* Protocol Multiplexer
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
- * Copyright (C) 2004 by Latchesar Ionkov <lucho@ionkov.net>
+ * 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 as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * 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
*
*/
-#include <linux/config.h>
#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 "debug.h"
#include "v9fs.h"
#include "9p.h"
-#include "transport.h"
#include "conv.h"
+#include "transport.h"
#include "mux.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 v9fs_mux_poll_task;
+
+struct v9fs_req {
+ spinlock_t lock;
+ int tag;
+ struct v9fs_fcall *tcall;
+ struct v9fs_fcall *rcall;
+ int err;
+ v9fs_mux_req_callback cb;
+ void *cba;
+ int flush;
+ struct list_head req_list;
+};
+
+struct v9fs_mux_data {
+ spinlock_t lock;
+ struct list_head mux_list;
+ struct v9fs_mux_poll_task *poll_task;
+ int msize;
+ unsigned char *extended;
+ struct v9fs_transport *trans;
+ struct v9fs_idpool tagpool;
+ int err;
+ wait_queue_head_t equeue;
+ struct list_head req_list;
+ struct list_head unsent_req_list;
+ struct v9fs_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 v9fs_mux_poll_task {
+ struct task_struct *task;
+ struct list_head mux_list;
+ int muxnum;
+};
+
+struct v9fs_mux_rpc {
+ struct v9fs_mux_data *m;
+ int err;
+ struct v9fs_fcall *tcall;
+ struct v9fs_fcall *rcall;
+ wait_queue_head_t wqueue;
+};
+
+static int v9fs_poll_proc(void *);
+static void v9fs_read_work(void *);
+static void v9fs_write_work(void *);
+static void v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address,
+ poll_table * p);
+static u16 v9fs_mux_get_tag(struct v9fs_mux_data *);
+static void v9fs_mux_put_tag(struct v9fs_mux_data *, u16);
+
+static DEFINE_MUTEX(v9fs_mux_task_lock);
+static struct workqueue_struct *v9fs_mux_wq;
+
+static int v9fs_mux_num;
+static int v9fs_mux_poll_task_num;
+static struct v9fs_mux_poll_task v9fs_mux_poll_tasks[100];
+
+int v9fs_mux_global_init(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++)
+ v9fs_mux_poll_tasks[i].task = NULL;
+
+ v9fs_mux_wq = create_workqueue("v9fs");
+ if (!v9fs_mux_wq)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void v9fs_mux_global_exit(void)
+{
+ destroy_workqueue(v9fs_mux_wq);
+}
+
/**
- * dprintcond - print condition of session info
- * @v9ses: session info structure
- * @req: RPC request structure
+ * v9fs_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 v9fs_mux_calc_poll_procs(int muxnum)
+{
+ int n;
+
+ if (v9fs_mux_poll_task_num)
+ n = muxnum / v9fs_mux_poll_task_num +
+ (muxnum % v9fs_mux_poll_task_num ? 1 : 0);
+ else
+ n = 1;
+
+ if (n > ARRAY_SIZE(v9fs_mux_poll_tasks))
+ n = ARRAY_SIZE(v9fs_mux_poll_tasks);
-static inline int
-dprintcond(struct v9fs_session_info *v9ses, struct v9fs_rpcreq *req)
+ return n;
+}
+
+static int v9fs_mux_poll_start(struct v9fs_mux_data *m)
{
- dprintk(DEBUG_MUX, "condition: %d, %p\n", v9ses->transport->status,
- req->rcall);
+ int i, n;
+ struct v9fs_mux_poll_task *vpt, *vptlast;
+ struct task_struct *pproc;
+
+ dprintk(DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, v9fs_mux_num,
+ v9fs_mux_poll_task_num);
+ mutex_lock(&v9fs_mux_task_lock);
+
+ n = v9fs_mux_calc_poll_procs(v9fs_mux_num + 1);
+ if (n > v9fs_mux_poll_task_num) {
+ for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++) {
+ if (v9fs_mux_poll_tasks[i].task == NULL) {
+ vpt = &v9fs_mux_poll_tasks[i];
+ dprintk(DEBUG_MUX, "create proc %p\n", vpt);
+ pproc = kthread_create(v9fs_poll_proc, vpt,
+ "v9fs-poll");
+
+ if (!IS_ERR(pproc)) {
+ vpt->task = pproc;
+ INIT_LIST_HEAD(&vpt->mux_list);
+ vpt->muxnum = 0;
+ v9fs_mux_poll_task_num++;
+ wake_up_process(vpt->task);
+ }
+ break;
+ }
+ }
+
+ if (i >= ARRAY_SIZE(v9fs_mux_poll_tasks))
+ dprintk(DEBUG_ERROR, "warning: no free poll slots\n");
+ }
+
+ n = (v9fs_mux_num + 1) / v9fs_mux_poll_task_num +
+ ((v9fs_mux_num + 1) % v9fs_mux_poll_task_num ? 1 : 0);
+
+ vptlast = NULL;
+ for (i = 0; i < ARRAY_SIZE(v9fs_mux_poll_tasks); i++) {
+ vpt = &v9fs_mux_poll_tasks[i];
+ if (vpt->task != NULL) {
+ vptlast = vpt;
+ if (vpt->muxnum < n) {
+ dprintk(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, v9fs_pollwait);
+ break;
+ }
+ }
+ }
+
+ if (i >= ARRAY_SIZE(v9fs_mux_poll_tasks)) {
+ if (vptlast == NULL)
+ return -ENOMEM;
+
+ dprintk(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, v9fs_pollwait);
+ }
+
+ v9fs_mux_num++;
+ mutex_unlock(&v9fs_mux_task_lock);
+
return 0;
}
+static void v9fs_mux_poll_stop(struct v9fs_mux_data *m)
+{
+ int i;
+ struct v9fs_mux_poll_task *vpt;
+
+ mutex_lock(&v9fs_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) {
+ dprintk(DEBUG_MUX, "destroy proc %p\n", vpt);
+ send_sig(SIGKILL, vpt->task, 1);
+ vpt->task = NULL;
+ v9fs_mux_poll_task_num--;
+ }
+ v9fs_mux_num--;
+ mutex_unlock(&v9fs_mux_task_lock);
+}
+
/**
- * xread - force read of a certain number of bytes
- * @v9ses: session info structure
- * @ptr: pointer to buffer
- * @sz: number of bytes to read
+ * v9fs_mux_init - allocate and initialize the per-session mux data
+ * Creates the polling task if this is the first session.
*
- * Chuck Cranor CS-533 project1
+ * @trans - transport structure
+ * @msize - maximum message size
+ * @extended - pointer to the extended flag
*/
-
-static int xread(struct v9fs_session_info *v9ses, void *ptr, unsigned long sz)
+struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
+ unsigned char *extended)
{
- int rd = 0;
- int ret = 0;
- while (rd < sz) {
- ret = v9ses->transport->read(v9ses->transport, ptr, sz - rd);
- if (ret <= 0) {
- dprintk(DEBUG_ERROR, "xread errno %d\n", ret);
- return ret;
+ int i, n;
+ struct v9fs_mux_data *m, *mtmp;
+
+ dprintk(DEBUG_MUX, "transport %p msize %d\n", trans, msize);
+ m = kmalloc(sizeof(struct v9fs_mux_data), 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;
+ idr_init(&m->tagpool.pool);
+ init_MUTEX(&m->tagpool.lock);
+ 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, v9fs_read_work, m);
+ INIT_WORK(&m->wq, v9fs_write_work, m);
+ m->wsched = 0;
+ memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
+ m->poll_task = NULL;
+ n = v9fs_mux_poll_start(m);
+ if (n)
+ return ERR_PTR(n);
+
+ n = trans->poll(trans, &m->pt);
+ if (n & POLLIN) {
+ dprintk(DEBUG_MUX, "mux %p can read\n", m);
+ set_bit(Rpending, &m->wsched);
+ }
+
+ if (n & POLLOUT) {
+ dprintk(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])) {
+ v9fs_mux_poll_stop(m);
+ mtmp = (void *)m->poll_waddr; /* the error code */
+ kfree(m);
+ m = mtmp;
+ break;
}
- rd += ret;
- ptr += ret;
}
- return (rd);
+
+ return m;
}
/**
- * read_message - read a full 9P2000 fcall packet
- * @v9ses: session info structure
- * @rcall: fcall structure to read into
