[deliverable/linux.git] / net / 9p / client.c

/*
 * net/9p/clnt.c
 *
 * 9P Client
 *
 *  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/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/mutex.h>
#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>

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);

/**
 * p9_client_rpc - sends 9P request and waits until a response is available.
 *      The function can be interrupted.
 * @c: client data
 * @tc: request to be sent
 * @rc: pointer where a pointer to the response is stored
 */
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);
}

struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
								   int dotu)
{
	int err, n;
	struct p9_client *clnt;
	struct p9_fcall *tc, *rc;
	struct p9_str *version;

	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
	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) {
		err = PTR_ERR(clnt->fidpool);
		clnt->fidpool = NULL;
		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;
		goto error;
	}

	tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto error;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto error;

	version = &rc->params.rversion.version;
	if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
		clnt->dotu = 1;
	else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
		clnt->dotu = 0;
	else {
		err = -EREMOTEIO;
		goto error;
	}

	n = rc->params.rversion.msize;
	if (n < clnt->msize)
		clnt->msize = n;

	kfree(tc);
	kfree(rc);
	return clnt;

error:
	kfree(tc);
	kfree(rc);
	p9_client_destroy(clnt);
	return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_client_create);

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);
		kfree(clnt->trans);
		clnt->trans = NULL;
	}

	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
		p9_fid_destroy(fid);

	if (clnt->fidpool)
		p9_idpool_destroy(clnt->fidpool);

	kfree(clnt);
}
EXPORT_SYMBOL(p9_client_destroy);

void p9_client_disconnect(struct p9_client *clnt)
{
	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
	clnt->trans->status = Disconnected;
	p9_conn_cancel(clnt->conn, -EIO);
}
EXPORT_SYMBOL(p9_client_disconnect);

struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
	char *uname, u32 n_uname, char *aname)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_fid *fid;

	P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
		clnt, afid?afid->fid:-1, uname, aname);
	err = 0;
	tc = NULL;
	rc = NULL;

	fid = p9_fid_create(clnt);
	if (IS_ERR(fid)) {
		err = PTR_ERR(fid);
		fid = NULL;
		goto error;
	}

	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;
		goto error;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto error;

	memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
	kfree(tc);
	kfree(rc);
	return fid;

error:
	kfree(tc);
	kfree(rc);
	if (fid)
		p9_fid_destroy(fid);
	return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_client_attach);

struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
	u32 n_uname, char *aname)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_fid *fid;

	P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
									aname);
	err = 0;
	tc = NULL;
	rc = NULL;

	fid = p9_fid_create(clnt);
	if (IS_ERR(fid)) {
		err = PTR_ERR(fid);
		fid = NULL;
		goto error;
	}

	tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto error;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto error;

	memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
	kfree(tc);
	kfree(rc);
	return fid;

error:
	kfree(tc);
	kfree(rc);
	if (fid)
		p9_fid_destroy(fid);
	return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_client_auth);

struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
	int clone)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;
	struct p9_fid *fid;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
		oldfid->fid, nwname, wnames?wnames[0]:NULL);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = oldfid->clnt;
	if (clone) {
		fid = p9_fid_create(clnt);
		if (IS_ERR(fid)) {
			err = PTR_ERR(fid);
			fid = NULL;
			goto error;
		}

		fid->uid = oldfid->uid;
	} else
		fid = oldfid;

	tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto error;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err) {
		if (rc && rc->id == P9_RWALK)
			goto clunk_fid;
		else
			goto error;
	}

	if (rc->params.rwalk.nwqid != nwname) {
		err = -ENOENT;
		goto clunk_fid;
	}

	if (nwname)
		memmove(&fid->qid,
			&rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
			sizeof(struct p9_qid));
	else
		fid->qid = oldfid->qid;

	kfree(tc);
	kfree(rc);
	return fid;

clunk_fid:
	kfree(tc);
	kfree(rc);
	rc = NULL;
	tc = p9_create_tclunk(fid->fid);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto error;
	}

	p9_client_rpc(clnt, tc, &rc);

error:
	kfree(tc);
	kfree(rc);
	if (fid && (fid != oldfid))
		p9_fid_destroy(fid);

	return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_client_walk);

int p9_client_open(struct p9_fid *fid, int mode)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;

	if (fid->mode != -1)
		return -EINVAL;

	tc = p9_create_topen(fid->fid, mode);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto done;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto done;

	fid->mode = mode;
	fid->iounit = rc->params.ropen.iounit;

done:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_open);

int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
		     char *extension)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
		name, perm, mode);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;

	if (fid->mode != -1)
		return -EINVAL;

	tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
							       clnt->dotu);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto done;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto done;

	fid->mode = mode;
	fid->iounit = rc->params.ropen.iounit;

done:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_fcreate);

int p9_client_clunk(struct p9_fid *fid)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;

	tc = p9_create_tclunk(fid->fid);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto done;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto done;

	p9_fid_destroy(fid);

done:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_clunk);

int p9_client_remove(struct p9_fid *fid)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;

	tc = p9_create_tremove(fid->fid);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto done;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto done;

	p9_fid_destroy(fid);

done:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_remove);

int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count)
{
	int err, n, rsize, total;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
					(long long unsigned) offset, count);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;
	total = 0;

	rsize = fid->iounit;
	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
		rsize = clnt->msize - P9_IOHDRSZ;

	do {
		if (count < rsize)
			rsize = count;

		tc = p9_create_tread(fid->fid, offset, rsize);
		if (IS_ERR(tc)) {
			err = PTR_ERR(tc);
			tc = NULL;
			goto error;
		}

