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-rw-r--r--fs/nfs/nfs4proc.c61
-rw-r--r--fs/nfs/pnfs_nfs.c16
-rw-r--r--include/linux/sunrpc/clnt.h18
-rw-r--r--include/linux/sunrpc/sched.h32
-rw-r--r--include/linux/sunrpc/xprt.h22
-rw-r--r--include/linux/sunrpc/xprtmultipath.h69
-rw-r--r--net/sunrpc/Makefile3
-rw-r--r--net/sunrpc/auth_gss/auth_gss.c4
-rw-r--r--net/sunrpc/clnt.c328
-rw-r--r--net/sunrpc/rpcb_clnt.c10
-rw-r--r--net/sunrpc/sched.c2
-rw-r--r--net/sunrpc/xprt.c42
-rw-r--r--net/sunrpc/xprtmultipath.c475
-rw-r--r--net/sunrpc/xprtsock.c4
14 files changed, 952 insertions, 134 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1e103b4f4ad7..c70de30b80f1 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6782,13 +6782,26 @@ nfs41_same_server_scope(struct nfs41_server_scope *a,
return false;
}
+static void
+nfs4_bind_one_conn_to_session_done(struct rpc_task *task, void *calldata)
+{
+}
+
+static const struct rpc_call_ops nfs4_bind_one_conn_to_session_ops = {
+ .rpc_call_done = &nfs4_bind_one_conn_to_session_done,
+};
+
/*
- * nfs4_proc_bind_conn_to_session()
+ * nfs4_proc_bind_one_conn_to_session()
*
* The 4.1 client currently uses the same TCP connection for the
* fore and backchannel.
*/
-int nfs4_proc_bind_conn_to_session(struct nfs_client *clp, struct rpc_cred *cred)
+static
+int nfs4_proc_bind_one_conn_to_session(struct rpc_clnt *clnt,
+ struct rpc_xprt *xprt,
+ struct nfs_client *clp,
+ struct rpc_cred *cred)
{
int status;
struct nfs41_bind_conn_to_session_args args = {
@@ -6803,6 +6816,14 @@ int nfs4_proc_bind_conn_to_session(struct nfs_client *clp, struct rpc_cred *cred
.rpc_resp = &res,
.rpc_cred = cred,
};
+ struct rpc_task_setup task_setup_data = {
+ .rpc_client = clnt,
+ .rpc_xprt = xprt,
+ .callback_ops = &nfs4_bind_one_conn_to_session_ops,
+ .rpc_message = &msg,
+ .flags = RPC_TASK_TIMEOUT,
+ };
+ struct rpc_task *task;
dprintk("--> %s\n", __func__);
@@ -6810,7 +6831,16 @@ int nfs4_proc_bind_conn_to_session(struct nfs_client *clp, struct rpc_cred *cred
if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
args.dir = NFS4_CDFC4_FORE;
- status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
+ /* Do not set the backchannel flag unless this is clnt->cl_xprt */
+ if (xprt != rcu_access_pointer(clnt->cl_xprt))
+ args.dir = NFS4_CDFC4_FORE;
+
+ task = rpc_run_task(&task_setup_data);
+ if (!IS_ERR(task)) {
+ status = task->tk_status;
+ rpc_put_task(task);
+ } else
+ status = PTR_ERR(task);
trace_nfs4_bind_conn_to_session(clp, status);
if (status == 0) {
if (memcmp(res.sessionid.data,
@@ -6837,6 +6867,31 @@ out:
return status;
}
+struct rpc_bind_conn_calldata {
+ struct nfs_client *clp;
+ struct rpc_cred *cred;
+};
+
+static int
+nfs4_proc_bind_conn_to_session_callback(struct rpc_clnt *clnt,
+ struct rpc_xprt *xprt,
+ void *calldata)
+{
+ struct rpc_bind_conn_calldata *p = calldata;
+
+ return nfs4_proc_bind_one_conn_to_session(clnt, xprt, p->clp, p->cred);
+}
+
+int nfs4_proc_bind_conn_to_session(struct nfs_client *clp, struct rpc_cred *cred)
+{
+ struct rpc_bind_conn_calldata data = {
+ .clp = clp,
+ .cred = cred,
+ };
+ return rpc_clnt_iterate_for_each_xprt(clp->cl_rpcclient,
+ nfs4_proc_bind_conn_to_session_callback, &data);
+}
+
/*
* Minimum set of SP4_MACH_CRED operations from RFC 5661 in the enforce map
* and operations we'd like to see to enable certain features in the allow map
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index 81ac6480f9e7..4aaed890048f 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -606,12 +606,22 @@ static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
dprintk("%s: DS %s: trying address %s\n",
__func__, ds->ds_remotestr, da->da_remotestr);
- clp = get_v3_ds_connect(mds_srv->nfs_client,
+ if (!IS_ERR(clp)) {
+ struct xprt_create xprt_args = {
+ .ident = XPRT_TRANSPORT_TCP,
+ .net = clp->cl_net,
+ .dstaddr = (struct sockaddr *)&da->da_addr,
+ .addrlen = da->da_addrlen,
+ .servername = clp->cl_hostname,
+ };
+ /* Add this address as an alias */
+ rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
+ rpc_clnt_test_and_add_xprt, NULL);
+ } else
+ clp = get_v3_ds_connect(mds_srv->nfs_client,
(struct sockaddr *)&da->da_addr,
da->da_addrlen, IPPROTO_TCP,
timeo, retrans, au_flavor);
- if (!IS_ERR(clp))
- break;
}
if (IS_ERR(clp)) {
diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 131032f15cc1..9a7ddbaf116e 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -25,6 +25,7 @@
#include <asm/signal.h>
#include <linux/path.h>
#include <net/ipv6.h>
+#include <linux/sunrpc/xprtmultipath.h>
struct rpc_inode;
@@ -67,6 +68,7 @@ struct rpc_clnt {
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
struct dentry *cl_debugfs; /* debugfs directory */
#endif
+ struct rpc_xprt_iter cl_xpi;
};
/*
@@ -139,7 +141,6 @@ struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
struct rpc_xprt *xprt);
struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *,
const struct rpc_program *, u32);
-void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt);
struct rpc_clnt *rpc_clone_client(struct rpc_clnt *);
struct rpc_clnt *rpc_clone_client_set_auth(struct rpc_clnt *,
rpc_authflavor_t);
@@ -181,6 +182,21 @@ size_t rpc_peeraddr(struct rpc_clnt *, struct sockaddr *, size_t);
const char *rpc_peeraddr2str(struct rpc_clnt *, enum rpc_display_format_t);
int rpc_localaddr(struct rpc_clnt *, struct sockaddr *, size_t);
+int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
+ int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
+ void *data);
+
+int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
+ struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt,
+ void *dummy);
+int rpc_clnt_add_xprt(struct rpc_clnt *, struct xprt_create *,
+ int (*setup)(struct rpc_clnt *,
+ struct rpc_xprt_switch *,
+ struct rpc_xprt *,
+ void *),
+ void *data);
+
const char *rpc_proc_name(const struct rpc_task *task);
