ipv6: fix an oops when force unload ipv6 module
[safe/jmp/linux-2.6] / net / 9p / trans_fd.c
index f6d4af1..4dd873e 100644 (file)
 #include <linux/file.h>
 #include <linux/parser.h>
 #include <net/9p/9p.h>
+#include <net/9p/client.h>
 #include <net/9p/transport.h>
 
 #define P9_PORT 564
 #define MAX_SOCK_BUF (64*1024)
-#define ERREQFLUSH     1
-#define SCHED_TIMEOUT  10
 #define MAXPOLLWADDR   2
 
 /**
@@ -61,7 +60,6 @@ struct p9_fd_opts {
        u16 port;
 };
 
-
 /**
  * struct p9_trans_fd - transport state
  * @rd: reference to file to read from
@@ -86,7 +84,7 @@ enum {
        Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
 };
 
-static match_table_t tokens = {
+static const match_table_t tokens = {
        {Opt_port, "port=%u"},
        {Opt_rfdno, "rfdno=%u"},
        {Opt_wfdno, "wfdno=%u"},
@@ -100,67 +98,29 @@ enum {
        Wpending = 8,           /* can write */
 };
 
-enum {
-       None,
-       Flushing,
-       Flushed,
-};
-
-struct p9_req;
-typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
-
-/**
- * struct p9_req - fd mux encoding of an rpc transaction
- * @lock: protects req_list
- * @tag: numeric tag for rpc transaction
- * @tcall: request &p9_fcall structure
- * @rcall: response &p9_fcall structure
- * @err: error state
- * @cb: callback for when response is received
- * @cba: argument to pass to callback
- * @flush: flag to indicate RPC has been flushed
- * @req_list: list link for higher level objects to chain requests
- *
- */
-
-struct p9_req {
-       spinlock_t lock;
-       int tag;
-       struct p9_fcall *tcall;
-       struct p9_fcall *rcall;
-       int err;
-       p9_conn_req_callback cb;
-       void *cba;
-       int flush;
-       struct list_head req_list;
-};
-
-struct p9_mux_poll_task {
-       struct task_struct *task;
-       struct list_head mux_list;
-       int muxnum;
+struct p9_poll_wait {
+       struct p9_conn *conn;
+       wait_queue_t wait;
+       wait_queue_head_t *wait_addr;
 };
 
 /**
  * struct p9_conn - fd mux connection state information
- * @lock: protects mux_list (?)
  * @mux_list: list link for mux to manage multiple connections (?)
- * @poll_task: task polling on this connection
- * @msize: maximum size for connection (dup)
- * @extended: 9p2000.u flag (dup)
- * @trans: reference to transport instance for this connection
- * @tagpool: id accounting for transactions
+ * @client: reference to client instance for this connection
  * @err: error state
  * @req_list: accounting for requests which have been sent
  * @unsent_req_list: accounting for requests that haven't been sent
- * @rcall: current response &p9_fcall structure
+ * @req: current request being processed (if any)
+ * @tmp_buf: temporary buffer to read in header
+ * @rsize: amount to read for current frame
  * @rpos: read position in current frame
  * @rbuf: current read buffer
  * @wpos: write position for current frame
  * @wsize: amount of data to write for current frame
  * @wbuf: current write buffer
+ * @poll_pending_link: pending links to be polled per conn
  * @poll_wait: array of wait_q's for various worker threads
- * @poll_waddr: ????
  * @pt: poll state
  * @rq: current read work
  * @wq: current write work
@@ -169,425 +129,302 @@ struct p9_mux_poll_task {
  */
 
 struct p9_conn {
-       spinlock_t lock; /* protect lock structure */
        struct list_head mux_list;
-       struct p9_mux_poll_task *poll_task;
-       int msize;
-       unsigned char extended;
-       struct p9_trans *trans;
-       struct p9_idpool *tagpool;
+       struct p9_client *client;
        int err;
        struct list_head req_list;
        struct list_head unsent_req_list;
-       struct p9_fcall *rcall;
+       struct p9_req_t *req;
+       char tmp_buf[7];
+       int rsize;
        int rpos;
        char *rbuf;
        int wpos;
        int wsize;
        char *wbuf;
-       wait_queue_t poll_wait[MAXPOLLWADDR];
-       wait_queue_head_t *poll_waddr[MAXPOLLWADDR];
+       struct list_head poll_pending_link;
+       struct p9_poll_wait poll_wait[MAXPOLLWADDR];
        poll_table pt;
        struct work_struct rq;
        struct work_struct wq;
        unsigned long wsched;
 };
 
-/**
- * struct p9_mux_rpc - fd mux rpc accounting structure
- * @m: connection this request was issued on
- * @err: error state
- * @tcall: request &p9_fcall
- * @rcall: response &p9_fcall
- * @wqueue: wait queue that client is blocked on for this rpc
- *
- * Bug: isn't this information duplicated elsewhere like &p9_req
- */
-
-struct p9_mux_rpc {
-       struct p9_conn *m;
-       int err;
-       struct p9_fcall *tcall;
-       struct p9_fcall *rcall;
-       wait_queue_head_t wqueue;
-};
-
-static int p9_poll_proc(void *);
-static void p9_read_work(struct work_struct *work);
-static void p9_write_work(struct work_struct *work);
-static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address,
-                                                               poll_table *p);
-static int p9_fd_write(struct p9_trans *trans, void *v, int len);
-static int p9_fd_read(struct p9_trans *trans, void *v, int len);
-
-static DEFINE_MUTEX(p9_mux_task_lock);
+static DEFINE_SPINLOCK(p9_poll_lock);
+static LIST_HEAD(p9_poll_pending_list);
 static struct workqueue_struct *p9_mux_wq;
+static struct task_struct *p9_poll_task;
 
-static int p9_mux_num;
-static int p9_mux_poll_task_num;
-static struct p9_mux_poll_task p9_mux_poll_tasks[100];
-
-static void p9_conn_destroy(struct p9_conn *);
-static unsigned int p9_fd_poll(struct p9_trans *trans,
-                                               struct poll_table_struct *pt);
-
-#ifdef P9_NONBLOCK
-static int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
-       p9_conn_req_callback cb, void *a);
-#endif /* P9_NONBLOCK */
-
-static void p9_conn_cancel(struct p9_conn *m, int err);
-
-static int p9_mux_global_init(void)
+static void p9_mux_poll_stop(struct p9_conn *m)
 {
+       unsigned long flags;
        int i;
 
-       for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++)
-               p9_mux_poll_tasks[i].task = NULL;
+       for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
+               struct p9_poll_wait *pwait = &m->poll_wait[i];
 
-       p9_mux_wq = create_workqueue("v9fs");
-       if (!p9_mux_wq) {
-               printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
-               return -ENOMEM;
+               if (pwait->wait_addr) {
+                       remove_wait_queue(pwait->wait_addr, &pwait->wait);
+                       pwait->wait_addr = NULL;
+               }
        }
 