		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
			goto error;

		n = rc->params.rread.count;
		if (n > count)
			n = count;

		memmove(data, rc->params.rread.data, n);
		count -= n;
		data += n;
		offset += n;
		total += n;
		kfree(tc);
		tc = NULL;
		kfree(rc);
		rc = NULL;
	} while (count > 0 && n == rsize);

	return total;

error:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_read);

int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count)
{
	int err, n, rsize, total;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
					(long long unsigned) offset, count);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;
	total = 0;

	rsize = fid->iounit;
	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
		rsize = clnt->msize - P9_IOHDRSZ;

	do {
		if (count < rsize)
			rsize = count;

		tc = p9_create_twrite(fid->fid, offset, rsize, data);
		if (IS_ERR(tc)) {
			err = PTR_ERR(tc);
			tc = NULL;
			goto error;
		}

		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
			goto error;

		n = rc->params.rread.count;
		count -= n;
		data += n;
		offset += n;
		total += n;
		kfree(tc);
		tc = NULL;
		kfree(rc);
		rc = NULL;
	} while (count > 0);

	return total;

error:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_write);

int
p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset, u32 count)
{
	int err, n, rsize, total;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
					(long long unsigned) offset, count);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;
	total = 0;

	rsize = fid->iounit;
	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
		rsize = clnt->msize - P9_IOHDRSZ;

	do {
		if (count < rsize)
			rsize = count;

		tc = p9_create_tread(fid->fid, offset, rsize);
		if (IS_ERR(tc)) {
			err = PTR_ERR(tc);
			tc = NULL;
			goto error;
		}

		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
			goto error;

		n = rc->params.rread.count;
		if (n > count)
			n = count;

		err = copy_to_user(data, rc->params.rread.data, n);
		if (err) {
			err = -EFAULT;
			goto error;
		}

		count -= n;
		data += n;
		offset += n;
		total += n;
		kfree(tc);
		tc = NULL;
		kfree(rc);
		rc = NULL;
	} while (count > 0 && n == rsize);

	return total;

error:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_uread);

int
p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
								   u32 count)
{
	int err, n, rsize, total;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
					(long long unsigned) offset, count);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;
	total = 0;

	rsize = fid->iounit;
	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
		rsize = clnt->msize - P9_IOHDRSZ;

	do {
		if (count < rsize)
			rsize = count;

		tc = p9_create_twrite_u(fid->fid, offset, rsize, data);
		if (IS_ERR(tc)) {
			err = PTR_ERR(tc);
			tc = NULL;
			goto error;
		}

		err = p9_client_rpc(clnt, tc, &rc);
		if (err)
			goto error;

		n = rc->params.rread.count;
		count -= n;
		data += n;
		offset += n;
		total += n;
		kfree(tc);
		tc = NULL;
		kfree(rc);
		rc = NULL;
	} while (count > 0);

	return total;

error:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_uwrite);

int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count)
{
	int n, total;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
					(long long unsigned) offset, count);
	n = 0;
	total = 0;
	while (count) {
		n = p9_client_read(fid, data, offset, count);
		if (n <= 0)
			break;

		data += n;
		offset += n;
		count -= n;
		total += n;
	}

	if (n < 0)
		total = n;

	return total;
}
EXPORT_SYMBOL(p9_client_readn);

struct p9_stat *p9_client_stat(struct p9_fid *fid)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;
	struct p9_stat *ret;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	err = 0;
	tc = NULL;
	rc = NULL;
	ret = NULL;
	clnt = fid->clnt;

	tc = p9_create_tstat(fid->fid);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto error;
	}

	err = p9_client_rpc(clnt, tc, &rc);
	if (err)
		goto error;

	ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
	if (IS_ERR(ret)) {
		err = PTR_ERR(ret);
		ret = NULL;
		goto error;
	}

	kfree(tc);
	kfree(rc);
	return ret;

error:
	kfree(tc);
	kfree(rc);
	kfree(ret);
	return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_client_stat);

int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
{
	int err;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	err = 0;
	tc = NULL;
	rc = NULL;
	clnt = fid->clnt;

	tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
	if (IS_ERR(tc)) {
		err = PTR_ERR(tc);
		tc = NULL;
		goto done;
	}

	err = p9_client_rpc(clnt, tc, &rc);

done:
	kfree(tc);
	kfree(rc);
	return err;
}
EXPORT_SYMBOL(p9_client_wstat);

struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset)
{
	int err, n, m;
	struct p9_fcall *tc, *rc;
	struct p9_client *clnt;
	struct p9_stat st, *ret;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu\n", fid->fid,
						(long long unsigned) offset);
	err = 0;
	tc = NULL;
	rc = NULL;
	ret = NULL;
	clnt = fid->clnt;

