fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / fs / 9p / mux.c
index ea1134e..147ceef 100644 (file)
@@ -7,9 +7,8 @@
  *  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"
@@ -50,15 +49,23 @@ enum {
        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;
 };
 
@@ -69,7 +76,7 @@ struct v9fs_mux_data {
        int msize;
        unsigned char *extended;
        struct v9fs_transport *trans;
-       struct v9fs_idpool tidpool;
+       struct v9fs_idpool tagpool;
        int err;
        wait_queue_head_t equeue;
        struct list_head req_list;
@@ -96,21 +103,21 @@ struct v9fs_mux_poll_task {
 
 struct v9fs_mux_rpc {
        struct v9fs_mux_data *m;
-       struct v9fs_req *req;
        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_read_work(struct work_struct *work);
+static void v9fs_write_work(struct work_struct *work);
 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 DECLARE_MUTEX(v9fs_mux_task_lock);
+static DEFINE_MUTEX(v9fs_mux_task_lock);
 static struct workqueue_struct *v9fs_mux_wq;
 
 static int v9fs_mux_num;
@@ -125,8 +132,10 @@ int v9fs_mux_global_init(void)
                v9fs_mux_poll_tasks[i].task = NULL;
 
        v9fs_mux_wq = create_workqueue("v9fs");
-       if (!v9fs_mux_wq)
+       if (!v9fs_mux_wq) {
+               printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
                return -ENOMEM;
+       }
 
        return 0;
 }
@@ -142,7 +151,7 @@ void v9fs_mux_global_exit(void)
  *
  * The current implementation returns sqrt of the number of mounts.
  */
-inline int v9fs_mux_calc_poll_procs(int muxnum)
+static int v9fs_mux_calc_poll_procs(int muxnum)
 {
        int n;
 
@@ -166,7 +175,7 @@ static int v9fs_mux_poll_start(struct v9fs_mux_data *m)
 
        dprintk(DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, v9fs_mux_num,
                v9fs_mux_poll_task_num);
-       up(&v9fs_mux_task_lock);
+       mutex_lock(&v9fs_mux_task_lock);
 
        n = v9fs_mux_calc_poll_procs(v9fs_mux_num + 1);
        if (n > v9fs_mux_poll_task_num) {
@@ -225,7 +234,7 @@ static int v9fs_mux_poll_start(struct v9fs_mux_data *m)
        }
 
        v9fs_mux_num++;
-       down(&v9fs_mux_task_lock);
+       mutex_unlock(&v9fs_mux_task_lock);
 
        return 0;
 }
@@ -235,7 +244,7 @@ static void v9fs_mux_poll_stop(struct v9fs_mux_data *m)
        int i;
        struct v9fs_mux_poll_task *vpt;
 
-       up(&v9fs_mux_task_lock);
+       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++) {
@@ -252,7 +261,7 @@ static void v9fs_mux_poll_stop(struct v9fs_mux_data *m)
                v9fs_mux_poll_task_num--;
        }
        v9fs_mux_num--;
-       down(&v9fs_mux_task_lock);
+       mutex_unlock(&v9fs_mux_task_lock);
 }
 
 /**
@@ -279,8 +288,8 @@ struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
        m->msize = msize;
        m->extended = extended;
        m->trans = trans;
-       idr_init(&m->tidpool.pool);
-       init_MUTEX(&m->tidpool.lock);
+       idr_init(&m->tagpool.pool);
+       init_MUTEX(&m->tagpool.lock);
        m->err = 0;
        init_waitqueue_head(&m->equeue);
        INIT_LIST_HEAD(&m->req_list);
@@ -290,8 +299,8 @@ struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
        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);
+       INIT_WORK(&m->rq, v9fs_read_work);
+       INIT_WORK(&m->wq, v9fs_write_work);
        m->wsched = 0;
        memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
        m->poll_task = NULL;
@@ -383,7 +392,7 @@ v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address,
 /**
  * v9fs_poll_mux - polls a mux and schedules read or write works if necessary
  */
-static inline void v9fs_poll_mux(struct v9fs_mux_data *m)
+static void v9fs_poll_mux(struct v9fs_mux_data *m)
 {
        int n;
 
@@ -451,13 +460,13 @@ static int v9fs_poll_proc(void *a)
 /**
  * v9fs_write_work - called when a transport can send some data
  */
-static void v9fs_write_work(void *a)
+static void v9fs_write_work(struct work_struct *work)
 {
        int n, err;
        struct v9fs_mux_data *m;
        struct v9fs_req *req;
 
-       m = a;
+       m = container_of(work, struct v9fs_mux_data, wq);
 
        if (m->err < 0) {
                clear_bit(Wworksched, &m->wsched);
@@ -524,10 +533,9 @@ again:
 
 static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req)
 {
-       int ecode, tag;
+       int ecode;
        struct v9fs_str *ename;
 
-       tag = req->tag;
        if (!req->err && req->rcall->id == RERROR) {
                ecode = req->rcall->params.rerror.errno;
                ename = &req->rcall->params.rerror.error;
@@ -553,29 +561,12 @@ static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req)
                if (!req->err)
                        req->err = -EIO;
        }
-
-       if (req->err == ERREQFLUSH)
-               return;
-
-       if (req->cb) {
-               dprintk(DEBUG_MUX, "calling callback tcall %p rcall %p\n",
-                       req->tcall, req->rcall);
-
-               (*req->cb) (req->cba, req->tcall, req->rcall, req->err);
-               req->cb = NULL;
-       } else
-               kfree(req->rcall);
-
-       v9fs_mux_put_tag(m, tag);
-
-       wake_up(&m->equeue);
-       kfree(req);
 }
 
 /**
  * v9fs_read_work - called when there is some data to be read from a transport
  */
-static void v9fs_read_work(void *a)
+static void v9fs_read_work(struct work_struct *work)
 {
        int n, err;
        struct v9fs_mux_data *m;
@@ -583,7 +574,7 @@ static void v9fs_read_work(void *a)
        struct v9fs_fcall *rcall;
        char *rbuf;
 
-       m = a;
+       m = container_of(work, struct v9fs_mux_data, rq);
 
        if (m->err < 0)
                return;
@@ -634,6 +625,14 @@ static void v9fs_read_work(void *a)
                        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) {
@@ -661,17 +660,26 @@ static void v9fs_read_work(void *a)
                list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
                        if (rreq->tag == rcall->tag) {
                                req = rreq;
-                               req->rcall = rcall;
-                               list_del(&req->req_list);
-                               spin_unlock(&m->lock);
-                               process_request(m, req);
+                               if (req->flush != Flushing)
+                                       list_del(&req->req_list);
                                break;
                        }
-
                }
+               spin_unlock(&m->lock);
 
-               if (!req) {
-                       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",
@@ -705,7 +713,7 @@ static void v9fs_read_work(void *a)
  * 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
+ * a guarantee that the request is sent successfully. Can return errors
  * that can be retrieved by PTR_ERR macros.
  *
  * @m: mux data
@@ -738,13 +746,21 @@ static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m,
                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);
@@ -761,73 +777,108 @@ static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m,
        return req;
 }
 
-static inline void
-v9fs_mux_flush_cb(void *a, struct v9fs_fcall *tc, struct v9fs_fcall *rc,
-                 int err)
+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, *rptr;
+       struct v9fs_req *req, *rreq, *rptr;
 
        m = a;
-       dprintk(DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m, tc,
-               rc, err, tc->params.tflush.oldtag);
+       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 = tc->params.tflush.oldtag;
-       list_for_each_entry_safe(req, rptr, &m->req_list, req_list) {
-               if (req->tag == tag) {
+       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);
-                       if (req->cb) {
-                               cb = req->cb;
-                               req->cb = NULL;
-                               spin_unlock(&m->lock);
-                               (*cb) (req->cba, req->tcall, req->rcall,
-                                      req->err);
-                       }
-                       kfree(req);
-                       wake_up(&m->equeue);
                        break;
                }
        }
+       spin_unlock(&m->lock);
 
-       if (!cb)
-               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);
 
-       v9fs_mux_put_tag(m, tag);
-       kfree(tc);
-       kfree(rc);
+               wake_up(&m->equeue);
+       }
+
+       kfree(freq->tcall);
+       kfree(freq->rcall);
+       v9fs_mux_free_request(m, freq);
 }
 
-static void
+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(void *a, struct v9fs_fcall *tc, struct v9fs_fcall *rc, int err)
+v9fs_mux_rpc_cb(struct v9fs_req *req, void *a)
 {
        struct v9fs_mux_rpc *r;
 
-       if (err == ERREQFLUSH) {
-               kfree(rc);
-               dprintk(DEBUG_MUX, "err req flush\n");
-               return;
-       }
-
+       dprintk(DEBUG_MUX, "req %p r %p\n", req, a);
        r = a;
-       dprintk(DEBUG_MUX, "mux %p req %p tc %p rc %p err %d\n", r->m, r->req,
-               tc, rc, err);
-       r->rcall = rc;
-       r->err = err;
+       r->rcall = req->rcall;
+       r->err = req->err;
+
+       if (req->flush!=None && !req->err)
+               r->err = -ERESTARTSYS;
+
        wake_up(&r->wqueue);
 }
 
@@ -842,12 +893,13 @@ int
 v9fs_mux_rpc(struct v9fs_mux_data *m, struct v9fs_fcall *tc,
             struct v9fs_fcall **rc)
 {
-       int err;
+       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);
@@ -855,52 +907,57 @@ v9fs_mux_rpc(struct v9fs_mux_data *m, struct v9fs_fcall *tc,
        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 PTR_ERR(req);
+               return err;
        }
 
-       r.req = req;
-       dprintk(DEBUG_MUX, "mux %p tc %p tag %d rpc %p req %p\n", m, tc,
-               req->tag, &r, req);
        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) {
-               spin_lock(&m->lock);
-               req->tcall = NULL;
-               req->err = ERREQFLUSH;
-               spin_unlock(&m->lock);
+               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;
+       }
 
-               clear_thread_flag(TIF_SIGPENDING);
-               v9fs_mux_flush_request(m, req);
+       if (sigpending) {
                spin_lock_irqsave(&current->sighand->siglock, flags);
                recalc_sigpending();
                spin_unlock_irqrestore(&current->sighand->siglock, flags);
        }
 
-       if (!err) {
-               if (r.rcall)
-                       dprintk(DEBUG_MUX, "got response id %d tag %d\n",
-                               r.rcall->id, r.rcall->tag);
-
-               if (rc)
-                       *rc = r.rcall;
-               else
-                       kfree(r.rcall);
-       } else {
+       if (rc)
+               *rc = r.rcall;
+       else
                kfree(r.rcall);
-               dprintk(DEBUG_MUX, "got error %d\n", err);
-               if (err > 0)
-                       err = -EIO;
-       }
+
+       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
@@ -924,6 +981,7 @@ int v9fs_mux_rpcnb(struct v9fs_mux_data *m, struct v9fs_fcall *tc,
        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
@@ -935,12 +993,15 @@ void v9fs_mux_cancel(struct v9fs_mux_data *m, int err)
        struct v9fs_req *req, *rtmp;
        LIST_HEAD(cancel_list);
 
-       dprintk(DEBUG_MUX, "mux %p err %d\n", m, err);
+       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) {
@@ -949,11 +1010,9 @@ void v9fs_mux_cancel(struct v9fs_mux_data *m, int err)
                        req->err = err;
 
                if (req->cb)
-                       (*req->cb) (req->cba, req->tcall, req->rcall, req->err);
+                       (*req->cb) (req, req->cba);
                else
                        kfree(req->rcall);
-
-               kfree(req);
        }
 
        wake_up(&m->equeue);
@@ -963,7 +1022,7 @@ static u16 v9fs_mux_get_tag(struct v9fs_mux_data *m)
 {
        int tag;
 
-       tag = v9fs_get_idpool(&m->tidpool);
+       tag = v9fs_get_idpool(&m->tagpool);
        if (tag < 0)
                return V9FS_NOTAG;
        else
@@ -972,6 +1031,6 @@ static u16 v9fs_mux_get_tag(struct v9fs_mux_data *m)
 
 static void v9fs_mux_put_tag(struct v9fs_mux_data *m, u16 tag)
 {
-       if (tag != V9FS_NOTAG && v9fs_check_idpool(tag, &m->tidpool))
-               v9fs_put_idpool(tag, &m->tidpool);
+       if (tag != V9FS_NOTAG && v9fs_check_idpool(tag, &m->tagpool))
+               v9fs_put_idpool(tag, &m->tagpool);
 }