| Message ID | 1390201154-20815-1-git-send-email-shaobingqing@bwstor.com.cn |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
Hello. On 20-01-2014 10:59, shaobingqing wrote: > In current code, there only one struct rpc_rqst is prealloced. If one > callback request is received from two sk_buff, the xprt_alloc_bc_request > would be execute two times with the same transport->xid. The first time > xprt_alloc_bc_request will alloc one struct rpc_rqst and the TCP_RCV_COPY_DATA > bit of transport->tcp_flags will not be cleared. The second time > xprt_alloc_bc_request could not alloc struct rpc_rqst any more and NULL > pointer will be returned, then xprt_force_disconnect occur. I think one > callback request can be allowed to be received from two sk_buff. > Signed-off-by: shaobingqing <shaobingqing@bwstor.com.cn> > --- > net/sunrpc/xprtsock.c | 11 +++++++++-- > 1 files changed, 9 insertions(+), 2 deletions(-) > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c > index ee03d35..606950d 100644 > --- a/net/sunrpc/xprtsock.c > +++ b/net/sunrpc/xprtsock.c [...] > @@ -1297,7 +1303,8 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, > list_add(&req->rq_bc_list, &bc_serv->sv_cb_list); > spin_unlock(&bc_serv->sv_cb_lock); > wake_up(&bc_serv->sv_cb_waitq); > - } > + } else > + req_partial = req; {} is needed in the *else* branch since it's already used in another branch of *if* -- see Documentation/CodingStyle. WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2014-01-20 at 14:59 +0800, shaobingqing wrote: > In current code, there only one struct rpc_rqst is prealloced. If one > callback request is received from two sk_buff, the xprt_alloc_bc_request > would be execute two times with the same transport->xid. The first time > xprt_alloc_bc_request will alloc one struct rpc_rqst and the TCP_RCV_COPY_DATA > bit of transport->tcp_flags will not be cleared. The second time > xprt_alloc_bc_request could not alloc struct rpc_rqst any more and NULL > pointer will be returned, then xprt_force_disconnect occur. I think one > callback request can be allowed to be received from two sk_buff. > > Signed-off-by: shaobingqing <shaobingqing@bwstor.com.cn> > --- > net/sunrpc/xprtsock.c | 11 +++++++++-- > 1 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c > index ee03d35..606950d 100644 > --- a/net/sunrpc/xprtsock.c > +++ b/net/sunrpc/xprtsock.c > @@ -1271,8 +1271,13 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, > struct sock_xprt *transport = > container_of(xprt, struct sock_xprt, xprt); > struct rpc_rqst *req; > + static struct rpc_rqst *req_partial; > + > + if (req_partial == NULL) > + req = xprt_alloc_bc_request(xprt); > + else if (req_partial->rq_xid == transport->tcp_xid) > + req = req_partial; What happens here if req_partial->rq_xid != transport->tcp_xid? AFAICS, req will be undefined. Either way, you cannot use a static variable for storage here: that isn't re-entrant. > - req = xprt_alloc_bc_request(xprt); > if (req == NULL) { > printk(KERN_WARNING "Callback slot table overflowed\n"); > xprt_force_disconnect(xprt); > @@ -1285,6 +1290,7 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, > > if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) { > struct svc_serv *bc_serv = xprt->bc_serv; > + req_partial = NULL; > > /* > * Add callback request to callback list. The callback > @@ -1297,7 +1303,8 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, > list_add(&req->rq_bc_list, &bc_serv->sv_cb_list); > spin_unlock(&bc_serv->sv_cb_lock); > wake_up(&bc_serv->sv_cb_waitq); > - } > + } else > + req_partial = req; > > req->rq_private_buf.len = transport->tcp_copied; >
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index ee03d35..606950d 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1271,8 +1271,13 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); struct rpc_rqst *req; + static struct rpc_rqst *req_partial; + + if (req_partial == NULL) + req = xprt_alloc_bc_request(xprt); + else if (req_partial->rq_xid == transport->tcp_xid) + req = req_partial; - req = xprt_alloc_bc_request(xprt); if (req == NULL) { printk(KERN_WARNING "Callback slot table overflowed\n"); xprt_force_disconnect(xprt); @@ -1285,6 +1290,7 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) { struct svc_serv *bc_serv = xprt->bc_serv; + req_partial = NULL; /* * Add callback request to callback list. The callback @@ -1297,7 +1303,8 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, list_add(&req->rq_bc_list, &bc_serv->sv_cb_list); spin_unlock(&bc_serv->sv_cb_lock); wake_up(&bc_serv->sv_cb_waitq); - } + } else + req_partial = req; req->rq_private_buf.len = transport->tcp_copied;
In current code, there only one struct rpc_rqst is prealloced. If one callback request is received from two sk_buff, the xprt_alloc_bc_request would be execute two times with the same transport->xid. The first time xprt_alloc_bc_request will alloc one struct rpc_rqst and the TCP_RCV_COPY_DATA bit of transport->tcp_flags will not be cleared. The second time xprt_alloc_bc_request could not alloc struct rpc_rqst any more and NULL pointer will be returned, then xprt_force_disconnect occur. I think one callback request can be allowed to be received from two sk_buff. Signed-off-by: shaobingqing <shaobingqing@bwstor.com.cn> --- net/sunrpc/xprtsock.c | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-)