	/* if the offset is below or above the current response, free it */
	if (offset < fid->rdir_fpos || (fid->rdir_fcall &&
		offset >= fid->rdir_fpos+fid->rdir_fcall->params.rread.count)) {
		fid->rdir_pos = 0;
		if (fid->rdir_fcall)
			fid->rdir_fpos += fid->rdir_fcall->params.rread.count;

		kfree(fid->rdir_fcall);
		fid->rdir_fcall = NULL;
		if (offset < fid->rdir_fpos)
			fid->rdir_fpos = 0;
	}

	if (!fid->rdir_fcall) {
		n = fid->iounit;
		if (!n || n > clnt->msize-P9_IOHDRSZ)
			n = clnt->msize - P9_IOHDRSZ;

		while (1) {
			if (fid->rdir_fcall) {
				fid->rdir_fpos +=
					fid->rdir_fcall->params.rread.count;
				kfree(fid->rdir_fcall);
				fid->rdir_fcall = NULL;
			}

			tc = p9_create_tread(fid->fid, fid->rdir_fpos, n);
			if (IS_ERR(tc)) {
				err = PTR_ERR(tc);
				tc = NULL;
				goto error;
			}

			err = p9_client_rpc(clnt, tc, &rc);
			if (err)
				goto error;

			n = rc->params.rread.count;
			if (n == 0)
				goto done;

			fid->rdir_fcall = rc;
			rc = NULL;
			if (offset >= fid->rdir_fpos &&
						offset < fid->rdir_fpos+n)
				break;
		}

		fid->rdir_pos = 0;
	}

	m = offset - fid->rdir_fpos;
	if (m < 0)
		goto done;

	n = p9_deserialize_stat(fid->rdir_fcall->params.rread.data + m,
		fid->rdir_fcall->params.rread.count - m, &st, clnt->dotu);

	if (!n) {
		err = -EIO;
		goto error;
	}

	fid->rdir_pos += n;
	st.size = n;
	ret = p9_clone_stat(&st, clnt->dotu);
	if (IS_ERR(ret)) {
		err = PTR_ERR(ret);
		ret = NULL;
		goto error;
	}

done:
	kfree(tc);
	kfree(rc);
	return ret;

error:
	kfree(tc);
	kfree(rc);
	kfree(ret);
	return ERR_PTR(err);
}
EXPORT_SYMBOL(p9_client_dirread);

static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu)
{
	int n;
	char *p;
	struct p9_stat *ret;

	n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
		st->muid.len;

	if (dotu)
		n += st->extension.len;

	ret = kmalloc(n, GFP_KERNEL);
	if (!ret)
		return ERR_PTR(-ENOMEM);

	memmove(ret, st, sizeof(struct p9_stat));
	p = ((char *) ret) + sizeof(struct p9_stat);
	memmove(p, st->name.str, st->name.len);
	ret->name.str = p;
	p += st->name.len;
	memmove(p, st->uid.str, st->uid.len);
	ret->uid.str = p;
	p += st->uid.len;
	memmove(p, st->gid.str, st->gid.len);
	ret->gid.str = p;
	p += st->gid.len;
	memmove(p, st->muid.str, st->muid.len);
	ret->muid.str = p;
	p += st->muid.len;

	if (dotu) {
		memmove(p, st->extension.str, st->extension.len);
		ret->extension.str = p;
		p += st->extension.len;
	}

	return ret;
}

static struct p9_fid *p9_fid_create(struct p9_client *clnt)
{
	int err;
	struct p9_fid *fid;

	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
	if (!fid)
		return ERR_PTR(-ENOMEM);

	fid->fid = p9_idpool_get(clnt->fidpool);
	if (fid->fid < 0) {
		err = -ENOSPC;
		goto error;
	}

	memset(&fid->qid, 0, sizeof(struct p9_qid));
	fid->mode = -1;
	fid->rdir_fpos = 0;
	fid->rdir_pos = 0;
	fid->rdir_fcall = NULL;
	fid->uid = current->fsuid;
	fid->clnt = clnt;
	fid->aux = NULL;

	spin_lock(&clnt->lock);
	list_add(&fid->flist, &clnt->fidlist);
	spin_unlock(&clnt->lock);

	return fid;

error:
	kfree(fid);
	return ERR_PTR(err);
}

static void p9_fid_destroy(struct p9_fid *fid)
{
	struct p9_client *clnt;

