1 files changed, 131 insertions, 91 deletions

diff --git a/fs/9p/mux.c b/fs/9p/mux.c
index 3e5b124a7212..f4407eb276c7 100644
--- a/fs/9p/mux.c
+++ b/fs/9p/mux.c
@@ -50,15 +50,23 @@ 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;
 };
 
@@ -96,8 +104,8 @@ 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;
 };
@@ -524,10 +532,9 @@ 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;
@@ -553,23 +560,6 @@ 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);
 }
 
 /**
@@ -669,17 +659,26 @@ 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",
@@ -746,7 +745,6 @@ 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];
 
@@ -754,12 +752,14 @@ static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m,
                 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);
@@ -776,72 +776,108 @@ static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m,
         return req;
 }
 
-static 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);
+
+                wake_up(&m->equeue);
+        }
 
-        v9fs_mux_put_tag(m, tag);
-        kfree(tc);
-        kfree(rc);
+        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);
 }
 
@@ -856,12 +892,13 @@ 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);
@@ -869,48 +906,50 @@ 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);
+                }
+                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;
 }
@@ -951,12 +990,15 @@ 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) {
@@ -965,11 +1007,9 @@ 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);