- * @rcalllen: size of fcall buffer
- *
+ * v9fs_mux_destroy - cancels all pending requests and frees mux resources
*/
+void v9fs_mux_destroy(struct v9fs_mux_data *m)
+{
+ dprintk(DEBUG_MUX, "mux %p prev %p next %p\n", m,
+ m->mux_list.prev, m->mux_list.next);
+ v9fs_mux_cancel(m, -ECONNRESET);
+
+ if (!list_empty(&m->req_list)) {
+ /* wait until all processes waiting on this session exit */
+ dprintk(DEBUG_MUX, "mux %p waiting for empty request queue\n",
+ m);
+ wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000);
+ dprintk(DEBUG_MUX, "mux %p request queue empty: %d\n", m,
+ list_empty(&m->req_list));
+ }
-static int
-read_message(struct v9fs_session_info *v9ses,
- struct v9fs_fcall *rcall, int rcalllen)
+ v9fs_mux_poll_stop(m);
+ m->trans = NULL;
+
+ kfree(m);
+}
+
+/**
+ * v9fs_pollwait - called by files poll operation to add v9fs-poll task
+ * to files wait queue
+ */
+static void
+v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address,
+ poll_table * p)
{
- unsigned char buf[4];
- void *data;
- int size = 0;
- int res = 0;
+ int i;
+ struct v9fs_mux_data *m;
- res = xread(v9ses, buf, sizeof(buf));
- if (res < 0) {
- dprintk(DEBUG_ERROR,
- "Reading of count field failed returned: %d\n", res);
- return res;
+ m = container_of(p, struct v9fs_mux_data, 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)) {
+ dprintk(DEBUG_ERROR, "not enough wait_address slots\n");
+ return;
}
- if (res < 4) {
- dprintk(DEBUG_ERROR,
- "Reading of count field failed returned: %d\n", res);
- return -EIO;
+ m->poll_waddr[i] = wait_address;
+
+ if (!wait_address) {
+ dprintk(DEBUG_ERROR, "no wait_address\n");
+ m->poll_waddr[i] = ERR_PTR(-EIO);
+ return;
}
- size = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
- dprintk(DEBUG_MUX, "got a packet count: %d\n", size);
+ init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
+ add_wait_queue(wait_address, &m->poll_wait[i]);
+}
+
+/**
+ * v9fs_poll_mux - polls a mux and schedules read or write works if necessary
+ */
+static void v9fs_poll_mux(struct v9fs_mux_data *m)
+{
+ int n;
- /* adjust for the four bytes of size */
- size -= 4;
+ if (m->err < 0)
+ return;
- if (size > v9ses->maxdata) {
- dprintk(DEBUG_ERROR, "packet too big: %d\n", size);
- return -E2BIG;
+ n = m->trans->poll(m->trans, NULL);
+ if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
+ dprintk(DEBUG_MUX, "error mux %p err %d\n", m, n);
+ if (n >= 0)
+ n = -ECONNRESET;
+ v9fs_mux_cancel(m, n);
}
- data = kmalloc(size, GFP_KERNEL);
- if (!data) {
- eprintk(KERN_WARNING, "out of memory\n");
- return -ENOMEM;
+ if (n & POLLIN) {
+ set_bit(Rpending, &m->wsched);
+ dprintk(DEBUG_MUX, "mux %p can read\n", m);
+ if (!test_and_set_bit(Rworksched, &m->wsched)) {
+ dprintk(DEBUG_MUX, "schedule read work mux %p\n", m);
+ queue_work(v9fs_mux_wq, &m->rq);
+ }
}
- res = xread(v9ses, data, size);
- if (res < size) {
- dprintk(DEBUG_ERROR, "Reading of fcall failed returned: %d\n",
- res);
- kfree(data);
- return res;
+ if (n & POLLOUT) {
+ set_bit(Wpending, &m->wsched);
+ dprintk(DEBUG_MUX, "mux %p can write\n", m);
+ if ((m->wsize || !list_empty(&m->unsent_req_list))
+ && !test_and_set_bit(Wworksched, &m->wsched)) {
+ dprintk(DEBUG_MUX, "schedule write work mux %p\n", m);
+ queue_work(v9fs_mux_wq, &m->wq);
+ }
}
+}
- /* we now have an in-memory string that is the reply.
