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1033 lines
23 KiB
1033 lines
23 KiB
/*
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* linux/fs/9p/mux.c
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*
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* Protocol Multiplexer
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*
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* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
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* Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to:
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* Free Software Foundation
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* 51 Franklin Street, Fifth Floor
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* Boston, MA 02111-1301 USA
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*
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/poll.h>
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#include <linux/kthread.h>
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#include <linux/idr.h>
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#include <linux/mutex.h>
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#include "debug.h"
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#include "v9fs.h"
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#include "9p.h"
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#include "conv.h"
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#include "transport.h"
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#include "mux.h"
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#define ERREQFLUSH 1
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#define SCHED_TIMEOUT 10
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#define MAXPOLLWADDR 2
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enum {
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Rworksched = 1, /* read work scheduled or running */
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Rpending = 2, /* can read */
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Wworksched = 4, /* write work scheduled or running */
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Wpending = 8, /* can write */
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};
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enum {
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None,
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Flushing,
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Flushed,
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};
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struct v9fs_mux_poll_task;
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struct v9fs_req {
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spinlock_t lock;
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int tag;
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struct v9fs_fcall *tcall;
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struct v9fs_fcall *rcall;
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int err;
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v9fs_mux_req_callback cb;
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void *cba;
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int flush;
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struct list_head req_list;
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};
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struct v9fs_mux_data {
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spinlock_t lock;
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struct list_head mux_list;
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struct v9fs_mux_poll_task *poll_task;
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int msize;
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unsigned char *extended;
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struct v9fs_transport *trans;
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struct v9fs_idpool tagpool;
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int err;
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wait_queue_head_t equeue;
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struct list_head req_list;
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struct list_head unsent_req_list;
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struct v9fs_fcall *rcall;
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int rpos;
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char *rbuf;
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int wpos;
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int wsize;
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char *wbuf;
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wait_queue_t poll_wait[MAXPOLLWADDR];
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wait_queue_head_t *poll_waddr[MAXPOLLWADDR];
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poll_table pt;
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struct work_struct rq;
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struct work_struct wq;
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unsigned long wsched;
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};
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struct v9fs_mux_poll_task {
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struct task_struct *task;
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struct list_head mux_list;
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int muxnum;
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};
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struct v9fs_mux_rpc {
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struct v9fs_mux_data *m;
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int err;
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struct v9fs_fcall *tcall;
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struct v9fs_fcall *rcall;
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wait_queue_head_t wqueue;
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};
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static int v9fs_poll_proc(void *);
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static void v9fs_read_work(void *);
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static void v9fs_write_work(void *);
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static void v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address,
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poll_table * p);
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static u16 v9fs_mux_get_tag(struct v9fs_mux_data *);
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static void v9fs_mux_put_tag(struct v9fs_mux_data *, u16);
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static DEFINE_MUTEX(v9fs_mux_task_lock);
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static struct workqueue_struct *v9fs_mux_wq;
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static int v9fs_mux_num;
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static int v9fs_mux_poll_task_num;
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static struct v9fs_mux_poll_task v9fs_mux_poll_tasks[100];
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int v9fs_mux_global_init(void)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++)
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v9fs_mux_poll_tasks[i].task = NULL;
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v9fs_mux_wq = create_workqueue("v9fs");
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if (!v9fs_mux_wq)
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return -ENOMEM;
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return 0;
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}
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void v9fs_mux_global_exit(void)
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{
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destroy_workqueue(v9fs_mux_wq);
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}
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/**
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* v9fs_mux_calc_poll_procs - calculates the number of polling procs
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* based on the number of mounted v9fs filesystems.
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*
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* The current implementation returns sqrt of the number of mounts.
