rpc: share one xps between all backchannels

The spec allows backchannels for multiple clients to share the same tcp
connection.  When that happens, we need to use the same xprt for all of
them.  Similarly, we need the same xps.

This fixes list corruption introduced by the multipath code.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Trond Myklebust <trondmy@primarydata.com>
This commit is contained in:
J. Bruce Fields 2016-05-17 12:38:21 -04:00
Родитель d50039ea5e
Коммит 39a9beab5a
5 изменённых файлов: 19 добавлений и 4 удалений

Просмотреть файл

@ -84,6 +84,7 @@ struct svc_xprt {
struct net *xpt_net;
struct rpc_xprt *xpt_bc_xprt; /* NFSv4.1 backchannel */
struct rpc_xprt_switch *xpt_bc_xps; /* NFSv4.1 backchannel */
};
static inline void unregister_xpt_user(struct svc_xprt *xpt, struct svc_xpt_user *u)

Просмотреть файл

@ -297,6 +297,7 @@ struct xprt_create {
size_t addrlen;
const char *servername;
struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
struct rpc_xprt_switch *bc_xps;
unsigned int flags;
};

Просмотреть файл

@ -452,10 +452,20 @@ static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
struct rpc_clnt *clnt = NULL;
struct rpc_xprt_switch *xps;
xps = xprt_switch_alloc(xprt, GFP_KERNEL);
if (xps == NULL) {
xprt_put(xprt);
return ERR_PTR(-ENOMEM);
if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
WARN_ON(args->protocol != XPRT_TRANSPORT_BC_TCP);
xps = args->bc_xprt->xpt_bc_xps;
xprt_switch_get(xps);
} else {
xps = xprt_switch_alloc(xprt, GFP_KERNEL);
if (xps == NULL) {
xprt_put(xprt);
return ERR_PTR(-ENOMEM);
}
if (xprt->bc_xprt) {
xprt_switch_get(xps);
xprt->bc_xprt->xpt_bc_xps = xps;
}
}
clnt = rpc_new_client(args, xps, xprt, NULL);
if (IS_ERR(clnt))

Просмотреть файл

@ -136,6 +136,8 @@ static void svc_xprt_free(struct kref *kref)
/* See comment on corresponding get in xs_setup_bc_tcp(): */
if (xprt->xpt_bc_xprt)
xprt_put(xprt->xpt_bc_xprt);
if (xprt->xpt_bc_xps)
xprt_switch_put(xprt->xpt_bc_xps);
xprt->xpt_ops->xpo_free(xprt);
module_put(owner);
}

Просмотреть файл

@ -3057,6 +3057,7 @@ static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
return xprt;
args->bc_xprt->xpt_bc_xprt = NULL;
args->bc_xprt->xpt_bc_xps = NULL;
xprt_put(xprt);
ret = ERR_PTR(-EINVAL);
out_err: