remotename;	/* name of remote hierarchy being mounted */
-	unsigned int uid;	/* default uid/muid for legacy support */
-	unsigned int gid;	/* default gid for legacy support */
-
+	char *options;		/* copy of mount options */
+	char *uname;		/* user name to mount as */
+	char *aname;		/* name of remote hierarchy being mounted */
+	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;
 };
 
-/* possible values of ->proto */
+/* session flags */
 enum {
-	PROTO_TCP,
-	PROTO_UNIX,
-	PROTO_FD,
-	PROTO_PCI,
+	V9FS_EXTENDED		= 0x01,	/* 9P2000.u */
+	V9FS_ACCESS_MASK	= 0x06,	/* access mask */
+	V9FS_ACCESS_SINGLE	= 0x02,	/* only one user can access the files */
+	V9FS_ACCESS_USER	= 0x04,	/* attache per user */
+	V9FS_ACCESS_ANY		= 0x06,	/* use the same attach for all users */
 };
 
 /* possible values of ->cache */
@@ -73,11 +72,18 @@ void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 #define V9FS_MAGIC 0x01021997
 
 /* other default globals */
-#define V9FS_PORT		564
+#define V9FS_PORT	564
 #define V9FS_DEFUSER	"nobody"
 #define V9FS_DEFANAME	""
+#define V9FS_DEFUID	(-2)
+#define V9FS_DEFGID	(-2)
 
 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 {
 	return (inode->i_sb->s_fs_info);
 }
+
+static inline int v9fs_extended(struct v9fs_session_info *v9ses)
+{
+	return v9ses->flags & V9FS_EXTENDED;
+}
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 716691689fd5..ba4b1caa9c43 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -162,15 +162,17 @@ v9fs_file_write(struct file *filp, const char __user * data,
 
 	fid = filp->private_data;
 	ret = p9_client_uwrite(fid, data, *offset, count);
-	if (ret > 0)
+	if (ret > 0) {
+		invalidate_inode_pages2_range(inode->i_mapping, *offset,
+								*offset+ret);
 		*offset += ret;
+	}
 
 	if (*offset > inode->i_size) {
 		inode->i_size = *offset;
 		inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
 	}
 
-	invalidate_inode_pages2(inode->i_mapping);
 	return ret;
 }
 
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index e5c45eed58a9..175b4d9bf3f8 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -59,7 +59,7 @@ static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
 	res = mode & 0777;
 	if (S_ISDIR(mode))
 		res |= P9_DMDIR;
-	if (v9ses->extended) {
+	if (v9fs_extended(v9ses)) {
 		if (S_ISLNK(mode))
 			res |= P9_DMSYMLINK;
 		if (v9ses->nodev == 0) {
@@ -99,21 +99,21 @@ static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
 
 	if ((mode & P9_DMDIR) == P9_DMDIR)
 		res |= S_IFDIR;
-	else if ((mode & P9_DMSYMLINK) && (v9ses->extended))
+	else if ((mode & P9_DMSYMLINK) && (v9fs_extended(v9ses)))
 		res |= S_IFLNK;
-	else if ((mode & P9_DMSOCKET) && (v9ses->extended)
+	else if ((mode & P9_DMSOCKET) && (v9fs_extended(v9ses))
 		 && (v9ses->nodev == 0))
 		res |= S_IFSOCK;
-	else if ((mode & P9_DMNAMEDPIPE) && (v9ses->extended)
+	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_extended(v9ses))
 		 && (v9ses->nodev == 0))
 		res |= S_IFIFO;
-	else if ((mode & P9_DMDEVICE) && (v9ses->extended)
+	else if ((mode & P9_DMDEVICE) && (v9fs_extended(v9ses))
 		 && (v9ses->nodev == 0))
 		res |= S_IFBLK;
 	else
 		res |= S_IFREG;
 
-	if (v9ses->extended) {
+	if (v9fs_extended(v9ses)) {
 		if ((mode & P9_DMSETUID) == P9_DMSETUID)
 			res |= S_ISUID;
 
@@ -214,7 +214,7 @@ struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 		case S_IFBLK:
 		case S_IFCHR:
 		case S_IFSOCK:
-			if(!v9ses->extended) {
+			if (!v9fs_extended(v9ses)) {
 				P9_DPRINTK(P9_DEBUG_ERROR,
 				      "special files without extended mode\n");
 				return ERR_PTR(-EINVAL);
@@ -227,7 +227,7 @@ struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 			inode->i_fop = &v9fs_file_operations;
 			break;
 		case S_IFLNK:
-			if(!v9ses->extended) {
+			if (!v9fs_extended(v9ses)) {
 				P9_DPRINTK(P9_DEBUG_ERROR,
 					"extended modes used w/o 9P2000.u\n");
 				return ERR_PTR(-EINVAL);
@@ -236,7 +236,7 @@ struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 			break;
 		case S_IFDIR:
 			inc_nlink(inode);
-			if(v9ses->extended)
+			if (v9fs_extended(v9ses))
 				inode->i_op = &v9fs_dir_inode_operations_ext;
 			else
 				inode->i_op = &v9fs_dir_inode_operations;
@@ -364,7 +364,7 @@ static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 	file_inode = file->d_inode;
 	v9ses = v9fs_inode2v9ses(file_inode);
 	v9fid = v9fs_fid_clone(file);
-	if(IS_ERR(v9fid))
+	if (IS_ERR(v9fid))
 		return PTR_ERR(v9fid);
 
