aboutsummaryrefslogtreecommitdiff
path: root/net/9p/mux.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/9p/mux.c')
-rw-r--r--net/9p/mux.c1060
1 files changed, 0 insertions, 1060 deletions
diff --git a/net/9p/mux.c b/net/9p/mux.c
deleted file mode 100644
index c9f0805048e..00000000000
--- a/net/9p/mux.c
+++ /dev/null
@@ -1,1060 +0,0 @@
-/*
- * net/9p/mux.c
- *
- * Protocol Multiplexer
- *
- * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
- * Copyright (C) 2004-2005 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/poll.h>
-#include <linux/kthread.h>
-#include <linux/idr.h>
-#include <linux/mutex.h>
-#include <net/9p/9p.h>
-#include <linux/parser.h>
-#include <net/9p/transport.h>
-#include <net/9p/conn.h>
-
-#define ERREQFLUSH 1
-#define SCHED_TIMEOUT 10
-#define MAXPOLLWADDR 2
-
-enum {
- Rworksched = 1, /* read work scheduled or running */
- Rpending = 2, /* can read */
- Wworksched = 4, /* write work scheduled or running */
- Wpending = 8, /* can write */
-};
-
-enum {
- None,
- Flushing,
- Flushed,
-};
-
-struct p9_mux_poll_task;
-
-struct p9_req {
- spinlock_t lock; /* protect request structure */
- 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_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;
- int err;
- wait_queue_head_t equeue;
- struct list_head req_list;
- struct list_head unsent_req_list;
- struct p9_fcall *rcall;
- int rpos;
- char *rbuf;
- int wpos;
- int wsize;
- char *wbuf;
- wait_queue_t poll_wait[MAXPOLLWADDR];
- wait_queue_head_t *poll_waddr[MAXPOLLWADDR];
- poll_table pt;
- struct work_struct rq;
- struct work_struct wq;
- unsigned long wsched;
-};
-
-struct p9_mux_poll_task {
- struct task_struct *task;
- struct list_head mux_list;
- int muxnum;
-};
-
-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 u16 p9_mux_get_tag(struct p9_conn *);
-static void p9_mux_put_tag(struct p9_conn *, u16);
-
-static DEFINE_MUTEX(p9_mux_task_lock);
-static struct workqueue_struct *p9_mux_wq;
-
-static int p9_mux_num;
-static int p9_mux_poll_task_num;
-static struct p9_mux_poll_task p9_mux_poll_tasks[100];
-
-int p9_mux_global_init(void)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++)
- p9_mux_poll_tasks[i].task = NULL;
-
- p9_mux_wq = create_workqueue("v9fs");
- if (!p9_mux_wq) {
- printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
- return -ENOMEM;
- }
-
- return 0;
-}
-
-void p9_mux_global_exit(void)
-{
- destroy_workqueue(p9_mux_wq);
-}
-
-/**
- * p9_mux_calc_poll_procs - calculates the number of polling procs
- * 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)
-{
- int n;
-
- if (p9_mux_poll_task_num)
- n = muxnum / p9_mux_poll_task_num +
- (muxnum % p9_mux_poll_task_num ? 1 : 0);
- else
- n = 1;
-
- if (n > ARRAY_SIZE(p9_mux_poll_tasks))
- n = ARRAY_SIZE(p9_mux_poll_tasks);
-
- return n;
-}
-
-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;
- }
- }
-
- if (i >= ARRAY_SIZE(p9_mux_poll_tasks))
- P9_DPRINTK(P9_DEBUG_ERROR,
- "warning: no free poll slots\n");
- }
-
- 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;
- }
- }
- }
-
- 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);
- }
-
- p9_mux_num++;
- mutex_unlock(&p9_mux_task_lock);
-
- return 0;
-}
-
-static void p9_mux_poll_stop(struct p9_conn *m)
-{
- 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
- * Creates the polling task if this is the first session.