- * deserialize it. There is very little to go wrong at this point
- * save for v9fs_alloc errors.
- */
- res = v9fs_deserialize_fcall(v9ses, size, data, v9ses->maxdata,
- rcall, rcalllen);
+/**
+ * v9fs_poll_proc - polls all v9fs transports for new events and queues
+ * the appropriate work to the work queue
+ */
+static int v9fs_poll_proc(void *a)
+{
+ struct v9fs_mux_data *m, *mtmp;
+ struct v9fs_mux_poll_task *vpt;
+
+ vpt = a;
+ dprintk(DEBUG_MUX, "start %p %p\n", current, vpt);
+ allow_signal(SIGKILL);
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (signal_pending(current))
+ break;
- kfree(data);
+ list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
+ v9fs_poll_mux(m);
+ }
- if (res < 0)
- return res;
+ dprintk(DEBUG_MUX, "sleeping...\n");
+ schedule_timeout(SCHED_TIMEOUT * HZ);
+ }
+ __set_current_state(TASK_RUNNING);
+ dprintk(DEBUG_MUX, "finish\n");
return 0;
}
/**
- * v9fs_recv - receive an RPC response for a particular tag
- * @v9ses: session info structure
- * @req: RPC request structure
- *
+ * v9fs_write_work - called when a transport can send some data
*/
-
-static int v9fs_recv(struct v9fs_session_info *v9ses, struct v9fs_rpcreq *req)
+static void v9fs_write_work(void *a)
{
- int ret = 0;
+ int n, err;
+ struct v9fs_mux_data *m;
+ struct v9fs_req *req;
- dprintk(DEBUG_MUX, "waiting for response: %d\n", req->tcall->tag);
- ret = wait_event_interruptible(v9ses->read_wait,
- ((v9ses->transport->status != Connected) ||
- (req->rcall != 0) || dprintcond(v9ses, req)));
+ m = a;
- dprintk(DEBUG_MUX, "got it: rcall %p\n", req->rcall);
- if (v9ses->transport->status == Disconnected)
- return -ECONNRESET;
+ if (m->err < 0) {
+ clear_bit(Wworksched, &m->wsched);
+ return;
+ }
- if (ret == 0) {
- spin_lock(&v9ses->muxlock);
- list_del(&req->next);
- spin_unlock(&v9ses->muxlock);
+ 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 v9fs_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;
+ dump_data(m->wbuf, m->wsize);
+ spin_unlock(&m->lock);
}
- return ret;
-}
+ 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;
+ }
-/**
- * v9fs_send - send a 9P request
- * @v9ses: session info structure
- * @req: RPC request to send
- *
- */
+ if (err <= 0)
+ goto error;
-static int v9fs_send(struct v9fs_session_info *v9ses, struct v9fs_rpcreq *req)
-{
- int ret = -1;
- void *data = NULL;
- struct v9fs_fcall *tcall = req->tcall;
+ m->wpos += err;
+ if (m->wpos == m->wsize)
+ m->wpos = m->wsize = 0;
- data = kmalloc(v9ses->maxdata + V9FS_IOHDRSZ, GFP_KERNEL);
- if (!data)
- return -ENOMEM;
+ 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);
- tcall->size = 0; /* enforce size recalculation */
- ret =
- v9fs_serialize_fcall(v9ses, tcall, data,
- v9ses->maxdata + V9FS_IOHDRSZ);
- if (ret < 0)
- goto free_data;
-
- spin_lock(&v9ses->muxlock);
- list_add(&req->next, &v9ses->mux_fcalls);
- spin_unlock(&v9ses->muxlock);
-
- dprintk(DEBUG_MUX, "sending message: tag %d size %d\n", tcall->tag,
- tcall->size);
- ret = v9ses->transport->write(v9ses->transport, data, tcall->size);