 	return p9_client_remove(v9fid);
@@ -398,7 +398,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	fid = NULL;
 	name = (char *) dentry->d_name.name;
 	dfid = v9fs_fid_clone(dentry->d_parent);
-	if(IS_ERR(dfid)) {
+	if (IS_ERR(dfid)) {
 		err = PTR_ERR(dfid);
 		dfid = NULL;
 		goto error;
@@ -432,7 +432,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 		goto error;
 	}
 
-	if(v9ses->cache)
+	if (v9ses->cache)
 		dentry->d_op = &v9fs_cached_dentry_operations;
 	else
 		dentry->d_op = &v9fs_dentry_operations;
@@ -593,7 +593,7 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 	if (result < 0)
 		goto error;
 
-	if((fid->qid.version)&&(v9ses->cache))
+	if ((fid->qid.version) && (v9ses->cache))
 		dentry->d_op = &v9fs_cached_dentry_operations;
 	else
 		dentry->d_op = &v9fs_dentry_operations;
@@ -658,17 +658,17 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	old_inode = old_dentry->d_inode;
 	v9ses = v9fs_inode2v9ses(old_inode);
 	oldfid = v9fs_fid_lookup(old_dentry);
-	if(IS_ERR(oldfid))
+	if (IS_ERR(oldfid))
 		return PTR_ERR(oldfid);
 
 	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
-	if(IS_ERR(olddirfid)) {
+	if (IS_ERR(olddirfid)) {
 		retval = PTR_ERR(olddirfid);
 		goto done;
 	}
 
 	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
-	if(IS_ERR(newdirfid)) {
+	if (IS_ERR(newdirfid)) {
 		retval = PTR_ERR(newdirfid);
 		goto clunk_olddir;
 	}
@@ -682,7 +682,7 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	}
 
 	v9fs_blank_wstat(&wstat);
-	wstat.muid = v9ses->name;
+	wstat.muid = v9ses->uname;
 	wstat.name = (char *) new_dentry->d_name.name;
 	retval = p9_client_wstat(oldfid, &wstat);
 
@@ -768,7 +768,7 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 	if (iattr->ia_valid & ATTR_SIZE)
 		wstat.length = iattr->ia_size;
 
-	if (v9ses->extended) {
+	if (v9fs_extended(v9ses)) {
 		if (iattr->ia_valid & ATTR_UID)
 			wstat.n_uid = iattr->ia_uid;
 
@@ -805,10 +805,10 @@ v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
 	inode->i_mtime.tv_sec = stat->mtime;
 	inode->i_ctime.tv_sec = stat->mtime;
 
-	inode->i_uid = v9ses->uid;
-	inode->i_gid = v9ses->gid;
+	inode->i_uid = v9ses->dfltuid;
+	inode->i_gid = v9ses->dfltgid;
 
-	if (v9ses->extended) {
+	if (v9fs_extended(v9ses)) {
 		inode->i_uid = stat->n_uid;
 		inode->i_gid = stat->n_gid;
 	}
@@ -887,10 +887,10 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 	retval = -EPERM;
 	v9ses = v9fs_inode2v9ses(dentry->d_inode);
 	fid = v9fs_fid_lookup(dentry);
-	if(IS_ERR(fid))
+	if (IS_ERR(fid))
 		return PTR_ERR(fid);
 
-	if (!v9ses->extended)
+	if (!v9fs_extended(v9ses))
 		return -EBADF;
 
 	st = p9_client_stat(fid);
@@ -1011,7 +1011,7 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
 	struct p9_fid *fid;
 
 	v9ses = v9fs_inode2v9ses(dir);
-	if (!v9ses->extended) {
+	if (!v9fs_extended(v9ses)) {
 		P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
 		return -EPERM;
 	}
@@ -1070,7 +1070,7 @@ v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
 		old_dentry->d_name.name);
 
 	oldfid = v9fs_fid_clone(old_dentry);
-	if(IS_ERR(oldfid))
+	if (IS_ERR(oldfid))
 		return PTR_ERR(oldfid);
 
 	name = __getname();
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index ba904371218b..bb0cef9a6b8a 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -216,24 +216,7 @@ static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
 {
 	struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
 
-	if (v9ses->debug != 0)
-		seq_printf(m, ",debug=%x", v9ses->debug);
-	if (v9ses->port != V9FS_PORT)
-		seq_printf(m, ",port=%u", v9ses->port);
-	if (v9ses->maxdata != 9000)
-		seq_printf(m, ",msize=%u", v9ses->maxdata);
-	if (v9ses->afid != ~0)
-		seq_printf(m, ",afid=%u", v9ses->afid);
-	if (v9ses->proto == PROTO_UNIX)
-		seq_puts(m, ",proto=unix");
-	if (v9ses->extended == 0)
-		seq_puts(m, ",noextend");
-	if (v9ses->nodev == 1)
-		seq_puts(m, ",nodevmap");
-	seq_printf(m, ",name=%s", v9ses->name);
-	seq_printf(m, ",aname=%s", v9ses->remotename);
-	seq_printf(m, ",uid=%u", v9ses->uid);
-	seq_printf(m, ",gid=%u", v9ses->gid);
+	seq_printf(m, "%s", v9ses->options);
 	return 0;
 }
 
diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 7726ff41c3e6..686425a97b0f 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -216,6 +216,7 @@ struct p9_tauth {
 	u32 afid;
 	struct p9_str uname;
 	struct p9_str aname;
+	u32 n_uname;		/* 9P2000.u extensions */
 };
 
 struct p9_rauth {
@@ -239,6 +240,7 @@ struct p9_tattach {
 	u32 afid;
 	struct p9_str uname;
 	struct p9_str aname;
+	u32 n_uname;		/* 9P2000.u extensions */
 };
 
 struct p9_rattach {
@@ -382,8 +384,9 @@ int p9_deserialize_fcall(void *buf, u32 buflen, struct p9_fcall *fc, int dotu);
 void p9_set_tag(struct p9_fcall *fc, u16 tag);
 struct p9_fcall *p9_create_tversion(u32 msize, char *version);
 struct p9_fcall *p9_create_tattach(u32 fid, u32 afid, char *uname,
-	char *aname);
-struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname);
+	char *aname, u32 n_uname, int dotu);
+struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname,
+	u32 n_uname, int dotu);
 struct p9_fcall *p9_create_tflush(u16 oldtag);
 struct p9_fcall *p9_create_twalk(u32 fid, u32 newfid, u16 nwname,
 	char **wnames);
@@ -412,18 +415,4 @@ int p9_idpool_check(int id, struct p9_idpool *p);
 
 int p9_error_init(void);
 int p9_errstr2errno(char *, int);
-
-#ifdef CONFIG_SYSCTL
-int __init p9_sysctl_register(void);
-void __exit p9_sysctl_unregister(void);
-#else
-static inline int p9_sysctl_register(void)
-{
-	return 0;
-}
-static inline void p9_sysctl_unregister(void)
-{
-}
-#endif
-
 #endif /* NET_9P_H */
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index d65ed7c69063..9b9221a21392 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -29,7 +29,7 @@ struct p9_client {
 	spinlock_t lock; /* protect client structure */
 	int msize;
 	unsigned char dotu;
-	struct p9_transport *trans;
+	struct p9_trans *trans;
 	struct p9_conn *conn;
 
 	struct p9_idpool *fidpool;
@@ -52,13 +52,14 @@ struct p9_fid {
 	struct list_head dlist;	/* list of all fids attached to a dentry */
 };
 
-struct p9_client *p9_client_create(struct p9_transport *trans, int msize,
+struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
 								int dotu);
 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,
-						     char *uname, char *aname);
-struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname, char *aname);
+					char *uname, u32 n_uname, char *aname);
+struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
+						u32 n_uname, char *aname);
 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 								int clone);
 int p9_client_open(struct p9_fid *fid, int mode);
diff --git a/include/net/9p/conn.h b/include/net/9p/conn.h
index 583b6a2cb3df..756d8784f953 100644
--- a/include/net/9p/conn.h
+++ b/include/net/9p/conn.h
@@ -42,8 +42,8 @@ struct p9_req;
  */
 typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
 
-struct p9_conn *p9_conn_create(struct p9_transport *trans, int msize,
-	unsigned char *dotu);
+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);
 
diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
index 462d42279fb0..9dd4a05619a8 100644
--- a/include/net/9p/transport.h
+++ b/include/net/9p/transport.h
@@ -26,24 +26,31 @@
 #ifndef NET_9P_TRANSPORT_H
 #define NET_9P_TRANSPORT_H
 
-enum p9_transport_status {
+enum p9_trans_status {
 	Connected,
 	Disconnected,
 	Hung,
 };
 
-struct p9_transport {
-	enum p9_transport_status status;
+struct p9_trans {
+	enum p9_trans_status status;
 	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 (*write) (struct p9_transport *, void *, int);
-	int (*read) (struct p9_transport *, void *, int);
-	void (*close) (struct p9_transport *);
-	unsigned int (*poll)(struct p9_transport *, struct poll_table_struct *);
+struct p9_trans_module {
+	struct list_head list;
+	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_transport *p9_trans_create_tcp(const char *addr, int port);
-struct p9_transport *p9_trans_create_unix(const char *addr);
-struct p9_transport *p9_trans_create_fd(int rfd, int wfd);
+void v9fs_register_trans(struct p9_trans_module *m);
+struct p9_trans_module *v9fs_match_trans(const substring_t *name);
+struct p9_trans_module *v9fs_default_trans(void);
 
 #endif /* NET_9P_TRANSPORT_H */
diff --git a/net/9p/Kconfig b/net/9p/Kconfig
index 66821cd64a76..eecbf12f6393 100644
--- a/net/9p/Kconfig
+++ b/net/9p/Kconfig
@@ -13,6 +13,16 @@ menuconfig NET_9P
 
 	  If unsure, say N.
 