#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_CLNT_H */
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index d703f0ef37d8..05a1809c44d9 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -42,40 +42,43 @@ struct rpc_wait {
*/
struct rpc_task {
atomic_t tk_count; /* Reference count */
+ int tk_status; /* result of last operation */
struct list_head tk_task; /* global list of tasks */
- struct rpc_clnt * tk_client; /* RPC client */
- struct rpc_rqst * tk_rqstp; /* RPC request */
-
- /*
- * RPC call state
- */
- struct rpc_message tk_msg; /* RPC call info */
/*
* callback to be executed after waking up
* action next procedure for async tasks
- * tk_ops caller callbacks
*/
void (*tk_callback)(struct rpc_task *);
void (*tk_action)(struct rpc_task *);
- const struct rpc_call_ops *tk_ops;
- void * tk_calldata;
unsigned long tk_timeout; /* timeout for rpc_sleep() */
unsigned long tk_runstate; /* Task run status */
- struct workqueue_struct *tk_workqueue; /* Normally rpciod, but could
- * be any workqueue
- */
+
struct rpc_wait_queue *tk_waitqueue; /* RPC wait queue we're on */
union {
struct work_struct tk_work; /* Async task work queue */
struct rpc_wait tk_wait; /* RPC wait */
} u;
+ /*
+ * RPC call state
+ */
+ struct rpc_message tk_msg; /* RPC call info */
+ void * tk_calldata; /* Caller private data */
+ const struct rpc_call_ops *tk_ops; /* Caller callbacks */
+
+ struct rpc_clnt * tk_client; /* RPC client */
+ struct rpc_xprt * tk_xprt; /* Transport */
+
+ struct rpc_rqst * tk_rqstp; /* RPC request */
+
+ struct workqueue_struct *tk_workqueue; /* Normally rpciod, but could
+ * be any workqueue
+ */
ktime_t tk_start; /* RPC task init timestamp */
pid_t tk_owner; /* Process id for batching tasks */
- int tk_status; /* result of last operation */
unsigned short tk_flags; /* misc flags */
unsigned short tk_timeouts; /* maj timeouts */
@@ -100,6 +103,7 @@ struct rpc_call_ops {
struct rpc_task_setup {
struct rpc_task *task;
struct rpc_clnt *rpc_client;
+ struct rpc_xprt *rpc_xprt;
const struct rpc_message *rpc_message;
const struct rpc_call_ops *callback_ops;
void *callback_data;
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 69ef5b3ab038..fb0d212e0d3a 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -13,6 +13,7 @@
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/ktime.h>
+#include <linux/kref.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/msg_prot.h>
@@ -166,7 +167,7 @@ enum xprt_transports {
};
struct rpc_xprt {
- atomic_t count; /* Reference count */
+ struct kref kref; /* Reference count */
struct rpc_xprt_ops * ops; /* transport methods */
const struct rpc_timeout *timeout; /* timeout parms */
@@ -197,6 +198,11 @@ struct rpc_xprt {
unsigned int bind_index; /* bind function index */
/*
+ * Multipath
+ */
+ struct list_head xprt_switch;
+
+ /*
* Connection of transports
*/
unsigned long bind_timeout,
@@ -256,6 +262,7 @@ struct rpc_xprt {
struct dentry *debugfs; /* debugfs directory */
atomic_t inject_disconnect;
#endif
+ struct rcu_head rcu;
};
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
@@ -318,24 +325,13 @@ int xprt_adjust_timeout(struct rpc_rqst *req);
void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
void xprt_release(struct rpc_task *task);
+struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
void xprt_put(struct rpc_xprt *xprt);
struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
unsigned int num_prealloc,
unsigned int max_req);
void xprt_free(struct rpc_xprt *);
-/**
- * xprt_get - return a reference to an RPC transport.
- * @xprt: pointer to the transport
- *
- */
-static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
-{
- if (atomic_inc_not_zero(&xprt->count))
- return xprt;
- return NULL;
-}
-
static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
{
return p + xprt->tsh_size;
diff --git a/include/linux/sunrpc/xprtmultipath.h b/include/linux/sunrpc/xprtmultipath.h
new file mode 100644
index 000000000000..5a9acffa41be
--- /dev/null
+++ b/include/linux/sunrpc/xprtmultipath.h
@@ -0,0 +1,69 @@
+/*
+ * RPC client multipathing definitions
+ *
+ * Copyright (c) 2015, 2016, Primary Data, Inc. All rights reserved.
+ *
+ * Trond Myklebust <trond.myklebust@primarydata.com>
+ */
+#ifndef _NET_SUNRPC_XPRTMULTIPATH_H
+#define _NET_SUNRPC_XPRTMULTIPATH_H
+
+struct rpc_xprt_iter_ops;
+struct rpc_xprt_switch {
+ spinlock_t xps_lock;
+ struct kref xps_kref;
+
+ unsigned int xps_nxprts;
+ struct list_head xps_xprt_list;
+
+ struct net * xps_net;
+
+ const struct rpc_xprt_iter_ops *xps_iter_ops;
+
+ struct rcu_head xps_rcu;
+};
+
+struct rpc_xprt_iter {
+ struct rpc_xprt_switch __rcu *xpi_xpswitch;
+ struct rpc_xprt * xpi_cursor;
+
+ const struct rpc_xprt_iter_ops *xpi_ops;
+};
+
+
+struct rpc_xprt_iter_ops {
+ void (*xpi_rewind)(struct rpc_xprt_iter *);
+ struct rpc_xprt *(*xpi_xprt)(struct rpc_xprt_iter *);
+ struct rpc_xprt *(*xpi_next)(struct rpc_xprt_iter *);
+};
+
+extern struct rpc_xprt_switch *xprt_switch_alloc(struct rpc_xprt *xprt,
+ gfp_t gfp_flags);
+
+extern struct rpc_xprt_switch *xprt_switch_get(struct rpc_xprt_switch *xps);
+extern void xprt_switch_put(struct rpc_xprt_switch *xps);
+
+extern void rpc_xprt_switch_set_roundrobin(struct rpc_xprt_switch *xps);
+
+extern void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt);
+extern void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt);
+
+extern void xprt_iter_init(struct rpc_xprt_iter *xpi,
+ struct rpc_xprt_switch *xps);
+
+extern void xprt_iter_init_listall(struct rpc_xprt_iter *xpi,
+ struct rpc_xprt_switch *xps);
+
+extern void xprt_iter_destroy(struct rpc_xprt_iter *xpi);
+
+extern struct rpc_xprt_switch *xprt_iter_xchg_switch(
+ struct rpc_xprt_iter *xpi,
+ struct rpc_xprt_switch *newswitch);
+
+extern struct rpc_xprt *xprt_iter_xprt(struct rpc_xprt_iter *xpi);
