9p: apply common request code to trans_fd

Apply the now common p9_req_t structure to the fd transport.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

4 files changed, 126 insertions, 172 deletions

diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index 140cf1d58452..4fecaabd17bd 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -49,11 +49,12 @@ enum p9_trans_status {
  * enum p9_req_status_t - virtio request status
  * @REQ_STATUS_IDLE: request slot unused
  * @REQ_STATUS_ALLOC: request has been allocated but not sent
+ * @REQ_STATUS_UNSENT: request waiting to be sent
  * @REQ_STATUS_SENT: request sent to server
  * @REQ_STATUS_FLSH: a flush has been sent for this request
  * @REQ_STATUS_RCVD: response received from server
  * @REQ_STATUS_FLSHD: request has been flushed
- * @REQ_STATUS_ERR: request encountered an error on the client side
+ * @REQ_STATUS_ERROR: request encountered an error on the client side
  *
  * The @REQ_STATUS_IDLE state is used to mark a request slot as unused
  * but use is actually tracked by the idpool structure which handles tag
@@ -64,6 +65,7 @@ enum p9_trans_status {
 enum p9_req_status_t {
         REQ_STATUS_IDLE,
         REQ_STATUS_ALLOC,
+        REQ_STATUS_UNSENT,
         REQ_STATUS_SENT,
         REQ_STATUS_FLSH,
         REQ_STATUS_RCVD,
@@ -79,6 +81,8 @@ enum p9_req_status_t {
  * @tc: the request fcall structure
  * @rc: the response fcall structure
  * @aux: transport specific data (provided for trans_fd migration)
+ * @tag: tag on request (BUG: redundant)
+ * @req_list: link for higher level objects to chain requests
  *
  * Transport use an array to track outstanding requests
  * instead of a list.  While this may incurr overhead during initial
@@ -99,6 +103,9 @@ struct p9_req_t {
         struct p9_fcall *rc;
         u16 flush_tag;
         void *aux;
+
+        int tag;
+        struct list_head req_list;
 };
 
 /**
@@ -207,5 +214,6 @@ struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset);
 
 struct p9_req_t *p9_tag_alloc(struct p9_client *, u16);
 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
+void p9_free_req(struct p9_client *, struct p9_req_t *);
 
 #endif /* NET_9P_CLIENT_H */
diff --git a/net/9p/client.c b/net/9p/client.c
index 867031934f75..f2d07ef9e6a4 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -268,6 +268,27 @@ static void p9_tag_cleanup(struct p9_client *c)
         c->max_tag = 0;
 }
 
+/**
+ * p9_free_req - free a request and clean-up as necessary
+ * c: client state
+ * r: request to release
+ *
+ */
+
+void p9_free_req(struct p9_client *c, struct p9_req_t *r)
+{
+        r->flush_tag = P9_NOTAG;
+        r->status = REQ_STATUS_IDLE;
+        if (r->tc->tag != P9_NOTAG && p9_idpool_check(r->tc->tag, c->tagpool))
+                p9_idpool_put(r->tc->tag, c->tagpool);
+
+        /* if this was a flush request we have to free response fcall */
+        if (r->tc->id == P9_TFLUSH) {
+                kfree(r->tc);
+                kfree(r->rc);
+        }
+}
+
 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 {
         int err;
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 6243093934b2..cc9bc739e9d3 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -44,7 +44,6 @@
 
 #define P9_PORT 564
 #define MAX_SOCK_BUF (64*1024)
-#define ERREQFLUSH      1
 #define MAXPOLLWADDR    2
 
 /**
@@ -99,38 +98,6 @@ enum {
         Wpending = 8,           /* can write */
 };
 