+config NET_9P_FD
+	depends on NET_9P
+	default y if NET_9P
+	tristate "9P File Descriptor Transports (Experimental)"
+	help
+	  This builds support for file descriptor transports for 9p
+	  which includes support for TCP/IP, named pipes, or passed
+	  file descriptors.  TCP/IP is the default transport for 9p,
+	  so if you are going to use 9p, you'll likely want this.
+
 config NET_9P_DEBUG
 	bool "Debug information"
 	depends on NET_9P
diff --git a/net/9p/Makefile b/net/9p/Makefile
index 85b3a7838acf..5059bc06f8f3 100644
--- a/net/9p/Makefile
+++ b/net/9p/Makefile
@@ -1,8 +1,8 @@
 obj-$(CONFIG_NET_9P) := 9pnet.o
+obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
 
 9pnet-objs := \
 	mod.o \
-	trans_fd.o \
 	mux.o \
 	client.o \
 	conv.o \
@@ -10,4 +10,5 @@ obj-$(CONFIG_NET_9P) := 9pnet.o
 	fcprint.o \
 	util.o \
 
-9pnet-$(CONFIG_SYSCTL) += sysctl.o
+9pnet_fd-objs := \
+	trans_fd.o \
diff --git a/net/9p/client.c b/net/9p/client.c
index cb170750337c..af9199364049 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -30,6 +30,7 @@
 #include <linux/sched.h>
 #include <linux/uaccess.h>
 #include <net/9p/9p.h>
+#include <linux/parser.h>
 #include <net/9p/transport.h>
 #include <net/9p/conn.h>
 #include <net/9p/client.h>
@@ -38,7 +39,7 @@ 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);
 
-struct p9_client *p9_client_create(struct p9_transport *trans, int msize,
+struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
 								   int dotu)
 {
 	int err, n;
@@ -146,7 +147,7 @@ void p9_client_disconnect(struct p9_client *clnt)
 EXPORT_SYMBOL(p9_client_disconnect);
 
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
-	char *uname, char *aname)
+	char *uname, u32 n_uname, char *aname)
 {
 	int err;
 	struct p9_fcall *tc, *rc;
@@ -165,7 +166,8 @@ struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 		goto error;
 	}
 
-	tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname);
+	tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
+		n_uname, clnt->dotu);
 	if (IS_ERR(tc)) {
 		err = PTR_ERR(tc);
 		tc = NULL;
@@ -190,7 +192,8 @@ error:
 }
 EXPORT_SYMBOL(p9_client_attach);
 
-struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname, char *aname)
+struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
+	u32 n_uname, char *aname)
 {
 	int err;
 	struct p9_fcall *tc, *rc;
@@ -209,7 +212,7 @@ struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname, char *aname)
 		goto error;
 	}
 
-	tc = p9_create_tauth(fid->fid, uname, aname);
+	tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
 	if (IS_ERR(tc)) {
 		err = PTR_ERR(tc);
 		tc = NULL;
diff --git a/net/9p/conv.c b/net/9p/conv.c
index d979d958ea19..aa2aa9884f95 100644
--- a/net/9p/conv.c
+++ b/net/9p/conv.c
@@ -547,7 +547,8 @@ error:
 }
 EXPORT_SYMBOL(p9_create_tversion);
 
-struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname)
+struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname,
+	u32 n_uname, int dotu)
 {
 	int size;
 	struct p9_fcall *fc;
@@ -555,7 +556,16 @@ struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname)
 	struct cbuf *bufp = &buffer;
 
 	/* afid[4] uname[s] aname[s] */
-	size = 4 + 2 + strlen(uname) + 2 + strlen(aname);
+	size = 4 + 2 + 2;
+	if (uname)
+		size += strlen(uname);
+
+	if (aname)
+		size += strlen(aname);
+
+	if (dotu)
+		size += 4;	/* n_uname */
+
 	fc = p9_create_common(bufp, size, P9_TAUTH);
 	if (IS_ERR(fc))
 		goto error;
@@ -563,6 +573,8 @@ struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname)
 	p9_put_int32(bufp, afid, &fc->params.tauth.afid);
 	p9_put_str(bufp, uname, &fc->params.tauth.uname);
 	p9_put_str(bufp, aname, &fc->params.tauth.aname);
+	if (dotu)
+		p9_put_int32(bufp, n_uname, &fc->params.tauth.n_uname);
 
 	if (buf_check_overflow(bufp)) {
 		kfree(fc);
@@ -574,7 +586,8 @@ error:
 EXPORT_SYMBOL(p9_create_tauth);
 
 struct p9_fcall *
-p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname)
+p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname,
+	u32 n_uname, int dotu)
 {
 	int size;
 	struct p9_fcall *fc;
@@ -582,7 +595,16 @@ p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname)
 	struct cbuf *bufp = &buffer;
 
 	/* fid[4] afid[4] uname[s] aname[s] */
-	size = 4 + 4 + 2 + strlen(uname) + 2 + strlen(aname);
+	size = 4 + 4 + 2 + 2;
+	if (uname)
+		size += strlen(uname);
+
+	if (aname)
+		size += strlen(aname);
+
+	if (dotu)
+		size += 4;	/* n_uname */
+
 	fc = p9_create_common(bufp, size, P9_TATTACH);
 	if (IS_ERR(fc))
 		goto error;
@@ -591,6 +613,8 @@ p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname)
 	p9_put_int32(bufp, afid, &fc->params.tattach.afid);
 	p9_put_str(bufp, uname, &fc->params.tattach.uname);
 	p9_put_str(bufp, aname, &fc->params.tattach.aname);
+	if (dotu)
+		p9_put_int32(bufp, n_uname, &fc->params.tattach.n_uname);
 
 error:
 	return fc;
diff --git a/net/9p/mod.c b/net/9p/mod.c
index 4f9e1d2ac257..41d70f47375d 100644
--- a/net/9p/mod.c
+++ b/net/9p/mod.c
@@ -27,6 +27,10 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <net/9p/9p.h>
+#include <linux/fs.h>
+#include <linux/parser.h>
+#include <net/9p/transport.h>
+#include <linux/list.h>
 
 #ifdef CONFIG_NET_9P_DEBUG
 unsigned int p9_debug_level = 0;	/* feature-rific global debug level  */
@@ -37,8 +41,64 @@ MODULE_PARM_DESC(debug, "9P debugging level");
 
 extern int p9_mux_global_init(void);
 extern void p9_mux_global_exit(void);
-extern int p9_sysctl_register(void);
-extern void p9_sysctl_unregister(void);
+
+/*
+ * Dynamic Transport Registration Routines
+ *
+ */
+
+static LIST_HEAD(v9fs_trans_list);
+static struct p9_trans_module *v9fs_default_transport;
+
+/**
+ * v9fs_register_trans - register a new transport with 9p
+ * @m - structure describing the transport module and entry points
+ *
+ */
+void v9fs_register_trans(struct p9_trans_module *m)
+{
+	list_add_tail(&m->list, &v9fs_trans_list);
+	if (m->def)
+		v9fs_default_transport = m;
+}
+EXPORT_SYMBOL(v9fs_register_trans);
+
+/**
+ * v9fs_match_trans - match transport versus registered transports
+ * @arg: string identifying transport
+ *
+ */
+struct p9_trans_module *v9fs_match_trans(const substring_t *name)
+{
+	struct list_head *p;
+	struct p9_trans_module *t = NULL;
+
+	list_for_each(p, &v9fs_trans_list) {
+		t = list_entry(p, struct p9_trans_module, list);
+		if (strncmp(t->name, name->from, name->to-name->from) == 0)
+			break;
+	}
+	return t;
+}
+EXPORT_SYMBOL(v9fs_match_trans);
+
+/**
+ * v9fs_default_trans - returns pointer to default transport
+ *
+ */
+
+struct p9_trans_module *v9fs_default_trans(void)
+{
+	if (v9fs_default_transport)
+		return v9fs_default_transport;
+	else if (!list_empty(&v9fs_trans_list))
+		return list_first_entry(&v9fs_trans_list,
+					struct p9_trans_module, list);
+	else
+		return NULL;
+}
+EXPORT_SYMBOL(v9fs_default_trans);
+
 
 /**
  * v9fs_init - Initialize module
@@ -56,12 +116,6 @@ static int __init init_p9(void)
 		return ret;
 	}
 
-	ret = p9_sysctl_register();
-	if (ret) {
-		printk(KERN_WARNING "9p: registering sysctl failed\n");
-		return ret;
-	}
-
 	return ret;
 }
 
@@ -72,7 +126,6 @@ static int __init init_p9(void)
 
 static void __exit exit_p9(void)
 {
-	p9_sysctl_unregister();
 	p9_mux_global_exit();
 }
 
diff --git a/net/9p/mux.c b/net/9p/mux.c
index 5d70558c4c61..f14014793bed 100644
--- a/net/9p/mux.c
+++ b/net/9p/mux.c
@@ -31,6 +31,7 @@
 #include <linux/idr.h>
 #include <linux/mutex.h>
 #include <net/9p/9p.h>
+#include <linux/parser.h>
 #include <net/9p/transport.h>
 #include <net/9p/conn.h>
 
