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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-11 14:14:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-11 14:14:57 -0700
commit582076ab16779208e7eb6ce712a9c0a6cc5bafe4 (patch)
tree6841c02fa19dba9c4a8299592a7f14344f8944f7 /net/9p
parent79d2d21ee06f3634423d1a45fb6ddfcae59061fd (diff)
parent8a5daf1e2c199746767d94b4036638ba11d528b3 (diff)
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
Diffstat (limited to 'net/9p')
-rw-r--r--net/9p/client.c25
-rw-r--r--net/9p/trans_fd.c110
-rw-r--r--net/9p/trans_rdma.c26
-rw-r--r--net/9p/trans_virtio.c3
4 files changed, 92 insertions, 72 deletions
diff --git a/net/9p/client.c b/net/9p/client.c
index 9186550d77a6..0004cbaac4a4 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -415,9 +415,17 @@ static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
* 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 @@ static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
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 @@ again:
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 b7bd7f2961bf..80d08f6664cb 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -66,20 +66,6 @@ struct p9_fd_opts {
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 @@ struct p9_conn {
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 @@ static void p9_conn_cancel(struct p9_conn *m, int err)
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 @@ static void p9_conn_cancel(struct p9_conn *m, int err)
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 @@ static void p9_read_work(struct work_struct *work)
{
int n, err;
struct p9_conn *m;
+ int status = REQ_STATUS_ERROR;
m = container_of(work, struct p9_conn, rq);
@@ -348,8 +345,7 @@ static void p9_read_work(struct work_struct *work)
"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 @@ static void p9_read_work(struct work_struct *work)
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_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
}
/**
- * 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 @@ static struct p9_conn *p9_conn_create(struct p9_client *client)
p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
set_bit(Wpending, &m->wsched);
}
-
- return m;
}
/**
@@ -669,7 +661,7 @@ static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
{
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 @@ static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
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 parse_opts(char *params, struct p9_fd_opts *opts)
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 @@ static int p9_socket_open(struct p9_client *client, struct socket *csocket)
{
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 @@ static int p9_socket_open(struct p9_client *client, struct socket *csocket)
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 @@ static void p9_conn_destroy(struct p9_conn *m)
p9_conn_cancel(m, -ECONNRESET);
m->client = NULL;
- kfree(m);
}
/**
@@ -881,7 +875,7 @@ static void p9_fd_close(struct p9_client *client)
client->status = Disconnected;
- p9_conn_destroy(ts->conn);
+ p9_conn_destroy(&ts->conn);
if (ts->rd)
fput(ts->rd);
@@ -1033,14 +1027,7 @@ p9_fd_create(struct p9_client *client, const char *addr, char *args)
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 @@ static struct p9_trans_module p9_tcp_trans = {
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
+ .cancelled = p9_fd_cancelled,
.owner = THIS_MODULE,
};
@@ -1064,6 +1052,7 @@ static struct p9_trans_module p9_unix_trans = {
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
+ .cancelled = p9_fd_cancelled,
.owner = THIS_MODULE,
};
@@ -1075,6 +1064,7 @@ static struct p9_trans_module p9_fd_trans = {
.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 8f68df5d2973..14ad43b5cf89 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -193,6 +193,8 @@ static int parse_opts(char *params, struct p9_rdma_opts *opts)
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 @@ handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
}
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 @@ dont_need_post_recv:
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 @@ dont_need_post_recv:
/* 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 @@ static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
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 @@ static struct p9_trans_module p9_rdma_trans = {
.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 ac2666c1d011..6940d8fe8971 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -164,8 +164,7 @@ static void req_done(struct virtqueue *vq)
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);
}
}

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