+extern struct rpc_xprt *xprt_iter_get_xprt(struct rpc_xprt_iter *xpi);
+extern struct rpc_xprt *xprt_iter_get_next(struct rpc_xprt_iter *xpi);
+
+#endif
diff --git a/net/sunrpc/Makefile b/net/sunrpc/Makefile
index b512fbd9d79a..ea7ffa12e0f9 100644
--- a/net/sunrpc/Makefile
+++ b/net/sunrpc/Makefile
@@ -12,7 +12,8 @@ sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \
svc.o svcsock.o svcauth.o svcauth_unix.o \
addr.o rpcb_clnt.o timer.o xdr.o \
sunrpc_syms.o cache.o rpc_pipe.o \
- svc_xprt.o
+ svc_xprt.o \
+ xprtmultipath.o
sunrpc-$(CONFIG_SUNRPC_DEBUG) += debugfs.o
sunrpc-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel_rqst.o
sunrpc-$(CONFIG_PROC_FS) += stats.o
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index cabf586f47d7..8c6bc795f060 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1181,12 +1181,12 @@ static struct rpc_auth *
gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
{
struct gss_auth *gss_auth;
- struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
+ struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
while (clnt != clnt->cl_parent) {
struct rpc_clnt *parent = clnt->cl_parent;
/* Find the original parent for this transport */
- if (rcu_access_pointer(parent->cl_xprt) != xprt)
+ if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
break;
clnt = parent;
}
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index b7f21044f4d8..7e0c9bf22df8 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -354,6 +354,7 @@ static void rpc_free_clid(struct rpc_clnt *clnt)
}
static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
+ struct rpc_xprt_switch *xps,
struct rpc_xprt *xprt,
struct rpc_clnt *parent)
{
@@ -411,6 +412,8 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
}
rpc_clnt_set_transport(clnt, xprt, timeout);
+ xprt_iter_init(&clnt->cl_xpi, xps);
+ xprt_switch_put(xps);
clnt->cl_rtt = &clnt->cl_rtt_default;
rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
@@ -438,6 +441,7 @@ out_no_clid:
out_err:
rpciod_down();
out_no_rpciod:
+ xprt_switch_put(xps);
xprt_put(xprt);
return ERR_PTR(err);
}
@@ -446,8 +450,13 @@ struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
struct rpc_xprt *xprt)
{
struct rpc_clnt *clnt = NULL;
+ struct rpc_xprt_switch *xps;
- clnt = rpc_new_client(args, xprt, NULL);
+ xps = xprt_switch_alloc(xprt, GFP_KERNEL);
+ if (xps == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ clnt = rpc_new_client(args, xps, xprt, NULL);
if (IS_ERR(clnt))
return clnt;
@@ -564,6 +573,7 @@ EXPORT_SYMBOL_GPL(rpc_create);
static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
struct rpc_clnt *clnt)
{
+ struct rpc_xprt_switch *xps;
struct rpc_xprt *xprt;
struct rpc_clnt *new;
int err;
@@ -571,13 +581,17 @@ static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
err = -ENOMEM;
rcu_read_lock();
xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
+ xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
rcu_read_unlock();
- if (xprt == NULL)
+ if (xprt == NULL || xps == NULL) {
+ xprt_put(xprt);
+ xprt_switch_put(xps);
goto out_err;
+ }
args->servername = xprt->servername;
args->nodename = clnt->cl_nodename;
- new = rpc_new_client(args, xprt, clnt);
+ new = rpc_new_client(args, xps, xprt, clnt);
if (IS_ERR(new)) {
err = PTR_ERR(new);
goto out_err;
@@ -657,6 +671,7 @@ int rpc_switch_client_transport(struct rpc_clnt *clnt,
{
const struct rpc_timeout *old_timeo;
rpc_authflavor_t pseudoflavor;
+ struct rpc_xprt_switch *xps, *oldxps;
struct rpc_xprt *xprt, *old;
struct rpc_clnt *parent;
int err;
@@ -668,10 +683,17 @@ int rpc_switch_client_transport(struct rpc_clnt *clnt,
return PTR_ERR(xprt);
}
+ xps = xprt_switch_alloc(xprt, GFP_KERNEL);
+ if (xps == NULL) {
+ xprt_put(xprt);
+ return -ENOMEM;
+ }
+
pseudoflavor = clnt->cl_auth->au_flavor;
old_timeo = clnt->cl_timeout;
old = rpc_clnt_set_transport(clnt, xprt, timeout);
+ oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
rpc_unregister_client(clnt);
__rpc_clnt_remove_pipedir(clnt);
@@ -697,20 +719,74 @@ int rpc_switch_client_transport(struct rpc_clnt *clnt,
synchronize_rcu();
if (parent != clnt)
rpc_release_client(parent);
+ xprt_switch_put(oldxps);
xprt_put(old);
dprintk("RPC: replaced xprt for clnt %p\n", clnt);
return 0;
out_revert:
+ xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
rpc_clnt_set_transport(clnt, old, old_timeo);
clnt->cl_parent = parent;
rpc_client_register(clnt, pseudoflavor, NULL);
+ xprt_switch_put(xps);
xprt_put(xprt);
dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
return err;
}
EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
+static
+int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
+{
+ struct rpc_xprt_switch *xps;
+
+ rcu_read_lock();
+ xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
+ rcu_read_unlock();
+ if (xps == NULL)
+ return -EAGAIN;
+ xprt_iter_init_listall(xpi, xps);
+ xprt_switch_put(xps);
+ return 0;
+}
+
+/**
+ * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
+ * @clnt: pointer to client
+ * @fn: function to apply
+ * @data: void pointer to function data
+ *
+ * Iterates through the list of RPC transports currently attached to the
+ * client and applies the function fn(clnt, xprt, data).
+ *
+ * On error, the iteration stops, and the function returns the error value.
+ */
+int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
+ int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
+ void *data)
+{
+ struct rpc_xprt_iter xpi;
+ int ret;
+
+ ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
+ if (ret)
+ return ret;
+ for (;;) {
+ struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
+
+ if (!xprt)
+ break;
+ ret = fn(clnt, xprt, data);
+ xprt_put(xprt);
+ if (ret < 0)
+ break;
+ }
+ xprt_iter_destroy(&xpi);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
+
/*
* Kill all tasks for the given client.
* XXX: kill their descendants as well?