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*/
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static int v9fs_mux_calc_poll_procs(int muxnum)
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{
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int n;
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if (v9fs_mux_poll_task_num)
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n = muxnum / v9fs_mux_poll_task_num +
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(muxnum % v9fs_mux_poll_task_num ? 1 : 0);
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else
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n = 1;
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if (n > ARRAY_SIZE(v9fs_mux_poll_tasks))
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n = ARRAY_SIZE(v9fs_mux_poll_tasks);
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return n;
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}
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static int v9fs_mux_poll_start(struct v9fs_mux_data *m)
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{
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int i, n;
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struct v9fs_mux_poll_task *vpt, *vptlast;
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struct task_struct *pproc;
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dprintk(DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, v9fs_mux_num,
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v9fs_mux_poll_task_num);
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mutex_lock(&v9fs_mux_task_lock);
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n = v9fs_mux_calc_poll_procs(v9fs_mux_num + 1);
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if (n > v9fs_mux_poll_task_num) {
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for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++) {
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if (v9fs_mux_poll_tasks[i].task == NULL) {
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vpt = &v9fs_mux_poll_tasks[i];
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dprintk(DEBUG_MUX, "create proc %p\n", vpt);
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pproc = kthread_create(v9fs_poll_proc, vpt,
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"v9fs-poll");
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if (!IS_ERR(pproc)) {
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vpt->task = pproc;
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INIT_LIST_HEAD(&vpt->mux_list);
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vpt->muxnum = 0;
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v9fs_mux_poll_task_num++;
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wake_up_process(vpt->task);
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}
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break;
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}
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}
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if (i >= ARRAY_SIZE(v9fs_mux_poll_tasks))
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dprintk(DEBUG_ERROR, "warning: no free poll slots\n");
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}
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n = (v9fs_mux_num + 1) / v9fs_mux_poll_task_num +
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((v9fs_mux_num + 1) % v9fs_mux_poll_task_num ? 1 : 0);
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vptlast = NULL;
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for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++) {
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vpt = &v9fs_mux_poll_tasks[i];
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if (vpt->task != NULL) {
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vptlast = vpt;
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if (vpt->muxnum < n) {
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dprintk(DEBUG_MUX, "put in proc %d\n", i);
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list_add(&m->mux_list, &vpt->mux_list);
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vpt->muxnum++;
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m->poll_task = vpt;
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memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
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init_poll_funcptr(&m->pt, v9fs_pollwait);
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break;
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}
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}
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}
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if (i >= ARRAY_SIZE(v9fs_mux_poll_tasks)) {
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if (vptlast == NULL)
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return -ENOMEM;
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dprintk(DEBUG_MUX, "put in proc %d\n", i);
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list_add(&m->mux_list, &vptlast->mux_list);
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vptlast->muxnum++;
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m->poll_task = vptlast;
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memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
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init_poll_funcptr(&m->pt, v9fs_pollwait);
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}
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v9fs_mux_num++;
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mutex_unlock(&v9fs_mux_task_lock);
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return 0;
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}
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static void v9fs_mux_poll_stop(struct v9fs_mux_data *m)
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{
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int i;
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struct v9fs_mux_poll_task *vpt;
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mutex_lock(&v9fs_mux_task_lock);
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vpt = m->poll_task;
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list_del(&m->mux_list);
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for(i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
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if (m->poll_waddr[i] != NULL) {
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remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]);
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m->poll_waddr[i] = NULL;
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}
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}
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vpt->muxnum--;
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if (!vpt->muxnum) {
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dprintk(DEBUG_MUX, "destroy proc %p\n", vpt);
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send_sig(SIGKILL, vpt->task, 1);
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vpt->task = NULL;
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v9fs_mux_poll_task_num--;
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}
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v9fs_mux_num--;
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mutex_unlock(&v9fs_mux_task_lock);
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}
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/**
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* v9fs_mux_init - allocate and initialize the per-session mux data
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* Creates the polling task if this is the first session.
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*
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* @trans - transport structure
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* @msize - maximum message size
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* @extended - pointer to the extended flag
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*/
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struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
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unsigned char *extended)
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{
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int i, n;
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struct v9fs_mux_data *m, *mtmp;
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dprintk(DEBUG_MUX, "transport %p msize %d\n", trans, msize);
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m = kmalloc(sizeof(struct v9fs_mux_data), GFP_KERNEL);
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if (!m)
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return ERR_PTR(-ENOMEM);
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spin_lock_init(&m->lock);
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INIT_LIST_HEAD(&m->mux_list);
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m->msize = msize;
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m->extended = extended;
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m->trans = trans;
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idr_init(&m->tagpool.pool);
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init_MUTEX(&m->tagpool.lock);
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m->err = 0;
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init_waitqueue_head(&m->equeue);
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INIT_LIST_HEAD(&m->req_list);
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INIT_LIST_HEAD(&m->unsent_req_list);
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m->rcall = NULL;
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m->rpos = 0;
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m->rbuf = NULL;
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m->wpos = m->wsize = 0;
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m->wbuf = NULL;
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INIT_WORK(&m->rq, v9fs_read_work, m);
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INIT_WORK(&m->wq, v9fs_write_work, m);
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m->wsched = 0;
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memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
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m->poll_task = NULL;
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n = v9fs_mux_poll_start(m);
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if (n)
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return ERR_PTR(n);
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n = trans->poll(trans, &m->pt);
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if (n & POLLIN) {
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dprintk(DEBUG_MUX, "mux %p can read\n", m);
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set_bit(Rpending, &m->wsched);
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}
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if (n & POLLOUT) {
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dprintk(DEBUG_MUX, "mux %p can write\n", m);
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set_bit(Wpending, &m->wsched);
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}
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for(i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
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if (IS_ERR(m->poll_waddr[i])) {
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v9fs_mux_poll_stop(m);
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mtmp = (void *)m->poll_waddr; /* the error code */
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kfree(m);
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m = mtmp;
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break;
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}
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}
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return m;
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}
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/**
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* v9fs_mux_destroy - cancels all pending requests and frees mux resources
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*/
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void v9fs_mux_destroy(struct v9fs_mux_data *m)
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{
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dprintk(DEBUG_MUX, "mux %p prev %p next %p\n", m,
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m->mux_list.prev, m->mux_list.next);
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v9fs_mux_cancel(m, -ECONNRESET);
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if (!list_empty(&m->req_list)) {
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/* wait until all processes waiting on this session exit */
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dprintk(DEBUG_MUX, "mux %p waiting for empty request queue\n",
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m);
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wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000);