-
- if (ret != tcall->size) {
- spin_lock(&v9ses->muxlock);
- list_del(&req->next);
- kfree(req->rcall);
-
- spin_unlock(&v9ses->muxlock);
- if (ret >= 0)
- ret = -EREMOTEIO;
+ 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
- ret = 0;
+ clear_bit(Wworksched, &m->wsched);
- free_data:
- kfree(data);
- return ret;
+ 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_mux_rpc - send a request, receive a response
- * @v9ses: session info structure
- * @tcall: fcall to send
- * @rcall: buffer to place response into
- *
+ * v9fs_read_work - called when there is some data to be read from a transport
*/
-
-long
-v9fs_mux_rpc(struct v9fs_session_info *v9ses, struct v9fs_fcall *tcall,
- struct v9fs_fcall **rcall)
+static void v9fs_read_work(void *a)
{
- int tid = -1;
- struct v9fs_fcall *fcall = NULL;
- struct v9fs_rpcreq req;
- int ret = -1;
-
- if (!v9ses)
- return -EINVAL;
+ 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;
+ }
- if (rcall)
- *rcall = NULL;
+ m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall);
+ m->rpos = 0;
+ }
- if (tcall->id != TVERSION) {
- tid = v9fs_get_idpool(&v9ses->tidpool);
- if (tid < 0)
- return -ENOMEM;
+ 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;
}
- tcall->tag = tid;
+ if (err <= 0)
+ goto error;
- req.tcall = tcall;
- req.rcall = NULL;
+ 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;
+ }
- ret = v9fs_send(v9ses, &req);
+ if (m->rpos < n)
+ break;
- if (ret < 0) {
- if (tcall->id != TVERSION)
- v9fs_put_idpool(tid, &v9ses->tidpool);
- dprintk(DEBUG_MUX, "error %d\n", ret);
- return ret;
- }
+ 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];
- ret = v9fs_recv(v9ses, &req);
+ 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;
+ }
- fcall = req.rcall;
+ 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, "received: tag=%x, ret=%d\n", tcall->tag, ret);
- if (ret == -ERESTARTSYS) {
- if (v9ses->transport->status != Disconnected
- && tcall->id != TFLUSH) {
- unsigned long flags;
+ dprintk(DEBUG_MUX, "mux %p fcall id %d tag %d\n", m, rcall->id,
+ rcall->tag);
- dprintk(DEBUG_MUX, "flushing the tag: %d\n",
- tcall->tag);
- clear_thread_flag(TIF_SIGPENDING);
- v9fs_t_flush(v9ses, tcall->tag);
- spin_lock_irqsave(¤t->sighand->siglock, flags);
- recalc_sigpending();
- spin_unlock_irqrestore(¤t->sighand->siglock,
- flags);
- dprintk(DEBUG_MUX, "flushing done\n");
+ 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);
- goto release_req;
- } else if (ret < 0)
- goto release_req;
-
- if (!fcall)
- ret = -EIO;
- else {
- if (fcall->id == RERROR) {
- ret = v9fs_errstr2errno(fcall->params.rerror.error);
- if (ret == 0) { /* string match failed */
- if (fcall->params.rerror.errno)
- ret = -(fcall->params.rerror.errno);
+ if (req) {
+ req->rcall = rcall;
+ process_request(m, req);
+
+ if (req->flush != Flushing) {
+ if (req->cb)
+ (*req->cb) (req, req->cba);
else
- ret = -ESERVERFAULT;
+ kfree(req->rcall);
+
+ wake_up(&m->equeue);
}
- } else if (fcall->id != tcall->id + 1) {