@@ -783,6 +859,7 @@ rpc_free_client(struct rpc_clnt *clnt)
rpc_free_iostats(clnt->cl_metrics);
clnt->cl_metrics = NULL;
xprt_put(rcu_dereference_raw(clnt->cl_xprt));
+ xprt_iter_destroy(&clnt->cl_xpi);
rpciod_down();
rpc_free_clid(clnt);
kfree(clnt);
@@ -868,6 +945,7 @@ EXPORT_SYMBOL_GPL(rpc_bind_new_program);
void rpc_task_release_client(struct rpc_task *task)
{
struct rpc_clnt *clnt = task->tk_client;
+ struct rpc_xprt *xprt = task->tk_xprt;
if (clnt != NULL) {
/* Remove from client task list */
@@ -878,13 +956,22 @@ void rpc_task_release_client(struct rpc_task *task)
rpc_release_client(clnt);
}
+
+ if (xprt != NULL) {
+ task->tk_xprt = NULL;
+
+ xprt_put(xprt);
+ }
}
static
void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
{
+
if (clnt != NULL) {
rpc_task_release_client(task);
+ if (task->tk_xprt == NULL)
+ task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
task->tk_client = clnt;
atomic_inc(&clnt->cl_count);
if (clnt->cl_softrtry)
@@ -900,14 +987,6 @@ void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
}
}
-void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
-{
- rpc_task_release_client(task);
- rpc_task_set_client(task, clnt);
-}
-EXPORT_SYMBOL_GPL(rpc_task_reset_client);
-
-
static void
rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
{
@@ -2104,11 +2183,9 @@ call_timeout(struct rpc_task *task)
}
if (RPC_IS_SOFT(task)) {
if (clnt->cl_chatty) {
- rcu_read_lock();
printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
clnt->cl_program->name,
- rcu_dereference(clnt->cl_xprt)->servername);
- rcu_read_unlock();
+ task->tk_xprt->servername);
}
if (task->tk_flags & RPC_TASK_TIMEOUT)
rpc_exit(task, -ETIMEDOUT);
@@ -2120,11 +2197,9 @@ call_timeout(struct rpc_task *task)
if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
task->tk_flags |= RPC_CALL_MAJORSEEN;
if (clnt->cl_chatty) {
- rcu_read_lock();
printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
clnt->cl_program->name,
- rcu_dereference(clnt->cl_xprt)->servername);
- rcu_read_unlock();
+ task->tk_xprt->servername);
}
}
rpc_force_rebind(clnt);
@@ -2154,11 +2229,9 @@ call_decode(struct rpc_task *task)
if (task->tk_flags & RPC_CALL_MAJORSEEN) {
if (clnt->cl_chatty) {
- rcu_read_lock();
printk(KERN_NOTICE "%s: server %s OK\n",
clnt->cl_program->name,
- rcu_dereference(clnt->cl_xprt)->servername);
- rcu_read_unlock();
+ task->tk_xprt->servername);
}
task->tk_flags &= ~RPC_CALL_MAJORSEEN;
}
@@ -2312,11 +2385,9 @@ rpc_verify_header(struct rpc_task *task)
task->tk_action = call_bind;
goto out_retry;
case RPC_AUTH_TOOWEAK:
- rcu_read_lock();
printk(KERN_NOTICE "RPC: server %s requires stronger "
"authentication.\n",
- rcu_dereference(clnt->cl_xprt)->servername);
- rcu_read_unlock();
+ task->tk_xprt->servername);
break;
default:
dprintk("RPC: %5u %s: unknown auth error: %x\n",
@@ -2341,27 +2412,27 @@ rpc_verify_header(struct rpc_task *task)
case RPC_SUCCESS:
return p;
case RPC_PROG_UNAVAIL:
- dprintk_rcu("RPC: %5u %s: program %u is unsupported "
+ dprintk("RPC: %5u %s: program %u is unsupported "
"by server %s\n", task->tk_pid, __func__,
(unsigned int)clnt->cl_prog,
- rcu_dereference(clnt->cl_xprt)->servername);
+ task->tk_xprt->servername);
error = -EPFNOSUPPORT;
goto out_err;
case RPC_PROG_MISMATCH:
- dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
+ dprintk("RPC: %5u %s: program %u, version %u unsupported "
"by server %s\n", task->tk_pid, __func__,
(unsigned int)clnt->cl_prog,
(unsigned int)clnt->cl_vers,
- rcu_dereference(clnt->cl_xprt)->servername);
+ task->tk_xprt->servername);
error = -EPROTONOSUPPORT;
goto out_err;
case RPC_PROC_UNAVAIL:
- dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
+ dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
"version %u on server %s\n",
task->tk_pid, __func__,
rpc_proc_name(task),
clnt->cl_prog, clnt->cl_vers,
- rcu_dereference(clnt->cl_xprt)->servername);
+ task->tk_xprt->servername);
error = -EOPNOTSUPP;
goto out_err;
case RPC_GARBAGE_ARGS:
@@ -2421,7 +2492,10 @@ static int rpc_ping(struct rpc_clnt *clnt)
return err;
}
-struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
+static
+struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
+ struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
+ const struct rpc_call_ops *ops, void *data)
{
struct rpc_message msg = {
.rpc_proc = &rpcproc_null,
@@ -2429,14 +2503,140 @@ struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int
};
struct rpc_task_setup task_setup_data = {
.rpc_client = clnt,
+ .rpc_xprt = xprt,
.rpc_message = &msg,
- .callback_ops = &rpc_default_ops,
+ .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
+ .callback_data = data,
.flags = flags,
};
+
return rpc_run_task(&task_setup_data);
}
+
+struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
+{
+ return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
+}
EXPORT_SYMBOL_GPL(rpc_call_null);
+struct rpc_cb_add_xprt_calldata {
+ struct rpc_xprt_switch *xps;
+ struct rpc_xprt *xprt;
+};
+
+static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
+{
+ struct rpc_cb_add_xprt_calldata *data = calldata;
+
+ if (task->tk_status == 0)
+ rpc_xprt_switch_add_xprt(data->xps, data->xprt);
+}
+
+static void rpc_cb_add_xprt_release(void *calldata)
+{
+ struct rpc_cb_add_xprt_calldata *data = calldata;
+
+ xprt_put(data->xprt);
+ xprt_switch_put(data->xps);
+ kfree(data);
+}
+
+const static struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
+ .rpc_call_done = rpc_cb_add_xprt_done,
+ .rpc_release = rpc_cb_add_xprt_release,
+};
+
+/**
+ * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
+ * @clnt: pointer to struct rpc_clnt
+ * @xps: pointer to struct rpc_xprt_switch,
+ * @xprt: pointer struct rpc_xprt
+ * @dummy: unused
+ */
+int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
+ struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
+ void *dummy)
+{
+ struct rpc_cb_add_xprt_calldata *data;
+ struct rpc_cred *cred;
+ struct rpc_task *task;
+
+ data = kmalloc(sizeof(*data), GFP_NOFS);
+ if (!data)
+ return -ENOMEM;
+ data->xps = xprt_switch_get(xps);
+ data->xprt = xprt_get(xprt);
+
+ cred = authnull_ops.lookup_cred(NULL, NULL, 0);
+ task = rpc_call_null_helper(clnt, xprt, cred,
+ RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
+ &rpc_cb_add_xprt_call_ops, data);
+ put_rpccred(cred);
+ if (IS_ERR(task))
+ return PTR_ERR(task);
+ rpc_put_task(task);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
+
+/**
+ * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
+ * @clnt: pointer to struct rpc_clnt
+ * @xprtargs: pointer to struct xprt_create
+ * @setup: callback to test and/or set up the connection
+ * @data: pointer to setup function data
+ *
+ * Creates a new transport using the parameters set in args and
+ * adds it to clnt.