-       return 0;
-}
-
-static u16 p9_mux_get_tag(struct p9_conn *m)
-{
-       int tag;
-
-       tag = p9_idpool_get(m->tagpool);
-       if (tag < 0)
-               return P9_NOTAG;
-       else
-               return (u16) tag;
-}
-
-static void p9_mux_put_tag(struct p9_conn *m, u16 tag)
-{
-       if (tag != P9_NOTAG && p9_idpool_check(tag, m->tagpool))
-               p9_idpool_put(tag, m->tagpool);
+       spin_lock_irqsave(&p9_poll_lock, flags);
+       list_del_init(&m->poll_pending_link);
+       spin_unlock_irqrestore(&p9_poll_lock, flags);
 }
 
 /**
- * p9_mux_calc_poll_procs - calculates the number of polling procs
- * @muxnum: number of mounts
+ * p9_conn_cancel - cancel all pending requests with error
+ * @m: mux data
+ * @err: error code
  *
- * Calculation is based on the number of mounted v9fs filesystems.
- * The current implementation returns sqrt of the number of mounts.
  */
 
-static int p9_mux_calc_poll_procs(int muxnum)
+static void p9_conn_cancel(struct p9_conn *m, int err)
 {
-       int n;
+       struct p9_req_t *req, *rtmp;
+       unsigned long flags;
+       LIST_HEAD(cancel_list);
 
-       if (p9_mux_poll_task_num)
-               n = muxnum / p9_mux_poll_task_num +
-                   (muxnum % p9_mux_poll_task_num ? 1 : 0);
-       else
-               n = 1;
+       P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
 
-       if (n > ARRAY_SIZE(p9_mux_poll_tasks))
-               n = ARRAY_SIZE(p9_mux_poll_tasks);
+       spin_lock_irqsave(&m->client->lock, flags);
 
-       return n;
-}
+       if (m->err) {
+               spin_unlock_irqrestore(&m->client->lock, flags);
+               return;
+       }
 
-static int p9_mux_poll_start(struct p9_conn *m)
-{
-       int i, n;
-       struct p9_mux_poll_task *vpt, *vptlast;
-       struct task_struct *pproc;
-
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, p9_mux_num,
-               p9_mux_poll_task_num);
-       mutex_lock(&p9_mux_task_lock);
-
-       n = p9_mux_calc_poll_procs(p9_mux_num + 1);
-       if (n > p9_mux_poll_task_num) {
-               for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
-                       if (p9_mux_poll_tasks[i].task == NULL) {
-                               vpt = &p9_mux_poll_tasks[i];
-                               P9_DPRINTK(P9_DEBUG_MUX, "create proc %p\n",
-                                                                       vpt);
-                               pproc = kthread_create(p9_poll_proc, vpt,
-                                                               "v9fs-poll");
-
-                               if (!IS_ERR(pproc)) {
-                                       vpt->task = pproc;
-                                       INIT_LIST_HEAD(&vpt->mux_list);
-                                       vpt->muxnum = 0;
-                                       p9_mux_poll_task_num++;
-                                       wake_up_process(vpt->task);
-                               }
-                               break;
-                       }
-               }
+       m->err = err;
 
-               if (i >= ARRAY_SIZE(p9_mux_poll_tasks))
-                       P9_DPRINTK(P9_DEBUG_ERROR,
-                                       "warning: no free poll slots\n");
+       list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
+               req->status = REQ_STATUS_ERROR;
+               if (!req->t_err)
+                       req->t_err = err;
+               list_move(&req->req_list, &cancel_list);
        }
-
-       n = (p9_mux_num + 1) / p9_mux_poll_task_num +
-           ((p9_mux_num + 1) % p9_mux_poll_task_num ? 1 : 0);
-
-       vptlast = NULL;
-       for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
-               vpt = &p9_mux_poll_tasks[i];
-               if (vpt->task != NULL) {
-                       vptlast = vpt;
-                       if (vpt->muxnum < n) {
-                               P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
-                               list_add(&m->mux_list, &vpt->mux_list);
-                               vpt->muxnum++;
-                               m->poll_task = vpt;
-                               memset(&m->poll_waddr, 0,
-                                                       sizeof(m->poll_waddr));
-                               init_poll_funcptr(&m->pt, p9_pollwait);
-                               break;
-                       }
-               }
+       list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
+               req->status = REQ_STATUS_ERROR;
+               if (!req->t_err)
+                       req->t_err = err;
+               list_move(&req->req_list, &cancel_list);
        }
+       spin_unlock_irqrestore(&m->client->lock, flags);
 
-       if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) {
-               if (vptlast == NULL) {
-                       mutex_unlock(&p9_mux_task_lock);
-                       return -ENOMEM;
-               }
-
-               P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
-               list_add(&m->mux_list, &vptlast->mux_list);
-               vptlast->muxnum++;
-               m->poll_task = vptlast;
-               memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
-               init_poll_funcptr(&m->pt, p9_pollwait);
+       list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
+               P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
+               list_del(&req->req_list);
+               p9_client_cb(m->client, req);
        }
-
-       p9_mux_num++;
-       mutex_unlock(&p9_mux_task_lock);
-
-       return 0;
 }
 
-static void p9_mux_poll_stop(struct p9_conn *m)
+static unsigned int
+p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
 {
-       int i;
-       struct p9_mux_poll_task *vpt;
-
-       mutex_lock(&p9_mux_task_lock);
-       vpt = m->poll_task;
-       list_del(&m->mux_list);
-       for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
-               if (m->poll_waddr[i] != NULL) {
-                       remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]);
-                       m->poll_waddr[i] = NULL;
-               }
-       }
-       vpt->muxnum--;
-       if (!vpt->muxnum) {
-               P9_DPRINTK(P9_DEBUG_MUX, "destroy proc %p\n", vpt);
-               kthread_stop(vpt->task);
-               vpt->task = NULL;
-               p9_mux_poll_task_num--;
-       }
-       p9_mux_num--;
-       mutex_unlock(&p9_mux_task_lock);
-}
-
-/**
- * p9_conn_create - allocate and initialize the per-session mux data
- * @trans: transport structure
- *
- * Note: Creates the polling task if this is the first session.
- */
+       int ret, n;
+       struct p9_trans_fd *ts = NULL;
 
-static struct p9_conn *p9_conn_create(struct p9_trans *trans)
-{
-       int i, n;
-       struct p9_conn *m;
+       if (client && client->status == Connected)
+               ts = client->trans;
 
-       P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans,
-                                                               trans->msize);
-       m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
-       if (!m)
-               return ERR_PTR(-ENOMEM);
-
-       spin_lock_init(&m->lock);
-       INIT_LIST_HEAD(&m->mux_list);
-       m->msize = trans->msize;
-       m->extended = trans->extended;
-       m->trans = trans;
-       m->tagpool = p9_idpool_create();
-       if (IS_ERR(m->tagpool)) {
-               kfree(m);
-               return ERR_PTR(-ENOMEM);
-       }
+       if (!ts)
+               return -EREMOTEIO;
 
-       INIT_LIST_HEAD(&m->req_list);
-       INIT_LIST_HEAD(&m->unsent_req_list);
-       INIT_WORK(&m->rq, p9_read_work);
-       INIT_WORK(&m->wq, p9_write_work);
-       n = p9_mux_poll_start(m);
-       if (n) {
-               kfree(m);
-               return ERR_PTR(n);
-       }
+       if (!ts->rd->f_op || !ts->rd->f_op->poll)
+               return -EIO;
 
-       n = p9_fd_poll(trans, &m->pt);
-       if (n & POLLIN) {
-               P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
-               set_bit(Rpending, &m->wsched);
-       }
+       if (!ts->wr->f_op || !ts->wr->f_op->poll)
+               return -EIO;
 
-       if (n & POLLOUT) {
-               P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
-               set_bit(Wpending, &m->wsched);
-       }
+       ret = ts->rd->f_op->poll(ts->rd, pt);
+       if (ret < 0)
+               return ret;
 
-       for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
-               if (IS_ERR(m->poll_waddr[i])) {
-                       p9_mux_poll_stop(m);
-                       kfree(m);
-                       return (void *)m->poll_waddr;   /* the error code */
-               }
+       if (ts->rd != ts->wr) {
+               n = ts->wr->f_op->poll(ts->wr, pt);
+               if (n < 0)
+                       return n;
+               ret = (ret & ~POLLOUT) | (n & ~POLLIN);
        }
 
-       return m;
+       return ret;
 }
 
 /**
- * p9_mux_destroy - cancels all pending requests and frees mux resources
- * @m: mux to destroy
+ * p9_fd_read- read from a fd
+ * @client: client instance
+ * @v: buffer to receive data into
+ * @len: size of receive buffer
  *
  */
 
-static void p9_conn_destroy(struct p9_conn *m)
+static int p9_fd_read(struct p9_client *client, void *v, int len)
 {
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
-               m->mux_list.prev, m->mux_list.next);
+       int ret;
+       struct p9_trans_fd *ts = NULL;
 
-       p9_mux_poll_stop(m);
-       cancel_work_sync(&m->rq);
-       cancel_work_sync(&m->wq);
+       if (client && client->status != Disconnected)
+               ts = client->trans;
 
-       p9_conn_cancel(m, -ECONNRESET);
+       if (!ts)
+               return -EREMOTEIO;
 
-       m->trans = NULL;
-       p9_idpool_destroy(m->tagpool);
-       kfree(m);
+       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)
+               client->status = Disconnected;
+       return ret;
 }
 
 /**
- * p9_pollwait - add poll task to the wait queue
- * @filp: file pointer being polled
- * @wait_address: wait_q to block on
- * @p: poll state
+ * p9_read_work - called when there is some data to be read from a transport
+ * @work: container of work to be done
  *
- * called by files poll operation to add v9fs-poll task to files wait queue
  */
 
-static void
-p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
+static void p9_read_work(struct work_struct *work)
 {
-       int i;
+       int n, err;
        struct p9_conn *m;
 
-       m = container_of(p, struct p9_conn, pt);
-       for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++)
-               if (m->poll_waddr[i] == NULL)
-                       break;
+       m = container_of(work, struct p9_conn, rq);
 
-       if (i >= ARRAY_SIZE(m->poll_waddr)) {
-               P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
+       if (m->err < 0)
                return;
-       }
 
-       m->poll_waddr[i] = wait_address;
+       P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
 
-       if (!wait_address) {
-               P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
-               m->poll_waddr[i] = ERR_PTR(-EIO);
+       if (!m->rbuf) {
+               m->rbuf = m->tmp_buf;
+               m->rpos = 0;
+               m->rsize = 7; /* start by reading header */
+       }
+
+       clear_bit(Rpending, &m->wsched);
+       P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
+                                       m->rpos, m->rsize, m->rsize-m->rpos);
+       err = p9_fd_read(m->client, m->rbuf + m->rpos,
+                                               m->rsize - m->rpos);
+       P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
+       if (err == -EAGAIN) {
+               clear_bit(Rworksched, &m->wsched);
                return;
        }
 
-       init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
-       add_wait_queue(wait_address, &m->poll_wait[i]);
-}
+       if (err <= 0)
+               goto error;
 
-/**
- * p9_poll_mux - polls a mux and schedules read or write works if necessary
- * @m: connection to poll
- *
- */
+       m->rpos += err;
 
-static void p9_poll_mux(struct p9_conn *m)
-{
-       int n;
+       if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
+               u16 tag;
+               P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
 
-       if (m->err < 0)
-               return;
+               n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
+               if (n >= m->client->msize) {
+                       P9_DPRINTK(P9_DEBUG_ERROR,
+                               "requested packet size too big: %d\n", n);
+                       err = -EIO;
+                       goto error;
+               }
 
-       n = p9_fd_poll(m->trans, NULL);
-       if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
-               P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n);
-               if (n >= 0)
-                       n = -ECONNRESET;
-               p9_conn_cancel(m, n);
-       }
+               tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
+               P9_DPRINTK(P9_DEBUG_TRANS,
+                       "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
 
-       if (n & POLLIN) {
-               set_bit(Rpending, &m->wsched);
-               P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
-               if (!test_and_set_bit(Rworksched, &m->wsched)) {
-                       P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
-                       queue_work(p9_mux_wq, &m->rq);
+               m->req = p9_tag_lookup(m->client, tag);
+               if (!m->req || (m->req->status != REQ_STATUS_SENT &&
+                                       m->req->status != REQ_STATUS_FLSH)) {
+                       P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
+                                                                tag);
+                       err = -EIO;
+                       goto error;
                }
-       }
 
-       if (n & POLLOUT) {
-               set_bit(Wpending, &m->wsched);
-               P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
-               if ((m->wsize || !list_empty(&m->unsent_req_list))
-                   && !test_and_set_bit(Wworksched, &m->wsched)) {
-                       P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
-                       queue_work(p9_mux_wq, &m->wq);
+               if (m->req->rc == NULL) {
+                       m->req->rc = kmalloc(sizeof(struct p9_fcall) +
+                                               m->client->msize, GFP_KERNEL);
+                       if (!m->req->rc) {
+                               m->req = NULL;
+                               err = -ENOMEM;
+                               goto error;
+                       }
                }
+               m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
+               memcpy(m->rbuf, m->tmp_buf, m->rsize);
+               m->rsize = n;
+       }
+
+       /* not an else because some packets (like clunk) have no payload */
+       if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
+               P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
+               spin_lock(&m->client->lock);
+               if (m->req->status != REQ_STATUS_ERROR)
+                       m->req->status = REQ_STATUS_RCVD;
+               list_del(&m->req->req_list);
+               spin_unlock(&m->client->lock);
+               p9_client_cb(m->client, m->req);
+               m->rbuf = NULL;
+               m->rpos = 0;
+               m->rsize = 0;
+               m->req = NULL;
        }
+
+       if (!list_empty(&m->req_list)) {
+               if (test_and_clear_bit(Rpending, &m->wsched))
+                       n = POLLIN;
+               else
+                       n = p9_fd_poll(m->client, NULL);
+
+               if (n & POLLIN) {
+                       P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
+                       queue_work(p9_mux_wq, &m->rq);
+               } else
+                       clear_bit(Rworksched, &m->wsched);
+       } else
+               clear_bit(Rworksched, &m->wsched);
+
+       return;
+error:
+       p9_conn_cancel(m, err);
+       clear_bit(Rworksched, &m->wsched);
 }
 
 /**
- * p9_poll_proc - poll worker thread
- * @a: thread state and arguments
- *
- * polls all v9fs transports for new events and queues the appropriate
- * work to the work queue
+ * p9_fd_write - write to a socket
+ * @client: client instance
+ * @v: buffer to send data from
+ * @len: size of send buffer
  *
  */
 
-static int p9_poll_proc(void *a)
+static int p9_fd_write(struct p9_client *client, void *v, int len)
 {
-       struct p9_conn *m, *mtmp;
-       struct p9_mux_poll_task *vpt;
+       int ret;
+       mm_segment_t oldfs;
+       struct p9_trans_fd *ts = NULL;
 
-       vpt = a;
-       P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt);
-       while (!kthread_should_stop()) {
-               set_current_state(TASK_INTERRUPTIBLE);
+       if (client && client->status != Disconnected)
+               ts = client->trans;
 
-               list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
-                       p9_poll_mux(m);
-               }
+       if (!ts)
+               return -EREMOTEIO;
 
-               P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
-               schedule_timeout(SCHED_TIMEOUT * HZ);
-       }
+       if (!(ts->wr->f_flags & O_NONBLOCK))
+               P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
 
-       __set_current_state(TASK_RUNNING);
-       P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
-       return 0;
+       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, (__force void __user *)v, len, &ts->wr->f_pos);
+       set_fs(oldfs);
+
+       if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
+               client->status = Disconnected;
+       return ret;
 }
 
 /**
@@ -600,7 +437,7 @@ static void p9_write_work(struct work_struct *work)
 {
        int n, err;
        struct p9_conn *m;
-       struct p9_req *req;
+       struct p9_req_t *req;
 
        m = container_of(work, struct p9_conn, wq);
 
@@ -615,25 +452,24 @@ static void p9_write_work(struct work_struct *work)
                        return;
                }
 
-               spin_lock(&m->lock);
-again:
-               req = list_entry(m->unsent_req_list.next, struct p9_req,
+               spin_lock(&m->client->lock);
+               req = list_entry(m->unsent_req_list.next, struct p9_req_t,
                               req_list);
+               req->status = REQ_STATUS_SENT;
+               P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
                list_move_tail(&req->req_list, &m->req_list);
-               if (req->err == ERREQFLUSH)
-                       goto again;
 
-               m->wbuf = req->tcall->sdata;
-               m->wsize = req->tcall->size;
+               m->wbuf = req->tc->sdata;
+               m->wsize = req->tc->size;
                m->wpos = 0;
-               spin_unlock(&m->lock);
+               spin_unlock(&m->client->lock);
        }
 
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
+       P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
                                                                m->wsize);
        clear_bit(Wpending, &m->wsched);
-       err = p9_fd_write(m->trans, m->wbuf + m->wpos, m->wsize - m->wpos);
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
+       err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
+       P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
        if (err == -EAGAIN) {
                clear_bit(Wworksched, &m->wsched);
                return;
@@ -654,10 +490,10 @@ again:
                if (test_and_clear_bit(Wpending, &m->wsched))
                        n = POLLOUT;
                else
-                       n = p9_fd_poll(m->trans, NULL);
+                       n = p9_fd_poll(m->client, NULL);
 
                if (n & POLLOUT) {
-                       P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
+                       P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
                        queue_work(p9_mux_wq, &m->wq);
                } else
                        clear_bit(Wworksched, &m->wsched);
@@ -671,508 +507,202 @@ error:
        clear_bit(Wworksched, &m->wsched);
 }
 