- dprintk(DEBUG_ERROR,
- "fcall mismatch: expected %d, got %d\n",
- tcall->id + 1, fcall->id);
- ret = -EIO;
+ } 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);
}
}
- release_req:
- if (tcall->id != TVERSION)
- v9fs_put_idpool(tid, &v9ses->tidpool);
- if (rcall)
- *rcall = fcall;
- else
- kfree(fcall);
+ 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 ret;
+ return;
+
+ error:
+ v9fs_mux_cancel(m, err);
+ clear_bit(Rworksched, &m->wsched);
}
/**
- * v9fs_mux_cancel_requests - cancels all pending requests
+ * 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 successfully. Can return errors
+ * that can be retrieved by PTR_ERR macros.
*
- * @v9ses: session info structure
- * @err: error code to return to the requests
+ * @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
*/
-void v9fs_mux_cancel_requests(struct v9fs_session_info *v9ses, int err)
+static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m,
+ struct v9fs_fcall *tc,
+ v9fs_mux_req_callback cb, void *cba)
{
- struct v9fs_rpcreq *rptr;
- struct v9fs_rpcreq *rreq;
+ 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];
- dprintk(DEBUG_MUX, " %d\n", err);
- spin_lock(&v9ses->muxlock);
- list_for_each_entry_safe(rreq, rptr, &v9ses->mux_fcalls, next) {
- rreq->err = err;
+ v9fs_printfcall(buf, sizeof(buf), tc, *m->extended);
+ printk(KERN_NOTICE "<<< %p %s\n", m, buf);
}
- spin_unlock(&v9ses->muxlock);
- wake_up_all(&v9ses->read_wait);
-}
-/**
- * v9fs_recvproc - kproc to handle demultiplexing responses
- * @data: session info structure
- *
- */
+ 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);
-static int v9fs_recvproc(void *data)
+ return req;
+}
+
+static void v9fs_mux_free_request(struct v9fs_mux_data *m, struct v9fs_req *req)
{
- struct v9fs_session_info *v9ses = (struct v9fs_session_info *)data;
- struct v9fs_fcall *rcall = NULL;
- struct v9fs_rpcreq *rptr;
- struct v9fs_rpcreq *req;
- struct v9fs_rpcreq *rreq;
- int err = 0;
+ v9fs_mux_put_tag(m, req->tag);
+ kfree(req);
+}
- allow_signal(SIGKILL);
- set_current_state(TASK_INTERRUPTIBLE);
- complete(&v9ses->proccmpl);
- while (!kthread_should_stop() && err >= 0) {
- req = rptr = rreq = NULL;
-
- rcall = kmalloc(v9ses->maxdata + V9FS_IOHDRSZ, GFP_KERNEL);
- if (!rcall) {
- eprintk(KERN_ERR, "no memory for buffers\n");
+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);
- err = read_message(v9ses, rcall, v9ses->maxdata + V9FS_IOHDRSZ);
- if (err < 0) {
- kfree(rcall);
- break;
- }
- spin_lock(&v9ses->muxlock);
- list_for_each_entry_safe(rreq, rptr, &v9ses->mux_fcalls, next) {
- if (rreq->tcall->tag == rcall->tag) {
- req = rreq;
- req->rcall = rcall;
- break;
- }
- }
+ if (req) {
+ spin_lock(&req->lock);
+ req->flush = Flushed;
+ spin_unlock(&req->lock);
- if (req && (req->tcall->id == TFLUSH)) {
- struct v9fs_rpcreq *treq = NULL;
- list_for_each_entry_safe(treq, rptr, &v9ses->mux_fcalls, next) {
- if (treq->tcall->tag ==
- req->tcall->params.tflush.oldtag) {
- list_del(&rptr->next);