+ * If ping is set, then test that connectivity succeeds before
+ * adding the new transport.
+ *
+ */
+int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
+ struct xprt_create *xprtargs,
+ int (*setup)(struct rpc_clnt *,
+ struct rpc_xprt_switch *,
+ struct rpc_xprt *,
+ void *),
+ void *data)
+{
+ struct rpc_xprt_switch *xps;
+ struct rpc_xprt *xprt;
+ unsigned char resvport;
+ int ret = 0;
+
+ rcu_read_lock();
+ xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
+ xprt = xprt_iter_xprt(&clnt->cl_xpi);
+ if (xps == NULL || xprt == NULL) {
+ rcu_read_unlock();
+ return -EAGAIN;
+ }
+ resvport = xprt->resvport;
+ rcu_read_unlock();
+
+ xprt = xprt_create_transport(xprtargs);
+ if (IS_ERR(xprt)) {
+ ret = PTR_ERR(xprt);
+ goto out_put_switch;
+ }
+ xprt->resvport = resvport;
+
+ rpc_xprt_switch_set_roundrobin(xps);
+ if (setup) {
+ ret = setup(clnt, xps, xprt, data);
+ if (ret != 0)
+ goto out_put_xprt;
+ }
+ rpc_xprt_switch_add_xprt(xps, xprt);
+out_put_xprt:
+ xprt_put(xprt);
+out_put_switch:
+ xprt_switch_put(xps);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
+
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
static void rpc_show_header(void)
{
@@ -2483,57 +2683,39 @@ void rpc_show_tasks(struct net *net)
#endif
#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
+static int
+rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
+ struct rpc_xprt *xprt,
+ void *dummy)
+{
+ return xprt_enable_swap(xprt);
+}
+
int
rpc_clnt_swap_activate(struct rpc_clnt *clnt)
{
- int ret = 0;
- struct rpc_xprt *xprt;
-
- if (atomic_inc_return(&clnt->cl_swapper) == 1) {
-retry:
- rcu_read_lock();
- xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
- rcu_read_unlock();
- if (!xprt) {
- /*
- * If we didn't get a reference, then we likely are
- * racing with a migration event. Wait for a grace
- * period and try again.
- */
- synchronize_rcu();
- goto retry;
- }
-
- ret = xprt_enable_swap(xprt);
- xprt_put(xprt);
- }
- return ret;
+ if (atomic_inc_return(&clnt->cl_swapper) == 1)
+ return rpc_clnt_iterate_for_each_xprt(clnt,
+ rpc_clnt_swap_activate_callback, NULL);
+ return 0;
}
EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
+static int
+rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
+ struct rpc_xprt *xprt,
+ void *dummy)
+{
+ xprt_disable_swap(xprt);
+ return 0;
+}
+
void
rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
{
- struct rpc_xprt *xprt;
-
- if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) {
-retry:
- rcu_read_lock();
- xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
- rcu_read_unlock();
- if (!xprt) {
- /*
- * If we didn't get a reference, then we likely are
- * racing with a migration event. Wait for a grace
- * period and try again.
- */
- synchronize_rcu();
- goto retry;
- }
-
- xprt_disable_swap(xprt);
- xprt_put(xprt);
- }
+ if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
+ rpc_clnt_iterate_for_each_xprt(clnt,
+ rpc_clnt_swap_deactivate_callback, NULL);
}
EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
#endif /* CONFIG_SUNRPC_SWAP */
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index cf5770d8f49a..5b30603596d0 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -648,10 +648,10 @@ static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbi
static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
{
struct rpc_clnt *parent = clnt->cl_parent;
- struct rpc_xprt *xprt = rcu_dereference(clnt->cl_xprt);
+ struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
while (parent != clnt) {
- if (rcu_dereference(parent->cl_xprt) != xprt)
+ if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
break;
if (clnt->cl_autobind)
break;
@@ -683,11 +683,9 @@ void rpcb_getport_async(struct rpc_task *task)
int status;
rcu_read_lock();
- do {
- clnt = rpcb_find_transport_owner(task->tk_client);
- xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
- } while (xprt == NULL);
+ clnt = rpcb_find_transport_owner(task->tk_client);
rcu_read_unlock();
+ xprt = xprt_get(task->tk_xprt);
dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
task->tk_pid, __func__,
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 73ad57a59989..fcfd48d263f6 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -909,6 +909,8 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta
/* Initialize workqueue for async tasks */
task->tk_workqueue = task_setup_data->workqueue;
+ task->tk_xprt = xprt_get(task_setup_data->rpc_xprt);
+
if (task->tk_ops->rpc_call_prepare != NULL)
task->tk_action = rpc_prepare_task;
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 37edea6fa92d..216a1385718a 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -48,6 +48,7 @@
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/metrics.h>
#include <linux/sunrpc/bc_xprt.h>
+#include <linux/rcupdate.h>
#include <trace/events/sunrpc.h>
@@ -1166,7 +1167,7 @@ void xprt_free(struct rpc_xprt *xprt)
{
put_net(xprt->xprt_net);
xprt_free_all_slots(xprt);
- kfree(xprt);
+ kfree_rcu(xprt, rcu);
}
EXPORT_SYMBOL_GPL(xprt_free);
@@ -1180,7 +1181,7 @@ EXPORT_SYMBOL_GPL(xprt_free);
*/
void xprt_reserve(struct rpc_task *task)
{
- struct rpc_xprt *xprt;
+ struct rpc_xprt *xprt = task->tk_xprt;