@@ -71,7 +72,7 @@ struct p9_conn {
 	struct p9_mux_poll_task *poll_task;
 	int msize;
 	unsigned char *extended;
-	struct p9_transport *trans;
+	struct p9_trans *trans;
 	struct p9_idpool *tagpool;
 	int err;
 	wait_queue_head_t equeue;
@@ -271,7 +272,7 @@ static void p9_mux_poll_stop(struct p9_conn *m)
  * @msize - maximum message size
  * @extended - pointer to the extended flag
  */
-struct p9_conn *p9_conn_create(struct p9_transport *trans, int msize,
+struct p9_conn *p9_conn_create(struct p9_trans *trans, int msize,
 				    unsigned char *extended)
 {
 	int i, n;
diff --git a/net/9p/sysctl.c b/net/9p/sysctl.c
deleted file mode 100644
index 8b61027a24ea..000000000000
--- a/net/9p/sysctl.c
+++ /dev/null
@@ -1,81 +0,0 @@
-/*
- *  net/9p/sysctl.c
- *
- *  9P sysctl interface
- *
- *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
- *
- *  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
- *
- */
-
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/sysctl.h>
-#include <linux/init.h>
-#include <net/9p/9p.h>
-
-static struct ctl_table p9_table[] = {
-#ifdef CONFIG_NET_9P_DEBUG
-	{
-		.ctl_name       = CTL_UNNUMBERED,
-		.procname       = "debug",
-		.data           = &p9_debug_level,
-		.maxlen         = sizeof(int),
-		.mode           = 0644,
-		.proc_handler   = &proc_dointvec
-	},
-#endif
-	{},
-};
-
-static struct ctl_table p9_net_table[] = {
-	{
-		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "9p",
-		.maxlen		= 0,
-		.mode		= 0555,
-		.child		= p9_table,
-	},
-	{},
-};
-
-static struct ctl_table p9_ctl_table[] = {
-	{
-		.ctl_name	= CTL_NET,
-		.procname	= "net",
-		.maxlen		= 0,
-		.mode		= 0555,
-		.child		= p9_net_table,
-	},
-	{},
-};
-
-static struct ctl_table_header *p9_table_header;
-
-int __init p9_sysctl_register(void)
-{
-	p9_table_header = register_sysctl_table(p9_ctl_table);
-	if (!p9_table_header)
-		return -ENOMEM;
-
-	return 0;
-}
-
-void __exit p9_sysctl_unregister(void)
-{
-	 unregister_sysctl_table(p9_table_header);
-}
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index fd636e94358f..30269a4ff22a 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -5,7 +5,7 @@
  *
  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
- *  Copyright (C) 2004-2005 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2007 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -36,160 +36,114 @@
 #include <linux/inet.h>
 #include <linux/idr.h>
 #include <linux/file.h>
+#include <linux/parser.h>
 #include <net/9p/9p.h>
 #include <net/9p/transport.h>
 
 #define P9_PORT 564
+#define MAX_SOCK_BUF (64*1024)
+
+
+struct p9_fd_opts {
+	int rfd;
+	int wfd;
+	u16 port;
+};
 
 struct p9_trans_fd {
 	struct file *rd;
 	struct file *wr;
 };
 
-static int p9_socket_open(struct p9_transport *trans, struct socket *csocket);
-static int p9_fd_open(struct p9_transport *trans, int rfd, int wfd);
-static int p9_fd_read(struct p9_transport *trans, void *v, int len);
-static int p9_fd_write(struct p9_transport *trans, void *v, int len);
-static unsigned int p9_fd_poll(struct p9_transport *trans,
-						struct poll_table_struct *pt);
-static void p9_fd_close(struct p9_transport *trans);
-
-struct p9_transport *p9_trans_create_tcp(const char *addr, int port)
-{
-	int err;
-	struct p9_transport *trans;
-	struct socket *csocket;
-	struct sockaddr_in sin_server;
-
-	csocket = NULL;
-	trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
-	if (!trans)
-		return ERR_PTR(-ENOMEM);
-
-	trans->write = p9_fd_write;
-	trans->read = p9_fd_read;
-	trans->close = p9_fd_close;
-	trans->poll = p9_fd_poll;
-
-	sin_server.sin_family = AF_INET;
-	sin_server.sin_addr.s_addr = in_aton(addr);
-	sin_server.sin_port = htons(port);
-	sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
-
-	if (!csocket) {
-		P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
-		err = -EIO;
-		goto error;
-	}
-
-	err = csocket->ops->connect(csocket,
-				    (struct sockaddr *)&sin_server,
-				    sizeof(struct sockaddr_in), 0);
-	if (err < 0) {
-		P9_EPRINTK(KERN_ERR,
-			"p9_trans_tcp: problem connecting socket to %s\n",
-			addr);
-		goto error;
-	}
-
-	err = p9_socket_open(trans, csocket);
-	if (err < 0)
-		goto error;
+/*
+  * Option Parsing (code inspired by NFS code)
+  *  - a little lazy - parse all fd-transport options
+  */
 
-	return trans;
+enum {
+	/* Options that take integer arguments */
+	Opt_port, Opt_rfdno, Opt_wfdno,
+};
 
-error:
-	if (csocket)
-		sock_release(csocket);
+static match_table_t tokens = {
+	{Opt_port, "port=%u"},
+	{Opt_rfdno, "rfdno=%u"},
+	{Opt_wfdno, "wfdno=%u"},
+};
 
-	kfree(trans);
-	return ERR_PTR(err);
-}
-EXPORT_SYMBOL(p9_trans_create_tcp);
+/**
+ * v9fs_parse_options - parse mount options into session structure
+ * @options: options string passed from mount
+ * @v9ses: existing v9fs session information
+ *
+ */
 
-struct p9_transport *p9_trans_create_unix(const char *addr)
+static void parse_opts(char *options, struct p9_fd_opts *opts)
 {
-	int err;
-	struct socket *csocket;
-	struct sockaddr_un sun_server;
-	struct p9_transport *trans;
-
-	csocket = NULL;
-	trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
-	if (!trans)
-		return ERR_PTR(-ENOMEM);
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int option;
+	int ret;
 
