Merge tag 'for-linus-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
Pull 9p changes from Eric Van Hensbergen:
"A bunch of updates and cleanup within the transport layer,
particularly with a focus on RDMA"
* tag 'for-linus-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
9pnet_rdma: check token type before int conversion
9pnet: trans_fd : allocate struct p9_trans_fd and struct p9_conn together.
9pnet: p9_client->conn field is unused. Remove it.
9P: Get rid of REQ_STATUS_FLSH
9pnet_rdma: add cancelled()
9pnet_rdma: update request status during send
9P: Add cancelled() to the transport functions.
net: Mark function as static in 9p/client.c
9P: Add memory barriers to protect request fields over cb/rpc threads handoff
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index c38a005..6fab66c 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -67,7 +67,6 @@
* @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_ERROR: request encountered an error on the client side
@@ -83,7 +82,6 @@
REQ_STATUS_ALLOC,
REQ_STATUS_UNSENT,
REQ_STATUS_SENT,
- REQ_STATUS_FLSH,
REQ_STATUS_RCVD,
REQ_STATUS_FLSHD,
REQ_STATUS_ERROR,
@@ -130,7 +128,6 @@
* @proto_version: 9P protocol version to use
* @trans_mod: module API instantiated with this client
* @trans: tranport instance state and API
- * @conn: connection state information used by trans_fd
* @fidpool: fid handle accounting for session
* @fidlist: List of active fid handles
* @tagpool - transaction id accounting for session
@@ -159,7 +156,6 @@
struct p9_trans_module *trans_mod;
enum p9_trans_status status;
void *trans;
- struct p9_conn *conn;
struct p9_idpool *fidpool;
struct list_head fidlist;
@@ -261,7 +257,7 @@
int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
-void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *);
diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
index 9a36d92..d9fa68f 100644
--- a/include/net/9p/transport.h
+++ b/include/net/9p/transport.h
@@ -40,6 +40,8 @@
* @close: member function to discard a connection on this transport
* @request: member function to issue a request to the transport
* @cancel: member function to cancel a request (if it hasn't been sent)
+ * @cancelled: member function to notify that a cancelled request will not
+ * not receive a reply
*
* This is the basic API for a transport module which is registered by the
* transport module with the 9P core network module and used by the client
@@ -58,6 +60,7 @@
void (*close) (struct p9_client *);
int (*request) (struct p9_client *, struct p9_req_t *req);
int (*cancel) (struct p9_client *, struct p9_req_t *req);
+ int (*cancelled)(struct p9_client *, struct p9_req_t *req);
int (*zc_request)(struct p9_client *, struct p9_req_t *,
char *, char *, int , int, int, int);
};
diff --git a/net/9p/client.c b/net/9p/client.c
index 9186550..0004cba 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -415,9 +415,17 @@
* req: request received
*
*/
-void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
{
p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
+
+ /*
+ * This barrier is needed to make sure any change made to req before
+ * the other thread wakes up will indeed be seen by the waiting side.