task->tk_status = 0;
if (task->tk_rqstp != NULL)
@@ -1188,11 +1189,8 @@ void xprt_reserve(struct rpc_task *task)
task->tk_timeout = 0;
task->tk_status = -EAGAIN;
- rcu_read_lock();
- xprt = rcu_dereference(task->tk_client->cl_xprt);
if (!xprt_throttle_congested(xprt, task))
xprt->ops->alloc_slot(xprt, task);
- rcu_read_unlock();
}
/**
@@ -1206,7 +1204,7 @@ void xprt_reserve(struct rpc_task *task)
*/
void xprt_retry_reserve(struct rpc_task *task)
{
- struct rpc_xprt *xprt;
+ struct rpc_xprt *xprt = task->tk_xprt;
task->tk_status = 0;
if (task->tk_rqstp != NULL)
@@ -1214,10 +1212,7 @@ void xprt_retry_reserve(struct rpc_task *task)
task->tk_timeout = 0;
task->tk_status = -EAGAIN;
- rcu_read_lock();
- xprt = rcu_dereference(task->tk_client->cl_xprt);
xprt->ops->alloc_slot(xprt, task);
- rcu_read_unlock();
}
static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
@@ -1264,11 +1259,9 @@ void xprt_release(struct rpc_task *task)
if (req == NULL) {
if (task->tk_client) {
- rcu_read_lock();
- xprt = rcu_dereference(task->tk_client->cl_xprt);
+ xprt = task->tk_xprt;
if (xprt->snd_task == task)
xprt_release_write(xprt, task);
- rcu_read_unlock();
}
return;
}
@@ -1307,7 +1300,7 @@ void xprt_release(struct rpc_task *task)
static void xprt_init(struct rpc_xprt *xprt, struct net *net)
{
- atomic_set(&xprt->count, 1);
+ kref_init(&xprt->kref);
spin_lock_init(&xprt->transport_lock);
spin_lock_init(&xprt->reserve_lock);
@@ -1318,6 +1311,7 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net)
spin_lock_init(&xprt->bc_pa_lock);
INIT_LIST_HEAD(&xprt->bc_pa_list);
#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+ INIT_LIST_HEAD(&xprt->xprt_switch);
xprt->last_used = jiffies;
xprt->cwnd = RPC_INITCWND;
@@ -1415,6 +1409,24 @@ static void xprt_destroy(struct rpc_xprt *xprt)
xprt->ops->destroy(xprt);
}
+static void xprt_destroy_kref(struct kref *kref)
+{
+ xprt_destroy(container_of(kref, struct rpc_xprt, kref));
+}
+
+/**
+ * xprt_get - return a reference to an RPC transport.
+ * @xprt: pointer to the transport
+ *
+ */
+struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
+{
+ if (xprt != NULL && kref_get_unless_zero(&xprt->kref))
+ return xprt;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(xprt_get);
+
/**
* xprt_put - release a reference to an RPC transport.
* @xprt: pointer to the transport
@@ -1422,7 +1434,7 @@ static void xprt_destroy(struct rpc_xprt *xprt)
*/
void xprt_put(struct rpc_xprt *xprt)
{
- if (atomic_dec_and_test(&xprt->count))
- xprt_destroy(xprt);
+ if (xprt != NULL)
+ kref_put(&xprt->kref, xprt_destroy_kref);
}
EXPORT_SYMBOL_GPL(xprt_put);
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
new file mode 100644
index 000000000000..e7fd76975d86
--- /dev/null
+++ b/net/sunrpc/xprtmultipath.c
@@ -0,0 +1,475 @@
+/*
+ * Multipath support for RPC
+ *
+ * Copyright (c) 2015, 2016, Primary Data, Inc. All rights reserved.
+ *
+ * Trond Myklebust <trond.myklebust@primarydata.com>
+ *
+ */
+#include <linux/types.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include <asm/cmpxchg.h>
+#include <linux/spinlock.h>
+#include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/xprtmultipath.h>
+
+typedef struct rpc_xprt *(*xprt_switch_find_xprt_t)(struct list_head *head,
+ const struct rpc_xprt *cur);
+
+static const struct rpc_xprt_iter_ops rpc_xprt_iter_singular;
+static const struct rpc_xprt_iter_ops rpc_xprt_iter_roundrobin;
+static const struct rpc_xprt_iter_ops rpc_xprt_iter_listall;
+
+static void xprt_switch_add_xprt_locked(struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt)
+{
+ if (unlikely(xprt_get(xprt) == NULL))
+ return;
+ list_add_tail_rcu(&xprt->xprt_switch, &xps->xps_xprt_list);
+ smp_wmb();
+ if (xps->xps_nxprts == 0)
+ xps->xps_net = xprt->xprt_net;
+ xps->xps_nxprts++;
+}
+
+/**
+ * rpc_xprt_switch_add_xprt - Add a new rpc_xprt to an rpc_xprt_switch
+ * @xps: pointer to struct rpc_xprt_switch
+ * @xprt: pointer to struct rpc_xprt
+ *
+ * Adds xprt to the end of the list of struct rpc_xprt in xps.
+ */
+void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt)
+{
+ if (xprt == NULL)
+ return;
+ spin_lock(&xps->xps_lock);
+ if (xps->xps_net == xprt->xprt_net || xps->xps_net == NULL)
+ xprt_switch_add_xprt_locked(xps, xprt);
+ spin_unlock(&xps->xps_lock);
+}
+
+static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt)
+{
+ if (unlikely(xprt == NULL))
+ return;
+ xps->xps_nxprts--;
+ if (xps->xps_nxprts == 0)
+ xps->xps_net = NULL;
+ smp_wmb();
+ list_del_rcu(&xprt->xprt_switch);
+}
+
+/**
+ * rpc_xprt_switch_remove_xprt - Removes an rpc_xprt from a rpc_xprt_switch
+ * @xps: pointer to struct rpc_xprt_switch
+ * @xprt: pointer to struct rpc_xprt
+ *
+ * Removes xprt from the list of struct rpc_xprt in xps.
+ */
+void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt)
+{
+ spin_lock(&xps->xps_lock);
+ xprt_switch_remove_xprt_locked(xps, xprt);
+ spin_unlock(&xps->xps_lock);
+ xprt_put(xprt);
+}
+
+/**
+ * xprt_switch_alloc - Allocate a new struct rpc_xprt_switch
+ * @xprt: pointer to struct rpc_xprt
+ * @gfp_flags: allocation flags
+ *
+ * On success, returns an initialised struct rpc_xprt_switch, containing
+ * the entry xprt. Returns NULL on failure.