- *
- * @trans - transport structure
- * @msize - maximum message size
- * @extended - pointer to the extended flag
- */
-struct p9_conn *p9_conn_create(struct p9_trans *trans, int msize,
- unsigned char *extended)
-{
- int i, n;
- struct p9_conn *m, *mtmp;
-
- P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans, msize);
- m = kmalloc(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 = msize;
- m->extended = extended;
- m->trans = trans;
- m->tagpool = p9_idpool_create();
- if (IS_ERR(m->tagpool)) {
- mtmp = ERR_PTR(-ENOMEM);
- kfree(m);
- return mtmp;
- }
-
- m->err = 0;
- init_waitqueue_head(&m->equeue);
- INIT_LIST_HEAD(&m->req_list);
- INIT_LIST_HEAD(&m->unsent_req_list);
- m->rcall = NULL;
- m->rpos = 0;
- m->rbuf = NULL;
- m->wpos = m->wsize = 0;
- m->wbuf = NULL;
- INIT_WORK(&m->rq, p9_read_work);
- INIT_WORK(&m->wq, p9_write_work);
- m->wsched = 0;
- memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
- m->poll_task = NULL;
- n = p9_mux_poll_start(m);
- if (n) {
- kfree(m);
- return ERR_PTR(n);
- }
-
- n = trans->poll(trans, &m->pt);
- if (n & POLLIN) {
- P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
- set_bit(Rpending, &m->wsched);
- }
-
- if (n & POLLOUT) {
- P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
- set_bit(Wpending, &m->wsched);
- }
-
- for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
- if (IS_ERR(m->poll_waddr[i])) {
- p9_mux_poll_stop(m);
- mtmp = (void *)m->poll_waddr; /* the error code */
- kfree(m);
- m = mtmp;
- break;
- }
- }
-
- return m;
-}
-EXPORT_SYMBOL(p9_conn_create);
-
-/**
- * p9_mux_destroy - cancels all pending requests and frees mux resources
- */
-void p9_conn_destroy(struct p9_conn *m)
-{
- P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
- m->mux_list.prev, m->mux_list.next);
- p9_conn_cancel(m, -ECONNRESET);
-
- if (!list_empty(&m->req_list)) {
- /* wait until all processes waiting on this session exit */
- P9_DPRINTK(P9_DEBUG_MUX,
- "mux %p waiting for empty request queue\n", m);
- wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000);
- P9_DPRINTK(P9_DEBUG_MUX, "mux %p request queue empty: %d\n", m,
- list_empty(&m->req_list));
- }
-
- p9_mux_poll_stop(m);
- m->trans = NULL;
- p9_idpool_destroy(m->tagpool);
- kfree(m);
-}
-EXPORT_SYMBOL(p9_conn_destroy);
-
-/**
- * p9_pollwait - 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 i;
- 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;
-
- if (i >= ARRAY_SIZE(m->poll_waddr)) {
- P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
- return;
- }
-
- m->poll_waddr[i] = wait_address;
-
- if (!wait_address) {
- P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
- m->poll_waddr[i] = ERR_PTR(-EIO);
- return;
- }
-
- init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
- add_wait_queue(wait_address, &m->poll_wait[i]);
-}
-
-/**
- * p9_poll_mux - polls a mux and schedules read or write works if necessary
- */
-static void p9_poll_mux(struct p9_conn *m)
-{
- int n;
-
- if (m->err < 0)
- return;
-
- n = m->trans->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);
- }
-
- 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);
- }
- }
-
- 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);
- }
- }
-}
-
-/**
- * p9_poll_proc - polls all v9fs transports for new events and queues
- * the appropriate work to the work queue
- */
-static int p9_poll_proc(void *a)
-{
- struct p9_conn *m, *mtmp;
- struct p9_mux_poll_task *vpt;
-
- vpt = a;
- P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt);
- while (!kthread_should_stop()) {
- set_current_state(TASK_INTERRUPTIBLE);
-
- list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
- p9_poll_mux(m);
- }
-
- P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
- schedule_timeout(SCHED_TIMEOUT * HZ);
- }
-
- __set_current_state(TASK_RUNNING);
- P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
- return 0;
-}
-
-/**
- * p9_write_work - called when a transport can send some data
- */
-static void p9_write_work(struct work_struct *work)
-{
- int n, err;
- struct p9_conn *m;
- struct p9_req *req;
-
- m = container_of(work, struct p9_conn, wq);
-
- if (m->err < 0) {
- clear_bit(Wworksched, &m->wsched);
- return;
- }
-
- if (!m->wsize) {
- if (list_empty(&m->unsent_req_list)) {
- clear_bit(Wworksched, &m->wsched);
- return;
- }
-
- spin_lock(&m->lock);
-again:
- req = list_entry(m->unsent_req_list.next, struct p9_req,
- req_list);
- 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->wpos = 0;
- spin_unlock(&m->lock);
