9p: Reorganization of 9p file system code

This patchset moves non-filesystem interfaces of v9fs from fs/9p to net/9p.
It moves the transport, packet marshalling and connection layers to net/9p
leaving only the VFS related files in fs/9p.  This work is being done in
preparation for in-kernel 9p servers as well as alternate 9p clients (other
than VFS).

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 903 insertions, 0 deletions

diff --git a/net/9p/conv.c b/net/9p/conv.c
new file mode 100644
index 000000000000..37451178e761
--- /dev/null
+++ b/net/9p/conv.c
@@ -0,0 +1,903 @@
+/*
+ * net/9p/conv.c
+ *
+ * 9P protocol conversion functions
+ *
+ *  Copyright (C) 2004, 2005 by Latchesar Ionkov <lucho@ionkov.net>
+ *  Copyright (C) 2004 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
+ *  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/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/idr.h>
+#include <linux/uaccess.h>
+#include <net/9p/9p.h>
+
+/*
+ * Buffer to help with string parsing
+ */
+struct cbuf {
+	unsigned char *sp;
+	unsigned char *p;
+	unsigned char *ep;
+};
+
+static inline void buf_init(struct cbuf *buf, void *data, int datalen)
+{
+	buf->sp = buf->p = data;
+	buf->ep = data + datalen;
+}
+
+static inline int buf_check_overflow(struct cbuf *buf)
+{
+	return buf->p > buf->ep;
+}
+
+static int buf_check_size(struct cbuf *buf, int len)
+{
+	if (buf->p + len > buf->ep) {
+		if (buf->p < buf->ep) {
+			P9_EPRINTK(KERN_ERR,
+				"buffer overflow: want %d has %d\n", len,
+				(int)(buf->ep - buf->p));
+			dump_stack();
+			buf->p = buf->ep + 1;
+		}
+
+		return 0;
+	}
+
+	return 1;
+}
+
+static void *buf_alloc(struct cbuf *buf, int len)
+{
+	void *ret = NULL;
+
+	if (buf_check_size(buf, len)) {
+		ret = buf->p;
+		buf->p += len;
+	}
+
+	return ret;
+}
+
+static void buf_put_int8(struct cbuf *buf, u8 val)
+{
+	if (buf_check_size(buf, 1)) {
+		buf->p[0] = val;
+		buf->p++;
+	}
+}
+
+static void buf_put_int16(struct cbuf *buf, u16 val)
+{
+	if (buf_check_size(buf, 2)) {
+		*(__le16 *) buf->p = cpu_to_le16(val);
+		buf->p += 2;
+	}
+}
+
+static void buf_put_int32(struct cbuf *buf, u32 val)
+{
+	if (buf_check_size(buf, 4)) {
+		*(__le32 *)buf->p = cpu_to_le32(val);
+		buf->p += 4;
+	}
+}
+
+static void buf_put_int64(struct cbuf *buf, u64 val)
+{
+	if (buf_check_size(buf, 8)) {
+		*(__le64 *)buf->p = cpu_to_le64(val);
+		buf->p += 8;
+	}
+}
+
+static char *buf_put_stringn(struct cbuf *buf, const char *s, u16 slen)
+{
+	char *ret;
+
+	ret = NULL;
+	if (buf_check_size(buf, slen + 2)) {
+		buf_put_int16(buf, slen);
+		ret = buf->p;
+		memcpy(buf->p, s, slen);
+		buf->p += slen;
+	}
+
+	return ret;
+}
+
+static inline void buf_put_string(struct cbuf *buf, const char *s)
+{
+	buf_put_stringn(buf, s, strlen(s));
+}
+
+static u8 buf_get_int8(struct cbuf *buf)
+{
+	u8 ret = 0;
+
+	if (buf_check_size(buf, 1)) {
+		ret = buf->p[0];
+		buf->p++;
+	}
+
+	return ret;
+}
+
+static u16 buf_get_int16(struct cbuf *buf)
+{
+	u16 ret = 0;
+
+	if (buf_check_size(buf, 2)) {
+		ret = le16_to_cpu(*(__le16 *)buf->p);
+		buf->p += 2;
+	}
+
+	return ret;
+}
+
+static u32 buf_get_int32(struct cbuf *buf)
+{
+	u32 ret = 0;
+
+	if (buf_check_size(buf, 4)) {
+		ret = le32_to_cpu(*(__le32 *)buf->p);
+		buf->p += 4;
+	}
+
+	return ret;
+}
+
+static u64 buf_get_int64(struct cbuf *buf)
+{
+	u64 ret = 0;
+
+	if (buf_check_size(buf, 8)) {
+		ret = le64_to_cpu(*(__le64 *)buf->p);
+		buf->p += 8;
+	}
+
+	return ret;
+}
+
+static void buf_get_str(struct cbuf *buf, struct p9_str *vstr)
+{
+	vstr->len = buf_get_int16(buf);
+	if (!buf_check_overflow(buf) && buf_check_size(buf, vstr->len)) {
+		vstr->str = buf->p;
+		buf->p += vstr->len;
+	} else {
+		vstr->len = 0;
+		vstr->str = NULL;
+	}
+}
+
+static void buf_get_qid(struct cbuf *bufp, struct p9_qid *qid)
+{
+	qid->type = buf_get_int8(bufp);
+	qid->version = buf_get_int32(bufp);
+	qid->path = buf_get_int64(bufp);
+}
+
+/**
+ * p9_size_wstat - calculate the size of a variable length stat struct
+ * @stat: metadata (stat) structure
+ * @dotu: non-zero if 9P2000.u
+ *
+ */
+
+static int p9_size_wstat(struct p9_wstat *wstat, int dotu)
+{
+	int size = 0;
+
+	if (wstat == NULL) {
+		P9_EPRINTK(KERN_ERR, "p9_size_stat: got a NULL stat pointer\n");
+		return 0;
+	}
+
+	size =			/* 2 + *//* size[2] */
+	    2 +			/* type[2] */
+	    4 +			/* dev[4] */
+	    1 +			/* qid.type[1] */
+	    4 +			/* qid.vers[4] */
+	    8 +			/* qid.path[8] */
+	    4 +			/* mode[4] */
+	    4 +			/* atime[4] */
+	    4 +			/* mtime[4] */
+	    8 +			/* length[8] */
+	    8;			/* minimum sum of string lengths */
+
+	if (wstat->name)
+		size += strlen(wstat->name);
+	if (wstat->uid)
+		size += strlen(wstat->uid);
+	if (wstat->gid)
+		size += strlen(wstat->gid);
+	if (wstat->muid)
+		size += strlen(wstat->muid);
+
+	if (dotu) {
+		size += 4 +	/* n_uid[4] */
+		    4 +		/* n_gid[4] */
+		    4 +		/* n_muid[4] */
+		    2;		/* string length of extension[4] */
+		if (wstat->extension)
+			size += strlen(wstat->extension);
+	}
+
+	return size;
+}
+
+/**
+ * buf_get_stat - safely decode a recieved metadata (stat) structure
+ * @bufp: buffer to deserialize
+ * @stat: metadata (stat) structure
+ * @dotu: non-zero if 9P2000.u
+ *
+ */
+
+static void
+buf_get_stat(struct cbuf *bufp, struct p9_stat *stat, int dotu)
+{
+	stat->size = buf_get_int16(bufp);
+	stat->type = buf_get_int16(bufp);
+	stat->dev = buf_get_int32(bufp);
+	stat->qid.type = buf_get_int8(bufp);
+	stat->qid.version = buf_get_int32(bufp);
+	stat->qid.path = buf_get_int64(bufp);
+	stat->mode = buf_get_int32(bufp);
+	stat->atime = buf_get_int32(bufp);
+	stat->mtime = buf_get_int32(bufp);
+	stat->length = buf_get_int64(bufp);
+	buf_get_str(bufp, &stat->name);
+	buf_get_str(bufp, &stat->uid);
+	buf_get_str(bufp, &stat->gid);
+	buf_get_str(bufp, &stat->muid);
+
+	if (dotu) {
+		buf_get_str(bufp, &stat->extension);
+		stat->n_uid = buf_get_int32(bufp);
+		stat->n_gid = buf_get_int32(bufp);
+		stat->n_muid = buf_get_int32(bufp);
+	}
+}
+
+/**
+ * p9_deserialize_stat - decode a received metadata structure
+ * @buf: buffer to deserialize
+ * @buflen: length of received buffer
+ * @stat: metadata structure to decode into
+ * @dotu: non-zero if 9P2000.u
+ *
+ * Note: stat will point to the buf region.
+ */
+
+int
+p9_deserialize_stat(void *buf, u32 buflen, struct p9_stat *stat,
+		int dotu)
+{
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+	unsigned char *p;
+
+	buf_init(bufp, buf, buflen);
+	p = bufp->p;
+	buf_get_stat(bufp, stat, dotu);
+
+	if (buf_check_overflow(bufp))
+		return 0;
+	else
+		return bufp->p - p;
+}
+EXPORT_SYMBOL(p9_deserialize_stat);
+
+/**
+ * deserialize_fcall - unmarshal a response
+ * @buf: recieved buffer
+ * @buflen: length of received buffer
+ * @rcall: fcall structure to populate
+ * @rcalllen: length of fcall structure to populate
+ * @dotu: non-zero if 9P2000.u
+ *
+ */
+
+int
+p9_deserialize_fcall(void *buf, u32 buflen, struct p9_fcall *rcall,
+		       int dotu)
+{
+
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+	int i = 0;
+
+	buf_init(bufp, buf, buflen);
+
+	rcall->size = buf_get_int32(bufp);
+	rcall->id = buf_get_int8(bufp);
+	rcall->tag = buf_get_int16(bufp);
+
+	P9_DPRINTK(P9_DEBUG_CONV, "size %d id %d tag %d\n", rcall->size,
+							rcall->id, rcall->tag);
+
+	switch (rcall->id) {
+	default:
+		P9_EPRINTK(KERN_ERR, "unknown message type: %d\n", rcall->id);
+		return -EPROTO;
+	case P9_RVERSION:
+		rcall->params.rversion.msize = buf_get_int32(bufp);
+		buf_get_str(bufp, &rcall->params.rversion.version);
+		break;
+	case P9_RFLUSH:
+		break;
+	case P9_RATTACH:
+		rcall->params.rattach.qid.type = buf_get_int8(bufp);
+		rcall->params.rattach.qid.version = buf_get_int32(bufp);
+		rcall->params.rattach.qid.path = buf_get_int64(bufp);
+		break;
+	case P9_RWALK:
+		rcall->params.rwalk.nwqid = buf_get_int16(bufp);
+		if (rcall->params.rwalk.nwqid > P9_MAXWELEM) {
+			P9_EPRINTK(KERN_ERR,
+					"Rwalk with more than %d qids: %d\n",
+					P9_MAXWELEM, rcall->params.rwalk.nwqid);
+			return -EPROTO;
+		}
+
+		for (i = 0; i < rcall->params.rwalk.nwqid; i++)
+			buf_get_qid(bufp, &rcall->params.rwalk.wqids[i]);
+		break;
+	case P9_ROPEN:
+		buf_get_qid(bufp, &rcall->params.ropen.qid);
+		rcall->params.ropen.iounit = buf_get_int32(bufp);
+		break;
+	case P9_RCREATE:
+		buf_get_qid(bufp, &rcall->params.rcreate.qid);
+		rcall->params.rcreate.iounit = buf_get_int32(bufp);
+		break;
+	case P9_RREAD:
+		rcall->params.rread.count = buf_get_int32(bufp);
+		rcall->params.rread.data = bufp->p;
+		buf_check_size(bufp, rcall->params.rread.count);
+		break;
+	case P9_RWRITE:
+		rcall->params.rwrite.count = buf_get_int32(bufp);
+		break;
+	case P9_RCLUNK:
+		break;
+	case P9_RREMOVE:
+		break;
+	case P9_RSTAT:
+		buf_get_int16(bufp);
+		buf_get_stat(bufp, &rcall->params.rstat.stat, dotu);
+		break;
+	case P9_RWSTAT:
+		break;
+	case P9_RERROR:
+		buf_get_str(bufp, &rcall->params.rerror.error);
+		if (dotu)
+			rcall->params.rerror.errno = buf_get_int16(bufp);
+		break;
+	}
+
+	if (buf_check_overflow(bufp)) {
+		P9_DPRINTK(P9_DEBUG_ERROR, "buffer overflow\n");
+		return -EIO;
+	}
+
+	return bufp->p - bufp->sp;
+}
+EXPORT_SYMBOL(p9_deserialize_fcall);
+
+static inline void p9_put_int8(struct cbuf *bufp, u8 val, u8 * p)
+{
+	*p = val;
+	buf_put_int8(bufp, val);
+}
+
+static inline void p9_put_int16(struct cbuf *bufp, u16 val, u16 * p)
+{
+	*p = val;