+ */
+struct rpc_xprt_switch *xprt_switch_alloc(struct rpc_xprt *xprt,
+ gfp_t gfp_flags)
+{
+ struct rpc_xprt_switch *xps;
+
+ xps = kmalloc(sizeof(*xps), gfp_flags);
+ if (xps != NULL) {
+ spin_lock_init(&xps->xps_lock);
+ kref_init(&xps->xps_kref);
+ xps->xps_nxprts = 0;
+ INIT_LIST_HEAD(&xps->xps_xprt_list);
+ xps->xps_iter_ops = &rpc_xprt_iter_singular;
+ xprt_switch_add_xprt_locked(xps, xprt);
+ }
+
+ return xps;
+}
+
+static void xprt_switch_free_entries(struct rpc_xprt_switch *xps)
+{
+ spin_lock(&xps->xps_lock);
+ while (!list_empty(&xps->xps_xprt_list)) {
+ struct rpc_xprt *xprt;
+
+ xprt = list_first_entry(&xps->xps_xprt_list,
+ struct rpc_xprt, xprt_switch);
+ xprt_switch_remove_xprt_locked(xps, xprt);
+ spin_unlock(&xps->xps_lock);
+ xprt_put(xprt);
+ spin_lock(&xps->xps_lock);
+ }
+ spin_unlock(&xps->xps_lock);
+}
+
+static void xprt_switch_free(struct kref *kref)
+{
+ struct rpc_xprt_switch *xps = container_of(kref,
+ struct rpc_xprt_switch, xps_kref);
+
+ xprt_switch_free_entries(xps);
+ kfree_rcu(xps, xps_rcu);
+}
+
+/**
+ * xprt_switch_get - Return a reference to a rpc_xprt_switch
+ * @xps: pointer to struct rpc_xprt_switch
+ *
+ * Returns a reference to xps unless the refcount is already zero.
+ */
+struct rpc_xprt_switch *xprt_switch_get(struct rpc_xprt_switch *xps)
+{
+ if (xps != NULL && kref_get_unless_zero(&xps->xps_kref))
+ return xps;
+ return NULL;
+}
+
+/**
+ * xprt_switch_put - Release a reference to a rpc_xprt_switch
+ * @xps: pointer to struct rpc_xprt_switch
+ *
+ * Release the reference to xps, and free it once the refcount is zero.
+ */
+void xprt_switch_put(struct rpc_xprt_switch *xps)
+{
+ if (xps != NULL)
+ kref_put(&xps->xps_kref, xprt_switch_free);
+}
+
+/**
+ * rpc_xprt_switch_set_roundrobin - Set a round-robin policy on rpc_xprt_switch
+ * @xps: pointer to struct rpc_xprt_switch
+ *
+ * Sets a round-robin default policy for iterators acting on xps.
+ */
+void rpc_xprt_switch_set_roundrobin(struct rpc_xprt_switch *xps)
+{
+ if (READ_ONCE(xps->xps_iter_ops) != &rpc_xprt_iter_roundrobin)
+ WRITE_ONCE(xps->xps_iter_ops, &rpc_xprt_iter_roundrobin);
+}
+
+static
+const struct rpc_xprt_iter_ops *xprt_iter_ops(const struct rpc_xprt_iter *xpi)
+{
+ if (xpi->xpi_ops != NULL)
+ return xpi->xpi_ops;
+ return rcu_dereference(xpi->xpi_xpswitch)->xps_iter_ops;
+}
+
+static
+void xprt_iter_no_rewind(struct rpc_xprt_iter *xpi)
+{
+}
+
+static
+void xprt_iter_default_rewind(struct rpc_xprt_iter *xpi)
+{
+ WRITE_ONCE(xpi->xpi_cursor, NULL);
+}
+
+static
+struct rpc_xprt *xprt_switch_find_first_entry(struct list_head *head)
+{
+ return list_first_or_null_rcu(head, struct rpc_xprt, xprt_switch);
+}
+
+static
+struct rpc_xprt *xprt_iter_first_entry(struct rpc_xprt_iter *xpi)
+{
+ struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch);
+
+ if (xps == NULL)
+ return NULL;
+ return xprt_switch_find_first_entry(&xps->xps_xprt_list);
+}
+
+static
+struct rpc_xprt *xprt_switch_find_current_entry(struct list_head *head,
+ const struct rpc_xprt *cur)
+{
+ struct rpc_xprt *pos;
+
+ list_for_each_entry_rcu(pos, head, xprt_switch) {
+ if (cur == pos)
+ return pos;
+ }
+ return NULL;
+}
+
+static
+struct rpc_xprt *xprt_iter_current_entry(struct rpc_xprt_iter *xpi)
+{
+ struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch);
+ struct list_head *head;
+
+ if (xps == NULL)
+ return NULL;
+ head = &xps->xps_xprt_list;
+ if (xpi->xpi_cursor == NULL || xps->xps_nxprts < 2)
+ return xprt_switch_find_first_entry(head);
+ return xprt_switch_find_current_entry(head, xpi->xpi_cursor);
+}
+
+static
+struct rpc_xprt *xprt_switch_find_next_entry(struct list_head *head,
+ const struct rpc_xprt *cur)
+{
+ struct rpc_xprt *pos, *prev = NULL;
+
+ list_for_each_entry_rcu(pos, head, xprt_switch) {
+ if (cur == prev)
+ return pos;
+ prev = pos;
+ }
+ return NULL;
+}
+
+static
+struct rpc_xprt *xprt_switch_set_next_cursor(struct list_head *head,
+ struct rpc_xprt **cursor,
+ xprt_switch_find_xprt_t find_next)
+{
+ struct rpc_xprt *cur, *pos, *old;
+
+ cur = READ_ONCE(*cursor);
+ for (;;) {
+ old = cur;
+ pos = find_next(head, old);
+ if (pos == NULL)
+ break;
+ cur = cmpxchg_relaxed(cursor, old, pos);
+ if (cur == old)
+ break;
+ }
+ return pos;
+}
+
+static
+struct rpc_xprt *xprt_iter_next_entry_multiple(struct rpc_xprt_iter *xpi,
+ xprt_switch_find_xprt_t find_next)
+{
+ struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch);
+ struct list_head *head;
+
+ if (xps == NULL)
+ return NULL;
+ head = &xps->xps_xprt_list;
+ if (xps->xps_nxprts < 2)
+ return xprt_switch_find_first_entry(head);
+ return xprt_switch_set_next_cursor(head, &xpi->xpi_cursor, find_next);
+}
+
+static
+struct rpc_xprt *xprt_switch_find_next_entry_roundrobin(struct list_head *head,
+ const struct rpc_xprt *cur)
+{
+ struct rpc_xprt *ret;
+
+ ret = xprt_switch_find_next_entry(head, cur);
+ if (ret != NULL)
+ return ret;
+ return xprt_switch_find_first_entry(head);
+}
+
+static
+struct rpc_xprt *xprt_iter_next_entry_roundrobin(struct rpc_xprt_iter *xpi)
+{
+ return xprt_iter_next_entry_multiple(xpi,
+ xprt_switch_find_next_entry_roundrobin);
+}
+
+static
+struct rpc_xprt *xprt_iter_next_entry_all(struct rpc_xprt_iter *xpi)
+{
+ return xprt_iter_next_entry_multiple(xpi, xprt_switch_find_next_entry);
+}
+
+/*
+ * xprt_iter_rewind - Resets the xprt iterator
+ * @xpi: pointer to rpc_xprt_iter
+ *
+ * Resets xpi to ensure that it points to the first entry in the list
+ * of transports.