- }
-
- P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
- m->wsize);
- clear_bit(Wpending, &m->wsched);
- err = m->trans->write(m->trans, m->wbuf + m->wpos, m->wsize - m->wpos);
- P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
- if (err == -EAGAIN) {
- clear_bit(Wworksched, &m->wsched);
- return;
- }
-
- if (err < 0)
- goto error;
- else if (err == 0) {
- err = -EREMOTEIO;
- goto error;
- }
-
- m->wpos += err;
- if (m->wpos == m->wsize)
- m->wpos = m->wsize = 0;
-
- if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
- if (test_and_clear_bit(Wpending, &m->wsched))
- n = POLLOUT;
- else
- n = m->trans->poll(m->trans, NULL);
-
- if (n & POLLOUT) {
- P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
- queue_work(p9_mux_wq, &m->wq);
- } else
- clear_bit(Wworksched, &m->wsched);
- } else
- clear_bit(Wworksched, &m->wsched);
-
- return;
-
-error:
- p9_conn_cancel(m, err);
- 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);
-
- if (!req->err) { /* string match failed */
- PRINT_FCALL_ERROR("unknown error", req->rcall);
- }
-
- if (!req->err)
- 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
- */
-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 = m->trans->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);
-
- wake_up(&m->equeue);
- }
- } 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 = m->trans->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)
-{
- 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 = m->trans->poll(m->trans, NULL);
-
- if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
- queue_work(p9_mux_wq, &m->wq);
-
- return req;
-}
-
-static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
-{
- p9_mux_put_tag(m, req->tag);
- kfree(req);
-}
-
-static void p9_mux_flush_cb(struct p9_req *freq, void *a)
-{
- p9_conn_req_callback cb;
- 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);
- cb = NULL;
- 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);
- 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);
-
- wake_up(&m->equeue);
- }
-
- kfree(freq->tcall);
- kfree(freq->rcall);
- p9_mux_free_request(m, freq);
-}
-
-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);
-
- /* 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;
- }
-
- 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);
-
- clear_thread_flag(TIF_SIGPENDING);
- fc = p9_create_tflush(req->tag);
- p9_send_request(m, fc, p9_mux_flush_cb, m);
- return 1;
-}
-
-static void
-p9_conn_rpc_cb(struct p9_req *req, void *a)
-{
- struct p9_mux_rpc *r;
-
- P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a);
- r = a;
- r->rcall = req->rcall;
- r->err = req->err;
-
- if (req->flush != None && !req->err)
- r->err = -ERESTARTSYS;
-
- wake_up(&r->wqueue);
-}
-
-/**
- * p9_mux_rpc - sends 9P request and waits until a response is available.
- * The function can be interrupted.
- * @m: mux data
- * @tc: request to be sent
- * @rc: pointer where a pointer to the response is stored
- */
-int
-p9_conn_rpc(struct p9_conn *m, struct p9_fcall *tc,
- struct p9_fcall **rc)
-{
- 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);
- }
-
- 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;
- }
-
- 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;
- }
- sigpending = 1;
- }
-
- if (sigpending) {
- spin_lock_irqsave(&current->sighand->siglock, flags);
- recalc_sigpending();
- spin_unlock_irqrestore(&current->sighand->siglock, flags);
- }
-
- if (rc)
- *rc = r.rcall;
- else
- kfree(r.rcall);
-
- p9_mux_free_request(m, req);
- if (err > 0)
- err = -EIO;
-
- return err;
-}
-EXPORT_SYMBOL(p9_conn_rpc);
-
-#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
- * @cba: value to pass to the callback function
- */
-int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
- p9_conn_req_callback cb, void *a)
-{
- int err;
- struct p9_req *req;
-
- 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_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
- return 0;
-}
-EXPORT_SYMBOL(p9_conn_rpcnb);
-#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)
-{
- struct p9_req *req, *rtmp;
- LIST_HEAD(cancel_list);
-
- 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);
-
- list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
- list_del(&req->req_list);
- if (!req->err)
- req->err = err;
-
- if (req->cb)
- (*req->cb) (req, req->cba);
- else
- kfree(req->rcall);
- }
-
- wake_up(&m->equeue);
-}
-EXPORT_SYMBOL(p9_conn_cancel);
-
-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);
-}