-enum {
-        None,
-        Flushing,
-        Flushed,
-};
-
-/**
- * struct p9_req - fd mux encoding of an rpc transaction
- * @lock: protects req_list
- * @tag: numeric tag for rpc transaction
- * @tcall: request &p9_fcall structure
- * @rcall: response &p9_fcall structure
- * @err: error state
- * @flush: flag to indicate RPC has been flushed
- * @req_list: list link for higher level objects to chain requests
- * @m: connection this request was issued on
- * @wqueue: wait queue that client is blocked on for this rpc
- *
- */
-
-struct p9_req {
-        spinlock_t lock;
-        int tag;
-        struct p9_fcall *tcall;
-        struct p9_fcall *rcall;
-        int err;
-        int flush;
-        struct list_head req_list;
-        struct p9_conn *m;
-        wait_queue_head_t wqueue;
-};
-
 struct p9_poll_wait {
         struct p9_conn *conn;
         wait_queue_t wait;
@@ -139,7 +106,6 @@ struct p9_poll_wait {
 
 /**
  * struct p9_conn - fd mux connection state information
- * @lock: protects mux_list (?)
  * @mux_list: list link for mux to manage multiple connections (?)
  * @client: reference to client instance for this connection
  * @err: error state
@@ -161,7 +127,6 @@ struct p9_poll_wait {
  */
 
 struct p9_conn {
-        spinlock_t lock; /* protect lock structure */
         struct list_head mux_list;
         struct p9_client *client;
         int err;
@@ -205,64 +170,41 @@ static void p9_mux_poll_stop(struct p9_conn *m)
         spin_unlock_irqrestore(&p9_poll_lock, flags);
 }
 
-static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
-{
-        if (req->tag != P9_NOTAG &&
-            p9_idpool_check(req->tag, m->client->tagpool))
-                p9_idpool_put(req->tag, m->client->tagpool);
-        kfree(req);
-}
-
-static void p9_conn_rpc_cb(struct p9_req *req);
+static void p9_conn_rpc_cb(struct p9_client *, struct p9_req_t *);
 
-static void p9_mux_flush_cb(struct p9_req *freq)
+static void p9_mux_flush_cb(struct p9_client *client, struct p9_req_t *freq)
 {
-        int tag;
-        struct p9_conn *m = freq->m;
-        struct p9_req *req, *rreq, *rptr;
+        struct p9_conn *m = client->trans;
+        struct p9_req_t *req;
 
         P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
-                freq->tcall, freq->rcall, freq->err,
-                freq->tcall->params.tflush.oldtag);
-
-        spin_lock(&m->lock);
-        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);
+                freq->tc, freq->rc, freq->t_err,
+                freq->tc->params.tflush.oldtag);
 
+        req = p9_tag_lookup(client, freq->tc->params.tflush.oldtag);
         if (req) {
-                spin_lock(&req->lock);
-                req->flush = Flushed;
-                spin_unlock(&req->lock);
-
-                p9_conn_rpc_cb(req);
+                req->status = REQ_STATUS_FLSHD;
+                list_del(&req->req_list);
+                p9_conn_rpc_cb(client, req);
         }
 
-        kfree(freq->tcall);
-        kfree(freq->rcall);
-        p9_mux_free_request(m, freq);
+        p9_free_req(client, freq);
 }
 
-static void p9_conn_rpc_cb(struct p9_req *req)
+static void p9_conn_rpc_cb(struct p9_client *client, struct p9_req_t *req)
 {
         P9_DPRINTK(P9_DEBUG_MUX, "req %p\n", req);
 
-        if (req->tcall->id == P9_TFLUSH) { /* flush callback */
+        if (req->tc->id == P9_TFLUSH) { /* flush callback */
                 P9_DPRINTK(P9_DEBUG_MUX, "flush req %p\n", req);
-                p9_mux_flush_cb(req);
+                p9_mux_flush_cb(client, req);
         } else {                        /* normal wakeup path */
                 P9_DPRINTK(P9_DEBUG_MUX, "normal req %p\n", req);
-                if (req->flush != None && !req->err)
-                        req->err = -ERESTARTSYS;
+                if (!req->t_err && (req->status == REQ_STATUS_FLSHD ||
+                                 req->status == REQ_STATUS_FLSH))
+                        req->t_err = -ERESTARTSYS;
 
-                wake_up(&req->wqueue);
+                wake_up(req->wq);
         }
 }
 
@@ -275,59 +217,62 @@ static void p9_conn_rpc_cb(struct p9_req *req)
 
 void p9_conn_cancel(struct p9_conn *m, int err)
 {
-        struct p9_req *req, *rtmp;
+        struct p9_req_t *req, *rtmp;
         LIST_HEAD(cancel_list);
 
         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
         m->err = err;
-        spin_lock(&m->lock);
+        spin_lock(&m->client->lock);
         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
+                req->status = REQ_STATUS_ERROR;
+                if (!req->t_err)
+                        req->t_err = err;
                 list_move(&req->req_list, &cancel_list);
         }
         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
+                req->status = REQ_STATUS_ERROR;
+                if (!req->t_err)
+                        req->t_err = err;
                 list_move(&req->req_list, &cancel_list);
         }
-        spin_unlock(&m->lock);
+        spin_unlock(&m->client->lock);
 
         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
                 list_del(&req->req_list);
-                if (!req->err)
-                        req->err = err;
-
-                p9_conn_rpc_cb(req);
+                p9_conn_rpc_cb(m->client, req);
         }
 }
 
-static void process_request(struct p9_conn *m, struct p9_req *req)
+static void process_request(struct p9_conn *m, struct p9_req_t *req)
 {
         int ecode;
         struct p9_str *ename;
 
-        if (!req->err && req->rcall->id == P9_RERROR) {
-                ecode = req->rcall->params.rerror.errno;
-                ename = &req->rcall->params.rerror.error;
+        if (!req->t_err && req->rc->id == P9_RERROR) {
+                ecode = req->rc->params.rerror.errno;
+                ename = &req->rc->params.rerror.error;
 
                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
                                                                 ename->str);
 
                 if (m->client->dotu)
-                        req->err = -ecode;
+                        req->t_err = -ecode;
 
-                if (!req->err) {
-                        req->err = p9_errstr2errno(ename->str, ename->len);
+                if (!req->t_err) {
+                        req->t_err = p9_errstr2errno(ename->str, ename->len);
 
                         /* string match failed */
-                        if (!req->err) {
-                                PRINT_FCALL_ERROR("unknown error", req->rcall);
-                                req->err = -ESERVERFAULT;
+                        if (!req->t_err) {
+                                PRINT_FCALL_ERROR("unknown error", req->rc);
+                                req->t_err = -ESERVERFAULT;
                         }
                 }
-        } else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
+        } else if (req->tc && req->rc->id != req->tc->id + 1) {
                 P9_DPRINTK(P9_DEBUG_ERROR,
                                 "fcall mismatch: expected %d, got %d\n",
-                                req->tcall->id + 1, req->rcall->id);
-                if (!req->err)
-                        req->err = -EIO;
+                                req->tc->id + 1, req->rc->id);
+                if (!req->t_err)
+                        req->t_err = -EIO;
         }
 }
 
@@ -401,7 +346,7 @@ static void p9_read_work(struct work_struct *work)
 {
         int n, err;
         struct p9_conn *m;
-        struct p9_req *req, *rptr, *rreq;
+        struct p9_req_t *req;
         struct p9_fcall *rcall;
         char *rbuf;
 
@@ -488,24 +433,19 @@ static void p9_read_work(struct work_struct *work)
                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
                                                         rcall->id, rcall->tag);
 
-                req = NULL;
-                spin_lock(&m->lock);
-                list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
-                        if (rreq->tag == rcall->tag) {
-                                req = rreq;
-                                if (req->flush != Flushing)
-                                        list_del(&req->req_list);
-                                break;
-                        }
-                }
-                spin_unlock(&m->lock);
+                req = p9_tag_lookup(m->client, rcall->tag);
 
                 if (req) {
-                        req->rcall = rcall;
+                        if (req->status != REQ_STATUS_FLSH) {
+                                list_del(&req->req_list);
+                                req->status = REQ_STATUS_RCVD;
+                        }
+
+                        req->rc = rcall;
                         process_request(m, req);
 
-                        if (req->flush != Flushing)
-                                p9_conn_rpc_cb(req);
+                        if (req->status != REQ_STATUS_FLSH)
+                                p9_conn_rpc_cb(m->client, req);
                 } else {
                         if (err >= 0 && rcall->id != P9_RFLUSH)
                                 P9_DPRINTK(P9_DEBUG_ERROR,
@@ -580,7 +520,7 @@ static void p9_write_work(struct work_struct *work)
 {
         int n, err;
         struct p9_conn *m;
-        struct p9_req *req;
+        struct p9_req_t *req;
 
         m = container_of(work, struct p9_conn, wq);
 
@@ -595,18 +535,16 @@ static void p9_write_work(struct work_struct *work)
                         return;
                 }
 
-                spin_lock(&m->lock);
-again:
-                req = list_entry(m->unsent_req_list.next, struct p9_req,
+                spin_lock(&m->client->lock);
+                req = list_entry(m->unsent_req_list.next, struct p9_req_t,
                                req_list);
+                req->status = REQ_STATUS_SENT;
                 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->wbuf = req->tc->sdata;
+                m->wsize = req->tc->size;
                 m->wpos = 0;
-                spin_unlock(&m->lock);
+                spin_unlock(&m->client->lock);
         }
 
         P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
@@ -725,7 +663,6 @@ static struct p9_conn *p9_conn_create(struct p9_client *client)
         if (!m)
                 return ERR_PTR(-ENOMEM);
 
-        spin_lock_init(&m->lock);
         INIT_LIST_HEAD(&m->mux_list);
         m->client = client;
 
@@ -812,30 +749,27 @@ static void p9_poll_mux(struct p9_conn *m)
  *
  */
 
-static struct p9_req *p9_send_request(struct p9_conn *m, struct p9_fcall *tc)
+static struct p9_req_t *p9_send_request(struct p9_conn *m, struct p9_fcall *tc)
 {
+        int tag;
         int n;
-        struct p9_req *req;
+        struct p9_req_t *req;
 
         P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
                 tc, tc->id);
         if (m->err < 0)
                 return ERR_PTR(m->err);
 
-        req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
-        if (!req)
-                return ERR_PTR(-ENOMEM);
-
-        n = P9_NOTAG;
+        tag = P9_NOTAG;
         if (tc->id != P9_TVERSION) {
-                n = p9_idpool_get(m->client->tagpool);
-                if (n < 0) {
-                        kfree(req);
+                tag = p9_idpool_get(m->client->tagpool);
+                if (tag < 0)
                         return ERR_PTR(-ENOMEM);
-                }
         }
 
-        p9_set_tag(tc, n);
+        p9_set_tag(tc, tag);
+
+        req = p9_tag_alloc(m->client, tag);
 
 #ifdef CONFIG_NET_9P_DEBUG
         if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
@@ -846,18 +780,15 @@ static struct p9_req *p9_send_request(struct p9_conn *m, struct p9_fcall *tc)
         }
 #endif
 
-        spin_lock_init(&req->lock);
-        req->m = m;
-        init_waitqueue_head(&req->wqueue);
-        req->tag = n;
-        req->tcall = tc;
-        req->rcall = NULL;
-        req->err = 0;
-        req->flush = None;
+        req->tag = tag;
+        req->tc = tc;
+        req->rc = NULL;
+        req->t_err = 0;
+        req->status = REQ_STATUS_UNSENT;
 