-	trans->write = p9_fd_write;
-	trans->read = p9_fd_read;
-	trans->close = p9_fd_close;
-	trans->poll = p9_fd_poll;
+	opts->port = P9_PORT;
+	opts->rfd = ~0;
+	opts->wfd = ~0;
 
-	if (strlen(addr) > UNIX_PATH_MAX) {
-		P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
-			addr);
-		err = -ENAMETOOLONG;
-		goto error;
-	}
+	if (!options)
+		return;
 
-	sun_server.sun_family = PF_UNIX;
-	strcpy(sun_server.sun_path, addr);
-	sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
-	err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
-			sizeof(struct sockaddr_un) - 1, 0);
-	if (err < 0) {
-		P9_EPRINTK(KERN_ERR,
-			"p9_trans_unix: problem connecting socket: %s: %d\n",
-			addr, err);
-		goto error;
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+		token = match_token(p, tokens, args);
+		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_port:
+			opts->port = option;
+			break;
+		case Opt_rfdno:
+			opts->rfd = option;
+			break;
+		case Opt_wfdno:
+			opts->wfd = option;
+			break;
+		default:
+			continue;
+		}
 	}
-
-	err = p9_socket_open(trans, csocket);
-	if (err < 0)
-		goto error;
-
-	return trans;
-
-error:
-	if (csocket)
-		sock_release(csocket);
-
-	kfree(trans);
-	return ERR_PTR(err);
 }
-EXPORT_SYMBOL(p9_trans_create_unix);
 
-struct p9_transport *p9_trans_create_fd(int rfd, int wfd)
+static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
 {
-	int err;
-	struct p9_transport *trans;
+	struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
+					   GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
 
-	if (rfd == ~0 || wfd == ~0) {
-		printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
-		return ERR_PTR(-ENOPROTOOPT);
+	ts->rd = fget(rfd);
+	ts->wr = fget(wfd);
+	if (!ts->rd || !ts->wr) {
+		if (ts->rd)
+			fput(ts->rd);
+		if (ts->wr)
+			fput(ts->wr);
+		kfree(ts);
+		return -EIO;
 	}
 
-	trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
-	if (!trans)
-		return ERR_PTR(-ENOMEM);
-
-	trans->write = p9_fd_write;
-	trans->read = p9_fd_read;
-	trans->close = p9_fd_close;
-	trans->poll = p9_fd_poll;
-
-	err = p9_fd_open(trans, rfd, wfd);
-	if (err < 0)
-		goto error;
-
-	return trans;
+	trans->priv = ts;
+	trans->status = Connected;
 
-error:
-	kfree(trans);
-	return ERR_PTR(err);
+	return 0;
 }
-EXPORT_SYMBOL(p9_trans_create_fd);
 
-static int p9_socket_open(struct p9_transport *trans, struct socket *csocket)
+static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
 {
 	int fd, ret;
 
@@ -212,30 +166,6 @@ static int p9_socket_open(struct p9_transport *trans, struct socket *csocket)
 	return 0;
 }
 
-static int p9_fd_open(struct p9_transport *trans, int rfd, int wfd)
-{
-	struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
-					   GFP_KERNEL);
-	if (!ts)
-		return -ENOMEM;
-
-	ts->rd = fget(rfd);
-	ts->wr = fget(wfd);
-	if (!ts->rd || !ts->wr) {
-		if (ts->rd)
-			fput(ts->rd);
-		if (ts->wr)
-			fput(ts->wr);
-		kfree(ts);
-		return -EIO;
-	}
-
-	trans->priv = ts;
-	trans->status = Connected;
-
-	return 0;
-}
-
 /**
  * p9_fd_read- read from a fd
  * @v9ses: session information
@@ -243,7 +173,7 @@ static int p9_fd_open(struct p9_transport *trans, int rfd, int wfd)
  * @len: size of receive buffer
  *
  */
-static int p9_fd_read(struct p9_transport *trans, void *v, int len)
+static int p9_fd_read(struct p9_trans *trans, void *v, int len)
 {
 	int ret;
 	struct p9_trans_fd *ts = NULL;
@@ -270,7 +200,7 @@ static int p9_fd_read(struct p9_transport *trans, void *v, int len)
  * @len: size of send buffer
  *
  */
-static int p9_fd_write(struct p9_transport *trans, void *v, int len)
+static int p9_fd_write(struct p9_trans *trans, void *v, int len)
 {
 	int ret;
 	mm_segment_t oldfs;
@@ -297,7 +227,7 @@ static int p9_fd_write(struct p9_transport *trans, void *v, int len)
 }
 
 static unsigned int
-p9_fd_poll(struct p9_transport *trans, struct poll_table_struct *pt)
+p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
 {
 	int ret, n;
 	struct p9_trans_fd *ts = NULL;
@@ -341,7 +271,7 @@ end:
  * @trans: private socket structure
  *
  */
-static void p9_fd_close(struct p9_transport *trans)
+static void p9_fd_close(struct p9_trans *trans)
 {
 	struct p9_trans_fd *ts;
 