+ */
+ smp_wmb();
+ req->status = status;
+
wake_up(req->wq);
p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
}
@@ -655,16 +663,13 @@
if (IS_ERR(req))
return PTR_ERR(req);
-
/*
* if we haven't received a response for oldreq,
* remove it from the list
*/
- if (oldreq->status == REQ_STATUS_FLSH) {
- spin_lock(&c->lock);
- list_del(&oldreq->req_list);
- spin_unlock(&c->lock);
- }
+ if (oldreq->status == REQ_STATUS_SENT)
+ if (c->trans_mod->cancelled)
+ c->trans_mod->cancelled(c, oldreq);
p9_free_req(c, req);
return 0;
@@ -751,6 +756,12 @@
err = wait_event_interruptible(*req->wq,
req->status >= REQ_STATUS_RCVD);
+ /*
+ * Make sure our req is coherent with regard to updates in other
+ * threads - echoes to wmb() in the callback
+ */
+ smp_rmb();
+
if ((err == -ERESTARTSYS) && (c->status == Connected)
&& (type == P9_TFLUSH)) {
sigpending = 1;
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index b7bd7f2..80d08f6 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -66,20 +66,6 @@
int privport;
};
-/**
- * struct p9_trans_fd - transport state
- * @rd: reference to file to read from
- * @wr: reference of file to write to
- * @conn: connection state reference
- *
- */
-
-struct p9_trans_fd {
- struct file *rd;
- struct file *wr;
- struct p9_conn *conn;
-};
-
/*
* Option Parsing (code inspired by NFS code)
* - a little lazy - parse all fd-transport options
@@ -159,6 +145,20 @@
unsigned long wsched;
};
+/**
+ * struct p9_trans_fd - transport state
+ * @rd: reference to file to read from
+ * @wr: reference of file to write to
+ * @conn: connection state reference
+ *
+ */
+
+struct p9_trans_fd {
+ struct file *rd;
+ struct file *wr;
+ struct p9_conn conn;
+};
+
static void p9_poll_workfn(struct work_struct *work);
static DEFINE_SPINLOCK(p9_poll_lock);
@@ -212,15 +212,9 @@
m->err = err;
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_irqrestore(&m->client->lock, flags);
@@ -228,7 +222,9 @@
list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
list_del(&req->req_list);
- p9_client_cb(m->client, req);
+ if (!req->t_err)
+ req->t_err = err;
+ p9_client_cb(m->client, req, REQ_STATUS_ERROR);
}
}
@@ -302,6 +298,7 @@
{
int n, err;
struct p9_conn *m;
+ int status = REQ_STATUS_ERROR;
m = container_of(work, struct p9_conn, rq);
@@ -348,8 +345,7 @@
"mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
m->req = p9_tag_lookup(m->client, tag);
- if (!m->req || (m->req->status != REQ_STATUS_SENT &&
- m->req->status != REQ_STATUS_FLSH)) {
+ if (!m->req || (m->req->status != REQ_STATUS_SENT)) {
p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
tag);
err = -EIO;
@@ -375,10 +371,10 @@
p9_debug(P9_DEBUG_TRANS, "got new packet\n");
spin_lock(&m->client->lock);
if (m->req->status != REQ_STATUS_ERROR)
- m->req->status = REQ_STATUS_RCVD;
+ status = REQ_STATUS_RCVD;
list_del(&m->req->req_list);
spin_unlock(&m->client->lock);
- p9_client_cb(m->client, m->req);
+ p9_client_cb(m->client, m->req, status);
m->rbuf = NULL;
m->rpos = 0;
m->rsize = 0;
@@ -573,21 +569,19 @@
}
/**
- * p9_conn_create - allocate and initialize the per-session mux data
+ * p9_conn_create - initialize the per-session mux data
* @client: client instance
*
* Note: Creates the polling task if this is the first session.
*/
-static struct p9_conn *p9_conn_create(struct p9_client *client)
+static void p9_conn_create(struct p9_client *client)
{
int n;
- struct p9_conn *m;
+ struct p9_trans_fd *ts = client->trans;
+ struct p9_conn *m = &ts->conn;
p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
- m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
- if (!m)
- return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&m->mux_list);
m->client = client;
@@ -609,8 +603,6 @@
p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
set_bit(Wpending, &m->wsched);
}
-
- return m;
}
/**
@@ -669,7 +661,7 @@
{
int n;
struct p9_trans_fd *ts = client->trans;
- struct p9_conn *m = ts->conn;
+ struct p9_conn *m = &ts->conn;
p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
m, current, req->tc, req->tc->id);
@@ -704,14 +696,26 @@
list_del(&req->req_list);
req->status = REQ_STATUS_FLSHD;
ret = 0;
- } else if (req->status == REQ_STATUS_SENT)
- req->status = REQ_STATUS_FLSH;
-
+ }
spin_unlock(&client->lock);
return ret;
}
+static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
+{
+ p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
+
+ /* we haven't received a response for oldreq,
+ * remove it from the list.
+ */
+ spin_lock(&client->lock);
+ list_del(&req->req_list);
+ spin_unlock(&client->lock);
+
+ return 0;
+}
+
/**
* parse_opts - parse mount options into p9_fd_opts structure
* @params: options string passed from mount
@@ -780,7 +784,7 @@
static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
{
- struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
+ struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
GFP_KERNEL);
if (!ts)
return -ENOMEM;
@@ -806,9 +810,8 @@
{
struct p9_trans_fd *p;
struct file *file;
- int ret;
- p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
+ p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
if (!p)
return -ENOMEM;
@@ -829,20 +832,12 @@
p->rd->f_flags |= O_NONBLOCK;
- p->conn = p9_conn_create(client);
- if (IS_ERR(p->conn)) {
- ret = PTR_ERR(p->conn);
- p->conn = NULL;
- kfree(p);
- sockfd_put(csocket);
- sockfd_put(csocket);
- return ret;
- }
+ p9_conn_create(client);
return 0;
}
/**
- * p9_mux_destroy - cancels all pending requests and frees mux resources
+ * p9_mux_destroy - cancels all pending requests of mux
* @m: mux to destroy
*
*/
@@ -859,7 +854,6 @@
p9_conn_cancel(m, -ECONNRESET);
m->client = NULL;
- kfree(m);
}
/**
@@ -881,7 +875,7 @@
client->status = Disconnected;
- p9_conn_destroy(ts->conn);
+ p9_conn_destroy(&ts->conn);
if (ts->rd)
fput(ts->rd);
@@ -1033,14 +1027,7 @@
return err;
p = (struct p9_trans_fd *) client->trans;
- p->conn = p9_conn_create(client);
- if (IS_ERR(p->conn)) {
- err = PTR_ERR(p->conn);
- p->conn = NULL;
- fput(p->rd);
- fput(p->wr);
- return err;
- }
+ p9_conn_create(client);
return 0;
}
@@ -1053,6 +1040,7 @@
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
+ .cancelled = p9_fd_cancelled,
.owner = THIS_MODULE,
};
@@ -1064,6 +1052,7 @@
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
+ .cancelled = p9_fd_cancelled,
.owner = THIS_MODULE,
};
@@ -1075,6 +1064,7 @@
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
+ .cancelled = p9_fd_cancelled,
.owner = THIS_MODULE,
};
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index 8f68df5..14ad43b 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -193,6 +193,8 @@
if (!*p)
continue;
token = match_token(p, tokens, args);
+ if (token == Opt_err)
+ continue;
r = match_int(&args[0], &option);
if (r < 0) {
p9_debug(P9_DEBUG_ERROR,
@@ -305,8 +307,7 @@
}
req->rc = c->rc;
- req->status = REQ_STATUS_RCVD;
- p9_client_cb(client, req);
+ p9_client_cb(client, req, REQ_STATUS_RCVD);
return;
@@ -511,6 +512,11 @@
goto send_error;
}
+ /* Mark request as `sent' *before* we actually send it,
+ * because doing if after could erase the REQ_STATUS_RCVD
+ * status in case of a very fast reply.
+ */
+ req->status = REQ_STATUS_SENT;
err = ib_post_send(rdma->qp, &wr, &bad_wr);
if (err)
goto send_error;
@@ -520,6 +526,7 @@
/* Handle errors that happened during or while preparing the send: */
send_error:
+ req->status = REQ_STATUS_ERROR;
kfree(c);
p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
@@ -582,12 +589,24 @@
return rdma;
}
-/* its not clear to me we can do anything after send has been posted */
static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
{
+ /* Nothing to do here.
+ * We will take care of it (if we have to) in rdma_cancelled()
+ */
return 1;
}
+/* A request has been fully flushed without a reply.
+ * That means we have posted one buffer in excess.
+ */
+static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
+{
+ struct p9_trans_rdma *rdma = client->trans;
+ atomic_inc(&rdma->excess_rc);
+ return 0;
+}
+
/**
* trans_create_rdma - Transport method for creating atransport instance
* @client: client instance
@@ -721,6 +740,7 @@
.close = rdma_close,
.request = rdma_request,
.cancel = rdma_cancel,
+ .cancelled = rdma_cancelled,
};
/**
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index ac2666c..6940d8f 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -164,8 +164,7 @@
p9_debug(P9_DEBUG_TRANS, ": rc %p\n", rc);
p9_debug(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);
req = p9_tag_lookup(chan->client, rc->tag);
- req->status = REQ_STATUS_RCVD;
- p9_client_cb(chan->client, req);
+ p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
}
}