-        spin_lock(&m->lock);
+        spin_lock(&m->client->lock);
         list_add_tail(&req->req_list, &m->unsent_req_list);
-        spin_unlock(&m->lock);
+        spin_unlock(&m->client->lock);
 
         if (test_and_clear_bit(Wpending, &m->wsched))
                 n = POLLOUT;
@@ -871,39 +802,36 @@ static struct p9_req *p9_send_request(struct p9_conn *m, struct p9_fcall *tc)
 }
 
 static int
-p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
+p9_mux_flush_request(struct p9_conn *m, struct p9_req_t *req)
 {
         struct p9_fcall *fc;
-        struct p9_req *rreq, *rptr;
+        struct p9_req_t *rreq, *rptr;
 
         P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
 
         /* if a response was received for a request, do nothing */
-        spin_lock(&req->lock);
-        if (req->rcall || req->err) {
-                spin_unlock(&req->lock);
+        if (req->rc || req->t_err) {
                 P9_DPRINTK(P9_DEBUG_MUX,
                         "mux %p req %p response already received\n", m, req);
                 return 0;
         }
 
-        req->flush = Flushing;
-        spin_unlock(&req->lock);
+        req->status = REQ_STATUS_FLSH;
 
-        spin_lock(&m->lock);
+        spin_lock(&m->client->lock);
         /* if the request is not sent yet, just remove it from the list */
         list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
                 if (rreq->tag == req->tag) {
                         P9_DPRINTK(P9_DEBUG_MUX,
                            "mux %p req %p request is not sent yet\n", m, req);
                         list_del(&rreq->req_list);
-                        req->flush = Flushed;
-                        spin_unlock(&m->lock);
-                        p9_conn_rpc_cb(req);
+                        req->status = REQ_STATUS_FLSHD;
+                        spin_unlock(&m->client->lock);
+                        p9_conn_rpc_cb(m->client, req);
                         return 0;
                 }
         }
-        spin_unlock(&m->lock);
+        spin_unlock(&m->client->lock);
 
         clear_thread_flag(TIF_SIGPENDING);
         fc = p9_create_tflush(req->tag);
@@ -927,7 +855,7 @@ p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc)
         struct p9_conn *m = p->conn;
         int err, sigpending;
         unsigned long flags;
-        struct p9_req *req;
+        struct p9_req_t *req;
 
         if (rc)
                 *rc = NULL;
@@ -945,10 +873,10 @@ p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc)
                 return err;
         }
 
-        err = wait_event_interruptible(req->wqueue, req->rcall != NULL ||
-                                                                req->err < 0);
-        if (req->err < 0)
-                err = req->err;
+        err = wait_event_interruptible(*req->wq, req->rc != NULL ||
+                                                                req->t_err < 0);
+        if (req->t_err < 0)
+                err = req->t_err;
 
         if (err == -ERESTARTSYS && client->status == Connected
                                                         && m->err == 0) {
@@ -956,9 +884,9 @@ p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc)
                         /* wait until we get response of the flush message */
                         do {
                                 clear_thread_flag(TIF_SIGPENDING);
-                                err = wait_event_interruptible(req->wqueue,
-                                        req->rcall || req->err);
-                        } while (!req->rcall && !req->err &&
+                                err = wait_event_interruptible(*req->wq,
+                                        req->rc || req->t_err);
+                        } while (!req->rc && !req->t_err &&
                                         err == -ERESTARTSYS &&
                                         client->status == Connected && !m->err);
 
@@ -974,11 +902,11 @@ p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc)
         }
 
         if (rc)
-                *rc = req->rcall;
+                *rc = req->rc;
         else
-                kfree(req->rcall);
+                kfree(req->rc);
 
-        p9_mux_free_request(m, req);
+        p9_free_req(client, req);
         if (err > 0)
                 err = -EIO;
 
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 36bce45e4e44..e18de14c30d5 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -247,10 +247,7 @@ p9_virtio_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
         }
 #endif
 
-        if (n != P9_NOTAG && p9_idpool_check(n, c->tagpool))
-                p9_idpool_put(n, c->tagpool);
-
-        req->status = REQ_STATUS_IDLE;
+        p9_free_req(c, req);
 
         return 0;
 }