+	buf_put_int16(bufp, val);
+}
+
+static inline void p9_put_int32(struct cbuf *bufp, u32 val, u32 * p)
+{
+	*p = val;
+	buf_put_int32(bufp, val);
+}
+
+static inline void p9_put_int64(struct cbuf *bufp, u64 val, u64 * p)
+{
+	*p = val;
+	buf_put_int64(bufp, val);
+}
+
+static void
+p9_put_str(struct cbuf *bufp, char *data, struct p9_str *str)
+{
+	int len;
+	char *s;
+
+	if (data)
+		len = strlen(data);
+	else
+		len = 0;
+
+	s = buf_put_stringn(bufp, data, len);
+	if (str) {
+		str->len = len;
+		str->str = s;
+	}
+}
+
+static int
+p9_put_data(struct cbuf *bufp, const char *data, int count,
+		   unsigned char **pdata)
+{
+	*pdata = buf_alloc(bufp, count);
+	memmove(*pdata, data, count);
+	return count;
+}
+
+static int
+p9_put_user_data(struct cbuf *bufp, const char __user *data, int count,
+		   unsigned char **pdata)
+{
+	*pdata = buf_alloc(bufp, count);
+	return copy_from_user(*pdata, data, count);
+}
+
+static void
+p9_put_wstat(struct cbuf *bufp, struct p9_wstat *wstat,
+	       struct p9_stat *stat, int statsz, int dotu)
+{
+	p9_put_int16(bufp, statsz, &stat->size);
+	p9_put_int16(bufp, wstat->type, &stat->type);
+	p9_put_int32(bufp, wstat->dev, &stat->dev);
+	p9_put_int8(bufp, wstat->qid.type, &stat->qid.type);
+	p9_put_int32(bufp, wstat->qid.version, &stat->qid.version);
+	p9_put_int64(bufp, wstat->qid.path, &stat->qid.path);
+	p9_put_int32(bufp, wstat->mode, &stat->mode);
+	p9_put_int32(bufp, wstat->atime, &stat->atime);
+	p9_put_int32(bufp, wstat->mtime, &stat->mtime);
+	p9_put_int64(bufp, wstat->length, &stat->length);
+
+	p9_put_str(bufp, wstat->name, &stat->name);
+	p9_put_str(bufp, wstat->uid, &stat->uid);
+	p9_put_str(bufp, wstat->gid, &stat->gid);
+	p9_put_str(bufp, wstat->muid, &stat->muid);
+
+	if (dotu) {
+		p9_put_str(bufp, wstat->extension, &stat->extension);
+		p9_put_int32(bufp, wstat->n_uid, &stat->n_uid);
+		p9_put_int32(bufp, wstat->n_gid, &stat->n_gid);
+		p9_put_int32(bufp, wstat->n_muid, &stat->n_muid);
+	}
+}
+
+static struct p9_fcall *
+p9_create_common(struct cbuf *bufp, u32 size, u8 id)
+{
+	struct p9_fcall *fc;
+
+	size += 4 + 1 + 2;	/* size[4] id[1] tag[2] */
+	fc = kmalloc(sizeof(struct p9_fcall) + size, GFP_KERNEL);
+	if (!fc)
+		return ERR_PTR(-ENOMEM);
+
+	fc->sdata = (char *)fc + sizeof(*fc);
+
+	buf_init(bufp, (char *)fc->sdata, size);
+	p9_put_int32(bufp, size, &fc->size);
+	p9_put_int8(bufp, id, &fc->id);
+	p9_put_int16(bufp, P9_NOTAG, &fc->tag);
+
+	return fc;
+}
+
+void p9_set_tag(struct p9_fcall *fc, u16 tag)
+{
+	fc->tag = tag;
+	*(__le16 *) (fc->sdata + 5) = cpu_to_le16(tag);
+}
+EXPORT_SYMBOL(p9_set_tag);
+
+struct p9_fcall *p9_create_tversion(u32 msize, char *version)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	size = 4 + 2 + strlen(version);	/* msize[4] version[s] */
+	fc = p9_create_common(bufp, size, P9_TVERSION);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, msize, &fc->params.tversion.msize);
+	p9_put_str(bufp, version, &fc->params.tversion.version);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tversion);
+
+struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	/* afid[4] uname[s] aname[s] */
+	size = 4 + 2 + strlen(uname) + 2 + strlen(aname);
+	fc = p9_create_common(bufp, size, P9_TAUTH);
+	if (IS_ERR(fc))
+		goto error;
+
+	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 (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tauth);
+
+struct p9_fcall *
+p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	/* fid[4] afid[4] uname[s] aname[s] */
+	size = 4 + 4 + 2 + strlen(uname) + 2 + strlen(aname);
+	fc = p9_create_common(bufp, size, P9_TATTACH);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.tattach.fid);
+	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);
+
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tattach);
+
+struct p9_fcall *p9_create_tflush(u16 oldtag)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	size = 2;		/* oldtag[2] */
+	fc = p9_create_common(bufp, size, P9_TFLUSH);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int16(bufp, oldtag, &fc->params.tflush.oldtag);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tflush);
+
+struct p9_fcall *p9_create_twalk(u32 fid, u32 newfid, u16 nwname,
+				     char **wnames)
+{
+	int i, size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	if (nwname > P9_MAXWELEM) {
+		P9_DPRINTK(P9_DEBUG_ERROR, "nwname > %d\n", P9_MAXWELEM);
+		return NULL;
+	}
+
+	size = 4 + 4 + 2;	/* fid[4] newfid[4] nwname[2] ... */
+	for (i = 0; i < nwname; i++) {
+		size += 2 + strlen(wnames[i]);	/* wname[s] */
+	}
+
+	fc = p9_create_common(bufp, size, P9_TWALK);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.twalk.fid);
+	p9_put_int32(bufp, newfid, &fc->params.twalk.newfid);
+	p9_put_int16(bufp, nwname, &fc->params.twalk.nwname);
+	for (i = 0; i < nwname; i++) {
+		p9_put_str(bufp, wnames[i], &fc->params.twalk.wnames[i]);
+	}
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_twalk);
+
+struct p9_fcall *p9_create_topen(u32 fid, u8 mode)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	size = 4 + 1;		/* fid[4] mode[1] */
+	fc = p9_create_common(bufp, size, P9_TOPEN);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.topen.fid);
+	p9_put_int8(bufp, mode, &fc->params.topen.mode);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_topen);
+
+struct p9_fcall *p9_create_tcreate(u32 fid, char *name, u32 perm, u8 mode,
+	char *extension, int dotu)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	/* fid[4] name[s] perm[4] mode[1] */
+	size = 4 + 2 + strlen(name) + 4 + 1;
+	if (dotu) {
+		size += 2 +			/* extension[s] */
+		    (extension == NULL ? 0 : strlen(extension));
+	}
+
+	fc = p9_create_common(bufp, size, P9_TCREATE);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.tcreate.fid);
+	p9_put_str(bufp, name, &fc->params.tcreate.name);
+	p9_put_int32(bufp, perm, &fc->params.tcreate.perm);
+	p9_put_int8(bufp, mode, &fc->params.tcreate.mode);
+	if (dotu)
+		p9_put_str(bufp, extension, &fc->params.tcreate.extension);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tcreate);
+
+struct p9_fcall *p9_create_tread(u32 fid, u64 offset, u32 count)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	size = 4 + 8 + 4;	/* fid[4] offset[8] count[4] */
+	fc = p9_create_common(bufp, size, P9_TREAD);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.tread.fid);
+	p9_put_int64(bufp, offset, &fc->params.tread.offset);
+	p9_put_int32(bufp, count, &fc->params.tread.count);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tread);
+
+struct p9_fcall *p9_create_twrite(u32 fid, u64 offset, u32 count,
+				      const char *data)
+{
+	int size, err;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	/* fid[4] offset[8] count[4] data[count] */
+	size = 4 + 8 + 4 + count;
+	fc = p9_create_common(bufp, size, P9_TWRITE);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.twrite.fid);
+	p9_put_int64(bufp, offset, &fc->params.twrite.offset);
+	p9_put_int32(bufp, count, &fc->params.twrite.count);
+	err = p9_put_data(bufp, data, count, &fc->params.twrite.data);
+	if (err) {
+		kfree(fc);
+		fc = ERR_PTR(err);
+	}
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_twrite);
+
+struct p9_fcall *p9_create_twrite_u(u32 fid, u64 offset, u32 count,
+				      const char __user *data)
+{
+	int size, err;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	/* fid[4] offset[8] count[4] data[count] */
+	size = 4 + 8 + 4 + count;
+	fc = p9_create_common(bufp, size, P9_TWRITE);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.twrite.fid);
+	p9_put_int64(bufp, offset, &fc->params.twrite.offset);
+	p9_put_int32(bufp, count, &fc->params.twrite.count);
+	err = p9_put_user_data(bufp, data, count, &fc->params.twrite.data);
+	if (err) {
+		kfree(fc);
+		fc = ERR_PTR(err);
+	}
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_twrite_u);
+
+struct p9_fcall *p9_create_tclunk(u32 fid)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	size = 4;		/* fid[4] */
+	fc = p9_create_common(bufp, size, P9_TCLUNK);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.tclunk.fid);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tclunk);
+
+struct p9_fcall *p9_create_tremove(u32 fid)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	size = 4;		/* fid[4] */
+	fc = p9_create_common(bufp, size, P9_TREMOVE);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.tremove.fid);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tremove);
+
+struct p9_fcall *p9_create_tstat(u32 fid)
+{
+	int size;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	size = 4;		/* fid[4] */
+	fc = p9_create_common(bufp, size, P9_TSTAT);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.tstat.fid);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_tstat);
+
+struct p9_fcall *p9_create_twstat(u32 fid, struct p9_wstat *wstat,
+				      int dotu)
+{
+	int size, statsz;
+	struct p9_fcall *fc;
+	struct cbuf buffer;
+	struct cbuf *bufp = &buffer;
+
+	statsz = p9_size_wstat(wstat, dotu);
+	size = 4 + 2 + 2 + statsz;	/* fid[4] stat[n] */
+	fc = p9_create_common(bufp, size, P9_TWSTAT);
+	if (IS_ERR(fc))
+		goto error;
+
+	p9_put_int32(bufp, fid, &fc->params.twstat.fid);
+	buf_put_int16(bufp, statsz + 2);
+	p9_put_wstat(bufp, wstat, &fc->params.twstat.stat, statsz, dotu);
+
+	if (buf_check_overflow(bufp)) {
+		kfree(fc);
+		fc = ERR_PTR(-ENOMEM);
+	}
+error:
+	return fc;
+}
+EXPORT_SYMBOL(p9_create_twstat);