@@ -361,3 +291,182 @@ static void p9_fd_close(struct p9_transport *trans)
 	kfree(ts);
 }
 
+static struct p9_trans *p9_trans_create_tcp(const char *addr, char *args)
+{
+	int err;
+	struct p9_trans *trans;
+	struct socket *csocket;
+	struct sockaddr_in sin_server;
+	struct p9_fd_opts opts;
+
+	parse_opts(args, &opts);
+
+	csocket = NULL;
+	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
+	if (!trans)
+		return ERR_PTR(-ENOMEM);
+
+	trans->write = p9_fd_write;
+	trans->read = p9_fd_read;
+	trans->close = p9_fd_close;
+	trans->poll = p9_fd_poll;
+
+	sin_server.sin_family = AF_INET;
+	sin_server.sin_addr.s_addr = in_aton(addr);
+	sin_server.sin_port = htons(opts.port);
+	sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
+
+	if (!csocket) {
+		P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
+		err = -EIO;
+		goto error;
+	}
+
+	err = csocket->ops->connect(csocket,
+				    (struct sockaddr *)&sin_server,
+				    sizeof(struct sockaddr_in), 0);
+	if (err < 0) {
+		P9_EPRINTK(KERN_ERR,
+			"p9_trans_tcp: problem connecting socket to %s\n",
+			addr);
+		goto error;
+	}
+
+	err = p9_socket_open(trans, csocket);
+	if (err < 0)
+		goto error;
+
+	return trans;
+
+error:
+	if (csocket)
+		sock_release(csocket);
+
+	kfree(trans);
+	return ERR_PTR(err);
+}
+
+static struct p9_trans *p9_trans_create_unix(const char *addr, char *args)
+{
+	int err;
+	struct socket *csocket;
+	struct sockaddr_un sun_server;
+	struct p9_trans *trans;
+
+	csocket = NULL;
+	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
+	if (!trans)
+		return ERR_PTR(-ENOMEM);
+
+	trans->write = p9_fd_write;
+	trans->read = p9_fd_read;
+	trans->close = p9_fd_close;
+	trans->poll = p9_fd_poll;
+
+	if (strlen(addr) > UNIX_PATH_MAX) {
+		P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
+			addr);
+		err = -ENAMETOOLONG;
+		goto error;
+	}
+
+	sun_server.sun_family = PF_UNIX;
+	strcpy(sun_server.sun_path, addr);
+	sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
+	err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
+			sizeof(struct sockaddr_un) - 1, 0);
+	if (err < 0) {
+		P9_EPRINTK(KERN_ERR,
+			"p9_trans_unix: problem connecting socket: %s: %d\n",
+			addr, err);
+		goto error;
+	}
+
+	err = p9_socket_open(trans, csocket);
+	if (err < 0)
+		goto error;
+
+	return trans;
+
+error:
+	if (csocket)
+		sock_release(csocket);
+
+	kfree(trans);
+	return ERR_PTR(err);
+}
+
+static struct p9_trans *p9_trans_create_fd(const char *name, char *args)
+{
+	int err;
+	struct p9_trans *trans;
+	struct p9_fd_opts opts;
+
+	parse_opts(args, &opts);
+
+	if (opts.rfd == ~0 || opts.wfd == ~0) {
+		printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
+		return ERR_PTR(-ENOPROTOOPT);
+	}
+
+	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
+	if (!trans)
+		return ERR_PTR(-ENOMEM);
+
+	trans->write = p9_fd_write;
+	trans->read = p9_fd_read;
+	trans->close = p9_fd_close;
+	trans->poll = p9_fd_poll;
+
+	err = p9_fd_open(trans, opts.rfd, opts.wfd);
+	if (err < 0)
+		goto error;
+
+	return trans;
+
+error:
+	kfree(trans);
+	return ERR_PTR(err);
+}
+
+static struct p9_trans_module p9_tcp_trans = {
+	.name = "tcp",
+	.maxsize = MAX_SOCK_BUF,
+	.def = 1,
+	.create = p9_trans_create_tcp,
+};
+
+static struct p9_trans_module p9_unix_trans = {
+	.name = "unix",
+	.maxsize = MAX_SOCK_BUF,
+	.def = 0,
+	.create = p9_trans_create_unix,
+};
+
+static struct p9_trans_module p9_fd_trans = {
+	.name = "fd",
+	.maxsize = MAX_SOCK_BUF,
+	.def = 0,
+	.create = p9_trans_create_fd,
+};
+
+static int __init p9_trans_fd_init(void)
+{
+	v9fs_register_trans(&p9_tcp_trans);
+	v9fs_register_trans(&p9_unix_trans);
+	v9fs_register_trans(&p9_fd_trans);
+
+	return 1;
+}
+
+static void __exit p9_trans_fd_exit(void) {
+	printk(KERN_ERR "Removal of 9p transports not implemented\n");
+	BUG();
+}
+
+module_init(p9_trans_fd_init);
+module_exit(p9_trans_fd_exit);
+
+MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
+MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
+MODULE_LICENSE("GPL");