-static void process_request(struct p9_conn *m, struct p9_req *req)
-{
-       int ecode;
-       struct p9_str *ename;
-
-       if (!req->err && req->rcall->id == P9_RERROR) {
-               ecode = req->rcall->params.rerror.errno;
-               ename = &req->rcall->params.rerror.error;
-
-               P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
-                                                               ename->str);
-
-               if (m->extended)
-                       req->err = -ecode;
-
-               if (!req->err) {
-                       req->err = p9_errstr2errno(ename->str, ename->len);
-
-                       /* string match failed */
-                       if (!req->err) {
-                               PRINT_FCALL_ERROR("unknown error", req->rcall);
-                               req->err = -ESERVERFAULT;
-                       }
-               }
-       } else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
-               P9_DPRINTK(P9_DEBUG_ERROR,
-                               "fcall mismatch: expected %d, got %d\n",
-                               req->tcall->id + 1, req->rcall->id);
-               if (!req->err)
-                       req->err = -EIO;
-       }
-}
-
-/**
- * p9_read_work - called when there is some data to be read from a transport
- * @work: container of work to be done
- *
- */
-
-static void p9_read_work(struct work_struct *work)
-{
-       int n, err;
-       struct p9_conn *m;
-       struct p9_req *req, *rptr, *rreq;
-       struct p9_fcall *rcall;
-       char *rbuf;
-
-       m = container_of(work, struct p9_conn, rq);
-
-       if (m->err < 0)
-               return;
-
-       rcall = NULL;
-       P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
-
-       if (!m->rcall) {
-               m->rcall =
-                   kmalloc(sizeof(struct p9_fcall) + m->msize, GFP_KERNEL);
-               if (!m->rcall) {
-                       err = -ENOMEM;
-                       goto error;
-               }
-
-               m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
-               m->rpos = 0;
-       }
-
-       clear_bit(Rpending, &m->wsched);
-       err = p9_fd_read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos);
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
-       if (err == -EAGAIN) {
-               clear_bit(Rworksched, &m->wsched);
-               return;
-       }
-
-       if (err <= 0)
-               goto error;
-
-       m->rpos += err;
-       while (m->rpos > 4) {
-               n = le32_to_cpu(*(__le32 *) m->rbuf);
-               if (n >= m->msize) {
-                       P9_DPRINTK(P9_DEBUG_ERROR,
-                               "requested packet size too big: %d\n", n);
-                       err = -EIO;
-                       goto error;
-               }
-
-               if (m->rpos < n)
-                       break;
-
-               err =
-                   p9_deserialize_fcall(m->rbuf, n, m->rcall, m->extended);
-               if (err < 0)
-                       goto error;
-
-#ifdef CONFIG_NET_9P_DEBUG
-               if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
-                       char buf[150];
-
-                       p9_printfcall(buf, sizeof(buf), m->rcall,
-                               m->extended);
-                       printk(KERN_NOTICE ">>> %p %s\n", m, buf);
-               }
-#endif
-
-               rcall = m->rcall;
-               rbuf = m->rbuf;
-               if (m->rpos > n) {
-                       m->rcall = kmalloc(sizeof(struct p9_fcall) + m->msize,
-                                          GFP_KERNEL);
-                       if (!m->rcall) {
-                               err = -ENOMEM;
-                               goto error;
-                       }
-
-                       m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
-                       memmove(m->rbuf, rbuf + n, m->rpos - n);
-                       m->rpos -= n;
-               } else {
-                       m->rcall = NULL;
-                       m->rbuf = NULL;
-                       m->rpos = 0;
-               }
-
-               P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
-                                                       rcall->id, rcall->tag);
-
-               req = NULL;
-               spin_lock(&m->lock);
-               list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
-                       if (rreq->tag == rcall->tag) {
-                               req = rreq;
-                               if (req->flush != Flushing)
-                                       list_del(&req->req_list);
-                               break;
-                       }
-               }
-               spin_unlock(&m->lock);
-
-               if (req) {
-                       req->rcall = rcall;
-                       process_request(m, req);
-
-                       if (req->flush != Flushing) {
-                               if (req->cb)
-                                       (*req->cb) (req, req->cba);
-                               else
-                                       kfree(req->rcall);
-                       }
-               } else {
-                       if (err >= 0 && rcall->id != P9_RFLUSH)
-                               P9_DPRINTK(P9_DEBUG_ERROR,
-                                 "unexpected response mux %p id %d tag %d\n",
-                                 m, rcall->id, rcall->tag);
-                       kfree(rcall);
-               }
-       }
-
-       if (!list_empty(&m->req_list)) {
-               if (test_and_clear_bit(Rpending, &m->wsched))
-                       n = POLLIN;
-               else
-                       n = p9_fd_poll(m->trans, NULL);
-
-               if (n & POLLIN) {
-                       P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
-                       queue_work(p9_mux_wq, &m->rq);
-               } else
-                       clear_bit(Rworksched, &m->wsched);
-       } else
-               clear_bit(Rworksched, &m->wsched);
-
-       return;
-
-error:
-       p9_conn_cancel(m, err);
-       clear_bit(Rworksched, &m->wsched);
-}
-
-/**
- * p9_send_request - send 9P request
- * The function can sleep until the request is scheduled for sending.
- * The function can be interrupted. Return from the function is not
- * a guarantee that the request is sent successfully. Can return errors
- * that can be retrieved by PTR_ERR macros.
- *
- * @m: mux data
- * @tc: request to be sent
- * @cb: callback function to call when response is received
- * @cba: parameter to pass to the callback function
- *
- */
-
-static struct p9_req *p9_send_request(struct p9_conn *m,
-                                         struct p9_fcall *tc,
-                                         p9_conn_req_callback cb, void *cba)
+static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
 {
-       int n;
-       struct p9_req *req;
-
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
-               tc, tc->id);
-       if (m->err < 0)
-               return ERR_PTR(m->err);
-
-       req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
-       if (!req)
-               return ERR_PTR(-ENOMEM);
-
-       if (tc->id == P9_TVERSION)
-               n = P9_NOTAG;
-       else
-               n = p9_mux_get_tag(m);
-
-       if (n < 0)
-               return ERR_PTR(-ENOMEM);
-
-       p9_set_tag(tc, n);
-
-#ifdef CONFIG_NET_9P_DEBUG
-       if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
-               char buf[150];
-
-               p9_printfcall(buf, sizeof(buf), tc, m->extended);
-               printk(KERN_NOTICE "<<< %p %s\n", m, buf);
-       }
-#endif
-
-       spin_lock_init(&req->lock);
-       req->tag = n;
-       req->tcall = tc;
-       req->rcall = NULL;
-       req->err = 0;
-       req->cb = cb;
-       req->cba = cba;
-       req->flush = None;
-
-       spin_lock(&m->lock);
-       list_add_tail(&req->req_list, &m->unsent_req_list);
-       spin_unlock(&m->lock);
-
-       if (test_and_clear_bit(Wpending, &m->wsched))
-               n = POLLOUT;
-       else
-               n = p9_fd_poll(m->trans, NULL);
-
-       if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
-               queue_work(p9_mux_wq, &m->wq);
+       struct p9_poll_wait *pwait =
+               container_of(wait, struct p9_poll_wait, wait);
+       struct p9_conn *m = pwait->conn;
+       unsigned long flags;
+       DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
 
-       return req;
-}
+       spin_lock_irqsave(&p9_poll_lock, flags);
+       if (list_empty(&m->poll_pending_link))
+               list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
+       spin_unlock_irqrestore(&p9_poll_lock, flags);
 
-static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
-{
-       p9_mux_put_tag(m, req->tag);
-       kfree(req);
+       /* perform the default wake up operation */
+       return default_wake_function(&dummy_wait, mode, sync, key);
 }
 
-static void p9_mux_flush_cb(struct p9_req *freq, void *a)
+/**
+ * p9_pollwait - add poll task to the wait queue
+ * @filp: file pointer being polled
+ * @wait_address: wait_q to block on
+ * @p: poll state
+ *
+ * called by files poll operation to add v9fs-poll task to files wait queue
+ */
+
+static void
+p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 {
-       int tag;
-       struct p9_conn *m;
-       struct p9_req *req, *rreq, *rptr;
-
-       m = a;
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
-               freq->tcall, freq->rcall, freq->err,
-               freq->tcall->params.tflush.oldtag);
-
-       spin_lock(&m->lock);
-       tag = freq->tcall->params.tflush.oldtag;
-       req = NULL;
-       list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
-               if (rreq->tag == tag) {
-                       req = rreq;
-                       list_del(&req->req_list);
+       struct p9_conn *m = container_of(p, struct p9_conn, pt);
+       struct p9_poll_wait *pwait = NULL;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
+               if (m->poll_wait[i].wait_addr == NULL) {
+                       pwait = &m->poll_wait[i];
                        break;
                }
        }
-       spin_unlock(&m->lock);
 
-       if (req) {
-               spin_lock(&req->lock);
-               req->flush = Flushed;
-               spin_unlock(&req->lock);
-
-               if (req->cb)
-                       (*req->cb) (req, req->cba);
-               else
-                       kfree(req->rcall);
+       if (!pwait) {
+               P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
+               return;
        }
 
-       kfree(freq->tcall);
-       kfree(freq->rcall);
-       p9_mux_free_request(m, freq);
+       pwait->conn = m;
+       pwait->wait_addr = wait_address;
+       init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
+       add_wait_queue(wait_address, &pwait->wait);
 }
 
-static int
-p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
-{
-       struct p9_fcall *fc;
-       struct p9_req *rreq, *rptr;
-
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
+/**
+ * p9_conn_create - allocate and initialize the per-session mux data
+ * @client: client instance
+ *
+ * Note: Creates the polling task if this is the first session.
+ */
 
-       /* if a response was received for a request, do nothing */
-       spin_lock(&req->lock);
-       if (req->rcall || req->err) {
-               spin_unlock(&req->lock);
-               P9_DPRINTK(P9_DEBUG_MUX,
-                       "mux %p req %p response already received\n", m, req);
-               return 0;
-       }
+static struct p9_conn *p9_conn_create(struct p9_client *client)
+{
+       int n;
+       struct p9_conn *m;
 
-       req->flush = Flushing;
-       spin_unlock(&req->lock);
-
-       spin_lock(&m->lock);
-       /* if the request is not sent yet, just remove it from the list */
-       list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
-               if (rreq->tag == req->tag) {
-                       P9_DPRINTK(P9_DEBUG_MUX,
-                          "mux %p req %p request is not sent yet\n", m, req);
-                       list_del(&rreq->req_list);
-                       req->flush = Flushed;
-                       spin_unlock(&m->lock);
-                       if (req->cb)
-                               (*req->cb) (req, req->cba);
-                       return 0;
-               }
-       }
-       spin_unlock(&m->lock);
+       P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
+                                                               client->msize);
+       m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
+       if (!m)
+               return ERR_PTR(-ENOMEM);
 
-       clear_thread_flag(TIF_SIGPENDING);
-       fc = p9_create_tflush(req->tag);
-       p9_send_request(m, fc, p9_mux_flush_cb, m);
-       return 1;
-}
+       INIT_LIST_HEAD(&m->mux_list);
+       m->client = client;
 
-static void
-p9_conn_rpc_cb(struct p9_req *req, void *a)
-{
-       struct p9_mux_rpc *r;
+       INIT_LIST_HEAD(&m->req_list);
+       INIT_LIST_HEAD(&m->unsent_req_list);
+       INIT_WORK(&m->rq, p9_read_work);
+       INIT_WORK(&m->wq, p9_write_work);
+       INIT_LIST_HEAD(&m->poll_pending_link);
+       init_poll_funcptr(&m->pt, p9_pollwait);
 
-       P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a);
-       r = a;
-       r->rcall = req->rcall;
-       r->err = req->err;
+       n = p9_fd_poll(client, &m->pt);
+       if (n & POLLIN) {
+               P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
+               set_bit(Rpending, &m->wsched);
+       }
 
-       if (req->flush != None && !req->err)
-               r->err = -ERESTARTSYS;
+       if (n & POLLOUT) {
+               P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
+               set_bit(Wpending, &m->wsched);
+       }
 
-       wake_up(&r->wqueue);
+       return m;
 }
 
 /**
- * p9_fd_rpc- sends 9P request and waits until a response is available.
- *     The function can be interrupted.
- * @t: transport data
- * @tc: request to be sent
- * @rc: pointer where a pointer to the response is stored
+ * p9_poll_mux - polls a mux and schedules read or write works if necessary
+ * @m: connection to poll
  *
  */
 
-int
-p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
+static void p9_poll_mux(struct p9_conn *m)
 {
-       struct p9_trans_fd *p = t->priv;
-       struct p9_conn *m = p->conn;
-       int err, sigpending;
-       unsigned long flags;
-       struct p9_req *req;
-       struct p9_mux_rpc r;
-
-       r.err = 0;
-       r.tcall = tc;
-       r.rcall = NULL;
-       r.m = m;
-       init_waitqueue_head(&r.wqueue);
-
-       if (rc)
-               *rc = NULL;
-
-       sigpending = 0;
-       if (signal_pending(current)) {
-               sigpending = 1;
-               clear_thread_flag(TIF_SIGPENDING);
-       }
+       int n;
 
-       req = p9_send_request(m, tc, p9_conn_rpc_cb, &r);
-       if (IS_ERR(req)) {
-               err = PTR_ERR(req);
-               P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
-               return err;
+       if (m->err < 0)
+               return;
+
+       n = p9_fd_poll(m->client, NULL);
+       if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
+               P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
+               if (n >= 0)
+                       n = -ECONNRESET;
+               p9_conn_cancel(m, n);
        }
 
-       err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0);
-       if (r.err < 0)
-               err = r.err;
-
-       if (err == -ERESTARTSYS && m->trans->status == Connected
-                                                       && m->err == 0) {
-               if (p9_mux_flush_request(m, req)) {
-                       /* wait until we get response of the flush message */
-                       do {
-                               clear_thread_flag(TIF_SIGPENDING);
-                               err = wait_event_interruptible(r.wqueue,
-                                       r.rcall || r.err);
-                       } while (!r.rcall && !r.err && err == -ERESTARTSYS &&
-                               m->trans->status == Connected && !m->err);
-
-                       err = -ERESTARTSYS;
+       if (n & POLLIN) {
+               set_bit(Rpending, &m->wsched);
+               P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
+               if (!test_and_set_bit(Rworksched, &m->wsched)) {
+                       P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
+                       queue_work(p9_mux_wq, &m->rq);
                }
-               sigpending = 1;
        }
 
-       if (sigpending) {
-               spin_lock_irqsave(&current->sighand->siglock, flags);
-               recalc_sigpending();
-               spin_unlock_irqrestore(&current->sighand->siglock, flags);
+       if (n & POLLOUT) {
+               set_bit(Wpending, &m->wsched);
+               P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
+               if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
+                   !test_and_set_bit(Wworksched, &m->wsched)) {
+                       P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
+                       queue_work(p9_mux_wq, &m->wq);
+               }
        }
-
-       if (rc)
-               *rc = r.rcall;
-       else
-               kfree(r.rcall);
-
-       p9_mux_free_request(m, req);
-       if (err > 0)
-               err = -EIO;
-
-       return err;
 }
 
-#ifdef P9_NONBLOCK
 /**
- * p9_conn_rpcnb - sends 9P request without waiting for response.
- * @m: mux data
- * @tc: request to be sent
- * @cb: callback function to be called when response arrives
- * @a: value to pass to the callback function
+ * p9_fd_request - send 9P request
+ * The function can sleep until the request is scheduled for sending.
+ * The function can be interrupted. Return from the function is not
+ * a guarantee that the request is sent successfully.
+ *
+ * @client: client instance
+ * @req: request to be sent
  *
  */
 
-int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
-                  p9_conn_req_callback cb, void *a)
+static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
 {
-       int err;
-       struct p9_req *req;
+       int n;
+       struct p9_trans_fd *ts = client->trans;
+       struct p9_conn *m = ts->conn;
 
-       req = p9_send_request(m, tc, cb, a);
-       if (IS_ERR(req)) {
-               err = PTR_ERR(req);
-               P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
-               return PTR_ERR(req);
-       }
+       P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
+                                               current, req->tc, req->tc->id);
+       if (m->err < 0)
+               return m->err;
+
+       spin_lock(&client->lock);
+       req->status = REQ_STATUS_UNSENT;
+       list_add_tail(&req->req_list, &m->unsent_req_list);
+       spin_unlock(&client->lock);
+
+       if (test_and_clear_bit(Wpending, &m->wsched))
+               n = POLLOUT;
+       else
+               n = p9_fd_poll(m->client, NULL);
+
+       if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
+               queue_work(p9_mux_wq, &m->wq);
 
