[PATCH v4 03/10] sunrpc: replace svc_serv->sv_bc_xprt by boolean flag

Vasily Averin
2018-12-24T11:45:09Z

svc_serv-> sv_bc_xprt is netns-unsafe and cannot be used as pointer.
To prevent its misuse in future it is replaced by new boolean flag.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
fs/nfs/callback.c | 8 +++++---
include/linux/sunrpc/bc_xprt.h | 10 ++++------
include/linux/sunrpc/svc.h | 2 +-
net/sunrpc/svcsock.c | 2 --
net/sunrpc/xprtrdma/svc_rdma_transport.c | 1 -
5 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 509dc5adeb8f..6dd04774aedc 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -206,11 +206,13 @@ static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
goto err_bind;
}

- ret = -EPROTONOSUPPORT;
+ ret = 0;
if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
ret = nfs4_callback_up_net(serv, net);
- else if (xprt->ops->bc_up)
- ret = xprt->ops->bc_up(serv, net);
+ else if (xprt->ops->bc_setup)
+ serv->sv_bc_enabled = true;
+ else
+ ret = -EPROTONOSUPPORT;

if (ret < 0) {
printk(KERN_ERR "NFS: callback service start failed\n");
diff --git a/include/linux/sunrpc/bc_xprt.h b/include/linux/sunrpc/bc_xprt.h
index 28721cf73ec3..4e8c773d02be 100644
--- a/include/linux/sunrpc/bc_xprt.h
+++ b/include/linux/sunrpc/bc_xprt.h
@@ -47,11 +47,9 @@ void xprt_free_bc_rqst(struct rpc_rqst *req);
/*
* Determine if a shared backchannel is in use
*/
-static inline int svc_is_backchannel(const struct svc_rqst *rqstp)
+static inline bool svc_is_backchannel(const struct svc_rqst *rqstp)
{
- if (rqstp->rq_server->sv_bc_xprt)
- return 1;
- return 0;
+ return rqstp->rq_server->sv_bc_enabled;
}
#else /* CONFIG_SUNRPC_BACKCHANNEL */
static inline int xprt_setup_backchannel(struct rpc_xprt *xprt,
@@ -60,9 +58,9 @@ static inline int xprt_setup_backchannel(struct rpc_xprt *xprt,
return 0;
}

-static inline int svc_is_backchannel(const struct svc_rqst *rqstp)
+static inline bool svc_is_backchannel(const struct svc_rqst *rqstp)
{
- return 0;
+ return false;
}

static inline void xprt_free_bc_request(struct rpc_rqst *req)
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index fdb6b317d974..e52385340b3b 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -109,7 +109,7 @@ struct svc_serv {
spinlock_t sv_cb_lock; /* protects the svc_cb_list */
wait_queue_head_t sv_cb_waitq; /* sleep here if there are no
* entries in the svc_cb_list */
- struct svc_xprt *sv_bc_xprt; /* callback on fore channel */
+ bool sv_bc_enabled; /* service uses backchannel */
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
};

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 793149ba1bda..8ce181ecb627 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1623,8 +1623,6 @@ static struct svc_xprt *svc_bc_create_socket(struct svc_serv *serv,
svc_xprt_init(net, &svc_tcp_bc_class, xprt, serv);
set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);

- serv->sv_bc_xprt = xprt;
-
return xprt;
}

diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 2f7ec8912f49..d410e6f34f44 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -136,7 +136,6 @@ static struct svc_xprt *svc_rdma_bc_create(struct svc_serv *serv,

svc_xprt_init(net, &svc_rdma_bc_class, xprt, serv);
set_bit(XPT_CONG_CTRL, &xprt->xpt_flags);
- serv->sv_bc_xprt = xprt;

dprintk("svcrdma: %s(%p)\n", __func__, xprt);
return xprt;
--
2.17.1