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dprintk(DEBUG_MUX, "mux %p request queue empty: %d\n", m,
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list_empty(&m->req_list));
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}
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v9fs_mux_poll_stop(m);
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m->trans = NULL;
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kfree(m);
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}
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/**
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* v9fs_pollwait - called by files poll operation to add v9fs-poll task
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* to files wait queue
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*/
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static void
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v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address,
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poll_table * p)
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{
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int i;
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struct v9fs_mux_data *m;
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m = container_of(p, struct v9fs_mux_data, pt);
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for(i = 0; i < ARRAY_SIZE(m->poll_waddr); i++)
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if (m->poll_waddr[i] == NULL)
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break;
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if (i >= ARRAY_SIZE(m->poll_waddr)) {
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dprintk(DEBUG_ERROR, "not enough wait_address slots\n");
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return;
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}
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m->poll_waddr[i] = wait_address;
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if (!wait_address) {
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dprintk(DEBUG_ERROR, "no wait_address\n");
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m->poll_waddr[i] = ERR_PTR(-EIO);
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return;
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}
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|
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init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
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add_wait_queue(wait_address, &m->poll_wait[i]);
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}
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|
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/**
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* v9fs_poll_mux - polls a mux and schedules read or write works if necessary
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*/
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static void v9fs_poll_mux(struct v9fs_mux_data *m)
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{
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int n;
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|
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if (m->err < 0)
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return;
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|
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n = m->trans->poll(m->trans, NULL);
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if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
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dprintk(DEBUG_MUX, "error mux %p err %d\n", m, n);
|
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if (n >= 0)
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n = -ECONNRESET;
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v9fs_mux_cancel(m, n);
|
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}
|
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|
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if (n & POLLIN) {
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set_bit(Rpending, &m->wsched);
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dprintk(DEBUG_MUX, "mux %p can read\n", m);
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if (!test_and_set_bit(Rworksched, &m->wsched)) {
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dprintk(DEBUG_MUX, "schedule read work mux %p\n", m);
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queue_work(v9fs_mux_wq, &m->rq);
|
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}
|
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}
|
|
|
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if (n & POLLOUT) {
|
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set_bit(Wpending, &m->wsched);
|
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dprintk(DEBUG_MUX, "mux %p can write\n", m);
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if ((m->wsize || !list_empty(&m->unsent_req_list))
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&& !test_and_set_bit(Wworksched, &m->wsched)) {
|
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dprintk(DEBUG_MUX, "schedule write work mux %p\n", m);
|
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queue_work(v9fs_mux_wq, &m->wq);
|
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}
|
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}
|
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}
|
|
|
|
/**