-       P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
        return 0;
 }
-#endif /* P9_NONBLOCK */
-
-/**
- * p9_conn_cancel - cancel all pending requests with error
- * @m: mux data
- * @err: error code
- *
- */
 
-void p9_conn_cancel(struct p9_conn *m, int err)
+static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
 {
-       struct p9_req *req, *rtmp;
-       LIST_HEAD(cancel_list);
+       int ret = 1;
 
-       P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
-       m->err = err;
-       spin_lock(&m->lock);
-       list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
-               list_move(&req->req_list, &cancel_list);
-       }
-       list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
-               list_move(&req->req_list, &cancel_list);
-       }
-       spin_unlock(&m->lock);
+       P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 
-       list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
+       spin_lock(&client->lock);
+
+       if (req->status == REQ_STATUS_UNSENT) {
                list_del(&req->req_list);
-               if (!req->err)
-                       req->err = err;
+               req->status = REQ_STATUS_FLSHD;
+               ret = 0;
+       } else if (req->status == REQ_STATUS_SENT)
+               req->status = REQ_STATUS_FLSH;
 
-               if (req->cb)
-                       (*req->cb) (req, req->cba);
-               else
-                       kfree(req->rcall);
-       }
+       spin_unlock(&client->lock);
+
+       return ret;
 }
 
 /**
- * parse_options - parse mount options into session structure
- * @options: options string passed from mount
- * @opts: transport-specific structure to parse options into
+ * parse_opts - parse mount options into p9_fd_opts structure
+ * @params: options string passed from mount
+ * @opts: fd transport-specific structure to parse options into
  *
  * Returns 0 upon success, -ERRNO upon failure
  */
@@ -1205,12 +735,14 @@ static int parse_opts(char *params, struct p9_fd_opts *opts)
                if (!*p)
                        continue;
                token = match_token(p, tokens, args);
-               r = match_int(&args[0], &option);
-               if (r < 0) {
-                       P9_DPRINTK(P9_DEBUG_ERROR,
-                        "integer field, but no integer?\n");
-                       ret = r;
-                       continue;
+               if (token != Opt_err) {
+                       r = match_int(&args[0], &option);
+                       if (r < 0) {
+                               P9_DPRINTK(P9_DEBUG_ERROR,
+                               "integer field, but no integer?\n");
+                               ret = r;
+                               continue;
+                       }
                }
                switch (token) {
                case Opt_port:
@@ -1230,7 +762,7 @@ static int parse_opts(char *params, struct p9_fd_opts *opts)
        return 0;
 }
 
-static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
+static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 {
        struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
                                           GFP_KERNEL);
@@ -1248,13 +780,13 @@ static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
                return -EIO;
        }
 
-       trans->priv = ts;
-       trans->status = Connected;
+       client->trans = ts;
+       client->status = Connected;
 
        return 0;
 }
 
-static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
+static int p9_socket_open(struct p9_client *client, struct socket *csocket)
 {
        int fd, ret;
 
@@ -1265,137 +797,65 @@ static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
                return fd;
        }
 
-       ret = p9_fd_open(trans, fd, fd);
+       ret = p9_fd_open(client, 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;
+       ((struct p9_trans_fd *)client->trans)->rd->f_flags |= O_NONBLOCK;
 
        return 0;
 }
 
 /**
- * p9_fd_read- read from a fd
- * @trans: transport instance state
- * @v: buffer to receive data into
- * @len: size of receive buffer
- *
- */
-
-static int p9_fd_read(struct p9_trans *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
- * @trans: transport instance state
- * @v: buffer to send data from
- * @len: size of send buffer
+ * p9_mux_destroy - cancels all pending requests and frees mux resources
+ * @m: mux to destroy
  *
  */
 
-static int p9_fd_write(struct p9_trans *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_trans *trans, struct poll_table_struct *pt)
+static void p9_conn_destroy(struct p9_conn *m)
 {
-       int ret, n;
-       struct p9_trans_fd *ts = NULL;
-
-       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;
+       P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
+               m->mux_list.prev, m->mux_list.next);
 
-       ret = ts->rd->f_op->poll(ts->rd, pt);
-       if (ret < 0)
-               return ret;
+       p9_mux_poll_stop(m);
+       cancel_work_sync(&m->rq);
+       cancel_work_sync(&m->wq);
 
-       if (ts->rd != ts->wr) {
-               n = ts->wr->f_op->poll(ts->wr, pt);
-               if (n < 0)
-                       return n;
-               ret = (ret & ~POLLOUT) | (n & ~POLLIN);
-       }
+       p9_conn_cancel(m, -ECONNRESET);
 
-       return ret;
+       m->client = NULL;
+       kfree(m);
 }
 
 /**
- * p9_fd_close - shutdown socket
- * @trans: private socket structure
+ * p9_fd_close - shutdown file descriptor transport
+ * @client: client instance
  *
  */
 
-static void p9_fd_close(struct p9_trans *trans)
+static void p9_fd_close(struct p9_client *client)
 {
        struct p9_trans_fd *ts;
 
-       if (!trans)
+       if (!client)
                return;
 
-       ts = xchg(&trans->priv, NULL);
-
+       ts = client->trans;
        if (!ts)
                return;
 
+       client->status = Disconnected;
+
        p9_conn_destroy(ts->conn);
 
-       trans->status = Disconnected;
        if (ts->rd)
                fput(ts->rd);
        if (ts->wr)
                fput(ts->wr);
+
        kfree(ts);
 }
 
@@ -1416,31 +876,23 @@ static inline int valid_ipaddr4(const char *buf)
        return 0;
 }
 
-static struct p9_trans *
-p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
+static int
+p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
 {
        int err;
-       struct p9_trans *trans;
        struct socket *csocket;
        struct sockaddr_in sin_server;
        struct p9_fd_opts opts;
-       struct p9_trans_fd *p;
+       struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
 
        err = parse_opts(args, &opts);
        if (err < 0)
-               return ERR_PTR(err);
+               return err;
 
        if (valid_ipaddr4(addr) < 0)
-               return ERR_PTR(-EINVAL);
+               return -EINVAL;
 
        csocket = NULL;
-       trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
-       if (!trans)
-               return ERR_PTR(-ENOMEM);
-       trans->msize = msize;
-       trans->extended = dotu;
-       trans->rpc = p9_fd_rpc;
-       trans->close = p9_fd_close;
 
        sin_server.sin_family = AF_INET;
        sin_server.sin_addr.s_addr = in_aton(addr);
@@ -1463,45 +915,38 @@ p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
                goto error;
        }
 
-       err = p9_socket_open(trans, csocket);
+       err = p9_socket_open(client, csocket);
        if (err < 0)
                goto error;
 
-       p = (struct p9_trans_fd *) trans->priv;
-       p->conn = p9_conn_create(trans);
+       p = (struct p9_trans_fd *) client->trans;
+       p->conn = p9_conn_create(client);
        if (IS_ERR(p->conn)) {
                err = PTR_ERR(p->conn);
                p->conn = NULL;
                goto error;
        }
 
-       return trans;
+       return 0;
 
 error:
        if (csocket)
                sock_release(csocket);
 
-       kfree(trans);
-       return ERR_PTR(err);
+       kfree(p);
+
+       return err;
 }
 
-static struct p9_trans *
-p9_trans_create_unix(const char *addr, char *args, int msize,
-                                                       unsigned char dotu)
+static int
+p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
 {
        int err;
        struct socket *csocket;
        struct sockaddr_un sun_server;
-       struct p9_trans *trans;
-       struct p9_trans_fd *p;
+       struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
 
        csocket = NULL;
-       trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
-       if (!trans)
-               return ERR_PTR(-ENOMEM);
-
-       trans->rpc = p9_fd_rpc;
-       trans->close = p9_fd_close;
 
        if (strlen(addr) > UNIX_PATH_MAX) {
                P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
@@ -1522,79 +967,69 @@ p9_trans_create_unix(const char *addr, char *args, int msize,
                goto error;
        }
 
-       err = p9_socket_open(trans, csocket);
+       err = p9_socket_open(client, csocket);
        if (err < 0)
                goto error;
 
-       trans->msize = msize;
-       trans->extended = dotu;
-       p = (struct p9_trans_fd *) trans->priv;
-       p->conn = p9_conn_create(trans);
+       p = (struct p9_trans_fd *) client->trans;
+       p->conn = p9_conn_create(client);
        if (IS_ERR(p->conn)) {
                err = PTR_ERR(p->conn);
                p->conn = NULL;
                goto error;
        }
 
-       return trans;
+       return 0;
 
 error:
        if (csocket)
                sock_release(csocket);
 
-       kfree(trans);
-       return ERR_PTR(err);
+       kfree(p);
+       return err;
 }
 
-static struct p9_trans *
-p9_trans_create_fd(const char *name, char *args, int msize,
-                                                       unsigned char extended)
+static int
+p9_fd_create(struct p9_client *client, const char *addr, char *args)
 {
        int err;
-       struct p9_trans *trans;
        struct p9_fd_opts opts;
-       struct p9_trans_fd *p;
+       struct p9_trans_fd *p = NULL; /* this get allocated in p9_fd_open */
 
        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);
+               return -ENOPROTOOPT;
        }
 
-       trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
-       if (!trans)
-               return ERR_PTR(-ENOMEM);
-
-       trans->rpc = p9_fd_rpc;
-       trans->close = p9_fd_close;
-
-       err = p9_fd_open(trans, opts.rfd, opts.wfd);
+       err = p9_fd_open(client, opts.rfd, opts.wfd);
        if (err < 0)
                goto error;
 
-       trans->msize = msize;
-       trans->extended = extended;
-       p = (struct p9_trans_fd *) trans->priv;
-       p->conn = p9_conn_create(trans);
+       p = (struct p9_trans_fd *) client->trans;
+       p->conn = p9_conn_create(client);
        if (IS_ERR(p->conn)) {
                err = PTR_ERR(p->conn);
                p->conn = NULL;
                goto error;
        }
 
-       return trans;
+       return 0;
 
 error:
-       kfree(trans);
-       return ERR_PTR(err);
+       kfree(p);
+       return err;
 }
 
 static struct p9_trans_module p9_tcp_trans = {
        .name = "tcp",
        .maxsize = MAX_SOCK_BUF,
        .def = 1,
-       .create = p9_trans_create_tcp,
+       .create = p9_fd_create_tcp,
+       .close = p9_fd_close,
+       .request = p9_fd_request,
+       .cancel = p9_fd_cancel,
        .owner = THIS_MODULE,
 };
 
@@ -1602,7 +1037,10 @@ static struct p9_trans_module p9_unix_trans = {
        .name = "unix",
        .maxsize = MAX_SOCK_BUF,
        .def = 0,
-       .create = p9_trans_create_unix,
+       .create = p9_fd_create_unix,
+       .close = p9_fd_close,
+       .request = p9_fd_request,
+       .cancel = p9_fd_cancel,
        .owner = THIS_MODULE,
 };
 
@@ -1610,16 +1048,69 @@ static struct p9_trans_module p9_fd_trans = {
        .name = "fd",
        .maxsize = MAX_SOCK_BUF,
        .def = 0,
-       .create = p9_trans_create_fd,
+       .create = p9_fd_create,
+       .close = p9_fd_close,
+       .request = p9_fd_request,
+       .cancel = p9_fd_cancel,
        .owner = THIS_MODULE,
 };
 
+/**
+ * p9_poll_proc - poll worker thread
+ * @a: thread state and arguments
+ *
+ * polls all v9fs transports for new events and queues the appropriate
+ * work to the work queue
+ *
+ */
+
+static int p9_poll_proc(void *a)
+{
+       unsigned long flags;
+
+       P9_DPRINTK(P9_DEBUG_TRANS, "start %p\n", current);
+ repeat:
+       spin_lock_irqsave(&p9_poll_lock, flags);
+       while (!list_empty(&p9_poll_pending_list)) {
+               struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
+                                                       struct p9_conn,
+                                                       poll_pending_link);
+               list_del_init(&conn->poll_pending_link);
+               spin_unlock_irqrestore(&p9_poll_lock, flags);
+
+               p9_poll_mux(conn);
+
+               spin_lock_irqsave(&p9_poll_lock, flags);
+       }
+       spin_unlock_irqrestore(&p9_poll_lock, flags);
+
+       set_current_state(TASK_INTERRUPTIBLE);
+       if (list_empty(&p9_poll_pending_list)) {
+               P9_DPRINTK(P9_DEBUG_TRANS, "sleeping...\n");
+               schedule();
+       }
+       __set_current_state(TASK_RUNNING);
+
+       if (!kthread_should_stop())
+               goto repeat;
+
+       P9_DPRINTK(P9_DEBUG_TRANS, "finish\n");
+       return 0;
+}
+
 int p9_trans_fd_init(void)
 {
-       int ret = p9_mux_global_init();
-       if (ret) {
-               printk(KERN_WARNING "9p: starting mux failed\n");
-               return ret;
+       p9_mux_wq = create_workqueue("v9fs");
+       if (!p9_mux_wq) {
+               printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
+               return -ENOMEM;
+       }
+
+       p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
+       if (IS_ERR(p9_poll_task)) {
+               destroy_workqueue(p9_mux_wq);
+               printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
+               return PTR_ERR(p9_poll_task);
        }
 
        v9fs_register_trans(&p9_tcp_trans);
@@ -1631,7 +1122,10 @@ int p9_trans_fd_init(void)
 
 void p9_trans_fd_exit(void)
 {
+       kthread_stop(p9_poll_task);
        v9fs_unregister_trans(&p9_tcp_trans);
        v9fs_unregister_trans(&p9_unix_trans);
        v9fs_unregister_trans(&p9_fd_trans);
+
+       destroy_workqueue(p9_mux_wq);
 }