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, 363 insertions, 0 deletions

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
new file mode 100644
index 000000000000..fd636e94358f
--- /dev/null
+++ b/net/9p/trans_fd.c
@@ -0,0 +1,363 @@
+/*
+ * linux/fs/9p/trans_fd.c
+ *
+ * Fd transport layer.  Includes deprecated socket layer.
+ *
+ *  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) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/in.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/ipv6.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/un.h>
+#include <linux/uaccess.h>
+#include <linux/inet.h>
+#include <linux/idr.h>
+#include <linux/file.h>
+#include <net/9p/9p.h>
+#include <net/9p/transport.h>
+
+#define P9_PORT 564
+
+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;
+
+        return trans;
+
+error:
+        if (csocket)
+                sock_release(csocket);
+
+        kfree(trans);
+        return ERR_PTR(err);
+}
+EXPORT_SYMBOL(p9_trans_create_tcp);
+
+struct p9_transport *p9_trans_create_unix(const char *addr)
+{
+        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);
+
+        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);
+}
+EXPORT_SYMBOL(p9_trans_create_unix);
+
+struct p9_transport *p9_trans_create_fd(int rfd, int wfd)
+{
+        int err;
+        struct p9_transport *trans;
+
+        if (rfd == ~0 || wfd == ~0) {
+                printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
+                return ERR_PTR(-ENOPROTOOPT);
+        }
+
+        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;
+
+error:
+        kfree(trans);
+        return ERR_PTR(err);
+}
+EXPORT_SYMBOL(p9_trans_create_fd);
+
+static int p9_socket_open(struct p9_transport *trans, struct socket *csocket)
+{
+        int fd, ret;
+
+        csocket->sk->sk_allocation = GFP_NOIO;
+        fd = sock_map_fd(csocket);
+        if (fd < 0) {
+                P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
+                return fd;
+        }
+
+        ret = p9_fd_open(trans, fd, fd);
+        if (ret < 0) {
+                P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
+                sockfd_put(csocket);
+                return ret;
+        }
+
+        ((struct p9_trans_fd *)trans->priv)->rd->f_flags |= O_NONBLOCK;
+
+        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
+ * @v: buffer to receive data into
+ * @len: size of receive buffer
+ *
+ */
+static int p9_fd_read(struct p9_transport *trans, void *v, int len)
+{
+        int ret;
+        struct p9_trans_fd *ts = NULL;
+
+        if (trans && trans->status != Disconnected)
+                ts = trans->priv;
+
+        if (!ts)
+                return -EREMOTEIO;
+
+        if (!(ts->rd->f_flags & O_NONBLOCK))
+                P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
+
+        ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
+        if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
+                trans->status = Disconnected;
+        return ret;
+}
+
+/**
+ * p9_fd_write - write to a socket
+ * @v9ses: session information
+ * @v: buffer to send data from
+ * @len: size of send buffer
+ *
+ */
+static int p9_fd_write(struct p9_transport *trans, void *v, int len)
+{
+        int ret;
+        mm_segment_t oldfs;
+        struct p9_trans_fd *ts = NULL;
+
+        if (trans && trans->status != Disconnected)
+                ts = trans->priv;
+
+        if (!ts)
+                return -EREMOTEIO;
+
+        if (!(ts->wr->f_flags & O_NONBLOCK))
+                P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
+
+        oldfs = get_fs();
+        set_fs(get_ds());
+        /* The cast to a user pointer is valid due to the set_fs() */
+        ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
+        set_fs(oldfs);
+
+        if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
+                trans->status = Disconnected;
+        return ret;
+}
+
+static unsigned int
+p9_fd_poll(struct p9_transport *trans, struct poll_table_struct *pt)
+{
+        int ret, n;
+        struct p9_trans_fd *ts = NULL;
+        mm_segment_t oldfs;
+
+        if (trans && trans->status == Connected)
+                ts = trans->priv;
+
+        if (!ts)
+                return -EREMOTEIO;
+
+        if (!ts->rd->f_op || !ts->rd->f_op->poll)
+                return -EIO;
+
+        if (!ts->wr->f_op || !ts->wr->f_op->poll)
+                return -EIO;
+
+        oldfs = get_fs();
+        set_fs(get_ds());
+
+        ret = ts->rd->f_op->poll(ts->rd, pt);
+        if (ret < 0)
+                goto end;
+
+        if (ts->rd != ts->wr) {
+                n = ts->wr->f_op->poll(ts->wr, pt);
+                if (n < 0) {
+                        ret = n;
+                        goto end;
+                }
+                ret = (ret & ~POLLOUT) | (n & ~POLLIN);
+        }
+
+end:
+        set_fs(oldfs);
+        return ret;
+}
+
+/**
+ * p9_sock_close - shutdown socket
+ * @trans: private socket structure
+ *
+ */
+static void p9_fd_close(struct p9_transport *trans)
+{
+        struct p9_trans_fd *ts;
+
+        if (!trans)
+                return;
+
+        ts = xchg(&trans->priv, NULL);
+
+        if (!ts)
+                return;
+
+        trans->status = Disconnected;
+        if (ts->rd)
+                fput(ts->rd);
+        if (ts->wr)
+                fput(ts->wr);
+        kfree(ts);
+}
+