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* v9fs_poll_proc - polls all v9fs transports for new events and queues
|
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* the appropriate work to the work queue
|
|
*/
|
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static int v9fs_poll_proc(void *a)
|
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{
|
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struct v9fs_mux_data *m, *mtmp;
|
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struct v9fs_mux_poll_task *vpt;
|
|
|
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vpt = a;
|
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dprintk(DEBUG_MUX, "start %p %p\n", current, vpt);
|
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allow_signal(SIGKILL);
|
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while (!kthread_should_stop()) {
|
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set_current_state(TASK_INTERRUPTIBLE);
|
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if (signal_pending(current))
|
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break;
|
|
|
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list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
|
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v9fs_poll_mux(m);
|
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}
|
|
|
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dprintk(DEBUG_MUX, "sleeping...\n");
|
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schedule_timeout(SCHED_TIMEOUT * HZ);
|
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}
|
|
|
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__set_current_state(TASK_RUNNING);
|
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dprintk(DEBUG_MUX, "finish\n");
|
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return 0;
|
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}
|
|
|
|
/**
|
|
* v9fs_write_work - called when a transport can send some data
|
|
*/
|
|
static void v9fs_write_work(void *a)
|
|
{
|
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int n, err;
|
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struct v9fs_mux_data *m;
|
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struct v9fs_req *req;
|
|
|
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m = a;
|
|
|
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if (m->err < 0) {
|
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clear_bit(Wworksched, &m->wsched);
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return;
|
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}
|
|
|
|
if (!m->wsize) {
|
|
if (list_empty(&m->unsent_req_list)) {
|
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clear_bit(Wworksched, &m->wsched);
|
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return;
|
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}
|
|
|
|
spin_lock(&m->lock);
|
|
again:
|
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req = list_entry(m->unsent_req_list.next, struct v9fs_req,
|
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req_list);
|
|
list_move_tail(&req->req_list, &m->req_list);
|
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if (req->err == ERREQFLUSH)
|
|
goto again;
|
|
|
|
m->wbuf = req->tcall->sdata;
|
|
m->wsize = req->tcall->size;
|
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m->wpos = 0;
|
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dump_data(m->wbuf, m->wsize);
|
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spin_unlock(&m->lock);
|
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}
|
|
|
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dprintk(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);
|
|
dprintk(DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
|
|
if (err == -EAGAIN) {
|
|
clear_bit(Wworksched, &m->wsched);
|
|
return;
|
|
}
|
|
|
|
if (err <= 0)
|
|
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) {
|
|
dprintk(DEBUG_MUX, "schedule write work mux %p\n", m);
|
|
queue_work(v9fs_mux_wq, &m->wq);
|
|
} else
|
|
clear_bit(Wworksched, &m->wsched);
|
|
} else
|
|
clear_bit(Wworksched, &m->wsched);
|
|
|
|
return;
|
|
|
|
error:
|
|
v9fs_mux_cancel(m, err);
|
|
clear_bit(Wworksched, &m->wsched);
|
|
}
|
|
|
|
static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req)
|
|
{
|
|
int ecode;
|
|
struct v9fs_str *ename;
|
|
|
|
if (!req->err && req->rcall->id == RERROR) {
|
|
ecode = req->rcall->params.rerror.errno;
|
|
ename = &req->rcall->params.rerror.error;
|
|
|
|
dprintk(DEBUG_MUX, "Rerror %.*s\n", ename->len, ename->str);
|
|
|
|
if (*m->extended)
|
|
req->err = -ecode;
|
|
|
|
if (!req->err) {
|
|
req->err = v9fs_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) {
|
|
dprintk(DEBUG_ERROR, "fcall mismatch: expected %d, got %d\n",
|
|
req->tcall->id + 1, req->rcall->id);
|
|
if (!req->err)
|
|
req->err = -EIO;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* v9fs_read_work - called when there is some data to be read from a transport
|
|
*/
|
|
static void v9fs_read_work(void *a)
|
|
{
|
|
int n, err;
|
|
struct v9fs_mux_data *m;
|
|
struct v9fs_req *req, *rptr, *rreq;
|
|
struct v9fs_fcall *rcall;
|
|
char *rbuf;
|
|
|
|
m = a;
|
|
|
|
if (m->err < 0)
|
|
return;
|
|
|
|
rcall = NULL;
|
|
dprintk(DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
|
|
|
|
if (!m->rcall) {
|
|
m->rcall =
|
|
kmalloc(sizeof(struct v9fs_fcall) + m->msize, GFP_KERNEL);
|
|
if (!m->rcall) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall);
|
|
m->rpos = 0;
|
|
}
|
|
|
|
clear_bit(Rpending, &m->wsched);
|
|