+ */
+static
+void xprt_iter_rewind(struct rpc_xprt_iter *xpi)
+{
+ rcu_read_lock();
+ xprt_iter_ops(xpi)->xpi_rewind(xpi);
+ rcu_read_unlock();
+}
+
+static void __xprt_iter_init(struct rpc_xprt_iter *xpi,
+ struct rpc_xprt_switch *xps,
+ const struct rpc_xprt_iter_ops *ops)
+{
+ rcu_assign_pointer(xpi->xpi_xpswitch, xprt_switch_get(xps));
+ xpi->xpi_cursor = NULL;
+ xpi->xpi_ops = ops;
+}
+
+/**
+ * xprt_iter_init - Initialise an xprt iterator
+ * @xpi: pointer to rpc_xprt_iter
+ * @xps: pointer to rpc_xprt_switch
+ *
+ * Initialises the iterator to use the default iterator ops
+ * as set in xps. This function is mainly intended for internal
+ * use in the rpc_client.
+ */
+void xprt_iter_init(struct rpc_xprt_iter *xpi,
+ struct rpc_xprt_switch *xps)
+{
+ __xprt_iter_init(xpi, xps, NULL);
+}
+
+/**
+ * xprt_iter_init_listall - Initialise an xprt iterator
+ * @xpi: pointer to rpc_xprt_iter
+ * @xps: pointer to rpc_xprt_switch
+ *
+ * Initialises the iterator to iterate once through the entire list
+ * of entries in xps.
+ */
+void xprt_iter_init_listall(struct rpc_xprt_iter *xpi,
+ struct rpc_xprt_switch *xps)
+{
+ __xprt_iter_init(xpi, xps, &rpc_xprt_iter_listall);
+}
+
+/**
+ * xprt_iter_xchg_switch - Atomically swap out the rpc_xprt_switch
+ * @xpi: pointer to rpc_xprt_iter
+ * @xps: pointer to a new rpc_xprt_switch or NULL
+ *
+ * Swaps out the existing xpi->xpi_xpswitch with a new value.
+ */
+struct rpc_xprt_switch *xprt_iter_xchg_switch(struct rpc_xprt_iter *xpi,
+ struct rpc_xprt_switch *newswitch)
+{
+ struct rpc_xprt_switch __rcu *oldswitch;
+
+ /* Atomically swap out the old xpswitch */
+ oldswitch = xchg(&xpi->xpi_xpswitch, RCU_INITIALIZER(newswitch));
+ if (newswitch != NULL)
+ xprt_iter_rewind(xpi);
+ return rcu_dereference_protected(oldswitch, true);
+}
+
+/**
+ * xprt_iter_destroy - Destroys the xprt iterator
+ * @xpi pointer to rpc_xprt_iter
+ */
+void xprt_iter_destroy(struct rpc_xprt_iter *xpi)
+{
+ xprt_switch_put(xprt_iter_xchg_switch(xpi, NULL));
+}
+
+/**
+ * xprt_iter_xprt - Returns the rpc_xprt pointed to by the cursor
+ * @xpi: pointer to rpc_xprt_iter
+ *
+ * Returns a pointer to the struct rpc_xprt that is currently
+ * pointed to by the cursor.
+ * Caller must be holding rcu_read_lock().
+ */
+struct rpc_xprt *xprt_iter_xprt(struct rpc_xprt_iter *xpi)
+{
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ return xprt_iter_ops(xpi)->xpi_xprt(xpi);
+}
+
+static
+struct rpc_xprt *xprt_iter_get_helper(struct rpc_xprt_iter *xpi,
+ struct rpc_xprt *(*fn)(struct rpc_xprt_iter *))
+{
+ struct rpc_xprt *ret;
+
+ do {
+ ret = fn(xpi);
+ if (ret == NULL)
+ break;
+ ret = xprt_get(ret);
+ } while (ret == NULL);
+ return ret;
+}
+
+/**
+ * xprt_iter_get_xprt - Returns the rpc_xprt pointed to by the cursor
+ * @xpi: pointer to rpc_xprt_iter
+ *
+ * Returns a reference to the struct rpc_xprt that is currently
+ * pointed to by the cursor.
+ */
+struct rpc_xprt *xprt_iter_get_xprt(struct rpc_xprt_iter *xpi)
+{
+ struct rpc_xprt *xprt;
+
+ rcu_read_lock();
+ xprt = xprt_iter_get_helper(xpi, xprt_iter_ops(xpi)->xpi_xprt);
+ rcu_read_unlock();
+ return xprt;
+}
+
+/**
+ * xprt_iter_get_next - Returns the next rpc_xprt following the cursor
+ * @xpi: pointer to rpc_xprt_iter
+ *
+ * Returns a reference to the struct rpc_xprt that immediately follows the
+ * entry pointed to by the cursor.
+ */
+struct rpc_xprt *xprt_iter_get_next(struct rpc_xprt_iter *xpi)
+{
+ struct rpc_xprt *xprt;
+
+ rcu_read_lock();
+ xprt = xprt_iter_get_helper(xpi, xprt_iter_ops(xpi)->xpi_next);
+ rcu_read_unlock();
+ return xprt;
+}
+
+/* Policy for always returning the first entry in the rpc_xprt_switch */
+static
+const struct rpc_xprt_iter_ops rpc_xprt_iter_singular = {
+ .xpi_rewind = xprt_iter_no_rewind,
+ .xpi_xprt = xprt_iter_first_entry,
+ .xpi_next = xprt_iter_first_entry,
+};
+
+/* Policy for round-robin iteration of entries in the rpc_xprt_switch */
+static
+const struct rpc_xprt_iter_ops rpc_xprt_iter_roundrobin = {
+ .xpi_rewind = xprt_iter_default_rewind,
+ .xpi_xprt = xprt_iter_current_entry,
+ .xpi_next = xprt_iter_next_entry_roundrobin,
+};
+
+/* Policy for once-through iteration of entries in the rpc_xprt_switch */
+static
+const struct rpc_xprt_iter_ops rpc_xprt_iter_listall = {
+ .xpi_rewind = xprt_iter_default_rewind,
+ .xpi_xprt = xprt_iter_current_entry,
+ .xpi_next = xprt_iter_next_entry_all,
+};
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index fde2138b81e7..65e759569e48 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1844,9 +1844,7 @@ static int xs_bind(struct sock_xprt *transport, struct socket *sock)
*/
static void xs_local_rpcbind(struct rpc_task *task)
{
- rcu_read_lock();
- xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
- rcu_read_unlock();
+ xprt_set_bound(task->tk_xprt);
}
static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-23 09:02:27 +0200