	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	clnt = fid->clnt;
	p9_idpool_put(fid->fid, clnt->fidpool);
	spin_lock(&clnt->lock);
	list_del(&fid->flist);
	spin_unlock(&clnt->lock);
	kfree(fid->rdir_fcall);
	kfree(fid);
}
Commit	Line	Data
bd238fb4 LI	1	/*
	2	* net/9p/clnt.c
	3	*
	4	* 9P Client
	5	*
	6	* Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2
	10	* as published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to:
	19	* Free Software Foundation
	20	* 51 Franklin Street, Fifth Floor
	21	* Boston, MA 02111-1301 USA
	22	*
	23	*/
	24
	25	#include <linux/module.h>
	26	#include <linux/errno.h>
	27	#include <linux/fs.h>
	28	#include <linux/idr.h>
	29	#include <linux/mutex.h>
	30	#include <linux/sched.h>
	31	#include <linux/uaccess.h>
	32	#include <net/9p/9p.h>
fb0466c3	33	#include <linux/parser.h>
bd238fb4 LI	34	#include <net/9p/transport.h>
	35	#include <net/9p/conn.h>
	36	#include <net/9p/client.h>
	37
	38	static struct p9_fid p9_fid_create(struct p9_client clnt);
	39	static void p9_fid_destroy(struct p9_fid *fid);
	40	static struct p9_stat p9_clone_stat(struct p9_stat st, int dotu);
	41
043aba40 EVH	42	/**
	43	* p9_client_rpc - sends 9P request and waits until a response is available.
	44	* The function can be interrupted.
	45	* @c: client data
	46	* @tc: request to be sent
	47	* @rc: pointer where a pointer to the response is stored
	48	*/
	49	int
	50	p9_client_rpc(struct p9_client c, struct p9_fcall tc,
	51	struct p9_fcall **rc)
	52	{
	53	if (c->trans->rpc)
e2735b77	54	return c->trans->rpc(c->trans, tc, rc, c->msize, c->dotu);
043aba40 EVH	55	else
	56	return p9_conn_rpc(c->conn, tc, rc);
	57	}
	58
a80d923e	59	struct p9_client p9_client_create(struct p9_trans trans, int msize,
bd238fb4 LI	60	int dotu)
	61	{
	62	int err, n;
	63	struct p9_client *clnt;
	64	struct p9_fcall tc, rc;
	65	struct p9_str *version;
	66
	67	err = 0;
	68	tc = NULL;
	69	rc = NULL;
	70	clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
	71	if (!clnt)
	72	return ERR_PTR(-ENOMEM);
	73
	74	P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
	75	clnt, trans, msize, dotu);
	76	spin_lock_init(&clnt->lock);
	77	clnt->trans = trans;
	78	clnt->msize = msize;
	79	clnt->dotu = dotu;
	80	INIT_LIST_HEAD(&clnt->fidlist);
	81	clnt->fidpool = p9_idpool_create();
	82	if (!clnt->fidpool) {
	83	err = PTR_ERR(clnt->fidpool);
	84	clnt->fidpool = NULL;
	85	goto error;
	86	}
	87
	88	clnt->conn = p9_conn_create(clnt->trans, clnt->msize, &clnt->dotu);
	89	if (IS_ERR(clnt->conn)) {
	90	err = PTR_ERR(clnt->conn);
	91	clnt->conn = NULL;
	92	goto error;
	93	}
	94
	95	tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
	96	if (IS_ERR(tc)) {
	97	err = PTR_ERR(tc);
	98	tc = NULL;
	99	goto error;
	100	}
	101
e2735b77	102	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	103	if (err)
	104	goto error;
	105
	106	version = &rc->params.rversion.version;
	107	if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
	108	clnt->dotu = 1;
	109	else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
	110	clnt->dotu = 0;
	111	else {
	112	err = -EREMOTEIO;
	113	goto error;
	114	}
	115
	116	n = rc->params.rversion.msize;
	117	if (n < clnt->msize)
	118	clnt->msize = n;
	119
	120	kfree(tc);
	121	kfree(rc);
	122	return clnt;
	123
	124	error:
	125	kfree(tc);
	126	kfree(rc);
	127	p9_client_destroy(clnt);
	128	return ERR_PTR(err);
	129	}
	130	EXPORT_SYMBOL(p9_client_create);
	131
	132	void p9_client_destroy(struct p9_client *clnt)
	133	{
	134	struct p9_fid fid, fidptr;
	135
	136	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
	137	if (clnt->conn) {
	138	p9_conn_destroy(clnt->conn);
	139	clnt->conn = NULL;
	140	}
	141
	142	if (clnt->trans) {
	143	clnt->trans->close(clnt->trans);
	144	kfree(clnt->trans);
	145	clnt->trans = NULL;
	146	}
	147
bd238fb4 LI	148	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
	149	p9_fid_destroy(fid);
	150
0af8887e EVH	151	if (clnt->fidpool)
	152	p9_idpool_destroy(clnt->fidpool);
	153
bd238fb4 LI	154	kfree(clnt);
	155	}
	156	EXPORT_SYMBOL(p9_client_destroy);
	157
	158	void p9_client_disconnect(struct p9_client *clnt)
	159	{
	160	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
	161	clnt->trans->status = Disconnected;
	162	p9_conn_cancel(clnt->conn, -EIO);
	163	}
	164	EXPORT_SYMBOL(p9_client_disconnect);
	165
	166	struct p9_fid p9_client_attach(struct p9_client clnt, struct p9_fid *afid,
ba17674f	167	char uname, u32 n_uname, char aname)
bd238fb4 LI	168	{
	169	int err;
	170	struct p9_fcall tc, rc;
	171	struct p9_fid *fid;
	172
	173	P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
	174	clnt, afid?afid->fid:-1, uname, aname);
	175	err = 0;
	176	tc = NULL;
	177	rc = NULL;
	178
	179	fid = p9_fid_create(clnt);
	180	if (IS_ERR(fid)) {
	181	err = PTR_ERR(fid);
	182	fid = NULL;
	183	goto error;
	184	}
	185
ba17674f LI	186	tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
ba17674f LI	187	n_uname, clnt->dotu);
bd238fb4 LI	188	if (IS_ERR(tc)) {
	189	err = PTR_ERR(tc);
	190	tc = NULL;
	191	goto error;
	192	}
	193
e2735b77	194	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	195	if (err)
	196	goto error;
	197
	198	memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
	199	kfree(tc);
	200	kfree(rc);
	201	return fid;
	202
	203	error:
	204	kfree(tc);
	205	kfree(rc);
	206	if (fid)
	207	p9_fid_destroy(fid);
	208	return ERR_PTR(err);
	209	}
	210	EXPORT_SYMBOL(p9_client_attach);
	211
ba17674f LI	212	struct p9_fid p9_client_auth(struct p9_client clnt, char *uname,
ba17674f LI	213	u32 n_uname, char *aname)
bd238fb4 LI	214	{
	215	int err;
	216	struct p9_fcall tc, rc;
	217	struct p9_fid *fid;
	218
	219	P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
	220	aname);
	221	err = 0;
	222	tc = NULL;
	223	rc = NULL;
	224
	225	fid = p9_fid_create(clnt);
	226	if (IS_ERR(fid)) {
	227	err = PTR_ERR(fid);
	228	fid = NULL;
	229	goto error;
	230	}
	231
ba17674f	232	tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
bd238fb4 LI	233	if (IS_ERR(tc)) {
	234	err = PTR_ERR(tc);
	235	tc = NULL;
	236	goto error;
	237	}
	238
e2735b77	239	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	240	if (err)
	241	goto error;
	242
	243	memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
	244	kfree(tc);
	245	kfree(rc);
	246	return fid;
	247
	248	error:
	249	kfree(tc);
	250	kfree(rc);
	251	if (fid)
	252	p9_fid_destroy(fid);
	253	return ERR_PTR(err);
	254	}
	255	EXPORT_SYMBOL(p9_client_auth);
	256
	257	struct p9_fid p9_client_walk(struct p9_fid oldfid, int nwname, char **wnames,
	258	int clone)
	259	{
	260	int err;
	261	struct p9_fcall tc, rc;
	262	struct p9_client *clnt;
	263	struct p9_fid *fid;
	264
	265	P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
	266	oldfid->fid, nwname, wnames?wnames[0]:NULL);
	267	err = 0;
	268	tc = NULL;
	269	rc = NULL;
	270	clnt = oldfid->clnt;
	271	if (clone) {
	272	fid = p9_fid_create(clnt);
	273	if (IS_ERR(fid)) {
	274	err = PTR_ERR(fid);
	275	fid = NULL;
	276	goto error;
	277	}
	278
	279	fid->uid = oldfid->uid;
	280	} else
	281	fid = oldfid;
	282
	283	tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
	284	if (IS_ERR(tc)) {
	285	err = PTR_ERR(tc);
	286	tc = NULL;
	287	goto error;
	288	}
	289
e2735b77	290	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	291	if (err) {
	292	if (rc && rc->id == P9_RWALK)
	293	goto clunk_fid;
	294	else
	295	goto error;
	296	}
	297
	298	if (rc->params.rwalk.nwqid != nwname) {
	299	err = -ENOENT;
	300	goto clunk_fid;
	301	}
	302
	303	if (nwname)
	304	memmove(&fid->qid,
	305	&rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
	306	sizeof(struct p9_qid));
	307	else
	308	fid->qid = oldfid->qid;
	309
	310	kfree(tc);
	311	kfree(rc);
	312	return fid;
	313
	314	clunk_fid:
	315	kfree(tc);
	316	kfree(rc);
	317	rc = NULL;
	318	tc = p9_create_tclunk(fid->fid);
	319	if (IS_ERR(tc)) {
	320	err = PTR_ERR(tc);
	321	tc = NULL;
	322	goto error;
	323	}
	324
e2735b77	325	p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	326
	327	error:
	328	kfree(tc);
	329	kfree(rc);
	330	if (fid && (fid != oldfid))
	331	p9_fid_destroy(fid);
	332
	333	return ERR_PTR(err);
	334	}
	335	EXPORT_SYMBOL(p9_client_walk);
	336
	337	int p9_client_open(struct p9_fid *fid, int mode)
	338	{
	339	int err;
	340	struct p9_fcall tc, rc;
	341	struct p9_client *clnt;
	342
	343	P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
	344	err = 0;
	345	tc = NULL;
	346	rc = NULL;
	347	clnt = fid->clnt;
	348
	349	if (fid->mode != -1)
	350	return -EINVAL;
	351
	352	tc = p9_create_topen(fid->fid, mode);
	353	if (IS_ERR(tc)) {
	354	err = PTR_ERR(tc);
	355	tc = NULL;
	356	goto done;
	357	}
	358
e2735b77	359	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	360	if (err)
	361	goto done;
	362
	363	fid->mode = mode;
	364	fid->iounit = rc->params.ropen.iounit;
	365
	366	done:
	367	kfree(tc);
	368	kfree(rc);
	369	return err;
	370	}
	371	EXPORT_SYMBOL(p9_client_open);
	372
	373	int p9_client_fcreate(struct p9_fid fid, char name, u32 perm, int mode,
	374	char *extension)
	375	{
	376	int err;
	377	struct p9_fcall tc, rc;
	378	struct p9_client *clnt;
	379
	380	P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
	381	name, perm, mode);
	382	err = 0;
	383	tc = NULL;
	384	rc = NULL;
	385	clnt = fid->clnt;
	386
	387	if (fid->mode != -1)
	388	return -EINVAL;
	389
	390	tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
	391	clnt->dotu);
	392	if (IS_ERR(tc)) {
	393	err = PTR_ERR(tc);
	394	tc = NULL;
	395	goto done;
	396	}
	397
e2735b77	398	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	399	if (err)
	400	goto done;
	401
	402	fid->mode = mode;
	403	fid->iounit = rc->params.ropen.iounit;
	404
	405	done:
	406	kfree(tc);
	407	kfree(rc);
	408	return err;
	409	}
	410	EXPORT_SYMBOL(p9_client_fcreate);
	411
	412	int p9_client_clunk(struct p9_fid *fid)
	413	{
	414	int err;
	415	struct p9_fcall tc, rc;
	416	struct p9_client *clnt;
	417
	418	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	419	err = 0;
	420	tc = NULL;
	421	rc = NULL;
	422	clnt = fid->clnt;
	423
	424	tc = p9_create_tclunk(fid->fid);
	425	if (IS_ERR(tc)) {
	426	err = PTR_ERR(tc);
	427	tc = NULL;
	428	goto done;
	429	}
	430
e2735b77	431	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	432	if (err)
	433	goto done;
	434
	435	p9_fid_destroy(fid);
	436
	437	done:
	438	kfree(tc);
	439	kfree(rc);
	440	return err;
	441	}
	442	EXPORT_SYMBOL(p9_client_clunk);
	443
	444	int p9_client_remove(struct p9_fid *fid)
	445	{
	446	int err;
	447	struct p9_fcall tc, rc;
	448	struct p9_client *clnt;
	449
	450	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	451	err = 0;
	452	tc = NULL;
	453	rc = NULL;
	454	clnt = fid->clnt;
	455
	456	tc = p9_create_tremove(fid->fid);
	457	if (IS_ERR(tc)) {
	458	err = PTR_ERR(tc);
	459	tc = NULL;
	460	goto done;
	461	}
	462
e2735b77	463	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	464	if (err)
	465	goto done;
	466
	467	p9_fid_destroy(fid);
	468
	469	done:
	470	kfree(tc);
	471	kfree(rc);
	472	return err;
	473	}
	474	EXPORT_SYMBOL(p9_client_remove);
	475
	476	int p9_client_read(struct p9_fid fid, char data, u64 offset, u32 count)
	477	{
	478	int err, n, rsize, total;
	479	struct p9_fcall tc, rc;
	480	struct p9_client *clnt;
	481
	482	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
	483	(long long unsigned) offset, count);
	484	err = 0;
	485	tc = NULL;
	486	rc = NULL;
	487	clnt = fid->clnt;
	488	total = 0;
	489
	490	rsize = fid->iounit;
	491	if (!rsize \|\| rsize > clnt->msize-P9_IOHDRSZ)
	492	rsize = clnt->msize - P9_IOHDRSZ;
	493
	494	do {
	495	if (count < rsize)
	496	rsize = count;
	497
	498	tc = p9_create_tread(fid->fid, offset, rsize);
	499	if (IS_ERR(tc)) {
	500	err = PTR_ERR(tc);
	501	tc = NULL;
	502	goto error;
	503	}
	504
e2735b77	505	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	506	if (err)
	507	goto error;
	508
	509	n = rc->params.rread.count;
	510	if (n > count)
	511	n = count;
	512
	513	memmove(data, rc->params.rread.data, n);
	514	count -= n;
	515	data += n;
	516	offset += n;
	517	total += n;
	518	kfree(tc);
	519	tc = NULL;
	520	kfree(rc);
	521	rc = NULL;
	522	} while (count > 0 && n == rsize);
	523
	524	return total;
	525
	526	error:
	527	kfree(tc);
	528	kfree(rc);
	529	return err;
	530	}
	531	EXPORT_SYMBOL(p9_client_read);
	532
	533	int p9_client_write(struct p9_fid fid, char data, u64 offset, u32 count)
	534	{
	535	int err, n, rsize, total;
	536	struct p9_fcall tc, rc;
	537	struct p9_client *clnt;
	538
	539	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
	540	(long long unsigned) offset, count);
	541	err = 0;
	542	tc = NULL;
	543	rc = NULL;
	544	clnt = fid->clnt;
	545	total = 0;
	546
	547	rsize = fid->iounit;
	548	if (!rsize \|\| rsize > clnt->msize-P9_IOHDRSZ)
	549	rsize = clnt->msize - P9_IOHDRSZ;
	550
	551	do {
	552	if (count < rsize)
	553	rsize = count;
	554
	555	tc = p9_create_twrite(fid->fid, offset, rsize, data);
	556	if (IS_ERR(tc)) {
	557	err = PTR_ERR(tc);
	558	tc = NULL;
	559	goto error;
	560	}
	561
e2735b77	562	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	563	if (err)
	564	goto error;
	565
	566	n = rc->params.rread.count;
	567	count -= n;
	568	data += n;
	569	offset += n;
	570	total += n;
	571	kfree(tc);
	572	tc = NULL;
	573	kfree(rc);
	574	rc = NULL;
	575	} while (count > 0);
	576
	577	return total;
	578
	579	error:
	580	kfree(tc);
	581	kfree(rc);
	582	return err;
	583	}
	584	EXPORT_SYMBOL(p9_client_write);
	585
	586	int
	587	p9_client_uread(struct p9_fid fid, char __user data, u64 offset, u32 count)
	588	{
	589	int err, n, rsize, total;
	590	struct p9_fcall tc, rc;
	591	struct p9_client *clnt;
	592
	593	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
	594	(long long unsigned) offset, count);
	595	err = 0;
	596	tc = NULL;
	597	rc = NULL;
	598	clnt = fid->clnt;
	599	total = 0;
	600
	601	rsize = fid->iounit;
	602	if (!rsize \|\| rsize > clnt->msize-P9_IOHDRSZ)
	603	rsize = clnt->msize - P9_IOHDRSZ;
	604
	605	do {
	606	if (count < rsize)
	607	rsize = count;
	608
	609	tc = p9_create_tread(fid->fid, offset, rsize);
	610	if (IS_ERR(tc)) {
	611	err = PTR_ERR(tc);
	612	tc = NULL;
	613	goto error;
	614	}
	615
e2735b77	616	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	617	if (err)
	618	goto error;
	619
	620	n = rc->params.rread.count;
	621	if (n > count)
	622	n = count;
	623
	624	err = copy_to_user(data, rc->params.rread.data, n);
	625	if (err) {
	626	err = -EFAULT;
	627	goto error;
	628	}
	629
	630	count -= n;
	631	data += n;
	632	offset += n;
	633	total += n;
	634	kfree(tc);
	635	tc = NULL;
	636	kfree(rc);
	637	rc = NULL;
	638	} while (count > 0 && n == rsize);
	639
	640	return total;
	641
	642	error:
	643	kfree(tc);
	644	kfree(rc);
	645	return err;
	646	}
	647	EXPORT_SYMBOL(p9_client_uread);
	648
	649	int
	650	p9_client_uwrite(struct p9_fid fid, const char __user data, u64 offset,
	651	u32 count)
	652	{
	653	int err, n, rsize, total;
	654	struct p9_fcall tc, rc;
	655	struct p9_client *clnt;
	656
	657	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
	658	(long long unsigned) offset, count);
	659	err = 0;
	660	tc = NULL;
	661	rc = NULL;
	662	clnt = fid->clnt;
	663	total = 0;
	664
	665	rsize = fid->iounit;
	666	if (!rsize \|\| rsize > clnt->msize-P9_IOHDRSZ)
	667	rsize = clnt->msize - P9_IOHDRSZ;
	668
	669	do {
	670	if (count < rsize)
	671	rsize = count;
	672
	673	tc = p9_create_twrite_u(fid->fid, offset, rsize, data);
	674	if (IS_ERR(tc)) {
	675	err = PTR_ERR(tc);
	676	tc = NULL;
	677	goto error;
	678	}
	679
e2735b77	680	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	681	if (err)
	682	goto error;
	683
	684	n = rc->params.rread.count;
	685	count -= n;
	686	data += n;
	687	offset += n;
	688	total += n;
	689	kfree(tc);
	690	tc = NULL;
	691	kfree(rc);
	692	rc = NULL;
	693	} while (count > 0);
	694
	695	return total;
	696
	697	error:
	698	kfree(tc);
	699	kfree(rc);
	700	return err;
	701	}
	702	EXPORT_SYMBOL(p9_client_uwrite);
	703
	704	int p9_client_readn(struct p9_fid fid, char data, u64 offset, u32 count)
	705	{
	706	int n, total;
	707
	708	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
	709	(long long unsigned) offset, count);
	710	n = 0;
	711	total = 0;
	712	while (count) {
	713	n = p9_client_read(fid, data, offset, count);
	714	if (n <= 0)
	715	break;
	716
	717	data += n;
	718	offset += n;
	719	count -= n;
	720	total += n;
	721	}
	722
	723	if (n < 0)
	724	total = n;
	725
	726	return total;
	727	}
	728	EXPORT_SYMBOL(p9_client_readn);
	729
	730	struct p9_stat p9_client_stat(struct p9_fid fid)
	731	{
	732	int err;
	733	struct p9_fcall tc, rc;
	734	struct p9_client *clnt;
	735	struct p9_stat *ret;
	736
	737	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	738	err = 0;
	739	tc = NULL;
	740	rc = NULL;
	741	ret = NULL;
	742	clnt = fid->clnt;
	743
	744	tc = p9_create_tstat(fid->fid);
745	if (IS_ERR(tc)) {
746	err = PTR_ERR(tc);
747	tc = NULL;
748	goto error;
749	}
750
e2735b77	751	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	752	if (err)
	753	goto error;
	754
	755	ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
	756	if (IS_ERR(ret)) {
	757	err = PTR_ERR(ret);
	758	ret = NULL;
	759	goto error;
	760	}
	761
	762	kfree(tc);
	763	kfree(rc);
	764	return ret;
	765
	766	error:
	767	kfree(tc);
	768	kfree(rc);
	769	kfree(ret);
	770	return ERR_PTR(err);
	771	}
	772	EXPORT_SYMBOL(p9_client_stat);
	773
	774	int p9_client_wstat(struct p9_fid fid, struct p9_wstat wst)
	775	{
	776	int err;
	777	struct p9_fcall tc, rc;
	778	struct p9_client *clnt;
	779
	780	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	781	err = 0;
	782	tc = NULL;
	783	rc = NULL;
	784	clnt = fid->clnt;
	785
	786	tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
	787	if (IS_ERR(tc)) {
	788	err = PTR_ERR(tc);
	789	tc = NULL;
	790	goto done;
	791	}
	792
e2735b77	793	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	794
	795	done:
	796	kfree(tc);
	797	kfree(rc);
	798	return err;
	799	}
	800	EXPORT_SYMBOL(p9_client_wstat);
	801
	802	struct p9_stat p9_client_dirread(struct p9_fid fid, u64 offset)
	803	{
	804	int err, n, m;
	805	struct p9_fcall tc, rc;
	806	struct p9_client *clnt;
	807	struct p9_stat st, *ret;
	808
	809	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu\n", fid->fid,
	810	(long long unsigned) offset);
	811	err = 0;
	812	tc = NULL;
	813	rc = NULL;
	814	ret = NULL;
	815	clnt = fid->clnt;
	816
	817	/* if the offset is below or above the current response, free it */
	818	if (offset < fid->rdir_fpos \|\| (fid->rdir_fcall &&
	819	offset >= fid->rdir_fpos+fid->rdir_fcall->params.rread.count)) {
	820	fid->rdir_pos = 0;
	821	if (fid->rdir_fcall)
	822	fid->rdir_fpos += fid->rdir_fcall->params.rread.count;
	823
	824	kfree(fid->rdir_fcall);
	825	fid->rdir_fcall = NULL;
	826	if (offset < fid->rdir_fpos)
	827	fid->rdir_fpos = 0;
	828	}
	829
	830	if (!fid->rdir_fcall) {
	831	n = fid->iounit;
	832	if (!n \|\| n > clnt->msize-P9_IOHDRSZ)
	833	n = clnt->msize - P9_IOHDRSZ;
	834
	835	while (1) {
	836	if (fid->rdir_fcall) {
	837	fid->rdir_fpos +=
	838	fid->rdir_fcall->params.rread.count;
	839	kfree(fid->rdir_fcall);
	840	fid->rdir_fcall = NULL;
	841	}
	842
	843	tc = p9_create_tread(fid->fid, fid->rdir_fpos, n);
	844	if (IS_ERR(tc)) {
	845	err = PTR_ERR(tc);
	846	tc = NULL;
	847	goto error;
	848	}
	849
e2735b77	850	err = p9_client_rpc(clnt, tc, &rc);
bd238fb4 LI	851	if (err)
	852	goto error;
	853
	854	n = rc->params.rread.count;
	855	if (n == 0)
	856	goto done;
	857
	858	fid->rdir_fcall = rc;
	859	rc = NULL;
	860	if (offset >= fid->rdir_fpos &&
	861	offset < fid->rdir_fpos+n)
	862	break;
	863	}
	864
	865	fid->rdir_pos = 0;
	866	}
	867
	868	m = offset - fid->rdir_fpos;
	869	if (m < 0)
	870	goto done;
	871
	872	n = p9_deserialize_stat(fid->rdir_fcall->params.rread.data + m,
	873	fid->rdir_fcall->params.rread.count - m, &st, clnt->dotu);
	874
	875	if (!n) {
	876	err = -EIO;
	877	goto error;
	878	}
	879
	880	fid->rdir_pos += n;
	881	st.size = n;
	882	ret = p9_clone_stat(&st, clnt->dotu);
	883	if (IS_ERR(ret)) {
	884	err = PTR_ERR(ret);
	885	ret = NULL;
	886	goto error;
	887	}
	888
	889	done:
	890	kfree(tc);
	891	kfree(rc);
	892	return ret;
	893
	894	error:
	895	kfree(tc);
	896	kfree(rc);
	897	kfree(ret);
	898	return ERR_PTR(err);
	899	}
	900	EXPORT_SYMBOL(p9_client_dirread);
	901
	902	static struct p9_stat p9_clone_stat(struct p9_stat st, int dotu)
	903	{
	904	int n;
	905	char *p;
	906	struct p9_stat *ret;
	907
	908	n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
	909	st->muid.len;
	910
	911	if (dotu)
	912	n += st->extension.len;
	913
	914	ret = kmalloc(n, GFP_KERNEL);
915	if (!ret)
916	return ERR_PTR(-ENOMEM);
917
918	memmove(ret, st, sizeof(struct p9_stat));
919	p = ((char *) ret) + sizeof(struct p9_stat);
920	memmove(p, st->name.str, st->name.len);
afcf0c13	921	ret->name.str = p;
bd238fb4 LI	922	p += st->name.len;
bd238fb4 LI	923	memmove(p, st->uid.str, st->uid.len);
afcf0c13	924	ret->uid.str = p;
bd238fb4 LI	925	p += st->uid.len;
bd238fb4 LI	926	memmove(p, st->gid.str, st->gid.len);
afcf0c13	927	ret->gid.str = p;
bd238fb4 LI	928	p += st->gid.len;
bd238fb4 LI	929	memmove(p, st->muid.str, st->muid.len);
afcf0c13	930	ret->muid.str = p;
bd238fb4 LI	931	p += st->muid.len;
	932
	933	if (dotu) {
	934	memmove(p, st->extension.str, st->extension.len);
afcf0c13	935	ret->extension.str = p;
bd238fb4 LI	936	p += st->extension.len;
	937	}
	938
	939	return ret;
	940	}
	941
	942	static struct p9_fid p9_fid_create(struct p9_client clnt)
	943	{
	944	int err;
	945	struct p9_fid *fid;
	946
	947	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
	948	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
	949	if (!fid)
	950	return ERR_PTR(-ENOMEM);
	951
	952	fid->fid = p9_idpool_get(clnt->fidpool);
	953	if (fid->fid < 0) {
	954	err = -ENOSPC;
	955	goto error;
	956	}
	957
	958	memset(&fid->qid, 0, sizeof(struct p9_qid));
	959	fid->mode = -1;
	960	fid->rdir_fpos = 0;
	961	fid->rdir_pos = 0;
	962	fid->rdir_fcall = NULL;
	963	fid->uid = current->fsuid;
	964	fid->clnt = clnt;
	965	fid->aux = NULL;
	966
	967	spin_lock(&clnt->lock);
	968	list_add(&fid->flist, &clnt->fidlist);
	969	spin_unlock(&clnt->lock);
	970
	971	return fid;
	972
	973	error:
	974	kfree(fid);
	975	return ERR_PTR(err);
	976	}
	977
	978	static void p9_fid_destroy(struct p9_fid *fid)
	979	{
	980	struct p9_client *clnt;
	981
	982	P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
	983	clnt = fid->clnt;
	984	p9_idpool_put(fid->fid, clnt->fidpool);
	985	spin_lock(&clnt->lock);
	986	list_del(&fid->flist);
	987	spin_unlock(&clnt->lock);
	988	kfree(fid->rdir_fcall);
	989	kfree(fid);
	990	}