err = m->trans->read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos);
|
|
dprintk(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) {
|
|
dprintk(DEBUG_ERROR,
|
|
"requested packet size too big: %d\n", n);
|
|
err = -EIO;
|
|
goto error;
|
|
}
|
|
|
|
if (m->rpos < n)
|
|
break;
|
|
|
|
dump_data(m->rbuf, n);
|
|
err =
|
|
v9fs_deserialize_fcall(m->rbuf, n, m->rcall, *m->extended);
|
|
if (err < 0) {
|
|
goto error;
|
|
}
|
|
|
|
if ((v9fs_debug_level&DEBUG_FCALL) == DEBUG_FCALL) {
|
|
char buf[150];
|
|
|
|
v9fs_printfcall(buf, sizeof(buf), m->rcall,
|
|
*m->extended);
|
|
printk(KERN_NOTICE ">>> %p %s\n", m, buf);
|
|
}
|
|
|
|
rcall = m->rcall;
|
|
rbuf = m->rbuf;
|
|
if (m->rpos > n) {
|
|
m->rcall = kmalloc(sizeof(struct v9fs_fcall) + m->msize,
|
|
GFP_KERNEL);
|
|
if (!m->rcall) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall);
|
|
memmove(m->rbuf, rbuf + n, m->rpos - n);
|
|
m->rpos -= n;
|
|
} else {
|
|
m->rcall = NULL;
|
|
m->rbuf = NULL;
|
|
m->rpos = 0;
|
|
}
|
|
|
|
dprintk(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 != RFLUSH)
|
|
dprintk(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) {
|
|
dprintk(DEBUG_MUX, "schedule read work mux %p\n", m);
|
|
queue_work(v9fs_mux_wq, &m->rq);
|
|
} else
|
|
clear_bit(Rworksched, &m->wsched);
|
|
} else
|
|
clear_bit(Rworksched, &m->wsched);
|
|
|
|
return;
|
|
|
|
error:
|
|
v9fs_mux_cancel(m, err);
|
|
clear_bit(Rworksched, &m->wsched);
|
|
}
|
|
|
|
/**
|
|
* v9fs_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 succesfully. 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 v9fs_req *v9fs_send_request(struct v9fs_mux_data *m,
|
|
struct v9fs_fcall *tc,
|
|
v9fs_mux_req_callback cb, void *cba)
|
|
{
|
|
int n;
|
|
struct v9fs_req *req;
|
|
|
|
dprintk(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 v9fs_req), GFP_KERNEL);
|
|
if (!req)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (tc->id == TVERSION)
|
|
n = V9FS_NOTAG;
|
|
else
|
|
n = v9fs_mux_get_tag(m);
|
|
|
|
if (n < 0)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
v9fs_set_tag(tc, n);
|
|
if ((v9fs_debug_level&DEBUG_FCALL) == DEBUG_FCALL) {
|
|
char buf[150];
|
|
|
|
v9fs_printfcall(buf, sizeof(buf), tc, *m->extended);
|
|
printk(KERN_NOTICE "<<< %p %s\n", m, buf);
|
|
}
|
|
|
|
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(v9fs_mux_wq, &m->wq);
|
|
|
|
return req;
|
|
}
|
|
|
|
static void v9fs_mux_free_request(struct v9fs_mux_data *m, struct v9fs_req *req)
|
|
{
|
|
v9fs_mux_put_tag(m, req->tag);
|
|
kfree(req);
|
|
}
|
|
|
|
static void v9fs_mux_flush_cb(struct v9fs_req *freq, void *a)
|
|
{
|
|
v9fs_mux_req_callback cb;
|
|
int tag;
|
|
struct v9fs_mux_data *m;
|
|
struct v9fs_req *req, *rreq, *rptr;
|
|
|
|
m = a;
|
|
dprintk(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);
|
|
v9fs_mux_free_request(m, freq);
|
|
}
|
|
|
|
static int
|
|
v9fs_mux_flush_request(struct v9fs_mux_data *m, struct v9fs_req *req)
|
|
{
|
|
struct v9fs_fcall *fc;
|
|
struct v9fs_req *rreq, *rptr;
|
|
|
|
dprintk(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);
|
|
dprintk(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) {
|
|
dprintk(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 = v9fs_create_tflush(req->tag);
|
|
v9fs_send_request(m, fc, v9fs_mux_flush_cb, m);
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
v9fs_mux_rpc_cb(struct v9fs_req *req, void *a)
|
|
{
|
|
struct v9fs_mux_rpc *r;
|
|
|
|
dprintk(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);
|
|
}
|
|
|
|
/**
|
|
* v9fs_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
|
|
v9fs_mux_rpc(struct v9fs_mux_data *m, struct v9fs_fcall *tc,
|
|
struct v9fs_fcall **rc)
|
|
{
|
|
int err, sigpending;
|
|
unsigned long flags;
|
|
struct v9fs_req *req;
|
|
struct v9fs_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 = v9fs_send_request(m, tc, v9fs_mux_rpc_cb, &r);
|
|
if (IS_ERR(req)) {
|
|
err = PTR_ERR(req);
|
|
dprintk(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 (v9fs_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);
|
|
}
|
|
sigpending = 1;
|
|
}
|
|
|
|
if (sigpending) {
|
|
spin_lock_irqsave(¤t->sighand->siglock, flags);
|
|
recalc_sigpending();
|
|
spin_unlock_irqrestore(¤t->sighand->siglock, flags);
|
|
}
|
|
|
|
if (rc)
|
|
*rc = r.rcall;
|
|
else
|
|
kfree(r.rcall);
|
|
|
|
v9fs_mux_free_request(m, req);
|
|
if (err > 0)
|
|
err = -EIO;
|
|
|
|
return err;
|
|
}
|
|
|
|
#if 0
|
|
/**
|
|
* v9fs_mux_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 v9fs_mux_rpcnb(struct v9fs_mux_data *m, struct v9fs_fcall *tc,
|
|
v9fs_mux_req_callback cb, void *a)
|
|
{
|
|
int err;
|
|
struct v9fs_req *req;
|
|
|
|
req = v9fs_send_request(m, tc, cb, a);
|
|
if (IS_ERR(req)) {
|
|
err = PTR_ERR(req);
|
|
dprintk(DEBUG_MUX, "error %d\n", err);
|
|
return PTR_ERR(req);
|
|
}
|
|
|
|
dprintk(DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
|
|
return 0;
|
|
}
|
|
#endif /* 0 */
|
|
|
|
/**
|
|
* v9fs_mux_cancel - cancel all pending requests with error
|
|
* @m: mux data
|
|
* @err: error code
|
|
*/
|
|
void v9fs_mux_cancel(struct v9fs_mux_data *m, int err)
|
|
{
|
|
struct v9fs_req *req, *rtmp;
|
|
LIST_HEAD(cancel_list);
|
|
|
|
dprintk(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);
|
|
}
|
|
|
|
static u16 v9fs_mux_get_tag(struct v9fs_mux_data *m)
|
|
{
|
|
int tag;
|
|
|
|
tag = v9fs_get_idpool(&m->tagpool);
|
|
if (tag < 0)
|
|
return V9FS_NOTAG;
|
|
else
|
|
return (u16) tag;
|
|
}
|
|
|
|
static void v9fs_mux_put_tag(struct v9fs_mux_data *m, u16 tag)
|
|
{
|
|
if (tag != V9FS_NOTAG && v9fs_check_idpool(tag, &m->tagpool))
|
|
v9fs_put_idpool(tag, &m->tagpool);
|
|
}
|
|
|