- kfree(treq->rcall);
- break;
- }
- }
- }
+ if (req->cb)
+ (*req->cb) (req, req->cba);
+ else
+ kfree(req->rcall);
- spin_unlock(&v9ses->muxlock);
+ wake_up(&m->equeue);
+ }
- if (!req) {
- dprintk(DEBUG_ERROR,
- "unexpected response: id %d tag %d\n",
- rcall->id, rcall->tag);
+ kfree(freq->tcall);
+ kfree(freq->rcall);
+ v9fs_mux_free_request(m, freq);
+}
- kfree(rcall);
- }
+static int
+v9fs_mux_flush_request(struct v9fs_mux_data *m, struct v9fs_req *req)
+{
+ struct v9fs_fcall *fc;
+ struct v9fs_req *rreq, *rptr;
- wake_up_all(&v9ses->read_wait);
- set_current_state(TASK_INTERRUPTIBLE);
+ 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;
}
- /* Inform all pending processes about the failure */
- wake_up_all(&v9ses->read_wait);
+ 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);
- if (signal_pending(current))
- complete(&v9ses->proccmpl);
+ clear_thread_flag(TIF_SIGPENDING);
+ fc = v9fs_create_tflush(req->tag);
+ v9fs_send_request(m, fc, v9fs_mux_flush_cb, m);
+ return 1;
+}
- dprintk(DEBUG_MUX, "recvproc: end\n");
- v9ses->recvproc = NULL;
+static void
+v9fs_mux_rpc_cb(struct v9fs_req *req, void *a)
+{
+ struct v9fs_mux_rpc *r;
- return err >= 0;
+ 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_init - initialize multiplexer (spawn kproc)
- * @v9ses: session info structure
- * @dev_name: mount device information (to create unique kproc)
- *
+ * 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);
+
+ err = -ERESTARTSYS;
+ }
+ sigpending = 1;
+ }
+
+ if (sigpending) {
+ spin_lock_irqsave(¤t->sighand->siglock, flags);
+ recalc_sigpending();
+ spin_unlock_irqrestore(¤t->sighand->siglock, flags);
+ }
-int v9fs_mux_init(struct v9fs_session_info *v9ses, const char *dev_name)
+ 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)
{
- char procname[60];
+ 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);
+ }
- strncpy(procname, dev_name, sizeof(procname));
- procname[sizeof(procname) - 1] = 0;
+ dprintk(DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
+ return 0;
+}
+#endif /* 0 */
- init_waitqueue_head(&v9ses->read_wait);
- init_completion(&v9ses->fcread);
- init_completion(&v9ses->proccmpl);
- spin_lock_init(&v9ses->muxlock);
- INIT_LIST_HEAD(&v9ses->mux_fcalls);
- v9ses->recvproc = NULL;
- v9ses->curfcall = NULL;
+/**
+ * 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);
- v9ses->recvproc = kthread_create(v9fs_recvproc, v9ses,
- "v9fs_recvproc %s", procname);
+ list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
+ list_del(&req->req_list);
+ if (!req->err)
+ req->err = err;
- if (IS_ERR(v9ses->recvproc)) {
- eprintk(KERN_ERR, "cannot create receiving thread\n");
- v9fs_session_close(v9ses);
- return -ECONNABORTED;
+ if (req->cb)
+ (*req->cb) (req, req->cba);
+ else
+ kfree(req->rcall);
}
- wake_up_process(v9ses->recvproc);
- wait_for_completion(&v9ses->proccmpl);
+ wake_up(&m->equeue);
+}
- return 0;
+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);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff